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>
7 * Version: $Id: skbuff.c,v 1.90 2001/11/07 05:56:19 davem Exp $
10 * Alan Cox : Fixed the worst of the load
12 * Dave Platt : Interrupt stacking fix.
13 * Richard Kooijman : Timestamp fixes.
14 * Alan Cox : Changed buffer format.
15 * Alan Cox : destructor hook for AF_UNIX etc.
16 * Linus Torvalds : Better skb_clone.
17 * Alan Cox : Added skb_copy.
18 * Alan Cox : Added all the changed routines Linus
19 * only put in the headers
20 * Ray VanTassle : Fixed --skb->lock in free
21 * Alan Cox : skb_copy copy arp field
22 * Andi Kleen : slabified it.
23 * Robert Olsson : Removed skb_head_pool
26 * The __skb_ routines should be called with interrupts
27 * disabled, or you better be *real* sure that the operation is atomic
28 * with respect to whatever list is being frobbed (e.g. via lock_sock()
29 * or via disabling bottom half handlers, etc).
31 * This program is free software; you can redistribute it and/or
32 * modify it under the terms of the GNU General Public License
33 * as published by the Free Software Foundation; either version
34 * 2 of the License, or (at your option) any later version.
38 * The functions in this file will not compile correctly with gcc 2.4.x
41 #include <linux/config.h>
42 #include <linux/module.h>
43 #include <linux/types.h>
44 #include <linux/kernel.h>
45 #include <linux/sched.h>
47 #include <linux/interrupt.h>
49 #include <linux/inet.h>
50 #include <linux/slab.h>
51 #include <linux/netdevice.h>
52 #ifdef CONFIG_NET_CLS_ACT
53 #include <net/pkt_sched.h>
55 #include <linux/string.h>
56 #include <linux/skbuff.h>
57 #include <linux/cache.h>
58 #include <linux/rtnetlink.h>
59 #include <linux/init.h>
60 #include <linux/highmem.h>
62 #include <net/protocol.h>
65 #include <net/checksum.h>
68 #include <asm/uaccess.h>
69 #include <asm/system.h>
71 static kmem_cache_t
*skbuff_head_cache __read_mostly
;
72 static kmem_cache_t
*skbuff_fclone_cache __read_mostly
;
75 * Keep out-of-line to prevent kernel bloat.
76 * __builtin_return_address is not used because it is not always
81 * skb_over_panic - private function
86 * Out of line support code for skb_put(). Not user callable.
88 void skb_over_panic(struct sk_buff
*skb
, int sz
, void *here
)
90 printk(KERN_EMERG
"skb_over_panic: text:%p len:%d put:%d head:%p "
91 "data:%p tail:%p end:%p dev:%s\n",
92 here
, skb
->len
, sz
, skb
->head
, skb
->data
, skb
->tail
, skb
->end
,
93 skb
->dev
? skb
->dev
->name
: "<NULL>");
98 * skb_under_panic - private function
103 * Out of line support code for skb_push(). Not user callable.
106 void skb_under_panic(struct sk_buff
*skb
, int sz
, void *here
)
108 printk(KERN_EMERG
"skb_under_panic: text:%p len:%d put:%d head:%p "
109 "data:%p tail:%p end:%p dev:%s\n",
110 here
, skb
->len
, sz
, skb
->head
, skb
->data
, skb
->tail
, skb
->end
,
111 skb
->dev
? skb
->dev
->name
: "<NULL>");
115 /* Allocate a new skbuff. We do this ourselves so we can fill in a few
116 * 'private' fields and also do memory statistics to find all the
122 * __alloc_skb - allocate a network buffer
123 * @size: size to allocate
124 * @gfp_mask: allocation mask
125 * @fclone: allocate from fclone cache instead of head cache
126 * and allocate a cloned (child) skb
128 * Allocate a new &sk_buff. The returned buffer has no headroom and a
129 * tail room of size bytes. The object has a reference count of one.
130 * The return is the buffer. On a failure the return is %NULL.
132 * Buffers may only be allocated from interrupts using a @gfp_mask of
135 struct sk_buff
*__alloc_skb(unsigned int size
, gfp_t gfp_mask
,
139 struct skb_shared_info
*shinfo
;
143 cache
= fclone
? skbuff_fclone_cache
: skbuff_head_cache
;
146 skb
= kmem_cache_alloc(cache
, gfp_mask
& ~__GFP_DMA
);
150 /* Get the DATA. Size must match skb_add_mtu(). */
151 size
= SKB_DATA_ALIGN(size
);
152 data
= kmalloc(size
+ sizeof(struct skb_shared_info
), gfp_mask
);
156 memset(skb
, 0, offsetof(struct sk_buff
, truesize
));
157 skb
->truesize
= size
+ sizeof(struct sk_buff
);
158 atomic_set(&skb
->users
, 1);
162 skb
->end
= data
+ size
;
163 /* make sure we initialize shinfo sequentially */
164 shinfo
= skb_shinfo(skb
);
165 atomic_set(&shinfo
->dataref
, 1);
166 shinfo
->nr_frags
= 0;
167 shinfo
->tso_size
= 0;
168 shinfo
->tso_segs
= 0;
169 shinfo
->ufo_size
= 0;
170 shinfo
->ip6_frag_id
= 0;
171 shinfo
->frag_list
= NULL
;
174 struct sk_buff
*child
= skb
+ 1;
175 atomic_t
*fclone_ref
= (atomic_t
*) (child
+ 1);
177 skb
->fclone
= SKB_FCLONE_ORIG
;
178 atomic_set(fclone_ref
, 1);
180 child
->fclone
= SKB_FCLONE_UNAVAILABLE
;
185 kmem_cache_free(cache
, skb
);
191 * alloc_skb_from_cache - allocate a network buffer
192 * @cp: kmem_cache from which to allocate the data area
193 * (object size must be big enough for @size bytes + skb overheads)
194 * @size: size to allocate
195 * @gfp_mask: allocation mask
197 * Allocate a new &sk_buff. The returned buffer has no headroom and
198 * tail room of size bytes. The object has a reference count of one.
199 * The return is the buffer. On a failure the return is %NULL.
