2 * Definitions for the 'struct sk_buff' memory handlers.
5 * Alan Cox, <gw4pts@gw4pts.ampr.org>
6 * Florian La Roche, <rzsfl@rz.uni-sb.de>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 #ifndef _LINUX_SKBUFF_H
15 #define _LINUX_SKBUFF_H
17 #include <linux/kernel.h>
18 #include <linux/kmemcheck.h>
19 #include <linux/compiler.h>
20 #include <linux/time.h>
21 #include <linux/cache.h>
23 #include <asm/atomic.h>
24 #include <asm/types.h>
25 #include <linux/spinlock.h>
26 #include <linux/net.h>
27 #include <linux/textsearch.h>
28 #include <net/checksum.h>
29 #include <linux/rcupdate.h>
30 #include <linux/dmaengine.h>
31 #include <linux/hrtimer.h>
33 /* Don't change this without changing skb_csum_unnecessary! */
34 #define CHECKSUM_NONE 0
35 #define CHECKSUM_UNNECESSARY 1
36 #define CHECKSUM_COMPLETE 2
37 #define CHECKSUM_PARTIAL 3
39 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
40 ~(SMP_CACHE_BYTES - 1))
41 #define SKB_WITH_OVERHEAD(X) \
42 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
43 #define SKB_MAX_ORDER(X, ORDER) \
44 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
45 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
46 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
48 /* A. Checksumming of received packets by device.
50 * NONE: device failed to checksum this packet.
51 * skb->csum is undefined.
53 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
54 * skb->csum is undefined.
55 * It is bad option, but, unfortunately, many of vendors do this.
56 * Apparently with secret goal to sell you new device, when you
57 * will add new protocol to your host. F.e. IPv6. 8)
59 * COMPLETE: the most generic way. Device supplied checksum of _all_
60 * the packet as seen by netif_rx in skb->csum.
61 * NOTE: Even if device supports only some protocols, but
62 * is able to produce some skb->csum, it MUST use COMPLETE,
65 * PARTIAL: identical to the case for output below. This may occur
66 * on a packet received directly from another Linux OS, e.g.,
67 * a virtualised Linux kernel on the same host. The packet can
68 * be treated in the same way as UNNECESSARY except that on
69 * output (i.e., forwarding) the checksum must be filled in
70 * by the OS or the hardware.
72 * B. Checksumming on output.
74 * NONE: skb is checksummed by protocol or csum is not required.
76 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
77 * from skb->csum_start to the end and to record the checksum
78 * at skb->csum_start + skb->csum_offset.
80 * Device must show its capabilities in dev->features, set
81 * at device setup time.
82 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
84 * NETIF_F_NO_CSUM - loopback or reliable single hop media.
85 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
86 * TCP/UDP over IPv4. Sigh. Vendors like this
87 * way by an unknown reason. Though, see comment above
88 * about CHECKSUM_UNNECESSARY. 8)
89 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
91 * Any questions? No questions, good. --ANK
96 struct pipe_inode_info;
98 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
104 #ifdef CONFIG_BRIDGE_NETFILTER
105 struct nf_bridge_info {
107 struct net_device *physindev;
108 struct net_device *physoutdev;
110 unsigned long data[32 / sizeof(unsigned long)];
114 struct sk_buff_head {
115 /* These two members must be first. */
116 struct sk_buff *next;
117 struct sk_buff *prev;
125 /* To allow 64K frame to be packed as single skb without frag_list */
126 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
128 typedef struct skb_frag_struct skb_frag_t;
130 struct skb_frag_struct {
136 #define HAVE_HW_TIME_STAMP
139 * struct skb_shared_hwtstamps - hardware time stamps
140 * @hwtstamp: hardware time stamp transformed into duration
141 * since arbitrary point in time
142 * @syststamp: hwtstamp transformed to system time base
144 * Software time stamps generated by ktime_get_real() are stored in
145 * skb->tstamp. The relation between the different kinds of time
146 * stamps is as follows:
148 * syststamp and tstamp can be compared against each other in
149 * arbitrary combinations. The accuracy of a
150 * syststamp/tstamp/"syststamp from other device" comparison is
151 * limited by the accuracy of the transformation into system time
152 * base. This depends on the device driver and its underlying
155 * hwtstamps can only be compared against other hwtstamps from
158 * This structure is attached to packets as part of the
159 * &skb_shared_info. Use skb_hwtstamps() to get a pointer.
161 struct skb_shared_hwtstamps {
167 * struct skb_shared_tx - instructions for time stamping of outgoing packets
168 * @hardware: generate hardware time stamp
169 * @software: generate software time stamp
170 * @in_progress: device driver is going to provide
171 * hardware time stamp
172 * @flags: all shared_tx flags
174 * These flags are attached to packets as part of the
175 * &skb_shared_info. Use skb_tx() to get a pointer.
177 union skb_shared_tx {
186 /* This data is invariant across clones and lives at
187 * the end of the header data, ie. at skb->end.
189 struct skb_shared_info {
191 unsigned short nr_frags;
192 unsigned short gso_size;
193 /* Warning: this field is not always filled in (UFO)! */
194 unsigned short gso_segs;
195 unsigned short gso_type;
197 union skb_shared_tx tx_flags;
198 struct sk_buff *frag_list;
199 struct skb_shared_hwtstamps hwtstamps;
200 skb_frag_t frags[MAX_SKB_FRAGS];
201 /* Intermediate layers must ensure that destructor_arg
202 * remains valid until skb destructor */
203 void * destructor_arg;
206 /* We divide dataref into two halves. The higher 16 bits hold references
207 * to the payload part of skb->data. The lower 16 bits hold references to
208 * the entire skb->data. A clone of a headerless skb holds the length of
209 * the header in skb->hdr_len.
211 * All users must obey the rule that the skb->data reference count must be
212 * greater than or equal to the payload reference count.
214 * Holding a reference to the payload part means that the user does not
215 * care about modifications to the header part of skb->data.
