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 | { | |
07d4ee58 HX |
33 | .name = "hmac(digest_null)", |
34 | .compat = "digest_null", | |
1da177e4 LT |
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 | { | |
07d4ee58 HX |
51 | .name = "hmac(md5)", |
52 | .compat = "md5", | |
1da177e4 LT |
53 | |
54 | .uinfo = { | |
55 | .auth = { | |
56 | .icv_truncbits = 96, | |
57 | .icv_fullbits = 128, | |
58 | } | |
59 | }, | |
60 | ||
61 | .desc = { | |
62 | .sadb_alg_id = SADB_AALG_MD5HMAC, | |
63 | .sadb_alg_ivlen = 0, | |
64 | .sadb_alg_minbits = 128, | |
65 | .sadb_alg_maxbits = 128 | |
66 | } | |
67 | }, | |
68 | { | |
07d4ee58 HX |
69 | .name = "hmac(sha1)", |
70 | .compat = "sha1", | |
1da177e4 LT |
71 | |
72 | .uinfo = { | |
73 | .auth = { | |
74 | .icv_truncbits = 96, | |
75 | .icv_fullbits = 160, | |
76 | } | |
77 | }, | |
78 | ||
79 | .desc = { | |
80 | .sadb_alg_id = SADB_AALG_SHA1HMAC, | |
81 | .sadb_alg_ivlen = 0, | |
82 | .sadb_alg_minbits = 160, | |
83 | .sadb_alg_maxbits = 160 | |
84 | } | |
85 | }, | |
86 | { | |
07d4ee58 HX |
87 | .name = "hmac(sha256)", |
88 | .compat = "sha256", | |
1da177e4 LT |
89 | |
90 | .uinfo = { | |
91 | .auth = { | |
92 | .icv_truncbits = 96, | |
93 | .icv_fullbits = 256, | |
94 | } | |
95 | }, | |
96 | ||
97 | .desc = { | |
98 | .sadb_alg_id = SADB_X_AALG_SHA2_256HMAC, | |
99 | .sadb_alg_ivlen = 0, | |
100 | .sadb_alg_minbits = 256, | |
101 | .sadb_alg_maxbits = 256 | |
102 | } | |
103 | }, | |
104 | { | |
07d4ee58 HX |
105 | .name = "hmac(ripemd160)", |
106 | .compat = "ripemd160", | |
1da177e4 LT |
107 | |
108 | .uinfo = { | |
109 | .auth = { | |
110 | .icv_truncbits = 96, | |
111 | .icv_fullbits = 160, | |
112 | } | |
113 | }, | |
114 | ||
115 | .desc = { | |
116 | .sadb_alg_id = SADB_X_AALG_RIPEMD160HMAC, | |
117 | .sadb_alg_ivlen = 0, | |
118 | .sadb_alg_minbits = 160, | |
119 | .sadb_alg_maxbits = 160 | |
120 | } | |
121 | }, | |
122 | }; | |
123 | ||
124 | static struct xfrm_algo_desc ealg_list[] = { | |
125 | { | |
6b7326c8 HX |
126 | .name = "ecb(cipher_null)", |
127 | .compat = "cipher_null", | |
1da177e4 LT |
128 | |
129 | .uinfo = { | |
130 | .encr = { | |
131 | .blockbits = 8, | |
132 | .defkeybits = 0, | |
133 | } | |
134 | }, | |
135 | ||
136 | .desc = { | |
137 | .sadb_alg_id = SADB_EALG_NULL, | |
138 | .sadb_alg_ivlen = 0, | |
139 | .sadb_alg_minbits = 0, | |
140 | .sadb_alg_maxbits = 0 | |
141 | } | |
142 | }, | |
143 | { | |
6b7326c8 HX |
144 | .name = "cbc(des)", |
145 | .compat = "des", | |
1da177e4 LT |
146 | |
147 | .uinfo = { | |
148 | .encr = { | |
149 | .blockbits = 64, | |
150 | .defkeybits = 64, | |
151 | } | |
152 | }, | |
153 | ||
154 | .desc = { | |
155 | .sadb_alg_id = SADB_EALG_DESCBC, | |
156 | .sadb_alg_ivlen = 8, | |
157 | .sadb_alg_minbits = 64, | |
158 | .sadb_alg_maxbits = 64 | |
159 | } | |
160 | }, | |
161 | { | |
6b7326c8 HX |
162 | .name = "cbc(des3_ede)", |
