Loading...
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 <linux/export.h>
30#include <net/ip.h>
31#include <net/route.h>
32#include <net/tcp.h>
33#include <net/ip_fib.h>
34#include <net/fib_rules.h>
35
36struct fib4_rule {
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_IP_ROUTE_CLASSID
46 u32 tclassid;
47#endif
48};
49
50int __fib_lookup(struct net *net, struct flowi4 *flp, struct fib_result *res)
51{
52 struct fib_lookup_arg arg = {
53 .result = res,
54 .flags = FIB_LOOKUP_NOREF,
55 };
56 int err;
57
58 err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg);
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
65 return err;
66}
67EXPORT_SYMBOL_GPL(__fib_lookup);
68
69static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
70 int flags, struct fib_lookup_arg *arg)
71{
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;
91 }
92
93 tbl = fib_get_table(rule->fr_net, rule->table);
94 if (!tbl)
95 goto errout;
96
97 err = fib_table_lookup(tbl, &flp->u.ip4, (struct fib_result *) arg->result, arg->flags);
98 if (err > 0)
99 err = -EAGAIN;
100errout:
101 return err;
102}
103
104static bool fib4_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)
105{
106 struct fib_result *result = (struct fib_result *) arg->result;
107 struct net_device *dev = NULL;
108
109 if (result->fi)
110 dev = result->fi->fib_dev;
111
112 /* do not accept result if the route does
113 * not meet the required prefix length
114 */
115 if (result->prefixlen <= rule->suppress_prefixlen)
116 goto suppress_route;
117
118 /* do not accept result if the route uses a device
119 * belonging to a forbidden interface group
120 */
121 if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
122 goto suppress_route;
123
124 return false;
125
126suppress_route:
127 if (!(arg->flags & FIB_LOOKUP_NOREF))
128 fib_info_put(result->fi);
129 return true;
130}
131
132static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
133{
134 struct fib4_rule *r = (struct fib4_rule *) rule;
135 struct flowi4 *fl4 = &fl->u.ip4;
136 __be32 daddr = fl4->daddr;
137 __be32 saddr = fl4->saddr;
138
139 if (((saddr ^ r->src) & r->srcmask) ||
140 ((daddr ^ r->dst) & r->dstmask))
141 return 0;
142
143 if (r->tos && (r->tos != fl4->flowi4_tos))
144 return 0;
145
146 return 1;
147}
148
149static struct fib_table *fib_empty_table(struct net *net)
150{
151 u32 id;
152
153 for (id = 1; id <= RT_TABLE_MAX; id++)
154 if (fib_get_table(net, id) == NULL)
155 return fib_new_table(net, id);
156 return NULL;
157}
158
159static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
160 FRA_GENERIC_POLICY,
161 [FRA_FLOW] = { .type = NLA_U32 },
162};
163
164static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
165 struct fib_rule_hdr *frh,
166 struct nlattr **tb)
167{
168 struct net *net = sock_net(skb->sk);
169 int err = -EINVAL;
170 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
171
172 if (frh->tos & ~IPTOS_TOS_MASK)
173 goto errout;
174
175 if (rule->table == RT_TABLE_UNSPEC) {
176 if (rule->action == FR_ACT_TO_TBL) {
177 struct fib_table *table;
178
179 table = fib_empty_table(net);
180 if (table == NULL) {
181 err = -ENOBUFS;
182 goto errout;
183 }
184
185 rule->table = table->tb_id;
186 }
187 }
188
189 if (frh->src_len)
190 rule4->src = nla_get_be32(tb[FRA_SRC]);
191
192 if (frh->dst_len)
193 rule4->dst = nla_get_be32(tb[FRA_DST]);
194
195#ifdef CONFIG_IP_ROUTE_CLASSID
196 if (tb[FRA_FLOW]) {
197 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
198 if (rule4->tclassid)
199 net->ipv4.fib_num_tclassid_users++;
200 }
201#endif
202
203 rule4->src_len = frh->src_len;
204 rule4->srcmask = inet_make_mask(rule4->src_len);
205 rule4->dst_len = frh->dst_len;
206 rule4->dstmask = inet_make_mask(rule4->dst_len);
207 rule4->tos = frh->tos;
208
209 net->ipv4.fib_has_custom_rules = true;
210 err = 0;
211errout:
212 return err;
213}
214
215static void fib4_rule_delete(struct fib_rule *rule)
216{
217 struct net *net = rule->fr_net;
218#ifdef CONFIG_IP_ROUTE_CLASSID
219 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
220
221 if (rule4->tclassid)
222 net->ipv4.fib_num_tclassid_users--;
223#endif
224 net->ipv4.fib_has_custom_rules = true;
225}
226
227static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
228 struct nlattr **tb)
229{
230 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
231
232 if (frh->src_len && (rule4->src_len != frh->src_len))
233 return 0;
234
235 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
236 return 0;
237
238 if (frh->tos && (rule4->tos != frh->tos))
239 return 0;
240
