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zram: writeback throttle
[linux/fpc-iii.git] / net / core / fib_rules.c
blobffbb827723a236a6b187a10a33886561727ae0be
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 #include <net/ip_tunnels.h>
20
21 static const struct fib_kuid_range fib_kuid_range_unset = {
22 KUIDT_INIT(0),
23 KUIDT_INIT(~0),
24 };
25
26 bool fib_rule_matchall(const struct fib_rule *rule)
27 {
28 if (rule->iifindex || rule->oifindex || rule->mark || rule->tun_id ||
29 rule->flags)
30 return false;
31 if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1)
32 return false;
33 if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) ||
34 !uid_eq(rule->uid_range.end, fib_kuid_range_unset.end))
35 return false;
36 if (fib_rule_port_range_set(&rule->sport_range))
37 return false;
38 if (fib_rule_port_range_set(&rule->dport_range))
39 return false;
40 return true;
41 }
42 EXPORT_SYMBOL_GPL(fib_rule_matchall);
43
44 int fib_default_rule_add(struct fib_rules_ops *ops,
45 u32 pref, u32 table, u32 flags)
46 {
47 struct fib_rule *r;
48
49 r = kzalloc(ops->rule_size, GFP_KERNEL);
50 if (r == NULL)
51 return -ENOMEM;
52
53 refcount_set(&r->refcnt, 1);
54 r->action = FR_ACT_TO_TBL;
55 r->pref = pref;
56 r->table = table;
57 r->flags = flags;
58 r->proto = RTPROT_KERNEL;
59 r->fr_net = ops->fro_net;
60 r->uid_range = fib_kuid_range_unset;
61
62 r->suppress_prefixlen = -1;
63 r->suppress_ifgroup = -1;
64
65 /* The lock is not required here, the list in unreacheable
66 * at the moment this function is called */
67 list_add_tail(&r->list, &ops->rules_list);
68 return 0;
69 }
70 EXPORT_SYMBOL(fib_default_rule_add);
71
72 static u32 fib_default_rule_pref(struct fib_rules_ops *ops)
73 {
74 struct list_head *pos;
75 struct fib_rule *rule;
76
77 if (!list_empty(&ops->rules_list)) {
78 pos = ops->rules_list.next;
79 if (pos->next != &ops->rules_list) {
80 rule = list_entry(pos->next, struct fib_rule, list);
81 if (rule->pref)
82 return rule->pref - 1;
83 }
84 }
85
86 return 0;
87 }
88
89 static void notify_rule_change(int event, struct fib_rule *rule,
90 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
91 u32 pid);
92
93 static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family)
94 {
95 struct fib_rules_ops *ops;
96
97 rcu_read_lock();
98 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
99 if (ops->family == family) {
100 if (!try_module_get(ops->owner))
101 ops = NULL;
102 rcu_read_unlock();
103 return ops;
104 }
105 }
106 rcu_read_unlock();
107
108 return NULL;
109 }
110
111 static void rules_ops_put(struct fib_rules_ops *ops)
112 {
113 if (ops)
114 module_put(ops->owner);
115 }
116
117 static void flush_route_cache(struct fib_rules_ops *ops)
118 {
119 if (ops->flush_cache)
120 ops->flush_cache(ops);
121 }
122
123 static int __fib_rules_register(struct fib_rules_ops *ops)
124 {
125 int err = -EEXIST;
126 struct fib_rules_ops *o;
127 struct net *net;
128
129 net = ops->fro_net;
130
131 if (ops->rule_size < sizeof(struct fib_rule))
132 return -EINVAL;
133
134 if (ops->match == NULL || ops->configure == NULL ||
135 ops->compare == NULL || ops->fill == NULL ||
136 ops->action == NULL)
137 return -EINVAL;
138
139 spin_lock(&net->rules_mod_lock);
140 list_for_each_entry(o, &net->rules_ops, list)
141 if (ops->family == o->family)
142 goto errout;
143
144 list_add_tail_rcu(&ops->list, &net->rules_ops);
145 err = 0;
146 errout:
147 spin_unlock(&net->rules_mod_lock);
148
149 return err;
150 }
151
152 struct fib_rules_ops *
153 fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
154 {
155 struct fib_rules_ops *ops;
156 int err;
157
158 ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
159 if (ops == NULL)
160 return ERR_PTR(-ENOMEM);
161
162 INIT_LIST_HEAD(&ops->rules_list);
163 ops->fro_net = net;
164
165 err = __fib_rules_register(ops);
166 if (err) {
167 kfree(ops);
168 ops = ERR_PTR(err);
169 }
170
171 return ops;
172 }
173 EXPORT_SYMBOL_GPL(fib_rules_register);
174
175 static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
176 {
177 struct fib_rule *rule, *tmp;
178
179 list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
180 list_del_rcu(&rule->list);
181 if (ops->delete)
182 ops->delete(rule);
183 fib_rule_put(rule);
184 }
185 }
186
187 void fib_rules_unregister(struct fib_rules_ops *ops)
188 {
