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Commit | Line | Data |
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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 | ||
1da177e4 LT |
12 | #include <linux/module.h> |
13 | #include <linux/kernel.h> | |
14 | #include <linux/pfkeyv2.h> | |
15 | #include <linux/crypto.h> | |
16 | #include <net/xfrm.h> | |
17 | #if defined(CONFIG_INET_AH) || defined(CONFIG_INET_AH_MODULE) || defined(CONFIG_INET6_AH) || defined(CONFIG_INET6_AH_MODULE) | |
18 | #include <net/ah.h> | |
19 | #endif | |
20 | #if defined(CONFIG_INET_ESP) || defined(CONFIG_INET_ESP_MODULE) || defined(CONFIG_INET6_ESP) || defined(CONFIG_INET6_ESP_MODULE) | |
21 | #include <net/esp.h> | |
22 | #endif | |
23 | #include <asm/scatterlist.h> | |
24 | ||
25 | /* | |
26 | * Algorithms supported by IPsec. These entries contain properties which | |
27 | * are used in key negotiation and xfrm processing, and are used to verify | |
28 | * that instantiated crypto transforms have correct parameters for IPsec | |
29 | * purposes. | |
30 | */ | |
31 | static struct xfrm_algo_desc aalg_list[] = { | |
32 | { | |
33 | .name = "digest_null", | |
34 | ||
35 | .uinfo = { | |
36 | .auth = { | |
37 | .icv_truncbits = 0, | |
38 | .icv_fullbits = 0, | |
39 | } | |
40 | }, | |
41 | ||
42 | .desc = { | |
43 | .sadb_alg_id = SADB_X_AALG_NULL, | |
44 | .sadb_alg_ivlen = 0, | |
45 | .sadb_alg_minbits = 0, | |
46 | .sadb_alg_maxbits = 0 | |
47 | } | |
48 | }, | |
49 | { | |
50 | .name = "md5", | |
51 | ||
52 | .uinfo = { | |
53 | .auth = { | |
54 | .icv_truncbits = 96, | |
55 | .icv_fullbits = 128, | |
56 | } | |
57 | }, | |
58 | ||
59 | .desc = { | |
60 | .sadb_alg_id = SADB_AALG_MD5HMAC, | |
61 | .sadb_alg_ivlen = 0, | |
62 | .sadb_alg_minbits = 128, | |
63 | .sadb_alg_maxbits = 128 | |
64 | } | |
65 | }, | |
66 | { | |
67 | .name = "sha1", | |
68 | ||
69 | .uinfo = { | |
70 | .auth = { | |
71 | .icv_truncbits = 96, | |
72 | .icv_fullbits = 160, | |
73 | } | |
74 | }, | |
75 | ||
76 | .desc = { | |
77 | .sadb_alg_id = SADB_AALG_SHA1HMAC, | |
78 | .sadb_alg_ivlen = 0, | |
79 | .sadb_alg_minbits = 160, | |
80 | .sadb_alg_maxbits = 160 | |
81 | } | |
82 | }, | |
83 | { | |
84 | .name = "sha256", | |
85 | ||
86 | .uinfo = { | |
87 | .auth = { | |
88 | .icv_truncbits = 96, | |
89 | .icv_fullbits = 256, | |
90 | } | |
91 | }, | |
92 | ||
93 | .desc = { | |
94 | .sadb_alg_id = SADB_X_AALG_SHA2_256HMAC, | |
95 | .sadb_alg_ivlen = 0, | |
96 | .sadb_alg_minbits = 256, | |
97 | .sadb_alg_maxbits = 256 | |
98 | } | |
99 | }, | |
100 | { | |
101 | .name = "ripemd160", | |
102 | ||
103 | .uinfo = { | |
104 | .auth = { | |
105 | .icv_truncbits = 96, | |
106 | .icv_fullbits = 160, | |
107 | } | |
108 | }, | |
109 | ||
110 | .desc = { | |
111 | .sadb_alg_id = SADB_X_AALG_RIPEMD160HMAC, | |
112 | .sadb_alg_ivlen = 0, | |
113 | .sadb_alg_minbits = 160, | |
114 | .sadb_alg_maxbits = 160 | |
115 | } | |
116 | }, | |
