xref: /linux/net/ipv4/ipmr.c (revision 2d87650a3bf1b80f7d0d150ee1af3f8a89e5b7aa)
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/ip_tunnels.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 void 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 			neigh_parms_data_state_setall(in_dev->arp_parms);
429 			IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
430 
431 			if (dev_open(dev))
432 				goto failure;
433 			dev_hold(dev);
434 		}
435 	}
436 	return dev;
437 
438 failure:
439 	/* allow the register to be completed before unregistering. */
440 	rtnl_unlock();
441 	rtnl_lock();
442 
443 	unregister_netdevice(dev);
444 	return NULL;
445 }
446 
447 #ifdef CONFIG_IP_PIMSM
448 
449 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
450 {
451 	struct net *net = dev_net(dev);
452 	struct mr_table *mrt;
453 	struct flowi4 fl4 = {
454 		.flowi4_oif	= dev->ifindex,
455 		.flowi4_iif	= skb->skb_iif,
456 		.flowi4_mark	= skb->mark,
457 	};
458 	int err;
459 
460 	err = ipmr_fib_lookup(net, &fl4, &mrt);
461 	if (err < 0) {
462 		kfree_skb(skb);
463 		return err;
464 	}
465 
466 	read_lock(&mrt_lock);
467 	dev->stats.tx_bytes += skb->len;
468 	dev->stats.tx_packets++;
469 	ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
470 	read_unlock(&mrt_lock);
471 	kfree_skb(skb);
472 	return NETDEV_TX_OK;
473 }
474 
475 static const struct net_device_ops reg_vif_netdev_ops = {
476 	.ndo_start_xmit	= reg_vif_xmit,
477 };
478 
479 static void reg_vif_setup(struct net_device *dev)
480 {
481 	dev->type		= ARPHRD_PIMREG;
482 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
483 	dev->flags		= IFF_NOARP;
484 	dev->netdev_ops		= &reg_vif_netdev_ops,
485 	dev->destructor		= free_netdev;
486 	dev->features		|= NETIF_F_NETNS_LOCAL;
487 }
488 
489 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
490 {
491 	struct net_device *dev;
492 	struct in_device *in_dev;
493 	char name[IFNAMSIZ];
494 
495 	if (mrt->id == RT_TABLE_DEFAULT)
496 		sprintf(name, "pimreg");
497 	else
498 		sprintf(name, "pimreg%u", mrt->id);
499 
500 	dev = alloc_netdev(0, name, reg_vif_setup);
501 
502 	if (dev == NULL)
503 		return NULL;
504 
505 	dev_net_set(dev, net);
506 
507 	if (register_netdevice(dev)) {
508 		free_netdev(dev);
509 		return NULL;
510 	}
511 	dev->iflink = 0;
512 
513 	rcu_read_lock();
514 	in_dev = __in_dev_get_rcu(dev);
515 	if (!in_dev) {
516 		rcu_read_unlock();
517 		goto failure;
518 	}
519 
520 	ipv4_devconf_setall(in_dev);
521 	neigh_parms_data_state_setall(in_dev->arp_parms);
522 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
523 	rcu_read_unlock();
524 
525 	if (dev_open(dev))
526 		goto failure;
527 
528 	dev_hold(dev);
529 
530 	return dev;
531 
532 failure:
533 	/* allow the register to be completed before unregistering. */
534 	rtnl_unlock();
535 	rtnl_lock();
536 
537 	unregister_netdevice(dev);
538 	return NULL;
539 }
540 #endif
541 
542 /**
543  *	vif_delete - Delete a VIF entry
544  *	@notify: Set to 1, if the caller is a notifier_call
545  */
546 
547 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
548 		      struct list_head *head)
549 {
550 	struct vif_device *v;
551 	struct net_device *dev;
552 	struct in_device *in_dev;
553 
554 	if (vifi < 0 || vifi >= mrt->maxvif)
555 		return -EADDRNOTAVAIL;
556 
557 	v = &mrt->vif_table[vifi];
558 
559 	write_lock_bh(&mrt_lock);
560 	dev = v->dev;
561 	v->dev = NULL;
562 
563 	if (!dev) {
564 		write_unlock_bh(&mrt_lock);
565 		return -EADDRNOTAVAIL;
566 	}
567 
568 #ifdef CONFIG_IP_PIMSM
569 	if (vifi == mrt->mroute_reg_vif_num)
570 		mrt->mroute_reg_vif_num = -1;
571 #endif
572 
573 	if (vifi + 1 == mrt->maxvif) {
574 		int tmp;
575 
576 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
577 			if (VIF_EXISTS(mrt, tmp))
578 				break;
579 		}
580 		mrt->maxvif = tmp+1;
581 	}
582 
583 	write_unlock_bh(&mrt_lock);
584 
585 	dev_set_allmulti(dev, -1);
586 
587 	in_dev = __in_dev_get_rtnl(dev);
588 	if (in_dev) {
589 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
590 		inet_netconf_notify_devconf(dev_net(dev),
591 					    NETCONFA_MC_FORWARDING,
592 					    dev->ifindex, &in_dev->cnf);
593 		ip_rt_multicast_event(in_dev);
594 	}
595 
596 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
597 		unregister_netdevice_queue(dev, head);
598 
599 	dev_put(dev);
600 	return 0;
601 }
602 
603 static void ipmr_cache_free_rcu(struct rcu_head *head)
604 {
605 	struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
606 
607 	kmem_cache_free(mrt_cachep, c);
608 }
609 
610 static inline void ipmr_cache_free(struct mfc_cache *c)
611 {
612 	call_rcu(&c->rcu, ipmr_cache_free_rcu);
613 }
614 
615 /* Destroy an unresolved cache entry, killing queued skbs
616  * and reporting error to netlink readers.
617  */
618 
619 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
620 {
621 	struct net *net = read_pnet(&mrt->net);
622 	struct sk_buff *skb;
623 	struct nlmsgerr *e;
624 
625 	atomic_dec(&mrt->cache_resolve_queue_len);
626 
627 	while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
628 		if (ip_hdr(skb)->version == 0) {
629 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
630 			nlh->nlmsg_type = NLMSG_ERROR;
631 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
632 			skb_trim(skb, nlh->nlmsg_len);
633 			e = nlmsg_data(nlh);
634 			e->error = -ETIMEDOUT;
635 			memset(&e->msg, 0, sizeof(e->msg));
636 
637 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
638 		} else {
639 			kfree_skb(skb);
640 		}
641 	}
642 
643 	ipmr_cache_free(c);
644 }
645 
646 
647 /* Timer process for the unresolved queue. */
648 
649 static void ipmr_expire_process(unsigned long arg)
650 {
651 	struct mr_table *mrt = (struct mr_table *)arg;
652 	unsigned long now;
653 	unsigned long expires;
654 	struct mfc_cache *c, *next;
655 
656 	if (!spin_trylock(&mfc_unres_lock)) {
657 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
658 		return;
659 	}
660 
661 	if (list_empty(&mrt->mfc_unres_queue))
662 		goto out;
663 
664 	now = jiffies;
665 	expires = 10*HZ;
666 
667 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
668 		if (time_after(c->mfc_un.unres.expires, now)) {
669 			unsigned long interval = c->mfc_un.unres.expires - now;
670 			if (interval < expires)
671 				expires = interval;
672 			continue;
673 		}
674 
675 		list_del(&c->list);
676 		mroute_netlink_event(mrt, c, RTM_DELROUTE);
677 		ipmr_destroy_unres(mrt, c);
678 	}
679 
680 	if (!list_empty(&mrt->mfc_unres_queue))
681 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
682 
683 out:
684 	spin_unlock(&mfc_unres_lock);
685 }
686 
687 /* Fill oifs list. It is called under write locked mrt_lock. */
688 
689 static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
690 				   unsigned char *ttls)
691 {
692 	int vifi;
693 
694 	cache->mfc_un.res.minvif = MAXVIFS;
695 	cache->mfc_un.res.maxvif = 0;
696 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
697 
698 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
699 		if (VIF_EXISTS(mrt, vifi) &&
700 		    ttls[vifi] && ttls[vifi] < 255) {
701 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
702 			if (cache->mfc_un.res.minvif > vifi)
703 				cache->mfc_un.res.minvif = vifi;
704 			if (cache->mfc_un.res.maxvif <= vifi)
705 				cache->mfc_un.res.maxvif = vifi + 1;
706 		}
707 	}
708 }
709 
710 static int vif_add(struct net *net, struct mr_table *mrt,
711 		   struct vifctl *vifc, int mrtsock)
712 {
713 	int vifi = vifc->vifc_vifi;
714 	struct vif_device *v = &mrt->vif_table[vifi];
715 	struct net_device *dev;
716 	struct in_device *in_dev;
717 	int err;
718 
719 	/* Is vif busy ? */
720 	if (VIF_EXISTS(mrt, vifi))
721 		return -EADDRINUSE;
722 
723 	switch (vifc->vifc_flags) {
724 #ifdef CONFIG_IP_PIMSM
725 	case VIFF_REGISTER:
726 		/*
727 		 * Special Purpose VIF in PIM
728 		 * All the packets will be sent to the daemon
729 		 */
730 		if (mrt->mroute_reg_vif_num >= 0)
731 			return -EADDRINUSE;
732 		dev = ipmr_reg_vif(net, mrt);
733 		if (!dev)
734 			return -ENOBUFS;
735 		err = dev_set_allmulti(dev, 1);
736 		if (err) {
