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 /* ensure the originating sk reference is available on driver level */
217 SKBTX_DRV_NEEDS_SK_REF = 1 << 3,
219 /* device driver supports TX zero-copy buffers */
220 SKBTX_DEV_ZEROCOPY = 1 << 4,
222 /* generate wifi status information (where possible) */
223 SKBTX_WIFI_STATUS = 1 << 5,
227 * The callback notifies userspace to release buffers when skb DMA is done in
228 * lower device, the skb last reference should be 0 when calling this.
229 * The desc is used to track userspace buffer index.
232 void (*callback)(void *);
237 /* This data is invariant across clones and lives at
238 * the end of the header data, ie. at skb->end.
240 struct skb_shared_info {
241 unsigned short nr_frags;
242 unsigned short gso_size;
243 /* Warning: this field is not always filled in (UFO)! */
244 unsigned short gso_segs;
245 unsigned short gso_type;
248 struct sk_buff *frag_list;
249 struct skb_shared_hwtstamps hwtstamps;
252 * Warning : all fields before dataref are cleared in __alloc_skb()
256 /* Intermediate layers must ensure that destructor_arg
257 * remains valid until skb destructor */
258 void * destructor_arg;
260 /* must be last field, see pskb_expand_head() */
261 skb_frag_t frags[MAX_SKB_FRAGS];
264 /* We divide dataref into two halves. The higher 16 bits hold references
265 * to the payload part of skb->data. The lower 16 bits hold references to
266 * the entire skb->data. A clone of a headerless skb holds the length of
267 * the header in skb->hdr_len.
269 * All users must obey the rule that the skb->data reference count must be
270 * greater than or equal to the payload reference count.
272 * Holding a reference to the payload part means that the user does not
273 * care about modifications to the header part of skb->data.
275 #define SKB_DATAREF_SHIFT 16
276 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
280 SKB_FCLONE_UNAVAILABLE,
286 SKB_GSO_TCPV4 = 1 << 0,
287 SKB_GSO_UDP = 1 << 1,
289 /* This indicates the skb is from an untrusted source. */
290 SKB_GSO_DODGY = 1 << 2,
292 /* This indicates the tcp segment has CWR set. */
293 SKB_GSO_TCP_ECN = 1 << 3,
295 SKB_GSO_TCPV6 = 1 << 4,
297 SKB_GSO_FCOE = 1 << 5,
300 #if BITS_PER_LONG > 32
301 #define NET_SKBUFF_DATA_USES_OFFSET 1
304 #ifdef NET_SKBUFF_DATA_USES_OFFSET
305 typedef unsigned int sk_buff_data_t;
307 typedef unsigned char *sk_buff_data_t;
310 #if defined(CONFIG_NF_DEFRAG_IPV4) || defined(CONFIG_NF_DEFRAG_IPV4_MODULE) || \
311 defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE)
312 #define NET_SKBUFF_NF_DEFRAG_NEEDED 1
316 * struct sk_buff - socket buffer
317 * @next: Next buffer in list
318 * @prev: Previous buffer in list
319 * @tstamp: Time we arrived
320 * @sk: Socket we are owned by
321 * @dev: Device we arrived on/are leaving by
322 * @cb: Control buffer. Free for use by every layer. Put private vars here
323 * @_skb_refdst: destination entry (with norefcount bit)
324 * @sp: the security path, used for xfrm
325 * @len: Length of actual data
326 * @data_len: Data length
327 * @mac_len: Length of link layer header
328 * @hdr_len: writable header length of cloned skb
329 * @csum: Checksum (must include start/offset pair)
330 * @csum_start: Offset from skb->head where checksumming should start
331 * @csum_offset: Offset from csum_start where checksum should be stored
332 * @priority: Packet queueing priority
333 * @local_df: allow local fragmentation
334 * @cloned: Head may be cloned (check refcnt to be sure)
335 * @ip_summed: Driver fed us an IP checksum
336 * @nohdr: Payload reference only, must not modify header
337 * @nfctinfo: Relationship of this skb to the connection
338 * @pkt_type: Packet class
339 * @fclone: skbuff clone status
340 * @ipvs_property: skbuff is owned by ipvs
341 * @peeked: this packet has been seen already, so stats have been
342 * done for it, don't do them again
343 * @nf_trace: netfilter packet trace flag
344 * @protocol: Packet protocol from driver
345 * @destructor: Destruct function
346 * @nfct: Associated connection, if any
347 * @nfct_reasm: netfilter conntrack re-assembly pointer
348 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
349 * @skb_iif: ifindex of device we arrived on
350 * @tc_index: Traffic control index
351 * @tc_verd: traffic control verdict
352 * @rxhash: the packet hash computed on receive
353 * @queue_mapping: Queue mapping for multiqueue devices
354 * @ndisc_nodetype: router type (from link layer)
355 * @ooo_okay: allow the mapping of a socket to a queue to be changed
356 * @l4_rxhash: indicate rxhash is a canonical 4-tuple hash over transport
358 * @wifi_acked_valid: wifi_acked was set
359 * @wifi_acked: whether frame was acked on wifi or not
360 * @dma_cookie: a cookie to one of several possible DMA operations
361 * done by skb DMA functions
362 * @secmark: security marking
363 * @mark: Generic packet mark
364 * @dropcount: total number of sk_receive_queue overflows
365 * @vlan_tci: vlan tag control information
366 * @transport_header: Transport layer header
367 * @network_header: Network layer header
368 * @mac_header: Link layer header
369 * @tail: Tail pointer
371 * @head: Head of buffer
372 * @data: Data head pointer
373 * @truesize: Buffer size
374 * @users: User count - see {datagram,tcp}.c
378 /* These two members must be first. */
379 struct sk_buff *next;
380 struct sk_buff *prev;
385 struct net_device *dev;
388 * This is the control buffer. It is free to use for every
389 * layer. Please put your private variables there. If you
390 * want to keep them across layers you have to do a skb_clone()
391 * first. This is owned by whoever has the skb queued ATM.
