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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/kernel.h> | |
18 | #include <linux/compiler.h> | |
19 | #include <linux/time.h> | |
20 | #include <linux/cache.h> | |
21 | ||
22 | #include <asm/atomic.h> | |
23 | #include <asm/types.h> | |
24 | #include <linux/spinlock.h> | |
25 | #include <linux/net.h> | |
26 | #include <linux/textsearch.h> | |
27 | #include <net/checksum.h> | |
28 | #include <linux/rcupdate.h> | |
29 | #include <linux/dmaengine.h> | |
30 | #include <linux/hrtimer.h> | |
31 | ||
32 | /* Don't change this without changing skb_csum_unnecessary! */ | |
33 | #define CHECKSUM_NONE 0 | |
34 | #define CHECKSUM_UNNECESSARY 1 | |
35 | #define CHECKSUM_COMPLETE 2 | |
36 | #define CHECKSUM_PARTIAL 3 | |
37 | ||
38 | #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \ | |
39 | ~(SMP_CACHE_BYTES - 1)) | |
40 | #define SKB_WITH_OVERHEAD(X) \ | |
41 | ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) | |
42 | #define SKB_MAX_ORDER(X, ORDER) \ | |
43 | SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X)) | |
44 | #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0)) | |
45 | #define SKB_MAX_ALLOC (SKB_MAX_ORDER(0, 2)) | |
46 | ||
47 | /* A. Checksumming of received packets by device. | |
48 | * | |
49 | * NONE: device failed to checksum this packet. | |
50 | * skb->csum is undefined. | |
51 | * | |
52 | * UNNECESSARY: device parsed packet and wouldbe verified checksum. | |
53 | * skb->csum is undefined. | |
54 | * It is bad option, but, unfortunately, many of vendors do this. | |
55 | * Apparently with secret goal to sell you new device, when you | |
56 | * will add new protocol to your host. F.e. IPv6. 8) | |
57 | * | |
58 | * COMPLETE: the most generic way. Device supplied checksum of _all_ | |
59 | * the packet as seen by netif_rx in skb->csum. | |
60 | * NOTE: Even if device supports only some protocols, but | |
61 | * is able to produce some skb->csum, it MUST use COMPLETE, | |
62 | * not UNNECESSARY. | |
63 | * | |
64 | * PARTIAL: identical to the case for output below. This may occur | |
65 | * on a packet received directly from another Linux OS, e.g., | |
66 | * a virtualised Linux kernel on the same host. The packet can | |
67 | * be treated in the same way as UNNECESSARY except that on | |
68 | * output (i.e., forwarding) the checksum must be filled in | |
69 | * by the OS or the hardware. | |
70 | * | |
71 | * B. Checksumming on output. | |
72 | * | |
73 | * NONE: skb is checksummed by protocol or csum is not required. | |
74 | * | |
75 | * PARTIAL: device is required to csum packet as seen by hard_start_xmit | |
76 | * from skb->csum_start to the end and to record the checksum | |
77 | * at skb->csum_start + skb->csum_offset. | |
78 | * | |
79 | * Device must show its capabilities in dev->features, set | |
80 | * at device setup time. | |
81 | * NETIF_F_HW_CSUM - it is clever device, it is able to checksum | |
82 | * everything. | |
83 | * NETIF_F_NO_CSUM - loopback or reliable single hop media. | |
84 | * NETIF_F_IP_CSUM - device is dumb. It is able to csum only | |
85 | * TCP/UDP over IPv4. Sigh. Vendors like this | |
86 | * way by an unknown reason. Though, see comment above | |
87 | * about CHECKSUM_UNNECESSARY. 8) | |
88 | * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead. | |
89 | * | |
90 | * Any questions? No questions, good. --ANK | |
91 | */ | |
92 | ||
93 | struct net_device; | |
94 | struct scatterlist; | |
95 | struct pipe_inode_info; | |
96 | ||
97 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) | |
98 | struct nf_conntrack { | |
99 | atomic_t use; | |
100 | }; | |
101 | #endif | |
102 | ||
103 | #ifdef CONFIG_BRIDGE_NETFILTER | |
104 | struct nf_bridge_info { | |
105 | atomic_t use; | |
106 | struct net_device *physindev; | |
107 | struct net_device *physoutdev; | |
108 | unsigned int mask; | |
109 | unsigned long data[32 / sizeof(unsigned long)]; | |
110 | }; | |
111 | #endif | |
112 | ||
113 | struct sk_buff_head { | |
114 | /* These two members must be first. */ | |
115 | struct sk_buff *next; | |
116 | struct sk_buff *prev; | |
117 | ||
118 | __u32 qlen; | |
119 | spinlock_t lock; | |
120 | }; | |
121 | ||
122 | struct sk_buff; | |
123 | ||
124 | /* To allow 64K frame to be packed as single skb without frag_list */ | |
125 | #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2) | |
126 | ||
127 | typedef struct skb_frag_struct skb_frag_t; | |
128 | ||
129 | struct skb_frag_struct { | |
130 | struct page *page; | |
131 | __u32 page_offset; | |
132 | __u32 size; | |
133 | }; | |
134 | ||
135 | #define HAVE_HW_TIME_STAMP | |
136 | ||
137 | /** | |
138 | * struct skb_shared_hwtstamps - hardware time stamps | |
139 | * @hwtstamp: hardware time stamp transformed into duration | |
140 | * since arbitrary point in time | |
141 | * @syststamp: hwtstamp transformed to system time base | |
142 | * | |
143 | * Software time stamps generated by ktime_get_real() are stored in | |
144 | * skb->tstamp. The relation between the different kinds of time | |
145 | * stamps is as follows: | |
146 | * | |
147 | * syststamp and tstamp can be compared against each other in | |
148 | * arbitrary combinations. The accuracy of a | |
149 | * syststamp/tstamp/"syststamp from other device" comparison is | |
150 | * limited by the accuracy of the transformation into system time | |
151 | * base. This depends on the device driver and its underlying | |
152 | * hardware. | |
153 | * | |
154 | * hwtstamps can only be compared against other hwtstamps from | |
155 | * the same device. | |
156 | * | |
157 | * This structure is attached to packets as part of the | |
158 | * &skb_shared_info. Use skb_hwtstamps() to get a pointer. | |
159 | */ | |
160 | struct skb_shared_hwtstamps { | |
161 | ktime_t hwtstamp; | |
162 | ktime_t syststamp; | |
163 | }; | |
164 | ||
165 | /** | |
166 | * struct skb_shared_tx - instructions for time stamping of outgoing packets | |
167 | * @hardware: generate hardware time stamp | |
168 | * @software: generate software time stamp | |
169 | * @in_progress: device driver is going to provide | |
170 | * hardware time stamp | |
171 | * @flags: all shared_tx flags | |
172 | * | |
173 | * These flags are attached to packets as part of the | |
174 | * &skb_shared_info. Use skb_tx() to get a pointer. | |
175 | */ | |
176 | union skb_shared_tx { | |
177 | struct { | |
178 | __u8 hardware:1, | |
179 | software:1, | |
180 | in_progress:1; | |
181 | }; | |
182 | __u8 flags; | |
183 | }; | |
184 | ||
185 | /* This data is invariant across clones and lives at | |
186 | * the end of the header data, ie. at skb->end. | |
187 | */ | |
188 | struct skb_shared_info { | |
189 | atomic_t dataref; | |
190 | unsigned short nr_frags; | |
191 | unsigned short gso_size; | |
192 | /* Warning: this field is not always filled in (UFO)! */ | |
193 | unsigned short gso_segs; | |
194 | unsigned short gso_type; | |
195 | __be32 ip6_frag_id; | |
196 | union skb_shared_tx tx_flags; | |
197 | #ifdef CONFIG_HAS_DMA | |
198 | unsigned int num_dma_maps; | |
199 | #endif | |
200 | struct sk_buff *frag_list; | |
201 | struct skb_shared_hwtstamps hwtstamps; | |
202 | skb_frag_t frags[MAX_SKB_FRAGS]; | |
203 | #ifdef CONFIG_HAS_DMA | |
204 | dma_addr_t dma_maps[MAX_SKB_FRAGS + 1]; | |
205 | #endif | |
206 | }; | |
207 | ||
208 | /* We divide dataref into two halves. The higher 16 bits hold references | |
209 | * to the payload part of skb->data. The lower 16 bits hold references to | |
210 | * the entire skb->data. A clone of a headerless skb holds the length of | |
211 | * the header in skb->hdr_len. | |
212 | * | |
213 | * All users must obey the rule that the skb->data reference count must be | |
214 | * greater than or equal to the payload reference count. | |
215 | * | |
216 | * Holding a reference to the payload part means that the user does not | |
217 | * care about modifications to the header part of skb->data. | |
218 | */ | |
219 | #define SKB_DATAREF_SHIFT 16 | |
220 | #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) | |
221 | ||
222 | ||
223 | enum { | |
224 | SKB_FCLONE_UNAVAILABLE, | |
225 | SKB_FCLONE_ORIG, | |
226 | SKB_FCLONE_CLONE, | |
227 | }; | |
228 | ||
229 | enum { | |
230 | SKB_GSO_TCPV4 = 1 << 0, | |
231 | SKB_GSO_UDP = 1 << 1, | |
232 | ||
233 | /* This indicates the skb is from an untrusted source. */ | |
234 | SKB_GSO_DODGY = 1 << 2, | |
235 | ||
236 | /* This indicates the tcp segment has CWR set. */ | |
237 | SKB_GSO_TCP_ECN = 1 << 3, | |
238 | ||
239 | SKB_GSO_TCPV6 = 1 << 4, | |
240 | ||
241 | SKB_GSO_FCOE = 1 << 5, | |
242 | }; | |
243 | ||
244 | #if BITS_PER_LONG > 32 | |
245 | #define NET_SKBUFF_DATA_USES_OFFSET 1 | |
246 | #endif | |
247 | ||
248 | #ifdef NET_SKBUFF_DATA_USES_OFFSET | |
249 | typedef unsigned int sk_buff_data_t; | |
250 | #else | |
251 | typedef unsigned char *sk_buff_data_t; | |
252 | #endif | |
253 | ||
254 | /** | |
255 | * struct sk_buff - socket buffer | |
256 | * @next: Next buffer in list | |
257 | * @prev: Previous buffer in list | |
258 | * @sk: Socket we are owned by | |
259 | * @tstamp: Time we arrived | |
260 | * @dev: Device we arrived on/are leaving by | |
261 | * @transport_header: Transport layer header | |
262 | * @network_header: Network layer header | |
263 | * @mac_header: Link layer header | |
264 | * @dst: destination entry | |
265 | * @sp: the security path, used for xfrm | |
