Linux Audio

Check our new training course

Loading...
v3.15
  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
 11#include <linux/types.h>
 12#include <linux/kernel.h>
 13#include <linux/slab.h>
 14#include <linux/list.h>
 15#include <linux/module.h>
 16#include <net/net_namespace.h>
 17#include <net/sock.h>
 18#include <net/fib_rules.h>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 19
 20int fib_default_rule_add(struct fib_rules_ops *ops,
 21			 u32 pref, u32 table, u32 flags)
 22{
 23	struct fib_rule *r;
 24
 25	r = kzalloc(ops->rule_size, GFP_KERNEL);
 26	if (r == NULL)
 27		return -ENOMEM;
 28
 29	atomic_set(&r->refcnt, 1);
 30	r->action = FR_ACT_TO_TBL;
 31	r->pref = pref;
 32	r->table = table;
 33	r->flags = flags;
 34	r->fr_net = hold_net(ops->fro_net);
 
 
 35
 36	r->suppress_prefixlen = -1;
 37	r->suppress_ifgroup = -1;
 38
 39	/* The lock is not required here, the list in unreacheable
 40	 * at the moment this function is called */
 41	list_add_tail(&r->list, &ops->rules_list);
 42	return 0;
 43}
 44EXPORT_SYMBOL(fib_default_rule_add);
 45
 46u32 fib_default_rule_pref(struct fib_rules_ops *ops)
 47{
 48	struct list_head *pos;
 49	struct fib_rule *rule;
 50
 51	if (!list_empty(&ops->rules_list)) {
 52		pos = ops->rules_list.next;
 53		if (pos->next != &ops->rules_list) {
 54			rule = list_entry(pos->next, struct fib_rule, list);
 55			if (rule->pref)
 56				return rule->pref - 1;
 57		}
 58	}
 59
 60	return 0;
 61}
 62EXPORT_SYMBOL(fib_default_rule_pref);
 63
 64static void notify_rule_change(int event, struct fib_rule *rule,
 65			       struct fib_rules_ops *ops, struct nlmsghdr *nlh,
 66			       u32 pid);
 67
 68static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family)
 69{
 70	struct fib_rules_ops *ops;
 71
 72	rcu_read_lock();
 73	list_for_each_entry_rcu(ops, &net->rules_ops, list) {
 74		if (ops->family == family) {
 75			if (!try_module_get(ops->owner))
 76				ops = NULL;
 77			rcu_read_unlock();
 78			return ops;
 79		}
 80	}
 81	rcu_read_unlock();
 82
 83	return NULL;
 84}
 85
 86static void rules_ops_put(struct fib_rules_ops *ops)
 87{
 88	if (ops)
 89		module_put(ops->owner);
 90}
 91
 92static void flush_route_cache(struct fib_rules_ops *ops)
 93{
 94	if (ops->flush_cache)
 95		ops->flush_cache(ops);
 96}
 97
 98static int __fib_rules_register(struct fib_rules_ops *ops)
 99{
100	int err = -EEXIST;
101	struct fib_rules_ops *o;
102	struct net *net;
103
104	net = ops->fro_net;
105
106	if (ops->rule_size < sizeof(struct fib_rule))
107		return -EINVAL;
108
109	if (ops->match == NULL || ops->configure == NULL ||
110	    ops->compare == NULL || ops->fill == NULL ||
111	    ops->action == NULL)
112		return -EINVAL;
113
114	spin_lock(&net->rules_mod_lock);
115	list_for_each_entry(o, &net->rules_ops, list)
116		if (ops->family == o->family)
117			goto errout;
118
119	hold_net(net);
120	list_add_tail_rcu(&ops->list, &net->rules_ops);
121	err = 0;
122errout:
123	spin_unlock(&net->rules_mod_lock);
124
125	return err;
126}
127
128struct fib_rules_ops *
129fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
130{
131	struct fib_rules_ops *ops;
132	int err;
133
134	ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
135	if (ops == NULL)
136		return ERR_PTR(-ENOMEM);
137
138	INIT_LIST_HEAD(&ops->rules_list);
139	ops->fro_net = net;
140
141	err = __fib_rules_register(ops);
142	if (err) {
143		kfree(ops);
144		ops = ERR_PTR(err);
145	}
146
147	return ops;
148}
149EXPORT_SYMBOL_GPL(fib_rules_register);
150
151static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
152{
153	struct fib_rule *rule, *tmp;
154
155	list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
156		list_del_rcu(&rule->list);
157		if (ops->delete)
158			ops->delete(rule);
159		fib_rule_put(rule);
160	}
161}
162
163static void fib_rules_put_rcu(struct rcu_head *head)
164{
165	struct fib_rules_ops *ops = container_of(head, struct fib_rules_ops, rcu);
166	struct net *net = ops->fro_net;
167
168	release_net(net);
169	kfree(ops);
170}
171
172void fib_rules_unregister(struct fib_rules_ops *ops)
173{
174	struct net *net = ops->fro_net;
175
176	spin_lock(&net->rules_mod_lock);
177	list_del_rcu(&ops->list);
178	fib_rules_cleanup_ops(ops);
179	spin_unlock(&net->rules_mod_lock);
180
181	call_rcu(&ops->rcu, fib_rules_put_rcu);
 
182}
183EXPORT_SYMBOL_GPL(fib_rules_unregister);
184
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
185static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
186			  struct flowi *fl, int flags)
 
187{
188	int ret = 0;
189
190	if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
191		goto out;
192
193	if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
194		goto out;
195
196	if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
197		goto out;
198
 
 
 
 
 
 
 
 
 
 
199	ret = ops->match(rule, fl, flags);
200out:
201	return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
202}
203
204int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
205		     int flags, struct fib_lookup_arg *arg)
206{
207	struct fib_rule *rule;
208	int err;
209
210	rcu_read_lock();
211
212	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
213jumped:
214		if (!fib_rule_match(rule, ops, fl, flags))
215			continue;
216
217		if (rule->action == FR_ACT_GOTO) {
218			struct fib_rule *target;
219
220			target = rcu_dereference(rule->ctarget);
221			if (target == NULL) {
222				continue;
223			} else {
224				rule = target;
225				goto jumped;
226			}
227		} else if (rule->action == FR_ACT_NOP)
228			continue;
229		else
230			err = ops->action(rule, fl, flags, arg);
231
232		if (!err && ops->suppress && ops->suppress(rule, arg))
233			continue;
234
235		if (err != -EAGAIN) {
236			if ((arg->flags & FIB_LOOKUP_NOREF) ||
237			    likely(atomic_inc_not_zero(&rule->refcnt))) {
238				arg->rule = rule;
239				goto out;
240			}
241			break;
242		}
243	}
244
245	err = -ESRCH;
246out:
247	rcu_read_unlock();
248
249	return err;
250}
251EXPORT_SYMBOL_GPL(fib_rules_lookup);
252
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
253static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb,
254			    struct fib_rules_ops *ops)
255{
256	int err = -EINVAL;
257
258	if (frh->src_len)
259		if (tb[FRA_SRC] == NULL ||
260		    frh->src_len > (ops->addr_size * 8) ||
261		    nla_len(tb[FRA_SRC]) != ops->addr_size)
262			goto errout;
263
264	if (frh->dst_len)
265		if (tb[FRA_DST] == NULL ||
266		    frh->dst_len > (ops->addr_size * 8) ||
267		    nla_len(tb[FRA_DST]) != ops->addr_size)
268			goto errout;
269
270	err = 0;
271errout:
272	return err;
273}
274
275static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
276{
277	struct net *net = sock_net(skb->sk);
278	struct fib_rule_hdr *frh = nlmsg_data(nlh);
279	struct fib_rules_ops *ops = NULL;
280	struct fib_rule *rule, *r, *last = NULL;
281	struct nlattr *tb[FRA_MAX+1];
282	int err = -EINVAL, unresolved = 0;
283
284	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
285		goto errout;
286
287	ops = lookup_rules_ops(net, frh->family);
288	if (ops == NULL) {
289		err = -EAFNOSUPPORT;
290		goto errout;
291	}
292
293	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
294	if (err < 0)
295		goto errout;
296
297	err = validate_rulemsg(frh, tb, ops);
298	if (err < 0)
299		goto errout;
300
301	rule = kzalloc(ops->rule_size, GFP_KERNEL);
302	if (rule == NULL) {
303		err = -ENOMEM;
304		goto errout;
305	}
306	rule->fr_net = hold_net(net);
 
