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
,
143 skb
= kmem_cache_alloc(skbuff_fclone_cache
,
144 gfp_mask
& ~__GFP_DMA
);
146 skb
= kmem_cache_alloc(skbuff_head_cache
,
147 gfp_mask
& ~__GFP_DMA
);
152 /* Get the DATA. Size must match skb_add_mtu(). */
153 size
= SKB_DATA_ALIGN(size
);
154 data
= kmalloc(size
+ sizeof(struct skb_shared_info
), gfp_mask
);
158 memset(skb
, 0, offsetof(struct sk_buff
, truesize
));
159 skb
->truesize
= size
+ sizeof(struct sk_buff
);
160 atomic_set(&skb
->users
, 1);
164 skb
->end
= data
+ size
;
166 struct sk_buff
*child
= skb
+ 1;
167 atomic_t
*fclone_ref
= (atomic_t
*) (child
+ 1);
169 skb
->fclone
= SKB_FCLONE_ORIG
;
170 atomic_set(fclone_ref
, 1);
172 child
->fclone
= SKB_FCLONE_UNAVAILABLE
;
174 atomic_set(&(skb_shinfo(skb
)->dataref
), 1);
175 skb_shinfo(skb
)->nr_frags
= 0;
176 skb_shinfo(skb
)->tso_size
= 0;
177 skb_shinfo(skb
)->tso_segs
= 0;
178 skb_shinfo(skb
)->frag_list
= NULL
;
179 skb_shinfo(skb
)->ufo_size
= 0;
180 skb_shinfo(skb
)->ip6_frag_id
= 0;
184 kmem_cache_free(skbuff_head_cache
, skb
);
190 * alloc_skb_from_cache - allocate a network buffer
191 * @cp: kmem_cache from which to allocate the data area
192 * (object size must be big enough for @size bytes + skb overheads)
193 * @size: size to allocate
194 * @gfp_mask: allocation mask
196 * Allocate a new &sk_buff. The returned buffer has no headroom and
197 * tail room of size bytes. The object has a reference count of one.
198 * The return is the buffer. On a failure the return is %NULL.
200 * Buffers may only be allocated from interrupts using a @gfp_mask of
203 struct sk_buff
*alloc_skb_from_cache(kmem_cache_t
*cp
,
211 skb
= kmem_cache_alloc(skbuff_head_cache
,
212 gfp_mask
& ~__GFP_DMA
);
217 size
= SKB_DATA_ALIGN(size
);
218 data
= kmem_cache_alloc(cp
, gfp_mask
);
222 memset(skb
, 0, offsetof(struct sk_buff
, truesize
));
223 skb
->truesize
= size
+ sizeof(struct sk_buff
);
224 atomic_set(&skb
->users
, 1);
228 skb
->end
= data
+ size
;
230 atomic_set(&(skb_shinfo(skb
)->dataref
), 1);
231 skb_shinfo(skb
)->nr_frags
= 0;
232 skb_shinfo(skb
)->tso_size
= 0;
233 skb_shinfo(skb
)->tso_segs
= 0;
234 skb_shinfo(skb
)->frag_list
= NULL
;
238 kmem_cache_free(skbuff_head_cache
, skb
);
244 static void skb_drop_fraglist(struct sk_buff
*skb
)
246 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
248 skb_shinfo(skb
)->frag_list
= NULL
;
251 struct sk_buff
*this = list
;
257 static void skb_clone_fraglist(struct sk_buff
*skb
)
259 struct sk_buff
*list
;
261 for (list
= skb_shinfo(skb
)->frag_list
; list
; list
= list
->next
)
265 void skb_release_data(struct sk_buff
*skb
)
268 !atomic_sub_return(skb
->nohdr
? (1 << SKB_DATAREF_SHIFT
) + 1 : 1,
269 &skb_shinfo(skb
)->dataref
)) {
270 if (skb_shinfo(skb
)->nr_frags
) {
272 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++)
273 put_page(skb_shinfo(skb
)->frags
[i
].page
);
276 if (skb_shinfo(skb
)->frag_list
)
277 skb_drop_fraglist(skb
);
284 * Free an skbuff by memory without cleaning the state.
286 void kfree_skbmem(struct sk_buff
*skb
)
288 struct sk_buff
*other
;
289 atomic_t
*fclone_ref
;
291 skb_release_data(skb
);
292 switch (skb
->fclone
) {
293 case SKB_FCLONE_UNAVAILABLE
:
294 kmem_cache_free(skbuff_head_cache
, skb
);
297 case SKB_FCLONE_ORIG
:
298 fclone_ref
= (atomic_t
*) (skb
+ 2);
299 if (atomic_dec_and_test(fclone_ref
))
300 kmem_cache_free(skbuff_fclone_cache
, skb
);
303 case SKB_FCLONE_CLONE
:
304 fclone_ref
= (atomic_t
*) (skb
+ 1);
307 /* The clone portion is available for
308 * fast-cloning again.
310 skb
->fclone
= SKB_FCLONE_UNAVAILABLE
;
312 if (atomic_dec_and_test(fclone_ref
))
313 kmem_cache_free(skbuff_fclone_cache
, other
);
319 * __kfree_skb - private function
322 * Free an sk_buff. Release anything attached to the buffer.
323 * Clean the state. This is an internal helper function. Users should
324 * always call kfree_skb
327 void __kfree_skb(struct sk_buff
*skb
)
329 dst_release(skb
->dst
);
331 secpath_put(skb
->sp
);
333 if (skb
->destructor
) {
335 skb
->destructor(skb
);
337 #ifdef CONFIG_NETFILTER
338 nf_conntrack_put(skb
->nfct
);
339 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
340 nf_conntrack_put_reasm(skb
->nfct_reasm
);
342 #ifdef CONFIG_BRIDGE_NETFILTER
343 nf_bridge_put(skb
->nf_bridge
);
346 /* XXX: IS this still necessary? - JHS */
347 #ifdef CONFIG_NET_SCHED
349 #ifdef CONFIG_NET_CLS_ACT
358 * skb_clone - duplicate an sk_buff
359 * @skb: buffer to clone
360 * @gfp_mask: allocation priority
362 * Duplicate an &sk_buff. The new one is not owned by a socket. Both
363 * copies share the same packet data but not structure. The new
364 * buffer has a reference count of 1. If the allocation fails the
365 * function returns %NULL otherwise the new buffer is returned.
