xref: /linux/net/ipv4/ipmr.c (revision b24413180f5600bcb3bb70fbed5cf186b60864bd)
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/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 #include <net/nexthop.h>
70 
71 struct ipmr_rule {
72 	struct fib_rule		common;
73 };
74 
75 struct ipmr_result {
76 	struct mr_table		*mrt;
77 };
78 
79 /* Big lock, protecting vif table, mrt cache and mroute socket state.
80  * Note that the changes are semaphored via rtnl_lock.
81  */
82 
83 static DEFINE_RWLOCK(mrt_lock);
84 
85 /* Multicast router control variables */
86 
87 /* Special spinlock for queue of unresolved entries */
88 static DEFINE_SPINLOCK(mfc_unres_lock);
89 
90 /* We return to original Alan's scheme. Hash table of resolved
91  * entries is changed only in process context and protected
92  * with weak lock mrt_lock. Queue of unresolved entries is protected
93  * with strong spinlock mfc_unres_lock.
94  *
95  * In this case data path is free of exclusive locks at all.
96  */
97 
98 static struct kmem_cache *mrt_cachep __read_mostly;
99 
100 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
101 static void ipmr_free_table(struct mr_table *mrt);
102 
103 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
104 			  struct net_device *dev, struct sk_buff *skb,
105 			  struct mfc_cache *cache, int local);
106 static int ipmr_cache_report(struct mr_table *mrt,
107 			     struct sk_buff *pkt, vifi_t vifi, int assert);
108 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
109 			      struct mfc_cache *c, struct rtmsg *rtm);
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(unsigned long arg);
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_get_table(struct net *net, u32 id)
121 {
122 	struct mr_table *mrt;
123 
124 	ipmr_for_each_table(mrt, net) {
125 		if (mrt->id == id)
126 			return mrt;
127 	}
128 	return NULL;
129 }
130 
131 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
132 			   struct mr_table **mrt)
133 {
134 	int err;
135 	struct ipmr_result res;
136 	struct fib_lookup_arg arg = {
137 		.result = &res,
138 		.flags = FIB_LOOKUP_NOREF,
139 	};
140 
141 	/* update flow if oif or iif point to device enslaved to l3mdev */
142 	l3mdev_update_flow(net, flowi4_to_flowi(flp4));
143 
144 	err = fib_rules_lookup(net->ipv4.mr_rules_ops,
145 			       flowi4_to_flowi(flp4), 0, &arg);
146 	if (err < 0)
147 		return err;
148 	*mrt = res.mrt;
149 	return 0;
150 }
151 
152 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
153 			    int flags, struct fib_lookup_arg *arg)
154 {
155 	struct ipmr_result *res = arg->result;
156 	struct mr_table *mrt;
157 
158 	switch (rule->action) {
159 	case FR_ACT_TO_TBL:
160 		break;
161 	case FR_ACT_UNREACHABLE:
162 		return -ENETUNREACH;
163 	case FR_ACT_PROHIBIT:
164 		return -EACCES;
165 	case FR_ACT_BLACKHOLE:
166 	default:
167 		return -EINVAL;
168 	}
169 
170 	arg->table = fib_rule_get_table(rule, arg);
171 
172 	mrt = ipmr_get_table(rule->fr_net, arg->table);
173 	if (!mrt)
174 		return -EAGAIN;
175 	res->mrt = mrt;
176 	return 0;
177 }
178 
179 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
180 {
181 	return 1;
182 }
183 
184 static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
185 	FRA_GENERIC_POLICY,
186 };
187 
188 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
189 			       struct fib_rule_hdr *frh, struct nlattr **tb)
190 {
191 	return 0;
192 }
193 
194 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
195 			     struct nlattr **tb)
196 {
197 	return 1;
198 }
199 
200 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
201 			  struct fib_rule_hdr *frh)
202 {
203 	frh->dst_len = 0;
204 	frh->src_len = 0;
205 	frh->tos     = 0;
206 	return 0;
207 }
208 
209 static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
210 	.family		= RTNL_FAMILY_IPMR,
211 	.rule_size	= sizeof(struct ipmr_rule),
212 	.addr_size	= sizeof(u32),
213 	.action		= ipmr_rule_action,
214 	.match		= ipmr_rule_match,
215 	.configure	= ipmr_rule_configure,
216 	.compare	= ipmr_rule_compare,
217 	.fill		= ipmr_rule_fill,
218 	.nlgroup	= RTNLGRP_IPV4_RULE,
219 	.policy		= ipmr_rule_policy,
220 	.owner		= THIS_MODULE,
221 };
222 
223 static int __net_init ipmr_rules_init(struct net *net)
224 {
225 	struct fib_rules_ops *ops;
226 	struct mr_table *mrt;
227 	int err;
228 
229 	ops = fib_rules_register(&ipmr_rules_ops_template, net);
230 	if (IS_ERR(ops))
231 		return PTR_ERR(ops);
232 
233 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
234 
235 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
236 	if (IS_ERR(mrt)) {
237 		err = PTR_ERR(mrt);
238 		goto err1;
239 	}
240 
241 	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
242 	if (err < 0)
243 		goto err2;
244 
245 	net->ipv4.mr_rules_ops = ops;
246 	return 0;
247 
248 err2:
249 	ipmr_free_table(mrt);
250 err1:
251 	fib_rules_unregister(ops);
252 	return err;
253 }
254 
255 static void __net_exit ipmr_rules_exit(struct net *net)
256 {
257 	struct mr_table *mrt, *next;
258 
259 	rtnl_lock();
260 	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
261 		list_del(&mrt->list);
262 		ipmr_free_table(mrt);
263 	}
264 	fib_rules_unregister(net->ipv4.mr_rules_ops);
265 	rtnl_unlock();
266 }
267 #else
268 #define ipmr_for_each_table(mrt, net) \
269 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
270 
271 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
272 {
273 	return net->ipv4.mrt;
274 }
275 
276 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
277 			   struct mr_table **mrt)
278 {
279 	*mrt = net->ipv4.mrt;
280 	return 0;
281 }
282 
283 static int __net_init ipmr_rules_init(struct net *net)
284 {
285 	struct mr_table *mrt;
286 
287 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
288 	if (IS_ERR(mrt))
289 		return PTR_ERR(mrt);
290 	net->ipv4.mrt = mrt;
291 	return 0;
292 }
293 
294 static void __net_exit ipmr_rules_exit(struct net *net)
295 {
296 	rtnl_lock();
297 	ipmr_free_table(net->ipv4.mrt);
298 	net->ipv4.mrt = NULL;
299 	rtnl_unlock();
300 }
301 #endif
302 
303 static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
304 				const void *ptr)
305 {
306 	const struct mfc_cache_cmp_arg *cmparg = arg->key;
307 	struct mfc_cache *c = (struct mfc_cache *)ptr;
308 
309 	return cmparg->mfc_mcastgrp != c->mfc_mcastgrp ||
310 	       cmparg->mfc_origin != c->mfc_origin;
311 }
312 
313 static const struct rhashtable_params ipmr_rht_params = {
314 	.head_offset = offsetof(struct mfc_cache, mnode),
315 	.key_offset = offsetof(struct mfc_cache, cmparg),
316 	.key_len = sizeof(struct mfc_cache_cmp_arg),
317 	.nelem_hint = 3,
318 	.locks_mul = 1,
319 	.obj_cmpfn = ipmr_hash_cmp,
320 	.automatic_shrinking = true,
321 };
322 
323 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
324 {
325 	struct mr_table *mrt;
326 
327 	/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
328 	if (id != RT_TABLE_DEFAULT && id >= 1000000000)
329 		return ERR_PTR(-EINVAL);
330 
331 	mrt = ipmr_get_table(net, id);
332 	if (mrt)
333 		return mrt;
334 
335 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
336 	if (!mrt)
337 		return ERR_PTR(-ENOMEM);
338 	write_pnet(&mrt->net, net);
339 	mrt->id = id;
340 
341 	rhltable_init(&mrt->mfc_hash, &ipmr_rht_params);
342 	INIT_LIST_HEAD(&mrt->mfc_cache_list);
343 	INIT_LIST_HEAD(&mrt->mfc_unres_queue);
344 
345 	setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
346 		    (unsigned long)mrt);
347 
348 	mrt->mroute_reg_vif_num = -1;
349 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
350 	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
351 #endif
352 	return mrt;
353 }
354 
355 static void ipmr_free_table(struct mr_table *mrt)
356 {
357 	del_timer_sync(&mrt->ipmr_expire_timer);
358 	mroute_clean_tables(mrt, true);
359 	rhltable_destroy(&mrt->mfc_hash);
360 	kfree(mrt);
361 }
362 
363 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
364 
365 static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
366 {
367 	struct net *net = dev_net(dev);
368 
369 	dev_close(dev);
370 
371 	dev = __dev_get_by_name(net, "tunl0");
372 	if (dev) {
373 		const struct net_device_ops *ops = dev->netdev_ops;
374 		struct ifreq ifr;
375 		struct ip_tunnel_parm p;
376 
377 		memset(&p, 0, sizeof(p));
378 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
379 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
380 		p.iph.version = 4;
381 		p.iph.ihl = 5;
382 		p.iph.protocol = IPPROTO_IPIP;
383 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
384 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
385 
386 		if (ops->ndo_do_ioctl) {
387 			mm_segment_t oldfs = get_fs();
388 
389 			set_fs(KERNEL_DS);
390 			ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
391 			set_fs(oldfs);
392 		}
393 	}
394 }
395 
396 /* Initialize ipmr pimreg/tunnel in_device */
397 static bool ipmr_init_vif_indev(const struct net_device *dev)
398 {
399 	struct in_device *in_dev;
400 
401 	ASSERT_RTNL();
402 
403 	in_dev = __in_dev_get_rtnl(dev);
404 	if (!in_dev)
405 		return false;
406 	ipv4_devconf_setall(in_dev);
407 	neigh_parms_data_state_setall(in_dev->arp_parms);
408 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
409 
410 	return true;
411 }
412 
413 static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
414 {
415 	struct net_device  *dev;
416 
417 	dev = __dev_get_by_name(net, "tunl0");
418 
419 	if (dev) {
420 		const struct net_device_ops *ops = dev->netdev_ops;
421 		int err;
422 		struct ifreq ifr;
423 		struct ip_tunnel_parm p;
424 
425 		memset(&p, 0, sizeof(p));
426 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
427 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
428 		p.iph.version = 4;
429 		p.iph.ihl = 5;
430 		p.iph.protocol = IPPROTO_IPIP;
431 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
432 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
433 
434 		if (ops->ndo_do_ioctl) {
435 			mm_segment_t oldfs = get_fs();
436 
437 			set_fs(KERNEL_DS);
438 			err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
439 			set_fs(oldfs);
440 		} else {
441 			err = -EOPNOTSUPP;
442 		}
443 		dev = NULL;
444 
445 		if (err == 0 &&
446 		    (dev = __dev_get_by_name(net, p.name)) != NULL) {
447 			dev->flags |= IFF_MULTICAST;
448 			if (!ipmr_init_vif_indev(dev))
449 				goto failure;
450 			if (dev_open(dev))
451 				goto failure;
452 			dev_hold(dev);
453 		}
454 	}
455 	return dev;
456 
457 failure:
458 	unregister_netdevice(dev);
459 	return NULL;
460 }
461 
462 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
463 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
464 {
465 	struct net *net = dev_net(dev);
466 	struct mr_table *mrt;
467 	struct flowi4 fl4 = {
468 		.flowi4_oif	= dev->ifindex,
469 		.flowi4_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
470 		.flowi4_mark	= skb->mark,
471 	};
472 	int err;
473 
474 	err = ipmr_fib_lookup(net, &fl4, &mrt);
475 	if (err < 0) {
476 		kfree_skb(skb);
477 		return err;
478 	}
479 
480 	read_lock(&mrt_lock);
481 	dev->stats.tx_bytes += skb->len;
482 	dev->stats.tx_packets++;
483 	ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
484 	read_unlock(&mrt_lock);
485 	kfree_skb(skb);
486 	return NETDEV_TX_OK;
487 }
488 
489 static int reg_vif_get_iflink(const struct net_device *dev)
490 {
491 	return 0;
492 }
493 
494 static const struct net_device_ops reg_vif_netdev_ops = {
495 	.ndo_start_xmit	= reg_vif_xmit,
496 	.ndo_get_iflink = reg_vif_get_iflink,
497 };
498 
499 static void reg_vif_setup(struct net_device *dev)
500 {
501 	dev->type		= ARPHRD_PIMREG;
502 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
503 	dev->flags		= IFF_NOARP;
504 	dev->netdev_ops		= &reg_vif_netdev_ops;
505 	dev->needs_free_netdev	= true;
506 	dev->features		|= NETIF_F_NETNS_LOCAL;
507 }
508 
509 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
510 {
511 	struct net_device *dev;
512 	char name[IFNAMSIZ];
513 
514 	if (mrt->id == RT_TABLE_DEFAULT)
515 		sprintf(name, "pimreg");
516 	else
517 		sprintf(name, "pimreg%u", mrt->id);
518 
519 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
520 
521 	if (!dev)
522 		return NULL;
523 
524 	dev_net_set(dev, net);
525 
526 	if (register_netdevice(dev)) {
527 		free_netdev(dev);
528 		return NULL;
529 	}
530 
531 	if (!ipmr_init_vif_indev(dev))
532 		goto failure;
533 	if (dev_open(dev))
534 		goto failure;
535 
536 	dev_hold(dev);
537 
538 	return dev;
539 
540 failure:
541 	unregister_netdevice(dev);
542 	return NULL;
543 }
544 
545 /* called with rcu_read_lock() */
546 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