393 char cb[48] __aligned(8);
395 unsigned long _skb_refdst;
411 kmemcheck_bitfield_begin(flags1);
422 kmemcheck_bitfield_end(flags1);
425 void (*destructor)(struct sk_buff *skb);
426 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
427 struct nf_conntrack *nfct;
429 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
430 struct sk_buff *nfct_reasm;
432 #ifdef CONFIG_BRIDGE_NETFILTER
433 struct nf_bridge_info *nf_bridge;
437 #ifdef CONFIG_NET_SCHED
438 __u16 tc_index; /* traffic control index */
439 #ifdef CONFIG_NET_CLS_ACT
440 __u16 tc_verd; /* traffic control verdict */
447 kmemcheck_bitfield_begin(flags2);
448 #ifdef CONFIG_IPV6_NDISC_NODETYPE
449 __u8 ndisc_nodetype:2;
453 __u8 wifi_acked_valid:1;
455 /* 10/12 bit hole (depending on ndisc_nodetype presence) */
456 kmemcheck_bitfield_end(flags2);
458 #ifdef CONFIG_NET_DMA
459 dma_cookie_t dma_cookie;
461 #ifdef CONFIG_NETWORK_SECMARK
471 sk_buff_data_t transport_header;
472 sk_buff_data_t network_header;
473 sk_buff_data_t mac_header;
474 /* These elements must be at the end, see alloc_skb() for details. */
479 unsigned int truesize;
485 * Handling routines are only of interest to the kernel
487 #include <linux/slab.h>
489 #include <asm/system.h>
492 * skb might have a dst pointer attached, refcounted or not.
493 * _skb_refdst low order bit is set if refcount was _not_ taken
495 #define SKB_DST_NOREF 1UL
496 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
499 * skb_dst - returns skb dst_entry
502 * Returns skb dst_entry, regardless of reference taken or not.
504 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
506 /* If refdst was not refcounted, check we still are in a
507 * rcu_read_lock section
509 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
510 !rcu_read_lock_held() &&
511 !rcu_read_lock_bh_held());
512 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
516 * skb_dst_set - sets skb dst
520 * Sets skb dst, assuming a reference was taken on dst and should
521 * be released by skb_dst_drop()
523 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
525 skb->_skb_refdst = (unsigned long)dst;
528 extern void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst);
531 * skb_dst_is_noref - Test if skb dst isn't refcounted
534 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
536 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
539 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
541 return (struct rtable *)skb_dst(skb);
544 extern void kfree_skb(struct sk_buff *skb);
545 extern void consume_skb(struct sk_buff *skb);
546 extern void __kfree_skb(struct sk_buff *skb);
547 extern struct sk_buff *__alloc_skb(unsigned int size,
548 gfp_t priority, int fclone, int node);
549 static inline struct sk_buff *alloc_skb(unsigned int size,
552 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
555 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
558 return __alloc_skb(size, priority, 1, NUMA_NO_NODE);
561 extern void skb_recycle(struct sk_buff *skb);
562 extern bool skb_recycle_check(struct sk_buff *skb, int skb_size);
564 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
565 extern int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
566 extern struct sk_buff *skb_clone(struct sk_buff *skb,
568 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
570 extern struct sk_buff *pskb_copy(struct sk_buff *skb,
572 extern int pskb_expand_head(struct sk_buff *skb,
573 int nhead, int ntail,
575 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
576 unsigned int headroom);
577 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
578 int newheadroom, int newtailroom,
580 extern int skb_to_sgvec(struct sk_buff *skb,
581 struct scatterlist *sg, int offset,
583 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
584 struct sk_buff **trailer);
585 extern int skb_pad(struct sk_buff *skb, int pad);
586 #define dev_kfree_skb(a) consume_skb(a)
588 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
589 int getfrag(void *from, char *to, int offset,
590 int len,int odd, struct sk_buff *skb),
591 void *from, int length);
593 struct skb_seq_state {
597 __u32 stepped_offset;
598 struct sk_buff *root_skb;
599 struct sk_buff *cur_skb;
603 extern void skb_prepare_seq_read(struct sk_buff *skb,
604 unsigned int from, unsigned int to,
605 struct skb_seq_state *st);
606 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
607 struct skb_seq_state *st);
608 extern void skb_abort_seq_read(struct skb_seq_state *st);
610 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
611 unsigned int to, struct ts_config *config,
612 struct ts_state *state);
614 extern void __skb_get_rxhash(struct sk_buff *skb);
615 static inline __u32 skb_get_rxhash(struct sk_buff *skb)
618 __skb_get_rxhash(skb);
623 #ifdef NET_SKBUFF_DATA_USES_OFFSET
624 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
626 return skb->head + skb->end;
629 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
636 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
638 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
640 return &skb_shinfo(skb)->hwtstamps;
644 * skb_queue_empty - check if a queue is empty
647 * Returns true if the queue is empty, false otherwise.
649 static inline int skb_queue_empty(const struct sk_buff_head *list)
651 return list->next == (struct sk_buff *)list;
655 * skb_queue_is_last - check if skb is the last entry in the queue
659 * Returns true if @skb is the last buffer on the list.
661 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
662 const struct sk_buff *skb)
664 return skb->next == (struct sk_buff *)list;
668 * skb_queue_is_first - check if skb is the first entry in the queue
672 * Returns true if @skb is the first buffer on the list.
674 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
675 const struct sk_buff *skb)
677 return skb->prev == (struct sk_buff *)list;
681 * skb_queue_next - return the next packet in the queue
683 * @skb: current buffer
685 * Return the next packet in @list after @skb. It is only valid to
686 * call this if skb_queue_is_last() evaluates to false.
688 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
689 const struct sk_buff *skb)
691 /* This BUG_ON may seem severe, but if we just return then we
692 * are going to dereference garbage.
694 BUG_ON(skb_queue_is_last(list, skb));
699 * skb_queue_prev - return the prev packet in the queue
701 * @skb: current buffer
703 * Return the prev packet in @list before @skb. It is only valid to
704 * call this if skb_queue_is_first() evaluates to false.
706 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
707 const struct sk_buff *skb)
709 /* This BUG_ON may seem severe, but if we just return then we
710 * are going to dereference garbage.
712 BUG_ON(skb_queue_is_first(list, skb));
717 * skb_get - reference buffer
718 * @skb: buffer to reference
720 * Makes another reference to a socket buffer and returns a pointer
723 static inline struct sk_buff *skb_get(struct sk_buff *skb)
725 atomic_inc(&skb->users);
730 * If users == 1, we are the only owner and are can avoid redundant
735 * skb_cloned - is the buffer a clone
736 * @skb: buffer to check
738 * Returns true if the buffer was generated with skb_clone() and is
739 * one of multiple shared copies of the buffer. Cloned buffers are
740 * shared data so must not be written to under normal circumstances.
