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1da177e4 LT |
1 | /* |
2 | * xfrm algorithm interface | |
3 | * | |
4 | * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License as published by the Free | |
8 | * Software Foundation; either version 2 of the License, or (at your option) | |
9 | * any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/config.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/pfkeyv2.h> | |
16 | #include <linux/crypto.h> | |
17 | #include <net/xfrm.h> | |
18 | #if defined(CONFIG_INET_AH) || defined(CONFIG_INET_AH_MODULE) || defined(CONFIG_INET6_AH) || defined(CONFIG_INET6_AH_MODULE) | |
19 | #include <net/ah.h> | |
20 | #endif | |
21 | #if defined(CONFIG_INET_ESP) || defined(CONFIG_INET_ESP_MODULE) || defined(CONFIG_INET6_ESP) || defined(CONFIG_INET6_ESP_MODULE) | |
22 | #include <net/esp.h> | |
23 | #endif | |
24 | #include <asm/scatterlist.h> | |
25 | ||
26 | /* | |
27 | * Algorithms supported by IPsec. These entries contain properties which | |
28 | * are used in key negotiation and xfrm processing, and are used to verify | |
29 | * that instantiated crypto transforms have correct parameters for IPsec | |
30 | * purposes. | |
31 | */ | |
32 | static struct xfrm_algo_desc aalg_list[] = { | |
33 | { | |
34 | .name = "digest_null", | |
35 | ||
36 | .uinfo = { | |
37 | .auth = { | |
38 | .icv_truncbits = 0, | |
39 | .icv_fullbits = 0, | |
40 | } | |
41 | }, | |
42 | ||
43 | .desc = { | |
44 | .sadb_alg_id = SADB_X_AALG_NULL, | |
45 | .sadb_alg_ivlen = 0, | |
46 | .sadb_alg_minbits = 0, | |
47 | .sadb_alg_maxbits = 0 | |
48 | } | |
49 | }, | |
50 | { | |
51 | .name = "md5", | |
52 | ||
53 | .uinfo = { | |
54 | .auth = { | |
55 | .icv_truncbits = 96, | |
56 | .icv_fullbits = 128, | |
57 | } | |
58 | }, | |
59 | ||
60 | .desc = { | |
61 | .sadb_alg_id = SADB_AALG_MD5HMAC, | |
62 | .sadb_alg_ivlen = 0, | |
63 | .sadb_alg_minbits = 128, | |
64 | .sadb_alg_maxbits = 128 | |
65 | } | |
66 | }, | |
67 | { | |
68 | .name = "sha1", | |
69 | ||
70 | .uinfo = { | |
71 | .auth = { | |
72 | .icv_truncbits = 96, | |
73 | .icv_fullbits = 160, | |
74 | } | |
75 | }, | |
76 | ||
77 | .desc = { | |
78 | .sadb_alg_id = SADB_AALG_SHA1HMAC, | |
79 | .sadb_alg_ivlen = 0, | |
80 | .sadb_alg_minbits = 160, | |
81 | .sadb_alg_maxbits = 160 | |
82 | } | |
83 | }, | |
84 | { | |
85 | .name = "sha256", | |
86 | ||
87 | .uinfo = { | |
88 | .auth = { | |
89 | .icv_truncbits = 96, | |
90 | .icv_fullbits = 256, | |
91 | } | |
92 | }, | |
93 | ||
94 | .desc = { | |
95 | .sadb_alg_id = SADB_X_AALG_SHA2_256HMAC, | |
96 | .sadb_alg_ivlen = 0, | |
97 | .sadb_alg_minbits = 256, | |
98 | .sadb_alg_maxbits = 256 | |
99 | } | |
100 | }, | |
101 | { | |
102 | .name = "ripemd160", | |
103 | ||
104 | .uinfo = { | |
105 | .auth = { | |
106 | .icv_truncbits = 96, | |
107 | .icv_fullbits = 160, | |
108 | } | |
