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 {
122 struct net_device *physindev;
123 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 ctx field is used to track device context.
242 * The desc field is used to track userspace buffer index.
245 void (*callback)(struct ubuf_info *);
250 /* This data is invariant across clones and lives at
251 * the end of the header data, ie. at skb->end.
253 struct skb_shared_info {
254 unsigned char nr_frags;
256 unsigned short gso_size;
257 /* Warning: this field is not always filled in (UFO)! */
258 unsigned short gso_segs;
259 unsigned short gso_type;
260 struct sk_buff *frag_list;
261 struct skb_shared_hwtstamps hwtstamps;
265 * Warning : all fields before dataref are cleared in __alloc_skb()
269 /* Intermediate layers must ensure that destructor_arg
270 * remains valid until skb destructor */
271 void * destructor_arg;
273 /* must be last field, see pskb_expand_head() */
274 skb_frag_t frags[MAX_SKB_FRAGS];
277 /* We divide dataref into two halves. The higher 16 bits hold references
278 * to the payload part of skb->data. The lower 16 bits hold references to
279 * the entire skb->data. A clone of a headerless skb holds the length of
280 * the header in skb->hdr_len.
282 * All users must obey the rule that the skb->data reference count must be
283 * greater than or equal to the payload reference count.
285 * Holding a reference to the payload part means that the user does not
286 * care about modifications to the header part of skb->data.
288 #define SKB_DATAREF_SHIFT 16
289 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
293 SKB_FCLONE_UNAVAILABLE,
299 SKB_GSO_TCPV4 = 1 << 0,
300 SKB_GSO_UDP = 1 << 1,
302 /* This indicates the skb is from an untrusted source. */
303 SKB_GSO_DODGY = 1 << 2,
305 /* This indicates the tcp segment has CWR set. */
306 SKB_GSO_TCP_ECN = 1 << 3,
308 SKB_GSO_TCPV6 = 1 << 4,
310 SKB_GSO_FCOE = 1 << 5,
313 #if BITS_PER_LONG > 32
314 #define NET_SKBUFF_DATA_USES_OFFSET 1
317 #ifdef NET_SKBUFF_DATA_USES_OFFSET
318 typedef unsigned int sk_buff_data_t;
320 typedef unsigned char *sk_buff_data_t;
323 #if defined(CONFIG_NF_DEFRAG_IPV4) || defined(CONFIG_NF_DEFRAG_IPV4_MODULE) || \
324 defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE)
325 #define NET_SKBUFF_NF_DEFRAG_NEEDED 1
329 * struct sk_buff - socket buffer
330 * @next: Next buffer in list
331 * @prev: Previous buffer in list
332 * @tstamp: Time we arrived
333 * @sk: Socket we are owned by
334 * @dev: Device we arrived on/are leaving by
335 * @cb: Control buffer. Free for use by every layer. Put private vars here
336 * @_skb_refdst: destination entry (with norefcount bit)
337 * @sp: the security path, used for xfrm
338 * @len: Length of actual data
339 * @data_len: Data length
340 * @mac_len: Length of link layer header
341 * @hdr_len: writable header length of cloned skb
342 * @csum: Checksum (must include start/offset pair)
343 * @csum_start: Offset from skb->head where checksumming should start
344 * @csum_offset: Offset from csum_start where checksum should be stored
345 * @priority: Packet queueing priority
346 * @local_df: allow local fragmentation
347 * @cloned: Head may be cloned (check refcnt to be sure)
348 * @ip_summed: Driver fed us an IP checksum
349 * @nohdr: Payload reference only, must not modify header
350 * @nfctinfo: Relationship of this skb to the connection
351 * @pkt_type: Packet class
352 * @fclone: skbuff clone status
353 * @ipvs_property: skbuff is owned by ipvs
354 * @peeked: this packet has been seen already, so stats have been
355 * done for it, don't do them again
356 * @nf_trace: netfilter packet trace flag
357 * @protocol: Packet protocol from driver
358 * @destructor: Destruct function
359 * @nfct: Associated connection, if any
360 * @nfct_reasm: netfilter conntrack re-assembly pointer
361 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
362 * @skb_iif: ifindex of device we arrived on
363 * @tc_index: Traffic control index
364 * @tc_verd: traffic control verdict
365 * @rxhash: the packet hash computed on receive
366 * @queue_mapping: Queue mapping for multiqueue devices
367 * @ndisc_nodetype: router type (from link layer)
368 * @ooo_okay: allow the mapping of a socket to a queue to be changed
369 * @l4_rxhash: indicate rxhash is a canonical 4-tuple hash over transport
371 * @wifi_acked_valid: wifi_acked was set
372 * @wifi_acked: whether frame was acked on wifi or not
373 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
374 * @dma_cookie: a cookie to one of several possible DMA operations
375 * done by skb DMA functions
376 * @secmark: security marking
377 * @mark: Generic packet mark
378 * @dropcount: total number of sk_receive_queue overflows
379 * @vlan_tci: vlan tag control information
380 * @transport_header: Transport layer header
381 * @network_header: Network layer header
382 * @mac_header: Link layer header
383 * @tail: Tail pointer
385 * @head: Head of buffer
386 * @data: Data head pointer
387 * @truesize: Buffer size
388 * @users: User count - see {datagram,tcp}.c
392 /* These two members must be first. */
393 struct sk_buff *next;
394 struct sk_buff *prev;
399 struct net_device *dev;
402 * This is the control buffer. It is free to use for every
403 * layer. Please put your private variables there. If you
404 * want to keep them across layers you have to do a skb_clone()
405 * first. This is owned by whoever has the skb queued ATM.
407 char cb[48] __aligned(8);
409 unsigned long _skb_refdst;
425 kmemcheck_bitfield_begin(flags1);
436 kmemcheck_bitfield_end(flags1);
439 void (*destructor)(struct sk_buff *skb);
440 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
441 struct nf_conntrack *nfct;
443 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
444 struct sk_buff *nfct_reasm;
446 #ifdef CONFIG_BRIDGE_NETFILTER
447 struct nf_bridge_info *nf_bridge;
456 #ifdef CONFIG_NET_SCHED
457 __u16 tc_index; /* traffic control index */
458 #ifdef CONFIG_NET_CLS_ACT
459 __u16 tc_verd; /* traffic control verdict */
464 kmemcheck_bitfield_begin(flags2);
465 #ifdef CONFIG_IPV6_NDISC_NODETYPE
466 __u8 ndisc_nodetype:2;
470 __u8 wifi_acked_valid:1;
474 /* 8/10 bit hole (depending on ndisc_nodetype presence) */
475 kmemcheck_bitfield_end(flags2);
477 #ifdef CONFIG_NET_DMA
478 dma_cookie_t dma_cookie;
480 #ifdef CONFIG_NETWORK_SECMARK
489 sk_buff_data_t transport_header;
490 sk_buff_data_t network_header;
491 sk_buff_data_t mac_header;
492 /* These elements must be at the end, see alloc_skb() for details. */
497 unsigned int truesize;
503 * Handling routines are only of interest to the kernel
505 #include <linux/slab.h>
509 * skb might have a dst pointer attached, refcounted or not.
