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 <linux/net.h>
27 #include <linux/textsearch.h>
28 #include <net/checksum.h>
29 #include <linux/rcupdate.h>
30 #include <linux/hrtimer.h>
31 #include <linux/dma-mapping.h>
32 #include <linux/netdev_features.h>
33 #include <linux/sched.h>
34 #include <linux/sched/clock.h>
35 #include <net/flow_dissector.h>
36 #include <linux/splice.h>
37 #include <linux/in6.h>
38 #include <linux/if_packet.h>
40 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
41 #include <linux/netfilter/nf_conntrack_common.h>
44 /* The interface for checksum offload between the stack and networking drivers
47 * A. IP checksum related features
49 * Drivers advertise checksum offload capabilities in the features of a device.
50 * From the stack's point of view these are capabilities offered by the driver,
51 * a driver typically only advertises features that it is capable of offloading
54 * The checksum related features are:
56 * NETIF_F_HW_CSUM - The driver (or its device) is able to compute one
57 * IP (one's complement) checksum for any combination
58 * of protocols or protocol layering. The checksum is
59 * computed and set in a packet per the CHECKSUM_PARTIAL
60 * interface (see below).
62 * NETIF_F_IP_CSUM - Driver (device) is only able to checksum plain
63 * TCP or UDP packets over IPv4. These are specifically
64 * unencapsulated packets of the form IPv4|TCP or
65 * IPv4|UDP where the Protocol field in the IPv4 header
66 * is TCP or UDP. The IPv4 header may contain IP options
67 * This feature cannot be set in features for a device
68 * with NETIF_F_HW_CSUM also set. This feature is being
69 * DEPRECATED (see below).
71 * NETIF_F_IPV6_CSUM - Driver (device) is only able to checksum plain
72 * TCP or UDP packets over IPv6. These are specifically
73 * unencapsulated packets of the form IPv6|TCP or
74 * IPv4|UDP where the Next Header field in the IPv6
75 * header is either TCP or UDP. IPv6 extension headers
76 * are not supported with this feature. This feature
77 * cannot be set in features for a device with
78 * NETIF_F_HW_CSUM also set. This feature is being
79 * DEPRECATED (see below).
81 * NETIF_F_RXCSUM - Driver (device) performs receive checksum offload.
82 * This flag is used only used to disable the RX checksum
83 * feature for a device. The stack will accept receive
84 * checksum indication in packets received on a device
85 * regardless of whether NETIF_F_RXCSUM is set.
87 * B. Checksumming of received packets by device. Indication of checksum
88 * verification is in set skb->ip_summed. Possible values are:
92 * Device did not checksum this packet e.g. due to lack of capabilities.
93 * The packet contains full (though not verified) checksum in packet but
94 * not in skb->csum. Thus, skb->csum is undefined in this case.
96 * CHECKSUM_UNNECESSARY:
98 * The hardware you're dealing with doesn't calculate the full checksum
99 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
100 * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY
101 * if their checksums are okay. skb->csum is still undefined in this case
102 * though. A driver or device must never modify the checksum field in the
103 * packet even if checksum is verified.
105 * CHECKSUM_UNNECESSARY is applicable to following protocols:
106 * TCP: IPv6 and IPv4.
107 * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
108 * zero UDP checksum for either IPv4 or IPv6, the networking stack
109 * may perform further validation in this case.
110 * GRE: only if the checksum is present in the header.
111 * SCTP: indicates the CRC in SCTP header has been validated.
112 * FCOE: indicates the CRC in FC frame has been validated.
114 * skb->csum_level indicates the number of consecutive checksums found in
115 * the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
116 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
117 * and a device is able to verify the checksums for UDP (possibly zero),
118 * GRE (checksum flag is set), and TCP-- skb->csum_level would be set to
119 * two. If the device were only able to verify the UDP checksum and not
120 * GRE, either because it doesn't support GRE checksum of because GRE
121 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
122 * not considered in this case).
126 * This is the most generic way. The device supplied checksum of the _whole_
127 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the
128 * hardware doesn't need to parse L3/L4 headers to implement this.
131 * - Even if device supports only some protocols, but is able to produce
132 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
133 * - CHECKSUM_COMPLETE is not applicable to SCTP and FCoE protocols.
137 * A checksum is set up to be offloaded to a device as described in the
138 * output description for CHECKSUM_PARTIAL. This may occur on a packet
139 * received directly from another Linux OS, e.g., a virtualized Linux kernel
140 * on the same host, or it may be set in the input path in GRO or remote
141 * checksum offload. For the purposes of checksum verification, the checksum
142 * referred to by skb->csum_start + skb->csum_offset and any preceding
143 * checksums in the packet are considered verified. Any checksums in the
144 * packet that are after the checksum being offloaded are not considered to
147 * C. Checksumming on transmit for non-GSO. The stack requests checksum offload
148 * in the skb->ip_summed for a packet. Values are:
152 * The driver is required to checksum the packet as seen by hard_start_xmit()
153 * from skb->csum_start up to the end, and to record/write the checksum at
154 * offset skb->csum_start + skb->csum_offset. A driver may verify that the
155 * csum_start and csum_offset values are valid values given the length and
156 * offset of the packet, however they should not attempt to validate that the
157 * checksum refers to a legitimate transport layer checksum-- it is the
158 * purview of the stack to validate that csum_start and csum_offset are set
161 * When the stack requests checksum offload for a packet, the driver MUST
162 * ensure that the checksum is set correctly. A driver can either offload the
163 * checksum calculation to the device, or call skb_checksum_help (in the case
164 * that the device does not support offload for a particular checksum).
166 * NETIF_F_IP_CSUM and NETIF_F_IPV6_CSUM are being deprecated in favor of
167 * NETIF_F_HW_CSUM. New devices should use NETIF_F_HW_CSUM to indicate
168 * checksum offload capability.
169 * skb_csum_hwoffload_help() can be called to resolve CHECKSUM_PARTIAL based
170 * on network device checksumming capabilities: if a packet does not match
171 * them, skb_checksum_help or skb_crc32c_help (depending on the value of
172 * csum_not_inet, see item D.) is called to resolve the checksum.
176 * The skb was already checksummed by the protocol, or a checksum is not
179 * CHECKSUM_UNNECESSARY:
181 * This has the same meaning on as CHECKSUM_NONE for checksum offload on
185 * Not used in checksum output. If a driver observes a packet with this value
186 * set in skbuff, if should treat as CHECKSUM_NONE being set.
188 * D. Non-IP checksum (CRC) offloads
190 * NETIF_F_SCTP_CRC - This feature indicates that a device is capable of
191 * offloading the SCTP CRC in a packet. To perform this offload the stack
192 * will set set csum_start and csum_offset accordingly, set ip_summed to
193 * CHECKSUM_PARTIAL and set csum_not_inet to 1, to provide an indication in
194 * the skbuff that the CHECKSUM_PARTIAL refers to CRC32c.
195 * A driver that supports both IP checksum offload and SCTP CRC32c offload
196 * must verify which offload is configured for a packet by testing the
197 * value of skb->csum_not_inet; skb_crc32c_csum_help is provided to resolve
198 * CHECKSUM_PARTIAL on skbs where csum_not_inet is set to 1.
200 * NETIF_F_FCOE_CRC - This feature indicates that a device is capable of
201 * offloading the FCOE CRC in a packet. To perform this offload the stack
202 * will set ip_summed to CHECKSUM_PARTIAL and set csum_start and csum_offset
203 * accordingly. Note the there is no indication in the skbuff that the
204 * CHECKSUM_PARTIAL refers to an FCOE checksum, a driver that supports
205 * both IP checksum offload and FCOE CRC offload must verify which offload
206 * is configured for a packet presumably by inspecting packet headers.
208 * E. Checksumming on output with GSO.
210 * In the case of a GSO packet (skb_is_gso(skb) is true), checksum offload
211 * is implied by the SKB_GSO_* flags in gso_type. Most obviously, if the
212 * gso_type is SKB_GSO_TCPV4 or SKB_GSO_TCPV6, TCP checksum offload as
213 * part of the GSO operation is implied. If a checksum is being offloaded
214 * with GSO then ip_summed is CHECKSUM_PARTIAL, csum_start and csum_offset
215 * are set to refer to the outermost checksum being offload (two offloaded
216 * checksums are possible with UDP encapsulation).
219 /* Don't change this without changing skb_csum_unnecessary! */
220 #define CHECKSUM_NONE 0
221 #define CHECKSUM_UNNECESSARY 1
222 #define CHECKSUM_COMPLETE 2
223 #define CHECKSUM_PARTIAL 3
225 /* Maximum value in skb->csum_level */
226 #define SKB_MAX_CSUM_LEVEL 3
228 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
229 #define SKB_WITH_OVERHEAD(X) \
230 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
231 #define SKB_MAX_ORDER(X, ORDER) \
232 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
233 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
234 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
236 /* return minimum truesize of one skb containing X bytes of data */
237 #define SKB_TRUESIZE(X) ((X) + \
238 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
239 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
243 struct pipe_inode_info;
250 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
251 struct nf_bridge_info {
253 BRNF_PROTO_UNCHANGED,
261 struct net_device *physindev;
263 /* always valid & non-NULL from FORWARD on, for physdev match */
264 struct net_device *physoutdev;
266 /* prerouting: detect dnat in orig/reply direction */
268 struct in6_addr ipv6_daddr;
270 /* after prerouting + nat detected: store original source
271 * mac since neigh resolution overwrites it, only used while
272 * skb is out in neigh layer.
274 char neigh_header[8];
279 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
280 /* Chain in tc_skb_ext will be used to share the tc chain with
281 * ovs recirc_id. It will be set to the current chain by tc
282 * and read by ovs to recirc_id.
289 struct sk_buff_head {
290 /* These two members must be first. */
291 struct sk_buff *next;
292 struct sk_buff *prev;
300 /* To allow 64K frame to be packed as single skb without frag_list we
301 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
302 * buffers which do not start on a page boundary.
304 * Since GRO uses frags we allocate at least 16 regardless of page
307 #if (65536/PAGE_SIZE + 1) < 16
308 #define MAX_SKB_FRAGS 16UL
310 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
312 extern int sysctl_max_skb_frags;
314 /* Set skb_shinfo(skb)->gso_size to this in case you want skb_segment to
315 * segment using its current segmentation instead.
317 #define GSO_BY_FRAGS 0xFFFF
319 typedef struct bio_vec skb_frag_t;
322 * skb_frag_size() - Returns the size of a skb fragment
323 * @frag: skb fragment
325 static inline unsigned int skb_frag_size(const skb_frag_t *frag)
331 * skb_frag_size_set() - Sets the size of a skb fragment
332 * @frag: skb fragment
333 * @size: size of fragment
335 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
341 * skb_frag_size_add() - Increments the size of a skb fragment by @delta
342 * @frag: skb fragment
343 * @delta: value to add
345 static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
347 frag->bv_len += delta;
351 * skb_frag_size_sub() - Decrements the size of a skb fragment by @delta
352 * @frag: skb fragment
353 * @delta: value to subtract
355 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
357 frag->bv_len -= delta;
361 * skb_frag_must_loop - Test if %p is a high memory page
362 * @p: fragment's page
364 static inline bool skb_frag_must_loop(struct page *p)
366 #if defined(CONFIG_HIGHMEM)
374 * skb_frag_foreach_page - loop over pages in a fragment
376 * @f: skb frag to operate on
377 * @f_off: offset from start of f->bv_page
378 * @f_len: length from f_off to loop over
379 * @p: (temp var) current page
380 * @p_off: (temp var) offset from start of current page,
381 * non-zero only on first page.
382 * @p_len: (temp var) length in current page,
383 * < PAGE_SIZE only on first and last page.
384 * @copied: (temp var) length so far, excluding current p_len.
386 * A fragment can hold a compound page, in which case per-page
387 * operations, notably kmap_atomic, must be called for each
390 #define skb_frag_foreach_page(f, f_off, f_len, p, p_off, p_len, copied) \
391 for (p = skb_frag_page(f) + ((f_off) >> PAGE_SHIFT), \
392 p_off = (f_off) & (PAGE_SIZE - 1), \
393 p_len = skb_frag_must_loop(p) ? \
394 min_t(u32, f_len, PAGE_SIZE - p_off) : f_len, \
397 copied += p_len, p++, p_off = 0, \
398 p_len = min_t(u32, f_len - copied, PAGE_SIZE)) \
400 #define HAVE_HW_TIME_STAMP
403 * struct skb_shared_hwtstamps - hardware time stamps
404 * @hwtstamp: hardware time stamp transformed into duration
405 * since arbitrary point in time
407 * Software time stamps generated by ktime_get_real() are stored in
410 * hwtstamps can only be compared against other hwtstamps from
413 * This structure is attached to packets as part of the
414 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
416 struct skb_shared_hwtstamps {
420 /* Definitions for tx_flags in struct skb_shared_info */
422 /* generate hardware time stamp */
423 SKBTX_HW_TSTAMP = 1 << 0,
425 /* generate software time stamp when queueing packet to NIC */
426 SKBTX_SW_TSTAMP = 1 << 1,
428 /* device driver is going to provide hardware time stamp */
429 SKBTX_IN_PROGRESS = 1 << 2,
431 /* device driver supports TX zero-copy buffers */
432 SKBTX_DEV_ZEROCOPY = 1 << 3,
434 /* generate wifi status information (where possible) */
435 SKBTX_WIFI_STATUS = 1 << 4,
437 /* This indicates at least one fragment might be overwritten
438 * (as in vmsplice(), sendfile() ...)
439 * If we need to compute a TX checksum, we'll need to copy
440 * all frags to avoid possible bad checksum
442 SKBTX_SHARED_FRAG = 1 << 5,
444 /* generate software time stamp when entering packet scheduling */
445 SKBTX_SCHED_TSTAMP = 1 << 6,
448 #define SKBTX_ZEROCOPY_FRAG (SKBTX_DEV_ZEROCOPY | SKBTX_SHARED_FRAG)
449 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
451 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
454 * The callback notifies userspace to release buffers when skb DMA is done in
455 * lower device, the skb last reference should be 0 when calling this.
456 * The zerocopy_success argument is true if zero copy transmit occurred,
457 * false on data copy or out of memory error caused by data copy attempt.
458 * The ctx field is used to track device context.
459 * The desc field is used to track userspace buffer index.
462 void (*callback)(struct ubuf_info *, bool zerocopy_success);
478 struct user_struct *user;
483 #define skb_uarg(SKB) ((struct ubuf_info *)(skb_shinfo(SKB)->destructor_arg))
485 int mm_account_pinned_pages(struct mmpin *mmp, size_t size);
486 void mm_unaccount_pinned_pages(struct mmpin *mmp);
488 struct ubuf_info *sock_zerocopy_alloc(struct sock *sk, size_t size);
489 struct ubuf_info *sock_zerocopy_realloc(struct sock *sk, size_t size,
490 struct ubuf_info *uarg);
492 static inline void sock_zerocopy_get(struct ubuf_info *uarg)
494 refcount_inc(&uarg->refcnt);
497 void sock_zerocopy_put(struct ubuf_info *uarg);
498 void sock_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref);
500 void sock_zerocopy_callback(struct ubuf_info *uarg, bool success);
502 int skb_zerocopy_iter_dgram(struct sk_buff *skb, struct msghdr *msg, int len);
503 int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
504 struct msghdr *msg, int len,
505 struct ubuf_info *uarg);
507 /* This data is invariant across clones and lives at
508 * the end of the header data, ie. at skb->end.
