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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 <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
35struct fib4_rule {
36 struct fib_rule common;
37 u8 dst_len;
38 u8 src_len;
39 u8 tos;
40 __be32 src;
41 __be32 srcmask;
42 __be32 dst;
43 __be32 dstmask;
44#ifdef CONFIG_IP_ROUTE_CLASSID
45 u32 tclassid;
46#endif
47};
48
49#ifdef CONFIG_IP_ROUTE_CLASSID
50u32 fib_rules_tclass(const struct fib_result *res)
51{
52 return res->r ? ((struct fib4_rule *) res->r)->tclassid : 0;
53}
54#endif
55
56int fib_lookup(struct net *net, struct flowi4 *flp, struct fib_result *res)
57{
58 struct fib_lookup_arg arg = {
59 .result = res,
60 .flags = FIB_LOOKUP_NOREF,
61 };
62 int err;
63
64 err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg);
65 res->r = arg.rule;
66
67 return err;
68}
69
70static 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 tbl = fib_get_table(rule->fr_net, rule->table);
95 if (!tbl)
96 goto errout;
97
98 err = fib_table_lookup(tbl, &flp->u.ip4, (struct fib_result *) arg->result, arg->flags);
99 if (err > 0)
100 err = -EAGAIN;
101errout:
102 return err;
103}
104
105
106static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
107{
108 struct fib4_rule *r = (struct fib4_rule *) rule;
109 struct flowi4 *fl4 = &fl->u.ip4;
110 __be32 daddr = fl4->daddr;
111 __be32 saddr = fl4->saddr;
112
113 if (((saddr ^ r->src) & r->srcmask) ||
114 ((daddr ^ r->dst) & r->dstmask))
115 return 0;
116
117 if (r->tos && (r->tos != fl4->flowi4_tos))
118 return 0;
119
120 return 1;
121}
122
123static struct fib_table *fib_empty_table(struct net *net)
124{
125 u32 id;
126
127 for (id = 1; id <= RT_TABLE_MAX; id++)
128 if (fib_get_table(net, id) == NULL)
129 return fib_new_table(net, id);
130 return NULL;
131}
132
133static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
134 FRA_GENERIC_POLICY,
135 [FRA_FLOW] = { .type = NLA_U32 },
136};
137
138static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
139 struct fib_rule_hdr *frh,
140 struct nlattr **tb)
141{
142 struct net *net = sock_net(skb->sk);
143 int err = -EINVAL;
144 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
145
146 if (frh->tos & ~IPTOS_TOS_MASK)
147 goto errout;
148
149 if (rule->table == RT_TABLE_UNSPEC) {
150 if (rule->action == FR_ACT_TO_TBL) {
151 struct fib_table *table;
152
153 table = fib_empty_table(net);
154 if (table == NULL) {
155 err = -ENOBUFS;
156 goto errout;
157 }
158
159 rule->table = table->tb_id;
160 }
161 }
162
163 if (frh->src_len)
164 rule4->src = nla_get_be32(tb[FRA_SRC]);
165
166 if (frh->dst_len)
167 rule4->dst = nla_get_be32(tb[FRA_DST]);
168
169#ifdef CONFIG_IP_ROUTE_CLASSID
170 if (tb[FRA_FLOW])
171 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
172#endif
173
174 rule4->src_len = frh->src_len;
175 rule4->srcmask = inet_make_mask(rule4->src_len);
176 rule4->dst_len = frh->dst_len;
177 rule4->dstmask = inet_make_mask(rule4->dst_len);
178 rule4->tos = frh->tos;
179
180 err = 0;
181errout:
182 return err;
183}
184
185static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
186 struct nlattr **tb)
187{
188 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
189
190 if (frh->src_len && (rule4->src_len != frh->src_len))
191 return 0;
192
193 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
194 return 0;
195
196 if (frh->tos && (rule4->tos != frh->tos))
197 return 0;
198
199#ifdef CONFIG_IP_ROUTE_CLASSID
200 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
201 return 0;
202#endif
203
204 if (frh->src_len && (rule4->src != nla_get_be32(tb[FRA_SRC])))
205 return 0;
206
207 if (frh->dst_len && (rule4->dst != nla_get_be32(tb[FRA_DST])))
208 return 0;
209
210 return 1;
211}
212
213static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
214 struct fib_rule_hdr *frh)
215{
216 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
217
218 frh->dst_len = rule4->dst_len;
219 frh->src_len = rule4->src_len;
220 frh->tos = rule4->tos;
221
222 if (rule4->dst_len)
223 NLA_PUT_BE32(skb, FRA_DST, rule4->dst);
224
225 if (rule4->src_len)
226 NLA_PUT_BE32(skb, FRA_SRC, rule4->src);
227
228#ifdef CONFIG_IP_ROUTE_CLASSID
229 if (rule4->tclassid)
230 NLA_PUT_U32(skb, FRA_FLOW, rule4->tclassid);
231#endif
232 return 0;
233
234nla_put_failure:
235 return -ENOBUFS;
236}
237
238static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
239{
240 return nla_total_size(4) /* dst */
241 + nla_total_size(4) /* src */
242 + nla_total_size(4); /* flow */
243}
244
245static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
246{
247 rt_cache_flush(ops->fro_net, -1);
248}
249
250static const struct fib_rules_ops __net_initdata fib4_rules_ops_template = {
251 .family = AF_INET,
252 .rule_size = sizeof(struct fib4_rule),
253 .addr_size = sizeof(u32),
254 .action = fib4_rule_action,
255 .match = fib4_rule_match,
256 .configure = fib4_rule_configure,
257 .compare = fib4_rule_compare,
258 .fill = fib4_rule_fill,
259 .default_pref = fib_default_rule_pref,
260 .nlmsg_payload = fib4_rule_nlmsg_payload,
261 .flush_cache = fib4_rule_flush_cache,
262 .nlgroup = RTNLGRP_IPV4_RULE,
263 .policy = fib4_rule_policy,
264 .owner = THIS_MODULE,
265};
266
267static int fib_default_rules_init(struct fib_rules_ops *ops)
268{
269 int err;
270
271 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0);
272 if (err < 0)
273 return err;
274 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
275 if (err < 0)
276 return err;
277 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
278 if (err < 0)
279 return err;
280 return 0;
281}
282
283int __net_init fib4_rules_init(struct net *net)
284{
285 int err;
286 struct fib_rules_ops *ops;
287
288 ops = fib_rules_register(&fib4_rules_ops_template, net);
289 if (IS_ERR(ops))
290 return PTR_ERR(ops);
291
292 err = fib_default_rules_init(ops);
293 if (err < 0)
294 goto fail;
295 net->ipv4.rules_ops = ops;
296 return 0;
297
298fail:
299 /* also cleans all rules already added */
300 fib_rules_unregister(ops);
301 return err;
302}
303
304void __net_exit fib4_rules_exit(struct net *net)
305{
306 fib_rules_unregister(net->ipv4.rules_ops);
307}