blob: 33083ad52e9ff2d0678f9a2914c230a98b1a40d5 [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 -070035static struct fib_rules_ops fib4_rules_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070037struct fib4_rule
Linus Torvalds1da177e2005-04-16 15:20:36 -070038{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070039 struct fib_rule common;
40 u8 dst_len;
41 u8 src_len;
42 u8 tos;
Al Viro81f7bf62006-09-27 18:40:00 -070043 __be32 src;
44 __be32 srcmask;
45 __be32 dst;
46 __be32 dstmask;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#ifdef CONFIG_NET_CLS_ROUTE
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070048 u32 tclassid;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070050};
51
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070052static struct fib4_rule default_rule = {
53 .common = {
54 .refcnt = ATOMIC_INIT(2),
55 .pref = 0x7FFF,
56 .table = RT_TABLE_DEFAULT,
57 .action = FR_ACT_TO_TBL,
58 },
Linus Torvalds1da177e2005-04-16 15:20:36 -070059};
60
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070061static struct fib4_rule main_rule = {
62 .common = {
63 .refcnt = ATOMIC_INIT(2),
64 .pref = 0x7FFE,
65 .table = RT_TABLE_MAIN,
66 .action = FR_ACT_TO_TBL,
67 },
Linus Torvalds1da177e2005-04-16 15:20:36 -070068};
69
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070070static struct fib4_rule local_rule = {
71 .common = {
72 .refcnt = ATOMIC_INIT(2),
73 .table = RT_TABLE_LOCAL,
74 .action = FR_ACT_TO_TBL,
75 .flags = FIB_RULE_PERMANENT,
76 },
Linus Torvalds1da177e2005-04-16 15:20:36 -070077};
78
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070079static LIST_HEAD(fib4_rules);
Robert Olsson7b204af2006-03-20 17:18:53 -080080
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070081#ifdef CONFIG_NET_CLS_ROUTE
82u32 fib_rules_tclass(struct fib_result *res)
Linus Torvalds1da177e2005-04-16 15:20:36 -070083{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070084 return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;
85}
Linus Torvalds1da177e2005-04-16 15:20:36 -070086#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
Thomas Grafe1ef4bf2006-08-04 03:39:22 -070088int fib_lookup(struct flowi *flp, struct fib_result *res)
89{
90 struct fib_lookup_arg arg = {
91 .result = res,
92 };
93 int err;
94
95 err = fib_rules_lookup(&fib4_rules_ops, flp, 0, &arg);
96 res->r = arg.rule;
97
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 return err;
99}
100
Adrian Bunk8ce11e62006-08-07 21:50:48 -0700101static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
102 int flags, struct fib_lookup_arg *arg)
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700103{
104 int err = -EAGAIN;
105 struct fib_table *tbl;
106
107 switch (rule->action) {
108 case FR_ACT_TO_TBL:
109 break;
110
111 case FR_ACT_UNREACHABLE:
112 err = -ENETUNREACH;
113 goto errout;
114
115 case FR_ACT_PROHIBIT:
116 err = -EACCES;
117 goto errout;
118
119 case FR_ACT_BLACKHOLE:
120 default:
121 err = -EINVAL;
122 goto errout;
123 }
124
125 if ((tbl = fib_get_table(rule->table)) == NULL)
126 goto errout;
127
128 err = tbl->tb_lookup(tbl, flp, (struct fib_result *) arg->result);
129 if (err > 0)
130 err = -EAGAIN;
131errout:
132 return err;
133}
134
135
136void fib_select_default(const struct flowi *flp, struct fib_result *res)
137{
138 if (res->r && res->r->action == FR_ACT_TO_TBL &&
139 FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) {
140 struct fib_table *tb;
141 if ((tb = fib_get_table(res->r->table)) != NULL)
142 tb->tb_select_default(tb, flp, res);
143 }
144}
145
146static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
147{
148 struct fib4_rule *r = (struct fib4_rule *) rule;
Al Viro81f7bf62006-09-27 18:40:00 -0700149 __be32 daddr = fl->fl4_dst;
150 __be32 saddr = fl->fl4_src;
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700151
152 if (((saddr ^ r->src) & r->srcmask) ||
153 ((daddr ^ r->dst) & r->dstmask))
154 return 0;
155
156 if (r->tos && (r->tos != fl->fl4_tos))
157 return 0;
158
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700159 return 1;
160}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
162static struct fib_table *fib_empty_table(void)
163{
Patrick McHardy2dfe55b2006-08-10 23:08:33 -0700164 u32 id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165
166 for (id = 1; id <= RT_TABLE_MAX; id++)
Patrick McHardy1af5a8c2006-08-10 23:10:46 -0700167 if (fib_get_table(id) == NULL)
168 return fib_new_table(id);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 return NULL;
170}
171
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700172static struct nla_policy fib4_rule_policy[FRA_MAX+1] __read_mostly = {
Thomas Graf1f6c9552006-11-09 15:22:48 -0800173 FRA_GENERIC_POLICY,
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700174 [FRA_FLOW] = { .type = NLA_U32 },
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175};
176
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700177static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
178 struct nlmsghdr *nlh, struct fib_rule_hdr *frh,
179 struct nlattr **tb)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700181 int err = -EINVAL;
182 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
Thomas Grafe1701c62007-03-24 12:46:02 -0700184 if (frh->tos & ~IPTOS_TOS_MASK)
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700185 goto errout;
186
187 if (rule->table == RT_TABLE_UNSPEC) {
188 if (rule->action == FR_ACT_TO_TBL) {
189 struct fib_table *table;
190
191 table = fib_empty_table();
