Merge remote-tracking branch 'xen-tip/linux-next'
[deliverable/linux.git] / net / ipv4 / fib_rules.c
CommitLineData
1da177e4
LT
1/*
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 *
1da177e4 8 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6a31d2a9 9 * Thomas Graf <tgraf@suug.ch>
1da177e4
LT
10 *
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:
6a31d2a9 17 * Rani Assaf : local_rule cannot be deleted
1da177e4
LT
18 * Marc Boucher : routing by fwmark
19 */
20
1da177e4
LT
21#include <linux/types.h>
22#include <linux/kernel.h>
1da177e4 23#include <linux/netdevice.h>
1da177e4 24#include <linux/netlink.h>
e1ef4bf2 25#include <linux/inetdevice.h>
1da177e4 26#include <linux/init.h>
7b204afd
RO
27#include <linux/list.h>
28#include <linux/rcupdate.h>
bc3b2d7f 29#include <linux/export.h>
1da177e4 30#include <net/ip.h>
1da177e4
LT
31#include <net/route.h>
32#include <net/tcp.h>
1da177e4 33#include <net/ip_fib.h>
e1ef4bf2 34#include <net/fib_rules.h>
1da177e4 35
6a31d2a9 36struct fib4_rule {
e1ef4bf2
TG
37 struct fib_rule common;
38 u8 dst_len;
39 u8 src_len;
40 u8 tos;
81f7bf6c
AV
41 __be32 src;
42 __be32 srcmask;
43 __be32 dst;
44 __be32 dstmask;
c7066f70 45#ifdef CONFIG_IP_ROUTE_CLASSID
e1ef4bf2 46 u32 tclassid;
1da177e4 47#endif
1da177e4
LT
48};
49
0eeb075f
AG
50int __fib_lookup(struct net *net, struct flowi4 *flp,
51 struct fib_result *res, unsigned int flags)
e1ef4bf2
TG
52{
53 struct fib_lookup_arg arg = {
54 .result = res,
0eeb075f 55 .flags = flags,
e1ef4bf2
TG
56 };
57 int err;
1da177e4 58
9ee0034b
DA
59 /* update flow if oif or iif point to device enslaved to l3mdev */
60 l3mdev_update_flow(net, flowi4_to_flowi(flp));
61
22bd5b9b 62 err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg);
85b91b03
DM
63#ifdef CONFIG_IP_ROUTE_CLASSID
64 if (arg.rule)
65 res->tclassid = ((struct fib4_rule *)arg.rule)->tclassid;
66 else
67 res->tclassid = 0;
68#endif
49dd18ba
PM
69
70 if (err == -ESRCH)
71 err = -ENETUNREACH;
72
e1ef4bf2
TG
73 return err;
74}
f4530fa5 75EXPORT_SYMBOL_GPL(__fib_lookup);
e1ef4bf2 76
8ce11e6a
AB
77static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
78 int flags, struct fib_lookup_arg *arg)
1da177e4 79{
e1ef4bf2
TG
80 int err = -EAGAIN;
81 struct fib_table *tbl;
96c63fa7 82 u32 tb_id;
e1ef4bf2
TG
83
84 switch (rule->action) {
85 case FR_ACT_TO_TBL:
86 break;
87
88 case FR_ACT_UNREACHABLE:
345e9b54 89 return -ENETUNREACH;
e1ef4bf2
TG
90
91 case FR_ACT_PROHIBIT:
345e9b54 92 return -EACCES;
e1ef4bf2
TG
93
94 case FR_ACT_BLACKHOLE:
95 default:
345e9b54 96 return -EINVAL;
1da177e4 97 }
e1ef4bf2 98
345e9b54
AD
99 rcu_read_lock();
100
96c63fa7
DA
101 tb_id = fib_rule_get_table(rule, arg);
102 tbl = fib_get_table(rule->fr_net, tb_id);
345e9b54
AD
103 if (tbl)
104 err = fib_table_lookup(tbl, &flp->u.ip4,
105 (struct fib_result *)arg->result,
106 arg->flags);
e1ef4bf2 107
345e9b54 108 rcu_read_unlock();
1da177e4
LT
109 return err;
110}
111
7764a45a
ST
112static bool fib4_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)
113{
6ef94cfa 114 struct fib_result *result = (struct fib_result *) arg->result;
673498b8
ST
115 struct net_device *dev = NULL;
116
117 if (result->fi)
118 dev = result->fi->fib_dev;
6ef94cfa 119
7764a45a
ST
120 /* do not accept result if the route does
121 * not meet the required prefix length
122 */
73f5698e 123 if (result->prefixlen <= rule->suppress_prefixlen)
6ef94cfa
ST
124 goto suppress_route;
125
126 /* do not accept result if the route uses a device
127 * belonging to a forbidden interface group
128 */
129 if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
130 goto suppress_route;
131
7764a45a 132 return false;
6ef94cfa
ST
133
134suppress_route:
135 if (!(arg->flags & FIB_LOOKUP_NOREF))
136 fib_info_put(result->fi);
