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>
34 /* Don't change this without changing skb_csum_unnecessary! */
35 #define CHECKSUM_NONE 0
36 #define CHECKSUM_UNNECESSARY 1
37 #define CHECKSUM_COMPLETE 2
38 #define CHECKSUM_PARTIAL 3
40 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
41 ~(SMP_CACHE_BYTES - 1))
42 #define SKB_WITH_OVERHEAD(X) \
43 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
44 #define SKB_MAX_ORDER(X, ORDER) \
45 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
46 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
47 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
49 /* return minimum truesize of one skb containing X bytes of data */
50 #define SKB_TRUESIZE(X) ((X) + \
51 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
52 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
54 /* A. Checksumming of received packets by device.
56 * NONE: device failed to checksum this packet.
57 * skb->csum is undefined.
59 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
60 * skb->csum is undefined.
61 * It is bad option, but, unfortunately, many of vendors do this.
62 * Apparently with secret goal to sell you new device, when you
63 * will add new protocol to your host. F.e. IPv6. 8)
65 * COMPLETE: the most generic way. Device supplied checksum of _all_
66 * the packet as seen by netif_rx in skb->csum.
67 * NOTE: Even if device supports only some protocols, but
68 * is able to produce some skb->csum, it MUST use COMPLETE,
71 * PARTIAL: identical to the case for output below. This may occur
72 * on a packet received directly from another Linux OS, e.g.,
73 * a virtualised Linux kernel on the same host. The packet can
74 * be treated in the same way as UNNECESSARY except that on
75 * output (i.e., forwarding) the checksum must be filled in
76 * by the OS or the hardware.
78 * B. Checksumming on output.
80 * NONE: skb is checksummed by protocol or csum is not required.
82 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
83 * from skb->csum_start to the end and to record the checksum
84 * at skb->csum_start + skb->csum_offset.
86 * Device must show its capabilities in dev->features, set
87 * at device setup time.
88 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
90 * NETIF_F_NO_CSUM - loopback or reliable single hop media.
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. Since
132 * GRO uses frags we allocate at least 16 regardless of page size.
134 #if (65536/PAGE_SIZE + 2) < 16
135 #define MAX_SKB_FRAGS 16UL
137 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
140 typedef struct skb_frag_struct skb_frag_t;
142 struct skb_frag_struct {
146 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
155 static inline unsigned int skb_frag_size(const skb_frag_t *frag)
160 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
165 static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
170 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
175 #define HAVE_HW_TIME_STAMP
178 * struct skb_shared_hwtstamps - hardware time stamps
179 * @hwtstamp: hardware time stamp transformed into duration
180 * since arbitrary point in time
181 * @syststamp: hwtstamp transformed to system time base
183 * Software time stamps generated by ktime_get_real() are stored in
184 * skb->tstamp. The relation between the different kinds of time
185 * stamps is as follows:
187 * syststamp and tstamp can be compared against each other in
188 * arbitrary combinations. The accuracy of a
189 * syststamp/tstamp/"syststamp from other device" comparison is
190 * limited by the accuracy of the transformation into system time
191 * base. This depends on the device driver and its underlying
194 * hwtstamps can only be compared against other hwtstamps from
197 * This structure is attached to packets as part of the
198 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
200 struct skb_shared_hwtstamps {
205 /* Definitions for tx_flags in struct skb_shared_info */
207 /* generate hardware time stamp */
208 SKBTX_HW_TSTAMP = 1 << 0,
210 /* generate software time stamp */
211 SKBTX_SW_TSTAMP = 1 << 1,
213 /* device driver is going to provide hardware time stamp */
214 SKBTX_IN_PROGRESS = 1 << 2,
216 /* device driver supports TX zero-copy buffers */
217 SKBTX_DEV_ZEROCOPY = 1 << 3,
221 * The callback notifies userspace to release buffers when skb DMA is done in
222 * lower device, the skb last reference should be 0 when calling this.
223 * The desc is used to track userspace buffer index.
226 void (*callback)(void *);
231 /* This data is invariant across clones and lives at
232 * the end of the header data, ie. at skb->end.
234 struct skb_shared_info {
235 unsigned short nr_frags;
236 unsigned short gso_size;
237 /* Warning: this field is not always filled in (UFO)! */
238 unsigned short gso_segs;
239 unsigned short gso_type;
242 struct sk_buff *frag_list;
243 struct skb_shared_hwtstamps hwtstamps;
246 * Warning : all fields before dataref are cleared in __alloc_skb()
250 /* Intermediate layers must ensure that destructor_arg
251 * remains valid until skb destructor */
252 void * destructor_arg;
254 /* must be last field, see pskb_expand_head() */
255 skb_frag_t frags[MAX_SKB_FRAGS];
258 /* We divide dataref into two halves. The higher 16 bits hold references
259 * to the payload part of skb->data. The lower 16 bits hold references to
260 * the entire skb->data. A clone of a headerless skb holds the length of
261 * the header in skb->hdr_len.
263 * All users must obey the rule that the skb->data reference count must be
264 * greater than or equal to the payload reference count.
266 * Holding a reference to the payload part means that the user does not
267 * care about modifications to the header part of skb->data.
