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libertas: tweak association debug output
[linux/fpc-iii.git] / net / core / fib_rules.c
blob541728aa2baeaa22e2348907ee5b203fb2a1d962
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/list.h>
14 #include <net/net_namespace.h>
15 #include <net/sock.h>
16 #include <net/fib_rules.h>
17
18 int fib_default_rule_add(struct fib_rules_ops *ops,
19 u32 pref, u32 table, u32 flags)
20 {
21 struct fib_rule *r;
22
23 r = kzalloc(ops->rule_size, GFP_KERNEL);
24 if (r == NULL)
25 return -ENOMEM;
26
27 atomic_set(&r->refcnt, 1);
28 r->action = FR_ACT_TO_TBL;
29 r->pref = pref;
30 r->table = table;
31 r->flags = flags;
32
33 /* The lock is not required here, the list in unreacheable
34 * at the moment this function is called */
35 list_add_tail(&r->list, &ops->rules_list);
36 return 0;
37 }
38 EXPORT_SYMBOL(fib_default_rule_add);
39
40 static void notify_rule_change(struct net *net, int event,
41 struct fib_rule *rule,
42 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
43 u32 pid);
44
45 static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family)
46 {
47 struct fib_rules_ops *ops;
48
49 rcu_read_lock();
50 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
51 if (ops->family == family) {
52 if (!try_module_get(ops->owner))
53 ops = NULL;
54 rcu_read_unlock();
55 return ops;
56 }
57 }
58 rcu_read_unlock();
59
60 return NULL;
61 }
62
63 static void rules_ops_put(struct fib_rules_ops *ops)
64 {
65 if (ops)
66 module_put(ops->owner);
67 }
68
69 static void flush_route_cache(struct fib_rules_ops *ops)
70 {
71 if (ops->flush_cache)
72 ops->flush_cache();
73 }
74
75 int fib_rules_register(struct net *net, struct fib_rules_ops *ops)
76 {
77 int err = -EEXIST;
78 struct fib_rules_ops *o;
79
80 if (ops->rule_size < sizeof(struct fib_rule))
81 return -EINVAL;
82
83 if (ops->match == NULL || ops->configure == NULL ||
84 ops->compare == NULL || ops->fill == NULL ||
85 ops->action == NULL)
86 return -EINVAL;
87
88 spin_lock(&net->rules_mod_lock);
89 list_for_each_entry(o, &net->rules_ops, list)
90 if (ops->family == o->family)
91 goto errout;
92
93 hold_net(net);
94 list_add_tail_rcu(&ops->list, &net->rules_ops);
95 err = 0;
96 errout:
97 spin_unlock(&net->rules_mod_lock);
98
99 return err;
100 }
101
102 EXPORT_SYMBOL_GPL(fib_rules_register);
103
104 void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
105 {
106 struct fib_rule *rule, *tmp;
107
108 list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
109 list_del_rcu(&rule->list);
110 fib_rule_put(rule);
111 }
112 }
113 EXPORT_SYMBOL_GPL(fib_rules_cleanup_ops);
114
115 void fib_rules_unregister(struct net *net, struct fib_rules_ops *ops)
116 {
117
118 spin_lock(&net->rules_mod_lock);
119 list_del_rcu(&ops->list);
120 fib_rules_cleanup_ops(ops);
121 spin_unlock(&net->rules_mod_lock);
122
123 synchronize_rcu();
124 release_net(net);
125 }
126
127 EXPORT_SYMBOL_GPL(fib_rules_unregister);
128
129 static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
130 struct flowi *fl, int flags)
131 {
132 int ret = 0;
133
134 if (rule->ifindex && (rule->ifindex != fl->iif))
135 goto out;
136
137 if ((rule->mark ^ fl->mark) & rule->mark_mask)
138 goto out;
139
140 ret = ops->match(rule, fl, flags);
141 out:
142 return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
143 }
144
145 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
146 int flags, struct fib_lookup_arg *arg)
147 {
148 struct fib_rule *rule;
149 int err;
150
151 rcu_read_lock();
152
153 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
154 jumped:
155 if (!fib_rule_match(rule, ops, fl, flags))
156 continue;
157