163 | .compat = "des3_ede", | |
1da177e4 LT |
164 | |
165 | .uinfo = { | |
166 | .encr = { | |
167 | .blockbits = 64, | |
168 | .defkeybits = 192, | |
169 | } | |
170 | }, | |
171 | ||
172 | .desc = { | |
173 | .sadb_alg_id = SADB_EALG_3DESCBC, | |
174 | .sadb_alg_ivlen = 8, | |
175 | .sadb_alg_minbits = 192, | |
176 | .sadb_alg_maxbits = 192 | |
177 | } | |
178 | }, | |
179 | { | |
6b7326c8 HX |
180 | .name = "cbc(cast128)", |
181 | .compat = "cast128", | |
1da177e4 LT |
182 | |
183 | .uinfo = { | |
184 | .encr = { | |
185 | .blockbits = 64, | |
186 | .defkeybits = 128, | |
187 | } | |
188 | }, | |
189 | ||
190 | .desc = { | |
191 | .sadb_alg_id = SADB_X_EALG_CASTCBC, | |
192 | .sadb_alg_ivlen = 8, | |
193 | .sadb_alg_minbits = 40, | |
194 | .sadb_alg_maxbits = 128 | |
195 | } | |
196 | }, | |
197 | { | |
6b7326c8 HX |
198 | .name = "cbc(blowfish)", |
199 | .compat = "blowfish", | |
1da177e4 LT |
200 | |
201 | .uinfo = { | |
202 | .encr = { | |
203 | .blockbits = 64, | |
204 | .defkeybits = 128, | |
205 | } | |
206 | }, | |
207 | ||
208 | .desc = { | |
209 | .sadb_alg_id = SADB_X_EALG_BLOWFISHCBC, | |
210 | .sadb_alg_ivlen = 8, | |
211 | .sadb_alg_minbits = 40, | |
212 | .sadb_alg_maxbits = 448 | |
213 | } | |
214 | }, | |
215 | { | |
6b7326c8 HX |
216 | .name = "cbc(aes)", |
217 | .compat = "aes", | |
1da177e4 LT |
218 | |
219 | .uinfo = { | |
220 | .encr = { | |
221 | .blockbits = 128, | |
222 | .defkeybits = 128, | |
223 | } | |
224 | }, | |
225 | ||
226 | .desc = { | |
227 | .sadb_alg_id = SADB_X_EALG_AESCBC, | |
228 | .sadb_alg_ivlen = 8, | |
229 | .sadb_alg_minbits = 128, | |
230 | .sadb_alg_maxbits = 256 | |
231 | } | |
232 | }, | |
233 | { | |
6b7326c8 HX |
234 | .name = "cbc(serpent)", |
235 | .compat = "serpent", | |
1da177e4 LT |
236 | |
237 | .uinfo = { | |
238 | .encr = { | |
239 | .blockbits = 128, | |
240 | .defkeybits = 128, | |
241 | } | |
242 | }, | |
243 | ||
244 | .desc = { | |
245 | .sadb_alg_id = SADB_X_EALG_SERPENTCBC, | |
246 | .sadb_alg_ivlen = 8, | |
247 | .sadb_alg_minbits = 128, | |
248 | .sadb_alg_maxbits = 256, | |
249 | } | |
250 | }, | |
251 | { | |
6b7326c8 HX |
252 | .name = "cbc(twofish)", |
253 | .compat = "twofish", | |
1da177e4 LT |
254 | |
255 | .uinfo = { | |
256 | .encr = { | |
257 | .blockbits = 128, | |
258 | .defkeybits = 128, | |
259 | } | |
260 | }, | |
261 | ||
262 | .desc = { | |
263 | .sadb_alg_id = SADB_X_EALG_TWOFISHCBC, | |
264 | .sadb_alg_ivlen = 8, | |
265 | .sadb_alg_minbits = 128, | |
266 | .sadb_alg_maxbits = 256 | |
267 | } | |
268 | }, | |
269 | }; | |
270 | ||
271 | static struct xfrm_algo_desc calg_list[] = { | |
272 | { | |
273 | .name = "deflate", | |
274 | .uinfo = { | |
275 | .comp = { | |
276 | .threshold = 90, | |
277 | } | |
278 | }, | |
279 | .desc = { .sadb_alg_id = SADB_X_CALG_DEFLATE } | |
280 | }, | |
281 | { | |
282 | .name = "lzs", | |
283 | .uinfo = { | |
284 | .comp = { | |
285 | .threshold = 90, | |