510 struct skb_shared_info {
515 unsigned short gso_size;
516 /* Warning: this field is not always filled in (UFO)! */
517 unsigned short gso_segs;
518 struct sk_buff *frag_list;
519 struct skb_shared_hwtstamps hwtstamps;
520 unsigned int gso_type;
524 * Warning : all fields before dataref are cleared in __alloc_skb()
528 /* Intermediate layers must ensure that destructor_arg
529 * remains valid until skb destructor */
530 void * destructor_arg;
532 /* must be last field, see pskb_expand_head() */
533 skb_frag_t frags[MAX_SKB_FRAGS];
536 /* We divide dataref into two halves. The higher 16 bits hold references
537 * to the payload part of skb->data. The lower 16 bits hold references to
538 * the entire skb->data. A clone of a headerless skb holds the length of
539 * the header in skb->hdr_len.
541 * All users must obey the rule that the skb->data reference count must be
542 * greater than or equal to the payload reference count.
544 * Holding a reference to the payload part means that the user does not
545 * care about modifications to the header part of skb->data.
547 #define SKB_DATAREF_SHIFT 16
548 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
552 SKB_FCLONE_UNAVAILABLE, /* skb has no fclone (from head_cache) */
553 SKB_FCLONE_ORIG, /* orig skb (from fclone_cache) */
554 SKB_FCLONE_CLONE, /* companion fclone skb (from fclone_cache) */
558 SKB_GSO_TCPV4 = 1 << 0,
560 /* This indicates the skb is from an untrusted source. */
561 SKB_GSO_DODGY = 1 << 1,
563 /* This indicates the tcp segment has CWR set. */
564 SKB_GSO_TCP_ECN = 1 << 2,
566 SKB_GSO_TCP_FIXEDID = 1 << 3,
568 SKB_GSO_TCPV6 = 1 << 4,
570 SKB_GSO_FCOE = 1 << 5,
572 SKB_GSO_GRE = 1 << 6,
574 SKB_GSO_GRE_CSUM = 1 << 7,
576 SKB_GSO_IPXIP4 = 1 << 8,
578 SKB_GSO_IPXIP6 = 1 << 9,
580 SKB_GSO_UDP_TUNNEL = 1 << 10,
582 SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
584 SKB_GSO_PARTIAL = 1 << 12,
586 SKB_GSO_TUNNEL_REMCSUM = 1 << 13,
588 SKB_GSO_SCTP = 1 << 14,
590 SKB_GSO_ESP = 1 << 15,
592 SKB_GSO_UDP = 1 << 16,
594 SKB_GSO_UDP_L4 = 1 << 17,
596 SKB_GSO_FRAGLIST = 1 << 18,
599 #if BITS_PER_LONG > 32
600 #define NET_SKBUFF_DATA_USES_OFFSET 1
603 #ifdef NET_SKBUFF_DATA_USES_OFFSET
604 typedef unsigned int sk_buff_data_t;
606 typedef unsigned char *sk_buff_data_t;
610 * struct sk_buff - socket buffer
611 * @next: Next buffer in list
612 * @prev: Previous buffer in list
613 * @tstamp: Time we arrived/left
614 * @skb_mstamp_ns: (aka @tstamp) earliest departure time; start point
615 * for retransmit timer
616 * @rbnode: RB tree node, alternative to next/prev for netem/tcp
618 * @sk: Socket we are owned by
619 * @ip_defrag_offset: (aka @sk) alternate use of @sk, used in
620 * fragmentation management
621 * @dev: Device we arrived on/are leaving by
622 * @dev_scratch: (aka @dev) alternate use of @dev when @dev would be %NULL
623 * @cb: Control buffer. Free for use by every layer. Put private vars here
624 * @_skb_refdst: destination entry (with norefcount bit)
625 * @sp: the security path, used for xfrm
626 * @len: Length of actual data
627 * @data_len: Data length
628 * @mac_len: Length of link layer header
629 * @hdr_len: writable header length of cloned skb
630 * @csum: Checksum (must include start/offset pair)
631 * @csum_start: Offset from skb->head where checksumming should start
632 * @csum_offset: Offset from csum_start where checksum should be stored
633 * @priority: Packet queueing priority
634 * @ignore_df: allow local fragmentation
635 * @cloned: Head may be cloned (check refcnt to be sure)
636 * @ip_summed: Driver fed us an IP checksum
637 * @nohdr: Payload reference only, must not modify header
638 * @pkt_type: Packet class
639 * @fclone: skbuff clone status
640 * @ipvs_property: skbuff is owned by ipvs
641 * @inner_protocol_type: whether the inner protocol is
642 * ENCAP_TYPE_ETHER or ENCAP_TYPE_IPPROTO
643 * @remcsum_offload: remote checksum offload is enabled
644 * @offload_fwd_mark: Packet was L2-forwarded in hardware
645 * @offload_l3_fwd_mark: Packet was L3-forwarded in hardware
646 * @tc_skip_classify: do not classify packet. set by IFB device
647 * @tc_at_ingress: used within tc_classify to distinguish in/egress
648 * @tc_redirected: packet was redirected by a tc action
649 * @tc_from_ingress: if tc_redirected, tc_at_ingress at time of redirect
650 * @peeked: this packet has been seen already, so stats have been
651 * done for it, don't do them again
652 * @nf_trace: netfilter packet trace flag
653 * @protocol: Packet protocol from driver
654 * @destructor: Destruct function
655 * @tcp_tsorted_anchor: list structure for TCP (tp->tsorted_sent_queue)
656 * @_nfct: Associated connection, if any (with nfctinfo bits)
657 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
658 * @skb_iif: ifindex of device we arrived on
659 * @tc_index: Traffic control index
660 * @hash: the packet hash
661 * @queue_mapping: Queue mapping for multiqueue devices
662 * @head_frag: skb was allocated from page fragments,
663 * not allocated by kmalloc() or vmalloc().
664 * @pfmemalloc: skbuff was allocated from PFMEMALLOC reserves
665 * @active_extensions: active extensions (skb_ext_id types)
666 * @ndisc_nodetype: router type (from link layer)
667 * @ooo_okay: allow the mapping of a socket to a queue to be changed
668 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
670 * @sw_hash: indicates hash was computed in software stack
671 * @wifi_acked_valid: wifi_acked was set
672 * @wifi_acked: whether frame was acked on wifi or not
673 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
674 * @encapsulation: indicates the inner headers in the skbuff are valid
675 * @encap_hdr_csum: software checksum is needed
676 * @csum_valid: checksum is already valid
677 * @csum_not_inet: use CRC32c to resolve CHECKSUM_PARTIAL
678 * @csum_complete_sw: checksum was completed by software
679 * @csum_level: indicates the number of consecutive checksums found in
680 * the packet minus one that have been verified as
681 * CHECKSUM_UNNECESSARY (max 3)
682 * @dst_pending_confirm: need to confirm neighbour
683 * @decrypted: Decrypted SKB
684 * @napi_id: id of the NAPI struct this skb came from
685 * @sender_cpu: (aka @napi_id) source CPU in XPS
686 * @secmark: security marking
687 * @mark: Generic packet mark
688 * @reserved_tailroom: (aka @mark) number of bytes of free space available
689 * at the tail of an sk_buff
690 * @vlan_present: VLAN tag is present
691 * @vlan_proto: vlan encapsulation protocol
692 * @vlan_tci: vlan tag control information
693 * @inner_protocol: Protocol (encapsulation)
694 * @inner_ipproto: (aka @inner_protocol) stores ipproto when
695 * skb->inner_protocol_type == ENCAP_TYPE_IPPROTO;
696 * @inner_transport_header: Inner transport layer header (encapsulation)
697 * @inner_network_header: Network layer header (encapsulation)
698 * @inner_mac_header: Link layer header (encapsulation)
699 * @transport_header: Transport layer header
700 * @network_header: Network layer header
701 * @mac_header: Link layer header
702 * @tail: Tail pointer
704 * @head: Head of buffer
705 * @data: Data head pointer
706 * @truesize: Buffer size
707 * @users: User count - see {datagram,tcp}.c
708 * @extensions: allocated extensions, valid if active_extensions is nonzero
714 /* These two members must be first. */
715 struct sk_buff *next;
716 struct sk_buff *prev;
719 struct net_device *dev;
720 /* Some protocols might use this space to store information,
721 * while device pointer would be NULL.
722 * UDP receive path is one user.
724 unsigned long dev_scratch;
727 struct rb_node rbnode; /* used in netem, ip4 defrag, and tcp stack */
728 struct list_head list;
733 int ip_defrag_offset;
738 u64 skb_mstamp_ns; /* earliest departure time */
741 * This is the control buffer. It is free to use for every
742 * layer. Please put your private variables there. If you
743 * want to keep them across layers you have to do a skb_clone()
744 * first. This is owned by whoever has the skb queued ATM.
746 char cb[48] __aligned(8);
750 unsigned long _skb_refdst;
751 void (*destructor)(struct sk_buff *skb);
753 struct list_head tcp_tsorted_anchor;
756 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
764 /* Following fields are _not_ copied in __copy_skb_header()
765 * Note that queue_mapping is here mostly to fill a hole.
769 /* if you move cloned around you also must adapt those constants */
770 #ifdef __BIG_ENDIAN_BITFIELD
771 #define CLONED_MASK (1 << 7)
773 #define CLONED_MASK 1
775 #define CLONED_OFFSET() offsetof(struct sk_buff, __cloned_offset)
778 __u8 __cloned_offset[0];
786 #ifdef CONFIG_SKB_EXTENSIONS
787 __u8 active_extensions;
789 /* fields enclosed in headers_start/headers_end are copied
790 * using a single memcpy() in __copy_skb_header()
793 __u32 headers_start[0];
796 /* if you move pkt_type around you also must adapt those constants */
797 #ifdef __BIG_ENDIAN_BITFIELD
798 #define PKT_TYPE_MAX (7 << 5)
800 #define PKT_TYPE_MAX 7
802 #define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset)
805 __u8 __pkt_type_offset[0];
815 __u8 wifi_acked_valid:1;
818 /* Indicates the inner headers are valid in the skbuff. */
819 __u8 encapsulation:1;
820 __u8 encap_hdr_csum:1;
823 #ifdef __BIG_ENDIAN_BITFIELD
824 #define PKT_VLAN_PRESENT_BIT 7
826 #define PKT_VLAN_PRESENT_BIT 0
828 #define PKT_VLAN_PRESENT_OFFSET() offsetof(struct sk_buff, __pkt_vlan_present_offset)
830 __u8 __pkt_vlan_present_offset[0];
833 __u8 csum_complete_sw:1;
835 __u8 csum_not_inet:1;
836 __u8 dst_pending_confirm:1;
837 #ifdef CONFIG_IPV6_NDISC_NODETYPE
838 __u8 ndisc_nodetype:2;
841 __u8 ipvs_property:1;
842 __u8 inner_protocol_type:1;
843 __u8 remcsum_offload:1;
844 #ifdef CONFIG_NET_SWITCHDEV
845 __u8 offload_fwd_mark:1;
846 __u8 offload_l3_fwd_mark:1;
848 #ifdef CONFIG_NET_CLS_ACT
849 __u8 tc_skip_classify:1;
850 __u8 tc_at_ingress:1;
851 __u8 tc_redirected:1;
852 __u8 tc_from_ingress:1;
854 #ifdef CONFIG_TLS_DEVICE
858 #ifdef CONFIG_NET_SCHED
859 __u16 tc_index; /* traffic control index */
874 #if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
876 unsigned int napi_id;
877 unsigned int sender_cpu;
880 #ifdef CONFIG_NETWORK_SECMARK
886 __u32 reserved_tailroom;
890 __be16 inner_protocol;
894 __u16 inner_transport_header;
895 __u16 inner_network_header;
896 __u16 inner_mac_header;
899 __u16 transport_header;
900 __u16 network_header;
904 __u32 headers_end[0];
907 /* These elements must be at the end, see alloc_skb() for details. */
912 unsigned int truesize;
915 #ifdef CONFIG_SKB_EXTENSIONS
916 /* only useable after checking ->active_extensions != 0 */
917 struct skb_ext *extensions;
923 * Handling routines are only of interest to the kernel
926 #define SKB_ALLOC_FCLONE 0x01
927 #define SKB_ALLOC_RX 0x02
928 #define SKB_ALLOC_NAPI 0x04
931 * skb_pfmemalloc - Test if the skb was allocated from PFMEMALLOC reserves
934 static inline bool skb_pfmemalloc(const struct sk_buff *skb)
936 return unlikely(skb->pfmemalloc);
940 * skb might have a dst pointer attached, refcounted or not.
941 * _skb_refdst low order bit is set if refcount was _not_ taken
943 #define SKB_DST_NOREF 1UL
944 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
947 * skb_dst - returns skb dst_entry
950 * Returns skb dst_entry, regardless of reference taken or not.
952 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
954 /* If refdst was not refcounted, check we still are in a
955 * rcu_read_lock section
957 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
958 !rcu_read_lock_held() &&
959 !rcu_read_lock_bh_held());
960 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
964 * skb_dst_set - sets skb dst
968 * Sets skb dst, assuming a reference was taken on dst and should
969 * be released by skb_dst_drop()
971 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
973 skb->_skb_refdst = (unsigned long)dst;
977 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
981 * Sets skb dst, assuming a reference was not taken on dst.
982 * If dst entry is cached, we do not take reference and dst_release
983 * will be avoided by refdst_drop. If dst entry is not cached, we take
984 * reference, so that last dst_release can destroy the dst immediately.
986 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst)
988 WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
989 skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF;
993 * skb_dst_is_noref - Test if skb dst isn't refcounted
996 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
998 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
1002 * skb_rtable - Returns the skb &rtable
1005 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
1007 return (struct rtable *)skb_dst(skb);
1010 /* For mangling skb->pkt_type from user space side from applications
1011 * such as nft, tc, etc, we only allow a conservative subset of
1012 * possible pkt_types to be set.
1014 static inline bool skb_pkt_type_ok(u32 ptype)
1016 return ptype <= PACKET_OTHERHOST;
1020 * skb_napi_id - Returns the skb's NAPI id
1023 static inline unsigned int skb_napi_id(const struct sk_buff *skb)
1025 #ifdef CONFIG_NET_RX_BUSY_POLL
1026 return skb->napi_id;
1033 * skb_unref - decrement the skb's reference count
1036 * Returns true if we can free the skb.