547 		     unsigned int pimlen)
548 {
549 	struct net_device *reg_dev = NULL;
550 	struct iphdr *encap;
551 
552 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
553 	/* Check that:
554 	 * a. packet is really sent to a multicast group
555 	 * b. packet is not a NULL-REGISTER
556 	 * c. packet is not truncated
557 	 */
558 	if (!ipv4_is_multicast(encap->daddr) ||
559 	    encap->tot_len == 0 ||
560 	    ntohs(encap->tot_len) + pimlen > skb->len)
561 		return 1;
562 
563 	read_lock(&mrt_lock);
564 	if (mrt->mroute_reg_vif_num >= 0)
565 		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
566 	read_unlock(&mrt_lock);
567 
568 	if (!reg_dev)
569 		return 1;
570 
571 	skb->mac_header = skb->network_header;
572 	skb_pull(skb, (u8 *)encap - skb->data);
573 	skb_reset_network_header(skb);
574 	skb->protocol = htons(ETH_P_IP);
575 	skb->ip_summed = CHECKSUM_NONE;
576 
577 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
578 
579 	netif_rx(skb);
580 
581 	return NET_RX_SUCCESS;
582 }
583 #else
584 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
585 {
586 	return NULL;
587 }
588 #endif
589 
590 /**
591  *	vif_delete - Delete a VIF entry
592  *	@notify: Set to 1, if the caller is a notifier_call
593  */
594 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
595 		      struct list_head *head)
596 {
597 	struct vif_device *v;
598 	struct net_device *dev;
599 	struct in_device *in_dev;
600 
601 	if (vifi < 0 || vifi >= mrt->maxvif)
602 		return -EADDRNOTAVAIL;
603 
604 	v = &mrt->vif_table[vifi];
605 
606 	write_lock_bh(&mrt_lock);
607 	dev = v->dev;
608 	v->dev = NULL;
609 
610 	if (!dev) {
611 		write_unlock_bh(&mrt_lock);
612 		return -EADDRNOTAVAIL;
613 	}
614 
615 	if (vifi == mrt->mroute_reg_vif_num)
616 		mrt->mroute_reg_vif_num = -1;
617 
618 	if (vifi + 1 == mrt->maxvif) {
619 		int tmp;
620 
621 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
622 			if (VIF_EXISTS(mrt, tmp))
623 				break;
624 		}
625 		mrt->maxvif = tmp+1;
626 	}
627 
628 	write_unlock_bh(&mrt_lock);
629 
630 	dev_set_allmulti(dev, -1);
631 
632 	in_dev = __in_dev_get_rtnl(dev);
633 	if (in_dev) {
634 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
635 		inet_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
636 					    NETCONFA_MC_FORWARDING,
637 					    dev->ifindex, &in_dev->cnf);
638 		ip_rt_multicast_event(in_dev);
639 	}
640 
641 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
642 		unregister_netdevice_queue(dev, head);
643 
644 	dev_put(dev);
645 	return 0;
646 }
647 
648 static void ipmr_cache_free_rcu(struct rcu_head *head)
649 {
650 	struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
651 
652 	kmem_cache_free(mrt_cachep, c);
653 }
654 
655 static inline void ipmr_cache_free(struct mfc_cache *c)
656 {
657 	call_rcu(&c->rcu, ipmr_cache_free_rcu);
658 }
659 
660 /* Destroy an unresolved cache entry, killing queued skbs
661  * and reporting error to netlink readers.
662  */
663 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
664 {
665 	struct net *net = read_pnet(&mrt->net);
666 	struct sk_buff *skb;
667 	struct nlmsgerr *e;
668 
669 	atomic_dec(&mrt->cache_resolve_queue_len);
670 
671 	while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
672 		if (ip_hdr(skb)->version == 0) {
673 			struct nlmsghdr *nlh = skb_pull(skb,
674 							sizeof(struct iphdr));
675 			nlh->nlmsg_type = NLMSG_ERROR;
676 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
677 			skb_trim(skb, nlh->nlmsg_len);
678 			e = nlmsg_data(nlh);
679 			e->error = -ETIMEDOUT;
680 			memset(&e->msg, 0, sizeof(e->msg));
681 
682 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
683 		} else {
684 			kfree_skb(skb);
685 		}
686 	}
687 
688 	ipmr_cache_free(c);
689 }
690 
691 /* Timer process for the unresolved queue. */
692 static void ipmr_expire_process(unsigned long arg)
693 {
694 	struct mr_table *mrt = (struct mr_table *)arg;
695 	unsigned long now;
696 	unsigned long expires;
697 	struct mfc_cache *c, *next;
698 
699 	if (!spin_trylock(&mfc_unres_lock)) {
700 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
701 		return;
702 	}
703 
704 	if (list_empty(&mrt->mfc_unres_queue))
705 		goto out;
706 
707 	now = jiffies;
708 	expires = 10*HZ;
709 
710 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
711 		if (time_after(c->mfc_un.unres.expires, now)) {
712 			unsigned long interval = c->mfc_un.unres.expires - now;
713 			if (interval < expires)
714 				expires = interval;
715 			continue;
716 		}
717 
718 		list_del(&c->list);
719 		mroute_netlink_event(mrt, c, RTM_DELROUTE);
720 		ipmr_destroy_unres(mrt, c);
721 	}
722 
723 	if (!list_empty(&mrt->mfc_unres_queue))
724 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
725 
726 out:
727 	spin_unlock(&mfc_unres_lock);
728 }
729 
730 /* Fill oifs list. It is called under write locked mrt_lock. */
731 static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
732 				   unsigned char *ttls)
733 {
734 	int vifi;
735 
736 	cache->mfc_un.res.minvif = MAXVIFS;
737 	cache->mfc_un.res.maxvif = 0;
738 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
739 
740 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
741 		if (VIF_EXISTS(mrt, vifi) &&
742 		    ttls[vifi] && ttls[vifi] < 255) {
743 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
744 			if (cache->mfc_un.res.minvif > vifi)
745 				cache->mfc_un.res.minvif = vifi;
746 			if (cache->mfc_un.res.maxvif <= vifi)
747 				cache->mfc_un.res.maxvif = vifi + 1;
748 		}
749 	}
750 	cache->mfc_un.res.lastuse = jiffies;
751 }
752 
753 static int vif_add(struct net *net, struct mr_table *mrt,
754 		   struct vifctl *vifc, int mrtsock)
755 {
756 	int vifi = vifc->vifc_vifi;
757 	struct vif_device *v = &mrt->vif_table[vifi];
758 	struct net_device *dev;
759 	struct in_device *in_dev;
760 	int err;
761 
762 	/* Is vif busy ? */
763 	if (VIF_EXISTS(mrt, vifi))
764 		return -EADDRINUSE;
765 
766 	switch (vifc->vifc_flags) {
767 	case VIFF_REGISTER:
768 		if (!ipmr_pimsm_enabled())
769 			return -EINVAL;
770 		/* Special Purpose VIF in PIM
771 		 * All the packets will be sent to the daemon
772 		 */
773 		if (mrt->mroute_reg_vif_num >= 0)
774 			return -EADDRINUSE;
775 		dev = ipmr_reg_vif(net, mrt);
776 		if (!dev)
777 			return -ENOBUFS;
778 		err = dev_set_allmulti(dev, 1);
779 		if (err) {
780 			unregister_netdevice(dev);
781 			dev_put(dev);
782 			return err;
783 		}
784 		break;
785 	case VIFF_TUNNEL:
786 		dev = ipmr_new_tunnel(net, vifc);
787 		if (!dev)
788 			return -ENOBUFS;
789 		err = dev_set_allmulti(dev, 1);
790 		if (err) {
791 			ipmr_del_tunnel(dev, vifc);
792 			dev_put(dev);
793 			return err;
794 		}
795 		break;
796 	case VIFF_USE_IFINDEX:
797 	case 0:
798 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
799 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
800 			if (dev && !__in_dev_get_rtnl(dev)) {
801 				dev_put(dev);
802 				return -EADDRNOTAVAIL;
803 			}
804 		} else {
805 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
806 		}
807 		if (!dev)
808 			return -EADDRNOTAVAIL;
809 		err = dev_set_allmulti(dev, 1);
810 		if (err) {
811 			dev_put(dev);
812 			return err;
813 		}
814 		break;
815 	default:
816 		return -EINVAL;
817 	}
818 
819 	in_dev = __in_dev_get_rtnl(dev);
820 	if (!in_dev) {
821 		dev_put(dev);
822 		return -EADDRNOTAVAIL;
823 	}
824 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
825 	inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING,
826 				    dev->ifindex, &in_dev->cnf);
827 	ip_rt_multicast_event(in_dev);
828 
829 	/* Fill in the VIF structures */
830 
831 	v->rate_limit = vifc->vifc_rate_limit;
832 	v->local = vifc->vifc_lcl_addr.s_addr;
833 	v->remote = vifc->vifc_rmt_addr.s_addr;
834 	v->flags = vifc->vifc_flags;
835 	if (!mrtsock)
836 		v->flags |= VIFF_STATIC;
837 	v->threshold = vifc->vifc_threshold;
838 	v->bytes_in = 0;
839 	v->bytes_out = 0;
840 	v->pkt_in = 0;
841 	v->pkt_out = 0;
842 	v->link = dev->ifindex;
843 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
844 		v->link = dev_get_iflink(dev);
845 
846 	/* And finish update writing critical data */
847 	write_lock_bh(&mrt_lock);
848 	v->dev = dev;
849 	if (v->flags & VIFF_REGISTER)
850 		mrt->mroute_reg_vif_num = vifi;
851 	if (vifi+1 > mrt->maxvif)
852 		mrt->maxvif = vifi+1;
853 	write_unlock_bh(&mrt_lock);
854 	return 0;
855 }
856 
857 /* called with rcu_read_lock() */
858 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
859 					 __be32 origin,
860 					 __be32 mcastgrp)
861 {
862 	struct mfc_cache_cmp_arg arg = {
863 			.mfc_mcastgrp = mcastgrp,
864 			.mfc_origin = origin
865 	};
866 	struct rhlist_head *tmp, *list;
867 	struct mfc_cache *c;
868 
869 	list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
870 	rhl_for_each_entry_rcu(c, tmp, list, mnode)
871 		return c;
872 
873 	return NULL;
874 }
875 
876 /* Look for a (*,*,oif) entry */
877 static struct mfc_cache *ipmr_cache_find_any_parent(struct mr_table *mrt,
878 						    int vifi)
879 {
880 	struct mfc_cache_cmp_arg arg = {
881 			.mfc_mcastgrp = htonl(INADDR_ANY),
882 			.mfc_origin = htonl(INADDR_ANY)
883 	};
884 	struct rhlist_head *tmp, *list;
885 	struct mfc_cache *c;
886 
887 	list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
888 	rhl_for_each_entry_rcu(c, tmp, list, mnode)
889 		if (c->mfc_un.res.ttls[vifi] < 255)
890 			return c;
891 
892 	return NULL;
893 }
894 
895 /* Look for a (*,G) entry */
896 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
897 					     __be32 mcastgrp, int vifi)
898 {
899 	struct mfc_cache_cmp_arg arg = {
900 			.mfc_mcastgrp = mcastgrp,
901 			.mfc_origin = htonl(INADDR_ANY)
902 	};
903 	struct rhlist_head *tmp, *list;
904 	struct mfc_cache *c, *proxy;
905 
906 	if (mcastgrp == htonl(INADDR_ANY))
907 		goto skip;
908 
909 	list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
910 	rhl_for_each_entry_rcu(c, tmp, list, mnode) {
911 		if (c->mfc_un.res.ttls[vifi] < 255)
912 			return c;
913 
914 		/* It's ok if the vifi is part of the static tree */
915 		proxy = ipmr_cache_find_any_parent(mrt, c->mfc_parent);
916 		if (proxy && proxy->mfc_un.res.ttls[vifi] < 255)
917 			return c;
918 	}
919 
920 skip:
921 	return ipmr_cache_find_any_parent(mrt, vifi);
922 }
923 
924 /* Look for a (S,G,iif) entry if parent != -1 */
925 static struct mfc_cache *ipmr_cache_find_parent(struct mr_table *mrt,
926 						__be32 origin, __be32 mcastgrp,
927 						int parent)
928 {
929 	struct mfc_cache_cmp_arg arg = {
930 			.mfc_mcastgrp = mcastgrp,
931 			.mfc_origin = origin,
932 	};
933 	struct rhlist_head *tmp, *list;
934 	struct mfc_cache *c;
935 
936 	list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
937 	rhl_for_each_entry_rcu(c, tmp, list, mnode)
938 		if (parent == -1 || parent == c->mfc_parent)
939 			return c;
940 
941 	return NULL;
942 }
943 
944 /* Allocate a multicast cache entry */
945 static struct mfc_cache *ipmr_cache_alloc(void)
946 {
947 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
948 
949 	if (c) {
950 		c->mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
951 		c->mfc_un.res.minvif = MAXVIFS;
952 	}
953 	return c;
954 }
955 
956 static struct mfc_cache *ipmr_cache_alloc_unres(void)
957 {
958 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
959 
960 	if (c) {
961 		skb_queue_head_init(&c->mfc_un.unres.unresolved);
962 		c->mfc_un.unres.expires = jiffies + 10*HZ;
963 	}
964 	return c;
965 }
966 
967 /* A cache entry has gone into a resolved state from queued */
968 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
969 			       struct mfc_cache *uc, struct mfc_cache *c)
970 {
971 	struct sk_buff *skb;
972 	struct nlmsgerr *e;
973 
974 	/* Play the pending entries through our router */
975 	while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
976 		if (ip_hdr(skb)->version == 0) {
977 			struct nlmsghdr *nlh = skb_pull(skb,
978 							sizeof(struct iphdr));
979 
980 			if (__ipmr_fill_mroute(mrt, skb, c, nlmsg_data(nlh)) > 0) {
981 				nlh->nlmsg_len = skb_tail_pointer(skb) -
982 						 (u8 *)nlh;
983 			} else {
984 				nlh->nlmsg_type = NLMSG_ERROR;
985 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
986 				skb_trim(skb, nlh->nlmsg_len);
987 				e = nlmsg_data(nlh);
988 				e->error = -EMSGSIZE;
989 				memset(&e->msg, 0, sizeof(e->msg));
990 			}
991 
992 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
993 		} else {
994 			ip_mr_forward(net, mrt, skb->dev, skb, c, 0);
995 		}
996 	}
997 }
998 
999 /* Bounce a cache query up to mrouted and netlink.
