Merge tag 'pstore-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees...
[linux-2.6-block.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
3c71006d
IS
50static bool fib4_rule_matchall(const struct fib_rule *rule)
51{
52 struct fib4_rule *r = container_of(rule, struct fib4_rule, common);
53
54 if (r->dst_len || r->src_len || r->tos)
55 return false;
56 return fib_rule_matchall(rule);
57}
58
59bool fib4_rule_default(const struct fib_rule *rule)
60{
61 if (!fib4_rule_matchall(rule) || rule->action != FR_ACT_TO_TBL ||
62 rule->l3mdev)
63 return false;
64 if (rule->table != RT_TABLE_LOCAL && rule->table != RT_TABLE_MAIN &&
65 rule->table != RT_TABLE_DEFAULT)
66 return false;
67 return true;
68}
69EXPORT_SYMBOL_GPL(fib4_rule_default);
70
1b2a4440
IS
71int fib4_rules_dump(struct net *net, struct notifier_block *nb)
72{
73 return fib_rules_dump(net, nb, AF_INET);
74}
75
76unsigned int fib4_rules_seq_read(struct net *net)
77{
78 return fib_rules_seq_read(net, AF_INET);
79}
80
0eeb075f
AG
81int __fib_lookup(struct net *net, struct flowi4 *flp,
82 struct fib_result *res, unsigned int flags)
e1ef4bf2
TG
83{
84 struct fib_lookup_arg arg = {
85 .result = res,
0eeb075f 86 .flags = flags,
e1ef4bf2
TG
87 };
88 int err;
1da177e4 89
9ee0034b
DA
90 /* update flow if oif or iif point to device enslaved to l3mdev */
91 l3mdev_update_flow(net, flowi4_to_flowi(flp));
92
22bd5b9b 93 err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg);
85b91b03
DM
94#ifdef CONFIG_IP_ROUTE_CLASSID
95 if (arg.rule)
96 res->tclassid = ((struct fib4_rule *)arg.rule)->tclassid;
97 else
98 res->tclassid = 0;
99#endif
49dd18ba
PM
100
101 if (err == -ESRCH)
102 err = -ENETUNREACH;
103
e1ef4bf2
TG
104 return err;
105}
f4530fa5 106EXPORT_SYMBOL_GPL(__fib_lookup);
e1ef4bf2 107
8ce11e6a
AB
108static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
109 int flags, struct fib_lookup_arg *arg)
1da177e4 110{
e1ef4bf2
TG
111 int err = -EAGAIN;
112 struct fib_table *tbl;
96c63fa7 113 u32 tb_id;
e1ef4bf2
TG
114
115 switch (rule->action) {
116 case FR_ACT_TO_TBL:
117 break;
118
119 case FR_ACT_UNREACHABLE:
345e9b54 120 return -ENETUNREACH;
e1ef4bf2
TG
121
122 case FR_ACT_PROHIBIT:
345e9b54 123 return -EACCES;
e1ef4bf2
TG
124
125 case FR_ACT_BLACKHOLE:
126 default:
345e9b54 127 return -EINVAL;
1da177e4 128 }
e1ef4bf2 129
345e9b54
AD
130 rcu_read_lock();
131
96c63fa7
DA
132 tb_id = fib_rule_get_table(rule, arg);
133 tbl = fib_get_table(rule->fr_net, tb_id);
345e9b54
AD
134 if (tbl)
135 err = fib_table_lookup(tbl, &flp->u.ip4,
136 (struct fib_result *)arg->result,
137 arg->flags);
e1ef4bf2 138
345e9b54 139 rcu_read_unlock();
1da177e4
LT
140 return err;
141}
142
7764a45a
ST
143static bool fib4_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)
144{
6ef94cfa 145 struct fib_result *result = (struct fib_result *) arg->result;
673498b8
ST
146 struct net_device *dev = NULL;
147
148 if (result->fi)
149 dev = result->fi->fib_dev;
6ef94cfa 150
7764a45a
ST
151 /* do not accept result if the route does
152 * not meet the required prefix length
153 */
73f5698e 154 if (result->prefixlen <= rule->suppress_prefixlen)
6ef94cfa
ST
155 goto suppress_route;
156
157 /* do not accept result if the route uses a device
158 * belonging to a forbidden interface group
159 */
160 if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
161 goto suppress_route;
162
7764a45a 163 return false;
6ef94cfa
ST
164
165suppress_route:
166 if (!(arg->flags & FIB_LOOKUP_NOREF))
167 fib_info_put(result->fi);
168 return true;
7764a45a 169}
e1ef4bf2 170
e1ef4bf2
TG
171static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
172{
173 struct fib4_rule *r = (struct fib4_rule *) rule;
9ade2286
DM
174 struct flowi4 *fl4 = &fl->u.ip4;
175 __be32 daddr = fl4->daddr;
176 __be32 saddr = fl4->saddr;
e1ef4bf2
TG
177
178 if (((saddr ^ r->src) & r->srcmask) ||
179 ((daddr ^ r->dst) & r->dstmask))
