Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Routines having to do with the 'struct sk_buff' memory handlers. |
| 3 | * |
| 4 | * Authors: Alan Cox <iiitac@pyr.swan.ac.uk> |
| 5 | * Florian La Roche <rzsfl@rz.uni-sb.de> |
| 6 | * |
| 7 | * Version: $Id: skbuff.c,v 1.90 2001/11/07 05:56:19 davem Exp $ |
| 8 | * |
| 9 | * Fixes: |
| 10 | * Alan Cox : Fixed the worst of the load |
| 11 | * balancer bugs. |
| 12 | * Dave Platt : Interrupt stacking fix. |
| 13 | * Richard Kooijman : Timestamp fixes. |
| 14 | * Alan Cox : Changed buffer format. |
| 15 | * Alan Cox : destructor hook for AF_UNIX etc. |
| 16 | * Linus Torvalds : Better skb_clone. |
| 17 | * Alan Cox : Added skb_copy. |
| 18 | * Alan Cox : Added all the changed routines Linus |
| 19 | * only put in the headers |
| 20 | * Ray VanTassle : Fixed --skb->lock in free |
| 21 | * Alan Cox : skb_copy copy arp field |
| 22 | * Andi Kleen : slabified it. |
| 23 | * Robert Olsson : Removed skb_head_pool |
| 24 | * |
| 25 | * NOTE: |
| 26 | * The __skb_ routines should be called with interrupts |
| 27 | * disabled, or you better be *real* sure that the operation is atomic |
| 28 | * with respect to whatever list is being frobbed (e.g. via lock_sock() |
| 29 | * or via disabling bottom half handlers, etc). |
| 30 | * |
| 31 | * This program is free software; you can redistribute it and/or |
| 32 | * modify it under the terms of the GNU General Public License |
| 33 | * as published by the Free Software Foundation; either version |
| 34 | * 2 of the License, or (at your option) any later version. |
| 35 | */ |
| 36 | |
| 37 | /* |
| 38 | * The functions in this file will not compile correctly with gcc 2.4.x |
| 39 | */ |
| 40 | |
| 41 | #include <linux/config.h> |
| 42 | #include <linux/module.h> |
| 43 | #include <linux/types.h> |
| 44 | #include <linux/kernel.h> |
| 45 | #include <linux/sched.h> |
| 46 | #include <linux/mm.h> |
| 47 | #include <linux/interrupt.h> |
| 48 | #include <linux/in.h> |
| 49 | #include <linux/inet.h> |
| 50 | #include <linux/slab.h> |
| 51 | #include <linux/netdevice.h> |
| 52 | #ifdef CONFIG_NET_CLS_ACT |
| 53 | #include <net/pkt_sched.h> |
| 54 | #endif |
| 55 | #include <linux/string.h> |
| 56 | #include <linux/skbuff.h> |
| 57 | #include <linux/cache.h> |
| 58 | #include <linux/rtnetlink.h> |
| 59 | #include <linux/init.h> |
| 60 | #include <linux/highmem.h> |
| 61 | |
| 62 | #include <net/protocol.h> |
| 63 | #include <net/dst.h> |
| 64 | #include <net/sock.h> |
| 65 | #include <net/checksum.h> |
| 66 | #include <net/xfrm.h> |
| 67 | |
| 68 | #include <asm/uaccess.h> |
| 69 | #include <asm/system.h> |
| 70 | |
Eric Dumazet | ba89966 | 2005-08-26 12:05:31 -0700 | [diff] [blame] | 71 | static kmem_cache_t *skbuff_head_cache __read_mostly; |
| 72 | static kmem_cache_t *skbuff_fclone_cache __read_mostly; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | |
| 74 | /* |
| 75 | * Keep out-of-line to prevent kernel bloat. |
| 76 | * __builtin_return_address is not used because it is not always |
| 77 | * reliable. |
| 78 | */ |
| 79 | |
| 80 | /** |
| 81 | * skb_over_panic - private function |
| 82 | * @skb: buffer |
| 83 | * @sz: size |
| 84 | * @here: address |
| 85 | * |
| 86 | * Out of line support code for skb_put(). Not user callable. |
| 87 | */ |
| 88 | void skb_over_panic(struct sk_buff *skb, int sz, void *here) |
| 89 | { |
Patrick McHardy | 2609545 | 2005-04-21 16:43:02 -0700 | [diff] [blame] | 90 | printk(KERN_EMERG "skb_over_panic: text:%p len:%d put:%d head:%p " |
| 91 | "data:%p tail:%p end:%p dev:%s\n", |
| 92 | here, skb->len, sz, skb->head, skb->data, skb->tail, skb->end, |
| 93 | skb->dev ? skb->dev->name : "<NULL>"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | BUG(); |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * skb_under_panic - private function |
| 99 | * @skb: buffer |
| 100 | * @sz: size |
| 101 | * @here: address |
| 102 | * |
| 103 | * Out of line support code for skb_push(). Not user callable. |
| 104 | */ |
| 105 | |
| 106 | void skb_under_panic(struct sk_buff *skb, int sz, void *here) |
| 107 | { |
Patrick McHardy | 2609545 | 2005-04-21 16:43:02 -0700 | [diff] [blame] | 108 | printk(KERN_EMERG "skb_under_panic: text:%p len:%d put:%d head:%p " |
| 109 | "data:%p tail:%p end:%p dev:%s\n", |
| 110 | here, skb->len, sz, skb->head, skb->data, skb->tail, skb->end, |
| 111 | skb->dev ? skb->dev->name : "<NULL>"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | BUG(); |
| 113 | } |
| 114 | |
| 115 | /* Allocate a new skbuff. We do this ourselves so we can fill in a few |
| 116 | * 'private' fields and also do memory statistics to find all the |
| 117 | * [BEEP] leaks. |
| 118 | * |
| 119 | */ |
| 120 | |
| 121 | /** |
David S. Miller | d179cd1 | 2005-08-17 14:57:30 -0700 | [diff] [blame] | 122 | * __alloc_skb - allocate a network buffer |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | * @size: size to allocate |
| 124 | * @gfp_mask: allocation mask |
Randy Dunlap | c83c248 | 2005-10-18 22:07:41 -0700 | [diff] [blame] | 125 | * @fclone: allocate from fclone cache instead of head cache |
| 126 | * and allocate a cloned (child) skb |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | * |
| 128 | * Allocate a new &sk_buff. The returned buffer has no headroom and a |
| 129 | * tail room of size bytes. The object has a reference count of one. |
| 130 | * The return is the buffer. On a failure the return is %NULL. |
| 131 | * |
| 132 | * Buffers may only be allocated from interrupts using a @gfp_mask of |
| 133 | * %GFP_ATOMIC. |
| 134 | */ |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 135 | struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, |
David S. Miller | d179cd1 | 2005-08-17 14:57:30 -0700 | [diff] [blame] | 136 | int fclone) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | { |
Benjamin LaHaise | 4947d3e | 2006-01-03 14:06:50 -0800 | [diff] [blame] | 138 | struct skb_shared_info *shinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | struct sk_buff *skb; |
| 140 | u8 *data; |
| 141 | |
| 142 | /* Get the HEAD */ |
Benjamin LaHaise | 4947d3e | 2006-01-03 14:06:50 -0800 | [diff] [blame] | 143 | skb = kmem_cache_alloc(fclone ? skbuff_fclone_cache : skbuff_head_cache, |
| 144 | gfp_mask & ~__GFP_DMA); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | if (!skb) |
| 146 | goto out; |
| 147 | |
| 148 | /* Get the DATA. Size must match skb_add_mtu(). */ |
| 149 | size = SKB_DATA_ALIGN(size); |
| 150 | data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask); |
| 151 | if (!data) |
| 152 | goto nodata; |
| 153 | |
| 154 | memset(skb, 0, offsetof(struct sk_buff, truesize)); |
| 155 | skb->truesize = size + sizeof(struct sk_buff); |
| 156 | atomic_set(&skb->users, 1); |
| 157 | skb->head = data; |
| 158 | skb->data = data; |
| 159 | skb->tail = data; |
| 160 | skb->end = data + size; |
Benjamin LaHaise | 4947d3e | 2006-01-03 14:06:50 -0800 | [diff] [blame] | 161 | /* make sure we initialize shinfo sequentially */ |
| 162 | shinfo = skb_shinfo(skb); |
| 163 | atomic_set(&shinfo->dataref, 1); |
| 164 | shinfo->nr_frags = 0; |
| 165 | shinfo->tso_size = 0; |
| 166 | shinfo->tso_segs = 0; |
| 167 | shinfo->ufo_size = 0; |
| 168 | shinfo->ip6_frag_id = 0; |
| 169 | shinfo->frag_list = NULL; |
| 170 | |
David S. Miller | d179cd1 | 2005-08-17 14:57:30 -0700 | [diff] [blame] | 171 | if (fclone) { |
| 172 | struct sk_buff *child = skb + 1; |
| 173 | atomic_t *fclone_ref = (atomic_t *) (child + 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | |
David S. Miller | d179cd1 | 2005-08-17 14:57:30 -0700 | [diff] [blame] | 175 | skb->fclone = SKB_FCLONE_ORIG; |
| 176 | atomic_set(fclone_ref, 1); |
| 177 | |
| 178 | child->fclone = SKB_FCLONE_UNAVAILABLE; |
| 179 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | out: |
| 181 | return skb; |
| 182 | nodata: |
| 183 | kmem_cache_free(skbuff_head_cache, skb); |
| 184 | skb = NULL; |
| 185 | goto out; |
| 186 | } |
| 187 | |
| 188 | /** |
| 189 | * alloc_skb_from_cache - allocate a network buffer |
| 190 | * @cp: kmem_cache from which to allocate the data area |
| 191 | * (object size must be big enough for @size bytes + skb overheads) |
| 192 | * @size: size to allocate |
| 193 | * @gfp_mask: allocation mask |
| 194 | * |
| 195 | * Allocate a new &sk_buff. The returned buffer has no headroom and |
| 196 | * tail room of size bytes. The object has a reference count of one. |
| 197 | * The return is the buffer. On a failure the return is %NULL. |
| 198 | * |
| 199 | * Buffers may only be allocated from interrupts using a @gfp_mask of |