367 * If this function is called from an interrupt gfp_mask() must be
371 struct sk_buff
*skb_clone(struct sk_buff
*skb
, gfp_t gfp_mask
)
376 if (skb
->fclone
== SKB_FCLONE_ORIG
&&
377 n
->fclone
== SKB_FCLONE_UNAVAILABLE
) {
378 atomic_t
*fclone_ref
= (atomic_t
*) (n
+ 1);
379 n
->fclone
= SKB_FCLONE_CLONE
;
380 atomic_inc(fclone_ref
);
382 n
= kmem_cache_alloc(skbuff_head_cache
, gfp_mask
);
385 n
->fclone
= SKB_FCLONE_UNAVAILABLE
;
388 #define C(x) n->x = skb->x
390 n
->next
= n
->prev
= NULL
;
401 secpath_get(skb
->sp
);
403 memcpy(n
->cb
, skb
->cb
, sizeof(skb
->cb
));
414 n
->destructor
= NULL
;
415 #ifdef CONFIG_NETFILTER
418 nf_conntrack_get(skb
->nfct
);
420 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
422 nf_conntrack_get_reasm(skb
->nfct_reasm
);
424 #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
427 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
429 nf_conntrack_get_reasm(skb
->nfct_reasm
);
431 #ifdef CONFIG_BRIDGE_NETFILTER
433 nf_bridge_get(skb
->nf_bridge
);
435 #endif /*CONFIG_NETFILTER*/
436 #ifdef CONFIG_NET_SCHED
438 #ifdef CONFIG_NET_CLS_ACT
439 n
->tc_verd
= SET_TC_VERD(skb
->tc_verd
,0);
440 n
->tc_verd
= CLR_TC_OK2MUNGE(n
->tc_verd
);
441 n
->tc_verd
= CLR_TC_MUNGED(n
->tc_verd
);
447 atomic_set(&n
->users
, 1);
453 atomic_inc(&(skb_shinfo(skb
)->dataref
));
459 static void copy_skb_header(struct sk_buff
*new, const struct sk_buff
*old
)
462 * Shift between the two data areas in bytes
464 unsigned long offset
= new->data
- old
->data
;
468 new->priority
= old
->priority
;
469 new->protocol
= old
->protocol
;
470 new->dst
= dst_clone(old
->dst
);
472 new->sp
= secpath_get(old
->sp
);
474 new->h
.raw
= old
->h
.raw
+ offset
;
475 new->nh
.raw
= old
->nh
.raw
+ offset
;
476 new->mac
.raw
= old
->mac
.raw
+ offset
;
477 memcpy(new->cb
, old
->cb
, sizeof(old
->cb
));
478 new->local_df
= old
->local_df
;
479 new->fclone
= SKB_FCLONE_UNAVAILABLE
;
480 new->pkt_type
= old
->pkt_type
;
481 new->tstamp
= old
->tstamp
;
482 new->destructor
= NULL
;
483 #ifdef CONFIG_NETFILTER
484 new->nfmark
= old
->nfmark
;
485 new->nfct
= old
->nfct
;
486 nf_conntrack_get(old
->nfct
);
487 new->nfctinfo
= old
->nfctinfo
;
488 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
489 new->nfct_reasm
= old
->nfct_reasm
;
490 nf_conntrack_get_reasm(old
->nfct_reasm
);
492 #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
493 new->ipvs_property
= old
->ipvs_property
;
495 #ifdef CONFIG_BRIDGE_NETFILTER
496 new->nf_bridge
= old
->nf_bridge
;
497 nf_bridge_get(old
->nf_bridge
);
500 #ifdef CONFIG_NET_SCHED
501 #ifdef CONFIG_NET_CLS_ACT
502 new->tc_verd
= old
->tc_verd
;
504 new->tc_index
= old
->tc_index
;
506 atomic_set(&new->users
, 1);
507 skb_shinfo(new)->tso_size
= skb_shinfo(old
)->tso_size
;
508 skb_shinfo(new)->tso_segs
= skb_shinfo(old
)->tso_segs
;
512 * skb_copy - create private copy of an sk_buff
513 * @skb: buffer to copy
514 * @gfp_mask: allocation priority
516 * Make a copy of both an &sk_buff and its data. This is used when the
517 * caller wishes to modify the data and needs a private copy of the
518 * data to alter. Returns %NULL on failure or the pointer to the buffer
519 * on success. The returned buffer has a reference count of 1.
521 * As by-product this function converts non-linear &sk_buff to linear
522 * one, so that &sk_buff becomes completely private and caller is allowed
523 * to modify all the data of returned buffer. This means that this
524 * function is not recommended for use in circumstances when only
525 * header is going to be modified. Use pskb_copy() instead.
528 struct sk_buff
*skb_copy(const struct sk_buff
*skb
, gfp_t gfp_mask
)
530 int headerlen
= skb
->data
- skb
->head
;
532 * Allocate the copy buffer
534 struct sk_buff
*n
= alloc_skb(skb
->end
- skb
->head
+ skb
->data_len
,
539 /* Set the data pointer */
540 skb_reserve(n
, headerlen
);
541 /* Set the tail pointer and length */
542 skb_put(n
, skb
->len
);
544 n
->ip_summed
= skb
->ip_summed
;
546 if (skb_copy_bits(skb
, -headerlen
, n
->head
, headerlen
+ skb
->len
))
549 copy_skb_header(n
, skb
);
555 * pskb_copy - create copy of an sk_buff with private head.
556 * @skb: buffer to copy
557 * @gfp_mask: allocation priority
559 * Make a copy of both an &sk_buff and part of its data, located
560 * in header. Fragmented data remain shared. This is used when
561 * the caller wishes to modify only header of &sk_buff and needs
562 * private copy of the header to alter. Returns %NULL on failure
563 * or the pointer to the buffer on success.