286 | } | |
287 | }, | |
288 | .desc = { .sadb_alg_id = SADB_X_CALG_LZS } | |
289 | }, | |
290 | { | |
291 | .name = "lzjh", | |
292 | .uinfo = { | |
293 | .comp = { | |
294 | .threshold = 50, | |
295 | } | |
296 | }, | |
297 | .desc = { .sadb_alg_id = SADB_X_CALG_LZJH } | |
298 | }, | |
299 | }; | |
300 | ||
301 | static inline int aalg_entries(void) | |
302 | { | |
303 | return ARRAY_SIZE(aalg_list); | |
304 | } | |
305 | ||
306 | static inline int ealg_entries(void) | |
307 | { | |
308 | return ARRAY_SIZE(ealg_list); | |
309 | } | |
310 | ||
311 | static inline int calg_entries(void) | |
312 | { | |
313 | return ARRAY_SIZE(calg_list); | |
314 | } | |
315 | ||
316 | /* Todo: generic iterators */ | |
317 | struct xfrm_algo_desc *xfrm_aalg_get_byid(int alg_id) | |
318 | { | |
319 | int i; | |
320 | ||
321 | for (i = 0; i < aalg_entries(); i++) { | |
322 | if (aalg_list[i].desc.sadb_alg_id == alg_id) { | |
323 | if (aalg_list[i].available) | |
324 | return &aalg_list[i]; | |
325 | else | |
326 | break; | |
327 | } | |
328 | } | |
329 | return NULL; | |
330 | } | |
331 | EXPORT_SYMBOL_GPL(xfrm_aalg_get_byid); | |
332 | ||
333 | struct xfrm_algo_desc *xfrm_ealg_get_byid(int alg_id) | |
334 | { | |
335 | int i; | |
336 | ||
337 | for (i = 0; i < ealg_entries(); i++) { | |
338 | if (ealg_list[i].desc.sadb_alg_id == alg_id) { | |
339 | if (ealg_list[i].available) | |
340 | return &ealg_list[i]; | |
341 | else | |
342 | break; | |
343 | } | |
344 | } | |
345 | return NULL; | |
346 | } | |
347 | EXPORT_SYMBOL_GPL(xfrm_ealg_get_byid); | |
348 | ||
349 | struct xfrm_algo_desc *xfrm_calg_get_byid(int alg_id) | |
350 | { | |
351 | int i; | |
352 | ||
353 | for (i = 0; i < calg_entries(); i++) { | |
354 | if (calg_list[i].desc.sadb_alg_id == alg_id) { | |
355 | if (calg_list[i].available) | |
356 | return &calg_list[i]; | |
357 | else | |
358 | break; | |
359 | } | |
360 | } | |
361 | return NULL; | |
362 | } | |
363 | EXPORT_SYMBOL_GPL(xfrm_calg_get_byid); | |
364 | ||
365 | static struct xfrm_algo_desc *xfrm_get_byname(struct xfrm_algo_desc *list, | |
e4d5b79c HX |
366 | int entries, u32 type, u32 mask, |
367 | char *name, int probe) | |
1da177e4 LT |
368 | { |
369 | int i, status; | |
370 | ||
371 | if (!name) | |
372 | return NULL; | |
373 | ||
374 | for (i = 0; i < entries; i++) { | |
04ff1260 HX |
375 | if (strcmp(name, list[i].name) && |
376 | (!list[i].compat || strcmp(name, list[i].compat))) | |
1da177e4 LT |
377 | continue; |
378 | ||
379 | if (list[i].available) | |
380 | return &list[i]; | |
381 | ||
382 | if (!probe) | |
383 | break; | |
384 | ||
e4d5b79c | 385 | status = crypto_has_alg(name, type, mask | CRYPTO_ALG_ASYNC); |
1da177e4 LT |
386 | if (!status) |
387 | break; | |
388 | ||
389 | list[i].available = status; | |
390 | return &list[i]; | |
391 | } | |
392 | return NULL; | |
393 | } | |
394 | ||
395 | struct xfrm_algo_desc *xfrm_aalg_get_byname(char *name, int probe) | |
