xref: /linux/net/ipv4/ipmr.c (revision a5d9265e017f081f0dc133c0e2f45103d027b874)
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 <linux/uaccess.h>
30 #include <linux/types.h>
31 #include <linux/cache.h>
32 #include <linux/capability.h>
33 #include <linux/errno.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/icmp.h>
56 #include <net/udp.h>
57 #include <net/raw.h>
58 #include <linux/notifier.h>
59 #include <linux/if_arp.h>
60 #include <linux/netfilter_ipv4.h>
61 #include <linux/compat.h>
62 #include <linux/export.h>
63 #include <linux/rhashtable.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 #include <net/nexthop.h>
70 
71 #include <linux/nospec.h>
72 
73 struct ipmr_rule {
74 	struct fib_rule		common;
75 };
76 
77 struct ipmr_result {
78 	struct mr_table		*mrt;
79 };
80 
81 /* Big lock, protecting vif table, mrt cache and mroute socket state.
82  * Note that the changes are semaphored via rtnl_lock.
83  */
84 
85 static DEFINE_RWLOCK(mrt_lock);
86 
87 /* Multicast router control variables */
88 
89 /* Special spinlock for queue of unresolved entries */
90 static DEFINE_SPINLOCK(mfc_unres_lock);
91 
92 /* We return to original Alan's scheme. Hash table of resolved
93  * entries is changed only in process context and protected
94  * with weak lock mrt_lock. Queue of unresolved entries is protected
95  * with strong spinlock mfc_unres_lock.
96  *
97  * In this case data path is free of exclusive locks at all.
98  */
99 
100 static struct kmem_cache *mrt_cachep __ro_after_init;
101 
102 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
103 static void ipmr_free_table(struct mr_table *mrt);
104 
105 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
106 			  struct net_device *dev, struct sk_buff *skb,
107 			  struct mfc_cache *cache, int local);
108 static int ipmr_cache_report(struct mr_table *mrt,
109 			     struct sk_buff *pkt, vifi_t vifi, int assert);
110 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
111 				 int cmd);
112 static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
113 static void mroute_clean_tables(struct mr_table *mrt, bool all);
114 static void ipmr_expire_process(struct timer_list *t);
115 
116 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
117 #define ipmr_for_each_table(mrt, net) \
118 	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
119 
120 static struct mr_table *ipmr_mr_table_iter(struct net *net,
121 					   struct mr_table *mrt)
122 {
123 	struct mr_table *ret;
124 
125 	if (!mrt)
126 		ret = list_entry_rcu(net->ipv4.mr_tables.next,
127 				     struct mr_table, list);
128 	else
129 		ret = list_entry_rcu(mrt->list.next,
130 				     struct mr_table, list);
131 
132 	if (&ret->list == &net->ipv4.mr_tables)
133 		return NULL;
134 	return ret;
135 }
136 
137 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
138 {
139 	struct mr_table *mrt;
140 
141 	ipmr_for_each_table(mrt, net) {
142 		if (mrt->id == id)
143 			return mrt;
144 	}
145 	return NULL;
146 }
147 
148 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
149 			   struct mr_table **mrt)
150 {
151 	int err;
152 	struct ipmr_result res;
153 	struct fib_lookup_arg arg = {
154 		.result = &res,
155 		.flags = FIB_LOOKUP_NOREF,
156 	};
157 
158 	/* update flow if oif or iif point to device enslaved to l3mdev */
159 	l3mdev_update_flow(net, flowi4_to_flowi(flp4));
160 
161 	err = fib_rules_lookup(net->ipv4.mr_rules_ops,
162 			       flowi4_to_flowi(flp4), 0, &arg);
163 	if (err < 0)
164 		return err;
165 	*mrt = res.mrt;
166 	return 0;
167 }
168 
169 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
170 			    int flags, struct fib_lookup_arg *arg)
171 {
172 	struct ipmr_result *res = arg->result;
173 	struct mr_table *mrt;
174 
175 	switch (rule->action) {
176 	case FR_ACT_TO_TBL:
177 		break;
178 	case FR_ACT_UNREACHABLE:
179 		return -ENETUNREACH;
180 	case FR_ACT_PROHIBIT:
181 		return -EACCES;
182 	case FR_ACT_BLACKHOLE:
183 	default:
184 		return -EINVAL;
185 	}
186 
187 	arg->table = fib_rule_get_table(rule, arg);
188 
189 	mrt = ipmr_get_table(rule->fr_net, arg->table);
190 	if (!mrt)
191 		return -EAGAIN;
192 	res->mrt = mrt;
193 	return 0;
194 }
195 
196 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
197 {
198 	return 1;
199 }
200 
201 static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
202 	FRA_GENERIC_POLICY,
203 };
204 
205 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
206 			       struct fib_rule_hdr *frh, struct nlattr **tb,
207 			       struct netlink_ext_ack *extack)
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 	.fill		= ipmr_rule_fill,
236 	.nlgroup	= RTNLGRP_IPV4_RULE,
237 	.policy		= ipmr_rule_policy,
238 	.owner		= THIS_MODULE,
239 };
240 
241 static int __net_init ipmr_rules_init(struct net *net)
242 {
243 	struct fib_rules_ops *ops;
244 	struct mr_table *mrt;
245 	int err;
246 
247 	ops = fib_rules_register(&ipmr_rules_ops_template, net);
248 	if (IS_ERR(ops))
249 		return PTR_ERR(ops);
250 
251 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
252 
253 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
254 	if (IS_ERR(mrt)) {
255 		err = PTR_ERR(mrt);
256 		goto err1;
257 	}
258 
259 	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
260 	if (err < 0)
261 		goto err2;
262 
263 	net->ipv4.mr_rules_ops = ops;
264 	return 0;
265 
266 err2:
267 	ipmr_free_table(mrt);
268 err1:
269 	fib_rules_unregister(ops);
270 	return err;
271 }
272 
273 static void __net_exit ipmr_rules_exit(struct net *net)
274 {
275 	struct mr_table *mrt, *next;
276 
277 	rtnl_lock();
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 	rtnl_unlock();
284 }
285 
286 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb)
287 {
288 	return fib_rules_dump(net, nb, RTNL_FAMILY_IPMR);
289 }
290 
291 static unsigned int ipmr_rules_seq_read(struct net *net)
292 {
293 	return fib_rules_seq_read(net, RTNL_FAMILY_IPMR);
294 }
295 
296 bool ipmr_rule_default(const struct fib_rule *rule)
297 {
298 	return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
299 }
300 EXPORT_SYMBOL(ipmr_rule_default);
301 #else
302 #define ipmr_for_each_table(mrt, net) \
303 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
304 
305 static struct mr_table *ipmr_mr_table_iter(struct net *net,
306 					   struct mr_table *mrt)
307 {
308 	if (!mrt)
309 		return net->ipv4.mrt;
310 	return NULL;
311 }
312 
313 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
314 {
315 	return net->ipv4.mrt;
316 }
317 
318 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
319 			   struct mr_table **mrt)
320 {
321 	*mrt = net->ipv4.mrt;
322 	return 0;
323 }
324 
325 static int __net_init ipmr_rules_init(struct net *net)
326 {
327 	struct mr_table *mrt;
328 
329 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
330 	if (IS_ERR(mrt))
331 		return PTR_ERR(mrt);
332 	net->ipv4.mrt = mrt;
333 	return 0;
334 }
335 
336 static void __net_exit ipmr_rules_exit(struct net *net)
337 {
338 	rtnl_lock();
339 	ipmr_free_table(net->ipv4.mrt);
340 	net->ipv4.mrt = NULL;
341 	rtnl_unlock();
342 }
343 
344 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb)
345 {
346 	return 0;
347 }
348 
349 static unsigned int ipmr_rules_seq_read(struct net *net)
350 {
351 	return 0;
352 }
353 
354 bool ipmr_rule_default(const struct fib_rule *rule)
355 {
356 	return true;
357 }
358 EXPORT_SYMBOL(ipmr_rule_default);
359 #endif
360 
361 static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
362 				const void *ptr)
363 {
364 	const struct mfc_cache_cmp_arg *cmparg = arg->key;
365 	struct mfc_cache *c = (struct mfc_cache *)ptr;
366 
367 	return cmparg->mfc_mcastgrp != c->mfc_mcastgrp ||
368 	       cmparg->mfc_origin != c->mfc_origin;
369 }
370 
371 static const struct rhashtable_params ipmr_rht_params = {
372 	.head_offset = offsetof(struct mr_mfc, mnode),
373 	.key_offset = offsetof(struct mfc_cache, cmparg),
374 	.key_len = sizeof(struct mfc_cache_cmp_arg),
375 	.nelem_hint = 3,
376 	.locks_mul = 1,
377 	.obj_cmpfn = ipmr_hash_cmp,
378 	.automatic_shrinking = true,
379 };
380 
381 static void ipmr_new_table_set(struct mr_table *mrt,
382 			       struct net *net)
383 {
384 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
385 	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
386 #endif
387 }
388 
389 static struct mfc_cache_cmp_arg ipmr_mr_table_ops_cmparg_any = {
390 	.mfc_mcastgrp = htonl(INADDR_ANY),
391 	.mfc_origin = htonl(INADDR_ANY),
392 };
393 
394 static struct mr_table_ops ipmr_mr_table_ops = {
395 	.rht_params = &ipmr_rht_params,
396 	.cmparg_any = &ipmr_mr_table_ops_cmparg_any,
397 };
398 
399 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
400 {
401 	struct mr_table *mrt;
402 
403 	/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
404 	if (id != RT_TABLE_DEFAULT && id >= 1000000000)
405 		return ERR_PTR(-EINVAL);
406 
407 	mrt = ipmr_get_table(net, id);
408 	if (mrt)
409 		return mrt;
410 
411 	return mr_table_alloc(net, id, &ipmr_mr_table_ops,
412 			      ipmr_expire_process, ipmr_new_table_set);
413 }
414 
415 static void ipmr_free_table(struct mr_table *mrt)
416 {
417 	del_timer_sync(&mrt->ipmr_expire_timer);
418 	mroute_clean_tables(mrt, true);
419 	rhltable_destroy(&mrt->mfc_hash);
420 	kfree(mrt);
421 }
422 
423 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
424 
425 static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
426 {
427 	struct net *net = dev_net(dev);
428 
429 	dev_close(dev);
430 
431 	dev = __dev_get_by_name(net, "tunl0");
432 	if (dev) {
433 		const struct net_device_ops *ops = dev->netdev_ops;
434 		struct ifreq ifr;
435 		struct ip_tunnel_parm p;
436 
437 		memset(&p, 0, sizeof(p));
438 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
439 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
440 		p.iph.version = 4;
441 		p.iph.ihl = 5;
442 		p.iph.protocol = IPPROTO_IPIP;
443 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
444 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
445 
446 		if (ops->ndo_do_ioctl) {
447 			mm_segment_t oldfs = get_fs();
448 
449 			set_fs(KERNEL_DS);
450 			ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
451 			set_fs(oldfs);
452 		}
453 	}
454 }
455 
456 /* Initialize ipmr pimreg/tunnel in_device */
457 static bool ipmr_init_vif_indev(const struct net_device *dev)
458 {
459 	struct in_device *in_dev;
460 
461 	ASSERT_RTNL();
462 
463 	in_dev = __in_dev_get_rtnl(dev);
464 	if (!in_dev)
465 		return false;
466 	ipv4_devconf_setall(in_dev);
467 	neigh_parms_data_state_setall(in_dev->arp_parms);
468 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
469 
470 	return true;
471 }
472 
473 static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
474 {
475 	struct net_device  *dev;
476 
477 	dev = __dev_get_by_name(net, "tunl0");
478 
479 	if (dev) {
480 		const struct net_device_ops *ops = dev->netdev_ops;
481 		int err;
482 		struct ifreq ifr;
483 		struct ip_tunnel_parm p;
484 
485 		memset(&p, 0, sizeof(p));
486 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
487 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
488 		p.iph.version = 4;
489 		p.iph.ihl = 5;
490 		p.iph.protocol = IPPROTO_IPIP;
491 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
492 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
493 
494 		if (ops->ndo_do_ioctl) {
495 			mm_segment_t oldfs = get_fs();
496 
497 			set_fs(KERNEL_DS);
498 			err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
499 			set_fs(oldfs);
500 		} else {
501 			err = -EOPNOTSUPP;
502 		}
503 		dev = NULL;
504 
505 		if (err == 0 &&
506 		    (dev = __dev_get_by_name(net, p.name)) != NULL) {
507 			dev->flags |= IFF_MULTICAST;
508 			if (!ipmr_init_vif_indev(dev))
509 				goto failure;
510 			if (dev_open(dev, NULL))
511 				goto failure;
512 			dev_hold(dev);
513 		}
514 	}
515 	return dev;
516 
517 failure:
518 	unregister_netdevice(dev);
519 	return NULL;
520 }
521 
522 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
523 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
524 {
525 	struct net *net = dev_net(dev);
526 	struct mr_table *mrt;
527 	struct flowi4 fl4 = {
528 		.flowi4_oif	= dev->ifindex,
529 		.flowi4_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
530 		.flowi4_mark	= skb->mark,
531 	};
532 	int err;
533 
534 	err = ipmr_fib_lookup(net, &fl4, &mrt);
535 	if (err < 0) {
536 		kfree_skb(skb);
537 		return err;
538 	}
539 
540 	read_lock(&mrt_lock);
541 	dev->stats.tx_bytes += skb->len;
542 	dev->stats.tx_packets++;
543 	ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
544 	read_unlock(&mrt_lock);
545 	kfree_skb(skb);
546 	return NETDEV_TX_OK;
547 }
548 
549 static int reg_vif_get_iflink(const struct net_device *dev)
550 {
551 	return 0;
552 }
553 
554 static const struct net_device_ops reg_vif_netdev_ops = {
555 	.ndo_start_xmit	= reg_vif_xmit,
556 	.ndo_get_iflink = reg_vif_get_iflink,
557 };
558 
559 static void reg_vif_setup(struct net_device *dev)
560 {
561 	dev->type		= ARPHRD_PIMREG;
562 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
563 	dev->flags		= IFF_NOARP;
564 	dev->netdev_ops		= &reg_vif_netdev_ops;
565 	dev->needs_free_netdev	= true;
566 	dev->features		|= NETIF_F_NETNS_LOCAL;