510 * _skb_refdst low order bit is set if refcount was _not_ taken
512 #define SKB_DST_NOREF 1UL
513 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
516 * skb_dst - returns skb dst_entry
519 * Returns skb dst_entry, regardless of reference taken or not.
521 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
523 /* If refdst was not refcounted, check we still are in a
524 * rcu_read_lock section
526 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
527 !rcu_read_lock_held() &&
528 !rcu_read_lock_bh_held());
529 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
533 * skb_dst_set - sets skb dst
537 * Sets skb dst, assuming a reference was taken on dst and should
538 * be released by skb_dst_drop()
540 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
542 skb->_skb_refdst = (unsigned long)dst;
545 extern void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst);
548 * skb_dst_is_noref - Test if skb dst isn't refcounted
551 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
553 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
556 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
558 return (struct rtable *)skb_dst(skb);
561 extern void kfree_skb(struct sk_buff *skb);
562 extern void consume_skb(struct sk_buff *skb);
563 extern void __kfree_skb(struct sk_buff *skb);
564 extern struct kmem_cache *skbuff_head_cache;
565 extern struct sk_buff *__alloc_skb(unsigned int size,
566 gfp_t priority, int fclone, int node);
567 extern struct sk_buff *build_skb(void *data, unsigned int frag_size);
568 static inline struct sk_buff *alloc_skb(unsigned int size,
571 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
574 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
577 return __alloc_skb(size, priority, 1, NUMA_NO_NODE);
580 extern void skb_recycle(struct sk_buff *skb);
581 extern bool skb_recycle_check(struct sk_buff *skb, int skb_size);
583 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
584 extern int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
585 extern struct sk_buff *skb_clone(struct sk_buff *skb,
587 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
589 extern struct sk_buff *__pskb_copy(struct sk_buff *skb,
590 int headroom, gfp_t gfp_mask);
592 extern int pskb_expand_head(struct sk_buff *skb,
593 int nhead, int ntail,
595 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
596 unsigned int headroom);
597 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
598 int newheadroom, int newtailroom,
600 extern int skb_to_sgvec(struct sk_buff *skb,
601 struct scatterlist *sg, int offset,
603 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
604 struct sk_buff **trailer);
605 extern int skb_pad(struct sk_buff *skb, int pad);
606 #define dev_kfree_skb(a) consume_skb(a)
608 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
609 int getfrag(void *from, char *to, int offset,
610 int len,int odd, struct sk_buff *skb),
611 void *from, int length);
613 struct skb_seq_state {
617 __u32 stepped_offset;
618 struct sk_buff *root_skb;
619 struct sk_buff *cur_skb;
623 extern void skb_prepare_seq_read(struct sk_buff *skb,
624 unsigned int from, unsigned int to,
625 struct skb_seq_state *st);
626 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
627 struct skb_seq_state *st);
628 extern void skb_abort_seq_read(struct skb_seq_state *st);
630 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
631 unsigned int to, struct ts_config *config,
632 struct ts_state *state);
634 extern void __skb_get_rxhash(struct sk_buff *skb);
635 static inline __u32 skb_get_rxhash(struct sk_buff *skb)
638 __skb_get_rxhash(skb);
643 #ifdef NET_SKBUFF_DATA_USES_OFFSET
644 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
646 return skb->head + skb->end;
649 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
656 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
658 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
660 return &skb_shinfo(skb)->hwtstamps;
664 * skb_queue_empty - check if a queue is empty
667 * Returns true if the queue is empty, false otherwise.
669 static inline int skb_queue_empty(const struct sk_buff_head *list)
671 return list->next == (struct sk_buff *)list;
675 * skb_queue_is_last - check if skb is the last entry in the queue
679 * Returns true if @skb is the last buffer on the list.
681 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
682 const struct sk_buff *skb)
684 return skb->next == (struct sk_buff *)list;
688 * skb_queue_is_first - check if skb is the first entry in the queue
692 * Returns true if @skb is the first buffer on the list.
694 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
695 const struct sk_buff *skb)
697 return skb->prev == (struct sk_buff *)list;
701 * skb_queue_next - return the next packet in the queue
703 * @skb: current buffer
705 * Return the next packet in @list after @skb. It is only valid to
706 * call this if skb_queue_is_last() evaluates to false.
708 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
709 const struct sk_buff *skb)
711 /* This BUG_ON may seem severe, but if we just return then we
712 * are going to dereference garbage.
714 BUG_ON(skb_queue_is_last(list, skb));
719 * skb_queue_prev - return the prev packet in the queue
721 * @skb: current buffer
723 * Return the prev packet in @list before @skb. It is only valid to
724 * call this if skb_queue_is_first() evaluates to false.
726 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
727 const struct sk_buff *skb)
729 /* This BUG_ON may seem severe, but if we just return then we
730 * are going to dereference garbage.
732 BUG_ON(skb_queue_is_first(list, skb));
737 * skb_get - reference buffer
738 * @skb: buffer to reference
740 * Makes another reference to a socket buffer and returns a pointer
743 static inline struct sk_buff *skb_get(struct sk_buff *skb)
745 atomic_inc(&skb->users);
750 * If users == 1, we are the only owner and are can avoid redundant
755 * skb_cloned - is the buffer a clone
756 * @skb: buffer to check
758 * Returns true if the buffer was generated with skb_clone() and is
759 * one of multiple shared copies of the buffer. Cloned buffers are
760 * shared data so must not be written to under normal circumstances.
762 static inline int skb_cloned(const struct sk_buff *skb)
764 return skb->cloned &&
765 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
769 * skb_header_cloned - is the header a clone
770 * @skb: buffer to check
772 * Returns true if modifying the header part of the buffer requires
773 * the data to be copied.