1038 static inline bool skb_unref(struct sk_buff *skb)
1042 if (likely(refcount_read(&skb->users) == 1))
1044 else if (likely(!refcount_dec_and_test(&skb->users)))
1050 void skb_release_head_state(struct sk_buff *skb);
1051 void kfree_skb(struct sk_buff *skb);
1052 void kfree_skb_list(struct sk_buff *segs);
1053 void skb_dump(const char *level, const struct sk_buff *skb, bool full_pkt);
1054 void skb_tx_error(struct sk_buff *skb);
1055 void consume_skb(struct sk_buff *skb);
1056 void __consume_stateless_skb(struct sk_buff *skb);
1057 void __kfree_skb(struct sk_buff *skb);
1058 extern struct kmem_cache *skbuff_head_cache;
1060 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
1061 bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
1062 bool *fragstolen, int *delta_truesize);
1064 struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags,
1066 struct sk_buff *__build_skb(void *data, unsigned int frag_size);
1067 struct sk_buff *build_skb(void *data, unsigned int frag_size);
1068 struct sk_buff *build_skb_around(struct sk_buff *skb,
1069 void *data, unsigned int frag_size);
1072 * alloc_skb - allocate a network buffer
1073 * @size: size to allocate
1074 * @priority: allocation mask
1076 * This function is a convenient wrapper around __alloc_skb().
1078 static inline struct sk_buff *alloc_skb(unsigned int size,
1081 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
1084 struct sk_buff *alloc_skb_with_frags(unsigned long header_len,
1085 unsigned long data_len,
1089 struct sk_buff *alloc_skb_for_msg(struct sk_buff *first);
1091 /* Layout of fast clones : [skb1][skb2][fclone_ref] */
1092 struct sk_buff_fclones {
1093 struct sk_buff skb1;
1095 struct sk_buff skb2;
1097 refcount_t fclone_ref;
1101 * skb_fclone_busy - check if fclone is busy
1105 * Returns true if skb is a fast clone, and its clone is not freed.
1106 * Some drivers call skb_orphan() in their ndo_start_xmit(),
1107 * so we also check that this didnt happen.
1109 static inline bool skb_fclone_busy(const struct sock *sk,
1110 const struct sk_buff *skb)
1112 const struct sk_buff_fclones *fclones;
1114 fclones = container_of(skb, struct sk_buff_fclones, skb1);
1116 return skb->fclone == SKB_FCLONE_ORIG &&
1117 refcount_read(&fclones->fclone_ref) > 1 &&
1118 fclones->skb2.sk == sk;
1122 * alloc_skb_fclone - allocate a network buffer from fclone cache
1123 * @size: size to allocate
1124 * @priority: allocation mask
1126 * This function is a convenient wrapper around __alloc_skb().
1128 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
1131 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
1134 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
1135 void skb_headers_offset_update(struct sk_buff *skb, int off);
1136 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
1137 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority);
1138 void skb_copy_header(struct sk_buff *new, const struct sk_buff *old);
1139 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority);
1140 struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
1141 gfp_t gfp_mask, bool fclone);
1142 static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom,
1145 return __pskb_copy_fclone(skb, headroom, gfp_mask, false);
1148 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask);
1149 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
1150 unsigned int headroom);
1151 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom,
1152 int newtailroom, gfp_t priority);
1153 int __must_check skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
1154 int offset, int len);
1155 int __must_check skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg,
1156 int offset, int len);
1157 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
1158 int __skb_pad(struct sk_buff *skb, int pad, bool free_on_error);
1161 * skb_pad - zero pad the tail of an skb
1162 * @skb: buffer to pad
1163 * @pad: space to pad
1165 * Ensure that a buffer is followed by a padding area that is zero
1166 * filled. Used by network drivers which may DMA or transfer data
1167 * beyond the buffer end onto the wire.
1169 * May return error in out of memory cases. The skb is freed on error.
1171 static inline int skb_pad(struct sk_buff *skb, int pad)
1173 return __skb_pad(skb, pad, true);
1175 #define dev_kfree_skb(a) consume_skb(a)
1177 int skb_append_pagefrags(struct sk_buff *skb, struct page *page,
1178 int offset, size_t size);
1180 struct skb_seq_state {
1184 __u32 stepped_offset;
1185 struct sk_buff *root_skb;
1186 struct sk_buff *cur_skb;
1190 void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
1191 unsigned int to, struct skb_seq_state *st);
1192 unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
1193 struct skb_seq_state *st);
1194 void skb_abort_seq_read(struct skb_seq_state *st);
1196 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
1197 unsigned int to, struct ts_config *config);
1200 * Packet hash types specify the type of hash in skb_set_hash.
1202 * Hash types refer to the protocol layer addresses which are used to
1203 * construct a packet's hash. The hashes are used to differentiate or identify
1204 * flows of the protocol layer for the hash type. Hash types are either
1205 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
1207 * Properties of hashes:
1209 * 1) Two packets in different flows have different hash values
1210 * 2) Two packets in the same flow should have the same hash value
1212 * A hash at a higher layer is considered to be more specific. A driver should
1213 * set the most specific hash possible.
1215 * A driver cannot indicate a more specific hash than the layer at which a hash
1216 * was computed. For instance an L3 hash cannot be set as an L4 hash.
1218 * A driver may indicate a hash level which is less specific than the
1219 * actual layer the hash was computed on. For instance, a hash computed
1220 * at L4 may be considered an L3 hash. This should only be done if the
1221 * driver can't unambiguously determine that the HW computed the hash at
1222 * the higher layer. Note that the "should" in the second property above
1225 enum pkt_hash_types {
1226 PKT_HASH_TYPE_NONE, /* Undefined type */
1227 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */
1228 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */
1229 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */
1232 static inline void skb_clear_hash(struct sk_buff *skb)
1239 static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
1242 skb_clear_hash(skb);
1246 __skb_set_hash(struct sk_buff *skb, __u32 hash, bool is_sw, bool is_l4)
1248 skb->l4_hash = is_l4;
1249 skb->sw_hash = is_sw;
1254 skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
1256 /* Used by drivers to set hash from HW */
1257 __skb_set_hash(skb, hash, false, type == PKT_HASH_TYPE_L4);
1261 __skb_set_sw_hash(struct sk_buff *skb, __u32 hash, bool is_l4)
1263 __skb_set_hash(skb, hash, true, is_l4);
1266 void __skb_get_hash(struct sk_buff *skb);
1267 u32 __skb_get_hash_symmetric(const struct sk_buff *skb);
1268 u32 skb_get_poff(const struct sk_buff *skb);
1269 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1270 const struct flow_keys_basic *keys, int hlen);
1271 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
1272 void *data, int hlen_proto);
1274 static inline __be32 skb_flow_get_ports(const struct sk_buff *skb,
1275 int thoff, u8 ip_proto)
1277 return __skb_flow_get_ports(skb, thoff, ip_proto, NULL, 0);
1280 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
1281 const struct flow_dissector_key *key,
1282 unsigned int key_count);
1285 int skb_flow_dissector_prog_query(const union bpf_attr *attr,
1286 union bpf_attr __user *uattr);
1287 int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr,
1288 struct bpf_prog *prog);
1290 int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr);
1292 static inline int skb_flow_dissector_prog_query(const union bpf_attr *attr,
1293 union bpf_attr __user *uattr)
1298 static inline int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr,
1299 struct bpf_prog *prog)
1304 static inline int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr)
1310 struct bpf_flow_dissector;
1311 bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
1312 __be16 proto, int nhoff, int hlen, unsigned int flags);
1314 bool __skb_flow_dissect(const struct net *net,
1315 const struct sk_buff *skb,
1316 struct flow_dissector *flow_dissector,
1317 void *target_container,
1318 void *data, __be16 proto, int nhoff, int hlen,
1319 unsigned int flags);
1321 static inline bool skb_flow_dissect(const struct sk_buff *skb,
1322 struct flow_dissector *flow_dissector,
1323 void *target_container, unsigned int flags)
1325 return __skb_flow_dissect(NULL, skb, flow_dissector,
1326 target_container, NULL, 0, 0, 0, flags);
1329 static inline bool skb_flow_dissect_flow_keys(const struct sk_buff *skb,
1330 struct flow_keys *flow,
1333 memset(flow, 0, sizeof(*flow));
1334 return __skb_flow_dissect(NULL, skb, &flow_keys_dissector,
1335 flow, NULL, 0, 0, 0, flags);
1339 skb_flow_dissect_flow_keys_basic(const struct net *net,
1340 const struct sk_buff *skb,
1341 struct flow_keys_basic *flow, void *data,
1342 __be16 proto, int nhoff, int hlen,
1345 memset(flow, 0, sizeof(*flow));
1346 return __skb_flow_dissect(net, skb, &flow_keys_basic_dissector, flow,
1347 data, proto, nhoff, hlen, flags);
1350 void skb_flow_dissect_meta(const struct sk_buff *skb,
1351 struct flow_dissector *flow_dissector,
1352 void *target_container);
1354 /* Gets a skb connection tracking info, ctinfo map should be a
1355 * a map of mapsize to translate enum ip_conntrack_info states
1359 skb_flow_dissect_ct(const struct sk_buff *skb,
1360 struct flow_dissector *flow_dissector,
1361 void *target_container,
1365 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
1366 struct flow_dissector *flow_dissector,
1367 void *target_container);
1369 static inline __u32 skb_get_hash(struct sk_buff *skb)
1371 if (!skb->l4_hash && !skb->sw_hash)
1372 __skb_get_hash(skb);
1377 static inline __u32 skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
1379 if (!skb->l4_hash && !skb->sw_hash) {
1380 struct flow_keys keys;
1381 __u32 hash = __get_hash_from_flowi6(fl6, &keys);
1383 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1389 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1390 const siphash_key_t *perturb);
1392 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb)
1397 static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
1399 to->hash = from->hash;
1400 to->sw_hash = from->sw_hash;
1401 to->l4_hash = from->l4_hash;
1404 static inline void skb_copy_decrypted(struct sk_buff *to,
1405 const struct sk_buff *from)
1407 #ifdef CONFIG_TLS_DEVICE
1408 to->decrypted = from->decrypted;
1412 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1413 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1415 return skb->head + skb->end;
1418 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1423 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
1428 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
1430 return skb->end - skb->head;
1435 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
1437 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
1439 return &skb_shinfo(skb)->hwtstamps;
1442 static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb)
1444 bool is_zcopy = skb && skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY;
1446 return is_zcopy ? skb_uarg(skb) : NULL;
1449 static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg,
1452 if (skb && uarg && !skb_zcopy(skb)) {
1453 if (unlikely(have_ref && *have_ref))
1456 sock_zerocopy_get(uarg);
1457 skb_shinfo(skb)->destructor_arg = uarg;
1458 skb_shinfo(skb)->tx_flags |= SKBTX_ZEROCOPY_FRAG;
1462 static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val)
1464 skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL);
1465 skb_shinfo(skb)->tx_flags |= SKBTX_ZEROCOPY_FRAG;
1468 static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb)
1470 return (uintptr_t) skb_shinfo(skb)->destructor_arg & 0x1UL;
1473 static inline void *skb_zcopy_get_nouarg(struct sk_buff *skb)
1475 return (void *)((uintptr_t) skb_shinfo(skb)->destructor_arg & ~0x1UL);
1478 /* Release a reference on a zerocopy structure */
1479 static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy)
1481 struct ubuf_info *uarg = skb_zcopy(skb);
1484 if (skb_zcopy_is_nouarg(skb)) {
1485 /* no notification callback */
1486 } else if (uarg->callback == sock_zerocopy_callback) {
1487 uarg->zerocopy = uarg->zerocopy && zerocopy;
1488 sock_zerocopy_put(uarg);
1490 uarg->callback(uarg, zerocopy);
1493 skb_shinfo(skb)->tx_flags &= ~SKBTX_ZEROCOPY_FRAG;
1497 /* Abort a zerocopy operation and revert zckey on error in send syscall */
1498 static inline void skb_zcopy_abort(struct sk_buff *skb)
1500 struct ubuf_info *uarg = skb_zcopy(skb);
1503 sock_zerocopy_put_abort(uarg, false);
1504 skb_shinfo(skb)->tx_flags &= ~SKBTX_ZEROCOPY_FRAG;
1508 static inline void skb_mark_not_on_list(struct sk_buff *skb)
1513 /* Iterate through singly-linked GSO fragments of an skb. */
1514 #define skb_list_walk_safe(first, skb, next_skb) \
1515 for ((skb) = (first), (next_skb) = (skb) ? (skb)->next : NULL; (skb); \
1516 (skb) = (next_skb), (next_skb) = (skb) ? (skb)->next : NULL)
1518 static inline void skb_list_del_init(struct sk_buff *skb)
1520 __list_del_entry(&skb->list);
1521 skb_mark_not_on_list(skb);
1525 * skb_queue_empty - check if a queue is empty
1528 * Returns true if the queue is empty, false otherwise.
1530 static inline int skb_queue_empty(const struct sk_buff_head *list)
1532 return list->next == (const struct sk_buff *) list;
1536 * skb_queue_empty_lockless - check if a queue is empty
1539 * Returns true if the queue is empty, false otherwise.
1540 * This variant can be used in lockless contexts.
1542 static inline bool skb_queue_empty_lockless(const struct sk_buff_head *list)
1544 return READ_ONCE(list->next) == (const struct sk_buff *) list;
1549 * skb_queue_is_last - check if skb is the last entry in the queue
1553 * Returns true if @skb is the last buffer on the list.
1555 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
1556 const struct sk_buff *skb)
1558 return skb->next == (const struct sk_buff *) list;
1562 * skb_queue_is_first - check if skb is the first entry in the queue
1566 * Returns true if @skb is the first buffer on the list.
1568 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
1569 const struct sk_buff *skb)
1571 return skb->prev == (const struct sk_buff *) list;
1575 * skb_queue_next - return the next packet in the queue
1577 * @skb: current buffer
1579 * Return the next packet in @list after @skb. It is only valid to
1580 * call this if skb_queue_is_last() evaluates to false.
1582 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
1583 const struct sk_buff *skb)
1585 /* This BUG_ON may seem severe, but if we just return then we
1586 * are going to dereference garbage.
1588 BUG_ON(skb_queue_is_last(list, skb));
1593 * skb_queue_prev - return the prev packet in the queue
1595 * @skb: current buffer
1597 * Return the prev packet in @list before @skb. It is only valid to
1598 * call this if skb_queue_is_first() evaluates to false.
1600 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
1601 const struct sk_buff *skb)
1603 /* This BUG_ON may seem severe, but if we just return then we
1604 * are going to dereference garbage.
1606 BUG_ON(skb_queue_is_first(list, skb));
1611 * skb_get - reference buffer
1612 * @skb: buffer to reference
1614 * Makes another reference to a socket buffer and returns a pointer
1617 static inline struct sk_buff *skb_get(struct sk_buff *skb)
1619 refcount_inc(&skb->users);
1624 * If users == 1, we are the only owner and can avoid redundant atomic changes.
1628 * skb_cloned - is the buffer a clone
1629 * @skb: buffer to check
1631 * Returns true if the buffer was generated with skb_clone() and is
1632 * one of multiple shared copies of the buffer. Cloned buffers are
1633 * shared data so must not be written to under normal circumstances.
