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 | |
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 | 72 | EXPORT_SYMBOL_GPL(__fib_lookup); |
e1ef4bf2 | 73 | |
8ce11e6a AB |
74 | static 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 |
107 | static 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 | |
129 | suppress_route: | |
130 | if (!(arg->flags & FIB_LOOKUP_NOREF)) | |
131 | fib_info_put(result->fi); | |
132 | return true; | |
7764a45a | 133 | } |
e1ef4bf2 | 134 | |
e1ef4bf2 TG |
135 | static 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 | 152 | static 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 | 162 | static 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 | 167 | static 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; |
221 | errout: | |
222 | return err; | |
1da177e4 LT |
223 | } |
224 | ||
0ddcf43d | 225 | static 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 |
241 | errout: |
242 | return err; | |
7a9bc9b8 DM |
243 | } |
244 | ||
e1ef4bf2 TG |
245 | static 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 | 273 | static 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 |
294 | nla_put_failure: |
295 | return -ENOBUFS; | |
1da177e4 LT |
296 | } |
297 | ||
339bf98f TG |
298 | static 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 | 305 | static 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 | 310 | static 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 | 328 | static 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 | 344 | int __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 | ||
360 | fail: | |
361 | /* also cleans all rules already added */ | |
9e3a5487 | 362 | fib_rules_unregister(ops); |
dbb50165 | 363 | return err; |
1da177e4 | 364 | } |
7b1a74fd DL |
365 | |
366 | void __net_exit fib4_rules_exit(struct net *net) | |
367 | { | |
9e3a5487 | 368 | fib_rules_unregister(net->ipv4.rules_ops); |
7b1a74fd | 369 | } |