567 }
568 
569 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
570 {
571 	struct net_device *dev;
572 	char name[IFNAMSIZ];
573 
574 	if (mrt->id == RT_TABLE_DEFAULT)
575 		sprintf(name, "pimreg");
576 	else
577 		sprintf(name, "pimreg%u", mrt->id);
578 
579 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
580 
581 	if (!dev)
582 		return NULL;
583 
584 	dev_net_set(dev, net);
585 
586 	if (register_netdevice(dev)) {
587 		free_netdev(dev);
588 		return NULL;
589 	}
590 
591 	if (!ipmr_init_vif_indev(dev))
592 		goto failure;
593 	if (dev_open(dev, NULL))
594 		goto failure;
595 
596 	dev_hold(dev);
597 
598 	return dev;
599 
600 failure:
601 	unregister_netdevice(dev);
602 	return NULL;
603 }
604 
605 /* called with rcu_read_lock() */
606 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
607 		     unsigned int pimlen)
608 {
609 	struct net_device *reg_dev = NULL;
610 	struct iphdr *encap;
611 
612 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
613 	/* Check that:
614 	 * a. packet is really sent to a multicast group
615 	 * b. packet is not a NULL-REGISTER
616 	 * c. packet is not truncated
617 	 */
618 	if (!ipv4_is_multicast(encap->daddr) ||
619 	    encap->tot_len == 0 ||
620 	    ntohs(encap->tot_len) + pimlen > skb->len)
621 		return 1;
622 
623 	read_lock(&mrt_lock);
624 	if (mrt->mroute_reg_vif_num >= 0)
625 		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
626 	read_unlock(&mrt_lock);
627 
628 	if (!reg_dev)
629 		return 1;
630 
631 	skb->mac_header = skb->network_header;
632 	skb_pull(skb, (u8 *)encap - skb->data);
633 	skb_reset_network_header(skb);
634 	skb->protocol = htons(ETH_P_IP);
635 	skb->ip_summed = CHECKSUM_NONE;
636 
637 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
638 
639 	netif_rx(skb);
640 
641 	return NET_RX_SUCCESS;
642 }
643 #else
644 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
645 {
646 	return NULL;
647 }
648 #endif
649 
650 static int call_ipmr_vif_entry_notifiers(struct net *net,
651 					 enum fib_event_type event_type,
652 					 struct vif_device *vif,
653 					 vifi_t vif_index, u32 tb_id)
654 {
655 	return mr_call_vif_notifiers(net, RTNL_FAMILY_IPMR, event_type,
656 				     vif, vif_index, tb_id,
657 				     &net->ipv4.ipmr_seq);
658 }
659 
660 static int call_ipmr_mfc_entry_notifiers(struct net *net,
661 					 enum fib_event_type event_type,
662 					 struct mfc_cache *mfc, u32 tb_id)
663 {
664 	return mr_call_mfc_notifiers(net, RTNL_FAMILY_IPMR, event_type,
665 				     &mfc->_c, tb_id, &net->ipv4.ipmr_seq);
666 }
667 
668 /**
669  *	vif_delete - Delete a VIF entry
670  *	@notify: Set to 1, if the caller is a notifier_call
671  */
672 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
673 		      struct list_head *head)
674 {
675 	struct net *net = read_pnet(&mrt->net);
676 	struct vif_device *v;
677 	struct net_device *dev;
678 	struct in_device *in_dev;
679 
680 	if (vifi < 0 || vifi >= mrt->maxvif)
681 		return -EADDRNOTAVAIL;
682 
683 	v = &mrt->vif_table[vifi];
684 
685 	if (VIF_EXISTS(mrt, vifi))
686 		call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_DEL, v, vifi,
687 					      mrt->id);
688 
689 	write_lock_bh(&mrt_lock);
690 	dev = v->dev;
691 	v->dev = NULL;
692 
693 	if (!dev) {
694 		write_unlock_bh(&mrt_lock);
695 		return -EADDRNOTAVAIL;
696 	}
697 
698 	if (vifi == mrt->mroute_reg_vif_num)
699 		mrt->mroute_reg_vif_num = -1;
700 
701 	if (vifi + 1 == mrt->maxvif) {
702 		int tmp;
703 
704 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
705 			if (VIF_EXISTS(mrt, tmp))
706 				break;
707 		}
708 		mrt->maxvif = tmp+1;
709 	}
710 
711 	write_unlock_bh(&mrt_lock);
712 
713 	dev_set_allmulti(dev, -1);
714 
715 	in_dev = __in_dev_get_rtnl(dev);
716 	if (in_dev) {
717 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
718 		inet_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
719 					    NETCONFA_MC_FORWARDING,
720 					    dev->ifindex, &in_dev->cnf);
721 		ip_rt_multicast_event(in_dev);
722 	}
723 
724 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
725 		unregister_netdevice_queue(dev, head);
726 
727 	dev_put(dev);
728 	return 0;
729 }
730 
731 static void ipmr_cache_free_rcu(struct rcu_head *head)
732 {
733 	struct mr_mfc *c = container_of(head, struct mr_mfc, rcu);
734 
735 	kmem_cache_free(mrt_cachep, (struct mfc_cache *)c);
736 }
737 
738 static void ipmr_cache_free(struct mfc_cache *c)
739 {
740 	call_rcu(&c->_c.rcu, ipmr_cache_free_rcu);
741 }
742 
743 /* Destroy an unresolved cache entry, killing queued skbs
744  * and reporting error to netlink readers.
745  */
746 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
747 {
748 	struct net *net = read_pnet(&mrt->net);
749 	struct sk_buff *skb;
750 	struct nlmsgerr *e;
751 
752 	atomic_dec(&mrt->cache_resolve_queue_len);
753 
754 	while ((skb = skb_dequeue(&c->_c.mfc_un.unres.unresolved))) {
755 		if (ip_hdr(skb)->version == 0) {
756 			struct nlmsghdr *nlh = skb_pull(skb,
757 							sizeof(struct iphdr));
758 			nlh->nlmsg_type = NLMSG_ERROR;
759 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
760 			skb_trim(skb, nlh->nlmsg_len);
761 			e = nlmsg_data(nlh);
762 			e->error = -ETIMEDOUT;
763 			memset(&e->msg, 0, sizeof(e->msg));
764 
765 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
766 		} else {
767 			kfree_skb(skb);
768 		}
769 	}
770 
771 	ipmr_cache_free(c);
772 }
773 
774 /* Timer process for the unresolved queue. */
775 static void ipmr_expire_process(struct timer_list *t)
776 {
777 	struct mr_table *mrt = from_timer(mrt, t, ipmr_expire_timer);
778 	struct mr_mfc *c, *next;
779 	unsigned long expires;
780 	unsigned long now;
781 
782 	if (!spin_trylock(&mfc_unres_lock)) {
783 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
784 		return;
785 	}
786 
787 	if (list_empty(&mrt->mfc_unres_queue))
788 		goto out;
789 
790 	now = jiffies;
791 	expires = 10*HZ;
792 
793 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
794 		if (time_after(c->mfc_un.unres.expires, now)) {
795 			unsigned long interval = c->mfc_un.unres.expires - now;
796 			if (interval < expires)
797 				expires = interval;
798 			continue;
799 		}
800 
801 		list_del(&c->list);
802 		mroute_netlink_event(mrt, (struct mfc_cache *)c, RTM_DELROUTE);
803 		ipmr_destroy_unres(mrt, (struct mfc_cache *)c);
804 	}
805 
806 	if (!list_empty(&mrt->mfc_unres_queue))
807 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
808 
809 out:
810 	spin_unlock(&mfc_unres_lock);
811 }
812 
813 /* Fill oifs list. It is called under write locked mrt_lock. */
814 static void ipmr_update_thresholds(struct mr_table *mrt, struct mr_mfc *cache,
815 				   unsigned char *ttls)
816 {
817 	int vifi;
818 
819 	cache->mfc_un.res.minvif = MAXVIFS;
820 	cache->mfc_un.res.maxvif = 0;
821 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
822 
823 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
824 		if (VIF_EXISTS(mrt, vifi) &&
825 		    ttls[vifi] && ttls[vifi] < 255) {
826 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
827 			if (cache->mfc_un.res.minvif > vifi)
828 				cache->mfc_un.res.minvif = vifi;
829 			if (cache->mfc_un.res.maxvif <= vifi)
830 				cache->mfc_un.res.maxvif = vifi + 1;
831 		}
832 	}
833 	cache->mfc_un.res.lastuse = jiffies;
834 }
835 
836 static int vif_add(struct net *net, struct mr_table *mrt,
837 		   struct vifctl *vifc, int mrtsock)
838 {
839 	struct netdev_phys_item_id ppid = { };
840 	int vifi = vifc->vifc_vifi;
841 	struct vif_device *v = &mrt->vif_table[vifi];
842 	struct net_device *dev;
843 	struct in_device *in_dev;
844 	int err;
845 
846 	/* Is vif busy ? */
847 	if (VIF_EXISTS(mrt, vifi))
848 		return -EADDRINUSE;
849 
850 	switch (vifc->vifc_flags) {
851 	case VIFF_REGISTER:
852 		if (!ipmr_pimsm_enabled())
853 			return -EINVAL;
854 		/* Special Purpose VIF in PIM
855 		 * All the packets will be sent to the daemon
856 		 */
857 		if (mrt->mroute_reg_vif_num >= 0)
858 			return -EADDRINUSE;
859 		dev = ipmr_reg_vif(net, mrt);
860 		if (!dev)
861 			return -ENOBUFS;
862 		err = dev_set_allmulti(dev, 1);
863 		if (err) {
864 			unregister_netdevice(dev);
865 			dev_put(dev);
866 			return err;
867 		}
868 		break;
869 	case VIFF_TUNNEL:
870 		dev = ipmr_new_tunnel(net, vifc);
871 		if (!dev)
872 			return -ENOBUFS;
873 		err = dev_set_allmulti(dev, 1);
874 		if (err) {
875 			ipmr_del_tunnel(dev, vifc);
876 			dev_put(dev);
877 			return err;
878 		}
879 		break;
880 	case VIFF_USE_IFINDEX:
881 	case 0:
882 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
883 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
884 			if (dev && !__in_dev_get_rtnl(dev)) {
885 				dev_put(dev);
886 				return -EADDRNOTAVAIL;
887 			}
888 		} else {
889 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
890 		}
891 		if (!dev)
892 			return -EADDRNOTAVAIL;
893 		err = dev_set_allmulti(dev, 1);
894 		if (err) {
895 			dev_put(dev);
896 			return err;
897 		}
898 		break;
899 	default:
900 		return -EINVAL;
901 	}
902 
903 	in_dev = __in_dev_get_rtnl(dev);
904 	if (!in_dev) {
905 		dev_put(dev);
906 		return -EADDRNOTAVAIL;
907 	}
908 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
909 	inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING,
910 				    dev->ifindex, &in_dev->cnf);
911 	ip_rt_multicast_event(in_dev);
912 
913 	/* Fill in the VIF structures */
914 	vif_device_init(v, dev, vifc->vifc_rate_limit,
915 			vifc->vifc_threshold,
916 			vifc->vifc_flags | (!mrtsock ? VIFF_STATIC : 0),
917 			(VIFF_TUNNEL | VIFF_REGISTER));
918 
919 	err = dev_get_port_parent_id(dev, &ppid, true);
920 	if (err == 0) {
921 		memcpy(v->dev_parent_id.id, ppid.id, ppid.id_len);
922 		v->dev_parent_id.id_len = ppid.id_len;
923 	} else {
924 		v->dev_parent_id.id_len = 0;
925 	}
926 
927 	v->local = vifc->vifc_lcl_addr.s_addr;
928 	v->remote = vifc->vifc_rmt_addr.s_addr;
929 
930 	/* And finish update writing critical data */
931 	write_lock_bh(&mrt_lock);
932 	v->dev = dev;
933 	if (v->flags & VIFF_REGISTER)
934 		mrt->mroute_reg_vif_num = vifi;
935 	if (vifi+1 > mrt->maxvif)
936 		mrt->maxvif = vifi+1;
937 	write_unlock_bh(&mrt_lock);
938 	call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD, v, vifi, mrt->id);
939 	return 0;
940 }
941 
942 /* called with rcu_read_lock() */
943 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
944 					 __be32 origin,
945 					 __be32 mcastgrp)
946 {
947 	struct mfc_cache_cmp_arg arg = {
948 			.mfc_mcastgrp = mcastgrp,
949 			.mfc_origin = origin
950 	};
951 
952 	return mr_mfc_find(mrt, &arg);
953 }
954 
955 /* Look for a (*,G) entry */
956 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
957 					     __be32 mcastgrp, int vifi)
958 {
959 	struct mfc_cache_cmp_arg arg = {
960 			.mfc_mcastgrp = mcastgrp,
961 			.mfc_origin = htonl(INADDR_ANY)
962 	};
963 
964 	if (mcastgrp == htonl(INADDR_ANY))
965 		return mr_mfc_find_any_parent(mrt, vifi);
966 	return mr_mfc_find_any(mrt, vifi, &arg);
967 }
968 
969 /* Look for a (S,G,iif) entry if parent != -1 */
970 static struct mfc_cache *ipmr_cache_find_parent(struct mr_table *mrt,
971 						__be32 origin, __be32 mcastgrp,
972 						int parent)
973 {
974 	struct mfc_cache_cmp_arg arg = {
975 			.mfc_mcastgrp = mcastgrp,
976 			.mfc_origin = origin,
977 	};
978 
979 	return mr_mfc_find_parent(mrt, &arg, parent);
980 }
981 
982 /* Allocate a multicast cache entry */
983 static struct mfc_cache *ipmr_cache_alloc(void)
984 {
985 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
986 
987 	if (c) {
988 		c->_c.mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
989 		c->_c.mfc_un.res.minvif = MAXVIFS;
990 		c->_c.free = ipmr_cache_free_rcu;
991 		refcount_set(&c->_c.mfc_un.res.refcount, 1);
992 	}
993 	return c;
994 }
995 
996 static struct mfc_cache *ipmr_cache_alloc_unres(void)
997 {
998 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
999 
1000 	if (c) {
1001 		skb_queue_head_init(&c->_c.mfc_un.unres.unresolved);
1002 		c->_c.mfc_un.unres.expires = jiffies + 10 * HZ;
1003 	}
1004 	return c;
1005 }
1006 
1007 /* A cache entry has gone into a resolved state from queued */
1008 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
1009 			       struct mfc_cache *uc, struct mfc_cache *c)
1010 {
1011 	struct sk_buff *skb;
1012 	struct nlmsgerr *e;
1013 
1014 	/* Play the pending entries through our router */
1015 	while ((skb = __skb_dequeue(&uc->_c.mfc_un.unres.unresolved))) {
1016 		if (ip_hdr(skb)->version == 0) {
1017 			struct nlmsghdr *nlh = skb_pull(skb,
1018 							sizeof(struct iphdr));
1019 
1020 			if (mr_fill_mroute(mrt, skb, &c->_c,
1021 					   nlmsg_data(nlh)) > 0) {
1022 				nlh->nlmsg_len = skb_tail_pointer(skb) -
1023 						 (u8 *)nlh;
1024 			} else {
1025 				nlh->nlmsg_type = NLMSG_ERROR;
1026 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
1027 				skb_trim(skb, nlh->nlmsg_len);
1028 				e = nlmsg_data(nlh);
1029 				e->error = -EMSGSIZE;
1030 				memset(&e->msg, 0, sizeof(e->msg));
1031 			}
1032 
1033 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
1034 		} else {
1035 			ip_mr_forward(net, mrt, skb->dev, skb, c, 0);
1036 		}
1037 	}
1038 }
1039 
1040 /* Bounce a cache query up to mrouted and netlink.
