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,
234 /* This indicates at least one fragment might be overwritten
235 * (as in vmsplice(), sendfile() ...)
236 * If we need to compute a TX checksum, we'll need to copy
237 * all frags to avoid possible bad checksum
239 SKBTX_SHARED_FRAG = 1 << 5,
243 * The callback notifies userspace to release buffers when skb DMA is done in
244 * lower device, the skb last reference should be 0 when calling this.
245 * The zerocopy_success argument is true if zero copy transmit occurred,
246 * false on data copy or out of memory error caused by data copy attempt.
247 * The ctx field is used to track device context.
248 * The desc field is used to track userspace buffer index.
251 void (*callback)(struct ubuf_info *, bool zerocopy_success);
256 /* This data is invariant across clones and lives at
257 * the end of the header data, ie. at skb->end.
259 struct skb_shared_info {
260 unsigned char nr_frags;
262 unsigned short gso_size;
263 /* Warning: this field is not always filled in (UFO)! */
264 unsigned short gso_segs;
265 unsigned short gso_type;
266 struct sk_buff *frag_list;
267 struct skb_shared_hwtstamps hwtstamps;
271 * Warning : all fields before dataref are cleared in __alloc_skb()
275 /* Intermediate layers must ensure that destructor_arg
276 * remains valid until skb destructor */
277 void * destructor_arg;
279 /* must be last field, see pskb_expand_head() */
280 skb_frag_t frags[MAX_SKB_FRAGS];
283 /* We divide dataref into two halves. The higher 16 bits hold references
284 * to the payload part of skb->data. The lower 16 bits hold references to
285 * the entire skb->data. A clone of a headerless skb holds the length of
286 * the header in skb->hdr_len.
288 * All users must obey the rule that the skb->data reference count must be
289 * greater than or equal to the payload reference count.
291 * Holding a reference to the payload part means that the user does not
292 * care about modifications to the header part of skb->data.
294 #define SKB_DATAREF_SHIFT 16
295 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
299 SKB_FCLONE_UNAVAILABLE,
305 SKB_GSO_TCPV4 = 1 << 0,
306 SKB_GSO_UDP = 1 << 1,
308 /* This indicates the skb is from an untrusted source. */
309 SKB_GSO_DODGY = 1 << 2,
311 /* This indicates the tcp segment has CWR set. */
312 SKB_GSO_TCP_ECN = 1 << 3,
314 SKB_GSO_TCPV6 = 1 << 4,
316 SKB_GSO_FCOE = 1 << 5,
318 SKB_GSO_GRE = 1 << 6,
320 SKB_GSO_UDP_TUNNEL = 1 << 7,
323 #if BITS_PER_LONG > 32
324 #define NET_SKBUFF_DATA_USES_OFFSET 1
327 #ifdef NET_SKBUFF_DATA_USES_OFFSET
328 typedef unsigned int sk_buff_data_t;
330 typedef unsigned char *sk_buff_data_t;
333 #if defined(CONFIG_NF_DEFRAG_IPV4) || defined(CONFIG_NF_DEFRAG_IPV4_MODULE) || \
334 defined(CONFIG_NF_DEFRAG_IPV6) || defined(CONFIG_NF_DEFRAG_IPV6_MODULE)
335 #define NET_SKBUFF_NF_DEFRAG_NEEDED 1
339 * struct sk_buff - socket buffer
340 * @next: Next buffer in list
341 * @prev: Previous buffer in list
342 * @tstamp: Time we arrived
343 * @sk: Socket we are owned by
344 * @dev: Device we arrived on/are leaving by
345 * @cb: Control buffer. Free for use by every layer. Put private vars here
346 * @_skb_refdst: destination entry (with norefcount bit)
347 * @sp: the security path, used for xfrm
348 * @len: Length of actual data
349 * @data_len: Data length
350 * @mac_len: Length of link layer header
351 * @hdr_len: writable header length of cloned skb
352 * @csum: Checksum (must include start/offset pair)
353 * @csum_start: Offset from skb->head where checksumming should start
354 * @csum_offset: Offset from csum_start where checksum should be stored
355 * @priority: Packet queueing priority
356 * @local_df: allow local fragmentation
357 * @cloned: Head may be cloned (check refcnt to be sure)
358 * @ip_summed: Driver fed us an IP checksum
359 * @nohdr: Payload reference only, must not modify header
360 * @nfctinfo: Relationship of this skb to the connection
361 * @pkt_type: Packet class
362 * @fclone: skbuff clone status
363 * @ipvs_property: skbuff is owned by ipvs
364 * @peeked: this packet has been seen already, so stats have been
365 * done for it, don't do them again
366 * @nf_trace: netfilter packet trace flag
367 * @protocol: Packet protocol from driver
368 * @destructor: Destruct function
369 * @nfct: Associated connection, if any
370 * @nfct_reasm: netfilter conntrack re-assembly pointer
371 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
372 * @skb_iif: ifindex of device we arrived on
373 * @tc_index: Traffic control index
374 * @tc_verd: traffic control verdict
375 * @rxhash: the packet hash computed on receive
376 * @queue_mapping: Queue mapping for multiqueue devices
377 * @ndisc_nodetype: router type (from link layer)
378 * @ooo_okay: allow the mapping of a socket to a queue to be changed
379 * @l4_rxhash: indicate rxhash is a canonical 4-tuple hash over transport
381 * @wifi_acked_valid: wifi_acked was set
382 * @wifi_acked: whether frame was acked on wifi or not
383 * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS
384 * @dma_cookie: a cookie to one of several possible DMA operations
385 * done by skb DMA functions
386 * @secmark: security marking
387 * @mark: Generic packet mark
388 * @dropcount: total number of sk_receive_queue overflows
389 * @vlan_tci: vlan tag control information
390 * @inner_transport_header: Inner transport layer header (encapsulation)
391 * @inner_network_header: Network layer header (encapsulation)
392 * @inner_mac_header: Link layer header (encapsulation)
393 * @transport_header: Transport layer header
394 * @network_header: Network layer header
395 * @mac_header: Link layer header
396 * @tail: Tail pointer
398 * @head: Head of buffer
399 * @data: Data head pointer
400 * @truesize: Buffer size
401 * @users: User count - see {datagram,tcp}.c
405 /* These two members must be first. */
406 struct sk_buff *next;
407 struct sk_buff *prev;
412 struct net_device *dev;
415 * This is the control buffer. It is free to use for every
416 * layer. Please put your private variables there. If you
417 * want to keep them across layers you have to do a skb_clone()
418 * first. This is owned by whoever has the skb queued ATM.
420 char cb[48] __aligned(8);
422 unsigned long _skb_refdst;
438 kmemcheck_bitfield_begin(flags1);
449 kmemcheck_bitfield_end(flags1);
452 void (*destructor)(struct sk_buff *skb);
453 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
454 struct nf_conntrack *nfct;
456 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
457 struct sk_buff *nfct_reasm;
459 #ifdef CONFIG_BRIDGE_NETFILTER
460 struct nf_bridge_info *nf_bridge;
469 #ifdef CONFIG_NET_SCHED
470 __u16 tc_index; /* traffic control index */
471 #ifdef CONFIG_NET_CLS_ACT
472 __u16 tc_verd; /* traffic control verdict */
477 kmemcheck_bitfield_begin(flags2);
478 #ifdef CONFIG_IPV6_NDISC_NODETYPE
479 __u8 ndisc_nodetype:2;
484 __u8 wifi_acked_valid:1;
488 /* Encapsulation protocol and NIC drivers should use
489 * this flag to indicate to each other if the skb contains
490 * encapsulated packet or not and maybe use the inner packet
493 __u8 encapsulation:1;
494 /* 7/9 bit hole (depending on ndisc_nodetype presence) */
495 kmemcheck_bitfield_end(flags2);
497 #ifdef CONFIG_NET_DMA
498 dma_cookie_t dma_cookie;
500 #ifdef CONFIG_NETWORK_SECMARK
509 sk_buff_data_t inner_transport_header;
510 sk_buff_data_t inner_network_header;
511 sk_buff_data_t inner_mac_header;
512 sk_buff_data_t transport_header;
513 sk_buff_data_t network_header;
514 sk_buff_data_t mac_header;
515 /* These elements must be at the end, see alloc_skb() for details. */
520 unsigned int truesize;
526 * Handling routines are only of interest to the kernel
528 #include <linux/slab.h>
531 #define SKB_ALLOC_FCLONE 0x01
532 #define SKB_ALLOC_RX 0x02
534 /* Returns true if the skb was allocated from PFMEMALLOC reserves */
535 static inline bool skb_pfmemalloc(const struct sk_buff *skb)
537 return unlikely(skb->pfmemalloc);
541 * skb might have a dst pointer attached, refcounted or not.
