Commit | Line | Data |
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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 | 36 | struct 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 |
50 | static 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 | ||
59 | bool 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 | } | |
69 | EXPORT_SYMBOL_GPL(fib4_rule_default); | |
70 | ||
1b2a4440 IS |
71 | int fib4_rules_dump(struct net *net, struct notifier_block *nb) |
72 | { | |
73 | return fib_rules_dump(net, nb, AF_INET); | |
74 | } | |
75 | ||
76 | unsigned int fib4_rules_seq_read(struct net *net) | |
77 | { | |
78 | return fib_rules_seq_read(net, AF_INET); | |
79 | } | |
80 | ||
0eeb075f AG |
81 | int __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 | 106 | EXPORT_SYMBOL_GPL(__fib_lookup); |
e1ef4bf2 | 107 | |
8ce11e6a AB |
108 | static 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 |
143 | static 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 | |
165 | suppress_route: | |
166 | if (!(arg->flags & FIB_LOOKUP_NOREF)) | |
167 | fib_info_put(result->fi); | |
168 | return true; | |
7764a45a | 169 | } |
e1ef4bf2 | 170 | |
e1ef4bf2 TG |
171 | static 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 | ||
e1ef4bf2 TG |
185 | return 1; |
186 | } | |
1da177e4 | 187 | |
8ad4942c | 188 | static struct fib_table *fib_empty_table(struct net *net) |
1da177e4 | 189 | { |
2dfe55b4 | 190 | u32 id; |
1da177e4 LT |
191 | |
192 | for (id = 1; id <= RT_TABLE_MAX; id++) | |
51456b29 | 193 | if (!fib_get_table(net, id)) |
8ad4942c | 194 | return fib_new_table(net, id); |
1da177e4 LT |
195 | return NULL; |
196 | } | |
197 | ||
ef7c79ed | 198 | static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = { |
1f6c9557 | 199 | FRA_GENERIC_POLICY, |
e1ef4bf2 TG |
200 | [FRA_FLOW] = { .type = NLA_U32 }, |
201 | }; | |
7b204afd | 202 | |
e1ef4bf2 | 203 | static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb, |
8b3521ee | 204 | struct fib_rule_hdr *frh, |
e1ef4bf2 | 205 | struct nlattr **tb) |
1da177e4 | 206 | { |
3b1e0a65 | 207 | struct net *net = sock_net(skb->sk); |
e1ef4bf2 TG |
208 | int err = -EINVAL; |
209 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
1da177e4 | 210 | |
e1701c68 | 211 | if (frh->tos & ~IPTOS_TOS_MASK) |
e1ef4bf2 | 212 | goto errout; |
7b204afd | 213 | |
0ddcf43d AD |
214 | /* split local/main if they are not already split */ |
215 | err = fib_unmerge(net); | |
216 | if (err) | |
217 | goto errout; | |
218 | ||
96c63fa7 | 219 | if (rule->table == RT_TABLE_UNSPEC && !rule->l3mdev) { |
e1ef4bf2 TG |
220 | if (rule->action == FR_ACT_TO_TBL) { |
221 | struct fib_table *table; | |
1da177e4 | 222 | |
e4e4971c | 223 | table = fib_empty_table(net); |
51456b29 | 224 | if (!table) { |
e1ef4bf2 TG |
225 | err = -ENOBUFS; |
226 | goto errout; | |
227 | } | |
1da177e4 | 228 | |
e1ef4bf2 | 229 | rule->table = table->tb_id; |
1da177e4 LT |
230 | } |
231 | } | |
232 | ||
e1701c68 | 233 | if (frh->src_len) |
67b61f6c | 234 | rule4->src = nla_get_in_addr(tb[FRA_SRC]); |
7b204afd | 235 | |
e1701c68 | 236 | if (frh->dst_len) |
67b61f6c | 237 | rule4->dst = nla_get_in_addr(tb[FRA_DST]); |