201 * Buffers may only be allocated from interrupts using a @gfp_mask of
204 struct sk_buff
*alloc_skb_from_cache(kmem_cache_t
*cp
,
212 skb
= kmem_cache_alloc(skbuff_head_cache
,
213 gfp_mask
& ~__GFP_DMA
);
218 size
= SKB_DATA_ALIGN(size
);
219 data
= kmem_cache_alloc(cp
, gfp_mask
);
223 memset(skb
, 0, offsetof(struct sk_buff
, truesize
));
224 skb
->truesize
= size
+ sizeof(struct sk_buff
);
225 atomic_set(&skb
->users
, 1);
229 skb
->end
= data
+ size
;
231 atomic_set(&(skb_shinfo(skb
)->dataref
), 1);
232 skb_shinfo(skb
)->nr_frags
= 0;
233 skb_shinfo(skb
)->tso_size
= 0;
234 skb_shinfo(skb
)->tso_segs
= 0;
235 skb_shinfo(skb
)->frag_list
= NULL
;
239 kmem_cache_free(skbuff_head_cache
, skb
);
245 static void skb_drop_fraglist(struct sk_buff
*skb
)
247 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
249 skb_shinfo(skb
)->frag_list
= NULL
;
252 struct sk_buff
*this = list
;
258 static void skb_clone_fraglist(struct sk_buff
*skb
)
260 struct sk_buff
*list
;
262 for (list
= skb_shinfo(skb
)->frag_list
; list
; list
= list
->next
)
266 void skb_release_data(struct sk_buff
*skb
)
269 !atomic_sub_return(skb
->nohdr
? (1 << SKB_DATAREF_SHIFT
) + 1 : 1,
270 &skb_shinfo(skb
)->dataref
)) {
271 if (skb_shinfo(skb
)->nr_frags
) {
273 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++)
274 put_page(skb_shinfo(skb
)->frags
[i
].page
);
277 if (skb_shinfo(skb
)->frag_list
)
278 skb_drop_fraglist(skb
);
285 * Free an skbuff by memory without cleaning the state.
287 void kfree_skbmem(struct sk_buff
*skb
)
289 struct sk_buff
*other
;
290 atomic_t
*fclone_ref
;
292 skb_release_data(skb
);
293 switch (skb
->fclone
) {
294 case SKB_FCLONE_UNAVAILABLE
:
295 kmem_cache_free(skbuff_head_cache
, skb
);
298 case SKB_FCLONE_ORIG
:
299 fclone_ref
= (atomic_t
*) (skb
+ 2);
300 if (atomic_dec_and_test(fclone_ref
))
301 kmem_cache_free(skbuff_fclone_cache
, skb
);
304 case SKB_FCLONE_CLONE
:
305 fclone_ref
= (atomic_t
*) (skb
+ 1);
308 /* The clone portion is available for
309 * fast-cloning again.
311 skb
->fclone
= SKB_FCLONE_UNAVAILABLE
;
313 if (atomic_dec_and_test(fclone_ref
))
314 kmem_cache_free(skbuff_fclone_cache
, other
);
320 * __kfree_skb - private function
323 * Free an sk_buff. Release anything attached to the buffer.
324 * Clean the state. This is an internal helper function. Users should
325 * always call kfree_skb
328 void __kfree_skb(struct sk_buff
*skb
)
330 dst_release(skb
->dst
);
332 secpath_put(skb
->sp
);
334 if (skb
->destructor
) {
336 skb
->destructor(skb
);
338 #ifdef CONFIG_NETFILTER
339 nf_conntrack_put(skb
->nfct
);
340 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
341 nf_conntrack_put_reasm(skb
->nfct_reasm
);
343 #ifdef CONFIG_BRIDGE_NETFILTER
344 nf_bridge_put(skb
->nf_bridge
);
347 /* XXX: IS this still necessary? - JHS */
348 #ifdef CONFIG_NET_SCHED
350 #ifdef CONFIG_NET_CLS_ACT
359 * skb_clone - duplicate an sk_buff
360 * @skb: buffer to clone
361 * @gfp_mask: allocation priority
363 * Duplicate an &sk_buff. The new one is not owned by a socket. Both
364 * copies share the same packet data but not structure. The new
365 * buffer has a reference count of 1. If the allocation fails the
366 * function returns %NULL otherwise the new buffer is returned.
368 * If this function is called from an interrupt gfp_mask() must be
372 struct sk_buff
*skb_clone(struct sk_buff
*skb
, gfp_t gfp_mask
)
377 if (skb
->fclone
== SKB_FCLONE_ORIG
&&
378 n
->fclone
== SKB_FCLONE_UNAVAILABLE
) {
379 atomic_t
*fclone_ref
= (atomic_t
*) (n
+ 1);
380 n
->fclone
= SKB_FCLONE_CLONE
;
381 atomic_inc(fclone_ref
);
383 n
= kmem_cache_alloc(skbuff_head_cache
, gfp_mask
);
386 n
->fclone
= SKB_FCLONE_UNAVAILABLE
;
389 #define C(x) n->x = skb->x
391 n
->next
= n
->prev
= NULL
;
402 secpath_get(skb
->sp
);
404 memcpy(n
->cb
, skb
->cb
, sizeof(skb
->cb
));
414 #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
418 n
->destructor
= NULL
;
419 #ifdef CONFIG_NETFILTER
422 nf_conntrack_get(skb
->nfct
);
424 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
426 nf_conntrack_get_reasm(skb
->nfct_reasm
);
428 #ifdef CONFIG_BRIDGE_NETFILTER
430 nf_bridge_get(skb
->nf_bridge
);
432 #endif /*CONFIG_NETFILTER*/
433 #ifdef CONFIG_NET_SCHED
435 #ifdef CONFIG_NET_CLS_ACT
436 n
->tc_verd
= SET_TC_VERD(skb
->tc_verd
,0);
437 n
->tc_verd
= CLR_TC_OK2MUNGE(n
->tc_verd
);
438 n
->tc_verd
= CLR_TC_MUNGED(n
->tc_verd
);
444 atomic_set(&n
->users
, 1);
450 atomic_inc(&(skb_shinfo(skb
)->dataref
));
456 static void copy_skb_header(struct sk_buff
*new, const struct sk_buff
*old
)
459 * Shift between the two data areas in bytes
461 unsigned long offset
= new->data
- old
->data
;
465 new->priority
= old
->priority
;
466 new->protocol
= old
->protocol
;
467 new->dst
= dst_clone(old
->dst
);
469 new->sp
= secpath_get(old
->sp
);
471 new->h
.raw
= old
->h
.raw
+ offset
;
472 new->nh
.raw
= old
->nh
.raw
+ offset
;
473 new->mac
.raw
= old
->mac
.raw
+ offset
;
474 memcpy(new->cb
, old
->cb
, sizeof(old
->cb
));
475 new->local_df
= old
->local_df
;
476 new->fclone
= SKB_FCLONE_UNAVAILABLE
;
477 new->pkt_type
= old
->pkt_type
;
478 new->tstamp
= old
->tstamp
;
479 new->destructor
= NULL
;
480 #ifdef CONFIG_NETFILTER
481 new->nfmark
= old
->nfmark
;
482 new->nfct
= old
->nfct
;
483 nf_conntrack_get(old
->nfct
);
484 new->nfctinfo
= old
->nfctinfo
;