1000  *
1001  * Called under mrt_lock.
1002  */
1003 static int ipmr_cache_report(struct mr_table *mrt,
1004 			     struct sk_buff *pkt, vifi_t vifi, int assert)
1005 {
1006 	const int ihl = ip_hdrlen(pkt);
1007 	struct sock *mroute_sk;
1008 	struct igmphdr *igmp;
1009 	struct igmpmsg *msg;
1010 	struct sk_buff *skb;
1011 	int ret;
1012 
1013 	if (assert == IGMPMSG_WHOLEPKT)
1014 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
1015 	else
1016 		skb = alloc_skb(128, GFP_ATOMIC);
1017 
1018 	if (!skb)
1019 		return -ENOBUFS;
1020 
1021 	if (assert == IGMPMSG_WHOLEPKT) {
1022 		/* Ugly, but we have no choice with this interface.
1023 		 * Duplicate old header, fix ihl, length etc.
1024 		 * And all this only to mangle msg->im_msgtype and
1025 		 * to set msg->im_mbz to "mbz" :-)
1026 		 */
1027 		skb_push(skb, sizeof(struct iphdr));
1028 		skb_reset_network_header(skb);
1029 		skb_reset_transport_header(skb);
1030 		msg = (struct igmpmsg *)skb_network_header(skb);
1031 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
1032 		msg->im_msgtype = IGMPMSG_WHOLEPKT;
1033 		msg->im_mbz = 0;
1034 		msg->im_vif = mrt->mroute_reg_vif_num;
1035 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
1036 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
1037 					     sizeof(struct iphdr));
1038 	} else {
1039 		/* Copy the IP header */
1040 		skb_set_network_header(skb, skb->len);
1041 		skb_put(skb, ihl);
1042 		skb_copy_to_linear_data(skb, pkt->data, ihl);
1043 		/* Flag to the kernel this is a route add */
1044 		ip_hdr(skb)->protocol = 0;
1045 		msg = (struct igmpmsg *)skb_network_header(skb);
1046 		msg->im_vif = vifi;
1047 		skb_dst_set(skb, dst_clone(skb_dst(pkt)));
1048 		/* Add our header */
1049 		igmp = skb_put(skb, sizeof(struct igmphdr));
1050 		igmp->type = assert;
1051 		msg->im_msgtype = assert;
1052 		igmp->code = 0;
1053 		ip_hdr(skb)->tot_len = htons(skb->len);	/* Fix the length */
1054 		skb->transport_header = skb->network_header;
1055 	}
1056 
1057 	rcu_read_lock();
1058 	mroute_sk = rcu_dereference(mrt->mroute_sk);
1059 	if (!mroute_sk) {
1060 		rcu_read_unlock();
1061 		kfree_skb(skb);
1062 		return -EINVAL;
1063 	}
1064 
1065 	igmpmsg_netlink_event(mrt, skb);
1066 
1067 	/* Deliver to mrouted */
1068 	ret = sock_queue_rcv_skb(mroute_sk, skb);
1069 	rcu_read_unlock();
1070 	if (ret < 0) {
1071 		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1072 		kfree_skb(skb);
1073 	}
1074 
1075 	return ret;
1076 }
1077 
1078 /* Queue a packet for resolution. It gets locked cache entry! */
1079 static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
1080 				 struct sk_buff *skb, struct net_device *dev)
1081 {
1082 	const struct iphdr *iph = ip_hdr(skb);
1083 	struct mfc_cache *c;
1084 	bool found = false;
1085 	int err;
1086 
1087 	spin_lock_bh(&mfc_unres_lock);
1088 	list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
1089 		if (c->mfc_mcastgrp == iph->daddr &&
1090 		    c->mfc_origin == iph->saddr) {
1091 			found = true;
1092 			break;
1093 		}
1094 	}
1095 
1096 	if (!found) {
1097 		/* Create a new entry if allowable */
1098 		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
1099 		    (c = ipmr_cache_alloc_unres()) == NULL) {
1100 			spin_unlock_bh(&mfc_unres_lock);
1101 
1102 			kfree_skb(skb);
1103 			return -ENOBUFS;
1104 		}
1105 
1106 		/* Fill in the new cache entry */
1107 		c->mfc_parent	= -1;
1108 		c->mfc_origin	= iph->saddr;
1109 		c->mfc_mcastgrp	= iph->daddr;
1110 
1111 		/* Reflect first query at mrouted. */
1112 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1113 		if (err < 0) {
1114 			/* If the report failed throw the cache entry
1115 			   out - Brad Parker
1116 			 */
1117 			spin_unlock_bh(&mfc_unres_lock);
1118 
1119 			ipmr_cache_free(c);
1120 			kfree_skb(skb);
1121 			return err;
1122 		}
1123 
1124 		atomic_inc(&mrt->cache_resolve_queue_len);
1125 		list_add(&c->list, &mrt->mfc_unres_queue);
1126 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1127 
1128 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1129 			mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1130 	}
1131 
1132 	/* See if we can append the packet */
1133 	if (c->mfc_un.unres.unresolved.qlen > 3) {
1134 		kfree_skb(skb);
1135 		err = -ENOBUFS;
1136 	} else {
1137 		if (dev) {
1138 			skb->dev = dev;
1139 			skb->skb_iif = dev->ifindex;
1140 		}
1141 		skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1142 		err = 0;
1143 	}
1144 
1145 	spin_unlock_bh(&mfc_unres_lock);
1146 	return err;
1147 }
1148 
1149 /* MFC cache manipulation by user space mroute daemon */
1150 
1151 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1152 {
1153 	struct mfc_cache *c;
1154 
1155 	/* The entries are added/deleted only under RTNL */
1156 	rcu_read_lock();
1157 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1158 				   mfc->mfcc_mcastgrp.s_addr, parent);
1159 	rcu_read_unlock();
1160 	if (!c)
1161 		return -ENOENT;
1162 	rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
1163 	list_del_rcu(&c->list);
1164 	mroute_netlink_event(mrt, c, RTM_DELROUTE);
1165 	ipmr_cache_free(c);
1166 
1167 	return 0;
1168 }
1169 
1170 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1171 			struct mfcctl *mfc, int mrtsock, int parent)
1172 {
1173 	struct mfc_cache *uc, *c;
1174 	bool found;
1175 	int ret;
1176 
1177 	if (mfc->mfcc_parent >= MAXVIFS)
1178 		return -ENFILE;
1179 
1180 	/* The entries are added/deleted only under RTNL */
1181 	rcu_read_lock();
1182 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1183 				   mfc->mfcc_mcastgrp.s_addr, parent);
1184 	rcu_read_unlock();
1185 	if (c) {
1186 		write_lock_bh(&mrt_lock);
1187 		c->mfc_parent = mfc->mfcc_parent;
1188 		ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1189 		if (!mrtsock)
1190 			c->mfc_flags |= MFC_STATIC;
1191 		write_unlock_bh(&mrt_lock);
1192 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1193 		return 0;
1194 	}
1195 
1196 	if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1197 	    !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1198 		return -EINVAL;
1199 
1200 	c = ipmr_cache_alloc();
1201 	if (!c)
1202 		return -ENOMEM;
1203 
1204 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1205 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1206 	c->mfc_parent = mfc->mfcc_parent;
1207 	ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1208 	if (!mrtsock)
1209 		c->mfc_flags |= MFC_STATIC;
1210 
1211 	ret = rhltable_insert_key(&mrt->mfc_hash, &c->cmparg, &c->mnode,
1212 				  ipmr_rht_params);
1213 	if (ret) {
1214 		pr_err("ipmr: rhtable insert error %d\n", ret);
1215 		ipmr_cache_free(c);
1216 		return ret;
1217 	}
1218 	list_add_tail_rcu(&c->list, &mrt->mfc_cache_list);
1219 	/* Check to see if we resolved a queued list. If so we
1220 	 * need to send on the frames and tidy up.
1221 	 */
1222 	found = false;
1223 	spin_lock_bh(&mfc_unres_lock);
1224 	list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1225 		if (uc->mfc_origin == c->mfc_origin &&
1226 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1227 			list_del(&uc->list);
1228 			atomic_dec(&mrt->cache_resolve_queue_len);
1229 			found = true;
1230 			break;
1231 		}
1232 	}
1233 	if (list_empty(&mrt->mfc_unres_queue))
1234 		del_timer(&mrt->ipmr_expire_timer);
1235 	spin_unlock_bh(&mfc_unres_lock);
1236 
1237 	if (found) {
1238 		ipmr_cache_resolve(net, mrt, uc, c);
1239 		ipmr_cache_free(uc);
1240 	}
1241 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1242 	return 0;
1243 }
1244 
1245 /* Close the multicast socket, and clear the vif tables etc */
1246 static void mroute_clean_tables(struct mr_table *mrt, bool all)
1247 {
1248 	struct mfc_cache *c, *tmp;
1249 	LIST_HEAD(list);
1250 	int i;
1251 
1252 	/* Shut down all active vif entries */
1253 	for (i = 0; i < mrt->maxvif; i++) {
1254 		if (!all && (mrt->vif_table[i].flags & VIFF_STATIC))
1255 			continue;
1256 		vif_delete(mrt, i, 0, &list);
1257 	}
1258 	unregister_netdevice_many(&list);
1259 
1260 	/* Wipe the cache */
1261 	list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
1262 		if (!all && (c->mfc_flags & MFC_STATIC))
1263 			continue;
1264 		rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
1265 		list_del_rcu(&c->list);
1266 		mroute_netlink_event(mrt, c, RTM_DELROUTE);
1267 		ipmr_cache_free(c);
1268 	}
1269 
1270 	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1271 		spin_lock_bh(&mfc_unres_lock);
1272 		list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
1273 			list_del(&c->list);
1274 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1275 			ipmr_destroy_unres(mrt, c);
1276 		}
1277 		spin_unlock_bh(&mfc_unres_lock);
1278 	}
1279 }
1280 
1281 /* called from ip_ra_control(), before an RCU grace period,
1282  * we dont need to call synchronize_rcu() here
1283  */
1284 static void mrtsock_destruct(struct sock *sk)
1285 {
1286 	struct net *net = sock_net(sk);
1287 	struct mr_table *mrt;
1288 
1289 	ASSERT_RTNL();
1290 	ipmr_for_each_table(mrt, net) {
1291 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1292 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1293 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1294 						    NETCONFA_MC_FORWARDING,
1295 						    NETCONFA_IFINDEX_ALL,
1296 						    net->ipv4.devconf_all);
1297 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1298 			mroute_clean_tables(mrt, false);
1299 		}
1300 	}
1301 }
1302 
1303 /* Socket options and virtual interface manipulation. The whole
1304  * virtual interface system is a complete heap, but unfortunately
1305  * that's how BSD mrouted happens to think. Maybe one day with a proper
1306  * MOSPF/PIM router set up we can clean this up.