269 #define SKB_DATAREF_SHIFT 16
270 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
274 SKB_FCLONE_UNAVAILABLE,
280 SKB_GSO_TCPV4 = 1 << 0,
281 SKB_GSO_UDP = 1 << 1,
283 /* This indicates the skb is from an untrusted source. */
284 SKB_GSO_DODGY = 1 << 2,
286 /* This indicates the tcp segment has CWR set. */
287 SKB_GSO_TCP_ECN = 1 << 3,
289 SKB_GSO_TCPV6 = 1 << 4,
291 SKB_GSO_FCOE = 1 << 5,
294 #if BITS_PER_LONG > 32
295 #define NET_SKBUFF_DATA_USES_OFFSET 1
298 #ifdef NET_SKBUFF_DATA_USES_OFFSET
299 typedef unsigned int sk_buff_data_t;
301 typedef unsigned char *sk_buff_data_t;
304 #if defined(CONFIG_NF_DEFRAG_IPV4) || defined(CONFIG_NF_DEFRAG_IPV4_MODULE) || \
305 defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE)
306 #define NET_SKBUFF_NF_DEFRAG_NEEDED 1
310 * struct sk_buff - socket buffer
311 * @next: Next buffer in list
312 * @prev: Previous buffer in list
313 * @tstamp: Time we arrived
314 * @sk: Socket we are owned by
315 * @dev: Device we arrived on/are leaving by
316 * @cb: Control buffer. Free for use by every layer. Put private vars here
317 * @_skb_refdst: destination entry (with norefcount bit)
318 * @sp: the security path, used for xfrm
319 * @len: Length of actual data
320 * @data_len: Data length
321 * @mac_len: Length of link layer header
322 * @hdr_len: writable header length of cloned skb
323 * @csum: Checksum (must include start/offset pair)
324 * @csum_start: Offset from skb->head where checksumming should start
325 * @csum_offset: Offset from csum_start where checksum should be stored
326 * @priority: Packet queueing priority
327 * @local_df: allow local fragmentation
328 * @cloned: Head may be cloned (check refcnt to be sure)
329 * @ip_summed: Driver fed us an IP checksum
330 * @nohdr: Payload reference only, must not modify header
331 * @nfctinfo: Relationship of this skb to the connection
332 * @pkt_type: Packet class
333 * @fclone: skbuff clone status
334 * @ipvs_property: skbuff is owned by ipvs
335 * @peeked: this packet has been seen already, so stats have been
336 * done for it, don't do them again
337 * @nf_trace: netfilter packet trace flag
338 * @protocol: Packet protocol from driver
339 * @destructor: Destruct function
340 * @nfct: Associated connection, if any
341 * @nfct_reasm: netfilter conntrack re-assembly pointer
342 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
343 * @skb_iif: ifindex of device we arrived on
344 * @tc_index: Traffic control index
345 * @tc_verd: traffic control verdict
346 * @rxhash: the packet hash computed on receive
347 * @queue_mapping: Queue mapping for multiqueue devices
348 * @ndisc_nodetype: router type (from link layer)
349 * @ooo_okay: allow the mapping of a socket to a queue to be changed
350 * @l4_rxhash: indicate rxhash is a canonical 4-tuple hash over transport
352 * @dma_cookie: a cookie to one of several possible DMA operations
353 * done by skb DMA functions
354 * @secmark: security marking
355 * @mark: Generic packet mark
356 * @dropcount: total number of sk_receive_queue overflows
357 * @vlan_tci: vlan tag control information
358 * @transport_header: Transport layer header
359 * @network_header: Network layer header
360 * @mac_header: Link layer header
361 * @tail: Tail pointer
363 * @head: Head of buffer
364 * @data: Data head pointer
365 * @truesize: Buffer size
366 * @users: User count - see {datagram,tcp}.c
370 /* These two members must be first. */
371 struct sk_buff *next;
372 struct sk_buff *prev;
377 struct net_device *dev;
380 * This is the control buffer. It is free to use for every
381 * layer. Please put your private variables there. If you
382 * want to keep them across layers you have to do a skb_clone()
383 * first. This is owned by whoever has the skb queued ATM.
385 char cb[48] __aligned(8);
387 unsigned long _skb_refdst;
403 kmemcheck_bitfield_begin(flags1);
414 kmemcheck_bitfield_end(flags1);
417 void (*destructor)(struct sk_buff *skb);
418 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
419 struct nf_conntrack *nfct;
421 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
422 struct sk_buff *nfct_reasm;
424 #ifdef CONFIG_BRIDGE_NETFILTER
425 struct nf_bridge_info *nf_bridge;
429 #ifdef CONFIG_NET_SCHED
430 __u16 tc_index; /* traffic control index */
431 #ifdef CONFIG_NET_CLS_ACT
432 __u16 tc_verd; /* traffic control verdict */
439 kmemcheck_bitfield_begin(flags2);
440 #ifdef CONFIG_IPV6_NDISC_NODETYPE
441 __u8 ndisc_nodetype:2;
445 kmemcheck_bitfield_end(flags2);
449 #ifdef CONFIG_NET_DMA
450 dma_cookie_t dma_cookie;
452 #ifdef CONFIG_NETWORK_SECMARK
458 __u32 reserved_tailroom;
463 sk_buff_data_t transport_header;
464 sk_buff_data_t network_header;
465 sk_buff_data_t mac_header;
466 /* These elements must be at the end, see alloc_skb() for details. */
471 unsigned int truesize;
477 * Handling routines are only of interest to the kernel
479 #include <linux/slab.h>
481 #include <asm/system.h>
484 * skb might have a dst pointer attached, refcounted or not.
485 * _skb_refdst low order bit is set if refcount was _not_ taken
487 #define SKB_DST_NOREF 1UL
488 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
491 * skb_dst - returns skb dst_entry
494 * Returns skb dst_entry, regardless of reference taken or not.
496 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
498 /* If refdst was not refcounted, check we still are in a
499 * rcu_read_lock section
501 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
502 !rcu_read_lock_held() &&
503 !rcu_read_lock_bh_held());
504 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
508 * skb_dst_set - sets skb dst
512 * Sets skb dst, assuming a reference was taken on dst and should
513 * be released by skb_dst_drop()
515 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
517 skb->_skb_refdst = (unsigned long)dst;
520 extern void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst);
523 * skb_dst_is_noref - Test if skb dst isn't refcounted
526 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
528 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
531 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
533 return (struct rtable *)skb_dst(skb);
536 extern void kfree_skb(struct sk_buff *skb);
537 extern void consume_skb(struct sk_buff *skb);
538 extern void __kfree_skb(struct sk_buff *skb);
539 extern struct sk_buff *__alloc_skb(unsigned int size,
540 gfp_t priority, int fclone, int node);
541 static inline struct sk_buff *alloc_skb(unsigned int size,
544 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
547 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
550 return __alloc_skb(size, priority, 1, NUMA_NO_NODE);
553 extern void skb_recycle(struct sk_buff *skb);
554 extern bool skb_recycle_check(struct sk_buff *skb, int skb_size);
556 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
557 extern int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
558 extern struct sk_buff *skb_clone(struct sk_buff *skb,
560 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
562 extern struct sk_buff *pskb_copy(struct sk_buff *skb,
564 extern int pskb_expand_head(struct sk_buff *skb,
565 int nhead, int ntail,
567 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
568 unsigned int headroom);
569 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
570 int newheadroom, int newtailroom,
572 extern int skb_to_sgvec(struct sk_buff *skb,
573 struct scatterlist *sg, int offset,
575 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
576 struct sk_buff **trailer);
577 extern int skb_pad(struct sk_buff *skb, int pad);
578 #define dev_kfree_skb(a) consume_skb(a)
580 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
581 int getfrag(void *from, char *to, int offset,
582 int len,int odd, struct sk_buff *skb),
583 void *from, int length);
585 struct skb_seq_state {
589 __u32 stepped_offset;
590 struct sk_buff *root_skb;
591 struct sk_buff *cur_skb;
595 extern void skb_prepare_seq_read(struct sk_buff *skb,
596 unsigned int from, unsigned int to,
597 struct skb_seq_state *st);
598 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
599 struct skb_seq_state *st);
600 extern void skb_abort_seq_read(struct skb_seq_state *st);
602 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
603 unsigned int to, struct ts_config *config,
604 struct ts_state *state);
606 extern void __skb_get_rxhash(struct sk_buff *skb);
607 static inline __u32 skb_get_rxhash(struct sk_buff *skb)
610 __skb_get_rxhash(skb);
615 #ifdef NET_SKBUFF_DATA_USES_OFFSET
616 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
618 return skb->head + skb->end;
621 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
626 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
631 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
633 return skb->end - skb->head;
638 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
640 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
642 return &skb_shinfo(skb)->hwtstamps;
646 * skb_queue_empty - check if a queue is empty
649 * Returns true if the queue is empty, false otherwise.
651 static inline int skb_queue_empty(const struct sk_buff_head *list)
653 return list->next == (struct sk_buff *)list;
657 * skb_queue_is_last - check if skb is the last entry in the queue
661 * Returns true if @skb is the last buffer on the list.