| 200 | * %GFP_ATOMIC. |
| 201 | */ |
| 202 | struct sk_buff *alloc_skb_from_cache(kmem_cache_t *cp, |
Victor Fusco | 86a76ca | 2005-07-08 14:57:47 -0700 | [diff] [blame] | 203 | unsigned int size, |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 204 | gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | { |
| 206 | struct sk_buff *skb; |
| 207 | u8 *data; |
| 208 | |
| 209 | /* Get the HEAD */ |
| 210 | skb = kmem_cache_alloc(skbuff_head_cache, |
| 211 | gfp_mask & ~__GFP_DMA); |
| 212 | if (!skb) |
| 213 | goto out; |
| 214 | |
| 215 | /* Get the DATA. */ |
| 216 | size = SKB_DATA_ALIGN(size); |
| 217 | data = kmem_cache_alloc(cp, gfp_mask); |
| 218 | if (!data) |
| 219 | goto nodata; |
| 220 | |
| 221 | memset(skb, 0, offsetof(struct sk_buff, truesize)); |
| 222 | skb->truesize = size + sizeof(struct sk_buff); |
| 223 | atomic_set(&skb->users, 1); |
| 224 | skb->head = data; |
| 225 | skb->data = data; |
| 226 | skb->tail = data; |
| 227 | skb->end = data + size; |
| 228 | |
| 229 | atomic_set(&(skb_shinfo(skb)->dataref), 1); |
| 230 | skb_shinfo(skb)->nr_frags = 0; |
| 231 | skb_shinfo(skb)->tso_size = 0; |
| 232 | skb_shinfo(skb)->tso_segs = 0; |
| 233 | skb_shinfo(skb)->frag_list = NULL; |
| 234 | out: |
| 235 | return skb; |
| 236 | nodata: |
| 237 | kmem_cache_free(skbuff_head_cache, skb); |
| 238 | skb = NULL; |
| 239 | goto out; |
| 240 | } |
| 241 | |
| 242 | |
| 243 | static void skb_drop_fraglist(struct sk_buff *skb) |
| 244 | { |
| 245 | struct sk_buff *list = skb_shinfo(skb)->frag_list; |
| 246 | |
| 247 | skb_shinfo(skb)->frag_list = NULL; |
| 248 | |
| 249 | do { |
| 250 | struct sk_buff *this = list; |
| 251 | list = list->next; |
| 252 | kfree_skb(this); |
| 253 | } while (list); |
| 254 | } |
| 255 | |
| 256 | static void skb_clone_fraglist(struct sk_buff *skb) |
| 257 | { |
| 258 | struct sk_buff *list; |
| 259 | |
| 260 | for (list = skb_shinfo(skb)->frag_list; list; list = list->next) |
| 261 | skb_get(list); |
| 262 | } |
| 263 | |
| 264 | void skb_release_data(struct sk_buff *skb) |
| 265 | { |
| 266 | if (!skb->cloned || |
| 267 | !atomic_sub_return(skb->nohdr ? (1 << SKB_DATAREF_SHIFT) + 1 : 1, |
| 268 | &skb_shinfo(skb)->dataref)) { |
| 269 | if (skb_shinfo(skb)->nr_frags) { |
| 270 | int i; |
| 271 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) |
| 272 | put_page(skb_shinfo(skb)->frags[i].page); |
| 273 | } |
| 274 | |
| 275 | if (skb_shinfo(skb)->frag_list) |
| 276 | skb_drop_fraglist(skb); |
| 277 | |
| 278 | kfree(skb->head); |
| 279 | } |
| 280 | } |
| 281 | |
| 282 | /* |
| 283 | * Free an skbuff by memory without cleaning the state. |
| 284 | */ |
| 285 | void kfree_skbmem(struct sk_buff *skb) |
| 286 | { |
David S. Miller | d179cd1 | 2005-08-17 14:57:30 -0700 | [diff] [blame] | 287 | struct sk_buff *other; |
| 288 | atomic_t *fclone_ref; |
| 289 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 290 | skb_release_data(skb); |
David S. Miller | d179cd1 | 2005-08-17 14:57:30 -0700 | [diff] [blame] | 291 | switch (skb->fclone) { |
| 292 | case SKB_FCLONE_UNAVAILABLE: |
| 293 | kmem_cache_free(skbuff_head_cache, skb); |
| 294 | break; |
| 295 | |
| 296 | case SKB_FCLONE_ORIG: |
| 297 | fclone_ref = (atomic_t *) (skb + 2); |
| 298 | if (atomic_dec_and_test(fclone_ref)) |
| 299 | kmem_cache_free(skbuff_fclone_cache, skb); |
| 300 | break; |
| 301 | |
| 302 | case SKB_FCLONE_CLONE: |
| 303 | fclone_ref = (atomic_t *) (skb + 1); |
| 304 | other = skb - 1; |
| 305 | |
| 306 | /* The clone portion is available for |
| 307 | * fast-cloning again. |
| 308 | */ |
| 309 | skb->fclone = SKB_FCLONE_UNAVAILABLE; |
| 310 | |
| 311 | if (atomic_dec_and_test(fclone_ref)) |
| 312 | kmem_cache_free(skbuff_fclone_cache, other); |
| 313 | break; |
| 314 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | } |
| 316 | |
| 317 | /** |
| 318 | * __kfree_skb - private function |
| 319 | * @skb: buffer |
| 320 | * |
| 321 | * Free an sk_buff. Release anything attached to the buffer. |
| 322 | * Clean the state. This is an internal helper function. Users should |
| 323 | * always call kfree_skb |
| 324 | */ |
| 325 | |
| 326 | void __kfree_skb(struct sk_buff *skb) |
| 327 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 328 | dst_release(skb->dst); |
| 329 | #ifdef CONFIG_XFRM |
| 330 | secpath_put(skb->sp); |
| 331 | #endif |
Stephen Hemminger | 9c2b332 | 2005-04-19 22:39:42 -0700 | [diff] [blame] | 332 | if (skb->destructor) { |
| 333 | WARN_ON(in_irq()); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 334 | skb->destructor(skb); |
| 335 | } |
| 336 | #ifdef CONFIG_NETFILTER |
| 337 | nf_conntrack_put(skb->nfct); |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 338 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
| 339 | nf_conntrack_put_reasm(skb->nfct_reasm); |
| 340 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | #ifdef CONFIG_BRIDGE_NETFILTER |
| 342 | nf_bridge_put(skb->nf_bridge); |
| 343 | #endif |
| 344 | #endif |
| 345 | /* XXX: IS this still necessary? - JHS */ |
| 346 | #ifdef CONFIG_NET_SCHED |
| 347 | skb->tc_index = 0; |
| 348 | #ifdef CONFIG_NET_CLS_ACT |
| 349 | skb->tc_verd = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | #endif |
| 351 | #endif |
| 352 | |
| 353 | kfree_skbmem(skb); |
| 354 | } |
| 355 | |
| 356 | /** |
| 357 | * skb_clone - duplicate an sk_buff |
| 358 | * @skb: buffer to clone |
| 359 | * @gfp_mask: allocation priority |
| 360 | * |
| 361 | * Duplicate an &sk_buff. The new one is not owned by a socket. Both |
| 362 | * copies share the same packet data but not structure. The new |
| 363 | * buffer has a reference count of 1. If the allocation fails the |
| 364 | * function returns %NULL otherwise the new buffer is returned. |
| 365 | * |
| 366 | * If this function is called from an interrupt gfp_mask() must be |
| 367 | * %GFP_ATOMIC. |
| 368 | */ |
| 369 | |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 370 | struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 371 | { |
David S. Miller | d179cd1 | 2005-08-17 14:57:30 -0700 | [diff] [blame] | 372 | struct sk_buff *n; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 373 | |
David S. Miller | d179cd1 | 2005-08-17 14:57:30 -0700 | [diff] [blame] | 374 | n = skb + 1; |
| 375 | if (skb->fclone == SKB_FCLONE_ORIG && |
| 376 | n->fclone == SKB_FCLONE_UNAVAILABLE) { |
| 377 | atomic_t *fclone_ref = (atomic_t *) (n + 1); |
| 378 | n->fclone = SKB_FCLONE_CLONE; |
| 379 | atomic_inc(fclone_ref); |
| 380 | } else { |
| 381 | n = kmem_cache_alloc(skbuff_head_cache, gfp_mask); |
| 382 | if (!n) |
| 383 | return NULL; |
| 384 | n->fclone = SKB_FCLONE_UNAVAILABLE; |
| 385 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 386 | |
| 387 | #define C(x) n->x = skb->x |
| 388 | |
| 389 | n->next = n->prev = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | n->sk = NULL; |
Patrick McHardy | a61bbcf | 2005-08-14 17:24:31 -0700 | [diff] [blame] | 391 | C(tstamp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | C(dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 393 | C(h); |
| 394 | C(nh); |
| 395 | C(mac); |
| 396 | C(dst); |
| 397 | dst_clone(skb->dst); |
| 398 | C(sp); |
| 399 | #ifdef CONFIG_INET |
| 400 | secpath_get(skb->sp); |
| 401 | #endif |
| 402 | memcpy(n->cb, skb->cb, sizeof(skb->cb)); |
| 403 | C(len); |
| 404 | C(data_len); |
| 405 | C(csum); |
| 406 | C(local_df); |
| 407 | n->cloned = 1; |
| 408 | n->nohdr = 0; |
| 409 | C(pkt_type); |
| 410 | C(ip_summed); |
| 411 | C(priority); |
| 412 | C(protocol); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | n->destructor = NULL; |
| 414 | #ifdef CONFIG_NETFILTER |
| 415 | C(nfmark); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 416 | C(nfct); |
| 417 | nf_conntrack_get(skb->nfct); |
| 418 | C(nfctinfo); |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 419 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
| 420 | C(nfct_reasm); |
| 421 | nf_conntrack_get_reasm(skb->nfct_reasm); |
| 422 | #endif |
Julian Anastasov | c98d80e | 2005-10-22 13:39:21 +0300 | [diff] [blame] | 423 | #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) |
| 424 | C(ipvs_property); |
| 425 | #endif |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 426 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
| 427 | C(nfct_reasm); |
| 428 | nf_conntrack_get_reasm(skb->nfct_reasm); |
| 429 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | #ifdef CONFIG_BRIDGE_NETFILTER |
| 431 | C(nf_bridge); |
| 432 | nf_bridge_get(skb->nf_bridge); |
| 433 | #endif |
