2 * Definitions for the 'struct sk_buff' memory handlers.
5 * Alan Cox, <gw4pts@gw4pts.ampr.org>
6 * Florian La Roche, <rzsfl@rz.uni-sb.de>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #ifndef _LINUX_SKBUFF_H
15 #define _LINUX_SKBUFF_H
17 #include <linux/kernel.h>
18 #include <linux/kmemcheck.h>
19 #include <linux/compiler.h>
20 #include <linux/time.h>
21 #include <linux/bug.h>
22 #include <linux/cache.h>
24 #include <linux/atomic.h>
25 #include <asm/types.h>
26 #include <linux/spinlock.h>
27 #include <linux/net.h>
28 #include <linux/textsearch.h>
29 #include <net/checksum.h>
30 #include <linux/rcupdate.h>
31 #include <linux/dmaengine.h>
32 #include <linux/hrtimer.h>
33 #include <linux/dma-mapping.h>
34 #include <linux/netdev_features.h>
36 /* Don't change this without changing skb_csum_unnecessary! */
37 #define CHECKSUM_NONE 0
38 #define CHECKSUM_UNNECESSARY 1
39 #define CHECKSUM_COMPLETE 2
40 #define CHECKSUM_PARTIAL 3
42 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
43 ~(SMP_CACHE_BYTES - 1))
44 #define SKB_WITH_OVERHEAD(X) \
45 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
46 #define SKB_MAX_ORDER(X, ORDER) \
47 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
48 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
49 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
51 /* return minimum truesize of one skb containing X bytes of data */
52 #define SKB_TRUESIZE(X) ((X) + \
53 SKB_DATA_ALIGN(sizeof(struct sk_buff)) + \
54 SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
56 /* A. Checksumming of received packets by device.
58 * NONE: device failed to checksum this packet.
59 * skb->csum is undefined.
61 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
62 * skb->csum is undefined.
63 * It is bad option, but, unfortunately, many of vendors do this.
64 * Apparently with secret goal to sell you new device, when you
65 * will add new protocol to your host. F.e. IPv6. 8)
67 * COMPLETE: the most generic way. Device supplied checksum of _all_
68 * the packet as seen by netif_rx in skb->csum.
69 * NOTE: Even if device supports only some protocols, but
70 * is able to produce some skb->csum, it MUST use COMPLETE,
73 * PARTIAL: identical to the case for output below. This may occur
74 * on a packet received directly from another Linux OS, e.g.,
75 * a virtualised Linux kernel on the same host. The packet can
76 * be treated in the same way as UNNECESSARY except that on
77 * output (i.e., forwarding) the checksum must be filled in
78 * by the OS or the hardware.
80 * B. Checksumming on output.
82 * NONE: skb is checksummed by protocol or csum is not required.
84 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
85 * from skb->csum_start to the end and to record the checksum
86 * at skb->csum_start + skb->csum_offset.
88 * Device must show its capabilities in dev->features, set
89 * at device setup time.
90 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
92 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
93 * TCP/UDP over IPv4. Sigh. Vendors like this
94 * way by an unknown reason. Though, see comment above
95 * about CHECKSUM_UNNECESSARY. 8)
96 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
98 * UNNECESSARY: device will do per protocol specific csum. Protocol drivers
99 * that do not want net to perform the checksum calculation should use
100 * this flag in their outgoing skbs.
101 * NETIF_F_FCOE_CRC this indicates the device can do FCoE FC CRC
102 * offload. Correspondingly, the FCoE protocol driver
103 * stack should use CHECKSUM_UNNECESSARY.
105 * Any questions? No questions, good. --ANK
110 struct pipe_inode_info;
112 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
113 struct nf_conntrack {
118 #ifdef CONFIG_BRIDGE_NETFILTER
119 struct nf_bridge_info {
121 struct net_device *physindev;
122 struct net_device *physoutdev;
124 unsigned long data[32 / sizeof(unsigned long)];
128 struct sk_buff_head {
129 /* These two members must be first. */
130 struct sk_buff *next;
131 struct sk_buff *prev;
139 /* To allow 64K frame to be packed as single skb without frag_list we
140 * require 64K/PAGE_SIZE pages plus 1 additional page to allow for
141 * buffers which do not start on a page boundary.
143 * Since GRO uses frags we allocate at least 16 regardless of page
146 #if (65536/PAGE_SIZE + 1) < 16
147 #define MAX_SKB_FRAGS 16UL
149 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1)
152 typedef struct skb_frag_struct skb_frag_t;
154 struct skb_frag_struct {
158 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
167 static inline unsigned int skb_frag_size(const skb_frag_t *frag)
172 static inline void skb_frag_size_set(skb_frag_t *frag, unsigned int size)
177 static inline void skb_frag_size_add(skb_frag_t *frag, int delta)
182 static inline void skb_frag_size_sub(skb_frag_t *frag, int delta)
187 #define HAVE_HW_TIME_STAMP
190 * struct skb_shared_hwtstamps - hardware time stamps
191 * @hwtstamp: hardware time stamp transformed into duration
192 * since arbitrary point in time
193 * @syststamp: hwtstamp transformed to system time base
195 * Software time stamps generated by ktime_get_real() are stored in
196 * skb->tstamp. The relation between the different kinds of time
197 * stamps is as follows:
199 * syststamp and tstamp can be compared against each other in
200 * arbitrary combinations. The accuracy of a
201 * syststamp/tstamp/"syststamp from other device" comparison is
202 * limited by the accuracy of the transformation into system time
203 * base. This depends on the device driver and its underlying
206 * hwtstamps can only be compared against other hwtstamps from
209 * This structure is attached to packets as part of the
210 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
212 struct skb_shared_hwtstamps {
217 /* Definitions for tx_flags in struct skb_shared_info */
219 /* generate hardware time stamp */
220 SKBTX_HW_TSTAMP = 1 << 0,
222 /* generate software time stamp */
223 SKBTX_SW_TSTAMP = 1 << 1,
225 /* device driver is going to provide hardware time stamp */
226 SKBTX_IN_PROGRESS = 1 << 2,
228 /* ensure the originating sk reference is available on driver level */
229 SKBTX_DRV_NEEDS_SK_REF = 1 << 3,
231 /* device driver supports TX zero-copy buffers */
232 SKBTX_DEV_ZEROCOPY = 1 << 4,
234 /* generate wifi status information (where possible) */
235 SKBTX_WIFI_STATUS = 1 << 5,
239 * The callback notifies userspace to release buffers when skb DMA is done in
240 * lower device, the skb last reference should be 0 when calling this.
241 * The desc is used to track userspace buffer index.
244 void (*callback)(void *);
249 /* This data is invariant across clones and lives at
250 * the end of the header data, ie. at skb->end.
252 struct skb_shared_info {
253 unsigned char nr_frags;
255 unsigned short gso_size;
256 /* Warning: this field is not always filled in (UFO)! */
257 unsigned short gso_segs;
258 unsigned short gso_type;
259 struct sk_buff *frag_list;
260 struct skb_shared_hwtstamps hwtstamps;
264 * Warning : all fields before dataref are cleared in __alloc_skb()
268 /* Intermediate layers must ensure that destructor_arg
269 * remains valid until skb destructor */
270 void * destructor_arg;
272 /* must be last field, see pskb_expand_head() */
273 skb_frag_t frags[MAX_SKB_FRAGS];
276 /* We divide dataref into two halves. The higher 16 bits hold references
277 * to the payload part of skb->data. The lower 16 bits hold references to
278 * the entire skb->data. A clone of a headerless skb holds the length of
279 * the header in skb->hdr_len.