564 * The returned buffer has a reference count of 1.
567 struct sk_buff
*pskb_copy(struct sk_buff
*skb
, gfp_t gfp_mask
)
570 * Allocate the copy buffer
572 struct sk_buff
*n
= alloc_skb(skb
->end
- skb
->head
, gfp_mask
);
577 /* Set the data pointer */
578 skb_reserve(n
, skb
->data
- skb
->head
);
579 /* Set the tail pointer and length */
580 skb_put(n
, skb_headlen(skb
));
582 memcpy(n
->data
, skb
->data
, n
->len
);
584 n
->ip_summed
= skb
->ip_summed
;
586 n
->data_len
= skb
->data_len
;
589 if (skb_shinfo(skb
)->nr_frags
) {
592 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
593 skb_shinfo(n
)->frags
[i
] = skb_shinfo(skb
)->frags
[i
];
594 get_page(skb_shinfo(n
)->frags
[i
].page
);
596 skb_shinfo(n
)->nr_frags
= i
;
599 if (skb_shinfo(skb
)->frag_list
) {
600 skb_shinfo(n
)->frag_list
= skb_shinfo(skb
)->frag_list
;
601 skb_clone_fraglist(n
);
604 copy_skb_header(n
, skb
);
610 * pskb_expand_head - reallocate header of &sk_buff
611 * @skb: buffer to reallocate
612 * @nhead: room to add at head
613 * @ntail: room to add at tail
614 * @gfp_mask: allocation priority
616 * Expands (or creates identical copy, if &nhead and &ntail are zero)
617 * header of skb. &sk_buff itself is not changed. &sk_buff MUST have
618 * reference count of 1. Returns zero in the case of success or error,
619 * if expansion failed. In the last case, &sk_buff is not changed.
621 * All the pointers pointing into skb header may change and must be
622 * reloaded after call to this function.
625 int pskb_expand_head(struct sk_buff
*skb
, int nhead
, int ntail
,
630 int size
= nhead
+ (skb
->end
- skb
->head
) + ntail
;
636 size
= SKB_DATA_ALIGN(size
);
638 data
= kmalloc(size
+ sizeof(struct skb_shared_info
), gfp_mask
);
642 /* Copy only real data... and, alas, header. This should be
643 * optimized for the cases when header is void. */
644 memcpy(data
+ nhead
, skb
->head
, skb
->tail
- skb
->head
);
645 memcpy(data
+ size
, skb
->end
, sizeof(struct skb_shared_info
));
647 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++)
648 get_page(skb_shinfo(skb
)->frags
[i
].page
);
650 if (skb_shinfo(skb
)->frag_list
)
651 skb_clone_fraglist(skb
);
653 skb_release_data(skb
);
655 off
= (data
+ nhead
) - skb
->head
;
658 skb
->end
= data
+ size
;
666 atomic_set(&skb_shinfo(skb
)->dataref
, 1);
673 /* Make private copy of skb with writable head and some headroom */
675 struct sk_buff
*skb_realloc_headroom(struct sk_buff
*skb
, unsigned int headroom
)
677 struct sk_buff
*skb2
;
678 int delta
= headroom
- skb_headroom(skb
);
681 skb2
= pskb_copy(skb
, GFP_ATOMIC
);
683 skb2
= skb_clone(skb
, GFP_ATOMIC
);
684 if (skb2
&& pskb_expand_head(skb2
, SKB_DATA_ALIGN(delta
), 0,
695 * skb_copy_expand - copy and expand sk_buff
696 * @skb: buffer to copy
697 * @newheadroom: new free bytes at head
698 * @newtailroom: new free bytes at tail
699 * @gfp_mask: allocation priority
701 * Make a copy of both an &sk_buff and its data and while doing so
702 * allocate additional space.
704 * This is used when the caller wishes to modify the data and needs a
705 * private copy of the data to alter as well as more space for new fields.
706 * Returns %NULL on failure or the pointer to the buffer
707 * on success. The returned buffer has a reference count of 1.
709 * You must pass %GFP_ATOMIC as the allocation priority if this function
710 * is called from an interrupt.
712 * BUG ALERT: ip_summed is not copied. Why does this work? Is it used
713 * only by netfilter in the cases when checksum is recalculated? --ANK
715 struct sk_buff
*skb_copy_expand(const struct sk_buff
*skb
,
716 int newheadroom
, int newtailroom
,
720 * Allocate the copy buffer
722 struct sk_buff
*n
= alloc_skb(newheadroom
+ skb
->len
+ newtailroom
,
724 int head_copy_len
, head_copy_off
;
729 skb_reserve(n
, newheadroom
);
731 /* Set the tail pointer and length */
732 skb_put(n
, skb
->len
);
734 head_copy_len
= skb_headroom(skb
);
736 if (newheadroom
<= head_copy_len
)
737 head_copy_len
= newheadroom
;
739 head_copy_off
= newheadroom
- head_copy_len
;
741 /* Copy the linear header and data. */
742 if (skb_copy_bits(skb
, -head_copy_len
, n
->head
+ head_copy_off
,
743 skb
->len
+ head_copy_len
))
746 copy_skb_header(n
, skb
);
752 * skb_pad - zero pad the tail of an skb
753 * @skb: buffer to pad
756 * Ensure that a buffer is followed by a padding area that is zero
757 * filled. Used by network drivers which may DMA or transfer data
758 * beyond the buffer end onto the wire.
760 * May return NULL in out of memory cases.
763 struct sk_buff
*skb_pad(struct sk_buff
*skb
, int pad
)
765 struct sk_buff
*nskb
;
767 /* If the skbuff is non linear tailroom is always zero.. */
768 if (skb_tailroom(skb
) >= pad
) {
769 memset(skb
->data
+skb
->len
, 0, pad
);
773 nskb
= skb_copy_expand(skb
, skb_headroom(skb
), skb_tailroom(skb
) + pad
, GFP_ATOMIC
);
776 memset(nskb
->data
+nskb
->len
, 0, pad
);
780 /* Trims skb to length len. It can change skb pointers, if "realloc" is 1.
