Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Definitions for the 'struct sk_buff' memory handlers. |
| 3 | * |
| 4 | * Authors: |
| 5 | * Alan Cox, <gw4pts@gw4pts.ampr.org> |
| 6 | * Florian La Roche, <rzsfl@rz.uni-sb.de> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License |
| 10 | * as published by the Free Software Foundation; either version |
| 11 | * 2 of the License, or (at your option) any later version. |
| 12 | */ |
| 13 | |
| 14 | #ifndef _LINUX_SKBUFF_H |
| 15 | #define _LINUX_SKBUFF_H |
| 16 | |
| 17 | #include <linux/config.h> |
| 18 | #include <linux/kernel.h> |
| 19 | #include <linux/compiler.h> |
| 20 | #include <linux/time.h> |
| 21 | #include <linux/cache.h> |
| 22 | |
| 23 | #include <asm/atomic.h> |
| 24 | #include <asm/types.h> |
| 25 | #include <linux/spinlock.h> |
| 26 | #include <linux/mm.h> |
| 27 | #include <linux/highmem.h> |
| 28 | #include <linux/poll.h> |
| 29 | #include <linux/net.h> |
Thomas Graf | 3fc7e8a | 2005-06-23 21:00:17 -0700 | [diff] [blame] | 30 | #include <linux/textsearch.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | #include <net/checksum.h> |
| 32 | |
| 33 | #define HAVE_ALLOC_SKB /* For the drivers to know */ |
| 34 | #define HAVE_ALIGNABLE_SKB /* Ditto 8) */ |
| 35 | #define SLAB_SKB /* Slabified skbuffs */ |
| 36 | |
| 37 | #define CHECKSUM_NONE 0 |
| 38 | #define CHECKSUM_HW 1 |
| 39 | #define CHECKSUM_UNNECESSARY 2 |
| 40 | |
| 41 | #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \ |
| 42 | ~(SMP_CACHE_BYTES - 1)) |
| 43 | #define SKB_MAX_ORDER(X, ORDER) (((PAGE_SIZE << (ORDER)) - (X) - \ |
| 44 | sizeof(struct skb_shared_info)) & \ |
| 45 | ~(SMP_CACHE_BYTES - 1)) |
| 46 | #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0)) |
| 47 | #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2)) |
| 48 | |
| 49 | /* A. Checksumming of received packets by device. |
| 50 | * |
| 51 | * NONE: device failed to checksum this packet. |
| 52 | * skb->csum is undefined. |
| 53 | * |
| 54 | * UNNECESSARY: device parsed packet and wouldbe verified checksum. |
| 55 | * skb->csum is undefined. |
| 56 | * It is bad option, but, unfortunately, many of vendors do this. |
| 57 | * Apparently with secret goal to sell you new device, when you |
| 58 | * will add new protocol to your host. F.e. IPv6. 8) |
| 59 | * |
| 60 | * HW: the most generic way. Device supplied checksum of _all_ |
| 61 | * the packet as seen by netif_rx in skb->csum. |
| 62 | * NOTE: Even if device supports only some protocols, but |
| 63 | * is able to produce some skb->csum, it MUST use HW, |
| 64 | * not UNNECESSARY. |
| 65 | * |
| 66 | * B. Checksumming on output. |
| 67 | * |
| 68 | * NONE: skb is checksummed by protocol or csum is not required. |
| 69 | * |
| 70 | * HW: device is required to csum packet as seen by hard_start_xmit |
| 71 | * from skb->h.raw to the end and to record the checksum |
| 72 | * at skb->h.raw+skb->csum. |
| 73 | * |
| 74 | * Device must show its capabilities in dev->features, set |
| 75 | * at device setup time. |
| 76 | * NETIF_F_HW_CSUM - it is clever device, it is able to checksum |
| 77 | * everything. |
| 78 | * NETIF_F_NO_CSUM - loopback or reliable single hop media. |
| 79 | * NETIF_F_IP_CSUM - device is dumb. It is able to csum only |
| 80 | * TCP/UDP over IPv4. Sigh. Vendors like this |
| 81 | * way by an unknown reason. Though, see comment above |
| 82 | * about CHECKSUM_UNNECESSARY. 8) |
| 83 | * |
| 84 | * Any questions? No questions, good. --ANK |
| 85 | */ |
| 86 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | struct net_device; |
| 88 | |
| 89 | #ifdef CONFIG_NETFILTER |
| 90 | struct nf_conntrack { |
| 91 | atomic_t use; |
| 92 | void (*destroy)(struct nf_conntrack *); |
| 93 | }; |
| 94 | |
| 95 | #ifdef CONFIG_BRIDGE_NETFILTER |
| 96 | struct nf_bridge_info { |
| 97 | atomic_t use; |
| 98 | struct net_device *physindev; |
| 99 | struct net_device *physoutdev; |
| 100 | #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) |
| 101 | struct net_device *netoutdev; |
| 102 | #endif |
| 103 | unsigned int mask; |
| 104 | unsigned long data[32 / sizeof(unsigned long)]; |
| 105 | }; |
| 106 | #endif |
| 107 | |
| 108 | #endif |
| 109 | |
| 110 | struct sk_buff_head { |
| 111 | /* These two members must be first. */ |
| 112 | struct sk_buff *next; |
| 113 | struct sk_buff *prev; |
| 114 | |
| 115 | __u32 qlen; |
| 116 | spinlock_t lock; |
| 117 | }; |
| 118 | |
| 119 | struct sk_buff; |
| 120 | |
| 121 | /* To allow 64K frame to be packed as single skb without frag_list */ |
| 122 | #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2) |
| 123 | |
| 124 | typedef struct skb_frag_struct skb_frag_t; |
| 125 | |
| 126 | struct skb_frag_struct { |
| 127 | struct page *page; |
| 128 | __u16 page_offset; |
| 129 | __u16 size; |
| 130 | }; |
| 131 | |
| 132 | /* This data is invariant across clones and lives at |
| 133 | * the end of the header data, ie. at skb->end. |
| 134 | */ |
| 135 | struct skb_shared_info { |
| 136 | atomic_t dataref; |
| 137 | unsigned int nr_frags; |
| 138 | unsigned short tso_size; |
| 139 | unsigned short tso_segs; |
| 140 | struct sk_buff *frag_list; |
| 141 | skb_frag_t frags[MAX_SKB_FRAGS]; |
| 142 | }; |
| 143 | |
| 144 | /* We divide dataref into two halves. The higher 16 bits hold references |
| 145 | * to the payload part of skb->data. The lower 16 bits hold references to |
| 146 | * the entire skb->data. It is up to the users of the skb to agree on |
| 147 | * where the payload starts. |
| 148 | * |
| 149 | * All users must obey the rule that the skb->data reference count must be |
| 150 | * greater than or equal to the payload reference count. |
| 151 | * |
| 152 | * Holding a reference to the payload part means that the user does not |
| 153 | * care about modifications to the header part of skb->data. |