266 | * @cb: Control buffer. Free for use by every layer. Put private vars here | |
267 | * @len: Length of actual data | |
268 | * @data_len: Data length | |
269 | * @mac_len: Length of link layer header | |
270 | * @hdr_len: writable header length of cloned skb | |
271 | * @csum: Checksum (must include start/offset pair) | |
272 | * @csum_start: Offset from skb->head where checksumming should start | |
273 | * @csum_offset: Offset from csum_start where checksum should be stored | |
274 | * @local_df: allow local fragmentation | |
275 | * @cloned: Head may be cloned (check refcnt to be sure) | |
276 | * @nohdr: Payload reference only, must not modify header | |
277 | * @pkt_type: Packet class | |
278 | * @fclone: skbuff clone status | |
279 | * @ip_summed: Driver fed us an IP checksum | |
280 | * @priority: Packet queueing priority | |
281 | * @users: User count - see {datagram,tcp}.c | |
282 | * @protocol: Packet protocol from driver | |
283 | * @truesize: Buffer size | |
284 | * @head: Head of buffer | |
285 | * @data: Data head pointer | |
286 | * @tail: Tail pointer | |
287 | * @end: End pointer | |
288 | * @destructor: Destruct function | |
289 | * @mark: Generic packet mark | |
290 | * @nfct: Associated connection, if any | |
291 | * @ipvs_property: skbuff is owned by ipvs | |
292 | * @peeked: this packet has been seen already, so stats have been | |
293 | * done for it, don't do them again | |
294 | * @nf_trace: netfilter packet trace flag | |
295 | * @nfctinfo: Relationship of this skb to the connection | |
296 | * @nfct_reasm: netfilter conntrack re-assembly pointer | |
297 | * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c | |
298 | * @iif: ifindex of device we arrived on | |
299 | * @queue_mapping: Queue mapping for multiqueue devices | |
300 | * @tc_index: Traffic control index | |
301 | * @tc_verd: traffic control verdict | |
302 | * @ndisc_nodetype: router type (from link layer) | |
303 | * @do_not_encrypt: set to prevent encryption of this frame | |
304 | * @requeue: set to indicate that the wireless core should attempt | |
305 | * a software retry on this frame if we failed to | |
306 | * receive an ACK for it | |
307 | * @dma_cookie: a cookie to one of several possible DMA operations | |
308 | * done by skb DMA functions | |
309 | * @secmark: security marking | |
310 | * @vlan_tci: vlan tag control information | |
311 | */ | |
312 | ||
313 | struct sk_buff { | |
314 | /* These two members must be first. */ | |
315 | struct sk_buff *next; | |
316 | struct sk_buff *prev; | |
317 | ||
318 | struct sock *sk; | |
319 | ktime_t tstamp; | |
320 | struct net_device *dev; | |
321 | ||
322 | union { | |
323 | struct dst_entry *dst; | |
324 | struct rtable *rtable; | |
325 | }; | |
326 | #ifdef CONFIG_XFRM | |
327 | struct sec_path *sp; | |
328 | #endif | |
329 | /* | |
330 | * This is the control buffer. It is free to use for every | |
331 | * layer. Please put your private variables there. If you | |
332 | * want to keep them across layers you have to do a skb_clone() | |
333 | * first. This is owned by whoever has the skb queued ATM. | |
334 | */ | |
335 | char cb[48]; | |
336 | ||
337 | unsigned int len, | |
338 | data_len; | |
339 | __u16 mac_len, | |
340 | hdr_len; | |
341 | union { | |
342 | __wsum csum; | |
343 | struct { | |
344 | __u16 csum_start; | |
345 | __u16 csum_offset; | |
346 | }; | |
347 | }; | |
348 | __u32 priority; | |
349 | __u8 local_df:1, | |
350 | cloned:1, | |
351 | ip_summed:2, | |
352 | nohdr:1, | |
353 | nfctinfo:3; | |
354 | __u8 pkt_type:3, | |
355 | fclone:2, | |
356 | ipvs_property:1, | |
357 | peeked:1, | |
358 | nf_trace:1; | |
359 | __be16 protocol; | |
360 | ||
361 | void (*destructor)(struct sk_buff *skb); | |
362 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) | |
363 | struct nf_conntrack *nfct; | |
364 | struct sk_buff *nfct_reasm; | |
365 | #endif | |
366 | #ifdef CONFIG_BRIDGE_NETFILTER | |
367 | struct nf_bridge_info *nf_bridge; | |
368 | #endif | |
369 | ||
370 | int iif; | |
371 | __u16 queue_mapping; | |
372 | #ifdef CONFIG_NET_SCHED | |
373 | __u16 tc_index; /* traffic control index */ | |
374 | #ifdef CONFIG_NET_CLS_ACT | |
375 | __u16 tc_verd; /* traffic control verdict */ | |
376 | #endif | |
377 | #endif | |
378 | #ifdef CONFIG_IPV6_NDISC_NODETYPE | |
379 | __u8 ndisc_nodetype:2; | |
380 | #endif | |
381 | #if defined(CONFIG_MAC80211) || defined(CONFIG_MAC80211_MODULE) | |
382 | __u8 do_not_encrypt:1; | |
383 | __u8 requeue:1; | |
384 | #endif | |
385 | /* 0/13/14 bit hole */ | |
386 | ||
387 | #ifdef CONFIG_NET_DMA | |
388 | dma_cookie_t dma_cookie; | |
389 | #endif | |
390 | #ifdef CONFIG_NETWORK_SECMARK | |
391 | __u32 secmark; | |
392 | #endif | |
393 | ||
394 | __u32 mark; | |
395 | ||
396 | __u16 vlan_tci; | |
397 | ||
398 | sk_buff_data_t transport_header; | |
399 | sk_buff_data_t network_header; | |
400 | sk_buff_data_t mac_header; | |
401 | /* These elements must be at the end, see alloc_skb() for details. */ | |
402 | sk_buff_data_t tail; | |
403 | sk_buff_data_t end; | |
404 | unsigned char *head, | |
405 | *data; | |
406 | unsigned int truesize; | |
407 | atomic_t users; | |
408 | }; | |
409 | ||
410 | #ifdef __KERNEL__ | |
411 | /* | |
412 | * Handling routines are only of interest to the kernel | |
413 | */ | |
414 | #include <linux/slab.h> | |
415 | ||
416 | #include <asm/system.h> | |
417 | ||
418 | #ifdef CONFIG_HAS_DMA | |
419 | #include <linux/dma-mapping.h> | |
420 | extern int skb_dma_map(struct device *dev, struct sk_buff *skb, | |
421 | enum dma_data_direction dir); | |
422 | extern void skb_dma_unmap(struct device *dev, struct sk_buff *skb, | |
423 | enum dma_data_direction dir); | |
424 | #endif | |
425 | ||
426 | extern void kfree_skb(struct sk_buff *skb); | |
427 | extern void consume_skb(struct sk_buff *skb); | |
428 | extern void __kfree_skb(struct sk_buff *skb); | |
429 | extern struct sk_buff *__alloc_skb(unsigned int size, | |
430 | gfp_t priority, int fclone, int node); | |
431 | static inline struct sk_buff *alloc_skb(unsigned int size, | |
432 | gfp_t priority) | |
433 | { | |
434 | return __alloc_skb(size, priority, 0, -1); | |
435 | } | |
436 | ||
437 | static inline struct sk_buff *alloc_skb_fclone(unsigned int size, | |
438 | gfp_t priority) | |
439 | { | |
440 | return __alloc_skb(size, priority, 1, -1); | |
441 | } | |
442 | ||
443 | extern int skb_recycle_check(struct sk_buff *skb, int skb_size); | |
444 | ||
445 | extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src); | |
446 | extern struct sk_buff *skb_clone(struct sk_buff *skb, | |
447 | gfp_t priority); | |
448 | extern struct sk_buff *skb_copy(const struct sk_buff *skb, | |
449 | gfp_t priority); | |
450 | extern struct sk_buff *pskb_copy(struct sk_buff *skb, | |
451 | gfp_t gfp_mask); | |
452 | extern int pskb_expand_head(struct sk_buff *skb, | |
453 | int nhead, int ntail, | |
454 | gfp_t gfp_mask); | |
455 | extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, | |
456 | unsigned int headroom); | |
457 | extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb, | |
458 | int newheadroom, int newtailroom, | |
459 | gfp_t priority); | |
460 | extern int skb_to_sgvec(struct sk_buff *skb, | |
461 | struct scatterlist *sg, int offset, | |
462 | int len); | |
463 | extern int skb_cow_data(struct sk_buff *skb, int tailbits, | |
464 | struct sk_buff **trailer); | |
465 | extern int skb_pad(struct sk_buff *skb, int pad); | |
466 | #define dev_kfree_skb(a) consume_skb(a) | |
467 | #define dev_consume_skb(a) kfree_skb_clean(a) | |
468 | extern void skb_over_panic(struct sk_buff *skb, int len, | |
469 | void *here); | |
470 | extern void skb_under_panic(struct sk_buff *skb, int len, | |
471 | void *here); | |
472 | ||
473 | extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, | |
474 | int getfrag(void *from, char *to, int offset, | |
475 | int len,int odd, struct sk_buff *skb), | |
476 | void *from, int length); | |
477 | ||
478 | struct skb_seq_state | |
479 | { | |
480 | __u32 lower_offset; | |
481 | __u32 upper_offset; | |
482 | __u32 frag_idx; | |
483 | __u32 stepped_offset; | |
484 | struct sk_buff *root_skb; | |
485 | struct sk_buff *cur_skb; | |
486 | __u8 *frag_data; | |
487 | }; | |
488 | ||
489 | extern void skb_prepare_seq_read(struct sk_buff *skb, | |
490 | unsigned int from, unsigned int to, | |
491 | struct skb_seq_state *st); | |
492 | extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data, | |
493 | struct skb_seq_state *st); | |
494 | extern void skb_abort_seq_read(struct skb_seq_state *st); | |
495 | ||
496 | extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, | |
497 | unsigned int to, struct ts_config *config, | |
498 | struct ts_state *state); | |
499 | ||
500 | #ifdef NET_SKBUFF_DATA_USES_OFFSET | |
501 | static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) | |
502 | { | |
503 | return skb->head + skb->end; | |
504 | } | |
505 | #else | |
506 | static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) | |
507 | { | |
508 | return skb->end; | |
509 | } | |
510 | #endif | |
511 | ||
512 | /* Internal */ | |
513 | #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) | |
514 | ||
515 | static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb) | |
516 | { | |
517 | return &skb_shinfo(skb)->hwtstamps; | |
518 | } | |
519 | ||
520 | static inline union skb_shared_tx *skb_tx(struct sk_buff *skb) | |