781 * If realloc==0 and trimming is impossible without change of data,
785 int ___pskb_trim(struct sk_buff
*skb
, unsigned int len
, int realloc
)
787 int offset
= skb_headlen(skb
);
788 int nfrags
= skb_shinfo(skb
)->nr_frags
;
791 for (i
= 0; i
< nfrags
; i
++) {
792 int end
= offset
+ skb_shinfo(skb
)->frags
[i
].size
;
794 if (skb_cloned(skb
)) {
797 if (pskb_expand_head(skb
, 0, 0, GFP_ATOMIC
))
801 put_page(skb_shinfo(skb
)->frags
[i
].page
);
802 skb_shinfo(skb
)->nr_frags
--;
804 skb_shinfo(skb
)->frags
[i
].size
= len
- offset
;
811 skb
->data_len
-= skb
->len
- len
;
814 if (len
<= skb_headlen(skb
)) {
817 skb
->tail
= skb
->data
+ len
;
818 if (skb_shinfo(skb
)->frag_list
&& !skb_cloned(skb
))
819 skb_drop_fraglist(skb
);
821 skb
->data_len
-= skb
->len
- len
;
830 * __pskb_pull_tail - advance tail of skb header
831 * @skb: buffer to reallocate
832 * @delta: number of bytes to advance tail
834 * The function makes a sense only on a fragmented &sk_buff,
835 * it expands header moving its tail forward and copying necessary
836 * data from fragmented part.
838 * &sk_buff MUST have reference count of 1.
840 * Returns %NULL (and &sk_buff does not change) if pull failed
841 * or value of new tail of skb in the case of success.
843 * All the pointers pointing into skb header may change and must be
844 * reloaded after call to this function.
847 /* Moves tail of skb head forward, copying data from fragmented part,
848 * when it is necessary.
849 * 1. It may fail due to malloc failure.
850 * 2. It may change skb pointers.
852 * It is pretty complicated. Luckily, it is called only in exceptional cases.
854 unsigned char *__pskb_pull_tail(struct sk_buff
*skb
, int delta
)
856 /* If skb has not enough free space at tail, get new one
857 * plus 128 bytes for future expansions. If we have enough
858 * room at tail, reallocate without expansion only if skb is cloned.
860 int i
, k
, eat
= (skb
->tail
+ delta
) - skb
->end
;
862 if (eat
> 0 || skb_cloned(skb
)) {
863 if (pskb_expand_head(skb
, 0, eat
> 0 ? eat
+ 128 : 0,
868 if (skb_copy_bits(skb
, skb_headlen(skb
), skb
->tail
, delta
))
871 /* Optimization: no fragments, no reasons to preestimate
872 * size of pulled pages. Superb.
874 if (!skb_shinfo(skb
)->frag_list
)
877 /* Estimate size of pulled pages. */
879 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
880 if (skb_shinfo(skb
)->frags
[i
].size
>= eat
)
882 eat
-= skb_shinfo(skb
)->frags
[i
].size
;
885 /* If we need update frag list, we are in troubles.
886 * Certainly, it possible to add an offset to skb data,
887 * but taking into account that pulling is expected to
888 * be very rare operation, it is worth to fight against
889 * further bloating skb head and crucify ourselves here instead.
890 * Pure masohism, indeed. 8)8)
893 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
894 struct sk_buff
*clone
= NULL
;
895 struct sk_buff
*insp
= NULL
;
901 if (list
->len
<= eat
) {
902 /* Eaten as whole. */
907 /* Eaten partially. */
909 if (skb_shared(list
)) {
910 /* Sucks! We need to fork list. :-( */
911 clone
= skb_clone(list
, GFP_ATOMIC
);
917 /* This may be pulled without
921 if (!pskb_pull(list
, eat
)) {
930 /* Free pulled out fragments. */
931 while ((list
= skb_shinfo(skb
)->frag_list
) != insp
) {
932 skb_shinfo(skb
)->frag_list
= list
->next
;
935 /* And insert new clone at head. */
938 skb_shinfo(skb
)->frag_list
= clone
;
941 /* Success! Now we may commit changes to skb data. */
946 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
947 if (skb_shinfo(skb
)->frags
[i
].size
<= eat
) {
948 put_page(skb_shinfo(skb
)->frags
[i
].page
);
949 eat
-= skb_shinfo(skb
)->frags
[i
].size
;
951 skb_shinfo(skb
)->frags
[k
] = skb_shinfo(skb
)->frags
[i
];
953 skb_shinfo(skb
)->frags
[k
].page_offset
+= eat
;
954 skb_shinfo(skb
)->frags
[k
].size
-= eat
;
960 skb_shinfo(skb
)->nr_frags
= k
;
963 skb
->data_len
-= delta
;
968 /* Copy some data bits from skb to kernel buffer. */
970 int skb_copy_bits(const struct sk_buff
*skb
, int offset
, void *to
, int len
)
973 int start
= skb_headlen(skb
);
975 if (offset
> (int)skb
->len
- len
)
979 if ((copy
= start
- offset
) > 0) {
982 memcpy(to
, skb
->data
+ offset
, copy
);
983 if ((len
-= copy
) == 0)
989 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
992 BUG_TRAP(start
<= offset
+ len
);
994 end
= start
+ skb_shinfo(skb
)->frags
[i
].size
;
995 if ((copy
= end
- offset
) > 0) {
1001 vaddr
= kmap_skb_frag(&skb_shinfo(skb
)->frags
[i
]);
1003 vaddr
+ skb_shinfo(skb
)->frags
[i
].page_offset
+
1004 offset
- start
, copy
);
1005 kunmap_skb_frag(vaddr
);
1007 if ((len
-= copy
) == 0)
1015 if (skb_shinfo(skb
)->frag_list
) {
1016 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1018 for (; list
; list
= list
->next
) {
1021 BUG_TRAP(start
<= offset
+ len
);
1023 end
= start
+ list
->len
;
1024 if ((copy
= end
- offset
) > 0) {
1027 if (skb_copy_bits(list
, offset
- start
,
1030 if ((len
-= copy
) == 0)
1046 * skb_store_bits - store bits from kernel buffer to skb
1047 * @skb: destination buffer
1048 * @offset: offset in destination
1049 * @from: source buffer
1050 * @len: number of bytes to copy
1052 * Copy the specified number of bytes from the source buffer to the
1053 * destination skb. This function handles all the messy bits of
1054 * traversing fragment lists and such.
