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1 | /* | |
2 | * net/core/fib_rules.c Generic Routing Rules | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License as | |
6 | * published by the Free Software Foundation, version 2. | |
7 | * | |
8 | * Authors: Thomas Graf <tgraf@suug.ch> | |
9 | */ | |
10 | ||
11 | #include <linux/types.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/list.h> | |
15 | #include <linux/module.h> | |
16 | #include <net/net_namespace.h> | |
17 | #include <net/sock.h> | |
18 | #include <net/fib_rules.h> | |
19 | ||
20 | int fib_default_rule_add(struct fib_rules_ops *ops, | |
21 | u32 pref, u32 table, u32 flags) | |
22 | { | |
23 | struct fib_rule *r; | |
24 | ||
25 | r = kzalloc(ops->rule_size, GFP_KERNEL); | |
26 | if (r == NULL) | |
27 | return -ENOMEM; | |
28 | ||
29 | atomic_set(&r->refcnt, 1); | |
30 | r->action = FR_ACT_TO_TBL; | |
31 | r->pref = pref; | |
32 | r->table = table; | |
33 | r->flags = flags; | |
34 | r->fr_net = hold_net(ops->fro_net); | |
35 | ||
36 | /* The lock is not required here, the list in unreacheable | |
37 | * at the moment this function is called */ | |
38 | list_add_tail(&r->list, &ops->rules_list); | |
39 | return 0; | |
40 | } | |
41 | EXPORT_SYMBOL(fib_default_rule_add); | |
42 | ||
43 | u32 fib_default_rule_pref(struct fib_rules_ops *ops) | |
44 | { | |
45 | struct list_head *pos; | |
46 | struct fib_rule *rule; | |
47 | ||
48 | if (!list_empty(&ops->rules_list)) { | |
49 | pos = ops->rules_list.next; | |
50 | if (pos->next != &ops->rules_list) { | |
51 | rule = list_entry(pos->next, struct fib_rule, list); | |
52 | if (rule->pref) | |
53 | return rule->pref - 1; | |
54 | } | |
55 | } | |
56 | ||
57 | return 0; | |
58 | } | |
59 | EXPORT_SYMBOL(fib_default_rule_pref); | |
60 | ||
61 | static void notify_rule_change(int event, struct fib_rule *rule, | |
62 | struct fib_rules_ops *ops, struct nlmsghdr *nlh, | |
63 | u32 pid); | |
64 | ||
65 | static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family) | |
66 | { | |
67 | struct fib_rules_ops *ops; | |
68 | ||
69 | rcu_read_lock(); | |
70 | list_for_each_entry_rcu(ops, &net->rules_ops, list) { | |
71 | if (ops->family == family) { | |
72 | if (!try_module_get(ops->owner)) | |
73 | ops = NULL; | |
74 | rcu_read_unlock(); | |
75 | return ops; | |
76 | } | |
77 | } | |
78 | rcu_read_unlock(); | |
79 | ||
80 | return NULL; | |
81 | } | |
82 | ||
83 | static void rules_ops_put(struct fib_rules_ops *ops) | |
84 | { | |
85 | if (ops) | |
86 | module_put(ops->owner); | |
87 | } | |
88 | ||
89 | static void flush_route_cache(struct fib_rules_ops *ops) | |
90 | { | |
91 | if (ops->flush_cache) | |
92 | ops->flush_cache(ops); | |
93 | } | |
94 | ||
95 | static int __fib_rules_register(struct fib_rules_ops *ops) | |
96 | { | |
97 | int err = -EEXIST; | |
98 | struct fib_rules_ops *o; | |
99 | struct net *net; | |
100 | ||
101 | net = ops->fro_net; | |
102 | ||
103 | if (ops->rule_size < sizeof(struct fib_rule)) | |
104 | return -EINVAL; | |
105 | ||
106 | if (ops->match == NULL || ops->configure == NULL || | |
107 | ops->compare == NULL || ops->fill == NULL || | |
108 | ops->action == NULL) | |
109 | return -EINVAL; | |
110 | ||
111 | spin_lock(&net->rules_mod_lock); | |
112 | list_for_each_entry(o, &net->rules_ops, list) | |
113 | if (ops->family == o->family) | |
