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
 21int fib_default_rule_add(struct fib_rules_ops *ops,
 22			 u32 pref, u32 table, u32 flags)
 23{
 24	struct fib_rule *r;
 25
 26	r = kzalloc(ops->rule_size, GFP_KERNEL);
 27	if (r == NULL)
 28		return -ENOMEM;
 29
 30	atomic_set(&r->refcnt, 1);
 31	r->action = FR_ACT_TO_TBL;
 32	r->pref = pref;
 33	r->table = table;
 34	r->flags = flags;
 
 35	r->fr_net = ops->fro_net;
 
 36
 37	r->suppress_prefixlen = -1;
 38	r->suppress_ifgroup = -1;
 39
 40	/* The lock is not required here, the list in unreacheable
 41	 * at the moment this function is called */
 42	list_add_tail(&r->list, &ops->rules_list);
 43	return 0;
 44}
 45EXPORT_SYMBOL(fib_default_rule_add);
 46
 47static u32 fib_default_rule_pref(struct fib_rules_ops *ops)
 48{
 49	struct list_head *pos;
 50	struct fib_rule *rule;
 51
 52	if (!list_empty(&ops->rules_list)) {
 53		pos = ops->rules_list.next;
 54		if (pos->next != &ops->rules_list) {
 55			rule = list_entry(pos->next, struct fib_rule, list);
 56			if (rule->pref)
 57				return rule->pref - 1;
 58		}
 59	}
 60
 61	return 0;
 62}
 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	list_add_tail_rcu(&ops->list, &net->rules_ops);
120	err = 0;
121errout:
122	spin_unlock(&net->rules_mod_lock);
123
124	return err;
125}
126
127struct fib_rules_ops *
128fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net)
129{
130	struct fib_rules_ops *ops;
131	int err;
132
133	ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL);
134	if (ops == NULL)
135		return ERR_PTR(-ENOMEM);
136
137	INIT_LIST_HEAD(&ops->rules_list);
138	ops->fro_net = net;
139
140	err = __fib_rules_register(ops);
141	if (err) {
142		kfree(ops);
143		ops = ERR_PTR(err);
144	}
145
146	return ops;
147}
148EXPORT_SYMBOL_GPL(fib_rules_register);
149
150static void fib_rules_cleanup_ops(struct fib_rules_ops *ops)
151{
152	struct fib_rule *rule, *tmp;
153
154	list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) {
155		list_del_rcu(&rule->list);
156		if (ops->delete)
157			ops->delete(rule);
158		fib_rule_put(rule);
159	}
160}
161
162void fib_rules_unregister(struct fib_rules_ops *ops)
163{
164	struct net *net = ops->fro_net;
165
166	spin_lock(&net->rules_mod_lock);
167	list_del_rcu(&ops->list);
168	spin_unlock(&net->rules_mod_lock);
169
170	fib_rules_cleanup_ops(ops);
171	kfree_rcu(ops, rcu);
172}
173EXPORT_SYMBOL_GPL(fib_rules_unregister);
174
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
175static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops,
176			  struct flowi *fl, int flags)
 
177{
178	int ret = 0;
179
180	if (rule->iifindex && (rule->iifindex != fl->flowi_iif))
181		goto out;
182
183	if (rule->oifindex && (rule->oifindex != fl->flowi_oif))
184		goto out;
185
186	if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask)
187		goto out;
188
189	if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id))
190		goto out;
191
192	ret = ops->match(rule, fl, flags);
 
 
 
 
 
 
 
 
 
