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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 | static struct fib_rules_ops fib4_rules_ops; |
1da177e4 | 36 | |
e1ef4bf2 | 37 | struct fib4_rule |
1da177e4 | 38 | { |
e1ef4bf2 TG |
39 | struct fib_rule common; |
40 | u8 dst_len; | |
41 | u8 src_len; | |
42 | u8 tos; | |
81f7bf6c AV |
43 | __be32 src; |
44 | __be32 srcmask; | |
45 | __be32 dst; | |
46 | __be32 dstmask; | |
1da177e4 | 47 | #ifdef CONFIG_NET_CLS_ROUTE |
e1ef4bf2 | 48 | u32 tclassid; |
1da177e4 | 49 | #endif |
1da177e4 LT |
50 | }; |
51 | ||
e1ef4bf2 TG |
52 | #ifdef CONFIG_NET_CLS_ROUTE |
53 | u32 fib_rules_tclass(struct fib_result *res) | |
54 | { | |
55 | return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0; | |
56 | } | |
57 | #endif | |
7b204afd | 58 | |
e1ef4bf2 TG |
59 | int fib_lookup(struct flowi *flp, struct fib_result *res) |
60 | { | |
61 | struct fib_lookup_arg arg = { | |
62 | .result = res, | |
63 | }; | |
64 | int err; | |
1da177e4 | 65 | |
e1ef4bf2 TG |
66 | err = fib_rules_lookup(&fib4_rules_ops, flp, 0, &arg); |
67 | res->r = arg.rule; | |
a5cdc030 | 68 | |
e1ef4bf2 TG |
69 | return err; |
70 | } | |
71 | ||
8ce11e6a AB |
72 | static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp, |
73 | int flags, struct fib_lookup_arg *arg) | |
1da177e4 | 74 | { |
e1ef4bf2 TG |
75 | int err = -EAGAIN; |
76 | struct fib_table *tbl; | |
77 | ||
78 | switch (rule->action) { | |
79 | case FR_ACT_TO_TBL: | |
80 | break; | |
81 | ||
82 | case FR_ACT_UNREACHABLE: | |
83 | err = -ENETUNREACH; | |
84 | goto errout; | |
85 | ||
86 | case FR_ACT_PROHIBIT: | |
87 | err = -EACCES; | |
88 | goto errout; | |
89 | ||
90 | case FR_ACT_BLACKHOLE: | |
91 | default: | |
92 | err = -EINVAL; | |
93 | goto errout; | |
1da177e4 | 94 | } |
e1ef4bf2 | 95 | |
8ad4942c | 96 | if ((tbl = fib_get_table(&init_net, rule->table)) == NULL) |
e1ef4bf2 TG |
97 | goto errout; |
98 | ||
99 | err = tbl->tb_lookup(tbl, flp, (struct fib_result *) arg->result); | |
100 | if (err > 0) | |
101 | err = -EAGAIN; | |
102 | errout: | |
1da177e4 LT |
103 | return err; |
104 | } | |
105 | ||
e1ef4bf2 TG |
106 | |
107 | void fib_select_default(const struct flowi *flp, struct fib_result *res) | |
108 | { | |
109 | if (res->r && res->r->action == FR_ACT_TO_TBL && | |
110 | FIB_RES_GW(*res) && FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) { | |
111 | struct fib_table *tb; | |
8ad4942c | 112 | if ((tb = fib_get_table(&init_net, res->r->table)) != NULL) |
e1ef4bf2 TG |
113 | tb->tb_select_default(tb, flp, res); |
114 | } | |
115 | } | |
116 | ||
117 | static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags) | |
118 | { | |
119 | struct fib4_rule *r = (struct fib4_rule *) rule; | |
81f7bf6c AV |
120 | __be32 daddr = fl->fl4_dst; |
121 | __be32 saddr = fl->fl4_src; | |
e1ef4bf2 TG |
122 | |
123 | if (((saddr ^ r->src) & r->srcmask) || | |
124 | ((daddr ^ r->dst) & r->dstmask)) | |
125 | return 0; | |
126 | ||
127 | if (r->tos && (r->tos != fl->fl4_tos)) | |
128 | return 0; | |
129 | ||
e1ef4bf2 TG |
130 | return 1; |
131 | } | |
1da177e4 | 132 | |
8ad4942c | 133 | static struct fib_table *fib_empty_table(struct net *net) |
1da177e4 | 134 | { |
2dfe55b4 | 135 | u32 id; |
1da177e4 LT |
136 | |
137 | for (id = 1; id <= RT_TABLE_MAX; id++) | |
8ad4942c DL |
138 | if (fib_get_table(net, id) == NULL) |
139 | return fib_new_table(net, id); | |
1da177e4 LT |
140 | return NULL; |
141 | } | |
142 | ||
