1 /* SPDX-License-Identifier: GPL-2.0-or-later */
3 * Definitions for the 'struct sk_buff' memory handlers.
6 * Alan Cox, <gw4pts@gw4pts.ampr.org>
7 * Florian La Roche, <rzsfl@rz.uni-sb.de>
10 #ifndef _LINUX_SKBUFF_H
11 #define _LINUX_SKBUFF_H
13 #include <linux/kernel.h>
14 #include <linux/compiler.h>
15 #include <linux/time.h>
16 #include <linux/bug.h>
17 #include <linux/bvec.h>
18 #include <linux/cache.h>
19 #include <linux/rbtree.h>
20 #include <linux/socket.h>
21 #include <linux/refcount.h>
23 #include <linux/atomic.h>
24 #include <asm/types.h>
25 #include <linux/spinlock.h>
26 #include <net/checksum.h>
27 #include <linux/rcupdate.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/netdev_features.h>
30 #include <net/flow_dissector.h>
31 #include <linux/in6.h>
32 #include <linux/if_packet.h>
33 #include <linux/llist.h>
35 #include <net/page_pool.h>
36 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
37 #include <linux/netfilter/nf_conntrack_common.h>
39 #include <net/net_debug.h>
40 #include <net/dropreason.h>
45 * The interface for checksum offload between the stack and networking drivers
48 * IP checksum related features
49 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
51 * Drivers advertise checksum offload capabilities in the features of a device.
52 * From the stack's point of view these are capabilities offered by the driver.
53 * A driver typically only advertises features that it is capable of offloading
56 * .. flat-table:: Checksum related device features
59 * * - %NETIF_F_HW_CSUM
60 * - The driver (or its device) is able to compute one
61 * IP (one's complement) checksum for any combination
62 * of protocols or protocol layering. The checksum is
63 * computed and set in a packet per the CHECKSUM_PARTIAL
64 * interface (see below).
66 * * - %NETIF_F_IP_CSUM
67 * - Driver (device) is only able to checksum plain
68 * TCP or UDP packets over IPv4. These are specifically
69 * unencapsulated packets of the form IPv4|TCP or
70 * IPv4|UDP where the Protocol field in the IPv4 header
71 * is TCP or UDP. The IPv4 header may contain IP options.
72 * This feature cannot be set in features for a device
73 * with NETIF_F_HW_CSUM also set. This feature is being
74 * DEPRECATED (see below).
76 * * - %NETIF_F_IPV6_CSUM
77 * - Driver (device) is only able to checksum plain
78 * TCP or UDP packets over IPv6. These are specifically
79 * unencapsulated packets of the form IPv6|TCP or
80 * IPv6|UDP where the Next Header field in the IPv6
81 * header is either TCP or UDP. IPv6 extension headers
82 * are not supported with this feature. This feature
83 * cannot be set in features for a device with
84 * NETIF_F_HW_CSUM also set. This feature is being
85 * DEPRECATED (see below).
88 * - Driver (device) performs receive checksum offload.
89 * This flag is only used to disable the RX checksum
90 * feature for a device. The stack will accept receive
91 * checksum indication in packets received on a device
92 * regardless of whether NETIF_F_RXCSUM is set.
94 * Checksumming of received packets by device
95 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
97 * Indication of checksum verification is set in &sk_buff.ip_summed.
98 * Possible values are:
102 * Device did not checksum this packet e.g. due to lack of capabilities.
103 * The packet contains full (though not verified) checksum in packet but
104 * not in skb->csum. Thus, skb->csum is undefined in this case.
106 * - %CHECKSUM_UNNECESSARY
108 * The hardware you're dealing with doesn't calculate the full checksum
109 * (as in %CHECKSUM_COMPLETE), but it does parse headers and verify checksums
110 * for specific protocols. For such packets it will set %CHECKSUM_UNNECESSARY
111 * if their checksums are okay. &sk_buff.csum is still undefined in this case
112 * though. A driver or device must never modify the checksum field in the
113 * packet even if checksum is verified.
115 * %CHECKSUM_UNNECESSARY is applicable to following protocols:
117 * - TCP: IPv6 and IPv4.
118 * - UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
119 * zero UDP checksum for either IPv4 or IPv6, the networking stack
120 * may perform further validation in this case.
121 * - GRE: only if the checksum is present in the header.
122 * - SCTP: indicates the CRC in SCTP header has been validated.
123 * - FCOE: indicates the CRC in FC frame has been validated.
125 * &sk_buff.csum_level indicates the number of consecutive checksums found in
126 * the packet minus one that have been verified as %CHECKSUM_UNNECESSARY.
127 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
128 * and a device is able to verify the checksums for UDP (possibly zero),
129 * GRE (checksum flag is set) and TCP, &sk_buff.csum_level would be set to
130 * two. If the device were only able to verify the UDP checksum and not
131 * GRE, either because it doesn't support GRE checksum or because GRE
132 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
133 * not considered in this case).
135 * - %CHECKSUM_COMPLETE
137 * This is the most generic way. The device supplied checksum of the _whole_
138 * packet as seen by netif_rx() and fills in &sk_buff.csum. This means the
139 * hardware doesn't need to parse L3/L4 headers to implement this.
143 * - Even if device supports only some protocols, but is able to produce
144 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
145 * - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols.
147 * - %CHECKSUM_PARTIAL
149 * A checksum is set up to be offloaded to a device as described in the
150 * output description for CHECKSUM_PARTIAL. This may occur on a packet
151 * received directly from another Linux OS, e.g., a virtualized Linux kernel
152 * on the same host, or it may be set in the input path in GRO or remote
153 * checksum offload. For the purposes of checksum verification, the checksum
154 * referred to by skb->csum_start + skb->csum_offset and any preceding
155 * checksums in the packet are considered verified. Any checksums in the
156 * packet that are after the checksum being offloaded are not considered to
159 * Checksumming on transmit for non-GSO
160 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
162 * The stack requests checksum offload in the &sk_buff.ip_summed for a packet.
165 * - %CHECKSUM_PARTIAL
167 * The driver is required to checksum the packet as seen by hard_start_xmit()
168 * from &sk_buff.csum_start up to the end, and to record/write the checksum at
169 * offset &sk_buff.csum_start + &sk_buff.csum_offset.
170 * A driver may verify that the
171 * csum_start and csum_offset values are valid values given the length and
172 * offset of the packet, but it should not attempt to validate that the
173 * checksum refers to a legitimate transport layer checksum -- it is the
174 * purview of the stack to validate that csum_start and csum_offset are set
177 * When the stack requests checksum offload for a packet, the driver MUST
178 * ensure that the checksum is set correctly. A driver can either offload the
179 * checksum calculation to the device, or call skb_checksum_help (in the case
180 * that the device does not support offload for a particular checksum).
182 * %NETIF_F_IP_CSUM and %NETIF_F_IPV6_CSUM are being deprecated in favor of
183 * %NETIF_F_HW_CSUM. New devices should use %NETIF_F_HW_CSUM to indicate
184 * checksum offload capability.
185 * skb_csum_hwoffload_help() can be called to resolve %CHECKSUM_PARTIAL based
186 * on network device checksumming capabilities: if a packet does not match
187 * them, skb_checksum_help() or skb_crc32c_help() (depending on the value of
188 * &sk_buff.csum_not_inet, see :ref:`crc`)
189 * is called to resolve the checksum.
193 * The skb was already checksummed by the protocol, or a checksum is not
196 * - %CHECKSUM_UNNECESSARY
198 * This has the same meaning as CHECKSUM_NONE for checksum offload on
201 * - %CHECKSUM_COMPLETE
203 * Not used in checksum output. If a driver observes a packet with this value
204 * set in skbuff, it should treat the packet as if %CHECKSUM_NONE were set.
208 * Non-IP checksum (CRC) offloads
209 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
214 * * - %NETIF_F_SCTP_CRC
215 * - This feature indicates that a device is capable of
216 * offloading the SCTP CRC in a packet. To perform this offload the stack
217 * will set csum_start and csum_offset accordingly, set ip_summed to
218 * %CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication
219 * in the skbuff that the %CHECKSUM_PARTIAL refers to CRC32c.
220 * A driver that supports both IP checksum offload and SCTP CRC32c offload
221 * must verify which offload is configured for a packet by testing the
222 * value of &sk_buff.csum_not_inet; skb_crc32c_csum_help() is provided to
223 * resolve %CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1.
225 * * - %NETIF_F_FCOE_CRC
226 * - This feature indicates that a device is capable of offloading the FCOE
227 * CRC in a packet. To perform this offload the stack will set ip_summed
228 * to %CHECKSUM_PARTIAL and set csum_start and csum_offset
229 * accordingly. Note that there is no indication in the skbuff that the
230 * %CHECKSUM_PARTIAL refers to an FCOE checksum, so a driver that supports
231 * both IP checksum offload and FCOE CRC offload must verify which offload
232 * is configured for a packet, presumably by inspecting packet headers.
234 * Checksumming on output with GSO
235 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
237 * In the case of a GSO packet (skb_is_gso() is true), checksum offload
238 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
239 * gso_type is %SKB_GSO_TCPV4 or %SKB_GSO_TCPV6, TCP checksum offload as
240 * part of the GSO operation is implied. If a checksum is being offloaded
241 * with GSO then ip_summed is %CHECKSUM_PARTIAL, and both csum_start and
242 * csum_offset are set to refer to the outermost checksum being offloaded
243 * (two offloaded checksums are possible with UDP encapsulation).
246 /* Don't change this without changing skb_csum_unnecessary! */
247 #define CHECKSUM_NONE 0
248 #define CHECKSUM_UNNECESSARY 1
249 #define CHECKSUM_COMPLETE 2
250 #define CHECKSUM_PARTIAL 3
252 /* Maximum value in skb->csum_level */
253 #define SKB_MAX_CSUM_LEVEL 3
255 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
256 #define SKB_WITH_OVERHEAD(X) \
257 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
258 #define SKB_MAX_ORDER(X, ORDER) \
259 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
260 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
261 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
263 /* return minimum truesize of one skb containing X bytes of data */
264 #define SKB_TRUESIZE(X) ((X) + \
265 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
266 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
268 struct ahash_request;
271 struct pipe_inode_info;
279 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
280 struct nf_bridge_info {
282 BRNF_PROTO_UNCHANGED,
290 struct net_device *physindev;
292 /* always valid & non-NULL from FORWARD on, for physdev match */
293 struct net_device *physoutdev;
295 /* prerouting: detect dnat in orig/reply direction */
297 struct in6_addr ipv6_daddr;
299 /* after prerouting + nat detected: store original source
300 * mac since neigh resolution overwrites it, only used while
301 * skb is out in neigh layer.
303 char neigh_header[8];
308 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
309 /* Chain in tc_skb_ext will be used to share the tc chain with
310 * ovs recirc_id. It will be set to the current chain by tc
311 * and read by ovs to recirc_id.
323 struct sk_buff_head {
324 /* These two members must be first to match sk_buff. */
325 struct_group_tagged(sk_buff_list, list,
326 struct sk_buff *next;
327 struct sk_buff *prev;
336 /* To allow 64K frame to be packed as single skb without frag_list we
337 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
338 * buffers which do not start on a page boundary.
340 * Since GRO uses frags we allocate at least 16 regardless of page
343 #if (65536/PAGE_SIZE + 1) < 16
344 #define MAX_SKB_FRAGS 16UL
346 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
348 extern int sysctl_max_skb_frags;
350 /* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to
351 * segment using its current segmentation instead.
353 #define GSO_BY_FRAGS 0xFFFF
355 typedef struct bio_vec skb_frag_t;
358 * skb_frag_size() - Returns the size of a skb fragment
359 * @frag: skb fragment
361 static inline unsigned int skb_frag_size(const skb_frag_t *frag)
367 * skb_frag_size_set() - Sets the size of a skb fragment
368 * @frag: skb fragment
369 * @size: size of fragment
371 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
377 * skb_frag_size_add() - Increments the size of a skb fragment by @delta
378 * @frag: skb fragment
379 * @delta: value to add
381 static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
383 frag->bv_len += delta;
387 * skb_frag_size_sub() - Decrements the size of a skb fragment by @delta
388 * @frag: skb fragment
389 * @delta: value to subtract
391 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
393 frag->bv_len -= delta;
397 * skb_frag_must_loop - Test if %p is a high memory page
398 * @p: fragment's page
400 static inline bool skb_frag_must_loop(struct page *p)
402 #if defined(CONFIG_HIGHMEM)
403 if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) || PageHighMem(p))
410 * skb_frag_foreach_page - loop over pages in a fragment
412 * @f: skb frag to operate on
413 * @f_off: offset from start of f->bv_page
414 * @f_len: length from f_off to loop over
415 * @p: (temp var) current page
416 * @p_off: (temp var) offset from start of current page,
417 * non-zero only on first page.
418 * @p_len: (temp var) length in current page,
419 * < PAGE_SIZE only on first and last page.
420 * @copied: (temp var) length so far, excluding current p_len.
422 * A fragment can hold a compound page, in which case per-page
423 * operations, notably kmap_atomic, must be called for each
426 #define skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied) \
427 for (p = skb_frag_page(f) + ((f_off) >> PAGE_SHIFT), \
428 p_off = (f_off) & (PAGE_SIZE - 1), \
429 p_len = skb_frag_must_loop(p) ? \
430 min_t(u32, f_len, PAGE_SIZE - p_off) : f_len, \
433 copied += p_len, p++, p_off = 0, \
434 p_len = min_t(u32, f_len - copied, PAGE_SIZE)) \
436 #define HAVE_HW_TIME_STAMP
439 * struct skb_shared_hwtstamps - hardware time stamps
440 * @hwtstamp: hardware time stamp transformed into duration
441 * since arbitrary point in time
442 * @netdev_data: address/cookie of network device driver used as
443 * reference to actual hardware time stamp
445 * Software time stamps generated by ktime_get_real() are stored in
448 * hwtstamps can only be compared against other hwtstamps from
451 * This structure is attached to packets as part of the
452 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
454 struct skb_shared_hwtstamps {
461 /* Definitions for tx_flags in struct skb_shared_info */
463 /* generate hardware time stamp */
464 SKBTX_HW_TSTAMP = 1 << 0,
466 /* generate software time stamp when queueing packet to NIC */
467 SKBTX_SW_TSTAMP = 1 << 1,
469 /* device driver is going to provide hardware time stamp */
470 SKBTX_IN_PROGRESS = 1 << 2,
472 /* generate hardware time stamp based on cycles if supported */
473 SKBTX_HW_TSTAMP_USE_CYCLES = 1 << 3,
475 /* generate wifi status information (where possible) */
476 SKBTX_WIFI_STATUS = 1 << 4,
478 /* determine hardware time stamp based on time or cycles */
479 SKBTX_HW_TSTAMP_NETDEV = 1 << 5,
481 /* generate software time stamp when entering packet scheduling */
482 SKBTX_SCHED_TSTAMP = 1 << 6,
485 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
487 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | \
488 SKBTX_HW_TSTAMP_USE_CYCLES | \
491 /* Definitions for flags in struct skb_shared_info */
493 /* use zcopy routines */
494 SKBFL_ZEROCOPY_ENABLE = BIT(0),
496 /* This indicates at least one fragment might be overwritten
497 * (as in vmsplice(), sendfile() ...)
498 * If we need to compute a TX checksum, we'll need to copy
499 * all frags to avoid possible bad checksum
501 SKBFL_SHARED_FRAG = BIT(1),
503 /* segment contains only zerocopy data and should not be
504 * charged to the kernel memory.
506 SKBFL_PURE_ZEROCOPY = BIT(2),
508 SKBFL_DONT_ORPHAN = BIT(3),
510 /* page references are managed by the ubuf_info, so it's safe to
511 * use frags only up until ubuf_info is released
513 SKBFL_MANAGED_FRAG_REFS = BIT(4),
516 #define SKBFL_ZEROCOPY_FRAG (SKBFL_ZEROCOPY_ENABLE | SKBFL_SHARED_FRAG)
517 #define SKBFL_ALL_ZEROCOPY (SKBFL_ZEROCOPY_FRAG | SKBFL_PURE_ZEROCOPY | \
518 SKBFL_DONT_ORPHAN | SKBFL_MANAGED_FRAG_REFS)
521 * The callback notifies userspace to release buffers when skb DMA is done in
522 * lower device, the skb last reference should be 0 when calling this.
523 * The zerocopy_success argument is true if zero copy transmit occurred,
524 * false on data copy or out of memory error caused by data copy attempt.
525 * The ctx field is used to track device context.
526 * The desc field is used to track userspace buffer index.