217 #define SKB_DATAREF_SHIFT 16
218 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
222 SKB_FCLONE_UNAVAILABLE,
228 SKB_GSO_TCPV4 = 1 << 0,
229 SKB_GSO_UDP = 1 << 1,
231 /* This indicates the skb is from an untrusted source. */
232 SKB_GSO_DODGY = 1 << 2,
234 /* This indicates the tcp segment has CWR set. */
235 SKB_GSO_TCP_ECN = 1 << 3,
237 SKB_GSO_TCPV6 = 1 << 4,
239 SKB_GSO_FCOE = 1 << 5,
242 #if BITS_PER_LONG > 32
243 #define NET_SKBUFF_DATA_USES_OFFSET 1
246 #ifdef NET_SKBUFF_DATA_USES_OFFSET
247 typedef unsigned int sk_buff_data_t;
249 typedef unsigned char *sk_buff_data_t;
253 * struct sk_buff - socket buffer
254 * @next: Next buffer in list
255 * @prev: Previous buffer in list
256 * @sk: Socket we are owned by
257 * @tstamp: Time we arrived
258 * @dev: Device we arrived on/are leaving by
259 * @transport_header: Transport layer header
260 * @network_header: Network layer header
261 * @mac_header: Link layer header
262 * @_skb_dst: destination entry
263 * @sp: the security path, used for xfrm
264 * @cb: Control buffer. Free for use by every layer. Put private vars here
265 * @len: Length of actual data
266 * @data_len: Data length
267 * @mac_len: Length of link layer header
268 * @hdr_len: writable header length of cloned skb
269 * @csum: Checksum (must include start/offset pair)
270 * @csum_start: Offset from skb->head where checksumming should start
271 * @csum_offset: Offset from csum_start where checksum should be stored
272 * @local_df: allow local fragmentation
273 * @cloned: Head may be cloned (check refcnt to be sure)
274 * @nohdr: Payload reference only, must not modify header
275 * @pkt_type: Packet class
276 * @fclone: skbuff clone status
277 * @ip_summed: Driver fed us an IP checksum
278 * @priority: Packet queueing priority
279 * @users: User count - see {datagram,tcp}.c
280 * @protocol: Packet protocol from driver
281 * @truesize: Buffer size
282 * @head: Head of buffer
283 * @data: Data head pointer
284 * @tail: Tail pointer
286 * @destructor: Destruct function
287 * @mark: Generic packet mark
288 * @nfct: Associated connection, if any
289 * @ipvs_property: skbuff is owned by ipvs
290 * @peeked: this packet has been seen already, so stats have been
291 * done for it, don't do them again
292 * @nf_trace: netfilter packet trace flag
293 * @nfctinfo: Relationship of this skb to the connection
294 * @nfct_reasm: netfilter conntrack re-assembly pointer
295 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
296 * @skb_iif: ifindex of device we arrived on
297 * @rxhash: the packet hash computed on receive
298 * @queue_mapping: Queue mapping for multiqueue devices
299 * @tc_index: Traffic control index
300 * @tc_verd: traffic control verdict
301 * @ndisc_nodetype: router type (from link layer)
302 * @dma_cookie: a cookie to one of several possible DMA operations
303 * done by skb DMA functions
304 * @secmark: security marking
305 * @vlan_tci: vlan tag control information
309 /* These two members must be first. */
310 struct sk_buff *next;
311 struct sk_buff *prev;
316 struct net_device *dev;
319 * This is the control buffer. It is free to use for every
320 * layer. Please put your private variables there. If you
321 * want to keep them across layers you have to do a skb_clone()
322 * first. This is owned by whoever has the skb queued ATM.
324 char cb[48] __aligned(8);
326 unsigned long _skb_dst;
342 kmemcheck_bitfield_begin(flags1);
353 kmemcheck_bitfield_end(flags1);
356 void (*destructor)(struct sk_buff *skb);
357 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
358 struct nf_conntrack *nfct;
359 struct sk_buff *nfct_reasm;
361 #ifdef CONFIG_BRIDGE_NETFILTER
362 struct nf_bridge_info *nf_bridge;
366 #ifdef CONFIG_NET_SCHED
367 __u16 tc_index; /* traffic control index */
368 #ifdef CONFIG_NET_CLS_ACT
369 __u16 tc_verd; /* traffic control verdict */
375 kmemcheck_bitfield_begin(flags2);
376 __u16 queue_mapping:16;
377 #ifdef CONFIG_IPV6_NDISC_NODETYPE
378 __u8 ndisc_nodetype:2;
380 kmemcheck_bitfield_end(flags2);
384 #ifdef CONFIG_NET_DMA
385 dma_cookie_t dma_cookie;
387 #ifdef CONFIG_NETWORK_SECMARK
397 sk_buff_data_t transport_header;
398 sk_buff_data_t network_header;
399 sk_buff_data_t mac_header;
400 /* These elements must be at the end, see alloc_skb() for details. */
405 unsigned int truesize;
411 * Handling routines are only of interest to the kernel
413 #include <linux/slab.h>
415 #include <asm/system.h>
417 static inline struct dst_entry *skb_dst(const struct sk_buff *skb)
419 return (struct dst_entry *)skb->_skb_dst;
422 static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)
424 skb->_skb_dst = (unsigned long)dst;
427 static inline struct rtable *skb_rtable(const struct sk_buff *skb)
429 return (struct rtable *)skb_dst(skb);
432 extern void kfree_skb(struct sk_buff *skb);
433 extern void consume_skb(struct sk_buff *skb);
434 extern void __kfree_skb(struct sk_buff *skb);
435 extern struct sk_buff *__alloc_skb(unsigned int size,
436 gfp_t priority, int fclone, int node);
437 static inline struct sk_buff *alloc_skb(unsigned int size,
440 return __alloc_skb(size, priority, 0, -1);
443 static inline struct sk_buff *alloc_skb_fclone(unsigned int size,
446 return __alloc_skb(size, priority, 1, -1);
449 extern int skb_recycle_check(struct sk_buff *skb, int skb_size);
451 extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src);
452 extern struct sk_buff *skb_clone(struct sk_buff *skb,
454 extern struct sk_buff *skb_copy(const struct sk_buff *skb,
456 extern struct sk_buff *pskb_copy(struct sk_buff *skb,
458 extern int pskb_expand_head(struct sk_buff *skb,
459 int nhead, int ntail,
461 extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb,
462 unsigned int headroom);
463 extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
464 int newheadroom, int newtailroom,
466 extern int skb_to_sgvec(struct sk_buff *skb,
467 struct scatterlist *sg, int offset,
469 extern int skb_cow_data(struct sk_buff *skb, int tailbits,
470 struct sk_buff **trailer);
471 extern int skb_pad(struct sk_buff *skb, int pad);
472 #define dev_kfree_skb(a) consume_skb(a)
473 extern void skb_over_panic(struct sk_buff *skb, int len,
475 extern void skb_under_panic(struct sk_buff *skb, int len,
478 extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
479 int getfrag(void *from, char *to, int offset,
480 int len,int odd, struct sk_buff *skb),
481 void *from, int length);
483 struct skb_seq_state {
487 __u32 stepped_offset;
488 struct sk_buff *root_skb;
489 struct sk_buff *cur_skb;
493 extern void skb_prepare_seq_read(struct sk_buff *skb,
494 unsigned int from, unsigned int to,
495 struct skb_seq_state *st);
496 extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
497 struct skb_seq_state *st);
498 extern void skb_abort_seq_read(struct skb_seq_state *st);
500 extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from,
501 unsigned int to, struct ts_config *config,
502 struct ts_state *state);
504 #ifdef NET_SKBUFF_DATA_USES_OFFSET
505 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
507 return skb->head + skb->end;
510 static inline unsigned char *skb_end_pointer(const struct sk_buff *skb)
517 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
519 static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
521 return &skb_shinfo(skb)->hwtstamps;
524 static inline union skb_shared_tx *skb_tx(struct sk_buff *skb)
526 return &skb_shinfo(skb)->tx_flags;
530 * skb_queue_empty - check if a queue is empty
533 * Returns true if the queue is empty, false otherwise.
