1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * net/core/fib_rules.c Generic Routing Rules
4 *
5 * Authors: Thomas Graf <tgraf@suug.ch>
6 */
7
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/slab.h>
11 #include <linux/list.h>
12 #include <linux/module.h>
13 #include <net/net_namespace.h>
14 #include <net/inet_dscp.h>
15 #include <net/sock.h>
16 #include <net/fib_rules.h>
17 #include <net/ip_tunnels.h>
18 #include <linux/indirect_call_wrapper.h>
19
20 #if defined(CONFIG_IPV6) && defined(CONFIG_IPV6_MULTIPLE_TABLES)
21 #ifdef CONFIG_IP_MULTIPLE_TABLES
22 #define INDIRECT_CALL_MT(f, f2, f1, ...) \
23 INDIRECT_CALL_INET(f, f2, f1, __VA_ARGS__)
24 #else
25 #define INDIRECT_CALL_MT(f, f2, f1, ...) INDIRECT_CALL_1(f, f2, __VA_ARGS__)
26 #endif
27 #elif defined(CONFIG_IP_MULTIPLE_TABLES)
28 #define INDIRECT_CALL_MT(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__)
29 #else
30 #define INDIRECT_CALL_MT(f, f2, f1, ...) f(__VA_ARGS__)
31 #endif
32
33 static const struct fib_kuid_range fib_kuid_range_unset = {
34 KUIDT_INIT(0),
35 KUIDT_INIT(~0),
36 };
37
fib_rule_matchall(const struct fib_rule * rule)38 bool fib_rule_matchall(const struct fib_rule *rule)
39 {
40 if (READ_ONCE(rule->iifindex) || READ_ONCE(rule->oifindex) ||
41 rule->mark || rule->tun_id || rule->flags)
42 return false;
43 if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1)
44 return false;
45 if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) ||
46 !uid_eq(rule->uid_range.end, fib_kuid_range_unset.end))
47 return false;
48 if (fib_rule_port_range_set(&rule->sport_range))
49 return false;
50 if (fib_rule_port_range_set(&rule->dport_range))
51 return false;
52 return true;
53 }
54 EXPORT_SYMBOL_GPL(fib_rule_matchall);
55
fib_default_rule_add(struct fib_rules_ops * ops,u32 pref,u32 table)56 int fib_default_rule_add(struct fib_rules_ops *ops,
57 u32 pref, u32 table)
58 {
59 struct fib_rule *r;
60
61 r = kzalloc(ops->rule_size, GFP_KERNEL_ACCOUNT);
62 if (r == NULL)
63 return -ENOMEM;
64
65 refcount_set(&r->refcnt, 1);
66 r->action = FR_ACT_TO_TBL;
67 r->pref = pref;
68 r->table = table;
69 r->proto = RTPROT_KERNEL;
70 r->fr_net = ops->fro_net;
71 r->uid_range = fib_kuid_range_unset;
72
73 r->suppress_prefixlen = -1;
74 r->suppress_ifgroup = -1;
75
76 /* The lock is not required here, the list in unreachable
77 * at the moment this function is called */
78 list_add_tail(&r->list, &ops->rules_list);
79 return 0;
80 }
81 EXPORT_SYMBOL(fib_default_rule_add);
82
fib_default_rule_pref(struct fib_rules_ops * ops)83 static u32 fib_default_rule_pref(struct fib_rules_ops *ops)
84 {
85 struct list_head *pos;
86 struct fib_rule *rule;
87
88 if (!list_empty(&ops->rules_list)) {
89 pos = ops->rules_list.next;
90 if (pos->next != &ops->rules_list) {
91 rule = list_entry(pos->next, struct fib_rule, list);
92 if (rule->pref)
93 return rule->pref - 1;
94 }
95 }
96
97 return 0;
98 }
99
100 static void notify_rule_change(int event, struct fib_rule *rule,
101 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
102 u32 pid);
103
lookup_rules_ops(const struct net * net,int family)104 static struct fib_rules_ops *lookup_rules_ops(const struct net *net,
105 int family)
106 {
107 struct fib_rules_ops *ops;
108
109 rcu_read_lock();
110 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
111 if (ops->family == family) {
112 if (!try_module_get(ops->owner))
113 ops = NULL;
114 rcu_read_unlock();
115 return ops;
116 }
117 }
118 rcu_read_unlock();
119
120 return NULL;
121 }
122
rules_ops_put(struct fib_rules_ops * ops)123 static void rules_ops_put(struct fib_rules_ops *ops)
124 {
125 if (ops)
126 module_put(ops->owner);
127 }
128
flush_route_cache(struct fib_rules_ops * ops)129 static void flush_route_cache(struct fib_rules_ops *ops)
130 {
131 if (ops->flush_cache)
132 ops->flush_cache(ops);
133 }
134
__fib_rules_register(struct fib_rules_ops * ops)135 static int __fib_rules_register(struct fib_rules_ops *ops)
136 {
137 int err = -EEXIST;
138 struct fib_rules_ops *o;
139 struct net *net;
140
141 net = ops->fro_net;
142
143 if (ops->rule_size < sizeof(struct fib_rule))
144 return -EINVAL;
145
146 if (ops->match == NULL || ops->configure == NULL ||
147 ops->compare == NULL || ops->fill == NULL ||
148 ops->action == NULL)
149 return -EINVAL;
150
151 spin_lock(&net->rules_mod_lock);
152 list_for_each_entry(o, &net->rules_ops, list)
153 if (ops->family == o->family)
154 goto errout;
155
156 list_add_tail_rcu(&ops->list, &net->rules_ops);
157 err = 0;
158 errout:
159 spin_unlock(&net->rules_mod_lock);
160
161 return err;
162 }
163
164 struct fib_rules_ops *
fib_rules_register(const struct fib_rules_ops * tmpl,struct net * net)165 fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
166 {
167 struct fib_rules_ops *ops;
168 int err;
169
170 ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
171 if (ops == NULL)
172 return ERR_PTR(-ENOMEM);
173
174 INIT_LIST_HEAD(&ops->rules_list);
175 ops->fro_net = net;
176
177 err = __fib_rules_register(ops);
178 if (err) {
179 kfree(ops);
180 ops = ERR_PTR(err);
181 }
182
183 return ops;
184 }
185 EXPORT_SYMBOL_GPL(fib_rules_register);
186
fib_rules_cleanup_ops(struct fib_rules_ops * ops)187 static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
188 {
189 struct fib_rule *rule, *tmp;
190
191 list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
192 list_del_rcu(&rule->list);
193 if (ops->delete)
194 ops->delete(rule);
195 fib_rule_put(rule);
196 }
197 }
198
fib_rules_unregister(struct fib_rules_ops * ops)199 void fib_rules_unregister(struct fib_rules_ops *ops)