485 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
486 new->nfct_reasm
= old
->nfct_reasm
;
487 nf_conntrack_get_reasm(old
->nfct_reasm
);
489 #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
490 new->ipvs_property
= old
->ipvs_property
;
492 #ifdef CONFIG_BRIDGE_NETFILTER
493 new->nf_bridge
= old
->nf_bridge
;
494 nf_bridge_get(old
->nf_bridge
);
497 #ifdef CONFIG_NET_SCHED
498 #ifdef CONFIG_NET_CLS_ACT
499 new->tc_verd
= old
->tc_verd
;
501 new->tc_index
= old
->tc_index
;
503 atomic_set(&new->users
, 1);
504 skb_shinfo(new)->tso_size
= skb_shinfo(old
)->tso_size
;
505 skb_shinfo(new)->tso_segs
= skb_shinfo(old
)->tso_segs
;
509 * skb_copy - create private copy of an sk_buff
510 * @skb: buffer to copy
511 * @gfp_mask: allocation priority
513 * Make a copy of both an &sk_buff and its data. This is used when the
514 * caller wishes to modify the data and needs a private copy of the
515 * data to alter. Returns %NULL on failure or the pointer to the buffer
516 * on success. The returned buffer has a reference count of 1.
518 * As by-product this function converts non-linear &sk_buff to linear
519 * one, so that &sk_buff becomes completely private and caller is allowed
520 * to modify all the data of returned buffer. This means that this
521 * function is not recommended for use in circumstances when only
522 * header is going to be modified. Use pskb_copy() instead.
525 struct sk_buff
*skb_copy(const struct sk_buff
*skb
, gfp_t gfp_mask
)
527 int headerlen
= skb
->data
- skb
->head
;
529 * Allocate the copy buffer
531 struct sk_buff
*n
= alloc_skb(skb
->end
- skb
->head
+ skb
->data_len
,
536 /* Set the data pointer */
537 skb_reserve(n
, headerlen
);
538 /* Set the tail pointer and length */
539 skb_put(n
, skb
->len
);
541 n
->ip_summed
= skb
->ip_summed
;
543 if (skb_copy_bits(skb
, -headerlen
, n
->head
, headerlen
+ skb
->len
))
546 copy_skb_header(n
, skb
);
552 * pskb_copy - create copy of an sk_buff with private head.
553 * @skb: buffer to copy
554 * @gfp_mask: allocation priority
556 * Make a copy of both an &sk_buff and part of its data, located
557 * in header. Fragmented data remain shared. This is used when
558 * the caller wishes to modify only header of &sk_buff and needs
559 * private copy of the header to alter. Returns %NULL on failure
560 * or the pointer to the buffer on success.
561 * The returned buffer has a reference count of 1.
564 struct sk_buff
*pskb_copy(struct sk_buff
*skb
, gfp_t gfp_mask
)
567 * Allocate the copy buffer
569 struct sk_buff
*n
= alloc_skb(skb
->end
- skb
->head
, gfp_mask
);
574 /* Set the data pointer */
575 skb_reserve(n
, skb
->data
- skb
->head
);
576 /* Set the tail pointer and length */
577 skb_put(n
, skb_headlen(skb
));
579 memcpy(n
->data
, skb
->data
, n
->len
);
581 n
->ip_summed
= skb
->ip_summed
;
583 n
->data_len
= skb
->data_len
;
586 if (skb_shinfo(skb
)->nr_frags
) {
589 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
590 skb_shinfo(n
)->frags
[i
] = skb_shinfo(skb
)->frags
[i
];
591 get_page(skb_shinfo(n
)->frags
[i
].page
);
593 skb_shinfo(n
)->nr_frags
= i
;
596 if (skb_shinfo(skb
)->frag_list
) {
597 skb_shinfo(n
)->frag_list
= skb_shinfo(skb
)->frag_list
;
598 skb_clone_fraglist(n
);
601 copy_skb_header(n
, skb
);
607 * pskb_expand_head - reallocate header of &sk_buff
608 * @skb: buffer to reallocate
609 * @nhead: room to add at head
610 * @ntail: room to add at tail
611 * @gfp_mask: allocation priority
613 * Expands (or creates identical copy, if &nhead and &ntail are zero)
614 * header of skb. &sk_buff itself is not changed. &sk_buff MUST have
615 * reference count of 1. Returns zero in the case of success or error,
616 * if expansion failed. In the last case, &sk_buff is not changed.
618 * All the pointers pointing into skb header may change and must be
619 * reloaded after call to this function.
622 int pskb_expand_head(struct sk_buff
*skb
, int nhead
, int ntail
,
627 int size
= nhead
+ (skb
->end
- skb
->head
) + ntail
;
633 size
= SKB_DATA_ALIGN(size
);
635 data
= kmalloc(size
+ sizeof(struct skb_shared_info
), gfp_mask
);
639 /* Copy only real data... and, alas, header. This should be
640 * optimized for the cases when header is void. */
641 memcpy(data
+ nhead
, skb
->head
, skb
->tail
- skb
->head
);
642 memcpy(data
+ size
, skb
->end
, sizeof(struct skb_shared_info
));
644 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++)
645 get_page(skb_shinfo(skb
)->frags
[i
].page
);
647 if (skb_shinfo(skb
)->frag_list
)
648 skb_clone_fraglist(skb
);
650 skb_release_data(skb
);
652 off
= (data
+ nhead
) - skb
->head
;
655 skb
->end
= data
+ size
;
663 atomic_set(&skb_shinfo(skb
)->dataref
, 1);
670 /* Make private copy of skb with writable head and some headroom */
672 struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
, unsigned int headroom
)
674 struct sk_buff
*skb2
;
675 int delta
= headroom
- skb_headroom(skb
);
678 skb2
= pskb_copy(skb
, GFP_ATOMIC
);
680 skb2
= skb_clone(skb
, GFP_ATOMIC
);
681 if (skb2
&& pskb_expand_head(skb2
, SKB_DATA_ALIGN(delta
), 0,
692 * skb_copy_expand - copy and expand sk_buff
693 * @skb: buffer to copy
694 * @newheadroom: new free bytes at head
695 * @newtailroom: new free bytes at tail
696 * @gfp_mask: allocation priority
698 * Make a copy of both an &sk_buff and its data and while doing so
699 * allocate additional space.