1635 static inline int skb_cloned(const struct sk_buff *skb)
1637 return skb->cloned &&
1638 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
1641 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
1643 might_sleep_if(gfpflags_allow_blocking(pri));
1645 if (skb_cloned(skb))
1646 return pskb_expand_head(skb, 0, 0, pri);
1652 * skb_header_cloned - is the header a clone
1653 * @skb: buffer to check
1655 * Returns true if modifying the header part of the buffer requires
1656 * the data to be copied.
1658 static inline int skb_header_cloned(const struct sk_buff *skb)
1665 dataref = atomic_read(&skb_shinfo(skb)->dataref);
1666 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
1667 return dataref != 1;
1670 static inline int skb_header_unclone(struct sk_buff *skb, gfp_t pri)
1672 might_sleep_if(gfpflags_allow_blocking(pri));
1674 if (skb_header_cloned(skb))
1675 return pskb_expand_head(skb, 0, 0, pri);
1681 * __skb_header_release - release reference to header
1682 * @skb: buffer to operate on
1684 static inline void __skb_header_release(struct sk_buff *skb)
1687 atomic_set(&skb_shinfo(skb)->dataref, 1 + (1 << SKB_DATAREF_SHIFT));
1692 * skb_shared - is the buffer shared
1693 * @skb: buffer to check
1695 * Returns true if more than one person has a reference to this
1698 static inline int skb_shared(const struct sk_buff *skb)
1700 return refcount_read(&skb->users) != 1;
1704 * skb_share_check - check if buffer is shared and if so clone it
1705 * @skb: buffer to check
1706 * @pri: priority for memory allocation
1708 * If the buffer is shared the buffer is cloned and the old copy
1709 * drops a reference. A new clone with a single reference is returned.
1710 * If the buffer is not shared the original buffer is returned. When
1711 * being called from interrupt status or with spinlocks held pri must
1714 * NULL is returned on a memory allocation failure.
1716 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
1718 might_sleep_if(gfpflags_allow_blocking(pri));
1719 if (skb_shared(skb)) {
1720 struct sk_buff *nskb = skb_clone(skb, pri);
1732 * Copy shared buffers into a new sk_buff. We effectively do COW on
1733 * packets to handle cases where we have a local reader and forward
1734 * and a couple of other messy ones. The normal one is tcpdumping
1735 * a packet thats being forwarded.
1739 * skb_unshare - make a copy of a shared buffer
1740 * @skb: buffer to check
1741 * @pri: priority for memory allocation
1743 * If the socket buffer is a clone then this function creates a new
1744 * copy of the data, drops a reference count on the old copy and returns
1745 * the new copy with the reference count at 1. If the buffer is not a clone
1746 * the original buffer is returned. When called with a spinlock held or
1747 * from interrupt state @pri must be %GFP_ATOMIC
1749 * %NULL is returned on a memory allocation failure.
1751 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
1754 might_sleep_if(gfpflags_allow_blocking(pri));
1755 if (skb_cloned(skb)) {
1756 struct sk_buff *nskb = skb_copy(skb, pri);
1758 /* Free our shared copy */
1769 * skb_peek - peek at the head of an &sk_buff_head
1770 * @list_: list to peek at
1772 * Peek an &sk_buff. Unlike most other operations you _MUST_
1773 * be careful with this one. A peek leaves the buffer on the
1774 * list and someone else may run off with it. You must hold
1775 * the appropriate locks or have a private queue to do this.
1777 * Returns %NULL for an empty list or a pointer to the head element.
1778 * The reference count is not incremented and the reference is therefore
1779 * volatile. Use with caution.
1781 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
1783 struct sk_buff *skb = list_->next;
1785 if (skb == (struct sk_buff *)list_)
1791 * __skb_peek - peek at the head of a non-empty &sk_buff_head
1792 * @list_: list to peek at
1794 * Like skb_peek(), but the caller knows that the list is not empty.
1796 static inline struct sk_buff *__skb_peek(const struct sk_buff_head *list_)
1802 * skb_peek_next - peek skb following the given one from a queue
1803 * @skb: skb to start from
1804 * @list_: list to peek at
1806 * Returns %NULL when the end of the list is met or a pointer to the
1807 * next element. The reference count is not incremented and the
1808 * reference is therefore volatile. Use with caution.
1810 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
1811 const struct sk_buff_head *list_)
1813 struct sk_buff *next = skb->next;
1815 if (next == (struct sk_buff *)list_)
1821 * skb_peek_tail - peek at the tail of an &sk_buff_head
1822 * @list_: list to peek at
1824 * Peek an &sk_buff. Unlike most other operations you _MUST_
1825 * be careful with this one. A peek leaves the buffer on the
1826 * list and someone else may run off with it. You must hold
1827 * the appropriate locks or have a private queue to do this.
1829 * Returns %NULL for an empty list or a pointer to the tail element.
1830 * The reference count is not incremented and the reference is therefore
1831 * volatile. Use with caution.
1833 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
1835 struct sk_buff *skb = READ_ONCE(list_->prev);
1837 if (skb == (struct sk_buff *)list_)
1844 * skb_queue_len - get queue length
1845 * @list_: list to measure
1847 * Return the length of an &sk_buff queue.
1849 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
1855 * skb_queue_len_lockless - get queue length
1856 * @list_: list to measure
1858 * Return the length of an &sk_buff queue.
1859 * This variant can be used in lockless contexts.
1861 static inline __u32 skb_queue_len_lockless(const struct sk_buff_head *list_)
1863 return READ_ONCE(list_->qlen);
1867 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1868 * @list: queue to initialize
1870 * This initializes only the list and queue length aspects of
1871 * an sk_buff_head object. This allows to initialize the list
1872 * aspects of an sk_buff_head without reinitializing things like
1873 * the spinlock. It can also be used for on-stack sk_buff_head
1874 * objects where the spinlock is known to not be used.
1876 static inline void __skb_queue_head_init(struct sk_buff_head *list)
1878 list->prev = list->next = (struct sk_buff *)list;
1883 * This function creates a split out lock class for each invocation;
1884 * this is needed for now since a whole lot of users of the skb-queue
1885 * infrastructure in drivers have different locking usage (in hardirq)
1886 * than the networking core (in softirq only). In the long run either the
1887 * network layer or drivers should need annotation to consolidate the
1888 * main types of usage into 3 classes.
1890 static inline void skb_queue_head_init(struct sk_buff_head *list)
1892 spin_lock_init(&list->lock);
1893 __skb_queue_head_init(list);
1896 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
1897 struct lock_class_key *class)
1899 skb_queue_head_init(list);
1900 lockdep_set_class(&list->lock, class);
1904 * Insert an sk_buff on a list.
1906 * The "__skb_xxxx()" functions are the non-atomic ones that
1907 * can only be called with interrupts disabled.
1909 static inline void __skb_insert(struct sk_buff *newsk,
1910 struct sk_buff *prev, struct sk_buff *next,
1911 struct sk_buff_head *list)
1913 /* See skb_queue_empty_lockless() and skb_peek_tail()
1914 * for the opposite READ_ONCE()
1916 WRITE_ONCE(newsk->next, next);
1917 WRITE_ONCE(newsk->prev, prev);
1918 WRITE_ONCE(next->prev, newsk);
1919 WRITE_ONCE(prev->next, newsk);
1923 static inline void __skb_queue_splice(const struct sk_buff_head *list,
1924 struct sk_buff *prev,
1925 struct sk_buff *next)
1927 struct sk_buff *first = list->next;
1928 struct sk_buff *last = list->prev;
1930 WRITE_ONCE(first->prev, prev);
1931 WRITE_ONCE(prev->next, first);
1933 WRITE_ONCE(last->next, next);
1934 WRITE_ONCE(next->prev, last);
1938 * skb_queue_splice - join two skb lists, this is designed for stacks
1939 * @list: the new list to add
1940 * @head: the place to add it in the first list
1942 static inline void skb_queue_splice(const struct sk_buff_head *list,
1943 struct sk_buff_head *head)
1945 if (!skb_queue_empty(list)) {
1946 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1947 head->qlen += list->qlen;
1952 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1953 * @list: the new list to add
1954 * @head: the place to add it in the first list
1956 * The list at @list is reinitialised
1958 static inline void skb_queue_splice_init(struct sk_buff_head *list,
1959 struct sk_buff_head *head)
1961 if (!skb_queue_empty(list)) {
1962 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1963 head->qlen += list->qlen;
1964 __skb_queue_head_init(list);
1969 * skb_queue_splice_tail - join two skb lists, each list being a queue
1970 * @list: the new list to add
1971 * @head: the place to add it in the first list
1973 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1974 struct sk_buff_head *head)
1976 if (!skb_queue_empty(list)) {
1977 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1978 head->qlen += list->qlen;
1983 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1984 * @list: the new list to add
1985 * @head: the place to add it in the first list
1987 * Each of the lists is a queue.
1988 * The list at @list is reinitialised
1990 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
1991 struct sk_buff_head *head)
1993 if (!skb_queue_empty(list)) {
1994 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1995 head->qlen += list->qlen;
1996 __skb_queue_head_init(list);
2001 * __skb_queue_after - queue a buffer at the list head
2002 * @list: list to use
2003 * @prev: place after this buffer
2004 * @newsk: buffer to queue
2006 * Queue a buffer int the middle of a list. This function takes no locks
2007 * and you must therefore hold required locks before calling it.
2009 * A buffer cannot be placed on two lists at the same time.
2011 static inline void __skb_queue_after(struct sk_buff_head *list,
2012 struct sk_buff *prev,
2013 struct sk_buff *newsk)
2015 __skb_insert(newsk, prev, prev->next, list);
2018 void skb_append(struct sk_buff *old, struct sk_buff *newsk,
2019 struct sk_buff_head *list);
2021 static inline void __skb_queue_before(struct sk_buff_head *list,
2022 struct sk_buff *next,
2023 struct sk_buff *newsk)
2025 __skb_insert(newsk, next->prev, next, list);
2029 * __skb_queue_head - queue a buffer at the list head
2030 * @list: list to use
2031 * @newsk: buffer to queue
2033 * Queue a buffer at the start of a list. This function takes no locks
2034 * and you must therefore hold required locks before calling it.
2036 * A buffer cannot be placed on two lists at the same time.
2038 static inline void __skb_queue_head(struct sk_buff_head *list,
2039 struct sk_buff *newsk)
2041 __skb_queue_after(list, (struct sk_buff *)list, newsk);
2043 void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
2046 * __skb_queue_tail - queue a buffer at the list tail
2047 * @list: list to use
2048 * @newsk: buffer to queue
2050 * Queue a buffer at the end of a list. This function takes no locks
2051 * and you must therefore hold required locks before calling it.
2053 * A buffer cannot be placed on two lists at the same time.
2055 static inline void __skb_queue_tail(struct sk_buff_head *list,
2056 struct sk_buff *newsk)
2058 __skb_queue_before(list, (struct sk_buff *)list, newsk);
2060 void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
2063 * remove sk_buff from list. _Must_ be called atomically, and with
2066 void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
2067 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
2069 struct sk_buff *next, *prev;
2071 WRITE_ONCE(list->qlen, list->qlen - 1);
2074 skb->next = skb->prev = NULL;
2075 WRITE_ONCE(next->prev, prev);
2076 WRITE_ONCE(prev->next, next);
2080 * __skb_dequeue - remove from the head of the queue
2081 * @list: list to dequeue from
2083 * Remove the head of the list. This function does not take any locks
2084 * so must be used with appropriate locks held only. The head item is
2085 * returned or %NULL if the list is empty.
2087 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
2089 struct sk_buff *skb = skb_peek(list);
2091 __skb_unlink(skb, list);
2094 struct sk_buff *skb_dequeue(struct sk_buff_head *list);
2097 * __skb_dequeue_tail - remove from the tail of the queue
2098 * @list: list to dequeue from
2100 * Remove the tail of the list. This function does not take any locks
2101 * so must be used with appropriate locks held only. The tail item is
2102 * returned or %NULL if the list is empty.
2104 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
2106 struct sk_buff *skb = skb_peek_tail(list);
2108 __skb_unlink(skb, list);
2111 struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
2114 static inline bool skb_is_nonlinear(const struct sk_buff *skb)
2116 return skb->data_len;
2119 static inline unsigned int skb_headlen(const struct sk_buff *skb)
2121 return skb->len - skb->data_len;
2124 static inline unsigned int __skb_pagelen(const struct sk_buff *skb)
2126 unsigned int i, len = 0;
2128 for (i = skb_shinfo(skb)->nr_frags - 1; (int)i >= 0; i--)
2129 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
2133 static inline unsigned int skb_pagelen(const struct sk_buff *skb)
2135 return skb_headlen(skb) + __skb_pagelen(skb);
2139 * __skb_fill_page_desc - initialise a paged fragment in an skb
2140 * @skb: buffer containing fragment to be initialised
2141 * @i: paged fragment index to initialise
2142 * @page: the page to use for this fragment
2143 * @off: the offset to the data with @page
2144 * @size: the length of the data
2146 * Initialises the @i'th fragment of @skb to point to &size bytes at
2147 * offset @off within @page.
2149 * Does not take any additional reference on the fragment.
2151 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
2152 struct page *page, int off, int size)
2154 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
2157 * Propagate page pfmemalloc to the skb if we can. The problem is
2158 * that not all callers have unique ownership of the page but rely
2159 * on page_is_pfmemalloc doing the right thing(tm).
2161 frag->bv_page = page;
2162 frag->bv_offset = off;
2163 skb_frag_size_set(frag, size);
2165 page = compound_head(page);
2166 if (page_is_pfmemalloc(page))
2167 skb->pfmemalloc = true;
2171 * skb_fill_page_desc - initialise a paged fragment in an skb
2172 * @skb: buffer containing fragment to be initialised
2173 * @i: paged fragment index to initialise
2174 * @page: the page to use for this fragment
2175 * @off: the offset to the data with @page
2176 * @size: the length of the data
2178 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
2179 * @skb to point to @size bytes at offset @off within @page. In
2180 * addition updates @skb such that @i is the last fragment.
2182 * Does not take any additional reference on the fragment.
