1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of version 2 of the GNU General Public
6 * License as published by the Free Software Foundation.
8 #ifndef _UAPI__LINUX_BPF_H__
9 #define _UAPI__LINUX_BPF_H__
11 #include <linux/types.h>
12 #include <linux/bpf_common.h>
14 /* Extended instruction set based on top of classic BPF */
16 /* instruction classes */
17 #define BPF_JMP32 0x06 /* jmp mode in word width */
18 #define BPF_ALU64 0x07 /* alu mode in double word width */
21 #define BPF_DW 0x18 /* double word (64-bit) */
22 #define BPF_ATOMIC 0xc0 /* atomic memory ops - op type in immediate */
23 #define BPF_XADD 0xc0 /* exclusive add - legacy name */
26 #define BPF_MOV 0xb0 /* mov reg to reg */
27 #define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */
29 /* change endianness of a register */
30 #define BPF_END 0xd0 /* flags for endianness conversion: */
31 #define BPF_TO_LE 0x00 /* convert to little-endian */
32 #define BPF_TO_BE 0x08 /* convert to big-endian */
33 #define BPF_FROM_LE BPF_TO_LE
34 #define BPF_FROM_BE BPF_TO_BE
37 #define BPF_JNE 0x50 /* jump != */
38 #define BPF_JLT 0xa0 /* LT is unsigned, '<' */
39 #define BPF_JLE 0xb0 /* LE is unsigned, '<=' */
40 #define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */
41 #define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */
42 #define BPF_JSLT 0xc0 /* SLT is signed, '<' */
43 #define BPF_JSLE 0xd0 /* SLE is signed, '<=' */
44 #define BPF_CALL 0x80 /* function call */
45 #define BPF_EXIT 0x90 /* function return */
47 /* atomic op type fields (stored in immediate) */
48 #define BPF_FETCH 0x01 /* not an opcode on its own, used to build others */
49 #define BPF_XCHG (0xe0 | BPF_FETCH) /* atomic exchange */
50 #define BPF_CMPXCHG (0xf0 | BPF_FETCH) /* atomic compare-and-write */
52 /* Register numbers */
68 /* BPF has 10 general purpose 64-bit registers and stack frame. */
69 #define MAX_BPF_REG __MAX_BPF_REG
72 __u8 code; /* opcode */
73 __u8 dst_reg:4; /* dest register */
74 __u8 src_reg:4; /* source register */
75 __s16 off; /* signed offset */
76 __s32 imm; /* signed immediate constant */
79 /* Key of an a BPF_MAP_TYPE_LPM_TRIE entry */
80 struct bpf_lpm_trie_key {
81 __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */
82 __u8 data[0]; /* Arbitrary size */
85 struct bpf_cgroup_storage_key {
86 __u64 cgroup_inode_id; /* cgroup inode id */
87 __u32 attach_type; /* program attach type (enum bpf_attach_type) */
90 union bpf_iter_link_info {
96 /* BPF syscall commands, see bpf(2) man-page for more details. */
98 * DOC: eBPF Syscall Preamble
100 * The operation to be performed by the **bpf**\ () system call is determined
101 * by the *cmd* argument. Each operation takes an accompanying argument,
102 * provided via *attr*, which is a pointer to a union of type *bpf_attr* (see
103 * below). The size argument is the size of the union pointed to by *attr*.
106 * DOC: eBPF Syscall Commands
110 * Create a map and return a file descriptor that refers to the
111 * map. The close-on-exec file descriptor flag (see **fcntl**\ (2))
112 * is automatically enabled for the new file descriptor.
114 * Applying **close**\ (2) to the file descriptor returned by
115 * **BPF_MAP_CREATE** will delete the map (but see NOTES).
118 * A new file descriptor (a nonnegative integer), or -1 if an
119 * error occurred (in which case, *errno* is set appropriately).
121 * BPF_MAP_LOOKUP_ELEM
123 * Look up an element with a given *key* in the map referred to
124 * by the file descriptor *map_fd*.
126 * The *flags* argument may be specified as one of the
130 * Look up the value of a spin-locked map without
131 * returning the lock. This must be specified if the
132 * elements contain a spinlock.
135 * Returns zero on success. On error, -1 is returned and *errno*
136 * is set appropriately.
138 * BPF_MAP_UPDATE_ELEM
140 * Create or update an element (key/value pair) in a specified map.
142 * The *flags* argument should be specified as one of the
146 * Create a new element or update an existing element.
148 * Create a new element only if it did not exist.
150 * Update an existing element.
152 * Update a spin_lock-ed map element.
155 * Returns zero on success. On error, -1 is returned and *errno*
156 * is set appropriately.
158 * May set *errno* to **EINVAL**, **EPERM**, **ENOMEM**,
159 * **E2BIG**, **EEXIST**, or **ENOENT**.
162 * The number of elements in the map reached the
163 * *max_entries* limit specified at map creation time.
165 * If *flags* specifies **BPF_NOEXIST** and the element
166 * with *key* already exists in the map.
168 * If *flags* specifies **BPF_EXIST** and the element with
169 * *key* does not exist in the map.
171 * BPF_MAP_DELETE_ELEM
173 * Look up and delete an element by key in a specified map.
176 * Returns zero on success. On error, -1 is returned and *errno*
177 * is set appropriately.
179 * BPF_MAP_GET_NEXT_KEY
181 * Look up an element by key in a specified map and return the key
182 * of the next element. Can be used to iterate over all elements
186 * Returns zero on success. On error, -1 is returned and *errno*
187 * is set appropriately.
189 * The following cases can be used to iterate over all elements of
192 * * If *key* is not found, the operation returns zero and sets
193 * the *next_key* pointer to the key of the first element.
194 * * If *key* is found, the operation returns zero and sets the
195 * *next_key* pointer to the key of the next element.
196 * * If *key* is the last element, returns -1 and *errno* is set
199 * May set *errno* to **ENOMEM**, **EFAULT**, **EPERM**, or
200 * **EINVAL** on error.
204 * Verify and load an eBPF program, returning a new file
205 * descriptor associated with the program.
207 * Applying **close**\ (2) to the file descriptor returned by
208 * **BPF_PROG_LOAD** will unload the eBPF program (but see NOTES).
210 * The close-on-exec file descriptor flag (see **fcntl**\ (2)) is
211 * automatically enabled for the new file descriptor.
214 * A new file descriptor (a nonnegative integer), or -1 if an
215 * error occurred (in which case, *errno* is set appropriately).
219 * Pin an eBPF program or map referred by the specified *bpf_fd*
220 * to the provided *pathname* on the filesystem.
222 * The *pathname* argument must not contain a dot (".").
224 * On success, *pathname* retains a reference to the eBPF object,
225 * preventing deallocation of the object when the original
226 * *bpf_fd* is closed. This allow the eBPF object to live beyond
227 * **close**\ (\ *bpf_fd*\ ), and hence the lifetime of the parent
230 * Applying **unlink**\ (2) or similar calls to the *pathname*
231 * unpins the object from the filesystem, removing the reference.
232 * If no other file descriptors or filesystem nodes refer to the
233 * same object, it will be deallocated (see NOTES).
235 * The filesystem type for the parent directory of *pathname* must
236 * be **BPF_FS_MAGIC**.
239 * Returns zero on success. On error, -1 is returned and *errno*
240 * is set appropriately.
244 * Open a file descriptor for the eBPF object pinned to the
245 * specified *pathname*.
248 * A new file descriptor (a nonnegative integer), or -1 if an
249 * error occurred (in which case, *errno* is set appropriately).
253 * Attach an eBPF program to a *target_fd* at the specified
254 * *attach_type* hook.
256 * The *attach_type* specifies the eBPF attachment point to
257 * attach the program to, and must be one of *bpf_attach_type*
260 * The *attach_bpf_fd* must be a valid file descriptor for a
261 * loaded eBPF program of a cgroup, flow dissector, LIRC, sockmap
262 * or sock_ops type corresponding to the specified *attach_type*.
264 * The *target_fd* must be a valid file descriptor for a kernel
265 * object which depends on the attach type of *attach_bpf_fd*:
267 * **BPF_PROG_TYPE_CGROUP_DEVICE**,
268 * **BPF_PROG_TYPE_CGROUP_SKB**,
269 * **BPF_PROG_TYPE_CGROUP_SOCK**,
270 * **BPF_PROG_TYPE_CGROUP_SOCK_ADDR**,
271 * **BPF_PROG_TYPE_CGROUP_SOCKOPT**,
272 * **BPF_PROG_TYPE_CGROUP_SYSCTL**,
273 * **BPF_PROG_TYPE_SOCK_OPS**
275 * Control Group v2 hierarchy with the eBPF controller
276 * enabled. Requires the kernel to be compiled with
277 * **CONFIG_CGROUP_BPF**.
279 * **BPF_PROG_TYPE_FLOW_DISSECTOR**
281 * Network namespace (eg /proc/self/ns/net).
283 * **BPF_PROG_TYPE_LIRC_MODE2**
285 * LIRC device path (eg /dev/lircN). Requires the kernel
286 * to be compiled with **CONFIG_BPF_LIRC_MODE2**.
288 * **BPF_PROG_TYPE_SK_SKB**,
289 * **BPF_PROG_TYPE_SK_MSG**
291 * eBPF map of socket type (eg **BPF_MAP_TYPE_SOCKHASH**).
294 * Returns zero on success. On error, -1 is returned and *errno*
295 * is set appropriately.
299 * Detach the eBPF program associated with the *target_fd* at the
300 * hook specified by *attach_type*. The program must have been
301 * previously attached using **BPF_PROG_ATTACH**.
304 * Returns zero on success. On error, -1 is returned and *errno*
305 * is set appropriately.
309 * Run the eBPF program associated with the *prog_fd* a *repeat*
310 * number of times against a provided program context *ctx_in* and
311 * data *data_in*, and return the modified program context
312 * *ctx_out*, *data_out* (for example, packet data), result of the
313 * execution *retval*, and *duration* of the test run.
315 * The sizes of the buffers provided as input and output
316 * parameters *ctx_in*, *ctx_out*, *data_in*, and *data_out* must
317 * be provided in the corresponding variables *ctx_size_in*,
318 * *ctx_size_out*, *data_size_in*, and/or *data_size_out*. If any
319 * of these parameters are not provided (ie set to NULL), the
320 * corresponding size field must be zero.
322 * Some program types have particular requirements:
324 * **BPF_PROG_TYPE_SK_LOOKUP**
325 * *data_in* and *data_out* must be NULL.
327 * **BPF_PROG_TYPE_RAW_TRACEPOINT**,
328 * **BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE**
330 * *ctx_out*, *data_in* and *data_out* must be NULL.
331 * *repeat* must be zero.
334 * Returns zero on success. On error, -1 is returned and *errno*
335 * is set appropriately.
338 * Either *data_size_out* or *ctx_size_out* is too small.
340 * This command is not supported by the program type of
341 * the program referred to by *prog_fd*.
343 * BPF_PROG_GET_NEXT_ID
345 * Fetch the next eBPF program currently loaded into the kernel.
347 * Looks for the eBPF program with an id greater than *start_id*
348 * and updates *next_id* on success. If no other eBPF programs
349 * remain with ids higher than *start_id*, returns -1 and sets
350 * *errno* to **ENOENT**.
353 * Returns zero on success. On error, or when no id remains, -1
354 * is returned and *errno* is set appropriately.
356 * BPF_MAP_GET_NEXT_ID
358 * Fetch the next eBPF map currently loaded into the kernel.
360 * Looks for the eBPF map with an id greater than *start_id*
361 * and updates *next_id* on success. If no other eBPF maps
362 * remain with ids higher than *start_id*, returns -1 and sets
363 * *errno* to **ENOENT**.
366 * Returns zero on success. On error, or when no id remains, -1
367 * is returned and *errno* is set appropriately.
369 * BPF_PROG_GET_FD_BY_ID
371 * Open a file descriptor for the eBPF program corresponding to
375 * A new file descriptor (a nonnegative integer), or -1 if an
376 * error occurred (in which case, *errno* is set appropriately).
378 * BPF_MAP_GET_FD_BY_ID
380 * Open a file descriptor for the eBPF map corresponding to
384 * A new file descriptor (a nonnegative integer), or -1 if an
385 * error occurred (in which case, *errno* is set appropriately).
387 * BPF_OBJ_GET_INFO_BY_FD
389 * Obtain information about the eBPF object corresponding to
392 * Populates up to *info_len* bytes of *info*, which will be in
393 * one of the following formats depending on the eBPF object type
396 * * **struct bpf_prog_info**
397 * * **struct bpf_map_info**
398 * * **struct bpf_btf_info**
399 * * **struct bpf_link_info**
402 * Returns zero on success. On error, -1 is returned and *errno*
403 * is set appropriately.
407 * Obtain information about eBPF programs associated with the
408 * specified *attach_type* hook.
410 * The *target_fd* must be a valid file descriptor for a kernel
411 * object which depends on the attach type of *attach_bpf_fd*:
413 * **BPF_PROG_TYPE_CGROUP_DEVICE**,
414 * **BPF_PROG_TYPE_CGROUP_SKB**,
415 * **BPF_PROG_TYPE_CGROUP_SOCK**,
416 * **BPF_PROG_TYPE_CGROUP_SOCK_ADDR**,
417 * **BPF_PROG_TYPE_CGROUP_SOCKOPT**,
418 * **BPF_PROG_TYPE_CGROUP_SYSCTL**,
419 * **BPF_PROG_TYPE_SOCK_OPS**
421 * Control Group v2 hierarchy with the eBPF controller
422 * enabled. Requires the kernel to be compiled with
423 * **CONFIG_CGROUP_BPF**.
425 * **BPF_PROG_TYPE_FLOW_DISSECTOR**
427 * Network namespace (eg /proc/self/ns/net).
429 * **BPF_PROG_TYPE_LIRC_MODE2**
431 * LIRC device path (eg /dev/lircN). Requires the kernel
432 * to be compiled with **CONFIG_BPF_LIRC_MODE2**.
434 * **BPF_PROG_QUERY** always fetches the number of programs
435 * attached and the *attach_flags* which were used to attach those
436 * programs. Additionally, if *prog_ids* is nonzero and the number
437 * of attached programs is less than *prog_cnt*, populates
438 * *prog_ids* with the eBPF program ids of the programs attached
441 * The following flags may alter the result:
443 * **BPF_F_QUERY_EFFECTIVE**
444 * Only return information regarding programs which are
445 * currently effective at the specified *target_fd*.
448 * Returns zero on success. On error, -1 is returned and *errno*
449 * is set appropriately.
451 * BPF_RAW_TRACEPOINT_OPEN
453 * Attach an eBPF program to a tracepoint *name* to access kernel
454 * internal arguments of the tracepoint in their raw form.
456 * The *prog_fd* must be a valid file descriptor associated with
457 * a loaded eBPF program of type **BPF_PROG_TYPE_RAW_TRACEPOINT**.
459 * No ABI guarantees are made about the content of tracepoint
460 * arguments exposed to the corresponding eBPF program.
462 * Applying **close**\ (2) to the file descriptor returned by
463 * **BPF_RAW_TRACEPOINT_OPEN** will delete the map (but see NOTES).
466 * A new file descriptor (a nonnegative integer), or -1 if an
467 * error occurred (in which case, *errno* is set appropriately).
471 * Verify and load BPF Type Format (BTF) metadata into the kernel,
472 * returning a new file descriptor associated with the metadata.
473 * BTF is described in more detail at
474 * https://www.kernel.org/doc/html/latest/bpf/btf.html.
476 * The *btf* parameter must point to valid memory providing
477 * *btf_size* bytes of BTF binary metadata.
479 * The returned file descriptor can be passed to other **bpf**\ ()
480 * subcommands such as **BPF_PROG_LOAD** or **BPF_MAP_CREATE** to
481 * associate the BTF with those objects.
483 * Similar to **BPF_PROG_LOAD**, **BPF_BTF_LOAD** has optional
484 * parameters to specify a *btf_log_buf*, *btf_log_size* and
485 * *btf_log_level* which allow the kernel to return freeform log
486 * output regarding the BTF verification process.
489 * A new file descriptor (a nonnegative integer), or -1 if an
490 * error occurred (in which case, *errno* is set appropriately).
492 * BPF_BTF_GET_FD_BY_ID
494 * Open a file descriptor for the BPF Type Format (BTF)
495 * corresponding to *btf_id*.
498 * A new file descriptor (a nonnegative integer), or -1 if an
499 * error occurred (in which case, *errno* is set appropriately).
503 * Obtain information about eBPF programs associated with the
504 * target process identified by *pid* and *fd*.
506 * If the *pid* and *fd* are associated with a tracepoint, kprobe
507 * or uprobe perf event, then the *prog_id* and *fd_type* will
508 * be populated with the eBPF program id and file descriptor type
509 * of type **bpf_task_fd_type**. If associated with a kprobe or
510 * uprobe, the *probe_offset* and *probe_addr* will also be
511 * populated. Optionally, if *buf* is provided, then up to
512 * *buf_len* bytes of *buf* will be populated with the name of
513 * the tracepoint, kprobe or uprobe.
515 * The resulting *prog_id* may be introspected in deeper detail
516 * using **BPF_PROG_GET_FD_BY_ID** and **BPF_OBJ_GET_INFO_BY_FD**.
519 * Returns zero on success. On error, -1 is returned and *errno*
520 * is set appropriately.
522 * BPF_MAP_LOOKUP_AND_DELETE_ELEM
524 * Look up an element with the given *key* in the map referred to
525 * by the file descriptor *fd*, and if found, delete the element.
527 * For **BPF_MAP_TYPE_QUEUE** and **BPF_MAP_TYPE_STACK** map
528 * types, the *flags* argument needs to be set to 0, but for other
529 * map types, it may be specified as:
532 * Look up and delete the value of a spin-locked map
533 * without returning the lock. This must be specified if
534 * the elements contain a spinlock.
536 * The **BPF_MAP_TYPE_QUEUE** and **BPF_MAP_TYPE_STACK** map types
537 * implement this command as a "pop" operation, deleting the top
538 * element rather than one corresponding to *key*.
539 * The *key* and *key_len* parameters should be zeroed when
540 * issuing this operation for these map types.
542 * This command is only valid for the following map types:
543 * * **BPF_MAP_TYPE_QUEUE**
544 * * **BPF_MAP_TYPE_STACK**
545 * * **BPF_MAP_TYPE_HASH**
546 * * **BPF_MAP_TYPE_PERCPU_HASH**
547 * * **BPF_MAP_TYPE_LRU_HASH**
548 * * **BPF_MAP_TYPE_LRU_PERCPU_HASH**
551 * Returns zero on success. On error, -1 is returned and *errno*
552 * is set appropriately.
556 * Freeze the permissions of the specified map.
558 * Write permissions may be frozen by passing zero *flags*.
559 * Upon success, no future syscall invocations may alter the
560 * map state of *map_fd*. Write operations from eBPF programs
561 * are still possible for a frozen map.
563 * Not supported for maps of type **BPF_MAP_TYPE_STRUCT_OPS**.
566 * Returns zero on success. On error, -1 is returned and *errno*
567 * is set appropriately.
569 * BPF_BTF_GET_NEXT_ID
571 * Fetch the next BPF Type Format (BTF) object currently loaded
574 * Looks for the BTF object with an id greater than *start_id*
575 * and updates *next_id* on success. If no other BTF objects
576 * remain with ids higher than *start_id*, returns -1 and sets
577 * *errno* to **ENOENT**.
580 * Returns zero on success. On error, or when no id remains, -1
581 * is returned and *errno* is set appropriately.
583 * BPF_MAP_LOOKUP_BATCH
585 * Iterate and fetch multiple elements in a map.
587 * Two opaque values are used to manage batch operations,
588 * *in_batch* and *out_batch*. Initially, *in_batch* must be set
589 * to NULL to begin the batched operation. After each subsequent
590 * **BPF_MAP_LOOKUP_BATCH**, the caller should pass the resultant
591 * *out_batch* as the *in_batch* for the next operation to
592 * continue iteration from the current point.
594 * The *keys* and *values* are output parameters which must point
595 * to memory large enough to hold *count* items based on the key
596 * and value size of the map *map_fd*. The *keys* buffer must be
597 * of *key_size* * *count*. The *values* buffer must be of
598 * *value_size* * *count*.
600 * The *elem_flags* argument may be specified as one of the
604 * Look up the value of a spin-locked map without
605 * returning the lock. This must be specified if the
606 * elements contain a spinlock.
608 * On success, *count* elements from the map are copied into the
609 * user buffer, with the keys copied into *keys* and the values
610 * copied into the corresponding indices in *values*.
612 * If an error is returned and *errno* is not **EFAULT**, *count*
613 * is set to the number of successfully processed elements.
616 * Returns zero on success. On error, -1 is returned and *errno*
617 * is set appropriately.
619 * May set *errno* to **ENOSPC** to indicate that *keys* or
620 * *values* is too small to dump an entire bucket during
621 * iteration of a hash-based map type.
623 * BPF_MAP_LOOKUP_AND_DELETE_BATCH
625 * Iterate and delete all elements in a map.
627 * This operation has the same behavior as
628 * **BPF_MAP_LOOKUP_BATCH** with two exceptions:
630 * * Every element that is successfully returned is also deleted
631 * from the map. This is at least *count* elements. Note that
632 * *count* is both an input and an output parameter.
633 * * Upon returning with *errno* set to **EFAULT**, up to
634 * *count* elements may be deleted without returning the keys
635 * and values of the deleted elements.
638 * Returns zero on success. On error, -1 is returned and *errno*
639 * is set appropriately.
641 * BPF_MAP_UPDATE_BATCH
643 * Update multiple elements in a map by *key*.
645 * The *keys* and *values* are input parameters which must point
646 * to memory large enough to hold *count* items based on the key
647 * and value size of the map *map_fd*. The *keys* buffer must be
648 * of *key_size* * *count*. The *values* buffer must be of
649 * *value_size* * *count*.
651 * Each element specified in *keys* is sequentially updated to the
652 * value in the corresponding index in *values*. The *in_batch*
653 * and *out_batch* parameters are ignored and should be zeroed.
655 * The *elem_flags* argument should be specified as one of the
659 * Create new elements or update a existing elements.
661 * Create new elements only if they do not exist.
663 * Update existing elements.
665 * Update spin_lock-ed map elements. This must be
666 * specified if the map value contains a spinlock.
668 * On success, *count* elements from the map are updated.
670 * If an error is returned and *errno* is not **EFAULT**, *count*
671 * is set to the number of successfully processed elements.
674 * Returns zero on success. On error, -1 is returned and *errno*
675 * is set appropriately.
677 * May set *errno* to **EINVAL**, **EPERM**, **ENOMEM**, or
678 * **E2BIG**. **E2BIG** indicates that the number of elements in
679 * the map reached the *max_entries* limit specified at map
682 * May set *errno* to one of the following error codes under
683 * specific circumstances:
686 * If *flags* specifies **BPF_NOEXIST** and the element
687 * with *key* already exists in the map.
689 * If *flags* specifies **BPF_EXIST** and the element with
690 * *key* does not exist in the map.
692 * BPF_MAP_DELETE_BATCH
694 * Delete multiple elements in a map by *key*.
696 * The *keys* parameter is an input parameter which must point
697 * to memory large enough to hold *count* items based on the key
698 * size of the map *map_fd*, that is, *key_size* * *count*.
700 * Each element specified in *keys* is sequentially deleted. The
701 * *in_batch*, *out_batch*, and *values* parameters are ignored
702 * and should be zeroed.
704 * The *elem_flags* argument may be specified as one of the
708 * Look up the value of a spin-locked map without
709 * returning the lock. This must be specified if the
710 * elements contain a spinlock.
712 * On success, *count* elements from the map are updated.
714 * If an error is returned and *errno* is not **EFAULT**, *count*
715 * is set to the number of successfully processed elements. If
716 * *errno* is **EFAULT**, up to *count* elements may be been
720 * Returns zero on success. On error, -1 is returned and *errno*
721 * is set appropriately.
725 * Attach an eBPF program to a *target_fd* at the specified
726 * *attach_type* hook and return a file descriptor handle for
730 * A new file descriptor (a nonnegative integer), or -1 if an
731 * error occurred (in which case, *errno* is set appropriately).
735 * Update the eBPF program in the specified *link_fd* to
739 * Returns zero on success. On error, -1 is returned and *errno*
740 * is set appropriately.
742 * BPF_LINK_GET_FD_BY_ID
744 * Open a file descriptor for the eBPF Link corresponding to
748 * A new file descriptor (a nonnegative integer), or -1 if an
749 * error occurred (in which case, *errno* is set appropriately).
751 * BPF_LINK_GET_NEXT_ID
753 * Fetch the next eBPF link currently loaded into the kernel.
755 * Looks for the eBPF link with an id greater than *start_id*
756 * and updates *next_id* on success. If no other eBPF links
757 * remain with ids higher than *start_id*, returns -1 and sets
758 * *errno* to **ENOENT**.
761 * Returns zero on success. On error, or when no id remains, -1
762 * is returned and *errno* is set appropriately.
766 * Enable eBPF runtime statistics gathering.
768 * Runtime statistics gathering for the eBPF runtime is disabled
769 * by default to minimize the corresponding performance overhead.
770 * This command enables statistics globally.
772 * Multiple programs may independently enable statistics.
773 * After gathering the desired statistics, eBPF runtime statistics
774 * may be disabled again by calling **close**\ (2) for the file
775 * descriptor returned by this function. Statistics will only be
776 * disabled system-wide when all outstanding file descriptors
777 * returned by prior calls for this subcommand are closed.
780 * A new file descriptor (a nonnegative integer), or -1 if an
781 * error occurred (in which case, *errno* is set appropriately).
785 * Create an iterator on top of the specified *link_fd* (as
786 * previously created using **BPF_LINK_CREATE**) and return a
787 * file descriptor that can be used to trigger the iteration.
789 * If the resulting file descriptor is pinned to the filesystem
790 * using **BPF_OBJ_PIN**, then subsequent **read**\ (2) syscalls
791 * for that path will trigger the iterator to read kernel state
792 * using the eBPF program attached to *link_fd*.
795 * A new file descriptor (a nonnegative integer), or -1 if an
796 * error occurred (in which case, *errno* is set appropriately).
800 * Forcefully detach the specified *link_fd* from its
801 * corresponding attachment point.
804 * Returns zero on success. On error, -1 is returned and *errno*
805 * is set appropriately.
809 * Bind a map to the lifetime of an eBPF program.
811 * The map identified by *map_fd* is bound to the program
812 * identified by *prog_fd* and only released when *prog_fd* is
813 * released. This may be used in cases where metadata should be
814 * associated with a program which otherwise does not contain any
815 * references to the map (for example, embedded in the eBPF
816 * program instructions).
819 * Returns zero on success. On error, -1 is returned and *errno*
820 * is set appropriately.
823 * eBPF objects (maps and programs) can be shared between processes.
825 * * After **fork**\ (2), the child inherits file descriptors
826 * referring to the same eBPF objects.
827 * * File descriptors referring to eBPF objects can be transferred over
828 * **unix**\ (7) domain sockets.
829 * * File descriptors referring to eBPF objects can be duplicated in the
830 * usual way, using **dup**\ (2) and similar calls.
831 * * File descriptors referring to eBPF objects can be pinned to the
832 * filesystem using the **BPF_OBJ_PIN** command of **bpf**\ (2).
834 * An eBPF object is deallocated only after all file descriptors referring
835 * to the object have been closed and no references remain pinned to the
836 * filesystem or attached (for example, bound to a program or device).
843 BPF_MAP_GET_NEXT_KEY,
850 BPF_PROG_RUN = BPF_PROG_TEST_RUN,
851 BPF_PROG_GET_NEXT_ID,
853 BPF_PROG_GET_FD_BY_ID,
854 BPF_MAP_GET_FD_BY_ID,
855 BPF_OBJ_GET_INFO_BY_FD,
857 BPF_RAW_TRACEPOINT_OPEN,
859 BPF_BTF_GET_FD_BY_ID,
861 BPF_MAP_LOOKUP_AND_DELETE_ELEM,
864 BPF_MAP_LOOKUP_BATCH,
865 BPF_MAP_LOOKUP_AND_DELETE_BATCH,
866 BPF_MAP_UPDATE_BATCH,
867 BPF_MAP_DELETE_BATCH,
870 BPF_LINK_GET_FD_BY_ID,
871 BPF_LINK_GET_NEXT_ID,
882 BPF_MAP_TYPE_PROG_ARRAY,
883 BPF_MAP_TYPE_PERF_EVENT_ARRAY,
884 BPF_MAP_TYPE_PERCPU_HASH,
885 BPF_MAP_TYPE_PERCPU_ARRAY,
886 BPF_MAP_TYPE_STACK_TRACE,
887 BPF_MAP_TYPE_CGROUP_ARRAY,
888 BPF_MAP_TYPE_LRU_HASH,
889 BPF_MAP_TYPE_LRU_PERCPU_HASH,
890 BPF_MAP_TYPE_LPM_TRIE,
891 BPF_MAP_TYPE_ARRAY_OF_MAPS,
892 BPF_MAP_TYPE_HASH_OF_MAPS,
894 BPF_MAP_TYPE_SOCKMAP,
897 BPF_MAP_TYPE_SOCKHASH,
898 BPF_MAP_TYPE_CGROUP_STORAGE,
899 BPF_MAP_TYPE_REUSEPORT_SOCKARRAY,
900 BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE,
903 BPF_MAP_TYPE_SK_STORAGE,
904 BPF_MAP_TYPE_DEVMAP_HASH,
905 BPF_MAP_TYPE_STRUCT_OPS,
906 BPF_MAP_TYPE_RINGBUF,
907 BPF_MAP_TYPE_INODE_STORAGE,
908 BPF_MAP_TYPE_TASK_STORAGE,
911 /* Note that tracing related programs such as
912 * BPF_PROG_TYPE_{KPROBE,TRACEPOINT,PERF_EVENT,RAW_TRACEPOINT}
913 * are not subject to a stable API since kernel internal data
914 * structures can change from release to release and may
915 * therefore break existing tracing BPF programs. Tracing BPF
916 * programs correspond to /a/ specific kernel which is to be
917 * analyzed, and not /a/ specific kernel /and/ all future ones.