 
 
 
307
308	if (tb[FRA_PRIORITY])
309		rule->pref = nla_get_u32(tb[FRA_PRIORITY]);
310
311	if (tb[FRA_IIFNAME]) {
312		struct net_device *dev;
313
314		rule->iifindex = -1;
315		nla_strlcpy(rule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
316		dev = __dev_get_by_name(net, rule->iifname);
317		if (dev)
318			rule->iifindex = dev->ifindex;
319	}
320
321	if (tb[FRA_OIFNAME]) {
322		struct net_device *dev;
323
324		rule->oifindex = -1;
325		nla_strlcpy(rule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
326		dev = __dev_get_by_name(net, rule->oifname);
327		if (dev)
328			rule->oifindex = dev->ifindex;
329	}
330
331	if (tb[FRA_FWMARK]) {
332		rule->mark = nla_get_u32(tb[FRA_FWMARK]);
333		if (rule->mark)
334			/* compatibility: if the mark value is non-zero all bits
335			 * are compared unless a mask is explicitly specified.
336			 */
337			rule->mark_mask = 0xFFFFFFFF;
338	}
339
340	if (tb[FRA_FWMASK])
341		rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
342
 
 
 
 
 
 
 
 
 
 
 
 
343	rule->action = frh->action;
344	rule->flags = frh->flags;
345	rule->table = frh_get_table(frh, tb);
346	if (tb[FRA_SUPPRESS_PREFIXLEN])
347		rule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
348	else
349		rule->suppress_prefixlen = -1;
350
351	if (tb[FRA_SUPPRESS_IFGROUP])
352		rule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
353	else
354		rule->suppress_ifgroup = -1;
355
356	if (!tb[FRA_PRIORITY] && ops->default_pref)
357		rule->pref = ops->default_pref(ops);
358
359	err = -EINVAL;
360	if (tb[FRA_GOTO]) {
361		if (rule->action != FR_ACT_GOTO)
362			goto errout_free;
363
364		rule->target = nla_get_u32(tb[FRA_GOTO]);
365		/* Backward jumps are prohibited to avoid endless loops */
366		if (rule->target <= rule->pref)
367			goto errout_free;
368
369		list_for_each_entry(r, &ops->rules_list, list) {
370			if (r->pref == rule->target) {
371				RCU_INIT_POINTER(rule->ctarget, r);
372				break;
373			}
374		}
375
376		if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
377			unresolved = 1;
378	} else if (rule->action == FR_ACT_GOTO)
379		goto errout_free;
380
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
381	err = ops->configure(rule, skb, frh, tb);
382	if (err < 0)
383		goto errout_free;
384
 
 
 
 
 
385	list_for_each_entry(r, &ops->rules_list, list) {
386		if (r->pref > rule->pref)
387			break;
388		last = r;
389	}
390
391	fib_rule_get(rule);
392
393	if (last)
394		list_add_rcu(&rule->list, &last->list);
395	else
396		list_add_rcu(&rule->list, &ops->rules_list);
397
398	if (ops->unresolved_rules) {
399		/*
400		 * There are unresolved goto rules in the list, check if
401		 * any of them are pointing to this new rule.
402		 */
403		list_for_each_entry(r, &ops->rules_list, list) {
404			if (r->action == FR_ACT_GOTO &&
405			    r->target == rule->pref &&
406			    rtnl_dereference(r->ctarget) == NULL) {
407				rcu_assign_pointer(r->ctarget, rule);
408				if (--ops->unresolved_rules == 0)
409					break;
410			}
411		}
412	}
413
414	if (rule->action == FR_ACT_GOTO)
415		ops->nr_goto_rules++;
416
417	if (unresolved)
418		ops->unresolved_rules++;
419
 
 
 
420	notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
421	flush_route_cache(ops);
422	rules_ops_put(ops);
423	return 0;
424
425errout_free:
426	release_net(rule->fr_net);
427	kfree(rule);
428errout:
429	rules_ops_put(ops);
430	return err;
431}
 
432
433static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh)
 
434{
435	struct net *net = sock_net(skb->sk);
436	struct fib_rule_hdr *frh = nlmsg_data(nlh);
 
 
437	struct fib_rules_ops *ops = NULL;
438	struct fib_rule *rule, *tmp;
439	struct nlattr *tb[FRA_MAX+1];
 
440	int err = -EINVAL;
441
442	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
443		goto errout;
444
445	ops = lookup_rules_ops(net, frh->family);
446	if (ops == NULL) {
447		err = -EAFNOSUPPORT;
448		goto errout;
449	}
450
451	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
452	if (err < 0)
453		goto errout;
454
455	err = validate_rulemsg(frh, tb, ops);
456	if (err < 0)
457		goto errout;
458
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
459	list_for_each_entry(rule, &ops->rules_list, list) {
 
 
 
 
460		if (frh->action && (frh->action != rule->action))
461			continue;
462
463		if (frh_get_table(frh, tb) &&
464		    (frh_get_table(frh, tb) != rule->table))
465			continue;
466
467		if (tb[FRA_PRIORITY] &&
468		    (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
469			continue;
470
471		if (tb[FRA_IIFNAME] &&
472		    nla_strcmp(tb[FRA_IIFNAME], rule->iifname))
473			continue;
474
475		if (tb[FRA_OIFNAME] &&
476		    nla_strcmp(tb[FRA_OIFNAME], rule->oifname))
477			continue;
478
479		if (tb[FRA_FWMARK] &&
480		    (rule->mark != nla_get_u32(tb[FRA_FWMARK])))
481			continue;
482
483		if (tb[FRA_FWMASK] &&
484		    (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK])))
485			continue;
486
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
487		if (!ops->compare(rule, frh, tb))
488			continue;
489
490		if (rule->flags & FIB_RULE_PERMANENT) {
491			err = -EPERM;
492			goto errout;
493		}
494
 
 
 
 
 
 
 
 
 
495		list_del_rcu(&rule->list);
496
497		if (rule->action == FR_ACT_GOTO) {
498			ops->nr_goto_rules--;
499			if (rtnl_dereference(rule->ctarget) == NULL)
500				ops->unresolved_rules--;
501		}
502
503		/*
504		 * Check if this rule is a target to any of them. If so,
 
505		 * disable them. As this operation is eventually very
506		 * expensive, it is only performed if goto rules have
507		 * actually been added.
508		 */
509		if (ops->nr_goto_rules > 0) {
510			list_for_each_entry(tmp, &ops->rules_list, list) {
511				if (rtnl_dereference(tmp->ctarget) == rule) {
512					RCU_INIT_POINTER(tmp->ctarget, NULL);
 
 
 
 
 
 
 
