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/cache.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/dmaengine.h>
31 #include <linux/hrtimer.h>
32 #include <linux/dma-mapping.h>
33 #include <linux/netdev_features.h>
35 /* Don't change this without changing skb_csum_unnecessary! */
36 #define CHECKSUM_NONE 0
37 #define CHECKSUM_UNNECESSARY 1
38 #define CHECKSUM_COMPLETE 2
39 #define CHECKSUM_PARTIAL 3
41 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
42 ~(SMP_CACHE_BYTES - 1))
43 #define SKB_WITH_OVERHEAD(X) \
44 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
45 #define SKB_MAX_ORDER(X, ORDER) \
46 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
47 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
48 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
50 /* return minimum truesize of one skb containing X bytes of data */
51 #define SKB_TRUESIZE(X) ((X) + \
52 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
53 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
55 /* A. Checksumming of received packets by device.
57 * NONE: device failed to checksum this packet.
58 * skb->csum is undefined.
60 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
61 * skb->csum is undefined.
62 * It is bad option, but, unfortunately, many of vendors do this.
63 * Apparently with secret goal to sell you new device, when you
64 * will add new protocol to your host. F.e. IPv6. 8)
66 * COMPLETE: the most generic way. Device supplied checksum of _all_
67 * the packet as seen by netif_rx in skb->csum.
68 * NOTE: Even if device supports only some protocols, but
69 * is able to produce some skb->csum, it MUST use COMPLETE,
72 * PARTIAL: identical to the case for output below. This may occur
73 * on a packet received directly from another Linux OS, e.g.,
74 * a virtualised Linux kernel on the same host. The packet can
75 * be treated in the same way as UNNECESSARY except that on
76 * output (i.e., forwarding) the checksum must be filled in
77 * by the OS or the hardware.
79 * B. Checksumming on output.
81 * NONE: skb is checksummed by protocol or csum is not required.
83 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
84 * from skb->csum_start to the end and to record the checksum
85 * at skb->csum_start + skb->csum_offset.
87 * Device must show its capabilities in dev->features, set
88 * at device setup time.
89 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
91 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
92 * TCP/UDP over IPv4. Sigh. Vendors like this
93 * way by an unknown reason. Though, see comment above
94 * about CHECKSUM_UNNECESSARY. 8)
95 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
97 * Any questions? No questions, good. --ANK
102 struct pipe_inode_info;
104 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
105 struct nf_conntrack {
110 #ifdef CONFIG_BRIDGE_NETFILTER
111 struct nf_bridge_info {
113 struct net_device *physindev;
114 struct net_device *physoutdev;
116 unsigned long data[32 / sizeof(unsigned long)];
120 struct sk_buff_head {
121 /* These two members must be first. */
122 struct sk_buff *next;
123 struct sk_buff *prev;
131 /* To allow 64K frame to be packed as single skb without frag_list we
132 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
133 * buffers which do not start on a page boundary.
135 * Since GRO uses frags we allocate at least 16 regardless of page
138 #if (65536/PAGE_SIZE + 1) < 16
139 #define MAX_SKB_FRAGS 16UL
141 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
144 typedef struct skb_frag_struct skb_frag_t;
146 struct skb_frag_struct {
150 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
159 static inline unsigned int skb_frag_size(const skb_frag_t *frag)
164 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
169 static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
174 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
179 #define HAVE_HW_TIME_STAMP
182 * struct skb_shared_hwtstamps - hardware time stamps
183 * @hwtstamp: hardware time stamp transformed into duration
184 * since arbitrary point in time
185 * @syststamp: hwtstamp transformed to system time base
187 * Software time stamps generated by ktime_get_real() are stored in
188 * skb->tstamp. The relation between the different kinds of time
189 * stamps is as follows:
191 * syststamp and tstamp can be compared against each other in
192 * arbitrary combinations. The accuracy of a
193 * syststamp/tstamp/"syststamp from other device" comparison is
194 * limited by the accuracy of the transformation into system time
195 * base. This depends on the device driver and its underlying
198 * hwtstamps can only be compared against other hwtstamps from
201 * This structure is attached to packets as part of the
202 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
204 struct skb_shared_hwtstamps {
209 /* Definitions for tx_flags in struct skb_shared_info */
211 /* generate hardware time stamp */
212 SKBTX_HW_TSTAMP = 1 << 0,
214 /* generate software time stamp */
215 SKBTX_SW_TSTAMP = 1 << 1,
217 /* device driver is going to provide hardware time stamp */
218 SKBTX_IN_PROGRESS = 1 << 2,
220 /* ensure the originating sk reference is available on driver level */
221 SKBTX_DRV_NEEDS_SK_REF = 1 << 3,
223 /* device driver supports TX zero-copy buffers */
224 SKBTX_DEV_ZEROCOPY = 1 << 4,
226 /* generate wifi status information (where possible) */
227 SKBTX_WIFI_STATUS = 1 << 5,
231 * The callback notifies userspace to release buffers when skb DMA is done in
232 * lower device, the skb last reference should be 0 when calling this.
233 * The desc is used to track userspace buffer index.
236 void (*callback)(void *);
241 /* This data is invariant across clones and lives at
242 * the end of the header data, ie. at skb->end.
244 struct skb_shared_info {
245 unsigned char nr_frags;
247 unsigned short gso_size;
248 /* Warning: this field is not always filled in (UFO)! */
249 unsigned short gso_segs;
250 unsigned short gso_type;
251 struct sk_buff *frag_list;
252 struct skb_shared_hwtstamps hwtstamps;
256 * Warning : all fields before dataref are cleared in __alloc_skb()
260 /* Intermediate layers must ensure that destructor_arg
261 * remains valid until skb destructor */
262 void * destructor_arg;
264 /* must be last field, see pskb_expand_head() */
265 skb_frag_t frags[MAX_SKB_FRAGS];
268 /* We divide dataref into two halves. The higher 16 bits hold references
269 * to the payload part of skb->data. The lower 16 bits hold references to
270 * the entire skb->data. A clone of a headerless skb holds the length of
271 * the header in skb->hdr_len.
273 * All users must obey the rule that the skb->data reference count must be
274 * greater than or equal to the payload reference count.
276 * Holding a reference to the payload part means that the user does not
277 * care about modifications to the header part of skb->data.
