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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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.
5 *
6 * IPv4 Forwarding Information Base: policy rules.
7 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
Eric Dumazet6a31d2a2010-10-04 20:00:18 +00009 * Thomas Graf <tgraf@suug.ch>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 *
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.
15 *
16 * Fixes:
Eric Dumazet6a31d2a2010-10-04 20:00:18 +000017 * Rani Assaf : local_rule cannot be deleted
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 * Marc Boucher : routing by fwmark
19 */
20
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/types.h>
22#include <linux/kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/netdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/netlink.h>
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070025#include <linux/inetdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/init.h>
Robert Olsson7b204af2006-03-20 17:18:53 -080027#include <linux/list.h>
28#include <linux/rcupdate.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <net/ip.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <net/route.h>
31#include <net/tcp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <net/ip_fib.h>
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070033#include <net/fib_rules.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Eric Dumazet6a31d2a2010-10-04 20:00:18 +000035struct fib4_rule {
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070036 struct fib_rule common;
37 u8 dst_len;
38 u8 src_len;
39 u8 tos;
Al Viro81f7bf62006-09-27 18:40:00 -070040 __be32 src;
41 __be32 srcmask;
42 __be32 dst;
43 __be32 dstmask;
Linus Torvalds1da177e2005-04-16 15:20:36 -070044#ifdef CONFIG_NET_CLS_ROUTE
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070045 u32 tclassid;
Linus Torvalds1da177e2005-04-16 15:20:36 -070046#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070047};
48
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070049#ifdef CONFIG_NET_CLS_ROUTE
50u32 fib_rules_tclass(struct fib_result *res)
Linus Torvalds1da177e2005-04-16 15:20:36 -070051{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070052 return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;
53}
Linus Torvalds1da177e2005-04-16 15:20:36 -070054#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
Denis V. Lunevda0e28c2008-01-21 17:31:55 -080056int fib_lookup(struct net *net, struct flowi *flp, struct fib_result *res)
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070057{
58 struct fib_lookup_arg arg = {
59 .result = res,
Eric Dumazetebc0ffa2010-10-05 10:41:36 +000060 .flags = FIB_LOOKUP_NOREF,
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070061 };
62 int err;
63
Denis V. Lunevda0e28c2008-01-21 17:31:55 -080064 err = fib_rules_lookup(net->ipv4.rules_ops, flp, 0, &arg);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070065 res->r = arg.rule;
66
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 return err;
68}
69
Adrian Bunk8ce11e62006-08-07 21:50:48 -070070static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
71 int flags, struct fib_lookup_arg *arg)
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070072{
73 int err = -EAGAIN;
74 struct fib_table *tbl;
75
76 switch (rule->action) {
77 case FR_ACT_TO_TBL:
78 break;
79
80 case FR_ACT_UNREACHABLE:
81 err = -ENETUNREACH;
82 goto errout;
83
84 case FR_ACT_PROHIBIT:
85 err = -EACCES;
86 goto errout;
87
88 case FR_ACT_BLACKHOLE:
89 default:
90 err = -EINVAL;
91 goto errout;
92 }
93
Eric Dumazet6a31d2a2010-10-04 20:00:18 +000094 tbl = fib_get_table(rule->fr_net, rule->table);
95 if (!tbl)
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070096 goto errout;
97
Eric Dumazetebc0ffa2010-10-05 10:41:36 +000098 err = fib_table_lookup(tbl, flp, (struct fib_result *) arg->result, arg->flags);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070099 if (err > 0)
100 err = -EAGAIN;
101errout:
102 return err;
103}
104
105
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700106static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
107{
108 struct fib4_rule *r = (struct fib4_rule *) rule;
Al Viro81f7bf62006-09-27 18:40:00 -0700109 __be32 daddr = fl->fl4_dst;
110 __be32 saddr = fl->fl4_src;
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700111
112 if (((saddr ^ r->src) & r->srcmask) ||