 
193out:
194	return (rule->flags & FIB_RULE_INVERT) ? !ret : ret;
195}
196
197int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl,
198		     int flags, struct fib_lookup_arg *arg)
199{
200	struct fib_rule *rule;
201	int err;
202
203	rcu_read_lock();
204
205	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
206jumped:
207		if (!fib_rule_match(rule, ops, fl, flags))
208			continue;
209
210		if (rule->action == FR_ACT_GOTO) {
211			struct fib_rule *target;
212
213			target = rcu_dereference(rule->ctarget);
214			if (target == NULL) {
215				continue;
216			} else {
217				rule = target;
218				goto jumped;
219			}
220		} else if (rule->action == FR_ACT_NOP)
221			continue;
222		else
223			err = ops->action(rule, fl, flags, arg);
224
225		if (!err && ops->suppress && ops->suppress(rule, arg))
 
 
 
 
 
 
226			continue;
227
228		if (err != -EAGAIN) {
229			if ((arg->flags & FIB_LOOKUP_NOREF) ||
230			    likely(atomic_inc_not_zero(&rule->refcnt))) {
231				arg->rule = rule;
232				goto out;
233			}
234			break;
235		}
236	}
237
238	err = -ESRCH;
239out:
240	rcu_read_unlock();
241
242	return err;
243}
244EXPORT_SYMBOL_GPL(fib_rules_lookup);
245
246static int validate_rulemsg(struct fib_rule_hdr *frh, struct nlattr **tb,
247			    struct fib_rules_ops *ops)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
248{
249	int err = -EINVAL;
250
251	if (frh->src_len)
252		if (tb[FRA_SRC] == NULL ||
253		    frh->src_len > (ops->addr_size * 8) ||
254		    nla_len(tb[FRA_SRC]) != ops->addr_size)
255			goto errout;
256
257	if (frh->dst_len)
258		if (tb[FRA_DST] == NULL ||
259		    frh->dst_len > (ops->addr_size * 8) ||
260		    nla_len(tb[FRA_DST]) != ops->addr_size)
261			goto errout;
 
 
 
 
 
262
263	err = 0;
264errout:
265	return err;
266}
 
267
268static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh)
269{
270	struct net *net = sock_net(skb->sk);
271	struct fib_rule_hdr *frh = nlmsg_data(nlh);
272	struct fib_rules_ops *ops = NULL;
273	struct fib_rule *rule, *r, *last = NULL;
274	struct nlattr *tb[FRA_MAX+1];
275	int err = -EINVAL, unresolved = 0;
276
277	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
278		goto errout;
279
280	ops = lookup_rules_ops(net, frh->family);
281	if (ops == NULL) {
282		err = -EAFNOSUPPORT;
283		goto errout;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
284	}
285
286	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
287	if (err < 0)
288		goto errout;
289
290	err = validate_rulemsg(frh, tb, ops);
291	if (err < 0)
292		goto errout;
 
 
 
 
 
 
293
294	rule = kzalloc(ops->rule_size, GFP_KERNEL);
295	if (rule == NULL) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
296		err = -ENOMEM;
297		goto errout;
298	}
299	rule->fr_net = net;
 
300
301	rule->pref = tb[FRA_PRIORITY] ? nla_get_u32(tb[FRA_PRIORITY])
302	                              : fib_default_rule_pref(ops);
 
 
 
 
 
 
 
303
304	if (tb[FRA_IIFNAME]) {
305		struct net_device *dev;
306
307		rule->iifindex = -1;
308		nla_strlcpy(rule->iifname, tb[FRA_IIFNAME], IFNAMSIZ);
309		dev = __dev_get_by_name(net, rule->iifname);
310		if (dev)
311			rule->iifindex = dev->ifindex;
312	}
313
314	if (tb[FRA_OIFNAME]) {
315		struct net_device *dev;
316
317		rule->oifindex = -1;
318		nla_strlcpy(rule->oifname, tb[FRA_OIFNAME], IFNAMSIZ);
319		dev = __dev_get_by_name(net, rule->oifname);
320		if (dev)
321			rule->oifindex = dev->ifindex;
322	}
323
324	if (tb[FRA_FWMARK]) {
325		rule->mark = nla_get_u32(tb[FRA_FWMARK]);
326		if (rule->mark)
327			/* compatibility: if the mark value is non-zero all bits
328			 * are compared unless a mask is explicitly specified.
329			 */
330			rule->mark_mask = 0xFFFFFFFF;
331	}
332
333	if (tb[FRA_FWMASK])
334		rule->mark_mask = nla_get_u32(tb[FRA_FWMASK]);
335
336	if (tb[FRA_TUN_ID])
337		rule->tun_id = nla_get_be64(tb[FRA_TUN_ID]);
338
339	rule->action = frh->action;
340	rule->flags = frh->flags;
341	rule->table = frh_get_table(frh, tb);
 
