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[NET] rules: Add support to invert selectors
[net-next-2.6.git] / net / core / fib_rules.c
CommitLineData
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1/*
2 * net/core/fib_rules.c Generic Routing Rules
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation, version 2.
7 *
8 * Authors: Thomas Graf <tgraf@suug.ch>
9 */
10
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11#include <linux/types.h>
12#include <linux/kernel.h>
13#include <linux/list.h>
14#include <net/fib_rules.h>
15
16static LIST_HEAD(rules_ops);
17static DEFINE_SPINLOCK(rules_mod_lock);
18
19static void notify_rule_change(int event, struct fib_rule *rule,
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20 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
21 u32 pid);
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22
23static struct fib_rules_ops *lookup_rules_ops(int family)
24{
25 struct fib_rules_ops *ops;
26
27 rcu_read_lock();
28 list_for_each_entry_rcu(ops, &rules_ops, list) {
29 if (ops->family == family) {
30 if (!try_module_get(ops->owner))
31 ops = NULL;
32 rcu_read_unlock();
33 return ops;
34 }
35 }
36 rcu_read_unlock();
37
38 return NULL;
39}
40
41static void rules_ops_put(struct fib_rules_ops *ops)
42{
43 if (ops)
44 module_put(ops->owner);
45}
46
47int fib_rules_register(struct fib_rules_ops *ops)
48{
49 int err = -EEXIST;
50 struct fib_rules_ops *o;
51
52 if (ops->rule_size < sizeof(struct fib_rule))
53 return -EINVAL;
54
55 if (ops->match == NULL || ops->configure == NULL ||
56 ops->compare == NULL || ops->fill == NULL ||
57 ops->action == NULL)
58 return -EINVAL;
59
60 spin_lock(&rules_mod_lock);
61 list_for_each_entry(o, &rules_ops, list)
62 if (ops->family == o->family)
63 goto errout;
64
65 list_add_tail_rcu(&ops->list, &rules_ops);
66 err = 0;
67errout:
68 spin_unlock(&rules_mod_lock);
69
70 return err;
71}
72
73EXPORT_SYMBOL_GPL(fib_rules_register);
74
75static void cleanup_ops(struct fib_rules_ops *ops)
76{
77 struct fib_rule *rule, *tmp;
78
79 list_for_each_entry_safe(rule, tmp, ops->rules_list, list) {
80 list_del_rcu(&rule->list);
81 fib_rule_put(rule);
82 }
83}
84
85int fib_rules_unregister(struct fib_rules_ops *ops)
86{
87 int err = 0;
88 struct fib_rules_ops *o;
89
90 spin_lock(&rules_mod_lock);
91 list_for_each_entry(o, &rules_ops, list) {
92 if (o == ops) {
93 list_del_rcu(&o->list);
94 cleanup_ops(ops);
95 goto out;
96 }
97 }
98
99 err = -ENOENT;
100out:
101 spin_unlock(&rules_mod_lock);
102
103 synchronize_rcu();
104
105 return err;
106}
107
108EXPORT_SYMBOL_GPL(fib_rules_unregister);
109
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110static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
111 struct flowi *fl, int flags)
112{
113 int ret = 0;
114
115 if (rule->ifindex && (rule->ifindex != fl->iif))
116 goto out;
117
118 if ((rule->mark ^ fl->mark) & rule->mark_mask)
119 goto out;
120
121 ret = ops->match(rule, fl, flags);
122out:
123 return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
124}
125
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126int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
127 int flags, struct fib_lookup_arg *arg)
128{
129 struct fib_rule *rule;
130 int err;
131
132 rcu_read_lock();
133
134 list_for_each_entry_rcu(rule, ops->rules_list, list) {
3dfbcc41 135 if (!fib_rule_match(rule, ops, fl, flags))
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136 continue;
137
138 err = ops->action(rule, fl, flags, arg);
139 if (err != -EAGAIN) {
140 fib_rule_get(rule);
141 arg->rule = rule;
142 goto out;
143 }
144 }
145
146 err = -ENETUNREACH;
147out:
148 rcu_read_unlock();
149
150 return err;
151}
152
153EXPORT_SYMBOL_GPL(fib_rules_lookup);
154
155int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
156{
157 struct fib_rule_hdr *frh = nlmsg_data(nlh);
158 struct fib_rules_ops *ops = NULL;
159 struct fib_rule *rule, *r, *last = NULL;
160 struct nlattr *tb[FRA_MAX+1];
161 int err = -EINVAL;
162
163 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
164 goto errout;
165
166 ops = lookup_rules_ops(frh->family);
167 if (ops == NULL) {
168 err = EAFNOSUPPORT;
169 goto errout;
170 }
171
172 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
173 if (err < 0)
174 goto errout;
175
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176 rule = kzalloc(ops->rule_size, GFP_KERNEL);
177 if (rule == NULL) {
178 err = -ENOMEM;
179 goto errout;
180 }
181
182 if (tb[FRA_PRIORITY])
183 rule->pref = nla_get_u32(tb[FRA_PRIORITY]);
184
185 if (tb[FRA_IFNAME]) {
186 struct net_device *dev;
187
188 rule->ifindex = -1;
5176f91e 189 nla_strlcpy(rule->ifname, tb[FRA_IFNAME], IFNAMSIZ);
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190 dev = __dev_get_by_name(rule->ifname);
191 if (dev)
192 rule->ifindex = dev->ifindex;
193 }
194
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195 if (tb[FRA_FWMARK]) {
196 rule->mark = nla_get_u32(tb[FRA_FWMARK]);
197 if (rule->mark)
198 /* compatibility: if the mark value is non-zero all bits
199 * are compared unless a mask is explicitly specified.