535 static inline int skb_queue_empty(const struct sk_buff_head *list)
537 return list->next == (struct sk_buff *)list;
541 * skb_queue_is_last - check if skb is the last entry in the queue
545 * Returns true if @skb is the last buffer on the list.
547 static inline bool skb_queue_is_last(const struct sk_buff_head *list,
548 const struct sk_buff *skb)
550 return (skb->next == (struct sk_buff *) list);
554 * skb_queue_is_first - check if skb is the first entry in the queue
558 * Returns true if @skb is the first buffer on the list.
560 static inline bool skb_queue_is_first(const struct sk_buff_head *list,
561 const struct sk_buff *skb)
563 return (skb->prev == (struct sk_buff *) list);
567 * skb_queue_next - return the next packet in the queue
569 * @skb: current buffer
571 * Return the next packet in @list after @skb. It is only valid to
572 * call this if skb_queue_is_last() evaluates to false.
574 static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list,
575 const struct sk_buff *skb)
577 /* This BUG_ON may seem severe, but if we just return then we
578 * are going to dereference garbage.
580 BUG_ON(skb_queue_is_last(list, skb));
585 * skb_queue_prev - return the prev packet in the queue
587 * @skb: current buffer
589 * Return the prev packet in @list before @skb. It is only valid to
590 * call this if skb_queue_is_first() evaluates to false.
592 static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list,
593 const struct sk_buff *skb)
595 /* This BUG_ON may seem severe, but if we just return then we
596 * are going to dereference garbage.
598 BUG_ON(skb_queue_is_first(list, skb));
603 * skb_get - reference buffer
604 * @skb: buffer to reference
606 * Makes another reference to a socket buffer and returns a pointer
609 static inline struct sk_buff *skb_get(struct sk_buff *skb)
611 atomic_inc(&skb->users);
616 * If users == 1, we are the only owner and are can avoid redundant
621 * skb_cloned - is the buffer a clone
622 * @skb: buffer to check
624 * Returns true if the buffer was generated with skb_clone() and is
625 * one of multiple shared copies of the buffer. Cloned buffers are
626 * shared data so must not be written to under normal circumstances.
628 static inline int skb_cloned(const struct sk_buff *skb)
630 return skb->cloned &&
631 (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1;
635 * skb_header_cloned - is the header a clone
636 * @skb: buffer to check
638 * Returns true if modifying the header part of the buffer requires
639 * the data to be copied.
641 static inline int skb_header_cloned(const struct sk_buff *skb)
648 dataref = atomic_read(&skb_shinfo(skb)->dataref);
649 dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT);
654 * skb_header_release - release reference to header
655 * @skb: buffer to operate on
657 * Drop a reference to the header part of the buffer. This is done
658 * by acquiring a payload reference. You must not read from the header
659 * part of skb->data after this.
661 static inline void skb_header_release(struct sk_buff *skb)
665 atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref);
669 * skb_shared - is the buffer shared
670 * @skb: buffer to check
672 * Returns true if more than one person has a reference to this
675 static inline int skb_shared(const struct sk_buff *skb)
677 return atomic_read(&skb->users) != 1;
681 * skb_share_check - check if buffer is shared and if so clone it
682 * @skb: buffer to check
683 * @pri: priority for memory allocation
685 * If the buffer is shared the buffer is cloned and the old copy
686 * drops a reference. A new clone with a single reference is returned.
687 * If the buffer is not shared the original buffer is returned. When
688 * being called from interrupt status or with spinlocks held pri must
691 * NULL is returned on a memory allocation failure.
693 static inline struct sk_buff *skb_share_check(struct sk_buff *skb,
696 might_sleep_if(pri & __GFP_WAIT);
697 if (skb_shared(skb)) {
698 struct sk_buff *nskb = skb_clone(skb, pri);
706 * Copy shared buffers into a new sk_buff. We effectively do COW on
707 * packets to handle cases where we have a local reader and forward
708 * and a couple of other messy ones. The normal one is tcpdumping
709 * a packet thats being forwarded.
713 * skb_unshare - make a copy of a shared buffer
714 * @skb: buffer to check
715 * @pri: priority for memory allocation
717 * If the socket buffer is a clone then this function creates a new
718 * copy of the data, drops a reference count on the old copy and returns
719 * the new copy with the reference count at 1. If the buffer is not a clone
720 * the original buffer is returned. When called with a spinlock held or
721 * from interrupt state @pri must be %GFP_ATOMIC
723 * %NULL is returned on a memory allocation failure.
725 static inline struct sk_buff *skb_unshare(struct sk_buff *skb,
728 might_sleep_if(pri & __GFP_WAIT);
729 if (skb_cloned(skb)) {
730 struct sk_buff *nskb = skb_copy(skb, pri);
731 kfree_skb(skb); /* Free our shared copy */
738 * skb_peek - peek at the head of an &sk_buff_head
739 * @list_: list to peek at
741 * Peek an &sk_buff. Unlike most other operations you _MUST_
742 * be careful with this one. A peek leaves the buffer on the
743 * list and someone else may run off with it. You must hold
744 * the appropriate locks or have a private queue to do this.
746 * Returns %NULL for an empty list or a pointer to the head element.
747 * The reference count is not incremented and the reference is therefore
748 * volatile. Use with caution.
750 static inline struct sk_buff *skb_peek(struct sk_buff_head *list_)
752 struct sk_buff *list = ((struct sk_buff *)list_)->next;
753 if (list == (struct sk_buff *)list_)
759 * skb_peek_tail - peek at the tail of an &sk_buff_head
760 * @list_: list to peek at
762 * Peek an &sk_buff. Unlike most other operations you _MUST_
763 * be careful with this one. A peek leaves the buffer on the
764 * list and someone else may run off with it. You must hold
765 * the appropriate locks or have a private queue to do this.