521 | { | |
522 | return &skb_shinfo(skb)->tx_flags; | |
523 | } | |
524 | ||
525 | /** | |
526 | * skb_queue_empty - check if a queue is empty | |
527 | * @list: queue head | |
528 | * | |
529 | * Returns true if the queue is empty, false otherwise. | |
530 | */ | |
531 | static inline int skb_queue_empty(const struct sk_buff_head *list) | |
532 | { | |
533 | return list->next == (struct sk_buff *)list; | |
534 | } | |
535 | ||
536 | /** | |
537 | * skb_queue_is_last - check if skb is the last entry in the queue | |
538 | * @list: queue head | |
539 | * @skb: buffer | |
540 | * | |
541 | * Returns true if @skb is the last buffer on the list. | |
542 | */ | |
543 | static inline bool skb_queue_is_last(const struct sk_buff_head *list, | |
544 | const struct sk_buff *skb) | |
545 | { | |
546 | return (skb->next == (struct sk_buff *) list); | |
547 | } | |
548 | ||
549 | /** | |
550 | * skb_queue_is_first - check if skb is the first entry in the queue | |
551 | * @list: queue head | |
552 | * @skb: buffer | |
553 | * | |
554 | * Returns true if @skb is the first buffer on the list. | |
555 | */ | |
556 | static inline bool skb_queue_is_first(const struct sk_buff_head *list, | |
557 | const struct sk_buff *skb) | |
558 | { | |
559 | return (skb->prev == (struct sk_buff *) list); | |
560 | } | |
561 | ||
562 | /** | |
563 | * skb_queue_next - return the next packet in the queue | |
564 | * @list: queue head | |
565 | * @skb: current buffer | |
566 | * | |
567 | * Return the next packet in @list after @skb. It is only valid to | |
568 | * call this if skb_queue_is_last() evaluates to false. | |
569 | */ | |
570 | static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list, | |
571 | const struct sk_buff *skb) | |
572 | { | |
573 | /* This BUG_ON may seem severe, but if we just return then we | |
574 | * are going to dereference garbage. | |
575 | */ | |
576 | BUG_ON(skb_queue_is_last(list, skb)); | |
577 | return skb->next; | |
578 | } | |
579 | ||
580 | /** | |
581 | * skb_queue_prev - return the prev packet in the queue | |
582 | * @list: queue head | |
583 | * @skb: current buffer | |
584 | * | |
585 | * Return the prev packet in @list before @skb. It is only valid to | |
586 | * call this if skb_queue_is_first() evaluates to false. | |
587 | */ | |
588 | static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list, | |
589 | const struct sk_buff *skb) | |
590 | { | |
591 | /* This BUG_ON may seem severe, but if we just return then we | |
592 | * are going to dereference garbage. | |
593 | */ | |
594 | BUG_ON(skb_queue_is_first(list, skb)); | |
595 | return skb->prev; | |
596 | } | |
597 | ||
598 | /** | |
599 | * skb_get - reference buffer | |
600 | * @skb: buffer to reference | |
601 | * | |
602 | * Makes another reference to a socket buffer and returns a pointer | |
603 | * to the buffer. | |
604 | */ | |
605 | static inline struct sk_buff *skb_get(struct sk_buff *skb) | |
606 | { | |
607 | atomic_inc(&skb->users); | |
608 | return skb; | |
609 | } | |
610 | ||
611 | /* | |
612 | * If users == 1, we are the only owner and are can avoid redundant | |
613 | * atomic change. | |
614 | */ | |
615 | ||
616 | /** | |
617 | * skb_cloned - is the buffer a clone | |
618 | * @skb: buffer to check | |
619 | * | |
620 | * Returns true if the buffer was generated with skb_clone() and is | |
621 | * one of multiple shared copies of the buffer. Cloned buffers are | |
622 | * shared data so must not be written to under normal circumstances. | |
623 | */ | |
624 | static inline int skb_cloned(const struct sk_buff *skb) | |
625 | { | |
626 | return skb->cloned && | |
627 | (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1; | |
628 | } | |
629 | ||
630 | /** | |
631 | * skb_header_cloned - is the header a clone | |
632 | * @skb: buffer to check | |
633 | * | |
634 | * Returns true if modifying the header part of the buffer requires | |
635 | * the data to be copied. | |
636 | */ | |
637 | static inline int skb_header_cloned(const struct sk_buff *skb) | |
638 | { | |
639 | int dataref; | |
640 | ||
641 | if (!skb->cloned) | |
642 | return 0; | |
643 | ||
644 | dataref = atomic_read(&skb_shinfo(skb)->dataref); | |
645 | dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT); | |
646 | return dataref != 1; | |
647 | } | |
648 | ||
649 | /** | |
650 | * skb_header_release - release reference to header | |
651 | * @skb: buffer to operate on | |
652 | * | |
653 | * Drop a reference to the header part of the buffer. This is done | |
654 | * by acquiring a payload reference. You must not read from the header | |
655 | * part of skb->data after this. | |
656 | */ | |
657 | static inline void skb_header_release(struct sk_buff *skb) | |
658 | { | |
659 | BUG_ON(skb->nohdr); | |
660 | skb->nohdr = 1; | |
661 | atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref); | |
662 | } | |
663 | ||
664 | /** | |
665 | * skb_shared - is the buffer shared | |
666 | * @skb: buffer to check | |
667 | * | |
668 | * Returns true if more than one person has a reference to this | |
669 | * buffer. | |
670 | */ | |
671 | static inline int skb_shared(const struct sk_buff *skb) | |
672 | { | |
673 | return atomic_read(&skb->users) != 1; | |
674 | } | |
675 | ||
676 | /** | |
677 | * skb_share_check - check if buffer is shared and if so clone it | |
678 | * @skb: buffer to check | |
679 | * @pri: priority for memory allocation | |
680 | * | |
681 | * If the buffer is shared the buffer is cloned and the old copy | |
682 | * drops a reference. A new clone with a single reference is returned. | |
683 | * If the buffer is not shared the original buffer is returned. When | |
684 | * being called from interrupt status or with spinlocks held pri must | |
685 | * be GFP_ATOMIC. | |
686 | * | |
687 | * NULL is returned on a memory allocation failure. | |
688 | */ | |
689 | static inline struct sk_buff *skb_share_check(struct sk_buff *skb, | |
690 | gfp_t pri) | |
691 | { | |
692 | might_sleep_if(pri & __GFP_WAIT); | |
693 | if (skb_shared(skb)) { | |
694 | struct sk_buff *nskb = skb_clone(skb, pri); | |
695 | kfree_skb(skb); | |
696 | skb = nskb; | |
697 | } | |
698 | return skb; | |
699 | } | |
700 | ||
701 | /* | |
702 | * Copy shared buffers into a new sk_buff. We effectively do COW on | |
703 | * packets to handle cases where we have a local reader and forward | |
704 | * and a couple of other messy ones. The normal one is tcpdumping | |
705 | * a packet thats being forwarded. | |
706 | */ | |
707 | ||
708 | /** | |
709 | * skb_unshare - make a copy of a shared buffer | |
710 | * @skb: buffer to check | |
711 | * @pri: priority for memory allocation | |
712 | * | |
713 | * If the socket buffer is a clone then this function creates a new | |
714 | * copy of the data, drops a reference count on the old copy and returns | |
715 | * the new copy with the reference count at 1. If the buffer is not a clone | |
716 | * the original buffer is returned. When called with a spinlock held or | |
717 | * from interrupt state @pri must be %GFP_ATOMIC | |
718 | * | |
719 | * %NULL is returned on a memory allocation failure. | |
720 | */ | |
721 | static inline struct sk_buff *skb_unshare(struct sk_buff *skb, | |
722 | gfp_t pri) | |
723 | { | |
724 | might_sleep_if(pri & __GFP_WAIT); | |
725 | if (skb_cloned(skb)) { | |
726 | struct sk_buff *nskb = skb_copy(skb, pri); | |
727 | kfree_skb(skb); /* Free our shared copy */ | |
728 | skb = nskb; | |
729 | } | |
730 | return skb; | |
731 | } | |
732 | ||
733 | /** | |
734 | * skb_peek | |
735 | * @list_: list to peek at | |
736 | * | |
737 | * Peek an &sk_buff. Unlike most other operations you _MUST_ | |
738 | * be careful with this one. A peek leaves the buffer on the | |
739 | * list and someone else may run off with it. You must hold | |
740 | * the appropriate locks or have a private queue to do this. | |
741 | * | |
742 | * Returns %NULL for an empty list or a pointer to the head element. | |
743 | * The reference count is not incremented and the reference is therefore | |
744 | * volatile. Use with caution. | |
745 | */ | |
746 | static inline struct sk_buff *skb_peek(struct sk_buff_head *list_) | |
747 | { | |
748 | struct sk_buff *list = ((struct sk_buff *)list_)->next; | |
749 | if (list == (struct sk_buff *)list_) | |
750 | list = NULL; | |
751 | return list; | |
752 | } | |
753 | ||
754 | /** | |
755 | * skb_peek_tail | |
756 | * @list_: list to peek at | |
757 | * | |
758 | * Peek an &sk_buff. Unlike most other operations you _MUST_ | |
759 | * be careful with this one. A peek leaves the buffer on the | |
760 | * list and someone else may run off with it. You must hold | |
761 | * the appropriate locks or have a private queue to do this. | |
762 | * | |
763 | * Returns %NULL for an empty list or a pointer to the tail element. | |
764 | * The reference count is not incremented and the reference is therefore | |
765 | * volatile. Use with caution. | |
766 | */ | |
767 | static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_) | |
768 | { | |
769 | struct sk_buff *list = ((struct sk_buff *)list_)->prev; | |
770 | if (list == (struct sk_buff *)list_) | |
771 | list = NULL; | |
772 | return list; | |
773 | } | |
774 | ||
775 | /** | |
776 | * skb_queue_len - get queue length | |
777 | * @list_: list to measure | |
778 | * | |
779 | * Return the length of an &sk_buff queue. | |
