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 /* device driver supports TX zero-copy buffers */
229 SKBTX_DEV_ZEROCOPY = 1 << 3,
231 /* generate wifi status information (where possible) */
232 SKBTX_WIFI_STATUS = 1 << 4,
236 * The callback notifies userspace to release buffers when skb DMA is done in
237 * lower device, the skb last reference should be 0 when calling this.
238 * The zerocopy_success argument is true if zero copy transmit occurred,
239 * false on data copy or out of memory error caused by data copy attempt.
240 * The ctx field is used to track device context.
241 * The desc field is used to track userspace buffer index.
244 void (*callback)(struct ubuf_info *, bool zerocopy_success);
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;
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>
508 #define SKB_ALLOC_FCLONE 0x01
509 #define SKB_ALLOC_RX 0x02
511 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
512 static inline bool skb_pfmemalloc(const struct sk_buff *skb)
514 return unlikely(skb->pfmemalloc);
518 * skb might have a dst pointer attached, refcounted or not.
519 * _skb_refdst low order bit is set if refcount was _not_ taken
521 #define SKB_DST_NOREF 1UL
522 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
525 * skb_dst - returns skb dst_entry
528 * Returns skb dst_entry, regardless of reference taken or not.
530 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
532 /* If refdst was not refcounted, check we still are in a
533 * rcu_read_lock section
535 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
536 !rcu_read_lock_held() &&
537 !rcu_read_lock_bh_held());
538 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
542 * skb_dst_set - sets skb dst
546 * Sets skb dst, assuming a reference was taken on dst and should
547 * be released by skb_dst_drop()
549 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
551 skb->_skb_refdst = (unsigned long)dst;
554 extern void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst);
557 * skb_dst_is_noref - Test if skb dst isn't refcounted
560 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
562 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
565 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
567 return (struct rtable *)skb_dst(skb);
570 extern void kfree_skb(struct sk_buff *skb);
571 extern void consume_skb(struct sk_buff *skb);
572 extern void __kfree_skb(struct sk_buff *skb);
573 extern struct kmem_cache *skbuff_head_cache;
575 extern void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
576 extern bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
577 bool *fragstolen, int *delta_truesize);
579 extern struct sk_buff *__alloc_skb(unsigned int size,
580 gfp_t priority, int flags, int node);
581 extern struct sk_buff *build_skb(void *data, unsigned int frag_size);
582 static inline struct sk_buff *alloc_skb(unsigned int size,
585 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
588 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
591 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
594 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
595 extern int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
596 extern struct sk_buff *skb_clone(struct sk_buff *skb,
598 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
600 extern struct sk_buff *__pskb_copy(struct sk_buff *skb,
601 int headroom, gfp_t gfp_mask);
603 extern int pskb_expand_head(struct sk_buff *skb,
604 int nhead, int ntail,
606 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
607 unsigned int headroom);
608 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
609 int newheadroom, int newtailroom,
611 extern int skb_to_sgvec(struct sk_buff *skb,
612 struct scatterlist *sg, int offset,
614 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
615 struct sk_buff **trailer);
616 extern int skb_pad(struct sk_buff *skb, int pad);
617 #define dev_kfree_skb(a) consume_skb(a)
619 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
620 int getfrag(void *from, char *to, int offset,
621 int len,int odd, struct sk_buff *skb),
622 void *from, int length);
624 struct skb_seq_state {
628 __u32 stepped_offset;
629 struct sk_buff *root_skb;
630 struct sk_buff *cur_skb;
634 extern void skb_prepare_seq_read(struct sk_buff *skb,
635 unsigned int from, unsigned int to,
636 struct skb_seq_state *st);
637 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
638 struct skb_seq_state *st);
639 extern void skb_abort_seq_read(struct skb_seq_state *st);
641 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
642 unsigned int to, struct ts_config *config,
643 struct ts_state *state);
645 extern void __skb_get_rxhash(struct sk_buff *skb);
646 static inline __u32 skb_get_rxhash(struct sk_buff *skb)
649 __skb_get_rxhash(skb);
654 #ifdef NET_SKBUFF_DATA_USES_OFFSET
655 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
657 return skb->head + skb->end;
660 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
665 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
670 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
672 return skb->end - skb->head;
677 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
679 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
681 return &skb_shinfo(skb)->hwtstamps;
685 * skb_queue_empty - check if a queue is empty
688 * Returns true if the queue is empty, false otherwise.
690 static inline int skb_queue_empty(const struct sk_buff_head *list)
692 return list->next == (struct sk_buff *)list;
696 * skb_queue_is_last - check if skb is the last entry in the queue
700 * Returns true if @skb is the last buffer on the list.
702 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
703 const struct sk_buff *skb)
705 return skb->next == (struct sk_buff *)list;
709 * skb_queue_is_first - check if skb is the first entry in the queue
713 * Returns true if @skb is the first buffer on the list.
715 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
716 const struct sk_buff *skb)
718 return skb->prev == (struct sk_buff *)list;
722 * skb_queue_next - return the next packet in the queue
724 * @skb: current buffer
726 * Return the next packet in @list after @skb. It is only valid to
727 * call this if skb_queue_is_last() evaluates to false.
729 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
730 const struct sk_buff *skb)
732 /* This BUG_ON may seem severe, but if we just return then we
733 * are going to dereference garbage.
735 BUG_ON(skb_queue_is_last(list, skb));
740 * skb_queue_prev - return the prev packet in the queue
742 * @skb: current buffer
744 * Return the prev packet in @list before @skb. It is only valid to
745 * call this if skb_queue_is_first() evaluates to false.
747 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
748 const struct sk_buff *skb)
750 /* This BUG_ON may seem severe, but if we just return then we
751 * are going to dereference garbage.