2184 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
2185 struct page *page, int off, int size)
2187 __skb_fill_page_desc(skb, i, page, off, size);
2188 skb_shinfo(skb)->nr_frags = i + 1;
2191 void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
2192 int size, unsigned int truesize);
2194 void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
2195 unsigned int truesize);
2197 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
2199 #ifdef NET_SKBUFF_DATA_USES_OFFSET
2200 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2202 return skb->head + skb->tail;
2205 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2207 skb->tail = skb->data - skb->head;
2210 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2212 skb_reset_tail_pointer(skb);
2213 skb->tail += offset;
2216 #else /* NET_SKBUFF_DATA_USES_OFFSET */
2217 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
2222 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
2224 skb->tail = skb->data;
2227 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
2229 skb->tail = skb->data + offset;
2232 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
2235 * Add data to an sk_buff
2237 void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
2238 void *skb_put(struct sk_buff *skb, unsigned int len);
2239 static inline void *__skb_put(struct sk_buff *skb, unsigned int len)
2241 void *tmp = skb_tail_pointer(skb);
2242 SKB_LINEAR_ASSERT(skb);
2248 static inline void *__skb_put_zero(struct sk_buff *skb, unsigned int len)
2250 void *tmp = __skb_put(skb, len);
2252 memset(tmp, 0, len);
2256 static inline void *__skb_put_data(struct sk_buff *skb, const void *data,
2259 void *tmp = __skb_put(skb, len);
2261 memcpy(tmp, data, len);
2265 static inline void __skb_put_u8(struct sk_buff *skb, u8 val)
2267 *(u8 *)__skb_put(skb, 1) = val;
2270 static inline void *skb_put_zero(struct sk_buff *skb, unsigned int len)
2272 void *tmp = skb_put(skb, len);
2274 memset(tmp, 0, len);
2279 static inline void *skb_put_data(struct sk_buff *skb, const void *data,
2282 void *tmp = skb_put(skb, len);
2284 memcpy(tmp, data, len);
2289 static inline void skb_put_u8(struct sk_buff *skb, u8 val)
2291 *(u8 *)skb_put(skb, 1) = val;
2294 void *skb_push(struct sk_buff *skb, unsigned int len);
2295 static inline void *__skb_push(struct sk_buff *skb, unsigned int len)
2302 void *skb_pull(struct sk_buff *skb, unsigned int len);
2303 static inline void *__skb_pull(struct sk_buff *skb, unsigned int len)
2306 BUG_ON(skb->len < skb->data_len);
2307 return skb->data += len;
2310 static inline void *skb_pull_inline(struct sk_buff *skb, unsigned int len)
2312 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
2315 void *__pskb_pull_tail(struct sk_buff *skb, int delta);
2317 static inline void *__pskb_pull(struct sk_buff *skb, unsigned int len)
2319 if (len > skb_headlen(skb) &&
2320 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
2323 return skb->data += len;
2326 static inline void *pskb_pull(struct sk_buff *skb, unsigned int len)
2328 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
2331 static inline bool pskb_may_pull(struct sk_buff *skb, unsigned int len)
2333 if (likely(len <= skb_headlen(skb)))
2335 if (unlikely(len > skb->len))
2337 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
2340 void skb_condense(struct sk_buff *skb);
2343 * skb_headroom - bytes at buffer head
2344 * @skb: buffer to check
2346 * Return the number of bytes of free space at the head of an &sk_buff.
2348 static inline unsigned int skb_headroom(const struct sk_buff *skb)
2350 return skb->data - skb->head;
2354 * skb_tailroom - bytes at buffer end
2355 * @skb: buffer to check
2357 * Return the number of bytes of free space at the tail of an sk_buff
2359 static inline int skb_tailroom(const struct sk_buff *skb)
2361 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
2365 * skb_availroom - bytes at buffer end
2366 * @skb: buffer to check
2368 * Return the number of bytes of free space at the tail of an sk_buff
2369 * allocated by sk_stream_alloc()
2371 static inline int skb_availroom(const struct sk_buff *skb)
2373 if (skb_is_nonlinear(skb))
2376 return skb->end - skb->tail - skb->reserved_tailroom;
2380 * skb_reserve - adjust headroom
2381 * @skb: buffer to alter
2382 * @len: bytes to move
2384 * Increase the headroom of an empty &sk_buff by reducing the tail
2385 * room. This is only allowed for an empty buffer.
2387 static inline void skb_reserve(struct sk_buff *skb, int len)
2394 * skb_tailroom_reserve - adjust reserved_tailroom
2395 * @skb: buffer to alter
2396 * @mtu: maximum amount of headlen permitted
2397 * @needed_tailroom: minimum amount of reserved_tailroom
2399 * Set reserved_tailroom so that headlen can be as large as possible but
2400 * not larger than mtu and tailroom cannot be smaller than
2402 * The required headroom should already have been reserved before using
2405 static inline void skb_tailroom_reserve(struct sk_buff *skb, unsigned int mtu,
2406 unsigned int needed_tailroom)
2408 SKB_LINEAR_ASSERT(skb);
2409 if (mtu < skb_tailroom(skb) - needed_tailroom)
2410 /* use at most mtu */
2411 skb->reserved_tailroom = skb_tailroom(skb) - mtu;
2413 /* use up to all available space */
2414 skb->reserved_tailroom = needed_tailroom;
2417 #define ENCAP_TYPE_ETHER 0
2418 #define ENCAP_TYPE_IPPROTO 1
2420 static inline void skb_set_inner_protocol(struct sk_buff *skb,
2423 skb->inner_protocol = protocol;
2424 skb->inner_protocol_type = ENCAP_TYPE_ETHER;
2427 static inline void skb_set_inner_ipproto(struct sk_buff *skb,
2430 skb->inner_ipproto = ipproto;
2431 skb->inner_protocol_type = ENCAP_TYPE_IPPROTO;
2434 static inline void skb_reset_inner_headers(struct sk_buff *skb)
2436 skb->inner_mac_header = skb->mac_header;
2437 skb->inner_network_header = skb->network_header;
2438 skb->inner_transport_header = skb->transport_header;
2441 static inline void skb_reset_mac_len(struct sk_buff *skb)
2443 skb->mac_len = skb->network_header - skb->mac_header;
2446 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
2449 return skb->head + skb->inner_transport_header;
2452 static inline int skb_inner_transport_offset(const struct sk_buff *skb)
2454 return skb_inner_transport_header(skb) - skb->data;
2457 static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
2459 skb->inner_transport_header = skb->data - skb->head;
2462 static inline void skb_set_inner_transport_header(struct sk_buff *skb,
2465 skb_reset_inner_transport_header(skb);
2466 skb->inner_transport_header += offset;
2469 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
2471 return skb->head + skb->inner_network_header;
2474 static inline void skb_reset_inner_network_header(struct sk_buff *skb)
2476 skb->inner_network_header = skb->data - skb->head;
2479 static inline void skb_set_inner_network_header(struct sk_buff *skb,
2482 skb_reset_inner_network_header(skb);
2483 skb->inner_network_header += offset;
2486 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
2488 return skb->head + skb->inner_mac_header;
2491 static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
2493 skb->inner_mac_header = skb->data - skb->head;
2496 static inline void skb_set_inner_mac_header(struct sk_buff *skb,
2499 skb_reset_inner_mac_header(skb);
2500 skb->inner_mac_header += offset;
2502 static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
2504 return skb->transport_header != (typeof(skb->transport_header))~0U;
2507 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
2509 return skb->head + skb->transport_header;
2512 static inline void skb_reset_transport_header(struct sk_buff *skb)
2514 skb->transport_header = skb->data - skb->head;
2517 static inline void skb_set_transport_header(struct sk_buff *skb,
2520 skb_reset_transport_header(skb);
2521 skb->transport_header += offset;
2524 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
2526 return skb->head + skb->network_header;
2529 static inline void skb_reset_network_header(struct sk_buff *skb)
2531 skb->network_header = skb->data - skb->head;
2534 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
2536 skb_reset_network_header(skb);
2537 skb->network_header += offset;
2540 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
2542 return skb->head + skb->mac_header;
2545 static inline int skb_mac_offset(const struct sk_buff *skb)
2547 return skb_mac_header(skb) - skb->data;
2550 static inline u32 skb_mac_header_len(const struct sk_buff *skb)
2552 return skb->network_header - skb->mac_header;
2555 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
2557 return skb->mac_header != (typeof(skb->mac_header))~0U;
2560 static inline void skb_reset_mac_header(struct sk_buff *skb)
2562 skb->mac_header = skb->data - skb->head;
2565 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
2567 skb_reset_mac_header(skb);
2568 skb->mac_header += offset;
2571 static inline void skb_pop_mac_header(struct sk_buff *skb)
2573 skb->mac_header = skb->network_header;
2576 static inline void skb_probe_transport_header(struct sk_buff *skb)
2578 struct flow_keys_basic keys;
2580 if (skb_transport_header_was_set(skb))
2583 if (skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
2585 skb_set_transport_header(skb, keys.control.thoff);
2588 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
2590 if (skb_mac_header_was_set(skb)) {
2591 const unsigned char *old_mac = skb_mac_header(skb);
2593 skb_set_mac_header(skb, -skb->mac_len);
2594 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
2598 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
2600 return skb->csum_start - skb_headroom(skb);
2603 static inline unsigned char *skb_checksum_start(const struct sk_buff *skb)
2605 return skb->head + skb->csum_start;
2608 static inline int skb_transport_offset(const struct sk_buff *skb)
2610 return skb_transport_header(skb) - skb->data;
2613 static inline u32 skb_network_header_len(const struct sk_buff *skb)
2615 return skb->transport_header - skb->network_header;
2618 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb)
2620 return skb->inner_transport_header - skb->inner_network_header;
2623 static inline int skb_network_offset(const struct sk_buff *skb)
2625 return skb_network_header(skb) - skb->data;
2628 static inline int skb_inner_network_offset(const struct sk_buff *skb)
2630 return skb_inner_network_header(skb) - skb->data;
2633 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
2635 return pskb_may_pull(skb, skb_network_offset(skb) + len);
2639 * CPUs often take a performance hit when accessing unaligned memory
2640 * locations. The actual performance hit varies, it can be small if the
2641 * hardware handles it or large if we have to take an exception and fix it
2644 * Since an ethernet header is 14 bytes network drivers often end up with
2645 * the IP header at an unaligned offset. The IP header can be aligned by
2646 * shifting the start of the packet by 2 bytes. Drivers should do this
2649 * skb_reserve(skb, NET_IP_ALIGN);
2651 * The downside to this alignment of the IP header is that the DMA is now
2652 * unaligned. On some architectures the cost of an unaligned DMA is high
2653 * and this cost outweighs the gains made by aligning the IP header.
2655 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
2658 #ifndef NET_IP_ALIGN
2659 #define NET_IP_ALIGN 2
2663 * The networking layer reserves some headroom in skb data (via
2664 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
2665 * the header has to grow. In the default case, if the header has to grow
2666 * 32 bytes or less we avoid the reallocation.
2668 * Unfortunately this headroom changes the DMA alignment of the resulting
2669 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
2670 * on some architectures. An architecture can override this value,
2671 * perhaps setting it to a cacheline in size (since that will maintain
2672 * cacheline alignment of the DMA). It must be a power of 2.
2674 * Various parts of the networking layer expect at least 32 bytes of
2675 * headroom, you should not reduce this.
2677 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
2678 * to reduce average number of cache lines per packet.
2679 * get_rps_cpus() for example only access one 64 bytes aligned block :
2680 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
2683 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
2686 int ___pskb_trim(struct sk_buff *skb, unsigned int len);
2688 static inline void __skb_set_length(struct sk_buff *skb, unsigned int len)
2690 if (WARN_ON(skb_is_nonlinear(skb)))
2693 skb_set_tail_pointer(skb, len);
2696 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
2698 __skb_set_length(skb, len);
2701 void skb_trim(struct sk_buff *skb, unsigned int len);
2703 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
2706 return ___pskb_trim(skb, len);
2707 __skb_trim(skb, len);
2711 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
2713 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
2717 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
2718 * @skb: buffer to alter
2721 * This is identical to pskb_trim except that the caller knows that
2722 * the skb is not cloned so we should never get an error due to out-
2725 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
2727 int err = pskb_trim(skb, len);
2731 static inline int __skb_grow(struct sk_buff *skb, unsigned int len)
2733 unsigned int diff = len - skb->len;
2735 if (skb_tailroom(skb) < diff) {
2736 int ret = pskb_expand_head(skb, 0, diff - skb_tailroom(skb),
2741 __skb_set_length(skb, len);
2746 * skb_orphan - orphan a buffer
2747 * @skb: buffer to orphan
2749 * If a buffer currently has an owner then we call the owner's
2750 * destructor function and make the @skb unowned. The buffer continues
2751 * to exist but is no longer charged to its former owner.
2753 static inline void skb_orphan(struct sk_buff *skb)
2755 if (skb->destructor) {
2756 skb->destructor(skb);
2757 skb->destructor = NULL;
2765 * skb_orphan_frags - orphan the frags contained in a buffer
2766 * @skb: buffer to orphan frags from
2767 * @gfp_mask: allocation mask for replacement pages
2769 * For each frag in the SKB which needs a destructor (i.e. has an
2770 * owner) create a copy of that frag and release the original
2771 * page by calling the destructor.
2773 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
2775 if (likely(!skb_zcopy(skb)))
2777 if (!skb_zcopy_is_nouarg(skb) &&
2778 skb_uarg(skb)->callback == sock_zerocopy_callback)
2780 return skb_copy_ubufs(skb, gfp_mask);
2783 /* Frags must be orphaned, even if refcounted, if skb might loop to rx path */
2784 static inline int skb_orphan_frags_rx(struct sk_buff *skb, gfp_t gfp_mask)
2786 if (likely(!skb_zcopy(skb)))
2788 return skb_copy_ubufs(skb, gfp_mask);
2792 * __skb_queue_purge - empty a list
2793 * @list: list to empty
2795 * Delete all buffers on an &sk_buff list. Each buffer is removed from
2796 * the list and one reference dropped. This function does not take the
2797 * list lock and the caller must hold the relevant locks to use it.
2799 static inline void __skb_queue_purge(struct sk_buff_head *list)
2801 struct sk_buff *skb;
2802 while ((skb = __skb_dequeue(list)) != NULL)
2805 void skb_queue_purge(struct sk_buff_head *list);
2807 unsigned int skb_rbtree_purge(struct rb_root *root);
2809 void *netdev_alloc_frag(unsigned int fragsz);
2811 struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length,
2815 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
2816 * @dev: network device to receive on
2817 * @length: length to allocate
2819 * Allocate a new &sk_buff and assign it a usage count of one. The
2820 * buffer has unspecified headroom built in. Users should allocate
2821 * the headroom they think they need without accounting for the
2822 * built in space. The built in space is used for optimisations.
2824 * %NULL is returned if there is no free memory. Although this function
2825 * allocates memory it can be called from an interrupt.
2827 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
2828 unsigned int length)
2830 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
2833 /* legacy helper around __netdev_alloc_skb() */
2834 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
2837 return __netdev_alloc_skb(NULL, length, gfp_mask);
2840 /* legacy helper around netdev_alloc_skb() */
2841 static inline struct sk_buff *dev_alloc_skb(unsigned int length)
2843 return netdev_alloc_skb(NULL, length);
2847 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
2848 unsigned int length, gfp_t gfp)
2850 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
2852 if (NET_IP_ALIGN && skb)
2853 skb_reserve(skb, NET_IP_ALIGN);
2857 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
2858 unsigned int length)
2860 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
2863 static inline void skb_free_frag(void *addr)
2865 page_frag_free(addr);
2868 void *napi_alloc_frag(unsigned int fragsz);
2869 struct sk_buff *__napi_alloc_skb(struct napi_struct *napi,
2870 unsigned int length, gfp_t gfp_mask);
2871 static inline struct sk_buff *napi_alloc_skb(struct napi_struct *napi,
2872 unsigned int length)
2874 return __napi_alloc_skb(napi, length, GFP_ATOMIC);
2876 void napi_consume_skb(struct sk_buff *skb, int budget);
2878 void __kfree_skb_flush(void);
2879 void __kfree_skb_defer(struct sk_buff *skb);
2882 * __dev_alloc_pages - allocate page for network Rx
2883 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2884 * @order: size of the allocation
2886 * Allocate a new page.
