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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * IPv4 Forwarding Information Base: policy rules.
8 *
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 * Thomas Graf <tgraf@suug.ch>
11 *
12 * Fixes:
13 * Rani Assaf : local_rule cannot be deleted
14 * Marc Boucher : routing by fwmark
15 */
16
17#include <linux/types.h>
18#include <linux/kernel.h>
19#include <linux/netdevice.h>
20#include <linux/netlink.h>
21#include <linux/inetdevice.h>
22#include <linux/init.h>
23#include <linux/list.h>
24#include <linux/rcupdate.h>
25#include <linux/export.h>
26#include <net/ip.h>
27#include <net/route.h>
28#include <net/tcp.h>
29#include <net/ip_fib.h>
30#include <net/nexthop.h>
31#include <net/fib_rules.h>
32#include <linux/indirect_call_wrapper.h>
33
34struct fib4_rule {
35 struct fib_rule common;
36 u8 dst_len;
37 u8 src_len;
38 u8 tos;
39 __be32 src;
40 __be32 srcmask;
41 __be32 dst;
42 __be32 dstmask;
43#ifdef CONFIG_IP_ROUTE_CLASSID
44 u32 tclassid;
45#endif
46};
47
48static bool fib4_rule_matchall(const struct fib_rule *rule)
49{
50 struct fib4_rule *r = container_of(rule, struct fib4_rule, common);
51
52 if (r->dst_len || r->src_len || r->tos)
53 return false;
54 return fib_rule_matchall(rule);
55}
56
57bool fib4_rule_default(const struct fib_rule *rule)
58{
59 if (!fib4_rule_matchall(rule) || rule->action != FR_ACT_TO_TBL ||
60 rule->l3mdev)
61 return false;
62 if (rule->table != RT_TABLE_LOCAL && rule->table != RT_TABLE_MAIN &&
63 rule->table != RT_TABLE_DEFAULT)
64 return false;
65 return true;
66}
67EXPORT_SYMBOL_GPL(fib4_rule_default);
68
69int fib4_rules_dump(struct net *net, struct notifier_block *nb,
70 struct netlink_ext_ack *extack)
71{
72 return fib_rules_dump(net, nb, AF_INET, extack);
73}
74
75unsigned int fib4_rules_seq_read(struct net *net)
76{
77 return fib_rules_seq_read(net, AF_INET);
78}
79
80int __fib_lookup(struct net *net, struct flowi4 *flp,
81 struct fib_result *res, unsigned int flags)
82{
83 struct fib_lookup_arg arg = {
84 .result = res,
85 .flags = flags,
86 };
87 int err;
88
89 /* update flow if oif or iif point to device enslaved to l3mdev */
90 l3mdev_update_flow(net, flowi4_to_flowi(flp));
91
92 err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg);
93#ifdef CONFIG_IP_ROUTE_CLASSID
94 if (arg.rule)
95 res->tclassid = ((struct fib4_rule *)arg.rule)->tclassid;
96 else
97 res->tclassid = 0;
98#endif
99
100 if (err == -ESRCH)
101 err = -ENETUNREACH;
102
103 return err;
104}
105EXPORT_SYMBOL_GPL(__fib_lookup);
106
107INDIRECT_CALLABLE_SCOPE int fib4_rule_action(struct fib_rule *rule,
108 struct flowi *flp, int flags,
109 struct fib_lookup_arg *arg)
110{
111 int err = -EAGAIN;
112 struct fib_table *tbl;
113 u32 tb_id;
114
115 switch (rule->action) {
116 case FR_ACT_TO_TBL:
117 break;
118
119 case FR_ACT_UNREACHABLE:
120 return -ENETUNREACH;
121
122 case FR_ACT_PROHIBIT:
123 return -EACCES;
124
125 case FR_ACT_BLACKHOLE:
126 default:
127 return -EINVAL;
128 }
129
130 rcu_read_lock();
131
132 tb_id = fib_rule_get_table(rule, arg);
133 tbl = fib_get_table(rule->fr_net, tb_id);
134 if (tbl)
135 err = fib_table_lookup(tbl, &flp->u.ip4,
136 (struct fib_result *)arg->result,
137 arg->flags);
138
139 rcu_read_unlock();
140 return err;
141}
142
143INDIRECT_CALLABLE_SCOPE bool fib4_rule_suppress(struct fib_rule *rule,
144 struct fib_lookup_arg *arg)
145{
146 struct fib_result *result = (struct fib_result *) arg->result;
147 struct net_device *dev = NULL;
148
149 if (result->fi) {
150 struct fib_nh_common *nhc = fib_info_nhc(result->fi, 0);
