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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/kmemcheck.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/net.h> | |
27 | #include <linux/textsearch.h> | |
28 | #include <net/checksum.h> | |
29 | #include <linux/rcupdate.h> | |
30 | #include <linux/dmaengine.h> | |
31 | #include <linux/hrtimer.h> | |
32 | ||
33 | /* Don't change this without changing skb_csum_unnecessary! */ | |
34 | #define CHECKSUM_NONE 0 | |
35 | #define CHECKSUM_UNNECESSARY 1 | |
36 | #define CHECKSUM_COMPLETE 2 | |
37 | #define CHECKSUM_PARTIAL 3 | |
38 | ||
39 | #define SKB_DATA_ALIGN(X) (((X) + (SMP_CACHE_BYTES - 1)) & \ | |
40 | ~(SMP_CACHE_BYTES - 1)) | |
41 | #define SKB_WITH_OVERHEAD(X) \ | |
42 | ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) | |
43 | #define SKB_MAX_ORDER(X, ORDER) \ | |
44 | SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X)) | |
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 | * COMPLETE: 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 COMPLETE, | |
63 | * not UNNECESSARY. | |
64 | * | |
65 | * PARTIAL: identical to the case for output below. This may occur | |
66 | * on a packet received directly from another Linux OS, e.g., | |
67 | * a virtualised Linux kernel on the same host. The packet can | |
68 | * be treated in the same way as UNNECESSARY except that on | |
69 | * output (i.e., forwarding) the checksum must be filled in | |
70 | * by the OS or the hardware. | |
71 | * | |
72 | * B. Checksumming on output. | |
73 | * | |
74 | * NONE: skb is checksummed by protocol or csum is not required. | |
75 | * | |
76 | * PARTIAL: device is required to csum packet as seen by hard_start_xmit | |
77 | * from skb->csum_start to the end and to record the checksum | |
78 | * at skb->csum_start + skb->csum_offset. | |
79 | * | |
80 | * Device must show its capabilities in dev->features, set | |
81 | * at device setup time. | |
82 | * NETIF_F_HW_CSUM - it is clever device, it is able to checksum | |
83 | * everything. | |
84 | * NETIF_F_NO_CSUM - loopback or reliable single hop media. | |
85 | * NETIF_F_IP_CSUM - device is dumb. It is able to csum only | |
86 | * TCP/UDP over IPv4. Sigh. Vendors like this | |
87 | * way by an unknown reason. Though, see comment above | |
88 | * about CHECKSUM_UNNECESSARY. 8) | |
89 | * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead. | |
90 | * | |
91 | * Any questions? No questions, good. --ANK | |
92 | */ | |
93 | ||
94 | struct net_device; | |
95 | struct scatterlist; | |
96 | struct pipe_inode_info; | |
97 | ||
98 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) | |
99 | struct nf_conntrack { | |
100 | atomic_t use; | |
101 | }; | |
102 | #endif | |
103 | ||
104 | #ifdef CONFIG_BRIDGE_NETFILTER | |
105 | struct nf_bridge_info { | |
106 | atomic_t use; | |
107 | struct net_device *physindev; | |
108 | struct net_device *physoutdev; | |
109 | unsigned int mask; | |
110 | unsigned long data[32 / sizeof(unsigned long)]; | |
111 | }; | |
112 | #endif | |
113 | ||
114 | struct sk_buff_head { | |
115 | /* These two members must be first. */ | |
116 | struct sk_buff *next; | |
117 | struct sk_buff *prev; | |
118 | ||
119 | __u32 qlen; | |
120 | spinlock_t lock; | |
121 | }; | |
122 | ||
123 | struct sk_buff; | |
124 | ||
125 | /* To allow 64K frame to be packed as single skb without frag_list */ | |
126 | #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2) | |
127 | ||
128 | typedef struct skb_frag_struct skb_frag_t; | |
129 | ||
130 | struct skb_frag_struct { | |
131 | struct page *page; | |
132 | __u32 page_offset; | |
133 | __u32 size; | |
134 | }; | |
135 | ||
136 | #define HAVE_HW_TIME_STAMP | |
137 | ||
138 | /** | |
139 | * struct skb_shared_hwtstamps - hardware time stamps | |
140 | * @hwtstamp: hardware time stamp transformed into duration | |
141 | * since arbitrary point in time | |
142 | * @syststamp: hwtstamp transformed to system time base | |
143 | * | |
144 | * Software time stamps generated by ktime_get_real() are stored in | |
145 | * skb->tstamp. The relation between the different kinds of time | |
146 | * stamps is as follows: | |
147 | * | |
148 | * syststamp and tstamp can be compared against each other in | |
149 | * arbitrary combinations. The accuracy of a | |
150 | * syststamp/tstamp/"syststamp from other device" comparison is | |
151 | * limited by the accuracy of the transformation into system time | |
152 | * base. This depends on the device driver and its underlying | |
153 | * hardware. | |
154 | * | |
155 | * hwtstamps can only be compared against other hwtstamps from | |
156 | * the same device. | |
157 | * | |
158 | * This structure is attached to packets as part of the | |
159 | * &skb_shared_info. Use skb_hwtstamps() to get a pointer. | |
160 | */ | |
161 | struct skb_shared_hwtstamps { | |
162 | ktime_t hwtstamp; | |
163 | ktime_t syststamp; | |
164 | }; | |
165 | ||
166 | /* Definitions for tx_flags in struct skb_shared_info */ | |
167 | enum { | |
168 | /* generate hardware time stamp */ | |
169 | SKBTX_HW_TSTAMP = 1 << 0, | |
170 | ||
171 | /* generate software time stamp */ | |
172 | SKBTX_SW_TSTAMP = 1 << 1, | |
173 | ||
174 | /* device driver is going to provide hardware time stamp */ | |
175 | SKBTX_IN_PROGRESS = 1 << 2, | |
176 | ||
177 | /* ensure the originating sk reference is available on driver level */ | |
178 | SKBTX_DRV_NEEDS_SK_REF = 1 << 3, | |
179 | }; | |
180 | ||
181 | /* This data is invariant across clones and lives at | |
182 | * the end of the header data, ie. at skb->end. | |
183 | */ | |
184 | struct skb_shared_info { | |
185 | unsigned short nr_frags; | |
186 | unsigned short gso_size; | |
187 | /* Warning: this field is not always filled in (UFO)! */ | |
188 | unsigned short gso_segs; | |
189 | unsigned short gso_type; | |
190 | __be32 ip6_frag_id; | |
191 | __u8 tx_flags; | |
192 | struct sk_buff *frag_list; | |
193 | struct skb_shared_hwtstamps hwtstamps; | |
194 | ||
195 | /* | |
196 | * Warning : all fields before dataref are cleared in __alloc_skb() | |
197 | */ | |
198 | atomic_t dataref; | |
199 | ||
200 | /* Intermediate layers must ensure that destructor_arg | |
201 | * remains valid until skb destructor */ | |
202 | void * destructor_arg; | |
203 | /* must be last field, see pskb_expand_head() */ | |
204 | skb_frag_t frags[MAX_SKB_FRAGS]; | |
205 | }; | |
206 | ||
207 | /* We divide dataref into two halves. The higher 16 bits hold references | |
208 | * to the payload part of skb->data. The lower 16 bits hold references to | |
209 | * the entire skb->data. A clone of a headerless skb holds the length of | |
210 | * the header in skb->hdr_len. | |
211 | * | |
212 | * All users must obey the rule that the skb->data reference count must be | |
213 | * greater than or equal to the payload reference count. | |
214 | * | |
215 | * Holding a reference to the payload part means that the user does not | |
216 | * care about modifications to the header part of skb->data. | |
217 | */ | |
218 | #define SKB_DATAREF_SHIFT 16 | |
219 | #define SKB_DATAREF_MASK ((1 << SKB_DATAREF_SHIFT) - 1) | |
220 | ||
221 | ||
222 | enum { | |
223 | SKB_FCLONE_UNAVAILABLE, | |
224 | SKB_FCLONE_ORIG, | |
225 | SKB_FCLONE_CLONE, | |
226 | }; | |
227 | ||
228 | enum { | |
229 | SKB_GSO_TCPV4 = 1 << 0, | |
230 | SKB_GSO_UDP = 1 << 1, | |
231 | ||
232 | /* This indicates the skb is from an untrusted source. */ | |
233 | SKB_GSO_DODGY = 1 << 2, | |
234 | ||
235 | /* This indicates the tcp segment has CWR set. */ | |
236 | SKB_GSO_TCP_ECN = 1 << 3, | |
237 | ||
238 | SKB_GSO_TCPV6 = 1 << 4, | |
239 | ||
240 | SKB_GSO_FCOE = 1 << 5, | |
241 | }; | |
242 | ||
243 | #if BITS_PER_LONG > 32 | |
244 | #define NET_SKBUFF_DATA_USES_OFFSET 1 | |
245 | #endif | |
246 | ||
247 | #ifdef NET_SKBUFF_DATA_USES_OFFSET | |
248 | typedef unsigned int sk_buff_data_t; | |
249 | #else | |
250 | typedef unsigned char *sk_buff_data_t; | |
251 | #endif | |
252 | ||
253 | /** | |
254 | * struct sk_buff - socket buffer | |
255 | * @next: Next buffer in list | |
256 | * @prev: Previous buffer in list | |
257 | * @sk: Socket we are owned by | |
258 | * @tstamp: Time we arrived | |
259 | * @dev: Device we arrived on/are leaving by | |
260 | * @transport_header: Transport layer header | |
261 | * @network_header: Network layer header | |
262 | * @mac_header: Link layer header | |
263 | * @_skb_refdst: destination entry (with norefcount bit) | |
264 | * @sp: the security path, used for xfrm | |
265 | * @cb: Control buffer. Free for use by every layer. Put private vars here | |
266 | * @len: Length of actual data | |
267 | * @data_len: Data length | |
268 | * @mac_len: Length of link layer header | |
269 | * @hdr_len: writable header length of cloned skb | |
270 | * @csum: Checksum (must include start/offset pair) | |
271 | * @csum_start: Offset from skb->head where checksumming should start | |
272 | * @csum_offset: Offset from csum_start where checksum should be stored | |
273 | * @local_df: allow local fragmentation | |
274 | * @cloned: Head may be cloned (check refcnt to be sure) | |
275 | * @nohdr: Payload reference only, must not modify header | |
276 | * @pkt_type: Packet class | |
277 | * @fclone: skbuff clone status | |
278 | * @ip_summed: Driver fed us an IP checksum | |
279 | * @priority: Packet queueing priority | |
280 | * @users: User count - see {datagram,tcp}.c | |
281 | * @protocol: Packet protocol from driver | |
282 | * @truesize: Buffer size | |
283 | * @head: Head of buffer | |
284 | * @data: Data head pointer | |
285 | * @tail: Tail pointer | |
286 | * @end: End pointer | |
287 | * @destructor: Destruct function | |
288 | * @mark: Generic packet mark | |
289 | * @nfct: Associated connection, if any | |
290 | * @ipvs_property: skbuff is owned by ipvs | |
291 | * @peeked: this packet has been seen already, so stats have been | |
292 | * done for it, don't do them again | |
293 | * @nf_trace: netfilter packet trace flag | |
294 | * @nfctinfo: Relationship of this skb to the connection | |
295 | * @nfct_reasm: netfilter conntrack re-assembly pointer | |