2888 * %NULL is returned if there is no free memory.
2890 static inline struct page *__dev_alloc_pages(gfp_t gfp_mask,
2893 /* This piece of code contains several assumptions.
2894 * 1. This is for device Rx, therefor a cold page is preferred.
2895 * 2. The expectation is the user wants a compound page.
2896 * 3. If requesting a order 0 page it will not be compound
2897 * due to the check to see if order has a value in prep_new_page
2898 * 4. __GFP_MEMALLOC is ignored if __GFP_NOMEMALLOC is set due to
2899 * code in gfp_to_alloc_flags that should be enforcing this.
2901 gfp_mask |= __GFP_COMP | __GFP_MEMALLOC;
2903 return alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
2906 static inline struct page *dev_alloc_pages(unsigned int order)
2908 return __dev_alloc_pages(GFP_ATOMIC | __GFP_NOWARN, order);
2912 * __dev_alloc_page - allocate a page for network Rx
2913 * @gfp_mask: allocation priority. Set __GFP_NOMEMALLOC if not for network Rx
2915 * Allocate a new page.
2917 * %NULL is returned if there is no free memory.
2919 static inline struct page *__dev_alloc_page(gfp_t gfp_mask)
2921 return __dev_alloc_pages(gfp_mask, 0);
2924 static inline struct page *dev_alloc_page(void)
2926 return dev_alloc_pages(0);
2930 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2931 * @page: The page that was allocated from skb_alloc_page
2932 * @skb: The skb that may need pfmemalloc set
2934 static inline void skb_propagate_pfmemalloc(struct page *page,
2935 struct sk_buff *skb)
2937 if (page_is_pfmemalloc(page))
2938 skb->pfmemalloc = true;
2942 * skb_frag_off() - Returns the offset of a skb fragment
2943 * @frag: the paged fragment
2945 static inline unsigned int skb_frag_off(const skb_frag_t *frag)
2947 return frag->bv_offset;
2951 * skb_frag_off_add() - Increments the offset of a skb fragment by @delta
2952 * @frag: skb fragment
2953 * @delta: value to add
2955 static inline void skb_frag_off_add(skb_frag_t *frag, int delta)
2957 frag->bv_offset += delta;
2961 * skb_frag_off_set() - Sets the offset of a skb fragment
2962 * @frag: skb fragment
2963 * @offset: offset of fragment
2965 static inline void skb_frag_off_set(skb_frag_t *frag, unsigned int offset)
2967 frag->bv_offset = offset;
2971 * skb_frag_off_copy() - Sets the offset of a skb fragment from another fragment
2972 * @fragto: skb fragment where offset is set
2973 * @fragfrom: skb fragment offset is copied from
2975 static inline void skb_frag_off_copy(skb_frag_t *fragto,
2976 const skb_frag_t *fragfrom)
2978 fragto->bv_offset = fragfrom->bv_offset;
2982 * skb_frag_page - retrieve the page referred to by a paged fragment
2983 * @frag: the paged fragment
2985 * Returns the &struct page associated with @frag.
2987 static inline struct page *skb_frag_page(const skb_frag_t *frag)
2989 return frag->bv_page;
2993 * __skb_frag_ref - take an addition reference on a paged fragment.
2994 * @frag: the paged fragment
2996 * Takes an additional reference on the paged fragment @frag.
2998 static inline void __skb_frag_ref(skb_frag_t *frag)
3000 get_page(skb_frag_page(frag));
3004 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
3006 * @f: the fragment offset.
3008 * Takes an additional reference on the @f'th paged fragment of @skb.
3010 static inline void skb_frag_ref(struct sk_buff *skb, int f)
3012 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
3016 * __skb_frag_unref - release a reference on a paged fragment.
3017 * @frag: the paged fragment
3019 * Releases a reference on the paged fragment @frag.
3021 static inline void __skb_frag_unref(skb_frag_t *frag)
3023 put_page(skb_frag_page(frag));
3027 * skb_frag_unref - release a reference on a paged fragment of an skb.
3029 * @f: the fragment offset
3031 * Releases a reference on the @f'th paged fragment of @skb.
3033 static inline void skb_frag_unref(struct sk_buff *skb, int f)
3035 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
3039 * skb_frag_address - gets the address of the data contained in a paged fragment
3040 * @frag: the paged fragment buffer
3042 * Returns the address of the data within @frag. The page must already
3045 static inline void *skb_frag_address(const skb_frag_t *frag)
3047 return page_address(skb_frag_page(frag)) + skb_frag_off(frag);
3051 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
3052 * @frag: the paged fragment buffer
3054 * Returns the address of the data within @frag. Checks that the page
3055 * is mapped and returns %NULL otherwise.
3057 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
3059 void *ptr = page_address(skb_frag_page(frag));
3063 return ptr + skb_frag_off(frag);
3067 * skb_frag_page_copy() - sets the page in a fragment from another fragment
3068 * @fragto: skb fragment where page is set
3069 * @fragfrom: skb fragment page is copied from
3071 static inline void skb_frag_page_copy(skb_frag_t *fragto,
3072 const skb_frag_t *fragfrom)
3074 fragto->bv_page = fragfrom->bv_page;
3078 * __skb_frag_set_page - sets the page contained in a paged fragment
3079 * @frag: the paged fragment
3080 * @page: the page to set
3082 * Sets the fragment @frag to contain @page.
3084 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
3086 frag->bv_page = page;
3090 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
3092 * @f: the fragment offset
3093 * @page: the page to set
3095 * Sets the @f'th fragment of @skb to contain @page.
3097 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
3100 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
3103 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);
3106 * skb_frag_dma_map - maps a paged fragment via the DMA API
3107 * @dev: the device to map the fragment to
3108 * @frag: the paged fragment to map
3109 * @offset: the offset within the fragment (starting at the
3110 * fragment's own offset)
3111 * @size: the number of bytes to map
3112 * @dir: the direction of the mapping (``PCI_DMA_*``)
3114 * Maps the page associated with @frag to @device.
3116 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
3117 const skb_frag_t *frag,
3118 size_t offset, size_t size,
3119 enum dma_data_direction dir)
3121 return dma_map_page(dev, skb_frag_page(frag),
3122 skb_frag_off(frag) + offset, size, dir);
3125 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
3128 return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
3132 static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb,
3135 return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true);
3140 * skb_clone_writable - is the header of a clone writable
3141 * @skb: buffer to check
3142 * @len: length up to which to write
3144 * Returns true if modifying the header part of the cloned buffer
3145 * does not requires the data to be copied.
3147 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
3149 return !skb_header_cloned(skb) &&
3150 skb_headroom(skb) + len <= skb->hdr_len;
3153 static inline int skb_try_make_writable(struct sk_buff *skb,
3154 unsigned int write_len)
3156 return skb_cloned(skb) && !skb_clone_writable(skb, write_len) &&
3157 pskb_expand_head(skb, 0, 0, GFP_ATOMIC);
3160 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
3165 if (headroom > skb_headroom(skb))
3166 delta = headroom - skb_headroom(skb);
3168 if (delta || cloned)
3169 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
3175 * skb_cow - copy header of skb when it is required
3176 * @skb: buffer to cow
3177 * @headroom: needed headroom
3179 * If the skb passed lacks sufficient headroom or its data part
3180 * is shared, data is reallocated. If reallocation fails, an error
3181 * is returned and original skb is not changed.
3183 * The result is skb with writable area skb->head...skb->tail
3184 * and at least @headroom of space at head.
3186 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
3188 return __skb_cow(skb, headroom, skb_cloned(skb));
3192 * skb_cow_head - skb_cow but only making the head writable
3193 * @skb: buffer to cow
3194 * @headroom: needed headroom
3196 * This function is identical to skb_cow except that we replace the
3197 * skb_cloned check by skb_header_cloned. It should be used when
3198 * you only need to push on some header and do not need to modify
3201 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
3203 return __skb_cow(skb, headroom, skb_header_cloned(skb));
3207 * skb_padto - pad an skbuff up to a minimal size
3208 * @skb: buffer to pad
3209 * @len: minimal length
3211 * Pads up a buffer to ensure the trailing bytes exist and are
3212 * blanked. If the buffer already contains sufficient data it
3213 * is untouched. Otherwise it is extended. Returns zero on
3214 * success. The skb is freed on error.
3216 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
3218 unsigned int size = skb->len;
3219 if (likely(size >= len))
3221 return skb_pad(skb, len - size);
3225 * __skb_put_padto - increase size and pad an skbuff up to a minimal size
3226 * @skb: buffer to pad
3227 * @len: minimal length
3228 * @free_on_error: free buffer on error
3230 * Pads up a buffer to ensure the trailing bytes exist and are
3231 * blanked. If the buffer already contains sufficient data it
3232 * is untouched. Otherwise it is extended. Returns zero on
3233 * success. The skb is freed on error if @free_on_error is true.
3235 static inline int __skb_put_padto(struct sk_buff *skb, unsigned int len,
3238 unsigned int size = skb->len;
3240 if (unlikely(size < len)) {
3242 if (__skb_pad(skb, len, free_on_error))
3244 __skb_put(skb, len);
3250 * skb_put_padto - increase size and pad an skbuff up to a minimal size
3251 * @skb: buffer to pad
3252 * @len: minimal length
3254 * Pads up a buffer to ensure the trailing bytes exist and are
3255 * blanked. If the buffer already contains sufficient data it
3256 * is untouched. Otherwise it is extended. Returns zero on
3257 * success. The skb is freed on error.
3259 static inline int skb_put_padto(struct sk_buff *skb, unsigned int len)
3261 return __skb_put_padto(skb, len, true);
3264 static inline int skb_add_data(struct sk_buff *skb,
3265 struct iov_iter *from, int copy)
3267 const int off = skb->len;
3269 if (skb->ip_summed == CHECKSUM_NONE) {
3271 if (csum_and_copy_from_iter_full(skb_put(skb, copy), copy,
3273 skb->csum = csum_block_add(skb->csum, csum, off);
3276 } else if (copy_from_iter_full(skb_put(skb, copy), copy, from))
3279 __skb_trim(skb, off);
3283 static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
3284 const struct page *page, int off)
3289 const skb_frag_t *frag = &skb_shinfo(skb)->frags[i - 1];
3291 return page == skb_frag_page(frag) &&
3292 off == skb_frag_off(frag) + skb_frag_size(frag);
3297 static inline int __skb_linearize(struct sk_buff *skb)
3299 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
3303 * skb_linearize - convert paged skb to linear one
3304 * @skb: buffer to linarize
3306 * If there is no free memory -ENOMEM is returned, otherwise zero
3307 * is returned and the old skb data released.
3309 static inline int skb_linearize(struct sk_buff *skb)
3311 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
3315 * skb_has_shared_frag - can any frag be overwritten
3316 * @skb: buffer to test
3318 * Return true if the skb has at least one frag that might be modified
3319 * by an external entity (as in vmsplice()/sendfile())
3321 static inline bool skb_has_shared_frag(const struct sk_buff *skb)
3323 return skb_is_nonlinear(skb) &&
3324 skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
3328 * skb_linearize_cow - make sure skb is linear and writable
3329 * @skb: buffer to process
3331 * If there is no free memory -ENOMEM is returned, otherwise zero
3332 * is returned and the old skb data released.
3334 static inline int skb_linearize_cow(struct sk_buff *skb)
3336 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
3337 __skb_linearize(skb) : 0;
3340 static __always_inline void
3341 __skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
3344 if (skb->ip_summed == CHECKSUM_COMPLETE)
3345 skb->csum = csum_block_sub(skb->csum,
3346 csum_partial(start, len, 0), off);
3347 else if (skb->ip_summed == CHECKSUM_PARTIAL &&
3348 skb_checksum_start_offset(skb) < 0)
3349 skb->ip_summed = CHECKSUM_NONE;
3353 * skb_postpull_rcsum - update checksum for received skb after pull
3354 * @skb: buffer to update
3355 * @start: start of data before pull
3356 * @len: length of data pulled
3358 * After doing a pull on a received packet, you need to call this to
3359 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
3360 * CHECKSUM_NONE so that it can be recomputed from scratch.
3362 static inline void skb_postpull_rcsum(struct sk_buff *skb,
3363 const void *start, unsigned int len)
3365 __skb_postpull_rcsum(skb, start, len, 0);
3368 static __always_inline void
3369 __skb_postpush_rcsum(struct sk_buff *skb, const void *start, unsigned int len,
3372 if (skb->ip_summed == CHECKSUM_COMPLETE)
3373 skb->csum = csum_block_add(skb->csum,
3374 csum_partial(start, len, 0), off);
3378 * skb_postpush_rcsum - update checksum for received skb after push
3379 * @skb: buffer to update
3380 * @start: start of data after push
3381 * @len: length of data pushed
3383 * After doing a push on a received packet, you need to call this to
3384 * update the CHECKSUM_COMPLETE checksum.
3386 static inline void skb_postpush_rcsum(struct sk_buff *skb,
3387 const void *start, unsigned int len)
3389 __skb_postpush_rcsum(skb, start, len, 0);
3392 void *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
3395 * skb_push_rcsum - push skb and update receive checksum
3396 * @skb: buffer to update
3397 * @len: length of data pulled
3399 * This function performs an skb_push on the packet and updates
3400 * the CHECKSUM_COMPLETE checksum. It should be used on
3401 * receive path processing instead of skb_push unless you know
3402 * that the checksum difference is zero (e.g., a valid IP header)
3403 * or you are setting ip_summed to CHECKSUM_NONE.
3405 static inline void *skb_push_rcsum(struct sk_buff *skb, unsigned int len)
3408 skb_postpush_rcsum(skb, skb->data, len);
3412 int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len);
3414 * pskb_trim_rcsum - trim received skb and update checksum
3415 * @skb: buffer to trim
3418 * This is exactly the same as pskb_trim except that it ensures the
3419 * checksum of received packets are still valid after the operation.
3420 * It can change skb pointers.