767 * Returns %NULL for an empty list or a pointer to the tail element.
768 * The reference count is not incremented and the reference is therefore
769 * volatile. Use with caution.
771 static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_)
773 struct sk_buff *list = ((struct sk_buff *)list_)->prev;
774 if (list == (struct sk_buff *)list_)
780 * skb_queue_len - get queue length
781 * @list_: list to measure
783 * Return the length of an &sk_buff queue.
785 static inline __u32 skb_queue_len(const struct sk_buff_head *list_)
791 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
792 * @list: queue to initialize
794 * This initializes only the list and queue length aspects of
795 * an sk_buff_head object. This allows to initialize the list
796 * aspects of an sk_buff_head without reinitializing things like
797 * the spinlock. It can also be used for on-stack sk_buff_head
798 * objects where the spinlock is known to not be used.
800 static inline void __skb_queue_head_init(struct sk_buff_head *list)
802 list->prev = list->next = (struct sk_buff *)list;
807 * This function creates a split out lock class for each invocation;
808 * this is needed for now since a whole lot of users of the skb-queue
809 * infrastructure in drivers have different locking usage (in hardirq)
810 * than the networking core (in softirq only). In the long run either the
811 * network layer or drivers should need annotation to consolidate the
812 * main types of usage into 3 classes.
814 static inline void skb_queue_head_init(struct sk_buff_head *list)
816 spin_lock_init(&list->lock);
817 __skb_queue_head_init(list);
820 static inline void skb_queue_head_init_class(struct sk_buff_head *list,
821 struct lock_class_key *class)
823 skb_queue_head_init(list);
824 lockdep_set_class(&list->lock, class);
828 * Insert an sk_buff on a list.
830 * The "__skb_xxxx()" functions are the non-atomic ones that
831 * can only be called with interrupts disabled.
833 extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list);
834 static inline void __skb_insert(struct sk_buff *newsk,
835 struct sk_buff *prev, struct sk_buff *next,
836 struct sk_buff_head *list)
840 next->prev = prev->next = newsk;
844 static inline void __skb_queue_splice(const struct sk_buff_head *list,
845 struct sk_buff *prev,
846 struct sk_buff *next)
848 struct sk_buff *first = list->next;
849 struct sk_buff *last = list->prev;
859 * skb_queue_splice - join two skb lists, this is designed for stacks
860 * @list: the new list to add
861 * @head: the place to add it in the first list
863 static inline void skb_queue_splice(const struct sk_buff_head *list,
864 struct sk_buff_head *head)
866 if (!skb_queue_empty(list)) {
867 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
868 head->qlen += list->qlen;
873 * skb_queue_splice - join two skb lists and reinitialise the emptied list
874 * @list: the new list to add
875 * @head: the place to add it in the first list
877 * The list at @list is reinitialised
879 static inline void skb_queue_splice_init(struct sk_buff_head *list,
880 struct sk_buff_head *head)
882 if (!skb_queue_empty(list)) {
883 __skb_queue_splice(list, (struct sk_buff *) head, head->next);
884 head->qlen += list->qlen;
885 __skb_queue_head_init(list);
890 * skb_queue_splice_tail - join two skb lists, each list being a queue
891 * @list: the new list to add
892 * @head: the place to add it in the first list
894 static inline void skb_queue_splice_tail(const struct sk_buff_head *list,
895 struct sk_buff_head *head)
897 if (!skb_queue_empty(list)) {
898 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
899 head->qlen += list->qlen;
904 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
905 * @list: the new list to add
906 * @head: the place to add it in the first list
908 * Each of the lists is a queue.
909 * The list at @list is reinitialised
911 static inline void skb_queue_splice_tail_init(struct sk_buff_head *list,
912 struct sk_buff_head *head)
914 if (!skb_queue_empty(list)) {
915 __skb_queue_splice(list, head->prev, (struct sk_buff *) head);
916 head->qlen += list->qlen;
917 __skb_queue_head_init(list);
922 * __skb_queue_after - queue a buffer at the list head
924 * @prev: place after this buffer
925 * @newsk: buffer to queue
927 * Queue a buffer int the middle of a list. This function takes no locks
928 * and you must therefore hold required locks before calling it.
930 * A buffer cannot be placed on two lists at the same time.
932 static inline void __skb_queue_after(struct sk_buff_head *list,
933 struct sk_buff *prev,
934 struct sk_buff *newsk)
936 __skb_insert(newsk, prev, prev->next, list);
939 extern void skb_append(struct sk_buff *old, struct sk_buff *newsk,
940 struct sk_buff_head *list);
942 static inline void __skb_queue_before(struct sk_buff_head *list,
943 struct sk_buff *next,
944 struct sk_buff *newsk)
946 __skb_insert(newsk, next->prev, next, list);
950 * __skb_queue_head - queue a buffer at the list head
952 * @newsk: buffer to queue
954 * Queue a buffer at the start of a list. This function takes no locks
955 * and you must therefore hold required locks before calling it.
957 * A buffer cannot be placed on two lists at the same time.
959 extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk);
960 static inline void __skb_queue_head(struct sk_buff_head *list,
961 struct sk_buff *newsk)
963 __skb_queue_after(list, (struct sk_buff *)list, newsk);
967 * __skb_queue_tail - queue a buffer at the list tail
969 * @newsk: buffer to queue
971 * Queue a buffer at the end of a list. This function takes no locks
972 * and you must therefore hold required locks before calling it.
974 * A buffer cannot be placed on two lists at the same time.
976 extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk);
977 static inline void __skb_queue_tail(struct sk_buff_head *list,
978 struct sk_buff *newsk)
980 __skb_queue_before(list, (struct sk_buff *)list, newsk);
984 * remove sk_buff from list. _Must_ be called atomically, and with
987 extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list);
988 static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list)
990 struct sk_buff *next, *prev;
995 skb->next = skb->prev = NULL;
1001 * __skb_dequeue - remove from the head of the queue
1002 * @list: list to dequeue from
1004 * Remove the head of the list. This function does not take any locks
1005 * so must be used with appropriate locks held only. The head item is
1006 * returned or %NULL if the list is empty.
