xref: /openbmc/linux/net/ipv4/ipmr.c (revision 8fdff1dc)
1 /*
2  *	IP multicast routing support for mrouted 3.6/3.8
3  *
4  *		(c) 1995 Alan Cox, <alan@lxorguk.ukuu.org.uk>
5  *	  Linux Consultancy and Custom Driver Development
6  *
7  *	This program is free software; you can redistribute it and/or
8  *	modify it under the terms of the GNU General Public License
9  *	as published by the Free Software Foundation; either version
10  *	2 of the License, or (at your option) any later version.
11  *
12  *	Fixes:
13  *	Michael Chastain	:	Incorrect size of copying.
14  *	Alan Cox		:	Added the cache manager code
15  *	Alan Cox		:	Fixed the clone/copy bug and device race.
16  *	Mike McLagan		:	Routing by source
17  *	Malcolm Beattie		:	Buffer handling fixes.
18  *	Alexey Kuznetsov	:	Double buffer free and other fixes.
19  *	SVR Anand		:	Fixed several multicast bugs and problems.
20  *	Alexey Kuznetsov	:	Status, optimisations and more.
21  *	Brad Parker		:	Better behaviour on mrouted upcall
22  *					overflow.
23  *      Carlos Picoto           :       PIMv1 Support
24  *	Pavlin Ivanov Radoslavov:	PIMv2 Registers must checksum only PIM header
25  *					Relax this requirement to work with older peers.
26  *
27  */
28 
29 #include <asm/uaccess.h>
30 #include <linux/types.h>
31 #include <linux/capability.h>
32 #include <linux/errno.h>
33 #include <linux/timer.h>
34 #include <linux/mm.h>
35 #include <linux/kernel.h>
36 #include <linux/fcntl.h>
37 #include <linux/stat.h>
38 #include <linux/socket.h>
39 #include <linux/in.h>
40 #include <linux/inet.h>
41 #include <linux/netdevice.h>
42 #include <linux/inetdevice.h>
43 #include <linux/igmp.h>
44 #include <linux/proc_fs.h>
45 #include <linux/seq_file.h>
46 #include <linux/mroute.h>
47 #include <linux/init.h>
48 #include <linux/if_ether.h>
49 #include <linux/slab.h>
50 #include <net/net_namespace.h>
51 #include <net/ip.h>
52 #include <net/protocol.h>
53 #include <linux/skbuff.h>
54 #include <net/route.h>
55 #include <net/sock.h>
56 #include <net/icmp.h>
57 #include <net/udp.h>
58 #include <net/raw.h>
59 #include <linux/notifier.h>
60 #include <linux/if_arp.h>
61 #include <linux/netfilter_ipv4.h>
62 #include <linux/compat.h>
63 #include <linux/export.h>
64 #include <net/ipip.h>
65 #include <net/checksum.h>
66 #include <net/netlink.h>
67 #include <net/fib_rules.h>
68 #include <linux/netconf.h>
69 
70 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
71 #define CONFIG_IP_PIMSM	1
72 #endif
73 
74 struct mr_table {
75 	struct list_head	list;
76 #ifdef CONFIG_NET_NS
77 	struct net		*net;
78 #endif
79 	u32			id;
80 	struct sock __rcu	*mroute_sk;
81 	struct timer_list	ipmr_expire_timer;
82 	struct list_head	mfc_unres_queue;
83 	struct list_head	mfc_cache_array[MFC_LINES];
84 	struct vif_device	vif_table[MAXVIFS];
85 	int			maxvif;
86 	atomic_t		cache_resolve_queue_len;
87 	bool			mroute_do_assert;
88 	bool			mroute_do_pim;
89 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
90 	int			mroute_reg_vif_num;
91 #endif
92 };
93 
94 struct ipmr_rule {
95 	struct fib_rule		common;
96 };
97 
98 struct ipmr_result {
99 	struct mr_table		*mrt;
100 };
101 
102 /* Big lock, protecting vif table, mrt cache and mroute socket state.
103  * Note that the changes are semaphored via rtnl_lock.
104  */
105 
106 static DEFINE_RWLOCK(mrt_lock);
107 
108 /*
109  *	Multicast router control variables
110  */
111 
112 #define VIF_EXISTS(_mrt, _idx) ((_mrt)->vif_table[_idx].dev != NULL)
113 
114 /* Special spinlock for queue of unresolved entries */
115 static DEFINE_SPINLOCK(mfc_unres_lock);
116 
117 /* We return to original Alan's scheme. Hash table of resolved
118  * entries is changed only in process context and protected
119  * with weak lock mrt_lock. Queue of unresolved entries is protected
120  * with strong spinlock mfc_unres_lock.
121  *
122  * In this case data path is free of exclusive locks at all.
123  */
124 
125 static struct kmem_cache *mrt_cachep __read_mostly;
126 
127 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
128 static void ipmr_free_table(struct mr_table *mrt);
129 
130 static int ip_mr_forward(struct net *net, struct mr_table *mrt,
131 			 struct sk_buff *skb, struct mfc_cache *cache,
132 			 int local);
133 static int ipmr_cache_report(struct mr_table *mrt,
134 			     struct sk_buff *pkt, vifi_t vifi, int assert);
135 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
136 			      struct mfc_cache *c, struct rtmsg *rtm);
137 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
138 				 int cmd);
139 static void mroute_clean_tables(struct mr_table *mrt);
140 static void ipmr_expire_process(unsigned long arg);
141 
142 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
143 #define ipmr_for_each_table(mrt, net) \
144 	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
145 
146 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
147 {
148 	struct mr_table *mrt;
149 
150 	ipmr_for_each_table(mrt, net) {
151 		if (mrt->id == id)
152 			return mrt;
153 	}
154 	return NULL;
155 }
156 
157 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
158 			   struct mr_table **mrt)
159 {
160 	struct ipmr_result res;
161 	struct fib_lookup_arg arg = { .result = &res, };
162 	int err;
163 
164 	err = fib_rules_lookup(net->ipv4.mr_rules_ops,
165 			       flowi4_to_flowi(flp4), 0, &arg);
166 	if (err < 0)
167 		return err;
168 	*mrt = res.mrt;
169 	return 0;
170 }
171 
172 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
173 			    int flags, struct fib_lookup_arg *arg)
174 {
175 	struct ipmr_result *res = arg->result;
176 	struct mr_table *mrt;
177 
178 	switch (rule->action) {
179 	case FR_ACT_TO_TBL:
180 		break;
181 	case FR_ACT_UNREACHABLE:
182 		return -ENETUNREACH;
183 	case FR_ACT_PROHIBIT:
184 		return -EACCES;
185 	case FR_ACT_BLACKHOLE:
186 	default:
187 		return -EINVAL;
188 	}
189 
190 	mrt = ipmr_get_table(rule->fr_net, rule->table);
191 	if (mrt == NULL)
192 		return -EAGAIN;
193 	res->mrt = mrt;
194 	return 0;
195 }
196 
197 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
198 {
199 	return 1;
200 }
201 
202 static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
203 	FRA_GENERIC_POLICY,
204 };
205 
206 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
207 			       struct fib_rule_hdr *frh, struct nlattr **tb)
208 {
209 	return 0;
210 }
211 
212 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
213 			     struct nlattr **tb)
214 {
215 	return 1;
216 }
217 
218 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
219 			  struct fib_rule_hdr *frh)
220 {
221 	frh->dst_len = 0;
222 	frh->src_len = 0;
223 	frh->tos     = 0;
224 	return 0;
225 }
226 
227 static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
228 	.family		= RTNL_FAMILY_IPMR,
229 	.rule_size	= sizeof(struct ipmr_rule),
230 	.addr_size	= sizeof(u32),
231 	.action		= ipmr_rule_action,
232 	.match		= ipmr_rule_match,
233 	.configure	= ipmr_rule_configure,
234 	.compare	= ipmr_rule_compare,
235 	.default_pref	= fib_default_rule_pref,
236 	.fill		= ipmr_rule_fill,
237 	.nlgroup	= RTNLGRP_IPV4_RULE,
238 	.policy		= ipmr_rule_policy,
239 	.owner		= THIS_MODULE,
240 };
241 
242 static int __net_init ipmr_rules_init(struct net *net)
243 {
244 	struct fib_rules_ops *ops;
245 	struct mr_table *mrt;
246 	int err;
247 
248 	ops = fib_rules_register(&ipmr_rules_ops_template, net);
249 	if (IS_ERR(ops))
250 		return PTR_ERR(ops);
251 
252 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
253 
254 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
255 	if (mrt == NULL) {
256 		err = -ENOMEM;
257 		goto err1;
258 	}
259 
260 	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
261 	if (err < 0)
262 		goto err2;
263 
264 	net->ipv4.mr_rules_ops = ops;
265 	return 0;
266 
267 err2:
268 	kfree(mrt);
269 err1:
270 	fib_rules_unregister(ops);
271 	return err;
272 }
273 
274 static void __net_exit ipmr_rules_exit(struct net *net)
275 {
276 	struct mr_table *mrt, *next;
277 
278 	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
279 		list_del(&mrt->list);
280 		ipmr_free_table(mrt);
281 	}
282 	fib_rules_unregister(net->ipv4.mr_rules_ops);
283 }
284 #else
285 #define ipmr_for_each_table(mrt, net) \
286 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
287 
288 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
289 {
290 	return net->ipv4.mrt;
291 }
292 
293 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
294 			   struct mr_table **mrt)
295 {
296 	*mrt = net->ipv4.mrt;
297 	return 0;
298 }
299 
300 static int __net_init ipmr_rules_init(struct net *net)
301 {
302 	net->ipv4.mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
303 	return net->ipv4.mrt ? 0 : -ENOMEM;
304 }
305 
306 static void __net_exit ipmr_rules_exit(struct net *net)
307 {
308 	ipmr_free_table(net->ipv4.mrt);
309 }
310 #endif
311 
312 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
313 {
314 	struct mr_table *mrt;
315 	unsigned int i;
316 
317 	mrt = ipmr_get_table(net, id);
318 	if (mrt != NULL)
319 		return mrt;
320 
321 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
322 	if (mrt == NULL)
323 		return NULL;
324 	write_pnet(&mrt->net, net);
325 	mrt->id = id;
326 
327 	/* Forwarding cache */
328 	for (i = 0; i < MFC_LINES; i++)
329 		INIT_LIST_HEAD(&mrt->mfc_cache_array[i]);
330 
331 	INIT_LIST_HEAD(&mrt->mfc_unres_queue);
332 
333 	setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
334 		    (unsigned long)mrt);
335 
336 #ifdef CONFIG_IP_PIMSM
337 	mrt->mroute_reg_vif_num = -1;
338 #endif
339 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
340 	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
341 #endif
342 	return mrt;
343 }
344 
345 static void ipmr_free_table(struct mr_table *mrt)
346 {
347 	del_timer_sync(&mrt->ipmr_expire_timer);
348 	mroute_clean_tables(mrt);
349 	kfree(mrt);
350 }
351 
352 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
353 
354 static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
355 {
356 	struct net *net = dev_net(dev);
357 
358 	dev_close(dev);
359 
360 	dev = __dev_get_by_name(net, "tunl0");
361 	if (dev) {
362 		const struct net_device_ops *ops = dev->netdev_ops;
363 		struct ifreq ifr;