920 BPF_PROG_TYPE_UNSPEC,
921 BPF_PROG_TYPE_SOCKET_FILTER,
922 BPF_PROG_TYPE_KPROBE,
923 BPF_PROG_TYPE_SCHED_CLS,
924 BPF_PROG_TYPE_SCHED_ACT,
925 BPF_PROG_TYPE_TRACEPOINT,
927 BPF_PROG_TYPE_PERF_EVENT,
928 BPF_PROG_TYPE_CGROUP_SKB,
929 BPF_PROG_TYPE_CGROUP_SOCK,
930 BPF_PROG_TYPE_LWT_IN,
931 BPF_PROG_TYPE_LWT_OUT,
932 BPF_PROG_TYPE_LWT_XMIT,
933 BPF_PROG_TYPE_SOCK_OPS,
934 BPF_PROG_TYPE_SK_SKB,
935 BPF_PROG_TYPE_CGROUP_DEVICE,
936 BPF_PROG_TYPE_SK_MSG,
937 BPF_PROG_TYPE_RAW_TRACEPOINT,
938 BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
939 BPF_PROG_TYPE_LWT_SEG6LOCAL,
940 BPF_PROG_TYPE_LIRC_MODE2,
941 BPF_PROG_TYPE_SK_REUSEPORT,
942 BPF_PROG_TYPE_FLOW_DISSECTOR,
943 BPF_PROG_TYPE_CGROUP_SYSCTL,
944 BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
945 BPF_PROG_TYPE_CGROUP_SOCKOPT,
946 BPF_PROG_TYPE_TRACING,
947 BPF_PROG_TYPE_STRUCT_OPS,
950 BPF_PROG_TYPE_SK_LOOKUP,
951 BPF_PROG_TYPE_SYSCALL, /* a program that can execute syscalls */
954 enum bpf_attach_type {
955 BPF_CGROUP_INET_INGRESS,
956 BPF_CGROUP_INET_EGRESS,
957 BPF_CGROUP_INET_SOCK_CREATE,
959 BPF_SK_SKB_STREAM_PARSER,
960 BPF_SK_SKB_STREAM_VERDICT,
963 BPF_CGROUP_INET4_BIND,
964 BPF_CGROUP_INET6_BIND,
965 BPF_CGROUP_INET4_CONNECT,
966 BPF_CGROUP_INET6_CONNECT,
967 BPF_CGROUP_INET4_POST_BIND,
968 BPF_CGROUP_INET6_POST_BIND,
969 BPF_CGROUP_UDP4_SENDMSG,
970 BPF_CGROUP_UDP6_SENDMSG,
974 BPF_CGROUP_UDP4_RECVMSG,
975 BPF_CGROUP_UDP6_RECVMSG,
976 BPF_CGROUP_GETSOCKOPT,
977 BPF_CGROUP_SETSOCKOPT,
984 BPF_CGROUP_INET4_GETPEERNAME,
985 BPF_CGROUP_INET6_GETPEERNAME,
986 BPF_CGROUP_INET4_GETSOCKNAME,
987 BPF_CGROUP_INET6_GETSOCKNAME,
989 BPF_CGROUP_INET_SOCK_RELEASE,
994 BPF_SK_REUSEPORT_SELECT,
995 BPF_SK_REUSEPORT_SELECT_OR_MIGRATE,
997 __MAX_BPF_ATTACH_TYPE
1000 #define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
1002 enum bpf_link_type {
1003 BPF_LINK_TYPE_UNSPEC = 0,
1004 BPF_LINK_TYPE_RAW_TRACEPOINT = 1,
1005 BPF_LINK_TYPE_TRACING = 2,
1006 BPF_LINK_TYPE_CGROUP = 3,
1007 BPF_LINK_TYPE_ITER = 4,
1008 BPF_LINK_TYPE_NETNS = 5,
1009 BPF_LINK_TYPE_XDP = 6,
1010 BPF_LINK_TYPE_PERF_EVENT = 7,
1015 /* cgroup-bpf attach flags used in BPF_PROG_ATTACH command
1017 * NONE(default): No further bpf programs allowed in the subtree.
1019 * BPF_F_ALLOW_OVERRIDE: If a sub-cgroup installs some bpf program,
1020 * the program in this cgroup yields to sub-cgroup program.
1022 * BPF_F_ALLOW_MULTI: If a sub-cgroup installs some bpf program,
1023 * that cgroup program gets run in addition to the program in this cgroup.
1025 * Only one program is allowed to be attached to a cgroup with
1026 * NONE or BPF_F_ALLOW_OVERRIDE flag.
1027 * Attaching another program on top of NONE or BPF_F_ALLOW_OVERRIDE will
1028 * release old program and attach the new one. Attach flags has to match.
1030 * Multiple programs are allowed to be attached to a cgroup with
1031 * BPF_F_ALLOW_MULTI flag. They are executed in FIFO order
1032 * (those that were attached first, run first)
1033 * The programs of sub-cgroup are executed first, then programs of
1034 * this cgroup and then programs of parent cgroup.
1035 * When children program makes decision (like picking TCP CA or sock bind)
1036 * parent program has a chance to override it.
1038 * With BPF_F_ALLOW_MULTI a new program is added to the end of the list of
1039 * programs for a cgroup. Though it's possible to replace an old program at
1040 * any position by also specifying BPF_F_REPLACE flag and position itself in
1041 * replace_bpf_fd attribute. Old program at this position will be released.
1043 * A cgroup with MULTI or OVERRIDE flag allows any attach flags in sub-cgroups.
1044 * A cgroup with NONE doesn't allow any programs in sub-cgroups.
1046 * cgrp1 (MULTI progs A, B) ->
1047 * cgrp2 (OVERRIDE prog C) ->
1048 * cgrp3 (MULTI prog D) ->
1049 * cgrp4 (OVERRIDE prog E) ->
1050 * cgrp5 (NONE prog F)
1051 * the event in cgrp5 triggers execution of F,D,A,B in that order.
1052 * if prog F is detached, the execution is E,D,A,B
1053 * if prog F and D are detached, the execution is E,A,B
1054 * if prog F, E and D are detached, the execution is C,A,B
1056 * All eligible programs are executed regardless of return code from
1059 #define BPF_F_ALLOW_OVERRIDE (1U << 0)
1060 #define BPF_F_ALLOW_MULTI (1U << 1)
1061 #define BPF_F_REPLACE (1U << 2)
1063 /* If BPF_F_STRICT_ALIGNMENT is used in BPF_PROG_LOAD command, the
1064 * verifier will perform strict alignment checking as if the kernel
1065 * has been built with CONFIG_EFFICIENT_UNALIGNED_ACCESS not set,
1066 * and NET_IP_ALIGN defined to 2.
1068 #define BPF_F_STRICT_ALIGNMENT (1U << 0)
1070 /* If BPF_F_ANY_ALIGNMENT is used in BPF_PROF_LOAD command, the
1071 * verifier will allow any alignment whatsoever. On platforms
1072 * with strict alignment requirements for loads ands stores (such
1073 * as sparc and mips) the verifier validates that all loads and
1074 * stores provably follow this requirement. This flag turns that
1075 * checking and enforcement off.
1077 * It is mostly used for testing when we want to validate the
1078 * context and memory access aspects of the verifier, but because
1079 * of an unaligned access the alignment check would trigger before
1080 * the one we are interested in.
1082 #define BPF_F_ANY_ALIGNMENT (1U << 1)
1084 /* BPF_F_TEST_RND_HI32 is used in BPF_PROG_LOAD command for testing purpose.
1085 * Verifier does sub-register def/use analysis and identifies instructions whose
1086 * def only matters for low 32-bit, high 32-bit is never referenced later
1087 * through implicit zero extension. Therefore verifier notifies JIT back-ends
1088 * that it is safe to ignore clearing high 32-bit for these instructions. This
1089 * saves some back-ends a lot of code-gen. However such optimization is not
1090 * necessary on some arches, for example x86_64, arm64 etc, whose JIT back-ends
1091 * hence hasn't used verifier's analysis result. But, we really want to have a
1092 * way to be able to verify the correctness of the described optimization on
1093 * x86_64 on which testsuites are frequently exercised.
1095 * So, this flag is introduced. Once it is set, verifier will randomize high
1096 * 32-bit for those instructions who has been identified as safe to ignore them.
1097 * Then, if verifier is not doing correct analysis, such randomization will
1098 * regress tests to expose bugs.
1100 #define BPF_F_TEST_RND_HI32 (1U << 2)
1102 /* The verifier internal test flag. Behavior is undefined */
1103 #define BPF_F_TEST_STATE_FREQ (1U << 3)
1105 /* If BPF_F_SLEEPABLE is used in BPF_PROG_LOAD command, the verifier will
1106 * restrict map and helper usage for such programs. Sleepable BPF programs can
1107 * only be attached to hooks where kernel execution context allows sleeping.
1108 * Such programs are allowed to use helpers that may sleep like
1109 * bpf_copy_from_user().
1111 #define BPF_F_SLEEPABLE (1U << 4)
1113 /* When BPF ldimm64's insn[0].src_reg != 0 then this can have
1114 * the following extensions:
1116 * insn[0].src_reg: BPF_PSEUDO_MAP_[FD|IDX]
1117 * insn[0].imm: map fd or fd_idx
1121 * ldimm64 rewrite: address of map
1122 * verifier type: CONST_PTR_TO_MAP
1124 #define BPF_PSEUDO_MAP_FD 1
1125 #define BPF_PSEUDO_MAP_IDX 5
1127 /* insn[0].src_reg: BPF_PSEUDO_MAP_[IDX_]VALUE
1128 * insn[0].imm: map fd or fd_idx
1129 * insn[1].imm: offset into value
1132 * ldimm64 rewrite: address of map[0]+offset
1133 * verifier type: PTR_TO_MAP_VALUE
1135 #define BPF_PSEUDO_MAP_VALUE 2
1136 #define BPF_PSEUDO_MAP_IDX_VALUE 6
1138 /* insn[0].src_reg: BPF_PSEUDO_BTF_ID
1139 * insn[0].imm: kernel btd id of VAR
1143 * ldimm64 rewrite: address of the kernel variable
1144 * verifier type: PTR_TO_BTF_ID or PTR_TO_MEM, depending on whether the var
1147 #define BPF_PSEUDO_BTF_ID 3
1148 /* insn[0].src_reg: BPF_PSEUDO_FUNC
1149 * insn[0].imm: insn offset to the func
1153 * ldimm64 rewrite: address of the function
1154 * verifier type: PTR_TO_FUNC.
1156 #define BPF_PSEUDO_FUNC 4
1158 /* when bpf_call->src_reg == BPF_PSEUDO_CALL, bpf_call->imm == pc-relative
1159 * offset to another bpf function
1161 #define BPF_PSEUDO_CALL 1
1162 /* when bpf_call->src_reg == BPF_PSEUDO_KFUNC_CALL,
1163 * bpf_call->imm == btf_id of a BTF_KIND_FUNC in the running kernel
1165 #define BPF_PSEUDO_KFUNC_CALL 2
1167 /* flags for BPF_MAP_UPDATE_ELEM command */
1169 BPF_ANY = 0, /* create new element or update existing */
1170 BPF_NOEXIST = 1, /* create new element if it didn't exist */
1171 BPF_EXIST = 2, /* update existing element */
1172 BPF_F_LOCK = 4, /* spin_lock-ed map_lookup/map_update */
1175 /* flags for BPF_MAP_CREATE command */
1177 BPF_F_NO_PREALLOC = (1U << 0),
1178 /* Instead of having one common LRU list in the
1179 * BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list
1180 * which can scale and perform better.
1181 * Note, the LRU nodes (including free nodes) cannot be moved
1182 * across different LRU lists.
1184 BPF_F_NO_COMMON_LRU = (1U << 1),
1185 /* Specify numa node during map creation */
1186 BPF_F_NUMA_NODE = (1U << 2),
1188 /* Flags for accessing BPF object from syscall side. */
1189 BPF_F_RDONLY = (1U << 3),
1190 BPF_F_WRONLY = (1U << 4),
1192 /* Flag for stack_map, store build_id+offset instead of pointer */
1193 BPF_F_STACK_BUILD_ID = (1U << 5),
1195 /* Zero-initialize hash function seed. This should only be used for testing. */
1196 BPF_F_ZERO_SEED = (1U << 6),
1198 /* Flags for accessing BPF object from program side. */
1199 BPF_F_RDONLY_PROG = (1U << 7),
1200 BPF_F_WRONLY_PROG = (1U << 8),
1202 /* Clone map from listener for newly accepted socket */
1203 BPF_F_CLONE = (1U << 9),
1205 /* Enable memory-mapping BPF map */
1206 BPF_F_MMAPABLE = (1U << 10),
1208 /* Share perf_event among processes */
1209 BPF_F_PRESERVE_ELEMS = (1U << 11),
1211 /* Create a map that is suitable to be an inner map with dynamic max entries */
1212 BPF_F_INNER_MAP = (1U << 12),
1215 /* Flags for BPF_PROG_QUERY. */
1217 /* Query effective (directly attached + inherited from ancestor cgroups)
1218 * programs that will be executed for events within a cgroup.
1219 * attach_flags with this flag are returned only for directly attached programs.
1221 #define BPF_F_QUERY_EFFECTIVE (1U << 0)
1223 /* Flags for BPF_PROG_TEST_RUN */
1225 /* If set, run the test on the cpu specified by bpf_attr.test.cpu */
1226 #define BPF_F_TEST_RUN_ON_CPU (1U << 0)
1228 /* type for BPF_ENABLE_STATS */
1229 enum bpf_stats_type {
1230 /* enabled run_time_ns and run_cnt */
1231 BPF_STATS_RUN_TIME = 0,
1234 enum bpf_stack_build_id_status {
1235 /* user space need an empty entry to identify end of a trace */
1236 BPF_STACK_BUILD_ID_EMPTY = 0,
1237 /* with valid build_id and offset */
1238 BPF_STACK_BUILD_ID_VALID = 1,
1239 /* couldn't get build_id, fallback to ip */
1240 BPF_STACK_BUILD_ID_IP = 2,
1243 #define BPF_BUILD_ID_SIZE 20
1244 struct bpf_stack_build_id {
1246 unsigned char build_id[BPF_BUILD_ID_SIZE];
1253 #define BPF_OBJ_NAME_LEN 16U
1256 struct { /* anonymous struct used by BPF_MAP_CREATE command */
1257 __u32 map_type; /* one of enum bpf_map_type */
1258 __u32 key_size; /* size of key in bytes */
1259 __u32 value_size; /* size of value in bytes */
1260 __u32 max_entries; /* max number of entries in a map */
1261 __u32 map_flags; /* BPF_MAP_CREATE related
1262 * flags defined above.
1264 __u32 inner_map_fd; /* fd pointing to the inner map */
1265 __u32 numa_node; /* numa node (effective only if
1266 * BPF_F_NUMA_NODE is set).
1268 char map_name[BPF_OBJ_NAME_LEN];
1269 __u32 map_ifindex; /* ifindex of netdev to create on */
1270 __u32 btf_fd; /* fd pointing to a BTF type data */
1271 __u32 btf_key_type_id; /* BTF type_id of the key */
1272 __u32 btf_value_type_id; /* BTF type_id of the value */
1273 __u32 btf_vmlinux_value_type_id;/* BTF type_id of a kernel-
1274 * struct stored as the
1279 struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
1283 __aligned_u64 value;
1284 __aligned_u64 next_key;
1289 struct { /* struct used by BPF_MAP_*_BATCH commands */
1290 __aligned_u64 in_batch; /* start batch,
1291 * NULL to start from beginning
1293 __aligned_u64 out_batch; /* output: next start batch */
1295 __aligned_u64 values;
1296 __u32 count; /* input/output:
1297 * input: # of key/value
1299 * output: # of filled elements
1306 struct { /* anonymous struct used by BPF_PROG_LOAD command */
1307 __u32 prog_type; /* one of enum bpf_prog_type */
1309 __aligned_u64 insns;
1310 __aligned_u64 license;
1311 __u32 log_level; /* verbosity level of verifier */
1312 __u32 log_size; /* size of user buffer */
1313 __aligned_u64 log_buf; /* user supplied buffer */
1314 __u32 kern_version; /* not used */
1316 char prog_name[BPF_OBJ_NAME_LEN];
1317 __u32 prog_ifindex; /* ifindex of netdev to prep for */
1318 /* For some prog types expected attach type must be known at
1319 * load time to verify attach type specific parts of prog
1320 * (context accesses, allowed helpers, etc).
1322 __u32 expected_attach_type;
1323 __u32 prog_btf_fd; /* fd pointing to BTF type data */
1324 __u32 func_info_rec_size; /* userspace bpf_func_info size */
1325 __aligned_u64 func_info; /* func info */
1326 __u32 func_info_cnt; /* number of bpf_func_info records */
1327 __u32 line_info_rec_size; /* userspace bpf_line_info size */
1328 __aligned_u64 line_info; /* line info */
1329 __u32 line_info_cnt; /* number of bpf_line_info records */
1330 __u32 attach_btf_id; /* in-kernel BTF type id to attach to */
1332 /* valid prog_fd to attach to bpf prog */
1333 __u32 attach_prog_fd;
1334 /* or valid module BTF object fd or 0 to attach to vmlinux */
1335 __u32 attach_btf_obj_fd;
1337 __u32 :32; /* pad */
1338 __aligned_u64 fd_array; /* array of FDs */
1341 struct { /* anonymous struct used by BPF_OBJ_* commands */
1342 __aligned_u64 pathname;
1347 struct { /* anonymous struct used by BPF_PROG_ATTACH/DETACH commands */
1348 __u32 target_fd; /* container object to attach to */
1349 __u32 attach_bpf_fd; /* eBPF program to attach */
1352 __u32 replace_bpf_fd; /* previously attached eBPF
1353 * program to replace if
1354 * BPF_F_REPLACE is used
1358 struct { /* anonymous struct used by BPF_PROG_TEST_RUN command */
1361 __u32 data_size_in; /* input: len of data_in */
1362 __u32 data_size_out; /* input/output: len of data_out
1363 * returns ENOSPC if data_out
1366 __aligned_u64 data_in;
1367 __aligned_u64 data_out;
1370 __u32 ctx_size_in; /* input: len of ctx_in */
1371 __u32 ctx_size_out; /* input/output: len of ctx_out
1372 * returns ENOSPC if ctx_out
1375 __aligned_u64 ctx_in;
1376 __aligned_u64 ctx_out;
1381 struct { /* anonymous struct used by BPF_*_GET_*_ID */
1393 struct { /* anonymous struct used by BPF_OBJ_GET_INFO_BY_FD */
1399 struct { /* anonymous struct used by BPF_PROG_QUERY command */
1400 __u32 target_fd; /* container object to query */
1404 __aligned_u64 prog_ids;
1408 struct { /* anonymous struct used by BPF_RAW_TRACEPOINT_OPEN command */
1413 struct { /* anonymous struct for BPF_BTF_LOAD */
1415 __aligned_u64 btf_log_buf;
1418 __u32 btf_log_level;
1422 __u32 pid; /* input: pid */
1423 __u32 fd; /* input: fd */
1424 __u32 flags; /* input: flags */
1425 __u32 buf_len; /* input/output: buf len */
1426 __aligned_u64 buf; /* input/output:
1427 * tp_name for tracepoint
1429 * filename for uprobe
1431 __u32 prog_id; /* output: prod_id */
1432 __u32 fd_type; /* output: BPF_FD_TYPE_* */
1433 __u64 probe_offset; /* output: probe_offset */
1434 __u64 probe_addr; /* output: probe_addr */
1437 struct { /* struct used by BPF_LINK_CREATE command */
1438 __u32 prog_fd; /* eBPF program to attach */
1440 __u32 target_fd; /* object to attach to */
1441 __u32 target_ifindex; /* target ifindex */
1443 __u32 attach_type; /* attach type */
1444 __u32 flags; /* extra flags */
1446 __u32 target_btf_id; /* btf_id of target to attach to */
1448 __aligned_u64 iter_info; /* extra bpf_iter_link_info */
1449 __u32 iter_info_len; /* iter_info length */
1452 /* black box user-provided value passed through
1453 * to BPF program at the execution time and
1454 * accessible through bpf_get_attach_cookie() BPF helper
1461 struct { /* struct used by BPF_LINK_UPDATE command */
1462 __u32 link_fd; /* link fd */
1463 /* new program fd to update link with */
1465 __u32 flags; /* extra flags */
1466 /* expected link's program fd; is specified only if
1467 * BPF_F_REPLACE flag is set in flags */
1475 struct { /* struct used by BPF_ENABLE_STATS command */
1479 struct { /* struct used by BPF_ITER_CREATE command */
1484 struct { /* struct used by BPF_PROG_BIND_MAP command */
1487 __u32 flags; /* extra flags */
1490 } __attribute__((aligned(8)));
1492 /* The description below is an attempt at providing documentation to eBPF
1493 * developers about the multiple available eBPF helper functions. It can be
1494 * parsed and used to produce a manual page. The workflow is the following,
1495 * and requires the rst2man utility:
1497 * $ ./scripts/bpf_doc.py \
1498 * --filename include/uapi/linux/bpf.h > /tmp/bpf-helpers.rst
1499 * $ rst2man /tmp/bpf-helpers.rst > /tmp/bpf-helpers.7
1500 * $ man /tmp/bpf-helpers.7
1502 * Note that in order to produce this external documentation, some RST
1503 * formatting is used in the descriptions to get "bold" and "italics" in
1504 * manual pages. Also note that the few trailing white spaces are
1505 * intentional, removing them would break paragraphs for rst2man.
1507 * Start of BPF helper function descriptions:
1509 * void *bpf_map_lookup_elem(struct bpf_map *map, const void *key)
1511 * Perform a lookup in *map* for an entry associated to *key*.
1513 * Map value associated to *key*, or **NULL** if no entry was
1516 * long bpf_map_update_elem(struct bpf_map *map, const void *key, const void *value, u64 flags)
1518 * Add or update the value of the entry associated to *key* in
1519 * *map* with *value*. *flags* is one of:
1522 * The entry for *key* must not exist in the map.
1524 * The entry for *key* must already exist in the map.
1526 * No condition on the existence of the entry for *key*.
1528 * Flag value **BPF_NOEXIST** cannot be used for maps of types
1529 * **BPF_MAP_TYPE_ARRAY** or **BPF_MAP_TYPE_PERCPU_ARRAY** (all
1530 * elements always exist), the helper would return an error.
1532 * 0 on success, or a negative error in case of failure.
1534 * long bpf_map_delete_elem(struct bpf_map *map, const void *key)
1536 * Delete entry with *key* from *map*.
1538 * 0 on success, or a negative error in case of failure.
1540 * long bpf_probe_read(void *dst, u32 size, const void *unsafe_ptr)
1542 * For tracing programs, safely attempt to read *size* bytes from
1543 * kernel space address *unsafe_ptr* and store the data in *dst*.
1545 * Generally, use **bpf_probe_read_user**\ () or
1546 * **bpf_probe_read_kernel**\ () instead.
1548 * 0 on success, or a negative error in case of failure.
1550 * u64 bpf_ktime_get_ns(void)
1552 * Return the time elapsed since system boot, in nanoseconds.
1553 * Does not include time the system was suspended.
1554 * See: **clock_gettime**\ (**CLOCK_MONOTONIC**)
1558 * long bpf_trace_printk(const char *fmt, u32 fmt_size, ...)
1560 * This helper is a "printk()-like" facility for debugging. It
1561 * prints a message defined by format *fmt* (of size *fmt_size*)
1562 * to file *\/sys/kernel/debug/tracing/trace* from DebugFS, if
1563 * available. It can take up to three additional **u64**
1564 * arguments (as an eBPF helpers, the total number of arguments is
1567 * Each time the helper is called, it appends a line to the trace.
1568 * Lines are discarded while *\/sys/kernel/debug/tracing/trace* is
1569 * open, use *\/sys/kernel/debug/tracing/trace_pipe* to avoid this.
1570 * The format of the trace is customizable, and the exact output
1571 * one will get depends on the options set in
1572 * *\/sys/kernel/debug/tracing/trace_options* (see also the
1573 * *README* file under the same directory). However, it usually
1574 * defaults to something like:
1578 * telnet-470 [001] .N.. 419421.045894: 0x00000001: <formatted msg>
1582 * * ``telnet`` is the name of the current task.
1583 * * ``470`` is the PID of the current task.
1584 * * ``001`` is the CPU number on which the task is
1586 * * In ``.N..``, each character refers to a set of
1587 * options (whether irqs are enabled, scheduling
1588 * options, whether hard/softirqs are running, level of
1589 * preempt_disabled respectively). **N** means that
1590 * **TIF_NEED_RESCHED** and **PREEMPT_NEED_RESCHED**
1592 * * ``419421.045894`` is a timestamp.
1593 * * ``0x00000001`` is a fake value used by BPF for the
1594 * instruction pointer register.
1595 * * ``<formatted msg>`` is the message formatted with
1598 * The conversion specifiers supported by *fmt* are similar, but
1599 * more limited than for printk(). They are **%d**, **%i**,
1600 * **%u**, **%x**, **%ld**, **%li**, **%lu**, **%lx**, **%lld**,
1601 * **%lli**, **%llu**, **%llx**, **%p**, **%s**. No modifier (size
1602 * of field, padding with zeroes, etc.) is available, and the
1603 * helper will return **-EINVAL** (but print nothing) if it
1604 * encounters an unknown specifier.
1606 * Also, note that **bpf_trace_printk**\ () is slow, and should
1607 * only be used for debugging purposes. For this reason, a notice
1608 * block (spanning several lines) is printed to kernel logs and
1609 * states that the helper should not be used "for production use"
1610 * the first time this helper is used (or more precisely, when
1611 * **trace_printk**\ () buffers are allocated). For passing values
1612 * to user space, perf events should be preferred.
1614 * The number of bytes written to the buffer, or a negative error
1615 * in case of failure.
1617 * u32 bpf_get_prandom_u32(void)
1619 * Get a pseudo-random number.
1621 * From a security point of view, this helper uses its own
1622 * pseudo-random internal state, and cannot be used to infer the
1623 * seed of other random functions in the kernel. However, it is
1624 * essential to note that the generator used by the helper is not
1625 * cryptographically secure.
1627 * A random 32-bit unsigned value.
1629 * u32 bpf_get_smp_processor_id(void)
1631 * Get the SMP (symmetric multiprocessing) processor id. Note that
1632 * all programs run with preemption disabled, which means that the
1633 * SMP processor id is stable during all the execution of the
1636 * The SMP id of the processor running the program.
1638 * long bpf_skb_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len, u64 flags)
1640 * Store *len* bytes from address *from* into the packet
1641 * associated to *skb*, at *offset*. *flags* are a combination of
1642 * **BPF_F_RECOMPUTE_CSUM** (automatically recompute the
1643 * checksum for the packet after storing the bytes) and
1644 * **BPF_F_INVALIDATE_HASH** (set *skb*\ **->hash**, *skb*\
1645 * **->swhash** and *skb*\ **->l4hash** to 0).
1647 * A call to this helper is susceptible to change the underlying
1648 * packet buffer. Therefore, at load time, all checks on pointers
1649 * previously done by the verifier are invalidated and must be
1650 * performed again, if the helper is used in combination with
1651 * direct packet access.
1653 * 0 on success, or a negative error in case of failure.
1655 * long bpf_l3_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 size)
1657 * Recompute the layer 3 (e.g. IP) checksum for the packet
1658 * associated to *skb*. Computation is incremental, so the helper
1659 * must know the former value of the header field that was
1660 * modified (*from*), the new value of this field (*to*), and the
1661 * number of bytes (2 or 4) for this field, stored in *size*.
1662 * Alternatively, it is possible to store the difference between
1663 * the previous and the new values of the header field in *to*, by
1664 * setting *from* and *size* to 0. For both methods, *offset*
1665 * indicates the location of the IP checksum within the packet.
1667 * This helper works in combination with **bpf_csum_diff**\ (),
1668 * which does not update the checksum in-place, but offers more
1669 * flexibility and can handle sizes larger than 2 or 4 for the
1670 * checksum to update.
