xref: /openbmc/linux/net/ipv4/ipmr.c (revision 9b93eb47)
1 /*
2  *	IP multicast routing support for mrouted 3.6/3.8
3  *
4  *		(c) 1995 Alan Cox, <alan@lxorguk.ukuu.org.uk>
5  *	  Linux Consultancy and Custom Driver Development
6  *
7  *	This program is free software; you can redistribute it and/or
8  *	modify it under the terms of the GNU General Public License
9  *	as published by the Free Software Foundation; either version
10  *	2 of the License, or (at your option) any later version.
11  *
12  *	Fixes:
13  *	Michael Chastain	:	Incorrect size of copying.
14  *	Alan Cox		:	Added the cache manager code
15  *	Alan Cox		:	Fixed the clone/copy bug and device race.
16  *	Mike McLagan		:	Routing by source
17  *	Malcolm Beattie		:	Buffer handling fixes.
18  *	Alexey Kuznetsov	:	Double buffer free and other fixes.
19  *	SVR Anand		:	Fixed several multicast bugs and problems.
20  *	Alexey Kuznetsov	:	Status, optimisations and more.
21  *	Brad Parker		:	Better behaviour on mrouted upcall
22  *					overflow.
23  *      Carlos Picoto           :       PIMv1 Support
24  *	Pavlin Ivanov Radoslavov:	PIMv2 Registers must checksum only PIM header
25  *					Relax this requirement to work with older peers.
26  *
27  */
28 
29 #include <linux/uaccess.h>
30 #include <linux/types.h>
31 #include <linux/cache.h>
32 #include <linux/capability.h>
33 #include <linux/errno.h>
34 #include <linux/mm.h>
35 #include <linux/kernel.h>
36 #include <linux/fcntl.h>
37 #include <linux/stat.h>
38 #include <linux/socket.h>
39 #include <linux/in.h>
40 #include <linux/inet.h>
41 #include <linux/netdevice.h>
42 #include <linux/inetdevice.h>
43 #include <linux/igmp.h>
44 #include <linux/proc_fs.h>
45 #include <linux/seq_file.h>
46 #include <linux/mroute.h>
47 #include <linux/init.h>
48 #include <linux/if_ether.h>
49 #include <linux/slab.h>
50 #include <net/net_namespace.h>
51 #include <net/ip.h>
52 #include <net/protocol.h>
53 #include <linux/skbuff.h>
54 #include <net/route.h>
55 #include <net/icmp.h>
56 #include <net/udp.h>
57 #include <net/raw.h>
58 #include <linux/notifier.h>
59 #include <linux/if_arp.h>
60 #include <linux/netfilter_ipv4.h>
61 #include <linux/compat.h>
62 #include <linux/export.h>
63 #include <linux/rhashtable.h>
64 #include <net/ip_tunnels.h>
65 #include <net/checksum.h>
66 #include <net/netlink.h>
67 #include <net/fib_rules.h>
68 #include <linux/netconf.h>
69 #include <net/rtnh.h>
70 
71 #include <linux/nospec.h>
72 
73 struct ipmr_rule {
74 	struct fib_rule		common;
75 };
76 
77 struct ipmr_result {
78 	struct mr_table		*mrt;
79 };
80 
81 /* Big lock, protecting vif table, mrt cache and mroute socket state.
82  * Note that the changes are semaphored via rtnl_lock.
83  */
84 
85 static DEFINE_RWLOCK(mrt_lock);
86 
87 /* Multicast router control variables */
88 
89 /* Special spinlock for queue of unresolved entries */
90 static DEFINE_SPINLOCK(mfc_unres_lock);
91 
92 /* We return to original Alan's scheme. Hash table of resolved
93  * entries is changed only in process context and protected
94  * with weak lock mrt_lock. Queue of unresolved entries is protected
95  * with strong spinlock mfc_unres_lock.
96  *
97  * In this case data path is free of exclusive locks at all.
98  */
99 
100 static struct kmem_cache *mrt_cachep __ro_after_init;
101 
102 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
103 static void ipmr_free_table(struct mr_table *mrt);
104 
105 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
106 			  struct net_device *dev, struct sk_buff *skb,
107 			  struct mfc_cache *cache, int local);
108 static int ipmr_cache_report(struct mr_table *mrt,
109 			     struct sk_buff *pkt, vifi_t vifi, int assert);
110 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
111 				 int cmd);
112 static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
113 static void mroute_clean_tables(struct mr_table *mrt, int flags);
114 static void ipmr_expire_process(struct timer_list *t);
115 
116 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
117 #define ipmr_for_each_table(mrt, net) \
118 	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
119 
120 static struct mr_table *ipmr_mr_table_iter(struct net *net,
121 					   struct mr_table *mrt)
122 {
123 	struct mr_table *ret;
124 
125 	if (!mrt)
126 		ret = list_entry_rcu(net->ipv4.mr_tables.next,
127 				     struct mr_table, list);
128 	else
129 		ret = list_entry_rcu(mrt->list.next,
130 				     struct mr_table, list);
131 
132 	if (&ret->list == &net->ipv4.mr_tables)
133 		return NULL;
134 	return ret;
135 }
136 
137 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
138 {
139 	struct mr_table *mrt;
140 
141 	ipmr_for_each_table(mrt, net) {
142 		if (mrt->id == id)
143 			return mrt;
144 	}
145 	return NULL;
146 }
147 
148 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
149 			   struct mr_table **mrt)
150 {
151 	int err;
152 	struct ipmr_result res;
153 	struct fib_lookup_arg arg = {
154 		.result = &res,
155 		.flags = FIB_LOOKUP_NOREF,
156 	};
157 
158 	/* update flow if oif or iif point to device enslaved to l3mdev */
159 	l3mdev_update_flow(net, flowi4_to_flowi(flp4));
160 
161 	err = fib_rules_lookup(net->ipv4.mr_rules_ops,
162 			       flowi4_to_flowi(flp4), 0, &arg);
163 	if (err < 0)
164 		return err;
165 	*mrt = res.mrt;
166 	return 0;
167 }
168 
169 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
170 			    int flags, struct fib_lookup_arg *arg)
171 {
172 	struct ipmr_result *res = arg->result;
173 	struct mr_table *mrt;
174 
175 	switch (rule->action) {
176 	case FR_ACT_TO_TBL:
177 		break;
178 	case FR_ACT_UNREACHABLE:
179 		return -ENETUNREACH;
180 	case FR_ACT_PROHIBIT:
181 		return -EACCES;
182 	case FR_ACT_BLACKHOLE:
183 	default:
184 		return -EINVAL;
185 	}
186 
187 	arg->table = fib_rule_get_table(rule, arg);
188 
189 	mrt = ipmr_get_table(rule->fr_net, arg->table);
190 	if (!mrt)
191 		return -EAGAIN;
192 	res->mrt = mrt;
193 	return 0;
194 }
195 
196 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
197 {
198 	return 1;
199 }
200 
201 static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
202 	FRA_GENERIC_POLICY,
203 };
204 
205 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
206 			       struct fib_rule_hdr *frh, struct nlattr **tb,
207 			       struct netlink_ext_ack *extack)
208 {
209 	return 0;
210 }
211 
212 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
213 			     struct nlattr **tb)
214 {
215 	return 1;
216 }
217 
218 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
219 			  struct fib_rule_hdr *frh)
220 {
221 	frh->dst_len = 0;
222 	frh->src_len = 0;
223 	frh->tos     = 0;
224 	return 0;
225 }
226 
227 static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
228 	.family		= RTNL_FAMILY_IPMR,
229 	.rule_size	= sizeof(struct ipmr_rule),
230 	.addr_size	= sizeof(u32),
231 	.action		= ipmr_rule_action,
232 	.match		= ipmr_rule_match,
233 	.configure	= ipmr_rule_configure,
234 	.compare	= ipmr_rule_compare,
235 	.fill		= ipmr_rule_fill,
236 	.nlgroup	= RTNLGRP_IPV4_RULE,
237 	.policy		= ipmr_rule_policy,
238 	.owner		= THIS_MODULE,
239 };
240 
241 static int __net_init ipmr_rules_init(struct net *net)
242 {
243 	struct fib_rules_ops *ops;
244 	struct mr_table *mrt;
245 	int err;
246 
247 	ops = fib_rules_register(&ipmr_rules_ops_template, net);
248 	if (IS_ERR(ops))
249 		return PTR_ERR(ops);
250 
251 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
252 
253 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
254 	if (IS_ERR(mrt)) {
255 		err = PTR_ERR(mrt);
256 		goto err1;
257 	}
258 
259 	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
260 	if (err < 0)
261 		goto err2;
262 
263 	net->ipv4.mr_rules_ops = ops;
264 	return 0;
265 
266 err2:
267 	ipmr_free_table(mrt);
268 err1:
269 	fib_rules_unregister(ops);
270 	return err;
271 }
272 
273 static void __net_exit ipmr_rules_exit(struct net *net)
274 {
275 	struct mr_table *mrt, *next;
276 
277 	rtnl_lock();
278 	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
279 		list_del(&mrt->list);
280 		ipmr_free_table(mrt);
281 	}
282 	fib_rules_unregister(net->ipv4.mr_rules_ops);
283 	rtnl_unlock();
284 }
285 
286 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb)
287 {
288 	return fib_rules_dump(net, nb, RTNL_FAMILY_IPMR);
289 }
290 
291 static unsigned int ipmr_rules_seq_read(struct net *net)
292 {
293 	return fib_rules_seq_read(net, RTNL_FAMILY_IPMR);
294 }
295 
296 bool ipmr_rule_default(const struct fib_rule *rule)
297 {
298 	return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
299 }
300 EXPORT_SYMBOL(ipmr_rule_default);
301 #else
302 #define ipmr_for_each_table(mrt, net) \
303 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
304 
305 static struct mr_table *ipmr_mr_table_iter(struct net *net,
306 					   struct mr_table *mrt)
307 {
308 	if (!mrt)
309 		return net->ipv4.mrt;
310 	return NULL;
311 }
312 
313 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
314 {
315 	return net->ipv4.mrt;
316 }
317 
318 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
319 			   struct mr_table **mrt)
320 {
321 	*mrt = net->ipv4.mrt;
322 	return 0;
323 }
324 
325 static int __net_init ipmr_rules_init(struct net *net)
326 {
327 	struct mr_table *mrt;
328 
329 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
330 	if (IS_ERR(mrt))
331 		return PTR_ERR(mrt);
332 	net->ipv4.mrt = mrt;
333 	return 0;
334 }
335 
336 static void __net_exit ipmr_rules_exit(struct net *net)
337 {
338 	rtnl_lock();
339 	ipmr_free_table(net->ipv4.mrt);
340 	net->ipv4.mrt = NULL;
341 	rtnl_unlock();
342 }
343 
344 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb)
345 {
346 	return 0;
347 }
348 
349 static unsigned int ipmr_rules_seq_read(struct net *net)
350 {
351 	return 0;
352 }
353 
354 bool ipmr_rule_default(const struct fib_rule *rule)
355 {
356 	return true;
357 }
358 EXPORT_SYMBOL(ipmr_rule_default);
359 #endif
360 
361 static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
362 				const void *ptr)
363 {
364 	const struct mfc_cache_cmp_arg *cmparg = arg->key;
365 	struct mfc_cache *c = (struct mfc_cache *)ptr;
366 
367 	return cmparg->mfc_mcastgrp != c->mfc_mcastgrp ||
368 	       cmparg->mfc_origin != c->mfc_origin;
369 }
370 
371 static const struct rhashtable_params ipmr_rht_params = {
372 	.head_offset = offsetof(struct mr_mfc, mnode),
373 	.key_offset = offsetof(struct mfc_cache, cmparg),
374 	.key_len = sizeof(struct mfc_cache_cmp_arg),
375 	.nelem_hint = 3,
376 	.obj_cmpfn = ipmr_hash_cmp,
377 	.automatic_shrinking = true,
378 };
379 
380 static void ipmr_new_table_set(struct mr_table *mrt,
381 			       struct net *net)
382 {
383 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
384 	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
385 #endif
386 }
387 
388 static struct mfc_cache_cmp_arg ipmr_mr_table_ops_cmparg_any = {
389 	.mfc_mcastgrp = htonl(INADDR_ANY),
390 	.mfc_origin = htonl(INADDR_ANY),
391 };
392 
393 static struct mr_table_ops ipmr_mr_table_ops = {
394 	.rht_params = &ipmr_rht_params,
395 	.cmparg_any = &ipmr_mr_table_ops_cmparg_any,
396 };
397 
398 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
399 {
400 	struct mr_table *mrt;
401 
402 	/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
403 	if (id != RT_TABLE_DEFAULT && id >= 1000000000)
404 		return ERR_PTR(-EINVAL);
405 
406 	mrt = ipmr_get_table(net, id);
407 	if (mrt)
408 		return mrt;
409 
410 	return mr_table_alloc(net, id, &ipmr_mr_table_ops,
411 			      ipmr_expire_process, ipmr_new_table_set);
412 }
413 
414 static void ipmr_free_table(struct mr_table *mrt)
415 {
416 	del_timer_sync(&mrt->ipmr_expire_timer);
417 	mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC |
418 				 MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC);
419 	rhltable_destroy(&mrt->mfc_hash);
420 	kfree(mrt);
421 }
422 
423 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
424 
425 static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
426 {
427 	struct net *net = dev_net(dev);
428 
429 	dev_close(dev);
430 
431 	dev = __dev_get_by_name(net, "tunl0");
432 	if (dev) {