189 struct net *net = ops->fro_net;
190
191 spin_lock(&net->rules_mod_lock);
192 list_del_rcu(&ops->list);
193 spin_unlock(&net->rules_mod_lock);
194
195 fib_rules_cleanup_ops(ops);
196 kfree_rcu(ops, rcu);
197 }
198 EXPORT_SYMBOL_GPL(fib_rules_unregister);
199
200 static int uid_range_set(struct fib_kuid_range *range)
201 {
202 return uid_valid(range->start) && uid_valid(range->end);
203 }
204
205 static struct fib_kuid_range nla_get_kuid_range(struct nlattr **tb)
206 {
207 struct fib_rule_uid_range *in;
208 struct fib_kuid_range out;
209
210 in = (struct fib_rule_uid_range *)nla_data(tb[FRA_UID_RANGE]);
211
212 out.start = make_kuid(current_user_ns(), in->start);
213 out.end = make_kuid(current_user_ns(), in->end);
214
215 return out;
216 }
217
218 static int nla_put_uid_range(struct sk_buff *skb, struct fib_kuid_range *range)
219 {
220 struct fib_rule_uid_range out = {
221 from_kuid_munged(current_user_ns(), range->start),
222 from_kuid_munged(current_user_ns(), range->end)
223 };
224
225 return nla_put(skb, FRA_UID_RANGE, sizeof(out), &out);
226 }
227
228 static int nla_get_port_range(struct nlattr *pattr,
229 struct fib_rule_port_range *port_range)
230 {
231 const struct fib_rule_port_range *pr = nla_data(pattr);
232
233 if (!fib_rule_port_range_valid(pr))
234 return -EINVAL;
235
236 port_range->start = pr->start;
237 port_range->end = pr->end;
238
239 return 0;
240 }
241
242 static int nla_put_port_range(struct sk_buff *skb, int attrtype,
243 struct fib_rule_port_range *range)
244 {
245 return nla_put(skb, attrtype, sizeof(*range), range);
246 }
247
248 static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
249 struct flowi *fl, int flags,
250 struct fib_lookup_arg *arg)
251 {
252 int ret = 0;
253
254 if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
255 goto out;
256
257 if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
258 goto out;
259
260 if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
261 goto out;
262
263 if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id))
264 goto out;
265
266 if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg))
267 goto out;
268
269 if (uid_lt(fl->flowi_uid, rule->uid_range.start) ||
270 uid_gt(fl->flowi_uid, rule->uid_range.end))
271 goto out;
272
273 ret = ops->match(rule, fl, flags);
274 out:
275 return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
276 }
277
278 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
279 int flags, struct fib_lookup_arg *arg)
280 {
281 struct fib_rule *rule;
282 int err;
283
284 rcu_read_lock();
285
286 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
287 jumped:
288 if (!fib_rule_match(rule, ops, fl, flags, arg))
289 continue;
290
291 if (rule->action == FR_ACT_GOTO) {
292 struct fib_rule *target;
293
294 target = rcu_dereference(rule->ctarget);
295 if (target == NULL) {
296 continue;
297 } else {
298 rule = target;
299 goto jumped;
300 }
301 } else if (rule->action == FR_ACT_NOP)
302 continue;
303 else
304 err = ops->action(rule, fl, flags, arg);
305
306 if (!err && ops->suppress && ops->suppress(rule, arg))
307 continue;
308
309 if (err != -EAGAIN) {
310 if ((arg->flags & FIB_LOOKUP_NOREF) ||
311 likely(refcount_inc_not_zero(&rule->refcnt))) {
312 arg->rule = rule;
313 goto out;
314 }
315 break;
316 }
317 }
318
319 err = -ESRCH;
320 out:
321 rcu_read_unlock();
322
323 return err;
324 }
325 EXPORT_SYMBOL_GPL(fib_rules_lookup);
326
327 static int call_fib_rule_notifier(struct notifier_block *nb, struct net *net,
328 enum fib_event_type event_type,
329 struct fib_rule *rule, int family)
330 {
331 struct fib_rule_notifier_info info = {
332 .info.family = family,
333 .rule = rule,
334 };
335
336 return call_fib_notifier(nb, net, event_type, &info.info);
337 }
338
339 static int call_fib_rule_notifiers(struct net *net,
340 enum fib_event_type event_type,
341 struct fib_rule *rule,
342 struct fib_rules_ops *ops,
343 struct netlink_ext_ack *extack)
344 {
345 struct fib_rule_notifier_info info = {
346 .info.family = ops->family,
347 .info.extack = extack,
348 .rule = rule,
349 };
350
351 ops->fib_rules_seq++;
352 return call_fib_notifiers(net, event_type, &info.info);
353 }
354
355 /* Called with rcu_read_lock() */
356 int fib_rules_dump(struct net *net, struct notifier_block *nb, int family)
357 {
358 struct fib_rules_ops *ops;
359 struct fib_rule *rule;
