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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 | ||
f4530fa5 | 50 | int __fib_lookup(struct net *net, struct flowi4 *flp, struct fib_result *res) |
e1ef4bf2 TG |
51 | { |
52 | struct fib_lookup_arg arg = { | |
53 | .result = res, | |
ebc0ffae | 54 | .flags = FIB_LOOKUP_NOREF, |
e1ef4bf2 TG |
55 | }; |
56 | int err; | |
1da177e4 | 57 | |
22bd5b9b | 58 | err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg); |
85b91b03 DM |
59 | #ifdef CONFIG_IP_ROUTE_CLASSID |
60 | if (arg.rule) | |
61 | res->tclassid = ((struct fib4_rule *)arg.rule)->tclassid; | |
62 | else | |
63 | res->tclassid = 0; | |
64 | #endif | |
e1ef4bf2 TG |
65 | return err; |
66 | } | |
f4530fa5 | 67 | EXPORT_SYMBOL_GPL(__fib_lookup); |
e1ef4bf2 | 68 | |
8ce11e6a AB |
69 | static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp, |
70 | int flags, struct fib_lookup_arg *arg) | |
1da177e4 | 71 | { |
e1ef4bf2 TG |
72 | int err = -EAGAIN; |
73 | struct fib_table *tbl; | |
74 | ||
75 | switch (rule->action) { | |
76 | case FR_ACT_TO_TBL: | |
77 | break; | |
78 | ||
79 | case FR_ACT_UNREACHABLE: | |
80 | err = -ENETUNREACH; | |
81 | goto errout; | |
82 | ||
83 | case FR_ACT_PROHIBIT: | |
84 | err = -EACCES; | |
85 | goto errout; | |
86 | ||
87 | case FR_ACT_BLACKHOLE: | |
88 | default: | |
89 | err = -EINVAL; | |
90 | goto errout; | |
1da177e4 | 91 | } |
e1ef4bf2 | 92 | |
6a31d2a9 ED |
93 | tbl = fib_get_table(rule->fr_net, rule->table); |
94 | if (!tbl) | |
e1ef4bf2 TG |
95 | goto errout; |
96 | ||
22bd5b9b | 97 | err = fib_table_lookup(tbl, &flp->u.ip4, (struct fib_result *) arg->result, arg->flags); |
e1ef4bf2 TG |
98 | if (err > 0) |
99 | err = -EAGAIN; | |
100 | errout: | |
1da177e4 LT |
101 | return err; |
102 | } | |
103 | ||
7764a45a ST |
104 | static bool fib4_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg) |
105 | { | |
6ef94cfa ST |
106 | struct fib_result *result = (struct fib_result *) arg->result; |
107 | struct net_device *dev = result->fi->fib_dev; | |
108 | ||
7764a45a ST |
109 | /* do not accept result if the route does |
110 | * not meet the required prefix length | |
111 | */ | |
73f5698e | 112 | if (result->prefixlen <= rule->suppress_prefixlen) |
6ef94cfa ST |
113 | goto suppress_route; |
114 | ||
115 | /* do not accept result if the route uses a device | |
116 | * belonging to a forbidden interface group | |
117 | */ | |
118 | if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup) | |
119 | goto suppress_route; | |
120 | ||
7764a45a | 121 | return false; |
6ef94cfa ST |
122 | |
123 | suppress_route: | |
124 | if (!(arg->flags & FIB_LOOKUP_NOREF)) | |
125 | fib_info_put(result->fi); | |
126 | return true; | |
7764a45a | 127 | } |
e1ef4bf2 | 128 | |
e1ef4bf2 TG |
129 | static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags) |
130 | { | |
131 | struct fib4_rule *r = (struct fib4_rule *) rule; | |
9ade2286 DM |
132 | struct flowi4 *fl4 = &fl->u.ip4; |
133 | __be32 daddr = fl4->daddr; | |
134 | __be32 saddr = fl4->saddr; | |
e1ef4bf2 TG |
135 | |
136 | if (((saddr ^ r->src) & r->srcmask) || | |
137 | ((daddr ^ r->dst) & r->dstmask)) | |
138 | return 0; | |
139 | ||
9ade2286 | 140 | if (r->tos && (r->tos != fl4->flowi4_tos)) |
e1ef4bf2 TG |
141 | return 0; |
142 | ||
e1ef4bf2 TG |
143 | return 1; |
144 | } | |
1da177e4 | 145 | |
8ad4942c | 146 | static struct fib_table *fib_empty_table(struct net *net) |
1da177e4 | 147 | { |
2dfe55b4 | 148 | u32 id; |
1da177e4 LT |
149 | |
150 | for (id = 1; id <= RT_TABLE_MAX; id++) | |
8ad4942c DL |
151 | if (fib_get_table(net, id) == NULL) |
152 | return fib_new_table(net, id); | |
1da177e4 LT |
153 | return NULL; |
