2 * Routines having to do with the 'struct sk_buff' memory handlers.
4 * Authors: Alan Cox <iiitac@pyr.swan.ac.uk>
5 * Florian La Roche <rzsfl@rz.uni-sb.de>
8 * Alan Cox : Fixed the worst of the load
10 * Dave Platt : Interrupt stacking fix.
11 * Richard Kooijman : Timestamp fixes.
12 * Alan Cox : Changed buffer format.
13 * Alan Cox : destructor hook for AF_UNIX etc.
14 * Linus Torvalds : Better skb_clone.
15 * Alan Cox : Added skb_copy.
16 * Alan Cox : Added all the changed routines Linus
17 * only put in the headers
18 * Ray VanTassle : Fixed --skb->lock in free
19 * Alan Cox : skb_copy copy arp field
20 * Andi Kleen : slabified it.
21 * Robert Olsson : Removed skb_head_pool
24 * The __skb_ routines should be called with interrupts
25 * disabled, or you better be *real* sure that the operation is atomic
26 * with respect to whatever list is being frobbed (e.g. via lock_sock()
27 * or via disabling bottom half handlers, etc).
29 * This program is free software; you can redistribute it and/or
30 * modify it under the terms of the GNU General Public License
31 * as published by the Free Software Foundation; either version
32 * 2 of the License, or (at your option) any later version.
36 * The functions in this file will not compile correctly with gcc 2.4.x
39 #include <linux/module.h>
40 #include <linux/types.h>
41 #include <linux/kernel.h>
43 #include <linux/interrupt.h>
45 #include <linux/inet.h>
46 #include <linux/slab.h>
47 #include <linux/netdevice.h>
48 #ifdef CONFIG_NET_CLS_ACT
49 #include <net/pkt_sched.h>
51 #include <linux/string.h>
52 #include <linux/skbuff.h>
53 #include <linux/splice.h>
54 #include <linux/cache.h>
55 #include <linux/rtnetlink.h>
56 #include <linux/init.h>
57 #include <linux/scatterlist.h>
59 #include <net/protocol.h>
62 #include <net/checksum.h>
65 #include <asm/uaccess.h>
66 #include <asm/system.h>
70 static struct kmem_cache
*skbuff_head_cache __read_mostly
;
71 static struct kmem_cache
*skbuff_fclone_cache __read_mostly
;
73 static void sock_pipe_buf_release(struct pipe_inode_info
*pipe
,
74 struct pipe_buffer
*buf
)
76 struct sk_buff
*skb
= (struct sk_buff
*) buf
->private;
81 static void sock_pipe_buf_get(struct pipe_inode_info
*pipe
,
82 struct pipe_buffer
*buf
)
84 struct sk_buff
*skb
= (struct sk_buff
*) buf
->private;
89 static int sock_pipe_buf_steal(struct pipe_inode_info
*pipe
,
90 struct pipe_buffer
*buf
)
96 /* Pipe buffer operations for a socket. */
97 static struct pipe_buf_operations sock_pipe_buf_ops
= {
99 .map
= generic_pipe_buf_map
,
100 .unmap
= generic_pipe_buf_unmap
,
101 .confirm
= generic_pipe_buf_confirm
,
102 .release
= sock_pipe_buf_release
,
103 .steal
= sock_pipe_buf_steal
,
104 .get
= sock_pipe_buf_get
,
108 * Keep out-of-line to prevent kernel bloat.
109 * __builtin_return_address is not used because it is not always
114 * skb_over_panic - private function
119 * Out of line support code for skb_put(). Not user callable.
121 void skb_over_panic(struct sk_buff
*skb
, int sz
, void *here
)
123 printk(KERN_EMERG
"skb_over_panic: text:%p len:%d put:%d head:%p "
124 "data:%p tail:%#lx end:%#lx dev:%s\n",
125 here
, skb
->len
, sz
, skb
->head
, skb
->data
,
126 (unsigned long)skb
->tail
, (unsigned long)skb
->end
,
127 skb
->dev
? skb
->dev
->name
: "<NULL>");
132 * skb_under_panic - private function
137 * Out of line support code for skb_push(). Not user callable.
140 void skb_under_panic(struct sk_buff
*skb
, int sz
, void *here
)
142 printk(KERN_EMERG
"skb_under_panic: text:%p len:%d put:%d head:%p "
143 "data:%p tail:%#lx end:%#lx dev:%s\n",
144 here
, skb
->len
, sz
, skb
->head
, skb
->data
,
145 (unsigned long)skb
->tail
, (unsigned long)skb
->end
,
146 skb
->dev
? skb
->dev
->name
: "<NULL>");
150 void skb_truesize_bug(struct sk_buff
*skb
)
152 printk(KERN_ERR
"SKB BUG: Invalid truesize (%u) "
153 "len=%u, sizeof(sk_buff)=%Zd\n",
154 skb
->truesize
, skb
->len
, sizeof(struct sk_buff
));
156 EXPORT_SYMBOL(skb_truesize_bug
);
158 /* Allocate a new skbuff. We do this ourselves so we can fill in a few
159 * 'private' fields and also do memory statistics to find all the
165 * __alloc_skb - allocate a network buffer
166 * @size: size to allocate
167 * @gfp_mask: allocation mask
168 * @fclone: allocate from fclone cache instead of head cache
169 * and allocate a cloned (child) skb
170 * @node: numa node to allocate memory on
172 * Allocate a new &sk_buff. The returned buffer has no headroom and a
173 * tail room of size bytes. The object has a reference count of one.
174 * The return is the buffer. On a failure the return is %NULL.
176 * Buffers may only be allocated from interrupts using a @gfp_mask of
179 struct sk_buff
*__alloc_skb(unsigned int size
, gfp_t gfp_mask
,
180 int fclone
, int node
)
182 struct kmem_cache
*cache
;
183 struct skb_shared_info
*shinfo
;
187 cache
= fclone
? skbuff_fclone_cache
: skbuff_head_cache
;
190 skb
= kmem_cache_alloc_node(cache
, gfp_mask
& ~__GFP_DMA
, node
);
194 size
= SKB_DATA_ALIGN(size
);
195 data
= kmalloc_node_track_caller(size
+ sizeof(struct skb_shared_info
),
201 * Only clear those fields we need to clear, not those that we will
202 * actually initialise below. Hence, don't put any more fields after
203 * the tail pointer in struct sk_buff!
205 memset(skb
, 0, offsetof(struct sk_buff
, tail
));
206 skb
->truesize
= size
+ sizeof(struct sk_buff
);
207 atomic_set(&skb
->users
, 1);
210 skb_reset_tail_pointer(skb
);
211 skb
->end
= skb
->tail
+ size
;
212 /* make sure we initialize shinfo sequentially */
213 shinfo
= skb_shinfo(skb
);
214 atomic_set(&shinfo
->dataref
, 1);
215 shinfo
->nr_frags
= 0;
216 shinfo
->gso_size
= 0;
217 shinfo
->gso_segs
= 0;
218 shinfo
->gso_type
= 0;
219 shinfo
->ip6_frag_id
= 0;
220 shinfo
->frag_list
= NULL
;
223 struct sk_buff
*child
= skb
+ 1;
224 atomic_t
*fclone_ref
= (atomic_t
*) (child
+ 1);
226 skb
->fclone
= SKB_FCLONE_ORIG
;
227 atomic_set(fclone_ref
, 1);
229 child
->fclone
= SKB_FCLONE_UNAVAILABLE
;
234 kmem_cache_free(cache
, skb
);
240 * __netdev_alloc_skb - allocate an skbuff for rx on a specific device
241 * @dev: network device to receive on
242 * @length: length to allocate
243 * @gfp_mask: get_free_pages mask, passed to alloc_skb
245 * Allocate a new &sk_buff and assign it a usage count of one. The
246 * buffer has unspecified headroom built in. Users should allocate
247 * the headroom they think they need without accounting for the
248 * built in space. The built in space is used for optimisations.
250 * %NULL is returned if there is no free memory.
252 struct sk_buff
*__netdev_alloc_skb(struct net_device
*dev
,
253 unsigned int length
, gfp_t gfp_mask
)
255 int node
= dev
->dev
.parent
? dev_to_node(dev
->dev
.parent
) : -1;
258 skb
= __alloc_skb(length
+ NET_SKB_PAD
, gfp_mask
, 0, node
);
260 skb_reserve(skb
, NET_SKB_PAD
);
266 struct page
*__netdev_alloc_page(struct net_device
*dev
, gfp_t gfp_mask
)
268 int node
= dev
->dev
.parent
? dev_to_node(dev
->dev
.parent
) : -1;
271 page
= alloc_pages_node(node
, gfp_mask
, 0);
274 EXPORT_SYMBOL(__netdev_alloc_page
);
276 void skb_add_rx_frag(struct sk_buff
*skb
, int i
, struct page
*page
, int off
,
279 skb_fill_page_desc(skb
, i
, page
, off
, size
);
281 skb
->data_len
+= size
;
282 skb
->truesize
+= size
;
284 EXPORT_SYMBOL(skb_add_rx_frag
);
287 * dev_alloc_skb - allocate an skbuff for receiving
288 * @length: length to allocate
290 * Allocate a new &sk_buff and assign it a usage count of one. The
291 * buffer has unspecified headroom built in. Users should allocate
292 * the headroom they think they need without accounting for the
293 * built in space. The built in space is used for optimisations.