360
361 ops = lookup_rules_ops(net, family);
362 if (!ops)
363 return -EAFNOSUPPORT;
364 list_for_each_entry_rcu(rule, &ops->rules_list, list)
365 call_fib_rule_notifier(nb, net, FIB_EVENT_RULE_ADD, rule,
366 family);
367 rules_ops_put(ops);
368
369 return 0;
370 }
371 EXPORT_SYMBOL_GPL(fib_rules_dump);
372
373 unsigned int fib_rules_seq_read(struct net *net, int family)
374 {
375 unsigned int fib_rules_seq;
376 struct fib_rules_ops *ops;
377
378 ASSERT_RTNL();
379
380 ops = lookup_rules_ops(net, family);
381 if (!ops)
382 return 0;
383 fib_rules_seq = ops->fib_rules_seq;
384 rules_ops_put(ops);
385
386 return fib_rules_seq;
387 }
388 EXPORT_SYMBOL_GPL(fib_rules_seq_read);
389
390 static struct fib_rule *rule_find(struct fib_rules_ops *ops,
391 struct fib_rule_hdr *frh,
392 struct nlattr **tb,
393 struct fib_rule *rule,
394 bool user_priority)
395 {
396 struct fib_rule *r;
397
398 list_for_each_entry(r, &ops->rules_list, list) {
399 if (rule->action && r->action != rule->action)
400 continue;
401
402 if (rule->table && r->table != rule->table)
403 continue;
404
405 if (user_priority && r->pref != rule->pref)
406 continue;
407
408 if (rule->iifname[0] &&
409 memcmp(r->iifname, rule->iifname, IFNAMSIZ))
410 continue;
411
412 if (rule->oifname[0] &&
413 memcmp(r->oifname, rule->oifname, IFNAMSIZ))
414 continue;
415
416 if (rule->mark && r->mark != rule->mark)
417 continue;
418
419 if (rule->suppress_ifgroup != -1 &&
420 r->suppress_ifgroup != rule->suppress_ifgroup)
421 continue;
422
423 if (rule->suppress_prefixlen != -1 &&
424 r->suppress_prefixlen != rule->suppress_prefixlen)
425 continue;
426
427 if (rule->mark_mask && r->mark_mask != rule->mark_mask)
428 continue;
429
430 if (rule->tun_id && r->tun_id != rule->tun_id)
431 continue;
432
433 if (r->fr_net != rule->fr_net)
434 continue;
435
436 if (rule->l3mdev && r->l3mdev != rule->l3mdev)
437 continue;
438
439 if (uid_range_set(&rule->uid_range) &&
440 (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
441 !uid_eq(r->uid_range.end, rule->uid_range.end)))
442 continue;
443
444 if (rule->ip_proto && r->ip_proto != rule->ip_proto)
445 continue;
446
447 if (rule->proto && r->proto != rule->proto)
448 continue;
449
450 if (fib_rule_port_range_set(&rule->sport_range) &&
451 !fib_rule_port_range_compare(&r->sport_range,
452 &rule->sport_range))
453 continue;
454
455 if (fib_rule_port_range_set(&rule->dport_range) &&
456 !fib_rule_port_range_compare(&r->dport_range,
457 &rule->dport_range))
458 continue;
459
460 if (!ops->compare(r, frh, tb))
461 continue;
462 return r;
463 }
464
465 return NULL;
466 }
467
468 #ifdef CONFIG_NET_L3_MASTER_DEV
469 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
470 struct netlink_ext_ack *extack)
471 {
472 nlrule->l3mdev = nla_get_u8(nla);
473 if (nlrule->l3mdev != 1) {
474 NL_SET_ERR_MSG(extack, "Invalid l3mdev attribute");
475 return -1;
476 }
477
478 return 0;
479 }
480 #else
481 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
482 struct netlink_ext_ack *extack)
483 {
484 NL_SET_ERR_MSG(extack, "l3mdev support is not enabled in kernel");
485 return -1;
486 }
487 #endif
488
489 static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh,
490 struct netlink_ext_ack *extack,
491 struct fib_rules_ops *ops,
492 struct nlattr *tb[],
493 struct fib_rule **rule,
494 bool *user_priority)
495 {
496 struct net *net = sock_net(skb->sk);
497 struct fib_rule_hdr *frh = nlmsg_data(nlh);
498 struct fib_rule *nlrule = NULL;
499 int err = -EINVAL;
500
501 if (frh->src_len)
502 if (!tb[FRA_SRC] ||
503 frh->src_len > (ops->addr_size * 8) ||
504 nla_len(tb[FRA_SRC]) != ops->addr_size) {
505 NL_SET_ERR_MSG(extack, "Invalid source address");
506 goto errout;
507 }
508
509 if (frh->dst_len)
510 if (!tb[FRA_DST] ||
511 frh->dst_len > (ops->addr_size * 8) ||
512 nla_len(tb[FRA_DST]) != ops->addr_size) {
513 NL_SET_ERR_MSG(extack, "Invalid dst address");
514 goto errout;
515 }
516
517 nlrule = kzalloc(ops->rule_size, GFP_KERNEL);
518 if (!nlrule) {
519 err = -ENOMEM;
520 goto errout;
521 }
522 refcount_set(&nlrule->refcnt, 1);
523 nlrule->fr_net = net;
524
525 if (tb[FRA_PRIORITY]) {
526 nlrule->pref = nla_get_u32(tb[FRA_PRIORITY]);
527 *user_priority = true;
528 } else {
529 nlrule->pref = fib_default_rule_pref(ops);
530 }
531
532 nlrule->proto = tb[FRA_PROTOCOL] ?