1307  */
1308 
1309 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
1310 			 unsigned int optlen)
1311 {
1312 	struct net *net = sock_net(sk);
1313 	int val, ret = 0, parent = 0;
1314 	struct mr_table *mrt;
1315 	struct vifctl vif;
1316 	struct mfcctl mfc;
1317 	u32 uval;
1318 
1319 	/* There's one exception to the lock - MRT_DONE which needs to unlock */
1320 	rtnl_lock();
1321 	if (sk->sk_type != SOCK_RAW ||
1322 	    inet_sk(sk)->inet_num != IPPROTO_IGMP) {
1323 		ret = -EOPNOTSUPP;
1324 		goto out_unlock;
1325 	}
1326 
1327 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1328 	if (!mrt) {
1329 		ret = -ENOENT;
1330 		goto out_unlock;
1331 	}
1332 	if (optname != MRT_INIT) {
1333 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1334 		    !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
1335 			ret = -EACCES;
1336 			goto out_unlock;
1337 		}
1338 	}
1339 
1340 	switch (optname) {
1341 	case MRT_INIT:
1342 		if (optlen != sizeof(int)) {
1343 			ret = -EINVAL;
1344 			break;
1345 		}
1346 		if (rtnl_dereference(mrt->mroute_sk)) {
1347 			ret = -EADDRINUSE;
1348 			break;
1349 		}
1350 
1351 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1352 		if (ret == 0) {
1353 			rcu_assign_pointer(mrt->mroute_sk, sk);
1354 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1355 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1356 						    NETCONFA_MC_FORWARDING,
1357 						    NETCONFA_IFINDEX_ALL,
1358 						    net->ipv4.devconf_all);
1359 		}
1360 		break;
1361 	case MRT_DONE:
1362 		if (sk != rcu_access_pointer(mrt->mroute_sk)) {
1363 			ret = -EACCES;
1364 		} else {
1365 			ret = ip_ra_control(sk, 0, NULL);
1366 			goto out_unlock;
1367 		}
1368 		break;
1369 	case MRT_ADD_VIF:
1370 	case MRT_DEL_VIF:
1371 		if (optlen != sizeof(vif)) {
1372 			ret = -EINVAL;
1373 			break;
1374 		}
1375 		if (copy_from_user(&vif, optval, sizeof(vif))) {
1376 			ret = -EFAULT;
1377 			break;
1378 		}
1379 		if (vif.vifc_vifi >= MAXVIFS) {
1380 			ret = -ENFILE;
1381 			break;
1382 		}
1383 		if (optname == MRT_ADD_VIF) {
1384 			ret = vif_add(net, mrt, &vif,
1385 				      sk == rtnl_dereference(mrt->mroute_sk));
1386 		} else {
1387 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1388 		}
1389 		break;
1390 	/* Manipulate the forwarding caches. These live
1391 	 * in a sort of kernel/user symbiosis.
1392 	 */
1393 	case MRT_ADD_MFC:
1394 	case MRT_DEL_MFC:
1395 		parent = -1;
1396 	case MRT_ADD_MFC_PROXY:
1397 	case MRT_DEL_MFC_PROXY:
1398 		if (optlen != sizeof(mfc)) {
1399 			ret = -EINVAL;
1400 			break;
1401 		}
1402 		if (copy_from_user(&mfc, optval, sizeof(mfc))) {
1403 			ret = -EFAULT;
1404 			break;
1405 		}
1406 		if (parent == 0)
1407 			parent = mfc.mfcc_parent;
1408 		if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1409 			ret = ipmr_mfc_delete(mrt, &mfc, parent);
1410 		else
1411 			ret = ipmr_mfc_add(net, mrt, &mfc,
1412 					   sk == rtnl_dereference(mrt->mroute_sk),
1413 					   parent);
1414 		break;
1415 	/* Control PIM assert. */
1416 	case MRT_ASSERT:
1417 		if (optlen != sizeof(val)) {
1418 			ret = -EINVAL;
1419 			break;
1420 		}
1421 		if (get_user(val, (int __user *)optval)) {
1422 			ret = -EFAULT;
1423 			break;
1424 		}
1425 		mrt->mroute_do_assert = val;
1426 		break;
1427 	case MRT_PIM:
1428 		if (!ipmr_pimsm_enabled()) {
1429 			ret = -ENOPROTOOPT;
1430 			break;
1431 		}
1432 		if (optlen != sizeof(val)) {
1433 			ret = -EINVAL;
1434 			break;
1435 		}
1436 		if (get_user(val, (int __user *)optval)) {
1437 			ret = -EFAULT;
1438 			break;
1439 		}
1440 
1441 		val = !!val;
1442 		if (val != mrt->mroute_do_pim) {
1443 			mrt->mroute_do_pim = val;
1444 			mrt->mroute_do_assert = val;
1445 		}
1446 		break;
1447 	case MRT_TABLE:
1448 		if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) {
1449 			ret = -ENOPROTOOPT;
1450 			break;
1451 		}
1452 		if (optlen != sizeof(uval)) {
1453 			ret = -EINVAL;
1454 			break;
1455 		}
1456 		if (get_user(uval, (u32 __user *)optval)) {
1457 			ret = -EFAULT;
1458 			break;
1459 		}
1460 
1461 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1462 			ret = -EBUSY;
1463 		} else {
1464 			mrt = ipmr_new_table(net, uval);
1465 			if (IS_ERR(mrt))
1466 				ret = PTR_ERR(mrt);
1467 			else
1468 				raw_sk(sk)->ipmr_table = uval;
1469 		}
1470 		break;
1471 	/* Spurious command, or MRT_VERSION which you cannot set. */
1472 	default:
1473 		ret = -ENOPROTOOPT;
1474 	}
1475 out_unlock:
1476 	rtnl_unlock();
1477 	return ret;
1478 }
1479 
1480 /* Getsock opt support for the multicast routing system. */
1481 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1482 {
1483 	int olr;
1484 	int val;
1485 	struct net *net = sock_net(sk);
1486 	struct mr_table *mrt;
1487 
1488 	if (sk->sk_type != SOCK_RAW ||
1489 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1490 		return -EOPNOTSUPP;
1491 
1492 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1493 	if (!mrt)
1494 		return -ENOENT;
1495 
1496 	switch (optname) {
1497 	case MRT_VERSION:
1498 		val = 0x0305;
1499 		break;
1500 	case MRT_PIM:
1501 		if (!ipmr_pimsm_enabled())
1502 			return -ENOPROTOOPT;
1503 		val = mrt->mroute_do_pim;
1504 		break;
1505 	case MRT_ASSERT:
1506 		val = mrt->mroute_do_assert;
1507 		break;
1508 	default:
1509 		return -ENOPROTOOPT;
1510 	}
1511 
1512 	if (get_user(olr, optlen))
1513 		return -EFAULT;
1514 	olr = min_t(unsigned int, olr, sizeof(int));
1515 	if (olr < 0)
1516 		return -EINVAL;
1517 	if (put_user(olr, optlen))
1518 		return -EFAULT;
1519 	if (copy_to_user(optval, &val, olr))
1520 		return -EFAULT;
1521 	return 0;
1522 }
1523 
1524 /* The IP multicast ioctl support routines. */
1525 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1526 {
1527 	struct sioc_sg_req sr;
1528 	struct sioc_vif_req vr;
1529 	struct vif_device *vif;
1530 	struct mfc_cache *c;
1531 	struct net *net = sock_net(sk);
1532 	struct mr_table *mrt;
1533 
1534 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1535 	if (!mrt)
1536 		return -ENOENT;
1537 
1538 	switch (cmd) {
1539 	case SIOCGETVIFCNT:
1540 		if (copy_from_user(&vr, arg, sizeof(vr)))
1541 			return -EFAULT;
1542 		if (vr.vifi >= mrt->maxvif)
1543 			return -EINVAL;
1544 		read_lock(&mrt_lock);
1545 		vif = &mrt->vif_table[vr.vifi];
1546 		if (VIF_EXISTS(mrt, vr.vifi)) {
1547 			vr.icount = vif->pkt_in;
1548 			vr.ocount = vif->pkt_out;
1549 			vr.ibytes = vif->bytes_in;
1550 			vr.obytes = vif->bytes_out;
1551 			read_unlock(&mrt_lock);
1552 
1553 			if (copy_to_user(arg, &vr, sizeof(vr)))
1554 				return -EFAULT;
1555 			return 0;
1556 		}
1557 		read_unlock(&mrt_lock);
1558 		return -EADDRNOTAVAIL;
1559 	case SIOCGETSGCNT:
1560 		if (copy_from_user(&sr, arg, sizeof(sr)))
1561 			return -EFAULT;
1562 
1563 		rcu_read_lock();
1564 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1565 		if (c) {
1566 			sr.pktcnt = c->mfc_un.res.pkt;
1567 			sr.bytecnt = c->mfc_un.res.bytes;
1568 			sr.wrong_if = c->mfc_un.res.wrong_if;
1569 			rcu_read_unlock();
1570 
1571 			if (copy_to_user(arg, &sr, sizeof(sr)))
1572 				return -EFAULT;
1573 			return 0;
1574 		}
1575 		rcu_read_unlock();
1576 		return -EADDRNOTAVAIL;
1577 	default:
1578 		return -ENOIOCTLCMD;
1579 	}
1580 }
1581 
1582 #ifdef CONFIG_COMPAT
1583 struct compat_sioc_sg_req {
1584 	struct in_addr src;
1585 	struct in_addr grp;
1586 	compat_ulong_t pktcnt;
1587 	compat_ulong_t bytecnt;
1588 	compat_ulong_t wrong_if;
1589 };
1590 
1591 struct compat_sioc_vif_req {
1592 	vifi_t	vifi;		/* Which iface */
1593 	compat_ulong_t icount;
1594 	compat_ulong_t ocount;
1595 	compat_ulong_t ibytes;
1596 	compat_ulong_t obytes;
1597 };
1598 
1599 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1600 {
1601 	struct compat_sioc_sg_req sr;
1602 	struct compat_sioc_vif_req vr;
1603 	struct vif_device *vif;
1604 	struct mfc_cache *c;
1605 	struct net *net = sock_net(sk);
1606 	struct mr_table *mrt;
1607 
1608 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1609 	if (!mrt)
1610 		return -ENOENT;
1611 
1612 	switch (cmd) {
1613 	case SIOCGETVIFCNT:
1614 		if (copy_from_user(&vr, arg, sizeof(vr)))
1615 			return -EFAULT;
1616 		if (vr.vifi >= mrt->maxvif)
1617 			return -EINVAL;
1618 		read_lock(&mrt_lock);
1619 		vif = &mrt->vif_table[vr.vifi];
1620 		if (VIF_EXISTS(mrt, vr.vifi)) {
1621 			vr.icount = vif->pkt_in;
1622 			vr.ocount = vif->pkt_out;
1623 			vr.ibytes = vif->bytes_in;
1624 			vr.obytes = vif->bytes_out;
1625 			read_unlock(&mrt_lock);
1626 
1627 			if (copy_to_user(arg, &vr, sizeof(vr)))
1628 				return -EFAULT;
1629 			return 0;
1630 		}
1631 		read_unlock(&mrt_lock);
1632 		return -EADDRNOTAVAIL;
1633 	case SIOCGETSGCNT:
1634 		if (copy_from_user(&sr, arg, sizeof(sr)))
1635 			return -EFAULT;
1636 
1637 		rcu_read_lock();
1638 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1639 		if (c) {
1640 			sr.pktcnt = c->mfc_un.res.pkt;
1641 			sr.bytecnt = c->mfc_un.res.bytes;
1642 			sr.wrong_if = c->mfc_un.res.wrong_if;
1643 			rcu_read_unlock();
1644 
1645 			if (copy_to_user(arg, &sr, sizeof(sr)))
1646 				return -EFAULT;
1647 			return 0;
1648 		}
1649 		rcu_read_unlock();
1650 		return -EADDRNOTAVAIL;
1651 	default:
1652 		return -ENOIOCTLCMD;
1653 	}
1654 }
1655 #endif
1656 
1657 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1658 {
1659 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1660 	struct net *net = dev_net(dev);
1661 	struct mr_table *mrt;
1662 	struct vif_device *v;
1663 	int ct;
1664 
1665 	if (event != NETDEV_UNREGISTER)
1666 		return NOTIFY_DONE;
1667 
1668 	ipmr_for_each_table(mrt, net) {
1669 		v = &mrt->vif_table[0];
1670 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1671 			if (v->dev == dev)
1672 				vif_delete(mrt, ct, 1, NULL);
1673 		}
1674 	}
1675 	return NOTIFY_DONE;
1676 }
1677 
1678 static struct notifier_block ip_mr_notifier = {
1679 	.notifier_call = ipmr_device_event,
1680 };
1681 
1682 /* Encapsulate a packet by attaching a valid IPIP header to it.