529 void (*callback)(struct sk_buff *, struct ubuf_info *,
530 bool zerocopy_success);
535 struct ubuf_info_msgzc {
536 struct ubuf_info ubuf;
552 struct user_struct *user;
557 #define skb_uarg(SKB) ((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg))
558 #define uarg_to_msgzc(ubuf_ptr) container_of((ubuf_ptr), struct ubuf_info_msgzc, \
561 int mm_account_pinned_pages(struct mmpin *mmp, size_t size);
562 void mm_unaccount_pinned_pages(struct mmpin *mmp);
564 /* This data is invariant across clones and lives at
565 * the end of the header data, ie. at skb->end.
567 struct skb_shared_info {
572 unsigned short gso_size;
573 /* Warning: this field is not always filled in (UFO)! */
574 unsigned short gso_segs;
575 struct sk_buff *frag_list;
576 struct skb_shared_hwtstamps hwtstamps;
577 unsigned int gso_type;
581 * Warning : all fields before dataref are cleared in __alloc_skb()
584 unsigned int xdp_frags_size;
586 /* Intermediate layers must ensure that destructor_arg
587 * remains valid until skb destructor */
588 void * destructor_arg;
590 /* must be last field, see pskb_expand_head() */
591 skb_frag_t frags[MAX_SKB_FRAGS];
595 * DOC: dataref and headerless skbs
597 * Transport layers send out clones of payload skbs they hold for
598 * retransmissions. To allow lower layers of the stack to prepend their headers
599 * we split &skb_shared_info.dataref into two halves.
600 * The lower 16 bits count the overall number of references.
601 * The higher 16 bits indicate how many of the references are payload-only.
602 * skb_header_cloned() checks if skb is allowed to add / write the headers.
604 * The creator of the skb (e.g. TCP) marks its skb as &sk_buff.nohdr
605 * (via __skb_header_release()). Any clone created from marked skb will get
606 * &sk_buff.hdr_len populated with the available headroom.
607 * If there's the only clone in existence it's able to modify the headroom
608 * at will. The sequence of calls inside the transport layer is::
612 * __skb_header_release()
614 * // send the clone down the stack
616 * This is not a very generic construct and it depends on the transport layers
617 * doing the right thing. In practice there's usually only one payload-only skb.
618 * Having multiple payload-only skbs with different lengths of hdr_len is not
619 * possible. The payload-only skbs should never leave their owner.
621 #define SKB_DATAREF_SHIFT 16
622 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
626 SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */
627 SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */
628 SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */
632 SKB_GSO_TCPV4 = 1 << 0,
634 /* This indicates the skb is from an untrusted source. */
635 SKB_GSO_DODGY = 1 << 1,
637 /* This indicates the tcp segment has CWR set. */
638 SKB_GSO_TCP_ECN = 1 << 2,
640 SKB_GSO_TCP_FIXEDID = 1 << 3,
642 SKB_GSO_TCPV6 = 1 << 4,
644 SKB_GSO_FCOE = 1 << 5,
646 SKB_GSO_GRE = 1 << 6,
648 SKB_GSO_GRE_CSUM = 1 << 7,
650 SKB_GSO_IPXIP4 = 1 << 8,
652 SKB_GSO_IPXIP6 = 1 << 9,
654 SKB_GSO_UDP_TUNNEL = 1 << 10,
656 SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
658 SKB_GSO_PARTIAL = 1 << 12,
660 SKB_GSO_TUNNEL_REMCSUM = 1 << 13,
662 SKB_GSO_SCTP = 1 << 14,
664 SKB_GSO_ESP = 1 << 15,
666 SKB_GSO_UDP = 1 << 16,
668 SKB_GSO_UDP_L4 = 1 << 17,
670 SKB_GSO_FRAGLIST = 1 << 18,
673 #if BITS_PER_LONG > 32
674 #define NET_SKBUFF_DATA_USES_OFFSET 1
677 #ifdef NET_SKBUFF_DATA_USES_OFFSET
678 typedef unsigned int sk_buff_data_t;
680 typedef unsigned char *sk_buff_data_t;
684 * DOC: Basic sk_buff geometry
686 * struct sk_buff itself is a metadata structure and does not hold any packet
687 * data. All the data is held in associated buffers.
689 * &sk_buff.head points to the main "head" buffer. The head buffer is divided
692 * - data buffer, containing headers and sometimes payload;
693 * this is the part of the skb operated on by the common helpers
694 * such as skb_put() or skb_pull();
695 * - shared info (struct skb_shared_info) which holds an array of pointers
696 * to read-only data in the (page, offset, length) format.
698 * Optionally &skb_shared_info.frag_list may point to another skb.
700 * Basic diagram may look like this::
705 * ,--------------------------- + head
706 * / ,----------------- + data
707 * / / ,----------- + tail
711 * -----------------------------------------------
712 * | headroom | data | tailroom | skb_shared_info |
713 * -----------------------------------------------
717 * + [page frag] ---------
718 * + frag_list --> | sk_buff |
724 * struct sk_buff - socket buffer
725 * @next: Next buffer in list
726 * @prev: Previous buffer in list
727 * @tstamp: Time we arrived/left
728 * @skb_mstamp_ns: (aka @tstamp) earliest departure time; start point
729 * for retransmit timer
730 * @rbnode: RB tree node, alternative to next/prev for netem/tcp
732 * @ll_node: anchor in an llist (eg socket defer_list)
733 * @sk: Socket we are owned by
734 * @ip_defrag_offset: (aka @sk) alternate use of @sk, used in
735 * fragmentation management
736 * @dev: Device we arrived on/are leaving by
737 * @dev_scratch: (aka @dev) alternate use of @dev when @dev would be %NULL
738 * @cb: Control buffer. Free for use by every layer. Put private vars here
739 * @_skb_refdst: destination entry (with norefcount bit)
740 * @sp: the security path, used for xfrm
741 * @len: Length of actual data
742 * @data_len: Data length
743 * @mac_len: Length of link layer header
744 * @hdr_len: writable header length of cloned skb
745 * @csum: Checksum (must include start/offset pair)
746 * @csum_start: Offset from skb->head where checksumming should start
747 * @csum_offset: Offset from csum_start where checksum should be stored
748 * @priority: Packet queueing priority
749 * @ignore_df: allow local fragmentation
750 * @cloned: Head may be cloned (check refcnt to be sure)
751 * @ip_summed: Driver fed us an IP checksum
752 * @nohdr: Payload reference only, must not modify header
753 * @pkt_type: Packet class
754 * @fclone: skbuff clone status
755 * @ipvs_property: skbuff is owned by ipvs
756 * @inner_protocol_type: whether the inner protocol is
757 * ENCAP_TYPE_ETHER or ENCAP_TYPE_IPPROTO
758 * @remcsum_offload: remote checksum offload is enabled
759 * @offload_fwd_mark: Packet was L2-forwarded in hardware
760 * @offload_l3_fwd_mark: Packet was L3-forwarded in hardware
761 * @tc_skip_classify: do not classify packet. set by IFB device
762 * @tc_at_ingress: used within tc_classify to distinguish in/egress
763 * @redirected: packet was redirected by packet classifier
764 * @from_ingress: packet was redirected from the ingress path
765 * @nf_skip_egress: packet shall skip nf egress - see netfilter_netdev.h
766 * @peeked: this packet has been seen already, so stats have been
767 * done for it, don't do them again
768 * @nf_trace: netfilter packet trace flag
769 * @protocol: Packet protocol from driver
770 * @destructor: Destruct function
771 * @tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue)
772 * @_sk_redir: socket redirection information for skmsg
773 * @_nfct: Associated connection, if any (with nfctinfo bits)
774 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
775 * @skb_iif: ifindex of device we arrived on
776 * @tc_index: Traffic control index
777 * @hash: the packet hash
778 * @queue_mapping: Queue mapping for multiqueue devices
779 * @head_frag: skb was allocated from page fragments,
780 * not allocated by kmalloc() or vmalloc().
781 * @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves
782 * @pp_recycle: mark the packet for recycling instead of freeing (implies
783 * page_pool support on driver)
784 * @active_extensions: active extensions (skb_ext_id types)
785 * @ndisc_nodetype: router type (from link layer)
786 * @ooo_okay: allow the mapping of a socket to a queue to be changed
787 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
789 * @sw_hash: indicates hash was computed in software stack
790 * @wifi_acked_valid: wifi_acked was set
791 * @wifi_acked: whether frame was acked on wifi or not
792 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
793 * @encapsulation: indicates the inner headers in the skbuff are valid
794 * @encap_hdr_csum: software checksum is needed
795 * @csum_valid: checksum is already valid
796 * @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL
797 * @csum_complete_sw: checksum was completed by software
798 * @csum_level: indicates the number of consecutive checksums found in
799 * the packet minus one that have been verified as
800 * CHECKSUM_UNNECESSARY (max 3)
801 * @scm_io_uring: SKB holds io_uring registered files
802 * @dst_pending_confirm: need to confirm neighbour
803 * @decrypted: Decrypted SKB
804 * @slow_gro: state present at GRO time, slower prepare step required
805 * @mono_delivery_time: When set, skb->tstamp has the
806 * delivery_time in mono clock base (i.e. EDT). Otherwise, the
807 * skb->tstamp has the (rcv) timestamp at ingress and
808 * delivery_time at egress.
809 * @napi_id: id of the NAPI struct this skb came from
810 * @sender_cpu: (aka @napi_id) source CPU in XPS
811 * @alloc_cpu: CPU which did the skb allocation.
812 * @secmark: security marking
813 * @mark: Generic packet mark
814 * @reserved_tailroom: (aka @mark) number of bytes of free space available
815 * at the tail of an sk_buff
816 * @vlan_all: vlan fields (proto & tci)
817 * @vlan_proto: vlan encapsulation protocol
818 * @vlan_tci: vlan tag control information
819 * @inner_protocol: Protocol (encapsulation)
820 * @inner_ipproto: (aka @inner_protocol) stores ipproto when
821 * skb->inner_protocol_type == ENCAP_TYPE_IPPROTO;
822 * @inner_transport_header: Inner transport layer header (encapsulation)
823 * @inner_network_header: Network layer header (encapsulation)
824 * @inner_mac_header: Link layer header (encapsulation)
825 * @transport_header: Transport layer header
826 * @network_header: Network layer header
827 * @mac_header: Link layer header
828 * @kcov_handle: KCOV remote handle for remote coverage collection
829 * @tail: Tail pointer
831 * @head: Head of buffer
832 * @data: Data head pointer
833 * @truesize: Buffer size
834 * @users: User count - see {datagram,tcp}.c
835 * @extensions: allocated extensions, valid if active_extensions is nonzero
841 /* These two members must be first to match sk_buff_head. */
842 struct sk_buff *next;
843 struct sk_buff *prev;
846 struct net_device *dev;
847 /* Some protocols might use this space to store information,
848 * while device pointer would be NULL.
849 * UDP receive path is one user.
851 unsigned long dev_scratch;
854 struct rb_node rbnode; /* used in netem, ip4 defrag, and tcp stack */
855 struct list_head list;
856 struct llist_node ll_node;
861 int ip_defrag_offset;
866 u64 skb_mstamp_ns; /* earliest departure time */
869 * This is the control buffer. It is free to use for every
870 * layer. Please put your private variables there. If you
871 * want to keep them across layers you have to do a skb_clone()
872 * first. This is owned by whoever has the skb queued ATM.
874 char cb[48] __aligned(8);
878 unsigned long _skb_refdst;
879 void (*destructor)(struct sk_buff *skb);
881 struct list_head tcp_tsorted_anchor;
882 #ifdef CONFIG_NET_SOCK_MSG
883 unsigned long _sk_redir;
887 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
895 /* Following fields are _not_ copied in __copy_skb_header()
896 * Note that queue_mapping is here mostly to fill a hole.
900 /* if you move cloned around you also must adapt those constants */
901 #ifdef __BIG_ENDIAN_BITFIELD
902 #define CLONED_MASK (1 << 7)
904 #define CLONED_MASK 1
906 #define CLONED_OFFSET offsetof(struct sk_buff, __cloned_offset)
909 __u8 __cloned_offset[0];
917 pp_recycle:1; /* page_pool recycle indicator */
918 #ifdef CONFIG_SKB_EXTENSIONS
919 __u8 active_extensions;
922 /* Fields enclosed in headers group are copied
923 * using a single memcpy() in __copy_skb_header()
925 struct_group(headers,
928 __u8 __pkt_type_offset[0];
930 __u8 pkt_type:3; /* see PKT_TYPE_MAX */
938 __u8 wifi_acked_valid:1;
941 /* Indicates the inner headers are valid in the skbuff. */
942 __u8 encapsulation:1;
943 __u8 encap_hdr_csum:1;
947 __u8 __pkt_vlan_present_offset[0];
949 __u8 remcsum_offload:1;
950 __u8 csum_complete_sw:1;
952 __u8 dst_pending_confirm:1;
953 __u8 mono_delivery_time:1; /* See SKB_MONO_DELIVERY_TIME_MASK */
954 #ifdef CONFIG_NET_CLS_ACT
955 __u8 tc_skip_classify:1;
956 __u8 tc_at_ingress:1; /* See TC_AT_INGRESS_MASK */
958 #ifdef CONFIG_IPV6_NDISC_NODETYPE
959 __u8 ndisc_nodetype:2;
962 __u8 ipvs_property:1;
963 __u8 inner_protocol_type:1;
964 #ifdef CONFIG_NET_SWITCHDEV
965 __u8 offload_fwd_mark:1;
966 __u8 offload_l3_fwd_mark:1;
969 #ifdef CONFIG_NET_REDIRECT
972 #ifdef CONFIG_NETFILTER_SKIP_EGRESS
973 __u8 nf_skip_egress:1;
975 #ifdef CONFIG_TLS_DEVICE
979 __u8 csum_not_inet:1;
982 #ifdef CONFIG_NET_SCHED
983 __u16 tc_index; /* traffic control index */
1003 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
1005 unsigned int napi_id;
1006 unsigned int sender_cpu;
1010 #ifdef CONFIG_NETWORK_SECMARK
1016 __u32 reserved_tailroom;
1020 __be16 inner_protocol;
1024 __u16 inner_transport_header;
1025 __u16 inner_network_header;
1026 __u16 inner_mac_header;
1029 __u16 transport_header;
1030 __u16 network_header;
1037 ); /* end headers group */
1039 /* These elements must be at the end, see alloc_skb() for details. */
1040 sk_buff_data_t tail;
1042 unsigned char *head,
1044 unsigned int truesize;
1047 #ifdef CONFIG_SKB_EXTENSIONS
1048 /* only useable after checking ->active_extensions != 0 */
1049 struct skb_ext *extensions;
1053 /* if you move pkt_type around you also must adapt those constants */
1054 #ifdef __BIG_ENDIAN_BITFIELD
1055 #define PKT_TYPE_MAX (7 << 5)
1057 #define PKT_TYPE_MAX 7
1059 #define PKT_TYPE_OFFSET offsetof(struct sk_buff, __pkt_type_offset)
1061 /* if you move tc_at_ingress or mono_delivery_time
1062 * around, you also must adapt these constants.
1064 #ifdef __BIG_ENDIAN_BITFIELD
1065 #define TC_AT_INGRESS_MASK (1 << 0)
1066 #define SKB_MONO_DELIVERY_TIME_MASK (1 << 2)
1068 #define TC_AT_INGRESS_MASK (1 << 7)
1069 #define SKB_MONO_DELIVERY_TIME_MASK (1 << 5)
1071 #define PKT_VLAN_PRESENT_OFFSET offsetof(struct sk_buff, __pkt_vlan_present_offset)
1075 * Handling routines are only of interest to the kernel
1078 #define SKB_ALLOC_FCLONE 0x01
1079 #define SKB_ALLOC_RX 0x02
1080 #define SKB_ALLOC_NAPI 0x04
1083 * skb_pfmemalloc - Test if the skb was allocated from PFMEMALLOC reserves
1086 static inline bool skb_pfmemalloc(const struct sk_buff *skb)
1088 return unlikely(skb->pfmemalloc);
1092 * skb might have a dst pointer attached, refcounted or not.
1093 * _skb_refdst low order bit is set if refcount was _not_ taken
1095 #define SKB_DST_NOREF 1UL
1096 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
1099 * skb_dst - returns skb dst_entry
1102 * Returns skb dst_entry, regardless of reference taken or not.