513					ops->unresolved_rules++;
514				}
515			}
516		}
517
 
 
518		notify_rule_change(RTM_DELRULE, rule, ops, nlh,
519				   NETLINK_CB(skb).portid);
520		if (ops->delete)
521			ops->delete(rule);
522		fib_rule_put(rule);
523		flush_route_cache(ops);
524		rules_ops_put(ops);
525		return 0;
526	}
527
528	err = -ENOENT;
529errout:
530	rules_ops_put(ops);
531	return err;
532}
 
533
534static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
535					 struct fib_rule *rule)
536{
537	size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
538			 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
539			 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
540			 + nla_total_size(4) /* FRA_PRIORITY */
541			 + nla_total_size(4) /* FRA_TABLE */
542			 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
543			 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
544			 + nla_total_size(4) /* FRA_FWMARK */
545			 + nla_total_size(4); /* FRA_FWMASK */
 
 
 
 
 
 
546
547	if (ops->nlmsg_payload)
548		payload += ops->nlmsg_payload(rule);
549
550	return payload;
551}
552
553static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
554			    u32 pid, u32 seq, int type, int flags,
555			    struct fib_rules_ops *ops)
556{
557	struct nlmsghdr *nlh;
558	struct fib_rule_hdr *frh;
559
560	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
561	if (nlh == NULL)
562		return -EMSGSIZE;
563
564	frh = nlmsg_data(nlh);
565	frh->family = ops->family;
566	frh->table = rule->table;
567	if (nla_put_u32(skb, FRA_TABLE, rule->table))
568		goto nla_put_failure;
569	if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
570		goto nla_put_failure;
571	frh->res1 = 0;
572	frh->res2 = 0;
573	frh->action = rule->action;
574	frh->flags = rule->flags;
575
 
 
 
576	if (rule->action == FR_ACT_GOTO &&
577	    rcu_access_pointer(rule->ctarget) == NULL)
578		frh->flags |= FIB_RULE_UNRESOLVED;
579
580	if (rule->iifname[0]) {
581		if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
582			goto nla_put_failure;
583		if (rule->iifindex == -1)
584			frh->flags |= FIB_RULE_IIF_DETACHED;
585	}
586
587	if (rule->oifname[0]) {
588		if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
589			goto nla_put_failure;
590		if (rule->oifindex == -1)
591			frh->flags |= FIB_RULE_OIF_DETACHED;
592	}
593
594	if ((rule->pref &&
595	     nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
596	    (rule->mark &&
597	     nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
598	    ((rule->mark_mask || rule->mark) &&
599	     nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
600	    (rule->target &&
601	     nla_put_u32(skb, FRA_GOTO, rule->target)))
 
 
 
 
 
 
 
 
 
 
 
602		goto nla_put_failure;
603
604	if (rule->suppress_ifgroup != -1) {
605		if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
606			goto nla_put_failure;
607	}
608
609	if (ops->fill(rule, skb, frh) < 0)
610		goto nla_put_failure;
611
612	return nlmsg_end(skb, nlh);
 
613
614nla_put_failure:
615	nlmsg_cancel(skb, nlh);
616	return -EMSGSIZE;
617}
618
619static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
620		      struct fib_rules_ops *ops)
621{
622	int idx = 0;
623	struct fib_rule *rule;
 
624
625	rcu_read_lock();
626	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
627		if (idx < cb->args[1])
628			goto skip;
629
630		if (fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
631				     cb->nlh->nlmsg_seq, RTM_NEWRULE,
632				     NLM_F_MULTI, ops) < 0)
 
633			break;
634skip:
635		idx++;
636	}
637	rcu_read_unlock();
638	cb->args[1] = idx;
639	rules_ops_put(ops);
640
641	return skb->len;
642}
643
644static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
645{
646	struct net *net = sock_net(skb->sk);
647	struct fib_rules_ops *ops;
648	int idx = 0, family;
649
650	family = rtnl_msg_family(cb->nlh);
651	if (family != AF_UNSPEC) {
652		/* Protocol specific dump request */
653		ops = lookup_rules_ops(net, family);
654		if (ops == NULL)
655			return -EAFNOSUPPORT;
656
657		return dump_rules(skb, cb, ops);
 
 
658	}
659
660	rcu_read_lock();
661	list_for_each_entry_rcu(ops, &net->rules_ops, list) {
662		if (idx < cb->args[0] || !try_module_get(ops->owner))
663			goto skip;
664
665		if (dump_rules(skb, cb, ops) < 0)
666			break;
667
668		cb->args[1] = 0;
669skip:
670		idx++;
671	}
672	rcu_read_unlock();
673	cb->args[0] = idx;
674
675	return skb->len;
676}
677
678static void notify_rule_change(int event, struct fib_rule *rule,
679			       struct fib_rules_ops *ops, struct nlmsghdr *nlh,
680			       u32 pid)
681{
682	struct net *net;
683	struct sk_buff *skb;
684	int err = -ENOBUFS;
685
686	net = ops->fro_net;
687	skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
688	if (skb == NULL)
689		goto errout;
690
691	err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
692	if (err < 0) {
693		/* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
694		WARN_ON(err == -EMSGSIZE);
695		kfree_skb(skb);
696		goto errout;
697	}
698
699	rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
700	return;
701errout:
702	if (err < 0)
703		rtnl_set_sk_err(net, ops->nlgroup, err);
704}
705
706static void attach_rules(struct list_head *rules, struct net_device *dev)
707{
708	struct fib_rule *rule;
709
710	list_for_each_entry(rule, rules, list) {
711		if (rule->iifindex == -1 &&
712		    strcmp(dev->name, rule->iifname) == 0)
713			rule->iifindex = dev->ifindex;
714		if (rule->oifindex == -1 &&
715		    strcmp(dev->name, rule->oifname) == 0)
716			rule->oifindex = dev->ifindex;
717	}
718}
719
720static void detach_rules(struct list_head *rules, struct net_device *dev)
721{
722	struct fib_rule *rule;
723
724	list_for_each_entry(rule, rules, list) {
725		if (rule->iifindex == dev->ifindex)
726			rule->iifindex = -1;
727		if (rule->oifindex == dev->ifindex)
728			rule->oifindex = -1;
729	}
730}
731
732
733static int fib_rules_event(struct notifier_block *this, unsigned long event,
734			   void *ptr)
735{
736	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
737	struct net *net = dev_net(dev);
738	struct fib_rules_ops *ops;
739
740	ASSERT_RTNL();
741
742	switch (event) {
743	case NETDEV_REGISTER:
744		list_for_each_entry(ops, &net->rules_ops, list)
745			attach_rules(&ops->rules_list, dev);
746		break;
747
748	case NETDEV_CHANGENAME:
749		list_for_each_entry(ops, &net->rules_ops, list) {
750			detach_rules(&ops->rules_list, dev);
751			attach_rules(&ops->rules_list, dev);
752		}
753		break;
754
755	case NETDEV_UNREGISTER:
756		list_for_each_entry(ops, &net->rules_ops, list)
757			detach_rules(&ops->rules_list, dev);
758		break;
759	}
760
761	return NOTIFY_DONE;
762}
763
764static struct notifier_block fib_rules_notifier = {
765	.notifier_call = fib_rules_event,
766};
767
768static int __net_init fib_rules_net_init(struct net *net)
769{
770	INIT_LIST_HEAD(&net->rules_ops);
771	spin_lock_init(&net->rules_mod_lock);
772	return 0;
773}
774
 
 
 
 
 
775static struct pernet_operations fib_rules_net_ops = {
776	.init = fib_rules_net_init,
 