1008 extern struct sk_buff *skb_dequeue(struct sk_buff_head *list);
1009 static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list)
1011 struct sk_buff *skb = skb_peek(list);
1013 __skb_unlink(skb, list);
1018 * __skb_dequeue_tail - remove from the tail of the queue
1019 * @list: list to dequeue from
1021 * Remove the tail of the list. This function does not take any locks
1022 * so must be used with appropriate locks held only. The tail item is
1023 * returned or %NULL if the list is empty.
1025 extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list);
1026 static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list)
1028 struct sk_buff *skb = skb_peek_tail(list);
1030 __skb_unlink(skb, list);
1035 static inline int skb_is_nonlinear(const struct sk_buff *skb)
1037 return skb->data_len;
1040 static inline unsigned int skb_headlen(const struct sk_buff *skb)
1042 return skb->len - skb->data_len;
1045 static inline int skb_pagelen(const struct sk_buff *skb)
1049 for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--)
1050 len += skb_shinfo(skb)->frags[i].size;
1051 return len + skb_headlen(skb);
1054 static inline void skb_fill_page_desc(struct sk_buff *skb, int i,
1055 struct page *page, int off, int size)
1057 skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
1060 frag->page_offset = off;
1062 skb_shinfo(skb)->nr_frags = i + 1;
1065 extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page,
1068 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1069 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frags(skb))
1070 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1072 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1073 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1075 return skb->head + skb->tail;
1078 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1080 skb->tail = skb->data - skb->head;
1083 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1085 skb_reset_tail_pointer(skb);
1086 skb->tail += offset;
1088 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1089 static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb)
1094 static inline void skb_reset_tail_pointer(struct sk_buff *skb)
1096 skb->tail = skb->data;
1099 static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset)
1101 skb->tail = skb->data + offset;
1104 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1107 * Add data to an sk_buff
1109 extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len);
1110 static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len)
1112 unsigned char *tmp = skb_tail_pointer(skb);
1113 SKB_LINEAR_ASSERT(skb);
1119 extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len);
1120 static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len)
1127 extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len);
1128 static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len)
1131 BUG_ON(skb->len < skb->data_len);
1132 return skb->data += len;
1135 extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta);
1137 static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len)
1139 if (len > skb_headlen(skb) &&
1140 !__pskb_pull_tail(skb, len - skb_headlen(skb)))
1143 return skb->data += len;
1146 static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len)
1148 return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
1151 static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
1153 if (likely(len <= skb_headlen(skb)))
1155 if (unlikely(len > skb->len))
1157 return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
1161 * skb_headroom - bytes at buffer head
1162 * @skb: buffer to check
1164 * Return the number of bytes of free space at the head of an &sk_buff.
1166 static inline unsigned int skb_headroom(const struct sk_buff *skb)
1168 return skb->data - skb->head;
1172 * skb_tailroom - bytes at buffer end
1173 * @skb: buffer to check
1175 * Return the number of bytes of free space at the tail of an sk_buff
1177 static inline int skb_tailroom(const struct sk_buff *skb)
1179 return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail;
1183 * skb_reserve - adjust headroom
1184 * @skb: buffer to alter
1185 * @len: bytes to move
1187 * Increase the headroom of an empty &sk_buff by reducing the tail
1188 * room. This is only allowed for an empty buffer.
1190 static inline void skb_reserve(struct sk_buff *skb, int len)
1196 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1197 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1199 return skb->head + skb->transport_header;
1202 static inline void skb_reset_transport_header(struct sk_buff *skb)
1204 skb->transport_header = skb->data - skb->head;
1207 static inline void skb_set_transport_header(struct sk_buff *skb,
1210 skb_reset_transport_header(skb);
1211 skb->transport_header += offset;
1214 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1216 return skb->head + skb->network_header;
1219 static inline void skb_reset_network_header(struct sk_buff *skb)
1221 skb->network_header = skb->data - skb->head;
1224 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1226 skb_reset_network_header(skb);
1227 skb->network_header += offset;
1230 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1232 return skb->head + skb->mac_header;
1235 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1237 return skb->mac_header != ~0U;
1240 static inline void skb_reset_mac_header(struct sk_buff *skb)
1242 skb->mac_header = skb->data - skb->head;
1245 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1247 skb_reset_mac_header(skb);
1248 skb->mac_header += offset;
1251 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1253 static inline unsigned char *skb_transport_header(const struct sk_buff *skb)
1255 return skb->transport_header;
1258 static inline void skb_reset_transport_header(struct sk_buff *skb)
1260 skb->transport_header = skb->data;
1263 static inline void skb_set_transport_header(struct sk_buff *skb,
1266 skb->transport_header = skb->data + offset;
1269 static inline unsigned char *skb_network_header(const struct sk_buff *skb)
1271 return skb->network_header;
1274 static inline void skb_reset_network_header(struct sk_buff *skb)
1276 skb->network_header = skb->data;
1279 static inline void skb_set_network_header(struct sk_buff *skb, const int offset)
1281 skb->network_header = skb->data + offset;
1284 static inline unsigned char *skb_mac_header(const struct sk_buff *skb)
1286 return skb->mac_header;
1289 static inline int skb_mac_header_was_set(const struct sk_buff *skb)
1291 return skb->mac_header != NULL;
1294 static inline void skb_reset_mac_header(struct sk_buff *skb)
1296 skb->mac_header = skb->data;
1299 static inline void skb_set_mac_header(struct sk_buff *skb, const int offset)
1301 skb->mac_header = skb->data + offset;
1303 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1305 static inline int skb_transport_offset(const struct sk_buff *skb)
1307 return skb_transport_header(skb) - skb->data;
1310 static inline u32 skb_network_header_len(const struct sk_buff *skb)
1312 return skb->transport_header - skb->network_header;
1315 static inline int skb_network_offset(const struct sk_buff *skb)
1317 return skb_network_header(skb) - skb->data;
1321 * CPUs often take a performance hit when accessing unaligned memory
1322 * locations. The actual performance hit varies, it can be small if the
1323 * hardware handles it or large if we have to take an exception and fix it
1326 * Since an ethernet header is 14 bytes network drivers often end up with
1327 * the IP header at an unaligned offset. The IP header can be aligned by
1328 * shifting the start of the packet by 2 bytes. Drivers should do this
1331 * skb_reserve(skb, NET_IP_ALIGN);
1333 * The downside to this alignment of the IP header is that the DMA is now
1334 * unaligned. On some architectures the cost of an unaligned DMA is high
1335 * and this cost outweighs the gains made by aligning the IP header.