533 nla_get_u8(tb[FRA_PROTOCOL]) : RTPROT_UNSPEC;
534
535 if (tb[FRA_IIFNAME]) {
536 struct net_device *dev;
537
538 nlrule->iifindex = -1;
539 nla_strlcpy(nlrule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
540 dev = __dev_get_by_name(net, nlrule->iifname);
541 if (dev)
542 nlrule->iifindex = dev->ifindex;
543 }
544
545 if (tb[FRA_OIFNAME]) {
546 struct net_device *dev;
547
548 nlrule->oifindex = -1;
549 nla_strlcpy(nlrule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
550 dev = __dev_get_by_name(net, nlrule->oifname);
551 if (dev)
552 nlrule->oifindex = dev->ifindex;
553 }
554
555 if (tb[FRA_FWMARK]) {
556 nlrule->mark = nla_get_u32(tb[FRA_FWMARK]);
557 if (nlrule->mark)
558 /* compatibility: if the mark value is non-zero all bits
559 * are compared unless a mask is explicitly specified.
560 */
561 nlrule->mark_mask = 0xFFFFFFFF;
562 }
563
564 if (tb[FRA_FWMASK])
565 nlrule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
566
567 if (tb[FRA_TUN_ID])
568 nlrule->tun_id = nla_get_be64(tb[FRA_TUN_ID]);
569
570 err = -EINVAL;
571 if (tb[FRA_L3MDEV] &&
572 fib_nl2rule_l3mdev(tb[FRA_L3MDEV], nlrule, extack) < 0)
573 goto errout_free;
574
575 nlrule->action = frh->action;
576 nlrule->flags = frh->flags;
577 nlrule->table = frh_get_table(frh, tb);
578 if (tb[FRA_SUPPRESS_PREFIXLEN])
579 nlrule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
580 else
581 nlrule->suppress_prefixlen = -1;
582
583 if (tb[FRA_SUPPRESS_IFGROUP])
584 nlrule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
585 else
586 nlrule->suppress_ifgroup = -1;
587
588 if (tb[FRA_GOTO]) {
589 if (nlrule->action != FR_ACT_GOTO) {
590 NL_SET_ERR_MSG(extack, "Unexpected goto");
591 goto errout_free;
592 }
593
594 nlrule->target = nla_get_u32(tb[FRA_GOTO]);
595 /* Backward jumps are prohibited to avoid endless loops */
596 if (nlrule->target <= nlrule->pref) {
597 NL_SET_ERR_MSG(extack, "Backward goto not supported");
598 goto errout_free;
599 }
600 } else if (nlrule->action == FR_ACT_GOTO) {
601 NL_SET_ERR_MSG(extack, "Missing goto target for action goto");
602 goto errout_free;
603 }
604
605 if (nlrule->l3mdev && nlrule->table) {
606 NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive");
607 goto errout_free;
608 }
609
610 if (tb[FRA_UID_RANGE]) {
611 if (current_user_ns() != net->user_ns) {
612 err = -EPERM;
613 NL_SET_ERR_MSG(extack, "No permission to set uid");
614 goto errout_free;
615 }
616
617 nlrule->uid_range = nla_get_kuid_range(tb);
618
619 if (!uid_range_set(&nlrule->uid_range) ||
620 !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) {
621 NL_SET_ERR_MSG(extack, "Invalid uid range");
622 goto errout_free;
623 }
624 } else {
625 nlrule->uid_range = fib_kuid_range_unset;
626 }
627
628 if (tb[FRA_IP_PROTO])
629 nlrule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]);
630
631 if (tb[FRA_SPORT_RANGE]) {
632 err = nla_get_port_range(tb[FRA_SPORT_RANGE],
633 &nlrule->sport_range);
634 if (err) {
635 NL_SET_ERR_MSG(extack, "Invalid sport range");
636 goto errout_free;
637 }
638 }
639
640 if (tb[FRA_DPORT_RANGE]) {
641 err = nla_get_port_range(tb[FRA_DPORT_RANGE],
642 &nlrule->dport_range);
643 if (err) {
644 NL_SET_ERR_MSG(extack, "Invalid dport range");
645 goto errout_free;
646 }
647 }
648
649 *rule = nlrule;
650
651 return 0;
652
653 errout_free:
654 kfree(nlrule);
655 errout:
656 return err;
657 }
658