396 | { | |
e4d5b79c HX |
397 | return xfrm_get_byname(aalg_list, aalg_entries(), |
398 | CRYPTO_ALG_TYPE_HASH, CRYPTO_ALG_TYPE_HASH_MASK, | |
399 | name, probe); | |
1da177e4 LT |
400 | } |
401 | EXPORT_SYMBOL_GPL(xfrm_aalg_get_byname); | |
402 | ||
403 | struct xfrm_algo_desc *xfrm_ealg_get_byname(char *name, int probe) | |
404 | { | |
e4d5b79c HX |
405 | return xfrm_get_byname(ealg_list, ealg_entries(), |
406 | CRYPTO_ALG_TYPE_BLKCIPHER, CRYPTO_ALG_TYPE_MASK, | |
407 | name, probe); | |
1da177e4 LT |
408 | } |
409 | EXPORT_SYMBOL_GPL(xfrm_ealg_get_byname); | |
410 | ||
411 | struct xfrm_algo_desc *xfrm_calg_get_byname(char *name, int probe) | |
412 | { | |
e4d5b79c HX |
413 | return xfrm_get_byname(calg_list, calg_entries(), |
414 | CRYPTO_ALG_TYPE_COMPRESS, CRYPTO_ALG_TYPE_MASK, | |
415 | name, probe); | |
1da177e4 LT |
416 | } |
417 | EXPORT_SYMBOL_GPL(xfrm_calg_get_byname); | |
418 | ||
419 | struct xfrm_algo_desc *xfrm_aalg_get_byidx(unsigned int idx) | |
420 | { | |
421 | if (idx >= aalg_entries()) | |
422 | return NULL; | |
423 | ||
424 | return &aalg_list[idx]; | |
425 | } | |
426 | EXPORT_SYMBOL_GPL(xfrm_aalg_get_byidx); | |
427 | ||
428 | struct xfrm_algo_desc *xfrm_ealg_get_byidx(unsigned int idx) | |
429 | { | |
430 | if (idx >= ealg_entries()) | |
431 | return NULL; | |
432 | ||
433 | return &ealg_list[idx]; | |
434 | } | |
435 | EXPORT_SYMBOL_GPL(xfrm_ealg_get_byidx); | |
436 | ||
437 | /* | |
438 | * Probe for the availability of crypto algorithms, and set the available | |
439 | * flag for any algorithms found on the system. This is typically called by | |
440 | * pfkey during userspace SA add, update or register. | |
441 | */ | |
442 | void xfrm_probe_algs(void) | |
443 | { | |
444 | #ifdef CONFIG_CRYPTO | |
445 | int i, status; | |
446 | ||
447 | BUG_ON(in_softirq()); | |
448 | ||
449 | for (i = 0; i < aalg_entries(); i++) { | |
e4d5b79c HX |
450 | status = crypto_has_hash(aalg_list[i].name, 0, |
451 | CRYPTO_ALG_ASYNC); | |
1da177e4 LT |
452 | if (aalg_list[i].available != status) |
453 | aalg_list[i].available = status; | |
454 | } | |
455 | ||
456 | for (i = 0; i < ealg_entries(); i++) { | |
e4d5b79c HX |
457 | status = crypto_has_blkcipher(ealg_list[i].name, 0, |
458 | CRYPTO_ALG_ASYNC); | |
1da177e4 LT |
459 | if (ealg_list[i].available != status) |
460 | ealg_list[i].available = status; | |
461 | } | |
462 | ||
463 | for (i = 0; i < calg_entries(); i++) { | |
e4d5b79c HX |
464 | status = crypto_has_comp(calg_list[i].name, 0, |
465 | CRYPTO_ALG_ASYNC); | |
1da177e4 LT |
466 | if (calg_list[i].available != status) |
467 | calg_list[i].available = status; | |
468 | } | |
469 | #endif | |
470 | } | |
471 | EXPORT_SYMBOL_GPL(xfrm_probe_algs); | |
472 | ||
473 | int xfrm_count_auth_supported(void) | |
474 | { | |
475 | int i, n; | |
476 | ||
477 | for (i = 0, n = 0; i < aalg_entries(); i++) | |
