2 * Definitions for the 'struct sk_buff' memory handlers.
5 * Alan Cox, <gw4pts@gw4pts.ampr.org>
6 * Florian La Roche, <rzsfl@rz.uni-sb.de>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #ifndef _LINUX_SKBUFF_H
15 #define _LINUX_SKBUFF_H
17 #include <linux/kernel.h>
18 #include <linux/kmemcheck.h>
19 #include <linux/compiler.h>
20 #include <linux/time.h>
21 #include <linux/bug.h>
22 #include <linux/cache.h>
24 #include <linux/atomic.h>
25 #include <asm/types.h>
26 #include <linux/spinlock.h>
27 #include <linux/net.h>
28 #include <linux/textsearch.h>
29 #include <net/checksum.h>
30 #include <linux/rcupdate.h>
31 #include <linux/dmaengine.h>
32 #include <linux/hrtimer.h>
33 #include <linux/dma-mapping.h>
34 #include <linux/netdev_features.h>
35 #include <linux/sched.h>
36 #include <net/flow_keys.h>
38 /* A. Checksumming of received packets by device.
42 * Device failed to checksum this packet e.g. due to lack of capabilities.
43 * The packet contains full (though not verified) checksum in packet but
44 * not in skb->csum. Thus, skb->csum is undefined in this case.
46 * CHECKSUM_UNNECESSARY:
48 * The hardware you're dealing with doesn't calculate the full checksum
49 * (as in CHECKSUM_COMPLETE), but it does parse headers and verify checksums
50 * for specific protocols. For such packets it will set CHECKSUM_UNNECESSARY
51 * if their checksums are okay. skb->csum is still undefined in this case
52 * though. It is a bad option, but, unfortunately, nowadays most vendors do
53 * this. Apparently with the secret goal to sell you new devices, when you
54 * will add new protocol to your host, f.e. IPv6 8)
56 * CHECKSUM_UNNECESSARY is applicable to following protocols:
58 * UDP: IPv4 and IPv6. A device may apply CHECKSUM_UNNECESSARY to a
59 * zero UDP checksum for either IPv4 or IPv6, the networking stack
60 * may perform further validation in this case.
61 * GRE: only if the checksum is present in the header.
62 * SCTP: indicates the CRC in SCTP header has been validated.
64 * skb->csum_level indicates the number of consecutive checksums found in
65 * the packet minus one that have been verified as CHECKSUM_UNNECESSARY.
66 * For instance if a device receives an IPv6->UDP->GRE->IPv4->TCP packet
67 * and a device is able to verify the checksums for UDP (possibly zero),
68 * GRE (checksum flag is set), and TCP-- skb->csum_level would be set to
69 * two. If the device were only able to verify the UDP checksum and not
70 * GRE, either because it doesn't support GRE checksum of because GRE
71 * checksum is bad, skb->csum_level would be set to zero (TCP checksum is
72 * not considered in this case).
76 * This is the most generic way. The device supplied checksum of the _whole_
77 * packet as seen by netif_rx() and fills out in skb->csum. Meaning, the
78 * hardware doesn't need to parse L3/L4 headers to implement this.
80 * Note: Even if device supports only some protocols, but is able to produce
81 * skb->csum, it MUST use CHECKSUM_COMPLETE, not CHECKSUM_UNNECESSARY.
85 * This is identical to the case for output below. This may occur on a packet
86 * received directly from another Linux OS, e.g., a virtualized Linux kernel
87 * on the same host. The packet can be treated in the same way as
88 * CHECKSUM_UNNECESSARY, except that on output (i.e., forwarding) the
89 * checksum must be filled in by the OS or the hardware.
91 * B. Checksumming on output.
95 * The skb was already checksummed by the protocol, or a checksum is not
100 * The device is required to checksum the packet as seen by hard_start_xmit()
101 * from skb->csum_start up to the end, and to record/write the checksum at
102 * offset skb->csum_start + skb->csum_offset.
104 * The device must show its capabilities in dev->features, set up at device
105 * setup time, e.g. netdev_features.h:
107 * NETIF_F_HW_CSUM - It's a clever device, it's able to checksum everything.
108 * NETIF_F_IP_CSUM - Device is dumb, it's able to checksum only TCP/UDP over
109 * IPv4. Sigh. Vendors like this way for an unknown reason.
110 * Though, see comment above about CHECKSUM_UNNECESSARY. 8)
111 * NETIF_F_IPV6_CSUM - About as dumb as the last one but does IPv6 instead.
112 * NETIF_F_... - Well, you get the picture.
114 * CHECKSUM_UNNECESSARY:
116 * Normally, the device will do per protocol specific checksumming. Protocol
117 * implementations that do not want the NIC to perform the checksum
118 * calculation should use this flag in their outgoing skbs.
120 * NETIF_F_FCOE_CRC - This indicates that the device can do FCoE FC CRC
121 * offload. Correspondingly, the FCoE protocol driver
122 * stack should use CHECKSUM_UNNECESSARY.
124 * Any questions? No questions, good. --ANK
127 /* Don't change this without changing skb_csum_unnecessary! */
128 #define CHECKSUM_NONE 0
129 #define CHECKSUM_UNNECESSARY 1
130 #define CHECKSUM_COMPLETE 2
131 #define CHECKSUM_PARTIAL 3
133 /* Maximum value in skb->csum_level */
134 #define SKB_MAX_CSUM_LEVEL 3
136 #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES)
137 #define SKB_WITH_OVERHEAD(X) \
138 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
139 #define SKB_MAX_ORDER(X, ORDER) \
140 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
141 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
142 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
144 /* return minimum truesize of one skb containing X bytes of data */
145 #define SKB_TRUESIZE(X) ((X) + \
146 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
147 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
151 struct pipe_inode_info;
153 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
154 struct nf_conntrack {
159 #ifdef CONFIG_BRIDGE_NETFILTER
160 struct nf_bridge_info {
163 struct net_device *physindev;
164 struct net_device *physoutdev;
165 unsigned long data[32 / sizeof(unsigned long)];
169 struct sk_buff_head {
170 /* These two members must be first. */
171 struct sk_buff *next;
172 struct sk_buff *prev;
180 /* To allow 64K frame to be packed as single skb without frag_list we
181 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
182 * buffers which do not start on a page boundary.
184 * Since GRO uses frags we allocate at least 16 regardless of page
187 #if (65536/PAGE_SIZE + 1) < 16
188 #define MAX_SKB_FRAGS 16UL
190 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
193 typedef struct skb_frag_struct skb_frag_t;
195 struct skb_frag_struct {
199 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
208 static inline unsigned int skb_frag_size(const skb_frag_t *frag)
213 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
218 static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
223 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
228 #define HAVE_HW_TIME_STAMP
231 * struct skb_shared_hwtstamps - hardware time stamps
232 * @hwtstamp: hardware time stamp transformed into duration
233 * since arbitrary point in time
235 * Software time stamps generated by ktime_get_real() are stored in
238 * hwtstamps can only be compared against other hwtstamps from
241 * This structure is attached to packets as part of the
242 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
244 struct skb_shared_hwtstamps {
248 /* Definitions for tx_flags in struct skb_shared_info */
250 /* generate hardware time stamp */
251 SKBTX_HW_TSTAMP = 1 << 0,
253 /* generate software time stamp when queueing packet to NIC */
254 SKBTX_SW_TSTAMP = 1 << 1,
256 /* device driver is going to provide hardware time stamp */
257 SKBTX_IN_PROGRESS = 1 << 2,
259 /* device driver supports TX zero-copy buffers */
260 SKBTX_DEV_ZEROCOPY = 1 << 3,
262 /* generate wifi status information (where possible) */
263 SKBTX_WIFI_STATUS = 1 << 4,
265 /* This indicates at least one fragment might be overwritten
266 * (as in vmsplice(), sendfile() ...)
267 * If we need to compute a TX checksum, we'll need to copy
268 * all frags to avoid possible bad checksum
270 SKBTX_SHARED_FRAG = 1 << 5,
272 /* generate software time stamp when entering packet scheduling */
273 SKBTX_SCHED_TSTAMP = 1 << 6,
275 /* generate software timestamp on peer data acknowledgment */
276 SKBTX_ACK_TSTAMP = 1 << 7,
279 #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
280 SKBTX_SCHED_TSTAMP | \
282 #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
285 * The callback notifies userspace to release buffers when skb DMA is done in
286 * lower device, the skb last reference should be 0 when calling this.
287 * The zerocopy_success argument is true if zero copy transmit occurred,
288 * false on data copy or out of memory error caused by data copy attempt.
289 * The ctx field is used to track device context.
290 * The desc field is used to track userspace buffer index.
293 void (*callback)(struct ubuf_info *, bool zerocopy_success);
298 /* This data is invariant across clones and lives at
299 * the end of the header data, ie. at skb->end.
301 struct skb_shared_info {
302 unsigned char nr_frags;
304 unsigned short gso_size;
305 /* Warning: this field is not always filled in (UFO)! */
306 unsigned short gso_segs;
307 unsigned short gso_type;
308 struct sk_buff *frag_list;
309 struct skb_shared_hwtstamps hwtstamps;
314 * Warning : all fields before dataref are cleared in __alloc_skb()
318 /* Intermediate layers must ensure that destructor_arg
319 * remains valid until skb destructor */
320 void * destructor_arg;
322 /* must be last field, see pskb_expand_head() */
323 skb_frag_t frags[MAX_SKB_FRAGS];
326 /* We divide dataref into two halves. The higher 16 bits hold references
327 * to the payload part of skb->data. The lower 16 bits hold references to
328 * the entire skb->data. A clone of a headerless skb holds the length of
329 * the header in skb->hdr_len.
331 * All users must obey the rule that the skb->data reference count must be
332 * greater than or equal to the payload reference count.
334 * Holding a reference to the payload part means that the user does not
335 * care about modifications to the header part of skb->data.