109 | }, | |
110 | ||
111 | .desc = { | |
112 | .sadb_alg_id = SADB_X_AALG_RIPEMD160HMAC, | |
113 | .sadb_alg_ivlen = 0, | |
114 | .sadb_alg_minbits = 160, | |
115 | .sadb_alg_maxbits = 160 | |
116 | } | |
117 | }, | |
118 | }; | |
119 | ||
120 | static struct xfrm_algo_desc ealg_list[] = { | |
121 | { | |
122 | .name = "cipher_null", | |
123 | ||
124 | .uinfo = { | |
125 | .encr = { | |
126 | .blockbits = 8, | |
127 | .defkeybits = 0, | |
128 | } | |
129 | }, | |
130 | ||
131 | .desc = { | |
132 | .sadb_alg_id = SADB_EALG_NULL, | |
133 | .sadb_alg_ivlen = 0, | |
134 | .sadb_alg_minbits = 0, | |
135 | .sadb_alg_maxbits = 0 | |
136 | } | |
137 | }, | |
138 | { | |
139 | .name = "des", | |
140 | ||
141 | .uinfo = { | |
142 | .encr = { | |
143 | .blockbits = 64, | |
144 | .defkeybits = 64, | |
145 | } | |
146 | }, | |
147 | ||
148 | .desc = { | |
149 | .sadb_alg_id = SADB_EALG_DESCBC, | |
150 | .sadb_alg_ivlen = 8, | |
151 | .sadb_alg_minbits = 64, | |
152 | .sadb_alg_maxbits = 64 | |
153 | } | |
154 | }, | |
155 | { | |
156 | .name = "des3_ede", | |
157 | ||
158 | .uinfo = { | |
159 | .encr = { | |
160 | .blockbits = 64, | |
161 | .defkeybits = 192, | |
162 | } | |
163 | }, | |
164 | ||
165 | .desc = { | |
166 | .sadb_alg_id = SADB_EALG_3DESCBC, | |
167 | .sadb_alg_ivlen = 8, | |
168 | .sadb_alg_minbits = 192, | |
169 | .sadb_alg_maxbits = 192 | |
170 | } | |
171 | }, | |
172 | { | |
173 | .name = "cast128", | |
174 | ||
175 | .uinfo = { | |
176 | .encr = { | |
177 | .blockbits = 64, | |
178 | .defkeybits = 128, | |
179 | } | |
180 | }, | |
181 | ||
182 | .desc = { | |
183 | .sadb_alg_id = SADB_X_EALG_CASTCBC, | |
184 | .sadb_alg_ivlen = 8, | |
185 | .sadb_alg_minbits = 40, | |
186 | .sadb_alg_maxbits = 128 | |
187 | } | |
188 | }, | |
189 | { | |
190 | .name = "blowfish", | |
191 | ||
192 | .uinfo = { | |
193 | .encr = { | |
194 | .blockbits = 64, | |
195 | .defkeybits = 128, | |
196 | } | |
197 | }, | |
198 | ||
199 | .desc = { | |
200 | .sadb_alg_id = SADB_X_EALG_BLOWFISHCBC, | |
201 | .sadb_alg_ivlen = 8, | |
202 | .sadb_alg_minbits = 40, | |
203 | .sadb_alg_maxbits = 448 | |
204 | } | |
205 | }, | |
206 | { | |
207 | .name = "aes", | |
208 | ||
209 | .uinfo = { | |
210 | .encr = { | |
211 | .blockbits = 128, | |
212 | .defkeybits = 128, | |
213 | } | |
214 | }, | |
215 | ||
216 | .desc = { | |
217 | .sadb_alg_id = SADB_X_EALG_AESCBC, | |
218 | .sadb_alg_ivlen = 8, | |
219 | .sadb_alg_minbits = 128, | |
220 | .sadb_alg_maxbits = 256 | |
221 | } | |
222 | }, | |
223 | { | |
224 | .name = "serpent", | |
225 | ||
226 | .uinfo = { | |
227 | .encr = { | |
228 | .blockbits = 128, | |
229 | .defkeybits = 128, | |
230 | } | |
231 | }, | |
232 | ||
233 | .desc = { | |
234 | .sadb_alg_id = SADB_X_EALG_SERPENTCBC, | |
235 | .sadb_alg_ivlen = 8, | |
236 | .sadb_alg_minbits = 128, | |
237 | .sadb_alg_maxbits = 256, | |