701 * This is used when the caller wishes to modify the data and needs a
702 * private copy of the data to alter as well as more space for new fields.
703 * Returns %NULL on failure or the pointer to the buffer
704 * on success. The returned buffer has a reference count of 1.
706 * You must pass %GFP_ATOMIC as the allocation priority if this function
707 * is called from an interrupt.
709 * BUG ALERT: ip_summed is not copied. Why does this work? Is it used
710 * only by netfilter in the cases when checksum is recalculated? --ANK
712 struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
713 int newheadroom
, int newtailroom
,
717 * Allocate the copy buffer
719 struct sk_buff
*n
= alloc_skb(newheadroom
+ skb
->len
+ newtailroom
,
721 int head_copy_len
, head_copy_off
;
726 skb_reserve(n
, newheadroom
);
728 /* Set the tail pointer and length */
729 skb_put(n
, skb
->len
);
731 head_copy_len
= skb_headroom(skb
);
733 if (newheadroom
<= head_copy_len
)
734 head_copy_len
= newheadroom
;
736 head_copy_off
= newheadroom
- head_copy_len
;
738 /* Copy the linear header and data. */
739 if (skb_copy_bits(skb
, -head_copy_len
, n
->head
+ head_copy_off
,
740 skb
->len
+ head_copy_len
))
743 copy_skb_header(n
, skb
);
749 * skb_pad - zero pad the tail of an skb
750 * @skb: buffer to pad
753 * Ensure that a buffer is followed by a padding area that is zero
754 * filled. Used by network drivers which may DMA or transfer data
755 * beyond the buffer end onto the wire.
757 * May return NULL in out of memory cases.
760 struct sk_buff
*skb_pad(struct sk_buff
*skb
, int pad
)
762 struct sk_buff
*nskb
;
764 /* If the skbuff is non linear tailroom is always zero.. */
765 if (skb_tailroom(skb
) >= pad
) {
766 memset(skb
->data
+skb
->len
, 0, pad
);
770 nskb
= skb_copy_expand(skb
, skb_headroom(skb
), skb_tailroom(skb
) + pad
, GFP_ATOMIC
);
773 memset(nskb
->data
+nskb
->len
, 0, pad
);
777 /* Trims skb to length len. It can change skb pointers, if "realloc" is 1.
778 * If realloc==0 and trimming is impossible without change of data,
782 int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
, int realloc
)
784 int offset
= skb_headlen(skb
);
785 int nfrags
= skb_shinfo(skb
)->nr_frags
;
788 for (i
= 0; i
< nfrags
; i
++) {
789 int end
= offset
+ skb_shinfo(skb
)->frags
[i
].size
;
791 if (skb_cloned(skb
)) {
793 if (pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
))
797 put_page(skb_shinfo(skb
)->frags
[i
].page
);
798 skb_shinfo(skb
)->nr_frags
--;
800 skb_shinfo(skb
)->frags
[i
].size
= len
- offset
;
807 skb
->data_len
-= skb
->len
- len
;
810 if (len
<= skb_headlen(skb
)) {
813 skb
->tail
= skb
->data
+ len
;
814 if (skb_shinfo(skb
)->frag_list
&& !skb_cloned(skb
))
815 skb_drop_fraglist(skb
);
817 skb
->data_len
-= skb
->len
- len
;
826 * __pskb_pull_tail - advance tail of skb header
827 * @skb: buffer to reallocate
828 * @delta: number of bytes to advance tail
830 * The function makes a sense only on a fragmented &sk_buff,
831 * it expands header moving its tail forward and copying necessary
832 * data from fragmented part.
834 * &sk_buff MUST have reference count of 1.
836 * Returns %NULL (and &sk_buff does not change) if pull failed
837 * or value of new tail of skb in the case of success.
839 * All the pointers pointing into skb header may change and must be
840 * reloaded after call to this function.
843 /* Moves tail of skb head forward, copying data from fragmented part,
844 * when it is necessary.
845 * 1. It may fail due to malloc failure.
846 * 2. It may change skb pointers.
848 * It is pretty complicated. Luckily, it is called only in exceptional cases.
850 unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
)
852 /* If skb has not enough free space at tail, get new one
853 * plus 128 bytes for future expansions. If we have enough
854 * room at tail, reallocate without expansion only if skb is cloned.
856 int i
, k
, eat
= (skb
->tail
+ delta
) - skb
->end
;
858 if (eat
> 0 || skb_cloned(skb
)) {
859 if (pskb_expand_head(skb
, 0, eat
> 0 ? eat
+ 128 : 0,
864 if (skb_copy_bits(skb
, skb_headlen(skb
), skb
->tail
, delta
))
867 /* Optimization: no fragments, no reasons to preestimate
868 * size of pulled pages. Superb.
870 if (!skb_shinfo(skb
)->frag_list
)
873 /* Estimate size of pulled pages. */
875 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
876 if (skb_shinfo(skb
)->frags
[i
].size
>= eat
)
878 eat
-= skb_shinfo(skb
)->frags
[i
].size
;
881 /* If we need update frag list, we are in troubles.
882 * Certainly, it possible to add an offset to skb data,
883 * but taking into account that pulling is expected to
884 * be very rare operation, it is worth to fight against
885 * further bloating skb head and crucify ourselves here instead.