775 static inline int skb_header_cloned(const struct sk_buff *skb)
782 dataref = atomic_read(&skb_shinfo(skb)->dataref);
783 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
788 * skb_header_release - release reference to header
789 * @skb: buffer to operate on
791 * Drop a reference to the header part of the buffer. This is done
792 * by acquiring a payload reference. You must not read from the header
793 * part of skb->data after this.
795 static inline void skb_header_release(struct sk_buff *skb)
799 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
803 * skb_shared - is the buffer shared
804 * @skb: buffer to check
806 * Returns true if more than one person has a reference to this
809 static inline int skb_shared(const struct sk_buff *skb)
811 return atomic_read(&skb->users) != 1;
815 * skb_share_check - check if buffer is shared and if so clone it
816 * @skb: buffer to check
817 * @pri: priority for memory allocation
819 * If the buffer is shared the buffer is cloned and the old copy
820 * drops a reference. A new clone with a single reference is returned.
821 * If the buffer is not shared the original buffer is returned. When
822 * being called from interrupt status or with spinlocks held pri must
825 * NULL is returned on a memory allocation failure.
827 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
830 might_sleep_if(pri & __GFP_WAIT);
831 if (skb_shared(skb)) {
832 struct sk_buff *nskb = skb_clone(skb, pri);
840 * Copy shared buffers into a new sk_buff. We effectively do COW on
841 * packets to handle cases where we have a local reader and forward
842 * and a couple of other messy ones. The normal one is tcpdumping
843 * a packet thats being forwarded.
847 * skb_unshare - make a copy of a shared buffer
848 * @skb: buffer to check
849 * @pri: priority for memory allocation
851 * If the socket buffer is a clone then this function creates a new
852 * copy of the data, drops a reference count on the old copy and returns
853 * the new copy with the reference count at 1. If the buffer is not a clone
854 * the original buffer is returned. When called with a spinlock held or
855 * from interrupt state @pri must be %GFP_ATOMIC
857 * %NULL is returned on a memory allocation failure.
859 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
862 might_sleep_if(pri & __GFP_WAIT);
863 if (skb_cloned(skb)) {
864 struct sk_buff *nskb = skb_copy(skb, pri);
865 kfree_skb(skb); /* Free our shared copy */
872 * skb_peek - peek at the head of an &sk_buff_head
873 * @list_: list to peek at
875 * Peek an &sk_buff. Unlike most other operations you _MUST_
876 * be careful with this one. A peek leaves the buffer on the
877 * list and someone else may run off with it. You must hold
878 * the appropriate locks or have a private queue to do this.
880 * Returns %NULL for an empty list or a pointer to the head element.
881 * The reference count is not incremented and the reference is therefore
882 * volatile. Use with caution.
884 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
886 struct sk_buff *list = ((const struct sk_buff *)list_)->next;
887 if (list == (struct sk_buff *)list_)
893 * skb_peek_next - peek skb following the given one from a queue
894 * @skb: skb to start from
895 * @list_: list to peek at
897 * Returns %NULL when the end of the list is met or a pointer to the
898 * next element. The reference count is not incremented and the
899 * reference is therefore volatile. Use with caution.
901 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
902 const struct sk_buff_head *list_)
904 struct sk_buff *next = skb->next;
905 if (next == (struct sk_buff *)list_)
911 * skb_peek_tail - peek at the tail of an &sk_buff_head
912 * @list_: list to peek at
914 * Peek an &sk_buff. Unlike most other operations you _MUST_
915 * be careful with this one. A peek leaves the buffer on the
916 * list and someone else may run off with it. You must hold
917 * the appropriate locks or have a private queue to do this.
919 * Returns %NULL for an empty list or a pointer to the tail element.
920 * The reference count is not incremented and the reference is therefore
921 * volatile. Use with caution.
923 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
925 struct sk_buff *list = ((const struct sk_buff *)list_)->prev;
926 if (list == (struct sk_buff *)list_)
932 * skb_queue_len - get queue length
933 * @list_: list to measure
935 * Return the length of an &sk_buff queue.
937 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
943 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
944 * @list: queue to initialize
946 * This initializes only the list and queue length aspects of
947 * an sk_buff_head object. This allows to initialize the list
948 * aspects of an sk_buff_head without reinitializing things like
949 * the spinlock. It can also be used for on-stack sk_buff_head
950 * objects where the spinlock is known to not be used.
952 static inline void __skb_queue_head_init(struct sk_buff_head *list)
954 list->prev = list->next = (struct sk_buff *)list;
959 * This function creates a split out lock class for each invocation;
960 * this is needed for now since a whole lot of users of the skb-queue
961 * infrastructure in drivers have different locking usage (in hardirq)
962 * than the networking core (in softirq only). In the long run either the
963 * network layer or drivers should need annotation to consolidate the
964 * main types of usage into 3 classes.
966 static inline void skb_queue_head_init(struct sk_buff_head *list)
968 spin_lock_init(&list->lock);
969 __skb_queue_head_init(list);
972 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
973 struct lock_class_key *class)
975 skb_queue_head_init(list);
976 lockdep_set_class(&list->lock, class);
980 * Insert an sk_buff on a list.
982 * The "__skb_xxxx()" functions are the non-atomic ones that
983 * can only be called with interrupts disabled.
985 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
986 static inline void __skb_insert(struct sk_buff *newsk,
987 struct sk_buff *prev, struct sk_buff *next,
988 struct sk_buff_head *list)
992 next->prev = prev->next = newsk;
996 static inline void __skb_queue_splice(const struct sk_buff_head *list,
997 struct sk_buff *prev,
998 struct sk_buff *next)
1000 struct sk_buff *first = list->next;
1001 struct sk_buff *last = list->prev;
1011 * skb_queue_splice - join two skb lists, this is designed for stacks
1012 * @list: the new list to add
1013 * @head: the place to add it in the first list
1015 static inline void skb_queue_splice(const struct sk_buff_head *list,
1016 struct sk_buff_head *head)
1018 if (!skb_queue_empty(list)) {
1019 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1020 head->qlen += list->qlen;
1025 * skb_queue_splice - join two skb lists and reinitialise the emptied list
1026 * @list: the new list to add
1027 * @head: the place to add it in the first list
1029 * The list at @list is reinitialised
1031 static inline void skb_queue_splice_init(struct sk_buff_head *list,
1032 struct sk_buff_head *head)
1034 if (!skb_queue_empty(list)) {
1035 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1036 head->qlen += list->qlen;
1037 __skb_queue_head_init(list);
1042 * skb_queue_splice_tail - join two skb lists, each list being a queue
1043 * @list: the new list to add
1044 * @head: the place to add it in the first list
1046 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1047 struct sk_buff_head *head)
1049 if (!skb_queue_empty(list)) {
1050 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1051 head->qlen += list->qlen;
1056 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
1057 * @list: the new list to add
1058 * @head: the place to add it in the first list
1060 * Each of the lists is a queue.