753 BUG_ON(skb_queue_is_first(list, skb));
758 * skb_get - reference buffer
759 * @skb: buffer to reference
761 * Makes another reference to a socket buffer and returns a pointer
764 static inline struct sk_buff *skb_get(struct sk_buff *skb)
766 atomic_inc(&skb->users);
771 * If users == 1, we are the only owner and are can avoid redundant
776 * skb_cloned - is the buffer a clone
777 * @skb: buffer to check
779 * Returns true if the buffer was generated with skb_clone() and is
780 * one of multiple shared copies of the buffer. Cloned buffers are
781 * shared data so must not be written to under normal circumstances.
783 static inline int skb_cloned(const struct sk_buff *skb)
785 return skb->cloned &&
786 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
790 * skb_header_cloned - is the header a clone
791 * @skb: buffer to check
793 * Returns true if modifying the header part of the buffer requires
794 * the data to be copied.
796 static inline int skb_header_cloned(const struct sk_buff *skb)
803 dataref = atomic_read(&skb_shinfo(skb)->dataref);
804 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
809 * skb_header_release - release reference to header
810 * @skb: buffer to operate on
812 * Drop a reference to the header part of the buffer. This is done
813 * by acquiring a payload reference. You must not read from the header
814 * part of skb->data after this.
816 static inline void skb_header_release(struct sk_buff *skb)
820 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
824 * skb_shared - is the buffer shared
825 * @skb: buffer to check
827 * Returns true if more than one person has a reference to this
830 static inline int skb_shared(const struct sk_buff *skb)
832 return atomic_read(&skb->users) != 1;
836 * skb_share_check - check if buffer is shared and if so clone it
837 * @skb: buffer to check
838 * @pri: priority for memory allocation
840 * If the buffer is shared the buffer is cloned and the old copy
841 * drops a reference. A new clone with a single reference is returned.
842 * If the buffer is not shared the original buffer is returned. When
843 * being called from interrupt status or with spinlocks held pri must
846 * NULL is returned on a memory allocation failure.
848 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
850 might_sleep_if(pri & __GFP_WAIT);
851 if (skb_shared(skb)) {
852 struct sk_buff *nskb = skb_clone(skb, pri);
864 * Copy shared buffers into a new sk_buff. We effectively do COW on
865 * packets to handle cases where we have a local reader and forward
866 * and a couple of other messy ones. The normal one is tcpdumping
867 * a packet thats being forwarded.
871 * skb_unshare - make a copy of a shared buffer
872 * @skb: buffer to check
873 * @pri: priority for memory allocation
875 * If the socket buffer is a clone then this function creates a new
876 * copy of the data, drops a reference count on the old copy and returns
877 * the new copy with the reference count at 1. If the buffer is not a clone
878 * the original buffer is returned. When called with a spinlock held or
879 * from interrupt state @pri must be %GFP_ATOMIC
881 * %NULL is returned on a memory allocation failure.
883 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
886 might_sleep_if(pri & __GFP_WAIT);
887 if (skb_cloned(skb)) {
888 struct sk_buff *nskb = skb_copy(skb, pri);
889 kfree_skb(skb); /* Free our shared copy */
896 * skb_peek - peek at the head of an &sk_buff_head
897 * @list_: list to peek at
899 * Peek an &sk_buff. Unlike most other operations you _MUST_
900 * be careful with this one. A peek leaves the buffer on the
901 * list and someone else may run off with it. You must hold
902 * the appropriate locks or have a private queue to do this.
904 * Returns %NULL for an empty list or a pointer to the head element.
905 * The reference count is not incremented and the reference is therefore
906 * volatile. Use with caution.
908 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
910 struct sk_buff *skb = list_->next;
912 if (skb == (struct sk_buff *)list_)
918 * skb_peek_next - peek skb following the given one from a queue
919 * @skb: skb to start from
920 * @list_: list to peek at
922 * Returns %NULL when the end of the list is met or a pointer to the
923 * next element. The reference count is not incremented and the
924 * reference is therefore volatile. Use with caution.
926 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
927 const struct sk_buff_head *list_)
929 struct sk_buff *next = skb->next;
931 if (next == (struct sk_buff *)list_)
937 * skb_peek_tail - peek at the tail of an &sk_buff_head
938 * @list_: list to peek at
940 * Peek an &sk_buff. Unlike most other operations you _MUST_
941 * be careful with this one. A peek leaves the buffer on the
942 * list and someone else may run off with it. You must hold
943 * the appropriate locks or have a private queue to do this.
945 * Returns %NULL for an empty list or a pointer to the tail element.
946 * The reference count is not incremented and the reference is therefore
947 * volatile. Use with caution.
949 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
951 struct sk_buff *skb = list_->prev;
953 if (skb == (struct sk_buff *)list_)
960 * skb_queue_len - get queue length
961 * @list_: list to measure
963 * Return the length of an &sk_buff queue.
965 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
971 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
972 * @list: queue to initialize
974 * This initializes only the list and queue length aspects of
975 * an sk_buff_head object. This allows to initialize the list
976 * aspects of an sk_buff_head without reinitializing things like
977 * the spinlock. It can also be used for on-stack sk_buff_head
978 * objects where the spinlock is known to not be used.
980 static inline void __skb_queue_head_init(struct sk_buff_head *list)
982 list->prev = list->next = (struct sk_buff *)list;
987 * This function creates a split out lock class for each invocation;
988 * this is needed for now since a whole lot of users of the skb-queue
989 * infrastructure in drivers have different locking usage (in hardirq)
990 * than the networking core (in softirq only). In the long run either the
991 * network layer or drivers should need annotation to consolidate the
992 * main types of usage into 3 classes.
994 static inline void skb_queue_head_init(struct sk_buff_head *list)
996 spin_lock_init(&list->lock);
997 __skb_queue_head_init(list);
1000 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
1001 struct lock_class_key *class)
1003 skb_queue_head_init(list);
1004 lockdep_set_class(&list->lock, class);
1008 * Insert an sk_buff on a list.
1010 * The "__skb_xxxx()" functions are the non-atomic ones that
1011 * can only be called with interrupts disabled.
