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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 | ||
0eeb075f AG |
50 | int __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 | 75 | EXPORT_SYMBOL_GPL(__fib_lookup); |
e1ef4bf2 | 76 | |
8ce11e6a AB |
77 | static 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 |
112 | static 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 | |
134 | suppress_route: | |
135 | if (!(arg->flags & FIB_LOOKUP_NOREF)) | |
136 | fib_info_put(result->fi); | |
137 | return true; | |
7764a45a | 138 | } |
e1ef4bf2 | 139 | |
e1ef4bf2 TG |
140 | static 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 | 157 | static 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 | ||
b90eb754 JP |
167 | static int call_fib_rule_notifiers(struct net *net, |
168 | enum fib_event_type event_type) | |
169 | { | |
170 | struct fib_notifier_info info; | |
171 | ||
172 | return call_fib_notifiers(net, event_type, &info); | |
173 | } | |
174 | ||
ef7c79ed | 175 | static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = { |
1f6c9557 | 176 | FRA_GENERIC_POLICY, |
e1ef4bf2 TG |
177 | [FRA_FLOW] = { .type = NLA_U32 }, |
178 | }; | |
7b204afd | 179 | |
e1ef4bf2 | 180 | static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb, |
8b3521ee | 181 | struct fib_rule_hdr *frh, |
e1ef4bf2 | 182 | struct nlattr **tb) |
1da177e4 | 183 | { |
3b1e0a65 | 184 | struct net *net = sock_net(skb->sk); |
e1ef4bf2 TG |
185 | int err = -EINVAL; |
186 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
1da177e4 | 187 | |
e1701c68 | 188 | if (frh->tos & ~IPTOS_TOS_MASK) |
e1ef4bf2 | 189 | goto errout; |
7b204afd | 190 | |
0ddcf43d AD |
191 | /* split local/main if they are not already split */ |
192 | err = fib_unmerge(net); | |
193 | if (err) | |
194 | goto errout; | |
195 | ||
96c63fa7 | 196 | if (rule->table == RT_TABLE_UNSPEC && !rule->l3mdev) { |
e1ef4bf2 TG |
197 | if (rule->action == FR_ACT_TO_TBL) { |
198 | struct fib_table *table; | |
1da177e4 | 199 | |
e4e4971c | 200 | table = fib_empty_table(net); |
51456b29 | 201 | if (!table) { |
e1ef4bf2 TG |
202 | err = -ENOBUFS; |
203 | goto errout; | |
204 | } | |
1da177e4 | 205 | |
e1ef4bf2 | 206 | rule->table = table->tb_id; |
1da177e4 LT |
207 | } |
208 | } | |
209 | ||
e1701c68 | 210 | if (frh->src_len) |
67b61f6c | 211 | rule4->src = nla_get_in_addr(tb[FRA_SRC]); |
7b204afd | 212 | |
e1701c68 | 213 | if (frh->dst_len) |
67b61f6c | 214 | rule4->dst = nla_get_in_addr(tb[FRA_DST]); |
7b204afd | 215 | |
c7066f70 | 216 | #ifdef CONFIG_IP_ROUTE_CLASSID |
7a9bc9b8 | 217 | if (tb[FRA_FLOW]) { |
e1ef4bf2 | 218 | rule4->tclassid = nla_get_u32(tb[FRA_FLOW]); |
7a9bc9b8 | 219 | if (rule4->tclassid) |
f4530fa5 | 220 | net->ipv4.fib_num_tclassid_users++; |
7a9bc9b8 | 221 | } |
1da177e4 LT |
222 | #endif |
223 | ||
e1ef4bf2 TG |
224 | rule4->src_len = frh->src_len; |
225 | rule4->srcmask = inet_make_mask(rule4->src_len); | |
226 | rule4->dst_len = frh->dst_len; | |