1057 int skb_store_bits(const struct sk_buff
*skb
, int offset
, void *from
, int len
)
1060 int start
= skb_headlen(skb
);
1062 if (offset
> (int)skb
->len
- len
)
1065 if ((copy
= start
- offset
) > 0) {
1068 memcpy(skb
->data
+ offset
, from
, copy
);
1069 if ((len
-= copy
) == 0)
1075 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1076 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1079 BUG_TRAP(start
<= offset
+ len
);
1081 end
= start
+ frag
->size
;
1082 if ((copy
= end
- offset
) > 0) {
1088 vaddr
= kmap_skb_frag(frag
);
1089 memcpy(vaddr
+ frag
->page_offset
+ offset
- start
,
1091 kunmap_skb_frag(vaddr
);
1093 if ((len
-= copy
) == 0)
1101 if (skb_shinfo(skb
)->frag_list
) {
1102 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1104 for (; list
; list
= list
->next
) {
1107 BUG_TRAP(start
<= offset
+ len
);
1109 end
= start
+ list
->len
;
1110 if ((copy
= end
- offset
) > 0) {
1113 if (skb_store_bits(list
, offset
- start
,
1116 if ((len
-= copy
) == 0)
1131 EXPORT_SYMBOL(skb_store_bits
);
1133 /* Checksum skb data. */
1135 unsigned int skb_checksum(const struct sk_buff
*skb
, int offset
,
1136 int len
, unsigned int csum
)
1138 int start
= skb_headlen(skb
);
1139 int i
, copy
= start
- offset
;
1142 /* Checksum header. */
1146 csum
= csum_partial(skb
->data
+ offset
, copy
, csum
);
1147 if ((len
-= copy
) == 0)
1153 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1156 BUG_TRAP(start
<= offset
+ len
);
1158 end
= start
+ skb_shinfo(skb
)->frags
[i
].size
;
1159 if ((copy
= end
- offset
) > 0) {
1162 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1166 vaddr
= kmap_skb_frag(frag
);
1167 csum2
= csum_partial(vaddr
+ frag
->page_offset
+
1168 offset
- start
, copy
, 0);
1169 kunmap_skb_frag(vaddr
);
1170 csum
= csum_block_add(csum
, csum2
, pos
);
1179 if (skb_shinfo(skb
)->frag_list
) {
1180 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1182 for (; list
; list
= list
->next
) {
1185 BUG_TRAP(start
<= offset
+ len
);
1187 end
= start
+ list
->len
;
1188 if ((copy
= end
- offset
) > 0) {
1192 csum2
= skb_checksum(list
, offset
- start
,
1194 csum
= csum_block_add(csum
, csum2
, pos
);
1195 if ((len
-= copy
) == 0)
1209 /* Both of above in one bottle. */
1211 unsigned int skb_copy_and_csum_bits(const struct sk_buff
*skb
, int offset
,
1212 u8
*to
, int len
, unsigned int csum
)
1214 int start
= skb_headlen(skb
);
1215 int i
, copy
= start
- offset
;
1222 csum
= csum_partial_copy_nocheck(skb
->data
+ offset
, to
,
1224 if ((len
-= copy
) == 0)
1231 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++) {
1234 BUG_TRAP(start
<= offset
+ len
);
1236 end
= start
+ skb_shinfo(skb
)->frags
[i
].size
;
1237 if ((copy
= end
- offset
) > 0) {
1240 skb_frag_t
*frag
= &skb_shinfo(skb
)->frags
[i
];
1244 vaddr
= kmap_skb_frag(frag
);
1245 csum2
= csum_partial_copy_nocheck(vaddr
+
1249 kunmap_skb_frag(vaddr
);
1250 csum
= csum_block_add(csum
, csum2
, pos
);
1260 if (skb_shinfo(skb
)->frag_list
) {
1261 struct sk_buff
*list
= skb_shinfo(skb
)->frag_list
;
1263 for (; list
; list
= list
->next
) {
1267 BUG_TRAP(start
<= offset
+ len
);
1269 end
= start
+ list
->len
;
1270 if ((copy
= end
- offset
) > 0) {
1273 csum2
= skb_copy_and_csum_bits(list
,
1276 csum
= csum_block_add(csum
, csum2
, pos
);
1277 if ((len
-= copy
) == 0)
1291 void skb_copy_and_csum_dev(const struct sk_buff
*skb
, u8
*to
)
1296 if (skb
->ip_summed
== CHECKSUM_HW
)
1297 csstart
= skb
->h
.raw
- skb
->data
;
1299 csstart
= skb_headlen(skb
);
1301 if (csstart
> skb_headlen(skb
))
1304 memcpy(to
, skb
->data
, csstart
);
1307 if (csstart
!= skb
->len
)
1308 csum
= skb_copy_and_csum_bits(skb
, csstart
, to
+ csstart
,
1309 skb
->len
- csstart
, 0);
1311 if (skb
->ip_summed
== CHECKSUM_HW
) {
1312 long csstuff
= csstart
+ skb
->csum
;
1314 *((unsigned short *)(to
+ csstuff
)) = csum_fold(csum
);
1319 * skb_dequeue - remove from the head of the queue
1320 * @list: list to dequeue from
1322 * Remove the head of the list. The list lock is taken so the function
1323 * may be used safely with other locking list functions. The head item is
1324 * returned or %NULL if the list is empty.