| 154 | */ |
| 155 | #define SKB_DATAREF_SHIFT 16 |
| 156 | #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) |
| 157 | |
| 158 | /** |
| 159 | * struct sk_buff - socket buffer |
| 160 | * @next: Next buffer in list |
| 161 | * @prev: Previous buffer in list |
| 162 | * @list: List we are on |
| 163 | * @sk: Socket we are owned by |
| 164 | * @stamp: Time we arrived |
| 165 | * @dev: Device we arrived on/are leaving by |
| 166 | * @input_dev: Device we arrived on |
| 167 | * @real_dev: The real device we are using |
| 168 | * @h: Transport layer header |
| 169 | * @nh: Network layer header |
| 170 | * @mac: Link layer header |
Martin Waitz | 67be2dd | 2005-05-01 08:59:26 -0700 | [diff] [blame] | 171 | * @dst: destination entry |
| 172 | * @sp: the security path, used for xfrm |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | * @cb: Control buffer. Free for use by every layer. Put private vars here |
| 174 | * @len: Length of actual data |
| 175 | * @data_len: Data length |
| 176 | * @mac_len: Length of link layer header |
| 177 | * @csum: Checksum |
Martin Waitz | 67be2dd | 2005-05-01 08:59:26 -0700 | [diff] [blame] | 178 | * @local_df: allow local fragmentation |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 179 | * @cloned: Head may be cloned (check refcnt to be sure) |
| 180 | * @nohdr: Payload reference only, must not modify header |
| 181 | * @pkt_type: Packet class |
| 182 | * @ip_summed: Driver fed us an IP checksum |
| 183 | * @priority: Packet queueing priority |
| 184 | * @users: User count - see {datagram,tcp}.c |
| 185 | * @protocol: Packet protocol from driver |
| 186 | * @security: Security level of packet |
| 187 | * @truesize: Buffer size |
| 188 | * @head: Head of buffer |
| 189 | * @data: Data head pointer |
| 190 | * @tail: Tail pointer |
| 191 | * @end: End pointer |
| 192 | * @destructor: Destruct function |
| 193 | * @nfmark: Can be used for communication between hooks |
| 194 | * @nfcache: Cache info |
| 195 | * @nfct: Associated connection, if any |
| 196 | * @nfctinfo: Relationship of this skb to the connection |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c |
| 198 | * @private: Data which is private to the HIPPI implementation |
| 199 | * @tc_index: Traffic control index |
| 200 | * @tc_verd: traffic control verdict |
| 201 | * @tc_classid: traffic control classid |
| 202 | */ |
| 203 | |
| 204 | struct sk_buff { |
| 205 | /* These two members must be first. */ |
| 206 | struct sk_buff *next; |
| 207 | struct sk_buff *prev; |
| 208 | |
| 209 | struct sk_buff_head *list; |
| 210 | struct sock *sk; |
| 211 | struct timeval stamp; |
| 212 | struct net_device *dev; |
| 213 | struct net_device *input_dev; |
| 214 | struct net_device *real_dev; |
| 215 | |
| 216 | union { |
| 217 | struct tcphdr *th; |
| 218 | struct udphdr *uh; |
| 219 | struct icmphdr *icmph; |
| 220 | struct igmphdr *igmph; |
| 221 | struct iphdr *ipiph; |
| 222 | struct ipv6hdr *ipv6h; |
| 223 | unsigned char *raw; |
| 224 | } h; |
| 225 | |
| 226 | union { |
| 227 | struct iphdr *iph; |
| 228 | struct ipv6hdr *ipv6h; |
| 229 | struct arphdr *arph; |
| 230 | unsigned char *raw; |
| 231 | } nh; |
| 232 | |
| 233 | union { |
| 234 | unsigned char *raw; |
| 235 | } mac; |
| 236 | |
| 237 | struct dst_entry *dst; |
| 238 | struct sec_path *sp; |
| 239 | |
| 240 | /* |
| 241 | * This is the control buffer. It is free to use for every |
| 242 | * layer. Please put your private variables there. If you |
| 243 | * want to keep them across layers you have to do a skb_clone() |
| 244 | * first. This is owned by whoever has the skb queued ATM. |
| 245 | */ |
| 246 | char cb[40]; |
| 247 | |
| 248 | unsigned int len, |
| 249 | data_len, |
| 250 | mac_len, |
| 251 | csum; |
| 252 | unsigned char local_df, |
| 253 | cloned:1, |
| 254 | nohdr:1, |
| 255 | pkt_type, |
| 256 | ip_summed; |
| 257 | __u32 priority; |
| 258 | unsigned short protocol, |
| 259 | security; |
| 260 | |
| 261 | void (*destructor)(struct sk_buff *skb); |
| 262 | #ifdef CONFIG_NETFILTER |
| 263 | unsigned long nfmark; |
| 264 | __u32 nfcache; |
| 265 | __u32 nfctinfo; |
| 266 | struct nf_conntrack *nfct; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | #ifdef CONFIG_BRIDGE_NETFILTER |
| 268 | struct nf_bridge_info *nf_bridge; |
| 269 | #endif |
| 270 | #endif /* CONFIG_NETFILTER */ |
| 271 | #if defined(CONFIG_HIPPI) |
| 272 | union { |
| 273 | __u32 ifield; |
| 274 | } private; |
| 275 | #endif |
| 276 | #ifdef CONFIG_NET_SCHED |
| 277 | __u32 tc_index; /* traffic control index */ |
| 278 | #ifdef CONFIG_NET_CLS_ACT |
| 279 | __u32 tc_verd; /* traffic control verdict */ |
| 280 | __u32 tc_classid; /* traffic control classid */ |
| 281 | #endif |
| 282 | |
| 283 | #endif |
| 284 | |
| 285 | |
| 286 | /* These elements must be at the end, see alloc_skb() for details. */ |
| 287 | unsigned int truesize; |
| 288 | atomic_t users; |
| 289 | unsigned char *head, |
| 290 | *data, |
| 291 | *tail, |
| 292 | *end; |
| 293 | }; |
| 294 | |
| 295 | #ifdef __KERNEL__ |
| 296 | /* |
| 297 | * Handling routines are only of interest to the kernel |
| 298 | */ |
| 299 | #include <linux/slab.h> |
| 300 | |
| 301 | #include <asm/system.h> |
| 302 | |
| 303 | extern void __kfree_skb(struct sk_buff *skb); |
| 304 | extern struct sk_buff *alloc_skb(unsigned int size, int priority); |
| 305 | extern struct sk_buff *alloc_skb_from_cache(kmem_cache_t *cp, |
| 306 | unsigned int size, int priority); |
| 307 | extern void kfree_skbmem(struct sk_buff *skb); |
| 308 | extern struct sk_buff *skb_clone(struct sk_buff *skb, int priority); |
| 309 | extern struct sk_buff *skb_copy(const struct sk_buff *skb, int priority); |
| 310 | extern struct sk_buff *pskb_copy(struct sk_buff *skb, int gfp_mask); |
| 311 | extern int pskb_expand_head(struct sk_buff *skb, |