663 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
664 const struct sk_buff *skb)
666 return skb->next == (struct sk_buff *)list;
670 * skb_queue_is_first - check if skb is the first entry in the queue
674 * Returns true if @skb is the first buffer on the list.
676 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
677 const struct sk_buff *skb)
679 return skb->prev == (struct sk_buff *)list;
683 * skb_queue_next - return the next packet in the queue
685 * @skb: current buffer
687 * Return the next packet in @list after @skb. It is only valid to
688 * call this if skb_queue_is_last() evaluates to false.
690 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
691 const struct sk_buff *skb)
693 /* This BUG_ON may seem severe, but if we just return then we
694 * are going to dereference garbage.
696 BUG_ON(skb_queue_is_last(list, skb));
701 * skb_queue_prev - return the prev packet in the queue
703 * @skb: current buffer
705 * Return the prev packet in @list before @skb. It is only valid to
706 * call this if skb_queue_is_first() evaluates to false.
708 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
709 const struct sk_buff *skb)
711 /* This BUG_ON may seem severe, but if we just return then we
712 * are going to dereference garbage.
714 BUG_ON(skb_queue_is_first(list, skb));
719 * skb_get - reference buffer
720 * @skb: buffer to reference
722 * Makes another reference to a socket buffer and returns a pointer
725 static inline struct sk_buff *skb_get(struct sk_buff *skb)
727 atomic_inc(&skb->users);
732 * If users == 1, we are the only owner and are can avoid redundant
737 * skb_cloned - is the buffer a clone
738 * @skb: buffer to check
740 * Returns true if the buffer was generated with skb_clone() and is
741 * one of multiple shared copies of the buffer. Cloned buffers are
742 * shared data so must not be written to under normal circumstances.
744 static inline int skb_cloned(const struct sk_buff *skb)
746 return skb->cloned &&
747 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
750 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
752 might_sleep_if(pri & __GFP_WAIT);
755 return pskb_expand_head(skb, 0, 0, pri);
761 * skb_header_cloned - is the header a clone
762 * @skb: buffer to check
764 * Returns true if modifying the header part of the buffer requires
765 * the data to be copied.
767 static inline int skb_header_cloned(const struct sk_buff *skb)
774 dataref = atomic_read(&skb_shinfo(skb)->dataref);
775 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
780 * skb_header_release - release reference to header
781 * @skb: buffer to operate on
783 * Drop a reference to the header part of the buffer. This is done
784 * by acquiring a payload reference. You must not read from the header
785 * part of skb->data after this.
787 static inline void skb_header_release(struct sk_buff *skb)
791 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
795 * skb_shared - is the buffer shared
796 * @skb: buffer to check
798 * Returns true if more than one person has a reference to this
801 static inline int skb_shared(const struct sk_buff *skb)
803 return atomic_read(&skb->users) != 1;
807 * skb_share_check - check if buffer is shared and if so clone it
808 * @skb: buffer to check
809 * @pri: priority for memory allocation
811 * If the buffer is shared the buffer is cloned and the old copy
812 * drops a reference. A new clone with a single reference is returned.
813 * If the buffer is not shared the original buffer is returned. When
814 * being called from interrupt status or with spinlocks held pri must
817 * NULL is returned on a memory allocation failure.
819 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
822 might_sleep_if(pri & __GFP_WAIT);
823 if (skb_shared(skb)) {
824 struct sk_buff *nskb = skb_clone(skb, pri);
832 * Copy shared buffers into a new sk_buff. We effectively do COW on
833 * packets to handle cases where we have a local reader and forward
834 * and a couple of other messy ones. The normal one is tcpdumping
835 * a packet thats being forwarded.
839 * skb_unshare - make a copy of a shared buffer
840 * @skb: buffer to check
841 * @pri: priority for memory allocation
843 * If the socket buffer is a clone then this function creates a new
844 * copy of the data, drops a reference count on the old copy and returns
845 * the new copy with the reference count at 1. If the buffer is not a clone
846 * the original buffer is returned. When called with a spinlock held or
847 * from interrupt state @pri must be %GFP_ATOMIC
849 * %NULL is returned on a memory allocation failure.
851 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
854 might_sleep_if(pri & __GFP_WAIT);
855 if (skb_cloned(skb)) {
856 struct sk_buff *nskb = skb_copy(skb, pri);
857 kfree_skb(skb); /* Free our shared copy */
864 * skb_peek - peek at the head of an &sk_buff_head
865 * @list_: list to peek at
867 * Peek an &sk_buff. Unlike most other operations you _MUST_
868 * be careful with this one. A peek leaves the buffer on the
869 * list and someone else may run off with it. You must hold
870 * the appropriate locks or have a private queue to do this.
872 * Returns %NULL for an empty list or a pointer to the head element.
873 * The reference count is not incremented and the reference is therefore
874 * volatile. Use with caution.
876 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
878 struct sk_buff *list = ((const struct sk_buff *)list_)->next;
879 if (list == (struct sk_buff *)list_)
885 * skb_peek_tail - peek at the tail of an &sk_buff_head
886 * @list_: list to peek at
888 * Peek an &sk_buff. Unlike most other operations you _MUST_
889 * be careful with this one. A peek leaves the buffer on the
890 * list and someone else may run off with it. You must hold
891 * the appropriate locks or have a private queue to do this.
893 * Returns %NULL for an empty list or a pointer to the tail element.
894 * The reference count is not incremented and the reference is therefore
895 * volatile. Use with caution.
897 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
899 struct sk_buff *list = ((const struct sk_buff *)list_)->prev;
900 if (list == (struct sk_buff *)list_)
906 * skb_queue_len - get queue length
907 * @list_: list to measure
909 * Return the length of an &sk_buff queue.
911 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
917 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
918 * @list: queue to initialize
920 * This initializes only the list and queue length aspects of
921 * an sk_buff_head object. This allows to initialize the list
922 * aspects of an sk_buff_head without reinitializing things like
923 * the spinlock. It can also be used for on-stack sk_buff_head
924 * objects where the spinlock is known to not be used.
926 static inline void __skb_queue_head_init(struct sk_buff_head *list)
928 list->prev = list->next = (struct sk_buff *)list;
933 * This function creates a split out lock class for each invocation;
934 * this is needed for now since a whole lot of users of the skb-queue
935 * infrastructure in drivers have different locking usage (in hardirq)
936 * than the networking core (in softirq only). In the long run either the
937 * network layer or drivers should need annotation to consolidate the
938 * main types of usage into 3 classes.
940 static inline void skb_queue_head_init(struct sk_buff_head *list)
942 spin_lock_init(&list->lock);
943 __skb_queue_head_init(list);
946 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
947 struct lock_class_key *class)
949 skb_queue_head_init(list);
950 lockdep_set_class(&list->lock, class);
954 * Insert an sk_buff on a list.
956 * The "__skb_xxxx()" functions are the non-atomic ones that
957 * can only be called with interrupts disabled.