1041  *
1042  * Called under mrt_lock.
1043  */
1044 static int ipmr_cache_report(struct mr_table *mrt,
1045 			     struct sk_buff *pkt, vifi_t vifi, int assert)
1046 {
1047 	const int ihl = ip_hdrlen(pkt);
1048 	struct sock *mroute_sk;
1049 	struct igmphdr *igmp;
1050 	struct igmpmsg *msg;
1051 	struct sk_buff *skb;
1052 	int ret;
1053 
1054 	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE)
1055 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
1056 	else
1057 		skb = alloc_skb(128, GFP_ATOMIC);
1058 
1059 	if (!skb)
1060 		return -ENOBUFS;
1061 
1062 	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE) {
1063 		/* Ugly, but we have no choice with this interface.
1064 		 * Duplicate old header, fix ihl, length etc.
1065 		 * And all this only to mangle msg->im_msgtype and
1066 		 * to set msg->im_mbz to "mbz" :-)
1067 		 */
1068 		skb_push(skb, sizeof(struct iphdr));
1069 		skb_reset_network_header(skb);
1070 		skb_reset_transport_header(skb);
1071 		msg = (struct igmpmsg *)skb_network_header(skb);
1072 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
1073 		msg->im_msgtype = assert;
1074 		msg->im_mbz = 0;
1075 		if (assert == IGMPMSG_WRVIFWHOLE)
1076 			msg->im_vif = vifi;
1077 		else
1078 			msg->im_vif = mrt->mroute_reg_vif_num;
1079 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
1080 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
1081 					     sizeof(struct iphdr));
1082 	} else {
1083 		/* Copy the IP header */
1084 		skb_set_network_header(skb, skb->len);
1085 		skb_put(skb, ihl);
1086 		skb_copy_to_linear_data(skb, pkt->data, ihl);
1087 		/* Flag to the kernel this is a route add */
1088 		ip_hdr(skb)->protocol = 0;
1089 		msg = (struct igmpmsg *)skb_network_header(skb);
1090 		msg->im_vif = vifi;
1091 		skb_dst_set(skb, dst_clone(skb_dst(pkt)));
1092 		/* Add our header */
1093 		igmp = skb_put(skb, sizeof(struct igmphdr));
1094 		igmp->type = assert;
1095 		msg->im_msgtype = assert;
1096 		igmp->code = 0;
1097 		ip_hdr(skb)->tot_len = htons(skb->len);	/* Fix the length */
1098 		skb->transport_header = skb->network_header;
1099 	}
1100 
1101 	rcu_read_lock();
1102 	mroute_sk = rcu_dereference(mrt->mroute_sk);
1103 	if (!mroute_sk) {
1104 		rcu_read_unlock();
1105 		kfree_skb(skb);
1106 		return -EINVAL;
1107 	}
1108 
1109 	igmpmsg_netlink_event(mrt, skb);
1110 
1111 	/* Deliver to mrouted */
1112 	ret = sock_queue_rcv_skb(mroute_sk, skb);
1113 	rcu_read_unlock();
1114 	if (ret < 0) {
1115 		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1116 		kfree_skb(skb);
1117 	}
1118 
1119 	return ret;
1120 }
1121 
1122 /* Queue a packet for resolution. It gets locked cache entry! */
1123 static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
1124 				 struct sk_buff *skb, struct net_device *dev)
1125 {
1126 	const struct iphdr *iph = ip_hdr(skb);
1127 	struct mfc_cache *c;
1128 	bool found = false;
1129 	int err;
1130 
1131 	spin_lock_bh(&mfc_unres_lock);
1132 	list_for_each_entry(c, &mrt->mfc_unres_queue, _c.list) {
1133 		if (c->mfc_mcastgrp == iph->daddr &&
1134 		    c->mfc_origin == iph->saddr) {
1135 			found = true;
1136 			break;
1137 		}
1138 	}
1139 
1140 	if (!found) {
1141 		/* Create a new entry if allowable */
1142 		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
1143 		    (c = ipmr_cache_alloc_unres()) == NULL) {
1144 			spin_unlock_bh(&mfc_unres_lock);
1145 
1146 			kfree_skb(skb);
1147 			return -ENOBUFS;
1148 		}
1149 
1150 		/* Fill in the new cache entry */
1151 		c->_c.mfc_parent = -1;
1152 		c->mfc_origin	= iph->saddr;
1153 		c->mfc_mcastgrp	= iph->daddr;
1154 
1155 		/* Reflect first query at mrouted. */
1156 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1157 
1158 		if (err < 0) {
1159 			/* If the report failed throw the cache entry
1160 			   out - Brad Parker
1161 			 */
1162 			spin_unlock_bh(&mfc_unres_lock);
1163 
1164 			ipmr_cache_free(c);
1165 			kfree_skb(skb);
1166 			return err;
1167 		}
1168 
1169 		atomic_inc(&mrt->cache_resolve_queue_len);
1170 		list_add(&c->_c.list, &mrt->mfc_unres_queue);
1171 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1172 
1173 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1174 			mod_timer(&mrt->ipmr_expire_timer,
1175 				  c->_c.mfc_un.unres.expires);
1176 	}
1177 
1178 	/* See if we can append the packet */
1179 	if (c->_c.mfc_un.unres.unresolved.qlen > 3) {
1180 		kfree_skb(skb);
1181 		err = -ENOBUFS;
1182 	} else {
1183 		if (dev) {
1184 			skb->dev = dev;
1185 			skb->skb_iif = dev->ifindex;
1186 		}
1187 		skb_queue_tail(&c->_c.mfc_un.unres.unresolved, skb);
1188 		err = 0;
1189 	}
1190 
1191 	spin_unlock_bh(&mfc_unres_lock);
1192 	return err;
1193 }
1194 
1195 /* MFC cache manipulation by user space mroute daemon */
1196 
1197 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1198 {
1199 	struct net *net = read_pnet(&mrt->net);
1200 	struct mfc_cache *c;
1201 
1202 	/* The entries are added/deleted only under RTNL */
1203 	rcu_read_lock();
1204 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1205 				   mfc->mfcc_mcastgrp.s_addr, parent);
1206 	rcu_read_unlock();
1207 	if (!c)
1208 		return -ENOENT;
1209 	rhltable_remove(&mrt->mfc_hash, &c->_c.mnode, ipmr_rht_params);
1210 	list_del_rcu(&c->_c.list);
1211 	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, c, mrt->id);
1212 	mroute_netlink_event(mrt, c, RTM_DELROUTE);
1213 	mr_cache_put(&c->_c);
1214 
1215 	return 0;
1216 }
1217 
1218 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1219 			struct mfcctl *mfc, int mrtsock, int parent)
1220 {
1221 	struct mfc_cache *uc, *c;
1222 	struct mr_mfc *_uc;
1223 	bool found;
1224 	int ret;
1225 
1226 	if (mfc->mfcc_parent >= MAXVIFS)
1227 		return -ENFILE;
1228 
1229 	/* The entries are added/deleted only under RTNL */
1230 	rcu_read_lock();
1231 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1232 				   mfc->mfcc_mcastgrp.s_addr, parent);
1233 	rcu_read_unlock();
1234 	if (c) {
1235 		write_lock_bh(&mrt_lock);
1236 		c->_c.mfc_parent = mfc->mfcc_parent;
1237 		ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
1238 		if (!mrtsock)
1239 			c->_c.mfc_flags |= MFC_STATIC;
1240 		write_unlock_bh(&mrt_lock);
1241 		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, c,
1242 					      mrt->id);
1243 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1244 		return 0;
1245 	}
1246 
1247 	if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1248 	    !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1249 		return -EINVAL;
1250 
1251 	c = ipmr_cache_alloc();
1252 	if (!c)
1253 		return -ENOMEM;
1254 
1255 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1256 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1257 	c->_c.mfc_parent = mfc->mfcc_parent;
1258 	ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
1259 	if (!mrtsock)
1260 		c->_c.mfc_flags |= MFC_STATIC;
1261 
1262 	ret = rhltable_insert_key(&mrt->mfc_hash, &c->cmparg, &c->_c.mnode,
1263 				  ipmr_rht_params);
1264 	if (ret) {
1265 		pr_err("ipmr: rhtable insert error %d\n", ret);
1266 		ipmr_cache_free(c);
1267 		return ret;
1268 	}
1269 	list_add_tail_rcu(&c->_c.list, &mrt->mfc_cache_list);
1270 	/* Check to see if we resolved a queued list. If so we
1271 	 * need to send on the frames and tidy up.