364 		struct ip_tunnel_parm p;
365 
366 		memset(&p, 0, sizeof(p));
367 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
368 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
369 		p.iph.version = 4;
370 		p.iph.ihl = 5;
371 		p.iph.protocol = IPPROTO_IPIP;
372 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
373 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
374 
375 		if (ops->ndo_do_ioctl) {
376 			mm_segment_t oldfs = get_fs();
377 
378 			set_fs(KERNEL_DS);
379 			ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
380 			set_fs(oldfs);
381 		}
382 	}
383 }
384 
385 static
386 struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
387 {
388 	struct net_device  *dev;
389 
390 	dev = __dev_get_by_name(net, "tunl0");
391 
392 	if (dev) {
393 		const struct net_device_ops *ops = dev->netdev_ops;
394 		int err;
395 		struct ifreq ifr;
396 		struct ip_tunnel_parm p;
397 		struct in_device  *in_dev;
398 
399 		memset(&p, 0, sizeof(p));
400 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
401 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
402 		p.iph.version = 4;
403 		p.iph.ihl = 5;
404 		p.iph.protocol = IPPROTO_IPIP;
405 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
406 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
407 
408 		if (ops->ndo_do_ioctl) {
409 			mm_segment_t oldfs = get_fs();
410 
411 			set_fs(KERNEL_DS);
412 			err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
413 			set_fs(oldfs);
414 		} else {
415 			err = -EOPNOTSUPP;
416 		}
417 		dev = NULL;
418 
419 		if (err == 0 &&
420 		    (dev = __dev_get_by_name(net, p.name)) != NULL) {
421 			dev->flags |= IFF_MULTICAST;
422 
423 			in_dev = __in_dev_get_rtnl(dev);
424 			if (in_dev == NULL)
425 				goto failure;
426 
427 			ipv4_devconf_setall(in_dev);
428 			IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
429 
430 			if (dev_open(dev))
431 				goto failure;
432 			dev_hold(dev);
433 		}
434 	}
435 	return dev;
436 
437 failure:
438 	/* allow the register to be completed before unregistering. */
439 	rtnl_unlock();
440 	rtnl_lock();
441 
442 	unregister_netdevice(dev);
443 	return NULL;
444 }
445 
446 #ifdef CONFIG_IP_PIMSM
447 
448 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
449 {
450 	struct net *net = dev_net(dev);
451 	struct mr_table *mrt;
452 	struct flowi4 fl4 = {
453 		.flowi4_oif	= dev->ifindex,
454 		.flowi4_iif	= skb->skb_iif,
455 		.flowi4_mark	= skb->mark,
456 	};
457 	int err;
458 
459 	err = ipmr_fib_lookup(net, &fl4, &mrt);
460 	if (err < 0) {
461 		kfree_skb(skb);
462 		return err;
463 	}
464 
465 	read_lock(&mrt_lock);
466 	dev->stats.tx_bytes += skb->len;
467 	dev->stats.tx_packets++;
468 	ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
469 	read_unlock(&mrt_lock);
470 	kfree_skb(skb);
471 	return NETDEV_TX_OK;
472 }
473 
474 static const struct net_device_ops reg_vif_netdev_ops = {
475 	.ndo_start_xmit	= reg_vif_xmit,
476 };
477 
478 static void reg_vif_setup(struct net_device *dev)
479 {
480 	dev->type		= ARPHRD_PIMREG;
481 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
482 	dev->flags		= IFF_NOARP;
483 	dev->netdev_ops		= &reg_vif_netdev_ops,
484 	dev->destructor		= free_netdev;
485 	dev->features		|= NETIF_F_NETNS_LOCAL;
486 }
487 
488 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
489 {
490 	struct net_device *dev;
491 	struct in_device *in_dev;
492 	char name[IFNAMSIZ];
493 
494 	if (mrt->id == RT_TABLE_DEFAULT)
495 		sprintf(name, "pimreg");
496 	else
497 		sprintf(name, "pimreg%u", mrt->id);
498 
499 	dev = alloc_netdev(0, name, reg_vif_setup);
500 
501 	if (dev == NULL)
502 		return NULL;
503 
504 	dev_net_set(dev, net);
505 
506 	if (register_netdevice(dev)) {
507 		free_netdev(dev);
508 		return NULL;
509 	}
510 	dev->iflink = 0;
511 
512 	rcu_read_lock();
513 	in_dev = __in_dev_get_rcu(dev);
514 	if (!in_dev) {
515 		rcu_read_unlock();
516 		goto failure;
517 	}
518 
519 	ipv4_devconf_setall(in_dev);
520 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
521 	rcu_read_unlock();
522 
523 	if (dev_open(dev))
524 		goto failure;
525 
526 	dev_hold(dev);
527 
528 	return dev;
529 
530 failure:
531 	/* allow the register to be completed before unregistering. */
532 	rtnl_unlock();
533 	rtnl_lock();
534 
535 	unregister_netdevice(dev);
536 	return NULL;
537 }
538 #endif
539 
540 /**
541  *	vif_delete - Delete a VIF entry
542  *	@notify: Set to 1, if the caller is a notifier_call
543  */
544 
545 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
546 		      struct list_head *head)
547 {
548 	struct vif_device *v;
549 	struct net_device *dev;
550 	struct in_device *in_dev;
551 
552 	if (vifi < 0 || vifi >= mrt->maxvif)
553 		return -EADDRNOTAVAIL;
554 
555 	v = &mrt->vif_table[vifi];
556 
557 	write_lock_bh(&mrt_lock);
558 	dev = v->dev;
559 	v->dev = NULL;
560 
561 	if (!dev) {
562 		write_unlock_bh(&mrt_lock);
563 		return -EADDRNOTAVAIL;
564 	}
565 
566 #ifdef CONFIG_IP_PIMSM
567 	if (vifi == mrt->mroute_reg_vif_num)
568 		mrt->mroute_reg_vif_num = -1;
569 #endif
570 
571 	if (vifi + 1 == mrt->maxvif) {
572 		int tmp;
573 
574 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
575 			if (VIF_EXISTS(mrt, tmp))
576 				break;
577 		}
578 		mrt->maxvif = tmp+1;
579 	}
580 
581 	write_unlock_bh(&mrt_lock);
582 
583 	dev_set_allmulti(dev, -1);
584 
585 	in_dev = __in_dev_get_rtnl(dev);
586 	if (in_dev) {
587 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
588 		inet_netconf_notify_devconf(dev_net(dev),
589 					    NETCONFA_MC_FORWARDING,
590 					    dev->ifindex, &in_dev->cnf);
591 		ip_rt_multicast_event(in_dev);
592 	}
593 
594 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
595 		unregister_netdevice_queue(dev, head);
596 
597 	dev_put(dev);
598 	return 0;
599 }
600 
601 static void ipmr_cache_free_rcu(struct rcu_head *head)
602 {
603 	struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
604 
605 	kmem_cache_free(mrt_cachep, c);
606 }
607 
608 static inline void ipmr_cache_free(struct mfc_cache *c)
609 {
610 	call_rcu(&c->rcu, ipmr_cache_free_rcu);
611 }
612 
613 /* Destroy an unresolved cache entry, killing queued skbs
614  * and reporting error to netlink readers.
615  */
616 
617 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
618 {
619 	struct net *net = read_pnet(&mrt->net);
620 	struct sk_buff *skb;
621 	struct nlmsgerr *e;
622 
623 	atomic_dec(&mrt->cache_resolve_queue_len);
624 
625 	while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
626 		if (ip_hdr(skb)->version == 0) {
627 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
628 			nlh->nlmsg_type = NLMSG_ERROR;
629 			nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
630 			skb_trim(skb, nlh->nlmsg_len);
631 			e = NLMSG_DATA(nlh);
632 			e->error = -ETIMEDOUT;
633 			memset(&e->msg, 0, sizeof(e->msg));
634 
635 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
636 		} else {
637 			kfree_skb(skb);
638 		}
639 	}
640 
641 	ipmr_cache_free(c);
642 }
643 
644 
645 /* Timer process for the unresolved queue. */
646 
647 static void ipmr_expire_process(unsigned long arg)
648 {
649 	struct mr_table *mrt = (struct mr_table *)arg;
650 	unsigned long now;
651 	unsigned long expires;
652 	struct mfc_cache *c, *next;
653 
654 	if (!spin_trylock(&mfc_unres_lock)) {
655 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
656 		return;
657 	}
658 
659 	if (list_empty(&mrt->mfc_unres_queue))
660 		goto out;
661 
662 	now = jiffies;
663 	expires = 10*HZ;
664 
665 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
666 		if (time_after(c->mfc_un.unres.expires, now)) {
667 			unsigned long interval = c->mfc_un.unres.expires - now;
668 			if (interval < expires)
669 				expires = interval;
670 			continue;
671 		}
672 
673 		list_del(&c->list);
674 		mroute_netlink_event(mrt, c, RTM_DELROUTE);
675 		ipmr_destroy_unres(mrt, c);
676 	}
677 
678 	if (!list_empty(&mrt->mfc_unres_queue))
679 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
680 
681 out:
682 	spin_unlock(&mfc_unres_lock);
683 }
684 
685 /* Fill oifs list. It is called under write locked mrt_lock. */
686 
687 static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
688 				   unsigned char *ttls)
689 {
690 	int vifi;
691 
692 	cache->mfc_un.res.minvif = MAXVIFS;
693 	cache->mfc_un.res.maxvif = 0;
694 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
695 
696 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
697 		if (VIF_EXISTS(mrt, vifi) &&
698 		    ttls[vifi] && ttls[vifi] < 255) {
699 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
700 			if (cache->mfc_un.res.minvif > vifi)
701 				cache->mfc_un.res.minvif = vifi;
702 			if (cache->mfc_un.res.maxvif <= vifi)
703 				cache->mfc_un.res.maxvif = vifi + 1;
704 		}
705 	}
706 }
707 
708 static int vif_add(struct net *net, struct mr_table *mrt,
709 		   struct vifctl *vifc, int mrtsock)
710 {
711 	int vifi = vifc->vifc_vifi;
712 	struct vif_device *v = &mrt->vif_table[vifi];
713 	struct net_device *dev;
714 	struct in_device *in_dev;
715 	int err;
716 
717 	/* Is vif busy ? */
718 	if (VIF_EXISTS(mrt, vifi))
719 		return -EADDRINUSE;
720 
721 	switch (vifc->vifc_flags) {
722 #ifdef CONFIG_IP_PIMSM
723 	case VIFF_REGISTER:
724 		/*
725 		 * Special Purpose VIF in PIM
726 		 * All the packets will be sent to the daemon
727 		 */
728 		if (mrt->mroute_reg_vif_num >= 0)
729 			return -EADDRINUSE;
730 		dev = ipmr_reg_vif(net, mrt);
731 		if (!dev)
732 			return -ENOBUFS;
733 		err = dev_set_allmulti(dev, 1);
734 		if (err) {
735 			unregister_netdevice(dev);
736 			dev_put(dev);
737 			return err;
738 		}
739 		break;
740 #endif
741 	case VIFF_TUNNEL:
742 		dev = ipmr_new_tunnel(net, vifc);
743 		if (!dev)
744 			return -ENOBUFS;
745 		err = dev_set_allmulti(dev, 1);
746 		if (err) {
747 			ipmr_del_tunnel(dev, vifc);
748 			dev_put(dev);
749 			return err;
750 		}
751 		break;
752 
753 	case VIFF_USE_IFINDEX:
754 	case 0:
755 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
756 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
757 			if (dev && __in_dev_get_rtnl(dev) == NULL) {
758 				dev_put(dev);
759 				return -EADDRNOTAVAIL;
760 			}
761 		} else {