337 #define SKB_DATAREF_SHIFT 16
338 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
342 SKB_FCLONE_UNAVAILABLE,
348 SKB_GSO_TCPV4 = 1 << 0,
349 SKB_GSO_UDP = 1 << 1,
351 /* This indicates the skb is from an untrusted source. */
352 SKB_GSO_DODGY = 1 << 2,
354 /* This indicates the tcp segment has CWR set. */
355 SKB_GSO_TCP_ECN = 1 << 3,
357 SKB_GSO_TCPV6 = 1 << 4,
359 SKB_GSO_FCOE = 1 << 5,
361 SKB_GSO_GRE = 1 << 6,
363 SKB_GSO_GRE_CSUM = 1 << 7,
365 SKB_GSO_IPIP = 1 << 8,
367 SKB_GSO_SIT = 1 << 9,
369 SKB_GSO_UDP_TUNNEL = 1 << 10,
371 SKB_GSO_UDP_TUNNEL_CSUM = 1 << 11,
373 SKB_GSO_MPLS = 1 << 12,
377 #if BITS_PER_LONG > 32
378 #define NET_SKBUFF_DATA_USES_OFFSET 1
381 #ifdef NET_SKBUFF_DATA_USES_OFFSET
382 typedef unsigned int sk_buff_data_t;
384 typedef unsigned char *sk_buff_data_t;
388 * struct skb_mstamp - multi resolution time stamps
389 * @stamp_us: timestamp in us resolution
390 * @stamp_jiffies: timestamp in jiffies
403 * skb_mstamp_get - get current timestamp
404 * @cl: place to store timestamps
406 static inline void skb_mstamp_get(struct skb_mstamp *cl)
408 u64 val = local_clock();
410 do_div(val, NSEC_PER_USEC);
411 cl->stamp_us = (u32)val;
412 cl->stamp_jiffies = (u32)jiffies;
416 * skb_mstamp_delta - compute the difference in usec between two skb_mstamp
417 * @t1: pointer to newest sample
418 * @t0: pointer to oldest sample
420 static inline u32 skb_mstamp_us_delta(const struct skb_mstamp *t1,
421 const struct skb_mstamp *t0)
423 s32 delta_us = t1->stamp_us - t0->stamp_us;
424 u32 delta_jiffies = t1->stamp_jiffies - t0->stamp_jiffies;
426 /* If delta_us is negative, this might be because interval is too big,
427 * or local_clock() drift is too big : fallback using jiffies.
430 delta_jiffies >= (INT_MAX / (USEC_PER_SEC / HZ)))
432 delta_us = jiffies_to_usecs(delta_jiffies);
439 * struct sk_buff - socket buffer
440 * @next: Next buffer in list
441 * @prev: Previous buffer in list
442 * @tstamp: Time we arrived/left
443 * @sk: Socket we are owned by
444 * @dev: Device we arrived on/are leaving by
445 * @cb: Control buffer. Free for use by every layer. Put private vars here
446 * @_skb_refdst: destination entry (with norefcount bit)
447 * @sp: the security path, used for xfrm
448 * @len: Length of actual data
449 * @data_len: Data length
450 * @mac_len: Length of link layer header
451 * @hdr_len: writable header length of cloned skb
452 * @csum: Checksum (must include start/offset pair)
453 * @csum_start: Offset from skb->head where checksumming should start
454 * @csum_offset: Offset from csum_start where checksum should be stored
455 * @priority: Packet queueing priority
456 * @ignore_df: allow local fragmentation
457 * @cloned: Head may be cloned (check refcnt to be sure)
458 * @ip_summed: Driver fed us an IP checksum
459 * @nohdr: Payload reference only, must not modify header
460 * @nfctinfo: Relationship of this skb to the connection
461 * @pkt_type: Packet class
462 * @fclone: skbuff clone status
463 * @ipvs_property: skbuff is owned by ipvs
464 * @peeked: this packet has been seen already, so stats have been
465 * done for it, don't do them again
466 * @nf_trace: netfilter packet trace flag
467 * @protocol: Packet protocol from driver
468 * @destructor: Destruct function
469 * @nfct: Associated connection, if any
470 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
471 * @skb_iif: ifindex of device we arrived on
472 * @tc_index: Traffic control index
473 * @tc_verd: traffic control verdict
474 * @hash: the packet hash
475 * @queue_mapping: Queue mapping for multiqueue devices
476 * @xmit_more: More SKBs are pending for this queue
477 * @ndisc_nodetype: router type (from link layer)
478 * @ooo_okay: allow the mapping of a socket to a queue to be changed
479 * @l4_hash: indicate hash is a canonical 4-tuple hash over transport
481 * @sw_hash: indicates hash was computed in software stack
482 * @wifi_acked_valid: wifi_acked was set
483 * @wifi_acked: whether frame was acked on wifi or not
484 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
485 * @dma_cookie: a cookie to one of several possible DMA operations
486 * done by skb DMA functions
487 * @napi_id: id of the NAPI struct this skb came from
488 * @secmark: security marking
489 * @mark: Generic packet mark
490 * @dropcount: total number of sk_receive_queue overflows
491 * @vlan_proto: vlan encapsulation protocol
492 * @vlan_tci: vlan tag control information
493 * @inner_protocol: Protocol (encapsulation)
494 * @inner_transport_header: Inner transport layer header (encapsulation)
495 * @inner_network_header: Network layer header (encapsulation)
496 * @inner_mac_header: Link layer header (encapsulation)
497 * @transport_header: Transport layer header
498 * @network_header: Network layer header
499 * @mac_header: Link layer header
500 * @tail: Tail pointer
502 * @head: Head of buffer
503 * @data: Data head pointer
504 * @truesize: Buffer size
505 * @users: User count - see {datagram,tcp}.c
509 /* These two members must be first. */
510 struct sk_buff *next;
511 struct sk_buff *prev;
515 struct skb_mstamp skb_mstamp;
519 struct net_device *dev;
522 * This is the control buffer. It is free to use for every
523 * layer. Please put your private variables there. If you
524 * want to keep them across layers you have to do a skb_clone()
525 * first. This is owned by whoever has the skb queued ATM.
527 char cb[48] __aligned(8);
529 unsigned long _skb_refdst;
545 kmemcheck_bitfield_begin(flags1);
556 kmemcheck_bitfield_end(flags1);
559 void (*destructor)(struct sk_buff *skb);
560 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
561 struct nf_conntrack *nfct;
563 #ifdef CONFIG_BRIDGE_NETFILTER
564 struct nf_bridge_info *nf_bridge;
574 #ifdef CONFIG_NET_SCHED
575 __u16 tc_index; /* traffic control index */
576 #ifdef CONFIG_NET_CLS_ACT
577 __u16 tc_verd; /* traffic control verdict */
582 kmemcheck_bitfield_begin(flags2);
584 #ifdef CONFIG_IPV6_NDISC_NODETYPE
585 __u8 ndisc_nodetype:2;
591 __u8 wifi_acked_valid:1;
595 /* Indicates the inner headers are valid in the skbuff. */
596 __u8 encapsulation:1;
597 __u8 encap_hdr_csum:1;
599 __u8 csum_complete_sw:1;
600 /* 1/3 bit hole (depending on ndisc_nodetype presence) */
601 kmemcheck_bitfield_end(flags2);
603 #if defined CONFIG_NET_DMA || defined CONFIG_NET_RX_BUSY_POLL
605 unsigned int napi_id;
606 dma_cookie_t dma_cookie;
609 #ifdef CONFIG_NETWORK_SECMARK
615 __u32 reserved_tailroom;
618 kmemcheck_bitfield_begin(flags3);
622 kmemcheck_bitfield_end(flags3);
624 __be16 inner_protocol;
625 __u16 inner_transport_header;
626 __u16 inner_network_header;
627 __u16 inner_mac_header;
628 __u16 transport_header;
629 __u16 network_header;
631 /* These elements must be at the end, see alloc_skb() for details. */
636 unsigned int truesize;
642 * Handling routines are only of interest to the kernel
644 #include <linux/slab.h>
647 #define SKB_ALLOC_FCLONE 0x01
648 #define SKB_ALLOC_RX 0x02
650 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
651 static inline bool skb_pfmemalloc(const struct sk_buff *skb)
653 return unlikely(skb->pfmemalloc);
657 * skb might have a dst pointer attached, refcounted or not.
658 * _skb_refdst low order bit is set if refcount was _not_ taken
660 #define SKB_DST_NOREF 1UL
661 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
664 * skb_dst - returns skb dst_entry
667 * Returns skb dst_entry, regardless of reference taken or not.
669 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
671 /* If refdst was not refcounted, check we still are in a
672 * rcu_read_lock section
674 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
675 !rcu_read_lock_held() &&
676 !rcu_read_lock_bh_held());
677 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
681 * skb_dst_set - sets skb dst
685 * Sets skb dst, assuming a reference was taken on dst and should
686 * be released by skb_dst_drop()
688 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
690 skb->_skb_refdst = (unsigned long)dst;
693 void __skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst,
697 * skb_dst_set_noref - sets skb dst, hopefully, without taking reference
701 * Sets skb dst, assuming a reference was not taken on dst.
702 * If dst entry is cached, we do not take reference and dst_release
703 * will be avoided by refdst_drop. If dst entry is not cached, we take
704 * reference, so that last dst_release can destroy the dst immediately.
706 static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst)
708 __skb_dst_set_noref(skb, dst, false);
712 * skb_dst_set_noref_force - sets skb dst, without taking reference
716 * Sets skb dst, assuming a reference was not taken on dst.
717 * No reference is taken and no dst_release will be called. While for
718 * cached dsts deferred reclaim is a basic feature, for entries that are
719 * not cached it is caller's job to guarantee that last dst_release for
720 * provided dst happens when nobody uses it, eg. after a RCU grace period.
