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>
16 #include <linux/indirect_call_wrapper.h>
18 #include <net/fib_rules.h>
19 #include <net/inet_dscp.h>
21 #include <net/addrconf.h>
22 #include <net/ip6_route.h>
23 #include <net/netlink.h>
26 struct fib_rule common;
32 static bool fib6_rule_matchall(const struct fib_rule *rule)
34 struct fib6_rule *r = container_of(rule, struct fib6_rule, common);
36 if (r->dst.plen || r->src.plen || r->dscp)
38 return fib_rule_matchall(rule);
41 bool fib6_rule_default(const struct fib_rule *rule)
43 if (!fib6_rule_matchall(rule) || rule->action != FR_ACT_TO_TBL ||
46 if (rule->table != RT6_TABLE_LOCAL && rule->table != RT6_TABLE_MAIN)
50 EXPORT_SYMBOL_GPL(fib6_rule_default);
52 int fib6_rules_dump(struct net *net, struct notifier_block *nb,
53 struct netlink_ext_ack *extack)
55 return fib_rules_dump(net, nb, AF_INET6, extack);
58 unsigned int fib6_rules_seq_read(struct net *net)
60 return fib_rules_seq_read(net, AF_INET6);
63 /* called with rcu lock held; no reference taken on fib6_info */
64 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
65 struct fib6_result *res, int flags)
69 if (net->ipv6.fib6_has_custom_rules) {
70 struct fib_lookup_arg arg = {
71 .lookup_ptr = fib6_table_lookup,
74 .flags = FIB_LOOKUP_NOREF,
77 l3mdev_update_flow(net, flowi6_to_flowi(fl6));
79 err = fib_rules_lookup(net->ipv6.fib6_rules_ops,
80 flowi6_to_flowi(fl6), flags, &arg);
82 err = fib6_table_lookup(net, net->ipv6.fib6_local_tbl, oif,
84 if (err || res->f6i == net->ipv6.fib6_null_entry)
85 err = fib6_table_lookup(net, net->ipv6.fib6_main_tbl,
86 oif, fl6, res, flags);
92 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
93 const struct sk_buff *skb,
94 int flags, pol_lookup_t lookup)
96 if (net->ipv6.fib6_has_custom_rules) {
97 struct fib6_result res = {};
98 struct fib_lookup_arg arg = {
102 .flags = FIB_LOOKUP_NOREF,
105 /* update flow if oif or iif point to device enslaved to l3mdev */
106 l3mdev_update_flow(net, flowi6_to_flowi(fl6));
108 fib_rules_lookup(net->ipv6.fib6_rules_ops,
109 flowi6_to_flowi(fl6), flags, &arg);
112 return &res.rt6->dst;
116 rt = pol_lookup_func(lookup,
117 net, net->ipv6.fib6_local_tbl, fl6, skb, flags);
118 if (rt != net->ipv6.ip6_null_entry && rt->dst.error != -EAGAIN)
120 ip6_rt_put_flags(rt, flags);
121 rt = pol_lookup_func(lookup,
122 net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
123 if (rt->dst.error != -EAGAIN)
125 ip6_rt_put_flags(rt, flags);
128 if (!(flags & RT6_LOOKUP_F_DST_NOREF))
129 dst_hold(&net->ipv6.ip6_null_entry->dst);
130 return &net->ipv6.ip6_null_entry->dst;
133 static int fib6_rule_saddr(struct net *net, struct fib_rule *rule, int flags,
134 struct flowi6 *flp6, const struct net_device *dev)
136 struct fib6_rule *r = (struct fib6_rule *)rule;
138 /* If we need to find a source address for this traffic,
139 * we check the result if it meets requirement of the rule.