200 {
201 struct net *net = ops->fro_net;
202
203 spin_lock(&net->rules_mod_lock);
204 list_del_rcu(&ops->list);
205 spin_unlock(&net->rules_mod_lock);
206
207 fib_rules_cleanup_ops(ops);
208 kfree_rcu(ops, rcu);
209 }
210 EXPORT_SYMBOL_GPL(fib_rules_unregister);
211
uid_range_set(struct fib_kuid_range * range)212 static int uid_range_set(struct fib_kuid_range *range)
213 {
214 return uid_valid(range->start) && uid_valid(range->end);
215 }
216
nla_get_kuid_range(struct nlattr ** tb)217 static struct fib_kuid_range nla_get_kuid_range(struct nlattr **tb)
218 {
219 struct fib_rule_uid_range *in;
220 struct fib_kuid_range out;
221
222 in = (struct fib_rule_uid_range *)nla_data(tb[FRA_UID_RANGE]);
223
224 out.start = make_kuid(current_user_ns(), in->start);
225 out.end = make_kuid(current_user_ns(), in->end);
226
227 return out;
228 }
229
nla_put_uid_range(struct sk_buff * skb,struct fib_kuid_range * range)230 static int nla_put_uid_range(struct sk_buff *skb, struct fib_kuid_range *range)
231 {
232 struct fib_rule_uid_range out = {
233 from_kuid_munged(current_user_ns(), range->start),
234 from_kuid_munged(current_user_ns(), range->end)
235 };
236
237 return nla_put(skb, FRA_UID_RANGE, sizeof(out), &out);
238 }
239
nla_get_port_range(struct nlattr * pattr,struct fib_rule_port_range * port_range)240 static int nla_get_port_range(struct nlattr *pattr,
241 struct fib_rule_port_range *port_range)
242 {
243 const struct fib_rule_port_range *pr = nla_data(pattr);
244
245 if (!fib_rule_port_range_valid(pr))
246 return -EINVAL;
247
248 port_range->start = pr->start;
249 port_range->end = pr->end;
250
251 return 0;
252 }
253
nla_put_port_range(struct sk_buff * skb,int attrtype,struct fib_rule_port_range * range)254 static int nla_put_port_range(struct sk_buff *skb, int attrtype,
255 struct fib_rule_port_range *range)
256 {
257 return nla_put(skb, attrtype, sizeof(*range), range);
258 }
259
fib_rule_iif_match(const struct fib_rule * rule,int iifindex,const struct flowi * fl)260 static bool fib_rule_iif_match(const struct fib_rule *rule, int iifindex,
261 const struct flowi *fl)
262 {
263 u8 iif_is_l3_master = READ_ONCE(rule->iif_is_l3_master);
264
265 return iif_is_l3_master ? l3mdev_fib_rule_iif_match(fl, iifindex) :
266 fl->flowi_iif == iifindex;
267 }
268
fib_rule_oif_match(const struct fib_rule * rule,int oifindex,const struct flowi * fl)269 static bool fib_rule_oif_match(const struct fib_rule *rule, int oifindex,
270 const struct flowi *fl)
271 {
272 u8 oif_is_l3_master = READ_ONCE(rule->oif_is_l3_master);
273
274 return oif_is_l3_master ? l3mdev_fib_rule_oif_match(fl, oifindex) :
275 fl->flowi_oif == oifindex;
276 }
277
fib_rule_match(struct fib_rule * rule,struct fib_rules_ops * ops,struct flowi * fl,int flags,struct fib_lookup_arg * arg)278 static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
279 struct flowi *fl, int flags,
280 struct fib_lookup_arg *arg)
281 {
282 int iifindex, oifindex, ret = 0;
283
284 iifindex = READ_ONCE(rule->iifindex);
285 if (iifindex && !fib_rule_iif_match(rule, iifindex, fl))
286 goto out;
287
288 oifindex = READ_ONCE(rule->oifindex);
289 if (oifindex && !fib_rule_oif_match(rule, oifindex, fl))
290 goto out;
291
292 if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
293 goto out;
294
295 if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id))
296 goto out;
297
298 if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg))
299 goto out;
300
301 if (uid_lt(fl->flowi_uid, rule->uid_range.start) ||
302 uid_gt(fl->flowi_uid, rule->uid_range.end))
303 goto out;
304
305 ret = INDIRECT_CALL_MT(ops->match,
306 fib6_rule_match,
307 fib4_rule_match,
308 rule, fl, flags);
309 out:
310 return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
311 }
312
fib_rules_lookup(struct fib_rules_ops * ops,struct flowi * fl,int flags,struct fib_lookup_arg * arg)313 int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
314 int flags, struct fib_lookup_arg *arg)
315 {
316 struct fib_rule *rule;
317 int err;
318
319 rcu_read_lock();
320
321 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
322 jumped:
323 if (!fib_rule_match(rule, ops, fl, flags, arg))
324 continue;
325
326 if (rule->action == FR_ACT_GOTO) {
327 struct fib_rule *target;
328
329 target = rcu_dereference(rule->ctarget);
330 if (target == NULL) {
331 continue;
332 } else {
333 rule = target;
334 goto jumped;
335 }
336 } else if (rule->action == FR_ACT_NOP)
337 continue;
338 else
339 err = INDIRECT_CALL_MT(ops->action,
340 fib6_rule_action,
341 fib4_rule_action,
342 rule, fl, flags, arg);
343
344 if (!err && ops->suppress && INDIRECT_CALL_MT(ops->suppress,
345 fib6_rule_suppress,
346 fib4_rule_suppress,
347 rule, flags, arg))
348 continue;
349
350 if (err != -EAGAIN) {
351 if ((arg->flags & FIB_LOOKUP_NOREF) ||
352 likely(refcount_inc_not_zero(&rule->refcnt))) {
353 arg->rule = rule;
354 goto out;
355 }
356 break;
357 }
358 }
359
360 err = -ESRCH;
361 out:
362 rcu_read_unlock();
363
364 return err;
365 }
366 EXPORT_SYMBOL_GPL(fib_rules_lookup);
367
call_fib_rule_notifier(struct notifier_block * nb,enum fib_event_type event_type,struct fib_rule * rule,int family,struct netlink_ext_ack * extack)368 static int call_fib_rule_notifier(struct notifier_block *nb,
369 enum fib_event_type event_type,
370 struct fib_rule *rule, int family,
371 struct netlink_ext_ack *extack)
372 {
373 struct fib_rule_notifier_info info = {
374 .info.family = family,
375 .info.extack = extack,
376 .rule = rule,
377 };
378