| 312 | int nhead, int ntail, int gfp_mask); |
| 313 | extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, |
| 314 | unsigned int headroom); |
| 315 | extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb, |
| 316 | int newheadroom, int newtailroom, |
| 317 | int priority); |
| 318 | extern struct sk_buff * skb_pad(struct sk_buff *skb, int pad); |
| 319 | #define dev_kfree_skb(a) kfree_skb(a) |
| 320 | extern void skb_over_panic(struct sk_buff *skb, int len, |
| 321 | void *here); |
| 322 | extern void skb_under_panic(struct sk_buff *skb, int len, |
| 323 | void *here); |
| 324 | |
Thomas Graf | 677e90e | 2005-06-23 20:59:51 -0700 | [diff] [blame] | 325 | struct skb_seq_state |
| 326 | { |
| 327 | __u32 lower_offset; |
| 328 | __u32 upper_offset; |
| 329 | __u32 frag_idx; |
| 330 | __u32 stepped_offset; |
| 331 | struct sk_buff *root_skb; |
| 332 | struct sk_buff *cur_skb; |
| 333 | __u8 *frag_data; |
| 334 | }; |
| 335 | |
| 336 | extern void skb_prepare_seq_read(struct sk_buff *skb, |
| 337 | unsigned int from, unsigned int to, |
| 338 | struct skb_seq_state *st); |
| 339 | extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data, |
| 340 | struct skb_seq_state *st); |
| 341 | extern void skb_abort_seq_read(struct skb_seq_state *st); |
| 342 | |
Thomas Graf | 3fc7e8a | 2005-06-23 21:00:17 -0700 | [diff] [blame] | 343 | extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, |
| 344 | unsigned int to, struct ts_config *config, |
| 345 | struct ts_state *state); |
| 346 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | /* Internal */ |
| 348 | #define skb_shinfo(SKB) ((struct skb_shared_info *)((SKB)->end)) |
| 349 | |
| 350 | /** |
| 351 | * skb_queue_empty - check if a queue is empty |
| 352 | * @list: queue head |
| 353 | * |
| 354 | * Returns true if the queue is empty, false otherwise. |
| 355 | */ |
| 356 | static inline int skb_queue_empty(const struct sk_buff_head *list) |
| 357 | { |
| 358 | return list->next == (struct sk_buff *)list; |
| 359 | } |
| 360 | |
| 361 | /** |
| 362 | * skb_get - reference buffer |
| 363 | * @skb: buffer to reference |
| 364 | * |
| 365 | * Makes another reference to a socket buffer and returns a pointer |
| 366 | * to the buffer. |
| 367 | */ |
| 368 | static inline struct sk_buff *skb_get(struct sk_buff *skb) |
| 369 | { |
| 370 | atomic_inc(&skb->users); |
| 371 | return skb; |
| 372 | } |
| 373 | |
| 374 | /* |
| 375 | * If users == 1, we are the only owner and are can avoid redundant |
| 376 | * atomic change. |
| 377 | */ |
| 378 | |
| 379 | /** |
| 380 | * kfree_skb - free an sk_buff |
| 381 | * @skb: buffer to free |
| 382 | * |
| 383 | * Drop a reference to the buffer and free it if the usage count has |
| 384 | * hit zero. |
| 385 | */ |
| 386 | static inline void kfree_skb(struct sk_buff *skb) |
| 387 | { |
| 388 | if (likely(atomic_read(&skb->users) == 1)) |
| 389 | smp_rmb(); |
| 390 | else if (likely(!atomic_dec_and_test(&skb->users))) |
| 391 | return; |
| 392 | __kfree_skb(skb); |
| 393 | } |
| 394 | |
| 395 | /** |
| 396 | * skb_cloned - is the buffer a clone |
| 397 | * @skb: buffer to check |
| 398 | * |
| 399 | * Returns true if the buffer was generated with skb_clone() and is |
| 400 | * one of multiple shared copies of the buffer. Cloned buffers are |
| 401 | * shared data so must not be written to under normal circumstances. |
| 402 | */ |
| 403 | static inline int skb_cloned(const struct sk_buff *skb) |
| 404 | { |
| 405 | return skb->cloned && |
| 406 | (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1; |
| 407 | } |
| 408 | |
| 409 | /** |
| 410 | * skb_header_cloned - is the header a clone |
| 411 | * @skb: buffer to check |
| 412 | * |
| 413 | * Returns true if modifying the header part of the buffer requires |
| 414 | * the data to be copied. |
| 415 | */ |
| 416 | static inline int skb_header_cloned(const struct sk_buff *skb) |
| 417 | { |
| 418 | int dataref; |
| 419 | |
| 420 | if (!skb->cloned) |
| 421 | return 0; |
| 422 | |
| 423 | dataref = atomic_read(&skb_shinfo(skb)->dataref); |
| 424 | dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT); |
| 425 | return dataref != 1; |
| 426 | } |
| 427 | |
| 428 | /** |
| 429 | * skb_header_release - release reference to header |
| 430 | * @skb: buffer to operate on |
| 431 | * |
| 432 | * Drop a reference to the header part of the buffer. This is done |
| 433 | * by acquiring a payload reference. You must not read from the header |
| 434 | * part of skb->data after this. |
| 435 | */ |
| 436 | static inline void skb_header_release(struct sk_buff *skb) |
| 437 | { |
| 438 | BUG_ON(skb->nohdr); |
| 439 | skb->nohdr = 1; |
| 440 | atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref); |
| 441 | } |
| 442 | |
| 443 | /** |
| 444 | * skb_shared - is the buffer shared |
| 445 | * @skb: buffer to check |
| 446 | * |
| 447 | * Returns true if more than one person has a reference to this |
| 448 | * buffer. |
| 449 | */ |
| 450 | static inline int skb_shared(const struct sk_buff *skb) |
| 451 | { |
| 452 | return atomic_read(&skb->users) != 1; |
| 453 | } |
| 454 | |
| 455 | /** |
| 456 | * skb_share_check - check if buffer is shared and if so clone it |
| 457 | * @skb: buffer to check |
| 458 | * @pri: priority for memory allocation |
| 459 | * |
| 460 | * If the buffer is shared the buffer is cloned and the old copy |
| 461 | * drops a reference. A new clone with a single reference is returned. |
| 462 | * If the buffer is not shared the original buffer is returned. When |
| 463 | * being called from interrupt status or with spinlocks held pri must |
| 464 | * be GFP_ATOMIC. |
| 465 | * |
| 466 | * NULL is returned on a memory allocation failure. |
| 467 | */ |
| 468 | static inline struct sk_buff *skb_share_check(struct sk_buff *skb, int pri) |