158 if (rule->action == FR_ACT_GOTO) {
159 struct fib_rule *target;
160
161 target = rcu_dereference(rule->ctarget);
162 if (target == NULL) {
163 continue;
164 } else {
165 rule = target;
166 goto jumped;
167 }
168 } else if (rule->action == FR_ACT_NOP)
169 continue;
170 else
171 err = ops->action(rule, fl, flags, arg);
172
173 if (err != -EAGAIN) {
174 fib_rule_get(rule);
175 arg->rule = rule;
176 goto out;
177 }
178 }
179
180 err = -ESRCH;
181 out:
182 rcu_read_unlock();
183
184 return err;
185 }
186
187 EXPORT_SYMBOL_GPL(fib_rules_lookup);
188
189 static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb,
190 struct fib_rules_ops *ops)
191 {
192 int err = -EINVAL;
193
194 if (frh->src_len)
195 if (tb[FRA_SRC] == NULL ||
196 frh->src_len > (ops->addr_size * 8) ||
197 nla_len(tb[FRA_SRC]) != ops->addr_size)
198 goto errout;
199
200 if (frh->dst_len)
201 if (tb[FRA_DST] == NULL ||
202 frh->dst_len > (ops->addr_size * 8) ||
203 nla_len(tb[FRA_DST]) != ops->addr_size)
204 goto errout;
205
206 err = 0;
207 errout:
208 return err;
209 }
210
211 static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
212 {
213 struct net *net = skb->sk->sk_net;
214 struct fib_rule_hdr *frh = nlmsg_data(nlh);
215 struct fib_rules_ops *ops = NULL;
216 struct fib_rule *rule, *r, *last = NULL;
217 struct nlattr *tb[FRA_MAX+1];
218 int err = -EINVAL, unresolved = 0;
219
220 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
221 goto errout;
222
223 ops = lookup_rules_ops(net, frh->family);
224 if (ops == NULL) {
225 err = EAFNOSUPPORT;
226 goto errout;
227 }
228
229 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
230 if (err < 0)
231 goto errout;
232
233 err = validate_rulemsg(frh, tb, ops);
234 if (err < 0)
235 goto errout;
236
237 rule = kzalloc(ops->rule_size, GFP_KERNEL);
238 if (rule == NULL) {
239 err = -ENOMEM;
240 goto errout;
241 }
242
243 if (tb[FRA_PRIORITY])
244 rule->pref = nla_get_u32(tb[FRA_PRIORITY]);
245
246 if (tb[FRA_IFNAME]) {
247 struct net_device *dev;
248
249 rule->ifindex = -1;
250 nla_strlcpy(rule->ifname, tb[FRA_IFNAME], IFNAMSIZ);
251 dev = __dev_get_by_name(net, rule->ifname);
252 if (dev)
253 rule->ifindex = dev->ifindex;
254 }
255
256 if (tb[FRA_FWMARK]) {
257 rule->mark = nla_get_u32(tb[FRA_FWMARK]);
258 if (rule->mark)
259 /* compatibility: if the mark value is non-zero all bits
260 * are compared unless a mask is explicitly specified.
261 */
262 rule->mark_mask = 0xFFFFFFFF;
263 }
264
265 if (tb[FRA_FWMASK])
266 rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
267
268 rule->action = frh->action;
269 rule->flags = frh->flags;
270 rule->table = frh_get_table(frh, tb);
271
272 if (!rule->pref && ops->default_pref)
273 rule->pref = ops->default_pref(ops);
274
275 err = -EINVAL;
276 if (tb[FRA_GOTO]) {
277 if (rule->action != FR_ACT_GOTO)
278 goto errout_free;
279
280 rule->target = nla_get_u32(tb[FRA_GOTO]);
281 /* Backward jumps are prohibited to avoid endless loops */
282 if (rule->target <= rule->pref)
283 goto errout_free;
284
285 list_for_each_entry(r, &ops->rules_list, list) {
286 if (r->pref == rule->target) {
287 rule->ctarget = r;
288 break;
289 }
290 }
291
292 if (rule->ctarget == NULL)
293 unresolved = 1;
294 } else if (rule->action == FR_ACT_GOTO)
295 goto errout_free;
296
297 err = ops->configure(rule, skb, nlh, frh, tb);
298 if (err < 0)
299 goto errout_free;
300
301 list_for_each_entry(r, &ops->rules_list, list) {
302 if (r->pref > rule->pref)
303 break;
304 last = r;
305 }
306
307 fib_rule_get(rule);
308
309 if (ops->unresolved_rules) {
310 /*
311 * There are unresolved goto rules in the list, check if
312 * any of them are pointing to this new rule.