478 | if (aalg_list[i].available) | |
479 | n++; | |
480 | return n; | |
481 | } | |
482 | EXPORT_SYMBOL_GPL(xfrm_count_auth_supported); | |
483 | ||
484 | int xfrm_count_enc_supported(void) | |
485 | { | |
486 | int i, n; | |
487 | ||
488 | for (i = 0, n = 0; i < ealg_entries(); i++) | |
489 | if (ealg_list[i].available) | |
490 | n++; | |
491 | return n; | |
492 | } | |
493 | EXPORT_SYMBOL_GPL(xfrm_count_enc_supported); | |
494 | ||
495 | /* Move to common area: it is shared with AH. */ | |
496 | ||
07d4ee58 HX |
497 | int skb_icv_walk(const struct sk_buff *skb, struct hash_desc *desc, |
498 | int offset, int len, icv_update_fn_t icv_update) | |
1da177e4 LT |
499 | { |
500 | int start = skb_headlen(skb); | |
501 | int i, copy = start - offset; | |
07d4ee58 | 502 | int err; |
1da177e4 LT |
503 | struct scatterlist sg; |
504 | ||
505 | /* Checksum header. */ | |
506 | if (copy > 0) { | |
507 | if (copy > len) | |
508 | copy = len; | |
509 | ||
510 | sg.page = virt_to_page(skb->data + offset); | |
511 | sg.offset = (unsigned long)(skb->data + offset) % PAGE_SIZE; | |
512 | sg.length = copy; | |
513 | ||
07d4ee58 HX |
514 | err = icv_update(desc, &sg, copy); |
515 | if (unlikely(err)) | |
516 | return err; | |
1da177e4 LT |
517 | |
518 | if ((len -= copy) == 0) | |
07d4ee58 | 519 | return 0; |
1da177e4 LT |
520 | offset += copy; |
521 | } | |
522 | ||
523 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { | |
524 | int end; | |
525 | ||
526 | BUG_TRAP(start <= offset + len); | |
527 | ||
528 | end = start + skb_shinfo(skb)->frags[i].size; | |
529 | if ((copy = end - offset) > 0) { | |
530 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
531 | ||
532 | if (copy > len) | |
533 | copy = len; | |
534 | ||
535 | sg.page = frag->page; | |
536 | sg.offset = frag->page_offset + offset-start; | |
537 | sg.length = copy; | |
538 | ||
07d4ee58 HX |
539 | err = icv_update(desc, &sg, copy); |
540 | if (unlikely(err)) | |
541 | return err; | |
1da177e4 LT |
542 | |
543 | if (!(len -= copy)) | |
07d4ee58 | 544 | return 0; |
1da177e4 LT |
545 | offset += copy; |
546 | } | |
547 | start = end; | |
548 | } | |
549 | ||
550 | if (skb_shinfo(skb)->frag_list) { | |
551 | struct sk_buff *list = skb_shinfo(skb)->frag_list; | |
552 | ||
553 | for (; list; list = list->next) { | |
554 | int end; | |
555 | ||
556 | BUG_TRAP(start <= offset + len); | |
557 | ||
558 | end = start + list->len; | |
559 | if ((copy = end - offset) > 0) { | |
560 | if (copy > len) | |
561 | copy = len; | |
07d4ee58 HX |
562 | err = skb_icv_walk(list, desc, offset-start, |
563 | copy, icv_update); | |
564 | if (unlikely(err)) | |
565 | return err; | |
1da177e4 | 566 | if ((len -= copy) == 0) |
07d4ee58 | 567 | return 0; |
1da177e4 LT |
568 | offset += copy; |
569 | } | |
570 | start = end; | |
571 | } | |
572 | } | |
09a62660 | 573 | BUG_ON(len); |
07d4ee58 | 574 | return 0; |
1da177e4 LT |
575 | } |