180 return 0;
181
9ade2286 182 if (r->tos && (r->tos != fl4->flowi4_tos))
e1ef4bf2
TG
183 return 0;
184
4a2d73a4
RP
185 if (rule->ip_proto && (rule->ip_proto != fl4->flowi4_proto))
186 return 0;
187
188 if (fib_rule_port_range_set(&rule->sport_range) &&
189 !fib_rule_port_inrange(&rule->sport_range, fl4->fl4_sport))
190 return 0;
191
192 if (fib_rule_port_range_set(&rule->dport_range) &&
193 !fib_rule_port_inrange(&rule->dport_range, fl4->fl4_dport))
194 return 0;
195
e1ef4bf2
TG
196 return 1;
197}
1da177e4 198
8ad4942c 199static struct fib_table *fib_empty_table(struct net *net)
1da177e4 200{
2dfe55b4 201 u32 id;
1da177e4
LT
202
203 for (id = 1; id <= RT_TABLE_MAX; id++)
51456b29 204 if (!fib_get_table(net, id))
8ad4942c 205 return fib_new_table(net, id);
1da177e4
LT
206 return NULL;
207}
208
ef7c79ed 209static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
1f6c9557 210 FRA_GENERIC_POLICY,
e1ef4bf2
TG
211 [FRA_FLOW] = { .type = NLA_U32 },
212};
7b204afd 213
e1ef4bf2 214static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
8b3521ee 215 struct fib_rule_hdr *frh,
b16fb418
RP
216 struct nlattr **tb,
217 struct netlink_ext_ack *extack)
1da177e4 218{
3b1e0a65 219 struct net *net = sock_net(skb->sk);
e1ef4bf2
TG
220 int err = -EINVAL;
221 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
1da177e4 222
b16fb418
RP
223 if (frh->tos & ~IPTOS_TOS_MASK) {
224 NL_SET_ERR_MSG(extack, "Invalid tos");
e1ef4bf2 225 goto errout;
b16fb418 226 }
7b204afd 227
0ddcf43d
AD
228 /* split local/main if they are not already split */
229 err = fib_unmerge(net);
230 if (err)
231 goto errout;
232
96c63fa7 233 if (rule->table == RT_TABLE_UNSPEC && !rule->l3mdev) {
e1ef4bf2
TG
234 if (rule->action == FR_ACT_TO_TBL) {
235 struct fib_table *table;
1da177e4 236
e4e4971c 237 table = fib_empty_table(net);
51456b29 238 if (!table) {
e1ef4bf2
TG
239 err = -ENOBUFS;
240 goto errout;
241 }
1da177e4 242
e1ef4bf2 243 rule->table = table->tb_id;
1da177e4
LT
244 }
245 }
246
e1701c68 247 if (frh->src_len)
67b61f6c 248 rule4->src = nla_get_in_addr(tb[FRA_SRC]);
7b204afd 249
e1701c68 250 if (frh->dst_len)
67b61f6c 251 rule4->dst = nla_get_in_addr(tb[FRA_DST]);
7b204afd 252
c7066f70 253#ifdef CONFIG_IP_ROUTE_CLASSID
7a9bc9b8 254 if (tb[FRA_FLOW]) {
e1ef4bf2 255 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
7a9bc9b8 256 if (rule4->tclassid)
f4530fa5 257 net->ipv4.fib_num_tclassid_users++;
7a9bc9b8 258 }
1da177e4
LT
259#endif
260
e37b1e97
RP
261 if (fib_rule_requires_fldissect(rule))
262 net->ipv4.fib_rules_require_fldissect++;
263
e1ef4bf2
TG
264 rule4->src_len = frh->src_len;
265 rule4->srcmask = inet_make_mask(rule4->src_len);
266 rule4->dst_len = frh->dst_len;
267 rule4->dstmask = inet_make_mask(rule4->dst_len);
268 rule4->tos = frh->tos;
7b204afd 269
f4530fa5 270 net->ipv4.fib_has_custom_rules = true;
104616e7 271
e1ef4bf2
TG
272 err = 0;
273errout:
274 return err;
1da177e4
LT
275}
276
0ddcf43d 277static int fib4_rule_delete(struct fib_rule *rule)
7a9bc9b8 278{
f4530fa5 279 struct net *net = rule->fr_net;
0ddcf43d 280 int err;
7a9bc9b8 281
0ddcf43d
AD
282 /* split local/main if they are not already split */
283 err = fib_unmerge(net);
284 if (err)
285 goto errout;
286
287#ifdef CONFIG_IP_ROUTE_CLASSID
288 if (((struct fib4_rule *)rule)->tclassid)
f4530fa5 289 net->ipv4.fib_num_tclassid_users--;
7a9bc9b8 290#endif
f4530fa5 291 net->ipv4.fib_has_custom_rules = true;
e37b1e97
RP
292
293 if (net->ipv4.fib_rules_require_fldissect &&
294 fib_rule_requires_fldissect(rule))
295 net->ipv4.fib_rules_require_fldissect--;
0ddcf43d
AD
296errout:
297 return err;
7a9bc9b8
DM
298}
299
e1ef4bf2
TG
300static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
301 struct nlattr **tb)
1da177e4 302{
e1ef4bf2 303 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
1da177e4 304
e1ef4bf2
TG
