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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/inet_dscp.h>
27#include <net/ip.h>
28#include <net/route.h>
29#include <net/tcp.h>
30#include <net/ip_fib.h>
31#include <net/nexthop.h>
32#include <net/fib_rules.h>
33#include <linux/indirect_call_wrapper.h>
34
35struct fib4_rule {
36 struct fib_rule common;
37 u8 dst_len;
38 u8 src_len;
39 dscp_t dscp;
40 u8 dscp_full:1; /* DSCP or TOS selector */
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
50static bool fib4_rule_matchall(const struct fib_rule *rule)
51{
52 struct fib4_rule *r = container_of(rule, struct fib4_rule, common);
53
54 if (r->dst_len || r->src_len || r->dscp)
55 return false;
56 return fib_rule_matchall(rule);
57}
58
59bool fib4_rule_default(const struct fib_rule *rule)
60{
61 if (!fib4_rule_matchall(rule) || rule->action != FR_ACT_TO_TBL ||
62 rule->l3mdev)
63 return false;
64 if (rule->table != RT_TABLE_LOCAL && rule->table != RT_TABLE_MAIN &&
65 rule->table != RT_TABLE_DEFAULT)
66 return false;
67 return true;
68}
69EXPORT_SYMBOL_GPL(fib4_rule_default);
70
71int fib4_rules_dump(struct net *net, struct notifier_block *nb,
72 struct netlink_ext_ack *extack)
73{
74 return fib_rules_dump(net, nb, AF_INET, extack);
75}
76
77unsigned int fib4_rules_seq_read(const struct net *net)
78{
79 return fib_rules_seq_read(net, AF_INET);
80}
81
82int __fib_lookup(struct net *net, struct flowi4 *flp,
83 struct fib_result *res, unsigned int flags)
84{
85 struct fib_lookup_arg arg = {
86 .result = res,
87 .flags = flags,
88 };
89 int err;
90
91 /* update flow if oif or iif point to device enslaved to l3mdev */
92 l3mdev_update_flow(net, flowi4_to_flowi(flp));
93
94 err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg);
95#ifdef CONFIG_IP_ROUTE_CLASSID
96 if (arg.rule)
97 res->tclassid = ((struct fib4_rule *)arg.rule)->tclassid;
98 else
99 res->tclassid = 0;
100#endif
101
102 if (err == -ESRCH)
103 err = -ENETUNREACH;
104
105 return err;
106}
107EXPORT_SYMBOL_GPL(__fib_lookup);
108
109INDIRECT_CALLABLE_SCOPE int fib4_rule_action(struct fib_rule *rule,
110 struct flowi *flp, int flags,
111 struct fib_lookup_arg *arg)
112{
113 int err = -EAGAIN;
114 struct fib_table *tbl;
115 u32 tb_id;
116
117 switch (rule->action) {
118 case FR_ACT_TO_TBL:
119 break;
120
121 case FR_ACT_UNREACHABLE:
122 return -ENETUNREACH;
123
124 case FR_ACT_PROHIBIT:
125 return -EACCES;
126
127 case FR_ACT_BLACKHOLE:
128 default:
129 return -EINVAL;
130 }
131
132 rcu_read_lock();
133
134 tb_id = fib_rule_get_table(rule, arg);
135 tbl = fib_get_table(rule->fr_net, tb_id);
136 if (tbl)
137 err = fib_table_lookup(tbl, &flp->u.ip4,
138 (struct fib_result *)arg->result,
139 arg->flags);
140
141 rcu_read_unlock();
142 return err;
143}
144
145INDIRECT_CALLABLE_SCOPE bool fib4_rule_suppress(struct fib_rule *rule,
146 int flags,
147 struct fib_lookup_arg *arg)
148{
149 struct fib_result *result = arg->result;
150 struct net_device *dev = NULL;
151
152 if (result->fi) {
153 struct fib_nh_common *nhc = fib_info_nhc(result->fi, 0);
154
155 dev = nhc->nhc_dev;
156 }
157
158 /* do not accept result if the route does
159 * not meet the required prefix length
160 */
161 if (result->prefixlen <= rule->suppress_prefixlen)
162 goto suppress_route;
163
164 /* do not accept result if the route uses a device
165 * belonging to a forbidden interface group
166 */
167 if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
168 goto suppress_route;
169
170 return false;
171
172suppress_route:
173 if (!(arg->flags & FIB_LOOKUP_NOREF))
174 fib_info_put(result->fi);
175 return true;
176}
177
178INDIRECT_CALLABLE_SCOPE int fib4_rule_match(struct fib_rule *rule,
179 struct flowi *fl, int flags)
180{
181 struct fib4_rule *r = (struct fib4_rule *) rule;
182 struct flowi4 *fl4 = &fl->u.ip4;
183 __be32 daddr = fl4->daddr;
184 __be32 saddr = fl4->saddr;
185
186 if (((saddr ^ r->src) & r->srcmask) ||
187 ((daddr ^ r->dst) & r->dstmask))
188 return 0;
189
190 /* When DSCP selector is used we need to match on the entire DSCP field
191 * in the flow information structure. When TOS selector is used we need
192 * to mask the upper three DSCP bits prior to matching to maintain
193 * legacy behavior.
