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1da177e4 LT |
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> | |
30 | #include <net/checksum.h> | |
31 | ||
32 | #define HAVE_ALLOC_SKB /* For the drivers to know */ | |
33 | #define HAVE_ALIGNABLE_SKB /* Ditto 8) */ | |
34 | #define SLAB_SKB /* Slabified skbuffs */ | |
35 | ||
36 | #define CHECKSUM_NONE 0 | |
37 | #define CHECKSUM_HW 1 | |
38 | #define CHECKSUM_UNNECESSARY 2 | |
39 | ||
40 | #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \ | |
41 | ~(SMP_CACHE_BYTES - 1)) | |
42 | #define SKB_MAX_ORDER(X, ORDER) (((PAGE_SIZE << (ORDER)) - (X) - \ | |
43 | sizeof(struct skb_shared_info)) & \ | |
44 | ~(SMP_CACHE_BYTES - 1)) | |
45 | #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0)) | |
46 | #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2)) | |
47 | ||
48 | /* A. Checksumming of received packets by device. | |
49 | * | |
50 | * NONE: device failed to checksum this packet. | |
51 | * skb->csum is undefined. | |
52 | * | |
53 | * UNNECESSARY: device parsed packet and wouldbe verified checksum. | |
54 | * skb->csum is undefined. | |
55 | * It is bad option, but, unfortunately, many of vendors do this. | |
56 | * Apparently with secret goal to sell you new device, when you | |
57 | * will add new protocol to your host. F.e. IPv6. 8) | |
58 | * | |
59 | * HW: the most generic way. Device supplied checksum of _all_ | |
60 | * the packet as seen by netif_rx in skb->csum. | |
61 | * NOTE: Even if device supports only some protocols, but | |
62 | * is able to produce some skb->csum, it MUST use HW, | |
63 | * not UNNECESSARY. | |
64 | * | |
65 | * B. Checksumming on output. | |
66 | * | |
67 | * NONE: skb is checksummed by protocol or csum is not required. | |
68 | * | |
69 | * HW: device is required to csum packet as seen by hard_start_xmit | |
70 | * from skb->h.raw to the end and to record the checksum | |
71 | * at skb->h.raw+skb->csum. | |
72 | * | |
73 | * Device must show its capabilities in dev->features, set | |
74 | * at device setup time. | |
75 | * NETIF_F_HW_CSUM - it is clever device, it is able to checksum | |
76 | * everything. | |
77 | * NETIF_F_NO_CSUM - loopback or reliable single hop media. | |
78 | * NETIF_F_IP_CSUM - device is dumb. It is able to csum only | |
79 | * TCP/UDP over IPv4. Sigh. Vendors like this | |
80 | * way by an unknown reason. Though, see comment above | |
81 | * about CHECKSUM_UNNECESSARY. 8) | |
82 | * | |
83 | * Any questions? No questions, good. --ANK | |
84 | */ | |
85 | ||
86 | #ifdef __i386__ | |
87 | #define NET_CALLER(arg) (*(((void **)&arg) - 1)) | |
88 | #else | |
89 | #define NET_CALLER(arg) __builtin_return_address(0) | |
90 | #endif | |
91 | ||
92 | struct net_device; | |
93 | ||
94 | #ifdef CONFIG_NETFILTER | |
95 | struct nf_conntrack { | |
96 | atomic_t use; | |
97 | void (*destroy)(struct nf_conntrack *); | |
98 | }; | |
99 | ||
100 | #ifdef CONFIG_BRIDGE_NETFILTER | |
101 | struct nf_bridge_info { | |
102 | atomic_t use; | |
103 | struct net_device *physindev; | |
104 | struct net_device *physoutdev; | |
105 | #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE) | |
106 | struct net_device *netoutdev; | |
107 | #endif | |
108 | unsigned int mask; | |
109 | unsigned long data[32 / sizeof(unsigned long)]; | |
110 | }; | |
111 | #endif | |
112 | ||
113 | #endif | |
114 | ||
115 | struct sk_buff_head { | |
116 | /* These two members must be first. */ | |
117 | struct sk_buff *next; | |
118 | struct sk_buff *prev; | |
119 | ||
120 | __u32 qlen; | |
121 | spinlock_t lock; | |
122 | }; | |
123 | ||
124 | struct sk_buff; | |
125 | ||
126 | /* To allow 64K frame to be packed as single skb without frag_list */ | |
127 | #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2) | |
128 | ||
129 | typedef struct skb_frag_struct skb_frag_t; | |
130 | ||
131 | struct skb_frag_struct { | |
132 | struct page *page; | |
133 | __u16 page_offset; | |
134 | __u16 size; | |
135 | }; | |
136 | ||
137 | /* This data is invariant across clones and lives at | |
138 | * the end of the header data, ie. at skb->end. | |
139 | */ | |
140 | struct skb_shared_info { | |
141 | atomic_t dataref; | |
142 | unsigned int nr_frags; | |
143 | unsigned short tso_size; | |
144 | unsigned short tso_segs; | |
145 | struct sk_buff *frag_list; | |
146 | skb_frag_t frags[MAX_SKB_FRAGS]; | |
147 | }; | |
148 | ||
149 | /* We divide dataref into two halves. The higher 16 bits hold references | |
150 | * to the payload part of skb->data. The lower 16 bits hold references to | |
151 | * the entire skb->data. It is up to the users of the skb to agree on | |
152 | * where the payload starts. | |
153 | * | |
154 | * All users must obey the rule that the skb->data reference count must be | |
155 | * greater than or equal to the payload reference count. | |
156 | * | |
157 | * Holding a reference to the payload part means that the user does not | |
158 | * care about modifications to the header part of skb->data. | |
159 | */ | |
160 | #define SKB_DATAREF_SHIFT 16 | |
161 | #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) | |
162 | ||
163 | /** | |
164 | * struct sk_buff - socket buffer | |
165 | * @next: Next buffer in list | |
166 | * @prev: Previous buffer in list | |
167 | * @list: List we are on | |
168 | * @sk: Socket we are owned by | |
169 | * @stamp: Time we arrived | |
170 | * @dev: Device we arrived on/are leaving by | |
171 | * @input_dev: Device we arrived on | |
172 | * @real_dev: The real device we are using | |
173 | * @h: Transport layer header | |