1327 struct sk_buff
*skb_dequeue(struct sk_buff_head
*list
)
1329 unsigned long flags
;
1330 struct sk_buff
*result
;
1332 spin_lock_irqsave(&list
->lock
, flags
);
1333 result
= __skb_dequeue(list
);
1334 spin_unlock_irqrestore(&list
->lock
, flags
);
1339 * skb_dequeue_tail - remove from the tail of the queue
1340 * @list: list to dequeue from
1342 * Remove the tail of the list. The list lock is taken so the function
1343 * may be used safely with other locking list functions. The tail item is
1344 * returned or %NULL if the list is empty.
1346 struct sk_buff
*skb_dequeue_tail(struct sk_buff_head
*list
)
1348 unsigned long flags
;
1349 struct sk_buff
*result
;
1351 spin_lock_irqsave(&list
->lock
, flags
);
1352 result
= __skb_dequeue_tail(list
);
1353 spin_unlock_irqrestore(&list
->lock
, flags
);
1358 * skb_queue_purge - empty a list
1359 * @list: list to empty
1361 * Delete all buffers on an &sk_buff list. Each buffer is removed from
1362 * the list and one reference dropped. This function takes the list
1363 * lock and is atomic with respect to other list locking functions.
1365 void skb_queue_purge(struct sk_buff_head
*list
)
1367 struct sk_buff
*skb
;
1368 while ((skb
= skb_dequeue(list
)) != NULL
)
1373 * skb_queue_head - queue a buffer at the list head
1374 * @list: list to use
1375 * @newsk: buffer to queue
1377 * Queue a buffer at the start of the list. This function takes the
1378 * list lock and can be used safely with other locking &sk_buff functions
1381 * A buffer cannot be placed on two lists at the same time.
1383 void skb_queue_head(struct sk_buff_head
*list
, struct sk_buff
*newsk
)
1385 unsigned long flags
;
1387 spin_lock_irqsave(&list
->lock
, flags
);
1388 __skb_queue_head(list
, newsk
);
1389 spin_unlock_irqrestore(&list
->lock
, flags
);
1393 * skb_queue_tail - queue a buffer at the list tail
1394 * @list: list to use
1395 * @newsk: buffer to queue
1397 * Queue a buffer at the tail of the list. This function takes the
1398 * list lock and can be used safely with other locking &sk_buff functions
1401 * A buffer cannot be placed on two lists at the same time.
1403 void skb_queue_tail(struct sk_buff_head
*list
, struct sk_buff
*newsk
)
1405 unsigned long flags
;
1407 spin_lock_irqsave(&list
->lock
, flags
);
1408 __skb_queue_tail(list
, newsk
);
1409 spin_unlock_irqrestore(&list
->lock
, flags
);
1413 * skb_unlink - remove a buffer from a list
1414 * @skb: buffer to remove
1415 * @list: list to use
1417 * Remove a packet from a list. The list locks are taken and this
1418 * function is atomic with respect to other list locked calls
1420 * You must know what list the SKB is on.
1422 void skb_unlink(struct sk_buff
*skb
, struct sk_buff_head
*list
)
1424 unsigned long flags
;
1426 spin_lock_irqsave(&list
->lock
, flags
);
1427 __skb_unlink(skb
, list
);
1428 spin_unlock_irqrestore(&list
->lock
, flags
);
1432 * skb_append - append a buffer
1433 * @old: buffer to insert after
1434 * @newsk: buffer to insert
1435 * @list: list to use
1437 * Place a packet after a given packet in a list. The list locks are taken
1438 * and this function is atomic with respect to other list locked calls.
1439 * A buffer cannot be placed on two lists at the same time.
1441 void skb_append(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
)
1443 unsigned long flags
;
1445 spin_lock_irqsave(&list
->lock
, flags
);
1446 __skb_append(old
, newsk
, list
);
1447 spin_unlock_irqrestore(&list
->lock
, flags
);
1452 * skb_insert - insert a buffer
1453 * @old: buffer to insert before
1454 * @newsk: buffer to insert
1455 * @list: list to use
1457 * Place a packet before a given packet in a list. The list locks are
1458 * taken and this function is atomic with respect to other list locked
1461 * A buffer cannot be placed on two lists at the same time.
1463 void skb_insert(struct sk_buff
*old
, struct sk_buff
*newsk
, struct sk_buff_head
*list
)
1465 unsigned long flags
;
1467 spin_lock_irqsave(&list
->lock
, flags
);
1468 __skb_insert(newsk
, old
->prev
, old
, list
);
1469 spin_unlock_irqrestore(&list
->lock
, flags
);
1474 * Tune the memory allocator for a new MTU size.
1476 void skb_add_mtu(int mtu
)
1478 /* Must match allocation in alloc_skb */
1479 mtu
= SKB_DATA_ALIGN(mtu
) + sizeof(struct skb_shared_info
);
1481 kmem_add_cache_size(mtu
);
1485 static inline void skb_split_inside_header(struct sk_buff
*skb
,
1486 struct sk_buff
* skb1
,
1487 const u32 len
, const int pos
)
1491 memcpy(skb_put(skb1
, pos
- len
), skb
->data
+ len
, pos
- len
);
1493 /* And move data appendix as is. */
1494 for (i
= 0; i
< skb_shinfo(skb
)->nr_frags
; i
++)
1495 skb_shinfo(skb1
)->frags
[i
] = skb_shinfo(skb
)->frags
[i
];
1497 skb_shinfo(skb1
)->nr_frags
= skb_shinfo(skb
)->nr_frags
;
1498 skb_shinfo(skb
)->nr_frags
= 0;
1499 skb1
->data_len
= skb
->data_len
;
1500 skb1
->len
+= skb1
->data_len
;
1503 skb
->tail
= skb
->data
+ len
;
1506 static inline void skb_split_no_header(struct sk_buff
*skb
,
1507 struct sk_buff
* skb1
,
1508 const u32 len
, int pos
)
1511 const int nfrags
= skb_shinfo(skb
)->nr_frags
;
1513 skb_shinfo(skb
)->nr_frags
= 0;
1514 skb1
->len
= skb1
->data_len
= skb
->len
- len
;
1516 skb
->data_len
= len
- pos
;
1518 for (i
= 0; i
< nfrags
; i
++) {
1519 int size
= skb_shinfo(skb
)->frags
[i
].size
;
1521 if (pos
+ size
> len
) {
1522 skb_shinfo(skb1
)->frags
[k
] = skb_shinfo(skb
)->frags
[i
];
1526 * We have two variants in this case:
1527 * 1. Move all the frag to the second
1528 * part, if it is possible. F.e.