| 434 | #endif /*CONFIG_NETFILTER*/ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | #ifdef CONFIG_NET_SCHED |
| 436 | C(tc_index); |
| 437 | #ifdef CONFIG_NET_CLS_ACT |
| 438 | n->tc_verd = SET_TC_VERD(skb->tc_verd,0); |
David S. Miller | b72f6ec | 2005-07-19 14:13:54 -0700 | [diff] [blame] | 439 | n->tc_verd = CLR_TC_OK2MUNGE(n->tc_verd); |
| 440 | n->tc_verd = CLR_TC_MUNGED(n->tc_verd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 441 | C(input_dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | #endif |
| 443 | |
| 444 | #endif |
| 445 | C(truesize); |
| 446 | atomic_set(&n->users, 1); |
| 447 | C(head); |
| 448 | C(data); |
| 449 | C(tail); |
| 450 | C(end); |
| 451 | |
| 452 | atomic_inc(&(skb_shinfo(skb)->dataref)); |
| 453 | skb->cloned = 1; |
| 454 | |
| 455 | return n; |
| 456 | } |
| 457 | |
| 458 | static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old) |
| 459 | { |
| 460 | /* |
| 461 | * Shift between the two data areas in bytes |
| 462 | */ |
| 463 | unsigned long offset = new->data - old->data; |
| 464 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | new->sk = NULL; |
| 466 | new->dev = old->dev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | new->priority = old->priority; |
| 468 | new->protocol = old->protocol; |
| 469 | new->dst = dst_clone(old->dst); |
| 470 | #ifdef CONFIG_INET |
| 471 | new->sp = secpath_get(old->sp); |
| 472 | #endif |
| 473 | new->h.raw = old->h.raw + offset; |
| 474 | new->nh.raw = old->nh.raw + offset; |
| 475 | new->mac.raw = old->mac.raw + offset; |
| 476 | memcpy(new->cb, old->cb, sizeof(old->cb)); |
| 477 | new->local_df = old->local_df; |
David S. Miller | d179cd1 | 2005-08-17 14:57:30 -0700 | [diff] [blame] | 478 | new->fclone = SKB_FCLONE_UNAVAILABLE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | new->pkt_type = old->pkt_type; |
Patrick McHardy | a61bbcf | 2005-08-14 17:24:31 -0700 | [diff] [blame] | 480 | new->tstamp = old->tstamp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | new->destructor = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | #ifdef CONFIG_NETFILTER |
| 483 | new->nfmark = old->nfmark; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | new->nfct = old->nfct; |
| 485 | nf_conntrack_get(old->nfct); |
| 486 | new->nfctinfo = old->nfctinfo; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 487 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
| 488 | new->nfct_reasm = old->nfct_reasm; |
| 489 | nf_conntrack_get_reasm(old->nfct_reasm); |
| 490 | #endif |
Julian Anastasov | c98d80e | 2005-10-22 13:39:21 +0300 | [diff] [blame] | 491 | #if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE) |
| 492 | new->ipvs_property = old->ipvs_property; |
| 493 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 494 | #ifdef CONFIG_BRIDGE_NETFILTER |
| 495 | new->nf_bridge = old->nf_bridge; |
| 496 | nf_bridge_get(old->nf_bridge); |
| 497 | #endif |
| 498 | #endif |
| 499 | #ifdef CONFIG_NET_SCHED |
| 500 | #ifdef CONFIG_NET_CLS_ACT |
| 501 | new->tc_verd = old->tc_verd; |
| 502 | #endif |
| 503 | new->tc_index = old->tc_index; |
| 504 | #endif |
| 505 | atomic_set(&new->users, 1); |
| 506 | skb_shinfo(new)->tso_size = skb_shinfo(old)->tso_size; |
| 507 | skb_shinfo(new)->tso_segs = skb_shinfo(old)->tso_segs; |
| 508 | } |
| 509 | |
| 510 | /** |
| 511 | * skb_copy - create private copy of an sk_buff |
| 512 | * @skb: buffer to copy |
| 513 | * @gfp_mask: allocation priority |
| 514 | * |
| 515 | * Make a copy of both an &sk_buff and its data. This is used when the |
| 516 | * caller wishes to modify the data and needs a private copy of the |
| 517 | * data to alter. Returns %NULL on failure or the pointer to the buffer |
| 518 | * on success. The returned buffer has a reference count of 1. |
| 519 | * |
| 520 | * As by-product this function converts non-linear &sk_buff to linear |
| 521 | * one, so that &sk_buff becomes completely private and caller is allowed |
| 522 | * to modify all the data of returned buffer. This means that this |
| 523 | * function is not recommended for use in circumstances when only |
| 524 | * header is going to be modified. Use pskb_copy() instead. |
| 525 | */ |
| 526 | |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 527 | struct sk_buff *skb_copy(const struct sk_buff *skb, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 528 | { |
| 529 | int headerlen = skb->data - skb->head; |
| 530 | /* |
| 531 | * Allocate the copy buffer |
| 532 | */ |
| 533 | struct sk_buff *n = alloc_skb(skb->end - skb->head + skb->data_len, |
| 534 | gfp_mask); |
| 535 | if (!n) |
| 536 | return NULL; |
| 537 | |
| 538 | /* Set the data pointer */ |
| 539 | skb_reserve(n, headerlen); |
| 540 | /* Set the tail pointer and length */ |
| 541 | skb_put(n, skb->len); |
| 542 | n->csum = skb->csum; |
| 543 | n->ip_summed = skb->ip_summed; |
| 544 | |
| 545 | if (skb_copy_bits(skb, -headerlen, n->head, headerlen + skb->len)) |
| 546 | BUG(); |
| 547 | |
| 548 | copy_skb_header(n, skb); |
| 549 | return n; |
| 550 | } |
| 551 | |
| 552 | |
| 553 | /** |
| 554 | * pskb_copy - create copy of an sk_buff with private head. |
| 555 | * @skb: buffer to copy |
| 556 | * @gfp_mask: allocation priority |
| 557 | * |
| 558 | * Make a copy of both an &sk_buff and part of its data, located |
| 559 | * in header. Fragmented data remain shared. This is used when |
| 560 | * the caller wishes to modify only header of &sk_buff and needs |
| 561 | * private copy of the header to alter. Returns %NULL on failure |
| 562 | * or the pointer to the buffer on success. |
| 563 | * The returned buffer has a reference count of 1. |
| 564 | */ |
| 565 | |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 566 | struct sk_buff *pskb_copy(struct sk_buff *skb, gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | { |
| 568 | /* |
| 569 | * Allocate the copy buffer |
| 570 | */ |
| 571 | struct sk_buff *n = alloc_skb(skb->end - skb->head, gfp_mask); |
| 572 | |
| 573 | if (!n) |
| 574 | goto out; |
| 575 | |
| 576 | /* Set the data pointer */ |
| 577 | skb_reserve(n, skb->data - skb->head); |
| 578 | /* Set the tail pointer and length */ |
| 579 | skb_put(n, skb_headlen(skb)); |
| 580 | /* Copy the bytes */ |
| 581 | memcpy(n->data, skb->data, n->len); |
| 582 | n->csum = skb->csum; |
| 583 | n->ip_summed = skb->ip_summed; |
| 584 | |
| 585 | n->data_len = skb->data_len; |
| 586 | n->len = skb->len; |
| 587 | |
| 588 | if (skb_shinfo(skb)->nr_frags) { |
| 589 | int i; |
| 590 | |
| 591 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
| 592 | skb_shinfo(n)->frags[i] = skb_shinfo(skb)->frags[i]; |
| 593 | get_page(skb_shinfo(n)->frags[i].page); |
| 594 | } |
| 595 | skb_shinfo(n)->nr_frags = i; |
| 596 | } |
| 597 | |
| 598 | if (skb_shinfo(skb)->frag_list) { |
| 599 | skb_shinfo(n)->frag_list = skb_shinfo(skb)->frag_list; |
| 600 | skb_clone_fraglist(n); |
| 601 | } |
| 602 | |
| 603 | copy_skb_header(n, skb); |
| 604 | out: |
| 605 | return n; |
| 606 | } |
| 607 | |
| 608 | /** |
| 609 | * pskb_expand_head - reallocate header of &sk_buff |
| 610 | * @skb: buffer to reallocate |
| 611 | * @nhead: room to add at head |
| 612 | * @ntail: room to add at tail |
| 613 | * @gfp_mask: allocation priority |
| 614 | * |
| 615 | * Expands (or creates identical copy, if &nhead and &ntail are zero) |
| 616 | * header of skb. &sk_buff itself is not changed. &sk_buff MUST have |
| 617 | * reference count of 1. Returns zero in the case of success or error, |
| 618 | * if expansion failed. In the last case, &sk_buff is not changed. |
| 619 | * |
| 620 | * All the pointers pointing into skb header may change and must be |
| 621 | * reloaded after call to this function. |
| 622 | */ |
| 623 | |
Victor Fusco | 86a76ca | 2005-07-08 14:57:47 -0700 | [diff] [blame] | 624 | int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 625 | gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 626 | { |
| 627 | int i; |
| 628 | u8 *data; |
| 629 | int size = nhead + (skb->end - skb->head) + ntail; |
| 630 | long off; |
| 631 | |
| 632 | if (skb_shared(skb)) |
| 633 | BUG(); |
| 634 | |
| 635 | size = SKB_DATA_ALIGN(size); |
| 636 | |
| 637 | data = kmalloc(size + sizeof(struct skb_shared_info), gfp_mask); |
| 638 | if (!data) |
| 639 | goto nodata; |
| 640 | |
| 641 | /* Copy only real data... and, alas, header. This should be |
| 642 | * optimized for the cases when header is void. */ |
| 643 | memcpy(data + nhead, skb->head, skb->tail - skb->head); |
| 644 | memcpy(data + size, skb->end, sizeof(struct skb_shared_info)); |
| 645 | |
| 646 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) |