762 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
763 		}
764 		if (!dev)
765 			return -EADDRNOTAVAIL;
766 		err = dev_set_allmulti(dev, 1);
767 		if (err) {
768 			dev_put(dev);
769 			return err;
770 		}
771 		break;
772 	default:
773 		return -EINVAL;
774 	}
775 
776 	in_dev = __in_dev_get_rtnl(dev);
777 	if (!in_dev) {
778 		dev_put(dev);
779 		return -EADDRNOTAVAIL;
780 	}
781 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
782 	inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING, dev->ifindex,
783 				    &in_dev->cnf);
784 	ip_rt_multicast_event(in_dev);
785 
786 	/* Fill in the VIF structures */
787 
788 	v->rate_limit = vifc->vifc_rate_limit;
789 	v->local = vifc->vifc_lcl_addr.s_addr;
790 	v->remote = vifc->vifc_rmt_addr.s_addr;
791 	v->flags = vifc->vifc_flags;
792 	if (!mrtsock)
793 		v->flags |= VIFF_STATIC;
794 	v->threshold = vifc->vifc_threshold;
795 	v->bytes_in = 0;
796 	v->bytes_out = 0;
797 	v->pkt_in = 0;
798 	v->pkt_out = 0;
799 	v->link = dev->ifindex;
800 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
801 		v->link = dev->iflink;
802 
803 	/* And finish update writing critical data */
804 	write_lock_bh(&mrt_lock);
805 	v->dev = dev;
806 #ifdef CONFIG_IP_PIMSM
807 	if (v->flags & VIFF_REGISTER)
808 		mrt->mroute_reg_vif_num = vifi;
809 #endif
810 	if (vifi+1 > mrt->maxvif)
811 		mrt->maxvif = vifi+1;
812 	write_unlock_bh(&mrt_lock);
813 	return 0;
814 }
815 
816 /* called with rcu_read_lock() */
817 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
818 					 __be32 origin,
819 					 __be32 mcastgrp)
820 {
821 	int line = MFC_HASH(mcastgrp, origin);
822 	struct mfc_cache *c;
823 
824 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list) {
825 		if (c->mfc_origin == origin && c->mfc_mcastgrp == mcastgrp)
826 			return c;
827 	}
828 	return NULL;
829 }
830 
831 /*
832  *	Allocate a multicast cache entry
833  */
834 static struct mfc_cache *ipmr_cache_alloc(void)
835 {
836 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
837 
838 	if (c)
839 		c->mfc_un.res.minvif = MAXVIFS;
840 	return c;
841 }
842 
843 static struct mfc_cache *ipmr_cache_alloc_unres(void)
844 {
845 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
846 
847 	if (c) {
848 		skb_queue_head_init(&c->mfc_un.unres.unresolved);
849 		c->mfc_un.unres.expires = jiffies + 10*HZ;
850 	}
851 	return c;
852 }
853 
854 /*
855  *	A cache entry has gone into a resolved state from queued
856  */
857 
858 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
859 			       struct mfc_cache *uc, struct mfc_cache *c)
860 {
861 	struct sk_buff *skb;
862 	struct nlmsgerr *e;
863 
864 	/* Play the pending entries through our router */
865 
866 	while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
867 		if (ip_hdr(skb)->version == 0) {
868 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
869 
870 			if (__ipmr_fill_mroute(mrt, skb, c, NLMSG_DATA(nlh)) > 0) {
871 				nlh->nlmsg_len = skb_tail_pointer(skb) -
872 						 (u8 *)nlh;
873 			} else {
874 				nlh->nlmsg_type = NLMSG_ERROR;
875 				nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
876 				skb_trim(skb, nlh->nlmsg_len);
877 				e = NLMSG_DATA(nlh);
878 				e->error = -EMSGSIZE;
879 				memset(&e->msg, 0, sizeof(e->msg));
880 			}
881 
882 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
883 		} else {
884 			ip_mr_forward(net, mrt, skb, c, 0);
885 		}
886 	}
887 }
888 
889 /*
890  *	Bounce a cache query up to mrouted. We could use netlink for this but mrouted
891  *	expects the following bizarre scheme.
892  *
893  *	Called under mrt_lock.
894  */
895 
896 static int ipmr_cache_report(struct mr_table *mrt,
897 			     struct sk_buff *pkt, vifi_t vifi, int assert)
898 {
899 	struct sk_buff *skb;
900 	const int ihl = ip_hdrlen(pkt);
901 	struct igmphdr *igmp;
902 	struct igmpmsg *msg;
903 	struct sock *mroute_sk;
904 	int ret;
905 
906 #ifdef CONFIG_IP_PIMSM
907 	if (assert == IGMPMSG_WHOLEPKT)
908 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
909 	else
910 #endif
911 		skb = alloc_skb(128, GFP_ATOMIC);
912 
913 	if (!skb)
914 		return -ENOBUFS;
915 
916 #ifdef CONFIG_IP_PIMSM
917 	if (assert == IGMPMSG_WHOLEPKT) {
918 		/* Ugly, but we have no choice with this interface.
919 		 * Duplicate old header, fix ihl, length etc.
920 		 * And all this only to mangle msg->im_msgtype and
921 		 * to set msg->im_mbz to "mbz" :-)
922 		 */
923 		skb_push(skb, sizeof(struct iphdr));
924 		skb_reset_network_header(skb);
925 		skb_reset_transport_header(skb);
926 		msg = (struct igmpmsg *)skb_network_header(skb);
927 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
928 		msg->im_msgtype = IGMPMSG_WHOLEPKT;
929 		msg->im_mbz = 0;
930 		msg->im_vif = mrt->mroute_reg_vif_num;
931 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
932 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
933 					     sizeof(struct iphdr));
934 	} else
935 #endif
936 	{
937 
938 	/* Copy the IP header */
939 
940 	skb->network_header = skb->tail;
941 	skb_put(skb, ihl);
942 	skb_copy_to_linear_data(skb, pkt->data, ihl);
943 	ip_hdr(skb)->protocol = 0;	/* Flag to the kernel this is a route add */
944 	msg = (struct igmpmsg *)skb_network_header(skb);
945 	msg->im_vif = vifi;
946 	skb_dst_set(skb, dst_clone(skb_dst(pkt)));
947 
948 	/* Add our header */
949 
950 	igmp = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
951 	igmp->type	=
952 	msg->im_msgtype = assert;
953 	igmp->code	= 0;
954 	ip_hdr(skb)->tot_len = htons(skb->len);		/* Fix the length */
955 	skb->transport_header = skb->network_header;
956 	}
957 
958 	rcu_read_lock();
959 	mroute_sk = rcu_dereference(mrt->mroute_sk);
960 	if (mroute_sk == NULL) {
961 		rcu_read_unlock();
962 		kfree_skb(skb);
963 		return -EINVAL;
964 	}
965 
966 	/* Deliver to mrouted */
967 
968 	ret = sock_queue_rcv_skb(mroute_sk, skb);
969 	rcu_read_unlock();
970 	if (ret < 0) {
971 		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
972 		kfree_skb(skb);
973 	}
974 
975 	return ret;
976 }
977 
978 /*
979  *	Queue a packet for resolution. It gets locked cache entry!
980  */
981 
982 static int
983 ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi, struct sk_buff *skb)
984 {
985 	bool found = false;
986 	int err;
987 	struct mfc_cache *c;
988 	const struct iphdr *iph = ip_hdr(skb);
989 
990 	spin_lock_bh(&mfc_unres_lock);
991 	list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
992 		if (c->mfc_mcastgrp == iph->daddr &&
993 		    c->mfc_origin == iph->saddr) {
994 			found = true;
995 			break;
996 		}
997 	}
998 
999 	if (!found) {
1000 		/* Create a new entry if allowable */
1001 
1002 		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
1003 		    (c = ipmr_cache_alloc_unres()) == NULL) {
1004 			spin_unlock_bh(&mfc_unres_lock);
1005 
1006 			kfree_skb(skb);
1007 			return -ENOBUFS;
1008 		}
1009 
1010 		/* Fill in the new cache entry */
1011 
1012 		c->mfc_parent	= -1;
1013 		c->mfc_origin	= iph->saddr;
1014 		c->mfc_mcastgrp	= iph->daddr;
1015 
1016 		/* Reflect first query at mrouted. */
1017 
1018 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1019 		if (err < 0) {
1020 			/* If the report failed throw the cache entry
1021 			   out - Brad Parker
1022 			 */
1023 			spin_unlock_bh(&mfc_unres_lock);
1024 
1025 			ipmr_cache_free(c);
1026 			kfree_skb(skb);
1027 			return err;
1028 		}
1029 
1030 		atomic_inc(&mrt->cache_resolve_queue_len);
1031 		list_add(&c->list, &mrt->mfc_unres_queue);
1032 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1033 
1034 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1035 			mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1036 	}
1037 
1038 	/* See if we can append the packet */
1039 
1040 	if (c->mfc_un.unres.unresolved.qlen > 3) {
1041 		kfree_skb(skb);
1042 		err = -ENOBUFS;
1043 	} else {
1044 		skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1045 		err = 0;
1046 	}
1047 
1048 	spin_unlock_bh(&mfc_unres_lock);
1049 	return err;
1050 }
1051 
1052 /*
1053  *	MFC cache manipulation by user space mroute daemon
1054  */
1055 
1056 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc)
1057 {
1058 	int line;
1059 	struct mfc_cache *c, *next;
1060 
1061 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1062 
1063 	list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[line], list) {
1064 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1065 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
1066 			list_del_rcu(&c->list);
1067 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1068 			ipmr_cache_free(c);
1069 			return 0;
1070 		}
1071 	}
1072 	return -ENOENT;
1073 }
1074 
1075 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1076 			struct mfcctl *mfc, int mrtsock)
1077 {
1078 	bool found = false;
1079 	int line;
1080 	struct mfc_cache *uc, *c;
1081 
1082 	if (mfc->mfcc_parent >= MAXVIFS)
1083 		return -ENFILE;
1084 
1085 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1086 
1087 	list_for_each_entry(c, &mrt->mfc_cache_array[line], list) {
1088 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1089 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
1090 			found = true;
1091 			break;
1092 		}
1093 	}
1094 
1095 	if (found) {
1096 		write_lock_bh(&mrt_lock);
1097 		c->mfc_parent = mfc->mfcc_parent;
1098 		ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1099 		if (!mrtsock)
1100 			c->mfc_flags |= MFC_STATIC;
1101 		write_unlock_bh(&mrt_lock);
1102 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1103 		return 0;
1104 	}
1105 
1106 	if (!ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1107 		return -EINVAL;
1108 
1109 	c = ipmr_cache_alloc();
1110 	if (c == NULL)
1111 		return -ENOMEM;
1112 
1113 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1114 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1115 	c->mfc_parent = mfc->mfcc_parent;
1116 	ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1117 	if (!mrtsock)
1118 		c->mfc_flags |= MFC_STATIC;
1119 
1120 	list_add_rcu(&c->list, &mrt->mfc_cache_array[line]);
1121 
1122 	/*
1123 	 *	Check to see if we resolved a queued list. If so we
1124 	 *	need to send on the frames and tidy up.