379 return call_fib_notifier(nb, event_type, &info.info);
380 }
381
call_fib_rule_notifiers(struct net * net,enum fib_event_type event_type,struct fib_rule * rule,struct fib_rules_ops * ops,struct netlink_ext_ack * extack)382 static int call_fib_rule_notifiers(struct net *net,
383 enum fib_event_type event_type,
384 struct fib_rule *rule,
385 struct fib_rules_ops *ops,
386 struct netlink_ext_ack *extack)
387 {
388 struct fib_rule_notifier_info info = {
389 .info.family = ops->family,
390 .info.extack = extack,
391 .rule = rule,
392 };
393
394 ASSERT_RTNL_NET(net);
395
396 /* Paired with READ_ONCE() in fib_rules_seq() */
397 WRITE_ONCE(ops->fib_rules_seq, ops->fib_rules_seq + 1);
398 return call_fib_notifiers(net, event_type, &info.info);
399 }
400
401 /* Called with rcu_read_lock() */
fib_rules_dump(struct net * net,struct notifier_block * nb,int family,struct netlink_ext_ack * extack)402 int fib_rules_dump(struct net *net, struct notifier_block *nb, int family,
403 struct netlink_ext_ack *extack)
404 {
405 struct fib_rules_ops *ops;
406 struct fib_rule *rule;
407 int err = 0;
408
409 ops = lookup_rules_ops(net, family);
410 if (!ops)
411 return -EAFNOSUPPORT;
412 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
413 err = call_fib_rule_notifier(nb, FIB_EVENT_RULE_ADD,
414 rule, family, extack);
415 if (err)
416 break;
417 }
418 rules_ops_put(ops);
419
420 return err;
421 }
422 EXPORT_SYMBOL_GPL(fib_rules_dump);
423
fib_rules_seq_read(const struct net * net,int family)424 unsigned int fib_rules_seq_read(const struct net *net, int family)
425 {
426 unsigned int fib_rules_seq;
427 struct fib_rules_ops *ops;
428
429 ops = lookup_rules_ops(net, family);
430 if (!ops)
431 return 0;
432 /* Paired with WRITE_ONCE() in call_fib_rule_notifiers() */
433 fib_rules_seq = READ_ONCE(ops->fib_rules_seq);
434 rules_ops_put(ops);
435
436 return fib_rules_seq;
437 }
438 EXPORT_SYMBOL_GPL(fib_rules_seq_read);
439
rule_find(struct fib_rules_ops * ops,struct fib_rule_hdr * frh,struct nlattr ** tb,struct fib_rule * rule,bool user_priority)440 static struct fib_rule *rule_find(struct fib_rules_ops *ops,
441 struct fib_rule_hdr *frh,
442 struct nlattr **tb,
443 struct fib_rule *rule,
444 bool user_priority)
445 {
446 struct fib_rule *r;
447
448 list_for_each_entry(r, &ops->rules_list, list) {
449 if (rule->action && r->action != rule->action)
450 continue;
451
452 if (rule->table && r->table != rule->table)
453 continue;
454
455 if (user_priority && r->pref != rule->pref)
456 continue;
457
458 if (rule->iifname[0] &&
459 memcmp(r->iifname, rule->iifname, IFNAMSIZ))
460 continue;
461
462 if (rule->oifname[0] &&
463 memcmp(r->oifname, rule->oifname, IFNAMSIZ))
464 continue;
465
466 if (rule->mark && r->mark != rule->mark)
467 continue;
468
469 if (rule->suppress_ifgroup != -1 &&
470 r->suppress_ifgroup != rule->suppress_ifgroup)
471 continue;
472
473 if (rule->suppress_prefixlen != -1 &&
474 r->suppress_prefixlen != rule->suppress_prefixlen)
475 continue;
476
477 if (rule->mark_mask && r->mark_mask != rule->mark_mask)
478 continue;
479
480 if (rule->tun_id && r->tun_id != rule->tun_id)
481 continue;
482
483 if (rule->l3mdev && r->l3mdev != rule->l3mdev)
484 continue;
485
486 if (uid_range_set(&rule->uid_range) &&
487 (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
488 !uid_eq(r->uid_range.end, rule->uid_range.end)))
489 continue;
490
491 if (rule->ip_proto && r->ip_proto != rule->ip_proto)
492 continue;
493
494 if (rule->proto && r->proto != rule->proto)
495 continue;
496
497 if (fib_rule_port_range_set(&rule->sport_range) &&
498 !fib_rule_port_range_compare(&r->sport_range,
499 &rule->sport_range))
500 continue;
501
502 if (rule->sport_mask && r->sport_mask != rule->sport_mask)
503 continue;
504
505 if (fib_rule_port_range_set(&rule->dport_range) &&
506 !fib_rule_port_range_compare(&r->dport_range,
507 &rule->dport_range))
508 continue;
509
510 if (rule->dport_mask && r->dport_mask != rule->dport_mask)
511 continue;
512
513 if (!ops->compare(r, frh, tb))
514 continue;
515 return r;
516 }
517
518 return NULL;
519 }
520
521 #ifdef CONFIG_NET_L3_MASTER_DEV
fib_nl2rule_l3mdev(struct nlattr * nla,struct fib_rule * nlrule,struct netlink_ext_ack * extack)522 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
523 struct netlink_ext_ack *extack)
524 {
525 nlrule->l3mdev = nla_get_u8(nla);
526 if (nlrule->l3mdev != 1) {
527 NL_SET_ERR_MSG(extack, "Invalid l3mdev attribute");
528 return -1;
529 }
530
531 return 0;
532 }
533 #else
fib_nl2rule_l3mdev(struct nlattr * nla,struct fib_rule * nlrule,struct netlink_ext_ack * extack)534 static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule,
535 struct netlink_ext_ack *extack)
536 {
537 NL_SET_ERR_MSG(extack, "l3mdev support is not enabled in kernel");
538 return -1;
539 }
540 #endif
541
fib_nl2rule_port_mask(const struct nlattr * mask_attr,const struct fib_rule_port_range * range,u16 * port_mask,struct netlink_ext_ack * extack)542 static int fib_nl2rule_port_mask(const struct nlattr *mask_attr,
543 const struct fib_rule_port_range *range,
544 u16 *port_mask,
545 struct netlink_ext_ack *extack)
546 {
547 if (!fib_rule_port_range_valid(range)) {
548 NL_SET_ERR_MSG_ATTR(extack, mask_attr,
549 "Cannot specify port mask without port value");
550 return -EINVAL;
551 }
552
553 if (fib_rule_port_is_range(range)) {
554 NL_SET_ERR_MSG_ATTR(extack, mask_attr,
555 "Cannot specify port mask for port range");
556 return -EINVAL;
557 }
558
559 if (range->start & ~nla_get_u16(mask_attr)) {