281 * All users must obey the rule that the skb->data reference count must be
282 * greater than or equal to the payload reference count.
284 * Holding a reference to the payload part means that the user does not
285 * care about modifications to the header part of skb->data.
287 #define SKB_DATAREF_SHIFT 16
288 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
292 SKB_FCLONE_UNAVAILABLE,
298 SKB_GSO_TCPV4 = 1 << 0,
299 SKB_GSO_UDP = 1 << 1,
301 /* This indicates the skb is from an untrusted source. */
302 SKB_GSO_DODGY = 1 << 2,
304 /* This indicates the tcp segment has CWR set. */
305 SKB_GSO_TCP_ECN = 1 << 3,
307 SKB_GSO_TCPV6 = 1 << 4,
309 SKB_GSO_FCOE = 1 << 5,
312 #if BITS_PER_LONG > 32
313 #define NET_SKBUFF_DATA_USES_OFFSET 1
316 #ifdef NET_SKBUFF_DATA_USES_OFFSET
317 typedef unsigned int sk_buff_data_t;
319 typedef unsigned char *sk_buff_data_t;
322 #if defined(CONFIG_NF_DEFRAG_IPV4) || defined(CONFIG_NF_DEFRAG_IPV4_MODULE) || \
323 defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE)
324 #define NET_SKBUFF_NF_DEFRAG_NEEDED 1
328 * struct sk_buff - socket buffer
329 * @next: Next buffer in list
330 * @prev: Previous buffer in list
331 * @tstamp: Time we arrived
332 * @sk: Socket we are owned by
333 * @dev: Device we arrived on/are leaving by
334 * @cb: Control buffer. Free for use by every layer. Put private vars here
335 * @_skb_refdst: destination entry (with norefcount bit)
336 * @sp: the security path, used for xfrm
337 * @len: Length of actual data
338 * @data_len: Data length
339 * @mac_len: Length of link layer header
340 * @hdr_len: writable header length of cloned skb
341 * @csum: Checksum (must include start/offset pair)
342 * @csum_start: Offset from skb->head where checksumming should start
343 * @csum_offset: Offset from csum_start where checksum should be stored
344 * @priority: Packet queueing priority
345 * @local_df: allow local fragmentation
346 * @cloned: Head may be cloned (check refcnt to be sure)
347 * @ip_summed: Driver fed us an IP checksum
348 * @nohdr: Payload reference only, must not modify header
349 * @nfctinfo: Relationship of this skb to the connection
350 * @pkt_type: Packet class
351 * @fclone: skbuff clone status
352 * @ipvs_property: skbuff is owned by ipvs
353 * @peeked: this packet has been seen already, so stats have been
354 * done for it, don't do them again
355 * @nf_trace: netfilter packet trace flag
356 * @protocol: Packet protocol from driver
357 * @destructor: Destruct function
358 * @nfct: Associated connection, if any
359 * @nfct_reasm: netfilter conntrack re-assembly pointer
360 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
361 * @skb_iif: ifindex of device we arrived on
362 * @tc_index: Traffic control index
363 * @tc_verd: traffic control verdict
364 * @rxhash: the packet hash computed on receive
365 * @queue_mapping: Queue mapping for multiqueue devices
366 * @ndisc_nodetype: router type (from link layer)
367 * @ooo_okay: allow the mapping of a socket to a queue to be changed
368 * @l4_rxhash: indicate rxhash is a canonical 4-tuple hash over transport
370 * @wifi_acked_valid: wifi_acked was set
371 * @wifi_acked: whether frame was acked on wifi or not
372 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
373 * @dma_cookie: a cookie to one of several possible DMA operations
374 * done by skb DMA functions
375 * @secmark: security marking
376 * @mark: Generic packet mark
377 * @dropcount: total number of sk_receive_queue overflows
378 * @vlan_tci: vlan tag control information
379 * @transport_header: Transport layer header
380 * @network_header: Network layer header
381 * @mac_header: Link layer header
382 * @tail: Tail pointer
384 * @head: Head of buffer
385 * @data: Data head pointer
386 * @truesize: Buffer size
387 * @users: User count - see {datagram,tcp}.c
391 /* These two members must be first. */
392 struct sk_buff *next;
393 struct sk_buff *prev;
398 struct net_device *dev;
401 * This is the control buffer. It is free to use for every
402 * layer. Please put your private variables there. If you
403 * want to keep them across layers you have to do a skb_clone()
404 * first. This is owned by whoever has the skb queued ATM.
406 char cb[48] __aligned(8);
408 unsigned long _skb_refdst;
424 kmemcheck_bitfield_begin(flags1);
435 kmemcheck_bitfield_end(flags1);
438 void (*destructor)(struct sk_buff *skb);
439 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
440 struct nf_conntrack *nfct;
442 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
443 struct sk_buff *nfct_reasm;
445 #ifdef CONFIG_BRIDGE_NETFILTER
446 struct nf_bridge_info *nf_bridge;
455 #ifdef CONFIG_NET_SCHED
456 __u16 tc_index; /* traffic control index */
457 #ifdef CONFIG_NET_CLS_ACT
458 __u16 tc_verd; /* traffic control verdict */
463 kmemcheck_bitfield_begin(flags2);
464 #ifdef CONFIG_IPV6_NDISC_NODETYPE
465 __u8 ndisc_nodetype:2;
469 __u8 wifi_acked_valid:1;
472 /* 9/11 bit hole (depending on ndisc_nodetype presence) */
473 kmemcheck_bitfield_end(flags2);
475 #ifdef CONFIG_NET_DMA
476 dma_cookie_t dma_cookie;
478 #ifdef CONFIG_NETWORK_SECMARK
487 sk_buff_data_t transport_header;
488 sk_buff_data_t network_header;
489 sk_buff_data_t mac_header;
490 /* These elements must be at the end, see alloc_skb() for details. */
495 unsigned int truesize;
501 * Handling routines are only of interest to the kernel
503 #include <linux/slab.h>
507 * skb might have a dst pointer attached, refcounted or not.
508 * _skb_refdst low order bit is set if refcount was _not_ taken
510 #define SKB_DST_NOREF 1UL
511 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
514 * skb_dst - returns skb dst_entry
517 * Returns skb dst_entry, regardless of reference taken or not.