742 static inline int skb_cloned(const struct sk_buff *skb)
744 return skb->cloned &&
745 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
749 * skb_header_cloned - is the header a clone
750 * @skb: buffer to check
752 * Returns true if modifying the header part of the buffer requires
753 * the data to be copied.
755 static inline int skb_header_cloned(const struct sk_buff *skb)
762 dataref = atomic_read(&skb_shinfo(skb)->dataref);
763 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
768 * skb_header_release - release reference to header
769 * @skb: buffer to operate on
771 * Drop a reference to the header part of the buffer. This is done
772 * by acquiring a payload reference. You must not read from the header
773 * part of skb->data after this.
775 static inline void skb_header_release(struct sk_buff *skb)
779 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
783 * skb_shared - is the buffer shared
784 * @skb: buffer to check
786 * Returns true if more than one person has a reference to this
789 static inline int skb_shared(const struct sk_buff *skb)
791 return atomic_read(&skb->users) != 1;
795 * skb_share_check - check if buffer is shared and if so clone it
796 * @skb: buffer to check
797 * @pri: priority for memory allocation
799 * If the buffer is shared the buffer is cloned and the old copy
800 * drops a reference. A new clone with a single reference is returned.
801 * If the buffer is not shared the original buffer is returned. When
802 * being called from interrupt status or with spinlocks held pri must
805 * NULL is returned on a memory allocation failure.
807 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
810 might_sleep_if(pri & __GFP_WAIT);
811 if (skb_shared(skb)) {
812 struct sk_buff *nskb = skb_clone(skb, pri);
820 * Copy shared buffers into a new sk_buff. We effectively do COW on
821 * packets to handle cases where we have a local reader and forward
822 * and a couple of other messy ones. The normal one is tcpdumping
823 * a packet thats being forwarded.
827 * skb_unshare - make a copy of a shared buffer
828 * @skb: buffer to check
829 * @pri: priority for memory allocation
831 * If the socket buffer is a clone then this function creates a new
832 * copy of the data, drops a reference count on the old copy and returns
833 * the new copy with the reference count at 1. If the buffer is not a clone
834 * the original buffer is returned. When called with a spinlock held or
835 * from interrupt state @pri must be %GFP_ATOMIC
837 * %NULL is returned on a memory allocation failure.
839 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
842 might_sleep_if(pri & __GFP_WAIT);
843 if (skb_cloned(skb)) {
844 struct sk_buff *nskb = skb_copy(skb, pri);
845 kfree_skb(skb); /* Free our shared copy */
852 * skb_peek - peek at the head of an &sk_buff_head
853 * @list_: list to peek at
855 * Peek an &sk_buff. Unlike most other operations you _MUST_
856 * be careful with this one. A peek leaves the buffer on the
857 * list and someone else may run off with it. You must hold
858 * the appropriate locks or have a private queue to do this.
860 * Returns %NULL for an empty list or a pointer to the head element.
861 * The reference count is not incremented and the reference is therefore
862 * volatile. Use with caution.
864 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
866 struct sk_buff *list = ((const struct sk_buff *)list_)->next;
867 if (list == (struct sk_buff *)list_)
873 * skb_peek_tail - peek at the tail of an &sk_buff_head
874 * @list_: list to peek at
876 * Peek an &sk_buff. Unlike most other operations you _MUST_
877 * be careful with this one. A peek leaves the buffer on the
878 * list and someone else may run off with it. You must hold
879 * the appropriate locks or have a private queue to do this.
881 * Returns %NULL for an empty list or a pointer to the tail element.
882 * The reference count is not incremented and the reference is therefore
883 * volatile. Use with caution.
885 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
887 struct sk_buff *list = ((const struct sk_buff *)list_)->prev;
888 if (list == (struct sk_buff *)list_)
894 * skb_queue_len - get queue length
895 * @list_: list to measure
897 * Return the length of an &sk_buff queue.
899 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
905 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
906 * @list: queue to initialize
908 * This initializes only the list and queue length aspects of
909 * an sk_buff_head object. This allows to initialize the list
910 * aspects of an sk_buff_head without reinitializing things like
911 * the spinlock. It can also be used for on-stack sk_buff_head
912 * objects where the spinlock is known to not be used.
914 static inline void __skb_queue_head_init(struct sk_buff_head *list)
916 list->prev = list->next = (struct sk_buff *)list;
921 * This function creates a split out lock class for each invocation;
922 * this is needed for now since a whole lot of users of the skb-queue
923 * infrastructure in drivers have different locking usage (in hardirq)
924 * than the networking core (in softirq only). In the long run either the
925 * network layer or drivers should need annotation to consolidate the
926 * main types of usage into 3 classes.
928 static inline void skb_queue_head_init(struct sk_buff_head *list)
930 spin_lock_init(&list->lock);
931 __skb_queue_head_init(list);
934 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
935 struct lock_class_key *class)
937 skb_queue_head_init(list);
938 lockdep_set_class(&list->lock, class);
942 * Insert an sk_buff on a list.
944 * The "__skb_xxxx()" functions are the non-atomic ones that
945 * can only be called with interrupts disabled.
947 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
948 static inline void __skb_insert(struct sk_buff *newsk,
949 struct sk_buff *prev, struct sk_buff *next,
950 struct sk_buff_head *list)
954 next->prev = prev->next = newsk;
958 static inline void __skb_queue_splice(const struct sk_buff_head *list,
959 struct sk_buff *prev,
960 struct sk_buff *next)
962 struct sk_buff *first = list->next;
963 struct sk_buff *last = list->prev;
973 * skb_queue_splice - join two skb lists, this is designed for stacks
974 * @list: the new list to add
975 * @head: the place to add it in the first list
977 static inline void skb_queue_splice(const struct sk_buff_head *list,
978 struct sk_buff_head *head)
980 if (!skb_queue_empty(list)) {
981 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
982 head->qlen += list->qlen;
987 * skb_queue_splice - join two skb lists and reinitialise the emptied list
988 * @list: the new list to add
989 * @head: the place to add it in the first list
991 * The list at @list is reinitialised
993 static inline void skb_queue_splice_init(struct sk_buff_head *list,
994 struct sk_buff_head *head)
996 if (!skb_queue_empty(list)) {
997 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
998 head->qlen += list->qlen;
999 __skb_queue_head_init(list);
1004 * skb_queue_splice_tail - join two skb lists, each list being a queue
1005 * @list: the new list to add
1006 * @head: the place to add it in the first list
1008 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1009 struct sk_buff_head *head)
1011 if (!skb_queue_empty(list)) {
1012 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1013 head->qlen += list->qlen;
1018 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
1019 * @list: the new list to add
1020 * @head: the place to add it in the first list
1022 * Each of the lists is a queue.
