11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * Routines having to do with the 'struct sk_buff' memory handlers. 31da177e4SLinus Torvalds * 4113aa838SAlan Cox * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk> 51da177e4SLinus Torvalds * Florian La Roche <rzsfl@rz.uni-sb.de> 61da177e4SLinus Torvalds * 71da177e4SLinus Torvalds * Fixes: 81da177e4SLinus Torvalds * Alan Cox : Fixed the worst of the load 91da177e4SLinus Torvalds * balancer bugs. 101da177e4SLinus Torvalds * Dave Platt : Interrupt stacking fix. 111da177e4SLinus Torvalds * Richard Kooijman : Timestamp fixes. 121da177e4SLinus Torvalds * Alan Cox : Changed buffer format. 131da177e4SLinus Torvalds * Alan Cox : destructor hook for AF_UNIX etc. 141da177e4SLinus Torvalds * Linus Torvalds : Better skb_clone. 151da177e4SLinus Torvalds * Alan Cox : Added skb_copy. 161da177e4SLinus Torvalds * Alan Cox : Added all the changed routines Linus 171da177e4SLinus Torvalds * only put in the headers 181da177e4SLinus Torvalds * Ray VanTassle : Fixed --skb->lock in free 191da177e4SLinus Torvalds * Alan Cox : skb_copy copy arp field 201da177e4SLinus Torvalds * Andi Kleen : slabified it. 211da177e4SLinus Torvalds * Robert Olsson : Removed skb_head_pool 221da177e4SLinus Torvalds * 231da177e4SLinus Torvalds * NOTE: 241da177e4SLinus Torvalds * The __skb_ routines should be called with interrupts 251da177e4SLinus Torvalds * disabled, or you better be *real* sure that the operation is atomic 261da177e4SLinus Torvalds * with respect to whatever list is being frobbed (e.g. via lock_sock() 271da177e4SLinus Torvalds * or via disabling bottom half handlers, etc). 281da177e4SLinus Torvalds * 291da177e4SLinus Torvalds * This program is free software; you can redistribute it and/or 301da177e4SLinus Torvalds * modify it under the terms of the GNU General Public License 311da177e4SLinus Torvalds * as published by the Free Software Foundation; either version 321da177e4SLinus Torvalds * 2 of the License, or (at your option) any later version. 331da177e4SLinus Torvalds */ 341da177e4SLinus Torvalds 351da177e4SLinus Torvalds /* 361da177e4SLinus Torvalds * The functions in this file will not compile correctly with gcc 2.4.x 371da177e4SLinus Torvalds */ 381da177e4SLinus Torvalds 39e005d193SJoe Perches #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 40e005d193SJoe Perches 411da177e4SLinus Torvalds #include <linux/module.h> 421da177e4SLinus Torvalds #include <linux/types.h> 431da177e4SLinus Torvalds #include <linux/kernel.h> 44fe55f6d5SVegard Nossum #include <linux/kmemcheck.h> 451da177e4SLinus Torvalds #include <linux/mm.h> 461da177e4SLinus Torvalds #include <linux/interrupt.h> 471da177e4SLinus Torvalds #include <linux/in.h> 481da177e4SLinus Torvalds #include <linux/inet.h> 491da177e4SLinus Torvalds #include <linux/slab.h> 501da177e4SLinus Torvalds #include <linux/netdevice.h> 511da177e4SLinus Torvalds #ifdef CONFIG_NET_CLS_ACT 521da177e4SLinus Torvalds #include <net/pkt_sched.h> 531da177e4SLinus Torvalds #endif 541da177e4SLinus Torvalds #include <linux/string.h> 551da177e4SLinus Torvalds #include <linux/skbuff.h> 569c55e01cSJens Axboe #include <linux/splice.h> 571da177e4SLinus Torvalds #include <linux/cache.h> 581da177e4SLinus Torvalds #include <linux/rtnetlink.h> 591da177e4SLinus Torvalds #include <linux/init.h> 60716ea3a7SDavid Howells #include <linux/scatterlist.h> 61ac45f602SPatrick Ohly #include <linux/errqueue.h> 62268bb0ceSLinus Torvalds #include <linux/prefetch.h> 631da177e4SLinus Torvalds 641da177e4SLinus Torvalds #include <net/protocol.h> 651da177e4SLinus Torvalds #include <net/dst.h> 661da177e4SLinus Torvalds #include <net/sock.h> 671da177e4SLinus Torvalds #include <net/checksum.h> 681da177e4SLinus Torvalds #include <net/xfrm.h> 691da177e4SLinus Torvalds 701da177e4SLinus Torvalds #include <asm/uaccess.h> 71ad8d75ffSSteven Rostedt #include <trace/events/skb.h> 7251c56b00SEric Dumazet #include <linux/highmem.h> 73a1f8e7f7SAl Viro 74d7e8883cSEric Dumazet struct kmem_cache *skbuff_head_cache __read_mostly; 75e18b890bSChristoph Lameter static struct kmem_cache *skbuff_fclone_cache __read_mostly; 761da177e4SLinus Torvalds 779c55e01cSJens Axboe static void sock_pipe_buf_release(struct pipe_inode_info *pipe, 789c55e01cSJens Axboe struct pipe_buffer *buf) 799c55e01cSJens Axboe { 808b9d3728SJarek Poplawski put_page(buf->page); 819c55e01cSJens Axboe } 829c55e01cSJens Axboe 839c55e01cSJens Axboe static void sock_pipe_buf_get(struct pipe_inode_info *pipe, 849c55e01cSJens Axboe struct pipe_buffer *buf) 859c55e01cSJens Axboe { 868b9d3728SJarek Poplawski get_page(buf->page); 879c55e01cSJens Axboe } 889c55e01cSJens Axboe 899c55e01cSJens Axboe static int sock_pipe_buf_steal(struct pipe_inode_info *pipe, 909c55e01cSJens Axboe struct pipe_buffer *buf) 919c55e01cSJens Axboe { 929c55e01cSJens Axboe return 1; 939c55e01cSJens Axboe } 949c55e01cSJens Axboe 959c55e01cSJens Axboe 969c55e01cSJens Axboe /* Pipe buffer operations for a socket. */ 9728dfef8fSAlexey Dobriyan static const struct pipe_buf_operations sock_pipe_buf_ops = { 989c55e01cSJens Axboe .can_merge = 0, 999c55e01cSJens Axboe .map = generic_pipe_buf_map, 1009c55e01cSJens Axboe .unmap = generic_pipe_buf_unmap, 1019c55e01cSJens Axboe .confirm = generic_pipe_buf_confirm, 1029c55e01cSJens Axboe .release = sock_pipe_buf_release, 1039c55e01cSJens Axboe .steal = sock_pipe_buf_steal, 1049c55e01cSJens Axboe .get = sock_pipe_buf_get, 1059c55e01cSJens Axboe }; 1069c55e01cSJens Axboe 1071da177e4SLinus Torvalds /* 1081da177e4SLinus Torvalds * Keep out-of-line to prevent kernel bloat. 1091da177e4SLinus Torvalds * __builtin_return_address is not used because it is not always 1101da177e4SLinus Torvalds * reliable. 1111da177e4SLinus Torvalds */ 1121da177e4SLinus Torvalds 1131da177e4SLinus Torvalds /** 1141da177e4SLinus Torvalds * skb_over_panic - private function 1151da177e4SLinus Torvalds * @skb: buffer 1161da177e4SLinus Torvalds * @sz: size 1171da177e4SLinus Torvalds * @here: address 1181da177e4SLinus Torvalds * 1191da177e4SLinus Torvalds * Out of line support code for skb_put(). Not user callable. 1201da177e4SLinus Torvalds */ 121ccb7c773SRami Rosen static void skb_over_panic(struct sk_buff *skb, int sz, void *here) 1221da177e4SLinus Torvalds { 123e005d193SJoe Perches pr_emerg("%s: text:%p len:%d put:%d head:%p data:%p tail:%#lx end:%#lx dev:%s\n", 124e005d193SJoe Perches __func__, here, skb->len, sz, skb->head, skb->data, 1254305b541SArnaldo Carvalho de Melo (unsigned long)skb->tail, (unsigned long)skb->end, 12626095455SPatrick McHardy skb->dev ? skb->dev->name : "<NULL>"); 1271da177e4SLinus Torvalds BUG(); 1281da177e4SLinus Torvalds } 1291da177e4SLinus Torvalds 1301da177e4SLinus Torvalds /** 1311da177e4SLinus Torvalds * skb_under_panic - private function 1321da177e4SLinus Torvalds * @skb: buffer 1331da177e4SLinus Torvalds * @sz: size 1341da177e4SLinus Torvalds * @here: address 1351da177e4SLinus Torvalds * 1361da177e4SLinus Torvalds * Out of line support code for skb_push(). Not user callable. 1371da177e4SLinus Torvalds */ 1381da177e4SLinus Torvalds 139ccb7c773SRami Rosen static void skb_under_panic(struct sk_buff *skb, int sz, void *here) 1401da177e4SLinus Torvalds { 141e005d193SJoe Perches pr_emerg("%s: text:%p len:%d put:%d head:%p data:%p tail:%#lx end:%#lx dev:%s\n", 142e005d193SJoe Perches __func__, here, skb->len, sz, skb->head, skb->data, 1434305b541SArnaldo Carvalho de Melo (unsigned long)skb->tail, (unsigned long)skb->end, 14426095455SPatrick McHardy skb->dev ? skb->dev->name : "<NULL>"); 1451da177e4SLinus Torvalds BUG(); 1461da177e4SLinus Torvalds } 1471da177e4SLinus Torvalds 148c93bdd0eSMel Gorman 149c93bdd0eSMel Gorman /* 150c93bdd0eSMel Gorman * kmalloc_reserve is a wrapper around kmalloc_node_track_caller that tells 151c93bdd0eSMel Gorman * the caller if emergency pfmemalloc reserves are being used. If it is and 152c93bdd0eSMel Gorman * the socket is later found to be SOCK_MEMALLOC then PFMEMALLOC reserves 153c93bdd0eSMel Gorman * may be used. Otherwise, the packet data may be discarded until enough 154c93bdd0eSMel Gorman * memory is free 155c93bdd0eSMel Gorman */ 156c93bdd0eSMel Gorman #define kmalloc_reserve(size, gfp, node, pfmemalloc) \ 157c93bdd0eSMel Gorman __kmalloc_reserve(size, gfp, node, _RET_IP_, pfmemalloc) 15861c5e88aSstephen hemminger 15961c5e88aSstephen hemminger static void *__kmalloc_reserve(size_t size, gfp_t flags, int node, 16061c5e88aSstephen hemminger unsigned long ip, bool *pfmemalloc) 161c93bdd0eSMel Gorman { 162c93bdd0eSMel Gorman void *obj; 163c93bdd0eSMel Gorman bool ret_pfmemalloc = false; 164c93bdd0eSMel Gorman 165c93bdd0eSMel Gorman /* 166c93bdd0eSMel Gorman * Try a regular allocation, when that fails and we're not entitled 167c93bdd0eSMel Gorman * to the reserves, fail. 168c93bdd0eSMel Gorman */ 169c93bdd0eSMel Gorman obj = kmalloc_node_track_caller(size, 170c93bdd0eSMel Gorman flags | __GFP_NOMEMALLOC | __GFP_NOWARN, 171c93bdd0eSMel Gorman node); 172c93bdd0eSMel Gorman if (obj || !(gfp_pfmemalloc_allowed(flags))) 173c93bdd0eSMel Gorman goto out; 174c93bdd0eSMel Gorman 175c93bdd0eSMel Gorman /* Try again but now we are using pfmemalloc reserves */ 176c93bdd0eSMel Gorman ret_pfmemalloc = true; 177c93bdd0eSMel Gorman obj = kmalloc_node_track_caller(size, flags, node); 178c93bdd0eSMel Gorman 179c93bdd0eSMel Gorman out: 180c93bdd0eSMel Gorman if (pfmemalloc) 181c93bdd0eSMel Gorman *pfmemalloc = ret_pfmemalloc; 182c93bdd0eSMel Gorman 183c93bdd0eSMel Gorman return obj; 184c93bdd0eSMel Gorman } 185c93bdd0eSMel Gorman 1861da177e4SLinus Torvalds /* Allocate a new skbuff. We do this ourselves so we can fill in a few 1871da177e4SLinus Torvalds * 'private' fields and also do memory statistics to find all the 1881da177e4SLinus Torvalds * [BEEP] leaks. 1891da177e4SLinus Torvalds * 1901da177e4SLinus Torvalds */ 1911da177e4SLinus Torvalds 1921da177e4SLinus Torvalds /** 193d179cd12SDavid S. Miller * __alloc_skb - allocate a network buffer 1941da177e4SLinus Torvalds * @size: size to allocate 1951da177e4SLinus Torvalds * @gfp_mask: allocation mask 196c93bdd0eSMel Gorman * @flags: If SKB_ALLOC_FCLONE is set, allocate from fclone cache 197c93bdd0eSMel Gorman * instead of head cache and allocate a cloned (child) skb. 198c93bdd0eSMel Gorman * If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for 199c93bdd0eSMel Gorman * allocations in case the data is required for writeback 200b30973f8SChristoph Hellwig * @node: numa node to allocate memory on 2011da177e4SLinus Torvalds * 2021da177e4SLinus Torvalds * Allocate a new &sk_buff. The returned buffer has no headroom and a 20394b6042cSBen Hutchings * tail room of at least size bytes. The object has a reference count 20494b6042cSBen Hutchings * of one. The return is the buffer. On a failure the return is %NULL. 2051da177e4SLinus Torvalds * 2061da177e4SLinus Torvalds * Buffers may only be allocated from interrupts using a @gfp_mask of 2071da177e4SLinus Torvalds * %GFP_ATOMIC. 2081da177e4SLinus Torvalds */ 209dd0fc66fSAl Viro struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, 210c93bdd0eSMel Gorman int flags, int node) 2111da177e4SLinus Torvalds { 212e18b890bSChristoph Lameter struct kmem_cache *cache; 2134947d3efSBenjamin LaHaise struct skb_shared_info *shinfo; 2141da177e4SLinus Torvalds struct sk_buff *skb; 2151da177e4SLinus Torvalds u8 *data; 216c93bdd0eSMel Gorman bool pfmemalloc; 2171da177e4SLinus Torvalds 218c93bdd0eSMel Gorman cache = (flags & SKB_ALLOC_FCLONE) 219c93bdd0eSMel Gorman ? skbuff_fclone_cache : skbuff_head_cache; 220c93bdd0eSMel Gorman 221c93bdd0eSMel Gorman if (sk_memalloc_socks() && (flags & SKB_ALLOC_RX)) 222c93bdd0eSMel Gorman gfp_mask |= __GFP_MEMALLOC; 2238798b3fbSHerbert Xu 2241da177e4SLinus Torvalds /* Get the HEAD */ 225b30973f8SChristoph Hellwig skb = kmem_cache_alloc_node(cache, gfp_mask & ~__GFP_DMA, node); 2261da177e4SLinus Torvalds if (!skb) 2271da177e4SLinus Torvalds goto out; 228ec7d2f2cSEric Dumazet prefetchw(skb); 2291da177e4SLinus Torvalds 23087fb4b7bSEric Dumazet /* We do our best to align skb_shared_info on a separate cache 23187fb4b7bSEric Dumazet * line. It usually works because kmalloc(X > SMP_CACHE_BYTES) gives 23287fb4b7bSEric Dumazet * aligned memory blocks, unless SLUB/SLAB debug is enabled. 23387fb4b7bSEric Dumazet * Both skb->head and skb_shared_info are cache line aligned. 23487fb4b7bSEric Dumazet */ 235bc417e30STony Lindgren size = SKB_DATA_ALIGN(size); 23687fb4b7bSEric Dumazet size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); 237c93bdd0eSMel Gorman data = kmalloc_reserve(size, gfp_mask, node, &pfmemalloc); 2381da177e4SLinus Torvalds if (!data) 2391da177e4SLinus Torvalds goto nodata; 24087fb4b7bSEric Dumazet /* kmalloc(size) might give us more room than requested. 24187fb4b7bSEric Dumazet * Put skb_shared_info exactly at the end of allocated zone, 24287fb4b7bSEric Dumazet * to allow max possible filling before reallocation. 24387fb4b7bSEric Dumazet */ 24487fb4b7bSEric Dumazet size = SKB_WITH_OVERHEAD(ksize(data)); 245ec7d2f2cSEric Dumazet prefetchw(data + size); 2461da177e4SLinus Torvalds 247ca0605a7SArnaldo Carvalho de Melo /* 248c8005785SJohannes Berg * Only clear those fields we need to clear, not those that we will 249c8005785SJohannes Berg * actually initialise below. Hence, don't put any more fields after 250c8005785SJohannes Berg * the tail pointer in struct sk_buff! 251ca0605a7SArnaldo Carvalho de Melo */ 252ca0605a7SArnaldo Carvalho de Melo memset(skb, 0, offsetof(struct sk_buff, tail)); 25387fb4b7bSEric Dumazet /* Account for allocated memory : skb + skb->head */ 25487fb4b7bSEric Dumazet skb->truesize = SKB_TRUESIZE(size); 255c93bdd0eSMel Gorman skb->pfmemalloc = pfmemalloc; 2561da177e4SLinus Torvalds atomic_set(&skb->users, 1); 2571da177e4SLinus Torvalds skb->head = data; 2581da177e4SLinus Torvalds skb->data = data; 25927a884dcSArnaldo Carvalho de Melo skb_reset_tail_pointer(skb); 2604305b541SArnaldo Carvalho de Melo skb->end = skb->tail + size; 26119633e12SStephen Hemminger #ifdef NET_SKBUFF_DATA_USES_OFFSET 26219633e12SStephen Hemminger skb->mac_header = ~0U; 263fda55ecaSEric Dumazet skb->transport_header = ~0U; 26419633e12SStephen Hemminger #endif 26519633e12SStephen Hemminger 2664947d3efSBenjamin LaHaise /* make sure we initialize shinfo sequentially */ 2674947d3efSBenjamin LaHaise shinfo = skb_shinfo(skb); 268ec7d2f2cSEric Dumazet memset(shinfo, 0, offsetof(struct skb_shared_info, dataref)); 2694947d3efSBenjamin LaHaise atomic_set(&shinfo->dataref, 1); 270c2aa3665SEric Dumazet kmemcheck_annotate_variable(shinfo->destructor_arg); 2714947d3efSBenjamin LaHaise 272c93bdd0eSMel Gorman if (flags & SKB_ALLOC_FCLONE) { 273d179cd12SDavid S. Miller struct sk_buff *child = skb + 1; 274d179cd12SDavid S. Miller atomic_t *fclone_ref = (atomic_t *) (child + 1); 2751da177e4SLinus Torvalds 276fe55f6d5SVegard Nossum kmemcheck_annotate_bitfield(child, flags1); 277fe55f6d5SVegard Nossum kmemcheck_annotate_bitfield(child, flags2); 278d179cd12SDavid S. Miller skb->fclone = SKB_FCLONE_ORIG; 279d179cd12SDavid S. Miller atomic_set(fclone_ref, 1); 280d179cd12SDavid S. Miller 281d179cd12SDavid S. Miller child->fclone = SKB_FCLONE_UNAVAILABLE; 282c93bdd0eSMel Gorman child->pfmemalloc = pfmemalloc; 283d179cd12SDavid S. Miller } 2841da177e4SLinus Torvalds out: 2851da177e4SLinus Torvalds return skb; 2861da177e4SLinus Torvalds nodata: 2878798b3fbSHerbert Xu kmem_cache_free(cache, skb); 2881da177e4SLinus Torvalds skb = NULL; 2891da177e4SLinus Torvalds goto out; 2901da177e4SLinus Torvalds } 291b4ac530fSDavid S. Miller EXPORT_SYMBOL(__alloc_skb); 2921da177e4SLinus Torvalds 2931da177e4SLinus Torvalds /** 294b2b5ce9dSEric Dumazet * build_skb - build a network buffer 295b2b5ce9dSEric Dumazet * @data: data buffer provided by caller 296d3836f21SEric Dumazet * @frag_size: size of fragment, or 0 if head was kmalloced 297b2b5ce9dSEric Dumazet * 298b2b5ce9dSEric Dumazet * Allocate a new &sk_buff. Caller provides space holding head and 299b2b5ce9dSEric Dumazet * skb_shared_info. @data must have been allocated by kmalloc() 300b2b5ce9dSEric Dumazet * The return is the new skb buffer. 301b2b5ce9dSEric Dumazet * On a failure the return is %NULL, and @data is not freed. 302b2b5ce9dSEric Dumazet * Notes : 303b2b5ce9dSEric Dumazet * Before IO, driver allocates only data buffer where NIC put incoming frame 304b2b5ce9dSEric Dumazet * Driver should add room at head (NET_SKB_PAD) and 305b2b5ce9dSEric Dumazet * MUST add room at tail (SKB_DATA_ALIGN(skb_shared_info)) 306b2b5ce9dSEric Dumazet * After IO, driver calls build_skb(), to allocate sk_buff and populate it 307b2b5ce9dSEric Dumazet * before giving packet to stack. 308b2b5ce9dSEric Dumazet * RX rings only contains data buffers, not full skbs. 309b2b5ce9dSEric Dumazet */ 310d3836f21SEric Dumazet struct sk_buff *build_skb(void *data, unsigned int frag_size) 311b2b5ce9dSEric Dumazet { 312b2b5ce9dSEric Dumazet struct skb_shared_info *shinfo; 313b2b5ce9dSEric Dumazet struct sk_buff *skb; 314d3836f21SEric Dumazet unsigned int size = frag_size ? : ksize(data); 315b2b5ce9dSEric Dumazet 316b2b5ce9dSEric Dumazet skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC); 317b2b5ce9dSEric Dumazet if (!skb) 318b2b5ce9dSEric Dumazet return NULL; 319b2b5ce9dSEric Dumazet 320d3836f21SEric Dumazet size -= SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); 321b2b5ce9dSEric Dumazet 322b2b5ce9dSEric Dumazet memset(skb, 0, offsetof(struct sk_buff, tail)); 323b2b5ce9dSEric Dumazet skb->truesize = SKB_TRUESIZE(size); 324d3836f21SEric Dumazet skb->head_frag = frag_size != 0; 325b2b5ce9dSEric Dumazet atomic_set(&skb->users, 1); 326b2b5ce9dSEric Dumazet skb->head = data; 327b2b5ce9dSEric Dumazet skb->data = data; 328b2b5ce9dSEric Dumazet skb_reset_tail_pointer(skb); 329b2b5ce9dSEric Dumazet skb->end = skb->tail + size; 330b2b5ce9dSEric Dumazet #ifdef NET_SKBUFF_DATA_USES_OFFSET 331b2b5ce9dSEric Dumazet skb->mac_header = ~0U; 332fda55ecaSEric Dumazet skb->transport_header = ~0U; 333b2b5ce9dSEric Dumazet #endif 334b2b5ce9dSEric Dumazet 335b2b5ce9dSEric Dumazet /* make sure we initialize shinfo sequentially */ 336b2b5ce9dSEric Dumazet shinfo = skb_shinfo(skb); 337b2b5ce9dSEric Dumazet memset(shinfo, 0, offsetof(struct skb_shared_info, dataref)); 338b2b5ce9dSEric Dumazet atomic_set(&shinfo->dataref, 1); 339b2b5ce9dSEric Dumazet kmemcheck_annotate_variable(shinfo->destructor_arg); 340b2b5ce9dSEric Dumazet 341b2b5ce9dSEric Dumazet return skb; 342b2b5ce9dSEric Dumazet } 343b2b5ce9dSEric Dumazet EXPORT_SYMBOL(build_skb); 344b2b5ce9dSEric Dumazet 345a1c7fff7SEric Dumazet struct netdev_alloc_cache { 34669b08f62SEric Dumazet struct page_frag frag; 34769b08f62SEric Dumazet /* we maintain a pagecount bias, so that we dont dirty cache line 34869b08f62SEric Dumazet * containing page->_count every time we allocate a fragment. 34969b08f62SEric Dumazet */ 350540eb7bfSAlexander Duyck unsigned int pagecnt_bias; 351a1c7fff7SEric Dumazet }; 352a1c7fff7SEric Dumazet static DEFINE_PER_CPU(struct netdev_alloc_cache, netdev_alloc_cache); 353a1c7fff7SEric Dumazet 35469b08f62SEric Dumazet #define NETDEV_FRAG_PAGE_MAX_ORDER get_order(32768) 35569b08f62SEric Dumazet #define NETDEV_FRAG_PAGE_MAX_SIZE (PAGE_SIZE << NETDEV_FRAG_PAGE_MAX_ORDER) 35669b08f62SEric Dumazet #define NETDEV_PAGECNT_MAX_BIAS NETDEV_FRAG_PAGE_MAX_SIZE 357540eb7bfSAlexander Duyck 358c93bdd0eSMel Gorman static void *__netdev_alloc_frag(unsigned int fragsz, gfp_t gfp_mask) 3596f532612SEric Dumazet { 3606f532612SEric Dumazet struct netdev_alloc_cache *nc; 3616f532612SEric Dumazet void *data = NULL; 36269b08f62SEric Dumazet int order; 3636f532612SEric Dumazet unsigned long flags; 3646f532612SEric Dumazet 3656f532612SEric Dumazet local_irq_save(flags); 3666f532612SEric Dumazet nc = &__get_cpu_var(netdev_alloc_cache); 36769b08f62SEric Dumazet if (unlikely(!nc->frag.page)) { 3686f532612SEric Dumazet refill: 36969b08f62SEric Dumazet for (order = NETDEV_FRAG_PAGE_MAX_ORDER; ;) { 37069b08f62SEric Dumazet gfp_t gfp = gfp_mask; 37169b08f62SEric Dumazet 37269b08f62SEric Dumazet if (order) 37369b08f62SEric Dumazet gfp |= __GFP_COMP | __GFP_NOWARN; 37469b08f62SEric Dumazet nc->frag.page = alloc_pages(gfp, order); 37569b08f62SEric Dumazet if (likely(nc->frag.page)) 37669b08f62SEric Dumazet break; 37769b08f62SEric Dumazet if (--order < 0) 378540eb7bfSAlexander Duyck goto end; 37969b08f62SEric Dumazet } 38069b08f62SEric Dumazet nc->frag.size = PAGE_SIZE << order; 381540eb7bfSAlexander Duyck recycle: 38269b08f62SEric Dumazet atomic_set(&nc->frag.page->_count, NETDEV_PAGECNT_MAX_BIAS); 38369b08f62SEric Dumazet nc->pagecnt_bias = NETDEV_PAGECNT_MAX_BIAS; 38469b08f62SEric Dumazet nc->frag.offset = 0; 3856f532612SEric Dumazet } 386540eb7bfSAlexander Duyck 38769b08f62SEric Dumazet if (nc->frag.offset + fragsz > nc->frag.size) { 388540eb7bfSAlexander Duyck /* avoid unnecessary locked operations if possible */ 38969b08f62SEric Dumazet if ((atomic_read(&nc->frag.page->_count) == nc->pagecnt_bias) || 39069b08f62SEric Dumazet atomic_sub_and_test(nc->pagecnt_bias, &nc->frag.page->_count)) 391540eb7bfSAlexander Duyck goto recycle; 3926f532612SEric Dumazet goto refill; 3936f532612SEric Dumazet } 394540eb7bfSAlexander Duyck 39569b08f62SEric Dumazet data = page_address(nc->frag.page) + nc->frag.offset; 39669b08f62SEric Dumazet nc->frag.offset += fragsz; 397540eb7bfSAlexander Duyck nc->pagecnt_bias--; 398540eb7bfSAlexander Duyck end: 3996f532612SEric Dumazet local_irq_restore(flags); 4006f532612SEric Dumazet return data; 4016f532612SEric Dumazet } 402c93bdd0eSMel Gorman 403c93bdd0eSMel Gorman /** 404c93bdd0eSMel Gorman * netdev_alloc_frag - allocate a page fragment 405c93bdd0eSMel Gorman * @fragsz: fragment size 406c93bdd0eSMel Gorman * 407c93bdd0eSMel Gorman * Allocates a frag from a page for receive buffer. 408c93bdd0eSMel Gorman * Uses GFP_ATOMIC allocations. 