| 469 | { |
| 470 | might_sleep_if(pri & __GFP_WAIT); |
| 471 | if (skb_shared(skb)) { |
| 472 | struct sk_buff *nskb = skb_clone(skb, pri); |
| 473 | kfree_skb(skb); |
| 474 | skb = nskb; |
| 475 | } |
| 476 | return skb; |
| 477 | } |
| 478 | |
| 479 | /* |
| 480 | * Copy shared buffers into a new sk_buff. We effectively do COW on |
| 481 | * packets to handle cases where we have a local reader and forward |
| 482 | * and a couple of other messy ones. The normal one is tcpdumping |
| 483 | * a packet thats being forwarded. |
| 484 | */ |
| 485 | |
| 486 | /** |
| 487 | * skb_unshare - make a copy of a shared buffer |
| 488 | * @skb: buffer to check |
| 489 | * @pri: priority for memory allocation |
| 490 | * |
| 491 | * If the socket buffer is a clone then this function creates a new |
| 492 | * copy of the data, drops a reference count on the old copy and returns |
| 493 | * the new copy with the reference count at 1. If the buffer is not a clone |
| 494 | * the original buffer is returned. When called with a spinlock held or |
| 495 | * from interrupt state @pri must be %GFP_ATOMIC |
| 496 | * |
| 497 | * %NULL is returned on a memory allocation failure. |
| 498 | */ |
| 499 | static inline struct sk_buff *skb_unshare(struct sk_buff *skb, int pri) |
| 500 | { |
| 501 | might_sleep_if(pri & __GFP_WAIT); |
| 502 | if (skb_cloned(skb)) { |
| 503 | struct sk_buff *nskb = skb_copy(skb, pri); |
| 504 | kfree_skb(skb); /* Free our shared copy */ |
| 505 | skb = nskb; |
| 506 | } |
| 507 | return skb; |
| 508 | } |
| 509 | |
| 510 | /** |
| 511 | * skb_peek |
| 512 | * @list_: list to peek at |
| 513 | * |
| 514 | * Peek an &sk_buff. Unlike most other operations you _MUST_ |
| 515 | * be careful with this one. A peek leaves the buffer on the |
| 516 | * list and someone else may run off with it. You must hold |
| 517 | * the appropriate locks or have a private queue to do this. |
| 518 | * |
| 519 | * Returns %NULL for an empty list or a pointer to the head element. |
| 520 | * The reference count is not incremented and the reference is therefore |
| 521 | * volatile. Use with caution. |
| 522 | */ |
| 523 | static inline struct sk_buff *skb_peek(struct sk_buff_head *list_) |
| 524 | { |
| 525 | struct sk_buff *list = ((struct sk_buff *)list_)->next; |
| 526 | if (list == (struct sk_buff *)list_) |
| 527 | list = NULL; |
| 528 | return list; |
| 529 | } |
| 530 | |
| 531 | /** |
| 532 | * skb_peek_tail |
| 533 | * @list_: list to peek at |
| 534 | * |
| 535 | * Peek an &sk_buff. Unlike most other operations you _MUST_ |
| 536 | * be careful with this one. A peek leaves the buffer on the |
| 537 | * list and someone else may run off with it. You must hold |
| 538 | * the appropriate locks or have a private queue to do this. |
| 539 | * |
| 540 | * Returns %NULL for an empty list or a pointer to the tail element. |
| 541 | * The reference count is not incremented and the reference is therefore |
| 542 | * volatile. Use with caution. |
| 543 | */ |
| 544 | static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_) |
| 545 | { |
| 546 | struct sk_buff *list = ((struct sk_buff *)list_)->prev; |
| 547 | if (list == (struct sk_buff *)list_) |
| 548 | list = NULL; |
| 549 | return list; |
| 550 | } |
| 551 | |
| 552 | /** |
| 553 | * skb_queue_len - get queue length |
| 554 | * @list_: list to measure |
| 555 | * |
| 556 | * Return the length of an &sk_buff queue. |
| 557 | */ |
| 558 | static inline __u32 skb_queue_len(const struct sk_buff_head *list_) |
| 559 | { |
| 560 | return list_->qlen; |
| 561 | } |
| 562 | |
| 563 | static inline void skb_queue_head_init(struct sk_buff_head *list) |
| 564 | { |
| 565 | spin_lock_init(&list->lock); |
| 566 | list->prev = list->next = (struct sk_buff *)list; |
| 567 | list->qlen = 0; |
| 568 | } |
| 569 | |
| 570 | /* |
| 571 | * Insert an sk_buff at the start of a list. |
| 572 | * |
| 573 | * The "__skb_xxxx()" functions are the non-atomic ones that |
| 574 | * can only be called with interrupts disabled. |
| 575 | */ |
| 576 | |
| 577 | /** |
| 578 | * __skb_queue_head - queue a buffer at the list head |
| 579 | * @list: list to use |
| 580 | * @newsk: buffer to queue |
| 581 | * |
| 582 | * Queue a buffer at the start of a list. This function takes no locks |
| 583 | * and you must therefore hold required locks before calling it. |
| 584 | * |
| 585 | * A buffer cannot be placed on two lists at the same time. |
| 586 | */ |
| 587 | extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); |
| 588 | static inline void __skb_queue_head(struct sk_buff_head *list, |
| 589 | struct sk_buff *newsk) |
| 590 | { |
| 591 | struct sk_buff *prev, *next; |
| 592 | |
| 593 | newsk->list = list; |
| 594 | list->qlen++; |
| 595 | prev = (struct sk_buff *)list; |
| 596 | next = prev->next; |
| 597 | newsk->next = next; |
| 598 | newsk->prev = prev; |
| 599 | next->prev = prev->next = newsk; |
| 600 | } |
| 601 | |
| 602 | /** |
| 603 | * __skb_queue_tail - queue a buffer at the list tail |
| 604 | * @list: list to use |
| 605 | * @newsk: buffer to queue |
| 606 | * |
| 607 | * Queue a buffer at the end of a list. This function takes no locks |
| 608 | * and you must therefore hold required locks before calling it. |
| 609 | * |
| 610 | * A buffer cannot be placed on two lists at the same time. |
| 611 | */ |
| 612 | extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk); |
| 613 | static inline void __skb_queue_tail(struct sk_buff_head *list, |
| 614 | struct sk_buff *newsk) |
| 615 | { |
| 616 | struct sk_buff *prev, *next; |
| 617 | |
| 618 | newsk->list = list; |
| 619 | list->qlen++; |
| 620 | next = (struct sk_buff *)list; |
| 621 | prev = next->prev; |
| 622 | newsk->next = next; |
| 623 | newsk->prev = prev; |
| 624 | next->prev = prev->next = newsk; |
