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/compiler.h>
19 #include <linux/time.h>
20 #include <linux/cache.h>
22 #include <asm/atomic.h>
23 #include <asm/types.h>
24 #include <linux/spinlock.h>
25 #include <linux/net.h>
26 #include <linux/textsearch.h>
27 #include <net/checksum.h>
28 #include <linux/rcupdate.h>
29 #include <linux/dmaengine.h>
30 #include <linux/hrtimer.h>
32 #define HAVE_ALLOC_SKB /* For the drivers to know */
33 #define HAVE_ALIGNABLE_SKB /* Ditto 8) */
35 /* Don't change this without changing skb_csum_unnecessary! */
36 #define CHECKSUM_NONE 0
37 #define CHECKSUM_UNNECESSARY 1
38 #define CHECKSUM_COMPLETE 2
39 #define CHECKSUM_PARTIAL 3
41 #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \
42 ~(SMP_CACHE_BYTES - 1))
43 #define SKB_WITH_OVERHEAD(X) \
44 ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
45 #define SKB_MAX_ORDER(X, ORDER) \
46 SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X))
47 #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0))
48 #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2))
50 /* A. Checksumming of received packets by device.
52 * NONE: device failed to checksum this packet.
53 * skb->csum is undefined.
55 * UNNECESSARY: device parsed packet and wouldbe verified checksum.
56 * skb->csum is undefined.
57 * It is bad option, but, unfortunately, many of vendors do this.
58 * Apparently with secret goal to sell you new device, when you
59 * will add new protocol to your host. F.e. IPv6. 8)
61 * COMPLETE: the most generic way. Device supplied checksum of _all_
62 * the packet as seen by netif_rx in skb->csum.
63 * NOTE: Even if device supports only some protocols, but
64 * is able to produce some skb->csum, it MUST use COMPLETE,
67 * PARTIAL: identical to the case for output below. This may occur
68 * on a packet received directly from another Linux OS, e.g.,
69 * a virtualised Linux kernel on the same host. The packet can
70 * be treated in the same way as UNNECESSARY except that on
71 * output (i.e., forwarding) the checksum must be filled in
72 * by the OS or the hardware.
74 * B. Checksumming on output.
76 * NONE: skb is checksummed by protocol or csum is not required.
78 * PARTIAL: device is required to csum packet as seen by hard_start_xmit
79 * from skb->csum_start to the end and to record the checksum
80 * at skb->csum_start + skb->csum_offset.
82 * Device must show its capabilities in dev->features, set
83 * at device setup time.
84 * NETIF_F_HW_CSUM - it is clever device, it is able to checksum
86 * NETIF_F_NO_CSUM - loopback or reliable single hop media.
87 * NETIF_F_IP_CSUM - device is dumb. It is able to csum only
88 * TCP/UDP over IPv4. Sigh. Vendors like this
89 * way by an unknown reason. Though, see comment above
90 * about CHECKSUM_UNNECESSARY. 8)
91 * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead.
93 * Any questions? No questions, good. --ANK
98 struct pipe_inode_info
;
100 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
101 struct nf_conntrack
{
106 #ifdef CONFIG_BRIDGE_NETFILTER
107 struct nf_bridge_info
{
109 struct net_device
*physindev
;
110 struct net_device
*physoutdev
;
112 unsigned long data
[32 / sizeof(unsigned long)];
116 struct sk_buff_head
{
117 /* These two members must be first. */
118 struct sk_buff
*next
;
119 struct sk_buff
*prev
;
127 /* To allow 64K frame to be packed as single skb without frag_list */
128 #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
130 typedef struct skb_frag_struct skb_frag_t
;
132 struct skb_frag_struct
{
138 /* This data is invariant across clones and lives at
139 * the end of the header data, ie. at skb->end.
141 struct skb_shared_info
{
143 unsigned short nr_frags
;
144 unsigned short gso_size
;
145 /* Warning: this field is not always filled in (UFO)! */
146 unsigned short gso_segs
;
147 unsigned short gso_type
;
149 #ifdef CONFIG_HAS_DMA
150 unsigned int num_dma_maps
;
152 struct sk_buff
*frag_list
;
153 skb_frag_t frags
[MAX_SKB_FRAGS
];
154 #ifdef CONFIG_HAS_DMA
155 dma_addr_t dma_maps
[MAX_SKB_FRAGS
+ 1];
159 /* We divide dataref into two halves. The higher 16 bits hold references
160 * to the payload part of skb->data. The lower 16 bits hold references to
161 * the entire skb->data. A clone of a headerless skb holds the length of
162 * the header in skb->hdr_len.
164 * All users must obey the rule that the skb->data reference count must be
165 * greater than or equal to the payload reference count.
167 * Holding a reference to the payload part means that the user does not
168 * care about modifications to the header part of skb->data.
170 #define SKB_DATAREF_SHIFT 16
171 #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1)
175 SKB_FCLONE_UNAVAILABLE
,
181 SKB_GSO_TCPV4
= 1 << 0,
182 SKB_GSO_UDP
= 1 << 1,
184 /* This indicates the skb is from an untrusted source. */
185 SKB_GSO_DODGY
= 1 << 2,
187 /* This indicates the tcp segment has CWR set. */
188 SKB_GSO_TCP_ECN
= 1 << 3,
190 SKB_GSO_TCPV6
= 1 << 4,
193 #if BITS_PER_LONG > 32
194 #define NET_SKBUFF_DATA_USES_OFFSET 1
197 #ifdef NET_SKBUFF_DATA_USES_OFFSET
198 typedef unsigned int sk_buff_data_t
;
200 typedef unsigned char *sk_buff_data_t
;
204 * struct sk_buff - socket buffer
205 * @next: Next buffer in list
206 * @prev: Previous buffer in list
207 * @sk: Socket we are owned by
208 * @tstamp: Time we arrived
209 * @dev: Device we arrived on/are leaving by
210 * @transport_header: Transport layer header
211 * @network_header: Network layer header
212 * @mac_header: Link layer header
213 * @dst: destination entry
214 * @sp: the security path, used for xfrm
215 * @cb: Control buffer. Free for use by every layer. Put private vars here
216 * @len: Length of actual data
217 * @data_len: Data length
218 * @mac_len: Length of link layer header
219 * @hdr_len: writable header length of cloned skb
220 * @csum: Checksum (must include start/offset pair)
221 * @csum_start: Offset from skb->head where checksumming should start
222 * @csum_offset: Offset from csum_start where checksum should be stored
223 * @local_df: allow local fragmentation
224 * @cloned: Head may be cloned (check refcnt to be sure)
225 * @nohdr: Payload reference only, must not modify header
226 * @pkt_type: Packet class
227 * @fclone: skbuff clone status
228 * @ip_summed: Driver fed us an IP checksum
229 * @priority: Packet queueing priority
230 * @users: User count - see {datagram,tcp}.c
231 * @protocol: Packet protocol from driver
232 * @truesize: Buffer size
233 * @head: Head of buffer
234 * @data: Data head pointer
235 * @tail: Tail pointer
237 * @destructor: Destruct function
238 * @mark: Generic packet mark
239 * @nfct: Associated connection, if any
240 * @ipvs_property: skbuff is owned by ipvs
241 * @peeked: this packet has been seen already, so stats have been
242 * done for it, don't do them again
243 * @nf_trace: netfilter packet trace flag
244 * @nfctinfo: Relationship of this skb to the connection
245 * @nfct_reasm: netfilter conntrack re-assembly pointer
246 * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c
247 * @iif: ifindex of device we arrived on
248 * @queue_mapping: Queue mapping for multiqueue devices
249 * @tc_index: Traffic control index
250 * @tc_verd: traffic control verdict
251 * @ndisc_nodetype: router type (from link layer)
252 * @do_not_encrypt: set to prevent encryption of this frame
253 * @requeue: set to indicate that the wireless core should attempt
254 * a software retry on this frame if we failed to
255 * receive an ACK for it
256 * @dma_cookie: a cookie to one of several possible DMA operations
257 * done by skb DMA functions
258 * @secmark: security marking
259 * @vlan_tci: vlan tag control information
263 /* These two members must be first. */
264 struct sk_buff
*next
;
265 struct sk_buff
*prev
;
269 struct net_device
*dev
;
272 struct dst_entry
*dst
;
273 struct rtable
*rtable
;
279 * This is the control buffer. It is free to use for every
280 * layer. Please put your private variables there. If you
281 * want to keep them across layers you have to do a skb_clone()
282 * first. This is owned by whoever has the skb queued ATM.