238 | } | |
239 | }, | |
240 | { | |
241 | .name = "twofish", | |
242 | ||
243 | .uinfo = { | |
244 | .encr = { | |
245 | .blockbits = 128, | |
246 | .defkeybits = 128, | |
247 | } | |
248 | }, | |
249 | ||
250 | .desc = { | |
251 | .sadb_alg_id = SADB_X_EALG_TWOFISHCBC, | |
252 | .sadb_alg_ivlen = 8, | |
253 | .sadb_alg_minbits = 128, | |
254 | .sadb_alg_maxbits = 256 | |
255 | } | |
256 | }, | |
257 | }; | |
258 | ||
259 | static struct xfrm_algo_desc calg_list[] = { | |
260 | { | |
261 | .name = "deflate", | |
262 | .uinfo = { | |
263 | .comp = { | |
264 | .threshold = 90, | |
265 | } | |
266 | }, | |
267 | .desc = { .sadb_alg_id = SADB_X_CALG_DEFLATE } | |
268 | }, | |
269 | { | |
270 | .name = "lzs", | |
271 | .uinfo = { | |
272 | .comp = { | |
273 | .threshold = 90, | |
274 | } | |
275 | }, | |
276 | .desc = { .sadb_alg_id = SADB_X_CALG_LZS } | |
277 | }, | |
278 | { | |
279 | .name = "lzjh", | |
280 | .uinfo = { | |
281 | .comp = { | |
282 | .threshold = 50, | |
283 | } | |
284 | }, | |
285 | .desc = { .sadb_alg_id = SADB_X_CALG_LZJH } | |
286 | }, | |
287 | }; | |
288 | ||
289 | static inline int aalg_entries(void) | |
290 | { | |
291 | return ARRAY_SIZE(aalg_list); | |
292 | } | |
293 | ||
294 | static inline int ealg_entries(void) | |
295 | { | |
296 | return ARRAY_SIZE(ealg_list); | |
297 | } | |
298 | ||
299 | static inline int calg_entries(void) | |
300 | { | |
301 | return ARRAY_SIZE(calg_list); | |
302 | } | |
303 | ||
304 | /* Todo: generic iterators */ | |
305 | struct xfrm_algo_desc *xfrm_aalg_get_byid(int alg_id) | |
306 | { | |
307 | int i; | |
308 | ||
309 | for (i = 0; i < aalg_entries(); i++) { | |
310 | if (aalg_list[i].desc.sadb_alg_id == alg_id) { | |
311 | if (aalg_list[i].available) | |
312 | return &aalg_list[i]; | |
313 | else | |
314 | break; | |
315 | } | |
316 | } | |
317 | return NULL; | |
318 | } | |
319 | EXPORT_SYMBOL_GPL(xfrm_aalg_get_byid); | |
320 | ||
321 | struct xfrm_algo_desc *xfrm_ealg_get_byid(int alg_id) | |
322 | { | |
323 | int i; | |
324 | ||
325 | for (i = 0; i < ealg_entries(); i++) { | |
326 | if (ealg_list[i].desc.sadb_alg_id == alg_id) { | |
327 | if (ealg_list[i].available) | |
328 | return &ealg_list[i]; | |
329 | else | |
330 | break; | |
331 | } | |
332 | } | |
333 | return NULL; | |
334 | } | |
335 | EXPORT_SYMBOL_GPL(xfrm_ealg_get_byid); | |
336 | ||
337 | struct xfrm_algo_desc *xfrm_calg_get_byid(int alg_id) | |
338 | { | |
339 | int i; | |
340 | ||
341 | for (i = 0; i < calg_entries(); i++) { | |
342 | if (calg_list[i].desc.sadb_alg_id == alg_id) { | |
343 | if (calg_list[i].available) | |
344 | return &calg_list[i]; | |
345 | else | |
346 | break; | |
347 | } | |
348 | } | |
349 | return NULL; | |
350 | } | |
351 | EXPORT_SYMBOL_GPL(xfrm_calg_get_byid); | |
352 | ||
353 | static struct xfrm_algo_desc *xfrm_get_byname(struct xfrm_algo_desc *list, | |
