2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * IPv4 Forwarding Information Base: policy rules.
8 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
9 * Thomas Graf <tgraf@suug.ch>
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
17 * Rani Assaf : local_rule cannot be deleted
18 * Marc Boucher : routing by fwmark
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/netdevice.h>
24 #include <linux/netlink.h>
25 #include <linux/inetdevice.h>
26 #include <linux/init.h>
27 #include <linux/list.h>
28 #include <linux/rcupdate.h>
29 #include <linux/export.h>
31 #include <net/route.h>
33 #include <net/ip_fib.h>
34 #include <net/fib_rules.h>
37 struct fib_rule common;
45 #ifdef CONFIG_IP_ROUTE_CLASSID
50 static bool fib4_rule_matchall(const struct fib_rule *rule)
52 struct fib4_rule *r = container_of(rule, struct fib4_rule, common);
54 if (r->dst_len || r->src_len || r->tos)
56 return fib_rule_matchall(rule);
59 bool fib4_rule_default(const struct fib_rule *rule)
61 if (!fib4_rule_matchall(rule) || rule->action != FR_ACT_TO_TBL ||
64 if (rule->table != RT_TABLE_LOCAL && rule->table != RT_TABLE_MAIN &&
65 rule->table != RT_TABLE_DEFAULT)
69 EXPORT_SYMBOL_GPL(fib4_rule_default);
71 int __fib_lookup(struct net *net, struct flowi4 *flp,
72 struct fib_result *res, unsigned int flags)
74 struct fib_lookup_arg arg = {
80 /* update flow if oif or iif point to device enslaved to l3mdev */
81 l3mdev_update_flow(net, flowi4_to_flowi(flp));
83 err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg);
84 #ifdef CONFIG_IP_ROUTE_CLASSID
86 res->tclassid = ((struct fib4_rule *)arg.rule)->tclassid;
96 EXPORT_SYMBOL_GPL(__fib_lookup);
98 static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
99 int flags, struct fib_lookup_arg *arg)
102 struct fib_table *tbl;
105 switch (rule->action) {
109 case FR_ACT_UNREACHABLE:
112 case FR_ACT_PROHIBIT:
115 case FR_ACT_BLACKHOLE:
122 tb_id = fib_rule_get_table(rule, arg);
123 tbl = fib_get_table(rule->fr_net, tb_id);
125 err = fib_table_lookup(tbl, &flp->u.ip4,
126 (struct fib_result *)arg->result,
133 static bool fib4_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)
135 struct fib_result *result = (struct fib_result *) arg->result;
136 struct net_device *dev = NULL;
139 dev = result->fi->fib_dev;
141 /* do not accept result if the route does
142 * not meet the required prefix length
144 if (result->prefixlen <= rule->suppress_prefixlen)
147 /* do not accept result if the route uses a device
148 * belonging to a forbidden interface group
150 if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
156 if (!(arg->flags & FIB_LOOKUP_NOREF))
157 fib_info_put(result->fi);
161 static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
163 struct fib4_rule *r = (struct fib4_rule *) rule;
164 struct flowi4 *fl4 = &fl->u.ip4;
165 __be32 daddr = fl4->daddr;
166 __be32 saddr = fl4->saddr;
168 if (((saddr ^ r->src) & r->srcmask) ||
169 ((daddr ^ r->dst) & r->dstmask))
172 if (r->tos && (r->tos != fl4->flowi4_tos))
178 static struct fib_table *fib_empty_table(struct net *net)
182 for (id = 1; id <= RT_TABLE_MAX; id++)
183 if (!fib_get_table(net, id))
184 return fib_new_table(net, id);
188 static int call_fib_rule_notifier(struct notifier_block *nb, struct net *net,
189 enum fib_event_type event_type,
190 struct fib_rule *rule)
192 struct fib_rule_notifier_info info = {
196 return call_fib_notifier(nb, net, event_type, &info.info);
199 static int call_fib_rule_notifiers(struct net *net,
200 enum fib_event_type event_type,
201 struct fib_rule *rule)
203 struct fib_rule_notifier_info info = {
207 return call_fib_notifiers(net, event_type, &info.info);
210 /* Called with rcu_read_lock() */
211 void fib_rules_notify(struct net *net, struct notifier_block *nb)
213 struct fib_rules_ops *ops = net->ipv4.rules_ops;
214 struct fib_rule *rule;
216 list_for_each_entry_rcu(rule, &ops->rules_list, list)
217 call_fib_rule_notifier(nb, net, FIB_EVENT_RULE_ADD, rule);
220 static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