295 * %NULL is returned if there is no free memory. Although this function
296 * allocates memory it can be called from an interrupt.
298 struct sk_buff
*dev_alloc_skb(unsigned int length
)
301 * There is more code here than it seems:
302 * __dev_alloc_skb is an inline
304 return __dev_alloc_skb(length
, GFP_ATOMIC
);
306 EXPORT_SYMBOL(dev_alloc_skb
);
308 static void skb_drop_list(struct sk_buff
**listp
)
310 struct sk_buff
*list
= *listp
;
315 struct sk_buff
*this = list
;
321 static inline void skb_drop_fraglist(struct sk_buff
*skb
)
323 skb_drop_list(&skb_shinfo(skb
)->frag_list
);
326 static void skb_clone_fraglist(struct sk_buff
*skb
)
328 struct sk_buff
*list
;
330 for (list
= skb_shinfo(skb
)->frag_list
; list
; list
= list
->next
)
334 static void skb_release_data(struct sk_buff
*skb
)
337 !atomic_sub_return(skb
->nohdr
? (1 << SKB_DATAREF_SHIFT
) + 1 : 1,
338 &skb_shinfo(skb
)->dataref
)) {
339 if (skb_shinfo(skb
)->nr_frags
) {
341 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++)
342 put_page(skb_shinfo(skb
)->frags
[i
].page
);
345 if (skb_shinfo(skb
)->frag_list
)
346 skb_drop_fraglist(skb
);
353 * Free an skbuff by memory without cleaning the state.
355 static void kfree_skbmem(struct sk_buff
*skb
)
357 struct sk_buff
*other
;
358 atomic_t
*fclone_ref
;
360 switch (skb
->fclone
) {
361 case SKB_FCLONE_UNAVAILABLE
:
362 kmem_cache_free(skbuff_head_cache
, skb
);
365 case SKB_FCLONE_ORIG
:
366 fclone_ref
= (atomic_t
*) (skb
+ 2);
367 if (atomic_dec_and_test(fclone_ref
))
368 kmem_cache_free(skbuff_fclone_cache
, skb
);
371 case SKB_FCLONE_CLONE
:
372 fclone_ref
= (atomic_t
*) (skb
+ 1);
375 /* The clone portion is available for
376 * fast-cloning again.
378 skb
->fclone
= SKB_FCLONE_UNAVAILABLE
;
380 if (atomic_dec_and_test(fclone_ref
))
381 kmem_cache_free(skbuff_fclone_cache
, other
);
386 static void skb_release_head_state(struct sk_buff
*skb
)
388 dst_release(skb
->dst
);
390 secpath_put(skb
->sp
);
392 if (skb
->destructor
) {
394 skb
->destructor(skb
);
396 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
397 nf_conntrack_put(skb
->nfct
);
398 nf_conntrack_put_reasm(skb
->nfct_reasm
);
400 #ifdef CONFIG_BRIDGE_NETFILTER
401 nf_bridge_put(skb
->nf_bridge
);
403 /* XXX: IS this still necessary? - JHS */
404 #ifdef CONFIG_NET_SCHED
406 #ifdef CONFIG_NET_CLS_ACT
412 /* Free everything but the sk_buff shell. */
413 static void skb_release_all(struct sk_buff
*skb
)
415 skb_release_head_state(skb
);
416 skb_release_data(skb
);
420 * __kfree_skb - private function
423 * Free an sk_buff. Release anything attached to the buffer.
424 * Clean the state. This is an internal helper function. Users should
425 * always call kfree_skb
428 void __kfree_skb(struct sk_buff
*skb
)
430 skb_release_all(skb
);
435 * kfree_skb - free an sk_buff
436 * @skb: buffer to free
438 * Drop a reference to the buffer and free it if the usage count has
441 void kfree_skb(struct sk_buff
*skb
)
445 if (likely(atomic_read(&skb
->users
) == 1))
447 else if (likely(!atomic_dec_and_test(&skb
->users
)))
452 int skb_recycle_check(struct sk_buff
*skb
, int skb_size
)
454 struct skb_shared_info
*shinfo
;
456 if (skb_is_nonlinear(skb
) || skb
->fclone
!= SKB_FCLONE_UNAVAILABLE
)
459 skb_size
= SKB_DATA_ALIGN(skb_size
+ NET_SKB_PAD
);
460 if (skb_end_pointer(skb
) - skb
->head
< skb_size
)
463 if (skb_shared(skb
) || skb_cloned(skb
))
466 skb_release_head_state(skb
);
467 shinfo
= skb_shinfo(skb
);
468 atomic_set(&shinfo
->dataref
, 1);
469 shinfo
->nr_frags
= 0;
470 shinfo
->gso_size
= 0;
471 shinfo
->gso_segs
= 0;
472 shinfo
->gso_type
= 0;
473 shinfo
->ip6_frag_id
= 0;
474 shinfo
->frag_list
= NULL
;
476 memset(skb
, 0, offsetof(struct sk_buff
, tail
));
477 skb_reset_tail_pointer(skb
);
478 skb
->data
= skb
->head
+ NET_SKB_PAD
;
482 EXPORT_SYMBOL(skb_recycle_check
);
484 static void __copy_skb_header(struct sk_buff
*new, const struct sk_buff
*old
)
486 new->tstamp
= old
->tstamp
;
488 new->transport_header
= old
->transport_header
;
489 new->network_header
= old
->network_header
;
490 new->mac_header
= old
->mac_header
;
491 new->dst
= dst_clone(old
->dst
);
493 new->sp
= secpath_get(old
->sp
);
495 memcpy(new->cb
, old
->cb
, sizeof(old
->cb
));
496 new->csum_start
= old
->csum_start
;
497 new->csum_offset
= old
->csum_offset
;
498 new->local_df
= old
->local_df
;
499 new->pkt_type
= old
->pkt_type
;
500 new->ip_summed
= old
->ip_summed
;
501 skb_copy_queue_mapping(new, old
);
502 new->priority
= old
->priority
;
503 #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
504 new->ipvs_property
= old
->ipvs_property
;
506 new->protocol
= old
->protocol
;
507 new->mark
= old
->mark
;
509 #if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
510 defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
511 new->nf_trace
= old
->nf_trace
;
513 #ifdef CONFIG_NET_SCHED
514 new->tc_index
= old
->tc_index
;
515 #ifdef CONFIG_NET_CLS_ACT
516 new->tc_verd
= old
->tc_verd
;
519 new->vlan_tci
= old
->vlan_tci
;
521 skb_copy_secmark(new, old
);
524 static struct sk_buff
*__skb_clone(struct sk_buff
*n
, struct sk_buff
*skb
)
526 #define C(x) n->x = skb->x
528 n
->next
= n
->prev
= NULL
;
530 __copy_skb_header(n
, skb
);
535 n
->hdr_len
= skb
->nohdr
? skb_headroom(skb
) : skb
->hdr_len
;
538 n
->destructor
= NULL
;
545 #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE)
548 atomic_set(&n
->users
, 1);
550 atomic_inc(&(skb_shinfo(skb
)->dataref
));
558 * skb_morph - morph one skb into another
559 * @dst: the skb to receive the contents
560 * @src: the skb to supply the contents
562 * This is identical to skb_clone except that the target skb is
563 * supplied by the user.
565 * The target skb is returned upon exit.
567 struct sk_buff
*skb_morph(struct sk_buff
*dst
, struct sk_buff
*src
)
569 skb_release_all(dst
);
570 return __skb_clone(dst
, src
);
572 EXPORT_SYMBOL_GPL(skb_morph
);
575 * skb_clone - duplicate an sk_buff
576 * @skb: buffer to clone
577 * @gfp_mask: allocation priority
579 * Duplicate an &sk_buff. The new one is not owned by a socket. Both
580 * copies share the same packet data but not structure. The new
581 * buffer has a reference count of 1. If the allocation fails the
582 * function returns %NULL otherwise the new buffer is returned.
584 * If this function is called from an interrupt gfp_mask() must be
588 struct sk_buff
*skb_clone(struct sk_buff
*skb
, gfp_t gfp_mask
)
593 if (skb
->fclone
== SKB_FCLONE_ORIG
&&
594 n
->fclone
== SKB_FCLONE_UNAVAILABLE
) {
595 atomic_t
*fclone_ref
= (atomic_t
*) (n
+ 1);
596 n
->fclone
= SKB_FCLONE_CLONE
;
597 atomic_inc(fclone_ref
);
599 n
= kmem_cache_alloc(skbuff_head_cache
, gfp_mask
);
602 n
->fclone
= SKB_FCLONE_UNAVAILABLE
;
605 return __skb_clone(n
, skb
);
608 static void copy_skb_header(struct sk_buff
*new, const struct sk_buff
*old
)
610 #ifndef NET_SKBUFF_DATA_USES_OFFSET
612 * Shift between the two data areas in bytes
614 unsigned long offset
= new->data
- old
->data
;
617 __copy_skb_header(new, old
);
619 #ifndef NET_SKBUFF_DATA_USES_OFFSET
620 /* {transport,network,mac}_header are relative to skb->head */
621 new->transport_header
+= offset
;
622 new->network_header
+= offset
;
623 new->mac_header
+= offset
;
625 skb_shinfo(new)->gso_size
= skb_shinfo(old
)->gso_size
;
626 skb_shinfo(new)->gso_segs
= skb_shinfo(old
)->gso_segs
;
627 skb_shinfo(new)->gso_type
= skb_shinfo(old
)->gso_type
;
631 * skb_copy - create private copy of an sk_buff
632 * @skb: buffer to copy
633 * @gfp_mask: allocation priority
635 * Make a copy of both an &sk_buff and its data. This is used when the
636 * caller wishes to modify the data and needs a private copy of the
637 * data to alter. Returns %NULL on failure or the pointer to the buffer
638 * on success. The returned buffer has a reference count of 1.
