blob: 19274d01afa4a36c3777b5ff34816fa63783734a [file] [log] [blame]
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>
Thomas Grafe1ef4bf2006-08-04 03:39:22 -07009 * 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:
17 * Rani Assaf : local_rule cannot be deleted
18 * 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
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070035struct fib4_rule
Linus Torvalds1da177e2005-04-16 15:20:36 -070036{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070037 struct fib_rule common;
38 u8 dst_len;
39 u8 src_len;
40 u8 tos;
Al Viro81f7bf62006-09-27 18:40:00 -070041 __be32 src;
42 __be32 srcmask;
43 __be32 dst;
44 __be32 dstmask;
Linus Torvalds1da177e2005-04-16 15:20:36 -070045#ifdef CONFIG_NET_CLS_ROUTE
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070046 u32 tclassid;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070048};
49
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070050#ifdef CONFIG_NET_CLS_ROUTE
51u32 fib_rules_tclass(struct fib_result *res)
Linus Torvalds1da177e2005-04-16 15:20:36 -070052{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070053 return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;
54}
Linus Torvalds1da177e2005-04-16 15:20:36 -070055#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
Denis V. Lunevda0e28c2008-01-21 17:31:55 -080057int fib_lookup(struct net *net, struct flowi *flp, struct fib_result *res)
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070058{
59 struct fib_lookup_arg arg = {
60 .result = res,
61 };
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
Denis V. Lunev51314a12008-01-20 16:47:09 -080094 if ((tbl = fib_get_table(rule->fr_net, rule->table)) == NULL)
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070095 goto errout;
96
97 err = tbl->tb_lookup(tbl, flp, (struct fib_result *) arg->result);
98 if (err > 0)
99 err = -EAGAIN;
100errout:
101 return err;
102}
103
104
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700105static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
106{
107 struct fib4_rule *r = (struct fib4_rule *) rule;
Al Viro81f7bf62006-09-27 18:40:00 -0700108 __be32 daddr = fl->fl4_dst;
109 __be32 saddr = fl->fl4_src;
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700110
111 if (((saddr ^ r->src) & r->srcmask) ||
112 ((daddr ^ r->dst) & r->dstmask))
113 return 0;
114
115 if (r->tos && (r->tos != fl->fl4_tos))
116 return 0;
117
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700118 return 1;
119}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
Denis V. Lunev8ad49422008-01-10 03:24:11 -0800121static struct fib_table *fib_empty_table(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122{
Patrick McHardy2dfe55b2006-08-10 23:08:33 -0700123 u32 id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
125 for (id = 1; id <= RT_TABLE_MAX; id++)
Denis V. Lunev8ad49422008-01-10 03:24:11 -0800126 if (fib_get_table(net, id) == NULL)
127 return fib_new_table(net, id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 return NULL;
129}
130
Patrick McHardyef7c79e2007-06-05 12:38:30 -0700131static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
Thomas Graf1f6c9552006-11-09 15:22:48 -0800132 FRA_GENERIC_POLICY,
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700133 [FRA_FLOW] = { .type = NLA_U32 },
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134};
135
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700136static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
137 struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
138 struct nlattr **tb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139{
Denis V. Luneve4e49712008-01-10 03:27:51 -0800140 struct net *net = skb->sk->sk_net;
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700141 int err = -EINVAL;
142 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
Thomas Grafe1701c62007-03-24 12:46:02 -0700144 if (frh->tos & ~IPTOS_TOS_MASK)
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700145 goto errout;
146
147 if (rule->table == RT_TABLE_UNSPEC) {
148 if (rule->action == FR_ACT_TO_TBL) {
149 struct fib_table *table;
150
Denis V. Luneve4e49712008-01-10 03:27:51 -0800151 table = fib_empty_table(net);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700152 if (table == NULL) {
153 err = -ENOBUFS;
154 goto errout;
155 }
156
157 rule->table = table->tb_id;
158 }
159 }
160
Thomas Grafe1701c62007-03-24 12:46:02 -0700161 if (frh->src_len)
Al Viro45d60b92006-09-27 18:40:27 -0700162 rule4->src = nla_get_be32(tb[FRA_SRC]);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700163
Thomas Grafe1701c62007-03-24 12:46:02 -0700164 if (frh->dst_len)
Al Viro45d60b92006-09-27 18:40:27 -0700165 rule4->dst = nla_get_be32(tb[FRA_DST]);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700166
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167#ifdef CONFIG_NET_CLS_ROUTE
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700168 if (tb[FRA_FLOW])
169 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700172 rule4->src_len = frh->src_len;
173 rule4->srcmask = inet_make_mask(rule4->src_len);
174 rule4->dst_len = frh->dst_len;
175 rule4->dstmask = inet_make_mask(rule4->dst_len);
176 rule4->tos = frh->tos;
177
178 err = 0;
179errout:
180 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181}
182
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700183static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
184 struct nlattr **tb)
Patrick McHardya5cdc032006-03-23 01:16:06 -0800185{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700186 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