241#ifdef CONFIG_IP_ROUTE_CLASSID
242 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
243 return 0;
244#endif
245
246 if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC])))
247 return 0;
248
249 if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST])))
250 return 0;
251
252 return 1;
253}
254
255static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
256 struct fib_rule_hdr *frh)
257{
258 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
259
260 frh->dst_len = rule4->dst_len;
261 frh->src_len = rule4->src_len;
262 frh->tos = rule4->tos;
263
264 if ((rule4->dst_len &&
265 nla_put_be32(skb, FRA_DST, rule4->dst)) ||
266 (rule4->src_len &&
267 nla_put_be32(skb, FRA_SRC, rule4->src)))
268 goto nla_put_failure;
269#ifdef CONFIG_IP_ROUTE_CLASSID
270 if (rule4->tclassid &&
271 nla_put_u32(skb, FRA_FLOW, rule4->tclassid))
272 goto nla_put_failure;
273#endif
274 return 0;
275
276nla_put_failure:
277 return -ENOBUFS;
278}
279
280static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
281{
282 return nla_total_size(4) /* dst */
283 + nla_total_size(4) /* src */
284 + nla_total_size(4); /* flow */
285}
286
287static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
288{
289 rt_cache_flush(ops->fro_net);
290}
291
292static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = {
293 .family = AF_INET,
294 .rule_size = sizeof(struct fib4_rule),
295 .addr_size = sizeof(u32),
296 .action = fib4_rule_action,
297 .suppress = fib4_rule_suppress,
298 .match = fib4_rule_match,
299 .configure = fib4_rule_configure,
300 .delete = fib4_rule_delete,
301 .compare = fib4_rule_compare,
302 .fill = fib4_rule_fill,
303 .default_pref = fib_default_rule_pref,
304 .nlmsg_payload = fib4_rule_nlmsg_payload,
305 .flush_cache = fib4_rule_flush_cache,
306 .nlgroup = RTNLGRP_IPV4_RULE,
307 .policy = fib4_rule_policy,
308 .owner = THIS_MODULE,
309};
310
311static int fib_default_rules_init(struct fib_rules_ops *ops)
312{
313 int err;
314
315 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0);
316 if (err < 0)
317 return err;
318 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
319 if (err < 0)
320 return err;
321 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
322 if (err < 0)
323 return err;
324 return 0;
325}
326
327int __net_init fib4_rules_init(struct net *net)
328{
329 int err;
330 struct fib_rules_ops *ops;
331
332 ops = fib_rules_register(&fib4_rules_ops_template, net);
333 if (IS_ERR(ops))
334 return PTR_ERR(ops);
335
336 err = fib_default_rules_init(ops);
337 if (err < 0)
338 goto fail;
339 net->ipv4.rules_ops = ops;
340 net->ipv4.fib_has_custom_rules = false;
341 return 0;
342
343fail:
344 /* also cleans all rules already added */
345 fib_rules_unregister(ops);
346 return err;
347}
348
349void __net_exit fib4_rules_exit(struct net *net)
350{
351 fib_rules_unregister(net->ipv4.rules_ops);
352}
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 <linux/export.h>
30#include <net/ip.h>
31#include <net/route.h>
32#include <net/tcp.h>
33#include <net/ip_fib.h>
34#include <net/fib_rules.h>
35
36struct fib4_rule {
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_IP_ROUTE_CLASSID
46 u32 tclassid;
47#endif
48};
49
50#ifdef CONFIG_IP_ROUTE_CLASSID
51u32 fib_rules_tclass(const struct fib_result *res)
52{
53 return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;
54}
55#endif
56
57int fib_lookup(struct net *net, struct flowi4 *flp, struct fib_result *res)
58{
59 struct fib_lookup_arg arg = {
60 .result = res,
61 .flags = FIB_LOOKUP_NOREF,
62 };
63 int err;
64
65 err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg);
66 res->r = arg.rule;
67
68 return err;
69}
70EXPORT_SYMBOL_GPL(fib_lookup);
71
72static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
73 int flags, struct fib_lookup_arg *arg)
74{
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;
94 }
95
96 tbl = fib_get_table(rule->fr_net, rule->table);
97 if (!tbl)
98 goto errout;
99
100 err = fib_table_lookup(tbl, &flp->u.ip4, (struct fib_result *) arg->result, arg->flags);
101 if (err > 0)
102 err = -EAGAIN;
103errout:
104 return err;
105}
106
107
108static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
109{
110 struct fib4_rule *r = (struct fib4_rule *) rule;
111 struct flowi4 *fl4 = &fl->u.ip4;
112 __be32 daddr = fl4->daddr;
113 __be32 saddr = fl4->saddr;
114
115 if (((saddr ^ r->src) & r->srcmask) ||
116 ((daddr ^ r->dst) & r->dstmask))
117 return 0;
118
119 if (r->tos && (r->tos != fl4->flowi4_tos))
120 return 0;
121
122 return 1;
123}
124
125static struct fib_table *fib_empty_table(struct net *net)