737 			unregister_netdevice(dev);
738 			dev_put(dev);
739 			return err;
740 		}
741 		break;
742 #endif
743 	case VIFF_TUNNEL:
744 		dev = ipmr_new_tunnel(net, vifc);
745 		if (!dev)
746 			return -ENOBUFS;
747 		err = dev_set_allmulti(dev, 1);
748 		if (err) {
749 			ipmr_del_tunnel(dev, vifc);
750 			dev_put(dev);
751 			return err;
752 		}
753 		break;
754 
755 	case VIFF_USE_IFINDEX:
756 	case 0:
757 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
758 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
759 			if (dev && __in_dev_get_rtnl(dev) == NULL) {
760 				dev_put(dev);
761 				return -EADDRNOTAVAIL;
762 			}
763 		} else {
764 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
765 		}
766 		if (!dev)
767 			return -EADDRNOTAVAIL;
768 		err = dev_set_allmulti(dev, 1);
769 		if (err) {
770 			dev_put(dev);
771 			return err;
772 		}
773 		break;
774 	default:
775 		return -EINVAL;
776 	}
777 
778 	in_dev = __in_dev_get_rtnl(dev);
779 	if (!in_dev) {
780 		dev_put(dev);
781 		return -EADDRNOTAVAIL;
782 	}
783 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
784 	inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING, dev->ifindex,
785 				    &in_dev->cnf);
786 	ip_rt_multicast_event(in_dev);
787 
788 	/* Fill in the VIF structures */
789 
790 	v->rate_limit = vifc->vifc_rate_limit;
791 	v->local = vifc->vifc_lcl_addr.s_addr;
792 	v->remote = vifc->vifc_rmt_addr.s_addr;
793 	v->flags = vifc->vifc_flags;
794 	if (!mrtsock)
795 		v->flags |= VIFF_STATIC;
796 	v->threshold = vifc->vifc_threshold;
797 	v->bytes_in = 0;
798 	v->bytes_out = 0;
799 	v->pkt_in = 0;
800 	v->pkt_out = 0;
801 	v->link = dev->ifindex;
802 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
803 		v->link = dev->iflink;
804 
805 	/* And finish update writing critical data */
806 	write_lock_bh(&mrt_lock);
807 	v->dev = dev;
808 #ifdef CONFIG_IP_PIMSM
809 	if (v->flags & VIFF_REGISTER)
810 		mrt->mroute_reg_vif_num = vifi;
811 #endif
812 	if (vifi+1 > mrt->maxvif)
813 		mrt->maxvif = vifi+1;
814 	write_unlock_bh(&mrt_lock);
815 	return 0;
816 }
817 
818 /* called with rcu_read_lock() */
819 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
820 					 __be32 origin,
821 					 __be32 mcastgrp)
822 {
823 	int line = MFC_HASH(mcastgrp, origin);
824 	struct mfc_cache *c;
825 
826 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list) {
827 		if (c->mfc_origin == origin && c->mfc_mcastgrp == mcastgrp)
828 			return c;
829 	}
830 	return NULL;
831 }
832 
833 /* Look for a (*,*,oif) entry */
834 static struct mfc_cache *ipmr_cache_find_any_parent(struct mr_table *mrt,
835 						    int vifi)
836 {
837 	int line = MFC_HASH(htonl(INADDR_ANY), htonl(INADDR_ANY));
838 	struct mfc_cache *c;
839 
840 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list)
841 		if (c->mfc_origin == htonl(INADDR_ANY) &&
842 		    c->mfc_mcastgrp == htonl(INADDR_ANY) &&
843 		    c->mfc_un.res.ttls[vifi] < 255)
844 			return c;
845 
846 	return NULL;
847 }
848 
849 /* Look for a (*,G) entry */
850 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
851 					     __be32 mcastgrp, int vifi)
852 {
853 	int line = MFC_HASH(mcastgrp, htonl(INADDR_ANY));
854 	struct mfc_cache *c, *proxy;
855 
856 	if (mcastgrp == htonl(INADDR_ANY))
857 		goto skip;
858 
859 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list)
860 		if (c->mfc_origin == htonl(INADDR_ANY) &&
861 		    c->mfc_mcastgrp == mcastgrp) {
862 			if (c->mfc_un.res.ttls[vifi] < 255)
863 				return c;
864 
865 			/* It's ok if the vifi is part of the static tree */
866 			proxy = ipmr_cache_find_any_parent(mrt,
867 							   c->mfc_parent);
868 			if (proxy && proxy->mfc_un.res.ttls[vifi] < 255)
869 				return c;
870 		}
871 
872 skip:
873 	return ipmr_cache_find_any_parent(mrt, vifi);
874 }
875 
876 /*
877  *	Allocate a multicast cache entry
878  */
879 static struct mfc_cache *ipmr_cache_alloc(void)
880 {
881 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
882 
883 	if (c)
884 		c->mfc_un.res.minvif = MAXVIFS;
885 	return c;
886 }
887 
888 static struct mfc_cache *ipmr_cache_alloc_unres(void)
889 {
890 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
891 
892 	if (c) {
893 		skb_queue_head_init(&c->mfc_un.unres.unresolved);
894 		c->mfc_un.unres.expires = jiffies + 10*HZ;
895 	}
896 	return c;
897 }
898 
899 /*
900  *	A cache entry has gone into a resolved state from queued
901  */
902 
903 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
904 			       struct mfc_cache *uc, struct mfc_cache *c)
905 {
906 	struct sk_buff *skb;
907 	struct nlmsgerr *e;
908 
909 	/* Play the pending entries through our router */
910 
911 	while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
912 		if (ip_hdr(skb)->version == 0) {
913 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
914 
915 			if (__ipmr_fill_mroute(mrt, skb, c, nlmsg_data(nlh)) > 0) {
916 				nlh->nlmsg_len = skb_tail_pointer(skb) -
917 						 (u8 *)nlh;
918 			} else {
919 				nlh->nlmsg_type = NLMSG_ERROR;
920 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
921 				skb_trim(skb, nlh->nlmsg_len);
922 				e = nlmsg_data(nlh);
923 				e->error = -EMSGSIZE;
924 				memset(&e->msg, 0, sizeof(e->msg));
925 			}
926 
927 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
928 		} else {
929 			ip_mr_forward(net, mrt, skb, c, 0);
930 		}
931 	}
932 }
933 
934 /*
935  *	Bounce a cache query up to mrouted. We could use netlink for this but mrouted
936  *	expects the following bizarre scheme.
937  *
938  *	Called under mrt_lock.
939  */
940 
941 static int ipmr_cache_report(struct mr_table *mrt,
942 			     struct sk_buff *pkt, vifi_t vifi, int assert)
943 {
944 	struct sk_buff *skb;
945 	const int ihl = ip_hdrlen(pkt);
946 	struct igmphdr *igmp;
947 	struct igmpmsg *msg;
948 	struct sock *mroute_sk;
949 	int ret;
950 
951 #ifdef CONFIG_IP_PIMSM
952 	if (assert == IGMPMSG_WHOLEPKT)
953 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
954 	else
955 #endif
956 		skb = alloc_skb(128, GFP_ATOMIC);
957 
958 	if (!skb)
959 		return -ENOBUFS;
960 
961 #ifdef CONFIG_IP_PIMSM
962 	if (assert == IGMPMSG_WHOLEPKT) {
963 		/* Ugly, but we have no choice with this interface.
964 		 * Duplicate old header, fix ihl, length etc.
965 		 * And all this only to mangle msg->im_msgtype and
966 		 * to set msg->im_mbz to "mbz" :-)
967 		 */
968 		skb_push(skb, sizeof(struct iphdr));
969 		skb_reset_network_header(skb);
970 		skb_reset_transport_header(skb);
971 		msg = (struct igmpmsg *)skb_network_header(skb);
972 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
973 		msg->im_msgtype = IGMPMSG_WHOLEPKT;
974 		msg->im_mbz = 0;
975 		msg->im_vif = mrt->mroute_reg_vif_num;
976 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
977 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
978 					     sizeof(struct iphdr));
979 	} else
980 #endif
981 	{
982 
983 	/* Copy the IP header */
984 
985 	skb_set_network_header(skb, skb->len);
986 	skb_put(skb, ihl);
987 	skb_copy_to_linear_data(skb, pkt->data, ihl);
988 	ip_hdr(skb)->protocol = 0;	/* Flag to the kernel this is a route add */
989 	msg = (struct igmpmsg *)skb_network_header(skb);
990 	msg->im_vif = vifi;
991 	skb_dst_set(skb, dst_clone(skb_dst(pkt)));
992 
993 	/* Add our header */
994 
995 	igmp = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
996 	igmp->type	=
997 	msg->im_msgtype = assert;
998 	igmp->code	= 0;
999 	ip_hdr(skb)->tot_len = htons(skb->len);		/* Fix the length */
1000 	skb->transport_header = skb->network_header;
1001 	}
1002 
1003 	rcu_read_lock();
1004 	mroute_sk = rcu_dereference(mrt->mroute_sk);
1005 	if (mroute_sk == NULL) {
1006 		rcu_read_unlock();
1007 		kfree_skb(skb);
1008 		return -EINVAL;
1009 	}
1010 
1011 	/* Deliver to mrouted */
1012 
1013 	ret = sock_queue_rcv_skb(mroute_sk, skb);
1014 	rcu_read_unlock();
1015 	if (ret < 0) {
1016 		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1017 		kfree_skb(skb);
1018 	}
1019 
1020 	return ret;
1021 }
1022 
1023 /*
1024  *	Queue a packet for resolution. It gets locked cache entry!