310 void (*destructor
)(struct sk_buff
*skb
);
311 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
312 struct nf_conntrack
*nfct
;
313 struct sk_buff
*nfct_reasm
;
315 #ifdef CONFIG_BRIDGE_NETFILTER
316 struct nf_bridge_info
*nf_bridge
;
321 #ifdef CONFIG_NET_SCHED
322 __u16 tc_index
; /* traffic control index */
323 #ifdef CONFIG_NET_CLS_ACT
324 __u16 tc_verd
; /* traffic control verdict */
327 #ifdef CONFIG_IPV6_NDISC_NODETYPE
328 __u8 ndisc_nodetype
:2;
330 #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
331 __u8 do_not_encrypt
:1;
334 /* 0/13/14 bit hole */
336 #ifdef CONFIG_NET_DMA
337 dma_cookie_t dma_cookie
;
339 #ifdef CONFIG_NETWORK_SECMARK
347 sk_buff_data_t transport_header
;
348 sk_buff_data_t network_header
;
349 sk_buff_data_t mac_header
;
350 /* These elements must be at the end, see alloc_skb() for details. */
355 unsigned int truesize
;
361 * Handling routines are only of interest to the kernel
363 #include <linux/slab.h>
365 #include <asm/system.h>
367 #ifdef CONFIG_HAS_DMA
368 #include <linux/dma-mapping.h>
369 extern int skb_dma_map(struct device
*dev
, struct sk_buff
*skb
,
370 enum dma_data_direction dir
);
371 extern void skb_dma_unmap(struct device
*dev
, struct sk_buff
*skb
,
372 enum dma_data_direction dir
);
375 extern void kfree_skb(struct sk_buff
*skb
);
376 extern void __kfree_skb(struct sk_buff
*skb
);
377 extern struct sk_buff
*__alloc_skb(unsigned int size
,
378 gfp_t priority
, int fclone
, int node
);
379 static inline struct sk_buff
*alloc_skb(unsigned int size
,
382 return __alloc_skb(size
, priority
, 0, -1);
385 static inline struct sk_buff
*alloc_skb_fclone(unsigned int size
,
388 return __alloc_skb(size
, priority
, 1, -1);
391 extern int skb_recycle_check(struct sk_buff
*skb
, int skb_size
);
393 extern struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
);
394 extern struct sk_buff
*skb_clone(struct sk_buff
*skb
,
396 extern struct sk_buff
*skb_copy(const struct sk_buff
*skb
,
398 extern struct sk_buff
*pskb_copy(struct sk_buff
*skb
,
400 extern int pskb_expand_head(struct sk_buff
*skb
,
401 int nhead
, int ntail
,
403 extern struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
,
404 unsigned int headroom
);
405 extern struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
406 int newheadroom
, int newtailroom
,
408 extern int skb_to_sgvec(struct sk_buff
*skb
,
409 struct scatterlist
*sg
, int offset
,
411 extern int skb_cow_data(struct sk_buff
*skb
, int tailbits
,
412 struct sk_buff
**trailer
);
413 extern int skb_pad(struct sk_buff
*skb
, int pad
);
414 #define dev_kfree_skb(a) kfree_skb(a)
415 extern void skb_over_panic(struct sk_buff
*skb
, int len
,
417 extern void skb_under_panic(struct sk_buff
*skb
, int len
,
419 extern void skb_truesize_bug(struct sk_buff
*skb
);
421 static inline void skb_truesize_check(struct sk_buff
*skb
)
423 int len
= sizeof(struct sk_buff
) + skb
->len
;
425 if (unlikely((int)skb
->truesize
< len
))
426 skb_truesize_bug(skb
);
429 extern int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
430 int getfrag(void *from
, char *to
, int offset
,
431 int len
,int odd
, struct sk_buff
*skb
),
432 void *from
, int length
);
439 __u32 stepped_offset
;
440 struct sk_buff
*root_skb
;
441 struct sk_buff
*cur_skb
;
445 extern void skb_prepare_seq_read(struct sk_buff
*skb
,
446 unsigned int from
, unsigned int to
,
447 struct skb_seq_state
*st
);
448 extern unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
449 struct skb_seq_state
*st
);
450 extern void skb_abort_seq_read(struct skb_seq_state
*st
);
452 extern unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
453 unsigned int to
, struct ts_config
*config
,
454 struct ts_state
*state
);
456 #ifdef NET_SKBUFF_DATA_USES_OFFSET
457 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
459 return skb
->head
+ skb
->end
;
462 static inline unsigned char *skb_end_pointer(const struct sk_buff
*skb
)
469 #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB)))
472 * skb_queue_empty - check if a queue is empty
475 * Returns true if the queue is empty, false otherwise.
477 static inline int skb_queue_empty(const struct sk_buff_head
*list
)
479 return list
->next
== (struct sk_buff
*)list
;
483 * skb_queue_is_last - check if skb is the last entry in the queue
487 * Returns true if @skb is the last buffer on the list.
489 static inline bool skb_queue_is_last(const struct sk_buff_head
*list
,
490 const struct sk_buff
*skb
)
492 return (skb
->next
== (struct sk_buff
*) list
);
496 * skb_queue_is_first - check if skb is the first entry in the queue
500 * Returns true if @skb is the first buffer on the list.