222 [FRA_FLOW] = { .type = NLA_U32 },
225 static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
226 struct fib_rule_hdr *frh,
229 struct net *net = sock_net(skb->sk);
231 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
233 if (frh->tos & ~IPTOS_TOS_MASK)
236 /* split local/main if they are not already split */
237 err = fib_unmerge(net);
241 if (rule->table == RT_TABLE_UNSPEC && !rule->l3mdev) {
242 if (rule->action == FR_ACT_TO_TBL) {
243 struct fib_table *table;
245 table = fib_empty_table(net);
251 rule->table = table->tb_id;
256 rule4->src = nla_get_in_addr(tb[FRA_SRC]);
259 rule4->dst = nla_get_in_addr(tb[FRA_DST]);
261 #ifdef CONFIG_IP_ROUTE_CLASSID
263 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
265 net->ipv4.fib_num_tclassid_users++;
269 rule4->src_len = frh->src_len;
270 rule4->srcmask = inet_make_mask(rule4->src_len);
271 rule4->dst_len = frh->dst_len;
272 rule4->dstmask = inet_make_mask(rule4->dst_len);
273 rule4->tos = frh->tos;
275 net->ipv4.fib_has_custom_rules = true;
276 call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule);
283 static int fib4_rule_delete(struct fib_rule *rule)
285 struct net *net = rule->fr_net;
288 /* split local/main if they are not already split */
289 err = fib_unmerge(net);
293 #ifdef CONFIG_IP_ROUTE_CLASSID
294 if (((struct fib4_rule *)rule)->tclassid)
295 net->ipv4.fib_num_tclassid_users--;
297 net->ipv4.fib_has_custom_rules = true;
298 call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule);
303 static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
306 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
308 if (frh->src_len && (rule4->src_len != frh->src_len))
311 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
314 if (frh->tos && (rule4->tos != frh->tos))
317 #ifdef CONFIG_IP_ROUTE_CLASSID
318 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
322 if (frh->src_len && (rule4->src != nla_get_in_addr(tb[FRA_SRC])))
325 if (frh->dst_len && (rule4->dst != nla_get_in_addr(tb[FRA_DST])))
331 static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
332 struct fib_rule_hdr *frh)
334 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
336 frh->dst_len = rule4->dst_len;
337 frh->src_len = rule4->src_len;
338 frh->tos = rule4->tos;
340 if ((rule4->dst_len &&
341 nla_put_in_addr(skb, FRA_DST, rule4->dst)) ||
343 nla_put_in_addr(skb, FRA_SRC, rule4->src)))
344 goto nla_put_failure;
345 #ifdef CONFIG_IP_ROUTE_CLASSID
346 if (rule4->tclassid &&
347 nla_put_u32(skb, FRA_FLOW, rule4->tclassid))
348 goto nla_put_failure;
356 static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
358 return nla_total_size(4) /* dst */
359 + nla_total_size(4) /* src */
360 + nla_total_size(4); /* flow */
363 static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
365 rt_cache_flush(ops->fro_net);
368 static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = {
370 .rule_size = sizeof(struct fib4_rule),
371 .addr_size = sizeof(u32),
372 .action = fib4_rule_action,
373 .suppress = fib4_rule_suppress,
374 .match = fib4_rule_match,
375 .configure = fib4_rule_configure,
376 .delete = fib4_rule_delete,
377 .compare = fib4_rule_compare,
378 .fill = fib4_rule_fill,
379 .nlmsg_payload = fib4_rule_nlmsg_payload,
380 .flush_cache = fib4_rule_flush_cache,
381 .nlgroup = RTNLGRP_IPV4_RULE,
382 .policy = fib4_rule_policy,
383 .owner = THIS_MODULE,
386 static int fib_default_rules_init(struct fib_rules_ops *ops)
390 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0);
393 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
396 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
402 int __net_init fib4_rules_init(struct net *net)
405 struct fib_rules_ops *ops;
407 ops = fib_rules_register(&fib4_rules_ops_template, net);
411 err = fib_default_rules_init(ops);
414 net->ipv4.rules_ops = ops;
415 net->ipv4.fib_has_custom_rules = false;
419 /* also cleans all rules already added */
420 fib_rules_unregister(ops);
424 void __net_exit fib4_rules_exit(struct net *net)
426 fib_rules_unregister(net->ipv4.rules_ops);