279 #define SKB_DATAREF_SHIFT 16
280 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
284 SKB_FCLONE_UNAVAILABLE,
290 SKB_GSO_TCPV4 = 1 << 0,
291 SKB_GSO_UDP = 1 << 1,
293 /* This indicates the skb is from an untrusted source. */
294 SKB_GSO_DODGY = 1 << 2,
296 /* This indicates the tcp segment has CWR set. */
297 SKB_GSO_TCP_ECN = 1 << 3,
299 SKB_GSO_TCPV6 = 1 << 4,
301 SKB_GSO_FCOE = 1 << 5,
304 #if BITS_PER_LONG > 32
305 #define NET_SKBUFF_DATA_USES_OFFSET 1
308 #ifdef NET_SKBUFF_DATA_USES_OFFSET
309 typedef unsigned int sk_buff_data_t;
311 typedef unsigned char *sk_buff_data_t;
314 #if defined(CONFIG_NF_DEFRAG_IPV4) || defined(CONFIG_NF_DEFRAG_IPV4_MODULE) || \
315 defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE)
316 #define NET_SKBUFF_NF_DEFRAG_NEEDED 1
320 * struct sk_buff - socket buffer
321 * @next: Next buffer in list
322 * @prev: Previous buffer in list
323 * @tstamp: Time we arrived
324 * @sk: Socket we are owned by
325 * @dev: Device we arrived on/are leaving by
326 * @cb: Control buffer. Free for use by every layer. Put private vars here
327 * @_skb_refdst: destination entry (with norefcount bit)
328 * @sp: the security path, used for xfrm
329 * @len: Length of actual data
330 * @data_len: Data length
331 * @mac_len: Length of link layer header
332 * @hdr_len: writable header length of cloned skb
333 * @csum: Checksum (must include start/offset pair)
334 * @csum_start: Offset from skb->head where checksumming should start
335 * @csum_offset: Offset from csum_start where checksum should be stored
336 * @priority: Packet queueing priority
337 * @local_df: allow local fragmentation
338 * @cloned: Head may be cloned (check refcnt to be sure)
339 * @ip_summed: Driver fed us an IP checksum
340 * @nohdr: Payload reference only, must not modify header
341 * @nfctinfo: Relationship of this skb to the connection
342 * @pkt_type: Packet class
343 * @fclone: skbuff clone status
344 * @ipvs_property: skbuff is owned by ipvs
345 * @peeked: this packet has been seen already, so stats have been
346 * done for it, don't do them again
347 * @nf_trace: netfilter packet trace flag
348 * @protocol: Packet protocol from driver
349 * @destructor: Destruct function
350 * @nfct: Associated connection, if any
351 * @nfct_reasm: netfilter conntrack re-assembly pointer
352 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
353 * @skb_iif: ifindex of device we arrived on
354 * @tc_index: Traffic control index
355 * @tc_verd: traffic control verdict
356 * @rxhash: the packet hash computed on receive
357 * @queue_mapping: Queue mapping for multiqueue devices
358 * @ndisc_nodetype: router type (from link layer)
359 * @ooo_okay: allow the mapping of a socket to a queue to be changed
360 * @l4_rxhash: indicate rxhash is a canonical 4-tuple hash over transport
362 * @wifi_acked_valid: wifi_acked was set
363 * @wifi_acked: whether frame was acked on wifi or not
364 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
365 * @dma_cookie: a cookie to one of several possible DMA operations
366 * done by skb DMA functions
367 * @secmark: security marking
368 * @mark: Generic packet mark
369 * @dropcount: total number of sk_receive_queue overflows
370 * @vlan_tci: vlan tag control information
371 * @transport_header: Transport layer header
372 * @network_header: Network layer header
373 * @mac_header: Link layer header
374 * @tail: Tail pointer
376 * @head: Head of buffer
377 * @data: Data head pointer
378 * @truesize: Buffer size
379 * @users: User count - see {datagram,tcp}.c
383 /* These two members must be first. */
384 struct sk_buff *next;
385 struct sk_buff *prev;
390 struct net_device *dev;
393 * This is the control buffer. It is free to use for every
394 * layer. Please put your private variables there. If you
395 * want to keep them across layers you have to do a skb_clone()
396 * first. This is owned by whoever has the skb queued ATM.
398 char cb[48] __aligned(8);
400 unsigned long _skb_refdst;
416 kmemcheck_bitfield_begin(flags1);
427 kmemcheck_bitfield_end(flags1);
430 void (*destructor)(struct sk_buff *skb);
431 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
432 struct nf_conntrack *nfct;
434 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
435 struct sk_buff *nfct_reasm;
437 #ifdef CONFIG_BRIDGE_NETFILTER
438 struct nf_bridge_info *nf_bridge;
447 #ifdef CONFIG_NET_SCHED
448 __u16 tc_index; /* traffic control index */
449 #ifdef CONFIG_NET_CLS_ACT
450 __u16 tc_verd; /* traffic control verdict */
455 kmemcheck_bitfield_begin(flags2);
456 #ifdef CONFIG_IPV6_NDISC_NODETYPE
457 __u8 ndisc_nodetype:2;
461 __u8 wifi_acked_valid:1;
464 /* 9/11 bit hole (depending on ndisc_nodetype presence) */
465 kmemcheck_bitfield_end(flags2);
467 #ifdef CONFIG_NET_DMA
468 dma_cookie_t dma_cookie;
470 #ifdef CONFIG_NETWORK_SECMARK
478 sk_buff_data_t transport_header;
479 sk_buff_data_t network_header;
480 sk_buff_data_t mac_header;
481 /* These elements must be at the end, see alloc_skb() for details. */
486 unsigned int truesize;
492 * Handling routines are only of interest to the kernel
494 #include <linux/slab.h>
496 #include <asm/system.h>
499 * skb might have a dst pointer attached, refcounted or not.
500 * _skb_refdst low order bit is set if refcount was _not_ taken
502 #define SKB_DST_NOREF 1UL
503 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
506 * skb_dst - returns skb dst_entry
509 * Returns skb dst_entry, regardless of reference taken or not.
511 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
513 /* If refdst was not refcounted, check we still are in a
514 * rcu_read_lock section
516 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
517 !rcu_read_lock_held() &&
518 !rcu_read_lock_bh_held());
519 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
523 * skb_dst_set - sets skb dst
527 * Sets skb dst, assuming a reference was taken on dst and should
528 * be released by skb_dst_drop()
530 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
532 skb->_skb_refdst = (unsigned long)dst;
535 extern void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst);
538 * skb_dst_is_noref - Test if skb dst isn't refcounted
541 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
543 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
546 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
548 return (struct rtable *)skb_dst(skb);
551 extern void kfree_skb(struct sk_buff *skb);
552 extern void consume_skb(struct sk_buff *skb);
553 extern void __kfree_skb(struct sk_buff *skb);
554 extern struct sk_buff *__alloc_skb(unsigned int size,
555 gfp_t priority, int fclone, int node);
556 extern struct sk_buff *build_skb(void *data);
557 static inline struct sk_buff *alloc_skb(unsigned int size,
560 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
563 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
566 return __alloc_skb(size, priority, 1, NUMA_NO_NODE);
569 extern void skb_recycle(struct sk_buff *skb);
570 extern bool skb_recycle_check(struct sk_buff *skb, int skb_size);
572 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
573 extern int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
574 extern struct sk_buff *skb_clone(struct sk_buff *skb,
576 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
578 extern struct sk_buff *__pskb_copy(struct sk_buff *skb,
579 int headroom, gfp_t gfp_mask);
581 extern int pskb_expand_head(struct sk_buff *skb,
582 int nhead, int ntail,
584 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
585 unsigned int headroom);
586 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
587 int newheadroom, int newtailroom,
589 extern int skb_to_sgvec(struct sk_buff *skb,
590 struct scatterlist *sg, int offset,
592 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
593 struct sk_buff **trailer);
594 extern int skb_pad(struct sk_buff *skb, int pad);
595 #define dev_kfree_skb(a) consume_skb(a)
597 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
598 int getfrag(void *from, char *to, int offset,
599 int len,int odd, struct sk_buff *skb),
600 void *from, int length);
602 struct skb_seq_state {
606 __u32 stepped_offset;
607 struct sk_buff *root_skb;
608 struct sk_buff *cur_skb;
612 extern void skb_prepare_seq_read(struct sk_buff *skb,
613 unsigned int from, unsigned int to,
614 struct skb_seq_state *st);
615 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
616 struct skb_seq_state *st);
617 extern void skb_abort_seq_read(struct skb_seq_state *st);
619 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
620 unsigned int to, struct ts_config *config,
621 struct ts_state *state);
623 extern void __skb_get_rxhash(struct sk_buff *skb);
624 static inline __u32 skb_get_rxhash(struct sk_buff *skb)
627 __skb_get_rxhash(skb);
632 #ifdef NET_SKBUFF_DATA_USES_OFFSET
633 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
635 return skb->head + skb->end;
638 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
645 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
647 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
649 return &skb_shinfo(skb)->hwtstamps;
653 * skb_queue_empty - check if a queue is empty
656 * Returns true if the queue is empty, false otherwise.