194 */
195 if (r->dscp_full && r->dscp != inet_dsfield_to_dscp(fl4->flowi4_tos))
196 return 0;
197 else if (!r->dscp_full && r->dscp &&
198 !fib_dscp_masked_match(r->dscp, fl4))
199 return 0;
200
201 if (rule->ip_proto && (rule->ip_proto != fl4->flowi4_proto))
202 return 0;
203
204 if (fib_rule_port_range_set(&rule->sport_range) &&
205 !fib_rule_port_inrange(&rule->sport_range, fl4->fl4_sport))
206 return 0;
207
208 if (fib_rule_port_range_set(&rule->dport_range) &&
209 !fib_rule_port_inrange(&rule->dport_range, fl4->fl4_dport))
210 return 0;
211
212 return 1;
213}
214
215static struct fib_table *fib_empty_table(struct net *net)
216{
217 u32 id = 1;
218
219 while (1) {
220 if (!fib_get_table(net, id))
221 return fib_new_table(net, id);
222
223 if (id++ == RT_TABLE_MAX)
224 break;
225 }
226 return NULL;
227}
228
229static int fib4_nl2rule_dscp(const struct nlattr *nla, struct fib4_rule *rule4,
230 struct netlink_ext_ack *extack)
231{
232 if (rule4->dscp) {
233 NL_SET_ERR_MSG(extack, "Cannot specify both TOS and DSCP");
234 return -EINVAL;
235 }
236
237 rule4->dscp = inet_dsfield_to_dscp(nla_get_u8(nla) << 2);
238 rule4->dscp_full = true;
239
240 return 0;
241}
242
243static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
244 struct fib_rule_hdr *frh,
245 struct nlattr **tb,
246 struct netlink_ext_ack *extack)
247{
248 struct net *net = sock_net(skb->sk);
249 int err = -EINVAL;
250 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
251
252 if (!inet_validate_dscp(frh->tos)) {
253 NL_SET_ERR_MSG(extack,
254 "Invalid dsfield (tos): ECN bits must be 0");
255 goto errout;
256 }
257 /* IPv4 currently doesn't handle high order DSCP bits correctly */
258 if (frh->tos & ~IPTOS_TOS_MASK) {
259 NL_SET_ERR_MSG(extack, "Invalid tos");
260 goto errout;
261 }
262 rule4->dscp = inet_dsfield_to_dscp(frh->tos);
263
264 if (tb[FRA_DSCP] &&
265 fib4_nl2rule_dscp(tb[FRA_DSCP], rule4, extack) < 0)
266 goto errout;
267
268 /* split local/main if they are not already split */
269 err = fib_unmerge(net);
270 if (err)
271 goto errout;
272
273 if (rule->table == RT_TABLE_UNSPEC && !rule->l3mdev) {
274 if (rule->action == FR_ACT_TO_TBL) {
275 struct fib_table *table;
276
277 table = fib_empty_table(net);
278 if (!table) {
279 err = -ENOBUFS;
280 goto errout;
281 }
282
283 rule->table = table->tb_id;
284 }
285 }
286
287 if (frh->src_len)
288 rule4->src = nla_get_in_addr(tb[FRA_SRC]);
289
290 if (frh->dst_len)
291 rule4->dst = nla_get_in_addr(tb[FRA_DST]);
292
293#ifdef CONFIG_IP_ROUTE_CLASSID
294 if (tb[FRA_FLOW]) {
295 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
296 if (rule4->tclassid)
297 atomic_inc(&net->ipv4.fib_num_tclassid_users);
298 }
299#endif
300
301 if (fib_rule_requires_fldissect(rule))
302 net->ipv4.fib_rules_require_fldissect++;
303
304 rule4->src_len = frh->src_len;
305 rule4->srcmask = inet_make_mask(rule4->src_len);
306 rule4->dst_len = frh->dst_len;
307 rule4->dstmask = inet_make_mask(rule4->dst_len);
308
309 net->ipv4.fib_has_custom_rules = true;
310
311 err = 0;
312errout:
313 return err;
314}
315
316static int fib4_rule_delete(struct fib_rule *rule)
317{