1104 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
1106 /* If refdst was not refcounted, check we still are in a
1107 * rcu_read_lock section
1109 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
1110 !rcu_read_lock_held() &&
1111 !rcu_read_lock_bh_held());
1112 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
1116 * skb_dst_set - sets skb dst
1120 * Sets skb dst, assuming a reference was taken on dst and should
1121 * be released by skb_dst_drop()
1123 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
1125 skb->slow_gro |= !!dst;
1126 skb->_skb_refdst = (unsigned long)dst;
1130 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
1134 * Sets skb dst, assuming a reference was not taken on dst.
1135 * If dst entry is cached, we do not take reference and dst_release
1136 * will be avoided by refdst_drop. If dst entry is not cached, we take
1137 * reference, so that last dst_release can destroy the dst immediately.
1139 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst)
1141 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
1142 skb->slow_gro |= !!dst;
1143 skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF;
1147 * skb_dst_is_noref - Test if skb dst isn't refcounted
1150 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
1152 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
1156 * skb_rtable - Returns the skb &rtable
1159 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
1161 return (struct rtable *)skb_dst(skb);
1164 /* For mangling skb->pkt_type from user space side from applications
1165 * such as nft, tc, etc, we only allow a conservative subset of
1166 * possible pkt_types to be set.
1168 static inline bool skb_pkt_type_ok(u32 ptype)
1170 return ptype <= PACKET_OTHERHOST;
1174 * skb_napi_id - Returns the skb's NAPI id
1177 static inline unsigned int skb_napi_id(const struct sk_buff *skb)
1179 #ifdef CONFIG_NET_RX_BUSY_POLL
1180 return skb->napi_id;
1187 * skb_unref - decrement the skb's reference count
1190 * Returns true if we can free the skb.
1192 static inline bool skb_unref(struct sk_buff *skb)
1196 if (likely(refcount_read(&skb->users) == 1))
1198 else if (likely(!refcount_dec_and_test(&skb->users)))
1205 kfree_skb_reason(struct sk_buff *skb, enum skb_drop_reason reason);
1208 * kfree_skb - free an sk_buff with 'NOT_SPECIFIED' reason
1209 * @skb: buffer to free
1211 static inline void kfree_skb(struct sk_buff *skb)
1213 kfree_skb_reason(skb, SKB_DROP_REASON_NOT_SPECIFIED);
1216 void skb_release_head_state(struct sk_buff *skb);
1217 void kfree_skb_list_reason(struct sk_buff *segs,
1218 enum skb_drop_reason reason);
1219 void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt);
1220 void skb_tx_error(struct sk_buff *skb);
1222 static inline void kfree_skb_list(struct sk_buff *segs)
1224 kfree_skb_list_reason(segs, SKB_DROP_REASON_NOT_SPECIFIED);
1227 #ifdef CONFIG_TRACEPOINTS
1228 void consume_skb(struct sk_buff *skb);
1230 static inline void consume_skb(struct sk_buff *skb)
1232 return kfree_skb(skb);
1236 void __consume_stateless_skb(struct sk_buff *skb);
1237 void __kfree_skb(struct sk_buff *skb);
1238 extern struct kmem_cache *skbuff_head_cache;
1240 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
1241 bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
1242 bool *fragstolen, int *delta_truesize);
1244 struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags,
1246 struct sk_buff *__build_skb(void *data, unsigned int frag_size);
1247 struct sk_buff *build_skb(void *data, unsigned int frag_size);
1248 struct sk_buff *build_skb_around(struct sk_buff *skb,
1249 void *data, unsigned int frag_size);
1250 void skb_attempt_defer_free(struct sk_buff *skb);
1252 struct sk_buff *napi_build_skb(void *data, unsigned int frag_size);
1253 struct sk_buff *slab_build_skb(void *data);
1256 * alloc_skb - allocate a network buffer
1257 * @size: size to allocate
1258 * @priority: allocation mask
1260 * This function is a convenient wrapper around __alloc_skb().
1262 static inline struct sk_buff *alloc_skb(unsigned int size,
1265 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
1268 struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
1269 unsigned long data_len,
1273 struct sk_buff *alloc_skb_for_msg(struct sk_buff *first);
1275 /* Layout of fast clones : [skb1][skb2][fclone_ref] */
1276 struct sk_buff_fclones {
1277 struct sk_buff skb1;
1279 struct sk_buff skb2;
1281 refcount_t fclone_ref;
1285 * skb_fclone_busy - check if fclone is busy
1289 * Returns true if skb is a fast clone, and its clone is not freed.
1290 * Some drivers call skb_orphan() in their ndo_start_xmit(),
1291 * so we also check that this didnt happen.
1293 static inline bool skb_fclone_busy(const struct sock *sk,
1294 const struct sk_buff *skb)
1296 const struct sk_buff_fclones *fclones;
1298 fclones = container_of(skb, struct sk_buff_fclones, skb1);
1300 return skb->fclone == SKB_FCLONE_ORIG &&
1301 refcount_read(&fclones->fclone_ref) > 1 &&
1302 READ_ONCE(fclones->skb2.sk) == sk;
1306 * alloc_skb_fclone - allocate a network buffer from fclone cache
1307 * @size: size to allocate
1308 * @priority: allocation mask
1310 * This function is a convenient wrapper around __alloc_skb().
1312 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
1315 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
1318 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
1319 void skb_headers_offset_update(struct sk_buff *skb, int off);
1320 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
1321 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority);
1322 void skb_copy_header(struct sk_buff *new, const struct sk_buff *old);
1323 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority);
1324 struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
1325 gfp_t gfp_mask, bool fclone);
1326 static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom,
1329 return __pskb_copy_fclone(skb, headroom, gfp_mask, false);
1332 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask);
1333 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
1334 unsigned int headroom);
1335 struct sk_buff *skb_expand_head(struct sk_buff *skb, unsigned int headroom);
1336 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom,
1337 int newtailroom, gfp_t priority);
1338 int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
1339 int offset, int len);
1340 int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg,
1341 int offset, int len);
1342 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
1343 int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error);
1346 * skb_pad - zero pad the tail of an skb
1347 * @skb: buffer to pad
1348 * @pad: space to pad
1350 * Ensure that a buffer is followed by a padding area that is zero
1351 * filled. Used by network drivers which may DMA or transfer data
1352 * beyond the buffer end onto the wire.
1354 * May return error in out of memory cases. The skb is freed on error.
1356 static inline int skb_pad(struct sk_buff *skb, int pad)
1358 return __skb_pad(skb, pad, true);
1360 #define dev_kfree_skb(a) consume_skb(a)
1362 int skb_append_pagefrags(struct sk_buff *skb, struct page *page,
1363 int offset, size_t size);
1365 struct skb_seq_state {
1369 __u32 stepped_offset;
1370 struct sk_buff *root_skb;
1371 struct sk_buff *cur_skb;
1376 void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
1377 unsigned int to, struct skb_seq_state *st);
1378 unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
1379 struct skb_seq_state *st);
1380 void skb_abort_seq_read(struct skb_seq_state *st);
1382 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
1383 unsigned int to, struct ts_config *config);
1386 * Packet hash types specify the type of hash in skb_set_hash.
1388 * Hash types refer to the protocol layer addresses which are used to
1389 * construct a packet's hash. The hashes are used to differentiate or identify
1390 * flows of the protocol layer for the hash type. Hash types are either
1391 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
1393 * Properties of hashes:
1395 * 1) Two packets in different flows have different hash values
1396 * 2) Two packets in the same flow should have the same hash value
1398 * A hash at a higher layer is considered to be more specific. A driver should
1399 * set the most specific hash possible.
1401 * A driver cannot indicate a more specific hash than the layer at which a hash
1402 * was computed. For instance an L3 hash cannot be set as an L4 hash.
1404 * A driver may indicate a hash level which is less specific than the
1405 * actual layer the hash was computed on. For instance, a hash computed
1406 * at L4 may be considered an L3 hash. This should only be done if the
1407 * driver can't unambiguously determine that the HW computed the hash at
1408 * the higher layer. Note that the "should" in the second property above
1411 enum pkt_hash_types {
1412 PKT_HASH_TYPE_NONE, /* Undefined type */
1413 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */
1414 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */
1415 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */
1418 static inline void skb_clear_hash(struct sk_buff *skb)
1425 static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
1428 skb_clear_hash(skb);
1432 __skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4)
1434 skb->l4_hash = is_l4;
1435 skb->sw_hash = is_sw;
1440 skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
1442 /* Used by drivers to set hash from HW */
1443 __skb_set_hash(skb, hash, false, type == PKT_HASH_TYPE_L4);
1447 __skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4)
1449 __skb_set_hash(skb, hash, true, is_l4);
1452 void __skb_get_hash(struct sk_buff *skb);
1453 u32 __skb_get_hash_symmetric(const struct sk_buff *skb);
1454 u32 skb_get_poff(const struct sk_buff *skb);
1455 u32 __skb_get_poff(const struct sk_buff *skb, const void *data,
1456 const struct flow_keys_basic *keys, int hlen);
1457 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
1458 const void *data, int hlen_proto);
1460 static inline __be32 skb_flow_get_ports(const struct sk_buff *skb,
1461 int thoff, u8 ip_proto)
1463 return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, 0);
1466 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
1467 const struct flow_dissector_key *key,
1468 unsigned int key_count);
1470 struct bpf_flow_dissector;
1471 u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
1472 __be16 proto, int nhoff, int hlen, unsigned int flags);
1474 bool __skb_flow_dissect(const struct net *net,
1475 const struct sk_buff *skb,
1476 struct flow_dissector *flow_dissector,
1477 void *target_container, const void *data,
1478 __be16 proto, int nhoff, int hlen, unsigned int flags);
1480 static inline bool skb_flow_dissect(const struct sk_buff *skb,
1481 struct flow_dissector *flow_dissector,
1482 void *target_container, unsigned int flags)
1484 return __skb_flow_dissect(NULL, skb, flow_dissector,
1485 target_container, NULL, 0, 0, 0, flags);
1488 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb,
1489 struct flow_keys *flow,
1492 memset(flow, 0, sizeof(*flow));
1493 return __skb_flow_dissect(NULL, skb, &flow_keys_dissector,
1494 flow, NULL, 0, 0, 0, flags);
1498 skb_flow_dissect_flow_keys_basic(const struct net *net,
1499 const struct sk_buff *skb,
1500 struct flow_keys_basic *flow,
1501 const void *data, __be16 proto,
1502 int nhoff, int hlen, unsigned int flags)
1504 memset(flow, 0, sizeof(*flow));
1505 return __skb_flow_dissect(net, skb, &flow_keys_basic_dissector, flow,
1506 data, proto, nhoff, hlen, flags);
1509 void skb_flow_dissect_meta(const struct sk_buff *skb,
1510 struct flow_dissector *flow_dissector,
1511 void *target_container);
1513 /* Gets a skb connection tracking info, ctinfo map should be a
1514 * map of mapsize to translate enum ip_conntrack_info states
1518 skb_flow_dissect_ct(const struct sk_buff *skb,
1519 struct flow_dissector *flow_dissector,
1520 void *target_container,
1521 u16 *ctinfo_map, size_t mapsize,
1522 bool post_ct, u16 zone);
1524 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
1525 struct flow_dissector *flow_dissector,
1526 void *target_container);
1528 void skb_flow_dissect_hash(const struct sk_buff *skb,
1529 struct flow_dissector *flow_dissector,
1530 void *target_container);
1532 static inline __u32 skb_get_hash(struct sk_buff *skb)
1534 if (!skb->l4_hash && !skb->sw_hash)
1535 __skb_get_hash(skb);
1540 static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
1542 if (!skb->l4_hash && !skb->sw_hash) {
1543 struct flow_keys keys;
1544 __u32 hash = __get_hash_from_flowi6(fl6, &keys);
1546 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1552 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1553 const siphash_key_t *perturb);
1555 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb)
1560 static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
1562 to->hash = from->hash;
1563 to->sw_hash = from->sw_hash;
1564 to->l4_hash = from->l4_hash;
1567 static inline void skb_copy_decrypted(struct sk_buff *to,
1568 const struct sk_buff *from)
1570 #ifdef CONFIG_TLS_DEVICE
1571 to->decrypted = from->decrypted;
1575 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1576 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1578 return skb->head + skb->end;
1581 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1586 static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset)
1591 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1596 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1598 return skb->end - skb->head;
1601 static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset)
1603 skb->end = skb->head + offset;
1607 struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size,
1608 struct ubuf_info *uarg);
1610 void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref);
1612 void msg_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *uarg,
1615 int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk,
1616 struct sk_buff *skb, struct iov_iter *from,
1619 static inline int skb_zerocopy_iter_dgram(struct sk_buff *skb,
1620 struct msghdr *msg, int len)
1622 return __zerocopy_sg_from_iter(msg, skb->sk, skb, &msg->msg_iter, len);
1625 int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
1626 struct msghdr *msg, int len,
1627 struct ubuf_info *uarg);
1630 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
1632 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
1634 return &skb_shinfo(skb)->hwtstamps;
1637 static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb)
1639 bool is_zcopy = skb && skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE;
1641 return is_zcopy ? skb_uarg(skb) : NULL;
1644 static inline bool skb_zcopy_pure(const struct sk_buff *skb)
1646 return skb_shinfo(skb)->flags & SKBFL_PURE_ZEROCOPY;
1649 static inline bool skb_zcopy_managed(const struct sk_buff *skb)
1651 return skb_shinfo(skb)->flags & SKBFL_MANAGED_FRAG_REFS;
1654 static inline bool skb_pure_zcopy_same(const struct sk_buff *skb1,
1655 const struct sk_buff *skb2)
1657 return skb_zcopy_pure(skb1) == skb_zcopy_pure(skb2);
1660 static inline void net_zcopy_get(struct ubuf_info *uarg)
1662 refcount_inc(&uarg->refcnt);
1665 static inline void skb_zcopy_init(struct sk_buff *skb, struct ubuf_info *uarg)
1667 skb_shinfo(skb)->destructor_arg = uarg;
1668 skb_shinfo(skb)->flags |= uarg->flags;
1671 static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg,
1674 if (skb && uarg && !skb_zcopy(skb)) {
1675 if (unlikely(have_ref && *have_ref))
1678 net_zcopy_get(uarg);
1679 skb_zcopy_init(skb, uarg);
1683 static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val)
1685 skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL);
1686 skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;
1689 static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb)
1691 return (uintptr_t) skb_shinfo(skb)->destructor_arg & 0x1UL;
1694 static inline void *skb_zcopy_get_nouarg(struct sk_buff *skb)
1696 return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~0x1UL);
1699 static inline void net_zcopy_put(struct ubuf_info *uarg)
1702 uarg->callback(NULL, uarg, true);
1705 static inline void net_zcopy_put_abort(struct ubuf_info *uarg, bool have_uref)
1708 if (uarg->callback == msg_zerocopy_callback)
1709 msg_zerocopy_put_abort(uarg, have_uref);
1711 net_zcopy_put(uarg);
1715 /* Release a reference on a zerocopy structure */
1716 static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success)
1718 struct ubuf_info *uarg = skb_zcopy(skb);
1721 if (!skb_zcopy_is_nouarg(skb))
1722 uarg->callback(skb, uarg, zerocopy_success);
1724 skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY;
1728 void __skb_zcopy_downgrade_managed(struct sk_buff *skb);
1730 static inline void skb_zcopy_downgrade_managed(struct sk_buff *skb)
1732 if (unlikely(skb_zcopy_managed(skb)))
1733 __skb_zcopy_downgrade_managed(skb);
1736 static inline void skb_mark_not_on_list(struct sk_buff *skb)
1741 static inline void skb_poison_list(struct sk_buff *skb)
1743 #ifdef CONFIG_DEBUG_NET
1744 skb->next = SKB_LIST_POISON_NEXT;
1748 /* Iterate through singly-linked GSO fragments of an skb. */
1749 #define skb_list_walk_safe(first, skb, next_skb) \
1750 for ((skb) = (first), (next_skb) = (skb) ? (skb)->next : NULL; (skb); \
1751 (skb) = (next_skb), (next_skb) = (skb) ? (skb)->next : NULL)
1753 static inline void skb_list_del_init(struct sk_buff *skb)
1755 __list_del_entry(&skb->list);
1756 skb_mark_not_on_list(skb);
1760 * skb_queue_empty - check if a queue is empty
1763 * Returns true if the queue is empty, false otherwise.
1765 static inline int skb_queue_empty(const struct sk_buff_head *list)
1767 return list->next == (const struct sk_buff *) list;
1771 * skb_queue_empty_lockless - check if a queue is empty
1774 * Returns true if the queue is empty, false otherwise.
1775 * This variant can be used in lockless contexts.