1125 	 */
1126 	found = false;
1127 	spin_lock_bh(&mfc_unres_lock);
1128 	list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1129 		if (uc->mfc_origin == c->mfc_origin &&
1130 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1131 			list_del(&uc->list);
1132 			atomic_dec(&mrt->cache_resolve_queue_len);
1133 			found = true;
1134 			break;
1135 		}
1136 	}
1137 	if (list_empty(&mrt->mfc_unres_queue))
1138 		del_timer(&mrt->ipmr_expire_timer);
1139 	spin_unlock_bh(&mfc_unres_lock);
1140 
1141 	if (found) {
1142 		ipmr_cache_resolve(net, mrt, uc, c);
1143 		ipmr_cache_free(uc);
1144 	}
1145 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1146 	return 0;
1147 }
1148 
1149 /*
1150  *	Close the multicast socket, and clear the vif tables etc
1151  */
1152 
1153 static void mroute_clean_tables(struct mr_table *mrt)
1154 {
1155 	int i;
1156 	LIST_HEAD(list);
1157 	struct mfc_cache *c, *next;
1158 
1159 	/* Shut down all active vif entries */
1160 
1161 	for (i = 0; i < mrt->maxvif; i++) {
1162 		if (!(mrt->vif_table[i].flags & VIFF_STATIC))
1163 			vif_delete(mrt, i, 0, &list);
1164 	}
1165 	unregister_netdevice_many(&list);
1166 
1167 	/* Wipe the cache */
1168 
1169 	for (i = 0; i < MFC_LINES; i++) {
1170 		list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[i], list) {
1171 			if (c->mfc_flags & MFC_STATIC)
1172 				continue;
1173 			list_del_rcu(&c->list);
1174 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1175 			ipmr_cache_free(c);
1176 		}
1177 	}
1178 
1179 	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1180 		spin_lock_bh(&mfc_unres_lock);
1181 		list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
1182 			list_del(&c->list);
1183 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1184 			ipmr_destroy_unres(mrt, c);
1185 		}
1186 		spin_unlock_bh(&mfc_unres_lock);
1187 	}
1188 }
1189 
1190 /* called from ip_ra_control(), before an RCU grace period,
1191  * we dont need to call synchronize_rcu() here
1192  */
1193 static void mrtsock_destruct(struct sock *sk)
1194 {
1195 	struct net *net = sock_net(sk);
1196 	struct mr_table *mrt;
1197 
1198 	rtnl_lock();
1199 	ipmr_for_each_table(mrt, net) {
1200 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1201 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1202 			inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1203 						    NETCONFA_IFINDEX_ALL,
1204 						    net->ipv4.devconf_all);
1205 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1206 			mroute_clean_tables(mrt);
1207 		}
1208 	}
1209 	rtnl_unlock();
1210 }
1211 
1212 /*
1213  *	Socket options and virtual interface manipulation. The whole
1214  *	virtual interface system is a complete heap, but unfortunately
1215  *	that's how BSD mrouted happens to think. Maybe one day with a proper
1216  *	MOSPF/PIM router set up we can clean this up.
1217  */
1218 
1219 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen)
1220 {
1221 	int ret;
1222 	struct vifctl vif;
1223 	struct mfcctl mfc;
1224 	struct net *net = sock_net(sk);
1225 	struct mr_table *mrt;
1226 
1227 	if (sk->sk_type != SOCK_RAW ||
1228 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1229 		return -EOPNOTSUPP;
1230 
1231 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1232 	if (mrt == NULL)
1233 		return -ENOENT;
1234 
1235 	if (optname != MRT_INIT) {
1236 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1237 		    !ns_capable(net->user_ns, CAP_NET_ADMIN))
1238 			return -EACCES;
1239 	}
1240 
1241 	switch (optname) {
1242 	case MRT_INIT:
1243 		if (optlen != sizeof(int))
1244 			return -EINVAL;
1245 
1246 		rtnl_lock();
1247 		if (rtnl_dereference(mrt->mroute_sk)) {
1248 			rtnl_unlock();
1249 			return -EADDRINUSE;
1250 		}
1251 
1252 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1253 		if (ret == 0) {
1254 			rcu_assign_pointer(mrt->mroute_sk, sk);
1255 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1256 			inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1257 						    NETCONFA_IFINDEX_ALL,
1258 						    net->ipv4.devconf_all);
1259 		}
1260 		rtnl_unlock();
1261 		return ret;
1262 	case MRT_DONE:
1263 		if (sk != rcu_access_pointer(mrt->mroute_sk))
1264 			return -EACCES;
1265 		return ip_ra_control(sk, 0, NULL);
1266 	case MRT_ADD_VIF:
1267 	case MRT_DEL_VIF:
1268 		if (optlen != sizeof(vif))
1269 			return -EINVAL;
1270 		if (copy_from_user(&vif, optval, sizeof(vif)))
1271 			return -EFAULT;
1272 		if (vif.vifc_vifi >= MAXVIFS)
1273 			return -ENFILE;
1274 		rtnl_lock();
1275 		if (optname == MRT_ADD_VIF) {
1276 			ret = vif_add(net, mrt, &vif,
1277 				      sk == rtnl_dereference(mrt->mroute_sk));
1278 		} else {
1279 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1280 		}
1281 		rtnl_unlock();
1282 		return ret;
1283 
1284 		/*
1285 		 *	Manipulate the forwarding caches. These live
1286 		 *	in a sort of kernel/user symbiosis.
1287 		 */
1288 	case MRT_ADD_MFC:
1289 	case MRT_DEL_MFC:
1290 		if (optlen != sizeof(mfc))
1291 			return -EINVAL;
1292 		if (copy_from_user(&mfc, optval, sizeof(mfc)))
1293 			return -EFAULT;
1294 		rtnl_lock();
1295 		if (optname == MRT_DEL_MFC)
1296 			ret = ipmr_mfc_delete(mrt, &mfc);
1297 		else
1298 			ret = ipmr_mfc_add(net, mrt, &mfc,
1299 					   sk == rtnl_dereference(mrt->mroute_sk));
1300 		rtnl_unlock();
1301 		return ret;
1302 		/*
1303 		 *	Control PIM assert.
1304 		 */
1305 	case MRT_ASSERT:
1306 	{
1307 		int v;
1308 		if (optlen != sizeof(v))
1309 			return -EINVAL;
1310 		if (get_user(v, (int __user *)optval))
1311 			return -EFAULT;
1312 		mrt->mroute_do_assert = v;
1313 		return 0;
1314 	}
1315 #ifdef CONFIG_IP_PIMSM
1316 	case MRT_PIM:
1317 	{
1318 		int v;
1319 
1320 		if (optlen != sizeof(v))
1321 			return -EINVAL;
1322 		if (get_user(v, (int __user *)optval))
1323 			return -EFAULT;
1324 		v = !!v;
1325 
1326 		rtnl_lock();
1327 		ret = 0;
1328 		if (v != mrt->mroute_do_pim) {
1329 			mrt->mroute_do_pim = v;
1330 			mrt->mroute_do_assert = v;
1331 		}
1332 		rtnl_unlock();
1333 		return ret;
1334 	}
1335 #endif
1336 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
1337 	case MRT_TABLE:
1338 	{
1339 		u32 v;
1340 
1341 		if (optlen != sizeof(u32))
1342 			return -EINVAL;
1343 		if (get_user(v, (u32 __user *)optval))
1344 			return -EFAULT;
1345 
1346 		/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
1347 		if (v != RT_TABLE_DEFAULT && v >= 1000000000)
1348 			return -EINVAL;
1349 
1350 		rtnl_lock();
1351 		ret = 0;
1352 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1353 			ret = -EBUSY;
1354 		} else {
1355 			if (!ipmr_new_table(net, v))
1356 				ret = -ENOMEM;
1357 			else
1358 				raw_sk(sk)->ipmr_table = v;
1359 		}
1360 		rtnl_unlock();
1361 		return ret;
1362 	}
1363 #endif
1364 	/*
1365 	 *	Spurious command, or MRT_VERSION which you cannot
1366 	 *	set.
1367 	 */
1368 	default:
1369 		return -ENOPROTOOPT;
1370 	}
1371 }
1372 
1373 /*
1374  *	Getsock opt support for the multicast routing system.
1375  */
1376 
1377 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1378 {
1379 	int olr;
1380 	int val;
1381 	struct net *net = sock_net(sk);
1382 	struct mr_table *mrt;
1383 
1384 	if (sk->sk_type != SOCK_RAW ||
1385 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1386 		return -EOPNOTSUPP;
1387 
1388 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1389 	if (mrt == NULL)
1390 		return -ENOENT;
1391 
1392 	if (optname != MRT_VERSION &&
1393 #ifdef CONFIG_IP_PIMSM
1394 	   optname != MRT_PIM &&
1395 #endif
1396 	   optname != MRT_ASSERT)
1397 		return -ENOPROTOOPT;
1398 
1399 	if (get_user(olr, optlen))
1400 		return -EFAULT;
1401 
1402 	olr = min_t(unsigned int, olr, sizeof(int));
1403 	if (olr < 0)
1404 		return -EINVAL;
1405 
1406 	if (put_user(olr, optlen))
1407 		return -EFAULT;
1408 	if (optname == MRT_VERSION)
1409 		val = 0x0305;
1410 #ifdef CONFIG_IP_PIMSM
1411 	else if (optname == MRT_PIM)
1412 		val = mrt->mroute_do_pim;
1413 #endif
1414 	else
1415 		val = mrt->mroute_do_assert;
1416 	if (copy_to_user(optval, &val, olr))
1417 		return -EFAULT;
1418 	return 0;
1419 }
1420 
1421 /*
1422  *	The IP multicast ioctl support routines.