151
152 dev = nhc->nhc_dev;
153 }
154
155 /* do not accept result if the route does
156 * not meet the required prefix length
157 */
158 if (result->prefixlen <= rule->suppress_prefixlen)
159 goto suppress_route;
160
161 /* do not accept result if the route uses a device
162 * belonging to a forbidden interface group
163 */
164 if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
165 goto suppress_route;
166
167 return false;
168
169suppress_route:
170 if (!(arg->flags & FIB_LOOKUP_NOREF))
171 fib_info_put(result->fi);
172 return true;
173}
174
175INDIRECT_CALLABLE_SCOPE int fib4_rule_match(struct fib_rule *rule,
176 struct flowi *fl, int flags)
177{
178 struct fib4_rule *r = (struct fib4_rule *) rule;
179 struct flowi4 *fl4 = &fl->u.ip4;
180 __be32 daddr = fl4->daddr;
181 __be32 saddr = fl4->saddr;
182
183 if (((saddr ^ r->src) & r->srcmask) ||
184 ((daddr ^ r->dst) & r->dstmask))
185 return 0;
186
187 if (r->tos && (r->tos != fl4->flowi4_tos))
188 return 0;
189
190 if (rule->ip_proto && (rule->ip_proto != fl4->flowi4_proto))
191 return 0;
192
193 if (fib_rule_port_range_set(&rule->sport_range) &&
194 !fib_rule_port_inrange(&rule->sport_range, fl4->fl4_sport))
195 return 0;
196
197 if (fib_rule_port_range_set(&rule->dport_range) &&
198 !fib_rule_port_inrange(&rule->dport_range, fl4->fl4_dport))
199 return 0;
200
201 return 1;
202}
203
204static struct fib_table *fib_empty_table(struct net *net)
205{
206 u32 id = 1;
207
208 while (1) {
209 if (!fib_get_table(net, id))
210 return fib_new_table(net, id);
211
212 if (id++ == RT_TABLE_MAX)
213 break;
214 }
215 return NULL;
216}
217
218static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
219 FRA_GENERIC_POLICY,
220 [FRA_FLOW] = { .type = NLA_U32 },
221};
222
223static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
224 struct fib_rule_hdr *frh,
225 struct nlattr **tb,
226 struct netlink_ext_ack *extack)
227{
228 struct net *net = sock_net(skb->sk);
229 int err = -EINVAL;
230 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
231
232 if (frh->tos & ~IPTOS_TOS_MASK) {
233 NL_SET_ERR_MSG(extack, "Invalid tos");
234 goto errout;
235 }
236
237 /* split local/main if they are not already split */
238 err = fib_unmerge(net);
239 if (err)
240 goto errout;
241
242 if (rule->table == RT_TABLE_UNSPEC && !rule->l3mdev) {
243 if (rule->action == FR_ACT_TO_TBL) {
244 struct fib_table *table;
245
246 table = fib_empty_table(net);
247 if (!table) {
248 err = -ENOBUFS;
249 goto errout;
250 }
251
252 rule->table = table->tb_id;
253 }
254 }
255
256 if (frh->src_len)
257 rule4->src = nla_get_in_addr(tb[FRA_SRC]);
258
259 if (frh->dst_len)
260 rule4->dst = nla_get_in_addr(tb[FRA_DST]);
261
262#ifdef CONFIG_IP_ROUTE_CLASSID
263 if (tb[FRA_FLOW]) {
264 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
265 if (rule4->tclassid)
266 net->ipv4.fib_num_tclassid_users++;
267 }
268#endif
269
270 if (fib_rule_requires_fldissect(rule))
271 net->ipv4.fib_rules_require_fldissect++;
272
273 rule4->src_len = frh->src_len;
274 rule4->srcmask = inet_make_mask(rule4->src_len);
275 rule4->dst_len = frh->dst_len;
276 rule4->dstmask = inet_make_mask(rule4->dst_len);
277 rule4->tos = frh->tos;
278
279 net->ipv4.fib_has_custom_rules = true;
280
281 err = 0;
282errout:
283 return err;
284}
285
286static int fib4_rule_delete(struct fib_rule *rule)
287{
288 struct net *net = rule->fr_net;
289 int err;
290
291 /* split local/main if they are not already split */
292 err = fib_unmerge(net);
293 if (err)
294 goto errout;
295
296#ifdef CONFIG_IP_ROUTE_CLASSID
297 if (((struct fib4_rule *)rule)->tclassid)