542 * _skb_refdst low order bit is set if refcount was _not_ taken
544 #define SKB_DST_NOREF 1UL
545 #define SKB_DST_PTRMASK ~(SKB_DST_NOREF)
548 * skb_dst - returns skb dst_entry
551 * Returns skb dst_entry, regardless of reference taken or not.
553 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
555 /* If refdst was not refcounted, check we still are in a
556 * rcu_read_lock section
558 WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) &&
559 !rcu_read_lock_held() &&
560 !rcu_read_lock_bh_held());
561 return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK);
565 * skb_dst_set - sets skb dst
569 * Sets skb dst, assuming a reference was taken on dst and should
570 * be released by skb_dst_drop()
572 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
574 skb->_skb_refdst = (unsigned long)dst;
577 extern void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst);
580 * skb_dst_is_noref - Test if skb dst isn't refcounted
583 static inline bool skb_dst_is_noref(const struct sk_buff *skb)
585 return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb);
588 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
590 return (struct rtable *)skb_dst(skb);
593 extern void kfree_skb(struct sk_buff *skb);
594 extern void skb_tx_error(struct sk_buff *skb);
595 extern void consume_skb(struct sk_buff *skb);
596 extern void __kfree_skb(struct sk_buff *skb);
597 extern struct kmem_cache *skbuff_head_cache;
599 extern void kfree_skb_partial(struct sk_buff *skb, bool head_stolen);
600 extern bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from,
601 bool *fragstolen, int *delta_truesize);
603 extern struct sk_buff *__alloc_skb(unsigned int size,
604 gfp_t priority, int flags, int node);
605 extern struct sk_buff *build_skb(void *data, unsigned int frag_size);
606 static inline struct sk_buff *alloc_skb(unsigned int size,
609 return __alloc_skb(size, priority, 0, NUMA_NO_NODE);
612 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
615 return __alloc_skb(size, priority, SKB_ALLOC_FCLONE, NUMA_NO_NODE);
618 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
619 extern int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask);
620 extern struct sk_buff *skb_clone(struct sk_buff *skb,
622 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
624 extern struct sk_buff *__pskb_copy(struct sk_buff *skb,
625 int headroom, gfp_t gfp_mask);
627 extern int pskb_expand_head(struct sk_buff *skb,
628 int nhead, int ntail,
630 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
631 unsigned int headroom);
632 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
633 int newheadroom, int newtailroom,
635 extern int skb_to_sgvec(struct sk_buff *skb,
636 struct scatterlist *sg, int offset,
638 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
639 struct sk_buff **trailer);
640 extern int skb_pad(struct sk_buff *skb, int pad);
641 #define dev_kfree_skb(a) consume_skb(a)
643 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
644 int getfrag(void *from, char *to, int offset,
645 int len,int odd, struct sk_buff *skb),
646 void *from, int length);
648 struct skb_seq_state {
652 __u32 stepped_offset;
653 struct sk_buff *root_skb;
654 struct sk_buff *cur_skb;
658 extern void skb_prepare_seq_read(struct sk_buff *skb,
659 unsigned int from, unsigned int to,
660 struct skb_seq_state *st);
661 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
662 struct skb_seq_state *st);
663 extern void skb_abort_seq_read(struct skb_seq_state *st);
665 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
666 unsigned int to, struct ts_config *config,
667 struct ts_state *state);
669 extern void __skb_get_rxhash(struct sk_buff *skb);
670 static inline __u32 skb_get_rxhash(struct sk_buff *skb)
673 __skb_get_rxhash(skb);
678 #ifdef NET_SKBUFF_DATA_USES_OFFSET
679 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
681 return skb->head + skb->end;
684 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
689 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
694 static inline unsigned int skb_end_offset(const struct sk_buff *skb)
696 return skb->end - skb->head;
701 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
703 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
705 return &skb_shinfo(skb)->hwtstamps;
709 * skb_queue_empty - check if a queue is empty
712 * Returns true if the queue is empty, false otherwise.
714 static inline int skb_queue_empty(const struct sk_buff_head *list)
716 return list->next == (struct sk_buff *)list;
720 * skb_queue_is_last - check if skb is the last entry in the queue
724 * Returns true if @skb is the last buffer on the list.
726 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
727 const struct sk_buff *skb)
729 return skb->next == (struct sk_buff *)list;
733 * skb_queue_is_first - check if skb is the first entry in the queue
737 * Returns true if @skb is the first buffer on the list.
739 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
740 const struct sk_buff *skb)
742 return skb->prev == (struct sk_buff *)list;
746 * skb_queue_next - return the next packet in the queue
748 * @skb: current buffer
750 * Return the next packet in @list after @skb. It is only valid to
751 * call this if skb_queue_is_last() evaluates to false.
753 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
754 const struct sk_buff *skb)
756 /* This BUG_ON may seem severe, but if we just return then we
757 * are going to dereference garbage.
759 BUG_ON(skb_queue_is_last(list, skb));
764 * skb_queue_prev - return the prev packet in the queue
766 * @skb: current buffer
768 * Return the prev packet in @list before @skb. It is only valid to
769 * call this if skb_queue_is_first() evaluates to false.
771 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
772 const struct sk_buff *skb)
774 /* This BUG_ON may seem severe, but if we just return then we
775 * are going to dereference garbage.
777 BUG_ON(skb_queue_is_first(list, skb));
782 * skb_get - reference buffer
783 * @skb: buffer to reference
785 * Makes another reference to a socket buffer and returns a pointer
788 static inline struct sk_buff *skb_get(struct sk_buff *skb)
790 atomic_inc(&skb->users);
795 * If users == 1, we are the only owner and are can avoid redundant
800 * skb_cloned - is the buffer a clone
801 * @skb: buffer to check
803 * Returns true if the buffer was generated with skb_clone() and is
804 * one of multiple shared copies of the buffer. Cloned buffers are
805 * shared data so must not be written to under normal circumstances.
807 static inline int skb_cloned(const struct sk_buff *skb)
809 return skb->cloned &&
810 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
813 static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
815 might_sleep_if(pri & __GFP_WAIT);
818 return pskb_expand_head(skb, 0, 0, pri);
824 * skb_header_cloned - is the header a clone
825 * @skb: buffer to check
827 * Returns true if modifying the header part of the buffer requires
828 * the data to be copied.
830 static inline int skb_header_cloned(const struct sk_buff *skb)
837 dataref = atomic_read(&skb_shinfo(skb)->dataref);
838 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
843 * skb_header_release - release reference to header
844 * @skb: buffer to operate on
846 * Drop a reference to the header part of the buffer. This is done
847 * by acquiring a payload reference. You must not read from the header
848 * part of skb->data after this.
850 static inline void skb_header_release(struct sk_buff *skb)
854 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
858 * skb_shared - is the buffer shared
859 * @skb: buffer to check
861 * Returns true if more than one person has a reference to this
864 static inline int skb_shared(const struct sk_buff *skb)
866 return atomic_read(&skb->users) != 1;
870 * skb_share_check - check if buffer is shared and if so clone it
871 * @skb: buffer to check
872 * @pri: priority for memory allocation
874 * If the buffer is shared the buffer is cloned and the old copy
875 * drops a reference. A new clone with a single reference is returned.