| 625 | } |
| 626 | |
| 627 | |
| 628 | /** |
| 629 | * __skb_dequeue - remove from the head of the queue |
| 630 | * @list: list to dequeue from |
| 631 | * |
| 632 | * Remove the head of the list. This function does not take any locks |
| 633 | * so must be used with appropriate locks held only. The head item is |
| 634 | * returned or %NULL if the list is empty. |
| 635 | */ |
| 636 | extern struct sk_buff *skb_dequeue(struct sk_buff_head *list); |
| 637 | static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list) |
| 638 | { |
| 639 | struct sk_buff *next, *prev, *result; |
| 640 | |
| 641 | prev = (struct sk_buff *) list; |
| 642 | next = prev->next; |
| 643 | result = NULL; |
| 644 | if (next != prev) { |
| 645 | result = next; |
| 646 | next = next->next; |
| 647 | list->qlen--; |
| 648 | next->prev = prev; |
| 649 | prev->next = next; |
| 650 | result->next = result->prev = NULL; |
| 651 | result->list = NULL; |
| 652 | } |
| 653 | return result; |
| 654 | } |
| 655 | |
| 656 | |
| 657 | /* |
| 658 | * Insert a packet on a list. |
| 659 | */ |
| 660 | extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk); |
| 661 | static inline void __skb_insert(struct sk_buff *newsk, |
| 662 | struct sk_buff *prev, struct sk_buff *next, |
| 663 | struct sk_buff_head *list) |
| 664 | { |
| 665 | newsk->next = next; |
| 666 | newsk->prev = prev; |
| 667 | next->prev = prev->next = newsk; |
| 668 | newsk->list = list; |
| 669 | list->qlen++; |
| 670 | } |
| 671 | |
| 672 | /* |
| 673 | * Place a packet after a given packet in a list. |
| 674 | */ |
| 675 | extern void skb_append(struct sk_buff *old, struct sk_buff *newsk); |
| 676 | static inline void __skb_append(struct sk_buff *old, struct sk_buff *newsk) |
| 677 | { |
| 678 | __skb_insert(newsk, old, old->next, old->list); |
| 679 | } |
| 680 | |
| 681 | /* |
| 682 | * remove sk_buff from list. _Must_ be called atomically, and with |
| 683 | * the list known.. |
| 684 | */ |
| 685 | extern void skb_unlink(struct sk_buff *skb); |
| 686 | static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) |
| 687 | { |
| 688 | struct sk_buff *next, *prev; |
| 689 | |
| 690 | list->qlen--; |
| 691 | next = skb->next; |
| 692 | prev = skb->prev; |
| 693 | skb->next = skb->prev = NULL; |
| 694 | skb->list = NULL; |
| 695 | next->prev = prev; |
| 696 | prev->next = next; |
| 697 | } |
| 698 | |
| 699 | |
| 700 | /* XXX: more streamlined implementation */ |
| 701 | |
| 702 | /** |
| 703 | * __skb_dequeue_tail - remove from the tail of the queue |
| 704 | * @list: list to dequeue from |
| 705 | * |
| 706 | * Remove the tail of the list. This function does not take any locks |
| 707 | * so must be used with appropriate locks held only. The tail item is |
| 708 | * returned or %NULL if the list is empty. |
| 709 | */ |
| 710 | extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list); |
| 711 | static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list) |
| 712 | { |
| 713 | struct sk_buff *skb = skb_peek_tail(list); |
| 714 | if (skb) |
| 715 | __skb_unlink(skb, list); |
| 716 | return skb; |
| 717 | } |
| 718 | |
| 719 | |
| 720 | static inline int skb_is_nonlinear(const struct sk_buff *skb) |
| 721 | { |
| 722 | return skb->data_len; |
| 723 | } |
| 724 | |
| 725 | static inline unsigned int skb_headlen(const struct sk_buff *skb) |
| 726 | { |
| 727 | return skb->len - skb->data_len; |
| 728 | } |
| 729 | |
| 730 | static inline int skb_pagelen(const struct sk_buff *skb) |
| 731 | { |
| 732 | int i, len = 0; |
| 733 | |
| 734 | for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) |
| 735 | len += skb_shinfo(skb)->frags[i].size; |
| 736 | return len + skb_headlen(skb); |
| 737 | } |
| 738 | |
| 739 | static inline void skb_fill_page_desc(struct sk_buff *skb, int i, |
| 740 | struct page *page, int off, int size) |
| 741 | { |
| 742 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; |
| 743 | |
| 744 | frag->page = page; |
| 745 | frag->page_offset = off; |
| 746 | frag->size = size; |
| 747 | skb_shinfo(skb)->nr_frags = i + 1; |
| 748 | } |
| 749 | |
| 750 | #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags) |
| 751 | #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list) |
| 752 | #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) |
| 753 | |
| 754 | /* |
| 755 | * Add data to an sk_buff |
| 756 | */ |
| 757 | static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len) |
| 758 | { |
| 759 | unsigned char *tmp = skb->tail; |
| 760 | SKB_LINEAR_ASSERT(skb); |
| 761 | skb->tail += len; |
| 762 | skb->len += len; |
| 763 | return tmp; |
| 764 | } |
| 765 | |
| 766 | /** |
| 767 | * skb_put - add data to a buffer |
| 768 | * @skb: buffer to use |
| 769 | * @len: amount of data to add |
| 770 | * |
| 771 | * This function extends the used data area of the buffer. If this would |
| 772 | * exceed the total buffer size the kernel will panic. A pointer to the |
| 773 | * first byte of the extra data is returned. |
| 774 | */ |
| 775 | static inline unsigned char *skb_put(struct sk_buff *skb, unsigned int len) |
| 776 | { |
| 777 | unsigned char *tmp = skb->tail; |
| 778 | SKB_LINEAR_ASSERT(skb); |
| 779 | skb->tail += len; |
| 780 | skb->len += len; |
| 781 | if (unlikely(skb->tail>skb->end)) |
| 782 | skb_over_panic(skb, len, current_text_addr()); |
| 783 | return tmp; |
| 784 | } |
| 785 | |
| 786 | static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len) |
| 787 | { |
| 788 | skb->data -= len; |
| 789 | skb->len += len; |
| 790 | return skb->data; |
| 791 | } |
| 792 | |
| 793 | /** |
| 794 | * skb_push - add data to the start of a buffer |
| 795 | * @skb: buffer to use |
| 796 | * @len: amount of data to add |
| 797 | * |
| 798 | * This function extends the used data area of the buffer at the buffer |