1013 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
1014 static inline void __skb_insert(struct sk_buff *newsk,
1015 struct sk_buff *prev, struct sk_buff *next,
1016 struct sk_buff_head *list)
1020 next->prev = prev->next = newsk;
1024 static inline void __skb_queue_splice(const struct sk_buff_head *list,
1025 struct sk_buff *prev,
1026 struct sk_buff *next)
1028 struct sk_buff *first = list->next;
1029 struct sk_buff *last = list->prev;
1039 * skb_queue_splice - join two skb lists, this is designed for stacks
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(const struct sk_buff_head *list,
1044 struct sk_buff_head *head)
1046 if (!skb_queue_empty(list)) {
1047 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1048 head->qlen += list->qlen;
1053 * skb_queue_splice_init - 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 * The list at @list is reinitialised
1059 static inline void skb_queue_splice_init(struct sk_buff_head *list,
1060 struct sk_buff_head *head)
1062 if (!skb_queue_empty(list)) {
1063 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1064 head->qlen += list->qlen;
1065 __skb_queue_head_init(list);
1070 * skb_queue_splice_tail - join two skb lists, each list being a queue
1071 * @list: the new list to add
1072 * @head: the place to add it in the first list
1074 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1075 struct sk_buff_head *head)
1077 if (!skb_queue_empty(list)) {
1078 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1079 head->qlen += list->qlen;
1084 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1085 * @list: the new list to add
1086 * @head: the place to add it in the first list
1088 * Each of the lists is a queue.
1089 * The list at @list is reinitialised
1091 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
1092 struct sk_buff_head *head)
1094 if (!skb_queue_empty(list)) {
1095 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1096 head->qlen += list->qlen;
1097 __skb_queue_head_init(list);
1102 * __skb_queue_after - queue a buffer at the list head
1103 * @list: list to use
1104 * @prev: place after this buffer
1105 * @newsk: buffer to queue
1107 * Queue a buffer int the middle of a list. This function takes no locks
1108 * and you must therefore hold required locks before calling it.
1110 * A buffer cannot be placed on two lists at the same time.
1112 static inline void __skb_queue_after(struct sk_buff_head *list,
1113 struct sk_buff *prev,
1114 struct sk_buff *newsk)
1116 __skb_insert(newsk, prev, prev->next, list);
1119 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
1120 struct sk_buff_head *list);
1122 static inline void __skb_queue_before(struct sk_buff_head *list,
1123 struct sk_buff *next,
1124 struct sk_buff *newsk)
1126 __skb_insert(newsk, next->prev, next, list);
1130 * __skb_queue_head - queue a buffer at the list head
1131 * @list: list to use
1132 * @newsk: buffer to queue
1134 * Queue a buffer at the start of a list. This function takes no locks
1135 * and you must therefore hold required locks before calling it.
1137 * A buffer cannot be placed on two lists at the same time.
1139 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
1140 static inline void __skb_queue_head(struct sk_buff_head *list,
1141 struct sk_buff *newsk)
1143 __skb_queue_after(list, (struct sk_buff *)list, newsk);
1147 * __skb_queue_tail - queue a buffer at the list tail
1148 * @list: list to use
1149 * @newsk: buffer to queue
1151 * Queue a buffer at the end of a list. This function takes no locks
1152 * and you must therefore hold required locks before calling it.
1154 * A buffer cannot be placed on two lists at the same time.
1156 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
1157 static inline void __skb_queue_tail(struct sk_buff_head *list,
1158 struct sk_buff *newsk)
1160 __skb_queue_before(list, (struct sk_buff *)list, newsk);
1164 * remove sk_buff from list. _Must_ be called atomically, and with
1167 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
1168 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
1170 struct sk_buff *next, *prev;
1175 skb->next = skb->prev = NULL;
1181 * __skb_dequeue - remove from the head of the queue
1182 * @list: list to dequeue from
1184 * Remove the head of the list. This function does not take any locks
1185 * so must be used with appropriate locks held only. The head item is
1186 * returned or %NULL if the list is empty.
1188 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1189 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1191 struct sk_buff *skb = skb_peek(list);
1193 __skb_unlink(skb, list);
1198 * __skb_dequeue_tail - remove from the tail of the queue
1199 * @list: list to dequeue from
1201 * Remove the tail of the list. This function does not take any locks
1202 * so must be used with appropriate locks held only. The tail item is
1203 * returned or %NULL if the list is empty.
1205 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1206 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1208 struct sk_buff *skb = skb_peek_tail(list);
1210 __skb_unlink(skb, list);
1215 static inline bool skb_is_nonlinear(const struct sk_buff *skb)
1217 return skb->data_len;
1220 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1222 return skb->len - skb->data_len;
1225 static inline int skb_pagelen(const struct sk_buff *skb)
1229 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1230 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
1231 return len + skb_headlen(skb);
1235 * __skb_fill_page_desc - initialise a paged fragment in an skb
1236 * @skb: buffer containing fragment to be initialised
1237 * @i: paged fragment index to initialise
1238 * @page: the page to use for this fragment
1239 * @off: the offset to the data with @page
1240 * @size: the length of the data
1242 * Initialises the @i'th fragment of @skb to point to &size bytes at
1243 * offset @off within @page.
1245 * Does not take any additional reference on the fragment.
1247 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
1248 struct page *page, int off, int size)
1250 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1253 * Propagate page->pfmemalloc to the skb if we can. The problem is
1254 * that not all callers have unique ownership of the page. If
1255 * pfmemalloc is set, we check the mapping as a mapping implies
1256 * page->index is set (index and pfmemalloc share space).
1257 * If it's a valid mapping, we cannot use page->pfmemalloc but we
1258 * do not lose pfmemalloc information as the pages would not be
1259 * allocated using __GFP_MEMALLOC.