137 return true;
7764a45a 138}
e1ef4bf2 139
e1ef4bf2
TG
140static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
141{
142 struct fib4_rule *r = (struct fib4_rule *) rule;
9ade2286
DM
143 struct flowi4 *fl4 = &fl->u.ip4;
144 __be32 daddr = fl4->daddr;
145 __be32 saddr = fl4->saddr;
e1ef4bf2
TG
146
147 if (((saddr ^ r->src) & r->srcmask) ||
148 ((daddr ^ r->dst) & r->dstmask))
149 return 0;
150
9ade2286 151 if (r->tos && (r->tos != fl4->flowi4_tos))
e1ef4bf2
TG
152 return 0;
153
e1ef4bf2
TG
154 return 1;
155}
1da177e4 156
8ad4942c 157static struct fib_table *fib_empty_table(struct net *net)
1da177e4 158{
2dfe55b4 159 u32 id;
1da177e4
LT
160
161 for (id = 1; id <= RT_TABLE_MAX; id++)
51456b29 162 if (!fib_get_table(net, id))
8ad4942c 163 return fib_new_table(net, id);
1da177e4
LT
164 return NULL;
165}
166
ef7c79ed 167static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
1f6c9557 168 FRA_GENERIC_POLICY,
e1ef4bf2
TG
169 [FRA_FLOW] = { .type = NLA_U32 },
170};
7b204afd 171
e1ef4bf2 172static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
8b3521ee 173 struct fib_rule_hdr *frh,
e1ef4bf2 174 struct nlattr **tb)
1da177e4 175{
3b1e0a65 176 struct net *net = sock_net(skb->sk);
e1ef4bf2
TG
177 int err = -EINVAL;
178 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
1da177e4 179
e1701c68 180 if (frh->tos & ~IPTOS_TOS_MASK)
e1ef4bf2 181 goto errout;
7b204afd 182
0ddcf43d
AD
183 /* split local/main if they are not already split */
184 err = fib_unmerge(net);
185 if (err)
186 goto errout;
187
96c63fa7 188 if (rule->table == RT_TABLE_UNSPEC && !rule->l3mdev) {
e1ef4bf2
TG
189 if (rule->action == FR_ACT_TO_TBL) {
190 struct fib_table *table;
1da177e4 191
e4e4971c 192 table = fib_empty_table(net);
51456b29 193 if (!table) {
e1ef4bf2
TG
194 err = -ENOBUFS;
195 goto errout;
196 }
1da177e4 197
e1ef4bf2 198 rule->table = table->tb_id;
1da177e4
LT
199 }
200 }
201
e1701c68 202 if (frh->src_len)
67b61f6c 203 rule4->src = nla_get_in_addr(tb[FRA_SRC]);
7b204afd 204
e1701c68 205 if (frh->dst_len)
67b61f6c 206 rule4->dst = nla_get_in_addr(tb[FRA_DST]);
7b204afd 207
c7066f70 208#ifdef CONFIG_IP_ROUTE_CLASSID
7a9bc9b8 209 if (tb[FRA_FLOW]) {
e1ef4bf2 210 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
7a9bc9b8 211 if (rule4->tclassid)
f4530fa5 212 net->ipv4.fib_num_tclassid_users++;
7a9bc9b8 213 }
1da177e4
LT
214#endif
215
e1ef4bf2
TG
216 rule4->src_len = frh->src_len;
217 rule4->srcmask = inet_make_mask(rule4->src_len);
218 rule4->dst_len = frh->dst_len;
219 rule4->dstmask = inet_make_mask(rule4->dst_len);
220 rule4->tos = frh->tos;
7b204afd 221
f4530fa5 222 net->ipv4.fib_has_custom_rules = true;
104616e7
SF
223 fib_flush_external(rule->fr_net);
224
e1ef4bf2
TG
225 err = 0;
226errout:
227 return err;
1da177e4
LT
228}
229
0ddcf43d 230static int fib4_rule_delete(struct fib_rule *rule)
7a9bc9b8 231{
f4530fa5 232 struct net *net = rule->fr_net;
0ddcf43d 233 int err;
7a9bc9b8 234
0ddcf43d
AD
235 /* split local/main if they are not already split */
236 err = fib_unmerge(net);
237 if (err)
238 goto errout;
239
240#ifdef CONFIG_IP_ROUTE_CLASSID
241 if (((struct fib4_rule *)rule)->tclassid)
f4530fa5 242 net->ipv4.fib_num_tclassid_users--;
7a9bc9b8 243#endif
f4530fa5 244 net->ipv4.fib_has_custom_rules = true;
104616e7 245 fib_flush_external(rule->fr_net);
0ddcf43d
AD
246errout:
247 return err;
7a9bc9b8
DM
248}
249
e1ef4bf2
TG
250static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
251 struct nlattr **tb)
1da177e4 252{
e1ef4bf2 253 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
1da177e4 254
e1ef4bf2
TG
255 if (frh->src_len && (rule4->src_len != frh->src_len))
256 return 0;
1da177e4 257
e1ef4bf2
TG
258 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