658 static inline int skb_queue_empty(const struct sk_buff_head *list)
660 return list->next == (struct sk_buff *)list;
664 * skb_queue_is_last - check if skb is the last entry in the queue
668 * Returns true if @skb is the last buffer on the list.
670 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
671 const struct sk_buff *skb)
673 return skb->next == (struct sk_buff *)list;
677 * skb_queue_is_first - check if skb is the first entry in the queue
681 * Returns true if @skb is the first buffer on the list.
683 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
684 const struct sk_buff *skb)
686 return skb->prev == (struct sk_buff *)list;
690 * skb_queue_next - return the next packet in the queue
692 * @skb: current buffer
694 * Return the next packet in @list after @skb. It is only valid to
695 * call this if skb_queue_is_last() evaluates to false.
697 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
698 const struct sk_buff *skb)
700 /* This BUG_ON may seem severe, but if we just return then we
701 * are going to dereference garbage.
703 BUG_ON(skb_queue_is_last(list, skb));
708 * skb_queue_prev - return the prev packet in the queue
710 * @skb: current buffer
712 * Return the prev packet in @list before @skb. It is only valid to
713 * call this if skb_queue_is_first() evaluates to false.
715 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
716 const struct sk_buff *skb)
718 /* This BUG_ON may seem severe, but if we just return then we
719 * are going to dereference garbage.
721 BUG_ON(skb_queue_is_first(list, skb));
726 * skb_get - reference buffer
727 * @skb: buffer to reference
729 * Makes another reference to a socket buffer and returns a pointer
732 static inline struct sk_buff *skb_get(struct sk_buff *skb)
734 atomic_inc(&skb->users);
739 * If users == 1, we are the only owner and are can avoid redundant
744 * skb_cloned - is the buffer a clone
745 * @skb: buffer to check
747 * Returns true if the buffer was generated with skb_clone() and is
748 * one of multiple shared copies of the buffer. Cloned buffers are
749 * shared data so must not be written to under normal circumstances.
751 static inline int skb_cloned(const struct sk_buff *skb)
753 return skb->cloned &&
754 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
758 * skb_header_cloned - is the header a clone
759 * @skb: buffer to check
761 * Returns true if modifying the header part of the buffer requires
762 * the data to be copied.
764 static inline int skb_header_cloned(const struct sk_buff *skb)
771 dataref = atomic_read(&skb_shinfo(skb)->dataref);
772 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
777 * skb_header_release - release reference to header
778 * @skb: buffer to operate on
780 * Drop a reference to the header part of the buffer. This is done
781 * by acquiring a payload reference. You must not read from the header
782 * part of skb->data after this.
784 static inline void skb_header_release(struct sk_buff *skb)
788 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
792 * skb_shared - is the buffer shared
793 * @skb: buffer to check
795 * Returns true if more than one person has a reference to this
798 static inline int skb_shared(const struct sk_buff *skb)
800 return atomic_read(&skb->users) != 1;
804 * skb_share_check - check if buffer is shared and if so clone it
805 * @skb: buffer to check
806 * @pri: priority for memory allocation
808 * If the buffer is shared the buffer is cloned and the old copy
809 * drops a reference. A new clone with a single reference is returned.
810 * If the buffer is not shared the original buffer is returned. When
811 * being called from interrupt status or with spinlocks held pri must
814 * NULL is returned on a memory allocation failure.
816 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
819 might_sleep_if(pri & __GFP_WAIT);
820 if (skb_shared(skb)) {
821 struct sk_buff *nskb = skb_clone(skb, pri);
829 * Copy shared buffers into a new sk_buff. We effectively do COW on
830 * packets to handle cases where we have a local reader and forward
831 * and a couple of other messy ones. The normal one is tcpdumping
832 * a packet thats being forwarded.
836 * skb_unshare - make a copy of a shared buffer
837 * @skb: buffer to check
838 * @pri: priority for memory allocation
840 * If the socket buffer is a clone then this function creates a new
841 * copy of the data, drops a reference count on the old copy and returns
842 * the new copy with the reference count at 1. If the buffer is not a clone
843 * the original buffer is returned. When called with a spinlock held or
844 * from interrupt state @pri must be %GFP_ATOMIC
846 * %NULL is returned on a memory allocation failure.
848 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
851 might_sleep_if(pri & __GFP_WAIT);
852 if (skb_cloned(skb)) {
853 struct sk_buff *nskb = skb_copy(skb, pri);
854 kfree_skb(skb); /* Free our shared copy */
861 * skb_peek - peek at the head of an &sk_buff_head
862 * @list_: list to peek at
864 * Peek an &sk_buff. Unlike most other operations you _MUST_
865 * be careful with this one. A peek leaves the buffer on the
866 * list and someone else may run off with it. You must hold
867 * the appropriate locks or have a private queue to do this.
869 * Returns %NULL for an empty list or a pointer to the head element.
870 * The reference count is not incremented and the reference is therefore
871 * volatile. Use with caution.
873 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
875 struct sk_buff *list = ((const struct sk_buff *)list_)->next;
876 if (list == (struct sk_buff *)list_)
882 * skb_peek_next - peek skb following the given one from a queue
883 * @skb: skb to start from
884 * @list_: list to peek at
886 * Returns %NULL when the end of the list is met or a pointer to the
887 * next element. The reference count is not incremented and the
888 * reference is therefore volatile. Use with caution.