117 | }; | |
118 | ||
119 | static struct xfrm_algo_desc ealg_list[] = { | |
120 | { | |
121 | .name = "cipher_null", | |
122 | ||
123 | .uinfo = { | |
124 | .encr = { | |
125 | .blockbits = 8, | |
126 | .defkeybits = 0, | |
127 | } | |
128 | }, | |
129 | ||
130 | .desc = { | |
131 | .sadb_alg_id = SADB_EALG_NULL, | |
132 | .sadb_alg_ivlen = 0, | |
133 | .sadb_alg_minbits = 0, | |
134 | .sadb_alg_maxbits = 0 | |
135 | } | |
136 | }, | |
137 | { | |
138 | .name = "des", | |
139 | ||
140 | .uinfo = { | |
141 | .encr = { | |
142 | .blockbits = 64, | |
143 | .defkeybits = 64, | |
144 | } | |
145 | }, | |
146 | ||
147 | .desc = { | |
148 | .sadb_alg_id = SADB_EALG_DESCBC, | |
149 | .sadb_alg_ivlen = 8, | |
150 | .sadb_alg_minbits = 64, | |
151 | .sadb_alg_maxbits = 64 | |
152 | } | |
153 | }, | |
154 | { | |
155 | .name = "des3_ede", | |
156 | ||
157 | .uinfo = { | |
158 | .encr = { | |
159 | .blockbits = 64, | |
160 | .defkeybits = 192, | |
161 | } | |
162 | }, | |
163 | ||
164 | .desc = { | |
165 | .sadb_alg_id = SADB_EALG_3DESCBC, | |
166 | .sadb_alg_ivlen = 8, | |
167 | .sadb_alg_minbits = 192, | |
168 | .sadb_alg_maxbits = 192 | |
169 | } | |
170 | }, | |
171 | { | |
172 | .name = "cast128", | |
173 | ||
174 | .uinfo = { | |
175 | .encr = { | |
176 | .blockbits = 64, | |
177 | .defkeybits = 128, | |
178 | } | |
179 | }, | |
180 | ||
181 | .desc = { | |
182 | .sadb_alg_id = SADB_X_EALG_CASTCBC, | |
183 | .sadb_alg_ivlen = 8, | |
184 | .sadb_alg_minbits = 40, | |
185 | .sadb_alg_maxbits = 128 | |
186 | } | |
187 | }, | |
188 | { | |
189 | .name = "blowfish", | |
190 | ||
191 | .uinfo = { | |
192 | .encr = { | |
193 | .blockbits = 64, | |
194 | .defkeybits = 128, | |
195 | } | |
196 | }, | |
197 | ||
198 | .desc = { | |
199 | .sadb_alg_id = SADB_X_EALG_BLOWFISHCBC, | |
200 | .sadb_alg_ivlen = 8, | |
201 | .sadb_alg_minbits = 40, | |
202 | .sadb_alg_maxbits = 448 | |
203 | } | |
204 | }, | |
205 | { | |
206 | .name = "aes", | |
207 | ||
208 | .uinfo = { | |
209 | .encr = { | |
210 | .blockbits = 128, | |
211 | .defkeybits = 128, | |
212 | } | |
213 | }, | |
214 | ||
215 | .desc = { | |
216 | .sadb_alg_id = SADB_X_EALG_AESCBC, | |
217 | .sadb_alg_ivlen = 8, | |
218 | .sadb_alg_minbits = 128, | |
219 | .sadb_alg_maxbits = 256 | |
220 | } | |
221 | }, | |
222 | { | |
223 | .name = "serpent", | |
224 | ||
225 | .uinfo = { | |
226 | .encr = { | |
227 | .blockbits = 128, | |
228 | .defkeybits = 128, | |
229 | } | |
230 | }, | |
231 | ||
232 | .desc = { | |
233 | .sadb_alg_id = SADB_X_EALG_SERPENTCBC, | |
234 | .sadb_alg_ivlen = 8, | |
235 | .sadb_alg_minbits = 128, | |
236 | .sadb_alg_maxbits = 256, | |
237 | } | |
238 | }, | |
239 | { | |
240 | .name = "twofish", | |
241 | ||
242 | .uinfo = { | |
243 | .encr = { | |
244 | .blockbits = 128, | |
245 | .defkeybits = 128, | |
246 | } | |
247 | }, | |
248 | ||
249 | .desc = { | |
250 | .sadb_alg_id = SADB_X_EALG_TWOFISHCBC, | |
251 | .sadb_alg_ivlen = 8, | |