959 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
960 static inline void __skb_insert(struct sk_buff *newsk,
961 struct sk_buff *prev, struct sk_buff *next,
962 struct sk_buff_head *list)
966 next->prev = prev->next = newsk;
970 static inline void __skb_queue_splice(const struct sk_buff_head *list,
971 struct sk_buff *prev,
972 struct sk_buff *next)
974 struct sk_buff *first = list->next;
975 struct sk_buff *last = list->prev;
985 * skb_queue_splice - join two skb lists, this is designed for stacks
986 * @list: the new list to add
987 * @head: the place to add it in the first list
989 static inline void skb_queue_splice(const struct sk_buff_head *list,
990 struct sk_buff_head *head)
992 if (!skb_queue_empty(list)) {
993 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
994 head->qlen += list->qlen;
999 * skb_queue_splice - join two skb lists and reinitialise the emptied list
1000 * @list: the new list to add
1001 * @head: the place to add it in the first list
1003 * The list at @list is reinitialised
1005 static inline void skb_queue_splice_init(struct sk_buff_head *list,
1006 struct sk_buff_head *head)
1008 if (!skb_queue_empty(list)) {
1009 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1010 head->qlen += list->qlen;
1011 __skb_queue_head_init(list);
1016 * skb_queue_splice_tail - join two skb lists, each list being a queue
1017 * @list: the new list to add
1018 * @head: the place to add it in the first list
1020 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1021 struct sk_buff_head *head)
1023 if (!skb_queue_empty(list)) {
1024 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1025 head->qlen += list->qlen;
1030 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
1031 * @list: the new list to add
1032 * @head: the place to add it in the first list
1034 * Each of the lists is a queue.
1035 * The list at @list is reinitialised
1037 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
1038 struct sk_buff_head *head)
1040 if (!skb_queue_empty(list)) {
1041 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1042 head->qlen += list->qlen;
1043 __skb_queue_head_init(list);
1048 * __skb_queue_after - queue a buffer at the list head
1049 * @list: list to use
1050 * @prev: place after this buffer
1051 * @newsk: buffer to queue
1053 * Queue a buffer int the middle of a list. This function takes no locks
1054 * and you must therefore hold required locks before calling it.
1056 * A buffer cannot be placed on two lists at the same time.
1058 static inline void __skb_queue_after(struct sk_buff_head *list,
1059 struct sk_buff *prev,
1060 struct sk_buff *newsk)
1062 __skb_insert(newsk, prev, prev->next, list);
1065 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
1066 struct sk_buff_head *list);
1068 static inline void __skb_queue_before(struct sk_buff_head *list,
1069 struct sk_buff *next,
1070 struct sk_buff *newsk)
1072 __skb_insert(newsk, next->prev, next, list);
1076 * __skb_queue_head - queue a buffer at the list head
1077 * @list: list to use
1078 * @newsk: buffer to queue
1080 * Queue a buffer at the start of a list. This function takes no locks
1081 * and you must therefore hold required locks before calling it.
1083 * A buffer cannot be placed on two lists at the same time.
1085 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
1086 static inline void __skb_queue_head(struct sk_buff_head *list,
1087 struct sk_buff *newsk)
1089 __skb_queue_after(list, (struct sk_buff *)list, newsk);
1093 * __skb_queue_tail - queue a buffer at the list tail
1094 * @list: list to use
1095 * @newsk: buffer to queue
1097 * Queue a buffer at the end of a list. This function takes no locks
1098 * and you must therefore hold required locks before calling it.
1100 * A buffer cannot be placed on two lists at the same time.
1102 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
1103 static inline void __skb_queue_tail(struct sk_buff_head *list,
1104 struct sk_buff *newsk)
1106 __skb_queue_before(list, (struct sk_buff *)list, newsk);
1110 * remove sk_buff from list. _Must_ be called atomically, and with
1113 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
1114 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
1116 struct sk_buff *next, *prev;
1121 skb->next = skb->prev = NULL;
1127 * __skb_dequeue - remove from the head of the queue
1128 * @list: list to dequeue from
1130 * Remove the head of the list. This function does not take any locks
1131 * so must be used with appropriate locks held only. The head item is
1132 * returned or %NULL if the list is empty.
1134 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1135 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1137 struct sk_buff *skb = skb_peek(list);
1139 __skb_unlink(skb, list);
1144 * __skb_dequeue_tail - remove from the tail of the queue
1145 * @list: list to dequeue from
1147 * Remove the tail of the list. This function does not take any locks
1148 * so must be used with appropriate locks held only. The tail item is
1149 * returned or %NULL if the list is empty.
1151 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1152 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1154 struct sk_buff *skb = skb_peek_tail(list);
1156 __skb_unlink(skb, list);
1161 static inline int skb_is_nonlinear(const struct sk_buff *skb)
1163 return skb->data_len;
1166 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1168 return skb->len - skb->data_len;
1171 static inline int skb_pagelen(const struct sk_buff *skb)
1175 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1176 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
1177 return len + skb_headlen(skb);
1180 static inline bool skb_has_frags(const struct sk_buff *skb)
1182 return skb_shinfo(skb)->nr_frags;
1186 * __skb_fill_page_desc - initialise a paged fragment in an skb
1187 * @skb: buffer containing fragment to be initialised
1188 * @i: paged fragment index to initialise
1189 * @page: the page to use for this fragment
1190 * @off: the offset to the data with @page
1191 * @size: the length of the data
1193 * Initialises the @i'th fragment of @skb to point to &size bytes at
1194 * offset @off within @page.
1196 * Does not take any additional reference on the fragment.
1198 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
1199 struct page *page, int off, int size)
1201 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1203 frag->page.p = page;
1204 frag->page_offset = off;
1205 skb_frag_size_set(frag, size);
1209 * skb_fill_page_desc - initialise a paged fragment in an skb
1210 * @skb: buffer containing fragment to be initialised
1211 * @i: paged fragment index to initialise
1212 * @page: the page to use for this fragment
1213 * @off: the offset to the data with @page
1214 * @size: the length of the data
1216 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1217 * @skb to point to &size bytes at offset @off within @page. In
1218 * addition updates @skb such that @i is the last fragment.
1220 * Does not take any additional reference on the fragment.
1222 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1223 struct page *page, int off, int size)
1225 __skb_fill_page_desc(skb, i, page, off, size);
1226 skb_shinfo(skb)->nr_frags = i + 1;
1229 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1232 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1233 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1234 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1236 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1237 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1239 return skb->head + skb->tail;
1242 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1244 skb->tail = skb->data - skb->head;
1247 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1249 skb_reset_tail_pointer(skb);
1250 skb->tail += offset;
1252 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1253 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1258 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1260 skb->tail = skb->data;
1263 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1265 skb->tail = skb->data + offset;
1268 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1271 * Add data to an sk_buff
1273 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1274 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1276 unsigned char *tmp = skb_tail_pointer(skb);
1277 SKB_LINEAR_ASSERT(skb);
1283 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1284 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1291 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1292 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1295 BUG_ON(skb->len < skb->data_len);
1296 return skb->data += len;
1299 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len)
1301 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
1304 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1306 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1308 if (len > skb_headlen(skb) &&
1309 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1312 return skb->data += len;
1315 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1317 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1320 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1322 if (likely(len <= skb_headlen(skb)))
1324 if (unlikely(len > skb->len))
1326 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1330 * skb_headroom - bytes at buffer head
1331 * @skb: buffer to check
1333 * Return the number of bytes of free space at the head of an &sk_buff.