1061 * The list at @list is reinitialised
1063 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
1064 struct sk_buff_head *head)
1066 if (!skb_queue_empty(list)) {
1067 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1068 head->qlen += list->qlen;
1069 __skb_queue_head_init(list);
1074 * __skb_queue_after - queue a buffer at the list head
1075 * @list: list to use
1076 * @prev: place after this buffer
1077 * @newsk: buffer to queue
1079 * Queue a buffer int the middle of a list. This function takes no locks
1080 * and you must therefore hold required locks before calling it.
1082 * A buffer cannot be placed on two lists at the same time.
1084 static inline void __skb_queue_after(struct sk_buff_head *list,
1085 struct sk_buff *prev,
1086 struct sk_buff *newsk)
1088 __skb_insert(newsk, prev, prev->next, list);
1091 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
1092 struct sk_buff_head *list);
1094 static inline void __skb_queue_before(struct sk_buff_head *list,
1095 struct sk_buff *next,
1096 struct sk_buff *newsk)
1098 __skb_insert(newsk, next->prev, next, list);
1102 * __skb_queue_head - queue a buffer at the list head
1103 * @list: list to use
1104 * @newsk: buffer to queue
1106 * Queue a buffer at the start of a list. This function takes no locks
1107 * and you must therefore hold required locks before calling it.
1109 * A buffer cannot be placed on two lists at the same time.
1111 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
1112 static inline void __skb_queue_head(struct sk_buff_head *list,
1113 struct sk_buff *newsk)
1115 __skb_queue_after(list, (struct sk_buff *)list, newsk);
1119 * __skb_queue_tail - queue a buffer at the list tail
1120 * @list: list to use
1121 * @newsk: buffer to queue
1123 * Queue a buffer at the end of a list. This function takes no locks
1124 * and you must therefore hold required locks before calling it.
1126 * A buffer cannot be placed on two lists at the same time.
1128 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
1129 static inline void __skb_queue_tail(struct sk_buff_head *list,
1130 struct sk_buff *newsk)
1132 __skb_queue_before(list, (struct sk_buff *)list, newsk);
1136 * remove sk_buff from list. _Must_ be called atomically, and with
1139 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
1140 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
1142 struct sk_buff *next, *prev;
1147 skb->next = skb->prev = NULL;
1153 * __skb_dequeue - remove from the head of the queue
1154 * @list: list to dequeue from
1156 * Remove the head of the list. This function does not take any locks
1157 * so must be used with appropriate locks held only. The head item is
1158 * returned or %NULL if the list is empty.
1160 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1161 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1163 struct sk_buff *skb = skb_peek(list);
1165 __skb_unlink(skb, list);
1170 * __skb_dequeue_tail - remove from the tail of the queue
1171 * @list: list to dequeue from
1173 * Remove the tail of the list. This function does not take any locks
1174 * so must be used with appropriate locks held only. The tail item is
1175 * returned or %NULL if the list is empty.
1177 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1178 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1180 struct sk_buff *skb = skb_peek_tail(list);
1182 __skb_unlink(skb, list);
1187 static inline bool skb_is_nonlinear(const struct sk_buff *skb)
1189 return skb->data_len;
1192 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1194 return skb->len - skb->data_len;
1197 static inline int skb_pagelen(const struct sk_buff *skb)
1201 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1202 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
1203 return len + skb_headlen(skb);
1207 * __skb_fill_page_desc - initialise a paged fragment in an skb
1208 * @skb: buffer containing fragment to be initialised
1209 * @i: paged fragment index to initialise
1210 * @page: the page to use for this fragment
1211 * @off: the offset to the data with @page
1212 * @size: the length of the data
1214 * Initialises the @i'th fragment of @skb to point to &size bytes at
1215 * offset @off within @page.
1217 * Does not take any additional reference on the fragment.
1219 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
1220 struct page *page, int off, int size)
1222 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1224 frag->page.p = page;
1225 frag->page_offset = off;
1226 skb_frag_size_set(frag, size);
1230 * skb_fill_page_desc - initialise a paged fragment in an skb
1231 * @skb: buffer containing fragment to be initialised
1232 * @i: paged fragment index to initialise
1233 * @page: the page to use for this fragment
1234 * @off: the offset to the data with @page
1235 * @size: the length of the data
1237 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1238 * @skb to point to &size bytes at offset @off within @page. In
1239 * addition updates @skb such that @i is the last fragment.
1241 * Does not take any additional reference on the fragment.
1243 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1244 struct page *page, int off, int size)
1246 __skb_fill_page_desc(skb, i, page, off, size);
1247 skb_shinfo(skb)->nr_frags = i + 1;
1250 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1251 int off, int size, unsigned int truesize);
1253 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1254 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1255 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1257 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1258 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1260 return skb->head + skb->tail;
1263 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1265 skb->tail = skb->data - skb->head;
1268 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1270 skb_reset_tail_pointer(skb);
1271 skb->tail += offset;
1273 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1274 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1279 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1281 skb->tail = skb->data;
1284 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1286 skb->tail = skb->data + offset;
1289 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1292 * Add data to an sk_buff
1294 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1295 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1297 unsigned char *tmp = skb_tail_pointer(skb);
1298 SKB_LINEAR_ASSERT(skb);
1304 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1305 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1312 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1313 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1316 BUG_ON(skb->len < skb->data_len);
1317 return skb->data += len;
1320 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len)
1322 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
1325 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1327 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1329 if (len > skb_headlen(skb) &&
1330 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1333 return skb->data += len;
1336 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1338 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1341 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1343 if (likely(len <= skb_headlen(skb)))
1345 if (unlikely(len > skb->len))
1347 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1351 * skb_headroom - bytes at buffer head
1352 * @skb: buffer to check
1354 * Return the number of bytes of free space at the head of an &sk_buff.