252 | .sadb_alg_minbits = 128, | |
253 | .sadb_alg_maxbits = 256 | |
254 | } | |
255 | }, | |
256 | }; | |
257 | ||
258 | static struct xfrm_algo_desc calg_list[] = { | |
259 | { | |
260 | .name = "deflate", | |
261 | .uinfo = { | |
262 | .comp = { | |
263 | .threshold = 90, | |
264 | } | |
265 | }, | |
266 | .desc = { .sadb_alg_id = SADB_X_CALG_DEFLATE } | |
267 | }, | |
268 | { | |
269 | .name = "lzs", | |
270 | .uinfo = { | |
271 | .comp = { | |
272 | .threshold = 90, | |
273 | } | |
274 | }, | |
275 | .desc = { .sadb_alg_id = SADB_X_CALG_LZS } | |
276 | }, | |
277 | { | |
278 | .name = "lzjh", | |
279 | .uinfo = { | |
280 | .comp = { | |
281 | .threshold = 50, | |
282 | } | |
283 | }, | |
284 | .desc = { .sadb_alg_id = SADB_X_CALG_LZJH } | |
285 | }, | |
286 | }; | |
287 | ||
288 | static inline int aalg_entries(void) | |
289 | { | |
290 | return ARRAY_SIZE(aalg_list); | |
291 | } | |
292 | ||
293 | static inline int ealg_entries(void) | |
294 | { | |
295 | return ARRAY_SIZE(ealg_list); | |
296 | } | |
297 | ||
298 | static inline int calg_entries(void) | |
299 | { | |
300 | return ARRAY_SIZE(calg_list); | |
301 | } | |
302 | ||
303 | /* Todo: generic iterators */ | |
304 | struct xfrm_algo_desc *xfrm_aalg_get_byid(int alg_id) | |
305 | { | |
306 | int i; | |
307 | ||
308 | for (i = 0; i < aalg_entries(); i++) { | |
309 | if (aalg_list[i].desc.sadb_alg_id == alg_id) { | |
310 | if (aalg_list[i].available) | |
311 | return &aalg_list[i]; | |
312 | else | |
313 | break; | |
314 | } | |
315 | } | |
316 | return NULL; | |
317 | } | |
318 | EXPORT_SYMBOL_GPL(xfrm_aalg_get_byid); | |
319 | ||
320 | struct xfrm_algo_desc *xfrm_ealg_get_byid(int alg_id) | |
321 | { | |
322 | int i; | |
323 | ||
324 | for (i = 0; i < ealg_entries(); i++) { | |
325 | if (ealg_list[i].desc.sadb_alg_id == alg_id) { | |
326 | if (ealg_list[i].available) | |
327 | return &ealg_list[i]; | |
328 | else | |
329 | break; | |
330 | } | |
331 | } | |
332 | return NULL; | |
333 | } | |
334 | EXPORT_SYMBOL_GPL(xfrm_ealg_get_byid); | |
335 | ||
336 | struct xfrm_algo_desc *xfrm_calg_get_byid(int alg_id) | |
337 | { | |
338 | int i; | |
339 | ||
340 | for (i = 0; i < calg_entries(); i++) { | |
341 | if (calg_list[i].desc.sadb_alg_id == alg_id) { | |
342 | if (calg_list[i].available) | |
343 | return &calg_list[i]; | |
344 | else | |
345 | break; | |
346 | } | |
347 | } | |
348 | return NULL; | |
349 | } | |
350 | EXPORT_SYMBOL_GPL(xfrm_calg_get_byid); | |
351 | ||
352 | static struct xfrm_algo_desc *xfrm_get_byname(struct xfrm_algo_desc *list, | |
353 | int entries, char *name, | |
354 | int probe) | |
355 | { | |
356 | int i, status; | |
357 | ||
358 | if (!name) | |
359 | return NULL; | |
360 | ||
361 | for (i = 0; i < entries; i++) { | |
04ff1260 HX |
362 | if (strcmp(name, list[i].name) && |
363 | (!list[i].compat || strcmp(name, list[i].compat))) | |
1da177e4 LT |
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 | } | |