777};
778
779static int __init fib_rules_init(void)
780{
781	int err;
782	rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, NULL);
783	rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, NULL);
784	rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, NULL);
785
786	err = register_pernet_subsys(&fib_rules_net_ops);
787	if (err < 0)
788		goto fail;
789
790	err = register_netdevice_notifier(&fib_rules_notifier);
791	if (err < 0)
792		goto fail_unregister;
793
794	return 0;
795
796fail_unregister:
797	unregister_pernet_subsys(&fib_rules_net_ops);
798fail:
799	rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
800	rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
801	rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
802	return err;
803}
804
805subsys_initcall(fib_rules_init);
v4.17
   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
  11#include <linux/types.h>
  12#include <linux/kernel.h>
  13#include <linux/slab.h>
  14#include <linux/list.h>
  15#include <linux/module.h>
  16#include <net/net_namespace.h>
  17#include <net/sock.h>
  18#include <net/fib_rules.h>
  19#include <net/ip_tunnels.h>
  20
  21static const struct fib_kuid_range fib_kuid_range_unset = {
  22	KUIDT_INIT(0),
  23	KUIDT_INIT(~0),
  24};
  25
  26bool fib_rule_matchall(const struct fib_rule *rule)
  27{
  28	if (rule->iifindex || rule->oifindex || rule->mark || rule->tun_id ||
  29	    rule->flags)
  30		return false;
  31	if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1)
  32		return false;
  33	if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) ||
  34	    !uid_eq(rule->uid_range.end, fib_kuid_range_unset.end))
  35		return false;
  36	if (fib_rule_port_range_set(&rule->sport_range))
  37		return false;
  38	if (fib_rule_port_range_set(&rule->dport_range))
  39		return false;
  40	return true;
  41}
  42EXPORT_SYMBOL_GPL(fib_rule_matchall);
  43
  44int fib_default_rule_add(struct fib_rules_ops *ops,
  45			 u32 pref, u32 table, u32 flags)
  46{
  47	struct fib_rule *r;
  48
  49	r = kzalloc(ops->rule_size, GFP_KERNEL);
  50	if (r == NULL)
  51		return -ENOMEM;
  52
  53	refcount_set(&r->refcnt, 1);
  54	r->action = FR_ACT_TO_TBL;
  55	r->pref = pref;
  56	r->table = table;
  57	r->flags = flags;
  58	r->proto = RTPROT_KERNEL;
  59	r->fr_net = ops->fro_net;
  60	r->uid_range = fib_kuid_range_unset;
  61
  62	r->suppress_prefixlen = -1;
  63	r->suppress_ifgroup = -1;
  64
  65	/* The lock is not required here, the list in unreacheable
  66	 * at the moment this function is called */
  67	list_add_tail(&r->list, &ops->rules_list);
  68	return 0;
  69}
  70EXPORT_SYMBOL(fib_default_rule_add);
  71
  72static u32 fib_default_rule_pref(struct fib_rules_ops *ops)
  73{
  74	struct list_head *pos;
  75	struct fib_rule *rule;
  76
  77	if (!list_empty(&ops->rules_list)) {
  78		pos = ops->rules_list.next;
  79		if (pos->next != &ops->rules_list) {
  80			rule = list_entry(pos->next, struct fib_rule, list);
  81			if (rule->pref)
  82				return rule->pref - 1;
  83		}
  84	}
  85
  86	return 0;
  87}
 
  88
  89static void notify_rule_change(int event, struct fib_rule *rule,
  90			       struct fib_rules_ops *ops, struct nlmsghdr *nlh,
  91			       u32 pid);
  92
  93static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family)
  94{
  95	struct fib_rules_ops *ops;
  96
  97	rcu_read_lock();
  98	list_for_each_entry_rcu(ops, &net->rules_ops, list) {
  99		if (ops->family == family) {
 100			if (!try_module_get(ops->owner))
 101				ops = NULL;
 102			rcu_read_unlock();
 103			return ops;
 104		}
 105	}
 106	rcu_read_unlock();
 107
 108	return NULL;
 109}
 110
 111static void rules_ops_put(struct fib_rules_ops *ops)
 112{
 113	if (ops)
 114		module_put(ops->owner);
 115}
 116
 117static void flush_route_cache(struct fib_rules_ops *ops)
 118{
 119	if (ops->flush_cache)
 120		ops->flush_cache(ops);
 121}
 122
 123static int __fib_rules_register(struct fib_rules_ops *ops)
 124{
 125	int err = -EEXIST;
 126	struct fib_rules_ops *o;
 127	struct net *net;
 128
 129	net = ops->fro_net;
 130
 131	if (ops->rule_size < sizeof(struct fib_rule))
 132		return -EINVAL;
 133
 134	if (ops->match == NULL || ops->configure == NULL ||
 135	    ops->compare == NULL || ops->fill == NULL ||
 136	    ops->action == NULL)
 137		return -EINVAL;
 138
 139	spin_lock(&net->rules_mod_lock);
 140	list_for_each_entry(o, &net->rules_ops, list)
 141		if (ops->family == o->family)
 142			goto errout;
 143
 
 144	list_add_tail_rcu(&ops->list, &net->rules_ops);
 145	err = 0;
 146errout:
 147	spin_unlock(&net->rules_mod_lock);
 148
 149	return err;
 150}
 151
 152struct fib_rules_ops *
 153fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
 154{
 155	struct fib_rules_ops *ops;
 156	int err;
 157
 158	ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
 159	if (ops == NULL)
 160		return ERR_PTR(-ENOMEM);
 161
 162	INIT_LIST_HEAD(&ops->rules_list);
 163	ops->fro_net = net;
 164
 165	err = __fib_rules_register(ops);
 166	if (err) {
 167		kfree(ops);
 168		ops = ERR_PTR(err);
 169	}
 170
 171	return ops;
 172}
 173EXPORT_SYMBOL_GPL(fib_rules_register);
 174
 175static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
 176{
 177	struct fib_rule *rule, *tmp;
 178
 179	list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
 180		list_del_rcu(&rule->list);
 181		if (ops->delete)
 182			ops->delete(rule);
 183		fib_rule_put(rule);
 184	}
 185}
 186
 
 
 
 
 
 
 
 
 
 187void fib_rules_unregister(struct fib_rules_ops *ops)
 188{
 189	struct net *net = ops->fro_net;
 190
 191	spin_lock(&net->rules_mod_lock);
 192	list_del_rcu(&ops->list);
 