227 | rule4->dstmask = inet_make_mask(rule4->dst_len); | |
228 | rule4->tos = frh->tos; | |
7b204afd | 229 | |
f4530fa5 | 230 | net->ipv4.fib_has_custom_rules = true; |
b90eb754 | 231 | call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD); |
104616e7 | 232 | |
e1ef4bf2 TG |
233 | err = 0; |
234 | errout: | |
235 | return err; | |
1da177e4 LT |
236 | } |
237 | ||
0ddcf43d | 238 | static int fib4_rule_delete(struct fib_rule *rule) |
7a9bc9b8 | 239 | { |
f4530fa5 | 240 | struct net *net = rule->fr_net; |
0ddcf43d | 241 | int err; |
7a9bc9b8 | 242 | |
0ddcf43d AD |
243 | /* split local/main if they are not already split */ |
244 | err = fib_unmerge(net); | |
245 | if (err) | |
246 | goto errout; | |
247 | ||
248 | #ifdef CONFIG_IP_ROUTE_CLASSID | |
249 | if (((struct fib4_rule *)rule)->tclassid) | |
f4530fa5 | 250 | net->ipv4.fib_num_tclassid_users--; |
7a9bc9b8 | 251 | #endif |
f4530fa5 | 252 | net->ipv4.fib_has_custom_rules = true; |
b90eb754 | 253 | call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL); |
0ddcf43d AD |
254 | errout: |
255 | return err; | |
7a9bc9b8 DM |
256 | } |
257 | ||
e1ef4bf2 TG |
258 | static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, |
259 | struct nlattr **tb) | |
1da177e4 | 260 | { |
e1ef4bf2 | 261 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; |
1da177e4 | 262 | |
e1ef4bf2 TG |
263 | if (frh->src_len && (rule4->src_len != frh->src_len)) |
264 | return 0; | |
1da177e4 | 265 | |
e1ef4bf2 TG |
266 | if (frh->dst_len && (rule4->dst_len != frh->dst_len)) |
267 | return 0; | |
7b204afd | 268 | |
e1ef4bf2 TG |
269 | if (frh->tos && (rule4->tos != frh->tos)) |
270 | return 0; | |
7b204afd | 271 | |
c7066f70 | 272 | #ifdef CONFIG_IP_ROUTE_CLASSID |
e1ef4bf2 TG |
273 | if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW]))) |
274 | return 0; | |
275 | #endif | |
1da177e4 | 276 | |
67b61f6c | 277 | if (frh->src_len && (rule4->src != nla_get_in_addr(tb[FRA_SRC]))) |
e1ef4bf2 | 278 | return 0; |
1da177e4 | 279 | |
67b61f6c | 280 | if (frh->dst_len && (rule4->dst != nla_get_in_addr(tb[FRA_DST]))) |
e1ef4bf2 | 281 | return 0; |
1da177e4 | 282 | |
e1ef4bf2 | 283 | return 1; |
1da177e4 LT |
284 | } |
285 | ||
e1ef4bf2 | 286 | static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb, |
04af8cf6 | 287 | struct fib_rule_hdr *frh) |
e1ef4bf2 TG |
288 | { |
289 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
1da177e4 | 290 | |
e1ef4bf2 TG |
291 | frh->dst_len = rule4->dst_len; |
292 | frh->src_len = rule4->src_len; | |
293 | frh->tos = rule4->tos; | |
1da177e4 | 294 | |
f3756b79 | 295 | if ((rule4->dst_len && |
930345ea | 296 | nla_put_in_addr(skb, FRA_DST, rule4->dst)) || |
f3756b79 | 297 | (rule4->src_len && |
930345ea | 298 | nla_put_in_addr(skb, FRA_SRC, rule4->src))) |
f3756b79 | 299 | goto nla_put_failure; |
c7066f70 | 300 | #ifdef CONFIG_IP_ROUTE_CLASSID |
f3756b79 DM |
301 | if (rule4->tclassid && |
302 | nla_put_u32(skb, FRA_FLOW, rule4->tclassid)) | |