722 static inline void skb_dst_set_noref_force(struct sk_buff *skb,
723 struct dst_entry *dst)
725 __skb_dst_set_noref(skb, dst, true);
729 * skb_dst_is_noref - Test if skb dst isn't refcounted
732 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
734 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
737 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
739 return (struct rtable *)skb_dst(skb);
742 void kfree_skb(struct sk_buff *skb);
743 void kfree_skb_list(struct sk_buff *segs);
744 void skb_tx_error(struct sk_buff *skb);
745 void consume_skb(struct sk_buff *skb);
746 void __kfree_skb(struct sk_buff *skb);
747 extern struct kmem_cache *skbuff_head_cache;
749 void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
750 bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
751 bool *fragstolen, int *delta_truesize);
753 struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags,
755 struct sk_buff *build_skb(void *data, unsigned int frag_size);
756 static inline struct sk_buff *alloc_skb(unsigned int size,
759 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
762 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
765 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
768 struct sk_buff *__alloc_skb_head(gfp_t priority, int node);
769 static inline struct sk_buff *alloc_skb_head(gfp_t priority)
771 return __alloc_skb_head(priority, -1);
774 struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
775 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
776 struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t priority);
777 struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t priority);
778 struct sk_buff *__pskb_copy_fclone(struct sk_buff *skb, int headroom,
779 gfp_t gfp_mask, bool fclone);
780 static inline struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom,
783 return __pskb_copy_fclone(skb, headroom, gfp_mask, false);
786 int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, gfp_t gfp_mask);
787 struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
788 unsigned int headroom);
789 struct sk_buff *skb_copy_expand(const struct sk_buff *skb, int newheadroom,
790 int newtailroom, gfp_t priority);
791 int skb_to_sgvec_nomark(struct sk_buff *skb, struct scatterlist *sg,
792 int offset, int len);
793 int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset,
795 int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
796 int skb_pad(struct sk_buff *skb, int pad);
797 #define dev_kfree_skb(a) consume_skb(a)
799 int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
800 int getfrag(void *from, char *to, int offset,
801 int len, int odd, struct sk_buff *skb),
802 void *from, int length);
804 struct skb_seq_state {
808 __u32 stepped_offset;
809 struct sk_buff *root_skb;
810 struct sk_buff *cur_skb;
814 void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
815 unsigned int to, struct skb_seq_state *st);
816 unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
817 struct skb_seq_state *st);
818 void skb_abort_seq_read(struct skb_seq_state *st);
820 unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
821 unsigned int to, struct ts_config *config,
822 struct ts_state *state);
825 * Packet hash types specify the type of hash in skb_set_hash.
827 * Hash types refer to the protocol layer addresses which are used to
828 * construct a packet's hash. The hashes are used to differentiate or identify
829 * flows of the protocol layer for the hash type. Hash types are either
830 * layer-2 (L2), layer-3 (L3), or layer-4 (L4).
832 * Properties of hashes:
834 * 1) Two packets in different flows have different hash values
835 * 2) Two packets in the same flow should have the same hash value
837 * A hash at a higher layer is considered to be more specific. A driver should
838 * set the most specific hash possible.
840 * A driver cannot indicate a more specific hash than the layer at which a hash
841 * was computed. For instance an L3 hash cannot be set as an L4 hash.
843 * A driver may indicate a hash level which is less specific than the
844 * actual layer the hash was computed on. For instance, a hash computed
845 * at L4 may be considered an L3 hash. This should only be done if the
846 * driver can't unambiguously determine that the HW computed the hash at
847 * the higher layer. Note that the "should" in the second property above
850 enum pkt_hash_types {
851 PKT_HASH_TYPE_NONE, /* Undefined type */
852 PKT_HASH_TYPE_L2, /* Input: src_MAC, dest_MAC */
853 PKT_HASH_TYPE_L3, /* Input: src_IP, dst_IP */
854 PKT_HASH_TYPE_L4, /* Input: src_IP, dst_IP, src_port, dst_port */
858 skb_set_hash(struct sk_buff *skb, __u32 hash, enum pkt_hash_types type)
860 skb->l4_hash = (type == PKT_HASH_TYPE_L4);
865 void __skb_get_hash(struct sk_buff *skb);
866 static inline __u32 skb_get_hash(struct sk_buff *skb)
868 if (!skb->l4_hash && !skb->sw_hash)
874 static inline __u32 skb_get_hash_raw(const struct sk_buff *skb)
879 static inline void skb_clear_hash(struct sk_buff *skb)
886 static inline void skb_clear_hash_if_not_l4(struct sk_buff *skb)
892 static inline void skb_copy_hash(struct sk_buff *to, const struct sk_buff *from)
894 to->hash = from->hash;
895 to->sw_hash = from->sw_hash;
896 to->l4_hash = from->l4_hash;
899 #ifdef NET_SKBUFF_DATA_USES_OFFSET
900 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
902 return skb->head + skb->end;
905 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
910 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
915 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
917 return skb->end - skb->head;
922 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
924 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
926 return &skb_shinfo(skb)->hwtstamps;
930 * skb_queue_empty - check if a queue is empty
933 * Returns true if the queue is empty, false otherwise.
935 static inline int skb_queue_empty(const struct sk_buff_head *list)
937 return list->next == (const struct sk_buff *) list;
941 * skb_queue_is_last - check if skb is the last entry in the queue
945 * Returns true if @skb is the last buffer on the list.
947 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
948 const struct sk_buff *skb)
950 return skb->next == (const struct sk_buff *) list;
954 * skb_queue_is_first - check if skb is the first entry in the queue
958 * Returns true if @skb is the first buffer on the list.
960 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
961 const struct sk_buff *skb)
963 return skb->prev == (const struct sk_buff *) list;
967 * skb_queue_next - return the next packet in the queue
969 * @skb: current buffer
971 * Return the next packet in @list after @skb. It is only valid to
972 * call this if skb_queue_is_last() evaluates to false.
974 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
975 const struct sk_buff *skb)
977 /* This BUG_ON may seem severe, but if we just return then we
978 * are going to dereference garbage.
980 BUG_ON(skb_queue_is_last(list, skb));
985 * skb_queue_prev - return the prev packet in the queue
987 * @skb: current buffer
989 * Return the prev packet in @list before @skb. It is only valid to
990 * call this if skb_queue_is_first() evaluates to false.
992 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
993 const struct sk_buff *skb)
995 /* This BUG_ON may seem severe, but if we just return then we
996 * are going to dereference garbage.
998 BUG_ON(skb_queue_is_first(list, skb));
1003 * skb_get - reference buffer
1004 * @skb: buffer to reference
1006 * Makes another reference to a socket buffer and returns a pointer
1009 static inline struct sk_buff *skb_get(struct sk_buff *skb)
1011 atomic_inc(&skb->users);
1016 * If users == 1, we are the only owner and are can avoid redundant
1021 * skb_cloned - is the buffer a clone
1022 * @skb: buffer to check
1024 * Returns true if the buffer was generated with skb_clone() and is
1025 * one of multiple shared copies of the buffer. Cloned buffers are
1026 * shared data so must not be written to under normal circumstances.
1028 static inline int skb_cloned(const struct sk_buff *skb)
1030 return skb->cloned &&
1031 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
1034 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
1036 might_sleep_if(pri & __GFP_WAIT);
1038 if (skb_cloned(skb))
1039 return pskb_expand_head(skb, 0, 0, pri);
1045 * skb_header_cloned - is the header a clone
1046 * @skb: buffer to check
1048 * Returns true if modifying the header part of the buffer requires
1049 * the data to be copied.
1051 static inline int skb_header_cloned(const struct sk_buff *skb)
1058 dataref = atomic_read(&skb_shinfo(skb)->dataref);
1059 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
1060 return dataref != 1;
1064 * skb_header_release - release reference to header
1065 * @skb: buffer to operate on
1067 * Drop a reference to the header part of the buffer. This is done
1068 * by acquiring a payload reference. You must not read from the header
1069 * part of skb->data after this.
1071 static inline void skb_header_release(struct sk_buff *skb)
1075 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
1079 * skb_shared - is the buffer shared
1080 * @skb: buffer to check
1082 * Returns true if more than one person has a reference to this
1085 static inline int skb_shared(const struct sk_buff *skb)
1087 return atomic_read(&skb->users) != 1;
1091 * skb_share_check - check if buffer is shared and if so clone it
1092 * @skb: buffer to check
1093 * @pri: priority for memory allocation
1095 * If the buffer is shared the buffer is cloned and the old copy
1096 * drops a reference. A new clone with a single reference is returned.
1097 * If the buffer is not shared the original buffer is returned. When
1098 * being called from interrupt status or with spinlocks held pri must
1101 * NULL is returned on a memory allocation failure.
1103 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
1105 might_sleep_if(pri & __GFP_WAIT);
1106 if (skb_shared(skb)) {
1107 struct sk_buff *nskb = skb_clone(skb, pri);
1119 * Copy shared buffers into a new sk_buff. We effectively do COW on
1120 * packets to handle cases where we have a local reader and forward
1121 * and a couple of other messy ones. The normal one is tcpdumping
1122 * a packet thats being forwarded.
1126 * skb_unshare - make a copy of a shared buffer
1127 * @skb: buffer to check
1128 * @pri: priority for memory allocation
1130 * If the socket buffer is a clone then this function creates a new
1131 * copy of the data, drops a reference count on the old copy and returns
1132 * the new copy with the reference count at 1. If the buffer is not a clone
1133 * the original buffer is returned. When called with a spinlock held or
1134 * from interrupt state @pri must be %GFP_ATOMIC
1136 * %NULL is returned on a memory allocation failure.
1138 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
1141 might_sleep_if(pri & __GFP_WAIT);
1142 if (skb_cloned(skb)) {
1143 struct sk_buff *nskb = skb_copy(skb, pri);
1144 kfree_skb(skb); /* Free our shared copy */
1151 * skb_peek - peek at the head of an &sk_buff_head
1152 * @list_: list to peek at
1154 * Peek an &sk_buff. Unlike most other operations you _MUST_
1155 * be careful with this one. A peek leaves the buffer on the
1156 * list and someone else may run off with it. You must hold
1157 * the appropriate locks or have a private queue to do this.
1159 * Returns %NULL for an empty list or a pointer to the head element.
1160 * The reference count is not incremented and the reference is therefore
1161 * volatile. Use with caution.
