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,
51 struct netlink_ext_ack *extack)
53 return fib_rules_dump(net, nb, AF_INET6, extack);
56 unsigned int fib6_rules_seq_read(struct net *net)
58 return fib_rules_seq_read(net, AF_INET6);
61 /* called with rcu lock held; no reference taken on fib6_info */
62 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
63 struct fib6_result *res, int flags)
67 if (net->ipv6.fib6_has_custom_rules) {
68 struct fib_lookup_arg arg = {
69 .lookup_ptr = fib6_table_lookup,
72 .flags = FIB_LOOKUP_NOREF,
75 l3mdev_update_flow(net, flowi6_to_flowi(fl6));
77 err = fib_rules_lookup(net->ipv6.fib6_rules_ops,
78 flowi6_to_flowi(fl6), flags, &arg);
80 err = fib6_table_lookup(net, net->ipv6.fib6_local_tbl, oif,
82 if (err || res->f6i == net->ipv6.fib6_null_entry)
83 err = fib6_table_lookup(net, net->ipv6.fib6_main_tbl,
84 oif, fl6, res, flags);
90 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
91 const struct sk_buff *skb,
92 int flags, pol_lookup_t lookup)
94 if (net->ipv6.fib6_has_custom_rules) {
95 struct fib6_result res = {};
96 struct fib_lookup_arg arg = {
100 .flags = FIB_LOOKUP_NOREF,
103 /* update flow if oif or iif point to device enslaved to l3mdev */
104 l3mdev_update_flow(net, flowi6_to_flowi(fl6));
106 fib_rules_lookup(net->ipv6.fib6_rules_ops,
107 flowi6_to_flowi(fl6), flags, &arg);
110 return &res.rt6->dst;
114 rt = lookup(net, net->ipv6.fib6_local_tbl, fl6, skb, flags);
115 if (rt != net->ipv6.ip6_null_entry && rt->dst.error != -EAGAIN)
117 ip6_rt_put_flags(rt, flags);
118 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
119 if (rt->dst.error != -EAGAIN)
121 ip6_rt_put_flags(rt, flags);
124 if (!(flags & RT6_LOOKUP_F_DST_NOREF))
125 dst_hold(&net->ipv6.ip6_null_entry->dst);
126 return &net->ipv6.ip6_null_entry->dst;
129 static int fib6_rule_saddr(struct net *net, struct fib_rule *rule, int flags,
130 struct flowi6 *flp6, const struct net_device *dev)
132 struct fib6_rule *r = (struct fib6_rule *)rule;
134 /* If we need to find a source address for this traffic,
135 * we check the result if it meets requirement of the rule.
137 if ((rule->flags & FIB_RULE_FIND_SADDR) &&
138 r->src.plen && !(flags & RT6_LOOKUP_F_HAS_SADDR)) {
139 struct in6_addr saddr;
141 if (ipv6_dev_get_saddr(net, dev, &flp6->daddr,
142 rt6_flags2srcprefs(flags), &saddr))
145 if (!ipv6_prefix_equal(&saddr, &r->src.addr, r->src.plen))
154 static int fib6_rule_action_alt(struct fib_rule *rule, struct flowi *flp,
155 int flags, struct fib_lookup_arg *arg)
157 struct fib6_result *res = arg->result;
158 struct flowi6 *flp6 = &flp->u.ip6;
159 struct net *net = rule->fr_net;
160 struct fib6_table *table;
164 switch (rule->action) {
167 case FR_ACT_UNREACHABLE:
169 case FR_ACT_PROHIBIT:
171 case FR_ACT_BLACKHOLE:
176 tb_id = fib_rule_get_table(rule, arg);
177 table = fib6_get_table(net, tb_id);
181 oif = (int *)arg->lookup_data;
182 err = fib6_table_lookup(net, table, *oif, flp6, res, flags);
183 if (!err && res->f6i != net->ipv6.fib6_null_entry)
184 err = fib6_rule_saddr(net, rule, flags, flp6,
185 res->nh->fib_nh_dev);
192 static int __fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
193 int flags, struct fib_lookup_arg *arg)
195 struct fib6_result *res = arg->result;
196 struct flowi6 *flp6 = &flp->u.ip6;
197 struct rt6_info *rt = NULL;
198 struct fib6_table *table;
199 struct net *net = rule->fr_net;
200 pol_lookup_t lookup = arg->lookup_ptr;
204 switch (rule->action) {
207 case FR_ACT_UNREACHABLE:
209 rt = net->ipv6.ip6_null_entry;
212 case FR_ACT_BLACKHOLE:
214 rt = net->ipv6.ip6_blk_hole_entry;
216 case FR_ACT_PROHIBIT:
218 rt = net->ipv6.ip6_prohibit_entry;
222 tb_id = fib_rule_get_table(rule, arg);
223 table = fib6_get_table(net, tb_id);
229 rt = lookup(net, table, flp6, arg->lookup_data, flags);
230 if (rt != net->ipv6.ip6_null_entry) {
231 err = fib6_rule_saddr(net, rule, flags, flp6,
232 ip6_dst_idev(&rt->dst)->dev);
242 ip6_rt_put_flags(rt, flags);
248 if (!(flags & RT6_LOOKUP_F_DST_NOREF))
255 static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
256 int flags, struct fib_lookup_arg *arg)
258 if (arg->lookup_ptr == fib6_table_lookup)
259 return fib6_rule_action_alt(rule, flp, flags, arg);
261 return __fib6_rule_action(rule, flp, flags, arg);
264 static bool fib6_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)
266 struct fib6_result *res = arg->result;
267 struct rt6_info *rt = res->rt6;
268 struct net_device *dev = NULL;
274 dev = rt->rt6i_idev->dev;
276 /* do not accept result if the route does
277 * not meet the required prefix length