1777 static inline bool skb_queue_empty_lockless(const struct sk_buff_head *list)
1779 return READ_ONCE(list->next) == (const struct sk_buff *) list;
1784 * skb_queue_is_last - check if skb is the last entry in the queue
1788 * Returns true if @skb is the last buffer on the list.
1790 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
1791 const struct sk_buff *skb)
1793 return skb->next == (const struct sk_buff *) list;
1797 * skb_queue_is_first - check if skb is the first entry in the queue
1801 * Returns true if @skb is the first buffer on the list.
1803 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
1804 const struct sk_buff *skb)
1806 return skb->prev == (const struct sk_buff *) list;
1810 * skb_queue_next - return the next packet in the queue
1812 * @skb: current buffer
1814 * Return the next packet in @list after @skb. It is only valid to
1815 * call this if skb_queue_is_last() evaluates to false.
1817 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
1818 const struct sk_buff *skb)
1820 /* This BUG_ON may seem severe, but if we just return then we
1821 * are going to dereference garbage.
1823 BUG_ON(skb_queue_is_last(list, skb));
1828 * skb_queue_prev - return the prev packet in the queue
1830 * @skb: current buffer
1832 * Return the prev packet in @list before @skb. It is only valid to
1833 * call this if skb_queue_is_first() evaluates to false.
1835 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
1836 const struct sk_buff *skb)
1838 /* This BUG_ON may seem severe, but if we just return then we
1839 * are going to dereference garbage.
1841 BUG_ON(skb_queue_is_first(list, skb));
1846 * skb_get - reference buffer
1847 * @skb: buffer to reference
1849 * Makes another reference to a socket buffer and returns a pointer
1852 static inline struct sk_buff *skb_get(struct sk_buff *skb)
1854 refcount_inc(&skb->users);
1859 * If users == 1, we are the only owner and can avoid redundant atomic changes.
1863 * skb_cloned - is the buffer a clone
1864 * @skb: buffer to check
1866 * Returns true if the buffer was generated with skb_clone() and is
1867 * one of multiple shared copies of the buffer. Cloned buffers are
1868 * shared data so must not be written to under normal circumstances.
1870 static inline int skb_cloned(const struct sk_buff *skb)
1872 return skb->cloned &&
1873 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
1876 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
1878 might_sleep_if(gfpflags_allow_blocking(pri));
1880 if (skb_cloned(skb))
1881 return pskb_expand_head(skb, 0, 0, pri);
1886 /* This variant of skb_unclone() makes sure skb->truesize
1887 * and skb_end_offset() are not changed, whenever a new skb->head is needed.
1889 * Indeed there is no guarantee that ksize(kmalloc(X)) == ksize(kmalloc(X))
1890 * when various debugging features are in place.
1892 int __skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri);
1893 static inline int skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri)
1895 might_sleep_if(gfpflags_allow_blocking(pri));
1897 if (skb_cloned(skb))
1898 return __skb_unclone_keeptruesize(skb, pri);
1903 * skb_header_cloned - is the header a clone
1904 * @skb: buffer to check
1906 * Returns true if modifying the header part of the buffer requires
1907 * the data to be copied.
1909 static inline int skb_header_cloned(const struct sk_buff *skb)
1916 dataref = atomic_read(&skb_shinfo(skb)->dataref);
1917 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
1918 return dataref != 1;
1921 static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri)
1923 might_sleep_if(gfpflags_allow_blocking(pri));
1925 if (skb_header_cloned(skb))
1926 return pskb_expand_head(skb, 0, 0, pri);
1932 * __skb_header_release() - allow clones to use the headroom
1933 * @skb: buffer to operate on
1935 * See "DOC: dataref and headerless skbs".
1937 static inline void __skb_header_release(struct sk_buff *skb)
1940 atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT));
1945 * skb_shared - is the buffer shared
1946 * @skb: buffer to check
1948 * Returns true if more than one person has a reference to this
1951 static inline int skb_shared(const struct sk_buff *skb)
1953 return refcount_read(&skb->users) != 1;
1957 * skb_share_check - check if buffer is shared and if so clone it
1958 * @skb: buffer to check
1959 * @pri: priority for memory allocation
1961 * If the buffer is shared the buffer is cloned and the old copy
1962 * drops a reference. A new clone with a single reference is returned.
1963 * If the buffer is not shared the original buffer is returned. When
1964 * being called from interrupt status or with spinlocks held pri must
1967 * NULL is returned on a memory allocation failure.
1969 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
1971 might_sleep_if(gfpflags_allow_blocking(pri));
1972 if (skb_shared(skb)) {
1973 struct sk_buff *nskb = skb_clone(skb, pri);
1985 * Copy shared buffers into a new sk_buff. We effectively do COW on
1986 * packets to handle cases where we have a local reader and forward
1987 * and a couple of other messy ones. The normal one is tcpdumping
1988 * a packet thats being forwarded.
1992 * skb_unshare - make a copy of a shared buffer
1993 * @skb: buffer to check
1994 * @pri: priority for memory allocation
1996 * If the socket buffer is a clone then this function creates a new
1997 * copy of the data, drops a reference count on the old copy and returns
1998 * the new copy with the reference count at 1. If the buffer is not a clone
1999 * the original buffer is returned. When called with a spinlock held or
2000 * from interrupt state @pri must be %GFP_ATOMIC
2002 * %NULL is returned on a memory allocation failure.
2004 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
2007 might_sleep_if(gfpflags_allow_blocking(pri));
2008 if (skb_cloned(skb)) {
2009 struct sk_buff *nskb = skb_copy(skb, pri);
2011 /* Free our shared copy */
2022 * skb_peek - peek at the head of an &sk_buff_head
2023 * @list_: list to peek at
2025 * Peek an &sk_buff. Unlike most other operations you _MUST_
2026 * be careful with this one. A peek leaves the buffer on the
2027 * list and someone else may run off with it. You must hold
2028 * the appropriate locks or have a private queue to do this.
2030 * Returns %NULL for an empty list or a pointer to the head element.
2031 * The reference count is not incremented and the reference is therefore
2032 * volatile. Use with caution.
2034 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
2036 struct sk_buff *skb = list_->next;
2038 if (skb == (struct sk_buff *)list_)
2044 * __skb_peek - peek at the head of a non-empty &sk_buff_head
2045 * @list_: list to peek at
2047 * Like skb_peek(), but the caller knows that the list is not empty.
2049 static inline struct sk_buff *__skb_peek(const struct sk_buff_head *list_)
2055 * skb_peek_next - peek skb following the given one from a queue
2056 * @skb: skb to start from
2057 * @list_: list to peek at
2059 * Returns %NULL when the end of the list is met or a pointer to the
2060 * next element. The reference count is not incremented and the
2061 * reference is therefore volatile. Use with caution.
2063 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
2064 const struct sk_buff_head *list_)
2066 struct sk_buff *next = skb->next;
2068 if (next == (struct sk_buff *)list_)
2074 * skb_peek_tail - peek at the tail of an &sk_buff_head
2075 * @list_: list to peek at
2077 * Peek an &sk_buff. Unlike most other operations you _MUST_
2078 * be careful with this one. A peek leaves the buffer on the
2079 * list and someone else may run off with it. You must hold
2080 * the appropriate locks or have a private queue to do this.
2082 * Returns %NULL for an empty list or a pointer to the tail element.
2083 * The reference count is not incremented and the reference is therefore
2084 * volatile. Use with caution.
2086 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
2088 struct sk_buff *skb = READ_ONCE(list_->prev);
2090 if (skb == (struct sk_buff *)list_)
2097 * skb_queue_len - get queue length
2098 * @list_: list to measure
2100 * Return the length of an &sk_buff queue.
2102 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
2108 * skb_queue_len_lockless - get queue length
2109 * @list_: list to measure
2111 * Return the length of an &sk_buff queue.
2112 * This variant can be used in lockless contexts.
2114 static inline __u32 skb_queue_len_lockless(const struct sk_buff_head *list_)
2116 return READ_ONCE(list_->qlen);
2120 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
2121 * @list: queue to initialize
2123 * This initializes only the list and queue length aspects of
2124 * an sk_buff_head object. This allows to initialize the list
2125 * aspects of an sk_buff_head without reinitializing things like
2126 * the spinlock. It can also be used for on-stack sk_buff_head
2127 * objects where the spinlock is known to not be used.
2129 static inline void __skb_queue_head_init(struct sk_buff_head *list)
2131 list->prev = list->next = (struct sk_buff *)list;
2136 * This function creates a split out lock class for each invocation;
2137 * this is needed for now since a whole lot of users of the skb-queue
2138 * infrastructure in drivers have different locking usage (in hardirq)
2139 * than the networking core (in softirq only). In the long run either the
2140 * network layer or drivers should need annotation to consolidate the
2141 * main types of usage into 3 classes.
2143 static inline void skb_queue_head_init(struct sk_buff_head *list)
2145 spin_lock_init(&list->lock);
2146 __skb_queue_head_init(list);
2149 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
2150 struct lock_class_key *class)
2152 skb_queue_head_init(list);
2153 lockdep_set_class(&list->lock, class);
2157 * Insert an sk_buff on a list.
2159 * The "__skb_xxxx()" functions are the non-atomic ones that
2160 * can only be called with interrupts disabled.
2162 static inline void __skb_insert(struct sk_buff *newsk,
2163 struct sk_buff *prev, struct sk_buff *next,
2164 struct sk_buff_head *list)
2166 /* See skb_queue_empty_lockless() and skb_peek_tail()
2167 * for the opposite READ_ONCE()
2169 WRITE_ONCE(newsk->next, next);
2170 WRITE_ONCE(newsk->prev, prev);
2171 WRITE_ONCE(((struct sk_buff_list *)next)->prev, newsk);
2172 WRITE_ONCE(((struct sk_buff_list *)prev)->next, newsk);
2173 WRITE_ONCE(list->qlen, list->qlen + 1);
2176 static inline void __skb_queue_splice(const struct sk_buff_head *list,
2177 struct sk_buff *prev,
2178 struct sk_buff *next)
2180 struct sk_buff *first = list->next;
2181 struct sk_buff *last = list->prev;
2183 WRITE_ONCE(first->prev, prev);
2184 WRITE_ONCE(prev->next, first);
2186 WRITE_ONCE(last->next, next);
2187 WRITE_ONCE(next->prev, last);
2191 * skb_queue_splice - join two skb lists, this is designed for stacks
2192 * @list: the new list to add
2193 * @head: the place to add it in the first list
2195 static inline void skb_queue_splice(const struct sk_buff_head *list,
2196 struct sk_buff_head *head)
2198 if (!skb_queue_empty(list)) {
2199 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
2200 head->qlen += list->qlen;
2205 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
2206 * @list: the new list to add
2207 * @head: the place to add it in the first list
2209 * The list at @list is reinitialised
2211 static inline void skb_queue_splice_init(struct sk_buff_head *list,
2212 struct sk_buff_head *head)
2214 if (!skb_queue_empty(list)) {
2215 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
2216 head->qlen += list->qlen;
2217 __skb_queue_head_init(list);
2222 * skb_queue_splice_tail - join two skb lists, each list being a queue
2223 * @list: the new list to add
2224 * @head: the place to add it in the first list
2226 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
2227 struct sk_buff_head *head)
2229 if (!skb_queue_empty(list)) {
2230 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
2231 head->qlen += list->qlen;
2236 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
2237 * @list: the new list to add
2238 * @head: the place to add it in the first list
2240 * Each of the lists is a queue.
2241 * The list at @list is reinitialised
2243 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
2244 struct sk_buff_head *head)
2246 if (!skb_queue_empty(list)) {
2247 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
2248 head->qlen += list->qlen;
2249 __skb_queue_head_init(list);
2254 * __skb_queue_after - queue a buffer at the list head
2255 * @list: list to use
2256 * @prev: place after this buffer
2257 * @newsk: buffer to queue
2259 * Queue a buffer int the middle of a list. This function takes no locks
2260 * and you must therefore hold required locks before calling it.
2262 * A buffer cannot be placed on two lists at the same time.
2264 static inline void __skb_queue_after(struct sk_buff_head *list,
2265 struct sk_buff *prev,
2266 struct sk_buff *newsk)
2268 __skb_insert(newsk, prev, ((struct sk_buff_list *)prev)->next, list);
2271 void skb_append(struct sk_buff *old, struct sk_buff *newsk,
2272 struct sk_buff_head *list);
2274 static inline void __skb_queue_before(struct sk_buff_head *list,
2275 struct sk_buff *next,
2276 struct sk_buff *newsk)
2278 __skb_insert(newsk, ((struct sk_buff_list *)next)->prev, next, list);
2282 * __skb_queue_head - queue a buffer at the list head
2283 * @list: list to use
2284 * @newsk: buffer to queue
2286 * Queue a buffer at the start of a list. This function takes no locks
2287 * and you must therefore hold required locks before calling it.
2289 * A buffer cannot be placed on two lists at the same time.
2291 static inline void __skb_queue_head(struct sk_buff_head *list,
2292 struct sk_buff *newsk)
2294 __skb_queue_after(list, (struct sk_buff *)list, newsk);
2296 void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
2299 * __skb_queue_tail - queue a buffer at the list tail
2300 * @list: list to use
2301 * @newsk: buffer to queue
2303 * Queue a buffer at the end of a list. This function takes no locks
2304 * and you must therefore hold required locks before calling it.
2306 * A buffer cannot be placed on two lists at the same time.
2308 static inline void __skb_queue_tail(struct sk_buff_head *list,
2309 struct sk_buff *newsk)
2311 __skb_queue_before(list, (struct sk_buff *)list, newsk);
2313 void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
2316 * remove sk_buff from list. _Must_ be called atomically, and with
2319 void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
2320 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
2322 struct sk_buff *next, *prev;
2324 WRITE_ONCE(list->qlen, list->qlen - 1);
2327 skb->next = skb->prev = NULL;
2328 WRITE_ONCE(next->prev, prev);
2329 WRITE_ONCE(prev->next, next);
2333 * __skb_dequeue - remove from the head of the queue
2334 * @list: list to dequeue from
2336 * Remove the head of the list. This function does not take any locks
2337 * so must be used with appropriate locks held only. The head item is
2338 * returned or %NULL if the list is empty.
2340 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
2342 struct sk_buff *skb = skb_peek(list);
2344 __skb_unlink(skb, list);
2347 struct sk_buff *skb_dequeue(struct sk_buff_head *list);
2350 * __skb_dequeue_tail - remove from the tail of the queue
2351 * @list: list to dequeue from
2353 * Remove the tail of the list. This function does not take any locks
2354 * so must be used with appropriate locks held only. The tail item is
2355 * returned or %NULL if the list is empty.
2357 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
2359 struct sk_buff *skb = skb_peek_tail(list);
2361 __skb_unlink(skb, list);
2364 struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
2367 static inline bool skb_is_nonlinear(const struct sk_buff *skb)
2369 return skb->data_len;
2372 static inline unsigned int skb_headlen(const struct sk_buff *skb)
2374 return skb->len - skb->data_len;
2377 static inline unsigned int __skb_pagelen(const struct sk_buff *skb)
2379 unsigned int i, len = 0;
2381 for (i = skb_shinfo(skb)->nr_frags - 1; (int)i >= 0; i--)
2382 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
2386 static inline unsigned int skb_pagelen(const struct sk_buff *skb)
2388 return skb_headlen(skb) + __skb_pagelen(skb);
2391 static inline void __skb_fill_page_desc_noacc(struct skb_shared_info *shinfo,
2392 int i, struct page *page,
2395 skb_frag_t *frag = &shinfo->frags[i];
2398 * Propagate page pfmemalloc to the skb if we can. The problem is
2399 * that not all callers have unique ownership of the page but rely
2400 * on page_is_pfmemalloc doing the right thing(tm).
2402 frag->bv_page = page;
2403 frag->bv_offset = off;
2404 skb_frag_size_set(frag, size);
2408 * skb_len_add - adds a number to len fields of skb
2409 * @skb: buffer to add len to
2410 * @delta: number of bytes to add
2412 static inline void skb_len_add(struct sk_buff *skb, int delta)
2415 skb->data_len += delta;
2416 skb->truesize += delta;
2420 * __skb_fill_page_desc - initialise a paged fragment in an skb
2421 * @skb: buffer containing fragment to be initialised
2422 * @i: paged fragment index to initialise
2423 * @page: the page to use for this fragment
2424 * @off: the offset to the data with @page
2425 * @size: the length of the data
2427 * Initialises the @i'th fragment of @skb to point to &size bytes at
2428 * offset @off within @page.
2430 * Does not take any additional reference on the fragment.