519 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
521 /* If refdst was not refcounted, check we still are in a
522 * rcu_read_lock section
524 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
525 !rcu_read_lock_held() &&
526 !rcu_read_lock_bh_held());
527 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
531 * skb_dst_set - sets skb dst
535 * Sets skb dst, assuming a reference was taken on dst and should
536 * be released by skb_dst_drop()
538 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
540 skb->_skb_refdst = (unsigned long)dst;
543 extern void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst);
546 * skb_dst_is_noref - Test if skb dst isn't refcounted
549 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
551 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
554 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
556 return (struct rtable *)skb_dst(skb);
559 extern void kfree_skb(struct sk_buff *skb);
560 extern void consume_skb(struct sk_buff *skb);
561 extern void __kfree_skb(struct sk_buff *skb);
562 extern struct sk_buff *__alloc_skb(unsigned int size,
563 gfp_t priority, int fclone, int node);
564 extern struct sk_buff *build_skb(void *data);
565 static inline struct sk_buff *alloc_skb(unsigned int size,
568 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
571 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
574 return __alloc_skb(size, priority, 1, NUMA_NO_NODE);
577 extern void skb_recycle(struct sk_buff *skb);
578 extern bool skb_recycle_check(struct sk_buff *skb, int skb_size);
580 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
581 extern int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
582 extern struct sk_buff *skb_clone(struct sk_buff *skb,
584 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
586 extern struct sk_buff *__pskb_copy(struct sk_buff *skb,
587 int headroom, gfp_t gfp_mask);
589 extern int pskb_expand_head(struct sk_buff *skb,
590 int nhead, int ntail,
592 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
593 unsigned int headroom);
594 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
595 int newheadroom, int newtailroom,
597 extern int skb_to_sgvec(struct sk_buff *skb,
598 struct scatterlist *sg, int offset,
600 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
601 struct sk_buff **trailer);
602 extern int skb_pad(struct sk_buff *skb, int pad);
603 #define dev_kfree_skb(a) consume_skb(a)
605 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
606 int getfrag(void *from, char *to, int offset,
607 int len,int odd, struct sk_buff *skb),
608 void *from, int length);
610 struct skb_seq_state {
614 __u32 stepped_offset;
615 struct sk_buff *root_skb;
616 struct sk_buff *cur_skb;
620 extern void skb_prepare_seq_read(struct sk_buff *skb,
621 unsigned int from, unsigned int to,
622 struct skb_seq_state *st);
623 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
624 struct skb_seq_state *st);
625 extern void skb_abort_seq_read(struct skb_seq_state *st);
627 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
628 unsigned int to, struct ts_config *config,
629 struct ts_state *state);
631 extern void __skb_get_rxhash(struct sk_buff *skb);
632 static inline __u32 skb_get_rxhash(struct sk_buff *skb)
635 __skb_get_rxhash(skb);
640 #ifdef NET_SKBUFF_DATA_USES_OFFSET
641 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
643 return skb->head + skb->end;
646 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
653 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
655 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
657 return &skb_shinfo(skb)->hwtstamps;
661 * skb_queue_empty - check if a queue is empty
664 * Returns true if the queue is empty, false otherwise.
666 static inline int skb_queue_empty(const struct sk_buff_head *list)
668 return list->next == (struct sk_buff *)list;
672 * skb_queue_is_last - check if skb is the last entry in the queue
676 * Returns true if @skb is the last buffer on the list.
678 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
679 const struct sk_buff *skb)
681 return skb->next == (struct sk_buff *)list;
685 * skb_queue_is_first - check if skb is the first entry in the queue
689 * Returns true if @skb is the first buffer on the list.
691 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
692 const struct sk_buff *skb)
694 return skb->prev == (struct sk_buff *)list;
698 * skb_queue_next - return the next packet in the queue
700 * @skb: current buffer
702 * Return the next packet in @list after @skb. It is only valid to
703 * call this if skb_queue_is_last() evaluates to false.
705 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
706 const struct sk_buff *skb)
708 /* This BUG_ON may seem severe, but if we just return then we
709 * are going to dereference garbage.
711 BUG_ON(skb_queue_is_last(list, skb));
716 * skb_queue_prev - return the prev packet in the queue
718 * @skb: current buffer
720 * Return the prev packet in @list before @skb. It is only valid to
721 * call this if skb_queue_is_first() evaluates to false.
723 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
724 const struct sk_buff *skb)
726 /* This BUG_ON may seem severe, but if we just return then we
727 * are going to dereference garbage.
729 BUG_ON(skb_queue_is_first(list, skb));
734 * skb_get - reference buffer
735 * @skb: buffer to reference
737 * Makes another reference to a socket buffer and returns a pointer
740 static inline struct sk_buff *skb_get(struct sk_buff *skb)
742 atomic_inc(&skb->users);
747 * If users == 1, we are the only owner and are can avoid redundant
752 * skb_cloned - is the buffer a clone
753 * @skb: buffer to check
755 * Returns true if the buffer was generated with skb_clone() and is
756 * one of multiple shared copies of the buffer. Cloned buffers are
757 * shared data so must not be written to under normal circumstances.
759 static inline int skb_cloned(const struct sk_buff *skb)
761 return skb->cloned &&
762 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
766 * skb_header_cloned - is the header a clone
767 * @skb: buffer to check
769 * Returns true if modifying the header part of the buffer requires
770 * the data to be copied.
772 static inline int skb_header_cloned(const struct sk_buff *skb)
779 dataref = atomic_read(&skb_shinfo(skb)->dataref);
780 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
785 * skb_header_release - release reference to header
786 * @skb: buffer to operate on
788 * Drop a reference to the header part of the buffer. This is done
789 * by acquiring a payload reference. You must not read from the header
790 * part of skb->data after this.
792 static inline void skb_header_release(struct sk_buff *skb)
796 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
800 * skb_shared - is the buffer shared
801 * @skb: buffer to check
803 * Returns true if more than one person has a reference to this
806 static inline int skb_shared(const struct sk_buff *skb)
808 return atomic_read(&skb->users) != 1;
812 * skb_share_check - check if buffer is shared and if so clone it
813 * @skb: buffer to check
814 * @pri: priority for memory allocation
816 * If the buffer is shared the buffer is cloned and the old copy
817 * drops a reference. A new clone with a single reference is returned.
818 * If the buffer is not shared the original buffer is returned. When
819 * being called from interrupt status or with spinlocks held pri must
822 * NULL is returned on a memory allocation failure.
824 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
827 might_sleep_if(pri & __GFP_WAIT);
828 if (skb_shared(skb)) {
829 struct sk_buff *nskb = skb_clone(skb, pri);
837 * Copy shared buffers into a new sk_buff. We effectively do COW on
838 * packets to handle cases where we have a local reader and forward
839 * and a couple of other messy ones. The normal one is tcpdumping
840 * a packet thats being forwarded.
844 * skb_unshare - make a copy of a shared buffer
845 * @skb: buffer to check
846 * @pri: priority for memory allocation
848 * If the socket buffer is a clone then this function creates a new
849 * copy of the data, drops a reference count on the old copy and returns
850 * the new copy with the reference count at 1. If the buffer is not a clone
851 * the original buffer is returned. When called with a spinlock held or
852 * from interrupt state @pri must be %GFP_ATOMIC
854 * %NULL is returned on a memory allocation failure.
856 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
859 might_sleep_if(pri & __GFP_WAIT);
860 if (skb_cloned(skb)) {
861 struct sk_buff *nskb = skb_copy(skb, pri);
862 kfree_skb(skb); /* Free our shared copy */
869 * skb_peek - peek at the head of an &sk_buff_head
870 * @list_: list to peek at
872 * Peek an &sk_buff. Unlike most other operations you _MUST_
873 * be careful with this one. A peek leaves the buffer on the
874 * list and someone else may run off with it. You must hold
875 * the appropriate locks or have a private queue to do this.