640 * As by-product this function converts non-linear &sk_buff to linear
641 * one, so that &sk_buff becomes completely private and caller is allowed
642 * to modify all the data of returned buffer. This means that this
643 * function is not recommended for use in circumstances when only
644 * header is going to be modified. Use pskb_copy() instead.
647 struct sk_buff
*skb_copy(const struct sk_buff
*skb
, gfp_t gfp_mask
)
649 int headerlen
= skb
->data
- skb
->head
;
651 * Allocate the copy buffer
654 #ifdef NET_SKBUFF_DATA_USES_OFFSET
655 n
= alloc_skb(skb
->end
+ skb
->data_len
, gfp_mask
);
657 n
= alloc_skb(skb
->end
- skb
->head
+ skb
->data_len
, gfp_mask
);
662 /* Set the data pointer */
663 skb_reserve(n
, headerlen
);
664 /* Set the tail pointer and length */
665 skb_put(n
, skb
->len
);
667 if (skb_copy_bits(skb
, -headerlen
, n
->head
, headerlen
+ skb
->len
))
670 copy_skb_header(n
, skb
);
676 * pskb_copy - create copy of an sk_buff with private head.
677 * @skb: buffer to copy
678 * @gfp_mask: allocation priority
680 * Make a copy of both an &sk_buff and part of its data, located
681 * in header. Fragmented data remain shared. This is used when
682 * the caller wishes to modify only header of &sk_buff and needs
683 * private copy of the header to alter. Returns %NULL on failure
684 * or the pointer to the buffer on success.
685 * The returned buffer has a reference count of 1.
688 struct sk_buff
*pskb_copy(struct sk_buff
*skb
, gfp_t gfp_mask
)
691 * Allocate the copy buffer
694 #ifdef NET_SKBUFF_DATA_USES_OFFSET
695 n
= alloc_skb(skb
->end
, gfp_mask
);
697 n
= alloc_skb(skb
->end
- skb
->head
, gfp_mask
);
702 /* Set the data pointer */
703 skb_reserve(n
, skb
->data
- skb
->head
);
704 /* Set the tail pointer and length */
705 skb_put(n
, skb_headlen(skb
));
707 skb_copy_from_linear_data(skb
, n
->data
, n
->len
);
709 n
->truesize
+= skb
->data_len
;
710 n
->data_len
= skb
->data_len
;
713 if (skb_shinfo(skb
)->nr_frags
) {
716 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
717 skb_shinfo(n
)->frags
[i
] = skb_shinfo(skb
)->frags
[i
];
718 get_page(skb_shinfo(n
)->frags
[i
].page
);
720 skb_shinfo(n
)->nr_frags
= i
;
723 if (skb_shinfo(skb
)->frag_list
) {
724 skb_shinfo(n
)->frag_list
= skb_shinfo(skb
)->frag_list
;
725 skb_clone_fraglist(n
);
728 copy_skb_header(n
, skb
);
734 * pskb_expand_head - reallocate header of &sk_buff
735 * @skb: buffer to reallocate
736 * @nhead: room to add at head
737 * @ntail: room to add at tail
738 * @gfp_mask: allocation priority
740 * Expands (or creates identical copy, if &nhead and &ntail are zero)
741 * header of skb. &sk_buff itself is not changed. &sk_buff MUST have
742 * reference count of 1. Returns zero in the case of success or error,
743 * if expansion failed. In the last case, &sk_buff is not changed.
745 * All the pointers pointing into skb header may change and must be
746 * reloaded after call to this function.
749 int pskb_expand_head(struct sk_buff
*skb
, int nhead
, int ntail
,
754 #ifdef NET_SKBUFF_DATA_USES_OFFSET
755 int size
= nhead
+ skb
->end
+ ntail
;
757 int size
= nhead
+ (skb
->end
- skb
->head
) + ntail
;
766 size
= SKB_DATA_ALIGN(size
);
768 data
= kmalloc(size
+ sizeof(struct skb_shared_info
), gfp_mask
);
772 /* Copy only real data... and, alas, header. This should be
773 * optimized for the cases when header is void. */
774 #ifdef NET_SKBUFF_DATA_USES_OFFSET
775 memcpy(data
+ nhead
, skb
->head
, skb
->tail
);
777 memcpy(data
+ nhead
, skb
->head
, skb
->tail
- skb
->head
);
779 memcpy(data
+ size
, skb_end_pointer(skb
),
780 sizeof(struct skb_shared_info
));
782 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++)
783 get_page(skb_shinfo(skb
)->frags
[i
].page
);
785 if (skb_shinfo(skb
)->frag_list
)
786 skb_clone_fraglist(skb
);
788 skb_release_data(skb
);
790 off
= (data
+ nhead
) - skb
->head
;
794 #ifdef NET_SKBUFF_DATA_USES_OFFSET
798 skb
->end
= skb
->head
+ size
;
800 /* {transport,network,mac}_header and tail are relative to skb->head */
802 skb
->transport_header
+= off
;
803 skb
->network_header
+= off
;
804 skb
->mac_header
+= off
;
805 skb
->csum_start
+= nhead
;
809 atomic_set(&skb_shinfo(skb
)->dataref
, 1);
816 /* Make private copy of skb with writable head and some headroom */
818 struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
, unsigned int headroom
)
820 struct sk_buff
*skb2
;
821 int delta
= headroom
- skb_headroom(skb
);
824 skb2
= pskb_copy(skb
, GFP_ATOMIC
);
826 skb2
= skb_clone(skb
, GFP_ATOMIC
);
827 if (skb2
&& pskb_expand_head(skb2
, SKB_DATA_ALIGN(delta
), 0,
838 * skb_copy_expand - copy and expand sk_buff
839 * @skb: buffer to copy
840 * @newheadroom: new free bytes at head
841 * @newtailroom: new free bytes at tail
842 * @gfp_mask: allocation priority
844 * Make a copy of both an &sk_buff and its data and while doing so
845 * allocate additional space.
847 * This is used when the caller wishes to modify the data and needs a
848 * private copy of the data to alter as well as more space for new fields.
849 * Returns %NULL on failure or the pointer to the buffer
850 * on success. The returned buffer has a reference count of 1.
852 * You must pass %GFP_ATOMIC as the allocation priority if this function
853 * is called from an interrupt.
855 struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
856 int newheadroom
, int newtailroom
,
860 * Allocate the copy buffer
862 struct sk_buff
*n
= alloc_skb(newheadroom
+ skb
->len
+ newtailroom
,
864 int oldheadroom
= skb_headroom(skb
);
865 int head_copy_len
, head_copy_off
;
871 skb_reserve(n
, newheadroom
);
873 /* Set the tail pointer and length */
874 skb_put(n
, skb
->len
);
876 head_copy_len
= oldheadroom
;
878 if (newheadroom
<= head_copy_len
)
879 head_copy_len
= newheadroom
;
881 head_copy_off
= newheadroom
- head_copy_len
;
883 /* Copy the linear header and data. */
884 if (skb_copy_bits(skb
, -head_copy_len
, n
->head
+ head_copy_off
,
885 skb
->len
+ head_copy_len
))
888 copy_skb_header(n
, skb
);
890 off
= newheadroom
- oldheadroom
;
891 n
->csum_start
+= off
;
892 #ifdef NET_SKBUFF_DATA_USES_OFFSET
893 n
->transport_header
+= off
;
894 n
->network_header
+= off
;
895 n
->mac_header
+= off
;
902 * skb_pad - zero pad the tail of an skb
903 * @skb: buffer to pad
906 * Ensure that a buffer is followed by a padding area that is zero
907 * filled. Used by network drivers which may DMA or transfer data
908 * beyond the buffer end onto the wire.
910 * May return error in out of memory cases. The skb is freed on error.
913 int skb_pad(struct sk_buff
*skb
, int pad
)
918 /* If the skbuff is non linear tailroom is always zero.. */
919 if (!skb_cloned(skb
) && skb_tailroom(skb
) >= pad
) {
920 memset(skb
->data
+skb
->len
, 0, pad
);
924 ntail
= skb
->data_len
+ pad
- (skb
->end
- skb
->tail
);
925 if (likely(skb_cloned(skb
) || ntail
> 0)) {
926 err
= pskb_expand_head(skb
, 0, ntail
, GFP_ATOMIC
);
931 /* FIXME: The use of this function with non-linear skb's really needs
934 err
= skb_linearize(skb
);
938 memset(skb
->data
+ skb
->len
, 0, pad
);
947 * skb_put - add data to a buffer
948 * @skb: buffer to use
949 * @len: amount of data to add
951 * This function extends the used data area of the buffer. If this would
952 * exceed the total buffer size the kernel will panic. A pointer to the
953 * first byte of the extra data is returned.