354 | int entries, char *name, | |
355 | int probe) | |
356 | { | |
357 | int i, status; | |
358 | ||
359 | if (!name) | |
360 | return NULL; | |
361 | ||
362 | for (i = 0; i < entries; i++) { | |
363 | if (strcmp(name, list[i].name)) | |
364 | continue; | |
365 | ||
366 | if (list[i].available) | |
367 | return &list[i]; | |
368 | ||
369 | if (!probe) | |
370 | break; | |
371 | ||
372 | status = crypto_alg_available(name, 0); | |
373 | if (!status) | |
374 | break; | |
375 | ||
376 | list[i].available = status; | |
377 | return &list[i]; | |
378 | } | |
379 | return NULL; | |
380 | } | |
381 | ||
382 | struct xfrm_algo_desc *xfrm_aalg_get_byname(char *name, int probe) | |
383 | { | |
384 | return xfrm_get_byname(aalg_list, aalg_entries(), name, probe); | |
385 | } | |
386 | EXPORT_SYMBOL_GPL(xfrm_aalg_get_byname); | |
387 | ||
388 | struct xfrm_algo_desc *xfrm_ealg_get_byname(char *name, int probe) | |
389 | { | |
390 | return xfrm_get_byname(ealg_list, ealg_entries(), name, probe); | |
391 | } | |
392 | EXPORT_SYMBOL_GPL(xfrm_ealg_get_byname); | |
393 | ||
394 | struct xfrm_algo_desc *xfrm_calg_get_byname(char *name, int probe) | |
395 | { | |
396 | return xfrm_get_byname(calg_list, calg_entries(), name, probe); | |
397 | } | |
398 | EXPORT_SYMBOL_GPL(xfrm_calg_get_byname); | |
399 | ||
400 | struct xfrm_algo_desc *xfrm_aalg_get_byidx(unsigned int idx) | |
401 | { | |
402 | if (idx >= aalg_entries()) | |
403 | return NULL; | |
404 | ||
405 | return &aalg_list[idx]; | |
406 | } | |
407 | EXPORT_SYMBOL_GPL(xfrm_aalg_get_byidx); | |
408 | ||
409 | struct xfrm_algo_desc *xfrm_ealg_get_byidx(unsigned int idx) | |
410 | { | |
411 | if (idx >= ealg_entries()) | |
412 | return NULL; | |
413 | ||
414 | return &ealg_list[idx]; | |
415 | } | |
416 | EXPORT_SYMBOL_GPL(xfrm_ealg_get_byidx); | |
417 | ||
418 | /* | |
419 | * Probe for the availability of crypto algorithms, and set the available | |
420 | * flag for any algorithms found on the system. This is typically called by | |
421 | * pfkey during userspace SA add, update or register. | |
422 | */ | |
423 | void xfrm_probe_algs(void) | |
424 | { | |
425 | #ifdef CONFIG_CRYPTO | |
426 | int i, status; | |
427 | ||
428 | BUG_ON(in_softirq()); | |
429 | ||
430 | for (i = 0; i < aalg_entries(); i++) { | |
431 | status = crypto_alg_available(aalg_list[i].name, 0); | |
432 | if (aalg_list[i].available != status) | |
433 | aalg_list[i].available = status; | |
434 | } | |
435 | ||
436 | for (i = 0; i < ealg_entries(); i++) { | |
437 | status = crypto_alg_available(ealg_list[i].name, 0); | |
438 | if (ealg_list[i].available != status) | |
439 | ealg_list[i].available = status; | |
440 | } | |
441 | ||
442 | for (i = 0; i < calg_entries(); i++) { | |
443 | status = crypto_alg_available(calg_list[i].name, 0); | |
444 | if (calg_list[i].available != status) | |