1261 if (page->pfmemalloc && !page->mapping)
1262 skb->pfmemalloc = true;
1263 frag->page.p = page;
1264 frag->page_offset = off;
1265 skb_frag_size_set(frag, size);
1269 * skb_fill_page_desc - initialise a paged fragment in an skb
1270 * @skb: buffer containing fragment to be initialised
1271 * @i: paged fragment index to initialise
1272 * @page: the page to use for this fragment
1273 * @off: the offset to the data with @page
1274 * @size: the length of the data
1276 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1277 * @skb to point to &size bytes at offset @off within @page. In
1278 * addition updates @skb such that @i is the last fragment.
1280 * Does not take any additional reference on the fragment.
1282 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1283 struct page *page, int off, int size)
1285 __skb_fill_page_desc(skb, i, page, off, size);
1286 skb_shinfo(skb)->nr_frags = i + 1;
1289 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1290 int off, int size, unsigned int truesize);
1292 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1293 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1294 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1296 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1297 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1299 return skb->head + skb->tail;
1302 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1304 skb->tail = skb->data - skb->head;
1307 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1309 skb_reset_tail_pointer(skb);
1310 skb->tail += offset;
1312 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1313 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1318 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1320 skb->tail = skb->data;
1323 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1325 skb->tail = skb->data + offset;
1328 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1331 * Add data to an sk_buff
1333 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1334 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1336 unsigned char *tmp = skb_tail_pointer(skb);
1337 SKB_LINEAR_ASSERT(skb);
1343 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1344 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1351 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1352 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1355 BUG_ON(skb->len < skb->data_len);
1356 return skb->data += len;
1359 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len)
1361 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
1364 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1366 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1368 if (len > skb_headlen(skb) &&
1369 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1372 return skb->data += len;
1375 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1377 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1380 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1382 if (likely(len <= skb_headlen(skb)))
1384 if (unlikely(len > skb->len))
1386 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1390 * skb_headroom - bytes at buffer head
1391 * @skb: buffer to check
1393 * Return the number of bytes of free space at the head of an &sk_buff.
1395 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1397 return skb->data - skb->head;
1401 * skb_tailroom - bytes at buffer end
1402 * @skb: buffer to check
1404 * Return the number of bytes of free space at the tail of an sk_buff
1406 static inline int skb_tailroom(const struct sk_buff *skb)
1408 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1412 * skb_availroom - bytes at buffer end
1413 * @skb: buffer to check
1415 * Return the number of bytes of free space at the tail of an sk_buff
1416 * allocated by sk_stream_alloc()
1418 static inline int skb_availroom(const struct sk_buff *skb)
1420 return skb_is_nonlinear(skb) ? 0 : skb->avail_size - skb->len;
1424 * skb_reserve - adjust headroom
1425 * @skb: buffer to alter
1426 * @len: bytes to move
1428 * Increase the headroom of an empty &sk_buff by reducing the tail
1429 * room. This is only allowed for an empty buffer.
1431 static inline void skb_reserve(struct sk_buff *skb, int len)
1437 static inline void skb_reset_mac_len(struct sk_buff *skb)
1439 skb->mac_len = skb->network_header - skb->mac_header;
1442 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1443 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1445 return skb->head + skb->transport_header;
1448 static inline void skb_reset_transport_header(struct sk_buff *skb)
1450 skb->transport_header = skb->data - skb->head;
1453 static inline void skb_set_transport_header(struct sk_buff *skb,
1456 skb_reset_transport_header(skb);
1457 skb->transport_header += offset;
1460 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1462 return skb->head + skb->network_header;
1465 static inline void skb_reset_network_header(struct sk_buff *skb)
1467 skb->network_header = skb->data - skb->head;
1470 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1472 skb_reset_network_header(skb);
1473 skb->network_header += offset;
1476 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1478 return skb->head + skb->mac_header;
1481 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1483 return skb->mac_header != ~0U;
1486 static inline void skb_reset_mac_header(struct sk_buff *skb)
1488 skb->mac_header = skb->data - skb->head;
1491 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1493 skb_reset_mac_header(skb);
1494 skb->mac_header += offset;
1497 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1499 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1501 return skb->transport_header;
1504 static inline void skb_reset_transport_header(struct sk_buff *skb)
1506 skb->transport_header = skb->data;
1509 static inline void skb_set_transport_header(struct sk_buff *skb,
1512 skb->transport_header = skb->data + offset;
1515 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1517 return skb->network_header;
1520 static inline void skb_reset_network_header(struct sk_buff *skb)
1522 skb->network_header = skb->data;
1525 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1527 skb->network_header = skb->data + offset;
1530 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1532 return skb->mac_header;
1535 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1537 return skb->mac_header != NULL;
1540 static inline void skb_reset_mac_header(struct sk_buff *skb)
1542 skb->mac_header = skb->data;
1545 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1547 skb->mac_header = skb->data + offset;
1549 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1551 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
1553 if (skb_mac_header_was_set(skb)) {
1554 const unsigned char *old_mac = skb_mac_header(skb);
1556 skb_set_mac_header(skb, -skb->mac_len);
1557 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
1561 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
1563 return skb->csum_start - skb_headroom(skb);
1566 static inline int skb_transport_offset(const struct sk_buff *skb)
1568 return skb_transport_header(skb) - skb->data;
1571 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1573 return skb->transport_header - skb->network_header;
1576 static inline int skb_network_offset(const struct sk_buff *skb)
1578 return skb_network_header(skb) - skb->data;
1581 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
1583 return pskb_may_pull(skb, skb_network_offset(skb) + len);
1587 * CPUs often take a performance hit when accessing unaligned memory
1588 * locations. The actual performance hit varies, it can be small if the
1589 * hardware handles it or large if we have to take an exception and fix it
1592 * Since an ethernet header is 14 bytes network drivers often end up with
1593 * the IP header at an unaligned offset. The IP header can be aligned by
1594 * shifting the start of the packet by 2 bytes. Drivers should do this
1597 * skb_reserve(skb, NET_IP_ALIGN);
1599 * The downside to this alignment of the IP header is that the DMA is now
1600 * unaligned. On some architectures the cost of an unaligned DMA is high
1601 * and this cost outweighs the gains made by aligning the IP header.