886 * Pure masohism, indeed. 8)8)
889 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
890 struct sk_buff
*clone
= NULL
;
891 struct sk_buff
*insp
= NULL
;
896 if (list
->len
<= eat
) {
897 /* Eaten as whole. */
902 /* Eaten partially. */
904 if (skb_shared(list
)) {
905 /* Sucks! We need to fork list. :-( */
906 clone
= skb_clone(list
, GFP_ATOMIC
);
912 /* This may be pulled without
916 if (!pskb_pull(list
, eat
)) {
925 /* Free pulled out fragments. */
926 while ((list
= skb_shinfo(skb
)->frag_list
) != insp
) {
927 skb_shinfo(skb
)->frag_list
= list
->next
;
930 /* And insert new clone at head. */
933 skb_shinfo(skb
)->frag_list
= clone
;
936 /* Success! Now we may commit changes to skb data. */
941 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
942 if (skb_shinfo(skb
)->frags
[i
].size
<= eat
) {
943 put_page(skb_shinfo(skb
)->frags
[i
].page
);
944 eat
-= skb_shinfo(skb
)->frags
[i
].size
;
946 skb_shinfo(skb
)->frags
[k
] = skb_shinfo(skb
)->frags
[i
];
948 skb_shinfo(skb
)->frags
[k
].page_offset
+= eat
;
949 skb_shinfo(skb
)->frags
[k
].size
-= eat
;
955 skb_shinfo(skb
)->nr_frags
= k
;
958 skb
->data_len
-= delta
;
963 /* Copy some data bits from skb to kernel buffer. */
965 int skb_copy_bits(const struct sk_buff
*skb
, int offset
, void *to
, int len
)
968 int start
= skb_headlen(skb
);
970 if (offset
> (int)skb
->len
- len
)
974 if ((copy
= start
- offset
) > 0) {
977 memcpy(to
, skb
->data
+ offset
, copy
);
978 if ((len
-= copy
) == 0)
984 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
987 BUG_TRAP(start
<= offset
+ len
);
989 end
= start
+ skb_shinfo(skb
)->frags
[i
].size
;
990 if ((copy
= end
- offset
) > 0) {
996 vaddr
= kmap_skb_frag(&skb_shinfo(skb
)->frags
[i
]);
998 vaddr
+ skb_shinfo(skb
)->frags
[i
].page_offset
+
999 offset
- start
, copy
);
1000 kunmap_skb_frag(vaddr
);
1002 if ((len
-= copy
) == 0)
1010 if (skb_shinfo(skb
)->frag_list
) {
1011 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1013 for (; list
; list
= list
->next
) {
1016 BUG_TRAP(start
<= offset
+ len
);
1018 end
= start
+ list
->len
;
1019 if ((copy
= end
- offset
) > 0) {
1022 if (skb_copy_bits(list
, offset
- start
,
1025 if ((len
-= copy
) == 0)
1041 * skb_store_bits - store bits from kernel buffer to skb
1042 * @skb: destination buffer
1043 * @offset: offset in destination
1044 * @from: source buffer
1045 * @len: number of bytes to copy
1047 * Copy the specified number of bytes from the source buffer to the
1048 * destination skb. This function handles all the messy bits of
1049 * traversing fragment lists and such.
1052 int skb_store_bits(const struct sk_buff
*skb
, int offset
, void *from
, int len
)
1055 int start
= skb_headlen(skb
);
1057 if (offset
> (int)skb
->len
- len
)
1060 if ((copy
= start
- offset
) > 0) {
1063 memcpy(skb
->data
+ offset
, from
, copy
);
1064 if ((len
-= copy
) == 0)
1070 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1071 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1074 BUG_TRAP(start
<= offset
+ len
);
1076 end
= start
+ frag
->size
;
1077 if ((copy
= end
- offset
) > 0) {
1083 vaddr
= kmap_skb_frag(frag
);
1084 memcpy(vaddr
+ frag
->page_offset
+ offset
- start
,
1086 kunmap_skb_frag(vaddr
);
1088 if ((len
-= copy
) == 0)
1096 if (skb_shinfo(skb
)->frag_list
) {
1097 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1099 for (; list
; list
= list
->next
) {
1102 BUG_TRAP(start
<= offset
+ len
);
1104 end
= start
+ list
->len
;
1105 if ((copy
= end
- offset
) > 0) {
1108 if (skb_store_bits(list
, offset
- start
,
1111 if ((len
-= copy
) == 0)
1126 EXPORT_SYMBOL(skb_store_bits
);
1128 /* Checksum skb data. */
1130 unsigned int skb_checksum(const struct sk_buff
*skb
, int offset
,
1131 int len
, unsigned int csum
)
1133 int start
= skb_headlen(skb
);
1134 int i
, copy
= start
- offset
;
1137 /* Checksum header. */
1141 csum
= csum_partial(skb
->data
+ offset
, copy
, csum
);
1142 if ((len
-= copy
) == 0)
1148 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1151 BUG_TRAP(start
<= offset
+ len
);
1153 end
= start
+ skb_shinfo(skb
)->frags
[i
].size
;
1154 if ((copy
= end
- offset
) > 0) {
1157 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1161 vaddr
= kmap_skb_frag(frag
);
1162 csum2
= csum_partial(vaddr
+ frag
->page_offset
+
1163 offset
- start
, copy
, 0);
1164 kunmap_skb_frag(vaddr
);
1165 csum
= csum_block_add(csum
, csum2
, pos
);
1174 if (skb_shinfo(skb
)->frag_list
) {
1175 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1177 for (; list
; list
= list
->next
) {
1180 BUG_TRAP(start
<= offset
+ len
);
1182 end
= start
+ list
->len
;
1183 if ((copy
= end
- offset
) > 0) {
1187 csum2
= skb_checksum(list
, offset
- start
,
1189 csum
= csum_block_add(csum
, csum2
, pos
);
1190 if ((len
-= copy
) == 0)
1203 /* Both of above in one bottle. */
1205 unsigned int skb_copy_and_csum_bits(const struct sk_buff
*skb
, int offset
,
1206 u8
*to
, int len
, unsigned int csum
)
1208 int start
= skb_headlen(skb
);
1209 int i
, copy
= start
- offset
;
1216 csum
= csum_partial_copy_nocheck(skb
->data
+ offset
, to
,
1218 if ((len
-= copy
) == 0)
1225 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1228 BUG_TRAP(start
<= offset
+ len
);
1230 end
= start
+ skb_shinfo(skb
)->frags
[i
].size
;
1231 if ((copy
= end
- offset
) > 0) {
1234 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1238 vaddr
= kmap_skb_frag(frag
);
1239 csum2
= csum_partial_copy_nocheck(vaddr
+
1243 kunmap_skb_frag(vaddr
);
1244 csum
= csum_block_add(csum
, csum2
, pos
);
1254 if (skb_shinfo(skb
)->frag_list
) {
1255 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1257 for (; list
; list
= list
->next
) {
1261 BUG_TRAP(start
<= offset
+ len
);
1263 end
= start
+ list
->len
;
1264 if ((copy
= end
- offset
) > 0) {
1267 csum2
= skb_copy_and_csum_bits(list
,
1270 csum
= csum_block_add(csum
, csum2
, pos
);
1271 if ((len
-= copy
) == 0)
1284 void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
)
1289 if (skb
->ip_summed
== CHECKSUM_HW
)
1290 csstart
= skb
->h
.raw
- skb
->data
;
1292 csstart
= skb_headlen(skb
);
1294 BUG_ON(csstart
> skb_headlen(skb
));
1296 memcpy(to
, skb
->data
, csstart
);
1299 if (csstart
!= skb
->len
)
1300 csum
= skb_copy_and_csum_bits(skb
, csstart
, to
+ csstart
,
1301 skb
->len
- csstart
, 0);
1303 if (skb
->ip_summed
== CHECKSUM_HW
) {
1304 long csstuff
= csstart
+ skb
->csum
;
1306 *((unsigned short *)(to
+ csstuff
)) = csum_fold(csum
);
1311 * skb_dequeue - remove from the head of the queue
1312 * @list: list to dequeue from
1314 * Remove the head of the list. The list lock is taken so the function
1315 * may be used safely with other locking list functions. The head item is
1316 * returned or %NULL if the list is empty.