1672 * A call to this helper is susceptible to change the underlying
1673 * packet buffer. Therefore, at load time, all checks on pointers
1674 * previously done by the verifier are invalidated and must be
1675 * performed again, if the helper is used in combination with
1676 * direct packet access.
1678 * 0 on success, or a negative error in case of failure.
1680 * long bpf_l4_csum_replace(struct sk_buff *skb, u32 offset, u64 from, u64 to, u64 flags)
1682 * Recompute the layer 4 (e.g. TCP, UDP or ICMP) checksum for the
1683 * packet associated to *skb*. Computation is incremental, so the
1684 * helper must know the former value of the header field that was
1685 * modified (*from*), the new value of this field (*to*), and the
1686 * number of bytes (2 or 4) for this field, stored on the lowest
1687 * four bits of *flags*. Alternatively, it is possible to store
1688 * the difference between the previous and the new values of the
1689 * header field in *to*, by setting *from* and the four lowest
1690 * bits of *flags* to 0. For both methods, *offset* indicates the
1691 * location of the IP checksum within the packet. In addition to
1692 * the size of the field, *flags* can be added (bitwise OR) actual
1693 * flags. With **BPF_F_MARK_MANGLED_0**, a null checksum is left
1694 * untouched (unless **BPF_F_MARK_ENFORCE** is added as well), and
1695 * for updates resulting in a null checksum the value is set to
1696 * **CSUM_MANGLED_0** instead. Flag **BPF_F_PSEUDO_HDR** indicates
1697 * the checksum is to be computed against a pseudo-header.
1699 * This helper works in combination with **bpf_csum_diff**\ (),
1700 * which does not update the checksum in-place, but offers more
1701 * flexibility and can handle sizes larger than 2 or 4 for the
1702 * checksum to update.
1704 * A call to this helper is susceptible to change the underlying
1705 * packet buffer. Therefore, at load time, all checks on pointers
1706 * previously done by the verifier are invalidated and must be
1707 * performed again, if the helper is used in combination with
1708 * direct packet access.
1710 * 0 on success, or a negative error in case of failure.
1712 * long bpf_tail_call(void *ctx, struct bpf_map *prog_array_map, u32 index)
1714 * This special helper is used to trigger a "tail call", or in
1715 * other words, to jump into another eBPF program. The same stack
1716 * frame is used (but values on stack and in registers for the
1717 * caller are not accessible to the callee). This mechanism allows
1718 * for program chaining, either for raising the maximum number of
1719 * available eBPF instructions, or to execute given programs in
1720 * conditional blocks. For security reasons, there is an upper
1721 * limit to the number of successive tail calls that can be
1724 * Upon call of this helper, the program attempts to jump into a
1725 * program referenced at index *index* in *prog_array_map*, a
1726 * special map of type **BPF_MAP_TYPE_PROG_ARRAY**, and passes
1727 * *ctx*, a pointer to the context.
1729 * If the call succeeds, the kernel immediately runs the first
1730 * instruction of the new program. This is not a function call,
1731 * and it never returns to the previous program. If the call
1732 * fails, then the helper has no effect, and the caller continues
1733 * to run its subsequent instructions. A call can fail if the
1734 * destination program for the jump does not exist (i.e. *index*
1735 * is superior to the number of entries in *prog_array_map*), or
1736 * if the maximum number of tail calls has been reached for this
1737 * chain of programs. This limit is defined in the kernel by the
1738 * macro **MAX_TAIL_CALL_CNT** (not accessible to user space),
1739 * which is currently set to 32.
1741 * 0 on success, or a negative error in case of failure.
1743 * long bpf_clone_redirect(struct sk_buff *skb, u32 ifindex, u64 flags)
1745 * Clone and redirect the packet associated to *skb* to another
1746 * net device of index *ifindex*. Both ingress and egress
1747 * interfaces can be used for redirection. The **BPF_F_INGRESS**
1748 * value in *flags* is used to make the distinction (ingress path
1749 * is selected if the flag is present, egress path otherwise).
1750 * This is the only flag supported for now.
1752 * In comparison with **bpf_redirect**\ () helper,
1753 * **bpf_clone_redirect**\ () has the associated cost of
1754 * duplicating the packet buffer, but this can be executed out of
1755 * the eBPF program. Conversely, **bpf_redirect**\ () is more
1756 * efficient, but it is handled through an action code where the
1757 * redirection happens only after the eBPF program has returned.
1759 * A call to this helper is susceptible to change the underlying
1760 * packet buffer. Therefore, at load time, all checks on pointers
1761 * previously done by the verifier are invalidated and must be
1762 * performed again, if the helper is used in combination with
1763 * direct packet access.
1765 * 0 on success, or a negative error in case of failure.
1767 * u64 bpf_get_current_pid_tgid(void)
1769 * A 64-bit integer containing the current tgid and pid, and
1771 * *current_task*\ **->tgid << 32 \|**
1772 * *current_task*\ **->pid**.
1774 * u64 bpf_get_current_uid_gid(void)
1776 * A 64-bit integer containing the current GID and UID, and
1777 * created as such: *current_gid* **<< 32 \|** *current_uid*.
1779 * long bpf_get_current_comm(void *buf, u32 size_of_buf)
1781 * Copy the **comm** attribute of the current task into *buf* of
1782 * *size_of_buf*. The **comm** attribute contains the name of
1783 * the executable (excluding the path) for the current task. The
1784 * *size_of_buf* must be strictly positive. On success, the
1785 * helper makes sure that the *buf* is NUL-terminated. On failure,
1786 * it is filled with zeroes.
1788 * 0 on success, or a negative error in case of failure.
1790 * u32 bpf_get_cgroup_classid(struct sk_buff *skb)
1792 * Retrieve the classid for the current task, i.e. for the net_cls
1793 * cgroup to which *skb* belongs.
1795 * This helper can be used on TC egress path, but not on ingress.
1797 * The net_cls cgroup provides an interface to tag network packets
1798 * based on a user-provided identifier for all traffic coming from
1799 * the tasks belonging to the related cgroup. See also the related
1800 * kernel documentation, available from the Linux sources in file
1801 * *Documentation/admin-guide/cgroup-v1/net_cls.rst*.
1803 * The Linux kernel has two versions for cgroups: there are
1804 * cgroups v1 and cgroups v2. Both are available to users, who can
1805 * use a mixture of them, but note that the net_cls cgroup is for
1806 * cgroup v1 only. This makes it incompatible with BPF programs
1807 * run on cgroups, which is a cgroup-v2-only feature (a socket can
1808 * only hold data for one version of cgroups at a time).
1810 * This helper is only available is the kernel was compiled with
1811 * the **CONFIG_CGROUP_NET_CLASSID** configuration option set to
1812 * "**y**" or to "**m**".
1814 * The classid, or 0 for the default unconfigured classid.
1816 * long bpf_skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci)
1818 * Push a *vlan_tci* (VLAN tag control information) of protocol
1819 * *vlan_proto* to the packet associated to *skb*, then update
1820 * the checksum. Note that if *vlan_proto* is different from
1821 * **ETH_P_8021Q** and **ETH_P_8021AD**, it is considered to
1822 * be **ETH_P_8021Q**.
1824 * A call to this helper is susceptible to change the underlying
1825 * packet buffer. Therefore, at load time, all checks on pointers
1826 * previously done by the verifier are invalidated and must be
1827 * performed again, if the helper is used in combination with
1828 * direct packet access.
1830 * 0 on success, or a negative error in case of failure.
1832 * long bpf_skb_vlan_pop(struct sk_buff *skb)
1834 * Pop a VLAN header from the packet associated to *skb*.
1836 * A call to this helper is susceptible to change the underlying
1837 * packet buffer. Therefore, at load time, all checks on pointers
1838 * previously done by the verifier are invalidated and must be
1839 * performed again, if the helper is used in combination with
1840 * direct packet access.
1842 * 0 on success, or a negative error in case of failure.
1844 * long bpf_skb_get_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags)
1846 * Get tunnel metadata. This helper takes a pointer *key* to an
1847 * empty **struct bpf_tunnel_key** of **size**, that will be
1848 * filled with tunnel metadata for the packet associated to *skb*.
1849 * The *flags* can be set to **BPF_F_TUNINFO_IPV6**, which
1850 * indicates that the tunnel is based on IPv6 protocol instead of
1853 * The **struct bpf_tunnel_key** is an object that generalizes the
1854 * principal parameters used by various tunneling protocols into a
1855 * single struct. This way, it can be used to easily make a
1856 * decision based on the contents of the encapsulation header,
1857 * "summarized" in this struct. In particular, it holds the IP
1858 * address of the remote end (IPv4 or IPv6, depending on the case)
1859 * in *key*\ **->remote_ipv4** or *key*\ **->remote_ipv6**. Also,
1860 * this struct exposes the *key*\ **->tunnel_id**, which is
1861 * generally mapped to a VNI (Virtual Network Identifier), making
1862 * it programmable together with the **bpf_skb_set_tunnel_key**\
1865 * Let's imagine that the following code is part of a program
1866 * attached to the TC ingress interface, on one end of a GRE
1867 * tunnel, and is supposed to filter out all messages coming from
1868 * remote ends with IPv4 address other than 10.0.0.1:
1873 * struct bpf_tunnel_key key = {};
1875 * ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
1877 * return TC_ACT_SHOT; // drop packet
1879 * if (key.remote_ipv4 != 0x0a000001)
1880 * return TC_ACT_SHOT; // drop packet
1882 * return TC_ACT_OK; // accept packet
1884 * This interface can also be used with all encapsulation devices
1885 * that can operate in "collect metadata" mode: instead of having
1886 * one network device per specific configuration, the "collect
1887 * metadata" mode only requires a single device where the
1888 * configuration can be extracted from this helper.
1890 * This can be used together with various tunnels such as VXLan,
1891 * Geneve, GRE or IP in IP (IPIP).
1893 * 0 on success, or a negative error in case of failure.
1895 * long bpf_skb_set_tunnel_key(struct sk_buff *skb, struct bpf_tunnel_key *key, u32 size, u64 flags)
1897 * Populate tunnel metadata for packet associated to *skb.* The
1898 * tunnel metadata is set to the contents of *key*, of *size*. The
1899 * *flags* can be set to a combination of the following values:
1901 * **BPF_F_TUNINFO_IPV6**
1902 * Indicate that the tunnel is based on IPv6 protocol
1904 * **BPF_F_ZERO_CSUM_TX**
1905 * For IPv4 packets, add a flag to tunnel metadata
1906 * indicating that checksum computation should be skipped
1907 * and checksum set to zeroes.
1908 * **BPF_F_DONT_FRAGMENT**
1909 * Add a flag to tunnel metadata indicating that the
1910 * packet should not be fragmented.
1911 * **BPF_F_SEQ_NUMBER**
1912 * Add a flag to tunnel metadata indicating that a
1913 * sequence number should be added to tunnel header before
1914 * sending the packet. This flag was added for GRE
1915 * encapsulation, but might be used with other protocols
1916 * as well in the future.
1918 * Here is a typical usage on the transmit path:
1922 * struct bpf_tunnel_key key;
1924 * bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0);
1925 * bpf_clone_redirect(skb, vxlan_dev_ifindex, 0);
1927 * See also the description of the **bpf_skb_get_tunnel_key**\ ()
1928 * helper for additional information.
1930 * 0 on success, or a negative error in case of failure.
1932 * u64 bpf_perf_event_read(struct bpf_map *map, u64 flags)
1934 * Read the value of a perf event counter. This helper relies on a
1935 * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of
1936 * the perf event counter is selected when *map* is updated with
1937 * perf event file descriptors. The *map* is an array whose size
1938 * is the number of available CPUs, and each cell contains a value
1939 * relative to one CPU. The value to retrieve is indicated by
1940 * *flags*, that contains the index of the CPU to look up, masked
1941 * with **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
1942 * **BPF_F_CURRENT_CPU** to indicate that the value for the
1943 * current CPU should be retrieved.
1945 * Note that before Linux 4.13, only hardware perf event can be
1948 * Also, be aware that the newer helper
1949 * **bpf_perf_event_read_value**\ () is recommended over
1950 * **bpf_perf_event_read**\ () in general. The latter has some ABI
1951 * quirks where error and counter value are used as a return code
1952 * (which is wrong to do since ranges may overlap). This issue is
1953 * fixed with **bpf_perf_event_read_value**\ (), which at the same
1954 * time provides more features over the **bpf_perf_event_read**\
1955 * () interface. Please refer to the description of
1956 * **bpf_perf_event_read_value**\ () for details.
1958 * The value of the perf event counter read from the map, or a
1959 * negative error code in case of failure.
1961 * long bpf_redirect(u32 ifindex, u64 flags)
1963 * Redirect the packet to another net device of index *ifindex*.
1964 * This helper is somewhat similar to **bpf_clone_redirect**\
1965 * (), except that the packet is not cloned, which provides
1966 * increased performance.
1968 * Except for XDP, both ingress and egress interfaces can be used
1969 * for redirection. The **BPF_F_INGRESS** value in *flags* is used
1970 * to make the distinction (ingress path is selected if the flag
1971 * is present, egress path otherwise). Currently, XDP only
1972 * supports redirection to the egress interface, and accepts no
1975 * The same effect can also be attained with the more generic
1976 * **bpf_redirect_map**\ (), which uses a BPF map to store the
1977 * redirect target instead of providing it directly to the helper.
1979 * For XDP, the helper returns **XDP_REDIRECT** on success or
1980 * **XDP_ABORTED** on error. For other program types, the values
1981 * are **TC_ACT_REDIRECT** on success or **TC_ACT_SHOT** on
1984 * u32 bpf_get_route_realm(struct sk_buff *skb)
1986 * Retrieve the realm or the route, that is to say the
1987 * **tclassid** field of the destination for the *skb*. The
1988 * identifier retrieved is a user-provided tag, similar to the
1989 * one used with the net_cls cgroup (see description for
1990 * **bpf_get_cgroup_classid**\ () helper), but here this tag is
1991 * held by a route (a destination entry), not by a task.
1993 * Retrieving this identifier works with the clsact TC egress hook
1994 * (see also **tc-bpf(8)**), or alternatively on conventional
1995 * classful egress qdiscs, but not on TC ingress path. In case of
1996 * clsact TC egress hook, this has the advantage that, internally,
1997 * the destination entry has not been dropped yet in the transmit
1998 * path. Therefore, the destination entry does not need to be
1999 * artificially held via **netif_keep_dst**\ () for a classful
2000 * qdisc until the *skb* is freed.
2002 * This helper is available only if the kernel was compiled with
2003 * **CONFIG_IP_ROUTE_CLASSID** configuration option.
2005 * The realm of the route for the packet associated to *skb*, or 0
2006 * if none was found.
2008 * long bpf_perf_event_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
2010 * Write raw *data* blob into a special BPF perf event held by
2011 * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
2012 * event must have the following attributes: **PERF_SAMPLE_RAW**
2013 * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
2014 * **PERF_COUNT_SW_BPF_OUTPUT** as **config**.
2016 * The *flags* are used to indicate the index in *map* for which
2017 * the value must be put, masked with **BPF_F_INDEX_MASK**.
2018 * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
2019 * to indicate that the index of the current CPU core should be
2022 * The value to write, of *size*, is passed through eBPF stack and
2023 * pointed by *data*.
2025 * The context of the program *ctx* needs also be passed to the
2028 * On user space, a program willing to read the values needs to
2029 * call **perf_event_open**\ () on the perf event (either for
2030 * one or for all CPUs) and to store the file descriptor into the
2031 * *map*. This must be done before the eBPF program can send data
2032 * into it. An example is available in file
2033 * *samples/bpf/trace_output_user.c* in the Linux kernel source
2034 * tree (the eBPF program counterpart is in
2035 * *samples/bpf/trace_output_kern.c*).
2037 * **bpf_perf_event_output**\ () achieves better performance
2038 * than **bpf_trace_printk**\ () for sharing data with user
2039 * space, and is much better suitable for streaming data from eBPF
2042 * Note that this helper is not restricted to tracing use cases
2043 * and can be used with programs attached to TC or XDP as well,
2044 * where it allows for passing data to user space listeners. Data
2047 * * Only custom structs,
2048 * * Only the packet payload, or
2049 * * A combination of both.
2051 * 0 on success, or a negative error in case of failure.
2053 * long bpf_skb_load_bytes(const void *skb, u32 offset, void *to, u32 len)
2055 * This helper was provided as an easy way to load data from a
2056 * packet. It can be used to load *len* bytes from *offset* from
2057 * the packet associated to *skb*, into the buffer pointed by
2060 * Since Linux 4.7, usage of this helper has mostly been replaced
2061 * by "direct packet access", enabling packet data to be
2062 * manipulated with *skb*\ **->data** and *skb*\ **->data_end**
2063 * pointing respectively to the first byte of packet data and to
2064 * the byte after the last byte of packet data. However, it
2065 * remains useful if one wishes to read large quantities of data
2066 * at once from a packet into the eBPF stack.
2068 * 0 on success, or a negative error in case of failure.
2070 * long bpf_get_stackid(void *ctx, struct bpf_map *map, u64 flags)
2072 * Walk a user or a kernel stack and return its id. To achieve
2073 * this, the helper needs *ctx*, which is a pointer to the context
2074 * on which the tracing program is executed, and a pointer to a
2075 * *map* of type **BPF_MAP_TYPE_STACK_TRACE**.
2077 * The last argument, *flags*, holds the number of stack frames to
2078 * skip (from 0 to 255), masked with
2079 * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
2080 * a combination of the following flags:
2082 * **BPF_F_USER_STACK**
2083 * Collect a user space stack instead of a kernel stack.
2084 * **BPF_F_FAST_STACK_CMP**
2085 * Compare stacks by hash only.
2086 * **BPF_F_REUSE_STACKID**
2087 * If two different stacks hash into the same *stackid*,
2088 * discard the old one.
2090 * The stack id retrieved is a 32 bit long integer handle which
2091 * can be further combined with other data (including other stack
2092 * ids) and used as a key into maps. This can be useful for
2093 * generating a variety of graphs (such as flame graphs or off-cpu
2096 * For walking a stack, this helper is an improvement over
2097 * **bpf_probe_read**\ (), which can be used with unrolled loops
2098 * but is not efficient and consumes a lot of eBPF instructions.
2099 * Instead, **bpf_get_stackid**\ () can collect up to
2100 * **PERF_MAX_STACK_DEPTH** both kernel and user frames. Note that
2101 * this limit can be controlled with the **sysctl** program, and
2102 * that it should be manually increased in order to profile long
2103 * user stacks (such as stacks for Java programs). To do so, use:
2107 * # sysctl kernel.perf_event_max_stack=<new value>
2109 * The positive or null stack id on success, or a negative error
2110 * in case of failure.
2112 * s64 bpf_csum_diff(__be32 *from, u32 from_size, __be32 *to, u32 to_size, __wsum seed)
2114 * Compute a checksum difference, from the raw buffer pointed by
2115 * *from*, of length *from_size* (that must be a multiple of 4),
2116 * towards the raw buffer pointed by *to*, of size *to_size*
2117 * (same remark). An optional *seed* can be added to the value
2118 * (this can be cascaded, the seed may come from a previous call
2121 * This is flexible enough to be used in several ways:
2123 * * With *from_size* == 0, *to_size* > 0 and *seed* set to
2124 * checksum, it can be used when pushing new data.
2125 * * With *from_size* > 0, *to_size* == 0 and *seed* set to
2126 * checksum, it can be used when removing data from a packet.
2127 * * With *from_size* > 0, *to_size* > 0 and *seed* set to 0, it
2128 * can be used to compute a diff. Note that *from_size* and
2129 * *to_size* do not need to be equal.
2131 * This helper can be used in combination with
2132 * **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ (), to
2133 * which one can feed in the difference computed with
2134 * **bpf_csum_diff**\ ().
2136 * The checksum result, or a negative error code in case of
2139 * long bpf_skb_get_tunnel_opt(struct sk_buff *skb, void *opt, u32 size)
2141 * Retrieve tunnel options metadata for the packet associated to
2142 * *skb*, and store the raw tunnel option data to the buffer *opt*
2145 * This helper can be used with encapsulation devices that can
2146 * operate in "collect metadata" mode (please refer to the related
2147 * note in the description of **bpf_skb_get_tunnel_key**\ () for
2148 * more details). A particular example where this can be used is
2149 * in combination with the Geneve encapsulation protocol, where it
2150 * allows for pushing (with **bpf_skb_get_tunnel_opt**\ () helper)
2151 * and retrieving arbitrary TLVs (Type-Length-Value headers) from
2152 * the eBPF program. This allows for full customization of these
2155 * The size of the option data retrieved.
2157 * long bpf_skb_set_tunnel_opt(struct sk_buff *skb, void *opt, u32 size)
2159 * Set tunnel options metadata for the packet associated to *skb*
2160 * to the option data contained in the raw buffer *opt* of *size*.
2162 * See also the description of the **bpf_skb_get_tunnel_opt**\ ()
2163 * helper for additional information.
2165 * 0 on success, or a negative error in case of failure.
2167 * long bpf_skb_change_proto(struct sk_buff *skb, __be16 proto, u64 flags)
2169 * Change the protocol of the *skb* to *proto*. Currently
2170 * supported are transition from IPv4 to IPv6, and from IPv6 to
2171 * IPv4. The helper takes care of the groundwork for the
2172 * transition, including resizing the socket buffer. The eBPF
2173 * program is expected to fill the new headers, if any, via
2174 * **skb_store_bytes**\ () and to recompute the checksums with
2175 * **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\
2176 * (). The main case for this helper is to perform NAT64
2177 * operations out of an eBPF program.
2179 * Internally, the GSO type is marked as dodgy so that headers are
2180 * checked and segments are recalculated by the GSO/GRO engine.
2181 * The size for GSO target is adapted as well.
2183 * All values for *flags* are reserved for future usage, and must
2186 * A call to this helper is susceptible to change the underlying
2187 * packet buffer. Therefore, at load time, all checks on pointers
2188 * previously done by the verifier are invalidated and must be
2189 * performed again, if the helper is used in combination with
2190 * direct packet access.
2192 * 0 on success, or a negative error in case of failure.
2194 * long bpf_skb_change_type(struct sk_buff *skb, u32 type)
2196 * Change the packet type for the packet associated to *skb*. This
2197 * comes down to setting *skb*\ **->pkt_type** to *type*, except
2198 * the eBPF program does not have a write access to *skb*\
2199 * **->pkt_type** beside this helper. Using a helper here allows
2200 * for graceful handling of errors.
2202 * The major use case is to change incoming *skb*s to
2203 * **PACKET_HOST** in a programmatic way instead of having to
2204 * recirculate via **redirect**\ (..., **BPF_F_INGRESS**), for
2207 * Note that *type* only allows certain values. At this time, they
2212 * **PACKET_BROADCAST**
2213 * Send packet to all.
2214 * **PACKET_MULTICAST**
2215 * Send packet to group.
2216 * **PACKET_OTHERHOST**
2217 * Send packet to someone else.
2219 * 0 on success, or a negative error in case of failure.
2221 * long bpf_skb_under_cgroup(struct sk_buff *skb, struct bpf_map *map, u32 index)
2223 * Check whether *skb* is a descendant of the cgroup2 held by
2224 * *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
2226 * The return value depends on the result of the test, and can be:
2228 * * 0, if the *skb* failed the cgroup2 descendant test.
2229 * * 1, if the *skb* succeeded the cgroup2 descendant test.
2230 * * A negative error code, if an error occurred.
2232 * u32 bpf_get_hash_recalc(struct sk_buff *skb)
2234 * Retrieve the hash of the packet, *skb*\ **->hash**. If it is
2235 * not set, in particular if the hash was cleared due to mangling,
2236 * recompute this hash. Later accesses to the hash can be done
2237 * directly with *skb*\ **->hash**.
2239 * Calling **bpf_set_hash_invalid**\ (), changing a packet
2240 * prototype with **bpf_skb_change_proto**\ (), or calling
2241 * **bpf_skb_store_bytes**\ () with the
2242 * **BPF_F_INVALIDATE_HASH** are actions susceptible to clear
2243 * the hash and to trigger a new computation for the next call to
2244 * **bpf_get_hash_recalc**\ ().
2248 * u64 bpf_get_current_task(void)
2250 * A pointer to the current task struct.
2252 * long bpf_probe_write_user(void *dst, const void *src, u32 len)
2254 * Attempt in a safe way to write *len* bytes from the buffer
2255 * *src* to *dst* in memory. It only works for threads that are in
2256 * user context, and *dst* must be a valid user space address.
2258 * This helper should not be used to implement any kind of
2259 * security mechanism because of TOC-TOU attacks, but rather to
2260 * debug, divert, and manipulate execution of semi-cooperative
2263 * Keep in mind that this feature is meant for experiments, and it
2264 * has a risk of crashing the system and running programs.
2265 * Therefore, when an eBPF program using this helper is attached,
2266 * a warning including PID and process name is printed to kernel
2269 * 0 on success, or a negative error in case of failure.
2271 * long bpf_current_task_under_cgroup(struct bpf_map *map, u32 index)
2273 * Check whether the probe is being run is the context of a given
2274 * subset of the cgroup2 hierarchy. The cgroup2 to test is held by
2275 * *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
2277 * The return value depends on the result of the test, and can be:
2279 * * 0, if current task belongs to the cgroup2.
2280 * * 1, if current task does not belong to the cgroup2.
2281 * * A negative error code, if an error occurred.
2283 * long bpf_skb_change_tail(struct sk_buff *skb, u32 len, u64 flags)
2285 * Resize (trim or grow) the packet associated to *skb* to the
2286 * new *len*. The *flags* are reserved for future usage, and must
2289 * The basic idea is that the helper performs the needed work to
2290 * change the size of the packet, then the eBPF program rewrites
2291 * the rest via helpers like **bpf_skb_store_bytes**\ (),
2292 * **bpf_l3_csum_replace**\ (), **bpf_l3_csum_replace**\ ()
2293 * and others. This helper is a slow path utility intended for
2294 * replies with control messages. And because it is targeted for
2295 * slow path, the helper itself can afford to be slow: it
2296 * implicitly linearizes, unclones and drops offloads from the
2299 * A call to this helper is susceptible to change the underlying
2300 * packet buffer. Therefore, at load time, all checks on pointers
2301 * previously done by the verifier are invalidated and must be
2302 * performed again, if the helper is used in combination with
2303 * direct packet access.
2305 * 0 on success, or a negative error in case of failure.
2307 * long bpf_skb_pull_data(struct sk_buff *skb, u32 len)
2309 * Pull in non-linear data in case the *skb* is non-linear and not
2310 * all of *len* are part of the linear section. Make *len* bytes
2311 * from *skb* readable and writable. If a zero value is passed for
2312 * *len*, then the whole length of the *skb* is pulled.
2314 * This helper is only needed for reading and writing with direct
2317 * For direct packet access, testing that offsets to access
2318 * are within packet boundaries (test on *skb*\ **->data_end**) is
2319 * susceptible to fail if offsets are invalid, or if the requested
2320 * data is in non-linear parts of the *skb*. On failure the
2321 * program can just bail out, or in the case of a non-linear
2322 * buffer, use a helper to make the data available. The
2323 * **bpf_skb_load_bytes**\ () helper is a first solution to access
2324 * the data. Another one consists in using **bpf_skb_pull_data**
2325 * to pull in once the non-linear parts, then retesting and
2326 * eventually access the data.
2328 * At the same time, this also makes sure the *skb* is uncloned,
2329 * which is a necessary condition for direct write. As this needs
2330 * to be an invariant for the write part only, the verifier
2331 * detects writes and adds a prologue that is calling
2332 * **bpf_skb_pull_data()** to effectively unclone the *skb* from
2333 * the very beginning in case it is indeed cloned.
2335 * A call to this helper is susceptible to change the underlying
2336 * packet buffer. Therefore, at load time, all checks on pointers
2337 * previously done by the verifier are invalidated and must be
2338 * performed again, if the helper is used in combination with
2339 * direct packet access.
2341 * 0 on success, or a negative error in case of failure.
2343 * s64 bpf_csum_update(struct sk_buff *skb, __wsum csum)
2345 * Add the checksum *csum* into *skb*\ **->csum** in case the
2346 * driver has supplied a checksum for the entire packet into that
2347 * field. Return an error otherwise. This helper is intended to be
2348 * used in combination with **bpf_csum_diff**\ (), in particular
2349 * when the checksum needs to be updated after data has been
2350 * written into the packet through direct packet access.
2352 * The checksum on success, or a negative error code in case of
2355 * void bpf_set_hash_invalid(struct sk_buff *skb)
2357 * Invalidate the current *skb*\ **->hash**. It can be used after
2358 * mangling on headers through direct packet access, in order to
2359 * indicate that the hash is outdated and to trigger a
2360 * recalculation the next time the kernel tries to access this
2361 * hash or when the **bpf_get_hash_recalc**\ () helper is called.
2363 * long bpf_get_numa_node_id(void)
2365 * Return the id of the current NUMA node. The primary use case
2366 * for this helper is the selection of sockets for the local NUMA
2367 * node, when the program is attached to sockets using the
2368 * **SO_ATTACH_REUSEPORT_EBPF** option (see also **socket(7)**),
2369 * but the helper is also available to other eBPF program types,
2370 * similarly to **bpf_get_smp_processor_id**\ ().