877 * Returns %NULL for an empty list or a pointer to the head element.
878 * The reference count is not incremented and the reference is therefore
879 * volatile. Use with caution.
881 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
883 struct sk_buff *list = ((const struct sk_buff *)list_)->next;
884 if (list == (struct sk_buff *)list_)
890 * skb_peek_next - peek skb following the given one from a queue
891 * @skb: skb to start from
892 * @list_: list to peek at
894 * Returns %NULL when the end of the list is met or a pointer to the
895 * next element. The reference count is not incremented and the
896 * reference is therefore volatile. Use with caution.
898 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
899 const struct sk_buff_head *list_)
901 struct sk_buff *next = skb->next;
902 if (next == (struct sk_buff *)list_)
908 * skb_peek_tail - peek at the tail of an &sk_buff_head
909 * @list_: list to peek at
911 * Peek an &sk_buff. Unlike most other operations you _MUST_
912 * be careful with this one. A peek leaves the buffer on the
913 * list and someone else may run off with it. You must hold
914 * the appropriate locks or have a private queue to do this.
916 * Returns %NULL for an empty list or a pointer to the tail element.
917 * The reference count is not incremented and the reference is therefore
918 * volatile. Use with caution.
920 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
922 struct sk_buff *list = ((const struct sk_buff *)list_)->prev;
923 if (list == (struct sk_buff *)list_)
929 * skb_queue_len - get queue length
930 * @list_: list to measure
932 * Return the length of an &sk_buff queue.
934 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
940 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
941 * @list: queue to initialize
943 * This initializes only the list and queue length aspects of
944 * an sk_buff_head object. This allows to initialize the list
945 * aspects of an sk_buff_head without reinitializing things like
946 * the spinlock. It can also be used for on-stack sk_buff_head
947 * objects where the spinlock is known to not be used.
949 static inline void __skb_queue_head_init(struct sk_buff_head *list)
951 list->prev = list->next = (struct sk_buff *)list;
956 * This function creates a split out lock class for each invocation;
957 * this is needed for now since a whole lot of users of the skb-queue
958 * infrastructure in drivers have different locking usage (in hardirq)
959 * than the networking core (in softirq only). In the long run either the
960 * network layer or drivers should need annotation to consolidate the
961 * main types of usage into 3 classes.
963 static inline void skb_queue_head_init(struct sk_buff_head *list)
965 spin_lock_init(&list->lock);
966 __skb_queue_head_init(list);
969 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
970 struct lock_class_key *class)
972 skb_queue_head_init(list);
973 lockdep_set_class(&list->lock, class);
977 * Insert an sk_buff on a list.
979 * The "__skb_xxxx()" functions are the non-atomic ones that
980 * can only be called with interrupts disabled.
982 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
983 static inline void __skb_insert(struct sk_buff *newsk,
984 struct sk_buff *prev, struct sk_buff *next,
985 struct sk_buff_head *list)
989 next->prev = prev->next = newsk;
993 static inline void __skb_queue_splice(const struct sk_buff_head *list,
994 struct sk_buff *prev,
995 struct sk_buff *next)
997 struct sk_buff *first = list->next;
998 struct sk_buff *last = list->prev;
1008 * skb_queue_splice - join two skb lists, this is designed for stacks
1009 * @list: the new list to add
1010 * @head: the place to add it in the first list
1012 static inline void skb_queue_splice(const struct sk_buff_head *list,
1013 struct sk_buff_head *head)
1015 if (!skb_queue_empty(list)) {
1016 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1017 head->qlen += list->qlen;
1022 * skb_queue_splice - join two skb lists and reinitialise the emptied list
1023 * @list: the new list to add
1024 * @head: the place to add it in the first list
1026 * The list at @list is reinitialised
1028 static inline void skb_queue_splice_init(struct sk_buff_head *list,
1029 struct sk_buff_head *head)
1031 if (!skb_queue_empty(list)) {
1032 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1033 head->qlen += list->qlen;
1034 __skb_queue_head_init(list);
1039 * skb_queue_splice_tail - join two skb lists, each list being a queue
1040 * @list: the new list to add
1041 * @head: the place to add it in the first list
1043 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1044 struct sk_buff_head *head)
1046 if (!skb_queue_empty(list)) {
1047 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1048 head->qlen += list->qlen;
1053 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
1054 * @list: the new list to add
1055 * @head: the place to add it in the first list
1057 * Each of the lists is a queue.
1058 * The list at @list is reinitialised
1060 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
1061 struct sk_buff_head *head)
1063 if (!skb_queue_empty(list)) {
1064 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1065 head->qlen += list->qlen;
1066 __skb_queue_head_init(list);
1071 * __skb_queue_after - queue a buffer at the list head
1072 * @list: list to use
1073 * @prev: place after this buffer
1074 * @newsk: buffer to queue
1076 * Queue a buffer int the middle of a list. This function takes no locks
1077 * and you must therefore hold required locks before calling it.
1079 * A buffer cannot be placed on two lists at the same time.
1081 static inline void __skb_queue_after(struct sk_buff_head *list,
1082 struct sk_buff *prev,
1083 struct sk_buff *newsk)
1085 __skb_insert(newsk, prev, prev->next, list);
1088 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
1089 struct sk_buff_head *list);
1091 static inline void __skb_queue_before(struct sk_buff_head *list,
1092 struct sk_buff *next,
1093 struct sk_buff *newsk)
1095 __skb_insert(newsk, next->prev, next, list);
1099 * __skb_queue_head - queue a buffer at the list head
1100 * @list: list to use
1101 * @newsk: buffer to queue
1103 * Queue a buffer at the start of a list. This function takes no locks
1104 * and you must therefore hold required locks before calling it.
1106 * A buffer cannot be placed on two lists at the same time.
1108 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
1109 static inline void __skb_queue_head(struct sk_buff_head *list,
1110 struct sk_buff *newsk)
1112 __skb_queue_after(list, (struct sk_buff *)list, newsk);
1116 * __skb_queue_tail - queue a buffer at the list tail
1117 * @list: list to use
1118 * @newsk: buffer to queue
1120 * Queue a buffer at the end of a list. This function takes no locks
1121 * and you must therefore hold required locks before calling it.
1123 * A buffer cannot be placed on two lists at the same time.
1125 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
1126 static inline void __skb_queue_tail(struct sk_buff_head *list,
1127 struct sk_buff *newsk)
1129 __skb_queue_before(list, (struct sk_buff *)list, newsk);
1133 * remove sk_buff from list. _Must_ be called atomically, and with
1136 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
1137 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
1139 struct sk_buff *next, *prev;
1144 skb->next = skb->prev = NULL;
1150 * __skb_dequeue - remove from the head of the queue
1151 * @list: list to dequeue from
1153 * Remove the head of the list. This function does not take any locks
1154 * so must be used with appropriate locks held only. The head item is
1155 * returned or %NULL if the list is empty.
1157 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1158 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1160 struct sk_buff *skb = skb_peek(list);
1162 __skb_unlink(skb, list);
1167 * __skb_dequeue_tail - remove from the tail of the queue
1168 * @list: list to dequeue from
1170 * Remove the tail of the list. This function does not take any locks
1171 * so must be used with appropriate locks held only. The tail item is
1172 * returned or %NULL if the list is empty.
