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 int __fib_lookup(struct net *net, struct flowi4 *flp,
51 struct fib_result *res, unsigned int flags)
53 struct fib_lookup_arg arg = {
59 err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg);
60 #ifdef CONFIG_IP_ROUTE_CLASSID
62 res->tclassid = ((struct fib4_rule *)arg.rule)->tclassid;
72 EXPORT_SYMBOL_GPL(__fib_lookup);
74 static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
75 int flags, struct fib_lookup_arg *arg)
78 struct fib_table *tbl;
81 switch (rule->action) {
85 case FR_ACT_UNREACHABLE:
91 case FR_ACT_BLACKHOLE:
98 tb_id = fib_rule_get_table(rule, arg);
99 tbl = fib_get_table(rule->fr_net, tb_id);
101 err = fib_table_lookup(tbl, &flp->u.ip4,
102 (struct fib_result *)arg->result,
109 static bool fib4_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)
111 struct fib_result *result = (struct fib_result *) arg->result;
112 struct net_device *dev = NULL;
115 dev = result->fi->fib_dev;
117 /* do not accept result if the route does
118 * not meet the required prefix length
120 if (result->prefixlen <= rule->suppress_prefixlen)
123 /* do not accept result if the route uses a device
124 * belonging to a forbidden interface group
126 if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
132 if (!(arg->flags & FIB_LOOKUP_NOREF))
133 fib_info_put(result->fi);
137 static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
139 struct fib4_rule *r = (struct fib4_rule *) rule;
140 struct flowi4 *fl4 = &fl->u.ip4;
141 __be32 daddr = fl4->daddr;
142 __be32 saddr = fl4->saddr;
144 if (((saddr ^ r->src) & r->srcmask) ||
145 ((daddr ^ r->dst) & r->dstmask))
148 if (r->tos && (r->tos != fl4->flowi4_tos))
154 static struct fib_table *fib_empty_table(struct net *net)
158 for (id = 1; id <= RT_TABLE_MAX; id++)
159 if (!fib_get_table(net, id))
160 return fib_new_table(net, id);
164 static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
166 [FRA_FLOW] = { .type = NLA_U32 },
169 static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
170 struct fib_rule_hdr *frh,
173 struct net *net = sock_net(skb->sk);
175 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
177 if (frh->tos & ~IPTOS_TOS_MASK)
180 /* split local/main if they are not already split */
181 err = fib_unmerge(net);
185 if (rule->table == RT_TABLE_UNSPEC && !rule->l3mdev) {
186 if (rule->action == FR_ACT_TO_TBL) {
187 struct fib_table *table;
189 table = fib_empty_table(net);
195 rule->table = table->tb_id;
200 rule4->src = nla_get_in_addr(tb[FRA_SRC]);
203 rule4->dst = nla_get_in_addr(tb[FRA_DST]);
205 #ifdef CONFIG_IP_ROUTE_CLASSID
207 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
209 net->ipv4.fib_num_tclassid_users++;
213 rule4->src_len = frh->src_len;
214 rule4->srcmask = inet_make_mask(rule4->src_len);
215 rule4->dst_len = frh->dst_len;
216 rule4->dstmask = inet_make_mask(rule4->dst_len);
217 rule4->tos = frh->tos;
219 net->ipv4.fib_has_custom_rules = true;
220 fib_flush_external(rule->fr_net);
227 static int fib4_rule_delete(struct fib_rule *rule)
229 struct net *net = rule->fr_net;
232 /* split local/main if they are not already split */
233 err = fib_unmerge(net);
237 #ifdef CONFIG_IP_ROUTE_CLASSID
238 if (((struct fib4_rule *)rule)->tclassid)
239 net->ipv4.fib_num_tclassid_users--;
241 net->ipv4.fib_has_custom_rules = true;
242 fib_flush_external(rule->fr_net);
247 static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
250 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
252 if (frh->src_len && (rule4->src_len != frh->src_len))
255 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
258 if (frh->tos && (rule4->tos != frh->tos))
261 #ifdef CONFIG_IP_ROUTE_CLASSID
262 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
266 if (frh->src_len && (rule4->src != nla_get_in_addr(tb[FRA_SRC])))
269 if (frh->dst_len && (rule4->dst != nla_get_in_addr(tb[FRA_DST])))
275 static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
276 struct fib_rule_hdr *frh)
278 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
280 frh->dst_len = rule4->dst_len;
281 frh->src_len = rule4->src_len;
282 frh->tos = rule4->tos;
284 if ((rule4->dst_len &&
285 nla_put_in_addr(skb, FRA_DST, rule4->dst)) ||
287 nla_put_in_addr(skb, FRA_SRC, rule4->src)))
288 goto nla_put_failure;
289 #ifdef CONFIG_IP_ROUTE_CLASSID
290 if (rule4->tclassid &&
291 nla_put_u32(skb, FRA_FLOW, rule4->tclassid))
292 goto nla_put_failure;
300 static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
302 return nla_total_size(4) /* dst */
303 + nla_total_size(4) /* src */
304 + nla_total_size(4); /* flow */
307 static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
309 rt_cache_flush(ops->fro_net);
312 static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = {
314 .rule_size = sizeof(struct fib4_rule),
315 .addr_size = sizeof(u32),
316 .action = fib4_rule_action,
317 .suppress = fib4_rule_suppress,
318 .match = fib4_rule_match,
319 .configure = fib4_rule_configure,
320 .delete = fib4_rule_delete,
321 .compare = fib4_rule_compare,
322 .fill = fib4_rule_fill,
323 .nlmsg_payload = fib4_rule_nlmsg_payload,
324 .flush_cache = fib4_rule_flush_cache,
325 .nlgroup = RTNLGRP_IPV4_RULE,
326 .policy = fib4_rule_policy,
327 .owner = THIS_MODULE,
330 static int fib_default_rules_init(struct fib_rules_ops *ops)
334 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0);
337 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
340 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
346 int __net_init fib4_rules_init(struct net *net)
349 struct fib_rules_ops *ops;
351 ops = fib_rules_register(&fib4_rules_ops_template, net);
355 err = fib_default_rules_init(ops);
358 net->ipv4.rules_ops = ops;
359 net->ipv4.fib_has_custom_rules = false;
363 /* also cleans all rules already added */
364 fib_rules_unregister(ops);
368 void __net_exit fib4_rules_exit(struct net *net)
370 fib_rules_unregister(net->ipv4.rules_ops);