502 static inline bool skb_queue_is_first(const struct sk_buff_head
*list
,
503 const struct sk_buff
*skb
)
505 return (skb
->prev
== (struct sk_buff
*) list
);
509 * skb_queue_next - return the next packet in the queue
511 * @skb: current buffer
513 * Return the next packet in @list after @skb. It is only valid to
514 * call this if skb_queue_is_last() evaluates to false.
516 static inline struct sk_buff
*skb_queue_next(const struct sk_buff_head
*list
,
517 const struct sk_buff
*skb
)
519 /* This BUG_ON may seem severe, but if we just return then we
520 * are going to dereference garbage.
522 BUG_ON(skb_queue_is_last(list
, skb
));
527 * skb_queue_prev - return the prev packet in the queue
529 * @skb: current buffer
531 * Return the prev packet in @list before @skb. It is only valid to
532 * call this if skb_queue_is_first() evaluates to false.
534 static inline struct sk_buff
*skb_queue_prev(const struct sk_buff_head
*list
,
535 const struct sk_buff
*skb
)
537 /* This BUG_ON may seem severe, but if we just return then we
538 * are going to dereference garbage.
540 BUG_ON(skb_queue_is_first(list
, skb
));
545 * skb_get - reference buffer
546 * @skb: buffer to reference
548 * Makes another reference to a socket buffer and returns a pointer
551 static inline struct sk_buff
*skb_get(struct sk_buff
*skb
)
553 atomic_inc(&skb
->users
);
558 * If users == 1, we are the only owner and are can avoid redundant
563 * skb_cloned - is the buffer a clone
564 * @skb: buffer to check
566 * Returns true if the buffer was generated with skb_clone() and is
567 * one of multiple shared copies of the buffer. Cloned buffers are
568 * shared data so must not be written to under normal circumstances.
570 static inline int skb_cloned(const struct sk_buff
*skb
)
572 return skb
->cloned
&&
573 (atomic_read(&skb_shinfo(skb
)->dataref
) & SKB_DATAREF_MASK
) != 1;
577 * skb_header_cloned - is the header a clone
578 * @skb: buffer to check
580 * Returns true if modifying the header part of the buffer requires
581 * the data to be copied.
583 static inline int skb_header_cloned(const struct sk_buff
*skb
)
590 dataref
= atomic_read(&skb_shinfo(skb
)->dataref
);
591 dataref
= (dataref
& SKB_DATAREF_MASK
) - (dataref
>> SKB_DATAREF_SHIFT
);
596 * skb_header_release - release reference to header
597 * @skb: buffer to operate on
599 * Drop a reference to the header part of the buffer. This is done
600 * by acquiring a payload reference. You must not read from the header
601 * part of skb->data after this.
603 static inline void skb_header_release(struct sk_buff
*skb
)
607 atomic_add(1 << SKB_DATAREF_SHIFT
, &skb_shinfo(skb
)->dataref
);
611 * skb_shared - is the buffer shared
612 * @skb: buffer to check
614 * Returns true if more than one person has a reference to this
617 static inline int skb_shared(const struct sk_buff
*skb
)
619 return atomic_read(&skb
->users
) != 1;
623 * skb_share_check - check if buffer is shared and if so clone it
624 * @skb: buffer to check
625 * @pri: priority for memory allocation
627 * If the buffer is shared the buffer is cloned and the old copy
628 * drops a reference. A new clone with a single reference is returned.
629 * If the buffer is not shared the original buffer is returned. When
630 * being called from interrupt status or with spinlocks held pri must
633 * NULL is returned on a memory allocation failure.
635 static inline struct sk_buff
*skb_share_check(struct sk_buff
*skb
,
638 might_sleep_if(pri
& __GFP_WAIT
);
639 if (skb_shared(skb
)) {
640 struct sk_buff
*nskb
= skb_clone(skb
, pri
);
648 * Copy shared buffers into a new sk_buff. We effectively do COW on
649 * packets to handle cases where we have a local reader and forward
650 * and a couple of other messy ones. The normal one is tcpdumping
651 * a packet thats being forwarded.
655 * skb_unshare - make a copy of a shared buffer
656 * @skb: buffer to check
657 * @pri: priority for memory allocation
659 * If the socket buffer is a clone then this function creates a new
660 * copy of the data, drops a reference count on the old copy and returns
661 * the new copy with the reference count at 1. If the buffer is not a clone
662 * the original buffer is returned. When called with a spinlock held or
663 * from interrupt state @pri must be %GFP_ATOMIC
665 * %NULL is returned on a memory allocation failure.
667 static inline struct sk_buff
*skb_unshare(struct sk_buff
*skb
,
670 might_sleep_if(pri
& __GFP_WAIT
);
671 if (skb_cloned(skb
)) {
672 struct sk_buff
*nskb
= skb_copy(skb
, pri
);
673 kfree_skb(skb
); /* Free our shared copy */
681 * @list_: list to peek at
683 * Peek an &sk_buff. Unlike most other operations you _MUST_
684 * be careful with this one. A peek leaves the buffer on the
685 * list and someone else may run off with it. You must hold
686 * the appropriate locks or have a private queue to do this.
688 * Returns %NULL for an empty list or a pointer to the head element.
689 * The reference count is not incremented and the reference is therefore
690 * volatile. Use with caution.
692 static inline struct sk_buff
*skb_peek(struct sk_buff_head
*list_
)
694 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->next
;
695 if (list
== (struct sk_buff
*)list_
)
702 * @list_: list to peek at
704 * Peek an &sk_buff. Unlike most other operations you _MUST_
705 * be careful with this one. A peek leaves the buffer on the
706 * list and someone else may run off with it. You must hold
707 * the appropriate locks or have a private queue to do this.
709 * Returns %NULL for an empty list or a pointer to the tail element.
710 * The reference count is not incremented and the reference is therefore
711 * volatile. Use with caution.
713 static inline struct sk_buff
*skb_peek_tail(struct sk_buff_head
*list_
)
715 struct sk_buff
*list
= ((struct sk_buff
*)list_
)->prev
;
716 if (list
== (struct sk_buff
*)list_
)
722 * skb_queue_len - get queue length
723 * @list_: list to measure
725 * Return the length of an &sk_buff queue.
727 static inline __u32
skb_queue_len(const struct sk_buff_head
*list_
)
733 * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head
734 * @list: queue to initialize
736 * This initializes only the list and queue length aspects of
737 * an sk_buff_head object. This allows to initialize the list
738 * aspects of an sk_buff_head without reinitializing things like
739 * the spinlock. It can also be used for on-stack sk_buff_head
740 * objects where the spinlock is known to not be used.
742 static inline void __skb_queue_head_init(struct sk_buff_head
*list
)
744 list
->prev
= list
->next
= (struct sk_buff
*)list
;
749 * This function creates a split out lock class for each invocation;
750 * this is needed for now since a whole lot of users of the skb-queue
751 * infrastructure in drivers have different locking usage (in hardirq)
752 * than the networking core (in softirq only). In the long run either the
753 * network layer or drivers should need annotation to consolidate the
754 * main types of usage into 3 classes.