1023 * The list at @list is reinitialised
1025 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
1026 struct sk_buff_head *head)
1028 if (!skb_queue_empty(list)) {
1029 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1030 head->qlen += list->qlen;
1031 __skb_queue_head_init(list);
1036 * __skb_queue_after - queue a buffer at the list head
1037 * @list: list to use
1038 * @prev: place after this buffer
1039 * @newsk: buffer to queue
1041 * Queue a buffer int the middle of a list. This function takes no locks
1042 * and you must therefore hold required locks before calling it.
1044 * A buffer cannot be placed on two lists at the same time.
1046 static inline void __skb_queue_after(struct sk_buff_head *list,
1047 struct sk_buff *prev,
1048 struct sk_buff *newsk)
1050 __skb_insert(newsk, prev, prev->next, list);
1053 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
1054 struct sk_buff_head *list);
1056 static inline void __skb_queue_before(struct sk_buff_head *list,
1057 struct sk_buff *next,
1058 struct sk_buff *newsk)
1060 __skb_insert(newsk, next->prev, next, list);
1064 * __skb_queue_head - queue a buffer at the list head
1065 * @list: list to use
1066 * @newsk: buffer to queue
1068 * Queue a buffer at the start 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 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
1074 static inline void __skb_queue_head(struct sk_buff_head *list,
1075 struct sk_buff *newsk)
1077 __skb_queue_after(list, (struct sk_buff *)list, newsk);
1081 * __skb_queue_tail - queue a buffer at the list tail
1082 * @list: list to use
1083 * @newsk: buffer to queue
1085 * Queue a buffer at the end of a list. This function takes no locks
1086 * and you must therefore hold required locks before calling it.
1088 * A buffer cannot be placed on two lists at the same time.
1090 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
1091 static inline void __skb_queue_tail(struct sk_buff_head *list,
1092 struct sk_buff *newsk)
1094 __skb_queue_before(list, (struct sk_buff *)list, newsk);
1098 * remove sk_buff from list. _Must_ be called atomically, and with
1101 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
1102 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
1104 struct sk_buff *next, *prev;
1109 skb->next = skb->prev = NULL;
1115 * __skb_dequeue - remove from the head of the queue
1116 * @list: list to dequeue from
1118 * Remove the head of the list. This function does not take any locks
1119 * so must be used with appropriate locks held only. The head item is
1120 * returned or %NULL if the list is empty.
1122 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1123 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1125 struct sk_buff *skb = skb_peek(list);
1127 __skb_unlink(skb, list);
1132 * __skb_dequeue_tail - remove from the tail of the queue
1133 * @list: list to dequeue from
1135 * Remove the tail of the list. This function does not take any locks
1136 * so must be used with appropriate locks held only. The tail item is
1137 * returned or %NULL if the list is empty.
1139 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1140 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1142 struct sk_buff *skb = skb_peek_tail(list);
1144 __skb_unlink(skb, list);
1149 static inline int skb_is_nonlinear(const struct sk_buff *skb)
1151 return skb->data_len;
1154 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1156 return skb->len - skb->data_len;
1159 static inline int skb_pagelen(const struct sk_buff *skb)
1163 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1164 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
1165 return len + skb_headlen(skb);
1169 * __skb_fill_page_desc - initialise a paged fragment in an skb
1170 * @skb: buffer containing fragment to be initialised
1171 * @i: paged fragment index to initialise
1172 * @page: the page to use for this fragment
1173 * @off: the offset to the data with @page
1174 * @size: the length of the data
1176 * Initialises the @i'th fragment of @skb to point to &size bytes at
1177 * offset @off within @page.
1179 * Does not take any additional reference on the fragment.
1181 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
1182 struct page *page, int off, int size)
1184 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1186 frag->page.p = page;
1187 frag->page_offset = off;
1188 skb_frag_size_set(frag, size);
1192 * skb_fill_page_desc - initialise a paged fragment in an skb
1193 * @skb: buffer containing fragment to be initialised
1194 * @i: paged fragment index to initialise
1195 * @page: the page to use for this fragment
1196 * @off: the offset to the data with @page
1197 * @size: the length of the data
1199 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1200 * @skb to point to &size bytes at offset @off within @page. In
1201 * addition updates @skb such that @i is the last fragment.
1203 * Does not take any additional reference on the fragment.
1205 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1206 struct page *page, int off, int size)
1208 __skb_fill_page_desc(skb, i, page, off, size);
1209 skb_shinfo(skb)->nr_frags = i + 1;
1212 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1215 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1216 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1217 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1219 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1220 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1222 return skb->head + skb->tail;
1225 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1227 skb->tail = skb->data - skb->head;
1230 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1232 skb_reset_tail_pointer(skb);
1233 skb->tail += offset;
1235 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1236 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1241 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1243 skb->tail = skb->data;
1246 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1248 skb->tail = skb->data + offset;
1251 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1254 * Add data to an sk_buff
1256 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1257 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1259 unsigned char *tmp = skb_tail_pointer(skb);
1260 SKB_LINEAR_ASSERT(skb);
1266 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1267 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1274 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1275 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1278 BUG_ON(skb->len < skb->data_len);
1279 return skb->data += len;
1282 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len)
1284 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
1287 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1289 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1291 if (len > skb_headlen(skb) &&
1292 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1295 return skb->data += len;
1298 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1300 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1303 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1305 if (likely(len <= skb_headlen(skb)))
1307 if (unlikely(len > skb->len))
1309 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1313 * skb_headroom - bytes at buffer head
1314 * @skb: buffer to check
1316 * Return the number of bytes of free space at the head of an &sk_buff.
1318 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1320 return skb->data - skb->head;
1324 * skb_tailroom - bytes at buffer end
1325 * @skb: buffer to check
1327 * Return the number of bytes of free space at the tail of an sk_buff
1329 static inline int skb_tailroom(const struct sk_buff *skb)
1331 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1335 * skb_reserve - adjust headroom
1336 * @skb: buffer to alter
1337 * @len: bytes to move
1339 * Increase the headroom of an empty &sk_buff by reducing the tail
1340 * room. This is only allowed for an empty buffer.