2432 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
2433 struct page *page, int off, int size)
2435 __skb_fill_page_desc_noacc(skb_shinfo(skb), i, page, off, size);
2436 page = compound_head(page);
2437 if (page_is_pfmemalloc(page))
2438 skb->pfmemalloc = true;
2442 * skb_fill_page_desc - initialise a paged fragment in an skb
2443 * @skb: buffer containing fragment to be initialised
2444 * @i: paged fragment index to initialise
2445 * @page: the page to use for this fragment
2446 * @off: the offset to the data with @page
2447 * @size: the length of the data
2449 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
2450 * @skb to point to @size bytes at offset @off within @page. In
2451 * addition updates @skb such that @i is the last fragment.
2453 * Does not take any additional reference on the fragment.
2455 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
2456 struct page *page, int off, int size)
2458 __skb_fill_page_desc(skb, i, page, off, size);
2459 skb_shinfo(skb)->nr_frags = i + 1;
2463 * skb_fill_page_desc_noacc - initialise a paged fragment in an skb
2464 * @skb: buffer containing fragment to be initialised
2465 * @i: paged fragment index to initialise
2466 * @page: the page to use for this fragment
2467 * @off: the offset to the data with @page
2468 * @size: the length of the data
2470 * Variant of skb_fill_page_desc() which does not deal with
2471 * pfmemalloc, if page is not owned by us.
2473 static inline void skb_fill_page_desc_noacc(struct sk_buff *skb, int i,
2474 struct page *page, int off,
2477 struct skb_shared_info *shinfo = skb_shinfo(skb);
2479 __skb_fill_page_desc_noacc(shinfo, i, page, off, size);
2480 shinfo->nr_frags = i + 1;
2483 void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
2484 int size, unsigned int truesize);
2486 void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
2487 unsigned int truesize);
2489 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
2491 #ifdef NET_SKBUFF_DATA_USES_OFFSET
2492 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2494 return skb->head + skb->tail;
2497 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2499 skb->tail = skb->data - skb->head;
2502 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2504 skb_reset_tail_pointer(skb);
2505 skb->tail += offset;
2508 #else /* NET_SKBUFF_DATA_USES_OFFSET */
2509 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2514 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2516 skb->tail = skb->data;
2519 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2521 skb->tail = skb->data + offset;
2524 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
2526 static inline void skb_assert_len(struct sk_buff *skb)
2528 #ifdef CONFIG_DEBUG_NET
2529 if (WARN_ONCE(!skb->len, "%s\n", __func__))
2530 DO_ONCE_LITE(skb_dump, KERN_ERR, skb, false);
2531 #endif /* CONFIG_DEBUG_NET */
2535 * Add data to an sk_buff
2537 void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
2538 void *skb_put(struct sk_buff *skb, unsigned int len);
2539 static inline void *__skb_put(struct sk_buff *skb, unsigned int len)
2541 void *tmp = skb_tail_pointer(skb);
2542 SKB_LINEAR_ASSERT(skb);
2548 static inline void *__skb_put_zero(struct sk_buff *skb, unsigned int len)
2550 void *tmp = __skb_put(skb, len);
2552 memset(tmp, 0, len);
2556 static inline void *__skb_put_data(struct sk_buff *skb, const void *data,
2559 void *tmp = __skb_put(skb, len);
2561 memcpy(tmp, data, len);
2565 static inline void __skb_put_u8(struct sk_buff *skb, u8 val)
2567 *(u8 *)__skb_put(skb, 1) = val;
2570 static inline void *skb_put_zero(struct sk_buff *skb, unsigned int len)
2572 void *tmp = skb_put(skb, len);
2574 memset(tmp, 0, len);
2579 static inline void *skb_put_data(struct sk_buff *skb, const void *data,
2582 void *tmp = skb_put(skb, len);
2584 memcpy(tmp, data, len);
2589 static inline void skb_put_u8(struct sk_buff *skb, u8 val)
2591 *(u8 *)skb_put(skb, 1) = val;
2594 void *skb_push(struct sk_buff *skb, unsigned int len);
2595 static inline void *__skb_push(struct sk_buff *skb, unsigned int len)
2602 void *skb_pull(struct sk_buff *skb, unsigned int len);
2603 static inline void *__skb_pull(struct sk_buff *skb, unsigned int len)
2606 if (unlikely(skb->len < skb->data_len)) {
2607 #if defined(CONFIG_DEBUG_NET)
2609 pr_err("__skb_pull(len=%u)\n", len);
2610 skb_dump(KERN_ERR, skb, false);
2614 return skb->data += len;
2617 static inline void *skb_pull_inline(struct sk_buff *skb, unsigned int len)
2619 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
2622 void *skb_pull_data(struct sk_buff *skb, size_t len);
2624 void *__pskb_pull_tail(struct sk_buff *skb, int delta);
2626 static inline bool pskb_may_pull(struct sk_buff *skb, unsigned int len)
2628 if (likely(len <= skb_headlen(skb)))
2630 if (unlikely(len > skb->len))
2632 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
2635 static inline void *pskb_pull(struct sk_buff *skb, unsigned int len)
2637 if (!pskb_may_pull(skb, len))
2641 return skb->data += len;
2644 void skb_condense(struct sk_buff *skb);
2647 * skb_headroom - bytes at buffer head
2648 * @skb: buffer to check
2650 * Return the number of bytes of free space at the head of an &sk_buff.
2652 static inline unsigned int skb_headroom(const struct sk_buff *skb)
2654 return skb->data - skb->head;
2658 * skb_tailroom - bytes at buffer end
2659 * @skb: buffer to check
2661 * Return the number of bytes of free space at the tail of an sk_buff
2663 static inline int skb_tailroom(const struct sk_buff *skb)
2665 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
2669 * skb_availroom - bytes at buffer end
2670 * @skb: buffer to check
2672 * Return the number of bytes of free space at the tail of an sk_buff
2673 * allocated by sk_stream_alloc()
2675 static inline int skb_availroom(const struct sk_buff *skb)
2677 if (skb_is_nonlinear(skb))
2680 return skb->end - skb->tail - skb->reserved_tailroom;
2684 * skb_reserve - adjust headroom
2685 * @skb: buffer to alter
2686 * @len: bytes to move
2688 * Increase the headroom of an empty &sk_buff by reducing the tail
2689 * room. This is only allowed for an empty buffer.
2691 static inline void skb_reserve(struct sk_buff *skb, int len)
2698 * skb_tailroom_reserve - adjust reserved_tailroom
2699 * @skb: buffer to alter
2700 * @mtu: maximum amount of headlen permitted
2701 * @needed_tailroom: minimum amount of reserved_tailroom
2703 * Set reserved_tailroom so that headlen can be as large as possible but
2704 * not larger than mtu and tailroom cannot be smaller than
2706 * The required headroom should already have been reserved before using
2709 static inline void skb_tailroom_reserve(struct sk_buff *skb, unsigned int mtu,
2710 unsigned int needed_tailroom)
2712 SKB_LINEAR_ASSERT(skb);
2713 if (mtu < skb_tailroom(skb) - needed_tailroom)
2714 /* use at most mtu */
2715 skb->reserved_tailroom = skb_tailroom(skb) - mtu;
2717 /* use up to all available space */
2718 skb->reserved_tailroom = needed_tailroom;
2721 #define ENCAP_TYPE_ETHER 0
2722 #define ENCAP_TYPE_IPPROTO 1
2724 static inline void skb_set_inner_protocol(struct sk_buff *skb,
2727 skb->inner_protocol = protocol;
2728 skb->inner_protocol_type = ENCAP_TYPE_ETHER;
2731 static inline void skb_set_inner_ipproto(struct sk_buff *skb,
2734 skb->inner_ipproto = ipproto;
2735 skb->inner_protocol_type = ENCAP_TYPE_IPPROTO;
2738 static inline void skb_reset_inner_headers(struct sk_buff *skb)
2740 skb->inner_mac_header = skb->mac_header;
2741 skb->inner_network_header = skb->network_header;
2742 skb->inner_transport_header = skb->transport_header;
2745 static inline void skb_reset_mac_len(struct sk_buff *skb)
2747 skb->mac_len = skb->network_header - skb->mac_header;
2750 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
2753 return skb->head + skb->inner_transport_header;
2756 static inline int skb_inner_transport_offset(const struct sk_buff *skb)
2758 return skb_inner_transport_header(skb) - skb->data;
2761 static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
2763 skb->inner_transport_header = skb->data - skb->head;
2766 static inline void skb_set_inner_transport_header(struct sk_buff *skb,
2769 skb_reset_inner_transport_header(skb);
2770 skb->inner_transport_header += offset;
2773 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
2775 return skb->head + skb->inner_network_header;
2778 static inline void skb_reset_inner_network_header(struct sk_buff *skb)
2780 skb->inner_network_header = skb->data - skb->head;
2783 static inline void skb_set_inner_network_header(struct sk_buff *skb,
2786 skb_reset_inner_network_header(skb);
2787 skb->inner_network_header += offset;
2790 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
2792 return skb->head + skb->inner_mac_header;
2795 static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
2797 skb->inner_mac_header = skb->data - skb->head;
2800 static inline void skb_set_inner_mac_header(struct sk_buff *skb,
2803 skb_reset_inner_mac_header(skb);
2804 skb->inner_mac_header += offset;
2806 static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
2808 return skb->transport_header != (typeof(skb->transport_header))~0U;
2811 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
2813 DEBUG_NET_WARN_ON_ONCE(!skb_transport_header_was_set(skb));
2814 return skb->head + skb->transport_header;
2817 static inline void skb_reset_transport_header(struct sk_buff *skb)
2819 skb->transport_header = skb->data - skb->head;
2822 static inline void skb_set_transport_header(struct sk_buff *skb,
2825 skb_reset_transport_header(skb);
2826 skb->transport_header += offset;
2829 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
2831 return skb->head + skb->network_header;
2834 static inline void skb_reset_network_header(struct sk_buff *skb)
2836 skb->network_header = skb->data - skb->head;
2839 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
2841 skb_reset_network_header(skb);
2842 skb->network_header += offset;
2845 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
2847 return skb->mac_header != (typeof(skb->mac_header))~0U;
2850 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
2852 DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb));
2853 return skb->head + skb->mac_header;
2856 static inline int skb_mac_offset(const struct sk_buff *skb)
2858 return skb_mac_header(skb) - skb->data;
2861 static inline u32 skb_mac_header_len(const struct sk_buff *skb)
2863 DEBUG_NET_WARN_ON_ONCE(!skb_mac_header_was_set(skb));
2864 return skb->network_header - skb->mac_header;
2867 static inline void skb_unset_mac_header(struct sk_buff *skb)
2869 skb->mac_header = (typeof(skb->mac_header))~0U;
2872 static inline void skb_reset_mac_header(struct sk_buff *skb)
2874 skb->mac_header = skb->data - skb->head;
2877 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
2879 skb_reset_mac_header(skb);
2880 skb->mac_header += offset;
2883 static inline void skb_pop_mac_header(struct sk_buff *skb)
2885 skb->mac_header = skb->network_header;
2888 static inline void skb_probe_transport_header(struct sk_buff *skb)
2890 struct flow_keys_basic keys;
2892 if (skb_transport_header_was_set(skb))
2895 if (skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
2897 skb_set_transport_header(skb, keys.control.thoff);
2900 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
2902 if (skb_mac_header_was_set(skb)) {
2903 const unsigned char *old_mac = skb_mac_header(skb);
2905 skb_set_mac_header(skb, -skb->mac_len);
2906 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
2910 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
2912 return skb->csum_start - skb_headroom(skb);
2915 static inline unsigned char *skb_checksum_start(const struct sk_buff *skb)
2917 return skb->head + skb->csum_start;
2920 static inline int skb_transport_offset(const struct sk_buff *skb)
2922 return skb_transport_header(skb) - skb->data;
2925 static inline u32 skb_network_header_len(const struct sk_buff *skb)
2927 return skb->transport_header - skb->network_header;
2930 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb)
2932 return skb->inner_transport_header - skb->inner_network_header;
2935 static inline int skb_network_offset(const struct sk_buff *skb)
2937 return skb_network_header(skb) - skb->data;
2940 static inline int skb_inner_network_offset(const struct sk_buff *skb)
2942 return skb_inner_network_header(skb) - skb->data;
2945 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
2947 return pskb_may_pull(skb, skb_network_offset(skb) + len);
2951 * CPUs often take a performance hit when accessing unaligned memory
2952 * locations. The actual performance hit varies, it can be small if the
2953 * hardware handles it or large if we have to take an exception and fix it
2956 * Since an ethernet header is 14 bytes network drivers often end up with
2957 * the IP header at an unaligned offset. The IP header can be aligned by
2958 * shifting the start of the packet by 2 bytes. Drivers should do this
2961 * skb_reserve(skb, NET_IP_ALIGN);
2963 * The downside to this alignment of the IP header is that the DMA is now
2964 * unaligned. On some architectures the cost of an unaligned DMA is high
2965 * and this cost outweighs the gains made by aligning the IP header.
2967 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
2970 #ifndef NET_IP_ALIGN
2971 #define NET_IP_ALIGN 2
2975 * The networking layer reserves some headroom in skb data (via
2976 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
2977 * the header has to grow. In the default case, if the header has to grow
2978 * 32 bytes or less we avoid the reallocation.
2980 * Unfortunately this headroom changes the DMA alignment of the resulting
2981 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
2982 * on some architectures. An architecture can override this value,
2983 * perhaps setting it to a cacheline in size (since that will maintain
2984 * cacheline alignment of the DMA). It must be a power of 2.
2986 * Various parts of the networking layer expect at least 32 bytes of
2987 * headroom, you should not reduce this.
2989 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
2990 * to reduce average number of cache lines per packet.
2991 * get_rps_cpu() for example only access one 64 bytes aligned block :
2992 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
2995 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
2998 int ___pskb_trim(struct sk_buff *skb, unsigned int len);
3000 static inline void __skb_set_length(struct sk_buff *skb, unsigned int len)
3002 if (WARN_ON(skb_is_nonlinear(skb)))
3005 skb_set_tail_pointer(skb, len);
3008 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
3010 __skb_set_length(skb, len);
3013 void skb_trim(struct sk_buff *skb, unsigned int len);
3015 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
3018 return ___pskb_trim(skb, len);
3019 __skb_trim(skb, len);
3023 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
3025 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
3029 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
3030 * @skb: buffer to alter
3033 * This is identical to pskb_trim except that the caller knows that
3034 * the skb is not cloned so we should never get an error due to out-
3037 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
3039 int err = pskb_trim(skb, len);
3043 static inline int __skb_grow(struct sk_buff *skb, unsigned int len)
3045 unsigned int diff = len - skb->len;
3047 if (skb_tailroom(skb) < diff) {
3048 int ret = pskb_expand_head(skb, 0, diff - skb_tailroom(skb),
3053 __skb_set_length(skb, len);
3058 * skb_orphan - orphan a buffer
3059 * @skb: buffer to orphan
3061 * If a buffer currently has an owner then we call the owner's
3062 * destructor function and make the @skb unowned. The buffer continues
3063 * to exist but is no longer charged to its former owner.
3065 static inline void skb_orphan(struct sk_buff *skb)
3067 if (skb->destructor) {
3068 skb->destructor(skb);
3069 skb->destructor = NULL;
3077 * skb_orphan_frags - orphan the frags contained in a buffer
3078 * @skb: buffer to orphan frags from
3079 * @gfp_mask: allocation mask for replacement pages
3081 * For each frag in the SKB which needs a destructor (i.e. has an
3082 * owner) create a copy of that frag and release the original
3083 * page by calling the destructor.
3085 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
3087 if (likely(!skb_zcopy(skb)))
3089 if (skb_shinfo(skb)->flags & SKBFL_DONT_ORPHAN)
3091 return skb_copy_ubufs(skb, gfp_mask);
3094 /* Frags must be orphaned, even if refcounted, if skb might loop to rx path */
3095 static inline int skb_orphan_frags_rx(struct sk_buff *skb, gfp_t gfp_mask)
3097 if (likely(!skb_zcopy(skb)))
3099 return skb_copy_ubufs(skb, gfp_mask);
3103 * __skb_queue_purge - empty a list
3104 * @list: list to empty
3106 * Delete all buffers on an &sk_buff list. Each buffer is removed from
3107 * the list and one reference dropped. This function does not take the
3108 * list lock and the caller must hold the relevant locks to use it.
3110 static inline void __skb_queue_purge(struct sk_buff_head *list)
3112 struct sk_buff *skb;
3113 while ((skb = __skb_dequeue(list)) != NULL)
3116 void skb_queue_purge(struct sk_buff_head *list);
3118 unsigned int skb_rbtree_purge(struct rb_root *root);
3120 void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);
3123 * netdev_alloc_frag - allocate a page fragment
3124 * @fragsz: fragment size
3126 * Allocates a frag from a page for receive buffer.