1423  */
1424 
1425 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1426 {
1427 	struct sioc_sg_req sr;
1428 	struct sioc_vif_req vr;
1429 	struct vif_device *vif;
1430 	struct mfc_cache *c;
1431 	struct net *net = sock_net(sk);
1432 	struct mr_table *mrt;
1433 
1434 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1435 	if (mrt == NULL)
1436 		return -ENOENT;
1437 
1438 	switch (cmd) {
1439 	case SIOCGETVIFCNT:
1440 		if (copy_from_user(&vr, arg, sizeof(vr)))
1441 			return -EFAULT;
1442 		if (vr.vifi >= mrt->maxvif)
1443 			return -EINVAL;
1444 		read_lock(&mrt_lock);
1445 		vif = &mrt->vif_table[vr.vifi];
1446 		if (VIF_EXISTS(mrt, vr.vifi)) {
1447 			vr.icount = vif->pkt_in;
1448 			vr.ocount = vif->pkt_out;
1449 			vr.ibytes = vif->bytes_in;
1450 			vr.obytes = vif->bytes_out;
1451 			read_unlock(&mrt_lock);
1452 
1453 			if (copy_to_user(arg, &vr, sizeof(vr)))
1454 				return -EFAULT;
1455 			return 0;
1456 		}
1457 		read_unlock(&mrt_lock);
1458 		return -EADDRNOTAVAIL;
1459 	case SIOCGETSGCNT:
1460 		if (copy_from_user(&sr, arg, sizeof(sr)))
1461 			return -EFAULT;
1462 
1463 		rcu_read_lock();
1464 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1465 		if (c) {
1466 			sr.pktcnt = c->mfc_un.res.pkt;
1467 			sr.bytecnt = c->mfc_un.res.bytes;
1468 			sr.wrong_if = c->mfc_un.res.wrong_if;
1469 			rcu_read_unlock();
1470 
1471 			if (copy_to_user(arg, &sr, sizeof(sr)))
1472 				return -EFAULT;
1473 			return 0;
1474 		}
1475 		rcu_read_unlock();
1476 		return -EADDRNOTAVAIL;
1477 	default:
1478 		return -ENOIOCTLCMD;
1479 	}
1480 }
1481 
1482 #ifdef CONFIG_COMPAT
1483 struct compat_sioc_sg_req {
1484 	struct in_addr src;
1485 	struct in_addr grp;
1486 	compat_ulong_t pktcnt;
1487 	compat_ulong_t bytecnt;
1488 	compat_ulong_t wrong_if;
1489 };
1490 
1491 struct compat_sioc_vif_req {
1492 	vifi_t	vifi;		/* Which iface */
1493 	compat_ulong_t icount;
1494 	compat_ulong_t ocount;
1495 	compat_ulong_t ibytes;
1496 	compat_ulong_t obytes;
1497 };
1498 
1499 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1500 {
1501 	struct compat_sioc_sg_req sr;
1502 	struct compat_sioc_vif_req vr;
1503 	struct vif_device *vif;
1504 	struct mfc_cache *c;
1505 	struct net *net = sock_net(sk);
1506 	struct mr_table *mrt;
1507 
1508 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1509 	if (mrt == NULL)
1510 		return -ENOENT;
1511 
1512 	switch (cmd) {
1513 	case SIOCGETVIFCNT:
1514 		if (copy_from_user(&vr, arg, sizeof(vr)))
1515 			return -EFAULT;
1516 		if (vr.vifi >= mrt->maxvif)
1517 			return -EINVAL;
1518 		read_lock(&mrt_lock);
1519 		vif = &mrt->vif_table[vr.vifi];
1520 		if (VIF_EXISTS(mrt, vr.vifi)) {
1521 			vr.icount = vif->pkt_in;
1522 			vr.ocount = vif->pkt_out;
1523 			vr.ibytes = vif->bytes_in;
1524 			vr.obytes = vif->bytes_out;
1525 			read_unlock(&mrt_lock);
1526 
1527 			if (copy_to_user(arg, &vr, sizeof(vr)))
1528 				return -EFAULT;
1529 			return 0;
1530 		}
1531 		read_unlock(&mrt_lock);
1532 		return -EADDRNOTAVAIL;
1533 	case SIOCGETSGCNT:
1534 		if (copy_from_user(&sr, arg, sizeof(sr)))
1535 			return -EFAULT;
1536 
1537 		rcu_read_lock();
1538 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1539 		if (c) {
1540 			sr.pktcnt = c->mfc_un.res.pkt;
1541 			sr.bytecnt = c->mfc_un.res.bytes;
1542 			sr.wrong_if = c->mfc_un.res.wrong_if;
1543 			rcu_read_unlock();
1544 
1545 			if (copy_to_user(arg, &sr, sizeof(sr)))
1546 				return -EFAULT;
1547 			return 0;
1548 		}
1549 		rcu_read_unlock();
1550 		return -EADDRNOTAVAIL;
1551 	default:
1552 		return -ENOIOCTLCMD;
1553 	}
1554 }
1555 #endif
1556 
1557 
1558 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1559 {
1560 	struct net_device *dev = ptr;
1561 	struct net *net = dev_net(dev);
1562 	struct mr_table *mrt;
1563 	struct vif_device *v;
1564 	int ct;
1565 
1566 	if (event != NETDEV_UNREGISTER)
1567 		return NOTIFY_DONE;
1568 
1569 	ipmr_for_each_table(mrt, net) {
1570 		v = &mrt->vif_table[0];
1571 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1572 			if (v->dev == dev)
1573 				vif_delete(mrt, ct, 1, NULL);
1574 		}
1575 	}
1576 	return NOTIFY_DONE;
1577 }
1578 
1579 
1580 static struct notifier_block ip_mr_notifier = {
1581 	.notifier_call = ipmr_device_event,
1582 };
1583 
1584 /*
1585  *	Encapsulate a packet by attaching a valid IPIP header to it.
1586  *	This avoids tunnel drivers and other mess and gives us the speed so
1587  *	important for multicast video.
1588  */
1589 
1590 static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr)
1591 {
1592 	struct iphdr *iph;
1593 	const struct iphdr *old_iph = ip_hdr(skb);
1594 
1595 	skb_push(skb, sizeof(struct iphdr));
1596 	skb->transport_header = skb->network_header;
1597 	skb_reset_network_header(skb);
1598 	iph = ip_hdr(skb);
1599 
1600 	iph->version	=	4;
1601 	iph->tos	=	old_iph->tos;
1602 	iph->ttl	=	old_iph->ttl;
1603 	iph->frag_off	=	0;
1604 	iph->daddr	=	daddr;
1605 	iph->saddr	=	saddr;
1606 	iph->protocol	=	IPPROTO_IPIP;
1607 	iph->ihl	=	5;
1608 	iph->tot_len	=	htons(skb->len);
1609 	ip_select_ident(iph, skb_dst(skb), NULL);
1610 	ip_send_check(iph);
1611 
1612 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1613 	nf_reset(skb);
1614 }
1615 
1616 static inline int ipmr_forward_finish(struct sk_buff *skb)
1617 {
1618 	struct ip_options *opt = &(IPCB(skb)->opt);
1619 
1620 	IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
1621 	IP_ADD_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTOCTETS, skb->len);
1622 
1623 	if (unlikely(opt->optlen))
1624 		ip_forward_options(skb);
1625 
1626 	return dst_output(skb);
1627 }
1628 
1629 /*
1630  *	Processing handlers for ipmr_forward
1631  */
1632 
1633 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1634 			    struct sk_buff *skb, struct mfc_cache *c, int vifi)
1635 {
1636 	const struct iphdr *iph = ip_hdr(skb);
1637 	struct vif_device *vif = &mrt->vif_table[vifi];
1638 	struct net_device *dev;
1639 	struct rtable *rt;
1640 	struct flowi4 fl4;
1641 	int    encap = 0;
1642 
1643 	if (vif->dev == NULL)
1644 		goto out_free;
1645 
1646 #ifdef CONFIG_IP_PIMSM
1647 	if (vif->flags & VIFF_REGISTER) {
1648 		vif->pkt_out++;
1649 		vif->bytes_out += skb->len;
1650 		vif->dev->stats.tx_bytes += skb->len;
1651 		vif->dev->stats.tx_packets++;
1652 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1653 		goto out_free;
1654 	}
1655 #endif
1656 
1657 	if (vif->flags & VIFF_TUNNEL) {
1658 		rt = ip_route_output_ports(net, &fl4, NULL,
1659 					   vif->remote, vif->local,
1660 					   0, 0,
1661 					   IPPROTO_IPIP,
1662 					   RT_TOS(iph->tos), vif->link);
1663 		if (IS_ERR(rt))
1664 			goto out_free;
1665 		encap = sizeof(struct iphdr);
1666 	} else {
1667 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1668 					   0, 0,
1669 					   IPPROTO_IPIP,
1670 					   RT_TOS(iph->tos), vif->link);
1671 		if (IS_ERR(rt))
1672 			goto out_free;
1673 	}
1674 
1675 	dev = rt->dst.dev;
1676 
1677 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1678 		/* Do not fragment multicasts. Alas, IPv4 does not
1679 		 * allow to send ICMP, so that packets will disappear
1680 		 * to blackhole.
1681 		 */
1682 
1683 		IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
1684 		ip_rt_put(rt);
1685 		goto out_free;
1686 	}
1687 
1688 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1689 
1690 	if (skb_cow(skb, encap)) {
1691 		ip_rt_put(rt);
1692 		goto out_free;
1693 	}
1694 
1695 	vif->pkt_out++;
1696 	vif->bytes_out += skb->len;
1697 
1698 	skb_dst_drop(skb);
1699 	skb_dst_set(skb, &rt->dst);
1700 	ip_decrease_ttl(ip_hdr(skb));
1701 
1702 	/* FIXME: forward and output firewalls used to be called here.
1703 	 * What do we do with netfilter? -- RR
1704 	 */
1705 	if (vif->flags & VIFF_TUNNEL) {
1706 		ip_encap(skb, vif->local, vif->remote);
1707 		/* FIXME: extra output firewall step used to be here. --RR */
1708 		vif->dev->stats.tx_packets++;
1709 		vif->dev->stats.tx_bytes += skb->len;
1710 	}
1711 
1712 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1713 
1714 	/*
1715 	 * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1716 	 * not only before forwarding, but after forwarding on all output
1717 	 * interfaces. It is clear, if mrouter runs a multicasting
1718 	 * program, it should receive packets not depending to what interface
1719 	 * program is joined.
1720 	 * If we will not make it, the program will have to join on all
1721 	 * interfaces. On the other hand, multihoming host (or router, but
1722 	 * not mrouter) cannot join to more than one interface - it will
1723 	 * result in receiving multiple packets.