| 647 | get_page(skb_shinfo(skb)->frags[i].page); |
| 648 | |
| 649 | if (skb_shinfo(skb)->frag_list) |
| 650 | skb_clone_fraglist(skb); |
| 651 | |
| 652 | skb_release_data(skb); |
| 653 | |
| 654 | off = (data + nhead) - skb->head; |
| 655 | |
| 656 | skb->head = data; |
| 657 | skb->end = data + size; |
| 658 | skb->data += off; |
| 659 | skb->tail += off; |
| 660 | skb->mac.raw += off; |
| 661 | skb->h.raw += off; |
| 662 | skb->nh.raw += off; |
| 663 | skb->cloned = 0; |
| 664 | skb->nohdr = 0; |
| 665 | atomic_set(&skb_shinfo(skb)->dataref, 1); |
| 666 | return 0; |
| 667 | |
| 668 | nodata: |
| 669 | return -ENOMEM; |
| 670 | } |
| 671 | |
| 672 | /* Make private copy of skb with writable head and some headroom */ |
| 673 | |
| 674 | struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, unsigned int headroom) |
| 675 | { |
| 676 | struct sk_buff *skb2; |
| 677 | int delta = headroom - skb_headroom(skb); |
| 678 | |
| 679 | if (delta <= 0) |
| 680 | skb2 = pskb_copy(skb, GFP_ATOMIC); |
| 681 | else { |
| 682 | skb2 = skb_clone(skb, GFP_ATOMIC); |
| 683 | if (skb2 && pskb_expand_head(skb2, SKB_DATA_ALIGN(delta), 0, |
| 684 | GFP_ATOMIC)) { |
| 685 | kfree_skb(skb2); |
| 686 | skb2 = NULL; |
| 687 | } |
| 688 | } |
| 689 | return skb2; |
| 690 | } |
| 691 | |
| 692 | |
| 693 | /** |
| 694 | * skb_copy_expand - copy and expand sk_buff |
| 695 | * @skb: buffer to copy |
| 696 | * @newheadroom: new free bytes at head |
| 697 | * @newtailroom: new free bytes at tail |
| 698 | * @gfp_mask: allocation priority |
| 699 | * |
| 700 | * Make a copy of both an &sk_buff and its data and while doing so |
| 701 | * allocate additional space. |
| 702 | * |
| 703 | * This is used when the caller wishes to modify the data and needs a |
| 704 | * private copy of the data to alter as well as more space for new fields. |
| 705 | * Returns %NULL on failure or the pointer to the buffer |
| 706 | * on success. The returned buffer has a reference count of 1. |
| 707 | * |
| 708 | * You must pass %GFP_ATOMIC as the allocation priority if this function |
| 709 | * is called from an interrupt. |
| 710 | * |
| 711 | * BUG ALERT: ip_summed is not copied. Why does this work? Is it used |
| 712 | * only by netfilter in the cases when checksum is recalculated? --ANK |
| 713 | */ |
| 714 | struct sk_buff *skb_copy_expand(const struct sk_buff *skb, |
Victor Fusco | 86a76ca | 2005-07-08 14:57:47 -0700 | [diff] [blame] | 715 | int newheadroom, int newtailroom, |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 716 | gfp_t gfp_mask) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | { |
| 718 | /* |
| 719 | * Allocate the copy buffer |
| 720 | */ |
| 721 | struct sk_buff *n = alloc_skb(newheadroom + skb->len + newtailroom, |
| 722 | gfp_mask); |
| 723 | int head_copy_len, head_copy_off; |
| 724 | |
| 725 | if (!n) |
| 726 | return NULL; |
| 727 | |
| 728 | skb_reserve(n, newheadroom); |
| 729 | |
| 730 | /* Set the tail pointer and length */ |
| 731 | skb_put(n, skb->len); |
| 732 | |
| 733 | head_copy_len = skb_headroom(skb); |
| 734 | head_copy_off = 0; |
| 735 | if (newheadroom <= head_copy_len) |
| 736 | head_copy_len = newheadroom; |
| 737 | else |
| 738 | head_copy_off = newheadroom - head_copy_len; |
| 739 | |
| 740 | /* Copy the linear header and data. */ |
| 741 | if (skb_copy_bits(skb, -head_copy_len, n->head + head_copy_off, |
| 742 | skb->len + head_copy_len)) |
| 743 | BUG(); |
| 744 | |
| 745 | copy_skb_header(n, skb); |
| 746 | |
| 747 | return n; |
| 748 | } |
| 749 | |
| 750 | /** |
| 751 | * skb_pad - zero pad the tail of an skb |
| 752 | * @skb: buffer to pad |
| 753 | * @pad: space to pad |
| 754 | * |
| 755 | * Ensure that a buffer is followed by a padding area that is zero |
| 756 | * filled. Used by network drivers which may DMA or transfer data |
| 757 | * beyond the buffer end onto the wire. |
| 758 | * |
| 759 | * May return NULL in out of memory cases. |
| 760 | */ |
| 761 | |
| 762 | struct sk_buff *skb_pad(struct sk_buff *skb, int pad) |
| 763 | { |
| 764 | struct sk_buff *nskb; |
| 765 | |
| 766 | /* If the skbuff is non linear tailroom is always zero.. */ |
| 767 | if (skb_tailroom(skb) >= pad) { |
| 768 | memset(skb->data+skb->len, 0, pad); |
| 769 | return skb; |
| 770 | } |
| 771 | |
| 772 | nskb = skb_copy_expand(skb, skb_headroom(skb), skb_tailroom(skb) + pad, GFP_ATOMIC); |
| 773 | kfree_skb(skb); |
| 774 | if (nskb) |
| 775 | memset(nskb->data+nskb->len, 0, pad); |
| 776 | return nskb; |
| 777 | } |
| 778 | |
| 779 | /* Trims skb to length len. It can change skb pointers, if "realloc" is 1. |
| 780 | * If realloc==0 and trimming is impossible without change of data, |
| 781 | * it is BUG(). |
| 782 | */ |
| 783 | |
| 784 | int ___pskb_trim(struct sk_buff *skb, unsigned int len, int realloc) |
| 785 | { |
| 786 | int offset = skb_headlen(skb); |
| 787 | int nfrags = skb_shinfo(skb)->nr_frags; |
| 788 | int i; |
| 789 | |
| 790 | for (i = 0; i < nfrags; i++) { |
| 791 | int end = offset + skb_shinfo(skb)->frags[i].size; |
| 792 | if (end > len) { |
| 793 | if (skb_cloned(skb)) { |
Kris Katterjohn | 09a6266 | 2006-01-08 22:24:28 -0800 | [diff] [blame] | 794 | BUG_ON(!realloc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) |
| 796 | return -ENOMEM; |
| 797 | } |
| 798 | if (len <= offset) { |
| 799 | put_page(skb_shinfo(skb)->frags[i].page); |
| 800 | skb_shinfo(skb)->nr_frags--; |
| 801 | } else { |
| 802 | skb_shinfo(skb)->frags[i].size = len - offset; |
| 803 | } |
| 804 | } |
| 805 | offset = end; |
| 806 | } |
| 807 | |
| 808 | if (offset < len) { |
| 809 | skb->data_len -= skb->len - len; |
| 810 | skb->len = len; |
| 811 | } else { |
| 812 | if (len <= skb_headlen(skb)) { |
| 813 | skb->len = len; |
| 814 | skb->data_len = 0; |
| 815 | skb->tail = skb->data + len; |
| 816 | if (skb_shinfo(skb)->frag_list && !skb_cloned(skb)) |
| 817 | skb_drop_fraglist(skb); |
| 818 | } else { |
| 819 | skb->data_len -= skb->len - len; |
| 820 | skb->len = len; |
| 821 | } |
| 822 | } |
| 823 | |
| 824 | return 0; |
| 825 | } |
| 826 | |
| 827 | /** |
| 828 | * __pskb_pull_tail - advance tail of skb header |
| 829 | * @skb: buffer to reallocate |
| 830 | * @delta: number of bytes to advance tail |
| 831 | * |
| 832 | * The function makes a sense only on a fragmented &sk_buff, |
| 833 | * it expands header moving its tail forward and copying necessary |
| 834 | * data from fragmented part. |
| 835 | * |
| 836 | * &sk_buff MUST have reference count of 1. |
| 837 | * |
| 838 | * Returns %NULL (and &sk_buff does not change) if pull failed |
| 839 | * or value of new tail of skb in the case of success. |
| 840 | * |
| 841 | * All the pointers pointing into skb header may change and must be |
| 842 | * reloaded after call to this function. |
| 843 | */ |
| 844 | |
| 845 | /* Moves tail of skb head forward, copying data from fragmented part, |
| 846 | * when it is necessary. |
| 847 | * 1. It may fail due to malloc failure. |
| 848 | * 2. It may change skb pointers. |
| 849 | * |
| 850 | * It is pretty complicated. Luckily, it is called only in exceptional cases. |
| 851 | */ |
| 852 | unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta) |
| 853 | { |
| 854 | /* If skb has not enough free space at tail, get new one |
| 855 | * plus 128 bytes for future expansions. If we have enough |
| 856 | * room at tail, reallocate without expansion only if skb is cloned. |
| 857 | */ |
| 858 | int i, k, eat = (skb->tail + delta) - skb->end; |
| 859 | |
| 860 | if (eat > 0 || skb_cloned(skb)) { |
| 861 | if (pskb_expand_head(skb, 0, eat > 0 ? eat + 128 : 0, |
| 862 | GFP_ATOMIC)) |
| 863 | return NULL; |
| 864 | } |
| 865 | |
| 866 | if (skb_copy_bits(skb, skb_headlen(skb), skb->tail, delta)) |
| 867 | BUG(); |
| 868 | |
| 869 | /* Optimization: no fragments, no reasons to preestimate |
| 870 | * size of pulled pages. Superb. |
| 871 | */ |
| 872 | if (!skb_shinfo(skb)->frag_list) |
| 873 | goto pull_pages; |
| 874 | |
| 875 | /* Estimate size of pulled pages. */ |
| 876 | eat = delta; |
| 877 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
| 878 | if (skb_shinfo(skb)->frags[i].size >= eat) |
| 879 | goto pull_pages; |
| 880 | eat -= skb_shinfo(skb)->frags[i].size; |
| 881 | } |
| 882 | |
| 883 | /* If we need update frag list, we are in troubles. |
| 884 | * Certainly, it possible to add an offset to skb data, |
| 885 | * but taking into account that pulling is expected to |
| 886 | * be very rare operation, it is worth to fight against |
| 887 | * further bloating skb head and crucify ourselves here instead. |