890 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
891 const struct sk_buff_head *list_)
893 struct sk_buff *next = skb->next;
894 if (next == (struct sk_buff *)list_)
900 * skb_peek_tail - peek at the tail of an &sk_buff_head
901 * @list_: list to peek at
903 * Peek an &sk_buff. Unlike most other operations you _MUST_
904 * be careful with this one. A peek leaves the buffer on the
905 * list and someone else may run off with it. You must hold
906 * the appropriate locks or have a private queue to do this.
908 * Returns %NULL for an empty list or a pointer to the tail element.
909 * The reference count is not incremented and the reference is therefore
910 * volatile. Use with caution.
912 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
914 struct sk_buff *list = ((const struct sk_buff *)list_)->prev;
915 if (list == (struct sk_buff *)list_)
921 * skb_queue_len - get queue length
922 * @list_: list to measure
924 * Return the length of an &sk_buff queue.
926 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
932 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
933 * @list: queue to initialize
935 * This initializes only the list and queue length aspects of
936 * an sk_buff_head object. This allows to initialize the list
937 * aspects of an sk_buff_head without reinitializing things like
938 * the spinlock. It can also be used for on-stack sk_buff_head
939 * objects where the spinlock is known to not be used.
941 static inline void __skb_queue_head_init(struct sk_buff_head *list)
943 list->prev = list->next = (struct sk_buff *)list;
948 * This function creates a split out lock class for each invocation;
949 * this is needed for now since a whole lot of users of the skb-queue
950 * infrastructure in drivers have different locking usage (in hardirq)
951 * than the networking core (in softirq only). In the long run either the
952 * network layer or drivers should need annotation to consolidate the
953 * main types of usage into 3 classes.
955 static inline void skb_queue_head_init(struct sk_buff_head *list)
957 spin_lock_init(&list->lock);
958 __skb_queue_head_init(list);
961 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
962 struct lock_class_key *class)
964 skb_queue_head_init(list);
965 lockdep_set_class(&list->lock, class);
969 * Insert an sk_buff on a list.
971 * The "__skb_xxxx()" functions are the non-atomic ones that
972 * can only be called with interrupts disabled.
974 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
975 static inline void __skb_insert(struct sk_buff *newsk,
976 struct sk_buff *prev, struct sk_buff *next,
977 struct sk_buff_head *list)
981 next->prev = prev->next = newsk;
985 static inline void __skb_queue_splice(const struct sk_buff_head *list,
986 struct sk_buff *prev,
987 struct sk_buff *next)
989 struct sk_buff *first = list->next;
990 struct sk_buff *last = list->prev;
1000 * skb_queue_splice - join two skb lists, this is designed for stacks
1001 * @list: the new list to add
1002 * @head: the place to add it in the first list
1004 static inline void skb_queue_splice(const struct sk_buff_head *list,
1005 struct sk_buff_head *head)
1007 if (!skb_queue_empty(list)) {
1008 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1009 head->qlen += list->qlen;
1014 * skb_queue_splice - join two skb lists and reinitialise the emptied list
1015 * @list: the new list to add
1016 * @head: the place to add it in the first list
1018 * The list at @list is reinitialised
1020 static inline void skb_queue_splice_init(struct sk_buff_head *list,
1021 struct sk_buff_head *head)
1023 if (!skb_queue_empty(list)) {
1024 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1025 head->qlen += list->qlen;
1026 __skb_queue_head_init(list);
1031 * skb_queue_splice_tail - join two skb lists, each list being a queue
1032 * @list: the new list to add
1033 * @head: the place to add it in the first list
1035 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1036 struct sk_buff_head *head)
1038 if (!skb_queue_empty(list)) {
1039 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1040 head->qlen += list->qlen;
1045 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
1046 * @list: the new list to add
1047 * @head: the place to add it in the first list
1049 * Each of the lists is a queue.
1050 * The list at @list is reinitialised
1052 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
1053 struct sk_buff_head *head)
1055 if (!skb_queue_empty(list)) {
1056 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1057 head->qlen += list->qlen;
1058 __skb_queue_head_init(list);
1063 * __skb_queue_after - queue a buffer at the list head
1064 * @list: list to use
1065 * @prev: place after this buffer
1066 * @newsk: buffer to queue
1068 * Queue a buffer int the middle of a list. This function takes no locks
1069 * and you must therefore hold required locks before calling it.
1071 * A buffer cannot be placed on two lists at the same time.
1073 static inline void __skb_queue_after(struct sk_buff_head *list,
1074 struct sk_buff *prev,
1075 struct sk_buff *newsk)
1077 __skb_insert(newsk, prev, prev->next, list);
1080 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
1081 struct sk_buff_head *list);
1083 static inline void __skb_queue_before(struct sk_buff_head *list,
1084 struct sk_buff *next,
1085 struct sk_buff *newsk)
1087 __skb_insert(newsk, next->prev, next, list);
1091 * __skb_queue_head - queue a buffer at the list head
1092 * @list: list to use
1093 * @newsk: buffer to queue
1095 * Queue a buffer at the start of a list. This function takes no locks
1096 * and you must therefore hold required locks before calling it.
1098 * A buffer cannot be placed on two lists at the same time.
1100 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
1101 static inline void __skb_queue_head(struct sk_buff_head *list,
1102 struct sk_buff *newsk)
1104 __skb_queue_after(list, (struct sk_buff *)list, newsk);
1108 * __skb_queue_tail - queue a buffer at the list tail
1109 * @list: list to use
1110 * @newsk: buffer to queue
1112 * Queue a buffer at the end of a list. This function takes no locks
1113 * and you must therefore hold required locks before calling it.
1115 * A buffer cannot be placed on two lists at the same time.
1117 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
1118 static inline void __skb_queue_tail(struct sk_buff_head *list,
1119 struct sk_buff *newsk)
1121 __skb_queue_before(list, (struct sk_buff *)list, newsk);
1125 * remove sk_buff from list. _Must_ be called atomically, and with
1128 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
1129 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
1131 struct sk_buff *next, *prev;
1136 skb->next = skb->prev = NULL;
1142 * __skb_dequeue - remove from the head of the queue
1143 * @list: list to dequeue from
1145 * Remove the head of the list. This function does not take any locks
1146 * so must be used with appropriate locks held only. The head item is
1147 * returned or %NULL if the list is empty.
1149 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1150 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1152 struct sk_buff *skb = skb_peek(list);
1154 __skb_unlink(skb, list);
1159 * __skb_dequeue_tail - remove from the tail of the queue
1160 * @list: list to dequeue from
1162 * Remove the tail of the list. This function does not take any locks
1163 * so must be used with appropriate locks held only. The tail item is
1164 * returned or %NULL if the list is empty.
1166 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1167 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1169 struct sk_buff *skb = skb_peek_tail(list);
1171 __skb_unlink(skb, list);
1176 static inline int skb_is_nonlinear(const struct sk_buff *skb)
1178 return skb->data_len;
1181 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1183 return skb->len - skb->data_len;
1186 static inline int skb_pagelen(const struct sk_buff *skb)
1190 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1191 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
1192 return len + skb_headlen(skb);
1196 * __skb_fill_page_desc - initialise a paged fragment in an skb
1197 * @skb: buffer containing fragment to be initialised
1198 * @i: paged fragment index to initialise
1199 * @page: the page to use for this fragment
1200 * @off: the offset to the data with @page
1201 * @size: the length of the data
1203 * Initialises the @i'th fragment of @skb to point to &size bytes at
1204 * offset @off within @page.
