Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * xfrm_policy.c | |
3 | * | |
4 | * Changes: | |
5 | * Mitsuru KANDA @USAGI | |
6 | * Kazunori MIYAZAWA @USAGI | |
7 | * Kunihiro Ishiguro <kunihiro@ipinfusion.com> | |
8 | * IPv6 support | |
9 | * Kazunori MIYAZAWA @USAGI | |
10 | * YOSHIFUJI Hideaki | |
11 | * Split up af-specific portion | |
12 | * Derek Atkins <derek@ihtfp.com> Add the post_input processor | |
13 | * | |
14 | */ | |
15 | ||
16 | #include <asm/bug.h> | |
17 | #include <linux/config.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/kmod.h> | |
20 | #include <linux/list.h> | |
21 | #include <linux/spinlock.h> | |
22 | #include <linux/workqueue.h> | |
23 | #include <linux/notifier.h> | |
24 | #include <linux/netdevice.h> | |
25 | #include <linux/module.h> | |
26 | #include <net/xfrm.h> | |
27 | #include <net/ip.h> | |
28 | ||
29 | DECLARE_MUTEX(xfrm_cfg_sem); | |
30 | EXPORT_SYMBOL(xfrm_cfg_sem); | |
31 | ||
32 | static DEFINE_RWLOCK(xfrm_policy_lock); | |
33 | ||
34 | struct xfrm_policy *xfrm_policy_list[XFRM_POLICY_MAX*2]; | |
35 | EXPORT_SYMBOL(xfrm_policy_list); | |
36 | ||
37 | static DEFINE_RWLOCK(xfrm_policy_afinfo_lock); | |
38 | static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO]; | |
39 | ||
40 | static kmem_cache_t *xfrm_dst_cache; | |
41 | ||
42 | static struct work_struct xfrm_policy_gc_work; | |
43 | static struct list_head xfrm_policy_gc_list = | |
44 | LIST_HEAD_INIT(xfrm_policy_gc_list); | |
45 | static DEFINE_SPINLOCK(xfrm_policy_gc_lock); | |
46 | ||
47 | static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family); | |
48 | static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo); | |
49 | ||
50 | int xfrm_register_type(struct xfrm_type *type, unsigned short family) | |
51 | { | |
52 | struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); | |
53 | struct xfrm_type_map *typemap; | |
54 | int err = 0; | |
55 | ||
56 | if (unlikely(afinfo == NULL)) | |
57 | return -EAFNOSUPPORT; | |
58 | typemap = afinfo->type_map; | |
59 | ||
60 | write_lock(&typemap->lock); | |
61 | if (likely(typemap->map[type->proto] == NULL)) | |
62 | typemap->map[type->proto] = type; | |
63 | else | |
64 | err = -EEXIST; | |
65 | write_unlock(&typemap->lock); | |
66 | xfrm_policy_put_afinfo(afinfo); | |
67 | return err; | |
68 | } | |
69 | EXPORT_SYMBOL(xfrm_register_type); | |
70 | ||
71 | int xfrm_unregister_type(struct xfrm_type *type, unsigned short family) | |
72 | { | |
73 | struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); | |
74 | struct xfrm_type_map *typemap; | |
75 | int err = 0; | |
76 | ||
77 | if (unlikely(afinfo == NULL)) | |
78 | return -EAFNOSUPPORT; | |
79 | typemap = afinfo->type_map; | |
80 | ||
81 | write_lock(&typemap->lock); | |
82 | if (unlikely(typemap->map[type->proto] != type)) | |
83 | err = -ENOENT; | |
84 | else | |
85 | typemap->map[type->proto] = NULL; | |
86 | write_unlock(&typemap->lock); | |
87 | xfrm_policy_put_afinfo(afinfo); | |
88 | return err; | |
89 | } | |
90 | EXPORT_SYMBOL(xfrm_unregister_type); | |
91 | ||
92 | struct xfrm_type *xfrm_get_type(u8 proto, unsigned short family) | |
93 | { | |
94 | struct xfrm_policy_afinfo *afinfo; | |
95 | struct xfrm_type_map *typemap; | |
96 | struct xfrm_type *type; | |
97 | int modload_attempted = 0; | |
98 | ||
99 | retry: | |
100 | afinfo = xfrm_policy_get_afinfo(family); | |
101 | if (unlikely(afinfo == NULL)) | |
102 | return NULL; | |
103 | typemap = afinfo->type_map; | |
104 | ||
105 | read_lock(&typemap->lock); | |
106 | type = typemap->map[proto]; | |
107 | if (unlikely(type && !try_module_get(type->owner))) | |
108 | type = NULL; | |
109 | read_unlock(&typemap->lock); | |
110 | if (!type && !modload_attempted) { | |
111 | xfrm_policy_put_afinfo(afinfo); | |
112 | request_module("xfrm-type-%d-%d", | |
113 | (int) family, (int) proto); | |
114 | modload_attempted = 1; | |
115 | goto retry; | |
116 | } | |
117 | ||
118 | xfrm_policy_put_afinfo(afinfo); | |
119 | return type; | |
120 | } | |
121 | EXPORT_SYMBOL(xfrm_get_type); | |
122 | ||
123 | int xfrm_dst_lookup(struct xfrm_dst **dst, struct flowi *fl, | |
124 | unsigned short family) | |
125 | { | |
126 | struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); | |
127 | int err = 0; | |
128 | ||
129 | if (unlikely(afinfo == NULL)) | |
130 | return -EAFNOSUPPORT; | |
131 | ||
132 | if (likely(afinfo->dst_lookup != NULL)) | |
133 | err = afinfo->dst_lookup(dst, fl); | |
134 | else | |
135 | err = -EINVAL; | |
136 | xfrm_policy_put_afinfo(afinfo); | |
137 | return err; | |
138 | } | |
139 | EXPORT_SYMBOL(xfrm_dst_lookup); | |
140 | ||
141 | void xfrm_put_type(struct xfrm_type *type) | |
142 | { | |
143 | module_put(type->owner); | |
144 | } | |
145 | ||
146 | static inline unsigned long make_jiffies(long secs) | |
147 | { | |
148 | if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ) | |
149 | return MAX_SCHEDULE_TIMEOUT-1; | |
150 | else | |
151 | return secs*HZ; | |
152 | } | |
153 | ||
154 | static void xfrm_policy_timer(unsigned long data) | |
155 | { | |
156 | struct xfrm_policy *xp = (struct xfrm_policy*)data; | |
157 | unsigned long now = (unsigned long)xtime.tv_sec; | |
158 | long next = LONG_MAX; | |
159 | int warn = 0; | |
160 | int dir; | |
161 | ||
162 | read_lock(&xp->lock); | |
163 | ||