 193	spin_unlock(&net->rules_mod_lock);
 194
 195	fib_rules_cleanup_ops(ops);
 196	kfree_rcu(ops, rcu);
 197}
 198EXPORT_SYMBOL_GPL(fib_rules_unregister);
 199
 200static int uid_range_set(struct fib_kuid_range *range)
 201{
 202	return uid_valid(range->start) && uid_valid(range->end);
 203}
 204
 205static struct fib_kuid_range nla_get_kuid_range(struct nlattr **tb)
 206{
 207	struct fib_rule_uid_range *in;
 208	struct fib_kuid_range out;
 209
 210	in = (struct fib_rule_uid_range *)nla_data(tb[FRA_UID_RANGE]);
 211
 212	out.start = make_kuid(current_user_ns(), in->start);
 213	out.end = make_kuid(current_user_ns(), in->end);
 214
 215	return out;
 216}
 217
 218static int nla_put_uid_range(struct sk_buff *skb, struct fib_kuid_range *range)
 219{
 220	struct fib_rule_uid_range out = {
 221		from_kuid_munged(current_user_ns(), range->start),
 222		from_kuid_munged(current_user_ns(), range->end)
 223	};
 224
 225	return nla_put(skb, FRA_UID_RANGE, sizeof(out), &out);
 226}
 227
 228static int nla_get_port_range(struct nlattr *pattr,
 229			      struct fib_rule_port_range *port_range)
 230{
 231	const struct fib_rule_port_range *pr = nla_data(pattr);
 232
 233	if (!fib_rule_port_range_valid(pr))
 234		return -EINVAL;
 235
 236	port_range->start = pr->start;
 237	port_range->end = pr->end;
 238
 239	return 0;
 240}
 241
 242static int nla_put_port_range(struct sk_buff *skb, int attrtype,
 243			      struct fib_rule_port_range *range)
 244{
 245	return nla_put(skb, attrtype, sizeof(*range), range);
 246}
 247
 248static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
 249			  struct flowi *fl, int flags,
 250			  struct fib_lookup_arg *arg)
 251{
 252	int ret = 0;
 253
 254	if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
 255		goto out;
 256
 257	if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
 258		goto out;
 259
 260	if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
 261		goto out;
 262
 263	if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id))
 264		goto out;
 265
 266	if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg))
 267		goto out;
 268
 269	if (uid_lt(fl->flowi_uid, rule->uid_range.start) ||
 270	    uid_gt(fl->flowi_uid, rule->uid_range.end))
 271		goto out;
 272
 273	ret = ops->match(rule, fl, flags);
 274out:
 275	return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
 276}
 277
 278int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
 279		     int flags, struct fib_lookup_arg *arg)
 280{
 281	struct fib_rule *rule;
 282	int err;
 283
 284	rcu_read_lock();
 285
 286	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
 287jumped:
 288		if (!fib_rule_match(rule, ops, fl, flags, arg))
 289			continue;
 290
 291		if (rule->action == FR_ACT_GOTO) {
 292			struct fib_rule *target;
 293
 294			target = rcu_dereference(rule->ctarget);
 295			if (target == NULL) {
 296				continue;
 297			} else {
 298				rule = target;
 299				goto jumped;
 300			}
 301		} else if (rule->action == FR_ACT_NOP)
 302			continue;
 303		else
 304			err = ops->action(rule, fl, flags, arg);
 305
 306		if (!err && ops->suppress && ops->suppress(rule, arg))
 307			continue;
 308
 309		if (err != -EAGAIN) {
 310			if ((arg->flags & FIB_LOOKUP_NOREF) ||
 311			    likely(refcount_inc_not_zero(&rule->refcnt))) {
 312				arg->rule = rule;
 313				goto out;
 314			}
 315			break;
 316		}
 317	}
 318
 319	err = -ESRCH;
 320out:
 321	rcu_read_unlock();
 322
 323	return err;
 324}
 325EXPORT_SYMBOL_GPL(fib_rules_lookup);
 326
 327static int call_fib_rule_notifier(struct notifier_block *nb, struct net *net,
 328				  enum fib_event_type event_type,
 329				  struct fib_rule *rule, int family)
 330{
 331	struct fib_rule_notifier_info info = {
 332		.info.family = family,
 333		.rule = rule,
 334	};
 335
 336	return call_fib_notifier(nb, net, event_type, &info.info);
 337}
 338
 339static int call_fib_rule_notifiers(struct net *net,
 340				   enum fib_event_type event_type,
 341				   struct fib_rule *rule,
 342				   struct fib_rules_ops *ops,
 343				   struct netlink_ext_ack *extack)
 344{
 345	struct fib_rule_notifier_info info = {
 346		.info.family = ops->family,
 347		.info.extack = extack,
 348		.rule = rule,
 349	};
 350
 351	ops->fib_rules_seq++;
 352	return call_fib_notifiers(net, event_type, &info.info);
 353}
 354
 355/* Called with rcu_read_lock() */
 356int fib_rules_dump(struct net *net, struct notifier_block *nb, int family)
 357{
 358	struct fib_rules_ops *ops;
 359	struct fib_rule *rule;
 360
 361	ops = lookup_rules_ops(net, family);
 362	if (!ops)
 363		return -EAFNOSUPPORT;
 364	list_for_each_entry_rcu(rule, &ops->rules_list, list)
 365		call_fib_rule_notifier(nb, net, FIB_EVENT_RULE_ADD, rule,
 366				       family);
 367	rules_ops_put(ops);
 368
 369	return 0;
 370}
 371EXPORT_SYMBOL_GPL(fib_rules_dump);
 372
 373unsigned int fib_rules_seq_read(struct net *net, int family)
 374{
 375	unsigned int fib_rules_seq;
 376	struct fib_rules_ops *ops;
 377
 378	ASSERT_RTNL();
 379
 380	ops = lookup_rules_ops(net, family);
 381	if (!ops)
 382		return 0;
 383	fib_rules_seq = ops->fib_rules_seq;
 384	rules_ops_put(ops);
 385
 386	return fib_rules_seq;
 387}
 388EXPORT_SYMBOL_GPL(fib_rules_seq_read);
 389
 390static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb,
 391			    struct fib_rules_ops *ops)
 392{
 393	int err = -EINVAL;
 394
 395	if (frh->src_len)
 396		if (tb[FRA_SRC] == NULL ||
 397		    frh->src_len > (ops->addr_size * 8) ||
 398		    nla_len(tb[FRA_SRC]) != ops->addr_size)
 399			goto errout;
 400
 401	if (frh->dst_len)
 402		if (tb[FRA_DST] == NULL ||
 403		    frh->dst_len > (ops->addr_size * 8) ||
 404		    nla_len(tb[FRA_DST]) != ops->addr_size)
 405			goto errout;
 406
 407	err = 0;
 408errout:
 409	return err;
 410}
 411
 412static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh,
 413		       struct nlattr **tb, struct fib_rule *rule)
 414{
 415	struct fib_rule *r;
 416
 417	list_for_each_entry(r, &ops->rules_list, list) {
 418		if (r->action != rule->action)
 419			continue;
 420
 421		if (r->table != rule->table)
 422			continue;
 423
 424		if (r->pref != rule->pref)
 425			continue;
 426
 427		if (memcmp(r->iifname, rule->iifname, IFNAMSIZ))
 428			continue;
 429
 430		if (memcmp(r->oifname, rule->oifname, IFNAMSIZ))
 431			continue;
 432
 433		if (r->mark != rule->mark)
 434			continue;
 435
 436		if (r->mark_mask != rule->mark_mask)
 437			continue;
 438
 439		if (r->tun_id != rule->tun_id)
 440			continue;
 441
 442		if (r->fr_net != rule->fr_net)
 443			continue;
 444
 445		if (r->l3mdev != rule->l3mdev)
 446			continue;
 447
 448		if (!uid_eq(r->uid_range.start, rule->uid_range.start) ||
 449		    !uid_eq(r->uid_range.end, rule->uid_range.end))
 450			continue;
 451
 452		if (r->ip_proto != rule->ip_proto)
 453			continue;
 454
 455		if (!fib_rule_port_range_compare(&r->sport_range,
 456						 &rule->sport_range))
 457			continue;
 458
 459		if (!fib_rule_port_range_compare(&r->dport_range,
 460						 &rule->dport_range))
 461			continue;
 462
 463		if (!ops->compare(r, frh, tb))
 464			continue;
 465		return 1;
 466	}
 467	return 0;
 468}
 469
 470int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
 471		   struct netlink_ext_ack *extack)
 472{
 473	struct net *net = sock_net(skb->sk);
 474	struct fib_rule_hdr *frh = nlmsg_data(nlh);
 475	struct fib_rules_ops *ops = NULL;
 476	struct fib_rule *rule, *r, *last = NULL;
 477	struct nlattr *tb[FRA_MAX+1];
 478	int err = -EINVAL, unresolved = 0;
 479
 480	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 481		goto errout;
 482
 483	ops = lookup_rules_ops(net, frh->family);
 484	if (ops == NULL) {
 485		err = -EAFNOSUPPORT;
 486		goto errout;
 487	}
 488
 489	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack);
 490	if (err < 0)
 491		goto errout;
 492
 493	err = validate_rulemsg(frh, tb, ops);
 494	if (err < 0)
 495		goto errout;
 496
 497	rule = kzalloc(ops->rule_size, GFP_KERNEL);
 498	if (rule == NULL) {
 499		err = -ENOMEM;
 500		goto errout;
 501	}
 502	refcount_set(&rule->refcnt, 1);
 503	rule->fr_net = net;
 504
 505	rule->pref = tb[FRA_PRIORITY] ? nla_get_u32(tb[FRA_PRIORITY])
 506	                              : fib_default_rule_pref(ops);
 507
 508	rule->proto = tb[FRA_PROTOCOL] ?
 509		nla_get_u8(tb[FRA_PROTOCOL]) : RTPROT_UNSPEC;
 510
 511	if (tb[FRA_IIFNAME]) {
 512		struct net_device *dev;
 513
 514		rule->iifindex = -1;
 515		nla_strlcpy(rule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
 516		dev = __dev_get_by_name(net, rule->iifname);
 517		if (dev)
 518			rule->iifindex = dev->ifindex;
 519	}
 520
 521	if (tb[FRA_OIFNAME]) {
 522		struct net_device *dev;
 523
 524		rule->oifindex = -1;
 525		nla_strlcpy(rule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
 526		dev = __dev_get_by_name(net, rule->oifname);
 527		if (dev)
 528			rule->oifindex = dev->ifindex;
 529	}
 530
 531	if (tb[FRA_FWMARK]) {
 532		rule->mark = nla_get_u32(tb[FRA_FWMARK]);
 533		if (rule->mark)
 534			/* compatibility: if the mark value is non-zero all bits
 535			 * are compared unless a mask is explicitly specified.
 536			 */
 537			rule->mark_mask = 0xFFFFFFFF;
 538	}
 539
 540	if (tb[FRA_FWMASK])
 541		rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
 542
 543	if (tb[FRA_TUN_ID])
 544		rule->tun_id = nla_get_be64(tb[FRA_TUN_ID]);
 545
 546	err = -EINVAL;
 547	if (tb[FRA_L3MDEV]) {
 548#ifdef CONFIG_NET_L3_MASTER_DEV
 549		rule->l3mdev = nla_get_u8(tb[FRA_L3MDEV]);
 550		if (rule->l3mdev != 1)
 551#endif
 552			goto errout_free;
 553	}
 554
 555	rule->action = frh->action;
 556	rule->flags = frh->flags;
 557	rule->table = frh_get_table(frh, tb);
 558	if (tb[FRA_SUPPRESS_PREFIXLEN])
 559		rule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
 560	else
 561		rule->suppress_prefixlen = -1;
 562
 563	if (tb[FRA_SUPPRESS_IFGROUP])
 564		rule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
 565	else
 566		rule->suppress_ifgroup = -1;
 567
 
