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
,
138 struct skb_shared_info
*shinfo
;
143 skb
= kmem_cache_alloc(fclone
? skbuff_fclone_cache
: skbuff_head_cache
,
144 gfp_mask
& ~__GFP_DMA
);
148 /* Get the DATA. Size must match skb_add_mtu(). */
149 size
= SKB_DATA_ALIGN(size
);
150 data
= kmalloc(size
+ sizeof(struct skb_shared_info
), gfp_mask
);
154 memset(skb
, 0, offsetof(struct sk_buff
, truesize
));
155 skb
->truesize
= size
+ sizeof(struct sk_buff
);
156 atomic_set(&skb
->users
, 1);
160 skb
->end
= data
+ size
;
161 /* make sure we initialize shinfo sequentially */
162 shinfo
= skb_shinfo(skb
);
163 atomic_set(&shinfo
->dataref
, 1);
164 shinfo
->nr_frags
= 0;
165 shinfo
->tso_size
= 0;
166 shinfo
->tso_segs
= 0;
167 shinfo
->ufo_size
= 0;
168 shinfo
->ip6_frag_id
= 0;
169 shinfo
->frag_list
= NULL
;
172 struct sk_buff
*child
= skb
+ 1;
173 atomic_t
*fclone_ref
= (atomic_t
*) (child
+ 1);
175 skb
->fclone
= SKB_FCLONE_ORIG
;
176 atomic_set(fclone_ref
, 1);
178 child
->fclone
= SKB_FCLONE_UNAVAILABLE
;
183 kmem_cache_free(skbuff_head_cache
, skb
);
189 * alloc_skb_from_cache - allocate a network buffer
190 * @cp: kmem_cache from which to allocate the data area
191 * (object size must be big enough for @size bytes + skb overheads)
192 * @size: size to allocate
193 * @gfp_mask: allocation mask
195 * Allocate a new &sk_buff. The returned buffer has no headroom and
196 * tail room of size bytes. The object has a reference count of one.
197 * The return is the buffer. On a failure the return is %NULL.
199 * Buffers may only be allocated from interrupts using a @gfp_mask of
202 struct sk_buff
*alloc_skb_from_cache(kmem_cache_t
*cp
,
210 skb
= kmem_cache_alloc(skbuff_head_cache
,
211 gfp_mask
& ~__GFP_DMA
);
216 size
= SKB_DATA_ALIGN(size
);
217 data
= kmem_cache_alloc(cp
, gfp_mask
);
221 memset(skb
, 0, offsetof(struct sk_buff
, truesize
));
222 skb
->truesize
= size
+ sizeof(struct sk_buff
);
223 atomic_set(&skb
->users
, 1);
227 skb
->end
= data
+ size
;
229 atomic_set(&(skb_shinfo(skb
)->dataref
), 1);
230 skb_shinfo(skb
)->nr_frags
= 0;
231 skb_shinfo(skb
)->tso_size
= 0;
232 skb_shinfo(skb
)->tso_segs
= 0;
233 skb_shinfo(skb
)->frag_list
= NULL
;
237 kmem_cache_free(skbuff_head_cache
, skb
);
243 static void skb_drop_fraglist(struct sk_buff
*skb
)
245 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
247 skb_shinfo(skb
)->frag_list
= NULL
;
250 struct sk_buff
*this = list
;
256 static void skb_clone_fraglist(struct sk_buff
*skb
)
258 struct sk_buff
*list
;
260 for (list
= skb_shinfo(skb
)->frag_list
; list
; list
= list
->next
)
264 void skb_release_data(struct sk_buff
*skb
)
267 !atomic_sub_return(skb
->nohdr
? (1 << SKB_DATAREF_SHIFT
) + 1 : 1,
268 &skb_shinfo(skb
)->dataref
)) {
269 if (skb_shinfo(skb
)->nr_frags
) {
271 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++)
272 put_page(skb_shinfo(skb
)->frags
[i
].page
);
275 if (skb_shinfo(skb
)->frag_list
)
276 skb_drop_fraglist(skb
);
283 * Free an skbuff by memory without cleaning the state.
285 void kfree_skbmem(struct sk_buff
*skb
)
287 struct sk_buff
*other
;
288 atomic_t
*fclone_ref
;
290 skb_release_data(skb
);
291 switch (skb
->fclone
) {
292 case SKB_FCLONE_UNAVAILABLE
:
293 kmem_cache_free(skbuff_head_cache
, skb
);
296 case SKB_FCLONE_ORIG
:
297 fclone_ref
= (atomic_t
*) (skb
+ 2);
298 if (atomic_dec_and_test(fclone_ref
))
299 kmem_cache_free(skbuff_fclone_cache
, skb
);
302 case SKB_FCLONE_CLONE
:
303 fclone_ref
= (atomic_t
*) (skb
+ 1);
306 /* The clone portion is available for
307 * fast-cloning again.
309 skb
->fclone
= SKB_FCLONE_UNAVAILABLE
;
311 if (atomic_dec_and_test(fclone_ref
))
312 kmem_cache_free(skbuff_fclone_cache
, other
);
318 * __kfree_skb - private function
321 * Free an sk_buff. Release anything attached to the buffer.
322 * Clean the state. This is an internal helper function. Users should
323 * always call kfree_skb
326 void __kfree_skb(struct sk_buff
*skb
)
328 dst_release(skb
->dst
);
330 secpath_put(skb
->sp
);
332 if (skb
->destructor
) {
334 skb
->destructor(skb
);
336 #ifdef CONFIG_NETFILTER
337 nf_conntrack_put(skb
->nfct
);
338 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
339 nf_conntrack_put_reasm(skb
->nfct_reasm
);
341 #ifdef CONFIG_BRIDGE_NETFILTER
342 nf_bridge_put(skb
->nf_bridge
);
345 /* XXX: IS this still necessary? - JHS */
346 #ifdef CONFIG_NET_SCHED
348 #ifdef CONFIG_NET_CLS_ACT
357 * skb_clone - duplicate an sk_buff
358 * @skb: buffer to clone
359 * @gfp_mask: allocation priority
361 * Duplicate an &sk_buff. The new one is not owned by a socket. Both
362 * copies share the same packet data but not structure. The new
363 * buffer has a reference count of 1. If the allocation fails the
364 * function returns %NULL otherwise the new buffer is returned.