318 struct net *net = rule->fr_net;
319 int err;
320
321 /* split local/main if they are not already split */
322 err = fib_unmerge(net);
323 if (err)
324 goto errout;
325
326#ifdef CONFIG_IP_ROUTE_CLASSID
327 if (((struct fib4_rule *)rule)->tclassid)
328 atomic_dec(&net->ipv4.fib_num_tclassid_users);
329#endif
330 net->ipv4.fib_has_custom_rules = true;
331
332 if (net->ipv4.fib_rules_require_fldissect &&
333 fib_rule_requires_fldissect(rule))
334 net->ipv4.fib_rules_require_fldissect--;
335errout:
336 return err;
337}
338
339static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
340 struct nlattr **tb)
341{
342 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
343
344 if (frh->src_len && (rule4->src_len != frh->src_len))
345 return 0;
346
347 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
348 return 0;
349
350 if (frh->tos &&
351 (rule4->dscp_full ||
352 inet_dscp_to_dsfield(rule4->dscp) != frh->tos))
353 return 0;
354
355 if (tb[FRA_DSCP]) {
356 dscp_t dscp;
357
358 dscp = inet_dsfield_to_dscp(nla_get_u8(tb[FRA_DSCP]) << 2);
359 if (!rule4->dscp_full || rule4->dscp != dscp)
360 return 0;
361 }
362
363#ifdef CONFIG_IP_ROUTE_CLASSID
364 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
365 return 0;
366#endif
367
368 if (frh->src_len && (rule4->src != nla_get_in_addr(tb[FRA_SRC])))
369 return 0;
370
371 if (frh->dst_len && (rule4->dst != nla_get_in_addr(tb[FRA_DST])))
372 return 0;
373
374 return 1;
375}
376
377static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
378 struct fib_rule_hdr *frh)
379{
380 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
381
382 frh->dst_len = rule4->dst_len;
383 frh->src_len = rule4->src_len;
384
385 if (rule4->dscp_full) {
386 frh->tos = 0;
387 if (nla_put_u8(skb, FRA_DSCP,
388 inet_dscp_to_dsfield(rule4->dscp) >> 2))
389 goto nla_put_failure;
390 } else {
391 frh->tos = inet_dscp_to_dsfield(rule4->dscp);
392 }
393
394 if ((rule4->dst_len &&
395 nla_put_in_addr(skb, FRA_DST, rule4->dst)) ||
396 (rule4->src_len &&
397 nla_put_in_addr(skb, FRA_SRC, rule4->src)))
398 goto nla_put_failure;
399#ifdef CONFIG_IP_ROUTE_CLASSID
400 if (rule4->tclassid &&
401 nla_put_u32(skb, FRA_FLOW, rule4->tclassid))
402 goto nla_put_failure;
403#endif
404 return 0;
405
406nla_put_failure:
407 return -ENOBUFS;
408}
409
410static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
411{
412 return nla_total_size(4) /* dst */
413 + nla_total_size(4) /* src */
414 + nla_total_size(4) /* flow */
415 + nla_total_size(1); /* dscp */
416}
417
418static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
419{
420 rt_cache_flush(ops->fro_net);
421}
422
423static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = {
424 .family = AF_INET,
425 .rule_size = sizeof(struct fib4_rule),
426 .addr_size = sizeof(u32),
427 .action = fib4_rule_action,
428 .suppress = fib4_rule_suppress,
429 .match = fib4_rule_match,
430 .configure = fib4_rule_configure,
431 .delete = fib4_rule_delete,
432 .compare = fib4_rule_compare,
433 .fill = fib4_rule_fill,
434 .nlmsg_payload = fib4_rule_nlmsg_payload,
435 .flush_cache = fib4_rule_flush_cache,