1356 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1358 return skb->data - skb->head;
1362 * skb_tailroom - bytes at buffer end
1363 * @skb: buffer to check
1365 * Return the number of bytes of free space at the tail of an sk_buff
1367 static inline int skb_tailroom(const struct sk_buff *skb)
1369 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1373 * skb_availroom - bytes at buffer end
1374 * @skb: buffer to check
1376 * Return the number of bytes of free space at the tail of an sk_buff
1377 * allocated by sk_stream_alloc()
1379 static inline int skb_availroom(const struct sk_buff *skb)
1381 return skb_is_nonlinear(skb) ? 0 : skb->avail_size - skb->len;
1385 * skb_reserve - adjust headroom
1386 * @skb: buffer to alter
1387 * @len: bytes to move
1389 * Increase the headroom of an empty &sk_buff by reducing the tail
1390 * room. This is only allowed for an empty buffer.
1392 static inline void skb_reserve(struct sk_buff *skb, int len)
1398 static inline void skb_reset_mac_len(struct sk_buff *skb)
1400 skb->mac_len = skb->network_header - skb->mac_header;
1403 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1404 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1406 return skb->head + skb->transport_header;
1409 static inline void skb_reset_transport_header(struct sk_buff *skb)
1411 skb->transport_header = skb->data - skb->head;
1414 static inline void skb_set_transport_header(struct sk_buff *skb,
1417 skb_reset_transport_header(skb);
1418 skb->transport_header += offset;
1421 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1423 return skb->head + skb->network_header;
1426 static inline void skb_reset_network_header(struct sk_buff *skb)
1428 skb->network_header = skb->data - skb->head;
1431 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1433 skb_reset_network_header(skb);
1434 skb->network_header += offset;
1437 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1439 return skb->head + skb->mac_header;
1442 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1444 return skb->mac_header != ~0U;
1447 static inline void skb_reset_mac_header(struct sk_buff *skb)
1449 skb->mac_header = skb->data - skb->head;
1452 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1454 skb_reset_mac_header(skb);
1455 skb->mac_header += offset;
1458 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1460 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1462 return skb->transport_header;
1465 static inline void skb_reset_transport_header(struct sk_buff *skb)
1467 skb->transport_header = skb->data;
1470 static inline void skb_set_transport_header(struct sk_buff *skb,
1473 skb->transport_header = skb->data + offset;
1476 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1478 return skb->network_header;
1481 static inline void skb_reset_network_header(struct sk_buff *skb)
1483 skb->network_header = skb->data;
1486 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1488 skb->network_header = skb->data + offset;
1491 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1493 return skb->mac_header;
1496 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1498 return skb->mac_header != NULL;
1501 static inline void skb_reset_mac_header(struct sk_buff *skb)
1503 skb->mac_header = skb->data;
1506 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1508 skb->mac_header = skb->data + offset;
1510 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1512 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
1514 if (skb_mac_header_was_set(skb)) {
1515 const unsigned char *old_mac = skb_mac_header(skb);
1517 skb_set_mac_header(skb, -skb->mac_len);
1518 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
1522 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
1524 return skb->csum_start - skb_headroom(skb);
1527 static inline int skb_transport_offset(const struct sk_buff *skb)
1529 return skb_transport_header(skb) - skb->data;
1532 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1534 return skb->transport_header - skb->network_header;
1537 static inline int skb_network_offset(const struct sk_buff *skb)
1539 return skb_network_header(skb) - skb->data;
1542 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
1544 return pskb_may_pull(skb, skb_network_offset(skb) + len);
1548 * CPUs often take a performance hit when accessing unaligned memory
1549 * locations. The actual performance hit varies, it can be small if the
1550 * hardware handles it or large if we have to take an exception and fix it
1553 * Since an ethernet header is 14 bytes network drivers often end up with
1554 * the IP header at an unaligned offset. The IP header can be aligned by
1555 * shifting the start of the packet by 2 bytes. Drivers should do this
1558 * skb_reserve(skb, NET_IP_ALIGN);
1560 * The downside to this alignment of the IP header is that the DMA is now
1561 * unaligned. On some architectures the cost of an unaligned DMA is high
1562 * and this cost outweighs the gains made by aligning the IP header.
1564 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1567 #ifndef NET_IP_ALIGN
1568 #define NET_IP_ALIGN 2
1572 * The networking layer reserves some headroom in skb data (via
1573 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1574 * the header has to grow. In the default case, if the header has to grow
1575 * 32 bytes or less we avoid the reallocation.
1577 * Unfortunately this headroom changes the DMA alignment of the resulting
1578 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1579 * on some architectures. An architecture can override this value,
1580 * perhaps setting it to a cacheline in size (since that will maintain
1581 * cacheline alignment of the DMA). It must be a power of 2.
1583 * Various parts of the networking layer expect at least 32 bytes of
1584 * headroom, you should not reduce this.
1586 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1587 * to reduce average number of cache lines per packet.
1588 * get_rps_cpus() for example only access one 64 bytes aligned block :
1589 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1592 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1595 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1597 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1599 if (unlikely(skb_is_nonlinear(skb))) {
1604 skb_set_tail_pointer(skb, len);
1607 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1609 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1612 return ___pskb_trim(skb, len);
1613 __skb_trim(skb, len);
1617 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1619 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1623 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1624 * @skb: buffer to alter
1627 * This is identical to pskb_trim except that the caller knows that
1628 * the skb is not cloned so we should never get an error due to out-
1631 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1633 int err = pskb_trim(skb, len);
1638 * skb_orphan - orphan a buffer
1639 * @skb: buffer to orphan
1641 * If a buffer currently has an owner then we call the owner's
1642 * destructor function and make the @skb unowned. The buffer continues
1643 * to exist but is no longer charged to its former owner.
1645 static inline void skb_orphan(struct sk_buff *skb)
1647 if (skb->destructor)
1648 skb->destructor(skb);
1649 skb->destructor = NULL;
1654 * __skb_queue_purge - empty a list
1655 * @list: list to empty
1657 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1658 * the list and one reference dropped. This function does not take the
1659 * list lock and the caller must hold the relevant locks to use it.
1661 extern void skb_queue_purge(struct sk_buff_head *list);
1662 static inline void __skb_queue_purge(struct sk_buff_head *list)
1664 struct sk_buff *skb;
1665 while ((skb = __skb_dequeue(list)) != NULL)
1670 * __dev_alloc_skb - allocate an skbuff for receiving
1671 * @length: length to allocate
1672 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1674 * Allocate a new &sk_buff and assign it a usage count of one. The
1675 * buffer has unspecified headroom built in. Users should allocate
1676 * the headroom they think they need without accounting for the
1677 * built in space. The built in space is used for optimisations.
1679 * %NULL is returned if there is no free memory.