2372 * The id of current NUMA node.
2374 * long bpf_skb_change_head(struct sk_buff *skb, u32 len, u64 flags)
2376 * Grows headroom of packet associated to *skb* and adjusts the
2377 * offset of the MAC header accordingly, adding *len* bytes of
2378 * space. It automatically extends and reallocates memory as
2381 * This helper can be used on a layer 3 *skb* to push a MAC header
2382 * for redirection into a layer 2 device.
2384 * All values for *flags* are reserved for future usage, and must
2387 * A call to this helper is susceptible to change the underlying
2388 * packet buffer. Therefore, at load time, all checks on pointers
2389 * previously done by the verifier are invalidated and must be
2390 * performed again, if the helper is used in combination with
2391 * direct packet access.
2393 * 0 on success, or a negative error in case of failure.
2395 * long bpf_xdp_adjust_head(struct xdp_buff *xdp_md, int delta)
2397 * Adjust (move) *xdp_md*\ **->data** by *delta* bytes. Note that
2398 * it is possible to use a negative value for *delta*. This helper
2399 * can be used to prepare the packet for pushing or popping
2402 * A call to this helper is susceptible to change the underlying
2403 * packet buffer. Therefore, at load time, all checks on pointers
2404 * previously done by the verifier are invalidated and must be
2405 * performed again, if the helper is used in combination with
2406 * direct packet access.
2408 * 0 on success, or a negative error in case of failure.
2410 * long bpf_probe_read_str(void *dst, u32 size, const void *unsafe_ptr)
2412 * Copy a NUL terminated string from an unsafe kernel address
2413 * *unsafe_ptr* to *dst*. See **bpf_probe_read_kernel_str**\ () for
2416 * Generally, use **bpf_probe_read_user_str**\ () or
2417 * **bpf_probe_read_kernel_str**\ () instead.
2419 * On success, the strictly positive length of the string,
2420 * including the trailing NUL character. On error, a negative
2423 * u64 bpf_get_socket_cookie(struct sk_buff *skb)
2425 * If the **struct sk_buff** pointed by *skb* has a known socket,
2426 * retrieve the cookie (generated by the kernel) of this socket.
2427 * If no cookie has been set yet, generate a new cookie. Once
2428 * generated, the socket cookie remains stable for the life of the
2429 * socket. This helper can be useful for monitoring per socket
2430 * networking traffic statistics as it provides a global socket
2431 * identifier that can be assumed unique.
2433 * A 8-byte long unique number on success, or 0 if the socket
2434 * field is missing inside *skb*.
2436 * u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)
2438 * Equivalent to bpf_get_socket_cookie() helper that accepts
2439 * *skb*, but gets socket from **struct bpf_sock_addr** context.
2441 * A 8-byte long unique number.
2443 * u64 bpf_get_socket_cookie(struct bpf_sock_ops *ctx)
2445 * Equivalent to **bpf_get_socket_cookie**\ () helper that accepts
2446 * *skb*, but gets socket from **struct bpf_sock_ops** context.
2448 * A 8-byte long unique number.
2450 * u64 bpf_get_socket_cookie(struct sock *sk)
2452 * Equivalent to **bpf_get_socket_cookie**\ () helper that accepts
2453 * *sk*, but gets socket from a BTF **struct sock**. This helper
2454 * also works for sleepable programs.
2456 * A 8-byte long unique number or 0 if *sk* is NULL.
2458 * u32 bpf_get_socket_uid(struct sk_buff *skb)
2460 * The owner UID of the socket associated to *skb*. If the socket
2461 * is **NULL**, or if it is not a full socket (i.e. if it is a
2462 * time-wait or a request socket instead), **overflowuid** value
2463 * is returned (note that **overflowuid** might also be the actual
2464 * UID value for the socket).
2466 * long bpf_set_hash(struct sk_buff *skb, u32 hash)
2468 * Set the full hash for *skb* (set the field *skb*\ **->hash**)
2473 * long bpf_setsockopt(void *bpf_socket, int level, int optname, void *optval, int optlen)
2475 * Emulate a call to **setsockopt()** on the socket associated to
2476 * *bpf_socket*, which must be a full socket. The *level* at
2477 * which the option resides and the name *optname* of the option
2478 * must be specified, see **setsockopt(2)** for more information.
2479 * The option value of length *optlen* is pointed by *optval*.
2481 * *bpf_socket* should be one of the following:
2483 * * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**.
2484 * * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT**
2485 * and **BPF_CGROUP_INET6_CONNECT**.
2487 * This helper actually implements a subset of **setsockopt()**.
2488 * It supports the following *level*\ s:
2490 * * **SOL_SOCKET**, which supports the following *optname*\ s:
2491 * **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**,
2492 * **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**,
2493 * **SO_BINDTODEVICE**, **SO_KEEPALIVE**.
2494 * * **IPPROTO_TCP**, which supports the following *optname*\ s:
2495 * **TCP_CONGESTION**, **TCP_BPF_IW**,
2496 * **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**,
2497 * **TCP_KEEPIDLE**, **TCP_KEEPINTVL**, **TCP_KEEPCNT**,
2498 * **TCP_SYNCNT**, **TCP_USER_TIMEOUT**, **TCP_NOTSENT_LOWAT**.
2499 * * **IPPROTO_IP**, which supports *optname* **IP_TOS**.
2500 * * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.
2502 * 0 on success, or a negative error in case of failure.
2504 * long bpf_skb_adjust_room(struct sk_buff *skb, s32 len_diff, u32 mode, u64 flags)
2506 * Grow or shrink the room for data in the packet associated to
2507 * *skb* by *len_diff*, and according to the selected *mode*.
2509 * By default, the helper will reset any offloaded checksum
2510 * indicator of the skb to CHECKSUM_NONE. This can be avoided
2511 * by the following flag:
2513 * * **BPF_F_ADJ_ROOM_NO_CSUM_RESET**: Do not reset offloaded
2514 * checksum data of the skb to CHECKSUM_NONE.
2516 * There are two supported modes at this time:
2518 * * **BPF_ADJ_ROOM_MAC**: Adjust room at the mac layer
2519 * (room space is added or removed below the layer 2 header).
2521 * * **BPF_ADJ_ROOM_NET**: Adjust room at the network layer
2522 * (room space is added or removed below the layer 3 header).
2524 * The following flags are supported at this time:
2526 * * **BPF_F_ADJ_ROOM_FIXED_GSO**: Do not adjust gso_size.
2527 * Adjusting mss in this way is not allowed for datagrams.
2529 * * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV4**,
2530 * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV6**:
2531 * Any new space is reserved to hold a tunnel header.
2532 * Configure skb offsets and other fields accordingly.
2534 * * **BPF_F_ADJ_ROOM_ENCAP_L4_GRE**,
2535 * **BPF_F_ADJ_ROOM_ENCAP_L4_UDP**:
2536 * Use with ENCAP_L3 flags to further specify the tunnel type.
2538 * * **BPF_F_ADJ_ROOM_ENCAP_L2**\ (*len*):
2539 * Use with ENCAP_L3/L4 flags to further specify the tunnel
2540 * type; *len* is the length of the inner MAC header.
2542 * * **BPF_F_ADJ_ROOM_ENCAP_L2_ETH**:
2543 * Use with BPF_F_ADJ_ROOM_ENCAP_L2 flag to further specify the
2544 * L2 type as Ethernet.
2546 * A call to this helper is susceptible to change the underlying
2547 * packet buffer. Therefore, at load time, all checks on pointers
2548 * previously done by the verifier are invalidated and must be
2549 * performed again, if the helper is used in combination with
2550 * direct packet access.
2552 * 0 on success, or a negative error in case of failure.
2554 * long bpf_redirect_map(struct bpf_map *map, u32 key, u64 flags)
2556 * Redirect the packet to the endpoint referenced by *map* at
2557 * index *key*. Depending on its type, this *map* can contain
2558 * references to net devices (for forwarding packets through other
2559 * ports), or to CPUs (for redirecting XDP frames to another CPU;
2560 * but this is only implemented for native XDP (with driver
2561 * support) as of this writing).
2563 * The lower two bits of *flags* are used as the return code if
2564 * the map lookup fails. This is so that the return value can be
2565 * one of the XDP program return codes up to **XDP_TX**, as chosen
2566 * by the caller. The higher bits of *flags* can be set to
2567 * BPF_F_BROADCAST or BPF_F_EXCLUDE_INGRESS as defined below.
2569 * With BPF_F_BROADCAST the packet will be broadcasted to all the
2570 * interfaces in the map, with BPF_F_EXCLUDE_INGRESS the ingress
2571 * interface will be excluded when do broadcasting.
2573 * See also **bpf_redirect**\ (), which only supports redirecting
2574 * to an ifindex, but doesn't require a map to do so.
2576 * **XDP_REDIRECT** on success, or the value of the two lower bits
2577 * of the *flags* argument on error.
2579 * long bpf_sk_redirect_map(struct sk_buff *skb, struct bpf_map *map, u32 key, u64 flags)
2581 * Redirect the packet to the socket referenced by *map* (of type
2582 * **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
2583 * egress interfaces can be used for redirection. The
2584 * **BPF_F_INGRESS** value in *flags* is used to make the
2585 * distinction (ingress path is selected if the flag is present,
2586 * egress path otherwise). This is the only flag supported for now.
2588 * **SK_PASS** on success, or **SK_DROP** on error.
2590 * long bpf_sock_map_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags)
2592 * Add an entry to, or update a *map* referencing sockets. The
2593 * *skops* is used as a new value for the entry associated to
2594 * *key*. *flags* is one of:
2597 * The entry for *key* must not exist in the map.
2599 * The entry for *key* must already exist in the map.
2601 * No condition on the existence of the entry for *key*.
2603 * If the *map* has eBPF programs (parser and verdict), those will
2604 * be inherited by the socket being added. If the socket is
2605 * already attached to eBPF programs, this results in an error.
2607 * 0 on success, or a negative error in case of failure.
2609 * long bpf_xdp_adjust_meta(struct xdp_buff *xdp_md, int delta)
2611 * Adjust the address pointed by *xdp_md*\ **->data_meta** by
2612 * *delta* (which can be positive or negative). Note that this
2613 * operation modifies the address stored in *xdp_md*\ **->data**,
2614 * so the latter must be loaded only after the helper has been
2617 * The use of *xdp_md*\ **->data_meta** is optional and programs
2618 * are not required to use it. The rationale is that when the
2619 * packet is processed with XDP (e.g. as DoS filter), it is
2620 * possible to push further meta data along with it before passing
2621 * to the stack, and to give the guarantee that an ingress eBPF
2622 * program attached as a TC classifier on the same device can pick
2623 * this up for further post-processing. Since TC works with socket
2624 * buffers, it remains possible to set from XDP the **mark** or
2625 * **priority** pointers, or other pointers for the socket buffer.
2626 * Having this scratch space generic and programmable allows for
2627 * more flexibility as the user is free to store whatever meta
2630 * A call to this helper is susceptible to change the underlying
2631 * packet buffer. Therefore, at load time, all checks on pointers
2632 * previously done by the verifier are invalidated and must be
2633 * performed again, if the helper is used in combination with
2634 * direct packet access.
2636 * 0 on success, or a negative error in case of failure.
2638 * long bpf_perf_event_read_value(struct bpf_map *map, u64 flags, struct bpf_perf_event_value *buf, u32 buf_size)
2640 * Read the value of a perf event counter, and store it into *buf*
2641 * of size *buf_size*. This helper relies on a *map* of type
2642 * **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of the perf event
2643 * counter is selected when *map* is updated with perf event file
2644 * descriptors. The *map* is an array whose size is the number of
2645 * available CPUs, and each cell contains a value relative to one
2646 * CPU. The value to retrieve is indicated by *flags*, that
2647 * contains the index of the CPU to look up, masked with
2648 * **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
2649 * **BPF_F_CURRENT_CPU** to indicate that the value for the
2650 * current CPU should be retrieved.
2652 * This helper behaves in a way close to
2653 * **bpf_perf_event_read**\ () helper, save that instead of
2654 * just returning the value observed, it fills the *buf*
2655 * structure. This allows for additional data to be retrieved: in
2656 * particular, the enabled and running times (in *buf*\
2657 * **->enabled** and *buf*\ **->running**, respectively) are
2658 * copied. In general, **bpf_perf_event_read_value**\ () is
2659 * recommended over **bpf_perf_event_read**\ (), which has some
2660 * ABI issues and provides fewer functionalities.
2662 * These values are interesting, because hardware PMU (Performance
2663 * Monitoring Unit) counters are limited resources. When there are
2664 * more PMU based perf events opened than available counters,
2665 * kernel will multiplex these events so each event gets certain
2666 * percentage (but not all) of the PMU time. In case that
2667 * multiplexing happens, the number of samples or counter value
2668 * will not reflect the case compared to when no multiplexing
2669 * occurs. This makes comparison between different runs difficult.
2670 * Typically, the counter value should be normalized before
2671 * comparing to other experiments. The usual normalization is done
2676 * normalized_counter = counter * t_enabled / t_running
2678 * Where t_enabled is the time enabled for event and t_running is
2679 * the time running for event since last normalization. The
2680 * enabled and running times are accumulated since the perf event
2681 * open. To achieve scaling factor between two invocations of an
2682 * eBPF program, users can use CPU id as the key (which is
2683 * typical for perf array usage model) to remember the previous
2684 * value and do the calculation inside the eBPF program.
2686 * 0 on success, or a negative error in case of failure.
2688 * long bpf_perf_prog_read_value(struct bpf_perf_event_data *ctx, struct bpf_perf_event_value *buf, u32 buf_size)
2690 * For en eBPF program attached to a perf event, retrieve the
2691 * value of the event counter associated to *ctx* and store it in
2692 * the structure pointed by *buf* and of size *buf_size*. Enabled
2693 * and running times are also stored in the structure (see
2694 * description of helper **bpf_perf_event_read_value**\ () for
2697 * 0 on success, or a negative error in case of failure.
2699 * long bpf_getsockopt(void *bpf_socket, int level, int optname, void *optval, int optlen)
2701 * Emulate a call to **getsockopt()** on the socket associated to
2702 * *bpf_socket*, which must be a full socket. The *level* at
2703 * which the option resides and the name *optname* of the option
2704 * must be specified, see **getsockopt(2)** for more information.
2705 * The retrieved value is stored in the structure pointed by
2706 * *opval* and of length *optlen*.
2708 * *bpf_socket* should be one of the following:
2710 * * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**.
2711 * * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT**
2712 * and **BPF_CGROUP_INET6_CONNECT**.
2714 * This helper actually implements a subset of **getsockopt()**.
2715 * It supports the following *level*\ s:
2717 * * **IPPROTO_TCP**, which supports *optname*
2718 * **TCP_CONGESTION**.
2719 * * **IPPROTO_IP**, which supports *optname* **IP_TOS**.
2720 * * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.
2722 * 0 on success, or a negative error in case of failure.
2724 * long bpf_override_return(struct pt_regs *regs, u64 rc)
2726 * Used for error injection, this helper uses kprobes to override
2727 * the return value of the probed function, and to set it to *rc*.
2728 * The first argument is the context *regs* on which the kprobe
2731 * This helper works by setting the PC (program counter)
2732 * to an override function which is run in place of the original
2733 * probed function. This means the probed function is not run at
2734 * all. The replacement function just returns with the required
2737 * This helper has security implications, and thus is subject to
2738 * restrictions. It is only available if the kernel was compiled
2739 * with the **CONFIG_BPF_KPROBE_OVERRIDE** configuration
2740 * option, and in this case it only works on functions tagged with
2741 * **ALLOW_ERROR_INJECTION** in the kernel code.
2743 * Also, the helper is only available for the architectures having
2744 * the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing,
2745 * x86 architecture is the only one to support this feature.
2749 * long bpf_sock_ops_cb_flags_set(struct bpf_sock_ops *bpf_sock, int argval)
2751 * Attempt to set the value of the **bpf_sock_ops_cb_flags** field
2752 * for the full TCP socket associated to *bpf_sock_ops* to
2755 * The primary use of this field is to determine if there should
2756 * be calls to eBPF programs of type
2757 * **BPF_PROG_TYPE_SOCK_OPS** at various points in the TCP
2758 * code. A program of the same type can change its value, per
2759 * connection and as necessary, when the connection is
2760 * established. This field is directly accessible for reading, but
2761 * this helper must be used for updates in order to return an
2762 * error if an eBPF program tries to set a callback that is not
2763 * supported in the current kernel.
2765 * *argval* is a flag array which can combine these flags:
2767 * * **BPF_SOCK_OPS_RTO_CB_FLAG** (retransmission time out)
2768 * * **BPF_SOCK_OPS_RETRANS_CB_FLAG** (retransmission)
2769 * * **BPF_SOCK_OPS_STATE_CB_FLAG** (TCP state change)
2770 * * **BPF_SOCK_OPS_RTT_CB_FLAG** (every RTT)
2772 * Therefore, this function can be used to clear a callback flag by
2773 * setting the appropriate bit to zero. e.g. to disable the RTO
2776 * **bpf_sock_ops_cb_flags_set(bpf_sock,**
2777 * **bpf_sock->bpf_sock_ops_cb_flags & ~BPF_SOCK_OPS_RTO_CB_FLAG)**
2779 * Here are some examples of where one could call such eBPF
2783 * * When a packet is retransmitted.
2784 * * When the connection terminates.
2785 * * When a packet is sent.
2786 * * When a packet is received.
2788 * Code **-EINVAL** if the socket is not a full TCP socket;
2789 * otherwise, a positive number containing the bits that could not
2790 * be set is returned (which comes down to 0 if all bits were set
2793 * long bpf_msg_redirect_map(struct sk_msg_buff *msg, struct bpf_map *map, u32 key, u64 flags)
2795 * This helper is used in programs implementing policies at the
2796 * socket level. If the message *msg* is allowed to pass (i.e. if
2797 * the verdict eBPF program returns **SK_PASS**), redirect it to
2798 * the socket referenced by *map* (of type
2799 * **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
2800 * egress interfaces can be used for redirection. The
2801 * **BPF_F_INGRESS** value in *flags* is used to make the
2802 * distinction (ingress path is selected if the flag is present,
2803 * egress path otherwise). This is the only flag supported for now.
2805 * **SK_PASS** on success, or **SK_DROP** on error.
2807 * long bpf_msg_apply_bytes(struct sk_msg_buff *msg, u32 bytes)
2809 * For socket policies, apply the verdict of the eBPF program to
2810 * the next *bytes* (number of bytes) of message *msg*.
2812 * For example, this helper can be used in the following cases:
2814 * * A single **sendmsg**\ () or **sendfile**\ () system call
2815 * contains multiple logical messages that the eBPF program is
2816 * supposed to read and for which it should apply a verdict.
2817 * * An eBPF program only cares to read the first *bytes* of a
2818 * *msg*. If the message has a large payload, then setting up
2819 * and calling the eBPF program repeatedly for all bytes, even
2820 * though the verdict is already known, would create unnecessary
2823 * When called from within an eBPF program, the helper sets a
2824 * counter internal to the BPF infrastructure, that is used to
2825 * apply the last verdict to the next *bytes*. If *bytes* is
2826 * smaller than the current data being processed from a
2827 * **sendmsg**\ () or **sendfile**\ () system call, the first
2828 * *bytes* will be sent and the eBPF program will be re-run with
2829 * the pointer for start of data pointing to byte number *bytes*
2830 * **+ 1**. If *bytes* is larger than the current data being
2831 * processed, then the eBPF verdict will be applied to multiple
2832 * **sendmsg**\ () or **sendfile**\ () calls until *bytes* are
2835 * Note that if a socket closes with the internal counter holding
2836 * a non-zero value, this is not a problem because data is not
2837 * being buffered for *bytes* and is sent as it is received.
2841 * long bpf_msg_cork_bytes(struct sk_msg_buff *msg, u32 bytes)
2843 * For socket policies, prevent the execution of the verdict eBPF
2844 * program for message *msg* until *bytes* (byte number) have been
2847 * This can be used when one needs a specific number of bytes
2848 * before a verdict can be assigned, even if the data spans
2849 * multiple **sendmsg**\ () or **sendfile**\ () calls. The extreme
2850 * case would be a user calling **sendmsg**\ () repeatedly with
2851 * 1-byte long message segments. Obviously, this is bad for
2852 * performance, but it is still valid. If the eBPF program needs
2853 * *bytes* bytes to validate a header, this helper can be used to
2854 * prevent the eBPF program to be called again until *bytes* have
2859 * long bpf_msg_pull_data(struct sk_msg_buff *msg, u32 start, u32 end, u64 flags)
2861 * For socket policies, pull in non-linear data from user space
2862 * for *msg* and set pointers *msg*\ **->data** and *msg*\
2863 * **->data_end** to *start* and *end* bytes offsets into *msg*,
2866 * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
2867 * *msg* it can only parse data that the (**data**, **data_end**)
2868 * pointers have already consumed. For **sendmsg**\ () hooks this
2869 * is likely the first scatterlist element. But for calls relying
2870 * on the **sendpage** handler (e.g. **sendfile**\ ()) this will
2871 * be the range (**0**, **0**) because the data is shared with
2872 * user space and by default the objective is to avoid allowing
2873 * user space to modify data while (or after) eBPF verdict is
2874 * being decided. This helper can be used to pull in data and to
2875 * set the start and end pointer to given values. Data will be
2876 * copied if necessary (i.e. if data was not linear and if start
2877 * and end pointers do not point to the same chunk).
2879 * A call to this helper is susceptible to change the underlying
2880 * packet buffer. Therefore, at load time, all checks on pointers
2881 * previously done by the verifier are invalidated and must be
2882 * performed again, if the helper is used in combination with
2883 * direct packet access.
2885 * All values for *flags* are reserved for future usage, and must
2888 * 0 on success, or a negative error in case of failure.
2890 * long bpf_bind(struct bpf_sock_addr *ctx, struct sockaddr *addr, int addr_len)
2892 * Bind the socket associated to *ctx* to the address pointed by
2893 * *addr*, of length *addr_len*. This allows for making outgoing
2894 * connection from the desired IP address, which can be useful for
2895 * example when all processes inside a cgroup should use one
2896 * single IP address on a host that has multiple IP configured.
2898 * This helper works for IPv4 and IPv6, TCP and UDP sockets. The
2899 * domain (*addr*\ **->sa_family**) must be **AF_INET** (or
2900 * **AF_INET6**). It's advised to pass zero port (**sin_port**
2901 * or **sin6_port**) which triggers IP_BIND_ADDRESS_NO_PORT-like
2902 * behavior and lets the kernel efficiently pick up an unused
2903 * port as long as 4-tuple is unique. Passing non-zero port might
2904 * lead to degraded performance.
2906 * 0 on success, or a negative error in case of failure.
2908 * long bpf_xdp_adjust_tail(struct xdp_buff *xdp_md, int delta)
2910 * Adjust (move) *xdp_md*\ **->data_end** by *delta* bytes. It is
2911 * possible to both shrink and grow the packet tail.
2912 * Shrink done via *delta* being a negative integer.
2914 * A call to this helper is susceptible to change the underlying
2915 * packet buffer. Therefore, at load time, all checks on pointers
2916 * previously done by the verifier are invalidated and must be
2917 * performed again, if the helper is used in combination with
2918 * direct packet access.
2920 * 0 on success, or a negative error in case of failure.
2922 * long bpf_skb_get_xfrm_state(struct sk_buff *skb, u32 index, struct bpf_xfrm_state *xfrm_state, u32 size, u64 flags)
2924 * Retrieve the XFRM state (IP transform framework, see also
2925 * **ip-xfrm(8)**) at *index* in XFRM "security path" for *skb*.
2927 * The retrieved value is stored in the **struct bpf_xfrm_state**
2928 * pointed by *xfrm_state* and of length *size*.
2930 * All values for *flags* are reserved for future usage, and must
2933 * This helper is available only if the kernel was compiled with
2934 * **CONFIG_XFRM** configuration option.
2936 * 0 on success, or a negative error in case of failure.
2938 * long bpf_get_stack(void *ctx, void *buf, u32 size, u64 flags)
2940 * Return a user or a kernel stack in bpf program provided buffer.
2941 * To achieve this, the helper needs *ctx*, which is a pointer
2942 * to the context on which the tracing program is executed.
2943 * To store the stacktrace, the bpf program provides *buf* with
2944 * a nonnegative *size*.
2946 * The last argument, *flags*, holds the number of stack frames to
2947 * skip (from 0 to 255), masked with
2948 * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
2949 * the following flags:
2951 * **BPF_F_USER_STACK**
2952 * Collect a user space stack instead of a kernel stack.
2953 * **BPF_F_USER_BUILD_ID**
2954 * Collect buildid+offset instead of ips for user stack,
2955 * only valid if **BPF_F_USER_STACK** is also specified.
2957 * **bpf_get_stack**\ () can collect up to
2958 * **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject
2959 * to sufficient large buffer size. Note that
2960 * this limit can be controlled with the **sysctl** program, and
2961 * that it should be manually increased in order to profile long
2962 * user stacks (such as stacks for Java programs). To do so, use:
2966 * # sysctl kernel.perf_event_max_stack=<new value>
2968 * A non-negative value equal to or less than *size* on success,
2969 * or a negative error in case of failure.
2971 * long bpf_skb_load_bytes_relative(const void *skb, u32 offset, void *to, u32 len, u32 start_header)
2973 * This helper is similar to **bpf_skb_load_bytes**\ () in that
2974 * it provides an easy way to load *len* bytes from *offset*
2975 * from the packet associated to *skb*, into the buffer pointed
2976 * by *to*. The difference to **bpf_skb_load_bytes**\ () is that
2977 * a fifth argument *start_header* exists in order to select a
2978 * base offset to start from. *start_header* can be one of:
2980 * **BPF_HDR_START_MAC**
2981 * Base offset to load data from is *skb*'s mac header.
2982 * **BPF_HDR_START_NET**
2983 * Base offset to load data from is *skb*'s network header.
2985 * In general, "direct packet access" is the preferred method to
2986 * access packet data, however, this helper is in particular useful
2987 * in socket filters where *skb*\ **->data** does not always point
2988 * to the start of the mac header and where "direct packet access"
2991 * 0 on success, or a negative error in case of failure.
2993 * long bpf_fib_lookup(void *ctx, struct bpf_fib_lookup *params, int plen, u32 flags)
2995 * Do FIB lookup in kernel tables using parameters in *params*.
2996 * If lookup is successful and result shows packet is to be
2997 * forwarded, the neighbor tables are searched for the nexthop.
2998 * If successful (ie., FIB lookup shows forwarding and nexthop
2999 * is resolved), the nexthop address is returned in ipv4_dst
3000 * or ipv6_dst based on family, smac is set to mac address of
3001 * egress device, dmac is set to nexthop mac address, rt_metric
3002 * is set to metric from route (IPv4/IPv6 only), and ifindex
3003 * is set to the device index of the nexthop from the FIB lookup.
3005 * *plen* argument is the size of the passed in struct.
3006 * *flags* argument can be a combination of one or more of the
3009 * **BPF_FIB_LOOKUP_DIRECT**
3010 * Do a direct table lookup vs full lookup using FIB
3012 * **BPF_FIB_LOOKUP_OUTPUT**
3013 * Perform lookup from an egress perspective (default is
3016 * *ctx* is either **struct xdp_md** for XDP programs or
3017 * **struct sk_buff** tc cls_act programs.
3019 * * < 0 if any input argument is invalid
3020 * * 0 on success (packet is forwarded, nexthop neighbor exists)
3021 * * > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the
3022 * packet is not forwarded or needs assist from full stack
3024 * If lookup fails with BPF_FIB_LKUP_RET_FRAG_NEEDED, then the MTU
3025 * was exceeded and output params->mtu_result contains the MTU.
3027 * long bpf_sock_hash_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags)
3029 * Add an entry to, or update a sockhash *map* referencing sockets.
3030 * The *skops* is used as a new value for the entry associated to
3031 * *key*. *flags* is one of:
3034 * The entry for *key* must not exist in the map.
3036 * The entry for *key* must already exist in the map.
3038 * No condition on the existence of the entry for *key*.
3040 * If the *map* has eBPF programs (parser and verdict), those will
3041 * be inherited by the socket being added. If the socket is
3042 * already attached to eBPF programs, this results in an error.
3044 * 0 on success, or a negative error in case of failure.
3046 * long bpf_msg_redirect_hash(struct sk_msg_buff *msg, struct bpf_map *map, void *key, u64 flags)
3048 * This helper is used in programs implementing policies at the
3049 * socket level. If the message *msg* is allowed to pass (i.e. if
3050 * the verdict eBPF program returns **SK_PASS**), redirect it to
3051 * the socket referenced by *map* (of type
3052 * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
3053 * egress interfaces can be used for redirection. The
3054 * **BPF_F_INGRESS** value in *flags* is used to make the
3055 * distinction (ingress path is selected if the flag is present,
3056 * egress path otherwise). This is the only flag supported for now.
3058 * **SK_PASS** on success, or **SK_DROP** on error.
3060 * long bpf_sk_redirect_hash(struct sk_buff *skb, struct bpf_map *map, void *key, u64 flags)
3062 * This helper is used in programs implementing policies at the
3063 * skb socket level. If the sk_buff *skb* is allowed to pass (i.e.
