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 #ifdef CONFIG_IP_ROUTE_CLASSID
51 u32 fib_rules_tclass(const struct fib_result *res)
53 return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;
57 int fib_lookup(struct net *net, struct flowi4 *flp, struct fib_result *res)
59 struct fib_lookup_arg arg = {
61 .flags = FIB_LOOKUP_NOREF,
65 err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg);
70 EXPORT_SYMBOL_GPL(fib_lookup);
72 static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
73 int flags, struct fib_lookup_arg *arg)
76 struct fib_table *tbl;
78 switch (rule->action) {
82 case FR_ACT_UNREACHABLE:
90 case FR_ACT_BLACKHOLE:
96 tbl = fib_get_table(rule->fr_net, rule->table);
100 err = fib_table_lookup(tbl, &flp->u.ip4, (struct fib_result *) arg->result, arg->flags);
108 static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
110 struct fib4_rule *r = (struct fib4_rule *) rule;
111 struct flowi4 *fl4 = &fl->u.ip4;
112 __be32 daddr = fl4->daddr;
113 __be32 saddr = fl4->saddr;
115 if (((saddr ^ r->src) & r->srcmask) ||
116 ((daddr ^ r->dst) & r->dstmask))
119 if (r->tos && (r->tos != fl4->flowi4_tos))
125 static struct fib_table *fib_empty_table(struct net *net)
129 for (id = 1; id <= RT_TABLE_MAX; id++)
130 if (fib_get_table(net, id) == NULL)
131 return fib_new_table(net, id);
135 static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
137 [FRA_FLOW] = { .type = NLA_U32 },
140 static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
141 struct fib_rule_hdr *frh,
144 struct net *net = sock_net(skb->sk);
146 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
148 if (frh->tos & ~IPTOS_TOS_MASK)
151 if (rule->table == RT_TABLE_UNSPEC) {
152 if (rule->action == FR_ACT_TO_TBL) {
153 struct fib_table *table;
155 table = fib_empty_table(net);
161 rule->table = table->tb_id;
166 rule4->src = nla_get_be32(tb[FRA_SRC]);
169 rule4->dst = nla_get_be32(tb[FRA_DST]);
171 #ifdef CONFIG_IP_ROUTE_CLASSID
173 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
176 rule4->src_len = frh->src_len;
177 rule4->srcmask = inet_make_mask(rule4->src_len);
178 rule4->dst_len = frh->dst_len;
179 rule4->dstmask = inet_make_mask(rule4->dst_len);
180 rule4->tos = frh->tos;
187 static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
190 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
192 if (frh->src_len && (rule4->src_len != frh->src_len))
195 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
198 if (frh->tos && (rule4->tos != frh->tos))
201 #ifdef CONFIG_IP_ROUTE_CLASSID
202 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
206 if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC])))
209 if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST])))
215 static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
216 struct fib_rule_hdr *frh)
218 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
220 frh->dst_len = rule4->dst_len;
221 frh->src_len = rule4->src_len;
222 frh->tos = rule4->tos;
224 if ((rule4->dst_len &&
225 nla_put_be32(skb, FRA_DST, rule4->dst)) ||
227 nla_put_be32(skb, FRA_SRC, rule4->src)))
228 goto nla_put_failure;
229 #ifdef CONFIG_IP_ROUTE_CLASSID
230 if (rule4->tclassid &&
231 nla_put_u32(skb, FRA_FLOW, rule4->tclassid))
232 goto nla_put_failure;
240 static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
242 return nla_total_size(4) /* dst */
243 + nla_total_size(4) /* src */
244 + nla_total_size(4); /* flow */
247 static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
249 rt_cache_flush(ops->fro_net, -1);
252 static const struct fib_rules_ops __net_initdata fib4_rules_ops_template = {
254 .rule_size = sizeof(struct fib4_rule),
255 .addr_size = sizeof(u32),
256 .action = fib4_rule_action,
257 .match = fib4_rule_match,
258 .configure = fib4_rule_configure,
259 .compare = fib4_rule_compare,
260 .fill = fib4_rule_fill,
261 .default_pref = fib_default_rule_pref,
262 .nlmsg_payload = fib4_rule_nlmsg_payload,
263 .flush_cache = fib4_rule_flush_cache,
264 .nlgroup = RTNLGRP_IPV4_RULE,
265 .policy = fib4_rule_policy,
266 .owner = THIS_MODULE,
269 static int fib_default_rules_init(struct fib_rules_ops *ops)
273 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0);
276 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
279 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
285 int __net_init fib4_rules_init(struct net *net)
288 struct fib_rules_ops *ops;
290 ops = fib_rules_register(&fib4_rules_ops_template, net);
294 err = fib_default_rules_init(ops);
297 net->ipv4.rules_ops = ops;
301 /* also cleans all rules already added */
302 fib_rules_unregister(ops);
306 void __net_exit fib4_rules_exit(struct net *net)
308 fib_rules_unregister(net->ipv4.rules_ops);