1206 * Does not take any additional reference on the fragment.
1208 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
1209 struct page *page, int off, int size)
1211 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1213 frag->page.p = page;
1214 frag->page_offset = off;
1215 skb_frag_size_set(frag, size);
1219 * skb_fill_page_desc - initialise a paged fragment in an skb
1220 * @skb: buffer containing fragment to be initialised
1221 * @i: paged fragment index to initialise
1222 * @page: the page to use for this fragment
1223 * @off: the offset to the data with @page
1224 * @size: the length of the data
1226 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1227 * @skb to point to &size bytes at offset @off within @page. In
1228 * addition updates @skb such that @i is the last fragment.
1230 * Does not take any additional reference on the fragment.
1232 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1233 struct page *page, int off, int size)
1235 __skb_fill_page_desc(skb, i, page, off, size);
1236 skb_shinfo(skb)->nr_frags = i + 1;
1239 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1242 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1243 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1244 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1246 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1247 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1249 return skb->head + skb->tail;
1252 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1254 skb->tail = skb->data - skb->head;
1257 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1259 skb_reset_tail_pointer(skb);
1260 skb->tail += offset;
1262 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1263 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1268 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1270 skb->tail = skb->data;
1273 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1275 skb->tail = skb->data + offset;
1278 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1281 * Add data to an sk_buff
1283 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1284 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1286 unsigned char *tmp = skb_tail_pointer(skb);
1287 SKB_LINEAR_ASSERT(skb);
1293 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1294 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1301 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1302 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1305 BUG_ON(skb->len < skb->data_len);
1306 return skb->data += len;
1309 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len)
1311 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
1314 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1316 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1318 if (len > skb_headlen(skb) &&
1319 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1322 return skb->data += len;
1325 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1327 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1330 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1332 if (likely(len <= skb_headlen(skb)))
1334 if (unlikely(len > skb->len))
1336 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1340 * skb_headroom - bytes at buffer head
1341 * @skb: buffer to check
1343 * Return the number of bytes of free space at the head of an &sk_buff.
1345 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1347 return skb->data - skb->head;
1351 * skb_tailroom - bytes at buffer end
1352 * @skb: buffer to check
1354 * Return the number of bytes of free space at the tail of an sk_buff
1356 static inline int skb_tailroom(const struct sk_buff *skb)
1358 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1362 * skb_reserve - adjust headroom
1363 * @skb: buffer to alter
1364 * @len: bytes to move
1366 * Increase the headroom of an empty &sk_buff by reducing the tail
1367 * room. This is only allowed for an empty buffer.
1369 static inline void skb_reserve(struct sk_buff *skb, int len)
1375 static inline void skb_reset_mac_len(struct sk_buff *skb)
1377 skb->mac_len = skb->network_header - skb->mac_header;
1380 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1381 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1383 return skb->head + skb->transport_header;
1386 static inline void skb_reset_transport_header(struct sk_buff *skb)
1388 skb->transport_header = skb->data - skb->head;
1391 static inline void skb_set_transport_header(struct sk_buff *skb,
1394 skb_reset_transport_header(skb);
1395 skb->transport_header += offset;
1398 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1400 return skb->head + skb->network_header;
1403 static inline void skb_reset_network_header(struct sk_buff *skb)
1405 skb->network_header = skb->data - skb->head;
1408 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1410 skb_reset_network_header(skb);
1411 skb->network_header += offset;
1414 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1416 return skb->head + skb->mac_header;
1419 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1421 return skb->mac_header != ~0U;
1424 static inline void skb_reset_mac_header(struct sk_buff *skb)
1426 skb->mac_header = skb->data - skb->head;
1429 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1431 skb_reset_mac_header(skb);
1432 skb->mac_header += offset;
1435 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1437 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1439 return skb->transport_header;
1442 static inline void skb_reset_transport_header(struct sk_buff *skb)
1444 skb->transport_header = skb->data;
1447 static inline void skb_set_transport_header(struct sk_buff *skb,
1450 skb->transport_header = skb->data + offset;
1453 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1455 return skb->network_header;
1458 static inline void skb_reset_network_header(struct sk_buff *skb)
1460 skb->network_header = skb->data;
1463 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1465 skb->network_header = skb->data + offset;
1468 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1470 return skb->mac_header;
1473 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1475 return skb->mac_header != NULL;
1478 static inline void skb_reset_mac_header(struct sk_buff *skb)
1480 skb->mac_header = skb->data;
1483 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1485 skb->mac_header = skb->data + offset;
1487 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1489 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
1491 return skb->csum_start - skb_headroom(skb);
1494 static inline int skb_transport_offset(const struct sk_buff *skb)
1496 return skb_transport_header(skb) - skb->data;
1499 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1501 return skb->transport_header - skb->network_header;
1504 static inline int skb_network_offset(const struct sk_buff *skb)
1506 return skb_network_header(skb) - skb->data;
1509 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
1511 return pskb_may_pull(skb, skb_network_offset(skb) + len);
1515 * CPUs often take a performance hit when accessing unaligned memory
1516 * locations. The actual performance hit varies, it can be small if the
1517 * hardware handles it or large if we have to take an exception and fix it
1520 * Since an ethernet header is 14 bytes network drivers often end up with
1521 * the IP header at an unaligned offset. The IP header can be aligned by
1522 * shifting the start of the packet by 2 bytes. Drivers should do this
1525 * skb_reserve(skb, NET_IP_ALIGN);
1527 * The downside to this alignment of the IP header is that the DMA is now
1528 * unaligned. On some architectures the cost of an unaligned DMA is high
1529 * and this cost outweighs the gains made by aligning the IP header.
1531 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1534 #ifndef NET_IP_ALIGN
1535 #define NET_IP_ALIGN 2
1539 * The networking layer reserves some headroom in skb data (via
1540 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1541 * the header has to grow. In the default case, if the header has to grow
1542 * 32 bytes or less we avoid the reallocation.
1544 * Unfortunately this headroom changes the DMA alignment of the resulting
1545 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1546 * on some architectures. An architecture can override this value,
1547 * perhaps setting it to a cacheline in size (since that will maintain
1548 * cacheline alignment of the DMA). It must be a power of 2.
1550 * Various parts of the networking layer expect at least 32 bytes of
1551 * headroom, you should not reduce this.
1553 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1554 * to reduce average number of cache lines per packet.
