xref: /openbmc/linux/net/ipv4/ipmr.c (revision 2eb3ed33e55d003d721d4d1a5e72fe323c12b4c0)
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 #include <net/switchdev.h>
71 
72 struct ipmr_rule {
73 	struct fib_rule		common;
74 };
75 
76 struct ipmr_result {
77 	struct mr_table		*mrt;
78 };
79 
80 /* Big lock, protecting vif table, mrt cache and mroute socket state.
81  * Note that the changes are semaphored via rtnl_lock.
82  */
83 
84 static DEFINE_RWLOCK(mrt_lock);
85 
86 /* Multicast router control variables */
87 
88 /* Special spinlock for queue of unresolved entries */
89 static DEFINE_SPINLOCK(mfc_unres_lock);
90 
91 /* We return to original Alan's scheme. Hash table of resolved
92  * entries is changed only in process context and protected
93  * with weak lock mrt_lock. Queue of unresolved entries is protected
94  * with strong spinlock mfc_unres_lock.
95  *
96  * In this case data path is free of exclusive locks at all.
97  */
98 
99 static struct kmem_cache *mrt_cachep __read_mostly;
100 
101 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
102 static void ipmr_free_table(struct mr_table *mrt);
103 
104 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
105 			  struct net_device *dev, struct sk_buff *skb,
106 			  struct mfc_cache *cache, int local);
107 static int ipmr_cache_report(struct mr_table *mrt,
108 			     struct sk_buff *pkt, vifi_t vifi, int assert);
109 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
110 			      struct mfc_cache *c, struct rtmsg *rtm);
111 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
112 				 int cmd);
113 static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
114 static void mroute_clean_tables(struct mr_table *mrt, bool all);
115 static void ipmr_expire_process(unsigned long arg);
116 
117 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
118 #define ipmr_for_each_table(mrt, net) \
119 	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
120 
121 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
122 {
123 	struct mr_table *mrt;
124 
125 	ipmr_for_each_table(mrt, net) {
126 		if (mrt->id == id)
127 			return mrt;
128 	}
129 	return NULL;
130 }
131 
132 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
133 			   struct mr_table **mrt)
134 {
135 	int err;
136 	struct ipmr_result res;
137 	struct fib_lookup_arg arg = {
138 		.result = &res,
139 		.flags = FIB_LOOKUP_NOREF,
140 	};
141 
142 	/* update flow if oif or iif point to device enslaved to l3mdev */
143 	l3mdev_update_flow(net, flowi4_to_flowi(flp4));
144 
145 	err = fib_rules_lookup(net->ipv4.mr_rules_ops,
146 			       flowi4_to_flowi(flp4), 0, &arg);
147 	if (err < 0)
148 		return err;
149 	*mrt = res.mrt;
150 	return 0;
151 }
152 
153 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
154 			    int flags, struct fib_lookup_arg *arg)
155 {
156 	struct ipmr_result *res = arg->result;
157 	struct mr_table *mrt;
158 
159 	switch (rule->action) {
160 	case FR_ACT_TO_TBL:
161 		break;
162 	case FR_ACT_UNREACHABLE:
163 		return -ENETUNREACH;
164 	case FR_ACT_PROHIBIT:
165 		return -EACCES;
166 	case FR_ACT_BLACKHOLE:
167 	default:
168 		return -EINVAL;
169 	}
170 
171 	arg->table = fib_rule_get_table(rule, arg);
172 
173 	mrt = ipmr_get_table(rule->fr_net, arg->table);
174 	if (!mrt)
175 		return -EAGAIN;
176 	res->mrt = mrt;
177 	return 0;
178 }
179 
180 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
181 {
182 	return 1;
183 }
184 
185 static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
186 	FRA_GENERIC_POLICY,
187 };
188 
189 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
190 			       struct fib_rule_hdr *frh, struct nlattr **tb)
191 {
192 	return 0;
193 }
194 
195 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
196 			     struct nlattr **tb)
197 {
198 	return 1;
199 }
200 
201 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
202 			  struct fib_rule_hdr *frh)
203 {
204 	frh->dst_len = 0;
205 	frh->src_len = 0;
206 	frh->tos     = 0;
207 	return 0;
208 }
209 
210 static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
211 	.family		= RTNL_FAMILY_IPMR,
212 	.rule_size	= sizeof(struct ipmr_rule),
213 	.addr_size	= sizeof(u32),
214 	.action		= ipmr_rule_action,
215 	.match		= ipmr_rule_match,
216 	.configure	= ipmr_rule_configure,
217 	.compare	= ipmr_rule_compare,
218 	.fill		= ipmr_rule_fill,
219 	.nlgroup	= RTNLGRP_IPV4_RULE,
220 	.policy		= ipmr_rule_policy,
221 	.owner		= THIS_MODULE,
222 };
223 
224 static int __net_init ipmr_rules_init(struct net *net)
225 {
226 	struct fib_rules_ops *ops;
227 	struct mr_table *mrt;
228 	int err;
229 
230 	ops = fib_rules_register(&ipmr_rules_ops_template, net);
231 	if (IS_ERR(ops))
232 		return PTR_ERR(ops);
233 
234 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
235 
236 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
237 	if (IS_ERR(mrt)) {
238 		err = PTR_ERR(mrt);
239 		goto err1;
240 	}
241 
242 	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
243 	if (err < 0)
244 		goto err2;
245 
246 	net->ipv4.mr_rules_ops = ops;
247 	return 0;
248 
249 err2:
250 	ipmr_free_table(mrt);
251 err1:
252 	fib_rules_unregister(ops);
253 	return err;
254 }
255 
256 static void __net_exit ipmr_rules_exit(struct net *net)
257 {
258 	struct mr_table *mrt, *next;
259 
260 	rtnl_lock();
261 	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
262 		list_del(&mrt->list);
263 		ipmr_free_table(mrt);
264 	}
265 	fib_rules_unregister(net->ipv4.mr_rules_ops);
266 	rtnl_unlock();
267 }
268 
269 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb)
270 {
271 	return fib_rules_dump(net, nb, RTNL_FAMILY_IPMR);
272 }
273 
274 static unsigned int ipmr_rules_seq_read(struct net *net)
275 {
276 	return fib_rules_seq_read(net, RTNL_FAMILY_IPMR);
277 }
278 
279 bool ipmr_rule_default(const struct fib_rule *rule)
280 {
281 	return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
282 }
283 EXPORT_SYMBOL(ipmr_rule_default);
284 #else
285 #define ipmr_for_each_table(mrt, net) \
286 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
287 
288 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
289 {
290 	return net->ipv4.mrt;
291 }
292 
293 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
294 			   struct mr_table **mrt)
295 {
296 	*mrt = net->ipv4.mrt;
297 	return 0;
298 }
299 
300 static int __net_init ipmr_rules_init(struct net *net)
301 {
302 	struct mr_table *mrt;
303 
304 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
305 	if (IS_ERR(mrt))
306 		return PTR_ERR(mrt);
307 	net->ipv4.mrt = mrt;
308 	return 0;
309 }
310 
311 static void __net_exit ipmr_rules_exit(struct net *net)
312 {
313 	rtnl_lock();
314 	ipmr_free_table(net->ipv4.mrt);
315 	net->ipv4.mrt = NULL;
316 	rtnl_unlock();
317 }
318 
319 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb)
320 {
321 	return 0;
322 }
323 
324 static unsigned int ipmr_rules_seq_read(struct net *net)
325 {
326 	return 0;
327 }
328 
329 bool ipmr_rule_default(const struct fib_rule *rule)
330 {
331 	return true;
332 }
333 EXPORT_SYMBOL(ipmr_rule_default);
334 #endif
335 
336 static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
337 				const void *ptr)
338 {
339 	const struct mfc_cache_cmp_arg *cmparg = arg->key;
340 	struct mfc_cache *c = (struct mfc_cache *)ptr;
341 
342 	return cmparg->mfc_mcastgrp != c->mfc_mcastgrp ||
343 	       cmparg->mfc_origin != c->mfc_origin;
344 }
345 
346 static const struct rhashtable_params ipmr_rht_params = {
347 	.head_offset = offsetof(struct mfc_cache, mnode),
348 	.key_offset = offsetof(struct mfc_cache, cmparg),
349 	.key_len = sizeof(struct mfc_cache_cmp_arg),
350 	.nelem_hint = 3,
351 	.locks_mul = 1,
352 	.obj_cmpfn = ipmr_hash_cmp,
353 	.automatic_shrinking = true,
354 };
355 
356 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
357 {
358 	struct mr_table *mrt;
359 
360 	/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
361 	if (id != RT_TABLE_DEFAULT && id >= 1000000000)
362 		return ERR_PTR(-EINVAL);
363 
364 	mrt = ipmr_get_table(net, id);
365 	if (mrt)
366 		return mrt;
367 
368 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
369 	if (!mrt)
370 		return ERR_PTR(-ENOMEM);
371 	write_pnet(&mrt->net, net);
372 	mrt->id = id;
373 
374 	rhltable_init(&mrt->mfc_hash, &ipmr_rht_params);
375 	INIT_LIST_HEAD(&mrt->mfc_cache_list);
376 	INIT_LIST_HEAD(&mrt->mfc_unres_queue);
377 
378 	setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
379 		    (unsigned long)mrt);
380 
381 	mrt->mroute_reg_vif_num = -1;
382 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
383 	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
384 #endif
385 	return mrt;
386 }
387 
388 static void ipmr_free_table(struct mr_table *mrt)
389 {
390 	del_timer_sync(&mrt->ipmr_expire_timer);
391 	mroute_clean_tables(mrt, true);
392 	rhltable_destroy(&mrt->mfc_hash);
393 	kfree(mrt);
394 }
395 
396 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
397 
398 static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
399 {
400 	struct net *net = dev_net(dev);
401 
402 	dev_close(dev);
403 
404 	dev = __dev_get_by_name(net, "tunl0");
405 	if (dev) {
406 		const struct net_device_ops *ops = dev->netdev_ops;
407 		struct ifreq ifr;
408 		struct ip_tunnel_parm p;
409 
410 		memset(&p, 0, sizeof(p));
411 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
412 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
413 		p.iph.version = 4;
414 		p.iph.ihl = 5;
415 		p.iph.protocol = IPPROTO_IPIP;
416 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
417 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
418 
419 		if (ops->ndo_do_ioctl) {
420 			mm_segment_t oldfs = get_fs();
421 
422 			set_fs(KERNEL_DS);
423 			ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
424 			set_fs(oldfs);
425 		}
426 	}
427 }
428 
429 /* Initialize ipmr pimreg/tunnel in_device */
430 static bool ipmr_init_vif_indev(const struct net_device *dev)
431 {
432 	struct in_device *in_dev;
433 
434 	ASSERT_RTNL();
435 
436 	in_dev = __in_dev_get_rtnl(dev);
437 	if (!in_dev)
438 		return false;
439 	ipv4_devconf_setall(in_dev);
440 	neigh_parms_data_state_setall(in_dev->arp_parms);
441 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
442 
443 	return true;
444 }
445 
446 static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
447 {
448 	struct net_device  *dev;
449 
450 	dev = __dev_get_by_name(net, "tunl0");
451 
452 	if (dev) {
453 		const struct net_device_ops *ops = dev->netdev_ops;
454 		int err;
455 		struct ifreq ifr;
456 		struct ip_tunnel_parm p;
457 
458 		memset(&p, 0, sizeof(p));
459 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
460 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
461 		p.iph.version = 4;
462 		p.iph.ihl = 5;
463 		p.iph.protocol = IPPROTO_IPIP;
464 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
465 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
466 
467 		if (ops->ndo_do_ioctl) {
468 			mm_segment_t oldfs = get_fs();
469 
470 			set_fs(KERNEL_DS);
471 			err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
472 			set_fs(oldfs);
473 		} else {
474 			err = -EOPNOTSUPP;
475 		}
476 		dev = NULL;
477 
478 		if (err == 0 &&
479 		    (dev = __dev_get_by_name(net, p.name)) != NULL) {
480 			dev->flags |= IFF_MULTICAST;
481 			if (!ipmr_init_vif_indev(dev))
482 				goto failure;
483 			if (dev_open(dev))
484 				goto failure;
485 			dev_hold(dev);
486 		}
487 	}
488 	return dev;
489 
490 failure:
491 	unregister_netdevice(dev);
492 	return NULL;
493 }
494 
495 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
496 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
497 {
498 	struct net *net = dev_net(dev);
499 	struct mr_table *mrt;
500 	struct flowi4 fl4 = {
501 		.flowi4_oif	= dev->ifindex,
502 		.flowi4_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
503 		.flowi4_mark	= skb->mark,
504 	};
505 	int err;
506 
507 	err = ipmr_fib_lookup(net, &fl4, &mrt);
508 	if (err < 0) {
509 		kfree_skb(skb);
510 		return err;