409c93bdd0eSMel Gorman */ 410c93bdd0eSMel Gorman void *netdev_alloc_frag(unsigned int fragsz) 411c93bdd0eSMel Gorman { 412c93bdd0eSMel Gorman return __netdev_alloc_frag(fragsz, GFP_ATOMIC | __GFP_COLD); 413c93bdd0eSMel Gorman } 4146f532612SEric Dumazet EXPORT_SYMBOL(netdev_alloc_frag); 4156f532612SEric Dumazet 4166f532612SEric Dumazet /** 4178af27456SChristoph Hellwig * __netdev_alloc_skb - allocate an skbuff for rx on a specific device 4188af27456SChristoph Hellwig * @dev: network device to receive on 4198af27456SChristoph Hellwig * @length: length to allocate 4208af27456SChristoph Hellwig * @gfp_mask: get_free_pages mask, passed to alloc_skb 4218af27456SChristoph Hellwig * 4228af27456SChristoph Hellwig * Allocate a new &sk_buff and assign it a usage count of one. The 4238af27456SChristoph Hellwig * buffer has unspecified headroom built in. Users should allocate 4248af27456SChristoph Hellwig * the headroom they think they need without accounting for the 4258af27456SChristoph Hellwig * built in space. The built in space is used for optimisations. 4268af27456SChristoph Hellwig * 4278af27456SChristoph Hellwig * %NULL is returned if there is no free memory. 4288af27456SChristoph Hellwig */ 4298af27456SChristoph Hellwig struct sk_buff *__netdev_alloc_skb(struct net_device *dev, 4308af27456SChristoph Hellwig unsigned int length, gfp_t gfp_mask) 4318af27456SChristoph Hellwig { 4326f532612SEric Dumazet struct sk_buff *skb = NULL; 433a1c7fff7SEric Dumazet unsigned int fragsz = SKB_DATA_ALIGN(length + NET_SKB_PAD) + 434a1c7fff7SEric Dumazet SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); 4358af27456SChristoph Hellwig 436310e158cSEric Dumazet if (fragsz <= PAGE_SIZE && !(gfp_mask & (__GFP_WAIT | GFP_DMA))) { 437c93bdd0eSMel Gorman void *data; 438c93bdd0eSMel Gorman 439c93bdd0eSMel Gorman if (sk_memalloc_socks()) 440c93bdd0eSMel Gorman gfp_mask |= __GFP_MEMALLOC; 441c93bdd0eSMel Gorman 442c93bdd0eSMel Gorman data = __netdev_alloc_frag(fragsz, gfp_mask); 443a1c7fff7SEric Dumazet 4446f532612SEric Dumazet if (likely(data)) { 4456f532612SEric Dumazet skb = build_skb(data, fragsz); 4466f532612SEric Dumazet if (unlikely(!skb)) 4476f532612SEric Dumazet put_page(virt_to_head_page(data)); 448a1c7fff7SEric Dumazet } 449a1c7fff7SEric Dumazet } else { 450c93bdd0eSMel Gorman skb = __alloc_skb(length + NET_SKB_PAD, gfp_mask, 451c93bdd0eSMel Gorman SKB_ALLOC_RX, NUMA_NO_NODE); 452a1c7fff7SEric Dumazet } 4537b2e497aSChristoph Hellwig if (likely(skb)) { 4548af27456SChristoph Hellwig skb_reserve(skb, NET_SKB_PAD); 4557b2e497aSChristoph Hellwig skb->dev = dev; 4567b2e497aSChristoph Hellwig } 4578af27456SChristoph Hellwig return skb; 4588af27456SChristoph Hellwig } 459b4ac530fSDavid S. Miller EXPORT_SYMBOL(__netdev_alloc_skb); 4601da177e4SLinus Torvalds 461654bed16SPeter Zijlstra void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, int off, 46250269e19SEric Dumazet int size, unsigned int truesize) 463654bed16SPeter Zijlstra { 464654bed16SPeter Zijlstra skb_fill_page_desc(skb, i, page, off, size); 465654bed16SPeter Zijlstra skb->len += size; 466654bed16SPeter Zijlstra skb->data_len += size; 46750269e19SEric Dumazet skb->truesize += truesize; 468654bed16SPeter Zijlstra } 469654bed16SPeter Zijlstra EXPORT_SYMBOL(skb_add_rx_frag); 470654bed16SPeter Zijlstra 47127b437c8SHerbert Xu static void skb_drop_list(struct sk_buff **listp) 4721da177e4SLinus Torvalds { 47327b437c8SHerbert Xu struct sk_buff *list = *listp; 4741da177e4SLinus Torvalds 47527b437c8SHerbert Xu *listp = NULL; 4761da177e4SLinus Torvalds 4771da177e4SLinus Torvalds do { 4781da177e4SLinus Torvalds struct sk_buff *this = list; 4791da177e4SLinus Torvalds list = list->next; 4801da177e4SLinus Torvalds kfree_skb(this); 4811da177e4SLinus Torvalds } while (list); 4821da177e4SLinus Torvalds } 4831da177e4SLinus Torvalds 48427b437c8SHerbert Xu static inline void skb_drop_fraglist(struct sk_buff *skb) 48527b437c8SHerbert Xu { 48627b437c8SHerbert Xu skb_drop_list(&skb_shinfo(skb)->frag_list); 48727b437c8SHerbert Xu } 48827b437c8SHerbert Xu 4891da177e4SLinus Torvalds static void skb_clone_fraglist(struct sk_buff *skb) 4901da177e4SLinus Torvalds { 4911da177e4SLinus Torvalds struct sk_buff *list; 4921da177e4SLinus Torvalds 493fbb398a8SDavid S. Miller skb_walk_frags(skb, list) 4941da177e4SLinus Torvalds skb_get(list); 4951da177e4SLinus Torvalds } 4961da177e4SLinus Torvalds 497d3836f21SEric Dumazet static void skb_free_head(struct sk_buff *skb) 498d3836f21SEric Dumazet { 499d3836f21SEric Dumazet if (skb->head_frag) 500d3836f21SEric Dumazet put_page(virt_to_head_page(skb->head)); 501d3836f21SEric Dumazet else 502d3836f21SEric Dumazet kfree(skb->head); 503d3836f21SEric Dumazet } 504d3836f21SEric Dumazet 5055bba1712SAdrian Bunk static void skb_release_data(struct sk_buff *skb) 5061da177e4SLinus Torvalds { 5071da177e4SLinus Torvalds if (!skb->cloned || 5081da177e4SLinus Torvalds !atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1, 5091da177e4SLinus Torvalds &skb_shinfo(skb)->dataref)) { 5101da177e4SLinus Torvalds if (skb_shinfo(skb)->nr_frags) { 5111da177e4SLinus Torvalds int i; 5121da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) 513ea2ab693SIan Campbell skb_frag_unref(skb, i); 5141da177e4SLinus Torvalds } 5151da177e4SLinus Torvalds 516a6686f2fSShirley Ma /* 517a6686f2fSShirley Ma * If skb buf is from userspace, we need to notify the caller 518a6686f2fSShirley Ma * the lower device DMA has done; 519a6686f2fSShirley Ma */ 520a6686f2fSShirley Ma if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) { 521a6686f2fSShirley Ma struct ubuf_info *uarg; 522a6686f2fSShirley Ma 523a6686f2fSShirley Ma uarg = skb_shinfo(skb)->destructor_arg; 524a6686f2fSShirley Ma if (uarg->callback) 525e19d6763SMichael S. Tsirkin uarg->callback(uarg, true); 526a6686f2fSShirley Ma } 527a6686f2fSShirley Ma 52821dc3301SDavid S. Miller if (skb_has_frag_list(skb)) 5291da177e4SLinus Torvalds skb_drop_fraglist(skb); 5301da177e4SLinus Torvalds 531d3836f21SEric Dumazet skb_free_head(skb); 5321da177e4SLinus Torvalds } 5331da177e4SLinus Torvalds } 5341da177e4SLinus Torvalds 5351da177e4SLinus Torvalds /* 5361da177e4SLinus Torvalds * Free an skbuff by memory without cleaning the state. 5371da177e4SLinus Torvalds */ 5382d4baff8SHerbert Xu static void kfree_skbmem(struct sk_buff *skb) 5391da177e4SLinus Torvalds { 540d179cd12SDavid S. Miller struct sk_buff *other; 541d179cd12SDavid S. Miller atomic_t *fclone_ref; 542d179cd12SDavid S. Miller 543d179cd12SDavid S. Miller switch (skb->fclone) { 544d179cd12SDavid S. Miller case SKB_FCLONE_UNAVAILABLE: 5451da177e4SLinus Torvalds kmem_cache_free(skbuff_head_cache, skb); 546d179cd12SDavid S. Miller break; 547d179cd12SDavid S. Miller 548d179cd12SDavid S. Miller case SKB_FCLONE_ORIG: 549d179cd12SDavid S. Miller fclone_ref = (atomic_t *) (skb + 2); 550d179cd12SDavid S. Miller if (atomic_dec_and_test(fclone_ref)) 551d179cd12SDavid S. Miller kmem_cache_free(skbuff_fclone_cache, skb); 552d179cd12SDavid S. Miller break; 553d179cd12SDavid S. Miller 554d179cd12SDavid S. Miller case SKB_FCLONE_CLONE: 555d179cd12SDavid S. Miller fclone_ref = (atomic_t *) (skb + 1); 556d179cd12SDavid S. Miller other = skb - 1; 557d179cd12SDavid S. Miller 558d179cd12SDavid S. Miller /* The clone portion is available for 559d179cd12SDavid S. Miller * fast-cloning again. 560d179cd12SDavid S. Miller */ 561d179cd12SDavid S. Miller skb->fclone = SKB_FCLONE_UNAVAILABLE; 562d179cd12SDavid S. Miller 563d179cd12SDavid S. Miller if (atomic_dec_and_test(fclone_ref)) 564d179cd12SDavid S. Miller kmem_cache_free(skbuff_fclone_cache, other); 565d179cd12SDavid S. Miller break; 5663ff50b79SStephen Hemminger } 5671da177e4SLinus Torvalds } 5681da177e4SLinus Torvalds 56904a4bb55SLennert Buytenhek static void skb_release_head_state(struct sk_buff *skb) 5701da177e4SLinus Torvalds { 571adf30907SEric Dumazet skb_dst_drop(skb); 5721da177e4SLinus Torvalds #ifdef CONFIG_XFRM 5731da177e4SLinus Torvalds secpath_put(skb->sp); 5741da177e4SLinus Torvalds #endif 5751da177e4SLinus Torvalds if (skb->destructor) { 5769c2b3328SStephen Hemminger WARN_ON(in_irq()); 5771da177e4SLinus Torvalds skb->destructor(skb); 5781da177e4SLinus Torvalds } 579a3bf7ae9SIgor Maravić #if IS_ENABLED(CONFIG_NF_CONNTRACK) 5805f79e0f9SYasuyuki Kozakai nf_conntrack_put(skb->nfct); 5812fc72c7bSKOVACS Krisztian #endif 5822fc72c7bSKOVACS Krisztian #ifdef NET_SKBUFF_NF_DEFRAG_NEEDED 5839fb9cbb1SYasuyuki Kozakai nf_conntrack_put_reasm(skb->nfct_reasm); 5849fb9cbb1SYasuyuki Kozakai #endif 5851da177e4SLinus Torvalds #ifdef CONFIG_BRIDGE_NETFILTER 5861da177e4SLinus Torvalds nf_bridge_put(skb->nf_bridge); 5871da177e4SLinus Torvalds #endif 5881da177e4SLinus Torvalds /* XXX: IS this still necessary? - JHS */ 5891da177e4SLinus Torvalds #ifdef CONFIG_NET_SCHED 5901da177e4SLinus Torvalds skb->tc_index = 0; 5911da177e4SLinus Torvalds #ifdef CONFIG_NET_CLS_ACT 5921da177e4SLinus Torvalds skb->tc_verd = 0; 5931da177e4SLinus Torvalds #endif 5941da177e4SLinus Torvalds #endif 59504a4bb55SLennert Buytenhek } 59604a4bb55SLennert Buytenhek 59704a4bb55SLennert Buytenhek /* Free everything but the sk_buff shell. */ 59804a4bb55SLennert Buytenhek static void skb_release_all(struct sk_buff *skb) 59904a4bb55SLennert Buytenhek { 60004a4bb55SLennert Buytenhek skb_release_head_state(skb); 6012d4baff8SHerbert Xu skb_release_data(skb); 6022d4baff8SHerbert Xu } 6031da177e4SLinus Torvalds 6042d4baff8SHerbert Xu /** 6052d4baff8SHerbert Xu * __kfree_skb - private function 6062d4baff8SHerbert Xu * @skb: buffer 6072d4baff8SHerbert Xu * 6082d4baff8SHerbert Xu * Free an sk_buff. Release anything attached to the buffer. 6092d4baff8SHerbert Xu * Clean the state. This is an internal helper function. Users should 6102d4baff8SHerbert Xu * always call kfree_skb 6112d4baff8SHerbert Xu */ 6122d4baff8SHerbert Xu 6132d4baff8SHerbert Xu void __kfree_skb(struct sk_buff *skb) 6142d4baff8SHerbert Xu { 6152d4baff8SHerbert Xu skb_release_all(skb); 6161da177e4SLinus Torvalds kfree_skbmem(skb); 6171da177e4SLinus Torvalds } 618b4ac530fSDavid S. Miller EXPORT_SYMBOL(__kfree_skb); 6191da177e4SLinus Torvalds 6201da177e4SLinus Torvalds /** 621231d06aeSJörn Engel * kfree_skb - free an sk_buff 622231d06aeSJörn Engel * @skb: buffer to free 623231d06aeSJörn Engel * 624231d06aeSJörn Engel * Drop a reference to the buffer and free it if the usage count has 625231d06aeSJörn Engel * hit zero. 626231d06aeSJörn Engel */ 627231d06aeSJörn Engel void kfree_skb(struct sk_buff *skb) 628231d06aeSJörn Engel { 629231d06aeSJörn Engel if (unlikely(!skb)) 630231d06aeSJörn Engel return; 631231d06aeSJörn Engel if (likely(atomic_read(&skb->users) == 1)) 632231d06aeSJörn Engel smp_rmb(); 633231d06aeSJörn Engel else if (likely(!atomic_dec_and_test(&skb->users))) 634231d06aeSJörn Engel return; 635ead2ceb0SNeil Horman trace_kfree_skb(skb, __builtin_return_address(0)); 636231d06aeSJörn Engel __kfree_skb(skb); 637231d06aeSJörn Engel } 638b4ac530fSDavid S. Miller EXPORT_SYMBOL(kfree_skb); 639231d06aeSJörn Engel 640d1a203eaSStephen Hemminger /** 64125121173SMichael S. Tsirkin * skb_tx_error - report an sk_buff xmit error 64225121173SMichael S. Tsirkin * @skb: buffer that triggered an error 64325121173SMichael S. Tsirkin * 64425121173SMichael S. Tsirkin * Report xmit error if a device callback is tracking this skb. 64525121173SMichael S. Tsirkin * skb must be freed afterwards. 64625121173SMichael S. Tsirkin */ 64725121173SMichael S. Tsirkin void skb_tx_error(struct sk_buff *skb) 64825121173SMichael S. Tsirkin { 64925121173SMichael S. Tsirkin if (skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY) { 65025121173SMichael S. Tsirkin struct ubuf_info *uarg; 65125121173SMichael S. Tsirkin 65225121173SMichael S. Tsirkin uarg = skb_shinfo(skb)->destructor_arg; 65325121173SMichael S. Tsirkin if (uarg->callback) 65425121173SMichael S. Tsirkin uarg->callback(uarg, false); 65525121173SMichael S. Tsirkin skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY; 65625121173SMichael S. Tsirkin } 65725121173SMichael S. Tsirkin } 65825121173SMichael S. Tsirkin EXPORT_SYMBOL(skb_tx_error); 65925121173SMichael S. Tsirkin 66025121173SMichael S. Tsirkin /** 661ead2ceb0SNeil Horman * consume_skb - free an skbuff 662ead2ceb0SNeil Horman * @skb: buffer to free 663ead2ceb0SNeil Horman * 664ead2ceb0SNeil Horman * Drop a ref to the buffer and free it if the usage count has hit zero 665ead2ceb0SNeil Horman * Functions identically to kfree_skb, but kfree_skb assumes that the frame 666ead2ceb0SNeil Horman * is being dropped after a failure and notes that 667ead2ceb0SNeil Horman */ 668ead2ceb0SNeil Horman void consume_skb(struct sk_buff *skb) 669ead2ceb0SNeil Horman { 670ead2ceb0SNeil Horman if (unlikely(!skb)) 671ead2ceb0SNeil Horman return; 672ead2ceb0SNeil Horman if (likely(atomic_read(&skb->users) == 1)) 673ead2ceb0SNeil Horman smp_rmb(); 674ead2ceb0SNeil Horman else if (likely(!atomic_dec_and_test(&skb->users))) 675ead2ceb0SNeil Horman return; 67607dc22e7SKoki Sanagi trace_consume_skb(skb); 677ead2ceb0SNeil Horman __kfree_skb(skb); 678ead2ceb0SNeil Horman } 679ead2ceb0SNeil Horman EXPORT_SYMBOL(consume_skb); 680ead2ceb0SNeil Horman 681dec18810SHerbert Xu static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) 682dec18810SHerbert Xu { 683dec18810SHerbert Xu new->tstamp = old->tstamp; 684dec18810SHerbert Xu new->dev = old->dev; 685dec18810SHerbert Xu new->transport_header = old->transport_header; 686dec18810SHerbert Xu new->network_header = old->network_header; 687dec18810SHerbert Xu new->mac_header = old->mac_header; 6886a674e9cSJoseph Gasparakis new->inner_transport_header = old->inner_transport_header; 6896a674e9cSJoseph Gasparakis new->inner_network_header = old->inner_transport_header; 6907fee226aSEric Dumazet skb_dst_copy(new, old); 6910a9627f2STom Herbert new->rxhash = old->rxhash; 6926461be3aSChangli Gao new->ooo_okay = old->ooo_okay; 693bdeab991STom Herbert new->l4_rxhash = old->l4_rxhash; 6943bdc0ebaSBen Greear new->no_fcs = old->no_fcs; 6956a674e9cSJoseph Gasparakis new->encapsulation = old->encapsulation; 696def8b4faSAlexey Dobriyan #ifdef CONFIG_XFRM 697dec18810SHerbert Xu new->sp = secpath_get(old->sp); 698dec18810SHerbert Xu #endif 699dec18810SHerbert Xu memcpy(new->cb, old->cb, sizeof(old->cb)); 7009bcb97caSHerbert Xu new->csum = old->csum; 701dec18810SHerbert Xu new->local_df = old->local_df; 702dec18810SHerbert Xu new->pkt_type = old->pkt_type; 703dec18810SHerbert Xu new->ip_summed = old->ip_summed; 704dec18810SHerbert Xu skb_copy_queue_mapping(new, old); 705dec18810SHerbert Xu new->priority = old->priority; 706a3bf7ae9SIgor Maravić #if IS_ENABLED(CONFIG_IP_VS) 707dec18810SHerbert Xu new->ipvs_property = old->ipvs_property; 708dec18810SHerbert Xu #endif 709c93bdd0eSMel Gorman new->pfmemalloc = old->pfmemalloc; 710dec18810SHerbert Xu new->protocol = old->protocol; 711dec18810SHerbert Xu new->mark = old->mark; 7128964be4aSEric Dumazet new->skb_iif = old->skb_iif; 713dec18810SHerbert Xu __nf_copy(new, old); 714a3bf7ae9SIgor Maravić #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 715dec18810SHerbert Xu new->nf_trace = old->nf_trace; 716dec18810SHerbert Xu #endif 717dec18810SHerbert Xu #ifdef CONFIG_NET_SCHED 718dec18810SHerbert Xu new->tc_index = old->tc_index; 719dec18810SHerbert Xu #ifdef CONFIG_NET_CLS_ACT 720dec18810SHerbert Xu new->tc_verd = old->tc_verd; 721dec18810SHerbert Xu #endif 722dec18810SHerbert Xu #endif 7236aa895b0SPatrick McHardy new->vlan_tci = old->vlan_tci; 7246aa895b0SPatrick McHardy 725dec18810SHerbert Xu skb_copy_secmark(new, old); 726dec18810SHerbert Xu } 727dec18810SHerbert Xu 72882c49a35SHerbert Xu /* 72982c49a35SHerbert Xu * You should not add any new code to this function. Add it to 73082c49a35SHerbert Xu * __copy_skb_header above instead. 73182c49a35SHerbert Xu */ 732e0053ec0SHerbert Xu static struct sk_buff *__skb_clone(struct sk_buff *n, struct sk_buff *skb) 7331da177e4SLinus Torvalds { 7341da177e4SLinus Torvalds #define C(x) n->x = skb->x 7351da177e4SLinus Torvalds 7361da177e4SLinus Torvalds n->next = n->prev = NULL; 7371da177e4SLinus Torvalds n->sk = NULL; 738dec18810SHerbert Xu __copy_skb_header(n, skb); 739dec18810SHerbert Xu 7401da177e4SLinus Torvalds C(len); 7411da177e4SLinus Torvalds C(data_len); 7423e6b3b2eSAlexey Dobriyan C(mac_len); 743334a8132SPatrick McHardy n->hdr_len = skb->nohdr ? skb_headroom(skb) : skb->hdr_len; 74402f1c89dSPaul Moore n->cloned = 1; 7451da177e4SLinus Torvalds n->nohdr = 0; 7461da177e4SLinus Torvalds n->destructor = NULL; 7471da177e4SLinus Torvalds C(tail); 7481da177e4SLinus Torvalds C(end); 74902f1c89dSPaul Moore C(head); 750d3836f21SEric Dumazet C(head_frag); 75102f1c89dSPaul Moore C(data); 75202f1c89dSPaul Moore C(truesize); 75302f1c89dSPaul Moore atomic_set(&n->users, 1); 7541da177e4SLinus Torvalds 7551da177e4SLinus Torvalds atomic_inc(&(skb_shinfo(skb)->dataref)); 7561da177e4SLinus Torvalds skb->cloned = 1; 7571da177e4SLinus Torvalds 7581da177e4SLinus Torvalds return n; 759e0053ec0SHerbert Xu #undef C 760e0053ec0SHerbert Xu } 761e0053ec0SHerbert Xu 762e0053ec0SHerbert Xu /** 763e0053ec0SHerbert Xu * skb_morph - morph one skb into another 764e0053ec0SHerbert Xu * @dst: the skb to receive the contents 765e0053ec0SHerbert Xu * @src: the skb to supply the contents 766e0053ec0SHerbert Xu * 767e0053ec0SHerbert Xu * This is identical to skb_clone except that the target skb is 768e0053ec0SHerbert Xu * supplied by the user. 769e0053ec0SHerbert Xu * 770e0053ec0SHerbert Xu * The target skb is returned upon exit. 771e0053ec0SHerbert Xu */ 772e0053ec0SHerbert Xu struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src) 773e0053ec0SHerbert Xu { 7742d4baff8SHerbert Xu skb_release_all(dst); 775e0053ec0SHerbert Xu return __skb_clone(dst, src); 776e0053ec0SHerbert Xu } 777e0053ec0SHerbert Xu EXPORT_SYMBOL_GPL(skb_morph); 778e0053ec0SHerbert Xu 7792c53040fSBen Hutchings /** 7802c53040fSBen Hutchings * skb_copy_ubufs - copy userspace skb frags buffers to kernel 78148c83012SMichael S. Tsirkin * @skb: the skb to modify 78248c83012SMichael S. Tsirkin * @gfp_mask: allocation priority 78348c83012SMichael S. Tsirkin * 78448c83012SMichael S. Tsirkin * This must be called on SKBTX_DEV_ZEROCOPY skb. 78548c83012SMichael S. Tsirkin * It will copy all frags into kernel and drop the reference 78648c83012SMichael S. Tsirkin * to userspace pages. 78748c83012SMichael S. Tsirkin * 78848c83012SMichael S. Tsirkin * If this function is called from an interrupt gfp_mask() must be 78948c83012SMichael S. Tsirkin * %GFP_ATOMIC. 79048c83012SMichael S. Tsirkin * 79148c83012SMichael S. Tsirkin * Returns 0 on success or a negative error code on failure 79248c83012SMichael S. Tsirkin * to allocate kernel memory to copy to. 79348c83012SMichael S. Tsirkin */ 79448c83012SMichael S. Tsirkin int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) 795a6686f2fSShirley Ma { 796a6686f2fSShirley Ma int i; 797a6686f2fSShirley Ma int num_frags = skb_shinfo(skb)->nr_frags; 798a6686f2fSShirley Ma struct page *page, *head = NULL; 799a6686f2fSShirley Ma struct ubuf_info *uarg = skb_shinfo(skb)->destructor_arg; 800a6686f2fSShirley Ma 801a6686f2fSShirley Ma for (i = 0; i < num_frags; i++) { 802a6686f2fSShirley Ma u8 *vaddr; 803a6686f2fSShirley Ma skb_frag_t *f = &skb_shinfo(skb)->frags[i]; 804a6686f2fSShirley Ma 80502756ed4SKrishna Kumar page = alloc_page(gfp_mask); 806a6686f2fSShirley Ma if (!page) { 807a6686f2fSShirley Ma while (head) { 808a6686f2fSShirley Ma struct page *next = (struct page *)head->private; 809a6686f2fSShirley Ma put_page(head); 810a6686f2fSShirley Ma head = next; 811a6686f2fSShirley Ma } 812a6686f2fSShirley Ma return -ENOMEM; 813a6686f2fSShirley Ma } 81451c56b00SEric Dumazet vaddr = kmap_atomic(skb_frag_page(f)); 815a6686f2fSShirley Ma memcpy(page_address(page), 8169e903e08SEric Dumazet vaddr + f->page_offset, skb_frag_size(f)); 81751c56b00SEric Dumazet kunmap_atomic(vaddr); 818a6686f2fSShirley Ma page->private = (unsigned long)head; 819a6686f2fSShirley Ma head = page; 820a6686f2fSShirley Ma } 821a6686f2fSShirley Ma 822a6686f2fSShirley Ma /* skb frags release userspace buffers */ 82302756ed4SKrishna Kumar for (i = 0; i < num_frags; i++) 824a8605c60SIan Campbell skb_frag_unref(skb, i); 825a6686f2fSShirley Ma 826e19d6763SMichael S. Tsirkin uarg->callback(uarg, false); 827a6686f2fSShirley Ma 828a6686f2fSShirley Ma /* skb frags point to kernel buffers */ 82902756ed4SKrishna Kumar for (i = num_frags - 1; i >= 0; i--) { 83002756ed4SKrishna Kumar __skb_fill_page_desc(skb, i, head, 0, 83102756ed4SKrishna Kumar skb_shinfo(skb)->frags[i].size); 832a6686f2fSShirley Ma head = (struct page *)head->private; 833a6686f2fSShirley Ma } 83448c83012SMichael S. Tsirkin 83548c83012SMichael S. Tsirkin skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY; 836a6686f2fSShirley Ma return 0; 837a6686f2fSShirley Ma } 838dcc0fb78SMichael S. Tsirkin EXPORT_SYMBOL_GPL(skb_copy_ubufs); 839a6686f2fSShirley Ma 840e0053ec0SHerbert Xu /** 841e0053ec0SHerbert Xu * skb_clone - duplicate an sk_buff 842e0053ec0SHerbert Xu * @skb: buffer to clone 843e0053ec0SHerbert Xu * @gfp_mask: allocation priority 844e0053ec0SHerbert Xu * 845e0053ec0SHerbert Xu * Duplicate an &sk_buff. The new one is not owned by a socket. Both 846e0053ec0SHerbert Xu * copies share the same packet data but not structure. The new 847e0053ec0SHerbert Xu * buffer has a reference count of 1. If the allocation fails the 848e0053ec0SHerbert Xu * function returns %NULL otherwise the new buffer is returned. 849e0053ec0SHerbert Xu * 850e0053ec0SHerbert Xu * If this function is called from an interrupt gfp_mask() must be 851e0053ec0SHerbert Xu * %GFP_ATOMIC. 