1163 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
1165 struct sk_buff *skb = list_->next;
1167 if (skb == (struct sk_buff *)list_)
1173 * skb_peek_next - peek skb following the given one from a queue
1174 * @skb: skb to start from
1175 * @list_: list to peek at
1177 * Returns %NULL when the end of the list is met or a pointer to the
1178 * next element. The reference count is not incremented and the
1179 * reference is therefore volatile. Use with caution.
1181 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
1182 const struct sk_buff_head *list_)
1184 struct sk_buff *next = skb->next;
1186 if (next == (struct sk_buff *)list_)
1192 * skb_peek_tail - peek at the tail of an &sk_buff_head
1193 * @list_: list to peek at
1195 * Peek an &sk_buff. Unlike most other operations you _MUST_
1196 * be careful with this one. A peek leaves the buffer on the
1197 * list and someone else may run off with it. You must hold
1198 * the appropriate locks or have a private queue to do this.
1200 * Returns %NULL for an empty list or a pointer to the tail element.
1201 * The reference count is not incremented and the reference is therefore
1202 * volatile. Use with caution.
1204 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
1206 struct sk_buff *skb = list_->prev;
1208 if (skb == (struct sk_buff *)list_)
1215 * skb_queue_len - get queue length
1216 * @list_: list to measure
1218 * Return the length of an &sk_buff queue.
1220 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
1226 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1227 * @list: queue to initialize
1229 * This initializes only the list and queue length aspects of
1230 * an sk_buff_head object. This allows to initialize the list
1231 * aspects of an sk_buff_head without reinitializing things like
1232 * the spinlock. It can also be used for on-stack sk_buff_head
1233 * objects where the spinlock is known to not be used.
1235 static inline void __skb_queue_head_init(struct sk_buff_head *list)
1237 list->prev = list->next = (struct sk_buff *)list;
1242 * This function creates a split out lock class for each invocation;
1243 * this is needed for now since a whole lot of users of the skb-queue
1244 * infrastructure in drivers have different locking usage (in hardirq)
1245 * than the networking core (in softirq only). In the long run either the
1246 * network layer or drivers should need annotation to consolidate the
1247 * main types of usage into 3 classes.
1249 static inline void skb_queue_head_init(struct sk_buff_head *list)
1251 spin_lock_init(&list->lock);
1252 __skb_queue_head_init(list);
1255 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
1256 struct lock_class_key *class)
1258 skb_queue_head_init(list);
1259 lockdep_set_class(&list->lock, class);
1263 * Insert an sk_buff on a list.
1265 * The "__skb_xxxx()" functions are the non-atomic ones that
1266 * can only be called with interrupts disabled.
1268 void skb_insert(struct sk_buff *old, struct sk_buff *newsk,
1269 struct sk_buff_head *list);
1270 static inline void __skb_insert(struct sk_buff *newsk,
1271 struct sk_buff *prev, struct sk_buff *next,
1272 struct sk_buff_head *list)
1276 next->prev = prev->next = newsk;
1280 static inline void __skb_queue_splice(const struct sk_buff_head *list,
1281 struct sk_buff *prev,
1282 struct sk_buff *next)
1284 struct sk_buff *first = list->next;
1285 struct sk_buff *last = list->prev;
1295 * skb_queue_splice - join two skb lists, this is designed for stacks
1296 * @list: the new list to add
1297 * @head: the place to add it in the first list
1299 static inline void skb_queue_splice(const struct sk_buff_head *list,
1300 struct sk_buff_head *head)
1302 if (!skb_queue_empty(list)) {
1303 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1304 head->qlen += list->qlen;
1309 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1310 * @list: the new list to add
1311 * @head: the place to add it in the first list
1313 * The list at @list is reinitialised
1315 static inline void skb_queue_splice_init(struct sk_buff_head *list,
1316 struct sk_buff_head *head)
1318 if (!skb_queue_empty(list)) {
1319 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1320 head->qlen += list->qlen;
1321 __skb_queue_head_init(list);
1326 * skb_queue_splice_tail - join two skb lists, each list being a queue
1327 * @list: the new list to add
1328 * @head: the place to add it in the first list
1330 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1331 struct sk_buff_head *head)
1333 if (!skb_queue_empty(list)) {
1334 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1335 head->qlen += list->qlen;
1340 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1341 * @list: the new list to add
1342 * @head: the place to add it in the first list
1344 * Each of the lists is a queue.
1345 * The list at @list is reinitialised
1347 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
1348 struct sk_buff_head *head)
1350 if (!skb_queue_empty(list)) {
1351 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1352 head->qlen += list->qlen;
1353 __skb_queue_head_init(list);
1358 * __skb_queue_after - queue a buffer at the list head
1359 * @list: list to use
1360 * @prev: place after this buffer
1361 * @newsk: buffer to queue
1363 * Queue a buffer int the middle of a list. This function takes no locks
1364 * and you must therefore hold required locks before calling it.
1366 * A buffer cannot be placed on two lists at the same time.
1368 static inline void __skb_queue_after(struct sk_buff_head *list,
1369 struct sk_buff *prev,
1370 struct sk_buff *newsk)
1372 __skb_insert(newsk, prev, prev->next, list);
1375 void skb_append(struct sk_buff *old, struct sk_buff *newsk,
1376 struct sk_buff_head *list);
1378 static inline void __skb_queue_before(struct sk_buff_head *list,
1379 struct sk_buff *next,
1380 struct sk_buff *newsk)
1382 __skb_insert(newsk, next->prev, next, list);
1386 * __skb_queue_head - queue a buffer at the list head
1387 * @list: list to use
1388 * @newsk: buffer to queue
1390 * Queue a buffer at the start of a list. This function takes no locks
1391 * and you must therefore hold required locks before calling it.
1393 * A buffer cannot be placed on two lists at the same time.
1395 void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
1396 static inline void __skb_queue_head(struct sk_buff_head *list,
1397 struct sk_buff *newsk)
1399 __skb_queue_after(list, (struct sk_buff *)list, newsk);
1403 * __skb_queue_tail - queue a buffer at the list tail
1404 * @list: list to use
1405 * @newsk: buffer to queue
1407 * Queue a buffer at the end of a list. This function takes no locks
1408 * and you must therefore hold required locks before calling it.
1410 * A buffer cannot be placed on two lists at the same time.
1412 void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
1413 static inline void __skb_queue_tail(struct sk_buff_head *list,
1414 struct sk_buff *newsk)
1416 __skb_queue_before(list, (struct sk_buff *)list, newsk);
1420 * remove sk_buff from list. _Must_ be called atomically, and with
1423 void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
1424 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
1426 struct sk_buff *next, *prev;
1431 skb->next = skb->prev = NULL;
1437 * __skb_dequeue - remove from the head of the queue
1438 * @list: list to dequeue from
1440 * Remove the head of the list. This function does not take any locks
1441 * so must be used with appropriate locks held only. The head item is
1442 * returned or %NULL if the list is empty.
1444 struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1445 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1447 struct sk_buff *skb = skb_peek(list);
1449 __skb_unlink(skb, list);
1454 * __skb_dequeue_tail - remove from the tail of the queue
1455 * @list: list to dequeue from
1457 * Remove the tail of the list. This function does not take any locks
1458 * so must be used with appropriate locks held only. The tail item is
1459 * returned or %NULL if the list is empty.
1461 struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1462 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1464 struct sk_buff *skb = skb_peek_tail(list);
1466 __skb_unlink(skb, list);
1471 static inline bool skb_is_nonlinear(const struct sk_buff *skb)
1473 return skb->data_len;
1476 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1478 return skb->len - skb->data_len;
1481 static inline int skb_pagelen(const struct sk_buff *skb)
1485 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1486 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
1487 return len + skb_headlen(skb);
1491 * __skb_fill_page_desc - initialise a paged fragment in an skb
1492 * @skb: buffer containing fragment to be initialised
1493 * @i: paged fragment index to initialise
1494 * @page: the page to use for this fragment
1495 * @off: the offset to the data with @page
1496 * @size: the length of the data
1498 * Initialises the @i'th fragment of @skb to point to &size bytes at
1499 * offset @off within @page.
1501 * Does not take any additional reference on the fragment.
1503 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
1504 struct page *page, int off, int size)
1506 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1509 * Propagate page->pfmemalloc to the skb if we can. The problem is
1510 * that not all callers have unique ownership of the page. If
1511 * pfmemalloc is set, we check the mapping as a mapping implies
1512 * page->index is set (index and pfmemalloc share space).
1513 * If it's a valid mapping, we cannot use page->pfmemalloc but we
1514 * do not lose pfmemalloc information as the pages would not be
1515 * allocated using __GFP_MEMALLOC.
1517 frag->page.p = page;
1518 frag->page_offset = off;
1519 skb_frag_size_set(frag, size);
1521 page = compound_head(page);
1522 if (page->pfmemalloc && !page->mapping)
1523 skb->pfmemalloc = true;
1527 * skb_fill_page_desc - initialise a paged fragment in an skb
1528 * @skb: buffer containing fragment to be initialised
1529 * @i: paged fragment index to initialise
1530 * @page: the page to use for this fragment
1531 * @off: the offset to the data with @page
1532 * @size: the length of the data
1534 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1535 * @skb to point to @size bytes at offset @off within @page. In
1536 * addition updates @skb such that @i is the last fragment.
1538 * Does not take any additional reference on the fragment.
1540 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1541 struct page *page, int off, int size)
1543 __skb_fill_page_desc(skb, i, page, off, size);
1544 skb_shinfo(skb)->nr_frags = i + 1;
1547 void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off,
1548 int size, unsigned int truesize);
1550 void skb_coalesce_rx_frag(struct sk_buff *skb, int i, int size,
1551 unsigned int truesize);
1553 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1554 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1555 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1557 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1558 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1560 return skb->head + skb->tail;
1563 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1565 skb->tail = skb->data - skb->head;
1568 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1570 skb_reset_tail_pointer(skb);
1571 skb->tail += offset;
1574 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1575 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1580 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1582 skb->tail = skb->data;
1585 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1587 skb->tail = skb->data + offset;
1590 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1593 * Add data to an sk_buff
1595 unsigned char *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
1596 unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1597 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1599 unsigned char *tmp = skb_tail_pointer(skb);
1600 SKB_LINEAR_ASSERT(skb);
1606 unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1607 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1614 unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1615 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1618 BUG_ON(skb->len < skb->data_len);
1619 return skb->data += len;
1622 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len)
1624 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
1627 unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1629 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1631 if (len > skb_headlen(skb) &&
1632 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1635 return skb->data += len;
1638 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1640 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1643 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1645 if (likely(len <= skb_headlen(skb)))
1647 if (unlikely(len > skb->len))
1649 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1653 * skb_headroom - bytes at buffer head
1654 * @skb: buffer to check
1656 * Return the number of bytes of free space at the head of an &sk_buff.