3064 * if the verdict eBPF program returns **SK_PASS**), redirect it
3065 * to the socket referenced by *map* (of type
3066 * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
3067 * egress interfaces can be used for redirection. The
3068 * **BPF_F_INGRESS** value in *flags* is used to make the
3069 * distinction (ingress path is selected if the flag is present,
3070 * egress otherwise). This is the only flag supported for now.
3072 * **SK_PASS** on success, or **SK_DROP** on error.
3074 * long bpf_lwt_push_encap(struct sk_buff *skb, u32 type, void *hdr, u32 len)
3076 * Encapsulate the packet associated to *skb* within a Layer 3
3077 * protocol header. This header is provided in the buffer at
3078 * address *hdr*, with *len* its size in bytes. *type* indicates
3079 * the protocol of the header and can be one of:
3081 * **BPF_LWT_ENCAP_SEG6**
3082 * IPv6 encapsulation with Segment Routing Header
3083 * (**struct ipv6_sr_hdr**). *hdr* only contains the SRH,
3084 * the IPv6 header is computed by the kernel.
3085 * **BPF_LWT_ENCAP_SEG6_INLINE**
3086 * Only works if *skb* contains an IPv6 packet. Insert a
3087 * Segment Routing Header (**struct ipv6_sr_hdr**) inside
3089 * **BPF_LWT_ENCAP_IP**
3090 * IP encapsulation (GRE/GUE/IPIP/etc). The outer header
3091 * must be IPv4 or IPv6, followed by zero or more
3092 * additional headers, up to **LWT_BPF_MAX_HEADROOM**
3093 * total bytes in all prepended headers. Please note that
3094 * if **skb_is_gso**\ (*skb*) is true, no more than two
3095 * headers can be prepended, and the inner header, if
3096 * present, should be either GRE or UDP/GUE.
3098 * **BPF_LWT_ENCAP_SEG6**\ \* types can be called by BPF programs
3099 * of type **BPF_PROG_TYPE_LWT_IN**; **BPF_LWT_ENCAP_IP** type can
3100 * be called by bpf programs of types **BPF_PROG_TYPE_LWT_IN** and
3101 * **BPF_PROG_TYPE_LWT_XMIT**.
3103 * A call to this helper is susceptible to change the underlying
3104 * packet buffer. Therefore, at load time, all checks on pointers
3105 * previously done by the verifier are invalidated and must be
3106 * performed again, if the helper is used in combination with
3107 * direct packet access.
3109 * 0 on success, or a negative error in case of failure.
3111 * long bpf_lwt_seg6_store_bytes(struct sk_buff *skb, u32 offset, const void *from, u32 len)
3113 * Store *len* bytes from address *from* into the packet
3114 * associated to *skb*, at *offset*. Only the flags, tag and TLVs
3115 * inside the outermost IPv6 Segment Routing Header can be
3116 * modified through this helper.
3118 * A call to this helper is susceptible to change the underlying
3119 * packet buffer. Therefore, at load time, all checks on pointers
3120 * previously done by the verifier are invalidated and must be
3121 * performed again, if the helper is used in combination with
3122 * direct packet access.
3124 * 0 on success, or a negative error in case of failure.
3126 * long bpf_lwt_seg6_adjust_srh(struct sk_buff *skb, u32 offset, s32 delta)
3128 * Adjust the size allocated to TLVs in the outermost IPv6
3129 * Segment Routing Header contained in the packet associated to
3130 * *skb*, at position *offset* by *delta* bytes. Only offsets
3131 * after the segments are accepted. *delta* can be as well
3132 * positive (growing) as negative (shrinking).
3134 * A call to this helper is susceptible to change the underlying
3135 * packet buffer. Therefore, at load time, all checks on pointers
3136 * previously done by the verifier are invalidated and must be
3137 * performed again, if the helper is used in combination with
3138 * direct packet access.
3140 * 0 on success, or a negative error in case of failure.
3142 * long bpf_lwt_seg6_action(struct sk_buff *skb, u32 action, void *param, u32 param_len)
3144 * Apply an IPv6 Segment Routing action of type *action* to the
3145 * packet associated to *skb*. Each action takes a parameter
3146 * contained at address *param*, and of length *param_len* bytes.
3147 * *action* can be one of:
3149 * **SEG6_LOCAL_ACTION_END_X**
3150 * End.X action: Endpoint with Layer-3 cross-connect.
3151 * Type of *param*: **struct in6_addr**.
3152 * **SEG6_LOCAL_ACTION_END_T**
3153 * End.T action: Endpoint with specific IPv6 table lookup.
3154 * Type of *param*: **int**.
3155 * **SEG6_LOCAL_ACTION_END_B6**
3156 * End.B6 action: Endpoint bound to an SRv6 policy.
3157 * Type of *param*: **struct ipv6_sr_hdr**.
3158 * **SEG6_LOCAL_ACTION_END_B6_ENCAP**
3159 * End.B6.Encap action: Endpoint bound to an SRv6
3160 * encapsulation policy.
3161 * Type of *param*: **struct ipv6_sr_hdr**.
3163 * A call to this helper is susceptible to change the underlying
3164 * packet buffer. Therefore, at load time, all checks on pointers
3165 * previously done by the verifier are invalidated and must be
3166 * performed again, if the helper is used in combination with
3167 * direct packet access.
3169 * 0 on success, or a negative error in case of failure.
3171 * long bpf_rc_repeat(void *ctx)
3173 * This helper is used in programs implementing IR decoding, to
3174 * report a successfully decoded repeat key message. This delays
3175 * the generation of a key up event for previously generated
3178 * Some IR protocols like NEC have a special IR message for
3179 * repeating last button, for when a button is held down.
3181 * The *ctx* should point to the lirc sample as passed into
3184 * This helper is only available is the kernel was compiled with
3185 * the **CONFIG_BPF_LIRC_MODE2** configuration option set to
3190 * long bpf_rc_keydown(void *ctx, u32 protocol, u64 scancode, u32 toggle)
3192 * This helper is used in programs implementing IR decoding, to
3193 * report a successfully decoded key press with *scancode*,
3194 * *toggle* value in the given *protocol*. The scancode will be
3195 * translated to a keycode using the rc keymap, and reported as
3196 * an input key down event. After a period a key up event is
3197 * generated. This period can be extended by calling either
3198 * **bpf_rc_keydown**\ () again with the same values, or calling
3199 * **bpf_rc_repeat**\ ().
3201 * Some protocols include a toggle bit, in case the button was
3202 * released and pressed again between consecutive scancodes.
3204 * The *ctx* should point to the lirc sample as passed into
3207 * The *protocol* is the decoded protocol number (see
3208 * **enum rc_proto** for some predefined values).
3210 * This helper is only available is the kernel was compiled with
3211 * the **CONFIG_BPF_LIRC_MODE2** configuration option set to
3216 * u64 bpf_skb_cgroup_id(struct sk_buff *skb)
3218 * Return the cgroup v2 id of the socket associated with the *skb*.
3219 * This is roughly similar to the **bpf_get_cgroup_classid**\ ()
3220 * helper for cgroup v1 by providing a tag resp. identifier that
3221 * can be matched on or used for map lookups e.g. to implement
3222 * policy. The cgroup v2 id of a given path in the hierarchy is
3223 * exposed in user space through the f_handle API in order to get
3224 * to the same 64-bit id.
3226 * This helper can be used on TC egress path, but not on ingress,
3227 * and is available only if the kernel was compiled with the
3228 * **CONFIG_SOCK_CGROUP_DATA** configuration option.
3230 * The id is returned or 0 in case the id could not be retrieved.
3232 * u64 bpf_get_current_cgroup_id(void)
3234 * A 64-bit integer containing the current cgroup id based
3235 * on the cgroup within which the current task is running.
3237 * void *bpf_get_local_storage(void *map, u64 flags)
3239 * Get the pointer to the local storage area.
3240 * The type and the size of the local storage is defined
3241 * by the *map* argument.
3242 * The *flags* meaning is specific for each map type,
3243 * and has to be 0 for cgroup local storage.
3245 * Depending on the BPF program type, a local storage area
3246 * can be shared between multiple instances of the BPF program,
3247 * running simultaneously.
3249 * A user should care about the synchronization by himself.
3250 * For example, by using the **BPF_ATOMIC** instructions to alter
3253 * A pointer to the local storage area.
3255 * long bpf_sk_select_reuseport(struct sk_reuseport_md *reuse, struct bpf_map *map, void *key, u64 flags)
3257 * Select a **SO_REUSEPORT** socket from a
3258 * **BPF_MAP_TYPE_REUSEPORT_SOCKARRAY** *map*.
3259 * It checks the selected socket is matching the incoming
3260 * request in the socket buffer.
3262 * 0 on success, or a negative error in case of failure.
3264 * u64 bpf_skb_ancestor_cgroup_id(struct sk_buff *skb, int ancestor_level)
3266 * Return id of cgroup v2 that is ancestor of cgroup associated
3267 * with the *skb* at the *ancestor_level*. The root cgroup is at
3268 * *ancestor_level* zero and each step down the hierarchy
3269 * increments the level. If *ancestor_level* == level of cgroup
3270 * associated with *skb*, then return value will be same as that
3271 * of **bpf_skb_cgroup_id**\ ().
3273 * The helper is useful to implement policies based on cgroups
3274 * that are upper in hierarchy than immediate cgroup associated
3277 * The format of returned id and helper limitations are same as in
3278 * **bpf_skb_cgroup_id**\ ().
3280 * The id is returned or 0 in case the id could not be retrieved.
3282 * struct bpf_sock *bpf_sk_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
3284 * Look for TCP socket matching *tuple*, optionally in a child
3285 * network namespace *netns*. The return value must be checked,
3286 * and if non-**NULL**, released via **bpf_sk_release**\ ().
3288 * The *ctx* should point to the context of the program, such as
3289 * the skb or socket (depending on the hook in use). This is used
3290 * to determine the base network namespace for the lookup.
3292 * *tuple_size* must be one of:
3294 * **sizeof**\ (*tuple*\ **->ipv4**)
3295 * Look for an IPv4 socket.
3296 * **sizeof**\ (*tuple*\ **->ipv6**)
3297 * Look for an IPv6 socket.
3299 * If the *netns* is a negative signed 32-bit integer, then the
3300 * socket lookup table in the netns associated with the *ctx*
3301 * will be used. For the TC hooks, this is the netns of the device
3302 * in the skb. For socket hooks, this is the netns of the socket.
3303 * If *netns* is any other signed 32-bit value greater than or
3304 * equal to zero then it specifies the ID of the netns relative to
3305 * the netns associated with the *ctx*. *netns* values beyond the
3306 * range of 32-bit integers are reserved for future use.
3308 * All values for *flags* are reserved for future usage, and must
3311 * This helper is available only if the kernel was compiled with
3312 * **CONFIG_NET** configuration option.
3314 * Pointer to **struct bpf_sock**, or **NULL** in case of failure.
3315 * For sockets with reuseport option, the **struct bpf_sock**
3316 * result is from *reuse*\ **->socks**\ [] using the hash of the
3319 * struct bpf_sock *bpf_sk_lookup_udp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
3321 * Look for UDP socket matching *tuple*, optionally in a child
3322 * network namespace *netns*. The return value must be checked,
3323 * and if non-**NULL**, released via **bpf_sk_release**\ ().
3325 * The *ctx* should point to the context of the program, such as
3326 * the skb or socket (depending on the hook in use). This is used
3327 * to determine the base network namespace for the lookup.
3329 * *tuple_size* must be one of:
3331 * **sizeof**\ (*tuple*\ **->ipv4**)
3332 * Look for an IPv4 socket.
3333 * **sizeof**\ (*tuple*\ **->ipv6**)
3334 * Look for an IPv6 socket.
3336 * If the *netns* is a negative signed 32-bit integer, then the
3337 * socket lookup table in the netns associated with the *ctx*
3338 * will be used. For the TC hooks, this is the netns of the device
3339 * in the skb. For socket hooks, this is the netns of the socket.
3340 * If *netns* is any other signed 32-bit value greater than or
3341 * equal to zero then it specifies the ID of the netns relative to
3342 * the netns associated with the *ctx*. *netns* values beyond the
3343 * range of 32-bit integers are reserved for future use.
3345 * All values for *flags* are reserved for future usage, and must
3348 * This helper is available only if the kernel was compiled with
3349 * **CONFIG_NET** configuration option.
3351 * Pointer to **struct bpf_sock**, or **NULL** in case of failure.
3352 * For sockets with reuseport option, the **struct bpf_sock**
3353 * result is from *reuse*\ **->socks**\ [] using the hash of the
3356 * long bpf_sk_release(void *sock)
3358 * Release the reference held by *sock*. *sock* must be a
3359 * non-**NULL** pointer that was returned from
3360 * **bpf_sk_lookup_xxx**\ ().
3362 * 0 on success, or a negative error in case of failure.
3364 * long bpf_map_push_elem(struct bpf_map *map, const void *value, u64 flags)
3366 * Push an element *value* in *map*. *flags* is one of:
3369 * If the queue/stack is full, the oldest element is
3370 * removed to make room for this.
3372 * 0 on success, or a negative error in case of failure.
3374 * long bpf_map_pop_elem(struct bpf_map *map, void *value)
3376 * Pop an element from *map*.
3378 * 0 on success, or a negative error in case of failure.
3380 * long bpf_map_peek_elem(struct bpf_map *map, void *value)
3382 * Get an element from *map* without removing it.
3384 * 0 on success, or a negative error in case of failure.
3386 * long bpf_msg_push_data(struct sk_msg_buff *msg, u32 start, u32 len, u64 flags)
3388 * For socket policies, insert *len* bytes into *msg* at offset
3391 * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
3392 * *msg* it may want to insert metadata or options into the *msg*.
3393 * This can later be read and used by any of the lower layer BPF
3396 * This helper may fail if under memory pressure (a malloc
3397 * fails) in these cases BPF programs will get an appropriate
3398 * error and BPF programs will need to handle them.
3400 * 0 on success, or a negative error in case of failure.
3402 * long bpf_msg_pop_data(struct sk_msg_buff *msg, u32 start, u32 len, u64 flags)
3404 * Will remove *len* bytes from a *msg* starting at byte *start*.
3405 * This may result in **ENOMEM** errors under certain situations if
3406 * an allocation and copy are required due to a full ring buffer.
3407 * However, the helper will try to avoid doing the allocation
3408 * if possible. Other errors can occur if input parameters are
3409 * invalid either due to *start* byte not being valid part of *msg*
3410 * payload and/or *pop* value being to large.
3412 * 0 on success, or a negative error in case of failure.
3414 * long bpf_rc_pointer_rel(void *ctx, s32 rel_x, s32 rel_y)
3416 * This helper is used in programs implementing IR decoding, to
3417 * report a successfully decoded pointer movement.
3419 * The *ctx* should point to the lirc sample as passed into
3422 * This helper is only available is the kernel was compiled with
3423 * the **CONFIG_BPF_LIRC_MODE2** configuration option set to
3428 * long bpf_spin_lock(struct bpf_spin_lock *lock)
3430 * Acquire a spinlock represented by the pointer *lock*, which is
3431 * stored as part of a value of a map. Taking the lock allows to
3432 * safely update the rest of the fields in that value. The
3433 * spinlock can (and must) later be released with a call to
3434 * **bpf_spin_unlock**\ (\ *lock*\ ).
3436 * Spinlocks in BPF programs come with a number of restrictions
3439 * * **bpf_spin_lock** objects are only allowed inside maps of
3440 * types **BPF_MAP_TYPE_HASH** and **BPF_MAP_TYPE_ARRAY** (this
3441 * list could be extended in the future).
3442 * * BTF description of the map is mandatory.
3443 * * The BPF program can take ONE lock at a time, since taking two
3444 * or more could cause dead locks.
3445 * * Only one **struct bpf_spin_lock** is allowed per map element.
3446 * * When the lock is taken, calls (either BPF to BPF or helpers)
3448 * * The **BPF_LD_ABS** and **BPF_LD_IND** instructions are not
3449 * allowed inside a spinlock-ed region.
3450 * * The BPF program MUST call **bpf_spin_unlock**\ () to release
3451 * the lock, on all execution paths, before it returns.
3452 * * The BPF program can access **struct bpf_spin_lock** only via
3453 * the **bpf_spin_lock**\ () and **bpf_spin_unlock**\ ()
3454 * helpers. Loading or storing data into the **struct
3455 * bpf_spin_lock** *lock*\ **;** field of a map is not allowed.
3456 * * To use the **bpf_spin_lock**\ () helper, the BTF description
3457 * of the map value must be a struct and have **struct
3458 * bpf_spin_lock** *anyname*\ **;** field at the top level.
3459 * Nested lock inside another struct is not allowed.
3460 * * The **struct bpf_spin_lock** *lock* field in a map value must
3461 * be aligned on a multiple of 4 bytes in that value.
3462 * * Syscall with command **BPF_MAP_LOOKUP_ELEM** does not copy
3463 * the **bpf_spin_lock** field to user space.
3464 * * Syscall with command **BPF_MAP_UPDATE_ELEM**, or update from
3465 * a BPF program, do not update the **bpf_spin_lock** field.
3466 * * **bpf_spin_lock** cannot be on the stack or inside a
3467 * networking packet (it can only be inside of a map values).
3468 * * **bpf_spin_lock** is available to root only.
3469 * * Tracing programs and socket filter programs cannot use
3470 * **bpf_spin_lock**\ () due to insufficient preemption checks
3471 * (but this may change in the future).
3472 * * **bpf_spin_lock** is not allowed in inner maps of map-in-map.
3476 * long bpf_spin_unlock(struct bpf_spin_lock *lock)
3478 * Release the *lock* previously locked by a call to
3479 * **bpf_spin_lock**\ (\ *lock*\ ).
3483 * struct bpf_sock *bpf_sk_fullsock(struct bpf_sock *sk)
3485 * This helper gets a **struct bpf_sock** pointer such
3486 * that all the fields in this **bpf_sock** can be accessed.
3488 * A **struct bpf_sock** pointer on success, or **NULL** in
3491 * struct bpf_tcp_sock *bpf_tcp_sock(struct bpf_sock *sk)
3493 * This helper gets a **struct bpf_tcp_sock** pointer from a
3494 * **struct bpf_sock** pointer.
3496 * A **struct bpf_tcp_sock** pointer on success, or **NULL** in
3499 * long bpf_skb_ecn_set_ce(struct sk_buff *skb)
3501 * Set ECN (Explicit Congestion Notification) field of IP header
3502 * to **CE** (Congestion Encountered) if current value is **ECT**
3503 * (ECN Capable Transport). Otherwise, do nothing. Works with IPv6
3506 * 1 if the **CE** flag is set (either by the current helper call
3507 * or because it was already present), 0 if it is not set.
3509 * struct bpf_sock *bpf_get_listener_sock(struct bpf_sock *sk)
3511 * Return a **struct bpf_sock** pointer in **TCP_LISTEN** state.
3512 * **bpf_sk_release**\ () is unnecessary and not allowed.
3514 * A **struct bpf_sock** pointer on success, or **NULL** in
3517 * struct bpf_sock *bpf_skc_lookup_tcp(void *ctx, struct bpf_sock_tuple *tuple, u32 tuple_size, u64 netns, u64 flags)
3519 * Look for TCP socket matching *tuple*, optionally in a child
3520 * network namespace *netns*. The return value must be checked,
3521 * and if non-**NULL**, released via **bpf_sk_release**\ ().
3523 * This function is identical to **bpf_sk_lookup_tcp**\ (), except
3524 * that it also returns timewait or request sockets. Use
3525 * **bpf_sk_fullsock**\ () or **bpf_tcp_sock**\ () to access the
3528 * This helper is available only if the kernel was compiled with
3529 * **CONFIG_NET** configuration option.
3531 * Pointer to **struct bpf_sock**, or **NULL** in case of failure.
3532 * For sockets with reuseport option, the **struct bpf_sock**
3533 * result is from *reuse*\ **->socks**\ [] using the hash of the
3536 * long bpf_tcp_check_syncookie(void *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)
3538 * Check whether *iph* and *th* contain a valid SYN cookie ACK for
3539 * the listening socket in *sk*.
3541 * *iph* points to the start of the IPv4 or IPv6 header, while
3542 * *iph_len* contains **sizeof**\ (**struct iphdr**) or
3543 * **sizeof**\ (**struct ip6hdr**).
3545 * *th* points to the start of the TCP header, while *th_len*
3546 * contains **sizeof**\ (**struct tcphdr**).
3548 * 0 if *iph* and *th* are a valid SYN cookie ACK, or a negative
3551 * long bpf_sysctl_get_name(struct bpf_sysctl *ctx, char *buf, size_t buf_len, u64 flags)
3553 * Get name of sysctl in /proc/sys/ and copy it into provided by
3554 * program buffer *buf* of size *buf_len*.
3556 * The buffer is always NUL terminated, unless it's zero-sized.
3558 * If *flags* is zero, full name (e.g. "net/ipv4/tcp_mem") is
3559 * copied. Use **BPF_F_SYSCTL_BASE_NAME** flag to copy base name
3560 * only (e.g. "tcp_mem").
3562 * Number of character copied (not including the trailing NUL).
3564 * **-E2BIG** if the buffer wasn't big enough (*buf* will contain
3565 * truncated name in this case).
3567 * long bpf_sysctl_get_current_value(struct bpf_sysctl *ctx, char *buf, size_t buf_len)
3569 * Get current value of sysctl as it is presented in /proc/sys
3570 * (incl. newline, etc), and copy it as a string into provided
3571 * by program buffer *buf* of size *buf_len*.
3573 * The whole value is copied, no matter what file position user
3574 * space issued e.g. sys_read at.
3576 * The buffer is always NUL terminated, unless it's zero-sized.
3578 * Number of character copied (not including the trailing NUL).
3580 * **-E2BIG** if the buffer wasn't big enough (*buf* will contain
3581 * truncated name in this case).
3583 * **-EINVAL** if current value was unavailable, e.g. because
3584 * sysctl is uninitialized and read returns -EIO for it.
3586 * long bpf_sysctl_get_new_value(struct bpf_sysctl *ctx, char *buf, size_t buf_len)
3588 * Get new value being written by user space to sysctl (before
3589 * the actual write happens) and copy it as a string into
3590 * provided by program buffer *buf* of size *buf_len*.
3592 * User space may write new value at file position > 0.
3594 * The buffer is always NUL terminated, unless it's zero-sized.
3596 * Number of character copied (not including the trailing NUL).
3598 * **-E2BIG** if the buffer wasn't big enough (*buf* will contain
3599 * truncated name in this case).
3601 * **-EINVAL** if sysctl is being read.
3603 * long bpf_sysctl_set_new_value(struct bpf_sysctl *ctx, const char *buf, size_t buf_len)
3605 * Override new value being written by user space to sysctl with
3606 * value provided by program in buffer *buf* of size *buf_len*.
3608 * *buf* should contain a string in same form as provided by user
3609 * space on sysctl write.
3611 * User space may write new value at file position > 0. To override
3612 * the whole sysctl value file position should be set to zero.
3616 * **-E2BIG** if the *buf_len* is too big.
3618 * **-EINVAL** if sysctl is being read.
3620 * long bpf_strtol(const char *buf, size_t buf_len, u64 flags, long *res)
3622 * Convert the initial part of the string from buffer *buf* of
3623 * size *buf_len* to a long integer according to the given base
3624 * and save the result in *res*.
3626 * The string may begin with an arbitrary amount of white space
3627 * (as determined by **isspace**\ (3)) followed by a single
3628 * optional '**-**' sign.
3630 * Five least significant bits of *flags* encode base, other bits
3631 * are currently unused.
3633 * Base must be either 8, 10, 16 or 0 to detect it automatically
3634 * similar to user space **strtol**\ (3).
3636 * Number of characters consumed on success. Must be positive but
3637 * no more than *buf_len*.
3639 * **-EINVAL** if no valid digits were found or unsupported base
3642 * **-ERANGE** if resulting value was out of range.
3644 * long bpf_strtoul(const char *buf, size_t buf_len, u64 flags, unsigned long *res)
3646 * Convert the initial part of the string from buffer *buf* of
3647 * size *buf_len* to an unsigned long integer according to the
3648 * given base and save the result in *res*.
3650 * The string may begin with an arbitrary amount of white space
3651 * (as determined by **isspace**\ (3)).
3653 * Five least significant bits of *flags* encode base, other bits
3654 * are currently unused.
3656 * Base must be either 8, 10, 16 or 0 to detect it automatically
3657 * similar to user space **strtoul**\ (3).
3659 * Number of characters consumed on success. Must be positive but
3660 * no more than *buf_len*.
3662 * **-EINVAL** if no valid digits were found or unsupported base
3665 * **-ERANGE** if resulting value was out of range.
3667 * void *bpf_sk_storage_get(struct bpf_map *map, void *sk, void *value, u64 flags)
3669 * Get a bpf-local-storage from a *sk*.
3671 * Logically, it could be thought of getting the value from
3672 * a *map* with *sk* as the **key**. From this
3673 * perspective, the usage is not much different from
3674 * **bpf_map_lookup_elem**\ (*map*, **&**\ *sk*) except this
3675 * helper enforces the key must be a full socket and the map must
3676 * be a **BPF_MAP_TYPE_SK_STORAGE** also.
3678 * Underneath, the value is stored locally at *sk* instead of
3679 * the *map*. The *map* is used as the bpf-local-storage
3680 * "type". The bpf-local-storage "type" (i.e. the *map*) is
3681 * searched against all bpf-local-storages residing at *sk*.
3683 * *sk* is a kernel **struct sock** pointer for LSM program.
3684 * *sk* is a **struct bpf_sock** pointer for other program types.
3686 * An optional *flags* (**BPF_SK_STORAGE_GET_F_CREATE**) can be
3687 * used such that a new bpf-local-storage will be
3688 * created if one does not exist. *value* can be used
3689 * together with **BPF_SK_STORAGE_GET_F_CREATE** to specify
3690 * the initial value of a bpf-local-storage. If *value* is
3691 * **NULL**, the new bpf-local-storage will be zero initialized.
3693 * A bpf-local-storage pointer is returned on success.
3695 * **NULL** if not found or there was an error in adding
3696 * a new bpf-local-storage.
3698 * long bpf_sk_storage_delete(struct bpf_map *map, void *sk)
3700 * Delete a bpf-local-storage from a *sk*.
3704 * **-ENOENT** if the bpf-local-storage cannot be found.
3705 * **-EINVAL** if sk is not a fullsock (e.g. a request_sock).
3707 * long bpf_send_signal(u32 sig)
3709 * Send signal *sig* to the process of the current task.
3710 * The signal may be delivered to any of this process's threads.
3712 * 0 on success or successfully queued.
3714 * **-EBUSY** if work queue under nmi is full.
3716 * **-EINVAL** if *sig* is invalid.
3718 * **-EPERM** if no permission to send the *sig*.
3720 * **-EAGAIN** if bpf program can try again.
3722 * s64 bpf_tcp_gen_syncookie(void *sk, void *iph, u32 iph_len, struct tcphdr *th, u32 th_len)
3724 * Try to issue a SYN cookie for the packet with corresponding
3725 * IP/TCP headers, *iph* and *th*, on the listening socket in *sk*.
3727 * *iph* points to the start of the IPv4 or IPv6 header, while
3728 * *iph_len* contains **sizeof**\ (**struct iphdr**) or
3729 * **sizeof**\ (**struct ip6hdr**).
3731 * *th* points to the start of the TCP header, while *th_len*
3732 * contains the length of the TCP header.
3734 * On success, lower 32 bits hold the generated SYN cookie in
3735 * followed by 16 bits which hold the MSS value for that cookie,
3736 * and the top 16 bits are unused.
3738 * On failure, the returned value is one of the following:
3740 * **-EINVAL** SYN cookie cannot be issued due to error
3742 * **-ENOENT** SYN cookie should not be issued (no SYN flood)
3744 * **-EOPNOTSUPP** kernel configuration does not enable SYN cookies
3746 * **-EPROTONOSUPPORT** IP packet version is not 4 or 6
3748 * long bpf_skb_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
3750 * Write raw *data* blob into a special BPF perf event held by
3751 * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
3752 * event must have the following attributes: **PERF_SAMPLE_RAW**
3753 * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
3754 * **PERF_COUNT_SW_BPF_OUTPUT** as **config**.
3756 * The *flags* are used to indicate the index in *map* for which
3757 * the value must be put, masked with **BPF_F_INDEX_MASK**.
3758 * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
3759 * to indicate that the index of the current CPU core should be
3762 * The value to write, of *size*, is passed through eBPF stack and
3763 * pointed by *data*.
3765 * *ctx* is a pointer to in-kernel struct sk_buff.
3767 * This helper is similar to **bpf_perf_event_output**\ () but
3768 * restricted to raw_tracepoint bpf programs.
3770 * 0 on success, or a negative error in case of failure.
3772 * long bpf_probe_read_user(void *dst, u32 size, const void *unsafe_ptr)
3774 * Safely attempt to read *size* bytes from user space address
3775 * *unsafe_ptr* and store the data in *dst*.