780 | */ | |
781 | static inline __u32 skb_queue_len(const struct sk_buff_head *list_) | |
782 | { | |
783 | return list_->qlen; | |
784 | } | |
785 | ||
786 | /** | |
787 | * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head | |
788 | * @list: queue to initialize | |
789 | * | |
790 | * This initializes only the list and queue length aspects of | |
791 | * an sk_buff_head object. This allows to initialize the list | |
792 | * aspects of an sk_buff_head without reinitializing things like | |
793 | * the spinlock. It can also be used for on-stack sk_buff_head | |
794 | * objects where the spinlock is known to not be used. | |
795 | */ | |
796 | static inline void __skb_queue_head_init(struct sk_buff_head *list) | |
797 | { | |
798 | list->prev = list->next = (struct sk_buff *)list; | |
799 | list->qlen = 0; | |
800 | } | |
801 | ||
802 | /* | |
803 | * This function creates a split out lock class for each invocation; | |
804 | * this is needed for now since a whole lot of users of the skb-queue | |
805 | * infrastructure in drivers have different locking usage (in hardirq) | |
806 | * than the networking core (in softirq only). In the long run either the | |
807 | * network layer or drivers should need annotation to consolidate the | |
808 | * main types of usage into 3 classes. | |
809 | */ | |
810 | static inline void skb_queue_head_init(struct sk_buff_head *list) | |
811 | { | |
812 | spin_lock_init(&list->lock); | |
813 | __skb_queue_head_init(list); | |
814 | } | |
815 | ||
816 | static inline void skb_queue_head_init_class(struct sk_buff_head *list, | |
817 | struct lock_class_key *class) | |
818 | { | |
819 | skb_queue_head_init(list); | |
820 | lockdep_set_class(&list->lock, class); | |
821 | } | |
822 | ||
823 | /* | |
824 | * Insert an sk_buff on a list. | |
825 | * | |
826 | * The "__skb_xxxx()" functions are the non-atomic ones that | |
827 | * can only be called with interrupts disabled. | |
828 | */ | |
829 | extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list); | |
830 | static inline void __skb_insert(struct sk_buff *newsk, | |
831 | struct sk_buff *prev, struct sk_buff *next, | |
832 | struct sk_buff_head *list) | |
833 | { | |
834 | newsk->next = next; | |
835 | newsk->prev = prev; | |
836 | next->prev = prev->next = newsk; | |
837 | list->qlen++; | |
838 | } | |
839 | ||
840 | static inline void __skb_queue_splice(const struct sk_buff_head *list, | |
841 | struct sk_buff *prev, | |
842 | struct sk_buff *next) | |
843 | { | |
844 | struct sk_buff *first = list->next; | |
845 | struct sk_buff *last = list->prev; | |
846 | ||
847 | first->prev = prev; | |
848 | prev->next = first; | |
849 | ||
850 | last->next = next; | |
851 | next->prev = last; | |
852 | } | |
853 | ||
854 | /** | |
855 | * skb_queue_splice - join two skb lists, this is designed for stacks | |
856 | * @list: the new list to add | |
857 | * @head: the place to add it in the first list | |
858 | */ | |
859 | static inline void skb_queue_splice(const struct sk_buff_head *list, | |
860 | struct sk_buff_head *head) | |
861 | { | |
862 | if (!skb_queue_empty(list)) { | |
863 | __skb_queue_splice(list, (struct sk_buff *) head, head->next); | |
864 | head->qlen += list->qlen; | |
865 | } | |
866 | } | |
867 | ||
868 | /** | |
869 | * skb_queue_splice - join two skb lists and reinitialise the emptied list | |
870 | * @list: the new list to add | |
871 | * @head: the place to add it in the first list | |
872 | * | |
873 | * The list at @list is reinitialised | |
874 | */ | |
875 | static inline void skb_queue_splice_init(struct sk_buff_head *list, | |
876 | struct sk_buff_head *head) | |
877 | { | |
878 | if (!skb_queue_empty(list)) { | |
879 | __skb_queue_splice(list, (struct sk_buff *) head, head->next); | |
880 | head->qlen += list->qlen; | |
881 | __skb_queue_head_init(list); | |
882 | } | |
883 | } | |
884 | ||
885 | /** | |
886 | * skb_queue_splice_tail - join two skb lists, each list being a queue | |
887 | * @list: the new list to add | |
888 | * @head: the place to add it in the first list | |
889 | */ | |
890 | static inline void skb_queue_splice_tail(const struct sk_buff_head *list, | |
891 | struct sk_buff_head *head) | |
892 | { | |
893 | if (!skb_queue_empty(list)) { | |
894 | __skb_queue_splice(list, head->prev, (struct sk_buff *) head); | |
895 | head->qlen += list->qlen; | |
896 | } | |
897 | } | |
898 | ||
899 | /** | |
900 | * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list | |
901 | * @list: the new list to add | |
902 | * @head: the place to add it in the first list | |
903 | * | |
904 | * Each of the lists is a queue. | |
905 | * The list at @list is reinitialised | |
906 | */ | |
907 | static inline void skb_queue_splice_tail_init(struct sk_buff_head *list, | |
908 | struct sk_buff_head *head) | |
909 | { | |
910 | if (!skb_queue_empty(list)) { | |
911 | __skb_queue_splice(list, head->prev, (struct sk_buff *) head); | |
912 | head->qlen += list->qlen; | |
913 | __skb_queue_head_init(list); | |
914 | } | |
915 | } | |
916 | ||
917 | /** | |
918 | * __skb_queue_after - queue a buffer at the list head | |
919 | * @list: list to use | |
920 | * @prev: place after this buffer | |
921 | * @newsk: buffer to queue | |
922 | * | |
923 | * Queue a buffer int the middle of a list. This function takes no locks | |
924 | * and you must therefore hold required locks before calling it. | |
925 | * | |
926 | * A buffer cannot be placed on two lists at the same time. | |
927 | */ | |
928 | static inline void __skb_queue_after(struct sk_buff_head *list, | |
929 | struct sk_buff *prev, | |
930 | struct sk_buff *newsk) | |
931 | { | |
932 | __skb_insert(newsk, prev, prev->next, list); | |
933 | } | |
934 | ||
935 | extern void skb_append(struct sk_buff *old, struct sk_buff *newsk, | |
936 | struct sk_buff_head *list); | |
937 | ||
938 | static inline void __skb_queue_before(struct sk_buff_head *list, | |
939 | struct sk_buff *next, | |
940 | struct sk_buff *newsk) | |
941 | { | |
942 | __skb_insert(newsk, next->prev, next, list); | |
943 | } | |
944 | ||
945 | /** | |
946 | * __skb_queue_head - queue a buffer at the list head | |
947 | * @list: list to use | |
948 | * @newsk: buffer to queue | |
949 | * | |
950 | * Queue a buffer at the start of a list. This function takes no locks | |
951 | * and you must therefore hold required locks before calling it. | |
952 | * | |
953 | * A buffer cannot be placed on two lists at the same time. | |
954 | */ | |
955 | extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); | |
956 | static inline void __skb_queue_head(struct sk_buff_head *list, | |
957 | struct sk_buff *newsk) | |
958 | { | |
959 | __skb_queue_after(list, (struct sk_buff *)list, newsk); | |
960 | } | |
961 | ||
962 | /** | |
963 | * __skb_queue_tail - queue a buffer at the list tail | |
964 | * @list: list to use | |
965 | * @newsk: buffer to queue | |
966 | * | |
967 | * Queue a buffer at the end of a list. This function takes no locks | |
968 | * and you must therefore hold required locks before calling it. | |
969 | * | |
970 | * A buffer cannot be placed on two lists at the same time. | |
971 | */ | |
972 | extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk); | |
973 | static inline void __skb_queue_tail(struct sk_buff_head *list, | |
974 | struct sk_buff *newsk) | |
975 | { | |
976 | __skb_queue_before(list, (struct sk_buff *)list, newsk); | |
977 | } | |
978 | ||
979 | /* | |
980 | * remove sk_buff from list. _Must_ be called atomically, and with | |
981 | * the list known.. | |
982 | */ | |
983 | extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list); | |
984 | static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) | |
985 | { | |
986 | struct sk_buff *next, *prev; | |
987 | ||
988 | list->qlen--; | |
989 | next = skb->next; | |
990 | prev = skb->prev; | |
991 | skb->next = skb->prev = NULL; | |
992 | next->prev = prev; | |
993 | prev->next = next; | |
994 | } | |
995 | ||
996 | /** | |
997 | * __skb_dequeue - remove from the head of the queue | |
998 | * @list: list to dequeue from | |
999 | * | |
1000 | * Remove the head of the list. This function does not take any locks | |
1001 | * so must be used with appropriate locks held only. The head item is | |
1002 | * returned or %NULL if the list is empty. | |
1003 | */ | |
1004 | extern struct sk_buff *skb_dequeue(struct sk_buff_head *list); | |
1005 | static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list) | |
1006 | { | |
1007 | struct sk_buff *skb = skb_peek(list); | |
1008 | if (skb) | |
1009 | __skb_unlink(skb, list); | |
1010 | return skb; | |
1011 | } | |
1012 | ||
1013 | /** | |
1014 | * __skb_dequeue_tail - remove from the tail of the queue | |
1015 | * @list: list to dequeue from | |
1016 | * | |
1017 | * Remove the tail of the list. This function does not take any locks | |
1018 | * so must be used with appropriate locks held only. The tail item is | |
1019 | * returned or %NULL if the list is empty. | |
1020 | */ | |
1021 | extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list); | |
1022 | static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list) | |
1023 | { | |
1024 | struct sk_buff *skb = skb_peek_tail(list); | |
1025 | if (skb) | |
1026 | __skb_unlink(skb, list); | |
1027 | return skb; | |
1028 | } | |
1029 | ||
1030 | ||
1031 | static inline int skb_is_nonlinear(const struct sk_buff *skb) | |