1335 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1337 return skb->data - skb->head;
1341 * skb_tailroom - bytes at buffer end
1342 * @skb: buffer to check
1344 * Return the number of bytes of free space at the tail of an sk_buff
1346 static inline int skb_tailroom(const struct sk_buff *skb)
1348 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1352 * skb_availroom - bytes at buffer end
1353 * @skb: buffer to check
1355 * Return the number of bytes of free space at the tail of an sk_buff
1356 * allocated by sk_stream_alloc()
1358 static inline int skb_availroom(const struct sk_buff *skb)
1360 if (skb_is_nonlinear(skb))
1363 return skb->end - skb->tail - skb->reserved_tailroom;
1367 * skb_reserve - adjust headroom
1368 * @skb: buffer to alter
1369 * @len: bytes to move
1371 * Increase the headroom of an empty &sk_buff by reducing the tail
1372 * room. This is only allowed for an empty buffer.
1374 static inline void skb_reserve(struct sk_buff *skb, int len)
1381 * skb_tailroom_reserve - adjust reserved_tailroom
1382 * @skb: buffer to alter
1383 * @mtu: maximum amount of headlen permitted
1384 * @needed_tailroom: minimum amount of reserved_tailroom
1386 * Set reserved_tailroom so that headlen can be as large as possible but
1387 * not larger than mtu and tailroom cannot be smaller than
1389 * The required headroom should already have been reserved before using
1392 static inline void skb_tailroom_reserve(struct sk_buff *skb, unsigned int mtu,
1393 unsigned int needed_tailroom)
1395 SKB_LINEAR_ASSERT(skb);
1396 if (mtu < skb_tailroom(skb) - needed_tailroom)
1397 /* use at most mtu */
1398 skb->reserved_tailroom = skb_tailroom(skb) - mtu;
1400 /* use up to all available space */
1401 skb->reserved_tailroom = needed_tailroom;
1404 static inline void skb_reset_mac_len(struct sk_buff *skb)
1406 skb->mac_len = skb->network_header - skb->mac_header;
1409 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1410 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1412 return skb->head + skb->transport_header;
1415 static inline void skb_reset_transport_header(struct sk_buff *skb)
1417 skb->transport_header = skb->data - skb->head;
1420 static inline void skb_set_transport_header(struct sk_buff *skb,
1423 skb_reset_transport_header(skb);
1424 skb->transport_header += offset;
1427 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1429 return skb->head + skb->network_header;
1432 static inline void skb_reset_network_header(struct sk_buff *skb)
1434 skb->network_header = skb->data - skb->head;
1437 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1439 skb_reset_network_header(skb);
1440 skb->network_header += offset;
1443 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1445 return skb->head + skb->mac_header;
1448 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1450 return skb->mac_header != ~0U;
1453 static inline void skb_reset_mac_header(struct sk_buff *skb)
1455 skb->mac_header = skb->data - skb->head;
1458 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1460 skb_reset_mac_header(skb);
1461 skb->mac_header += offset;
1464 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1466 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1468 return skb->transport_header;
1471 static inline void skb_reset_transport_header(struct sk_buff *skb)
1473 skb->transport_header = skb->data;
1476 static inline void skb_set_transport_header(struct sk_buff *skb,
1479 skb->transport_header = skb->data + offset;
1482 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1484 return skb->network_header;
1487 static inline void skb_reset_network_header(struct sk_buff *skb)
1489 skb->network_header = skb->data;
1492 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1494 skb->network_header = skb->data + offset;
1497 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1499 return skb->mac_header;
1502 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1504 return skb->mac_header != NULL;
1507 static inline void skb_reset_mac_header(struct sk_buff *skb)
1509 skb->mac_header = skb->data;
1512 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1514 skb->mac_header = skb->data + offset;
1516 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1518 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
1520 if (skb_mac_header_was_set(skb)) {
1521 const unsigned char *old_mac = skb_mac_header(skb);
1523 skb_set_mac_header(skb, -skb->mac_len);
1524 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
1528 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
1530 return skb->csum_start - skb_headroom(skb);
1533 static inline int skb_transport_offset(const struct sk_buff *skb)
1535 return skb_transport_header(skb) - skb->data;
1538 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1540 return skb->transport_header - skb->network_header;
1543 static inline int skb_network_offset(const struct sk_buff *skb)
1545 return skb_network_header(skb) - skb->data;
1548 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
1550 return pskb_may_pull(skb, skb_network_offset(skb) + len);
1554 * CPUs often take a performance hit when accessing unaligned memory
1555 * locations. The actual performance hit varies, it can be small if the
1556 * hardware handles it or large if we have to take an exception and fix it
1559 * Since an ethernet header is 14 bytes network drivers often end up with
1560 * the IP header at an unaligned offset. The IP header can be aligned by
1561 * shifting the start of the packet by 2 bytes. Drivers should do this
1564 * skb_reserve(skb, NET_IP_ALIGN);
1566 * The downside to this alignment of the IP header is that the DMA is now
1567 * unaligned. On some architectures the cost of an unaligned DMA is high
1568 * and this cost outweighs the gains made by aligning the IP header.
1570 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1573 #ifndef NET_IP_ALIGN
1574 #define NET_IP_ALIGN 2
1578 * The networking layer reserves some headroom in skb data (via
1579 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1580 * the header has to grow. In the default case, if the header has to grow
1581 * 32 bytes or less we avoid the reallocation.
1583 * Unfortunately this headroom changes the DMA alignment of the resulting
1584 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1585 * on some architectures. An architecture can override this value,
1586 * perhaps setting it to a cacheline in size (since that will maintain
1587 * cacheline alignment of the DMA). It must be a power of 2.
1589 * Various parts of the networking layer expect at least 32 bytes of
1590 * headroom, you should not reduce this.
1592 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1593 * to reduce average number of cache lines per packet.
1594 * get_rps_cpus() for example only access one 64 bytes aligned block :
1595 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1598 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1601 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1603 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1605 if (unlikely(skb_is_nonlinear(skb))) {
1610 skb_set_tail_pointer(skb, len);
1613 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1615 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1618 return ___pskb_trim(skb, len);
1619 __skb_trim(skb, len);
1623 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1625 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1629 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1630 * @skb: buffer to alter
1633 * This is identical to pskb_trim except that the caller knows that
1634 * the skb is not cloned so we should never get an error due to out-
1637 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1639 int err = pskb_trim(skb, len);
1644 * skb_orphan - orphan a buffer
1645 * @skb: buffer to orphan
1647 * If a buffer currently has an owner then we call the owner's
1648 * destructor function and make the @skb unowned. The buffer continues
1649 * to exist but is no longer charged to its former owner.
1651 static inline void skb_orphan(struct sk_buff *skb)
1653 if (skb->destructor)
1654 skb->destructor(skb);
1655 skb->destructor = NULL;
1660 * skb_orphan_frags - orphan the frags contained in a buffer
1661 * @skb: buffer to orphan frags from
1662 * @gfp_mask: allocation mask for replacement pages
1664 * For each frag in the SKB which needs a destructor (i.e. has an
1665 * owner) create a copy of that frag and release the original
1666 * page by calling the destructor.