1658 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1660 return skb->data - skb->head;
1664 * skb_tailroom - bytes at buffer end
1665 * @skb: buffer to check
1667 * Return the number of bytes of free space at the tail of an sk_buff
1669 static inline int skb_tailroom(const struct sk_buff *skb)
1671 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1675 * skb_availroom - bytes at buffer end
1676 * @skb: buffer to check
1678 * Return the number of bytes of free space at the tail of an sk_buff
1679 * allocated by sk_stream_alloc()
1681 static inline int skb_availroom(const struct sk_buff *skb)
1683 if (skb_is_nonlinear(skb))
1686 return skb->end - skb->tail - skb->reserved_tailroom;
1690 * skb_reserve - adjust headroom
1691 * @skb: buffer to alter
1692 * @len: bytes to move
1694 * Increase the headroom of an empty &sk_buff by reducing the tail
1695 * room. This is only allowed for an empty buffer.
1697 static inline void skb_reserve(struct sk_buff *skb, int len)
1703 static inline void skb_reset_inner_headers(struct sk_buff *skb)
1705 skb->inner_mac_header = skb->mac_header;
1706 skb->inner_network_header = skb->network_header;
1707 skb->inner_transport_header = skb->transport_header;
1710 static inline void skb_reset_mac_len(struct sk_buff *skb)
1712 skb->mac_len = skb->network_header - skb->mac_header;
1715 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1718 return skb->head + skb->inner_transport_header;
1721 static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
1723 skb->inner_transport_header = skb->data - skb->head;
1726 static inline void skb_set_inner_transport_header(struct sk_buff *skb,
1729 skb_reset_inner_transport_header(skb);
1730 skb->inner_transport_header += offset;
1733 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
1735 return skb->head + skb->inner_network_header;
1738 static inline void skb_reset_inner_network_header(struct sk_buff *skb)
1740 skb->inner_network_header = skb->data - skb->head;
1743 static inline void skb_set_inner_network_header(struct sk_buff *skb,
1746 skb_reset_inner_network_header(skb);
1747 skb->inner_network_header += offset;
1750 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
1752 return skb->head + skb->inner_mac_header;
1755 static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
1757 skb->inner_mac_header = skb->data - skb->head;
1760 static inline void skb_set_inner_mac_header(struct sk_buff *skb,
1763 skb_reset_inner_mac_header(skb);
1764 skb->inner_mac_header += offset;
1766 static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
1768 return skb->transport_header != (typeof(skb->transport_header))~0U;
1771 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1773 return skb->head + skb->transport_header;
1776 static inline void skb_reset_transport_header(struct sk_buff *skb)
1778 skb->transport_header = skb->data - skb->head;
1781 static inline void skb_set_transport_header(struct sk_buff *skb,
1784 skb_reset_transport_header(skb);
1785 skb->transport_header += offset;
1788 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1790 return skb->head + skb->network_header;
1793 static inline void skb_reset_network_header(struct sk_buff *skb)
1795 skb->network_header = skb->data - skb->head;
1798 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1800 skb_reset_network_header(skb);
1801 skb->network_header += offset;
1804 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1806 return skb->head + skb->mac_header;
1809 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1811 return skb->mac_header != (typeof(skb->mac_header))~0U;
1814 static inline void skb_reset_mac_header(struct sk_buff *skb)
1816 skb->mac_header = skb->data - skb->head;
1819 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1821 skb_reset_mac_header(skb);
1822 skb->mac_header += offset;
1825 static inline void skb_pop_mac_header(struct sk_buff *skb)
1827 skb->mac_header = skb->network_header;
1830 static inline void skb_probe_transport_header(struct sk_buff *skb,
1831 const int offset_hint)
1833 struct flow_keys keys;
1835 if (skb_transport_header_was_set(skb))
1837 else if (skb_flow_dissect(skb, &keys))
1838 skb_set_transport_header(skb, keys.thoff);
1840 skb_set_transport_header(skb, offset_hint);
1843 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
1845 if (skb_mac_header_was_set(skb)) {
1846 const unsigned char *old_mac = skb_mac_header(skb);
1848 skb_set_mac_header(skb, -skb->mac_len);
1849 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
1853 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
1855 return skb->csum_start - skb_headroom(skb);
1858 static inline int skb_transport_offset(const struct sk_buff *skb)
1860 return skb_transport_header(skb) - skb->data;
1863 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1865 return skb->transport_header - skb->network_header;
1868 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb)
1870 return skb->inner_transport_header - skb->inner_network_header;
1873 static inline int skb_network_offset(const struct sk_buff *skb)
1875 return skb_network_header(skb) - skb->data;
1878 static inline int skb_inner_network_offset(const struct sk_buff *skb)
1880 return skb_inner_network_header(skb) - skb->data;
1883 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
1885 return pskb_may_pull(skb, skb_network_offset(skb) + len);
1889 * CPUs often take a performance hit when accessing unaligned memory
1890 * locations. The actual performance hit varies, it can be small if the
1891 * hardware handles it or large if we have to take an exception and fix it
1894 * Since an ethernet header is 14 bytes network drivers often end up with
1895 * the IP header at an unaligned offset. The IP header can be aligned by
1896 * shifting the start of the packet by 2 bytes. Drivers should do this
1899 * skb_reserve(skb, NET_IP_ALIGN);
1901 * The downside to this alignment of the IP header is that the DMA is now
1902 * unaligned. On some architectures the cost of an unaligned DMA is high
1903 * and this cost outweighs the gains made by aligning the IP header.
1905 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1908 #ifndef NET_IP_ALIGN
1909 #define NET_IP_ALIGN 2
1913 * The networking layer reserves some headroom in skb data (via
1914 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1915 * the header has to grow. In the default case, if the header has to grow
1916 * 32 bytes or less we avoid the reallocation.
1918 * Unfortunately this headroom changes the DMA alignment of the resulting
1919 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1920 * on some architectures. An architecture can override this value,
1921 * perhaps setting it to a cacheline in size (since that will maintain
1922 * cacheline alignment of the DMA). It must be a power of 2.
1924 * Various parts of the networking layer expect at least 32 bytes of
1925 * headroom, you should not reduce this.
1927 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1928 * to reduce average number of cache lines per packet.
1929 * get_rps_cpus() for example only access one 64 bytes aligned block :
1930 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1933 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1936 int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1938 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1940 if (unlikely(skb_is_nonlinear(skb))) {
1945 skb_set_tail_pointer(skb, len);
1948 void skb_trim(struct sk_buff *skb, unsigned int len);
1950 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1953 return ___pskb_trim(skb, len);
1954 __skb_trim(skb, len);
1958 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1960 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1964 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1965 * @skb: buffer to alter
1968 * This is identical to pskb_trim except that the caller knows that
1969 * the skb is not cloned so we should never get an error due to out-
1972 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1974 int err = pskb_trim(skb, len);
1979 * skb_orphan - orphan a buffer
1980 * @skb: buffer to orphan
1982 * If a buffer currently has an owner then we call the owner's
1983 * destructor function and make the @skb unowned. The buffer continues
1984 * to exist but is no longer charged to its former owner.
1986 static inline void skb_orphan(struct sk_buff *skb)
1988 if (skb->destructor) {
1989 skb->destructor(skb);
1990 skb->destructor = NULL;
1998 * skb_orphan_frags - orphan the frags contained in a buffer
1999 * @skb: buffer to orphan frags from
2000 * @gfp_mask: allocation mask for replacement pages
2002 * For each frag in the SKB which needs a destructor (i.e. has an
2003 * owner) create a copy of that frag and release the original
2004 * page by calling the destructor.
2006 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
2008 if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY)))
2010 return skb_copy_ubufs(skb, gfp_mask);
2014 * __skb_queue_purge - empty a list
2015 * @list: list to empty
2017 * Delete all buffers on an &sk_buff list. Each buffer is removed from
2018 * the list and one reference dropped. This function does not take the
2019 * list lock and the caller must hold the relevant locks to use it.
2021 void skb_queue_purge(struct sk_buff_head *list);
2022 static inline void __skb_queue_purge(struct sk_buff_head *list)
2024 struct sk_buff *skb;
2025 while ((skb = __skb_dequeue(list)) != NULL)
2029 #define NETDEV_FRAG_PAGE_MAX_ORDER get_order(32768)
2030 #define NETDEV_FRAG_PAGE_MAX_SIZE (PAGE_SIZE << NETDEV_FRAG_PAGE_MAX_ORDER)
2031 #define NETDEV_PAGECNT_MAX_BIAS NETDEV_FRAG_PAGE_MAX_SIZE
2033 void *netdev_alloc_frag(unsigned int fragsz);
2035 struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int length,
2039 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
2040 * @dev: network device to receive on
2041 * @length: length to allocate
2043 * Allocate a new &sk_buff and assign it a usage count of one. The
2044 * buffer has unspecified headroom built in. Users should allocate
2045 * the headroom they think they need without accounting for the
2046 * built in space. The built in space is used for optimisations.
2048 * %NULL is returned if there is no free memory. Although this function
2049 * allocates memory it can be called from an interrupt.