| 799 | * start. If this would exceed the total buffer headroom the kernel will |
| 800 | * panic. A pointer to the first byte of the extra data is returned. |
| 801 | */ |
| 802 | static inline unsigned char *skb_push(struct sk_buff *skb, unsigned int len) |
| 803 | { |
| 804 | skb->data -= len; |
| 805 | skb->len += len; |
| 806 | if (unlikely(skb->data<skb->head)) |
| 807 | skb_under_panic(skb, len, current_text_addr()); |
| 808 | return skb->data; |
| 809 | } |
| 810 | |
| 811 | static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len) |
| 812 | { |
| 813 | skb->len -= len; |
| 814 | BUG_ON(skb->len < skb->data_len); |
| 815 | return skb->data += len; |
| 816 | } |
| 817 | |
| 818 | /** |
| 819 | * skb_pull - remove data from the start of a buffer |
| 820 | * @skb: buffer to use |
| 821 | * @len: amount of data to remove |
| 822 | * |
| 823 | * This function removes data from the start of a buffer, returning |
| 824 | * the memory to the headroom. A pointer to the next data in the buffer |
| 825 | * is returned. Once the data has been pulled future pushes will overwrite |
| 826 | * the old data. |
| 827 | */ |
| 828 | static inline unsigned char *skb_pull(struct sk_buff *skb, unsigned int len) |
| 829 | { |
| 830 | return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len); |
| 831 | } |
| 832 | |
| 833 | extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta); |
| 834 | |
| 835 | static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len) |
| 836 | { |
| 837 | if (len > skb_headlen(skb) && |
| 838 | !__pskb_pull_tail(skb, len-skb_headlen(skb))) |
| 839 | return NULL; |
| 840 | skb->len -= len; |
| 841 | return skb->data += len; |
| 842 | } |
| 843 | |
| 844 | static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len) |
| 845 | { |
| 846 | return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len); |
| 847 | } |
| 848 | |
| 849 | static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len) |
| 850 | { |
| 851 | if (likely(len <= skb_headlen(skb))) |
| 852 | return 1; |
| 853 | if (unlikely(len > skb->len)) |
| 854 | return 0; |
| 855 | return __pskb_pull_tail(skb, len-skb_headlen(skb)) != NULL; |
| 856 | } |
| 857 | |
| 858 | /** |
| 859 | * skb_headroom - bytes at buffer head |
| 860 | * @skb: buffer to check |
| 861 | * |
| 862 | * Return the number of bytes of free space at the head of an &sk_buff. |
| 863 | */ |
| 864 | static inline int skb_headroom(const struct sk_buff *skb) |
| 865 | { |
| 866 | return skb->data - skb->head; |
| 867 | } |
| 868 | |
| 869 | /** |
| 870 | * skb_tailroom - bytes at buffer end |
| 871 | * @skb: buffer to check |
| 872 | * |
| 873 | * Return the number of bytes of free space at the tail of an sk_buff |
| 874 | */ |
| 875 | static inline int skb_tailroom(const struct sk_buff *skb) |
| 876 | { |
| 877 | return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail; |
| 878 | } |
| 879 | |
| 880 | /** |
| 881 | * skb_reserve - adjust headroom |
| 882 | * @skb: buffer to alter |
| 883 | * @len: bytes to move |
| 884 | * |
| 885 | * Increase the headroom of an empty &sk_buff by reducing the tail |
| 886 | * room. This is only allowed for an empty buffer. |
| 887 | */ |
| 888 | static inline void skb_reserve(struct sk_buff *skb, unsigned int len) |
| 889 | { |
| 890 | skb->data += len; |
| 891 | skb->tail += len; |
| 892 | } |
| 893 | |
| 894 | /* |
| 895 | * CPUs often take a performance hit when accessing unaligned memory |
| 896 | * locations. The actual performance hit varies, it can be small if the |
| 897 | * hardware handles it or large if we have to take an exception and fix it |
| 898 | * in software. |
| 899 | * |
| 900 | * Since an ethernet header is 14 bytes network drivers often end up with |
| 901 | * the IP header at an unaligned offset. The IP header can be aligned by |
| 902 | * shifting the start of the packet by 2 bytes. Drivers should do this |
| 903 | * with: |
| 904 | * |
| 905 | * skb_reserve(NET_IP_ALIGN); |
| 906 | * |
| 907 | * The downside to this alignment of the IP header is that the DMA is now |
| 908 | * unaligned. On some architectures the cost of an unaligned DMA is high |
| 909 | * and this cost outweighs the gains made by aligning the IP header. |
| 910 | * |
| 911 | * Since this trade off varies between architectures, we allow NET_IP_ALIGN |
| 912 | * to be overridden. |
| 913 | */ |
| 914 | #ifndef NET_IP_ALIGN |
| 915 | #define NET_IP_ALIGN 2 |
| 916 | #endif |
| 917 | |
| 918 | extern int ___pskb_trim(struct sk_buff *skb, unsigned int len, int realloc); |
| 919 | |
| 920 | static inline void __skb_trim(struct sk_buff *skb, unsigned int len) |
| 921 | { |
| 922 | if (!skb->data_len) { |
| 923 | skb->len = len; |
| 924 | skb->tail = skb->data + len; |
| 925 | } else |
| 926 | ___pskb_trim(skb, len, 0); |
| 927 | } |
| 928 | |
| 929 | /** |
| 930 | * skb_trim - remove end from a buffer |
| 931 | * @skb: buffer to alter |
| 932 | * @len: new length |
| 933 | * |
| 934 | * Cut the length of a buffer down by removing data from the tail. If |
| 935 | * the buffer is already under the length specified it is not modified. |
| 936 | */ |
| 937 | static inline void skb_trim(struct sk_buff *skb, unsigned int len) |
| 938 | { |
| 939 | if (skb->len > len) |
| 940 | __skb_trim(skb, len); |
| 941 | } |
| 942 | |
| 943 | |
| 944 | static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) |
| 945 | { |
| 946 | if (!skb->data_len) { |
| 947 | skb->len = len; |
| 948 | skb->tail = skb->data+len; |
| 949 | return 0; |
| 950 | } |
| 951 | return ___pskb_trim(skb, len, 1); |
| 952 | } |
| 953 | |
| 954 | static inline int pskb_trim(struct sk_buff *skb, unsigned int len) |
| 955 | { |
| 956 | return (len < skb->len) ? __pskb_trim(skb, len) : 0; |
| 957 | } |
| 958 | |
| 959 | /** |
| 960 | * skb_orphan - orphan a buffer |