1603 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1606 #ifndef NET_IP_ALIGN
1607 #define NET_IP_ALIGN 2
1611 * The networking layer reserves some headroom in skb data (via
1612 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1613 * the header has to grow. In the default case, if the header has to grow
1614 * 32 bytes or less we avoid the reallocation.
1616 * Unfortunately this headroom changes the DMA alignment of the resulting
1617 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1618 * on some architectures. An architecture can override this value,
1619 * perhaps setting it to a cacheline in size (since that will maintain
1620 * cacheline alignment of the DMA). It must be a power of 2.
1622 * Various parts of the networking layer expect at least 32 bytes of
1623 * headroom, you should not reduce this.
1625 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1626 * to reduce average number of cache lines per packet.
1627 * get_rps_cpus() for example only access one 64 bytes aligned block :
1628 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1631 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1634 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1636 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1638 if (unlikely(skb_is_nonlinear(skb))) {
1643 skb_set_tail_pointer(skb, len);
1646 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1648 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1651 return ___pskb_trim(skb, len);
1652 __skb_trim(skb, len);
1656 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1658 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1662 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1663 * @skb: buffer to alter
1666 * This is identical to pskb_trim except that the caller knows that
1667 * the skb is not cloned so we should never get an error due to out-
1670 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1672 int err = pskb_trim(skb, len);
1677 * skb_orphan - orphan a buffer
1678 * @skb: buffer to orphan
1680 * If a buffer currently has an owner then we call the owner's
1681 * destructor function and make the @skb unowned. The buffer continues
1682 * to exist but is no longer charged to its former owner.
1684 static inline void skb_orphan(struct sk_buff *skb)
1686 if (skb->destructor)
1687 skb->destructor(skb);
1688 skb->destructor = NULL;
1693 * skb_orphan_frags - orphan the frags contained in a buffer
1694 * @skb: buffer to orphan frags from
1695 * @gfp_mask: allocation mask for replacement pages
1697 * For each frag in the SKB which needs a destructor (i.e. has an
1698 * owner) create a copy of that frag and release the original
1699 * page by calling the destructor.
1701 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
1703 if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY)))
1705 return skb_copy_ubufs(skb, gfp_mask);
1709 * __skb_queue_purge - empty a list
1710 * @list: list to empty
1712 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1713 * the list and one reference dropped. This function does not take the
1714 * list lock and the caller must hold the relevant locks to use it.
1716 extern void skb_queue_purge(struct sk_buff_head *list);
1717 static inline void __skb_queue_purge(struct sk_buff_head *list)
1719 struct sk_buff *skb;
1720 while ((skb = __skb_dequeue(list)) != NULL)
1724 extern void *netdev_alloc_frag(unsigned int fragsz);
1726 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1727 unsigned int length,
1731 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1732 * @dev: network device to receive on
1733 * @length: length to allocate
1735 * Allocate a new &sk_buff and assign it a usage count of one. The
1736 * buffer has unspecified headroom built in. Users should allocate
1737 * the headroom they think they need without accounting for the
1738 * built in space. The built in space is used for optimisations.
1740 * %NULL is returned if there is no free memory. Although this function
1741 * allocates memory it can be called from an interrupt.
1743 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1744 unsigned int length)
1746 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1749 /* legacy helper around __netdev_alloc_skb() */
1750 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1753 return __netdev_alloc_skb(NULL, length, gfp_mask);
1756 /* legacy helper around netdev_alloc_skb() */
1757 static inline struct sk_buff *dev_alloc_skb(unsigned int length)
1759 return netdev_alloc_skb(NULL, length);
1763 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
1764 unsigned int length, gfp_t gfp)
1766 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
1768 if (NET_IP_ALIGN && skb)
1769 skb_reserve(skb, NET_IP_ALIGN);
1773 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
1774 unsigned int length)
1776 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
1780 * __skb_alloc_page - allocate pages for ps-rx on a skb and preserve pfmemalloc data
1781 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
1782 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
1783 * @order: size of the allocation
1785 * Allocate a new page.
1787 * %NULL is returned if there is no free memory.
1789 static inline struct page *__skb_alloc_pages(gfp_t gfp_mask,
1790 struct sk_buff *skb,
1795 gfp_mask |= __GFP_COLD;
1797 if (!(gfp_mask & __GFP_NOMEMALLOC))
1798 gfp_mask |= __GFP_MEMALLOC;
1800 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
1801 if (skb && page && page->pfmemalloc)
1802 skb->pfmemalloc = true;
1808 * __skb_alloc_page - allocate a page for ps-rx for a given skb and preserve pfmemalloc data
1809 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
1810 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
1812 * Allocate a new page.
1814 * %NULL is returned if there is no free memory.
1816 static inline struct page *__skb_alloc_page(gfp_t gfp_mask,
1817 struct sk_buff *skb)
1819 return __skb_alloc_pages(gfp_mask, skb, 0);
1823 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
1824 * @page: The page that was allocated from skb_alloc_page
1825 * @skb: The skb that may need pfmemalloc set
1827 static inline void skb_propagate_pfmemalloc(struct page *page,
1828 struct sk_buff *skb)
1830 if (page && page->pfmemalloc)
1831 skb->pfmemalloc = true;
1835 * skb_frag_page - retrieve the page refered to by a paged fragment
1836 * @frag: the paged fragment
1838 * Returns the &struct page associated with @frag.
1840 static inline struct page *skb_frag_page(const skb_frag_t *frag)
1842 return frag->page.p;
1846 * __skb_frag_ref - take an addition reference on a paged fragment.
1847 * @frag: the paged fragment
1849 * Takes an additional reference on the paged fragment @frag.
1851 static inline void __skb_frag_ref(skb_frag_t *frag)
1853 get_page(skb_frag_page(frag));
1857 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
1859 * @f: the fragment offset.
1861 * Takes an additional reference on the @f'th paged fragment of @skb.
