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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> |
e1ef4bf2 | 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: | |
17 | * Rani Assaf : local_rule cannot be deleted | |
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> | |
1da177e4 | 29 | #include <net/ip.h> |
1da177e4 LT |
30 | #include <net/route.h> |
31 | #include <net/tcp.h> | |
1da177e4 | 32 | #include <net/ip_fib.h> |
e1ef4bf2 | 33 | #include <net/fib_rules.h> |
1da177e4 | 34 | |
e1ef4bf2 | 35 | struct fib4_rule |
1da177e4 | 36 | { |
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; | |
1da177e4 | 45 | #ifdef CONFIG_NET_CLS_ROUTE |
e1ef4bf2 | 46 | u32 tclassid; |
1da177e4 | 47 | #endif |
1da177e4 LT |
48 | }; |
49 | ||
e1ef4bf2 TG |
50 | #ifdef CONFIG_NET_CLS_ROUTE |
51 | u32 fib_rules_tclass(struct fib_result *res) | |
52 | { | |
53 | return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0; | |
54 | } | |
55 | #endif | |
7b204afd | 56 | |
e1ef4bf2 TG |
57 | int fib_lookup(struct flowi *flp, struct fib_result *res) |
58 | { | |
59 | struct fib_lookup_arg arg = { | |
60 | .result = res, | |
61 | }; | |
62 | int err; | |
1da177e4 | 63 | |
e4e4971c | 64 | err = fib_rules_lookup(init_net.ipv4.rules_ops, flp, 0, &arg); |
e1ef4bf2 | 65 | res->r = arg.rule; |
a5cdc030 | 66 | |
e1ef4bf2 TG |
67 | return err; |
68 | } | |
69 | ||
8ce11e6a AB |
70 | static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp, |
71 | int flags, struct fib_lookup_arg *arg) | |
1da177e4 | 72 | { |
e1ef4bf2 TG |
73 | int err = -EAGAIN; |
74 | struct fib_table *tbl; | |
75 | ||
76 | switch (rule->action) { | |
77 | case FR_ACT_TO_TBL: | |
78 | break; | |
79 | ||
80 | case FR_ACT_UNREACHABLE: | |
81 | err = -ENETUNREACH; | |
82 | goto errout; | |
83 | ||
84 | case FR_ACT_PROHIBIT: | |
85 | err = -EACCES; | |
86 | goto errout; | |
87 | ||
88 | case FR_ACT_BLACKHOLE: | |
89 | default: | |
90 | err = -EINVAL; | |
91 | goto errout; | |
1da177e4 | 92 | } |
e1ef4bf2 | 93 | |
8ad4942c | 94 | if ((tbl = fib_get_table(&init_net, rule->table)) == NULL) |
e1ef4bf2 TG |
95 | goto errout; |
96 | ||
97 | err = tbl->tb_lookup(tbl, flp, (struct fib_result *) arg->result); | |
98 | if (err > 0) | |
99 | err = -EAGAIN; | |
100 | errout: | |
1da177e4 LT |
101 | return err; |
102 | } | |
103 | ||
e1ef4bf2 TG |
104 | |
105 | void fib_select_default(const struct flowi *flp, struct fib_result *res) | |
106 | { | |
107 | if (res->r && res->r->action == FR_ACT_TO_TBL && | |
108 | FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) { | |
109 | struct fib_table *tb; | |
8ad4942c | 110 | if ((tb = fib_get_table(&init_net, res->r->table)) != NULL) |
e1ef4bf2 TG |
111 | tb->tb_select_default(tb, flp, res); |
112 | } | |
113 | } | |
114 | ||
115 | static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags) | |
116 | { | |
117 | struct fib4_rule *r = (struct fib4_rule *) rule; | |
81f7bf6c AV |
118 | __be32 daddr = fl->fl4_dst; |
119 | __be32 saddr = fl->fl4_src; | |
e1ef4bf2 TG |
120 | |
121 | if (((saddr ^ r->src) & r->srcmask) || | |
122 | ((daddr ^ r->dst) & r->dstmask)) | |
123 | return 0; | |
124 | ||
125 | if (r->tos && (r->tos != fl->fl4_tos)) | |
126 | return 0; | |
127 | ||
e1ef4bf2 TG |
128 | return 1; |
129 | } | |
1da177e4 | 130 | |
8ad4942c | 131 | static struct fib_table *fib_empty_table(struct net *net) |
1da177e4 | 132 | { |
2dfe55b4 | 133 | u32 id; |
1da177e4 LT |
134 | |
135 | for (id = 1; id <= RT_TABLE_MAX; id++) | |
8ad4942c DL |
136 | if (fib_get_table(net, id) == NULL) |
137 | return fib_new_table(net, id); | |
1da177e4 LT |
138 | return NULL; |
139 | } | |
140 | ||