955 unsigned char *skb_put(struct sk_buff
*skb
, unsigned int len
)
957 unsigned char *tmp
= skb_tail_pointer(skb
);
958 SKB_LINEAR_ASSERT(skb
);
961 if (unlikely(skb
->tail
> skb
->end
))
962 skb_over_panic(skb
, len
, __builtin_return_address(0));
965 EXPORT_SYMBOL(skb_put
);
968 * skb_push - add data to the start of a buffer
969 * @skb: buffer to use
970 * @len: amount of data to add
972 * This function extends the used data area of the buffer at the buffer
973 * start. If this would exceed the total buffer headroom the kernel will
974 * panic. A pointer to the first byte of the extra data is returned.
976 unsigned char *skb_push(struct sk_buff
*skb
, unsigned int len
)
980 if (unlikely(skb
->data
<skb
->head
))
981 skb_under_panic(skb
, len
, __builtin_return_address(0));
984 EXPORT_SYMBOL(skb_push
);
987 * skb_pull - remove data from the start of a buffer
988 * @skb: buffer to use
989 * @len: amount of data to remove
991 * This function removes data from the start of a buffer, returning
992 * the memory to the headroom. A pointer to the next data in the buffer
993 * is returned. Once the data has been pulled future pushes will overwrite
996 unsigned char *skb_pull(struct sk_buff
*skb
, unsigned int len
)
998 return unlikely(len
> skb
->len
) ? NULL
: __skb_pull(skb
, len
);
1000 EXPORT_SYMBOL(skb_pull
);
1003 * skb_trim - remove end from a buffer
1004 * @skb: buffer to alter
1007 * Cut the length of a buffer down by removing data from the tail. If
1008 * the buffer is already under the length specified it is not modified.
1009 * The skb must be linear.
1011 void skb_trim(struct sk_buff
*skb
, unsigned int len
)
1014 __skb_trim(skb
, len
);
1016 EXPORT_SYMBOL(skb_trim
);
1018 /* Trims skb to length len. It can change skb pointers.
1021 int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
)
1023 struct sk_buff
**fragp
;
1024 struct sk_buff
*frag
;
1025 int offset
= skb_headlen(skb
);
1026 int nfrags
= skb_shinfo(skb
)->nr_frags
;
1030 if (skb_cloned(skb
) &&
1031 unlikely((err
= pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
))))
1038 for (; i
< nfrags
; i
++) {
1039 int end
= offset
+ skb_shinfo(skb
)->frags
[i
].size
;
1046 skb_shinfo(skb
)->frags
[i
++].size
= len
- offset
;
1049 skb_shinfo(skb
)->nr_frags
= i
;
1051 for (; i
< nfrags
; i
++)
1052 put_page(skb_shinfo(skb
)->frags
[i
].page
);
1054 if (skb_shinfo(skb
)->frag_list
)
1055 skb_drop_fraglist(skb
);
1059 for (fragp
= &skb_shinfo(skb
)->frag_list
; (frag
= *fragp
);
1060 fragp
= &frag
->next
) {
1061 int end
= offset
+ frag
->len
;
1063 if (skb_shared(frag
)) {
1064 struct sk_buff
*nfrag
;
1066 nfrag
= skb_clone(frag
, GFP_ATOMIC
);
1067 if (unlikely(!nfrag
))
1070 nfrag
->next
= frag
->next
;
1082 unlikely((err
= pskb_trim(frag
, len
- offset
))))
1086 skb_drop_list(&frag
->next
);
1091 if (len
> skb_headlen(skb
)) {
1092 skb
->data_len
-= skb
->len
- len
;
1097 skb_set_tail_pointer(skb
, len
);
1104 * __pskb_pull_tail - advance tail of skb header
1105 * @skb: buffer to reallocate
1106 * @delta: number of bytes to advance tail
1108 * The function makes a sense only on a fragmented &sk_buff,
1109 * it expands header moving its tail forward and copying necessary
1110 * data from fragmented part.
1112 * &sk_buff MUST have reference count of 1.
1114 * Returns %NULL (and &sk_buff does not change) if pull failed
1115 * or value of new tail of skb in the case of success.
1117 * All the pointers pointing into skb header may change and must be
1118 * reloaded after call to this function.
1121 /* Moves tail of skb head forward, copying data from fragmented part,
1122 * when it is necessary.
1123 * 1. It may fail due to malloc failure.
1124 * 2. It may change skb pointers.
1126 * It is pretty complicated. Luckily, it is called only in exceptional cases.
1128 unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
)
1130 /* If skb has not enough free space at tail, get new one
1131 * plus 128 bytes for future expansions. If we have enough
1132 * room at tail, reallocate without expansion only if skb is cloned.
1134 int i
, k
, eat
= (skb
->tail
+ delta
) - skb
->end
;
1136 if (eat
> 0 || skb_cloned(skb
)) {
1137 if (pskb_expand_head(skb
, 0, eat
> 0 ? eat
+ 128 : 0,
1142 if (skb_copy_bits(skb
, skb_headlen(skb
), skb_tail_pointer(skb
), delta
))
1145 /* Optimization: no fragments, no reasons to preestimate
1146 * size of pulled pages. Superb.
1148 if (!skb_shinfo(skb
)->frag_list
)
1151 /* Estimate size of pulled pages. */
1153 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1154 if (skb_shinfo(skb
)->frags
[i
].size
>= eat
)
1156 eat
-= skb_shinfo(skb
)->frags
[i
].size
;
1159 /* If we need update frag list, we are in troubles.
1160 * Certainly, it possible to add an offset to skb data,
1161 * but taking into account that pulling is expected to
1162 * be very rare operation, it is worth to fight against
1163 * further bloating skb head and crucify ourselves here instead.
1164 * Pure masohism, indeed. 8)8)
1167 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1168 struct sk_buff
*clone
= NULL
;
1169 struct sk_buff
*insp
= NULL
;
1174 if (list
->len
<= eat
) {
1175 /* Eaten as whole. */
1180 /* Eaten partially. */
1182 if (skb_shared(list
)) {
1183 /* Sucks! We need to fork list. :-( */
1184 clone
= skb_clone(list
, GFP_ATOMIC
);
1190 /* This may be pulled without
1194 if (!pskb_pull(list
, eat
)) {
1203 /* Free pulled out fragments. */
1204 while ((list
= skb_shinfo(skb
)->frag_list
) != insp
) {
1205 skb_shinfo(skb
)->frag_list
= list
->next
;
1208 /* And insert new clone at head. */
1211 skb_shinfo(skb
)->frag_list
= clone
;
1214 /* Success! Now we may commit changes to skb data. */
1219 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1220 if (skb_shinfo(skb
)->frags
[i
].size
<= eat
) {
1221 put_page(skb_shinfo(skb
)->frags
[i
].page
);
1222 eat
-= skb_shinfo(skb
)->frags
[i
].size
;
1224 skb_shinfo(skb
)->frags
[k
] = skb_shinfo(skb
)->frags
[i
];
1226 skb_shinfo(skb
)->frags
[k
].page_offset
+= eat
;
1227 skb_shinfo(skb
)->frags
[k
].size
-= eat
;
1233 skb_shinfo(skb
)->nr_frags
= k
;
1236 skb
->data_len
-= delta
;
1238 return skb_tail_pointer(skb
);
1241 /* Copy some data bits from skb to kernel buffer. */
1243 int skb_copy_bits(const struct sk_buff
*skb
, int offset
, void *to
, int len
)
1246 int start
= skb_headlen(skb
);
1248 if (offset
> (int)skb
->len
- len
)
1252 if ((copy
= start
- offset
) > 0) {
1255 skb_copy_from_linear_data_offset(skb
, offset
, to
, copy
);
1256 if ((len
-= copy
) == 0)
1262 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1265 WARN_ON(start
> offset
+ len
);
1267 end
= start
+ skb_shinfo(skb
)->frags
[i
].size
;
1268 if ((copy
= end
- offset
) > 0) {
1274 vaddr
= kmap_skb_frag(&skb_shinfo(skb
)->frags
[i
]);
1276 vaddr
+ skb_shinfo(skb
)->frags
[i
].page_offset
+
1277 offset
- start
, copy
);
1278 kunmap_skb_frag(vaddr
);
1280 if ((len
-= copy
) == 0)
1288 if (skb_shinfo(skb
)->frag_list
) {
1289 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1291 for (; list
; list
= list
->next
) {
1294 WARN_ON(start
> offset
+ len
);
1296 end
= start
+ list
->len
;
1297 if ((copy
= end
- offset
) > 0) {
1300 if (skb_copy_bits(list
, offset
- start
,
1303 if ((len
-= copy
) == 0)
1319 * Callback from splice_to_pipe(), if we need to release some pages
1320 * at the end of the spd in case we error'ed out in filling the pipe.
1322 static void sock_spd_release(struct splice_pipe_desc
*spd
, unsigned int i
)
1324 struct sk_buff
*skb
= (struct sk_buff
*) spd
->partial
[i
].private;
1330 * Fill page/offset/length into spd, if it can hold more pages.