2051 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
2052 unsigned int length)
2054 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
2057 /* legacy helper around __netdev_alloc_skb() */
2058 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
2061 return __netdev_alloc_skb(NULL, length, gfp_mask);
2064 /* legacy helper around netdev_alloc_skb() */
2065 static inline struct sk_buff *dev_alloc_skb(unsigned int length)
2067 return netdev_alloc_skb(NULL, length);
2071 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
2072 unsigned int length, gfp_t gfp)
2074 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
2076 if (NET_IP_ALIGN && skb)
2077 skb_reserve(skb, NET_IP_ALIGN);
2081 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
2082 unsigned int length)
2084 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
2088 * __skb_alloc_pages - allocate pages for ps-rx on a skb and preserve pfmemalloc data
2089 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
2090 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
2091 * @order: size of the allocation
2093 * Allocate a new page.
2095 * %NULL is returned if there is no free memory.
2097 static inline struct page *__skb_alloc_pages(gfp_t gfp_mask,
2098 struct sk_buff *skb,
2103 gfp_mask |= __GFP_COLD;
2105 if (!(gfp_mask & __GFP_NOMEMALLOC))
2106 gfp_mask |= __GFP_MEMALLOC;
2108 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
2109 if (skb && page && page->pfmemalloc)
2110 skb->pfmemalloc = true;
2116 * __skb_alloc_page - allocate a page for ps-rx for a given skb and preserve pfmemalloc data
2117 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
2118 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
2120 * Allocate a new page.
2122 * %NULL is returned if there is no free memory.
2124 static inline struct page *__skb_alloc_page(gfp_t gfp_mask,
2125 struct sk_buff *skb)
2127 return __skb_alloc_pages(gfp_mask, skb, 0);
2131 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
2132 * @page: The page that was allocated from skb_alloc_page
2133 * @skb: The skb that may need pfmemalloc set
2135 static inline void skb_propagate_pfmemalloc(struct page *page,
2136 struct sk_buff *skb)
2138 if (page && page->pfmemalloc)
2139 skb->pfmemalloc = true;
2143 * skb_frag_page - retrieve the page referred to by a paged fragment
2144 * @frag: the paged fragment
2146 * Returns the &struct page associated with @frag.
2148 static inline struct page *skb_frag_page(const skb_frag_t *frag)
2150 return frag->page.p;
2154 * __skb_frag_ref - take an addition reference on a paged fragment.
2155 * @frag: the paged fragment
2157 * Takes an additional reference on the paged fragment @frag.
2159 static inline void __skb_frag_ref(skb_frag_t *frag)
2161 get_page(skb_frag_page(frag));
2165 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
2167 * @f: the fragment offset.
2169 * Takes an additional reference on the @f'th paged fragment of @skb.
2171 static inline void skb_frag_ref(struct sk_buff *skb, int f)
2173 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
2177 * __skb_frag_unref - release a reference on a paged fragment.
2178 * @frag: the paged fragment
2180 * Releases a reference on the paged fragment @frag.
2182 static inline void __skb_frag_unref(skb_frag_t *frag)
2184 put_page(skb_frag_page(frag));
2188 * skb_frag_unref - release a reference on a paged fragment of an skb.
2190 * @f: the fragment offset
2192 * Releases a reference on the @f'th paged fragment of @skb.
2194 static inline void skb_frag_unref(struct sk_buff *skb, int f)
2196 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
2200 * skb_frag_address - gets the address of the data contained in a paged fragment
2201 * @frag: the paged fragment buffer
2203 * Returns the address of the data within @frag. The page must already
2206 static inline void *skb_frag_address(const skb_frag_t *frag)
2208 return page_address(skb_frag_page(frag)) + frag->page_offset;
2212 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2213 * @frag: the paged fragment buffer
2215 * Returns the address of the data within @frag. Checks that the page
2216 * is mapped and returns %NULL otherwise.
2218 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
2220 void *ptr = page_address(skb_frag_page(frag));
2224 return ptr + frag->page_offset;
2228 * __skb_frag_set_page - sets the page contained in a paged fragment
2229 * @frag: the paged fragment
2230 * @page: the page to set
2232 * Sets the fragment @frag to contain @page.
2234 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
2236 frag->page.p = page;
2240 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2242 * @f: the fragment offset
2243 * @page: the page to set
2245 * Sets the @f'th fragment of @skb to contain @page.
2247 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
2250 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
2253 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio);
2256 * skb_frag_dma_map - maps a paged fragment via the DMA API
2257 * @dev: the device to map the fragment to
2258 * @frag: the paged fragment to map
2259 * @offset: the offset within the fragment (starting at the
2260 * fragment's own offset)
2261 * @size: the number of bytes to map
2262 * @dir: the direction of the mapping (%PCI_DMA_*)
2264 * Maps the page associated with @frag to @device.
2266 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
2267 const skb_frag_t *frag,
2268 size_t offset, size_t size,
2269 enum dma_data_direction dir)
2271 return dma_map_page(dev, skb_frag_page(frag),
2272 frag->page_offset + offset, size, dir);
2275 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
2278 return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
2282 static inline struct sk_buff *pskb_copy_for_clone(struct sk_buff *skb,
2285 return __pskb_copy_fclone(skb, skb_headroom(skb), gfp_mask, true);
2290 * skb_clone_writable - is the header of a clone writable
2291 * @skb: buffer to check
2292 * @len: length up to which to write
2294 * Returns true if modifying the header part of the cloned buffer
2295 * does not requires the data to be copied.
2297 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
2299 return !skb_header_cloned(skb) &&
2300 skb_headroom(skb) + len <= skb->hdr_len;
2303 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
2308 if (headroom > skb_headroom(skb))
2309 delta = headroom - skb_headroom(skb);
2311 if (delta || cloned)
2312 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
2318 * skb_cow - copy header of skb when it is required
2319 * @skb: buffer to cow
2320 * @headroom: needed headroom
2322 * If the skb passed lacks sufficient headroom or its data part
2323 * is shared, data is reallocated. If reallocation fails, an error
2324 * is returned and original skb is not changed.
2326 * The result is skb with writable area skb->head...skb->tail
2327 * and at least @headroom of space at head.
2329 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
2331 return __skb_cow(skb, headroom, skb_cloned(skb));
2335 * skb_cow_head - skb_cow but only making the head writable
2336 * @skb: buffer to cow
2337 * @headroom: needed headroom
2339 * This function is identical to skb_cow except that we replace the
2340 * skb_cloned check by skb_header_cloned. It should be used when
2341 * you only need to push on some header and do not need to modify
2344 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
2346 return __skb_cow(skb, headroom, skb_header_cloned(skb));
2350 * skb_padto - pad an skbuff up to a minimal size
2351 * @skb: buffer to pad
2352 * @len: minimal length
2354 * Pads up a buffer to ensure the trailing bytes exist and are
2355 * blanked. If the buffer already contains sufficient data it
2356 * is untouched. Otherwise it is extended. Returns zero on
2357 * success. The skb is freed on error.
2360 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
2362 unsigned int size = skb->len;
2363 if (likely(size >= len))
2365 return skb_pad(skb, len - size);
2368 static inline int skb_add_data(struct sk_buff *skb,
2369 char __user *from, int copy)
2371 const int off = skb->len;
2373 if (skb->ip_summed == CHECKSUM_NONE) {
2375 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
2378 skb->csum = csum_block_add(skb->csum, csum, off);
2381 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
2384 __skb_trim(skb, off);
2388 static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
2389 const struct page *page, int off)
2392 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
2394 return page == skb_frag_page(frag) &&
2395 off == frag->page_offset + skb_frag_size(frag);
2400 static inline int __skb_linearize(struct sk_buff *skb)
2402 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
2406 * skb_linearize - convert paged skb to linear one
2407 * @skb: buffer to linarize
2409 * If there is no free memory -ENOMEM is returned, otherwise zero
2410 * is returned and the old skb data released.
2412 static inline int skb_linearize(struct sk_buff *skb)
2414 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
2418 * skb_has_shared_frag - can any frag be overwritten
2419 * @skb: buffer to test
2421 * Return true if the skb has at least one frag that might be modified
2422 * by an external entity (as in vmsplice()/sendfile())
2424 static inline bool skb_has_shared_frag(const struct sk_buff *skb)
2426 return skb_is_nonlinear(skb) &&
2427 skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
2431 * skb_linearize_cow - make sure skb is linear and writable
2432 * @skb: buffer to process
2434 * If there is no free memory -ENOMEM is returned, otherwise zero
2435 * is returned and the old skb data released.
2437 static inline int skb_linearize_cow(struct sk_buff *skb)
2439 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
2440 __skb_linearize(skb) : 0;
2444 * skb_postpull_rcsum - update checksum for received skb after pull
2445 * @skb: buffer to update
2446 * @start: start of data before pull
2447 * @len: length of data pulled
2449 * After doing a pull on a received packet, you need to call this to
2450 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2451 * CHECKSUM_NONE so that it can be recomputed from scratch.
2454 static inline void skb_postpull_rcsum(struct sk_buff *skb,
2455 const void *start, unsigned int len)
2457 if (skb->ip_summed == CHECKSUM_COMPLETE)
2458 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
2461 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
2464 * pskb_trim_rcsum - trim received skb and update checksum
2465 * @skb: buffer to trim
2468 * This is exactly the same as pskb_trim except that it ensures the
2469 * checksum of received packets are still valid after the operation.
