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>
30 #include <net/route.h>
32 #include <net/ip_fib.h>
33 #include <net/fib_rules.h>
37 struct fib_rule common;
45 #ifdef CONFIG_NET_CLS_ROUTE
50 #ifdef CONFIG_NET_CLS_ROUTE
51 u32 fib_rules_tclass(struct fib_result *res)
53 return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;
57 int fib_lookup(struct net *net, struct flowi *flp, struct fib_result *res)
59 struct fib_lookup_arg arg = {
64 err = fib_rules_lookup(net->ipv4.rules_ops, flp, 0, &arg);
70 static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
71 int flags, struct fib_lookup_arg *arg)
74 struct fib_table *tbl;
76 switch (rule->action) {
80 case FR_ACT_UNREACHABLE:
88 case FR_ACT_BLACKHOLE:
94 if ((tbl = fib_get_table(rule->fr_net, rule->table)) == NULL)
97 err = tbl->tb_lookup(tbl, flp, (struct fib_result *) arg->result);
105 void fib_select_default(const struct flowi *flp, struct fib_result *res)
107 if (res->r && res->r->action == FR_ACT_TO_TBL &&
108 FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) {
109 struct fib_table *tb;
110 if ((tb = fib_get_table(&init_net, res->r->table)) != NULL)
111 tb->tb_select_default(tb, flp, res);
115 static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
117 struct fib4_rule *r = (struct fib4_rule *) rule;
118 __be32 daddr = fl->fl4_dst;
119 __be32 saddr = fl->fl4_src;
121 if (((saddr ^ r->src) & r->srcmask) ||
122 ((daddr ^ r->dst) & r->dstmask))
125 if (r->tos && (r->tos != fl->fl4_tos))
131 static struct fib_table *fib_empty_table(struct net *net)
135 for (id = 1; id <= RT_TABLE_MAX; id++)
136 if (fib_get_table(net, id) == NULL)
137 return fib_new_table(net, id);
141 static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
143 [FRA_FLOW] = { .type = NLA_U32 },
146 static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
147 struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
150 struct net *net = skb->sk->sk_net;
152 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
154 if (frh->tos & ~IPTOS_TOS_MASK)
157 if (rule->table == RT_TABLE_UNSPEC) {
158 if (rule->action == FR_ACT_TO_TBL) {
159 struct fib_table *table;
161 table = fib_empty_table(net);
167 rule->table = table->tb_id;
172 rule4->src = nla_get_be32(tb[FRA_SRC]);
175 rule4->dst = nla_get_be32(tb[FRA_DST]);
177 #ifdef CONFIG_NET_CLS_ROUTE
179 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
182 rule4->src_len = frh->src_len;
183 rule4->srcmask = inet_make_mask(rule4->src_len);
184 rule4->dst_len = frh->dst_len;
185 rule4->dstmask = inet_make_mask(rule4->dst_len);
186 rule4->tos = frh->tos;
193 static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
196 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
198 if (frh->src_len && (rule4->src_len != frh->src_len))
201 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
204 if (frh->tos && (rule4->tos != frh->tos))
207 #ifdef CONFIG_NET_CLS_ROUTE
208 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
212 if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC])))
215 if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST])))
221 static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
222 struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
224 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
226 frh->family = AF_INET;
227 frh->dst_len = rule4->dst_len;
228 frh->src_len = rule4->src_len;
229 frh->tos = rule4->tos;
232 NLA_PUT_BE32(skb, FRA_DST, rule4->dst);
235 NLA_PUT_BE32(skb, FRA_SRC, rule4->src);
237 #ifdef CONFIG_NET_CLS_ROUTE
239 NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid);
247 static u32 fib4_rule_default_pref(struct fib_rules_ops *ops)
249 struct list_head *pos;
250 struct fib_rule *rule;
252 if (!list_empty(&ops->rules_list)) {
253 pos = ops->rules_list.next;
254 if (pos->next != &ops->rules_list) {
255 rule = list_entry(pos->next, struct fib_rule, list);
257 return rule->pref - 1;
264 static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
266 return nla_total_size(4) /* dst */
267 + nla_total_size(4) /* src */
268 + nla_total_size(4); /* flow */
271 static void fib4_rule_flush_cache(void)
276 static struct fib_rules_ops fib4_rules_ops_template = {
278 .rule_size = sizeof(struct fib4_rule),
279 .addr_size = sizeof(u32),
280 .action = fib4_rule_action,
281 .match = fib4_rule_match,
282 .configure = fib4_rule_configure,
283 .compare = fib4_rule_compare,
284 .fill = fib4_rule_fill,
285 .default_pref = fib4_rule_default_pref,
286 .nlmsg_payload = fib4_rule_nlmsg_payload,
287 .flush_cache = fib4_rule_flush_cache,
288 .nlgroup = RTNLGRP_IPV4_RULE,
289 .policy = fib4_rule_policy,
290 .owner = THIS_MODULE,
293 static int fib_default_rules_init(struct fib_rules_ops *ops)
297 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, FIB_RULE_PERMANENT);
300 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
303 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
309 int __net_init fib4_rules_init(struct net *net)
312 struct fib_rules_ops *ops;
314 ops = kmemdup(&fib4_rules_ops_template, sizeof(*ops), GFP_KERNEL);
317 INIT_LIST_HEAD(&ops->rules_list);
320 fib_rules_register(ops);
322 err = fib_default_rules_init(ops);
325 net->ipv4.rules_ops = ops;
329 /* also cleans all rules already added */
330 fib_rules_unregister(ops);
335 void __net_exit fib4_rules_exit(struct net *net)
337 fib_rules_unregister(net->ipv4.rules_ops);
338 kfree(net->ipv4.rules_ops);