114 | goto errout; | |
115 | ||
116 | hold_net(net); | |
117 | list_add_tail_rcu(&ops->list, &net->rules_ops); | |
118 | err = 0; | |
119 | errout: | |
120 | spin_unlock(&net->rules_mod_lock); | |
121 | ||
122 | return err; | |
123 | } | |
124 | ||
125 | struct fib_rules_ops * | |
126 | fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net) | |
127 | { | |
128 | struct fib_rules_ops *ops; | |
129 | int err; | |
130 | ||
131 | ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL); | |
132 | if (ops == NULL) | |
133 | return ERR_PTR(-ENOMEM); | |
134 | ||
135 | INIT_LIST_HEAD(&ops->rules_list); | |
136 | ops->fro_net = net; | |
137 | ||
138 | err = __fib_rules_register(ops); | |
139 | if (err) { | |
140 | kfree(ops); | |
141 | ops = ERR_PTR(err); | |
142 | } | |
143 | ||
144 | return ops; | |
145 | } | |
146 | EXPORT_SYMBOL_GPL(fib_rules_register); | |
147 | ||
148 | static void fib_rules_cleanup_ops(struct fib_rules_ops *ops) | |
149 | { | |
150 | struct fib_rule *rule, *tmp; | |
151 | ||
152 | list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) { | |
153 | list_del_rcu(&rule->list); | |
154 | if (ops->delete) | |
155 | ops->delete(rule); | |
156 | fib_rule_put(rule); | |
157 | } | |
158 | } | |
159 | ||
160 | static void fib_rules_put_rcu(struct rcu_head *head) | |
161 | { | |
162 | struct fib_rules_ops *ops = container_of(head, struct fib_rules_ops, rcu); | |
163 | struct net *net = ops->fro_net; | |
164 | ||
165 | release_net(net); | |
166 | kfree(ops); | |
167 | } | |
168 | ||
169 | void fib_rules_unregister(struct fib_rules_ops *ops) | |
170 | { | |
171 | struct net *net = ops->fro_net; | |
172 | ||
173 | spin_lock(&net->rules_mod_lock); | |
174 | list_del_rcu(&ops->list); | |
175 | fib_rules_cleanup_ops(ops); | |
176 | spin_unlock(&net->rules_mod_lock); | |
177 | ||
178 | call_rcu(&ops->rcu, fib_rules_put_rcu); | |
179 | } | |
180 | EXPORT_SYMBOL_GPL(fib_rules_unregister); | |
181 | ||
182 | static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops, | |
183 | struct flowi *fl, int flags) | |
184 | { | |
185 | int ret = 0; | |
186 | ||
187 | if (rule->iifindex && (rule->iifindex != fl->flowi_iif)) | |
188 | goto out; | |
189 | ||
190 | if (rule->oifindex && (rule->oifindex != fl->flowi_oif)) | |
191 | goto out; | |
192 | ||
193 | if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask) | |
194 | goto out; | |
195 | ||
196 | ret = ops->match(rule, fl, flags); | |
197 | out: | |
198 | return (rule->flags & FIB_RULE_INVERT) ? !ret : ret; | |
199 | } | |
200 | ||
201 | int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl, | |
202 | int flags, struct fib_lookup_arg *arg) | |
203 | { | |
204 | struct fib_rule *rule; | |
205 | int err; | |
206 | ||
207 | rcu_read_lock(); | |
208 | ||
209 | list_for_each_entry_rcu(rule, &ops->rules_list, list) { | |
210 | jumped: | |
211 | if (!fib_rule_match(rule, ops, fl, flags)) | |
212 | continue; | |
213 | ||
214 | if (rule->action == FR_ACT_GOTO) { | |
215 | struct fib_rule *target; | |
216 | ||
217 | target = rcu_dereference(rule->ctarget); | |
218 | if (target == NULL) { | |
219 | continue; | |
220 | } else { | |
221 | rule = target; | |
222 | goto jumped; | |
223 | } | |
224 | } else if (rule->action == FR_ACT_NOP) | |
225 | continue; | |
226 | else | |
227 | err = ops->action(rule, fl, flags, arg); | |
228 | ||
229 | if (err != -EAGAIN) { | |