| 888 | * Pure masohism, indeed. 8)8) |
| 889 | */ |
| 890 | if (eat) { |
| 891 | struct sk_buff *list = skb_shinfo(skb)->frag_list; |
| 892 | struct sk_buff *clone = NULL; |
| 893 | struct sk_buff *insp = NULL; |
| 894 | |
| 895 | do { |
Kris Katterjohn | 09a6266 | 2006-01-08 22:24:28 -0800 | [diff] [blame] | 896 | BUG_ON(!list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 897 | |
| 898 | if (list->len <= eat) { |
| 899 | /* Eaten as whole. */ |
| 900 | eat -= list->len; |
| 901 | list = list->next; |
| 902 | insp = list; |
| 903 | } else { |
| 904 | /* Eaten partially. */ |
| 905 | |
| 906 | if (skb_shared(list)) { |
| 907 | /* Sucks! We need to fork list. :-( */ |
| 908 | clone = skb_clone(list, GFP_ATOMIC); |
| 909 | if (!clone) |
| 910 | return NULL; |
| 911 | insp = list->next; |
| 912 | list = clone; |
| 913 | } else { |
| 914 | /* This may be pulled without |
| 915 | * problems. */ |
| 916 | insp = list; |
| 917 | } |
| 918 | if (!pskb_pull(list, eat)) { |
| 919 | if (clone) |
| 920 | kfree_skb(clone); |
| 921 | return NULL; |
| 922 | } |
| 923 | break; |
| 924 | } |
| 925 | } while (eat); |
| 926 | |
| 927 | /* Free pulled out fragments. */ |
| 928 | while ((list = skb_shinfo(skb)->frag_list) != insp) { |
| 929 | skb_shinfo(skb)->frag_list = list->next; |
| 930 | kfree_skb(list); |
| 931 | } |
| 932 | /* And insert new clone at head. */ |
| 933 | if (clone) { |
| 934 | clone->next = list; |
| 935 | skb_shinfo(skb)->frag_list = clone; |
| 936 | } |
| 937 | } |
| 938 | /* Success! Now we may commit changes to skb data. */ |
| 939 | |
| 940 | pull_pages: |
| 941 | eat = delta; |
| 942 | k = 0; |
| 943 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
| 944 | if (skb_shinfo(skb)->frags[i].size <= eat) { |
| 945 | put_page(skb_shinfo(skb)->frags[i].page); |
| 946 | eat -= skb_shinfo(skb)->frags[i].size; |
| 947 | } else { |
| 948 | skb_shinfo(skb)->frags[k] = skb_shinfo(skb)->frags[i]; |
| 949 | if (eat) { |
| 950 | skb_shinfo(skb)->frags[k].page_offset += eat; |
| 951 | skb_shinfo(skb)->frags[k].size -= eat; |
| 952 | eat = 0; |
| 953 | } |
| 954 | k++; |
| 955 | } |
| 956 | } |
| 957 | skb_shinfo(skb)->nr_frags = k; |
| 958 | |
| 959 | skb->tail += delta; |
| 960 | skb->data_len -= delta; |
| 961 | |
| 962 | return skb->tail; |
| 963 | } |
| 964 | |
| 965 | /* Copy some data bits from skb to kernel buffer. */ |
| 966 | |
| 967 | int skb_copy_bits(const struct sk_buff *skb, int offset, void *to, int len) |
| 968 | { |
| 969 | int i, copy; |
| 970 | int start = skb_headlen(skb); |
| 971 | |
| 972 | if (offset > (int)skb->len - len) |
| 973 | goto fault; |
| 974 | |
| 975 | /* Copy header. */ |
| 976 | if ((copy = start - offset) > 0) { |
| 977 | if (copy > len) |
| 978 | copy = len; |
| 979 | memcpy(to, skb->data + offset, copy); |
| 980 | if ((len -= copy) == 0) |
| 981 | return 0; |
| 982 | offset += copy; |
| 983 | to += copy; |
| 984 | } |
| 985 | |
| 986 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
| 987 | int end; |
| 988 | |
| 989 | BUG_TRAP(start <= offset + len); |
| 990 | |
| 991 | end = start + skb_shinfo(skb)->frags[i].size; |
| 992 | if ((copy = end - offset) > 0) { |
| 993 | u8 *vaddr; |
| 994 | |
| 995 | if (copy > len) |
| 996 | copy = len; |
| 997 | |
| 998 | vaddr = kmap_skb_frag(&skb_shinfo(skb)->frags[i]); |
| 999 | memcpy(to, |
| 1000 | vaddr + skb_shinfo(skb)->frags[i].page_offset+ |
| 1001 | offset - start, copy); |
| 1002 | kunmap_skb_frag(vaddr); |
| 1003 | |
| 1004 | if ((len -= copy) == 0) |
| 1005 | return 0; |
| 1006 | offset += copy; |
| 1007 | to += copy; |
| 1008 | } |
| 1009 | start = end; |
| 1010 | } |
| 1011 | |
| 1012 | if (skb_shinfo(skb)->frag_list) { |
| 1013 | struct sk_buff *list = skb_shinfo(skb)->frag_list; |
| 1014 | |
| 1015 | for (; list; list = list->next) { |
| 1016 | int end; |
| 1017 | |
| 1018 | BUG_TRAP(start <= offset + len); |
| 1019 | |
| 1020 | end = start + list->len; |
| 1021 | if ((copy = end - offset) > 0) { |
| 1022 | if (copy > len) |
| 1023 | copy = len; |
| 1024 | if (skb_copy_bits(list, offset - start, |
| 1025 | to, copy)) |
| 1026 | goto fault; |
| 1027 | if ((len -= copy) == 0) |
| 1028 | return 0; |
| 1029 | offset += copy; |
| 1030 | to += copy; |
| 1031 | } |
| 1032 | start = end; |
| 1033 | } |
| 1034 | } |
| 1035 | if (!len) |
| 1036 | return 0; |
| 1037 | |
| 1038 | fault: |
| 1039 | return -EFAULT; |
| 1040 | } |
| 1041 | |
Herbert Xu | 357b40a | 2005-04-19 22:30:14 -0700 | [diff] [blame] | 1042 | /** |
| 1043 | * skb_store_bits - store bits from kernel buffer to skb |
| 1044 | * @skb: destination buffer |
| 1045 | * @offset: offset in destination |
| 1046 | * @from: source buffer |
| 1047 | * @len: number of bytes to copy |
| 1048 | * |
| 1049 | * Copy the specified number of bytes from the source buffer to the |
| 1050 | * destination skb. This function handles all the messy bits of |
| 1051 | * traversing fragment lists and such. |
| 1052 | */ |
| 1053 | |
| 1054 | int skb_store_bits(const struct sk_buff *skb, int offset, void *from, int len) |
| 1055 | { |
| 1056 | int i, copy; |
| 1057 | int start = skb_headlen(skb); |
| 1058 | |
| 1059 | if (offset > (int)skb->len - len) |
| 1060 | goto fault; |
| 1061 | |
| 1062 | if ((copy = start - offset) > 0) { |
| 1063 | if (copy > len) |
| 1064 | copy = len; |
| 1065 | memcpy(skb->data + offset, from, copy); |
| 1066 | if ((len -= copy) == 0) |
| 1067 | return 0; |
| 1068 | offset += copy; |
| 1069 | from += copy; |
| 1070 | } |
| 1071 | |
| 1072 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
| 1073 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; |
| 1074 | int end; |
| 1075 | |
| 1076 | BUG_TRAP(start <= offset + len); |
| 1077 | |
| 1078 | end = start + frag->size; |
| 1079 | if ((copy = end - offset) > 0) { |
| 1080 | u8 *vaddr; |
| 1081 | |
| 1082 | if (copy > len) |
| 1083 | copy = len; |
| 1084 | |
| 1085 | vaddr = kmap_skb_frag(frag); |
| 1086 | memcpy(vaddr + frag->page_offset + offset - start, |
| 1087 | from, copy); |
| 1088 | kunmap_skb_frag(vaddr); |
| 1089 | |
| 1090 | if ((len -= copy) == 0) |
| 1091 | return 0; |
| 1092 | offset += copy; |
| 1093 | from += copy; |
| 1094 | } |
| 1095 | start = end; |
| 1096 | } |
| 1097 | |
| 1098 | if (skb_shinfo(skb)->frag_list) { |
| 1099 | struct sk_buff *list = skb_shinfo(skb)->frag_list; |
| 1100 | |
| 1101 | for (; list; list = list->next) { |
| 1102 | int end; |
| 1103 | |
| 1104 | BUG_TRAP(start <= offset + len); |
| 1105 | |
| 1106 | end = start + list->len; |
| 1107 | if ((copy = end - offset) > 0) { |
| 1108 | if (copy > len) |
| 1109 | copy = len; |
| 1110 | if (skb_store_bits(list, offset - start, |
| 1111 | from, copy)) |
| 1112 | goto fault; |
| 1113 | if ((len -= copy) == 0) |
| 1114 | return 0; |
| 1115 | offset += copy; |
| 1116 | from += copy; |
| 1117 | } |
| 1118 | start = end; |
| 1119 | } |
| 1120 | } |
| 1121 | if (!len) |
| 1122 | return 0; |
| 1123 | |
| 1124 | fault: |
| 1125 | return -EFAULT; |
| 1126 | } |
| 1127 | |
| 1128 | EXPORT_SYMBOL(skb_store_bits); |
| 1129 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1130 | /* Checksum skb data. */ |
| 1131 | |
| 1132 | unsigned int skb_checksum(const struct sk_buff *skb, int offset, |
| 1133 | int len, unsigned int csum) |
| 1134 | { |
| 1135 | int start = skb_headlen(skb); |
| 1136 | int i, copy = start - offset; |
| 1137 | int pos = 0; |
| 1138 | |
| 1139 | /* Checksum header. */ |
| 1140 | if (copy > 0) { |
| 1141 | if (copy > len) |
| 1142 | copy = len; |
| 1143 | csum = csum_partial(skb->data + offset, copy, csum); |
| 1144 | if ((len -= copy) == 0) |
| 1145 | return csum; |
| 1146 | offset += copy; |
| 1147 | pos = copy; |
| 1148 | } |
| 1149 | |
| 1150 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
| 1151 | int end; |
| 1152 | |
| 1153 | BUG_TRAP(start <= offset + len); |
| 1154 | |
| 1155 | end = start + skb_shinfo(skb)->frags[i].size; |
| 1156 | if ((copy = end - offset) > 0) { |
| 1157 | unsigned int csum2; |
| 1158 | u8 *vaddr; |
| 1159 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; |
| 1160 | |
| 1161 | if (copy > len) |
| 1162 | copy = len; |
| 1163 | vaddr = kmap_skb_frag(frag); |
| 1164 | csum2 = csum_partial(vaddr + frag->page_offset + |
| 1165 | offset - start, copy, 0); |
| 1166 | kunmap_skb_frag(vaddr); |
| 1167 | csum = csum_block_add(csum, csum2, pos); |
| 1168 | if (!(len -= copy)) |
| 1169 | return csum; |
| 1170 | offset += copy; |
| 1171 | pos += copy; |
| 1172 | } |
| 1173 | start = end; |
| 1174 | } |
| 1175 | |
| 1176 | if (skb_shinfo(skb)->frag_list) { |