113 ((daddr ^ r->dst) & r->dstmask))
114 return 0;
115
116 if (r->tos && (r->tos != fl->fl4_tos))
117 return 0;
118
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700119 return 1;
120}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
Denis V. Lunev8ad49422008-01-10 03:24:11 -0800122static struct fib_table *fib_empty_table(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123{
Patrick McHardy2dfe55b2006-08-10 23:08:33 -0700124 u32 id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
126 for (id = 1; id <= RT_TABLE_MAX; id++)
Denis V. Lunev8ad49422008-01-10 03:24:11 -0800127 if (fib_get_table(net, id) == NULL)
128 return fib_new_table(net, id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 return NULL;
130}
131
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700132static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
Thomas Graf1f6c9552006-11-09 15:22:48 -0800133 FRA_GENERIC_POLICY,
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700134 [FRA_FLOW] = { .type = NLA_U32 },
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135};
136
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700137static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
Rami Rosen8b3521e2009-05-11 05:52:49 +0000138 struct fib_rule_hdr *frh,
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700139 struct nlattr **tb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140{
YOSHIFUJI Hideaki3b1e0a62008-03-26 02:26:21 +0900141 struct net *net = sock_net(skb->sk);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700142 int err = -EINVAL;
143 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
Thomas Grafe1701c62007-03-24 12:46:02 -0700145 if (frh->tos & ~IPTOS_TOS_MASK)
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700146 goto errout;
147
148 if (rule->table == RT_TABLE_UNSPEC) {
149 if (rule->action == FR_ACT_TO_TBL) {
150 struct fib_table *table;
151
Denis V. Luneve4e49712008-01-10 03:27:51 -0800152 table = fib_empty_table(net);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700153 if (table == NULL) {
154 err = -ENOBUFS;
155 goto errout;
156 }
157
158 rule->table = table->tb_id;
159 }
160 }
161
Thomas Grafe1701c62007-03-24 12:46:02 -0700162 if (frh->src_len)
Al Viro45d60b92006-09-27 18:40:27 -0700163 rule4->src = nla_get_be32(tb[FRA_SRC]);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700164
Thomas Grafe1701c62007-03-24 12:46:02 -0700165 if (frh->dst_len)
Al Viro45d60b92006-09-27 18:40:27 -0700166 rule4->dst = nla_get_be32(tb[FRA_DST]);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700167
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168#ifdef CONFIG_NET_CLS_ROUTE
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700169 if (tb[FRA_FLOW])
170 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700173 rule4->src_len = frh->src_len;
174 rule4->srcmask = inet_make_mask(rule4->src_len);
175 rule4->dst_len = frh->dst_len;
176 rule4->dstmask = inet_make_mask(rule4->dst_len);
177 rule4->tos = frh->tos;
178
179 err = 0;
180errout:
181 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182}
183
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700184static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
185 struct nlattr **tb)
Patrick McHardya5cdc032006-03-23 01:16:06 -0800186{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700187 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
Patrick McHardya5cdc032006-03-23 01:16:06 -0800188
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700189 if (frh->src_len && (rule4->src_len != frh->src_len))
190 return 0;
191
192 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
193 return 0;
194
195 if (frh->tos && (rule4->tos != frh->tos))
196 return 0;
197
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700198#ifdef CONFIG_NET_CLS_ROUTE
199 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
200 return 0;
201#endif
202
Thomas Grafe1701c62007-03-24 12:46:02 -0700203 if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC])))
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700204 return 0;
205
Thomas Grafe1701c62007-03-24 12:46:02 -0700206 if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST])))
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700207 return 0;
208
209 return 1;
210}
211
212static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
Rami Rosen04af8cf2009-05-20 17:26:23 -0700213 struct fib_rule_hdr *frh)
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700214{