230 | if ((arg->flags & FIB_LOOKUP_NOREF) || | |
231 | likely(atomic_inc_not_zero(&rule->refcnt))) { | |
232 | arg->rule = rule; | |
233 | goto out; | |
234 | } | |
235 | break; | |
236 | } | |
237 | } | |
238 | ||
239 | err = -ESRCH; | |
240 | out: | |
241 | rcu_read_unlock(); | |
242 | ||
243 | return err; | |
244 | } | |
245 | EXPORT_SYMBOL_GPL(fib_rules_lookup); | |
246 | ||
247 | static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb, | |
248 | struct fib_rules_ops *ops) | |
249 | { | |
250 | int err = -EINVAL; | |
251 | ||
252 | if (frh->src_len) | |
253 | if (tb[FRA_SRC] == NULL || | |
254 | frh->src_len > (ops->addr_size * 8) || | |
255 | nla_len(tb[FRA_SRC]) != ops->addr_size) | |
256 | goto errout; | |
257 | ||
258 | if (frh->dst_len) | |
259 | if (tb[FRA_DST] == NULL || | |
260 | frh->dst_len > (ops->addr_size * 8) || | |
261 | nla_len(tb[FRA_DST]) != ops->addr_size) | |
262 | goto errout; | |
263 | ||
264 | err = 0; | |
265 | errout: | |
266 | return err; | |
267 | } | |
268 | ||
269 | static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) | |
270 | { | |
271 | struct net *net = sock_net(skb->sk); | |
272 | struct fib_rule_hdr *frh = nlmsg_data(nlh); | |
273 | struct fib_rules_ops *ops = NULL; | |
274 | struct fib_rule *rule, *r, *last = NULL; | |
275 | struct nlattr *tb[FRA_MAX+1]; | |
276 | int err = -EINVAL, unresolved = 0; | |
277 | ||
278 | if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) | |
279 | goto errout; | |
280 | ||
281 | ops = lookup_rules_ops(net, frh->family); | |
282 | if (ops == NULL) { | |
283 | err = -EAFNOSUPPORT; | |
284 | goto errout; | |
285 | } | |
286 | ||
287 | err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy); | |
288 | if (err < 0) | |
289 | goto errout; | |
290 | ||
291 | err = validate_rulemsg(frh, tb, ops); | |
292 | if (err < 0) | |
293 | goto errout; | |
294 | ||
295 | rule = kzalloc(ops->rule_size, GFP_KERNEL); | |
296 | if (rule == NULL) { | |
297 | err = -ENOMEM; | |
298 | goto errout; | |
299 | } | |
300 | rule->fr_net = hold_net(net); | |
301 | ||
302 | if (tb[FRA_PRIORITY]) | |
303 | rule->pref = nla_get_u32(tb[FRA_PRIORITY]); | |
304 | ||
305 | if (tb[FRA_IIFNAME]) { | |
306 | struct net_device *dev; | |
307 | ||
308 | rule->iifindex = -1; | |
309 | nla_strlcpy(rule->iifname, tb[FRA_IIFNAME], IFNAMSIZ); | |
310 | dev = __dev_get_by_name(net, rule->iifname); | |
311 | if (dev) | |
312 | rule->iifindex = dev->ifindex; | |
313 | } | |
314 | ||
315 | if (tb[FRA_OIFNAME]) { | |
316 | struct net_device *dev; | |
317 | ||
318 | rule->oifindex = -1; | |
319 | nla_strlcpy(rule->oifname, tb[FRA_OIFNAME], IFNAMSIZ); | |
320 | dev = __dev_get_by_name(net, rule->oifname); | |
321 | if (dev) | |
322 | rule->oifindex = dev->ifindex; | |
323 | } | |
324 | ||
325 | if (tb[FRA_FWMARK]) { | |
326 | rule->mark = nla_get_u32(tb[FRA_FWMARK]); | |
327 | if (rule->mark) | |
328 | /* compatibility: if the mark value is non-zero all bits | |
329 | * are compared unless a mask is explicitly specified. | |
330 | */ | |
331 | rule->mark_mask = 0xFFFFFFFF; | |
332 | } | |
333 | ||
334 | if (tb[FRA_FWMASK]) | |
335 | rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]); | |
336 | ||
337 | rule->action = frh->action; | |
338 | rule->flags = frh->flags; | |
339 | rule->table = frh_get_table(frh, tb); | |
340 | ||