192 if (table == NULL) {
193 err = -ENOBUFS;
194 goto errout;
195 }
196
197 rule->table = table->tb_id;
198 }
199 }
200
Thomas Grafe1701c62007-03-24 12:46:02 -0700201 if (frh->src_len)
Al Viro45d60b92006-09-27 18:40:27 -0700202 rule4->src = nla_get_be32(tb[FRA_SRC]);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700203
Thomas Grafe1701c62007-03-24 12:46:02 -0700204 if (frh->dst_len)
Al Viro45d60b92006-09-27 18:40:27 -0700205 rule4->dst = nla_get_be32(tb[FRA_DST]);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700206
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207#ifdef CONFIG_NET_CLS_ROUTE
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700208 if (tb[FRA_FLOW])
209 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700212 rule4->src_len = frh->src_len;
213 rule4->srcmask = inet_make_mask(rule4->src_len);
214 rule4->dst_len = frh->dst_len;
215 rule4->dstmask = inet_make_mask(rule4->dst_len);
216 rule4->tos = frh->tos;
217
218 err = 0;
219errout:
220 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221}
222
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700223static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
224 struct nlattr **tb)
Patrick McHardya5cdc032006-03-23 01:16:06 -0800225{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700226 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
Patrick McHardya5cdc032006-03-23 01:16:06 -0800227
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700228 if (frh->src_len && (rule4->src_len != frh->src_len))
229 return 0;
230
231 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
232 return 0;
233
234 if (frh->tos && (rule4->tos != frh->tos))
235 return 0;
236
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700237#ifdef CONFIG_NET_CLS_ROUTE
238 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
239 return 0;
240#endif
241
Thomas Grafe1701c62007-03-24 12:46:02 -0700242 if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC])))
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700243 return 0;
244
Thomas Grafe1701c62007-03-24 12:46:02 -0700245 if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST])))
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700246 return 0;
247
248 return 1;
249}
250
251static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
252 struct nlmsghdr *nlh, struct fib_rule_hdr *frh)
253{
254 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
255
256 frh->family = AF_INET;
257 frh->dst_len = rule4->dst_len;
258 frh->src_len = rule4->src_len;
259 frh->tos = rule4->tos;
260
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700261 if (rule4->dst_len)
Al Viro45d60b92006-09-27 18:40:27 -0700262 NLA_PUT_BE32(skb, FRA_DST, rule4->dst);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700263
264 if (rule4->src_len)
Al Viro45d60b92006-09-27 18:40:27 -0700265 NLA_PUT_BE32(skb, FRA_SRC, rule4->src);
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700266
267#ifdef CONFIG_NET_CLS_ROUTE
268 if (rule4->tclassid)
269 NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid);
270#endif
271 return 0;
272
273nla_put_failure:
274 return -ENOBUFS;
275}
276
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700277static u32 fib4_rule_default_pref(void)
278{
279 struct list_head *pos;
280 struct fib_rule *rule;
281
282 if (!list_empty(&fib4_rules)) {
283 pos = fib4_rules.next;
284 if (pos->next != &fib4_rules) {
285 rule = list_entry(pos->next, struct fib_rule, list);
286 if (rule->pref)
287 return rule->pref - 1;
288 }
Patrick McHardya5cdc032006-03-23 01:16:06 -0800289 }
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700290
291 return 0;
Patrick McHardya5cdc032006-03-23 01:16:06 -0800292}
293
Thomas Graf339bf982006-11-10 14:10:15 -0800294static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
295{
296 return nla_total_size(4) /* dst */
297 + nla_total_size(4) /* src */
298 + nla_total_size(4); /* flow */
299}
300
Thomas Graf73417f62007-03-27 13:56:52 -0700301static void fib4_rule_flush_cache(void)
302{
Thomas Graf4b19ca42007-03-28 14:18:52 -0700303 rt_cache_flush(-1);
Thomas Graf73417f62007-03-27 13:56:52 -0700304}
305
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700306static struct fib_rules_ops fib4_rules_ops = {
307 .family = AF_INET,
308 .rule_size = sizeof(struct fib4_rule),
Thomas Grafe1701c62007-03-24 12:46:02 -0700309 .addr_size = sizeof(u32),
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700310 .action = fib4_rule_action,
311 .match = fib4_rule_match,
312 .configure = fib4_rule_configure,
313 .compare = fib4_rule_compare,
314 .fill = fib4_rule_fill,
315 .default_pref = fib4_rule_default_pref,
Thomas Graf339bf982006-11-10 14:10:15 -0800316 .nlmsg_payload = fib4_rule_nlmsg_payload,
Thomas Graf73417f62007-03-27 13:56:52 -0700317 .flush_cache = fib4_rule_flush_cache,
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700318 .nlgroup = RTNLGRP_IPV4_RULE,
319 .policy = fib4_rule_policy,
320 .rules_list = &fib4_rules,
321 .owner = THIS_MODULE,
322};
323
324void __init fib4_rules_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325{
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700326 list_add_tail(&local_rule.common.list, &fib4_rules);
327 list_add_tail(&main_rule.common.list, &fib4_rules);
328 list_add_tail(&default_rule.common.list, &fib4_rules);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329
Thomas Grafe1ef4bf2006-08-04 03:39:22 -0700330 fib_rules_register(&fib4_rules_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331}