2472 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
2474 if (likely(len >= skb->len))
2476 if (skb->ip_summed == CHECKSUM_COMPLETE)
2477 skb->ip_summed = CHECKSUM_NONE;
2478 return __pskb_trim(skb, len);
2481 #define skb_queue_walk(queue, skb) \
2482 for (skb = (queue)->next; \
2483 skb != (struct sk_buff *)(queue); \
2486 #define skb_queue_walk_safe(queue, skb, tmp) \
2487 for (skb = (queue)->next, tmp = skb->next; \
2488 skb != (struct sk_buff *)(queue); \
2489 skb = tmp, tmp = skb->next)
2491 #define skb_queue_walk_from(queue, skb) \
2492 for (; skb != (struct sk_buff *)(queue); \
2495 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2496 for (tmp = skb->next; \
2497 skb != (struct sk_buff *)(queue); \
2498 skb = tmp, tmp = skb->next)
2500 #define skb_queue_reverse_walk(queue, skb) \
2501 for (skb = (queue)->prev; \
2502 skb != (struct sk_buff *)(queue); \
2505 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2506 for (skb = (queue)->prev, tmp = skb->prev; \
2507 skb != (struct sk_buff *)(queue); \
2508 skb = tmp, tmp = skb->prev)
2510 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2511 for (tmp = skb->prev; \
2512 skb != (struct sk_buff *)(queue); \
2513 skb = tmp, tmp = skb->prev)
2515 static inline bool skb_has_frag_list(const struct sk_buff *skb)
2517 return skb_shinfo(skb)->frag_list != NULL;
2520 static inline void skb_frag_list_init(struct sk_buff *skb)
2522 skb_shinfo(skb)->frag_list = NULL;
2525 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
2527 frag->next = skb_shinfo(skb)->frag_list;
2528 skb_shinfo(skb)->frag_list = frag;
2531 #define skb_walk_frags(skb, iter) \
2532 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2534 struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
2535 int *peeked, int *off, int *err);
2536 struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock,
2538 unsigned int datagram_poll(struct file *file, struct socket *sock,
2539 struct poll_table_struct *wait);
2540 int skb_copy_datagram_iovec(const struct sk_buff *from, int offset,
2541 struct iovec *to, int size);
2542 int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, int hlen,
2544 int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset,
2545 const struct iovec *from, int from_offset,
2547 int zerocopy_sg_from_iovec(struct sk_buff *skb, const struct iovec *frm,
2548 int offset, size_t count);
2549 int skb_copy_datagram_const_iovec(const struct sk_buff *from, int offset,
2550 const struct iovec *to, int to_offset,
2552 void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
2553 void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb);
2554 int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags);
2555 int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len);
2556 int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len);
2557 __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, u8 *to,
2558 int len, __wsum csum);
2559 int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
2560 struct pipe_inode_info *pipe, unsigned int len,
2561 unsigned int flags);
2562 void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
2563 unsigned int skb_zerocopy_headlen(const struct sk_buff *from);
2564 int skb_zerocopy(struct sk_buff *to, struct sk_buff *from,
2566 void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len);
2567 int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen);
2568 void skb_scrub_packet(struct sk_buff *skb, bool xnet);
2569 unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
2570 struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features);
2571 struct sk_buff *skb_vlan_untag(struct sk_buff *skb);
2573 struct skb_checksum_ops {
2574 __wsum (*update)(const void *mem, int len, __wsum wsum);
2575 __wsum (*combine)(__wsum csum, __wsum csum2, int offset, int len);
2578 __wsum __skb_checksum(const struct sk_buff *skb, int offset, int len,
2579 __wsum csum, const struct skb_checksum_ops *ops);
2580 __wsum skb_checksum(const struct sk_buff *skb, int offset, int len,
2583 static inline void *__skb_header_pointer(const struct sk_buff *skb, int offset,
2584 int len, void *data, int hlen, void *buffer)
2586 if (hlen - offset >= len)
2587 return data + offset;
2590 skb_copy_bits(skb, offset, buffer, len) < 0)
2596 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
2597 int len, void *buffer)
2599 return __skb_header_pointer(skb, offset, len, skb->data,
2600 skb_headlen(skb), buffer);
2604 * skb_needs_linearize - check if we need to linearize a given skb
2605 * depending on the given device features.
2606 * @skb: socket buffer to check
2607 * @features: net device features
2609 * Returns true if either:
2610 * 1. skb has frag_list and the device doesn't support FRAGLIST, or
2611 * 2. skb is fragmented and the device does not support SG.
2613 static inline bool skb_needs_linearize(struct sk_buff *skb,
2614 netdev_features_t features)
2616 return skb_is_nonlinear(skb) &&
2617 ((skb_has_frag_list(skb) && !(features & NETIF_F_FRAGLIST)) ||
2618 (skb_shinfo(skb)->nr_frags && !(features & NETIF_F_SG)));
2621 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
2623 const unsigned int len)
2625 memcpy(to, skb->data, len);
2628 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
2629 const int offset, void *to,
2630 const unsigned int len)
2632 memcpy(to, skb->data + offset, len);
2635 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
2637 const unsigned int len)
2639 memcpy(skb->data, from, len);
2642 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
2645 const unsigned int len)
2647 memcpy(skb->data + offset, from, len);
2650 void skb_init(void);
2652 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
2658 * skb_get_timestamp - get timestamp from a skb
2659 * @skb: skb to get stamp from
2660 * @stamp: pointer to struct timeval to store stamp in
2662 * Timestamps are stored in the skb as offsets to a base timestamp.
2663 * This function converts the offset back to a struct timeval and stores
2666 static inline void skb_get_timestamp(const struct sk_buff *skb,
2667 struct timeval *stamp)
2669 *stamp = ktime_to_timeval(skb->tstamp);
2672 static inline void skb_get_timestampns(const struct sk_buff *skb,
2673 struct timespec *stamp)
2675 *stamp = ktime_to_timespec(skb->tstamp);
2678 static inline void __net_timestamp(struct sk_buff *skb)
2680 skb->tstamp = ktime_get_real();
2683 static inline ktime_t net_timedelta(ktime_t t)
2685 return ktime_sub(ktime_get_real(), t);
2688 static inline ktime_t net_invalid_timestamp(void)
2690 return ktime_set(0, 0);
2693 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2695 void skb_clone_tx_timestamp(struct sk_buff *skb);
2696 bool skb_defer_rx_timestamp(struct sk_buff *skb);
2698 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2700 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
2704 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
2709 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2712 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2714 * PHY drivers may accept clones of transmitted packets for
2715 * timestamping via their phy_driver.txtstamp method. These drivers
2716 * must call this function to return the skb back to the stack, with
2717 * or without a timestamp.
2719 * @skb: clone of the the original outgoing packet
2720 * @hwtstamps: hardware time stamps, may be NULL if not available
2723 void skb_complete_tx_timestamp(struct sk_buff *skb,
2724 struct skb_shared_hwtstamps *hwtstamps);
2726 void __skb_tstamp_tx(struct sk_buff *orig_skb,
2727 struct skb_shared_hwtstamps *hwtstamps,
2728 struct sock *sk, int tstype);
2731 * skb_tstamp_tx - queue clone of skb with send time stamps
2732 * @orig_skb: the original outgoing packet
2733 * @hwtstamps: hardware time stamps, may be NULL if not available
2735 * If the skb has a socket associated, then this function clones the
2736 * skb (thus sharing the actual data and optional structures), stores
2737 * the optional hardware time stamping information (if non NULL) or
2738 * generates a software time stamp (otherwise), then queues the clone
2739 * to the error queue of the socket. Errors are silently ignored.
2741 void skb_tstamp_tx(struct sk_buff *orig_skb,
2742 struct skb_shared_hwtstamps *hwtstamps);
2744 static inline void sw_tx_timestamp(struct sk_buff *skb)
2746 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP &&
2747 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
2748 skb_tstamp_tx(skb, NULL);
2752 * skb_tx_timestamp() - Driver hook for transmit timestamping
2754 * Ethernet MAC Drivers should call this function in their hard_xmit()
2755 * function immediately before giving the sk_buff to the MAC hardware.
2757 * Specifically, one should make absolutely sure that this function is
2758 * called before TX completion of this packet can trigger. Otherwise
2759 * the packet could potentially already be freed.
2761 * @skb: A socket buffer.
2763 static inline void skb_tx_timestamp(struct sk_buff *skb)
2765 skb_clone_tx_timestamp(skb);
2766 sw_tx_timestamp(skb);
2770 * skb_complete_wifi_ack - deliver skb with wifi status
2772 * @skb: the original outgoing packet
2773 * @acked: ack status
2776 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
2778 __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
2779 __sum16 __skb_checksum_complete(struct sk_buff *skb);
2781 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
2783 return ((skb->ip_summed & CHECKSUM_UNNECESSARY) || skb->csum_valid);
2787 * skb_checksum_complete - Calculate checksum of an entire packet
2788 * @skb: packet to process
2790 * This function calculates the checksum over the entire packet plus
2791 * the value of skb->csum. The latter can be used to supply the
2792 * checksum of a pseudo header as used by TCP/UDP. It returns the
2795 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2796 * this function can be used to verify that checksum on received
2797 * packets. In that case the function should return zero if the
2798 * checksum is correct. In particular, this function will return zero
2799 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2800 * hardware has already verified the correctness of the checksum.
2802 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
2804 return skb_csum_unnecessary(skb) ?
2805 0 : __skb_checksum_complete(skb);
2808 static inline void __skb_decr_checksum_unnecessary(struct sk_buff *skb)
2810 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2811 if (skb->csum_level == 0)
2812 skb->ip_summed = CHECKSUM_NONE;
2818 static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb)
2820 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
2821 if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
2823 } else if (skb->ip_summed == CHECKSUM_NONE) {
2824 skb->ip_summed = CHECKSUM_UNNECESSARY;
2825 skb->csum_level = 0;
2829 static inline void __skb_mark_checksum_bad(struct sk_buff *skb)
2831 /* Mark current checksum as bad (typically called from GRO
2832 * path). In the case that ip_summed is CHECKSUM_NONE
2833 * this must be the first checksum encountered in the packet.
2834 * When ip_summed is CHECKSUM_UNNECESSARY, this is the first
2835 * checksum after the last one validated. For UDP, a zero
2836 * checksum can not be marked as bad.
2839 if (skb->ip_summed == CHECKSUM_NONE ||
2840 skb->ip_summed == CHECKSUM_UNNECESSARY)
2844 /* Check if we need to perform checksum complete validation.
2846 * Returns true if checksum complete is needed, false otherwise
2847 * (either checksum is unnecessary or zero checksum is allowed).
2849 static inline bool __skb_checksum_validate_needed(struct sk_buff *skb,
2853 if (skb_csum_unnecessary(skb) || (zero_okay && !check)) {
2854 skb->csum_valid = 1;
2855 __skb_decr_checksum_unnecessary(skb);
2862 /* For small packets <= CHECKSUM_BREAK peform checksum complete directly
2865 #define CHECKSUM_BREAK 76
2867 /* Validate (init) checksum based on checksum complete.