296 | * @nf_bridge: Saved data about a bridged frame - see br_netfilter.c | |
297 | * @skb_iif: ifindex of device we arrived on | |
298 | * @rxhash: the packet hash computed on receive | |
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 | * @dma_cookie: a cookie to one of several possible DMA operations | |
304 | * done by skb DMA functions | |
305 | * @secmark: security marking | |
306 | * @vlan_tci: vlan tag control information | |
307 | */ | |
308 | ||
309 | struct sk_buff { | |
310 | /* These two members must be first. */ | |
311 | struct sk_buff *next; | |
312 | struct sk_buff *prev; | |
313 | ||
314 | ktime_t tstamp; | |
315 | ||
316 | struct sock *sk; | |
317 | struct net_device *dev; | |
318 | ||
319 | /* | |
320 | * This is the control buffer. It is free to use for every | |
321 | * layer. Please put your private variables there. If you | |
322 | * want to keep them across layers you have to do a skb_clone() | |
323 | * first. This is owned by whoever has the skb queued ATM. | |
324 | */ | |
325 | char cb[48] __aligned(8); | |
326 | ||
327 | unsigned long _skb_refdst; | |
328 | #ifdef CONFIG_XFRM | |
329 | struct sec_path *sp; | |
330 | #endif | |
331 | unsigned int len, | |
332 | data_len; | |
333 | __u16 mac_len, | |
334 | hdr_len; | |
335 | union { | |
336 | __wsum csum; | |
337 | struct { | |
338 | __u16 csum_start; | |
339 | __u16 csum_offset; | |
340 | }; | |
341 | }; | |
342 | __u32 priority; | |
343 | kmemcheck_bitfield_begin(flags1); | |
344 | __u8 local_df:1, | |
345 | cloned:1, | |
346 | ip_summed:2, | |
347 | nohdr:1, | |
348 | nfctinfo:3; | |
349 | __u8 pkt_type:3, | |
350 | fclone:2, | |
351 | ipvs_property:1, | |
352 | peeked:1, | |
353 | nf_trace:1; | |
354 | kmemcheck_bitfield_end(flags1); | |
355 | __be16 protocol; | |
356 | ||
357 | void (*destructor)(struct sk_buff *skb); | |
358 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) | |
359 | struct nf_conntrack *nfct; | |
360 | struct sk_buff *nfct_reasm; | |
361 | #endif | |
362 | #ifdef CONFIG_BRIDGE_NETFILTER | |
363 | struct nf_bridge_info *nf_bridge; | |
364 | #endif | |
365 | ||
366 | int skb_iif; | |
367 | #ifdef CONFIG_NET_SCHED | |
368 | __u16 tc_index; /* traffic control index */ | |
369 | #ifdef CONFIG_NET_CLS_ACT | |
370 | __u16 tc_verd; /* traffic control verdict */ | |
371 | #endif | |
372 | #endif | |
373 | ||
374 | __u32 rxhash; | |
375 | ||
376 | kmemcheck_bitfield_begin(flags2); | |
377 | __u16 queue_mapping:16; | |
378 | #ifdef CONFIG_IPV6_NDISC_NODETYPE | |
379 | __u8 ndisc_nodetype:2, | |
380 | deliver_no_wcard:1; | |
381 | #else | |
382 | __u8 deliver_no_wcard:1; | |
383 | #endif | |
384 | kmemcheck_bitfield_end(flags2); | |
385 | ||
386 | /* 0/14 bit hole */ | |
387 | ||
388 | #ifdef CONFIG_NET_DMA | |
389 | dma_cookie_t dma_cookie; | |
390 | #endif | |
391 | #ifdef CONFIG_NETWORK_SECMARK | |
392 | __u32 secmark; | |
393 | #endif | |
394 | union { | |
395 | __u32 mark; | |
396 | __u32 dropcount; | |
397 | }; | |
398 | ||
399 | __u16 vlan_tci; | |
400 | ||
401 | sk_buff_data_t transport_header; | |
402 | sk_buff_data_t network_header; | |
403 | sk_buff_data_t mac_header; | |
404 | /* These elements must be at the end, see alloc_skb() for details. */ | |
405 | sk_buff_data_t tail; | |
406 | sk_buff_data_t end; | |
407 | unsigned char *head, | |
408 | *data; | |
409 | unsigned int truesize; | |
410 | atomic_t users; | |
411 | }; | |
412 | ||
413 | #ifdef __KERNEL__ | |
414 | /* | |
415 | * Handling routines are only of interest to the kernel | |
416 | */ | |
417 | #include <linux/slab.h> | |
418 | ||
419 | #include <asm/system.h> | |
420 | ||
421 | /* | |
422 | * skb might have a dst pointer attached, refcounted or not. | |
423 | * _skb_refdst low order bit is set if refcount was _not_ taken | |
424 | */ | |
425 | #define SKB_DST_NOREF 1UL | |
426 | #define SKB_DST_PTRMASK ~(SKB_DST_NOREF) | |
427 | ||
428 | /** | |
429 | * skb_dst - returns skb dst_entry | |
430 | * @skb: buffer | |
431 | * | |
432 | * Returns skb dst_entry, regardless of reference taken or not. | |
433 | */ | |
434 | static inline struct dst_entry *skb_dst(const struct sk_buff *skb) | |
435 | { | |
436 | /* If refdst was not refcounted, check we still are in a | |
437 | * rcu_read_lock section | |
438 | */ | |
439 | WARN_ON((skb->_skb_refdst & SKB_DST_NOREF) && | |
440 | !rcu_read_lock_held() && | |
441 | !rcu_read_lock_bh_held()); | |
442 | return (struct dst_entry *)(skb->_skb_refdst & SKB_DST_PTRMASK); | |
443 | } | |
444 | ||
445 | /** | |
446 | * skb_dst_set - sets skb dst | |
447 | * @skb: buffer | |
448 | * @dst: dst entry | |
449 | * | |
450 | * Sets skb dst, assuming a reference was taken on dst and should | |
451 | * be released by skb_dst_drop() | |
452 | */ | |
453 | static inline void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) | |
454 | { | |
455 | skb->_skb_refdst = (unsigned long)dst; | |
456 | } | |
457 | ||
458 | /** | |
459 | * skb_dst_set_noref - sets skb dst, without a reference | |
460 | * @skb: buffer | |
461 | * @dst: dst entry | |
462 | * | |
463 | * Sets skb dst, assuming a reference was not taken on dst | |
464 | * skb_dst_drop() should not dst_release() this dst | |
465 | */ | |
466 | static inline void skb_dst_set_noref(struct sk_buff *skb, struct dst_entry *dst) | |
467 | { | |
468 | WARN_ON(!rcu_read_lock_held() && !rcu_read_lock_bh_held()); | |
469 | skb->_skb_refdst = (unsigned long)dst | SKB_DST_NOREF; | |
470 | } | |
471 | ||
472 | /** | |
473 | * skb_dst_is_noref - Test if skb dst isnt refcounted | |
474 | * @skb: buffer | |
475 | */ | |
476 | static inline bool skb_dst_is_noref(const struct sk_buff *skb) | |
477 | { | |
478 | return (skb->_skb_refdst & SKB_DST_NOREF) && skb_dst(skb); | |
479 | } | |
480 | ||
481 | static inline struct rtable *skb_rtable(const struct sk_buff *skb) | |
482 | { | |
483 | return (struct rtable *)skb_dst(skb); | |
484 | } | |
485 | ||
486 | extern void kfree_skb(struct sk_buff *skb); | |
487 | extern void consume_skb(struct sk_buff *skb); | |
488 | extern void __kfree_skb(struct sk_buff *skb); | |
489 | extern struct sk_buff *__alloc_skb(unsigned int size, | |
490 | gfp_t priority, int fclone, int node); | |
491 | static inline struct sk_buff *alloc_skb(unsigned int size, | |
492 | gfp_t priority) | |
493 | { | |
494 | return __alloc_skb(size, priority, 0, -1); | |
495 | } | |
496 | ||
497 | static inline struct sk_buff *alloc_skb_fclone(unsigned int size, | |
498 | gfp_t priority) | |
499 | { | |
500 | return __alloc_skb(size, priority, 1, -1); | |
501 | } | |
502 | ||
503 | extern bool skb_recycle_check(struct sk_buff *skb, int skb_size); | |
504 | ||
505 | extern struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src); | |
506 | extern struct sk_buff *skb_clone(struct sk_buff *skb, | |
507 | gfp_t priority); | |
508 | extern struct sk_buff *skb_copy(const struct sk_buff *skb, | |
509 | gfp_t priority); | |
510 | extern struct sk_buff *pskb_copy(struct sk_buff *skb, | |
511 | gfp_t gfp_mask); | |
512 | extern int pskb_expand_head(struct sk_buff *skb, | |
513 | int nhead, int ntail, | |
514 | gfp_t gfp_mask); | |
515 | extern struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, | |
516 | unsigned int headroom); | |
517 | extern struct sk_buff *skb_copy_expand(const struct sk_buff *skb, | |
518 | int newheadroom, int newtailroom, | |
519 | gfp_t priority); | |
520 | extern int skb_to_sgvec(struct sk_buff *skb, | |
521 | struct scatterlist *sg, int offset, | |
522 | int len); | |
523 | extern int skb_cow_data(struct sk_buff *skb, int tailbits, | |
524 | struct sk_buff **trailer); | |
525 | extern int skb_pad(struct sk_buff *skb, int pad); | |
526 | #define dev_kfree_skb(a) consume_skb(a) | |
527 | ||
528 | extern int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb, | |
529 | int getfrag(void *from, char *to, int offset, | |
530 | int len,int odd, struct sk_buff *skb), | |
531 | void *from, int length); | |
532 | ||
533 | struct skb_seq_state { | |
534 | __u32 lower_offset; | |
535 | __u32 upper_offset; | |
536 | __u32 frag_idx; | |
537 | __u32 stepped_offset; | |
538 | struct sk_buff *root_skb; | |
539 | struct sk_buff *cur_skb; | |
540 | __u8 *frag_data; | |
541 | }; | |
542 | ||
543 | extern void skb_prepare_seq_read(struct sk_buff *skb, | |
544 | unsigned int from, unsigned int to, | |
545 | struct skb_seq_state *st); | |
546 | extern unsigned int skb_seq_read(unsigned int consumed, const u8 **data, | |
547 | struct skb_seq_state *st); | |
548 | extern void skb_abort_seq_read(struct skb_seq_state *st); | |
549 | ||
550 | extern unsigned int skb_find_text(struct sk_buff *skb, unsigned int from, | |
551 | unsigned int to, struct ts_config *config, | |
552 | struct ts_state *state); | |
553 | ||
554 | extern __u32 __skb_get_rxhash(struct sk_buff *skb); | |
555 | static inline __u32 skb_get_rxhash(struct sk_buff *skb) | |
556 | { | |
557 | if (!skb->rxhash) | |
558 | skb->rxhash = __skb_get_rxhash(skb); | |
559 | ||
560 | return skb->rxhash; | |
561 | } | |
562 | ||
563 | #ifdef NET_SKBUFF_DATA_USES_OFFSET | |
564 | static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) | |
565 | { | |
566 | return skb->head + skb->end; | |
567 | } | |
568 | #else | |
569 | static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) | |
570 | { | |
571 | return skb->end; | |
572 | } | |
573 | #endif | |
574 | ||
575 | /* Internal */ | |
576 | #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) | |
577 | ||
578 | static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb) | |
579 | { | |
580 | return &skb_shinfo(skb)->hwtstamps; | |
581 | } | |
582 | ||
583 | /** | |
584 | * skb_queue_empty - check if a queue is empty | |
585 | * @list: queue head | |
586 | * | |
587 | * Returns true if the queue is empty, false otherwise. | |
588 | */ | |
589 | static inline int skb_queue_empty(const struct sk_buff_head *list) | |
590 | { | |
591 | return list->next == (struct sk_buff *)list; | |
592 | } | |
593 | ||
594 | /** | |
595 | * skb_queue_is_last - check if skb is the last entry in the queue | |
596 | * @list: queue head | |
597 | * @skb: buffer | |
598 | * | |
599 | * Returns true if @skb is the last buffer on the list. | |