1342 static inline void skb_reserve(struct sk_buff *skb, int len)
1348 static inline void skb_reset_mac_len(struct sk_buff *skb)
1350 skb->mac_len = skb->network_header - skb->mac_header;
1353 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1354 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1356 return skb->head + skb->transport_header;
1359 static inline void skb_reset_transport_header(struct sk_buff *skb)
1361 skb->transport_header = skb->data - skb->head;
1364 static inline void skb_set_transport_header(struct sk_buff *skb,
1367 skb_reset_transport_header(skb);
1368 skb->transport_header += offset;
1371 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1373 return skb->head + skb->network_header;
1376 static inline void skb_reset_network_header(struct sk_buff *skb)
1378 skb->network_header = skb->data - skb->head;
1381 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1383 skb_reset_network_header(skb);
1384 skb->network_header += offset;
1387 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1389 return skb->head + skb->mac_header;
1392 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1394 return skb->mac_header != ~0U;
1397 static inline void skb_reset_mac_header(struct sk_buff *skb)
1399 skb->mac_header = skb->data - skb->head;
1402 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1404 skb_reset_mac_header(skb);
1405 skb->mac_header += offset;
1408 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1410 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1412 return skb->transport_header;
1415 static inline void skb_reset_transport_header(struct sk_buff *skb)
1417 skb->transport_header = skb->data;
1420 static inline void skb_set_transport_header(struct sk_buff *skb,
1423 skb->transport_header = skb->data + offset;
1426 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1428 return skb->network_header;
1431 static inline void skb_reset_network_header(struct sk_buff *skb)
1433 skb->network_header = skb->data;
1436 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1438 skb->network_header = skb->data + offset;
1441 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1443 return skb->mac_header;
1446 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1448 return skb->mac_header != NULL;
1451 static inline void skb_reset_mac_header(struct sk_buff *skb)
1453 skb->mac_header = skb->data;
1456 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1458 skb->mac_header = skb->data + offset;
1460 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1462 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
1464 return skb->csum_start - skb_headroom(skb);
1467 static inline int skb_transport_offset(const struct sk_buff *skb)
1469 return skb_transport_header(skb) - skb->data;
1472 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1474 return skb->transport_header - skb->network_header;
1477 static inline int skb_network_offset(const struct sk_buff *skb)
1479 return skb_network_header(skb) - skb->data;
1482 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
1484 return pskb_may_pull(skb, skb_network_offset(skb) + len);
1488 * CPUs often take a performance hit when accessing unaligned memory
1489 * locations. The actual performance hit varies, it can be small if the
1490 * hardware handles it or large if we have to take an exception and fix it
1493 * Since an ethernet header is 14 bytes network drivers often end up with
1494 * the IP header at an unaligned offset. The IP header can be aligned by
1495 * shifting the start of the packet by 2 bytes. Drivers should do this
1498 * skb_reserve(skb, NET_IP_ALIGN);
1500 * The downside to this alignment of the IP header is that the DMA is now
1501 * unaligned. On some architectures the cost of an unaligned DMA is high
1502 * and this cost outweighs the gains made by aligning the IP header.
1504 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1507 #ifndef NET_IP_ALIGN
1508 #define NET_IP_ALIGN 2
1512 * The networking layer reserves some headroom in skb data (via
1513 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1514 * the header has to grow. In the default case, if the header has to grow
1515 * 32 bytes or less we avoid the reallocation.
1517 * Unfortunately this headroom changes the DMA alignment of the resulting
1518 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1519 * on some architectures. An architecture can override this value,
1520 * perhaps setting it to a cacheline in size (since that will maintain
1521 * cacheline alignment of the DMA). It must be a power of 2.
1523 * Various parts of the networking layer expect at least 32 bytes of
1524 * headroom, you should not reduce this.
1526 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1527 * to reduce average number of cache lines per packet.
1528 * get_rps_cpus() for example only access one 64 bytes aligned block :
1529 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1532 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1535 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1537 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1539 if (unlikely(skb_is_nonlinear(skb))) {
1544 skb_set_tail_pointer(skb, len);
1547 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1549 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1552 return ___pskb_trim(skb, len);
1553 __skb_trim(skb, len);
1557 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1559 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1563 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1564 * @skb: buffer to alter
1567 * This is identical to pskb_trim except that the caller knows that
1568 * the skb is not cloned so we should never get an error due to out-
1571 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1573 int err = pskb_trim(skb, len);
1578 * skb_orphan - orphan a buffer
1579 * @skb: buffer to orphan
1581 * If a buffer currently has an owner then we call the owner's
1582 * destructor function and make the @skb unowned. The buffer continues
1583 * to exist but is no longer charged to its former owner.
1585 static inline void skb_orphan(struct sk_buff *skb)
1587 if (skb->destructor)
1588 skb->destructor(skb);
1589 skb->destructor = NULL;
1594 * __skb_queue_purge - empty a list
1595 * @list: list to empty
1597 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1598 * the list and one reference dropped. This function does not take the
1599 * list lock and the caller must hold the relevant locks to use it.
1601 extern void skb_queue_purge(struct sk_buff_head *list);
1602 static inline void __skb_queue_purge(struct sk_buff_head *list)
1604 struct sk_buff *skb;
1605 while ((skb = __skb_dequeue(list)) != NULL)
1610 * __dev_alloc_skb - allocate an skbuff for receiving
1611 * @length: length to allocate
1612 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1614 * Allocate a new &sk_buff and assign it a usage count of one. The
1615 * buffer has unspecified headroom built in. Users should allocate
1616 * the headroom they think they need without accounting for the
1617 * built in space. The built in space is used for optimisations.
1619 * %NULL is returned if there is no free memory.
1621 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1624 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1626 skb_reserve(skb, NET_SKB_PAD);
1630 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1632 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1633 unsigned int length, gfp_t gfp_mask);
1636 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1637 * @dev: network device to receive on
1638 * @length: length to allocate
1640 * Allocate a new &sk_buff and assign it a usage count of one. The
1641 * buffer has unspecified headroom built in. Users should allocate
1642 * the headroom they think they need without accounting for the
1643 * built in space. The built in space is used for optimisations.
1645 * %NULL is returned if there is no free memory. Although this function
1646 * allocates memory it can be called from an interrupt.
1648 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1649 unsigned int length)
1651 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1654 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
1655 unsigned int length, gfp_t gfp)
1657 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
1659 if (NET_IP_ALIGN && skb)
1660 skb_reserve(skb, NET_IP_ALIGN);
1664 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
1665 unsigned int length)
1667 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
1671 * __netdev_alloc_page - allocate a page for ps-rx on a specific device
1672 * @dev: network device to receive on
1673 * @gfp_mask: alloc_pages_node mask
1675 * Allocate a new page. dev currently unused.