164 | if (xp->dead) | |
165 | goto out; | |
166 | ||
167 | dir = xp->index & 7; | |
168 | ||
169 | if (xp->lft.hard_add_expires_seconds) { | |
170 | long tmo = xp->lft.hard_add_expires_seconds + | |
171 | xp->curlft.add_time - now; | |
172 | if (tmo <= 0) | |
173 | goto expired; | |
174 | if (tmo < next) | |
175 | next = tmo; | |
176 | } | |
177 | if (xp->lft.hard_use_expires_seconds) { | |
178 | long tmo = xp->lft.hard_use_expires_seconds + | |
179 | (xp->curlft.use_time ? : xp->curlft.add_time) - now; | |
180 | if (tmo <= 0) | |
181 | goto expired; | |
182 | if (tmo < next) | |
183 | next = tmo; | |
184 | } | |
185 | if (xp->lft.soft_add_expires_seconds) { | |
186 | long tmo = xp->lft.soft_add_expires_seconds + | |
187 | xp->curlft.add_time - now; | |
188 | if (tmo <= 0) { | |
189 | warn = 1; | |
190 | tmo = XFRM_KM_TIMEOUT; | |
191 | } | |
192 | if (tmo < next) | |
193 | next = tmo; | |
194 | } | |
195 | if (xp->lft.soft_use_expires_seconds) { | |
196 | long tmo = xp->lft.soft_use_expires_seconds + | |
197 | (xp->curlft.use_time ? : xp->curlft.add_time) - now; | |
198 | if (tmo <= 0) { | |
199 | warn = 1; | |
200 | tmo = XFRM_KM_TIMEOUT; | |
201 | } | |
202 | if (tmo < next) | |
203 | next = tmo; | |
204 | } | |
205 | ||
206 | if (warn) | |
207 | km_policy_expired(xp, dir, 0); | |
208 | if (next != LONG_MAX && | |
209 | !mod_timer(&xp->timer, jiffies + make_jiffies(next))) | |
210 | xfrm_pol_hold(xp); | |
211 | ||
212 | out: | |
213 | read_unlock(&xp->lock); | |
214 | xfrm_pol_put(xp); | |
215 | return; | |
216 | ||
217 | expired: | |
218 | read_unlock(&xp->lock); | |
219 | km_policy_expired(xp, dir, 1); | |
220 | xfrm_policy_delete(xp, dir); | |
221 | xfrm_pol_put(xp); | |
222 | } | |
223 | ||
224 | ||
225 | /* Allocate xfrm_policy. Not used here, it is supposed to be used by pfkeyv2 | |
226 | * SPD calls. | |
227 | */ | |
228 | ||
229 | struct xfrm_policy *xfrm_policy_alloc(int gfp) | |
230 | { | |
231 | struct xfrm_policy *policy; | |
232 | ||
233 | policy = kmalloc(sizeof(struct xfrm_policy), gfp); | |
234 | ||
235 | if (policy) { | |
236 | memset(policy, 0, sizeof(struct xfrm_policy)); | |
237 | atomic_set(&policy->refcnt, 1); | |
238 | rwlock_init(&policy->lock); | |
239 | init_timer(&policy->timer); | |
240 | policy->timer.data = (unsigned long)policy; | |
241 | policy->timer.function = xfrm_policy_timer; | |
242 | } | |
243 | return policy; | |
244 | } | |
245 | EXPORT_SYMBOL(xfrm_policy_alloc); | |
246 | ||
247 | /* Destroy xfrm_policy: descendant resources must be released to this moment. */ | |
248 | ||
249 | void __xfrm_policy_destroy(struct xfrm_policy *policy) | |
250 | { | |
251 | if (!policy->dead) | |
252 | BUG(); | |
253 | ||
254 | if (policy->bundles) | |
255 | BUG(); | |
256 | ||
257 | if (del_timer(&policy->timer)) | |
258 | BUG(); | |
259 | ||
260 | kfree(policy); | |
261 | } | |
262 | EXPORT_SYMBOL(__xfrm_policy_destroy); | |
263 | ||
264 | static void xfrm_policy_gc_kill(struct xfrm_policy *policy) | |
265 | { | |
266 | struct dst_entry *dst; | |
267 | ||
268 | while ((dst = policy->bundles) != NULL) { | |
269 | policy->bundles = dst->next; | |
270 | dst_free(dst); | |
271 | } | |
272 | ||
273 | if (del_timer(&policy->timer)) | |
274 | atomic_dec(&policy->refcnt); | |
275 | ||
276 | if (atomic_read(&policy->refcnt) > 1) | |
277 | flow_cache_flush(); | |
278 | ||
279 | xfrm_pol_put(policy); | |
280 | } | |
281 | ||
282 | static void xfrm_policy_gc_task(void *data) | |
283 | { | |
284 | struct xfrm_policy *policy; | |
285 | struct list_head *entry, *tmp; | |
286 | struct list_head gc_list = LIST_HEAD_INIT(gc_list); | |
287 | ||
288 | spin_lock_bh(&xfrm_policy_gc_lock); | |
289 | list_splice_init(&xfrm_policy_gc_list, &gc_list); | |
290 | spin_unlock_bh(&xfrm_policy_gc_lock); | |
291 | ||
292 | list_for_each_safe(entry, tmp, &gc_list) { | |
293 | policy = list_entry(entry, struct xfrm_policy, list); | |
294 | xfrm_policy_gc_kill(policy); | |
295 | } | |
296 | } | |
297 | ||
298 | /* Rule must be locked. Release descentant resources, announce | |
299 | * entry dead. The rule must be unlinked from lists to the moment. | |
300 | */ | |
301 | ||
302 | static void xfrm_policy_kill(struct xfrm_policy *policy) | |
303 | { | |
304 | int dead; | |
305 | ||
306 | write_lock_bh(&policy->lock); | |
307 | dead = policy->dead; | |
308 | policy->dead = 1; | |
309 | write_unlock_bh(&policy->lock); | |
310 | ||
311 | if (unlikely(dead)) { | |
312 | WARN_ON(1); | |
313 | return; | |
314 | } | |
315 | ||
316 | spin_lock(&xfrm_policy_gc_lock); | |
317 | list_add(&policy->list, &xfrm_policy_gc_list); | |
318 | spin_unlock(&xfrm_policy_gc_lock); | |
319 | ||
320 | schedule_work(&xfrm_policy_gc_work); | |
321 | } | |
322 | ||
323 | /* Generate new index... KAME seems to generate them ordered by cost | |
324 | * of an absolute inpredictability of ordering of rules. This will not pass. */ | |
325 | static u32 xfrm_gen_index(int dir) | |
326 | { | |
327 | u32 idx; | |
328 | struct xfrm_policy *p; | |
329 | static u32 idx_generator; | |
330 | ||
331 | for (;;) { | |
332 | idx = (idx_generator | dir); | |
333 | idx_generator += 8; | |
334 | if (idx == 0) | |
335 | idx = 8; | |
336 | for (p = xfrm_policy_list[dir]; p; p = p->next) { | |
337 | if (p->index == idx) | |
338 | break; | |
339 | } | |