876 * If the buffer is not shared the original buffer is returned. When
877 * being called from interrupt status or with spinlocks held pri must
880 * NULL is returned on a memory allocation failure.
882 static inline struct sk_buff *skb_share_check(struct sk_buff *skb, gfp_t pri)
884 might_sleep_if(pri & __GFP_WAIT);
885 if (skb_shared(skb)) {
886 struct sk_buff *nskb = skb_clone(skb, pri);
898 * Copy shared buffers into a new sk_buff. We effectively do COW on
899 * packets to handle cases where we have a local reader and forward
900 * and a couple of other messy ones. The normal one is tcpdumping
901 * a packet thats being forwarded.
905 * skb_unshare - make a copy of a shared buffer
906 * @skb: buffer to check
907 * @pri: priority for memory allocation
909 * If the socket buffer is a clone then this function creates a new
910 * copy of the data, drops a reference count on the old copy and returns
911 * the new copy with the reference count at 1. If the buffer is not a clone
912 * the original buffer is returned. When called with a spinlock held or
913 * from interrupt state @pri must be %GFP_ATOMIC
915 * %NULL is returned on a memory allocation failure.
917 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
920 might_sleep_if(pri & __GFP_WAIT);
921 if (skb_cloned(skb)) {
922 struct sk_buff *nskb = skb_copy(skb, pri);
923 kfree_skb(skb); /* Free our shared copy */
930 * skb_peek - peek at the head of an &sk_buff_head
931 * @list_: list to peek at
933 * Peek an &sk_buff. Unlike most other operations you _MUST_
934 * be careful with this one. A peek leaves the buffer on the
935 * list and someone else may run off with it. You must hold
936 * the appropriate locks or have a private queue to do this.
938 * Returns %NULL for an empty list or a pointer to the head element.
939 * The reference count is not incremented and the reference is therefore
940 * volatile. Use with caution.
942 static inline struct sk_buff *skb_peek(const struct sk_buff_head *list_)
944 struct sk_buff *skb = list_->next;
946 if (skb == (struct sk_buff *)list_)
952 * skb_peek_next - peek skb following the given one from a queue
953 * @skb: skb to start from
954 * @list_: list to peek at
956 * Returns %NULL when the end of the list is met or a pointer to the
957 * next element. The reference count is not incremented and the
958 * reference is therefore volatile. Use with caution.
960 static inline struct sk_buff *skb_peek_next(struct sk_buff *skb,
961 const struct sk_buff_head *list_)
963 struct sk_buff *next = skb->next;
965 if (next == (struct sk_buff *)list_)
971 * skb_peek_tail - peek at the tail of an &sk_buff_head
972 * @list_: list to peek at
974 * Peek an &sk_buff. Unlike most other operations you _MUST_
975 * be careful with this one. A peek leaves the buffer on the
976 * list and someone else may run off with it. You must hold
977 * the appropriate locks or have a private queue to do this.
979 * Returns %NULL for an empty list or a pointer to the tail element.
980 * The reference count is not incremented and the reference is therefore
981 * volatile. Use with caution.
983 static inline struct sk_buff *skb_peek_tail(const struct sk_buff_head *list_)
985 struct sk_buff *skb = list_->prev;
987 if (skb == (struct sk_buff *)list_)
994 * skb_queue_len - get queue length
995 * @list_: list to measure
997 * Return the length of an &sk_buff queue.
999 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
1005 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
1006 * @list: queue to initialize
1008 * This initializes only the list and queue length aspects of
1009 * an sk_buff_head object. This allows to initialize the list
1010 * aspects of an sk_buff_head without reinitializing things like
1011 * the spinlock. It can also be used for on-stack sk_buff_head
1012 * objects where the spinlock is known to not be used.
1014 static inline void __skb_queue_head_init(struct sk_buff_head *list)
1016 list->prev = list->next = (struct sk_buff *)list;
1021 * This function creates a split out lock class for each invocation;
1022 * this is needed for now since a whole lot of users of the skb-queue
1023 * infrastructure in drivers have different locking usage (in hardirq)
1024 * than the networking core (in softirq only). In the long run either the
1025 * network layer or drivers should need annotation to consolidate the
1026 * main types of usage into 3 classes.
1028 static inline void skb_queue_head_init(struct sk_buff_head *list)
1030 spin_lock_init(&list->lock);
1031 __skb_queue_head_init(list);
1034 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
1035 struct lock_class_key *class)
1037 skb_queue_head_init(list);
1038 lockdep_set_class(&list->lock, class);
1042 * Insert an sk_buff on a list.
1044 * The "__skb_xxxx()" functions are the non-atomic ones that
1045 * can only be called with interrupts disabled.
1047 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
1048 static inline void __skb_insert(struct sk_buff *newsk,
1049 struct sk_buff *prev, struct sk_buff *next,
1050 struct sk_buff_head *list)
1054 next->prev = prev->next = newsk;
1058 static inline void __skb_queue_splice(const struct sk_buff_head *list,
1059 struct sk_buff *prev,
1060 struct sk_buff *next)
1062 struct sk_buff *first = list->next;
1063 struct sk_buff *last = list->prev;
1073 * skb_queue_splice - join two skb lists, this is designed for stacks
1074 * @list: the new list to add
1075 * @head: the place to add it in the first list
1077 static inline void skb_queue_splice(const struct sk_buff_head *list,
1078 struct sk_buff_head *head)
1080 if (!skb_queue_empty(list)) {
1081 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1082 head->qlen += list->qlen;
1087 * skb_queue_splice_init - join two skb lists and reinitialise the emptied list
1088 * @list: the new list to add
1089 * @head: the place to add it in the first list
1091 * The list at @list is reinitialised
1093 static inline void skb_queue_splice_init(struct sk_buff_head *list,
1094 struct sk_buff_head *head)
1096 if (!skb_queue_empty(list)) {
1097 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
1098 head->qlen += list->qlen;
1099 __skb_queue_head_init(list);
1104 * skb_queue_splice_tail - join two skb lists, each list being a queue
1105 * @list: the new list to add
1106 * @head: the place to add it in the first list
1108 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
1109 struct sk_buff_head *head)
1111 if (!skb_queue_empty(list)) {
1112 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1113 head->qlen += list->qlen;
1118 * skb_queue_splice_tail_init - join two skb lists and reinitialise the emptied list
1119 * @list: the new list to add
1120 * @head: the place to add it in the first list
1122 * Each of the lists is a queue.
1123 * The list at @list is reinitialised
1125 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
1126 struct sk_buff_head *head)
1128 if (!skb_queue_empty(list)) {
1129 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
1130 head->qlen += list->qlen;
1131 __skb_queue_head_init(list);
1136 * __skb_queue_after - queue a buffer at the list head
1137 * @list: list to use
1138 * @prev: place after this buffer
1139 * @newsk: buffer to queue
1141 * Queue a buffer int the middle of a list. This function takes no locks
1142 * and you must therefore hold required locks before calling it.
1144 * A buffer cannot be placed on two lists at the same time.
1146 static inline void __skb_queue_after(struct sk_buff_head *list,
1147 struct sk_buff *prev,
1148 struct sk_buff *newsk)
1150 __skb_insert(newsk, prev, prev->next, list);
1153 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
1154 struct sk_buff_head *list);
1156 static inline void __skb_queue_before(struct sk_buff_head *list,
1157 struct sk_buff *next,
1158 struct sk_buff *newsk)
1160 __skb_insert(newsk, next->prev, next, list);
1164 * __skb_queue_head - queue a buffer at the list head
1165 * @list: list to use
1166 * @newsk: buffer to queue
1168 * Queue a buffer at the start of a list. This function takes no locks
1169 * and you must therefore hold required locks before calling it.
