1 // SPDX-License-Identifier: GPL-2.0-only
3 * net/ipv6/fib6_rules.c IPv6 Routing Policy Rules
5 * Copyright (C)2003-2006 Helsinki University of Technology
6 * Copyright (C)2003-2006 USAGI/WIDE Project
9 * Thomas Graf <tgraf@suug.ch>
10 * Ville Nuorvala <vnuorval@tcs.hut.fi>
13 #include <linux/netdevice.h>
14 #include <linux/notifier.h>
15 #include <linux/export.h>
17 #include <net/fib_rules.h>
19 #include <net/addrconf.h>
20 #include <net/ip6_route.h>
21 #include <net/netlink.h>
24 struct fib_rule common;
30 static bool fib6_rule_matchall(const struct fib_rule *rule)
32 struct fib6_rule *r = container_of(rule, struct fib6_rule, common);
34 if (r->dst.plen || r->src.plen || r->tclass)
36 return fib_rule_matchall(rule);
39 bool fib6_rule_default(const struct fib_rule *rule)
41 if (!fib6_rule_matchall(rule) || rule->action != FR_ACT_TO_TBL ||
44 if (rule->table != RT6_TABLE_LOCAL && rule->table != RT6_TABLE_MAIN)
48 EXPORT_SYMBOL_GPL(fib6_rule_default);
50 int fib6_rules_dump(struct net *net, struct notifier_block *nb)
52 return fib_rules_dump(net, nb, AF_INET6);
55 unsigned int fib6_rules_seq_read(struct net *net)
57 return fib_rules_seq_read(net, AF_INET6);
60 /* called with rcu lock held; no reference taken on fib6_info */
61 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
62 struct fib6_result *res, int flags)
66 if (net->ipv6.fib6_has_custom_rules) {
67 struct fib_lookup_arg arg = {
68 .lookup_ptr = fib6_table_lookup,
71 .flags = FIB_LOOKUP_NOREF,
74 l3mdev_update_flow(net, flowi6_to_flowi(fl6));
76 err = fib_rules_lookup(net->ipv6.fib6_rules_ops,
77 flowi6_to_flowi(fl6), flags, &arg);
79 err = fib6_table_lookup(net, net->ipv6.fib6_local_tbl, oif,
81 if (err || res->f6i == net->ipv6.fib6_null_entry)
82 err = fib6_table_lookup(net, net->ipv6.fib6_main_tbl,
83 oif, fl6, res, flags);
89 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
90 const struct sk_buff *skb,
91 int flags, pol_lookup_t lookup)
93 if (net->ipv6.fib6_has_custom_rules) {
94 struct fib6_result res = {};
95 struct fib_lookup_arg arg = {
99 .flags = FIB_LOOKUP_NOREF,
102 /* update flow if oif or iif point to device enslaved to l3mdev */
103 l3mdev_update_flow(net, flowi6_to_flowi(fl6));
105 fib_rules_lookup(net->ipv6.fib6_rules_ops,
106 flowi6_to_flowi(fl6), flags, &arg);
109 return &res.rt6->dst;
113 rt = lookup(net, net->ipv6.fib6_local_tbl, fl6, skb, flags);
114 if (rt != net->ipv6.ip6_null_entry && rt->dst.error != -EAGAIN)
116 ip6_rt_put_flags(rt, flags);
117 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
118 if (rt->dst.error != -EAGAIN)
120 ip6_rt_put_flags(rt, flags);
123 if (!(flags & RT6_LOOKUP_F_DST_NOREF))
124 dst_hold(&net->ipv6.ip6_null_entry->dst);
125 return &net->ipv6.ip6_null_entry->dst;
128 static int fib6_rule_saddr(struct net *net, struct fib_rule *rule, int flags,
129 struct flowi6 *flp6, const struct net_device *dev)
131 struct fib6_rule *r = (struct fib6_rule *)rule;
133 /* If we need to find a source address for this traffic,
134 * we check the result if it meets requirement of the rule.