1025  */
1026 
1027 static int
1028 ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi, struct sk_buff *skb)
1029 {
1030 	bool found = false;
1031 	int err;
1032 	struct mfc_cache *c;
1033 	const struct iphdr *iph = ip_hdr(skb);
1034 
1035 	spin_lock_bh(&mfc_unres_lock);
1036 	list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
1037 		if (c->mfc_mcastgrp == iph->daddr &&
1038 		    c->mfc_origin == iph->saddr) {
1039 			found = true;
1040 			break;
1041 		}
1042 	}
1043 
1044 	if (!found) {
1045 		/* Create a new entry if allowable */
1046 
1047 		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
1048 		    (c = ipmr_cache_alloc_unres()) == NULL) {
1049 			spin_unlock_bh(&mfc_unres_lock);
1050 
1051 			kfree_skb(skb);
1052 			return -ENOBUFS;
1053 		}
1054 
1055 		/* Fill in the new cache entry */
1056 
1057 		c->mfc_parent	= -1;
1058 		c->mfc_origin	= iph->saddr;
1059 		c->mfc_mcastgrp	= iph->daddr;
1060 
1061 		/* Reflect first query at mrouted. */
1062 
1063 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1064 		if (err < 0) {
1065 			/* If the report failed throw the cache entry
1066 			   out - Brad Parker
1067 			 */
1068 			spin_unlock_bh(&mfc_unres_lock);
1069 
1070 			ipmr_cache_free(c);
1071 			kfree_skb(skb);
1072 			return err;
1073 		}
1074 
1075 		atomic_inc(&mrt->cache_resolve_queue_len);
1076 		list_add(&c->list, &mrt->mfc_unres_queue);
1077 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1078 
1079 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1080 			mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1081 	}
1082 
1083 	/* See if we can append the packet */
1084 
1085 	if (c->mfc_un.unres.unresolved.qlen > 3) {
1086 		kfree_skb(skb);
1087 		err = -ENOBUFS;
1088 	} else {
1089 		skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1090 		err = 0;
1091 	}
1092 
1093 	spin_unlock_bh(&mfc_unres_lock);
1094 	return err;
1095 }
1096 
1097 /*
1098  *	MFC cache manipulation by user space mroute daemon
1099  */
1100 
1101 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1102 {
1103 	int line;
1104 	struct mfc_cache *c, *next;
1105 
1106 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1107 
1108 	list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[line], list) {
1109 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1110 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr &&
1111 		    (parent == -1 || parent == c->mfc_parent)) {
1112 			list_del_rcu(&c->list);
1113 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1114 			ipmr_cache_free(c);
1115 			return 0;
1116 		}
1117 	}
1118 	return -ENOENT;
1119 }
1120 
1121 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1122 			struct mfcctl *mfc, int mrtsock, int parent)
1123 {
1124 	bool found = false;
1125 	int line;
1126 	struct mfc_cache *uc, *c;
1127 
1128 	if (mfc->mfcc_parent >= MAXVIFS)
1129 		return -ENFILE;
1130 
1131 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1132 
1133 	list_for_each_entry(c, &mrt->mfc_cache_array[line], list) {
1134 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1135 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr &&
1136 		    (parent == -1 || parent == c->mfc_parent)) {
1137 			found = true;
1138 			break;
1139 		}
1140 	}
1141 
1142 	if (found) {
1143 		write_lock_bh(&mrt_lock);
1144 		c->mfc_parent = mfc->mfcc_parent;
1145 		ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1146 		if (!mrtsock)
1147 			c->mfc_flags |= MFC_STATIC;
1148 		write_unlock_bh(&mrt_lock);
1149 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1150 		return 0;
1151 	}
1152 
1153 	if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1154 	    !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1155 		return -EINVAL;
1156 
1157 	c = ipmr_cache_alloc();
1158 	if (c == NULL)
1159 		return -ENOMEM;
1160 
1161 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1162 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1163 	c->mfc_parent = mfc->mfcc_parent;
1164 	ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1165 	if (!mrtsock)
1166 		c->mfc_flags |= MFC_STATIC;
1167 
1168 	list_add_rcu(&c->list, &mrt->mfc_cache_array[line]);
1169 
1170 	/*
1171 	 *	Check to see if we resolved a queued list. If so we
1172 	 *	need to send on the frames and tidy up.
1173 	 */
1174 	found = false;
1175 	spin_lock_bh(&mfc_unres_lock);
1176 	list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1177 		if (uc->mfc_origin == c->mfc_origin &&
1178 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1179 			list_del(&uc->list);
1180 			atomic_dec(&mrt->cache_resolve_queue_len);
1181 			found = true;
1182 			break;
1183 		}
1184 	}
1185 	if (list_empty(&mrt->mfc_unres_queue))
1186 		del_timer(&mrt->ipmr_expire_timer);
1187 	spin_unlock_bh(&mfc_unres_lock);
1188 
1189 	if (found) {
1190 		ipmr_cache_resolve(net, mrt, uc, c);
1191 		ipmr_cache_free(uc);
1192 	}
1193 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1194 	return 0;
1195 }
1196 
1197 /*
1198  *	Close the multicast socket, and clear the vif tables etc
1199  */
1200 
1201 static void mroute_clean_tables(struct mr_table *mrt)
1202 {
1203 	int i;
1204 	LIST_HEAD(list);
1205 	struct mfc_cache *c, *next;
1206 
1207 	/* Shut down all active vif entries */
1208 
1209 	for (i = 0; i < mrt->maxvif; i++) {
1210 		if (!(mrt->vif_table[i].flags & VIFF_STATIC))
1211 			vif_delete(mrt, i, 0, &list);
1212 	}
1213 	unregister_netdevice_many(&list);
1214 
1215 	/* Wipe the cache */
1216 
1217 	for (i = 0; i < MFC_LINES; i++) {
1218 		list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[i], list) {
1219 			if (c->mfc_flags & MFC_STATIC)
1220 				continue;
1221 			list_del_rcu(&c->list);
1222 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1223 			ipmr_cache_free(c);
1224 		}
1225 	}
1226 
1227 	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1228 		spin_lock_bh(&mfc_unres_lock);
1229 		list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
1230 			list_del(&c->list);
1231 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1232 			ipmr_destroy_unres(mrt, c);
1233 		}
1234 		spin_unlock_bh(&mfc_unres_lock);
1235 	}
1236 }
1237 
1238 /* called from ip_ra_control(), before an RCU grace period,
1239  * we dont need to call synchronize_rcu() here
1240  */
1241 static void mrtsock_destruct(struct sock *sk)
1242 {
1243 	struct net *net = sock_net(sk);
1244 	struct mr_table *mrt;
1245 
1246 	rtnl_lock();
1247 	ipmr_for_each_table(mrt, net) {
1248 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1249 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1250 			inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1251 						    NETCONFA_IFINDEX_ALL,
1252 						    net->ipv4.devconf_all);
1253 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1254 			mroute_clean_tables(mrt);
1255 		}
1256 	}
1257 	rtnl_unlock();
1258 }
1259 
1260 /*
1261  *	Socket options and virtual interface manipulation. The whole
1262  *	virtual interface system is a complete heap, but unfortunately
1263  *	that's how BSD mrouted happens to think. Maybe one day with a proper
1264  *	MOSPF/PIM router set up we can clean this up.
1265  */
1266 
1267 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen)
1268 {
1269 	int ret, parent = 0;
1270 	struct vifctl vif;
1271 	struct mfcctl mfc;
1272 	struct net *net = sock_net(sk);
1273 	struct mr_table *mrt;
1274 
1275 	if (sk->sk_type != SOCK_RAW ||
1276 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1277 		return -EOPNOTSUPP;
1278 
1279 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1280 	if (mrt == NULL)
1281 		return -ENOENT;
1282 
1283 	if (optname != MRT_INIT) {
1284 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1285 		    !ns_capable(net->user_ns, CAP_NET_ADMIN))
1286 			return -EACCES;
1287 	}
1288 
1289 	switch (optname) {
1290 	case MRT_INIT:
1291 		if (optlen != sizeof(int))
1292 			return -EINVAL;
1293 
1294 		rtnl_lock();
1295 		if (rtnl_dereference(mrt->mroute_sk)) {
1296 			rtnl_unlock();
1297 			return -EADDRINUSE;
1298 		}
1299 
1300 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1301 		if (ret == 0) {
1302 			rcu_assign_pointer(mrt->mroute_sk, sk);
1303 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1304 			inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1305 						    NETCONFA_IFINDEX_ALL,
1306 						    net->ipv4.devconf_all);
1307 		}
1308 		rtnl_unlock();
1309 		return ret;
1310 	case MRT_DONE:
1311 		if (sk != rcu_access_pointer(mrt->mroute_sk))
1312 			return -EACCES;
1313 		return ip_ra_control(sk, 0, NULL);
1314 	case MRT_ADD_VIF:
1315 	case MRT_DEL_VIF:
1316 		if (optlen != sizeof(vif))
1317 			return -EINVAL;
1318 		if (copy_from_user(&vif, optval, sizeof(vif)))
1319 			return -EFAULT;
1320 		if (vif.vifc_vifi >= MAXVIFS)
1321 			return -ENFILE;
1322 		rtnl_lock();
1323 		if (optname == MRT_ADD_VIF) {
1324 			ret = vif_add(net, mrt, &vif,
1325 				      sk == rtnl_dereference(mrt->mroute_sk));
1326 		} else {
1327 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1328 		}
1329 		rtnl_unlock();
1330 		return ret;
1331 
1332 		/*
1333 		 *	Manipulate the forwarding caches. These live
1334 		 *	in a sort of kernel/user symbiosis.
1335 		 */
1336 	case MRT_ADD_MFC:
1337 	case MRT_DEL_MFC:
1338 		parent = -1;
1339 	case MRT_ADD_MFC_PROXY:
1340 	case MRT_DEL_MFC_PROXY:
1341 		if (optlen != sizeof(mfc))
1342 			return -EINVAL;
1343 		if (copy_from_user(&mfc, optval, sizeof(mfc)))
1344 			return -EFAULT;
1345 		if (parent == 0)
1346 			parent = mfc.mfcc_parent;
1347 		rtnl_lock();
1348 		if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1349 			ret = ipmr_mfc_delete(mrt, &mfc, parent);
1350 		else
1351 			ret = ipmr_mfc_add(net, mrt, &mfc,
1352 					   sk == rtnl_dereference(mrt->mroute_sk),
1353 					   parent);
1354 		rtnl_unlock();
1355 		return ret;
1356 		/*
1357 		 *	Control PIM assert.