1681 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1684 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1686 skb_reserve(skb, NET_SKB_PAD);
1690 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1692 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1693 unsigned int length, gfp_t gfp_mask);
1696 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1697 * @dev: network device to receive on
1698 * @length: length to allocate
1700 * Allocate a new &sk_buff and assign it a usage count of one. The
1701 * buffer has unspecified headroom built in. Users should allocate
1702 * the headroom they think they need without accounting for the
1703 * built in space. The built in space is used for optimisations.
1705 * %NULL is returned if there is no free memory. Although this function
1706 * allocates memory it can be called from an interrupt.
1708 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1709 unsigned int length)
1711 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1714 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
1715 unsigned int length, gfp_t gfp)
1717 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
1719 if (NET_IP_ALIGN && skb)
1720 skb_reserve(skb, NET_IP_ALIGN);
1724 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
1725 unsigned int length)
1727 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
1731 * skb_frag_page - retrieve the page refered to by a paged fragment
1732 * @frag: the paged fragment
1734 * Returns the &struct page associated with @frag.
1736 static inline struct page *skb_frag_page(const skb_frag_t *frag)
1738 return frag->page.p;
1742 * __skb_frag_ref - take an addition reference on a paged fragment.
1743 * @frag: the paged fragment
1745 * Takes an additional reference on the paged fragment @frag.
1747 static inline void __skb_frag_ref(skb_frag_t *frag)
1749 get_page(skb_frag_page(frag));
1753 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
1755 * @f: the fragment offset.
1757 * Takes an additional reference on the @f'th paged fragment of @skb.
1759 static inline void skb_frag_ref(struct sk_buff *skb, int f)
1761 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
1765 * __skb_frag_unref - release a reference on a paged fragment.
1766 * @frag: the paged fragment
1768 * Releases a reference on the paged fragment @frag.
1770 static inline void __skb_frag_unref(skb_frag_t *frag)
1772 put_page(skb_frag_page(frag));
1776 * skb_frag_unref - release a reference on a paged fragment of an skb.
1778 * @f: the fragment offset
1780 * Releases a reference on the @f'th paged fragment of @skb.
1782 static inline void skb_frag_unref(struct sk_buff *skb, int f)
1784 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
1788 * skb_frag_address - gets the address of the data contained in a paged fragment
1789 * @frag: the paged fragment buffer
1791 * Returns the address of the data within @frag. The page must already
1794 static inline void *skb_frag_address(const skb_frag_t *frag)
1796 return page_address(skb_frag_page(frag)) + frag->page_offset;
1800 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
1801 * @frag: the paged fragment buffer
1803 * Returns the address of the data within @frag. Checks that the page
1804 * is mapped and returns %NULL otherwise.
1806 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
1808 void *ptr = page_address(skb_frag_page(frag));
1812 return ptr + frag->page_offset;
1816 * __skb_frag_set_page - sets the page contained in a paged fragment
1817 * @frag: the paged fragment
1818 * @page: the page to set
1820 * Sets the fragment @frag to contain @page.
1822 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
1824 frag->page.p = page;
1828 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
1830 * @f: the fragment offset
1831 * @page: the page to set
1833 * Sets the @f'th fragment of @skb to contain @page.
1835 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
1838 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
1842 * skb_frag_dma_map - maps a paged fragment via the DMA API
1843 * @dev: the device to map the fragment to
1844 * @frag: the paged fragment to map
1845 * @offset: the offset within the fragment (starting at the
1846 * fragment's own offset)
1847 * @size: the number of bytes to map
1848 * @dir: the direction of the mapping (%PCI_DMA_*)
1850 * Maps the page associated with @frag to @device.
1852 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
1853 const skb_frag_t *frag,
1854 size_t offset, size_t size,
1855 enum dma_data_direction dir)
1857 return dma_map_page(dev, skb_frag_page(frag),
1858 frag->page_offset + offset, size, dir);
1861 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
1864 return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
1868 * skb_clone_writable - is the header of a clone writable
1869 * @skb: buffer to check
1870 * @len: length up to which to write
1872 * Returns true if modifying the header part of the cloned buffer
1873 * does not requires the data to be copied.
1875 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
1877 return !skb_header_cloned(skb) &&
1878 skb_headroom(skb) + len <= skb->hdr_len;
1881 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1886 if (headroom < NET_SKB_PAD)
1887 headroom = NET_SKB_PAD;
1888 if (headroom > skb_headroom(skb))
1889 delta = headroom - skb_headroom(skb);
1891 if (delta || cloned)
1892 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1898 * skb_cow - copy header of skb when it is required
1899 * @skb: buffer to cow
1900 * @headroom: needed headroom
1902 * If the skb passed lacks sufficient headroom or its data part
1903 * is shared, data is reallocated. If reallocation fails, an error
1904 * is returned and original skb is not changed.
1906 * The result is skb with writable area skb->head...skb->tail
1907 * and at least @headroom of space at head.
1909 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1911 return __skb_cow(skb, headroom, skb_cloned(skb));
1915 * skb_cow_head - skb_cow but only making the head writable
1916 * @skb: buffer to cow
1917 * @headroom: needed headroom
1919 * This function is identical to skb_cow except that we replace the
1920 * skb_cloned check by skb_header_cloned. It should be used when
1921 * you only need to push on some header and do not need to modify
1924 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1926 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1930 * skb_padto - pad an skbuff up to a minimal size
1931 * @skb: buffer to pad
1932 * @len: minimal length
1934 * Pads up a buffer to ensure the trailing bytes exist and are
1935 * blanked. If the buffer already contains sufficient data it
1936 * is untouched. Otherwise it is extended. Returns zero on
1937 * success. The skb is freed on error.
1940 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1942 unsigned int size = skb->len;
1943 if (likely(size >= len))
1945 return skb_pad(skb, len - size);
1948 static inline int skb_add_data(struct sk_buff *skb,
1949 char __user *from, int copy)
1951 const int off = skb->len;
1953 if (skb->ip_summed == CHECKSUM_NONE) {
1955 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1958 skb->csum = csum_block_add(skb->csum, csum, off);
1961 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1964 __skb_trim(skb, off);
1968 static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
1969 const struct page *page, int off)
1972 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1974 return page == skb_frag_page(frag) &&
1975 off == frag->page_offset + skb_frag_size(frag);
1980 static inline int __skb_linearize(struct sk_buff *skb)
1982 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1986 * skb_linearize - convert paged skb to linear one
1987 * @skb: buffer to linarize
1989 * If there is no free memory -ENOMEM is returned, otherwise zero
1990 * is returned and the old skb data released.