600 | */ | |
601 | static inline bool skb_queue_is_last(const struct sk_buff_head *list, | |
602 | const struct sk_buff *skb) | |
603 | { | |
604 | return skb->next == (struct sk_buff *)list; | |
605 | } | |
606 | ||
607 | /** | |
608 | * skb_queue_is_first - check if skb is the first entry in the queue | |
609 | * @list: queue head | |
610 | * @skb: buffer | |
611 | * | |
612 | * Returns true if @skb is the first buffer on the list. | |
613 | */ | |
614 | static inline bool skb_queue_is_first(const struct sk_buff_head *list, | |
615 | const struct sk_buff *skb) | |
616 | { | |
617 | return skb->prev == (struct sk_buff *)list; | |
618 | } | |
619 | ||
620 | /** | |
621 | * skb_queue_next - return the next packet in the queue | |
622 | * @list: queue head | |
623 | * @skb: current buffer | |
624 | * | |
625 | * Return the next packet in @list after @skb. It is only valid to | |
626 | * call this if skb_queue_is_last() evaluates to false. | |
627 | */ | |
628 | static inline struct sk_buff *skb_queue_next(const struct sk_buff_head *list, | |
629 | const struct sk_buff *skb) | |
630 | { | |
631 | /* This BUG_ON may seem severe, but if we just return then we | |
632 | * are going to dereference garbage. | |
633 | */ | |
634 | BUG_ON(skb_queue_is_last(list, skb)); | |
635 | return skb->next; | |
636 | } | |
637 | ||
638 | /** | |
639 | * skb_queue_prev - return the prev packet in the queue | |
640 | * @list: queue head | |
641 | * @skb: current buffer | |
642 | * | |
643 | * Return the prev packet in @list before @skb. It is only valid to | |
644 | * call this if skb_queue_is_first() evaluates to false. | |
645 | */ | |
646 | static inline struct sk_buff *skb_queue_prev(const struct sk_buff_head *list, | |
647 | const struct sk_buff *skb) | |
648 | { | |
649 | /* This BUG_ON may seem severe, but if we just return then we | |
650 | * are going to dereference garbage. | |
651 | */ | |
652 | BUG_ON(skb_queue_is_first(list, skb)); | |
653 | return skb->prev; | |
654 | } | |
655 | ||
656 | /** | |
657 | * skb_get - reference buffer | |
658 | * @skb: buffer to reference | |
659 | * | |
660 | * Makes another reference to a socket buffer and returns a pointer | |
661 | * to the buffer. | |
662 | */ | |
663 | static inline struct sk_buff *skb_get(struct sk_buff *skb) | |
664 | { | |
665 | atomic_inc(&skb->users); | |
666 | return skb; | |
667 | } | |
668 | ||
669 | /* | |
670 | * If users == 1, we are the only owner and are can avoid redundant | |
671 | * atomic change. | |
672 | */ | |
673 | ||
674 | /** | |
675 | * skb_cloned - is the buffer a clone | |
676 | * @skb: buffer to check | |
677 | * | |
678 | * Returns true if the buffer was generated with skb_clone() and is | |
679 | * one of multiple shared copies of the buffer. Cloned buffers are | |
680 | * shared data so must not be written to under normal circumstances. | |
681 | */ | |
682 | static inline int skb_cloned(const struct sk_buff *skb) | |
683 | { | |
684 | return skb->cloned && | |
685 | (atomic_read(&skb_shinfo(skb)->dataref) & SKB_DATAREF_MASK) != 1; | |
686 | } | |
687 | ||
688 | /** | |
689 | * skb_header_cloned - is the header a clone | |
690 | * @skb: buffer to check | |
691 | * | |
692 | * Returns true if modifying the header part of the buffer requires | |
693 | * the data to be copied. | |
694 | */ | |
695 | static inline int skb_header_cloned(const struct sk_buff *skb) | |
696 | { | |
697 | int dataref; | |
698 | ||
699 | if (!skb->cloned) | |
700 | return 0; | |
701 | ||
702 | dataref = atomic_read(&skb_shinfo(skb)->dataref); | |
703 | dataref = (dataref & SKB_DATAREF_MASK) - (dataref >> SKB_DATAREF_SHIFT); | |
704 | return dataref != 1; | |
705 | } | |
706 | ||
707 | /** | |
708 | * skb_header_release - release reference to header | |
709 | * @skb: buffer to operate on | |
710 | * | |
711 | * Drop a reference to the header part of the buffer. This is done | |
712 | * by acquiring a payload reference. You must not read from the header | |
713 | * part of skb->data after this. | |
714 | */ | |
715 | static inline void skb_header_release(struct sk_buff *skb) | |
716 | { | |
717 | BUG_ON(skb->nohdr); | |
718 | skb->nohdr = 1; | |
719 | atomic_add(1 << SKB_DATAREF_SHIFT, &skb_shinfo(skb)->dataref); | |
720 | } | |
721 | ||
722 | /** | |
723 | * skb_shared - is the buffer shared | |
724 | * @skb: buffer to check | |
725 | * | |
726 | * Returns true if more than one person has a reference to this | |
727 | * buffer. | |
728 | */ | |
729 | static inline int skb_shared(const struct sk_buff *skb) | |
730 | { | |
731 | return atomic_read(&skb->users) != 1; | |
732 | } | |
733 | ||
734 | /** | |
735 | * skb_share_check - check if buffer is shared and if so clone it | |
736 | * @skb: buffer to check | |
737 | * @pri: priority for memory allocation | |
738 | * | |
739 | * If the buffer is shared the buffer is cloned and the old copy | |
740 | * drops a reference. A new clone with a single reference is returned. | |
741 | * If the buffer is not shared the original buffer is returned. When | |
742 | * being called from interrupt status or with spinlocks held pri must | |
743 | * be GFP_ATOMIC. | |
744 | * | |
745 | * NULL is returned on a memory allocation failure. | |
746 | */ | |
747 | static inline struct sk_buff *skb_share_check(struct sk_buff *skb, | |
748 | gfp_t pri) | |
749 | { | |
750 | might_sleep_if(pri & __GFP_WAIT); | |
751 | if (skb_shared(skb)) { | |
752 | struct sk_buff *nskb = skb_clone(skb, pri); | |
753 | kfree_skb(skb); | |
754 | skb = nskb; | |
755 | } | |
756 | return skb; | |
757 | } | |
758 | ||
759 | /* | |
760 | * Copy shared buffers into a new sk_buff. We effectively do COW on | |
761 | * packets to handle cases where we have a local reader and forward | |
762 | * and a couple of other messy ones. The normal one is tcpdumping | |
763 | * a packet thats being forwarded. | |
764 | */ | |
765 | ||
766 | /** | |
767 | * skb_unshare - make a copy of a shared buffer | |
768 | * @skb: buffer to check | |
769 | * @pri: priority for memory allocation | |
770 | * | |
771 | * If the socket buffer is a clone then this function creates a new | |
772 | * copy of the data, drops a reference count on the old copy and returns | |
773 | * the new copy with the reference count at 1. If the buffer is not a clone | |
774 | * the original buffer is returned. When called with a spinlock held or | |
775 | * from interrupt state @pri must be %GFP_ATOMIC | |
776 | * | |
777 | * %NULL is returned on a memory allocation failure. | |
778 | */ | |
779 | static inline struct sk_buff *skb_unshare(struct sk_buff *skb, | |
780 | gfp_t pri) | |
781 | { | |
782 | might_sleep_if(pri & __GFP_WAIT); | |
783 | if (skb_cloned(skb)) { | |
784 | struct sk_buff *nskb = skb_copy(skb, pri); | |
785 | kfree_skb(skb); /* Free our shared copy */ | |
786 | skb = nskb; | |
787 | } | |
788 | return skb; | |
789 | } | |
790 | ||
791 | /** | |
792 | * skb_peek - peek at the head of an &sk_buff_head | |
793 | * @list_: list to peek at | |
794 | * | |
795 | * Peek an &sk_buff. Unlike most other operations you _MUST_ | |
796 | * be careful with this one. A peek leaves the buffer on the | |
797 | * list and someone else may run off with it. You must hold | |
798 | * the appropriate locks or have a private queue to do this. | |
799 | * | |
800 | * Returns %NULL for an empty list or a pointer to the head element. | |
801 | * The reference count is not incremented and the reference is therefore | |
802 | * volatile. Use with caution. | |
803 | */ | |
804 | static inline struct sk_buff *skb_peek(struct sk_buff_head *list_) | |
805 | { | |
806 | struct sk_buff *list = ((struct sk_buff *)list_)->next; | |
807 | if (list == (struct sk_buff *)list_) | |
808 | list = NULL; | |
809 | return list; | |
810 | } | |
811 | ||
812 | /** | |
813 | * skb_peek_tail - peek at the tail of an &sk_buff_head | |
814 | * @list_: list to peek at | |
815 | * | |
816 | * Peek an &sk_buff. Unlike most other operations you _MUST_ | |
817 | * be careful with this one. A peek leaves the buffer on the | |
818 | * list and someone else may run off with it. You must hold | |
819 | * the appropriate locks or have a private queue to do this. | |
820 | * | |
821 | * Returns %NULL for an empty list or a pointer to the tail element. | |
822 | * The reference count is not incremented and the reference is therefore | |
823 | * volatile. Use with caution. | |
824 | */ | |
825 | static inline struct sk_buff *skb_peek_tail(struct sk_buff_head *list_) | |
826 | { | |
827 | struct sk_buff *list = ((struct sk_buff *)list_)->prev; | |
828 | if (list == (struct sk_buff *)list_) | |
829 | list = NULL; | |
830 | return list; | |
831 | } | |
832 | ||
833 | /** | |
834 | * skb_queue_len - get queue length | |
835 | * @list_: list to measure | |
836 | * | |
837 | * Return the length of an &sk_buff queue. | |
838 | */ | |
839 | static inline __u32 skb_queue_len(const struct sk_buff_head *list_) | |
840 | { | |
841 | return list_->qlen; | |
842 | } | |
843 | ||
844 | /** | |
845 | * __skb_queue_head_init - initialize non-spinlock portions of sk_buff_head | |
846 | * @list: queue to initialize | |
847 | * | |
848 | * This initializes only the list and queue length aspects of | |
849 | * an sk_buff_head object. This allows to initialize the list | |
850 | * aspects of an sk_buff_head without reinitializing things like | |
851 | * the spinlock. It can also be used for on-stack sk_buff_head | |
852 | * objects where the spinlock is known to not be used. | |
853 | */ | |
854 | static inline void __skb_queue_head_init(struct sk_buff_head *list) | |
855 | { | |
856 | list->prev = list->next = (struct sk_buff *)list; | |
857 | list->qlen = 0; | |
858 | } | |
859 | ||
860 | /* | |
861 | * This function creates a split out lock class for each invocation; | |
862 | * this is needed for now since a whole lot of users of the skb-queue | |
863 | * infrastructure in drivers have different locking usage (in hardirq) | |
864 | * than the networking core (in softirq only). In the long run either the | |
865 | * network layer or drivers should need annotation to consolidate the | |