366 * If this function is called from an interrupt gfp_mask() must be
370 struct sk_buff
*skb_clone(struct sk_buff
*skb
, gfp_t gfp_mask
)
375 if (skb
->fclone
== SKB_FCLONE_ORIG
&&
376 n
->fclone
== SKB_FCLONE_UNAVAILABLE
) {
377 atomic_t
*fclone_ref
= (atomic_t
*) (n
+ 1);
378 n
->fclone
= SKB_FCLONE_CLONE
;
379 atomic_inc(fclone_ref
);
381 n
= kmem_cache_alloc(skbuff_head_cache
, gfp_mask
);
384 n
->fclone
= SKB_FCLONE_UNAVAILABLE
;
387 #define C(x) n->x = skb->x
389 n
->next
= n
->prev
= NULL
;
400 secpath_get(skb
->sp
);
402 memcpy(n
->cb
, skb
->cb
, sizeof(skb
->cb
));
413 n
->destructor
= NULL
;
414 #ifdef CONFIG_NETFILTER
417 nf_conntrack_get(skb
->nfct
);
419 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
421 nf_conntrack_get_reasm(skb
->nfct_reasm
);
423 #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
426 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
428 nf_conntrack_get_reasm(skb
->nfct_reasm
);
430 #ifdef CONFIG_BRIDGE_NETFILTER
432 nf_bridge_get(skb
->nf_bridge
);
434 #endif /*CONFIG_NETFILTER*/
435 #ifdef CONFIG_NET_SCHED
437 #ifdef CONFIG_NET_CLS_ACT
438 n
->tc_verd
= SET_TC_VERD(skb
->tc_verd
,0);
439 n
->tc_verd
= CLR_TC_OK2MUNGE(n
->tc_verd
);
440 n
->tc_verd
= CLR_TC_MUNGED(n
->tc_verd
);
446 atomic_set(&n
->users
, 1);
452 atomic_inc(&(skb_shinfo(skb
)->dataref
));
458 static void copy_skb_header(struct sk_buff
*new, const struct sk_buff
*old
)
461 * Shift between the two data areas in bytes
463 unsigned long offset
= new->data
- old
->data
;
467 new->priority
= old
->priority
;
468 new->protocol
= old
->protocol
;
469 new->dst
= dst_clone(old
->dst
);
471 new->sp
= secpath_get(old
->sp
);
473 new->h
.raw
= old
->h
.raw
+ offset
;
474 new->nh
.raw
= old
->nh
.raw
+ offset
;
475 new->mac
.raw
= old
->mac
.raw
+ offset
;
476 memcpy(new->cb
, old
->cb
, sizeof(old
->cb
));
477 new->local_df
= old
->local_df
;
478 new->fclone
= SKB_FCLONE_UNAVAILABLE
;
479 new->pkt_type
= old
->pkt_type
;
480 new->tstamp
= old
->tstamp
;
481 new->destructor
= NULL
;
482 #ifdef CONFIG_NETFILTER
483 new->nfmark
= old
->nfmark
;
484 new->nfct
= old
->nfct
;
485 nf_conntrack_get(old
->nfct
);
486 new->nfctinfo
= old
->nfctinfo
;
487 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
488 new->nfct_reasm
= old
->nfct_reasm
;
489 nf_conntrack_get_reasm(old
->nfct_reasm
);
491 #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
492 new->ipvs_property
= old
->ipvs_property
;
494 #ifdef CONFIG_BRIDGE_NETFILTER
495 new->nf_bridge
= old
->nf_bridge
;
496 nf_bridge_get(old
->nf_bridge
);
499 #ifdef CONFIG_NET_SCHED
500 #ifdef CONFIG_NET_CLS_ACT
501 new->tc_verd
= old
->tc_verd
;
503 new->tc_index
= old
->tc_index
;
505 atomic_set(&new->users
, 1);
506 skb_shinfo(new)->tso_size
= skb_shinfo(old
)->tso_size
;
507 skb_shinfo(new)->tso_segs
= skb_shinfo(old
)->tso_segs
;
511 * skb_copy - create private copy of an sk_buff
512 * @skb: buffer to copy
513 * @gfp_mask: allocation priority
515 * Make a copy of both an &sk_buff and its data. This is used when the
516 * caller wishes to modify the data and needs a private copy of the
517 * data to alter. Returns %NULL on failure or the pointer to the buffer
518 * on success. The returned buffer has a reference count of 1.
520 * As by-product this function converts non-linear &sk_buff to linear
521 * one, so that &sk_buff becomes completely private and caller is allowed
522 * to modify all the data of returned buffer. This means that this
523 * function is not recommended for use in circumstances when only
524 * header is going to be modified. Use pskb_copy() instead.
527 struct sk_buff
*skb_copy(const struct sk_buff
*skb
, gfp_t gfp_mask
)
529 int headerlen
= skb
->data
- skb
->head
;
531 * Allocate the copy buffer
533 struct sk_buff
*n
= alloc_skb(skb
->end
- skb
->head
+ skb
->data_len
,
538 /* Set the data pointer */
539 skb_reserve(n
, headerlen
);
540 /* Set the tail pointer and length */
541 skb_put(n
, skb
->len
);
543 n
->ip_summed
= skb
->ip_summed
;
545 if (skb_copy_bits(skb
, -headerlen
, n
->head
, headerlen
+ skb
->len
))
548 copy_skb_header(n
, skb
);
554 * pskb_copy - create copy of an sk_buff with private head.