1724 	 */
1725 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, skb, skb->dev, dev,
1726 		ipmr_forward_finish);
1727 	return;
1728 
1729 out_free:
1730 	kfree_skb(skb);
1731 }
1732 
1733 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1734 {
1735 	int ct;
1736 
1737 	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1738 		if (mrt->vif_table[ct].dev == dev)
1739 			break;
1740 	}
1741 	return ct;
1742 }
1743 
1744 /* "local" means that we should preserve one skb (for local delivery) */
1745 
1746 static int ip_mr_forward(struct net *net, struct mr_table *mrt,
1747 			 struct sk_buff *skb, struct mfc_cache *cache,
1748 			 int local)
1749 {
1750 	int psend = -1;
1751 	int vif, ct;
1752 
1753 	vif = cache->mfc_parent;
1754 	cache->mfc_un.res.pkt++;
1755 	cache->mfc_un.res.bytes += skb->len;
1756 
1757 	/*
1758 	 * Wrong interface: drop packet and (maybe) send PIM assert.
1759 	 */
1760 	if (mrt->vif_table[vif].dev != skb->dev) {
1761 		int true_vifi;
1762 
1763 		if (rt_is_output_route(skb_rtable(skb))) {
1764 			/* It is our own packet, looped back.
1765 			 * Very complicated situation...
1766 			 *
1767 			 * The best workaround until routing daemons will be
1768 			 * fixed is not to redistribute packet, if it was
1769 			 * send through wrong interface. It means, that
1770 			 * multicast applications WILL NOT work for
1771 			 * (S,G), which have default multicast route pointing
1772 			 * to wrong oif. In any case, it is not a good
1773 			 * idea to use multicasting applications on router.
1774 			 */
1775 			goto dont_forward;
1776 		}
1777 
1778 		cache->mfc_un.res.wrong_if++;
1779 		true_vifi = ipmr_find_vif(mrt, skb->dev);
1780 
1781 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
1782 		    /* pimsm uses asserts, when switching from RPT to SPT,
1783 		     * so that we cannot check that packet arrived on an oif.
1784 		     * It is bad, but otherwise we would need to move pretty
1785 		     * large chunk of pimd to kernel. Ough... --ANK
1786 		     */
1787 		    (mrt->mroute_do_pim ||
1788 		     cache->mfc_un.res.ttls[true_vifi] < 255) &&
1789 		    time_after(jiffies,
1790 			       cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1791 			cache->mfc_un.res.last_assert = jiffies;
1792 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1793 		}
1794 		goto dont_forward;
1795 	}
1796 
1797 	mrt->vif_table[vif].pkt_in++;
1798 	mrt->vif_table[vif].bytes_in += skb->len;
1799 
1800 	/*
1801 	 *	Forward the frame
1802 	 */
1803 	for (ct = cache->mfc_un.res.maxvif - 1;
1804 	     ct >= cache->mfc_un.res.minvif; ct--) {
1805 		if (ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1806 			if (psend != -1) {
1807 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1808 
1809 				if (skb2)
1810 					ipmr_queue_xmit(net, mrt, skb2, cache,
1811 							psend);
1812 			}
1813 			psend = ct;
1814 		}
1815 	}
1816 	if (psend != -1) {
1817 		if (local) {
1818 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1819 
1820 			if (skb2)
1821 				ipmr_queue_xmit(net, mrt, skb2, cache, psend);
1822 		} else {
1823 			ipmr_queue_xmit(net, mrt, skb, cache, psend);
1824 			return 0;
1825 		}
1826 	}
1827 
1828 dont_forward:
1829 	if (!local)
1830 		kfree_skb(skb);
1831 	return 0;
1832 }
1833 
1834 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
1835 {
1836 	struct rtable *rt = skb_rtable(skb);
1837 	struct iphdr *iph = ip_hdr(skb);
1838 	struct flowi4 fl4 = {
1839 		.daddr = iph->daddr,
1840 		.saddr = iph->saddr,
1841 		.flowi4_tos = RT_TOS(iph->tos),
1842 		.flowi4_oif = (rt_is_output_route(rt) ?
1843 			       skb->dev->ifindex : 0),
1844 		.flowi4_iif = (rt_is_output_route(rt) ?
1845 			       LOOPBACK_IFINDEX :
1846 			       skb->dev->ifindex),
1847 		.flowi4_mark = skb->mark,
1848 	};
1849 	struct mr_table *mrt;
1850 	int err;
1851 
1852 	err = ipmr_fib_lookup(net, &fl4, &mrt);
1853 	if (err)
1854 		return ERR_PTR(err);
1855 	return mrt;
1856 }
1857 
1858 /*
1859  *	Multicast packets for forwarding arrive here
1860  *	Called with rcu_read_lock();
1861  */
1862 
1863 int ip_mr_input(struct sk_buff *skb)
1864 {
1865 	struct mfc_cache *cache;
1866 	struct net *net = dev_net(skb->dev);
1867 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
1868 	struct mr_table *mrt;
1869 
1870 	/* Packet is looped back after forward, it should not be
1871 	 * forwarded second time, but still can be delivered locally.
1872 	 */
1873 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
1874 		goto dont_forward;
1875 
1876 	mrt = ipmr_rt_fib_lookup(net, skb);
1877 	if (IS_ERR(mrt)) {
1878 		kfree_skb(skb);
1879 		return PTR_ERR(mrt);
1880 	}
1881 	if (!local) {
1882 		if (IPCB(skb)->opt.router_alert) {
1883 			if (ip_call_ra_chain(skb))
1884 				return 0;
1885 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
1886 			/* IGMPv1 (and broken IGMPv2 implementations sort of
1887 			 * Cisco IOS <= 11.2(8)) do not put router alert
1888 			 * option to IGMP packets destined to routable
1889 			 * groups. It is very bad, because it means
1890 			 * that we can forward NO IGMP messages.
1891 			 */
1892 			struct sock *mroute_sk;
1893 
1894 			mroute_sk = rcu_dereference(mrt->mroute_sk);
1895 			if (mroute_sk) {
1896 				nf_reset(skb);
1897 				raw_rcv(mroute_sk, skb);
1898 				return 0;
1899 			}
1900 		    }
1901 	}
1902 
1903 	/* already under rcu_read_lock() */
1904 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
1905 
1906 	/*
1907 	 *	No usable cache entry
1908 	 */
1909 	if (cache == NULL) {
1910 		int vif;
1911 
1912 		if (local) {
1913 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1914 			ip_local_deliver(skb);
1915 			if (skb2 == NULL)
1916 				return -ENOBUFS;
1917 			skb = skb2;
1918 		}
1919 
1920 		read_lock(&mrt_lock);
1921 		vif = ipmr_find_vif(mrt, skb->dev);
1922 		if (vif >= 0) {
1923 			int err2 = ipmr_cache_unresolved(mrt, vif, skb);
1924 			read_unlock(&mrt_lock);
1925 
1926 			return err2;
1927 		}
1928 		read_unlock(&mrt_lock);
1929 		kfree_skb(skb);
1930 		return -ENODEV;
1931 	}
1932 
1933 	read_lock(&mrt_lock);
1934 	ip_mr_forward(net, mrt, skb, cache, local);
1935 	read_unlock(&mrt_lock);
1936 
1937 	if (local)
1938 		return ip_local_deliver(skb);
1939 
1940 	return 0;
1941 
1942 dont_forward:
1943 	if (local)
1944 		return ip_local_deliver(skb);
1945 	kfree_skb(skb);
1946 	return 0;
1947 }
1948 
1949 #ifdef CONFIG_IP_PIMSM
1950 /* called with rcu_read_lock() */
1951 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
1952 		     unsigned int pimlen)
1953 {
1954 	struct net_device *reg_dev = NULL;
1955 	struct iphdr *encap;
1956 
1957 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
1958 	/*
1959 	 * Check that:
1960 	 * a. packet is really sent to a multicast group
1961 	 * b. packet is not a NULL-REGISTER
1962 	 * c. packet is not truncated
1963 	 */
1964 	if (!ipv4_is_multicast(encap->daddr) ||
1965 	    encap->tot_len == 0 ||
1966 	    ntohs(encap->tot_len) + pimlen > skb->len)
1967 		return 1;
1968 
1969 	read_lock(&mrt_lock);
1970 	if (mrt->mroute_reg_vif_num >= 0)
1971 		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
1972 	read_unlock(&mrt_lock);
1973 
1974 	if (reg_dev == NULL)
1975 		return 1;
1976 
1977 	skb->mac_header = skb->network_header;
1978 	skb_pull(skb, (u8 *)encap - skb->data);
1979 	skb_reset_network_header(skb);
1980 	skb->protocol = htons(ETH_P_IP);
1981 	skb->ip_summed = CHECKSUM_NONE;
1982 	skb->pkt_type = PACKET_HOST;
1983 
1984 	skb_tunnel_rx(skb, reg_dev);
1985 
1986 	netif_rx(skb);
1987 
1988 	return NET_RX_SUCCESS;
1989 }
1990 #endif
1991 
1992 #ifdef CONFIG_IP_PIMSM_V1
1993 /*
1994  * Handle IGMP messages of PIMv1
1995  */
1996 
1997 int pim_rcv_v1(struct sk_buff *skb)
1998 {
1999 	struct igmphdr *pim;
2000 	struct net *net = dev_net(skb->dev);
2001 	struct mr_table *mrt;
2002 
2003 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2004 		goto drop;
2005 
2006 	pim = igmp_hdr(skb);
2007 
2008 	mrt = ipmr_rt_fib_lookup(net, skb);
2009 	if (IS_ERR(mrt))
2010 		goto drop;
2011 	if (!mrt->mroute_do_pim ||
2012 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2013 		goto drop;
2014 
2015 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2016 drop:
2017 		kfree_skb(skb);
2018 	}
2019 	return 0;
2020 }
2021 #endif
2022 
2023 #ifdef CONFIG_IP_PIMSM_V2
2024 static int pim_rcv(struct sk_buff *skb)
2025 {
2026 	struct pimreghdr *pim;
2027 	struct net *net = dev_net(skb->dev);
2028 	struct mr_table *mrt;
2029 
2030 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2031 		goto drop;
2032 
2033 	pim = (struct pimreghdr *)skb_transport_header(skb);
2034 	if (pim->type != ((PIM_VERSION << 4) | (PIM_REGISTER)) ||
2035 	    (pim->flags & PIM_NULL_REGISTER) ||
2036 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2037 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2038 		goto drop;
2039 
2040 	mrt = ipmr_rt_fib_lookup(net, skb);