1032 | { | |
1033 | return skb->data_len; | |
1034 | } | |
1035 | ||
1036 | static inline unsigned int skb_headlen(const struct sk_buff *skb) | |
1037 | { | |
1038 | return skb->len - skb->data_len; | |
1039 | } | |
1040 | ||
1041 | static inline int skb_pagelen(const struct sk_buff *skb) | |
1042 | { | |
1043 | int i, len = 0; | |
1044 | ||
1045 | for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) | |
1046 | len += skb_shinfo(skb)->frags[i].size; | |
1047 | return len + skb_headlen(skb); | |
1048 | } | |
1049 | ||
1050 | static inline void skb_fill_page_desc(struct sk_buff *skb, int i, | |
1051 | struct page *page, int off, int size) | |
1052 | { | |
1053 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
1054 | ||
1055 | frag->page = page; | |
1056 | frag->page_offset = off; | |
1057 | frag->size = size; | |
1058 | skb_shinfo(skb)->nr_frags = i + 1; | |
1059 | } | |
1060 | ||
1061 | extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, | |
1062 | int off, int size); | |
1063 | ||
1064 | #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags) | |
1065 | #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_shinfo(skb)->frag_list) | |
1066 | #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) | |
1067 | ||
1068 | #ifdef NET_SKBUFF_DATA_USES_OFFSET | |
1069 | static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) | |
1070 | { | |
1071 | return skb->head + skb->tail; | |
1072 | } | |
1073 | ||
1074 | static inline void skb_reset_tail_pointer(struct sk_buff *skb) | |
1075 | { | |
1076 | skb->tail = skb->data - skb->head; | |
1077 | } | |
1078 | ||
1079 | static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) | |
1080 | { | |
1081 | skb_reset_tail_pointer(skb); | |
1082 | skb->tail += offset; | |
1083 | } | |
1084 | #else /* NET_SKBUFF_DATA_USES_OFFSET */ | |
1085 | static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) | |
1086 | { | |
1087 | return skb->tail; | |
1088 | } | |
1089 | ||
1090 | static inline void skb_reset_tail_pointer(struct sk_buff *skb) | |
1091 | { | |
1092 | skb->tail = skb->data; | |
1093 | } | |
1094 | ||
1095 | static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) | |
1096 | { | |
1097 | skb->tail = skb->data + offset; | |
1098 | } | |
1099 | ||
1100 | #endif /* NET_SKBUFF_DATA_USES_OFFSET */ | |
1101 | ||
1102 | /* | |
1103 | * Add data to an sk_buff | |
1104 | */ | |
1105 | extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len); | |
1106 | static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len) | |
1107 | { | |
1108 | unsigned char *tmp = skb_tail_pointer(skb); | |
1109 | SKB_LINEAR_ASSERT(skb); | |
1110 | skb->tail += len; | |
1111 | skb->len += len; | |
1112 | return tmp; | |
1113 | } | |
1114 | ||
1115 | extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len); | |
1116 | static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len) | |
1117 | { | |
1118 | skb->data -= len; | |
1119 | skb->len += len; | |
1120 | return skb->data; | |
1121 | } | |
1122 | ||
1123 | extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len); | |
1124 | static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len) | |
1125 | { | |
1126 | skb->len -= len; | |
1127 | BUG_ON(skb->len < skb->data_len); | |
1128 | return skb->data += len; | |
1129 | } | |
1130 | ||
1131 | extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta); | |
1132 | ||
1133 | static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len) | |
1134 | { | |
1135 | if (len > skb_headlen(skb) && | |
1136 | !__pskb_pull_tail(skb, len - skb_headlen(skb))) | |
1137 | return NULL; | |
1138 | skb->len -= len; | |
1139 | return skb->data += len; | |
1140 | } | |
1141 | ||
1142 | static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len) | |
1143 | { | |
1144 | return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len); | |
1145 | } | |
1146 | ||
1147 | static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len) | |
1148 | { | |
1149 | if (likely(len <= skb_headlen(skb))) | |
1150 | return 1; | |
1151 | if (unlikely(len > skb->len)) | |
1152 | return 0; | |
1153 | return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL; | |
1154 | } | |
1155 | ||
1156 | /** | |
1157 | * skb_headroom - bytes at buffer head | |
1158 | * @skb: buffer to check | |
1159 | * | |
1160 | * Return the number of bytes of free space at the head of an &sk_buff. | |
1161 | */ | |
1162 | static inline unsigned int skb_headroom(const struct sk_buff *skb) | |
1163 | { | |
1164 | return skb->data - skb->head; | |
1165 | } | |
1166 | ||
1167 | /** | |
1168 | * skb_tailroom - bytes at buffer end | |
1169 | * @skb: buffer to check | |
1170 | * | |
1171 | * Return the number of bytes of free space at the tail of an sk_buff | |
1172 | */ | |
1173 | static inline int skb_tailroom(const struct sk_buff *skb) | |
1174 | { | |
1175 | return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail; | |
1176 | } | |
1177 | ||
1178 | /** | |
1179 | * skb_reserve - adjust headroom | |
1180 | * @skb: buffer to alter | |
1181 | * @len: bytes to move | |
1182 | * | |
1183 | * Increase the headroom of an empty &sk_buff by reducing the tail | |
1184 | * room. This is only allowed for an empty buffer. | |
1185 | */ | |
1186 | static inline void skb_reserve(struct sk_buff *skb, int len) | |
1187 | { | |
1188 | skb->data += len; | |
1189 | skb->tail += len; | |
1190 | } | |
1191 | ||
1192 | #ifdef NET_SKBUFF_DATA_USES_OFFSET | |
1193 | static inline unsigned char *skb_transport_header(const struct sk_buff *skb) | |
1194 | { | |
1195 | return skb->head + skb->transport_header; | |
1196 | } | |
1197 | ||
1198 | static inline void skb_reset_transport_header(struct sk_buff *skb) | |
1199 | { | |
1200 | skb->transport_header = skb->data - skb->head; | |
1201 | } | |
1202 | ||
1203 | static inline void skb_set_transport_header(struct sk_buff *skb, | |
1204 | const int offset) | |
1205 | { | |
1206 | skb_reset_transport_header(skb); | |
1207 | skb->transport_header += offset; | |
1208 | } | |
1209 | ||
1210 | static inline unsigned char *skb_network_header(const struct sk_buff *skb) | |
1211 | { | |
1212 | return skb->head + skb->network_header; | |
1213 | } | |
1214 | ||
1215 | static inline void skb_reset_network_header(struct sk_buff *skb) | |
1216 | { | |
1217 | skb->network_header = skb->data - skb->head; | |
1218 | } | |
1219 | ||
1220 | static inline void skb_set_network_header(struct sk_buff *skb, const int offset) | |
1221 | { | |
1222 | skb_reset_network_header(skb); | |
1223 | skb->network_header += offset; | |
1224 | } | |
1225 | ||
1226 | static inline unsigned char *skb_mac_header(const struct sk_buff *skb) | |
1227 | { | |
1228 | return skb->head + skb->mac_header; | |
1229 | } | |
1230 | ||
1231 | static inline int skb_mac_header_was_set(const struct sk_buff *skb) | |
1232 | { | |
1233 | return skb->mac_header != ~0U; | |
1234 | } | |
1235 | ||
1236 | static inline void skb_reset_mac_header(struct sk_buff *skb) | |
1237 | { | |
1238 | skb->mac_header = skb->data - skb->head; | |
1239 | } | |
1240 | ||
1241 | static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) | |
1242 | { | |
1243 | skb_reset_mac_header(skb); | |
1244 | skb->mac_header += offset; | |
1245 | } | |
1246 | ||
1247 | #else /* NET_SKBUFF_DATA_USES_OFFSET */ | |
1248 | ||
1249 | static inline unsigned char *skb_transport_header(const struct sk_buff *skb) | |
1250 | { | |
1251 | return skb->transport_header; | |
1252 | } | |
1253 | ||
1254 | static inline void skb_reset_transport_header(struct sk_buff *skb) | |
1255 | { | |
1256 | skb->transport_header = skb->data; | |
1257 | } | |
1258 | ||
1259 | static inline void skb_set_transport_header(struct sk_buff *skb, | |
1260 | const int offset) | |
1261 | { | |
1262 | skb->transport_header = skb->data + offset; | |
1263 | } | |
1264 | ||
1265 | static inline unsigned char *skb_network_header(const struct sk_buff *skb) | |
1266 | { | |
1267 | return skb->network_header; | |
1268 | } | |
1269 | ||
1270 | static inline void skb_reset_network_header(struct sk_buff *skb) | |
1271 | { | |
1272 | skb->network_header = skb->data; | |
1273 | } | |
1274 | ||
1275 | static inline void skb_set_network_header(struct sk_buff *skb, const int offset) | |
1276 | { | |
1277 | skb->network_header = skb->data + offset; | |
1278 | } | |
1279 | ||
1280 | static inline unsigned char *skb_mac_header(const struct sk_buff *skb) | |
1281 | { | |
1282 | return skb->mac_header; | |
1283 | } | |
1284 | ||
1285 | static inline int skb_mac_header_was_set(const struct sk_buff *skb) | |
1286 | { | |
1287 | return skb->mac_header != NULL; | |
1288 | } | |
1289 | ||
1290 | static inline void skb_reset_mac_header(struct sk_buff *skb) | |
1291 | { | |
1292 | skb->mac_header = skb->data; | |
1293 | } | |
1294 | ||
1295 | static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) | |
1296 | { | |
1297 | skb->mac_header = skb->data + offset; | |
1298 | } | |
1299 | #endif /* NET_SKBUFF_DATA_USES_OFFSET */ | |
1300 | ||
1301 | static inline int skb_transport_offset(const struct sk_buff *skb) | |
1302 | { | |
1303 | return skb_transport_header(skb) - skb->data; | |
1304 | } | |
1305 | ||
1306 | static inline u32 skb_network_header_len(const struct sk_buff *skb) | |
1307 | { | |
1308 | return skb->transport_header - skb->network_header; | |
1309 | } | |
1310 | ||
1311 | static inline int skb_network_offset(const struct sk_buff *skb) | |