7b204afd | 238 | |
c7066f70 | 239 | #ifdef CONFIG_IP_ROUTE_CLASSID |
7a9bc9b8 | 240 | if (tb[FRA_FLOW]) { |
e1ef4bf2 | 241 | rule4->tclassid = nla_get_u32(tb[FRA_FLOW]); |
7a9bc9b8 | 242 | if (rule4->tclassid) |
f4530fa5 | 243 | net->ipv4.fib_num_tclassid_users++; |
7a9bc9b8 | 244 | } |
1da177e4 LT |
245 | #endif |
246 | ||
e1ef4bf2 TG |
247 | rule4->src_len = frh->src_len; |
248 | rule4->srcmask = inet_make_mask(rule4->src_len); | |
249 | rule4->dst_len = frh->dst_len; | |
250 | rule4->dstmask = inet_make_mask(rule4->dst_len); | |
251 | rule4->tos = frh->tos; | |
7b204afd | 252 | |
f4530fa5 | 253 | net->ipv4.fib_has_custom_rules = true; |
104616e7 | 254 | |
e1ef4bf2 TG |
255 | err = 0; |
256 | errout: | |
257 | return err; | |
1da177e4 LT |
258 | } |
259 | ||
0ddcf43d | 260 | static int fib4_rule_delete(struct fib_rule *rule) |
7a9bc9b8 | 261 | { |
f4530fa5 | 262 | struct net *net = rule->fr_net; |
0ddcf43d | 263 | int err; |
7a9bc9b8 | 264 | |
0ddcf43d AD |
265 | /* split local/main if they are not already split */ |
266 | err = fib_unmerge(net); | |
267 | if (err) | |
268 | goto errout; | |
269 | ||
270 | #ifdef CONFIG_IP_ROUTE_CLASSID | |
271 | if (((struct fib4_rule *)rule)->tclassid) | |
f4530fa5 | 272 | net->ipv4.fib_num_tclassid_users--; |
7a9bc9b8 | 273 | #endif |
f4530fa5 | 274 | net->ipv4.fib_has_custom_rules = true; |
0ddcf43d AD |
275 | errout: |
276 | return err; | |
7a9bc9b8 DM |
277 | } |
278 | ||
e1ef4bf2 TG |
279 | static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, |
280 | struct nlattr **tb) | |
1da177e4 | 281 | { |
e1ef4bf2 | 282 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; |
1da177e4 | 283 | |
e1ef4bf2 TG |
284 | if (frh->src_len && (rule4->src_len != frh->src_len)) |
285 | return 0; | |
1da177e4 | 286 | |
e1ef4bf2 TG |
287 | if (frh->dst_len && (rule4->dst_len != frh->dst_len)) |
288 | return 0; | |
7b204afd | 289 | |
e1ef4bf2 TG |
290 | if (frh->tos && (rule4->tos != frh->tos)) |
291 | return 0; | |
7b204afd | 292 | |
c7066f70 | 293 | #ifdef CONFIG_IP_ROUTE_CLASSID |
e1ef4bf2 TG |
294 | if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW]))) |
295 | return 0; | |
296 | #endif | |
1da177e4 | 297 | |
67b61f6c | 298 | if (frh->src_len && (rule4->src != nla_get_in_addr(tb[FRA_SRC]))) |
e1ef4bf2 | 299 | return 0; |
1da177e4 | 300 | |
67b61f6c | 301 | if (frh->dst_len && (rule4->dst != nla_get_in_addr(tb[FRA_DST]))) |
e1ef4bf2 | 302 | return 0; |
1da177e4 | 303 | |
e1ef4bf2 | 304 | return 1; |
1da177e4 LT |
305 | } |
306 | ||
e1ef4bf2 | 307 | static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb, |
04af8cf6 | 308 | struct fib_rule_hdr *frh) |
e1ef4bf2 TG |
309 | { |
310 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
1da177e4 | 311 | |
e1ef4bf2 TG |
312 | frh->dst_len = rule4->dst_len; |
313 | frh->src_len = rule4->src_len; | |
314 | frh->tos = rule4->tos; | |
1da177e4 | 315 | |
f3756b79 | 316 | if ((rule4->dst_len && |
930345ea | 317 | nla_put_in_addr(skb, FRA_DST, rule4->dst)) || |
f3756b79 | 318 | (rule4->src_len && |
930345ea | 319 | nla_put_in_addr(skb, FRA_SRC, rule4->src))) |
f3756b79 | 320 | goto nla_put_failure; |