2041 	if (IS_ERR(mrt))
2042 		goto drop;
2043 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2044 drop:
2045 		kfree_skb(skb);
2046 	}
2047 	return 0;
2048 }
2049 #endif
2050 
2051 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2052 			      struct mfc_cache *c, struct rtmsg *rtm)
2053 {
2054 	int ct;
2055 	struct rtnexthop *nhp;
2056 	struct nlattr *mp_attr;
2057 	struct rta_mfc_stats mfcs;
2058 
2059 	/* If cache is unresolved, don't try to parse IIF and OIF */
2060 	if (c->mfc_parent >= MAXVIFS)
2061 		return -ENOENT;
2062 
2063 	if (VIF_EXISTS(mrt, c->mfc_parent) &&
2064 	    nla_put_u32(skb, RTA_IIF, mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
2065 		return -EMSGSIZE;
2066 
2067 	if (!(mp_attr = nla_nest_start(skb, RTA_MULTIPATH)))
2068 		return -EMSGSIZE;
2069 
2070 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
2071 		if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
2072 			if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp)))) {
2073 				nla_nest_cancel(skb, mp_attr);
2074 				return -EMSGSIZE;
2075 			}
2076 
2077 			nhp->rtnh_flags = 0;
2078 			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
2079 			nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
2080 			nhp->rtnh_len = sizeof(*nhp);
2081 		}
2082 	}
2083 
2084 	nla_nest_end(skb, mp_attr);
2085 
2086 	mfcs.mfcs_packets = c->mfc_un.res.pkt;
2087 	mfcs.mfcs_bytes = c->mfc_un.res.bytes;
2088 	mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
2089 	if (nla_put(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs) < 0)
2090 		return -EMSGSIZE;
2091 
2092 	rtm->rtm_type = RTN_MULTICAST;
2093 	return 1;
2094 }
2095 
2096 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2097 		   __be32 saddr, __be32 daddr,
2098 		   struct rtmsg *rtm, int nowait)
2099 {
2100 	struct mfc_cache *cache;
2101 	struct mr_table *mrt;
2102 	int err;
2103 
2104 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2105 	if (mrt == NULL)
2106 		return -ENOENT;
2107 
2108 	rcu_read_lock();
2109 	cache = ipmr_cache_find(mrt, saddr, daddr);
2110 
2111 	if (cache == NULL) {
2112 		struct sk_buff *skb2;
2113 		struct iphdr *iph;
2114 		struct net_device *dev;
2115 		int vif = -1;
2116 
2117 		if (nowait) {
2118 			rcu_read_unlock();
2119 			return -EAGAIN;
2120 		}
2121 
2122 		dev = skb->dev;
2123 		read_lock(&mrt_lock);
2124 		if (dev)
2125 			vif = ipmr_find_vif(mrt, dev);
2126 		if (vif < 0) {
2127 			read_unlock(&mrt_lock);
2128 			rcu_read_unlock();
2129 			return -ENODEV;
2130 		}
2131 		skb2 = skb_clone(skb, GFP_ATOMIC);
2132 		if (!skb2) {
2133 			read_unlock(&mrt_lock);
2134 			rcu_read_unlock();
2135 			return -ENOMEM;
2136 		}
2137 
2138 		skb_push(skb2, sizeof(struct iphdr));
2139 		skb_reset_network_header(skb2);
2140 		iph = ip_hdr(skb2);
2141 		iph->ihl = sizeof(struct iphdr) >> 2;
2142 		iph->saddr = saddr;
2143 		iph->daddr = daddr;
2144 		iph->version = 0;
2145 		err = ipmr_cache_unresolved(mrt, vif, skb2);
2146 		read_unlock(&mrt_lock);
2147 		rcu_read_unlock();
2148 		return err;
2149 	}
2150 
2151 	read_lock(&mrt_lock);
2152 	if (!nowait && (rtm->rtm_flags & RTM_F_NOTIFY))
2153 		cache->mfc_flags |= MFC_NOTIFY;
2154 	err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2155 	read_unlock(&mrt_lock);
2156 	rcu_read_unlock();
2157 	return err;
2158 }
2159 
2160 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2161 			    u32 portid, u32 seq, struct mfc_cache *c, int cmd)
2162 {
2163 	struct nlmsghdr *nlh;
2164 	struct rtmsg *rtm;
2165 	int err;
2166 
2167 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), NLM_F_MULTI);
2168 	if (nlh == NULL)
2169 		return -EMSGSIZE;
2170 
2171 	rtm = nlmsg_data(nlh);
2172 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2173 	rtm->rtm_dst_len  = 32;
2174 	rtm->rtm_src_len  = 32;
2175 	rtm->rtm_tos      = 0;
2176 	rtm->rtm_table    = mrt->id;
2177 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2178 		goto nla_put_failure;
2179 	rtm->rtm_type     = RTN_MULTICAST;
2180 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2181 	if (c->mfc_flags & MFC_STATIC)
2182 		rtm->rtm_protocol = RTPROT_STATIC;
2183 	else
2184 		rtm->rtm_protocol = RTPROT_MROUTED;
2185 	rtm->rtm_flags    = 0;
2186 
2187 	if (nla_put_be32(skb, RTA_SRC, c->mfc_origin) ||
2188 	    nla_put_be32(skb, RTA_DST, c->mfc_mcastgrp))
2189 		goto nla_put_failure;
2190 	err = __ipmr_fill_mroute(mrt, skb, c, rtm);
2191 	/* do not break the dump if cache is unresolved */
2192 	if (err < 0 && err != -ENOENT)
2193 		goto nla_put_failure;
2194 
2195 	return nlmsg_end(skb, nlh);
2196 
2197 nla_put_failure:
2198 	nlmsg_cancel(skb, nlh);
2199 	return -EMSGSIZE;
2200 }
2201 
2202 static size_t mroute_msgsize(bool unresolved, int maxvif)
2203 {
2204 	size_t len =
2205 		NLMSG_ALIGN(sizeof(struct rtmsg))
2206 		+ nla_total_size(4)	/* RTA_TABLE */
2207 		+ nla_total_size(4)	/* RTA_SRC */
2208 		+ nla_total_size(4)	/* RTA_DST */
2209 		;
2210 
2211 	if (!unresolved)
2212 		len = len
2213 		      + nla_total_size(4)	/* RTA_IIF */
2214 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2215 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2216 						/* RTA_MFC_STATS */
2217 		      + nla_total_size(sizeof(struct rta_mfc_stats))
2218 		;
2219 
2220 	return len;
2221 }
2222 
2223 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2224 				 int cmd)
2225 {
2226 	struct net *net = read_pnet(&mrt->net);
2227 	struct sk_buff *skb;
2228 	int err = -ENOBUFS;
2229 
2230 	skb = nlmsg_new(mroute_msgsize(mfc->mfc_parent >= MAXVIFS, mrt->maxvif),
2231 			GFP_ATOMIC);
2232 	if (skb == NULL)
2233 		goto errout;
2234 
2235 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd);
2236 	if (err < 0)
2237 		goto errout;
2238 
2239 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2240 	return;
2241 
2242 errout:
2243 	kfree_skb(skb);
2244 	if (err < 0)
2245 		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2246 }
2247 
2248 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2249 {
2250 	struct net *net = sock_net(skb->sk);
2251 	struct mr_table *mrt;
2252 	struct mfc_cache *mfc;
2253 	unsigned int t = 0, s_t;
2254 	unsigned int h = 0, s_h;
2255 	unsigned int e = 0, s_e;
2256 
2257 	s_t = cb->args[0];
2258 	s_h = cb->args[1];
2259 	s_e = cb->args[2];
2260 
2261 	rcu_read_lock();
2262 	ipmr_for_each_table(mrt, net) {
2263 		if (t < s_t)
2264 			goto next_table;
2265 		if (t > s_t)
2266 			s_h = 0;
2267 		for (h = s_h; h < MFC_LINES; h++) {
2268 			list_for_each_entry_rcu(mfc, &mrt->mfc_cache_array[h], list) {
2269 				if (e < s_e)
2270 					goto next_entry;
2271 				if (ipmr_fill_mroute(mrt, skb,
2272 						     NETLINK_CB(cb->skb).portid,
2273 						     cb->nlh->nlmsg_seq,
2274 						     mfc, RTM_NEWROUTE) < 0)
2275 					goto done;
2276 next_entry:
2277 				e++;
2278 			}
2279 			e = s_e = 0;
2280 		}
2281 		spin_lock_bh(&mfc_unres_lock);
2282 		list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
2283 			if (e < s_e)
2284 				goto next_entry2;
2285 			if (ipmr_fill_mroute(mrt, skb,
2286 					     NETLINK_CB(cb->skb).portid,
2287 					     cb->nlh->nlmsg_seq,
2288 					     mfc, RTM_NEWROUTE) < 0) {
2289 				spin_unlock_bh(&mfc_unres_lock);
2290 				goto done;
2291 			}
2292 next_entry2:
2293 			e++;
2294 		}
2295 		spin_unlock_bh(&mfc_unres_lock);
2296 		e = s_e = 0;
2297 		s_h = 0;
2298 next_table:
2299 		t++;
2300 	}
2301 done:
2302 	rcu_read_unlock();
2303 
2304 	cb->args[2] = e;
2305 	cb->args[1] = h;
2306 	cb->args[0] = t;
2307 
2308 	return skb->len;
2309 }
2310 
2311 #ifdef CONFIG_PROC_FS
2312 /*
2313  *	The /proc interfaces to multicast routing :
2314  *	/proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2315  */
2316 struct ipmr_vif_iter {
2317 	struct seq_net_private p;
2318 	struct mr_table *mrt;
2319 	int ct;
2320 };
2321 
2322 static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2323 					   struct ipmr_vif_iter *iter,
2324 					   loff_t pos)
2325 {
2326 	struct mr_table *mrt = iter->mrt;
2327 
2328 	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2329 		if (!VIF_EXISTS(mrt, iter->ct))
2330 			continue;
2331 		if (pos-- == 0)
2332 			return &mrt->vif_table[iter->ct];
2333 	}
2334 	return NULL;
2335 }
2336 
2337 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2338 	__acquires(mrt_lock)
2339 {
2340 	struct ipmr_vif_iter *iter = seq->private;
2341 	struct net *net = seq_file_net(seq);
2342 	struct mr_table *mrt;
2343 
2344 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2345 	if (mrt == NULL)
2346 		return ERR_PTR(-ENOENT);
2347 
2348 	iter->mrt = mrt;
2349 
2350 	read_lock(&mrt_lock);
2351 	return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2352 		: SEQ_START_TOKEN;
2353 }
2354 
2355 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2356 {
2357 	struct ipmr_vif_iter *iter = seq->private;
2358 	struct net *net = seq_file_net(seq);
2359 	struct mr_table *mrt = iter->mrt;