1171 * A buffer cannot be placed on two lists at the same time.
1173 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
1174 static inline void __skb_queue_head(struct sk_buff_head *list,
1175 struct sk_buff *newsk)
1177 __skb_queue_after(list, (struct sk_buff *)list, newsk);
1181 * __skb_queue_tail - queue a buffer at the list tail
1182 * @list: list to use
1183 * @newsk: buffer to queue
1185 * Queue a buffer at the end of a list. This function takes no locks
1186 * and you must therefore hold required locks before calling it.
1188 * A buffer cannot be placed on two lists at the same time.
1190 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
1191 static inline void __skb_queue_tail(struct sk_buff_head *list,
1192 struct sk_buff *newsk)
1194 __skb_queue_before(list, (struct sk_buff *)list, newsk);
1198 * remove sk_buff from list. _Must_ be called atomically, and with
1201 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
1202 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
1204 struct sk_buff *next, *prev;
1209 skb->next = skb->prev = NULL;
1215 * __skb_dequeue - remove from the head of the queue
1216 * @list: list to dequeue from
1218 * Remove the head of the list. This function does not take any locks
1219 * so must be used with appropriate locks held only. The head item is
1220 * returned or %NULL if the list is empty.
1222 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1223 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1225 struct sk_buff *skb = skb_peek(list);
1227 __skb_unlink(skb, list);
1232 * __skb_dequeue_tail - remove from the tail of the queue
1233 * @list: list to dequeue from
1235 * Remove the tail of the list. This function does not take any locks
1236 * so must be used with appropriate locks held only. The tail item is
1237 * returned or %NULL if the list is empty.
1239 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1240 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1242 struct sk_buff *skb = skb_peek_tail(list);
1244 __skb_unlink(skb, list);
1249 static inline bool skb_is_nonlinear(const struct sk_buff *skb)
1251 return skb->data_len;
1254 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1256 return skb->len - skb->data_len;
1259 static inline int skb_pagelen(const struct sk_buff *skb)
1263 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1264 len += skb_frag_size(&skb_shinfo(skb)->frags[i]);
1265 return len + skb_headlen(skb);
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 * Initialises the @i'th fragment of @skb to point to &size bytes at
1277 * offset @off within @page.
1279 * Does not take any additional reference on the fragment.
1281 static inline void __skb_fill_page_desc(struct sk_buff *skb, int i,
1282 struct page *page, int off, int size)
1284 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1287 * Propagate page->pfmemalloc to the skb if we can. The problem is
1288 * that not all callers have unique ownership of the page. If
1289 * pfmemalloc is set, we check the mapping as a mapping implies
1290 * page->index is set (index and pfmemalloc share space).
1291 * If it's a valid mapping, we cannot use page->pfmemalloc but we
1292 * do not lose pfmemalloc information as the pages would not be
1293 * allocated using __GFP_MEMALLOC.
1295 if (page->pfmemalloc && !page->mapping)
1296 skb->pfmemalloc = true;
1297 frag->page.p = page;
1298 frag->page_offset = off;
1299 skb_frag_size_set(frag, size);
1303 * skb_fill_page_desc - initialise a paged fragment in an skb
1304 * @skb: buffer containing fragment to be initialised
1305 * @i: paged fragment index to initialise
1306 * @page: the page to use for this fragment
1307 * @off: the offset to the data with @page
1308 * @size: the length of the data
1310 * As per __skb_fill_page_desc() -- initialises the @i'th fragment of
1311 * @skb to point to &size bytes at offset @off within @page. In
1312 * addition updates @skb such that @i is the last fragment.
1314 * Does not take any additional reference on the fragment.
1316 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1317 struct page *page, int off, int size)
1319 __skb_fill_page_desc(skb, i, page, off, size);
1320 skb_shinfo(skb)->nr_frags = i + 1;
1323 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1324 int off, int size, unsigned int truesize);
1326 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1327 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb))
1328 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1330 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1331 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1333 return skb->head + skb->tail;
1336 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1338 skb->tail = skb->data - skb->head;
1341 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1343 skb_reset_tail_pointer(skb);
1344 skb->tail += offset;
1346 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1347 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1352 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1354 skb->tail = skb->data;
1357 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1359 skb->tail = skb->data + offset;
1362 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1365 * Add data to an sk_buff
1367 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1368 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1370 unsigned char *tmp = skb_tail_pointer(skb);
1371 SKB_LINEAR_ASSERT(skb);
1377 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1378 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1385 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1386 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1389 BUG_ON(skb->len < skb->data_len);
1390 return skb->data += len;
1393 static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len)
1395 return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len);
1398 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1400 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1402 if (len > skb_headlen(skb) &&
1403 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1406 return skb->data += len;
1409 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1411 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1414 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1416 if (likely(len <= skb_headlen(skb)))
1418 if (unlikely(len > skb->len))
1420 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1424 * skb_headroom - bytes at buffer head
1425 * @skb: buffer to check
1427 * Return the number of bytes of free space at the head of an &sk_buff.
1429 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1431 return skb->data - skb->head;
1435 * skb_tailroom - bytes at buffer end
1436 * @skb: buffer to check
1438 * Return the number of bytes of free space at the tail of an sk_buff
1440 static inline int skb_tailroom(const struct sk_buff *skb)
1442 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1446 * skb_availroom - bytes at buffer end
1447 * @skb: buffer to check
1449 * Return the number of bytes of free space at the tail of an sk_buff
1450 * allocated by sk_stream_alloc()
1452 static inline int skb_availroom(const struct sk_buff *skb)
1454 return skb_is_nonlinear(skb) ? 0 : skb->avail_size - skb->len;
1458 * skb_reserve - adjust headroom
1459 * @skb: buffer to alter
1460 * @len: bytes to move
1462 * Increase the headroom of an empty &sk_buff by reducing the tail
1463 * room. This is only allowed for an empty buffer.