866 | * main types of usage into 3 classes. | |
867 | */ | |
868 | static inline void skb_queue_head_init(struct sk_buff_head *list) | |
869 | { | |
870 | spin_lock_init(&list->lock); | |
871 | __skb_queue_head_init(list); | |
872 | } | |
873 | ||
874 | static inline void skb_queue_head_init_class(struct sk_buff_head *list, | |
875 | struct lock_class_key *class) | |
876 | { | |
877 | skb_queue_head_init(list); | |
878 | lockdep_set_class(&list->lock, class); | |
879 | } | |
880 | ||
881 | /* | |
882 | * Insert an sk_buff on a list. | |
883 | * | |
884 | * The "__skb_xxxx()" functions are the non-atomic ones that | |
885 | * can only be called with interrupts disabled. | |
886 | */ | |
887 | extern void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list); | |
888 | static inline void __skb_insert(struct sk_buff *newsk, | |
889 | struct sk_buff *prev, struct sk_buff *next, | |
890 | struct sk_buff_head *list) | |
891 | { | |
892 | newsk->next = next; | |
893 | newsk->prev = prev; | |
894 | next->prev = prev->next = newsk; | |
895 | list->qlen++; | |
896 | } | |
897 | ||
898 | static inline void __skb_queue_splice(const struct sk_buff_head *list, | |
899 | struct sk_buff *prev, | |
900 | struct sk_buff *next) | |
901 | { | |
902 | struct sk_buff *first = list->next; | |
903 | struct sk_buff *last = list->prev; | |
904 | ||
905 | first->prev = prev; | |
906 | prev->next = first; | |
907 | ||
908 | last->next = next; | |
909 | next->prev = last; | |
910 | } | |
911 | ||
912 | /** | |
913 | * skb_queue_splice - join two skb lists, this is designed for stacks | |
914 | * @list: the new list to add | |
915 | * @head: the place to add it in the first list | |
916 | */ | |
917 | static inline void skb_queue_splice(const struct sk_buff_head *list, | |
918 | struct sk_buff_head *head) | |
919 | { | |
920 | if (!skb_queue_empty(list)) { | |
921 | __skb_queue_splice(list, (struct sk_buff *) head, head->next); | |
922 | head->qlen += list->qlen; | |
923 | } | |
924 | } | |
925 | ||
926 | /** | |
927 | * skb_queue_splice - join two skb lists and reinitialise the emptied list | |
928 | * @list: the new list to add | |
929 | * @head: the place to add it in the first list | |
930 | * | |
931 | * The list at @list is reinitialised | |
932 | */ | |
933 | static inline void skb_queue_splice_init(struct sk_buff_head *list, | |
934 | struct sk_buff_head *head) | |
935 | { | |
936 | if (!skb_queue_empty(list)) { | |
937 | __skb_queue_splice(list, (struct sk_buff *) head, head->next); | |
938 | head->qlen += list->qlen; | |
939 | __skb_queue_head_init(list); | |
940 | } | |
941 | } | |
942 | ||
943 | /** | |
944 | * skb_queue_splice_tail - join two skb lists, each list being a queue | |
945 | * @list: the new list to add | |
946 | * @head: the place to add it in the first list | |
947 | */ | |
948 | static inline void skb_queue_splice_tail(const struct sk_buff_head *list, | |
949 | struct sk_buff_head *head) | |
950 | { | |
951 | if (!skb_queue_empty(list)) { | |
952 | __skb_queue_splice(list, head->prev, (struct sk_buff *) head); | |
953 | head->qlen += list->qlen; | |
954 | } | |
955 | } | |
956 | ||
957 | /** | |
958 | * skb_queue_splice_tail - join two skb lists and reinitialise the emptied list | |
959 | * @list: the new list to add | |
960 | * @head: the place to add it in the first list | |
961 | * | |
962 | * Each of the lists is a queue. | |
963 | * The list at @list is reinitialised | |
964 | */ | |
965 | static inline void skb_queue_splice_tail_init(struct sk_buff_head *list, | |
966 | struct sk_buff_head *head) | |
967 | { | |
968 | if (!skb_queue_empty(list)) { | |
969 | __skb_queue_splice(list, head->prev, (struct sk_buff *) head); | |
970 | head->qlen += list->qlen; | |
971 | __skb_queue_head_init(list); | |
972 | } | |
973 | } | |
974 | ||
975 | /** | |
976 | * __skb_queue_after - queue a buffer at the list head | |
977 | * @list: list to use | |
978 | * @prev: place after this buffer | |
979 | * @newsk: buffer to queue | |
980 | * | |
981 | * Queue a buffer int the middle of a list. This function takes no locks | |
982 | * and you must therefore hold required locks before calling it. | |
983 | * | |
984 | * A buffer cannot be placed on two lists at the same time. | |
985 | */ | |
986 | static inline void __skb_queue_after(struct sk_buff_head *list, | |
987 | struct sk_buff *prev, | |
988 | struct sk_buff *newsk) | |
989 | { | |
990 | __skb_insert(newsk, prev, prev->next, list); | |
991 | } | |
992 | ||
993 | extern void skb_append(struct sk_buff *old, struct sk_buff *newsk, | |
994 | struct sk_buff_head *list); | |
995 | ||
996 | static inline void __skb_queue_before(struct sk_buff_head *list, | |
997 | struct sk_buff *next, | |
998 | struct sk_buff *newsk) | |
999 | { | |
1000 | __skb_insert(newsk, next->prev, next, list); | |
1001 | } | |
1002 | ||
1003 | /** | |
1004 | * __skb_queue_head - queue a buffer at the list head | |
1005 | * @list: list to use | |
1006 | * @newsk: buffer to queue | |
1007 | * | |
1008 | * Queue a buffer at the start of a list. This function takes no locks | |
1009 | * and you must therefore hold required locks before calling it. | |
1010 | * | |
1011 | * A buffer cannot be placed on two lists at the same time. | |
1012 | */ | |
1013 | extern void skb_queue_head(struct sk_buff_head *list, struct sk_buff *newsk); | |
1014 | static inline void __skb_queue_head(struct sk_buff_head *list, | |
1015 | struct sk_buff *newsk) | |
1016 | { | |
1017 | __skb_queue_after(list, (struct sk_buff *)list, newsk); | |
1018 | } | |
1019 | ||
1020 | /** | |
1021 | * __skb_queue_tail - queue a buffer at the list tail | |
1022 | * @list: list to use | |
1023 | * @newsk: buffer to queue | |
1024 | * | |
1025 | * Queue a buffer at the end of a list. This function takes no locks | |
1026 | * and you must therefore hold required locks before calling it. | |
1027 | * | |
1028 | * A buffer cannot be placed on two lists at the same time. | |
1029 | */ | |
1030 | extern void skb_queue_tail(struct sk_buff_head *list, struct sk_buff *newsk); | |
1031 | static inline void __skb_queue_tail(struct sk_buff_head *list, | |
1032 | struct sk_buff *newsk) | |
1033 | { | |
1034 | __skb_queue_before(list, (struct sk_buff *)list, newsk); | |
1035 | } | |
1036 | ||
1037 | /* | |
1038 | * remove sk_buff from list. _Must_ be called atomically, and with | |
1039 | * the list known.. | |
1040 | */ | |
1041 | extern void skb_unlink(struct sk_buff *skb, struct sk_buff_head *list); | |
1042 | static inline void __skb_unlink(struct sk_buff *skb, struct sk_buff_head *list) | |
1043 | { | |
1044 | struct sk_buff *next, *prev; | |
1045 | ||
1046 | list->qlen--; | |
1047 | next = skb->next; | |
1048 | prev = skb->prev; | |
1049 | skb->next = skb->prev = NULL; | |
1050 | next->prev = prev; | |
1051 | prev->next = next; | |
1052 | } | |
1053 | ||
1054 | /** | |
1055 | * __skb_dequeue - remove from the head of the queue | |
1056 | * @list: list to dequeue from | |
1057 | * | |
1058 | * Remove the head of the list. This function does not take any locks | |
1059 | * so must be used with appropriate locks held only. The head item is | |
1060 | * returned or %NULL if the list is empty. | |
1061 | */ | |
1062 | extern struct sk_buff *skb_dequeue(struct sk_buff_head *list); | |
1063 | static inline struct sk_buff *__skb_dequeue(struct sk_buff_head *list) | |
1064 | { | |
1065 | struct sk_buff *skb = skb_peek(list); | |
1066 | if (skb) | |
1067 | __skb_unlink(skb, list); | |
1068 | return skb; | |
1069 | } | |
1070 | ||
1071 | /** | |
1072 | * __skb_dequeue_tail - remove from the tail of the queue | |
1073 | * @list: list to dequeue from | |
1074 | * | |
1075 | * Remove the tail of the list. This function does not take any locks | |
1076 | * so must be used with appropriate locks held only. The tail item is | |
1077 | * returned or %NULL if the list is empty. | |
1078 | */ | |
1079 | extern struct sk_buff *skb_dequeue_tail(struct sk_buff_head *list); | |
1080 | static inline struct sk_buff *__skb_dequeue_tail(struct sk_buff_head *list) | |
1081 | { | |
1082 | struct sk_buff *skb = skb_peek_tail(list); | |
1083 | if (skb) | |
1084 | __skb_unlink(skb, list); | |
1085 | return skb; | |
1086 | } | |
1087 | ||
1088 | ||
1089 | static inline int skb_is_nonlinear(const struct sk_buff *skb) | |
1090 | { | |
1091 | return skb->data_len; | |
1092 | } | |
1093 | ||
1094 | static inline unsigned int skb_headlen(const struct sk_buff *skb) | |
1095 | { | |
1096 | return skb->len - skb->data_len; | |
1097 | } | |
1098 | ||
1099 | static inline int skb_pagelen(const struct sk_buff *skb) | |
1100 | { | |
1101 | int i, len = 0; | |
1102 | ||
1103 | for (i = (int)skb_shinfo(skb)->nr_frags - 1; i >= 0; i--) | |
1104 | len += skb_shinfo(skb)->frags[i].size; | |
1105 | return len + skb_headlen(skb); | |
1106 | } | |
1107 | ||
1108 | static inline void skb_fill_page_desc(struct sk_buff *skb, int i, | |
1109 | struct page *page, int off, int size) | |
1110 | { | |
1111 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
1112 | ||
1113 | frag->page = page; | |
1114 | frag->page_offset = off; | |
1115 | frag->size = size; | |
1116 | skb_shinfo(skb)->nr_frags = i + 1; | |
1117 | } | |
1118 | ||
1119 | extern void skb_add_rx_frag(struct sk_buff *skb, int i, struct page *page, | |
1120 | int off, int size); | |
1121 | ||
1122 | #define SKB_PAGE_ASSERT(skb) BUG_ON(skb_shinfo(skb)->nr_frags) | |
1123 | #define SKB_FRAG_ASSERT(skb) BUG_ON(skb_has_frag_list(skb)) | |
1124 | #define SKB_LINEAR_ASSERT(skb) BUG_ON(skb_is_nonlinear(skb)) | |
1125 | ||
1126 | #ifdef NET_SKBUFF_DATA_USES_OFFSET | |
1127 | static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) | |
1128 | { | |
1129 | return skb->head + skb->tail; | |
1130 | } | |
1131 | ||
1132 | static inline void skb_reset_tail_pointer(struct sk_buff *skb) | |
1133 | { | |
1134 | skb->tail = skb->data - skb->head; | |
1135 | } | |
1136 | ||
1137 | static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) | |
1138 | { | |
1139 | skb_reset_tail_pointer(skb); | |
1140 | skb->tail += offset; | |
1141 | } | |
1142 | #else /* NET_SKBUFF_DATA_USES_OFFSET */ | |