1337 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1340 #ifndef NET_IP_ALIGN
1341 #define NET_IP_ALIGN 2
1345 * The networking layer reserves some headroom in skb data (via
1346 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1347 * the header has to grow. In the default case, if the header has to grow
1348 * 32 bytes or less we avoid the reallocation.
1350 * Unfortunately this headroom changes the DMA alignment of the resulting
1351 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1352 * on some architectures. An architecture can override this value,
1353 * perhaps setting it to a cacheline in size (since that will maintain
1354 * cacheline alignment of the DMA). It must be a power of 2.
1356 * Various parts of the networking layer expect at least 32 bytes of
1357 * headroom, you should not reduce this.
1360 #define NET_SKB_PAD 32
1363 extern int ___pskb_trim(struct sk_buff *skb, unsigned int len);
1365 static inline void __skb_trim(struct sk_buff *skb, unsigned int len)
1367 if (unlikely(skb->data_len)) {
1372 skb_set_tail_pointer(skb, len);
1375 extern void skb_trim(struct sk_buff *skb, unsigned int len);
1377 static inline int __pskb_trim(struct sk_buff *skb, unsigned int len)
1380 return ___pskb_trim(skb, len);
1381 __skb_trim(skb, len);
1385 static inline int pskb_trim(struct sk_buff *skb, unsigned int len)
1387 return (len < skb->len) ? __pskb_trim(skb, len) : 0;
1391 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1392 * @skb: buffer to alter
1395 * This is identical to pskb_trim except that the caller knows that
1396 * the skb is not cloned so we should never get an error due to out-
1399 static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len)
1401 int err = pskb_trim(skb, len);
1406 * skb_orphan - orphan a buffer
1407 * @skb: buffer to orphan
1409 * If a buffer currently has an owner then we call the owner's
1410 * destructor function and make the @skb unowned. The buffer continues
1411 * to exist but is no longer charged to its former owner.
1413 static inline void skb_orphan(struct sk_buff *skb)
1415 if (skb->destructor)
1416 skb->destructor(skb);
1417 skb->destructor = NULL;
1422 * __skb_queue_purge - empty a list
1423 * @list: list to empty
1425 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1426 * the list and one reference dropped. This function does not take the
1427 * list lock and the caller must hold the relevant locks to use it.
1429 extern void skb_queue_purge(struct sk_buff_head *list);
1430 static inline void __skb_queue_purge(struct sk_buff_head *list)
1432 struct sk_buff *skb;
1433 while ((skb = __skb_dequeue(list)) != NULL)
1438 * __dev_alloc_skb - allocate an skbuff for receiving
1439 * @length: length to allocate
1440 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1442 * Allocate a new &sk_buff and assign it a usage count of one. The
1443 * buffer has unspecified headroom built in. Users should allocate
1444 * the headroom they think they need without accounting for the
1445 * built in space. The built in space is used for optimisations.
1447 * %NULL is returned if there is no free memory.
1449 static inline struct sk_buff *__dev_alloc_skb(unsigned int length,
1452 struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask);
1454 skb_reserve(skb, NET_SKB_PAD);
1458 extern struct sk_buff *dev_alloc_skb(unsigned int length);
1460 extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev,
1461 unsigned int length, gfp_t gfp_mask);
1464 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1465 * @dev: network device to receive on
1466 * @length: length to allocate
1468 * Allocate a new &sk_buff and assign it a usage count of one. The
1469 * buffer has unspecified headroom built in. Users should allocate
1470 * the headroom they think they need without accounting for the
1471 * built in space. The built in space is used for optimisations.
1473 * %NULL is returned if there is no free memory. Although this function
1474 * allocates memory it can be called from an interrupt.
1476 static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev,
1477 unsigned int length)
1479 return __netdev_alloc_skb(dev, length, GFP_ATOMIC);
1482 static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev,
1483 unsigned int length)
1485 struct sk_buff *skb = netdev_alloc_skb(dev, length + NET_IP_ALIGN);
1487 if (NET_IP_ALIGN && skb)
1488 skb_reserve(skb, NET_IP_ALIGN);
1492 extern struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask);
1495 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1496 * @dev: network device to receive on
1498 * Allocate a new page node local to the specified device.
1500 * %NULL is returned if there is no free memory.
1502 static inline struct page *netdev_alloc_page(struct net_device *dev)
1504 return __netdev_alloc_page(dev, GFP_ATOMIC);
1507 static inline void netdev_free_page(struct net_device *dev, struct page *page)
1513 * skb_clone_writable - is the header of a clone writable
1514 * @skb: buffer to check
1515 * @len: length up to which to write
1517 * Returns true if modifying the header part of the cloned buffer
1518 * does not requires the data to be copied.
1520 static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len)
1522 return !skb_header_cloned(skb) &&
1523 skb_headroom(skb) + len <= skb->hdr_len;
1526 static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom,
1531 if (headroom < NET_SKB_PAD)
1532 headroom = NET_SKB_PAD;
1533 if (headroom > skb_headroom(skb))
1534 delta = headroom - skb_headroom(skb);
1536 if (delta || cloned)
1537 return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0,
1543 * skb_cow - copy header of skb when it is required
1544 * @skb: buffer to cow
1545 * @headroom: needed headroom
1547 * If the skb passed lacks sufficient headroom or its data part
1548 * is shared, data is reallocated. If reallocation fails, an error
1549 * is returned and original skb is not changed.
1551 * The result is skb with writable area skb->head...skb->tail
1552 * and at least @headroom of space at head.
1554 static inline int skb_cow(struct sk_buff *skb, unsigned int headroom)
1556 return __skb_cow(skb, headroom, skb_cloned(skb));
1560 * skb_cow_head - skb_cow but only making the head writable
1561 * @skb: buffer to cow
1562 * @headroom: needed headroom
1564 * This function is identical to skb_cow except that we replace the
1565 * skb_cloned check by skb_header_cloned. It should be used when
1566 * you only need to push on some header and do not need to modify
1569 static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom)
1571 return __skb_cow(skb, headroom, skb_header_cloned(skb));
1575 * skb_padto - pad an skbuff up to a minimal size
1576 * @skb: buffer to pad
1577 * @len: minimal length
1579 * Pads up a buffer to ensure the trailing bytes exist and are
1580 * blanked. If the buffer already contains sufficient data it
1581 * is untouched. Otherwise it is extended. Returns zero on
1582 * success. The skb is freed on error.