436 .nlgroup = RTNLGRP_IPV4_RULE,
437 .owner = THIS_MODULE,
438};
439
440static int fib_default_rules_init(struct fib_rules_ops *ops)
441{
442 int err;
443
444 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL);
445 if (err < 0)
446 return err;
447 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN);
448 if (err < 0)
449 return err;
450 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT);
451 if (err < 0)
452 return err;
453 return 0;
454}
455
456int __net_init fib4_rules_init(struct net *net)
457{
458 int err;
459 struct fib_rules_ops *ops;
460
461 ops = fib_rules_register(&fib4_rules_ops_template, net);
462 if (IS_ERR(ops))
463 return PTR_ERR(ops);
464
465 err = fib_default_rules_init(ops);
466 if (err < 0)
467 goto fail;
468 net->ipv4.rules_ops = ops;
469 net->ipv4.fib_has_custom_rules = false;
470 net->ipv4.fib_rules_require_fldissect = 0;
471 return 0;
472
473fail:
474 /* also cleans all rules already added */
475 fib_rules_unregister(ops);
476 return err;
477}
478
479void __net_exit fib4_rules_exit(struct net *net)
480{
481 fib_rules_unregister(net->ipv4.rules_ops);
482}
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,
51 struct fib_result *res, unsigned int flags)
52{
53 struct fib_lookup_arg arg = {
54 .result = res,
55 .flags = flags,
56 };
57 int err;
58
59 /* update flow if oif or iif point to device enslaved to l3mdev */
60 l3mdev_update_flow(net, flowi4_to_flowi(flp));
61
62 err = fib_rules_lookup(net->ipv4.rules_ops, flowi4_to_flowi(flp), 0, &arg);
63#ifdef CONFIG_IP_ROUTE_CLASSID
64 if (arg.rule)
65 res->tclassid = ((struct fib4_rule *)arg.rule)->tclassid;
66 else
67 res->tclassid = 0;
68#endif
69
70 if (err == -ESRCH)
71 err = -ENETUNREACH;
72
73 return err;
74}
75EXPORT_SYMBOL_GPL(__fib_lookup);
76
77static int fib4_rule_action(struct fib_rule *rule, struct flowi *flp,
78 int flags, struct fib_lookup_arg *arg)
79{
80 int err = -EAGAIN;
81 struct fib_table *tbl;
82 u32 tb_id;
83
84 switch (rule->action) {
85 case FR_ACT_TO_TBL:
86 break;
87
88 case FR_ACT_UNREACHABLE:
89 return -ENETUNREACH;
90
91 case FR_ACT_PROHIBIT:
92 return -EACCES;
93
94 case FR_ACT_BLACKHOLE:
95 default:
96 return -EINVAL;
97 }
98
99 rcu_read_lock();
100
101 tb_id = fib_rule_get_table(rule, arg);
102 tbl = fib_get_table(rule->fr_net, tb_id);
103 if (tbl)
104 err = fib_table_lookup(tbl, &flp->u.ip4,
105 (struct fib_result *)arg->result,
106 arg->flags);
107
108 rcu_read_unlock();
109 return err;
110}
111
112static bool fib4_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)
113{
114 struct fib_result *result = (struct fib_result *) arg->result;
115 struct net_device *dev = NULL;
116
117 if (result->fi)
118 dev = result->fi->fib_dev;
119
120 /* do not accept result if the route does
121 * not meet the required prefix length
122 */
123 if (result->prefixlen <= rule->suppress_prefixlen)
124 goto suppress_route;
125
126 /* do not accept result if the route uses a device
127 * belonging to a forbidden interface group
128 */
129 if (rule->suppress_ifgroup != -1 && dev && dev->group == rule->suppress_ifgroup)
130 goto suppress_route;
131
132 return false;
133
134suppress_route:
135 if (!(arg->flags & FIB_LOOKUP_NOREF))
136 fib_info_put(result->fi);
137 return true;
138}
139
140static int fib4_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
141{
142 struct fib4_rule *r = (struct fib4_rule *) rule;
143 struct flowi4 *fl4 = &fl->u.ip4;
144 __be32 daddr = fl4->daddr;
145 __be32 saddr = fl4->saddr;
146
147 if (((saddr ^ r->src) & r->srcmask) ||
148 ((daddr ^ r->dst) & r->dstmask))
149 return 0;
150
151 if (r->tos && (r->tos != fl4->flowi4_tos))
152 return 0;
153
154 return 1;
155}
156
157static struct fib_table *fib_empty_table(struct net *net)
158{
159 u32 id;
160
161 for (id = 1; id <= RT_TABLE_MAX; id++)
162 if (!fib_get_table(net, id))
163 return fib_new_table(net, id);
164 return NULL;
165}
166
167static int call_fib_rule_notifiers(struct net *net,
168 enum fib_event_type event_type)
169{
170 struct fib_notifier_info info;
171
172 return call_fib_notifiers(net, event_type, &info);
173}
174
175static const struct nla_policy fib4_rule_policy[FRA_MAX+1] = {
176 FRA_GENERIC_POLICY,
177 [FRA_FLOW] = { .type = NLA_U32 },
178};
179
180static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
181 struct fib_rule_hdr *frh,
182 struct nlattr **tb)
183{
184 struct net *net = sock_net(skb->sk);
185 int err = -EINVAL;
186 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
187
188 if (frh->tos & ~IPTOS_TOS_MASK)
189 goto errout;
190
191 /* split local/main if they are not already split */
192 err = fib_unmerge(net);
193 if (err)
194 goto errout;
195
196 if (rule->table == RT_TABLE_UNSPEC && !rule->l3mdev) {
197 if (rule->action == FR_ACT_TO_TBL) {
198 struct fib_table *table;
199
200 table = fib_empty_table(net);
201 if (!table) {
202 err = -ENOBUFS;
203 goto errout;
204 }
205
206 rule->table = table->tb_id;
207 }
208 }
209
210 if (frh->src_len)
211 rule4->src = nla_get_in_addr(tb[FRA_SRC]);
212
213 if (frh->dst_len)
214 rule4->dst = nla_get_in_addr(tb[FRA_DST]);
215
216#ifdef CONFIG_IP_ROUTE_CLASSID
217 if (tb[FRA_FLOW]) {
218 rule4->tclassid = nla_get_u32(tb[FRA_FLOW]);
219 if (rule4->tclassid)
220 net->ipv4.fib_num_tclassid_users++;
221 }
222#endif
223
224 rule4->src_len = frh->src_len;
225 rule4->srcmask = inet_make_mask(rule4->src_len);
226 rule4->dst_len = frh->dst_len;
227 rule4->dstmask = inet_make_mask(rule4->dst_len);
228 rule4->tos = frh->tos;
229
230 net->ipv4.fib_has_custom_rules = true;
231 call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD);
232
233 err = 0;
234errout:
235 return err;
236}
237
238static int fib4_rule_delete(struct fib_rule *rule)
239{
240 struct net *net = rule->fr_net;
241 int err;
242
243 /* split local/main if they are not already split */
244 err = fib_unmerge(net);
245 if (err)
246 goto errout;
247
248#ifdef CONFIG_IP_ROUTE_CLASSID
249 if (((struct fib4_rule *)rule)->tclassid)
250 net->ipv4.fib_num_tclassid_users--;
251#endif
252 net->ipv4.fib_has_custom_rules = true;
253 call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL);
254errout:
255 return err;
256}
257
258static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
259 struct nlattr **tb)
260{
261 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