1143 | static inline unsigned char *skb_tail_pointer(const struct sk_buff *skb) | |
1144 | { | |
1145 | return skb->tail; | |
1146 | } | |
1147 | ||
1148 | static inline void skb_reset_tail_pointer(struct sk_buff *skb) | |
1149 | { | |
1150 | skb->tail = skb->data; | |
1151 | } | |
1152 | ||
1153 | static inline void skb_set_tail_pointer(struct sk_buff *skb, const int offset) | |
1154 | { | |
1155 | skb->tail = skb->data + offset; | |
1156 | } | |
1157 | ||
1158 | #endif /* NET_SKBUFF_DATA_USES_OFFSET */ | |
1159 | ||
1160 | /* | |
1161 | * Add data to an sk_buff | |
1162 | */ | |
1163 | extern unsigned char *skb_put(struct sk_buff *skb, unsigned int len); | |
1164 | static inline unsigned char *__skb_put(struct sk_buff *skb, unsigned int len) | |
1165 | { | |
1166 | unsigned char *tmp = skb_tail_pointer(skb); | |
1167 | SKB_LINEAR_ASSERT(skb); | |
1168 | skb->tail += len; | |
1169 | skb->len += len; | |
1170 | return tmp; | |
1171 | } | |
1172 | ||
1173 | extern unsigned char *skb_push(struct sk_buff *skb, unsigned int len); | |
1174 | static inline unsigned char *__skb_push(struct sk_buff *skb, unsigned int len) | |
1175 | { | |
1176 | skb->data -= len; | |
1177 | skb->len += len; | |
1178 | return skb->data; | |
1179 | } | |
1180 | ||
1181 | extern unsigned char *skb_pull(struct sk_buff *skb, unsigned int len); | |
1182 | static inline unsigned char *__skb_pull(struct sk_buff *skb, unsigned int len) | |
1183 | { | |
1184 | skb->len -= len; | |
1185 | BUG_ON(skb->len < skb->data_len); | |
1186 | return skb->data += len; | |
1187 | } | |
1188 | ||
1189 | static inline unsigned char *skb_pull_inline(struct sk_buff *skb, unsigned int len) | |
1190 | { | |
1191 | return unlikely(len > skb->len) ? NULL : __skb_pull(skb, len); | |
1192 | } | |
1193 | ||
1194 | extern unsigned char *__pskb_pull_tail(struct sk_buff *skb, int delta); | |
1195 | ||
1196 | static inline unsigned char *__pskb_pull(struct sk_buff *skb, unsigned int len) | |
1197 | { | |
1198 | if (len > skb_headlen(skb) && | |
1199 | !__pskb_pull_tail(skb, len - skb_headlen(skb))) | |
1200 | return NULL; | |
1201 | skb->len -= len; | |
1202 | return skb->data += len; | |
1203 | } | |
1204 | ||
1205 | static inline unsigned char *pskb_pull(struct sk_buff *skb, unsigned int len) | |
1206 | { | |
1207 | return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len); | |
1208 | } | |
1209 | ||
1210 | static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len) | |
1211 | { | |
1212 | if (likely(len <= skb_headlen(skb))) | |
1213 | return 1; | |
1214 | if (unlikely(len > skb->len)) | |
1215 | return 0; | |
1216 | return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL; | |
1217 | } | |
1218 | ||
1219 | /** | |
1220 | * skb_headroom - bytes at buffer head | |
1221 | * @skb: buffer to check | |
1222 | * | |
1223 | * Return the number of bytes of free space at the head of an &sk_buff. | |
1224 | */ | |
1225 | static inline unsigned int skb_headroom(const struct sk_buff *skb) | |
1226 | { | |
1227 | return skb->data - skb->head; | |
1228 | } | |
1229 | ||
1230 | /** | |
1231 | * skb_tailroom - bytes at buffer end | |
1232 | * @skb: buffer to check | |
1233 | * | |
1234 | * Return the number of bytes of free space at the tail of an sk_buff | |
1235 | */ | |
1236 | static inline int skb_tailroom(const struct sk_buff *skb) | |
1237 | { | |
1238 | return skb_is_nonlinear(skb) ? 0 : skb->end - skb->tail; | |
1239 | } | |
1240 | ||
1241 | /** | |
1242 | * skb_reserve - adjust headroom | |
1243 | * @skb: buffer to alter | |
1244 | * @len: bytes to move | |
1245 | * | |
1246 | * Increase the headroom of an empty &sk_buff by reducing the tail | |
1247 | * room. This is only allowed for an empty buffer. | |
1248 | */ | |
1249 | static inline void skb_reserve(struct sk_buff *skb, int len) | |
1250 | { | |
1251 | skb->data += len; | |
1252 | skb->tail += len; | |
1253 | } | |
1254 | ||
1255 | #ifdef NET_SKBUFF_DATA_USES_OFFSET | |
1256 | static inline unsigned char *skb_transport_header(const struct sk_buff *skb) | |
1257 | { | |
1258 | return skb->head + skb->transport_header; | |
1259 | } | |
1260 | ||
1261 | static inline void skb_reset_transport_header(struct sk_buff *skb) | |
1262 | { | |
1263 | skb->transport_header = skb->data - skb->head; | |
1264 | } | |
1265 | ||
1266 | static inline void skb_set_transport_header(struct sk_buff *skb, | |
1267 | const int offset) | |
1268 | { | |
1269 | skb_reset_transport_header(skb); | |
1270 | skb->transport_header += offset; | |
1271 | } | |
1272 | ||
1273 | static inline unsigned char *skb_network_header(const struct sk_buff *skb) | |
1274 | { | |
1275 | return skb->head + skb->network_header; | |
1276 | } | |
1277 | ||
1278 | static inline void skb_reset_network_header(struct sk_buff *skb) | |
1279 | { | |
1280 | skb->network_header = skb->data - skb->head; | |
1281 | } | |
1282 | ||
1283 | static inline void skb_set_network_header(struct sk_buff *skb, const int offset) | |
1284 | { | |
1285 | skb_reset_network_header(skb); | |
1286 | skb->network_header += offset; | |
1287 | } | |
1288 | ||
1289 | static inline unsigned char *skb_mac_header(const struct sk_buff *skb) | |
1290 | { | |
1291 | return skb->head + skb->mac_header; | |
1292 | } | |
1293 | ||
1294 | static inline int skb_mac_header_was_set(const struct sk_buff *skb) | |
1295 | { | |
1296 | return skb->mac_header != ~0U; | |
1297 | } | |
1298 | ||
1299 | static inline void skb_reset_mac_header(struct sk_buff *skb) | |
1300 | { | |
1301 | skb->mac_header = skb->data - skb->head; | |
1302 | } | |
1303 | ||
1304 | static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) | |
1305 | { | |
1306 | skb_reset_mac_header(skb); | |
1307 | skb->mac_header += offset; | |
1308 | } | |
1309 | ||
1310 | #else /* NET_SKBUFF_DATA_USES_OFFSET */ | |
1311 | ||
1312 | static inline unsigned char *skb_transport_header(const struct sk_buff *skb) | |
1313 | { | |
1314 | return skb->transport_header; | |
1315 | } | |
1316 | ||
1317 | static inline void skb_reset_transport_header(struct sk_buff *skb) | |
1318 | { | |
1319 | skb->transport_header = skb->data; | |
1320 | } | |
1321 | ||
1322 | static inline void skb_set_transport_header(struct sk_buff *skb, | |
1323 | const int offset) | |
1324 | { | |
1325 | skb->transport_header = skb->data + offset; | |
1326 | } | |
1327 | ||
1328 | static inline unsigned char *skb_network_header(const struct sk_buff *skb) | |
1329 | { | |
1330 | return skb->network_header; | |
1331 | } | |
1332 | ||
1333 | static inline void skb_reset_network_header(struct sk_buff *skb) | |
1334 | { | |
1335 | skb->network_header = skb->data; | |
1336 | } | |
1337 | ||
1338 | static inline void skb_set_network_header(struct sk_buff *skb, const int offset) | |
1339 | { | |
1340 | skb->network_header = skb->data + offset; | |
1341 | } | |
1342 | ||
1343 | static inline unsigned char *skb_mac_header(const struct sk_buff *skb) | |
1344 | { | |
1345 | return skb->mac_header; | |
1346 | } | |
1347 | ||
1348 | static inline int skb_mac_header_was_set(const struct sk_buff *skb) | |
1349 | { | |
1350 | return skb->mac_header != NULL; | |
1351 | } | |
1352 | ||
1353 | static inline void skb_reset_mac_header(struct sk_buff *skb) | |
1354 | { | |
1355 | skb->mac_header = skb->data; | |
1356 | } | |
1357 | ||
1358 | static inline void skb_set_mac_header(struct sk_buff *skb, const int offset) | |
1359 | { | |
1360 | skb->mac_header = skb->data + offset; | |
1361 | } | |
1362 | #endif /* NET_SKBUFF_DATA_USES_OFFSET */ | |
1363 | ||
1364 | static inline int skb_transport_offset(const struct sk_buff *skb) | |
1365 | { | |
1366 | return skb_transport_header(skb) - skb->data; | |
1367 | } | |
1368 | ||
1369 | static inline u32 skb_network_header_len(const struct sk_buff *skb) | |
1370 | { | |
1371 | return skb->transport_header - skb->network_header; | |
1372 | } | |
1373 | ||
1374 | static inline int skb_network_offset(const struct sk_buff *skb) | |
1375 | { | |
1376 | return skb_network_header(skb) - skb->data; | |
1377 | } | |
1378 | ||
1379 | static inline int pskb_network_may_pull(struct sk_buff *skb, unsigned int len) | |
1380 | { | |
1381 | return pskb_may_pull(skb, skb_network_offset(skb) + len); | |
1382 | } | |
1383 | ||
1384 | /* | |
1385 | * CPUs often take a performance hit when accessing unaligned memory | |
1386 | * locations. The actual performance hit varies, it can be small if the | |
1387 | * hardware handles it or large if we have to take an exception and fix it | |
1388 | * in software. | |
1389 | * | |
1390 | * Since an ethernet header is 14 bytes network drivers often end up with | |
1391 | * the IP header at an unaligned offset. The IP header can be aligned by | |
1392 | * shifting the start of the packet by 2 bytes. Drivers should do this | |
1393 | * with: | |
1394 | * | |
1395 | * skb_reserve(skb, NET_IP_ALIGN); | |
1396 | * | |
1397 | * The downside to this alignment of the IP header is that the DMA is now | |
1398 | * unaligned. On some architectures the cost of an unaligned DMA is high | |
1399 | * and this cost outweighs the gains made by aligning the IP header. | |
1400 | * | |
1401 | * Since this trade off varies between architectures, we allow NET_IP_ALIGN | |
1402 | * to be overridden. | |
1403 | */ | |
1404 | #ifndef NET_IP_ALIGN | |
1405 | #define NET_IP_ALIGN 2 | |
1406 | #endif | |
1407 | ||
1408 | /* | |
1409 | * The networking layer reserves some headroom in skb data (via | |
1410 | * dev_alloc_skb). This is used to avoid having to reallocate skb data when | |
1411 | * the header has to grow. In the default case, if the header has to grow | |
1412 | * 32 bytes or less we avoid the reallocation. | |
1413 | * | |
1414 | * Unfortunately this headroom changes the DMA alignment of the resulting | |
1415 | * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive | |
1416 | * on some architectures. An architecture can override this value, | |
1417 | * perhaps setting it to a cacheline in size (since that will maintain | |
1418 | * cacheline alignment of the DMA). It must be a power of 2. | |
1419 | * | |
1420 | * Various parts of the networking layer expect at least 32 bytes of | |