1332 static inline int spd_fill_page(struct splice_pipe_desc
*spd
, struct page
*page
,
1333 unsigned int len
, unsigned int offset
,
1334 struct sk_buff
*skb
)
1336 if (unlikely(spd
->nr_pages
== PIPE_BUFFERS
))
1339 spd
->pages
[spd
->nr_pages
] = page
;
1340 spd
->partial
[spd
->nr_pages
].len
= len
;
1341 spd
->partial
[spd
->nr_pages
].offset
= offset
;
1342 spd
->partial
[spd
->nr_pages
].private = (unsigned long) skb_get(skb
);
1347 static inline void __segment_seek(struct page
**page
, unsigned int *poff
,
1348 unsigned int *plen
, unsigned int off
)
1351 *page
+= *poff
/ PAGE_SIZE
;
1352 *poff
= *poff
% PAGE_SIZE
;
1356 static inline int __splice_segment(struct page
*page
, unsigned int poff
,
1357 unsigned int plen
, unsigned int *off
,
1358 unsigned int *len
, struct sk_buff
*skb
,
1359 struct splice_pipe_desc
*spd
)
1364 /* skip this segment if already processed */
1370 /* ignore any bits we already processed */
1372 __segment_seek(&page
, &poff
, &plen
, *off
);
1377 unsigned int flen
= min(*len
, plen
);
1379 /* the linear region may spread across several pages */
1380 flen
= min_t(unsigned int, flen
, PAGE_SIZE
- poff
);
1382 if (spd_fill_page(spd
, page
, flen
, poff
, skb
))
1385 __segment_seek(&page
, &poff
, &plen
, flen
);
1388 } while (*len
&& plen
);
1394 * Map linear and fragment data from the skb to spd. It reports failure if the
1395 * pipe is full or if we already spliced the requested length.
1397 static int __skb_splice_bits(struct sk_buff
*skb
, unsigned int *offset
,
1399 struct splice_pipe_desc
*spd
)
1404 * map the linear part
1406 if (__splice_segment(virt_to_page(skb
->data
),
1407 (unsigned long) skb
->data
& (PAGE_SIZE
- 1),
1409 offset
, len
, skb
, spd
))
1413 * then map the fragments
1415 for (seg
= 0; seg
< skb_shinfo(skb
)->nr_frags
; seg
++) {
1416 const skb_frag_t
*f
= &skb_shinfo(skb
)->frags
[seg
];
1418 if (__splice_segment(f
->page
, f
->page_offset
, f
->size
,
1419 offset
, len
, skb
, spd
))
1427 * Map data from the skb to a pipe. Should handle both the linear part,
1428 * the fragments, and the frag list. It does NOT handle frag lists within
1429 * the frag list, if such a thing exists. We'd probably need to recurse to
1430 * handle that cleanly.
1432 int skb_splice_bits(struct sk_buff
*__skb
, unsigned int offset
,
1433 struct pipe_inode_info
*pipe
, unsigned int tlen
,
1436 struct partial_page partial
[PIPE_BUFFERS
];
1437 struct page
*pages
[PIPE_BUFFERS
];
1438 struct splice_pipe_desc spd
= {
1442 .ops
= &sock_pipe_buf_ops
,
1443 .spd_release
= sock_spd_release
,
1445 struct sk_buff
*skb
;
1448 * I'd love to avoid the clone here, but tcp_read_sock()
1449 * ignores reference counts and unconditonally kills the sk_buff
1450 * on return from the actor.
1452 skb
= skb_clone(__skb
, GFP_KERNEL
);
1457 * __skb_splice_bits() only fails if the output has no room left,
1458 * so no point in going over the frag_list for the error case.
1460 if (__skb_splice_bits(skb
, &offset
, &tlen
, &spd
))
1466 * now see if we have a frag_list to map
1468 if (skb_shinfo(skb
)->frag_list
) {
1469 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1471 for (; list
&& tlen
; list
= list
->next
) {
1472 if (__skb_splice_bits(list
, &offset
, &tlen
, &spd
))
1479 * drop our reference to the clone, the pipe consumption will
1486 struct sock
*sk
= __skb
->sk
;
1489 * Drop the socket lock, otherwise we have reverse
1490 * locking dependencies between sk_lock and i_mutex
1491 * here as compared to sendfile(). We enter here
1492 * with the socket lock held, and splice_to_pipe() will
1493 * grab the pipe inode lock. For sendfile() emulation,
1494 * we call into ->sendpage() with the i_mutex lock held
1495 * and networking will grab the socket lock.
1498 ret
= splice_to_pipe(pipe
, &spd
);
1507 * skb_store_bits - store bits from kernel buffer to skb
1508 * @skb: destination buffer
1509 * @offset: offset in destination
1510 * @from: source buffer
1511 * @len: number of bytes to copy
1513 * Copy the specified number of bytes from the source buffer to the
1514 * destination skb. This function handles all the messy bits of
1515 * traversing fragment lists and such.
1518 int skb_store_bits(struct sk_buff
*skb
, int offset
, const void *from
, int len
)
1521 int start
= skb_headlen(skb
);
1523 if (offset
> (int)skb
->len
- len
)
1526 if ((copy
= start
- offset
) > 0) {
1529 skb_copy_to_linear_data_offset(skb
, offset
, from
, copy
);
1530 if ((len
-= copy
) == 0)
1536 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1537 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1540 WARN_ON(start
> offset
+ len
);
1542 end
= start
+ frag
->size
;
1543 if ((copy
= end
- offset
) > 0) {
1549 vaddr
= kmap_skb_frag(frag
);
1550 memcpy(vaddr
+ frag
->page_offset
+ offset
- start
,
1552 kunmap_skb_frag(vaddr
);
1554 if ((len
-= copy
) == 0)
1562 if (skb_shinfo(skb
)->frag_list
) {
1563 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1565 for (; list
; list
= list
->next
) {
1568 WARN_ON(start
> offset
+ len
);
1570 end
= start
+ list
->len
;
1571 if ((copy
= end
- offset
) > 0) {
1574 if (skb_store_bits(list
, offset
- start
,
1577 if ((len
-= copy
) == 0)
1592 EXPORT_SYMBOL(skb_store_bits
);
1594 /* Checksum skb data. */
1596 __wsum
skb_checksum(const struct sk_buff
*skb
, int offset
,
1597 int len
, __wsum csum
)
1599 int start
= skb_headlen(skb
);
1600 int i
, copy
= start
- offset
;
1603 /* Checksum header. */
1607 csum
= csum_partial(skb
->data
+ offset
, copy
, csum
);
1608 if ((len
-= copy
) == 0)
1614 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1617 WARN_ON(start
> offset
+ len
);
1619 end
= start
+ skb_shinfo(skb
)->frags
[i
].size
;
1620 if ((copy
= end
- offset
) > 0) {
1623 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1627 vaddr
= kmap_skb_frag(frag
);
1628 csum2
= csum_partial(vaddr
+ frag
->page_offset
+
1629 offset
- start
, copy
, 0);
1630 kunmap_skb_frag(vaddr
);
1631 csum
= csum_block_add(csum
, csum2
, pos
);
1640 if (skb_shinfo(skb
)->frag_list
) {
1641 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1643 for (; list
; list
= list
->next
) {
1646 WARN_ON(start
> offset
+ len
);
1648 end
= start
+ list
->len
;
1649 if ((copy
= end
- offset
) > 0) {
1653 csum2
= skb_checksum(list
, offset
- start
,
1655 csum
= csum_block_add(csum
, csum2
, pos
);
1656 if ((len
-= copy
) == 0)
1669 /* Both of above in one bottle. */
1671 __wsum
skb_copy_and_csum_bits(const struct sk_buff
*skb
, int offset
,
1672 u8
*to
, int len
, __wsum csum
)
1674 int start
= skb_headlen(skb
);
1675 int i
, copy
= start
- offset
;
1682 csum
= csum_partial_copy_nocheck(skb
->data
+ offset
, to
,
1684 if ((len
-= copy
) == 0)
1691 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1694 WARN_ON(start
> offset
+ len
);
1696 end
= start
+ skb_shinfo(skb
)->frags
[i
].size
;
1697 if ((copy
= end
- offset
) > 0) {
1700 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1704 vaddr
= kmap_skb_frag(frag
);
1705 csum2
= csum_partial_copy_nocheck(vaddr
+
1709 kunmap_skb_frag(vaddr
);
1710 csum
= csum_block_add(csum
, csum2
, pos
);
1720 if (skb_shinfo(skb
)->frag_list
) {
1721 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1723 for (; list
; list
= list
->next
) {
1727 WARN_ON(start
> offset
+ len
);
1729 end
= start
+ list
->len
;
1730 if ((copy
= end
- offset
) > 0) {
1733 csum2
= skb_copy_and_csum_bits(list
,
1736 csum
= csum_block_add(csum
, csum2
, pos
);
1737 if ((len
-= copy
) == 0)
1750 void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
)
1755 if (skb
->ip_summed
== CHECKSUM_PARTIAL
)
1756 csstart
= skb
->csum_start
- skb_headroom(skb
);
1758 csstart
= skb_headlen(skb
);
1760 BUG_ON(csstart
> skb_headlen(skb
));
1762 skb_copy_from_linear_data(skb
, to
, csstart
);
1765 if (csstart
!= skb
->len
)
1766 csum
= skb_copy_and_csum_bits(skb
, csstart
, to
+ csstart
,
1767 skb
->len
- csstart
, 0);
1769 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
1770 long csstuff
= csstart
+ skb
->csum_offset
;
1772 *((__sum16
*)(to
+ csstuff
)) = csum_fold(csum
);
1777 * skb_dequeue - remove from the head of the queue
1778 * @list: list to dequeue from
1780 * Remove the head of the list. The list lock is taken so the function
1781 * may be used safely with other locking list functions. The head item is
1782 * returned or %NULL if the list is empty.
