]>
Commit | Line | Data |
---|---|---|
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 | * | |
8 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> | |
9 | * Thomas Graf <tgraf@suug.ch> | |
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 | ||
21 | #include <linux/types.h> | |
22 | #include <linux/kernel.h> | |
23 | #include <linux/netdevice.h> | |
24 | #include <linux/netlink.h> | |
25 | #include <linux/inetdevice.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/list.h> | |
28 | #include <linux/rcupdate.h> | |
29 | #include <net/ip.h> | |
30 | #include <net/route.h> | |
31 | #include <net/tcp.h> | |
32 | #include <net/ip_fib.h> | |
33 | #include <net/fib_rules.h> | |
34 | ||
35 | struct fib4_rule | |
36 | { | |
37 | struct fib_rule common; | |
38 | u8 dst_len; | |
39 | u8 src_len; | |
40 | u8 tos; | |
41 | __be32 src; | |
42 | __be32 srcmask; | |
43 | __be32 dst; | |
44 | __be32 dstmask; | |
45 | #ifdef CONFIG_NET_CLS_ROUTE | |
46 | u32 tclassid; | |
47 | #endif | |
48 | }; | |
49 | ||
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 | |
56 | ||
57 | int fib_lookup(struct net *net, struct flowi *flp, struct fib_result *res) | |
58 | { | |
59 | struct fib_lookup_arg arg = { | |
60 | .result = res, | |
61 | }; | |
62 | int err; | |
63 | ||
64 | err = fib_rules_lookup(net->ipv4.rules_ops, flp, 0, &arg); | |
65 | res->r = arg.rule; | |
66 | ||
67 | return err; | |
68 | } | |
69 | ||
70 | static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp, | |
71 | int flags, struct fib_lookup_arg *arg) | |
72 | { | |
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; | |
92 | } | |
93 | ||
94 | if ((tbl = fib_get_table(rule->fr_net, rule->table)) == NULL) | |
95 | goto errout; | |
96 | ||
97 | err = fib_table_lookup(tbl, flp, (struct fib_result *) arg->result); | |
98 | if (err > 0) | |
99 | err = -EAGAIN; | |
100 | errout: | |
101 | return err; | |
102 | } | |
103 | ||
104 | ||
105 | static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags) | |
106 | { | |
107 | struct fib4_rule *r = (struct fib4_rule *) rule; | |
108 | __be32 daddr = fl->fl4_dst; | |
109 | __be32 saddr = fl->fl4_src; | |
110 | ||
111 | if (((saddr ^ r->src) & r->srcmask) || | |
112 | ((daddr ^ r->dst) & r->dstmask)) | |
113 | return 0; | |
114 | ||
115 | if (r->tos && (r->tos != fl->fl4_tos)) | |
116 | return 0; | |
117 | ||
118 | return 1; | |
119 | } | |
120 | ||
121 | static struct fib_table *fib_empty_table(struct net *net) | |
122 | { | |
123 | u32 id; | |
124 | ||
125 | for (id = 1; id <= RT_TABLE_MAX; id++) | |
126 | if (fib_get_table(net, id) == NULL) | |
127 | return fib_new_table(net, id); | |
128 | return NULL; | |
129 | } | |
130 | ||
131 | static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = { | |
132 | FRA_GENERIC_POLICY, | |
133 | [FRA_FLOW] = { .type = NLA_U32 }, | |
134 | }; | |
135 | ||
136 | static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb, | |
137 | struct fib_rule_hdr *frh, | |
138 | struct nlattr **tb) | |
139 | { | |
140 | struct net *net = sock_net(skb->sk); | |
141 | int err = -EINVAL; | |
142 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
143 | ||
144 | if (frh->tos & ~IPTOS_TOS_MASK) | |
145 | goto errout; | |
146 | ||
147 | if (rule->table == RT_TABLE_UNSPEC) { | |
148 | if (rule->action == FR_ACT_TO_TBL) { | |
149 | struct fib_table *table; | |
150 | ||
151 | table = fib_empty_table(net); | |
152 | if (table == NULL) { | |
153 | err = -ENOBUFS; | |
154 | goto errout; | |
155 | } | |
156 | ||
157 | rule->table = table->tb_id; | |
158 | } | |
159 | } | |
160 | ||
161 | if (frh->src_len) | |
162 | rule4->src = nla_get_be32(tb[FRA_SRC]); | |
163 | ||
164 | if (frh->dst_len) | |
165 | rule4->dst = nla_get_be32(tb[FRA_DST]); | |
166 | ||
167 | #ifdef CONFIG_NET_CLS_ROUTE | |
168 | if (tb[FRA_FLOW]) | |
169 | rule4->tclassid = nla_get_u32(tb[FRA_FLOW]); | |
170 | #endif | |
171 | ||
172 | rule4->src_len = frh->src_len; | |
173 | rule4->srcmask = inet_make_mask(rule4->src_len); | |
174 | rule4->dst_len = frh->dst_len; | |