Patrick McHardya5cdc032006-03-23 01:16:06 -0800187
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700188 if (frh->src_len && (rule4->src_len != frh->src_len))
189 return 0;
190
191 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
192 return 0;
193
194 if (frh->tos && (rule4->tos != frh->tos))
195 return 0;
196
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700197#ifdef CONFIG_NET_CLS_ROUTE
198 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
199 return 0;
200#endif
201
Thomas Grafe1701c62007-03-24 12:46:02 -0700202 if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC])))
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700203 return 0;
204
Thomas Grafe1701c62007-03-24 12:46:02 -0700205 if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST])))
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700206 return 0;
207
208 return 1;
209}
210
211static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
212 struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
213{
214 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
215
216 frh->family = AF_INET;
217 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
Denis V. Lunev868d13a2008-01-10 03:18:25 -0800237static u32 fib4_rule_default_pref(struct fib_rules_ops *ops)
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700238{
239 struct list_head *pos;
240 struct fib_rule *rule;
241
Denis V. Luneve4e49712008-01-10 03:27:51 -0800242 if (!list_empty(&ops->rules_list)) {
243 pos = ops->rules_list.next;
244 if (pos->next != &ops->rules_list) {
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700245 rule = list_entry(pos->next, struct fib_rule, list);
246 if (rule->pref)
247 return rule->pref - 1;
248 }
Patrick McHardya5cdc032006-03-23 01:16:06 -0800249 }
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700250
251 return 0;
Patrick McHardya5cdc032006-03-23 01:16:06 -0800252}
253
Thomas Graf339bf982006-11-10 14:10:15 -0800254static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
255{
256 return nla_total_size(4) /* dst */
257 + nla_total_size(4) /* src */
258 + nla_total_size(4); /* flow */
259}
260
Thomas Graf73417f62007-03-27 13:56:52 -0700261static void fib4_rule_flush_cache(void)
262{
Thomas Graf4b19ca42007-03-28 14:18:52 -0700263 rt_cache_flush(-1);
Thomas Graf73417f62007-03-27 13:56:52 -0700264}
265
Denis V. Luneve4e49712008-01-10 03:27:51 -0800266static struct fib_rules_ops fib4_rules_ops_template = {
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700267 .family = AF_INET,
268 .rule_size = sizeof(struct fib4_rule),
Thomas Grafe1701c62007-03-24 12:46:02 -0700269 .addr_size = sizeof(u32),
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700270 .action = fib4_rule_action,
271 .match = fib4_rule_match,
272 .configure = fib4_rule_configure,
273 .compare = fib4_rule_compare,
274 .fill = fib4_rule_fill,
275 .default_pref = fib4_rule_default_pref,
Thomas Graf339bf982006-11-10 14:10:15 -0800276 .nlmsg_payload = fib4_rule_nlmsg_payload,
Thomas Graf73417f62007-03-27 13:56:52 -0700277 .flush_cache = fib4_rule_flush_cache,
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700278 .nlgroup = RTNLGRP_IPV4_RULE,
279 .policy = fib4_rule_policy,
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700280 .owner = THIS_MODULE,
281};
282
Denis V. Luneve4e49712008-01-10 03:27:51 -0800283static int fib_default_rules_init(struct fib_rules_ops *ops)
Denis V. Lunev2994c632007-11-10 22:12:03 -0800284{
285 int err;
286
Denis V. Luneve4e49712008-01-10 03:27:51 -0800287 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, FIB_RULE_PERMANENT);
Denis V. Lunev2994c632007-11-10 22:12:03 -0800288 if (err < 0)
289 return err;
Denis V. Luneve4e49712008-01-10 03:27:51 -0800290 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
Denis V. Lunev2994c632007-11-10 22:12:03 -0800291 if (err < 0)
292 return err;
Denis V. Luneve4e49712008-01-10 03:27:51 -0800293 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
Denis V. Lunev2994c632007-11-10 22:12:03 -0800294 if (err < 0)
295 return err;
296 return 0;
297}
298
Denis V. Lunev7b1a74f2008-01-10 03:22:17 -0800299int __net_init fib4_rules_init(struct net *net)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300{
Denis V. Lunevdbb50162008-01-10 03:21:49 -0800301 int err;
Denis V. Luneve4e49712008-01-10 03:27:51 -0800302 struct fib_rules_ops *ops;
Denis V. Lunevdbb50162008-01-10 03:21:49 -0800303
Denis V. Luneve4e49712008-01-10 03:27:51 -0800304 ops = kmemdup(&fib4_rules_ops_template, sizeof(*ops), GFP_KERNEL);
305 if (ops == NULL)
306 return -ENOMEM;
307 INIT_LIST_HEAD(&ops->rules_list);
Denis V. Lunev035923832008-01-20 16:46:01 -0800308 ops->fro_net = net;
309
Denis V. Lunev9e3a5482008-01-20 16:46:41 -0800310 fib_rules_register(ops);
Denis V. Luneve4e49712008-01-10 03:27:51 -0800311
312 err = fib_default_rules_init(ops);
Denis V. Lunevdbb50162008-01-10 03:21:49 -0800313 if (err < 0)
314 goto fail;
Denis V. Luneve4e49712008-01-10 03:27:51 -0800315 net->ipv4.rules_ops = ops;
Denis V. Lunevdbb50162008-01-10 03:21:49 -0800316 return 0;
317
318fail:
319 /* also cleans all rules already added */
Denis V. Lunev9e3a5482008-01-20 16:46:41 -0800320 fib_rules_unregister(ops);
Denis V. Luneve4e49712008-01-10 03:27:51 -0800321 kfree(ops);
Denis V. Lunevdbb50162008-01-10 03:21:49 -0800322 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323}
Denis V. Lunev7b1a74f2008-01-10 03:22:17 -0800324
325void __net_exit fib4_rules_exit(struct net *net)
326{
Denis V. Lunev9e3a5482008-01-20 16:46:41 -0800327 fib_rules_unregister(net->ipv4.rules_ops);
Denis V. Luneve4e49712008-01-10 03:27:51 -0800328 kfree(net->ipv4.rules_ops);
Denis V. Lunev7b1a74f2008-01-10 03:22:17 -0800329}