433 		const struct net_device_ops *ops = dev->netdev_ops;
434 		struct ifreq ifr;
435 		struct ip_tunnel_parm p;
436 
437 		memset(&p, 0, sizeof(p));
438 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
439 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
440 		p.iph.version = 4;
441 		p.iph.ihl = 5;
442 		p.iph.protocol = IPPROTO_IPIP;
443 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
444 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
445 
446 		if (ops->ndo_do_ioctl) {
447 			mm_segment_t oldfs = get_fs();
448 
449 			set_fs(KERNEL_DS);
450 			ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
451 			set_fs(oldfs);
452 		}
453 	}
454 }
455 
456 /* Initialize ipmr pimreg/tunnel in_device */
457 static bool ipmr_init_vif_indev(const struct net_device *dev)
458 {
459 	struct in_device *in_dev;
460 
461 	ASSERT_RTNL();
462 
463 	in_dev = __in_dev_get_rtnl(dev);
464 	if (!in_dev)
465 		return false;
466 	ipv4_devconf_setall(in_dev);
467 	neigh_parms_data_state_setall(in_dev->arp_parms);
468 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
469 
470 	return true;
471 }
472 
473 static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
474 {
475 	struct net_device  *dev;
476 
477 	dev = __dev_get_by_name(net, "tunl0");
478 
479 	if (dev) {
480 		const struct net_device_ops *ops = dev->netdev_ops;
481 		int err;
482 		struct ifreq ifr;
483 		struct ip_tunnel_parm p;
484 
485 		memset(&p, 0, sizeof(p));
486 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
487 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
488 		p.iph.version = 4;
489 		p.iph.ihl = 5;
490 		p.iph.protocol = IPPROTO_IPIP;
491 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
492 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
493 
494 		if (ops->ndo_do_ioctl) {
495 			mm_segment_t oldfs = get_fs();
496 
497 			set_fs(KERNEL_DS);
498 			err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
499 			set_fs(oldfs);
500 		} else {
501 			err = -EOPNOTSUPP;
502 		}
503 		dev = NULL;
504 
505 		if (err == 0 &&
506 		    (dev = __dev_get_by_name(net, p.name)) != NULL) {
507 			dev->flags |= IFF_MULTICAST;
508 			if (!ipmr_init_vif_indev(dev))
509 				goto failure;
510 			if (dev_open(dev, NULL))
511 				goto failure;
512 			dev_hold(dev);
513 		}
514 	}
515 	return dev;
516 
517 failure:
518 	unregister_netdevice(dev);
519 	return NULL;
520 }
521 
522 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
523 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
524 {
525 	struct net *net = dev_net(dev);
526 	struct mr_table *mrt;
527 	struct flowi4 fl4 = {
528 		.flowi4_oif	= dev->ifindex,
529 		.flowi4_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
530 		.flowi4_mark	= skb->mark,
531 	};
532 	int err;
533 
534 	err = ipmr_fib_lookup(net, &fl4, &mrt);
535 	if (err < 0) {
536 		kfree_skb(skb);
537 		return err;
538 	}
539 
540 	read_lock(&mrt_lock);
541 	dev->stats.tx_bytes += skb->len;
542 	dev->stats.tx_packets++;
543 	ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
544 	read_unlock(&mrt_lock);
545 	kfree_skb(skb);
546 	return NETDEV_TX_OK;
547 }
548 
549 static int reg_vif_get_iflink(const struct net_device *dev)
550 {
551 	return 0;
552 }
553 
554 static const struct net_device_ops reg_vif_netdev_ops = {
555 	.ndo_start_xmit	= reg_vif_xmit,
556 	.ndo_get_iflink = reg_vif_get_iflink,
557 };
558 
559 static void reg_vif_setup(struct net_device *dev)
560 {
561 	dev->type		= ARPHRD_PIMREG;
562 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
563 	dev->flags		= IFF_NOARP;
564 	dev->netdev_ops		= &reg_vif_netdev_ops;
565 	dev->needs_free_netdev	= true;
566 	dev->features		|= NETIF_F_NETNS_LOCAL;
567 }
568 
569 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
570 {
571 	struct net_device *dev;
572 	char name[IFNAMSIZ];
573 
574 	if (mrt->id == RT_TABLE_DEFAULT)
575 		sprintf(name, "pimreg");
576 	else
577 		sprintf(name, "pimreg%u", mrt->id);
578 
579 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
580 
581 	if (!dev)
582 		return NULL;
583 
584 	dev_net_set(dev, net);
585 
586 	if (register_netdevice(dev)) {
587 		free_netdev(dev);
588 		return NULL;
589 	}
590 
591 	if (!ipmr_init_vif_indev(dev))
592 		goto failure;
593 	if (dev_open(dev, NULL))
594 		goto failure;
595 
596 	dev_hold(dev);
597 
598 	return dev;
599 
600 failure:
601 	unregister_netdevice(dev);
602 	return NULL;
603 }
604 
605 /* called with rcu_read_lock() */
606 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
607 		     unsigned int pimlen)
608 {
609 	struct net_device *reg_dev = NULL;
610 	struct iphdr *encap;
611 
612 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
613 	/* Check that:
614 	 * a. packet is really sent to a multicast group
615 	 * b. packet is not a NULL-REGISTER
616 	 * c. packet is not truncated
617 	 */
618 	if (!ipv4_is_multicast(encap->daddr) ||
619 	    encap->tot_len == 0 ||
620 	    ntohs(encap->tot_len) + pimlen > skb->len)
621 		return 1;
622 
623 	read_lock(&mrt_lock);
624 	if (mrt->mroute_reg_vif_num >= 0)
625 		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
626 	read_unlock(&mrt_lock);
627 
628 	if (!reg_dev)
629 		return 1;
630 
631 	skb->mac_header = skb->network_header;
632 	skb_pull(skb, (u8 *)encap - skb->data);
633 	skb_reset_network_header(skb);
634 	skb->protocol = htons(ETH_P_IP);
635 	skb->ip_summed = CHECKSUM_NONE;
636 
637 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
638 
639 	netif_rx(skb);
640 
641 	return NET_RX_SUCCESS;
642 }
643 #else
644 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
645 {
646 	return NULL;
647 }
648 #endif
649 
650 static int call_ipmr_vif_entry_notifiers(struct net *net,
651 					 enum fib_event_type event_type,
652 					 struct vif_device *vif,
653 					 vifi_t vif_index, u32 tb_id)
654 {
655 	return mr_call_vif_notifiers(net, RTNL_FAMILY_IPMR, event_type,
656 				     vif, vif_index, tb_id,
657 				     &net->ipv4.ipmr_seq);
658 }
659 
660 static int call_ipmr_mfc_entry_notifiers(struct net *net,
661 					 enum fib_event_type event_type,
662 					 struct mfc_cache *mfc, u32 tb_id)
663 {
664 	return mr_call_mfc_notifiers(net, RTNL_FAMILY_IPMR, event_type,
665 				     &mfc->_c, tb_id, &net->ipv4.ipmr_seq);
666 }
667 
668 /**
669  *	vif_delete - Delete a VIF entry
670  *	@notify: Set to 1, if the caller is a notifier_call
671  */
672 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
673 		      struct list_head *head)
674 {
675 	struct net *net = read_pnet(&mrt->net);
676 	struct vif_device *v;
677 	struct net_device *dev;
678 	struct in_device *in_dev;
679 
680 	if (vifi < 0 || vifi >= mrt->maxvif)
681 		return -EADDRNOTAVAIL;
682 
683 	v = &mrt->vif_table[vifi];
684 
685 	if (VIF_EXISTS(mrt, vifi))
686 		call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_DEL, v, vifi,
687 					      mrt->id);
688 
689 	write_lock_bh(&mrt_lock);
690 	dev = v->dev;
691 	v->dev = NULL;
692 
693 	if (!dev) {
694 		write_unlock_bh(&mrt_lock);
695 		return -EADDRNOTAVAIL;
696 	}
697 
698 	if (vifi == mrt->mroute_reg_vif_num)
699 		mrt->mroute_reg_vif_num = -1;
700 
701 	if (vifi + 1 == mrt->maxvif) {
702 		int tmp;
703 
704 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
705 			if (VIF_EXISTS(mrt, tmp))
706 				break;
707 		}
708 		mrt->maxvif = tmp+1;
709 	}
710 
711 	write_unlock_bh(&mrt_lock);
712 
713 	dev_set_allmulti(dev, -1);
714 
715 	in_dev = __in_dev_get_rtnl(dev);
716 	if (in_dev) {
717 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
718 		inet_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
719 					    NETCONFA_MC_FORWARDING,
720 					    dev->ifindex, &in_dev->cnf);
721 		ip_rt_multicast_event(in_dev);
722 	}
723 
724 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
725 		unregister_netdevice_queue(dev, head);
726 
727 	dev_put(dev);
728 	return 0;
729 }
730 
731 static void ipmr_cache_free_rcu(struct rcu_head *head)
732 {
733 	struct mr_mfc *c = container_of(head, struct mr_mfc, rcu);
734 
735 	kmem_cache_free(mrt_cachep, (struct mfc_cache *)c);
736 }
737 
738 static void ipmr_cache_free(struct mfc_cache *c)
739 {
740 	call_rcu(&c->_c.rcu, ipmr_cache_free_rcu);
741 }
742 
743 /* Destroy an unresolved cache entry, killing queued skbs
744  * and reporting error to netlink readers.
745  */
746 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
747 {
748 	struct net *net = read_pnet(&mrt->net);
749 	struct sk_buff *skb;
750 	struct nlmsgerr *e;
751 
752 	atomic_dec(&mrt->cache_resolve_queue_len);
753 
754 	while ((skb = skb_dequeue(&c->_c.mfc_un.unres.unresolved))) {
755 		if (ip_hdr(skb)->version == 0) {
756 			struct nlmsghdr *nlh = skb_pull(skb,
757 							sizeof(struct iphdr));
758 			nlh->nlmsg_type = NLMSG_ERROR;
759 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
760 			skb_trim(skb, nlh->nlmsg_len);
761 			e = nlmsg_data(nlh);
762 			e->error = -ETIMEDOUT;
763 			memset(&e->msg, 0, sizeof(e->msg));
764 
765 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
766 		} else {
767 			kfree_skb(skb);
768 		}
769 	}
770 
771 	ipmr_cache_free(c);
772 }
773 
774 /* Timer process for the unresolved queue. */
775 static void ipmr_expire_process(struct timer_list *t)
776 {
777 	struct mr_table *mrt = from_timer(mrt, t, ipmr_expire_timer);
778 	struct mr_mfc *c, *next;
779 	unsigned long expires;
780 	unsigned long now;
781 
782 	if (!spin_trylock(&mfc_unres_lock)) {
783 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
784 		return;
785 	}
786 
787 	if (list_empty(&mrt->mfc_unres_queue))
788 		goto out;
789 
790 	now = jiffies;
791 	expires = 10*HZ;
792 
793 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
794 		if (time_after(c->mfc_un.unres.expires, now)) {
795 			unsigned long interval = c->mfc_un.unres.expires - now;
796 			if (interval < expires)
797 				expires = interval;
798 			continue;
799 		}
800 
801 		list_del(&c->list);
802 		mroute_netlink_event(mrt, (struct mfc_cache *)c, RTM_DELROUTE);
803 		ipmr_destroy_unres(mrt, (struct mfc_cache *)c);
804 	}
805 
806 	if (!list_empty(&mrt->mfc_unres_queue))
807 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
808 
809 out:
810 	spin_unlock(&mfc_unres_lock);
811 }
812 
813 /* Fill oifs list. It is called under write locked mrt_lock. */
814 static void ipmr_update_thresholds(struct mr_table *mrt, struct mr_mfc *cache,
815 				   unsigned char *ttls)
816 {
817 	int vifi;
818 
819 	cache->mfc_un.res.minvif = MAXVIFS;
820 	cache->mfc_un.res.maxvif = 0;
821 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
822 
823 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
824 		if (VIF_EXISTS(mrt, vifi) &&
825 		    ttls[vifi] && ttls[vifi] < 255) {
826 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
827 			if (cache->mfc_un.res.minvif > vifi)
828 				cache->mfc_un.res.minvif = vifi;
829 			if (cache->mfc_un.res.maxvif <= vifi)
830 				cache->mfc_un.res.maxvif = vifi + 1;
831 		}
832 	}
833 	cache->mfc_un.res.lastuse = jiffies;
834 }
835 
836 static int vif_add(struct net *net, struct mr_table *mrt,
837 		   struct vifctl *vifc, int mrtsock)
838 {
839 	struct netdev_phys_item_id ppid = { };
840 	int vifi = vifc->vifc_vifi;
841 	struct vif_device *v = &mrt->vif_table[vifi];
842 	struct net_device *dev;
843 	struct in_device *in_dev;
844 	int err;
845 
846 	/* Is vif busy ? */
847 	if (VIF_EXISTS(mrt, vifi))
848 		return -EADDRINUSE;
849 
850 	switch (vifc->vifc_flags) {
851 	case VIFF_REGISTER:
852 		if (!ipmr_pimsm_enabled())
853 			return -EINVAL;
854 		/* Special Purpose VIF in PIM
855 		 * All the packets will be sent to the daemon
856 		 */
857 		if (mrt->mroute_reg_vif_num >= 0)
858 			return -EADDRINUSE;
859 		dev = ipmr_reg_vif(net, mrt);
860 		if (!dev)
861 			return -ENOBUFS;
862 		err = dev_set_allmulti(dev, 1);
863 		if (err) {
864 			unregister_netdevice(dev);
865 			dev_put(dev);
866 			return err;
867 		}
868 		break;
869 	case VIFF_TUNNEL:
870 		dev = ipmr_new_tunnel(net, vifc);
871 		if (!dev)
872 			return -ENOBUFS;
873 		err = dev_set_allmulti(dev, 1);
874 		if (err) {
875 			ipmr_del_tunnel(dev, vifc);