1465 static inline void skb_reserve(struct sk_buff *skb, int len)
1471 static inline void skb_reset_inner_headers(struct sk_buff *skb)
1473 skb->inner_mac_header = skb->mac_header;
1474 skb->inner_network_header = skb->network_header;
1475 skb->inner_transport_header = skb->transport_header;
1478 static inline void skb_reset_mac_len(struct sk_buff *skb)
1480 skb->mac_len = skb->network_header - skb->mac_header;
1483 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1484 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1487 return skb->head + skb->inner_transport_header;
1490 static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
1492 skb->inner_transport_header = skb->data - skb->head;
1495 static inline void skb_set_inner_transport_header(struct sk_buff *skb,
1498 skb_reset_inner_transport_header(skb);
1499 skb->inner_transport_header += offset;
1502 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
1504 return skb->head + skb->inner_network_header;
1507 static inline void skb_reset_inner_network_header(struct sk_buff *skb)
1509 skb->inner_network_header = skb->data - skb->head;
1512 static inline void skb_set_inner_network_header(struct sk_buff *skb,
1515 skb_reset_inner_network_header(skb);
1516 skb->inner_network_header += offset;
1519 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
1521 return skb->head + skb->inner_mac_header;
1524 static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
1526 skb->inner_mac_header = skb->data - skb->head;
1529 static inline void skb_set_inner_mac_header(struct sk_buff *skb,
1532 skb_reset_inner_mac_header(skb);
1533 skb->inner_mac_header += offset;
1535 static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
1537 return skb->transport_header != ~0U;
1540 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1542 return skb->head + skb->transport_header;
1545 static inline void skb_reset_transport_header(struct sk_buff *skb)
1547 skb->transport_header = skb->data - skb->head;
1550 static inline void skb_set_transport_header(struct sk_buff *skb,
1553 skb_reset_transport_header(skb);
1554 skb->transport_header += offset;
1557 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1559 return skb->head + skb->network_header;
1562 static inline void skb_reset_network_header(struct sk_buff *skb)
1564 skb->network_header = skb->data - skb->head;
1567 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1569 skb_reset_network_header(skb);
1570 skb->network_header += offset;
1573 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1575 return skb->head + skb->mac_header;
1578 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1580 return skb->mac_header != ~0U;
1583 static inline void skb_reset_mac_header(struct sk_buff *skb)
1585 skb->mac_header = skb->data - skb->head;
1588 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1590 skb_reset_mac_header(skb);
1591 skb->mac_header += offset;
1594 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1595 static inline unsigned char *skb_inner_transport_header(const struct sk_buff
1598 return skb->inner_transport_header;
1601 static inline void skb_reset_inner_transport_header(struct sk_buff *skb)
1603 skb->inner_transport_header = skb->data;
1606 static inline void skb_set_inner_transport_header(struct sk_buff *skb,
1609 skb->inner_transport_header = skb->data + offset;
1612 static inline unsigned char *skb_inner_network_header(const struct sk_buff *skb)
1614 return skb->inner_network_header;
1617 static inline void skb_reset_inner_network_header(struct sk_buff *skb)
1619 skb->inner_network_header = skb->data;
1622 static inline void skb_set_inner_network_header(struct sk_buff *skb,
1625 skb->inner_network_header = skb->data + offset;
1628 static inline unsigned char *skb_inner_mac_header(const struct sk_buff *skb)
1630 return skb->inner_mac_header;
1633 static inline void skb_reset_inner_mac_header(struct sk_buff *skb)
1635 skb->inner_mac_header = skb->data;
1638 static inline void skb_set_inner_mac_header(struct sk_buff *skb,
1641 skb->inner_mac_header = skb->data + offset;
1643 static inline bool skb_transport_header_was_set(const struct sk_buff *skb)
1645 return skb->transport_header != NULL;
1648 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1650 return skb->transport_header;
1653 static inline void skb_reset_transport_header(struct sk_buff *skb)
1655 skb->transport_header = skb->data;
1658 static inline void skb_set_transport_header(struct sk_buff *skb,
1661 skb->transport_header = skb->data + offset;
1664 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1666 return skb->network_header;
1669 static inline void skb_reset_network_header(struct sk_buff *skb)
1671 skb->network_header = skb->data;
1674 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1676 skb->network_header = skb->data + offset;
1679 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1681 return skb->mac_header;
1684 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1686 return skb->mac_header != NULL;
1689 static inline void skb_reset_mac_header(struct sk_buff *skb)
1691 skb->mac_header = skb->data;
1694 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1696 skb->mac_header = skb->data + offset;
1698 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1700 static inline void skb_mac_header_rebuild(struct sk_buff *skb)
1702 if (skb_mac_header_was_set(skb)) {
1703 const unsigned char *old_mac = skb_mac_header(skb);
1705 skb_set_mac_header(skb, -skb->mac_len);
1706 memmove(skb_mac_header(skb), old_mac, skb->mac_len);
1710 static inline int skb_checksum_start_offset(const struct sk_buff *skb)
1712 return skb->csum_start - skb_headroom(skb);
1715 static inline int skb_transport_offset(const struct sk_buff *skb)
1717 return skb_transport_header(skb) - skb->data;
1720 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1722 return skb->transport_header - skb->network_header;
1725 static inline u32 skb_inner_network_header_len(const struct sk_buff *skb)
1727 return skb->inner_transport_header - skb->inner_network_header;
1730 static inline int skb_network_offset(const struct sk_buff *skb)
1732 return skb_network_header(skb) - skb->data;
1735 static inline int skb_inner_network_offset(const struct sk_buff *skb)
1737 return skb_inner_network_header(skb) - skb->data;
1740 static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len)
1742 return pskb_may_pull(skb, skb_network_offset(skb) + len);
1746 * CPUs often take a performance hit when accessing unaligned memory
1747 * locations. The actual performance hit varies, it can be small if the
1748 * hardware handles it or large if we have to take an exception and fix it
1751 * Since an ethernet header is 14 bytes network drivers often end up with
1752 * the IP header at an unaligned offset. The IP header can be aligned by
1753 * shifting the start of the packet by 2 bytes. Drivers should do this
1756 * skb_reserve(skb, NET_IP_ALIGN);
1758 * The downside to this alignment of the IP header is that the DMA is now
1759 * unaligned. On some architectures the cost of an unaligned DMA is high
1760 * and this cost outweighs the gains made by aligning the IP header.
1762 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1765 #ifndef NET_IP_ALIGN
1766 #define NET_IP_ALIGN 2
1770 * The networking layer reserves some headroom in skb data (via
1771 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1772 * the header has to grow. In the default case, if the header has to grow
1773 * 32 bytes or less we avoid the reallocation.
1775 * Unfortunately this headroom changes the DMA alignment of the resulting
1776 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1777 * on some architectures. An architecture can override this value,
1778 * perhaps setting it to a cacheline in size (since that will maintain
1779 * cacheline alignment of the DMA). It must be a power of 2.
1781 * Various parts of the networking layer expect at least 32 bytes of
1782 * headroom, you should not reduce this.
1784 * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS)
1785 * to reduce average number of cache lines per packet.
1786 * get_rps_cpus() for example only access one 64 bytes aligned block :
1787 * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8)
1790 #define NET_SKB_PAD max(32, L1_CACHE_BYTES)
1793 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1795 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1797 if (unlikely(skb_is_nonlinear(skb))) {
1802 skb_set_tail_pointer(skb, len);
1805 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1807 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1810 return ___pskb_trim(skb, len);
1811 __skb_trim(skb, len);
1815 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1817 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1821 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1822 * @skb: buffer to alter
1825 * This is identical to pskb_trim except that the caller knows that
1826 * the skb is not cloned so we should never get an error due to out-
1829 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1831 int err = pskb_trim(skb, len);
1836 * skb_orphan - orphan a buffer
1837 * @skb: buffer to orphan
1839 * If a buffer currently has an owner then we call the owner's
1840 * destructor function and make the @skb unowned. The buffer continues
1841 * to exist but is no longer charged to its former owner.
1843 static inline void skb_orphan(struct sk_buff *skb)
1845 if (skb->destructor)
1846 skb->destructor(skb);
1847 skb->destructor = NULL;
1852 * skb_orphan_frags - orphan the frags contained in a buffer
1853 * @skb: buffer to orphan frags from
1854 * @gfp_mask: allocation mask for replacement pages
1856 * For each frag in the SKB which needs a destructor (i.e. has an
1857 * owner) create a copy of that frag and release the original
1858 * page by calling the destructor.
1860 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
1862 if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY)))
1864 return skb_copy_ubufs(skb, gfp_mask);
1868 * __skb_queue_purge - empty a list
1869 * @list: list to empty
1871 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1872 * the list and one reference dropped. This function does not take the
1873 * list lock and the caller must hold the relevant locks to use it.
1875 extern void skb_queue_purge(struct sk_buff_head *list);
1876 static inline void __skb_queue_purge(struct sk_buff_head *list)
1878 struct sk_buff *skb;
1879 while ((skb = __skb_dequeue(list)) != NULL)
1883 #define NETDEV_FRAG_PAGE_MAX_ORDER get_order(32768)
1884 #define NETDEV_FRAG_PAGE_MAX_SIZE (PAGE_SIZE << NETDEV_FRAG_PAGE_MAX_ORDER)
1885 #define NETDEV_PAGECNT_MAX_BIAS NETDEV_FRAG_PAGE_MAX_SIZE
1887 extern void *netdev_alloc_frag(unsigned int fragsz);
1889 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1890 unsigned int length,
1894 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1895 * @dev: network device to receive on
1896 * @length: length to allocate
1898 * Allocate a new &sk_buff and assign it a usage count of one. The
1899 * buffer has unspecified headroom built in. Users should allocate
1900 * the headroom they think they need without accounting for the
1901 * built in space. The built in space is used for optimisations.
1903 * %NULL is returned if there is no free memory. Although this function
1904 * allocates memory it can be called from an interrupt.