1992 static inline int skb_linearize(struct sk_buff *skb)
1994 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1998 * skb_linearize_cow - make sure skb is linear and writable
1999 * @skb: buffer to process
2001 * If there is no free memory -ENOMEM is returned, otherwise zero
2002 * is returned and the old skb data released.
2004 static inline int skb_linearize_cow(struct sk_buff *skb)
2006 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
2007 __skb_linearize(skb) : 0;
2011 * skb_postpull_rcsum - update checksum for received skb after pull
2012 * @skb: buffer to update
2013 * @start: start of data before pull
2014 * @len: length of data pulled
2016 * After doing a pull on a received packet, you need to call this to
2017 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2018 * CHECKSUM_NONE so that it can be recomputed from scratch.
2021 static inline void skb_postpull_rcsum(struct sk_buff *skb,
2022 const void *start, unsigned int len)
2024 if (skb->ip_summed == CHECKSUM_COMPLETE)
2025 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
2028 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
2031 * pskb_trim_rcsum - trim received skb and update checksum
2032 * @skb: buffer to trim
2035 * This is exactly the same as pskb_trim except that it ensures the
2036 * checksum of received packets are still valid after the operation.
2039 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
2041 if (likely(len >= skb->len))
2043 if (skb->ip_summed == CHECKSUM_COMPLETE)
2044 skb->ip_summed = CHECKSUM_NONE;
2045 return __pskb_trim(skb, len);
2048 #define skb_queue_walk(queue, skb) \
2049 for (skb = (queue)->next; \
2050 skb != (struct sk_buff *)(queue); \
2053 #define skb_queue_walk_safe(queue, skb, tmp) \
2054 for (skb = (queue)->next, tmp = skb->next; \
2055 skb != (struct sk_buff *)(queue); \
2056 skb = tmp, tmp = skb->next)
2058 #define skb_queue_walk_from(queue, skb) \
2059 for (; skb != (struct sk_buff *)(queue); \
2062 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2063 for (tmp = skb->next; \
2064 skb != (struct sk_buff *)(queue); \
2065 skb = tmp, tmp = skb->next)
2067 #define skb_queue_reverse_walk(queue, skb) \
2068 for (skb = (queue)->prev; \
2069 skb != (struct sk_buff *)(queue); \
2072 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2073 for (skb = (queue)->prev, tmp = skb->prev; \
2074 skb != (struct sk_buff *)(queue); \
2075 skb = tmp, tmp = skb->prev)
2077 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2078 for (tmp = skb->prev; \
2079 skb != (struct sk_buff *)(queue); \
2080 skb = tmp, tmp = skb->prev)
2082 static inline bool skb_has_frag_list(const struct sk_buff *skb)
2084 return skb_shinfo(skb)->frag_list != NULL;
2087 static inline void skb_frag_list_init(struct sk_buff *skb)
2089 skb_shinfo(skb)->frag_list = NULL;
2092 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
2094 frag->next = skb_shinfo(skb)->frag_list;
2095 skb_shinfo(skb)->frag_list = frag;
2098 #define skb_walk_frags(skb, iter) \
2099 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2101 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
2102 int *peeked, int *off, int *err);
2103 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
2104 int noblock, int *err);
2105 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
2106 struct poll_table_struct *wait);
2107 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
2108 int offset, struct iovec *to,
2110 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
2113 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
2115 const struct iovec *from,
2118 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from,
2120 const struct iovec *to,
2123 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
2124 extern void skb_free_datagram_locked(struct sock *sk,
2125 struct sk_buff *skb);
2126 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
2127 unsigned int flags);
2128 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
2129 int len, __wsum csum);
2130 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
2132 extern int skb_store_bits(struct sk_buff *skb, int offset,
2133 const void *from, int len);
2134 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
2135 int offset, u8 *to, int len,
2137 extern int skb_splice_bits(struct sk_buff *skb,
2138 unsigned int offset,
2139 struct pipe_inode_info *pipe,
2141 unsigned int flags);
2142 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
2143 extern void skb_split(struct sk_buff *skb,
2144 struct sk_buff *skb1, const u32 len);
2145 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
2148 extern struct sk_buff *skb_segment(struct sk_buff *skb,
2149 netdev_features_t features);
2151 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
2152 int len, void *buffer)
2154 int hlen = skb_headlen(skb);
2156 if (hlen - offset >= len)
2157 return skb->data + offset;
2159 if (skb_copy_bits(skb, offset, buffer, len) < 0)
2165 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
2167 const unsigned int len)
2169 memcpy(to, skb->data, len);
2172 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
2173 const int offset, void *to,
2174 const unsigned int len)
2176 memcpy(to, skb->data + offset, len);
2179 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
2181 const unsigned int len)
2183 memcpy(skb->data, from, len);
2186 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
2189 const unsigned int len)
2191 memcpy(skb->data + offset, from, len);
2194 extern void skb_init(void);
2196 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
2202 * skb_get_timestamp - get timestamp from a skb
2203 * @skb: skb to get stamp from
2204 * @stamp: pointer to struct timeval to store stamp in
2206 * Timestamps are stored in the skb as offsets to a base timestamp.
2207 * This function converts the offset back to a struct timeval and stores
2210 static inline void skb_get_timestamp(const struct sk_buff *skb,
2211 struct timeval *stamp)
2213 *stamp = ktime_to_timeval(skb->tstamp);
2216 static inline void skb_get_timestampns(const struct sk_buff *skb,
2217 struct timespec *stamp)
2219 *stamp = ktime_to_timespec(skb->tstamp);
2222 static inline void __net_timestamp(struct sk_buff *skb)
2224 skb->tstamp = ktime_get_real();
2227 static inline ktime_t net_timedelta(ktime_t t)
2229 return ktime_sub(ktime_get_real(), t);
2232 static inline ktime_t net_invalid_timestamp(void)
2234 return ktime_set(0, 0);
2237 extern void skb_timestamping_init(void);
2239 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2241 extern void skb_clone_tx_timestamp(struct sk_buff *skb);
2242 extern bool skb_defer_rx_timestamp(struct sk_buff *skb);
2244 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2246 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
2250 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
2255 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2258 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2260 * PHY drivers may accept clones of transmitted packets for
2261 * timestamping via their phy_driver.txtstamp method. These drivers
2262 * must call this function to return the skb back to the stack, with
2263 * or without a timestamp.