141 if ((rule->flags & FIB_RULE_FIND_SADDR) &&
142 r->src.plen && !(flags & RT6_LOOKUP_F_HAS_SADDR)) {
143 struct in6_addr saddr;
145 if (ipv6_dev_get_saddr(net, dev, &flp6->daddr,
146 rt6_flags2srcprefs(flags), &saddr))
149 if (!ipv6_prefix_equal(&saddr, &r->src.addr, r->src.plen))
158 static int fib6_rule_action_alt(struct fib_rule *rule, struct flowi *flp,
159 int flags, struct fib_lookup_arg *arg)
161 struct fib6_result *res = arg->result;
162 struct flowi6 *flp6 = &flp->u.ip6;
163 struct net *net = rule->fr_net;
164 struct fib6_table *table;
168 switch (rule->action) {
171 case FR_ACT_UNREACHABLE:
173 case FR_ACT_PROHIBIT:
175 case FR_ACT_BLACKHOLE:
180 tb_id = fib_rule_get_table(rule, arg);
181 table = fib6_get_table(net, tb_id);
185 oif = (int *)arg->lookup_data;
186 err = fib6_table_lookup(net, table, *oif, flp6, res, flags);
187 if (!err && res->f6i != net->ipv6.fib6_null_entry)
188 err = fib6_rule_saddr(net, rule, flags, flp6,
189 res->nh->fib_nh_dev);
196 static int __fib6_rule_action(struct fib_rule *rule, struct flowi *flp,
197 int flags, struct fib_lookup_arg *arg)
199 struct fib6_result *res = arg->result;
200 struct flowi6 *flp6 = &flp->u.ip6;
201 struct rt6_info *rt = NULL;
202 struct fib6_table *table;
203 struct net *net = rule->fr_net;
204 pol_lookup_t lookup = arg->lookup_ptr;
208 switch (rule->action) {
211 case FR_ACT_UNREACHABLE:
213 rt = net->ipv6.ip6_null_entry;
216 case FR_ACT_BLACKHOLE:
218 rt = net->ipv6.ip6_blk_hole_entry;
220 case FR_ACT_PROHIBIT:
222 rt = net->ipv6.ip6_prohibit_entry;
226 tb_id = fib_rule_get_table(rule, arg);
227 table = fib6_get_table(net, tb_id);
233 rt = pol_lookup_func(lookup,
234 net, table, flp6, arg->lookup_data, flags);
235 if (rt != net->ipv6.ip6_null_entry) {
236 struct inet6_dev *idev = ip6_dst_idev(&rt->dst);
240 err = fib6_rule_saddr(net, rule, flags, flp6,
251 ip6_rt_put_flags(rt, flags);
257 if (!(flags & RT6_LOOKUP_F_DST_NOREF))
264 INDIRECT_CALLABLE_SCOPE int fib6_rule_action(struct fib_rule *rule,
265 struct flowi *flp, int flags,
266 struct fib_lookup_arg *arg)
268 if (arg->lookup_ptr == fib6_table_lookup)
269 return fib6_rule_action_alt(rule, flp, flags, arg);
271 return __fib6_rule_action(rule, flp, flags, arg);
274 INDIRECT_CALLABLE_SCOPE bool fib6_rule_suppress(struct fib_rule *rule,
276 struct fib_lookup_arg *arg)
278 struct fib6_result *res = arg->result;
279 struct rt6_info *rt = res->rt6;
280 struct net_device *dev = NULL;
286 dev = rt->rt6i_idev->dev;
288 /* do not accept result if the route does
289 * not meet the required prefix length
291 if (rt->rt6i_dst.plen <= rule->suppress_prefixlen)
294 /* do not accept result if the route uses a device
295 * belonging to a forbidden interface group
297 if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
303 ip6_rt_put_flags(rt, flags);
307 INDIRECT_CALLABLE_SCOPE int fib6_rule_match(struct fib_rule *rule,
308 struct flowi *fl, int flags)
310 struct fib6_rule *r = (struct fib6_rule *) rule;
311 struct flowi6 *fl6 = &fl->u.ip6;
314 !ipv6_prefix_equal(&fl6->daddr, &r->dst.addr, r->dst.plen))
318 * If FIB_RULE_FIND_SADDR is set and we do not have a
319 * source address for the traffic, we defer check for
323 if (flags & RT6_LOOKUP_F_HAS_SADDR) {
324 if (!ipv6_prefix_equal(&fl6->saddr, &r->src.addr,
327 } else if (!(r->common.flags & FIB_RULE_FIND_SADDR))
331 if (r->dscp && r->dscp != ip6_dscp(fl6->flowlabel))
334 if (rule->ip_proto && (rule->ip_proto != fl6->flowi6_proto))
337 if (fib_rule_port_range_set(&rule->sport_range) &&
338 !fib_rule_port_inrange(&rule->sport_range, fl6->fl6_sport))
341 if (fib_rule_port_range_set(&rule->dport_range) &&
342 !fib_rule_port_inrange(&rule->dport_range, fl6->fl6_dport))
348 static int fib6_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