1906 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1907 unsigned int length)
1909 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1912 /* legacy helper around __netdev_alloc_skb() */
1913 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1916 return __netdev_alloc_skb(NULL, length, gfp_mask);
1919 /* legacy helper around netdev_alloc_skb() */
1920 static inline struct sk_buff *dev_alloc_skb(unsigned int length)
1922 return netdev_alloc_skb(NULL, length);
1926 static inline struct sk_buff *__netdev_alloc_skb_ip_align(struct net_device *dev,
1927 unsigned int length, gfp_t gfp)
1929 struct sk_buff *skb = __netdev_alloc_skb(dev, length + NET_IP_ALIGN, gfp);
1931 if (NET_IP_ALIGN && skb)
1932 skb_reserve(skb, NET_IP_ALIGN);
1936 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
1937 unsigned int length)
1939 return __netdev_alloc_skb_ip_align(dev, length, GFP_ATOMIC);
1943 * __skb_alloc_page - allocate pages for ps-rx on a skb and preserve pfmemalloc data
1944 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
1945 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
1946 * @order: size of the allocation
1948 * Allocate a new page.
1950 * %NULL is returned if there is no free memory.
1952 static inline struct page *__skb_alloc_pages(gfp_t gfp_mask,
1953 struct sk_buff *skb,
1958 gfp_mask |= __GFP_COLD;
1960 if (!(gfp_mask & __GFP_NOMEMALLOC))
1961 gfp_mask |= __GFP_MEMALLOC;
1963 page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, order);
1964 if (skb && page && page->pfmemalloc)
1965 skb->pfmemalloc = true;
1971 * __skb_alloc_page - allocate a page for ps-rx for a given skb and preserve pfmemalloc data
1972 * @gfp_mask: alloc_pages_node mask. Set __GFP_NOMEMALLOC if not for network packet RX
1973 * @skb: skb to set pfmemalloc on if __GFP_MEMALLOC is used
1975 * Allocate a new page.
1977 * %NULL is returned if there is no free memory.
1979 static inline struct page *__skb_alloc_page(gfp_t gfp_mask,
1980 struct sk_buff *skb)
1982 return __skb_alloc_pages(gfp_mask, skb, 0);
1986 * skb_propagate_pfmemalloc - Propagate pfmemalloc if skb is allocated after RX page
1987 * @page: The page that was allocated from skb_alloc_page
1988 * @skb: The skb that may need pfmemalloc set
1990 static inline void skb_propagate_pfmemalloc(struct page *page,
1991 struct sk_buff *skb)
1993 if (page && page->pfmemalloc)
1994 skb->pfmemalloc = true;
1998 * skb_frag_page - retrieve the page refered to by a paged fragment
1999 * @frag: the paged fragment
2001 * Returns the &struct page associated with @frag.
2003 static inline struct page *skb_frag_page(const skb_frag_t *frag)
2005 return frag->page.p;
2009 * __skb_frag_ref - take an addition reference on a paged fragment.
2010 * @frag: the paged fragment
2012 * Takes an additional reference on the paged fragment @frag.
2014 static inline void __skb_frag_ref(skb_frag_t *frag)
2016 get_page(skb_frag_page(frag));
2020 * skb_frag_ref - take an addition reference on a paged fragment of an skb.
2022 * @f: the fragment offset.
2024 * Takes an additional reference on the @f'th paged fragment of @skb.
2026 static inline void skb_frag_ref(struct sk_buff *skb, int f)
2028 __skb_frag_ref(&skb_shinfo(skb)->frags[f]);
2032 * __skb_frag_unref - release a reference on a paged fragment.
2033 * @frag: the paged fragment
2035 * Releases a reference on the paged fragment @frag.
2037 static inline void __skb_frag_unref(skb_frag_t *frag)
2039 put_page(skb_frag_page(frag));
2043 * skb_frag_unref - release a reference on a paged fragment of an skb.
2045 * @f: the fragment offset
2047 * Releases a reference on the @f'th paged fragment of @skb.
2049 static inline void skb_frag_unref(struct sk_buff *skb, int f)
2051 __skb_frag_unref(&skb_shinfo(skb)->frags[f]);
2055 * skb_frag_address - gets the address of the data contained in a paged fragment
2056 * @frag: the paged fragment buffer
2058 * Returns the address of the data within @frag. The page must already
2061 static inline void *skb_frag_address(const skb_frag_t *frag)
2063 return page_address(skb_frag_page(frag)) + frag->page_offset;
2067 * skb_frag_address_safe - gets the address of the data contained in a paged fragment
2068 * @frag: the paged fragment buffer
2070 * Returns the address of the data within @frag. Checks that the page
2071 * is mapped and returns %NULL otherwise.
2073 static inline void *skb_frag_address_safe(const skb_frag_t *frag)
2075 void *ptr = page_address(skb_frag_page(frag));
2079 return ptr + frag->page_offset;
2083 * __skb_frag_set_page - sets the page contained in a paged fragment
2084 * @frag: the paged fragment
2085 * @page: the page to set
2087 * Sets the fragment @frag to contain @page.
2089 static inline void __skb_frag_set_page(skb_frag_t *frag, struct page *page)
2091 frag->page.p = page;
2095 * skb_frag_set_page - sets the page contained in a paged fragment of an skb
2097 * @f: the fragment offset
2098 * @page: the page to set
2100 * Sets the @f'th fragment of @skb to contain @page.
2102 static inline void skb_frag_set_page(struct sk_buff *skb, int f,
2105 __skb_frag_set_page(&skb_shinfo(skb)->frags[f], page);
2109 * skb_frag_dma_map - maps a paged fragment via the DMA API
2110 * @dev: the device to map the fragment to
2111 * @frag: the paged fragment to map
2112 * @offset: the offset within the fragment (starting at the
2113 * fragment's own offset)
2114 * @size: the number of bytes to map
2115 * @dir: the direction of the mapping (%PCI_DMA_*)
2117 * Maps the page associated with @frag to @device.
2119 static inline dma_addr_t skb_frag_dma_map(struct device *dev,
2120 const skb_frag_t *frag,
2121 size_t offset, size_t size,
2122 enum dma_data_direction dir)
2124 return dma_map_page(dev, skb_frag_page(frag),
2125 frag->page_offset + offset, size, dir);
2128 static inline struct sk_buff *pskb_copy(struct sk_buff *skb,
2131 return __pskb_copy(skb, skb_headroom(skb), gfp_mask);
2135 * skb_clone_writable - is the header of a clone writable
2136 * @skb: buffer to check
2137 * @len: length up to which to write
2139 * Returns true if modifying the header part of the cloned buffer
2140 * does not requires the data to be copied.
2142 static inline int skb_clone_writable(const struct sk_buff *skb, unsigned int len)
2144 return !skb_header_cloned(skb) &&
2145 skb_headroom(skb) + len <= skb->hdr_len;
2148 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
2153 if (headroom > skb_headroom(skb))
2154 delta = headroom - skb_headroom(skb);
2156 if (delta || cloned)
2157 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
2163 * skb_cow - copy header of skb when it is required
2164 * @skb: buffer to cow
2165 * @headroom: needed headroom
2167 * If the skb passed lacks sufficient headroom or its data part
2168 * is shared, data is reallocated. If reallocation fails, an error
2169 * is returned and original skb is not changed.
2171 * The result is skb with writable area skb->head...skb->tail
2172 * and at least @headroom of space at head.
2174 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
2176 return __skb_cow(skb, headroom, skb_cloned(skb));
2180 * skb_cow_head - skb_cow but only making the head writable
2181 * @skb: buffer to cow
2182 * @headroom: needed headroom
2184 * This function is identical to skb_cow except that we replace the
2185 * skb_cloned check by skb_header_cloned. It should be used when
2186 * you only need to push on some header and do not need to modify
2189 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
2191 return __skb_cow(skb, headroom, skb_header_cloned(skb));
2195 * skb_padto - pad an skbuff up to a minimal size
2196 * @skb: buffer to pad
2197 * @len: minimal length
2199 * Pads up a buffer to ensure the trailing bytes exist and are
2200 * blanked. If the buffer already contains sufficient data it
2201 * is untouched. Otherwise it is extended. Returns zero on
2202 * success. The skb is freed on error.