3423 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
3425 if (likely(len >= skb->len))
3427 return pskb_trim_rcsum_slow(skb, len);
3430 static inline int __skb_trim_rcsum(struct sk_buff *skb, unsigned int len)
3432 if (skb->ip_summed == CHECKSUM_COMPLETE)
3433 skb->ip_summed = CHECKSUM_NONE;
3434 __skb_trim(skb, len);
3438 static inline int __skb_grow_rcsum(struct sk_buff *skb, unsigned int len)
3440 if (skb->ip_summed == CHECKSUM_COMPLETE)
3441 skb->ip_summed = CHECKSUM_NONE;
3442 return __skb_grow(skb, len);
3445 #define rb_to_skb(rb) rb_entry_safe(rb, struct sk_buff, rbnode)
3446 #define skb_rb_first(root) rb_to_skb(rb_first(root))
3447 #define skb_rb_last(root) rb_to_skb(rb_last(root))
3448 #define skb_rb_next(skb) rb_to_skb(rb_next(&(skb)->rbnode))
3449 #define skb_rb_prev(skb) rb_to_skb(rb_prev(&(skb)->rbnode))
3451 #define skb_queue_walk(queue, skb) \
3452 for (skb = (queue)->next; \
3453 skb != (struct sk_buff *)(queue); \
3456 #define skb_queue_walk_safe(queue, skb, tmp) \
3457 for (skb = (queue)->next, tmp = skb->next; \
3458 skb != (struct sk_buff *)(queue); \
3459 skb = tmp, tmp = skb->next)
3461 #define skb_queue_walk_from(queue, skb) \
3462 for (; skb != (struct sk_buff *)(queue); \
3465 #define skb_rbtree_walk(skb, root) \
3466 for (skb = skb_rb_first(root); skb != NULL; \
3467 skb = skb_rb_next(skb))
3469 #define skb_rbtree_walk_from(skb) \
3470 for (; skb != NULL; \
3471 skb = skb_rb_next(skb))
3473 #define skb_rbtree_walk_from_safe(skb, tmp) \
3474 for (; tmp = skb ? skb_rb_next(skb) : NULL, (skb != NULL); \
3477 #define skb_queue_walk_from_safe(queue, skb, tmp) \
3478 for (tmp = skb->next; \
3479 skb != (struct sk_buff *)(queue); \
3480 skb = tmp, tmp = skb->next)
3482 #define skb_queue_reverse_walk(queue, skb) \
3483 for (skb = (queue)->prev; \
3484 skb != (struct sk_buff *)(queue); \
3487 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
3488 for (skb = (queue)->prev, tmp = skb->prev; \
3489 skb != (struct sk_buff *)(queue); \
3490 skb = tmp, tmp = skb->prev)
3492 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
3493 for (tmp = skb->prev; \
3494 skb != (struct sk_buff *)(queue); \
3495 skb = tmp, tmp = skb->prev)
3497 static inline bool skb_has_frag_list(const struct sk_buff *skb)
3499 return skb_shinfo(skb)->frag_list != NULL;
3502 static inline void skb_frag_list_init(struct sk_buff *skb)
3504 skb_shinfo(skb)->frag_list = NULL;
3507 #define skb_walk_frags(skb, iter) \
3508 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
3511 int __skb_wait_for_more_packets(struct sock *sk, struct sk_buff_head *queue,
3512 int *err, long *timeo_p,
3513 const struct sk_buff *skb);
3514 struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,
3515 struct sk_buff_head *queue,
3517 void (*destructor)(struct sock *sk,
3518 struct sk_buff *skb),
3520 struct sk_buff **last);
3521 struct sk_buff *__skb_try_recv_datagram(struct sock *sk,
3522 struct sk_buff_head *queue,
3524 void (*destructor)(struct sock *sk,
3525 struct sk_buff *skb),
3527 struct sk_buff **last);
3528 struct sk_buff *__skb_recv_datagram(struct sock *sk,
3529 struct sk_buff_head *sk_queue,
3531 void (*destructor)(struct sock *sk,
3532 struct sk_buff *skb),
3533 int *off, int *err);
3534 struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock,
3536 __poll_t datagram_poll(struct file *file, struct socket *sock,
3537 struct poll_table_struct *wait);
3538 int skb_copy_datagram_iter(const struct sk_buff *from, int offset,
3539 struct iov_iter *to, int size);
3540 static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset,
3541 struct msghdr *msg, int size)
3543 return skb_copy_datagram_iter(from, offset, &msg->msg_iter, size);
3545 int skb_copy_and_csum_datagram_msg(struct sk_buff *skb, int hlen,
3546 struct msghdr *msg);
3547 int skb_copy_and_hash_datagram_iter(const struct sk_buff *skb, int offset,
3548 struct iov_iter *to, int len,
3549 struct ahash_request *hash);
3550 int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset,
3551 struct iov_iter *from, int len);
3552 int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm);
3553 void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
3554 void __skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb, int len);
3555 static inline void skb_free_datagram_locked(struct sock *sk,
3556 struct sk_buff *skb)
3558 __skb_free_datagram_locked(sk, skb, 0);
3560 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);
3561 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
3562 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
3563 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
3564 int len, __wsum csum);
3565 int skb_splice_bits(struct sk_buff *skb, struct sock *sk, unsigned int offset,
3566 struct pipe_inode_info *pipe, unsigned int len,
3567 unsigned int flags);
3568 int skb_send_sock_locked(struct sock *sk, struct sk_buff *skb, int offset,
3570 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
3571 unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
3572 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
3574 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
3575 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
3576 void skb_scrub_packet(struct sk_buff *skb, bool xnet);
3577 bool skb_gso_validate_network_len(const struct sk_buff *skb, unsigned int mtu);
3578 bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len);
3579 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
3580 struct sk_buff *skb_segment_list(struct sk_buff *skb, netdev_features_t features,
3581 unsigned int offset);
3582 struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
3583 int skb_ensure_writable(struct sk_buff *skb, int write_len);
3584 int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci);
3585 int skb_vlan_pop(struct sk_buff *skb);
3586 int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
3587 int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto,
3588 int mac_len, bool ethernet);
3589 int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len,
3591 int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse);
3592 int skb_mpls_dec_ttl(struct sk_buff *skb);
3593 struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy,
3596 static inline int memcpy_from_msg(void *data, struct msghdr *msg, int len)
3598 return copy_from_iter_full(data, len, &msg->msg_iter) ? 0 : -EFAULT;
3601 static inline int memcpy_to_msg(struct msghdr *msg, void *data, int len)
3603 return copy_to_iter(data, len, &msg->msg_iter) == len ? 0 : -EFAULT;
3606 struct skb_checksum_ops {
3607 __wsum (*update)(const void *mem, int len, __wsum wsum);
3608 __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len);
3611 extern const struct skb_checksum_ops *crc32c_csum_stub __read_mostly;
3613 __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
3614 __wsum csum, const struct skb_checksum_ops *ops);
3615 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
3618 static inline void * __must_check
3619 __skb_header_pointer(const struct sk_buff *skb, int offset,
3620 int len, void *data, int hlen, void *buffer)
3622 if (hlen - offset >= len)
3623 return data + offset;
3626 skb_copy_bits(skb, offset, buffer, len) < 0)
3632 static inline void * __must_check
3633 skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *buffer)
3635 return __skb_header_pointer(skb, offset, len, skb->data,
3636 skb_headlen(skb), buffer);
3640 * skb_needs_linearize - check if we need to linearize a given skb
3641 * depending on the given device features.
3642 * @skb: socket buffer to check
3643 * @features: net device features
3645 * Returns true if either:
3646 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
3647 * 2. skb is fragmented and the device does not support SG.
3649 static inline bool skb_needs_linearize(struct sk_buff *skb,
3650 netdev_features_t features)
3652 return skb_is_nonlinear(skb) &&
3653 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
3654 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
3657 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
3659 const unsigned int len)
3661 memcpy(to, skb->data, len);
3664 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
3665 const int offset, void *to,
3666 const unsigned int len)
3668 memcpy(to, skb->data + offset, len);
3671 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
3673 const unsigned int len)
3675 memcpy(skb->data, from, len);
3678 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
3681 const unsigned int len)
3683 memcpy(skb->data + offset, from, len);
3686 void skb_init(void);
3688 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
3694 * skb_get_timestamp - get timestamp from a skb
3695 * @skb: skb to get stamp from
3696 * @stamp: pointer to struct __kernel_old_timeval to store stamp in
3698 * Timestamps are stored in the skb as offsets to a base timestamp.
3699 * This function converts the offset back to a struct timeval and stores
3702 static inline void skb_get_timestamp(const struct sk_buff *skb,
3703 struct __kernel_old_timeval *stamp)
3705 *stamp = ns_to_kernel_old_timeval(skb->tstamp);
3708 static inline void skb_get_new_timestamp(const struct sk_buff *skb,
3709 struct __kernel_sock_timeval *stamp)
3711 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
3713 stamp->tv_sec = ts.tv_sec;
3714 stamp->tv_usec = ts.tv_nsec / 1000;
3717 static inline void skb_get_timestampns(const struct sk_buff *skb,
3718 struct __kernel_old_timespec *stamp)
3720 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
3722 stamp->tv_sec = ts.tv_sec;
3723 stamp->tv_nsec = ts.tv_nsec;
3726 static inline void skb_get_new_timestampns(const struct sk_buff *skb,
3727 struct __kernel_timespec *stamp)
3729 struct timespec64 ts = ktime_to_timespec64(skb->tstamp);
3731 stamp->tv_sec = ts.tv_sec;
3732 stamp->tv_nsec = ts.tv_nsec;
3735 static inline void __net_timestamp(struct sk_buff *skb)
3737 skb->tstamp = ktime_get_real();
3740 static inline ktime_t net_timedelta(ktime_t t)
3742 return ktime_sub(ktime_get_real(), t);
3745 static inline ktime_t net_invalid_timestamp(void)
3750 static inline u8 skb_metadata_len(const struct sk_buff *skb)
3752 return skb_shinfo(skb)->meta_len;
3755 static inline void *skb_metadata_end(const struct sk_buff *skb)
3757 return skb_mac_header(skb);
3760 static inline bool __skb_metadata_differs(const struct sk_buff *skb_a,
3761 const struct sk_buff *skb_b,
3764 const void *a = skb_metadata_end(skb_a);
3765 const void *b = skb_metadata_end(skb_b);
3766 /* Using more efficient varaiant than plain call to memcmp(). */
3767 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
3771 #define __it(x, op) (x -= sizeof(u##op))
3772 #define __it_diff(a, b, op) (*(u##op *)__it(a, op)) ^ (*(u##op *)__it(b, op))
3773 case 32: diffs |= __it_diff(a, b, 64);
3775 case 24: diffs |= __it_diff(a, b, 64);
3777 case 16: diffs |= __it_diff(a, b, 64);
3779 case 8: diffs |= __it_diff(a, b, 64);
3781 case 28: diffs |= __it_diff(a, b, 64);
3783 case 20: diffs |= __it_diff(a, b, 64);
3785 case 12: diffs |= __it_diff(a, b, 64);
3787 case 4: diffs |= __it_diff(a, b, 32);
3792 return memcmp(a - meta_len, b - meta_len, meta_len);
3796 static inline bool skb_metadata_differs(const struct sk_buff *skb_a,
3797 const struct sk_buff *skb_b)
3799 u8 len_a = skb_metadata_len(skb_a);
3800 u8 len_b = skb_metadata_len(skb_b);
3802 if (!(len_a | len_b))
3805 return len_a != len_b ?
3806 true : __skb_metadata_differs(skb_a, skb_b, len_a);
3809 static inline void skb_metadata_set(struct sk_buff *skb, u8 meta_len)
3811 skb_shinfo(skb)->meta_len = meta_len;
3814 static inline void skb_metadata_clear(struct sk_buff *skb)
3816 skb_metadata_set(skb, 0);
3819 struct sk_buff *skb_clone_sk(struct sk_buff *skb);
3821 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
3823 void skb_clone_tx_timestamp(struct sk_buff *skb);
3824 bool skb_defer_rx_timestamp(struct sk_buff *skb);
3826 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
3828 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
3832 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
3837 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
3840 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
3842 * PHY drivers may accept clones of transmitted packets for
3843 * timestamping via their phy_driver.txtstamp method. These drivers
3844 * must call this function to return the skb back to the stack with a
3847 * @skb: clone of the the original outgoing packet
3848 * @hwtstamps: hardware time stamps
3851 void skb_complete_tx_timestamp(struct sk_buff *skb,
3852 struct skb_shared_hwtstamps *hwtstamps);
3854 void __skb_tstamp_tx(struct sk_buff *orig_skb,
3855 struct skb_shared_hwtstamps *hwtstamps,
3856 struct sock *sk, int tstype);
3859 * skb_tstamp_tx - queue clone of skb with send time stamps
3860 * @orig_skb: the original outgoing packet
3861 * @hwtstamps: hardware time stamps, may be NULL if not available
3863 * If the skb has a socket associated, then this function clones the
3864 * skb (thus sharing the actual data and optional structures), stores
3865 * the optional hardware time stamping information (if non NULL) or
3866 * generates a software time stamp (otherwise), then queues the clone
3867 * to the error queue of the socket. Errors are silently ignored.
3869 void skb_tstamp_tx(struct sk_buff *orig_skb,
3870 struct skb_shared_hwtstamps *hwtstamps);
3873 * skb_tx_timestamp() - Driver hook for transmit timestamping
3875 * Ethernet MAC Drivers should call this function in their hard_xmit()
3876 * function immediately before giving the sk_buff to the MAC hardware.
3878 * Specifically, one should make absolutely sure that this function is
3879 * called before TX completion of this packet can trigger. Otherwise
3880 * the packet could potentially already be freed.
3882 * @skb: A socket buffer.
3884 static inline void skb_tx_timestamp(struct sk_buff *skb)
3886 skb_clone_tx_timestamp(skb);
3887 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP)
3888 skb_tstamp_tx(skb, NULL);
3892 * skb_complete_wifi_ack - deliver skb with wifi status
3894 * @skb: the original outgoing packet
3895 * @acked: ack status
3898 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
3900 __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
3901 __sum16 __skb_checksum_complete(struct sk_buff *skb);
3903 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
3905 return ((skb->ip_summed == CHECKSUM_UNNECESSARY) ||
3907 (skb->ip_summed == CHECKSUM_PARTIAL &&
3908 skb_checksum_start_offset(skb) >= 0));
3912 * skb_checksum_complete - Calculate checksum of an entire packet
3913 * @skb: packet to process
3915 * This function calculates the checksum over the entire packet plus
3916 * the value of skb->csum. The latter can be used to supply the
3917 * checksum of a pseudo header as used by TCP/UDP. It returns the
3920 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
3921 * this function can be used to verify that checksum on received
3922 * packets. In that case the function should return zero if the
3923 * checksum is correct. In particular, this function will return zero
3924 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
3925 * hardware has already verified the correctness of the checksum.
3927 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
3929 return skb_csum_unnecessary(skb) ?
3930 0 : __skb_checksum_complete(skb);
3933 static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb)
3935 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
3936 if (skb->csum_level == 0)
3937 skb->ip_summed = CHECKSUM_NONE;
3943 static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb)
3945 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
3946 if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
3948 } else if (skb->ip_summed == CHECKSUM_NONE) {
3949 skb->ip_summed = CHECKSUM_UNNECESSARY;
3950 skb->csum_level = 0;
3954 /* Check if we need to perform checksum complete validation.
3956 * Returns true if checksum complete is needed, false otherwise
3957 * (either checksum is unnecessary or zero checksum is allowed).
3959 static inline bool __skb_checksum_validate_needed(struct sk_buff *skb,
3963 if (skb_csum_unnecessary(skb) || (zero_okay && !check)) {
3964 skb->csum_valid = 1;
3965 __skb_decr_checksum_unnecessary(skb);
3972 /* For small packets <= CHECKSUM_BREAK perform checksum complete directly
3975 #define CHECKSUM_BREAK 76
3977 /* Unset checksum-complete
3979 * Unset checksum complete can be done when packet is being modified
3980 * (uncompressed for instance) and checksum-complete value is
3983 static inline void skb_checksum_complete_unset(struct sk_buff *skb)
3985 if (skb->ip_summed == CHECKSUM_COMPLETE)
3986 skb->ip_summed = CHECKSUM_NONE;
3989 /* Validate (init) checksum based on checksum complete.