2870 * 0: checksum is validated or try to in skb_checksum_complete. In the latter
2871 * case the ip_summed will not be CHECKSUM_UNNECESSARY and the pseudo
2872 * checksum is stored in skb->csum for use in __skb_checksum_complete
2873 * non-zero: value of invalid checksum
2876 static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
2880 if (skb->ip_summed == CHECKSUM_COMPLETE) {
2881 if (!csum_fold(csum_add(psum, skb->csum))) {
2882 skb->csum_valid = 1;
2885 } else if (skb->csum_bad) {
2886 /* ip_summed == CHECKSUM_NONE in this case */
2892 if (complete || skb->len <= CHECKSUM_BREAK) {
2895 csum = __skb_checksum_complete(skb);
2896 skb->csum_valid = !csum;
2903 static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)
2908 /* Perform checksum validate (init). Note that this is a macro since we only
2909 * want to calculate the pseudo header which is an input function if necessary.
2910 * First we try to validate without any computation (checksum unnecessary) and
2911 * then calculate based on checksum complete calling the function to compute
2915 * 0: checksum is validated or try to in skb_checksum_complete
2916 * non-zero: value of invalid checksum
2918 #define __skb_checksum_validate(skb, proto, complete, \
2919 zero_okay, check, compute_pseudo) \
2921 __sum16 __ret = 0; \
2922 skb->csum_valid = 0; \
2923 if (__skb_checksum_validate_needed(skb, zero_okay, check)) \
2924 __ret = __skb_checksum_validate_complete(skb, \
2925 complete, compute_pseudo(skb, proto)); \
2929 #define skb_checksum_init(skb, proto, compute_pseudo) \
2930 __skb_checksum_validate(skb, proto, false, false, 0, compute_pseudo)
2932 #define skb_checksum_init_zero_check(skb, proto, check, compute_pseudo) \
2933 __skb_checksum_validate(skb, proto, false, true, check, compute_pseudo)
2935 #define skb_checksum_validate(skb, proto, compute_pseudo) \
2936 __skb_checksum_validate(skb, proto, true, false, 0, compute_pseudo)
2938 #define skb_checksum_validate_zero_check(skb, proto, check, \
2940 __skb_checksum_validate_(skb, proto, true, true, check, compute_pseudo)
2942 #define skb_checksum_simple_validate(skb) \
2943 __skb_checksum_validate(skb, 0, true, false, 0, null_compute_pseudo)
2945 static inline bool __skb_checksum_convert_check(struct sk_buff *skb)
2947 return (skb->ip_summed == CHECKSUM_NONE &&
2948 skb->csum_valid && !skb->csum_bad);
2951 static inline void __skb_checksum_convert(struct sk_buff *skb,
2952 __sum16 check, __wsum pseudo)
2954 skb->csum = ~pseudo;
2955 skb->ip_summed = CHECKSUM_COMPLETE;
2958 #define skb_checksum_try_convert(skb, proto, check, compute_pseudo) \
2960 if (__skb_checksum_convert_check(skb)) \
2961 __skb_checksum_convert(skb, check, \
2962 compute_pseudo(skb, proto)); \
2965 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2966 void nf_conntrack_destroy(struct nf_conntrack *nfct);
2967 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
2969 if (nfct && atomic_dec_and_test(&nfct->use))
2970 nf_conntrack_destroy(nfct);
2972 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
2975 atomic_inc(&nfct->use);
2978 #ifdef CONFIG_BRIDGE_NETFILTER
2979 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
2981 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
2984 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
2987 atomic_inc(&nf_bridge->use);
2989 #endif /* CONFIG_BRIDGE_NETFILTER */
2990 static inline void nf_reset(struct sk_buff *skb)
2992 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2993 nf_conntrack_put(skb->nfct);
2996 #ifdef CONFIG_BRIDGE_NETFILTER
2997 nf_bridge_put(skb->nf_bridge);
2998 skb->nf_bridge = NULL;
3002 static inline void nf_reset_trace(struct sk_buff *skb)
3004 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3009 /* Note: This doesn't put any conntrack and bridge info in dst. */
3010 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
3012 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3013 dst->nfct = src->nfct;
3014 nf_conntrack_get(src->nfct);
3015 dst->nfctinfo = src->nfctinfo;
3017 #ifdef CONFIG_BRIDGE_NETFILTER
3018 dst->nf_bridge = src->nf_bridge;
3019 nf_bridge_get(src->nf_bridge);
3021 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) || defined(CONFIG_NF_TABLES)
3022 dst->nf_trace = src->nf_trace;
3026 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
3028 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
3029 nf_conntrack_put(dst->nfct);
3031 #ifdef CONFIG_BRIDGE_NETFILTER
3032 nf_bridge_put(dst->nf_bridge);
3034 __nf_copy(dst, src);
3037 #ifdef CONFIG_NETWORK_SECMARK
3038 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
3040 to->secmark = from->secmark;
3043 static inline void skb_init_secmark(struct sk_buff *skb)
3048 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
3051 static inline void skb_init_secmark(struct sk_buff *skb)
3055 static inline bool skb_irq_freeable(const struct sk_buff *skb)
3057 return !skb->destructor &&
3058 #if IS_ENABLED(CONFIG_XFRM)
3061 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
3064 !skb->_skb_refdst &&
3065 !skb_has_frag_list(skb);
3068 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
3070 skb->queue_mapping = queue_mapping;
3073 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
3075 return skb->queue_mapping;
3078 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
3080 to->queue_mapping = from->queue_mapping;
3083 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
3085 skb->queue_mapping = rx_queue + 1;
3088 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
3090 return skb->queue_mapping - 1;
3093 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
3095 return skb->queue_mapping != 0;
3098 u16 __skb_tx_hash(const struct net_device *dev, struct sk_buff *skb,
3099 unsigned int num_tx_queues);
3101 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
3110 /* Keeps track of mac header offset relative to skb->head.
3111 * It is useful for TSO of Tunneling protocol. e.g. GRE.
3112 * For non-tunnel skb it points to skb_mac_header() and for
3113 * tunnel skb it points to outer mac header.
3114 * Keeps track of level of encapsulation of network headers.
3121 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb)
3123 static inline int skb_tnl_header_len(const struct sk_buff *inner_skb)
3125 return (skb_mac_header(inner_skb) - inner_skb->head) -
3126 SKB_GSO_CB(inner_skb)->mac_offset;
3129 static inline int gso_pskb_expand_head(struct sk_buff *skb, int extra)
3131 int new_headroom, headroom;
3134 headroom = skb_headroom(skb);
3135 ret = pskb_expand_head(skb, extra, 0, GFP_ATOMIC);
3139 new_headroom = skb_headroom(skb);
3140 SKB_GSO_CB(skb)->mac_offset += (new_headroom - headroom);
3144 /* Compute the checksum for a gso segment. First compute the checksum value
3145 * from the start of transport header to SKB_GSO_CB(skb)->csum_start, and
3146 * then add in skb->csum (checksum from csum_start to end of packet).
3147 * skb->csum and csum_start are then updated to reflect the checksum of the
3148 * resultant packet starting from the transport header-- the resultant checksum
3149 * is in the res argument (i.e. normally zero or ~ of checksum of a pseudo
3152 static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res)
3154 int plen = SKB_GSO_CB(skb)->csum_start - skb_headroom(skb) -
3155 skb_transport_offset(skb);
3158 csum = csum_fold(csum_partial(skb_transport_header(skb),
3161 SKB_GSO_CB(skb)->csum_start -= plen;
3166 static inline bool skb_is_gso(const struct sk_buff *skb)
3168 return skb_shinfo(skb)->gso_size;
3171 /* Note: Should be called only if skb_is_gso(skb) is true */
3172 static inline bool skb_is_gso_v6(const struct sk_buff *skb)
3174 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
3177 void __skb_warn_lro_forwarding(const struct sk_buff *skb);
3179 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
3181 /* LRO sets gso_size but not gso_type, whereas if GSO is really
3182 * wanted then gso_type will be set. */
3183 const struct skb_shared_info *shinfo = skb_shinfo(skb);
3185 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
3186 unlikely(shinfo->gso_type == 0)) {
3187 __skb_warn_lro_forwarding(skb);
3193 static inline void skb_forward_csum(struct sk_buff *skb)
3195 /* Unfortunately we don't support this one. Any brave souls? */
3196 if (skb->ip_summed == CHECKSUM_COMPLETE)
3197 skb->ip_summed = CHECKSUM_NONE;
3201 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
3202 * @skb: skb to check
3204 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
3205 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
3206 * use this helper, to document places where we make this assertion.
3208 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
3211 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
3215 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
3217 int skb_checksum_setup(struct sk_buff *skb, bool recalculate);
3219 u32 __skb_get_poff(const struct sk_buff *skb);
3222 * skb_head_is_locked - Determine if the skb->head is locked down
3223 * @skb: skb to check
3225 * The head on skbs build around a head frag can be removed if they are
3226 * not cloned. This function returns true if the skb head is locked down
3227 * due to either being allocated via kmalloc, or by being a clone with
3228 * multiple references to the head.
3230 static inline bool skb_head_is_locked(const struct sk_buff *skb)
3232 return !skb->head_frag || skb_cloned(skb);
3236 * skb_gso_network_seglen - Return length of individual segments of a gso packet
3240 * skb_gso_network_seglen is used to determine the real size of the
3241 * individual segments, including Layer3 (IP, IPv6) and L4 headers (TCP/UDP).
3243 * The MAC/L2 header is not accounted for.
3245 static inline unsigned int skb_gso_network_seglen(const struct sk_buff *skb)
3247 unsigned int hdr_len = skb_transport_header(skb) -
3248 skb_network_header(skb);
3249 return hdr_len + skb_gso_transport_seglen(skb);
3251 #endif /* __KERNEL__ */
3252 #endif /* _LINUX_SKBUFF_H */