445 | calg_list[i].available = status; | |
446 | } | |
447 | #endif | |
448 | } | |
449 | EXPORT_SYMBOL_GPL(xfrm_probe_algs); | |
450 | ||
451 | int xfrm_count_auth_supported(void) | |
452 | { | |
453 | int i, n; | |
454 | ||
455 | for (i = 0, n = 0; i < aalg_entries(); i++) | |
456 | if (aalg_list[i].available) | |
457 | n++; | |
458 | return n; | |
459 | } | |
460 | EXPORT_SYMBOL_GPL(xfrm_count_auth_supported); | |
461 | ||
462 | int xfrm_count_enc_supported(void) | |
463 | { | |
464 | int i, n; | |
465 | ||
466 | for (i = 0, n = 0; i < ealg_entries(); i++) | |
467 | if (ealg_list[i].available) | |
468 | n++; | |
469 | return n; | |
470 | } | |
471 | EXPORT_SYMBOL_GPL(xfrm_count_enc_supported); | |
472 | ||
473 | /* Move to common area: it is shared with AH. */ | |
474 | ||
475 | void skb_icv_walk(const struct sk_buff *skb, struct crypto_tfm *tfm, | |
476 | int offset, int len, icv_update_fn_t icv_update) | |
477 | { | |
478 | int start = skb_headlen(skb); | |
479 | int i, copy = start - offset; | |
480 | struct scatterlist sg; | |
481 | ||
482 | /* Checksum header. */ | |
483 | if (copy > 0) { | |
484 | if (copy > len) | |
485 | copy = len; | |
486 | ||
487 | sg.page = virt_to_page(skb->data + offset); | |
488 | sg.offset = (unsigned long)(skb->data + offset) % PAGE_SIZE; | |
489 | sg.length = copy; | |
490 | ||
491 | icv_update(tfm, &sg, 1); | |
492 | ||
493 | if ((len -= copy) == 0) | |
494 | return; | |
495 | offset += copy; | |
496 | } | |
497 | ||
498 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { | |
499 | int end; | |
500 | ||
501 | BUG_TRAP(start <= offset + len); | |
502 | ||
503 | end = start + skb_shinfo(skb)->frags[i].size; | |
504 | if ((copy = end - offset) > 0) { | |
505 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
506 | ||
507 | if (copy > len) | |
508 | copy = len; | |
509 | ||
510 | sg.page = frag->page; | |
511 | sg.offset = frag->page_offset + offset-start; | |
512 | sg.length = copy; | |
513 | ||
514 | icv_update(tfm, &sg, 1); | |
515 | ||
516 | if (!(len -= copy)) | |
517 | return; | |
518 | offset += copy; | |
519 | } | |
520 | start = end; | |
521 | } | |
522 | ||
523 | if (skb_shinfo(skb)->frag_list) { | |
524 | struct sk_buff *list = skb_shinfo(skb)->frag_list; | |
525 | ||
526 | for (; list; list = list->next) { | |
527 | int end; | |
528 | ||
529 | BUG_TRAP(start <= offset + len); | |
530 | ||
531 | end = start + list->len; | |
532 | if ((copy = end - offset) > 0) { | |
533 | if (copy > len) | |
534 | copy = len; | |
535 | skb_icv_walk(list, tfm, offset-start, copy, icv_update); | |
536 | if ((len -= copy) == 0) | |
537 | return; | |
538 | offset += copy; | |
539 | } | |
540 | start = end; | |
541 | } | |
542 | } | |
543 | if (len) | |
544 | BUG(); | |
545 | } | |
546 | EXPORT_SYMBOL_GPL(skb_icv_walk); | |
547 | ||