876 			dev_put(dev);
877 			return err;
878 		}
879 		break;
880 	case VIFF_USE_IFINDEX:
881 	case 0:
882 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
883 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
884 			if (dev && !__in_dev_get_rtnl(dev)) {
885 				dev_put(dev);
886 				return -EADDRNOTAVAIL;
887 			}
888 		} else {
889 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
890 		}
891 		if (!dev)
892 			return -EADDRNOTAVAIL;
893 		err = dev_set_allmulti(dev, 1);
894 		if (err) {
895 			dev_put(dev);
896 			return err;
897 		}
898 		break;
899 	default:
900 		return -EINVAL;
901 	}
902 
903 	in_dev = __in_dev_get_rtnl(dev);
904 	if (!in_dev) {
905 		dev_put(dev);
906 		return -EADDRNOTAVAIL;
907 	}
908 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
909 	inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING,
910 				    dev->ifindex, &in_dev->cnf);
911 	ip_rt_multicast_event(in_dev);
912 
913 	/* Fill in the VIF structures */
914 	vif_device_init(v, dev, vifc->vifc_rate_limit,
915 			vifc->vifc_threshold,
916 			vifc->vifc_flags | (!mrtsock ? VIFF_STATIC : 0),
917 			(VIFF_TUNNEL | VIFF_REGISTER));
918 
919 	err = dev_get_port_parent_id(dev, &ppid, true);
920 	if (err == 0) {
921 		memcpy(v->dev_parent_id.id, ppid.id, ppid.id_len);
922 		v->dev_parent_id.id_len = ppid.id_len;
923 	} else {
924 		v->dev_parent_id.id_len = 0;
925 	}
926 
927 	v->local = vifc->vifc_lcl_addr.s_addr;
928 	v->remote = vifc->vifc_rmt_addr.s_addr;
929 
930 	/* And finish update writing critical data */
931 	write_lock_bh(&mrt_lock);
932 	v->dev = dev;
933 	if (v->flags & VIFF_REGISTER)
934 		mrt->mroute_reg_vif_num = vifi;
935 	if (vifi+1 > mrt->maxvif)
936 		mrt->maxvif = vifi+1;
937 	write_unlock_bh(&mrt_lock);
938 	call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD, v, vifi, mrt->id);
939 	return 0;
940 }
941 
942 /* called with rcu_read_lock() */
943 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
944 					 __be32 origin,
945 					 __be32 mcastgrp)
946 {
947 	struct mfc_cache_cmp_arg arg = {
948 			.mfc_mcastgrp = mcastgrp,
949 			.mfc_origin = origin
950 	};
951 
952 	return mr_mfc_find(mrt, &arg);
953 }
954 
955 /* Look for a (*,G) entry */
956 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
957 					     __be32 mcastgrp, int vifi)
958 {
959 	struct mfc_cache_cmp_arg arg = {
960 			.mfc_mcastgrp = mcastgrp,
961 			.mfc_origin = htonl(INADDR_ANY)
962 	};
963 
964 	if (mcastgrp == htonl(INADDR_ANY))
965 		return mr_mfc_find_any_parent(mrt, vifi);
966 	return mr_mfc_find_any(mrt, vifi, &arg);
967 }
968 
969 /* Look for a (S,G,iif) entry if parent != -1 */
970 static struct mfc_cache *ipmr_cache_find_parent(struct mr_table *mrt,
971 						__be32 origin, __be32 mcastgrp,
972 						int parent)
973 {
974 	struct mfc_cache_cmp_arg arg = {
975 			.mfc_mcastgrp = mcastgrp,
976 			.mfc_origin = origin,
977 	};
978 
979 	return mr_mfc_find_parent(mrt, &arg, parent);
980 }
981 
982 /* Allocate a multicast cache entry */
983 static struct mfc_cache *ipmr_cache_alloc(void)
984 {
985 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
986 
987 	if (c) {
988 		c->_c.mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
989 		c->_c.mfc_un.res.minvif = MAXVIFS;
990 		c->_c.free = ipmr_cache_free_rcu;
991 		refcount_set(&c->_c.mfc_un.res.refcount, 1);
992 	}
993 	return c;
994 }
995 
996 static struct mfc_cache *ipmr_cache_alloc_unres(void)
997 {
998 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
999 
1000 	if (c) {
1001 		skb_queue_head_init(&c->_c.mfc_un.unres.unresolved);
1002 		c->_c.mfc_un.unres.expires = jiffies + 10 * HZ;
1003 	}
1004 	return c;
1005 }
1006 
1007 /* A cache entry has gone into a resolved state from queued */
1008 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
1009 			       struct mfc_cache *uc, struct mfc_cache *c)
1010 {
1011 	struct sk_buff *skb;
1012 	struct nlmsgerr *e;
1013 
1014 	/* Play the pending entries through our router */
1015 	while ((skb = __skb_dequeue(&uc->_c.mfc_un.unres.unresolved))) {
1016 		if (ip_hdr(skb)->version == 0) {
1017 			struct nlmsghdr *nlh = skb_pull(skb,
1018 							sizeof(struct iphdr));
1019 
1020 			if (mr_fill_mroute(mrt, skb, &c->_c,
1021 					   nlmsg_data(nlh)) > 0) {
1022 				nlh->nlmsg_len = skb_tail_pointer(skb) -
1023 						 (u8 *)nlh;
1024 			} else {
1025 				nlh->nlmsg_type = NLMSG_ERROR;
1026 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
1027 				skb_trim(skb, nlh->nlmsg_len);
1028 				e = nlmsg_data(nlh);
1029 				e->error = -EMSGSIZE;
1030 				memset(&e->msg, 0, sizeof(e->msg));
1031 			}
1032 
1033 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
1034 		} else {
1035 			ip_mr_forward(net, mrt, skb->dev, skb, c, 0);
1036 		}
1037 	}
1038 }
1039 
1040 /* Bounce a cache query up to mrouted and netlink.
1041  *
1042  * Called under mrt_lock.
1043  */
1044 static int ipmr_cache_report(struct mr_table *mrt,
1045 			     struct sk_buff *pkt, vifi_t vifi, int assert)
1046 {
1047 	const int ihl = ip_hdrlen(pkt);
1048 	struct sock *mroute_sk;
1049 	struct igmphdr *igmp;
1050 	struct igmpmsg *msg;
1051 	struct sk_buff *skb;
1052 	int ret;
1053 
1054 	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE)
1055 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
1056 	else
1057 		skb = alloc_skb(128, GFP_ATOMIC);
1058 
1059 	if (!skb)
1060 		return -ENOBUFS;
1061 
1062 	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE) {
1063 		/* Ugly, but we have no choice with this interface.
1064 		 * Duplicate old header, fix ihl, length etc.
1065 		 * And all this only to mangle msg->im_msgtype and
1066 		 * to set msg->im_mbz to "mbz" :-)
1067 		 */
1068 		skb_push(skb, sizeof(struct iphdr));
1069 		skb_reset_network_header(skb);
1070 		skb_reset_transport_header(skb);
1071 		msg = (struct igmpmsg *)skb_network_header(skb);
1072 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
1073 		msg->im_msgtype = assert;
1074 		msg->im_mbz = 0;
1075 		if (assert == IGMPMSG_WRVIFWHOLE)
1076 			msg->im_vif = vifi;
1077 		else
1078 			msg->im_vif = mrt->mroute_reg_vif_num;
1079 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
1080 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
1081 					     sizeof(struct iphdr));
1082 	} else {
1083 		/* Copy the IP header */
1084 		skb_set_network_header(skb, skb->len);
1085 		skb_put(skb, ihl);
1086 		skb_copy_to_linear_data(skb, pkt->data, ihl);
1087 		/* Flag to the kernel this is a route add */
1088 		ip_hdr(skb)->protocol = 0;
1089 		msg = (struct igmpmsg *)skb_network_header(skb);
1090 		msg->im_vif = vifi;
1091 		skb_dst_set(skb, dst_clone(skb_dst(pkt)));
1092 		/* Add our header */
1093 		igmp = skb_put(skb, sizeof(struct igmphdr));
1094 		igmp->type = assert;
1095 		msg->im_msgtype = assert;
1096 		igmp->code = 0;
1097 		ip_hdr(skb)->tot_len = htons(skb->len);	/* Fix the length */
1098 		skb->transport_header = skb->network_header;
1099 	}
1100 
1101 	rcu_read_lock();
1102 	mroute_sk = rcu_dereference(mrt->mroute_sk);
1103 	if (!mroute_sk) {
1104 		rcu_read_unlock();
1105 		kfree_skb(skb);
1106 		return -EINVAL;
1107 	}
1108 
1109 	igmpmsg_netlink_event(mrt, skb);
1110 
1111 	/* Deliver to mrouted */
1112 	ret = sock_queue_rcv_skb(mroute_sk, skb);
1113 	rcu_read_unlock();
1114 	if (ret < 0) {
1115 		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1116 		kfree_skb(skb);
1117 	}
1118 
1119 	return ret;
1120 }
1121 
1122 /* Queue a packet for resolution. It gets locked cache entry! */
1123 static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
1124 				 struct sk_buff *skb, struct net_device *dev)
1125 {
1126 	const struct iphdr *iph = ip_hdr(skb);
1127 	struct mfc_cache *c;
1128 	bool found = false;
1129 	int err;
1130 
1131 	spin_lock_bh(&mfc_unres_lock);
1132 	list_for_each_entry(c, &mrt->mfc_unres_queue, _c.list) {
1133 		if (c->mfc_mcastgrp == iph->daddr &&
1134 		    c->mfc_origin == iph->saddr) {
1135 			found = true;
1136 			break;
1137 		}
1138 	}
1139 
1140 	if (!found) {
1141 		/* Create a new entry if allowable */
1142 		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
1143 		    (c = ipmr_cache_alloc_unres()) == NULL) {
1144 			spin_unlock_bh(&mfc_unres_lock);
1145 
1146 			kfree_skb(skb);
1147 			return -ENOBUFS;
1148 		}
1149 
1150 		/* Fill in the new cache entry */
1151 		c->_c.mfc_parent = -1;
1152 		c->mfc_origin	= iph->saddr;
1153 		c->mfc_mcastgrp	= iph->daddr;
1154 
1155 		/* Reflect first query at mrouted. */
1156 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1157 
1158 		if (err < 0) {
1159 			/* If the report failed throw the cache entry
1160 			   out - Brad Parker
1161 			 */
1162 			spin_unlock_bh(&mfc_unres_lock);
1163 
1164 			ipmr_cache_free(c);
1165 			kfree_skb(skb);
1166 			return err;
1167 		}
1168 
1169 		atomic_inc(&mrt->cache_resolve_queue_len);
1170 		list_add(&c->_c.list, &mrt->mfc_unres_queue);
1171 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1172 
1173 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1174 			mod_timer(&mrt->ipmr_expire_timer,
1175 				  c->_c.mfc_un.unres.expires);
1176 	}
1177 
1178 	/* See if we can append the packet */
1179 	if (c->_c.mfc_un.unres.unresolved.qlen > 3) {
1180 		kfree_skb(skb);
1181 		err = -ENOBUFS;
1182 	} else {
1183 		if (dev) {
1184 			skb->dev = dev;
1185 			skb->skb_iif = dev->ifindex;
1186 		}
1187 		skb_queue_tail(&c->_c.mfc_un.unres.unresolved, skb);
1188 		err = 0;
1189 	}
1190 
1191 	spin_unlock_bh(&mfc_unres_lock);
1192 	return err;
1193 }
1194 
1195 /* MFC cache manipulation by user space mroute daemon */
1196 
1197 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1198 {
1199 	struct net *net = read_pnet(&mrt->net);
1200 	struct mfc_cache *c;
1201 
1202 	/* The entries are added/deleted only under RTNL */
1203 	rcu_read_lock();
1204 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1205 				   mfc->mfcc_mcastgrp.s_addr, parent);
1206 	rcu_read_unlock();
1207 	if (!c)
1208 		return -ENOENT;
1209 	rhltable_remove(&mrt->mfc_hash, &c->_c.mnode, ipmr_rht_params);
1210 	list_del_rcu(&c->_c.list);
1211 	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, c, mrt->id);
1212 	mroute_netlink_event(mrt, c, RTM_DELROUTE);
1213 	mr_cache_put(&c->_c);
1214 
1215 	return 0;
1216 }
1217 
1218 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1219 			struct mfcctl *mfc, int mrtsock, int parent)
1220 {
1221 	struct mfc_cache *uc, *c;
1222 	struct mr_mfc *_uc;
1223 	bool found;
1224 	int ret;
1225 
1226 	if (mfc->mfcc_parent >= MAXVIFS)
1227 		return -ENFILE;
1228 
1229 	/* The entries are added/deleted only under RTNL */
1230 	rcu_read_lock();
1231 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1232 				   mfc->mfcc_mcastgrp.s_addr, parent);
1233 	rcu_read_unlock();
1234 	if (c) {
1235 		write_lock_bh(&mrt_lock);
1236 		c->_c.mfc_parent = mfc->mfcc_parent;
1237 		ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
1238 		if (!mrtsock)
1239 			c->_c.mfc_flags |= MFC_STATIC;
1240 		write_unlock_bh(&mrt_lock);
1241 		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, c,
1242 					      mrt->id);
1243 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1244 		return 0;
1245 	}
1246 
1247 	if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1248 	    !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1249 		return -EINVAL;
1250 
1251 	c = ipmr_cache_alloc();
1252 	if (!c)
1253 		return -ENOMEM;
1254 
1255 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1256 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1257 	c->_c.mfc_parent = mfc->mfcc_parent;
1258 	ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
1259 	if (!mrtsock)
1260 		c->_c.mfc_flags |= MFC_STATIC;
1261 
1262 	ret = rhltable_insert_key(&mrt->mfc_hash, &c->cmparg, &c->_c.mnode,
1263 				  ipmr_rht_params);
1264 	if (ret) {
1265 		pr_err("ipmr: rhtable insert error %d\n", ret);
1266 		ipmr_cache_free(c);
1267 		return ret;
1268 	}
1269 	list_add_tail_rcu(&c->_c.list, &mrt->mfc_cache_list);
1270 	/* Check to see if we resolved a queued list. If so we
1271 	 * need to send on the frames and tidy up.