1272 	 */
1273 	found = false;
1274 	spin_lock_bh(&mfc_unres_lock);
1275 	list_for_each_entry(_uc, &mrt->mfc_unres_queue, list) {
1276 		uc = (struct mfc_cache *)_uc;
1277 		if (uc->mfc_origin == c->mfc_origin &&
1278 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1279 			list_del(&_uc->list);
1280 			atomic_dec(&mrt->cache_resolve_queue_len);
1281 			found = true;
1282 			break;
1283 		}
1284 	}
1285 	if (list_empty(&mrt->mfc_unres_queue))
1286 		del_timer(&mrt->ipmr_expire_timer);
1287 	spin_unlock_bh(&mfc_unres_lock);
1288 
1289 	if (found) {
1290 		ipmr_cache_resolve(net, mrt, uc, c);
1291 		ipmr_cache_free(uc);
1292 	}
1293 	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, c, mrt->id);
1294 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1295 	return 0;
1296 }
1297 
1298 /* Close the multicast socket, and clear the vif tables etc */
1299 static void mroute_clean_tables(struct mr_table *mrt, bool all)
1300 {
1301 	struct net *net = read_pnet(&mrt->net);
1302 	struct mr_mfc *c, *tmp;
1303 	struct mfc_cache *cache;
1304 	LIST_HEAD(list);
1305 	int i;
1306 
1307 	/* Shut down all active vif entries */
1308 	for (i = 0; i < mrt->maxvif; i++) {
1309 		if (!all && (mrt->vif_table[i].flags & VIFF_STATIC))
1310 			continue;
1311 		vif_delete(mrt, i, 0, &list);
1312 	}
1313 	unregister_netdevice_many(&list);
1314 
1315 	/* Wipe the cache */
1316 	list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
1317 		if (!all && (c->mfc_flags & MFC_STATIC))
1318 			continue;
1319 		rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
1320 		list_del_rcu(&c->list);
1321 		cache = (struct mfc_cache *)c;
1322 		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
1323 					      mrt->id);
1324 		mroute_netlink_event(mrt, cache, RTM_DELROUTE);
1325 		mr_cache_put(c);
1326 	}
1327 
1328 	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1329 		spin_lock_bh(&mfc_unres_lock);
1330 		list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
1331 			list_del(&c->list);
1332 			cache = (struct mfc_cache *)c;
1333 			mroute_netlink_event(mrt, cache, RTM_DELROUTE);
1334 			ipmr_destroy_unres(mrt, cache);
1335 		}
1336 		spin_unlock_bh(&mfc_unres_lock);
1337 	}
1338 }
1339 
1340 /* called from ip_ra_control(), before an RCU grace period,
1341  * we dont need to call synchronize_rcu() here
1342  */
1343 static void mrtsock_destruct(struct sock *sk)
1344 {
1345 	struct net *net = sock_net(sk);
1346 	struct mr_table *mrt;
1347 
1348 	rtnl_lock();
1349 	ipmr_for_each_table(mrt, net) {
1350 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1351 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1352 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1353 						    NETCONFA_MC_FORWARDING,
1354 						    NETCONFA_IFINDEX_ALL,
1355 						    net->ipv4.devconf_all);
1356 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1357 			mroute_clean_tables(mrt, false);
1358 		}
1359 	}
1360 	rtnl_unlock();
1361 }
1362 
1363 /* Socket options and virtual interface manipulation. The whole
1364  * virtual interface system is a complete heap, but unfortunately
1365  * that's how BSD mrouted happens to think. Maybe one day with a proper
1366  * MOSPF/PIM router set up we can clean this up.
1367  */
1368 
1369 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
1370 			 unsigned int optlen)
1371 {
1372 	struct net *net = sock_net(sk);
1373 	int val, ret = 0, parent = 0;
1374 	struct mr_table *mrt;
1375 	struct vifctl vif;
1376 	struct mfcctl mfc;
1377 	bool do_wrvifwhole;
1378 	u32 uval;
1379 
1380 	/* There's one exception to the lock - MRT_DONE which needs to unlock */
1381 	rtnl_lock();
1382 	if (sk->sk_type != SOCK_RAW ||
1383 	    inet_sk(sk)->inet_num != IPPROTO_IGMP) {
1384 		ret = -EOPNOTSUPP;
1385 		goto out_unlock;
1386 	}
1387 
1388 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1389 	if (!mrt) {
1390 		ret = -ENOENT;
1391 		goto out_unlock;
1392 	}
1393 	if (optname != MRT_INIT) {
1394 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1395 		    !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
1396 			ret = -EACCES;
1397 			goto out_unlock;
1398 		}
1399 	}
1400 
1401 	switch (optname) {
1402 	case MRT_INIT:
1403 		if (optlen != sizeof(int)) {
1404 			ret = -EINVAL;
1405 			break;
1406 		}
1407 		if (rtnl_dereference(mrt->mroute_sk)) {
1408 			ret = -EADDRINUSE;
1409 			break;
1410 		}
1411 
1412 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1413 		if (ret == 0) {
1414 			rcu_assign_pointer(mrt->mroute_sk, sk);
1415 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1416 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1417 						    NETCONFA_MC_FORWARDING,
1418 						    NETCONFA_IFINDEX_ALL,
1419 						    net->ipv4.devconf_all);
1420 		}
1421 		break;
1422 	case MRT_DONE:
1423 		if (sk != rcu_access_pointer(mrt->mroute_sk)) {
1424 			ret = -EACCES;
1425 		} else {
1426 			/* We need to unlock here because mrtsock_destruct takes
1427 			 * care of rtnl itself and we can't change that due to
1428 			 * the IP_ROUTER_ALERT setsockopt which runs without it.
1429 			 */
1430 			rtnl_unlock();
1431 			ret = ip_ra_control(sk, 0, NULL);
1432 			goto out;
1433 		}
1434 		break;
1435 	case MRT_ADD_VIF:
1436 	case MRT_DEL_VIF:
1437 		if (optlen != sizeof(vif)) {
1438 			ret = -EINVAL;
1439 			break;
1440 		}
1441 		if (copy_from_user(&vif, optval, sizeof(vif))) {
1442 			ret = -EFAULT;
1443 			break;
1444 		}
1445 		if (vif.vifc_vifi >= MAXVIFS) {
1446 			ret = -ENFILE;
1447 			break;
1448 		}
1449 		if (optname == MRT_ADD_VIF) {
1450 			ret = vif_add(net, mrt, &vif,
1451 				      sk == rtnl_dereference(mrt->mroute_sk));
1452 		} else {
1453 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1454 		}
1455 		break;
1456 	/* Manipulate the forwarding caches. These live
1457 	 * in a sort of kernel/user symbiosis.
1458 	 */
1459 	case MRT_ADD_MFC:
1460 	case MRT_DEL_MFC:
1461 		parent = -1;
1462 		/* fall through */
1463 	case MRT_ADD_MFC_PROXY:
1464 	case MRT_DEL_MFC_PROXY:
1465 		if (optlen != sizeof(mfc)) {
1466 			ret = -EINVAL;
1467 			break;
1468 		}
1469 		if (copy_from_user(&mfc, optval, sizeof(mfc))) {
1470 			ret = -EFAULT;
1471 			break;
1472 		}
1473 		if (parent == 0)
1474 			parent = mfc.mfcc_parent;
1475 		if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1476 			ret = ipmr_mfc_delete(mrt, &mfc, parent);
1477 		else
1478 			ret = ipmr_mfc_add(net, mrt, &mfc,
1479 					   sk == rtnl_dereference(mrt->mroute_sk),
1480 					   parent);
1481 		break;
1482 	/* Control PIM assert. */
1483 	case MRT_ASSERT:
1484 		if (optlen != sizeof(val)) {
1485 			ret = -EINVAL;
1486 			break;
1487 		}
1488 		if (get_user(val, (int __user *)optval)) {
1489 			ret = -EFAULT;
1490 			break;
1491 		}
1492 		mrt->mroute_do_assert = val;
1493 		break;
1494 	case MRT_PIM:
1495 		if (!ipmr_pimsm_enabled()) {
1496 			ret = -ENOPROTOOPT;
1497 			break;
1498 		}
1499 		if (optlen != sizeof(val)) {
1500 			ret = -EINVAL;
1501 			break;
1502 		}
1503 		if (get_user(val, (int __user *)optval)) {
1504 			ret = -EFAULT;
1505 			break;
1506 		}
1507 
1508 		do_wrvifwhole = (val == IGMPMSG_WRVIFWHOLE);
1509 		val = !!val;
1510 		if (val != mrt->mroute_do_pim) {
1511 			mrt->mroute_do_pim = val;
1512 			mrt->mroute_do_assert = val;
1513 			mrt->mroute_do_wrvifwhole = do_wrvifwhole;
1514 		}
1515 		break;
1516 	case MRT_TABLE:
1517 		if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) {
1518 			ret = -ENOPROTOOPT;
1519 			break;
1520 		}
1521 		if (optlen != sizeof(uval)) {
1522 			ret = -EINVAL;
1523 			break;
1524 		}
1525 		if (get_user(uval, (u32 __user *)optval)) {
1526 			ret = -EFAULT;
1527 			break;
1528 		}
1529 
1530 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1531 			ret = -EBUSY;
1532 		} else {
1533 			mrt = ipmr_new_table(net, uval);
1534 			if (IS_ERR(mrt))
1535 				ret = PTR_ERR(mrt);
1536 			else
1537 				raw_sk(sk)->ipmr_table = uval;
1538 		}
1539 		break;
1540 	/* Spurious command, or MRT_VERSION which you cannot set. */
1541 	default:
1542 		ret = -ENOPROTOOPT;
1543 	}
1544 out_unlock:
1545 	rtnl_unlock();
1546 out:
1547 	return ret;
1548 }
1549 
1550 /* Getsock opt support for the multicast routing system. */
1551 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1552 {
1553 	int olr;
1554 	int val;
1555 	struct net *net = sock_net(sk);
1556 	struct mr_table *mrt;
1557 
1558 	if (sk->sk_type != SOCK_RAW ||
1559 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1560 		return -EOPNOTSUPP;
1561 
1562 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1563 	if (!mrt)
1564 		return -ENOENT;
1565 
1566 	switch (optname) {
1567 	case MRT_VERSION:
1568 		val = 0x0305;
1569 		break;
1570 	case MRT_PIM:
1571 		if (!ipmr_pimsm_enabled())
1572 			return -ENOPROTOOPT;
1573 		val = mrt->mroute_do_pim;
1574 		break;
1575 	case MRT_ASSERT:
1576 		val = mrt->mroute_do_assert;
1577 		break;
1578 	default:
1579 		return -ENOPROTOOPT;
1580 	}
1581 
1582 	if (get_user(olr, optlen))
1583 		return -EFAULT;
1584 	olr = min_t(unsigned int, olr, sizeof(int));
1585 	if (olr < 0)
1586 		return -EINVAL;
1587 	if (put_user(olr, optlen))
1588 		return -EFAULT;
1589 	if (copy_to_user(optval, &val, olr))
1590 		return -EFAULT;
1591 	return 0;
1592 }
1593 
1594 /* The IP multicast ioctl support routines. */
1595 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1596 {
1597 	struct sioc_sg_req sr;
1598 	struct sioc_vif_req vr;
1599 	struct vif_device *vif;
1600 	struct mfc_cache *c;
1601 	struct net *net = sock_net(sk);
1602 	struct mr_table *mrt;
1603 
1604 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1605 	if (!mrt)
1606 		return -ENOENT;
1607 
1608 	switch (cmd) {
1609 	case SIOCGETVIFCNT:
1610 		if (copy_from_user(&vr, arg, sizeof(vr)))
1611 			return -EFAULT;
1612 		if (vr.vifi >= mrt->maxvif)
1613 			return -EINVAL;
1614 		vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif);
1615 		read_lock(&mrt_lock);
1616 		vif = &mrt->vif_table[vr.vifi];
1617 		if (VIF_EXISTS(mrt, vr.vifi)) {
1618 			vr.icount = vif->pkt_in;
1619 			vr.ocount = vif->pkt_out;
1620 			vr.ibytes = vif->bytes_in;
1621 			vr.obytes = vif->bytes_out;
1622 			read_unlock(&mrt_lock);
1623 
1624 			if (copy_to_user(arg, &vr, sizeof(vr)))
1625 				return -EFAULT;
1626 			return 0;
1627 		}
1628 		read_unlock(&mrt_lock);
1629 		return -EADDRNOTAVAIL;
1630 	case SIOCGETSGCNT:
1631 		if (copy_from_user(&sr, arg, sizeof(sr)))
1632 			return -EFAULT;
1633 
1634 		rcu_read_lock();
1635 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1636 		if (c) {
1637 			sr.pktcnt = c->_c.mfc_un.res.pkt;
1638 			sr.bytecnt = c->_c.mfc_un.res.bytes;
1639 			sr.wrong_if = c->_c.mfc_un.res.wrong_if;
1640 			rcu_read_unlock();
1641 
1642 			if (copy_to_user(arg, &sr, sizeof(sr)))
1643 				return -EFAULT;
1644 			return 0;
1645 		}
1646 		rcu_read_unlock();
1647 		return -EADDRNOTAVAIL;
1648 	default:
1649 		return -ENOIOCTLCMD;
1650 	}
1651 }
1652 
1653 #ifdef CONFIG_COMPAT
1654 struct compat_sioc_sg_req {
1655 	struct in_addr src;
1656 	struct in_addr grp;
1657 	compat_ulong_t pktcnt;
1658 	compat_ulong_t bytecnt;
1659 	compat_ulong_t wrong_if;
1660 };
1661 
1662 struct compat_sioc_vif_req {
1663 	vifi_t	vifi;		/* Which iface */
1664 	compat_ulong_t icount;
1665 	compat_ulong_t ocount;
1666 	compat_ulong_t ibytes;
1667 	compat_ulong_t obytes;
1668 };
1669 
1670 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1671 {
1672 	struct compat_sioc_sg_req sr;
1673 	struct compat_sioc_vif_req vr;
1674 	struct vif_device *vif;
1675 	struct mfc_cache *c;
1676 	struct net *net = sock_net(sk);
1677 	struct mr_table *mrt;
1678 
1679 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1680 	if (!mrt)
1681 		return -ENOENT;
1682 
1683 	switch (cmd) {
1684 	case SIOCGETVIFCNT:
1685 		if (copy_from_user(&vr, arg, sizeof(vr)))
1686 			return -EFAULT;
1687 		if (vr.vifi >= mrt->maxvif)
1688 			return -EINVAL;
1689 		vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif);
1690 		read_lock(&mrt_lock);
1691 		vif = &mrt->vif_table[vr.vifi];
1692 		if (VIF_EXISTS(mrt, vr.vifi)) {
1693 			vr.icount = vif->pkt_in;
1694 			vr.ocount = vif->pkt_out;
1695 			vr.ibytes = vif->bytes_in;
1696 			vr.obytes = vif->bytes_out;
1697 			read_unlock(&mrt_lock);
1698 
1699 			if (copy_to_user(arg, &vr, sizeof(vr)))
1700 				return -EFAULT;
1701 			return 0;
1702 		}
1703 		read_unlock(&mrt_lock);
1704 		return -EADDRNOTAVAIL;
1705 	case SIOCGETSGCNT:
1706 		if (copy_from_user(&sr, arg, sizeof(sr)))
1707 			return -EFAULT;
1708 
1709 		rcu_read_lock();
1710 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1711 		if (c) {
1712 			sr.pktcnt = c->_c.mfc_un.res.pkt;
1713 			sr.bytecnt = c->_c.mfc_un.res.bytes;
1714 			sr.wrong_if = c->_c.mfc_un.res.wrong_if;
1715 			rcu_read_unlock();
1716 
1717 			if (copy_to_user(arg, &sr, sizeof(sr)))
1718 				return -EFAULT;
1719 			return 0;
1720 		}
1721 		rcu_read_unlock();
1722 		return -EADDRNOTAVAIL;
1723 	default:
1724 		return -ENOIOCTLCMD;
1725 	}
1726 }
1727 #endif
1728 
1729 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1730 {
1731 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1732 	struct net *net = dev_net(dev);
1733 	struct mr_table *mrt;
1734 	struct vif_device *v;
1735 	int ct;
1736 
1737 	if (event != NETDEV_UNREGISTER)
1738 		return NOTIFY_DONE;
1739 
1740 	ipmr_for_each_table(mrt, net) {
1741 		v = &mrt->vif_table[0];
1742 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1743 			if (v->dev == dev)
1744 				vif_delete(mrt, ct, 1, NULL);
1745 		}
1746 	}
1747 	return NOTIFY_DONE;
1748 }
1749 
1750 static struct notifier_block ip_mr_notifier = {
1751 	.notifier_call = ipmr_device_event,
1752 };
1753 
1754 /* Encapsulate a packet by attaching a valid IPIP header to it.