511 	}
512 
513 	read_lock(&mrt_lock);
514 	dev->stats.tx_bytes += skb->len;
515 	dev->stats.tx_packets++;
516 	ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
517 	read_unlock(&mrt_lock);
518 	kfree_skb(skb);
519 	return NETDEV_TX_OK;
520 }
521 
522 static int reg_vif_get_iflink(const struct net_device *dev)
523 {
524 	return 0;
525 }
526 
527 static const struct net_device_ops reg_vif_netdev_ops = {
528 	.ndo_start_xmit	= reg_vif_xmit,
529 	.ndo_get_iflink = reg_vif_get_iflink,
530 };
531 
532 static void reg_vif_setup(struct net_device *dev)
533 {
534 	dev->type		= ARPHRD_PIMREG;
535 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
536 	dev->flags		= IFF_NOARP;
537 	dev->netdev_ops		= &reg_vif_netdev_ops;
538 	dev->needs_free_netdev	= true;
539 	dev->features		|= NETIF_F_NETNS_LOCAL;
540 }
541 
542 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
543 {
544 	struct net_device *dev;
545 	char name[IFNAMSIZ];
546 
547 	if (mrt->id == RT_TABLE_DEFAULT)
548 		sprintf(name, "pimreg");
549 	else
550 		sprintf(name, "pimreg%u", mrt->id);
551 
552 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
553 
554 	if (!dev)
555 		return NULL;
556 
557 	dev_net_set(dev, net);
558 
559 	if (register_netdevice(dev)) {
560 		free_netdev(dev);
561 		return NULL;
562 	}
563 
564 	if (!ipmr_init_vif_indev(dev))
565 		goto failure;
566 	if (dev_open(dev))
567 		goto failure;
568 
569 	dev_hold(dev);
570 
571 	return dev;
572 
573 failure:
574 	unregister_netdevice(dev);
575 	return NULL;
576 }
577 
578 /* called with rcu_read_lock() */
579 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
580 		     unsigned int pimlen)
581 {
582 	struct net_device *reg_dev = NULL;
583 	struct iphdr *encap;
584 
585 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
586 	/* Check that:
587 	 * a. packet is really sent to a multicast group
588 	 * b. packet is not a NULL-REGISTER
589 	 * c. packet is not truncated
590 	 */
591 	if (!ipv4_is_multicast(encap->daddr) ||
592 	    encap->tot_len == 0 ||
593 	    ntohs(encap->tot_len) + pimlen > skb->len)
594 		return 1;
595 
596 	read_lock(&mrt_lock);
597 	if (mrt->mroute_reg_vif_num >= 0)
598 		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
599 	read_unlock(&mrt_lock);
600 
601 	if (!reg_dev)
602 		return 1;
603 
604 	skb->mac_header = skb->network_header;
605 	skb_pull(skb, (u8 *)encap - skb->data);
606 	skb_reset_network_header(skb);
607 	skb->protocol = htons(ETH_P_IP);
608 	skb->ip_summed = CHECKSUM_NONE;
609 
610 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
611 
612 	netif_rx(skb);
613 
614 	return NET_RX_SUCCESS;
615 }
616 #else
617 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
618 {
619 	return NULL;
620 }
621 #endif
622 
623 static int call_ipmr_vif_entry_notifier(struct notifier_block *nb,
624 					struct net *net,
625 					enum fib_event_type event_type,
626 					struct vif_device *vif,
627 					vifi_t vif_index, u32 tb_id)
628 {
629 	struct vif_entry_notifier_info info = {
630 		.info = {
631 			.family = RTNL_FAMILY_IPMR,
632 			.net = net,
633 		},
634 		.dev = vif->dev,
635 		.vif_index = vif_index,
636 		.vif_flags = vif->flags,
637 		.tb_id = tb_id,
638 	};
639 
640 	return call_fib_notifier(nb, net, event_type, &info.info);
641 }
642 
643 static int call_ipmr_vif_entry_notifiers(struct net *net,
644 					 enum fib_event_type event_type,
645 					 struct vif_device *vif,
646 					 vifi_t vif_index, u32 tb_id)
647 {
648 	struct vif_entry_notifier_info info = {
649 		.info = {
650 			.family = RTNL_FAMILY_IPMR,
651 			.net = net,
652 		},
653 		.dev = vif->dev,
654 		.vif_index = vif_index,
655 		.vif_flags = vif->flags,
656 		.tb_id = tb_id,
657 	};
658 
659 	ASSERT_RTNL();
660 	net->ipv4.ipmr_seq++;
661 	return call_fib_notifiers(net, event_type, &info.info);
662 }
663 
664 static int call_ipmr_mfc_entry_notifier(struct notifier_block *nb,
665 					struct net *net,
666 					enum fib_event_type event_type,
667 					struct mfc_cache *mfc, u32 tb_id)
668 {
669 	struct mfc_entry_notifier_info info = {
670 		.info = {
671 			.family = RTNL_FAMILY_IPMR,
672 			.net = net,
673 		},
674 		.mfc = mfc,
675 		.tb_id = tb_id
676 	};
677 
678 	return call_fib_notifier(nb, net, event_type, &info.info);
679 }
680 
681 static int call_ipmr_mfc_entry_notifiers(struct net *net,
682 					 enum fib_event_type event_type,
683 					 struct mfc_cache *mfc, u32 tb_id)
684 {
685 	struct mfc_entry_notifier_info info = {
686 		.info = {
687 			.family = RTNL_FAMILY_IPMR,
688 			.net = net,
689 		},
690 		.mfc = mfc,
691 		.tb_id = tb_id
692 	};
693 
694 	ASSERT_RTNL();
695 	net->ipv4.ipmr_seq++;
696 	return call_fib_notifiers(net, event_type, &info.info);
697 }
698 
699 /**
700  *	vif_delete - Delete a VIF entry
701  *	@notify: Set to 1, if the caller is a notifier_call
702  */
703 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
704 		      struct list_head *head)
705 {
706 	struct net *net = read_pnet(&mrt->net);
707 	struct vif_device *v;
708 	struct net_device *dev;
709 	struct in_device *in_dev;
710 
711 	if (vifi < 0 || vifi >= mrt->maxvif)
712 		return -EADDRNOTAVAIL;
713 
714 	v = &mrt->vif_table[vifi];
715 
716 	if (VIF_EXISTS(mrt, vifi))
717 		call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_DEL, v, vifi,
718 					      mrt->id);
719 
720 	write_lock_bh(&mrt_lock);
721 	dev = v->dev;
722 	v->dev = NULL;
723 
724 	if (!dev) {
725 		write_unlock_bh(&mrt_lock);
726 		return -EADDRNOTAVAIL;
727 	}
728 
729 	if (vifi == mrt->mroute_reg_vif_num)
730 		mrt->mroute_reg_vif_num = -1;
731 
732 	if (vifi + 1 == mrt->maxvif) {
733 		int tmp;
734 
735 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
736 			if (VIF_EXISTS(mrt, tmp))
737 				break;
738 		}
739 		mrt->maxvif = tmp+1;
740 	}
741 
742 	write_unlock_bh(&mrt_lock);
743 
744 	dev_set_allmulti(dev, -1);
745 
746 	in_dev = __in_dev_get_rtnl(dev);
747 	if (in_dev) {
748 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
749 		inet_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
750 					    NETCONFA_MC_FORWARDING,
751 					    dev->ifindex, &in_dev->cnf);
752 		ip_rt_multicast_event(in_dev);
753 	}
754 
755 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
756 		unregister_netdevice_queue(dev, head);
757 
758 	dev_put(dev);
759 	return 0;
760 }
761 
762 static void ipmr_cache_free_rcu(struct rcu_head *head)
763 {
764 	struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
765 
766 	kmem_cache_free(mrt_cachep, c);
767 }
768 
769 void ipmr_cache_free(struct mfc_cache *c)
770 {
771 	call_rcu(&c->rcu, ipmr_cache_free_rcu);
772 }
773 EXPORT_SYMBOL(ipmr_cache_free);
774 
775 /* Destroy an unresolved cache entry, killing queued skbs
776  * and reporting error to netlink readers.
777  */
778 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
779 {
780 	struct net *net = read_pnet(&mrt->net);
781 	struct sk_buff *skb;
782 	struct nlmsgerr *e;
783 
784 	atomic_dec(&mrt->cache_resolve_queue_len);
785 
786 	while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
787 		if (ip_hdr(skb)->version == 0) {
788 			struct nlmsghdr *nlh = skb_pull(skb,
789 							sizeof(struct iphdr));
790 			nlh->nlmsg_type = NLMSG_ERROR;
791 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
792 			skb_trim(skb, nlh->nlmsg_len);
793 			e = nlmsg_data(nlh);
794 			e->error = -ETIMEDOUT;
795 			memset(&e->msg, 0, sizeof(e->msg));
796 
797 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
798 		} else {
799 			kfree_skb(skb);
800 		}
801 	}
802 
803 	ipmr_cache_free(c);
804 }
805 
806 /* Timer process for the unresolved queue. */
807 static void ipmr_expire_process(unsigned long arg)
808 {
809 	struct mr_table *mrt = (struct mr_table *)arg;
810 	unsigned long now;
811 	unsigned long expires;
812 	struct mfc_cache *c, *next;
813 
814 	if (!spin_trylock(&mfc_unres_lock)) {
815 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
816 		return;
817 	}
818 
819 	if (list_empty(&mrt->mfc_unres_queue))
820 		goto out;
821 
822 	now = jiffies;
823 	expires = 10*HZ;
824 
825 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
826 		if (time_after(c->mfc_un.unres.expires, now)) {
827 			unsigned long interval = c->mfc_un.unres.expires - now;
828 			if (interval < expires)
829 				expires = interval;
830 			continue;
831 		}
832 
833 		list_del(&c->list);
834 		mroute_netlink_event(mrt, c, RTM_DELROUTE);
835 		ipmr_destroy_unres(mrt, c);
836 	}
837 
838 	if (!list_empty(&mrt->mfc_unres_queue))
839 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
840 
841 out:
842 	spin_unlock(&mfc_unres_lock);
843 }
844 
845 /* Fill oifs list. It is called under write locked mrt_lock. */
846 static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
847 				   unsigned char *ttls)
848 {
849 	int vifi;
850 
851 	cache->mfc_un.res.minvif = MAXVIFS;
852 	cache->mfc_un.res.maxvif = 0;
853 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
854 
855 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
856 		if (VIF_EXISTS(mrt, vifi) &&
857 		    ttls[vifi] && ttls[vifi] < 255) {
858 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
859 			if (cache->mfc_un.res.minvif > vifi)
860 				cache->mfc_un.res.minvif = vifi;
861 			if (cache->mfc_un.res.maxvif <= vifi)
862 				cache->mfc_un.res.maxvif = vifi + 1;
863 		}
864 	}
865 	cache->mfc_un.res.lastuse = jiffies;
866 }
867 
868 static int vif_add(struct net *net, struct mr_table *mrt,
869 		   struct vifctl *vifc, int mrtsock)
870 {
871 	int vifi = vifc->vifc_vifi;
872 	struct switchdev_attr attr = {
873 		.id = SWITCHDEV_ATTR_ID_PORT_PARENT_ID,
874 	};
875 	struct vif_device *v = &mrt->vif_table[vifi];
876 	struct net_device *dev;
877 	struct in_device *in_dev;
878 	int err;
879 
880 	/* Is vif busy ? */
881 	if (VIF_EXISTS(mrt, vifi))
882 		return -EADDRINUSE;
883 
884 	switch (vifc->vifc_flags) {
885 	case VIFF_REGISTER:
886 		if (!ipmr_pimsm_enabled())
887 			return -EINVAL;
888 		/* Special Purpose VIF in PIM
889 		 * All the packets will be sent to the daemon
890 		 */
891 		if (mrt->mroute_reg_vif_num >= 0)
892 			return -EADDRINUSE;
893 		dev = ipmr_reg_vif(net, mrt);
894 		if (!dev)
895 			return -ENOBUFS;
896 		err = dev_set_allmulti(dev, 1);
897 		if (err) {
898 			unregister_netdevice(dev);
899 			dev_put(dev);
900 			return err;
901 		}
902 		break;
903 	case VIFF_TUNNEL:
904 		dev = ipmr_new_tunnel(net, vifc);
905 		if (!dev)
906 			return -ENOBUFS;
907 		err = dev_set_allmulti(dev, 1);
908 		if (err) {
909 			ipmr_del_tunnel(dev, vifc);
910 			dev_put(dev);
911 			return err;
912 		}
913 		break;
914 	case VIFF_USE_IFINDEX:
915 	case 0:
916 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
917 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
918 			if (dev && !__in_dev_get_rtnl(dev)) {
919 				dev_put(dev);
920 				return -EADDRNOTAVAIL;
921 			}
922 		} else {
923 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
924 		}
925 		if (!dev)
926 			return -EADDRNOTAVAIL;
927 		err = dev_set_allmulti(dev, 1);
928 		if (err) {
929 			dev_put(dev);
930 			return err;
931 		}
932 		break;
933 	default:
934 		return -EINVAL;
935 	}
936 
937 	in_dev = __in_dev_get_rtnl(dev);
938 	if (!in_dev) {
939 		dev_put(dev);
940 		return -EADDRNOTAVAIL;
941 	}
942 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
943 	inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING,
944 				    dev->ifindex, &in_dev->cnf);
945 	ip_rt_multicast_event(in_dev);
946 
947 	/* Fill in the VIF structures */
948 
949 	attr.orig_dev = dev;
950 	if (!switchdev_port_attr_get(dev, &attr)) {
951 		memcpy(v->dev_parent_id.id, attr.u.ppid.id, attr.u.ppid.id_len);
952 		v->dev_parent_id.id_len = attr.u.ppid.id_len;
953 	} else {
954 		v->dev_parent_id.id_len = 0;
955 	}
956 	v->rate_limit = vifc->vifc_rate_limit;
957 	v->local = vifc->vifc_lcl_addr.s_addr;
958 	v->remote = vifc->vifc_rmt_addr.s_addr;
959 	v->flags = vifc->vifc_flags;
960 	if (!mrtsock)
961 		v->flags |= VIFF_STATIC;
962 	v->threshold = vifc->vifc_threshold;