1529 * this approach is mandatory for TUX,
1530 * where splitting is expensive.
1531 * 2. Split is accurately. We make this.
1533 get_page(skb_shinfo(skb
)->frags
[i
].page
);
1534 skb_shinfo(skb1
)->frags
[0].page_offset
+= len
- pos
;
1535 skb_shinfo(skb1
)->frags
[0].size
-= len
- pos
;
1536 skb_shinfo(skb
)->frags
[i
].size
= len
- pos
;
1537 skb_shinfo(skb
)->nr_frags
++;
1541 skb_shinfo(skb
)->nr_frags
++;
1544 skb_shinfo(skb1
)->nr_frags
= k
;
1548 * skb_split - Split fragmented skb to two parts at length len.
1549 * @skb: the buffer to split
1550 * @skb1: the buffer to receive the second part
1551 * @len: new length for skb
1553 void skb_split(struct sk_buff
*skb
, struct sk_buff
*skb1
, const u32 len
)
1555 int pos
= skb_headlen(skb
);
1557 if (len
< pos
) /* Split line is inside header. */
1558 skb_split_inside_header(skb
, skb1
, len
, pos
);
1559 else /* Second chunk has no header, nothing to copy. */
1560 skb_split_no_header(skb
, skb1
, len
, pos
);
1564 * skb_prepare_seq_read - Prepare a sequential read of skb data
1565 * @skb: the buffer to read
1566 * @from: lower offset of data to be read
1567 * @to: upper offset of data to be read
1568 * @st: state variable
1570 * Initializes the specified state variable. Must be called before
1571 * invoking skb_seq_read() for the first time.
1573 void skb_prepare_seq_read(struct sk_buff
*skb
, unsigned int from
,
1574 unsigned int to
, struct skb_seq_state
*st
)
1576 st
->lower_offset
= from
;
1577 st
->upper_offset
= to
;
1578 st
->root_skb
= st
->cur_skb
= skb
;
1579 st
->frag_idx
= st
->stepped_offset
= 0;
1580 st
->frag_data
= NULL
;
1584 * skb_seq_read - Sequentially read skb data
1585 * @consumed: number of bytes consumed by the caller so far
1586 * @data: destination pointer for data to be returned
1587 * @st: state variable
1589 * Reads a block of skb data at &consumed relative to the
1590 * lower offset specified to skb_prepare_seq_read(). Assigns
1591 * the head of the data block to &data and returns the length
1592 * of the block or 0 if the end of the skb data or the upper
1593 * offset has been reached.
1595 * The caller is not required to consume all of the data
1596 * returned, i.e. &consumed is typically set to the number
1597 * of bytes already consumed and the next call to
1598 * skb_seq_read() will return the remaining part of the block.
1600 * Note: The size of each block of data returned can be arbitary,
1601 * this limitation is the cost for zerocopy seqeuental
1602 * reads of potentially non linear data.
1604 * Note: Fragment lists within fragments are not implemented
1605 * at the moment, state->root_skb could be replaced with
1606 * a stack for this purpose.
1608 unsigned int skb_seq_read(unsigned int consumed
, const u8
**data
,
1609 struct skb_seq_state
*st
)
1611 unsigned int block_limit
, abs_offset
= consumed
+ st
->lower_offset
;
1614 if (unlikely(abs_offset
>= st
->upper_offset
))
1618 block_limit
= skb_headlen(st
->cur_skb
);
1620 if (abs_offset
< block_limit
) {
1621 *data
= st
->cur_skb
->data
+ abs_offset
;
1622 return block_limit
- abs_offset
;
1625 if (st
->frag_idx
== 0 && !st
->frag_data
)
1626 st
->stepped_offset
+= skb_headlen(st
->cur_skb
);
1628 while (st
->frag_idx
< skb_shinfo(st
->cur_skb
)->nr_frags
) {
1629 frag
= &skb_shinfo(st
->cur_skb
)->frags
[st
->frag_idx
];
1630 block_limit
= frag
->size
+ st
->stepped_offset
;
1632 if (abs_offset
< block_limit
) {
1634 st
->frag_data
= kmap_skb_frag(frag
);
1636 *data
= (u8
*) st
->frag_data
+ frag
->page_offset
+
1637 (abs_offset
- st
->stepped_offset
);
1639 return block_limit
- abs_offset
;
1642 if (st
->frag_data
) {
1643 kunmap_skb_frag(st
->frag_data
);
1644 st
->frag_data
= NULL
;
1648 st
->stepped_offset
+= frag
->size
;
1651 if (st
->cur_skb
->next
) {
1652 st
->cur_skb
= st
->cur_skb
->next
;
1655 } else if (st
->root_skb
== st
->cur_skb
&&
1656 skb_shinfo(st
->root_skb
)->frag_list
) {
1657 st
->cur_skb
= skb_shinfo(st
->root_skb
)->frag_list
;
1665 * skb_abort_seq_read - Abort a sequential read of skb data
1666 * @st: state variable
1668 * Must be called if skb_seq_read() was not called until it
1671 void skb_abort_seq_read(struct skb_seq_state
*st
)
1674 kunmap_skb_frag(st
->frag_data
);
1677 #define TS_SKB_CB(state) ((struct skb_seq_state *) &((state)->cb))
1679 static unsigned int skb_ts_get_next_block(unsigned int offset
, const u8
**text
,
1680 struct ts_config
*conf
,
1681 struct ts_state
*state
)
1683 return skb_seq_read(offset
, text
, TS_SKB_CB(state
));
1686 static void skb_ts_finish(struct ts_config
*conf
, struct ts_state
*state
)
1688 skb_abort_seq_read(TS_SKB_CB(state
));
1692 * skb_find_text - Find a text pattern in skb data
1693 * @skb: the buffer to look in
1694 * @from: search offset
1696 * @config: textsearch configuration
1697 * @state: uninitialized textsearch state variable
1699 * Finds a pattern in the skb data according to the specified
1700 * textsearch configuration. Use textsearch_next() to retrieve
1701 * subsequent occurrences of the pattern. Returns the offset
1702 * to the first occurrence or UINT_MAX if no match was found.