3992 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
3993 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
3994 * checksum is stored in skb->csum for use in __skb_checksum_complete
3995 * non-zero: value of invalid checksum
3998 static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
4002 if (skb->ip_summed == CHECKSUM_COMPLETE) {
4003 if (!csum_fold(csum_add(psum, skb->csum))) {
4004 skb->csum_valid = 1;
4011 if (complete || skb->len <= CHECKSUM_BREAK) {
4014 csum = __skb_checksum_complete(skb);
4015 skb->csum_valid = !csum;
4022 static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)
4027 /* Perform checksum validate (init). Note that this is a macro since we only
4028 * want to calculate the pseudo header which is an input function if necessary.
4029 * First we try to validate without any computation (checksum unnecessary) and
4030 * then calculate based on checksum complete calling the function to compute
4034 * 0: checksum is validated or try to in skb_checksum_complete
4035 * non-zero: value of invalid checksum
4037 #define __skb_checksum_validate(skb, proto, complete, \
4038 zero_okay, check, compute_pseudo) \
4040 __sum16 __ret = 0; \
4041 skb->csum_valid = 0; \
4042 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
4043 __ret = __skb_checksum_validate_complete(skb, \
4044 complete, compute_pseudo(skb, proto)); \
4048 #define skb_checksum_init(skb, proto, compute_pseudo) \
4049 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
4051 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
4052 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
4054 #define skb_checksum_validate(skb, proto, compute_pseudo) \
4055 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
4057 #define skb_checksum_validate_zero_check(skb, proto, check, \
4059 __skb_checksum_validate(skb, proto, true, true, check, compute_pseudo)
4061 #define skb_checksum_simple_validate(skb) \
4062 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
4064 static inline bool __skb_checksum_convert_check(struct sk_buff *skb)
4066 return (skb->ip_summed == CHECKSUM_NONE && skb->csum_valid);
4069 static inline void __skb_checksum_convert(struct sk_buff *skb, __wsum pseudo)
4071 skb->csum = ~pseudo;
4072 skb->ip_summed = CHECKSUM_COMPLETE;
4075 #define skb_checksum_try_convert(skb, proto, compute_pseudo) \
4077 if (__skb_checksum_convert_check(skb)) \
4078 __skb_checksum_convert(skb, compute_pseudo(skb, proto)); \
4081 static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr,
4082 u16 start, u16 offset)
4084 skb->ip_summed = CHECKSUM_PARTIAL;
4085 skb->csum_start = ((unsigned char *)ptr + start) - skb->head;
4086 skb->csum_offset = offset - start;
4089 /* Update skbuf and packet to reflect the remote checksum offload operation.
4090 * When called, ptr indicates the starting point for skb->csum when
4091 * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
4092 * here, skb_postpull_rcsum is done so skb->csum start is ptr.
4094 static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr,
4095 int start, int offset, bool nopartial)
4100 skb_remcsum_adjust_partial(skb, ptr, start, offset);
4104 if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) {
4105 __skb_checksum_complete(skb);
4106 skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data);
4109 delta = remcsum_adjust(ptr, skb->csum, start, offset);
4111 /* Adjust skb->csum since we changed the packet */
4112 skb->csum = csum_add(skb->csum, delta);
4115 static inline struct nf_conntrack *skb_nfct(const struct sk_buff *skb)
4117 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4118 return (void *)(skb->_nfct & NFCT_PTRMASK);
4124 static inline unsigned long skb_get_nfct(const struct sk_buff *skb)
4126 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4133 static inline void skb_set_nfct(struct sk_buff *skb, unsigned long nfct)
4135 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
4140 #ifdef CONFIG_SKB_EXTENSIONS
4142 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
4148 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
4151 #if IS_ENABLED(CONFIG_MPTCP)
4154 SKB_EXT_NUM, /* must be last */
4158 * struct skb_ext - sk_buff extensions
4159 * @refcnt: 1 on allocation, deallocated on 0
4160 * @offset: offset to add to @data to obtain extension address
4161 * @chunks: size currently allocated, stored in SKB_EXT_ALIGN_SHIFT units
4162 * @data: start of extension data, variable sized
4164 * Note: offsets/lengths are stored in chunks of 8 bytes, this allows
4165 * to use 'u8' types while allowing up to 2kb worth of extension data.
4169 u8 offset[SKB_EXT_NUM]; /* in chunks of 8 bytes */
4170 u8 chunks; /* same */
4171 char data[0] __aligned(8);
4174 struct skb_ext *__skb_ext_alloc(void);
4175 void *__skb_ext_set(struct sk_buff *skb, enum skb_ext_id id,
4176 struct skb_ext *ext);
4177 void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id);
4178 void __skb_ext_del(struct sk_buff *skb, enum skb_ext_id id);
4179 void __skb_ext_put(struct skb_ext *ext);
4181 static inline void skb_ext_put(struct sk_buff *skb)
4183 if (skb->active_extensions)
4184 __skb_ext_put(skb->extensions);
4187 static inline void __skb_ext_copy(struct sk_buff *dst,
4188 const struct sk_buff *src)
4190 dst->active_extensions = src->active_extensions;
4192 if (src->active_extensions) {
4193 struct skb_ext *ext = src->extensions;
4195 refcount_inc(&ext->refcnt);
4196 dst->extensions = ext;
4200 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *src)
4203 __skb_ext_copy(dst, src);
4206 static inline bool __skb_ext_exist(const struct skb_ext *ext, enum skb_ext_id i)
4208 return !!ext->offset[i];
4211 static inline bool skb_ext_exist(const struct sk_buff *skb, enum skb_ext_id id)
4213 return skb->active_extensions & (1 << id);
4216 static inline void skb_ext_del(struct sk_buff *skb, enum skb_ext_id id)
4218 if (skb_ext_exist(skb, id))
4219 __skb_ext_del(skb, id);
4222 static inline void *skb_ext_find(const struct sk_buff *skb, enum skb_ext_id id)
4224 if (skb_ext_exist(skb, id)) {
4225 struct skb_ext *ext = skb->extensions;
4227 return (void *)ext + (ext->offset[id] << 3);
4233 static inline void skb_ext_reset(struct sk_buff *skb)
4235 if (unlikely(skb->active_extensions)) {
4236 __skb_ext_put(skb->extensions);
4237 skb->active_extensions = 0;
4241 static inline bool skb_has_extensions(struct sk_buff *skb)
4243 return unlikely(skb->active_extensions);
4246 static inline void skb_ext_put(struct sk_buff *skb) {}
4247 static inline void skb_ext_reset(struct sk_buff *skb) {}
4248 static inline void skb_ext_del(struct sk_buff *skb, int unused) {}
4249 static inline void __skb_ext_copy(struct sk_buff *d, const struct sk_buff *s) {}
4250 static inline void skb_ext_copy(struct sk_buff *dst, const struct sk_buff *s) {}
4251 static inline bool skb_has_extensions(struct sk_buff *skb) { return false; }
4252 #endif /* CONFIG_SKB_EXTENSIONS */
4254 static inline void nf_reset_ct(struct sk_buff *skb)
4256 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4257 nf_conntrack_put(skb_nfct(skb));
4262 static inline void nf_reset_trace(struct sk_buff *skb)
4264 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
4269 static inline void ipvs_reset(struct sk_buff *skb)
4271 #if IS_ENABLED(CONFIG_IP_VS)
4272 skb->ipvs_property = 0;
4276 /* Note: This doesn't put any conntrack info in dst. */
4277 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src,
4280 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4281 dst->_nfct = src->_nfct;
4282 nf_conntrack_get(skb_nfct(src));
4284 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
4286 dst->nf_trace = src->nf_trace;
4290 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
4292 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
4293 nf_conntrack_put(skb_nfct(dst));
4295 __nf_copy(dst, src, true);
4298 #ifdef CONFIG_NETWORK_SECMARK
4299 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
4301 to->secmark = from->secmark;
4304 static inline void skb_init_secmark(struct sk_buff *skb)
4309 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
4312 static inline void skb_init_secmark(struct sk_buff *skb)
4316 static inline int secpath_exists(const struct sk_buff *skb)
4319 return skb_ext_exist(skb, SKB_EXT_SEC_PATH);
4325 static inline bool skb_irq_freeable(const struct sk_buff *skb)
4327 return !skb->destructor &&
4328 !secpath_exists(skb) &&
4330 !skb->_skb_refdst &&
4331 !skb_has_frag_list(skb);
4334 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
4336 skb->queue_mapping = queue_mapping;
4339 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
4341 return skb->queue_mapping;
4344 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
4346 to->queue_mapping = from->queue_mapping;
4349 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
4351 skb->queue_mapping = rx_queue + 1;
4354 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
4356 return skb->queue_mapping - 1;
4359 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
4361 return skb->queue_mapping != 0;
4364 static inline void skb_set_dst_pending_confirm(struct sk_buff *skb, u32 val)
4366 skb->dst_pending_confirm = val;
4369 static inline bool skb_get_dst_pending_confirm(const struct sk_buff *skb)
4371 return skb->dst_pending_confirm != 0;
4374 static inline struct sec_path *skb_sec_path(const struct sk_buff *skb)
4377 return skb_ext_find(skb, SKB_EXT_SEC_PATH);
4383 /* Keeps track of mac header offset relative to skb->head.
4384 * It is useful for TSO of Tunneling protocol. e.g. GRE.
4385 * For non-tunnel skb it points to skb_mac_header() and for
4386 * tunnel skb it points to outer mac header.
4387 * Keeps track of level of encapsulation of network headers.
4398 #define SKB_SGO_CB_OFFSET 32
4399 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_SGO_CB_OFFSET))
4401 static inline int skb_tnl_header_len(const struct sk_buff *inner_skb)
4403 return (skb_mac_header(inner_skb) - inner_skb->head) -
4404 SKB_GSO_CB(inner_skb)->mac_offset;
4407 static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra)
4409 int new_headroom, headroom;
4412 headroom = skb_headroom(skb);
4413 ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC);
4417 new_headroom = skb_headroom(skb);
4418 SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom);
4422 static inline void gso_reset_checksum(struct sk_buff *skb, __wsum res)
4424 /* Do not update partial checksums if remote checksum is enabled. */
4425 if (skb->remcsum_offload)
4428 SKB_GSO_CB(skb)->csum = res;
4429 SKB_GSO_CB(skb)->csum_start = skb_checksum_start(skb) - skb->head;
4432 /* Compute the checksum for a gso segment. First compute the checksum value
4433 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
4434 * then add in skb->csum (checksum from csum_start to end of packet).
4435 * skb->csum and csum_start are then updated to reflect the checksum of the
4436 * resultant packet starting from the transport header-- the resultant checksum
4437 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
4440 static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res)
4442 unsigned char *csum_start = skb_transport_header(skb);
4443 int plen = (skb->head + SKB_GSO_CB(skb)->csum_start) - csum_start;
4444 __wsum partial = SKB_GSO_CB(skb)->csum;
4446 SKB_GSO_CB(skb)->csum = res;
4447 SKB_GSO_CB(skb)->csum_start = csum_start - skb->head;
4449 return csum_fold(csum_partial(csum_start, plen, partial));
4452 static inline bool skb_is_gso(const struct sk_buff *skb)
4454 return skb_shinfo(skb)->gso_size;
4457 /* Note: Should be called only if skb_is_gso(skb) is true */
4458 static inline bool skb_is_gso_v6(const struct sk_buff *skb)
4460 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
4463 /* Note: Should be called only if skb_is_gso(skb) is true */
4464 static inline bool skb_is_gso_sctp(const struct sk_buff *skb)
4466 return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP;
4469 /* Note: Should be called only if skb_is_gso(skb) is true */
4470 static inline bool skb_is_gso_tcp(const struct sk_buff *skb)
4472 return skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6);
4475 static inline void skb_gso_reset(struct sk_buff *skb)
4477 skb_shinfo(skb)->gso_size = 0;
4478 skb_shinfo(skb)->gso_segs = 0;
4479 skb_shinfo(skb)->gso_type = 0;
4482 static inline void skb_increase_gso_size(struct skb_shared_info *shinfo,
4485 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
4487 shinfo->gso_size += increment;
4490 static inline void skb_decrease_gso_size(struct skb_shared_info *shinfo,
4493 if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
4495 shinfo->gso_size -= decrement;
4498 void __skb_warn_lro_forwarding(const struct sk_buff *skb);
4500 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
4502 /* LRO sets gso_size but not gso_type, whereas if GSO is really
4503 * wanted then gso_type will be set. */
4504 const struct skb_shared_info *shinfo = skb_shinfo(skb);
4506 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
4507 unlikely(shinfo->gso_type == 0)) {
4508 __skb_warn_lro_forwarding(skb);
4514 static inline void skb_forward_csum(struct sk_buff *skb)
4516 /* Unfortunately we don't support this one. Any brave souls? */
4517 if (skb->ip_summed == CHECKSUM_COMPLETE)
4518 skb->ip_summed = CHECKSUM_NONE;
4522 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
4523 * @skb: skb to check
4525 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
4526 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
4527 * use this helper, to document places where we make this assertion.
4529 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
4532 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
4536 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
4538 int skb_checksum_setup(struct sk_buff *skb, bool recalculate);
4539 struct sk_buff *skb_checksum_trimmed(struct sk_buff *skb,
4540 unsigned int transport_len,
4541 __sum16(*skb_chkf)(struct sk_buff *skb));
4544 * skb_head_is_locked - Determine if the skb->head is locked down
4545 * @skb: skb to check
4547 * The head on skbs build around a head frag can be removed if they are
4548 * not cloned. This function returns true if the skb head is locked down
4549 * due to either being allocated via kmalloc, or by being a clone with
4550 * multiple references to the head.
4552 static inline bool skb_head_is_locked(const struct sk_buff *skb)
4554 return !skb->head_frag || skb_cloned(skb);
4557 /* Local Checksum Offload.
4558 * Compute outer checksum based on the assumption that the
4559 * inner checksum will be offloaded later.
4560 * See Documentation/networking/checksum-offloads.rst for
4561 * explanation of how this works.
4562 * Fill in outer checksum adjustment (e.g. with sum of outer
4563 * pseudo-header) before calling.
4564 * Also ensure that inner checksum is in linear data area.
4566 static inline __wsum lco_csum(struct sk_buff *skb)
4568 unsigned char *csum_start = skb_checksum_start(skb);
4569 unsigned char *l4_hdr = skb_transport_header(skb);
4572 /* Start with complement of inner checksum adjustment */
4573 partial = ~csum_unfold(*(__force __sum16 *)(csum_start +
4576 /* Add in checksum of our headers (incl. outer checksum
4577 * adjustment filled in by caller) and return result.
4579 return csum_partial(l4_hdr, csum_start - l4_hdr, partial);
4582 #endif /* __KERNEL__ */
4583 #endif /* _LINUX_SKBUFF_H */