852e0053ec0SHerbert Xu */ 853e0053ec0SHerbert Xu 854e0053ec0SHerbert Xu struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask) 855e0053ec0SHerbert Xu { 856e0053ec0SHerbert Xu struct sk_buff *n; 857e0053ec0SHerbert Xu 85870008aa5SMichael S. Tsirkin if (skb_orphan_frags(skb, gfp_mask)) 859a6686f2fSShirley Ma return NULL; 860a6686f2fSShirley Ma 861e0053ec0SHerbert Xu n = skb + 1; 862e0053ec0SHerbert Xu if (skb->fclone == SKB_FCLONE_ORIG && 863e0053ec0SHerbert Xu n->fclone == SKB_FCLONE_UNAVAILABLE) { 864e0053ec0SHerbert Xu atomic_t *fclone_ref = (atomic_t *) (n + 1); 865e0053ec0SHerbert Xu n->fclone = SKB_FCLONE_CLONE; 866e0053ec0SHerbert Xu atomic_inc(fclone_ref); 867e0053ec0SHerbert Xu } else { 868c93bdd0eSMel Gorman if (skb_pfmemalloc(skb)) 869c93bdd0eSMel Gorman gfp_mask |= __GFP_MEMALLOC; 870c93bdd0eSMel Gorman 871e0053ec0SHerbert Xu n = kmem_cache_alloc(skbuff_head_cache, gfp_mask); 872e0053ec0SHerbert Xu if (!n) 873e0053ec0SHerbert Xu return NULL; 874fe55f6d5SVegard Nossum 875fe55f6d5SVegard Nossum kmemcheck_annotate_bitfield(n, flags1); 876fe55f6d5SVegard Nossum kmemcheck_annotate_bitfield(n, flags2); 877e0053ec0SHerbert Xu n->fclone = SKB_FCLONE_UNAVAILABLE; 878e0053ec0SHerbert Xu } 879e0053ec0SHerbert Xu 880e0053ec0SHerbert Xu return __skb_clone(n, skb); 8811da177e4SLinus Torvalds } 882b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_clone); 8831da177e4SLinus Torvalds 8841da177e4SLinus Torvalds static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old) 8851da177e4SLinus Torvalds { 8862e07fa9cSArnaldo Carvalho de Melo #ifndef NET_SKBUFF_DATA_USES_OFFSET 8871da177e4SLinus Torvalds /* 8881da177e4SLinus Torvalds * Shift between the two data areas in bytes 8891da177e4SLinus Torvalds */ 8901da177e4SLinus Torvalds unsigned long offset = new->data - old->data; 8912e07fa9cSArnaldo Carvalho de Melo #endif 892dec18810SHerbert Xu 893dec18810SHerbert Xu __copy_skb_header(new, old); 894dec18810SHerbert Xu 8952e07fa9cSArnaldo Carvalho de Melo #ifndef NET_SKBUFF_DATA_USES_OFFSET 8962e07fa9cSArnaldo Carvalho de Melo /* {transport,network,mac}_header are relative to skb->head */ 8972e07fa9cSArnaldo Carvalho de Melo new->transport_header += offset; 8982e07fa9cSArnaldo Carvalho de Melo new->network_header += offset; 899603a8bbeSStephen Hemminger if (skb_mac_header_was_set(new)) 9002e07fa9cSArnaldo Carvalho de Melo new->mac_header += offset; 9016a674e9cSJoseph Gasparakis new->inner_transport_header += offset; 9026a674e9cSJoseph Gasparakis new->inner_network_header += offset; 9032e07fa9cSArnaldo Carvalho de Melo #endif 9047967168cSHerbert Xu skb_shinfo(new)->gso_size = skb_shinfo(old)->gso_size; 9057967168cSHerbert Xu skb_shinfo(new)->gso_segs = skb_shinfo(old)->gso_segs; 9067967168cSHerbert Xu skb_shinfo(new)->gso_type = skb_shinfo(old)->gso_type; 9071da177e4SLinus Torvalds } 9081da177e4SLinus Torvalds 909c93bdd0eSMel Gorman static inline int skb_alloc_rx_flag(const struct sk_buff *skb) 910c93bdd0eSMel Gorman { 911c93bdd0eSMel Gorman if (skb_pfmemalloc(skb)) 912c93bdd0eSMel Gorman return SKB_ALLOC_RX; 913c93bdd0eSMel Gorman return 0; 914c93bdd0eSMel Gorman } 915c93bdd0eSMel Gorman 9161da177e4SLinus Torvalds /** 9171da177e4SLinus Torvalds * skb_copy - create private copy of an sk_buff 9181da177e4SLinus Torvalds * @skb: buffer to copy 9191da177e4SLinus Torvalds * @gfp_mask: allocation priority 9201da177e4SLinus Torvalds * 9211da177e4SLinus Torvalds * Make a copy of both an &sk_buff and its data. This is used when the 9221da177e4SLinus Torvalds * caller wishes to modify the data and needs a private copy of the 9231da177e4SLinus Torvalds * data to alter. Returns %NULL on failure or the pointer to the buffer 9241da177e4SLinus Torvalds * on success. The returned buffer has a reference count of 1. 9251da177e4SLinus Torvalds * 9261da177e4SLinus Torvalds * As by-product this function converts non-linear &sk_buff to linear 9271da177e4SLinus Torvalds * one, so that &sk_buff becomes completely private and caller is allowed 9281da177e4SLinus Torvalds * to modify all the data of returned buffer. This means that this 9291da177e4SLinus Torvalds * function is not recommended for use in circumstances when only 9301da177e4SLinus Torvalds * header is going to be modified. Use pskb_copy() instead. 9311da177e4SLinus Torvalds */ 9321da177e4SLinus Torvalds 933dd0fc66fSAl Viro struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask) 9341da177e4SLinus Torvalds { 9356602cebbSEric Dumazet int headerlen = skb_headroom(skb); 936ec47ea82SAlexander Duyck unsigned int size = skb_end_offset(skb) + skb->data_len; 937c93bdd0eSMel Gorman struct sk_buff *n = __alloc_skb(size, gfp_mask, 938c93bdd0eSMel Gorman skb_alloc_rx_flag(skb), NUMA_NO_NODE); 9396602cebbSEric Dumazet 9401da177e4SLinus Torvalds if (!n) 9411da177e4SLinus Torvalds return NULL; 9421da177e4SLinus Torvalds 9431da177e4SLinus Torvalds /* Set the data pointer */ 9441da177e4SLinus Torvalds skb_reserve(n, headerlen); 9451da177e4SLinus Torvalds /* Set the tail pointer and length */ 9461da177e4SLinus Torvalds skb_put(n, skb->len); 9471da177e4SLinus Torvalds 9481da177e4SLinus Torvalds if (skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len)) 9491da177e4SLinus Torvalds BUG(); 9501da177e4SLinus Torvalds 9511da177e4SLinus Torvalds copy_skb_header(n, skb); 9521da177e4SLinus Torvalds return n; 9531da177e4SLinus Torvalds } 954b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_copy); 9551da177e4SLinus Torvalds 9561da177e4SLinus Torvalds /** 957117632e6SEric Dumazet * __pskb_copy - create copy of an sk_buff with private head. 9581da177e4SLinus Torvalds * @skb: buffer to copy 959117632e6SEric Dumazet * @headroom: headroom of new skb 9601da177e4SLinus Torvalds * @gfp_mask: allocation priority 9611da177e4SLinus Torvalds * 9621da177e4SLinus Torvalds * Make a copy of both an &sk_buff and part of its data, located 9631da177e4SLinus Torvalds * in header. Fragmented data remain shared. This is used when 9641da177e4SLinus Torvalds * the caller wishes to modify only header of &sk_buff and needs 9651da177e4SLinus Torvalds * private copy of the header to alter. Returns %NULL on failure 9661da177e4SLinus Torvalds * or the pointer to the buffer on success. 9671da177e4SLinus Torvalds * The returned buffer has a reference count of 1. 9681da177e4SLinus Torvalds */ 9691da177e4SLinus Torvalds 970117632e6SEric Dumazet struct sk_buff *__pskb_copy(struct sk_buff *skb, int headroom, gfp_t gfp_mask) 9711da177e4SLinus Torvalds { 972117632e6SEric Dumazet unsigned int size = skb_headlen(skb) + headroom; 973c93bdd0eSMel Gorman struct sk_buff *n = __alloc_skb(size, gfp_mask, 974c93bdd0eSMel Gorman skb_alloc_rx_flag(skb), NUMA_NO_NODE); 9756602cebbSEric Dumazet 9761da177e4SLinus Torvalds if (!n) 9771da177e4SLinus Torvalds goto out; 9781da177e4SLinus Torvalds 9791da177e4SLinus Torvalds /* Set the data pointer */ 980117632e6SEric Dumazet skb_reserve(n, headroom); 9811da177e4SLinus Torvalds /* Set the tail pointer and length */ 9821da177e4SLinus Torvalds skb_put(n, skb_headlen(skb)); 9831da177e4SLinus Torvalds /* Copy the bytes */ 984d626f62bSArnaldo Carvalho de Melo skb_copy_from_linear_data(skb, n->data, n->len); 9851da177e4SLinus Torvalds 98625f484a6SHerbert Xu n->truesize += skb->data_len; 9871da177e4SLinus Torvalds n->data_len = skb->data_len; 9881da177e4SLinus Torvalds n->len = skb->len; 9891da177e4SLinus Torvalds 9901da177e4SLinus Torvalds if (skb_shinfo(skb)->nr_frags) { 9911da177e4SLinus Torvalds int i; 9921da177e4SLinus Torvalds 99370008aa5SMichael S. Tsirkin if (skb_orphan_frags(skb, gfp_mask)) { 9941511022cSDan Carpenter kfree_skb(n); 9951511022cSDan Carpenter n = NULL; 996a6686f2fSShirley Ma goto out; 997a6686f2fSShirley Ma } 9981da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 9991da177e4SLinus Torvalds skb_shinfo(n)->frags[i] = skb_shinfo(skb)->frags[i]; 1000ea2ab693SIan Campbell skb_frag_ref(skb, i); 10011da177e4SLinus Torvalds } 10021da177e4SLinus Torvalds skb_shinfo(n)->nr_frags = i; 10031da177e4SLinus Torvalds } 10041da177e4SLinus Torvalds 100521dc3301SDavid S. Miller if (skb_has_frag_list(skb)) { 10061da177e4SLinus Torvalds skb_shinfo(n)->frag_list = skb_shinfo(skb)->frag_list; 10071da177e4SLinus Torvalds skb_clone_fraglist(n); 10081da177e4SLinus Torvalds } 10091da177e4SLinus Torvalds 10101da177e4SLinus Torvalds copy_skb_header(n, skb); 10111da177e4SLinus Torvalds out: 10121da177e4SLinus Torvalds return n; 10131da177e4SLinus Torvalds } 1014117632e6SEric Dumazet EXPORT_SYMBOL(__pskb_copy); 10151da177e4SLinus Torvalds 10161da177e4SLinus Torvalds /** 10171da177e4SLinus Torvalds * pskb_expand_head - reallocate header of &sk_buff 10181da177e4SLinus Torvalds * @skb: buffer to reallocate 10191da177e4SLinus Torvalds * @nhead: room to add at head 10201da177e4SLinus Torvalds * @ntail: room to add at tail 10211da177e4SLinus Torvalds * @gfp_mask: allocation priority 10221da177e4SLinus Torvalds * 10231da177e4SLinus Torvalds * Expands (or creates identical copy, if &nhead and &ntail are zero) 10241da177e4SLinus Torvalds * header of skb. &sk_buff itself is not changed. &sk_buff MUST have 10251da177e4SLinus Torvalds * reference count of 1. Returns zero in the case of success or error, 10261da177e4SLinus Torvalds * if expansion failed. In the last case, &sk_buff is not changed. 10271da177e4SLinus Torvalds * 10281da177e4SLinus Torvalds * All the pointers pointing into skb header may change and must be 10291da177e4SLinus Torvalds * reloaded after call to this function. 10301da177e4SLinus Torvalds */ 10311da177e4SLinus Torvalds 103286a76cafSVictor Fusco int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, 1033dd0fc66fSAl Viro gfp_t gfp_mask) 10341da177e4SLinus Torvalds { 10351da177e4SLinus Torvalds int i; 10361da177e4SLinus Torvalds u8 *data; 1037ec47ea82SAlexander Duyck int size = nhead + skb_end_offset(skb) + ntail; 10381da177e4SLinus Torvalds long off; 10391da177e4SLinus Torvalds 10404edd87adSHerbert Xu BUG_ON(nhead < 0); 10414edd87adSHerbert Xu 10421da177e4SLinus Torvalds if (skb_shared(skb)) 10431da177e4SLinus Torvalds BUG(); 10441da177e4SLinus Torvalds 10451da177e4SLinus Torvalds size = SKB_DATA_ALIGN(size); 10461da177e4SLinus Torvalds 1047c93bdd0eSMel Gorman if (skb_pfmemalloc(skb)) 1048c93bdd0eSMel Gorman gfp_mask |= __GFP_MEMALLOC; 1049c93bdd0eSMel Gorman data = kmalloc_reserve(size + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)), 1050c93bdd0eSMel Gorman gfp_mask, NUMA_NO_NODE, NULL); 10511da177e4SLinus Torvalds if (!data) 10521da177e4SLinus Torvalds goto nodata; 105387151b86SEric Dumazet size = SKB_WITH_OVERHEAD(ksize(data)); 10541da177e4SLinus Torvalds 10551da177e4SLinus Torvalds /* Copy only real data... and, alas, header. This should be 10566602cebbSEric Dumazet * optimized for the cases when header is void. 10576602cebbSEric Dumazet */ 10586602cebbSEric Dumazet memcpy(data + nhead, skb->head, skb_tail_pointer(skb) - skb->head); 10596602cebbSEric Dumazet 10606602cebbSEric Dumazet memcpy((struct skb_shared_info *)(data + size), 10616602cebbSEric Dumazet skb_shinfo(skb), 1062fed66381SEric Dumazet offsetof(struct skb_shared_info, frags[skb_shinfo(skb)->nr_frags])); 10631da177e4SLinus Torvalds 10643e24591aSAlexander Duyck /* 10653e24591aSAlexander Duyck * if shinfo is shared we must drop the old head gracefully, but if it 10663e24591aSAlexander Duyck * is not we can just drop the old head and let the existing refcount 10673e24591aSAlexander Duyck * be since all we did is relocate the values 10683e24591aSAlexander Duyck */ 10693e24591aSAlexander Duyck if (skb_cloned(skb)) { 1070a6686f2fSShirley Ma /* copy this zero copy skb frags */ 107170008aa5SMichael S. Tsirkin if (skb_orphan_frags(skb, gfp_mask)) 1072a6686f2fSShirley Ma goto nofrags; 10731da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) 1074ea2ab693SIan Campbell skb_frag_ref(skb, i); 10751da177e4SLinus Torvalds 107621dc3301SDavid S. Miller if (skb_has_frag_list(skb)) 10771da177e4SLinus Torvalds skb_clone_fraglist(skb); 10781da177e4SLinus Torvalds 10791da177e4SLinus Torvalds skb_release_data(skb); 10803e24591aSAlexander Duyck } else { 10813e24591aSAlexander Duyck skb_free_head(skb); 10821fd63041SEric Dumazet } 10831da177e4SLinus Torvalds off = (data + nhead) - skb->head; 10841da177e4SLinus Torvalds 10851da177e4SLinus Torvalds skb->head = data; 1086d3836f21SEric Dumazet skb->head_frag = 0; 10871da177e4SLinus Torvalds skb->data += off; 10884305b541SArnaldo Carvalho de Melo #ifdef NET_SKBUFF_DATA_USES_OFFSET 10894305b541SArnaldo Carvalho de Melo skb->end = size; 109056eb8882SPatrick McHardy off = nhead; 10914305b541SArnaldo Carvalho de Melo #else 10924305b541SArnaldo Carvalho de Melo skb->end = skb->head + size; 109356eb8882SPatrick McHardy #endif 109427a884dcSArnaldo Carvalho de Melo /* {transport,network,mac}_header and tail are relative to skb->head */ 109527a884dcSArnaldo Carvalho de Melo skb->tail += off; 1096b0e380b1SArnaldo Carvalho de Melo skb->transport_header += off; 1097b0e380b1SArnaldo Carvalho de Melo skb->network_header += off; 1098603a8bbeSStephen Hemminger if (skb_mac_header_was_set(skb)) 1099b0e380b1SArnaldo Carvalho de Melo skb->mac_header += off; 11006a674e9cSJoseph Gasparakis skb->inner_transport_header += off; 11016a674e9cSJoseph Gasparakis skb->inner_network_header += off; 110200c5a983SAndrea Shepard /* Only adjust this if it actually is csum_start rather than csum */ 110300c5a983SAndrea Shepard if (skb->ip_summed == CHECKSUM_PARTIAL) 1104172a863fSHerbert Xu skb->csum_start += nhead; 11051da177e4SLinus Torvalds skb->cloned = 0; 1106334a8132SPatrick McHardy skb->hdr_len = 0; 11071da177e4SLinus Torvalds skb->nohdr = 0; 11081da177e4SLinus Torvalds atomic_set(&skb_shinfo(skb)->dataref, 1); 11091da177e4SLinus Torvalds return 0; 11101da177e4SLinus Torvalds 1111a6686f2fSShirley Ma nofrags: 1112a6686f2fSShirley Ma kfree(data); 11131da177e4SLinus Torvalds nodata: 11141da177e4SLinus Torvalds return -ENOMEM; 11151da177e4SLinus Torvalds } 1116b4ac530fSDavid S. Miller EXPORT_SYMBOL(pskb_expand_head); 11171da177e4SLinus Torvalds 11181da177e4SLinus Torvalds /* Make private copy of skb with writable head and some headroom */ 11191da177e4SLinus Torvalds 11201da177e4SLinus Torvalds struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, unsigned int headroom) 11211da177e4SLinus Torvalds { 11221da177e4SLinus Torvalds struct sk_buff *skb2; 11231da177e4SLinus Torvalds int delta = headroom - skb_headroom(skb); 11241da177e4SLinus Torvalds 11251da177e4SLinus Torvalds if (delta <= 0) 11261da177e4SLinus Torvalds skb2 = pskb_copy(skb, GFP_ATOMIC); 11271da177e4SLinus Torvalds else { 11281da177e4SLinus Torvalds skb2 = skb_clone(skb, GFP_ATOMIC); 11291da177e4SLinus Torvalds if (skb2 && pskb_expand_head(skb2, SKB_DATA_ALIGN(delta), 0, 11301da177e4SLinus Torvalds GFP_ATOMIC)) { 11311da177e4SLinus Torvalds kfree_skb(skb2); 11321da177e4SLinus Torvalds skb2 = NULL; 11331da177e4SLinus Torvalds } 11341da177e4SLinus Torvalds } 11351da177e4SLinus Torvalds return skb2; 11361da177e4SLinus Torvalds } 1137b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_realloc_headroom); 11381da177e4SLinus Torvalds 11391da177e4SLinus Torvalds /** 11401da177e4SLinus Torvalds * skb_copy_expand - copy and expand sk_buff 11411da177e4SLinus Torvalds * @skb: buffer to copy 11421da177e4SLinus Torvalds * @newheadroom: new free bytes at head 11431da177e4SLinus Torvalds * @newtailroom: new free bytes at tail 11441da177e4SLinus Torvalds * @gfp_mask: allocation priority 11451da177e4SLinus Torvalds * 11461da177e4SLinus Torvalds * Make a copy of both an &sk_buff and its data and while doing so 11471da177e4SLinus Torvalds * allocate additional space. 11481da177e4SLinus Torvalds * 11491da177e4SLinus Torvalds * This is used when the caller wishes to modify the data and needs a 11501da177e4SLinus Torvalds * private copy of the data to alter as well as more space for new fields. 11511da177e4SLinus Torvalds * Returns %NULL on failure or the pointer to the buffer 11521da177e4SLinus Torvalds * on success. The returned buffer has a reference count of 1. 11531da177e4SLinus Torvalds * 11541da177e4SLinus Torvalds * You must pass %GFP_ATOMIC as the allocation priority if this function 11551da177e4SLinus Torvalds * is called from an interrupt. 11561da177e4SLinus Torvalds */ 11571da177e4SLinus Torvalds struct sk_buff *skb_copy_expand(const struct sk_buff *skb, 115886a76cafSVictor Fusco int newheadroom, int newtailroom, 1159dd0fc66fSAl Viro gfp_t gfp_mask) 11601da177e4SLinus Torvalds { 11611da177e4SLinus Torvalds /* 11621da177e4SLinus Torvalds * Allocate the copy buffer 11631da177e4SLinus Torvalds */ 1164c93bdd0eSMel Gorman struct sk_buff *n = __alloc_skb(newheadroom + skb->len + newtailroom, 1165c93bdd0eSMel Gorman gfp_mask, skb_alloc_rx_flag(skb), 1166c93bdd0eSMel Gorman NUMA_NO_NODE); 1167efd1e8d5SPatrick McHardy int oldheadroom = skb_headroom(skb); 11681da177e4SLinus Torvalds int head_copy_len, head_copy_off; 116952886051SHerbert Xu int off; 11701da177e4SLinus Torvalds 11711da177e4SLinus Torvalds if (!n) 11721da177e4SLinus Torvalds return NULL; 11731da177e4SLinus Torvalds 11741da177e4SLinus Torvalds skb_reserve(n, newheadroom); 11751da177e4SLinus Torvalds 11761da177e4SLinus Torvalds /* Set the tail pointer and length */ 11771da177e4SLinus Torvalds skb_put(n, skb->len); 11781da177e4SLinus Torvalds 1179efd1e8d5SPatrick McHardy head_copy_len = oldheadroom; 11801da177e4SLinus Torvalds head_copy_off = 0; 11811da177e4SLinus Torvalds if (newheadroom <= head_copy_len) 11821da177e4SLinus Torvalds head_copy_len = newheadroom; 11831da177e4SLinus Torvalds else 11841da177e4SLinus Torvalds head_copy_off = newheadroom - head_copy_len; 11851da177e4SLinus Torvalds 11861da177e4SLinus Torvalds /* Copy the linear header and data. */ 11871da177e4SLinus Torvalds if (skb_copy_bits(skb, -head_copy_len, n->head + head_copy_off, 11881da177e4SLinus Torvalds skb->len + head_copy_len)) 11891da177e4SLinus Torvalds BUG(); 11901da177e4SLinus Torvalds 11911da177e4SLinus Torvalds copy_skb_header(n, skb); 11921da177e4SLinus Torvalds 1193efd1e8d5SPatrick McHardy off = newheadroom - oldheadroom; 1194be2b6e62SDavid S. Miller if (n->ip_summed == CHECKSUM_PARTIAL) 119552886051SHerbert Xu n->csum_start += off; 119652886051SHerbert Xu #ifdef NET_SKBUFF_DATA_USES_OFFSET 1197efd1e8d5SPatrick McHardy n->transport_header += off; 1198efd1e8d5SPatrick McHardy n->network_header += off; 1199603a8bbeSStephen Hemminger if (skb_mac_header_was_set(skb)) 1200efd1e8d5SPatrick McHardy n->mac_header += off; 12016a674e9cSJoseph Gasparakis n->inner_transport_header += off; 12026a674e9cSJoseph Gasparakis n->inner_network_header += off; 120352886051SHerbert Xu #endif 1204efd1e8d5SPatrick McHardy 12051da177e4SLinus Torvalds return n; 12061da177e4SLinus Torvalds } 1207b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_copy_expand); 12081da177e4SLinus Torvalds 12091da177e4SLinus Torvalds /** 12101da177e4SLinus Torvalds * skb_pad - zero pad the tail of an skb 12111da177e4SLinus Torvalds * @skb: buffer to pad 12121da177e4SLinus Torvalds * @pad: space to pad 12131da177e4SLinus Torvalds * 12141da177e4SLinus Torvalds * Ensure that a buffer is followed by a padding area that is zero 12151da177e4SLinus Torvalds * filled. Used by network drivers which may DMA or transfer data 12161da177e4SLinus Torvalds * beyond the buffer end onto the wire. 12171da177e4SLinus Torvalds * 12185b057c6bSHerbert Xu * May return error in out of memory cases. The skb is freed on error. 12191da177e4SLinus Torvalds */ 12201da177e4SLinus Torvalds 12215b057c6bSHerbert Xu int skb_pad(struct sk_buff *skb, int pad) 12221da177e4SLinus Torvalds { 12235b057c6bSHerbert Xu int err; 12245b057c6bSHerbert Xu int ntail; 12251da177e4SLinus Torvalds 12261da177e4SLinus Torvalds /* If the skbuff is non linear tailroom is always zero.. */ 12275b057c6bSHerbert Xu if (!skb_cloned(skb) && skb_tailroom(skb) >= pad) { 12281da177e4SLinus Torvalds memset(skb->data+skb->len, 0, pad); 12295b057c6bSHerbert Xu return 0; 12301da177e4SLinus Torvalds } 12311da177e4SLinus Torvalds 12324305b541SArnaldo Carvalho de Melo ntail = skb->data_len + pad - (skb->end - skb->tail); 12335b057c6bSHerbert Xu if (likely(skb_cloned(skb) || ntail > 0)) { 12345b057c6bSHerbert Xu err = pskb_expand_head(skb, 0, ntail, GFP_ATOMIC); 12355b057c6bSHerbert Xu if (unlikely(err)) 12365b057c6bSHerbert Xu goto free_skb; 12375b057c6bSHerbert Xu } 12385b057c6bSHerbert Xu 12395b057c6bSHerbert Xu /* FIXME: The use of this function with non-linear skb's really needs 12405b057c6bSHerbert Xu * to be audited. 12415b057c6bSHerbert Xu */ 12425b057c6bSHerbert Xu err = skb_linearize(skb); 12435b057c6bSHerbert Xu if (unlikely(err)) 12445b057c6bSHerbert Xu goto free_skb; 12455b057c6bSHerbert Xu 12465b057c6bSHerbert Xu memset(skb->data + skb->len, 0, pad); 12475b057c6bSHerbert Xu return 0; 12485b057c6bSHerbert Xu 12495b057c6bSHerbert Xu free_skb: 12501da177e4SLinus Torvalds kfree_skb(skb); 12515b057c6bSHerbert Xu return err; 12521da177e4SLinus Torvalds } 1253b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_pad); 12541da177e4SLinus Torvalds 12550dde3e16SIlpo Järvinen /** 12560dde3e16SIlpo Järvinen * skb_put - add data to a buffer 12570dde3e16SIlpo Järvinen * @skb: buffer to use 12580dde3e16SIlpo Järvinen * @len: amount of data to add 12590dde3e16SIlpo Järvinen * 12600dde3e16SIlpo Järvinen * This function extends the used data area of the buffer. If this would 12610dde3e16SIlpo Järvinen * exceed the total buffer size the kernel will panic. A pointer to the 12620dde3e16SIlpo Järvinen * first byte of the extra data is returned. 