1785 struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
)
1787 unsigned long flags
;
1788 struct sk_buff
*result
;
1790 spin_lock_irqsave(&list
->lock
, flags
);
1791 result
= __skb_dequeue(list
);
1792 spin_unlock_irqrestore(&list
->lock
, flags
);
1797 * skb_dequeue_tail - remove from the tail of the queue
1798 * @list: list to dequeue from
1800 * Remove the tail of the list. The list lock is taken so the function
1801 * may be used safely with other locking list functions. The tail item is
1802 * returned or %NULL if the list is empty.
1804 struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
)
1806 unsigned long flags
;
1807 struct sk_buff
*result
;
1809 spin_lock_irqsave(&list
->lock
, flags
);
1810 result
= __skb_dequeue_tail(list
);
1811 spin_unlock_irqrestore(&list
->lock
, flags
);
1816 * skb_queue_purge - empty a list
1817 * @list: list to empty
1819 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1820 * the list and one reference dropped. This function takes the list
1821 * lock and is atomic with respect to other list locking functions.
1823 void skb_queue_purge(struct sk_buff_head
*list
)
1825 struct sk_buff
*skb
;
1826 while ((skb
= skb_dequeue(list
)) != NULL
)
1831 * skb_queue_head - queue a buffer at the list head
1832 * @list: list to use
1833 * @newsk: buffer to queue
1835 * Queue a buffer at the start of the list. This function takes the
1836 * list lock and can be used safely with other locking &sk_buff functions
1839 * A buffer cannot be placed on two lists at the same time.
1841 void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
)
1843 unsigned long flags
;
1845 spin_lock_irqsave(&list
->lock
, flags
);
1846 __skb_queue_head(list
, newsk
);
1847 spin_unlock_irqrestore(&list
->lock
, flags
);
1851 * skb_queue_tail - queue a buffer at the list tail
1852 * @list: list to use
1853 * @newsk: buffer to queue
1855 * Queue a buffer at the tail of the list. This function takes the
1856 * list lock and can be used safely with other locking &sk_buff functions
1859 * A buffer cannot be placed on two lists at the same time.
1861 void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
)
1863 unsigned long flags
;
1865 spin_lock_irqsave(&list
->lock
, flags
);
1866 __skb_queue_tail(list
, newsk
);
1867 spin_unlock_irqrestore(&list
->lock
, flags
);
1871 * skb_unlink - remove a buffer from a list
1872 * @skb: buffer to remove
1873 * @list: list to use
1875 * Remove a packet from a list. The list locks are taken and this
1876 * function is atomic with respect to other list locked calls
1878 * You must know what list the SKB is on.
1880 void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1882 unsigned long flags
;
1884 spin_lock_irqsave(&list
->lock
, flags
);
1885 __skb_unlink(skb
, list
);
1886 spin_unlock_irqrestore(&list
->lock
, flags
);
1890 * skb_append - append a buffer
1891 * @old: buffer to insert after
1892 * @newsk: buffer to insert
1893 * @list: list to use
1895 * Place a packet after a given packet in a list. The list locks are taken
1896 * and this function is atomic with respect to other list locked calls.
1897 * A buffer cannot be placed on two lists at the same time.
1899 void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
)
1901 unsigned long flags
;
1903 spin_lock_irqsave(&list
->lock
, flags
);
1904 __skb_queue_after(list
, old
, newsk
);
1905 spin_unlock_irqrestore(&list
->lock
, flags
);
1910 * skb_insert - insert a buffer
1911 * @old: buffer to insert before
1912 * @newsk: buffer to insert
1913 * @list: list to use
1915 * Place a packet before a given packet in a list. The list locks are
1916 * taken and this function is atomic with respect to other list locked
1919 * A buffer cannot be placed on two lists at the same time.
1921 void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
)
1923 unsigned long flags
;
1925 spin_lock_irqsave(&list
->lock
, flags
);
1926 __skb_insert(newsk
, old
->prev
, old
, list
);
1927 spin_unlock_irqrestore(&list
->lock
, flags
);
1930 static inline void skb_split_inside_header(struct sk_buff
*skb
,
1931 struct sk_buff
* skb1
,
1932 const u32 len
, const int pos
)
1936 skb_copy_from_linear_data_offset(skb
, len
, skb_put(skb1
, pos
- len
),
1938 /* And move data appendix as is. */
1939 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++)
1940 skb_shinfo(skb1
)->frags
[i
] = skb_shinfo(skb
)->frags
[i
];
1942 skb_shinfo(skb1
)->nr_frags
= skb_shinfo(skb
)->nr_frags
;
1943 skb_shinfo(skb
)->nr_frags
= 0;
1944 skb1
->data_len
= skb
->data_len
;
1945 skb1
->len
+= skb1
->data_len
;
1948 skb_set_tail_pointer(skb
, len
);
1951 static inline void skb_split_no_header(struct sk_buff
*skb
,
1952 struct sk_buff
* skb1
,
1953 const u32 len
, int pos
)
1956 const int nfrags
= skb_shinfo(skb
)->nr_frags
;
1958 skb_shinfo(skb
)->nr_frags
= 0;
1959 skb1
->len
= skb1
->data_len
= skb
->len
- len
;
1961 skb
->data_len
= len
- pos
;
1963 for (i
= 0; i
< nfrags
; i
++) {
1964 int size
= skb_shinfo(skb
)->frags
[i
].size
;
1966 if (pos
+ size
> len
) {
1967 skb_shinfo(skb1
)->frags
[k
] = skb_shinfo(skb
)->frags
[i
];
1971 * We have two variants in this case:
1972 * 1. Move all the frag to the second
1973 * part, if it is possible. F.e.
1974 * this approach is mandatory for TUX,
1975 * where splitting is expensive.
1976 * 2. Split is accurately. We make this.
1978 get_page(skb_shinfo(skb
)->frags
[i
].page
);
1979 skb_shinfo(skb1
)->frags
[0].page_offset
+= len
- pos
;
1980 skb_shinfo(skb1
)->frags
[0].size
-= len
- pos
;
1981 skb_shinfo(skb
)->frags
[i
].size
= len
- pos
;
1982 skb_shinfo(skb
)->nr_frags
++;
1986 skb_shinfo(skb
)->nr_frags
++;
1989 skb_shinfo(skb1
)->nr_frags
= k
;
1993 * skb_split - Split fragmented skb to two parts at length len.
1994 * @skb: the buffer to split
1995 * @skb1: the buffer to receive the second part
1996 * @len: new length for skb
1998 void skb_split(struct sk_buff
*skb
, struct sk_buff
*skb1
, const u32 len
)
2000 int pos
= skb_headlen(skb
);
2002 if (len
< pos
) /* Split line is inside header. */
2003 skb_split_inside_header(skb
, skb1
, len
, pos
);
2004 else /* Second chunk has no header, nothing to copy. */
2005 skb_split_no_header(skb
, skb1
, len
, pos
);
2009 * skb_prepare_seq_read - Prepare a sequential read of skb data
2010 * @skb: the buffer to read
2011 * @from: lower offset of data to be read
2012 * @to: upper offset of data to be read
2013 * @st: state variable
2015 * Initializes the specified state variable. Must be called before
2016 * invoking skb_seq_read() for the first time.
2018 void skb_prepare_seq_read(struct sk_buff
*skb
, unsigned int from
,
2019 unsigned int to
, struct skb_seq_state
*st
)
2021 st
->lower_offset
= from
;
2022 st
->upper_offset
= to
;
2023 st
->root_skb
= st
->cur_skb
= skb
;
2024 st
->frag_idx
= st
->stepped_offset
= 0;
2025 st
->frag_data
= NULL
;
2029 * skb_seq_read - Sequentially read skb data
2030 * @consumed: number of bytes consumed by the caller so far
2031 * @data: destination pointer for data to be returned
2032 * @st: state variable
2034 * Reads a block of skb data at &consumed relative to the
2035 * lower offset specified to skb_prepare_seq_read(). Assigns
2036 * the head of the data block to &data and returns the length
2037 * of the block or 0 if the end of the skb data or the upper
2038 * offset has been reached.
2040 * The caller is not required to consume all of the data
2041 * returned, i.e. &consumed is typically set to the number
2042 * of bytes already consumed and the next call to
2043 * skb_seq_read() will return the remaining part of the block.
2045 * Note 1: The size of each block of data returned can be arbitary,
2046 * this limitation is the cost for zerocopy seqeuental
2047 * reads of potentially non linear data.
2049 * Note 2: Fragment lists within fragments are not implemented
2050 * at the moment, state->root_skb could be replaced with
2051 * a stack for this purpose.