ef7c79ed | 143 | static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = { |
1f6c9557 | 144 | FRA_GENERIC_POLICY, |
e1ef4bf2 TG |
145 | [FRA_FLOW] = { .type = NLA_U32 }, |
146 | }; | |
7b204afd | 147 | |
e1ef4bf2 TG |
148 | static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb, |
149 | struct nlmsghdr *nlh, struct fib_rule_hdr *frh, | |
150 | struct nlattr **tb) | |
1da177e4 | 151 | { |
e1ef4bf2 TG |
152 | int err = -EINVAL; |
153 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
1da177e4 | 154 | |
e1701c68 | 155 | if (frh->tos & ~IPTOS_TOS_MASK) |
e1ef4bf2 | 156 | goto errout; |
7b204afd | 157 | |
e1ef4bf2 TG |
158 | if (rule->table == RT_TABLE_UNSPEC) { |
159 | if (rule->action == FR_ACT_TO_TBL) { | |
160 | struct fib_table *table; | |
1da177e4 | 161 | |
8ad4942c | 162 | table = fib_empty_table(&init_net); |
e1ef4bf2 TG |
163 | if (table == NULL) { |
164 | err = -ENOBUFS; | |
165 | goto errout; | |
166 | } | |
1da177e4 | 167 | |
e1ef4bf2 | 168 | rule->table = table->tb_id; |
1da177e4 LT |
169 | } |
170 | } | |
171 | ||
e1701c68 | 172 | if (frh->src_len) |
45d60b9e | 173 | rule4->src = nla_get_be32(tb[FRA_SRC]); |
7b204afd | 174 | |
e1701c68 | 175 | if (frh->dst_len) |
45d60b9e | 176 | rule4->dst = nla_get_be32(tb[FRA_DST]); |
7b204afd | 177 | |
1da177e4 | 178 | #ifdef CONFIG_NET_CLS_ROUTE |
e1ef4bf2 TG |
179 | if (tb[FRA_FLOW]) |
180 | rule4->tclassid = nla_get_u32(tb[FRA_FLOW]); | |
1da177e4 LT |
181 | #endif |
182 | ||
e1ef4bf2 TG |
183 | rule4->src_len = frh->src_len; |
184 | rule4->srcmask = inet_make_mask(rule4->src_len); | |
185 | rule4->dst_len = frh->dst_len; | |
186 | rule4->dstmask = inet_make_mask(rule4->dst_len); | |
187 | rule4->tos = frh->tos; | |
7b204afd | 188 | |
e1ef4bf2 TG |
189 | err = 0; |
190 | errout: | |
191 | return err; | |
1da177e4 LT |
192 | } |
193 | ||
e1ef4bf2 TG |
194 | static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, |
195 | struct nlattr **tb) | |
1da177e4 | 196 | { |
e1ef4bf2 | 197 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; |
1da177e4 | 198 | |
e1ef4bf2 TG |
199 | if (frh->src_len && (rule4->src_len != frh->src_len)) |
200 | return 0; | |
1da177e4 | 201 | |
e1ef4bf2 TG |
202 | if (frh->dst_len && (rule4->dst_len != frh->dst_len)) |
203 | return 0; | |
7b204afd | 204 | |
e1ef4bf2 TG |
205 | if (frh->tos && (rule4->tos != frh->tos)) |
206 | return 0; | |
7b204afd | 207 | |
e1ef4bf2 TG |
208 | #ifdef CONFIG_NET_CLS_ROUTE |
209 | if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW]))) | |
210 | return 0; | |
211 | #endif | |
1da177e4 | 212 | |
e1701c68 | 213 | if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC]))) |
e1ef4bf2 | 214 | return 0; |
1da177e4 | 215 | |
e1701c68 | 216 | if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST]))) |
e1ef4bf2 | 217 | return 0; |
1da177e4 | 218 | |
e1ef4bf2 | 219 | return 1; |
1da177e4 LT |
220 | } |
221 | ||
e1ef4bf2 TG |
222 | static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb, |
223 | struct nlmsghdr *nlh, struct fib_rule_hdr *frh) | |
224 | { | |
225 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
1da177e4 | 226 | |
e1ef4bf2 TG |
227 | frh->family = AF_INET; |
228 | frh->dst_len = rule4->dst_len; | |
229 | frh->src_len = rule4->src_len; | |
230 | frh->tos = rule4->tos; | |
1da177e4 | 231 | |
e1ef4bf2 | 232 | if (rule4->dst_len) |
45d60b9e | 233 | NLA_PUT_BE32(skb, FRA_DST, rule4->dst); |
e1ef4bf2 TG |
234 | |
235 | if (rule4->src_len) | |