756 static inline void skb_queue_head_init(struct sk_buff_head
*list
)
758 spin_lock_init(&list
->lock
);
759 __skb_queue_head_init(list
);
762 static inline void skb_queue_head_init_class(struct sk_buff_head
*list
,
763 struct lock_class_key
*class)
765 skb_queue_head_init(list
);
766 lockdep_set_class(&list
->lock
, class);
770 * Insert an sk_buff on a list.
772 * The "__skb_xxxx()" functions are the non-atomic ones that
773 * can only be called with interrupts disabled.
775 extern void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
);
776 static inline void __skb_insert(struct sk_buff
*newsk
,
777 struct sk_buff
*prev
, struct sk_buff
*next
,
778 struct sk_buff_head
*list
)
782 next
->prev
= prev
->next
= newsk
;
786 static inline void __skb_queue_splice(const struct sk_buff_head
*list
,
787 struct sk_buff
*prev
,
788 struct sk_buff
*next
)
790 struct sk_buff
*first
= list
->next
;
791 struct sk_buff
*last
= list
->prev
;
801 * skb_queue_splice - join two skb lists, this is designed for stacks
802 * @list: the new list to add
803 * @head: the place to add it in the first list
805 static inline void skb_queue_splice(const struct sk_buff_head
*list
,
806 struct sk_buff_head
*head
)
808 if (!skb_queue_empty(list
)) {
809 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
810 head
->qlen
+= list
->qlen
;
815 * skb_queue_splice - join two skb lists and reinitialise the emptied list
816 * @list: the new list to add
817 * @head: the place to add it in the first list
819 * The list at @list is reinitialised
821 static inline void skb_queue_splice_init(struct sk_buff_head
*list
,
822 struct sk_buff_head
*head
)
824 if (!skb_queue_empty(list
)) {
825 __skb_queue_splice(list
, (struct sk_buff
*) head
, head
->next
);
826 head
->qlen
+= list
->qlen
;
827 __skb_queue_head_init(list
);
832 * skb_queue_splice_tail - join two skb lists, each list being a queue
833 * @list: the new list to add
834 * @head: the place to add it in the first list
836 static inline void skb_queue_splice_tail(const struct sk_buff_head
*list
,
837 struct sk_buff_head
*head
)
839 if (!skb_queue_empty(list
)) {
840 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
841 head
->qlen
+= list
->qlen
;
846 * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list
847 * @list: the new list to add
848 * @head: the place to add it in the first list
850 * Each of the lists is a queue.
851 * The list at @list is reinitialised
853 static inline void skb_queue_splice_tail_init(struct sk_buff_head
*list
,
854 struct sk_buff_head
*head
)
856 if (!skb_queue_empty(list
)) {
857 __skb_queue_splice(list
, head
->prev
, (struct sk_buff
*) head
);
858 head
->qlen
+= list
->qlen
;
859 __skb_queue_head_init(list
);
864 * __skb_queue_after - queue a buffer at the list head
866 * @prev: place after this buffer
867 * @newsk: buffer to queue
869 * Queue a buffer int the middle of a list. This function takes no locks
870 * and you must therefore hold required locks before calling it.
872 * A buffer cannot be placed on two lists at the same time.
874 static inline void __skb_queue_after(struct sk_buff_head
*list
,
875 struct sk_buff
*prev
,
876 struct sk_buff
*newsk
)
878 __skb_insert(newsk
, prev
, prev
->next
, list
);
881 extern void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
,
882 struct sk_buff_head
*list
);
884 static inline void __skb_queue_before(struct sk_buff_head
*list
,
885 struct sk_buff
*next
,
886 struct sk_buff
*newsk
)
888 __skb_insert(newsk
, next
->prev
, next
, list
);
892 * __skb_queue_head - queue a buffer at the list head
894 * @newsk: buffer to queue
896 * Queue a buffer at the start of a list. This function takes no locks
897 * and you must therefore hold required locks before calling it.
899 * A buffer cannot be placed on two lists at the same time.
901 extern void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
902 static inline void __skb_queue_head(struct sk_buff_head
*list
,
903 struct sk_buff
*newsk
)
905 __skb_queue_after(list
, (struct sk_buff
*)list
, newsk
);
909 * __skb_queue_tail - queue a buffer at the list tail
911 * @newsk: buffer to queue
913 * Queue a buffer at the end of a list. This function takes no locks
914 * and you must therefore hold required locks before calling it.
916 * A buffer cannot be placed on two lists at the same time.
918 extern void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
);
919 static inline void __skb_queue_tail(struct sk_buff_head
*list
,
920 struct sk_buff
*newsk
)
922 __skb_queue_before(list
, (struct sk_buff
*)list
, newsk
);
926 * remove sk_buff from list. _Must_ be called atomically, and with
929 extern void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
);
930 static inline void __skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
932 struct sk_buff
*next
, *prev
;
937 skb
->next
= skb
->prev
= NULL
;
943 * __skb_dequeue - remove from the head of the queue
944 * @list: list to dequeue from
946 * Remove the head of the list. This function does not take any locks
947 * so must be used with appropriate locks held only. The head item is
948 * returned or %NULL if the list is empty.
950 extern struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
);
951 static inline struct sk_buff
*__skb_dequeue(struct sk_buff_head
*list
)
953 struct sk_buff
*skb
= skb_peek(list
);
955 __skb_unlink(skb
, list
);
960 * __skb_dequeue_tail - remove from the tail of the queue
961 * @list: list to dequeue from
963 * Remove the tail of the list. This function does not take any locks
964 * so must be used with appropriate locks held only. The tail item is
965 * returned or %NULL if the list is empty.