3127 * Uses GFP_ATOMIC allocations.
3129 static inline void *netdev_alloc_frag(unsigned int fragsz)
3131 return __netdev_alloc_frag_align(fragsz, ~0u);
3134 static inline void *netdev_alloc_frag_align(unsigned int fragsz,
3137 WARN_ON_ONCE(!is_power_of_2(align));
3138 return __netdev_alloc_frag_align(fragsz, -align);
3141 struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length,
3145 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
3146 * @dev: network device to receive on
3147 * @length: length to allocate
3149 * Allocate a new &sk_buff and assign it a usage count of one. The
3150 * buffer has unspecified headroom built in. Users should allocate
3151 * the headroom they think they need without accounting for the
3152 * built in space. The built in space is used for optimisations.
3154 * %NULL is returned if there is no free memory. Although this function
3155 * allocates memory it can be called from an interrupt.
3157 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
3158 unsigned int length)
3160 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
3163 /* legacy helper around __netdev_alloc_skb() */
3164 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
3167 return __netdev_alloc_skb(NULL, length, gfp_mask);
3170 /* legacy helper around netdev_alloc_skb() */
3171 static inline struct sk_buff *dev_alloc_skb(unsigned int length)
3173 return netdev_alloc_skb(NULL, length);
3177 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
3178 unsigned int length, gfp_t gfp)
3180 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
3182 if (NET_IP_ALIGN && skb)
3183 skb_reserve(skb, NET_IP_ALIGN);
3187 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
3188 unsigned int length)
3190 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
3193 static inline void skb_free_frag(void *addr)
3195 page_frag_free(addr);
3198 void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask);
3200 static inline void *napi_alloc_frag(unsigned int fragsz)
3202 return __napi_alloc_frag_align(fragsz, ~0u);
3205 static inline void *napi_alloc_frag_align(unsigned int fragsz,
3208 WARN_ON_ONCE(!is_power_of_2(align));
3209 return __napi_alloc_frag_align(fragsz, -align);
3212 struct sk_buff *__napi_alloc_skb(struct napi_struct *napi,
3213 unsigned int length, gfp_t gfp_mask);
3214 static inline struct sk_buff *napi_alloc_skb(struct napi_struct *napi,
3215 unsigned int length)
3217 return __napi_alloc_skb(napi, length, GFP_ATOMIC);
3219 void napi_consume_skb(struct sk_buff *skb, int budget);
3221 void napi_skb_free_stolen_head(struct sk_buff *skb);
3222 void __kfree_skb_defer(struct sk_buff *skb);
3225 * __dev_alloc_pages - allocate page for network Rx
3226 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
3227 * @order: size of the allocation
3229 * Allocate a new page.
3231 * %NULL is returned if there is no free memory.
3233 static inline struct page *__dev_alloc_pages(gfp_t gfp_mask,
3236 /* This piece of code contains several assumptions.
3237 * 1. This is for device Rx, therefor a cold page is preferred.
3238 * 2. The expectation is the user wants a compound page.
3239 * 3. If requesting a order 0 page it will not be compound
3240 * due to the check to see if order has a value in prep_new_page
3241 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
3242 * code in gfp_to_alloc_flags that should be enforcing this.
3244 gfp_mask |= __GFP_COMP | __GFP_MEMALLOC;
3246 return alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
3249 static inline struct page *dev_alloc_pages(unsigned int order)
3251 return __dev_alloc_pages(GFP_ATOMIC | __GFP_NOWARN, order);
3255 * __dev_alloc_page - allocate a page for network Rx
3256 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
3258 * Allocate a new page.
3260 * %NULL is returned if there is no free memory.
3262 static inline struct page *__dev_alloc_page(gfp_t gfp_mask)
3264 return __dev_alloc_pages(gfp_mask, 0);
3267 static inline struct page *dev_alloc_page(void)
3269 return dev_alloc_pages(0);
3273 * dev_page_is_reusable - check whether a page can be reused for network Rx
3274 * @page: the page to test
3276 * A page shouldn't be considered for reusing/recycling if it was allocated
3277 * under memory pressure or at a distant memory node.
3279 * Returns false if this page should be returned to page allocator, true
3282 static inline bool dev_page_is_reusable(const struct page *page)
3284 return likely(page_to_nid(page) == numa_mem_id() &&
3285 !page_is_pfmemalloc(page));
3289 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
3290 * @page: The page that was allocated from skb_alloc_page
3291 * @skb: The skb that may need pfmemalloc set
3293 static inline void skb_propagate_pfmemalloc(const struct page *page,
3294 struct sk_buff *skb)
3296 if (page_is_pfmemalloc(page))
3297 skb->pfmemalloc = true;
3301 * skb_frag_off() - Returns the offset of a skb fragment
3302 * @frag: the paged fragment
3304 static inline unsigned int skb_frag_off(const skb_frag_t *frag)
3306 return frag->bv_offset;
3310 * skb_frag_off_add() - Increments the offset of a skb fragment by @delta
3311 * @frag: skb fragment
3312 * @delta: value to add
3314 static inline void skb_frag_off_add(skb_frag_t *frag, int delta)
3316 frag->bv_offset += delta;
3320 * skb_frag_off_set() - Sets the offset of a skb fragment
3321 * @frag: skb fragment
3322 * @offset: offset of fragment
3324 static inline void skb_frag_off_set(skb_frag_t *frag, unsigned int offset)
3326 frag->bv_offset = offset;
3330 * skb_frag_off_copy() - Sets the offset of a skb fragment from another fragment
3331 * @fragto: skb fragment where offset is set
3332 * @fragfrom: skb fragment offset is copied from
3334 static inline void skb_frag_off_copy(skb_frag_t *fragto,
3335 const skb_frag_t *fragfrom)
3337 fragto->bv_offset = fragfrom->bv_offset;
3341 * skb_frag_page - retrieve the page referred to by a paged fragment
3342 * @frag: the paged fragment
3344 * Returns the &struct page associated with @frag.
3346 static inline struct page *skb_frag_page(const skb_frag_t *frag)
3348 return frag->bv_page;
3352 * __skb_frag_ref - take an addition reference on a paged fragment.
3353 * @frag: the paged fragment
3355 * Takes an additional reference on the paged fragment @frag.
3357 static inline void __skb_frag_ref(skb_frag_t *frag)
3359 get_page(skb_frag_page(frag));
3363 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
3365 * @f: the fragment offset.
3367 * Takes an additional reference on the @f'th paged fragment of @skb.
3369 static inline void skb_frag_ref(struct sk_buff *skb, int f)
3371 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
3375 * __skb_frag_unref - release a reference on a paged fragment.
3376 * @frag: the paged fragment
3377 * @recycle: recycle the page if allocated via page_pool
3379 * Releases a reference on the paged fragment @frag
3380 * or recycles the page via the page_pool API.
3382 static inline void __skb_frag_unref(skb_frag_t *frag, bool recycle)
3384 struct page *page = skb_frag_page(frag);
3386 #ifdef CONFIG_PAGE_POOL
3387 if (recycle && page_pool_return_skb_page(page))
3394 * skb_frag_unref - release a reference on a paged fragment of an skb.
3396 * @f: the fragment offset
3398 * Releases a reference on the @f'th paged fragment of @skb.
3400 static inline void skb_frag_unref(struct sk_buff *skb, int f)
3402 struct skb_shared_info *shinfo = skb_shinfo(skb);
3404 if (!skb_zcopy_managed(skb))
3405 __skb_frag_unref(&shinfo->frags[f], skb->pp_recycle);
3409 * skb_frag_address - gets the address of the data contained in a paged fragment
3410 * @frag: the paged fragment buffer
3412 * Returns the address of the data within @frag. The page must already
3415 static inline void *skb_frag_address(const skb_frag_t *frag)
3417 return page_address(skb_frag_page(frag)) + skb_frag_off(frag);
3421 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
3422 * @frag: the paged fragment buffer
3424 * Returns the address of the data within @frag. Checks that the page
3425 * is mapped and returns %NULL otherwise.
3427 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
3429 void *ptr = page_address(skb_frag_page(frag));
3433 return ptr + skb_frag_off(frag);
3437 * skb_frag_page_copy() - sets the page in a fragment from another fragment
3438 * @fragto: skb fragment where page is set
3439 * @fragfrom: skb fragment page is copied from
3441 static inline void skb_frag_page_copy(skb_frag_t *fragto,
3442 const skb_frag_t *fragfrom)
3444 fragto->bv_page = fragfrom->bv_page;
3448 * __skb_frag_set_page - sets the page contained in a paged fragment
3449 * @frag: the paged fragment
3450 * @page: the page to set
3452 * Sets the fragment @frag to contain @page.
3454 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
3456 frag->bv_page = page;
3460 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
3462 * @f: the fragment offset
3463 * @page: the page to set
3465 * Sets the @f'th fragment of @skb to contain @page.
3467 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
3470 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
3473 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);
3476 * skb_frag_dma_map - maps a paged fragment via the DMA API
3477 * @dev: the device to map the fragment to
3478 * @frag: the paged fragment to map
3479 * @offset: the offset within the fragment (starting at the
3480 * fragment's own offset)
3481 * @size: the number of bytes to map
3482 * @dir: the direction of the mapping (``PCI_DMA_*``)
3484 * Maps the page associated with @frag to @device.
3486 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
3487 const skb_frag_t *frag,
3488 size_t offset, size_t size,
3489 enum dma_data_direction dir)
3491 return dma_map_page(dev, skb_frag_page(frag),
3492 skb_frag_off(frag) + offset, size, dir);
3495 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
3498 return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
3502 static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb,
3505 return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true);
3510 * skb_clone_writable - is the header of a clone writable
3511 * @skb: buffer to check
3512 * @len: length up to which to write
3514 * Returns true if modifying the header part of the cloned buffer
3515 * does not requires the data to be copied.
3517 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
3519 return !skb_header_cloned(skb) &&
3520 skb_headroom(skb) + len <= skb->hdr_len;
3523 static inline int skb_try_make_writable(struct sk_buff *skb,
3524 unsigned int write_len)
3526 return skb_cloned(skb) && !skb_clone_writable(skb, write_len) &&
3527 pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
3530 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
3535 if (headroom > skb_headroom(skb))
3536 delta = headroom - skb_headroom(skb);
3538 if (delta || cloned)
3539 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
3545 * skb_cow - copy header of skb when it is required
3546 * @skb: buffer to cow
3547 * @headroom: needed headroom
3549 * If the skb passed lacks sufficient headroom or its data part
3550 * is shared, data is reallocated. If reallocation fails, an error
3551 * is returned and original skb is not changed.
3553 * The result is skb with writable area skb->head...skb->tail
3554 * and at least @headroom of space at head.
3556 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
3558 return __skb_cow(skb, headroom, skb_cloned(skb));
3562 * skb_cow_head - skb_cow but only making the head writable
3563 * @skb: buffer to cow
3564 * @headroom: needed headroom
3566 * This function is identical to skb_cow except that we replace the
3567 * skb_cloned check by skb_header_cloned. It should be used when
3568 * you only need to push on some header and do not need to modify
3571 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
3573 return __skb_cow(skb, headroom, skb_header_cloned(skb));
3577 * skb_padto - pad an skbuff up to a minimal size
3578 * @skb: buffer to pad
3579 * @len: minimal length
3581 * Pads up a buffer to ensure the trailing bytes exist and are
3582 * blanked. If the buffer already contains sufficient data it
3583 * is untouched. Otherwise it is extended. Returns zero on
3584 * success. The skb is freed on error.
3586 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
3588 unsigned int size = skb->len;
3589 if (likely(size >= len))
3591 return skb_pad(skb, len - size);
3595 * __skb_put_padto - increase size and pad an skbuff up to a minimal size
3596 * @skb: buffer to pad
3597 * @len: minimal length
3598 * @free_on_error: free buffer on error
3600 * Pads up a buffer to ensure the trailing bytes exist and are
3601 * blanked. If the buffer already contains sufficient data it
3602 * is untouched. Otherwise it is extended. Returns zero on
3603 * success. The skb is freed on error if @free_on_error is true.
3605 static inline int __must_check __skb_put_padto(struct sk_buff *skb,
3609 unsigned int size = skb->len;
3611 if (unlikely(size < len)) {
3613 if (__skb_pad(skb, len, free_on_error))
3615 __skb_put(skb, len);
3621 * skb_put_padto - increase size and pad an skbuff up to a minimal size
3622 * @skb: buffer to pad
3623 * @len: minimal length
3625 * Pads up a buffer to ensure the trailing bytes exist and are
3626 * blanked. If the buffer already contains sufficient data it
3627 * is untouched. Otherwise it is extended. Returns zero on
3628 * success. The skb is freed on error.
3630 static inline int __must_check skb_put_padto(struct sk_buff *skb, unsigned int len)
3632 return __skb_put_padto(skb, len, true);
3635 static inline int skb_add_data(struct sk_buff *skb,
3636 struct iov_iter *from, int copy)
3638 const int off = skb->len;
3640 if (skb->ip_summed == CHECKSUM_NONE) {
3642 if (csum_and_copy_from_iter_full(skb_put(skb, copy), copy,
3644 skb->csum = csum_block_add(skb->csum, csum, off);
3647 } else if (copy_from_iter_full(skb_put(skb, copy), copy, from))
3650 __skb_trim(skb, off);
3654 static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
3655 const struct page *page, int off)
3660 const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1];
3662 return page == skb_frag_page(frag) &&
3663 off == skb_frag_off(frag) + skb_frag_size(frag);
3668 static inline int __skb_linearize(struct sk_buff *skb)
3670 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
3674 * skb_linearize - convert paged skb to linear one
3675 * @skb: buffer to linarize
3677 * If there is no free memory -ENOMEM is returned, otherwise zero
3678 * is returned and the old skb data released.
3680 static inline int skb_linearize(struct sk_buff *skb)
3682 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
3686 * skb_has_shared_frag - can any frag be overwritten
3687 * @skb: buffer to test
3689 * Return true if the skb has at least one frag that might be modified
3690 * by an external entity (as in vmsplice()/sendfile())
3692 static inline bool skb_has_shared_frag(const struct sk_buff *skb)
3694 return skb_is_nonlinear(skb) &&
3695 skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG;
3699 * skb_linearize_cow - make sure skb is linear and writable
3700 * @skb: buffer to process
3702 * If there is no free memory -ENOMEM is returned, otherwise zero
3703 * is returned and the old skb data released.
3705 static inline int skb_linearize_cow(struct sk_buff *skb)
3707 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
3708 __skb_linearize(skb) : 0;
3711 static __always_inline void
3712 __skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
3715 if (skb->ip_summed == CHECKSUM_COMPLETE)
3716 skb->csum = csum_block_sub(skb->csum,
3717 csum_partial(start, len, 0), off);
3718 else if (skb->ip_summed == CHECKSUM_PARTIAL &&
3719 skb_checksum_start_offset(skb) < 0)
3720 skb->ip_summed = CHECKSUM_NONE;
3724 * skb_postpull_rcsum - update checksum for received skb after pull
3725 * @skb: buffer to update
3726 * @start: start of data before pull
3727 * @len: length of data pulled
3729 * After doing a pull on a received packet, you need to call this to
3730 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
3731 * CHECKSUM_NONE so that it can be recomputed from scratch.
3733 static inline void skb_postpull_rcsum(struct sk_buff *skb,
3734 const void *start, unsigned int len)
3736 if (skb->ip_summed == CHECKSUM_COMPLETE)
3737 skb->csum = wsum_negate(csum_partial(start, len,
3738 wsum_negate(skb->csum)));
3739 else if (skb->ip_summed == CHECKSUM_PARTIAL &&
3740 skb_checksum_start_offset(skb) < 0)
3741 skb->ip_summed = CHECKSUM_NONE;
3744 static __always_inline void
3745 __skb_postpush_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
3748 if (skb->ip_summed == CHECKSUM_COMPLETE)
3749 skb->csum = csum_block_add(skb->csum,
3750 csum_partial(start, len, 0), off);
3754 * skb_postpush_rcsum - update checksum for received skb after push
3755 * @skb: buffer to update
3756 * @start: start of data after push
3757 * @len: length of data pushed
3759 * After doing a push on a received packet, you need to call this to
3760 * update the CHECKSUM_COMPLETE checksum.