1272 	 */
1273 	found = false;
1274 	spin_lock_bh(&mfc_unres_lock);
1275 	list_for_each_entry(_uc, &mrt->mfc_unres_queue, list) {
1276 		uc = (struct mfc_cache *)_uc;
1277 		if (uc->mfc_origin == c->mfc_origin &&
1278 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1279 			list_del(&_uc->list);
1280 			atomic_dec(&mrt->cache_resolve_queue_len);
1281 			found = true;
1282 			break;
1283 		}
1284 	}
1285 	if (list_empty(&mrt->mfc_unres_queue))
1286 		del_timer(&mrt->ipmr_expire_timer);
1287 	spin_unlock_bh(&mfc_unres_lock);
1288 
1289 	if (found) {
1290 		ipmr_cache_resolve(net, mrt, uc, c);
1291 		ipmr_cache_free(uc);
1292 	}
1293 	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, c, mrt->id);
1294 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1295 	return 0;
1296 }
1297 
1298 /* Close the multicast socket, and clear the vif tables etc */
1299 static void mroute_clean_tables(struct mr_table *mrt, int flags)
1300 {
1301 	struct net *net = read_pnet(&mrt->net);
1302 	struct mr_mfc *c, *tmp;
1303 	struct mfc_cache *cache;
1304 	LIST_HEAD(list);
1305 	int i;
1306 
1307 	/* Shut down all active vif entries */
1308 	if (flags & (MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC)) {
1309 		for (i = 0; i < mrt->maxvif; i++) {
1310 			if (((mrt->vif_table[i].flags & VIFF_STATIC) &&
1311 			     !(flags & MRT_FLUSH_VIFS_STATIC)) ||
1312 			    (!(mrt->vif_table[i].flags & VIFF_STATIC) && !(flags & MRT_FLUSH_VIFS)))
1313 				continue;
1314 			vif_delete(mrt, i, 0, &list);
1315 		}
1316 		unregister_netdevice_many(&list);
1317 	}
1318 
1319 	/* Wipe the cache */
1320 	if (flags & (MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC)) {
1321 		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
1322 			if (((c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC_STATIC)) ||
1323 			    (!(c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC)))
1324 				continue;
1325 			rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
1326 			list_del_rcu(&c->list);
1327 			cache = (struct mfc_cache *)c;
1328 			call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
1329 						      mrt->id);
1330 			mroute_netlink_event(mrt, cache, RTM_DELROUTE);
1331 			mr_cache_put(c);
1332 		}
1333 	}
1334 
1335 	if (flags & MRT_FLUSH_MFC) {
1336 		if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1337 			spin_lock_bh(&mfc_unres_lock);
1338 			list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
1339 				list_del(&c->list);
1340 				cache = (struct mfc_cache *)c;
1341 				mroute_netlink_event(mrt, cache, RTM_DELROUTE);
1342 				ipmr_destroy_unres(mrt, cache);
1343 			}
1344 			spin_unlock_bh(&mfc_unres_lock);
1345 		}
1346 	}
1347 }
1348 
1349 /* called from ip_ra_control(), before an RCU grace period,
1350  * we dont need to call synchronize_rcu() here
1351  */
1352 static void mrtsock_destruct(struct sock *sk)
1353 {
1354 	struct net *net = sock_net(sk);
1355 	struct mr_table *mrt;
1356 
1357 	rtnl_lock();
1358 	ipmr_for_each_table(mrt, net) {
1359 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1360 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1361 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1362 						    NETCONFA_MC_FORWARDING,
1363 						    NETCONFA_IFINDEX_ALL,
1364 						    net->ipv4.devconf_all);
1365 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1366 			mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_MFC);
1367 		}
1368 	}
1369 	rtnl_unlock();
1370 }
1371 
1372 /* Socket options and virtual interface manipulation. The whole
1373  * virtual interface system is a complete heap, but unfortunately
1374  * that's how BSD mrouted happens to think. Maybe one day with a proper
1375  * MOSPF/PIM router set up we can clean this up.
1376  */
1377 
1378 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
1379 			 unsigned int optlen)
1380 {
1381 	struct net *net = sock_net(sk);
1382 	int val, ret = 0, parent = 0;
1383 	struct mr_table *mrt;
1384 	struct vifctl vif;
1385 	struct mfcctl mfc;
1386 	bool do_wrvifwhole;
1387 	u32 uval;
1388 
1389 	/* There's one exception to the lock - MRT_DONE which needs to unlock */
1390 	rtnl_lock();
1391 	if (sk->sk_type != SOCK_RAW ||
1392 	    inet_sk(sk)->inet_num != IPPROTO_IGMP) {
1393 		ret = -EOPNOTSUPP;
1394 		goto out_unlock;
1395 	}
1396 
1397 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1398 	if (!mrt) {
1399 		ret = -ENOENT;
1400 		goto out_unlock;
1401 	}
1402 	if (optname != MRT_INIT) {
1403 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1404 		    !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
1405 			ret = -EACCES;
1406 			goto out_unlock;
1407 		}
1408 	}
1409 
1410 	switch (optname) {
1411 	case MRT_INIT:
1412 		if (optlen != sizeof(int)) {
1413 			ret = -EINVAL;
1414 			break;
1415 		}
1416 		if (rtnl_dereference(mrt->mroute_sk)) {
1417 			ret = -EADDRINUSE;
1418 			break;
1419 		}
1420 
1421 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1422 		if (ret == 0) {
1423 			rcu_assign_pointer(mrt->mroute_sk, sk);
1424 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1425 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1426 						    NETCONFA_MC_FORWARDING,
1427 						    NETCONFA_IFINDEX_ALL,
1428 						    net->ipv4.devconf_all);
1429 		}
1430 		break;
1431 	case MRT_DONE:
1432 		if (sk != rcu_access_pointer(mrt->mroute_sk)) {
1433 			ret = -EACCES;
1434 		} else {
1435 			/* We need to unlock here because mrtsock_destruct takes
1436 			 * care of rtnl itself and we can't change that due to
1437 			 * the IP_ROUTER_ALERT setsockopt which runs without it.
1438 			 */
1439 			rtnl_unlock();
1440 			ret = ip_ra_control(sk, 0, NULL);
1441 			goto out;
1442 		}
1443 		break;
1444 	case MRT_ADD_VIF:
1445 	case MRT_DEL_VIF:
1446 		if (optlen != sizeof(vif)) {
1447 			ret = -EINVAL;
1448 			break;
1449 		}
1450 		if (copy_from_user(&vif, optval, sizeof(vif))) {
1451 			ret = -EFAULT;
1452 			break;
1453 		}
1454 		if (vif.vifc_vifi >= MAXVIFS) {
1455 			ret = -ENFILE;
1456 			break;
1457 		}
1458 		if (optname == MRT_ADD_VIF) {
1459 			ret = vif_add(net, mrt, &vif,
1460 				      sk == rtnl_dereference(mrt->mroute_sk));
1461 		} else {
1462 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1463 		}
1464 		break;
1465 	/* Manipulate the forwarding caches. These live
1466 	 * in a sort of kernel/user symbiosis.
1467 	 */
1468 	case MRT_ADD_MFC:
1469 	case MRT_DEL_MFC:
1470 		parent = -1;
1471 		/* fall through */
1472 	case MRT_ADD_MFC_PROXY:
1473 	case MRT_DEL_MFC_PROXY:
1474 		if (optlen != sizeof(mfc)) {
1475 			ret = -EINVAL;
1476 			break;
1477 		}
1478 		if (copy_from_user(&mfc, optval, sizeof(mfc))) {
1479 			ret = -EFAULT;
1480 			break;
1481 		}
1482 		if (parent == 0)
1483 			parent = mfc.mfcc_parent;
1484 		if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1485 			ret = ipmr_mfc_delete(mrt, &mfc, parent);
1486 		else
1487 			ret = ipmr_mfc_add(net, mrt, &mfc,
1488 					   sk == rtnl_dereference(mrt->mroute_sk),
1489 					   parent);
1490 		break;
1491 	case MRT_FLUSH:
1492 		if (optlen != sizeof(val)) {
1493 			ret = -EINVAL;
1494 			break;
1495 		}
1496 		if (get_user(val, (int __user *)optval)) {
1497 			ret = -EFAULT;
1498 			break;
1499 		}
1500 		mroute_clean_tables(mrt, val);
1501 		break;
1502 	/* Control PIM assert. */
1503 	case MRT_ASSERT:
1504 		if (optlen != sizeof(val)) {
1505 			ret = -EINVAL;
1506 			break;
1507 		}
1508 		if (get_user(val, (int __user *)optval)) {
1509 			ret = -EFAULT;
1510 			break;
1511 		}
1512 		mrt->mroute_do_assert = val;
1513 		break;
1514 	case MRT_PIM:
1515 		if (!ipmr_pimsm_enabled()) {
1516 			ret = -ENOPROTOOPT;
1517 			break;
1518 		}
1519 		if (optlen != sizeof(val)) {
1520 			ret = -EINVAL;
1521 			break;
1522 		}
1523 		if (get_user(val, (int __user *)optval)) {
1524 			ret = -EFAULT;
1525 			break;
1526 		}
1527 
1528 		do_wrvifwhole = (val == IGMPMSG_WRVIFWHOLE);
1529 		val = !!val;
1530 		if (val != mrt->mroute_do_pim) {
1531 			mrt->mroute_do_pim = val;
1532 			mrt->mroute_do_assert = val;
1533 			mrt->mroute_do_wrvifwhole = do_wrvifwhole;
1534 		}
1535 		break;
1536 	case MRT_TABLE:
1537 		if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) {
1538 			ret = -ENOPROTOOPT;
1539 			break;
1540 		}
1541 		if (optlen != sizeof(uval)) {
1542 			ret = -EINVAL;
1543 			break;
1544 		}
1545 		if (get_user(uval, (u32 __user *)optval)) {
1546 			ret = -EFAULT;
1547 			break;
1548 		}
1549 
1550 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1551 			ret = -EBUSY;
1552 		} else {
1553 			mrt = ipmr_new_table(net, uval);
1554 			if (IS_ERR(mrt))
1555 				ret = PTR_ERR(mrt);
1556 			else
1557 				raw_sk(sk)->ipmr_table = uval;
1558 		}
1559 		break;
1560 	/* Spurious command, or MRT_VERSION which you cannot set. */
1561 	default:
1562 		ret = -ENOPROTOOPT;
1563 	}
1564 out_unlock:
1565 	rtnl_unlock();
1566 out:
1567 	return ret;
1568 }
1569 
1570 /* Getsock opt support for the multicast routing system. */
1571 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1572 {
1573 	int olr;
1574 	int val;
1575 	struct net *net = sock_net(sk);
1576 	struct mr_table *mrt;
1577 
1578 	if (sk->sk_type != SOCK_RAW ||
1579 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1580 		return -EOPNOTSUPP;
1581 
1582 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1583 	if (!mrt)
1584 		return -ENOENT;
1585 
1586 	switch (optname) {
1587 	case MRT_VERSION:
1588 		val = 0x0305;
1589 		break;
1590 	case MRT_PIM:
1591 		if (!ipmr_pimsm_enabled())
1592 			return -ENOPROTOOPT;
1593 		val = mrt->mroute_do_pim;
1594 		break;
1595 	case MRT_ASSERT:
1596 		val = mrt->mroute_do_assert;
1597 		break;
1598 	default:
1599 		return -ENOPROTOOPT;
1600 	}
1601 
1602 	if (get_user(olr, optlen))
1603 		return -EFAULT;
1604 	olr = min_t(unsigned int, olr, sizeof(int));
1605 	if (olr < 0)
1606 		return -EINVAL;
1607 	if (put_user(olr, optlen))
1608 		return -EFAULT;
1609 	if (copy_to_user(optval, &val, olr))
1610 		return -EFAULT;
1611 	return 0;
1612 }
1613 
1614 /* The IP multicast ioctl support routines. */
1615 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1616 {
1617 	struct sioc_sg_req sr;
1618 	struct sioc_vif_req vr;
1619 	struct vif_device *vif;
1620 	struct mfc_cache *c;
1621 	struct net *net = sock_net(sk);
1622 	struct mr_table *mrt;
1623 
1624 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1625 	if (!mrt)
1626 		return -ENOENT;
1627 
1628 	switch (cmd) {
1629 	case SIOCGETVIFCNT:
1630 		if (copy_from_user(&vr, arg, sizeof(vr)))
1631 			return -EFAULT;
1632 		if (vr.vifi >= mrt->maxvif)
1633 			return -EINVAL;
1634 		vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif);
1635 		read_lock(&mrt_lock);
1636 		vif = &mrt->vif_table[vr.vifi];
1637 		if (VIF_EXISTS(mrt, vr.vifi)) {
1638 			vr.icount = vif->pkt_in;
1639 			vr.ocount = vif->pkt_out;
1640 			vr.ibytes = vif->bytes_in;
1641 			vr.obytes = vif->bytes_out;
1642 			read_unlock(&mrt_lock);
1643 
1644 			if (copy_to_user(arg, &vr, sizeof(vr)))
1645 				return -EFAULT;
1646 			return 0;
1647 		}
1648 		read_unlock(&mrt_lock);
1649 		return -EADDRNOTAVAIL;
1650 	case SIOCGETSGCNT:
1651 		if (copy_from_user(&sr, arg, sizeof(sr)))
1652 			return -EFAULT;
1653 
1654 		rcu_read_lock();
1655 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1656 		if (c) {
1657 			sr.pktcnt = c->_c.mfc_un.res.pkt;
1658 			sr.bytecnt = c->_c.mfc_un.res.bytes;
1659 			sr.wrong_if = c->_c.mfc_un.res.wrong_if;
1660 			rcu_read_unlock();
1661 