| 1177 | struct sk_buff *list = skb_shinfo(skb)->frag_list; |
| 1178 | |
| 1179 | for (; list; list = list->next) { |
| 1180 | int end; |
| 1181 | |
| 1182 | BUG_TRAP(start <= offset + len); |
| 1183 | |
| 1184 | end = start + list->len; |
| 1185 | if ((copy = end - offset) > 0) { |
| 1186 | unsigned int csum2; |
| 1187 | if (copy > len) |
| 1188 | copy = len; |
| 1189 | csum2 = skb_checksum(list, offset - start, |
| 1190 | copy, 0); |
| 1191 | csum = csum_block_add(csum, csum2, pos); |
| 1192 | if ((len -= copy) == 0) |
| 1193 | return csum; |
| 1194 | offset += copy; |
| 1195 | pos += copy; |
| 1196 | } |
| 1197 | start = end; |
| 1198 | } |
| 1199 | } |
Kris Katterjohn | 09a6266 | 2006-01-08 22:24:28 -0800 | [diff] [blame] | 1200 | BUG_ON(len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1201 | |
| 1202 | return csum; |
| 1203 | } |
| 1204 | |
| 1205 | /* Both of above in one bottle. */ |
| 1206 | |
| 1207 | unsigned int skb_copy_and_csum_bits(const struct sk_buff *skb, int offset, |
| 1208 | u8 *to, int len, unsigned int csum) |
| 1209 | { |
| 1210 | int start = skb_headlen(skb); |
| 1211 | int i, copy = start - offset; |
| 1212 | int pos = 0; |
| 1213 | |
| 1214 | /* Copy header. */ |
| 1215 | if (copy > 0) { |
| 1216 | if (copy > len) |
| 1217 | copy = len; |
| 1218 | csum = csum_partial_copy_nocheck(skb->data + offset, to, |
| 1219 | copy, csum); |
| 1220 | if ((len -= copy) == 0) |
| 1221 | return csum; |
| 1222 | offset += copy; |
| 1223 | to += copy; |
| 1224 | pos = copy; |
| 1225 | } |
| 1226 | |
| 1227 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { |
| 1228 | int end; |
| 1229 | |
| 1230 | BUG_TRAP(start <= offset + len); |
| 1231 | |
| 1232 | end = start + skb_shinfo(skb)->frags[i].size; |
| 1233 | if ((copy = end - offset) > 0) { |
| 1234 | unsigned int csum2; |
| 1235 | u8 *vaddr; |
| 1236 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; |
| 1237 | |
| 1238 | if (copy > len) |
| 1239 | copy = len; |
| 1240 | vaddr = kmap_skb_frag(frag); |
| 1241 | csum2 = csum_partial_copy_nocheck(vaddr + |
| 1242 | frag->page_offset + |
| 1243 | offset - start, to, |
| 1244 | copy, 0); |
| 1245 | kunmap_skb_frag(vaddr); |
| 1246 | csum = csum_block_add(csum, csum2, pos); |
| 1247 | if (!(len -= copy)) |
| 1248 | return csum; |
| 1249 | offset += copy; |
| 1250 | to += copy; |
| 1251 | pos += copy; |
| 1252 | } |
| 1253 | start = end; |
| 1254 | } |
| 1255 | |
| 1256 | if (skb_shinfo(skb)->frag_list) { |
| 1257 | struct sk_buff *list = skb_shinfo(skb)->frag_list; |
| 1258 | |
| 1259 | for (; list; list = list->next) { |
| 1260 | unsigned int csum2; |
| 1261 | int end; |
| 1262 | |
| 1263 | BUG_TRAP(start <= offset + len); |
| 1264 | |
| 1265 | end = start + list->len; |
| 1266 | if ((copy = end - offset) > 0) { |
| 1267 | if (copy > len) |
| 1268 | copy = len; |
| 1269 | csum2 = skb_copy_and_csum_bits(list, |
| 1270 | offset - start, |
| 1271 | to, copy, 0); |
| 1272 | csum = csum_block_add(csum, csum2, pos); |
| 1273 | if ((len -= copy) == 0) |
| 1274 | return csum; |
| 1275 | offset += copy; |
| 1276 | to += copy; |
| 1277 | pos += copy; |
| 1278 | } |
| 1279 | start = end; |
| 1280 | } |
| 1281 | } |
Kris Katterjohn | 09a6266 | 2006-01-08 22:24:28 -0800 | [diff] [blame] | 1282 | BUG_ON(len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1283 | return csum; |
| 1284 | } |
| 1285 | |
| 1286 | void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to) |
| 1287 | { |
| 1288 | unsigned int csum; |
| 1289 | long csstart; |
| 1290 | |
| 1291 | if (skb->ip_summed == CHECKSUM_HW) |
| 1292 | csstart = skb->h.raw - skb->data; |
| 1293 | else |
| 1294 | csstart = skb_headlen(skb); |
| 1295 | |
Kris Katterjohn | 09a6266 | 2006-01-08 22:24:28 -0800 | [diff] [blame] | 1296 | BUG_ON(csstart > skb_headlen(skb)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1297 | |
| 1298 | memcpy(to, skb->data, csstart); |
| 1299 | |
| 1300 | csum = 0; |
| 1301 | if (csstart != skb->len) |
| 1302 | csum = skb_copy_and_csum_bits(skb, csstart, to + csstart, |
| 1303 | skb->len - csstart, 0); |
| 1304 | |
| 1305 | if (skb->ip_summed == CHECKSUM_HW) { |
| 1306 | long csstuff = csstart + skb->csum; |
| 1307 | |
| 1308 | *((unsigned short *)(to + csstuff)) = csum_fold(csum); |
| 1309 | } |
| 1310 | } |
| 1311 | |
| 1312 | /** |
| 1313 | * skb_dequeue - remove from the head of the queue |
| 1314 | * @list: list to dequeue from |
| 1315 | * |
| 1316 | * Remove the head of the list. The list lock is taken so the function |
| 1317 | * may be used safely with other locking list functions. The head item is |
| 1318 | * returned or %NULL if the list is empty. |
| 1319 | */ |
| 1320 | |
| 1321 | struct sk_buff *skb_dequeue(struct sk_buff_head *list) |
| 1322 | { |
| 1323 | unsigned long flags; |
| 1324 | struct sk_buff *result; |
| 1325 | |
| 1326 | spin_lock_irqsave(&list->lock, flags); |
| 1327 | result = __skb_dequeue(list); |
| 1328 | spin_unlock_irqrestore(&list->lock, flags); |
| 1329 | return result; |
| 1330 | } |
| 1331 | |
| 1332 | /** |
| 1333 | * skb_dequeue_tail - remove from the tail of the queue |
| 1334 | * @list: list to dequeue from |
| 1335 | * |
| 1336 | * Remove the tail of the list. The list lock is taken so the function |
| 1337 | * may be used safely with other locking list functions. The tail item is |
| 1338 | * returned or %NULL if the list is empty. |
| 1339 | */ |
| 1340 | struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list) |
| 1341 | { |
| 1342 | unsigned long flags; |
| 1343 | struct sk_buff *result; |
| 1344 | |
| 1345 | spin_lock_irqsave(&list->lock, flags); |
| 1346 | result = __skb_dequeue_tail(list); |
| 1347 | spin_unlock_irqrestore(&list->lock, flags); |
| 1348 | return result; |
| 1349 | } |
| 1350 | |
| 1351 | /** |
| 1352 | * skb_queue_purge - empty a list |
| 1353 | * @list: list to empty |
| 1354 | * |
| 1355 | * Delete all buffers on an &sk_buff list. Each buffer is removed from |
| 1356 | * the list and one reference dropped. This function takes the list |
| 1357 | * lock and is atomic with respect to other list locking functions. |
| 1358 | */ |
| 1359 | void skb_queue_purge(struct sk_buff_head *list) |
| 1360 | { |
| 1361 | struct sk_buff *skb; |
| 1362 | while ((skb = skb_dequeue(list)) != NULL) |
| 1363 | kfree_skb(skb); |
| 1364 | } |
| 1365 | |
| 1366 | /** |
| 1367 | * skb_queue_head - queue a buffer at the list head |
| 1368 | * @list: list to use |
| 1369 | * @newsk: buffer to queue |
| 1370 | * |
| 1371 | * Queue a buffer at the start of the list. This function takes the |
| 1372 | * list lock and can be used safely with other locking &sk_buff functions |
| 1373 | * safely. |
| 1374 | * |
| 1375 | * A buffer cannot be placed on two lists at the same time. |
| 1376 | */ |
| 1377 | void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk) |
| 1378 | { |
| 1379 | unsigned long flags; |
| 1380 | |
| 1381 | spin_lock_irqsave(&list->lock, flags); |
| 1382 | __skb_queue_head(list, newsk); |
| 1383 | spin_unlock_irqrestore(&list->lock, flags); |
| 1384 | } |
| 1385 | |
| 1386 | /** |
| 1387 | * skb_queue_tail - queue a buffer at the list tail |
| 1388 | * @list: list to use |
| 1389 | * @newsk: buffer to queue |
| 1390 | * |
| 1391 | * Queue a buffer at the tail of the list. This function takes the |
| 1392 | * list lock and can be used safely with other locking &sk_buff functions |
| 1393 | * safely. |
| 1394 | * |
| 1395 | * A buffer cannot be placed on two lists at the same time. |
| 1396 | */ |
| 1397 | void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk) |
| 1398 | { |
| 1399 | unsigned long flags; |
| 1400 | |
| 1401 | spin_lock_irqsave(&list->lock, flags); |
| 1402 | __skb_queue_tail(list, newsk); |
| 1403 | spin_unlock_irqrestore(&list->lock, flags); |
| 1404 | } |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 1405 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1406 | /** |
| 1407 | * skb_unlink - remove a buffer from a list |
| 1408 | * @skb: buffer to remove |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 1409 | * @list: list to use |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1410 | * |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 1411 | * Remove a packet from a list. The list locks are taken and this |