659 static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh,
660 struct nlattr **tb, struct fib_rule *rule)
661 {
662 struct fib_rule *r;
663
664 list_for_each_entry(r, &ops->rules_list, list) {
665 if (r->action != rule->action)
666 continue;
667
668 if (r->table != rule->table)
669 continue;
670
671 if (r->pref != rule->pref)
672 continue;
673
674 if (memcmp(r->iifname, rule->iifname, IFNAMSIZ))
675 continue;
676
677 if (memcmp(r->oifname, rule->oifname, IFNAMSIZ))
678 continue;
679
680 if (r->mark != rule->mark)
681 continue;
682
683 if (r->suppress_ifgroup != rule->suppress_ifgroup)
684 continue;
685
686 if (r->suppress_prefixlen != rule->suppress_prefixlen)
687 continue;
688
689 if (r->mark_mask != rule->mark_mask)
690 continue;
691
692 if (r->tun_id != rule->tun_id)
693 continue;
694
695 if (r->fr_net != rule->fr_net)
696 continue;
697
698 if (r->l3mdev != rule->l3mdev)
699 continue;
700
701 if (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
702 !uid_eq(r->uid_range.end, rule->uid_range.end))
703 continue;
704
705 if (r->ip_proto != rule->ip_proto)
706 continue;
707
708 if (r->proto != rule->proto)
709 continue;
710
711 if (!fib_rule_port_range_compare(&r->sport_range,
712 &rule->sport_range))
713 continue;
714
715 if (!fib_rule_port_range_compare(&r->dport_range,
716 &rule->dport_range))
717 continue;
718
719 if (!ops->compare(r, frh, tb))
720 continue;
721 return 1;
722 }
723 return 0;
724 }
725
726 int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
727 struct netlink_ext_ack *extack)
728 {
729 struct net *net = sock_net(skb->sk);
730 struct fib_rule_hdr *frh = nlmsg_data(nlh);
731 struct fib_rules_ops *ops = NULL;
732 struct fib_rule *rule = NULL, *r, *last = NULL;
733 struct nlattr *tb[FRA_MAX + 1];
734 int err = -EINVAL, unresolved = 0;
735 bool user_priority = false;
736
737 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
738 NL_SET_ERR_MSG(extack, "Invalid msg length");
739 goto errout;
740 }
741
742 ops = lookup_rules_ops(net, frh->family);
743 if (!ops) {
744 err = -EAFNOSUPPORT;
745 NL_SET_ERR_MSG(extack, "Rule family not supported");
746 goto errout;
747 }
748
749 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack);
750 if (err < 0) {
751 NL_SET_ERR_MSG(extack, "Error parsing msg");
752 goto errout;
753 }
754
755 err = fib_nl2rule(skb, nlh, extack, ops, tb, &rule, &user_priority);
756 if (err)
757 goto errout;
758
759 if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
760 rule_exists(ops, frh, tb, rule)) {
761 err = -EEXIST;
762 goto errout_free;
763 }
764
765 err = ops->configure(rule, skb, frh, tb, extack);
766 if (err < 0)
767 goto errout_free;
768
769 err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops,
770 extack);
771 if (err < 0)
772 goto errout_free;
773
774 list_for_each_entry(r, &ops->rules_list, list) {
775 if (r->pref == rule->target) {
776 RCU_INIT_POINTER(rule->ctarget, r);
777 break;
778 }
779 }
780
781 if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
782 unresolved = 1;
783
784 list_for_each_entry(r, &ops->rules_list, list) {
785 if (r->pref > rule->pref)
786 break;
787 last = r;
788 }
789
790 if (last)
791 list_add_rcu(&rule->list, &last->list);
792 else
793 list_add_rcu(&rule->list, &ops->rules_list);
794
795 if (ops->unresolved_rules) {
796 /*
797 * There are unresolved goto rules in the list, check if
798 * any of them are pointing to this new rule.