| 961 | * @skb: buffer to orphan |
| 962 | * |
| 963 | * If a buffer currently has an owner then we call the owner's |
| 964 | * destructor function and make the @skb unowned. The buffer continues |
| 965 | * to exist but is no longer charged to its former owner. |
| 966 | */ |
| 967 | static inline void skb_orphan(struct sk_buff *skb) |
| 968 | { |
| 969 | if (skb->destructor) |
| 970 | skb->destructor(skb); |
| 971 | skb->destructor = NULL; |
| 972 | skb->sk = NULL; |
| 973 | } |
| 974 | |
| 975 | /** |
| 976 | * __skb_queue_purge - empty a list |
| 977 | * @list: list to empty |
| 978 | * |
| 979 | * Delete all buffers on an &sk_buff list. Each buffer is removed from |
| 980 | * the list and one reference dropped. This function does not take the |
| 981 | * list lock and the caller must hold the relevant locks to use it. |
| 982 | */ |
| 983 | extern void skb_queue_purge(struct sk_buff_head *list); |
| 984 | static inline void __skb_queue_purge(struct sk_buff_head *list) |
| 985 | { |
| 986 | struct sk_buff *skb; |
| 987 | while ((skb = __skb_dequeue(list)) != NULL) |
| 988 | kfree_skb(skb); |
| 989 | } |
| 990 | |
Pavel Pisa | 4dc3b16 | 2005-05-01 08:59:25 -0700 | [diff] [blame] | 991 | #ifndef CONFIG_HAVE_ARCH_DEV_ALLOC_SKB |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 992 | /** |
| 993 | * __dev_alloc_skb - allocate an skbuff for sending |
| 994 | * @length: length to allocate |
| 995 | * @gfp_mask: get_free_pages mask, passed to alloc_skb |
| 996 | * |
| 997 | * Allocate a new &sk_buff and assign it a usage count of one. The |
| 998 | * buffer has unspecified headroom built in. Users should allocate |
| 999 | * the headroom they think they need without accounting for the |
| 1000 | * built in space. The built in space is used for optimisations. |
| 1001 | * |
| 1002 | * %NULL is returned in there is no free memory. |
| 1003 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1004 | static inline struct sk_buff *__dev_alloc_skb(unsigned int length, |
| 1005 | int gfp_mask) |
| 1006 | { |
| 1007 | struct sk_buff *skb = alloc_skb(length + 16, gfp_mask); |
| 1008 | if (likely(skb)) |
| 1009 | skb_reserve(skb, 16); |
| 1010 | return skb; |
| 1011 | } |
| 1012 | #else |
| 1013 | extern struct sk_buff *__dev_alloc_skb(unsigned int length, int gfp_mask); |
| 1014 | #endif |
| 1015 | |
| 1016 | /** |
| 1017 | * dev_alloc_skb - allocate an skbuff for sending |
| 1018 | * @length: length to allocate |
| 1019 | * |
| 1020 | * Allocate a new &sk_buff and assign it a usage count of one. The |
| 1021 | * buffer has unspecified headroom built in. Users should allocate |
| 1022 | * the headroom they think they need without accounting for the |
| 1023 | * built in space. The built in space is used for optimisations. |
| 1024 | * |
| 1025 | * %NULL is returned in there is no free memory. Although this function |
| 1026 | * allocates memory it can be called from an interrupt. |
| 1027 | */ |
| 1028 | static inline struct sk_buff *dev_alloc_skb(unsigned int length) |
| 1029 | { |
| 1030 | return __dev_alloc_skb(length, GFP_ATOMIC); |
| 1031 | } |
| 1032 | |
| 1033 | /** |
| 1034 | * skb_cow - copy header of skb when it is required |
| 1035 | * @skb: buffer to cow |
| 1036 | * @headroom: needed headroom |
| 1037 | * |
| 1038 | * If the skb passed lacks sufficient headroom or its data part |
| 1039 | * is shared, data is reallocated. If reallocation fails, an error |
| 1040 | * is returned and original skb is not changed. |
| 1041 | * |
| 1042 | * The result is skb with writable area skb->head...skb->tail |
| 1043 | * and at least @headroom of space at head. |
| 1044 | */ |
| 1045 | static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) |
| 1046 | { |
| 1047 | int delta = (headroom > 16 ? headroom : 16) - skb_headroom(skb); |
| 1048 | |
| 1049 | if (delta < 0) |
| 1050 | delta = 0; |
| 1051 | |
| 1052 | if (delta || skb_cloned(skb)) |
| 1053 | return pskb_expand_head(skb, (delta + 15) & ~15, 0, GFP_ATOMIC); |
| 1054 | return 0; |
| 1055 | } |
| 1056 | |
| 1057 | /** |
| 1058 | * skb_padto - pad an skbuff up to a minimal size |
| 1059 | * @skb: buffer to pad |
| 1060 | * @len: minimal length |
| 1061 | * |
| 1062 | * Pads up a buffer to ensure the trailing bytes exist and are |
| 1063 | * blanked. If the buffer already contains sufficient data it |
| 1064 | * is untouched. Returns the buffer, which may be a replacement |
| 1065 | * for the original, or NULL for out of memory - in which case |
| 1066 | * the original buffer is still freed. |
| 1067 | */ |
| 1068 | |
| 1069 | static inline struct sk_buff *skb_padto(struct sk_buff *skb, unsigned int len) |
| 1070 | { |
| 1071 | unsigned int size = skb->len; |
| 1072 | if (likely(size >= len)) |
| 1073 | return skb; |
| 1074 | return skb_pad(skb, len-size); |
| 1075 | } |
| 1076 | |
| 1077 | static inline int skb_add_data(struct sk_buff *skb, |
| 1078 | char __user *from, int copy) |
| 1079 | { |
| 1080 | const int off = skb->len; |
| 1081 | |
| 1082 | if (skb->ip_summed == CHECKSUM_NONE) { |
| 1083 | int err = 0; |
| 1084 | unsigned int csum = csum_and_copy_from_user(from, |
| 1085 | skb_put(skb, copy), |
| 1086 | copy, 0, &err); |
| 1087 | if (!err) { |
| 1088 | skb->csum = csum_block_add(skb->csum, csum, off); |
| 1089 | return 0; |
| 1090 | } |
| 1091 | } else if (!copy_from_user(skb_put(skb, copy), from, copy)) |
| 1092 | return 0; |
| 1093 | |
| 1094 | __skb_trim(skb, off); |
| 1095 | return -EFAULT; |
| 1096 | } |
| 1097 | |
| 1098 | static inline int skb_can_coalesce(struct sk_buff *skb, int i, |
| 1099 | struct page *page, int off) |
| 1100 | { |
| 1101 | if (i) { |
| 1102 | struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1]; |
| 1103 | |
| 1104 | return page == frag->page && |
| 1105 | off == frag->page_offset + frag->size; |
| 1106 | } |
| 1107 | return 0; |