1358 		 */
1359 	case MRT_ASSERT:
1360 	{
1361 		int v;
1362 		if (optlen != sizeof(v))
1363 			return -EINVAL;
1364 		if (get_user(v, (int __user *)optval))
1365 			return -EFAULT;
1366 		mrt->mroute_do_assert = v;
1367 		return 0;
1368 	}
1369 #ifdef CONFIG_IP_PIMSM
1370 	case MRT_PIM:
1371 	{
1372 		int v;
1373 
1374 		if (optlen != sizeof(v))
1375 			return -EINVAL;
1376 		if (get_user(v, (int __user *)optval))
1377 			return -EFAULT;
1378 		v = !!v;
1379 
1380 		rtnl_lock();
1381 		ret = 0;
1382 		if (v != mrt->mroute_do_pim) {
1383 			mrt->mroute_do_pim = v;
1384 			mrt->mroute_do_assert = v;
1385 		}
1386 		rtnl_unlock();
1387 		return ret;
1388 	}
1389 #endif
1390 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
1391 	case MRT_TABLE:
1392 	{
1393 		u32 v;
1394 
1395 		if (optlen != sizeof(u32))
1396 			return -EINVAL;
1397 		if (get_user(v, (u32 __user *)optval))
1398 			return -EFAULT;
1399 
1400 		/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
1401 		if (v != RT_TABLE_DEFAULT && v >= 1000000000)
1402 			return -EINVAL;
1403 
1404 		rtnl_lock();
1405 		ret = 0;
1406 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1407 			ret = -EBUSY;
1408 		} else {
1409 			if (!ipmr_new_table(net, v))
1410 				ret = -ENOMEM;
1411 			else
1412 				raw_sk(sk)->ipmr_table = v;
1413 		}
1414 		rtnl_unlock();
1415 		return ret;
1416 	}
1417 #endif
1418 	/*
1419 	 *	Spurious command, or MRT_VERSION which you cannot
1420 	 *	set.
1421 	 */
1422 	default:
1423 		return -ENOPROTOOPT;
1424 	}
1425 }
1426 
1427 /*
1428  *	Getsock opt support for the multicast routing system.
1429  */
1430 
1431 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1432 {
1433 	int olr;
1434 	int val;
1435 	struct net *net = sock_net(sk);
1436 	struct mr_table *mrt;
1437 
1438 	if (sk->sk_type != SOCK_RAW ||
1439 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1440 		return -EOPNOTSUPP;
1441 
1442 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1443 	if (mrt == NULL)
1444 		return -ENOENT;
1445 
1446 	if (optname != MRT_VERSION &&
1447 #ifdef CONFIG_IP_PIMSM
1448 	   optname != MRT_PIM &&
1449 #endif
1450 	   optname != MRT_ASSERT)
1451 		return -ENOPROTOOPT;
1452 
1453 	if (get_user(olr, optlen))
1454 		return -EFAULT;
1455 
1456 	olr = min_t(unsigned int, olr, sizeof(int));
1457 	if (olr < 0)
1458 		return -EINVAL;
1459 
1460 	if (put_user(olr, optlen))
1461 		return -EFAULT;
1462 	if (optname == MRT_VERSION)
1463 		val = 0x0305;
1464 #ifdef CONFIG_IP_PIMSM
1465 	else if (optname == MRT_PIM)
1466 		val = mrt->mroute_do_pim;
1467 #endif
1468 	else
1469 		val = mrt->mroute_do_assert;
1470 	if (copy_to_user(optval, &val, olr))
1471 		return -EFAULT;
1472 	return 0;
1473 }
1474 
1475 /*
1476  *	The IP multicast ioctl support routines.
1477  */
1478 
1479 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1480 {
1481 	struct sioc_sg_req sr;
1482 	struct sioc_vif_req vr;
1483 	struct vif_device *vif;
1484 	struct mfc_cache *c;
1485 	struct net *net = sock_net(sk);
1486 	struct mr_table *mrt;
1487 
1488 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1489 	if (mrt == NULL)
1490 		return -ENOENT;
1491 
1492 	switch (cmd) {
1493 	case SIOCGETVIFCNT:
1494 		if (copy_from_user(&vr, arg, sizeof(vr)))
1495 			return -EFAULT;
1496 		if (vr.vifi >= mrt->maxvif)
1497 			return -EINVAL;
1498 		read_lock(&mrt_lock);
1499 		vif = &mrt->vif_table[vr.vifi];
1500 		if (VIF_EXISTS(mrt, vr.vifi)) {
1501 			vr.icount = vif->pkt_in;
1502 			vr.ocount = vif->pkt_out;
1503 			vr.ibytes = vif->bytes_in;
1504 			vr.obytes = vif->bytes_out;
1505 			read_unlock(&mrt_lock);
1506 
1507 			if (copy_to_user(arg, &vr, sizeof(vr)))
1508 				return -EFAULT;
1509 			return 0;
1510 		}
1511 		read_unlock(&mrt_lock);
1512 		return -EADDRNOTAVAIL;
1513 	case SIOCGETSGCNT:
1514 		if (copy_from_user(&sr, arg, sizeof(sr)))
1515 			return -EFAULT;
1516 
1517 		rcu_read_lock();
1518 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1519 		if (c) {
1520 			sr.pktcnt = c->mfc_un.res.pkt;
1521 			sr.bytecnt = c->mfc_un.res.bytes;
1522 			sr.wrong_if = c->mfc_un.res.wrong_if;
1523 			rcu_read_unlock();
1524 
1525 			if (copy_to_user(arg, &sr, sizeof(sr)))
1526 				return -EFAULT;
1527 			return 0;
1528 		}
1529 		rcu_read_unlock();
1530 		return -EADDRNOTAVAIL;
1531 	default:
1532 		return -ENOIOCTLCMD;
1533 	}
1534 }
1535 
1536 #ifdef CONFIG_COMPAT
1537 struct compat_sioc_sg_req {
1538 	struct in_addr src;
1539 	struct in_addr grp;
1540 	compat_ulong_t pktcnt;
1541 	compat_ulong_t bytecnt;
1542 	compat_ulong_t wrong_if;
1543 };
1544 
1545 struct compat_sioc_vif_req {
1546 	vifi_t	vifi;		/* Which iface */
1547 	compat_ulong_t icount;
1548 	compat_ulong_t ocount;
1549 	compat_ulong_t ibytes;
1550 	compat_ulong_t obytes;
1551 };
1552 
1553 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1554 {
1555 	struct compat_sioc_sg_req sr;
1556 	struct compat_sioc_vif_req vr;
1557 	struct vif_device *vif;
1558 	struct mfc_cache *c;
1559 	struct net *net = sock_net(sk);
1560 	struct mr_table *mrt;
1561 
1562 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1563 	if (mrt == NULL)
1564 		return -ENOENT;
1565 
1566 	switch (cmd) {
1567 	case SIOCGETVIFCNT:
1568 		if (copy_from_user(&vr, arg, sizeof(vr)))
1569 			return -EFAULT;
1570 		if (vr.vifi >= mrt->maxvif)
1571 			return -EINVAL;
1572 		read_lock(&mrt_lock);
1573 		vif = &mrt->vif_table[vr.vifi];
1574 		if (VIF_EXISTS(mrt, vr.vifi)) {
1575 			vr.icount = vif->pkt_in;
1576 			vr.ocount = vif->pkt_out;
1577 			vr.ibytes = vif->bytes_in;
1578 			vr.obytes = vif->bytes_out;
1579 			read_unlock(&mrt_lock);
1580 
1581 			if (copy_to_user(arg, &vr, sizeof(vr)))
1582 				return -EFAULT;
1583 			return 0;
1584 		}
1585 		read_unlock(&mrt_lock);
1586 		return -EADDRNOTAVAIL;
1587 	case SIOCGETSGCNT:
1588 		if (copy_from_user(&sr, arg, sizeof(sr)))
1589 			return -EFAULT;
1590 
1591 		rcu_read_lock();
1592 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1593 		if (c) {
1594 			sr.pktcnt = c->mfc_un.res.pkt;
1595 			sr.bytecnt = c->mfc_un.res.bytes;
1596 			sr.wrong_if = c->mfc_un.res.wrong_if;
1597 			rcu_read_unlock();
1598 
1599 			if (copy_to_user(arg, &sr, sizeof(sr)))
1600 				return -EFAULT;
1601 			return 0;
1602 		}
1603 		rcu_read_unlock();
1604 		return -EADDRNOTAVAIL;
1605 	default:
1606 		return -ENOIOCTLCMD;
1607 	}
1608 }
1609 #endif
1610 
1611 
1612 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1613 {
1614 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1615 	struct net *net = dev_net(dev);
1616 	struct mr_table *mrt;
1617 	struct vif_device *v;
1618 	int ct;
1619 
1620 	if (event != NETDEV_UNREGISTER)
1621 		return NOTIFY_DONE;
1622 
1623 	ipmr_for_each_table(mrt, net) {
1624 		v = &mrt->vif_table[0];
1625 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1626 			if (v->dev == dev)
1627 				vif_delete(mrt, ct, 1, NULL);
1628 		}
1629 	}
1630 	return NOTIFY_DONE;
1631 }
1632 
1633 
1634 static struct notifier_block ip_mr_notifier = {
1635 	.notifier_call = ipmr_device_event,
1636 };
1637 
1638 /*
1639  *	Encapsulate a packet by attaching a valid IPIP header to it.
1640  *	This avoids tunnel drivers and other mess and gives us the speed so
1641  *	important for multicast video.