3762 static inline void skb_postpush_rcsum(struct sk_buff *skb,
3763 const void *start, unsigned int len)
3765 __skb_postpush_rcsum(skb, start, len, 0);
3768 void *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
3771 * skb_push_rcsum - push skb and update receive checksum
3772 * @skb: buffer to update
3773 * @len: length of data pulled
3775 * This function performs an skb_push on the packet and updates
3776 * the CHECKSUM_COMPLETE checksum. It should be used on
3777 * receive path processing instead of skb_push unless you know
3778 * that the checksum difference is zero (e.g., a valid IP header)
3779 * or you are setting ip_summed to CHECKSUM_NONE.
3781 static inline void *skb_push_rcsum(struct sk_buff *skb, unsigned int len)
3784 skb_postpush_rcsum(skb, skb->data, len);
3788 int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len);
3790 * pskb_trim_rcsum - trim received skb and update checksum
3791 * @skb: buffer to trim
3794 * This is exactly the same as pskb_trim except that it ensures the
3795 * checksum of received packets are still valid after the operation.
3796 * It can change skb pointers.
3799 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
3801 if (likely(len >= skb->len))
3803 return pskb_trim_rcsum_slow(skb, len);
3806 static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len)
3808 if (skb->ip_summed == CHECKSUM_COMPLETE)
3809 skb->ip_summed = CHECKSUM_NONE;
3810 __skb_trim(skb, len);
3814 static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len)
3816 if (skb->ip_summed == CHECKSUM_COMPLETE)
3817 skb->ip_summed = CHECKSUM_NONE;
3818 return __skb_grow(skb, len);
3821 #define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode)
3822 #define skb_rb_first(root) rb_to_skb(rb_first(root))
3823 #define skb_rb_last(root) rb_to_skb(rb_last(root))
3824 #define skb_rb_next(skb) rb_to_skb(rb_next(&(skb)->rbnode))
3825 #define skb_rb_prev(skb) rb_to_skb(rb_prev(&(skb)->rbnode))
3827 #define skb_queue_walk(queue, skb) \
3828 for (skb = (queue)->next; \
3829 skb != (struct sk_buff *)(queue); \
3832 #define skb_queue_walk_safe(queue, skb, tmp) \
3833 for (skb = (queue)->next, tmp = skb->next; \
3834 skb != (struct sk_buff *)(queue); \
3835 skb = tmp, tmp = skb->next)
3837 #define skb_queue_walk_from(queue, skb) \
3838 for (; skb != (struct sk_buff *)(queue); \
3841 #define skb_rbtree_walk(skb, root) \
3842 for (skb = skb_rb_first(root); skb != NULL; \
3843 skb = skb_rb_next(skb))
3845 #define skb_rbtree_walk_from(skb) \
3846 for (; skb != NULL; \
3847 skb = skb_rb_next(skb))
3849 #define skb_rbtree_walk_from_safe(skb, tmp) \
3850 for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL); \
3853 #define skb_queue_walk_from_safe(queue, skb, tmp) \
3854 for (tmp = skb->next; \
3855 skb != (struct sk_buff *)(queue); \
3856 skb = tmp, tmp = skb->next)
3858 #define skb_queue_reverse_walk(queue, skb) \
3859 for (skb = (queue)->prev; \
3860 skb != (struct sk_buff *)(queue); \
3863 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
3864 for (skb = (queue)->prev, tmp = skb->prev; \
3865 skb != (struct sk_buff *)(queue); \
3866 skb = tmp, tmp = skb->prev)
3868 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
3869 for (tmp = skb->prev; \
3870 skb != (struct sk_buff *)(queue); \
3871 skb = tmp, tmp = skb->prev)
3873 static inline bool skb_has_frag_list(const struct sk_buff *skb)
3875 return skb_shinfo(skb)->frag_list != NULL;
3878 static inline void skb_frag_list_init(struct sk_buff *skb)
3880 skb_shinfo(skb)->frag_list = NULL;
3883 #define skb_walk_frags(skb, iter) \
3884 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
3887 int __skb_wait_for_more_packets(struct sock *sk, struct sk_buff_head *queue,
3888 int *err, long *timeo_p,
3889 const struct sk_buff *skb);
3890 struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,
3891 struct sk_buff_head *queue,
3894 struct sk_buff **last);
3895 struct sk_buff *__skb_try_recv_datagram(struct sock *sk,
3896 struct sk_buff_head *queue,
3897 unsigned int flags, int *off, int *err,
3898 struct sk_buff **last);
3899 struct sk_buff *__skb_recv_datagram(struct sock *sk,
3900 struct sk_buff_head *sk_queue,
3901 unsigned int flags, int *off, int *err);
3902 struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned int flags, int *err);
3903 __poll_t datagram_poll(struct file *file, struct socket *sock,
3904 struct poll_table_struct *wait);
3905 int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
3906 struct iov_iter *to, int size);
3907 static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset,
3908 struct msghdr *msg, int size)
3910 return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size);
3912 int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
3913 struct msghdr *msg);
3914 int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset,
3915 struct iov_iter *to, int len,
3916 struct ahash_request *hash);
3917 int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
3918 struct iov_iter *from, int len);
3919 int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
3920 void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
3921 void __skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb, int len);
3922 static inline void skb_free_datagram_locked(struct sock *sk,
3923 struct sk_buff *skb)
3925 __skb_free_datagram_locked(sk, skb, 0);
3927 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);
3928 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
3929 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
3930 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
3932 int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,
3933 struct pipe_inode_info *pipe, unsigned int len,
3934 unsigned int flags);
3935 int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset,
3937 int skb_send_sock(struct sock *sk, struct sk_buff *skb, int offset, int len);
3938 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
3939 unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
3940 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
3942 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
3943 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
3944 void skb_scrub_packet(struct sk_buff *skb, bool xnet);
3945 bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu);
3946 bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len);
3947 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
3948 struct sk_buff *skb_segment_list(struct sk_buff *skb, netdev_features_t features,
3949 unsigned int offset);
3950 struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
3951 int skb_ensure_writable(struct sk_buff *skb, unsigned int write_len);
3952 int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci);
3953 int skb_vlan_pop(struct sk_buff *skb);
3954 int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
3955 int skb_eth_pop(struct sk_buff *skb);
3956 int skb_eth_push(struct sk_buff *skb, const unsigned char *dst,
3957 const unsigned char *src);
3958 int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto,
3959 int mac_len, bool ethernet);
3960 int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len,
3962 int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse);
3963 int skb_mpls_dec_ttl(struct sk_buff *skb);
3964 struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy,
3967 static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len)
3969 return copy_from_iter_full(data, len, &msg->msg_iter) ? 0 : -EFAULT;
3972 static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len)
3974 return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT;
3977 struct skb_checksum_ops {
3978 __wsum (*update)(const void *mem, int len, __wsum wsum);
3979 __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len);
3982 extern const struct skb_checksum_ops *crc32c_csum_stub __read_mostly;
3984 __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
3985 __wsum csum, const struct skb_checksum_ops *ops);
3986 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
3989 static inline void * __must_check
3990 __skb_header_pointer(const struct sk_buff *skb, int offset, int len,
3991 const void *data, int hlen, void *buffer)
3993 if (likely(hlen - offset >= len))
3994 return (void *)data + offset;
3996 if (!skb || unlikely(skb_copy_bits(skb, offset, buffer, len) < 0))
4002 static inline void * __must_check
4003 skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer)
4005 return __skb_header_pointer(skb, offset, len, skb->data,
4006 skb_headlen(skb), buffer);
4010 * skb_needs_linearize - check if we need to linearize a given skb
4011 * depending on the given device features.
4012 * @skb: socket buffer to check
4013 * @features: net device features
4015 * Returns true if either:
4016 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
4017 * 2. skb is fragmented and the device does not support SG.
4019 static inline bool skb_needs_linearize(struct sk_buff *skb,
4020 netdev_features_t features)
4022 return skb_is_nonlinear(skb) &&
4023 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
4024 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
4027 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
4029 const unsigned int len)
4031 memcpy(to, skb->data, len);
4034 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
4035 const int offset, void *to,
4036 const unsigned int len)
4038 memcpy(to, skb->data + offset, len);
4041 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
4043 const unsigned int len)
4045 memcpy(skb->data, from, len);
4048 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
4051 const unsigned int len)
4053 memcpy(skb->data + offset, from, len);
4056 void skb_init(void);
4058 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
4064 * skb_get_timestamp - get timestamp from a skb
4065 * @skb: skb to get stamp from
4066 * @stamp: pointer to struct __kernel_old_timeval to store stamp in
4068 * Timestamps are stored in the skb as offsets to a base timestamp.
4069 * This function converts the offset back to a struct timeval and stores
4072 static inline void skb_get_timestamp(const struct sk_buff *skb,
4073 struct __kernel_old_timeval *stamp)
4075 *stamp = ns_to_kernel_old_timeval(skb->tstamp);
4078 static inline void skb_get_new_timestamp(const struct sk_buff *skb,
4079 struct __kernel_sock_timeval *stamp)
4081 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4083 stamp->tv_sec = ts.tv_sec;
4084 stamp->tv_usec = ts.tv_nsec / 1000;
4087 static inline void skb_get_timestampns(const struct sk_buff *skb,
4088 struct __kernel_old_timespec *stamp)
4090 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4092 stamp->tv_sec = ts.tv_sec;
4093 stamp->tv_nsec = ts.tv_nsec;
4096 static inline void skb_get_new_timestampns(const struct sk_buff *skb,
4097 struct __kernel_timespec *stamp)
4099 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
4101 stamp->tv_sec = ts.tv_sec;
4102 stamp->tv_nsec = ts.tv_nsec;
4105 static inline void __net_timestamp(struct sk_buff *skb)
4107 skb->tstamp = ktime_get_real();
4108 skb->mono_delivery_time = 0;
4111 static inline ktime_t net_timedelta(ktime_t t)
4113 return ktime_sub(ktime_get_real(), t);
4116 static inline void skb_set_delivery_time(struct sk_buff *skb, ktime_t kt,
4120 skb->mono_delivery_time = kt && mono;
4123 DECLARE_STATIC_KEY_FALSE(netstamp_needed_key);
4125 /* It is used in the ingress path to clear the delivery_time.
4126 * If needed, set the skb->tstamp to the (rcv) timestamp.
4128 static inline void skb_clear_delivery_time(struct sk_buff *skb)
4130 if (skb->mono_delivery_time) {
4131 skb->mono_delivery_time = 0;
4132 if (static_branch_unlikely(&netstamp_needed_key))
4133 skb->tstamp = ktime_get_real();
4139 static inline void skb_clear_tstamp(struct sk_buff *skb)
4141 if (skb->mono_delivery_time)
4147 static inline ktime_t skb_tstamp(const struct sk_buff *skb)
4149 if (skb->mono_delivery_time)
4155 static inline ktime_t skb_tstamp_cond(const struct sk_buff *skb, bool cond)
4157 if (!skb->mono_delivery_time && skb->tstamp)
4160 if (static_branch_unlikely(&netstamp_needed_key) || cond)
4161 return ktime_get_real();
4166 static inline u8 skb_metadata_len(const struct sk_buff *skb)
4168 return skb_shinfo(skb)->meta_len;
4171 static inline void *skb_metadata_end(const struct sk_buff *skb)
4173 return skb_mac_header(skb);
4176 static inline bool __skb_metadata_differs(const struct sk_buff *skb_a,
4177 const struct sk_buff *skb_b,
4180 const void *a = skb_metadata_end(skb_a);
4181 const void *b = skb_metadata_end(skb_b);
4182 /* Using more efficient varaiant than plain call to memcmp(). */
4183 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
4187 #define __it(x, op) (x -= sizeof(u##op))
4188 #define __it_diff(a, b, op) (*(u##op *)__it(a, op)) ^ (*(u##op *)__it(b, op))
4189 case 32: diffs |= __it_diff(a, b, 64);
4191 case 24: diffs |= __it_diff(a, b, 64);
4193 case 16: diffs |= __it_diff(a, b, 64);
4195 case 8: diffs |= __it_diff(a, b, 64);
4197 case 28: diffs |= __it_diff(a, b, 64);
4199 case 20: diffs |= __it_diff(a, b, 64);
4201 case 12: diffs |= __it_diff(a, b, 64);
4203 case 4: diffs |= __it_diff(a, b, 32);
4208 return memcmp(a - meta_len, b - meta_len, meta_len);
4212 static inline bool skb_metadata_differs(const struct sk_buff *skb_a,
4213 const struct sk_buff *skb_b)
4215 u8 len_a = skb_metadata_len(skb_a);
4216 u8 len_b = skb_metadata_len(skb_b);
4218 if (!(len_a | len_b))
4221 return len_a != len_b ?
4222 true : __skb_metadata_differs(skb_a, skb_b, len_a);
4225 static inline void skb_metadata_set(struct sk_buff *skb, u8 meta_len)
4227 skb_shinfo(skb)->meta_len = meta_len;
4230 static inline void skb_metadata_clear(struct sk_buff *skb)
4232 skb_metadata_set(skb, 0);
4235 struct sk_buff *skb_clone_sk(struct sk_buff *skb);
4237 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
4239 void skb_clone_tx_timestamp(struct sk_buff *skb);
4240 bool skb_defer_rx_timestamp(struct sk_buff *skb);
4242 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
4244 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
4248 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
4253 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
4256 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
4258 * PHY drivers may accept clones of transmitted packets for
4259 * timestamping via their phy_driver.txtstamp method. These drivers
4260 * must call this function to return the skb back to the stack with a
4263 * @skb: clone of the original outgoing packet
4264 * @hwtstamps: hardware time stamps
4267 void skb_complete_tx_timestamp(struct sk_buff *skb,
4268 struct skb_shared_hwtstamps *hwtstamps);
4270 void __skb_tstamp_tx(struct sk_buff *orig_skb, const struct sk_buff *ack_skb,
4271 struct skb_shared_hwtstamps *hwtstamps,
4272 struct sock *sk, int tstype);
4275 * skb_tstamp_tx - queue clone of skb with send time stamps
4276 * @orig_skb: the original outgoing packet
4277 * @hwtstamps: hardware time stamps, may be NULL if not available
4279 * If the skb has a socket associated, then this function clones the
4280 * skb (thus sharing the actual data and optional structures), stores
4281 * the optional hardware time stamping information (if non NULL) or
4282 * generates a software time stamp (otherwise), then queues the clone
4283 * to the error queue of the socket. Errors are silently ignored.
4285 void skb_tstamp_tx(struct sk_buff *orig_skb,
4286 struct skb_shared_hwtstamps *hwtstamps);
4289 * skb_tx_timestamp() - Driver hook for transmit timestamping
4291 * Ethernet MAC Drivers should call this function in their hard_xmit()
4292 * function immediately before giving the sk_buff to the MAC hardware.
4294 * Specifically, one should make absolutely sure that this function is
4295 * called before TX completion of this packet can trigger. Otherwise
4296 * the packet could potentially already be freed.
4298 * @skb: A socket buffer.
4300 static inline void skb_tx_timestamp(struct sk_buff *skb)
4302 skb_clone_tx_timestamp(skb);
4303 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP)
4304 skb_tstamp_tx(skb, NULL);
4308 * skb_complete_wifi_ack - deliver skb with wifi status
4310 * @skb: the original outgoing packet
4311 * @acked: ack status
4314 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
4316 __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
4317 __sum16 __skb_checksum_complete(struct sk_buff *skb);
4319 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
4321 return ((skb->ip_summed == CHECKSUM_UNNECESSARY) ||
4323 (skb->ip_summed == CHECKSUM_PARTIAL &&
4324 skb_checksum_start_offset(skb) >= 0));
4328 * skb_checksum_complete - Calculate checksum of an entire packet
4329 * @skb: packet to process
4331 * This function calculates the checksum over the entire packet plus
4332 * the value of skb->csum. The latter can be used to supply the
4333 * checksum of a pseudo header as used by TCP/UDP. It returns the
4336 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
4337 * this function can be used to verify that checksum on received
4338 * packets. In that case the function should return zero if the
4339 * checksum is correct. In particular, this function will return zero
4340 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
4341 * hardware has already verified the correctness of the checksum.
4343 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
4345 return skb_csum_unnecessary(skb) ?
4346 0 : __skb_checksum_complete(skb);
4349 static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb)
4351 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4352 if (skb->csum_level == 0)
4353 skb->ip_summed = CHECKSUM_NONE;
4359 static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb)
4361 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4362 if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
4364 } else if (skb->ip_summed == CHECKSUM_NONE) {
4365 skb->ip_summed = CHECKSUM_UNNECESSARY;
4366 skb->csum_level = 0;
4370 static inline void __skb_reset_checksum_unnecessary(struct sk_buff *skb)
4372 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
4373 skb->ip_summed = CHECKSUM_NONE;
4374 skb->csum_level = 0;
4378 /* Check if we need to perform checksum complete validation.