174 | * @nh: Network layer header | |
175 | * @mac: Link layer header | |
176 | * @dst: FIXME: Describe this field | |
177 | * @cb: Control buffer. Free for use by every layer. Put private vars here | |
178 | * @len: Length of actual data | |
179 | * @data_len: Data length | |
180 | * @mac_len: Length of link layer header | |
181 | * @csum: Checksum | |
182 | * @__unused: Dead field, may be reused | |
183 | * @cloned: Head may be cloned (check refcnt to be sure) | |
184 | * @nohdr: Payload reference only, must not modify header | |
185 | * @pkt_type: Packet class | |
186 | * @ip_summed: Driver fed us an IP checksum | |
187 | * @priority: Packet queueing priority | |
188 | * @users: User count - see {datagram,tcp}.c | |
189 | * @protocol: Packet protocol from driver | |
190 | * @security: Security level of packet | |
191 | * @truesize: Buffer size | |
192 | * @head: Head of buffer | |
193 | * @data: Data head pointer | |
194 | * @tail: Tail pointer | |
195 | * @end: End pointer | |
196 | * @destructor: Destruct function | |
197 | * @nfmark: Can be used for communication between hooks | |
198 | * @nfcache: Cache info | |
199 | * @nfct: Associated connection, if any | |
200 | * @nfctinfo: Relationship of this skb to the connection | |
201 | * @nf_debug: Netfilter debugging | |
202 | * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c | |
203 | * @private: Data which is private to the HIPPI implementation | |
204 | * @tc_index: Traffic control index | |
205 | * @tc_verd: traffic control verdict | |
206 | * @tc_classid: traffic control classid | |
207 | */ | |
208 | ||
209 | struct sk_buff { | |
210 | /* These two members must be first. */ | |
211 | struct sk_buff *next; | |
212 | struct sk_buff *prev; | |
213 | ||
214 | struct sk_buff_head *list; | |
215 | struct sock *sk; | |
216 | struct timeval stamp; | |
217 | struct net_device *dev; | |
218 | struct net_device *input_dev; | |
219 | struct net_device *real_dev; | |
220 | ||
221 | union { | |
222 | struct tcphdr *th; | |
223 | struct udphdr *uh; | |
224 | struct icmphdr *icmph; | |
225 | struct igmphdr *igmph; | |
226 | struct iphdr *ipiph; | |
227 | struct ipv6hdr *ipv6h; | |
228 | unsigned char *raw; | |
229 | } h; | |
230 | ||
231 | union { | |
232 | struct iphdr *iph; | |
233 | struct ipv6hdr *ipv6h; | |
234 | struct arphdr *arph; | |
235 | unsigned char *raw; | |
236 | } nh; | |
237 | ||
238 | union { | |
239 | unsigned char *raw; | |
240 | } mac; | |
241 | ||
242 | struct dst_entry *dst; | |
243 | struct sec_path *sp; | |
244 | ||
245 | /* | |
246 | * This is the control buffer. It is free to use for every | |
247 | * layer. Please put your private variables there. If you | |
248 | * want to keep them across layers you have to do a skb_clone() | |
249 | * first. This is owned by whoever has the skb queued ATM. | |
250 | */ | |
251 | char cb[40]; | |
252 | ||
253 | unsigned int len, | |
254 | data_len, | |
255 | mac_len, | |
256 | csum; | |
257 | unsigned char local_df, | |
258 | cloned:1, | |
259 | nohdr:1, | |
260 | pkt_type, | |
261 | ip_summed; | |
262 | __u32 priority; | |
263 | unsigned short protocol, | |
264 | security; | |
265 | ||
266 | void (*destructor)(struct sk_buff *skb); | |
267 | #ifdef CONFIG_NETFILTER | |
268 | unsigned long nfmark; | |
269 | __u32 nfcache; | |
270 | __u32 nfctinfo; | |
271 | struct nf_conntrack *nfct; | |
272 | #ifdef CONFIG_NETFILTER_DEBUG | |
273 | unsigned int nf_debug; | |
274 | #endif | |
275 | #ifdef CONFIG_BRIDGE_NETFILTER | |
276 | struct nf_bridge_info *nf_bridge; | |
277 | #endif | |
278 | #endif /* CONFIG_NETFILTER */ | |
279 | #if defined(CONFIG_HIPPI) | |
280 | union { | |
281 | __u32 ifield; | |
282 | } private; | |
283 | #endif | |
284 | #ifdef CONFIG_NET_SCHED | |
285 | __u32 tc_index; /* traffic control index */ | |
286 | #ifdef CONFIG_NET_CLS_ACT | |
287 | __u32 tc_verd; /* traffic control verdict */ | |
288 | __u32 tc_classid; /* traffic control classid */ | |
289 | #endif | |
290 | ||
291 | #endif | |
292 | ||
293 | ||
294 | /* These elements must be at the end, see alloc_skb() for details. */ | |
295 | unsigned int truesize; | |
296 | atomic_t users; | |
297 | unsigned char *head, | |
298 | *data, | |
299 | *tail, | |
300 | *end; | |
301 | }; | |
302 | ||
303 | #ifdef __KERNEL__ | |
304 | /* | |
305 | * Handling routines are only of interest to the kernel | |
306 | */ | |
307 | #include <linux/slab.h> | |
308 | ||
309 | #include <asm/system.h> | |
310 | ||
311 | extern void __kfree_skb(struct sk_buff *skb); | |
312 | extern struct sk_buff *alloc_skb(unsigned int size, int priority); | |
313 | extern struct sk_buff *alloc_skb_from_cache(kmem_cache_t *cp, | |
314 | unsigned int size, int priority); | |
315 | extern void kfree_skbmem(struct sk_buff *skb); | |
316 | extern struct sk_buff *skb_clone(struct sk_buff *skb, int priority); | |
317 | extern struct sk_buff *skb_copy(const struct sk_buff *skb, int priority); | |
318 | extern struct sk_buff *pskb_copy(struct sk_buff *skb, int gfp_mask); | |
319 | extern int pskb_expand_head(struct sk_buff *skb, | |
320 | int nhead, int ntail, int gfp_mask); | |
321 | extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, | |
322 | unsigned int headroom); | |
323 | extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb, | |
324 | int newheadroom, int newtailroom, | |
325 | int priority); | |
326 | extern struct sk_buff * skb_pad(struct sk_buff *skb, int pad); | |
327 | #define dev_kfree_skb(a) kfree_skb(a) | |
328 | extern void skb_over_panic(struct sk_buff *skb, int len, | |