548 | #if defined(CONFIG_INET_ESP) || defined(CONFIG_INET_ESP_MODULE) || defined(CONFIG_INET6_ESP) || defined(CONFIG_INET6_ESP_MODULE) | |
549 | ||
550 | /* Looking generic it is not used in another places. */ | |
551 | ||
552 | int | |
553 | skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) | |
554 | { | |
555 | int start = skb_headlen(skb); | |
556 | int i, copy = start - offset; | |
557 | int elt = 0; | |
558 | ||
559 | if (copy > 0) { | |
560 | if (copy > len) | |
561 | copy = len; | |
562 | sg[elt].page = virt_to_page(skb->data + offset); | |
563 | sg[elt].offset = (unsigned long)(skb->data + offset) % PAGE_SIZE; | |
564 | sg[elt].length = copy; | |
565 | elt++; | |
566 | if ((len -= copy) == 0) | |
567 | return elt; | |
568 | offset += copy; | |
569 | } | |
570 | ||
571 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { | |
572 | int end; | |
573 | ||
574 | BUG_TRAP(start <= offset + len); | |
575 | ||
576 | end = start + skb_shinfo(skb)->frags[i].size; | |
577 | if ((copy = end - offset) > 0) { | |
578 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
579 | ||
580 | if (copy > len) | |
581 | copy = len; | |
582 | sg[elt].page = frag->page; | |
583 | sg[elt].offset = frag->page_offset+offset-start; | |
584 | sg[elt].length = copy; | |
585 | elt++; | |
586 | if (!(len -= copy)) | |
587 | return elt; | |
588 | offset += copy; | |
589 | } | |
590 | start = end; | |
591 | } | |
592 | ||
593 | if (skb_shinfo(skb)->frag_list) { | |
594 | struct sk_buff *list = skb_shinfo(skb)->frag_list; | |
595 | ||
596 | for (; list; list = list->next) { | |
597 | int end; | |
598 | ||
599 | BUG_TRAP(start <= offset + len); | |
600 | ||
601 | end = start + list->len; | |
602 | if ((copy = end - offset) > 0) { | |
603 | if (copy > len) | |
604 | copy = len; | |
605 | elt += skb_to_sgvec(list, sg+elt, offset - start, copy); | |
606 | if ((len -= copy) == 0) | |
607 | return elt; | |
608 | offset += copy; | |
609 | } | |
610 | start = end; | |
611 | } | |
612 | } | |
613 | if (len) | |
614 | BUG(); | |
615 | return elt; | |
616 | } | |
617 | EXPORT_SYMBOL_GPL(skb_to_sgvec); | |
618 | ||
619 | /* Check that skb data bits are writable. If they are not, copy data | |
620 | * to newly created private area. If "tailbits" is given, make sure that | |
621 | * tailbits bytes beyond current end of skb are writable. | |
622 | * | |
623 | * Returns amount of elements of scatterlist to load for subsequent | |
624 | * transformations and pointer to writable trailer skb. | |
625 | */ | |
626 | ||
627 | int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer) | |
628 | { | |
629 | int copyflag; | |
630 | int elt; | |
631 | struct sk_buff *skb1, **skb_p; | |
632 | ||
633 | /* If skb is cloned or its head is paged, reallocate | |
634 | * head pulling out all the pages (pages are considered not writable | |
635 | * at the moment even if they are anonymous). | |
636 | */ | |