1662 			if (copy_to_user(arg, &sr, sizeof(sr)))
1663 				return -EFAULT;
1664 			return 0;
1665 		}
1666 		rcu_read_unlock();
1667 		return -EADDRNOTAVAIL;
1668 	default:
1669 		return -ENOIOCTLCMD;
1670 	}
1671 }
1672 
1673 #ifdef CONFIG_COMPAT
1674 struct compat_sioc_sg_req {
1675 	struct in_addr src;
1676 	struct in_addr grp;
1677 	compat_ulong_t pktcnt;
1678 	compat_ulong_t bytecnt;
1679 	compat_ulong_t wrong_if;
1680 };
1681 
1682 struct compat_sioc_vif_req {
1683 	vifi_t	vifi;		/* Which iface */
1684 	compat_ulong_t icount;
1685 	compat_ulong_t ocount;
1686 	compat_ulong_t ibytes;
1687 	compat_ulong_t obytes;
1688 };
1689 
1690 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1691 {
1692 	struct compat_sioc_sg_req sr;
1693 	struct compat_sioc_vif_req vr;
1694 	struct vif_device *vif;
1695 	struct mfc_cache *c;
1696 	struct net *net = sock_net(sk);
1697 	struct mr_table *mrt;
1698 
1699 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1700 	if (!mrt)
1701 		return -ENOENT;
1702 
1703 	switch (cmd) {
1704 	case SIOCGETVIFCNT:
1705 		if (copy_from_user(&vr, arg, sizeof(vr)))
1706 			return -EFAULT;
1707 		if (vr.vifi >= mrt->maxvif)
1708 			return -EINVAL;
1709 		vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif);
1710 		read_lock(&mrt_lock);
1711 		vif = &mrt->vif_table[vr.vifi];
1712 		if (VIF_EXISTS(mrt, vr.vifi)) {
1713 			vr.icount = vif->pkt_in;
1714 			vr.ocount = vif->pkt_out;
1715 			vr.ibytes = vif->bytes_in;
1716 			vr.obytes = vif->bytes_out;
1717 			read_unlock(&mrt_lock);
1718 
1719 			if (copy_to_user(arg, &vr, sizeof(vr)))
1720 				return -EFAULT;
1721 			return 0;
1722 		}
1723 		read_unlock(&mrt_lock);
1724 		return -EADDRNOTAVAIL;
1725 	case SIOCGETSGCNT:
1726 		if (copy_from_user(&sr, arg, sizeof(sr)))
1727 			return -EFAULT;
1728 
1729 		rcu_read_lock();
1730 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1731 		if (c) {
1732 			sr.pktcnt = c->_c.mfc_un.res.pkt;
1733 			sr.bytecnt = c->_c.mfc_un.res.bytes;
1734 			sr.wrong_if = c->_c.mfc_un.res.wrong_if;
1735 			rcu_read_unlock();
1736 
1737 			if (copy_to_user(arg, &sr, sizeof(sr)))
1738 				return -EFAULT;
1739 			return 0;
1740 		}
1741 		rcu_read_unlock();
1742 		return -EADDRNOTAVAIL;
1743 	default:
1744 		return -ENOIOCTLCMD;
1745 	}
1746 }
1747 #endif
1748 
1749 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1750 {
1751 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1752 	struct net *net = dev_net(dev);
1753 	struct mr_table *mrt;
1754 	struct vif_device *v;
1755 	int ct;
1756 
1757 	if (event != NETDEV_UNREGISTER)
1758 		return NOTIFY_DONE;
1759 
1760 	ipmr_for_each_table(mrt, net) {
1761 		v = &mrt->vif_table[0];
1762 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1763 			if (v->dev == dev)
1764 				vif_delete(mrt, ct, 1, NULL);
1765 		}
1766 	}
1767 	return NOTIFY_DONE;
1768 }
1769 
1770 static struct notifier_block ip_mr_notifier = {
1771 	.notifier_call = ipmr_device_event,
1772 };
1773 
1774 /* Encapsulate a packet by attaching a valid IPIP header to it.
1775  * This avoids tunnel drivers and other mess and gives us the speed so
1776  * important for multicast video.
1777  */
1778 static void ip_encap(struct net *net, struct sk_buff *skb,
1779 		     __be32 saddr, __be32 daddr)
1780 {
1781 	struct iphdr *iph;
1782 	const struct iphdr *old_iph = ip_hdr(skb);
1783 
1784 	skb_push(skb, sizeof(struct iphdr));
1785 	skb->transport_header = skb->network_header;
1786 	skb_reset_network_header(skb);
1787 	iph = ip_hdr(skb);
1788 
1789 	iph->version	=	4;
1790 	iph->tos	=	old_iph->tos;
1791 	iph->ttl	=	old_iph->ttl;
1792 	iph->frag_off	=	0;
1793 	iph->daddr	=	daddr;
1794 	iph->saddr	=	saddr;
1795 	iph->protocol	=	IPPROTO_IPIP;
1796 	iph->ihl	=	5;
1797 	iph->tot_len	=	htons(skb->len);
1798 	ip_select_ident(net, skb, NULL);
1799 	ip_send_check(iph);
1800 
1801 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1802 	nf_reset(skb);
1803 }
1804 
1805 static inline int ipmr_forward_finish(struct net *net, struct sock *sk,
1806 				      struct sk_buff *skb)
1807 {
1808 	struct ip_options *opt = &(IPCB(skb)->opt);
1809 
1810 	IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
1811 	IP_ADD_STATS(net, IPSTATS_MIB_OUTOCTETS, skb->len);
1812 
1813 	if (unlikely(opt->optlen))
1814 		ip_forward_options(skb);
1815 
1816 	return dst_output(net, sk, skb);
1817 }
1818 
1819 #ifdef CONFIG_NET_SWITCHDEV
1820 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1821 				   int in_vifi, int out_vifi)
1822 {
1823 	struct vif_device *out_vif = &mrt->vif_table[out_vifi];
1824 	struct vif_device *in_vif = &mrt->vif_table[in_vifi];
1825 
1826 	if (!skb->offload_l3_fwd_mark)
1827 		return false;
1828 	if (!out_vif->dev_parent_id.id_len || !in_vif->dev_parent_id.id_len)
1829 		return false;
1830 	return netdev_phys_item_id_same(&out_vif->dev_parent_id,
1831 					&in_vif->dev_parent_id);
1832 }
1833 #else
1834 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1835 				   int in_vifi, int out_vifi)
1836 {
1837 	return false;
1838 }
1839 #endif
1840 
1841 /* Processing handlers for ipmr_forward */
1842 
1843 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1844 			    int in_vifi, struct sk_buff *skb, int vifi)
1845 {
1846 	const struct iphdr *iph = ip_hdr(skb);
1847 	struct vif_device *vif = &mrt->vif_table[vifi];
1848 	struct net_device *dev;
1849 	struct rtable *rt;
1850 	struct flowi4 fl4;
1851 	int    encap = 0;
1852 
1853 	if (!vif->dev)
1854 		goto out_free;
1855 
1856 	if (vif->flags & VIFF_REGISTER) {
1857 		vif->pkt_out++;
1858 		vif->bytes_out += skb->len;
1859 		vif->dev->stats.tx_bytes += skb->len;
1860 		vif->dev->stats.tx_packets++;
1861 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1862 		goto out_free;
1863 	}
1864 
1865 	if (ipmr_forward_offloaded(skb, mrt, in_vifi, vifi))
1866 		goto out_free;
1867 
1868 	if (vif->flags & VIFF_TUNNEL) {
1869 		rt = ip_route_output_ports(net, &fl4, NULL,
1870 					   vif->remote, vif->local,
1871 					   0, 0,
1872 					   IPPROTO_IPIP,
1873 					   RT_TOS(iph->tos), vif->link);
1874 		if (IS_ERR(rt))
1875 			goto out_free;
1876 		encap = sizeof(struct iphdr);
1877 	} else {
1878 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1879 					   0, 0,
1880 					   IPPROTO_IPIP,
1881 					   RT_TOS(iph->tos), vif->link);
1882 		if (IS_ERR(rt))
1883 			goto out_free;
1884 	}
1885 
1886 	dev = rt->dst.dev;
1887 
1888 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1889 		/* Do not fragment multicasts. Alas, IPv4 does not
1890 		 * allow to send ICMP, so that packets will disappear
1891 		 * to blackhole.
1892 		 */
1893 		IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
1894 		ip_rt_put(rt);
1895 		goto out_free;
1896 	}
1897 
1898 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1899 
1900 	if (skb_cow(skb, encap)) {
1901 		ip_rt_put(rt);
1902 		goto out_free;
1903 	}
1904 
1905 	vif->pkt_out++;
1906 	vif->bytes_out += skb->len;
1907 
1908 	skb_dst_drop(skb);
1909 	skb_dst_set(skb, &rt->dst);
1910 	ip_decrease_ttl(ip_hdr(skb));
1911 
1912 	/* FIXME: forward and output firewalls used to be called here.
1913 	 * What do we do with netfilter? -- RR
1914 	 */
1915 	if (vif->flags & VIFF_TUNNEL) {
1916 		ip_encap(net, skb, vif->local, vif->remote);
1917 		/* FIXME: extra output firewall step used to be here. --RR */
1918 		vif->dev->stats.tx_packets++;
1919 		vif->dev->stats.tx_bytes += skb->len;
1920 	}
1921 
1922 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1923 
1924 	/* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1925 	 * not only before forwarding, but after forwarding on all output
1926 	 * interfaces. It is clear, if mrouter runs a multicasting
1927 	 * program, it should receive packets not depending to what interface
1928 	 * program is joined.
1929 	 * If we will not make it, the program will have to join on all
1930 	 * interfaces. On the other hand, multihoming host (or router, but
1931 	 * not mrouter) cannot join to more than one interface - it will
1932 	 * result in receiving multiple packets.
1933 	 */
1934 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
1935 		net, NULL, skb, skb->dev, dev,
1936 		ipmr_forward_finish);
1937 	return;
1938 
1939 out_free:
1940 	kfree_skb(skb);
1941 }
1942 
1943 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1944 {
1945 	int ct;
1946 
1947 	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1948 		if (mrt->vif_table[ct].dev == dev)
1949 			break;
1950 	}
1951 	return ct;
1952 }
1953 
1954 /* "local" means that we should preserve one skb (for local delivery) */
1955 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
1956 			  struct net_device *dev, struct sk_buff *skb,
1957 			  struct mfc_cache *c, int local)
1958 {
1959 	int true_vifi = ipmr_find_vif(mrt, dev);
1960 	int psend = -1;
1961 	int vif, ct;
1962 
1963 	vif = c->_c.mfc_parent;
1964 	c->_c.mfc_un.res.pkt++;
1965 	c->_c.mfc_un.res.bytes += skb->len;
1966 	c->_c.mfc_un.res.lastuse = jiffies;
1967 
1968 	if (c->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
1969 		struct mfc_cache *cache_proxy;
1970 
1971 		/* For an (*,G) entry, we only check that the incomming
1972 		 * interface is part of the static tree.
1973 		 */
1974 		cache_proxy = mr_mfc_find_any_parent(mrt, vif);
1975 		if (cache_proxy &&
1976 		    cache_proxy->_c.mfc_un.res.ttls[true_vifi] < 255)
1977 			goto forward;
1978 	}
1979 
1980 	/* Wrong interface: drop packet and (maybe) send PIM assert. */
1981 	if (mrt->vif_table[vif].dev != dev) {
1982 		if (rt_is_output_route(skb_rtable(skb))) {
1983 			/* It is our own packet, looped back.
1984 			 * Very complicated situation...
1985 			 *
1986 			 * The best workaround until routing daemons will be
1987 			 * fixed is not to redistribute packet, if it was
1988 			 * send through wrong interface. It means, that
1989 			 * multicast applications WILL NOT work for
1990 			 * (S,G), which have default multicast route pointing
1991 			 * to wrong oif. In any case, it is not a good
1992 			 * idea to use multicasting applications on router.
1993 			 */
1994 			goto dont_forward;
1995 		}
1996 
1997 		c->_c.mfc_un.res.wrong_if++;
1998 
1999 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
2000 		    /* pimsm uses asserts, when switching from RPT to SPT,
2001 		     * so that we cannot check that packet arrived on an oif.
2002 		     * It is bad, but otherwise we would need to move pretty
2003 		     * large chunk of pimd to kernel. Ough... --ANK
2004 		     */
2005 		    (mrt->mroute_do_pim ||
2006 		     c->_c.mfc_un.res.ttls[true_vifi] < 255) &&
2007 		    time_after(jiffies,
2008 			       c->_c.mfc_un.res.last_assert +
2009 			       MFC_ASSERT_THRESH)) {
2010 			c->_c.mfc_un.res.last_assert = jiffies;
2011 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
2012 			if (mrt->mroute_do_wrvifwhole)
2013 				ipmr_cache_report(mrt, skb, true_vifi,
2014 						  IGMPMSG_WRVIFWHOLE);
2015 		}
2016 		goto dont_forward;
2017 	}
2018 
2019 forward:
2020 	mrt->vif_table[vif].pkt_in++;
2021 	mrt->vif_table[vif].bytes_in += skb->len;
2022 
2023 	/* Forward the frame */
2024 	if (c->mfc_origin == htonl(INADDR_ANY) &&
2025 	    c->mfc_mcastgrp == htonl(INADDR_ANY)) {
2026 		if (true_vifi >= 0 &&
2027 		    true_vifi != c->_c.mfc_parent &&
2028 		    ip_hdr(skb)->ttl >
2029 				c->_c.mfc_un.res.ttls[c->_c.mfc_parent]) {
2030 			/* It's an (*,*) entry and the packet is not coming from
2031 			 * the upstream: forward the packet to the upstream
2032 			 * only.