2360 
2361 	++*pos;
2362 	if (v == SEQ_START_TOKEN)
2363 		return ipmr_vif_seq_idx(net, iter, 0);
2364 
2365 	while (++iter->ct < mrt->maxvif) {
2366 		if (!VIF_EXISTS(mrt, iter->ct))
2367 			continue;
2368 		return &mrt->vif_table[iter->ct];
2369 	}
2370 	return NULL;
2371 }
2372 
2373 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2374 	__releases(mrt_lock)
2375 {
2376 	read_unlock(&mrt_lock);
2377 }
2378 
2379 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2380 {
2381 	struct ipmr_vif_iter *iter = seq->private;
2382 	struct mr_table *mrt = iter->mrt;
2383 
2384 	if (v == SEQ_START_TOKEN) {
2385 		seq_puts(seq,
2386 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2387 	} else {
2388 		const struct vif_device *vif = v;
2389 		const char *name =  vif->dev ? vif->dev->name : "none";
2390 
2391 		seq_printf(seq,
2392 			   "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2393 			   vif - mrt->vif_table,
2394 			   name, vif->bytes_in, vif->pkt_in,
2395 			   vif->bytes_out, vif->pkt_out,
2396 			   vif->flags, vif->local, vif->remote);
2397 	}
2398 	return 0;
2399 }
2400 
2401 static const struct seq_operations ipmr_vif_seq_ops = {
2402 	.start = ipmr_vif_seq_start,
2403 	.next  = ipmr_vif_seq_next,
2404 	.stop  = ipmr_vif_seq_stop,
2405 	.show  = ipmr_vif_seq_show,
2406 };
2407 
2408 static int ipmr_vif_open(struct inode *inode, struct file *file)
2409 {
2410 	return seq_open_net(inode, file, &ipmr_vif_seq_ops,
2411 			    sizeof(struct ipmr_vif_iter));
2412 }
2413 
2414 static const struct file_operations ipmr_vif_fops = {
2415 	.owner	 = THIS_MODULE,
2416 	.open    = ipmr_vif_open,
2417 	.read    = seq_read,
2418 	.llseek  = seq_lseek,
2419 	.release = seq_release_net,
2420 };
2421 
2422 struct ipmr_mfc_iter {
2423 	struct seq_net_private p;
2424 	struct mr_table *mrt;
2425 	struct list_head *cache;
2426 	int ct;
2427 };
2428 
2429 
2430 static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
2431 					  struct ipmr_mfc_iter *it, loff_t pos)
2432 {
2433 	struct mr_table *mrt = it->mrt;
2434 	struct mfc_cache *mfc;
2435 
2436 	rcu_read_lock();
2437 	for (it->ct = 0; it->ct < MFC_LINES; it->ct++) {
2438 		it->cache = &mrt->mfc_cache_array[it->ct];
2439 		list_for_each_entry_rcu(mfc, it->cache, list)
2440 			if (pos-- == 0)
2441 				return mfc;
2442 	}
2443 	rcu_read_unlock();
2444 
2445 	spin_lock_bh(&mfc_unres_lock);
2446 	it->cache = &mrt->mfc_unres_queue;
2447 	list_for_each_entry(mfc, it->cache, list)
2448 		if (pos-- == 0)
2449 			return mfc;
2450 	spin_unlock_bh(&mfc_unres_lock);
2451 
2452 	it->cache = NULL;
2453 	return NULL;
2454 }
2455 
2456 
2457 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2458 {
2459 	struct ipmr_mfc_iter *it = seq->private;
2460 	struct net *net = seq_file_net(seq);
2461 	struct mr_table *mrt;
2462 
2463 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2464 	if (mrt == NULL)
2465 		return ERR_PTR(-ENOENT);
2466 
2467 	it->mrt = mrt;
2468 	it->cache = NULL;
2469 	it->ct = 0;
2470 	return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
2471 		: SEQ_START_TOKEN;
2472 }
2473 
2474 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2475 {
2476 	struct mfc_cache *mfc = v;
2477 	struct ipmr_mfc_iter *it = seq->private;
2478 	struct net *net = seq_file_net(seq);
2479 	struct mr_table *mrt = it->mrt;
2480 
2481 	++*pos;
2482 
2483 	if (v == SEQ_START_TOKEN)
2484 		return ipmr_mfc_seq_idx(net, seq->private, 0);
2485 
2486 	if (mfc->list.next != it->cache)
2487 		return list_entry(mfc->list.next, struct mfc_cache, list);
2488 
2489 	if (it->cache == &mrt->mfc_unres_queue)
2490 		goto end_of_list;
2491 
2492 	BUG_ON(it->cache != &mrt->mfc_cache_array[it->ct]);
2493 
2494 	while (++it->ct < MFC_LINES) {
2495 		it->cache = &mrt->mfc_cache_array[it->ct];
2496 		if (list_empty(it->cache))
2497 			continue;
2498 		return list_first_entry(it->cache, struct mfc_cache, list);
2499 	}
2500 
2501 	/* exhausted cache_array, show unresolved */
2502 	rcu_read_unlock();
2503 	it->cache = &mrt->mfc_unres_queue;
2504 	it->ct = 0;
2505 
2506 	spin_lock_bh(&mfc_unres_lock);
2507 	if (!list_empty(it->cache))
2508 		return list_first_entry(it->cache, struct mfc_cache, list);
2509 
2510 end_of_list:
2511 	spin_unlock_bh(&mfc_unres_lock);
2512 	it->cache = NULL;
2513 
2514 	return NULL;
2515 }
2516 
2517 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
2518 {
2519 	struct ipmr_mfc_iter *it = seq->private;
2520 	struct mr_table *mrt = it->mrt;
2521 
2522 	if (it->cache == &mrt->mfc_unres_queue)
2523 		spin_unlock_bh(&mfc_unres_lock);
2524 	else if (it->cache == &mrt->mfc_cache_array[it->ct])
2525 		rcu_read_unlock();
2526 }
2527 
2528 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2529 {
2530 	int n;
2531 
2532 	if (v == SEQ_START_TOKEN) {
2533 		seq_puts(seq,
2534 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2535 	} else {
2536 		const struct mfc_cache *mfc = v;
2537 		const struct ipmr_mfc_iter *it = seq->private;
2538 		const struct mr_table *mrt = it->mrt;
2539 
2540 		seq_printf(seq, "%08X %08X %-3hd",
2541 			   (__force u32) mfc->mfc_mcastgrp,
2542 			   (__force u32) mfc->mfc_origin,
2543 			   mfc->mfc_parent);
2544 
2545 		if (it->cache != &mrt->mfc_unres_queue) {
2546 			seq_printf(seq, " %8lu %8lu %8lu",
2547 				   mfc->mfc_un.res.pkt,
2548 				   mfc->mfc_un.res.bytes,
2549 				   mfc->mfc_un.res.wrong_if);
2550 			for (n = mfc->mfc_un.res.minvif;
2551 			     n < mfc->mfc_un.res.maxvif; n++) {
2552 				if (VIF_EXISTS(mrt, n) &&
2553 				    mfc->mfc_un.res.ttls[n] < 255)
2554 					seq_printf(seq,
2555 					   " %2d:%-3d",
2556 					   n, mfc->mfc_un.res.ttls[n]);
2557 			}
2558 		} else {
2559 			/* unresolved mfc_caches don't contain
2560 			 * pkt, bytes and wrong_if values
2561 			 */
2562 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
2563 		}
2564 		seq_putc(seq, '\n');
2565 	}
2566 	return 0;
2567 }
2568 
2569 static const struct seq_operations ipmr_mfc_seq_ops = {
2570 	.start = ipmr_mfc_seq_start,
2571 	.next  = ipmr_mfc_seq_next,
2572 	.stop  = ipmr_mfc_seq_stop,
2573 	.show  = ipmr_mfc_seq_show,
2574 };
2575 
2576 static int ipmr_mfc_open(struct inode *inode, struct file *file)
2577 {
2578 	return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
2579 			    sizeof(struct ipmr_mfc_iter));
2580 }
2581 
2582 static const struct file_operations ipmr_mfc_fops = {
2583 	.owner	 = THIS_MODULE,
2584 	.open    = ipmr_mfc_open,
2585 	.read    = seq_read,
2586 	.llseek  = seq_lseek,
2587 	.release = seq_release_net,
2588 };
2589 #endif
2590 
2591 #ifdef CONFIG_IP_PIMSM_V2
2592 static const struct net_protocol pim_protocol = {
2593 	.handler	=	pim_rcv,
2594 	.netns_ok	=	1,
2595 };
2596 #endif
2597 
2598 
2599 /*
2600  *	Setup for IP multicast routing
2601  */
2602 static int __net_init ipmr_net_init(struct net *net)
2603 {
2604 	int err;
2605 
2606 	err = ipmr_rules_init(net);
2607 	if (err < 0)
2608 		goto fail;
2609 
2610 #ifdef CONFIG_PROC_FS
2611 	err = -ENOMEM;
2612 	if (!proc_net_fops_create(net, "ip_mr_vif", 0, &ipmr_vif_fops))
2613 		goto proc_vif_fail;
2614 	if (!proc_net_fops_create(net, "ip_mr_cache", 0, &ipmr_mfc_fops))
2615 		goto proc_cache_fail;
2616 #endif
2617 	return 0;
2618 
2619 #ifdef CONFIG_PROC_FS
2620 proc_cache_fail:
2621 	proc_net_remove(net, "ip_mr_vif");
2622 proc_vif_fail:
2623 	ipmr_rules_exit(net);
2624 #endif
2625 fail:
2626 	return err;
2627 }
2628 
2629 static void __net_exit ipmr_net_exit(struct net *net)
2630 {
2631 #ifdef CONFIG_PROC_FS
2632 	proc_net_remove(net, "ip_mr_cache");
2633 	proc_net_remove(net, "ip_mr_vif");
2634 #endif
2635 	ipmr_rules_exit(net);
2636 }
2637 
2638 static struct pernet_operations ipmr_net_ops = {
2639 	.init = ipmr_net_init,
2640 	.exit = ipmr_net_exit,
2641 };
2642 
2643 int __init ip_mr_init(void)
2644 {
2645 	int err;
2646 
2647 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
2648 				       sizeof(struct mfc_cache),
2649 				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
2650 				       NULL);
2651 	if (!mrt_cachep)
2652 		return -ENOMEM;
2653 
2654 	err = register_pernet_subsys(&ipmr_net_ops);
2655 	if (err)
2656 		goto reg_pernet_fail;
2657 
2658 	err = register_netdevice_notifier(&ip_mr_notifier);
2659 	if (err)
2660 		goto reg_notif_fail;
2661 #ifdef CONFIG_IP_PIMSM_V2
2662 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
2663 		pr_err("%s: can't add PIM protocol\n", __func__);
2664 		err = -EAGAIN;
2665 		goto add_proto_fail;
2666 	}
2667 #endif
2668 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
2669 		      NULL, ipmr_rtm_dumproute, NULL);
2670 	return 0;
2671 
2672 #ifdef CONFIG_IP_PIMSM_V2
2673 add_proto_fail:
2674 	unregister_netdevice_notifier(&ip_mr_notifier);
2675 #endif
2676 reg_notif_fail:
2677 	unregister_pernet_subsys(&ipmr_net_ops);
2678 reg_pernet_fail:
2679 	kmem_cache_destroy(mrt_cachep);
2680 	return err;
2681 }
2682