341 | if (!tb[FRA_PRIORITY] && ops->default_pref) | |
342 | rule->pref = ops->default_pref(ops); | |
343 | ||
344 | err = -EINVAL; | |
345 | if (tb[FRA_GOTO]) { | |
346 | if (rule->action != FR_ACT_GOTO) | |
347 | goto errout_free; | |
348 | ||
349 | rule->target = nla_get_u32(tb[FRA_GOTO]); | |
350 | /* Backward jumps are prohibited to avoid endless loops */ | |
351 | if (rule->target <= rule->pref) | |
352 | goto errout_free; | |
353 | ||
354 | list_for_each_entry(r, &ops->rules_list, list) { | |
355 | if (r->pref == rule->target) { | |
356 | RCU_INIT_POINTER(rule->ctarget, r); | |
357 | break; | |
358 | } | |
359 | } | |
360 | ||
361 | if (rcu_dereference_protected(rule->ctarget, 1) == NULL) | |
362 | unresolved = 1; | |
363 | } else if (rule->action == FR_ACT_GOTO) | |
364 | goto errout_free; | |
365 | ||
366 | err = ops->configure(rule, skb, frh, tb); | |
367 | if (err < 0) | |
368 | goto errout_free; | |
369 | ||
370 | list_for_each_entry(r, &ops->rules_list, list) { | |
371 | if (r->pref > rule->pref) | |
372 | break; | |
373 | last = r; | |
374 | } | |
375 | ||
376 | fib_rule_get(rule); | |
377 | ||
378 | if (last) | |
379 | list_add_rcu(&rule->list, &last->list); | |
380 | else | |
381 | list_add_rcu(&rule->list, &ops->rules_list); | |
382 | ||
383 | if (ops->unresolved_rules) { | |
384 | /* | |
385 | * There are unresolved goto rules in the list, check if | |
386 | * any of them are pointing to this new rule. | |
387 | */ | |
388 | list_for_each_entry(r, &ops->rules_list, list) { | |
389 | if (r->action == FR_ACT_GOTO && | |
390 | r->target == rule->pref && | |
391 | rtnl_dereference(r->ctarget) == NULL) { | |
392 | rcu_assign_pointer(r->ctarget, rule); | |
393 | if (--ops->unresolved_rules == 0) | |
394 | break; | |
395 | } | |
396 | } | |
397 | } | |
398 | ||
399 | if (rule->action == FR_ACT_GOTO) | |
400 | ops->nr_goto_rules++; | |
401 | ||
402 | if (unresolved) | |
403 | ops->unresolved_rules++; | |
404 | ||
405 | notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).pid); | |
406 | flush_route_cache(ops); | |
407 | rules_ops_put(ops); | |
408 | return 0; | |
409 | ||
410 | errout_free: | |
411 | release_net(rule->fr_net); | |
412 | kfree(rule); | |
413 | errout: | |
414 | rules_ops_put(ops); | |
415 | return err; | |
416 | } | |
417 | ||
418 | static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) | |
419 | { | |
420 | struct net *net = sock_net(skb->sk); | |
421 | struct fib_rule_hdr *frh = nlmsg_data(nlh); | |
422 | struct fib_rules_ops *ops = NULL; | |
423 | struct fib_rule *rule, *tmp; | |
424 | struct nlattr *tb[FRA_MAX+1]; | |
425 | int err = -EINVAL; | |
426 | ||
427 | if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) | |
428 | goto errout; | |
429 | ||
430 | ops = lookup_rules_ops(net, frh->family); | |
431 | if (ops == NULL) { | |
432 | err = -EAFNOSUPPORT; | |
433 | goto errout; | |
434 | } | |
435 | ||
436 | err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy); | |
437 | if (err < 0) | |
438 | goto errout; | |
439 | ||
440 | err = validate_rulemsg(frh, tb, ops); | |
441 | if (err < 0) | |
442 | goto errout; | |
443 | ||
444 | list_for_each_entry(rule, &ops->rules_list, list) { | |
445 | if (frh->action && (frh->action != rule->action)) | |
446 | continue; | |
447 | ||
448 | if (frh->table && (frh_get_table(frh, tb) != rule->table)) | |
449 | continue; | |
450 | ||