329 | void *here); | |
330 | extern void skb_under_panic(struct sk_buff *skb, int len, | |
331 | void *here); | |
332 | ||
333 | /* Internal */ | |
334 | #define skb_shinfo(SKB) ((struct skb_shared_info *)((SKB)->end)) | |
335 | ||
336 | /** | |
337 | * skb_queue_empty - check if a queue is empty | |
338 | * @list: queue head | |
339 | * | |
340 | * Returns true if the queue is empty, false otherwise. | |
341 | */ | |
342 | static inline int skb_queue_empty(const struct sk_buff_head *list) | |
343 | { | |
344 | return list->next == (struct sk_buff *)list; | |
345 | } | |
346 | ||
347 | /** | |
348 | * skb_get - reference buffer | |
349 | * @skb: buffer to reference | |
350 | * | |
351 | * Makes another reference to a socket buffer and returns a pointer | |
352 | * to the buffer. | |
353 | */ | |
354 | static inline struct sk_buff *skb_get(struct sk_buff *skb) | |
355 | { | |
356 | atomic_inc(&skb->users); | |
357 | return skb; | |
358 | } | |
359 | ||
360 | /* | |
361 | * If users == 1, we are the only owner and are can avoid redundant | |
362 | * atomic change. | |
363 | */ | |
364 | ||
365 | /** | |
366 | * kfree_skb - free an sk_buff | |
367 | * @skb: buffer to free | |
368 | * | |
369 | * Drop a reference to the buffer and free it if the usage count has | |
370 | * hit zero. | |
371 | */ | |
372 | static inline void kfree_skb(struct sk_buff *skb) | |
373 | { | |
374 | if (likely(atomic_read(&skb->users) == 1)) | |
375 | smp_rmb(); | |
376 | else if (likely(!atomic_dec_and_test(&skb->users))) | |
377 | return; | |
378 | __kfree_skb(skb); | |
379 | } | |
380 | ||
381 | /** | |
382 | * skb_cloned - is the buffer a clone | |
383 | * @skb: buffer to check | |
384 | * | |
385 | * Returns true if the buffer was generated with skb_clone() and is | |
386 | * one of multiple shared copies of the buffer. Cloned buffers are | |
387 | * shared data so must not be written to under normal circumstances. | |
388 | */ | |
389 | static inline int skb_cloned(const struct sk_buff *skb) | |
390 | { | |
391 | return skb->cloned && | |
392 | (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1; | |
393 | } | |
394 | ||
395 | /** | |
396 | * skb_header_cloned - is the header a clone | |
397 | * @skb: buffer to check | |
398 | * | |
399 | * Returns true if modifying the header part of the buffer requires | |
400 | * the data to be copied. | |
401 | */ | |
402 | static inline int skb_header_cloned(const struct sk_buff *skb) | |
403 | { | |
404 | int dataref; | |
405 | ||
406 | if (!skb->cloned) | |
407 | return 0; | |
408 | ||
409 | dataref = atomic_read(&skb_shinfo(skb)->dataref); | |
410 | dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT); | |
411 | return dataref != 1; | |
412 | } | |
413 | ||
414 | /** | |
415 | * skb_header_release - release reference to header | |
416 | * @skb: buffer to operate on | |
417 | * | |
418 | * Drop a reference to the header part of the buffer. This is done | |
419 | * by acquiring a payload reference. You must not read from the header | |
420 | * part of skb->data after this. | |
421 | */ | |
422 | static inline void skb_header_release(struct sk_buff *skb) | |
423 | { | |
424 | BUG_ON(skb->nohdr); | |
425 | skb->nohdr = 1; | |
426 | atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref); | |
427 | } | |
428 | ||
429 | /** | |
430 | * skb_shared - is the buffer shared | |
431 | * @skb: buffer to check | |
432 | * | |
433 | * Returns true if more than one person has a reference to this | |
434 | * buffer. | |
435 | */ | |
436 | static inline int skb_shared(const struct sk_buff *skb) | |
437 | { | |
438 | return atomic_read(&skb->users) != 1; | |
439 | } | |
440 | ||
441 | /** | |
442 | * skb_share_check - check if buffer is shared and if so clone it | |
443 | * @skb: buffer to check | |
444 | * @pri: priority for memory allocation | |
445 | * | |
446 | * If the buffer is shared the buffer is cloned and the old copy | |
447 | * drops a reference. A new clone with a single reference is returned. | |
448 | * If the buffer is not shared the original buffer is returned. When | |
449 | * being called from interrupt status or with spinlocks held pri must | |
450 | * be GFP_ATOMIC. | |
451 | * | |
452 | * NULL is returned on a memory allocation failure. | |
453 | */ | |
454 | static inline struct sk_buff *skb_share_check(struct sk_buff *skb, int pri) | |
455 | { | |
456 | might_sleep_if(pri & __GFP_WAIT); | |
457 | if (skb_shared(skb)) { | |
458 | struct sk_buff *nskb = skb_clone(skb, pri); | |
459 | kfree_skb(skb); | |
460 | skb = nskb; | |
461 | } | |
462 | return skb; | |
463 | } | |
464 | ||
465 | /* | |
466 | * Copy shared buffers into a new sk_buff. We effectively do COW on | |
467 | * packets to handle cases where we have a local reader and forward | |
468 | * and a couple of other messy ones. The normal one is tcpdumping | |
469 | * a packet thats being forwarded. | |
470 | */ | |
471 | ||
472 | /** | |
473 | * skb_unshare - make a copy of a shared buffer | |
474 | * @skb: buffer to check | |
475 | * @pri: priority for memory allocation | |
476 | * | |
477 | * If the socket buffer is a clone then this function creates a new | |
478 | * copy of the data, drops a reference count on the old copy and returns | |
479 | * the new copy with the reference count at 1. If the buffer is not a clone | |
480 | * the original buffer is returned. When called with a spinlock held or | |
481 | * from interrupt state @pri must be %GFP_ATOMIC | |
482 | * | |
483 | * %NULL is returned on a memory allocation failure. | |
484 | */ | |