799 */
800 list_for_each_entry(r, &ops->rules_list, list) {
801 if (r->action == FR_ACT_GOTO &&
802 r->target == rule->pref &&
803 rtnl_dereference(r->ctarget) == NULL) {
804 rcu_assign_pointer(r->ctarget, rule);
805 if (--ops->unresolved_rules == 0)
806 break;
807 }
808 }
809 }
810
811 if (rule->action == FR_ACT_GOTO)
812 ops->nr_goto_rules++;
813
814 if (unresolved)
815 ops->unresolved_rules++;
816
817 if (rule->tun_id)
818 ip_tunnel_need_metadata();
819
820 notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
821 flush_route_cache(ops);
822 rules_ops_put(ops);
823 return 0;
824
825 errout_free:
826 kfree(rule);
827 errout:
828 rules_ops_put(ops);
829 return err;
830 }
831 EXPORT_SYMBOL_GPL(fib_nl_newrule);
832
833 int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
834 struct netlink_ext_ack *extack)
835 {
836 struct net *net = sock_net(skb->sk);
837 struct fib_rule_hdr *frh = nlmsg_data(nlh);
838 struct fib_rules_ops *ops = NULL;
839 struct fib_rule *rule = NULL, *r, *nlrule = NULL;
840 struct nlattr *tb[FRA_MAX+1];
841 int err = -EINVAL;
842 bool user_priority = false;
843
844 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
845 NL_SET_ERR_MSG(extack, "Invalid msg length");
846 goto errout;
847 }
848
849 ops = lookup_rules_ops(net, frh->family);
850 if (ops == NULL) {
851 err = -EAFNOSUPPORT;
852 NL_SET_ERR_MSG(extack, "Rule family not supported");
853 goto errout;
854 }
855
856 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack);
857 if (err < 0) {
858 NL_SET_ERR_MSG(extack, "Error parsing msg");
859 goto errout;
860 }
861
862 err = fib_nl2rule(skb, nlh, extack, ops, tb, &nlrule, &user_priority);
863 if (err)
864 goto errout;
865
866 rule = rule_find(ops, frh, tb, nlrule, user_priority);
867 if (!rule) {
868 err = -ENOENT;
869 goto errout;
870 }
871
872 if (rule->flags & FIB_RULE_PERMANENT) {
873 err = -EPERM;
874 goto errout;
875 }
876
877 if (ops->delete) {
878 err = ops->delete(rule);
879 if (err)
880 goto errout;
881 }
882
883 if (rule->tun_id)
884 ip_tunnel_unneed_metadata();
885
886 list_del_rcu(&rule->list);
887
888 if (rule->action == FR_ACT_GOTO) {
889 ops->nr_goto_rules--;
890 if (rtnl_dereference(rule->ctarget) == NULL)
891 ops->unresolved_rules--;
892 }
893
894 /*
895 * Check if this rule is a target to any of them. If so,
896 * adjust to the next one with the same preference or
897 * disable them. As this operation is eventually very
898 * expensive, it is only performed if goto rules, except
899 * current if it is goto rule, have actually been added.
900 */
901 if (ops->nr_goto_rules > 0) {
902 struct fib_rule *n;
903
904 n = list_next_entry(rule, list);
905 if (&n->list == &ops->rules_list || n->pref != rule->pref)
906 n = NULL;
907 list_for_each_entry(r, &ops->rules_list, list) {
908 if (rtnl_dereference(r->ctarget) != rule)
909 continue;
910 rcu_assign_pointer(r->ctarget, n);
911 if (!n)
912 ops->unresolved_rules++;
913 }
914 }
915
916 call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops,
917 NULL);
918 notify_rule_change(RTM_DELRULE, rule, ops, nlh,
919 NETLINK_CB(skb).portid);
920 fib_rule_put(rule);
921 flush_route_cache(ops);
922 rules_ops_put(ops);
923 kfree(nlrule);
924 return 0;
925
926 errout:
927 kfree(nlrule);
928 rules_ops_put(ops);
929 return err;
930 }
931 EXPORT_SYMBOL_GPL(fib_nl_delrule);
932
933 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
934 struct fib_rule *rule)
935 {
936 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
937 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
938 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
939 + nla_total_size(4) /* FRA_PRIORITY */
940 + nla_total_size(4) /* FRA_TABLE */
941 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
942 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
943 + nla_total_size(4) /* FRA_FWMARK */
944 + nla_total_size(4) /* FRA_FWMASK */
945 + nla_total_size_64bit(8) /* FRA_TUN_ID */
946 + nla_total_size(sizeof(struct fib_kuid_range))
947 + nla_total_size(1) /* FRA_PROTOCOL */
948 + nla_total_size(1) /* FRA_IP_PROTO */
949 + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */
950 + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */
951
952 if (ops->nlmsg_payload)
953 payload += ops->nlmsg_payload(rule);
954
955 return payload;
956 }
957