1585 static inline int skb_padto(struct sk_buff *skb, unsigned int len)
1587 unsigned int size = skb->len;
1588 if (likely(size >= len))
1590 return skb_pad(skb, len - size);
1593 static inline int skb_add_data(struct sk_buff *skb,
1594 char __user *from, int copy)
1596 const int off = skb->len;
1598 if (skb->ip_summed == CHECKSUM_NONE) {
1600 __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy),
1603 skb->csum = csum_block_add(skb->csum, csum, off);
1606 } else if (!copy_from_user(skb_put(skb, copy), from, copy))
1609 __skb_trim(skb, off);
1613 static inline int skb_can_coalesce(struct sk_buff *skb, int i,
1614 struct page *page, int off)
1617 struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1];
1619 return page == frag->page &&
1620 off == frag->page_offset + frag->size;
1625 static inline int __skb_linearize(struct sk_buff *skb)
1627 return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM;
1631 * skb_linearize - convert paged skb to linear one
1632 * @skb: buffer to linarize
1634 * If there is no free memory -ENOMEM is returned, otherwise zero
1635 * is returned and the old skb data released.
1637 static inline int skb_linearize(struct sk_buff *skb)
1639 return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0;
1643 * skb_linearize_cow - make sure skb is linear and writable
1644 * @skb: buffer to process
1646 * If there is no free memory -ENOMEM is returned, otherwise zero
1647 * is returned and the old skb data released.
1649 static inline int skb_linearize_cow(struct sk_buff *skb)
1651 return skb_is_nonlinear(skb) || skb_cloned(skb) ?
1652 __skb_linearize(skb) : 0;
1656 * skb_postpull_rcsum - update checksum for received skb after pull
1657 * @skb: buffer to update
1658 * @start: start of data before pull
1659 * @len: length of data pulled
1661 * After doing a pull on a received packet, you need to call this to
1662 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1663 * CHECKSUM_NONE so that it can be recomputed from scratch.
1666 static inline void skb_postpull_rcsum(struct sk_buff *skb,
1667 const void *start, unsigned int len)
1669 if (skb->ip_summed == CHECKSUM_COMPLETE)
1670 skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0));
1673 unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
1676 * pskb_trim_rcsum - trim received skb and update checksum
1677 * @skb: buffer to trim
1680 * This is exactly the same as pskb_trim except that it ensures the
1681 * checksum of received packets are still valid after the operation.
1684 static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len)
1686 if (likely(len >= skb->len))
1688 if (skb->ip_summed == CHECKSUM_COMPLETE)
1689 skb->ip_summed = CHECKSUM_NONE;
1690 return __pskb_trim(skb, len);
1693 #define skb_queue_walk(queue, skb) \
1694 for (skb = (queue)->next; \
1695 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1698 #define skb_queue_walk_safe(queue, skb, tmp) \
1699 for (skb = (queue)->next, tmp = skb->next; \
1700 skb != (struct sk_buff *)(queue); \
1701 skb = tmp, tmp = skb->next)
1703 #define skb_queue_walk_from(queue, skb) \
1704 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1707 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1708 for (tmp = skb->next; \
1709 skb != (struct sk_buff *)(queue); \
1710 skb = tmp, tmp = skb->next)
1712 #define skb_queue_reverse_walk(queue, skb) \
1713 for (skb = (queue)->prev; \
1714 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1718 static inline bool skb_has_frags(const struct sk_buff *skb)
1720 return skb_shinfo(skb)->frag_list != NULL;
1723 static inline void skb_frag_list_init(struct sk_buff *skb)
1725 skb_shinfo(skb)->frag_list = NULL;
1728 static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag)
1730 frag->next = skb_shinfo(skb)->frag_list;
1731 skb_shinfo(skb)->frag_list = frag;
1734 #define skb_walk_frags(skb, iter) \
1735 for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)
1737 extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
1738 int *peeked, int *err);
1739 extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
1740 int noblock, int *err);
1741 extern unsigned int datagram_poll(struct file *file, struct socket *sock,
1742 struct poll_table_struct *wait);
1743 extern int skb_copy_datagram_iovec(const struct sk_buff *from,
1744 int offset, struct iovec *to,
1746 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb,
1749 extern int skb_copy_datagram_from_iovec(struct sk_buff *skb,
1751 const struct iovec *from,
1754 extern int skb_copy_datagram_const_iovec(const struct sk_buff *from,
1756 const struct iovec *to,
1759 extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb);
1760 extern void skb_free_datagram_locked(struct sock *sk,
1761 struct sk_buff *skb);
1762 extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb,
1763 unsigned int flags);
1764 extern __wsum skb_checksum(const struct sk_buff *skb, int offset,
1765 int len, __wsum csum);
1766 extern int skb_copy_bits(const struct sk_buff *skb, int offset,
1768 extern int skb_store_bits(struct sk_buff *skb, int offset,
1769 const void *from, int len);
1770 extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb,
1771 int offset, u8 *to, int len,
1773 extern int skb_splice_bits(struct sk_buff *skb,
1774 unsigned int offset,
1775 struct pipe_inode_info *pipe,
1777 unsigned int flags);
1778 extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to);
1779 extern void skb_split(struct sk_buff *skb,
1780 struct sk_buff *skb1, const u32 len);
1781 extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb,
1784 extern struct sk_buff *skb_segment(struct sk_buff *skb, int features);
1786 static inline void *skb_header_pointer(const struct sk_buff *skb, int offset,
1787 int len, void *buffer)
1789 int hlen = skb_headlen(skb);
1791 if (hlen - offset >= len)
1792 return skb->data + offset;
1794 if (skb_copy_bits(skb, offset, buffer, len) < 0)
1800 static inline void skb_copy_from_linear_data(const struct sk_buff *skb,
1802 const unsigned int len)
1804 memcpy(to, skb->data, len);
1807 static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb,
1808 const int offset, void *to,
1809 const unsigned int len)
1811 memcpy(to, skb->data + offset, len);
1814 static inline void skb_copy_to_linear_data(struct sk_buff *skb,
1816 const unsigned int len)
1818 memcpy(skb->data, from, len);
1821 static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb,
1824 const unsigned int len)
1826 memcpy(skb->data + offset, from, len);
1829 extern void skb_init(void);
1831 static inline ktime_t skb_get_ktime(const struct sk_buff *skb)
1837 * skb_get_timestamp - get timestamp from a skb
1838 * @skb: skb to get stamp from
1839 * @stamp: pointer to struct timeval to store stamp in
1841 * Timestamps are stored in the skb as offsets to a base timestamp.