2205 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
2207 unsigned int size = skb->len;
2208 if (likely(size >= len))
2210 return skb_pad(skb, len - size);
2213 static inline int skb_add_data(struct sk_buff *skb,
2214 char __user *from, int copy)
2216 const int off = skb->len;
2218 if (skb->ip_summed == CHECKSUM_NONE) {
2220 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
2223 skb->csum = csum_block_add(skb->csum, csum, off);
2226 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
2229 __skb_trim(skb, off);
2233 static inline bool skb_can_coalesce(struct sk_buff *skb, int i,
2234 const struct page *page, int off)
2237 const struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
2239 return page == skb_frag_page(frag) &&
2240 off == frag->page_offset + skb_frag_size(frag);
2245 static inline int __skb_linearize(struct sk_buff *skb)
2247 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
2251 * skb_linearize - convert paged skb to linear one
2252 * @skb: buffer to linarize
2254 * If there is no free memory -ENOMEM is returned, otherwise zero
2255 * is returned and the old skb data released.
2257 static inline int skb_linearize(struct sk_buff *skb)
2259 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
2263 * skb_has_shared_frag - can any frag be overwritten
2264 * @skb: buffer to test
2266 * Return true if the skb has at least one frag that might be modified
2267 * by an external entity (as in vmsplice()/sendfile())
2269 static inline bool skb_has_shared_frag(const struct sk_buff *skb)
2271 return skb_is_nonlinear(skb) &&
2272 skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
2276 * skb_linearize_cow - make sure skb is linear and writable
2277 * @skb: buffer to process
2279 * If there is no free memory -ENOMEM is returned, otherwise zero
2280 * is returned and the old skb data released.
2282 static inline int skb_linearize_cow(struct sk_buff *skb)
2284 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
2285 __skb_linearize(skb) : 0;
2289 * skb_postpull_rcsum - update checksum for received skb after pull
2290 * @skb: buffer to update
2291 * @start: start of data before pull
2292 * @len: length of data pulled
2294 * After doing a pull on a received packet, you need to call this to
2295 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
2296 * CHECKSUM_NONE so that it can be recomputed from scratch.
2299 static inline void skb_postpull_rcsum(struct sk_buff *skb,
2300 const void *start, unsigned int len)
2302 if (skb->ip_summed == CHECKSUM_COMPLETE)
2303 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
2306 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
2309 * pskb_trim_rcsum - trim received skb and update checksum
2310 * @skb: buffer to trim
2313 * This is exactly the same as pskb_trim except that it ensures the
2314 * checksum of received packets are still valid after the operation.
2317 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
2319 if (likely(len >= skb->len))
2321 if (skb->ip_summed == CHECKSUM_COMPLETE)
2322 skb->ip_summed = CHECKSUM_NONE;
2323 return __pskb_trim(skb, len);
2326 #define skb_queue_walk(queue, skb) \
2327 for (skb = (queue)->next; \
2328 skb != (struct sk_buff *)(queue); \
2331 #define skb_queue_walk_safe(queue, skb, tmp) \
2332 for (skb = (queue)->next, tmp = skb->next; \
2333 skb != (struct sk_buff *)(queue); \
2334 skb = tmp, tmp = skb->next)
2336 #define skb_queue_walk_from(queue, skb) \
2337 for (; skb != (struct sk_buff *)(queue); \
2340 #define skb_queue_walk_from_safe(queue, skb, tmp) \
2341 for (tmp = skb->next; \
2342 skb != (struct sk_buff *)(queue); \
2343 skb = tmp, tmp = skb->next)
2345 #define skb_queue_reverse_walk(queue, skb) \
2346 for (skb = (queue)->prev; \
2347 skb != (struct sk_buff *)(queue); \
2350 #define skb_queue_reverse_walk_safe(queue, skb, tmp) \
2351 for (skb = (queue)->prev, tmp = skb->prev; \
2352 skb != (struct sk_buff *)(queue); \
2353 skb = tmp, tmp = skb->prev)
2355 #define skb_queue_reverse_walk_from_safe(queue, skb, tmp) \
2356 for (tmp = skb->prev; \
2357 skb != (struct sk_buff *)(queue); \
2358 skb = tmp, tmp = skb->prev)
2360 static inline bool skb_has_frag_list(const struct sk_buff *skb)
2362 return skb_shinfo(skb)->frag_list != NULL;
2365 static inline void skb_frag_list_init(struct sk_buff *skb)
2367 skb_shinfo(skb)->frag_list = NULL;
2370 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
2372 frag->next = skb_shinfo(skb)->frag_list;
2373 skb_shinfo(skb)->frag_list = frag;
2376 #define skb_walk_frags(skb, iter) \
2377 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
2379 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
2380 int *peeked, int *off, int *err);
2381 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
2382 int noblock, int *err);
2383 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
2384 struct poll_table_struct *wait);
2385 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
2386 int offset, struct iovec *to,
2388 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
2391 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
2393 const struct iovec *from,
2396 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from,
2398 const struct iovec *to,
2401 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
2402 extern void skb_free_datagram_locked(struct sock *sk,
2403 struct sk_buff *skb);
2404 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
2405 unsigned int flags);
2406 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
2407 int len, __wsum csum);
2408 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
2410 extern int skb_store_bits(struct sk_buff *skb, int offset,
2411 const void *from, int len);
2412 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
2413 int offset, u8 *to, int len,
2415 extern int skb_splice_bits(struct sk_buff *skb,
2416 unsigned int offset,
2417 struct pipe_inode_info *pipe,
2419 unsigned int flags);
2420 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
2421 extern void skb_split(struct sk_buff *skb,
2422 struct sk_buff *skb1, const u32 len);
2423 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
2426 extern struct sk_buff *skb_segment(struct sk_buff *skb,
2427 netdev_features_t features);
2429 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
2430 int len, void *buffer)
2432 int hlen = skb_headlen(skb);
2434 if (hlen - offset >= len)
2435 return skb->data + offset;
2437 if (skb_copy_bits(skb, offset, buffer, len) < 0)
2443 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
2445 const unsigned int len)
2447 memcpy(to, skb->data, len);
2450 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
2451 const int offset, void *to,
2452 const unsigned int len)
2454 memcpy(to, skb->data + offset, len);
2457 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
2459 const unsigned int len)
2461 memcpy(skb->data, from, len);
2464 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
2467 const unsigned int len)
2469 memcpy(skb->data + offset, from, len);
2472 extern void skb_init(void);
2474 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
2480 * skb_get_timestamp - get timestamp from a skb
2481 * @skb: skb to get stamp from
2482 * @stamp: pointer to struct timeval to store stamp in
2484 * Timestamps are stored in the skb as offsets to a base timestamp.
2485 * This function converts the offset back to a struct timeval and stores
2488 static inline void skb_get_timestamp(const struct sk_buff *skb,
2489 struct timeval *stamp)
2491 *stamp = ktime_to_timeval(skb->tstamp);
2494 static inline void skb_get_timestampns(const struct sk_buff *skb,
2495 struct timespec *stamp)
2497 *stamp = ktime_to_timespec(skb->tstamp);
2500 static inline void __net_timestamp(struct sk_buff *skb)
2502 skb->tstamp = ktime_get_real();
2505 static inline ktime_t net_timedelta(ktime_t t)
2507 return ktime_sub(ktime_get_real(), t);
2510 static inline ktime_t net_invalid_timestamp(void)
2512 return ktime_set(0, 0);
2515 extern void skb_timestamping_init(void);
2517 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING
2519 extern void skb_clone_tx_timestamp(struct sk_buff *skb);
2520 extern bool skb_defer_rx_timestamp(struct sk_buff *skb);
2522 #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */
2524 static inline void skb_clone_tx_timestamp(struct sk_buff *skb)
2528 static inline bool skb_defer_rx_timestamp(struct sk_buff *skb)
2533 #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */
2536 * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps
2538 * PHY drivers may accept clones of transmitted packets for
2539 * timestamping via their phy_driver.txtstamp method. These drivers
2540 * must call this function to return the skb back to the stack, with
2541 * or without a timestamp.