1755  * This avoids tunnel drivers and other mess and gives us the speed so
1756  * important for multicast video.
1757  */
1758 static void ip_encap(struct net *net, struct sk_buff *skb,
1759 		     __be32 saddr, __be32 daddr)
1760 {
1761 	struct iphdr *iph;
1762 	const struct iphdr *old_iph = ip_hdr(skb);
1763 
1764 	skb_push(skb, sizeof(struct iphdr));
1765 	skb->transport_header = skb->network_header;
1766 	skb_reset_network_header(skb);
1767 	iph = ip_hdr(skb);
1768 
1769 	iph->version	=	4;
1770 	iph->tos	=	old_iph->tos;
1771 	iph->ttl	=	old_iph->ttl;
1772 	iph->frag_off	=	0;
1773 	iph->daddr	=	daddr;
1774 	iph->saddr	=	saddr;
1775 	iph->protocol	=	IPPROTO_IPIP;
1776 	iph->ihl	=	5;
1777 	iph->tot_len	=	htons(skb->len);
1778 	ip_select_ident(net, skb, NULL);
1779 	ip_send_check(iph);
1780 
1781 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1782 	nf_reset(skb);
1783 }
1784 
1785 static inline int ipmr_forward_finish(struct net *net, struct sock *sk,
1786 				      struct sk_buff *skb)
1787 {
1788 	struct ip_options *opt = &(IPCB(skb)->opt);
1789 
1790 	IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
1791 	IP_ADD_STATS(net, IPSTATS_MIB_OUTOCTETS, skb->len);
1792 
1793 	if (unlikely(opt->optlen))
1794 		ip_forward_options(skb);
1795 
1796 	return dst_output(net, sk, skb);
1797 }
1798 
1799 #ifdef CONFIG_NET_SWITCHDEV
1800 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1801 				   int in_vifi, int out_vifi)
1802 {
1803 	struct vif_device *out_vif = &mrt->vif_table[out_vifi];
1804 	struct vif_device *in_vif = &mrt->vif_table[in_vifi];
1805 
1806 	if (!skb->offload_l3_fwd_mark)
1807 		return false;
1808 	if (!out_vif->dev_parent_id.id_len || !in_vif->dev_parent_id.id_len)
1809 		return false;
1810 	return netdev_phys_item_id_same(&out_vif->dev_parent_id,
1811 					&in_vif->dev_parent_id);
1812 }
1813 #else
1814 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1815 				   int in_vifi, int out_vifi)
1816 {
1817 	return false;
1818 }
1819 #endif
1820 
1821 /* Processing handlers for ipmr_forward */
1822 
1823 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1824 			    int in_vifi, struct sk_buff *skb, int vifi)
1825 {
1826 	const struct iphdr *iph = ip_hdr(skb);
1827 	struct vif_device *vif = &mrt->vif_table[vifi];
1828 	struct net_device *dev;
1829 	struct rtable *rt;
1830 	struct flowi4 fl4;
1831 	int    encap = 0;
1832 
1833 	if (!vif->dev)
1834 		goto out_free;
1835 
1836 	if (vif->flags & VIFF_REGISTER) {
1837 		vif->pkt_out++;
1838 		vif->bytes_out += skb->len;
1839 		vif->dev->stats.tx_bytes += skb->len;
1840 		vif->dev->stats.tx_packets++;
1841 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1842 		goto out_free;
1843 	}
1844 
1845 	if (ipmr_forward_offloaded(skb, mrt, in_vifi, vifi))
1846 		goto out_free;
1847 
1848 	if (vif->flags & VIFF_TUNNEL) {
1849 		rt = ip_route_output_ports(net, &fl4, NULL,
1850 					   vif->remote, vif->local,
1851 					   0, 0,
1852 					   IPPROTO_IPIP,
1853 					   RT_TOS(iph->tos), vif->link);
1854 		if (IS_ERR(rt))
1855 			goto out_free;
1856 		encap = sizeof(struct iphdr);
1857 	} else {
1858 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1859 					   0, 0,
1860 					   IPPROTO_IPIP,
1861 					   RT_TOS(iph->tos), vif->link);
1862 		if (IS_ERR(rt))
1863 			goto out_free;
1864 	}
1865 
1866 	dev = rt->dst.dev;
1867 
1868 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1869 		/* Do not fragment multicasts. Alas, IPv4 does not
1870 		 * allow to send ICMP, so that packets will disappear
1871 		 * to blackhole.
1872 		 */
1873 		IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
1874 		ip_rt_put(rt);
1875 		goto out_free;
1876 	}
1877 
1878 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1879 
1880 	if (skb_cow(skb, encap)) {
1881 		ip_rt_put(rt);
1882 		goto out_free;
1883 	}
1884 
1885 	vif->pkt_out++;
1886 	vif->bytes_out += skb->len;
1887 
1888 	skb_dst_drop(skb);
1889 	skb_dst_set(skb, &rt->dst);
1890 	ip_decrease_ttl(ip_hdr(skb));
1891 
1892 	/* FIXME: forward and output firewalls used to be called here.
1893 	 * What do we do with netfilter? -- RR
1894 	 */
1895 	if (vif->flags & VIFF_TUNNEL) {
1896 		ip_encap(net, skb, vif->local, vif->remote);
1897 		/* FIXME: extra output firewall step used to be here. --RR */
1898 		vif->dev->stats.tx_packets++;
1899 		vif->dev->stats.tx_bytes += skb->len;
1900 	}
1901 
1902 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1903 
1904 	/* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1905 	 * not only before forwarding, but after forwarding on all output
1906 	 * interfaces. It is clear, if mrouter runs a multicasting
1907 	 * program, it should receive packets not depending to what interface
1908 	 * program is joined.
1909 	 * If we will not make it, the program will have to join on all
1910 	 * interfaces. On the other hand, multihoming host (or router, but
1911 	 * not mrouter) cannot join to more than one interface - it will
1912 	 * result in receiving multiple packets.
1913 	 */
1914 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
1915 		net, NULL, skb, skb->dev, dev,
1916 		ipmr_forward_finish);
1917 	return;
1918 
1919 out_free:
1920 	kfree_skb(skb);
1921 }
1922 
1923 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1924 {
1925 	int ct;
1926 
1927 	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1928 		if (mrt->vif_table[ct].dev == dev)
1929 			break;
1930 	}
1931 	return ct;
1932 }
1933 
1934 /* "local" means that we should preserve one skb (for local delivery) */
1935 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
1936 			  struct net_device *dev, struct sk_buff *skb,
1937 			  struct mfc_cache *c, int local)
1938 {
1939 	int true_vifi = ipmr_find_vif(mrt, dev);
1940 	int psend = -1;
1941 	int vif, ct;
1942 
1943 	vif = c->_c.mfc_parent;
1944 	c->_c.mfc_un.res.pkt++;
1945 	c->_c.mfc_un.res.bytes += skb->len;
1946 	c->_c.mfc_un.res.lastuse = jiffies;
1947 
1948 	if (c->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
1949 		struct mfc_cache *cache_proxy;
1950 
1951 		/* For an (*,G) entry, we only check that the incomming
1952 		 * interface is part of the static tree.
1953 		 */
1954 		cache_proxy = mr_mfc_find_any_parent(mrt, vif);
1955 		if (cache_proxy &&
1956 		    cache_proxy->_c.mfc_un.res.ttls[true_vifi] < 255)
1957 			goto forward;
1958 	}
1959 
1960 	/* Wrong interface: drop packet and (maybe) send PIM assert. */
1961 	if (mrt->vif_table[vif].dev != dev) {
1962 		if (rt_is_output_route(skb_rtable(skb))) {
1963 			/* It is our own packet, looped back.
1964 			 * Very complicated situation...
1965 			 *
1966 			 * The best workaround until routing daemons will be
1967 			 * fixed is not to redistribute packet, if it was
1968 			 * send through wrong interface. It means, that
1969 			 * multicast applications WILL NOT work for
1970 			 * (S,G), which have default multicast route pointing
1971 			 * to wrong oif. In any case, it is not a good
1972 			 * idea to use multicasting applications on router.
1973 			 */
1974 			goto dont_forward;
1975 		}
1976 
1977 		c->_c.mfc_un.res.wrong_if++;
1978 
1979 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
1980 		    /* pimsm uses asserts, when switching from RPT to SPT,
1981 		     * so that we cannot check that packet arrived on an oif.
1982 		     * It is bad, but otherwise we would need to move pretty
1983 		     * large chunk of pimd to kernel. Ough... --ANK
1984 		     */
1985 		    (mrt->mroute_do_pim ||
1986 		     c->_c.mfc_un.res.ttls[true_vifi] < 255) &&
1987 		    time_after(jiffies,
1988 			       c->_c.mfc_un.res.last_assert +
1989 			       MFC_ASSERT_THRESH)) {
1990 			c->_c.mfc_un.res.last_assert = jiffies;
1991 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1992 			if (mrt->mroute_do_wrvifwhole)
1993 				ipmr_cache_report(mrt, skb, true_vifi,
1994 						  IGMPMSG_WRVIFWHOLE);
1995 		}
1996 		goto dont_forward;
1997 	}
1998 
1999 forward:
2000 	mrt->vif_table[vif].pkt_in++;
2001 	mrt->vif_table[vif].bytes_in += skb->len;
2002 
2003 	/* Forward the frame */
2004 	if (c->mfc_origin == htonl(INADDR_ANY) &&
2005 	    c->mfc_mcastgrp == htonl(INADDR_ANY)) {
2006 		if (true_vifi >= 0 &&
2007 		    true_vifi != c->_c.mfc_parent &&
2008 		    ip_hdr(skb)->ttl >
2009 				c->_c.mfc_un.res.ttls[c->_c.mfc_parent]) {
2010 			/* It's an (*,*) entry and the packet is not coming from
2011 			 * the upstream: forward the packet to the upstream
2012 			 * only.
2013 			 */
2014 			psend = c->_c.mfc_parent;
2015 			goto last_forward;
2016 		}
2017 		goto dont_forward;
2018 	}
2019 	for (ct = c->_c.mfc_un.res.maxvif - 1;
2020 	     ct >= c->_c.mfc_un.res.minvif; ct--) {
2021 		/* For (*,G) entry, don't forward to the incoming interface */
2022 		if ((c->mfc_origin != htonl(INADDR_ANY) ||
2023 		     ct != true_vifi) &&
2024 		    ip_hdr(skb)->ttl > c->_c.mfc_un.res.ttls[ct]) {
2025 			if (psend != -1) {
2026 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2027 
2028 				if (skb2)
2029 					ipmr_queue_xmit(net, mrt, true_vifi,
2030 							skb2, psend);
2031 			}
2032 			psend = ct;
2033 		}
2034 	}
2035 last_forward:
2036 	if (psend != -1) {
2037 		if (local) {
2038 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2039 
2040 			if (skb2)
2041 				ipmr_queue_xmit(net, mrt, true_vifi, skb2,
2042 						psend);
2043 		} else {
2044 			ipmr_queue_xmit(net, mrt, true_vifi, skb, psend);
2045 			return;
2046 		}
2047 	}
2048 
2049 dont_forward:
2050 	if (!local)
2051 		kfree_skb(skb);
2052 }
2053 
2054 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
2055 {
2056 	struct rtable *rt = skb_rtable(skb);
2057 	struct iphdr *iph = ip_hdr(skb);
2058 	struct flowi4 fl4 = {
2059 		.daddr = iph->daddr,
2060 		.saddr = iph->saddr,
2061 		.flowi4_tos = RT_TOS(iph->tos),
2062 		.flowi4_oif = (rt_is_output_route(rt) ?