963 	v->bytes_in = 0;
964 	v->bytes_out = 0;
965 	v->pkt_in = 0;
966 	v->pkt_out = 0;
967 	v->link = dev->ifindex;
968 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
969 		v->link = dev_get_iflink(dev);
970 
971 	/* And finish update writing critical data */
972 	write_lock_bh(&mrt_lock);
973 	v->dev = dev;
974 	if (v->flags & VIFF_REGISTER)
975 		mrt->mroute_reg_vif_num = vifi;
976 	if (vifi+1 > mrt->maxvif)
977 		mrt->maxvif = vifi+1;
978 	write_unlock_bh(&mrt_lock);
979 	call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD, v, vifi, mrt->id);
980 	return 0;
981 }
982 
983 /* called with rcu_read_lock() */
984 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
985 					 __be32 origin,
986 					 __be32 mcastgrp)
987 {
988 	struct mfc_cache_cmp_arg arg = {
989 			.mfc_mcastgrp = mcastgrp,
990 			.mfc_origin = origin
991 	};
992 	struct rhlist_head *tmp, *list;
993 	struct mfc_cache *c;
994 
995 	list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
996 	rhl_for_each_entry_rcu(c, tmp, list, mnode)
997 		return c;
998 
999 	return NULL;
1000 }
1001 
1002 /* Look for a (*,*,oif) entry */
1003 static struct mfc_cache *ipmr_cache_find_any_parent(struct mr_table *mrt,
1004 						    int vifi)
1005 {
1006 	struct mfc_cache_cmp_arg arg = {
1007 			.mfc_mcastgrp = htonl(INADDR_ANY),
1008 			.mfc_origin = htonl(INADDR_ANY)
1009 	};
1010 	struct rhlist_head *tmp, *list;
1011 	struct mfc_cache *c;
1012 
1013 	list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
1014 	rhl_for_each_entry_rcu(c, tmp, list, mnode)
1015 		if (c->mfc_un.res.ttls[vifi] < 255)
1016 			return c;
1017 
1018 	return NULL;
1019 }
1020 
1021 /* Look for a (*,G) entry */
1022 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
1023 					     __be32 mcastgrp, int vifi)
1024 {
1025 	struct mfc_cache_cmp_arg arg = {
1026 			.mfc_mcastgrp = mcastgrp,
1027 			.mfc_origin = htonl(INADDR_ANY)
1028 	};
1029 	struct rhlist_head *tmp, *list;
1030 	struct mfc_cache *c, *proxy;
1031 
1032 	if (mcastgrp == htonl(INADDR_ANY))
1033 		goto skip;
1034 
1035 	list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
1036 	rhl_for_each_entry_rcu(c, tmp, list, mnode) {
1037 		if (c->mfc_un.res.ttls[vifi] < 255)
1038 			return c;
1039 
1040 		/* It's ok if the vifi is part of the static tree */
1041 		proxy = ipmr_cache_find_any_parent(mrt, c->mfc_parent);
1042 		if (proxy && proxy->mfc_un.res.ttls[vifi] < 255)
1043 			return c;
1044 	}
1045 
1046 skip:
1047 	return ipmr_cache_find_any_parent(mrt, vifi);
1048 }
1049 
1050 /* Look for a (S,G,iif) entry if parent != -1 */
1051 static struct mfc_cache *ipmr_cache_find_parent(struct mr_table *mrt,
1052 						__be32 origin, __be32 mcastgrp,
1053 						int parent)
1054 {
1055 	struct mfc_cache_cmp_arg arg = {
1056 			.mfc_mcastgrp = mcastgrp,
1057 			.mfc_origin = origin,
1058 	};
1059 	struct rhlist_head *tmp, *list;
1060 	struct mfc_cache *c;
1061 
1062 	list = rhltable_lookup(&mrt->mfc_hash, &arg, ipmr_rht_params);
1063 	rhl_for_each_entry_rcu(c, tmp, list, mnode)
1064 		if (parent == -1 || parent == c->mfc_parent)
1065 			return c;
1066 
1067 	return NULL;
1068 }
1069 
1070 /* Allocate a multicast cache entry */
1071 static struct mfc_cache *ipmr_cache_alloc(void)
1072 {
1073 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
1074 
1075 	if (c) {
1076 		c->mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
1077 		c->mfc_un.res.minvif = MAXVIFS;
1078 		refcount_set(&c->mfc_un.res.refcount, 1);
1079 	}
1080 	return c;
1081 }
1082 
1083 static struct mfc_cache *ipmr_cache_alloc_unres(void)
1084 {
1085 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
1086 
1087 	if (c) {
1088 		skb_queue_head_init(&c->mfc_un.unres.unresolved);
1089 		c->mfc_un.unres.expires = jiffies + 10*HZ;
1090 	}
1091 	return c;
1092 }
1093 
1094 /* A cache entry has gone into a resolved state from queued */
1095 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
1096 			       struct mfc_cache *uc, struct mfc_cache *c)
1097 {
1098 	struct sk_buff *skb;
1099 	struct nlmsgerr *e;
1100 
1101 	/* Play the pending entries through our router */
1102 	while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
1103 		if (ip_hdr(skb)->version == 0) {
1104 			struct nlmsghdr *nlh = skb_pull(skb,
1105 							sizeof(struct iphdr));
1106 
1107 			if (__ipmr_fill_mroute(mrt, skb, c, nlmsg_data(nlh)) > 0) {
1108 				nlh->nlmsg_len = skb_tail_pointer(skb) -
1109 						 (u8 *)nlh;
1110 			} else {
1111 				nlh->nlmsg_type = NLMSG_ERROR;
1112 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
1113 				skb_trim(skb, nlh->nlmsg_len);
1114 				e = nlmsg_data(nlh);
1115 				e->error = -EMSGSIZE;
1116 				memset(&e->msg, 0, sizeof(e->msg));
1117 			}
1118 
1119 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
1120 		} else {
1121 			ip_mr_forward(net, mrt, skb->dev, skb, c, 0);
1122 		}
1123 	}
1124 }
1125 
1126 /* Bounce a cache query up to mrouted and netlink.
1127  *
1128  * Called under mrt_lock.
1129  */
1130 static int ipmr_cache_report(struct mr_table *mrt,
1131 			     struct sk_buff *pkt, vifi_t vifi, int assert)
1132 {
1133 	const int ihl = ip_hdrlen(pkt);
1134 	struct sock *mroute_sk;
1135 	struct igmphdr *igmp;
1136 	struct igmpmsg *msg;
1137 	struct sk_buff *skb;
1138 	int ret;
1139 
1140 	if (assert == IGMPMSG_WHOLEPKT)
1141 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
1142 	else
1143 		skb = alloc_skb(128, GFP_ATOMIC);
1144 
1145 	if (!skb)
1146 		return -ENOBUFS;
1147 
1148 	if (assert == IGMPMSG_WHOLEPKT) {
1149 		/* Ugly, but we have no choice with this interface.
1150 		 * Duplicate old header, fix ihl, length etc.
1151 		 * And all this only to mangle msg->im_msgtype and
1152 		 * to set msg->im_mbz to "mbz" :-)
1153 		 */
1154 		skb_push(skb, sizeof(struct iphdr));
1155 		skb_reset_network_header(skb);
1156 		skb_reset_transport_header(skb);
1157 		msg = (struct igmpmsg *)skb_network_header(skb);
1158 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
1159 		msg->im_msgtype = IGMPMSG_WHOLEPKT;
1160 		msg->im_mbz = 0;
1161 		msg->im_vif = mrt->mroute_reg_vif_num;
1162 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
1163 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
1164 					     sizeof(struct iphdr));
1165 	} else {
1166 		/* Copy the IP header */
1167 		skb_set_network_header(skb, skb->len);
1168 		skb_put(skb, ihl);
1169 		skb_copy_to_linear_data(skb, pkt->data, ihl);
1170 		/* Flag to the kernel this is a route add */
1171 		ip_hdr(skb)->protocol = 0;
1172 		msg = (struct igmpmsg *)skb_network_header(skb);
1173 		msg->im_vif = vifi;
1174 		skb_dst_set(skb, dst_clone(skb_dst(pkt)));
1175 		/* Add our header */
1176 		igmp = skb_put(skb, sizeof(struct igmphdr));
1177 		igmp->type = assert;
1178 		msg->im_msgtype = assert;
1179 		igmp->code = 0;
1180 		ip_hdr(skb)->tot_len = htons(skb->len);	/* Fix the length */
1181 		skb->transport_header = skb->network_header;
1182 	}
1183 
1184 	rcu_read_lock();
1185 	mroute_sk = rcu_dereference(mrt->mroute_sk);
1186 	if (!mroute_sk) {
1187 		rcu_read_unlock();
1188 		kfree_skb(skb);
1189 		return -EINVAL;
1190 	}
1191 
1192 	igmpmsg_netlink_event(mrt, skb);
1193 
1194 	/* Deliver to mrouted */
1195 	ret = sock_queue_rcv_skb(mroute_sk, skb);
1196 	rcu_read_unlock();
1197 	if (ret < 0) {
1198 		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1199 		kfree_skb(skb);
1200 	}
1201 
1202 	return ret;
1203 }
1204 
1205 /* Queue a packet for resolution. It gets locked cache entry! */
1206 static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
1207 				 struct sk_buff *skb, struct net_device *dev)
1208 {
1209 	const struct iphdr *iph = ip_hdr(skb);
1210 	struct mfc_cache *c;
1211 	bool found = false;
1212 	int err;
1213 
1214 	spin_lock_bh(&mfc_unres_lock);
1215 	list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
1216 		if (c->mfc_mcastgrp == iph->daddr &&
1217 		    c->mfc_origin == iph->saddr) {
1218 			found = true;
1219 			break;
1220 		}
1221 	}
1222 
1223 	if (!found) {
1224 		/* Create a new entry if allowable */
1225 		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
1226 		    (c = ipmr_cache_alloc_unres()) == NULL) {
1227 			spin_unlock_bh(&mfc_unres_lock);
1228 
1229 			kfree_skb(skb);
1230 			return -ENOBUFS;
1231 		}
1232 
1233 		/* Fill in the new cache entry */
1234 		c->mfc_parent	= -1;
1235 		c->mfc_origin	= iph->saddr;
1236 		c->mfc_mcastgrp	= iph->daddr;
1237 
1238 		/* Reflect first query at mrouted. */
1239 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1240 		if (err < 0) {
1241 			/* If the report failed throw the cache entry
1242 			   out - Brad Parker
1243 			 */
1244 			spin_unlock_bh(&mfc_unres_lock);
1245 
1246 			ipmr_cache_free(c);
1247 			kfree_skb(skb);
1248 			return err;
1249 		}
1250 
1251 		atomic_inc(&mrt->cache_resolve_queue_len);
1252 		list_add(&c->list, &mrt->mfc_unres_queue);
1253 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1254 
1255 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1256 			mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1257 	}
1258 
1259 	/* See if we can append the packet */
1260 	if (c->mfc_un.unres.unresolved.qlen > 3) {
1261 		kfree_skb(skb);
1262 		err = -ENOBUFS;
1263 	} else {
1264 		if (dev) {
1265 			skb->dev = dev;
1266 			skb->skb_iif = dev->ifindex;
1267 		}
1268 		skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1269 		err = 0;
1270 	}
1271 
1272 	spin_unlock_bh(&mfc_unres_lock);
1273 	return err;
1274 }
1275 
1276 /* MFC cache manipulation by user space mroute daemon */
1277 
1278 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1279 {
1280 	struct net *net = read_pnet(&mrt->net);
1281 	struct mfc_cache *c;
1282 
1283 	/* The entries are added/deleted only under RTNL */
1284 	rcu_read_lock();
1285 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1286 				   mfc->mfcc_mcastgrp.s_addr, parent);
1287 	rcu_read_unlock();
1288 	if (!c)
1289 		return -ENOENT;
1290 	rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
1291 	list_del_rcu(&c->list);
1292 	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, c, mrt->id);
1293 	mroute_netlink_event(mrt, c, RTM_DELROUTE);
1294 	ipmr_cache_put(c);
1295 
1296 	return 0;
1297 }
1298 
1299 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1300 			struct mfcctl *mfc, int mrtsock, int parent)
1301 {
1302 	struct mfc_cache *uc, *c;
1303 	bool found;
1304 	int ret;
1305 
1306 	if (mfc->mfcc_parent >= MAXVIFS)
1307 		return -ENFILE;
1308 
1309 	/* The entries are added/deleted only under RTNL */
1310 	rcu_read_lock();
1311 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1312 				   mfc->mfcc_mcastgrp.s_addr, parent);
1313 	rcu_read_unlock();
1314 	if (c) {
1315 		write_lock_bh(&mrt_lock);
1316 		c->mfc_parent = mfc->mfcc_parent;
1317 		ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1318 		if (!mrtsock)
1319 			c->mfc_flags |= MFC_STATIC;
1320 		write_unlock_bh(&mrt_lock);
1321 		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, c,
1322 					      mrt->id);
1323 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1324 		return 0;
1325 	}
1326 
1327 	if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1328 	    !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1329 		return -EINVAL;
1330 
1331 	c = ipmr_cache_alloc();
1332 	if (!c)
1333 		return -ENOMEM;
1334 
1335 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1336 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1337 	c->mfc_parent = mfc->mfcc_parent;
1338 	ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1339 	if (!mrtsock)
1340 		c->mfc_flags |= MFC_STATIC;
1341 
1342 	ret = rhltable_insert_key(&mrt->mfc_hash, &c->cmparg, &c->mnode,
1343 				  ipmr_rht_params);
1344 	if (ret) {
1345 		pr_err("ipmr: rhtable insert error %d\n", ret);
1346 		ipmr_cache_free(c);
1347 		return ret;
1348 	}
1349 	list_add_tail_rcu(&c->list, &mrt->mfc_cache_list);
1350 	/* Check to see if we resolved a queued list. If so we
1351 	 * need to send on the frames and tidy up.
