diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/xfrm/xfrm_algo.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'net/xfrm/xfrm_algo.c')
-rw-r--r-- | net/xfrm/xfrm_algo.c | 729 |
1 files changed, 729 insertions, 0 deletions
diff --git a/net/xfrm/xfrm_algo.c b/net/xfrm/xfrm_algo.c new file mode 100644 index 000000000000..080aae243ce0 --- /dev/null +++ b/net/xfrm/xfrm_algo.c | |||
@@ -0,0 +1,729 @@ | |||
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) | ||
701 | skb_set_owner_w(skb, skb1->sk); | ||
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 | ||