2265 * @skb: clone of the the original outgoing packet
2266 * @hwtstamps: hardware time stamps, may be NULL if not available
2269 void skb_complete_tx_timestamp(struct sk_buff *skb,
2270 struct skb_shared_hwtstamps *hwtstamps);
2273 * skb_tstamp_tx - queue clone of skb with send time stamps
2274 * @orig_skb: the original outgoing packet
2275 * @hwtstamps: hardware time stamps, may be NULL if not available
2277 * If the skb has a socket associated, then this function clones the
2278 * skb (thus sharing the actual data and optional structures), stores
2279 * the optional hardware time stamping information (if non NULL) or
2280 * generates a software time stamp (otherwise), then queues the clone
2281 * to the error queue of the socket. Errors are silently ignored.
2283 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
2284 struct skb_shared_hwtstamps *hwtstamps);
2286 static inline void sw_tx_timestamp(struct sk_buff *skb)
2288 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP &&
2289 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
2290 skb_tstamp_tx(skb, NULL);
2294 * skb_tx_timestamp() - Driver hook for transmit timestamping
2296 * Ethernet MAC Drivers should call this function in their hard_xmit()
2297 * function immediately before giving the sk_buff to the MAC hardware.
2299 * @skb: A socket buffer.
2301 static inline void skb_tx_timestamp(struct sk_buff *skb)
2303 skb_clone_tx_timestamp(skb);
2304 sw_tx_timestamp(skb);
2308 * skb_complete_wifi_ack - deliver skb with wifi status
2310 * @skb: the original outgoing packet
2311 * @acked: ack status
2314 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
2316 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
2317 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
2319 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
2321 return skb->ip_summed & CHECKSUM_UNNECESSARY;
2325 * skb_checksum_complete - Calculate checksum of an entire packet
2326 * @skb: packet to process
2328 * This function calculates the checksum over the entire packet plus
2329 * the value of skb->csum. The latter can be used to supply the
2330 * checksum of a pseudo header as used by TCP/UDP. It returns the
2333 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2334 * this function can be used to verify that checksum on received
2335 * packets. In that case the function should return zero if the
2336 * checksum is correct. In particular, this function will return zero
2337 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2338 * hardware has already verified the correctness of the checksum.
2340 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
2342 return skb_csum_unnecessary(skb) ?
2343 0 : __skb_checksum_complete(skb);
2346 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2347 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
2348 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
2350 if (nfct && atomic_dec_and_test(&nfct->use))
2351 nf_conntrack_destroy(nfct);
2353 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
2356 atomic_inc(&nfct->use);
2359 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2360 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
2363 atomic_inc(&skb->users);
2365 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
2371 #ifdef CONFIG_BRIDGE_NETFILTER
2372 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
2374 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
2377 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
2380 atomic_inc(&nf_bridge->use);
2382 #endif /* CONFIG_BRIDGE_NETFILTER */
2383 static inline void nf_reset(struct sk_buff *skb)
2385 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2386 nf_conntrack_put(skb->nfct);
2389 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2390 nf_conntrack_put_reasm(skb->nfct_reasm);
2391 skb->nfct_reasm = NULL;
2393 #ifdef CONFIG_BRIDGE_NETFILTER
2394 nf_bridge_put(skb->nf_bridge);
2395 skb->nf_bridge = NULL;
2399 /* Note: This doesn't put any conntrack and bridge info in dst. */
2400 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2402 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2403 dst->nfct = src->nfct;
2404 nf_conntrack_get(src->nfct);
2405 dst->nfctinfo = src->nfctinfo;
2407 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2408 dst->nfct_reasm = src->nfct_reasm;
2409 nf_conntrack_get_reasm(src->nfct_reasm);
2411 #ifdef CONFIG_BRIDGE_NETFILTER
2412 dst->nf_bridge = src->nf_bridge;
2413 nf_bridge_get(src->nf_bridge);
2417 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2419 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2420 nf_conntrack_put(dst->nfct);
2422 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2423 nf_conntrack_put_reasm(dst->nfct_reasm);
2425 #ifdef CONFIG_BRIDGE_NETFILTER
2426 nf_bridge_put(dst->nf_bridge);
2428 __nf_copy(dst, src);
2431 #ifdef CONFIG_NETWORK_SECMARK
2432 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2434 to->secmark = from->secmark;
2437 static inline void skb_init_secmark(struct sk_buff *skb)
2442 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2445 static inline void skb_init_secmark(struct sk_buff *skb)
2449 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
2451 skb->queue_mapping = queue_mapping;
2454 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
2456 return skb->queue_mapping;
2459 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
2461 to->queue_mapping = from->queue_mapping;
2464 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
2466 skb->queue_mapping = rx_queue + 1;
2469 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2471 return skb->queue_mapping - 1;
2474 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2476 return skb->queue_mapping != 0;
2479 extern u16 __skb_tx_hash(const struct net_device *dev,
2480 const struct sk_buff *skb,
2481 unsigned int num_tx_queues);
2484 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2489 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2495 static inline bool skb_is_gso(const struct sk_buff *skb)
2497 return skb_shinfo(skb)->gso_size;
2500 static inline bool skb_is_gso_v6(const struct sk_buff *skb)
2502 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2505 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2507 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2509 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2510 * wanted then gso_type will be set. */
2511 const struct skb_shared_info *shinfo = skb_shinfo(skb);
2513 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
2514 unlikely(shinfo->gso_type == 0)) {
2515 __skb_warn_lro_forwarding(skb);
2521 static inline void skb_forward_csum(struct sk_buff *skb)
2523 /* Unfortunately we don't support this one. Any brave souls? */
2524 if (skb->ip_summed == CHECKSUM_COMPLETE)
2525 skb->ip_summed = CHECKSUM_NONE;
2529 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
2530 * @skb: skb to check
2532 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
2533 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
2534 * use this helper, to document places where we make this assertion.
2536 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
2539 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
2543 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2545 static inline bool skb_is_recycleable(const struct sk_buff *skb, int skb_size)
2547 if (irqs_disabled())
2550 if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY)
2553 if (skb_is_nonlinear(skb) || skb->fclone != SKB_FCLONE_UNAVAILABLE)
2556 skb_size = SKB_DATA_ALIGN(skb_size + NET_SKB_PAD);
2557 if (skb_end_pointer(skb) - skb->head < skb_size)
2560 if (skb_shared(skb) || skb_cloned(skb))
2565 #endif /* __KERNEL__ */
2566 #endif /* _LINUX_SKBUFF_H */