1352 	 */
1353 	found = false;
1354 	spin_lock_bh(&mfc_unres_lock);
1355 	list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1356 		if (uc->mfc_origin == c->mfc_origin &&
1357 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1358 			list_del(&uc->list);
1359 			atomic_dec(&mrt->cache_resolve_queue_len);
1360 			found = true;
1361 			break;
1362 		}
1363 	}
1364 	if (list_empty(&mrt->mfc_unres_queue))
1365 		del_timer(&mrt->ipmr_expire_timer);
1366 	spin_unlock_bh(&mfc_unres_lock);
1367 
1368 	if (found) {
1369 		ipmr_cache_resolve(net, mrt, uc, c);
1370 		ipmr_cache_free(uc);
1371 	}
1372 	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, c, mrt->id);
1373 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1374 	return 0;
1375 }
1376 
1377 /* Close the multicast socket, and clear the vif tables etc */
1378 static void mroute_clean_tables(struct mr_table *mrt, bool all)
1379 {
1380 	struct net *net = read_pnet(&mrt->net);
1381 	struct mfc_cache *c, *tmp;
1382 	LIST_HEAD(list);
1383 	int i;
1384 
1385 	/* Shut down all active vif entries */
1386 	for (i = 0; i < mrt->maxvif; i++) {
1387 		if (!all && (mrt->vif_table[i].flags & VIFF_STATIC))
1388 			continue;
1389 		vif_delete(mrt, i, 0, &list);
1390 	}
1391 	unregister_netdevice_many(&list);
1392 
1393 	/* Wipe the cache */
1394 	list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
1395 		if (!all && (c->mfc_flags & MFC_STATIC))
1396 			continue;
1397 		rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
1398 		list_del_rcu(&c->list);
1399 		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, c,
1400 					      mrt->id);
1401 		mroute_netlink_event(mrt, c, RTM_DELROUTE);
1402 		ipmr_cache_put(c);
1403 	}
1404 
1405 	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1406 		spin_lock_bh(&mfc_unres_lock);
1407 		list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
1408 			list_del(&c->list);
1409 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1410 			ipmr_destroy_unres(mrt, c);
1411 		}
1412 		spin_unlock_bh(&mfc_unres_lock);
1413 	}
1414 }
1415 
1416 /* called from ip_ra_control(), before an RCU grace period,
1417  * we dont need to call synchronize_rcu() here
1418  */
1419 static void mrtsock_destruct(struct sock *sk)
1420 {
1421 	struct net *net = sock_net(sk);
1422 	struct mr_table *mrt;
1423 
1424 	ASSERT_RTNL();
1425 	ipmr_for_each_table(mrt, net) {
1426 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1427 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1428 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1429 						    NETCONFA_MC_FORWARDING,
1430 						    NETCONFA_IFINDEX_ALL,
1431 						    net->ipv4.devconf_all);
1432 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1433 			mroute_clean_tables(mrt, false);
1434 		}
1435 	}
1436 }
1437 
1438 /* Socket options and virtual interface manipulation. The whole
1439  * virtual interface system is a complete heap, but unfortunately
1440  * that's how BSD mrouted happens to think. Maybe one day with a proper
1441  * MOSPF/PIM router set up we can clean this up.
1442  */
1443 
1444 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
1445 			 unsigned int optlen)
1446 {
1447 	struct net *net = sock_net(sk);
1448 	int val, ret = 0, parent = 0;
1449 	struct mr_table *mrt;
1450 	struct vifctl vif;
1451 	struct mfcctl mfc;
1452 	u32 uval;
1453 
1454 	/* There's one exception to the lock - MRT_DONE which needs to unlock */
1455 	rtnl_lock();
1456 	if (sk->sk_type != SOCK_RAW ||
1457 	    inet_sk(sk)->inet_num != IPPROTO_IGMP) {
1458 		ret = -EOPNOTSUPP;
1459 		goto out_unlock;
1460 	}
1461 
1462 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1463 	if (!mrt) {
1464 		ret = -ENOENT;
1465 		goto out_unlock;
1466 	}
1467 	if (optname != MRT_INIT) {
1468 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1469 		    !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
1470 			ret = -EACCES;
1471 			goto out_unlock;
1472 		}
1473 	}
1474 
1475 	switch (optname) {
1476 	case MRT_INIT:
1477 		if (optlen != sizeof(int)) {
1478 			ret = -EINVAL;
1479 			break;
1480 		}
1481 		if (rtnl_dereference(mrt->mroute_sk)) {
1482 			ret = -EADDRINUSE;
1483 			break;
1484 		}
1485 
1486 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1487 		if (ret == 0) {
1488 			rcu_assign_pointer(mrt->mroute_sk, sk);
1489 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1490 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1491 						    NETCONFA_MC_FORWARDING,
1492 						    NETCONFA_IFINDEX_ALL,
1493 						    net->ipv4.devconf_all);
1494 		}
1495 		break;
1496 	case MRT_DONE:
1497 		if (sk != rcu_access_pointer(mrt->mroute_sk)) {
1498 			ret = -EACCES;
1499 		} else {
1500 			ret = ip_ra_control(sk, 0, NULL);
1501 			goto out_unlock;
1502 		}
1503 		break;
1504 	case MRT_ADD_VIF:
1505 	case MRT_DEL_VIF:
1506 		if (optlen != sizeof(vif)) {
1507 			ret = -EINVAL;
1508 			break;
1509 		}
1510 		if (copy_from_user(&vif, optval, sizeof(vif))) {
1511 			ret = -EFAULT;
1512 			break;
1513 		}
1514 		if (vif.vifc_vifi >= MAXVIFS) {
1515 			ret = -ENFILE;
1516 			break;
1517 		}
1518 		if (optname == MRT_ADD_VIF) {
1519 			ret = vif_add(net, mrt, &vif,
1520 				      sk == rtnl_dereference(mrt->mroute_sk));
1521 		} else {
1522 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1523 		}
1524 		break;
1525 	/* Manipulate the forwarding caches. These live
1526 	 * in a sort of kernel/user symbiosis.
1527 	 */
1528 	case MRT_ADD_MFC:
1529 	case MRT_DEL_MFC:
1530 		parent = -1;
1531 		/* fall through */
1532 	case MRT_ADD_MFC_PROXY:
1533 	case MRT_DEL_MFC_PROXY:
1534 		if (optlen != sizeof(mfc)) {
1535 			ret = -EINVAL;
1536 			break;
1537 		}
1538 		if (copy_from_user(&mfc, optval, sizeof(mfc))) {
1539 			ret = -EFAULT;
1540 			break;
1541 		}
1542 		if (parent == 0)
1543 			parent = mfc.mfcc_parent;
1544 		if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1545 			ret = ipmr_mfc_delete(mrt, &mfc, parent);
1546 		else
1547 			ret = ipmr_mfc_add(net, mrt, &mfc,
1548 					   sk == rtnl_dereference(mrt->mroute_sk),
1549 					   parent);
1550 		break;
1551 	/* Control PIM assert. */
1552 	case MRT_ASSERT:
1553 		if (optlen != sizeof(val)) {
1554 			ret = -EINVAL;
1555 			break;
1556 		}
1557 		if (get_user(val, (int __user *)optval)) {
1558 			ret = -EFAULT;
1559 			break;
1560 		}
1561 		mrt->mroute_do_assert = val;
1562 		break;
1563 	case MRT_PIM:
1564 		if (!ipmr_pimsm_enabled()) {
1565 			ret = -ENOPROTOOPT;
1566 			break;
1567 		}
1568 		if (optlen != sizeof(val)) {
1569 			ret = -EINVAL;
1570 			break;
1571 		}
1572 		if (get_user(val, (int __user *)optval)) {
1573 			ret = -EFAULT;
1574 			break;
1575 		}
1576 
1577 		val = !!val;
1578 		if (val != mrt->mroute_do_pim) {
1579 			mrt->mroute_do_pim = val;
1580 			mrt->mroute_do_assert = val;
1581 		}
1582 		break;
1583 	case MRT_TABLE:
1584 		if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) {
1585 			ret = -ENOPROTOOPT;
1586 			break;
1587 		}
1588 		if (optlen != sizeof(uval)) {
1589 			ret = -EINVAL;
1590 			break;
1591 		}
1592 		if (get_user(uval, (u32 __user *)optval)) {
1593 			ret = -EFAULT;
1594 			break;
1595 		}
1596 
1597 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1598 			ret = -EBUSY;
1599 		} else {
1600 			mrt = ipmr_new_table(net, uval);
1601 			if (IS_ERR(mrt))
1602 				ret = PTR_ERR(mrt);
1603 			else
1604 				raw_sk(sk)->ipmr_table = uval;
1605 		}
1606 		break;
1607 	/* Spurious command, or MRT_VERSION which you cannot set. */
1608 	default:
1609 		ret = -ENOPROTOOPT;
1610 	}
1611 out_unlock:
1612 	rtnl_unlock();
1613 	return ret;
1614 }
1615 
1616 /* Getsock opt support for the multicast routing system. */
1617 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1618 {
1619 	int olr;
1620 	int val;
1621 	struct net *net = sock_net(sk);
1622 	struct mr_table *mrt;
1623 
1624 	if (sk->sk_type != SOCK_RAW ||
1625 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1626 		return -EOPNOTSUPP;
1627 
1628 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1629 	if (!mrt)
1630 		return -ENOENT;
1631 
1632 	switch (optname) {
1633 	case MRT_VERSION:
1634 		val = 0x0305;
1635 		break;
1636 	case MRT_PIM:
1637 		if (!ipmr_pimsm_enabled())
1638 			return -ENOPROTOOPT;
1639 		val = mrt->mroute_do_pim;
1640 		break;
1641 	case MRT_ASSERT:
1642 		val = mrt->mroute_do_assert;
1643 		break;
1644 	default:
1645 		return -ENOPROTOOPT;
1646 	}
1647 
1648 	if (get_user(olr, optlen))
1649 		return -EFAULT;
1650 	olr = min_t(unsigned int, olr, sizeof(int));
1651 	if (olr < 0)
1652 		return -EINVAL;
1653 	if (put_user(olr, optlen))
1654 		return -EFAULT;
1655 	if (copy_to_user(optval, &val, olr))
1656 		return -EFAULT;
1657 	return 0;
1658 }
1659 
1660 /* The IP multicast ioctl support routines. */
1661 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1662 {
1663 	struct sioc_sg_req sr;
1664 	struct sioc_vif_req vr;
1665 	struct vif_device *vif;
1666 	struct mfc_cache *c;
1667 	struct net *net = sock_net(sk);
1668 	struct mr_table *mrt;
1669 
1670 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1671 	if (!mrt)
1672 		return -ENOENT;
1673 
1674 	switch (cmd) {
1675 	case SIOCGETVIFCNT:
1676 		if (copy_from_user(&vr, arg, sizeof(vr)))
1677 			return -EFAULT;
1678 		if (vr.vifi >= mrt->maxvif)
1679 			return -EINVAL;
1680 		read_lock(&mrt_lock);
1681 		vif = &mrt->vif_table[vr.vifi];
1682 		if (VIF_EXISTS(mrt, vr.vifi)) {
1683 			vr.icount = vif->pkt_in;
1684 			vr.ocount = vif->pkt_out;
1685 			vr.ibytes = vif->bytes_in;
1686 			vr.obytes = vif->bytes_out;
1687 			read_unlock(&mrt_lock);
1688 
1689 			if (copy_to_user(arg, &vr, sizeof(vr)))
1690 				return -EFAULT;
1691 			return 0;
1692 		}
1693 		read_unlock(&mrt_lock);
1694 		return -EADDRNOTAVAIL;
1695 	case SIOCGETSGCNT:
1696 		if (copy_from_user(&sr, arg, sizeof(sr)))
1697 			return -EFAULT;
1698 
1699 		rcu_read_lock();
1700 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1701 		if (c) {
1702 			sr.pktcnt = c->mfc_un.res.pkt;
1703 			sr.bytecnt = c->mfc_un.res.bytes;
1704 			sr.wrong_if = c->mfc_un.res.wrong_if;
1705 			rcu_read_unlock();
1706 
1707 			if (copy_to_user(arg, &sr, sizeof(sr)))
1708 				return -EFAULT;
1709 			return 0;
1710 		}
1711 		rcu_read_unlock();
1712 		return -EADDRNOTAVAIL;
1713 	default:
1714 		return -ENOIOCTLCMD;
1715 	}
1716 }
1717 
1718 #ifdef CONFIG_COMPAT
1719 struct compat_sioc_sg_req {
1720 	struct in_addr src;
1721 	struct in_addr grp;
1722 	compat_ulong_t pktcnt;
1723 	compat_ulong_t bytecnt;
1724 	compat_ulong_t wrong_if;
1725 };
1726 
1727 struct compat_sioc_vif_req {
1728 	vifi_t	vifi;		/* Which iface */
1729 	compat_ulong_t icount;
1730 	compat_ulong_t ocount;
1731 	compat_ulong_t ibytes;
1732 	compat_ulong_t obytes;
1733 };
1734 
1735 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1736 {
1737 	struct compat_sioc_sg_req sr;
1738 	struct compat_sioc_vif_req vr;
1739 	struct vif_device *vif;
1740 	struct mfc_cache *c;
1741 	struct net *net = sock_net(sk);
1742 	struct mr_table *mrt;
1743 
1744 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1745 	if (!mrt)
1746 		return -ENOENT;
1747 
1748 	switch (cmd) {
1749 	case SIOCGETVIFCNT:
1750 		if (copy_from_user(&vr, arg, sizeof(vr)))
1751 			return -EFAULT;
1752 		if (vr.vifi >= mrt->maxvif)
1753 			return -EINVAL;
1754 		read_lock(&mrt_lock);
1755 		vif = &mrt->vif_table[vr.vifi];
1756 		if (VIF_EXISTS(mrt, vr.vifi)) {
1757 			vr.icount = vif->pkt_in;
1758 			vr.ocount = vif->pkt_out;
1759 			vr.ibytes = vif->bytes_in;
1760 			vr.obytes = vif->bytes_out;
1761 			read_unlock(&mrt_lock);
1762 
1763 			if (copy_to_user(arg, &vr, sizeof(vr)))
1764 				return -EFAULT;
1765 			return 0;
1766 		}
1767 		read_unlock(&mrt_lock);
1768 		return -EADDRNOTAVAIL;
1769 	case SIOCGETSGCNT:
1770 		if (copy_from_user(&sr, arg, sizeof(sr)))
1771 			return -EFAULT;
1772 
1773 		rcu_read_lock();
1774 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1775 		if (c) {
1776 			sr.pktcnt = c->mfc_un.res.pkt;
1777 			sr.bytecnt = c->mfc_un.res.bytes;
1778 			sr.wrong_if = c->mfc_un.res.wrong_if;
1779 			rcu_read_unlock();
1780 
1781 			if (copy_to_user(arg, &sr, sizeof(sr)))
1782 				return -EFAULT;
1783 			return 0;
1784 		}
1785 		rcu_read_unlock();
1786 		return -EADDRNOTAVAIL;
1787 	default:
1788 		return -ENOIOCTLCMD;
1789 	}
1790 }
1791 #endif
1792 
1793 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1794 {
1795 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1796 	struct net *net = dev_net(dev);
1797 	struct mr_table *mrt;
1798 	struct vif_device *v;
1799 	int ct;
1800 
1801 	if (event != NETDEV_UNREGISTER)
1802 		return NOTIFY_DONE;
1803 
1804 	ipmr_for_each_table(mrt, net) {
1805 		v = &mrt->vif_table[0];
1806 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1807 			if (v->dev == dev)
1808 				vif_delete(mrt, ct, 1, NULL);
1809 		}
1810 	}
1811 	return NOTIFY_DONE;
1812 }
1813 
1814 static struct notifier_block ip_mr_notifier = {
1815 	.notifier_call = ipmr_device_event,
1816 };
1817 
1818 /* Encapsulate a packet by attaching a valid IPIP header to it.