1642  */
1643 
1644 static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr)
1645 {
1646 	struct iphdr *iph;
1647 	const struct iphdr *old_iph = ip_hdr(skb);
1648 
1649 	skb_push(skb, sizeof(struct iphdr));
1650 	skb->transport_header = skb->network_header;
1651 	skb_reset_network_header(skb);
1652 	iph = ip_hdr(skb);
1653 
1654 	iph->version	=	4;
1655 	iph->tos	=	old_iph->tos;
1656 	iph->ttl	=	old_iph->ttl;
1657 	iph->frag_off	=	0;
1658 	iph->daddr	=	daddr;
1659 	iph->saddr	=	saddr;
1660 	iph->protocol	=	IPPROTO_IPIP;
1661 	iph->ihl	=	5;
1662 	iph->tot_len	=	htons(skb->len);
1663 	ip_select_ident(skb, skb_dst(skb), NULL);
1664 	ip_send_check(iph);
1665 
1666 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1667 	nf_reset(skb);
1668 }
1669 
1670 static inline int ipmr_forward_finish(struct sk_buff *skb)
1671 {
1672 	struct ip_options *opt = &(IPCB(skb)->opt);
1673 
1674 	IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
1675 	IP_ADD_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTOCTETS, skb->len);
1676 
1677 	if (unlikely(opt->optlen))
1678 		ip_forward_options(skb);
1679 
1680 	return dst_output(skb);
1681 }
1682 
1683 /*
1684  *	Processing handlers for ipmr_forward
1685  */
1686 
1687 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1688 			    struct sk_buff *skb, struct mfc_cache *c, int vifi)
1689 {
1690 	const struct iphdr *iph = ip_hdr(skb);
1691 	struct vif_device *vif = &mrt->vif_table[vifi];
1692 	struct net_device *dev;
1693 	struct rtable *rt;
1694 	struct flowi4 fl4;
1695 	int    encap = 0;
1696 
1697 	if (vif->dev == NULL)
1698 		goto out_free;
1699 
1700 #ifdef CONFIG_IP_PIMSM
1701 	if (vif->flags & VIFF_REGISTER) {
1702 		vif->pkt_out++;
1703 		vif->bytes_out += skb->len;
1704 		vif->dev->stats.tx_bytes += skb->len;
1705 		vif->dev->stats.tx_packets++;
1706 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1707 		goto out_free;
1708 	}
1709 #endif
1710 
1711 	if (vif->flags & VIFF_TUNNEL) {
1712 		rt = ip_route_output_ports(net, &fl4, NULL,
1713 					   vif->remote, vif->local,
1714 					   0, 0,
1715 					   IPPROTO_IPIP,
1716 					   RT_TOS(iph->tos), vif->link);
1717 		if (IS_ERR(rt))
1718 			goto out_free;
1719 		encap = sizeof(struct iphdr);
1720 	} else {
1721 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1722 					   0, 0,
1723 					   IPPROTO_IPIP,
1724 					   RT_TOS(iph->tos), vif->link);
1725 		if (IS_ERR(rt))
1726 			goto out_free;
1727 	}
1728 
1729 	dev = rt->dst.dev;
1730 
1731 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1732 		/* Do not fragment multicasts. Alas, IPv4 does not
1733 		 * allow to send ICMP, so that packets will disappear
1734 		 * to blackhole.
1735 		 */
1736 
1737 		IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
1738 		ip_rt_put(rt);
1739 		goto out_free;
1740 	}
1741 
1742 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1743 
1744 	if (skb_cow(skb, encap)) {
1745 		ip_rt_put(rt);
1746 		goto out_free;
1747 	}
1748 
1749 	vif->pkt_out++;
1750 	vif->bytes_out += skb->len;
1751 
1752 	skb_dst_drop(skb);
1753 	skb_dst_set(skb, &rt->dst);
1754 	ip_decrease_ttl(ip_hdr(skb));
1755 
1756 	/* FIXME: forward and output firewalls used to be called here.
1757 	 * What do we do with netfilter? -- RR
1758 	 */
1759 	if (vif->flags & VIFF_TUNNEL) {
1760 		ip_encap(skb, vif->local, vif->remote);
1761 		/* FIXME: extra output firewall step used to be here. --RR */
1762 		vif->dev->stats.tx_packets++;
1763 		vif->dev->stats.tx_bytes += skb->len;
1764 	}
1765 
1766 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1767 
1768 	/*
1769 	 * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1770 	 * not only before forwarding, but after forwarding on all output
1771 	 * interfaces. It is clear, if mrouter runs a multicasting
1772 	 * program, it should receive packets not depending to what interface
1773 	 * program is joined.
1774 	 * If we will not make it, the program will have to join on all
1775 	 * interfaces. On the other hand, multihoming host (or router, but
1776 	 * not mrouter) cannot join to more than one interface - it will
1777 	 * result in receiving multiple packets.
1778 	 */
1779 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, skb, skb->dev, dev,
1780 		ipmr_forward_finish);
1781 	return;
1782 
1783 out_free:
1784 	kfree_skb(skb);
1785 }
1786 
1787 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1788 {
1789 	int ct;
1790 
1791 	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1792 		if (mrt->vif_table[ct].dev == dev)
1793 			break;
1794 	}
1795 	return ct;
1796 }
1797 
1798 /* "local" means that we should preserve one skb (for local delivery) */
1799 
1800 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
1801 			  struct sk_buff *skb, struct mfc_cache *cache,
1802 			  int local)
1803 {
1804 	int psend = -1;
1805 	int vif, ct;
1806 	int true_vifi = ipmr_find_vif(mrt, skb->dev);
1807 
1808 	vif = cache->mfc_parent;
1809 	cache->mfc_un.res.pkt++;
1810 	cache->mfc_un.res.bytes += skb->len;
1811 
1812 	if (cache->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
1813 		struct mfc_cache *cache_proxy;
1814 
1815 		/* For an (*,G) entry, we only check that the incomming
1816 		 * interface is part of the static tree.
1817 		 */
1818 		cache_proxy = ipmr_cache_find_any_parent(mrt, vif);
1819 		if (cache_proxy &&
1820 		    cache_proxy->mfc_un.res.ttls[true_vifi] < 255)
1821 			goto forward;
1822 	}
1823 
1824 	/*
1825 	 * Wrong interface: drop packet and (maybe) send PIM assert.
1826 	 */
1827 	if (mrt->vif_table[vif].dev != skb->dev) {
1828 		if (rt_is_output_route(skb_rtable(skb))) {
1829 			/* It is our own packet, looped back.
1830 			 * Very complicated situation...
1831 			 *
1832 			 * The best workaround until routing daemons will be
1833 			 * fixed is not to redistribute packet, if it was
1834 			 * send through wrong interface. It means, that
1835 			 * multicast applications WILL NOT work for
1836 			 * (S,G), which have default multicast route pointing
1837 			 * to wrong oif. In any case, it is not a good
1838 			 * idea to use multicasting applications on router.
1839 			 */
1840 			goto dont_forward;
1841 		}
1842 
1843 		cache->mfc_un.res.wrong_if++;
1844 
1845 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
1846 		    /* pimsm uses asserts, when switching from RPT to SPT,
1847 		     * so that we cannot check that packet arrived on an oif.
1848 		     * It is bad, but otherwise we would need to move pretty
1849 		     * large chunk of pimd to kernel. Ough... --ANK
1850 		     */
1851 		    (mrt->mroute_do_pim ||
1852 		     cache->mfc_un.res.ttls[true_vifi] < 255) &&
1853 		    time_after(jiffies,
1854 			       cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1855 			cache->mfc_un.res.last_assert = jiffies;
1856 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1857 		}
1858 		goto dont_forward;
1859 	}
1860 
1861 forward:
1862 	mrt->vif_table[vif].pkt_in++;
1863 	mrt->vif_table[vif].bytes_in += skb->len;
1864 
1865 	/*
1866 	 *	Forward the frame
1867 	 */
1868 	if (cache->mfc_origin == htonl(INADDR_ANY) &&
1869 	    cache->mfc_mcastgrp == htonl(INADDR_ANY)) {
1870 		if (true_vifi >= 0 &&
1871 		    true_vifi != cache->mfc_parent &&
1872 		    ip_hdr(skb)->ttl >
1873 				cache->mfc_un.res.ttls[cache->mfc_parent]) {
1874 			/* It's an (*,*) entry and the packet is not coming from
1875 			 * the upstream: forward the packet to the upstream
1876 			 * only.
1877 			 */
1878 			psend = cache->mfc_parent;
1879 			goto last_forward;
1880 		}
1881 		goto dont_forward;
1882 	}
1883 	for (ct = cache->mfc_un.res.maxvif - 1;
1884 	     ct >= cache->mfc_un.res.minvif; ct--) {
1885 		/* For (*,G) entry, don't forward to the incoming interface */
1886 		if ((cache->mfc_origin != htonl(INADDR_ANY) ||
1887 		     ct != true_vifi) &&
1888 		    ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1889 			if (psend != -1) {
1890 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1891 
1892 				if (skb2)
1893 					ipmr_queue_xmit(net, mrt, skb2, cache,
1894 							psend);
1895 			}
1896 			psend = ct;
1897 		}
1898 	}
1899 last_forward:
1900 	if (psend != -1) {
1901 		if (local) {
1902 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1903 
1904 			if (skb2)
1905 				ipmr_queue_xmit(net, mrt, skb2, cache, psend);
1906 		} else {
1907 			ipmr_queue_xmit(net, mrt, skb, cache, psend);
1908 			return;
1909 		}
1910 	}
1911 
1912 dont_forward:
1913 	if (!local)
1914 		kfree_skb(skb);
1915 }
1916 
1917 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
1918 {
1919 	struct rtable *rt = skb_rtable(skb);
1920 	struct iphdr *iph = ip_hdr(skb);
1921 	struct flowi4 fl4 = {
1922 		.daddr = iph->daddr,
1923 		.saddr = iph->saddr,
1924 		.flowi4_tos = RT_TOS(iph->tos),
1925 		.flowi4_oif = (rt_is_output_route(rt) ?