555 * @skb: buffer to copy
556 * @gfp_mask: allocation priority
558 * Make a copy of both an &sk_buff and part of its data, located
559 * in header. Fragmented data remain shared. This is used when
560 * the caller wishes to modify only header of &sk_buff and needs
561 * private copy of the header to alter. Returns %NULL on failure
562 * or the pointer to the buffer on success.
563 * The returned buffer has a reference count of 1.
566 struct sk_buff
*pskb_copy(struct sk_buff
*skb
, gfp_t gfp_mask
)
569 * Allocate the copy buffer
571 struct sk_buff
*n
= alloc_skb(skb
->end
- skb
->head
, gfp_mask
);
576 /* Set the data pointer */
577 skb_reserve(n
, skb
->data
- skb
->head
);
578 /* Set the tail pointer and length */
579 skb_put(n
, skb_headlen(skb
));
581 memcpy(n
->data
, skb
->data
, n
->len
);
583 n
->ip_summed
= skb
->ip_summed
;
585 n
->data_len
= skb
->data_len
;
588 if (skb_shinfo(skb
)->nr_frags
) {
591 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
592 skb_shinfo(n
)->frags
[i
] = skb_shinfo(skb
)->frags
[i
];
593 get_page(skb_shinfo(n
)->frags
[i
].page
);
595 skb_shinfo(n
)->nr_frags
= i
;
598 if (skb_shinfo(skb
)->frag_list
) {
599 skb_shinfo(n
)->frag_list
= skb_shinfo(skb
)->frag_list
;
600 skb_clone_fraglist(n
);
603 copy_skb_header(n
, skb
);
609 * pskb_expand_head - reallocate header of &sk_buff
610 * @skb: buffer to reallocate
611 * @nhead: room to add at head
612 * @ntail: room to add at tail
613 * @gfp_mask: allocation priority
615 * Expands (or creates identical copy, if &nhead and &ntail are zero)
616 * header of skb. &sk_buff itself is not changed. &sk_buff MUST have
617 * reference count of 1. Returns zero in the case of success or error,
618 * if expansion failed. In the last case, &sk_buff is not changed.
620 * All the pointers pointing into skb header may change and must be
621 * reloaded after call to this function.
624 int pskb_expand_head(struct sk_buff
*skb
, int nhead
, int ntail
,
629 int size
= nhead
+ (skb
->end
- skb
->head
) + ntail
;
635 size
= SKB_DATA_ALIGN(size
);
637 data
= kmalloc(size
+ sizeof(struct skb_shared_info
), gfp_mask
);
641 /* Copy only real data... and, alas, header. This should be
642 * optimized for the cases when header is void. */
643 memcpy(data
+ nhead
, skb
->head
, skb
->tail
- skb
->head
);
644 memcpy(data
+ size
, skb
->end
, sizeof(struct skb_shared_info
));
646 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++)
647 get_page(skb_shinfo(skb
)->frags
[i
].page
);
649 if (skb_shinfo(skb
)->frag_list
)
650 skb_clone_fraglist(skb
);
652 skb_release_data(skb
);
654 off
= (data
+ nhead
) - skb
->head
;
657 skb
->end
= data
+ size
;
665 atomic_set(&skb_shinfo(skb
)->dataref
, 1);
672 /* Make private copy of skb with writable head and some headroom */
674 struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
, unsigned int headroom
)
676 struct sk_buff
*skb2
;
677 int delta
= headroom
- skb_headroom(skb
);
680 skb2
= pskb_copy(skb
, GFP_ATOMIC
);
682 skb2
= skb_clone(skb
, GFP_ATOMIC
);
683 if (skb2
&& pskb_expand_head(skb2
, SKB_DATA_ALIGN(delta
), 0,
694 * skb_copy_expand - copy and expand sk_buff
695 * @skb: buffer to copy
696 * @newheadroom: new free bytes at head
697 * @newtailroom: new free bytes at tail
698 * @gfp_mask: allocation priority
700 * Make a copy of both an &sk_buff and its data and while doing so
701 * allocate additional space.
703 * This is used when the caller wishes to modify the data and needs a
704 * private copy of the data to alter as well as more space for new fields.
705 * Returns %NULL on failure or the pointer to the buffer
706 * on success. The returned buffer has a reference count of 1.
708 * You must pass %GFP_ATOMIC as the allocation priority if this function
709 * is called from an interrupt.
711 * BUG ALERT: ip_summed is not copied. Why does this work? Is it used
712 * only by netfilter in the cases when checksum is recalculated? --ANK
714 struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
715 int newheadroom
, int newtailroom
,
719 * Allocate the copy buffer
721 struct sk_buff
*n
= alloc_skb(newheadroom
+ skb
->len
+ newtailroom
,
723 int head_copy_len
, head_copy_off
;
728 skb_reserve(n
, newheadroom
);
730 /* Set the tail pointer and length */
731 skb_put(n
, skb
->len
);
733 head_copy_len
= skb_headroom(skb
);
735 if (newheadroom
<= head_copy_len
)
736 head_copy_len
= newheadroom
;
738 head_copy_off
= newheadroom
- head_copy_len
;
740 /* Copy the linear header and data. */
741 if (skb_copy_bits(skb
, -head_copy_len
, n
->head
+ head_copy_off
,
742 skb
->len
+ head_copy_len
))
745 copy_skb_header(n
, skb
);
751 * skb_pad - zero pad the tail of an skb
752 * @skb: buffer to pad
755 * Ensure that a buffer is followed by a padding area that is zero
756 * filled. Used by network drivers which may DMA or transfer data
757 * beyond the buffer end onto the wire.
759 * May return NULL in out of memory cases.