2053 unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
2054 struct skb_seq_state
*st
)
2056 unsigned int block_limit
, abs_offset
= consumed
+ st
->lower_offset
;
2059 if (unlikely(abs_offset
>= st
->upper_offset
))
2063 block_limit
= skb_headlen(st
->cur_skb
);
2065 if (abs_offset
< block_limit
) {
2066 *data
= st
->cur_skb
->data
+ abs_offset
;
2067 return block_limit
- abs_offset
;
2070 if (st
->frag_idx
== 0 && !st
->frag_data
)
2071 st
->stepped_offset
+= skb_headlen(st
->cur_skb
);
2073 while (st
->frag_idx
< skb_shinfo(st
->cur_skb
)->nr_frags
) {
2074 frag
= &skb_shinfo(st
->cur_skb
)->frags
[st
->frag_idx
];
2075 block_limit
= frag
->size
+ st
->stepped_offset
;
2077 if (abs_offset
< block_limit
) {
2079 st
->frag_data
= kmap_skb_frag(frag
);
2081 *data
= (u8
*) st
->frag_data
+ frag
->page_offset
+
2082 (abs_offset
- st
->stepped_offset
);
2084 return block_limit
- abs_offset
;
2087 if (st
->frag_data
) {
2088 kunmap_skb_frag(st
->frag_data
);
2089 st
->frag_data
= NULL
;
2093 st
->stepped_offset
+= frag
->size
;
2096 if (st
->frag_data
) {
2097 kunmap_skb_frag(st
->frag_data
);
2098 st
->frag_data
= NULL
;
2101 if (st
->cur_skb
->next
) {
2102 st
->cur_skb
= st
->cur_skb
->next
;
2105 } else if (st
->root_skb
== st
->cur_skb
&&
2106 skb_shinfo(st
->root_skb
)->frag_list
) {
2107 st
->cur_skb
= skb_shinfo(st
->root_skb
)->frag_list
;
2115 * skb_abort_seq_read - Abort a sequential read of skb data
2116 * @st: state variable
2118 * Must be called if skb_seq_read() was not called until it
2121 void skb_abort_seq_read(struct skb_seq_state
*st
)
2124 kunmap_skb_frag(st
->frag_data
);
2127 #define TS_SKB_CB(state) ((struct skb_seq_state *) &((state)->cb))
2129 static unsigned int skb_ts_get_next_block(unsigned int offset
, const u8
**text
,
2130 struct ts_config
*conf
,
2131 struct ts_state
*state
)
2133 return skb_seq_read(offset
, text
, TS_SKB_CB(state
));
2136 static void skb_ts_finish(struct ts_config
*conf
, struct ts_state
*state
)
2138 skb_abort_seq_read(TS_SKB_CB(state
));
2142 * skb_find_text - Find a text pattern in skb data
2143 * @skb: the buffer to look in
2144 * @from: search offset
2146 * @config: textsearch configuration
2147 * @state: uninitialized textsearch state variable
2149 * Finds a pattern in the skb data according to the specified
2150 * textsearch configuration. Use textsearch_next() to retrieve
2151 * subsequent occurrences of the pattern. Returns the offset
2152 * to the first occurrence or UINT_MAX if no match was found.
2154 unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
2155 unsigned int to
, struct ts_config
*config
,
2156 struct ts_state
*state
)
2160 config
->get_next_block
= skb_ts_get_next_block
;
2161 config
->finish
= skb_ts_finish
;
2163 skb_prepare_seq_read(skb
, from
, to
, TS_SKB_CB(state
));
2165 ret
= textsearch_find(config
, state
);
2166 return (ret
<= to
- from
? ret
: UINT_MAX
);
2170 * skb_append_datato_frags: - append the user data to a skb
2171 * @sk: sock structure
2172 * @skb: skb structure to be appened with user data.
2173 * @getfrag: call back function to be used for getting the user data
2174 * @from: pointer to user message iov
2175 * @length: length of the iov message
2177 * Description: This procedure append the user data in the fragment part
2178 * of the skb if any page alloc fails user this procedure returns -ENOMEM
2180 int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
2181 int (*getfrag
)(void *from
, char *to
, int offset
,
2182 int len
, int odd
, struct sk_buff
*skb
),
2183 void *from
, int length
)
2186 skb_frag_t
*frag
= NULL
;
2187 struct page
*page
= NULL
;
2193 /* Return error if we don't have space for new frag */
2194 frg_cnt
= skb_shinfo(skb
)->nr_frags
;
2195 if (frg_cnt
>= MAX_SKB_FRAGS
)
2198 /* allocate a new page for next frag */
2199 page
= alloc_pages(sk
->sk_allocation
, 0);
2201 /* If alloc_page fails just return failure and caller will
2202 * free previous allocated pages by doing kfree_skb()
2207 /* initialize the next frag */
2208 sk
->sk_sndmsg_page
= page
;
2209 sk
->sk_sndmsg_off
= 0;
2210 skb_fill_page_desc(skb
, frg_cnt
, page
, 0, 0);
2211 skb
->truesize
+= PAGE_SIZE
;
2212 atomic_add(PAGE_SIZE
, &sk
->sk_wmem_alloc
);
2214 /* get the new initialized frag */
2215 frg_cnt
= skb_shinfo(skb
)->nr_frags
;
2216 frag
= &skb_shinfo(skb
)->frags
[frg_cnt
- 1];
2218 /* copy the user data to page */
2219 left
= PAGE_SIZE
- frag
->page_offset
;
2220 copy
= (length
> left
)? left
: length
;
2222 ret
= getfrag(from
, (page_address(frag
->page
) +
2223 frag
->page_offset
+ frag
->size
),
2224 offset
, copy
, 0, skb
);
2228 /* copy was successful so update the size parameters */
2229 sk
->sk_sndmsg_off
+= copy
;
2232 skb
->data_len
+= copy
;
2236 } while (length
> 0);
2242 * skb_pull_rcsum - pull skb and update receive checksum
2243 * @skb: buffer to update
2244 * @len: length of data pulled
2246 * This function performs an skb_pull on the packet and updates
2247 * the CHECKSUM_COMPLETE checksum. It should be used on
2248 * receive path processing instead of skb_pull unless you know
2249 * that the checksum difference is zero (e.g., a valid IP header)
2250 * or you are setting ip_summed to CHECKSUM_NONE.
2252 unsigned char *skb_pull_rcsum(struct sk_buff
*skb
, unsigned int len
)
2254 BUG_ON(len
> skb
->len
);
2256 BUG_ON(skb
->len
< skb
->data_len
);
2257 skb_postpull_rcsum(skb
, skb
->data
, len
);
2258 return skb
->data
+= len
;
2261 EXPORT_SYMBOL_GPL(skb_pull_rcsum
);
2264 * skb_segment - Perform protocol segmentation on skb.
2265 * @skb: buffer to segment
2266 * @features: features for the output path (see dev->features)
2268 * This function performs segmentation on the given skb. It returns
2269 * a pointer to the first in a list of new skbs for the segments.
2270 * In case of error it returns ERR_PTR(err).
2272 struct sk_buff
*skb_segment(struct sk_buff
*skb
, int features
)
2274 struct sk_buff
*segs
= NULL
;
2275 struct sk_buff
*tail
= NULL
;
2276 unsigned int mss
= skb_shinfo(skb
)->gso_size
;
2277 unsigned int doffset
= skb
->data
- skb_mac_header(skb
);
2278 unsigned int offset
= doffset
;
2279 unsigned int headroom
;
2281 int sg
= features
& NETIF_F_SG
;
2282 int nfrags
= skb_shinfo(skb
)->nr_frags
;
2287 __skb_push(skb
, doffset
);
2288 headroom
= skb_headroom(skb
);
2289 pos
= skb_headlen(skb
);
2292 struct sk_buff
*nskb
;
2298 len
= skb
->len
- offset
;
2302 hsize
= skb_headlen(skb
) - offset
;
2305 if (hsize
> len
|| !sg
)
2308 nskb
= alloc_skb(hsize
+ doffset
+ headroom
, GFP_ATOMIC
);
2309 if (unlikely(!nskb
))
2318 __copy_skb_header(nskb
, skb
);
2319 nskb
->mac_len
= skb
->mac_len
;
2321 skb_reserve(nskb
, headroom
);
2322 skb_reset_mac_header(nskb
);
2323 skb_set_network_header(nskb
, skb
->mac_len
);
2324 nskb
->transport_header
= (nskb
->network_header
+
2325 skb_network_header_len(skb
));
2326 skb_copy_from_linear_data(skb
, skb_put(nskb
, doffset
),
2329 nskb
->ip_summed
= CHECKSUM_NONE
;
2330 nskb
->csum
= skb_copy_and_csum_bits(skb
, offset
,
2336 frag
= skb_shinfo(nskb
)->frags
;
2339 skb_copy_from_linear_data_offset(skb
, offset
,
2340 skb_put(nskb
, hsize
), hsize
);
2342 while (pos
< offset
+ len
) {
2343 BUG_ON(i
>= nfrags
);
2345 *frag
= skb_shinfo(skb
)->frags
[i
];
2346 get_page(frag
->page
);
2350 frag
->page_offset
+= offset
- pos
;
2351 frag
->size
-= offset
- pos
;
2356 if (pos
+ size
<= offset
+ len
) {
2360 frag
->size
-= pos
+ size
- (offset
+ len
);
2367 skb_shinfo(nskb
)->nr_frags
= k
;
2368 nskb
->data_len
= len
- hsize
;
2369 nskb
->len
+= nskb
->data_len
;
2370 nskb
->truesize
+= nskb
->data_len
;
2371 } while ((offset
+= len
) < skb
->len
);
2376 while ((skb
= segs
)) {
2380 return ERR_PTR(err
);
2383 EXPORT_SYMBOL_GPL(skb_segment
);
2385 void __init
skb_init(void)
2387 skbuff_head_cache
= kmem_cache_create("skbuff_head_cache",
2388 sizeof(struct sk_buff
),
2390 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
,
2392 skbuff_fclone_cache
= kmem_cache_create("skbuff_fclone_cache",
2393 (2*sizeof(struct sk_buff
)) +
2396 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
,
2401 * skb_to_sgvec - Fill a scatter-gather list from a socket buffer
2402 * @skb: Socket buffer containing the buffers to be mapped
2403 * @sg: The scatter-gather list to map into
2404 * @offset: The offset into the buffer's contents to start mapping
2405 * @len: Length of buffer space to be mapped
2407 * Fill the specified scatter-gather list with mappings/pointers into a
2408 * region of the buffer space attached to a socket buffer.