1421 | * headroom, you should not reduce this. | |
1422 | * | |
1423 | * Using max(32, L1_CACHE_BYTES) makes sense (especially with RPS) | |
1424 | * to reduce average number of cache lines per packet. | |
1425 | * get_rps_cpus() for example only access one 64 bytes aligned block : | |
1426 | * NET_IP_ALIGN(2) + ethernet_header(14) + IP_header(20/40) + ports(8) | |
1427 | */ | |
1428 | #ifndef NET_SKB_PAD | |
1429 | #define NET_SKB_PAD max(32, L1_CACHE_BYTES) | |
1430 | #endif | |
1431 | ||
1432 | extern int ___pskb_trim(struct sk_buff *skb, unsigned int len); | |
1433 | ||
1434 | static inline void __skb_trim(struct sk_buff *skb, unsigned int len) | |
1435 | { | |
1436 | if (unlikely(skb->data_len)) { | |
1437 | WARN_ON(1); | |
1438 | return; | |
1439 | } | |
1440 | skb->len = len; | |
1441 | skb_set_tail_pointer(skb, len); | |
1442 | } | |
1443 | ||
1444 | extern void skb_trim(struct sk_buff *skb, unsigned int len); | |
1445 | ||
1446 | static inline int __pskb_trim(struct sk_buff *skb, unsigned int len) | |
1447 | { | |
1448 | if (skb->data_len) | |
1449 | return ___pskb_trim(skb, len); | |
1450 | __skb_trim(skb, len); | |
1451 | return 0; | |
1452 | } | |
1453 | ||
1454 | static inline int pskb_trim(struct sk_buff *skb, unsigned int len) | |
1455 | { | |
1456 | return (len < skb->len) ? __pskb_trim(skb, len) : 0; | |
1457 | } | |
1458 | ||
1459 | /** | |
1460 | * pskb_trim_unique - remove end from a paged unique (not cloned) buffer | |
1461 | * @skb: buffer to alter | |
1462 | * @len: new length | |
1463 | * | |
1464 | * This is identical to pskb_trim except that the caller knows that | |
1465 | * the skb is not cloned so we should never get an error due to out- | |
1466 | * of-memory. | |
1467 | */ | |
1468 | static inline void pskb_trim_unique(struct sk_buff *skb, unsigned int len) | |
1469 | { | |
1470 | int err = pskb_trim(skb, len); | |
1471 | BUG_ON(err); | |
1472 | } | |
1473 | ||
1474 | /** | |
1475 | * skb_orphan - orphan a buffer | |
1476 | * @skb: buffer to orphan | |
1477 | * | |
1478 | * If a buffer currently has an owner then we call the owner's | |
1479 | * destructor function and make the @skb unowned. The buffer continues | |
1480 | * to exist but is no longer charged to its former owner. | |
1481 | */ | |
1482 | static inline void skb_orphan(struct sk_buff *skb) | |
1483 | { | |
1484 | if (skb->destructor) | |
1485 | skb->destructor(skb); | |
1486 | skb->destructor = NULL; | |
1487 | skb->sk = NULL; | |
1488 | } | |
1489 | ||
1490 | /** | |
1491 | * __skb_queue_purge - empty a list | |
1492 | * @list: list to empty | |
1493 | * | |
1494 | * Delete all buffers on an &sk_buff list. Each buffer is removed from | |
1495 | * the list and one reference dropped. This function does not take the | |
1496 | * list lock and the caller must hold the relevant locks to use it. | |
1497 | */ | |
1498 | extern void skb_queue_purge(struct sk_buff_head *list); | |
1499 | static inline void __skb_queue_purge(struct sk_buff_head *list) | |
1500 | { | |
1501 | struct sk_buff *skb; | |
1502 | while ((skb = __skb_dequeue(list)) != NULL) | |
1503 | kfree_skb(skb); | |
1504 | } | |
1505 | ||
1506 | /** | |
1507 | * __dev_alloc_skb - allocate an skbuff for receiving | |
1508 | * @length: length to allocate | |
1509 | * @gfp_mask: get_free_pages mask, passed to alloc_skb | |
1510 | * | |
1511 | * Allocate a new &sk_buff and assign it a usage count of one. The | |
1512 | * buffer has unspecified headroom built in. Users should allocate | |
1513 | * the headroom they think they need without accounting for the | |
1514 | * built in space. The built in space is used for optimisations. | |
1515 | * | |
1516 | * %NULL is returned if there is no free memory. | |
1517 | */ | |
1518 | static inline struct sk_buff *__dev_alloc_skb(unsigned int length, | |
1519 | gfp_t gfp_mask) | |
1520 | { | |
1521 | struct sk_buff *skb = alloc_skb(length + NET_SKB_PAD, gfp_mask); | |
1522 | if (likely(skb)) | |
1523 | skb_reserve(skb, NET_SKB_PAD); | |
1524 | return skb; | |
1525 | } | |
1526 | ||
1527 | extern struct sk_buff *dev_alloc_skb(unsigned int length); | |
1528 | ||
1529 | extern struct sk_buff *__netdev_alloc_skb(struct net_device *dev, | |
1530 | unsigned int length, gfp_t gfp_mask); | |
1531 | ||
1532 | /** | |
1533 | * netdev_alloc_skb - allocate an skbuff for rx on a specific device | |
1534 | * @dev: network device to receive on | |
1535 | * @length: length to allocate | |
1536 | * | |
1537 | * Allocate a new &sk_buff and assign it a usage count of one. The | |
1538 | * buffer has unspecified headroom built in. Users should allocate | |
1539 | * the headroom they think they need without accounting for the | |
1540 | * built in space. The built in space is used for optimisations. | |
1541 | * | |
1542 | * %NULL is returned if there is no free memory. Although this function | |
1543 | * allocates memory it can be called from an interrupt. | |
1544 | */ | |
1545 | static inline struct sk_buff *netdev_alloc_skb(struct net_device *dev, | |
1546 | unsigned int length) | |
1547 | { | |
1548 | return __netdev_alloc_skb(dev, length, GFP_ATOMIC); | |
1549 | } | |
1550 | ||
1551 | static inline struct sk_buff *netdev_alloc_skb_ip_align(struct net_device *dev, | |
1552 | unsigned int length) | |
1553 | { | |
1554 | struct sk_buff *skb = netdev_alloc_skb(dev, length + NET_IP_ALIGN); | |
1555 | ||
1556 | if (NET_IP_ALIGN && skb) | |
1557 | skb_reserve(skb, NET_IP_ALIGN); | |
1558 | return skb; | |
1559 | } | |
1560 | ||
1561 | extern struct page *__netdev_alloc_page(struct net_device *dev, gfp_t gfp_mask); | |
1562 | ||
1563 | /** | |
1564 | * netdev_alloc_page - allocate a page for ps-rx on a specific device | |
1565 | * @dev: network device to receive on | |
1566 | * | |
1567 | * Allocate a new page node local to the specified device. | |
1568 | * | |
1569 | * %NULL is returned if there is no free memory. | |
1570 | */ | |
1571 | static inline struct page *netdev_alloc_page(struct net_device *dev) | |
1572 | { | |
1573 | return __netdev_alloc_page(dev, GFP_ATOMIC); | |
1574 | } | |
1575 | ||
1576 | static inline void netdev_free_page(struct net_device *dev, struct page *page) | |
1577 | { | |
1578 | __free_page(page); | |
1579 | } | |
1580 | ||
1581 | /** | |
1582 | * skb_clone_writable - is the header of a clone writable | |
1583 | * @skb: buffer to check | |
1584 | * @len: length up to which to write | |
1585 | * | |
1586 | * Returns true if modifying the header part of the cloned buffer | |
1587 | * does not requires the data to be copied. | |
1588 | */ | |
1589 | static inline int skb_clone_writable(struct sk_buff *skb, unsigned int len) | |
1590 | { | |
1591 | return !skb_header_cloned(skb) && | |
1592 | skb_headroom(skb) + len <= skb->hdr_len; | |
1593 | } | |
1594 | ||
1595 | static inline int __skb_cow(struct sk_buff *skb, unsigned int headroom, | |
1596 | int cloned) | |
1597 | { | |
1598 | int delta = 0; | |
1599 | ||
1600 | if (headroom < NET_SKB_PAD) | |
1601 | headroom = NET_SKB_PAD; | |
1602 | if (headroom > skb_headroom(skb)) | |
1603 | delta = headroom - skb_headroom(skb); | |
1604 | ||
1605 | if (delta || cloned) | |
1606 | return pskb_expand_head(skb, ALIGN(delta, NET_SKB_PAD), 0, | |
1607 | GFP_ATOMIC); | |
1608 | return 0; | |
1609 | } | |
1610 | ||
1611 | /** | |
1612 | * skb_cow - copy header of skb when it is required | |
1613 | * @skb: buffer to cow | |
1614 | * @headroom: needed headroom | |
1615 | * | |
1616 | * If the skb passed lacks sufficient headroom or its data part | |
1617 | * is shared, data is reallocated. If reallocation fails, an error | |
1618 | * is returned and original skb is not changed. | |
1619 | * | |
1620 | * The result is skb with writable area skb->head...skb->tail | |
1621 | * and at least @headroom of space at head. | |
1622 | */ | |
1623 | static inline int skb_cow(struct sk_buff *skb, unsigned int headroom) | |
1624 | { | |
1625 | return __skb_cow(skb, headroom, skb_cloned(skb)); | |
1626 | } | |
1627 | ||
1628 | /** | |
1629 | * skb_cow_head - skb_cow but only making the head writable | |
1630 | * @skb: buffer to cow | |
1631 | * @headroom: needed headroom | |
1632 | * | |
1633 | * This function is identical to skb_cow except that we replace the | |
1634 | * skb_cloned check by skb_header_cloned. It should be used when | |
1635 | * you only need to push on some header and do not need to modify | |
1636 | * the data. | |
1637 | */ | |
1638 | static inline int skb_cow_head(struct sk_buff *skb, unsigned int headroom) | |
1639 | { | |
1640 | return __skb_cow(skb, headroom, skb_header_cloned(skb)); | |
1641 | } | |
1642 | ||
1643 | /** | |
1644 | * skb_padto - pad an skbuff up to a minimal size | |
1645 | * @skb: buffer to pad | |
1646 | * @len: minimal length | |
1647 | * | |
1648 | * Pads up a buffer to ensure the trailing bytes exist and are | |
1649 | * blanked. If the buffer already contains sufficient data it | |
1650 | * is untouched. Otherwise it is extended. Returns zero on | |
1651 | * success. The skb is freed on error. | |
1652 | */ | |
1653 | ||
1654 | static inline int skb_padto(struct sk_buff *skb, unsigned int len) | |
1655 | { | |
1656 | unsigned int size = skb->len; | |
1657 | if (likely(size >= len)) | |
1658 | return 0; | |
1659 | return skb_pad(skb, len - size); | |
1660 | } | |
1661 | ||
1662 | static inline int skb_add_data(struct sk_buff *skb, | |
1663 | char __user *from, int copy) | |
1664 | { | |
1665 | const int off = skb->len; | |
1666 | ||
1667 | if (skb->ip_summed == CHECKSUM_NONE) { | |
1668 | int err = 0; | |
1669 | __wsum csum = csum_and_copy_from_user(from, skb_put(skb, copy), | |
1670 | copy, 0, &err); | |
1671 | if (!err) { | |
1672 | skb->csum = csum_block_add(skb->csum, csum, off); | |
1673 | return 0; | |
1674 | } | |
1675 | } else if (!copy_from_user(skb_put(skb, copy), from, copy)) | |
1676 | return 0; | |
1677 | ||
1678 | __skb_trim(skb, off); | |
1679 | return -EFAULT; | |
1680 | } | |
1681 | ||
1682 | static inline int skb_can_coalesce(struct sk_buff *skb, int i, | |
1683 | struct page *page, int off) | |
1684 | { | |
1685 | if (i) { | |