1683  * This avoids tunnel drivers and other mess and gives us the speed so
1684  * important for multicast video.
1685  */
1686 static void ip_encap(struct net *net, struct sk_buff *skb,
1687 		     __be32 saddr, __be32 daddr)
1688 {
1689 	struct iphdr *iph;
1690 	const struct iphdr *old_iph = ip_hdr(skb);
1691 
1692 	skb_push(skb, sizeof(struct iphdr));
1693 	skb->transport_header = skb->network_header;
1694 	skb_reset_network_header(skb);
1695 	iph = ip_hdr(skb);
1696 
1697 	iph->version	=	4;
1698 	iph->tos	=	old_iph->tos;
1699 	iph->ttl	=	old_iph->ttl;
1700 	iph->frag_off	=	0;
1701 	iph->daddr	=	daddr;
1702 	iph->saddr	=	saddr;
1703 	iph->protocol	=	IPPROTO_IPIP;
1704 	iph->ihl	=	5;
1705 	iph->tot_len	=	htons(skb->len);
1706 	ip_select_ident(net, skb, NULL);
1707 	ip_send_check(iph);
1708 
1709 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1710 	nf_reset(skb);
1711 }
1712 
1713 static inline int ipmr_forward_finish(struct net *net, struct sock *sk,
1714 				      struct sk_buff *skb)
1715 {
1716 	struct ip_options *opt = &(IPCB(skb)->opt);
1717 
1718 	IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
1719 	IP_ADD_STATS(net, IPSTATS_MIB_OUTOCTETS, skb->len);
1720 
1721 	if (unlikely(opt->optlen))
1722 		ip_forward_options(skb);
1723 
1724 	return dst_output(net, sk, skb);
1725 }
1726 
1727 /* Processing handlers for ipmr_forward */
1728 
1729 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1730 			    struct sk_buff *skb, struct mfc_cache *c, int vifi)
1731 {
1732 	const struct iphdr *iph = ip_hdr(skb);
1733 	struct vif_device *vif = &mrt->vif_table[vifi];
1734 	struct net_device *dev;
1735 	struct rtable *rt;
1736 	struct flowi4 fl4;
1737 	int    encap = 0;
1738 
1739 	if (!vif->dev)
1740 		goto out_free;
1741 
1742 	if (vif->flags & VIFF_REGISTER) {
1743 		vif->pkt_out++;
1744 		vif->bytes_out += skb->len;
1745 		vif->dev->stats.tx_bytes += skb->len;
1746 		vif->dev->stats.tx_packets++;
1747 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1748 		goto out_free;
1749 	}
1750 
1751 	if (vif->flags & VIFF_TUNNEL) {
1752 		rt = ip_route_output_ports(net, &fl4, NULL,
1753 					   vif->remote, vif->local,
1754 					   0, 0,
1755 					   IPPROTO_IPIP,
1756 					   RT_TOS(iph->tos), vif->link);
1757 		if (IS_ERR(rt))
1758 			goto out_free;
1759 		encap = sizeof(struct iphdr);
1760 	} else {
1761 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1762 					   0, 0,
1763 					   IPPROTO_IPIP,
1764 					   RT_TOS(iph->tos), vif->link);
1765 		if (IS_ERR(rt))
1766 			goto out_free;
1767 	}
1768 
1769 	dev = rt->dst.dev;
1770 
1771 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1772 		/* Do not fragment multicasts. Alas, IPv4 does not
1773 		 * allow to send ICMP, so that packets will disappear
1774 		 * to blackhole.
1775 		 */
1776 		IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
1777 		ip_rt_put(rt);
1778 		goto out_free;
1779 	}
1780 
1781 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1782 
1783 	if (skb_cow(skb, encap)) {
1784 		ip_rt_put(rt);
1785 		goto out_free;
1786 	}
1787 
1788 	vif->pkt_out++;
1789 	vif->bytes_out += skb->len;
1790 
1791 	skb_dst_drop(skb);
1792 	skb_dst_set(skb, &rt->dst);
1793 	ip_decrease_ttl(ip_hdr(skb));
1794 
1795 	/* FIXME: forward and output firewalls used to be called here.
1796 	 * What do we do with netfilter? -- RR
1797 	 */
1798 	if (vif->flags & VIFF_TUNNEL) {
1799 		ip_encap(net, skb, vif->local, vif->remote);
1800 		/* FIXME: extra output firewall step used to be here. --RR */
1801 		vif->dev->stats.tx_packets++;
1802 		vif->dev->stats.tx_bytes += skb->len;
1803 	}
1804 
1805 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1806 
1807 	/* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1808 	 * not only before forwarding, but after forwarding on all output
1809 	 * interfaces. It is clear, if mrouter runs a multicasting
1810 	 * program, it should receive packets not depending to what interface
1811 	 * program is joined.
1812 	 * If we will not make it, the program will have to join on all
1813 	 * interfaces. On the other hand, multihoming host (or router, but
1814 	 * not mrouter) cannot join to more than one interface - it will
1815 	 * result in receiving multiple packets.
1816 	 */
1817 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
1818 		net, NULL, skb, skb->dev, dev,
1819 		ipmr_forward_finish);
1820 	return;
1821 
1822 out_free:
1823 	kfree_skb(skb);
1824 }
1825 
1826 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1827 {
1828 	int ct;
1829 
1830 	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1831 		if (mrt->vif_table[ct].dev == dev)
1832 			break;
1833 	}
1834 	return ct;
1835 }
1836 
1837 /* "local" means that we should preserve one skb (for local delivery) */
1838 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
1839 			  struct net_device *dev, struct sk_buff *skb,
1840 			  struct mfc_cache *cache, int local)
1841 {
1842 	int true_vifi = ipmr_find_vif(mrt, dev);
1843 	int psend = -1;
1844 	int vif, ct;
1845 
1846 	vif = cache->mfc_parent;
1847 	cache->mfc_un.res.pkt++;
1848 	cache->mfc_un.res.bytes += skb->len;
1849 	cache->mfc_un.res.lastuse = jiffies;
1850 
1851 	if (cache->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
1852 		struct mfc_cache *cache_proxy;
1853 
1854 		/* For an (*,G) entry, we only check that the incomming
1855 		 * interface is part of the static tree.
1856 		 */
1857 		cache_proxy = ipmr_cache_find_any_parent(mrt, vif);
1858 		if (cache_proxy &&
1859 		    cache_proxy->mfc_un.res.ttls[true_vifi] < 255)
1860 			goto forward;
1861 	}
1862 
1863 	/* Wrong interface: drop packet and (maybe) send PIM assert. */
1864 	if (mrt->vif_table[vif].dev != dev) {
1865 		if (rt_is_output_route(skb_rtable(skb))) {
1866 			/* It is our own packet, looped back.
1867 			 * Very complicated situation...
1868 			 *
1869 			 * The best workaround until routing daemons will be
1870 			 * fixed is not to redistribute packet, if it was
1871 			 * send through wrong interface. It means, that
1872 			 * multicast applications WILL NOT work for
1873 			 * (S,G), which have default multicast route pointing
1874 			 * to wrong oif. In any case, it is not a good
1875 			 * idea to use multicasting applications on router.
1876 			 */
1877 			goto dont_forward;
1878 		}
1879 
1880 		cache->mfc_un.res.wrong_if++;
1881 
1882 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
1883 		    /* pimsm uses asserts, when switching from RPT to SPT,
1884 		     * so that we cannot check that packet arrived on an oif.
1885 		     * It is bad, but otherwise we would need to move pretty
1886 		     * large chunk of pimd to kernel. Ough... --ANK
1887 		     */
1888 		    (mrt->mroute_do_pim ||
1889 		     cache->mfc_un.res.ttls[true_vifi] < 255) &&
1890 		    time_after(jiffies,
1891 			       cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1892 			cache->mfc_un.res.last_assert = jiffies;
1893 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1894 		}
1895 		goto dont_forward;
1896 	}
1897 
1898 forward:
1899 	mrt->vif_table[vif].pkt_in++;
1900 	mrt->vif_table[vif].bytes_in += skb->len;
1901 
1902 	/* Forward the frame */
1903 	if (cache->mfc_origin == htonl(INADDR_ANY) &&
1904 	    cache->mfc_mcastgrp == htonl(INADDR_ANY)) {
1905 		if (true_vifi >= 0 &&
1906 		    true_vifi != cache->mfc_parent &&
1907 		    ip_hdr(skb)->ttl >
1908 				cache->mfc_un.res.ttls[cache->mfc_parent]) {
1909 			/* It's an (*,*) entry and the packet is not coming from
1910 			 * the upstream: forward the packet to the upstream
1911 			 * only.
1912 			 */
1913 			psend = cache->mfc_parent;
1914 			goto last_forward;
1915 		}
1916 		goto dont_forward;
1917 	}
1918 	for (ct = cache->mfc_un.res.maxvif - 1;
1919 	     ct >= cache->mfc_un.res.minvif; ct--) {
1920 		/* For (*,G) entry, don't forward to the incoming interface */
1921 		if ((cache->mfc_origin != htonl(INADDR_ANY) ||
1922 		     ct != true_vifi) &&
1923 		    ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1924 			if (psend != -1) {
1925 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1926 
1927 				if (skb2)
1928 					ipmr_queue_xmit(net, mrt, skb2, cache,
1929 							psend);
1930 			}
1931 			psend = ct;
1932 		}
1933 	}
1934 last_forward:
1935 	if (psend != -1) {
1936 		if (local) {
1937 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1938 
1939 			if (skb2)
1940 				ipmr_queue_xmit(net, mrt, skb2, cache, psend);
1941 		} else {
1942 			ipmr_queue_xmit(net, mrt, skb, cache, psend);
1943 			return;
1944 		}
1945 	}
1946 
1947 dont_forward:
1948 	if (!local)
1949 		kfree_skb(skb);
1950 }
1951 
1952 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
1953 {
1954 	struct rtable *rt = skb_rtable(skb);
1955 	struct iphdr *iph = ip_hdr(skb);
1956 	struct flowi4 fl4 = {
1957 		.daddr = iph->daddr,
1958 		.saddr = iph->saddr,
1959 		.flowi4_tos = RT_TOS(iph->tos),
1960 		.flowi4_oif = (rt_is_output_route(rt) ?
1961 			       skb->dev->ifindex : 0),
1962 		.flowi4_iif = (rt_is_output_route(rt) ?
1963 			       LOOPBACK_IFINDEX :
1964 			       skb->dev->ifindex),
1965 		.flowi4_mark = skb->mark,
1966 	};
1967 	struct mr_table *mrt;
1968 	int err;
1969 
1970 	err = ipmr_fib_lookup(net, &fl4, &mrt);
1971 	if (err)
1972 		return ERR_PTR(err);
1973 	return mrt;
1974 }
1975 
1976 /* Multicast packets for forwarding arrive here
1977  * Called with rcu_read_lock();
1978  */
1979 int ip_mr_input(struct sk_buff *skb)
1980 {
1981 	struct mfc_cache *cache;
1982 	struct net *net = dev_net(skb->dev);
1983 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
1984 	struct mr_table *mrt;
1985 	struct net_device *dev;
1986 
1987 	/* skb->dev passed in is the loX master dev for vrfs.
1988 	 * As there are no vifs associated with loopback devices,
1989 	 * get the proper interface that does have a vif associated with it.
1990 	 */
1991 	dev = skb->dev;
1992 	if (netif_is_l3_master(skb->dev)) {
1993 		dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
1994 		if (!dev) {
1995 			kfree_skb(skb);
1996 			return -ENODEV;
1997 		}
1998 	}
1999 
2000 	/* Packet is looped back after forward, it should not be
2001 	 * forwarded second time, but still can be delivered locally.