45d60b9e | 236 | NLA_PUT_BE32(skb, FRA_SRC, rule4->src); |
e1ef4bf2 | 237 | |
1da177e4 | 238 | #ifdef CONFIG_NET_CLS_ROUTE |
e1ef4bf2 TG |
239 | if (rule4->tclassid) |
240 | NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid); | |
1da177e4 | 241 | #endif |
e1ef4bf2 | 242 | return 0; |
1da177e4 | 243 | |
e1ef4bf2 TG |
244 | nla_put_failure: |
245 | return -ENOBUFS; | |
1da177e4 LT |
246 | } |
247 | ||
868d13ac | 248 | static u32 fib4_rule_default_pref(struct fib_rules_ops *ops) |
a5cdc030 | 249 | { |
e1ef4bf2 TG |
250 | struct list_head *pos; |
251 | struct fib_rule *rule; | |
252 | ||
76c72d4f DL |
253 | if (!list_empty(&fib4_rules_ops.rules_list)) { |
254 | pos = fib4_rules_ops.rules_list.next; | |
255 | if (pos->next != &fib4_rules_ops.rules_list) { | |
e1ef4bf2 TG |
256 | rule = list_entry(pos->next, struct fib_rule, list); |
257 | if (rule->pref) | |
258 | return rule->pref - 1; | |
259 | } | |
a5cdc030 | 260 | } |
e1ef4bf2 TG |
261 | |
262 | return 0; | |
a5cdc030 PM |
263 | } |
264 | ||
339bf98f TG |
265 | static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule) |
266 | { | |
267 | return nla_total_size(4) /* dst */ | |
268 | + nla_total_size(4) /* src */ | |
269 | + nla_total_size(4); /* flow */ | |
270 | } | |
271 | ||
73417f61 TG |
272 | static void fib4_rule_flush_cache(void) |
273 | { | |
4b19ca44 | 274 | rt_cache_flush(-1); |
73417f61 TG |
275 | } |
276 | ||
e1ef4bf2 TG |
277 | static struct fib_rules_ops fib4_rules_ops = { |
278 | .family = AF_INET, | |
279 | .rule_size = sizeof(struct fib4_rule), | |
e1701c68 | 280 | .addr_size = sizeof(u32), |
e1ef4bf2 TG |
281 | .action = fib4_rule_action, |
282 | .match = fib4_rule_match, | |
283 | .configure = fib4_rule_configure, | |
284 | .compare = fib4_rule_compare, | |
285 | .fill = fib4_rule_fill, | |
286 | .default_pref = fib4_rule_default_pref, | |
339bf98f | 287 | .nlmsg_payload = fib4_rule_nlmsg_payload, |
73417f61 | 288 | .flush_cache = fib4_rule_flush_cache, |
e1ef4bf2 TG |
289 | .nlgroup = RTNLGRP_IPV4_RULE, |
290 | .policy = fib4_rule_policy, | |
76c72d4f | 291 | .rules_list = LIST_HEAD_INIT(fib4_rules_ops.rules_list), |
e1ef4bf2 TG |
292 | .owner = THIS_MODULE, |
293 | }; | |
294 | ||
2994c638 | 295 | static int __init fib_default_rules_init(void) |
1da177e4 | 296 | { |
2994c638 DL |
297 | int err; |
298 | ||
299 | err = fib_default_rule_add(&fib4_rules_ops, 0, | |
300 | RT_TABLE_LOCAL, FIB_RULE_PERMANENT); | |
301 | if (err < 0) | |
302 | return err; | |
303 | err = fib_default_rule_add(&fib4_rules_ops, 0x7FFE, | |
304 | RT_TABLE_MAIN, 0); | |
305 | if (err < 0) | |
306 | return err; | |
307 | err = fib_default_rule_add(&fib4_rules_ops, 0x7FFF, | |
308 | RT_TABLE_DEFAULT, 0); | |
309 | if (err < 0) | |
310 | return err; | |
311 | return 0; | |
312 | } | |
1da177e4 | 313 | |
7b1a74fd | 314 | int __net_init fib4_rules_init(struct net *net) |
2994c638 | 315 | { |
dbb50165 DL |
316 | int err; |
317 | ||
7b1a74fd | 318 | fib_rules_register(net, &fib4_rules_ops); |
dbb50165 DL |
319 | err = fib_default_rules_init(); |
320 | if (err < 0) | |
321 | goto fail; | |
322 | return 0; | |
323 | ||
324 | fail: | |
325 | /* also cleans all rules already added */ | |
7b1a74fd | 326 | fib_rules_unregister(net, &fib4_rules_ops); |
dbb50165 | 327 | return err; |
1da177e4 | 328 | } |
7b1a74fd DL |
329 | |
330 | void __net_exit fib4_rules_exit(struct net *net) | |
331 | { | |
332 | fib_rules_unregister(net, &fib4_rules_ops); | |
333 | } |