12630dde3e16SIlpo Järvinen */ 12640dde3e16SIlpo Järvinen unsigned char *skb_put(struct sk_buff *skb, unsigned int len) 12650dde3e16SIlpo Järvinen { 12660dde3e16SIlpo Järvinen unsigned char *tmp = skb_tail_pointer(skb); 12670dde3e16SIlpo Järvinen SKB_LINEAR_ASSERT(skb); 12680dde3e16SIlpo Järvinen skb->tail += len; 12690dde3e16SIlpo Järvinen skb->len += len; 12700dde3e16SIlpo Järvinen if (unlikely(skb->tail > skb->end)) 12710dde3e16SIlpo Järvinen skb_over_panic(skb, len, __builtin_return_address(0)); 12720dde3e16SIlpo Järvinen return tmp; 12730dde3e16SIlpo Järvinen } 12740dde3e16SIlpo Järvinen EXPORT_SYMBOL(skb_put); 12750dde3e16SIlpo Järvinen 12766be8ac2fSIlpo Järvinen /** 1277c2aa270aSIlpo Järvinen * skb_push - add data to the start of a buffer 1278c2aa270aSIlpo Järvinen * @skb: buffer to use 1279c2aa270aSIlpo Järvinen * @len: amount of data to add 1280c2aa270aSIlpo Järvinen * 1281c2aa270aSIlpo Järvinen * This function extends the used data area of the buffer at the buffer 1282c2aa270aSIlpo Järvinen * start. If this would exceed the total buffer headroom the kernel will 1283c2aa270aSIlpo Järvinen * panic. A pointer to the first byte of the extra data is returned. 1284c2aa270aSIlpo Järvinen */ 1285c2aa270aSIlpo Järvinen unsigned char *skb_push(struct sk_buff *skb, unsigned int len) 1286c2aa270aSIlpo Järvinen { 1287c2aa270aSIlpo Järvinen skb->data -= len; 1288c2aa270aSIlpo Järvinen skb->len += len; 1289c2aa270aSIlpo Järvinen if (unlikely(skb->data<skb->head)) 1290c2aa270aSIlpo Järvinen skb_under_panic(skb, len, __builtin_return_address(0)); 1291c2aa270aSIlpo Järvinen return skb->data; 1292c2aa270aSIlpo Järvinen } 1293c2aa270aSIlpo Järvinen EXPORT_SYMBOL(skb_push); 1294c2aa270aSIlpo Järvinen 1295c2aa270aSIlpo Järvinen /** 12966be8ac2fSIlpo Järvinen * skb_pull - remove data from the start of a buffer 12976be8ac2fSIlpo Järvinen * @skb: buffer to use 12986be8ac2fSIlpo Järvinen * @len: amount of data to remove 12996be8ac2fSIlpo Järvinen * 13006be8ac2fSIlpo Järvinen * This function removes data from the start of a buffer, returning 13016be8ac2fSIlpo Järvinen * the memory to the headroom. A pointer to the next data in the buffer 13026be8ac2fSIlpo Järvinen * is returned. Once the data has been pulled future pushes will overwrite 13036be8ac2fSIlpo Järvinen * the old data. 13046be8ac2fSIlpo Järvinen */ 13056be8ac2fSIlpo Järvinen unsigned char *skb_pull(struct sk_buff *skb, unsigned int len) 13066be8ac2fSIlpo Järvinen { 130747d29646SDavid S. Miller return skb_pull_inline(skb, len); 13086be8ac2fSIlpo Järvinen } 13096be8ac2fSIlpo Järvinen EXPORT_SYMBOL(skb_pull); 13106be8ac2fSIlpo Järvinen 1311419ae74eSIlpo Järvinen /** 1312419ae74eSIlpo Järvinen * skb_trim - remove end from a buffer 1313419ae74eSIlpo Järvinen * @skb: buffer to alter 1314419ae74eSIlpo Järvinen * @len: new length 1315419ae74eSIlpo Järvinen * 1316419ae74eSIlpo Järvinen * Cut the length of a buffer down by removing data from the tail. If 1317419ae74eSIlpo Järvinen * the buffer is already under the length specified it is not modified. 1318419ae74eSIlpo Järvinen * The skb must be linear. 1319419ae74eSIlpo Järvinen */ 1320419ae74eSIlpo Järvinen void skb_trim(struct sk_buff *skb, unsigned int len) 1321419ae74eSIlpo Järvinen { 1322419ae74eSIlpo Järvinen if (skb->len > len) 1323419ae74eSIlpo Järvinen __skb_trim(skb, len); 1324419ae74eSIlpo Järvinen } 1325419ae74eSIlpo Järvinen EXPORT_SYMBOL(skb_trim); 1326419ae74eSIlpo Järvinen 13273cc0e873SHerbert Xu /* Trims skb to length len. It can change skb pointers. 13281da177e4SLinus Torvalds */ 13291da177e4SLinus Torvalds 13303cc0e873SHerbert Xu int ___pskb_trim(struct sk_buff *skb, unsigned int len) 13311da177e4SLinus Torvalds { 133227b437c8SHerbert Xu struct sk_buff **fragp; 133327b437c8SHerbert Xu struct sk_buff *frag; 13341da177e4SLinus Torvalds int offset = skb_headlen(skb); 13351da177e4SLinus Torvalds int nfrags = skb_shinfo(skb)->nr_frags; 13361da177e4SLinus Torvalds int i; 133727b437c8SHerbert Xu int err; 133827b437c8SHerbert Xu 133927b437c8SHerbert Xu if (skb_cloned(skb) && 134027b437c8SHerbert Xu unlikely((err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))) 134127b437c8SHerbert Xu return err; 13421da177e4SLinus Torvalds 1343f4d26fb3SHerbert Xu i = 0; 1344f4d26fb3SHerbert Xu if (offset >= len) 1345f4d26fb3SHerbert Xu goto drop_pages; 1346f4d26fb3SHerbert Xu 1347f4d26fb3SHerbert Xu for (; i < nfrags; i++) { 13489e903e08SEric Dumazet int end = offset + skb_frag_size(&skb_shinfo(skb)->frags[i]); 134927b437c8SHerbert Xu 135027b437c8SHerbert Xu if (end < len) { 13511da177e4SLinus Torvalds offset = end; 135227b437c8SHerbert Xu continue; 13531da177e4SLinus Torvalds } 13541da177e4SLinus Torvalds 13559e903e08SEric Dumazet skb_frag_size_set(&skb_shinfo(skb)->frags[i++], len - offset); 135627b437c8SHerbert Xu 1357f4d26fb3SHerbert Xu drop_pages: 135827b437c8SHerbert Xu skb_shinfo(skb)->nr_frags = i; 135927b437c8SHerbert Xu 136027b437c8SHerbert Xu for (; i < nfrags; i++) 1361ea2ab693SIan Campbell skb_frag_unref(skb, i); 136227b437c8SHerbert Xu 136321dc3301SDavid S. Miller if (skb_has_frag_list(skb)) 136427b437c8SHerbert Xu skb_drop_fraglist(skb); 1365f4d26fb3SHerbert Xu goto done; 136627b437c8SHerbert Xu } 136727b437c8SHerbert Xu 136827b437c8SHerbert Xu for (fragp = &skb_shinfo(skb)->frag_list; (frag = *fragp); 136927b437c8SHerbert Xu fragp = &frag->next) { 137027b437c8SHerbert Xu int end = offset + frag->len; 137127b437c8SHerbert Xu 137227b437c8SHerbert Xu if (skb_shared(frag)) { 137327b437c8SHerbert Xu struct sk_buff *nfrag; 137427b437c8SHerbert Xu 137527b437c8SHerbert Xu nfrag = skb_clone(frag, GFP_ATOMIC); 137627b437c8SHerbert Xu if (unlikely(!nfrag)) 137727b437c8SHerbert Xu return -ENOMEM; 137827b437c8SHerbert Xu 137927b437c8SHerbert Xu nfrag->next = frag->next; 138085bb2a60SEric Dumazet consume_skb(frag); 138127b437c8SHerbert Xu frag = nfrag; 138227b437c8SHerbert Xu *fragp = frag; 138327b437c8SHerbert Xu } 138427b437c8SHerbert Xu 138527b437c8SHerbert Xu if (end < len) { 138627b437c8SHerbert Xu offset = end; 138727b437c8SHerbert Xu continue; 138827b437c8SHerbert Xu } 138927b437c8SHerbert Xu 139027b437c8SHerbert Xu if (end > len && 139127b437c8SHerbert Xu unlikely((err = pskb_trim(frag, len - offset)))) 139227b437c8SHerbert Xu return err; 139327b437c8SHerbert Xu 139427b437c8SHerbert Xu if (frag->next) 139527b437c8SHerbert Xu skb_drop_list(&frag->next); 139627b437c8SHerbert Xu break; 139727b437c8SHerbert Xu } 139827b437c8SHerbert Xu 1399f4d26fb3SHerbert Xu done: 140027b437c8SHerbert Xu if (len > skb_headlen(skb)) { 14011da177e4SLinus Torvalds skb->data_len -= skb->len - len; 14021da177e4SLinus Torvalds skb->len = len; 14031da177e4SLinus Torvalds } else { 14041da177e4SLinus Torvalds skb->len = len; 14051da177e4SLinus Torvalds skb->data_len = 0; 140627a884dcSArnaldo Carvalho de Melo skb_set_tail_pointer(skb, len); 14071da177e4SLinus Torvalds } 14081da177e4SLinus Torvalds 14091da177e4SLinus Torvalds return 0; 14101da177e4SLinus Torvalds } 1411b4ac530fSDavid S. Miller EXPORT_SYMBOL(___pskb_trim); 14121da177e4SLinus Torvalds 14131da177e4SLinus Torvalds /** 14141da177e4SLinus Torvalds * __pskb_pull_tail - advance tail of skb header 14151da177e4SLinus Torvalds * @skb: buffer to reallocate 14161da177e4SLinus Torvalds * @delta: number of bytes to advance tail 14171da177e4SLinus Torvalds * 14181da177e4SLinus Torvalds * The function makes a sense only on a fragmented &sk_buff, 14191da177e4SLinus Torvalds * it expands header moving its tail forward and copying necessary 14201da177e4SLinus Torvalds * data from fragmented part. 14211da177e4SLinus Torvalds * 14221da177e4SLinus Torvalds * &sk_buff MUST have reference count of 1. 14231da177e4SLinus Torvalds * 14241da177e4SLinus Torvalds * Returns %NULL (and &sk_buff does not change) if pull failed 14251da177e4SLinus Torvalds * or value of new tail of skb in the case of success. 14261da177e4SLinus Torvalds * 14271da177e4SLinus Torvalds * All the pointers pointing into skb header may change and must be 14281da177e4SLinus Torvalds * reloaded after call to this function. 14291da177e4SLinus Torvalds */ 14301da177e4SLinus Torvalds 14311da177e4SLinus Torvalds /* Moves tail of skb head forward, copying data from fragmented part, 14321da177e4SLinus Torvalds * when it is necessary. 14331da177e4SLinus Torvalds * 1. It may fail due to malloc failure. 14341da177e4SLinus Torvalds * 2. It may change skb pointers. 14351da177e4SLinus Torvalds * 14361da177e4SLinus Torvalds * It is pretty complicated. Luckily, it is called only in exceptional cases. 14371da177e4SLinus Torvalds */ 14381da177e4SLinus Torvalds unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta) 14391da177e4SLinus Torvalds { 14401da177e4SLinus Torvalds /* If skb has not enough free space at tail, get new one 14411da177e4SLinus Torvalds * plus 128 bytes for future expansions. If we have enough 14421da177e4SLinus Torvalds * room at tail, reallocate without expansion only if skb is cloned. 14431da177e4SLinus Torvalds */ 14444305b541SArnaldo Carvalho de Melo int i, k, eat = (skb->tail + delta) - skb->end; 14451da177e4SLinus Torvalds 14461da177e4SLinus Torvalds if (eat > 0 || skb_cloned(skb)) { 14471da177e4SLinus Torvalds if (pskb_expand_head(skb, 0, eat > 0 ? eat + 128 : 0, 14481da177e4SLinus Torvalds GFP_ATOMIC)) 14491da177e4SLinus Torvalds return NULL; 14501da177e4SLinus Torvalds } 14511da177e4SLinus Torvalds 145227a884dcSArnaldo Carvalho de Melo if (skb_copy_bits(skb, skb_headlen(skb), skb_tail_pointer(skb), delta)) 14531da177e4SLinus Torvalds BUG(); 14541da177e4SLinus Torvalds 14551da177e4SLinus Torvalds /* Optimization: no fragments, no reasons to preestimate 14561da177e4SLinus Torvalds * size of pulled pages. Superb. 14571da177e4SLinus Torvalds */ 145821dc3301SDavid S. Miller if (!skb_has_frag_list(skb)) 14591da177e4SLinus Torvalds goto pull_pages; 14601da177e4SLinus Torvalds 14611da177e4SLinus Torvalds /* Estimate size of pulled pages. */ 14621da177e4SLinus Torvalds eat = delta; 14631da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 14649e903e08SEric Dumazet int size = skb_frag_size(&skb_shinfo(skb)->frags[i]); 14659e903e08SEric Dumazet 14669e903e08SEric Dumazet if (size >= eat) 14671da177e4SLinus Torvalds goto pull_pages; 14689e903e08SEric Dumazet eat -= size; 14691da177e4SLinus Torvalds } 14701da177e4SLinus Torvalds 14711da177e4SLinus Torvalds /* If we need update frag list, we are in troubles. 14721da177e4SLinus Torvalds * Certainly, it possible to add an offset to skb data, 14731da177e4SLinus Torvalds * but taking into account that pulling is expected to 14741da177e4SLinus Torvalds * be very rare operation, it is worth to fight against 14751da177e4SLinus Torvalds * further bloating skb head and crucify ourselves here instead. 14761da177e4SLinus Torvalds * Pure masohism, indeed. 8)8) 14771da177e4SLinus Torvalds */ 14781da177e4SLinus Torvalds if (eat) { 14791da177e4SLinus Torvalds struct sk_buff *list = skb_shinfo(skb)->frag_list; 14801da177e4SLinus Torvalds struct sk_buff *clone = NULL; 14811da177e4SLinus Torvalds struct sk_buff *insp = NULL; 14821da177e4SLinus Torvalds 14831da177e4SLinus Torvalds do { 148409a62660SKris Katterjohn BUG_ON(!list); 14851da177e4SLinus Torvalds 14861da177e4SLinus Torvalds if (list->len <= eat) { 14871da177e4SLinus Torvalds /* Eaten as whole. */ 14881da177e4SLinus Torvalds eat -= list->len; 14891da177e4SLinus Torvalds list = list->next; 14901da177e4SLinus Torvalds insp = list; 14911da177e4SLinus Torvalds } else { 14921da177e4SLinus Torvalds /* Eaten partially. */ 14931da177e4SLinus Torvalds 14941da177e4SLinus Torvalds if (skb_shared(list)) { 14951da177e4SLinus Torvalds /* Sucks! We need to fork list. :-( */ 14961da177e4SLinus Torvalds clone = skb_clone(list, GFP_ATOMIC); 14971da177e4SLinus Torvalds if (!clone) 14981da177e4SLinus Torvalds return NULL; 14991da177e4SLinus Torvalds insp = list->next; 15001da177e4SLinus Torvalds list = clone; 15011da177e4SLinus Torvalds } else { 15021da177e4SLinus Torvalds /* This may be pulled without 15031da177e4SLinus Torvalds * problems. */ 15041da177e4SLinus Torvalds insp = list; 15051da177e4SLinus Torvalds } 15061da177e4SLinus Torvalds if (!pskb_pull(list, eat)) { 15071da177e4SLinus Torvalds kfree_skb(clone); 15081da177e4SLinus Torvalds return NULL; 15091da177e4SLinus Torvalds } 15101da177e4SLinus Torvalds break; 15111da177e4SLinus Torvalds } 15121da177e4SLinus Torvalds } while (eat); 15131da177e4SLinus Torvalds 15141da177e4SLinus Torvalds /* Free pulled out fragments. */ 15151da177e4SLinus Torvalds while ((list = skb_shinfo(skb)->frag_list) != insp) { 15161da177e4SLinus Torvalds skb_shinfo(skb)->frag_list = list->next; 15171da177e4SLinus Torvalds kfree_skb(list); 15181da177e4SLinus Torvalds } 15191da177e4SLinus Torvalds /* And insert new clone at head. */ 15201da177e4SLinus Torvalds if (clone) { 15211da177e4SLinus Torvalds clone->next = list; 15221da177e4SLinus Torvalds skb_shinfo(skb)->frag_list = clone; 15231da177e4SLinus Torvalds } 15241da177e4SLinus Torvalds } 15251da177e4SLinus Torvalds /* Success! Now we may commit changes to skb data. */ 15261da177e4SLinus Torvalds 15271da177e4SLinus Torvalds pull_pages: 15281da177e4SLinus Torvalds eat = delta; 15291da177e4SLinus Torvalds k = 0; 15301da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 15319e903e08SEric Dumazet int size = skb_frag_size(&skb_shinfo(skb)->frags[i]); 15329e903e08SEric Dumazet 15339e903e08SEric Dumazet if (size <= eat) { 1534ea2ab693SIan Campbell skb_frag_unref(skb, i); 15359e903e08SEric Dumazet eat -= size; 15361da177e4SLinus Torvalds } else { 15371da177e4SLinus Torvalds skb_shinfo(skb)->frags[k] = skb_shinfo(skb)->frags[i]; 15381da177e4SLinus Torvalds if (eat) { 15391da177e4SLinus Torvalds skb_shinfo(skb)->frags[k].page_offset += eat; 15409e903e08SEric Dumazet skb_frag_size_sub(&skb_shinfo(skb)->frags[k], eat); 15411da177e4SLinus Torvalds eat = 0; 15421da177e4SLinus Torvalds } 15431da177e4SLinus Torvalds k++; 15441da177e4SLinus Torvalds } 15451da177e4SLinus Torvalds } 15461da177e4SLinus Torvalds skb_shinfo(skb)->nr_frags = k; 15471da177e4SLinus Torvalds 15481da177e4SLinus Torvalds skb->tail += delta; 15491da177e4SLinus Torvalds skb->data_len -= delta; 15501da177e4SLinus Torvalds 155127a884dcSArnaldo Carvalho de Melo return skb_tail_pointer(skb); 15521da177e4SLinus Torvalds } 1553b4ac530fSDavid S. Miller EXPORT_SYMBOL(__pskb_pull_tail); 15541da177e4SLinus Torvalds 155522019b17SEric Dumazet /** 155622019b17SEric Dumazet * skb_copy_bits - copy bits from skb to kernel buffer 155722019b17SEric Dumazet * @skb: source skb 155822019b17SEric Dumazet * @offset: offset in source 155922019b17SEric Dumazet * @to: destination buffer 156022019b17SEric Dumazet * @len: number of bytes to copy 156122019b17SEric Dumazet * 156222019b17SEric Dumazet * Copy the specified number of bytes from the source skb to the 156322019b17SEric Dumazet * destination buffer. 156422019b17SEric Dumazet * 156522019b17SEric Dumazet * CAUTION ! : 156622019b17SEric Dumazet * If its prototype is ever changed, 156722019b17SEric Dumazet * check arch/{*}/net/{*}.S files, 156822019b17SEric Dumazet * since it is called from BPF assembly code. 156922019b17SEric Dumazet */ 15701da177e4SLinus Torvalds int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len) 15711da177e4SLinus Torvalds { 15721a028e50SDavid S. Miller int start = skb_headlen(skb); 1573fbb398a8SDavid S. Miller struct sk_buff *frag_iter; 1574fbb398a8SDavid S. Miller int i, copy; 15751da177e4SLinus Torvalds 15761da177e4SLinus Torvalds if (offset > (int)skb->len - len) 15771da177e4SLinus Torvalds goto fault; 15781da177e4SLinus Torvalds 15791da177e4SLinus Torvalds /* Copy header. */ 15801a028e50SDavid S. Miller if ((copy = start - offset) > 0) { 15811da177e4SLinus Torvalds if (copy > len) 15821da177e4SLinus Torvalds copy = len; 1583d626f62bSArnaldo Carvalho de Melo skb_copy_from_linear_data_offset(skb, offset, to, copy); 15841da177e4SLinus Torvalds if ((len -= copy) == 0) 15851da177e4SLinus Torvalds return 0; 15861da177e4SLinus Torvalds offset += copy; 15871da177e4SLinus Torvalds to += copy; 15881da177e4SLinus Torvalds } 15891da177e4SLinus Torvalds 15901da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 15911a028e50SDavid S. Miller int end; 159251c56b00SEric Dumazet skb_frag_t *f = &skb_shinfo(skb)->frags[i]; 15931da177e4SLinus Torvalds 1594547b792cSIlpo Järvinen WARN_ON(start > offset + len); 15951a028e50SDavid S. Miller 159651c56b00SEric Dumazet end = start + skb_frag_size(f); 15971da177e4SLinus Torvalds if ((copy = end - offset) > 0) { 15981da177e4SLinus Torvalds u8 *vaddr; 15991da177e4SLinus Torvalds 16001da177e4SLinus Torvalds if (copy > len) 16011da177e4SLinus Torvalds copy = len; 16021da177e4SLinus Torvalds 160351c56b00SEric Dumazet vaddr = kmap_atomic(skb_frag_page(f)); 16041da177e4SLinus Torvalds memcpy(to, 160551c56b00SEric Dumazet vaddr + f->page_offset + offset - start, 160651c56b00SEric Dumazet copy); 160751c56b00SEric Dumazet kunmap_atomic(vaddr); 16081da177e4SLinus Torvalds 16091da177e4SLinus Torvalds if ((len -= copy) == 0) 16101da177e4SLinus Torvalds return 0; 16111da177e4SLinus Torvalds offset += copy; 16121da177e4SLinus Torvalds to += copy; 16131da177e4SLinus Torvalds } 16141a028e50SDavid S. Miller start = end; 16151da177e4SLinus Torvalds } 16161da177e4SLinus Torvalds 1617fbb398a8SDavid S. Miller skb_walk_frags(skb, frag_iter) { 16181a028e50SDavid S. Miller int end; 16191da177e4SLinus Torvalds 1620547b792cSIlpo Järvinen WARN_ON(start > offset + len); 16211a028e50SDavid S. Miller 1622fbb398a8SDavid S. Miller end = start + frag_iter->len; 16231da177e4SLinus Torvalds if ((copy = end - offset) > 0) { 16241da177e4SLinus Torvalds if (copy > len) 16251da177e4SLinus Torvalds copy = len; 1626fbb398a8SDavid S. Miller if (skb_copy_bits(frag_iter, offset - start, to, copy)) 16271da177e4SLinus Torvalds goto fault; 16281da177e4SLinus Torvalds if ((len -= copy) == 0) 16291da177e4SLinus Torvalds return 0; 16301da177e4SLinus Torvalds offset += copy; 16311da177e4SLinus Torvalds to += copy; 16321da177e4SLinus Torvalds } 16331a028e50SDavid S. Miller start = end; 16341da177e4SLinus Torvalds } 1635a6686f2fSShirley Ma 16361da177e4SLinus Torvalds if (!len) 16371da177e4SLinus Torvalds return 0; 16381da177e4SLinus Torvalds 16391da177e4SLinus Torvalds fault: 16401da177e4SLinus Torvalds return -EFAULT; 16411da177e4SLinus Torvalds } 1642b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_copy_bits); 16431da177e4SLinus Torvalds 16449c55e01cSJens Axboe /* 16459c55e01cSJens Axboe * Callback from splice_to_pipe(), if we need to release some pages 16469c55e01cSJens Axboe * at the end of the spd in case we error'ed out in filling the pipe. 16479c55e01cSJens Axboe */ 16489c55e01cSJens Axboe static void sock_spd_release(struct splice_pipe_desc *spd, unsigned int i) 16499c55e01cSJens Axboe { 16508b9d3728SJarek Poplawski put_page(spd->pages[i]); 16518b9d3728SJarek Poplawski } 16529c55e01cSJens Axboe 1653a108d5f3SDavid S. Miller static struct page *linear_to_page(struct page *page, unsigned int *len, 16544fb66994SJarek Poplawski unsigned int *offset, 165518aafc62SEric Dumazet struct sock *sk) 16568b9d3728SJarek Poplawski { 16575640f768SEric Dumazet struct page_frag *pfrag = sk_page_frag(sk); 16588b9d3728SJarek Poplawski 16595640f768SEric Dumazet if (!sk_page_frag_refill(sk, pfrag)) 16608b9d3728SJarek Poplawski return NULL; 16614fb66994SJarek Poplawski 16625640f768SEric Dumazet *len = min_t(unsigned int, *len, pfrag->size - pfrag->offset); 16634fb66994SJarek Poplawski 16645640f768SEric Dumazet memcpy(page_address(pfrag->page) + pfrag->offset, 16655640f768SEric Dumazet page_address(page) + *offset, *len); 16665640f768SEric Dumazet *offset = pfrag->offset; 16675640f768SEric Dumazet pfrag->offset += *len; 16684fb66994SJarek Poplawski 16695640f768SEric Dumazet return pfrag->page; 16709c55e01cSJens Axboe } 16719c55e01cSJens Axboe 167241c73a0dSEric Dumazet static bool spd_can_coalesce(const struct splice_pipe_desc *spd, 167341c73a0dSEric Dumazet struct page *page, 167441c73a0dSEric Dumazet unsigned int offset) 167541c73a0dSEric Dumazet { 167641c73a0dSEric Dumazet return spd->nr_pages && 167741c73a0dSEric Dumazet spd->pages[spd->nr_pages - 1] == page && 167841c73a0dSEric Dumazet (spd->partial[spd->nr_pages - 1].offset + 167941c73a0dSEric Dumazet spd->partial[spd->nr_pages - 1].len == offset); 168041c73a0dSEric Dumazet } 168141c73a0dSEric Dumazet 16829c55e01cSJens Axboe /* 16839c55e01cSJens Axboe * Fill page/offset/length into spd, if it can hold more pages. 16849c55e01cSJens Axboe */ 1685a108d5f3SDavid S. Miller static bool spd_fill_page(struct splice_pipe_desc *spd, 168635f3d14dSJens Axboe struct pipe_inode_info *pipe, struct page *page, 16874fb66994SJarek Poplawski unsigned int *len, unsigned int offset, 168818aafc62SEric Dumazet bool linear, 16897a67e56fSJarek Poplawski struct sock *sk) 16909c55e01cSJens Axboe { 169141c73a0dSEric Dumazet if (unlikely(spd->nr_pages == MAX_SKB_FRAGS)) 1692a108d5f3SDavid S. Miller return true; 16939c55e01cSJens Axboe 16948b9d3728SJarek Poplawski if (linear) { 169518aafc62SEric Dumazet page = linear_to_page(page, len, &offset, sk); 16968b9d3728SJarek Poplawski if (!page) 1697a108d5f3SDavid S. Miller return true; 169841c73a0dSEric Dumazet } 169941c73a0dSEric Dumazet if (spd_can_coalesce(spd, page, offset)) { 170041c73a0dSEric Dumazet spd->partial[spd->nr_pages - 1].len += *len; 1701a108d5f3SDavid S. Miller return false; 170241c73a0dSEric Dumazet } 17038b9d3728SJarek Poplawski get_page(page); 17049c55e01cSJens Axboe spd->pages[spd->nr_pages] = page; 17054fb66994SJarek Poplawski spd->partial[spd->nr_pages].len = *len; 17069c55e01cSJens Axboe spd->partial[spd->nr_pages].offset = offset; 17079c55e01cSJens Axboe spd->nr_pages++; 17088b9d3728SJarek Poplawski 1709a108d5f3SDavid S. Miller return false; 17109c55e01cSJens Axboe } 17119c55e01cSJens Axboe 1712a108d5f3SDavid S. Miller static bool __splice_segment(struct page *page, unsigned int poff, 17132870c43dSOctavian Purdila unsigned int plen, unsigned int *off, 171418aafc62SEric Dumazet unsigned int *len, 1715d7ccf7c0SEric Dumazet struct splice_pipe_desc *spd, bool linear, 171635f3d14dSJens Axboe struct sock *sk, 171735f3d14dSJens Axboe struct pipe_inode_info *pipe) 17189c55e01cSJens Axboe { 17192870c43dSOctavian Purdila if (!