303 | goto nla_put_failure; | |
1da177e4 | 304 | #endif |
e1ef4bf2 | 305 | return 0; |
1da177e4 | 306 | |
e1ef4bf2 TG |
307 | nla_put_failure: |
308 | return -ENOBUFS; | |
1da177e4 LT |
309 | } |
310 | ||
339bf98f TG |
311 | static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule) |
312 | { | |
313 | return nla_total_size(4) /* dst */ | |
314 | + nla_total_size(4) /* src */ | |
315 | + nla_total_size(4); /* flow */ | |
316 | } | |
317 | ||
ae299fc0 | 318 | static void fib4_rule_flush_cache(struct fib_rules_ops *ops) |
73417f61 | 319 | { |
bafa6d9d | 320 | rt_cache_flush(ops->fro_net); |
73417f61 TG |
321 | } |
322 | ||
04a6f82c | 323 | static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = { |
25239cee | 324 | .family = AF_INET, |
e1ef4bf2 | 325 | .rule_size = sizeof(struct fib4_rule), |
e1701c68 | 326 | .addr_size = sizeof(u32), |
e1ef4bf2 | 327 | .action = fib4_rule_action, |
7764a45a | 328 | .suppress = fib4_rule_suppress, |
e1ef4bf2 TG |
329 | .match = fib4_rule_match, |
330 | .configure = fib4_rule_configure, | |
7a9bc9b8 | 331 | .delete = fib4_rule_delete, |
e1ef4bf2 TG |
332 | .compare = fib4_rule_compare, |
333 | .fill = fib4_rule_fill, | |
339bf98f | 334 | .nlmsg_payload = fib4_rule_nlmsg_payload, |
73417f61 | 335 | .flush_cache = fib4_rule_flush_cache, |
e1ef4bf2 TG |
336 | .nlgroup = RTNLGRP_IPV4_RULE, |
337 | .policy = fib4_rule_policy, | |
e1ef4bf2 TG |
338 | .owner = THIS_MODULE, |
339 | }; | |
340 | ||
e4e4971c | 341 | static int fib_default_rules_init(struct fib_rules_ops *ops) |
1da177e4 | 342 | { |
2994c638 DL |
343 | int err; |
344 | ||
5adef180 | 345 | err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0); |
2994c638 DL |
346 | if (err < 0) |
347 | return err; | |
e4e4971c | 348 | err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0); |
2994c638 DL |
349 | if (err < 0) |
350 | return err; | |
e4e4971c | 351 | err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0); |
2994c638 DL |
352 | if (err < 0) |
353 | return err; | |
354 | return 0; | |
355 | } | |
1da177e4 | 356 | |
7b1a74fd | 357 | int __net_init fib4_rules_init(struct net *net) |
2994c638 | 358 | { |
dbb50165 | 359 | int err; |
e4e4971c DL |
360 | struct fib_rules_ops *ops; |
361 | ||
e9c5158a EB |
362 | ops = fib_rules_register(&fib4_rules_ops_template, net); |
363 | if (IS_ERR(ops)) | |
364 | return PTR_ERR(ops); | |
dbb50165 | 365 | |
e4e4971c | 366 | err = fib_default_rules_init(ops); |
dbb50165 DL |
367 | if (err < 0) |
368 | goto fail; | |
e4e4971c | 369 | net->ipv4.rules_ops = ops; |
f4530fa5 | 370 | net->ipv4.fib_has_custom_rules = false; |
dbb50165 DL |
371 | return 0; |
372 | ||
373 | fail: | |
374 | /* also cleans all rules already added */ | |
9e3a5487 | 375 | fib_rules_unregister(ops); |
dbb50165 | 376 | return err; |
1da177e4 | 377 | } |
7b1a74fd DL |
378 | |
379 | void __net_exit fib4_rules_exit(struct net *net) | |
380 | { | |
9e3a5487 | 381 | fib_rules_unregister(net->ipv4.rules_ops); |
7b1a74fd | 382 | } |