967 extern struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
);
968 static inline struct sk_buff
*__skb_dequeue_tail(struct sk_buff_head
*list
)
970 struct sk_buff
*skb
= skb_peek_tail(list
);
972 __skb_unlink(skb
, list
);
977 static inline int skb_is_nonlinear(const struct sk_buff
*skb
)
979 return skb
->data_len
;
982 static inline unsigned int skb_headlen(const struct sk_buff
*skb
)
984 return skb
->len
- skb
->data_len
;
987 static inline int skb_pagelen(const struct sk_buff
*skb
)
991 for (i
= (int)skb_shinfo(skb
)->nr_frags
- 1; i
>= 0; i
--)
992 len
+= skb_shinfo(skb
)->frags
[i
].size
;
993 return len
+ skb_headlen(skb
);
996 static inline void skb_fill_page_desc(struct sk_buff
*skb
, int i
,
997 struct page
*page
, int off
, int size
)
999 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1002 frag
->page_offset
= off
;
1004 skb_shinfo(skb
)->nr_frags
= i
+ 1;
1007 extern void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
,
1010 #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags)
1011 #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list)
1012 #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb))
1014 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1015 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1017 return skb
->head
+ skb
->tail
;
1020 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1022 skb
->tail
= skb
->data
- skb
->head
;
1025 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1027 skb_reset_tail_pointer(skb
);
1028 skb
->tail
+= offset
;
1030 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1031 static inline unsigned char *skb_tail_pointer(const struct sk_buff
*skb
)
1036 static inline void skb_reset_tail_pointer(struct sk_buff
*skb
)
1038 skb
->tail
= skb
->data
;
1041 static inline void skb_set_tail_pointer(struct sk_buff
*skb
, const int offset
)
1043 skb
->tail
= skb
->data
+ offset
;
1046 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1049 * Add data to an sk_buff
1051 extern unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
);
1052 static inline unsigned char *__skb_put(struct sk_buff
*skb
, unsigned int len
)
1054 unsigned char *tmp
= skb_tail_pointer(skb
);
1055 SKB_LINEAR_ASSERT(skb
);
1061 extern unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
);
1062 static inline unsigned char *__skb_push(struct sk_buff
*skb
, unsigned int len
)
1069 extern unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
);
1070 static inline unsigned char *__skb_pull(struct sk_buff
*skb
, unsigned int len
)
1073 BUG_ON(skb
->len
< skb
->data_len
);
1074 return skb
->data
+= len
;
1077 extern unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
);
1079 static inline unsigned char *__pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1081 if (len
> skb_headlen(skb
) &&
1082 !__pskb_pull_tail(skb
, len
- skb_headlen(skb
)))
1085 return skb
->data
+= len
;
1088 static inline unsigned char *pskb_pull(struct sk_buff
*skb
, unsigned int len
)
1090 return unlikely(len
> skb
->len
) ? NULL
: __pskb_pull(skb
, len
);
1093 static inline int pskb_may_pull(struct sk_buff
*skb
, unsigned int len
)
1095 if (likely(len
<= skb_headlen(skb
)))
1097 if (unlikely(len
> skb
->len
))
1099 return __pskb_pull_tail(skb
, len
- skb_headlen(skb
)) != NULL
;
1103 * skb_headroom - bytes at buffer head
1104 * @skb: buffer to check
1106 * Return the number of bytes of free space at the head of an &sk_buff.
1108 static inline unsigned int skb_headroom(const struct sk_buff
*skb
)
1110 return skb
->data
- skb
->head
;
1114 * skb_tailroom - bytes at buffer end
1115 * @skb: buffer to check
1117 * Return the number of bytes of free space at the tail of an sk_buff
1119 static inline int skb_tailroom(const struct sk_buff
*skb
)
1121 return skb_is_nonlinear(skb
) ? 0 : skb
->end
- skb
->tail
;
1125 * skb_reserve - adjust headroom
1126 * @skb: buffer to alter
1127 * @len: bytes to move
1129 * Increase the headroom of an empty &sk_buff by reducing the tail
1130 * room. This is only allowed for an empty buffer.
1132 static inline void skb_reserve(struct sk_buff
*skb
, int len
)
1138 #ifdef NET_SKBUFF_DATA_USES_OFFSET
1139 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1141 return skb
->head
+ skb
->transport_header
;
1144 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1146 skb
->transport_header
= skb
->data
- skb
->head
;
1149 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1152 skb_reset_transport_header(skb
);
1153 skb
->transport_header
+= offset
;
1156 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1158 return skb
->head
+ skb
->network_header
;
1161 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1163 skb
->network_header
= skb
->data
- skb
->head
;
1166 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1168 skb_reset_network_header(skb
);
1169 skb
->network_header
+= offset
;
1172 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1174 return skb
->head
+ skb
->mac_header
;
1177 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1179 return skb
->mac_header
!= ~0U;
1182 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1184 skb
->mac_header
= skb
->data
- skb
->head
;
1187 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1189 skb_reset_mac_header(skb
);
1190 skb
->mac_header
+= offset
;
1193 #else /* NET_SKBUFF_DATA_USES_OFFSET */
1195 static inline unsigned char *skb_transport_header(const struct sk_buff
*skb
)
1197 return skb
->transport_header
;
1200 static inline void skb_reset_transport_header(struct sk_buff
*skb
)
1202 skb
->transport_header
= skb
->data
;
1205 static inline void skb_set_transport_header(struct sk_buff
*skb
,
1208 skb
->transport_header
= skb
->data
+ offset
;
1211 static inline unsigned char *skb_network_header(const struct sk_buff
*skb
)
1213 return skb
->network_header
;
1216 static inline void skb_reset_network_header(struct sk_buff
*skb
)
1218 skb
->network_header
= skb
->data
;
1221 static inline void skb_set_network_header(struct sk_buff
*skb
, const int offset
)
1223 skb
->network_header
= skb
->data
+ offset
;
1226 static inline unsigned char *skb_mac_header(const struct sk_buff
*skb
)
1228 return skb
->mac_header
;
1231 static inline int skb_mac_header_was_set(const struct sk_buff
*skb
)
1233 return skb
->mac_header
!= NULL
;
1236 static inline void skb_reset_mac_header(struct sk_buff
*skb
)
1238 skb
->mac_header
= skb
->data
;
1241 static inline void skb_set_mac_header(struct sk_buff
*skb
, const int offset
)
1243 skb
->mac_header
= skb
->data
+ offset
;
1245 #endif /* NET_SKBUFF_DATA_USES_OFFSET */
1247 static inline int skb_transport_offset(const struct sk_buff
*skb
)
1249 return skb_transport_header(skb
) - skb
->data
;
1252 static inline u32
skb_network_header_len(const struct sk_buff
*skb
)
1254 return skb
->transport_header
- skb
->network_header
;
1257 static inline int skb_network_offset(const struct sk_buff
*skb
)
1259 return skb_network_header(skb
) - skb
->data
;
1263 * CPUs often take a performance hit when accessing unaligned memory
1264 * locations. The actual performance hit varies, it can be small if the
1265 * hardware handles it or large if we have to take an exception and fix it
1268 * Since an ethernet header is 14 bytes network drivers often end up with
1269 * the IP header at an unaligned offset. The IP header can be aligned by
1270 * shifting the start of the packet by 2 bytes. Drivers should do this
1273 * skb_reserve(NET_IP_ALIGN);
1275 * The downside to this alignment of the IP header is that the DMA is now
1276 * unaligned. On some architectures the cost of an unaligned DMA is high
1277 * and this cost outweighs the gains made by aligning the IP header.
1279 * Since this trade off varies between architectures, we allow NET_IP_ALIGN
1282 #ifndef NET_IP_ALIGN
1283 #define NET_IP_ALIGN 2
1287 * The networking layer reserves some headroom in skb data (via
1288 * dev_alloc_skb). This is used to avoid having to reallocate skb data when
1289 * the header has to grow. In the default case, if the header has to grow
1290 * 16 bytes or less we avoid the reallocation.