1312 | { | |
1313 | return skb_network_header(skb) - skb->data; | |
1314 | } | |
1315 | ||
1316 | /* | |
1317 | * CPUs often take a performance hit when accessing unaligned memory | |
1318 | * locations. The actual performance hit varies, it can be small if the | |
1319 | * hardware handles it or large if we have to take an exception and fix it | |
1320 | * in software. | |
1321 | * | |
1322 | * Since an ethernet header is 14 bytes network drivers often end up with | |
1323 | * the IP header at an unaligned offset. The IP header can be aligned by | |
1324 | * shifting the start of the packet by 2 bytes. Drivers should do this | |
1325 | * with: | |
1326 | * | |
1327 | * skb_reserve(NET_IP_ALIGN); | |
1328 | * | |
1329 | * The downside to this alignment of the IP header is that the DMA is now | |
1330 | * unaligned. On some architectures the cost of an unaligned DMA is high | |
1331 | * and this cost outweighs the gains made by aligning the IP header. | |
1332 | * | |
1333 | * Since this trade off varies between architectures, we allow NET_IP_ALIGN | |
1334 | * to be overridden. | |
1335 | */ | |
1336 | #ifndef NET_IP_ALIGN | |
1337 | #define NET_IP_ALIGN 2 | |
1338 | #endif | |
1339 | ||
1340 | /* | |
1341 | * The networking layer reserves some headroom in skb data (via | |
1342 | * dev_alloc_skb). This is used to avoid having to reallocate skb data when | |
1343 | * the header has to grow. In the default case, if the header has to grow | |
1344 | * 32 bytes or less we avoid the reallocation. | |
1345 | * | |
1346 | * Unfortunately this headroom changes the DMA alignment of the resulting | |
1347 | * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive | |
1348 | * on some architectures. An architecture can override this value, | |
1349 | * perhaps setting it to a cacheline in size (since that will maintain | |
1350 | * cacheline alignment of the DMA). It must be a power of 2. | |
1351 | * | |
1352 | * Various parts of the networking layer expect at least 32 bytes of | |
1353 | * headroom, you should not reduce this. | |
1354 | */ | |
1355 | #ifndef NET_SKB_PAD | |
1356 | #define NET_SKB_PAD 32 | |
1357 | #endif | |
1358 | ||
1359 | extern int ___pskb_trim(struct sk_buff *skb, unsigned int len); | |
1360 | ||
1361 | static inline void __skb_trim(struct sk_buff *skb, unsigned int len) | |
1362 | { | |
1363 | if (unlikely(skb->data_len)) { | |
1364 | WARN_ON(1); | |
1365 | return; | |
1366 | } | |
1367 | skb->len = len; | |
1368 | skb_set_tail_pointer(skb, len); | |
1369 | } | |
1370 | ||
1371 | extern void skb_trim(struct sk_buff *skb, unsigned int len); | |
1372 | ||
1373 | static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) | |
1374 | { | |
1375 | if (skb->data_len) | |
1376 | return ___pskb_trim(skb, len); | |
1377 | __skb_trim(skb, len); | |
1378 | return 0; | |
1379 | } | |
1380 | ||
1381 | static inline int pskb_trim(struct sk_buff *skb, unsigned int len) | |
1382 | { | |
1383 | return (len < skb->len) ? __pskb_trim(skb, len) : 0; | |
1384 | } | |
1385 | ||
1386 | /** | |
1387 | * pskb_trim_unique - remove end from a paged unique (not cloned) buffer | |
1388 | * @skb: buffer to alter | |
1389 | * @len: new length | |
1390 | * | |
1391 | * This is identical to pskb_trim except that the caller knows that | |
1392 | * the skb is not cloned so we should never get an error due to out- | |
1393 | * of-memory. | |
1394 | */ | |
1395 | static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len) | |
1396 | { | |
1397 | int err = pskb_trim(skb, len); | |
1398 | BUG_ON(err); | |
1399 | } | |
1400 | ||
1401 | /** | |
1402 | * skb_orphan - orphan a buffer | |
1403 | * @skb: buffer to orphan | |
1404 | * | |
1405 | * If a buffer currently has an owner then we call the owner's | |
1406 | * destructor function and make the @skb unowned. The buffer continues | |
1407 | * to exist but is no longer charged to its former owner. | |
1408 | */ | |
1409 | static inline void skb_orphan(struct sk_buff *skb) | |
1410 | { | |
1411 | if (skb->destructor) | |
1412 | skb->destructor(skb); | |
1413 | skb->destructor = NULL; | |
1414 | skb->sk = NULL; | |
1415 | } | |
1416 | ||
1417 | /** | |
1418 | * __skb_queue_purge - empty a list | |
1419 | * @list: list to empty | |
1420 | * | |
1421 | * Delete all buffers on an &sk_buff list. Each buffer is removed from | |
1422 | * the list and one reference dropped. This function does not take the | |
1423 | * list lock and the caller must hold the relevant locks to use it. | |
1424 | */ | |
1425 | extern void skb_queue_purge(struct sk_buff_head *list); | |
1426 | static inline void __skb_queue_purge(struct sk_buff_head *list) | |
1427 | { | |
1428 | struct sk_buff *skb; | |
1429 | while ((skb = __skb_dequeue(list)) != NULL) | |
1430 | kfree_skb(skb); | |
1431 | } | |
1432 | ||
1433 | /** | |
1434 | * __dev_alloc_skb - allocate an skbuff for receiving | |
1435 | * @length: length to allocate | |
1436 | * @gfp_mask: get_free_pages mask, passed to alloc_skb | |
1437 | * | |
1438 | * Allocate a new &sk_buff and assign it a usage count of one. The | |
1439 | * buffer has unspecified headroom built in. Users should allocate | |
1440 | * the headroom they think they need without accounting for the | |
1441 | * built in space. The built in space is used for optimisations. | |
1442 | * | |
1443 | * %NULL is returned if there is no free memory. | |
1444 | */ | |
1445 | static inline struct sk_buff *__dev_alloc_skb(unsigned int length, | |
1446 | gfp_t gfp_mask) | |
1447 | { | |
1448 | struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask); | |
1449 | if (likely(skb)) | |
1450 | skb_reserve(skb, NET_SKB_PAD); | |
1451 | return skb; | |
1452 | } | |
1453 | ||
1454 | extern struct sk_buff *dev_alloc_skb(unsigned int length); | |
1455 | ||
1456 | extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev, | |
1457 | unsigned int length, gfp_t gfp_mask); | |
1458 | ||
1459 | /** | |
1460 | * netdev_alloc_skb - allocate an skbuff for rx on a specific device | |
1461 | * @dev: network device to receive on | |
1462 | * @length: length to allocate | |
1463 | * | |
1464 | * Allocate a new &sk_buff and assign it a usage count of one. The | |
1465 | * buffer has unspecified headroom built in. Users should allocate | |
1466 | * the headroom they think they need without accounting for the | |
1467 | * built in space. The built in space is used for optimisations. | |
1468 | * | |
1469 | * %NULL is returned if there is no free memory. Although this function | |
1470 | * allocates memory it can be called from an interrupt. | |
1471 | */ | |
1472 | static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev, | |
1473 | unsigned int length) | |
1474 | { | |
1475 | return __netdev_alloc_skb(dev, length, GFP_ATOMIC); | |
1476 | } | |
1477 | ||
1478 | extern struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask); | |
1479 | ||
1480 | /** | |
1481 | * netdev_alloc_page - allocate a page for ps-rx on a specific device | |
1482 | * @dev: network device to receive on | |
1483 | * | |
1484 | * Allocate a new page node local to the specified device. | |
1485 | * | |
1486 | * %NULL is returned if there is no free memory. | |
1487 | */ | |
1488 | static inline struct page *netdev_alloc_page(struct net_device *dev) | |
1489 | { | |
1490 | return __netdev_alloc_page(dev, GFP_ATOMIC); | |
1491 | } | |
1492 | ||
1493 | static inline void netdev_free_page(struct net_device *dev, struct page *page) | |
1494 | { | |
1495 | __free_page(page); | |
1496 | } | |
1497 | ||
1498 | /** | |
1499 | * skb_clone_writable - is the header of a clone writable | |
1500 | * @skb: buffer to check | |
1501 | * @len: length up to which to write | |
1502 | * | |
1503 | * Returns true if modifying the header part of the cloned buffer | |
1504 | * does not requires the data to be copied. | |
1505 | */ | |
1506 | static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len) | |
1507 | { | |
1508 | return !skb_header_cloned(skb) && | |
1509 | skb_headroom(skb) + len <= skb->hdr_len; | |
1510 | } | |
1511 | ||
1512 | static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom, | |
1513 | int cloned) | |
1514 | { | |
1515 | int delta = 0; | |
1516 | ||
1517 | if (headroom < NET_SKB_PAD) | |
1518 | headroom = NET_SKB_PAD; | |
1519 | if (headroom > skb_headroom(skb)) | |
1520 | delta = headroom - skb_headroom(skb); | |
1521 | ||
1522 | if (delta || cloned) | |
1523 | return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0, | |
1524 | GFP_ATOMIC); | |
1525 | return 0; | |
1526 | } | |
1527 | ||
1528 | /** | |
1529 | * skb_cow - copy header of skb when it is required | |
1530 | * @skb: buffer to cow | |
1531 | * @headroom: needed headroom | |
1532 | * | |
1533 | * If the skb passed lacks sufficient headroom or its data part | |
1534 | * is shared, data is reallocated. If reallocation fails, an error | |
1535 | * is returned and original skb is not changed. | |
1536 | * | |
1537 | * The result is skb with writable area skb->head...skb->tail | |
1538 | * and at least @headroom of space at head. | |
1539 | */ | |
1540 | static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) | |
1541 | { | |
1542 | return __skb_cow(skb, headroom, skb_cloned(skb)); | |
1543 | } | |
1544 | ||
1545 | /** | |
1546 | * skb_cow_head - skb_cow but only making the head writable | |
1547 | * @skb: buffer to cow | |
1548 | * @headroom: needed headroom | |