1555 * get_rps_cpus() for example only access one 64 bytes aligned block :
1556 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1559 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1562 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1564 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1566 if (unlikely(skb_is_nonlinear(skb))) {
1571 skb_set_tail_pointer(skb, len);
1574 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1576 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1579 return ___pskb_trim(skb, len);
1580 __skb_trim(skb, len);
1584 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1586 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1590 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1591 * @skb: buffer to alter
1594 * This is identical to pskb_trim except that the caller knows that
1595 * the skb is not cloned so we should never get an error due to out-
1598 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1600 int err = pskb_trim(skb, len);
1605 * skb_orphan - orphan a buffer
1606 * @skb: buffer to orphan
1608 * If a buffer currently has an owner then we call the owner's
1609 * destructor function and make the @skb unowned. The buffer continues
1610 * to exist but is no longer charged to its former owner.
1612 static inline void skb_orphan(struct sk_buff *skb)
1614 if (skb->destructor)
1615 skb->destructor(skb);
1616 skb->destructor = NULL;
1621 * __skb_queue_purge - empty a list
1622 * @list: list to empty
1624 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1625 * the list and one reference dropped. This function does not take the
1626 * list lock and the caller must hold the relevant locks to use it.
1628 extern void skb_queue_purge(struct sk_buff_head *list);
1629 static inline void __skb_queue_purge(struct sk_buff_head *list)
1631 struct sk_buff *skb;
1632 while ((skb = __skb_dequeue(list)) != NULL)
1637 * __dev_alloc_skb - allocate an skbuff for receiving
1638 * @length: length to allocate
1639 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1641 * Allocate a new &sk_buff and assign it a usage count of one. The
1642 * buffer has unspecified headroom built in. Users should allocate
1643 * the headroom they think they need without accounting for the
1644 * built in space. The built in space is used for optimisations.
1646 * %NULL is returned if there is no free memory.
1648 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1651 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1653 skb_reserve(skb, NET_SKB_PAD);
1657 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1659 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1660 unsigned int length, gfp_t gfp_mask);
1663 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1664 * @dev: network device to receive on
1665 * @length: length to allocate
1667 * Allocate a new &sk_buff and assign it a usage count of one. The
1668 * buffer has unspecified headroom built in. Users should allocate
1669 * the headroom they think they need without accounting for the
1670 * built in space. The built in space is used for optimisations.
1672 * %NULL is returned if there is no free memory. Although this function
1673 * allocates memory it can be called from an interrupt.
1675 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1676 unsigned int length)
1678 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1681 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
1682 unsigned int length, gfp_t gfp)
1684 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
1686 if (NET_IP_ALIGN && skb)
1687 skb_reserve(skb, NET_IP_ALIGN);
1691 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
1692 unsigned int length)
1694 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
1698 * skb_frag_page - retrieve the page refered to by a paged fragment
1699 * @frag: the paged fragment
1701 * Returns the &struct page associated with @frag.
1703 static inline struct page *skb_frag_page(const skb_frag_t *frag)
1705 return frag->page.p;
1709 * __skb_frag_ref - take an addition reference on a paged fragment.
1710 * @frag: the paged fragment
1712 * Takes an additional reference on the paged fragment @frag.
1714 static inline void __skb_frag_ref(skb_frag_t *frag)
1716 get_page(skb_frag_page(frag));
1720 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
1722 * @f: the fragment offset.
1724 * Takes an additional reference on the @f'th paged fragment of @skb.
1726 static inline void skb_frag_ref(struct sk_buff *skb, int f)
1728 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
1732 * __skb_frag_unref - release a reference on a paged fragment.
1733 * @frag: the paged fragment
1735 * Releases a reference on the paged fragment @frag.
1737 static inline void __skb_frag_unref(skb_frag_t *frag)
1739 put_page(skb_frag_page(frag));
1743 * skb_frag_unref - release a reference on a paged fragment of an skb.
1745 * @f: the fragment offset
1747 * Releases a reference on the @f'th paged fragment of @skb.
1749 static inline void skb_frag_unref(struct sk_buff *skb, int f)
1751 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
1755 * skb_frag_address - gets the address of the data contained in a paged fragment
1756 * @frag: the paged fragment buffer
1758 * Returns the address of the data within @frag. The page must already
1761 static inline void *skb_frag_address(const skb_frag_t *frag)
1763 return page_address(skb_frag_page(frag)) + frag->page_offset;
1767 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
1768 * @frag: the paged fragment buffer
1770 * Returns the address of the data within @frag. Checks that the page
1771 * is mapped and returns %NULL otherwise.
1773 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
1775 void *ptr = page_address(skb_frag_page(frag));
1779 return ptr + frag->page_offset;
1783 * __skb_frag_set_page - sets the page contained in a paged fragment
1784 * @frag: the paged fragment
1785 * @page: the page to set
1787 * Sets the fragment @frag to contain @page.
1789 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
1791 frag->page.p = page;
1795 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
1797 * @f: the fragment offset
1798 * @page: the page to set
1800 * Sets the @f'th fragment of @skb to contain @page.
1802 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
1805 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
1809 * skb_frag_dma_map - maps a paged fragment via the DMA API
1810 * @dev: the device to map the fragment to
1811 * @frag: the paged fragment to map
1812 * @offset: the offset within the fragment (starting at the
1813 * fragment's own offset)
1814 * @size: the number of bytes to map
1815 * @dir: the direction of the mapping (%PCI_DMA_*)
1817 * Maps the page associated with @frag to @device.
1819 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
1820 const skb_frag_t *frag,
1821 size_t offset, size_t size,
1822 enum dma_data_direction dir)
1824 return dma_map_page(dev, skb_frag_page(frag),
1825 frag->page_offset + offset, size, dir);
1828 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
1831 return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
1835 * skb_clone_writable - is the header of a clone writable
1836 * @skb: buffer to check
1837 * @len: length up to which to write
1839 * Returns true if modifying the header part of the cloned buffer
1840 * does not requires the data to be copied.
1842 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
1844 return !skb_header_cloned(skb) &&
1845 skb_headroom(skb) + len <= skb->hdr_len;
1848 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1853 if (headroom < NET_SKB_PAD)
1854 headroom = NET_SKB_PAD;
1855 if (headroom > skb_headroom(skb))
1856 delta = headroom - skb_headroom(skb);
1858 if (delta || cloned)
1859 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1865 * skb_cow - copy header of skb when it is required
1866 * @skb: buffer to cow
1867 * @headroom: needed headroom
1869 * If the skb passed lacks sufficient headroom or its data part
1870 * is shared, data is reallocated. If reallocation fails, an error
1871 * is returned and original skb is not changed.
1873 * The result is skb with writable area skb->head...skb->tail
1874 * and at least @headroom of space at head.
1876 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1878 return __skb_cow(skb, headroom, skb_cloned(skb));
1882 * skb_cow_head - skb_cow but only making the head writable
1883 * @skb: buffer to cow
1884 * @headroom: needed headroom
1886 * This function is identical to skb_cow except that we replace the
1887 * skb_cloned check by skb_header_cloned. It should be used when
1888 * you only need to push on some header and do not need to modify
1891 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1893 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1897 * skb_padto - pad an skbuff up to a minimal size
1898 * @skb: buffer to pad
1899 * @len: minimal length
1901 * Pads up a buffer to ensure the trailing bytes exist and are
1902 * blanked. If the buffer already contains sufficient data it
1903 * is untouched. Otherwise it is extended. Returns zero on
1904 * success. The skb is freed on error.