298 net->ipv4.fib_num_tclassid_users--;
299#endif
300 net->ipv4.fib_has_custom_rules = true;
301
302 if (net->ipv4.fib_rules_require_fldissect &&
303 fib_rule_requires_fldissect(rule))
304 net->ipv4.fib_rules_require_fldissect--;
305errout:
306 return err;
307}
308
309static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
310 struct nlattr **tb)
311{
312 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
313
314 if (frh->src_len && (rule4->src_len != frh->src_len))
315 return 0;
316
317 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
318 return 0;
319
320 if (frh->tos && (rule4->tos != frh->tos))
321 return 0;
322
323#ifdef CONFIG_IP_ROUTE_CLASSID
324 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
325 return 0;
326#endif
327
328 if (frh->src_len && (rule4->src != nla_get_in_addr(tb[FRA_SRC])))
329 return 0;
330
331 if (frh->dst_len && (rule4->dst != nla_get_in_addr(tb[FRA_DST])))
332 return 0;
333
334 return 1;
335}
336
337static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
338 struct fib_rule_hdr *frh)
339{
340 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
341
342 frh->dst_len = rule4->dst_len;
343 frh->src_len = rule4->src_len;
344 frh->tos = rule4->tos;
345
346 if ((rule4->dst_len &&
347 nla_put_in_addr(skb, FRA_DST, rule4->dst)) ||
348 (rule4->src_len &&
349 nla_put_in_addr(skb, FRA_SRC, rule4->src)))
350 goto nla_put_failure;
351#ifdef CONFIG_IP_ROUTE_CLASSID
352 if (rule4->tclassid &&
353 nla_put_u32(skb, FRA_FLOW, rule4->tclassid))
354 goto nla_put_failure;
355#endif
356 return 0;
357
358nla_put_failure:
359 return -ENOBUFS;
360}
361
362static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
363{
364 return nla_total_size(4) /* dst */
365 + nla_total_size(4) /* src */
366 + nla_total_size(4); /* flow */
367}
368
369static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
370{
371 rt_cache_flush(ops->fro_net);
372}
373
374static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = {
375 .family = AF_INET,
376 .rule_size = sizeof(struct fib4_rule),
377 .addr_size = sizeof(u32),
378 .action = fib4_rule_action,
379 .suppress = fib4_rule_suppress,
380 .match = fib4_rule_match,
381 .configure = fib4_rule_configure,
382 .delete = fib4_rule_delete,
383 .compare = fib4_rule_compare,
384 .fill = fib4_rule_fill,
385 .nlmsg_payload = fib4_rule_nlmsg_payload,
386 .flush_cache = fib4_rule_flush_cache,
387 .nlgroup = RTNLGRP_IPV4_RULE,
388 .policy = fib4_rule_policy,
389 .owner = THIS_MODULE,
390};
391
392static int fib_default_rules_init(struct fib_rules_ops *ops)
393{
394 int err;
395
396 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0);
397 if (err < 0)
398 return err;
399 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
400 if (err < 0)
401 return err;
402 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
403 if (err < 0)
404 return err;
405 return 0;
406}
407
408int __net_init fib4_rules_init(struct net *net)
409{
410 int err;
411 struct fib_rules_ops *ops;
412
413 ops = fib_rules_register(&fib4_rules_ops_template, net);
414 if (IS_ERR(ops))
415 return PTR_ERR(ops);
416
417 err = fib_default_rules_init(ops);
418 if (err < 0)
419 goto fail;
420 net->ipv4.rules_ops = ops;
421 net->ipv4.fib_has_custom_rules = false;
422 net->ipv4.fib_rules_require_fldissect = 0;
423 return 0;
424
425fail:
426 /* also cleans all rules already added */
427 fib_rules_unregister(ops);
428 return err;
429}
430
431void __net_exit fib4_rules_exit(struct net *net)
432{
433 fib_rules_unregister(net->ipv4.rules_ops);
434}
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}