485 | static inline struct sk_buff *skb_unshare(struct sk_buff *skb, int pri) | |
486 | { | |
487 | might_sleep_if(pri & __GFP_WAIT); | |
488 | if (skb_cloned(skb)) { | |
489 | struct sk_buff *nskb = skb_copy(skb, pri); | |
490 | kfree_skb(skb); /* Free our shared copy */ | |
491 | skb = nskb; | |
492 | } | |
493 | return skb; | |
494 | } | |
495 | ||
496 | /** | |
497 | * skb_peek | |
498 | * @list_: list to peek at | |
499 | * | |
500 | * Peek an &sk_buff. Unlike most other operations you _MUST_ | |
501 | * be careful with this one. A peek leaves the buffer on the | |
502 | * list and someone else may run off with it. You must hold | |
503 | * the appropriate locks or have a private queue to do this. | |
504 | * | |
505 | * Returns %NULL for an empty list or a pointer to the head element. | |
506 | * The reference count is not incremented and the reference is therefore | |
507 | * volatile. Use with caution. | |
508 | */ | |
509 | static inline struct sk_buff *skb_peek(struct sk_buff_head *list_) | |
510 | { | |
511 | struct sk_buff *list = ((struct sk_buff *)list_)->next; | |
512 | if (list == (struct sk_buff *)list_) | |
513 | list = NULL; | |
514 | return list; | |
515 | } | |
516 | ||
517 | /** | |
518 | * skb_peek_tail | |
519 | * @list_: list to peek at | |
520 | * | |
521 | * Peek an &sk_buff. Unlike most other operations you _MUST_ | |
522 | * be careful with this one. A peek leaves the buffer on the | |
523 | * list and someone else may run off with it. You must hold | |
524 | * the appropriate locks or have a private queue to do this. | |
525 | * | |
526 | * Returns %NULL for an empty list or a pointer to the tail element. | |
527 | * The reference count is not incremented and the reference is therefore | |
528 | * volatile. Use with caution. | |
529 | */ | |
530 | static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_) | |
531 | { | |
532 | struct sk_buff *list = ((struct sk_buff *)list_)->prev; | |
533 | if (list == (struct sk_buff *)list_) | |
534 | list = NULL; | |
535 | return list; | |
536 | } | |
537 | ||
538 | /** | |
539 | * skb_queue_len - get queue length | |
540 | * @list_: list to measure | |
541 | * | |
542 | * Return the length of an &sk_buff queue. | |
543 | */ | |
544 | static inline __u32 skb_queue_len(const struct sk_buff_head *list_) | |
545 | { | |
546 | return list_->qlen; | |
547 | } | |
548 | ||
549 | static inline void skb_queue_head_init(struct sk_buff_head *list) | |
550 | { | |
551 | spin_lock_init(&list->lock); | |
552 | list->prev = list->next = (struct sk_buff *)list; | |
553 | list->qlen = 0; | |
554 | } | |
555 | ||
556 | /* | |
557 | * Insert an sk_buff at the start of a list. | |
558 | * | |
559 | * The "__skb_xxxx()" functions are the non-atomic ones that | |
560 | * can only be called with interrupts disabled. | |
561 | */ | |
562 | ||
563 | /** | |
564 | * __skb_queue_head - queue a buffer at the list head | |
565 | * @list: list to use | |
566 | * @newsk: buffer to queue | |
567 | * | |
568 | * Queue a buffer at the start of a list. This function takes no locks | |
569 | * and you must therefore hold required locks before calling it. | |
570 | * | |
571 | * A buffer cannot be placed on two lists at the same time. | |
572 | */ | |
573 | extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); | |
574 | static inline void __skb_queue_head(struct sk_buff_head *list, | |
575 | struct sk_buff *newsk) | |
576 | { | |
577 | struct sk_buff *prev, *next; | |
578 | ||
579 | newsk->list = list; | |
580 | list->qlen++; | |
581 | prev = (struct sk_buff *)list; | |
582 | next = prev->next; | |
583 | newsk->next = next; | |
584 | newsk->prev = prev; | |
585 | next->prev = prev->next = newsk; | |
586 | } | |
587 | ||
588 | /** | |
589 | * __skb_queue_tail - queue a buffer at the list tail | |
590 | * @list: list to use | |
591 | * @newsk: buffer to queue | |
592 | * | |
593 | * Queue a buffer at the end of a list. This function takes no locks | |
594 | * and you must therefore hold required locks before calling it. | |
595 | * | |
596 | * A buffer cannot be placed on two lists at the same time. | |
597 | */ | |
598 | extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk); | |
599 | static inline void __skb_queue_tail(struct sk_buff_head *list, | |
600 | struct sk_buff *newsk) | |
601 | { | |
602 | struct sk_buff *prev, *next; | |
603 | ||
604 | newsk->list = list; | |
605 | list->qlen++; | |
606 | next = (struct sk_buff *)list; | |
607 | prev = next->prev; | |
608 | newsk->next = next; | |
609 | newsk->prev = prev; | |
610 | next->prev = prev->next = newsk; | |
611 | } | |
612 | ||
613 | ||
614 | /** | |
615 | * __skb_dequeue - remove from the head of the queue | |
616 | * @list: list to dequeue from | |
617 | * | |
618 | * Remove the head of the list. This function does not take any locks | |
619 | * so must be used with appropriate locks held only. The head item is | |
620 | * returned or %NULL if the list is empty. | |
621 | */ | |
622 | extern struct sk_buff *skb_dequeue(struct sk_buff_head *list); | |
623 | static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list) | |
624 | { | |
625 | struct sk_buff *next, *prev, *result; | |
626 | ||
627 | prev = (struct sk_buff *) list; | |
628 | next = prev->next; | |
629 | result = NULL; | |
630 | if (next != prev) { | |
631 | result = next; | |
632 | next = next->next; | |
633 | list->qlen--; | |
634 | next->prev = prev; | |
635 | prev->next = next; | |
636 | result->next = result->prev = NULL; | |
637 | result->list = NULL; | |
638 | } | |