1842 * This function converts the offset back to a struct timeval and stores
1845 static inline void skb_get_timestamp(const struct sk_buff *skb,
1846 struct timeval *stamp)
1848 *stamp = ktime_to_timeval(skb->tstamp);
1851 static inline void skb_get_timestampns(const struct sk_buff *skb,
1852 struct timespec *stamp)
1854 *stamp = ktime_to_timespec(skb->tstamp);
1857 static inline void __net_timestamp(struct sk_buff *skb)
1859 skb->tstamp = ktime_get_real();
1862 static inline ktime_t net_timedelta(ktime_t t)
1864 return ktime_sub(ktime_get_real(), t);
1867 static inline ktime_t net_invalid_timestamp(void)
1869 return ktime_set(0, 0);
1873 * skb_tstamp_tx - queue clone of skb with send time stamps
1874 * @orig_skb: the original outgoing packet
1875 * @hwtstamps: hardware time stamps, may be NULL if not available
1877 * If the skb has a socket associated, then this function clones the
1878 * skb (thus sharing the actual data and optional structures), stores
1879 * the optional hardware time stamping information (if non NULL) or
1880 * generates a software time stamp (otherwise), then queues the clone
1881 * to the error queue of the socket. Errors are silently ignored.
1883 extern void skb_tstamp_tx(struct sk_buff *orig_skb,
1884 struct skb_shared_hwtstamps *hwtstamps);
1886 extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len);
1887 extern __sum16 __skb_checksum_complete(struct sk_buff *skb);
1889 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
1891 return skb->ip_summed & CHECKSUM_UNNECESSARY;
1895 * skb_checksum_complete - Calculate checksum of an entire packet
1896 * @skb: packet to process
1898 * This function calculates the checksum over the entire packet plus
1899 * the value of skb->csum. The latter can be used to supply the
1900 * checksum of a pseudo header as used by TCP/UDP. It returns the
1903 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1904 * this function can be used to verify that checksum on received
1905 * packets. In that case the function should return zero if the
1906 * checksum is correct. In particular, this function will return zero
1907 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1908 * hardware has already verified the correctness of the checksum.
1910 static inline __sum16 skb_checksum_complete(struct sk_buff *skb)
1912 return skb_csum_unnecessary(skb) ?
1913 0 : __skb_checksum_complete(skb);
1916 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1917 extern void nf_conntrack_destroy(struct nf_conntrack *nfct);
1918 static inline void nf_conntrack_put(struct nf_conntrack *nfct)
1920 if (nfct && atomic_dec_and_test(&nfct->use))
1921 nf_conntrack_destroy(nfct);
1923 static inline void nf_conntrack_get(struct nf_conntrack *nfct)
1926 atomic_inc(&nfct->use);
1928 static inline void nf_conntrack_get_reasm(struct sk_buff *skb)
1931 atomic_inc(&skb->users);
1933 static inline void nf_conntrack_put_reasm(struct sk_buff *skb)
1939 #ifdef CONFIG_BRIDGE_NETFILTER
1940 static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge)
1942 if (nf_bridge && atomic_dec_and_test(&nf_bridge->use))
1945 static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge)
1948 atomic_inc(&nf_bridge->use);
1950 #endif /* CONFIG_BRIDGE_NETFILTER */
1951 static inline void nf_reset(struct sk_buff *skb)
1953 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1954 nf_conntrack_put(skb->nfct);
1956 nf_conntrack_put_reasm(skb->nfct_reasm);
1957 skb->nfct_reasm = NULL;
1959 #ifdef CONFIG_BRIDGE_NETFILTER
1960 nf_bridge_put(skb->nf_bridge);
1961 skb->nf_bridge = NULL;
1965 /* Note: This doesn't put any conntrack and bridge info in dst. */
1966 static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1968 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1969 dst->nfct = src->nfct;
1970 nf_conntrack_get(src->nfct);
1971 dst->nfctinfo = src->nfctinfo;
1972 dst->nfct_reasm = src->nfct_reasm;
1973 nf_conntrack_get_reasm(src->nfct_reasm);
1975 #ifdef CONFIG_BRIDGE_NETFILTER
1976 dst->nf_bridge = src->nf_bridge;
1977 nf_bridge_get(src->nf_bridge);
1981 static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src)
1983 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1984 nf_conntrack_put(dst->nfct);
1985 nf_conntrack_put_reasm(dst->nfct_reasm);
1987 #ifdef CONFIG_BRIDGE_NETFILTER
1988 nf_bridge_put(dst->nf_bridge);
1990 __nf_copy(dst, src);
1993 #ifdef CONFIG_NETWORK_SECMARK
1994 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
1996 to->secmark = from->secmark;
1999 static inline void skb_init_secmark(struct sk_buff *skb)
2004 static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from)
2007 static inline void skb_init_secmark(struct sk_buff *skb)
2011 static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping)
2013 skb->queue_mapping = queue_mapping;
2016 static inline u16 skb_get_queue_mapping(const struct sk_buff *skb)
2018 return skb->queue_mapping;
2021 static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from)
2023 to->queue_mapping = from->queue_mapping;
2026 static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue)
2028 skb->queue_mapping = rx_queue + 1;
2031 static inline u16 skb_get_rx_queue(const struct sk_buff *skb)
2033 return skb->queue_mapping - 1;
2036 static inline bool skb_rx_queue_recorded(const struct sk_buff *skb)
2038 return (skb->queue_mapping != 0);
2041 extern u16 skb_tx_hash(const struct net_device *dev,
2042 const struct sk_buff *skb);
2045 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2050 static inline struct sec_path *skb_sec_path(struct sk_buff *skb)
2056 static inline int skb_is_gso(const struct sk_buff *skb)
2058 return skb_shinfo(skb)->gso_size;
2061 static inline int skb_is_gso_v6(const struct sk_buff *skb)
2063 return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
2066 extern void __skb_warn_lro_forwarding(const struct sk_buff *skb);
2068 static inline bool skb_warn_if_lro(const struct sk_buff *skb)
2070 /* LRO sets gso_size but not gso_type, whereas if GSO is really
2071 * wanted then gso_type will be set. */
2072 struct skb_shared_info *shinfo = skb_shinfo(skb);
2073 if (shinfo->gso_size != 0 && unlikely(shinfo->gso_type == 0)) {
2074 __skb_warn_lro_forwarding(skb);
2080 static inline void skb_forward_csum(struct sk_buff *skb)
2082 /* Unfortunately we don't support this one. Any brave souls? */
2083 if (skb->ip_summed == CHECKSUM_COMPLETE)
2084 skb->ip_summed = CHECKSUM_NONE;
2087 bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
2088 #endif /* __KERNEL__ */
2089 #endif /* _LINUX_SKBUFF_H */