762 struct sk_buff
*skb_pad(struct sk_buff
*skb
, int pad
)
764 struct sk_buff
*nskb
;
766 /* If the skbuff is non linear tailroom is always zero.. */
767 if (skb_tailroom(skb
) >= pad
) {
768 memset(skb
->data
+skb
->len
, 0, pad
);
772 nskb
= skb_copy_expand(skb
, skb_headroom(skb
), skb_tailroom(skb
) + pad
, GFP_ATOMIC
);
775 memset(nskb
->data
+nskb
->len
, 0, pad
);
779 /* Trims skb to length len. It can change skb pointers, if "realloc" is 1.
780 * If realloc==0 and trimming is impossible without change of data,
784 int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
, int realloc
)
786 int offset
= skb_headlen(skb
);
787 int nfrags
= skb_shinfo(skb
)->nr_frags
;
790 for (i
= 0; i
< nfrags
; i
++) {
791 int end
= offset
+ skb_shinfo(skb
)->frags
[i
].size
;
793 if (skb_cloned(skb
)) {
796 if (pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
))
800 put_page(skb_shinfo(skb
)->frags
[i
].page
);
801 skb_shinfo(skb
)->nr_frags
--;
803 skb_shinfo(skb
)->frags
[i
].size
= len
- offset
;
810 skb
->data_len
-= skb
->len
- len
;
813 if (len
<= skb_headlen(skb
)) {
816 skb
->tail
= skb
->data
+ len
;
817 if (skb_shinfo(skb
)->frag_list
&& !skb_cloned(skb
))
818 skb_drop_fraglist(skb
);
820 skb
->data_len
-= skb
->len
- len
;
829 * __pskb_pull_tail - advance tail of skb header
830 * @skb: buffer to reallocate
831 * @delta: number of bytes to advance tail
833 * The function makes a sense only on a fragmented &sk_buff,
834 * it expands header moving its tail forward and copying necessary
835 * data from fragmented part.
837 * &sk_buff MUST have reference count of 1.
839 * Returns %NULL (and &sk_buff does not change) if pull failed
840 * or value of new tail of skb in the case of success.
842 * All the pointers pointing into skb header may change and must be
843 * reloaded after call to this function.
846 /* Moves tail of skb head forward, copying data from fragmented part,
847 * when it is necessary.
848 * 1. It may fail due to malloc failure.
849 * 2. It may change skb pointers.
851 * It is pretty complicated. Luckily, it is called only in exceptional cases.
853 unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
)
855 /* If skb has not enough free space at tail, get new one
856 * plus 128 bytes for future expansions. If we have enough
857 * room at tail, reallocate without expansion only if skb is cloned.
859 int i
, k
, eat
= (skb
->tail
+ delta
) - skb
->end
;
861 if (eat
> 0 || skb_cloned(skb
)) {
862 if (pskb_expand_head(skb
, 0, eat
> 0 ? eat
+ 128 : 0,
867 if (skb_copy_bits(skb
, skb_headlen(skb
), skb
->tail
, delta
))
870 /* Optimization: no fragments, no reasons to preestimate
871 * size of pulled pages. Superb.
873 if (!skb_shinfo(skb
)->frag_list
)
876 /* Estimate size of pulled pages. */
878 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
879 if (skb_shinfo(skb
)->frags
[i
].size
>= eat
)
881 eat
-= skb_shinfo(skb
)->frags
[i
].size
;
884 /* If we need update frag list, we are in troubles.
885 * Certainly, it possible to add an offset to skb data,
886 * but taking into account that pulling is expected to
887 * be very rare operation, it is worth to fight against
888 * further bloating skb head and crucify ourselves here instead.
889 * Pure masohism, indeed. 8)8)
892 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
893 struct sk_buff
*clone
= NULL
;
894 struct sk_buff
*insp
= NULL
;
900 if (list
->len
<= eat
) {
901 /* Eaten as whole. */
906 /* Eaten partially. */
908 if (skb_shared(list
)) {
909 /* Sucks! We need to fork list. :-( */
910 clone
= skb_clone(list
, GFP_ATOMIC
);
916 /* This may be pulled without
920 if (!pskb_pull(list
, eat
)) {
929 /* Free pulled out fragments. */
930 while ((list
= skb_shinfo(skb
)->frag_list
) != insp
) {
931 skb_shinfo(skb
)->frag_list
= list
->next
;
934 /* And insert new clone at head. */
937 skb_shinfo(skb
)->frag_list
= clone
;
940 /* Success! Now we may commit changes to skb data. */
945 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
946 if (skb_shinfo(skb
)->frags
[i
].size
<= eat
) {
947 put_page(skb_shinfo(skb
)->frags
[i
].page
);
948 eat
-= skb_shinfo(skb
)->frags
[i
].size
;
950 skb_shinfo(skb
)->frags
[k
] = skb_shinfo(skb
)->frags
[i
];
952 skb_shinfo(skb
)->frags
[k
].page_offset
+= eat
;
953 skb_shinfo(skb
)->frags
[k
].size
-= eat
;
959 skb_shinfo(skb
)->nr_frags
= k
;
962 skb
->data_len
-= delta
;
967 /* Copy some data bits from skb to kernel buffer. */
969 int skb_copy_bits(const struct sk_buff
*skb
, int offset
, void *to
, int len
)
972 int start
= skb_headlen(skb
);
974 if (offset
> (int)skb
->len
- len
)
978 if ((copy
= start
- offset
) > 0) {
981 memcpy(to
, skb
->data
+ offset
, copy
);
982 if ((len
-= copy
) == 0)
988 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
991 BUG_TRAP(start
<= offset
+ len
);
993 end
= start
+ skb_shinfo(skb
)->frags
[i
].size
;
994 if ((copy
= end
- offset
) > 0) {
1000 vaddr
= kmap_skb_frag(&skb_shinfo(skb
)->frags
[i
]);
1002 vaddr
+ skb_shinfo(skb
)->frags
[i
].page_offset
+
1003 offset
- start
, copy
);
1004 kunmap_skb_frag(vaddr
);
1006 if ((len
-= copy
) == 0)
1014 if (skb_shinfo(skb
)->frag_list
) {
1015 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1017 for (; list
; list
= list
->next
) {
1020 BUG_TRAP(start
<= offset
+ len
);
1022 end
= start
+ list
->len
;
1023 if ((copy
= end
- offset
) > 0) {
1026 if (skb_copy_bits(list
, offset
- start
,
1029 if ((len
-= copy
) == 0)
1045 * skb_store_bits - store bits from kernel buffer to skb
1046 * @skb: destination buffer
1047 * @offset: offset in destination
1048 * @from: source buffer
1049 * @len: number of bytes to copy
1051 * Copy the specified number of bytes from the source buffer to the
1052 * destination skb. This function handles all the messy bits of
1053 * traversing fragment lists and such.