2063 			       skb->dev->ifindex : 0),
2064 		.flowi4_iif = (rt_is_output_route(rt) ?
2065 			       LOOPBACK_IFINDEX :
2066 			       skb->dev->ifindex),
2067 		.flowi4_mark = skb->mark,
2068 	};
2069 	struct mr_table *mrt;
2070 	int err;
2071 
2072 	err = ipmr_fib_lookup(net, &fl4, &mrt);
2073 	if (err)
2074 		return ERR_PTR(err);
2075 	return mrt;
2076 }
2077 
2078 /* Multicast packets for forwarding arrive here
2079  * Called with rcu_read_lock();
2080  */
2081 int ip_mr_input(struct sk_buff *skb)
2082 {
2083 	struct mfc_cache *cache;
2084 	struct net *net = dev_net(skb->dev);
2085 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
2086 	struct mr_table *mrt;
2087 	struct net_device *dev;
2088 
2089 	/* skb->dev passed in is the loX master dev for vrfs.
2090 	 * As there are no vifs associated with loopback devices,
2091 	 * get the proper interface that does have a vif associated with it.
2092 	 */
2093 	dev = skb->dev;
2094 	if (netif_is_l3_master(skb->dev)) {
2095 		dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
2096 		if (!dev) {
2097 			kfree_skb(skb);
2098 			return -ENODEV;
2099 		}
2100 	}
2101 
2102 	/* Packet is looped back after forward, it should not be
2103 	 * forwarded second time, but still can be delivered locally.
2104 	 */
2105 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
2106 		goto dont_forward;
2107 
2108 	mrt = ipmr_rt_fib_lookup(net, skb);
2109 	if (IS_ERR(mrt)) {
2110 		kfree_skb(skb);
2111 		return PTR_ERR(mrt);
2112 	}
2113 	if (!local) {
2114 		if (IPCB(skb)->opt.router_alert) {
2115 			if (ip_call_ra_chain(skb))
2116 				return 0;
2117 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
2118 			/* IGMPv1 (and broken IGMPv2 implementations sort of
2119 			 * Cisco IOS <= 11.2(8)) do not put router alert
2120 			 * option to IGMP packets destined to routable
2121 			 * groups. It is very bad, because it means
2122 			 * that we can forward NO IGMP messages.
2123 			 */
2124 			struct sock *mroute_sk;
2125 
2126 			mroute_sk = rcu_dereference(mrt->mroute_sk);
2127 			if (mroute_sk) {
2128 				nf_reset(skb);
2129 				raw_rcv(mroute_sk, skb);
2130 				return 0;
2131 			}
2132 		    }
2133 	}
2134 
2135 	/* already under rcu_read_lock() */
2136 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
2137 	if (!cache) {
2138 		int vif = ipmr_find_vif(mrt, dev);
2139 
2140 		if (vif >= 0)
2141 			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
2142 						    vif);
2143 	}
2144 
2145 	/* No usable cache entry */
2146 	if (!cache) {
2147 		int vif;
2148 
2149 		if (local) {
2150 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2151 			ip_local_deliver(skb);
2152 			if (!skb2)
2153 				return -ENOBUFS;
2154 			skb = skb2;
2155 		}
2156 
2157 		read_lock(&mrt_lock);
2158 		vif = ipmr_find_vif(mrt, dev);
2159 		if (vif >= 0) {
2160 			int err2 = ipmr_cache_unresolved(mrt, vif, skb, dev);
2161 			read_unlock(&mrt_lock);
2162 
2163 			return err2;
2164 		}
2165 		read_unlock(&mrt_lock);
2166 		kfree_skb(skb);
2167 		return -ENODEV;
2168 	}
2169 
2170 	read_lock(&mrt_lock);
2171 	ip_mr_forward(net, mrt, dev, skb, cache, local);
2172 	read_unlock(&mrt_lock);
2173 
2174 	if (local)
2175 		return ip_local_deliver(skb);
2176 
2177 	return 0;
2178 
2179 dont_forward:
2180 	if (local)
2181 		return ip_local_deliver(skb);
2182 	kfree_skb(skb);
2183 	return 0;
2184 }
2185 
2186 #ifdef CONFIG_IP_PIMSM_V1
2187 /* Handle IGMP messages of PIMv1 */
2188 int pim_rcv_v1(struct sk_buff *skb)
2189 {
2190 	struct igmphdr *pim;
2191 	struct net *net = dev_net(skb->dev);
2192 	struct mr_table *mrt;
2193 
2194 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2195 		goto drop;
2196 
2197 	pim = igmp_hdr(skb);
2198 
2199 	mrt = ipmr_rt_fib_lookup(net, skb);
2200 	if (IS_ERR(mrt))
2201 		goto drop;
2202 	if (!mrt->mroute_do_pim ||
2203 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2204 		goto drop;
2205 
2206 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2207 drop:
2208 		kfree_skb(skb);
2209 	}
2210 	return 0;
2211 }
2212 #endif
2213 
2214 #ifdef CONFIG_IP_PIMSM_V2
2215 static int pim_rcv(struct sk_buff *skb)
2216 {
2217 	struct pimreghdr *pim;
2218 	struct net *net = dev_net(skb->dev);
2219 	struct mr_table *mrt;
2220 
2221 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2222 		goto drop;
2223 
2224 	pim = (struct pimreghdr *)skb_transport_header(skb);
2225 	if (pim->type != ((PIM_VERSION << 4) | (PIM_TYPE_REGISTER)) ||
2226 	    (pim->flags & PIM_NULL_REGISTER) ||
2227 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2228 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2229 		goto drop;
2230 
2231 	mrt = ipmr_rt_fib_lookup(net, skb);
2232 	if (IS_ERR(mrt))
2233 		goto drop;
2234 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2235 drop:
2236 		kfree_skb(skb);
2237 	}
2238 	return 0;
2239 }
2240 #endif
2241 
2242 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2243 		   __be32 saddr, __be32 daddr,
2244 		   struct rtmsg *rtm, u32 portid)
2245 {
2246 	struct mfc_cache *cache;
2247 	struct mr_table *mrt;
2248 	int err;
2249 
2250 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2251 	if (!mrt)
2252 		return -ENOENT;
2253 
2254 	rcu_read_lock();
2255 	cache = ipmr_cache_find(mrt, saddr, daddr);
2256 	if (!cache && skb->dev) {
2257 		int vif = ipmr_find_vif(mrt, skb->dev);
2258 
2259 		if (vif >= 0)
2260 			cache = ipmr_cache_find_any(mrt, daddr, vif);
2261 	}
2262 	if (!cache) {
2263 		struct sk_buff *skb2;
2264 		struct iphdr *iph;
2265 		struct net_device *dev;
2266 		int vif = -1;
2267 
2268 		dev = skb->dev;
2269 		read_lock(&mrt_lock);
2270 		if (dev)
2271 			vif = ipmr_find_vif(mrt, dev);
2272 		if (vif < 0) {
2273 			read_unlock(&mrt_lock);
2274 			rcu_read_unlock();
2275 			return -ENODEV;
2276 		}
2277 		skb2 = skb_clone(skb, GFP_ATOMIC);
2278 		if (!skb2) {
2279 			read_unlock(&mrt_lock);
2280 			rcu_read_unlock();
2281 			return -ENOMEM;
2282 		}
2283 
2284 		NETLINK_CB(skb2).portid = portid;
2285 		skb_push(skb2, sizeof(struct iphdr));
2286 		skb_reset_network_header(skb2);
2287 		iph = ip_hdr(skb2);
2288 		iph->ihl = sizeof(struct iphdr) >> 2;
2289 		iph->saddr = saddr;
2290 		iph->daddr = daddr;
2291 		iph->version = 0;
2292 		err = ipmr_cache_unresolved(mrt, vif, skb2, dev);
2293 		read_unlock(&mrt_lock);
2294 		rcu_read_unlock();
2295 		return err;
2296 	}
2297 
2298 	read_lock(&mrt_lock);
2299 	err = mr_fill_mroute(mrt, skb, &cache->_c, rtm);
2300 	read_unlock(&mrt_lock);
2301 	rcu_read_unlock();
2302 	return err;
2303 }
2304 
2305 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2306 			    u32 portid, u32 seq, struct mfc_cache *c, int cmd,
2307 			    int flags)
2308 {
2309 	struct nlmsghdr *nlh;
2310 	struct rtmsg *rtm;
2311 	int err;
2312 
2313 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2314 	if (!nlh)
2315 		return -EMSGSIZE;
2316 
2317 	rtm = nlmsg_data(nlh);
2318 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2319 	rtm->rtm_dst_len  = 32;
2320 	rtm->rtm_src_len  = 32;
2321 	rtm->rtm_tos      = 0;
2322 	rtm->rtm_table    = mrt->id;
2323 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2324 		goto nla_put_failure;
2325 	rtm->rtm_type     = RTN_MULTICAST;
2326 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2327 	if (c->_c.mfc_flags & MFC_STATIC)
2328 		rtm->rtm_protocol = RTPROT_STATIC;
2329 	else
2330 		rtm->rtm_protocol = RTPROT_MROUTED;
2331 	rtm->rtm_flags    = 0;
2332 
2333 	if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
2334 	    nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
2335 		goto nla_put_failure;
2336 	err = mr_fill_mroute(mrt, skb, &c->_c, rtm);
2337 	/* do not break the dump if cache is unresolved */
2338 	if (err < 0 && err != -ENOENT)
2339 		goto nla_put_failure;
2340 
2341 	nlmsg_end(skb, nlh);
2342 	return 0;
2343 
2344 nla_put_failure:
2345 	nlmsg_cancel(skb, nlh);
2346 	return -EMSGSIZE;
2347 }
2348 
2349 static int _ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2350 			     u32 portid, u32 seq, struct mr_mfc *c, int cmd,
2351 			     int flags)
2352 {
2353 	return ipmr_fill_mroute(mrt, skb, portid, seq, (struct mfc_cache *)c,
2354 				cmd, flags);
2355 }
2356 
2357 static size_t mroute_msgsize(bool unresolved, int maxvif)
2358 {
2359 	size_t len =
2360 		NLMSG_ALIGN(sizeof(struct rtmsg))
2361 		+ nla_total_size(4)	/* RTA_TABLE */
2362 		+ nla_total_size(4)	/* RTA_SRC */
2363 		+ nla_total_size(4)	/* RTA_DST */
2364 		;
2365 
2366 	if (!unresolved)
2367 		len = len
2368 		      + nla_total_size(4)	/* RTA_IIF */
2369 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2370 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2371 						/* RTA_MFC_STATS */
2372 		      + nla_total_size_64bit(sizeof(struct rta_mfc_stats))
2373 		;
2374 
2375 	return len;
2376 }
2377 
2378 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2379 				 int cmd)
2380 {
2381 	struct net *net = read_pnet(&mrt->net);
2382 	struct sk_buff *skb;
2383 	int err = -ENOBUFS;
2384 
2385 	skb = nlmsg_new(mroute_msgsize(mfc->_c.mfc_parent >= MAXVIFS,
2386 				       mrt->maxvif),
2387 			GFP_ATOMIC);
2388 	if (!skb)
2389 		goto errout;
2390 
2391 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2392 	if (err < 0)
2393 		goto errout;
2394 
2395 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2396 	return;
2397 
2398 errout:
2399 	kfree_skb(skb);
2400 	if (err < 0)
2401 		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2402 }
2403 
2404 static size_t igmpmsg_netlink_msgsize(size_t payloadlen)
2405 {
2406 	size_t len =
2407 		NLMSG_ALIGN(sizeof(struct rtgenmsg))
2408 		+ nla_total_size(1)	/* IPMRA_CREPORT_MSGTYPE */
2409 		+ nla_total_size(4)	/* IPMRA_CREPORT_VIF_ID */
2410 		+ nla_total_size(4)	/* IPMRA_CREPORT_SRC_ADDR */
2411 		+ nla_total_size(4)	/* IPMRA_CREPORT_DST_ADDR */
2412 					/* IPMRA_CREPORT_PKT */
2413 		+ nla_total_size(payloadlen)
2414 		;
2415 
2416 	return len;
2417 }
2418 
2419 static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt)
2420 {
2421 	struct net *net = read_pnet(&mrt->net);
2422 	struct nlmsghdr *nlh;
2423 	struct rtgenmsg *rtgenm;
2424 	struct igmpmsg *msg;
2425 	struct sk_buff *skb;
2426 	struct nlattr *nla;
2427 	int payloadlen;
2428 
2429 	payloadlen = pkt->len - sizeof(struct igmpmsg);
2430 	msg = (struct igmpmsg *)skb_network_header(pkt);
2431 
2432 	skb = nlmsg_new(igmpmsg_netlink_msgsize(payloadlen), GFP_ATOMIC);
2433 	if (!skb)
2434 		goto errout;
2435 
2436 	nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT,
2437 			sizeof(struct rtgenmsg), 0);