 
 
 
 
342	if (tb[FRA_SUPPRESS_PREFIXLEN])
343		rule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]);
344	else
345		rule->suppress_prefixlen = -1;
346
347	if (tb[FRA_SUPPRESS_IFGROUP])
348		rule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]);
349	else
350		rule->suppress_ifgroup = -1;
351
352	err = -EINVAL;
353	if (tb[FRA_GOTO]) {
354		if (rule->action != FR_ACT_GOTO)
 
355			goto errout_free;
 
356
357		rule->target = nla_get_u32(tb[FRA_GOTO]);
358		/* Backward jumps are prohibited to avoid endless loops */
359		if (rule->target <= rule->pref)
 
360			goto errout_free;
 
 
 
 
 
361
362		list_for_each_entry(r, &ops->rules_list, list) {
363			if (r->pref == rule->target) {
364				RCU_INIT_POINTER(rule->ctarget, r);
365				break;
366			}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
367		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
368
369		if (rcu_dereference_protected(rule->ctarget, 1) == NULL)
370			unresolved = 1;
371	} else if (rule->action == FR_ACT_GOTO)
372		goto errout_free;
373
374	err = ops->configure(rule, skb, frh, tb);
 
375	if (err < 0)
376		goto errout_free;
377
378	list_for_each_entry(r, &ops->rules_list, list) {
 
 
 
 
 
 
 
 
 
 
379		if (r->pref > rule->pref)
380			break;
381		last = r;
382	}
383
384	fib_rule_get(rule);
385
386	if (last)
387		list_add_rcu(&rule->list, &last->list);
388	else
389		list_add_rcu(&rule->list, &ops->rules_list);
390
391	if (ops->unresolved_rules) {
392		/*
393		 * There are unresolved goto rules in the list, check if
394		 * any of them are pointing to this new rule.
395		 */
396		list_for_each_entry(r, &ops->rules_list, list) {
397			if (r->action == FR_ACT_GOTO &&
398			    r->target == rule->pref &&
399			    rtnl_dereference(r->ctarget) == NULL) {
400				rcu_assign_pointer(r->ctarget, rule);
401				if (--ops->unresolved_rules == 0)
402					break;
403			}
404		}
405	}
406
407	if (rule->action == FR_ACT_GOTO)
408		ops->nr_goto_rules++;
409
410	if (unresolved)
411		ops->unresolved_rules++;
412
413	if (rule->tun_id)
414		ip_tunnel_need_metadata();
415
416	notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid);
417	flush_route_cache(ops);
418	rules_ops_put(ops);
419	return 0;
420
421errout_free:
422	kfree(rule);
423errout:
424	rules_ops_put(ops);
425	return err;
426}
 
427
428static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh)
 
429{
430	struct net *net = sock_net(skb->sk);
431	struct fib_rule_hdr *frh = nlmsg_data(nlh);
432	struct fib_rules_ops *ops = NULL;
433	struct fib_rule *rule, *tmp;
434	struct nlattr *tb[FRA_MAX+1];
435	int err = -EINVAL;
 
436
437	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh)))
 
438		goto errout;
 
439
440	ops = lookup_rules_ops(net, frh->family);
441	if (ops == NULL) {
442		err = -EAFNOSUPPORT;
 