1056 int skb_store_bits(const struct sk_buff
*skb
, int offset
, void *from
, int len
)
1059 int start
= skb_headlen(skb
);
1061 if (offset
> (int)skb
->len
- len
)
1064 if ((copy
= start
- offset
) > 0) {
1067 memcpy(skb
->data
+ offset
, from
, copy
);
1068 if ((len
-= copy
) == 0)
1074 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1075 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1078 BUG_TRAP(start
<= offset
+ len
);
1080 end
= start
+ frag
->size
;
1081 if ((copy
= end
- offset
) > 0) {
1087 vaddr
= kmap_skb_frag(frag
);
1088 memcpy(vaddr
+ frag
->page_offset
+ offset
- start
,
1090 kunmap_skb_frag(vaddr
);
1092 if ((len
-= copy
) == 0)
1100 if (skb_shinfo(skb
)->frag_list
) {
1101 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1103 for (; list
; list
= list
->next
) {
1106 BUG_TRAP(start
<= offset
+ len
);
1108 end
= start
+ list
->len
;
1109 if ((copy
= end
- offset
) > 0) {
1112 if (skb_store_bits(list
, offset
- start
,
1115 if ((len
-= copy
) == 0)
1130 EXPORT_SYMBOL(skb_store_bits
);
1132 /* Checksum skb data. */
1134 unsigned int skb_checksum(const struct sk_buff
*skb
, int offset
,
1135 int len
, unsigned int csum
)
1137 int start
= skb_headlen(skb
);
1138 int i
, copy
= start
- offset
;
1141 /* Checksum header. */
1145 csum
= csum_partial(skb
->data
+ offset
, copy
, csum
);
1146 if ((len
-= copy
) == 0)
1152 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1155 BUG_TRAP(start
<= offset
+ len
);
1157 end
= start
+ skb_shinfo(skb
)->frags
[i
].size
;
1158 if ((copy
= end
- offset
) > 0) {
1161 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1165 vaddr
= kmap_skb_frag(frag
);
1166 csum2
= csum_partial(vaddr
+ frag
->page_offset
+
1167 offset
- start
, copy
, 0);
1168 kunmap_skb_frag(vaddr
);
1169 csum
= csum_block_add(csum
, csum2
, pos
);
1178 if (skb_shinfo(skb
)->frag_list
) {
1179 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1181 for (; list
; list
= list
->next
) {
1184 BUG_TRAP(start
<= offset
+ len
);
1186 end
= start
+ list
->len
;
1187 if ((copy
= end
- offset
) > 0) {
1191 csum2
= skb_checksum(list
, offset
- start
,
1193 csum
= csum_block_add(csum
, csum2
, pos
);
1194 if ((len
-= copy
) == 0)
1208 /* Both of above in one bottle. */
1210 unsigned int skb_copy_and_csum_bits(const struct sk_buff
*skb
, int offset
,
1211 u8
*to
, int len
, unsigned int csum
)
1213 int start
= skb_headlen(skb
);
1214 int i
, copy
= start
- offset
;
1221 csum
= csum_partial_copy_nocheck(skb
->data
+ offset
, to
,
1223 if ((len
-= copy
) == 0)
1230 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1233 BUG_TRAP(start
<= offset
+ len
);
1235 end
= start
+ skb_shinfo(skb
)->frags
[i
].size
;
1236 if ((copy
= end
- offset
) > 0) {
1239 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1243 vaddr
= kmap_skb_frag(frag
);
1244 csum2
= csum_partial_copy_nocheck(vaddr
+
1248 kunmap_skb_frag(vaddr
);
1249 csum
= csum_block_add(csum
, csum2
, pos
);
1259 if (skb_shinfo(skb
)->frag_list
) {
1260 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1262 for (; list
; list
= list
->next
) {
1266 BUG_TRAP(start
<= offset
+ len
);
1268 end
= start
+ list
->len
;
1269 if ((copy
= end
- offset
) > 0) {
1272 csum2
= skb_copy_and_csum_bits(list
,
1275 csum
= csum_block_add(csum
, csum2
, pos
);
1276 if ((len
-= copy
) == 0)
1290 void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
)
1295 if (skb
->ip_summed
== CHECKSUM_HW
)
1296 csstart
= skb
->h
.raw
- skb
->data
;
1298 csstart
= skb_headlen(skb
);
1300 if (csstart
> skb_headlen(skb
))
1303 memcpy(to
, skb
->data
, csstart
);
1306 if (csstart
!= skb
->len
)
1307 csum
= skb_copy_and_csum_bits(skb
, csstart
, to
+ csstart
,
1308 skb
->len
- csstart
, 0);
1310 if (skb
->ip_summed
== CHECKSUM_HW
) {
1311 long csstuff
= csstart
+ skb
->csum
;
1313 *((unsigned short *)(to
+ csstuff
)) = csum_fold(csum
);
1318 * skb_dequeue - remove from the head of the queue
1319 * @list: list to dequeue from
1321 * Remove the head of the list. The list lock is taken so the function
1322 * may be used safely with other locking list functions. The head item is
1323 * returned or %NULL if the list is empty.
