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, struct fib_result *res)
52 struct fib_lookup_arg arg = {
54 .flags = FIB_LOOKUP_NOREF,
58 err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg);
59 #ifdef CONFIG_IP_ROUTE_CLASSID
61 res->tclassid = ((struct fib4_rule *)arg.rule)->tclassid;
71 EXPORT_SYMBOL_GPL(__fib_lookup);
73 static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
74 int flags, struct fib_lookup_arg *arg)
77 struct fib_table *tbl;
79 switch (rule->action) {
83 case FR_ACT_UNREACHABLE:
89 case FR_ACT_BLACKHOLE:
96 tbl = fib_get_table(rule->fr_net, rule->table);
98 err = fib_table_lookup(tbl, &flp->u.ip4,
99 (struct fib_result *)arg->result,
106 static bool fib4_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)
108 struct fib_result *result = (struct fib_result *) arg->result;
109 struct net_device *dev = NULL;
112 dev = result->fi->fib_dev;
114 /* do not accept result if the route does
115 * not meet the required prefix length
117 if (result->prefixlen <= rule->suppress_prefixlen)
120 /* do not accept result if the route uses a device
121 * belonging to a forbidden interface group
123 if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
129 if (!(arg->flags & FIB_LOOKUP_NOREF))
130 fib_info_put(result->fi);
134 static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
136 struct fib4_rule *r = (struct fib4_rule *) rule;
137 struct flowi4 *fl4 = &fl->u.ip4;
138 __be32 daddr = fl4->daddr;
139 __be32 saddr = fl4->saddr;
141 if (((saddr ^ r->src) & r->srcmask) ||
142 ((daddr ^ r->dst) & r->dstmask))
145 if (r->tos && (r->tos != fl4->flowi4_tos))
151 static struct fib_table *fib_empty_table(struct net *net)
155 for (id = 1; id <= RT_TABLE_MAX; id++)
156 if (!fib_get_table(net, id))
157 return fib_new_table(net, id);
161 static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
163 [FRA_FLOW] = { .type = NLA_U32 },
166 static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
167 struct fib_rule_hdr *frh,
170 struct net *net = sock_net(skb->sk);
172 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
174 if (frh->tos & ~IPTOS_TOS_MASK)
177 /* split local/main if they are not already split */
178 err = fib_unmerge(net);
182 if (rule->table == RT_TABLE_UNSPEC) {
183 if (rule->action == FR_ACT_TO_TBL) {
184 struct fib_table *table;
186 table = fib_empty_table(net);
192 rule->table = table->tb_id;
197 rule4->src = nla_get_in_addr(tb[FRA_SRC]);
200 rule4->dst = nla_get_in_addr(tb[FRA_DST]);
202 #ifdef CONFIG_IP_ROUTE_CLASSID
204 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
206 net->ipv4.fib_num_tclassid_users++;
210 rule4->src_len = frh->src_len;
211 rule4->srcmask = inet_make_mask(rule4->src_len);
212 rule4->dst_len = frh->dst_len;
213 rule4->dstmask = inet_make_mask(rule4->dst_len);
214 rule4->tos = frh->tos;
216 net->ipv4.fib_has_custom_rules = true;
217 fib_flush_external(rule->fr_net);
224 static int fib4_rule_delete(struct fib_rule *rule)
226 struct net *net = rule->fr_net;
229 /* split local/main if they are not already split */
230 err = fib_unmerge(net);
234 #ifdef CONFIG_IP_ROUTE_CLASSID
235 if (((struct fib4_rule *)rule)->tclassid)
236 net->ipv4.fib_num_tclassid_users--;
238 net->ipv4.fib_has_custom_rules = true;
239 fib_flush_external(rule->fr_net);
244 static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
247 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
249 if (frh->src_len && (rule4->src_len != frh->src_len))
252 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
255 if (frh->tos && (rule4->tos != frh->tos))
258 #ifdef CONFIG_IP_ROUTE_CLASSID
259 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
263 if (frh->src_len && (rule4->src != nla_get_in_addr(tb[FRA_SRC])))
266 if (frh->dst_len && (rule4->dst != nla_get_in_addr(tb[FRA_DST])))
272 static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
273 struct fib_rule_hdr *frh)
275 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
277 frh->dst_len = rule4->dst_len;
278 frh->src_len = rule4->src_len;
279 frh->tos = rule4->tos;
281 if ((rule4->dst_len &&
282 nla_put_in_addr(skb, FRA_DST, rule4->dst)) ||
284 nla_put_in_addr(skb, FRA_SRC, rule4->src)))
285 goto nla_put_failure;
286 #ifdef CONFIG_IP_ROUTE_CLASSID
287 if (rule4->tclassid &&
288 nla_put_u32(skb, FRA_FLOW, rule4->tclassid))
289 goto nla_put_failure;
297 static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
299 return nla_total_size(4) /* dst */
300 + nla_total_size(4) /* src */
301 + nla_total_size(4); /* flow */
304 static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
306 rt_cache_flush(ops->fro_net);
309 static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = {
311 .rule_size = sizeof(struct fib4_rule),
312 .addr_size = sizeof(u32),
313 .action = fib4_rule_action,
314 .suppress = fib4_rule_suppress,
315 .match = fib4_rule_match,
316 .configure = fib4_rule_configure,
317 .delete = fib4_rule_delete,
318 .compare = fib4_rule_compare,
319 .fill = fib4_rule_fill,
320 .default_pref = fib_default_rule_pref,
321 .nlmsg_payload = fib4_rule_nlmsg_payload,
322 .flush_cache = fib4_rule_flush_cache,
323 .nlgroup = RTNLGRP_IPV4_RULE,
324 .policy = fib4_rule_policy,
325 .owner = THIS_MODULE,
328 static int fib_default_rules_init(struct fib_rules_ops *ops)
332 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0);
335 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
338 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
344 int __net_init fib4_rules_init(struct net *net)
347 struct fib_rules_ops *ops;
349 ops = fib_rules_register(&fib4_rules_ops_template, net);
353 err = fib_default_rules_init(ops);
356 net->ipv4.rules_ops = ops;
357 net->ipv4.fib_has_custom_rules = false;
361 /* also cleans all rules already added */
362 fib_rules_unregister(ops);
366 void __net_exit fib4_rules_exit(struct net *net)
368 fib_rules_unregister(net->ipv4.rules_ops);