*len) 1720a108d5f3SDavid S. Miller return true; 17219c55e01cSJens Axboe 17222870c43dSOctavian Purdila /* skip this segment if already processed */ 17232870c43dSOctavian Purdila if (*off >= plen) { 17242870c43dSOctavian Purdila *off -= plen; 1725a108d5f3SDavid S. Miller return false; 17262870c43dSOctavian Purdila } 17272870c43dSOctavian Purdila 17282870c43dSOctavian Purdila /* ignore any bits we already processed */ 17299ca1b22dSEric Dumazet poff += *off; 17309ca1b22dSEric Dumazet plen -= *off; 17312870c43dSOctavian Purdila *off = 0; 17322870c43dSOctavian Purdila 173318aafc62SEric Dumazet do { 173418aafc62SEric Dumazet unsigned int flen = min(*len, plen); 17352870c43dSOctavian Purdila 173618aafc62SEric Dumazet if (spd_fill_page(spd, pipe, page, &flen, poff, 173718aafc62SEric Dumazet linear, sk)) 1738a108d5f3SDavid S. Miller return true; 173918aafc62SEric Dumazet poff += flen; 174018aafc62SEric Dumazet plen -= flen; 17412870c43dSOctavian Purdila *len -= flen; 174218aafc62SEric Dumazet } while (*len && plen); 17432870c43dSOctavian Purdila 1744a108d5f3SDavid S. Miller return false; 1745db43a282SOctavian Purdila } 17469c55e01cSJens Axboe 17479c55e01cSJens Axboe /* 1748a108d5f3SDavid S. Miller * Map linear and fragment data from the skb to spd. It reports true if the 17492870c43dSOctavian Purdila * pipe is full or if we already spliced the requested length. 17509c55e01cSJens Axboe */ 1751a108d5f3SDavid S. Miller static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe, 175235f3d14dSJens Axboe unsigned int *offset, unsigned int *len, 175335f3d14dSJens Axboe struct splice_pipe_desc *spd, struct sock *sk) 17542870c43dSOctavian Purdila { 17552870c43dSOctavian Purdila int seg; 17569c55e01cSJens Axboe 17571d0c0b32SEric Dumazet /* map the linear part : 17582996d31fSAlexander Duyck * If skb->head_frag is set, this 'linear' part is backed by a 17592996d31fSAlexander Duyck * fragment, and if the head is not shared with any clones then 17602996d31fSAlexander Duyck * we can avoid a copy since we own the head portion of this page. 17619c55e01cSJens Axboe */ 17622870c43dSOctavian Purdila if (__splice_segment(virt_to_page(skb->data), 17632870c43dSOctavian Purdila (unsigned long) skb->data & (PAGE_SIZE - 1), 17642870c43dSOctavian Purdila skb_headlen(skb), 176518aafc62SEric Dumazet offset, len, spd, 17663a7c1ee4SAlexander Duyck skb_head_is_locked(skb), 17671d0c0b32SEric Dumazet sk, pipe)) 1768a108d5f3SDavid S. Miller return true; 17699c55e01cSJens Axboe 17709c55e01cSJens Axboe /* 17719c55e01cSJens Axboe * then map the fragments 17729c55e01cSJens Axboe */ 17739c55e01cSJens Axboe for (seg = 0; seg < skb_shinfo(skb)->nr_frags; seg++) { 17749c55e01cSJens Axboe const skb_frag_t *f = &skb_shinfo(skb)->frags[seg]; 17759c55e01cSJens Axboe 1776ea2ab693SIan Campbell if (__splice_segment(skb_frag_page(f), 17779e903e08SEric Dumazet f->page_offset, skb_frag_size(f), 177818aafc62SEric Dumazet offset, len, spd, false, sk, pipe)) 1779a108d5f3SDavid S. Miller return true; 17809c55e01cSJens Axboe } 17819c55e01cSJens Axboe 1782a108d5f3SDavid S. Miller return false; 17839c55e01cSJens Axboe } 17849c55e01cSJens Axboe 17859c55e01cSJens Axboe /* 17869c55e01cSJens Axboe * Map data from the skb to a pipe. Should handle both the linear part, 17879c55e01cSJens Axboe * the fragments, and the frag list. It does NOT handle frag lists within 17889c55e01cSJens Axboe * the frag list, if such a thing exists. We'd probably need to recurse to 17899c55e01cSJens Axboe * handle that cleanly. 17909c55e01cSJens Axboe */ 17918b9d3728SJarek Poplawski int skb_splice_bits(struct sk_buff *skb, unsigned int offset, 17929c55e01cSJens Axboe struct pipe_inode_info *pipe, unsigned int tlen, 17939c55e01cSJens Axboe unsigned int flags) 17949c55e01cSJens Axboe { 179541c73a0dSEric Dumazet struct partial_page partial[MAX_SKB_FRAGS]; 179641c73a0dSEric Dumazet struct page *pages[MAX_SKB_FRAGS]; 17979c55e01cSJens Axboe struct splice_pipe_desc spd = { 17989c55e01cSJens Axboe .pages = pages, 17999c55e01cSJens Axboe .partial = partial, 1800047fe360SEric Dumazet .nr_pages_max = MAX_SKB_FRAGS, 18019c55e01cSJens Axboe .flags = flags, 18029c55e01cSJens Axboe .ops = &sock_pipe_buf_ops, 18039c55e01cSJens Axboe .spd_release = sock_spd_release, 18049c55e01cSJens Axboe }; 1805fbb398a8SDavid S. Miller struct sk_buff *frag_iter; 18067a67e56fSJarek Poplawski struct sock *sk = skb->sk; 180735f3d14dSJens Axboe int ret = 0; 180835f3d14dSJens Axboe 18099c55e01cSJens Axboe /* 18109c55e01cSJens Axboe * __skb_splice_bits() only fails if the output has no room left, 18119c55e01cSJens Axboe * so no point in going over the frag_list for the error case. 18129c55e01cSJens Axboe */ 181335f3d14dSJens Axboe if (__skb_splice_bits(skb, pipe, &offset, &tlen, &spd, sk)) 18149c55e01cSJens Axboe goto done; 18159c55e01cSJens Axboe else if (!tlen) 18169c55e01cSJens Axboe goto done; 18179c55e01cSJens Axboe 18189c55e01cSJens Axboe /* 18199c55e01cSJens Axboe * now see if we have a frag_list to map 18209c55e01cSJens Axboe */ 1821fbb398a8SDavid S. Miller skb_walk_frags(skb, frag_iter) { 1822fbb398a8SDavid S. Miller if (!tlen) 18239c55e01cSJens Axboe break; 182435f3d14dSJens Axboe if (__skb_splice_bits(frag_iter, pipe, &offset, &tlen, &spd, sk)) 1825fbb398a8SDavid S. Miller break; 18269c55e01cSJens Axboe } 18279c55e01cSJens Axboe 18289c55e01cSJens Axboe done: 18299c55e01cSJens Axboe if (spd.nr_pages) { 18309c55e01cSJens Axboe /* 18319c55e01cSJens Axboe * Drop the socket lock, otherwise we have reverse 18329c55e01cSJens Axboe * locking dependencies between sk_lock and i_mutex 18339c55e01cSJens Axboe * here as compared to sendfile(). We enter here 18349c55e01cSJens Axboe * with the socket lock held, and splice_to_pipe() will 18359c55e01cSJens Axboe * grab the pipe inode lock. For sendfile() emulation, 18369c55e01cSJens Axboe * we call into ->sendpage() with the i_mutex lock held 18379c55e01cSJens Axboe * and networking will grab the socket lock. 18389c55e01cSJens Axboe */ 1839293ad604SOctavian Purdila release_sock(sk); 18409c55e01cSJens Axboe ret = splice_to_pipe(pipe, &spd); 1841293ad604SOctavian Purdila lock_sock(sk); 18429c55e01cSJens Axboe } 18439c55e01cSJens Axboe 184435f3d14dSJens Axboe return ret; 18459c55e01cSJens Axboe } 18469c55e01cSJens Axboe 1847357b40a1SHerbert Xu /** 1848357b40a1SHerbert Xu * skb_store_bits - store bits from kernel buffer to skb 1849357b40a1SHerbert Xu * @skb: destination buffer 1850357b40a1SHerbert Xu * @offset: offset in destination 1851357b40a1SHerbert Xu * @from: source buffer 1852357b40a1SHerbert Xu * @len: number of bytes to copy 1853357b40a1SHerbert Xu * 1854357b40a1SHerbert Xu * Copy the specified number of bytes from the source buffer to the 1855357b40a1SHerbert Xu * destination skb. This function handles all the messy bits of 1856357b40a1SHerbert Xu * traversing fragment lists and such. 1857357b40a1SHerbert Xu */ 1858357b40a1SHerbert Xu 18590c6fcc8aSStephen Hemminger int skb_store_bits(struct sk_buff *skb, int offset, const void *from, int len) 1860357b40a1SHerbert Xu { 18611a028e50SDavid S. Miller int start = skb_headlen(skb); 1862fbb398a8SDavid S. Miller struct sk_buff *frag_iter; 1863fbb398a8SDavid S. Miller int i, copy; 1864357b40a1SHerbert Xu 1865357b40a1SHerbert Xu if (offset > (int)skb->len - len) 1866357b40a1SHerbert Xu goto fault; 1867357b40a1SHerbert Xu 18681a028e50SDavid S. Miller if ((copy = start - offset) > 0) { 1869357b40a1SHerbert Xu if (copy > len) 1870357b40a1SHerbert Xu copy = len; 187127d7ff46SArnaldo Carvalho de Melo skb_copy_to_linear_data_offset(skb, offset, from, copy); 1872357b40a1SHerbert Xu if ((len -= copy) == 0) 1873357b40a1SHerbert Xu return 0; 1874357b40a1SHerbert Xu offset += copy; 1875357b40a1SHerbert Xu from += copy; 1876357b40a1SHerbert Xu } 1877357b40a1SHerbert Xu 1878357b40a1SHerbert Xu for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 1879357b40a1SHerbert Xu skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 18801a028e50SDavid S. Miller int end; 1881357b40a1SHerbert Xu 1882547b792cSIlpo Järvinen WARN_ON(start > offset + len); 18831a028e50SDavid S. Miller 18849e903e08SEric Dumazet end = start + skb_frag_size(frag); 1885357b40a1SHerbert Xu if ((copy = end - offset) > 0) { 1886357b40a1SHerbert Xu u8 *vaddr; 1887357b40a1SHerbert Xu 1888357b40a1SHerbert Xu if (copy > len) 1889357b40a1SHerbert Xu copy = len; 1890357b40a1SHerbert Xu 189151c56b00SEric Dumazet vaddr = kmap_atomic(skb_frag_page(frag)); 18921a028e50SDavid S. Miller memcpy(vaddr + frag->page_offset + offset - start, 18931a028e50SDavid S. Miller from, copy); 189451c56b00SEric Dumazet kunmap_atomic(vaddr); 1895357b40a1SHerbert Xu 1896357b40a1SHerbert Xu if ((len -= copy) == 0) 1897357b40a1SHerbert Xu return 0; 1898357b40a1SHerbert Xu offset += copy; 1899357b40a1SHerbert Xu from += copy; 1900357b40a1SHerbert Xu } 19011a028e50SDavid S. Miller start = end; 1902357b40a1SHerbert Xu } 1903357b40a1SHerbert Xu 1904fbb398a8SDavid S. Miller skb_walk_frags(skb, frag_iter) { 19051a028e50SDavid S. Miller int end; 1906357b40a1SHerbert Xu 1907547b792cSIlpo Järvinen WARN_ON(start > offset + len); 19081a028e50SDavid S. Miller 1909fbb398a8SDavid S. Miller end = start + frag_iter->len; 1910357b40a1SHerbert Xu if ((copy = end - offset) > 0) { 1911357b40a1SHerbert Xu if (copy > len) 1912357b40a1SHerbert Xu copy = len; 1913fbb398a8SDavid S. Miller if (skb_store_bits(frag_iter, offset - start, 19141a028e50SDavid S. Miller from, copy)) 1915357b40a1SHerbert Xu goto fault; 1916357b40a1SHerbert Xu if ((len -= copy) == 0) 1917357b40a1SHerbert Xu return 0; 1918357b40a1SHerbert Xu offset += copy; 1919357b40a1SHerbert Xu from += copy; 1920357b40a1SHerbert Xu } 19211a028e50SDavid S. Miller start = end; 1922357b40a1SHerbert Xu } 1923357b40a1SHerbert Xu if (!len) 1924357b40a1SHerbert Xu return 0; 1925357b40a1SHerbert Xu 1926357b40a1SHerbert Xu fault: 1927357b40a1SHerbert Xu return -EFAULT; 1928357b40a1SHerbert Xu } 1929357b40a1SHerbert Xu EXPORT_SYMBOL(skb_store_bits); 1930357b40a1SHerbert Xu 19311da177e4SLinus Torvalds /* Checksum skb data. */ 19321da177e4SLinus Torvalds 19332bbbc868SAl Viro __wsum skb_checksum(const struct sk_buff *skb, int offset, 19342bbbc868SAl Viro int len, __wsum csum) 19351da177e4SLinus Torvalds { 19361a028e50SDavid S. Miller int start = skb_headlen(skb); 19371a028e50SDavid S. Miller int i, copy = start - offset; 1938fbb398a8SDavid S. Miller struct sk_buff *frag_iter; 19391da177e4SLinus Torvalds int pos = 0; 19401da177e4SLinus Torvalds 19411da177e4SLinus Torvalds /* Checksum header. */ 19421da177e4SLinus Torvalds if (copy > 0) { 19431da177e4SLinus Torvalds if (copy > len) 19441da177e4SLinus Torvalds copy = len; 19451da177e4SLinus Torvalds csum = csum_partial(skb->data + offset, copy, csum); 19461da177e4SLinus Torvalds if ((len -= copy) == 0) 19471da177e4SLinus Torvalds return csum; 19481da177e4SLinus Torvalds offset += copy; 19491da177e4SLinus Torvalds pos = copy; 19501da177e4SLinus Torvalds } 19511da177e4SLinus Torvalds 19521da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 19531a028e50SDavid S. Miller int end; 195451c56b00SEric Dumazet skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 19551da177e4SLinus Torvalds 1956547b792cSIlpo Järvinen WARN_ON(start > offset + len); 19571a028e50SDavid S. Miller 195851c56b00SEric Dumazet end = start + skb_frag_size(frag); 19591da177e4SLinus Torvalds if ((copy = end - offset) > 0) { 196044bb9363SAl Viro __wsum csum2; 19611da177e4SLinus Torvalds u8 *vaddr; 19621da177e4SLinus Torvalds 19631da177e4SLinus Torvalds if (copy > len) 19641da177e4SLinus Torvalds copy = len; 196551c56b00SEric Dumazet vaddr = kmap_atomic(skb_frag_page(frag)); 19661a028e50SDavid S. Miller csum2 = csum_partial(vaddr + frag->page_offset + 19671a028e50SDavid S. Miller offset - start, copy, 0); 196851c56b00SEric Dumazet kunmap_atomic(vaddr); 19691da177e4SLinus Torvalds csum = csum_block_add(csum, csum2, pos); 19701da177e4SLinus Torvalds if (!(len -= copy)) 19711da177e4SLinus Torvalds return csum; 19721da177e4SLinus Torvalds offset += copy; 19731da177e4SLinus Torvalds pos += copy; 19741da177e4SLinus Torvalds } 19751a028e50SDavid S. Miller start = end; 19761da177e4SLinus Torvalds } 19771da177e4SLinus Torvalds 1978fbb398a8SDavid S. Miller skb_walk_frags(skb, frag_iter) { 19791a028e50SDavid S. Miller int end; 19801da177e4SLinus Torvalds 1981547b792cSIlpo Järvinen WARN_ON(start > offset + len); 19821a028e50SDavid S. Miller 1983fbb398a8SDavid S. Miller end = start + frag_iter->len; 19841da177e4SLinus Torvalds if ((copy = end - offset) > 0) { 19855f92a738SAl Viro __wsum csum2; 19861da177e4SLinus Torvalds if (copy > len) 19871da177e4SLinus Torvalds copy = len; 1988fbb398a8SDavid S. Miller csum2 = skb_checksum(frag_iter, offset - start, 19891a028e50SDavid S. Miller copy, 0); 19901da177e4SLinus Torvalds csum = csum_block_add(csum, csum2, pos); 19911da177e4SLinus Torvalds if ((len -= copy) == 0) 19921da177e4SLinus Torvalds return csum; 19931da177e4SLinus Torvalds offset += copy; 19941da177e4SLinus Torvalds pos += copy; 19951da177e4SLinus Torvalds } 19961a028e50SDavid S. Miller start = end; 19971da177e4SLinus Torvalds } 199809a62660SKris Katterjohn BUG_ON(len); 19991da177e4SLinus Torvalds 20001da177e4SLinus Torvalds return csum; 20011da177e4SLinus Torvalds } 2002b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_checksum); 20031da177e4SLinus Torvalds 20041da177e4SLinus Torvalds /* Both of above in one bottle. */ 20051da177e4SLinus Torvalds 200681d77662SAl Viro __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, 200781d77662SAl Viro u8 *to, int len, __wsum csum) 20081da177e4SLinus Torvalds { 20091a028e50SDavid S. Miller int start = skb_headlen(skb); 20101a028e50SDavid S. Miller int i, copy = start - offset; 2011fbb398a8SDavid S. Miller struct sk_buff *frag_iter; 20121da177e4SLinus Torvalds int pos = 0; 20131da177e4SLinus Torvalds 20141da177e4SLinus Torvalds /* Copy header. */ 20151da177e4SLinus Torvalds if (copy > 0) { 20161da177e4SLinus Torvalds if (copy > len) 20171da177e4SLinus Torvalds copy = len; 20181da177e4SLinus Torvalds csum = csum_partial_copy_nocheck(skb->data + offset, to, 20191da177e4SLinus Torvalds copy, csum); 20201da177e4SLinus Torvalds if ((len -= copy) == 0) 20211da177e4SLinus Torvalds return csum; 20221da177e4SLinus Torvalds offset += copy; 20231da177e4SLinus Torvalds to += copy; 20241da177e4SLinus Torvalds pos = copy; 20251da177e4SLinus Torvalds } 20261da177e4SLinus Torvalds 20271da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 20281a028e50SDavid S. Miller int end; 20291da177e4SLinus Torvalds 2030547b792cSIlpo Järvinen WARN_ON(start > offset + len); 20311a028e50SDavid S. Miller 20329e903e08SEric Dumazet end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]); 20331da177e4SLinus Torvalds if ((copy = end - offset) > 0) { 20345084205fSAl Viro __wsum csum2; 20351da177e4SLinus Torvalds u8 *vaddr; 20361da177e4SLinus Torvalds skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 20371da177e4SLinus Torvalds 20381da177e4SLinus Torvalds if (copy > len) 20391da177e4SLinus Torvalds copy = len; 204051c56b00SEric Dumazet vaddr = kmap_atomic(skb_frag_page(frag)); 20411da177e4SLinus Torvalds csum2 = csum_partial_copy_nocheck(vaddr + 20421a028e50SDavid S. Miller frag->page_offset + 20431a028e50SDavid S. Miller offset - start, to, 20441a028e50SDavid S. Miller copy, 0); 204551c56b00SEric Dumazet kunmap_atomic(vaddr); 20461da177e4SLinus Torvalds csum = csum_block_add(csum, csum2, pos); 20471da177e4SLinus Torvalds if (!(len -= copy)) 20481da177e4SLinus Torvalds return csum; 20491da177e4SLinus Torvalds offset += copy; 20501da177e4SLinus Torvalds to += copy; 20511da177e4SLinus Torvalds pos += copy; 20521da177e4SLinus Torvalds } 20531a028e50SDavid S. Miller start = end; 20541da177e4SLinus Torvalds } 20551da177e4SLinus Torvalds 2056fbb398a8SDavid S. Miller skb_walk_frags(skb, frag_iter) { 205781d77662SAl Viro __wsum csum2; 20581a028e50SDavid S. Miller int end; 20591da177e4SLinus Torvalds 2060547b792cSIlpo Järvinen WARN_ON(start > offset + len); 20611a028e50SDavid S. Miller 2062fbb398a8SDavid S. Miller end = start + frag_iter->len; 20631da177e4SLinus Torvalds if ((copy = end - offset) > 0) { 20641da177e4SLinus Torvalds if (copy > len) 20651da177e4SLinus Torvalds copy = len; 2066fbb398a8SDavid S. Miller csum2 = skb_copy_and_csum_bits(frag_iter, 20671a028e50SDavid S. Miller offset - start, 20681da177e4SLinus Torvalds to, copy, 0); 20691da177e4SLinus Torvalds csum = csum_block_add(csum, csum2, pos); 20701da177e4SLinus Torvalds if ((len -= copy) == 0) 20711da177e4SLinus Torvalds return csum; 20721da177e4SLinus Torvalds offset += copy; 20731da177e4SLinus Torvalds to += copy; 20741da177e4SLinus Torvalds pos += copy; 20751da177e4SLinus Torvalds } 20761a028e50SDavid S. Miller start = end; 20771da177e4SLinus Torvalds } 207809a62660SKris Katterjohn BUG_ON(len); 20791da177e4SLinus Torvalds return csum; 20801da177e4SLinus Torvalds } 2081b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_copy_and_csum_bits); 20821da177e4SLinus Torvalds 20831da177e4SLinus Torvalds void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to) 20841da177e4SLinus Torvalds { 2085d3bc23e7SAl Viro __wsum csum; 20861da177e4SLinus Torvalds long csstart; 20871da177e4SLinus Torvalds 208884fa7933SPatrick McHardy if (skb->ip_summed == CHECKSUM_PARTIAL) 208955508d60SMichał Mirosław csstart = skb_checksum_start_offset(skb); 20901da177e4SLinus Torvalds else 20911da177e4SLinus Torvalds csstart = skb_headlen(skb); 20921da177e4SLinus Torvalds 209309a62660SKris Katterjohn BUG_ON(csstart > skb_headlen(skb)); 20941da177e4SLinus Torvalds 2095d626f62bSArnaldo Carvalho de Melo skb_copy_from_linear_data(skb, to, csstart); 20961da177e4SLinus Torvalds 20971da177e4SLinus Torvalds csum = 0; 20981da177e4SLinus Torvalds if (csstart != skb->len) 20991da177e4SLinus Torvalds csum = skb_copy_and_csum_bits(skb, csstart, to + csstart, 21001da177e4SLinus Torvalds skb->len - csstart, 0); 21011da177e4SLinus Torvalds 210284fa7933SPatrick McHardy if (skb->ip_summed == CHECKSUM_PARTIAL) { 2103ff1dcadbSAl Viro long csstuff = csstart + skb->csum_offset; 21041da177e4SLinus Torvalds 2105d3bc23e7SAl Viro *((__sum16 *)(to + csstuff)) = csum_fold(csum); 21061da177e4SLinus Torvalds } 21071da177e4SLinus Torvalds } 2108b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_copy_and_csum_dev); 21091da177e4SLinus Torvalds 21101da177e4SLinus Torvalds /** 21111da177e4SLinus Torvalds * skb_dequeue - remove from the head of the queue 21121da177e4SLinus Torvalds * @list: list to dequeue from 21131da177e4SLinus Torvalds * 21141da177e4SLinus Torvalds * Remove the head of the list. The list lock is taken so the function 21151da177e4SLinus Torvalds * may be used safely with other locking list functions. The head item is 21161da177e4SLinus Torvalds * returned or %NULL if the list is empty. 21171da177e4SLinus Torvalds */ 21181da177e4SLinus Torvalds 21191da177e4SLinus Torvalds struct sk_buff *skb_dequeue(struct sk_buff_head *list) 21201da177e4SLinus Torvalds { 21211da177e4SLinus Torvalds unsigned long flags; 21221da177e4SLinus Torvalds struct sk_buff *result; 21231da177e4SLinus Torvalds 21241da177e4SLinus Torvalds spin_lock_irqsave(&list->lock, flags); 21251da177e4SLinus Torvalds result = __skb_dequeue(list); 21261da177e4SLinus Torvalds spin_unlock_irqrestore(&list->lock, flags); 21271da177e4SLinus Torvalds return result; 21281da177e4SLinus Torvalds } 2129b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_dequeue); 21301da177e4SLinus Torvalds 21311da177e4SLinus Torvalds /** 21321da177e4SLinus Torvalds * skb_dequeue_tail - remove from the tail of the queue 21331da177e4SLinus Torvalds * @list: list to dequeue from 21341da177e4SLinus Torvalds * 21351da177e4SLinus Torvalds * Remove the tail of the list. The list lock is taken so the function 21361da177e4SLinus Torvalds * may be used safely with other locking list functions. The tail item is 21371da177e4SLinus Torvalds * returned or %NULL if the list is empty. 21381da177e4SLinus Torvalds */ 21391da177e4SLinus Torvalds struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list) 21401da177e4SLinus Torvalds { 21411da177e4SLinus Torvalds unsigned long flags; 21421da177e4SLinus Torvalds struct sk_buff *result; 21431da177e4SLinus Torvalds 21441da177e4SLinus Torvalds spin_lock_irqsave(&list->lock, flags); 21451da177e4SLinus Torvalds result = __skb_dequeue_tail(list); 21461da177e4SLinus Torvalds spin_unlock_irqrestore(&list->lock, flags); 21471da177e4SLinus Torvalds return result; 21481da177e4SLinus Torvalds } 2149b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_dequeue_tail); 21501da177e4SLinus Torvalds 21511da177e4SLinus Torvalds /** 21521da177e4SLinus Torvalds * skb_queue_purge - empty a list 21531da177e4SLinus Torvalds * @list: list to empty 21541da177e4SLinus Torvalds * 21551da177e4SLinus Torvalds * Delete all buffers on an &sk_buff list. Each buffer is removed from 21561da177e4SLinus Torvalds * the list and one reference dropped. This function takes the list 21571da177e4SLinus Torvalds * lock and is atomic with respect to other list locking functions. 21581da177e4SLinus Torvalds */ 21591da177e4SLinus Torvalds void skb_queue_purge(struct sk_buff_head *list) 21601da177e4SLinus Torvalds { 21611da177e4SLinus Torvalds struct sk_buff *skb; 21621da177e4SLinus Torvalds while ((skb = skb_dequeue(list)) != NULL) 21631da177e4SLinus Torvalds kfree_skb(skb); 21641da177e4SLinus Torvalds } 2165b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_queue_purge); 21661da177e4SLinus Torvalds 21671da177e4SLinus Torvalds /** 21681da177e4SLinus Torvalds * skb_queue_head - queue a buffer at the list head 21691da177e4SLinus Torvalds * @list: list to use 21701da177e4SLinus Torvalds * @newsk: buffer to queue 21711da177e4SLinus Torvalds * 21721da177e4SLinus Torvalds * Queue a buffer at the start of the list. This function takes the 21731da177e4SLinus Torvalds * list lock and can be used safely with other locking &sk_buff functions 21741da177e4SLinus Torvalds * safely. 