200 */
201 rule->mark_mask = 0xFFFFFFFF;
202 }
203
204 if (tb[FRA_FWMASK])
205 rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
206
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207 rule->action = frh->action;
208 rule->flags = frh->flags;
9e762a4a 209 rule->table = frh_get_table(frh, tb);
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210
211 if (!rule->pref && ops->default_pref)
212 rule->pref = ops->default_pref();
213
214 err = ops->configure(rule, skb, nlh, frh, tb);
215 if (err < 0)
216 goto errout_free;
217
218 list_for_each_entry(r, ops->rules_list, list) {
219 if (r->pref > rule->pref)
220 break;
221 last = r;
222 }
223
224 fib_rule_get(rule);
225
226 if (last)
227 list_add_rcu(&rule->list, &last->list);
228 else
229 list_add_rcu(&rule->list, ops->rules_list);
230
c17084d2 231 notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).pid);
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232 rules_ops_put(ops);
233 return 0;
234
235errout_free:
236 kfree(rule);
237errout:
238 rules_ops_put(ops);
239 return err;
240}
241
242int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
243{
244 struct fib_rule_hdr *frh = nlmsg_data(nlh);
245 struct fib_rules_ops *ops = NULL;
246 struct fib_rule *rule;
247 struct nlattr *tb[FRA_MAX+1];
248 int err = -EINVAL;
249
250 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
251 goto errout;
252
253 ops = lookup_rules_ops(frh->family);
254 if (ops == NULL) {
255 err = EAFNOSUPPORT;
256 goto errout;
257 }
258
259 err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
260 if (err < 0)
261 goto errout;
262
263 list_for_each_entry(rule, ops->rules_list, list) {
264 if (frh->action && (frh->action != rule->action))
265 continue;
266
9e762a4a 267 if (frh->table && (frh_get_table(frh, tb) != rule->table))
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268 continue;
269
270 if (tb[FRA_PRIORITY] &&
271 (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
272 continue;
273
274 if (tb[FRA_IFNAME] &&
275 nla_strcmp(tb[FRA_IFNAME], rule->ifname))
276 continue;
277
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278 if (tb[FRA_FWMARK] &&
279 (rule->mark != nla_get_u32(tb[FRA_FWMARK])))
280 continue;
281
282 if (tb[FRA_FWMASK] &&
283 (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK])))
284 continue;
285
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286 if (!ops->compare(rule, frh, tb))
287 continue;
288
289 if (rule->flags & FIB_RULE_PERMANENT) {
290 err = -EPERM;
291 goto errout;
292 }
293
294 list_del_rcu(&rule->list);
295 synchronize_rcu();
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296 notify_rule_change(RTM_DELRULE, rule, ops, nlh,
297 NETLINK_CB(skb).pid);
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298 fib_rule_put(rule);
299 rules_ops_put(ops);
300 return 0;
301 }
302
303 err = -ENOENT;
304errout:
305 rules_ops_put(ops);
306 return err;
307}
308
309static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
310 u32 pid, u32 seq, int type, int flags,
311 struct fib_rules_ops *ops)
312{
313 struct nlmsghdr *nlh;
314 struct fib_rule_hdr *frh;
315
316 nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
317 if (nlh == NULL)
318 return -1;
319
320 frh = nlmsg_data(nlh);
321 frh->table = rule->table;
9e762a4a 322 NLA_PUT_U32(skb, FRA_TABLE, rule->table);
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323 frh->res1 = 0;
324 frh->res2 = 0;
325 frh->action = rule->action;
326 frh->flags = rule->flags;