1319 struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
)
1321 unsigned long flags
;
1322 struct sk_buff
*result
;
1324 spin_lock_irqsave(&list
->lock
, flags
);
1325 result
= __skb_dequeue(list
);
1326 spin_unlock_irqrestore(&list
->lock
, flags
);
1331 * skb_dequeue_tail - remove from the tail of the queue
1332 * @list: list to dequeue from
1334 * Remove the tail of the list. The list lock is taken so the function
1335 * may be used safely with other locking list functions. The tail item is
1336 * returned or %NULL if the list is empty.
1338 struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
)
1340 unsigned long flags
;
1341 struct sk_buff
*result
;
1343 spin_lock_irqsave(&list
->lock
, flags
);
1344 result
= __skb_dequeue_tail(list
);
1345 spin_unlock_irqrestore(&list
->lock
, flags
);
1350 * skb_queue_purge - empty a list
1351 * @list: list to empty
1353 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1354 * the list and one reference dropped. This function takes the list
1355 * lock and is atomic with respect to other list locking functions.
1357 void skb_queue_purge(struct sk_buff_head
*list
)
1359 struct sk_buff
*skb
;
1360 while ((skb
= skb_dequeue(list
)) != NULL
)
1365 * skb_queue_head - queue a buffer at the list head
1366 * @list: list to use
1367 * @newsk: buffer to queue
1369 * Queue a buffer at the start of the list. This function takes the
1370 * list lock and can be used safely with other locking &sk_buff functions
1373 * A buffer cannot be placed on two lists at the same time.
1375 void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
)
1377 unsigned long flags
;
1379 spin_lock_irqsave(&list
->lock
, flags
);
1380 __skb_queue_head(list
, newsk
);
1381 spin_unlock_irqrestore(&list
->lock
, flags
);
1385 * skb_queue_tail - queue a buffer at the list tail
1386 * @list: list to use
1387 * @newsk: buffer to queue
1389 * Queue a buffer at the tail of the list. This function takes the
1390 * list lock and can be used safely with other locking &sk_buff functions
1393 * A buffer cannot be placed on two lists at the same time.
1395 void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
)
1397 unsigned long flags
;
1399 spin_lock_irqsave(&list
->lock
, flags
);
1400 __skb_queue_tail(list
, newsk
);
1401 spin_unlock_irqrestore(&list
->lock
, flags
);
1405 * skb_unlink - remove a buffer from a list
1406 * @skb: buffer to remove
1407 * @list: list to use
1409 * Remove a packet from a list. The list locks are taken and this
1410 * function is atomic with respect to other list locked calls
1412 * You must know what list the SKB is on.
1414 void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1416 unsigned long flags
;
1418 spin_lock_irqsave(&list
->lock
, flags
);
1419 __skb_unlink(skb
, list
);
1420 spin_unlock_irqrestore(&list
->lock
, flags
);
1424 * skb_append - append a buffer
1425 * @old: buffer to insert after
1426 * @newsk: buffer to insert
1427 * @list: list to use
1429 * Place a packet after a given packet in a list. The list locks are taken
1430 * and this function is atomic with respect to other list locked calls.
1431 * A buffer cannot be placed on two lists at the same time.
1433 void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
)
1435 unsigned long flags
;
1437 spin_lock_irqsave(&list
->lock
, flags
);
1438 __skb_append(old
, newsk
, list
);
1439 spin_unlock_irqrestore(&list
->lock
, flags
);
1444 * skb_insert - insert a buffer
1445 * @old: buffer to insert before
1446 * @newsk: buffer to insert
1447 * @list: list to use
1449 * Place a packet before a given packet in a list. The list locks are
1450 * taken and this function is atomic with respect to other list locked
1453 * A buffer cannot be placed on two lists at the same time.
1455 void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
)
1457 unsigned long flags
;
1459 spin_lock_irqsave(&list
->lock
, flags
);
1460 __skb_insert(newsk
, old
->prev
, old
, list
);
1461 spin_unlock_irqrestore(&list
->lock
, flags
);
1466 * Tune the memory allocator for a new MTU size.