1677 * %NULL is returned if there is no free memory.
1679 static inline struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask)
1681 return alloc_pages_node(NUMA_NO_NODE, gfp_mask, 0);
1685 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1686 * @dev: network device to receive on
1688 * Allocate a new page. dev currently unused.
1690 * %NULL is returned if there is no free memory.
1692 static inline struct page *netdev_alloc_page(struct net_device *dev)
1694 return __netdev_alloc_page(dev, GFP_ATOMIC);
1697 static inline void netdev_free_page(struct net_device *dev, struct page *page)
1703 * skb_frag_page - retrieve the page refered to by a paged fragment
1704 * @frag: the paged fragment
1706 * Returns the &struct page associated with @frag.
1708 static inline struct page *skb_frag_page(const skb_frag_t *frag)
1710 return frag->page.p;
1714 * __skb_frag_ref - take an addition reference on a paged fragment.
1715 * @frag: the paged fragment
1717 * Takes an additional reference on the paged fragment @frag.
1719 static inline void __skb_frag_ref(skb_frag_t *frag)
1721 get_page(skb_frag_page(frag));
1725 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
1727 * @f: the fragment offset.
1729 * Takes an additional reference on the @f'th paged fragment of @skb.
1731 static inline void skb_frag_ref(struct sk_buff *skb, int f)
1733 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
1737 * __skb_frag_unref - release a reference on a paged fragment.
1738 * @frag: the paged fragment
1740 * Releases a reference on the paged fragment @frag.
1742 static inline void __skb_frag_unref(skb_frag_t *frag)
1744 put_page(skb_frag_page(frag));
1748 * skb_frag_unref - release a reference on a paged fragment of an skb.
1750 * @f: the fragment offset
1752 * Releases a reference on the @f'th paged fragment of @skb.
1754 static inline void skb_frag_unref(struct sk_buff *skb, int f)
1756 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
1760 * skb_frag_address - gets the address of the data contained in a paged fragment
1761 * @frag: the paged fragment buffer
1763 * Returns the address of the data within @frag. The page must already
1766 static inline void *skb_frag_address(const skb_frag_t *frag)
1768 return page_address(skb_frag_page(frag)) + frag->page_offset;
1772 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
1773 * @frag: the paged fragment buffer
1775 * Returns the address of the data within @frag. Checks that the page
1776 * is mapped and returns %NULL otherwise.
1778 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
1780 void *ptr = page_address(skb_frag_page(frag));
1784 return ptr + frag->page_offset;
1788 * __skb_frag_set_page - sets the page contained in a paged fragment
1789 * @frag: the paged fragment
1790 * @page: the page to set
1792 * Sets the fragment @frag to contain @page.
1794 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
1796 frag->page.p = page;
1800 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
1802 * @f: the fragment offset
1803 * @page: the page to set
1805 * Sets the @f'th fragment of @skb to contain @page.
1807 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
1810 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
1814 * skb_frag_dma_map - maps a paged fragment via the DMA API
1815 * @dev: the device to map the fragment to
1816 * @frag: the paged fragment to map
1817 * @offset: the offset within the fragment (starting at the
1818 * fragment's own offset)
1819 * @size: the number of bytes to map
1820 * @dir: the direction of the mapping (%PCI_DMA_*)
1822 * Maps the page associated with @frag to @device.
1824 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
1825 const skb_frag_t *frag,
1826 size_t offset, size_t size,
1827 enum dma_data_direction dir)
1829 return dma_map_page(dev, skb_frag_page(frag),
1830 frag->page_offset + offset, size, dir);
1834 * skb_clone_writable - is the header of a clone writable
1835 * @skb: buffer to check
1836 * @len: length up to which to write
1838 * Returns true if modifying the header part of the cloned buffer
1839 * does not requires the data to be copied.
1841 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
1843 return !skb_header_cloned(skb) &&
1844 skb_headroom(skb) + len <= skb->hdr_len;
1847 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1852 if (headroom < NET_SKB_PAD)
1853 headroom = NET_SKB_PAD;
1854 if (headroom > skb_headroom(skb))
1855 delta = headroom - skb_headroom(skb);
1857 if (delta || cloned)
1858 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1864 * skb_cow - copy header of skb when it is required
1865 * @skb: buffer to cow
1866 * @headroom: needed headroom
1868 * If the skb passed lacks sufficient headroom or its data part
1869 * is shared, data is reallocated. If reallocation fails, an error
1870 * is returned and original skb is not changed.
1872 * The result is skb with writable area skb->head...skb->tail
1873 * and at least @headroom of space at head.
1875 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1877 return __skb_cow(skb, headroom, skb_cloned(skb));
1881 * skb_cow_head - skb_cow but only making the head writable
1882 * @skb: buffer to cow
1883 * @headroom: needed headroom
1885 * This function is identical to skb_cow except that we replace the
1886 * skb_cloned check by skb_header_cloned. It should be used when
1887 * you only need to push on some header and do not need to modify
1890 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1892 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1896 * skb_padto - pad an skbuff up to a minimal size
1897 * @skb: buffer to pad
1898 * @len: minimal length
1900 * Pads up a buffer to ensure the trailing bytes exist and are
1901 * blanked. If the buffer already contains sufficient data it
1902 * is untouched. Otherwise it is extended. Returns zero on
1903 * success. The skb is freed on error.
1906 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1908 unsigned int size = skb->len;
1909 if (likely(size >= len))
1911 return skb_pad(skb, len - size);
1914 static inline int skb_add_data(struct sk_buff *skb,
1915 char __user *from, int copy)
1917 const int off = skb->len;
1919 if (skb->ip_summed == CHECKSUM_NONE) {
1921 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1924 skb->csum = csum_block_add(skb->csum, csum, off);
1927 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1930 __skb_trim(skb, off);
1934 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
1935 const struct page *page, int off)
1938 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1940 return page == skb_frag_page(frag) &&
1941 off == frag->page_offset + skb_frag_size(frag);
1946 static inline int __skb_linearize(struct sk_buff *skb)
1948 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1952 * skb_linearize - convert paged skb to linear one
1953 * @skb: buffer to linarize
1955 * If there is no free memory -ENOMEM is returned, otherwise zero
1956 * is returned and the old skb data released.