09a62660 | 543 | BUG_ON(len); |
1da177e4 LT |
544 | } |
545 | EXPORT_SYMBOL_GPL(skb_icv_walk); | |
546 | ||
547 | #if defined(CONFIG_INET_ESP) || defined(CONFIG_INET_ESP_MODULE) || defined(CONFIG_INET6_ESP) || defined(CONFIG_INET6_ESP_MODULE) | |
548 | ||
549 | /* Looking generic it is not used in another places. */ | |
550 | ||
551 | int | |
552 | skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) | |
553 | { | |
554 | int start = skb_headlen(skb); | |
555 | int i, copy = start - offset; | |
556 | int elt = 0; | |
557 | ||
558 | if (copy > 0) { | |
559 | if (copy > len) | |
560 | copy = len; | |
561 | sg[elt].page = virt_to_page(skb->data + offset); | |
562 | sg[elt].offset = (unsigned long)(skb->data + offset) % PAGE_SIZE; | |
563 | sg[elt].length = copy; | |
564 | elt++; | |
565 | if ((len -= copy) == 0) | |
566 | return elt; | |
567 | offset += copy; | |
568 | } | |
569 | ||
570 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { | |
571 | int end; | |
572 | ||
573 | BUG_TRAP(start <= offset + len); | |
574 | ||
575 | end = start + skb_shinfo(skb)->frags[i].size; | |
576 | if ((copy = end - offset) > 0) { | |
577 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
578 | ||
579 | if (copy > len) | |
580 | copy = len; | |
581 | sg[elt].page = frag->page; | |
582 | sg[elt].offset = frag->page_offset+offset-start; | |
583 | sg[elt].length = copy; | |
584 | elt++; | |
585 | if (!(len -= copy)) | |
586 | return elt; | |
587 | offset += copy; | |
588 | } | |
589 | start = end; | |
590 | } | |
591 | ||
592 | if (skb_shinfo(skb)->frag_list) { | |
593 | struct sk_buff *list = skb_shinfo(skb)->frag_list; | |
594 | ||
595 | for (; list; list = list->next) { | |
596 | int end; | |
597 | ||
598 | BUG_TRAP(start <= offset + len); | |
599 | ||
600 | end = start + list->len; | |
601 | if ((copy = end - offset) > 0) { | |
602 | if (copy > len) | |
603 | copy = len; | |
604 | elt += skb_to_sgvec(list, sg+elt, offset - start, copy); | |
605 | if ((len -= copy) == 0) | |
606 | return elt; | |
607 | offset += copy; | |
608 | } | |
609 | start = end; | |
610 | } | |
611 | } | |
09a62660 | 612 | BUG_ON(len); |
1da177e4 LT |
613 | return elt; |
614 | } | |
615 | EXPORT_SYMBOL_GPL(skb_to_sgvec); | |
616 | ||
617 | /* Check that skb data bits are writable. If they are not, copy data | |
618 | * to newly created private area. If "tailbits" is given, make sure that | |
619 | * tailbits bytes beyond current end of skb are writable. | |
620 | * | |
621 | * Returns amount of elements of scatterlist to load for subsequent | |
622 | * transformations and pointer to writable trailer skb. | |
623 | */ | |
624 | ||
625 | int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer) | |
626 | { | |
627 | int copyflag; | |
628 | int elt; | |
629 | struct sk_buff *skb1, **skb_p; | |
630 | ||
631 | /* If skb is cloned or its head is paged, reallocate | |
632 | * head pulling out all the pages (pages are considered not writable | |