2033 			 */
2034 			psend = c->_c.mfc_parent;
2035 			goto last_forward;
2036 		}
2037 		goto dont_forward;
2038 	}
2039 	for (ct = c->_c.mfc_un.res.maxvif - 1;
2040 	     ct >= c->_c.mfc_un.res.minvif; ct--) {
2041 		/* For (*,G) entry, don't forward to the incoming interface */
2042 		if ((c->mfc_origin != htonl(INADDR_ANY) ||
2043 		     ct != true_vifi) &&
2044 		    ip_hdr(skb)->ttl > c->_c.mfc_un.res.ttls[ct]) {
2045 			if (psend != -1) {
2046 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2047 
2048 				if (skb2)
2049 					ipmr_queue_xmit(net, mrt, true_vifi,
2050 							skb2, psend);
2051 			}
2052 			psend = ct;
2053 		}
2054 	}
2055 last_forward:
2056 	if (psend != -1) {
2057 		if (local) {
2058 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2059 
2060 			if (skb2)
2061 				ipmr_queue_xmit(net, mrt, true_vifi, skb2,
2062 						psend);
2063 		} else {
2064 			ipmr_queue_xmit(net, mrt, true_vifi, skb, psend);
2065 			return;
2066 		}
2067 	}
2068 
2069 dont_forward:
2070 	if (!local)
2071 		kfree_skb(skb);
2072 }
2073 
2074 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
2075 {
2076 	struct rtable *rt = skb_rtable(skb);
2077 	struct iphdr *iph = ip_hdr(skb);
2078 	struct flowi4 fl4 = {
2079 		.daddr = iph->daddr,
2080 		.saddr = iph->saddr,
2081 		.flowi4_tos = RT_TOS(iph->tos),
2082 		.flowi4_oif = (rt_is_output_route(rt) ?
2083 			       skb->dev->ifindex : 0),
2084 		.flowi4_iif = (rt_is_output_route(rt) ?
2085 			       LOOPBACK_IFINDEX :
2086 			       skb->dev->ifindex),
2087 		.flowi4_mark = skb->mark,
2088 	};
2089 	struct mr_table *mrt;
2090 	int err;
2091 
2092 	err = ipmr_fib_lookup(net, &fl4, &mrt);
2093 	if (err)
2094 		return ERR_PTR(err);
2095 	return mrt;
2096 }
2097 
2098 /* Multicast packets for forwarding arrive here
2099  * Called with rcu_read_lock();
2100  */
2101 int ip_mr_input(struct sk_buff *skb)
2102 {
2103 	struct mfc_cache *cache;
2104 	struct net *net = dev_net(skb->dev);
2105 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
2106 	struct mr_table *mrt;
2107 	struct net_device *dev;
2108 
2109 	/* skb->dev passed in is the loX master dev for vrfs.
2110 	 * As there are no vifs associated with loopback devices,
2111 	 * get the proper interface that does have a vif associated with it.
2112 	 */
2113 	dev = skb->dev;
2114 	if (netif_is_l3_master(skb->dev)) {
2115 		dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
2116 		if (!dev) {
2117 			kfree_skb(skb);
2118 			return -ENODEV;
2119 		}
2120 	}
2121 
2122 	/* Packet is looped back after forward, it should not be
2123 	 * forwarded second time, but still can be delivered locally.
2124 	 */
2125 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
2126 		goto dont_forward;
2127 
2128 	mrt = ipmr_rt_fib_lookup(net, skb);
2129 	if (IS_ERR(mrt)) {
2130 		kfree_skb(skb);
2131 		return PTR_ERR(mrt);
2132 	}
2133 	if (!local) {
2134 		if (IPCB(skb)->opt.router_alert) {
2135 			if (ip_call_ra_chain(skb))
2136 				return 0;
2137 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
2138 			/* IGMPv1 (and broken IGMPv2 implementations sort of
2139 			 * Cisco IOS <= 11.2(8)) do not put router alert
2140 			 * option to IGMP packets destined to routable
2141 			 * groups. It is very bad, because it means
2142 			 * that we can forward NO IGMP messages.
2143 			 */
2144 			struct sock *mroute_sk;
2145 
2146 			mroute_sk = rcu_dereference(mrt->mroute_sk);
2147 			if (mroute_sk) {
2148 				nf_reset(skb);
2149 				raw_rcv(mroute_sk, skb);
2150 				return 0;
2151 			}
2152 		    }
2153 	}
2154 
2155 	/* already under rcu_read_lock() */
2156 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
2157 	if (!cache) {
2158 		int vif = ipmr_find_vif(mrt, dev);
2159 
2160 		if (vif >= 0)
2161 			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
2162 						    vif);
2163 	}
2164 
2165 	/* No usable cache entry */
2166 	if (!cache) {
2167 		int vif;
2168 
2169 		if (local) {
2170 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2171 			ip_local_deliver(skb);
2172 			if (!skb2)
2173 				return -ENOBUFS;
2174 			skb = skb2;
2175 		}
2176 
2177 		read_lock(&mrt_lock);
2178 		vif = ipmr_find_vif(mrt, dev);
2179 		if (vif >= 0) {
2180 			int err2 = ipmr_cache_unresolved(mrt, vif, skb, dev);
2181 			read_unlock(&mrt_lock);
2182 
2183 			return err2;
2184 		}
2185 		read_unlock(&mrt_lock);
2186 		kfree_skb(skb);
2187 		return -ENODEV;
2188 	}
2189 
2190 	read_lock(&mrt_lock);
2191 	ip_mr_forward(net, mrt, dev, skb, cache, local);
2192 	read_unlock(&mrt_lock);
2193 
2194 	if (local)
2195 		return ip_local_deliver(skb);
2196 
2197 	return 0;
2198 
2199 dont_forward:
2200 	if (local)
2201 		return ip_local_deliver(skb);
2202 	kfree_skb(skb);
2203 	return 0;
2204 }
2205 
2206 #ifdef CONFIG_IP_PIMSM_V1
2207 /* Handle IGMP messages of PIMv1 */
2208 int pim_rcv_v1(struct sk_buff *skb)
2209 {
2210 	struct igmphdr *pim;
2211 	struct net *net = dev_net(skb->dev);
2212 	struct mr_table *mrt;
2213 
2214 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2215 		goto drop;
2216 
2217 	pim = igmp_hdr(skb);
2218 
2219 	mrt = ipmr_rt_fib_lookup(net, skb);
2220 	if (IS_ERR(mrt))
2221 		goto drop;
2222 	if (!mrt->mroute_do_pim ||
2223 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2224 		goto drop;
2225 
2226 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2227 drop:
2228 		kfree_skb(skb);
2229 	}
2230 	return 0;
2231 }
2232 #endif
2233 
2234 #ifdef CONFIG_IP_PIMSM_V2
2235 static int pim_rcv(struct sk_buff *skb)
2236 {
2237 	struct pimreghdr *pim;
2238 	struct net *net = dev_net(skb->dev);
2239 	struct mr_table *mrt;
2240 
2241 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2242 		goto drop;
2243 
2244 	pim = (struct pimreghdr *)skb_transport_header(skb);
2245 	if (pim->type != ((PIM_VERSION << 4) | (PIM_TYPE_REGISTER)) ||
2246 	    (pim->flags & PIM_NULL_REGISTER) ||
2247 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2248 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2249 		goto drop;
2250 
2251 	mrt = ipmr_rt_fib_lookup(net, skb);
2252 	if (IS_ERR(mrt))
2253 		goto drop;
2254 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2255 drop:
2256 		kfree_skb(skb);
2257 	}
2258 	return 0;
2259 }
2260 #endif
2261 
2262 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2263 		   __be32 saddr, __be32 daddr,
2264 		   struct rtmsg *rtm, u32 portid)
2265 {
2266 	struct mfc_cache *cache;
2267 	struct mr_table *mrt;
2268 	int err;
2269 
2270 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2271 	if (!mrt)
2272 		return -ENOENT;
2273 
2274 	rcu_read_lock();
2275 	cache = ipmr_cache_find(mrt, saddr, daddr);
2276 	if (!cache && skb->dev) {
2277 		int vif = ipmr_find_vif(mrt, skb->dev);
2278 
2279 		if (vif >= 0)
2280 			cache = ipmr_cache_find_any(mrt, daddr, vif);
2281 	}
2282 	if (!cache) {
2283 		struct sk_buff *skb2;
2284 		struct iphdr *iph;
2285 		struct net_device *dev;
2286 		int vif = -1;
2287 
2288 		dev = skb->dev;
2289 		read_lock(&mrt_lock);
2290 		if (dev)
2291 			vif = ipmr_find_vif(mrt, dev);
2292 		if (vif < 0) {
2293 			read_unlock(&mrt_lock);
2294 			rcu_read_unlock();
2295 			return -ENODEV;
2296 		}
2297 		skb2 = skb_clone(skb, GFP_ATOMIC);
2298 		if (!skb2) {
2299 			read_unlock(&mrt_lock);
2300 			rcu_read_unlock();
2301 			return -ENOMEM;
2302 		}
2303 
2304 		NETLINK_CB(skb2).portid = portid;
2305 		skb_push(skb2, sizeof(struct iphdr));
2306 		skb_reset_network_header(skb2);
2307 		iph = ip_hdr(skb2);
2308 		iph->ihl = sizeof(struct iphdr) >> 2;
2309 		iph->saddr = saddr;
2310 		iph->daddr = daddr;
2311 		iph->version = 0;
2312 		err = ipmr_cache_unresolved(mrt, vif, skb2, dev);
2313 		read_unlock(&mrt_lock);
2314 		rcu_read_unlock();
2315 		return err;
2316 	}
2317 
2318 	read_lock(&mrt_lock);
2319 	err = mr_fill_mroute(mrt, skb, &cache->_c, rtm);
2320 	read_unlock(&mrt_lock);
2321 	rcu_read_unlock();
2322 	return err;
2323 }
2324 
2325 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2326 			    u32 portid, u32 seq, struct mfc_cache *c, int cmd,
2327 			    int flags)
2328 {
2329 	struct nlmsghdr *nlh;
2330 	struct rtmsg *rtm;
2331 	int err;
2332 
2333 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2334 	if (!nlh)
2335 		return -EMSGSIZE;
2336 
2337 	rtm = nlmsg_data(nlh);
2338 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2339 	rtm->rtm_dst_len  = 32;
2340 	rtm->rtm_src_len  = 32;
2341 	rtm->rtm_tos      = 0;
2342 	rtm->rtm_table    = mrt->id;
2343 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2344 		goto nla_put_failure;
2345 	rtm->rtm_type     = RTN_MULTICAST;
2346 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2347 	if (c->_c.mfc_flags & MFC_STATIC)
2348 		rtm->rtm_protocol = RTPROT_STATIC;
2349 	else
2350 		rtm->rtm_protocol = RTPROT_MROUTED;
2351 	rtm->rtm_flags    = 0;
2352 
2353 	if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
2354 	    nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
2355 		goto nla_put_failure;
2356 	err = mr_fill_mroute(mrt, skb, &c->_c, rtm);
2357 	/* do not break the dump if cache is unresolved */
2358 	if (err < 0 && err != -ENOENT)
2359 		goto nla_put_failure;
2360 
2361 	nlmsg_end(skb, nlh);
2362 	return 0;
2363 
2364 nla_put_failure:
2365 	nlmsg_cancel(skb, nlh);
2366 	return -EMSGSIZE;
2367 }
2368 
2369 static int _ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2370 			     u32 portid, u32 seq, struct mr_mfc *c, int cmd,
2371 			     int flags)
2372 {
2373 	return ipmr_fill_mroute(mrt, skb, portid, seq, (struct mfc_cache *)c,
2374 				cmd, flags);
2375 }
2376 
2377 static size_t mroute_msgsize(bool unresolved, int maxvif)
2378 {
2379 	size_t len =
2380 		NLMSG_ALIGN(sizeof(struct rtmsg))
2381 		+ nla_total_size(4)	/* RTA_TABLE */
2382 		+ nla_total_size(4)	/* RTA_SRC */
2383 		+ nla_total_size(4)	/* RTA_DST */
2384 		;
2385 
2386 	if (!unresolved)
2387 		len = len
2388 		      + nla_total_size(4)	/* RTA_IIF */
2389 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2390 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2391 						/* RTA_MFC_STATS */
2392 		      + nla_total_size_64bit(sizeof(struct rta_mfc_stats))
2393 		;
2394 
2395 	return len;
2396 }
2397 
2398 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2399 				 int cmd)
2400 {
2401 	struct net *net = read_pnet(&mrt->net);
2402 	struct sk_buff *skb;
2403 	int err = -ENOBUFS;
2404 
2405 	skb = nlmsg_new(mroute_msgsize(mfc->_c.mfc_parent >= MAXVIFS,
2406 				       mrt->maxvif),
2407 			GFP_ATOMIC);
2408 	if (!skb)
2409 		goto errout;
2410 
2411 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2412 	if (err < 0)
2413 		goto errout;
2414 
2415 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2416 	return;
2417 
2418 errout:
2419 	kfree_skb(skb);
2420 	if (err < 0)
2421 		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2422 }
2423 
2424 static size_t igmpmsg_netlink_msgsize(size_t payloadlen)
2425 {
2426 	size_t len =