21751da177e4SLinus Torvalds * 21761da177e4SLinus Torvalds * A buffer cannot be placed on two lists at the same time. 21771da177e4SLinus Torvalds */ 21781da177e4SLinus Torvalds void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk) 21791da177e4SLinus Torvalds { 21801da177e4SLinus Torvalds unsigned long flags; 21811da177e4SLinus Torvalds 21821da177e4SLinus Torvalds spin_lock_irqsave(&list->lock, flags); 21831da177e4SLinus Torvalds __skb_queue_head(list, newsk); 21841da177e4SLinus Torvalds spin_unlock_irqrestore(&list->lock, flags); 21851da177e4SLinus Torvalds } 2186b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_queue_head); 21871da177e4SLinus Torvalds 21881da177e4SLinus Torvalds /** 21891da177e4SLinus Torvalds * skb_queue_tail - queue a buffer at the list tail 21901da177e4SLinus Torvalds * @list: list to use 21911da177e4SLinus Torvalds * @newsk: buffer to queue 21921da177e4SLinus Torvalds * 21931da177e4SLinus Torvalds * Queue a buffer at the tail of the list. This function takes the 21941da177e4SLinus Torvalds * list lock and can be used safely with other locking &sk_buff functions 21951da177e4SLinus Torvalds * safely. 21961da177e4SLinus Torvalds * 21971da177e4SLinus Torvalds * A buffer cannot be placed on two lists at the same time. 21981da177e4SLinus Torvalds */ 21991da177e4SLinus Torvalds void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk) 22001da177e4SLinus Torvalds { 22011da177e4SLinus Torvalds unsigned long flags; 22021da177e4SLinus Torvalds 22031da177e4SLinus Torvalds spin_lock_irqsave(&list->lock, flags); 22041da177e4SLinus Torvalds __skb_queue_tail(list, newsk); 22051da177e4SLinus Torvalds spin_unlock_irqrestore(&list->lock, flags); 22061da177e4SLinus Torvalds } 2207b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_queue_tail); 22088728b834SDavid S. Miller 22091da177e4SLinus Torvalds /** 22101da177e4SLinus Torvalds * skb_unlink - remove a buffer from a list 22111da177e4SLinus Torvalds * @skb: buffer to remove 22128728b834SDavid S. Miller * @list: list to use 22131da177e4SLinus Torvalds * 22148728b834SDavid S. Miller * Remove a packet from a list. The list locks are taken and this 22158728b834SDavid S. Miller * function is atomic with respect to other list locked calls 22161da177e4SLinus Torvalds * 22178728b834SDavid S. Miller * You must know what list the SKB is on. 22181da177e4SLinus Torvalds */ 22198728b834SDavid S. Miller void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) 22201da177e4SLinus Torvalds { 22211da177e4SLinus Torvalds unsigned long flags; 22221da177e4SLinus Torvalds 22231da177e4SLinus Torvalds spin_lock_irqsave(&list->lock, flags); 22248728b834SDavid S. Miller __skb_unlink(skb, list); 22251da177e4SLinus Torvalds spin_unlock_irqrestore(&list->lock, flags); 22261da177e4SLinus Torvalds } 2227b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_unlink); 22281da177e4SLinus Torvalds 22291da177e4SLinus Torvalds /** 22301da177e4SLinus Torvalds * skb_append - append a buffer 22311da177e4SLinus Torvalds * @old: buffer to insert after 22321da177e4SLinus Torvalds * @newsk: buffer to insert 22338728b834SDavid S. Miller * @list: list to use 22341da177e4SLinus Torvalds * 22351da177e4SLinus Torvalds * Place a packet after a given packet in a list. The list locks are taken 22361da177e4SLinus Torvalds * and this function is atomic with respect to other list locked calls. 22371da177e4SLinus Torvalds * A buffer cannot be placed on two lists at the same time. 22381da177e4SLinus Torvalds */ 22398728b834SDavid S. Miller void skb_append(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list) 22401da177e4SLinus Torvalds { 22411da177e4SLinus Torvalds unsigned long flags; 22421da177e4SLinus Torvalds 22438728b834SDavid S. Miller spin_lock_irqsave(&list->lock, flags); 22447de6c033SGerrit Renker __skb_queue_after(list, old, newsk); 22458728b834SDavid S. Miller spin_unlock_irqrestore(&list->lock, flags); 22461da177e4SLinus Torvalds } 2247b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_append); 22481da177e4SLinus Torvalds 22491da177e4SLinus Torvalds /** 22501da177e4SLinus Torvalds * skb_insert - insert a buffer 22511da177e4SLinus Torvalds * @old: buffer to insert before 22521da177e4SLinus Torvalds * @newsk: buffer to insert 22538728b834SDavid S. Miller * @list: list to use 22541da177e4SLinus Torvalds * 22558728b834SDavid S. Miller * Place a packet before a given packet in a list. The list locks are 22568728b834SDavid S. Miller * taken and this function is atomic with respect to other list locked 22578728b834SDavid S. Miller * calls. 22588728b834SDavid S. Miller * 22591da177e4SLinus Torvalds * A buffer cannot be placed on two lists at the same time. 22601da177e4SLinus Torvalds */ 22618728b834SDavid S. Miller void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list) 22621da177e4SLinus Torvalds { 22631da177e4SLinus Torvalds unsigned long flags; 22641da177e4SLinus Torvalds 22658728b834SDavid S. Miller spin_lock_irqsave(&list->lock, flags); 22668728b834SDavid S. Miller __skb_insert(newsk, old->prev, old, list); 22678728b834SDavid S. Miller spin_unlock_irqrestore(&list->lock, flags); 22681da177e4SLinus Torvalds } 2269b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_insert); 22701da177e4SLinus Torvalds 22711da177e4SLinus Torvalds static inline void skb_split_inside_header(struct sk_buff *skb, 22721da177e4SLinus Torvalds struct sk_buff* skb1, 22731da177e4SLinus Torvalds const u32 len, const int pos) 22741da177e4SLinus Torvalds { 22751da177e4SLinus Torvalds int i; 22761da177e4SLinus Torvalds 2277d626f62bSArnaldo Carvalho de Melo skb_copy_from_linear_data_offset(skb, len, skb_put(skb1, pos - len), 2278d626f62bSArnaldo Carvalho de Melo pos - len); 22791da177e4SLinus Torvalds /* And move data appendix as is. */ 22801da177e4SLinus Torvalds for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) 22811da177e4SLinus Torvalds skb_shinfo(skb1)->frags[i] = skb_shinfo(skb)->frags[i]; 22821da177e4SLinus Torvalds 22831da177e4SLinus Torvalds skb_shinfo(skb1)->nr_frags = skb_shinfo(skb)->nr_frags; 22841da177e4SLinus Torvalds skb_shinfo(skb)->nr_frags = 0; 22851da177e4SLinus Torvalds skb1->data_len = skb->data_len; 22861da177e4SLinus Torvalds skb1->len += skb1->data_len; 22871da177e4SLinus Torvalds skb->data_len = 0; 22881da177e4SLinus Torvalds skb->len = len; 228927a884dcSArnaldo Carvalho de Melo skb_set_tail_pointer(skb, len); 22901da177e4SLinus Torvalds } 22911da177e4SLinus Torvalds 22921da177e4SLinus Torvalds static inline void skb_split_no_header(struct sk_buff *skb, 22931da177e4SLinus Torvalds struct sk_buff* skb1, 22941da177e4SLinus Torvalds const u32 len, int pos) 22951da177e4SLinus Torvalds { 22961da177e4SLinus Torvalds int i, k = 0; 22971da177e4SLinus Torvalds const int nfrags = skb_shinfo(skb)->nr_frags; 22981da177e4SLinus Torvalds 22991da177e4SLinus Torvalds skb_shinfo(skb)->nr_frags = 0; 23001da177e4SLinus Torvalds skb1->len = skb1->data_len = skb->len - len; 23011da177e4SLinus Torvalds skb->len = len; 23021da177e4SLinus Torvalds skb->data_len = len - pos; 23031da177e4SLinus Torvalds 23041da177e4SLinus Torvalds for (i = 0; i < nfrags; i++) { 23059e903e08SEric Dumazet int size = skb_frag_size(&skb_shinfo(skb)->frags[i]); 23061da177e4SLinus Torvalds 23071da177e4SLinus Torvalds if (pos + size > len) { 23081da177e4SLinus Torvalds skb_shinfo(skb1)->frags[k] = skb_shinfo(skb)->frags[i]; 23091da177e4SLinus Torvalds 23101da177e4SLinus Torvalds if (pos < len) { 23111da177e4SLinus Torvalds /* Split frag. 23121da177e4SLinus Torvalds * We have two variants in this case: 23131da177e4SLinus Torvalds * 1. Move all the frag to the second 23141da177e4SLinus Torvalds * part, if it is possible. F.e. 23151da177e4SLinus Torvalds * this approach is mandatory for TUX, 23161da177e4SLinus Torvalds * where splitting is expensive. 23171da177e4SLinus Torvalds * 2. Split is accurately. We make this. 23181da177e4SLinus Torvalds */ 2319ea2ab693SIan Campbell skb_frag_ref(skb, i); 23201da177e4SLinus Torvalds skb_shinfo(skb1)->frags[0].page_offset += len - pos; 23219e903e08SEric Dumazet skb_frag_size_sub(&skb_shinfo(skb1)->frags[0], len - pos); 23229e903e08SEric Dumazet skb_frag_size_set(&skb_shinfo(skb)->frags[i], len - pos); 23231da177e4SLinus Torvalds skb_shinfo(skb)->nr_frags++; 23241da177e4SLinus Torvalds } 23251da177e4SLinus Torvalds k++; 23261da177e4SLinus Torvalds } else 23271da177e4SLinus Torvalds skb_shinfo(skb)->nr_frags++; 23281da177e4SLinus Torvalds pos += size; 23291da177e4SLinus Torvalds } 23301da177e4SLinus Torvalds skb_shinfo(skb1)->nr_frags = k; 23311da177e4SLinus Torvalds } 23321da177e4SLinus Torvalds 23331da177e4SLinus Torvalds /** 23341da177e4SLinus Torvalds * skb_split - Split fragmented skb to two parts at length len. 23351da177e4SLinus Torvalds * @skb: the buffer to split 23361da177e4SLinus Torvalds * @skb1: the buffer to receive the second part 23371da177e4SLinus Torvalds * @len: new length for skb 23381da177e4SLinus Torvalds */ 23391da177e4SLinus Torvalds void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len) 23401da177e4SLinus Torvalds { 23411da177e4SLinus Torvalds int pos = skb_headlen(skb); 23421da177e4SLinus Torvalds 23431da177e4SLinus Torvalds if (len < pos) /* Split line is inside header. */ 23441da177e4SLinus Torvalds skb_split_inside_header(skb, skb1, len, pos); 23451da177e4SLinus Torvalds else /* Second chunk has no header, nothing to copy. */ 23461da177e4SLinus Torvalds skb_split_no_header(skb, skb1, len, pos); 23471da177e4SLinus Torvalds } 2348b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_split); 23491da177e4SLinus Torvalds 23509f782db3SIlpo Järvinen /* Shifting from/to a cloned skb is a no-go. 23519f782db3SIlpo Järvinen * 23529f782db3SIlpo Järvinen * Caller cannot keep skb_shinfo related pointers past calling here! 23539f782db3SIlpo Järvinen */ 2354832d11c5SIlpo Järvinen static int skb_prepare_for_shift(struct sk_buff *skb) 2355832d11c5SIlpo Järvinen { 23560ace2856SIlpo Järvinen return skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC); 2357832d11c5SIlpo Järvinen } 2358832d11c5SIlpo Järvinen 2359832d11c5SIlpo Järvinen /** 2360832d11c5SIlpo Järvinen * skb_shift - Shifts paged data partially from skb to another 2361832d11c5SIlpo Järvinen * @tgt: buffer into which tail data gets added 2362832d11c5SIlpo Järvinen * @skb: buffer from which the paged data comes from 2363832d11c5SIlpo Järvinen * @shiftlen: shift up to this many bytes 2364832d11c5SIlpo Järvinen * 2365832d11c5SIlpo Järvinen * Attempts to shift up to shiftlen worth of bytes, which may be less than 236620e994a0SFeng King * the length of the skb, from skb to tgt. Returns number bytes shifted. 2367832d11c5SIlpo Järvinen * It's up to caller to free skb if everything was shifted. 2368832d11c5SIlpo Järvinen * 2369832d11c5SIlpo Järvinen * If @tgt runs out of frags, the whole operation is aborted. 2370832d11c5SIlpo Järvinen * 2371832d11c5SIlpo Järvinen * Skb cannot include anything else but paged data while tgt is allowed 2372832d11c5SIlpo Järvinen * to have non-paged data as well. 2373832d11c5SIlpo Järvinen * 2374832d11c5SIlpo Järvinen * TODO: full sized shift could be optimized but that would need 2375832d11c5SIlpo Järvinen * specialized skb free'er to handle frags without up-to-date nr_frags. 2376832d11c5SIlpo Järvinen */ 2377832d11c5SIlpo Järvinen int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen) 2378832d11c5SIlpo Järvinen { 2379832d11c5SIlpo Järvinen int from, to, merge, todo; 2380832d11c5SIlpo Järvinen struct skb_frag_struct *fragfrom, *fragto; 2381832d11c5SIlpo Järvinen 2382832d11c5SIlpo Järvinen BUG_ON(shiftlen > skb->len); 2383832d11c5SIlpo Järvinen BUG_ON(skb_headlen(skb)); /* Would corrupt stream */ 2384832d11c5SIlpo Järvinen 2385832d11c5SIlpo Järvinen todo = shiftlen; 2386832d11c5SIlpo Järvinen from = 0; 2387832d11c5SIlpo Järvinen to = skb_shinfo(tgt)->nr_frags; 2388832d11c5SIlpo Järvinen fragfrom = &skb_shinfo(skb)->frags[from]; 2389832d11c5SIlpo Järvinen 2390832d11c5SIlpo Järvinen /* Actual merge is delayed until the point when we know we can 2391832d11c5SIlpo Järvinen * commit all, so that we don't have to undo partial changes 2392832d11c5SIlpo Järvinen */ 2393832d11c5SIlpo Järvinen if (!to || 2394ea2ab693SIan Campbell !skb_can_coalesce(tgt, to, skb_frag_page(fragfrom), 2395ea2ab693SIan Campbell fragfrom->page_offset)) { 2396832d11c5SIlpo Järvinen merge = -1; 2397832d11c5SIlpo Järvinen } else { 2398832d11c5SIlpo Järvinen merge = to - 1; 2399832d11c5SIlpo Järvinen 24009e903e08SEric Dumazet todo -= skb_frag_size(fragfrom); 2401832d11c5SIlpo Järvinen if (todo < 0) { 2402832d11c5SIlpo Järvinen if (skb_prepare_for_shift(skb) || 2403832d11c5SIlpo Järvinen skb_prepare_for_shift(tgt)) 2404832d11c5SIlpo Järvinen return 0; 2405832d11c5SIlpo Järvinen 24069f782db3SIlpo Järvinen /* All previous frag pointers might be stale! */ 24079f782db3SIlpo Järvinen fragfrom = &skb_shinfo(skb)->frags[from]; 2408832d11c5SIlpo Järvinen fragto = &skb_shinfo(tgt)->frags[merge]; 2409832d11c5SIlpo Järvinen 24109e903e08SEric Dumazet skb_frag_size_add(fragto, shiftlen); 24119e903e08SEric Dumazet skb_frag_size_sub(fragfrom, shiftlen); 2412832d11c5SIlpo Järvinen fragfrom->page_offset += shiftlen; 2413832d11c5SIlpo Järvinen 2414832d11c5SIlpo Järvinen goto onlymerged; 2415832d11c5SIlpo Järvinen } 2416832d11c5SIlpo Järvinen 2417832d11c5SIlpo Järvinen from++; 2418832d11c5SIlpo Järvinen } 2419832d11c5SIlpo Järvinen 2420832d11c5SIlpo Järvinen /* Skip full, not-fitting skb to avoid expensive operations */ 2421832d11c5SIlpo Järvinen if ((shiftlen == skb->len) && 2422832d11c5SIlpo Järvinen (skb_shinfo(skb)->nr_frags - from) > (MAX_SKB_FRAGS - to)) 2423832d11c5SIlpo Järvinen return 0; 2424832d11c5SIlpo Järvinen 2425832d11c5SIlpo Järvinen if (skb_prepare_for_shift(skb) || skb_prepare_for_shift(tgt)) 2426832d11c5SIlpo Järvinen return 0; 2427832d11c5SIlpo Järvinen 2428832d11c5SIlpo Järvinen while ((todo > 0) && (from < skb_shinfo(skb)->nr_frags)) { 2429832d11c5SIlpo Järvinen if (to == MAX_SKB_FRAGS) 2430832d11c5SIlpo Järvinen return 0; 2431832d11c5SIlpo Järvinen 2432832d11c5SIlpo Järvinen fragfrom = &skb_shinfo(skb)->frags[from]; 2433832d11c5SIlpo Järvinen fragto = &skb_shinfo(tgt)->frags[to]; 2434832d11c5SIlpo Järvinen 24359e903e08SEric Dumazet if (todo >= skb_frag_size(fragfrom)) { 2436832d11c5SIlpo Järvinen *fragto = *fragfrom; 24379e903e08SEric Dumazet todo -= skb_frag_size(fragfrom); 2438832d11c5SIlpo Järvinen from++; 2439832d11c5SIlpo Järvinen to++; 2440832d11c5SIlpo Järvinen 2441832d11c5SIlpo Järvinen } else { 2442ea2ab693SIan Campbell __skb_frag_ref(fragfrom); 2443832d11c5SIlpo Järvinen fragto->page = fragfrom->page; 2444832d11c5SIlpo Järvinen fragto->page_offset = fragfrom->page_offset; 24459e903e08SEric Dumazet skb_frag_size_set(fragto, todo); 2446832d11c5SIlpo Järvinen 2447832d11c5SIlpo Järvinen fragfrom->page_offset += todo; 24489e903e08SEric Dumazet skb_frag_size_sub(fragfrom, todo); 2449832d11c5SIlpo Järvinen todo = 0; 2450832d11c5SIlpo Järvinen 2451832d11c5SIlpo Järvinen to++; 2452832d11c5SIlpo Järvinen break; 2453832d11c5SIlpo Järvinen } 2454832d11c5SIlpo Järvinen } 2455832d11c5SIlpo Järvinen 2456832d11c5SIlpo Järvinen /* Ready to "commit" this state change to tgt */ 2457832d11c5SIlpo Järvinen skb_shinfo(tgt)->nr_frags = to; 2458832d11c5SIlpo Järvinen 2459832d11c5SIlpo Järvinen if (merge >= 0) { 2460832d11c5SIlpo Järvinen fragfrom = &skb_shinfo(skb)->frags[0]; 2461832d11c5SIlpo Järvinen fragto = &skb_shinfo(tgt)->frags[merge]; 2462832d11c5SIlpo Järvinen 24639e903e08SEric Dumazet skb_frag_size_add(fragto, skb_frag_size(fragfrom)); 2464ea2ab693SIan Campbell __skb_frag_unref(fragfrom); 2465832d11c5SIlpo Järvinen } 2466832d11c5SIlpo Järvinen 2467832d11c5SIlpo Järvinen /* Reposition in the original skb */ 2468832d11c5SIlpo Järvinen to = 0; 2469832d11c5SIlpo Järvinen while (from < skb_shinfo(skb)->nr_frags) 2470832d11c5SIlpo Järvinen skb_shinfo(skb)->frags[to++] = skb_shinfo(skb)->frags[from++]; 2471832d11c5SIlpo Järvinen skb_shinfo(skb)->nr_frags = to; 2472832d11c5SIlpo Järvinen 2473832d11c5SIlpo Järvinen BUG_ON(todo > 0 && !skb_shinfo(skb)->nr_frags); 2474832d11c5SIlpo Järvinen 2475832d11c5SIlpo Järvinen onlymerged: 2476832d11c5SIlpo Järvinen /* Most likely the tgt won't ever need its checksum anymore, skb on 2477832d11c5SIlpo Järvinen * the other hand might need it if it needs to be resent 2478832d11c5SIlpo Järvinen */ 2479832d11c5SIlpo Järvinen tgt->ip_summed = CHECKSUM_PARTIAL; 2480832d11c5SIlpo Järvinen skb->ip_summed = CHECKSUM_PARTIAL; 2481832d11c5SIlpo Järvinen 2482832d11c5SIlpo Järvinen /* Yak, is it really working this way? Some helper please? */ 2483832d11c5SIlpo Järvinen skb->len -= shiftlen; 2484832d11c5SIlpo Järvinen skb->data_len -= shiftlen; 2485832d11c5SIlpo Järvinen skb->truesize -= shiftlen; 2486832d11c5SIlpo Järvinen tgt->len += shiftlen; 2487832d11c5SIlpo Järvinen tgt->data_len += shiftlen; 2488832d11c5SIlpo Järvinen tgt->truesize += shiftlen; 2489832d11c5SIlpo Järvinen 2490832d11c5SIlpo Järvinen return shiftlen; 2491832d11c5SIlpo Järvinen } 2492832d11c5SIlpo Järvinen 2493677e90edSThomas Graf /** 2494677e90edSThomas Graf * skb_prepare_seq_read - Prepare a sequential read of skb data 2495677e90edSThomas Graf * @skb: the buffer to read 2496677e90edSThomas Graf * @from: lower offset of data to be read 2497677e90edSThomas Graf * @to: upper offset of data to be read 2498677e90edSThomas Graf * @st: state variable 2499677e90edSThomas Graf * 2500677e90edSThomas Graf * Initializes the specified state variable. Must be called before 2501677e90edSThomas Graf * invoking skb_seq_read() for the first time. 2502677e90edSThomas Graf */ 2503677e90edSThomas Graf void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, 2504677e90edSThomas Graf unsigned int to, struct skb_seq_state *st) 2505677e90edSThomas Graf { 2506677e90edSThomas Graf st->lower_offset = from; 2507677e90edSThomas Graf st->upper_offset = to; 2508677e90edSThomas Graf st->root_skb = st->cur_skb = skb; 2509677e90edSThomas Graf st->frag_idx = st->stepped_offset = 0; 2510677e90edSThomas Graf st->frag_data = NULL; 2511677e90edSThomas Graf } 2512b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_prepare_seq_read); 2513677e90edSThomas Graf 2514677e90edSThomas Graf /** 2515677e90edSThomas Graf * skb_seq_read - Sequentially read skb data 2516677e90edSThomas Graf * @consumed: number of bytes consumed by the caller so far 2517677e90edSThomas Graf * @data: destination pointer for data to be returned 2518677e90edSThomas Graf * @st: state variable 2519677e90edSThomas Graf * 2520677e90edSThomas Graf * Reads a block of skb data at &consumed relative to the 2521677e90edSThomas Graf * lower offset specified to skb_prepare_seq_read(). Assigns 2522677e90edSThomas Graf * the head of the data block to &data and returns the length 2523677e90edSThomas Graf * of the block or 0 if the end of the skb data or the upper 2524677e90edSThomas Graf * offset has been reached. 2525677e90edSThomas Graf * 2526677e90edSThomas Graf * The caller is not required to consume all of the data 2527677e90edSThomas Graf * returned, i.e. &consumed is typically set to the number 2528677e90edSThomas Graf * of bytes already consumed and the next call to 2529677e90edSThomas Graf * skb_seq_read() will return the remaining part of the block. 2530677e90edSThomas Graf * 253125985edcSLucas De Marchi * Note 1: The size of each block of data returned can be arbitrary, 2532677e90edSThomas Graf * this limitation is the cost for zerocopy seqeuental 2533677e90edSThomas Graf * reads of potentially non linear data. 2534677e90edSThomas Graf * 2535bc2cda1eSRandy Dunlap * Note 2: Fragment lists within fragments are not implemented 2536677e90edSThomas Graf * at the moment, state->root_skb could be replaced with 2537677e90edSThomas Graf * a stack for this purpose. 2538677e90edSThomas Graf */ 2539677e90edSThomas Graf unsigned int skb_seq_read(unsigned int consumed, const u8 **data, 2540677e90edSThomas Graf struct skb_seq_state *st) 2541677e90edSThomas Graf { 2542677e90edSThomas Graf unsigned int block_limit, abs_offset = consumed + st->lower_offset; 2543677e90edSThomas Graf skb_frag_t *frag; 2544677e90edSThomas Graf 2545677e90edSThomas Graf if (unlikely(abs_offset >= st->upper_offset)) 2546677e90edSThomas Graf return 0; 2547677e90edSThomas Graf 2548677e90edSThomas Graf next_skb: 254995e3b24cSHerbert Xu block_limit = skb_headlen(st->cur_skb) + st->stepped_offset; 2550677e90edSThomas Graf 2551995b3379SThomas Chenault if (abs_offset < block_limit && !st->frag_data) { 255295e3b24cSHerbert Xu *data = st->cur_skb->data + (abs_offset - st->stepped_offset); 2553677e90edSThomas Graf return block_limit - abs_offset; 2554677e90edSThomas Graf } 2555677e90edSThomas Graf 2556677e90edSThomas Graf if (st->frag_idx == 0 && !st->frag_data) 2557677e90edSThomas Graf st->stepped_offset += skb_headlen(st->cur_skb); 2558677e90edSThomas Graf 2559677e90edSThomas Graf while (st->frag_idx < skb_shinfo(st->cur_skb)->nr_frags) { 2560677e90edSThomas Graf frag = &skb_shinfo(st->cur_skb)->frags[st->frag_idx]; 25619e903e08SEric Dumazet block_limit = skb_frag_size(frag) + st->stepped_offset; 2562677e90edSThomas Graf 2563677e90edSThomas Graf if (abs_offset < block_limit) { 2564677e90edSThomas Graf if (!st->frag_data) 256551c56b00SEric Dumazet st->frag_data = kmap_atomic(skb_frag_page(frag)); 2566677e90edSThomas Graf 2567677e90edSThomas Graf *data = (u8 *) st->frag_data + frag->page_offset + 2568677e90edSThomas Graf (abs_offset - st->stepped_offset); 2569677e90edSThomas Graf 2570677e90edSThomas Graf return block_limit - abs_offset; 2571677e90edSThomas Graf } 2572677e90edSThomas Graf 2573677e90edSThomas Graf if (st->frag_data) { 257451c56b00SEric Dumazet kunmap_atomic(st->frag_data); 2575677e90edSThomas Graf st->frag_data = NULL; 2576677e90edSThomas Graf } 2577677e90edSThomas Graf 2578677e90edSThomas Graf st->frag_idx++; 25799e903e08SEric Dumazet st->stepped_offset += skb_frag_size(frag); 2580677e90edSThomas Graf } 2581677e90edSThomas Graf 25825b5a60daSOlaf Kirch if (st->frag_data) { 258351c56b00SEric Dumazet kunmap_atomic(st->frag_data); 25845b5a60daSOlaf Kirch st->frag_data = NULL; 25855b5a60daSOlaf Kirch } 25865b5a60daSOlaf Kirch 258721dc3301SDavid S. Miller if (st->root_skb == st->cur_skb && skb_has_frag_list(st->root_skb)) { 2588677e90edSThomas Graf st->cur_skb = skb_shinfo(st->root_skb)->frag_list; 258995e3b24cSHerbert Xu st->frag_idx = 0; 2590677e90edSThomas Graf goto next_skb; 259171b3346dSShyam Iyer } else if (st->cur_skb->next) { 259271b3346dSShyam Iyer st->cur_skb = st->cur_skb->next; 259371b3346dSShyam Iyer st->frag_idx = 0; 2594677e90edSThomas Graf goto next_skb; 2595677e90edSThomas Graf } 2596677e90edSThomas Graf 2597677e90edSThomas Graf return 0; 2598677e90edSThomas Graf } 2599b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_seq_read); 2600677e90edSThomas Graf 2601677e90edSThomas Graf /** 2602677e90edSThomas Graf * skb_abort_seq_read - Abort a sequential read of skb data 2603677e90edSThomas Graf * @st: state variable 2604677e90edSThomas Graf * 2605677e90edSThomas Graf * Must be called if skb_seq_read() was not called until it 2606677e90edSThomas Graf * returned 0. 