1326 struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
)
1328 unsigned long flags
;
1329 struct sk_buff
*result
;
1331 spin_lock_irqsave(&list
->lock
, flags
);
1332 result
= __skb_dequeue(list
);
1333 spin_unlock_irqrestore(&list
->lock
, flags
);
1338 * skb_dequeue_tail - remove from the tail of the queue
1339 * @list: list to dequeue from
1341 * Remove the tail of the list. The list lock is taken so the function
1342 * may be used safely with other locking list functions. The tail item is
1343 * returned or %NULL if the list is empty.
1345 struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
)
1347 unsigned long flags
;
1348 struct sk_buff
*result
;
1350 spin_lock_irqsave(&list
->lock
, flags
);
1351 result
= __skb_dequeue_tail(list
);
1352 spin_unlock_irqrestore(&list
->lock
, flags
);
1357 * skb_queue_purge - empty a list
1358 * @list: list to empty
1360 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1361 * the list and one reference dropped. This function takes the list
1362 * lock and is atomic with respect to other list locking functions.
1364 void skb_queue_purge(struct sk_buff_head
*list
)
1366 struct sk_buff
*skb
;
1367 while ((skb
= skb_dequeue(list
)) != NULL
)
1372 * skb_queue_head - queue a buffer at the list head
1373 * @list: list to use
1374 * @newsk: buffer to queue
1376 * Queue a buffer at the start of the list. This function takes the
1377 * list lock and can be used safely with other locking &sk_buff functions
1380 * A buffer cannot be placed on two lists at the same time.
1382 void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
)
1384 unsigned long flags
;
1386 spin_lock_irqsave(&list
->lock
, flags
);
1387 __skb_queue_head(list
, newsk
);
1388 spin_unlock_irqrestore(&list
->lock
, flags
);
1392 * skb_queue_tail - queue a buffer at the list tail
1393 * @list: list to use
1394 * @newsk: buffer to queue
1396 * Queue a buffer at the tail of the list. This function takes the
1397 * list lock and can be used safely with other locking &sk_buff functions
1400 * A buffer cannot be placed on two lists at the same time.
1402 void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
)
1404 unsigned long flags
;
1406 spin_lock_irqsave(&list
->lock
, flags
);
1407 __skb_queue_tail(list
, newsk
);
1408 spin_unlock_irqrestore(&list
->lock
, flags
);
1412 * skb_unlink - remove a buffer from a list
1413 * @skb: buffer to remove
1414 * @list: list to use
1416 * Remove a packet from a list. The list locks are taken and this
1417 * function is atomic with respect to other list locked calls
1419 * You must know what list the SKB is on.
1421 void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1423 unsigned long flags
;
1425 spin_lock_irqsave(&list
->lock
, flags
);
1426 __skb_unlink(skb
, list
);
1427 spin_unlock_irqrestore(&list
->lock
, flags
);
1431 * skb_append - append a buffer
1432 * @old: buffer to insert after
1433 * @newsk: buffer to insert
1434 * @list: list to use
1436 * Place a packet after a given packet in a list. The list locks are taken
1437 * and this function is atomic with respect to other list locked calls.
1438 * A buffer cannot be placed on two lists at the same time.
1440 void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
)
1442 unsigned long flags
;
1444 spin_lock_irqsave(&list
->lock
, flags
);
1445 __skb_append(old
, newsk
, list
);
1446 spin_unlock_irqrestore(&list
->lock
, flags
);
1451 * skb_insert - insert a buffer
1452 * @old: buffer to insert before
1453 * @newsk: buffer to insert
1454 * @list: list to use
1456 * Place a packet before a given packet in a list. The list locks are
1457 * taken and this function is atomic with respect to other list locked
1460 * A buffer cannot be placed on two lists at the same time.
1462 void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
)
1464 unsigned long flags
;
1466 spin_lock_irqsave(&list
->lock
, flags
);
1467 __skb_insert(newsk
, old
->prev
, old
, list
);
1468 spin_unlock_irqrestore(&list
->lock
, flags
);
1473 * Tune the memory allocator for a new MTU size.
1475 void skb_add_mtu(int mtu
)
1477 /* Must match allocation in alloc_skb */
1478 mtu
= SKB_DATA_ALIGN(mtu
) + sizeof(struct skb_shared_info
);
1480 kmem_add_cache_size(mtu
);
1484 static inline void skb_split_inside_header(struct sk_buff
*skb
,
1485 struct sk_buff
* skb1
,
1486 const u32 len
, const int pos
)
1490 memcpy(skb_put(skb1
, pos
- len
), skb
->data
+ len
, pos
- len
);
1492 /* And move data appendix as is. */
1493 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++)
1494 skb_shinfo(skb1
)->frags
[i
] = skb_shinfo(skb
)->frags
[i
];
1496 skb_shinfo(skb1
)->nr_frags
= skb_shinfo(skb
)->nr_frags
;
1497 skb_shinfo(skb
)->nr_frags
= 0;
1498 skb1
->data_len
= skb
->data_len
;
1499 skb1
->len
+= skb1
->data_len
;
1502 skb
->tail
= skb
->data
+ len
;
1505 static inline void skb_split_no_header(struct sk_buff
*skb
,
1506 struct sk_buff
* skb1
,
1507 const u32 len
, int pos
)
1510 const int nfrags
= skb_shinfo(skb
)->nr_frags
;
1512 skb_shinfo(skb
)->nr_frags
= 0;
1513 skb1
->len
= skb1
->data_len
= skb
->len
- len
;
1515 skb
->data_len
= len
- pos
;
1517 for (i
= 0; i
< nfrags
; i
++) {
1518 int size
= skb_shinfo(skb
)->frags
[i
].size
;
1520 if (pos
+ size
> len
) {
1521 skb_shinfo(skb1
)->frags
[k
] = skb_shinfo(skb
)->frags
[i
];
1525 * We have two variants in this case:
1526 * 1. Move all the frag to the second
1527 * part, if it is possible. F.e.