1863 static inline void skb_frag_ref(struct sk_buff *skb, int f)
1865 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
1869 * __skb_frag_unref - release a reference on a paged fragment.
1870 * @frag: the paged fragment
1872 * Releases a reference on the paged fragment @frag.
1874 static inline void __skb_frag_unref(skb_frag_t *frag)
1876 put_page(skb_frag_page(frag));
1880 * skb_frag_unref - release a reference on a paged fragment of an skb.
1882 * @f: the fragment offset
1884 * Releases a reference on the @f'th paged fragment of @skb.
1886 static inline void skb_frag_unref(struct sk_buff *skb, int f)
1888 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
1892 * skb_frag_address - gets the address of the data contained in a paged fragment
1893 * @frag: the paged fragment buffer
1895 * Returns the address of the data within @frag. The page must already
1898 static inline void *skb_frag_address(const skb_frag_t *frag)
1900 return page_address(skb_frag_page(frag)) + frag->page_offset;
1904 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
1905 * @frag: the paged fragment buffer
1907 * Returns the address of the data within @frag. Checks that the page
1908 * is mapped and returns %NULL otherwise.
1910 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
1912 void *ptr = page_address(skb_frag_page(frag));
1916 return ptr + frag->page_offset;
1920 * __skb_frag_set_page - sets the page contained in a paged fragment
1921 * @frag: the paged fragment
1922 * @page: the page to set
1924 * Sets the fragment @frag to contain @page.
1926 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
1928 frag->page.p = page;
1932 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
1934 * @f: the fragment offset
1935 * @page: the page to set
1937 * Sets the @f'th fragment of @skb to contain @page.
1939 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
1942 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
1946 * skb_frag_dma_map - maps a paged fragment via the DMA API
1947 * @dev: the device to map the fragment to
1948 * @frag: the paged fragment to map
1949 * @offset: the offset within the fragment (starting at the
1950 * fragment's own offset)
1951 * @size: the number of bytes to map
1952 * @dir: the direction of the mapping (%PCI_DMA_*)
1954 * Maps the page associated with @frag to @device.
1956 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
1957 const skb_frag_t *frag,
1958 size_t offset, size_t size,
1959 enum dma_data_direction dir)
1961 return dma_map_page(dev, skb_frag_page(frag),
1962 frag->page_offset + offset, size, dir);
1965 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
1968 return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
1972 * skb_clone_writable - is the header of a clone writable
1973 * @skb: buffer to check
1974 * @len: length up to which to write
1976 * Returns true if modifying the header part of the cloned buffer
1977 * does not requires the data to be copied.
1979 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
1981 return !skb_header_cloned(skb) &&
1982 skb_headroom(skb) + len <= skb->hdr_len;
1985 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1990 if (headroom > skb_headroom(skb))
1991 delta = headroom - skb_headroom(skb);
1993 if (delta || cloned)
1994 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
2000 * skb_cow - copy header of skb when it is required
2001 * @skb: buffer to cow
2002 * @headroom: needed headroom
2004 * If the skb passed lacks sufficient headroom or its data part
2005 * is shared, data is reallocated. If reallocation fails, an error
2006 * is returned and original skb is not changed.
2008 * The result is skb with writable area skb->head...skb->tail
2009 * and at least @headroom of space at head.
2011 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
2013 return __skb_cow(skb, headroom, skb_cloned(skb));
2017 * skb_cow_head - skb_cow but only making the head writable
2018 * @skb: buffer to cow
2019 * @headroom: needed headroom
2021 * This function is identical to skb_cow except that we replace the
2022 * skb_cloned check by skb_header_cloned. It should be used when
2023 * you only need to push on some header and do not need to modify
2026 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
2028 return __skb_cow(skb, headroom, skb_header_cloned(skb));
2032 * skb_padto - pad an skbuff up to a minimal size
2033 * @skb: buffer to pad
2034 * @len: minimal length
2036 * Pads up a buffer to ensure the trailing bytes exist and are
2037 * blanked. If the buffer already contains sufficient data it
2038 * is untouched. Otherwise it is extended. Returns zero on
2039 * success. The skb is freed on error.
2042 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
2044 unsigned int size = skb->len;
2045 if (likely(size >= len))
2047 return skb_pad(skb, len - size);
2050 static inline int skb_add_data(struct sk_buff *skb,
2051 char __user *from, int copy)
2053 const int off = skb->len;
2055 if (skb->ip_summed == CHECKSUM_NONE) {
2057 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
2060 skb->csum = csum_block_add(skb->csum, csum, off);
2063 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
2066 __skb_trim(skb, off);
2070 static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
2071 const struct page *page, int off)
2074 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
2076 return page == skb_frag_page(frag) &&
2077 off == frag->page_offset + skb_frag_size(frag);
2082 static inline int __skb_linearize(struct sk_buff *skb)
2084 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
2088 * skb_linearize - convert paged skb to linear one
2089 * @skb: buffer to linarize
2091 * If there is no free memory -ENOMEM is returned, otherwise zero
2092 * is returned and the old skb data released.
2094 static inline int skb_linearize(struct sk_buff *skb)
2096 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
2100 * skb_linearize_cow - make sure skb is linear and writable
2101 * @skb: buffer to process
2103 * If there is no free memory -ENOMEM is returned, otherwise zero
2104 * is returned and the old skb data released.
2106 static inline int skb_linearize_cow(struct sk_buff *skb)
2108 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
2109 __skb_linearize(skb) : 0;
2113 * skb_postpull_rcsum - update checksum for received skb after pull
2114 * @skb: buffer to update
2115 * @start: start of data before pull
2116 * @len: length of data pulled
2118 * After doing a pull on a received packet, you need to call this to
2119 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2120 * CHECKSUM_NONE so that it can be recomputed from scratch.