313 */
314 list_for_each_entry(r, &ops->rules_list, list) {
315 if (r->action == FR_ACT_GOTO &&
316 r->target == rule->pref) {
317 BUG_ON(r->ctarget != NULL);
318 rcu_assign_pointer(r->ctarget, rule);
319 if (--ops->unresolved_rules == 0)
320 break;
321 }
322 }
323 }
324
325 if (rule->action == FR_ACT_GOTO)
326 ops->nr_goto_rules++;
327
328 if (unresolved)
329 ops->unresolved_rules++;
330
331 if (last)
332 list_add_rcu(&rule->list, &last->list);
333 else
334 list_add_rcu(&rule->list, &ops->rules_list);
335
336 notify_rule_change(net, RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).pid);
337 flush_route_cache(ops);
338 rules_ops_put(ops);
339 return 0;
340
341 errout_free:
342 kfree(rule);
343 errout:
344 rules_ops_put(ops);
345 return err;
346 }
347
348 static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
349 {
350 struct net *net = skb->sk->sk_net;
351 struct fib_rule_hdr *frh = nlmsg_data(nlh);
352 struct fib_rules_ops *ops = NULL;
353 struct fib_rule *rule, *tmp;
354 struct nlattr *tb[FRA_MAX+1];
355 int err = -EINVAL;
356
357 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
358 goto errout;
359
360 ops = lookup_rules_ops(net, frh->family);
361 if (ops == NULL) {
362 err = EAFNOSUPPORT;
363 goto errout;
364 }
365
366 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
367 if (err < 0)
368 goto errout;
369
370 err = validate_rulemsg(frh, tb, ops);
371 if (err < 0)
372 goto errout;
373
374 list_for_each_entry(rule, &ops->rules_list, list) {
375 if (frh->action && (frh->action != rule->action))
376 continue;
377
378 if (frh->table && (frh_get_table(frh, tb) != rule->table))
379 continue;
380
381 if (tb[FRA_PRIORITY] &&
382 (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
383 continue;
384
385 if (tb[FRA_IFNAME] &&
386 nla_strcmp(tb[FRA_IFNAME], rule->ifname))
387 continue;
388
389 if (tb[FRA_FWMARK] &&
390 (rule->mark != nla_get_u32(tb[FRA_FWMARK])))
391 continue;
392
393 if (tb[FRA_FWMASK] &&
394 (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK])))
395 continue;
396
397 if (!ops->compare(rule, frh, tb))
398 continue;
399
400 if (rule->flags & FIB_RULE_PERMANENT) {
401 err = -EPERM;
402 goto errout;
403 }
404
405 list_del_rcu(&rule->list);
406
407 if (rule->action == FR_ACT_GOTO)
408 ops->nr_goto_rules--;
409
410 /*
411 * Check if this rule is a target to any of them. If so,
412 * disable them. As this operation is eventually very
413 * expensive, it is only performed if goto rules have
414 * actually been added.
415 */
416 if (ops->nr_goto_rules > 0) {
417 list_for_each_entry(tmp, &ops->rules_list, list) {
418 if (tmp->ctarget == rule) {
419 rcu_assign_pointer(tmp->ctarget, NULL);
420 ops->unresolved_rules++;
421 }
422 }
423 }
424
425 synchronize_rcu();
426 notify_rule_change(net, RTM_DELRULE, rule, ops, nlh,
427 NETLINK_CB(skb).pid);
428 fib_rule_put(rule);
429 flush_route_cache(ops);
430 rules_ops_put(ops);
431 return 0;
432 }
433
434 err = -ENOENT;
435 errout:
436 rules_ops_put(ops);
437 return err;
438 }
439
440 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
441 struct fib_rule *rule)
442 {
443 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
444 + nla_total_size(IFNAMSIZ) /* FRA_IFNAME */
445 + nla_total_size(4) /* FRA_PRIORITY */
446 + nla_total_size(4) /* FRA_TABLE */
447 + nla_total_size(4) /* FRA_FWMARK */
448 + nla_total_size(4); /* FRA_FWMASK */
449
450 if (ops->nlmsg_payload)
451 payload += ops->nlmsg_payload(rule);
452
453 return payload;
454 }
455
456 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
457 u32 pid, u32 seq, int type, int flags,
458 struct fib_rules_ops *ops)
459 {
460 struct nlmsghdr *nlh;
461 struct fib_rule_hdr *frh;
462
463 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
464 if (nlh == NULL)
465 return -EMSGSIZE;
466
467 frh = nlmsg_data(nlh);
468 frh->table = rule->table;
469 NLA_PUT_U32(skb, FRA_TABLE, rule->table);
470 frh->res1 = 0;
471 frh->res2 = 0;
472 frh->action = rule->action;
473 frh->flags = rule->flags;
474
475 if (rule->action == FR_ACT_GOTO && rule->ctarget == NULL)
476 frh->flags |= FIB_RULE_UNRESOLVED;
477
478 if (rule->ifname[0]) {
479 NLA_PUT_STRING(skb, FRA_IFNAME, rule->ifname);
480
481 if (rule->ifindex == -1)
482 frh->flags |= FIB_RULE_DEV_DETACHED;
483 }
484
485 if (rule->pref)
486 NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref);
487
488 if (rule->mark)
489 NLA_PUT_U32(skb, FRA_FWMARK, rule->mark);
490
491 if (rule->mark_mask || rule->mark)
492 NLA_PUT_U32(skb, FRA_FWMASK, rule->mark_mask);