327
328 if (rule->ifname[0])
329 NLA_PUT_STRING(skb, FRA_IFNAME, rule->ifname);
330
331 if (rule->pref)
332 NLA_PUT_U32(skb, FRA_PRIORITY, rule->pref);
333
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334 if (rule->mark)
335 NLA_PUT_U32(skb, FRA_FWMARK, rule->mark);
336
337 if (rule->mark_mask || rule->mark)
338 NLA_PUT_U32(skb, FRA_FWMASK, rule->mark_mask);
339
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340 if (ops->fill(rule, skb, nlh, frh) < 0)
341 goto nla_put_failure;
342
343 return nlmsg_end(skb, nlh);
344
345nla_put_failure:
346 return nlmsg_cancel(skb, nlh);
347}
348
349int fib_rules_dump(struct sk_buff *skb, struct netlink_callback *cb, int family)
350{
351 int idx = 0;
352 struct fib_rule *rule;
353 struct fib_rules_ops *ops;
354
355 ops = lookup_rules_ops(family);
356 if (ops == NULL)
357 return -EAFNOSUPPORT;
358
359 rcu_read_lock();
360 list_for_each_entry(rule, ops->rules_list, list) {
361 if (idx < cb->args[0])
362 goto skip;
363
364 if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).pid,
365 cb->nlh->nlmsg_seq, RTM_NEWRULE,
366 NLM_F_MULTI, ops) < 0)
367 break;
368skip:
369 idx++;
370 }
371 rcu_read_unlock();
372 cb->args[0] = idx;
373 rules_ops_put(ops);
374
375 return skb->len;
376}
377
378EXPORT_SYMBOL_GPL(fib_rules_dump);
379
380static void notify_rule_change(int event, struct fib_rule *rule,
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381 struct fib_rules_ops *ops, struct nlmsghdr *nlh,
382 u32 pid)
14c0b97d 383{
c17084d2
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384 struct sk_buff *skb;
385 int err = -ENOBUFS;
14c0b97d 386
c17084d2 387 skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
14c0b97d 388 if (skb == NULL)
c17084d2
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389 goto errout;
390
391 err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
392 if (err < 0) {
14c0b97d 393 kfree_skb(skb);
c17084d2
TG
394 goto errout;
395 }
396
397 err = rtnl_notify(skb, pid, ops->nlgroup, nlh, GFP_KERNEL);
398errout:
399 if (err < 0)
400 rtnl_set_sk_err(ops->nlgroup, err);
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TG
401}
402
403static void attach_rules(struct list_head *rules, struct net_device *dev)
404{
405 struct fib_rule *rule;
406
407 list_for_each_entry(rule, rules, list) {
408 if (rule->ifindex == -1 &&
409 strcmp(dev->name, rule->ifname) == 0)
410 rule->ifindex = dev->ifindex;
411 }
412}
413
414static void detach_rules(struct list_head *rules, struct net_device *dev)
415{
416 struct fib_rule *rule;
417
418 list_for_each_entry(rule, rules, list)
419 if (rule->ifindex == dev->ifindex)
420 rule->ifindex = -1;
421}
422
423
424static int fib_rules_event(struct notifier_block *this, unsigned long event,
425 void *ptr)
426{
427 struct net_device *dev = ptr;
428 struct fib_rules_ops *ops;
429
430 ASSERT_RTNL();
431 rcu_read_lock();
432
433 switch (event) {
434 case NETDEV_REGISTER:
435 list_for_each_entry(ops, &rules_ops, list)
436 attach_rules(ops->rules_list, dev);
437 break;
438
439 case NETDEV_UNREGISTER:
440 list_for_each_entry(ops, &rules_ops, list)
441 detach_rules(ops->rules_list, dev);
442 break;
443 }
444
445 rcu_read_unlock();
446
447 return NOTIFY_DONE;
448}
449
450static struct notifier_block fib_rules_notifier = {
451 .notifier_call = fib_rules_event,
452};
453
454static int __init fib_rules_init(void)
455{
456 return register_netdevice_notifier(&fib_rules_notifier);
457}
458
459subsys_initcall(fib_rules_init);