560 NL_SET_ERR_MSG_ATTR(extack, mask_attr, "Invalid port mask");
561 return -EINVAL;
562 }
563
564 *port_mask = nla_get_u16(mask_attr);
565
566 return 0;
567 }
568
fib_nl2rule(struct net * net,struct nlmsghdr * nlh,struct netlink_ext_ack * extack,struct fib_rules_ops * ops,struct nlattr * tb[],struct fib_rule ** rule,bool * user_priority)569 static int fib_nl2rule(struct net *net, struct nlmsghdr *nlh,
570 struct netlink_ext_ack *extack,
571 struct fib_rules_ops *ops,
572 struct nlattr *tb[],
573 struct fib_rule **rule,
574 bool *user_priority)
575 {
576 struct fib_rule_hdr *frh = nlmsg_data(nlh);
577 struct fib_rule *nlrule = NULL;
578 int err = -EINVAL;
579
580 if (frh->src_len)
581 if (!tb[FRA_SRC] ||
582 frh->src_len > (ops->addr_size * 8) ||
583 nla_len(tb[FRA_SRC]) != ops->addr_size) {
584 NL_SET_ERR_MSG(extack, "Invalid source address");
585 goto errout;
586 }
587
588 if (frh->dst_len)
589 if (!tb[FRA_DST] ||
590 frh->dst_len > (ops->addr_size * 8) ||
591 nla_len(tb[FRA_DST]) != ops->addr_size) {
592 NL_SET_ERR_MSG(extack, "Invalid dst address");
593 goto errout;
594 }
595
596 nlrule = kzalloc(ops->rule_size, GFP_KERNEL_ACCOUNT);
597 if (!nlrule) {
598 err = -ENOMEM;
599 goto errout;
600 }
601 refcount_set(&nlrule->refcnt, 1);
602 nlrule->fr_net = net;
603
604 if (tb[FRA_PRIORITY]) {
605 nlrule->pref = nla_get_u32(tb[FRA_PRIORITY]);
606 *user_priority = true;
607 }
608
609 nlrule->proto = nla_get_u8_default(tb[FRA_PROTOCOL], RTPROT_UNSPEC);
610
611 if (tb[FRA_IIFNAME]) {
612 nlrule->iifindex = -1;
613 nla_strscpy(nlrule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
614 }
615
616 if (tb[FRA_OIFNAME]) {
617 nlrule->oifindex = -1;
618 nla_strscpy(nlrule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
619 }
620
621 if (tb[FRA_FWMARK]) {
622 nlrule->mark = nla_get_u32(tb[FRA_FWMARK]);
623 if (nlrule->mark)
624 /* compatibility: if the mark value is non-zero all bits
625 * are compared unless a mask is explicitly specified.
626 */
627 nlrule->mark_mask = 0xFFFFFFFF;
628 }
629
630 if (tb[FRA_FWMASK])
631 nlrule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
632
633 if (tb[FRA_TUN_ID])
634 nlrule->tun_id = nla_get_be64(tb[FRA_TUN_ID]);
635
636 if (tb[FRA_L3MDEV] &&
637 fib_nl2rule_l3mdev(tb[FRA_L3MDEV], nlrule, extack) < 0)
638 goto errout_free;
639
640 nlrule->action = frh->action;
641 nlrule->flags = frh->flags;
642 nlrule->table = frh_get_table(frh, tb);
643 if (tb[FRA_SUPPRESS_PREFIXLEN])
644 nlrule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
645 else
646 nlrule->suppress_prefixlen = -1;
647
648 if (tb[FRA_SUPPRESS_IFGROUP])
649 nlrule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
650 else
651 nlrule->suppress_ifgroup = -1;
652
653 if (tb[FRA_GOTO]) {
654 if (nlrule->action != FR_ACT_GOTO) {
655 NL_SET_ERR_MSG(extack, "Unexpected goto");
656 goto errout_free;
657 }
658
659 nlrule->target = nla_get_u32(tb[FRA_GOTO]);
660 } else if (nlrule->action == FR_ACT_GOTO) {
661 NL_SET_ERR_MSG(extack, "Missing goto target for action goto");
662 goto errout_free;
663 }
664
665 if (nlrule->l3mdev && nlrule->table) {
666 NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive");
667 goto errout_free;
668 }
669
670 if (tb[FRA_UID_RANGE]) {
671 if (current_user_ns() != net->user_ns) {
672 err = -EPERM;
673 NL_SET_ERR_MSG(extack, "No permission to set uid");
674 goto errout_free;
675 }
676
677 nlrule->uid_range = nla_get_kuid_range(tb);
678
679 if (!uid_range_set(&nlrule->uid_range) ||
680 !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) {
681 NL_SET_ERR_MSG(extack, "Invalid uid range");
682 goto errout_free;
683 }
684 } else {
685 nlrule->uid_range = fib_kuid_range_unset;
686 }
687
688 if (tb[FRA_IP_PROTO])
689 nlrule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]);
690
691 if (tb[FRA_SPORT_RANGE]) {
692 err = nla_get_port_range(tb[FRA_SPORT_RANGE],
693 &nlrule->sport_range);
694 if (err) {
695 NL_SET_ERR_MSG(extack, "Invalid sport range");
696 goto errout_free;
697 }
698 if (!fib_rule_port_is_range(&nlrule->sport_range))
699 nlrule->sport_mask = U16_MAX;
700 }
701
702 if (tb[FRA_SPORT_MASK]) {
703 err = fib_nl2rule_port_mask(tb[FRA_SPORT_MASK],
704 &nlrule->sport_range,
705 &nlrule->sport_mask, extack);
706 if (err)
707 goto errout_free;
708 }
709
710 if (tb[FRA_DPORT_RANGE]) {
711 err = nla_get_port_range(tb[FRA_DPORT_RANGE],
712 &nlrule->dport_range);
713 if (err) {
714 NL_SET_ERR_MSG(extack, "Invalid dport range");
715 goto errout_free;
716 }
717 if (!fib_rule_port_is_range(&nlrule->dport_range))
718 nlrule->dport_mask = U16_MAX;
719 }
720
721 if (tb[FRA_DPORT_MASK]) {
722 err = fib_nl2rule_port_mask(tb[FRA_DPORT_MASK],
723 &nlrule->dport_range,
724 &nlrule->dport_mask, extack);
725 if (err)
726 goto errout_free;
727 }
728
729 *rule = nlrule;
730
731 return 0;
732
733 errout_free:
734 kfree(nlrule);
735 errout:
736 return err;
737 }
738
fib_nl2rule_rtnl(struct fib_rule * nlrule,struct fib_rules_ops * ops,struct nlattr * tb[],struct netlink_ext_ack * extack)739 static int fib_nl2rule_rtnl(struct fib_rule *nlrule,
740 struct fib_rules_ops *ops,
741 struct nlattr *tb[],
742 struct netlink_ext_ack *extack)
743 {
744 if (!tb[FRA_PRIORITY])
745 nlrule->pref = fib_default_rule_pref(ops);
746
747 /* Backward jumps are prohibited to avoid endless loops */
748 if (tb[FRA_GOTO] && nlrule->target <= nlrule->pref) {
749 NL_SET_ERR_MSG(extack, "Backward goto not supported");
750 return -EINVAL;
751 }
752
753 if (tb[FRA_IIFNAME]) {
754 struct net_device *dev;
755
756 dev = __dev_get_by_name(nlrule->fr_net, nlrule->iifname);