2427 		NLMSG_ALIGN(sizeof(struct rtgenmsg))
2428 		+ nla_total_size(1)	/* IPMRA_CREPORT_MSGTYPE */
2429 		+ nla_total_size(4)	/* IPMRA_CREPORT_VIF_ID */
2430 		+ nla_total_size(4)	/* IPMRA_CREPORT_SRC_ADDR */
2431 		+ nla_total_size(4)	/* IPMRA_CREPORT_DST_ADDR */
2432 					/* IPMRA_CREPORT_PKT */
2433 		+ nla_total_size(payloadlen)
2434 		;
2435 
2436 	return len;
2437 }
2438 
2439 static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt)
2440 {
2441 	struct net *net = read_pnet(&mrt->net);
2442 	struct nlmsghdr *nlh;
2443 	struct rtgenmsg *rtgenm;
2444 	struct igmpmsg *msg;
2445 	struct sk_buff *skb;
2446 	struct nlattr *nla;
2447 	int payloadlen;
2448 
2449 	payloadlen = pkt->len - sizeof(struct igmpmsg);
2450 	msg = (struct igmpmsg *)skb_network_header(pkt);
2451 
2452 	skb = nlmsg_new(igmpmsg_netlink_msgsize(payloadlen), GFP_ATOMIC);
2453 	if (!skb)
2454 		goto errout;
2455 
2456 	nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT,
2457 			sizeof(struct rtgenmsg), 0);
2458 	if (!nlh)
2459 		goto errout;
2460 	rtgenm = nlmsg_data(nlh);
2461 	rtgenm->rtgen_family = RTNL_FAMILY_IPMR;
2462 	if (nla_put_u8(skb, IPMRA_CREPORT_MSGTYPE, msg->im_msgtype) ||
2463 	    nla_put_u32(skb, IPMRA_CREPORT_VIF_ID, msg->im_vif) ||
2464 	    nla_put_in_addr(skb, IPMRA_CREPORT_SRC_ADDR,
2465 			    msg->im_src.s_addr) ||
2466 	    nla_put_in_addr(skb, IPMRA_CREPORT_DST_ADDR,
2467 			    msg->im_dst.s_addr))
2468 		goto nla_put_failure;
2469 
2470 	nla = nla_reserve(skb, IPMRA_CREPORT_PKT, payloadlen);
2471 	if (!nla || skb_copy_bits(pkt, sizeof(struct igmpmsg),
2472 				  nla_data(nla), payloadlen))
2473 		goto nla_put_failure;
2474 
2475 	nlmsg_end(skb, nlh);
2476 
2477 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE_R, NULL, GFP_ATOMIC);
2478 	return;
2479 
2480 nla_put_failure:
2481 	nlmsg_cancel(skb, nlh);
2482 errout:
2483 	kfree_skb(skb);
2484 	rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE_R, -ENOBUFS);
2485 }
2486 
2487 static int ipmr_rtm_valid_getroute_req(struct sk_buff *skb,
2488 				       const struct nlmsghdr *nlh,
2489 				       struct nlattr **tb,
2490 				       struct netlink_ext_ack *extack)
2491 {
2492 	struct rtmsg *rtm;
2493 	int i, err;
2494 
2495 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2496 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for multicast route get request");
2497 		return -EINVAL;
2498 	}
2499 
2500 	if (!netlink_strict_get_check(skb))
2501 		return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
2502 					      rtm_ipv4_policy, extack);
2503 
2504 	rtm = nlmsg_data(nlh);
2505 	if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
2506 	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
2507 	    rtm->rtm_tos || rtm->rtm_table || rtm->rtm_protocol ||
2508 	    rtm->rtm_scope || rtm->rtm_type || rtm->rtm_flags) {
2509 		NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for multicast route get request");
2510 		return -EINVAL;
2511 	}
2512 
2513 	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2514 					    rtm_ipv4_policy, extack);
2515 	if (err)
2516 		return err;
2517 
2518 	if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
2519 	    (tb[RTA_DST] && !rtm->rtm_dst_len)) {
2520 		NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
2521 		return -EINVAL;
2522 	}
2523 
2524 	for (i = 0; i <= RTA_MAX; i++) {
2525 		if (!tb[i])
2526 			continue;
2527 
2528 		switch (i) {
2529 		case RTA_SRC:
2530 		case RTA_DST:
2531 		case RTA_TABLE:
2532 			break;
2533 		default:
2534 			NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in multicast route get request");
2535 			return -EINVAL;
2536 		}
2537 	}
2538 
2539 	return 0;
2540 }
2541 
2542 static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2543 			     struct netlink_ext_ack *extack)
2544 {
2545 	struct net *net = sock_net(in_skb->sk);
2546 	struct nlattr *tb[RTA_MAX + 1];
2547 	struct sk_buff *skb = NULL;
2548 	struct mfc_cache *cache;
2549 	struct mr_table *mrt;
2550 	__be32 src, grp;
2551 	u32 tableid;
2552 	int err;
2553 
2554 	err = ipmr_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
2555 	if (err < 0)
2556 		goto errout;
2557 
2558 	src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2559 	grp = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2560 	tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0;
2561 
2562 	mrt = ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT);
2563 	if (!mrt) {
2564 		err = -ENOENT;
2565 		goto errout_free;
2566 	}
2567 
2568 	/* entries are added/deleted only under RTNL */
2569 	rcu_read_lock();
2570 	cache = ipmr_cache_find(mrt, src, grp);
2571 	rcu_read_unlock();
2572 	if (!cache) {
2573 		err = -ENOENT;
2574 		goto errout_free;
2575 	}
2576 
2577 	skb = nlmsg_new(mroute_msgsize(false, mrt->maxvif), GFP_KERNEL);
2578 	if (!skb) {
2579 		err = -ENOBUFS;
2580 		goto errout_free;
2581 	}
2582 
2583 	err = ipmr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid,
2584 			       nlh->nlmsg_seq, cache,
2585 			       RTM_NEWROUTE, 0);
2586 	if (err < 0)
2587 		goto errout_free;
2588 
2589 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2590 
2591 errout:
2592 	return err;
2593 
2594 errout_free:
2595 	kfree_skb(skb);
2596 	goto errout;
2597 }
2598 
2599 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2600 {
2601 	struct fib_dump_filter filter = {};
2602 	int err;
2603 
2604 	if (cb->strict_check) {
2605 		err = ip_valid_fib_dump_req(sock_net(skb->sk), cb->nlh,
2606 					    &filter, cb);
2607 		if (err < 0)
2608 			return err;
2609 	}
2610 
2611 	if (filter.table_id) {
2612 		struct mr_table *mrt;
2613 
2614 		mrt = ipmr_get_table(sock_net(skb->sk), filter.table_id);
2615 		if (!mrt) {
2616 			if (filter.dump_all_families)
2617 				return skb->len;
2618 
2619 			NL_SET_ERR_MSG(cb->extack, "ipv4: MR table does not exist");
2620 			return -ENOENT;
2621 		}
2622 		err = mr_table_dump(mrt, skb, cb, _ipmr_fill_mroute,
2623 				    &mfc_unres_lock, &filter);
2624 		return skb->len ? : err;
2625 	}
2626 
2627 	return mr_rtm_dumproute(skb, cb, ipmr_mr_table_iter,
2628 				_ipmr_fill_mroute, &mfc_unres_lock, &filter);
2629 }
2630 
2631 static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {
2632 	[RTA_SRC]	= { .type = NLA_U32 },
2633 	[RTA_DST]	= { .type = NLA_U32 },
2634 	[RTA_IIF]	= { .type = NLA_U32 },
2635 	[RTA_TABLE]	= { .type = NLA_U32 },
2636 	[RTA_MULTIPATH]	= { .len = sizeof(struct rtnexthop) },
2637 };
2638 
2639 static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol)
2640 {
2641 	switch (rtm_protocol) {
2642 	case RTPROT_STATIC:
2643 	case RTPROT_MROUTED:
2644 		return true;
2645 	}
2646 	return false;
2647 }
2648 
2649 static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc)
2650 {
2651 	struct rtnexthop *rtnh = nla_data(nla);
2652 	int remaining = nla_len(nla), vifi = 0;
2653 
2654 	while (rtnh_ok(rtnh, remaining)) {
2655 		mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops;
2656 		if (++vifi == MAXVIFS)
2657 			break;
2658 		rtnh = rtnh_next(rtnh, &remaining);
2659 	}
2660 
2661 	return remaining > 0 ? -EINVAL : vifi;
2662 }
2663 
2664 /* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */
2665 static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
2666 			    struct mfcctl *mfcc, int *mrtsock,
2667 			    struct mr_table **mrtret,
2668 			    struct netlink_ext_ack *extack)
2669 {
2670 	struct net_device *dev = NULL;
2671 	u32 tblid = RT_TABLE_DEFAULT;
2672 	struct mr_table *mrt;
2673 	struct nlattr *attr;
2674 	struct rtmsg *rtm;
2675 	int ret, rem;
2676 
2677 	ret = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
2678 					rtm_ipmr_policy, extack);
2679 	if (ret < 0)
2680 		goto out;
2681 	rtm = nlmsg_data(nlh);
2682 
2683 	ret = -EINVAL;
2684 	if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 ||
2685 	    rtm->rtm_type != RTN_MULTICAST ||
2686 	    rtm->rtm_scope != RT_SCOPE_UNIVERSE ||
2687 	    !ipmr_rtm_validate_proto(rtm->rtm_protocol))
2688 		goto out;
2689 
2690 	memset(mfcc, 0, sizeof(*mfcc));
2691 	mfcc->mfcc_parent = -1;
2692 	ret = 0;
2693 	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) {
2694 		switch (nla_type(attr)) {
2695 		case RTA_SRC:
2696 			mfcc->mfcc_origin.s_addr = nla_get_be32(attr);
2697 			break;
2698 		case RTA_DST:
2699 			mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr);
2700 			break;
2701 		case RTA_IIF:
2702 			dev = __dev_get_by_index(net, nla_get_u32(attr));
2703 			if (!dev) {
2704 				ret = -ENODEV;
2705 				goto out;
2706 			}
2707 			break;
2708 		case RTA_MULTIPATH:
2709 			if (ipmr_nla_get_ttls(attr, mfcc) < 0) {
2710 				ret = -EINVAL;
2711 				goto out;
2712 			}
2713 			break;
2714 		case RTA_PREFSRC:
2715 			ret = 1;
2716 			break;
2717 		case RTA_TABLE:
2718 			tblid = nla_get_u32(attr);
2719 			break;
2720 		}
2721 	}
2722 	mrt = ipmr_get_table(net, tblid);
2723 	if (!mrt) {
2724 		ret = -ENOENT;
2725 		goto out;
2726 	}
2727 	*mrtret = mrt;
2728 	*mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0;
2729 	if (dev)
2730 		mfcc->mfcc_parent = ipmr_find_vif(mrt, dev);
2731 
2732 out:
2733 	return ret;
2734 }
2735 
2736 /* takes care of both newroute and delroute */
2737 static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh,
2738 			  struct netlink_ext_ack *extack)
2739 {
2740 	struct net *net = sock_net(skb->sk);
2741 	int ret, mrtsock, parent;
2742 	struct mr_table *tbl;
2743 	struct mfcctl mfcc;
2744 
2745 	mrtsock = 0;
2746 	tbl = NULL;
2747 	ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl, extack);
2748 	if (ret < 0)
2749 		return ret;
2750 
2751 	parent = ret ? mfcc.mfcc_parent : -1;
2752 	if (nlh->nlmsg_type == RTM_NEWROUTE)
2753 		return ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent);
2754 	else
2755 		return ipmr_mfc_delete(tbl, &mfcc, parent);
2756 }
2757 
2758 static bool ipmr_fill_table(struct mr_table *mrt, struct sk_buff *skb)
2759 {
2760 	u32 queue_len = atomic_read(&mrt->cache_resolve_queue_len);
2761 
2762 	if (nla_put_u32(skb, IPMRA_TABLE_ID, mrt->id) ||
2763 	    nla_put_u32(skb, IPMRA_TABLE_CACHE_RES_QUEUE_LEN, queue_len) ||
2764 	    nla_put_s32(skb, IPMRA_TABLE_MROUTE_REG_VIF_NUM,
2765 			mrt->mroute_reg_vif_num) ||
2766 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_ASSERT,
2767 		       mrt->mroute_do_assert) ||
2768 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_PIM, mrt->mroute_do_pim) ||
2769 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_WRVIFWHOLE,
2770 		       mrt->mroute_do_wrvifwhole))
2771 		return false;
2772 
2773 	return true;
2774 }
2775 
2776 static bool ipmr_fill_vif(struct mr_table *mrt, u32 vifid, struct sk_buff *skb)
2777 {
2778 	struct nlattr *vif_nest;
2779 	struct vif_device *vif;
2780 
2781 	/* if the VIF doesn't exist just continue */
2782 	if (!VIF_EXISTS(mrt, vifid))
2783 		return true;
2784 
2785 	vif = &mrt->vif_table[vifid];
2786 	vif_nest = nla_nest_start_noflag(skb, IPMRA_VIF);
2787 	if (!vif_nest)
2788 		return false;