443		goto errout;
444	}
445
446	err = nlmsg_parse(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy);
447	if (err < 0)
 
 
448		goto errout;
 
449
450	err = validate_rulemsg(frh, tb, ops);
451	if (err < 0)
452		goto errout;
453
454	list_for_each_entry(rule, &ops->rules_list, list) {
455		if (frh->action && (frh->action != rule->action))
456			continue;
457
458		if (frh_get_table(frh, tb) &&
459		    (frh_get_table(frh, tb) != rule->table))
460			continue;
461
462		if (tb[FRA_PRIORITY] &&
463		    (rule->pref != nla_get_u32(tb[FRA_PRIORITY])))
464			continue;
465
466		if (tb[FRA_IIFNAME] &&
467		    nla_strcmp(tb[FRA_IIFNAME], rule->iifname))
468			continue;
469
470		if (tb[FRA_OIFNAME] &&
471		    nla_strcmp(tb[FRA_OIFNAME], rule->oifname))
472			continue;
473
474		if (tb[FRA_FWMARK] &&
475		    (rule->mark != nla_get_u32(tb[FRA_FWMARK])))
476			continue;
477
478		if (tb[FRA_FWMASK] &&
479		    (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK])))
480			continue;
481
482		if (tb[FRA_TUN_ID] &&
483		    (rule->tun_id != nla_get_be64(tb[FRA_TUN_ID])))
484			continue;
485
486		if (!ops->compare(rule, frh, tb))
487			continue;
 
 
488
489		if (rule->flags & FIB_RULE_PERMANENT) {
490			err = -EPERM;
 
491			goto errout;
492		}
493
494		if (ops->delete) {
495			err = ops->delete(rule);
496			if (err)
497				goto errout;
498		}
499
500		if (rule->tun_id)
501			ip_tunnel_unneed_metadata();
502
503		list_del_rcu(&rule->list);
 
504
505		if (rule->action == FR_ACT_GOTO) {
506			ops->nr_goto_rules--;
507			if (rtnl_dereference(rule->ctarget) == NULL)
508				ops->unresolved_rules--;
509		}
510
511		/*
512		 * Check if this rule is a target to any of them. If so,
513		 * disable them. As this operation is eventually very
514		 * expensive, it is only performed if goto rules have
515		 * actually been added.
516		 */
517		if (ops->nr_goto_rules > 0) {
518			list_for_each_entry(tmp, &ops->rules_list, list) {
519				if (rtnl_dereference(tmp->ctarget) == rule) {
520					RCU_INIT_POINTER(tmp->ctarget, NULL);
521					ops->unresolved_rules++;
522				}
523			}
 
 
 
 
 
 
 
 
 
 
 
 
524		}
525
526		notify_rule_change(RTM_DELRULE, rule, ops, nlh,
527				   NETLINK_CB(skb).portid);
528		fib_rule_put(rule);
529		flush_route_cache(ops);
530		rules_ops_put(ops);
531		return 0;
532	}
533
534	err = -ENOENT;
 
 
 
 
 
 
 
 
 
535errout:
 
536	rules_ops_put(ops);
537	return err;
538}
 
539
540static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops,
541					 struct fib_rule *rule)
542{
543	size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr))
544			 + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */
545			 + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */
546			 + nla_total_size(4) /* FRA_PRIORITY */
547			 + nla_total_size(4) /* FRA_TABLE */
548			 + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */
549			 + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */
550			 + nla_total_size(4) /* FRA_FWMARK */
551			 + nla_total_size(4) /* FRA_FWMASK */
552			 + nla_total_size(8); /* FRA_TUN_ID */
 
 
 
 
 