1819  * This avoids tunnel drivers and other mess and gives us the speed so
1820  * important for multicast video.
1821  */
1822 static void ip_encap(struct net *net, struct sk_buff *skb,
1823 		     __be32 saddr, __be32 daddr)
1824 {
1825 	struct iphdr *iph;
1826 	const struct iphdr *old_iph = ip_hdr(skb);
1827 
1828 	skb_push(skb, sizeof(struct iphdr));
1829 	skb->transport_header = skb->network_header;
1830 	skb_reset_network_header(skb);
1831 	iph = ip_hdr(skb);
1832 
1833 	iph->version	=	4;
1834 	iph->tos	=	old_iph->tos;
1835 	iph->ttl	=	old_iph->ttl;
1836 	iph->frag_off	=	0;
1837 	iph->daddr	=	daddr;
1838 	iph->saddr	=	saddr;
1839 	iph->protocol	=	IPPROTO_IPIP;
1840 	iph->ihl	=	5;
1841 	iph->tot_len	=	htons(skb->len);
1842 	ip_select_ident(net, skb, NULL);
1843 	ip_send_check(iph);
1844 
1845 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1846 	nf_reset(skb);
1847 }
1848 
1849 static inline int ipmr_forward_finish(struct net *net, struct sock *sk,
1850 				      struct sk_buff *skb)
1851 {
1852 	struct ip_options *opt = &(IPCB(skb)->opt);
1853 
1854 	IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
1855 	IP_ADD_STATS(net, IPSTATS_MIB_OUTOCTETS, skb->len);
1856 
1857 	if (unlikely(opt->optlen))
1858 		ip_forward_options(skb);
1859 
1860 	return dst_output(net, sk, skb);
1861 }
1862 
1863 #ifdef CONFIG_NET_SWITCHDEV
1864 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1865 				   int in_vifi, int out_vifi)
1866 {
1867 	struct vif_device *out_vif = &mrt->vif_table[out_vifi];
1868 	struct vif_device *in_vif = &mrt->vif_table[in_vifi];
1869 
1870 	if (!skb->offload_mr_fwd_mark)
1871 		return false;
1872 	if (!out_vif->dev_parent_id.id_len || !in_vif->dev_parent_id.id_len)
1873 		return false;
1874 	return netdev_phys_item_id_same(&out_vif->dev_parent_id,
1875 					&in_vif->dev_parent_id);
1876 }
1877 #else
1878 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1879 				   int in_vifi, int out_vifi)
1880 {
1881 	return false;
1882 }
1883 #endif
1884 
1885 /* Processing handlers for ipmr_forward */
1886 
1887 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1888 			    int in_vifi, struct sk_buff *skb,
1889 			    struct mfc_cache *c, int vifi)
1890 {
1891 	const struct iphdr *iph = ip_hdr(skb);
1892 	struct vif_device *vif = &mrt->vif_table[vifi];
1893 	struct net_device *dev;
1894 	struct rtable *rt;
1895 	struct flowi4 fl4;
1896 	int    encap = 0;
1897 
1898 	if (!vif->dev)
1899 		goto out_free;
1900 
1901 	if (vif->flags & VIFF_REGISTER) {
1902 		vif->pkt_out++;
1903 		vif->bytes_out += skb->len;
1904 		vif->dev->stats.tx_bytes += skb->len;
1905 		vif->dev->stats.tx_packets++;
1906 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1907 		goto out_free;
1908 	}
1909 
1910 	if (ipmr_forward_offloaded(skb, mrt, in_vifi, vifi))
1911 		goto out_free;
1912 
1913 	if (vif->flags & VIFF_TUNNEL) {
1914 		rt = ip_route_output_ports(net, &fl4, NULL,
1915 					   vif->remote, vif->local,
1916 					   0, 0,
1917 					   IPPROTO_IPIP,
1918 					   RT_TOS(iph->tos), vif->link);
1919 		if (IS_ERR(rt))
1920 			goto out_free;
1921 		encap = sizeof(struct iphdr);
1922 	} else {
1923 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1924 					   0, 0,
1925 					   IPPROTO_IPIP,
1926 					   RT_TOS(iph->tos), vif->link);
1927 		if (IS_ERR(rt))
1928 			goto out_free;
1929 	}
1930 
1931 	dev = rt->dst.dev;
1932 
1933 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1934 		/* Do not fragment multicasts. Alas, IPv4 does not
1935 		 * allow to send ICMP, so that packets will disappear
1936 		 * to blackhole.
1937 		 */
1938 		IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
1939 		ip_rt_put(rt);
1940 		goto out_free;
1941 	}
1942 
1943 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1944 
1945 	if (skb_cow(skb, encap)) {
1946 		ip_rt_put(rt);
1947 		goto out_free;
1948 	}
1949 
1950 	vif->pkt_out++;
1951 	vif->bytes_out += skb->len;
1952 
1953 	skb_dst_drop(skb);
1954 	skb_dst_set(skb, &rt->dst);
1955 	ip_decrease_ttl(ip_hdr(skb));
1956 
1957 	/* FIXME: forward and output firewalls used to be called here.
1958 	 * What do we do with netfilter? -- RR
1959 	 */
1960 	if (vif->flags & VIFF_TUNNEL) {
1961 		ip_encap(net, skb, vif->local, vif->remote);
1962 		/* FIXME: extra output firewall step used to be here. --RR */
1963 		vif->dev->stats.tx_packets++;
1964 		vif->dev->stats.tx_bytes += skb->len;
1965 	}
1966 
1967 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1968 
1969 	/* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1970 	 * not only before forwarding, but after forwarding on all output
1971 	 * interfaces. It is clear, if mrouter runs a multicasting
1972 	 * program, it should receive packets not depending to what interface
1973 	 * program is joined.
1974 	 * If we will not make it, the program will have to join on all
1975 	 * interfaces. On the other hand, multihoming host (or router, but
1976 	 * not mrouter) cannot join to more than one interface - it will
1977 	 * result in receiving multiple packets.
1978 	 */
1979 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
1980 		net, NULL, skb, skb->dev, dev,
1981 		ipmr_forward_finish);
1982 	return;
1983 
1984 out_free:
1985 	kfree_skb(skb);
1986 }
1987 
1988 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1989 {
1990 	int ct;
1991 
1992 	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1993 		if (mrt->vif_table[ct].dev == dev)
1994 			break;
1995 	}
1996 	return ct;
1997 }
1998 
1999 /* "local" means that we should preserve one skb (for local delivery) */
2000 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
2001 			  struct net_device *dev, struct sk_buff *skb,
2002 			  struct mfc_cache *cache, int local)
2003 {
2004 	int true_vifi = ipmr_find_vif(mrt, dev);
2005 	int psend = -1;
2006 	int vif, ct;
2007 
2008 	vif = cache->mfc_parent;
2009 	cache->mfc_un.res.pkt++;
2010 	cache->mfc_un.res.bytes += skb->len;
2011 	cache->mfc_un.res.lastuse = jiffies;
2012 
2013 	if (cache->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
2014 		struct mfc_cache *cache_proxy;
2015 
2016 		/* For an (*,G) entry, we only check that the incomming
2017 		 * interface is part of the static tree.
2018 		 */
2019 		cache_proxy = ipmr_cache_find_any_parent(mrt, vif);
2020 		if (cache_proxy &&
2021 		    cache_proxy->mfc_un.res.ttls[true_vifi] < 255)
2022 			goto forward;
2023 	}
2024 
2025 	/* Wrong interface: drop packet and (maybe) send PIM assert. */
2026 	if (mrt->vif_table[vif].dev != dev) {
2027 		if (rt_is_output_route(skb_rtable(skb))) {
2028 			/* It is our own packet, looped back.
2029 			 * Very complicated situation...
2030 			 *
2031 			 * The best workaround until routing daemons will be
2032 			 * fixed is not to redistribute packet, if it was
2033 			 * send through wrong interface. It means, that
2034 			 * multicast applications WILL NOT work for
2035 			 * (S,G), which have default multicast route pointing
2036 			 * to wrong oif. In any case, it is not a good
2037 			 * idea to use multicasting applications on router.
2038 			 */
2039 			goto dont_forward;
2040 		}
2041 
2042 		cache->mfc_un.res.wrong_if++;
2043 
2044 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
2045 		    /* pimsm uses asserts, when switching from RPT to SPT,
2046 		     * so that we cannot check that packet arrived on an oif.
2047 		     * It is bad, but otherwise we would need to move pretty
2048 		     * large chunk of pimd to kernel. Ough... --ANK
2049 		     */
2050 		    (mrt->mroute_do_pim ||
2051 		     cache->mfc_un.res.ttls[true_vifi] < 255) &&
2052 		    time_after(jiffies,
2053 			       cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
2054 			cache->mfc_un.res.last_assert = jiffies;
2055 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
2056 		}
2057 		goto dont_forward;
2058 	}
2059 
2060 forward:
2061 	mrt->vif_table[vif].pkt_in++;
2062 	mrt->vif_table[vif].bytes_in += skb->len;
2063 
2064 	/* Forward the frame */
2065 	if (cache->mfc_origin == htonl(INADDR_ANY) &&
2066 	    cache->mfc_mcastgrp == htonl(INADDR_ANY)) {
2067 		if (true_vifi >= 0 &&
2068 		    true_vifi != cache->mfc_parent &&
2069 		    ip_hdr(skb)->ttl >
2070 				cache->mfc_un.res.ttls[cache->mfc_parent]) {
2071 			/* It's an (*,*) entry and the packet is not coming from
2072 			 * the upstream: forward the packet to the upstream
2073 			 * only.
2074 			 */
2075 			psend = cache->mfc_parent;
2076 			goto last_forward;
2077 		}
2078 		goto dont_forward;
2079 	}
2080 	for (ct = cache->mfc_un.res.maxvif - 1;
2081 	     ct >= cache->mfc_un.res.minvif; ct--) {
2082 		/* For (*,G) entry, don't forward to the incoming interface */
2083 		if ((cache->mfc_origin != htonl(INADDR_ANY) ||
2084 		     ct != true_vifi) &&
2085 		    ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
2086 			if (psend != -1) {
2087 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2088 
2089 				if (skb2)
2090 					ipmr_queue_xmit(net, mrt, true_vifi,
2091 							skb2, cache, psend);
2092 			}
2093 			psend = ct;
2094 		}
2095 	}
2096 last_forward:
2097 	if (psend != -1) {
2098 		if (local) {
2099 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2100 
2101 			if (skb2)
2102 				ipmr_queue_xmit(net, mrt, true_vifi, skb2,
2103 						cache, psend);
2104 		} else {
2105 			ipmr_queue_xmit(net, mrt, true_vifi, skb, cache, psend);
2106 			return;
2107 		}
2108 	}
2109 
2110 dont_forward:
2111 	if (!local)
2112 		kfree_skb(skb);
2113 }
2114 
2115 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
2116 {
2117 	struct rtable *rt = skb_rtable(skb);
2118 	struct iphdr *iph = ip_hdr(skb);
2119 	struct flowi4 fl4 = {
2120 		.daddr = iph->daddr,
2121 		.saddr = iph->saddr,
2122 		.flowi4_tos = RT_TOS(iph->tos),
2123 		.flowi4_oif = (rt_is_output_route(rt) ?
2124 			       skb->dev->ifindex : 0),
2125 		.flowi4_iif = (rt_is_output_route(rt) ?
2126 			       LOOPBACK_IFINDEX :
2127 			       skb->dev->ifindex),
2128 		.flowi4_mark = skb->mark,
2129 	};
2130 	struct mr_table *mrt;
2131 	int err;
2132 
2133 	err = ipmr_fib_lookup(net, &fl4, &mrt);
2134 	if (err)
2135 		return ERR_PTR(err);
2136 	return mrt;
2137 }
2138 
2139 /* Multicast packets for forwarding arrive here
2140  * Called with rcu_read_lock();
2141  */
2142 int ip_mr_input(struct sk_buff *skb)
2143 {
2144 	struct mfc_cache *cache;
2145 	struct net *net = dev_net(skb->dev);
2146 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
2147 	struct mr_table *mrt;
2148 	struct net_device *dev;
2149 
2150 	/* skb->dev passed in is the loX master dev for vrfs.
2151 	 * As there are no vifs associated with loopback devices,
2152 	 * get the proper interface that does have a vif associated with it.
2153 	 */
2154 	dev = skb->dev;
2155 	if (netif_is_l3_master(skb->dev)) {
2156 		dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
2157 		if (!dev) {
2158 			kfree_skb(skb);
2159 			return -ENODEV;
2160 		}
2161 	}
2162 
2163 	/* Packet is looped back after forward, it should not be
2164 	 * forwarded second time, but still can be delivered locally.
2165 	 */
2166 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
2167 		goto dont_forward;
2168 
2169 	mrt = ipmr_rt_fib_lookup(net, skb);
2170 	if (IS_ERR(mrt)) {
2171 		kfree_skb(skb);
2172 		return PTR_ERR(mrt);
2173 	}
2174 	if (!local) {
2175 		if (IPCB(skb)->opt.router_alert) {
2176 			if (ip_call_ra_chain(skb))
2177 				return 0;
2178 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
2179 			/* IGMPv1 (and broken IGMPv2 implementations sort of
2180 			 * Cisco IOS <= 11.2(8)) do not put router alert
2181 			 * option to IGMP packets destined to routable
2182 			 * groups. It is very bad, because it means
2183 			 * that we can forward NO IGMP messages.
