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