639 | return result; | |
640 | } | |
641 | ||
642 | ||
643 | /* | |
644 | * Insert a packet on a list. | |
645 | */ | |
646 | extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk); | |
647 | static inline void __skb_insert(struct sk_buff *newsk, | |
648 | struct sk_buff *prev, struct sk_buff *next, | |
649 | struct sk_buff_head *list) | |
650 | { | |
651 | newsk->next = next; | |
652 | newsk->prev = prev; | |
653 | next->prev = prev->next = newsk; | |
654 | newsk->list = list; | |
655 | list->qlen++; | |
656 | } | |
657 | ||
658 | /* | |
659 | * Place a packet after a given packet in a list. | |
660 | */ | |
661 | extern void skb_append(struct sk_buff *old, struct sk_buff *newsk); | |
662 | static inline void __skb_append(struct sk_buff *old, struct sk_buff *newsk) | |
663 | { | |
664 | __skb_insert(newsk, old, old->next, old->list); | |
665 | } | |
666 | ||
667 | /* | |
668 | * remove sk_buff from list. _Must_ be called atomically, and with | |
669 | * the list known.. | |
670 | */ | |
671 | extern void skb_unlink(struct sk_buff *skb); | |
672 | static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) | |
673 | { | |
674 | struct sk_buff *next, *prev; | |
675 | ||
676 | list->qlen--; | |
677 | next = skb->next; | |
678 | prev = skb->prev; | |
679 | skb->next = skb->prev = NULL; | |
680 | skb->list = NULL; | |
681 | next->prev = prev; | |
682 | prev->next = next; | |
683 | } | |
684 | ||
685 | ||
686 | /* XXX: more streamlined implementation */ | |
687 | ||
688 | /** | |
689 | * __skb_dequeue_tail - remove from the tail of the queue | |
690 | * @list: list to dequeue from | |
691 | * | |
692 | * Remove the tail of the list. This function does not take any locks | |
693 | * so must be used with appropriate locks held only. The tail item is | |
694 | * returned or %NULL if the list is empty. | |
695 | */ | |
696 | extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list); | |
697 | static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list) | |
698 | { | |
699 | struct sk_buff *skb = skb_peek_tail(list); | |
700 | if (skb) | |
701 | __skb_unlink(skb, list); | |
702 | return skb; | |
703 | } | |
704 | ||
705 | ||
706 | static inline int skb_is_nonlinear(const struct sk_buff *skb) | |
707 | { | |
708 | return skb->data_len; | |
709 | } | |
710 | ||
711 | static inline unsigned int skb_headlen(const struct sk_buff *skb) | |
712 | { | |
713 | return skb->len - skb->data_len; | |
714 | } | |
715 | ||
716 | static inline int skb_pagelen(const struct sk_buff *skb) | |
717 | { | |
718 | int i, len = 0; | |
719 | ||
720 | for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) | |
721 | len += skb_shinfo(skb)->frags[i].size; | |
722 | return len + skb_headlen(skb); | |
723 | } | |
724 | ||
725 | static inline void skb_fill_page_desc(struct sk_buff *skb, int i, | |
726 | struct page *page, int off, int size) | |
727 | { | |
728 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
729 | ||
730 | frag->page = page; | |
731 | frag->page_offset = off; | |
732 | frag->size = size; | |
733 | skb_shinfo(skb)->nr_frags = i + 1; | |
734 | } | |
735 | ||
736 | #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags) | |
737 | #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list) | |
738 | #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) | |
739 | ||
740 | /* | |
741 | * Add data to an sk_buff | |
742 | */ | |
743 | static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len) | |
744 | { | |
745 | unsigned char *tmp = skb->tail; | |
746 | SKB_LINEAR_ASSERT(skb); | |
747 | skb->tail += len; | |
748 | skb->len += len; | |
749 | return tmp; | |
750 | } | |
751 | ||
752 | /** | |
753 | * skb_put - add data to a buffer | |
754 | * @skb: buffer to use | |
755 | * @len: amount of data to add | |
756 | * | |
757 | * This function extends the used data area of the buffer. If this would | |
758 | * exceed the total buffer size the kernel will panic. A pointer to the | |
759 | * first byte of the extra data is returned. | |
760 | */ | |
761 | static inline unsigned char *skb_put(struct sk_buff *skb, unsigned int len) | |
762 | { | |
763 | unsigned char *tmp = skb->tail; | |
764 | SKB_LINEAR_ASSERT(skb); | |
765 | skb->tail += len; | |
766 | skb->len += len; | |
767 | if (unlikely(skb->tail>skb->end)) | |
768 | skb_over_panic(skb, len, current_text_addr()); | |
769 | return tmp; | |
770 | } | |
771 | ||
772 | static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len) | |
773 | { | |
774 | skb->data -= len; | |
775 | skb->len += len; | |
776 | return skb->data; | |
777 | } | |
778 | ||
779 | /** | |
780 | * skb_push - add data to the start of a buffer | |
781 | * @skb: buffer to use | |
782 | * @len: amount of data to add | |
783 | * | |
784 | * This function extends the used data area of the buffer at the buffer | |
785 | * start. If this would exceed the total buffer headroom the kernel will | |
786 | * panic. A pointer to the first byte of the extra data is returned. | |
787 | */ | |
788 | static inline unsigned char *skb_push(struct sk_buff *skb, unsigned int len) | |
789 | { | |
790 | skb->data -= len; | |
791 | skb->len += len; | |
792 | if (unlikely(skb->data<skb->head)) | |
793 | skb_under_panic(skb, len, current_text_addr()); | |
794 | return skb->data; | |
795 | } | |
796 | ||
797 | static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len) | |
798 | { | |
799 | skb->len -= len; | |
800 | BUG_ON(skb->len < skb->data_len); | |
801 | return skb->data += len; | |
802 | } | |
803 | ||
804 | /** | |