| 1108 | } |
| 1109 | |
| 1110 | /** |
| 1111 | * skb_linearize - convert paged skb to linear one |
| 1112 | * @skb: buffer to linarize |
| 1113 | * @gfp: allocation mode |
| 1114 | * |
| 1115 | * If there is no free memory -ENOMEM is returned, otherwise zero |
| 1116 | * is returned and the old skb data released. |
| 1117 | */ |
| 1118 | extern int __skb_linearize(struct sk_buff *skb, int gfp); |
| 1119 | static inline int skb_linearize(struct sk_buff *skb, int gfp) |
| 1120 | { |
| 1121 | return __skb_linearize(skb, gfp); |
| 1122 | } |
| 1123 | |
| 1124 | /** |
| 1125 | * skb_postpull_rcsum - update checksum for received skb after pull |
| 1126 | * @skb: buffer to update |
| 1127 | * @start: start of data before pull |
| 1128 | * @len: length of data pulled |
| 1129 | * |
| 1130 | * After doing a pull on a received packet, you need to call this to |
| 1131 | * update the CHECKSUM_HW checksum, or set ip_summed to CHECKSUM_NONE |
| 1132 | * so that it can be recomputed from scratch. |
| 1133 | */ |
| 1134 | |
| 1135 | static inline void skb_postpull_rcsum(struct sk_buff *skb, |
| 1136 | const void *start, int len) |
| 1137 | { |
| 1138 | if (skb->ip_summed == CHECKSUM_HW) |
| 1139 | skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0)); |
| 1140 | } |
| 1141 | |
| 1142 | /** |
| 1143 | * pskb_trim_rcsum - trim received skb and update checksum |
| 1144 | * @skb: buffer to trim |
| 1145 | * @len: new length |
| 1146 | * |
| 1147 | * This is exactly the same as pskb_trim except that it ensures the |
| 1148 | * checksum of received packets are still valid after the operation. |
| 1149 | */ |
| 1150 | |
| 1151 | static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len) |
| 1152 | { |
| 1153 | if (len >= skb->len) |
| 1154 | return 0; |
| 1155 | if (skb->ip_summed == CHECKSUM_HW) |
| 1156 | skb->ip_summed = CHECKSUM_NONE; |
| 1157 | return __pskb_trim(skb, len); |
| 1158 | } |
| 1159 | |
| 1160 | static inline void *kmap_skb_frag(const skb_frag_t *frag) |
| 1161 | { |
| 1162 | #ifdef CONFIG_HIGHMEM |
| 1163 | BUG_ON(in_irq()); |
| 1164 | |
| 1165 | local_bh_disable(); |
| 1166 | #endif |
| 1167 | return kmap_atomic(frag->page, KM_SKB_DATA_SOFTIRQ); |
| 1168 | } |
| 1169 | |
| 1170 | static inline void kunmap_skb_frag(void *vaddr) |
| 1171 | { |
| 1172 | kunmap_atomic(vaddr, KM_SKB_DATA_SOFTIRQ); |
| 1173 | #ifdef CONFIG_HIGHMEM |
| 1174 | local_bh_enable(); |
| 1175 | #endif |
| 1176 | } |
| 1177 | |
| 1178 | #define skb_queue_walk(queue, skb) \ |
| 1179 | for (skb = (queue)->next; \ |
| 1180 | prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \ |
| 1181 | skb = skb->next) |
| 1182 | |
| 1183 | |
| 1184 | extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, |
| 1185 | int noblock, int *err); |
| 1186 | extern unsigned int datagram_poll(struct file *file, struct socket *sock, |
| 1187 | struct poll_table_struct *wait); |
| 1188 | extern int skb_copy_datagram_iovec(const struct sk_buff *from, |
| 1189 | int offset, struct iovec *to, |
| 1190 | int size); |
| 1191 | extern int skb_copy_and_csum_datagram_iovec(const |
| 1192 | struct sk_buff *skb, |
| 1193 | int hlen, |
| 1194 | struct iovec *iov); |
| 1195 | extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb); |
| 1196 | extern unsigned int skb_checksum(const struct sk_buff *skb, int offset, |
| 1197 | int len, unsigned int csum); |
| 1198 | extern int skb_copy_bits(const struct sk_buff *skb, int offset, |
| 1199 | void *to, int len); |
Herbert Xu | 357b40a | 2005-04-19 22:30:14 -0700 | [diff] [blame] | 1200 | extern int skb_store_bits(const struct sk_buff *skb, int offset, |
| 1201 | void *from, int len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1202 | extern unsigned int skb_copy_and_csum_bits(const struct sk_buff *skb, |
| 1203 | int offset, u8 *to, int len, |
| 1204 | unsigned int csum); |
| 1205 | extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); |
| 1206 | extern void skb_split(struct sk_buff *skb, |
| 1207 | struct sk_buff *skb1, const u32 len); |
| 1208 | |
| 1209 | static inline void *skb_header_pointer(const struct sk_buff *skb, int offset, |
| 1210 | int len, void *buffer) |
| 1211 | { |
| 1212 | int hlen = skb_headlen(skb); |
| 1213 | |
| 1214 | if (offset + len <= hlen) |
| 1215 | return skb->data + offset; |
| 1216 | |
| 1217 | if (skb_copy_bits(skb, offset, buffer, len) < 0) |
| 1218 | return NULL; |
| 1219 | |
| 1220 | return buffer; |
| 1221 | } |
| 1222 | |
| 1223 | extern void skb_init(void); |
| 1224 | extern void skb_add_mtu(int mtu); |
| 1225 | |
| 1226 | #ifdef CONFIG_NETFILTER |
| 1227 | static inline void nf_conntrack_put(struct nf_conntrack *nfct) |
| 1228 | { |
| 1229 | if (nfct && atomic_dec_and_test(&nfct->use)) |
| 1230 | nfct->destroy(nfct); |
| 1231 | } |
| 1232 | static inline void nf_conntrack_get(struct nf_conntrack *nfct) |
| 1233 | { |
| 1234 | if (nfct) |
| 1235 | atomic_inc(&nfct->use); |
| 1236 | } |
| 1237 | static inline void nf_reset(struct sk_buff *skb) |
| 1238 | { |
| 1239 | nf_conntrack_put(skb->nfct); |
| 1240 | skb->nfct = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1241 | } |
| 1242 | |
| 1243 | #ifdef CONFIG_BRIDGE_NETFILTER |
| 1244 | static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge) |
| 1245 | { |
| 1246 | if (nf_bridge && atomic_dec_and_test(&nf_bridge->use)) |
| 1247 | kfree(nf_bridge); |
| 1248 | } |
| 1249 | static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge) |
| 1250 | { |
| 1251 | if (nf_bridge) |
| 1252 | atomic_inc(&nf_bridge->use); |
| 1253 | } |
| 1254 | #endif /* CONFIG_BRIDGE_NETFILTER */ |
| 1255 | #else /* CONFIG_NETFILTER */ |
| 1256 | static inline void nf_reset(struct sk_buff *skb) {} |
| 1257 | #endif /* CONFIG_NETFILTER */ |
| 1258 | |
| 1259 | #endif /* __KERNEL__ */ |
| 1260 | #endif /* _LINUX_SKBUFF_H */ |