2607677e90edSThomas Graf */ 2608677e90edSThomas Graf void skb_abort_seq_read(struct skb_seq_state *st) 2609677e90edSThomas Graf { 2610677e90edSThomas Graf if (st->frag_data) 261151c56b00SEric Dumazet kunmap_atomic(st->frag_data); 2612677e90edSThomas Graf } 2613b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_abort_seq_read); 2614677e90edSThomas Graf 26153fc7e8a6SThomas Graf #define TS_SKB_CB(state) ((struct skb_seq_state *) &((state)->cb)) 26163fc7e8a6SThomas Graf 26173fc7e8a6SThomas Graf static unsigned int skb_ts_get_next_block(unsigned int offset, const u8 **text, 26183fc7e8a6SThomas Graf struct ts_config *conf, 26193fc7e8a6SThomas Graf struct ts_state *state) 26203fc7e8a6SThomas Graf { 26213fc7e8a6SThomas Graf return skb_seq_read(offset, text, TS_SKB_CB(state)); 26223fc7e8a6SThomas Graf } 26233fc7e8a6SThomas Graf 26243fc7e8a6SThomas Graf static void skb_ts_finish(struct ts_config *conf, struct ts_state *state) 26253fc7e8a6SThomas Graf { 26263fc7e8a6SThomas Graf skb_abort_seq_read(TS_SKB_CB(state)); 26273fc7e8a6SThomas Graf } 26283fc7e8a6SThomas Graf 26293fc7e8a6SThomas Graf /** 26303fc7e8a6SThomas Graf * skb_find_text - Find a text pattern in skb data 26313fc7e8a6SThomas Graf * @skb: the buffer to look in 26323fc7e8a6SThomas Graf * @from: search offset 26333fc7e8a6SThomas Graf * @to: search limit 26343fc7e8a6SThomas Graf * @config: textsearch configuration 26353fc7e8a6SThomas Graf * @state: uninitialized textsearch state variable 26363fc7e8a6SThomas Graf * 26373fc7e8a6SThomas Graf * Finds a pattern in the skb data according to the specified 26383fc7e8a6SThomas Graf * textsearch configuration. Use textsearch_next() to retrieve 26393fc7e8a6SThomas Graf * subsequent occurrences of the pattern. Returns the offset 26403fc7e8a6SThomas Graf * to the first occurrence or UINT_MAX if no match was found. 26413fc7e8a6SThomas Graf */ 26423fc7e8a6SThomas Graf unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, 26433fc7e8a6SThomas Graf unsigned int to, struct ts_config *config, 26443fc7e8a6SThomas Graf struct ts_state *state) 26453fc7e8a6SThomas Graf { 2646f72b948dSPhil Oester unsigned int ret; 2647f72b948dSPhil Oester 26483fc7e8a6SThomas Graf config->get_next_block = skb_ts_get_next_block; 26493fc7e8a6SThomas Graf config->finish = skb_ts_finish; 26503fc7e8a6SThomas Graf 26513fc7e8a6SThomas Graf skb_prepare_seq_read(skb, from, to, TS_SKB_CB(state)); 26523fc7e8a6SThomas Graf 2653f72b948dSPhil Oester ret = textsearch_find(config, state); 2654f72b948dSPhil Oester return (ret <= to - from ? ret : UINT_MAX); 26553fc7e8a6SThomas Graf } 2656b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_find_text); 26573fc7e8a6SThomas Graf 2658e89e9cf5SAnanda Raju /** 26592c53040fSBen Hutchings * skb_append_datato_frags - append the user data to a skb 2660e89e9cf5SAnanda Raju * @sk: sock structure 2661e89e9cf5SAnanda Raju * @skb: skb structure to be appened with user data. 2662e89e9cf5SAnanda Raju * @getfrag: call back function to be used for getting the user data 2663e89e9cf5SAnanda Raju * @from: pointer to user message iov 2664e89e9cf5SAnanda Raju * @length: length of the iov message 2665e89e9cf5SAnanda Raju * 2666e89e9cf5SAnanda Raju * Description: This procedure append the user data in the fragment part 2667e89e9cf5SAnanda Raju * of the skb if any page alloc fails user this procedure returns -ENOMEM 2668e89e9cf5SAnanda Raju */ 2669e89e9cf5SAnanda Raju int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, 2670dab9630fSMartin Waitz int (*getfrag)(void *from, char *to, int offset, 2671e89e9cf5SAnanda Raju int len, int odd, struct sk_buff *skb), 2672e89e9cf5SAnanda Raju void *from, int length) 2673e89e9cf5SAnanda Raju { 2674b2111724SEric Dumazet int frg_cnt = skb_shinfo(skb)->nr_frags; 2675b2111724SEric Dumazet int copy; 2676e89e9cf5SAnanda Raju int offset = 0; 2677e89e9cf5SAnanda Raju int ret; 2678b2111724SEric Dumazet struct page_frag *pfrag = ¤t->task_frag; 2679e89e9cf5SAnanda Raju 2680e89e9cf5SAnanda Raju do { 2681e89e9cf5SAnanda Raju /* Return error if we don't have space for new frag */ 2682e89e9cf5SAnanda Raju if (frg_cnt >= MAX_SKB_FRAGS) 2683b2111724SEric Dumazet return -EMSGSIZE; 2684e89e9cf5SAnanda Raju 2685b2111724SEric Dumazet if (!sk_page_frag_refill(sk, pfrag)) 2686e89e9cf5SAnanda Raju return -ENOMEM; 2687e89e9cf5SAnanda Raju 2688e89e9cf5SAnanda Raju /* copy the user data to page */ 2689b2111724SEric Dumazet copy = min_t(int, length, pfrag->size - pfrag->offset); 2690e89e9cf5SAnanda Raju 2691b2111724SEric Dumazet ret = getfrag(from, page_address(pfrag->page) + pfrag->offset, 2692e89e9cf5SAnanda Raju offset, copy, 0, skb); 2693e89e9cf5SAnanda Raju if (ret < 0) 2694e89e9cf5SAnanda Raju return -EFAULT; 2695e89e9cf5SAnanda Raju 2696e89e9cf5SAnanda Raju /* copy was successful so update the size parameters */ 2697b2111724SEric Dumazet skb_fill_page_desc(skb, frg_cnt, pfrag->page, pfrag->offset, 2698b2111724SEric Dumazet copy); 2699b2111724SEric Dumazet frg_cnt++; 2700b2111724SEric Dumazet pfrag->offset += copy; 2701b2111724SEric Dumazet get_page(pfrag->page); 2702b2111724SEric Dumazet 2703b2111724SEric Dumazet skb->truesize += copy; 2704b2111724SEric Dumazet atomic_add(copy, &sk->sk_wmem_alloc); 2705e89e9cf5SAnanda Raju skb->len += copy; 2706e89e9cf5SAnanda Raju skb->data_len += copy; 2707e89e9cf5SAnanda Raju offset += copy; 2708e89e9cf5SAnanda Raju length -= copy; 2709e89e9cf5SAnanda Raju 2710e89e9cf5SAnanda Raju } while (length > 0); 2711e89e9cf5SAnanda Raju 2712e89e9cf5SAnanda Raju return 0; 2713e89e9cf5SAnanda Raju } 2714b4ac530fSDavid S. Miller EXPORT_SYMBOL(skb_append_datato_frags); 2715e89e9cf5SAnanda Raju 2716cbb042f9SHerbert Xu /** 2717cbb042f9SHerbert Xu * skb_pull_rcsum - pull skb and update receive checksum 2718cbb042f9SHerbert Xu * @skb: buffer to update 2719cbb042f9SHerbert Xu * @len: length of data pulled 2720cbb042f9SHerbert Xu * 2721cbb042f9SHerbert Xu * This function performs an skb_pull on the packet and updates 2722fee54fa5SUrs Thuermann * the CHECKSUM_COMPLETE checksum. It should be used on 272384fa7933SPatrick McHardy * receive path processing instead of skb_pull unless you know 272484fa7933SPatrick McHardy * that the checksum difference is zero (e.g., a valid IP header) 272584fa7933SPatrick McHardy * or you are setting ip_summed to CHECKSUM_NONE. 2726cbb042f9SHerbert Xu */ 2727cbb042f9SHerbert Xu unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len) 2728cbb042f9SHerbert Xu { 2729cbb042f9SHerbert Xu BUG_ON(len > skb->len); 2730cbb042f9SHerbert Xu skb->len -= len; 2731cbb042f9SHerbert Xu BUG_ON(skb->len < skb->data_len); 2732cbb042f9SHerbert Xu skb_postpull_rcsum(skb, skb->data, len); 2733cbb042f9SHerbert Xu return skb->data += len; 2734cbb042f9SHerbert Xu } 2735f94691acSArnaldo Carvalho de Melo EXPORT_SYMBOL_GPL(skb_pull_rcsum); 2736f94691acSArnaldo Carvalho de Melo 2737f4c50d99SHerbert Xu /** 2738f4c50d99SHerbert Xu * skb_segment - Perform protocol segmentation on skb. 2739f4c50d99SHerbert Xu * @skb: buffer to segment 2740576a30ebSHerbert Xu * @features: features for the output path (see dev->features) 2741f4c50d99SHerbert Xu * 2742f4c50d99SHerbert Xu * This function performs segmentation on the given skb. It returns 27434c821d75SBen Hutchings * a pointer to the first in a list of new skbs for the segments. 27444c821d75SBen Hutchings * In case of error it returns ERR_PTR(err). 2745f4c50d99SHerbert Xu */ 2746c8f44affSMichał Mirosław struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features) 2747f4c50d99SHerbert Xu { 2748f4c50d99SHerbert Xu struct sk_buff *segs = NULL; 2749f4c50d99SHerbert Xu struct sk_buff *tail = NULL; 275089319d38SHerbert Xu struct sk_buff *fskb = skb_shinfo(skb)->frag_list; 2751f4c50d99SHerbert Xu unsigned int mss = skb_shinfo(skb)->gso_size; 275298e399f8SArnaldo Carvalho de Melo unsigned int doffset = skb->data - skb_mac_header(skb); 2753f4c50d99SHerbert Xu unsigned int offset = doffset; 2754f4c50d99SHerbert Xu unsigned int headroom; 2755f4c50d99SHerbert Xu unsigned int len; 275604ed3e74SMichał Mirosław int sg = !!(features & NETIF_F_SG); 2757f4c50d99SHerbert Xu int nfrags = skb_shinfo(skb)->nr_frags; 2758f4c50d99SHerbert Xu int err = -ENOMEM; 2759f4c50d99SHerbert Xu int i = 0; 2760f4c50d99SHerbert Xu int pos; 2761f4c50d99SHerbert Xu 2762f4c50d99SHerbert Xu __skb_push(skb, doffset); 2763f4c50d99SHerbert Xu headroom = skb_headroom(skb); 2764f4c50d99SHerbert Xu pos = skb_headlen(skb); 2765f4c50d99SHerbert Xu 2766f4c50d99SHerbert Xu do { 2767f4c50d99SHerbert Xu struct sk_buff *nskb; 2768f4c50d99SHerbert Xu skb_frag_t *frag; 2769c8884eddSHerbert Xu int hsize; 2770f4c50d99SHerbert Xu int size; 2771f4c50d99SHerbert Xu 2772f4c50d99SHerbert Xu len = skb->len - offset; 2773f4c50d99SHerbert Xu if (len > mss) 2774f4c50d99SHerbert Xu len = mss; 2775f4c50d99SHerbert Xu 2776f4c50d99SHerbert Xu hsize = skb_headlen(skb) - offset; 2777f4c50d99SHerbert Xu if (hsize < 0) 2778f4c50d99SHerbert Xu hsize = 0; 2779c8884eddSHerbert Xu if (hsize > len || !sg) 2780c8884eddSHerbert Xu hsize = len; 2781f4c50d99SHerbert Xu 278289319d38SHerbert Xu if (!hsize && i >= nfrags) { 278389319d38SHerbert Xu BUG_ON(fskb->len != len); 278489319d38SHerbert Xu 278589319d38SHerbert Xu pos += len; 278689319d38SHerbert Xu nskb = skb_clone(fskb, GFP_ATOMIC); 278789319d38SHerbert Xu fskb = fskb->next; 278889319d38SHerbert Xu 2789f4c50d99SHerbert Xu if (unlikely(!nskb)) 2790f4c50d99SHerbert Xu goto err; 2791f4c50d99SHerbert Xu 2792ec47ea82SAlexander Duyck hsize = skb_end_offset(nskb); 279389319d38SHerbert Xu if (skb_cow_head(nskb, doffset + headroom)) { 279489319d38SHerbert Xu kfree_skb(nskb); 279589319d38SHerbert Xu goto err; 279689319d38SHerbert Xu } 279789319d38SHerbert Xu 2798ec47ea82SAlexander Duyck nskb->truesize += skb_end_offset(nskb) - hsize; 279989319d38SHerbert Xu skb_release_head_state(nskb); 280089319d38SHerbert Xu __skb_push(nskb, doffset); 280189319d38SHerbert Xu } else { 2802c93bdd0eSMel Gorman nskb = __alloc_skb(hsize + doffset + headroom, 2803c93bdd0eSMel Gorman GFP_ATOMIC, skb_alloc_rx_flag(skb), 2804c93bdd0eSMel Gorman NUMA_NO_NODE); 280589319d38SHerbert Xu 280689319d38SHerbert Xu if (unlikely(!nskb)) 280789319d38SHerbert Xu goto err; 280889319d38SHerbert Xu 280989319d38SHerbert Xu skb_reserve(nskb, headroom); 281089319d38SHerbert Xu __skb_put(nskb, doffset); 281189319d38SHerbert Xu } 281289319d38SHerbert Xu 2813f4c50d99SHerbert Xu if (segs) 2814f4c50d99SHerbert Xu tail->next = nskb; 2815f4c50d99SHerbert Xu else 2816f4c50d99SHerbert Xu segs = nskb; 2817f4c50d99SHerbert Xu tail = nskb; 2818f4c50d99SHerbert Xu 28196f85a124SHerbert Xu __copy_skb_header(nskb, skb); 2820f4c50d99SHerbert Xu nskb->mac_len = skb->mac_len; 2821f4c50d99SHerbert Xu 28223d3be433SEric Dumazet /* nskb and skb might have different headroom */ 28233d3be433SEric Dumazet if (nskb->ip_summed == CHECKSUM_PARTIAL) 28243d3be433SEric Dumazet nskb->csum_start += skb_headroom(nskb) - headroom; 28253d3be433SEric Dumazet 2826459a98edSArnaldo Carvalho de Melo skb_reset_mac_header(nskb); 2827ddc7b8e3SArnaldo Carvalho de Melo skb_set_network_header(nskb, skb->mac_len); 2828b0e380b1SArnaldo Carvalho de Melo nskb->transport_header = (nskb->network_header + 2829b0e380b1SArnaldo Carvalho de Melo skb_network_header_len(skb)); 283089319d38SHerbert Xu skb_copy_from_linear_data(skb, nskb->data, doffset); 283189319d38SHerbert Xu 28322f181855SHerbert Xu if (fskb != skb_shinfo(skb)->frag_list) 283389319d38SHerbert Xu continue; 283489319d38SHerbert Xu 2835f4c50d99SHerbert Xu if (!sg) { 28366f85a124SHerbert Xu nskb->ip_summed = CHECKSUM_NONE; 2837f4c50d99SHerbert Xu nskb->csum = skb_copy_and_csum_bits(skb, offset, 2838f4c50d99SHerbert Xu skb_put(nskb, len), 2839f4c50d99SHerbert Xu len, 0); 2840f4c50d99SHerbert Xu continue; 2841f4c50d99SHerbert Xu } 2842f4c50d99SHerbert Xu 2843f4c50d99SHerbert Xu frag = skb_shinfo(nskb)->frags; 2844f4c50d99SHerbert Xu 2845d626f62bSArnaldo Carvalho de Melo skb_copy_from_linear_data_offset(skb, offset, 2846d626f62bSArnaldo Carvalho de Melo skb_put(nskb, hsize), hsize); 2847f4c50d99SHerbert Xu 284889319d38SHerbert Xu while (pos < offset + len && i < nfrags) { 2849f4c50d99SHerbert Xu *frag = skb_shinfo(skb)->frags[i]; 2850ea2ab693SIan Campbell __skb_frag_ref(frag); 28519e903e08SEric Dumazet size = skb_frag_size(frag); 2852f4c50d99SHerbert Xu 2853f4c50d99SHerbert Xu if (pos < offset) { 2854f4c50d99SHerbert Xu frag->page_offset += offset - pos; 28559e903e08SEric Dumazet skb_frag_size_sub(frag, offset - pos); 2856f4c50d99SHerbert Xu } 2857f4c50d99SHerbert Xu 285889319d38SHerbert Xu skb_shinfo(nskb)->nr_frags++; 2859f4c50d99SHerbert Xu 2860f4c50d99SHerbert Xu if (pos + size <= offset + len) { 2861f4c50d99SHerbert Xu i++; 2862f4c50d99SHerbert Xu pos += size; 2863f4c50d99SHerbert Xu } else { 28649e903e08SEric Dumazet skb_frag_size_sub(frag, pos + size - (offset + len)); 286589319d38SHerbert Xu goto skip_fraglist; 2866f4c50d99SHerbert Xu } 2867f4c50d99SHerbert Xu 2868f4c50d99SHerbert Xu frag++; 2869f4c50d99SHerbert Xu } 2870f4c50d99SHerbert Xu 287189319d38SHerbert Xu if (pos < offset + len) { 287289319d38SHerbert Xu struct sk_buff *fskb2 = fskb; 287389319d38SHerbert Xu 287489319d38SHerbert Xu BUG_ON(pos + fskb->len != offset + len); 287589319d38SHerbert Xu 287689319d38SHerbert Xu pos += fskb->len; 287789319d38SHerbert Xu fskb = fskb->next; 287889319d38SHerbert Xu 287989319d38SHerbert Xu if (fskb2->next) { 288089319d38SHerbert Xu fskb2 = skb_clone(fskb2, GFP_ATOMIC); 288189319d38SHerbert Xu if (!fskb2) 288289319d38SHerbert Xu goto err; 288389319d38SHerbert Xu } else 288489319d38SHerbert Xu skb_get(fskb2); 288589319d38SHerbert Xu 2886fbb398a8SDavid S. Miller SKB_FRAG_ASSERT(nskb); 288789319d38SHerbert Xu skb_shinfo(nskb)->frag_list = fskb2; 288889319d38SHerbert Xu } 288989319d38SHerbert Xu 289089319d38SHerbert Xu skip_fraglist: 2891f4c50d99SHerbert Xu nskb->data_len = len - hsize; 2892f4c50d99SHerbert Xu nskb->len += nskb->data_len; 2893f4c50d99SHerbert Xu nskb->truesize += nskb->data_len; 2894f4c50d99SHerbert Xu } while ((offset += len) < skb->len); 2895f4c50d99SHerbert Xu 2896f4c50d99SHerbert Xu return segs; 2897f4c50d99SHerbert Xu 2898f4c50d99SHerbert Xu err: 2899f4c50d99SHerbert Xu while ((skb = segs)) { 2900f4c50d99SHerbert Xu segs = skb->next; 2901b08d5840SPatrick McHardy kfree_skb(skb); 2902f4c50d99SHerbert Xu } 2903f4c50d99SHerbert Xu return ERR_PTR(err); 2904f4c50d99SHerbert Xu } 2905f4c50d99SHerbert Xu EXPORT_SYMBOL_GPL(skb_segment); 2906f4c50d99SHerbert Xu 290771d93b39SHerbert Xu int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb) 290871d93b39SHerbert Xu { 290971d93b39SHerbert Xu struct sk_buff *p = *head; 291071d93b39SHerbert Xu struct sk_buff *nskb; 29119aaa156cSHerbert Xu struct skb_shared_info *skbinfo = skb_shinfo(skb); 29129aaa156cSHerbert Xu struct skb_shared_info *pinfo = skb_shinfo(p); 291371d93b39SHerbert Xu unsigned int headroom; 291486911732SHerbert Xu unsigned int len = skb_gro_len(skb); 291567147ba9SHerbert Xu unsigned int offset = skb_gro_offset(skb); 291667147ba9SHerbert Xu unsigned int headlen = skb_headlen(skb); 2917715dc1f3SEric Dumazet unsigned int delta_truesize; 291871d93b39SHerbert Xu 291986911732SHerbert Xu if (p->len + len >= 65536) 292071d93b39SHerbert Xu return -E2BIG; 292171d93b39SHerbert Xu 29229aaa156cSHerbert Xu if (pinfo->frag_list) 292371d93b39SHerbert Xu goto merge; 292467147ba9SHerbert Xu else if (headlen <= offset) { 292542da6994SHerbert Xu skb_frag_t *frag; 292666e92fcfSHerbert Xu skb_frag_t *frag2; 29279aaa156cSHerbert Xu int i = skbinfo->nr_frags; 29289aaa156cSHerbert Xu int nr_frags = pinfo->nr_frags + i; 292942da6994SHerbert Xu 293066e92fcfSHerbert Xu offset -= headlen; 293166e92fcfSHerbert Xu 293266e92fcfSHerbert Xu if (nr_frags > MAX_SKB_FRAGS) 293381705ad1SHerbert Xu return -E2BIG; 293481705ad1SHerbert Xu 29359aaa156cSHerbert Xu pinfo->nr_frags = nr_frags; 29369aaa156cSHerbert Xu skbinfo->nr_frags = 0; 2937f5572068SHerbert Xu 29389aaa156cSHerbert Xu frag = pinfo->frags + nr_frags; 29399aaa156cSHerbert Xu frag2 = skbinfo->frags + i; 294066e92fcfSHerbert Xu do { 294166e92fcfSHerbert Xu *--frag = *--frag2; 294266e92fcfSHerbert Xu } while (--i); 294366e92fcfSHerbert Xu 294466e92fcfSHerbert Xu frag->page_offset += offset; 29459e903e08SEric Dumazet skb_frag_size_sub(frag, offset); 294666e92fcfSHerbert Xu 2947715dc1f3SEric Dumazet /* all fragments truesize : remove (head size + sk_buff) */ 2948ec47ea82SAlexander Duyck delta_truesize = skb->truesize - 2949ec47ea82SAlexander Duyck SKB_TRUESIZE(skb_end_offset(skb)); 2950715dc1f3SEric Dumazet 2951f5572068SHerbert Xu skb->truesize -= skb->data_len; 2952f5572068SHerbert Xu skb->len -= skb->data_len; 2953f5572068SHerbert Xu skb->data_len = 0; 2954f5572068SHerbert Xu 2955715dc1f3SEric Dumazet NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE; 29565d38a079SHerbert Xu goto done; 2957d7e8883cSEric Dumazet } else if (skb->head_frag) { 2958d7e8883cSEric Dumazet int nr_frags = pinfo->nr_frags; 2959d7e8883cSEric Dumazet skb_frag_t *frag = pinfo->frags + nr_frags; 2960d7e8883cSEric Dumazet struct page *page = virt_to_head_page(skb->head); 2961d7e8883cSEric Dumazet unsigned int first_size = headlen - offset; 2962d7e8883cSEric Dumazet unsigned int first_offset; 2963d7e8883cSEric Dumazet 2964d7e8883cSEric Dumazet if (nr_frags + 1 + skbinfo->nr_frags > MAX_SKB_FRAGS) 2965d7e8883cSEric Dumazet return -E2BIG; 2966d7e8883cSEric Dumazet 2967d7e8883cSEric Dumazet first_offset = skb->data - 2968d7e8883cSEric Dumazet (unsigned char *)page_address(page) + 2969d7e8883cSEric Dumazet offset; 2970d7e8883cSEric Dumazet 2971d7e8883cSEric Dumazet pinfo->nr_frags = nr_frags + 1 + skbinfo->nr_frags; 2972d7e8883cSEric Dumazet 2973d7e8883cSEric Dumazet frag->page.p = page; 2974d7e8883cSEric Dumazet frag->page_offset = first_offset; 2975d7e8883cSEric Dumazet skb_frag_size_set(frag, first_size); 2976d7e8883cSEric Dumazet 2977d7e8883cSEric Dumazet memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags); 2978d7e8883cSEric Dumazet /* We dont need to clear skbinfo->nr_frags here */ 2979d7e8883cSEric Dumazet 2980715dc1f3SEric Dumazet delta_truesize = skb->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff)); 2981d7e8883cSEric Dumazet NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD; 2982d7e8883cSEric Dumazet goto done; 298369c0cab1SHerbert Xu } else if (skb_gro_len(p) != pinfo->gso_size) 298469c0cab1SHerbert Xu return -E2BIG; 298571d93b39SHerbert Xu 298671d93b39SHerbert Xu headroom = skb_headroom(p); 29873d3be433SEric Dumazet nskb = alloc_skb(headroom + skb_gro_offset(p), GFP_ATOMIC); 298871d93b39SHerbert Xu if (unlikely(!nskb)) 298971d93b39SHerbert Xu return -ENOMEM; 299071d93b39SHerbert Xu 299171d93b39SHerbert Xu __copy_skb_header(nskb, p); 299271d93b39SHerbert Xu nskb->mac_len = p->mac_len; 299371d93b39SHerbert Xu 299471d93b39SHerbert Xu skb_reserve(nskb, headroom); 299586911732SHerbert Xu __skb_put(nskb, skb_gro_offset(p)); 299671d93b39SHerbert Xu 299786911732SHerbert Xu skb_set_mac_header(nskb, skb_mac_header(p) - p->data); 299871d93b39SHerbert Xu skb_set_network_header(nskb, skb_network_offset(p)); 299971d93b39SHerbert Xu skb_set_transport_header(nskb, skb_transport_offset(p)); 300071d93b39SHerbert Xu 300186911732SHerbert Xu __skb_pull(p, skb_gro_offset(p)); 300286911732SHerbert Xu memcpy(skb_mac_header(nskb), skb_mac_header(p), 300386911732SHerbert Xu p->data - skb_mac_header(p)); 300471d93b39SHerbert Xu 300571d93b39SHerbert Xu skb_shinfo(nskb)->frag_list = p; 30069aaa156cSHerbert Xu skb_shinfo(nskb)->gso_size = pinfo->gso_size; 3007622e0ca1SHerbert Xu pinfo->gso_size = 0; 300871d93b39SHerbert Xu skb_header_release(p); 3009c3c7c254SEric Dumazet NAPI_GRO_CB(nskb)->last = p; 301071d93b39SHerbert Xu 301171d93b39SHerbert Xu nskb->data_len += p->len; 3012de8261c2SEric Dumazet nskb->truesize += p->truesize; 301371d93b39SHerbert Xu nskb->len += p->len; 301471d93b39SHerbert Xu 301571d93b39SHerbert Xu *head = nskb; 301671d93b39SHerbert Xu nskb->next = p->next; 301771d93b39SHerbert Xu p->next = NULL; 301871d93b39SHerbert Xu 301971d93b39SHerbert Xu p = nskb; 302071d93b39SHerbert Xu 302171d93b39SHerbert Xu merge: 3022715dc1f3SEric Dumazet delta_truesize = skb->truesize; 302367147ba9SHerbert Xu if (offset > headlen) { 3024d1dc7abfSMichal Schmidt unsigned int eat = offset - headlen; 3025d1dc7abfSMichal Schmidt 3026d1dc7abfSMichal Schmidt skbinfo->frags[0].page_offset += eat; 30279e903e08SEric Dumazet skb_frag_size_sub(&skbinfo->frags[0], eat); 3028d1dc7abfSMichal Schmidt skb->data_len -= eat; 3029d1dc7abfSMichal Schmidt skb->len -= eat; 303067147ba9SHerbert Xu offset = headlen; 303156035022SHerbert Xu } 303256035022SHerbert Xu 303367147ba9SHerbert Xu __skb_pull(skb, offset); 303456035022SHerbert Xu 3035c3c7c254SEric Dumazet NAPI_GRO_CB(p)->last->next = skb; 3036c3c7c254SEric Dumazet NAPI_GRO_CB(p)->last = skb; 303771d93b39SHerbert Xu skb_header_release(skb); 303871d93b39SHerbert Xu 30395d38a079SHerbert Xu done: 30405d38a079SHerbert Xu NAPI_GRO_CB(p)->count++; 304137fe4732SHerbert Xu p->data_len += len; 3042715dc1f3SEric Dumazet p->truesize += delta_truesize; 304337fe4732SHerbert Xu p->len += len; 304471d93b39SHerbert Xu 304571d93b39SHerbert Xu NAPI_GRO_CB(skb)->same_flow = 1; 304671d93b39SHerbert Xu return 0; 304771d93b39SHerbert Xu } 304871d93b39SHerbert Xu EXPORT_SYMBOL_GPL(skb_gro_receive); 304971d93b39SHerbert Xu 30501da177e4SLinus Torvalds void __init skb_init(void) 30511da177e4SLinus Torvalds { 30521da177e4SLinus Torvalds skbuff_head_cache = kmem_cache_create("skbuff_head_cache", 30531da177e4SLinus Torvalds sizeof(struct sk_buff), 30541da177e4SLinus Torvalds 0, 3055e5d679f3SAlexey Dobriyan SLAB_HWCACHE_ALIGN|SLAB_PANIC, 305620c2df83SPaul Mundt NULL); 3057d179cd12SDavid S. Miller skbuff_fclone_cache = kmem_cache_create("skbuff_fclone_cache", 3058d179cd12SDavid S. Miller (2*sizeof(struct sk_buff)) + 3059d179cd12SDavid S. Miller sizeof(atomic_t), 3060d179cd12SDavid S. Miller 0, 3061e5d679f3SAlexey Dobriyan SLAB_HWCACHE_ALIGN|SLAB_PANIC, 306220c2df83SPaul Mundt NULL); 30631da177e4SLinus Torvalds } 30641da177e4SLinus Torvalds 3065716ea3a7SDavid Howells /** 3066716ea3a7SDavid Howells * skb_to_sgvec - Fill a scatter-gather list from a socket buffer 3067716ea3a7SDavid Howells * @skb: Socket buffer containing the buffers to be mapped 3068716ea3a7SDavid Howells * @sg: The scatter-gather list to map into 3069716ea3a7SDavid Howells * @offset: The offset into the buffer's contents to start mapping 3070716ea3a7SDavid Howells * @len: Length of buffer space to be mapped 3071716ea3a7SDavid Howells * 3072716ea3a7SDavid Howells * Fill the specified scatter-gather list with mappings/pointers into a 3073716ea3a7SDavid Howells * region of the buffer space attached to a socket buffer. 