1926 			       skb->dev->ifindex : 0),
1927 		.flowi4_iif = (rt_is_output_route(rt) ?
1928 			       LOOPBACK_IFINDEX :
1929 			       skb->dev->ifindex),
1930 		.flowi4_mark = skb->mark,
1931 	};
1932 	struct mr_table *mrt;
1933 	int err;
1934 
1935 	err = ipmr_fib_lookup(net, &fl4, &mrt);
1936 	if (err)
1937 		return ERR_PTR(err);
1938 	return mrt;
1939 }
1940 
1941 /*
1942  *	Multicast packets for forwarding arrive here
1943  *	Called with rcu_read_lock();
1944  */
1945 
1946 int ip_mr_input(struct sk_buff *skb)
1947 {
1948 	struct mfc_cache *cache;
1949 	struct net *net = dev_net(skb->dev);
1950 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
1951 	struct mr_table *mrt;
1952 
1953 	/* Packet is looped back after forward, it should not be
1954 	 * forwarded second time, but still can be delivered locally.
1955 	 */
1956 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
1957 		goto dont_forward;
1958 
1959 	mrt = ipmr_rt_fib_lookup(net, skb);
1960 	if (IS_ERR(mrt)) {
1961 		kfree_skb(skb);
1962 		return PTR_ERR(mrt);
1963 	}
1964 	if (!local) {
1965 		if (IPCB(skb)->opt.router_alert) {
1966 			if (ip_call_ra_chain(skb))
1967 				return 0;
1968 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
1969 			/* IGMPv1 (and broken IGMPv2 implementations sort of
1970 			 * Cisco IOS <= 11.2(8)) do not put router alert
1971 			 * option to IGMP packets destined to routable
1972 			 * groups. It is very bad, because it means
1973 			 * that we can forward NO IGMP messages.
1974 			 */
1975 			struct sock *mroute_sk;
1976 
1977 			mroute_sk = rcu_dereference(mrt->mroute_sk);
1978 			if (mroute_sk) {
1979 				nf_reset(skb);
1980 				raw_rcv(mroute_sk, skb);
1981 				return 0;
1982 			}
1983 		    }
1984 	}
1985 
1986 	/* already under rcu_read_lock() */
1987 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
1988 	if (cache == NULL) {
1989 		int vif = ipmr_find_vif(mrt, skb->dev);
1990 
1991 		if (vif >= 0)
1992 			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
1993 						    vif);
1994 	}
1995 
1996 	/*
1997 	 *	No usable cache entry
1998 	 */
1999 	if (cache == NULL) {
2000 		int vif;
2001 
2002 		if (local) {
2003 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2004 			ip_local_deliver(skb);
2005 			if (skb2 == NULL)
2006 				return -ENOBUFS;
2007 			skb = skb2;
2008 		}
2009 
2010 		read_lock(&mrt_lock);
2011 		vif = ipmr_find_vif(mrt, skb->dev);
2012 		if (vif >= 0) {
2013 			int err2 = ipmr_cache_unresolved(mrt, vif, skb);
2014 			read_unlock(&mrt_lock);
2015 
2016 			return err2;
2017 		}
2018 		read_unlock(&mrt_lock);
2019 		kfree_skb(skb);
2020 		return -ENODEV;
2021 	}
2022 
2023 	read_lock(&mrt_lock);
2024 	ip_mr_forward(net, mrt, skb, cache, local);
2025 	read_unlock(&mrt_lock);
2026 
2027 	if (local)
2028 		return ip_local_deliver(skb);
2029 
2030 	return 0;
2031 
2032 dont_forward:
2033 	if (local)
2034 		return ip_local_deliver(skb);
2035 	kfree_skb(skb);
2036 	return 0;
2037 }
2038 
2039 #ifdef CONFIG_IP_PIMSM
2040 /* called with rcu_read_lock() */
2041 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
2042 		     unsigned int pimlen)
2043 {
2044 	struct net_device *reg_dev = NULL;
2045 	struct iphdr *encap;
2046 
2047 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
2048 	/*
2049 	 * Check that:
2050 	 * a. packet is really sent to a multicast group
2051 	 * b. packet is not a NULL-REGISTER
2052 	 * c. packet is not truncated
2053 	 */
2054 	if (!ipv4_is_multicast(encap->daddr) ||
2055 	    encap->tot_len == 0 ||
2056 	    ntohs(encap->tot_len) + pimlen > skb->len)
2057 		return 1;
2058 
2059 	read_lock(&mrt_lock);
2060 	if (mrt->mroute_reg_vif_num >= 0)
2061 		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
2062 	read_unlock(&mrt_lock);
2063 
2064 	if (reg_dev == NULL)
2065 		return 1;
2066 
2067 	skb->mac_header = skb->network_header;
2068 	skb_pull(skb, (u8 *)encap - skb->data);
2069 	skb_reset_network_header(skb);
2070 	skb->protocol = htons(ETH_P_IP);
2071 	skb->ip_summed = CHECKSUM_NONE;
2072 
2073 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
2074 
2075 	netif_rx(skb);
2076 
2077 	return NET_RX_SUCCESS;
2078 }
2079 #endif
2080 
2081 #ifdef CONFIG_IP_PIMSM_V1
2082 /*
2083  * Handle IGMP messages of PIMv1
2084  */
2085 
2086 int pim_rcv_v1(struct sk_buff *skb)
2087 {
2088 	struct igmphdr *pim;
2089 	struct net *net = dev_net(skb->dev);
2090 	struct mr_table *mrt;
2091 
2092 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2093 		goto drop;
2094 
2095 	pim = igmp_hdr(skb);
2096 
2097 	mrt = ipmr_rt_fib_lookup(net, skb);
2098 	if (IS_ERR(mrt))
2099 		goto drop;
2100 	if (!mrt->mroute_do_pim ||
2101 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2102 		goto drop;
2103 
2104 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2105 drop:
2106 		kfree_skb(skb);
2107 	}
2108 	return 0;
2109 }
2110 #endif
2111 
2112 #ifdef CONFIG_IP_PIMSM_V2
2113 static int pim_rcv(struct sk_buff *skb)
2114 {
2115 	struct pimreghdr *pim;
2116 	struct net *net = dev_net(skb->dev);
2117 	struct mr_table *mrt;
2118 
2119 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2120 		goto drop;
2121 
2122 	pim = (struct pimreghdr *)skb_transport_header(skb);
2123 	if (pim->type != ((PIM_VERSION << 4) | (PIM_REGISTER)) ||
2124 	    (pim->flags & PIM_NULL_REGISTER) ||
2125 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2126 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2127 		goto drop;
2128 
2129 	mrt = ipmr_rt_fib_lookup(net, skb);
2130 	if (IS_ERR(mrt))
2131 		goto drop;
2132 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2133 drop:
2134 		kfree_skb(skb);
2135 	}
2136 	return 0;
2137 }
2138 #endif
2139 
2140 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2141 			      struct mfc_cache *c, struct rtmsg *rtm)
2142 {
2143 	int ct;
2144 	struct rtnexthop *nhp;
2145 	struct nlattr *mp_attr;
2146 	struct rta_mfc_stats mfcs;
2147 
2148 	/* If cache is unresolved, don't try to parse IIF and OIF */
2149 	if (c->mfc_parent >= MAXVIFS)
2150 		return -ENOENT;
2151 
2152 	if (VIF_EXISTS(mrt, c->mfc_parent) &&
2153 	    nla_put_u32(skb, RTA_IIF, mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
2154 		return -EMSGSIZE;
2155 
2156 	if (!(mp_attr = nla_nest_start(skb, RTA_MULTIPATH)))
2157 		return -EMSGSIZE;
2158 
2159 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
2160 		if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
2161 			if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp)))) {
2162 				nla_nest_cancel(skb, mp_attr);
2163 				return -EMSGSIZE;
2164 			}
2165 
2166 			nhp->rtnh_flags = 0;
2167 			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
2168 			nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
2169 			nhp->rtnh_len = sizeof(*nhp);
2170 		}
2171 	}
2172 
2173 	nla_nest_end(skb, mp_attr);
2174 
2175 	mfcs.mfcs_packets = c->mfc_un.res.pkt;
2176 	mfcs.mfcs_bytes = c->mfc_un.res.bytes;
2177 	mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
2178 	if (nla_put(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs) < 0)
2179 		return -EMSGSIZE;
2180 
2181 	rtm->rtm_type = RTN_MULTICAST;
2182 	return 1;
2183 }
2184 
2185 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2186 		   __be32 saddr, __be32 daddr,
2187 		   struct rtmsg *rtm, int nowait)
2188 {
2189 	struct mfc_cache *cache;
2190 	struct mr_table *mrt;
2191 	int err;
2192 
2193 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2194 	if (mrt == NULL)
2195 		return -ENOENT;
2196 
2197 	rcu_read_lock();
2198 	cache = ipmr_cache_find(mrt, saddr, daddr);
2199 	if (cache == NULL && skb->dev) {
2200 		int vif = ipmr_find_vif(mrt, skb->dev);
2201 
2202 		if (vif >= 0)
2203 			cache = ipmr_cache_find_any(mrt, daddr, vif);
2204 	}
2205 	if (cache == NULL) {
2206 		struct sk_buff *skb2;
2207 		struct iphdr *iph;
2208 		struct net_device *dev;