553
554	if (ops->nlmsg_payload)
555		payload += ops->nlmsg_payload(rule);
556
557	return payload;
558}
559
560static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule,
561			    u32 pid, u32 seq, int type, int flags,
562			    struct fib_rules_ops *ops)
563{
564	struct nlmsghdr *nlh;
565	struct fib_rule_hdr *frh;
566
567	nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags);
568	if (nlh == NULL)
569		return -EMSGSIZE;
570
571	frh = nlmsg_data(nlh);
572	frh->family = ops->family;
573	frh->table = rule->table;
574	if (nla_put_u32(skb, FRA_TABLE, rule->table))
575		goto nla_put_failure;
576	if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen))
577		goto nla_put_failure;
578	frh->res1 = 0;
579	frh->res2 = 0;
580	frh->action = rule->action;
581	frh->flags = rule->flags;
582
 
 
 
583	if (rule->action == FR_ACT_GOTO &&
584	    rcu_access_pointer(rule->ctarget) == NULL)
585		frh->flags |= FIB_RULE_UNRESOLVED;
586
587	if (rule->iifname[0]) {
588		if (nla_put_string(skb, FRA_IIFNAME, rule->iifname))
589			goto nla_put_failure;
590		if (rule->iifindex == -1)
591			frh->flags |= FIB_RULE_IIF_DETACHED;
592	}
593
594	if (rule->oifname[0]) {
595		if (nla_put_string(skb, FRA_OIFNAME, rule->oifname))
596			goto nla_put_failure;
597		if (rule->oifindex == -1)
598			frh->flags |= FIB_RULE_OIF_DETACHED;
599	}
600
601	if ((rule->pref &&
602	     nla_put_u32(skb, FRA_PRIORITY, rule->pref)) ||
603	    (rule->mark &&
604	     nla_put_u32(skb, FRA_FWMARK, rule->mark)) ||
605	    ((rule->mark_mask || rule->mark) &&
606	     nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) ||
607	    (rule->target &&
608	     nla_put_u32(skb, FRA_GOTO, rule->target)) ||
609	    (rule->tun_id &&
610	     nla_put_be64(skb, FRA_TUN_ID, rule->tun_id)))
 
 
 
 
 
 
 
 
 
611		goto nla_put_failure;
612
613	if (rule->suppress_ifgroup != -1) {
614		if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup))
615			goto nla_put_failure;
616	}
617
618	if (ops->fill(rule, skb, frh) < 0)
619		goto nla_put_failure;
620
621	nlmsg_end(skb, nlh);
622	return 0;
623
624nla_put_failure:
625	nlmsg_cancel(skb, nlh);
626	return -EMSGSIZE;
627}
628
629static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb,
630		      struct fib_rules_ops *ops)
631{
632	int idx = 0;
633	struct fib_rule *rule;
634	int err = 0;
635
636	rcu_read_lock();
637	list_for_each_entry_rcu(rule, &ops->rules_list, list) {
638		if (idx < cb->args[1])
639			goto skip;
640
641		err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid,
642				       cb->nlh->nlmsg_seq, RTM_NEWRULE,
643				       NLM_F_MULTI, ops);
644		if (err)
645			break;
646skip:
647		idx++;
648	}
649	rcu_read_unlock();
650	cb->args[1] = idx;
651	rules_ops_put(ops);
652
653	return err;
654}
655
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
656static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb)
657{
 
658	struct net *net = sock_net(skb->sk);
659	struct fib_rules_ops *ops;
660	int idx = 0, family;
661
662	family = rtnl_msg_family(cb->nlh);
 
 
 
 
 
 
 