 
 
 
 568	if (tb[FRA_GOTO]) {
 569		if (rule->action != FR_ACT_GOTO)
 570			goto errout_free;
 571
 572		rule->target = nla_get_u32(tb[FRA_GOTO]);
 573		/* Backward jumps are prohibited to avoid endless loops */
 574		if (rule->target <= rule->pref)
 575			goto errout_free;
 576
 577		list_for_each_entry(r, &ops->rules_list, list) {
 578			if (r->pref == rule->target) {
 579				RCU_INIT_POINTER(rule->ctarget, r);
 580				break;
 581			}
 582		}
 583
 584		if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
 585			unresolved = 1;
 586	} else if (rule->action == FR_ACT_GOTO)
 587		goto errout_free;
 588
 589	if (rule->l3mdev && rule->table)
 590		goto errout_free;
 591
 592	if (tb[FRA_UID_RANGE]) {
 593		if (current_user_ns() != net->user_ns) {
 594			err = -EPERM;
 595			goto errout_free;
 596		}
 597
 598		rule->uid_range = nla_get_kuid_range(tb);
 599
 600		if (!uid_range_set(&rule->uid_range) ||
 601		    !uid_lte(rule->uid_range.start, rule->uid_range.end))
 602			goto errout_free;
 603	} else {
 604		rule->uid_range = fib_kuid_range_unset;
 605	}
 606
 607	if (tb[FRA_IP_PROTO])
 608		rule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]);
 609
 610	if (tb[FRA_SPORT_RANGE]) {
 611		err = nla_get_port_range(tb[FRA_SPORT_RANGE],
 612					 &rule->sport_range);
 613		if (err)
 614			goto errout_free;
 615	}
 616
 617	if (tb[FRA_DPORT_RANGE]) {
 618		err = nla_get_port_range(tb[FRA_DPORT_RANGE],
 619					 &rule->dport_range);
 620		if (err)
 621			goto errout_free;
 622	}
 623
 624	if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
 625	    rule_exists(ops, frh, tb, rule)) {
 626		err = -EEXIST;
 627		goto errout_free;
 628	}
 629
 630	err = ops->configure(rule, skb, frh, tb);
 631	if (err < 0)
 632		goto errout_free;
 633
 634	err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops,
 635				      extack);
 636	if (err < 0)
 637		goto errout_free;
 638
 639	list_for_each_entry(r, &ops->rules_list, list) {
 640		if (r->pref > rule->pref)
 641			break;
 642		last = r;
 643	}
 644
 
 
 645	if (last)
 646		list_add_rcu(&rule->list, &last->list);
 647	else
 648		list_add_rcu(&rule->list, &ops->rules_list);
 649
 650	if (ops->unresolved_rules) {
 651		/*
 652		 * There are unresolved goto rules in the list, check if
 653		 * any of them are pointing to this new rule.
 654		 */
 655		list_for_each_entry(r, &ops->rules_list, list) {
 656			if (r->action == FR_ACT_GOTO &&
 657			    r->target == rule->pref &&
 658			    rtnl_dereference(r->ctarget) == NULL) {
 659				rcu_assign_pointer(r->ctarget, rule);
 660				if (--ops->unresolved_rules == 0)
 661					break;
 662			}
 663		}
 664	}
 665
 666	if (rule->action == FR_ACT_GOTO)
 667		ops->nr_goto_rules++;
 668
 669	if (unresolved)
 670		ops->unresolved_rules++;
 671
 672	if (rule->tun_id)
 673		ip_tunnel_need_metadata();
 674
 675	notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
 676	flush_route_cache(ops);
 677	rules_ops_put(ops);
 678	return 0;
 679
 680errout_free:
 