1668 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
1670 if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY)))
1672 return skb_copy_ubufs(skb, gfp_mask);
1676 * __skb_queue_purge - empty a list
1677 * @list: list to empty
1679 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1680 * the list and one reference dropped. This function does not take the
1681 * list lock and the caller must hold the relevant locks to use it.
1683 extern void skb_queue_purge(struct sk_buff_head *list);
1684 static inline void __skb_queue_purge(struct sk_buff_head *list)
1686 struct sk_buff *skb;
1687 while ((skb = __skb_dequeue(list)) != NULL)
1692 * __dev_alloc_skb - allocate an skbuff for receiving
1693 * @length: length to allocate
1694 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1696 * Allocate a new &sk_buff and assign it a usage count of one. The
1697 * buffer has unspecified headroom built in. Users should allocate
1698 * the headroom they think they need without accounting for the
1699 * built in space. The built in space is used for optimisations.
1701 * %NULL is returned if there is no free memory.
1703 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1706 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1708 skb_reserve(skb, NET_SKB_PAD);
1712 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1714 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1715 unsigned int length, gfp_t gfp_mask);
1718 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1719 * @dev: network device to receive on
1720 * @length: length to allocate
1722 * Allocate a new &sk_buff and assign it a usage count of one. The
1723 * buffer has unspecified headroom built in. Users should allocate
1724 * the headroom they think they need without accounting for the
1725 * built in space. The built in space is used for optimisations.
1727 * %NULL is returned if there is no free memory. Although this function
1728 * allocates memory it can be called from an interrupt.
1730 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1731 unsigned int length)
1733 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1736 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
1737 unsigned int length, gfp_t gfp)
1739 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
1741 if (NET_IP_ALIGN && skb)
1742 skb_reserve(skb, NET_IP_ALIGN);
1746 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
1747 unsigned int length)
1749 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
1753 * __netdev_alloc_page - allocate a page for ps-rx on a specific device
1754 * @dev: network device to receive on
1755 * @gfp_mask: alloc_pages_node mask
1757 * Allocate a new page. dev currently unused.
1759 * %NULL is returned if there is no free memory.
1761 static inline struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask)
1763 return alloc_pages_node(NUMA_NO_NODE, gfp_mask, 0);
1767 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1768 * @dev: network device to receive on
1770 * Allocate a new page. dev currently unused.
1772 * %NULL is returned if there is no free memory.
1774 static inline struct page *netdev_alloc_page(struct net_device *dev)
1776 return __netdev_alloc_page(dev, GFP_ATOMIC);
1779 static inline void netdev_free_page(struct net_device *dev, struct page *page)
1785 * skb_frag_page - retrieve the page refered to by a paged fragment
1786 * @frag: the paged fragment
1788 * Returns the &struct page associated with @frag.
1790 static inline struct page *skb_frag_page(const skb_frag_t *frag)
1792 return frag->page.p;
1796 * __skb_frag_ref - take an addition reference on a paged fragment.
1797 * @frag: the paged fragment
1799 * Takes an additional reference on the paged fragment @frag.
1801 static inline void __skb_frag_ref(skb_frag_t *frag)
1803 get_page(skb_frag_page(frag));
1807 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
1809 * @f: the fragment offset.
1811 * Takes an additional reference on the @f'th paged fragment of @skb.
1813 static inline void skb_frag_ref(struct sk_buff *skb, int f)
1815 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
1819 * __skb_frag_unref - release a reference on a paged fragment.
1820 * @frag: the paged fragment
1822 * Releases a reference on the paged fragment @frag.
1824 static inline void __skb_frag_unref(skb_frag_t *frag)
1826 put_page(skb_frag_page(frag));
1830 * skb_frag_unref - release a reference on a paged fragment of an skb.
1832 * @f: the fragment offset
1834 * Releases a reference on the @f'th paged fragment of @skb.
1836 static inline void skb_frag_unref(struct sk_buff *skb, int f)
1838 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
1842 * skb_frag_address - gets the address of the data contained in a paged fragment
1843 * @frag: the paged fragment buffer
1845 * Returns the address of the data within @frag. The page must already
1848 static inline void *skb_frag_address(const skb_frag_t *frag)
1850 return page_address(skb_frag_page(frag)) + frag->page_offset;
1854 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
1855 * @frag: the paged fragment buffer
1857 * Returns the address of the data within @frag. Checks that the page
1858 * is mapped and returns %NULL otherwise.
1860 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
1862 void *ptr = page_address(skb_frag_page(frag));
1866 return ptr + frag->page_offset;
1870 * __skb_frag_set_page - sets the page contained in a paged fragment
1871 * @frag: the paged fragment
1872 * @page: the page to set
1874 * Sets the fragment @frag to contain @page.
1876 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
1878 frag->page.p = page;
1882 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
1884 * @f: the fragment offset
1885 * @page: the page to set
1887 * Sets the @f'th fragment of @skb to contain @page.
1889 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
1892 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
1896 * skb_frag_dma_map - maps a paged fragment via the DMA API
1897 * @dev: the device to map the fragment to
1898 * @frag: the paged fragment to map
1899 * @offset: the offset within the fragment (starting at the
1900 * fragment's own offset)
1901 * @size: the number of bytes to map
1902 * @dir: the direction of the mapping (%PCI_DMA_*)
1904 * Maps the page associated with @frag to @device.
1906 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
1907 const skb_frag_t *frag,
1908 size_t offset, size_t size,
1909 enum dma_data_direction dir)
1911 return dma_map_page(dev, skb_frag_page(frag),
1912 frag->page_offset + offset, size, dir);
1916 * skb_clone_writable - is the header of a clone writable
1917 * @skb: buffer to check
1918 * @len: length up to which to write
1920 * Returns true if modifying the header part of the cloned buffer
1921 * does not requires the data to be copied.
1923 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
1925 return !skb_header_cloned(skb) &&
1926 skb_headroom(skb) + len <= skb->hdr_len;
1929 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1934 if (headroom > skb_headroom(skb))
1935 delta = headroom - skb_headroom(skb);
1937 if (delta || cloned)
1938 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1944 * skb_cow - copy header of skb when it is required
1945 * @skb: buffer to cow
1946 * @headroom: needed headroom
1948 * If the skb passed lacks sufficient headroom or its data part
1949 * is shared, data is reallocated. If reallocation fails, an error
1950 * is returned and original skb is not changed.
1952 * The result is skb with writable area skb->head...skb->tail
1953 * and at least @headroom of space at head.
1955 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1957 return __skb_cow(skb, headroom, skb_cloned(skb));
1961 * skb_cow_head - skb_cow but only making the head writable
1962 * @skb: buffer to cow
1963 * @headroom: needed headroom
1965 * This function is identical to skb_cow except that we replace the
1966 * skb_cloned check by skb_header_cloned. It should be used when
1967 * you only need to push on some header and do not need to modify
1970 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1972 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1976 * skb_padto - pad an skbuff up to a minimal size
1977 * @skb: buffer to pad
1978 * @len: minimal length
1980 * Pads up a buffer to ensure the trailing bytes exist and are
1981 * blanked. If the buffer already contains sufficient data it
1982 * is untouched. Otherwise it is extended. Returns zero on
1983 * success. The skb is freed on error.