2438 	if (!nlh)
2439 		goto errout;
2440 	rtgenm = nlmsg_data(nlh);
2441 	rtgenm->rtgen_family = RTNL_FAMILY_IPMR;
2442 	if (nla_put_u8(skb, IPMRA_CREPORT_MSGTYPE, msg->im_msgtype) ||
2443 	    nla_put_u32(skb, IPMRA_CREPORT_VIF_ID, msg->im_vif) ||
2444 	    nla_put_in_addr(skb, IPMRA_CREPORT_SRC_ADDR,
2445 			    msg->im_src.s_addr) ||
2446 	    nla_put_in_addr(skb, IPMRA_CREPORT_DST_ADDR,
2447 			    msg->im_dst.s_addr))
2448 		goto nla_put_failure;
2449 
2450 	nla = nla_reserve(skb, IPMRA_CREPORT_PKT, payloadlen);
2451 	if (!nla || skb_copy_bits(pkt, sizeof(struct igmpmsg),
2452 				  nla_data(nla), payloadlen))
2453 		goto nla_put_failure;
2454 
2455 	nlmsg_end(skb, nlh);
2456 
2457 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE_R, NULL, GFP_ATOMIC);
2458 	return;
2459 
2460 nla_put_failure:
2461 	nlmsg_cancel(skb, nlh);
2462 errout:
2463 	kfree_skb(skb);
2464 	rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE_R, -ENOBUFS);
2465 }
2466 
2467 static int ipmr_rtm_valid_getroute_req(struct sk_buff *skb,
2468 				       const struct nlmsghdr *nlh,
2469 				       struct nlattr **tb,
2470 				       struct netlink_ext_ack *extack)
2471 {
2472 	struct rtmsg *rtm;
2473 	int i, err;
2474 
2475 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2476 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for multicast route get request");
2477 		return -EINVAL;
2478 	}
2479 
2480 	if (!netlink_strict_get_check(skb))
2481 		return nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX,
2482 				   rtm_ipv4_policy, extack);
2483 
2484 	rtm = nlmsg_data(nlh);
2485 	if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
2486 	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
2487 	    rtm->rtm_tos || rtm->rtm_table || rtm->rtm_protocol ||
2488 	    rtm->rtm_scope || rtm->rtm_type || rtm->rtm_flags) {
2489 		NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for multicast route get request");
2490 		return -EINVAL;
2491 	}
2492 
2493 	err = nlmsg_parse_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2494 				 rtm_ipv4_policy, extack);
2495 	if (err)
2496 		return err;
2497 
2498 	if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
2499 	    (tb[RTA_DST] && !rtm->rtm_dst_len)) {
2500 		NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
2501 		return -EINVAL;
2502 	}
2503 
2504 	for (i = 0; i <= RTA_MAX; i++) {
2505 		if (!tb[i])
2506 			continue;
2507 
2508 		switch (i) {
2509 		case RTA_SRC:
2510 		case RTA_DST:
2511 		case RTA_TABLE:
2512 			break;
2513 		default:
2514 			NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in multicast route get request");
2515 			return -EINVAL;
2516 		}
2517 	}
2518 
2519 	return 0;
2520 }
2521 
2522 static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2523 			     struct netlink_ext_ack *extack)
2524 {
2525 	struct net *net = sock_net(in_skb->sk);
2526 	struct nlattr *tb[RTA_MAX + 1];
2527 	struct sk_buff *skb = NULL;
2528 	struct mfc_cache *cache;
2529 	struct mr_table *mrt;
2530 	__be32 src, grp;
2531 	u32 tableid;
2532 	int err;
2533 
2534 	err = ipmr_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
2535 	if (err < 0)
2536 		goto errout;
2537 
2538 	src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2539 	grp = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2540 	tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0;
2541 
2542 	mrt = ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT);
2543 	if (!mrt) {
2544 		err = -ENOENT;
2545 		goto errout_free;
2546 	}
2547 
2548 	/* entries are added/deleted only under RTNL */
2549 	rcu_read_lock();
2550 	cache = ipmr_cache_find(mrt, src, grp);
2551 	rcu_read_unlock();
2552 	if (!cache) {
2553 		err = -ENOENT;
2554 		goto errout_free;
2555 	}
2556 
2557 	skb = nlmsg_new(mroute_msgsize(false, mrt->maxvif), GFP_KERNEL);
2558 	if (!skb) {
2559 		err = -ENOBUFS;
2560 		goto errout_free;
2561 	}
2562 
2563 	err = ipmr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid,
2564 			       nlh->nlmsg_seq, cache,
2565 			       RTM_NEWROUTE, 0);
2566 	if (err < 0)
2567 		goto errout_free;
2568 
2569 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2570 
2571 errout:
2572 	return err;
2573 
2574 errout_free:
2575 	kfree_skb(skb);
2576 	goto errout;
2577 }
2578 
2579 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2580 {
2581 	struct fib_dump_filter filter = {};
2582 	int err;
2583 
2584 	if (cb->strict_check) {
2585 		err = ip_valid_fib_dump_req(sock_net(skb->sk), cb->nlh,
2586 					    &filter, cb);
2587 		if (err < 0)
2588 			return err;
2589 	}
2590 
2591 	if (filter.table_id) {
2592 		struct mr_table *mrt;
2593 
2594 		mrt = ipmr_get_table(sock_net(skb->sk), filter.table_id);
2595 		if (!mrt) {
2596 			if (filter.dump_all_families)
2597 				return skb->len;
2598 
2599 			NL_SET_ERR_MSG(cb->extack, "ipv4: MR table does not exist");
2600 			return -ENOENT;
2601 		}
2602 		err = mr_table_dump(mrt, skb, cb, _ipmr_fill_mroute,
2603 				    &mfc_unres_lock, &filter);
2604 		return skb->len ? : err;
2605 	}
2606 
2607 	return mr_rtm_dumproute(skb, cb, ipmr_mr_table_iter,
2608 				_ipmr_fill_mroute, &mfc_unres_lock, &filter);
2609 }
2610 
2611 static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {
2612 	[RTA_SRC]	= { .type = NLA_U32 },
2613 	[RTA_DST]	= { .type = NLA_U32 },
2614 	[RTA_IIF]	= { .type = NLA_U32 },
2615 	[RTA_TABLE]	= { .type = NLA_U32 },
2616 	[RTA_MULTIPATH]	= { .len = sizeof(struct rtnexthop) },
2617 };
2618 
2619 static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol)
2620 {
2621 	switch (rtm_protocol) {
2622 	case RTPROT_STATIC:
2623 	case RTPROT_MROUTED:
2624 		return true;
2625 	}
2626 	return false;
2627 }
2628 
2629 static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc)
2630 {
2631 	struct rtnexthop *rtnh = nla_data(nla);
2632 	int remaining = nla_len(nla), vifi = 0;
2633 
2634 	while (rtnh_ok(rtnh, remaining)) {
2635 		mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops;
2636 		if (++vifi == MAXVIFS)
2637 			break;
2638 		rtnh = rtnh_next(rtnh, &remaining);
2639 	}
2640 
2641 	return remaining > 0 ? -EINVAL : vifi;
2642 }
2643 
2644 /* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */
2645 static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
2646 			    struct mfcctl *mfcc, int *mrtsock,
2647 			    struct mr_table **mrtret,
2648 			    struct netlink_ext_ack *extack)
2649 {
2650 	struct net_device *dev = NULL;
2651 	u32 tblid = RT_TABLE_DEFAULT;
2652 	struct mr_table *mrt;
2653 	struct nlattr *attr;
2654 	struct rtmsg *rtm;
2655 	int ret, rem;
2656 
2657 	ret = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipmr_policy,
2658 			     extack);
2659 	if (ret < 0)
2660 		goto out;
2661 	rtm = nlmsg_data(nlh);
2662 
2663 	ret = -EINVAL;
2664 	if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 ||
2665 	    rtm->rtm_type != RTN_MULTICAST ||
2666 	    rtm->rtm_scope != RT_SCOPE_UNIVERSE ||
2667 	    !ipmr_rtm_validate_proto(rtm->rtm_protocol))
2668 		goto out;
2669 
2670 	memset(mfcc, 0, sizeof(*mfcc));
2671 	mfcc->mfcc_parent = -1;
2672 	ret = 0;
2673 	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) {
2674 		switch (nla_type(attr)) {
2675 		case RTA_SRC:
2676 			mfcc->mfcc_origin.s_addr = nla_get_be32(attr);
2677 			break;
2678 		case RTA_DST:
2679 			mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr);
2680 			break;
2681 		case RTA_IIF:
2682 			dev = __dev_get_by_index(net, nla_get_u32(attr));
2683 			if (!dev) {
2684 				ret = -ENODEV;
2685 				goto out;
2686 			}
2687 			break;
2688 		case RTA_MULTIPATH:
2689 			if (ipmr_nla_get_ttls(attr, mfcc) < 0) {
2690 				ret = -EINVAL;
2691 				goto out;
2692 			}
2693 			break;
2694 		case RTA_PREFSRC:
2695 			ret = 1;
2696 			break;
2697 		case RTA_TABLE:
2698 			tblid = nla_get_u32(attr);
2699 			break;
2700 		}
2701 	}
2702 	mrt = ipmr_get_table(net, tblid);
2703 	if (!mrt) {
2704 		ret = -ENOENT;
2705 		goto out;
2706 	}
2707 	*mrtret = mrt;
2708 	*mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0;
2709 	if (dev)
2710 		mfcc->mfcc_parent = ipmr_find_vif(mrt, dev);
2711 
2712 out:
2713 	return ret;
2714 }
2715 
2716 /* takes care of both newroute and delroute */
2717 static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh,
2718 			  struct netlink_ext_ack *extack)
2719 {
2720 	struct net *net = sock_net(skb->sk);
2721 	int ret, mrtsock, parent;
2722 	struct mr_table *tbl;
2723 	struct mfcctl mfcc;
2724 
2725 	mrtsock = 0;
2726 	tbl = NULL;
2727 	ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl, extack);
2728 	if (ret < 0)
2729 		return ret;
2730 
2731 	parent = ret ? mfcc.mfcc_parent : -1;
2732 	if (nlh->nlmsg_type == RTM_NEWROUTE)
2733 		return ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent);
2734 	else
2735 		return ipmr_mfc_delete(tbl, &mfcc, parent);
2736 }
2737 
2738 static bool ipmr_fill_table(struct mr_table *mrt, struct sk_buff *skb)
2739 {
2740 	u32 queue_len = atomic_read(&mrt->cache_resolve_queue_len);
2741 
2742 	if (nla_put_u32(skb, IPMRA_TABLE_ID, mrt->id) ||
2743 	    nla_put_u32(skb, IPMRA_TABLE_CACHE_RES_QUEUE_LEN, queue_len) ||
2744 	    nla_put_s32(skb, IPMRA_TABLE_MROUTE_REG_VIF_NUM,
2745 			mrt->mroute_reg_vif_num) ||
2746 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_ASSERT,
2747 		       mrt->mroute_do_assert) ||
2748 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_PIM, mrt->mroute_do_pim) ||
2749 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_WRVIFWHOLE,
2750 		       mrt->mroute_do_wrvifwhole))
2751 		return false;
2752 
2753 	return true;
2754 }
2755 
2756 static bool ipmr_fill_vif(struct mr_table *mrt, u32 vifid, struct sk_buff *skb)
2757 {
2758 	struct nlattr *vif_nest;
2759 	struct vif_device *vif;
2760 
2761 	/* if the VIF doesn't exist just continue */
2762 	if (!VIF_EXISTS(mrt, vifid))
2763 		return true;
2764 
2765 	vif = &mrt->vif_table[vifid];
2766 	vif_nest = nla_nest_start(skb, IPMRA_VIF);
2767 	if (!vif_nest)
2768 		return false;
2769 	if (nla_put_u32(skb, IPMRA_VIFA_IFINDEX, vif->dev->ifindex) ||
2770 	    nla_put_u32(skb, IPMRA_VIFA_VIF_ID, vifid) ||
2771 	    nla_put_u16(skb, IPMRA_VIFA_FLAGS, vif->flags) ||
2772 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_IN, vif->bytes_in,
2773 			      IPMRA_VIFA_PAD) ||
2774 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_OUT, vif->bytes_out,
2775 			      IPMRA_VIFA_PAD) ||
2776 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_IN, vif->pkt_in,
2777 			      IPMRA_VIFA_PAD) ||