340 | if (!p) | |
341 | return idx; | |
342 | } | |
343 | } | |
344 | ||
345 | int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl) | |
346 | { | |
347 | struct xfrm_policy *pol, **p; | |
348 | struct xfrm_policy *delpol = NULL; | |
349 | struct xfrm_policy **newpos = NULL; | |
350 | ||
351 | write_lock_bh(&xfrm_policy_lock); | |
352 | for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL;) { | |
353 | if (!delpol && memcmp(&policy->selector, &pol->selector, sizeof(pol->selector)) == 0) { | |
354 | if (excl) { | |
355 | write_unlock_bh(&xfrm_policy_lock); | |
356 | return -EEXIST; | |
357 | } | |
358 | *p = pol->next; | |
359 | delpol = pol; | |
360 | if (policy->priority > pol->priority) | |
361 | continue; | |
362 | } else if (policy->priority >= pol->priority) { | |
363 | p = &pol->next; | |
364 | continue; | |
365 | } | |
366 | if (!newpos) | |
367 | newpos = p; | |
368 | if (delpol) | |
369 | break; | |
370 | p = &pol->next; | |
371 | } | |
372 | if (newpos) | |
373 | p = newpos; | |
374 | xfrm_pol_hold(policy); | |
375 | policy->next = *p; | |
376 | *p = policy; | |
377 | atomic_inc(&flow_cache_genid); | |
378 | policy->index = delpol ? delpol->index : xfrm_gen_index(dir); | |
379 | policy->curlft.add_time = (unsigned long)xtime.tv_sec; | |
380 | policy->curlft.use_time = 0; | |
381 | if (!mod_timer(&policy->timer, jiffies + HZ)) | |
382 | xfrm_pol_hold(policy); | |
383 | write_unlock_bh(&xfrm_policy_lock); | |
384 | ||
385 | if (delpol) { | |
386 | xfrm_policy_kill(delpol); | |
387 | } | |
388 | return 0; | |
389 | } | |
390 | EXPORT_SYMBOL(xfrm_policy_insert); | |
391 | ||
392 | struct xfrm_policy *xfrm_policy_bysel(int dir, struct xfrm_selector *sel, | |
393 | int delete) | |
394 | { | |
395 | struct xfrm_policy *pol, **p; | |
396 | ||
397 | write_lock_bh(&xfrm_policy_lock); | |
398 | for (p = &xfrm_policy_list[dir]; (pol=*p)!=NULL; p = &pol->next) { | |
399 | if (memcmp(sel, &pol->selector, sizeof(*sel)) == 0) { | |
400 | xfrm_pol_hold(pol); | |
401 | if (delete) | |
402 | *p = pol->next; | |
403 | break; | |
404 | } | |
405 | } | |
406 | write_unlock_bh(&xfrm_policy_lock); | |
407 | ||
408 | if (pol && delete) { | |
409 | atomic_inc(&flow_cache_genid); | |
410 | xfrm_policy_kill(pol); | |
411 | } | |
412 | return pol; | |
413 | } | |
414 | EXPORT_SYMBOL(xfrm_policy_bysel); | |
415 | ||
416 | struct xfrm_policy *xfrm_policy_byid(int dir, u32 id, int delete) | |
417 | { | |
418 | struct xfrm_policy *pol, **p; | |
419 | ||
420 | write_lock_bh(&xfrm_policy_lock); | |
421 | for (p = &xfrm_policy_list[id & 7]; (pol=*p)!=NULL; p = &pol->next) { | |
422 | if (pol->index == id) { | |
423 | xfrm_pol_hold(pol); | |
424 | if (delete) | |
425 | *p = pol->next; | |
426 | break; | |
427 | } | |
428 | } | |
429 | write_unlock_bh(&xfrm_policy_lock); | |
430 | ||
431 | if (pol && delete) { | |
432 | atomic_inc(&flow_cache_genid); | |
433 | xfrm_policy_kill(pol); | |
434 | } | |
435 | return pol; | |
436 | } | |
437 | EXPORT_SYMBOL(xfrm_policy_byid); | |
438 | ||
439 | void xfrm_policy_flush(void) | |
440 | { | |
441 | struct xfrm_policy *xp; | |
442 | int dir; | |
443 | ||
444 | write_lock_bh(&xfrm_policy_lock); | |
445 | for (dir = 0; dir < XFRM_POLICY_MAX; dir++) { | |
446 | while ((xp = xfrm_policy_list[dir]) != NULL) { | |
447 | xfrm_policy_list[dir] = xp->next; | |
448 | write_unlock_bh(&xfrm_policy_lock); | |
449 | ||
450 | xfrm_policy_kill(xp); | |
451 | ||
452 | write_lock_bh(&xfrm_policy_lock); | |
453 | } | |
454 | } | |
455 | atomic_inc(&flow_cache_genid); | |
456 | write_unlock_bh(&xfrm_policy_lock); | |
457 | } | |
458 | EXPORT_SYMBOL(xfrm_policy_flush); | |
459 | ||
460 | int xfrm_policy_walk(int (*func)(struct xfrm_policy *, int, int, void*), | |
461 | void *data) | |
462 | { | |
463 | struct xfrm_policy *xp; | |
464 | int dir; | |
465 | int count = 0; | |
466 | int error = 0; | |
467 | ||
468 | read_lock_bh(&xfrm_policy_lock); | |
469 | for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) { | |
470 | for (xp = xfrm_policy_list[dir]; xp; xp = xp->next) | |
471 | count++; | |
472 | } | |
473 | ||
474 | if (count == 0) { | |
475 | error = -ENOENT; | |
476 | goto out; | |
477 | } | |
478 | ||
479 | for (dir = 0; dir < 2*XFRM_POLICY_MAX; dir++) { | |
480 | for (xp = xfrm_policy_list[dir]; xp; xp = xp->next) { | |
481 | error = func(xp, dir%XFRM_POLICY_MAX, --count, data); | |
482 | if (error) | |
483 | goto out; | |
484 | } | |
485 | } | |
486 | ||
487 | out: | |
488 | read_unlock_bh(&xfrm_policy_lock); | |
489 | return error; | |
490 | } | |
491 | EXPORT_SYMBOL(xfrm_policy_walk); | |
492 | ||
493 | /* Find policy to apply to this flow. */ | |
494 | ||
495 | static void xfrm_policy_lookup(struct flowi *fl, u16 family, u8 dir, | |
496 | void **objp, atomic_t **obj_refp) | |
497 | { | |
498 | struct xfrm_policy *pol; | |
499 | ||
500 | read_lock_bh(&xfrm_policy_lock); | |
501 | for (pol = xfrm_policy_list[dir]; pol; pol = pol->next) { | |
502 | struct xfrm_selector *sel = &pol->selector; | |
503 | int match; | |
504 | ||
505 | if (pol->family != family) | |
506 | continue; | |
507 | ||
508 | match = xfrm_selector_match(sel, fl, family); | |
509 | if (match) { | |
510 | xfrm_pol_hold(pol); | |
511 | break; | |
512 | } | |
513 | } | |
514 | read_unlock_bh(&xfrm_policy_lock); | |