2543 * @skb: clone of the the original outgoing packet
2544 * @hwtstamps: hardware time stamps, may be NULL if not available
2547 void skb_complete_tx_timestamp(struct sk_buff *skb,
2548 struct skb_shared_hwtstamps *hwtstamps);
2551 * skb_tstamp_tx - queue clone of skb with send time stamps
2552 * @orig_skb: the original outgoing packet
2553 * @hwtstamps: hardware time stamps, may be NULL if not available
2555 * If the skb has a socket associated, then this function clones the
2556 * skb (thus sharing the actual data and optional structures), stores
2557 * the optional hardware time stamping information (if non NULL) or
2558 * generates a software time stamp (otherwise), then queues the clone
2559 * to the error queue of the socket. Errors are silently ignored.
2561 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
2562 struct skb_shared_hwtstamps *hwtstamps);
2564 static inline void sw_tx_timestamp(struct sk_buff *skb)
2566 if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP &&
2567 !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
2568 skb_tstamp_tx(skb, NULL);
2572 * skb_tx_timestamp() - Driver hook for transmit timestamping
2574 * Ethernet MAC Drivers should call this function in their hard_xmit()
2575 * function immediately before giving the sk_buff to the MAC hardware.
2577 * @skb: A socket buffer.
2579 static inline void skb_tx_timestamp(struct sk_buff *skb)
2581 skb_clone_tx_timestamp(skb);
2582 sw_tx_timestamp(skb);
2586 * skb_complete_wifi_ack - deliver skb with wifi status
2588 * @skb: the original outgoing packet
2589 * @acked: ack status
2592 void skb_complete_wifi_ack(struct sk_buff *skb, bool acked);
2594 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
2595 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
2597 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
2599 return skb->ip_summed & CHECKSUM_UNNECESSARY;
2603 * skb_checksum_complete - Calculate checksum of an entire packet
2604 * @skb: packet to process
2606 * This function calculates the checksum over the entire packet plus
2607 * the value of skb->csum. The latter can be used to supply the
2608 * checksum of a pseudo header as used by TCP/UDP. It returns the
2611 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
2612 * this function can be used to verify that checksum on received
2613 * packets. In that case the function should return zero if the
2614 * checksum is correct. In particular, this function will return zero
2615 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
2616 * hardware has already verified the correctness of the checksum.
2618 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
2620 return skb_csum_unnecessary(skb) ?
2621 0 : __skb_checksum_complete(skb);
2624 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2625 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
2626 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
2628 if (nfct && atomic_dec_and_test(&nfct->use))
2629 nf_conntrack_destroy(nfct);
2631 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
2634 atomic_inc(&nfct->use);
2637 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2638 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
2641 atomic_inc(&skb->users);
2643 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
2649 #ifdef CONFIG_BRIDGE_NETFILTER
2650 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
2652 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
2655 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
2658 atomic_inc(&nf_bridge->use);
2660 #endif /* CONFIG_BRIDGE_NETFILTER */
2661 static inline void nf_reset(struct sk_buff *skb)
2663 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2664 nf_conntrack_put(skb->nfct);
2667 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2668 nf_conntrack_put_reasm(skb->nfct_reasm);
2669 skb->nfct_reasm = NULL;
2671 #ifdef CONFIG_BRIDGE_NETFILTER
2672 nf_bridge_put(skb->nf_bridge);
2673 skb->nf_bridge = NULL;
2677 /* Note: This doesn't put any conntrack and bridge info in dst. */
2678 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2680 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2681 dst->nfct = src->nfct;
2682 nf_conntrack_get(src->nfct);
2683 dst->nfctinfo = src->nfctinfo;
2685 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2686 dst->nfct_reasm = src->nfct_reasm;
2687 nf_conntrack_get_reasm(src->nfct_reasm);
2689 #ifdef CONFIG_BRIDGE_NETFILTER
2690 dst->nf_bridge = src->nf_bridge;
2691 nf_bridge_get(src->nf_bridge);
2695 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
2697 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
2698 nf_conntrack_put(dst->nfct);
2700 #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED
2701 nf_conntrack_put_reasm(dst->nfct_reasm);
2703 #ifdef CONFIG_BRIDGE_NETFILTER
2704 nf_bridge_put(dst->nf_bridge);
2706 __nf_copy(dst, src);
2709 #ifdef CONFIG_NETWORK_SECMARK
2710 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2712 to->secmark = from->secmark;
2715 static inline void skb_init_secmark(struct sk_buff *skb)
2720 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2723 static inline void skb_init_secmark(struct sk_buff *skb)
2727 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
2729 skb->queue_mapping = queue_mapping;
2732 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
2734 return skb->queue_mapping;
2737 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
2739 to->queue_mapping = from->queue_mapping;
2742 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
2744 skb->queue_mapping = rx_queue + 1;
2747 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2749 return skb->queue_mapping - 1;
2752 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2754 return skb->queue_mapping != 0;
2757 extern u16 __skb_tx_hash(const struct net_device *dev,
2758 const struct sk_buff *skb,
2759 unsigned int num_tx_queues);
2762 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2767 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2773 /* Keeps track of mac header offset relative to skb->head.
2774 * It is useful for TSO of Tunneling protocol. e.g. GRE.
2775 * For non-tunnel skb it points to skb_mac_header() and for
2776 * tunnel skb it points to outer mac header. */
2780 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)(skb)->cb)
2782 static inline int skb_tnl_header_len(const struct sk_buff *inner_skb)
2784 return (skb_mac_header(inner_skb) - inner_skb->head) -
2785 SKB_GSO_CB(inner_skb)->mac_offset;
2788 static inline bool skb_is_gso(const struct sk_buff *skb)
2790 return skb_shinfo(skb)->gso_size;
2793 static inline bool skb_is_gso_v6(const struct sk_buff *skb)
2795 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2798 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2800 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2802 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2803 * wanted then gso_type will be set. */
2804 const struct skb_shared_info *shinfo = skb_shinfo(skb);
2806 if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 &&
2807 unlikely(shinfo->gso_type == 0)) {
2808 __skb_warn_lro_forwarding(skb);
2814 static inline void skb_forward_csum(struct sk_buff *skb)
2816 /* Unfortunately we don't support this one. Any brave souls? */
2817 if (skb->ip_summed == CHECKSUM_COMPLETE)
2818 skb->ip_summed = CHECKSUM_NONE;
2822 * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE
2823 * @skb: skb to check
2825 * fresh skbs have their ip_summed set to CHECKSUM_NONE.
2826 * Instead of forcing ip_summed to CHECKSUM_NONE, we can
2827 * use this helper, to document places where we make this assertion.
2829 static inline void skb_checksum_none_assert(const struct sk_buff *skb)
2832 BUG_ON(skb->ip_summed != CHECKSUM_NONE);
2836 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2839 * skb_head_is_locked - Determine if the skb->head is locked down
2840 * @skb: skb to check
2842 * The head on skbs build around a head frag can be removed if they are
2843 * not cloned. This function returns true if the skb head is locked down
2844 * due to either being allocated via kmalloc, or by being a clone with
2845 * multiple references to the head.
2847 static inline bool skb_head_is_locked(const struct sk_buff *skb)
2849 return !skb->head_frag || skb_cloned(skb);
2851 #endif /* __KERNEL__ */
2852 #endif /* _LINUX_SKBUFF_H */