2002 	 */
2003 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
2004 		goto dont_forward;
2005 
2006 	mrt = ipmr_rt_fib_lookup(net, skb);
2007 	if (IS_ERR(mrt)) {
2008 		kfree_skb(skb);
2009 		return PTR_ERR(mrt);
2010 	}
2011 	if (!local) {
2012 		if (IPCB(skb)->opt.router_alert) {
2013 			if (ip_call_ra_chain(skb))
2014 				return 0;
2015 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
2016 			/* IGMPv1 (and broken IGMPv2 implementations sort of
2017 			 * Cisco IOS <= 11.2(8)) do not put router alert
2018 			 * option to IGMP packets destined to routable
2019 			 * groups. It is very bad, because it means
2020 			 * that we can forward NO IGMP messages.
2021 			 */
2022 			struct sock *mroute_sk;
2023 
2024 			mroute_sk = rcu_dereference(mrt->mroute_sk);
2025 			if (mroute_sk) {
2026 				nf_reset(skb);
2027 				raw_rcv(mroute_sk, skb);
2028 				return 0;
2029 			}
2030 		    }
2031 	}
2032 
2033 	/* already under rcu_read_lock() */
2034 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
2035 	if (!cache) {
2036 		int vif = ipmr_find_vif(mrt, dev);
2037 
2038 		if (vif >= 0)
2039 			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
2040 						    vif);
2041 	}
2042 
2043 	/* No usable cache entry */
2044 	if (!cache) {
2045 		int vif;
2046 
2047 		if (local) {
2048 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2049 			ip_local_deliver(skb);
2050 			if (!skb2)
2051 				return -ENOBUFS;
2052 			skb = skb2;
2053 		}
2054 
2055 		read_lock(&mrt_lock);
2056 		vif = ipmr_find_vif(mrt, dev);
2057 		if (vif >= 0) {
2058 			int err2 = ipmr_cache_unresolved(mrt, vif, skb, dev);
2059 			read_unlock(&mrt_lock);
2060 
2061 			return err2;
2062 		}
2063 		read_unlock(&mrt_lock);
2064 		kfree_skb(skb);
2065 		return -ENODEV;
2066 	}
2067 
2068 	read_lock(&mrt_lock);
2069 	ip_mr_forward(net, mrt, dev, skb, cache, local);
2070 	read_unlock(&mrt_lock);
2071 
2072 	if (local)
2073 		return ip_local_deliver(skb);
2074 
2075 	return 0;
2076 
2077 dont_forward:
2078 	if (local)
2079 		return ip_local_deliver(skb);
2080 	kfree_skb(skb);
2081 	return 0;
2082 }
2083 
2084 #ifdef CONFIG_IP_PIMSM_V1
2085 /* Handle IGMP messages of PIMv1 */
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_TYPE_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 	struct rta_mfc_stats mfcs;
2144 	struct nlattr *mp_attr;
2145 	struct rtnexthop *nhp;
2146 	unsigned long lastuse;
2147 	int ct;
2148 
2149 	/* If cache is unresolved, don't try to parse IIF and OIF */
2150 	if (c->mfc_parent >= MAXVIFS) {
2151 		rtm->rtm_flags |= RTNH_F_UNRESOLVED;
2152 		return -ENOENT;
2153 	}
2154 
2155 	if (VIF_EXISTS(mrt, c->mfc_parent) &&
2156 	    nla_put_u32(skb, RTA_IIF, mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
2157 		return -EMSGSIZE;
2158 
2159 	if (!(mp_attr = nla_nest_start(skb, RTA_MULTIPATH)))
2160 		return -EMSGSIZE;
2161 
2162 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
2163 		if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
2164 			if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp)))) {
2165 				nla_nest_cancel(skb, mp_attr);
2166 				return -EMSGSIZE;
2167 			}
2168 
2169 			nhp->rtnh_flags = 0;
2170 			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
2171 			nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
2172 			nhp->rtnh_len = sizeof(*nhp);
2173 		}
2174 	}
2175 
2176 	nla_nest_end(skb, mp_attr);
2177 
2178 	lastuse = READ_ONCE(c->mfc_un.res.lastuse);
2179 	lastuse = time_after_eq(jiffies, lastuse) ? jiffies - lastuse : 0;
2180 
2181 	mfcs.mfcs_packets = c->mfc_un.res.pkt;
2182 	mfcs.mfcs_bytes = c->mfc_un.res.bytes;
2183 	mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
2184 	if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) ||
2185 	    nla_put_u64_64bit(skb, RTA_EXPIRES, jiffies_to_clock_t(lastuse),
2186 			      RTA_PAD))
2187 		return -EMSGSIZE;
2188 
2189 	rtm->rtm_type = RTN_MULTICAST;
2190 	return 1;
2191 }
2192 
2193 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2194 		   __be32 saddr, __be32 daddr,
2195 		   struct rtmsg *rtm, u32 portid)
2196 {
2197 	struct mfc_cache *cache;
2198 	struct mr_table *mrt;
2199 	int err;
2200 
2201 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2202 	if (!mrt)
2203 		return -ENOENT;
2204 
2205 	rcu_read_lock();
2206 	cache = ipmr_cache_find(mrt, saddr, daddr);
2207 	if (!cache && skb->dev) {
2208 		int vif = ipmr_find_vif(mrt, skb->dev);
2209 
2210 		if (vif >= 0)
2211 			cache = ipmr_cache_find_any(mrt, daddr, vif);
2212 	}
2213 	if (!cache) {
2214 		struct sk_buff *skb2;
2215 		struct iphdr *iph;
2216 		struct net_device *dev;
2217 		int vif = -1;
2218 
2219 		dev = skb->dev;
2220 		read_lock(&mrt_lock);
2221 		if (dev)
2222 			vif = ipmr_find_vif(mrt, dev);
2223 		if (vif < 0) {
2224 			read_unlock(&mrt_lock);
2225 			rcu_read_unlock();
2226 			return -ENODEV;
2227 		}
2228 		skb2 = skb_clone(skb, GFP_ATOMIC);
2229 		if (!skb2) {
2230 			read_unlock(&mrt_lock);
2231 			rcu_read_unlock();
2232 			return -ENOMEM;
2233 		}
2234 
2235 		NETLINK_CB(skb2).portid = portid;
2236 		skb_push(skb2, sizeof(struct iphdr));
2237 		skb_reset_network_header(skb2);
2238 		iph = ip_hdr(skb2);
2239 		iph->ihl = sizeof(struct iphdr) >> 2;
2240 		iph->saddr = saddr;
2241 		iph->daddr = daddr;
2242 		iph->version = 0;
2243 		err = ipmr_cache_unresolved(mrt, vif, skb2, dev);
2244 		read_unlock(&mrt_lock);
2245 		rcu_read_unlock();
2246 		return err;
2247 	}
2248 
2249 	read_lock(&mrt_lock);
2250 	err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2251 	read_unlock(&mrt_lock);
2252 	rcu_read_unlock();
2253 	return err;
2254 }
2255 
2256 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2257 			    u32 portid, u32 seq, struct mfc_cache *c, int cmd,
2258 			    int flags)
2259 {
2260 	struct nlmsghdr *nlh;
2261 	struct rtmsg *rtm;
2262 	int err;
2263 
2264 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2265 	if (!nlh)
2266 		return -EMSGSIZE;
2267 
2268 	rtm = nlmsg_data(nlh);
2269 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2270 	rtm->rtm_dst_len  = 32;
2271 	rtm->rtm_src_len  = 32;
2272 	rtm->rtm_tos      = 0;
2273 	rtm->rtm_table    = mrt->id;
2274 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2275 		goto nla_put_failure;
2276 	rtm->rtm_type     = RTN_MULTICAST;
2277 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2278 	if (c->mfc_flags & MFC_STATIC)
2279 		rtm->rtm_protocol = RTPROT_STATIC;
2280 	else
2281 		rtm->rtm_protocol = RTPROT_MROUTED;
2282 	rtm->rtm_flags    = 0;
2283 
2284 	if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
2285 	    nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
2286 		goto nla_put_failure;
2287 	err = __ipmr_fill_mroute(mrt, skb, c, rtm);
2288 	/* do not break the dump if cache is unresolved */
2289 	if (err < 0 && err != -ENOENT)
2290 		goto nla_put_failure;
2291 
2292 	nlmsg_end(skb, nlh);
2293 	return 0;
2294 
2295 nla_put_failure:
2296 	nlmsg_cancel(skb, nlh);
2297 	return -EMSGSIZE;
2298 }
2299 
2300 static size_t mroute_msgsize(bool unresolved, int maxvif)
2301 {
2302 	size_t len =
2303 		NLMSG_ALIGN(sizeof(struct rtmsg))
2304 		+ nla_total_size(4)	/* RTA_TABLE */
2305 		+ nla_total_size(4)	/* RTA_SRC */
2306 		+ nla_total_size(4)	/* RTA_DST */
2307 		;
2308 
2309 	if (!unresolved)
2310 		len = len
2311 		      + nla_total_size(4)	/* RTA_IIF */
2312 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2313 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2314 						/* RTA_MFC_STATS */
2315 		      + nla_total_size_64bit(sizeof(struct rta_mfc_stats))
2316 		;
2317 
2318 	return len;
2319 }
2320 
2321 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2322 				 int cmd)
2323 {
2324 	struct net *net = read_pnet(&mrt->net);
2325 	struct sk_buff *skb;
2326 	int err = -ENOBUFS;
2327 
2328 	skb = nlmsg_new(mroute_msgsize(mfc->mfc_parent >= MAXVIFS, mrt->maxvif),
2329 			GFP_ATOMIC);
2330 	if (!skb)
2331 		goto errout;
2332 
2333 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2334 	if (err < 0)
2335 		goto errout;
2336 
2337 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2338 	return;
2339 
2340 errout:
2341 	kfree_skb(skb);
2342 	if (err < 0)
2343 		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2344 }
2345 
2346 static size_t igmpmsg_netlink_msgsize(size_t payloadlen)
2347 {
2348 	size_t len =
2349 		NLMSG_ALIGN(sizeof(struct rtgenmsg))
2350 		+ nla_total_size(1)	/* IPMRA_CREPORT_MSGTYPE */
2351 		+ nla_total_size(4)	/* IPMRA_CREPORT_VIF_ID */
2352 		+ nla_total_size(4)	/* IPMRA_CREPORT_SRC_ADDR */
2353 		+ nla_total_size(4)	/* IPMRA_CREPORT_DST_ADDR */
2354 					/* IPMRA_CREPORT_PKT */
2355 		+ nla_total_size(payloadlen)
2356 		;
2357 
2358 	return len;
2359 }
2360 
2361 static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt)
2362 {
2363 	struct net *net = read_pnet(&mrt->net);
2364 	struct nlmsghdr *nlh;
2365 	struct rtgenmsg *rtgenm;
2366 	struct igmpmsg *msg;
2367 	struct sk_buff *skb;
2368 	struct nlattr *nla;
2369 	int payloadlen;
2370 
2371 	payloadlen = pkt->len - sizeof(struct igmpmsg);
2372 	msg = (struct igmpmsg *)skb_network_header(pkt);
2373 
2374 	skb = nlmsg_new(igmpmsg_netlink_msgsize(payloadlen), GFP_ATOMIC);
2375 	if (!skb)
2376 		goto errout;
2377 
2378 	nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT,
2379 			sizeof(struct rtgenmsg), 0);
2380 	if (!nlh)
2381 		goto errout;
2382 	rtgenm = nlmsg_data(nlh);
2383 	rtgenm->rtgen_family = RTNL_FAMILY_IPMR;
2384 	if (nla_put_u8(skb, IPMRA_CREPORT_MSGTYPE, msg->im_msgtype) ||
2385 	    nla_put_u32(skb, IPMRA_CREPORT_VIF_ID, msg->im_vif) ||
2386 	    nla_put_in_addr(skb, IPMRA_CREPORT_SRC_ADDR,
2387 			    msg->im_src.s_addr) ||
2388 	    nla_put_in_addr(skb, IPMRA_CREPORT_DST_ADDR,
2389 			    msg->im_dst.s_addr))
2390 		goto nla_put_failure;
2391 
2392 	nla = nla_reserve(skb, IPMRA_CREPORT_PKT, payloadlen);
2393 	if (!nla || skb_copy_bits(pkt, sizeof(struct igmpmsg),
2394 				  nla_data(nla), payloadlen))
2395 		goto nla_put_failure;
2396 
2397 	nlmsg_end(skb, nlh);
2398 
2399 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE_R, NULL, GFP_ATOMIC);
2400 	return;
2401 
2402 nla_put_failure:
2403 	nlmsg_cancel(skb, nlh);
2404 errout:
2405 	kfree_skb(skb);
2406 	rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE_R, -ENOBUFS);