805 | * skb_pull - remove data from the start of a buffer | |
806 | * @skb: buffer to use | |
807 | * @len: amount of data to remove | |
808 | * | |
809 | * This function removes data from the start of a buffer, returning | |
810 | * the memory to the headroom. A pointer to the next data in the buffer | |
811 | * is returned. Once the data has been pulled future pushes will overwrite | |
812 | * the old data. | |
813 | */ | |
814 | static inline unsigned char *skb_pull(struct sk_buff *skb, unsigned int len) | |
815 | { | |
816 | return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len); | |
817 | } | |
818 | ||
819 | extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta); | |
820 | ||
821 | static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len) | |
822 | { | |
823 | if (len > skb_headlen(skb) && | |
824 | !__pskb_pull_tail(skb, len-skb_headlen(skb))) | |
825 | return NULL; | |
826 | skb->len -= len; | |
827 | return skb->data += len; | |
828 | } | |
829 | ||
830 | static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len) | |
831 | { | |
832 | return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len); | |
833 | } | |
834 | ||
835 | static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len) | |
836 | { | |
837 | if (likely(len <= skb_headlen(skb))) | |
838 | return 1; | |
839 | if (unlikely(len > skb->len)) | |
840 | return 0; | |
841 | return __pskb_pull_tail(skb, len-skb_headlen(skb)) != NULL; | |
842 | } | |
843 | ||
844 | /** | |
845 | * skb_headroom - bytes at buffer head | |
846 | * @skb: buffer to check | |
847 | * | |
848 | * Return the number of bytes of free space at the head of an &sk_buff. | |
849 | */ | |
850 | static inline int skb_headroom(const struct sk_buff *skb) | |
851 | { | |
852 | return skb->data - skb->head; | |
853 | } | |
854 | ||
855 | /** | |
856 | * skb_tailroom - bytes at buffer end | |
857 | * @skb: buffer to check | |
858 | * | |
859 | * Return the number of bytes of free space at the tail of an sk_buff | |
860 | */ | |
861 | static inline int skb_tailroom(const struct sk_buff *skb) | |
862 | { | |
863 | return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail; | |
864 | } | |
865 | ||
866 | /** | |
867 | * skb_reserve - adjust headroom | |
868 | * @skb: buffer to alter | |
869 | * @len: bytes to move | |
870 | * | |
871 | * Increase the headroom of an empty &sk_buff by reducing the tail | |
872 | * room. This is only allowed for an empty buffer. | |
873 | */ | |
874 | static inline void skb_reserve(struct sk_buff *skb, unsigned int len) | |
875 | { | |
876 | skb->data += len; | |
877 | skb->tail += len; | |
878 | } | |
879 | ||
880 | /* | |
881 | * CPUs often take a performance hit when accessing unaligned memory | |
882 | * locations. The actual performance hit varies, it can be small if the | |
883 | * hardware handles it or large if we have to take an exception and fix it | |
884 | * in software. | |
885 | * | |
886 | * Since an ethernet header is 14 bytes network drivers often end up with | |
887 | * the IP header at an unaligned offset. The IP header can be aligned by | |
888 | * shifting the start of the packet by 2 bytes. Drivers should do this | |
889 | * with: | |
890 | * | |
891 | * skb_reserve(NET_IP_ALIGN); | |
892 | * | |
893 | * The downside to this alignment of the IP header is that the DMA is now | |
894 | * unaligned. On some architectures the cost of an unaligned DMA is high | |
895 | * and this cost outweighs the gains made by aligning the IP header. | |
896 | * | |
897 | * Since this trade off varies between architectures, we allow NET_IP_ALIGN | |
898 | * to be overridden. | |
899 | */ | |
900 | #ifndef NET_IP_ALIGN | |
901 | #define NET_IP_ALIGN 2 | |
902 | #endif | |
903 | ||
904 | extern int ___pskb_trim(struct sk_buff *skb, unsigned int len, int realloc); | |
905 | ||
906 | static inline void __skb_trim(struct sk_buff *skb, unsigned int len) | |
907 | { | |
908 | if (!skb->data_len) { | |
909 | skb->len = len; | |
910 | skb->tail = skb->data + len; | |
911 | } else | |
912 | ___pskb_trim(skb, len, 0); | |
913 | } | |
914 | ||
915 | /** | |
916 | * skb_trim - remove end from a buffer | |
917 | * @skb: buffer to alter | |
918 | * @len: new length | |
919 | * | |
920 | * Cut the length of a buffer down by removing data from the tail. If | |
921 | * the buffer is already under the length specified it is not modified. | |
922 | */ | |
923 | static inline void skb_trim(struct sk_buff *skb, unsigned int len) | |
924 | { | |
925 | if (skb->len > len) | |
926 | __skb_trim(skb, len); | |
927 | } | |
928 | ||
929 | ||
930 | static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) | |
931 | { | |
932 | if (!skb->data_len) { | |
933 | skb->len = len; | |
934 | skb->tail = skb->data+len; | |
935 | return 0; | |
936 | } | |
937 | return ___pskb_trim(skb, len, 1); | |
938 | } | |
939 | ||
940 | static inline int pskb_trim(struct sk_buff *skb, unsigned int len) | |
941 | { | |
942 | return (len < skb->len) ? __pskb_trim(skb, len) : 0; | |
943 | } | |
944 | ||
945 | /** | |
946 | * skb_orphan - orphan a buffer | |
947 | * @skb: buffer to orphan | |
948 | * | |
949 | * If a buffer currently has an owner then we call the owner's | |
950 | * destructor function and make the @skb unowned. The buffer continues | |
951 | * to exist but is no longer charged to its former owner. | |
952 | */ | |
953 | static inline void skb_orphan(struct sk_buff *skb) | |
954 | { | |
955 | if (skb->destructor) | |
956 | skb->destructor(skb); | |
957 | skb->destructor = NULL; | |
958 | skb->sk = NULL; | |