2789 	if (nla_put_u32(skb, IPMRA_VIFA_IFINDEX, vif->dev->ifindex) ||
2790 	    nla_put_u32(skb, IPMRA_VIFA_VIF_ID, vifid) ||
2791 	    nla_put_u16(skb, IPMRA_VIFA_FLAGS, vif->flags) ||
2792 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_IN, vif->bytes_in,
2793 			      IPMRA_VIFA_PAD) ||
2794 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_OUT, vif->bytes_out,
2795 			      IPMRA_VIFA_PAD) ||
2796 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_IN, vif->pkt_in,
2797 			      IPMRA_VIFA_PAD) ||
2798 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_OUT, vif->pkt_out,
2799 			      IPMRA_VIFA_PAD) ||
2800 	    nla_put_be32(skb, IPMRA_VIFA_LOCAL_ADDR, vif->local) ||
2801 	    nla_put_be32(skb, IPMRA_VIFA_REMOTE_ADDR, vif->remote)) {
2802 		nla_nest_cancel(skb, vif_nest);
2803 		return false;
2804 	}
2805 	nla_nest_end(skb, vif_nest);
2806 
2807 	return true;
2808 }
2809 
2810 static int ipmr_valid_dumplink(const struct nlmsghdr *nlh,
2811 			       struct netlink_ext_ack *extack)
2812 {
2813 	struct ifinfomsg *ifm;
2814 
2815 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) {
2816 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for ipmr link dump");
2817 		return -EINVAL;
2818 	}
2819 
2820 	if (nlmsg_attrlen(nlh, sizeof(*ifm))) {
2821 		NL_SET_ERR_MSG(extack, "Invalid data after header in ipmr link dump");
2822 		return -EINVAL;
2823 	}
2824 
2825 	ifm = nlmsg_data(nlh);
2826 	if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags ||
2827 	    ifm->ifi_change || ifm->ifi_index) {
2828 		NL_SET_ERR_MSG(extack, "Invalid values in header for ipmr link dump request");
2829 		return -EINVAL;
2830 	}
2831 
2832 	return 0;
2833 }
2834 
2835 static int ipmr_rtm_dumplink(struct sk_buff *skb, struct netlink_callback *cb)
2836 {
2837 	struct net *net = sock_net(skb->sk);
2838 	struct nlmsghdr *nlh = NULL;
2839 	unsigned int t = 0, s_t;
2840 	unsigned int e = 0, s_e;
2841 	struct mr_table *mrt;
2842 
2843 	if (cb->strict_check) {
2844 		int err = ipmr_valid_dumplink(cb->nlh, cb->extack);
2845 
2846 		if (err < 0)
2847 			return err;
2848 	}
2849 
2850 	s_t = cb->args[0];
2851 	s_e = cb->args[1];
2852 
2853 	ipmr_for_each_table(mrt, net) {
2854 		struct nlattr *vifs, *af;
2855 		struct ifinfomsg *hdr;
2856 		u32 i;
2857 
2858 		if (t < s_t)
2859 			goto skip_table;
2860 		nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
2861 				cb->nlh->nlmsg_seq, RTM_NEWLINK,
2862 				sizeof(*hdr), NLM_F_MULTI);
2863 		if (!nlh)
2864 			break;
2865 
2866 		hdr = nlmsg_data(nlh);
2867 		memset(hdr, 0, sizeof(*hdr));
2868 		hdr->ifi_family = RTNL_FAMILY_IPMR;
2869 
2870 		af = nla_nest_start_noflag(skb, IFLA_AF_SPEC);
2871 		if (!af) {
2872 			nlmsg_cancel(skb, nlh);
2873 			goto out;
2874 		}
2875 
2876 		if (!ipmr_fill_table(mrt, skb)) {
2877 			nlmsg_cancel(skb, nlh);
2878 			goto out;
2879 		}
2880 
2881 		vifs = nla_nest_start_noflag(skb, IPMRA_TABLE_VIFS);
2882 		if (!vifs) {
2883 			nla_nest_end(skb, af);
2884 			nlmsg_end(skb, nlh);
2885 			goto out;
2886 		}
2887 		for (i = 0; i < mrt->maxvif; i++) {
2888 			if (e < s_e)
2889 				goto skip_entry;
2890 			if (!ipmr_fill_vif(mrt, i, skb)) {
2891 				nla_nest_end(skb, vifs);
2892 				nla_nest_end(skb, af);
2893 				nlmsg_end(skb, nlh);
2894 				goto out;
2895 			}
2896 skip_entry:
2897 			e++;
2898 		}
2899 		s_e = 0;
2900 		e = 0;
2901 		nla_nest_end(skb, vifs);
2902 		nla_nest_end(skb, af);
2903 		nlmsg_end(skb, nlh);
2904 skip_table:
2905 		t++;
2906 	}
2907 
2908 out:
2909 	cb->args[1] = e;
2910 	cb->args[0] = t;
2911 
2912 	return skb->len;
2913 }
2914 
2915 #ifdef CONFIG_PROC_FS
2916 /* The /proc interfaces to multicast routing :
2917  * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2918  */
2919 
2920 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2921 	__acquires(mrt_lock)
2922 {
2923 	struct mr_vif_iter *iter = seq->private;
2924 	struct net *net = seq_file_net(seq);
2925 	struct mr_table *mrt;
2926 
2927 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2928 	if (!mrt)
2929 		return ERR_PTR(-ENOENT);
2930 
2931 	iter->mrt = mrt;
2932 
2933 	read_lock(&mrt_lock);
2934 	return mr_vif_seq_start(seq, pos);
2935 }
2936 
2937 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2938 	__releases(mrt_lock)
2939 {
2940 	read_unlock(&mrt_lock);
2941 }
2942 
2943 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2944 {
2945 	struct mr_vif_iter *iter = seq->private;
2946 	struct mr_table *mrt = iter->mrt;
2947 
2948 	if (v == SEQ_START_TOKEN) {
2949 		seq_puts(seq,
2950 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2951 	} else {
2952 		const struct vif_device *vif = v;
2953 		const char *name =  vif->dev ?
2954 				    vif->dev->name : "none";
2955 
2956 		seq_printf(seq,
2957 			   "%2td %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2958 			   vif - mrt->vif_table,
2959 			   name, vif->bytes_in, vif->pkt_in,
2960 			   vif->bytes_out, vif->pkt_out,
2961 			   vif->flags, vif->local, vif->remote);
2962 	}
2963 	return 0;
2964 }
2965 
2966 static const struct seq_operations ipmr_vif_seq_ops = {
2967 	.start = ipmr_vif_seq_start,
2968 	.next  = mr_vif_seq_next,
2969 	.stop  = ipmr_vif_seq_stop,
2970 	.show  = ipmr_vif_seq_show,
2971 };
2972 
2973 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2974 {
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 	return mr_mfc_seq_start(seq, pos, mrt, &mfc_unres_lock);
2983 }
2984 
2985 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2986 {
2987 	int n;
2988 
2989 	if (v == SEQ_START_TOKEN) {
2990 		seq_puts(seq,
2991 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2992 	} else {
2993 		const struct mfc_cache *mfc = v;
2994 		const struct mr_mfc_iter *it = seq->private;
2995 		const struct mr_table *mrt = it->mrt;
2996 
2997 		seq_printf(seq, "%08X %08X %-3hd",
2998 			   (__force u32) mfc->mfc_mcastgrp,
2999 			   (__force u32) mfc->mfc_origin,
3000 			   mfc->_c.mfc_parent);
3001 
3002 		if (it->cache != &mrt->mfc_unres_queue) {
3003 			seq_printf(seq, " %8lu %8lu %8lu",
3004 				   mfc->_c.mfc_un.res.pkt,
3005 				   mfc->_c.mfc_un.res.bytes,
3006 				   mfc->_c.mfc_un.res.wrong_if);
3007 			for (n = mfc->_c.mfc_un.res.minvif;
3008 			     n < mfc->_c.mfc_un.res.maxvif; n++) {
3009 				if (VIF_EXISTS(mrt, n) &&
3010 				    mfc->_c.mfc_un.res.ttls[n] < 255)
3011 					seq_printf(seq,
3012 					   " %2d:%-3d",
3013 					   n, mfc->_c.mfc_un.res.ttls[n]);
3014 			}
3015 		} else {
3016 			/* unresolved mfc_caches don't contain
3017 			 * pkt, bytes and wrong_if values
3018 			 */
3019 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
3020 		}
3021 		seq_putc(seq, '\n');
3022 	}
3023 	return 0;
3024 }
3025 
3026 static const struct seq_operations ipmr_mfc_seq_ops = {
3027 	.start = ipmr_mfc_seq_start,
3028 	.next  = mr_mfc_seq_next,
3029 	.stop  = mr_mfc_seq_stop,
3030 	.show  = ipmr_mfc_seq_show,
3031 };
3032 #endif
3033 
3034 #ifdef CONFIG_IP_PIMSM_V2
3035 static const struct net_protocol pim_protocol = {
3036 	.handler	=	pim_rcv,
3037 	.netns_ok	=	1,
3038 };
3039 #endif
3040 
3041 static unsigned int ipmr_seq_read(struct net *net)
3042 {
3043 	ASSERT_RTNL();
3044 
3045 	return net->ipv4.ipmr_seq + ipmr_rules_seq_read(net);
3046 }
3047 
3048 static int ipmr_dump(struct net *net, struct notifier_block *nb)
3049 {
3050 	return mr_dump(net, nb, RTNL_FAMILY_IPMR, ipmr_rules_dump,
3051 		       ipmr_mr_table_iter, &mrt_lock);
3052 }
3053 
3054 static const struct fib_notifier_ops ipmr_notifier_ops_template = {
3055 	.family		= RTNL_FAMILY_IPMR,
3056 	.fib_seq_read	= ipmr_seq_read,
3057 	.fib_dump	= ipmr_dump,
3058 	.owner		= THIS_MODULE,
3059 };
3060 
3061 static int __net_init ipmr_notifier_init(struct net *net)
3062 {
3063 	struct fib_notifier_ops *ops;
3064 
3065 	net->ipv4.ipmr_seq = 0;
3066 
3067 	ops = fib_notifier_ops_register(&ipmr_notifier_ops_template, net);
3068 	if (IS_ERR(ops))
3069 		return PTR_ERR(ops);
3070 	net->ipv4.ipmr_notifier_ops = ops;
3071 
3072 	return 0;
3073 }
3074 
3075 static void __net_exit ipmr_notifier_exit(struct net *net)
3076 {
3077 	fib_notifier_ops_unregister(net->ipv4.ipmr_notifier_ops);
3078 	net->ipv4.ipmr_notifier_ops = NULL;
3079 }
3080 
3081 /* Setup for IP multicast routing */
3082 static int __net_init ipmr_net_init(struct net *net)
3083 {
3084 	int err;
3085 
3086 	err = ipmr_notifier_init(net);
3087 	if (err)
3088 		goto ipmr_notifier_fail;
3089 
3090 	err = ipmr_rules_init(net);
3091 	if (err < 0)
3092 		goto ipmr_rules_fail;
3093 
3094 #ifdef CONFIG_PROC_FS
3095 	err = -ENOMEM;
3096 	if (!proc_create_net("ip_mr_vif", 0, net->proc_net, &ipmr_vif_seq_ops,
3097 			sizeof(struct mr_vif_iter)))
3098 		goto proc_vif_fail;
3099 	if (!proc_create_net("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_seq_ops,
3100 			sizeof(struct mr_mfc_iter)))
3101 		goto proc_cache_fail;
3102 #endif
3103 	return 0;
3104 
3105 #ifdef CONFIG_PROC_FS
3106 proc_cache_fail:
3107 	remove_proc_entry("ip_mr_vif", net->proc_net);
3108 proc_vif_fail:
3109 	ipmr_rules_exit(net);
3110 #endif
3111 ipmr_rules_fail:
3112 	ipmr_notifier_exit(net);
3113 ipmr_notifier_fail:
3114 	return err;
3115 }
3116 
3117 static void __net_exit ipmr_net_exit(struct net *net)
3118 {
3119 #ifdef CONFIG_PROC_FS
3120 	remove_proc_entry("ip_mr_cache", net->proc_net);
3121 	remove_proc_entry("ip_mr_vif", net->proc_net);
3122 #endif
3123 	ipmr_notifier_exit(net);
3124 	ipmr_rules_exit(net);
3125 }
3126 
3127 static struct pernet_operations ipmr_net_ops = {
3128 	.init = ipmr_net_init,
3129 	.exit = ipmr_net_exit,
3130 };
3131 
3132 int __init ip_mr_init(void)
3133 {
3134 	int err;
3135 
3136 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
3137 				       sizeof(struct mfc_cache),
3138 				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
3139 				       NULL);
3140 
3141 	err = register_pernet_subsys(&ipmr_net_ops);
3142 	if (err)
3143 		goto reg_pernet_fail;
3144 
3145 	err = register_netdevice_notifier(&ip_mr_notifier);
3146 	if (err)
3147 		goto reg_notif_fail;
3148 #ifdef CONFIG_IP_PIMSM_V2
3149 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
3150 		pr_err("%s: can't add PIM protocol\n", __func__);
3151 		err = -EAGAIN;
3152 		goto add_proto_fail;
3153 	}
3154 #endif
3155 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
3156 		      ipmr_rtm_getroute, ipmr_rtm_dumproute, 0);
3157 	rtnl_register(RTNL_FAMILY_IPMR, RTM_NEWROUTE,
3158 		      ipmr_rtm_route, NULL, 0);
3159 	rtnl_register(RTNL_FAMILY_IPMR, RTM_DELROUTE,
3160 		      ipmr_rtm_route, NULL, 0);
3161 
3162 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETLINK,
3163 		      NULL, ipmr_rtm_dumplink, 0);
3164 	return 0;
3165 
3166 #ifdef CONFIG_IP_PIMSM_V2
3167 add_proto_fail:
3168 	unregister_netdevice_notifier(&ip_mr_notifier);
3169 #endif
3170 reg_notif_fail:
3171 	unregister_pernet_subsys(&ipmr_net_ops);
3172 reg_pernet_fail:
3173 	kmem_cache_destroy(mrt_cachep);
3174 	return err;
3175 }
3176