2411 __skb_to_sgvec(struct sk_buff
*skb
, struct scatterlist
*sg
, int offset
, int len
)
2413 int start
= skb_headlen(skb
);
2414 int i
, copy
= start
- offset
;
2420 sg_set_buf(sg
, skb
->data
+ offset
, copy
);
2422 if ((len
-= copy
) == 0)
2427 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
2430 WARN_ON(start
> offset
+ len
);
2432 end
= start
+ skb_shinfo(skb
)->frags
[i
].size
;
2433 if ((copy
= end
- offset
) > 0) {
2434 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
2438 sg_set_page(&sg
[elt
], frag
->page
, copy
,
2439 frag
->page_offset
+offset
-start
);
2448 if (skb_shinfo(skb
)->frag_list
) {
2449 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
2451 for (; list
; list
= list
->next
) {
2454 WARN_ON(start
> offset
+ len
);
2456 end
= start
+ list
->len
;
2457 if ((copy
= end
- offset
) > 0) {
2460 elt
+= __skb_to_sgvec(list
, sg
+elt
, offset
- start
,
2462 if ((len
-= copy
) == 0)
2473 int skb_to_sgvec(struct sk_buff
*skb
, struct scatterlist
*sg
, int offset
, int len
)
2475 int nsg
= __skb_to_sgvec(skb
, sg
, offset
, len
);
2477 sg_mark_end(&sg
[nsg
- 1]);
2483 * skb_cow_data - Check that a socket buffer's data buffers are writable
2484 * @skb: The socket buffer to check.
2485 * @tailbits: Amount of trailing space to be added
2486 * @trailer: Returned pointer to the skb where the @tailbits space begins
2488 * Make sure that the data buffers attached to a socket buffer are
2489 * writable. If they are not, private copies are made of the data buffers
2490 * and the socket buffer is set to use these instead.
2492 * If @tailbits is given, make sure that there is space to write @tailbits
2493 * bytes of data beyond current end of socket buffer. @trailer will be
2494 * set to point to the skb in which this space begins.
2496 * The number of scatterlist elements required to completely map the
2497 * COW'd and extended socket buffer will be returned.
2499 int skb_cow_data(struct sk_buff
*skb
, int tailbits
, struct sk_buff
**trailer
)
2503 struct sk_buff
*skb1
, **skb_p
;
2505 /* If skb is cloned or its head is paged, reallocate
2506 * head pulling out all the pages (pages are considered not writable
2507 * at the moment even if they are anonymous).
2509 if ((skb_cloned(skb
) || skb_shinfo(skb
)->nr_frags
) &&
2510 __pskb_pull_tail(skb
, skb_pagelen(skb
)-skb_headlen(skb
)) == NULL
)
2513 /* Easy case. Most of packets will go this way. */
2514 if (!skb_shinfo(skb
)->frag_list
) {
2515 /* A little of trouble, not enough of space for trailer.
2516 * This should not happen, when stack is tuned to generate
2517 * good frames. OK, on miss we reallocate and reserve even more
2518 * space, 128 bytes is fair. */
2520 if (skb_tailroom(skb
) < tailbits
&&
2521 pskb_expand_head(skb
, 0, tailbits
-skb_tailroom(skb
)+128, GFP_ATOMIC
))
2529 /* Misery. We are in troubles, going to mincer fragments... */
2532 skb_p
= &skb_shinfo(skb
)->frag_list
;
2535 while ((skb1
= *skb_p
) != NULL
) {
2538 /* The fragment is partially pulled by someone,
2539 * this can happen on input. Copy it and everything
2542 if (skb_shared(skb1
))
2545 /* If the skb is the last, worry about trailer. */
2547 if (skb1
->next
== NULL
&& tailbits
) {
2548 if (skb_shinfo(skb1
)->nr_frags
||
2549 skb_shinfo(skb1
)->frag_list
||
2550 skb_tailroom(skb1
) < tailbits
)
2551 ntail
= tailbits
+ 128;
2557 skb_shinfo(skb1
)->nr_frags
||
2558 skb_shinfo(skb1
)->frag_list
) {
2559 struct sk_buff
*skb2
;
2561 /* Fuck, we are miserable poor guys... */
2563 skb2
= skb_copy(skb1
, GFP_ATOMIC
);
2565 skb2
= skb_copy_expand(skb1
,
2569 if (unlikely(skb2
== NULL
))
2573 skb_set_owner_w(skb2
, skb1
->sk
);
2575 /* Looking around. Are we still alive?
2576 * OK, link new skb, drop old one */
2578 skb2
->next
= skb1
->next
;
2585 skb_p
= &skb1
->next
;
2592 * skb_partial_csum_set - set up and verify partial csum values for packet
2593 * @skb: the skb to set
2594 * @start: the number of bytes after skb->data to start checksumming.
2595 * @off: the offset from start to place the checksum.
2597 * For untrusted partially-checksummed packets, we need to make sure the values
2598 * for skb->csum_start and skb->csum_offset are valid so we don't oops.
2600 * This function checks and sets those values and skb->ip_summed: if this
2601 * returns false you should drop the packet.
2603 bool skb_partial_csum_set(struct sk_buff
*skb
, u16 start
, u16 off
)
2605 if (unlikely(start
> skb
->len
- 2) ||
2606 unlikely((int)start
+ off
> skb
->len
- 2)) {
2607 if (net_ratelimit())
2609 "bad partial csum: csum=%u/%u len=%u\n",
2610 start
, off
, skb
->len
);
2613 skb
->ip_summed
= CHECKSUM_PARTIAL
;
2614 skb
->csum_start
= skb_headroom(skb
) + start
;
2615 skb
->csum_offset
= off
;
2619 void __skb_warn_lro_forwarding(const struct sk_buff
*skb
)
2621 if (net_ratelimit())
2622 pr_warning("%s: received packets cannot be forwarded"
2623 " while LRO is enabled\n", skb
->dev
->name
);
2626 EXPORT_SYMBOL(___pskb_trim
);
2627 EXPORT_SYMBOL(__kfree_skb
);
2628 EXPORT_SYMBOL(kfree_skb
);
2629 EXPORT_SYMBOL(__pskb_pull_tail
);
2630 EXPORT_SYMBOL(__alloc_skb
);
2631 EXPORT_SYMBOL(__netdev_alloc_skb
);
2632 EXPORT_SYMBOL(pskb_copy
);
2633 EXPORT_SYMBOL(pskb_expand_head
);
2634 EXPORT_SYMBOL(skb_checksum
);
2635 EXPORT_SYMBOL(skb_clone
);
2636 EXPORT_SYMBOL(skb_copy
);
2637 EXPORT_SYMBOL(skb_copy_and_csum_bits
);
2638 EXPORT_SYMBOL(skb_copy_and_csum_dev
);
2639 EXPORT_SYMBOL(skb_copy_bits
);
2640 EXPORT_SYMBOL(skb_copy_expand
);
2641 EXPORT_SYMBOL(skb_over_panic
);
2642 EXPORT_SYMBOL(skb_pad
);
2643 EXPORT_SYMBOL(skb_realloc_headroom
);
2644 EXPORT_SYMBOL(skb_under_panic
);
2645 EXPORT_SYMBOL(skb_dequeue
);
2646 EXPORT_SYMBOL(skb_dequeue_tail
);
2647 EXPORT_SYMBOL(skb_insert
);
2648 EXPORT_SYMBOL(skb_queue_purge
);
2649 EXPORT_SYMBOL(skb_queue_head
);
2650 EXPORT_SYMBOL(skb_queue_tail
);
2651 EXPORT_SYMBOL(skb_unlink
);
2652 EXPORT_SYMBOL(skb_append
);
2653 EXPORT_SYMBOL(skb_split
);
2654 EXPORT_SYMBOL(skb_prepare_seq_read
);
2655 EXPORT_SYMBOL(skb_seq_read
);
2656 EXPORT_SYMBOL(skb_abort_seq_read
);
2657 EXPORT_SYMBOL(skb_find_text
);
2658 EXPORT_SYMBOL(skb_append_datato_frags
);
2659 EXPORT_SYMBOL(__skb_warn_lro_forwarding
);
2661 EXPORT_SYMBOL_GPL(skb_to_sgvec
);
2662 EXPORT_SYMBOL_GPL(skb_cow_data
);
2663 EXPORT_SYMBOL_GPL(skb_partial_csum_set
);