576 | EXPORT_SYMBOL_GPL(skb_icv_walk); | |
577 | ||
578 | #if defined(CONFIG_INET_ESP) || defined(CONFIG_INET_ESP_MODULE) || defined(CONFIG_INET6_ESP) || defined(CONFIG_INET6_ESP_MODULE) | |
579 | ||
580 | /* Looking generic it is not used in another places. */ | |
581 | ||
582 | int | |
583 | skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) | |
584 | { | |
585 | int start = skb_headlen(skb); | |
586 | int i, copy = start - offset; | |
587 | int elt = 0; | |
588 | ||
589 | if (copy > 0) { | |
590 | if (copy > len) | |
591 | copy = len; | |
592 | sg[elt].page = virt_to_page(skb->data + offset); | |
593 | sg[elt].offset = (unsigned long)(skb->data + offset) % PAGE_SIZE; | |
594 | sg[elt].length = copy; | |
595 | elt++; | |
596 | if ((len -= copy) == 0) | |
597 | return elt; | |
598 | offset += copy; | |
599 | } | |
600 | ||
601 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { | |
602 | int end; | |
603 | ||
604 | BUG_TRAP(start <= offset + len); | |
605 | ||
606 | end = start + skb_shinfo(skb)->frags[i].size; | |
607 | if ((copy = end - offset) > 0) { | |
608 | skb_frag_t *frag = &skb_shinfo(skb)->frags[i]; | |
609 | ||
610 | if (copy > len) | |
611 | copy = len; | |
612 | sg[elt].page = frag->page; | |
613 | sg[elt].offset = frag->page_offset+offset-start; | |
614 | sg[elt].length = copy; | |
615 | elt++; | |
616 | if (!(len -= copy)) | |
617 | return elt; | |
618 | offset += copy; | |
619 | } | |
620 | start = end; | |
621 | } | |
622 | ||
623 | if (skb_shinfo(skb)->frag_list) { | |
624 | struct sk_buff *list = skb_shinfo(skb)->frag_list; | |
625 | ||
626 | for (; list; list = list->next) { | |
627 | int end; | |
628 | ||
629 | BUG_TRAP(start <= offset + len); | |
630 | ||
631 | end = start + list->len; | |
632 | if ((copy = end - offset) > 0) { | |
633 | if (copy > len) | |
634 | copy = len; | |
635 | elt += skb_to_sgvec(list, sg+elt, offset - start, copy); | |
636 | if ((len -= copy) == 0) | |
637 | return elt; | |
638 | offset += copy; | |
639 | } | |
640 | start = end; | |
641 | } | |
642 | } | |
09a62660 | 643 | BUG_ON(len); |
1da177e4 LT |
644 | return elt; |
645 | } | |
646 | EXPORT_SYMBOL_GPL(skb_to_sgvec); | |
647 | ||
648 | /* Check that skb data bits are writable. If they are not, copy data | |
649 | * to newly created private area. If "tailbits" is given, make sure that | |
650 | * tailbits bytes beyond current end of skb are writable. | |
651 | * | |
652 | * Returns amount of elements of scatterlist to load for subsequent | |
653 | * transformations and pointer to writable trailer skb. | |
654 | */ | |
655 | ||
656 | int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer) | |
657 | { | |
658 | int copyflag; | |
659 | int elt; | |
660 | struct sk_buff *skb1, **skb_p; | |
661 | ||
662 | /* If skb is cloned or its head is paged, reallocate | |
663 | * head pulling out all the pages (pages are considered not writable | |
664 | * at the moment even if they are anonymous). | |