1958 static inline int skb_linearize(struct sk_buff *skb)
1960 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1964 * skb_linearize_cow - make sure skb is linear and writable
1965 * @skb: buffer to process
1967 * If there is no free memory -ENOMEM is returned, otherwise zero
1968 * is returned and the old skb data released.
1970 static inline int skb_linearize_cow(struct sk_buff *skb)
1972 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
1973 __skb_linearize(skb) : 0;
1977 * skb_postpull_rcsum - update checksum for received skb after pull
1978 * @skb: buffer to update
1979 * @start: start of data before pull
1980 * @len: length of data pulled
1982 * After doing a pull on a received packet, you need to call this to
1983 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1984 * CHECKSUM_NONE so that it can be recomputed from scratch.
1987 static inline void skb_postpull_rcsum(struct sk_buff *skb,
1988 const void *start, unsigned int len)
1990 if (skb->ip_summed == CHECKSUM_COMPLETE)
1991 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
1994 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
1997 * pskb_trim_rcsum - trim received skb and update checksum
1998 * @skb: buffer to trim
2001 * This is exactly the same as pskb_trim except that it ensures the
2002 * checksum of received packets are still valid after the operation.
2005 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
2007 if (likely(len >= skb->len))
2009 if (skb->ip_summed == CHECKSUM_COMPLETE)
2010 skb->ip_summed = CHECKSUM_NONE;
2011 return __pskb_trim(skb, len);
2014 #define skb_queue_walk(queue, skb) \
2015 for (skb = (queue)->next; \
2016 skb != (struct sk_buff *)(queue); \
2019 #define skb_queue_walk_safe(queue, skb, tmp) \
2020 for (skb = (queue)->next, tmp = skb->next; \
2021 skb != (struct sk_buff *)(queue); \
2022 skb = tmp, tmp = skb->next)
2024 #define skb_queue_walk_from(queue, skb) \
2025 for (; skb != (struct sk_buff *)(queue); \
2028 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2029 for (tmp = skb->next; \
2030 skb != (struct sk_buff *)(queue); \
2031 skb = tmp, tmp = skb->next)
2033 #define skb_queue_reverse_walk(queue, skb) \
2034 for (skb = (queue)->prev; \
2035 skb != (struct sk_buff *)(queue); \
2038 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2039 for (skb = (queue)->prev, tmp = skb->prev; \
2040 skb != (struct sk_buff *)(queue); \
2041 skb = tmp, tmp = skb->prev)
2043 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2044 for (tmp = skb->prev; \
2045 skb != (struct sk_buff *)(queue); \
2046 skb = tmp, tmp = skb->prev)
2048 static inline bool skb_has_frag_list(const struct sk_buff *skb)
2050 return skb_shinfo(skb)->frag_list != NULL;
2053 static inline void skb_frag_list_init(struct sk_buff *skb)
2055 skb_shinfo(skb)->frag_list = NULL;
2058 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
2060 frag->next = skb_shinfo(skb)->frag_list;
2061 skb_shinfo(skb)->frag_list = frag;
2064 #define skb_walk_frags(skb, iter) \
2065 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2067 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
2068 int *peeked, int *err);
2069 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
2070 int noblock, int *err);
2071 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
2072 struct poll_table_struct *wait);
2073 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
2074 int offset, struct iovec *to,
2076 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
2079 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
2081 const struct iovec *from,
2084 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from,
2086 const struct iovec *to,
2089 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
2090 extern void skb_free_datagram_locked(struct sock *sk,
2091 struct sk_buff *skb);
2092 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
2093 unsigned int flags);
2094 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
2095 int len, __wsum csum);
2096 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
2098 extern int skb_store_bits(struct sk_buff *skb, int offset,
2099 const void *from, int len);
2100 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
2101 int offset, u8 *to, int len,
2103 extern int skb_splice_bits(struct sk_buff *skb,
2104 unsigned int offset,
2105 struct pipe_inode_info *pipe,
2107 unsigned int flags);
2108 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
2109 extern void skb_split(struct sk_buff *skb,
2110 struct sk_buff *skb1, const u32 len);
2111 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
2114 extern struct sk_buff *skb_segment(struct sk_buff *skb, u32 features);
2116 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
2117 int len, void *buffer)
2119 int hlen = skb_headlen(skb);
2121 if (hlen - offset >= len)
2122 return skb->data + offset;
2124 if (skb_copy_bits(skb, offset, buffer, len) < 0)
2130 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
2132 const unsigned int len)
2134 memcpy(to, skb->data, len);
2137 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
2138 const int offset, void *to,
2139 const unsigned int len)
2141 memcpy(to, skb->data + offset, len);
2144 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
2146 const unsigned int len)
2148 memcpy(skb->data, from, len);
2151 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
2154 const unsigned int len)
2156 memcpy(skb->data + offset, from, len);
2159 extern void skb_init(void);
2161 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
2167 * skb_get_timestamp - get timestamp from a skb
2168 * @skb: skb to get stamp from
2169 * @stamp: pointer to struct timeval to store stamp in
2171 * Timestamps are stored in the skb as offsets to a base timestamp.
2172 * This function converts the offset back to a struct timeval and stores
2175 static inline void skb_get_timestamp(const struct sk_buff *skb,
2176 struct timeval *stamp)
2178 *stamp = ktime_to_timeval(skb->tstamp);
2181 static inline void skb_get_timestampns(const struct sk_buff *skb,
2182 struct timespec *stamp)
2184 *stamp = ktime_to_timespec(skb->tstamp);
2187 static inline void __net_timestamp(struct sk_buff *skb)
2189 skb->tstamp = ktime_get_real();
2192 static inline ktime_t net_timedelta(ktime_t t)
2194 return ktime_sub(ktime_get_real(), t);
2197 static inline ktime_t net_invalid_timestamp(void)
2199 return ktime_set(0, 0);
2202 extern void skb_timestamping_init(void);
2204 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2206 extern void skb_clone_tx_timestamp(struct sk_buff *skb);
2207 extern bool skb_defer_rx_timestamp(struct sk_buff *skb);
2209 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2211 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
2215 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
2220 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2223 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2225 * PHY drivers may accept clones of transmitted packets for
2226 * timestamping via their phy_driver.txtstamp method. These drivers
2227 * must call this function to return the skb back to the stack, with
2228 * or without a timestamp.