2184 			 */
2185 			struct sock *mroute_sk;
2186 
2187 			mroute_sk = rcu_dereference(mrt->mroute_sk);
2188 			if (mroute_sk) {
2189 				nf_reset(skb);
2190 				raw_rcv(mroute_sk, skb);
2191 				return 0;
2192 			}
2193 		    }
2194 	}
2195 
2196 	/* already under rcu_read_lock() */
2197 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
2198 	if (!cache) {
2199 		int vif = ipmr_find_vif(mrt, dev);
2200 
2201 		if (vif >= 0)
2202 			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
2203 						    vif);
2204 	}
2205 
2206 	/* No usable cache entry */
2207 	if (!cache) {
2208 		int vif;
2209 
2210 		if (local) {
2211 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2212 			ip_local_deliver(skb);
2213 			if (!skb2)
2214 				return -ENOBUFS;
2215 			skb = skb2;
2216 		}
2217 
2218 		read_lock(&mrt_lock);
2219 		vif = ipmr_find_vif(mrt, dev);
2220 		if (vif >= 0) {
2221 			int err2 = ipmr_cache_unresolved(mrt, vif, skb, dev);
2222 			read_unlock(&mrt_lock);
2223 
2224 			return err2;
2225 		}
2226 		read_unlock(&mrt_lock);
2227 		kfree_skb(skb);
2228 		return -ENODEV;
2229 	}
2230 
2231 	read_lock(&mrt_lock);
2232 	ip_mr_forward(net, mrt, dev, skb, cache, local);
2233 	read_unlock(&mrt_lock);
2234 
2235 	if (local)
2236 		return ip_local_deliver(skb);
2237 
2238 	return 0;
2239 
2240 dont_forward:
2241 	if (local)
2242 		return ip_local_deliver(skb);
2243 	kfree_skb(skb);
2244 	return 0;
2245 }
2246 
2247 #ifdef CONFIG_IP_PIMSM_V1
2248 /* Handle IGMP messages of PIMv1 */
2249 int pim_rcv_v1(struct sk_buff *skb)
2250 {
2251 	struct igmphdr *pim;
2252 	struct net *net = dev_net(skb->dev);
2253 	struct mr_table *mrt;
2254 
2255 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2256 		goto drop;
2257 
2258 	pim = igmp_hdr(skb);
2259 
2260 	mrt = ipmr_rt_fib_lookup(net, skb);
2261 	if (IS_ERR(mrt))
2262 		goto drop;
2263 	if (!mrt->mroute_do_pim ||
2264 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2265 		goto drop;
2266 
2267 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2268 drop:
2269 		kfree_skb(skb);
2270 	}
2271 	return 0;
2272 }
2273 #endif
2274 
2275 #ifdef CONFIG_IP_PIMSM_V2
2276 static int pim_rcv(struct sk_buff *skb)
2277 {
2278 	struct pimreghdr *pim;
2279 	struct net *net = dev_net(skb->dev);
2280 	struct mr_table *mrt;
2281 
2282 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2283 		goto drop;
2284 
2285 	pim = (struct pimreghdr *)skb_transport_header(skb);
2286 	if (pim->type != ((PIM_VERSION << 4) | (PIM_TYPE_REGISTER)) ||
2287 	    (pim->flags & PIM_NULL_REGISTER) ||
2288 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2289 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2290 		goto drop;
2291 
2292 	mrt = ipmr_rt_fib_lookup(net, skb);
2293 	if (IS_ERR(mrt))
2294 		goto drop;
2295 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2296 drop:
2297 		kfree_skb(skb);
2298 	}
2299 	return 0;
2300 }
2301 #endif
2302 
2303 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2304 			      struct mfc_cache *c, struct rtmsg *rtm)
2305 {
2306 	struct rta_mfc_stats mfcs;
2307 	struct nlattr *mp_attr;
2308 	struct rtnexthop *nhp;
2309 	unsigned long lastuse;
2310 	int ct;
2311 
2312 	/* If cache is unresolved, don't try to parse IIF and OIF */
2313 	if (c->mfc_parent >= MAXVIFS) {
2314 		rtm->rtm_flags |= RTNH_F_UNRESOLVED;
2315 		return -ENOENT;
2316 	}
2317 
2318 	if (VIF_EXISTS(mrt, c->mfc_parent) &&
2319 	    nla_put_u32(skb, RTA_IIF, mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
2320 		return -EMSGSIZE;
2321 
2322 	if (c->mfc_flags & MFC_OFFLOAD)
2323 		rtm->rtm_flags |= RTNH_F_OFFLOAD;
2324 
2325 	if (!(mp_attr = nla_nest_start(skb, RTA_MULTIPATH)))
2326 		return -EMSGSIZE;
2327 
2328 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
2329 		if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
2330 			if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp)))) {
2331 				nla_nest_cancel(skb, mp_attr);
2332 				return -EMSGSIZE;
2333 			}
2334 
2335 			nhp->rtnh_flags = 0;
2336 			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
2337 			nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
2338 			nhp->rtnh_len = sizeof(*nhp);
2339 		}
2340 	}
2341 
2342 	nla_nest_end(skb, mp_attr);
2343 
2344 	lastuse = READ_ONCE(c->mfc_un.res.lastuse);
2345 	lastuse = time_after_eq(jiffies, lastuse) ? jiffies - lastuse : 0;
2346 
2347 	mfcs.mfcs_packets = c->mfc_un.res.pkt;
2348 	mfcs.mfcs_bytes = c->mfc_un.res.bytes;
2349 	mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
2350 	if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) ||
2351 	    nla_put_u64_64bit(skb, RTA_EXPIRES, jiffies_to_clock_t(lastuse),
2352 			      RTA_PAD))
2353 		return -EMSGSIZE;
2354 
2355 	rtm->rtm_type = RTN_MULTICAST;
2356 	return 1;
2357 }
2358 
2359 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2360 		   __be32 saddr, __be32 daddr,
2361 		   struct rtmsg *rtm, u32 portid)
2362 {
2363 	struct mfc_cache *cache;
2364 	struct mr_table *mrt;
2365 	int err;
2366 
2367 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2368 	if (!mrt)
2369 		return -ENOENT;
2370 
2371 	rcu_read_lock();
2372 	cache = ipmr_cache_find(mrt, saddr, daddr);
2373 	if (!cache && skb->dev) {
2374 		int vif = ipmr_find_vif(mrt, skb->dev);
2375 
2376 		if (vif >= 0)
2377 			cache = ipmr_cache_find_any(mrt, daddr, vif);
2378 	}
2379 	if (!cache) {
2380 		struct sk_buff *skb2;
2381 		struct iphdr *iph;
2382 		struct net_device *dev;
2383 		int vif = -1;
2384 
2385 		dev = skb->dev;
2386 		read_lock(&mrt_lock);
2387 		if (dev)
2388 			vif = ipmr_find_vif(mrt, dev);
2389 		if (vif < 0) {
2390 			read_unlock(&mrt_lock);
2391 			rcu_read_unlock();
2392 			return -ENODEV;
2393 		}
2394 		skb2 = skb_clone(skb, GFP_ATOMIC);
2395 		if (!skb2) {
2396 			read_unlock(&mrt_lock);
2397 			rcu_read_unlock();
2398 			return -ENOMEM;
2399 		}
2400 
2401 		NETLINK_CB(skb2).portid = portid;
2402 		skb_push(skb2, sizeof(struct iphdr));
2403 		skb_reset_network_header(skb2);
2404 		iph = ip_hdr(skb2);
2405 		iph->ihl = sizeof(struct iphdr) >> 2;
2406 		iph->saddr = saddr;
2407 		iph->daddr = daddr;
2408 		iph->version = 0;
2409 		err = ipmr_cache_unresolved(mrt, vif, skb2, dev);
2410 		read_unlock(&mrt_lock);
2411 		rcu_read_unlock();
2412 		return err;
2413 	}
2414 
2415 	read_lock(&mrt_lock);
2416 	err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2417 	read_unlock(&mrt_lock);
2418 	rcu_read_unlock();
2419 	return err;
2420 }
2421 
2422 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2423 			    u32 portid, u32 seq, struct mfc_cache *c, int cmd,
2424 			    int flags)
2425 {
2426 	struct nlmsghdr *nlh;
2427 	struct rtmsg *rtm;
2428 	int err;
2429 
2430 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2431 	if (!nlh)
2432 		return -EMSGSIZE;
2433 
2434 	rtm = nlmsg_data(nlh);
2435 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2436 	rtm->rtm_dst_len  = 32;
2437 	rtm->rtm_src_len  = 32;
2438 	rtm->rtm_tos      = 0;
2439 	rtm->rtm_table    = mrt->id;
2440 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2441 		goto nla_put_failure;
2442 	rtm->rtm_type     = RTN_MULTICAST;
2443 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2444 	if (c->mfc_flags & MFC_STATIC)
2445 		rtm->rtm_protocol = RTPROT_STATIC;
2446 	else
2447 		rtm->rtm_protocol = RTPROT_MROUTED;
2448 	rtm->rtm_flags    = 0;
2449 
2450 	if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
2451 	    nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
2452 		goto nla_put_failure;
2453 	err = __ipmr_fill_mroute(mrt, skb, c, rtm);
2454 	/* do not break the dump if cache is unresolved */
2455 	if (err < 0 && err != -ENOENT)
2456 		goto nla_put_failure;
2457 
2458 	nlmsg_end(skb, nlh);
2459 	return 0;
2460 
2461 nla_put_failure:
2462 	nlmsg_cancel(skb, nlh);
2463 	return -EMSGSIZE;
2464 }
2465 
2466 static size_t mroute_msgsize(bool unresolved, int maxvif)
2467 {
2468 	size_t len =
2469 		NLMSG_ALIGN(sizeof(struct rtmsg))
2470 		+ nla_total_size(4)	/* RTA_TABLE */
2471 		+ nla_total_size(4)	/* RTA_SRC */
2472 		+ nla_total_size(4)	/* RTA_DST */
2473 		;
2474 
2475 	if (!unresolved)
2476 		len = len
2477 		      + nla_total_size(4)	/* RTA_IIF */
2478 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2479 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2480 						/* RTA_MFC_STATS */
2481 		      + nla_total_size_64bit(sizeof(struct rta_mfc_stats))
2482 		;
2483 
2484 	return len;
2485 }
2486 
2487 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2488 				 int cmd)
2489 {
2490 	struct net *net = read_pnet(&mrt->net);
2491 	struct sk_buff *skb;
2492 	int err = -ENOBUFS;
2493 
2494 	skb = nlmsg_new(mroute_msgsize(mfc->mfc_parent >= MAXVIFS, mrt->maxvif),
2495 			GFP_ATOMIC);
2496 	if (!skb)
2497 		goto errout;
2498 
2499 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2500 	if (err < 0)
2501 		goto errout;
2502 
2503 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2504 	return;
2505 
2506 errout:
2507 	kfree_skb(skb);
2508 	if (err < 0)
2509 		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2510 }
2511 
2512 static size_t igmpmsg_netlink_msgsize(size_t payloadlen)
2513 {
2514 	size_t len =
2515 		NLMSG_ALIGN(sizeof(struct rtgenmsg))
2516 		+ nla_total_size(1)	/* IPMRA_CREPORT_MSGTYPE */
2517 		+ nla_total_size(4)	/* IPMRA_CREPORT_VIF_ID */
2518 		+ nla_total_size(4)	/* IPMRA_CREPORT_SRC_ADDR */
2519 		+ nla_total_size(4)	/* IPMRA_CREPORT_DST_ADDR */
2520 					/* IPMRA_CREPORT_PKT */
2521 		+ nla_total_size(payloadlen)
2522 		;
2523 
2524 	return len;
2525 }
2526 
2527 static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt)
2528 {
2529 	struct net *net = read_pnet(&mrt->net);
2530 	struct nlmsghdr *nlh;
2531 	struct rtgenmsg *rtgenm;
2532 	struct igmpmsg *msg;
2533 	struct sk_buff *skb;
2534 	struct nlattr *nla;
2535 	int payloadlen;
2536 
2537 	payloadlen = pkt->len - sizeof(struct igmpmsg);
2538 	msg = (struct igmpmsg *)skb_network_header(pkt);
2539 
2540 	skb = nlmsg_new(igmpmsg_netlink_msgsize(payloadlen), GFP_ATOMIC);
2541 	if (!skb)
2542 		goto errout;
2543 
2544 	nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT,
2545 			sizeof(struct rtgenmsg), 0);
2546 	if (!nlh)
2547 		goto errout;
2548 	rtgenm = nlmsg_data(nlh);
2549 	rtgenm->rtgen_family = RTNL_FAMILY_IPMR;
2550 	if (nla_put_u8(skb, IPMRA_CREPORT_MSGTYPE, msg->im_msgtype) ||
2551 	    nla_put_u32(skb, IPMRA_CREPORT_VIF_ID, msg->im_vif) ||
2552 	    nla_put_in_addr(skb, IPMRA_CREPORT_SRC_ADDR,
2553 			    msg->im_src.s_addr) ||
2554 	    nla_put_in_addr(skb, IPMRA_CREPORT_DST_ADDR,
2555 			    msg->im_dst.s_addr))
2556 		goto nla_put_failure;
2557 
2558 	nla = nla_reserve(skb, IPMRA_CREPORT_PKT, payloadlen);
2559 	if (!nla || skb_copy_bits(pkt, sizeof(struct igmpmsg),
2560 				  nla_data(nla), payloadlen))
2561 		goto nla_put_failure;
2562 
2563 	nlmsg_end(skb, nlh);
2564 
2565 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE_R, NULL, GFP_ATOMIC);
2566 	return;
2567 
2568 nla_put_failure:
2569 	nlmsg_cancel(skb, nlh);
2570 errout:
2571 	kfree_skb(skb);
2572 	rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE_R, -ENOBUFS);
2573 }
2574 
2575 static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2576 			     struct netlink_ext_ack *extack)
2577 {