515 | if ((*objp = (void *) pol) != NULL) | |
516 | *obj_refp = &pol->refcnt; | |
517 | } | |
518 | ||
519 | static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir, struct flowi *fl) | |
520 | { | |
521 | struct xfrm_policy *pol; | |
522 | ||
523 | read_lock_bh(&xfrm_policy_lock); | |
524 | if ((pol = sk->sk_policy[dir]) != NULL) { | |
525 | int match = xfrm_selector_match(&pol->selector, fl, | |
526 | sk->sk_family); | |
527 | if (match) | |
528 | xfrm_pol_hold(pol); | |
529 | else | |
530 | pol = NULL; | |
531 | } | |
532 | read_unlock_bh(&xfrm_policy_lock); | |
533 | return pol; | |
534 | } | |
535 | ||
536 | static void __xfrm_policy_link(struct xfrm_policy *pol, int dir) | |
537 | { | |
538 | pol->next = xfrm_policy_list[dir]; | |
539 | xfrm_policy_list[dir] = pol; | |
540 | xfrm_pol_hold(pol); | |
541 | } | |
542 | ||
543 | static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol, | |
544 | int dir) | |
545 | { | |
546 | struct xfrm_policy **polp; | |
547 | ||
548 | for (polp = &xfrm_policy_list[dir]; | |
549 | *polp != NULL; polp = &(*polp)->next) { | |
550 | if (*polp == pol) { | |
551 | *polp = pol->next; | |
552 | return pol; | |
553 | } | |
554 | } | |
555 | return NULL; | |
556 | } | |
557 | ||
558 | void xfrm_policy_delete(struct xfrm_policy *pol, int dir) | |
559 | { | |
560 | write_lock_bh(&xfrm_policy_lock); | |
561 | pol = __xfrm_policy_unlink(pol, dir); | |
562 | write_unlock_bh(&xfrm_policy_lock); | |
563 | if (pol) { | |
564 | if (dir < XFRM_POLICY_MAX) | |
565 | atomic_inc(&flow_cache_genid); | |
566 | xfrm_policy_kill(pol); | |
567 | } | |
568 | } | |
569 | ||
570 | int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol) | |
571 | { | |
572 | struct xfrm_policy *old_pol; | |
573 | ||
574 | write_lock_bh(&xfrm_policy_lock); | |
575 | old_pol = sk->sk_policy[dir]; | |
576 | sk->sk_policy[dir] = pol; | |
577 | if (pol) { | |
578 | pol->curlft.add_time = (unsigned long)xtime.tv_sec; | |
579 | pol->index = xfrm_gen_index(XFRM_POLICY_MAX+dir); | |
580 | __xfrm_policy_link(pol, XFRM_POLICY_MAX+dir); | |
581 | } | |
582 | if (old_pol) | |
583 | __xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir); | |
584 | write_unlock_bh(&xfrm_policy_lock); | |
585 | ||
586 | if (old_pol) { | |
587 | xfrm_policy_kill(old_pol); | |
588 | } | |
589 | return 0; | |
590 | } | |
591 | ||
592 | static struct xfrm_policy *clone_policy(struct xfrm_policy *old, int dir) | |
593 | { | |
594 | struct xfrm_policy *newp = xfrm_policy_alloc(GFP_ATOMIC); | |
595 | ||
596 | if (newp) { | |
597 | newp->selector = old->selector; | |
598 | newp->lft = old->lft; | |
599 | newp->curlft = old->curlft; | |
600 | newp->action = old->action; | |
601 | newp->flags = old->flags; | |
602 | newp->xfrm_nr = old->xfrm_nr; | |
603 | newp->index = old->index; | |
604 | memcpy(newp->xfrm_vec, old->xfrm_vec, | |
605 | newp->xfrm_nr*sizeof(struct xfrm_tmpl)); | |
606 | write_lock_bh(&xfrm_policy_lock); | |
607 | __xfrm_policy_link(newp, XFRM_POLICY_MAX+dir); | |
608 | write_unlock_bh(&xfrm_policy_lock); | |
609 | xfrm_pol_put(newp); | |
610 | } | |
611 | return newp; | |
612 | } | |
613 | ||
614 | int __xfrm_sk_clone_policy(struct sock *sk) | |
615 | { | |
616 | struct xfrm_policy *p0 = sk->sk_policy[0], | |
617 | *p1 = sk->sk_policy[1]; | |
618 | ||
619 | sk->sk_policy[0] = sk->sk_policy[1] = NULL; | |
620 | if (p0 && (sk->sk_policy[0] = clone_policy(p0, 0)) == NULL) | |
621 | return -ENOMEM; | |
622 | if (p1 && (sk->sk_policy[1] = clone_policy(p1, 1)) == NULL) | |
623 | return -ENOMEM; | |
624 | return 0; | |
625 | } | |
626 | ||
627 | /* Resolve list of templates for the flow, given policy. */ | |
628 | ||
629 | static int | |
630 | xfrm_tmpl_resolve(struct xfrm_policy *policy, struct flowi *fl, | |
631 | struct xfrm_state **xfrm, | |
632 | unsigned short family) | |
633 | { | |
634 | int nx; | |
635 | int i, error; | |
636 | xfrm_address_t *daddr = xfrm_flowi_daddr(fl, family); | |
637 | xfrm_address_t *saddr = xfrm_flowi_saddr(fl, family); | |
638 | ||
639 | for (nx=0, i = 0; i < policy->xfrm_nr; i++) { | |
640 | struct xfrm_state *x; | |
641 | xfrm_address_t *remote = daddr; | |
642 | xfrm_address_t *local = saddr; | |
643 | struct xfrm_tmpl *tmpl = &policy->xfrm_vec[i]; | |
644 | ||
645 | if (tmpl->mode) { | |
646 | remote = &tmpl->id.daddr; | |
647 | local = &tmpl->saddr; | |
648 | } | |
649 | ||
650 | x = xfrm_state_find(remote, local, fl, tmpl, policy, &error, family); | |
651 | ||
652 | if (x && x->km.state == XFRM_STATE_VALID) { | |
653 | xfrm[nx++] = x; | |
654 | daddr = remote; | |
655 | saddr = local; | |
656 | continue; | |
657 | } | |
658 | if (x) { | |
659 | error = (x->km.state == XFRM_STATE_ERROR ? | |
660 | -EINVAL : -EAGAIN); | |
661 | xfrm_state_put(x); | |
662 | } | |
663 | ||
664 | if (!tmpl->optional) | |
665 | goto fail; | |
666 | } | |
667 | return nx; | |
668 | ||
669 | fail: | |
670 | for (nx--; nx>=0; nx--) | |
671 | xfrm_state_put(xfrm[nx]); | |
672 | return error; | |
673 | } | |
674 | ||
675 | /* Check that the bundle accepts the flow and its components are | |
676 | * still valid. | |
677 | */ | |
678 | ||
679 | static struct dst_entry * | |
680 | xfrm_find_bundle(struct flowi *fl, struct xfrm_policy *policy, unsigned short family) | |
681 | { | |
682 | struct dst_entry *x; | |