451 | if (tb[FRA_PRIORITY] && | |
452 | (rule->pref != nla_get_u32(tb[FRA_PRIORITY]))) | |
453 | continue; | |
454 | ||
455 | if (tb[FRA_IIFNAME] && | |
456 | nla_strcmp(tb[FRA_IIFNAME], rule->iifname)) | |
457 | continue; | |
458 | ||
459 | if (tb[FRA_OIFNAME] && | |
460 | nla_strcmp(tb[FRA_OIFNAME], rule->oifname)) | |
461 | continue; | |
462 | ||
463 | if (tb[FRA_FWMARK] && | |
464 | (rule->mark != nla_get_u32(tb[FRA_FWMARK]))) | |
465 | continue; | |
466 | ||
467 | if (tb[FRA_FWMASK] && | |
468 | (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK]))) | |
469 | continue; | |
470 | ||
471 | if (!ops->compare(rule, frh, tb)) | |
472 | continue; | |
473 | ||
474 | if (rule->flags & FIB_RULE_PERMANENT) { | |
475 | err = -EPERM; | |
476 | goto errout; | |
477 | } | |
478 | ||
479 | list_del_rcu(&rule->list); | |
480 | ||
481 | if (rule->action == FR_ACT_GOTO) { | |
482 | ops->nr_goto_rules--; | |
483 | if (rtnl_dereference(rule->ctarget) == NULL) | |
484 | ops->unresolved_rules--; | |
485 | } | |
486 | ||
487 | /* | |
488 | * Check if this rule is a target to any of them. If so, | |
489 | * disable them. As this operation is eventually very | |
490 | * expensive, it is only performed if goto rules have | |
491 | * actually been added. | |
492 | */ | |
493 | if (ops->nr_goto_rules > 0) { | |
494 | list_for_each_entry(tmp, &ops->rules_list, list) { | |
495 | if (rtnl_dereference(tmp->ctarget) == rule) { | |
496 | RCU_INIT_POINTER(tmp->ctarget, NULL); | |
497 | ops->unresolved_rules++; | |
498 | } | |
499 | } | |
500 | } | |
501 | ||
502 | notify_rule_change(RTM_DELRULE, rule, ops, nlh, | |
503 | NETLINK_CB(skb).pid); | |
504 | if (ops->delete) | |
505 | ops->delete(rule); | |
506 | fib_rule_put(rule); | |
507 | flush_route_cache(ops); | |
508 | rules_ops_put(ops); | |
509 | return 0; | |
510 | } | |
511 | ||
512 | err = -ENOENT; | |
513 | errout: | |
514 | rules_ops_put(ops); | |
515 | return err; | |
516 | } | |
517 | ||
518 | static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops, | |
519 | struct fib_rule *rule) | |
520 | { | |
521 | size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr)) | |
522 | + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */ | |
523 | + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */ | |
524 | + nla_total_size(4) /* FRA_PRIORITY */ | |
525 | + nla_total_size(4) /* FRA_TABLE */ | |
526 | + nla_total_size(4) /* FRA_FWMARK */ | |
527 | + nla_total_size(4); /* FRA_FWMASK */ | |
528 | ||
529 | if (ops->nlmsg_payload) | |
530 | payload += ops->nlmsg_payload(rule); | |
531 | ||
532 | return payload; | |
533 | } | |
534 | ||
535 | static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule, | |
536 | u32 pid, u32 seq, int type, int flags, | |
537 | struct fib_rules_ops *ops) | |
538 | { | |
539 | struct nlmsghdr *nlh; | |
540 | struct fib_rule_hdr *frh; | |
541 | ||
542 | nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags); | |
543 | if (nlh == NULL) | |
544 | return -EMSGSIZE; | |
545 | ||
546 | frh = nlmsg_data(nlh); | |
547 | frh->family = ops->family; | |
548 | frh->table = rule->table; | |
549 | if (nla_put_u32(skb, FRA_TABLE, rule->table)) | |
550 | goto nla_put_failure; | |
551 | frh->res1 = 0; | |
552 | frh->res2 = 0; | |
553 | frh->action = rule->action; | |
554 | frh->flags = rule->flags; | |
555 | ||
556 | if (rule->action == FR_ACT_GOTO && | |