ef7c79ed | 141 | static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = { |
1f6c9557 | 142 | FRA_GENERIC_POLICY, |
e1ef4bf2 TG |
143 | [FRA_FLOW] = { .type = NLA_U32 }, |
144 | }; | |
7b204afd | 145 | |
e1ef4bf2 TG |
146 | static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb, |
147 | struct nlmsghdr *nlh, struct fib_rule_hdr *frh, | |
148 | struct nlattr **tb) | |
1da177e4 | 149 | { |
e4e4971c | 150 | struct net *net = skb->sk->sk_net; |
e1ef4bf2 TG |
151 | int err = -EINVAL; |
152 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
1da177e4 | 153 | |
e1701c68 | 154 | if (frh->tos & ~IPTOS_TOS_MASK) |
e1ef4bf2 | 155 | goto errout; |
7b204afd | 156 | |
e1ef4bf2 TG |
157 | if (rule->table == RT_TABLE_UNSPEC) { |
158 | if (rule->action == FR_ACT_TO_TBL) { | |
159 | struct fib_table *table; | |
1da177e4 | 160 | |
e4e4971c | 161 | table = fib_empty_table(net); |
e1ef4bf2 TG |
162 | if (table == NULL) { |
163 | err = -ENOBUFS; | |
164 | goto errout; | |
165 | } | |
1da177e4 | 166 | |
e1ef4bf2 | 167 | rule->table = table->tb_id; |
1da177e4 LT |
168 | } |
169 | } | |
170 | ||
e1701c68 | 171 | if (frh->src_len) |
45d60b9e | 172 | rule4->src = nla_get_be32(tb[FRA_SRC]); |
7b204afd | 173 | |
e1701c68 | 174 | if (frh->dst_len) |
45d60b9e | 175 | rule4->dst = nla_get_be32(tb[FRA_DST]); |
7b204afd | 176 | |
1da177e4 | 177 | #ifdef CONFIG_NET_CLS_ROUTE |
e1ef4bf2 TG |
178 | if (tb[FRA_FLOW]) |
179 | rule4->tclassid = nla_get_u32(tb[FRA_FLOW]); | |
1da177e4 LT |
180 | #endif |
181 | ||
e1ef4bf2 TG |
182 | rule4->src_len = frh->src_len; |
183 | rule4->srcmask = inet_make_mask(rule4->src_len); | |
184 | rule4->dst_len = frh->dst_len; | |
185 | rule4->dstmask = inet_make_mask(rule4->dst_len); | |
186 | rule4->tos = frh->tos; | |
7b204afd | 187 | |
e1ef4bf2 TG |
188 | err = 0; |
189 | errout: | |
190 | return err; | |
1da177e4 LT |
191 | } |
192 | ||
e1ef4bf2 TG |
193 | static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, |
194 | struct nlattr **tb) | |
1da177e4 | 195 | { |
e1ef4bf2 | 196 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; |
1da177e4 | 197 | |
e1ef4bf2 TG |
198 | if (frh->src_len && (rule4->src_len != frh->src_len)) |
199 | return 0; | |
1da177e4 | 200 | |
e1ef4bf2 TG |
201 | if (frh->dst_len && (rule4->dst_len != frh->dst_len)) |
202 | return 0; | |
7b204afd | 203 | |
e1ef4bf2 TG |
204 | if (frh->tos && (rule4->tos != frh->tos)) |
205 | return 0; | |
7b204afd | 206 | |
e1ef4bf2 TG |
207 | #ifdef CONFIG_NET_CLS_ROUTE |
208 | if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW]))) | |
209 | return 0; | |
210 | #endif | |
1da177e4 | 211 | |
e1701c68 | 212 | if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC]))) |
e1ef4bf2 | 213 | return 0; |
1da177e4 | 214 | |
e1701c68 | 215 | if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST]))) |
e1ef4bf2 | 216 | return 0; |
1da177e4 | 217 | |
e1ef4bf2 | 218 | return 1; |
1da177e4 LT |
219 | } |
220 | ||
e1ef4bf2 TG |
221 | static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb, |
222 | struct nlmsghdr *nlh, struct fib_rule_hdr *frh) | |
223 | { | |
224 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
1da177e4 | 225 | |
e1ef4bf2 TG |
226 | frh->family = AF_INET; |
227 | frh->dst_len = rule4->dst_len; | |
228 | frh->src_len = rule4->src_len; | |
229 | frh->tos = rule4->tos; | |
1da177e4 | 230 | |
e1ef4bf2 | 231 | if (rule4->dst_len) |
45d60b9e | 232 | NLA_PUT_BE32(skb, FRA_DST, rule4->dst); |
e1ef4bf2 TG |
233 | |
234 | if (rule4->src_len) | |
45d60b9e | 235 | NLA_PUT_BE32(skb, FRA_SRC, rule4->src); |
e1ef4bf2 | 236 | |
1da177e4 | 237 | #ifdef CONFIG_NET_CLS_ROUTE |
e1ef4bf2 TG |
238 | if (rule4->tclassid) |