1174 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1175 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1177 struct sk_buff *skb = skb_peek_tail(list);
1179 __skb_unlink(skb, list);
1184 static inline bool skb_is_nonlinear(const struct sk_buff *skb)
1186 return skb->data_len;
1189 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1191 return skb->len - skb->data_len;
1194 static inline int skb_pagelen(const struct sk_buff *skb)
1198 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1199 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
1200 return len + skb_headlen(skb);
1204 * __skb_fill_page_desc - initialise a paged fragment in an skb
1205 * @skb: buffer containing fragment to be initialised
1206 * @i: paged fragment index to initialise
1207 * @page: the page to use for this fragment
1208 * @off: the offset to the data with @page
1209 * @size: the length of the data
1211 * Initialises the @i'th fragment of @skb to point to &size bytes at
1212 * offset @off within @page.
1214 * Does not take any additional reference on the fragment.
1216 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
1217 struct page *page, int off, int size)
1219 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1221 frag->page.p = page;
1222 frag->page_offset = off;
1223 skb_frag_size_set(frag, size);
1227 * skb_fill_page_desc - initialise a paged fragment in an skb
1228 * @skb: buffer containing fragment to be initialised
1229 * @i: paged fragment index to initialise
1230 * @page: the page to use for this fragment
1231 * @off: the offset to the data with @page
1232 * @size: the length of the data
1234 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1235 * @skb to point to &size bytes at offset @off within @page. In
1236 * addition updates @skb such that @i is the last fragment.
1238 * Does not take any additional reference on the fragment.
1240 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1241 struct page *page, int off, int size)
1243 __skb_fill_page_desc(skb, i, page, off, size);
1244 skb_shinfo(skb)->nr_frags = i + 1;
1247 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1248 int off, int size, unsigned int truesize);
1250 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1251 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1252 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1254 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1255 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1257 return skb->head + skb->tail;
1260 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1262 skb->tail = skb->data - skb->head;
1265 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1267 skb_reset_tail_pointer(skb);
1268 skb->tail += offset;
1270 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1271 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1276 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1278 skb->tail = skb->data;
1281 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1283 skb->tail = skb->data + offset;
1286 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1289 * Add data to an sk_buff
1291 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1292 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1294 unsigned char *tmp = skb_tail_pointer(skb);
1295 SKB_LINEAR_ASSERT(skb);
1301 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1302 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1309 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1310 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1313 BUG_ON(skb->len < skb->data_len);
1314 return skb->data += len;
1317 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len)
1319 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
1322 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1324 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1326 if (len > skb_headlen(skb) &&
1327 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1330 return skb->data += len;
1333 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1335 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1338 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1340 if (likely(len <= skb_headlen(skb)))
1342 if (unlikely(len > skb->len))
1344 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1348 * skb_headroom - bytes at buffer head
1349 * @skb: buffer to check
1351 * Return the number of bytes of free space at the head of an &sk_buff.
1353 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1355 return skb->data - skb->head;
1359 * skb_tailroom - bytes at buffer end
1360 * @skb: buffer to check
1362 * Return the number of bytes of free space at the tail of an sk_buff
1364 static inline int skb_tailroom(const struct sk_buff *skb)
1366 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1370 * skb_availroom - bytes at buffer end
1371 * @skb: buffer to check
1373 * Return the number of bytes of free space at the tail of an sk_buff
1374 * allocated by sk_stream_alloc()
1376 static inline int skb_availroom(const struct sk_buff *skb)
1378 return skb_is_nonlinear(skb) ? 0 : skb->avail_size - skb->len;
1382 * skb_reserve - adjust headroom
1383 * @skb: buffer to alter
1384 * @len: bytes to move
1386 * Increase the headroom of an empty &sk_buff by reducing the tail
1387 * room. This is only allowed for an empty buffer.
1389 static inline void skb_reserve(struct sk_buff *skb, int len)
1395 static inline void skb_reset_mac_len(struct sk_buff *skb)
1397 skb->mac_len = skb->network_header - skb->mac_header;
1400 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1401 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1403 return skb->head + skb->transport_header;
1406 static inline void skb_reset_transport_header(struct sk_buff *skb)
1408 skb->transport_header = skb->data - skb->head;
1411 static inline void skb_set_transport_header(struct sk_buff *skb,
1414 skb_reset_transport_header(skb);
1415 skb->transport_header += offset;
1418 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1420 return skb->head + skb->network_header;
1423 static inline void skb_reset_network_header(struct sk_buff *skb)
1425 skb->network_header = skb->data - skb->head;
1428 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1430 skb_reset_network_header(skb);
1431 skb->network_header += offset;
1434 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1436 return skb->head + skb->mac_header;
1439 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1441 return skb->mac_header != ~0U;
1444 static inline void skb_reset_mac_header(struct sk_buff *skb)
1446 skb->mac_header = skb->data - skb->head;
1449 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1451 skb_reset_mac_header(skb);
1452 skb->mac_header += offset;
1455 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1457 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1459 return skb->transport_header;
1462 static inline void skb_reset_transport_header(struct sk_buff *skb)
1464 skb->transport_header = skb->data;
1467 static inline void skb_set_transport_header(struct sk_buff *skb,
1470 skb->transport_header = skb->data + offset;
1473 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1475 return skb->network_header;
1478 static inline void skb_reset_network_header(struct sk_buff *skb)
1480 skb->network_header = skb->data;
1483 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1485 skb->network_header = skb->data + offset;
1488 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1490 return skb->mac_header;
1493 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1495 return skb->mac_header != NULL;
1498 static inline void skb_reset_mac_header(struct sk_buff *skb)
1500 skb->mac_header = skb->data;
1503 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1505 skb->mac_header = skb->data + offset;
1507 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1509 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
1511 if (skb_mac_header_was_set(skb)) {
1512 const unsigned char *old_mac = skb_mac_header(skb);
1514 skb_set_mac_header(skb, -skb->mac_len);
1515 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
1519 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
1521 return skb->csum_start - skb_headroom(skb);
1524 static inline int skb_transport_offset(const struct sk_buff *skb)
1526 return skb_transport_header(skb) - skb->data;
1529 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1531 return skb->transport_header - skb->network_header;
1534 static inline int skb_network_offset(const struct sk_buff *skb)
1536 return skb_network_header(skb) - skb->data;
1539 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
1541 return pskb_may_pull(skb, skb_network_offset(skb) + len);
1545 * CPUs often take a performance hit when accessing unaligned memory
1546 * locations. The actual performance hit varies, it can be small if the
1547 * hardware handles it or large if we have to take an exception and fix it
1550 * Since an ethernet header is 14 bytes network drivers often end up with
1551 * the IP header at an unaligned offset. The IP header can be aligned by
1552 * shifting the start of the packet by 2 bytes. Drivers should do this
1555 * skb_reserve(skb, NET_IP_ALIGN);
1557 * The downside to this alignment of the IP header is that the DMA is now
1558 * unaligned. On some architectures the cost of an unaligned DMA is high
1559 * and this cost outweighs the gains made by aligning the IP header.
1561 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1564 #ifndef NET_IP_ALIGN
1565 #define NET_IP_ALIGN 2
1569 * The networking layer reserves some headroom in skb data (via
1570 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1571 * the header has to grow. In the default case, if the header has to grow
1572 * 32 bytes or less we avoid the reallocation.