1468 void skb_add_mtu(int mtu
)
1470 /* Must match allocation in alloc_skb */
1471 mtu
= SKB_DATA_ALIGN(mtu
) + sizeof(struct skb_shared_info
);
1473 kmem_add_cache_size(mtu
);
1477 static inline void skb_split_inside_header(struct sk_buff
*skb
,
1478 struct sk_buff
* skb1
,
1479 const u32 len
, const int pos
)
1483 memcpy(skb_put(skb1
, pos
- len
), skb
->data
+ len
, pos
- len
);
1485 /* And move data appendix as is. */
1486 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++)
1487 skb_shinfo(skb1
)->frags
[i
] = skb_shinfo(skb
)->frags
[i
];
1489 skb_shinfo(skb1
)->nr_frags
= skb_shinfo(skb
)->nr_frags
;
1490 skb_shinfo(skb
)->nr_frags
= 0;
1491 skb1
->data_len
= skb
->data_len
;
1492 skb1
->len
+= skb1
->data_len
;
1495 skb
->tail
= skb
->data
+ len
;
1498 static inline void skb_split_no_header(struct sk_buff
*skb
,
1499 struct sk_buff
* skb1
,
1500 const u32 len
, int pos
)
1503 const int nfrags
= skb_shinfo(skb
)->nr_frags
;
1505 skb_shinfo(skb
)->nr_frags
= 0;
1506 skb1
->len
= skb1
->data_len
= skb
->len
- len
;
1508 skb
->data_len
= len
- pos
;
1510 for (i
= 0; i
< nfrags
; i
++) {
1511 int size
= skb_shinfo(skb
)->frags
[i
].size
;
1513 if (pos
+ size
> len
) {
1514 skb_shinfo(skb1
)->frags
[k
] = skb_shinfo(skb
)->frags
[i
];
1518 * We have two variants in this case:
1519 * 1. Move all the frag to the second
1520 * part, if it is possible. F.e.
1521 * this approach is mandatory for TUX,
1522 * where splitting is expensive.
1523 * 2. Split is accurately. We make this.
1525 get_page(skb_shinfo(skb
)->frags
[i
].page
);
1526 skb_shinfo(skb1
)->frags
[0].page_offset
+= len
- pos
;
1527 skb_shinfo(skb1
)->frags
[0].size
-= len
- pos
;
1528 skb_shinfo(skb
)->frags
[i
].size
= len
- pos
;
1529 skb_shinfo(skb
)->nr_frags
++;
1533 skb_shinfo(skb
)->nr_frags
++;
1536 skb_shinfo(skb1
)->nr_frags
= k
;
1540 * skb_split - Split fragmented skb to two parts at length len.
1541 * @skb: the buffer to split
1542 * @skb1: the buffer to receive the second part
1543 * @len: new length for skb
1545 void skb_split(struct sk_buff
*skb
, struct sk_buff
*skb1
, const u32 len
)
1547 int pos
= skb_headlen(skb
);
1549 if (len
< pos
) /* Split line is inside header. */
1550 skb_split_inside_header(skb
, skb1
, len
, pos
);
1551 else /* Second chunk has no header, nothing to copy. */
1552 skb_split_no_header(skb
, skb1
, len
, pos
);
1556 * skb_prepare_seq_read - Prepare a sequential read of skb data
1557 * @skb: the buffer to read
1558 * @from: lower offset of data to be read
1559 * @to: upper offset of data to be read
1560 * @st: state variable
1562 * Initializes the specified state variable. Must be called before
1563 * invoking skb_seq_read() for the first time.
1565 void skb_prepare_seq_read(struct sk_buff
*skb
, unsigned int from
,
1566 unsigned int to
, struct skb_seq_state
*st
)
1568 st
->lower_offset
= from
;
1569 st
->upper_offset
= to
;
1570 st
->root_skb
= st
->cur_skb
= skb
;
1571 st
->frag_idx
= st
->stepped_offset
= 0;
1572 st
->frag_data
= NULL
;
1576 * skb_seq_read - Sequentially read skb data
1577 * @consumed: number of bytes consumed by the caller so far
1578 * @data: destination pointer for data to be returned
1579 * @st: state variable
1581 * Reads a block of skb data at &consumed relative to the
1582 * lower offset specified to skb_prepare_seq_read(). Assigns
1583 * the head of the data block to &data and returns the length
1584 * of the block or 0 if the end of the skb data or the upper
1585 * offset has been reached.
1587 * The caller is not required to consume all of the data
1588 * returned, i.e. &consumed is typically set to the number
1589 * of bytes already consumed and the next call to
1590 * skb_seq_read() will return the remaining part of the block.
1592 * Note: The size of each block of data returned can be arbitary,
1593 * this limitation is the cost for zerocopy seqeuental
1594 * reads of potentially non linear data.
1596 * Note: Fragment lists within fragments are not implemented
1597 * at the moment, state->root_skb could be replaced with
1598 * a stack for this purpose.
1600 unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
1601 struct skb_seq_state
*st
)
1603 unsigned int block_limit
, abs_offset
= consumed
+ st
->lower_offset
;
1606 if (unlikely(abs_offset
>= st
->upper_offset
))
1610 block_limit
= skb_headlen(st
->cur_skb
);
1612 if (abs_offset
< block_limit
) {
1613 *data
= st
->cur_skb
->data
+ abs_offset
;
1614 return block_limit
- abs_offset
;
1617 if (st
->frag_idx
== 0 && !st
->frag_data
)
1618 st
->stepped_offset
+= skb_headlen(st
->cur_skb
);
1620 while (st
->frag_idx
< skb_shinfo(st
->cur_skb
)->nr_frags
) {
1621 frag
= &skb_shinfo(st
->cur_skb
)->frags
[st
->frag_idx
];
1622 block_limit
= frag
->size
+ st
->stepped_offset
;
1624 if (abs_offset
< block_limit
) {
1626 st
->frag_data
= kmap_skb_frag(frag
);
1628 *data
= (u8
*) st
->frag_data
+ frag
->page_offset
+
1629 (abs_offset
- st
->stepped_offset
);
1631 return block_limit
- abs_offset
;
1634 if (st
->frag_data
) {
1635 kunmap_skb_frag(st
->frag_data
);
1636 st
->frag_data
= NULL
;
1640 st
->stepped_offset
+= frag
->size
;
1643 if (st
->cur_skb
->next
) {
1644 st
->cur_skb
= st
->cur_skb
->next
;
1647 } else if (st
->root_skb
== st
->cur_skb
&&
1648 skb_shinfo(st
->root_skb
)->frag_list
) {
1649 st
->cur_skb
= skb_shinfo(st
->root_skb
)->frag_list
;
1657 * skb_abort_seq_read - Abort a sequential read of skb data
1658 * @st: state variable
1660 * Must be called if skb_seq_read() was not called until it
1663 void skb_abort_seq_read(struct skb_seq_state
*st
)
1666 kunmap_skb_frag(st
->frag_data
);
1669 #define TS_SKB_CB(state) ((struct skb_seq_state *) &((state)->cb))
1671 static unsigned int skb_ts_get_next_block(unsigned int offset
, const u8
**text
,
1672 struct ts_config
*conf
,
1673 struct ts_state
*state
)
1675 return skb_seq_read(offset
, text
, TS_SKB_CB(state
));
1678 static void skb_ts_finish(struct ts_config
*conf
, struct ts_state
*state
)
1680 skb_abort_seq_read(TS_SKB_CB(state
));
1684 * skb_find_text - Find a text pattern in skb data
1685 * @skb: the buffer to look in
1686 * @from: search offset
1688 * @config: textsearch configuration
1689 * @state: uninitialized textsearch state variable
1691 * Finds a pattern in the skb data according to the specified
1692 * textsearch configuration. Use textsearch_next() to retrieve
1693 * subsequent occurrences of the pattern. Returns the offset
1694 * to the first occurrence or UINT_MAX if no match was found.