1292 * Unfortunately this headroom changes the DMA alignment of the resulting
1293 * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
1294 * on some architectures. An architecture can override this value,
1295 * perhaps setting it to a cacheline in size (since that will maintain
1296 * cacheline alignment of the DMA). It must be a power of 2.
1298 * Various parts of the networking layer expect at least 16 bytes of
1299 * headroom, you should not reduce this.
1302 #define NET_SKB_PAD 16
1305 extern int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
);
1307 static inline void __skb_trim(struct sk_buff
*skb
, unsigned int len
)
1309 if (unlikely(skb
->data_len
)) {
1314 skb_set_tail_pointer(skb
, len
);
1317 extern void skb_trim(struct sk_buff
*skb
, unsigned int len
);
1319 static inline int __pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1322 return ___pskb_trim(skb
, len
);
1323 __skb_trim(skb
, len
);
1327 static inline int pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1329 return (len
< skb
->len
) ? __pskb_trim(skb
, len
) : 0;
1333 * pskb_trim_unique - remove end from a paged unique (not cloned) buffer
1334 * @skb: buffer to alter
1337 * This is identical to pskb_trim except that the caller knows that
1338 * the skb is not cloned so we should never get an error due to out-
1341 static inline void pskb_trim_unique(struct sk_buff
*skb
, unsigned int len
)
1343 int err
= pskb_trim(skb
, len
);
1348 * skb_orphan - orphan a buffer
1349 * @skb: buffer to orphan
1351 * If a buffer currently has an owner then we call the owner's
1352 * destructor function and make the @skb unowned. The buffer continues
1353 * to exist but is no longer charged to its former owner.
1355 static inline void skb_orphan(struct sk_buff
*skb
)
1357 if (skb
->destructor
)
1358 skb
->destructor(skb
);
1359 skb
->destructor
= NULL
;
1364 * __skb_queue_purge - empty a list
1365 * @list: list to empty
1367 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1368 * the list and one reference dropped. This function does not take the
1369 * list lock and the caller must hold the relevant locks to use it.
1371 extern void skb_queue_purge(struct sk_buff_head
*list
);
1372 static inline void __skb_queue_purge(struct sk_buff_head
*list
)
1374 struct sk_buff
*skb
;
1375 while ((skb
= __skb_dequeue(list
)) != NULL
)
1380 * __dev_alloc_skb - allocate an skbuff for receiving
1381 * @length: length to allocate
1382 * @gfp_mask: get_free_pages mask, passed to alloc_skb
1384 * Allocate a new &sk_buff and assign it a usage count of one. The
1385 * buffer has unspecified headroom built in. Users should allocate
1386 * the headroom they think they need without accounting for the
1387 * built in space. The built in space is used for optimisations.
1389 * %NULL is returned if there is no free memory.
1391 static inline struct sk_buff
*__dev_alloc_skb(unsigned int length
,
1394 struct sk_buff
*skb
= alloc_skb(length
+ NET_SKB_PAD
, gfp_mask
);
1396 skb_reserve(skb
, NET_SKB_PAD
);
1400 extern struct sk_buff
*dev_alloc_skb(unsigned int length
);
1402 extern struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
1403 unsigned int length
, gfp_t gfp_mask
);
1406 * netdev_alloc_skb - allocate an skbuff for rx on a specific device
1407 * @dev: network device to receive on
1408 * @length: length to allocate
1410 * Allocate a new &sk_buff and assign it a usage count of one. The
1411 * buffer has unspecified headroom built in. Users should allocate
1412 * the headroom they think they need without accounting for the
1413 * built in space. The built in space is used for optimisations.
1415 * %NULL is returned if there is no free memory. Although this function
1416 * allocates memory it can be called from an interrupt.
1418 static inline struct sk_buff
*netdev_alloc_skb(struct net_device
*dev
,
1419 unsigned int length
)
1421 return __netdev_alloc_skb(dev
, length
, GFP_ATOMIC
);
1424 extern struct page
*__netdev_alloc_page(struct net_device
*dev
, gfp_t gfp_mask
);
1427 * netdev_alloc_page - allocate a page for ps-rx on a specific device
1428 * @dev: network device to receive on
1430 * Allocate a new page node local to the specified device.
1432 * %NULL is returned if there is no free memory.
1434 static inline struct page
*netdev_alloc_page(struct net_device
*dev
)
1436 return __netdev_alloc_page(dev
, GFP_ATOMIC
);
1439 static inline void netdev_free_page(struct net_device
*dev
, struct page
*page
)
1445 * skb_clone_writable - is the header of a clone writable
1446 * @skb: buffer to check
1447 * @len: length up to which to write
1449 * Returns true if modifying the header part of the cloned buffer
1450 * does not requires the data to be copied.
1452 static inline int skb_clone_writable(struct sk_buff
*skb
, unsigned int len
)
1454 return !skb_header_cloned(skb
) &&
1455 skb_headroom(skb
) + len
<= skb
->hdr_len
;
1458 static inline int __skb_cow(struct sk_buff
*skb
, unsigned int headroom
,
1463 if (headroom
< NET_SKB_PAD
)
1464 headroom
= NET_SKB_PAD
;
1465 if (headroom
> skb_headroom(skb
))
1466 delta
= headroom
- skb_headroom(skb
);
1468 if (delta
|| cloned
)
1469 return pskb_expand_head(skb
, ALIGN(delta
, NET_SKB_PAD
), 0,
1475 * skb_cow - copy header of skb when it is required
1476 * @skb: buffer to cow
1477 * @headroom: needed headroom
1479 * If the skb passed lacks sufficient headroom or its data part
1480 * is shared, data is reallocated. If reallocation fails, an error
1481 * is returned and original skb is not changed.
1483 * The result is skb with writable area skb->head...skb->tail
1484 * and at least @headroom of space at head.
1486 static inline int skb_cow(struct sk_buff
*skb
, unsigned int headroom
)
1488 return __skb_cow(skb
, headroom
, skb_cloned(skb
));
1492 * skb_cow_head - skb_cow but only making the head writable
1493 * @skb: buffer to cow
1494 * @headroom: needed headroom
1496 * This function is identical to skb_cow except that we replace the
1497 * skb_cloned check by skb_header_cloned. It should be used when
1498 * you only need to push on some header and do not need to modify
1501 static inline int skb_cow_head(struct sk_buff
*skb
, unsigned int headroom
)
1503 return __skb_cow(skb
, headroom
, skb_header_cloned(skb
));
1507 * skb_padto - pad an skbuff up to a minimal size
1508 * @skb: buffer to pad
1509 * @len: minimal length
1511 * Pads up a buffer to ensure the trailing bytes exist and are
1512 * blanked. If the buffer already contains sufficient data it
1513 * is untouched. Otherwise it is extended. Returns zero on
1514 * success. The skb is freed on error.