959 | } | |
960 | ||
961 | /** | |
962 | * __skb_queue_purge - empty a list | |
963 | * @list: list to empty | |
964 | * | |
965 | * Delete all buffers on an &sk_buff list. Each buffer is removed from | |
966 | * the list and one reference dropped. This function does not take the | |
967 | * list lock and the caller must hold the relevant locks to use it. | |
968 | */ | |
969 | extern void skb_queue_purge(struct sk_buff_head *list); | |
970 | static inline void __skb_queue_purge(struct sk_buff_head *list) | |
971 | { | |
972 | struct sk_buff *skb; | |
973 | while ((skb = __skb_dequeue(list)) != NULL) | |
974 | kfree_skb(skb); | |
975 | } | |
976 | ||
977 | /** | |
978 | * __dev_alloc_skb - allocate an skbuff for sending | |
979 | * @length: length to allocate | |
980 | * @gfp_mask: get_free_pages mask, passed to alloc_skb | |
981 | * | |
982 | * Allocate a new &sk_buff and assign it a usage count of one. The | |
983 | * buffer has unspecified headroom built in. Users should allocate | |
984 | * the headroom they think they need without accounting for the | |
985 | * built in space. The built in space is used for optimisations. | |
986 | * | |
987 | * %NULL is returned in there is no free memory. | |
988 | */ | |
989 | #ifndef CONFIG_HAVE_ARCH_DEV_ALLOC_SKB | |
990 | static inline struct sk_buff *__dev_alloc_skb(unsigned int length, | |
991 | int gfp_mask) | |
992 | { | |
993 | struct sk_buff *skb = alloc_skb(length + 16, gfp_mask); | |
994 | if (likely(skb)) | |
995 | skb_reserve(skb, 16); | |
996 | return skb; | |
997 | } | |
998 | #else | |
999 | extern struct sk_buff *__dev_alloc_skb(unsigned int length, int gfp_mask); | |
1000 | #endif | |
1001 | ||
1002 | /** | |
1003 | * dev_alloc_skb - allocate an skbuff for sending | |
1004 | * @length: length to allocate | |
1005 | * | |
1006 | * Allocate a new &sk_buff and assign it a usage count of one. The | |
1007 | * buffer has unspecified headroom built in. Users should allocate | |
1008 | * the headroom they think they need without accounting for the | |
1009 | * built in space. The built in space is used for optimisations. | |
1010 | * | |
1011 | * %NULL is returned in there is no free memory. Although this function | |
1012 | * allocates memory it can be called from an interrupt. | |
1013 | */ | |
1014 | static inline struct sk_buff *dev_alloc_skb(unsigned int length) | |
1015 | { | |
1016 | return __dev_alloc_skb(length, GFP_ATOMIC); | |
1017 | } | |
1018 | ||
1019 | /** | |
1020 | * skb_cow - copy header of skb when it is required | |
1021 | * @skb: buffer to cow | |
1022 | * @headroom: needed headroom | |
1023 | * | |
1024 | * If the skb passed lacks sufficient headroom or its data part | |
1025 | * is shared, data is reallocated. If reallocation fails, an error | |
1026 | * is returned and original skb is not changed. | |
1027 | * | |
1028 | * The result is skb with writable area skb->head...skb->tail | |
1029 | * and at least @headroom of space at head. | |
1030 | */ | |
1031 | static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) | |
1032 | { | |
1033 | int delta = (headroom > 16 ? headroom : 16) - skb_headroom(skb); | |
1034 | ||
1035 | if (delta < 0) | |
1036 | delta = 0; | |
1037 | ||
1038 | if (delta || skb_cloned(skb)) | |
1039 | return pskb_expand_head(skb, (delta + 15) & ~15, 0, GFP_ATOMIC); | |
1040 | return 0; | |
1041 | } | |
1042 | ||
1043 | /** | |
1044 | * skb_padto - pad an skbuff up to a minimal size | |
1045 | * @skb: buffer to pad | |
1046 | * @len: minimal length | |
1047 | * | |
1048 | * Pads up a buffer to ensure the trailing bytes exist and are | |
1049 | * blanked. If the buffer already contains sufficient data it | |
1050 | * is untouched. Returns the buffer, which may be a replacement | |
1051 | * for the original, or NULL for out of memory - in which case | |
1052 | * the original buffer is still freed. | |
1053 | */ | |
1054 | ||
1055 | static inline struct sk_buff *skb_padto(struct sk_buff *skb, unsigned int len) | |
1056 | { | |
1057 | unsigned int size = skb->len; | |
1058 | if (likely(size >= len)) | |
1059 | return skb; | |
1060 | return skb_pad(skb, len-size); | |
1061 | } | |
1062 | ||
1063 | static inline int skb_add_data(struct sk_buff *skb, | |
1064 | char __user *from, int copy) | |
1065 | { | |
1066 | const int off = skb->len; | |
1067 | ||
1068 | if (skb->ip_summed == CHECKSUM_NONE) { | |
1069 | int err = 0; | |
1070 | unsigned int csum = csum_and_copy_from_user(from, | |
1071 | skb_put(skb, copy), | |
1072 | copy, 0, &err); | |
1073 | if (!err) { | |
1074 | skb->csum = csum_block_add(skb->csum, csum, off); | |
1075 | return 0; | |
1076 | } | |
1077 | } else if (!copy_from_user(skb_put(skb, copy), from, copy)) | |
1078 | return 0; | |
1079 | ||
1080 | __skb_trim(skb, off); | |
1081 | return -EFAULT; | |
1082 | } | |
1083 | ||
1084 | static inline int skb_can_coalesce(struct sk_buff *skb, int i, | |
1085 | struct page *page, int off) | |
1086 | { | |
1087 | if (i) { | |
1088 | struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1]; | |
1089 | ||
1090 | return page == frag->page && | |
1091 | off == frag->page_offset + frag->size; | |
1092 | } | |
1093 | return 0; | |
1094 | } | |
1095 | ||
1096 | /** | |
1097 | * skb_linearize - convert paged skb to linear one | |
1098 | * @skb: buffer to linarize | |
1099 | * @gfp: allocation mode | |
1100 | * | |
1101 | * If there is no free memory -ENOMEM is returned, otherwise zero | |
1102 | * is returned and the old skb data released. | |
1103 | */ | |
1104 | extern int __skb_linearize(struct sk_buff *skb, int gfp); | |