757 if (dev) {
758 nlrule->iifindex = dev->ifindex;
759 nlrule->iif_is_l3_master = netif_is_l3_master(dev);
760 }
761 }
762
763 if (tb[FRA_OIFNAME]) {
764 struct net_device *dev;
765
766 dev = __dev_get_by_name(nlrule->fr_net, nlrule->oifname);
767 if (dev) {
768 nlrule->oifindex = dev->ifindex;
769 nlrule->oif_is_l3_master = netif_is_l3_master(dev);
770 }
771 }
772
773 return 0;
774 }
775
rule_exists(struct fib_rules_ops * ops,struct fib_rule_hdr * frh,struct nlattr ** tb,struct fib_rule * rule)776 static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh,
777 struct nlattr **tb, struct fib_rule *rule)
778 {
779 struct fib_rule *r;
780
781 list_for_each_entry(r, &ops->rules_list, list) {
782 if (r->action != rule->action)
783 continue;
784
785 if (r->table != rule->table)
786 continue;
787
788 if (r->pref != rule->pref)
789 continue;
790
791 if (memcmp(r->iifname, rule->iifname, IFNAMSIZ))
792 continue;
793
794 if (memcmp(r->oifname, rule->oifname, IFNAMSIZ))
795 continue;
796
797 if (r->mark != rule->mark)
798 continue;
799
800 if (r->suppress_ifgroup != rule->suppress_ifgroup)
801 continue;
802
803 if (r->suppress_prefixlen != rule->suppress_prefixlen)
804 continue;
805
806 if (r->mark_mask != rule->mark_mask)
807 continue;
808
809 if (r->tun_id != rule->tun_id)
810 continue;
811
812 if (r->l3mdev != rule->l3mdev)
813 continue;
814
815 if (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
816 !uid_eq(r->uid_range.end, rule->uid_range.end))
817 continue;
818
819 if (r->ip_proto != rule->ip_proto)
820 continue;
821
822 if (r->proto != rule->proto)
823 continue;
824
825 if (!fib_rule_port_range_compare(&r->sport_range,
826 &rule->sport_range))
827 continue;
828
829 if (r->sport_mask != rule->sport_mask)
830 continue;
831
832 if (!fib_rule_port_range_compare(&r->dport_range,
833 &rule->dport_range))
834 continue;
835
836 if (r->dport_mask != rule->dport_mask)
837 continue;
838
839 if (!ops->compare(r, frh, tb))
840 continue;
841 return 1;
842 }
843 return 0;
844 }
845
846 static const struct nla_policy fib_rule_policy[FRA_MAX + 1] = {
847 [FRA_UNSPEC] = { .strict_start_type = FRA_DPORT_RANGE + 1 },
848 [FRA_IIFNAME] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
849 [FRA_OIFNAME] = { .type = NLA_STRING, .len = IFNAMSIZ - 1 },
850 [FRA_PRIORITY] = { .type = NLA_U32 },
851 [FRA_FWMARK] = { .type = NLA_U32 },
852 [FRA_FLOW] = { .type = NLA_U32 },
853 [FRA_TUN_ID] = { .type = NLA_U64 },
854 [FRA_FWMASK] = { .type = NLA_U32 },
855 [FRA_TABLE] = { .type = NLA_U32 },
856 [FRA_SUPPRESS_PREFIXLEN] = { .type = NLA_U32 },
857 [FRA_SUPPRESS_IFGROUP] = { .type = NLA_U32 },
858 [FRA_GOTO] = { .type = NLA_U32 },
859 [FRA_L3MDEV] = { .type = NLA_U8 },
860 [FRA_UID_RANGE] = { .len = sizeof(struct fib_rule_uid_range) },
861 [FRA_PROTOCOL] = { .type = NLA_U8 },
862 [FRA_IP_PROTO] = { .type = NLA_U8 },
863 [FRA_SPORT_RANGE] = { .len = sizeof(struct fib_rule_port_range) },
864 [FRA_DPORT_RANGE] = { .len = sizeof(struct fib_rule_port_range) },
865 [FRA_DSCP] = NLA_POLICY_MAX(NLA_U8, INET_DSCP_MASK >> 2),
866 [FRA_FLOWLABEL] = { .type = NLA_BE32 },
867 [FRA_FLOWLABEL_MASK] = { .type = NLA_BE32 },
868 [FRA_SPORT_MASK] = { .type = NLA_U16 },
869 [FRA_DPORT_MASK] = { .type = NLA_U16 },
870 [FRA_DSCP_MASK] = NLA_POLICY_MASK(NLA_U8, INET_DSCP_MASK >> 2),
871 };
872
fib_newrule(struct net * net,struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack,bool rtnl_held)873 int fib_newrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh,
874 struct netlink_ext_ack *extack, bool rtnl_held)
875 {
876 struct fib_rule *rule = NULL, *r, *last = NULL;
877 struct fib_rule_hdr *frh = nlmsg_data(nlh);
878 int err = -EINVAL, unresolved = 0;
879 struct fib_rules_ops *ops = NULL;
880 struct nlattr *tb[FRA_MAX + 1];
881 bool user_priority = false;
882
883 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
884 NL_SET_ERR_MSG(extack, "Invalid msg length");
885 goto errout;
886 }
887
888 ops = lookup_rules_ops(net, frh->family);
889 if (!ops) {
890 err = -EAFNOSUPPORT;
891 NL_SET_ERR_MSG(extack, "Rule family not supported");
892 goto errout;
893 }
894
895 err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX,
896 fib_rule_policy, extack);
897 if (err < 0) {
898 NL_SET_ERR_MSG(extack, "Error parsing msg");
899 goto errout;
900 }
901
902 err = fib_nl2rule(net, nlh, extack, ops, tb, &rule, &user_priority);
903 if (err)
904 goto errout;
905
906 if (!rtnl_held)
907 rtnl_net_lock(net);
908
909 err = fib_nl2rule_rtnl(rule, ops, tb, extack);
910 if (err)
911 goto errout_free;
912
913 if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
914 rule_exists(ops, frh, tb, rule)) {
915 err = -EEXIST;
916 goto errout_free;
917 }
918
919 err = ops->configure(rule, skb, frh, tb, extack);
920 if (err < 0)
921 goto errout_free;
922
923 err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops,
924 extack);
925 if (err < 0)
926 goto errout_free;
927
928 list_for_each_entry(r, &ops->rules_list, list) {
929 if (r->pref == rule->target) {
930 RCU_INIT_POINTER(rule->ctarget, r);
931 break;
932 }
933 }
934
935 if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
936 unresolved = 1;
937
938 list_for_each_entry(r, &ops->rules_list, list) {
939 if (r->pref > rule->pref)
940 break;
941 last = r;
942 }
943
944 if (last)
945 list_add_rcu(&rule->list, &last->list);
946 else
947 list_add_rcu(&rule->list, &ops->rules_list);
948
949 if (ops->unresolved_rules) {
950 /*
951 * There are unresolved goto rules in the list, check if
952 * any of them are pointing to this new rule.