1517 static inline int skb_padto(struct sk_buff
*skb
, unsigned int len
)
1519 unsigned int size
= skb
->len
;
1520 if (likely(size
>= len
))
1522 return skb_pad(skb
, len
- size
);
1525 static inline int skb_add_data(struct sk_buff
*skb
,
1526 char __user
*from
, int copy
)
1528 const int off
= skb
->len
;
1530 if (skb
->ip_summed
== CHECKSUM_NONE
) {
1532 __wsum csum
= csum_and_copy_from_user(from
, skb_put(skb
, copy
),
1535 skb
->csum
= csum_block_add(skb
->csum
, csum
, off
);
1538 } else if (!copy_from_user(skb_put(skb
, copy
), from
, copy
))
1541 __skb_trim(skb
, off
);
1545 static inline int skb_can_coalesce(struct sk_buff
*skb
, int i
,
1546 struct page
*page
, int off
)
1549 struct skb_frag_struct
*frag
= &skb_shinfo(skb
)->frags
[i
- 1];
1551 return page
== frag
->page
&&
1552 off
== frag
->page_offset
+ frag
->size
;
1557 static inline int __skb_linearize(struct sk_buff
*skb
)
1559 return __pskb_pull_tail(skb
, skb
->data_len
) ? 0 : -ENOMEM
;
1563 * skb_linearize - convert paged skb to linear one
1564 * @skb: buffer to linarize
1566 * If there is no free memory -ENOMEM is returned, otherwise zero
1567 * is returned and the old skb data released.
1569 static inline int skb_linearize(struct sk_buff
*skb
)
1571 return skb_is_nonlinear(skb
) ? __skb_linearize(skb
) : 0;
1575 * skb_linearize_cow - make sure skb is linear and writable
1576 * @skb: buffer to process
1578 * If there is no free memory -ENOMEM is returned, otherwise zero
1579 * is returned and the old skb data released.
1581 static inline int skb_linearize_cow(struct sk_buff
*skb
)
1583 return skb_is_nonlinear(skb
) || skb_cloned(skb
) ?
1584 __skb_linearize(skb
) : 0;
1588 * skb_postpull_rcsum - update checksum for received skb after pull
1589 * @skb: buffer to update
1590 * @start: start of data before pull
1591 * @len: length of data pulled
1593 * After doing a pull on a received packet, you need to call this to
1594 * update the CHECKSUM_COMPLETE checksum, or set ip_summed to
1595 * CHECKSUM_NONE so that it can be recomputed from scratch.
1598 static inline void skb_postpull_rcsum(struct sk_buff
*skb
,
1599 const void *start
, unsigned int len
)
1601 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1602 skb
->csum
= csum_sub(skb
->csum
, csum_partial(start
, len
, 0));
1605 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
);
1608 * pskb_trim_rcsum - trim received skb and update checksum
1609 * @skb: buffer to trim
1612 * This is exactly the same as pskb_trim except that it ensures the
1613 * checksum of received packets are still valid after the operation.
1616 static inline int pskb_trim_rcsum(struct sk_buff
*skb
, unsigned int len
)
1618 if (likely(len
>= skb
->len
))
1620 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1621 skb
->ip_summed
= CHECKSUM_NONE
;
1622 return __pskb_trim(skb
, len
);
1625 #define skb_queue_walk(queue, skb) \
1626 for (skb = (queue)->next; \
1627 prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1630 #define skb_queue_walk_safe(queue, skb, tmp) \
1631 for (skb = (queue)->next, tmp = skb->next; \
1632 skb != (struct sk_buff *)(queue); \
1633 skb = tmp, tmp = skb->next)
1635 #define skb_queue_walk_from(queue, skb) \
1636 for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \
1639 #define skb_queue_walk_from_safe(queue, skb, tmp) \
1640 for (tmp = skb->next; \
1641 skb != (struct sk_buff *)(queue); \
1642 skb = tmp, tmp = skb->next)
1644 #define skb_queue_reverse_walk(queue, skb) \
1645 for (skb = (queue)->prev; \
1646 prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \
1650 extern struct sk_buff
*__skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1651 int *peeked
, int *err
);
1652 extern struct sk_buff
*skb_recv_datagram(struct sock
*sk
, unsigned flags
,
1653 int noblock
, int *err
);
1654 extern unsigned int datagram_poll(struct file
*file
, struct socket
*sock
,
1655 struct poll_table_struct
*wait
);
1656 extern int skb_copy_datagram_iovec(const struct sk_buff
*from
,
1657 int offset
, struct iovec
*to
,
1659 extern int skb_copy_and_csum_datagram_iovec(struct sk_buff
*skb
,
1662 extern int skb_copy_datagram_from_iovec(struct sk_buff
*skb
,
1666 extern void skb_free_datagram(struct sock
*sk
, struct sk_buff
*skb
);
1667 extern int skb_kill_datagram(struct sock
*sk
, struct sk_buff
*skb
,
1668 unsigned int flags
);
1669 extern __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
1670 int len
, __wsum csum
);
1671 extern int skb_copy_bits(const struct sk_buff
*skb
, int offset
,
1673 extern int skb_store_bits(struct sk_buff
*skb
, int offset
,
1674 const void *from
, int len
);
1675 extern __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
,
1676 int offset
, u8
*to
, int len
,
1678 extern int skb_splice_bits(struct sk_buff
*skb
,
1679 unsigned int offset
,
1680 struct pipe_inode_info
*pipe
,
1682 unsigned int flags
);
1683 extern void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
);
1684 extern void skb_split(struct sk_buff
*skb
,
1685 struct sk_buff
*skb1
, const u32 len
);
1686 extern int skb_shift(struct sk_buff
*tgt
, struct sk_buff
*skb
,
1689 extern struct sk_buff
*skb_segment(struct sk_buff
*skb
, int features
);
1691 static inline void *skb_header_pointer(const struct sk_buff
*skb
, int offset
,
1692 int len
, void *buffer
)
1694 int hlen
= skb_headlen(skb
);
1696 if (hlen
- offset
>= len
)
1697 return skb
->data
+ offset
;
1699 if (skb_copy_bits(skb
, offset
, buffer
, len
) < 0)
1705 static inline void skb_copy_from_linear_data(const struct sk_buff
*skb
,
1707 const unsigned int len
)
1709 memcpy(to
, skb
->data
, len
);
1712 static inline void skb_copy_from_linear_data_offset(const struct sk_buff
*skb
,
1713 const int offset
, void *to
,
1714 const unsigned int len
)
1716 memcpy(to
, skb
->data
+ offset
, len
);
1719 static inline void skb_copy_to_linear_data(struct sk_buff
*skb
,
1721 const unsigned int len
)
1723 memcpy(skb
->data
, from
, len
);
1726 static inline void skb_copy_to_linear_data_offset(struct sk_buff
*skb
,
1729 const unsigned int len
)
1731 memcpy(skb
->data
+ offset
, from
, len
);
1734 extern void skb_init(void);
1737 * skb_get_timestamp - get timestamp from a skb
1738 * @skb: skb to get stamp from
1739 * @stamp: pointer to struct timeval to store stamp in
1741 * Timestamps are stored in the skb as offsets to a base timestamp.