3777 * 0 on success, or a negative error in case of failure.
3779 * long bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
3781 * Safely attempt to read *size* bytes from kernel space address
3782 * *unsafe_ptr* and store the data in *dst*.
3784 * 0 on success, or a negative error in case of failure.
3786 * long bpf_probe_read_user_str(void *dst, u32 size, const void *unsafe_ptr)
3788 * Copy a NUL terminated string from an unsafe user address
3789 * *unsafe_ptr* to *dst*. The *size* should include the
3790 * terminating NUL byte. In case the string length is smaller than
3791 * *size*, the target is not padded with further NUL bytes. If the
3792 * string length is larger than *size*, just *size*-1 bytes are
3793 * copied and the last byte is set to NUL.
3795 * On success, returns the number of bytes that were written,
3796 * including the terminal NUL. This makes this helper useful in
3797 * tracing programs for reading strings, and more importantly to
3798 * get its length at runtime. See the following snippet:
3802 * SEC("kprobe/sys_open")
3803 * void bpf_sys_open(struct pt_regs *ctx)
3805 * char buf[PATHLEN]; // PATHLEN is defined to 256
3806 * int res = bpf_probe_read_user_str(buf, sizeof(buf),
3809 * // Consume buf, for example push it to
3810 * // userspace via bpf_perf_event_output(); we
3811 * // can use res (the string length) as event
3812 * // size, after checking its boundaries.
3815 * In comparison, using **bpf_probe_read_user**\ () helper here
3816 * instead to read the string would require to estimate the length
3817 * at compile time, and would often result in copying more memory
3820 * Another useful use case is when parsing individual process
3821 * arguments or individual environment variables navigating
3822 * *current*\ **->mm->arg_start** and *current*\
3823 * **->mm->env_start**: using this helper and the return value,
3824 * one can quickly iterate at the right offset of the memory area.
3826 * On success, the strictly positive length of the output string,
3827 * including the trailing NUL character. On error, a negative
3830 * long bpf_probe_read_kernel_str(void *dst, u32 size, const void *unsafe_ptr)
3832 * Copy a NUL terminated string from an unsafe kernel address *unsafe_ptr*
3833 * to *dst*. Same semantics as with **bpf_probe_read_user_str**\ () apply.
3835 * On success, the strictly positive length of the string, including
3836 * the trailing NUL character. On error, a negative value.
3838 * long bpf_tcp_send_ack(void *tp, u32 rcv_nxt)
3840 * Send out a tcp-ack. *tp* is the in-kernel struct **tcp_sock**.
3841 * *rcv_nxt* is the ack_seq to be sent out.
3843 * 0 on success, or a negative error in case of failure.
3845 * long bpf_send_signal_thread(u32 sig)
3847 * Send signal *sig* to the thread corresponding to the current task.
3849 * 0 on success or successfully queued.
3851 * **-EBUSY** if work queue under nmi is full.
3853 * **-EINVAL** if *sig* is invalid.
3855 * **-EPERM** if no permission to send the *sig*.
3857 * **-EAGAIN** if bpf program can try again.
3859 * u64 bpf_jiffies64(void)
3861 * Obtain the 64bit jiffies
3863 * The 64 bit jiffies
3865 * long bpf_read_branch_records(struct bpf_perf_event_data *ctx, void *buf, u32 size, u64 flags)
3867 * For an eBPF program attached to a perf event, retrieve the
3868 * branch records (**struct perf_branch_entry**) associated to *ctx*
3869 * and store it in the buffer pointed by *buf* up to size
3872 * On success, number of bytes written to *buf*. On error, a
3875 * The *flags* can be set to **BPF_F_GET_BRANCH_RECORDS_SIZE** to
3876 * instead return the number of bytes required to store all the
3877 * branch entries. If this flag is set, *buf* may be NULL.
3879 * **-EINVAL** if arguments invalid or **size** not a multiple
3880 * of **sizeof**\ (**struct perf_branch_entry**\ ).
3882 * **-ENOENT** if architecture does not support branch records.
3884 * long bpf_get_ns_current_pid_tgid(u64 dev, u64 ino, struct bpf_pidns_info *nsdata, u32 size)
3886 * Returns 0 on success, values for *pid* and *tgid* as seen from the current
3887 * *namespace* will be returned in *nsdata*.
3889 * 0 on success, or one of the following in case of failure:
3891 * **-EINVAL** if dev and inum supplied don't match dev_t and inode number
3892 * with nsfs of current task, or if dev conversion to dev_t lost high bits.
3894 * **-ENOENT** if pidns does not exists for the current task.
3896 * long bpf_xdp_output(void *ctx, struct bpf_map *map, u64 flags, void *data, u64 size)
3898 * Write raw *data* blob into a special BPF perf event held by
3899 * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
3900 * event must have the following attributes: **PERF_SAMPLE_RAW**
3901 * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
3902 * **PERF_COUNT_SW_BPF_OUTPUT** as **config**.
3904 * The *flags* are used to indicate the index in *map* for which
3905 * the value must be put, masked with **BPF_F_INDEX_MASK**.
3906 * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
3907 * to indicate that the index of the current CPU core should be
3910 * The value to write, of *size*, is passed through eBPF stack and
3911 * pointed by *data*.
3913 * *ctx* is a pointer to in-kernel struct xdp_buff.
3915 * This helper is similar to **bpf_perf_eventoutput**\ () but
3916 * restricted to raw_tracepoint bpf programs.
3918 * 0 on success, or a negative error in case of failure.
3920 * u64 bpf_get_netns_cookie(void *ctx)
3922 * Retrieve the cookie (generated by the kernel) of the network
3923 * namespace the input *ctx* is associated with. The network
3924 * namespace cookie remains stable for its lifetime and provides
3925 * a global identifier that can be assumed unique. If *ctx* is
3926 * NULL, then the helper returns the cookie for the initial
3927 * network namespace. The cookie itself is very similar to that
3928 * of **bpf_get_socket_cookie**\ () helper, but for network
3929 * namespaces instead of sockets.
3931 * A 8-byte long opaque number.
3933 * u64 bpf_get_current_ancestor_cgroup_id(int ancestor_level)
3935 * Return id of cgroup v2 that is ancestor of the cgroup associated
3936 * with the current task at the *ancestor_level*. The root cgroup
3937 * is at *ancestor_level* zero and each step down the hierarchy
3938 * increments the level. If *ancestor_level* == level of cgroup
3939 * associated with the current task, then return value will be the
3940 * same as that of **bpf_get_current_cgroup_id**\ ().
3942 * The helper is useful to implement policies based on cgroups
3943 * that are upper in hierarchy than immediate cgroup associated
3944 * with the current task.
3946 * The format of returned id and helper limitations are same as in
3947 * **bpf_get_current_cgroup_id**\ ().
3949 * The id is returned or 0 in case the id could not be retrieved.
3951 * long bpf_sk_assign(struct sk_buff *skb, void *sk, u64 flags)
3953 * Helper is overloaded depending on BPF program type. This
3954 * description applies to **BPF_PROG_TYPE_SCHED_CLS** and
3955 * **BPF_PROG_TYPE_SCHED_ACT** programs.
3957 * Assign the *sk* to the *skb*. When combined with appropriate
3958 * routing configuration to receive the packet towards the socket,
3959 * will cause *skb* to be delivered to the specified socket.
3960 * Subsequent redirection of *skb* via **bpf_redirect**\ (),
3961 * **bpf_clone_redirect**\ () or other methods outside of BPF may
3962 * interfere with successful delivery to the socket.
3964 * This operation is only valid from TC ingress path.
3966 * The *flags* argument must be zero.
3968 * 0 on success, or a negative error in case of failure:
3970 * **-EINVAL** if specified *flags* are not supported.
3972 * **-ENOENT** if the socket is unavailable for assignment.
3974 * **-ENETUNREACH** if the socket is unreachable (wrong netns).
3976 * **-EOPNOTSUPP** if the operation is not supported, for example
3977 * a call from outside of TC ingress.
3979 * **-ESOCKTNOSUPPORT** if the socket type is not supported
3982 * long bpf_sk_assign(struct bpf_sk_lookup *ctx, struct bpf_sock *sk, u64 flags)
3984 * Helper is overloaded depending on BPF program type. This
3985 * description applies to **BPF_PROG_TYPE_SK_LOOKUP** programs.
3987 * Select the *sk* as a result of a socket lookup.
3989 * For the operation to succeed passed socket must be compatible
3990 * with the packet description provided by the *ctx* object.
3992 * L4 protocol (**IPPROTO_TCP** or **IPPROTO_UDP**) must
3993 * be an exact match. While IP family (**AF_INET** or
3994 * **AF_INET6**) must be compatible, that is IPv6 sockets
3995 * that are not v6-only can be selected for IPv4 packets.
3997 * Only TCP listeners and UDP unconnected sockets can be
3998 * selected. *sk* can also be NULL to reset any previous
4001 * *flags* argument can combination of following values:
4003 * * **BPF_SK_LOOKUP_F_REPLACE** to override the previous
4004 * socket selection, potentially done by a BPF program
4005 * that ran before us.
4007 * * **BPF_SK_LOOKUP_F_NO_REUSEPORT** to skip
4008 * load-balancing within reuseport group for the socket
4011 * On success *ctx->sk* will point to the selected socket.
4014 * 0 on success, or a negative errno in case of failure.
4016 * * **-EAFNOSUPPORT** if socket family (*sk->family*) is
4017 * not compatible with packet family (*ctx->family*).
4019 * * **-EEXIST** if socket has been already selected,
4020 * potentially by another program, and
4021 * **BPF_SK_LOOKUP_F_REPLACE** flag was not specified.
4023 * * **-EINVAL** if unsupported flags were specified.
4025 * * **-EPROTOTYPE** if socket L4 protocol
4026 * (*sk->protocol*) doesn't match packet protocol
4027 * (*ctx->protocol*).
4029 * * **-ESOCKTNOSUPPORT** if socket is not in allowed
4030 * state (TCP listening or UDP unconnected).
4032 * u64 bpf_ktime_get_boot_ns(void)
4034 * Return the time elapsed since system boot, in nanoseconds.
4035 * Does include the time the system was suspended.
4036 * See: **clock_gettime**\ (**CLOCK_BOOTTIME**)
4040 * long bpf_seq_printf(struct seq_file *m, const char *fmt, u32 fmt_size, const void *data, u32 data_len)
4042 * **bpf_seq_printf**\ () uses seq_file **seq_printf**\ () to print
4043 * out the format string.
4044 * The *m* represents the seq_file. The *fmt* and *fmt_size* are for
4045 * the format string itself. The *data* and *data_len* are format string
4046 * arguments. The *data* are a **u64** array and corresponding format string
4047 * values are stored in the array. For strings and pointers where pointees
4048 * are accessed, only the pointer values are stored in the *data* array.
4049 * The *data_len* is the size of *data* in bytes.
4051 * Formats **%s**, **%p{i,I}{4,6}** requires to read kernel memory.
4052 * Reading kernel memory may fail due to either invalid address or
4053 * valid address but requiring a major memory fault. If reading kernel memory
4054 * fails, the string for **%s** will be an empty string, and the ip
4055 * address for **%p{i,I}{4,6}** will be 0. Not returning error to
4056 * bpf program is consistent with what **bpf_trace_printk**\ () does for now.
4058 * 0 on success, or a negative error in case of failure:
4060 * **-EBUSY** if per-CPU memory copy buffer is busy, can try again
4061 * by returning 1 from bpf program.
4063 * **-EINVAL** if arguments are invalid, or if *fmt* is invalid/unsupported.
4065 * **-E2BIG** if *fmt* contains too many format specifiers.
4067 * **-EOVERFLOW** if an overflow happened: The same object will be tried again.
4069 * long bpf_seq_write(struct seq_file *m, const void *data, u32 len)
4071 * **bpf_seq_write**\ () uses seq_file **seq_write**\ () to write the data.
4072 * The *m* represents the seq_file. The *data* and *len* represent the
4073 * data to write in bytes.
4075 * 0 on success, or a negative error in case of failure:
4077 * **-EOVERFLOW** if an overflow happened: The same object will be tried again.
4079 * u64 bpf_sk_cgroup_id(void *sk)
4081 * Return the cgroup v2 id of the socket *sk*.
4083 * *sk* must be a non-**NULL** pointer to a socket, e.g. one
4084 * returned from **bpf_sk_lookup_xxx**\ (),
4085 * **bpf_sk_fullsock**\ (), etc. The format of returned id is
4086 * same as in **bpf_skb_cgroup_id**\ ().
4088 * This helper is available only if the kernel was compiled with
4089 * the **CONFIG_SOCK_CGROUP_DATA** configuration option.
4091 * The id is returned or 0 in case the id could not be retrieved.
4093 * u64 bpf_sk_ancestor_cgroup_id(void *sk, int ancestor_level)
4095 * Return id of cgroup v2 that is ancestor of cgroup associated
4096 * with the *sk* at the *ancestor_level*. The root cgroup is at
4097 * *ancestor_level* zero and each step down the hierarchy
4098 * increments the level. If *ancestor_level* == level of cgroup
4099 * associated with *sk*, then return value will be same as that
4100 * of **bpf_sk_cgroup_id**\ ().
4102 * The helper is useful to implement policies based on cgroups
4103 * that are upper in hierarchy than immediate cgroup associated
4106 * The format of returned id and helper limitations are same as in
4107 * **bpf_sk_cgroup_id**\ ().
4109 * The id is returned or 0 in case the id could not be retrieved.
4111 * long bpf_ringbuf_output(void *ringbuf, void *data, u64 size, u64 flags)
4113 * Copy *size* bytes from *data* into a ring buffer *ringbuf*.
4114 * If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
4115 * of new data availability is sent.
4116 * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
4117 * of new data availability is sent unconditionally.
4118 * If **0** is specified in *flags*, an adaptive notification
4119 * of new data availability is sent.
4121 * An adaptive notification is a notification sent whenever the user-space
4122 * process has caught up and consumed all available payloads. In case the user-space
4123 * process is still processing a previous payload, then no notification is needed
4124 * as it will process the newly added payload automatically.
4126 * 0 on success, or a negative error in case of failure.
4128 * void *bpf_ringbuf_reserve(void *ringbuf, u64 size, u64 flags)
4130 * Reserve *size* bytes of payload in a ring buffer *ringbuf*.
4131 * *flags* must be 0.
4133 * Valid pointer with *size* bytes of memory available; NULL,
4136 * void bpf_ringbuf_submit(void *data, u64 flags)
4138 * Submit reserved ring buffer sample, pointed to by *data*.
4139 * If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
4140 * of new data availability is sent.
4141 * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
4142 * of new data availability is sent unconditionally.
4143 * If **0** is specified in *flags*, an adaptive notification
4144 * of new data availability is sent.
4146 * See 'bpf_ringbuf_output()' for the definition of adaptive notification.
4148 * Nothing. Always succeeds.
4150 * void bpf_ringbuf_discard(void *data, u64 flags)
4152 * Discard reserved ring buffer sample, pointed to by *data*.
4153 * If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
4154 * of new data availability is sent.
4155 * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
4156 * of new data availability is sent unconditionally.
4157 * If **0** is specified in *flags*, an adaptive notification
4158 * of new data availability is sent.
4160 * See 'bpf_ringbuf_output()' for the definition of adaptive notification.
4162 * Nothing. Always succeeds.
4164 * u64 bpf_ringbuf_query(void *ringbuf, u64 flags)
4166 * Query various characteristics of provided ring buffer. What
4167 * exactly is queries is determined by *flags*:
4169 * * **BPF_RB_AVAIL_DATA**: Amount of data not yet consumed.
4170 * * **BPF_RB_RING_SIZE**: The size of ring buffer.
4171 * * **BPF_RB_CONS_POS**: Consumer position (can wrap around).
4172 * * **BPF_RB_PROD_POS**: Producer(s) position (can wrap around).
4174 * Data returned is just a momentary snapshot of actual values
4175 * and could be inaccurate, so this facility should be used to
4176 * power heuristics and for reporting, not to make 100% correct
4179 * Requested value, or 0, if *flags* are not recognized.
4181 * long bpf_csum_level(struct sk_buff *skb, u64 level)
4183 * Change the skbs checksum level by one layer up or down, or
4184 * reset it entirely to none in order to have the stack perform
4185 * checksum validation. The level is applicable to the following
4186 * protocols: TCP, UDP, GRE, SCTP, FCOE. For example, a decap of
4187 * | ETH | IP | UDP | GUE | IP | TCP | into | ETH | IP | TCP |
4188 * through **bpf_skb_adjust_room**\ () helper with passing in
4189 * **BPF_F_ADJ_ROOM_NO_CSUM_RESET** flag would require one call
4190 * to **bpf_csum_level**\ () with **BPF_CSUM_LEVEL_DEC** since
4191 * the UDP header is removed. Similarly, an encap of the latter
4192 * into the former could be accompanied by a helper call to
4193 * **bpf_csum_level**\ () with **BPF_CSUM_LEVEL_INC** if the
4194 * skb is still intended to be processed in higher layers of the
4195 * stack instead of just egressing at tc.
4197 * There are three supported level settings at this time:
4199 * * **BPF_CSUM_LEVEL_INC**: Increases skb->csum_level for skbs
4200 * with CHECKSUM_UNNECESSARY.
4201 * * **BPF_CSUM_LEVEL_DEC**: Decreases skb->csum_level for skbs
4202 * with CHECKSUM_UNNECESSARY.
4203 * * **BPF_CSUM_LEVEL_RESET**: Resets skb->csum_level to 0 and
4204 * sets CHECKSUM_NONE to force checksum validation by the stack.
4205 * * **BPF_CSUM_LEVEL_QUERY**: No-op, returns the current
4208 * 0 on success, or a negative error in case of failure. In the
4209 * case of **BPF_CSUM_LEVEL_QUERY**, the current skb->csum_level
4210 * is returned or the error code -EACCES in case the skb is not
4211 * subject to CHECKSUM_UNNECESSARY.
4213 * struct tcp6_sock *bpf_skc_to_tcp6_sock(void *sk)
4215 * Dynamically cast a *sk* pointer to a *tcp6_sock* pointer.
4217 * *sk* if casting is valid, or **NULL** otherwise.
4219 * struct tcp_sock *bpf_skc_to_tcp_sock(void *sk)
4221 * Dynamically cast a *sk* pointer to a *tcp_sock* pointer.
4223 * *sk* if casting is valid, or **NULL** otherwise.
4225 * struct tcp_timewait_sock *bpf_skc_to_tcp_timewait_sock(void *sk)
4227 * Dynamically cast a *sk* pointer to a *tcp_timewait_sock* pointer.
4229 * *sk* if casting is valid, or **NULL** otherwise.
4231 * struct tcp_request_sock *bpf_skc_to_tcp_request_sock(void *sk)
4233 * Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer.
4235 * *sk* if casting is valid, or **NULL** otherwise.
4237 * struct udp6_sock *bpf_skc_to_udp6_sock(void *sk)
4239 * Dynamically cast a *sk* pointer to a *udp6_sock* pointer.
4241 * *sk* if casting is valid, or **NULL** otherwise.
4243 * long bpf_get_task_stack(struct task_struct *task, void *buf, u32 size, u64 flags)
4245 * Return a user or a kernel stack in bpf program provided buffer.
4246 * To achieve this, the helper needs *task*, which is a valid
4247 * pointer to **struct task_struct**. To store the stacktrace, the
4248 * bpf program provides *buf* with a nonnegative *size*.
4250 * The last argument, *flags*, holds the number of stack frames to
4251 * skip (from 0 to 255), masked with
4252 * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
4253 * the following flags:
4255 * **BPF_F_USER_STACK**
4256 * Collect a user space stack instead of a kernel stack.
4257 * **BPF_F_USER_BUILD_ID**
4258 * Collect buildid+offset instead of ips for user stack,
4259 * only valid if **BPF_F_USER_STACK** is also specified.
4261 * **bpf_get_task_stack**\ () can collect up to
4262 * **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject
4263 * to sufficient large buffer size. Note that
4264 * this limit can be controlled with the **sysctl** program, and
4265 * that it should be manually increased in order to profile long
4266 * user stacks (such as stacks for Java programs). To do so, use:
4270 * # sysctl kernel.perf_event_max_stack=<new value>
4272 * A non-negative value equal to or less than *size* on success,
4273 * or a negative error in case of failure.
4275 * long bpf_load_hdr_opt(struct bpf_sock_ops *skops, void *searchby_res, u32 len, u64 flags)
4277 * Load header option. Support reading a particular TCP header
4278 * option for bpf program (**BPF_PROG_TYPE_SOCK_OPS**).
4280 * If *flags* is 0, it will search the option from the
4281 * *skops*\ **->skb_data**. The comment in **struct bpf_sock_ops**
4282 * has details on what skb_data contains under different
4283 * *skops*\ **->op**.
4285 * The first byte of the *searchby_res* specifies the
4286 * kind that it wants to search.
4288 * If the searching kind is an experimental kind
4289 * (i.e. 253 or 254 according to RFC6994). It also
4290 * needs to specify the "magic" which is either
4291 * 2 bytes or 4 bytes. It then also needs to
4292 * specify the size of the magic by using
4293 * the 2nd byte which is "kind-length" of a TCP
4294 * header option and the "kind-length" also
4295 * includes the first 2 bytes "kind" and "kind-length"
4296 * itself as a normal TCP header option also does.
4298 * For example, to search experimental kind 254 with
4299 * 2 byte magic 0xeB9F, the searchby_res should be
4300 * [ 254, 4, 0xeB, 0x9F, 0, 0, .... 0 ].
4302 * To search for the standard window scale option (3),
4303 * the *searchby_res* should be [ 3, 0, 0, .... 0 ].
4304 * Note, kind-length must be 0 for regular option.
4306 * Searching for No-Op (0) and End-of-Option-List (1) are
4309 * *len* must be at least 2 bytes which is the minimal size
4310 * of a header option.
4314 * * **BPF_LOAD_HDR_OPT_TCP_SYN** to search from the
4315 * saved_syn packet or the just-received syn packet.
4318 * > 0 when found, the header option is copied to *searchby_res*.
4319 * The return value is the total length copied. On failure, a
4320 * negative error code is returned:
4322 * **-EINVAL** if a parameter is invalid.
4324 * **-ENOMSG** if the option is not found.
4326 * **-ENOENT** if no syn packet is available when
4327 * **BPF_LOAD_HDR_OPT_TCP_SYN** is used.
4329 * **-ENOSPC** if there is not enough space. Only *len* number of
4332 * **-EFAULT** on failure to parse the header options in the
4335 * **-EPERM** if the helper cannot be used under the current
4336 * *skops*\ **->op**.
4338 * long bpf_store_hdr_opt(struct bpf_sock_ops *skops, const void *from, u32 len, u64 flags)
4340 * Store header option. The data will be copied
4341 * from buffer *from* with length *len* to the TCP header.
4343 * The buffer *from* should have the whole option that
4344 * includes the kind, kind-length, and the actual
4345 * option data. The *len* must be at least kind-length
4346 * long. The kind-length does not have to be 4 byte
4347 * aligned. The kernel will take care of the padding
4348 * and setting the 4 bytes aligned value to th->doff.
4350 * This helper will check for duplicated option
4351 * by searching the same option in the outgoing skb.
4353 * This helper can only be called during
4354 * **BPF_SOCK_OPS_WRITE_HDR_OPT_CB**.
4357 * 0 on success, or negative error in case of failure:
4359 * **-EINVAL** If param is invalid.
4361 * **-ENOSPC** if there is not enough space in the header.
4362 * Nothing has been written
4364 * **-EEXIST** if the option already exists.
4366 * **-EFAULT** on failrue to parse the existing header options.
4368 * **-EPERM** if the helper cannot be used under the current
4369 * *skops*\ **->op**.
4371 * long bpf_reserve_hdr_opt(struct bpf_sock_ops *skops, u32 len, u64 flags)
4373 * Reserve *len* bytes for the bpf header option. The
4374 * space will be used by **bpf_store_hdr_opt**\ () later in
4375 * **BPF_SOCK_OPS_WRITE_HDR_OPT_CB**.
4377 * If **bpf_reserve_hdr_opt**\ () is called multiple times,
4378 * the total number of bytes will be reserved.
4380 * This helper can only be called during
4381 * **BPF_SOCK_OPS_HDR_OPT_LEN_CB**.
4384 * 0 on success, or negative error in case of failure:
4386 * **-EINVAL** if a parameter is invalid.
4388 * **-ENOSPC** if there is not enough space in the header.
4390 * **-EPERM** if the helper cannot be used under the current
4391 * *skops*\ **->op**.
4393 * void *bpf_inode_storage_get(struct bpf_map *map, void *inode, void *value, u64 flags)
4395 * Get a bpf_local_storage from an *inode*.
4397 * Logically, it could be thought of as getting the value from
4398 * a *map* with *inode* as the **key**. From this
4399 * perspective, the usage is not much different from
4400 * **bpf_map_lookup_elem**\ (*map*, **&**\ *inode*) except this
4401 * helper enforces the key must be an inode and the map must also
4402 * be a **BPF_MAP_TYPE_INODE_STORAGE**.
4404 * Underneath, the value is stored locally at *inode* instead of
4405 * the *map*. The *map* is used as the bpf-local-storage
4406 * "type". The bpf-local-storage "type" (i.e. the *map*) is
4407 * searched against all bpf_local_storage residing at *inode*.
4409 * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be
4410 * used such that a new bpf_local_storage will be
4411 * created if one does not exist. *value* can be used
4412 * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify
4413 * the initial value of a bpf_local_storage. If *value* is
4414 * **NULL**, the new bpf_local_storage will be zero initialized.
4416 * A bpf_local_storage pointer is returned on success.
4418 * **NULL** if not found or there was an error in adding
4419 * a new bpf_local_storage.
4421 * int bpf_inode_storage_delete(struct bpf_map *map, void *inode)
4423 * Delete a bpf_local_storage from an *inode*.
4427 * **-ENOENT** if the bpf_local_storage cannot be found.
4429 * long bpf_d_path(struct path *path, char *buf, u32 sz)
4431 * Return full path for given **struct path** object, which
4432 * needs to be the kernel BTF *path* object. The path is
4433 * returned in the provided buffer *buf* of size *sz* and
4434 * is zero terminated.
4437 * On success, the strictly positive length of the string,
4438 * including the trailing NUL character. On error, a negative
4441 * long bpf_copy_from_user(void *dst, u32 size, const void *user_ptr)
4443 * Read *size* bytes from user space address *user_ptr* and store
4444 * the data in *dst*. This is a wrapper of **copy_from_user**\ ().
4446 * 0 on success, or a negative error in case of failure.
4448 * long bpf_snprintf_btf(char *str, u32 str_size, struct btf_ptr *ptr, u32 btf_ptr_size, u64 flags)
4450 * Use BTF to store a string representation of *ptr*->ptr in *str*,
4451 * using *ptr*->type_id. This value should specify the type
4452 * that *ptr*->ptr points to. LLVM __builtin_btf_type_id(type, 1)
4453 * can be used to look up vmlinux BTF type ids. Traversing the
4454 * data structure using BTF, the type information and values are
4455 * stored in the first *str_size* - 1 bytes of *str*. Safe copy of
4456 * the pointer data is carried out to avoid kernel crashes during
4457 * operation. Smaller types can use string space on the stack;
4458 * larger programs can use map data to store the string
4461 * The string can be subsequently shared with userspace via
4462 * bpf_perf_event_output() or ring buffer interfaces.
4463 * bpf_trace_printk() is to be avoided as it places too small
4464 * a limit on string size to be useful.
4466 * *flags* is a combination of
4469 * no formatting around type information
4471 * no struct/union member names/types
4473 * show raw (unobfuscated) pointer values;
4474 * equivalent to printk specifier %px.
4476 * show zero-valued struct/union members; they
4477 * are not displayed by default
4480 * The number of bytes that were written (or would have been
4481 * written if output had to be truncated due to string size),
4482 * or a negative error in cases of failure.
4484 * long bpf_seq_printf_btf(struct seq_file *m, struct btf_ptr *ptr, u32 ptr_size, u64 flags)
4486 * Use BTF to write to seq_write a string representation of
4487 * *ptr*->ptr, using *ptr*->type_id as per bpf_snprintf_btf().
4488 * *flags* are identical to those used for bpf_snprintf_btf.
4490 * 0 on success or a negative error in case of failure.
4492 * u64 bpf_skb_cgroup_classid(struct sk_buff *skb)
4494 * See **bpf_get_cgroup_classid**\ () for the main description.
4495 * This helper differs from **bpf_get_cgroup_classid**\ () in that
4496 * the cgroup v1 net_cls class is retrieved only from the *skb*'s
4497 * associated socket instead of the current process.
4499 * The id is returned or 0 in case the id could not be retrieved.
4501 * long bpf_redirect_neigh(u32 ifindex, struct bpf_redir_neigh *params, int plen, u64 flags)
4503 * Redirect the packet to another net device of index *ifindex*
4504 * and fill in L2 addresses from neighboring subsystem. This helper
4505 * is somewhat similar to **bpf_redirect**\ (), except that it
4506 * populates L2 addresses as well, meaning, internally, the helper
4507 * relies on the neighbor lookup for the L2 address of the nexthop.