1986 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1988 unsigned int size = skb->len;
1989 if (likely(size >= len))
1991 return skb_pad(skb, len - size);
1994 static inline int skb_add_data(struct sk_buff *skb,
1995 char __user *from, int copy)
1997 const int off = skb->len;
1999 if (skb->ip_summed == CHECKSUM_NONE) {
2001 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
2004 skb->csum = csum_block_add(skb->csum, csum, off);
2007 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
2010 __skb_trim(skb, off);
2014 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
2015 const struct page *page, int off)
2018 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
2020 return page == skb_frag_page(frag) &&
2021 off == frag->page_offset + skb_frag_size(frag);
2026 static inline int __skb_linearize(struct sk_buff *skb)
2028 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
2032 * skb_linearize - convert paged skb to linear one
2033 * @skb: buffer to linarize
2035 * If there is no free memory -ENOMEM is returned, otherwise zero
2036 * is returned and the old skb data released.
2038 static inline int skb_linearize(struct sk_buff *skb)
2040 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
2044 * skb_linearize_cow - make sure skb is linear and writable
2045 * @skb: buffer to process
2047 * If there is no free memory -ENOMEM is returned, otherwise zero
2048 * is returned and the old skb data released.
2050 static inline int skb_linearize_cow(struct sk_buff *skb)
2052 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
2053 __skb_linearize(skb) : 0;
2057 * skb_postpull_rcsum - update checksum for received skb after pull
2058 * @skb: buffer to update
2059 * @start: start of data before pull
2060 * @len: length of data pulled
2062 * After doing a pull on a received packet, you need to call this to
2063 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2064 * CHECKSUM_NONE so that it can be recomputed from scratch.
2067 static inline void skb_postpull_rcsum(struct sk_buff *skb,
2068 const void *start, unsigned int len)
2070 if (skb->ip_summed == CHECKSUM_COMPLETE)
2071 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
2072 else if (skb->ip_summed == CHECKSUM_PARTIAL &&
2073 skb_checksum_start_offset(skb) < 0)
2074 skb->ip_summed = CHECKSUM_NONE;
2077 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
2080 * pskb_trim_rcsum - trim received skb and update checksum
2081 * @skb: buffer to trim
2084 * This is exactly the same as pskb_trim except that it ensures the
2085 * checksum of received packets are still valid after the operation.
2088 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
2090 if (likely(len >= skb->len))
2092 if (skb->ip_summed == CHECKSUM_COMPLETE)
2093 skb->ip_summed = CHECKSUM_NONE;
2094 return __pskb_trim(skb, len);
2097 #define skb_queue_walk(queue, skb) \
2098 for (skb = (queue)->next; \
2099 skb != (struct sk_buff *)(queue); \
2102 #define skb_queue_walk_safe(queue, skb, tmp) \
2103 for (skb = (queue)->next, tmp = skb->next; \
2104 skb != (struct sk_buff *)(queue); \
2105 skb = tmp, tmp = skb->next)
2107 #define skb_queue_walk_from(queue, skb) \
2108 for (; skb != (struct sk_buff *)(queue); \
2111 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2112 for (tmp = skb->next; \
2113 skb != (struct sk_buff *)(queue); \
2114 skb = tmp, tmp = skb->next)
2116 #define skb_queue_reverse_walk(queue, skb) \
2117 for (skb = (queue)->prev; \
2118 skb != (struct sk_buff *)(queue); \
2121 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2122 for (skb = (queue)->prev, tmp = skb->prev; \
2123 skb != (struct sk_buff *)(queue); \
2124 skb = tmp, tmp = skb->prev)
2126 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2127 for (tmp = skb->prev; \
2128 skb != (struct sk_buff *)(queue); \
2129 skb = tmp, tmp = skb->prev)
2131 static inline bool skb_has_frag_list(const struct sk_buff *skb)
2133 return skb_shinfo(skb)->frag_list != NULL;
2136 static inline void skb_frag_list_init(struct sk_buff *skb)
2138 skb_shinfo(skb)->frag_list = NULL;
2141 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
2143 frag->next = skb_shinfo(skb)->frag_list;
2144 skb_shinfo(skb)->frag_list = frag;
2147 #define skb_walk_frags(skb, iter) \
2148 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2150 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
2151 int *peeked, int *err);
2152 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
2153 int noblock, int *err);
2154 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
2155 struct poll_table_struct *wait);
2156 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
2157 int offset, struct iovec *to,
2159 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
2162 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
2164 const struct iovec *from,
2167 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from,
2169 const struct iovec *to,
2172 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
2173 extern void skb_free_datagram_locked(struct sock *sk,
2174 struct sk_buff *skb);
2175 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
2176 unsigned int flags);
2177 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
2178 int len, __wsum csum);
2179 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
2181 extern int skb_store_bits(struct sk_buff *skb, int offset,
2182 const void *from, int len);
2183 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
2184 int offset, u8 *to, int len,
2186 extern int skb_splice_bits(struct sk_buff *skb,
2187 unsigned int offset,
2188 struct pipe_inode_info *pipe,
2190 unsigned int flags);
2191 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
2192 extern void skb_split(struct sk_buff *skb,
2193 struct sk_buff *skb1, const u32 len);
2194 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
2197 extern struct sk_buff *skb_segment(struct sk_buff *skb, u32 features);
2199 unsigned int skb_gso_transport_seglen(const struct sk_buff *skb);
2201 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
2202 int len, void *buffer)
2204 int hlen = skb_headlen(skb);
2206 if (hlen - offset >= len)
2207 return skb->data + offset;
2209 if (skb_copy_bits(skb, offset, buffer, len) < 0)
2215 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
2217 const unsigned int len)
2219 memcpy(to, skb->data, len);
2222 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
2223 const int offset, void *to,
2224 const unsigned int len)
2226 memcpy(to, skb->data + offset, len);
2229 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
2231 const unsigned int len)
2233 memcpy(skb->data, from, len);
2236 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
2239 const unsigned int len)
2241 memcpy(skb->data + offset, from, len);
2244 extern void skb_init(void);
2246 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
2252 * skb_get_timestamp - get timestamp from a skb
2253 * @skb: skb to get stamp from
2254 * @stamp: pointer to struct timeval to store stamp in
2256 * Timestamps are stored in the skb as offsets to a base timestamp.