2407 }
2408 
2409 static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2410 			     struct netlink_ext_ack *extack)
2411 {
2412 	struct net *net = sock_net(in_skb->sk);
2413 	struct nlattr *tb[RTA_MAX + 1];
2414 	struct sk_buff *skb = NULL;
2415 	struct mfc_cache *cache;
2416 	struct mr_table *mrt;
2417 	struct rtmsg *rtm;
2418 	__be32 src, grp;
2419 	u32 tableid;
2420 	int err;
2421 
2422 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX,
2423 			  rtm_ipv4_policy, extack);
2424 	if (err < 0)
2425 		goto errout;
2426 
2427 	rtm = nlmsg_data(nlh);
2428 
2429 	src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2430 	grp = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2431 	tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0;
2432 
2433 	mrt = ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT);
2434 	if (!mrt) {
2435 		err = -ENOENT;
2436 		goto errout_free;
2437 	}
2438 
2439 	/* entries are added/deleted only under RTNL */
2440 	rcu_read_lock();
2441 	cache = ipmr_cache_find(mrt, src, grp);
2442 	rcu_read_unlock();
2443 	if (!cache) {
2444 		err = -ENOENT;
2445 		goto errout_free;
2446 	}
2447 
2448 	skb = nlmsg_new(mroute_msgsize(false, mrt->maxvif), GFP_KERNEL);
2449 	if (!skb) {
2450 		err = -ENOBUFS;
2451 		goto errout_free;
2452 	}
2453 
2454 	err = ipmr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid,
2455 			       nlh->nlmsg_seq, cache,
2456 			       RTM_NEWROUTE, 0);
2457 	if (err < 0)
2458 		goto errout_free;
2459 
2460 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2461 
2462 errout:
2463 	return err;
2464 
2465 errout_free:
2466 	kfree_skb(skb);
2467 	goto errout;
2468 }
2469 
2470 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2471 {
2472 	struct net *net = sock_net(skb->sk);
2473 	struct mr_table *mrt;
2474 	struct mfc_cache *mfc;
2475 	unsigned int t = 0, s_t;
2476 	unsigned int e = 0, s_e;
2477 
2478 	s_t = cb->args[0];
2479 	s_e = cb->args[1];
2480 
2481 	rcu_read_lock();
2482 	ipmr_for_each_table(mrt, net) {
2483 		if (t < s_t)
2484 			goto next_table;
2485 		list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) {
2486 			if (e < s_e)
2487 				goto next_entry;
2488 			if (ipmr_fill_mroute(mrt, skb,
2489 					     NETLINK_CB(cb->skb).portid,
2490 					     cb->nlh->nlmsg_seq,
2491 					     mfc, RTM_NEWROUTE,
2492 					     NLM_F_MULTI) < 0)
2493 				goto done;
2494 next_entry:
2495 			e++;
2496 		}
2497 		e = 0;
2498 		s_e = 0;
2499 
2500 		spin_lock_bh(&mfc_unres_lock);
2501 		list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
2502 			if (e < s_e)
2503 				goto next_entry2;
2504 			if (ipmr_fill_mroute(mrt, skb,
2505 					     NETLINK_CB(cb->skb).portid,
2506 					     cb->nlh->nlmsg_seq,
2507 					     mfc, RTM_NEWROUTE,
2508 					     NLM_F_MULTI) < 0) {
2509 				spin_unlock_bh(&mfc_unres_lock);
2510 				goto done;
2511 			}
2512 next_entry2:
2513 			e++;
2514 		}
2515 		spin_unlock_bh(&mfc_unres_lock);
2516 		e = 0;
2517 		s_e = 0;
2518 next_table:
2519 		t++;
2520 	}
2521 done:
2522 	rcu_read_unlock();
2523 
2524 	cb->args[1] = e;
2525 	cb->args[0] = t;
2526 
2527 	return skb->len;
2528 }
2529 
2530 static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {
2531 	[RTA_SRC]	= { .type = NLA_U32 },
2532 	[RTA_DST]	= { .type = NLA_U32 },
2533 	[RTA_IIF]	= { .type = NLA_U32 },
2534 	[RTA_TABLE]	= { .type = NLA_U32 },
2535 	[RTA_MULTIPATH]	= { .len = sizeof(struct rtnexthop) },
2536 };
2537 
2538 static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol)
2539 {
2540 	switch (rtm_protocol) {
2541 	case RTPROT_STATIC:
2542 	case RTPROT_MROUTED:
2543 		return true;
2544 	}
2545 	return false;
2546 }
2547 
2548 static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc)
2549 {
2550 	struct rtnexthop *rtnh = nla_data(nla);
2551 	int remaining = nla_len(nla), vifi = 0;
2552 
2553 	while (rtnh_ok(rtnh, remaining)) {
2554 		mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops;
2555 		if (++vifi == MAXVIFS)
2556 			break;
2557 		rtnh = rtnh_next(rtnh, &remaining);
2558 	}
2559 
2560 	return remaining > 0 ? -EINVAL : vifi;
2561 }
2562 
2563 /* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */
2564 static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
2565 			    struct mfcctl *mfcc, int *mrtsock,
2566 			    struct mr_table **mrtret,
2567 			    struct netlink_ext_ack *extack)
2568 {
2569 	struct net_device *dev = NULL;
2570 	u32 tblid = RT_TABLE_DEFAULT;
2571 	struct mr_table *mrt;
2572 	struct nlattr *attr;
2573 	struct rtmsg *rtm;
2574 	int ret, rem;
2575 
2576 	ret = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipmr_policy,
2577 			     extack);
2578 	if (ret < 0)
2579 		goto out;
2580 	rtm = nlmsg_data(nlh);
2581 
2582 	ret = -EINVAL;
2583 	if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 ||
2584 	    rtm->rtm_type != RTN_MULTICAST ||
2585 	    rtm->rtm_scope != RT_SCOPE_UNIVERSE ||
2586 	    !ipmr_rtm_validate_proto(rtm->rtm_protocol))
2587 		goto out;
2588 
2589 	memset(mfcc, 0, sizeof(*mfcc));
2590 	mfcc->mfcc_parent = -1;
2591 	ret = 0;
2592 	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) {
2593 		switch (nla_type(attr)) {
2594 		case RTA_SRC:
2595 			mfcc->mfcc_origin.s_addr = nla_get_be32(attr);
2596 			break;
2597 		case RTA_DST:
2598 			mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr);
2599 			break;
2600 		case RTA_IIF:
2601 			dev = __dev_get_by_index(net, nla_get_u32(attr));
2602 			if (!dev) {
2603 				ret = -ENODEV;
2604 				goto out;
2605 			}
2606 			break;
2607 		case RTA_MULTIPATH:
2608 			if (ipmr_nla_get_ttls(attr, mfcc) < 0) {
2609 				ret = -EINVAL;
2610 				goto out;
2611 			}
2612 			break;
2613 		case RTA_PREFSRC:
2614 			ret = 1;
2615 			break;
2616 		case RTA_TABLE:
2617 			tblid = nla_get_u32(attr);
2618 			break;
2619 		}
2620 	}
2621 	mrt = ipmr_get_table(net, tblid);
2622 	if (!mrt) {
2623 		ret = -ENOENT;
2624 		goto out;
2625 	}
2626 	*mrtret = mrt;
2627 	*mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0;
2628 	if (dev)
2629 		mfcc->mfcc_parent = ipmr_find_vif(mrt, dev);
2630 
2631 out:
2632 	return ret;
2633 }
2634 
2635 /* takes care of both newroute and delroute */
2636 static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh,
2637 			  struct netlink_ext_ack *extack)
2638 {
2639 	struct net *net = sock_net(skb->sk);
2640 	int ret, mrtsock, parent;
2641 	struct mr_table *tbl;
2642 	struct mfcctl mfcc;
2643 
2644 	mrtsock = 0;
2645 	tbl = NULL;
2646 	ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl, extack);
2647 	if (ret < 0)
2648 		return ret;
2649 
2650 	parent = ret ? mfcc.mfcc_parent : -1;
2651 	if (nlh->nlmsg_type == RTM_NEWROUTE)
2652 		return ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent);
2653 	else
2654 		return ipmr_mfc_delete(tbl, &mfcc, parent);
2655 }
2656 
2657 static bool ipmr_fill_table(struct mr_table *mrt, struct sk_buff *skb)
2658 {
2659 	u32 queue_len = atomic_read(&mrt->cache_resolve_queue_len);
2660 
2661 	if (nla_put_u32(skb, IPMRA_TABLE_ID, mrt->id) ||
2662 	    nla_put_u32(skb, IPMRA_TABLE_CACHE_RES_QUEUE_LEN, queue_len) ||
2663 	    nla_put_s32(skb, IPMRA_TABLE_MROUTE_REG_VIF_NUM,
2664 			mrt->mroute_reg_vif_num) ||
2665 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_ASSERT,
2666 		       mrt->mroute_do_assert) ||
2667 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_PIM, mrt->mroute_do_pim))
2668 		return false;
2669 
2670 	return true;
2671 }
2672 
2673 static bool ipmr_fill_vif(struct mr_table *mrt, u32 vifid, struct sk_buff *skb)
2674 {
2675 	struct nlattr *vif_nest;
2676 	struct vif_device *vif;
2677 
2678 	/* if the VIF doesn't exist just continue */
2679 	if (!VIF_EXISTS(mrt, vifid))
2680 		return true;
2681 
2682 	vif = &mrt->vif_table[vifid];
2683 	vif_nest = nla_nest_start(skb, IPMRA_VIF);
2684 	if (!vif_nest)
2685 		return false;
2686 	if (nla_put_u32(skb, IPMRA_VIFA_IFINDEX, vif->dev->ifindex) ||
2687 	    nla_put_u32(skb, IPMRA_VIFA_VIF_ID, vifid) ||
2688 	    nla_put_u16(skb, IPMRA_VIFA_FLAGS, vif->flags) ||
2689 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_IN, vif->bytes_in,
2690 			      IPMRA_VIFA_PAD) ||
2691 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_OUT, vif->bytes_out,
2692 			      IPMRA_VIFA_PAD) ||
2693 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_IN, vif->pkt_in,
2694 			      IPMRA_VIFA_PAD) ||
2695 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_OUT, vif->pkt_out,
2696 			      IPMRA_VIFA_PAD) ||
2697 	    nla_put_be32(skb, IPMRA_VIFA_LOCAL_ADDR, vif->local) ||
2698 	    nla_put_be32(skb, IPMRA_VIFA_REMOTE_ADDR, vif->remote)) {
2699 		nla_nest_cancel(skb, vif_nest);
2700 		return false;
2701 	}
2702 	nla_nest_end(skb, vif_nest);
2703 
2704 	return true;
2705 }
2706 
2707 static int ipmr_rtm_dumplink(struct sk_buff *skb, struct netlink_callback *cb)
2708 {
2709 	struct net *net = sock_net(skb->sk);
2710 	struct nlmsghdr *nlh = NULL;
2711 	unsigned int t = 0, s_t;
2712 	unsigned int e = 0, s_e;
2713 	struct mr_table *mrt;
2714 
2715 	s_t = cb->args[0];
2716 	s_e = cb->args[1];
2717 
2718 	ipmr_for_each_table(mrt, net) {
2719 		struct nlattr *vifs, *af;
2720 		struct ifinfomsg *hdr;
2721 		u32 i;
2722 
2723 		if (t < s_t)
2724 			goto skip_table;
2725 		nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
2726 				cb->nlh->nlmsg_seq, RTM_NEWLINK,
2727 				sizeof(*hdr), NLM_F_MULTI);
2728 		if (!nlh)
2729 			break;
2730 
2731 		hdr = nlmsg_data(nlh);
2732 		memset(hdr, 0, sizeof(*hdr));
2733 		hdr->ifi_family = RTNL_FAMILY_IPMR;
2734 
2735 		af = nla_nest_start(skb, IFLA_AF_SPEC);
2736 		if (!af) {
2737 			nlmsg_cancel(skb, nlh);
2738 			goto out;
2739 		}
2740 
2741 		if (!ipmr_fill_table(mrt, skb)) {
2742 			nlmsg_cancel(skb, nlh);
2743 			goto out;
2744 		}
2745 
2746 		vifs = nla_nest_start(skb, IPMRA_TABLE_VIFS);
2747 		if (!vifs) {
2748 			nla_nest_end(skb, af);
2749 			nlmsg_end(skb, nlh);
2750 			goto out;
2751 		}
2752 		for (i = 0; i < mrt->maxvif; i++) {
2753 			if (e < s_e)
2754 				goto skip_entry;
2755 			if (!ipmr_fill_vif(mrt, i, skb)) {
2756 				nla_nest_end(skb, vifs);
2757 				nla_nest_end(skb, af);
2758 				nlmsg_end(skb, nlh);
2759 				goto out;
2760 			}
2761 skip_entry:
2762 			e++;
2763 		}
2764 		s_e = 0;
2765 		e = 0;
2766 		nla_nest_end(skb, vifs);
2767 		nla_nest_end(skb, af);