637 | if ((skb_cloned(skb) || skb_shinfo(skb)->nr_frags) && | |
638 | __pskb_pull_tail(skb, skb_pagelen(skb)-skb_headlen(skb)) == NULL) | |
639 | return -ENOMEM; | |
640 | ||
641 | /* Easy case. Most of packets will go this way. */ | |
642 | if (!skb_shinfo(skb)->frag_list) { | |
643 | /* A little of trouble, not enough of space for trailer. | |
644 | * This should not happen, when stack is tuned to generate | |
645 | * good frames. OK, on miss we reallocate and reserve even more | |
646 | * space, 128 bytes is fair. */ | |
647 | ||
648 | if (skb_tailroom(skb) < tailbits && | |
649 | pskb_expand_head(skb, 0, tailbits-skb_tailroom(skb)+128, GFP_ATOMIC)) | |
650 | return -ENOMEM; | |
651 | ||
652 | /* Voila! */ | |
653 | *trailer = skb; | |
654 | return 1; | |
655 | } | |
656 | ||
657 | /* Misery. We are in troubles, going to mincer fragments... */ | |
658 | ||
659 | elt = 1; | |
660 | skb_p = &skb_shinfo(skb)->frag_list; | |
661 | copyflag = 0; | |
662 | ||
663 | while ((skb1 = *skb_p) != NULL) { | |
664 | int ntail = 0; | |
665 | ||
666 | /* The fragment is partially pulled by someone, | |
667 | * this can happen on input. Copy it and everything | |
668 | * after it. */ | |
669 | ||
670 | if (skb_shared(skb1)) | |
671 | copyflag = 1; | |
672 | ||
673 | /* If the skb is the last, worry about trailer. */ | |
674 | ||
675 | if (skb1->next == NULL && tailbits) { | |
676 | if (skb_shinfo(skb1)->nr_frags || | |
677 | skb_shinfo(skb1)->frag_list || | |
678 | skb_tailroom(skb1) < tailbits) | |
679 | ntail = tailbits + 128; | |
680 | } | |
681 | ||
682 | if (copyflag || | |
683 | skb_cloned(skb1) || | |
684 | ntail || | |
685 | skb_shinfo(skb1)->nr_frags || | |
686 | skb_shinfo(skb1)->frag_list) { | |
687 | struct sk_buff *skb2; | |
688 | ||
689 | /* Fuck, we are miserable poor guys... */ | |
690 | if (ntail == 0) | |
691 | skb2 = skb_copy(skb1, GFP_ATOMIC); | |
692 | else | |
693 | skb2 = skb_copy_expand(skb1, | |
694 | skb_headroom(skb1), | |
695 | ntail, | |
696 | GFP_ATOMIC); | |
697 | if (unlikely(skb2 == NULL)) | |
698 | return -ENOMEM; | |
699 | ||
700 | if (skb1->sk) | |
d4810200 | 701 | skb_set_owner_w(skb2, skb1->sk); |
1da177e4 LT |
702 | |
703 | /* Looking around. Are we still alive? | |
704 | * OK, link new skb, drop old one */ | |
705 | ||
706 | skb2->next = skb1->next; | |
707 | *skb_p = skb2; | |
708 | kfree_skb(skb1); | |
709 | skb1 = skb2; | |
710 | } | |
711 | elt++; | |
712 | *trailer = skb1; | |
713 | skb_p = &skb1->next; | |
714 | } | |
715 | ||
716 | return elt; | |
717 | } | |
718 | EXPORT_SYMBOL_GPL(skb_cow_data); | |
719 | ||
720 | void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len) | |
721 | { | |
722 | if (tail != skb) { | |
723 | skb->data_len += len; | |
724 | skb->len += len; | |
725 | } | |
726 | return skb_put(tail, len); | |
727 | } | |
728 | EXPORT_SYMBOL_GPL(pskb_put); | |
729 | #endif |