239 | NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid); | |
1da177e4 | 240 | #endif |
e1ef4bf2 | 241 | return 0; |
1da177e4 | 242 | |
e1ef4bf2 TG |
243 | nla_put_failure: |
244 | return -ENOBUFS; | |
1da177e4 LT |
245 | } |
246 | ||
868d13ac | 247 | static u32 fib4_rule_default_pref(struct fib_rules_ops *ops) |
a5cdc030 | 248 | { |
e1ef4bf2 TG |
249 | struct list_head *pos; |
250 | struct fib_rule *rule; | |
251 | ||
e4e4971c DL |
252 | if (!list_empty(&ops->rules_list)) { |
253 | pos = ops->rules_list.next; | |
254 | if (pos->next != &ops->rules_list) { | |
e1ef4bf2 TG |
255 | rule = list_entry(pos->next, struct fib_rule, list); |
256 | if (rule->pref) | |
257 | return rule->pref - 1; | |
258 | } | |
a5cdc030 | 259 | } |
e1ef4bf2 TG |
260 | |
261 | return 0; | |
a5cdc030 PM |
262 | } |
263 | ||
339bf98f TG |
264 | static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule) |
265 | { | |
266 | return nla_total_size(4) /* dst */ | |
267 | + nla_total_size(4) /* src */ | |
268 | + nla_total_size(4); /* flow */ | |
269 | } | |
270 | ||
73417f61 TG |
271 | static void fib4_rule_flush_cache(void) |
272 | { | |
4b19ca44 | 273 | rt_cache_flush(-1); |
73417f61 TG |
274 | } |
275 | ||
e4e4971c | 276 | static struct fib_rules_ops fib4_rules_ops_template = { |
e1ef4bf2 TG |
277 | .family = AF_INET, |
278 | .rule_size = sizeof(struct fib4_rule), | |
e1701c68 | 279 | .addr_size = sizeof(u32), |
e1ef4bf2 TG |
280 | .action = fib4_rule_action, |
281 | .match = fib4_rule_match, | |
282 | .configure = fib4_rule_configure, | |
283 | .compare = fib4_rule_compare, | |
284 | .fill = fib4_rule_fill, | |
285 | .default_pref = fib4_rule_default_pref, | |
339bf98f | 286 | .nlmsg_payload = fib4_rule_nlmsg_payload, |
73417f61 | 287 | .flush_cache = fib4_rule_flush_cache, |
e1ef4bf2 TG |
288 | .nlgroup = RTNLGRP_IPV4_RULE, |
289 | .policy = fib4_rule_policy, | |
e1ef4bf2 TG |
290 | .owner = THIS_MODULE, |
291 | }; | |
292 | ||
e4e4971c | 293 | static int fib_default_rules_init(struct fib_rules_ops *ops) |
1da177e4 | 294 | { |
2994c638 DL |
295 | int err; |
296 | ||
e4e4971c | 297 | err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, FIB_RULE_PERMANENT); |
2994c638 DL |
298 | if (err < 0) |
299 | return err; | |
e4e4971c | 300 | err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0); |
2994c638 DL |
301 | if (err < 0) |
302 | return err; | |
e4e4971c | 303 | err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0); |
2994c638 DL |
304 | if (err < 0) |
305 | return err; | |
306 | return 0; | |
307 | } | |
1da177e4 | 308 | |
7b1a74fd | 309 | int __net_init fib4_rules_init(struct net *net) |
2994c638 | 310 | { |
dbb50165 | 311 | int err; |
e4e4971c DL |
312 | struct fib_rules_ops *ops; |
313 | ||
314 | ops = kmemdup(&fib4_rules_ops_template, sizeof(*ops), GFP_KERNEL); | |
315 | if (ops == NULL) | |
316 | return -ENOMEM; | |
317 | INIT_LIST_HEAD(&ops->rules_list); | |
03592383 DL |
318 | ops->fro_net = net; |
319 | ||
e4e4971c | 320 | fib_rules_register(net, ops); |
dbb50165 | 321 | |
e4e4971c | 322 | err = fib_default_rules_init(ops); |
dbb50165 DL |
323 | if (err < 0) |
324 | goto fail; | |
e4e4971c | 325 | net->ipv4.rules_ops = ops; |
dbb50165 DL |
326 | return 0; |
327 | ||
328 | fail: | |
329 | /* also cleans all rules already added */ | |
e4e4971c DL |
330 | fib_rules_unregister(net, ops); |
331 | kfree(ops); | |
dbb50165 | 332 | return err; |
1da177e4 | 333 | } |
7b1a74fd DL |
334 | |
335 | void __net_exit fib4_rules_exit(struct net *net) | |
336 | { | |
e4e4971c DL |
337 | fib_rules_unregister(net, net->ipv4.rules_ops); |
338 | kfree(net->ipv4.rules_ops); | |
7b1a74fd | 339 | } |