1742 * This function converts the offset back to a struct timeval and stores
1745 static inline void skb_get_timestamp(const struct sk_buff
*skb
, struct timeval
*stamp
)
1747 *stamp
= ktime_to_timeval(skb
->tstamp
);
1750 static inline void __net_timestamp(struct sk_buff
*skb
)
1752 skb
->tstamp
= ktime_get_real();
1755 static inline ktime_t
net_timedelta(ktime_t t
)
1757 return ktime_sub(ktime_get_real(), t
);
1760 static inline ktime_t
net_invalid_timestamp(void)
1762 return ktime_set(0, 0);
1765 extern __sum16
__skb_checksum_complete_head(struct sk_buff
*skb
, int len
);
1766 extern __sum16
__skb_checksum_complete(struct sk_buff
*skb
);
1768 static inline int skb_csum_unnecessary(const struct sk_buff
*skb
)
1770 return skb
->ip_summed
& CHECKSUM_UNNECESSARY
;
1774 * skb_checksum_complete - Calculate checksum of an entire packet
1775 * @skb: packet to process
1777 * This function calculates the checksum over the entire packet plus
1778 * the value of skb->csum. The latter can be used to supply the
1779 * checksum of a pseudo header as used by TCP/UDP. It returns the
1782 * For protocols that contain complete checksums such as ICMP/TCP/UDP,
1783 * this function can be used to verify that checksum on received
1784 * packets. In that case the function should return zero if the
1785 * checksum is correct. In particular, this function will return zero
1786 * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the
1787 * hardware has already verified the correctness of the checksum.
1789 static inline __sum16
skb_checksum_complete(struct sk_buff
*skb
)
1791 return skb_csum_unnecessary(skb
) ?
1792 0 : __skb_checksum_complete(skb
);
1795 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1796 extern void nf_conntrack_destroy(struct nf_conntrack
*nfct
);
1797 static inline void nf_conntrack_put(struct nf_conntrack
*nfct
)
1799 if (nfct
&& atomic_dec_and_test(&nfct
->use
))
1800 nf_conntrack_destroy(nfct
);
1802 static inline void nf_conntrack_get(struct nf_conntrack
*nfct
)
1805 atomic_inc(&nfct
->use
);
1807 static inline void nf_conntrack_get_reasm(struct sk_buff
*skb
)
1810 atomic_inc(&skb
->users
);
1812 static inline void nf_conntrack_put_reasm(struct sk_buff
*skb
)
1818 #ifdef CONFIG_BRIDGE_NETFILTER
1819 static inline void nf_bridge_put(struct nf_bridge_info
*nf_bridge
)
1821 if (nf_bridge
&& atomic_dec_and_test(&nf_bridge
->use
))
1824 static inline void nf_bridge_get(struct nf_bridge_info
*nf_bridge
)
1827 atomic_inc(&nf_bridge
->use
);
1829 #endif /* CONFIG_BRIDGE_NETFILTER */
1830 static inline void nf_reset(struct sk_buff
*skb
)
1832 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1833 nf_conntrack_put(skb
->nfct
);
1835 nf_conntrack_put_reasm(skb
->nfct_reasm
);
1836 skb
->nfct_reasm
= NULL
;
1838 #ifdef CONFIG_BRIDGE_NETFILTER
1839 nf_bridge_put(skb
->nf_bridge
);
1840 skb
->nf_bridge
= NULL
;
1844 /* Note: This doesn't put any conntrack and bridge info in dst. */
1845 static inline void __nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1847 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1848 dst
->nfct
= src
->nfct
;
1849 nf_conntrack_get(src
->nfct
);
1850 dst
->nfctinfo
= src
->nfctinfo
;
1851 dst
->nfct_reasm
= src
->nfct_reasm
;
1852 nf_conntrack_get_reasm(src
->nfct_reasm
);
1854 #ifdef CONFIG_BRIDGE_NETFILTER
1855 dst
->nf_bridge
= src
->nf_bridge
;
1856 nf_bridge_get(src
->nf_bridge
);
1860 static inline void nf_copy(struct sk_buff
*dst
, const struct sk_buff
*src
)
1862 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
1863 nf_conntrack_put(dst
->nfct
);
1864 nf_conntrack_put_reasm(dst
->nfct_reasm
);
1866 #ifdef CONFIG_BRIDGE_NETFILTER
1867 nf_bridge_put(dst
->nf_bridge
);
1869 __nf_copy(dst
, src
);
1872 #ifdef CONFIG_NETWORK_SECMARK
1873 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1875 to
->secmark
= from
->secmark
;
1878 static inline void skb_init_secmark(struct sk_buff
*skb
)
1883 static inline void skb_copy_secmark(struct sk_buff
*to
, const struct sk_buff
*from
)
1886 static inline void skb_init_secmark(struct sk_buff
*skb
)
1890 static inline void skb_set_queue_mapping(struct sk_buff
*skb
, u16 queue_mapping
)
1892 skb
->queue_mapping
= queue_mapping
;
1895 static inline u16
skb_get_queue_mapping(struct sk_buff
*skb
)
1897 return skb
->queue_mapping
;
1900 static inline void skb_copy_queue_mapping(struct sk_buff
*to
, const struct sk_buff
*from
)
1902 to
->queue_mapping
= from
->queue_mapping
;
1906 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
1911 static inline struct sec_path
*skb_sec_path(struct sk_buff
*skb
)
1917 static inline int skb_is_gso(const struct sk_buff
*skb
)
1919 return skb_shinfo(skb
)->gso_size
;
1922 static inline int skb_is_gso_v6(const struct sk_buff
*skb
)
1924 return skb_shinfo(skb
)->gso_type
& SKB_GSO_TCPV6
;
1927 extern void __skb_warn_lro_forwarding(const struct sk_buff
*skb
);
1929 static inline bool skb_warn_if_lro(const struct sk_buff
*skb
)
1931 /* LRO sets gso_size but not gso_type, whereas if GSO is really
1932 * wanted then gso_type will be set. */
1933 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
1934 if (shinfo
->gso_size
!= 0 && unlikely(shinfo
->gso_type
== 0)) {
1935 __skb_warn_lro_forwarding(skb
);
1941 static inline void skb_forward_csum(struct sk_buff
*skb
)
1943 /* Unfortunately we don't support this one. Any brave souls? */
1944 if (skb
->ip_summed
== CHECKSUM_COMPLETE
)
1945 skb
->ip_summed
= CHECKSUM_NONE
;
1948 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
);
1949 #endif /* __KERNEL__ */
1950 #endif /* _LINUX_SKBUFF_H */