683 | struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); | |
684 | if (unlikely(afinfo == NULL)) | |
685 | return ERR_PTR(-EINVAL); | |
686 | x = afinfo->find_bundle(fl, policy); | |
687 | xfrm_policy_put_afinfo(afinfo); | |
688 | return x; | |
689 | } | |
690 | ||
691 | /* Allocate chain of dst_entry's, attach known xfrm's, calculate | |
692 | * all the metrics... Shortly, bundle a bundle. | |
693 | */ | |
694 | ||
695 | static int | |
696 | xfrm_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx, | |
697 | struct flowi *fl, struct dst_entry **dst_p, | |
698 | unsigned short family) | |
699 | { | |
700 | int err; | |
701 | struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); | |
702 | if (unlikely(afinfo == NULL)) | |
703 | return -EINVAL; | |
704 | err = afinfo->bundle_create(policy, xfrm, nx, fl, dst_p); | |
705 | xfrm_policy_put_afinfo(afinfo); | |
706 | return err; | |
707 | } | |
708 | ||
709 | static inline int policy_to_flow_dir(int dir) | |
710 | { | |
711 | if (XFRM_POLICY_IN == FLOW_DIR_IN && | |
712 | XFRM_POLICY_OUT == FLOW_DIR_OUT && | |
713 | XFRM_POLICY_FWD == FLOW_DIR_FWD) | |
714 | return dir; | |
715 | switch (dir) { | |
716 | default: | |
717 | case XFRM_POLICY_IN: | |
718 | return FLOW_DIR_IN; | |
719 | case XFRM_POLICY_OUT: | |
720 | return FLOW_DIR_OUT; | |
721 | case XFRM_POLICY_FWD: | |
722 | return FLOW_DIR_FWD; | |
723 | }; | |
724 | } | |
725 | ||
726 | static int stale_bundle(struct dst_entry *dst); | |
727 | ||
728 | /* Main function: finds/creates a bundle for given flow. | |
729 | * | |
730 | * At the moment we eat a raw IP route. Mostly to speed up lookups | |
731 | * on interfaces with disabled IPsec. | |
732 | */ | |
733 | int xfrm_lookup(struct dst_entry **dst_p, struct flowi *fl, | |
734 | struct sock *sk, int flags) | |
735 | { | |
736 | struct xfrm_policy *policy; | |
737 | struct xfrm_state *xfrm[XFRM_MAX_DEPTH]; | |
738 | struct dst_entry *dst, *dst_orig = *dst_p; | |
739 | int nx = 0; | |
740 | int err; | |
741 | u32 genid; | |
742 | u16 family = dst_orig->ops->family; | |
743 | restart: | |
744 | genid = atomic_read(&flow_cache_genid); | |
745 | policy = NULL; | |
746 | if (sk && sk->sk_policy[1]) | |
747 | policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl); | |
748 | ||
749 | if (!policy) { | |
750 | /* To accelerate a bit... */ | |
751 | if ((dst_orig->flags & DST_NOXFRM) || !xfrm_policy_list[XFRM_POLICY_OUT]) | |
752 | return 0; | |
753 | ||
754 | policy = flow_cache_lookup(fl, family, | |
755 | policy_to_flow_dir(XFRM_POLICY_OUT), | |
756 | xfrm_policy_lookup); | |
757 | } | |
758 | ||
759 | if (!policy) | |
760 | return 0; | |
761 | ||
762 | policy->curlft.use_time = (unsigned long)xtime.tv_sec; | |
763 | ||
764 | switch (policy->action) { | |
765 | case XFRM_POLICY_BLOCK: | |
766 | /* Prohibit the flow */ | |
767 | xfrm_pol_put(policy); | |
768 | return -EPERM; | |
769 | ||
770 | case XFRM_POLICY_ALLOW: | |
771 | if (policy->xfrm_nr == 0) { | |
772 | /* Flow passes not transformed. */ | |
773 | xfrm_pol_put(policy); | |
774 | return 0; | |
775 | } | |
776 | ||
777 | /* Try to find matching bundle. | |
778 | * | |
779 | * LATER: help from flow cache. It is optional, this | |
780 | * is required only for output policy. | |
781 | */ | |
782 | dst = xfrm_find_bundle(fl, policy, family); | |
783 | if (IS_ERR(dst)) { | |
784 | xfrm_pol_put(policy); | |
785 | return PTR_ERR(dst); | |
786 | } | |
787 | ||
788 | if (dst) | |
789 | break; | |
790 | ||
791 | nx = xfrm_tmpl_resolve(policy, fl, xfrm, family); | |
792 | ||
793 | if (unlikely(nx<0)) { | |
794 | err = nx; | |
795 | if (err == -EAGAIN && flags) { | |
796 | DECLARE_WAITQUEUE(wait, current); | |
797 | ||
798 | add_wait_queue(&km_waitq, &wait); | |
799 | set_current_state(TASK_INTERRUPTIBLE); | |
800 | schedule(); | |
801 | set_current_state(TASK_RUNNING); | |
802 | remove_wait_queue(&km_waitq, &wait); | |
803 | ||
804 | nx = xfrm_tmpl_resolve(policy, fl, xfrm, family); | |
805 | ||
806 | if (nx == -EAGAIN && signal_pending(current)) { | |
807 | err = -ERESTART; | |
808 | goto error; | |
809 | } | |
810 | if (nx == -EAGAIN || | |
811 | genid != atomic_read(&flow_cache_genid)) { | |
812 | xfrm_pol_put(policy); | |
813 | goto restart; | |
814 | } | |
815 | err = nx; | |
816 | } | |
817 | if (err < 0) | |
818 | goto error; | |
819 | } | |
820 | if (nx == 0) { | |
821 | /* Flow passes not transformed. */ | |
822 | xfrm_pol_put(policy); | |
823 | return 0; | |
824 | } | |
825 | ||
826 | dst = dst_orig; | |
827 | err = xfrm_bundle_create(policy, xfrm, nx, fl, &dst, family); | |
828 | ||
829 | if (unlikely(err)) { | |
830 | int i; | |
831 | for (i=0; i<nx; i++) | |
832 | xfrm_state_put(xfrm[i]); | |
833 | goto error; | |
834 | } | |
835 | ||
836 | write_lock_bh(&policy->lock); | |
837 | if (unlikely(policy->dead || stale_bundle(dst))) { | |
838 | /* Wow! While we worked on resolving, this | |
839 | * policy has gone. Retry. It is not paranoia, | |
840 | * we just cannot enlist new bundle to dead object. | |
841 | * We can't enlist stable bundles either. | |
842 | */ | |
843 | write_unlock_bh(&policy->lock); | |
844 | ||
845 | xfrm_pol_put(policy); | |
846 | if (dst) | |
847 | dst_free(dst); | |
848 | goto restart; | |
849 | } | |
850 | dst->next = policy->bundles; | |