1549 | * | |
1550 | * This function is identical to skb_cow except that we replace the | |
1551 | * skb_cloned check by skb_header_cloned. It should be used when | |
1552 | * you only need to push on some header and do not need to modify | |
1553 | * the data. | |
1554 | */ | |
1555 | static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom) | |
1556 | { | |
1557 | return __skb_cow(skb, headroom, skb_header_cloned(skb)); | |
1558 | } | |
1559 | ||
1560 | /** | |
1561 | * skb_padto - pad an skbuff up to a minimal size | |
1562 | * @skb: buffer to pad | |
1563 | * @len: minimal length | |
1564 | * | |
1565 | * Pads up a buffer to ensure the trailing bytes exist and are | |
1566 | * blanked. If the buffer already contains sufficient data it | |
1567 | * is untouched. Otherwise it is extended. Returns zero on | |
1568 | * success. The skb is freed on error. | |
1569 | */ | |
1570 | ||
1571 | static inline int skb_padto(struct sk_buff *skb, unsigned int len) | |
1572 | { | |
1573 | unsigned int size = skb->len; | |
1574 | if (likely(size >= len)) | |
1575 | return 0; | |
1576 | return skb_pad(skb, len - size); | |
1577 | } | |
1578 | ||
1579 | static inline int skb_add_data(struct sk_buff *skb, | |
1580 | char __user *from, int copy) | |
1581 | { | |
1582 | const int off = skb->len; | |
1583 | ||
1584 | if (skb->ip_summed == CHECKSUM_NONE) { | |
1585 | int err = 0; | |
1586 | __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy), | |
1587 | copy, 0, &err); | |
1588 | if (!err) { | |
1589 | skb->csum = csum_block_add(skb->csum, csum, off); | |
1590 | return 0; | |
1591 | } | |
1592 | } else if (!copy_from_user(skb_put(skb, copy), from, copy)) | |
1593 | return 0; | |
1594 | ||
1595 | __skb_trim(skb, off); | |
1596 | return -EFAULT; | |
1597 | } | |
1598 | ||
1599 | static inline int skb_can_coalesce(struct sk_buff *skb, int i, | |
1600 | struct page *page, int off) | |
1601 | { | |
1602 | if (i) { | |
1603 | struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1]; | |
1604 | ||
1605 | return page == frag->page && | |
1606 | off == frag->page_offset + frag->size; | |
1607 | } | |
1608 | return 0; | |
1609 | } | |
1610 | ||
1611 | static inline int __skb_linearize(struct sk_buff *skb) | |
1612 | { | |
1613 | return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM; | |
1614 | } | |
1615 | ||
1616 | /** | |
1617 | * skb_linearize - convert paged skb to linear one | |
1618 | * @skb: buffer to linarize | |
1619 | * | |
1620 | * If there is no free memory -ENOMEM is returned, otherwise zero | |
1621 | * is returned and the old skb data released. | |
1622 | */ | |
1623 | static inline int skb_linearize(struct sk_buff *skb) | |
1624 | { | |
1625 | return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0; | |
1626 | } | |
1627 | ||
1628 | /** | |
1629 | * skb_linearize_cow - make sure skb is linear and writable | |
1630 | * @skb: buffer to process | |
1631 | * | |
1632 | * If there is no free memory -ENOMEM is returned, otherwise zero | |
1633 | * is returned and the old skb data released. | |
1634 | */ | |
1635 | static inline int skb_linearize_cow(struct sk_buff *skb) | |
1636 | { | |
1637 | return skb_is_nonlinear(skb) || skb_cloned(skb) ? | |
1638 | __skb_linearize(skb) : 0; | |
1639 | } | |
1640 | ||
1641 | /** | |
1642 | * skb_postpull_rcsum - update checksum for received skb after pull | |
1643 | * @skb: buffer to update | |
1644 | * @start: start of data before pull | |
1645 | * @len: length of data pulled | |
1646 | * | |
1647 | * After doing a pull on a received packet, you need to call this to | |
1648 | * update the CHECKSUM_COMPLETE checksum, or set ip_summed to | |
1649 | * CHECKSUM_NONE so that it can be recomputed from scratch. | |
1650 | */ | |
1651 | ||
1652 | static inline void skb_postpull_rcsum(struct sk_buff *skb, | |
1653 | const void *start, unsigned int len) | |
1654 | { | |
1655 | if (skb->ip_summed == CHECKSUM_COMPLETE) | |
1656 | skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0)); | |
1657 | } | |
1658 | ||
1659 | unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); | |
1660 | ||
1661 | /** | |
1662 | * pskb_trim_rcsum - trim received skb and update checksum | |
1663 | * @skb: buffer to trim | |
1664 | * @len: new length | |
1665 | * | |
1666 | * This is exactly the same as pskb_trim except that it ensures the | |
1667 | * checksum of received packets are still valid after the operation. | |
1668 | */ | |
1669 | ||
1670 | static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len) | |
1671 | { | |
1672 | if (likely(len >= skb->len)) | |
1673 | return 0; | |
1674 | if (skb->ip_summed == CHECKSUM_COMPLETE) | |
1675 | skb->ip_summed = CHECKSUM_NONE; | |
1676 | return __pskb_trim(skb, len); | |
1677 | } | |
1678 | ||
1679 | #define skb_queue_walk(queue, skb) \ | |
1680 | for (skb = (queue)->next; \ | |
1681 | prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \ | |
1682 | skb = skb->next) | |
1683 | ||
1684 | #define skb_queue_walk_safe(queue, skb, tmp) \ | |
1685 | for (skb = (queue)->next, tmp = skb->next; \ | |
1686 | skb != (struct sk_buff *)(queue); \ | |
1687 | skb = tmp, tmp = skb->next) | |
1688 | ||
1689 | #define skb_queue_walk_from(queue, skb) \ | |
1690 | for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \ | |
1691 | skb = skb->next) | |
1692 | ||
1693 | #define skb_queue_walk_from_safe(queue, skb, tmp) \ | |
1694 | for (tmp = skb->next; \ | |
1695 | skb != (struct sk_buff *)(queue); \ | |
1696 | skb = tmp, tmp = skb->next) | |
1697 | ||
1698 | #define skb_queue_reverse_walk(queue, skb) \ | |
1699 | for (skb = (queue)->prev; \ | |
1700 | prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \ | |
1701 | skb = skb->prev) | |
1702 | ||
1703 | ||
1704 | extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, | |
1705 | int *peeked, int *err); | |
1706 | extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, | |
1707 | int noblock, int *err); | |
1708 | extern unsigned int datagram_poll(struct file *file, struct socket *sock, | |
1709 | struct poll_table_struct *wait); | |
1710 | extern int skb_copy_datagram_iovec(const struct sk_buff *from, | |
1711 | int offset, struct iovec *to, | |
1712 | int size); | |
1713 | extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, | |
1714 | int hlen, | |
1715 | struct iovec *iov); | |
1716 | extern int skb_copy_datagram_from_iovec(struct sk_buff *skb, | |
1717 | int offset, | |
1718 | const struct iovec *from, | |
1719 | int from_offset, | |
1720 | int len); | |
1721 | extern int skb_copy_datagram_const_iovec(const struct sk_buff *from, | |
1722 | int offset, | |
1723 | const struct iovec *to, | |
1724 | int to_offset, | |
1725 | int size); | |
1726 | extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb); | |
1727 | extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, | |
1728 | unsigned int flags); | |
1729 | extern __wsum skb_checksum(const struct sk_buff *skb, int offset, | |
1730 | int len, __wsum csum); | |
1731 | extern int skb_copy_bits(const struct sk_buff *skb, int offset, | |
1732 | void *to, int len); | |
1733 | extern int skb_store_bits(struct sk_buff *skb, int offset, | |
1734 | const void *from, int len); | |
1735 | extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, | |
1736 | int offset, u8 *to, int len, | |
1737 | __wsum csum); | |
1738 | extern int skb_splice_bits(struct sk_buff *skb, | |
1739 | unsigned int offset, | |
1740 | struct pipe_inode_info *pipe, | |
1741 | unsigned int len, | |
1742 | unsigned int flags); | |
1743 | extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); | |
1744 | extern void skb_split(struct sk_buff *skb, | |
1745 | struct sk_buff *skb1, const u32 len); | |
1746 | extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, | |
1747 | int shiftlen); | |
1748 | ||
1749 | extern struct sk_buff *skb_segment(struct sk_buff *skb, int features); | |
1750 | ||
1751 | static inline void *skb_header_pointer(const struct sk_buff *skb, int offset, | |
1752 | int len, void *buffer) | |
1753 | { | |
1754 | int hlen = skb_headlen(skb); | |
1755 | ||
1756 | if (hlen - offset >= len) | |
1757 | return skb->data + offset; | |
1758 | ||
1759 | if (skb_copy_bits(skb, offset, buffer, len) < 0) | |
1760 | return NULL; | |
1761 | ||
1762 | return buffer; | |
1763 | } | |
1764 | ||
1765 | static inline void skb_copy_from_linear_data(const struct sk_buff *skb, | |
1766 | void *to, | |
1767 | const unsigned int len) | |
1768 | { | |
1769 | memcpy(to, skb->data, len); | |
1770 | } | |
1771 | ||
1772 | static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb, | |
1773 | const int offset, void *to, | |
1774 | const unsigned int len) | |
1775 | { | |
1776 | memcpy(to, skb->data + offset, len); | |
1777 | } | |
1778 | ||
1779 | static inline void skb_copy_to_linear_data(struct sk_buff *skb, | |
1780 | const void *from, | |
1781 | const unsigned int len) | |
1782 | { | |
1783 | memcpy(skb->data, from, len); | |
1784 | } | |
1785 | ||
1786 | static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb, | |
1787 | const int offset, | |
1788 | const void *from, | |
1789 | const unsigned int len) | |
1790 | { | |
1791 | memcpy(skb->data + offset, from, len); | |
1792 | } | |
1793 | ||
1794 | extern void skb_init(void); | |
1795 | ||
1796 | static inline ktime_t skb_get_ktime(const struct sk_buff *skb) | |
1797 | { | |
1798 | return skb->tstamp; | |
1799 | } | |