493
494 if (rule->target)
495 NLA_PUT_U32(skb, FRA_GOTO, rule->target);
496
497 if (ops->fill(rule, skb, nlh, frh) < 0)
498 goto nla_put_failure;
499
500 return nlmsg_end(skb, nlh);
501
502 nla_put_failure:
503 nlmsg_cancel(skb, nlh);
504 return -EMSGSIZE;
505 }
506
507 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
508 struct fib_rules_ops *ops)
509 {
510 int idx = 0;
511 struct fib_rule *rule;
512
513 list_for_each_entry(rule, &ops->rules_list, list) {
514 if (idx < cb->args[1])
515 goto skip;
516
517 if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid,
518 cb->nlh->nlmsg_seq, RTM_NEWRULE,
519 NLM_F_MULTI, ops) < 0)
520 break;
521 skip:
522 idx++;
523 }
524 cb->args[1] = idx;
525 rules_ops_put(ops);
526
527 return skb->len;
528 }
529
530 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
531 {
532 struct net *net = skb->sk->sk_net;
533 struct fib_rules_ops *ops;
534 int idx = 0, family;
535
536 family = rtnl_msg_family(cb->nlh);
537 if (family != AF_UNSPEC) {
538 /* Protocol specific dump request */
539 ops = lookup_rules_ops(net, family);
540 if (ops == NULL)
541 return -EAFNOSUPPORT;
542
543 return dump_rules(skb, cb, ops);
544 }
545
546 rcu_read_lock();
547 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
548 if (idx < cb->args[0] || !try_module_get(ops->owner))
549 goto skip;
550
551 if (dump_rules(skb, cb, ops) < 0)
552 break;
553
554 cb->args[1] = 0;
555 skip:
556 idx++;
557 }
558 rcu_read_unlock();
559 cb->args[0] = idx;
560
561 return skb->len;
562 }
563
564 static void notify_rule_change(struct net *net, int event, struct fib_rule *rule,
565 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
566 u32 pid)
567 {
568 struct sk_buff *skb;
569 int err = -ENOBUFS;
570
571 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
572 if (skb == NULL)
573 goto errout;
574
575 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
576 if (err < 0) {
577 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
578 WARN_ON(err == -EMSGSIZE);
579 kfree_skb(skb);
580 goto errout;
581 }
582 err = rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
583 errout:
584 if (err < 0)
585 rtnl_set_sk_err(net, ops->nlgroup, err);
586 }
587
588 static void attach_rules(struct list_head *rules, struct net_device *dev)
589 {
590 struct fib_rule *rule;
591
592 list_for_each_entry(rule, rules, list) {
593 if (rule->ifindex == -1 &&
594 strcmp(dev->name, rule->ifname) == 0)
595 rule->ifindex = dev->ifindex;
596 }
597 }
598
599 static void detach_rules(struct list_head *rules, struct net_device *dev)
600 {
601 struct fib_rule *rule;
602
603 list_for_each_entry(rule, rules, list)
604 if (rule->ifindex == dev->ifindex)
605 rule->ifindex = -1;
606 }
607
608
609 static int fib_rules_event(struct notifier_block *this, unsigned long event,
610 void *ptr)
611 {
612 struct net_device *dev = ptr;
613 struct net *net = dev->nd_net;
614 struct fib_rules_ops *ops;
615
616 ASSERT_RTNL();
617 rcu_read_lock();
618
619 switch (event) {
620 case NETDEV_REGISTER:
621 list_for_each_entry(ops, &net->rules_ops, list)
622 attach_rules(&ops->rules_list, dev);
623 break;
624
625 case NETDEV_UNREGISTER:
626 list_for_each_entry(ops, &net->rules_ops, list)
627 detach_rules(&ops->rules_list, dev);
628 break;
629 }
630
631 rcu_read_unlock();
632
633 return NOTIFY_DONE;
634 }
635
636 static struct notifier_block fib_rules_notifier = {
637 .notifier_call = fib_rules_event,
638 };
639
640 static int fib_rules_net_init(struct net *net)
641 {
642 INIT_LIST_HEAD(&net->rules_ops);
643 spin_lock_init(&net->rules_mod_lock);
644 return 0;
645 }
646
647 static struct pernet_operations fib_rules_net_ops = {
648 .init = fib_rules_net_init,
649 };
650
651 static int __init fib_rules_init(void)
652 {
653 int err;
654 rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL);
655 rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL);
656 rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule);
657
658 err = register_netdevice_notifier(&fib_rules_notifier);
659 if (err < 0)
660 goto fail;
661
662 err = register_pernet_subsys(&fib_rules_net_ops);
663 if (err < 0)
664 goto fail_unregister;
665 return 0;
666
667 fail_unregister:
668 unregister_netdevice_notifier(&fib_rules_notifier);
669 fail:
670 rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
671 rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
672 rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
673 return err;
674 }
675
676 subsys_initcall(fib_rules_init);
Linux with added FPC-III support