851 | policy->bundles = dst; | |
852 | dst_hold(dst); | |
853 | write_unlock_bh(&policy->lock); | |
854 | } | |
855 | *dst_p = dst; | |
856 | dst_release(dst_orig); | |
857 | xfrm_pol_put(policy); | |
858 | return 0; | |
859 | ||
860 | error: | |
861 | dst_release(dst_orig); | |
862 | xfrm_pol_put(policy); | |
863 | *dst_p = NULL; | |
864 | return err; | |
865 | } | |
866 | EXPORT_SYMBOL(xfrm_lookup); | |
867 | ||
868 | /* When skb is transformed back to its "native" form, we have to | |
869 | * check policy restrictions. At the moment we make this in maximally | |
870 | * stupid way. Shame on me. :-) Of course, connected sockets must | |
871 | * have policy cached at them. | |
872 | */ | |
873 | ||
874 | static inline int | |
875 | xfrm_state_ok(struct xfrm_tmpl *tmpl, struct xfrm_state *x, | |
876 | unsigned short family) | |
877 | { | |
878 | if (xfrm_state_kern(x)) | |
879 | return tmpl->optional && !xfrm_state_addr_cmp(tmpl, x, family); | |
880 | return x->id.proto == tmpl->id.proto && | |
881 | (x->id.spi == tmpl->id.spi || !tmpl->id.spi) && | |
882 | (x->props.reqid == tmpl->reqid || !tmpl->reqid) && | |
883 | x->props.mode == tmpl->mode && | |
884 | (tmpl->aalgos & (1<<x->props.aalgo)) && | |
885 | !(x->props.mode && xfrm_state_addr_cmp(tmpl, x, family)); | |
886 | } | |
887 | ||
888 | static inline int | |
889 | xfrm_policy_ok(struct xfrm_tmpl *tmpl, struct sec_path *sp, int start, | |
890 | unsigned short family) | |
891 | { | |
892 | int idx = start; | |
893 | ||
894 | if (tmpl->optional) { | |
895 | if (!tmpl->mode) | |
896 | return start; | |
897 | } else | |
898 | start = -1; | |
899 | for (; idx < sp->len; idx++) { | |
900 | if (xfrm_state_ok(tmpl, sp->x[idx].xvec, family)) | |
901 | return ++idx; | |
902 | if (sp->x[idx].xvec->props.mode) | |
903 | break; | |
904 | } | |
905 | return start; | |
906 | } | |
907 | ||
908 | static int | |
909 | _decode_session(struct sk_buff *skb, struct flowi *fl, unsigned short family) | |
910 | { | |
911 | struct xfrm_policy_afinfo *afinfo = xfrm_policy_get_afinfo(family); | |
912 | ||
913 | if (unlikely(afinfo == NULL)) | |
914 | return -EAFNOSUPPORT; | |
915 | ||
916 | afinfo->decode_session(skb, fl); | |
917 | xfrm_policy_put_afinfo(afinfo); | |
918 | return 0; | |
919 | } | |
920 | ||
921 | static inline int secpath_has_tunnel(struct sec_path *sp, int k) | |
922 | { | |
923 | for (; k < sp->len; k++) { | |
924 | if (sp->x[k].xvec->props.mode) | |
925 | return 1; | |
926 | } | |
927 | ||
928 | return 0; | |
929 | } | |
930 | ||
931 | int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, | |
932 | unsigned short family) | |
933 | { | |
934 | struct xfrm_policy *pol; | |
935 | struct flowi fl; | |
936 | ||
937 | if (_decode_session(skb, &fl, family) < 0) | |
938 | return 0; | |
939 | ||
940 | /* First, check used SA against their selectors. */ | |
941 | if (skb->sp) { | |
942 | int i; | |
943 | ||
944 | for (i=skb->sp->len-1; i>=0; i--) { | |
945 | struct sec_decap_state *xvec = &(skb->sp->x[i]); | |
946 | if (!xfrm_selector_match(&xvec->xvec->sel, &fl, family)) | |
947 | return 0; | |
948 | ||
949 | /* If there is a post_input processor, try running it */ | |
950 | if (xvec->xvec->type->post_input && | |
951 | (xvec->xvec->type->post_input)(xvec->xvec, | |
952 | &(xvec->decap), | |
953 | skb) != 0) | |
954 | return 0; | |
955 | } | |
956 | } | |
957 | ||
958 | pol = NULL; | |
959 | if (sk && sk->sk_policy[dir]) | |
960 | pol = xfrm_sk_policy_lookup(sk, dir, &fl); | |
961 | ||
962 | if (!pol) | |
963 | pol = flow_cache_lookup(&fl, family, | |
964 | policy_to_flow_dir(dir), | |
965 | xfrm_policy_lookup); | |
966 | ||
967 | if (!pol) | |
968 | return !skb->sp || !secpath_has_tunnel(skb->sp, 0); | |
969 | ||
970 | pol->curlft.use_time = (unsigned long)xtime.tv_sec; | |
971 | ||
972 | if (pol->action == XFRM_POLICY_ALLOW) { | |
973 | struct sec_path *sp; | |
974 | static struct sec_path dummy; | |
975 | int i, k; | |
976 | ||
977 | if ((sp = skb->sp) == NULL) | |
978 | sp = &dummy; | |
979 | ||
980 | /* For each tunnel xfrm, find the first matching tmpl. | |
981 | * For each tmpl before that, find corresponding xfrm. | |
982 | * Order is _important_. Later we will implement | |
983 | * some barriers, but at the moment barriers | |
984 | * are implied between each two transformations. | |
985 | */ | |
986 | for (i = pol->xfrm_nr-1, k = 0; i >= 0; i--) { | |
987 | k = xfrm_policy_ok(pol->xfrm_vec+i, sp, k, family); | |
988 | if (k < 0) | |
989 | goto reject; | |
990 | } | |
991 | ||
992 | if (secpath_has_tunnel(sp, k)) | |
993 | goto reject; | |
994 | ||
995 | xfrm_pol_put(pol); | |
996 | return 1; | |
997 | } | |
998 | ||
999 | reject: | |
1000 | xfrm_pol_put(pol); | |
1001 | return 0; | |
1002 | } | |
1003 | EXPORT_SYMBOL(__xfrm_policy_check); | |
1004 | ||
1005 | int __xfrm_route_forward(struct sk_buff *skb, unsigned short family) | |
1006 | { | |
1007 | struct flowi fl; | |
1008 | ||
1009 | if (_decode_session(skb, &fl, family) < 0) | |
1010 | return 0; | |
1011 | ||
1012 | return xfrm_lookup(&skb->dst, &fl, NULL, 0) == 0; | |
1013 | } | |
1014 | EXPORT_SYMBOL(__xfrm_route_forward); | |
1015 | ||
1016 | /* Optimize later using cookies and generation ids. */ | |
1017 | ||
1018 | static struct dst_entry *xfrm_dst_check(struct dst_entry *dst, u32 cookie) | |