953 */
954 list_for_each_entry(r, &ops->rules_list, list) {
955 if (r->action == FR_ACT_GOTO &&
956 r->target == rule->pref &&
957 rtnl_dereference(r->ctarget) == NULL) {
958 rcu_assign_pointer(r->ctarget, rule);
959 if (--ops->unresolved_rules == 0)
960 break;
961 }
962 }
963 }
964
965 if (rule->action == FR_ACT_GOTO)
966 ops->nr_goto_rules++;
967
968 if (unresolved)
969 ops->unresolved_rules++;
970
971 if (rule->tun_id)
972 ip_tunnel_need_metadata();
973
974 fib_rule_get(rule);
975
976 if (!rtnl_held)
977 rtnl_net_unlock(net);
978
979 notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
980 fib_rule_put(rule);
981 flush_route_cache(ops);
982 rules_ops_put(ops);
983 return 0;
984
985 errout_free:
986 if (!rtnl_held)
987 rtnl_net_unlock(net);
988 kfree(rule);
989 errout:
990 rules_ops_put(ops);
991 return err;
992 }
993 EXPORT_SYMBOL_GPL(fib_newrule);
994
fib_nl_newrule(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)995 static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
996 struct netlink_ext_ack *extack)
997 {
998 return fib_newrule(sock_net(skb->sk), skb, nlh, extack, false);
999 }
1000
fib_delrule(struct net * net,struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack,bool rtnl_held)1001 int fib_delrule(struct net *net, struct sk_buff *skb, struct nlmsghdr *nlh,
1002 struct netlink_ext_ack *extack, bool rtnl_held)
1003 {
1004 struct fib_rule *rule = NULL, *nlrule = NULL;
1005 struct fib_rule_hdr *frh = nlmsg_data(nlh);
1006 struct fib_rules_ops *ops = NULL;
1007 struct nlattr *tb[FRA_MAX+1];
1008 bool user_priority = false;
1009 int err = -EINVAL;
1010
1011 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
1012 NL_SET_ERR_MSG(extack, "Invalid msg length");
1013 goto errout;
1014 }
1015
1016 ops = lookup_rules_ops(net, frh->family);
1017 if (ops == NULL) {
1018 err = -EAFNOSUPPORT;
1019 NL_SET_ERR_MSG(extack, "Rule family not supported");
1020 goto errout;
1021 }
1022
1023 err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX,
1024 fib_rule_policy, extack);
1025 if (err < 0) {
1026 NL_SET_ERR_MSG(extack, "Error parsing msg");
1027 goto errout;
1028 }
1029
1030 err = fib_nl2rule(net, nlh, extack, ops, tb, &nlrule, &user_priority);
1031 if (err)
1032 goto errout;
1033
1034 if (!rtnl_held)
1035 rtnl_net_lock(net);
1036
1037 err = fib_nl2rule_rtnl(nlrule, ops, tb, extack);
1038 if (err)
1039 goto errout_free;
1040
1041 rule = rule_find(ops, frh, tb, nlrule, user_priority);
1042 if (!rule) {
1043 err = -ENOENT;
1044 goto errout_free;
1045 }
1046
1047 if (rule->flags & FIB_RULE_PERMANENT) {
1048 err = -EPERM;
1049 goto errout_free;
1050 }
1051
1052 if (ops->delete) {
1053 err = ops->delete(rule);
1054 if (err)
1055 goto errout_free;
1056 }
1057
1058 if (rule->tun_id)
1059 ip_tunnel_unneed_metadata();
1060
1061 list_del_rcu(&rule->list);
1062
1063 if (rule->action == FR_ACT_GOTO) {
1064 ops->nr_goto_rules--;
1065 if (rtnl_dereference(rule->ctarget) == NULL)
1066 ops->unresolved_rules--;
1067 }
1068
1069 /*
1070 * Check if this rule is a target to any of them. If so,
1071 * adjust to the next one with the same preference or
1072 * disable them. As this operation is eventually very
1073 * expensive, it is only performed if goto rules, except
1074 * current if it is goto rule, have actually been added.