4509 * The helper will perform a FIB lookup based on the skb's
4510 * networking header to get the address of the next hop, unless
4511 * this is supplied by the caller in the *params* argument. The
4512 * *plen* argument indicates the len of *params* and should be set
4513 * to 0 if *params* is NULL.
4515 * The *flags* argument is reserved and must be 0. The helper is
4516 * currently only supported for tc BPF program types, and enabled
4517 * for IPv4 and IPv6 protocols.
4519 * The helper returns **TC_ACT_REDIRECT** on success or
4520 * **TC_ACT_SHOT** on error.
4522 * void *bpf_per_cpu_ptr(const void *percpu_ptr, u32 cpu)
4524 * Take a pointer to a percpu ksym, *percpu_ptr*, and return a
4525 * pointer to the percpu kernel variable on *cpu*. A ksym is an
4526 * extern variable decorated with '__ksym'. For ksym, there is a
4527 * global var (either static or global) defined of the same name
4528 * in the kernel. The ksym is percpu if the global var is percpu.
4529 * The returned pointer points to the global percpu var on *cpu*.
4531 * bpf_per_cpu_ptr() has the same semantic as per_cpu_ptr() in the
4532 * kernel, except that bpf_per_cpu_ptr() may return NULL. This
4533 * happens if *cpu* is larger than nr_cpu_ids. The caller of
4534 * bpf_per_cpu_ptr() must check the returned value.
4536 * A pointer pointing to the kernel percpu variable on *cpu*, or
4537 * NULL, if *cpu* is invalid.
4539 * void *bpf_this_cpu_ptr(const void *percpu_ptr)
4541 * Take a pointer to a percpu ksym, *percpu_ptr*, and return a
4542 * pointer to the percpu kernel variable on this cpu. See the
4543 * description of 'ksym' in **bpf_per_cpu_ptr**\ ().
4545 * bpf_this_cpu_ptr() has the same semantic as this_cpu_ptr() in
4546 * the kernel. Different from **bpf_per_cpu_ptr**\ (), it would
4547 * never return NULL.
4549 * A pointer pointing to the kernel percpu variable on this cpu.
4551 * long bpf_redirect_peer(u32 ifindex, u64 flags)
4553 * Redirect the packet to another net device of index *ifindex*.
4554 * This helper is somewhat similar to **bpf_redirect**\ (), except
4555 * that the redirection happens to the *ifindex*' peer device and
4556 * the netns switch takes place from ingress to ingress without
4557 * going through the CPU's backlog queue.
4559 * The *flags* argument is reserved and must be 0. The helper is
4560 * currently only supported for tc BPF program types at the ingress
4561 * hook and for veth device types. The peer device must reside in a
4562 * different network namespace.
4564 * The helper returns **TC_ACT_REDIRECT** on success or
4565 * **TC_ACT_SHOT** on error.
4567 * void *bpf_task_storage_get(struct bpf_map *map, struct task_struct *task, void *value, u64 flags)
4569 * Get a bpf_local_storage from the *task*.
4571 * Logically, it could be thought of as getting the value from
4572 * a *map* with *task* as the **key**. From this
4573 * perspective, the usage is not much different from
4574 * **bpf_map_lookup_elem**\ (*map*, **&**\ *task*) except this
4575 * helper enforces the key must be an task_struct and the map must also
4576 * be a **BPF_MAP_TYPE_TASK_STORAGE**.
4578 * Underneath, the value is stored locally at *task* instead of
4579 * the *map*. The *map* is used as the bpf-local-storage
4580 * "type". The bpf-local-storage "type" (i.e. the *map*) is
4581 * searched against all bpf_local_storage residing at *task*.
4583 * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be
4584 * used such that a new bpf_local_storage will be
4585 * created if one does not exist. *value* can be used
4586 * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify
4587 * the initial value of a bpf_local_storage. If *value* is
4588 * **NULL**, the new bpf_local_storage will be zero initialized.
4590 * A bpf_local_storage pointer is returned on success.
4592 * **NULL** if not found or there was an error in adding
4593 * a new bpf_local_storage.
4595 * long bpf_task_storage_delete(struct bpf_map *map, struct task_struct *task)
4597 * Delete a bpf_local_storage from a *task*.
4601 * **-ENOENT** if the bpf_local_storage cannot be found.
4603 * struct task_struct *bpf_get_current_task_btf(void)
4605 * Return a BTF pointer to the "current" task.
4606 * This pointer can also be used in helpers that accept an
4607 * *ARG_PTR_TO_BTF_ID* of type *task_struct*.
4609 * Pointer to the current task.
4611 * long bpf_bprm_opts_set(struct linux_binprm *bprm, u64 flags)
4613 * Set or clear certain options on *bprm*:
4615 * **BPF_F_BPRM_SECUREEXEC** Set the secureexec bit
4616 * which sets the **AT_SECURE** auxv for glibc. The bit
4617 * is cleared if the flag is not specified.
4619 * **-EINVAL** if invalid *flags* are passed, zero otherwise.
4621 * u64 bpf_ktime_get_coarse_ns(void)
4623 * Return a coarse-grained version of the time elapsed since
4624 * system boot, in nanoseconds. Does not include time the system
4627 * See: **clock_gettime**\ (**CLOCK_MONOTONIC_COARSE**)
4631 * long bpf_ima_inode_hash(struct inode *inode, void *dst, u32 size)
4633 * Returns the stored IMA hash of the *inode* (if it's avaialable).
4634 * If the hash is larger than *size*, then only *size*
4635 * bytes will be copied to *dst*
4637 * The **hash_algo** is returned on success,
4638 * **-EOPNOTSUP** if IMA is disabled or **-EINVAL** if
4639 * invalid arguments are passed.
4641 * struct socket *bpf_sock_from_file(struct file *file)
4643 * If the given file represents a socket, returns the associated
4646 * A pointer to a struct socket on success or NULL if the file is
4649 * long bpf_check_mtu(void *ctx, u32 ifindex, u32 *mtu_len, s32 len_diff, u64 flags)
4651 * Check packet size against exceeding MTU of net device (based
4652 * on *ifindex*). This helper will likely be used in combination
4653 * with helpers that adjust/change the packet size.
4655 * The argument *len_diff* can be used for querying with a planned
4656 * size change. This allows to check MTU prior to changing packet
4657 * ctx. Providing an *len_diff* adjustment that is larger than the
4658 * actual packet size (resulting in negative packet size) will in
4659 * principle not exceed the MTU, why it is not considered a
4660 * failure. Other BPF-helpers are needed for performing the
4661 * planned size change, why the responsability for catch a negative
4662 * packet size belong in those helpers.
4664 * Specifying *ifindex* zero means the MTU check is performed
4665 * against the current net device. This is practical if this isn't
4666 * used prior to redirect.
4668 * On input *mtu_len* must be a valid pointer, else verifier will
4669 * reject BPF program. If the value *mtu_len* is initialized to
4670 * zero then the ctx packet size is use. When value *mtu_len* is
4671 * provided as input this specify the L3 length that the MTU check
4672 * is done against. Remember XDP and TC length operate at L2, but
4673 * this value is L3 as this correlate to MTU and IP-header tot_len
4674 * values which are L3 (similar behavior as bpf_fib_lookup).
4676 * The Linux kernel route table can configure MTUs on a more
4677 * specific per route level, which is not provided by this helper.
4678 * For route level MTU checks use the **bpf_fib_lookup**\ ()
4681 * *ctx* is either **struct xdp_md** for XDP programs or
4682 * **struct sk_buff** for tc cls_act programs.
4684 * The *flags* argument can be a combination of one or more of the
4687 * **BPF_MTU_CHK_SEGS**
4688 * This flag will only works for *ctx* **struct sk_buff**.
4689 * If packet context contains extra packet segment buffers
4690 * (often knows as GSO skb), then MTU check is harder to
4691 * check at this point, because in transmit path it is
4692 * possible for the skb packet to get re-segmented
4693 * (depending on net device features). This could still be
4694 * a MTU violation, so this flag enables performing MTU
4695 * check against segments, with a different violation
4696 * return code to tell it apart. Check cannot use len_diff.
4698 * On return *mtu_len* pointer contains the MTU value of the net
4699 * device. Remember the net device configured MTU is the L3 size,
4700 * which is returned here and XDP and TC length operate at L2.
4701 * Helper take this into account for you, but remember when using
4702 * MTU value in your BPF-code.
4705 * * 0 on success, and populate MTU value in *mtu_len* pointer.
4707 * * < 0 if any input argument is invalid (*mtu_len* not updated)
4709 * MTU violations return positive values, but also populate MTU
4710 * value in *mtu_len* pointer, as this can be needed for
4711 * implementing PMTU handing:
4713 * * **BPF_MTU_CHK_RET_FRAG_NEEDED**
4714 * * **BPF_MTU_CHK_RET_SEGS_TOOBIG**
4716 * long bpf_for_each_map_elem(struct bpf_map *map, void *callback_fn, void *callback_ctx, u64 flags)
4718 * For each element in **map**, call **callback_fn** function with
4719 * **map**, **callback_ctx** and other map-specific parameters.
4720 * The **callback_fn** should be a static function and
4721 * the **callback_ctx** should be a pointer to the stack.
4722 * The **flags** is used to control certain aspects of the helper.
4723 * Currently, the **flags** must be 0.
4725 * The following are a list of supported map types and their
4726 * respective expected callback signatures:
4728 * BPF_MAP_TYPE_HASH, BPF_MAP_TYPE_PERCPU_HASH,
4729 * BPF_MAP_TYPE_LRU_HASH, BPF_MAP_TYPE_LRU_PERCPU_HASH,
4730 * BPF_MAP_TYPE_ARRAY, BPF_MAP_TYPE_PERCPU_ARRAY
4732 * long (\*callback_fn)(struct bpf_map \*map, const void \*key, void \*value, void \*ctx);
4734 * For per_cpu maps, the map_value is the value on the cpu where the
4735 * bpf_prog is running.
4737 * If **callback_fn** return 0, the helper will continue to the next
4738 * element. If return value is 1, the helper will skip the rest of
4739 * elements and return. Other return values are not used now.
4742 * The number of traversed map elements for success, **-EINVAL** for
4743 * invalid **flags**.
4745 * long bpf_snprintf(char *str, u32 str_size, const char *fmt, u64 *data, u32 data_len)
4747 * Outputs a string into the **str** buffer of size **str_size**
4748 * based on a format string stored in a read-only map pointed by
4751 * Each format specifier in **fmt** corresponds to one u64 element
4752 * in the **data** array. For strings and pointers where pointees
4753 * are accessed, only the pointer values are stored in the *data*
4754 * array. The *data_len* is the size of *data* in bytes.
4756 * Formats **%s** and **%p{i,I}{4,6}** require to read kernel
4757 * memory. Reading kernel memory may fail due to either invalid
4758 * address or valid address but requiring a major memory fault. If
4759 * reading kernel memory fails, the string for **%s** will be an
4760 * empty string, and the ip address for **%p{i,I}{4,6}** will be 0.
4761 * Not returning error to bpf program is consistent with what
4762 * **bpf_trace_printk**\ () does for now.
4765 * The strictly positive length of the formatted string, including
4766 * the trailing zero character. If the return value is greater than
4767 * **str_size**, **str** contains a truncated string, guaranteed to
4768 * be zero-terminated except when **str_size** is 0.
4770 * Or **-EBUSY** if the per-CPU memory copy buffer is busy.
4772 * long bpf_sys_bpf(u32 cmd, void *attr, u32 attr_size)
4774 * Execute bpf syscall with given arguments.
4778 * long bpf_btf_find_by_name_kind(char *name, int name_sz, u32 kind, int flags)
4780 * Find BTF type with given name and kind in vmlinux BTF or in module's BTFs.
4782 * Returns btf_id and btf_obj_fd in lower and upper 32 bits.
4784 * long bpf_sys_close(u32 fd)
4786 * Execute close syscall for given FD.
4790 * long bpf_timer_init(struct bpf_timer *timer, struct bpf_map *map, u64 flags)
4792 * Initialize the timer.
4793 * First 4 bits of *flags* specify clockid.
4794 * Only CLOCK_MONOTONIC, CLOCK_REALTIME, CLOCK_BOOTTIME are allowed.
4795 * All other bits of *flags* are reserved.
4796 * The verifier will reject the program if *timer* is not from
4800 * **-EBUSY** if *timer* is already initialized.
4801 * **-EINVAL** if invalid *flags* are passed.
4802 * **-EPERM** if *timer* is in a map that doesn't have any user references.
4803 * The user space should either hold a file descriptor to a map with timers
4804 * or pin such map in bpffs. When map is unpinned or file descriptor is
4805 * closed all timers in the map will be cancelled and freed.
4807 * long bpf_timer_set_callback(struct bpf_timer *timer, void *callback_fn)
4809 * Configure the timer to call *callback_fn* static function.
4812 * **-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier.
4813 * **-EPERM** if *timer* is in a map that doesn't have any user references.
4814 * The user space should either hold a file descriptor to a map with timers
4815 * or pin such map in bpffs. When map is unpinned or file descriptor is
4816 * closed all timers in the map will be cancelled and freed.
4818 * long bpf_timer_start(struct bpf_timer *timer, u64 nsecs, u64 flags)
4820 * Set timer expiration N nanoseconds from the current time. The
4821 * configured callback will be invoked in soft irq context on some cpu
4822 * and will not repeat unless another bpf_timer_start() is made.
4823 * In such case the next invocation can migrate to a different cpu.
4824 * Since struct bpf_timer is a field inside map element the map
4825 * owns the timer. The bpf_timer_set_callback() will increment refcnt
4826 * of BPF program to make sure that callback_fn code stays valid.
4827 * When user space reference to a map reaches zero all timers
4828 * in a map are cancelled and corresponding program's refcnts are
4829 * decremented. This is done to make sure that Ctrl-C of a user
4830 * process doesn't leave any timers running. If map is pinned in
4831 * bpffs the callback_fn can re-arm itself indefinitely.
4832 * bpf_map_update/delete_elem() helpers and user space sys_bpf commands
4833 * cancel and free the timer in the given map element.
4834 * The map can contain timers that invoke callback_fn-s from different
4835 * programs. The same callback_fn can serve different timers from
4836 * different maps if key/value layout matches across maps.
4837 * Every bpf_timer_set_callback() can have different callback_fn.
4841 * **-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier
4842 * or invalid *flags* are passed.
4844 * long bpf_timer_cancel(struct bpf_timer *timer)
4846 * Cancel the timer and wait for callback_fn to finish if it was running.
4848 * 0 if the timer was not active.
4849 * 1 if the timer was active.
4850 * **-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier.
4851 * **-EDEADLK** if callback_fn tried to call bpf_timer_cancel() on its
4852 * own timer which would have led to a deadlock otherwise.
4854 * u64 bpf_get_func_ip(void *ctx)
4856 * Get address of the traced function (for tracing and kprobe programs).
4858 * Address of the traced function.
4860 * u64 bpf_get_attach_cookie(void *ctx)
4862 * Get bpf_cookie value provided (optionally) during the program
4863 * attachment. It might be different for each individual
4864 * attachment, even if BPF program itself is the same.
4865 * Expects BPF program context *ctx* as a first argument.
4867 * Supported for the following program types:
4872 * Value specified by user at BPF link creation/attachment time
4873 * or 0, if it was not specified.
4875 * long bpf_task_pt_regs(struct task_struct *task)
4877 * Get the struct pt_regs associated with **task**.
4879 * A pointer to struct pt_regs.
4881 #define __BPF_FUNC_MAPPER(FN) \
4883 FN(map_lookup_elem), \
4884 FN(map_update_elem), \
4885 FN(map_delete_elem), \
4889 FN(get_prandom_u32), \
4890 FN(get_smp_processor_id), \
4891 FN(skb_store_bytes), \
4892 FN(l3_csum_replace), \
4893 FN(l4_csum_replace), \
4895 FN(clone_redirect), \
4896 FN(get_current_pid_tgid), \
4897 FN(get_current_uid_gid), \
4898 FN(get_current_comm), \
4899 FN(get_cgroup_classid), \
4900 FN(skb_vlan_push), \
4902 FN(skb_get_tunnel_key), \
4903 FN(skb_set_tunnel_key), \
4904 FN(perf_event_read), \
4906 FN(get_route_realm), \
4907 FN(perf_event_output), \
4908 FN(skb_load_bytes), \
4911 FN(skb_get_tunnel_opt), \
4912 FN(skb_set_tunnel_opt), \
4913 FN(skb_change_proto), \
4914 FN(skb_change_type), \
4915 FN(skb_under_cgroup), \
4916 FN(get_hash_recalc), \
4917 FN(get_current_task), \
4918 FN(probe_write_user), \
4919 FN(current_task_under_cgroup), \
4920 FN(skb_change_tail), \
4921 FN(skb_pull_data), \
4923 FN(set_hash_invalid), \
4924 FN(get_numa_node_id), \
4925 FN(skb_change_head), \
4926 FN(xdp_adjust_head), \
4927 FN(probe_read_str), \
4928 FN(get_socket_cookie), \
4929 FN(get_socket_uid), \
4932 FN(skb_adjust_room), \
4934 FN(sk_redirect_map), \
4935 FN(sock_map_update), \
4936 FN(xdp_adjust_meta), \
4937 FN(perf_event_read_value), \
4938 FN(perf_prog_read_value), \
4940 FN(override_return), \
4941 FN(sock_ops_cb_flags_set), \
4942 FN(msg_redirect_map), \
4943 FN(msg_apply_bytes), \
4944 FN(msg_cork_bytes), \
4945 FN(msg_pull_data), \
4947 FN(xdp_adjust_tail), \
4948 FN(skb_get_xfrm_state), \
4950 FN(skb_load_bytes_relative), \
4952 FN(sock_hash_update), \
4953 FN(msg_redirect_hash), \
4954 FN(sk_redirect_hash), \
4955 FN(lwt_push_encap), \
4956 FN(lwt_seg6_store_bytes), \
4957 FN(lwt_seg6_adjust_srh), \
4958 FN(lwt_seg6_action), \
4961 FN(skb_cgroup_id), \
4962 FN(get_current_cgroup_id), \
4963 FN(get_local_storage), \
4964 FN(sk_select_reuseport), \
4965 FN(skb_ancestor_cgroup_id), \
4966 FN(sk_lookup_tcp), \
4967 FN(sk_lookup_udp), \
4969 FN(map_push_elem), \
4971 FN(map_peek_elem), \
4972 FN(msg_push_data), \
4974 FN(rc_pointer_rel), \
4979 FN(skb_ecn_set_ce), \
4980 FN(get_listener_sock), \
4981 FN(skc_lookup_tcp), \
4982 FN(tcp_check_syncookie), \
4983 FN(sysctl_get_name), \
4984 FN(sysctl_get_current_value), \
4985 FN(sysctl_get_new_value), \
4986 FN(sysctl_set_new_value), \
4989 FN(sk_storage_get), \
4990 FN(sk_storage_delete), \
4992 FN(tcp_gen_syncookie), \
4994 FN(probe_read_user), \
4995 FN(probe_read_kernel), \
4996 FN(probe_read_user_str), \
4997 FN(probe_read_kernel_str), \
4999 FN(send_signal_thread), \
5001 FN(read_branch_records), \
5002 FN(get_ns_current_pid_tgid), \
5004 FN(get_netns_cookie), \
5005 FN(get_current_ancestor_cgroup_id), \
5007 FN(ktime_get_boot_ns), \
5011 FN(sk_ancestor_cgroup_id), \
5012 FN(ringbuf_output), \
5013 FN(ringbuf_reserve), \
5014 FN(ringbuf_submit), \
5015 FN(ringbuf_discard), \
5016 FN(ringbuf_query), \
5018 FN(skc_to_tcp6_sock), \
5019 FN(skc_to_tcp_sock), \
5020 FN(skc_to_tcp_timewait_sock), \
5021 FN(skc_to_tcp_request_sock), \
5022 FN(skc_to_udp6_sock), \
5023 FN(get_task_stack), \
5025 FN(store_hdr_opt), \
5026 FN(reserve_hdr_opt), \
5027 FN(inode_storage_get), \
5028 FN(inode_storage_delete), \
5030 FN(copy_from_user), \
5032 FN(seq_printf_btf), \
5033 FN(skb_cgroup_classid), \
5034 FN(redirect_neigh), \
5037 FN(redirect_peer), \
5038 FN(task_storage_get), \
5039 FN(task_storage_delete), \
5040 FN(get_current_task_btf), \
5041 FN(bprm_opts_set), \
5042 FN(ktime_get_coarse_ns), \
5043 FN(ima_inode_hash), \
5044 FN(sock_from_file), \
5046 FN(for_each_map_elem), \
5049 FN(btf_find_by_name_kind), \
5052 FN(timer_set_callback), \
5056 FN(get_attach_cookie), \
5060 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
5061 * function eBPF program intends to call
5063 #define __BPF_ENUM_FN(x) BPF_FUNC_ ## x
5065 __BPF_FUNC_MAPPER(__BPF_ENUM_FN)
5068 #undef __BPF_ENUM_FN
5070 /* All flags used by eBPF helper functions, placed here. */
5072 /* BPF_FUNC_skb_store_bytes flags. */
5074 BPF_F_RECOMPUTE_CSUM = (1ULL << 0),
5075 BPF_F_INVALIDATE_HASH = (1ULL << 1),
5078 /* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
5079 * First 4 bits are for passing the header field size.
5082 BPF_F_HDR_FIELD_MASK = 0xfULL,
5085 /* BPF_FUNC_l4_csum_replace flags. */
5087 BPF_F_PSEUDO_HDR = (1ULL << 4),
5088 BPF_F_MARK_MANGLED_0 = (1ULL << 5),
5089 BPF_F_MARK_ENFORCE = (1ULL << 6),
5092 /* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
5094 BPF_F_INGRESS = (1ULL << 0),
5097 /* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
5099 BPF_F_TUNINFO_IPV6 = (1ULL << 0),
5102 /* flags for both BPF_FUNC_get_stackid and BPF_FUNC_get_stack. */
5104 BPF_F_SKIP_FIELD_MASK = 0xffULL,
5105 BPF_F_USER_STACK = (1ULL << 8),
5106 /* flags used by BPF_FUNC_get_stackid only. */
5107 BPF_F_FAST_STACK_CMP = (1ULL << 9),
5108 BPF_F_REUSE_STACKID = (1ULL << 10),
5109 /* flags used by BPF_FUNC_get_stack only. */
5110 BPF_F_USER_BUILD_ID = (1ULL << 11),
5113 /* BPF_FUNC_skb_set_tunnel_key flags. */
5115 BPF_F_ZERO_CSUM_TX = (1ULL << 1),
5116 BPF_F_DONT_FRAGMENT = (1ULL << 2),
5117 BPF_F_SEQ_NUMBER = (1ULL << 3),
5120 /* BPF_FUNC_perf_event_output, BPF_FUNC_perf_event_read and
5121 * BPF_FUNC_perf_event_read_value flags.
5124 BPF_F_INDEX_MASK = 0xffffffffULL,
5125 BPF_F_CURRENT_CPU = BPF_F_INDEX_MASK,
5126 /* BPF_FUNC_perf_event_output for sk_buff input context. */
5127 BPF_F_CTXLEN_MASK = (0xfffffULL << 32),
5130 /* Current network namespace */
5132 BPF_F_CURRENT_NETNS = (-1L),
5135 /* BPF_FUNC_csum_level level values. */
5137 BPF_CSUM_LEVEL_QUERY,
5140 BPF_CSUM_LEVEL_RESET,
5143 /* BPF_FUNC_skb_adjust_room flags. */
5145 BPF_F_ADJ_ROOM_FIXED_GSO = (1ULL << 0),
5146 BPF_F_ADJ_ROOM_ENCAP_L3_IPV4 = (1ULL << 1),
5147 BPF_F_ADJ_ROOM_ENCAP_L3_IPV6 = (1ULL << 2),
5148 BPF_F_ADJ_ROOM_ENCAP_L4_GRE = (1ULL << 3),
5149 BPF_F_ADJ_ROOM_ENCAP_L4_UDP = (1ULL << 4),
5150 BPF_F_ADJ_ROOM_NO_CSUM_RESET = (1ULL << 5),
5151 BPF_F_ADJ_ROOM_ENCAP_L2_ETH = (1ULL << 6),
5155 BPF_ADJ_ROOM_ENCAP_L2_MASK = 0xff,
5156 BPF_ADJ_ROOM_ENCAP_L2_SHIFT = 56,
5159 #define BPF_F_ADJ_ROOM_ENCAP_L2(len) (((__u64)len & \
5160 BPF_ADJ_ROOM_ENCAP_L2_MASK) \
5161 << BPF_ADJ_ROOM_ENCAP_L2_SHIFT)
5163 /* BPF_FUNC_sysctl_get_name flags. */
5165 BPF_F_SYSCTL_BASE_NAME = (1ULL << 0),
5168 /* BPF_FUNC_<kernel_obj>_storage_get flags */
5170 BPF_LOCAL_STORAGE_GET_F_CREATE = (1ULL << 0),
5171 /* BPF_SK_STORAGE_GET_F_CREATE is only kept for backward compatibility
5172 * and BPF_LOCAL_STORAGE_GET_F_CREATE must be used instead.
5174 BPF_SK_STORAGE_GET_F_CREATE = BPF_LOCAL_STORAGE_GET_F_CREATE,
5177 /* BPF_FUNC_read_branch_records flags. */
5179 BPF_F_GET_BRANCH_RECORDS_SIZE = (1ULL << 0),
5182 /* BPF_FUNC_bpf_ringbuf_commit, BPF_FUNC_bpf_ringbuf_discard, and
5183 * BPF_FUNC_bpf_ringbuf_output flags.
5186 BPF_RB_NO_WAKEUP = (1ULL << 0),
5187 BPF_RB_FORCE_WAKEUP = (1ULL << 1),
5190 /* BPF_FUNC_bpf_ringbuf_query flags */
5192 BPF_RB_AVAIL_DATA = 0,
5193 BPF_RB_RING_SIZE = 1,
5194 BPF_RB_CONS_POS = 2,
5195 BPF_RB_PROD_POS = 3,
5198 /* BPF ring buffer constants */
5200 BPF_RINGBUF_BUSY_BIT = (1U << 31),
5201 BPF_RINGBUF_DISCARD_BIT = (1U << 30),
5202 BPF_RINGBUF_HDR_SZ = 8,
5205 /* BPF_FUNC_sk_assign flags in bpf_sk_lookup context. */
5207 BPF_SK_LOOKUP_F_REPLACE = (1ULL << 0),
5208 BPF_SK_LOOKUP_F_NO_REUSEPORT = (1ULL << 1),
5211 /* Mode for BPF_FUNC_skb_adjust_room helper. */
5212 enum bpf_adj_room_mode {
5217 /* Mode for BPF_FUNC_skb_load_bytes_relative helper. */
5218 enum bpf_hdr_start_off {
5223 /* Encapsulation type for BPF_FUNC_lwt_push_encap helper. */
5224 enum bpf_lwt_encap_mode {
5226 BPF_LWT_ENCAP_SEG6_INLINE,
5230 /* Flags for bpf_bprm_opts_set helper */
5232 BPF_F_BPRM_SECUREEXEC = (1ULL << 0),
5235 /* Flags for bpf_redirect_map helper */
5237 BPF_F_BROADCAST = (1ULL << 3),
5238 BPF_F_EXCLUDE_INGRESS = (1ULL << 4),
5241 #define __bpf_md_ptr(type, name) \
5245 } __attribute__((aligned(8)))
5247 /* user accessible mirror of in-kernel sk_buff.
5248 * new fields can only be added to the end of this structure
5254 __u32 queue_mapping;
5260 __u32 ingress_ifindex;
5270 /* Accessed by BPF_PROG_TYPE_sk_skb types from here to ... */
5272 __u32 remote_ip4; /* Stored in network byte order */
5273 __u32 local_ip4; /* Stored in network byte order */
5274 __u32 remote_ip6[4]; /* Stored in network byte order */
5275 __u32 local_ip6[4]; /* Stored in network byte order */
5276 __u32 remote_port; /* Stored in network byte order */
5277 __u32 local_port; /* stored in host byte order */
5281 __bpf_md_ptr(struct bpf_flow_keys *, flow_keys);
5285 __bpf_md_ptr(struct bpf_sock *, sk);
5289 struct bpf_tunnel_key {
5293 __u32 remote_ipv6[4];
5297 __u16 tunnel_ext; /* Padding, future use. */
5301 /* user accessible mirror of in-kernel xfrm_state.
5302 * new fields can only be added to the end of this structure
5304 struct bpf_xfrm_state {
5306 __u32 spi; /* Stored in network byte order */
5308 __u16 ext; /* Padding, future use. */
5310 __u32 remote_ipv4; /* Stored in network byte order */
5311 __u32 remote_ipv6[4]; /* Stored in network byte order */
5315 /* Generic BPF return codes which all BPF program types may support.
5316 * The values are binary compatible with their TC_ACT_* counter-part to
5317 * provide backwards compatibility with existing SCHED_CLS and SCHED_ACT
5320 * XDP is handled seprately, see XDP_*.
5328 /* >127 are reserved for prog type specific return codes.