1800 | ||
1801 | /** | |
1802 | * skb_get_timestamp - get timestamp from a skb | |
1803 | * @skb: skb to get stamp from | |
1804 | * @stamp: pointer to struct timeval to store stamp in | |
1805 | * | |
1806 | * Timestamps are stored in the skb as offsets to a base timestamp. | |
1807 | * This function converts the offset back to a struct timeval and stores | |
1808 | * it in stamp. | |
1809 | */ | |
1810 | static inline void skb_get_timestamp(const struct sk_buff *skb, | |
1811 | struct timeval *stamp) | |
1812 | { | |
1813 | *stamp = ktime_to_timeval(skb->tstamp); | |
1814 | } | |
1815 | ||
1816 | static inline void skb_get_timestampns(const struct sk_buff *skb, | |
1817 | struct timespec *stamp) | |
1818 | { | |
1819 | *stamp = ktime_to_timespec(skb->tstamp); | |
1820 | } | |
1821 | ||
1822 | static inline void __net_timestamp(struct sk_buff *skb) | |
1823 | { | |
1824 | skb->tstamp = ktime_get_real(); | |
1825 | } | |
1826 | ||
1827 | static inline ktime_t net_timedelta(ktime_t t) | |
1828 | { | |
1829 | return ktime_sub(ktime_get_real(), t); | |
1830 | } | |
1831 | ||
1832 | static inline ktime_t net_invalid_timestamp(void) | |
1833 | { | |
1834 | return ktime_set(0, 0); | |
1835 | } | |
1836 | ||
1837 | /** | |
1838 | * skb_tstamp_tx - queue clone of skb with send time stamps | |
1839 | * @orig_skb: the original outgoing packet | |
1840 | * @hwtstamps: hardware time stamps, may be NULL if not available | |
1841 | * | |
1842 | * If the skb has a socket associated, then this function clones the | |
1843 | * skb (thus sharing the actual data and optional structures), stores | |
1844 | * the optional hardware time stamping information (if non NULL) or | |
1845 | * generates a software time stamp (otherwise), then queues the clone | |
1846 | * to the error queue of the socket. Errors are silently ignored. | |
1847 | */ | |
1848 | extern void skb_tstamp_tx(struct sk_buff *orig_skb, | |
1849 | struct skb_shared_hwtstamps *hwtstamps); | |
1850 | ||
1851 | extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); | |
1852 | extern __sum16 __skb_checksum_complete(struct sk_buff *skb); | |
1853 | ||
1854 | static inline int skb_csum_unnecessary(const struct sk_buff *skb) | |
1855 | { | |
1856 | return skb->ip_summed & CHECKSUM_UNNECESSARY; | |
1857 | } | |
1858 | ||
1859 | /** | |
1860 | * skb_checksum_complete - Calculate checksum of an entire packet | |
1861 | * @skb: packet to process | |
1862 | * | |
1863 | * This function calculates the checksum over the entire packet plus | |
1864 | * the value of skb->csum. The latter can be used to supply the | |
1865 | * checksum of a pseudo header as used by TCP/UDP. It returns the | |
1866 | * checksum. | |
1867 | * | |
1868 | * For protocols that contain complete checksums such as ICMP/TCP/UDP, | |
1869 | * this function can be used to verify that checksum on received | |
1870 | * packets. In that case the function should return zero if the | |
1871 | * checksum is correct. In particular, this function will return zero | |
1872 | * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the | |
1873 | * hardware has already verified the correctness of the checksum. | |
1874 | */ | |
1875 | static inline __sum16 skb_checksum_complete(struct sk_buff *skb) | |
1876 | { | |
1877 | return skb_csum_unnecessary(skb) ? | |
1878 | 0 : __skb_checksum_complete(skb); | |
1879 | } | |
1880 | ||
1881 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) | |
1882 | extern void nf_conntrack_destroy(struct nf_conntrack *nfct); | |
1883 | static inline void nf_conntrack_put(struct nf_conntrack *nfct) | |
1884 | { | |
1885 | if (nfct && atomic_dec_and_test(&nfct->use)) | |
1886 | nf_conntrack_destroy(nfct); | |
1887 | } | |
1888 | static inline void nf_conntrack_get(struct nf_conntrack *nfct) | |
1889 | { | |
1890 | if (nfct) | |
1891 | atomic_inc(&nfct->use); | |
1892 | } | |
1893 | static inline void nf_conntrack_get_reasm(struct sk_buff *skb) | |
1894 | { | |
1895 | if (skb) | |
1896 | atomic_inc(&skb->users); | |
1897 | } | |
1898 | static inline void nf_conntrack_put_reasm(struct sk_buff *skb) | |
1899 | { | |
1900 | if (skb) | |
1901 | kfree_skb(skb); | |
1902 | } | |
1903 | #endif | |
1904 | #ifdef CONFIG_BRIDGE_NETFILTER | |
1905 | static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge) | |
1906 | { | |
1907 | if (nf_bridge && atomic_dec_and_test(&nf_bridge->use)) | |
1908 | kfree(nf_bridge); | |
1909 | } | |
1910 | static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge) | |
1911 | { | |
1912 | if (nf_bridge) | |
1913 | atomic_inc(&nf_bridge->use); | |
1914 | } | |
1915 | #endif /* CONFIG_BRIDGE_NETFILTER */ | |
1916 | static inline void nf_reset(struct sk_buff *skb) | |
1917 | { | |
1918 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) | |
1919 | nf_conntrack_put(skb->nfct); | |
1920 | skb->nfct = NULL; | |
1921 | nf_conntrack_put_reasm(skb->nfct_reasm); | |
1922 | skb->nfct_reasm = NULL; | |
1923 | #endif | |
1924 | #ifdef CONFIG_BRIDGE_NETFILTER | |
1925 | nf_bridge_put(skb->nf_bridge); | |
1926 | skb->nf_bridge = NULL; | |
1927 | #endif | |
1928 | } | |
1929 | ||
1930 | /* Note: This doesn't put any conntrack and bridge info in dst. */ | |
1931 | static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src) | |
1932 | { | |
1933 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) | |
1934 | dst->nfct = src->nfct; | |
1935 | nf_conntrack_get(src->nfct); | |
1936 | dst->nfctinfo = src->nfctinfo; | |
1937 | dst->nfct_reasm = src->nfct_reasm; | |
1938 | nf_conntrack_get_reasm(src->nfct_reasm); | |
1939 | #endif | |
1940 | #ifdef CONFIG_BRIDGE_NETFILTER | |
1941 | dst->nf_bridge = src->nf_bridge; | |
1942 | nf_bridge_get(src->nf_bridge); | |
1943 | #endif | |
1944 | } | |
1945 | ||
1946 | static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src) | |
1947 | { | |
1948 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) | |
1949 | nf_conntrack_put(dst->nfct); | |
1950 | nf_conntrack_put_reasm(dst->nfct_reasm); | |
1951 | #endif | |
1952 | #ifdef CONFIG_BRIDGE_NETFILTER | |
1953 | nf_bridge_put(dst->nf_bridge); | |
1954 | #endif | |
1955 | __nf_copy(dst, src); | |
1956 | } | |
1957 | ||
1958 | #ifdef CONFIG_NETWORK_SECMARK | |
1959 | static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) | |
1960 | { | |
1961 | to->secmark = from->secmark; | |
1962 | } | |
1963 | ||
1964 | static inline void skb_init_secmark(struct sk_buff *skb) | |
1965 | { | |
1966 | skb->secmark = 0; | |
1967 | } | |
1968 | #else | |
1969 | static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) | |
1970 | { } | |
1971 | ||
1972 | static inline void skb_init_secmark(struct sk_buff *skb) | |
1973 | { } | |
1974 | #endif | |
1975 | ||
1976 | static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping) | |
1977 | { | |
1978 | skb->queue_mapping = queue_mapping; | |
1979 | } | |
1980 | ||
1981 | static inline u16 skb_get_queue_mapping(const struct sk_buff *skb) | |
1982 | { | |
1983 | return skb->queue_mapping; | |
1984 | } | |
1985 | ||
1986 | static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from) | |
1987 | { | |
1988 | to->queue_mapping = from->queue_mapping; | |
1989 | } | |
1990 | ||
1991 | static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue) | |
1992 | { | |
1993 | skb->queue_mapping = rx_queue + 1; | |
1994 | } | |
1995 | ||
1996 | static inline u16 skb_get_rx_queue(const struct sk_buff *skb) | |
1997 | { | |
1998 | return skb->queue_mapping - 1; | |
1999 | } | |
2000 | ||
2001 | static inline bool skb_rx_queue_recorded(const struct sk_buff *skb) | |
2002 | { | |
2003 | return (skb->queue_mapping != 0); | |
2004 | } | |
2005 | ||
2006 | extern u16 skb_tx_hash(const struct net_device *dev, | |
2007 | const struct sk_buff *skb); | |
2008 | ||
2009 | #ifdef CONFIG_XFRM | |
2010 | static inline struct sec_path *skb_sec_path(struct sk_buff *skb) | |
2011 | { | |
2012 | return skb->sp; | |
2013 | } | |
2014 | #else | |
2015 | static inline struct sec_path *skb_sec_path(struct sk_buff *skb) | |
2016 | { | |
2017 | return NULL; | |
2018 | } | |
2019 | #endif | |
2020 | ||
2021 | static inline int skb_is_gso(const struct sk_buff *skb) | |
2022 | { | |
2023 | return skb_shinfo(skb)->gso_size; | |
2024 | } | |
2025 | ||
2026 | static inline int skb_is_gso_v6(const struct sk_buff *skb) | |
2027 | { | |
2028 | return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6; | |
2029 | } | |
2030 | ||
2031 | extern void __skb_warn_lro_forwarding(const struct sk_buff *skb); | |
2032 | ||
2033 | static inline bool skb_warn_if_lro(const struct sk_buff *skb) | |
2034 | { | |
2035 | /* LRO sets gso_size but not gso_type, whereas if GSO is really | |
2036 | * wanted then gso_type will be set. */ | |
2037 | struct skb_shared_info *shinfo = skb_shinfo(skb); | |
2038 | if (shinfo->gso_size != 0 && unlikely(shinfo->gso_type == 0)) { | |
2039 | __skb_warn_lro_forwarding(skb); | |
2040 | return true; | |
2041 | } | |
2042 | return false; | |
2043 | } | |
2044 | ||
2045 | static inline void skb_forward_csum(struct sk_buff *skb) | |
2046 | { | |
2047 | /* Unfortunately we don't support this one. Any brave souls? */ | |
2048 | if (skb->ip_summed == CHECKSUM_COMPLETE) | |
2049 | skb->ip_summed = CHECKSUM_NONE; | |
2050 | } | |
2051 | ||
2052 | bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off); | |
2053 | #endif /* __KERNEL__ */ | |
2054 | #endif /* _LINUX_SKBUFF_H */ |