1075 */
1076 if (ops->nr_goto_rules > 0) {
1077 struct fib_rule *n, *r;
1078
1079 n = list_next_entry(rule, list);
1080 if (&n->list == &ops->rules_list || n->pref != rule->pref)
1081 n = NULL;
1082 list_for_each_entry(r, &ops->rules_list, list) {
1083 if (rtnl_dereference(r->ctarget) != rule)
1084 continue;
1085 rcu_assign_pointer(r->ctarget, n);
1086 if (!n)
1087 ops->unresolved_rules++;
1088 }
1089 }
1090
1091 call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops, NULL);
1092
1093 if (!rtnl_held)
1094 rtnl_net_unlock(net);
1095
1096 notify_rule_change(RTM_DELRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
1097 fib_rule_put(rule);
1098 flush_route_cache(ops);
1099 rules_ops_put(ops);
1100 kfree(nlrule);
1101 return 0;
1102
1103 errout_free:
1104 if (!rtnl_held)
1105 rtnl_net_unlock(net);
1106 kfree(nlrule);
1107 errout:
1108 rules_ops_put(ops);
1109 return err;
1110 }
1111 EXPORT_SYMBOL_GPL(fib_delrule);
1112
fib_nl_delrule(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)1113 static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
1114 struct netlink_ext_ack *extack)
1115 {
1116 return fib_delrule(sock_net(skb->sk), skb, nlh, extack, false);
1117 }
1118
fib_rule_nlmsg_size(struct fib_rules_ops * ops,struct fib_rule * rule)1119 static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
1120 struct fib_rule *rule)
1121 {
1122 size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
1123 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
1124 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
1125 + nla_total_size(4) /* FRA_PRIORITY */
1126 + nla_total_size(4) /* FRA_TABLE */
1127 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
1128 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
1129 + nla_total_size(4) /* FRA_FWMARK */
1130 + nla_total_size(4) /* FRA_FWMASK */
1131 + nla_total_size_64bit(8) /* FRA_TUN_ID */
1132 + nla_total_size(sizeof(struct fib_kuid_range))
1133 + nla_total_size(1) /* FRA_PROTOCOL */
1134 + nla_total_size(1) /* FRA_IP_PROTO */
1135 + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */
1136 + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_DPORT_RANGE */
1137 + nla_total_size(2) /* FRA_SPORT_MASK */
1138 + nla_total_size(2); /* FRA_DPORT_MASK */
1139
1140 if (ops->nlmsg_payload)
1141 payload += ops->nlmsg_payload(rule);
1142
1143 return payload;
1144 }
1145
fib_nl_fill_rule(struct sk_buff * skb,struct fib_rule * rule,u32 pid,u32 seq,int type,int flags,struct fib_rules_ops * ops)1146 static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
1147 u32 pid, u32 seq, int type, int flags,
1148 struct fib_rules_ops *ops)
1149 {
1150 struct nlmsghdr *nlh;
1151 struct fib_rule_hdr *frh;
1152
1153 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
1154 if (nlh == NULL)
1155 return -EMSGSIZE;
1156
1157 frh = nlmsg_data(nlh);
1158 frh->family = ops->family;
1159 frh->table = rule->table < 256 ? rule->table : RT_TABLE_COMPAT;
1160 if (nla_put_u32(skb, FRA_TABLE, rule->table))
1161 goto nla_put_failure;
1162 if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
1163 goto nla_put_failure;
1164 frh->res1 = 0;
1165 frh->res2 = 0;
1166 frh->action = rule->action;
1167 frh->flags = rule->flags;
1168
1169 if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto))
1170 goto nla_put_failure;
1171
1172 if (rule->action == FR_ACT_GOTO &&
1173 rcu_access_pointer(rule->ctarget) == NULL)
1174 frh->flags |= FIB_RULE_UNRESOLVED;
1175
1176 if (rule->iifname[0]) {
1177 if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
1178 goto nla_put_failure;
1179 if (READ_ONCE(rule->iifindex) == -1)
1180 frh->flags |= FIB_RULE_IIF_DETACHED;
1181 }
1182
1183 if (rule->oifname[0]) {
1184 if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
1185 goto nla_put_failure;
1186 if (READ_ONCE(rule->oifindex) == -1)
1187 frh->flags |= FIB_RULE_OIF_DETACHED;
1188 }
1189
1190 if ((rule->pref &&
1191 nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
1192 (rule->mark &&
1193 nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
1194 ((rule->mark_mask || rule->mark) &&
1195 nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
1196 (rule->target &&
1197 nla_put_u32(skb, FRA_GOTO, rule->target)) ||
1198 (rule->tun_id &&
1199 nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) ||
1200 (rule->l3mdev &&
1201 nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) ||
1202 (uid_range_set(&rule->uid_range) &&
1203 nla_put_uid_range(skb, &rule->uid_range)) ||
1204 (fib_rule_port_range_set(&rule->sport_range) &&
1205 nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) ||
1206 (rule->sport_mask && nla_put_u16(skb, FRA_SPORT_MASK,
1207 rule->sport_mask)) ||
1208 (fib_rule_port_range_set(&rule->dport_range) &&
1209 nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) ||
1210 (rule->dport_mask && nla_put_u16(skb, FRA_DPORT_MASK,
1211 rule->dport_mask)) ||
1212 (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto)))
1213 goto nla_put_failure;
1214
1215 if (rule->suppress_ifgroup != -1) {
1216 if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
1217 goto nla_put_failure;
1218 }
1219
1220 if (ops->fill(rule, skb, frh) < 0)
1221 goto nla_put_failure;
1222
1223 nlmsg_end(skb, nlh);
1224 return 0;
1225
1226 nla_put_failure:
1227 nlmsg_cancel(skb, nlh);
1228 return -EMSGSIZE;
1229 }
1230
dump_rules(struct sk_buff * skb,struct netlink_callback * cb,struct fib_rules_ops * ops)1231 static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
1232 struct fib_rules_ops *ops)
1233 {
1234 int idx = 0;
1235 struct fib_rule *rule;
1236 int err = 0;
1237
1238 rcu_read_lock();
1239 list_for_each_entry_rcu(rule, &ops->rules_list, list) {
1240 if (idx < cb->args[1])
1241 goto skip;
1242
1243 err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
1244 cb->nlh->nlmsg_seq, RTM_NEWRULE,
1245 NLM_F_MULTI, ops);
1246 if (err)
1247 break;
1248 skip:
1249 idx++;
1250 }
1251 rcu_read_unlock();
1252 cb->args[1] = idx;
1253 rules_ops_put(ops);
1254
1255 return err;
1256 }
1257
fib_valid_dumprule_req(const struct nlmsghdr * nlh,struct netlink_ext_ack * extack)1258 static int fib_valid_dumprule_req(const struct nlmsghdr *nlh,
1259 struct netlink_ext_ack *extack)
1260 {