259 return 0;
7b204afd 260
e1ef4bf2
TG
261 if (frh->tos && (rule4->tos != frh->tos))
262 return 0;
7b204afd 263
c7066f70 264#ifdef CONFIG_IP_ROUTE_CLASSID
e1ef4bf2
TG
265 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
266 return 0;
267#endif
1da177e4 268
67b61f6c 269 if (frh->src_len && (rule4->src != nla_get_in_addr(tb[FRA_SRC])))
e1ef4bf2 270 return 0;
1da177e4 271
67b61f6c 272 if (frh->dst_len && (rule4->dst != nla_get_in_addr(tb[FRA_DST])))
e1ef4bf2 273 return 0;
1da177e4 274
e1ef4bf2 275 return 1;
1da177e4
LT
276}
277
e1ef4bf2 278static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
04af8cf6 279 struct fib_rule_hdr *frh)
e1ef4bf2
TG
280{
281 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
1da177e4 282
e1ef4bf2
TG
283 frh->dst_len = rule4->dst_len;
284 frh->src_len = rule4->src_len;
285 frh->tos = rule4->tos;
1da177e4 286
f3756b79 287 if ((rule4->dst_len &&
930345ea 288 nla_put_in_addr(skb, FRA_DST, rule4->dst)) ||
f3756b79 289 (rule4->src_len &&
930345ea 290 nla_put_in_addr(skb, FRA_SRC, rule4->src)))
f3756b79 291 goto nla_put_failure;
c7066f70 292#ifdef CONFIG_IP_ROUTE_CLASSID
f3756b79
DM
293 if (rule4->tclassid &&
294 nla_put_u32(skb, FRA_FLOW, rule4->tclassid))
295 goto nla_put_failure;
1da177e4 296#endif
e1ef4bf2 297 return 0;
1da177e4 298
e1ef4bf2
TG
299nla_put_failure:
300 return -ENOBUFS;
1da177e4
LT
301}
302
339bf98f
TG
303static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
304{
305 return nla_total_size(4) /* dst */
306 + nla_total_size(4) /* src */
307 + nla_total_size(4); /* flow */
308}
309
ae299fc0 310static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
73417f61 311{
bafa6d9d 312 rt_cache_flush(ops->fro_net);
73417f61
TG
313}
314
04a6f82c 315static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = {
25239cee 316 .family = AF_INET,
e1ef4bf2 317 .rule_size = sizeof(struct fib4_rule),
e1701c68 318 .addr_size = sizeof(u32),
e1ef4bf2 319 .action = fib4_rule_action,
7764a45a 320 .suppress = fib4_rule_suppress,
e1ef4bf2
TG
321 .match = fib4_rule_match,
322 .configure = fib4_rule_configure,
7a9bc9b8 323 .delete = fib4_rule_delete,
e1ef4bf2
TG
324 .compare = fib4_rule_compare,
325 .fill = fib4_rule_fill,
339bf98f 326 .nlmsg_payload = fib4_rule_nlmsg_payload,
73417f61 327 .flush_cache = fib4_rule_flush_cache,
e1ef4bf2
TG
328 .nlgroup = RTNLGRP_IPV4_RULE,
329 .policy = fib4_rule_policy,
e1ef4bf2
TG
330 .owner = THIS_MODULE,
331};
332
e4e4971c 333static int fib_default_rules_init(struct fib_rules_ops *ops)
1da177e4 334{
2994c638
DL
335 int err;
336
5adef180 337 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0);
2994c638
DL
338 if (err < 0)
339 return err;
e4e4971c 340 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
2994c638
DL
341 if (err < 0)
342 return err;
e4e4971c 343 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
2994c638
DL
344 if (err < 0)
345 return err;
346 return 0;
347}
1da177e4 348
7b1a74fd 349int __net_init fib4_rules_init(struct net *net)
2994c638 350{
dbb50165 351 int err;
e4e4971c
DL
352 struct fib_rules_ops *ops;
353
e9c5158a
EB
354 ops = fib_rules_register(&fib4_rules_ops_template, net);
355 if (IS_ERR(ops))
356 return PTR_ERR(ops);
dbb50165 357
e4e4971c 358 err = fib_default_rules_init(ops);
dbb50165
DL
359 if (err < 0)
360 goto fail;
e4e4971c 361 net->ipv4.rules_ops = ops;
f4530fa5 362 net->ipv4.fib_has_custom_rules = false;
dbb50165
DL
363 return 0;
364
365fail:
366 /* also cleans all rules already added */
9e3a5487 367 fib_rules_unregister(ops);
dbb50165 368 return err;
1da177e4 369}
7b1a74fd
DL
370
371void __net_exit fib4_rules_exit(struct net *net)
372{
9e3a5487 373 fib_rules_unregister(net->ipv4.rules_ops);
7b1a74fd 374}
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