2209 		int vif = -1;
2210 
2211 		if (nowait) {
2212 			rcu_read_unlock();
2213 			return -EAGAIN;
2214 		}
2215 
2216 		dev = skb->dev;
2217 		read_lock(&mrt_lock);
2218 		if (dev)
2219 			vif = ipmr_find_vif(mrt, dev);
2220 		if (vif < 0) {
2221 			read_unlock(&mrt_lock);
2222 			rcu_read_unlock();
2223 			return -ENODEV;
2224 		}
2225 		skb2 = skb_clone(skb, GFP_ATOMIC);
2226 		if (!skb2) {
2227 			read_unlock(&mrt_lock);
2228 			rcu_read_unlock();
2229 			return -ENOMEM;
2230 		}
2231 
2232 		skb_push(skb2, sizeof(struct iphdr));
2233 		skb_reset_network_header(skb2);
2234 		iph = ip_hdr(skb2);
2235 		iph->ihl = sizeof(struct iphdr) >> 2;
2236 		iph->saddr = saddr;
2237 		iph->daddr = daddr;
2238 		iph->version = 0;
2239 		err = ipmr_cache_unresolved(mrt, vif, skb2);
2240 		read_unlock(&mrt_lock);
2241 		rcu_read_unlock();
2242 		return err;
2243 	}
2244 
2245 	read_lock(&mrt_lock);
2246 	if (!nowait && (rtm->rtm_flags & RTM_F_NOTIFY))
2247 		cache->mfc_flags |= MFC_NOTIFY;
2248 	err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2249 	read_unlock(&mrt_lock);
2250 	rcu_read_unlock();
2251 	return err;
2252 }
2253 
2254 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2255 			    u32 portid, u32 seq, struct mfc_cache *c, int cmd)
2256 {
2257 	struct nlmsghdr *nlh;
2258 	struct rtmsg *rtm;
2259 	int err;
2260 
2261 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), NLM_F_MULTI);
2262 	if (nlh == NULL)
2263 		return -EMSGSIZE;
2264 
2265 	rtm = nlmsg_data(nlh);
2266 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2267 	rtm->rtm_dst_len  = 32;
2268 	rtm->rtm_src_len  = 32;
2269 	rtm->rtm_tos      = 0;
2270 	rtm->rtm_table    = mrt->id;
2271 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2272 		goto nla_put_failure;
2273 	rtm->rtm_type     = RTN_MULTICAST;
2274 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2275 	if (c->mfc_flags & MFC_STATIC)
2276 		rtm->rtm_protocol = RTPROT_STATIC;
2277 	else
2278 		rtm->rtm_protocol = RTPROT_MROUTED;
2279 	rtm->rtm_flags    = 0;
2280 
2281 	if (nla_put_be32(skb, RTA_SRC, c->mfc_origin) ||
2282 	    nla_put_be32(skb, RTA_DST, c->mfc_mcastgrp))
2283 		goto nla_put_failure;
2284 	err = __ipmr_fill_mroute(mrt, skb, c, rtm);
2285 	/* do not break the dump if cache is unresolved */
2286 	if (err < 0 && err != -ENOENT)
2287 		goto nla_put_failure;
2288 
2289 	return nlmsg_end(skb, nlh);
2290 
2291 nla_put_failure:
2292 	nlmsg_cancel(skb, nlh);
2293 	return -EMSGSIZE;
2294 }
2295 
2296 static size_t mroute_msgsize(bool unresolved, int maxvif)
2297 {
2298 	size_t len =
2299 		NLMSG_ALIGN(sizeof(struct rtmsg))
2300 		+ nla_total_size(4)	/* RTA_TABLE */
2301 		+ nla_total_size(4)	/* RTA_SRC */
2302 		+ nla_total_size(4)	/* RTA_DST */
2303 		;
2304 
2305 	if (!unresolved)
2306 		len = len
2307 		      + nla_total_size(4)	/* RTA_IIF */
2308 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2309 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2310 						/* RTA_MFC_STATS */
2311 		      + nla_total_size(sizeof(struct rta_mfc_stats))
2312 		;
2313 
2314 	return len;
2315 }
2316 
2317 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2318 				 int cmd)
2319 {
2320 	struct net *net = read_pnet(&mrt->net);
2321 	struct sk_buff *skb;
2322 	int err = -ENOBUFS;
2323 
2324 	skb = nlmsg_new(mroute_msgsize(mfc->mfc_parent >= MAXVIFS, mrt->maxvif),
2325 			GFP_ATOMIC);
2326 	if (skb == NULL)
2327 		goto errout;
2328 
2329 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd);
2330 	if (err < 0)
2331 		goto errout;
2332 
2333 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2334 	return;
2335 
2336 errout:
2337 	kfree_skb(skb);
2338 	if (err < 0)
2339 		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2340 }
2341 
2342 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2343 {
2344 	struct net *net = sock_net(skb->sk);
2345 	struct mr_table *mrt;
2346 	struct mfc_cache *mfc;
2347 	unsigned int t = 0, s_t;
2348 	unsigned int h = 0, s_h;
2349 	unsigned int e = 0, s_e;
2350 
2351 	s_t = cb->args[0];
2352 	s_h = cb->args[1];
2353 	s_e = cb->args[2];
2354 
2355 	rcu_read_lock();
2356 	ipmr_for_each_table(mrt, net) {
2357 		if (t < s_t)
2358 			goto next_table;
2359 		if (t > s_t)
2360 			s_h = 0;
2361 		for (h = s_h; h < MFC_LINES; h++) {
2362 			list_for_each_entry_rcu(mfc, &mrt->mfc_cache_array[h], list) {
2363 				if (e < s_e)
2364 					goto next_entry;
2365 				if (ipmr_fill_mroute(mrt, skb,
2366 						     NETLINK_CB(cb->skb).portid,
2367 						     cb->nlh->nlmsg_seq,
2368 						     mfc, RTM_NEWROUTE) < 0)
2369 					goto done;
2370 next_entry:
2371 				e++;
2372 			}
2373 			e = s_e = 0;
2374 		}
2375 		spin_lock_bh(&mfc_unres_lock);
2376 		list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
2377 			if (e < s_e)
2378 				goto next_entry2;
2379 			if (ipmr_fill_mroute(mrt, skb,
2380 					     NETLINK_CB(cb->skb).portid,
2381 					     cb->nlh->nlmsg_seq,
2382 					     mfc, RTM_NEWROUTE) < 0) {
2383 				spin_unlock_bh(&mfc_unres_lock);
2384 				goto done;
2385 			}
2386 next_entry2:
2387 			e++;
2388 		}
2389 		spin_unlock_bh(&mfc_unres_lock);
2390 		e = s_e = 0;
2391 		s_h = 0;
2392 next_table:
2393 		t++;
2394 	}
2395 done:
2396 	rcu_read_unlock();
2397 
2398 	cb->args[2] = e;
2399 	cb->args[1] = h;
2400 	cb->args[0] = t;
2401 
2402 	return skb->len;
2403 }
2404 
2405 #ifdef CONFIG_PROC_FS
2406 /*
2407  *	The /proc interfaces to multicast routing :
2408  *	/proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2409  */
2410 struct ipmr_vif_iter {
2411 	struct seq_net_private p;
2412 	struct mr_table *mrt;
2413 	int ct;
2414 };
2415 
2416 static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2417 					   struct ipmr_vif_iter *iter,
2418 					   loff_t pos)
2419 {
2420 	struct mr_table *mrt = iter->mrt;
2421 
2422 	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2423 		if (!VIF_EXISTS(mrt, iter->ct))
2424 			continue;
2425 		if (pos-- == 0)
2426 			return &mrt->vif_table[iter->ct];
2427 	}
2428 	return NULL;
2429 }
2430 
2431 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2432 	__acquires(mrt_lock)
2433 {
2434 	struct ipmr_vif_iter *iter = seq->private;
2435 	struct net *net = seq_file_net(seq);
2436 	struct mr_table *mrt;
2437 
2438 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2439 	if (mrt == NULL)
2440 		return ERR_PTR(-ENOENT);
2441 
2442 	iter->mrt = mrt;
2443 
2444 	read_lock(&mrt_lock);
2445 	return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2446 		: SEQ_START_TOKEN;
2447 }
2448 
2449 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2450 {
2451 	struct ipmr_vif_iter *iter = seq->private;
2452 	struct net *net = seq_file_net(seq);
2453 	struct mr_table *mrt = iter->mrt;
2454 
2455 	++*pos;
2456 	if (v == SEQ_START_TOKEN)
2457 		return ipmr_vif_seq_idx(net, iter, 0);
2458 
2459 	while (++iter->ct < mrt->maxvif) {
2460 		if (!VIF_EXISTS(mrt, iter->ct))
2461 			continue;
2462 		return &mrt->vif_table[iter->ct];
2463 	}
2464 	return NULL;
2465 }
2466 
2467 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2468 	__releases(mrt_lock)
2469 {
2470 	read_unlock(&mrt_lock);
2471 }
2472 
2473 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2474 {
2475 	struct ipmr_vif_iter *iter = seq->private;
2476 	struct mr_table *mrt = iter->mrt;
2477 
2478 	if (v == SEQ_START_TOKEN) {
2479 		seq_puts(seq,
2480 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2481 	} else {
2482 		const struct vif_device *vif = v;
2483 		const char *name =  vif->dev ? vif->dev->name : "none";
2484 
2485 		seq_printf(seq,
2486 			   "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2487 			   vif - mrt->vif_table,
2488 			   name, vif->bytes_in, vif->pkt_in,
2489 			   vif->bytes_out, vif->pkt_out,
2490 			   vif->flags, vif->local, vif->remote);
2491 	}
2492 	return 0;
2493 }