1019 | { | |
1020 | if (!stale_bundle(dst)) | |
1021 | return dst; | |
1022 | ||
1023 | return NULL; | |
1024 | } | |
1025 | ||
1026 | static int stale_bundle(struct dst_entry *dst) | |
1027 | { | |
1028 | return !xfrm_bundle_ok((struct xfrm_dst *)dst, NULL, AF_UNSPEC); | |
1029 | } | |
1030 | ||
aabc9761 | 1031 | void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev) |
1da177e4 | 1032 | { |
1da177e4 LT |
1033 | while ((dst = dst->child) && dst->xfrm && dst->dev == dev) { |
1034 | dst->dev = &loopback_dev; | |
1035 | dev_hold(&loopback_dev); | |
1036 | dev_put(dev); | |
1037 | } | |
1038 | } | |
aabc9761 | 1039 | EXPORT_SYMBOL(xfrm_dst_ifdown); |
1da177e4 LT |
1040 | |
1041 | static void xfrm_link_failure(struct sk_buff *skb) | |
1042 | { | |
1043 | /* Impossible. Such dst must be popped before reaches point of failure. */ | |
1044 | return; | |
1045 | } | |
1046 | ||
1047 | static struct dst_entry *xfrm_negative_advice(struct dst_entry *dst) | |
1048 | { | |
1049 | if (dst) { | |
1050 | if (dst->obsolete) { | |
1051 | dst_release(dst); | |
1052 | dst = NULL; | |
1053 | } | |
1054 | } | |
1055 | return dst; | |
1056 | } | |
1057 | ||
1058 | static void xfrm_prune_bundles(int (*func)(struct dst_entry *)) | |
1059 | { | |
1060 | int i; | |
1061 | struct xfrm_policy *pol; | |
1062 | struct dst_entry *dst, **dstp, *gc_list = NULL; | |
1063 | ||
1064 | read_lock_bh(&xfrm_policy_lock); | |
1065 | for (i=0; i<2*XFRM_POLICY_MAX; i++) { | |
1066 | for (pol = xfrm_policy_list[i]; pol; pol = pol->next) { | |
1067 | write_lock(&pol->lock); | |
1068 | dstp = &pol->bundles; | |
1069 | while ((dst=*dstp) != NULL) { | |
1070 | if (func(dst)) { | |
1071 | *dstp = dst->next; | |
1072 | dst->next = gc_list; | |
1073 | gc_list = dst; | |
1074 | } else { | |
1075 | dstp = &dst->next; | |
1076 | } | |
1077 | } | |
1078 | write_unlock(&pol->lock); | |
1079 | } | |
1080 | } | |
1081 | read_unlock_bh(&xfrm_policy_lock); | |
1082 | ||
1083 | while (gc_list) { | |
1084 | dst = gc_list; | |
1085 | gc_list = dst->next; | |
1086 | dst_free(dst); | |
1087 | } | |
1088 | } | |
1089 | ||
1090 | static int unused_bundle(struct dst_entry *dst) | |
1091 | { | |
1092 | return !atomic_read(&dst->__refcnt); | |
1093 | } | |
1094 | ||
1095 | static void __xfrm_garbage_collect(void) | |
1096 | { | |
1097 | xfrm_prune_bundles(unused_bundle); | |
1098 | } | |
1099 | ||
1100 | int xfrm_flush_bundles(void) | |
1101 | { | |
1102 | xfrm_prune_bundles(stale_bundle); | |
1103 | return 0; | |
1104 | } | |
1105 | ||
1106 | void xfrm_init_pmtu(struct dst_entry *dst) | |
1107 | { | |
1108 | do { | |
1109 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
1110 | u32 pmtu, route_mtu_cached; | |
1111 | ||
1112 | pmtu = dst_mtu(dst->child); | |
1113 | xdst->child_mtu_cached = pmtu; | |
1114 | ||
1115 | pmtu = xfrm_state_mtu(dst->xfrm, pmtu); | |
1116 | ||
1117 | route_mtu_cached = dst_mtu(xdst->route); | |
1118 | xdst->route_mtu_cached = route_mtu_cached; | |
1119 | ||
1120 | if (pmtu > route_mtu_cached) | |
1121 | pmtu = route_mtu_cached; | |
1122 | ||
1123 | dst->metrics[RTAX_MTU-1] = pmtu; | |
1124 | } while ((dst = dst->next)); | |
1125 | } | |
1126 | ||
1127 | EXPORT_SYMBOL(xfrm_init_pmtu); | |
1128 | ||
1129 | /* Check that the bundle accepts the flow and its components are | |
1130 | * still valid. | |
1131 | */ | |
1132 | ||
1133 | int xfrm_bundle_ok(struct xfrm_dst *first, struct flowi *fl, int family) | |
1134 | { | |
1135 | struct dst_entry *dst = &first->u.dst; | |
1136 | struct xfrm_dst *last; | |
1137 | u32 mtu; | |
1138 | ||
92d63dec | 1139 | if (!dst_check(dst->path, ((struct xfrm_dst *)dst)->path_cookie) || |
1da177e4 LT |
1140 | (dst->dev && !netif_running(dst->dev))) |
1141 | return 0; | |
1142 | ||
1143 | last = NULL; | |
1144 | ||
1145 | do { | |
1146 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
1147 | ||
1148 | if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family)) | |
1149 | return 0; | |
1150 | if (dst->xfrm->km.state != XFRM_STATE_VALID) | |
1151 | return 0; | |
1152 | ||
1153 | mtu = dst_mtu(dst->child); | |
1154 | if (xdst->child_mtu_cached != mtu) { | |
1155 | last = xdst; | |
1156 | xdst->child_mtu_cached = mtu; | |
1157 | } | |
1158 | ||
92d63dec | 1159 | if (!dst_check(xdst->route, xdst->route_cookie)) |
1da177e4 LT |
1160 | return 0; |
1161 | mtu = dst_mtu(xdst->route); | |
1162 | if (xdst->route_mtu_cached != mtu) { | |
1163 | last = xdst; | |
1164 | xdst->route_mtu_cached = mtu; | |
1165 | } | |
1166 | ||
1167 | dst = dst->child; | |
1168 | } while (dst->xfrm); | |
1169 | ||
1170 | if (likely(!last)) | |
1171 | return 1; | |
1172 | ||
1173 | mtu = last->child_mtu_cached; | |
1174 | for (;;) { | |
1175 | dst = &last->u.dst; | |
1176 | ||
1177 | mtu = xfrm_state_mtu(dst->xfrm, mtu); | |
1178 | if (mtu > last->route_mtu_cached) | |
1179 | mtu = last->route_mtu_cached; | |
1180 | dst->metrics[RTAX_MTU-1] = mtu; | |
1181 | ||
1182 | if (last == first) | |
1183 | break; | |
1184 | ||
1185 | last = last->u.next; | |
1186 | last->child_mtu_cached = mtu; | |
1187 | } | |
1188 | ||
1189 | return 1; | |
1190 | } | |
1191 | ||
1192 | EXPORT_SYMBOL(xfrm_bundle_ok); | |
1193 | ||
1194 | /* Well... that's _TASK_. We need to scan through transformation | |