633 | * at the moment even if they are anonymous). | |
634 | */ | |
635 | if ((skb_cloned(skb) || skb_shinfo(skb)->nr_frags) && | |
636 | __pskb_pull_tail(skb, skb_pagelen(skb)-skb_headlen(skb)) == NULL) | |
637 | return -ENOMEM; | |
638 | ||
639 | /* Easy case. Most of packets will go this way. */ | |
640 | if (!skb_shinfo(skb)->frag_list) { | |
641 | /* A little of trouble, not enough of space for trailer. | |
642 | * This should not happen, when stack is tuned to generate | |
643 | * good frames. OK, on miss we reallocate and reserve even more | |
644 | * space, 128 bytes is fair. */ | |
645 | ||
646 | if (skb_tailroom(skb) < tailbits && | |
647 | pskb_expand_head(skb, 0, tailbits-skb_tailroom(skb)+128, GFP_ATOMIC)) | |
648 | return -ENOMEM; | |
649 | ||
650 | /* Voila! */ | |
651 | *trailer = skb; | |
652 | return 1; | |
653 | } | |
654 | ||
655 | /* Misery. We are in troubles, going to mincer fragments... */ | |
656 | ||
657 | elt = 1; | |
658 | skb_p = &skb_shinfo(skb)->frag_list; | |
659 | copyflag = 0; | |
660 | ||
661 | while ((skb1 = *skb_p) != NULL) { | |
662 | int ntail = 0; | |
663 | ||
664 | /* The fragment is partially pulled by someone, | |
665 | * this can happen on input. Copy it and everything | |
666 | * after it. */ | |
667 | ||
668 | if (skb_shared(skb1)) | |
669 | copyflag = 1; | |
670 | ||
671 | /* If the skb is the last, worry about trailer. */ | |
672 | ||
673 | if (skb1->next == NULL && tailbits) { | |
674 | if (skb_shinfo(skb1)->nr_frags || | |
675 | skb_shinfo(skb1)->frag_list || | |
676 | skb_tailroom(skb1) < tailbits) | |
677 | ntail = tailbits + 128; | |
678 | } | |
679 | ||
680 | if (copyflag || | |
681 | skb_cloned(skb1) || | |
682 | ntail || | |
683 | skb_shinfo(skb1)->nr_frags || | |
684 | skb_shinfo(skb1)->frag_list) { | |
685 | struct sk_buff *skb2; | |
686 | ||
687 | /* Fuck, we are miserable poor guys... */ | |
688 | if (ntail == 0) | |
689 | skb2 = skb_copy(skb1, GFP_ATOMIC); | |
690 | else | |
691 | skb2 = skb_copy_expand(skb1, | |
692 | skb_headroom(skb1), | |
693 | ntail, | |
694 | GFP_ATOMIC); | |
695 | if (unlikely(skb2 == NULL)) | |
696 | return -ENOMEM; | |
697 | ||
698 | if (skb1->sk) | |
d4810200 | 699 | skb_set_owner_w(skb2, skb1->sk); |
1da177e4 LT |
700 | |
701 | /* Looking around. Are we still alive? | |
702 | * OK, link new skb, drop old one */ | |
703 | ||
704 | skb2->next = skb1->next; | |
705 | *skb_p = skb2; | |
706 | kfree_skb(skb1); | |
707 | skb1 = skb2; | |
708 | } | |
709 | elt++; | |
710 | *trailer = skb1; | |
711 | skb_p = &skb1->next; | |
712 | } | |
713 | ||
714 | return elt; | |
715 | } | |
716 | EXPORT_SYMBOL_GPL(skb_cow_data); | |
717 | ||
718 | void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len) | |
719 | { | |
720 | if (tail != skb) { | |
721 | skb->data_len += len; | |
722 | skb->len += len; | |
723 | } | |
724 | return skb_put(tail, len); | |
725 | } | |
726 | EXPORT_SYMBOL_GPL(pskb_put); | |
727 | #endif |