175 | rule4->dstmask = inet_make_mask(rule4->dst_len); | |
176 | rule4->tos = frh->tos; | |
177 | ||
178 | err = 0; | |
179 | errout: | |
180 | return err; | |
181 | } | |
182 | ||
183 | static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, | |
184 | struct nlattr **tb) | |
185 | { | |
186 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
187 | ||
188 | if (frh->src_len && (rule4->src_len != frh->src_len)) | |
189 | return 0; | |
190 | ||
191 | if (frh->dst_len && (rule4->dst_len != frh->dst_len)) | |
192 | return 0; | |
193 | ||
194 | if (frh->tos && (rule4->tos != frh->tos)) | |
195 | return 0; | |
196 | ||
197 | #ifdef CONFIG_NET_CLS_ROUTE | |
198 | if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW]))) | |
199 | return 0; | |
200 | #endif | |
201 | ||
202 | if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC]))) | |
203 | return 0; | |
204 | ||
205 | if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST]))) | |
206 | return 0; | |
207 | ||
208 | return 1; | |
209 | } | |
210 | ||
211 | static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb, | |
212 | struct fib_rule_hdr *frh) | |
213 | { | |
214 | struct fib4_rule *rule4 = (struct fib4_rule *) rule; | |
215 | ||
216 | frh->dst_len = rule4->dst_len; | |
217 | frh->src_len = rule4->src_len; | |
218 | frh->tos = rule4->tos; | |
219 | ||
220 | if (rule4->dst_len) | |
221 | NLA_PUT_BE32(skb, FRA_DST, rule4->dst); | |
222 | ||
223 | if (rule4->src_len) | |
224 | NLA_PUT_BE32(skb, FRA_SRC, rule4->src); | |
225 | ||
226 | #ifdef CONFIG_NET_CLS_ROUTE | |
227 | if (rule4->tclassid) | |
228 | NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid); | |
229 | #endif | |
230 | return 0; | |
231 | ||
232 | nla_put_failure: | |
233 | return -ENOBUFS; | |
234 | } | |
235 | ||
236 | static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule) | |
237 | { | |
238 | return nla_total_size(4) /* dst */ | |
239 | + nla_total_size(4) /* src */ | |
240 | + nla_total_size(4); /* flow */ | |
241 | } | |
242 | ||
243 | static void fib4_rule_flush_cache(struct fib_rules_ops *ops) | |
244 | { | |
245 | rt_cache_flush(ops->fro_net, -1); | |
246 | } | |
247 | ||
248 | static struct fib_rules_ops fib4_rules_ops_template = { | |
249 | .family = AF_INET, | |
250 | .rule_size = sizeof(struct fib4_rule), | |
251 | .addr_size = sizeof(u32), | |
252 | .action = fib4_rule_action, | |
253 | .match = fib4_rule_match, | |
254 | .configure = fib4_rule_configure, | |
255 | .compare = fib4_rule_compare, | |
256 | .fill = fib4_rule_fill, | |
257 | .default_pref = fib_default_rule_pref, | |
258 | .nlmsg_payload = fib4_rule_nlmsg_payload, | |
259 | .flush_cache = fib4_rule_flush_cache, | |
260 | .nlgroup = RTNLGRP_IPV4_RULE, | |
261 | .policy = fib4_rule_policy, | |
262 | .owner = THIS_MODULE, | |
263 | }; | |
264 | ||
265 | static int fib_default_rules_init(struct fib_rules_ops *ops) | |
266 | { | |
267 | int err; | |
268 | ||
269 | err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0); | |
270 | if (err < 0) | |
271 | return err; | |
272 | err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0); | |
273 | if (err < 0) | |
274 | return err; | |
275 | err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0); | |
276 | if (err < 0) | |
277 | return err; | |
278 | return 0; | |
279 | } | |
280 | ||
281 | int __net_init fib4_rules_init(struct net *net) | |
282 | { | |
283 | int err; | |
284 | struct fib_rules_ops *ops; | |
285 | ||
286 | ops = fib_rules_register(&fib4_rules_ops_template, net); | |
287 | if (IS_ERR(ops)) | |
288 | return PTR_ERR(ops); | |
289 | ||
290 | err = fib_default_rules_init(ops); | |
291 | if (err < 0) | |
292 | goto fail; | |
293 | net->ipv4.rules_ops = ops; | |
294 | return 0; | |
295 | ||
296 | fail: | |
297 | /* also cleans all rules already added */ | |
298 | fib_rules_unregister(ops); | |
299 | return err; | |
300 | } | |
301 | ||
302 | void __net_exit fib4_rules_exit(struct net *net) | |
303 | { | |
304 | fib_rules_unregister(net->ipv4.rules_ops); | |
305 | } |