305 if (frh->src_len && (rule4->src_len != frh->src_len))
306 return 0;
1da177e4 307
e1ef4bf2
TG
308 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
309 return 0;
7b204afd 310
e1ef4bf2
TG
311 if (frh->tos && (rule4->tos != frh->tos))
312 return 0;
7b204afd 313
c7066f70 314#ifdef CONFIG_IP_ROUTE_CLASSID
e1ef4bf2
TG
315 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
316 return 0;
317#endif
1da177e4 318
67b61f6c 319 if (frh->src_len && (rule4->src != nla_get_in_addr(tb[FRA_SRC])))
e1ef4bf2 320 return 0;
1da177e4 321
67b61f6c 322 if (frh->dst_len && (rule4->dst != nla_get_in_addr(tb[FRA_DST])))
e1ef4bf2 323 return 0;
1da177e4 324
e1ef4bf2 325 return 1;
1da177e4
LT
326}
327
e1ef4bf2 328static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
04af8cf6 329 struct fib_rule_hdr *frh)
e1ef4bf2
TG
330{
331 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
1da177e4 332
e1ef4bf2
TG
333 frh->dst_len = rule4->dst_len;
334 frh->src_len = rule4->src_len;
335 frh->tos = rule4->tos;
1da177e4 336
f3756b79 337 if ((rule4->dst_len &&
930345ea 338 nla_put_in_addr(skb, FRA_DST, rule4->dst)) ||
f3756b79 339 (rule4->src_len &&
930345ea 340 nla_put_in_addr(skb, FRA_SRC, rule4->src)))
f3756b79 341 goto nla_put_failure;
c7066f70 342#ifdef CONFIG_IP_ROUTE_CLASSID
f3756b79
DM
343 if (rule4->tclassid &&
344 nla_put_u32(skb, FRA_FLOW, rule4->tclassid))
345 goto nla_put_failure;
1da177e4 346#endif
e1ef4bf2 347 return 0;
1da177e4 348
e1ef4bf2
TG
349nla_put_failure:
350 return -ENOBUFS;
1da177e4
LT
351}
352
339bf98f
TG
353static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
354{
355 return nla_total_size(4) /* dst */
356 + nla_total_size(4) /* src */
357 + nla_total_size(4); /* flow */
358}
359
ae299fc0 360static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
73417f61 361{
bafa6d9d 362 rt_cache_flush(ops->fro_net);
73417f61
TG
363}
364
04a6f82c 365static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = {
25239cee 366 .family = AF_INET,
e1ef4bf2 367 .rule_size = sizeof(struct fib4_rule),
e1701c68 368 .addr_size = sizeof(u32),
e1ef4bf2 369 .action = fib4_rule_action,
7764a45a 370 .suppress = fib4_rule_suppress,
e1ef4bf2
TG
371 .match = fib4_rule_match,
372 .configure = fib4_rule_configure,
7a9bc9b8 373 .delete = fib4_rule_delete,
e1ef4bf2
TG
374 .compare = fib4_rule_compare,
375 .fill = fib4_rule_fill,
339bf98f 376 .nlmsg_payload = fib4_rule_nlmsg_payload,
73417f61 377 .flush_cache = fib4_rule_flush_cache,
e1ef4bf2
TG
378 .nlgroup = RTNLGRP_IPV4_RULE,
379 .policy = fib4_rule_policy,
e1ef4bf2
TG
380 .owner = THIS_MODULE,
381};
382
e4e4971c 383static int fib_default_rules_init(struct fib_rules_ops *ops)
1da177e4 384{
2994c638
DL
385 int err;
386
5adef180 387 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0);
2994c638
DL
388 if (err < 0)
389 return err;
e4e4971c 390 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
2994c638
DL
391 if (err < 0)
392 return err;
e4e4971c 393 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
2994c638
DL
394 if (err < 0)
395 return err;
396 return 0;
397}
1da177e4 398
7b1a74fd 399int __net_init fib4_rules_init(struct net *net)
2994c638 400{
dbb50165 401 int err;
e4e4971c
DL
402 struct fib_rules_ops *ops;
403
e9c5158a
EB
404 ops = fib_rules_register(&fib4_rules_ops_template, net);
405 if (IS_ERR(ops))
406 return PTR_ERR(ops);
dbb50165 407
e4e4971c 408 err = fib_default_rules_init(ops);
dbb50165
DL
409 if (err < 0)
410 goto fail;
e4e4971c 411 net->ipv4.rules_ops = ops;
f4530fa5 412 net->ipv4.fib_has_custom_rules = false;
e37b1e97 413 net->ipv4.fib_rules_require_fldissect = 0;
dbb50165
DL
414 return 0;
415
416fail:
417 /* also cleans all rules already added */
9e3a5487 418 fib_rules_unregister(ops);
dbb50165 419 return err;
1da177e4 420}
7b1a74fd
DL
421
422void __net_exit fib4_rules_exit(struct net *net)
423{
9e3a5487 424 fib_rules_unregister(net->ipv4.rules_ops);
7b1a74fd 425}