| 1412 | * function is atomic with respect to other list locked calls |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1413 | * |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 1414 | * You must know what list the SKB is on. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1415 | */ |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 1416 | void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1417 | { |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 1418 | unsigned long flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1419 | |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 1420 | spin_lock_irqsave(&list->lock, flags); |
| 1421 | __skb_unlink(skb, list); |
| 1422 | spin_unlock_irqrestore(&list->lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1423 | } |
| 1424 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1425 | /** |
| 1426 | * skb_append - append a buffer |
| 1427 | * @old: buffer to insert after |
| 1428 | * @newsk: buffer to insert |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 1429 | * @list: list to use |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1430 | * |
| 1431 | * Place a packet after a given packet in a list. The list locks are taken |
| 1432 | * and this function is atomic with respect to other list locked calls. |
| 1433 | * A buffer cannot be placed on two lists at the same time. |
| 1434 | */ |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 1435 | void skb_append(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1436 | { |
| 1437 | unsigned long flags; |
| 1438 | |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 1439 | spin_lock_irqsave(&list->lock, flags); |
| 1440 | __skb_append(old, newsk, list); |
| 1441 | spin_unlock_irqrestore(&list->lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1442 | } |
| 1443 | |
| 1444 | |
| 1445 | /** |
| 1446 | * skb_insert - insert a buffer |
| 1447 | * @old: buffer to insert before |
| 1448 | * @newsk: buffer to insert |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 1449 | * @list: list to use |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1450 | * |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 1451 | * Place a packet before a given packet in a list. The list locks are |
| 1452 | * taken and this function is atomic with respect to other list locked |
| 1453 | * calls. |
| 1454 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1455 | * A buffer cannot be placed on two lists at the same time. |
| 1456 | */ |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 1457 | void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1458 | { |
| 1459 | unsigned long flags; |
| 1460 | |
David S. Miller | 8728b83 | 2005-08-09 19:25:21 -0700 | [diff] [blame] | 1461 | spin_lock_irqsave(&list->lock, flags); |
| 1462 | __skb_insert(newsk, old->prev, old, list); |
| 1463 | spin_unlock_irqrestore(&list->lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1464 | } |
| 1465 | |
| 1466 | #if 0 |
| 1467 | /* |
| 1468 | * Tune the memory allocator for a new MTU size. |
| 1469 | */ |
| 1470 | void skb_add_mtu(int mtu) |
| 1471 | { |
| 1472 | /* Must match allocation in alloc_skb */ |
| 1473 | mtu = SKB_DATA_ALIGN(mtu) + sizeof(struct skb_shared_info); |
| 1474 | |
| 1475 | kmem_add_cache_size(mtu); |
| 1476 | } |
| 1477 | #endif |
| 1478 | |
| 1479 | static inline void skb_split_inside_header(struct sk_buff *skb, |
| 1480 | struct sk_buff* skb1, |
| 1481 | const u32 len, const int pos) |
| 1482 | { |
| 1483 | int i; |
| 1484 | |
| 1485 | memcpy(skb_put(skb1, pos - len), skb->data + len, pos - len); |
| 1486 | |
| 1487 | /* And move data appendix as is. */ |
| 1488 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) |
| 1489 | skb_shinfo(skb1)->frags[i] = skb_shinfo(skb)->frags[i]; |
| 1490 | |
| 1491 | skb_shinfo(skb1)->nr_frags = skb_shinfo(skb)->nr_frags; |
| 1492 | skb_shinfo(skb)->nr_frags = 0; |
| 1493 | skb1->data_len = skb->data_len; |
| 1494 | skb1->len += skb1->data_len; |
| 1495 | skb->data_len = 0; |
| 1496 | skb->len = len; |
| 1497 | skb->tail = skb->data + len; |
| 1498 | } |
| 1499 | |
| 1500 | static inline void skb_split_no_header(struct sk_buff *skb, |
| 1501 | struct sk_buff* skb1, |
| 1502 | const u32 len, int pos) |
| 1503 | { |
| 1504 | int i, k = 0; |
| 1505 | const int nfrags = skb_shinfo(skb)->nr_frags; |
| 1506 | |
| 1507 | skb_shinfo(skb)->nr_frags = 0; |
| 1508 | skb1->len = skb1->data_len = skb->len - len; |
| 1509 | skb->len = len; |
| 1510 | skb->data_len = len - pos; |
| 1511 | |
| 1512 | for (i = 0; i < nfrags; i++) { |
| 1513 | int size = skb_shinfo(skb)->frags[i].size; |
| 1514 | |
| 1515 | if (pos + size > len) { |
| 1516 | skb_shinfo(skb1)->frags[k] = skb_shinfo(skb)->frags[i]; |
| 1517 | |
| 1518 | if (pos < len) { |
| 1519 | /* Split frag. |
| 1520 | * We have two variants in this case: |
| 1521 | * 1. Move all the frag to the second |
| 1522 | * part, if it is possible. F.e. |
| 1523 | * this approach is mandatory for TUX, |
| 1524 | * where splitting is expensive. |
| 1525 | * 2. Split is accurately. We make this. |
| 1526 | */ |
| 1527 | get_page(skb_shinfo(skb)->frags[i].page); |
| 1528 | skb_shinfo(skb1)->frags[0].page_offset += len - pos; |
| 1529 | skb_shinfo(skb1)->frags[0].size -= len - pos; |
| 1530 | skb_shinfo(skb)->frags[i].size = len - pos; |
| 1531 | skb_shinfo(skb)->nr_frags++; |
| 1532 | } |
| 1533 | k++; |
| 1534 | } else |
| 1535 | skb_shinfo(skb)->nr_frags++; |
| 1536 | pos += size; |
| 1537 | } |
| 1538 | skb_shinfo(skb1)->nr_frags = k; |
| 1539 | } |
| 1540 | |
| 1541 | /** |
| 1542 | * skb_split - Split fragmented skb to two parts at length len. |
| 1543 | * @skb: the buffer to split |
| 1544 | * @skb1: the buffer to receive the second part |
| 1545 | * @len: new length for skb |
| 1546 | */ |
| 1547 | void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len) |
| 1548 | { |
| 1549 | int pos = skb_headlen(skb); |
| 1550 | |
| 1551 | if (len < pos) /* Split line is inside header. */ |
| 1552 | skb_split_inside_header(skb, skb1, len, pos); |
| 1553 | else /* Second chunk has no header, nothing to copy. */ |
| 1554 | skb_split_no_header(skb, skb1, len, pos); |
| 1555 | } |
| 1556 | |
Thomas Graf | 677e90e | 2005-06-23 20:59:51 -0700 | [diff] [blame] | 1557 | /** |
| 1558 | * skb_prepare_seq_read - Prepare a sequential read of skb data |
| 1559 | * @skb: the buffer to read |
| 1560 | * @from: lower offset of data to be read |
| 1561 | * @to: upper offset of data to be read |
| 1562 | * @st: state variable |
| 1563 | * |
| 1564 | * Initializes the specified state variable. Must be called before |
| 1565 | * invoking skb_seq_read() for the first time. |
| 1566 | */ |
| 1567 | void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from, |
| 1568 | unsigned int to, struct skb_seq_state *st) |
| 1569 | { |
| 1570 | st->lower_offset = from; |
| 1571 | st->upper_offset = to; |
| 1572 | st->root_skb = st->cur_skb = skb; |
| 1573 | st->frag_idx = st->stepped_offset = 0; |
| 1574 | st->frag_data = NULL; |
| 1575 | } |
| 1576 | |
| 1577 | /** |
| 1578 | * skb_seq_read - Sequentially read skb data |
| 1579 | * @consumed: number of bytes consumed by the caller so far |
| 1580 | * @data: destination pointer for data to be returned |
| 1581 | * @st: state variable |
| 1582 | * |
| 1583 | * Reads a block of skb data at &consumed relative to the |
| 1584 | * lower offset specified to skb_prepare_seq_read(). Assigns |
| 1585 | * the head of the data block to &data and returns the length |
| 1586 | * of the block or 0 if the end of the skb data or the upper |
| 1587 | * offset has been reached. |
| 1588 | * |
| 1589 | * The caller is not required to consume all of the data |
| 1590 | * returned, i.e. &consumed is typically set to the number |
| 1591 | * of bytes already consumed and the next call to |
| 1592 | * skb_seq_read() will return the remaining part of the block. |
| 1593 | * |
| 1594 | * Note: The size of each block of data returned can be arbitary, |
| 1595 | * this limitation is the cost for zerocopy seqeuental |
| 1596 | * reads of potentially non linear data. |
| 1597 | * |
| 1598 | * Note: Fragment lists within fragments are not implemented |
| 1599 | * at the moment, state->root_skb could be replaced with |
| 1600 | * a stack for this purpose. |
| 1601 | */ |
| 1602 | unsigned int skb_seq_read(unsigned int consumed, const u8 **data, |
| 1603 | struct skb_seq_state *st) |
| 1604 | { |
| 1605 | unsigned int block_limit, abs_offset = consumed + st->lower_offset; |
| 1606 | skb_frag_t *frag; |
| 1607 | |
| 1608 | if (unlikely(abs_offset >= st->upper_offset)) |
| 1609 | return 0; |
| 1610 | |
| 1611 | next_skb: |
| 1612 | block_limit = skb_headlen(st->cur_skb); |
| 1613 | |
| 1614 | if (abs_offset < block_limit) { |
| 1615 | *data = st->cur_skb->data + abs_offset; |
| 1616 | return block_limit - abs_offset; |
| 1617 | } |
| 1618 | |