2123 static inline void skb_postpull_rcsum(struct sk_buff *skb,
2124 const void *start, unsigned int len)
2126 if (skb->ip_summed == CHECKSUM_COMPLETE)
2127 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
2130 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
2133 * pskb_trim_rcsum - trim received skb and update checksum
2134 * @skb: buffer to trim
2137 * This is exactly the same as pskb_trim except that it ensures the
2138 * checksum of received packets are still valid after the operation.
2141 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
2143 if (likely(len >= skb->len))
2145 if (skb->ip_summed == CHECKSUM_COMPLETE)
2146 skb->ip_summed = CHECKSUM_NONE;
2147 return __pskb_trim(skb, len);
2150 #define skb_queue_walk(queue, skb) \
2151 for (skb = (queue)->next; \
2152 skb != (struct sk_buff *)(queue); \
2155 #define skb_queue_walk_safe(queue, skb, tmp) \
2156 for (skb = (queue)->next, tmp = skb->next; \
2157 skb != (struct sk_buff *)(queue); \
2158 skb = tmp, tmp = skb->next)
2160 #define skb_queue_walk_from(queue, skb) \
2161 for (; skb != (struct sk_buff *)(queue); \
2164 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2165 for (tmp = skb->next; \
2166 skb != (struct sk_buff *)(queue); \
2167 skb = tmp, tmp = skb->next)
2169 #define skb_queue_reverse_walk(queue, skb) \
2170 for (skb = (queue)->prev; \
2171 skb != (struct sk_buff *)(queue); \
2174 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2175 for (skb = (queue)->prev, tmp = skb->prev; \
2176 skb != (struct sk_buff *)(queue); \
2177 skb = tmp, tmp = skb->prev)
2179 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2180 for (tmp = skb->prev; \
2181 skb != (struct sk_buff *)(queue); \
2182 skb = tmp, tmp = skb->prev)
2184 static inline bool skb_has_frag_list(const struct sk_buff *skb)
2186 return skb_shinfo(skb)->frag_list != NULL;
2189 static inline void skb_frag_list_init(struct sk_buff *skb)
2191 skb_shinfo(skb)->frag_list = NULL;
2194 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
2196 frag->next = skb_shinfo(skb)->frag_list;
2197 skb_shinfo(skb)->frag_list = frag;
2200 #define skb_walk_frags(skb, iter) \
2201 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2203 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
2204 int *peeked, int *off, int *err);
2205 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
2206 int noblock, int *err);
2207 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
2208 struct poll_table_struct *wait);
2209 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
2210 int offset, struct iovec *to,
2212 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
2215 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
2217 const struct iovec *from,
2220 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from,
2222 const struct iovec *to,
2225 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
2226 extern void skb_free_datagram_locked(struct sock *sk,
2227 struct sk_buff *skb);
2228 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
2229 unsigned int flags);
2230 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
2231 int len, __wsum csum);
2232 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
2234 extern int skb_store_bits(struct sk_buff *skb, int offset,
2235 const void *from, int len);
2236 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
2237 int offset, u8 *to, int len,
2239 extern int skb_splice_bits(struct sk_buff *skb,
2240 unsigned int offset,
2241 struct pipe_inode_info *pipe,
2243 unsigned int flags);
2244 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
2245 extern void skb_split(struct sk_buff *skb,
2246 struct sk_buff *skb1, const u32 len);
2247 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
2250 extern struct sk_buff *skb_segment(struct sk_buff *skb,
2251 netdev_features_t features);
2253 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
2254 int len, void *buffer)
2256 int hlen = skb_headlen(skb);
2258 if (hlen - offset >= len)
2259 return skb->data + offset;
2261 if (skb_copy_bits(skb, offset, buffer, len) < 0)
2267 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
2269 const unsigned int len)
2271 memcpy(to, skb->data, len);
2274 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
2275 const int offset, void *to,
2276 const unsigned int len)
2278 memcpy(to, skb->data + offset, len);
2281 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
2283 const unsigned int len)
2285 memcpy(skb->data, from, len);
2288 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
2291 const unsigned int len)
2293 memcpy(skb->data + offset, from, len);
2296 extern void skb_init(void);
2298 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
2304 * skb_get_timestamp - get timestamp from a skb
2305 * @skb: skb to get stamp from
2306 * @stamp: pointer to struct timeval to store stamp in
2308 * Timestamps are stored in the skb as offsets to a base timestamp.
2309 * This function converts the offset back to a struct timeval and stores
2312 static inline void skb_get_timestamp(const struct sk_buff *skb,
2313 struct timeval *stamp)
2315 *stamp = ktime_to_timeval(skb->tstamp);
2318 static inline void skb_get_timestampns(const struct sk_buff *skb,
2319 struct timespec *stamp)
2321 *stamp = ktime_to_timespec(skb->tstamp);
2324 static inline void __net_timestamp(struct sk_buff *skb)
2326 skb->tstamp = ktime_get_real();
2329 static inline ktime_t net_timedelta(ktime_t t)
2331 return ktime_sub(ktime_get_real(), t);
2334 static inline ktime_t net_invalid_timestamp(void)
2336 return ktime_set(0, 0);
2339 extern void skb_timestamping_init(void);
2341 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2343 extern void skb_clone_tx_timestamp(struct sk_buff *skb);
2344 extern bool skb_defer_rx_timestamp(struct sk_buff *skb);
2346 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2348 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
2352 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
2357 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2360 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2362 * PHY drivers may accept clones of transmitted packets for
2363 * timestamping via their phy_driver.txtstamp method. These drivers
2364 * must call this function to return the skb back to the stack, with
2365 * or without a timestamp.
2367 * @skb: clone of the the original outgoing packet
2368 * @hwtstamps: hardware time stamps, may be NULL if not available
2371 void skb_complete_tx_timestamp(struct sk_buff *skb,
2372 struct skb_shared_hwtstamps *hwtstamps);
2375 * skb_tstamp_tx - queue clone of skb with send time stamps
2376 * @orig_skb: the original outgoing packet
2377 * @hwtstamps: hardware time stamps, may be NULL if not available
2379 * If the skb has a socket associated, then this function clones the
2380 * skb (thus sharing the actual data and optional structures), stores
2381 * the optional hardware time stamping information (if non NULL) or
2382 * generates a software time stamp (otherwise), then queues the clone
2383 * to the error queue of the socket. Errors are silently ignored.