2230 * @skb: clone of the the original outgoing packet
2231 * @hwtstamps: hardware time stamps, may be NULL if not available
2234 void skb_complete_tx_timestamp(struct sk_buff *skb,
2235 struct skb_shared_hwtstamps *hwtstamps);
2238 * skb_tstamp_tx - queue clone of skb with send time stamps
2239 * @orig_skb: the original outgoing packet
2240 * @hwtstamps: hardware time stamps, may be NULL if not available
2242 * If the skb has a socket associated, then this function clones the
2243 * skb (thus sharing the actual data and optional structures), stores
2244 * the optional hardware time stamping information (if non NULL) or
2245 * generates a software time stamp (otherwise), then queues the clone
2246 * to the error queue of the socket. Errors are silently ignored.
2248 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
2249 struct skb_shared_hwtstamps *hwtstamps);
2251 static inline void sw_tx_timestamp(struct sk_buff *skb)
2253 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP &&
2254 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
2255 skb_tstamp_tx(skb, NULL);
2259 * skb_tx_timestamp() - Driver hook for transmit timestamping
2261 * Ethernet MAC Drivers should call this function in their hard_xmit()
2262 * function immediately before giving the sk_buff to the MAC hardware.
2264 * @skb: A socket buffer.
2266 static inline void skb_tx_timestamp(struct sk_buff *skb)
2268 skb_clone_tx_timestamp(skb);
2269 sw_tx_timestamp(skb);
2273 * skb_complete_wifi_ack - deliver skb with wifi status
2275 * @skb: the original outgoing packet
2276 * @acked: ack status
2279 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
2281 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
2282 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
2284 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
2286 return skb->ip_summed & CHECKSUM_UNNECESSARY;
2290 * skb_checksum_complete - Calculate checksum of an entire packet
2291 * @skb: packet to process
2293 * This function calculates the checksum over the entire packet plus
2294 * the value of skb->csum. The latter can be used to supply the
2295 * checksum of a pseudo header as used by TCP/UDP. It returns the
2298 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2299 * this function can be used to verify that checksum on received
2300 * packets. In that case the function should return zero if the
2301 * checksum is correct. In particular, this function will return zero
2302 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2303 * hardware has already verified the correctness of the checksum.
2305 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
2307 return skb_csum_unnecessary(skb) ?
2308 0 : __skb_checksum_complete(skb);
2311 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2312 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
2313 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
2315 if (nfct && atomic_dec_and_test(&nfct->use))
2316 nf_conntrack_destroy(nfct);
2318 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
2321 atomic_inc(&nfct->use);
2324 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2325 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
2328 atomic_inc(&skb->users);
2330 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
2336 #ifdef CONFIG_BRIDGE_NETFILTER
2337 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
2339 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
2342 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
2345 atomic_inc(&nf_bridge->use);
2347 #endif /* CONFIG_BRIDGE_NETFILTER */
2348 static inline void nf_reset(struct sk_buff *skb)
2350 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2351 nf_conntrack_put(skb->nfct);
2354 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2355 nf_conntrack_put_reasm(skb->nfct_reasm);
2356 skb->nfct_reasm = NULL;
2358 #ifdef CONFIG_BRIDGE_NETFILTER
2359 nf_bridge_put(skb->nf_bridge);
2360 skb->nf_bridge = NULL;
2364 /* Note: This doesn't put any conntrack and bridge info in dst. */
2365 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2367 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2368 dst->nfct = src->nfct;
2369 nf_conntrack_get(src->nfct);
2370 dst->nfctinfo = src->nfctinfo;
2372 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2373 dst->nfct_reasm = src->nfct_reasm;
2374 nf_conntrack_get_reasm(src->nfct_reasm);
2376 #ifdef CONFIG_BRIDGE_NETFILTER
2377 dst->nf_bridge = src->nf_bridge;
2378 nf_bridge_get(src->nf_bridge);
2382 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2384 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2385 nf_conntrack_put(dst->nfct);
2387 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2388 nf_conntrack_put_reasm(dst->nfct_reasm);
2390 #ifdef CONFIG_BRIDGE_NETFILTER
2391 nf_bridge_put(dst->nf_bridge);
2393 __nf_copy(dst, src);
2396 #ifdef CONFIG_NETWORK_SECMARK
2397 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2399 to->secmark = from->secmark;
2402 static inline void skb_init_secmark(struct sk_buff *skb)
2407 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2410 static inline void skb_init_secmark(struct sk_buff *skb)
2414 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
2416 skb->queue_mapping = queue_mapping;
2419 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
2421 return skb->queue_mapping;
2424 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
2426 to->queue_mapping = from->queue_mapping;
2429 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
2431 skb->queue_mapping = rx_queue + 1;
2434 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2436 return skb->queue_mapping - 1;
2439 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2441 return skb->queue_mapping != 0;
2444 extern u16 __skb_tx_hash(const struct net_device *dev,
2445 const struct sk_buff *skb,
2446 unsigned int num_tx_queues);
2449 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2454 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2460 static inline int skb_is_gso(const struct sk_buff *skb)
2462 return skb_shinfo(skb)->gso_size;
2465 static inline int skb_is_gso_v6(const struct sk_buff *skb)
2467 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2470 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2472 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2474 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2475 * wanted then gso_type will be set. */
2476 const struct skb_shared_info *shinfo = skb_shinfo(skb);
2478 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
2479 unlikely(shinfo->gso_type == 0)) {
2480 __skb_warn_lro_forwarding(skb);
2486 static inline void skb_forward_csum(struct sk_buff *skb)
2488 /* Unfortunately we don't support this one. Any brave souls? */
2489 if (skb->ip_summed == CHECKSUM_COMPLETE)
2490 skb->ip_summed = CHECKSUM_NONE;
2494 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
2495 * @skb: skb to check
2497 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
2498 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
2499 * use this helper, to document places where we make this assertion.
2501 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
2504 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
2508 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2510 static inline bool skb_is_recycleable(const struct sk_buff *skb, int skb_size)
2512 if (irqs_disabled())
2515 if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY)
2518 if (skb_is_nonlinear(skb) || skb->fclone != SKB_FCLONE_UNAVAILABLE)
2521 skb_size = SKB_DATA_ALIGN(skb_size + NET_SKB_PAD);
2522 if (skb_end_pointer(skb) - skb->head < skb_size)
2525 if (skb_shared(skb) || skb_cloned(skb))
2530 #endif /* __KERNEL__ */
2531 #endif /* _LINUX_SKBUFF_H */