| 1619 | if (st->frag_idx == 0 && !st->frag_data) |
| 1620 | st->stepped_offset += skb_headlen(st->cur_skb); |
| 1621 | |
| 1622 | while (st->frag_idx < skb_shinfo(st->cur_skb)->nr_frags) { |
| 1623 | frag = &skb_shinfo(st->cur_skb)->frags[st->frag_idx]; |
| 1624 | block_limit = frag->size + st->stepped_offset; |
| 1625 | |
| 1626 | if (abs_offset < block_limit) { |
| 1627 | if (!st->frag_data) |
| 1628 | st->frag_data = kmap_skb_frag(frag); |
| 1629 | |
| 1630 | *data = (u8 *) st->frag_data + frag->page_offset + |
| 1631 | (abs_offset - st->stepped_offset); |
| 1632 | |
| 1633 | return block_limit - abs_offset; |
| 1634 | } |
| 1635 | |
| 1636 | if (st->frag_data) { |
| 1637 | kunmap_skb_frag(st->frag_data); |
| 1638 | st->frag_data = NULL; |
| 1639 | } |
| 1640 | |
| 1641 | st->frag_idx++; |
| 1642 | st->stepped_offset += frag->size; |
| 1643 | } |
| 1644 | |
| 1645 | if (st->cur_skb->next) { |
| 1646 | st->cur_skb = st->cur_skb->next; |
| 1647 | st->frag_idx = 0; |
| 1648 | goto next_skb; |
| 1649 | } else if (st->root_skb == st->cur_skb && |
| 1650 | skb_shinfo(st->root_skb)->frag_list) { |
| 1651 | st->cur_skb = skb_shinfo(st->root_skb)->frag_list; |
| 1652 | goto next_skb; |
| 1653 | } |
| 1654 | |
| 1655 | return 0; |
| 1656 | } |
| 1657 | |
| 1658 | /** |
| 1659 | * skb_abort_seq_read - Abort a sequential read of skb data |
| 1660 | * @st: state variable |
| 1661 | * |
| 1662 | * Must be called if skb_seq_read() was not called until it |
| 1663 | * returned 0. |
| 1664 | */ |
| 1665 | void skb_abort_seq_read(struct skb_seq_state *st) |
| 1666 | { |
| 1667 | if (st->frag_data) |
| 1668 | kunmap_skb_frag(st->frag_data); |
| 1669 | } |
| 1670 | |
Thomas Graf | 3fc7e8a | 2005-06-23 21:00:17 -0700 | [diff] [blame] | 1671 | #define TS_SKB_CB(state) ((struct skb_seq_state *) &((state)->cb)) |
| 1672 | |
| 1673 | static unsigned int skb_ts_get_next_block(unsigned int offset, const u8 **text, |
| 1674 | struct ts_config *conf, |
| 1675 | struct ts_state *state) |
| 1676 | { |
| 1677 | return skb_seq_read(offset, text, TS_SKB_CB(state)); |
| 1678 | } |
| 1679 | |
| 1680 | static void skb_ts_finish(struct ts_config *conf, struct ts_state *state) |
| 1681 | { |
| 1682 | skb_abort_seq_read(TS_SKB_CB(state)); |
| 1683 | } |
| 1684 | |
| 1685 | /** |
| 1686 | * skb_find_text - Find a text pattern in skb data |
| 1687 | * @skb: the buffer to look in |
| 1688 | * @from: search offset |
| 1689 | * @to: search limit |
| 1690 | * @config: textsearch configuration |
| 1691 | * @state: uninitialized textsearch state variable |
| 1692 | * |
| 1693 | * Finds a pattern in the skb data according to the specified |
| 1694 | * textsearch configuration. Use textsearch_next() to retrieve |
| 1695 | * subsequent occurrences of the pattern. Returns the offset |
| 1696 | * to the first occurrence or UINT_MAX if no match was found. |
| 1697 | */ |
| 1698 | unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, |
| 1699 | unsigned int to, struct ts_config *config, |
| 1700 | struct ts_state *state) |
| 1701 | { |
| 1702 | config->get_next_block = skb_ts_get_next_block; |
| 1703 | config->finish = skb_ts_finish; |
| 1704 | |
| 1705 | skb_prepare_seq_read(skb, from, to, TS_SKB_CB(state)); |
| 1706 | |
| 1707 | return textsearch_find(config, state); |
| 1708 | } |
| 1709 | |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 1710 | /** |
| 1711 | * skb_append_datato_frags: - append the user data to a skb |
| 1712 | * @sk: sock structure |
| 1713 | * @skb: skb structure to be appened with user data. |
| 1714 | * @getfrag: call back function to be used for getting the user data |
| 1715 | * @from: pointer to user message iov |
| 1716 | * @length: length of the iov message |
| 1717 | * |
| 1718 | * Description: This procedure append the user data in the fragment part |
| 1719 | * of the skb if any page alloc fails user this procedure returns -ENOMEM |
| 1720 | */ |
| 1721 | int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, |
Martin Waitz | dab9630 | 2005-12-05 13:40:12 -0800 | [diff] [blame] | 1722 | int (*getfrag)(void *from, char *to, int offset, |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 1723 | int len, int odd, struct sk_buff *skb), |
| 1724 | void *from, int length) |
| 1725 | { |
| 1726 | int frg_cnt = 0; |
| 1727 | skb_frag_t *frag = NULL; |
| 1728 | struct page *page = NULL; |
| 1729 | int copy, left; |
| 1730 | int offset = 0; |
| 1731 | int ret; |
| 1732 | |
| 1733 | do { |
| 1734 | /* Return error if we don't have space for new frag */ |
| 1735 | frg_cnt = skb_shinfo(skb)->nr_frags; |
| 1736 | if (frg_cnt >= MAX_SKB_FRAGS) |
| 1737 | return -EFAULT; |
| 1738 | |
| 1739 | /* allocate a new page for next frag */ |
| 1740 | page = alloc_pages(sk->sk_allocation, 0); |
| 1741 | |
| 1742 | /* If alloc_page fails just return failure and caller will |
| 1743 | * free previous allocated pages by doing kfree_skb() |
| 1744 | */ |
| 1745 | if (page == NULL) |
| 1746 | return -ENOMEM; |
| 1747 | |
| 1748 | /* initialize the next frag */ |
| 1749 | sk->sk_sndmsg_page = page; |
| 1750 | sk->sk_sndmsg_off = 0; |
| 1751 | skb_fill_page_desc(skb, frg_cnt, page, 0, 0); |
| 1752 | skb->truesize += PAGE_SIZE; |
| 1753 | atomic_add(PAGE_SIZE, &sk->sk_wmem_alloc); |
| 1754 | |
| 1755 | /* get the new initialized frag */ |
| 1756 | frg_cnt = skb_shinfo(skb)->nr_frags; |
| 1757 | frag = &skb_shinfo(skb)->frags[frg_cnt - 1]; |
| 1758 | |
| 1759 | /* copy the user data to page */ |
| 1760 | left = PAGE_SIZE - frag->page_offset; |
| 1761 | copy = (length > left)? left : length; |
| 1762 | |
| 1763 | ret = getfrag(from, (page_address(frag->page) + |
| 1764 | frag->page_offset + frag->size), |
| 1765 | offset, copy, 0, skb); |
| 1766 | if (ret < 0) |
| 1767 | return -EFAULT; |
| 1768 | |
| 1769 | /* copy was successful so update the size parameters */ |
| 1770 | sk->sk_sndmsg_off += copy; |
| 1771 | frag->size += copy; |
| 1772 | skb->len += copy; |
| 1773 | skb->data_len += copy; |
| 1774 | offset += copy; |
| 1775 | length -= copy; |
| 1776 | |
| 1777 | } while (length > 0); |
| 1778 | |
| 1779 | return 0; |
| 1780 | } |
| 1781 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1782 | void __init skb_init(void) |
| 1783 | { |
| 1784 | skbuff_head_cache = kmem_cache_create("skbuff_head_cache", |
| 1785 | sizeof(struct sk_buff), |
| 1786 | 0, |
| 1787 | SLAB_HWCACHE_ALIGN, |
| 1788 | NULL, NULL); |
| 1789 | if (!skbuff_head_cache) |
| 1790 | panic("cannot create skbuff cache"); |
David S. Miller | d179cd1 | 2005-08-17 14:57:30 -0700 | [diff] [blame] | 1791 | |
| 1792 | skbuff_fclone_cache = kmem_cache_create("skbuff_fclone_cache", |
| 1793 | (2*sizeof(struct sk_buff)) + |
| 1794 | sizeof(atomic_t), |
| 1795 | 0, |
| 1796 | SLAB_HWCACHE_ALIGN, |
| 1797 | NULL, NULL); |
| 1798 | if (!skbuff_fclone_cache) |
| 1799 | panic("cannot create skbuff cache"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1800 | } |
| 1801 | |
| 1802 | EXPORT_SYMBOL(___pskb_trim); |
| 1803 | EXPORT_SYMBOL(__kfree_skb); |
| 1804 | EXPORT_SYMBOL(__pskb_pull_tail); |
David S. Miller | d179cd1 | 2005-08-17 14:57:30 -0700 | [diff] [blame] | 1805 | EXPORT_SYMBOL(__alloc_skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1806 | EXPORT_SYMBOL(pskb_copy); |
| 1807 | EXPORT_SYMBOL(pskb_expand_head); |
| 1808 | EXPORT_SYMBOL(skb_checksum); |
| 1809 | EXPORT_SYMBOL(skb_clone); |
| 1810 | EXPORT_SYMBOL(skb_clone_fraglist); |
| 1811 | EXPORT_SYMBOL(skb_copy); |
| 1812 | EXPORT_SYMBOL(skb_copy_and_csum_bits); |
| 1813 | EXPORT_SYMBOL(skb_copy_and_csum_dev); |
| 1814 | EXPORT_SYMBOL(skb_copy_bits); |
| 1815 | EXPORT_SYMBOL(skb_copy_expand); |
| 1816 | EXPORT_SYMBOL(skb_over_panic); |
| 1817 | EXPORT_SYMBOL(skb_pad); |
| 1818 | EXPORT_SYMBOL(skb_realloc_headroom); |
| 1819 | EXPORT_SYMBOL(skb_under_panic); |
| 1820 | EXPORT_SYMBOL(skb_dequeue); |
| 1821 | EXPORT_SYMBOL(skb_dequeue_tail); |
| 1822 | EXPORT_SYMBOL(skb_insert); |
| 1823 | EXPORT_SYMBOL(skb_queue_purge); |
| 1824 | EXPORT_SYMBOL(skb_queue_head); |
| 1825 | EXPORT_SYMBOL(skb_queue_tail); |
| 1826 | EXPORT_SYMBOL(skb_unlink); |
| 1827 | EXPORT_SYMBOL(skb_append); |
| 1828 | EXPORT_SYMBOL(skb_split); |
Thomas Graf | 677e90e | 2005-06-23 20:59:51 -0700 | [diff] [blame] | 1829 | EXPORT_SYMBOL(skb_prepare_seq_read); |
| 1830 | EXPORT_SYMBOL(skb_seq_read); |
| 1831 | EXPORT_SYMBOL(skb_abort_seq_read); |
Thomas Graf | 3fc7e8a | 2005-06-23 21:00:17 -0700 | [diff] [blame] | 1832 | EXPORT_SYMBOL(skb_find_text); |
Ananda Raju | e89e9cf | 2005-10-18 15:46:41 -0700 | [diff] [blame] | 1833 | EXPORT_SYMBOL(skb_append_datato_frags); |