958 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
959 u32 pid, u32 seq, int type, int flags,
960 struct fib_rules_ops *ops)
961 {
962 struct nlmsghdr *nlh;
963 struct fib_rule_hdr *frh;
964
965 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
966 if (nlh == NULL)
967 return -EMSGSIZE;
968
969 frh = nlmsg_data(nlh);
970 frh->family = ops->family;
971 frh->table = rule->table;
972 if (nla_put_u32(skb, FRA_TABLE, rule->table))
973 goto nla_put_failure;
974 if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
975 goto nla_put_failure;
976 frh->res1 = 0;
977 frh->res2 = 0;
978 frh->action = rule->action;
979 frh->flags = rule->flags;
980
981 if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto))
982 goto nla_put_failure;
983
984 if (rule->action == FR_ACT_GOTO &&
985 rcu_access_pointer(rule->ctarget) == NULL)
986 frh->flags |= FIB_RULE_UNRESOLVED;
987
988 if (rule->iifname[0]) {
989 if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
990 goto nla_put_failure;
991 if (rule->iifindex == -1)
992 frh->flags |= FIB_RULE_IIF_DETACHED;
993 }
994
995 if (rule->oifname[0]) {
996 if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
997 goto nla_put_failure;
998 if (rule->oifindex == -1)
999 frh->flags |= FIB_RULE_OIF_DETACHED;
1000 }
1001
1002 if ((rule->pref &&
1003 nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
1004 (rule->mark &&
1005 nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
1006 ((rule->mark_mask || rule->mark) &&
1007 nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
1008 (rule->target &&
1009 nla_put_u32(skb, FRA_GOTO, rule->target)) ||
1010 (rule->tun_id &&
1011 nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) ||
1012 (rule->l3mdev &&
1013 nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) ||
1014 (uid_range_set(&rule->uid_range) &&
1015 nla_put_uid_range(skb, &rule->uid_range)) ||
1016 (fib_rule_port_range_set(&rule->sport_range) &&
1017 nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) ||
1018 (fib_rule_port_range_set(&rule->dport_range) &&
1019 nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) ||
1020 (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto)))
1021 goto nla_put_failure;
1022
1023 if (rule->suppress_ifgroup != -1) {
1024 if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
1025 goto nla_put_failure;
1026 }
1027
1028 if (ops->fill(rule, skb, frh) < 0)
1029 goto nla_put_failure;
1030
1031 nlmsg_end(skb, nlh);
1032 return 0;
1033
1034 nla_put_failure:
1035 nlmsg_cancel(skb, nlh);
1036 return -EMSGSIZE;
1037 }
1038
1039 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
1040 struct fib_rules_ops *ops)
1041 {
1042 int idx = 0;
1043 struct fib_rule *rule;
1044 int err = 0;
1045
1046 rcu_read_lock();
1047 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
1048 if (idx < cb->args[1])
1049 goto skip;
1050
1051 err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
1052 cb->nlh->nlmsg_seq, RTM_NEWRULE,
1053 NLM_F_MULTI, ops);
1054 if (err)
1055 break;
1056 skip:
1057 idx++;
1058 }
1059 rcu_read_unlock();
1060 cb->args[1] = idx;
1061 rules_ops_put(ops);
1062
1063 return err;
1064 }
1065
1066 static int fib_valid_dumprule_req(const struct nlmsghdr *nlh,
1067 struct netlink_ext_ack *extack)
1068 {
1069 struct fib_rule_hdr *frh;
1070
1071 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
1072 NL_SET_ERR_MSG(extack, "Invalid header for fib rule dump request");
1073 return -EINVAL;
1074 }
1075
1076 frh = nlmsg_data(nlh);
1077 if (frh->dst_len || frh->src_len || frh->tos || frh->table ||
1078 frh->res1 || frh->res2 || frh->action || frh->flags) {
1079 NL_SET_ERR_MSG(extack,
1080 "Invalid values in header for fib rule dump request");
1081 return -EINVAL;
1082 }
1083
1084 if (nlmsg_attrlen(nlh, sizeof(*frh))) {
1085 NL_SET_ERR_MSG(extack, "Invalid data after header in fib rule dump request");
1086 return -EINVAL;
1087 }
1088
1089 return 0;
1090 }
1091
1092 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
1093 {
1094 const struct nlmsghdr *nlh = cb->nlh;
1095 struct net *net = sock_net(skb->sk);
1096 struct fib_rules_ops *ops;
1097 int idx = 0, family;
1098
1099 if (cb->strict_check) {
1100 int err = fib_valid_dumprule_req(nlh, cb->extack);
1101
1102 if (err < 0)
1103 return err;
1104 }
1105
1106 family = rtnl_msg_family(nlh);