126{
127 u32 id;
128
129 for (id = 1; id <= RT_TABLE_MAX; id++)
130 if (fib_get_table(net, id) == NULL)
131 return fib_new_table(net, id);
132 return NULL;
133}
134
135static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
136 FRA_GENERIC_POLICY,
137 [FRA_FLOW] = { .type = NLA_U32 },
138};
139
140static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
141 struct fib_rule_hdr *frh,
142 struct nlattr **tb)
143{
144 struct net *net = sock_net(skb->sk);
145 int err = -EINVAL;
146 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
147
148 if (frh->tos & ~IPTOS_TOS_MASK)
149 goto errout;
150
151 if (rule->table == RT_TABLE_UNSPEC) {
152 if (rule->action == FR_ACT_TO_TBL) {
153 struct fib_table *table;
154
155 table = fib_empty_table(net);
156 if (table == NULL) {
157 err = -ENOBUFS;
158 goto errout;
159 }
160
161 rule->table = table->tb_id;
162 }
163 }
164
165 if (frh->src_len)
166 rule4->src = nla_get_be32(tb[FRA_SRC]);
167
168 if (frh->dst_len)
169 rule4->dst = nla_get_be32(tb[FRA_DST]);
170
171#ifdef CONFIG_IP_ROUTE_CLASSID
172 if (tb[FRA_FLOW])
173 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
174#endif
175
176 rule4->src_len = frh->src_len;
177 rule4->srcmask = inet_make_mask(rule4->src_len);
178 rule4->dst_len = frh->dst_len;
179 rule4->dstmask = inet_make_mask(rule4->dst_len);
180 rule4->tos = frh->tos;
181
182 err = 0;
183errout:
184 return err;
185}
186
187static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
188 struct nlattr **tb)
189{
190 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
191
192 if (frh->src_len && (rule4->src_len != frh->src_len))
193 return 0;
194
195 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
196 return 0;
197
198 if (frh->tos && (rule4->tos != frh->tos))
199 return 0;
200
201#ifdef CONFIG_IP_ROUTE_CLASSID
202 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
203 return 0;
204#endif
205
206 if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC])))
207 return 0;
208
209 if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST])))
210 return 0;
211
212 return 1;
213}
214
215static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
216 struct fib_rule_hdr *frh)
217{
218 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
219
220 frh->dst_len = rule4->dst_len;
221 frh->src_len = rule4->src_len;
222 frh->tos = rule4->tos;
223
224 if ((rule4->dst_len &&
225 nla_put_be32(skb, FRA_DST, rule4->dst)) ||
226 (rule4->src_len &&
227 nla_put_be32(skb, FRA_SRC, rule4->src)))
228 goto nla_put_failure;
229#ifdef CONFIG_IP_ROUTE_CLASSID
230 if (rule4->tclassid &&
231 nla_put_u32(skb, FRA_FLOW, rule4->tclassid))
232 goto nla_put_failure;
233#endif
234 return 0;
235
236nla_put_failure:
237 return -ENOBUFS;
238}
239
240static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
241{
242 return nla_total_size(4) /* dst */
243 + nla_total_size(4) /* src */
244 + nla_total_size(4); /* flow */
245}
246
247static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
248{
249 rt_cache_flush(ops->fro_net, -1);
250}
251
252static const struct fib_rules_ops __net_initdata fib4_rules_ops_template = {
253 .family = AF_INET,
254 .rule_size = sizeof(struct fib4_rule),
255 .addr_size = sizeof(u32),
256 .action = fib4_rule_action,
257 .match = fib4_rule_match,
258 .configure = fib4_rule_configure,
259 .compare = fib4_rule_compare,
260 .fill = fib4_rule_fill,
261 .default_pref = fib_default_rule_pref,
262 .nlmsg_payload = fib4_rule_nlmsg_payload,
263 .flush_cache = fib4_rule_flush_cache,
264 .nlgroup = RTNLGRP_IPV4_RULE,
265 .policy = fib4_rule_policy,
266 .owner = THIS_MODULE,
267};
268
269static int fib_default_rules_init(struct fib_rules_ops *ops)
270{
271 int err;
272
273 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0);
274 if (err < 0)
275 return err;
276 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
277 if (err < 0)
278 return err;
279 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
280 if (err < 0)
281 return err;
282 return 0;
283}
284
285int __net_init fib4_rules_init(struct net *net)
286{
287 int err;
288 struct fib_rules_ops *ops;
289
290 ops = fib_rules_register(&fib4_rules_ops_template, net);
291 if (IS_ERR(ops))
292 return PTR_ERR(ops);
293
294 err = fib_default_rules_init(ops);
295 if (err < 0)
296 goto fail;
297 net->ipv4.rules_ops = ops;
298 return 0;
299
300fail:
301 /* also cleans all rules already added */
302 fib_rules_unregister(ops);
303 return err;
304}
305
306void __net_exit fib4_rules_exit(struct net *net)
307{
308 fib_rules_unregister(net->ipv4.rules_ops);
309}