1195 | * list and figure out what mss tcp should generate in order to | |
1196 | * final datagram fit to mtu. Mama mia... :-) | |
1197 | * | |
1198 | * Apparently, some easy way exists, but we used to choose the most | |
1199 | * bizarre ones. :-) So, raising Kalashnikov... tra-ta-ta. | |
1200 | * | |
1201 | * Consider this function as something like dark humour. :-) | |
1202 | */ | |
1203 | static int xfrm_get_mss(struct dst_entry *dst, u32 mtu) | |
1204 | { | |
1205 | int res = mtu - dst->header_len; | |
1206 | ||
1207 | for (;;) { | |
1208 | struct dst_entry *d = dst; | |
1209 | int m = res; | |
1210 | ||
1211 | do { | |
1212 | struct xfrm_state *x = d->xfrm; | |
1213 | if (x) { | |
1214 | spin_lock_bh(&x->lock); | |
1215 | if (x->km.state == XFRM_STATE_VALID && | |
1216 | x->type && x->type->get_max_size) | |
1217 | m = x->type->get_max_size(d->xfrm, m); | |
1218 | else | |
1219 | m += x->props.header_len; | |
1220 | spin_unlock_bh(&x->lock); | |
1221 | } | |
1222 | } while ((d = d->child) != NULL); | |
1223 | ||
1224 | if (m <= mtu) | |
1225 | break; | |
1226 | res -= (m - mtu); | |
1227 | if (res < 88) | |
1228 | return mtu; | |
1229 | } | |
1230 | ||
1231 | return res + dst->header_len; | |
1232 | } | |
1233 | ||
1234 | int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo) | |
1235 | { | |
1236 | int err = 0; | |
1237 | if (unlikely(afinfo == NULL)) | |
1238 | return -EINVAL; | |
1239 | if (unlikely(afinfo->family >= NPROTO)) | |
1240 | return -EAFNOSUPPORT; | |
1241 | write_lock(&xfrm_policy_afinfo_lock); | |
1242 | if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL)) | |
1243 | err = -ENOBUFS; | |
1244 | else { | |
1245 | struct dst_ops *dst_ops = afinfo->dst_ops; | |
1246 | if (likely(dst_ops->kmem_cachep == NULL)) | |
1247 | dst_ops->kmem_cachep = xfrm_dst_cache; | |
1248 | if (likely(dst_ops->check == NULL)) | |
1249 | dst_ops->check = xfrm_dst_check; | |
1da177e4 LT |
1250 | if (likely(dst_ops->negative_advice == NULL)) |
1251 | dst_ops->negative_advice = xfrm_negative_advice; | |
1252 | if (likely(dst_ops->link_failure == NULL)) | |
1253 | dst_ops->link_failure = xfrm_link_failure; | |
1254 | if (likely(dst_ops->get_mss == NULL)) | |
1255 | dst_ops->get_mss = xfrm_get_mss; | |
1256 | if (likely(afinfo->garbage_collect == NULL)) | |
1257 | afinfo->garbage_collect = __xfrm_garbage_collect; | |
1258 | xfrm_policy_afinfo[afinfo->family] = afinfo; | |
1259 | } | |
1260 | write_unlock(&xfrm_policy_afinfo_lock); | |
1261 | return err; | |
1262 | } | |
1263 | EXPORT_SYMBOL(xfrm_policy_register_afinfo); | |
1264 | ||
1265 | int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo) | |
1266 | { | |
1267 | int err = 0; | |
1268 | if (unlikely(afinfo == NULL)) | |
1269 | return -EINVAL; | |
1270 | if (unlikely(afinfo->family >= NPROTO)) | |
1271 | return -EAFNOSUPPORT; | |
1272 | write_lock(&xfrm_policy_afinfo_lock); | |
1273 | if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) { | |
1274 | if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo)) | |
1275 | err = -EINVAL; | |
1276 | else { | |
1277 | struct dst_ops *dst_ops = afinfo->dst_ops; | |
1278 | xfrm_policy_afinfo[afinfo->family] = NULL; | |
1279 | dst_ops->kmem_cachep = NULL; | |
1280 | dst_ops->check = NULL; | |
1da177e4 LT |
1281 | dst_ops->negative_advice = NULL; |
1282 | dst_ops->link_failure = NULL; | |
1283 | dst_ops->get_mss = NULL; | |
1284 | afinfo->garbage_collect = NULL; | |
1285 | } | |
1286 | } | |
1287 | write_unlock(&xfrm_policy_afinfo_lock); | |
1288 | return err; | |
1289 | } | |
1290 | EXPORT_SYMBOL(xfrm_policy_unregister_afinfo); | |
1291 | ||
1292 | static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family) | |
1293 | { | |
1294 | struct xfrm_policy_afinfo *afinfo; | |
1295 | if (unlikely(family >= NPROTO)) | |
1296 | return NULL; | |
1297 | read_lock(&xfrm_policy_afinfo_lock); | |
1298 | afinfo = xfrm_policy_afinfo[family]; | |
1299 | if (likely(afinfo != NULL)) | |
1300 | read_lock(&afinfo->lock); | |
1301 | read_unlock(&xfrm_policy_afinfo_lock); | |
1302 | return afinfo; | |
1303 | } | |
1304 | ||
1305 | static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo) | |
1306 | { | |
1307 | if (unlikely(afinfo == NULL)) | |
1308 | return; | |
1309 | read_unlock(&afinfo->lock); | |
1310 | } | |
1311 | ||
1312 | static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr) | |
1313 | { | |
1314 | switch (event) { | |
1315 | case NETDEV_DOWN: | |
1316 | xfrm_flush_bundles(); | |
1317 | } | |
1318 | return NOTIFY_DONE; | |
1319 | } | |
1320 | ||
1321 | static struct notifier_block xfrm_dev_notifier = { | |
1322 | xfrm_dev_event, | |
1323 | NULL, | |
1324 | 0 | |
1325 | }; | |
1326 | ||
1327 | static void __init xfrm_policy_init(void) | |
1328 | { | |
1329 | xfrm_dst_cache = kmem_cache_create("xfrm_dst_cache", | |
1330 | sizeof(struct xfrm_dst), | |
1331 | 0, SLAB_HWCACHE_ALIGN, | |
1332 | NULL, NULL); | |
1333 | if (!xfrm_dst_cache) | |
1334 | panic("XFRM: failed to allocate xfrm_dst_cache\n"); | |
1335 | ||
1336 | INIT_WORK(&xfrm_policy_gc_work, xfrm_policy_gc_task, NULL); | |
1337 | register_netdevice_notifier(&xfrm_dev_notifier); | |
1338 | } | |
1339 | ||
1340 | void __init xfrm_init(void) | |
1341 | { | |
1342 | xfrm_state_init(); | |
1343 | xfrm_policy_init(); | |
1344 | xfrm_input_init(); | |
1345 | } | |
1346 |