 681	kfree(rule);
 682errout:
 683	rules_ops_put(ops);
 684	return err;
 685}
 686EXPORT_SYMBOL_GPL(fib_nl_newrule);
 687
 688int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh,
 689		   struct netlink_ext_ack *extack)
 690{
 691	struct net *net = sock_net(skb->sk);
 692	struct fib_rule_hdr *frh = nlmsg_data(nlh);
 693	struct fib_rule_port_range sprange = {0, 0};
 694	struct fib_rule_port_range dprange = {0, 0};
 695	struct fib_rules_ops *ops = NULL;
 696	struct fib_rule *rule, *r;
 697	struct nlattr *tb[FRA_MAX+1];
 698	struct fib_kuid_range range;
 699	int err = -EINVAL;
 700
 701	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 702		goto errout;
 703
 704	ops = lookup_rules_ops(net, frh->family);
 705	if (ops == NULL) {
 706		err = -EAFNOSUPPORT;
 707		goto errout;
 708	}
 709
 710	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack);
 711	if (err < 0)
 712		goto errout;
 713
 714	err = validate_rulemsg(frh, tb, ops);
 715	if (err < 0)
 716		goto errout;
 717
 718	if (tb[FRA_UID_RANGE]) {
 719		range = nla_get_kuid_range(tb);
 720		if (!uid_range_set(&range)) {
 721			err = -EINVAL;
 722			goto errout;
 723		}
 724	} else {
 725		range = fib_kuid_range_unset;
 726	}
 727
 728	if (tb[FRA_SPORT_RANGE]) {
 729		err = nla_get_port_range(tb[FRA_SPORT_RANGE],
 730					 &sprange);
 731		if (err)
 732			goto errout;
 733	}
 734
 735	if (tb[FRA_DPORT_RANGE]) {
 736		err = nla_get_port_range(tb[FRA_DPORT_RANGE],
 737					 &dprange);
 738		if (err)
 739			goto errout;
 740	}
 741
 742	list_for_each_entry(rule, &ops->rules_list, list) {
 743		if (tb[FRA_PROTOCOL] &&
 744		    (rule->proto != nla_get_u8(tb[FRA_PROTOCOL])))
 745			continue;
 746
 747		if (frh->action && (frh->action != rule->action))
 748			continue;
 749
 750		if (frh_get_table(frh, tb) &&
 751		    (frh_get_table(frh, tb) != rule->table))
 752			continue;
 753
 754		if (tb[FRA_PRIORITY] &&
 755		    (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
 756			continue;
 757
 758		if (tb[FRA_IIFNAME] &&
 759		    nla_strcmp(tb[FRA_IIFNAME], rule->iifname))
 760			continue;
 761
 762		if (tb[FRA_OIFNAME] &&
 763		    nla_strcmp(tb[FRA_OIFNAME], rule->oifname))
 764			continue;
 765
 766		if (tb[FRA_FWMARK] &&
 767		    (rule->mark != nla_get_u32(tb[FRA_FWMARK])))
 768			continue;
 769
 770		if (tb[FRA_FWMASK] &&
 771		    (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK])))
 772			continue;
 773
 774		if (tb[FRA_TUN_ID] &&
 775		    (rule->tun_id != nla_get_be64(tb[FRA_TUN_ID])))
 776			continue;
 777
 778		if (tb[FRA_L3MDEV] &&
 779		    (rule->l3mdev != nla_get_u8(tb[FRA_L3MDEV])))
 780			continue;
 781
 782		if (uid_range_set(&range) &&
 783		    (!uid_eq(rule->uid_range.start, range.start) ||
 784		     !uid_eq(rule->uid_range.end, range.end)))
 785			continue;
 786
 787		if (tb[FRA_IP_PROTO] &&
 788		    (rule->ip_proto != nla_get_u8(tb[FRA_IP_PROTO])))
 789			continue;
 790
 791		if (fib_rule_port_range_set(&sprange) &&
 792		    !fib_rule_port_range_compare(&rule->sport_range, &sprange))
 793			continue;
 794
 795		if (fib_rule_port_range_set(&dprange) &&
 796		    !fib_rule_port_range_compare(&rule->dport_range, &dprange))
 797			continue;
 798
 799		if (!ops->compare(rule, frh, tb))
 800			continue;
 801
 802		if (rule->flags & FIB_RULE_PERMANENT) {
 803			err = -EPERM;
 804			goto errout;
 805		}
 806
 807		if (ops->delete) {
 808			err = ops->delete(rule);
 809			if (err)
 810				goto errout;
 811		}
 812
 813		if (rule->tun_id)
 814			ip_tunnel_unneed_metadata();
 815
 816		list_del_rcu(&rule->list);
 817
 818		if (rule->action == FR_ACT_GOTO) {
 819			ops->nr_goto_rules--;
 820			if (rtnl_dereference(rule->ctarget) == NULL)
 821				ops->unresolved_rules--;
 822		}
 823
 824		/*
 825		 * Check if this rule is a target to any of them. If so,
 826		 * adjust to the next one with the same preference or
 827		 * disable them. As this operation is eventually very
 828		 * expensive, it is only performed if goto rules, except
 829		 * current if it is goto rule, have actually been added.
 830		 */
 831		if (ops->nr_goto_rules > 0) {
 832			struct fib_rule *n;
 833
 834			n = list_next_entry(rule, list);
 835			if (&n->list == &ops->rules_list || n->pref != rule->pref)
 836				n = NULL;
 837			list_for_each_entry(r, &ops->rules_list, list) {
 838				if (rtnl_dereference(r->ctarget) != rule)
 839					continue;
 840				rcu_assign_pointer(r->ctarget, n);
 841				if (!n)
 842					ops->unresolved_rules++;
 
 843			}
 844		}
 845
 846		call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops,
 847					NULL);
 848		notify_rule_change(RTM_DELRULE, rule, ops, nlh,
 849				   NETLINK_CB(skb).portid);
 