663	if (family != AF_UNSPEC) {
664		/* Protocol specific dump request */
665		ops = lookup_rules_ops(net, family);
666		if (ops == NULL)
667			return -EAFNOSUPPORT;
668
669		dump_rules(skb, cb, ops);
670
671		return skb->len;
672	}
673
674	rcu_read_lock();
675	list_for_each_entry_rcu(ops, &net->rules_ops, list) {
676		if (idx < cb->args[0] || !try_module_get(ops->owner))
677			goto skip;
678
679		if (dump_rules(skb, cb, ops) < 0)
680			break;
681
682		cb->args[1] = 0;
683skip:
684		idx++;
685	}
686	rcu_read_unlock();
687	cb->args[0] = idx;
688
689	return skb->len;
690}
691
692static void notify_rule_change(int event, struct fib_rule *rule,
693			       struct fib_rules_ops *ops, struct nlmsghdr *nlh,
694			       u32 pid)
695{
696	struct net *net;
697	struct sk_buff *skb;
698	int err = -ENOBUFS;
699
700	net = ops->fro_net;
701	skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL);
702	if (skb == NULL)
703		goto errout;
704
705	err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops);
706	if (err < 0) {
707		/* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */
708		WARN_ON(err == -EMSGSIZE);
709		kfree_skb(skb);
710		goto errout;
711	}
712
713	rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL);
714	return;
715errout:
716	if (err < 0)
717		rtnl_set_sk_err(net, ops->nlgroup, err);
718}
719
720static void attach_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 == -1 &&
726		    strcmp(dev->name, rule->iifname) == 0)
727			rule->iifindex = dev->ifindex;
728		if (rule->oifindex == -1 &&
729		    strcmp(dev->name, rule->oifname) == 0)
730			rule->oifindex = dev->ifindex;
731	}
732}
733
734static void detach_rules(struct list_head *rules, struct net_device *dev)
735{
736	struct fib_rule *rule;
737
738	list_for_each_entry(rule, rules, list) {
739		if (rule->iifindex == dev->ifindex)
740			rule->iifindex = -1;
741		if (rule->oifindex == dev->ifindex)
742			rule->oifindex = -1;
743	}
744}
745
746
747static int fib_rules_event(struct notifier_block *this, unsigned long event,
748			   void *ptr)
749{
750	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
751	struct net *net = dev_net(dev);
752	struct fib_rules_ops *ops;
753
754	ASSERT_RTNL();
755
756	switch (event) {
757	case NETDEV_REGISTER:
758		list_for_each_entry(ops, &net->rules_ops, list)
759			attach_rules(&ops->rules_list, dev);
760		break;
761
762	case NETDEV_CHANGENAME:
763		list_for_each_entry(ops, &net->rules_ops, list) {
764			detach_rules(&ops->rules_list, dev);
765			attach_rules(&ops->rules_list, dev);
766		}
767		break;
768
769	case NETDEV_UNREGISTER:
770		list_for_each_entry(ops, &net->rules_ops, list)
771			detach_rules(&ops->rules_list, dev);
772		break;
773	}
774
775	return NOTIFY_DONE;
776}
777
778static struct notifier_block fib_rules_notifier = {
779	.notifier_call = fib_rules_event,
780};
781
782static int __net_init fib_rules_net_init(struct net *net)
783{
784	INIT_LIST_HEAD(&net->rules_ops);
785	spin_lock_init(&net->rules_mod_lock);
786	return 0;
787}
788
 
 
 
 
 
789static struct pernet_operations fib_rules_net_ops = {
790	.init = fib_rules_net_init,
 
791};
792
793static int __init fib_rules_init(void)
794{
795	int err;
796	rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, NULL);
797	rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, NULL);
798	rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, NULL);
799
800	err = register_pernet_subsys(&fib_rules_net_ops);
801	if (err < 0)
802		goto fail;
803
804	err = register_netdevice_notifier(&fib_rules_notifier);
805	if (err < 0)
806		goto fail_unregister;
807
808	return 0;
809
810fail_unregister:
811	unregister_pernet_subsys(&fib_rules_net_ops);
812fail:
813	rtnl_unregister(PF_UNSPEC, RTM_NEWRULE);
814	rtnl_unregister(PF_UNSPEC, RTM_DELRULE);
815	rtnl_unregister(PF_UNSPEC, RTM_GETRULE);
816	return err;
817}
818
819subsys_initcall(fib_rules_init);