2768 		nlmsg_end(skb, nlh);
2769 skip_table:
2770 		t++;
2771 	}
2772 
2773 out:
2774 	cb->args[1] = e;
2775 	cb->args[0] = t;
2776 
2777 	return skb->len;
2778 }
2779 
2780 #ifdef CONFIG_PROC_FS
2781 /* The /proc interfaces to multicast routing :
2782  * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2783  */
2784 struct ipmr_vif_iter {
2785 	struct seq_net_private p;
2786 	struct mr_table *mrt;
2787 	int ct;
2788 };
2789 
2790 static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2791 					   struct ipmr_vif_iter *iter,
2792 					   loff_t pos)
2793 {
2794 	struct mr_table *mrt = iter->mrt;
2795 
2796 	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2797 		if (!VIF_EXISTS(mrt, iter->ct))
2798 			continue;
2799 		if (pos-- == 0)
2800 			return &mrt->vif_table[iter->ct];
2801 	}
2802 	return NULL;
2803 }
2804 
2805 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2806 	__acquires(mrt_lock)
2807 {
2808 	struct ipmr_vif_iter *iter = seq->private;
2809 	struct net *net = seq_file_net(seq);
2810 	struct mr_table *mrt;
2811 
2812 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2813 	if (!mrt)
2814 		return ERR_PTR(-ENOENT);
2815 
2816 	iter->mrt = mrt;
2817 
2818 	read_lock(&mrt_lock);
2819 	return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2820 		: SEQ_START_TOKEN;
2821 }
2822 
2823 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2824 {
2825 	struct ipmr_vif_iter *iter = seq->private;
2826 	struct net *net = seq_file_net(seq);
2827 	struct mr_table *mrt = iter->mrt;
2828 
2829 	++*pos;
2830 	if (v == SEQ_START_TOKEN)
2831 		return ipmr_vif_seq_idx(net, iter, 0);
2832 
2833 	while (++iter->ct < mrt->maxvif) {
2834 		if (!VIF_EXISTS(mrt, iter->ct))
2835 			continue;
2836 		return &mrt->vif_table[iter->ct];
2837 	}
2838 	return NULL;
2839 }
2840 
2841 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2842 	__releases(mrt_lock)
2843 {
2844 	read_unlock(&mrt_lock);
2845 }
2846 
2847 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2848 {
2849 	struct ipmr_vif_iter *iter = seq->private;
2850 	struct mr_table *mrt = iter->mrt;
2851 
2852 	if (v == SEQ_START_TOKEN) {
2853 		seq_puts(seq,
2854 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2855 	} else {
2856 		const struct vif_device *vif = v;
2857 		const char *name =  vif->dev ? vif->dev->name : "none";
2858 
2859 		seq_printf(seq,
2860 			   "%2zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2861 			   vif - mrt->vif_table,
2862 			   name, vif->bytes_in, vif->pkt_in,
2863 			   vif->bytes_out, vif->pkt_out,
2864 			   vif->flags, vif->local, vif->remote);
2865 	}
2866 	return 0;
2867 }
2868 
2869 static const struct seq_operations ipmr_vif_seq_ops = {
2870 	.start = ipmr_vif_seq_start,
2871 	.next  = ipmr_vif_seq_next,
2872 	.stop  = ipmr_vif_seq_stop,
2873 	.show  = ipmr_vif_seq_show,
2874 };
2875 
2876 static int ipmr_vif_open(struct inode *inode, struct file *file)
2877 {
2878 	return seq_open_net(inode, file, &ipmr_vif_seq_ops,
2879 			    sizeof(struct ipmr_vif_iter));
2880 }
2881 
2882 static const struct file_operations ipmr_vif_fops = {
2883 	.owner	 = THIS_MODULE,
2884 	.open    = ipmr_vif_open,
2885 	.read    = seq_read,
2886 	.llseek  = seq_lseek,
2887 	.release = seq_release_net,
2888 };
2889 
2890 struct ipmr_mfc_iter {
2891 	struct seq_net_private p;
2892 	struct mr_table *mrt;
2893 	struct list_head *cache;
2894 };
2895 
2896 static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
2897 					  struct ipmr_mfc_iter *it, loff_t pos)
2898 {
2899 	struct mr_table *mrt = it->mrt;
2900 	struct mfc_cache *mfc;
2901 
2902 	rcu_read_lock();
2903 	it->cache = &mrt->mfc_cache_list;
2904 	list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list)
2905 		if (pos-- == 0)
2906 			return mfc;
2907 	rcu_read_unlock();
2908 
2909 	spin_lock_bh(&mfc_unres_lock);
2910 	it->cache = &mrt->mfc_unres_queue;
2911 	list_for_each_entry(mfc, it->cache, list)
2912 		if (pos-- == 0)
2913 			return mfc;
2914 	spin_unlock_bh(&mfc_unres_lock);
2915 
2916 	it->cache = NULL;
2917 	return NULL;
2918 }
2919 
2920 
2921 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2922 {
2923 	struct ipmr_mfc_iter *it = seq->private;
2924 	struct net *net = seq_file_net(seq);
2925 	struct mr_table *mrt;
2926 
2927 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2928 	if (!mrt)
2929 		return ERR_PTR(-ENOENT);
2930 
2931 	it->mrt = mrt;
2932 	it->cache = NULL;
2933 	return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
2934 		: SEQ_START_TOKEN;
2935 }
2936 
2937 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2938 {
2939 	struct ipmr_mfc_iter *it = seq->private;
2940 	struct net *net = seq_file_net(seq);
2941 	struct mr_table *mrt = it->mrt;
2942 	struct mfc_cache *mfc = v;
2943 
2944 	++*pos;
2945 
2946 	if (v == SEQ_START_TOKEN)
2947 		return ipmr_mfc_seq_idx(net, seq->private, 0);
2948 
2949 	if (mfc->list.next != it->cache)
2950 		return list_entry(mfc->list.next, struct mfc_cache, list);
2951 
2952 	if (it->cache == &mrt->mfc_unres_queue)
2953 		goto end_of_list;
2954 
2955 	/* exhausted cache_array, show unresolved */
2956 	rcu_read_unlock();
2957 	it->cache = &mrt->mfc_unres_queue;
2958 
2959 	spin_lock_bh(&mfc_unres_lock);
2960 	if (!list_empty(it->cache))
2961 		return list_first_entry(it->cache, struct mfc_cache, list);
2962 
2963 end_of_list:
2964 	spin_unlock_bh(&mfc_unres_lock);
2965 	it->cache = NULL;
2966 
2967 	return NULL;
2968 }
2969 
2970 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
2971 {
2972 	struct ipmr_mfc_iter *it = seq->private;
2973 	struct mr_table *mrt = it->mrt;
2974 
2975 	if (it->cache == &mrt->mfc_unres_queue)
2976 		spin_unlock_bh(&mfc_unres_lock);
2977 	else if (it->cache == &mrt->mfc_cache_list)
2978 		rcu_read_unlock();
2979 }
2980 
2981 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2982 {
2983 	int n;
2984 
2985 	if (v == SEQ_START_TOKEN) {
2986 		seq_puts(seq,
2987 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2988 	} else {
2989 		const struct mfc_cache *mfc = v;
2990 		const struct ipmr_mfc_iter *it = seq->private;
2991 		const struct mr_table *mrt = it->mrt;
2992 
2993 		seq_printf(seq, "%08X %08X %-3hd",
2994 			   (__force u32) mfc->mfc_mcastgrp,
2995 			   (__force u32) mfc->mfc_origin,
2996 			   mfc->mfc_parent);
2997 
2998 		if (it->cache != &mrt->mfc_unres_queue) {
2999 			seq_printf(seq, " %8lu %8lu %8lu",
3000 				   mfc->mfc_un.res.pkt,
3001 				   mfc->mfc_un.res.bytes,
3002 				   mfc->mfc_un.res.wrong_if);
3003 			for (n = mfc->mfc_un.res.minvif;
3004 			     n < mfc->mfc_un.res.maxvif; n++) {
3005 				if (VIF_EXISTS(mrt, n) &&
3006 				    mfc->mfc_un.res.ttls[n] < 255)
3007 					seq_printf(seq,
3008 					   " %2d:%-3d",
3009 					   n, mfc->mfc_un.res.ttls[n]);
3010 			}
3011 		} else {
3012 			/* unresolved mfc_caches don't contain
3013 			 * pkt, bytes and wrong_if values
3014 			 */
3015 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
3016 		}
3017 		seq_putc(seq, '\n');
3018 	}
3019 	return 0;
3020 }
3021 
3022 static const struct seq_operations ipmr_mfc_seq_ops = {
3023 	.start = ipmr_mfc_seq_start,
3024 	.next  = ipmr_mfc_seq_next,
3025 	.stop  = ipmr_mfc_seq_stop,
3026 	.show  = ipmr_mfc_seq_show,
3027 };
3028 
3029 static int ipmr_mfc_open(struct inode *inode, struct file *file)
3030 {
3031 	return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
3032 			    sizeof(struct ipmr_mfc_iter));
3033 }
3034 
3035 static const struct file_operations ipmr_mfc_fops = {
3036 	.owner	 = THIS_MODULE,
3037 	.open    = ipmr_mfc_open,
3038 	.read    = seq_read,
3039 	.llseek  = seq_lseek,
3040 	.release = seq_release_net,
3041 };
3042 #endif
3043 
3044 #ifdef CONFIG_IP_PIMSM_V2
3045 static const struct net_protocol pim_protocol = {
3046 	.handler	=	pim_rcv,
3047 	.netns_ok	=	1,
3048 };
3049 #endif
3050 
3051 /* Setup for IP multicast routing */
3052 static int __net_init ipmr_net_init(struct net *net)
3053 {
3054 	int err;
3055 
3056 	err = ipmr_rules_init(net);
3057 	if (err < 0)
3058 		goto fail;
3059 
3060 #ifdef CONFIG_PROC_FS
3061 	err = -ENOMEM;
3062 	if (!proc_create("ip_mr_vif", 0, net->proc_net, &ipmr_vif_fops))
3063 		goto proc_vif_fail;
3064 	if (!proc_create("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_fops))
3065 		goto proc_cache_fail;
3066 #endif
3067 	return 0;
3068 
3069 #ifdef CONFIG_PROC_FS
3070 proc_cache_fail:
3071 	remove_proc_entry("ip_mr_vif", net->proc_net);
3072 proc_vif_fail:
3073 	ipmr_rules_exit(net);
3074 #endif
3075 fail:
3076 	return err;
3077 }
3078 
3079 static void __net_exit ipmr_net_exit(struct net *net)
3080 {
3081 #ifdef CONFIG_PROC_FS
3082 	remove_proc_entry("ip_mr_cache", net->proc_net);
3083 	remove_proc_entry("ip_mr_vif", net->proc_net);
3084 #endif
3085 	ipmr_rules_exit(net);
3086 }
3087 
3088 static struct pernet_operations ipmr_net_ops = {
3089 	.init = ipmr_net_init,
3090 	.exit = ipmr_net_exit,
3091 };
3092 
3093 int __init ip_mr_init(void)
3094 {
3095 	int err;
3096 
3097 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
3098 				       sizeof(struct mfc_cache),
3099 				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
3100 				       NULL);
3101 
3102 	err = register_pernet_subsys(&ipmr_net_ops);
3103 	if (err)
3104 		goto reg_pernet_fail;
3105 
3106 	err = register_netdevice_notifier(&ip_mr_notifier);
3107 	if (err)
3108 		goto reg_notif_fail;
3109 #ifdef CONFIG_IP_PIMSM_V2
3110 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
3111 		pr_err("%s: can't add PIM protocol\n", __func__);
3112 		err = -EAGAIN;
3113 		goto add_proto_fail;
3114 	}
3115 #endif
3116 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
3117 		      ipmr_rtm_getroute, ipmr_rtm_dumproute, 0);
3118 	rtnl_register(RTNL_FAMILY_IPMR, RTM_NEWROUTE,
3119 		      ipmr_rtm_route, NULL, 0);
3120 	rtnl_register(RTNL_FAMILY_IPMR, RTM_DELROUTE,
3121 		      ipmr_rtm_route, NULL, 0);
3122 
3123 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETLINK,
3124 		      NULL, ipmr_rtm_dumplink, 0);
3125 	return 0;
3126 
3127 #ifdef CONFIG_IP_PIMSM_V2
3128 add_proto_fail:
3129 	unregister_netdevice_notifier(&ip_mr_notifier);
3130 #endif
3131 reg_notif_fail:
3132 	unregister_pernet_subsys(&ipmr_net_ops);
3133 reg_pernet_fail:
3134 	kmem_cache_destroy(mrt_cachep);
3135 	return err;
3136 }
3137