 
 850		fib_rule_put(rule);
 851		flush_route_cache(ops);
 852		rules_ops_put(ops);
 853		return 0;
 854	}
 855
 856	err = -ENOENT;
 857errout:
 858	rules_ops_put(ops);
 859	return err;
 860}
 861EXPORT_SYMBOL_GPL(fib_nl_delrule);
 862
 863static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
 864					 struct fib_rule *rule)
 865{
 866	size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
 867			 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
 868			 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
 869			 + nla_total_size(4) /* FRA_PRIORITY */
 870			 + nla_total_size(4) /* FRA_TABLE */
 871			 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
 872			 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
 873			 + nla_total_size(4) /* FRA_FWMARK */
 874			 + nla_total_size(4) /* FRA_FWMASK */
 875			 + nla_total_size_64bit(8) /* FRA_TUN_ID */
 876			 + nla_total_size(sizeof(struct fib_kuid_range))
 877			 + nla_total_size(1) /* FRA_PROTOCOL */
 878			 + nla_total_size(1) /* FRA_IP_PROTO */
 879			 + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */
 880			 + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */
 881
 882	if (ops->nlmsg_payload)
 883		payload += ops->nlmsg_payload(rule);
 884
 885	return payload;
 886}
 887
 888static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
 889			    u32 pid, u32 seq, int type, int flags,
 890			    struct fib_rules_ops *ops)
 891{
 892	struct nlmsghdr *nlh;
 893	struct fib_rule_hdr *frh;
 894
 895	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
 896	if (nlh == NULL)
 897		return -EMSGSIZE;
 898
 899	frh = nlmsg_data(nlh);
 900	frh->family = ops->family;
 901	frh->table = rule->table;
 902	if (nla_put_u32(skb, FRA_TABLE, rule->table))
 903		goto nla_put_failure;
 904	if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
 905		goto nla_put_failure;
 906	frh->res1 = 0;
 907	frh->res2 = 0;
 908	frh->action = rule->action;
 909	frh->flags = rule->flags;
 910
 911	if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto))
 912		goto nla_put_failure;
 913
 914	if (rule->action == FR_ACT_GOTO &&
 915	    rcu_access_pointer(rule->ctarget) == NULL)
 916		frh->flags |= FIB_RULE_UNRESOLVED;
 917
 918	if (rule->iifname[0]) {
 919		if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
 920			goto nla_put_failure;
 921		if (rule->iifindex == -1)
 922			frh->flags |= FIB_RULE_IIF_DETACHED;
 923	}
 924
 925	if (rule->oifname[0]) {
 926		if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
 927			goto nla_put_failure;
 928		if (rule->oifindex == -1)
 929			frh->flags |= FIB_RULE_OIF_DETACHED;
 930	}
 931
 932	if ((rule->pref &&
 933	     nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
 934	    (rule->mark &&
 935	     nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
 936	    ((rule->mark_mask || rule->mark) &&
 937	     nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
 938	    (rule->target &&
 939	     nla_put_u32(skb, FRA_GOTO, rule->target)) ||
 940	    (rule->tun_id &&
 941	     nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) ||
 942	    (rule->l3mdev &&
 943	     nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) ||
 944	    (uid_range_set(&rule->uid_range) &&
 945	     nla_put_uid_range(skb, &rule->uid_range)) ||
 946	    (fib_rule_port_range_set(&rule->sport_range) &&
 947	     nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) ||
 948	    (fib_rule_port_range_set(&rule->dport_range) &&
 949	     nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) ||
 950	    (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto)))
 951		goto nla_put_failure;
 952
 953	if (rule->suppress_ifgroup != -1) {
 954		if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
 955			goto nla_put_failure;
 956	}
 957
 958	if (ops->fill(rule, skb, frh) < 0)
 959		goto nla_put_failure;
 960
 961	nlmsg_end(skb, nlh);
 962	return 0;
 963
 964nla_put_failure:
 965	nlmsg_cancel(skb, nlh);
 966	return -EMSGSIZE;
 967}
 968
 969static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
 970		      struct fib_rules_ops *ops)
 971{
 972	int idx = 0;
 973	struct fib_rule *rule;
 974	int err = 0;
 975
 976	rcu_read_lock();
 977	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
 978		if (idx < cb->args[1])
 979			goto skip;
 980
 981		err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
 982				       cb->nlh->nlmsg_seq, RTM_NEWRULE,
 983				       NLM_F_MULTI, ops);
 984		if (err)
 985			break;
 986skip:
 987		idx++;
 988	}
 989	rcu_read_unlock();
 990	cb->args[1] = idx;
 991	rules_ops_put(ops);
 992
 993	return err;
 994}
 995
 996static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
 997{
 998	struct net *net = sock_net(skb->sk);
 999	struct fib_rules_ops *ops;
1000	int idx = 0, family;
1001
1002	family = rtnl_msg_family(cb->nlh);
1003	if (family != AF_UNSPEC) {
1004		/* Protocol specific dump request */
1005		ops = lookup_rules_ops(net, family);
1006		if (ops == NULL)
1007			return -EAFNOSUPPORT;
1008
1009		dump_rules(skb, cb, ops);
1010
1011		return skb->len;
1012	}
1013
1014	rcu_read_lock();
1015	list_for_each_entry_rcu(ops, &net->rules_ops, list) {
1016		if (idx < cb->args[0] || !try_module_get(ops->owner))
1017			goto skip;
1018
1019		if (dump_rules(skb, cb, ops) < 0)
1020			break;
1021
1022		cb->args[1] = 0;
1023skip:
1024		idx++;
1025	}
1026	rcu_read_unlock();
1027	cb->args[0] = idx;
1028
1029	return skb->len;
1030}
1031
1032static void notify_rule_change(int event, struct fib_rule *rule,
1033			       struct fib_rules_ops *ops, struct nlmsghdr *nlh,
1034			       u32 pid)
1035{
1036	struct net *net;
1037	struct sk_buff *skb;
1038	int err = -ENOBUFS;
1039
1040	net = ops->fro_net;
1041	skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
1042	if (skb == NULL)
1043		goto errout;
1044
1045	err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
1046	if (err < 0) {
1047		/* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
1048		WARN_ON(err == -EMSGSIZE);
1049		kfree_skb(skb);
1050		goto errout;
1051	}
1052
1053	rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
1054	return;
1055errout:
1056	if (err < 0)
1057		rtnl_set_sk_err(net, ops->nlgroup, err);
1058}
1059
1060static void attach_rules(struct list_head *rules, struct net_device *dev)
1061{
1062	struct fib_rule *rule;
1063
1064	list_for_each_entry(rule, rules, list) {
1065		if (rule->iifindex == -1 &&
1066		    strcmp(dev->name, rule->iifname) == 0)
1067			rule->iifindex = dev->ifindex;
1068		if (rule->oifindex == -1 &&
1069		    strcmp(dev->name, rule->oifname) == 0)
1070			rule->oifindex = dev->ifindex;
1071	}
1072}
1073
1074static void detach_rules(struct list_head *rules, struct net_device *dev)
1075{
1076	struct fib_rule *rule;
1077
1078	list_for_each_entry(rule, rules, list) {
1079		if (rule->iifindex == dev->ifindex)
1080			rule->iifindex = -1;
1081		if (rule->oifindex == dev->ifindex)
1082			rule->oifindex = -1;
1083	}
1084}
1085
1086
1087static int fib_rules_event(struct notifier_block *this, unsigned long event,
1088			   void *ptr)
1089{
1090	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1091	struct net *net = dev_net(dev);
1092	struct fib_rules_ops *ops;
1093
1094	ASSERT_RTNL();
1095
1096	switch (event) {
1097	case NETDEV_REGISTER:
1098		list_for_each_entry(ops, &net->rules_ops, list)
1099			attach_rules(&ops->rules_list, dev);
1100		break;
1101
1102	case NETDEV_CHANGENAME:
1103		list_for_each_entry(ops, &net->rules_ops, list) {
1104			detach_rules(&ops->rules_list, dev);
1105			attach_rules(&ops->rules_list, dev);
1106		}
1107		break;
1108
1109	case NETDEV_UNREGISTER:
1110		list_for_each_entry(ops, &net->rules_ops, list)
1111			detach_rules(&ops->rules_list, dev);
1112		break;
1113	}
1114
1115	return NOTIFY_DONE;
1116}
1117
1118static struct notifier_block fib_rules_notifier = {
1119	.notifier_call = fib_rules_event,
1120};
1121
1122static int __net_init fib_rules_net_init(struct net *net)
1123{
1124	INIT_LIST_HEAD(&net->rules_ops);
1125	spin_lock_init(&net->rules_mod_lock);
1126	return 0;
1127}
1128
1129static void __net_exit fib_rules_net_exit(struct net *net)
1130{
1131	WARN_ON_ONCE(!list_empty(&net->rules_ops));
1132}
1133
1134static struct pernet_operations fib_rules_net_ops = {
1135	.init = fib_rules_net_init,
1136	.exit = fib_rules_net_exit,
1137};
1138
1139static int __init fib_rules_init(void)
1140{
1141	int err;
1142	rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, 0);
1143	rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, 0);
1144	rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, 0);
1145
1146	err = register_pernet_subsys(&fib_rules_net_ops);
1147	if (err < 0)
1148		goto fail;
1149
1150	err = register_netdevice_notifier(&fib_rules_notifier);
1151	if (err < 0)
1152		goto fail_unregister;
1153
1154	return 0;
1155
1156fail_unregister:
1157	unregister_pernet_subsys(&fib_rules_net_ops);
1158fail:
1159	rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
1160	rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
1161	rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
1162	return err;
1163}
1164
1165subsys_initcall(fib_rules_init);