2257 * This function converts the offset back to a struct timeval and stores
2260 static inline void skb_get_timestamp(const struct sk_buff *skb,
2261 struct timeval *stamp)
2263 *stamp = ktime_to_timeval(skb->tstamp);
2266 static inline void skb_get_timestampns(const struct sk_buff *skb,
2267 struct timespec *stamp)
2269 *stamp = ktime_to_timespec(skb->tstamp);
2272 static inline void __net_timestamp(struct sk_buff *skb)
2274 skb->tstamp = ktime_get_real();
2277 static inline ktime_t net_timedelta(ktime_t t)
2279 return ktime_sub(ktime_get_real(), t);
2282 static inline ktime_t net_invalid_timestamp(void)
2284 return ktime_set(0, 0);
2287 extern void skb_timestamping_init(void);
2289 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2291 extern void skb_clone_tx_timestamp(struct sk_buff *skb);
2292 extern bool skb_defer_rx_timestamp(struct sk_buff *skb);
2294 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2296 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
2300 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
2305 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2308 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2310 * PHY drivers may accept clones of transmitted packets for
2311 * timestamping via their phy_driver.txtstamp method. These drivers
2312 * must call this function to return the skb back to the stack, with
2313 * or without a timestamp.
2315 * @skb: clone of the the original outgoing packet
2316 * @hwtstamps: hardware time stamps, may be NULL if not available
2319 void skb_complete_tx_timestamp(struct sk_buff *skb,
2320 struct skb_shared_hwtstamps *hwtstamps);
2323 * skb_tstamp_tx - queue clone of skb with send time stamps
2324 * @orig_skb: the original outgoing packet
2325 * @hwtstamps: hardware time stamps, may be NULL if not available
2327 * If the skb has a socket associated, then this function clones the
2328 * skb (thus sharing the actual data and optional structures), stores
2329 * the optional hardware time stamping information (if non NULL) or
2330 * generates a software time stamp (otherwise), then queues the clone
2331 * to the error queue of the socket. Errors are silently ignored.
2333 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
2334 struct skb_shared_hwtstamps *hwtstamps);
2336 static inline void sw_tx_timestamp(struct sk_buff *skb)
2338 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP &&
2339 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
2340 skb_tstamp_tx(skb, NULL);
2344 * skb_tx_timestamp() - Driver hook for transmit timestamping
2346 * Ethernet MAC Drivers should call this function in their hard_xmit()
2347 * function immediately before giving the sk_buff to the MAC hardware.
2349 * @skb: A socket buffer.
2351 static inline void skb_tx_timestamp(struct sk_buff *skb)
2353 skb_clone_tx_timestamp(skb);
2354 sw_tx_timestamp(skb);
2357 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
2358 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
2360 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
2362 return skb->ip_summed & CHECKSUM_UNNECESSARY;
2366 * skb_checksum_complete - Calculate checksum of an entire packet
2367 * @skb: packet to process
2369 * This function calculates the checksum over the entire packet plus
2370 * the value of skb->csum. The latter can be used to supply the
2371 * checksum of a pseudo header as used by TCP/UDP. It returns the
2374 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2375 * this function can be used to verify that checksum on received
2376 * packets. In that case the function should return zero if the
2377 * checksum is correct. In particular, this function will return zero
2378 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2379 * hardware has already verified the correctness of the checksum.
2381 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
2383 return skb_csum_unnecessary(skb) ?
2384 0 : __skb_checksum_complete(skb);
2387 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2388 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
2389 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
2391 if (nfct && atomic_dec_and_test(&nfct->use))
2392 nf_conntrack_destroy(nfct);
2394 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
2397 atomic_inc(&nfct->use);
2400 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2401 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
2404 atomic_inc(&skb->users);
2406 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
2412 #ifdef CONFIG_BRIDGE_NETFILTER
2413 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
2415 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
2418 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
2421 atomic_inc(&nf_bridge->use);
2423 #endif /* CONFIG_BRIDGE_NETFILTER */
2424 static inline void nf_reset(struct sk_buff *skb)
2426 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2427 nf_conntrack_put(skb->nfct);
2430 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2431 nf_conntrack_put_reasm(skb->nfct_reasm);
2432 skb->nfct_reasm = NULL;
2434 #ifdef CONFIG_BRIDGE_NETFILTER
2435 nf_bridge_put(skb->nf_bridge);
2436 skb->nf_bridge = NULL;
2440 static inline void nf_reset_trace(struct sk_buff *skb)
2442 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE)
2447 /* Note: This doesn't put any conntrack and bridge info in dst. */
2448 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2450 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2451 dst->nfct = src->nfct;
2452 nf_conntrack_get(src->nfct);
2453 dst->nfctinfo = src->nfctinfo;
2455 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2456 dst->nfct_reasm = src->nfct_reasm;
2457 nf_conntrack_get_reasm(src->nfct_reasm);
2459 #ifdef CONFIG_BRIDGE_NETFILTER
2460 dst->nf_bridge = src->nf_bridge;
2461 nf_bridge_get(src->nf_bridge);
2465 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2467 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2468 nf_conntrack_put(dst->nfct);
2470 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2471 nf_conntrack_put_reasm(dst->nfct_reasm);
2473 #ifdef CONFIG_BRIDGE_NETFILTER
2474 nf_bridge_put(dst->nf_bridge);
2476 __nf_copy(dst, src);
2479 #ifdef CONFIG_NETWORK_SECMARK
2480 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2482 to->secmark = from->secmark;
2485 static inline void skb_init_secmark(struct sk_buff *skb)
2490 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2493 static inline void skb_init_secmark(struct sk_buff *skb)
2497 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
2499 skb->queue_mapping = queue_mapping;
2502 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
2504 return skb->queue_mapping;
2507 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
2509 to->queue_mapping = from->queue_mapping;
2512 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
2514 skb->queue_mapping = rx_queue + 1;
2517 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2519 return skb->queue_mapping - 1;
2522 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2524 return skb->queue_mapping != 0;
2527 extern u16 __skb_tx_hash(const struct net_device *dev,
2528 const struct sk_buff *skb,
2529 unsigned int num_tx_queues);
2532 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2537 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2543 static inline int skb_is_gso(const struct sk_buff *skb)
2545 return skb_shinfo(skb)->gso_size;
2548 static inline int skb_is_gso_v6(const struct sk_buff *skb)
2550 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2553 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2555 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2557 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2558 * wanted then gso_type will be set. */
2559 const struct skb_shared_info *shinfo = skb_shinfo(skb);
2561 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
2562 unlikely(shinfo->gso_type == 0)) {
2563 __skb_warn_lro_forwarding(skb);
2569 static inline void skb_forward_csum(struct sk_buff *skb)
2571 /* Unfortunately we don't support this one. Any brave souls? */
2572 if (skb->ip_summed == CHECKSUM_COMPLETE)
2573 skb->ip_summed = CHECKSUM_NONE;
2577 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
2578 * @skb: skb to check
2580 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
2581 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
2582 * use this helper, to document places where we make this assertion.
2584 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
2587 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
2591 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2593 static inline bool skb_is_recycleable(const struct sk_buff *skb, int skb_size)
2595 if (irqs_disabled())
2598 if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY)
2601 if (skb_is_nonlinear(skb) || skb->fclone != SKB_FCLONE_UNAVAILABLE)
2604 skb_size = SKB_DATA_ALIGN(skb_size + NET_SKB_PAD);
2605 if (skb_end_offset(skb) < skb_size)
2608 if (skb_shared(skb) || skb_cloned(skb))
2613 #endif /* __KERNEL__ */
2614 #endif /* _LINUX_SKBUFF_H */