1704 unsigned int skb_find_text(struct sk_buff
*skb
, unsigned int from
,
1705 unsigned int to
, struct ts_config
*config
,
1706 struct ts_state
*state
)
1708 config
->get_next_block
= skb_ts_get_next_block
;
1709 config
->finish
= skb_ts_finish
;
1711 skb_prepare_seq_read(skb
, from
, to
, TS_SKB_CB(state
));
1713 return textsearch_find(config
, state
);
1717 * skb_append_datato_frags: - append the user data to a skb
1718 * @sk: sock structure
1719 * @skb: skb structure to be appened with user data.
1720 * @getfrag: call back function to be used for getting the user data
1721 * @from: pointer to user message iov
1722 * @length: length of the iov message
1724 * Description: This procedure append the user data in the fragment part
1725 * of the skb if any page alloc fails user this procedure returns -ENOMEM
1727 int skb_append_datato_frags(struct sock
*sk
, struct sk_buff
*skb
,
1728 int (*getfrag
)(void *from
, char *to
, int offset
,
1729 int len
, int odd
, struct sk_buff
*skb
),
1730 void *from
, int length
)
1733 skb_frag_t
*frag
= NULL
;
1734 struct page
*page
= NULL
;
1740 /* Return error if we don't have space for new frag */
1741 frg_cnt
= skb_shinfo(skb
)->nr_frags
;
1742 if (frg_cnt
>= MAX_SKB_FRAGS
)
1745 /* allocate a new page for next frag */
1746 page
= alloc_pages(sk
->sk_allocation
, 0);
1748 /* If alloc_page fails just return failure and caller will
1749 * free previous allocated pages by doing kfree_skb()
1754 /* initialize the next frag */
1755 sk
->sk_sndmsg_page
= page
;
1756 sk
->sk_sndmsg_off
= 0;
1757 skb_fill_page_desc(skb
, frg_cnt
, page
, 0, 0);
1758 skb
->truesize
+= PAGE_SIZE
;
1759 atomic_add(PAGE_SIZE
, &sk
->sk_wmem_alloc
);
1761 /* get the new initialized frag */
1762 frg_cnt
= skb_shinfo(skb
)->nr_frags
;
1763 frag
= &skb_shinfo(skb
)->frags
[frg_cnt
- 1];
1765 /* copy the user data to page */
1766 left
= PAGE_SIZE
- frag
->page_offset
;
1767 copy
= (length
> left
)? left
: length
;
1769 ret
= getfrag(from
, (page_address(frag
->page
) +
1770 frag
->page_offset
+ frag
->size
),
1771 offset
, copy
, 0, skb
);
1775 /* copy was successful so update the size parameters */
1776 sk
->sk_sndmsg_off
+= copy
;
1779 skb
->data_len
+= copy
;
1783 } while (length
> 0);
1788 void __init
skb_init(void)
1790 skbuff_head_cache
= kmem_cache_create("skbuff_head_cache",
1791 sizeof(struct sk_buff
),
1795 if (!skbuff_head_cache
)
1796 panic("cannot create skbuff cache");
1798 skbuff_fclone_cache
= kmem_cache_create("skbuff_fclone_cache",
1799 (2*sizeof(struct sk_buff
)) +
1804 if (!skbuff_fclone_cache
)
1805 panic("cannot create skbuff cache");
1808 EXPORT_SYMBOL(___pskb_trim
);
1809 EXPORT_SYMBOL(__kfree_skb
);
1810 EXPORT_SYMBOL(__pskb_pull_tail
);
1811 EXPORT_SYMBOL(__alloc_skb
);
1812 EXPORT_SYMBOL(pskb_copy
);
1813 EXPORT_SYMBOL(pskb_expand_head
);
1814 EXPORT_SYMBOL(skb_checksum
);
1815 EXPORT_SYMBOL(skb_clone
);
1816 EXPORT_SYMBOL(skb_clone_fraglist
);
1817 EXPORT_SYMBOL(skb_copy
);
1818 EXPORT_SYMBOL(skb_copy_and_csum_bits
);
1819 EXPORT_SYMBOL(skb_copy_and_csum_dev
);
1820 EXPORT_SYMBOL(skb_copy_bits
);
1821 EXPORT_SYMBOL(skb_copy_expand
);
1822 EXPORT_SYMBOL(skb_over_panic
);
1823 EXPORT_SYMBOL(skb_pad
);
1824 EXPORT_SYMBOL(skb_realloc_headroom
);
1825 EXPORT_SYMBOL(skb_under_panic
);
1826 EXPORT_SYMBOL(skb_dequeue
);
1827 EXPORT_SYMBOL(skb_dequeue_tail
);
1828 EXPORT_SYMBOL(skb_insert
);
1829 EXPORT_SYMBOL(skb_queue_purge
);
1830 EXPORT_SYMBOL(skb_queue_head
);
1831 EXPORT_SYMBOL(skb_queue_tail
);
1832 EXPORT_SYMBOL(skb_unlink
);
1833 EXPORT_SYMBOL(skb_append
);
1834 EXPORT_SYMBOL(skb_split
);
1835 EXPORT_SYMBOL(skb_prepare_seq_read
);
1836 EXPORT_SYMBOL(skb_seq_read
);
1837 EXPORT_SYMBOL(skb_abort_seq_read
);
1838 EXPORT_SYMBOL(skb_find_text
);
1839 EXPORT_SYMBOL(skb_append_datato_frags
);