2778 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_OUT, vif->pkt_out,
2779 			      IPMRA_VIFA_PAD) ||
2780 	    nla_put_be32(skb, IPMRA_VIFA_LOCAL_ADDR, vif->local) ||
2781 	    nla_put_be32(skb, IPMRA_VIFA_REMOTE_ADDR, vif->remote)) {
2782 		nla_nest_cancel(skb, vif_nest);
2783 		return false;
2784 	}
2785 	nla_nest_end(skb, vif_nest);
2786 
2787 	return true;
2788 }
2789 
2790 static int ipmr_valid_dumplink(const struct nlmsghdr *nlh,
2791 			       struct netlink_ext_ack *extack)
2792 {
2793 	struct ifinfomsg *ifm;
2794 
2795 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) {
2796 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for ipmr link dump");
2797 		return -EINVAL;
2798 	}
2799 
2800 	if (nlmsg_attrlen(nlh, sizeof(*ifm))) {
2801 		NL_SET_ERR_MSG(extack, "Invalid data after header in ipmr link dump");
2802 		return -EINVAL;
2803 	}
2804 
2805 	ifm = nlmsg_data(nlh);
2806 	if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags ||
2807 	    ifm->ifi_change || ifm->ifi_index) {
2808 		NL_SET_ERR_MSG(extack, "Invalid values in header for ipmr link dump request");
2809 		return -EINVAL;
2810 	}
2811 
2812 	return 0;
2813 }
2814 
2815 static int ipmr_rtm_dumplink(struct sk_buff *skb, struct netlink_callback *cb)
2816 {
2817 	struct net *net = sock_net(skb->sk);
2818 	struct nlmsghdr *nlh = NULL;
2819 	unsigned int t = 0, s_t;
2820 	unsigned int e = 0, s_e;
2821 	struct mr_table *mrt;
2822 
2823 	if (cb->strict_check) {
2824 		int err = ipmr_valid_dumplink(cb->nlh, cb->extack);
2825 
2826 		if (err < 0)
2827 			return err;
2828 	}
2829 
2830 	s_t = cb->args[0];
2831 	s_e = cb->args[1];
2832 
2833 	ipmr_for_each_table(mrt, net) {
2834 		struct nlattr *vifs, *af;
2835 		struct ifinfomsg *hdr;
2836 		u32 i;
2837 
2838 		if (t < s_t)
2839 			goto skip_table;
2840 		nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
2841 				cb->nlh->nlmsg_seq, RTM_NEWLINK,
2842 				sizeof(*hdr), NLM_F_MULTI);
2843 		if (!nlh)
2844 			break;
2845 
2846 		hdr = nlmsg_data(nlh);
2847 		memset(hdr, 0, sizeof(*hdr));
2848 		hdr->ifi_family = RTNL_FAMILY_IPMR;
2849 
2850 		af = nla_nest_start(skb, IFLA_AF_SPEC);
2851 		if (!af) {
2852 			nlmsg_cancel(skb, nlh);
2853 			goto out;
2854 		}
2855 
2856 		if (!ipmr_fill_table(mrt, skb)) {
2857 			nlmsg_cancel(skb, nlh);
2858 			goto out;
2859 		}
2860 
2861 		vifs = nla_nest_start(skb, IPMRA_TABLE_VIFS);
2862 		if (!vifs) {
2863 			nla_nest_end(skb, af);
2864 			nlmsg_end(skb, nlh);
2865 			goto out;
2866 		}
2867 		for (i = 0; i < mrt->maxvif; i++) {
2868 			if (e < s_e)
2869 				goto skip_entry;
2870 			if (!ipmr_fill_vif(mrt, i, skb)) {
2871 				nla_nest_end(skb, vifs);
2872 				nla_nest_end(skb, af);
2873 				nlmsg_end(skb, nlh);
2874 				goto out;
2875 			}
2876 skip_entry:
2877 			e++;
2878 		}
2879 		s_e = 0;
2880 		e = 0;
2881 		nla_nest_end(skb, vifs);
2882 		nla_nest_end(skb, af);
2883 		nlmsg_end(skb, nlh);
2884 skip_table:
2885 		t++;
2886 	}
2887 
2888 out:
2889 	cb->args[1] = e;
2890 	cb->args[0] = t;
2891 
2892 	return skb->len;
2893 }
2894 
2895 #ifdef CONFIG_PROC_FS
2896 /* The /proc interfaces to multicast routing :
2897  * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2898  */
2899 
2900 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2901 	__acquires(mrt_lock)
2902 {
2903 	struct mr_vif_iter *iter = seq->private;
2904 	struct net *net = seq_file_net(seq);
2905 	struct mr_table *mrt;
2906 
2907 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2908 	if (!mrt)
2909 		return ERR_PTR(-ENOENT);
2910 
2911 	iter->mrt = mrt;
2912 
2913 	read_lock(&mrt_lock);
2914 	return mr_vif_seq_start(seq, pos);
2915 }
2916 
2917 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2918 	__releases(mrt_lock)
2919 {
2920 	read_unlock(&mrt_lock);
2921 }
2922 
2923 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2924 {
2925 	struct mr_vif_iter *iter = seq->private;
2926 	struct mr_table *mrt = iter->mrt;
2927 
2928 	if (v == SEQ_START_TOKEN) {
2929 		seq_puts(seq,
2930 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2931 	} else {
2932 		const struct vif_device *vif = v;
2933 		const char *name =  vif->dev ?
2934 				    vif->dev->name : "none";
2935 
2936 		seq_printf(seq,
2937 			   "%2td %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2938 			   vif - mrt->vif_table,
2939 			   name, vif->bytes_in, vif->pkt_in,
2940 			   vif->bytes_out, vif->pkt_out,
2941 			   vif->flags, vif->local, vif->remote);
2942 	}
2943 	return 0;
2944 }
2945 
2946 static const struct seq_operations ipmr_vif_seq_ops = {
2947 	.start = ipmr_vif_seq_start,
2948 	.next  = mr_vif_seq_next,
2949 	.stop  = ipmr_vif_seq_stop,
2950 	.show  = ipmr_vif_seq_show,
2951 };
2952 
2953 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2954 {
2955 	struct net *net = seq_file_net(seq);
2956 	struct mr_table *mrt;
2957 
2958 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2959 	if (!mrt)
2960 		return ERR_PTR(-ENOENT);
2961 
2962 	return mr_mfc_seq_start(seq, pos, mrt, &mfc_unres_lock);
2963 }
2964 
2965 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2966 {
2967 	int n;
2968 
2969 	if (v == SEQ_START_TOKEN) {
2970 		seq_puts(seq,
2971 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2972 	} else {
2973 		const struct mfc_cache *mfc = v;
2974 		const struct mr_mfc_iter *it = seq->private;
2975 		const struct mr_table *mrt = it->mrt;
2976 
2977 		seq_printf(seq, "%08X %08X %-3hd",
2978 			   (__force u32) mfc->mfc_mcastgrp,
2979 			   (__force u32) mfc->mfc_origin,
2980 			   mfc->_c.mfc_parent);
2981 
2982 		if (it->cache != &mrt->mfc_unres_queue) {
2983 			seq_printf(seq, " %8lu %8lu %8lu",
2984 				   mfc->_c.mfc_un.res.pkt,
2985 				   mfc->_c.mfc_un.res.bytes,
2986 				   mfc->_c.mfc_un.res.wrong_if);
2987 			for (n = mfc->_c.mfc_un.res.minvif;
2988 			     n < mfc->_c.mfc_un.res.maxvif; n++) {
2989 				if (VIF_EXISTS(mrt, n) &&
2990 				    mfc->_c.mfc_un.res.ttls[n] < 255)
2991 					seq_printf(seq,
2992 					   " %2d:%-3d",
2993 					   n, mfc->_c.mfc_un.res.ttls[n]);
2994 			}
2995 		} else {
2996 			/* unresolved mfc_caches don't contain
2997 			 * pkt, bytes and wrong_if values
2998 			 */
2999 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
3000 		}
3001 		seq_putc(seq, '\n');
3002 	}
3003 	return 0;
3004 }
3005 
3006 static const struct seq_operations ipmr_mfc_seq_ops = {
3007 	.start = ipmr_mfc_seq_start,
3008 	.next  = mr_mfc_seq_next,
3009 	.stop  = mr_mfc_seq_stop,
3010 	.show  = ipmr_mfc_seq_show,
3011 };
3012 #endif
3013 
3014 #ifdef CONFIG_IP_PIMSM_V2
3015 static const struct net_protocol pim_protocol = {
3016 	.handler	=	pim_rcv,
3017 	.netns_ok	=	1,
3018 };
3019 #endif
3020 
3021 static unsigned int ipmr_seq_read(struct net *net)
3022 {
3023 	ASSERT_RTNL();
3024 
3025 	return net->ipv4.ipmr_seq + ipmr_rules_seq_read(net);
3026 }
3027 
3028 static int ipmr_dump(struct net *net, struct notifier_block *nb)
3029 {
3030 	return mr_dump(net, nb, RTNL_FAMILY_IPMR, ipmr_rules_dump,
3031 		       ipmr_mr_table_iter, &mrt_lock);
3032 }
3033 
3034 static const struct fib_notifier_ops ipmr_notifier_ops_template = {
3035 	.family		= RTNL_FAMILY_IPMR,
3036 	.fib_seq_read	= ipmr_seq_read,
3037 	.fib_dump	= ipmr_dump,
3038 	.owner		= THIS_MODULE,
3039 };
3040 
3041 static int __net_init ipmr_notifier_init(struct net *net)
3042 {
3043 	struct fib_notifier_ops *ops;
3044 
3045 	net->ipv4.ipmr_seq = 0;
3046 
3047 	ops = fib_notifier_ops_register(&ipmr_notifier_ops_template, net);
3048 	if (IS_ERR(ops))
3049 		return PTR_ERR(ops);
3050 	net->ipv4.ipmr_notifier_ops = ops;
3051 
3052 	return 0;
3053 }
3054 
3055 static void __net_exit ipmr_notifier_exit(struct net *net)
3056 {
3057 	fib_notifier_ops_unregister(net->ipv4.ipmr_notifier_ops);
3058 	net->ipv4.ipmr_notifier_ops = NULL;
3059 }
3060 
3061 /* Setup for IP multicast routing */
3062 static int __net_init ipmr_net_init(struct net *net)
3063 {
3064 	int err;
3065 
3066 	err = ipmr_notifier_init(net);
3067 	if (err)
3068 		goto ipmr_notifier_fail;
3069 
3070 	err = ipmr_rules_init(net);
3071 	if (err < 0)
3072 		goto ipmr_rules_fail;
3073 
3074 #ifdef CONFIG_PROC_FS
3075 	err = -ENOMEM;
3076 	if (!proc_create_net("ip_mr_vif", 0, net->proc_net, &ipmr_vif_seq_ops,
3077 			sizeof(struct mr_vif_iter)))
3078 		goto proc_vif_fail;
3079 	if (!proc_create_net("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_seq_ops,
3080 			sizeof(struct mr_mfc_iter)))
3081 		goto proc_cache_fail;
3082 #endif
3083 	return 0;
3084 
3085 #ifdef CONFIG_PROC_FS
3086 proc_cache_fail:
3087 	remove_proc_entry("ip_mr_vif", net->proc_net);
3088 proc_vif_fail:
3089 	ipmr_rules_exit(net);
3090 #endif
3091 ipmr_rules_fail:
3092 	ipmr_notifier_exit(net);
3093 ipmr_notifier_fail:
3094 	return err;
3095 }
3096 
3097 static void __net_exit ipmr_net_exit(struct net *net)
3098 {
3099 #ifdef CONFIG_PROC_FS
3100 	remove_proc_entry("ip_mr_cache", net->proc_net);
3101 	remove_proc_entry("ip_mr_vif", net->proc_net);
3102 #endif
3103 	ipmr_notifier_exit(net);
3104 	ipmr_rules_exit(net);
3105 }
3106 
3107 static struct pernet_operations ipmr_net_ops = {
3108 	.init = ipmr_net_init,
3109 	.exit = ipmr_net_exit,
3110 };
3111 
3112 int __init ip_mr_init(void)
3113 {
3114 	int err;
3115 
3116 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
3117 				       sizeof(struct mfc_cache),
3118 				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
3119 				       NULL);
3120 
3121 	err = register_pernet_subsys(&ipmr_net_ops);
3122 	if (err)
3123 		goto reg_pernet_fail;
3124 
3125 	err = register_netdevice_notifier(&ip_mr_notifier);
3126 	if (err)
3127 		goto reg_notif_fail;
3128 #ifdef CONFIG_IP_PIMSM_V2
3129 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
3130 		pr_err("%s: can't add PIM protocol\n", __func__);
3131 		err = -EAGAIN;
3132 		goto add_proto_fail;
3133 	}
3134 #endif
3135 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
3136 		      ipmr_rtm_getroute, ipmr_rtm_dumproute, 0);
3137 	rtnl_register(RTNL_FAMILY_IPMR, RTM_NEWROUTE,
3138 		      ipmr_rtm_route, NULL, 0);
3139 	rtnl_register(RTNL_FAMILY_IPMR, RTM_DELROUTE,
3140 		      ipmr_rtm_route, NULL, 0);
3141 
3142 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETLINK,
3143 		      NULL, ipmr_rtm_dumplink, 0);
3144 	return 0;
3145 
3146 #ifdef CONFIG_IP_PIMSM_V2
3147 add_proto_fail:
3148 	unregister_netdevice_notifier(&ip_mr_notifier);
3149 #endif
3150 reg_notif_fail:
3151 	unregister_pernet_subsys(&ipmr_net_ops);
3152 reg_pernet_fail:
3153 	kmem_cache_destroy(mrt_cachep);
3154 	return err;
3155 }
3156