1574 * Unfortunately this headroom changes the DMA alignment of the resulting
1575 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1576 * on some architectures. An architecture can override this value,
1577 * perhaps setting it to a cacheline in size (since that will maintain
1578 * cacheline alignment of the DMA). It must be a power of 2.
1580 * Various parts of the networking layer expect at least 32 bytes of
1581 * headroom, you should not reduce this.
1583 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1584 * to reduce average number of cache lines per packet.
1585 * get_rps_cpus() for example only access one 64 bytes aligned block :
1586 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1589 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1592 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1594 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1596 if (unlikely(skb_is_nonlinear(skb))) {
1601 skb_set_tail_pointer(skb, len);
1604 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1606 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1609 return ___pskb_trim(skb, len);
1610 __skb_trim(skb, len);
1614 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1616 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1620 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1621 * @skb: buffer to alter
1624 * This is identical to pskb_trim except that the caller knows that
1625 * the skb is not cloned so we should never get an error due to out-
1628 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1630 int err = pskb_trim(skb, len);
1635 * skb_orphan - orphan a buffer
1636 * @skb: buffer to orphan
1638 * If a buffer currently has an owner then we call the owner's
1639 * destructor function and make the @skb unowned. The buffer continues
1640 * to exist but is no longer charged to its former owner.
1642 static inline void skb_orphan(struct sk_buff *skb)
1644 if (skb->destructor)
1645 skb->destructor(skb);
1646 skb->destructor = NULL;
1651 * __skb_queue_purge - empty a list
1652 * @list: list to empty
1654 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1655 * the list and one reference dropped. This function does not take the
1656 * list lock and the caller must hold the relevant locks to use it.
1658 extern void skb_queue_purge(struct sk_buff_head *list);
1659 static inline void __skb_queue_purge(struct sk_buff_head *list)
1661 struct sk_buff *skb;
1662 while ((skb = __skb_dequeue(list)) != NULL)
1667 * __dev_alloc_skb - allocate an skbuff for receiving
1668 * @length: length to allocate
1669 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1671 * Allocate a new &sk_buff and assign it a usage count of one. The
1672 * buffer has unspecified headroom built in. Users should allocate
1673 * the headroom they think they need without accounting for the
1674 * built in space. The built in space is used for optimisations.
1676 * %NULL is returned if there is no free memory.
1678 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1681 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1683 skb_reserve(skb, NET_SKB_PAD);
1687 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1689 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1690 unsigned int length, gfp_t gfp_mask);
1693 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1694 * @dev: network device to receive on
1695 * @length: length to allocate
1697 * Allocate a new &sk_buff and assign it a usage count of one. The
1698 * buffer has unspecified headroom built in. Users should allocate
1699 * the headroom they think they need without accounting for the
1700 * built in space. The built in space is used for optimisations.
1702 * %NULL is returned if there is no free memory. Although this function
1703 * allocates memory it can be called from an interrupt.
1705 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1706 unsigned int length)
1708 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1711 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
1712 unsigned int length, gfp_t gfp)
1714 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
1716 if (NET_IP_ALIGN && skb)
1717 skb_reserve(skb, NET_IP_ALIGN);
1721 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
1722 unsigned int length)
1724 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
1728 * skb_frag_page - retrieve the page refered to by a paged fragment
1729 * @frag: the paged fragment
1731 * Returns the &struct page associated with @frag.
1733 static inline struct page *skb_frag_page(const skb_frag_t *frag)
1735 return frag->page.p;
1739 * __skb_frag_ref - take an addition reference on a paged fragment.
1740 * @frag: the paged fragment
1742 * Takes an additional reference on the paged fragment @frag.
1744 static inline void __skb_frag_ref(skb_frag_t *frag)
1746 get_page(skb_frag_page(frag));
1750 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
1752 * @f: the fragment offset.
1754 * Takes an additional reference on the @f'th paged fragment of @skb.
1756 static inline void skb_frag_ref(struct sk_buff *skb, int f)
1758 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
1762 * __skb_frag_unref - release a reference on a paged fragment.
1763 * @frag: the paged fragment
1765 * Releases a reference on the paged fragment @frag.
1767 static inline void __skb_frag_unref(skb_frag_t *frag)
1769 put_page(skb_frag_page(frag));
1773 * skb_frag_unref - release a reference on a paged fragment of an skb.
1775 * @f: the fragment offset
1777 * Releases a reference on the @f'th paged fragment of @skb.
1779 static inline void skb_frag_unref(struct sk_buff *skb, int f)
1781 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
1785 * skb_frag_address - gets the address of the data contained in a paged fragment
1786 * @frag: the paged fragment buffer
1788 * Returns the address of the data within @frag. The page must already
1791 static inline void *skb_frag_address(const skb_frag_t *frag)
1793 return page_address(skb_frag_page(frag)) + frag->page_offset;
1797 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
1798 * @frag: the paged fragment buffer
1800 * Returns the address of the data within @frag. Checks that the page
1801 * is mapped and returns %NULL otherwise.
1803 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
1805 void *ptr = page_address(skb_frag_page(frag));
1809 return ptr + frag->page_offset;
1813 * __skb_frag_set_page - sets the page contained in a paged fragment
1814 * @frag: the paged fragment
1815 * @page: the page to set
1817 * Sets the fragment @frag to contain @page.
1819 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
1821 frag->page.p = page;
1825 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
1827 * @f: the fragment offset
1828 * @page: the page to set
1830 * Sets the @f'th fragment of @skb to contain @page.
1832 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
1835 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
1839 * skb_frag_dma_map - maps a paged fragment via the DMA API
1840 * @dev: the device to map the fragment to
1841 * @frag: the paged fragment to map
1842 * @offset: the offset within the fragment (starting at the
1843 * fragment's own offset)
1844 * @size: the number of bytes to map
1845 * @dir: the direction of the mapping (%PCI_DMA_*)
1847 * Maps the page associated with @frag to @device.
1849 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
1850 const skb_frag_t *frag,
1851 size_t offset, size_t size,
1852 enum dma_data_direction dir)
1854 return dma_map_page(dev, skb_frag_page(frag),
1855 frag->page_offset + offset, size, dir);
1858 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
1861 return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
1865 * skb_clone_writable - is the header of a clone writable
1866 * @skb: buffer to check
1867 * @len: length up to which to write
1869 * Returns true if modifying the header part of the cloned buffer
1870 * does not requires the data to be copied.
1872 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
1874 return !skb_header_cloned(skb) &&
1875 skb_headroom(skb) + len <= skb->hdr_len;
1878 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1883 if (headroom < NET_SKB_PAD)
1884 headroom = NET_SKB_PAD;
1885 if (headroom > skb_headroom(skb))
1886 delta = headroom - skb_headroom(skb);
1888 if (delta || cloned)
1889 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1895 * skb_cow - copy header of skb when it is required
1896 * @skb: buffer to cow
1897 * @headroom: needed headroom
1899 * If the skb passed lacks sufficient headroom or its data part
1900 * is shared, data is reallocated. If reallocation fails, an error
1901 * is returned and original skb is not changed.
1903 * The result is skb with writable area skb->head...skb->tail
1904 * and at least @headroom of space at head.