2578 	struct net *net = sock_net(in_skb->sk);
2579 	struct nlattr *tb[RTA_MAX + 1];
2580 	struct sk_buff *skb = NULL;
2581 	struct mfc_cache *cache;
2582 	struct mr_table *mrt;
2583 	struct rtmsg *rtm;
2584 	__be32 src, grp;
2585 	u32 tableid;
2586 	int err;
2587 
2588 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX,
2589 			  rtm_ipv4_policy, extack);
2590 	if (err < 0)
2591 		goto errout;
2592 
2593 	rtm = nlmsg_data(nlh);
2594 
2595 	src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2596 	grp = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2597 	tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0;
2598 
2599 	mrt = ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT);
2600 	if (!mrt) {
2601 		err = -ENOENT;
2602 		goto errout_free;
2603 	}
2604 
2605 	/* entries are added/deleted only under RTNL */
2606 	rcu_read_lock();
2607 	cache = ipmr_cache_find(mrt, src, grp);
2608 	rcu_read_unlock();
2609 	if (!cache) {
2610 		err = -ENOENT;
2611 		goto errout_free;
2612 	}
2613 
2614 	skb = nlmsg_new(mroute_msgsize(false, mrt->maxvif), GFP_KERNEL);
2615 	if (!skb) {
2616 		err = -ENOBUFS;
2617 		goto errout_free;
2618 	}
2619 
2620 	err = ipmr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid,
2621 			       nlh->nlmsg_seq, cache,
2622 			       RTM_NEWROUTE, 0);
2623 	if (err < 0)
2624 		goto errout_free;
2625 
2626 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2627 
2628 errout:
2629 	return err;
2630 
2631 errout_free:
2632 	kfree_skb(skb);
2633 	goto errout;
2634 }
2635 
2636 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2637 {
2638 	struct net *net = sock_net(skb->sk);
2639 	struct mr_table *mrt;
2640 	struct mfc_cache *mfc;
2641 	unsigned int t = 0, s_t;
2642 	unsigned int e = 0, s_e;
2643 
2644 	s_t = cb->args[0];
2645 	s_e = cb->args[1];
2646 
2647 	rcu_read_lock();
2648 	ipmr_for_each_table(mrt, net) {
2649 		if (t < s_t)
2650 			goto next_table;
2651 		list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) {
2652 			if (e < s_e)
2653 				goto next_entry;
2654 			if (ipmr_fill_mroute(mrt, skb,
2655 					     NETLINK_CB(cb->skb).portid,
2656 					     cb->nlh->nlmsg_seq,
2657 					     mfc, RTM_NEWROUTE,
2658 					     NLM_F_MULTI) < 0)
2659 				goto done;
2660 next_entry:
2661 			e++;
2662 		}
2663 		e = 0;
2664 		s_e = 0;
2665 
2666 		spin_lock_bh(&mfc_unres_lock);
2667 		list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
2668 			if (e < s_e)
2669 				goto next_entry2;
2670 			if (ipmr_fill_mroute(mrt, skb,
2671 					     NETLINK_CB(cb->skb).portid,
2672 					     cb->nlh->nlmsg_seq,
2673 					     mfc, RTM_NEWROUTE,
2674 					     NLM_F_MULTI) < 0) {
2675 				spin_unlock_bh(&mfc_unres_lock);
2676 				goto done;
2677 			}
2678 next_entry2:
2679 			e++;
2680 		}
2681 		spin_unlock_bh(&mfc_unres_lock);
2682 		e = 0;
2683 		s_e = 0;
2684 next_table:
2685 		t++;
2686 	}
2687 done:
2688 	rcu_read_unlock();
2689 
2690 	cb->args[1] = e;
2691 	cb->args[0] = t;
2692 
2693 	return skb->len;
2694 }
2695 
2696 static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {
2697 	[RTA_SRC]	= { .type = NLA_U32 },
2698 	[RTA_DST]	= { .type = NLA_U32 },
2699 	[RTA_IIF]	= { .type = NLA_U32 },
2700 	[RTA_TABLE]	= { .type = NLA_U32 },
2701 	[RTA_MULTIPATH]	= { .len = sizeof(struct rtnexthop) },
2702 };
2703 
2704 static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol)
2705 {
2706 	switch (rtm_protocol) {
2707 	case RTPROT_STATIC:
2708 	case RTPROT_MROUTED:
2709 		return true;
2710 	}
2711 	return false;
2712 }
2713 
2714 static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc)
2715 {
2716 	struct rtnexthop *rtnh = nla_data(nla);
2717 	int remaining = nla_len(nla), vifi = 0;
2718 
2719 	while (rtnh_ok(rtnh, remaining)) {
2720 		mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops;
2721 		if (++vifi == MAXVIFS)
2722 			break;
2723 		rtnh = rtnh_next(rtnh, &remaining);
2724 	}
2725 
2726 	return remaining > 0 ? -EINVAL : vifi;
2727 }
2728 
2729 /* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */
2730 static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
2731 			    struct mfcctl *mfcc, int *mrtsock,
2732 			    struct mr_table **mrtret,
2733 			    struct netlink_ext_ack *extack)
2734 {
2735 	struct net_device *dev = NULL;
2736 	u32 tblid = RT_TABLE_DEFAULT;
2737 	struct mr_table *mrt;
2738 	struct nlattr *attr;
2739 	struct rtmsg *rtm;
2740 	int ret, rem;
2741 
2742 	ret = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipmr_policy,
2743 			     extack);
2744 	if (ret < 0)
2745 		goto out;
2746 	rtm = nlmsg_data(nlh);
2747 
2748 	ret = -EINVAL;
2749 	if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 ||
2750 	    rtm->rtm_type != RTN_MULTICAST ||
2751 	    rtm->rtm_scope != RT_SCOPE_UNIVERSE ||
2752 	    !ipmr_rtm_validate_proto(rtm->rtm_protocol))
2753 		goto out;
2754 
2755 	memset(mfcc, 0, sizeof(*mfcc));
2756 	mfcc->mfcc_parent = -1;
2757 	ret = 0;
2758 	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) {
2759 		switch (nla_type(attr)) {
2760 		case RTA_SRC:
2761 			mfcc->mfcc_origin.s_addr = nla_get_be32(attr);
2762 			break;
2763 		case RTA_DST:
2764 			mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr);
2765 			break;
2766 		case RTA_IIF:
2767 			dev = __dev_get_by_index(net, nla_get_u32(attr));
2768 			if (!dev) {
2769 				ret = -ENODEV;
2770 				goto out;
2771 			}
2772 			break;
2773 		case RTA_MULTIPATH:
2774 			if (ipmr_nla_get_ttls(attr, mfcc) < 0) {
2775 				ret = -EINVAL;
2776 				goto out;
2777 			}
2778 			break;
2779 		case RTA_PREFSRC:
2780 			ret = 1;
2781 			break;
2782 		case RTA_TABLE:
2783 			tblid = nla_get_u32(attr);
2784 			break;
2785 		}
2786 	}
2787 	mrt = ipmr_get_table(net, tblid);
2788 	if (!mrt) {
2789 		ret = -ENOENT;
2790 		goto out;
2791 	}
2792 	*mrtret = mrt;
2793 	*mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0;
2794 	if (dev)
2795 		mfcc->mfcc_parent = ipmr_find_vif(mrt, dev);
2796 
2797 out:
2798 	return ret;
2799 }
2800 
2801 /* takes care of both newroute and delroute */
2802 static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh,
2803 			  struct netlink_ext_ack *extack)
2804 {
2805 	struct net *net = sock_net(skb->sk);
2806 	int ret, mrtsock, parent;
2807 	struct mr_table *tbl;
2808 	struct mfcctl mfcc;
2809 
2810 	mrtsock = 0;
2811 	tbl = NULL;
2812 	ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl, extack);
2813 	if (ret < 0)
2814 		return ret;
2815 
2816 	parent = ret ? mfcc.mfcc_parent : -1;
2817 	if (nlh->nlmsg_type == RTM_NEWROUTE)
2818 		return ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent);
2819 	else
2820 		return ipmr_mfc_delete(tbl, &mfcc, parent);
2821 }
2822 
2823 static bool ipmr_fill_table(struct mr_table *mrt, struct sk_buff *skb)
2824 {
2825 	u32 queue_len = atomic_read(&mrt->cache_resolve_queue_len);
2826 
2827 	if (nla_put_u32(skb, IPMRA_TABLE_ID, mrt->id) ||
2828 	    nla_put_u32(skb, IPMRA_TABLE_CACHE_RES_QUEUE_LEN, queue_len) ||
2829 	    nla_put_s32(skb, IPMRA_TABLE_MROUTE_REG_VIF_NUM,
2830 			mrt->mroute_reg_vif_num) ||
2831 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_ASSERT,
2832 		       mrt->mroute_do_assert) ||
2833 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_PIM, mrt->mroute_do_pim))
2834 		return false;
2835 
2836 	return true;
2837 }
2838 
2839 static bool ipmr_fill_vif(struct mr_table *mrt, u32 vifid, struct sk_buff *skb)
2840 {
2841 	struct nlattr *vif_nest;
2842 	struct vif_device *vif;
2843 
2844 	/* if the VIF doesn't exist just continue */
2845 	if (!VIF_EXISTS(mrt, vifid))
2846 		return true;
2847 
2848 	vif = &mrt->vif_table[vifid];
2849 	vif_nest = nla_nest_start(skb, IPMRA_VIF);
2850 	if (!vif_nest)
2851 		return false;
2852 	if (nla_put_u32(skb, IPMRA_VIFA_IFINDEX, vif->dev->ifindex) ||
2853 	    nla_put_u32(skb, IPMRA_VIFA_VIF_ID, vifid) ||
2854 	    nla_put_u16(skb, IPMRA_VIFA_FLAGS, vif->flags) ||
2855 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_IN, vif->bytes_in,
2856 			      IPMRA_VIFA_PAD) ||
2857 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_OUT, vif->bytes_out,
2858 			      IPMRA_VIFA_PAD) ||
2859 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_IN, vif->pkt_in,
2860 			      IPMRA_VIFA_PAD) ||
2861 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_OUT, vif->pkt_out,
2862 			      IPMRA_VIFA_PAD) ||
2863 	    nla_put_be32(skb, IPMRA_VIFA_LOCAL_ADDR, vif->local) ||
2864 	    nla_put_be32(skb, IPMRA_VIFA_REMOTE_ADDR, vif->remote)) {
2865 		nla_nest_cancel(skb, vif_nest);
2866 		return false;
2867 	}
2868 	nla_nest_end(skb, vif_nest);
2869 
2870 	return true;
2871 }
2872 
2873 static int ipmr_rtm_dumplink(struct sk_buff *skb, struct netlink_callback *cb)
2874 {
2875 	struct net *net = sock_net(skb->sk);
2876 	struct nlmsghdr *nlh = NULL;
2877 	unsigned int t = 0, s_t;
2878 	unsigned int e = 0, s_e;
2879 	struct mr_table *mrt;
2880 
2881 	s_t = cb->args[0];
2882 	s_e = cb->args[1];
2883 
2884 	ipmr_for_each_table(mrt, net) {
2885 		struct nlattr *vifs, *af;
2886 		struct ifinfomsg *hdr;
2887 		u32 i;
2888 
2889 		if (t < s_t)
2890 			goto skip_table;
2891 		nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
2892 				cb->nlh->nlmsg_seq, RTM_NEWLINK,
2893 				sizeof(*hdr), NLM_F_MULTI);
2894 		if (!nlh)
2895 			break;
2896 
2897 		hdr = nlmsg_data(nlh);
2898 		memset(hdr, 0, sizeof(*hdr));
2899 		hdr->ifi_family = RTNL_FAMILY_IPMR;
2900 
2901 		af = nla_nest_start(skb, IFLA_AF_SPEC);
2902 		if (!af) {
2903 			nlmsg_cancel(skb, nlh);
2904 			goto out;
2905 		}
2906 
2907 		if (!ipmr_fill_table(mrt, skb)) {
2908 			nlmsg_cancel(skb, nlh);
2909 			goto out;
2910 		}
2911 
2912 		vifs = nla_nest_start(skb, IPMRA_TABLE_VIFS);
2913 		if (!vifs) {
2914 			nla_nest_end(skb, af);
2915 			nlmsg_end(skb, nlh);
2916 			goto out;
2917 		}
2918 		for (i = 0; i < mrt->maxvif; i++) {
2919 			if (e < s_e)
2920 				goto skip_entry;
2921 			if (!ipmr_fill_vif(mrt, i, skb)) {
2922 				nla_nest_end(skb, vifs);
2923 				nla_nest_end(skb, af);
2924 				nlmsg_end(skb, nlh);
2925 				goto out;
2926 			}
2927 skip_entry:
2928 			e++;
2929 		}
2930 		s_e = 0;
2931 		e = 0;
2932 		nla_nest_end(skb, vifs);
2933 		nla_nest_end(skb, af);
2934 		nlmsg_end(skb, nlh);
2935 skip_table:
2936 		t++;
2937 	}
2938 
2939 out:
2940 	cb->args[1] = e;
2941 	cb->args[0] = t;
2942 
2943 	return skb->len;
2944 }
2945 
2946 #ifdef CONFIG_PROC_FS
2947 /* The /proc interfaces to multicast routing :
2948  * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2949  */
2950 struct ipmr_vif_iter {
2951 	struct seq_net_private p;
2952 	struct mr_table *mrt;
2953 	int ct;
2954 };
2955 
2956 static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2957 					   struct ipmr_vif_iter *iter,
2958 					   loff_t pos)
2959 {
2960 	struct mr_table *mrt = iter->mrt;
2961 
2962 	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2963 		if (!VIF_EXISTS(mrt, iter->ct))
2964 			continue;
2965 		if (pos-- == 0)
2966 			return &mrt->vif_table[iter->ct];
2967 	}
2968 	return NULL;
2969 }
2970 
2971 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2972 	__acquires(mrt_lock)
2973 {
2974 	struct ipmr_vif_iter *iter = seq->private;
2975 	struct net *net = seq_file_net(seq);
2976 	struct mr_table *mrt;
2977 