c7066f70 | 321 | #ifdef CONFIG_IP_ROUTE_CLASSID |
f3756b79 DM |
322 | if (rule4->tclassid && |
323 | nla_put_u32(skb, FRA_FLOW, rule4->tclassid)) | |
324 | goto nla_put_failure; | |
1da177e4 | 325 | #endif |
e1ef4bf2 | 326 | return 0; |
1da177e4 | 327 | |
e1ef4bf2 TG |
328 | nla_put_failure: |
329 | return -ENOBUFS; | |
1da177e4 LT |
330 | } |
331 | ||
339bf98f TG |
332 | static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule) |
333 | { | |
334 | return nla_total_size(4) /* dst */ | |
335 | + nla_total_size(4) /* src */ | |
336 | + nla_total_size(4); /* flow */ | |
337 | } | |
338 | ||
ae299fc0 | 339 | static void fib4_rule_flush_cache(struct fib_rules_ops *ops) |
73417f61 | 340 | { |
bafa6d9d | 341 | rt_cache_flush(ops->fro_net); |
73417f61 TG |
342 | } |
343 | ||
04a6f82c | 344 | static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = { |
25239cee | 345 | .family = AF_INET, |
e1ef4bf2 | 346 | .rule_size = sizeof(struct fib4_rule), |
e1701c68 | 347 | .addr_size = sizeof(u32), |
e1ef4bf2 | 348 | .action = fib4_rule_action, |
7764a45a | 349 | .suppress = fib4_rule_suppress, |
e1ef4bf2 TG |
350 | .match = fib4_rule_match, |
351 | .configure = fib4_rule_configure, | |
7a9bc9b8 | 352 | .delete = fib4_rule_delete, |
e1ef4bf2 TG |
353 | .compare = fib4_rule_compare, |
354 | .fill = fib4_rule_fill, | |
339bf98f | 355 | .nlmsg_payload = fib4_rule_nlmsg_payload, |
73417f61 | 356 | .flush_cache = fib4_rule_flush_cache, |
e1ef4bf2 TG |
357 | .nlgroup = RTNLGRP_IPV4_RULE, |
358 | .policy = fib4_rule_policy, | |
e1ef4bf2 TG |
359 | .owner = THIS_MODULE, |
360 | }; | |
361 | ||
e4e4971c | 362 | static int fib_default_rules_init(struct fib_rules_ops *ops) |
1da177e4 | 363 | { |
2994c638 DL |
364 | int err; |
365 | ||
5adef180 | 366 | err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0); |
2994c638 DL |
367 | if (err < 0) |
368 | return err; | |
e4e4971c | 369 | err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0); |
2994c638 DL |
370 | if (err < 0) |
371 | return err; | |
e4e4971c | 372 | err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0); |
2994c638 DL |
373 | if (err < 0) |
374 | return err; | |
375 | return 0; | |
376 | } | |
1da177e4 | 377 | |
7b1a74fd | 378 | int __net_init fib4_rules_init(struct net *net) |
2994c638 | 379 | { |
dbb50165 | 380 | int err; |
e4e4971c DL |
381 | struct fib_rules_ops *ops; |
382 | ||
e9c5158a EB |
383 | ops = fib_rules_register(&fib4_rules_ops_template, net); |
384 | if (IS_ERR(ops)) | |
385 | return PTR_ERR(ops); | |
dbb50165 | 386 | |
e4e4971c | 387 | err = fib_default_rules_init(ops); |
dbb50165 DL |
388 | if (err < 0) |
389 | goto fail; | |
e4e4971c | 390 | net->ipv4.rules_ops = ops; |
f4530fa5 | 391 | net->ipv4.fib_has_custom_rules = false; |
dbb50165 DL |
392 | return 0; |
393 | ||
394 | fail: | |
395 | /* also cleans all rules already added */ | |
9e3a5487 | 396 | fib_rules_unregister(ops); |
dbb50165 | 397 | return err; |
1da177e4 | 398 | } |
7b1a74fd DL |
399 | |
400 | void __net_exit fib4_rules_exit(struct net *net) | |
401 | { | |
9e3a5487 | 402 | fib_rules_unregister(net->ipv4.rules_ops); |
7b1a74fd | 403 | } |