1696 unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
1697 unsigned int to
, struct ts_config
*config
,
1698 struct ts_state
*state
)
1700 config
->get_next_block
= skb_ts_get_next_block
;
1701 config
->finish
= skb_ts_finish
;
1703 skb_prepare_seq_read(skb
, from
, to
, TS_SKB_CB(state
));
1705 return textsearch_find(config
, state
);
1709 * skb_append_datato_frags: - append the user data to a skb
1710 * @sk: sock structure
1711 * @skb: skb structure to be appened with user data.
1712 * @getfrag: call back function to be used for getting the user data
1713 * @from: pointer to user message iov
1714 * @length: length of the iov message
1716 * Description: This procedure append the user data in the fragment part
1717 * of the skb if any page alloc fails user this procedure returns -ENOMEM
1719 int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
1720 int (*getfrag
)(void *from
, char *to
, int offset
,
1721 int len
, int odd
, struct sk_buff
*skb
),
1722 void *from
, int length
)
1725 skb_frag_t
*frag
= NULL
;
1726 struct page
*page
= NULL
;
1732 /* Return error if we don't have space for new frag */
1733 frg_cnt
= skb_shinfo(skb
)->nr_frags
;
1734 if (frg_cnt
>= MAX_SKB_FRAGS
)
1737 /* allocate a new page for next frag */
1738 page
= alloc_pages(sk
->sk_allocation
, 0);
1740 /* If alloc_page fails just return failure and caller will
1741 * free previous allocated pages by doing kfree_skb()
1746 /* initialize the next frag */
1747 sk
->sk_sndmsg_page
= page
;
1748 sk
->sk_sndmsg_off
= 0;
1749 skb_fill_page_desc(skb
, frg_cnt
, page
, 0, 0);
1750 skb
->truesize
+= PAGE_SIZE
;
1751 atomic_add(PAGE_SIZE
, &sk
->sk_wmem_alloc
);
1753 /* get the new initialized frag */
1754 frg_cnt
= skb_shinfo(skb
)->nr_frags
;
1755 frag
= &skb_shinfo(skb
)->frags
[frg_cnt
- 1];
1757 /* copy the user data to page */
1758 left
= PAGE_SIZE
- frag
->page_offset
;
1759 copy
= (length
> left
)? left
: length
;
1761 ret
= getfrag(from
, (page_address(frag
->page
) +
1762 frag
->page_offset
+ frag
->size
),
1763 offset
, copy
, 0, skb
);
1767 /* copy was successful so update the size parameters */
1768 sk
->sk_sndmsg_off
+= copy
;
1771 skb
->data_len
+= copy
;
1775 } while (length
> 0);
1780 void __init
skb_init(void)
1782 skbuff_head_cache
= kmem_cache_create("skbuff_head_cache",
1783 sizeof(struct sk_buff
),
1787 if (!skbuff_head_cache
)
1788 panic("cannot create skbuff cache");
1790 skbuff_fclone_cache
= kmem_cache_create("skbuff_fclone_cache",
1791 (2*sizeof(struct sk_buff
)) +
1796 if (!skbuff_fclone_cache
)
1797 panic("cannot create skbuff cache");
1800 EXPORT_SYMBOL(___pskb_trim
);
1801 EXPORT_SYMBOL(__kfree_skb
);
1802 EXPORT_SYMBOL(__pskb_pull_tail
);
1803 EXPORT_SYMBOL(__alloc_skb
);
1804 EXPORT_SYMBOL(pskb_copy
);
1805 EXPORT_SYMBOL(pskb_expand_head
);
1806 EXPORT_SYMBOL(skb_checksum
);
1807 EXPORT_SYMBOL(skb_clone
);
1808 EXPORT_SYMBOL(skb_clone_fraglist
);
1809 EXPORT_SYMBOL(skb_copy
);
1810 EXPORT_SYMBOL(skb_copy_and_csum_bits
);
1811 EXPORT_SYMBOL(skb_copy_and_csum_dev
);
1812 EXPORT_SYMBOL(skb_copy_bits
);
1813 EXPORT_SYMBOL(skb_copy_expand
);
1814 EXPORT_SYMBOL(skb_over_panic
);
1815 EXPORT_SYMBOL(skb_pad
);
1816 EXPORT_SYMBOL(skb_realloc_headroom
);
1817 EXPORT_SYMBOL(skb_under_panic
);
1818 EXPORT_SYMBOL(skb_dequeue
);
1819 EXPORT_SYMBOL(skb_dequeue_tail
);
1820 EXPORT_SYMBOL(skb_insert
);
1821 EXPORT_SYMBOL(skb_queue_purge
);
1822 EXPORT_SYMBOL(skb_queue_head
);
1823 EXPORT_SYMBOL(skb_queue_tail
);
1824 EXPORT_SYMBOL(skb_unlink
);
1825 EXPORT_SYMBOL(skb_append
);
1826 EXPORT_SYMBOL(skb_split
);
1827 EXPORT_SYMBOL(skb_prepare_seq_read
);
1828 EXPORT_SYMBOL(skb_seq_read
);
1829 EXPORT_SYMBOL(skb_abort_seq_read
);
1830 EXPORT_SYMBOL(skb_find_text
);
1831 EXPORT_SYMBOL(skb_append_datato_frags
);