4380 * Returns true if checksum complete is needed, false otherwise
4381 * (either checksum is unnecessary or zero checksum is allowed).
4383 static inline bool __skb_checksum_validate_needed(struct sk_buff *skb,
4387 if (skb_csum_unnecessary(skb) || (zero_okay && !check)) {
4388 skb->csum_valid = 1;
4389 __skb_decr_checksum_unnecessary(skb);
4396 /* For small packets <= CHECKSUM_BREAK perform checksum complete directly
4399 #define CHECKSUM_BREAK 76
4401 /* Unset checksum-complete
4403 * Unset checksum complete can be done when packet is being modified
4404 * (uncompressed for instance) and checksum-complete value is
4407 static inline void skb_checksum_complete_unset(struct sk_buff *skb)
4409 if (skb->ip_summed == CHECKSUM_COMPLETE)
4410 skb->ip_summed = CHECKSUM_NONE;
4413 /* Validate (init) checksum based on checksum complete.
4416 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
4417 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
4418 * checksum is stored in skb->csum for use in __skb_checksum_complete
4419 * non-zero: value of invalid checksum
4422 static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
4426 if (skb->ip_summed == CHECKSUM_COMPLETE) {
4427 if (!csum_fold(csum_add(psum, skb->csum))) {
4428 skb->csum_valid = 1;
4435 if (complete || skb->len <= CHECKSUM_BREAK) {
4438 csum = __skb_checksum_complete(skb);
4439 skb->csum_valid = !csum;
4446 static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)
4451 /* Perform checksum validate (init). Note that this is a macro since we only
4452 * want to calculate the pseudo header which is an input function if necessary.
4453 * First we try to validate without any computation (checksum unnecessary) and
4454 * then calculate based on checksum complete calling the function to compute
4458 * 0: checksum is validated or try to in skb_checksum_complete
4459 * non-zero: value of invalid checksum
4461 #define __skb_checksum_validate(skb, proto, complete, \
4462 zero_okay, check, compute_pseudo) \
4464 __sum16 __ret = 0; \
4465 skb->csum_valid = 0; \
4466 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
4467 __ret = __skb_checksum_validate_complete(skb, \
4468 complete, compute_pseudo(skb, proto)); \
4472 #define skb_checksum_init(skb, proto, compute_pseudo) \
4473 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
4475 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
4476 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
4478 #define skb_checksum_validate(skb, proto, compute_pseudo) \
4479 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
4481 #define skb_checksum_validate_zero_check(skb, proto, check, \
4483 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
4485 #define skb_checksum_simple_validate(skb) \
4486 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
4488 static inline bool __skb_checksum_convert_check(struct sk_buff *skb)
4490 return (skb->ip_summed == CHECKSUM_NONE && skb->csum_valid);
4493 static inline void __skb_checksum_convert(struct sk_buff *skb, __wsum pseudo)
4495 skb->csum = ~pseudo;
4496 skb->ip_summed = CHECKSUM_COMPLETE;
4499 #define skb_checksum_try_convert(skb, proto, compute_pseudo) \
4501 if (__skb_checksum_convert_check(skb)) \
4502 __skb_checksum_convert(skb, compute_pseudo(skb, proto)); \
4505 static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr,
4506 u16 start, u16 offset)
4508 skb->ip_summed = CHECKSUM_PARTIAL;
4509 skb->csum_start = ((unsigned char *)ptr + start) - skb->head;
4510 skb->csum_offset = offset - start;
4513 /* Update skbuf and packet to reflect the remote checksum offload operation.
4514 * When called, ptr indicates the starting point for skb->csum when
4515 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
4516 * here, skb_postpull_rcsum is done so skb->csum start is ptr.
4518 static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr,
4519 int start, int offset, bool nopartial)
4524 skb_remcsum_adjust_partial(skb, ptr, start, offset);
4528 if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) {
4529 __skb_checksum_complete(skb);
4530 skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data);
4533 delta = remcsum_adjust(ptr, skb->csum, start, offset);
4535 /* Adjust skb->csum since we changed the packet */
4536 skb->csum = csum_add(skb->csum, delta);
4539 static inline struct nf_conntrack *skb_nfct(const struct sk_buff *skb)
4541 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4542 return (void *)(skb->_nfct & NFCT_PTRMASK);
4548 static inline unsigned long skb_get_nfct(const struct sk_buff *skb)
4550 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4557 static inline void skb_set_nfct(struct sk_buff *skb, unsigned long nfct)
4559 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4560 skb->slow_gro |= !!nfct;
4565 #ifdef CONFIG_SKB_EXTENSIONS
4567 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
4573 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
4576 #if IS_ENABLED(CONFIG_MPTCP)
4579 #if IS_ENABLED(CONFIG_MCTP_FLOWS)
4582 SKB_EXT_NUM, /* must be last */
4586 * struct skb_ext - sk_buff extensions
4587 * @refcnt: 1 on allocation, deallocated on 0
4588 * @offset: offset to add to @data to obtain extension address
4589 * @chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units
4590 * @data: start of extension data, variable sized
4592 * Note: offsets/lengths are stored in chunks of 8 bytes, this allows
4593 * to use 'u8' types while allowing up to 2kb worth of extension data.
4597 u8 offset[SKB_EXT_NUM]; /* in chunks of 8 bytes */
4598 u8 chunks; /* same */
4599 char data[] __aligned(8);
4602 struct skb_ext *__skb_ext_alloc(gfp_t flags);
4603 void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id,
4604 struct skb_ext *ext);
4605 void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id);
4606 void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id);
4607 void __skb_ext_put(struct skb_ext *ext);
4609 static inline void skb_ext_put(struct sk_buff *skb)
4611 if (skb->active_extensions)
4612 __skb_ext_put(skb->extensions);
4615 static inline void __skb_ext_copy(struct sk_buff *dst,
4616 const struct sk_buff *src)
4618 dst->active_extensions = src->active_extensions;
4620 if (src->active_extensions) {
4621 struct skb_ext *ext = src->extensions;
4623 refcount_inc(&ext->refcnt);
4624 dst->extensions = ext;
4628 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *src)
4631 __skb_ext_copy(dst, src);
4634 static inline bool __skb_ext_exist(const struct skb_ext *ext, enum skb_ext_id i)
4636 return !!ext->offset[i];
4639 static inline bool skb_ext_exist(const struct sk_buff *skb, enum skb_ext_id id)
4641 return skb->active_extensions & (1 << id);
4644 static inline void skb_ext_del(struct sk_buff *skb, enum skb_ext_id id)
4646 if (skb_ext_exist(skb, id))
4647 __skb_ext_del(skb, id);
4650 static inline void *skb_ext_find(const struct sk_buff *skb, enum skb_ext_id id)
4652 if (skb_ext_exist(skb, id)) {
4653 struct skb_ext *ext = skb->extensions;
4655 return (void *)ext + (ext->offset[id] << 3);
4661 static inline void skb_ext_reset(struct sk_buff *skb)
4663 if (unlikely(skb->active_extensions)) {
4664 __skb_ext_put(skb->extensions);
4665 skb->active_extensions = 0;
4669 static inline bool skb_has_extensions(struct sk_buff *skb)
4671 return unlikely(skb->active_extensions);
4674 static inline void skb_ext_put(struct sk_buff *skb) {}
4675 static inline void skb_ext_reset(struct sk_buff *skb) {}
4676 static inline void skb_ext_del(struct sk_buff *skb, int unused) {}
4677 static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {}
4678 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {}
4679 static inline bool skb_has_extensions(struct sk_buff *skb) { return false; }
4680 #endif /* CONFIG_SKB_EXTENSIONS */
4682 static inline void nf_reset_ct(struct sk_buff *skb)
4684 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4685 nf_conntrack_put(skb_nfct(skb));
4690 static inline void nf_reset_trace(struct sk_buff *skb)
4692 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
4697 static inline void ipvs_reset(struct sk_buff *skb)
4699 #if IS_ENABLED(CONFIG_IP_VS)
4700 skb->ipvs_property = 0;
4704 /* Note: This doesn't put any conntrack info in dst. */
4705 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src,
4708 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4709 dst->_nfct = src->_nfct;
4710 nf_conntrack_get(skb_nfct(src));
4712 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
4714 dst->nf_trace = src->nf_trace;
4718 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
4720 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4721 nf_conntrack_put(skb_nfct(dst));
4723 dst->slow_gro = src->slow_gro;
4724 __nf_copy(dst, src, true);
4727 #ifdef CONFIG_NETWORK_SECMARK
4728 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
4730 to->secmark = from->secmark;
4733 static inline void skb_init_secmark(struct sk_buff *skb)
4738 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
4741 static inline void skb_init_secmark(struct sk_buff *skb)
4745 static inline int secpath_exists(const struct sk_buff *skb)
4748 return skb_ext_exist(skb, SKB_EXT_SEC_PATH);
4754 static inline bool skb_irq_freeable(const struct sk_buff *skb)
4756 return !skb->destructor &&
4757 !secpath_exists(skb) &&
4759 !skb->_skb_refdst &&
4760 !skb_has_frag_list(skb);
4763 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
4765 skb->queue_mapping = queue_mapping;
4768 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
4770 return skb->queue_mapping;
4773 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
4775 to->queue_mapping = from->queue_mapping;
4778 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
4780 skb->queue_mapping = rx_queue + 1;
4783 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
4785 return skb->queue_mapping - 1;
4788 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
4790 return skb->queue_mapping != 0;
4793 static inline void skb_set_dst_pending_confirm(struct sk_buff *skb, u32 val)
4795 skb->dst_pending_confirm = val;
4798 static inline bool skb_get_dst_pending_confirm(const struct sk_buff *skb)
4800 return skb->dst_pending_confirm != 0;
4803 static inline struct sec_path *skb_sec_path(const struct sk_buff *skb)
4806 return skb_ext_find(skb, SKB_EXT_SEC_PATH);
4812 /* Keeps track of mac header offset relative to skb->head.
4813 * It is useful for TSO of Tunneling protocol. e.g. GRE.
4814 * For non-tunnel skb it points to skb_mac_header() and for
4815 * tunnel skb it points to outer mac header.
4816 * Keeps track of level of encapsulation of network headers.
4827 #define SKB_GSO_CB_OFFSET 32
4828 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_GSO_CB_OFFSET))
4830 static inline int skb_tnl_header_len(const struct sk_buff *inner_skb)
4832 return (skb_mac_header(inner_skb) - inner_skb->head) -
4833 SKB_GSO_CB(inner_skb)->mac_offset;
4836 static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra)
4838 int new_headroom, headroom;
4841 headroom = skb_headroom(skb);
4842 ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC);
4846 new_headroom = skb_headroom(skb);
4847 SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom);
4851 static inline void gso_reset_checksum(struct sk_buff *skb, __wsum res)
4853 /* Do not update partial checksums if remote checksum is enabled. */
4854 if (skb->remcsum_offload)
4857 SKB_GSO_CB(skb)->csum = res;
4858 SKB_GSO_CB(skb)->csum_start = skb_checksum_start(skb) - skb->head;
4861 /* Compute the checksum for a gso segment. First compute the checksum value
4862 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
4863 * then add in skb->csum (checksum from csum_start to end of packet).
4864 * skb->csum and csum_start are then updated to reflect the checksum of the
4865 * resultant packet starting from the transport header-- the resultant checksum
4866 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
4869 static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res)
4871 unsigned char *csum_start = skb_transport_header(skb);
4872 int plen = (skb->head + SKB_GSO_CB(skb)->csum_start) - csum_start;
4873 __wsum partial = SKB_GSO_CB(skb)->csum;
4875 SKB_GSO_CB(skb)->csum = res;
4876 SKB_GSO_CB(skb)->csum_start = csum_start - skb->head;
4878 return csum_fold(csum_partial(csum_start, plen, partial));
4881 static inline bool skb_is_gso(const struct sk_buff *skb)
4883 return skb_shinfo(skb)->gso_size;
4886 /* Note: Should be called only if skb_is_gso(skb) is true */
4887 static inline bool skb_is_gso_v6(const struct sk_buff *skb)
4889 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
4892 /* Note: Should be called only if skb_is_gso(skb) is true */
4893 static inline bool skb_is_gso_sctp(const struct sk_buff *skb)
4895 return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP;
4898 /* Note: Should be called only if skb_is_gso(skb) is true */
4899 static inline bool skb_is_gso_tcp(const struct sk_buff *skb)
4901 return skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6);
4904 static inline void skb_gso_reset(struct sk_buff *skb)
4906 skb_shinfo(skb)->gso_size = 0;
4907 skb_shinfo(skb)->gso_segs = 0;
4908 skb_shinfo(skb)->gso_type = 0;
4911 static inline void skb_increase_gso_size(struct skb_shared_info *shinfo,
4914 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
4916 shinfo->gso_size += increment;
4919 static inline void skb_decrease_gso_size(struct skb_shared_info *shinfo,
4922 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
4924 shinfo->gso_size -= decrement;
4927 void __skb_warn_lro_forwarding(const struct sk_buff *skb);
4929 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
4931 /* LRO sets gso_size but not gso_type, whereas if GSO is really
4932 * wanted then gso_type will be set. */
4933 const struct skb_shared_info *shinfo = skb_shinfo(skb);
4935 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
4936 unlikely(shinfo->gso_type == 0)) {
4937 __skb_warn_lro_forwarding(skb);
4943 static inline void skb_forward_csum(struct sk_buff *skb)
4945 /* Unfortunately we don't support this one. Any brave souls? */
4946 if (skb->ip_summed == CHECKSUM_COMPLETE)
4947 skb->ip_summed = CHECKSUM_NONE;
4951 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
4952 * @skb: skb to check
4954 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
4955 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
4956 * use this helper, to document places where we make this assertion.
4958 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
4960 DEBUG_NET_WARN_ON_ONCE(skb->ip_summed != CHECKSUM_NONE);
4963 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
4965 int skb_checksum_setup(struct sk_buff *skb, bool recalculate);
4966 struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb,
4967 unsigned int transport_len,
4968 __sum16(*skb_chkf)(struct sk_buff *skb));
4971 * skb_head_is_locked - Determine if the skb->head is locked down
4972 * @skb: skb to check
4974 * The head on skbs build around a head frag can be removed if they are
4975 * not cloned. This function returns true if the skb head is locked down
4976 * due to either being allocated via kmalloc, or by being a clone with
4977 * multiple references to the head.
4979 static inline bool skb_head_is_locked(const struct sk_buff *skb)
4981 return !skb->head_frag || skb_cloned(skb);
4984 /* Local Checksum Offload.
4985 * Compute outer checksum based on the assumption that the
4986 * inner checksum will be offloaded later.
4987 * See Documentation/networking/checksum-offloads.rst for
4988 * explanation of how this works.
4989 * Fill in outer checksum adjustment (e.g. with sum of outer
4990 * pseudo-header) before calling.
4991 * Also ensure that inner checksum is in linear data area.
4993 static inline __wsum lco_csum(struct sk_buff *skb)
4995 unsigned char *csum_start = skb_checksum_start(skb);
4996 unsigned char *l4_hdr = skb_transport_header(skb);
4999 /* Start with complement of inner checksum adjustment */
5000 partial = ~csum_unfold(*(__force __sum16 *)(csum_start +
5003 /* Add in checksum of our headers (incl. outer checksum
5004 * adjustment filled in by caller) and return result.
5006 return csum_partial(l4_hdr, csum_start - l4_hdr, partial);
5009 static inline bool skb_is_redirected(const struct sk_buff *skb)
5011 return skb->redirected;
5014 static inline void skb_set_redirected(struct sk_buff *skb, bool from_ingress)
5016 skb->redirected = 1;
5017 #ifdef CONFIG_NET_REDIRECT
5018 skb->from_ingress = from_ingress;
5019 if (skb->from_ingress)
5020 skb_clear_tstamp(skb);
5024 static inline void skb_reset_redirect(struct sk_buff *skb)
5026 skb->redirected = 0;
5029 static inline bool skb_csum_is_sctp(struct sk_buff *skb)
5031 return skb->csum_not_inet;
5034 static inline void skb_set_kcov_handle(struct sk_buff *skb,
5035 const u64 kcov_handle)
5038 skb->kcov_handle = kcov_handle;
5042 static inline u64 skb_get_kcov_handle(struct sk_buff *skb)
5045 return skb->kcov_handle;
5051 #ifdef CONFIG_PAGE_POOL
5052 static inline void skb_mark_for_recycle(struct sk_buff *skb)
5054 skb->pp_recycle = 1;
5058 #endif /* __KERNEL__ */
5059 #endif /* _LINUX_SKBUFF_H */