3074716ea3a7SDavid Howells */ 307551c739d1SDavid S. Miller static int 307651c739d1SDavid S. Miller __skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) 3077716ea3a7SDavid Howells { 30781a028e50SDavid S. Miller int start = skb_headlen(skb); 30791a028e50SDavid S. Miller int i, copy = start - offset; 3080fbb398a8SDavid S. Miller struct sk_buff *frag_iter; 3081716ea3a7SDavid Howells int elt = 0; 3082716ea3a7SDavid Howells 3083716ea3a7SDavid Howells if (copy > 0) { 3084716ea3a7SDavid Howells if (copy > len) 3085716ea3a7SDavid Howells copy = len; 3086642f1490SJens Axboe sg_set_buf(sg, skb->data + offset, copy); 3087716ea3a7SDavid Howells elt++; 3088716ea3a7SDavid Howells if ((len -= copy) == 0) 3089716ea3a7SDavid Howells return elt; 3090716ea3a7SDavid Howells offset += copy; 3091716ea3a7SDavid Howells } 3092716ea3a7SDavid Howells 3093716ea3a7SDavid Howells for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 30941a028e50SDavid S. Miller int end; 3095716ea3a7SDavid Howells 3096547b792cSIlpo Järvinen WARN_ON(start > offset + len); 30971a028e50SDavid S. Miller 30989e903e08SEric Dumazet end = start + skb_frag_size(&skb_shinfo(skb)->frags[i]); 3099716ea3a7SDavid Howells if ((copy = end - offset) > 0) { 3100716ea3a7SDavid Howells skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; 3101716ea3a7SDavid Howells 3102716ea3a7SDavid Howells if (copy > len) 3103716ea3a7SDavid Howells copy = len; 3104ea2ab693SIan Campbell sg_set_page(&sg[elt], skb_frag_page(frag), copy, 3105642f1490SJens Axboe frag->page_offset+offset-start); 3106716ea3a7SDavid Howells elt++; 3107716ea3a7SDavid Howells if (!(len -= copy)) 3108716ea3a7SDavid Howells return elt; 3109716ea3a7SDavid Howells offset += copy; 3110716ea3a7SDavid Howells } 31111a028e50SDavid S. Miller start = end; 3112716ea3a7SDavid Howells } 3113716ea3a7SDavid Howells 3114fbb398a8SDavid S. Miller skb_walk_frags(skb, frag_iter) { 31151a028e50SDavid S. Miller int end; 3116716ea3a7SDavid Howells 3117547b792cSIlpo Järvinen WARN_ON(start > offset + len); 31181a028e50SDavid S. Miller 3119fbb398a8SDavid S. Miller end = start + frag_iter->len; 3120716ea3a7SDavid Howells if ((copy = end - offset) > 0) { 3121716ea3a7SDavid Howells if (copy > len) 3122716ea3a7SDavid Howells copy = len; 3123fbb398a8SDavid S. Miller elt += __skb_to_sgvec(frag_iter, sg+elt, offset - start, 312451c739d1SDavid S. Miller copy); 3125716ea3a7SDavid Howells if ((len -= copy) == 0) 3126716ea3a7SDavid Howells return elt; 3127716ea3a7SDavid Howells offset += copy; 3128716ea3a7SDavid Howells } 31291a028e50SDavid S. Miller start = end; 3130716ea3a7SDavid Howells } 3131716ea3a7SDavid Howells BUG_ON(len); 3132716ea3a7SDavid Howells return elt; 3133716ea3a7SDavid Howells } 3134716ea3a7SDavid Howells 313551c739d1SDavid S. Miller int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) 313651c739d1SDavid S. Miller { 313751c739d1SDavid S. Miller int nsg = __skb_to_sgvec(skb, sg, offset, len); 313851c739d1SDavid S. Miller 3139c46f2334SJens Axboe sg_mark_end(&sg[nsg - 1]); 314051c739d1SDavid S. Miller 314151c739d1SDavid S. Miller return nsg; 314251c739d1SDavid S. Miller } 3143b4ac530fSDavid S. Miller EXPORT_SYMBOL_GPL(skb_to_sgvec); 314451c739d1SDavid S. Miller 3145716ea3a7SDavid Howells /** 3146716ea3a7SDavid Howells * skb_cow_data - Check that a socket buffer's data buffers are writable 3147716ea3a7SDavid Howells * @skb: The socket buffer to check. 3148716ea3a7SDavid Howells * @tailbits: Amount of trailing space to be added 3149716ea3a7SDavid Howells * @trailer: Returned pointer to the skb where the @tailbits space begins 3150716ea3a7SDavid Howells * 3151716ea3a7SDavid Howells * Make sure that the data buffers attached to a socket buffer are 3152716ea3a7SDavid Howells * writable. If they are not, private copies are made of the data buffers 3153716ea3a7SDavid Howells * and the socket buffer is set to use these instead. 3154716ea3a7SDavid Howells * 3155716ea3a7SDavid Howells * If @tailbits is given, make sure that there is space to write @tailbits 3156716ea3a7SDavid Howells * bytes of data beyond current end of socket buffer. @trailer will be 3157716ea3a7SDavid Howells * set to point to the skb in which this space begins. 3158716ea3a7SDavid Howells * 3159716ea3a7SDavid Howells * The number of scatterlist elements required to completely map the 3160716ea3a7SDavid Howells * COW'd and extended socket buffer will be returned. 3161716ea3a7SDavid Howells */ 3162716ea3a7SDavid Howells int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer) 3163716ea3a7SDavid Howells { 3164716ea3a7SDavid Howells int copyflag; 3165716ea3a7SDavid Howells int elt; 3166716ea3a7SDavid Howells struct sk_buff *skb1, **skb_p; 3167716ea3a7SDavid Howells 3168716ea3a7SDavid Howells /* If skb is cloned or its head is paged, reallocate 3169716ea3a7SDavid Howells * head pulling out all the pages (pages are considered not writable 3170716ea3a7SDavid Howells * at the moment even if they are anonymous). 3171716ea3a7SDavid Howells */ 3172716ea3a7SDavid Howells if ((skb_cloned(skb) || skb_shinfo(skb)->nr_frags) && 3173716ea3a7SDavid Howells __pskb_pull_tail(skb, skb_pagelen(skb)-skb_headlen(skb)) == NULL) 3174716ea3a7SDavid Howells return -ENOMEM; 3175716ea3a7SDavid Howells 3176716ea3a7SDavid Howells /* Easy case. Most of packets will go this way. */ 317721dc3301SDavid S. Miller if (!skb_has_frag_list(skb)) { 3178716ea3a7SDavid Howells /* A little of trouble, not enough of space for trailer. 3179716ea3a7SDavid Howells * This should not happen, when stack is tuned to generate 3180716ea3a7SDavid Howells * good frames. OK, on miss we reallocate and reserve even more 3181716ea3a7SDavid Howells * space, 128 bytes is fair. */ 3182716ea3a7SDavid Howells 3183716ea3a7SDavid Howells if (skb_tailroom(skb) < tailbits && 3184716ea3a7SDavid Howells pskb_expand_head(skb, 0, tailbits-skb_tailroom(skb)+128, GFP_ATOMIC)) 3185716ea3a7SDavid Howells return -ENOMEM; 3186716ea3a7SDavid Howells 3187716ea3a7SDavid Howells /* Voila! */ 3188716ea3a7SDavid Howells *trailer = skb; 3189716ea3a7SDavid Howells return 1; 3190716ea3a7SDavid Howells } 3191716ea3a7SDavid Howells 3192716ea3a7SDavid Howells /* Misery. We are in troubles, going to mincer fragments... */ 3193716ea3a7SDavid Howells 3194716ea3a7SDavid Howells elt = 1; 3195716ea3a7SDavid Howells skb_p = &skb_shinfo(skb)->frag_list; 3196716ea3a7SDavid Howells copyflag = 0; 3197716ea3a7SDavid Howells 3198716ea3a7SDavid Howells while ((skb1 = *skb_p) != NULL) { 3199716ea3a7SDavid Howells int ntail = 0; 3200716ea3a7SDavid Howells 3201716ea3a7SDavid Howells /* The fragment is partially pulled by someone, 3202716ea3a7SDavid Howells * this can happen on input. Copy it and everything 3203716ea3a7SDavid Howells * after it. */ 3204716ea3a7SDavid Howells 3205716ea3a7SDavid Howells if (skb_shared(skb1)) 3206716ea3a7SDavid Howells copyflag = 1; 3207716ea3a7SDavid Howells 3208716ea3a7SDavid Howells /* If the skb is the last, worry about trailer. */ 3209716ea3a7SDavid Howells 3210716ea3a7SDavid Howells if (skb1->next == NULL && tailbits) { 3211716ea3a7SDavid Howells if (skb_shinfo(skb1)->nr_frags || 321221dc3301SDavid S. Miller skb_has_frag_list(skb1) || 3213716ea3a7SDavid Howells skb_tailroom(skb1) < tailbits) 3214716ea3a7SDavid Howells ntail = tailbits + 128; 3215716ea3a7SDavid Howells } 3216716ea3a7SDavid Howells 3217716ea3a7SDavid Howells if (copyflag || 3218716ea3a7SDavid Howells skb_cloned(skb1) || 3219716ea3a7SDavid Howells ntail || 3220716ea3a7SDavid Howells skb_shinfo(skb1)->nr_frags || 322121dc3301SDavid S. Miller skb_has_frag_list(skb1)) { 3222716ea3a7SDavid Howells struct sk_buff *skb2; 3223716ea3a7SDavid Howells 3224716ea3a7SDavid Howells /* Fuck, we are miserable poor guys... */ 3225716ea3a7SDavid Howells if (ntail == 0) 3226716ea3a7SDavid Howells skb2 = skb_copy(skb1, GFP_ATOMIC); 3227716ea3a7SDavid Howells else 3228716ea3a7SDavid Howells skb2 = skb_copy_expand(skb1, 3229716ea3a7SDavid Howells skb_headroom(skb1), 3230716ea3a7SDavid Howells ntail, 3231716ea3a7SDavid Howells GFP_ATOMIC); 3232716ea3a7SDavid Howells if (unlikely(skb2 == NULL)) 3233716ea3a7SDavid Howells return -ENOMEM; 3234716ea3a7SDavid Howells 3235716ea3a7SDavid Howells if (skb1->sk) 3236716ea3a7SDavid Howells skb_set_owner_w(skb2, skb1->sk); 3237716ea3a7SDavid Howells 3238716ea3a7SDavid Howells /* Looking around. Are we still alive? 3239716ea3a7SDavid Howells * OK, link new skb, drop old one */ 3240716ea3a7SDavid Howells 3241716ea3a7SDavid Howells skb2->next = skb1->next; 3242716ea3a7SDavid Howells *skb_p = skb2; 3243716ea3a7SDavid Howells kfree_skb(skb1); 3244716ea3a7SDavid Howells skb1 = skb2; 3245716ea3a7SDavid Howells } 3246716ea3a7SDavid Howells elt++; 3247716ea3a7SDavid Howells *trailer = skb1; 3248716ea3a7SDavid Howells skb_p = &skb1->next; 3249716ea3a7SDavid Howells } 3250716ea3a7SDavid Howells 3251716ea3a7SDavid Howells return elt; 3252716ea3a7SDavid Howells } 3253b4ac530fSDavid S. Miller EXPORT_SYMBOL_GPL(skb_cow_data); 3254716ea3a7SDavid Howells 3255b1faf566SEric Dumazet static void sock_rmem_free(struct sk_buff *skb) 3256b1faf566SEric Dumazet { 3257b1faf566SEric Dumazet struct sock *sk = skb->sk; 3258b1faf566SEric Dumazet 3259b1faf566SEric Dumazet atomic_sub(skb->truesize, &sk->sk_rmem_alloc); 3260b1faf566SEric Dumazet } 3261b1faf566SEric Dumazet 3262b1faf566SEric Dumazet /* 3263b1faf566SEric Dumazet * Note: We dont mem charge error packets (no sk_forward_alloc changes) 3264b1faf566SEric Dumazet */ 3265b1faf566SEric Dumazet int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb) 3266b1faf566SEric Dumazet { 3267110c4330SEric Dumazet int len = skb->len; 3268110c4330SEric Dumazet 3269b1faf566SEric Dumazet if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= 327095c96174SEric Dumazet (unsigned int)sk->sk_rcvbuf) 3271b1faf566SEric Dumazet return -ENOMEM; 3272b1faf566SEric Dumazet 3273b1faf566SEric Dumazet skb_orphan(skb); 3274b1faf566SEric Dumazet skb->sk = sk; 3275b1faf566SEric Dumazet skb->destructor = sock_rmem_free; 3276b1faf566SEric Dumazet atomic_add(skb->truesize, &sk->sk_rmem_alloc); 3277b1faf566SEric Dumazet 3278abb57ea4SEric Dumazet /* before exiting rcu section, make sure dst is refcounted */ 3279abb57ea4SEric Dumazet skb_dst_force(skb); 3280abb57ea4SEric Dumazet 3281b1faf566SEric Dumazet skb_queue_tail(&sk->sk_error_queue, skb); 3282b1faf566SEric Dumazet if (!sock_flag(sk, SOCK_DEAD)) 3283110c4330SEric Dumazet sk->sk_data_ready(sk, len); 3284b1faf566SEric Dumazet return 0; 3285b1faf566SEric Dumazet } 3286b1faf566SEric Dumazet EXPORT_SYMBOL(sock_queue_err_skb); 3287b1faf566SEric Dumazet 3288ac45f602SPatrick Ohly void skb_tstamp_tx(struct sk_buff *orig_skb, 3289ac45f602SPatrick Ohly struct skb_shared_hwtstamps *hwtstamps) 3290ac45f602SPatrick Ohly { 3291ac45f602SPatrick Ohly struct sock *sk = orig_skb->sk; 3292ac45f602SPatrick Ohly struct sock_exterr_skb *serr; 3293ac45f602SPatrick Ohly struct sk_buff *skb; 3294ac45f602SPatrick Ohly int err; 3295ac45f602SPatrick Ohly 3296ac45f602SPatrick Ohly if (!sk) 3297ac45f602SPatrick Ohly return; 3298ac45f602SPatrick Ohly 3299ac45f602SPatrick Ohly skb = skb_clone(orig_skb, GFP_ATOMIC); 3300ac45f602SPatrick Ohly if (!skb) 3301ac45f602SPatrick Ohly return; 3302ac45f602SPatrick Ohly 3303ac45f602SPatrick Ohly if (hwtstamps) { 3304ac45f602SPatrick Ohly *skb_hwtstamps(skb) = 3305ac45f602SPatrick Ohly *hwtstamps; 3306ac45f602SPatrick Ohly } else { 3307ac45f602SPatrick Ohly /* 3308ac45f602SPatrick Ohly * no hardware time stamps available, 33092244d07bSOliver Hartkopp * so keep the shared tx_flags and only 3310ac45f602SPatrick Ohly * store software time stamp 3311ac45f602SPatrick Ohly */ 3312ac45f602SPatrick Ohly skb->tstamp = ktime_get_real(); 3313ac45f602SPatrick Ohly } 3314ac45f602SPatrick Ohly 3315ac45f602SPatrick Ohly serr = SKB_EXT_ERR(skb); 3316ac45f602SPatrick Ohly memset(serr, 0, sizeof(*serr)); 3317ac45f602SPatrick Ohly serr->ee.ee_errno = ENOMSG; 3318ac45f602SPatrick Ohly serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING; 331929030374SEric Dumazet 3320ac45f602SPatrick Ohly err = sock_queue_err_skb(sk, skb); 332129030374SEric Dumazet 3322ac45f602SPatrick Ohly if (err) 3323ac45f602SPatrick Ohly kfree_skb(skb); 3324ac45f602SPatrick Ohly } 3325ac45f602SPatrick Ohly EXPORT_SYMBOL_GPL(skb_tstamp_tx); 3326ac45f602SPatrick Ohly 33276e3e939fSJohannes Berg void skb_complete_wifi_ack(struct sk_buff *skb, bool acked) 33286e3e939fSJohannes Berg { 33296e3e939fSJohannes Berg struct sock *sk = skb->sk; 33306e3e939fSJohannes Berg struct sock_exterr_skb *serr; 33316e3e939fSJohannes Berg int err; 33326e3e939fSJohannes Berg 33336e3e939fSJohannes Berg skb->wifi_acked_valid = 1; 33346e3e939fSJohannes Berg skb->wifi_acked = acked; 33356e3e939fSJohannes Berg 33366e3e939fSJohannes Berg serr = SKB_EXT_ERR(skb); 33376e3e939fSJohannes Berg memset(serr, 0, sizeof(*serr)); 33386e3e939fSJohannes Berg serr->ee.ee_errno = ENOMSG; 33396e3e939fSJohannes Berg serr->ee.ee_origin = SO_EE_ORIGIN_TXSTATUS; 33406e3e939fSJohannes Berg 33416e3e939fSJohannes Berg err = sock_queue_err_skb(sk, skb); 33426e3e939fSJohannes Berg if (err) 33436e3e939fSJohannes Berg kfree_skb(skb); 33446e3e939fSJohannes Berg } 33456e3e939fSJohannes Berg EXPORT_SYMBOL_GPL(skb_complete_wifi_ack); 33466e3e939fSJohannes Berg 3347ac45f602SPatrick Ohly 3348f35d9d8aSRusty Russell /** 3349f35d9d8aSRusty Russell * skb_partial_csum_set - set up and verify partial csum values for packet 3350f35d9d8aSRusty Russell * @skb: the skb to set 3351f35d9d8aSRusty Russell * @start: the number of bytes after skb->data to start checksumming. 3352f35d9d8aSRusty Russell * @off: the offset from start to place the checksum. 3353f35d9d8aSRusty Russell * 3354f35d9d8aSRusty Russell * For untrusted partially-checksummed packets, we need to make sure the values 3355f35d9d8aSRusty Russell * for skb->csum_start and skb->csum_offset are valid so we don't oops. 3356f35d9d8aSRusty Russell * 3357f35d9d8aSRusty Russell * This function checks and sets those values and skb->ip_summed: if this 3358f35d9d8aSRusty Russell * returns false you should drop the packet. 3359f35d9d8aSRusty Russell */ 3360f35d9d8aSRusty Russell bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off) 3361f35d9d8aSRusty Russell { 33625ff8dda3SHerbert Xu if (unlikely(start > skb_headlen(skb)) || 33635ff8dda3SHerbert Xu unlikely((int)start + off > skb_headlen(skb) - 2)) { 3364e87cc472SJoe Perches net_warn_ratelimited("bad partial csum: csum=%u/%u len=%u\n", 33655ff8dda3SHerbert Xu start, off, skb_headlen(skb)); 3366f35d9d8aSRusty Russell return false; 3367f35d9d8aSRusty Russell } 3368f35d9d8aSRusty Russell skb->ip_summed = CHECKSUM_PARTIAL; 3369f35d9d8aSRusty Russell skb->csum_start = skb_headroom(skb) + start; 3370f35d9d8aSRusty Russell skb->csum_offset = off; 3371f35d9d8aSRusty Russell return true; 3372f35d9d8aSRusty Russell } 3373b4ac530fSDavid S. Miller EXPORT_SYMBOL_GPL(skb_partial_csum_set); 3374f35d9d8aSRusty Russell 33754497b076SBen Hutchings void __skb_warn_lro_forwarding(const struct sk_buff *skb) 33764497b076SBen Hutchings { 3377e87cc472SJoe Perches net_warn_ratelimited("%s: received packets cannot be forwarded while LRO is enabled\n", 3378e87cc472SJoe Perches skb->dev->name); 33794497b076SBen Hutchings } 33804497b076SBen Hutchings EXPORT_SYMBOL(__skb_warn_lro_forwarding); 3381bad43ca8SEric Dumazet 3382bad43ca8SEric Dumazet void kfree_skb_partial(struct sk_buff *skb, bool head_stolen) 3383bad43ca8SEric Dumazet { 33843d861f66SEric Dumazet if (head_stolen) { 33853d861f66SEric Dumazet skb_release_head_state(skb); 3386bad43ca8SEric Dumazet kmem_cache_free(skbuff_head_cache, skb); 33873d861f66SEric Dumazet } else { 3388bad43ca8SEric Dumazet __kfree_skb(skb); 3389bad43ca8SEric Dumazet } 33903d861f66SEric Dumazet } 3391bad43ca8SEric Dumazet EXPORT_SYMBOL(kfree_skb_partial); 3392bad43ca8SEric Dumazet 3393bad43ca8SEric Dumazet /** 3394bad43ca8SEric Dumazet * skb_try_coalesce - try to merge skb to prior one 3395bad43ca8SEric Dumazet * @to: prior buffer 3396bad43ca8SEric Dumazet * @from: buffer to add 3397bad43ca8SEric Dumazet * @fragstolen: pointer to boolean 3398c6c4b97cSRandy Dunlap * @delta_truesize: how much more was allocated than was requested 3399bad43ca8SEric Dumazet */ 3400bad43ca8SEric Dumazet bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, 3401bad43ca8SEric Dumazet bool *fragstolen, int *delta_truesize) 3402bad43ca8SEric Dumazet { 3403bad43ca8SEric Dumazet int i, delta, len = from->len; 3404bad43ca8SEric Dumazet 3405bad43ca8SEric Dumazet *fragstolen = false; 3406bad43ca8SEric Dumazet 3407bad43ca8SEric Dumazet if (skb_cloned(to)) 3408bad43ca8SEric Dumazet return false; 3409bad43ca8SEric Dumazet 3410bad43ca8SEric Dumazet if (len <= skb_tailroom(to)) { 3411bad43ca8SEric Dumazet BUG_ON(skb_copy_bits(from, 0, skb_put(to, len), len)); 3412bad43ca8SEric Dumazet *delta_truesize = 0; 3413bad43ca8SEric Dumazet return true; 3414bad43ca8SEric Dumazet } 3415bad43ca8SEric Dumazet 3416bad43ca8SEric Dumazet if (skb_has_frag_list(to) || skb_has_frag_list(from)) 3417bad43ca8SEric Dumazet return false; 3418bad43ca8SEric Dumazet 3419bad43ca8SEric Dumazet if (skb_headlen(from) != 0) { 3420bad43ca8SEric Dumazet struct page *page; 3421bad43ca8SEric Dumazet unsigned int offset; 3422bad43ca8SEric Dumazet 3423bad43ca8SEric Dumazet if (skb_shinfo(to)->nr_frags + 3424bad43ca8SEric Dumazet skb_shinfo(from)->nr_frags >= MAX_SKB_FRAGS) 3425bad43ca8SEric Dumazet return false; 3426bad43ca8SEric Dumazet 3427bad43ca8SEric Dumazet if (skb_head_is_locked(from)) 3428bad43ca8SEric Dumazet return false; 3429bad43ca8SEric Dumazet 3430bad43ca8SEric Dumazet delta = from->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff)); 3431bad43ca8SEric Dumazet 3432bad43ca8SEric Dumazet page = virt_to_head_page(from->head); 3433bad43ca8SEric Dumazet offset = from->data - (unsigned char *)page_address(page); 3434bad43ca8SEric Dumazet 3435bad43ca8SEric Dumazet skb_fill_page_desc(to, skb_shinfo(to)->nr_frags, 3436bad43ca8SEric Dumazet page, offset, skb_headlen(from)); 3437bad43ca8SEric Dumazet *fragstolen = true; 3438bad43ca8SEric Dumazet } else { 3439bad43ca8SEric Dumazet if (skb_shinfo(to)->nr_frags + 3440bad43ca8SEric Dumazet skb_shinfo(from)->nr_frags > MAX_SKB_FRAGS) 3441bad43ca8SEric Dumazet return false; 3442bad43ca8SEric Dumazet 3443f4b549a5SWeiping Pan delta = from->truesize - SKB_TRUESIZE(skb_end_offset(from)); 3444bad43ca8SEric Dumazet } 3445bad43ca8SEric Dumazet 3446bad43ca8SEric Dumazet WARN_ON_ONCE(delta < len); 3447bad43ca8SEric Dumazet 3448bad43ca8SEric Dumazet memcpy(skb_shinfo(to)->frags + skb_shinfo(to)->nr_frags, 3449bad43ca8SEric Dumazet skb_shinfo(from)->frags, 3450bad43ca8SEric Dumazet skb_shinfo(from)->nr_frags * sizeof(skb_frag_t)); 3451bad43ca8SEric Dumazet skb_shinfo(to)->nr_frags += skb_shinfo(from)->nr_frags; 3452bad43ca8SEric Dumazet 3453bad43ca8SEric Dumazet if (!skb_cloned(from)) 3454bad43ca8SEric Dumazet skb_shinfo(from)->nr_frags = 0; 3455bad43ca8SEric Dumazet 34568ea853fdSLi RongQing /* if the skb is not cloned this does nothing 34578ea853fdSLi RongQing * since we set nr_frags to 0. 34588ea853fdSLi RongQing */ 3459bad43ca8SEric Dumazet for (i = 0; i < skb_shinfo(from)->nr_frags; i++) 3460bad43ca8SEric Dumazet skb_frag_ref(from, i); 3461bad43ca8SEric Dumazet 3462bad43ca8SEric Dumazet to->truesize += delta; 3463bad43ca8SEric Dumazet to->len += len; 3464bad43ca8SEric Dumazet to->data_len += len; 3465bad43ca8SEric Dumazet 3466bad43ca8SEric Dumazet *delta_truesize = delta; 3467bad43ca8SEric Dumazet return true; 3468bad43ca8SEric Dumazet } 3469bad43ca8SEric Dumazet EXPORT_SYMBOL(skb_try_coalesce); 3470