279 if (rt->rt6i_dst.plen <= rule->suppress_prefixlen)
282 /* do not accept result if the route uses a device
283 * belonging to a forbidden interface group
285 if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
291 if (!(arg->flags & FIB_LOOKUP_NOREF))
296 static int fib6_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
298 struct fib6_rule *r = (struct fib6_rule *) rule;
299 struct flowi6 *fl6 = &fl->u.ip6;
302 !ipv6_prefix_equal(&fl6->daddr, &r->dst.addr, r->dst.plen))
306 * If FIB_RULE_FIND_SADDR is set and we do not have a
307 * source address for the traffic, we defer check for
311 if (flags & RT6_LOOKUP_F_HAS_SADDR) {
312 if (!ipv6_prefix_equal(&fl6->saddr, &r->src.addr,
315 } else if (!(r->common.flags & FIB_RULE_FIND_SADDR))
319 if (r->tclass && r->tclass != ip6_tclass(fl6->flowlabel))
322 if (rule->ip_proto && (rule->ip_proto != fl6->flowi6_proto))
325 if (fib_rule_port_range_set(&rule->sport_range) &&
326 !fib_rule_port_inrange(&rule->sport_range, fl6->fl6_sport))
329 if (fib_rule_port_range_set(&rule->dport_range) &&
330 !fib_rule_port_inrange(&rule->dport_range, fl6->fl6_dport))
336 static const struct nla_policy fib6_rule_policy[FRA_MAX+1] = {
340 static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
341 struct fib_rule_hdr *frh,
343 struct netlink_ext_ack *extack)
346 struct net *net = sock_net(skb->sk);
347 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
349 if (rule->action == FR_ACT_TO_TBL && !rule->l3mdev) {
350 if (rule->table == RT6_TABLE_UNSPEC) {
351 NL_SET_ERR_MSG(extack, "Invalid table");
355 if (fib6_new_table(net, rule->table) == NULL) {
362 rule6->src.addr = nla_get_in6_addr(tb[FRA_SRC]);
365 rule6->dst.addr = nla_get_in6_addr(tb[FRA_DST]);
367 rule6->src.plen = frh->src_len;
368 rule6->dst.plen = frh->dst_len;
369 rule6->tclass = frh->tos;
371 if (fib_rule_requires_fldissect(rule))
372 net->ipv6.fib6_rules_require_fldissect++;
374 net->ipv6.fib6_has_custom_rules = true;
380 static int fib6_rule_delete(struct fib_rule *rule)
382 struct net *net = rule->fr_net;
384 if (net->ipv6.fib6_rules_require_fldissect &&
385 fib_rule_requires_fldissect(rule))
386 net->ipv6.fib6_rules_require_fldissect--;
391 static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
394 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
396 if (frh->src_len && (rule6->src.plen != frh->src_len))
399 if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
402 if (frh->tos && (rule6->tclass != frh->tos))
406 nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
410 nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
416 static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
417 struct fib_rule_hdr *frh)
419 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
421 frh->dst_len = rule6->dst.plen;
422 frh->src_len = rule6->src.plen;
423 frh->tos = rule6->tclass;
425 if ((rule6->dst.plen &&
426 nla_put_in6_addr(skb, FRA_DST, &rule6->dst.addr)) ||
428 nla_put_in6_addr(skb, FRA_SRC, &rule6->src.addr)))
429 goto nla_put_failure;
436 static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
438 return nla_total_size(16) /* dst */
439 + nla_total_size(16); /* src */
442 static const struct fib_rules_ops __net_initconst fib6_rules_ops_template = {
444 .rule_size = sizeof(struct fib6_rule),
445 .addr_size = sizeof(struct in6_addr),
446 .action = fib6_rule_action,
447 .match = fib6_rule_match,
448 .suppress = fib6_rule_suppress,
449 .configure = fib6_rule_configure,
450 .delete = fib6_rule_delete,
451 .compare = fib6_rule_compare,
452 .fill = fib6_rule_fill,
453 .nlmsg_payload = fib6_rule_nlmsg_payload,
454 .nlgroup = RTNLGRP_IPV6_RULE,
455 .policy = fib6_rule_policy,
456 .owner = THIS_MODULE,
457 .fro_net = &init_net,
460 static int __net_init fib6_rules_net_init(struct net *net)
462 struct fib_rules_ops *ops;
465 ops = fib_rules_register(&fib6_rules_ops_template, net);
469 err = fib_default_rule_add(ops, 0, RT6_TABLE_LOCAL, 0);
471 goto out_fib6_rules_ops;
473 err = fib_default_rule_add(ops, 0x7FFE, RT6_TABLE_MAIN, 0);
475 goto out_fib6_rules_ops;
477 net->ipv6.fib6_rules_ops = ops;
478 net->ipv6.fib6_rules_require_fldissect = 0;
483 fib_rules_unregister(ops);
487 static void __net_exit fib6_rules_net_exit(struct net *net)
490 fib_rules_unregister(net->ipv6.fib6_rules_ops);
494 static struct pernet_operations fib6_rules_net_ops = {
495 .init = fib6_rules_net_init,
496 .exit = fib6_rules_net_exit,
499 int __init fib6_rules_init(void)
501 return register_pernet_subsys(&fib6_rules_net_ops);
505 void fib6_rules_cleanup(void)
507 unregister_pernet_subsys(&fib6_rules_net_ops);