1686 | struct skb_frag_struct *frag = &skb_shinfo(skb)->frags[i - 1]; | |
1687 | ||
1688 | return page == frag->page && | |
1689 | off == frag->page_offset + frag->size; | |
1690 | } | |
1691 | return 0; | |
1692 | } | |
1693 | ||
1694 | static inline int __skb_linearize(struct sk_buff *skb) | |
1695 | { | |
1696 | return __pskb_pull_tail(skb, skb->data_len) ? 0 : -ENOMEM; | |
1697 | } | |
1698 | ||
1699 | /** | |
1700 | * skb_linearize - convert paged skb to linear one | |
1701 | * @skb: buffer to linarize | |
1702 | * | |
1703 | * If there is no free memory -ENOMEM is returned, otherwise zero | |
1704 | * is returned and the old skb data released. | |
1705 | */ | |
1706 | static inline int skb_linearize(struct sk_buff *skb) | |
1707 | { | |
1708 | return skb_is_nonlinear(skb) ? __skb_linearize(skb) : 0; | |
1709 | } | |
1710 | ||
1711 | /** | |
1712 | * skb_linearize_cow - make sure skb is linear and writable | |
1713 | * @skb: buffer to process | |
1714 | * | |
1715 | * If there is no free memory -ENOMEM is returned, otherwise zero | |
1716 | * is returned and the old skb data released. | |
1717 | */ | |
1718 | static inline int skb_linearize_cow(struct sk_buff *skb) | |
1719 | { | |
1720 | return skb_is_nonlinear(skb) || skb_cloned(skb) ? | |
1721 | __skb_linearize(skb) : 0; | |
1722 | } | |
1723 | ||
1724 | /** | |
1725 | * skb_postpull_rcsum - update checksum for received skb after pull | |
1726 | * @skb: buffer to update | |
1727 | * @start: start of data before pull | |
1728 | * @len: length of data pulled | |
1729 | * | |
1730 | * After doing a pull on a received packet, you need to call this to | |
1731 | * update the CHECKSUM_COMPLETE checksum, or set ip_summed to | |
1732 | * CHECKSUM_NONE so that it can be recomputed from scratch. | |
1733 | */ | |
1734 | ||
1735 | static inline void skb_postpull_rcsum(struct sk_buff *skb, | |
1736 | const void *start, unsigned int len) | |
1737 | { | |
1738 | if (skb->ip_summed == CHECKSUM_COMPLETE) | |
1739 | skb->csum = csum_sub(skb->csum, csum_partial(start, len, 0)); | |
1740 | } | |
1741 | ||
1742 | unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len); | |
1743 | ||
1744 | /** | |
1745 | * pskb_trim_rcsum - trim received skb and update checksum | |
1746 | * @skb: buffer to trim | |
1747 | * @len: new length | |
1748 | * | |
1749 | * This is exactly the same as pskb_trim except that it ensures the | |
1750 | * checksum of received packets are still valid after the operation. | |
1751 | */ | |
1752 | ||
1753 | static inline int pskb_trim_rcsum(struct sk_buff *skb, unsigned int len) | |
1754 | { | |
1755 | if (likely(len >= skb->len)) | |
1756 | return 0; | |
1757 | if (skb->ip_summed == CHECKSUM_COMPLETE) | |
1758 | skb->ip_summed = CHECKSUM_NONE; | |
1759 | return __pskb_trim(skb, len); | |
1760 | } | |
1761 | ||
1762 | #define skb_queue_walk(queue, skb) \ | |
1763 | for (skb = (queue)->next; \ | |
1764 | prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \ | |
1765 | skb = skb->next) | |
1766 | ||
1767 | #define skb_queue_walk_safe(queue, skb, tmp) \ | |
1768 | for (skb = (queue)->next, tmp = skb->next; \ | |
1769 | skb != (struct sk_buff *)(queue); \ | |
1770 | skb = tmp, tmp = skb->next) | |
1771 | ||
1772 | #define skb_queue_walk_from(queue, skb) \ | |
1773 | for (; prefetch(skb->next), (skb != (struct sk_buff *)(queue)); \ | |
1774 | skb = skb->next) | |
1775 | ||
1776 | #define skb_queue_walk_from_safe(queue, skb, tmp) \ | |
1777 | for (tmp = skb->next; \ | |
1778 | skb != (struct sk_buff *)(queue); \ | |
1779 | skb = tmp, tmp = skb->next) | |
1780 | ||
1781 | #define skb_queue_reverse_walk(queue, skb) \ | |
1782 | for (skb = (queue)->prev; \ | |
1783 | prefetch(skb->prev), (skb != (struct sk_buff *)(queue)); \ | |
1784 | skb = skb->prev) | |
1785 | ||
1786 | ||
1787 | static inline bool skb_has_frag_list(const struct sk_buff *skb) | |
1788 | { | |
1789 | return skb_shinfo(skb)->frag_list != NULL; | |
1790 | } | |
1791 | ||
1792 | static inline void skb_frag_list_init(struct sk_buff *skb) | |
1793 | { | |
1794 | skb_shinfo(skb)->frag_list = NULL; | |
1795 | } | |
1796 | ||
1797 | static inline void skb_frag_add_head(struct sk_buff *skb, struct sk_buff *frag) | |
1798 | { | |
1799 | frag->next = skb_shinfo(skb)->frag_list; | |
1800 | skb_shinfo(skb)->frag_list = frag; | |
1801 | } | |
1802 | ||
1803 | #define skb_walk_frags(skb, iter) \ | |
1804 | for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next) | |
1805 | ||
1806 | extern struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags, | |
1807 | int *peeked, int *err); | |
1808 | extern struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, | |
1809 | int noblock, int *err); | |
1810 | extern unsigned int datagram_poll(struct file *file, struct socket *sock, | |
1811 | struct poll_table_struct *wait); | |
1812 | extern int skb_copy_datagram_iovec(const struct sk_buff *from, | |
1813 | int offset, struct iovec *to, | |
1814 | int size); | |
1815 | extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, | |
1816 | int hlen, | |
1817 | struct iovec *iov); | |
1818 | extern int skb_copy_datagram_from_iovec(struct sk_buff *skb, | |
1819 | int offset, | |
1820 | const struct iovec *from, | |
1821 | int from_offset, | |
1822 | int len); | |
1823 | extern int skb_copy_datagram_const_iovec(const struct sk_buff *from, | |
1824 | int offset, | |
1825 | const struct iovec *to, | |
1826 | int to_offset, | |
1827 | int size); | |
1828 | extern void skb_free_datagram(struct sock *sk, struct sk_buff *skb); | |
1829 | extern void skb_free_datagram_locked(struct sock *sk, | |
1830 | struct sk_buff *skb); | |
1831 | extern int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, | |
1832 | unsigned int flags); | |
1833 | extern __wsum skb_checksum(const struct sk_buff *skb, int offset, | |
1834 | int len, __wsum csum); | |
1835 | extern int skb_copy_bits(const struct sk_buff *skb, int offset, | |
1836 | void *to, int len); | |
1837 | extern int skb_store_bits(struct sk_buff *skb, int offset, | |
1838 | const void *from, int len); | |
1839 | extern __wsum skb_copy_and_csum_bits(const struct sk_buff *skb, | |
1840 | int offset, u8 *to, int len, | |
1841 | __wsum csum); | |
1842 | extern int skb_splice_bits(struct sk_buff *skb, | |
1843 | unsigned int offset, | |
1844 | struct pipe_inode_info *pipe, | |
1845 | unsigned int len, | |
1846 | unsigned int flags); | |
1847 | extern void skb_copy_and_csum_dev(const struct sk_buff *skb, u8 *to); | |
1848 | extern void skb_split(struct sk_buff *skb, | |
1849 | struct sk_buff *skb1, const u32 len); | |
1850 | extern int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, | |
1851 | int shiftlen); | |
1852 | ||
1853 | extern struct sk_buff *skb_segment(struct sk_buff *skb, int features); | |
1854 | ||
1855 | static inline void *skb_header_pointer(const struct sk_buff *skb, int offset, | |
1856 | int len, void *buffer) | |
1857 | { | |
1858 | int hlen = skb_headlen(skb); | |
1859 | ||
1860 | if (hlen - offset >= len) | |
1861 | return skb->data + offset; | |
1862 | ||
1863 | if (skb_copy_bits(skb, offset, buffer, len) < 0) | |
1864 | return NULL; | |
1865 | ||
1866 | return buffer; | |
1867 | } | |
1868 | ||
1869 | static inline void skb_copy_from_linear_data(const struct sk_buff *skb, | |
1870 | void *to, | |
1871 | const unsigned int len) | |
1872 | { | |
1873 | memcpy(to, skb->data, len); | |
1874 | } | |
1875 | ||
1876 | static inline void skb_copy_from_linear_data_offset(const struct sk_buff *skb, | |
1877 | const int offset, void *to, | |
1878 | const unsigned int len) | |
1879 | { | |
1880 | memcpy(to, skb->data + offset, len); | |
1881 | } | |
1882 | ||
1883 | static inline void skb_copy_to_linear_data(struct sk_buff *skb, | |
1884 | const void *from, | |
1885 | const unsigned int len) | |
1886 | { | |
1887 | memcpy(skb->data, from, len); | |
1888 | } | |
1889 | ||
1890 | static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb, | |
1891 | const int offset, | |
1892 | const void *from, | |
1893 | const unsigned int len) | |
1894 | { | |
1895 | memcpy(skb->data + offset, from, len); | |
1896 | } | |
1897 | ||
1898 | extern void skb_init(void); | |
1899 | ||
1900 | static inline ktime_t skb_get_ktime(const struct sk_buff *skb) | |
1901 | { | |
1902 | return skb->tstamp; | |
1903 | } | |
1904 | ||
1905 | /** | |
1906 | * skb_get_timestamp - get timestamp from a skb | |
1907 | * @skb: skb to get stamp from | |
1908 | * @stamp: pointer to struct timeval to store stamp in | |
1909 | * | |
1910 | * Timestamps are stored in the skb as offsets to a base timestamp. | |
1911 | * This function converts the offset back to a struct timeval and stores | |
1912 | * it in stamp. | |
1913 | */ | |
1914 | static inline void skb_get_timestamp(const struct sk_buff *skb, | |
1915 | struct timeval *stamp) | |
1916 | { | |
1917 | *stamp = ktime_to_timeval(skb->tstamp); | |
1918 | } | |
1919 | ||
1920 | static inline void skb_get_timestampns(const struct sk_buff *skb, | |
1921 | struct timespec *stamp) | |
1922 | { | |
1923 | *stamp = ktime_to_timespec(skb->tstamp); | |
1924 | } | |
1925 | ||
1926 | static inline void __net_timestamp(struct sk_buff *skb) | |
1927 | { | |
1928 | skb->tstamp = ktime_get_real(); | |
1929 | } | |
1930 | ||
1931 | static inline ktime_t net_timedelta(ktime_t t) | |
1932 | { | |
1933 | return ktime_sub(ktime_get_real(), t); | |
1934 | } | |
1935 | ||
1936 | static inline ktime_t net_invalid_timestamp(void) | |
1937 | { | |
1938 | return ktime_set(0, 0); | |
1939 | } | |
1940 | ||
1941 | extern void skb_timestamping_init(void); | |
1942 | ||
1943 | #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING | |
1944 | ||
1945 | extern void skb_clone_tx_timestamp(struct sk_buff *skb); | |
1946 | extern bool skb_defer_rx_timestamp(struct sk_buff *skb); | |
1947 | ||
1948 | #else /* CONFIG_NETWORK_PHY_TIMESTAMPING */ | |
1949 | ||
1950 | static inline void skb_clone_tx_timestamp(struct sk_buff *skb) | |
1951 | { | |
1952 | } | |
1953 | ||
1954 | static inline bool skb_defer_rx_timestamp(struct sk_buff *skb) | |
1955 | { | |
1956 | return false; | |
1957 | } | |
1958 | ||