665 | */ | |
666 | if ((skb_cloned(skb) || skb_shinfo(skb)->nr_frags) && | |
667 | __pskb_pull_tail(skb, skb_pagelen(skb)-skb_headlen(skb)) == NULL) | |
668 | return -ENOMEM; | |
669 | ||
670 | /* Easy case. Most of packets will go this way. */ | |
671 | if (!skb_shinfo(skb)->frag_list) { | |
672 | /* A little of trouble, not enough of space for trailer. | |
673 | * This should not happen, when stack is tuned to generate | |
674 | * good frames. OK, on miss we reallocate and reserve even more | |
675 | * space, 128 bytes is fair. */ | |
676 | ||
677 | if (skb_tailroom(skb) < tailbits && | |
678 | pskb_expand_head(skb, 0, tailbits-skb_tailroom(skb)+128, GFP_ATOMIC)) | |
679 | return -ENOMEM; | |
680 | ||
681 | /* Voila! */ | |
682 | *trailer = skb; | |
683 | return 1; | |
684 | } | |
685 | ||
686 | /* Misery. We are in troubles, going to mincer fragments... */ | |
687 | ||
688 | elt = 1; | |
689 | skb_p = &skb_shinfo(skb)->frag_list; | |
690 | copyflag = 0; | |
691 | ||
692 | while ((skb1 = *skb_p) != NULL) { | |
693 | int ntail = 0; | |
694 | ||
695 | /* The fragment is partially pulled by someone, | |
696 | * this can happen on input. Copy it and everything | |
697 | * after it. */ | |
698 | ||
699 | if (skb_shared(skb1)) | |
700 | copyflag = 1; | |
701 | ||
702 | /* If the skb is the last, worry about trailer. */ | |
703 | ||
704 | if (skb1->next == NULL && tailbits) { | |
705 | if (skb_shinfo(skb1)->nr_frags || | |
706 | skb_shinfo(skb1)->frag_list || | |
707 | skb_tailroom(skb1) < tailbits) | |
708 | ntail = tailbits + 128; | |
709 | } | |
710 | ||
711 | if (copyflag || | |
712 | skb_cloned(skb1) || | |
713 | ntail || | |
714 | skb_shinfo(skb1)->nr_frags || | |
715 | skb_shinfo(skb1)->frag_list) { | |
716 | struct sk_buff *skb2; | |
717 | ||
718 | /* Fuck, we are miserable poor guys... */ | |
719 | if (ntail == 0) | |
720 | skb2 = skb_copy(skb1, GFP_ATOMIC); | |
721 | else | |
722 | skb2 = skb_copy_expand(skb1, | |
723 | skb_headroom(skb1), | |
724 | ntail, | |
725 | GFP_ATOMIC); | |
726 | if (unlikely(skb2 == NULL)) | |
727 | return -ENOMEM; | |
728 | ||
729 | if (skb1->sk) | |
d4810200 | 730 | skb_set_owner_w(skb2, skb1->sk); |
1da177e4 LT |
731 | |
732 | /* Looking around. Are we still alive? | |
733 | * OK, link new skb, drop old one */ | |
734 | ||
735 | skb2->next = skb1->next; | |
736 | *skb_p = skb2; | |
737 | kfree_skb(skb1); | |
738 | skb1 = skb2; | |
739 | } | |
740 | elt++; | |
741 | *trailer = skb1; | |
742 | skb_p = &skb1->next; | |
743 | } | |
744 | ||
745 | return elt; | |
746 | } | |
747 | EXPORT_SYMBOL_GPL(skb_cow_data); | |
748 | ||
749 | void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len) | |
750 | { | |
751 | if (tail != skb) { | |
752 | skb->data_len += len; | |
753 | skb->len += len; | |
754 | } | |
755 | return skb_put(tail, len); | |
756 | } | |
757 | EXPORT_SYMBOL_GPL(pskb_put); | |
758 | #endif |