1261 struct fib_rule_hdr *frh;
1262
1263 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) {
1264 NL_SET_ERR_MSG(extack, "Invalid header for fib rule dump request");
1265 return -EINVAL;
1266 }
1267
1268 frh = nlmsg_data(nlh);
1269 if (frh->dst_len || frh->src_len || frh->tos || frh->table ||
1270 frh->res1 || frh->res2 || frh->action || frh->flags) {
1271 NL_SET_ERR_MSG(extack,
1272 "Invalid values in header for fib rule dump request");
1273 return -EINVAL;
1274 }
1275
1276 if (nlmsg_attrlen(nlh, sizeof(*frh))) {
1277 NL_SET_ERR_MSG(extack, "Invalid data after header in fib rule dump request");
1278 return -EINVAL;
1279 }
1280
1281 return 0;
1282 }
1283
fib_nl_dumprule(struct sk_buff * skb,struct netlink_callback * cb)1284 static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
1285 {
1286 const struct nlmsghdr *nlh = cb->nlh;
1287 struct net *net = sock_net(skb->sk);
1288 struct fib_rules_ops *ops;
1289 int err, idx = 0, family;
1290
1291 if (cb->strict_check) {
1292 err = fib_valid_dumprule_req(nlh, cb->extack);
1293
1294 if (err < 0)
1295 return err;
1296 }
1297
1298 family = rtnl_msg_family(nlh);
1299 if (family != AF_UNSPEC) {
1300 /* Protocol specific dump request */
1301 ops = lookup_rules_ops(net, family);
1302 if (ops == NULL)
1303 return -EAFNOSUPPORT;
1304
1305 return dump_rules(skb, cb, ops);
1306 }
1307
1308 err = 0;
1309 rcu_read_lock();
1310 list_for_each_entry_rcu(ops, &net->rules_ops, list) {
1311 if (idx < cb->args[0] || !try_module_get(ops->owner))
1312 goto skip;
1313
1314 err = dump_rules(skb, cb, ops);
1315 if (err < 0)
1316 break;
1317
1318 cb->args[1] = 0;
1319 skip:
1320 idx++;
1321 }
1322 rcu_read_unlock();
1323 cb->args[0] = idx;
1324
1325 return err;
1326 }
1327
notify_rule_change(int event,struct fib_rule * rule,struct fib_rules_ops * ops,struct nlmsghdr * nlh,u32 pid)1328 static void notify_rule_change(int event, struct fib_rule *rule,
1329 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
1330 u32 pid)
1331 {
1332 struct net *net;
1333 struct sk_buff *skb;
1334 int err = -ENOMEM;
1335
1336 net = ops->fro_net;
1337 skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
1338 if (skb == NULL)
1339 goto errout;
1340
1341 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
1342 if (err < 0) {
1343 /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
1344 WARN_ON(err == -EMSGSIZE);
1345 kfree_skb(skb);
1346 goto errout;
1347 }
1348
1349 rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
1350 return;
1351 errout:
1352 rtnl_set_sk_err(net, ops->nlgroup, err);
1353 }
1354
attach_rules(struct list_head * rules,struct net_device * dev)1355 static void attach_rules(struct list_head *rules, struct net_device *dev)
1356 {
1357 struct fib_rule *rule;
1358
1359 list_for_each_entry(rule, rules, list) {
1360 if (rule->iifindex == -1 &&
1361 strcmp(dev->name, rule->iifname) == 0) {
1362 WRITE_ONCE(rule->iifindex, dev->ifindex);
1363 WRITE_ONCE(rule->iif_is_l3_master,
1364 netif_is_l3_master(dev));
1365 }
1366 if (rule->oifindex == -1 &&
1367 strcmp(dev->name, rule->oifname) == 0) {
1368 WRITE_ONCE(rule->oifindex, dev->ifindex);
1369 WRITE_ONCE(rule->oif_is_l3_master,
1370 netif_is_l3_master(dev));
1371 }
1372 }
1373 }
1374
detach_rules(struct list_head * rules,struct net_device * dev)1375 static void detach_rules(struct list_head *rules, struct net_device *dev)
1376 {
1377 struct fib_rule *rule;
1378
1379 list_for_each_entry(rule, rules, list) {
1380 if (rule->iifindex == dev->ifindex) {
1381 WRITE_ONCE(rule->iifindex, -1);
1382 WRITE_ONCE(rule->iif_is_l3_master, false);
1383 }
1384 if (rule->oifindex == dev->ifindex) {
1385 WRITE_ONCE(rule->oifindex, -1);
1386 WRITE_ONCE(rule->oif_is_l3_master, false);
1387 }
1388 }
1389 }
1390
1391
fib_rules_event(struct notifier_block * this,unsigned long event,void * ptr)1392 static int fib_rules_event(struct notifier_block *this, unsigned long event,
1393 void *ptr)
1394 {
1395 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1396 struct net *net = dev_net(dev);
1397 struct fib_rules_ops *ops;
1398
1399 ASSERT_RTNL();
1400
1401 switch (event) {
1402 case NETDEV_REGISTER:
1403 list_for_each_entry(ops, &net->rules_ops, list)
1404 attach_rules(&ops->rules_list, dev);
1405 break;
1406
1407 case NETDEV_CHANGENAME:
1408 list_for_each_entry(ops, &net->rules_ops, list) {
1409 detach_rules(&ops->rules_list, dev);
1410 attach_rules(&ops->rules_list, dev);
1411 }
1412 break;
1413
1414 case NETDEV_UNREGISTER:
1415 list_for_each_entry(ops, &net->rules_ops, list)
1416 detach_rules(&ops->rules_list, dev);
1417 break;
1418 }
1419
1420 return NOTIFY_DONE;
1421 }
1422
1423 static struct notifier_block fib_rules_notifier = {
1424 .notifier_call = fib_rules_event,
1425 };
1426
fib_rules_net_init(struct net * net)1427 static int __net_init fib_rules_net_init(struct net *net)
1428 {
1429 INIT_LIST_HEAD(&net->rules_ops);
1430 spin_lock_init(&net->rules_mod_lock);
1431 return 0;
1432 }
1433
fib_rules_net_exit(struct net * net)1434 static void __net_exit fib_rules_net_exit(struct net *net)
1435 {
1436 WARN_ON_ONCE(!list_empty(&net->rules_ops));
1437 }
1438
1439 static struct pernet_operations fib_rules_net_ops = {
1440 .init = fib_rules_net_init,
1441 .exit = fib_rules_net_exit,
1442 };
1443
1444 static const struct rtnl_msg_handler fib_rules_rtnl_msg_handlers[] __initconst = {
1445 {.msgtype = RTM_NEWRULE, .doit = fib_nl_newrule,
1446 .flags = RTNL_FLAG_DOIT_PERNET},
1447 {.msgtype = RTM_DELRULE, .doit = fib_nl_delrule,
1448 .flags = RTNL_FLAG_DOIT_PERNET},
1449 {.msgtype = RTM_GETRULE, .dumpit = fib_nl_dumprule,
1450 .flags = RTNL_FLAG_DUMP_UNLOCKED},
1451 };
1452
fib_rules_init(void)1453 static int __init fib_rules_init(void)
1454 {
1455 int err;
1456
1457 rtnl_register_many(fib_rules_rtnl_msg_handlers);
1458
1459 err = register_pernet_subsys(&fib_rules_net_ops);
1460 if (err < 0)
1461 goto fail;
1462
1463 err = register_netdevice_notifier(&fib_rules_notifier);
1464 if (err < 0)
1465 goto fail_unregister;
1466
1467 return 0;
1468
1469 fail_unregister:
1470 unregister_pernet_subsys(&fib_rules_net_ops);
1471 fail:
1472 rtnl_unregister_many(fib_rules_rtnl_msg_handlers);
1473 return err;
1474 }
1475
1476 subsys_initcall(fib_rules_init);
1477