1906 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1908 return __skb_cow(skb, headroom, skb_cloned(skb));
1912 * skb_cow_head - skb_cow but only making the head writable
1913 * @skb: buffer to cow
1914 * @headroom: needed headroom
1916 * This function is identical to skb_cow except that we replace the
1917 * skb_cloned check by skb_header_cloned. It should be used when
1918 * you only need to push on some header and do not need to modify
1921 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1923 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1927 * skb_padto - pad an skbuff up to a minimal size
1928 * @skb: buffer to pad
1929 * @len: minimal length
1931 * Pads up a buffer to ensure the trailing bytes exist and are
1932 * blanked. If the buffer already contains sufficient data it
1933 * is untouched. Otherwise it is extended. Returns zero on
1934 * success. The skb is freed on error.
1937 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1939 unsigned int size = skb->len;
1940 if (likely(size >= len))
1942 return skb_pad(skb, len - size);
1945 static inline int skb_add_data(struct sk_buff *skb,
1946 char __user *from, int copy)
1948 const int off = skb->len;
1950 if (skb->ip_summed == CHECKSUM_NONE) {
1952 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1955 skb->csum = csum_block_add(skb->csum, csum, off);
1958 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1961 __skb_trim(skb, off);
1965 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
1966 const struct page *page, int off)
1969 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1971 return page == skb_frag_page(frag) &&
1972 off == frag->page_offset + skb_frag_size(frag);
1977 static inline int __skb_linearize(struct sk_buff *skb)
1979 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1983 * skb_linearize - convert paged skb to linear one
1984 * @skb: buffer to linarize
1986 * If there is no free memory -ENOMEM is returned, otherwise zero
1987 * is returned and the old skb data released.
1989 static inline int skb_linearize(struct sk_buff *skb)
1991 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1995 * skb_linearize_cow - make sure skb is linear and writable
1996 * @skb: buffer to process
1998 * If there is no free memory -ENOMEM is returned, otherwise zero
1999 * is returned and the old skb data released.
2001 static inline int skb_linearize_cow(struct sk_buff *skb)
2003 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
2004 __skb_linearize(skb) : 0;
2008 * skb_postpull_rcsum - update checksum for received skb after pull
2009 * @skb: buffer to update
2010 * @start: start of data before pull
2011 * @len: length of data pulled
2013 * After doing a pull on a received packet, you need to call this to
2014 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2015 * CHECKSUM_NONE so that it can be recomputed from scratch.
2018 static inline void skb_postpull_rcsum(struct sk_buff *skb,
2019 const void *start, unsigned int len)
2021 if (skb->ip_summed == CHECKSUM_COMPLETE)
2022 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
2025 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
2028 * pskb_trim_rcsum - trim received skb and update checksum
2029 * @skb: buffer to trim
2032 * This is exactly the same as pskb_trim except that it ensures the
2033 * checksum of received packets are still valid after the operation.
2036 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
2038 if (likely(len >= skb->len))
2040 if (skb->ip_summed == CHECKSUM_COMPLETE)
2041 skb->ip_summed = CHECKSUM_NONE;
2042 return __pskb_trim(skb, len);
2045 #define skb_queue_walk(queue, skb) \
2046 for (skb = (queue)->next; \
2047 skb != (struct sk_buff *)(queue); \
2050 #define skb_queue_walk_safe(queue, skb, tmp) \
2051 for (skb = (queue)->next, tmp = skb->next; \
2052 skb != (struct sk_buff *)(queue); \
2053 skb = tmp, tmp = skb->next)
2055 #define skb_queue_walk_from(queue, skb) \
2056 for (; skb != (struct sk_buff *)(queue); \
2059 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2060 for (tmp = skb->next; \
2061 skb != (struct sk_buff *)(queue); \
2062 skb = tmp, tmp = skb->next)
2064 #define skb_queue_reverse_walk(queue, skb) \
2065 for (skb = (queue)->prev; \
2066 skb != (struct sk_buff *)(queue); \
2069 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2070 for (skb = (queue)->prev, tmp = skb->prev; \
2071 skb != (struct sk_buff *)(queue); \
2072 skb = tmp, tmp = skb->prev)
2074 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2075 for (tmp = skb->prev; \
2076 skb != (struct sk_buff *)(queue); \
2077 skb = tmp, tmp = skb->prev)
2079 static inline bool skb_has_frag_list(const struct sk_buff *skb)
2081 return skb_shinfo(skb)->frag_list != NULL;
2084 static inline void skb_frag_list_init(struct sk_buff *skb)
2086 skb_shinfo(skb)->frag_list = NULL;
2089 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
2091 frag->next = skb_shinfo(skb)->frag_list;
2092 skb_shinfo(skb)->frag_list = frag;
2095 #define skb_walk_frags(skb, iter) \
2096 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2098 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
2099 int *peeked, int *off, int *err);
2100 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
2101 int noblock, int *err);
2102 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
2103 struct poll_table_struct *wait);
2104 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
2105 int offset, struct iovec *to,
2107 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
2110 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
2112 const struct iovec *from,
2115 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from,
2117 const struct iovec *to,
2120 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
2121 extern void skb_free_datagram_locked(struct sock *sk,
2122 struct sk_buff *skb);
2123 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
2124 unsigned int flags);
2125 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
2126 int len, __wsum csum);
2127 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
2129 extern int skb_store_bits(struct sk_buff *skb, int offset,
2130 const void *from, int len);
2131 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
2132 int offset, u8 *to, int len,
2134 extern int skb_splice_bits(struct sk_buff *skb,
2135 unsigned int offset,
2136 struct pipe_inode_info *pipe,
2138 unsigned int flags);
2139 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
2140 extern void skb_split(struct sk_buff *skb,
2141 struct sk_buff *skb1, const u32 len);
2142 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
2145 extern struct sk_buff *skb_segment(struct sk_buff *skb,
2146 netdev_features_t features);
2148 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
2149 int len, void *buffer)
2151 int hlen = skb_headlen(skb);
2153 if (hlen - offset >= len)
2154 return skb->data + offset;
2156 if (skb_copy_bits(skb, offset, buffer, len) < 0)
2162 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
2164 const unsigned int len)
2166 memcpy(to, skb->data, len);
2169 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
2170 const int offset, void *to,
2171 const unsigned int len)
2173 memcpy(to, skb->data + offset, len);
2176 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
2178 const unsigned int len)
2180 memcpy(skb->data, from, len);
2183 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
2186 const unsigned int len)
2188 memcpy(skb->data + offset, from, len);
2191 extern void skb_init(void);
2193 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
2199 * skb_get_timestamp - get timestamp from a skb
2200 * @skb: skb to get stamp from
2201 * @stamp: pointer to struct timeval to store stamp in
2203 * Timestamps are stored in the skb as offsets to a base timestamp.