136 if ((rule->flags & FIB_RULE_FIND_SADDR) &&
137 r->src.plen && !(flags & RT6_LOOKUP_F_HAS_SADDR)) {
138 struct in6_addr saddr;
140 if (ipv6_dev_get_saddr(net, dev, &flp6->daddr,
141 rt6_flags2srcprefs(flags), &saddr))
144 if (!ipv6_prefix_equal(&saddr, &r->src.addr, r->src.plen))
153 static int fib6_rule_action_alt(struct fib_rule *rule, struct flowi *flp,
154 int flags, struct fib_lookup_arg *arg)
156 struct fib6_result *res = arg->result;
157 struct flowi6 *flp6 = &flp->u.ip6;
158 struct net *net = rule->fr_net;
159 struct fib6_table *table;
163 switch (rule->action) {
166 case FR_ACT_UNREACHABLE:
168 case FR_ACT_PROHIBIT:
170 case FR_ACT_BLACKHOLE:
175 tb_id = fib_rule_get_table(rule, arg);
176 table = fib6_get_table(net, tb_id);
180 oif = (int *)arg->lookup_data;
181 err = fib6_table_lookup(net, table, *oif, flp6, res, flags);
182 if (!err && res->f6i != net->ipv6.fib6_null_entry)
183 err = fib6_rule_saddr(net, rule, flags, flp6,
184 res->nh->fib_nh_dev);
191 static int __fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
192 int flags, struct fib_lookup_arg *arg)
194 struct fib6_result *res = arg->result;
195 struct flowi6 *flp6 = &flp->u.ip6;
196 struct rt6_info *rt = NULL;
197 struct fib6_table *table;
198 struct net *net = rule->fr_net;
199 pol_lookup_t lookup = arg->lookup_ptr;
203 switch (rule->action) {
206 case FR_ACT_UNREACHABLE:
208 rt = net->ipv6.ip6_null_entry;
211 case FR_ACT_BLACKHOLE:
213 rt = net->ipv6.ip6_blk_hole_entry;
215 case FR_ACT_PROHIBIT:
217 rt = net->ipv6.ip6_prohibit_entry;
221 tb_id = fib_rule_get_table(rule, arg);
222 table = fib6_get_table(net, tb_id);
228 rt = lookup(net, table, flp6, arg->lookup_data, flags);
229 if (rt != net->ipv6.ip6_null_entry) {
230 err = fib6_rule_saddr(net, rule, flags, flp6,
231 ip6_dst_idev(&rt->dst)->dev);
241 ip6_rt_put_flags(rt, flags);
247 if (!(flags & RT6_LOOKUP_F_DST_NOREF))
254 static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
255 int flags, struct fib_lookup_arg *arg)
257 if (arg->lookup_ptr == fib6_table_lookup)
258 return fib6_rule_action_alt(rule, flp, flags, arg);
260 return __fib6_rule_action(rule, flp, flags, arg);
263 static bool fib6_rule_suppress(struct fib_rule *rule, int flags, struct fib_lookup_arg *arg)
265 struct fib6_result *res = arg->result;
266 struct rt6_info *rt = res->rt6;
267 struct net_device *dev = NULL;
273 dev = rt->rt6i_idev->dev;
275 /* do not accept result if the route does
276 * not meet the required prefix length
278 if (rt->rt6i_dst.plen <= rule->suppress_prefixlen)
281 /* do not accept result if the route uses a device
282 * belonging to a forbidden interface group
284 if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
290 ip6_rt_put_flags(rt, flags);
294 static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
296 struct fib6_rule *r = (struct fib6_rule *) rule;
297 struct flowi6 *fl6 = &fl->u.ip6;
300 !ipv6_prefix_equal(&fl6->daddr, &r->dst.addr, r->dst.plen))
304 * If FIB_RULE_FIND_SADDR is set and we do not have a
305 * source address for the traffic, we defer check for
309 if (flags & RT6_LOOKUP_F_HAS_SADDR) {
310 if (!ipv6_prefix_equal(&fl6->saddr, &r->src.addr,
313 } else if (!(r->common.flags & FIB_RULE_FIND_SADDR))
317 if (r->tclass && r->tclass != ip6_tclass(fl6->flowlabel))
320 if (rule->ip_proto && (rule->ip_proto != fl6->flowi6_proto))
323 if (fib_rule_port_range_set(&rule->sport_range) &&
324 !fib_rule_port_inrange(&rule->sport_range, fl6->fl6_sport))
327 if (fib_rule_port_range_set(&rule->dport_range) &&