1107 if (family != AF_UNSPEC) {
1108 /* Protocol specific dump request */
1109 ops = lookup_rules_ops(net, family);
1110 if (ops == NULL)
1111 return -EAFNOSUPPORT;
1112
1113 dump_rules(skb, cb, ops);
1114
1115 return skb->len;
1116 }
1117
1118 rcu_read_lock();
1119 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
1120 if (idx < cb->args[0] || !try_module_get(ops->owner))
1121 goto skip;
1122
1123 if (dump_rules(skb, cb, ops) < 0)
1124 break;
1125
1126 cb->args[1] = 0;
1127 skip:
1128 idx++;
1129 }
1130 rcu_read_unlock();
1131 cb->args[0] = idx;
1132
1133 return skb->len;
1134 }
1135
1136 static void notify_rule_change(int event, struct fib_rule *rule,
1137 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
1138 u32 pid)
1139 {
1140 struct net *net;
1141 struct sk_buff *skb;
1142 int err = -ENOBUFS;
1143
1144 net = ops->fro_net;
1145 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
1146 if (skb == NULL)
1147 goto errout;
1148
1149 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
1150 if (err < 0) {
1151 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
1152 WARN_ON(err == -EMSGSIZE);
1153 kfree_skb(skb);
1154 goto errout;
1155 }
1156
1157 rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
1158 return;
1159 errout:
1160 if (err < 0)
1161 rtnl_set_sk_err(net, ops->nlgroup, err);
1162 }
1163
1164 static void attach_rules(struct list_head *rules, struct net_device *dev)
1165 {
1166 struct fib_rule *rule;
1167
1168 list_for_each_entry(rule, rules, list) {
1169 if (rule->iifindex == -1 &&
1170 strcmp(dev->name, rule->iifname) == 0)
1171 rule->iifindex = dev->ifindex;
1172 if (rule->oifindex == -1 &&
1173 strcmp(dev->name, rule->oifname) == 0)
1174 rule->oifindex = dev->ifindex;
1175 }
1176 }
1177
1178 static void detach_rules(struct list_head *rules, struct net_device *dev)
1179 {
1180 struct fib_rule *rule;
1181
1182 list_for_each_entry(rule, rules, list) {
1183 if (rule->iifindex == dev->ifindex)
1184 rule->iifindex = -1;
1185 if (rule->oifindex == dev->ifindex)
1186 rule->oifindex = -1;
1187 }
1188 }
1189
1190
1191 static int fib_rules_event(struct notifier_block *this, unsigned long event,
1192 void *ptr)
1193 {
1194 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1195 struct net *net = dev_net(dev);
1196 struct fib_rules_ops *ops;
1197
1198 ASSERT_RTNL();
1199
1200 switch (event) {
1201 case NETDEV_REGISTER:
1202 list_for_each_entry(ops, &net->rules_ops, list)
1203 attach_rules(&ops->rules_list, dev);
1204 break;
1205
1206 case NETDEV_CHANGENAME:
1207 list_for_each_entry(ops, &net->rules_ops, list) {
1208 detach_rules(&ops->rules_list, dev);
1209 attach_rules(&ops->rules_list, dev);
1210 }
1211 break;
1212
1213 case NETDEV_UNREGISTER:
1214 list_for_each_entry(ops, &net->rules_ops, list)
1215 detach_rules(&ops->rules_list, dev);
1216 break;
1217 }
1218
1219 return NOTIFY_DONE;
1220 }
1221
1222 static struct notifier_block fib_rules_notifier = {
1223 .notifier_call = fib_rules_event,
1224 };
1225
1226 static int __net_init fib_rules_net_init(struct net *net)
1227 {
1228 INIT_LIST_HEAD(&net->rules_ops);
1229 spin_lock_init(&net->rules_mod_lock);
1230 return 0;
1231 }
1232
1233 static void __net_exit fib_rules_net_exit(struct net *net)
1234 {
1235 WARN_ON_ONCE(!list_empty(&net->rules_ops));
1236 }
1237
1238 static struct pernet_operations fib_rules_net_ops = {
1239 .init = fib_rules_net_init,
1240 .exit = fib_rules_net_exit,
1241 };
1242
1243 static int __init fib_rules_init(void)
1244 {
1245 int err;
1246 rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, 0);
1247 rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, 0);
1248 rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, 0);
1249
1250 err = register_pernet_subsys(&fib_rules_net_ops);
1251 if (err < 0)
1252 goto fail;
1253
1254 err = register_netdevice_notifier(&fib_rules_notifier);
1255 if (err < 0)
1256 goto fail_unregister;
1257
1258 return 0;
1259
1260 fail_unregister:
1261 unregister_pernet_subsys(&fib_rules_net_ops);
1262 fail:
1263 rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
1264 rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
1265 rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
1266 return err;
1267 }
1268
1269 subsys_initcall(fib_rules_init);
Linux with added FPC-III support