349 struct fib_rule_hdr *frh,
351 struct netlink_ext_ack *extack)
354 struct net *net = sock_net(skb->sk);
355 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
357 if (!inet_validate_dscp(frh->tos)) {
358 NL_SET_ERR_MSG(extack,
359 "Invalid dsfield (tos): ECN bits must be 0");
362 rule6->dscp = inet_dsfield_to_dscp(frh->tos);
364 if (rule->action == FR_ACT_TO_TBL && !rule->l3mdev) {
365 if (rule->table == RT6_TABLE_UNSPEC) {
366 NL_SET_ERR_MSG(extack, "Invalid table");
370 if (fib6_new_table(net, rule->table) == NULL) {
377 rule6->src.addr = nla_get_in6_addr(tb[FRA_SRC]);
380 rule6->dst.addr = nla_get_in6_addr(tb[FRA_DST]);
382 rule6->src.plen = frh->src_len;
383 rule6->dst.plen = frh->dst_len;
385 if (fib_rule_requires_fldissect(rule))
386 net->ipv6.fib6_rules_require_fldissect++;
388 net->ipv6.fib6_has_custom_rules = true;
394 static int fib6_rule_delete(struct fib_rule *rule)
396 struct net *net = rule->fr_net;
398 if (net->ipv6.fib6_rules_require_fldissect &&
399 fib_rule_requires_fldissect(rule))
400 net->ipv6.fib6_rules_require_fldissect--;
405 static int fib6_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
408 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
410 if (frh->src_len && (rule6->src.plen != frh->src_len))
413 if (frh->dst_len && (rule6->dst.plen != frh->dst_len))
416 if (frh->tos && inet_dscp_to_dsfield(rule6->dscp) != frh->tos)
420 nla_memcmp(tb[FRA_SRC], &rule6->src.addr, sizeof(struct in6_addr)))
424 nla_memcmp(tb[FRA_DST], &rule6->dst.addr, sizeof(struct in6_addr)))
430 static int fib6_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
431 struct fib_rule_hdr *frh)
433 struct fib6_rule *rule6 = (struct fib6_rule *) rule;
435 frh->dst_len = rule6->dst.plen;
436 frh->src_len = rule6->src.plen;
437 frh->tos = inet_dscp_to_dsfield(rule6->dscp);
439 if ((rule6->dst.plen &&
440 nla_put_in6_addr(skb, FRA_DST, &rule6->dst.addr)) ||
442 nla_put_in6_addr(skb, FRA_SRC, &rule6->src.addr)))
443 goto nla_put_failure;
450 static size_t fib6_rule_nlmsg_payload(struct fib_rule *rule)
452 return nla_total_size(16) /* dst */
453 + nla_total_size(16); /* src */
456 static void fib6_rule_flush_cache(struct fib_rules_ops *ops)
458 rt_genid_bump_ipv6(ops->fro_net);
461 static const struct fib_rules_ops __net_initconst fib6_rules_ops_template = {
463 .rule_size = sizeof(struct fib6_rule),
464 .addr_size = sizeof(struct in6_addr),
465 .action = fib6_rule_action,
466 .match = fib6_rule_match,
467 .suppress = fib6_rule_suppress,
468 .configure = fib6_rule_configure,
469 .delete = fib6_rule_delete,
470 .compare = fib6_rule_compare,
471 .fill = fib6_rule_fill,
472 .nlmsg_payload = fib6_rule_nlmsg_payload,
473 .flush_cache = fib6_rule_flush_cache,
474 .nlgroup = RTNLGRP_IPV6_RULE,
475 .owner = THIS_MODULE,
476 .fro_net = &init_net,
479 static int __net_init fib6_rules_net_init(struct net *net)
481 struct fib_rules_ops *ops;
484 ops = fib_rules_register(&fib6_rules_ops_template, net);
488 err = fib_default_rule_add(ops, 0, RT6_TABLE_LOCAL, 0);
490 goto out_fib6_rules_ops;
492 err = fib_default_rule_add(ops, 0x7FFE, RT6_TABLE_MAIN, 0);
494 goto out_fib6_rules_ops;
496 net->ipv6.fib6_rules_ops = ops;
497 net->ipv6.fib6_rules_require_fldissect = 0;
502 fib_rules_unregister(ops);
506 static void __net_exit fib6_rules_net_exit_batch(struct list_head *net_list)
511 list_for_each_entry(net, net_list, exit_list) {
512 fib_rules_unregister(net->ipv6.fib6_rules_ops);
518 static struct pernet_operations fib6_rules_net_ops = {
519 .init = fib6_rules_net_init,
520 .exit_batch = fib6_rules_net_exit_batch,
523 int __init fib6_rules_init(void)
525 return register_pernet_subsys(&fib6_rules_net_ops);
529 void fib6_rules_cleanup(void)
531 unregister_pernet_subsys(&fib6_rules_net_ops);