2494 
2495 static const struct seq_operations ipmr_vif_seq_ops = {
2496 	.start = ipmr_vif_seq_start,
2497 	.next  = ipmr_vif_seq_next,
2498 	.stop  = ipmr_vif_seq_stop,
2499 	.show  = ipmr_vif_seq_show,
2500 };
2501 
2502 static int ipmr_vif_open(struct inode *inode, struct file *file)
2503 {
2504 	return seq_open_net(inode, file, &ipmr_vif_seq_ops,
2505 			    sizeof(struct ipmr_vif_iter));
2506 }
2507 
2508 static const struct file_operations ipmr_vif_fops = {
2509 	.owner	 = THIS_MODULE,
2510 	.open    = ipmr_vif_open,
2511 	.read    = seq_read,
2512 	.llseek  = seq_lseek,
2513 	.release = seq_release_net,
2514 };
2515 
2516 struct ipmr_mfc_iter {
2517 	struct seq_net_private p;
2518 	struct mr_table *mrt;
2519 	struct list_head *cache;
2520 	int ct;
2521 };
2522 
2523 
2524 static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
2525 					  struct ipmr_mfc_iter *it, loff_t pos)
2526 {
2527 	struct mr_table *mrt = it->mrt;
2528 	struct mfc_cache *mfc;
2529 
2530 	rcu_read_lock();
2531 	for (it->ct = 0; it->ct < MFC_LINES; it->ct++) {
2532 		it->cache = &mrt->mfc_cache_array[it->ct];
2533 		list_for_each_entry_rcu(mfc, it->cache, list)
2534 			if (pos-- == 0)
2535 				return mfc;
2536 	}
2537 	rcu_read_unlock();
2538 
2539 	spin_lock_bh(&mfc_unres_lock);
2540 	it->cache = &mrt->mfc_unres_queue;
2541 	list_for_each_entry(mfc, it->cache, list)
2542 		if (pos-- == 0)
2543 			return mfc;
2544 	spin_unlock_bh(&mfc_unres_lock);
2545 
2546 	it->cache = NULL;
2547 	return NULL;
2548 }
2549 
2550 
2551 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2552 {
2553 	struct ipmr_mfc_iter *it = seq->private;
2554 	struct net *net = seq_file_net(seq);
2555 	struct mr_table *mrt;
2556 
2557 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2558 	if (mrt == NULL)
2559 		return ERR_PTR(-ENOENT);
2560 
2561 	it->mrt = mrt;
2562 	it->cache = NULL;
2563 	it->ct = 0;
2564 	return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
2565 		: SEQ_START_TOKEN;
2566 }
2567 
2568 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2569 {
2570 	struct mfc_cache *mfc = v;
2571 	struct ipmr_mfc_iter *it = seq->private;
2572 	struct net *net = seq_file_net(seq);
2573 	struct mr_table *mrt = it->mrt;
2574 
2575 	++*pos;
2576 
2577 	if (v == SEQ_START_TOKEN)
2578 		return ipmr_mfc_seq_idx(net, seq->private, 0);
2579 
2580 	if (mfc->list.next != it->cache)
2581 		return list_entry(mfc->list.next, struct mfc_cache, list);
2582 
2583 	if (it->cache == &mrt->mfc_unres_queue)
2584 		goto end_of_list;
2585 
2586 	BUG_ON(it->cache != &mrt->mfc_cache_array[it->ct]);
2587 
2588 	while (++it->ct < MFC_LINES) {
2589 		it->cache = &mrt->mfc_cache_array[it->ct];
2590 		if (list_empty(it->cache))
2591 			continue;
2592 		return list_first_entry(it->cache, struct mfc_cache, list);
2593 	}
2594 
2595 	/* exhausted cache_array, show unresolved */
2596 	rcu_read_unlock();
2597 	it->cache = &mrt->mfc_unres_queue;
2598 	it->ct = 0;
2599 
2600 	spin_lock_bh(&mfc_unres_lock);
2601 	if (!list_empty(it->cache))
2602 		return list_first_entry(it->cache, struct mfc_cache, list);
2603 
2604 end_of_list:
2605 	spin_unlock_bh(&mfc_unres_lock);
2606 	it->cache = NULL;
2607 
2608 	return NULL;
2609 }
2610 
2611 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
2612 {
2613 	struct ipmr_mfc_iter *it = seq->private;
2614 	struct mr_table *mrt = it->mrt;
2615 
2616 	if (it->cache == &mrt->mfc_unres_queue)
2617 		spin_unlock_bh(&mfc_unres_lock);
2618 	else if (it->cache == &mrt->mfc_cache_array[it->ct])
2619 		rcu_read_unlock();
2620 }
2621 
2622 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2623 {
2624 	int n;
2625 
2626 	if (v == SEQ_START_TOKEN) {
2627 		seq_puts(seq,
2628 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2629 	} else {
2630 		const struct mfc_cache *mfc = v;
2631 		const struct ipmr_mfc_iter *it = seq->private;
2632 		const struct mr_table *mrt = it->mrt;
2633 
2634 		seq_printf(seq, "%08X %08X %-3hd",
2635 			   (__force u32) mfc->mfc_mcastgrp,
2636 			   (__force u32) mfc->mfc_origin,
2637 			   mfc->mfc_parent);
2638 
2639 		if (it->cache != &mrt->mfc_unres_queue) {
2640 			seq_printf(seq, " %8lu %8lu %8lu",
2641 				   mfc->mfc_un.res.pkt,
2642 				   mfc->mfc_un.res.bytes,
2643 				   mfc->mfc_un.res.wrong_if);
2644 			for (n = mfc->mfc_un.res.minvif;
2645 			     n < mfc->mfc_un.res.maxvif; n++) {
2646 				if (VIF_EXISTS(mrt, n) &&
2647 				    mfc->mfc_un.res.ttls[n] < 255)
2648 					seq_printf(seq,
2649 					   " %2d:%-3d",
2650 					   n, mfc->mfc_un.res.ttls[n]);
2651 			}
2652 		} else {
2653 			/* unresolved mfc_caches don't contain
2654 			 * pkt, bytes and wrong_if values
2655 			 */
2656 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
2657 		}
2658 		seq_putc(seq, '\n');
2659 	}
2660 	return 0;
2661 }
2662 
2663 static const struct seq_operations ipmr_mfc_seq_ops = {
2664 	.start = ipmr_mfc_seq_start,
2665 	.next  = ipmr_mfc_seq_next,
2666 	.stop  = ipmr_mfc_seq_stop,
2667 	.show  = ipmr_mfc_seq_show,
2668 };
2669 
2670 static int ipmr_mfc_open(struct inode *inode, struct file *file)
2671 {
2672 	return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
2673 			    sizeof(struct ipmr_mfc_iter));
2674 }
2675 
2676 static const struct file_operations ipmr_mfc_fops = {
2677 	.owner	 = THIS_MODULE,
2678 	.open    = ipmr_mfc_open,
2679 	.read    = seq_read,
2680 	.llseek  = seq_lseek,
2681 	.release = seq_release_net,
2682 };
2683 #endif
2684 
2685 #ifdef CONFIG_IP_PIMSM_V2
2686 static const struct net_protocol pim_protocol = {
2687 	.handler	=	pim_rcv,
2688 	.netns_ok	=	1,
2689 };
2690 #endif
2691 
2692 
2693 /*
2694  *	Setup for IP multicast routing
2695  */
2696 static int __net_init ipmr_net_init(struct net *net)
2697 {
2698 	int err;
2699 
2700 	err = ipmr_rules_init(net);
2701 	if (err < 0)
2702 		goto fail;
2703 
2704 #ifdef CONFIG_PROC_FS
2705 	err = -ENOMEM;
2706 	if (!proc_create("ip_mr_vif", 0, net->proc_net, &ipmr_vif_fops))
2707 		goto proc_vif_fail;
2708 	if (!proc_create("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_fops))
2709 		goto proc_cache_fail;
2710 #endif
2711 	return 0;
2712 
2713 #ifdef CONFIG_PROC_FS
2714 proc_cache_fail:
2715 	remove_proc_entry("ip_mr_vif", net->proc_net);
2716 proc_vif_fail:
2717 	ipmr_rules_exit(net);
2718 #endif
2719 fail:
2720 	return err;
2721 }
2722 
2723 static void __net_exit ipmr_net_exit(struct net *net)
2724 {
2725 #ifdef CONFIG_PROC_FS
2726 	remove_proc_entry("ip_mr_cache", net->proc_net);
2727 	remove_proc_entry("ip_mr_vif", net->proc_net);
2728 #endif
2729 	ipmr_rules_exit(net);
2730 }
2731 
2732 static struct pernet_operations ipmr_net_ops = {
2733 	.init = ipmr_net_init,
2734 	.exit = ipmr_net_exit,
2735 };
2736 
2737 int __init ip_mr_init(void)
2738 {
2739 	int err;
2740 
2741 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
2742 				       sizeof(struct mfc_cache),
2743 				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
2744 				       NULL);
2745 	if (!mrt_cachep)
2746 		return -ENOMEM;
2747 
2748 	err = register_pernet_subsys(&ipmr_net_ops);
2749 	if (err)
2750 		goto reg_pernet_fail;
2751 
2752 	err = register_netdevice_notifier(&ip_mr_notifier);
2753 	if (err)
2754 		goto reg_notif_fail;
2755 #ifdef CONFIG_IP_PIMSM_V2
2756 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
2757 		pr_err("%s: can't add PIM protocol\n", __func__);
2758 		err = -EAGAIN;
2759 		goto add_proto_fail;
2760 	}
2761 #endif
2762 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
2763 		      NULL, ipmr_rtm_dumproute, NULL);
2764 	return 0;
2765 
2766 #ifdef CONFIG_IP_PIMSM_V2
2767 add_proto_fail:
2768 	unregister_netdevice_notifier(&ip_mr_notifier);
2769 #endif
2770 reg_notif_fail:
2771 	unregister_pernet_subsys(&ipmr_net_ops);
2772 reg_pernet_fail:
2773 	kmem_cache_destroy(mrt_cachep);
2774 	return err;
2775 }
2776