1907 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1909 unsigned int size = skb->len;
1910 if (likely(size >= len))
1912 return skb_pad(skb, len - size);
1915 static inline int skb_add_data(struct sk_buff *skb,
1916 char __user *from, int copy)
1918 const int off = skb->len;
1920 if (skb->ip_summed == CHECKSUM_NONE) {
1922 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1925 skb->csum = csum_block_add(skb->csum, csum, off);
1928 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1931 __skb_trim(skb, off);
1935 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
1936 const struct page *page, int off)
1939 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1941 return page == skb_frag_page(frag) &&
1942 off == frag->page_offset + skb_frag_size(frag);
1947 static inline int __skb_linearize(struct sk_buff *skb)
1949 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1953 * skb_linearize - convert paged skb to linear one
1954 * @skb: buffer to linarize
1956 * If there is no free memory -ENOMEM is returned, otherwise zero
1957 * is returned and the old skb data released.
1959 static inline int skb_linearize(struct sk_buff *skb)
1961 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1965 * skb_linearize_cow - make sure skb is linear and writable
1966 * @skb: buffer to process
1968 * If there is no free memory -ENOMEM is returned, otherwise zero
1969 * is returned and the old skb data released.
1971 static inline int skb_linearize_cow(struct sk_buff *skb)
1973 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
1974 __skb_linearize(skb) : 0;
1978 * skb_postpull_rcsum - update checksum for received skb after pull
1979 * @skb: buffer to update
1980 * @start: start of data before pull
1981 * @len: length of data pulled
1983 * After doing a pull on a received packet, you need to call this to
1984 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1985 * CHECKSUM_NONE so that it can be recomputed from scratch.
1988 static inline void skb_postpull_rcsum(struct sk_buff *skb,
1989 const void *start, unsigned int len)
1991 if (skb->ip_summed == CHECKSUM_COMPLETE)
1992 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
1995 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
1998 * pskb_trim_rcsum - trim received skb and update checksum
1999 * @skb: buffer to trim
2002 * This is exactly the same as pskb_trim except that it ensures the
2003 * checksum of received packets are still valid after the operation.
2006 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
2008 if (likely(len >= skb->len))
2010 if (skb->ip_summed == CHECKSUM_COMPLETE)
2011 skb->ip_summed = CHECKSUM_NONE;
2012 return __pskb_trim(skb, len);
2015 #define skb_queue_walk(queue, skb) \
2016 for (skb = (queue)->next; \
2017 skb != (struct sk_buff *)(queue); \
2020 #define skb_queue_walk_safe(queue, skb, tmp) \
2021 for (skb = (queue)->next, tmp = skb->next; \
2022 skb != (struct sk_buff *)(queue); \
2023 skb = tmp, tmp = skb->next)
2025 #define skb_queue_walk_from(queue, skb) \
2026 for (; skb != (struct sk_buff *)(queue); \
2029 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2030 for (tmp = skb->next; \
2031 skb != (struct sk_buff *)(queue); \
2032 skb = tmp, tmp = skb->next)
2034 #define skb_queue_reverse_walk(queue, skb) \
2035 for (skb = (queue)->prev; \
2036 skb != (struct sk_buff *)(queue); \
2039 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2040 for (skb = (queue)->prev, tmp = skb->prev; \
2041 skb != (struct sk_buff *)(queue); \
2042 skb = tmp, tmp = skb->prev)
2044 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2045 for (tmp = skb->prev; \
2046 skb != (struct sk_buff *)(queue); \
2047 skb = tmp, tmp = skb->prev)
2049 static inline bool skb_has_frag_list(const struct sk_buff *skb)
2051 return skb_shinfo(skb)->frag_list != NULL;
2054 static inline void skb_frag_list_init(struct sk_buff *skb)
2056 skb_shinfo(skb)->frag_list = NULL;
2059 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
2061 frag->next = skb_shinfo(skb)->frag_list;
2062 skb_shinfo(skb)->frag_list = frag;
2065 #define skb_walk_frags(skb, iter) \
2066 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2068 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
2069 int *peeked, int *off, int *err);
2070 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
2071 int noblock, int *err);
2072 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
2073 struct poll_table_struct *wait);
2074 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
2075 int offset, struct iovec *to,
2077 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
2080 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
2082 const struct iovec *from,
2085 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from,
2087 const struct iovec *to,
2090 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
2091 extern void skb_free_datagram_locked(struct sock *sk,
2092 struct sk_buff *skb);
2093 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
2094 unsigned int flags);
2095 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
2096 int len, __wsum csum);
2097 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
2099 extern int skb_store_bits(struct sk_buff *skb, int offset,
2100 const void *from, int len);
2101 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
2102 int offset, u8 *to, int len,
2104 extern int skb_splice_bits(struct sk_buff *skb,
2105 unsigned int offset,
2106 struct pipe_inode_info *pipe,
2108 unsigned int flags);
2109 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
2110 extern void skb_split(struct sk_buff *skb,
2111 struct sk_buff *skb1, const u32 len);
2112 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
2115 extern struct sk_buff *skb_segment(struct sk_buff *skb,
2116 netdev_features_t features);
2118 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
2119 int len, void *buffer)
2121 int hlen = skb_headlen(skb);
2123 if (hlen - offset >= len)
2124 return skb->data + offset;
2126 if (skb_copy_bits(skb, offset, buffer, len) < 0)
2132 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
2134 const unsigned int len)
2136 memcpy(to, skb->data, len);
2139 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
2140 const int offset, void *to,
2141 const unsigned int len)
2143 memcpy(to, skb->data + offset, len);
2146 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
2148 const unsigned int len)
2150 memcpy(skb->data, from, len);
2153 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
2156 const unsigned int len)
2158 memcpy(skb->data + offset, from, len);
2161 extern void skb_init(void);
2163 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
2169 * skb_get_timestamp - get timestamp from a skb
2170 * @skb: skb to get stamp from
2171 * @stamp: pointer to struct timeval to store stamp in
2173 * Timestamps are stored in the skb as offsets to a base timestamp.
2174 * This function converts the offset back to a struct timeval and stores
2177 static inline void skb_get_timestamp(const struct sk_buff *skb,
2178 struct timeval *stamp)
2180 *stamp = ktime_to_timeval(skb->tstamp);
2183 static inline void skb_get_timestampns(const struct sk_buff *skb,
2184 struct timespec *stamp)
2186 *stamp = ktime_to_timespec(skb->tstamp);
2189 static inline void __net_timestamp(struct sk_buff *skb)
2191 skb->tstamp = ktime_get_real();
2194 static inline ktime_t net_timedelta(ktime_t t)
2196 return ktime_sub(ktime_get_real(), t);
2199 static inline ktime_t net_invalid_timestamp(void)
2201 return ktime_set(0, 0);
2204 extern void skb_timestamping_init(void);
2206 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2208 extern void skb_clone_tx_timestamp(struct sk_buff *skb);
2209 extern bool skb_defer_rx_timestamp(struct sk_buff *skb);
2211 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2213 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
2217 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
2222 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2225 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2227 * PHY drivers may accept clones of transmitted packets for
2228 * timestamping via their phy_driver.txtstamp method. These drivers
2229 * must call this function to return the skb back to the stack, with
2230 * or without a timestamp.