154 | } | |
155 | ||
ef7c79ed | 156 | static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = { |
1f6c9557 | 157 | FRA_GENERIC_POLICY, |
e1ef4bf2 TG |
158 | [FRA_FLOW] = { .type = NLA_U32 }, |
159 | }; | |
7b204afd | 160 | |
e1ef4bf2 | 161 | static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb, |
8b3521ee | 162 | struct fib_rule_hdr *frh, |
e1ef4bf2 | 163 | struct nlattr **tb) |
1da177e4 | 164 | { |
3b1e0a65 | 165 | struct net *net = sock_net(skb->sk); |
e1ef4bf2 TG |
166 | int err = -EINVAL; |
167 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
1da177e4 | 168 | |
e1701c68 | 169 | if (frh->tos & ~IPTOS_TOS_MASK) |
e1ef4bf2 | 170 | goto errout; |
7b204afd | 171 | |
e1ef4bf2 TG |
172 | if (rule->table == RT_TABLE_UNSPEC) { |
173 | if (rule->action == FR_ACT_TO_TBL) { | |
174 | struct fib_table *table; | |
1da177e4 | 175 | |
e4e4971c | 176 | table = fib_empty_table(net); |
e1ef4bf2 TG |
177 | if (table == NULL) { |
178 | err = -ENOBUFS; | |
179 | goto errout; | |
180 | } | |
1da177e4 | 181 | |
e1ef4bf2 | 182 | rule->table = table->tb_id; |
1da177e4 LT |
183 | } |
184 | } | |
185 | ||
e1701c68 | 186 | if (frh->src_len) |
45d60b9e | 187 | rule4->src = nla_get_be32(tb[FRA_SRC]); |
7b204afd | 188 | |
e1701c68 | 189 | if (frh->dst_len) |
45d60b9e | 190 | rule4->dst = nla_get_be32(tb[FRA_DST]); |
7b204afd | 191 | |
c7066f70 | 192 | #ifdef CONFIG_IP_ROUTE_CLASSID |
7a9bc9b8 | 193 | if (tb[FRA_FLOW]) { |
e1ef4bf2 | 194 | rule4->tclassid = nla_get_u32(tb[FRA_FLOW]); |
7a9bc9b8 | 195 | if (rule4->tclassid) |
f4530fa5 | 196 | net->ipv4.fib_num_tclassid_users++; |
7a9bc9b8 | 197 | } |
1da177e4 LT |
198 | #endif |
199 | ||
e1ef4bf2 TG |
200 | rule4->src_len = frh->src_len; |
201 | rule4->srcmask = inet_make_mask(rule4->src_len); | |
202 | rule4->dst_len = frh->dst_len; | |
203 | rule4->dstmask = inet_make_mask(rule4->dst_len); | |
204 | rule4->tos = frh->tos; | |
7b204afd | 205 | |
f4530fa5 | 206 | net->ipv4.fib_has_custom_rules = true; |
e1ef4bf2 TG |
207 | err = 0; |
208 | errout: | |
209 | return err; | |
1da177e4 LT |
210 | } |
211 | ||
7a9bc9b8 DM |
212 | static void fib4_rule_delete(struct fib_rule *rule) |
213 | { | |
f4530fa5 | 214 | struct net *net = rule->fr_net; |
7a9bc9b8 DM |
215 | #ifdef CONFIG_IP_ROUTE_CLASSID |
216 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
217 | ||
218 | if (rule4->tclassid) | |
f4530fa5 | 219 | net->ipv4.fib_num_tclassid_users--; |
7a9bc9b8 | 220 | #endif |
f4530fa5 | 221 | net->ipv4.fib_has_custom_rules = true; |
7a9bc9b8 DM |
222 | } |
223 | ||
e1ef4bf2 TG |
224 | static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, |
225 | struct nlattr **tb) | |
1da177e4 | 226 | { |
e1ef4bf2 | 227 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; |
1da177e4 | 228 | |
e1ef4bf2 TG |
229 | if (frh->src_len && (rule4->src_len != frh->src_len)) |
230 | return 0; | |
1da177e4 | 231 | |
e1ef4bf2 TG |
232 | if (frh->dst_len && (rule4->dst_len != frh->dst_len)) |
233 | return 0; | |
7b204afd | 234 | |
e1ef4bf2 TG |
235 | if (frh->tos && (rule4->tos != frh->tos)) |
236 | return 0; | |
7b204afd | 237 | |
c7066f70 | 238 | #ifdef CONFIG_IP_ROUTE_CLASSID |
e1ef4bf2 TG |
239 | if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW]))) |
240 | return 0; | |
241 | #endif | |
1da177e4 | 242 | |
e1701c68 | 243 | if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC]))) |
e1ef4bf2 | 244 | return 0; |
1da177e4 | 245 | |
e1701c68 | 246 | if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST]))) |
e1ef4bf2 | 247 | return 0; |
1da177e4 | 248 | |
e1ef4bf2 | 249 | return 1; |
1da177e4 LT |
250 | } |
251 | ||
e1ef4bf2 | 252 | static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb, |