2204 * This function converts the offset back to a struct timeval and stores
2207 static inline void skb_get_timestamp(const struct sk_buff *skb,
2208 struct timeval *stamp)
2210 *stamp = ktime_to_timeval(skb->tstamp);
2213 static inline void skb_get_timestampns(const struct sk_buff *skb,
2214 struct timespec *stamp)
2216 *stamp = ktime_to_timespec(skb->tstamp);
2219 static inline void __net_timestamp(struct sk_buff *skb)
2221 skb->tstamp = ktime_get_real();
2224 static inline ktime_t net_timedelta(ktime_t t)
2226 return ktime_sub(ktime_get_real(), t);
2229 static inline ktime_t net_invalid_timestamp(void)
2231 return ktime_set(0, 0);
2234 extern void skb_timestamping_init(void);
2236 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2238 extern void skb_clone_tx_timestamp(struct sk_buff *skb);
2239 extern bool skb_defer_rx_timestamp(struct sk_buff *skb);
2241 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2243 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
2247 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
2252 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2255 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2257 * PHY drivers may accept clones of transmitted packets for
2258 * timestamping via their phy_driver.txtstamp method. These drivers
2259 * must call this function to return the skb back to the stack, with
2260 * or without a timestamp.
2262 * @skb: clone of the the original outgoing packet
2263 * @hwtstamps: hardware time stamps, may be NULL if not available
2266 void skb_complete_tx_timestamp(struct sk_buff *skb,
2267 struct skb_shared_hwtstamps *hwtstamps);
2270 * skb_tstamp_tx - queue clone of skb with send time stamps
2271 * @orig_skb: the original outgoing packet
2272 * @hwtstamps: hardware time stamps, may be NULL if not available
2274 * If the skb has a socket associated, then this function clones the
2275 * skb (thus sharing the actual data and optional structures), stores
2276 * the optional hardware time stamping information (if non NULL) or
2277 * generates a software time stamp (otherwise), then queues the clone
2278 * to the error queue of the socket. Errors are silently ignored.
2280 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
2281 struct skb_shared_hwtstamps *hwtstamps);
2283 static inline void sw_tx_timestamp(struct sk_buff *skb)
2285 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP &&
2286 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
2287 skb_tstamp_tx(skb, NULL);
2291 * skb_tx_timestamp() - Driver hook for transmit timestamping
2293 * Ethernet MAC Drivers should call this function in their hard_xmit()
2294 * function immediately before giving the sk_buff to the MAC hardware.
2296 * @skb: A socket buffer.
2298 static inline void skb_tx_timestamp(struct sk_buff *skb)
2300 skb_clone_tx_timestamp(skb);
2301 sw_tx_timestamp(skb);
2305 * skb_complete_wifi_ack - deliver skb with wifi status
2307 * @skb: the original outgoing packet
2308 * @acked: ack status
2311 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
2313 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
2314 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
2316 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
2318 return skb->ip_summed & CHECKSUM_UNNECESSARY;
2322 * skb_checksum_complete - Calculate checksum of an entire packet
2323 * @skb: packet to process
2325 * This function calculates the checksum over the entire packet plus
2326 * the value of skb->csum. The latter can be used to supply the
2327 * checksum of a pseudo header as used by TCP/UDP. It returns the
2330 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2331 * this function can be used to verify that checksum on received
2332 * packets. In that case the function should return zero if the
2333 * checksum is correct. In particular, this function will return zero
2334 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2335 * hardware has already verified the correctness of the checksum.
2337 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
2339 return skb_csum_unnecessary(skb) ?
2340 0 : __skb_checksum_complete(skb);
2343 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2344 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
2345 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
2347 if (nfct && atomic_dec_and_test(&nfct->use))
2348 nf_conntrack_destroy(nfct);
2350 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
2353 atomic_inc(&nfct->use);
2356 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2357 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
2360 atomic_inc(&skb->users);
2362 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
2368 #ifdef CONFIG_BRIDGE_NETFILTER
2369 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
2371 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
2374 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
2377 atomic_inc(&nf_bridge->use);
2379 #endif /* CONFIG_BRIDGE_NETFILTER */
2380 static inline void nf_reset(struct sk_buff *skb)
2382 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2383 nf_conntrack_put(skb->nfct);
2386 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2387 nf_conntrack_put_reasm(skb->nfct_reasm);
2388 skb->nfct_reasm = NULL;
2390 #ifdef CONFIG_BRIDGE_NETFILTER
2391 nf_bridge_put(skb->nf_bridge);
2392 skb->nf_bridge = NULL;
2396 /* Note: This doesn't put any conntrack and bridge info in dst. */
2397 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2399 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2400 dst->nfct = src->nfct;
2401 nf_conntrack_get(src->nfct);
2402 dst->nfctinfo = src->nfctinfo;
2404 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2405 dst->nfct_reasm = src->nfct_reasm;
2406 nf_conntrack_get_reasm(src->nfct_reasm);
2408 #ifdef CONFIG_BRIDGE_NETFILTER
2409 dst->nf_bridge = src->nf_bridge;
2410 nf_bridge_get(src->nf_bridge);
2414 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2416 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2417 nf_conntrack_put(dst->nfct);
2419 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2420 nf_conntrack_put_reasm(dst->nfct_reasm);
2422 #ifdef CONFIG_BRIDGE_NETFILTER
2423 nf_bridge_put(dst->nf_bridge);
2425 __nf_copy(dst, src);
2428 #ifdef CONFIG_NETWORK_SECMARK
2429 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2431 to->secmark = from->secmark;
2434 static inline void skb_init_secmark(struct sk_buff *skb)
2439 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2442 static inline void skb_init_secmark(struct sk_buff *skb)
2446 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
2448 skb->queue_mapping = queue_mapping;
2451 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
2453 return skb->queue_mapping;
2456 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
2458 to->queue_mapping = from->queue_mapping;
2461 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
2463 skb->queue_mapping = rx_queue + 1;
2466 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2468 return skb->queue_mapping - 1;
2471 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2473 return skb->queue_mapping != 0;
2476 extern u16 __skb_tx_hash(const struct net_device *dev,
2477 const struct sk_buff *skb,
2478 unsigned int num_tx_queues);
2481 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2486 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2492 static inline bool skb_is_gso(const struct sk_buff *skb)
2494 return skb_shinfo(skb)->gso_size;
2497 static inline bool skb_is_gso_v6(const struct sk_buff *skb)
2499 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2502 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2504 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2506 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2507 * wanted then gso_type will be set. */
2508 const struct skb_shared_info *shinfo = skb_shinfo(skb);
2510 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
2511 unlikely(shinfo->gso_type == 0)) {
2512 __skb_warn_lro_forwarding(skb);
2518 static inline void skb_forward_csum(struct sk_buff *skb)
2520 /* Unfortunately we don't support this one. Any brave souls? */
2521 if (skb->ip_summed == CHECKSUM_COMPLETE)
2522 skb->ip_summed = CHECKSUM_NONE;
2526 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
2527 * @skb: skb to check
2529 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
2530 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
2531 * use this helper, to document places where we make this assertion.
2533 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
2536 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
2540 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2542 static inline bool skb_is_recycleable(const struct sk_buff *skb, int skb_size)
2544 if (irqs_disabled())
2547 if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY)
2550 if (skb_is_nonlinear(skb) || skb->fclone != SKB_FCLONE_UNAVAILABLE)
2553 skb_size = SKB_DATA_ALIGN(skb_size + NET_SKB_PAD);
2554 if (skb_end_pointer(skb) - skb->head < skb_size)
2557 if (skb_shared(skb) || skb_cloned(skb))
2562 #endif /* __KERNEL__ */
2563 #endif /* _LINUX_SKBUFF_H */