1528 * this approach is mandatory for TUX,
1529 * where splitting is expensive.
1530 * 2. Split is accurately. We make this.
1532 get_page(skb_shinfo(skb
)->frags
[i
].page
);
1533 skb_shinfo(skb1
)->frags
[0].page_offset
+= len
- pos
;
1534 skb_shinfo(skb1
)->frags
[0].size
-= len
- pos
;
1535 skb_shinfo(skb
)->frags
[i
].size
= len
- pos
;
1536 skb_shinfo(skb
)->nr_frags
++;
1540 skb_shinfo(skb
)->nr_frags
++;
1543 skb_shinfo(skb1
)->nr_frags
= k
;
1547 * skb_split - Split fragmented skb to two parts at length len.
1548 * @skb: the buffer to split
1549 * @skb1: the buffer to receive the second part
1550 * @len: new length for skb
1552 void skb_split(struct sk_buff
*skb
, struct sk_buff
*skb1
, const u32 len
)
1554 int pos
= skb_headlen(skb
);
1556 if (len
< pos
) /* Split line is inside header. */
1557 skb_split_inside_header(skb
, skb1
, len
, pos
);
1558 else /* Second chunk has no header, nothing to copy. */
1559 skb_split_no_header(skb
, skb1
, len
, pos
);
1563 * skb_prepare_seq_read - Prepare a sequential read of skb data
1564 * @skb: the buffer to read
1565 * @from: lower offset of data to be read
1566 * @to: upper offset of data to be read
1567 * @st: state variable
1569 * Initializes the specified state variable. Must be called before
1570 * invoking skb_seq_read() for the first time.
1572 void skb_prepare_seq_read(struct sk_buff
*skb
, unsigned int from
,
1573 unsigned int to
, struct skb_seq_state
*st
)
1575 st
->lower_offset
= from
;
1576 st
->upper_offset
= to
;
1577 st
->root_skb
= st
->cur_skb
= skb
;
1578 st
->frag_idx
= st
->stepped_offset
= 0;
1579 st
->frag_data
= NULL
;
1583 * skb_seq_read - Sequentially read skb data
1584 * @consumed: number of bytes consumed by the caller so far
1585 * @data: destination pointer for data to be returned
1586 * @st: state variable
1588 * Reads a block of skb data at &consumed relative to the
1589 * lower offset specified to skb_prepare_seq_read(). Assigns
1590 * the head of the data block to &data and returns the length
1591 * of the block or 0 if the end of the skb data or the upper
1592 * offset has been reached.
1594 * The caller is not required to consume all of the data
1595 * returned, i.e. &consumed is typically set to the number
1596 * of bytes already consumed and the next call to
1597 * skb_seq_read() will return the remaining part of the block.
1599 * Note: The size of each block of data returned can be arbitary,
1600 * this limitation is the cost for zerocopy seqeuental
1601 * reads of potentially non linear data.
1603 * Note: Fragment lists within fragments are not implemented
1604 * at the moment, state->root_skb could be replaced with
1605 * a stack for this purpose.
1607 unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
1608 struct skb_seq_state
*st
)
1610 unsigned int block_limit
, abs_offset
= consumed
+ st
->lower_offset
;
1613 if (unlikely(abs_offset
>= st
->upper_offset
))
1617 block_limit
= skb_headlen(st
->cur_skb
);
1619 if (abs_offset
< block_limit
) {
1620 *data
= st
->cur_skb
->data
+ abs_offset
;
1621 return block_limit
- abs_offset
;
1624 if (st
->frag_idx
== 0 && !st
->frag_data
)
1625 st
->stepped_offset
+= skb_headlen(st
->cur_skb
);
1627 while (st
->frag_idx
< skb_shinfo(st
->cur_skb
)->nr_frags
) {
1628 frag
= &skb_shinfo(st
->cur_skb
)->frags
[st
->frag_idx
];
1629 block_limit
= frag
->size
+ st
->stepped_offset
;
1631 if (abs_offset
< block_limit
) {
1633 st
->frag_data
= kmap_skb_frag(frag
);
1635 *data
= (u8
*) st
->frag_data
+ frag
->page_offset
+
1636 (abs_offset
- st
->stepped_offset
);
1638 return block_limit
- abs_offset
;
1641 if (st
->frag_data
) {
1642 kunmap_skb_frag(st
->frag_data
);
1643 st
->frag_data
= NULL
;
1647 st
->stepped_offset
+= frag
->size
;
1650 if (st
->cur_skb
->next
) {
1651 st
->cur_skb
= st
->cur_skb
->next
;
1654 } else if (st
->root_skb
== st
->cur_skb
&&
1655 skb_shinfo(st
->root_skb
)->frag_list
) {
1656 st
->cur_skb
= skb_shinfo(st
->root_skb
)->frag_list
;
1664 * skb_abort_seq_read - Abort a sequential read of skb data
1665 * @st: state variable
1667 * Must be called if skb_seq_read() was not called until it
1670 void skb_abort_seq_read(struct skb_seq_state
*st
)
1673 kunmap_skb_frag(st
->frag_data
);
1676 #define TS_SKB_CB(state) ((struct skb_seq_state *) &((state)->cb))
1678 static unsigned int skb_ts_get_next_block(unsigned int offset
, const u8
**text
,
1679 struct ts_config
*conf
,
1680 struct ts_state
*state
)
1682 return skb_seq_read(offset
, text
, TS_SKB_CB(state
));
1685 static void skb_ts_finish(struct ts_config
*conf
, struct ts_state
*state
)
1687 skb_abort_seq_read(TS_SKB_CB(state
));
1691 * skb_find_text - Find a text pattern in skb data
1692 * @skb: the buffer to look in
1693 * @from: search offset
1695 * @config: textsearch configuration
1696 * @state: uninitialized textsearch state variable
1698 * Finds a pattern in the skb data according to the specified
1699 * textsearch configuration. Use textsearch_next() to retrieve
1700 * subsequent occurrences of the pattern. Returns the offset
1701 * to the first occurrence or UINT_MAX if no match was found.