328 !fib_rule_port_inrange(&rule->dport_range, fl6->fl6_dport))
334 static const struct nla_policy fib6_rule_policy[FRA_MAX+1] = {
338 static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
339 struct fib_rule_hdr *frh,
341 struct netlink_ext_ack *extack)
344 struct net *net = sock_net(skb->sk);
345 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
347 if (rule->action == FR_ACT_TO_TBL && !rule->l3mdev) {
348 if (rule->table == RT6_TABLE_UNSPEC) {
349 NL_SET_ERR_MSG(extack, "Invalid table");
353 if (fib6_new_table(net, rule->table) == NULL) {
360 rule6->src.addr = nla_get_in6_addr(tb[FRA_SRC]);
363 rule6->dst.addr = nla_get_in6_addr(tb[FRA_DST]);
365 rule6->src.plen = frh->src_len;
366 rule6->dst.plen = frh->dst_len;
367 rule6->tclass = frh->tos;
369 if (fib_rule_requires_fldissect(rule))
370 net->ipv6.fib6_rules_require_fldissect++;
372 net->ipv6.fib6_has_custom_rules = true;
378 static int fib6_rule_delete(struct fib_rule *rule)
380 struct net *net = rule->fr_net;
382 if (net->ipv6.fib6_rules_require_fldissect &&
383 fib_rule_requires_fldissect(rule))
384 net->ipv6.fib6_rules_require_fldissect--;
389 static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
392 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
394 if (frh->src_len && (rule6->src.plen != frh->src_len))
397 if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
400 if (frh->tos && (rule6->tclass != frh->tos))
404 nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
408 nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
414 static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
415 struct fib_rule_hdr *frh)
417 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
419 frh->dst_len = rule6->dst.plen;
420 frh->src_len = rule6->src.plen;
421 frh->tos = rule6->tclass;
423 if ((rule6->dst.plen &&
424 nla_put_in6_addr(skb, FRA_DST, &rule6->dst.addr)) ||
426 nla_put_in6_addr(skb, FRA_SRC, &rule6->src.addr)))
427 goto nla_put_failure;
434 static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
436 return nla_total_size(16) /* dst */
437 + nla_total_size(16); /* src */
440 static const struct fib_rules_ops __net_initconst fib6_rules_ops_template = {
442 .rule_size = sizeof(struct fib6_rule),
443 .addr_size = sizeof(struct in6_addr),
444 .action = fib6_rule_action,
445 .match = fib6_rule_match,
446 .suppress = fib6_rule_suppress,
447 .configure = fib6_rule_configure,
448 .delete = fib6_rule_delete,
449 .compare = fib6_rule_compare,
450 .fill = fib6_rule_fill,
451 .nlmsg_payload = fib6_rule_nlmsg_payload,
452 .nlgroup = RTNLGRP_IPV6_RULE,
453 .policy = fib6_rule_policy,
454 .owner = THIS_MODULE,
455 .fro_net = &init_net,
458 static int __net_init fib6_rules_net_init(struct net *net)
460 struct fib_rules_ops *ops;
463 ops = fib_rules_register(&fib6_rules_ops_template, net);
467 err = fib_default_rule_add(ops, 0, RT6_TABLE_LOCAL, 0);
469 goto out_fib6_rules_ops;
471 err = fib_default_rule_add(ops, 0x7FFE, RT6_TABLE_MAIN, 0);
473 goto out_fib6_rules_ops;
475 net->ipv6.fib6_rules_ops = ops;
476 net->ipv6.fib6_rules_require_fldissect = 0;
481 fib_rules_unregister(ops);
485 static void __net_exit fib6_rules_net_exit(struct net *net)
488 fib_rules_unregister(net->ipv6.fib6_rules_ops);
492 static struct pernet_operations fib6_rules_net_ops = {
493 .init = fib6_rules_net_init,
494 .exit = fib6_rules_net_exit,
497 int __init fib6_rules_init(void)
499 return register_pernet_subsys(&fib6_rules_net_ops);
503 void fib6_rules_cleanup(void)
505 unregister_pernet_subsys(&fib6_rules_net_ops);