2385 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
2386 struct skb_shared_hwtstamps *hwtstamps);
2388 static inline void sw_tx_timestamp(struct sk_buff *skb)
2390 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP &&
2391 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
2392 skb_tstamp_tx(skb, NULL);
2396 * skb_tx_timestamp() - Driver hook for transmit timestamping
2398 * Ethernet MAC Drivers should call this function in their hard_xmit()
2399 * function immediately before giving the sk_buff to the MAC hardware.
2401 * @skb: A socket buffer.
2403 static inline void skb_tx_timestamp(struct sk_buff *skb)
2405 skb_clone_tx_timestamp(skb);
2406 sw_tx_timestamp(skb);
2410 * skb_complete_wifi_ack - deliver skb with wifi status
2412 * @skb: the original outgoing packet
2413 * @acked: ack status
2416 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
2418 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
2419 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
2421 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
2423 return skb->ip_summed & CHECKSUM_UNNECESSARY;
2427 * skb_checksum_complete - Calculate checksum of an entire packet
2428 * @skb: packet to process
2430 * This function calculates the checksum over the entire packet plus
2431 * the value of skb->csum. The latter can be used to supply the
2432 * checksum of a pseudo header as used by TCP/UDP. It returns the
2435 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2436 * this function can be used to verify that checksum on received
2437 * packets. In that case the function should return zero if the
2438 * checksum is correct. In particular, this function will return zero
2439 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2440 * hardware has already verified the correctness of the checksum.
2442 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
2444 return skb_csum_unnecessary(skb) ?
2445 0 : __skb_checksum_complete(skb);
2448 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2449 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
2450 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
2452 if (nfct && atomic_dec_and_test(&nfct->use))
2453 nf_conntrack_destroy(nfct);
2455 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
2458 atomic_inc(&nfct->use);
2461 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2462 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
2465 atomic_inc(&skb->users);
2467 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
2473 #ifdef CONFIG_BRIDGE_NETFILTER
2474 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
2476 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
2479 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
2482 atomic_inc(&nf_bridge->use);
2484 #endif /* CONFIG_BRIDGE_NETFILTER */
2485 static inline void nf_reset(struct sk_buff *skb)
2487 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2488 nf_conntrack_put(skb->nfct);
2491 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2492 nf_conntrack_put_reasm(skb->nfct_reasm);
2493 skb->nfct_reasm = NULL;
2495 #ifdef CONFIG_BRIDGE_NETFILTER
2496 nf_bridge_put(skb->nf_bridge);
2497 skb->nf_bridge = NULL;
2501 /* Note: This doesn't put any conntrack and bridge info in dst. */
2502 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2504 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2505 dst->nfct = src->nfct;
2506 nf_conntrack_get(src->nfct);
2507 dst->nfctinfo = src->nfctinfo;
2509 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2510 dst->nfct_reasm = src->nfct_reasm;
2511 nf_conntrack_get_reasm(src->nfct_reasm);
2513 #ifdef CONFIG_BRIDGE_NETFILTER
2514 dst->nf_bridge = src->nf_bridge;
2515 nf_bridge_get(src->nf_bridge);
2519 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2521 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2522 nf_conntrack_put(dst->nfct);
2524 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2525 nf_conntrack_put_reasm(dst->nfct_reasm);
2527 #ifdef CONFIG_BRIDGE_NETFILTER
2528 nf_bridge_put(dst->nf_bridge);
2530 __nf_copy(dst, src);
2533 #ifdef CONFIG_NETWORK_SECMARK
2534 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2536 to->secmark = from->secmark;
2539 static inline void skb_init_secmark(struct sk_buff *skb)
2544 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2547 static inline void skb_init_secmark(struct sk_buff *skb)
2551 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
2553 skb->queue_mapping = queue_mapping;
2556 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
2558 return skb->queue_mapping;
2561 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
2563 to->queue_mapping = from->queue_mapping;
2566 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
2568 skb->queue_mapping = rx_queue + 1;
2571 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2573 return skb->queue_mapping - 1;
2576 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2578 return skb->queue_mapping != 0;
2581 extern u16 __skb_tx_hash(const struct net_device *dev,
2582 const struct sk_buff *skb,
2583 unsigned int num_tx_queues);
2586 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2591 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2597 static inline bool skb_is_gso(const struct sk_buff *skb)
2599 return skb_shinfo(skb)->gso_size;
2602 static inline bool skb_is_gso_v6(const struct sk_buff *skb)
2604 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2607 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2609 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2611 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2612 * wanted then gso_type will be set. */
2613 const struct skb_shared_info *shinfo = skb_shinfo(skb);
2615 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
2616 unlikely(shinfo->gso_type == 0)) {
2617 __skb_warn_lro_forwarding(skb);
2623 static inline void skb_forward_csum(struct sk_buff *skb)
2625 /* Unfortunately we don't support this one. Any brave souls? */
2626 if (skb->ip_summed == CHECKSUM_COMPLETE)
2627 skb->ip_summed = CHECKSUM_NONE;
2631 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
2632 * @skb: skb to check
2634 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
2635 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
2636 * use this helper, to document places where we make this assertion.
2638 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
2641 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
2645 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2648 * skb_head_is_locked - Determine if the skb->head is locked down
2649 * @skb: skb to check
2651 * The head on skbs build around a head frag can be removed if they are
2652 * not cloned. This function returns true if the skb head is locked down
2653 * due to either being allocated via kmalloc, or by being a clone with
2654 * multiple references to the head.
2656 static inline bool skb_head_is_locked(const struct sk_buff *skb)
2658 return !skb->head_frag || skb_cloned(skb);
2660 #endif /* __KERNEL__ */
2661 #endif /* _LINUX_SKBUFF_H */