1703 unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
1704 unsigned int to
, struct ts_config
*config
,
1705 struct ts_state
*state
)
1707 config
->get_next_block
= skb_ts_get_next_block
;
1708 config
->finish
= skb_ts_finish
;
1710 skb_prepare_seq_read(skb
, from
, to
, TS_SKB_CB(state
));
1712 return textsearch_find(config
, state
);
1716 * skb_append_datato_frags: - append the user data to a skb
1717 * @sk: sock structure
1718 * @skb: skb structure to be appened with user data.
1719 * @getfrag: call back function to be used for getting the user data
1720 * @from: pointer to user message iov
1721 * @length: length of the iov message
1723 * Description: This procedure append the user data in the fragment part
1724 * of the skb if any page alloc fails user this procedure returns -ENOMEM
1726 int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
1727 int (*getfrag
)(void *from
, char *to
, int offset
,
1728 int len
, int odd
, struct sk_buff
*skb
),
1729 void *from
, int length
)
1732 skb_frag_t
*frag
= NULL
;
1733 struct page
*page
= NULL
;
1739 /* Return error if we don't have space for new frag */
1740 frg_cnt
= skb_shinfo(skb
)->nr_frags
;
1741 if (frg_cnt
>= MAX_SKB_FRAGS
)
1744 /* allocate a new page for next frag */
1745 page
= alloc_pages(sk
->sk_allocation
, 0);
1747 /* If alloc_page fails just return failure and caller will
1748 * free previous allocated pages by doing kfree_skb()
1753 /* initialize the next frag */
1754 sk
->sk_sndmsg_page
= page
;
1755 sk
->sk_sndmsg_off
= 0;
1756 skb_fill_page_desc(skb
, frg_cnt
, page
, 0, 0);
1757 skb
->truesize
+= PAGE_SIZE
;
1758 atomic_add(PAGE_SIZE
, &sk
->sk_wmem_alloc
);
1760 /* get the new initialized frag */
1761 frg_cnt
= skb_shinfo(skb
)->nr_frags
;
1762 frag
= &skb_shinfo(skb
)->frags
[frg_cnt
- 1];
1764 /* copy the user data to page */
1765 left
= PAGE_SIZE
- frag
->page_offset
;
1766 copy
= (length
> left
)? left
: length
;
1768 ret
= getfrag(from
, (page_address(frag
->page
) +
1769 frag
->page_offset
+ frag
->size
),
1770 offset
, copy
, 0, skb
);
1774 /* copy was successful so update the size parameters */
1775 sk
->sk_sndmsg_off
+= copy
;
1778 skb
->data_len
+= copy
;
1782 } while (length
> 0);
1787 void __init
skb_init(void)
1789 skbuff_head_cache
= kmem_cache_create("skbuff_head_cache",
1790 sizeof(struct sk_buff
),
1794 if (!skbuff_head_cache
)
1795 panic("cannot create skbuff cache");
1797 skbuff_fclone_cache
= kmem_cache_create("skbuff_fclone_cache",
1798 (2*sizeof(struct sk_buff
)) +
1803 if (!skbuff_fclone_cache
)
1804 panic("cannot create skbuff cache");
1807 EXPORT_SYMBOL(___pskb_trim
);
1808 EXPORT_SYMBOL(__kfree_skb
);
1809 EXPORT_SYMBOL(__pskb_pull_tail
);
1810 EXPORT_SYMBOL(__alloc_skb
);
1811 EXPORT_SYMBOL(pskb_copy
);
1812 EXPORT_SYMBOL(pskb_expand_head
);
1813 EXPORT_SYMBOL(skb_checksum
);
1814 EXPORT_SYMBOL(skb_clone
);
1815 EXPORT_SYMBOL(skb_clone_fraglist
);
1816 EXPORT_SYMBOL(skb_copy
);
1817 EXPORT_SYMBOL(skb_copy_and_csum_bits
);
1818 EXPORT_SYMBOL(skb_copy_and_csum_dev
);
1819 EXPORT_SYMBOL(skb_copy_bits
);
1820 EXPORT_SYMBOL(skb_copy_expand
);
1821 EXPORT_SYMBOL(skb_over_panic
);
1822 EXPORT_SYMBOL(skb_pad
);
1823 EXPORT_SYMBOL(skb_realloc_headroom
);
1824 EXPORT_SYMBOL(skb_under_panic
);
1825 EXPORT_SYMBOL(skb_dequeue
);
1826 EXPORT_SYMBOL(skb_dequeue_tail
);
1827 EXPORT_SYMBOL(skb_insert
);
1828 EXPORT_SYMBOL(skb_queue_purge
);
1829 EXPORT_SYMBOL(skb_queue_head
);
1830 EXPORT_SYMBOL(skb_queue_tail
);
1831 EXPORT_SYMBOL(skb_unlink
);
1832 EXPORT_SYMBOL(skb_append
);
1833 EXPORT_SYMBOL(skb_split
);
1834 EXPORT_SYMBOL(skb_prepare_seq_read
);
1835 EXPORT_SYMBOL(skb_seq_read
);
1836 EXPORT_SYMBOL(skb_abort_seq_read
);
1837 EXPORT_SYMBOL(skb_find_text
);
1838 EXPORT_SYMBOL(skb_append_datato_frags
);