1959 | #endif /* !CONFIG_NETWORK_PHY_TIMESTAMPING */ | |
1960 | ||
1961 | /** | |
1962 | * skb_complete_tx_timestamp() - deliver cloned skb with tx timestamps | |
1963 | * | |
1964 | * @skb: clone of the the original outgoing packet | |
1965 | * @hwtstamps: hardware time stamps | |
1966 | * | |
1967 | */ | |
1968 | void skb_complete_tx_timestamp(struct sk_buff *skb, | |
1969 | struct skb_shared_hwtstamps *hwtstamps); | |
1970 | ||
1971 | /** | |
1972 | * skb_tstamp_tx - queue clone of skb with send time stamps | |
1973 | * @orig_skb: the original outgoing packet | |
1974 | * @hwtstamps: hardware time stamps, may be NULL if not available | |
1975 | * | |
1976 | * If the skb has a socket associated, then this function clones the | |
1977 | * skb (thus sharing the actual data and optional structures), stores | |
1978 | * the optional hardware time stamping information (if non NULL) or | |
1979 | * generates a software time stamp (otherwise), then queues the clone | |
1980 | * to the error queue of the socket. Errors are silently ignored. | |
1981 | */ | |
1982 | extern void skb_tstamp_tx(struct sk_buff *orig_skb, | |
1983 | struct skb_shared_hwtstamps *hwtstamps); | |
1984 | ||
1985 | static inline void sw_tx_timestamp(struct sk_buff *skb) | |
1986 | { | |
1987 | if (skb_shinfo(skb)->tx_flags & SKBTX_SW_TSTAMP && | |
1988 | !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) | |
1989 | skb_tstamp_tx(skb, NULL); | |
1990 | } | |
1991 | ||
1992 | /** | |
1993 | * skb_tx_timestamp() - Driver hook for transmit timestamping | |
1994 | * | |
1995 | * Ethernet MAC Drivers should call this function in their hard_xmit() | |
1996 | * function as soon as possible after giving the sk_buff to the MAC | |
1997 | * hardware, but before freeing the sk_buff. | |
1998 | * | |
1999 | * @skb: A socket buffer. | |
2000 | */ | |
2001 | static inline void skb_tx_timestamp(struct sk_buff *skb) | |
2002 | { | |
2003 | skb_clone_tx_timestamp(skb); | |
2004 | sw_tx_timestamp(skb); | |
2005 | } | |
2006 | ||
2007 | extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); | |
2008 | extern __sum16 __skb_checksum_complete(struct sk_buff *skb); | |
2009 | ||
2010 | static inline int skb_csum_unnecessary(const struct sk_buff *skb) | |
2011 | { | |
2012 | return skb->ip_summed & CHECKSUM_UNNECESSARY; | |
2013 | } | |
2014 | ||
2015 | /** | |
2016 | * skb_checksum_complete - Calculate checksum of an entire packet | |
2017 | * @skb: packet to process | |
2018 | * | |
2019 | * This function calculates the checksum over the entire packet plus | |
2020 | * the value of skb->csum. The latter can be used to supply the | |
2021 | * checksum of a pseudo header as used by TCP/UDP. It returns the | |
2022 | * checksum. | |
2023 | * | |
2024 | * For protocols that contain complete checksums such as ICMP/TCP/UDP, | |
2025 | * this function can be used to verify that checksum on received | |
2026 | * packets. In that case the function should return zero if the | |
2027 | * checksum is correct. In particular, this function will return zero | |
2028 | * if skb->ip_summed is CHECKSUM_UNNECESSARY which indicates that the | |
2029 | * hardware has already verified the correctness of the checksum. | |
2030 | */ | |
2031 | static inline __sum16 skb_checksum_complete(struct sk_buff *skb) | |
2032 | { | |
2033 | return skb_csum_unnecessary(skb) ? | |
2034 | 0 : __skb_checksum_complete(skb); | |
2035 | } | |
2036 | ||
2037 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) | |
2038 | extern void nf_conntrack_destroy(struct nf_conntrack *nfct); | |
2039 | static inline void nf_conntrack_put(struct nf_conntrack *nfct) | |
2040 | { | |
2041 | if (nfct && atomic_dec_and_test(&nfct->use)) | |
2042 | nf_conntrack_destroy(nfct); | |
2043 | } | |
2044 | static inline void nf_conntrack_get(struct nf_conntrack *nfct) | |
2045 | { | |
2046 | if (nfct) | |
2047 | atomic_inc(&nfct->use); | |
2048 | } | |
2049 | static inline void nf_conntrack_get_reasm(struct sk_buff *skb) | |
2050 | { | |
2051 | if (skb) | |
2052 | atomic_inc(&skb->users); | |
2053 | } | |
2054 | static inline void nf_conntrack_put_reasm(struct sk_buff *skb) | |
2055 | { | |
2056 | if (skb) | |
2057 | kfree_skb(skb); | |
2058 | } | |
2059 | #endif | |
2060 | #ifdef CONFIG_BRIDGE_NETFILTER | |
2061 | static inline void nf_bridge_put(struct nf_bridge_info *nf_bridge) | |
2062 | { | |
2063 | if (nf_bridge && atomic_dec_and_test(&nf_bridge->use)) | |
2064 | kfree(nf_bridge); | |
2065 | } | |
2066 | static inline void nf_bridge_get(struct nf_bridge_info *nf_bridge) | |
2067 | { | |
2068 | if (nf_bridge) | |
2069 | atomic_inc(&nf_bridge->use); | |
2070 | } | |
2071 | #endif /* CONFIG_BRIDGE_NETFILTER */ | |
2072 | static inline void nf_reset(struct sk_buff *skb) | |
2073 | { | |
2074 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) | |
2075 | nf_conntrack_put(skb->nfct); | |
2076 | skb->nfct = NULL; | |
2077 | nf_conntrack_put_reasm(skb->nfct_reasm); | |
2078 | skb->nfct_reasm = NULL; | |
2079 | #endif | |
2080 | #ifdef CONFIG_BRIDGE_NETFILTER | |
2081 | nf_bridge_put(skb->nf_bridge); | |
2082 | skb->nf_bridge = NULL; | |
2083 | #endif | |
2084 | } | |
2085 | ||
2086 | /* Note: This doesn't put any conntrack and bridge info in dst. */ | |
2087 | static inline void __nf_copy(struct sk_buff *dst, const struct sk_buff *src) | |
2088 | { | |
2089 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) | |
2090 | dst->nfct = src->nfct; | |
2091 | nf_conntrack_get(src->nfct); | |
2092 | dst->nfctinfo = src->nfctinfo; | |
2093 | dst->nfct_reasm = src->nfct_reasm; | |
2094 | nf_conntrack_get_reasm(src->nfct_reasm); | |
2095 | #endif | |
2096 | #ifdef CONFIG_BRIDGE_NETFILTER | |
2097 | dst->nf_bridge = src->nf_bridge; | |
2098 | nf_bridge_get(src->nf_bridge); | |
2099 | #endif | |
2100 | } | |
2101 | ||
2102 | static inline void nf_copy(struct sk_buff *dst, const struct sk_buff *src) | |
2103 | { | |
2104 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) | |
2105 | nf_conntrack_put(dst->nfct); | |
2106 | nf_conntrack_put_reasm(dst->nfct_reasm); | |
2107 | #endif | |
2108 | #ifdef CONFIG_BRIDGE_NETFILTER | |
2109 | nf_bridge_put(dst->nf_bridge); | |
2110 | #endif | |
2111 | __nf_copy(dst, src); | |
2112 | } | |
2113 | ||
2114 | #ifdef CONFIG_NETWORK_SECMARK | |
2115 | static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) | |
2116 | { | |
2117 | to->secmark = from->secmark; | |
2118 | } | |
2119 | ||
2120 | static inline void skb_init_secmark(struct sk_buff *skb) | |
2121 | { | |
2122 | skb->secmark = 0; | |
2123 | } | |
2124 | #else | |
2125 | static inline void skb_copy_secmark(struct sk_buff *to, const struct sk_buff *from) | |
2126 | { } | |
2127 | ||
2128 | static inline void skb_init_secmark(struct sk_buff *skb) | |
2129 | { } | |
2130 | #endif | |
2131 | ||
2132 | static inline void skb_set_queue_mapping(struct sk_buff *skb, u16 queue_mapping) | |
2133 | { | |
2134 | skb->queue_mapping = queue_mapping; | |
2135 | } | |
2136 | ||
2137 | static inline u16 skb_get_queue_mapping(const struct sk_buff *skb) | |
2138 | { | |
2139 | return skb->queue_mapping; | |
2140 | } | |
2141 | ||
2142 | static inline void skb_copy_queue_mapping(struct sk_buff *to, const struct sk_buff *from) | |
2143 | { | |
2144 | to->queue_mapping = from->queue_mapping; | |
2145 | } | |
2146 | ||
2147 | static inline void skb_record_rx_queue(struct sk_buff *skb, u16 rx_queue) | |
2148 | { | |
2149 | skb->queue_mapping = rx_queue + 1; | |
2150 | } | |
2151 | ||
2152 | static inline u16 skb_get_rx_queue(const struct sk_buff *skb) | |
2153 | { | |
2154 | return skb->queue_mapping - 1; | |
2155 | } | |
2156 | ||
2157 | static inline bool skb_rx_queue_recorded(const struct sk_buff *skb) | |
2158 | { | |
2159 | return skb->queue_mapping != 0; | |
2160 | } | |
2161 | ||
2162 | extern u16 skb_tx_hash(const struct net_device *dev, | |
2163 | const struct sk_buff *skb); | |
2164 | ||
2165 | #ifdef CONFIG_XFRM | |
2166 | static inline struct sec_path *skb_sec_path(struct sk_buff *skb) | |
2167 | { | |
2168 | return skb->sp; | |
2169 | } | |
2170 | #else | |
2171 | static inline struct sec_path *skb_sec_path(struct sk_buff *skb) | |
2172 | { | |
2173 | return NULL; | |
2174 | } | |
2175 | #endif | |
2176 | ||
2177 | static inline int skb_is_gso(const struct sk_buff *skb) | |
2178 | { | |
2179 | return skb_shinfo(skb)->gso_size; | |
2180 | } | |
2181 | ||
2182 | static inline int skb_is_gso_v6(const struct sk_buff *skb) | |
2183 | { | |
2184 | return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6; | |
2185 | } | |
2186 | ||
2187 | extern void __skb_warn_lro_forwarding(const struct sk_buff *skb); | |
2188 | ||
2189 | static inline bool skb_warn_if_lro(const struct sk_buff *skb) | |
2190 | { | |
2191 | /* LRO sets gso_size but not gso_type, whereas if GSO is really | |
2192 | * wanted then gso_type will be set. */ | |
2193 | struct skb_shared_info *shinfo = skb_shinfo(skb); | |
2194 | if (skb_is_nonlinear(skb) && shinfo->gso_size != 0 && | |
2195 | unlikely(shinfo->gso_type == 0)) { | |
2196 | __skb_warn_lro_forwarding(skb); | |
2197 | return true; | |
2198 | } | |
2199 | return false; | |
2200 | } | |
2201 | ||
2202 | static inline void skb_forward_csum(struct sk_buff *skb) | |
2203 | { | |
2204 | /* Unfortunately we don't support this one. Any brave souls? */ | |
2205 | if (skb->ip_summed == CHECKSUM_COMPLETE) | |
2206 | skb->ip_summed = CHECKSUM_NONE; | |
2207 | } | |
2208 | ||
2209 | /** | |
2210 | * skb_checksum_none_assert - make sure skb ip_summed is CHECKSUM_NONE | |
2211 | * @skb: skb to check | |
2212 | * | |
2213 | * fresh skbs have their ip_summed set to CHECKSUM_NONE. | |
2214 | * Instead of forcing ip_summed to CHECKSUM_NONE, we can | |
2215 | * use this helper, to document places where we make this assertion. | |
2216 | */ | |
2217 | static inline void skb_checksum_none_assert(struct sk_buff *skb) | |
2218 | { | |
2219 | #ifdef DEBUG | |
2220 | BUG_ON(skb->ip_summed != CHECKSUM_NONE); | |
2221 | #endif | |
2222 | } | |
2223 | ||
2224 | bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off); | |
2225 | #endif /* __KERNEL__ */ | |
2226 | #endif /* _LINUX_SKBUFF_H */ |