262
263 if (frh->src_len && (rule4->src_len != frh->src_len))
264 return 0;
265
266 if (frh->dst_len && (rule4->dst_len != frh->dst_len))
267 return 0;
268
269 if (frh->tos && (rule4->tos != frh->tos))
270 return 0;
271
272#ifdef CONFIG_IP_ROUTE_CLASSID
273 if (tb[FRA_FLOW] && (rule4->tclassid != nla_get_u32(tb[FRA_FLOW])))
274 return 0;
275#endif
276
277 if (frh->src_len && (rule4->src != nla_get_in_addr(tb[FRA_SRC])))
278 return 0;
279
280 if (frh->dst_len && (rule4->dst != nla_get_in_addr(tb[FRA_DST])))
281 return 0;
282
283 return 1;
284}
285
286static int fib4_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
287 struct fib_rule_hdr *frh)
288{
289 struct fib4_rule *rule4 = (struct fib4_rule *) rule;
290
291 frh->dst_len = rule4->dst_len;
292 frh->src_len = rule4->src_len;
293 frh->tos = rule4->tos;
294
295 if ((rule4->dst_len &&
296 nla_put_in_addr(skb, FRA_DST, rule4->dst)) ||
297 (rule4->src_len &&
298 nla_put_in_addr(skb, FRA_SRC, rule4->src)))
299 goto nla_put_failure;
300#ifdef CONFIG_IP_ROUTE_CLASSID
301 if (rule4->tclassid &&
302 nla_put_u32(skb, FRA_FLOW, rule4->tclassid))
303 goto nla_put_failure;
304#endif
305 return 0;
306
307nla_put_failure:
308 return -ENOBUFS;
309}
310
311static size_t fib4_rule_nlmsg_payload(struct fib_rule *rule)
312{
313 return nla_total_size(4) /* dst */
314 + nla_total_size(4) /* src */
315 + nla_total_size(4); /* flow */
316}
317
318static void fib4_rule_flush_cache(struct fib_rules_ops *ops)
319{
320 rt_cache_flush(ops->fro_net);
321}
322
323static const struct fib_rules_ops __net_initconst fib4_rules_ops_template = {
324 .family = AF_INET,
325 .rule_size = sizeof(struct fib4_rule),
326 .addr_size = sizeof(u32),
327 .action = fib4_rule_action,
328 .suppress = fib4_rule_suppress,
329 .match = fib4_rule_match,
330 .configure = fib4_rule_configure,
331 .delete = fib4_rule_delete,
332 .compare = fib4_rule_compare,
333 .fill = fib4_rule_fill,
334 .nlmsg_payload = fib4_rule_nlmsg_payload,
335 .flush_cache = fib4_rule_flush_cache,
336 .nlgroup = RTNLGRP_IPV4_RULE,
337 .policy = fib4_rule_policy,
338 .owner = THIS_MODULE,
339};
340
341static int fib_default_rules_init(struct fib_rules_ops *ops)
342{
343 int err;
344
345 err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0);
346 if (err < 0)
347 return err;
348 err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
349 if (err < 0)
350 return err;
351 err = fib_default_rule_add(ops, 0x7FFF, RT_TABLE_DEFAULT, 0);
352 if (err < 0)
353 return err;
354 return 0;
355}
356
357int __net_init fib4_rules_init(struct net *net)
358{
359 int err;
360 struct fib_rules_ops *ops;
361
362 ops = fib_rules_register(&fib4_rules_ops_template, net);
363 if (IS_ERR(ops))
364 return PTR_ERR(ops);
365
366 err = fib_default_rules_init(ops);
367 if (err < 0)
368 goto fail;
369 net->ipv4.rules_ops = ops;
370 net->ipv4.fib_has_custom_rules = false;
371 return 0;
372
373fail:
374 /* also cleans all rules already added */
375 fib_rules_unregister(ops);
376 return err;
377}
378
379void __net_exit fib4_rules_exit(struct net *net)
380{
381 fib_rules_unregister(net->ipv4.rules_ops);
382}