557 | rcu_access_pointer(rule->ctarget) == NULL) | |
558 | frh->flags |= FIB_RULE_UNRESOLVED; | |
559 | ||
560 | if (rule->iifname[0]) { | |
561 | if (nla_put_string(skb, FRA_IIFNAME, rule->iifname)) | |
562 | goto nla_put_failure; | |
563 | if (rule->iifindex == -1) | |
564 | frh->flags |= FIB_RULE_IIF_DETACHED; | |
565 | } | |
566 | ||
567 | if (rule->oifname[0]) { | |
568 | if (nla_put_string(skb, FRA_OIFNAME, rule->oifname)) | |
569 | goto nla_put_failure; | |
570 | if (rule->oifindex == -1) | |
571 | frh->flags |= FIB_RULE_OIF_DETACHED; | |
572 | } | |
573 | ||
574 | if ((rule->pref && | |
575 | nla_put_u32(skb, FRA_PRIORITY, rule->pref)) || | |
576 | (rule->mark && | |
577 | nla_put_u32(skb, FRA_FWMARK, rule->mark)) || | |
578 | ((rule->mark_mask || rule->mark) && | |
579 | nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) || | |
580 | (rule->target && | |
581 | nla_put_u32(skb, FRA_GOTO, rule->target))) | |
582 | goto nla_put_failure; | |
583 | if (ops->fill(rule, skb, frh) < 0) | |
584 | goto nla_put_failure; | |
585 | ||
586 | return nlmsg_end(skb, nlh); | |
587 | ||
588 | nla_put_failure: | |
589 | nlmsg_cancel(skb, nlh); | |
590 | return -EMSGSIZE; | |
591 | } | |
592 | ||
593 | static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb, | |
594 | struct fib_rules_ops *ops) | |
595 | { | |
596 | int idx = 0; | |
597 | struct fib_rule *rule; | |
598 | ||
599 | rcu_read_lock(); | |
600 | list_for_each_entry_rcu(rule, &ops->rules_list, list) { | |
601 | if (idx < cb->args[1]) | |
602 | goto skip; | |
603 | ||
604 | if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid, | |
605 | cb->nlh->nlmsg_seq, RTM_NEWRULE, | |
606 | NLM_F_MULTI, ops) < 0) | |
607 | break; | |
608 | skip: | |
609 | idx++; | |
610 | } | |
611 | rcu_read_unlock(); | |
612 | cb->args[1] = idx; | |
613 | rules_ops_put(ops); | |
614 | ||
615 | return skb->len; | |
616 | } | |
617 | ||
618 | static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb) | |
619 | { | |
620 | struct net *net = sock_net(skb->sk); | |
621 | struct fib_rules_ops *ops; | |
622 | int idx = 0, family; | |
623 | ||
624 | family = rtnl_msg_family(cb->nlh); | |
625 | if (family != AF_UNSPEC) { | |
626 | /* Protocol specific dump request */ | |
627 | ops = lookup_rules_ops(net, family); | |
628 | if (ops == NULL) | |
629 | return -EAFNOSUPPORT; | |
630 | ||
631 | return dump_rules(skb, cb, ops); | |
632 | } | |
633 | ||
634 | rcu_read_lock(); | |
635 | list_for_each_entry_rcu(ops, &net->rules_ops, list) { | |
636 | if (idx < cb->args[0] || !try_module_get(ops->owner)) | |
637 | goto skip; | |
638 | ||
639 | if (dump_rules(skb, cb, ops) < 0) | |
640 | break; | |
641 | ||
642 | cb->args[1] = 0; | |
643 | skip: | |
644 | idx++; | |
645 | } | |
646 | rcu_read_unlock(); | |
647 | cb->args[0] = idx; | |
648 | ||
649 | return skb->len; | |
650 | } | |
651 | ||
652 | static void notify_rule_change(int event, struct fib_rule *rule, | |
653 | struct fib_rules_ops *ops, struct nlmsghdr *nlh, | |
654 | u32 pid) | |
655 | { | |
656 | struct net *net; | |
657 | struct sk_buff *skb; | |
658 | int err = -ENOBUFS; | |
659 | ||
660 | net = ops->fro_net; | |
661 | skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL); | |
662 | if (skb == NULL) | |
663 | goto errout; | |
664 | ||
665 | err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops); | |