215 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
216
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700217 frh->dst_len = rule4->dst_len;
218 frh->src_len = rule4->src_len;
219 frh->tos = rule4->tos;
220
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700221 if (rule4->dst_len)
Al Viro45d60b92006-09-27 18:40:27 -0700222 NLA_PUT_BE32(skb, FRA_DST, rule4->dst);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700223
224 if (rule4->src_len)
Al Viro45d60b92006-09-27 18:40:27 -0700225 NLA_PUT_BE32(skb, FRA_SRC, rule4->src);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700226
227#ifdef CONFIG_NET_CLS_ROUTE
228 if (rule4->tclassid)
229 NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid);
230#endif
231 return 0;
232
233nla_put_failure:
234 return -ENOBUFS;
235}
236
Thomas Graf339bf982006-11-10 14:10:15 -0800237static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
238{
239 return nla_total_size(4) /* dst */
240 + nla_total_size(4) /* src */
241 + nla_total_size(4); /* flow */
242}
243
Denis V. Lunevae299fc2008-07-05 19:01:28 -0700244static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
Thomas Graf73417f62007-03-27 13:56:52 -0700245{
Denis V. Lunevae299fc2008-07-05 19:01:28 -0700246 rt_cache_flush(ops->fro_net, -1);
Thomas Graf73417f62007-03-27 13:56:52 -0700247}
248
Patrick McHardy3d0c9c42010-04-26 16:02:04 +0200249static const struct fib_rules_ops __net_initdata fib4_rules_ops_template = {
Patrick McHardy25239ce2010-04-26 16:02:05 +0200250 .family = AF_INET,
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700251 .rule_size = sizeof(struct fib4_rule),
Thomas Grafe1701c62007-03-24 12:46:02 -0700252 .addr_size = sizeof(u32),
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700253 .action = fib4_rule_action,
254 .match = fib4_rule_match,
255 .configure = fib4_rule_configure,
256 .compare = fib4_rule_compare,
257 .fill = fib4_rule_fill,
Patrick McHardyd8a566b2010-04-13 05:03:15 +0000258 .default_pref = fib_default_rule_pref,
Thomas Graf339bf982006-11-10 14:10:15 -0800259 .nlmsg_payload = fib4_rule_nlmsg_payload,
Thomas Graf73417f62007-03-27 13:56:52 -0700260 .flush_cache = fib4_rule_flush_cache,
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700261 .nlgroup = RTNLGRP_IPV4_RULE,
262 .policy = fib4_rule_policy,
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700263 .owner = THIS_MODULE,
264};
265
Denis V. Luneve4e49712008-01-10 03:27:51 -0800266static int fib_default_rules_init(struct fib_rules_ops *ops)
Denis V. Lunev2994c632007-11-10 22:12:03 -0800267{
268 int err;
269
Patrick McHardy5adef182009-12-03 01:25:57 +0000270 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0);
Denis V. Lunev2994c632007-11-10 22:12:03 -0800271 if (err < 0)
272 return err;
Denis V. Luneve4e49712008-01-10 03:27:51 -0800273 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
Denis V. Lunev2994c632007-11-10 22:12:03 -0800274 if (err < 0)
275 return err;
Denis V. Luneve4e49712008-01-10 03:27:51 -0800276 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
Denis V. Lunev2994c632007-11-10 22:12:03 -0800277 if (err < 0)
278 return err;
279 return 0;
280}
281
Denis V. Lunev7b1a74f2008-01-10 03:22:17 -0800282int __net_init fib4_rules_init(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283{
Denis V. Lunevdbb50162008-01-10 03:21:49 -0800284 int err;
Denis V. Luneve4e49712008-01-10 03:27:51 -0800285 struct fib_rules_ops *ops;
Denis V. Lunevdbb50162008-01-10 03:21:49 -0800286
Eric W. Biedermane9c51582009-12-03 12:22:55 -0800287 ops = fib_rules_register(&fib4_rules_ops_template, net);
288 if (IS_ERR(ops))
289 return PTR_ERR(ops);
Denis V. Luneve4e49712008-01-10 03:27:51 -0800290
291 err = fib_default_rules_init(ops);
Denis V. Lunevdbb50162008-01-10 03:21:49 -0800292 if (err < 0)
293 goto fail;
Denis V. Luneve4e49712008-01-10 03:27:51 -0800294 net->ipv4.rules_ops = ops;
Denis V. Lunevdbb50162008-01-10 03:21:49 -0800295 return 0;
296
297fail:
298 /* also cleans all rules already added */
Denis V. Lunev9e3a5482008-01-20 16:46:41 -0800299 fib_rules_unregister(ops);
Denis V. Lunevdbb50162008-01-10 03:21:49 -0800300 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301}
Denis V. Lunev7b1a74f2008-01-10 03:22:17 -0800302
303void __net_exit fib4_rules_exit(struct net *net)
304{
Denis V. Lunev9e3a5482008-01-20 16:46:41 -0800305 fib_rules_unregister(net->ipv4.rules_ops);
Denis V. Lunev7b1a74f2008-01-10 03:22:17 -0800306}