5330 * BPF_LWT_REROUTE: used by BPF_PROG_TYPE_LWT_IN and
5331 * BPF_PROG_TYPE_LWT_XMIT to indicate that skb had been
5332 * changed and should be routed based on its new L3 header.
5333 * (This is an L3 redirect, as opposed to L2 redirect
5334 * represented by BPF_REDIRECT above).
5336 BPF_LWT_REROUTE = 128,
5346 /* IP address also allows 1 and 2 bytes access */
5349 __u32 src_port; /* host byte order */
5350 __u32 dst_port; /* network byte order */
5354 __s32 rx_queue_mapping;
5357 struct bpf_tcp_sock {
5358 __u32 snd_cwnd; /* Sending congestion window */
5359 __u32 srtt_us; /* smoothed round trip time << 3 in usecs */
5361 __u32 snd_ssthresh; /* Slow start size threshold */
5362 __u32 rcv_nxt; /* What we want to receive next */
5363 __u32 snd_nxt; /* Next sequence we send */
5364 __u32 snd_una; /* First byte we want an ack for */
5365 __u32 mss_cache; /* Cached effective mss, not including SACKS */
5366 __u32 ecn_flags; /* ECN status bits. */
5367 __u32 rate_delivered; /* saved rate sample: packets delivered */
5368 __u32 rate_interval_us; /* saved rate sample: time elapsed */
5369 __u32 packets_out; /* Packets which are "in flight" */
5370 __u32 retrans_out; /* Retransmitted packets out */
5371 __u32 total_retrans; /* Total retransmits for entire connection */
5372 __u32 segs_in; /* RFC4898 tcpEStatsPerfSegsIn
5373 * total number of segments in.
5375 __u32 data_segs_in; /* RFC4898 tcpEStatsPerfDataSegsIn
5376 * total number of data segments in.
5378 __u32 segs_out; /* RFC4898 tcpEStatsPerfSegsOut
5379 * The total number of segments sent.
5381 __u32 data_segs_out; /* RFC4898 tcpEStatsPerfDataSegsOut
5382 * total number of data segments sent.
5384 __u32 lost_out; /* Lost packets */
5385 __u32 sacked_out; /* SACK'd packets */
5386 __u64 bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived
5387 * sum(delta(rcv_nxt)), or how many bytes
5390 __u64 bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked
5391 * sum(delta(snd_una)), or how many bytes
5394 __u32 dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups
5395 * total number of DSACK blocks received
5397 __u32 delivered; /* Total data packets delivered incl. rexmits */
5398 __u32 delivered_ce; /* Like the above but only ECE marked packets */
5399 __u32 icsk_retransmits; /* Number of unrecovered [RTO] timeouts */
5402 struct bpf_sock_tuple {
5419 struct bpf_xdp_sock {
5423 #define XDP_PACKET_HEADROOM 256
5425 /* User return codes for XDP prog type.
5426 * A valid XDP program must return one of these defined values. All other
5427 * return codes are reserved for future use. Unknown return codes will
5428 * result in packet drops and a warning via bpf_warn_invalid_xdp_action().
5438 /* user accessible metadata for XDP packet hook
5439 * new fields must be added to the end of this structure
5445 /* Below access go through struct xdp_rxq_info */
5446 __u32 ingress_ifindex; /* rxq->dev->ifindex */
5447 __u32 rx_queue_index; /* rxq->queue_index */
5449 __u32 egress_ifindex; /* txq->dev->ifindex */
5452 /* DEVMAP map-value layout
5454 * The struct data-layout of map-value is a configuration interface.
5455 * New members can only be added to the end of this structure.
5457 struct bpf_devmap_val {
5458 __u32 ifindex; /* device index */
5460 int fd; /* prog fd on map write */
5461 __u32 id; /* prog id on map read */
5465 /* CPUMAP map-value layout
5467 * The struct data-layout of map-value is a configuration interface.
5468 * New members can only be added to the end of this structure.
5470 struct bpf_cpumap_val {
5471 __u32 qsize; /* queue size to remote target CPU */
5473 int fd; /* prog fd on map write */
5474 __u32 id; /* prog id on map read */
5483 /* user accessible metadata for SK_MSG packet hook, new fields must
5484 * be added to the end of this structure
5487 __bpf_md_ptr(void *, data);
5488 __bpf_md_ptr(void *, data_end);
5491 __u32 remote_ip4; /* Stored in network byte order */
5492 __u32 local_ip4; /* Stored in network byte order */
5493 __u32 remote_ip6[4]; /* Stored in network byte order */
5494 __u32 local_ip6[4]; /* Stored in network byte order */
5495 __u32 remote_port; /* Stored in network byte order */
5496 __u32 local_port; /* stored in host byte order */
5497 __u32 size; /* Total size of sk_msg */
5499 __bpf_md_ptr(struct bpf_sock *, sk); /* current socket */
5502 struct sk_reuseport_md {
5504 * Start of directly accessible data. It begins from
5505 * the tcp/udp header.
5507 __bpf_md_ptr(void *, data);
5508 /* End of directly accessible data */
5509 __bpf_md_ptr(void *, data_end);
5511 * Total length of packet (starting from the tcp/udp header).
5512 * Note that the directly accessible bytes (data_end - data)
5513 * could be less than this "len". Those bytes could be
5514 * indirectly read by a helper "bpf_skb_load_bytes()".
5518 * Eth protocol in the mac header (network byte order). e.g.
5519 * ETH_P_IP(0x0800) and ETH_P_IPV6(0x86DD)
5522 __u32 ip_protocol; /* IP protocol. e.g. IPPROTO_TCP, IPPROTO_UDP */
5523 __u32 bind_inany; /* Is sock bound to an INANY address? */
5524 __u32 hash; /* A hash of the packet 4 tuples */
5525 /* When reuse->migrating_sk is NULL, it is selecting a sk for the
5526 * new incoming connection request (e.g. selecting a listen sk for
5527 * the received SYN in the TCP case). reuse->sk is one of the sk
5528 * in the reuseport group. The bpf prog can use reuse->sk to learn
5529 * the local listening ip/port without looking into the skb.
5531 * When reuse->migrating_sk is not NULL, reuse->sk is closed and
5532 * reuse->migrating_sk is the socket that needs to be migrated
5533 * to another listening socket. migrating_sk could be a fullsock
5534 * sk that is fully established or a reqsk that is in-the-middle
5535 * of 3-way handshake.
5537 __bpf_md_ptr(struct bpf_sock *, sk);
5538 __bpf_md_ptr(struct bpf_sock *, migrating_sk);
5541 #define BPF_TAG_SIZE 8
5543 struct bpf_prog_info {
5546 __u8 tag[BPF_TAG_SIZE];
5547 __u32 jited_prog_len;
5548 __u32 xlated_prog_len;
5549 __aligned_u64 jited_prog_insns;
5550 __aligned_u64 xlated_prog_insns;
5551 __u64 load_time; /* ns since boottime */
5552 __u32 created_by_uid;
5554 __aligned_u64 map_ids;
5555 char name[BPF_OBJ_NAME_LEN];
5557 __u32 gpl_compatible:1;
5558 __u32 :31; /* alignment pad */
5561 __u32 nr_jited_ksyms;
5562 __u32 nr_jited_func_lens;
5563 __aligned_u64 jited_ksyms;
5564 __aligned_u64 jited_func_lens;
5566 __u32 func_info_rec_size;
5567 __aligned_u64 func_info;
5570 __aligned_u64 line_info;
5571 __aligned_u64 jited_line_info;
5572 __u32 nr_jited_line_info;
5573 __u32 line_info_rec_size;
5574 __u32 jited_line_info_rec_size;
5576 __aligned_u64 prog_tags;
5579 __u64 recursion_misses;
5580 } __attribute__((aligned(8)));
5582 struct bpf_map_info {
5589 char name[BPF_OBJ_NAME_LEN];
5591 __u32 btf_vmlinux_value_type_id;
5595 __u32 btf_key_type_id;
5596 __u32 btf_value_type_id;
5597 } __attribute__((aligned(8)));
5599 struct bpf_btf_info {
5606 } __attribute__((aligned(8)));
5608 struct bpf_link_info {
5614 __aligned_u64 tp_name; /* in/out: tp_name buffer ptr */
5615 __u32 tp_name_len; /* in/out: tp_name buffer len */
5619 __u32 target_obj_id; /* prog_id for PROG_EXT, otherwise btf object id */
5620 __u32 target_btf_id; /* BTF type id inside the object */
5627 __aligned_u64 target_name; /* in/out: target_name buffer ptr */
5628 __u32 target_name_len; /* in/out: target_name buffer len */
5643 } __attribute__((aligned(8)));
5645 /* User bpf_sock_addr struct to access socket fields and sockaddr struct passed
5646 * by user and intended to be used by socket (e.g. to bind to, depends on
5649 struct bpf_sock_addr {
5650 __u32 user_family; /* Allows 4-byte read, but no write. */
5651 __u32 user_ip4; /* Allows 1,2,4-byte read and 4-byte write.
5652 * Stored in network byte order.
5654 __u32 user_ip6[4]; /* Allows 1,2,4,8-byte read and 4,8-byte write.
5655 * Stored in network byte order.
5657 __u32 user_port; /* Allows 1,2,4-byte read and 4-byte write.
5658 * Stored in network byte order
5660 __u32 family; /* Allows 4-byte read, but no write */
5661 __u32 type; /* Allows 4-byte read, but no write */
5662 __u32 protocol; /* Allows 4-byte read, but no write */
5663 __u32 msg_src_ip4; /* Allows 1,2,4-byte read and 4-byte write.
5664 * Stored in network byte order.
5666 __u32 msg_src_ip6[4]; /* Allows 1,2,4,8-byte read and 4,8-byte write.
5667 * Stored in network byte order.
5669 __bpf_md_ptr(struct bpf_sock *, sk);
5672 /* User bpf_sock_ops struct to access socket values and specify request ops
5673 * and their replies.
5674 * Some of this fields are in network (bigendian) byte order and may need
5675 * to be converted before use (bpf_ntohl() defined in samples/bpf/bpf_endian.h).
5676 * New fields can only be added at the end of this structure
5678 struct bpf_sock_ops {
5681 __u32 args[4]; /* Optionally passed to bpf program */
5682 __u32 reply; /* Returned by bpf program */
5683 __u32 replylong[4]; /* Optionally returned by bpf prog */
5686 __u32 remote_ip4; /* Stored in network byte order */
5687 __u32 local_ip4; /* Stored in network byte order */
5688 __u32 remote_ip6[4]; /* Stored in network byte order */
5689 __u32 local_ip6[4]; /* Stored in network byte order */
5690 __u32 remote_port; /* Stored in network byte order */
5691 __u32 local_port; /* stored in host byte order */
5692 __u32 is_fullsock; /* Some TCP fields are only valid if
5693 * there is a full socket. If not, the
5694 * fields read as zero.
5697 __u32 srtt_us; /* Averaged RTT << 3 in usecs */
5698 __u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */
5707 __u32 rate_delivered;
5708 __u32 rate_interval_us;
5711 __u32 total_retrans;
5715 __u32 data_segs_out;
5719 __u64 bytes_received;
5721 __bpf_md_ptr(struct bpf_sock *, sk);
5722 /* [skb_data, skb_data_end) covers the whole TCP header.
5724 * BPF_SOCK_OPS_PARSE_HDR_OPT_CB: The packet received
5725 * BPF_SOCK_OPS_HDR_OPT_LEN_CB: Not useful because the
5726 * header has not been written.
5727 * BPF_SOCK_OPS_WRITE_HDR_OPT_CB: The header and options have
5728 * been written so far.
5729 * BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: The SYNACK that concludes
5731 * BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: The ACK that concludes
5734 * bpf_load_hdr_opt() can also be used to read a particular option.
5736 __bpf_md_ptr(void *, skb_data);
5737 __bpf_md_ptr(void *, skb_data_end);
5738 __u32 skb_len; /* The total length of a packet.
5739 * It includes the header, options,
5742 __u32 skb_tcp_flags; /* tcp_flags of the header. It provides
5743 * an easy way to check for tcp_flags
5744 * without parsing skb_data.
5746 * In particular, the skb_tcp_flags
5747 * will still be available in
5748 * BPF_SOCK_OPS_HDR_OPT_LEN even though
5749 * the outgoing header has not
5754 /* Definitions for bpf_sock_ops_cb_flags */
5756 BPF_SOCK_OPS_RTO_CB_FLAG = (1<<0),
5757 BPF_SOCK_OPS_RETRANS_CB_FLAG = (1<<1),
5758 BPF_SOCK_OPS_STATE_CB_FLAG = (1<<2),
5759 BPF_SOCK_OPS_RTT_CB_FLAG = (1<<3),
5760 /* Call bpf for all received TCP headers. The bpf prog will be
5761 * called under sock_ops->op == BPF_SOCK_OPS_PARSE_HDR_OPT_CB
5763 * Please refer to the comment in BPF_SOCK_OPS_PARSE_HDR_OPT_CB
5764 * for the header option related helpers that will be useful
5765 * to the bpf programs.
5767 * It could be used at the client/active side (i.e. connect() side)
5768 * when the server told it that the server was in syncookie
5769 * mode and required the active side to resend the bpf-written
5770 * options. The active side can keep writing the bpf-options until
5771 * it received a valid packet from the server side to confirm
5772 * the earlier packet (and options) has been received. The later
5773 * example patch is using it like this at the active side when the
5774 * server is in syncookie mode.
5776 * The bpf prog will usually turn this off in the common cases.
5778 BPF_SOCK_OPS_PARSE_ALL_HDR_OPT_CB_FLAG = (1<<4),
5779 /* Call bpf when kernel has received a header option that
5780 * the kernel cannot handle. The bpf prog will be called under
5781 * sock_ops->op == BPF_SOCK_OPS_PARSE_HDR_OPT_CB.
5783 * Please refer to the comment in BPF_SOCK_OPS_PARSE_HDR_OPT_CB
5784 * for the header option related helpers that will be useful
5785 * to the bpf programs.
5787 BPF_SOCK_OPS_PARSE_UNKNOWN_HDR_OPT_CB_FLAG = (1<<5),
5788 /* Call bpf when the kernel is writing header options for the
5789 * outgoing packet. The bpf prog will first be called
5790 * to reserve space in a skb under
5791 * sock_ops->op == BPF_SOCK_OPS_HDR_OPT_LEN_CB. Then
5792 * the bpf prog will be called to write the header option(s)
5793 * under sock_ops->op == BPF_SOCK_OPS_WRITE_HDR_OPT_CB.
5795 * Please refer to the comment in BPF_SOCK_OPS_HDR_OPT_LEN_CB
5796 * and BPF_SOCK_OPS_WRITE_HDR_OPT_CB for the header option
5797 * related helpers that will be useful to the bpf programs.
5799 * The kernel gets its chance to reserve space and write
5800 * options first before the BPF program does.
5802 BPF_SOCK_OPS_WRITE_HDR_OPT_CB_FLAG = (1<<6),
5803 /* Mask of all currently supported cb flags */
5804 BPF_SOCK_OPS_ALL_CB_FLAGS = 0x7F,
5807 /* List of known BPF sock_ops operators.
5808 * New entries can only be added at the end
5812 BPF_SOCK_OPS_TIMEOUT_INIT, /* Should return SYN-RTO value to use or
5813 * -1 if default value should be used
5815 BPF_SOCK_OPS_RWND_INIT, /* Should return initial advertized
5816 * window (in packets) or -1 if default
5817 * value should be used
5819 BPF_SOCK_OPS_TCP_CONNECT_CB, /* Calls BPF program right before an
5820 * active connection is initialized
5822 BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB, /* Calls BPF program when an
5823 * active connection is
5826 BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB, /* Calls BPF program when a
5827 * passive connection is
5830 BPF_SOCK_OPS_NEEDS_ECN, /* If connection's congestion control
5833 BPF_SOCK_OPS_BASE_RTT, /* Get base RTT. The correct value is
5834 * based on the path and may be
5835 * dependent on the congestion control
5836 * algorithm. In general it indicates
5837 * a congestion threshold. RTTs above
5838 * this indicate congestion
5840 BPF_SOCK_OPS_RTO_CB, /* Called when an RTO has triggered.
5841 * Arg1: value of icsk_retransmits
5842 * Arg2: value of icsk_rto
5843 * Arg3: whether RTO has expired
5845 BPF_SOCK_OPS_RETRANS_CB, /* Called when skb is retransmitted.
5846 * Arg1: sequence number of 1st byte
5848 * Arg3: return value of
5849 * tcp_transmit_skb (0 => success)
5851 BPF_SOCK_OPS_STATE_CB, /* Called when TCP changes state.
5855 BPF_SOCK_OPS_TCP_LISTEN_CB, /* Called on listen(2), right after
5856 * socket transition to LISTEN state.
5858 BPF_SOCK_OPS_RTT_CB, /* Called on every RTT.
5860 BPF_SOCK_OPS_PARSE_HDR_OPT_CB, /* Parse the header option.
5861 * It will be called to handle
5862 * the packets received at
5863 * an already established
5866 * sock_ops->skb_data:
5867 * Referring to the received skb.
5868 * It covers the TCP header only.
5870 * bpf_load_hdr_opt() can also
5871 * be used to search for a
5872 * particular option.
5874 BPF_SOCK_OPS_HDR_OPT_LEN_CB, /* Reserve space for writing the
5875 * header option later in
5876 * BPF_SOCK_OPS_WRITE_HDR_OPT_CB.
5877 * Arg1: bool want_cookie. (in
5878 * writing SYNACK only)
5880 * sock_ops->skb_data:
5881 * Not available because no header has
5884 * sock_ops->skb_tcp_flags:
5885 * The tcp_flags of the
5886 * outgoing skb. (e.g. SYN, ACK, FIN).
5888 * bpf_reserve_hdr_opt() should
5889 * be used to reserve space.
5891 BPF_SOCK_OPS_WRITE_HDR_OPT_CB, /* Write the header options
5892 * Arg1: bool want_cookie. (in
5893 * writing SYNACK only)
5895 * sock_ops->skb_data:
5896 * Referring to the outgoing skb.
5897 * It covers the TCP header
5898 * that has already been written
5899 * by the kernel and the
5900 * earlier bpf-progs.
5902 * sock_ops->skb_tcp_flags:
5903 * The tcp_flags of the outgoing
5904 * skb. (e.g. SYN, ACK, FIN).
5906 * bpf_store_hdr_opt() should
5907 * be used to write the
5910 * bpf_load_hdr_opt() can also
5911 * be used to search for a
5912 * particular option that
5913 * has already been written
5914 * by the kernel or the
5915 * earlier bpf-progs.
5919 /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
5920 * changes between the TCP and BPF versions. Ideally this should never happen.
5921 * If it does, we need to add code to convert them before calling
5922 * the BPF sock_ops function.
5925 BPF_TCP_ESTABLISHED = 1,
5935 BPF_TCP_CLOSING, /* Now a valid state */
5936 BPF_TCP_NEW_SYN_RECV,
5938 BPF_TCP_MAX_STATES /* Leave at the end! */
5942 TCP_BPF_IW = 1001, /* Set TCP initial congestion window */
5943 TCP_BPF_SNDCWND_CLAMP = 1002, /* Set sndcwnd_clamp */
5944 TCP_BPF_DELACK_MAX = 1003, /* Max delay ack in usecs */
5945 TCP_BPF_RTO_MIN = 1004, /* Min delay ack in usecs */
5946 /* Copy the SYN pkt to optval
5948 * BPF_PROG_TYPE_SOCK_OPS only. It is similar to the
5949 * bpf_getsockopt(TCP_SAVED_SYN) but it does not limit
5950 * to only getting from the saved_syn. It can either get the
5953 * 1. the just-received SYN packet (only available when writing the
5954 * SYNACK). It will be useful when it is not necessary to
5955 * save the SYN packet for latter use. It is also the only way
5956 * to get the SYN during syncookie mode because the syn
5957 * packet cannot be saved during syncookie.
5961 * 2. the earlier saved syn which was done by
5962 * bpf_setsockopt(TCP_SAVE_SYN).
5964 * The bpf_getsockopt(TCP_BPF_SYN*) option will hide where the
5965 * SYN packet is obtained.
5967 * If the bpf-prog does not need the IP[46] header, the
5968 * bpf-prog can avoid parsing the IP header by using
5969 * TCP_BPF_SYN. Otherwise, the bpf-prog can get both
5970 * IP[46] and TCP header by using TCP_BPF_SYN_IP.
5972 * >0: Total number of bytes copied
5973 * -ENOSPC: Not enough space in optval. Only optlen number of
5975 * -ENOENT: The SYN skb is not available now and the earlier SYN pkt
5976 * is not saved by setsockopt(TCP_SAVE_SYN).
5978 TCP_BPF_SYN = 1005, /* Copy the TCP header */
5979 TCP_BPF_SYN_IP = 1006, /* Copy the IP[46] and TCP header */
5980 TCP_BPF_SYN_MAC = 1007, /* Copy the MAC, IP[46], and TCP header */
5984 BPF_LOAD_HDR_OPT_TCP_SYN = (1ULL << 0),
5987 /* args[0] value during BPF_SOCK_OPS_HDR_OPT_LEN_CB and
5988 * BPF_SOCK_OPS_WRITE_HDR_OPT_CB.
5991 BPF_WRITE_HDR_TCP_CURRENT_MSS = 1, /* Kernel is finding the
5992 * total option spaces
5993 * required for an established
5994 * sk in order to calculate the
5995 * MSS. No skb is actually
5998 BPF_WRITE_HDR_TCP_SYNACK_COOKIE = 2, /* Kernel is in syncookie mode
5999 * when sending a SYN.
6003 struct bpf_perf_event_value {
6010 BPF_DEVCG_ACC_MKNOD = (1ULL << 0),
6011 BPF_DEVCG_ACC_READ = (1ULL << 1),
6012 BPF_DEVCG_ACC_WRITE = (1ULL << 2),
6016 BPF_DEVCG_DEV_BLOCK = (1ULL << 0),
6017 BPF_DEVCG_DEV_CHAR = (1ULL << 1),
6020 struct bpf_cgroup_dev_ctx {
6021 /* access_type encoded as (BPF_DEVCG_ACC_* << 16) | BPF_DEVCG_DEV_* */
6027 struct bpf_raw_tracepoint_args {
6031 /* DIRECT: Skip the FIB rules and go to FIB table associated with device
6032 * OUTPUT: Do lookup from egress perspective; default is ingress
6035 BPF_FIB_LOOKUP_DIRECT = (1U << 0),
6036 BPF_FIB_LOOKUP_OUTPUT = (1U << 1),
6040 BPF_FIB_LKUP_RET_SUCCESS, /* lookup successful */
6041 BPF_FIB_LKUP_RET_BLACKHOLE, /* dest is blackholed; can be dropped */
6042 BPF_FIB_LKUP_RET_UNREACHABLE, /* dest is unreachable; can be dropped */
6043 BPF_FIB_LKUP_RET_PROHIBIT, /* dest not allowed; can be dropped */
6044 BPF_FIB_LKUP_RET_NOT_FWDED, /* packet is not forwarded */
6045 BPF_FIB_LKUP_RET_FWD_DISABLED, /* fwding is not enabled on ingress */
6046 BPF_FIB_LKUP_RET_UNSUPP_LWT, /* fwd requires encapsulation */
6047 BPF_FIB_LKUP_RET_NO_NEIGH, /* no neighbor entry for nh */
6048 BPF_FIB_LKUP_RET_FRAG_NEEDED, /* fragmentation required to fwd */
6051 struct bpf_fib_lookup {
6052 /* input: network family for lookup (AF_INET, AF_INET6)
6053 * output: network family of egress nexthop
6057 /* set if lookup is to consider L4 data - e.g., FIB rules */
6062 union { /* used for MTU check */
6063 /* input to lookup */
6064 __u16 tot_len; /* L3 length from network hdr (iph->tot_len) */
6066 /* output: MTU value */
6069 /* input: L3 device index for lookup
6070 * output: device index from FIB lookup
6075 /* inputs to lookup */
6076 __u8 tos; /* AF_INET */
6077 __be32 flowinfo; /* AF_INET6, flow_label + priority */
6079 /* output: metric of fib result (IPv4/IPv6 only) */
6085 __u32 ipv6_src[4]; /* in6_addr; network order */
6088 /* input to bpf_fib_lookup, ipv{4,6}_dst is destination address in
6089 * network header. output: bpf_fib_lookup sets to gateway address
6090 * if FIB lookup returns gateway route
6094 __u32 ipv6_dst[4]; /* in6_addr; network order */
6098 __be16 h_vlan_proto;
6100 __u8 smac[6]; /* ETH_ALEN */
6101 __u8 dmac[6]; /* ETH_ALEN */
6104 struct bpf_redir_neigh {
6105 /* network family for lookup (AF_INET, AF_INET6) */
6107 /* network address of nexthop; skips fib lookup to find gateway */
6110 __u32 ipv6_nh[4]; /* in6_addr; network order */
6114 /* bpf_check_mtu flags*/
6115 enum bpf_check_mtu_flags {
6116 BPF_MTU_CHK_SEGS = (1U << 0),
6119 enum bpf_check_mtu_ret {
6120 BPF_MTU_CHK_RET_SUCCESS, /* check and lookup successful */
6121 BPF_MTU_CHK_RET_FRAG_NEEDED, /* fragmentation required to fwd */
6122 BPF_MTU_CHK_RET_SEGS_TOOBIG, /* GSO re-segmentation needed to fwd */
6125 enum bpf_task_fd_type {
6126 BPF_FD_TYPE_RAW_TRACEPOINT, /* tp name */
6127 BPF_FD_TYPE_TRACEPOINT, /* tp name */
6128 BPF_FD_TYPE_KPROBE, /* (symbol + offset) or addr */
6129 BPF_FD_TYPE_KRETPROBE, /* (symbol + offset) or addr */
6130 BPF_FD_TYPE_UPROBE, /* filename + offset */
6131 BPF_FD_TYPE_URETPROBE, /* filename + offset */
6135 BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG = (1U << 0),
6136 BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL = (1U << 1),
6137 BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP = (1U << 2),
6140 struct bpf_flow_keys {
6143 __u16 addr_proto; /* ETH_P_* of valid addrs */
6157 __u32 ipv6_src[4]; /* in6_addr; network order */
6158 __u32 ipv6_dst[4]; /* in6_addr; network order */
6165 struct bpf_func_info {
6170 #define BPF_LINE_INFO_LINE_NUM(line_col) ((line_col) >> 10)
6171 #define BPF_LINE_INFO_LINE_COL(line_col) ((line_col) & 0x3ff)
6173 struct bpf_line_info {
6175 __u32 file_name_off;
6180 struct bpf_spin_lock {
6187 } __attribute__((aligned(8)));
6190 __u32 write; /* Sysctl is being read (= 0) or written (= 1).
6191 * Allows 1,2,4-byte read, but no write.
6193 __u32 file_pos; /* Sysctl file position to read from, write to.
6194 * Allows 1,2,4-byte read an 4-byte write.
6198 struct bpf_sockopt {
6199 __bpf_md_ptr(struct bpf_sock *, sk);
6200 __bpf_md_ptr(void *, optval);
6201 __bpf_md_ptr(void *, optval_end);
6209 struct bpf_pidns_info {
6214 /* User accessible data for SK_LOOKUP programs. Add new fields at the end. */
6215 struct bpf_sk_lookup {
6217 __bpf_md_ptr(struct bpf_sock *, sk); /* Selected socket */
6218 __u64 cookie; /* Non-zero if socket was selected in PROG_TEST_RUN */
6221 __u32 family; /* Protocol family (AF_INET, AF_INET6) */
6222 __u32 protocol; /* IP protocol (IPPROTO_TCP, IPPROTO_UDP) */
6223 __u32 remote_ip4; /* Network byte order */
6224 __u32 remote_ip6[4]; /* Network byte order */
6225 __u32 remote_port; /* Network byte order */
6226 __u32 local_ip4; /* Network byte order */
6227 __u32 local_ip6[4]; /* Network byte order */
6228 __u32 local_port; /* Host byte order */
6232 * struct btf_ptr is used for typed pointer representation; the
6233 * type id is used to render the pointer data as the appropriate type
6234 * via the bpf_snprintf_btf() helper described above. A flags field -
6235 * potentially to specify additional details about the BTF pointer
6236 * (rather than its mode of display) - is included for future use.
6237 * Display flags - BTF_F_* - are passed to bpf_snprintf_btf separately.
6242 __u32 flags; /* BTF ptr flags; unused at present. */
6246 * Flags to control bpf_snprintf_btf() behaviour.
6247 * - BTF_F_COMPACT: no formatting around type information
6248 * - BTF_F_NONAME: no struct/union member names/types
6249 * - BTF_F_PTR_RAW: show raw (unobfuscated) pointer values;
6250 * equivalent to %px.
6251 * - BTF_F_ZERO: show zero-valued struct/union members; they
6252 * are not displayed by default
6255 BTF_F_COMPACT = (1ULL << 0),
6256 BTF_F_NONAME = (1ULL << 1),
6257 BTF_F_PTR_RAW = (1ULL << 2),
6258 BTF_F_ZERO = (1ULL << 3),
6261 #endif /* _UAPI__LINUX_BPF_H__ */
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