1105 | static inline int skb_linearize(struct sk_buff *skb, int gfp) | |
1106 | { | |
1107 | return __skb_linearize(skb, gfp); | |
1108 | } | |
1109 | ||
1110 | /** | |
1111 | * skb_postpull_rcsum - update checksum for received skb after pull | |
1112 | * @skb: buffer to update | |
1113 | * @start: start of data before pull | |
1114 | * @len: length of data pulled | |
1115 | * | |
1116 | * After doing a pull on a received packet, you need to call this to | |
1117 | * update the CHECKSUM_HW checksum, or set ip_summed to CHECKSUM_NONE | |
1118 | * so that it can be recomputed from scratch. | |
1119 | */ | |
1120 | ||
1121 | static inline void skb_postpull_rcsum(struct sk_buff *skb, | |
1122 | const void *start, int len) | |
1123 | { | |
1124 | if (skb->ip_summed == CHECKSUM_HW) | |
1125 | skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0)); | |
1126 | } | |
1127 | ||
1128 | /** | |
1129 | * pskb_trim_rcsum - trim received skb and update checksum | |
1130 | * @skb: buffer to trim | |
1131 | * @len: new length | |
1132 | * | |
1133 | * This is exactly the same as pskb_trim except that it ensures the | |
1134 | * checksum of received packets are still valid after the operation. | |
1135 | */ | |
1136 | ||
1137 | static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len) | |
1138 | { | |
1139 | if (len >= skb->len) | |
1140 | return 0; | |
1141 | if (skb->ip_summed == CHECKSUM_HW) | |
1142 | skb->ip_summed = CHECKSUM_NONE; | |
1143 | return __pskb_trim(skb, len); | |
1144 | } | |
1145 | ||
1146 | static inline void *kmap_skb_frag(const skb_frag_t *frag) | |
1147 | { | |
1148 | #ifdef CONFIG_HIGHMEM | |
1149 | BUG_ON(in_irq()); | |
1150 | ||
1151 | local_bh_disable(); | |
1152 | #endif | |
1153 | return kmap_atomic(frag->page, KM_SKB_DATA_SOFTIRQ); | |
1154 | } | |
1155 | ||
1156 | static inline void kunmap_skb_frag(void *vaddr) | |
1157 | { | |
1158 | kunmap_atomic(vaddr, KM_SKB_DATA_SOFTIRQ); | |
1159 | #ifdef CONFIG_HIGHMEM | |
1160 | local_bh_enable(); | |
1161 | #endif | |
1162 | } | |
1163 | ||
1164 | #define skb_queue_walk(queue, skb) \ | |
1165 | for (skb = (queue)->next; \ | |
1166 | prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \ | |
1167 | skb = skb->next) | |
1168 | ||
1169 | ||
1170 | extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, | |
1171 | int noblock, int *err); | |
1172 | extern unsigned int datagram_poll(struct file *file, struct socket *sock, | |
1173 | struct poll_table_struct *wait); | |
1174 | extern int skb_copy_datagram_iovec(const struct sk_buff *from, | |
1175 | int offset, struct iovec *to, | |
1176 | int size); | |
1177 | extern int skb_copy_and_csum_datagram_iovec(const | |
1178 | struct sk_buff *skb, | |
1179 | int hlen, | |
1180 | struct iovec *iov); | |
1181 | extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb); | |
1182 | extern unsigned int skb_checksum(const struct sk_buff *skb, int offset, | |
1183 | int len, unsigned int csum); | |
1184 | extern int skb_copy_bits(const struct sk_buff *skb, int offset, | |
1185 | void *to, int len); | |
357b40a1 HX |
1186 | extern int skb_store_bits(const struct sk_buff *skb, int offset, |
1187 | void *from, int len); | |
1da177e4 LT |
1188 | extern unsigned int skb_copy_and_csum_bits(const struct sk_buff *skb, |
1189 | int offset, u8 *to, int len, | |
1190 | unsigned int csum); | |
1191 | extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); | |
1192 | extern void skb_split(struct sk_buff *skb, | |
1193 | struct sk_buff *skb1, const u32 len); | |
1194 | ||
1195 | static inline void *skb_header_pointer(const struct sk_buff *skb, int offset, | |
1196 | int len, void *buffer) | |
1197 | { | |
1198 | int hlen = skb_headlen(skb); | |
1199 | ||
1200 | if (offset + len <= hlen) | |
1201 | return skb->data + offset; | |
1202 | ||
1203 | if (skb_copy_bits(skb, offset, buffer, len) < 0) | |
1204 | return NULL; | |
1205 | ||
1206 | return buffer; | |
1207 | } | |
1208 | ||
1209 | extern void skb_init(void); | |
1210 | extern void skb_add_mtu(int mtu); | |
1211 | ||
1212 | #ifdef CONFIG_NETFILTER | |
1213 | static inline void nf_conntrack_put(struct nf_conntrack *nfct) | |
1214 | { | |
1215 | if (nfct && atomic_dec_and_test(&nfct->use)) | |
1216 | nfct->destroy(nfct); | |
1217 | } | |
1218 | static inline void nf_conntrack_get(struct nf_conntrack *nfct) | |
1219 | { | |
1220 | if (nfct) | |
1221 | atomic_inc(&nfct->use); | |
1222 | } | |
1223 | static inline void nf_reset(struct sk_buff *skb) | |
1224 | { | |
1225 | nf_conntrack_put(skb->nfct); | |
1226 | skb->nfct = NULL; | |
1227 | #ifdef CONFIG_NETFILTER_DEBUG | |
1228 | skb->nf_debug = 0; | |
1229 | #endif | |
1230 | } | |
1231 | static inline void nf_reset_debug(struct sk_buff *skb) | |
1232 | { | |
1233 | #ifdef CONFIG_NETFILTER_DEBUG | |
1234 | skb->nf_debug = 0; | |
1235 | #endif | |
1236 | } | |
1237 | ||
1238 | #ifdef CONFIG_BRIDGE_NETFILTER | |
1239 | static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge) | |
1240 | { | |
1241 | if (nf_bridge && atomic_dec_and_test(&nf_bridge->use)) | |
1242 | kfree(nf_bridge); | |
1243 | } | |
1244 | static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge) | |
1245 | { | |
1246 | if (nf_bridge) | |
1247 | atomic_inc(&nf_bridge->use); | |
1248 | } | |
1249 | #endif /* CONFIG_BRIDGE_NETFILTER */ | |
1250 | #else /* CONFIG_NETFILTER */ | |
1251 | static inline void nf_reset(struct sk_buff *skb) {} | |
1252 | #endif /* CONFIG_NETFILTER */ | |
1253 | ||
1254 | #endif /* __KERNEL__ */ | |
1255 | #endif /* _LINUX_SKBUFF_H */ |