04af8cf6 | 253 | struct fib_rule_hdr *frh) |
e1ef4bf2 TG |
254 | { |
255 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
1da177e4 | 256 | |
e1ef4bf2 TG |
257 | frh->dst_len = rule4->dst_len; |
258 | frh->src_len = rule4->src_len; | |
259 | frh->tos = rule4->tos; | |
1da177e4 | 260 | |
f3756b79 DM |
261 | if ((rule4->dst_len && |
262 | nla_put_be32(skb, FRA_DST, rule4->dst)) || | |
263 | (rule4->src_len && | |
264 | nla_put_be32(skb, FRA_SRC, rule4->src))) | |
265 | goto nla_put_failure; | |
c7066f70 | 266 | #ifdef CONFIG_IP_ROUTE_CLASSID |
f3756b79 DM |
267 | if (rule4->tclassid && |
268 | nla_put_u32(skb, FRA_FLOW, rule4->tclassid)) | |
269 | goto nla_put_failure; | |
1da177e4 | 270 | #endif |
e1ef4bf2 | 271 | return 0; |
1da177e4 | 272 | |
e1ef4bf2 TG |
273 | nla_put_failure: |
274 | return -ENOBUFS; | |
1da177e4 LT |
275 | } |
276 | ||
339bf98f TG |
277 | static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule) |
278 | { | |
279 | return nla_total_size(4) /* dst */ | |
280 | + nla_total_size(4) /* src */ | |
281 | + nla_total_size(4); /* flow */ | |
282 | } | |
283 | ||
ae299fc0 | 284 | static void fib4_rule_flush_cache(struct fib_rules_ops *ops) |
73417f61 | 285 | { |
bafa6d9d | 286 | rt_cache_flush(ops->fro_net); |
73417f61 TG |
287 | } |
288 | ||
04a6f82c | 289 | static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = { |
25239cee | 290 | .family = AF_INET, |
e1ef4bf2 | 291 | .rule_size = sizeof(struct fib4_rule), |
e1701c68 | 292 | .addr_size = sizeof(u32), |
e1ef4bf2 | 293 | .action = fib4_rule_action, |
7764a45a | 294 | .suppress = fib4_rule_suppress, |
e1ef4bf2 TG |
295 | .match = fib4_rule_match, |
296 | .configure = fib4_rule_configure, | |
7a9bc9b8 | 297 | .delete = fib4_rule_delete, |
e1ef4bf2 TG |
298 | .compare = fib4_rule_compare, |
299 | .fill = fib4_rule_fill, | |
d8a566be | 300 | .default_pref = fib_default_rule_pref, |
339bf98f | 301 | .nlmsg_payload = fib4_rule_nlmsg_payload, |
73417f61 | 302 | .flush_cache = fib4_rule_flush_cache, |
e1ef4bf2 TG |
303 | .nlgroup = RTNLGRP_IPV4_RULE, |
304 | .policy = fib4_rule_policy, | |
e1ef4bf2 TG |
305 | .owner = THIS_MODULE, |
306 | }; | |
307 | ||
e4e4971c | 308 | static int fib_default_rules_init(struct fib_rules_ops *ops) |
1da177e4 | 309 | { |
2994c638 DL |
310 | int err; |
311 | ||
5adef180 | 312 | err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0); |
2994c638 DL |
313 | if (err < 0) |
314 | return err; | |
e4e4971c | 315 | err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0); |
2994c638 DL |
316 | if (err < 0) |
317 | return err; | |
e4e4971c | 318 | err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0); |
2994c638 DL |
319 | if (err < 0) |
320 | return err; | |
321 | return 0; | |
322 | } | |
1da177e4 | 323 | |
7b1a74fd | 324 | int __net_init fib4_rules_init(struct net *net) |
2994c638 | 325 | { |
dbb50165 | 326 | int err; |
e4e4971c DL |
327 | struct fib_rules_ops *ops; |
328 | ||
e9c5158a EB |
329 | ops = fib_rules_register(&fib4_rules_ops_template, net); |
330 | if (IS_ERR(ops)) | |
331 | return PTR_ERR(ops); | |
dbb50165 | 332 | |
e4e4971c | 333 | err = fib_default_rules_init(ops); |
dbb50165 DL |
334 | if (err < 0) |
335 | goto fail; | |
e4e4971c | 336 | net->ipv4.rules_ops = ops; |
f4530fa5 | 337 | net->ipv4.fib_has_custom_rules = false; |
dbb50165 DL |
338 | return 0; |
339 | ||
340 | fail: | |
341 | /* also cleans all rules already added */ | |
9e3a5487 | 342 | fib_rules_unregister(ops); |
dbb50165 | 343 | return err; |
1da177e4 | 344 | } |
7b1a74fd DL |
345 | |
346 | void __net_exit fib4_rules_exit(struct net *net) | |
347 | { | |
9e3a5487 | 348 | fib_rules_unregister(net->ipv4.rules_ops); |
7b1a74fd | 349 | } |