666 | if (err < 0) { | |
667 | /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */ | |
668 | WARN_ON(err == -EMSGSIZE); | |
669 | kfree_skb(skb); | |
670 | goto errout; | |
671 | } | |
672 | ||
673 | rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL); | |
674 | return; | |
675 | errout: | |
676 | if (err < 0) | |
677 | rtnl_set_sk_err(net, ops->nlgroup, err); | |
678 | } | |
679 | ||
680 | static void attach_rules(struct list_head *rules, struct net_device *dev) | |
681 | { | |
682 | struct fib_rule *rule; | |
683 | ||
684 | list_for_each_entry(rule, rules, list) { | |
685 | if (rule->iifindex == -1 && | |
686 | strcmp(dev->name, rule->iifname) == 0) | |
687 | rule->iifindex = dev->ifindex; | |
688 | if (rule->oifindex == -1 && | |
689 | strcmp(dev->name, rule->oifname) == 0) | |
690 | rule->oifindex = dev->ifindex; | |
691 | } | |
692 | } | |
693 | ||
694 | static void detach_rules(struct list_head *rules, struct net_device *dev) | |
695 | { | |
696 | struct fib_rule *rule; | |
697 | ||
698 | list_for_each_entry(rule, rules, list) { | |
699 | if (rule->iifindex == dev->ifindex) | |
700 | rule->iifindex = -1; | |
701 | if (rule->oifindex == dev->ifindex) | |
702 | rule->oifindex = -1; | |
703 | } | |
704 | } | |
705 | ||
706 | ||
707 | static int fib_rules_event(struct notifier_block *this, unsigned long event, | |
708 | void *ptr) | |
709 | { | |
710 | struct net_device *dev = ptr; | |
711 | struct net *net = dev_net(dev); | |
712 | struct fib_rules_ops *ops; | |
713 | ||
714 | ASSERT_RTNL(); | |
715 | ||
716 | switch (event) { | |
717 | case NETDEV_REGISTER: | |
718 | list_for_each_entry(ops, &net->rules_ops, list) | |
719 | attach_rules(&ops->rules_list, dev); | |
720 | break; | |
721 | ||
722 | case NETDEV_UNREGISTER: | |
723 | list_for_each_entry(ops, &net->rules_ops, list) | |
724 | detach_rules(&ops->rules_list, dev); | |
725 | break; | |
726 | } | |
727 | ||
728 | return NOTIFY_DONE; | |
729 | } | |
730 | ||
731 | static struct notifier_block fib_rules_notifier = { | |
732 | .notifier_call = fib_rules_event, | |
733 | }; | |
734 | ||
735 | static int __net_init fib_rules_net_init(struct net *net) | |
736 | { | |
737 | INIT_LIST_HEAD(&net->rules_ops); | |
738 | spin_lock_init(&net->rules_mod_lock); | |
739 | return 0; | |
740 | } | |
741 | ||
742 | static struct pernet_operations fib_rules_net_ops = { | |
743 | .init = fib_rules_net_init, | |
744 | }; | |
745 | ||
746 | static int __init fib_rules_init(void) | |
747 | { | |
748 | int err; | |
749 | rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, NULL); | |
750 | rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, NULL); | |
751 | rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, NULL); | |
752 | ||
753 | err = register_pernet_subsys(&fib_rules_net_ops); | |
754 | if (err < 0) | |
755 | goto fail; | |
756 | ||
757 | err = register_netdevice_notifier(&fib_rules_notifier); | |
758 | if (err < 0) | |
759 | goto fail_unregister; | |
760 | ||
761 | return 0; | |
762 | ||
763 | fail_unregister: | |
764 | unregister_pernet_subsys(&fib_rules_net_ops); | |
765 | fail: | |
766 | rtnl_unregister(PF_UNSPEC, RTM_NEWRULE); | |
767 | rtnl_unregister(PF_UNSPEC, RTM_DELRULE); | |
768 | rtnl_unregister(PF_UNSPEC, RTM_GETRULE); | |
769 | return err; | |
770 | } | |
771 | ||
772 | subsys_initcall(fib_rules_init); |