2232 * @skb: clone of the the original outgoing packet
2233 * @hwtstamps: hardware time stamps, may be NULL if not available
2236 void skb_complete_tx_timestamp(struct sk_buff *skb,
2237 struct skb_shared_hwtstamps *hwtstamps);
2240 * skb_tstamp_tx - queue clone of skb with send time stamps
2241 * @orig_skb: the original outgoing packet
2242 * @hwtstamps: hardware time stamps, may be NULL if not available
2244 * If the skb has a socket associated, then this function clones the
2245 * skb (thus sharing the actual data and optional structures), stores
2246 * the optional hardware time stamping information (if non NULL) or
2247 * generates a software time stamp (otherwise), then queues the clone
2248 * to the error queue of the socket. Errors are silently ignored.
2250 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
2251 struct skb_shared_hwtstamps *hwtstamps);
2253 static inline void sw_tx_timestamp(struct sk_buff *skb)
2255 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP &&
2256 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
2257 skb_tstamp_tx(skb, NULL);
2261 * skb_tx_timestamp() - Driver hook for transmit timestamping
2263 * Ethernet MAC Drivers should call this function in their hard_xmit()
2264 * function immediately before giving the sk_buff to the MAC hardware.
2266 * @skb: A socket buffer.
2268 static inline void skb_tx_timestamp(struct sk_buff *skb)
2270 skb_clone_tx_timestamp(skb);
2271 sw_tx_timestamp(skb);
2275 * skb_complete_wifi_ack - deliver skb with wifi status
2277 * @skb: the original outgoing packet
2278 * @acked: ack status
2281 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
2283 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
2284 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
2286 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
2288 return skb->ip_summed & CHECKSUM_UNNECESSARY;
2292 * skb_checksum_complete - Calculate checksum of an entire packet
2293 * @skb: packet to process
2295 * This function calculates the checksum over the entire packet plus
2296 * the value of skb->csum. The latter can be used to supply the
2297 * checksum of a pseudo header as used by TCP/UDP. It returns the
2300 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2301 * this function can be used to verify that checksum on received
2302 * packets. In that case the function should return zero if the
2303 * checksum is correct. In particular, this function will return zero
2304 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2305 * hardware has already verified the correctness of the checksum.
2307 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
2309 return skb_csum_unnecessary(skb) ?
2310 0 : __skb_checksum_complete(skb);
2313 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2314 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
2315 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
2317 if (nfct && atomic_dec_and_test(&nfct->use))
2318 nf_conntrack_destroy(nfct);
2320 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
2323 atomic_inc(&nfct->use);
2326 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2327 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
2330 atomic_inc(&skb->users);
2332 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
2338 #ifdef CONFIG_BRIDGE_NETFILTER
2339 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
2341 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
2344 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
2347 atomic_inc(&nf_bridge->use);
2349 #endif /* CONFIG_BRIDGE_NETFILTER */
2350 static inline void nf_reset(struct sk_buff *skb)
2352 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2353 nf_conntrack_put(skb->nfct);
2356 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2357 nf_conntrack_put_reasm(skb->nfct_reasm);
2358 skb->nfct_reasm = NULL;
2360 #ifdef CONFIG_BRIDGE_NETFILTER
2361 nf_bridge_put(skb->nf_bridge);
2362 skb->nf_bridge = NULL;
2366 /* Note: This doesn't put any conntrack and bridge info in dst. */
2367 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2369 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2370 dst->nfct = src->nfct;
2371 nf_conntrack_get(src->nfct);
2372 dst->nfctinfo = src->nfctinfo;
2374 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2375 dst->nfct_reasm = src->nfct_reasm;
2376 nf_conntrack_get_reasm(src->nfct_reasm);
2378 #ifdef CONFIG_BRIDGE_NETFILTER
2379 dst->nf_bridge = src->nf_bridge;
2380 nf_bridge_get(src->nf_bridge);
2384 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2386 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2387 nf_conntrack_put(dst->nfct);
2389 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2390 nf_conntrack_put_reasm(dst->nfct_reasm);
2392 #ifdef CONFIG_BRIDGE_NETFILTER
2393 nf_bridge_put(dst->nf_bridge);
2395 __nf_copy(dst, src);
2398 #ifdef CONFIG_NETWORK_SECMARK
2399 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2401 to->secmark = from->secmark;
2404 static inline void skb_init_secmark(struct sk_buff *skb)
2409 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2412 static inline void skb_init_secmark(struct sk_buff *skb)
2416 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
2418 skb->queue_mapping = queue_mapping;
2421 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
2423 return skb->queue_mapping;
2426 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
2428 to->queue_mapping = from->queue_mapping;
2431 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
2433 skb->queue_mapping = rx_queue + 1;
2436 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2438 return skb->queue_mapping - 1;
2441 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2443 return skb->queue_mapping != 0;
2446 extern u16 __skb_tx_hash(const struct net_device *dev,
2447 const struct sk_buff *skb,
2448 unsigned int num_tx_queues);
2451 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2456 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2462 static inline int skb_is_gso(const struct sk_buff *skb)
2464 return skb_shinfo(skb)->gso_size;
2467 static inline int skb_is_gso_v6(const struct sk_buff *skb)
2469 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2472 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2474 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2476 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2477 * wanted then gso_type will be set. */
2478 const struct skb_shared_info *shinfo = skb_shinfo(skb);
2480 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
2481 unlikely(shinfo->gso_type == 0)) {
2482 __skb_warn_lro_forwarding(skb);
2488 static inline void skb_forward_csum(struct sk_buff *skb)
2490 /* Unfortunately we don't support this one. Any brave souls? */
2491 if (skb->ip_summed == CHECKSUM_COMPLETE)
2492 skb->ip_summed = CHECKSUM_NONE;
2496 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
2497 * @skb: skb to check
2499 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
2500 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
2501 * use this helper, to document places where we make this assertion.
2503 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
2506 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
2510 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2512 static inline bool skb_is_recycleable(const struct sk_buff *skb, int skb_size)
2514 if (irqs_disabled())
2517 if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY)
2520 if (skb_is_nonlinear(skb) || skb->fclone != SKB_FCLONE_UNAVAILABLE)
2523 skb_size = SKB_DATA_ALIGN(skb_size + NET_SKB_PAD);
2524 if (skb_end_pointer(skb) - skb->head < skb_size)
2527 if (skb_shared(skb) || skb_cloned(skb))
2532 #endif /* __KERNEL__ */
2533 #endif /* _LINUX_SKBUFF_H */