2978 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2979 	if (!mrt)
2980 		return ERR_PTR(-ENOENT);
2981 
2982 	iter->mrt = mrt;
2983 
2984 	read_lock(&mrt_lock);
2985 	return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2986 		: SEQ_START_TOKEN;
2987 }
2988 
2989 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2990 {
2991 	struct ipmr_vif_iter *iter = seq->private;
2992 	struct net *net = seq_file_net(seq);
2993 	struct mr_table *mrt = iter->mrt;
2994 
2995 	++*pos;
2996 	if (v == SEQ_START_TOKEN)
2997 		return ipmr_vif_seq_idx(net, iter, 0);
2998 
2999 	while (++iter->ct < mrt->maxvif) {
3000 		if (!VIF_EXISTS(mrt, iter->ct))
3001 			continue;
3002 		return &mrt->vif_table[iter->ct];
3003 	}
3004 	return NULL;
3005 }
3006 
3007 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
3008 	__releases(mrt_lock)
3009 {
3010 	read_unlock(&mrt_lock);
3011 }
3012 
3013 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
3014 {
3015 	struct ipmr_vif_iter *iter = seq->private;
3016 	struct mr_table *mrt = iter->mrt;
3017 
3018 	if (v == SEQ_START_TOKEN) {
3019 		seq_puts(seq,
3020 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
3021 	} else {
3022 		const struct vif_device *vif = v;
3023 		const char *name =  vif->dev ? vif->dev->name : "none";
3024 
3025 		seq_printf(seq,
3026 			   "%2zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
3027 			   vif - mrt->vif_table,
3028 			   name, vif->bytes_in, vif->pkt_in,
3029 			   vif->bytes_out, vif->pkt_out,
3030 			   vif->flags, vif->local, vif->remote);
3031 	}
3032 	return 0;
3033 }
3034 
3035 static const struct seq_operations ipmr_vif_seq_ops = {
3036 	.start = ipmr_vif_seq_start,
3037 	.next  = ipmr_vif_seq_next,
3038 	.stop  = ipmr_vif_seq_stop,
3039 	.show  = ipmr_vif_seq_show,
3040 };
3041 
3042 static int ipmr_vif_open(struct inode *inode, struct file *file)
3043 {
3044 	return seq_open_net(inode, file, &ipmr_vif_seq_ops,
3045 			    sizeof(struct ipmr_vif_iter));
3046 }
3047 
3048 static const struct file_operations ipmr_vif_fops = {
3049 	.owner	 = THIS_MODULE,
3050 	.open    = ipmr_vif_open,
3051 	.read    = seq_read,
3052 	.llseek  = seq_lseek,
3053 	.release = seq_release_net,
3054 };
3055 
3056 struct ipmr_mfc_iter {
3057 	struct seq_net_private p;
3058 	struct mr_table *mrt;
3059 	struct list_head *cache;
3060 };
3061 
3062 static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
3063 					  struct ipmr_mfc_iter *it, loff_t pos)
3064 {
3065 	struct mr_table *mrt = it->mrt;
3066 	struct mfc_cache *mfc;
3067 
3068 	rcu_read_lock();
3069 	it->cache = &mrt->mfc_cache_list;
3070 	list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list)
3071 		if (pos-- == 0)
3072 			return mfc;
3073 	rcu_read_unlock();
3074 
3075 	spin_lock_bh(&mfc_unres_lock);
3076 	it->cache = &mrt->mfc_unres_queue;
3077 	list_for_each_entry(mfc, it->cache, list)
3078 		if (pos-- == 0)
3079 			return mfc;
3080 	spin_unlock_bh(&mfc_unres_lock);
3081 
3082 	it->cache = NULL;
3083 	return NULL;
3084 }
3085 
3086 
3087 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
3088 {
3089 	struct ipmr_mfc_iter *it = seq->private;
3090 	struct net *net = seq_file_net(seq);
3091 	struct mr_table *mrt;
3092 
3093 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
3094 	if (!mrt)
3095 		return ERR_PTR(-ENOENT);
3096 
3097 	it->mrt = mrt;
3098 	it->cache = NULL;
3099 	return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
3100 		: SEQ_START_TOKEN;
3101 }
3102 
3103 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3104 {
3105 	struct ipmr_mfc_iter *it = seq->private;
3106 	struct net *net = seq_file_net(seq);
3107 	struct mr_table *mrt = it->mrt;
3108 	struct mfc_cache *mfc = v;
3109 
3110 	++*pos;
3111 
3112 	if (v == SEQ_START_TOKEN)
3113 		return ipmr_mfc_seq_idx(net, seq->private, 0);
3114 
3115 	if (mfc->list.next != it->cache)
3116 		return list_entry(mfc->list.next, struct mfc_cache, list);
3117 
3118 	if (it->cache == &mrt->mfc_unres_queue)
3119 		goto end_of_list;
3120 
3121 	/* exhausted cache_array, show unresolved */
3122 	rcu_read_unlock();
3123 	it->cache = &mrt->mfc_unres_queue;
3124 
3125 	spin_lock_bh(&mfc_unres_lock);
3126 	if (!list_empty(it->cache))
3127 		return list_first_entry(it->cache, struct mfc_cache, list);
3128 
3129 end_of_list:
3130 	spin_unlock_bh(&mfc_unres_lock);
3131 	it->cache = NULL;
3132 
3133 	return NULL;
3134 }
3135 
3136 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
3137 {
3138 	struct ipmr_mfc_iter *it = seq->private;
3139 	struct mr_table *mrt = it->mrt;
3140 
3141 	if (it->cache == &mrt->mfc_unres_queue)
3142 		spin_unlock_bh(&mfc_unres_lock);
3143 	else if (it->cache == &mrt->mfc_cache_list)
3144 		rcu_read_unlock();
3145 }
3146 
3147 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
3148 {
3149 	int n;
3150 
3151 	if (v == SEQ_START_TOKEN) {
3152 		seq_puts(seq,
3153 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
3154 	} else {
3155 		const struct mfc_cache *mfc = v;
3156 		const struct ipmr_mfc_iter *it = seq->private;
3157 		const struct mr_table *mrt = it->mrt;
3158 
3159 		seq_printf(seq, "%08X %08X %-3hd",
3160 			   (__force u32) mfc->mfc_mcastgrp,
3161 			   (__force u32) mfc->mfc_origin,
3162 			   mfc->mfc_parent);
3163 
3164 		if (it->cache != &mrt->mfc_unres_queue) {
3165 			seq_printf(seq, " %8lu %8lu %8lu",
3166 				   mfc->mfc_un.res.pkt,
3167 				   mfc->mfc_un.res.bytes,
3168 				   mfc->mfc_un.res.wrong_if);
3169 			for (n = mfc->mfc_un.res.minvif;
3170 			     n < mfc->mfc_un.res.maxvif; n++) {
3171 				if (VIF_EXISTS(mrt, n) &&
3172 				    mfc->mfc_un.res.ttls[n] < 255)
3173 					seq_printf(seq,
3174 					   " %2d:%-3d",
3175 					   n, mfc->mfc_un.res.ttls[n]);
3176 			}
3177 		} else {
3178 			/* unresolved mfc_caches don't contain
3179 			 * pkt, bytes and wrong_if values
3180 			 */
3181 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
3182 		}
3183 		seq_putc(seq, '\n');
3184 	}
3185 	return 0;
3186 }
3187 
3188 static const struct seq_operations ipmr_mfc_seq_ops = {
3189 	.start = ipmr_mfc_seq_start,
3190 	.next  = ipmr_mfc_seq_next,
3191 	.stop  = ipmr_mfc_seq_stop,
3192 	.show  = ipmr_mfc_seq_show,
3193 };
3194 
3195 static int ipmr_mfc_open(struct inode *inode, struct file *file)
3196 {
3197 	return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
3198 			    sizeof(struct ipmr_mfc_iter));
3199 }
3200 
3201 static const struct file_operations ipmr_mfc_fops = {
3202 	.owner	 = THIS_MODULE,
3203 	.open    = ipmr_mfc_open,
3204 	.read    = seq_read,
3205 	.llseek  = seq_lseek,
3206 	.release = seq_release_net,
3207 };
3208 #endif
3209 
3210 #ifdef CONFIG_IP_PIMSM_V2
3211 static const struct net_protocol pim_protocol = {
3212 	.handler	=	pim_rcv,
3213 	.netns_ok	=	1,
3214 };
3215 #endif
3216 
3217 static unsigned int ipmr_seq_read(struct net *net)
3218 {
3219 	ASSERT_RTNL();
3220 
3221 	return net->ipv4.ipmr_seq + ipmr_rules_seq_read(net);
3222 }
3223 
3224 static int ipmr_dump(struct net *net, struct notifier_block *nb)
3225 {
3226 	struct mr_table *mrt;
3227 	int err;
3228 
3229 	err = ipmr_rules_dump(net, nb);
3230 	if (err)
3231 		return err;
3232 
3233 	ipmr_for_each_table(mrt, net) {
3234 		struct vif_device *v = &mrt->vif_table[0];
3235 		struct mfc_cache *mfc;
3236 		int vifi;
3237 
3238 		/* Notifiy on table VIF entries */
3239 		read_lock(&mrt_lock);
3240 		for (vifi = 0; vifi < mrt->maxvif; vifi++, v++) {
3241 			if (!v->dev)
3242 				continue;
3243 
3244 			call_ipmr_vif_entry_notifier(nb, net, FIB_EVENT_VIF_ADD,
3245 						     v, vifi, mrt->id);
3246 		}
3247 		read_unlock(&mrt_lock);
3248 
3249 		/* Notify on table MFC entries */
3250 		list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list)
3251 			call_ipmr_mfc_entry_notifier(nb, net,
3252 						     FIB_EVENT_ENTRY_ADD, mfc,
3253 						     mrt->id);
3254 	}
3255 
3256 	return 0;
3257 }
3258 
3259 static const struct fib_notifier_ops ipmr_notifier_ops_template = {
3260 	.family		= RTNL_FAMILY_IPMR,
3261 	.fib_seq_read	= ipmr_seq_read,
3262 	.fib_dump	= ipmr_dump,
3263 	.owner		= THIS_MODULE,
3264 };
3265 
3266 static int __net_init ipmr_notifier_init(struct net *net)
3267 {
3268 	struct fib_notifier_ops *ops;
3269 
3270 	net->ipv4.ipmr_seq = 0;
3271 
3272 	ops = fib_notifier_ops_register(&ipmr_notifier_ops_template, net);
3273 	if (IS_ERR(ops))
3274 		return PTR_ERR(ops);
3275 	net->ipv4.ipmr_notifier_ops = ops;
3276 
3277 	return 0;
3278 }
3279 
3280 static void __net_exit ipmr_notifier_exit(struct net *net)
3281 {
3282 	fib_notifier_ops_unregister(net->ipv4.ipmr_notifier_ops);
3283 	net->ipv4.ipmr_notifier_ops = NULL;
3284 }
3285 
3286 /* Setup for IP multicast routing */
3287 static int __net_init ipmr_net_init(struct net *net)
3288 {
3289 	int err;
3290 
3291 	err = ipmr_notifier_init(net);
3292 	if (err)
3293 		goto ipmr_notifier_fail;
3294 
3295 	err = ipmr_rules_init(net);
3296 	if (err < 0)
3297 		goto ipmr_rules_fail;
3298 
3299 #ifdef CONFIG_PROC_FS
3300 	err = -ENOMEM;
3301 	if (!proc_create("ip_mr_vif", 0, net->proc_net, &ipmr_vif_fops))
3302 		goto proc_vif_fail;
3303 	if (!proc_create("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_fops))
3304 		goto proc_cache_fail;
3305 #endif
3306 	return 0;
3307 
3308 #ifdef CONFIG_PROC_FS
3309 proc_cache_fail:
3310 	remove_proc_entry("ip_mr_vif", net->proc_net);
3311 proc_vif_fail:
3312 	ipmr_rules_exit(net);
3313 #endif
3314 ipmr_rules_fail:
3315 	ipmr_notifier_exit(net);
3316 ipmr_notifier_fail:
3317 	return err;
3318 }
3319 
3320 static void __net_exit ipmr_net_exit(struct net *net)
3321 {
3322 #ifdef CONFIG_PROC_FS
3323 	remove_proc_entry("ip_mr_cache", net->proc_net);
3324 	remove_proc_entry("ip_mr_vif", net->proc_net);
3325 #endif
3326 	ipmr_notifier_exit(net);
3327 	ipmr_rules_exit(net);
3328 }
3329 
3330 static struct pernet_operations ipmr_net_ops = {
3331 	.init = ipmr_net_init,
3332 	.exit = ipmr_net_exit,
3333 };
3334 
3335 int __init ip_mr_init(void)
3336 {
3337 	int err;
3338 
3339 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
3340 				       sizeof(struct mfc_cache),
3341 				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
3342 				       NULL);
3343 
3344 	err = register_pernet_subsys(&ipmr_net_ops);
3345 	if (err)
3346 		goto reg_pernet_fail;
3347 
3348 	err = register_netdevice_notifier(&ip_mr_notifier);
3349 	if (err)
3350 		goto reg_notif_fail;
3351 #ifdef CONFIG_IP_PIMSM_V2
3352 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
3353 		pr_err("%s: can't add PIM protocol\n", __func__);
3354 		err = -EAGAIN;
3355 		goto add_proto_fail;
3356 	}
3357 #endif
3358 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
3359 		      ipmr_rtm_getroute, ipmr_rtm_dumproute, 0);
3360 	rtnl_register(RTNL_FAMILY_IPMR, RTM_NEWROUTE,
3361 		      ipmr_rtm_route, NULL, 0);
3362 	rtnl_register(RTNL_FAMILY_IPMR, RTM_DELROUTE,
3363 		      ipmr_rtm_route, NULL, 0);
3364 
3365 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETLINK,
3366 		      NULL, ipmr_rtm_dumplink, 0);
3367 	return 0;
3368 
3369 #ifdef CONFIG_IP_PIMSM_V2
3370 add_proto_fail:
3371 	unregister_netdevice_notifier(&ip_mr_notifier);
3372 #endif
3373 reg_notif_fail:
3374 	unregister_pernet_subsys(&ipmr_net_ops);
3375 reg_pernet_fail:
3376 	kmem_cache_destroy(mrt_cachep);
3377 	return err;
3378 }
3379