xref: /linux/net/ipv4/ipmr.c (revision fba2689ee77e63b05e203b3f26079ef915e55660)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	IP multicast routing support for mrouted 3.6/3.8
4  *
5  *		(c) 1995 Alan Cox, <alan@lxorguk.ukuu.org.uk>
6  *	  Linux Consultancy and Custom Driver Development
7  *
8  *	Fixes:
9  *	Michael Chastain	:	Incorrect size of copying.
10  *	Alan Cox		:	Added the cache manager code
11  *	Alan Cox		:	Fixed the clone/copy bug and device race.
12  *	Mike McLagan		:	Routing by source
13  *	Malcolm Beattie		:	Buffer handling fixes.
14  *	Alexey Kuznetsov	:	Double buffer free and other fixes.
15  *	SVR Anand		:	Fixed several multicast bugs and problems.
16  *	Alexey Kuznetsov	:	Status, optimisations and more.
17  *	Brad Parker		:	Better behaviour on mrouted upcall
18  *					overflow.
19  *      Carlos Picoto           :       PIMv1 Support
20  *	Pavlin Ivanov Radoslavov:	PIMv2 Registers must checksum only PIM header
21  *					Relax this requirement to work with older peers.
22  */
23 
24 #include <linux/uaccess.h>
25 #include <linux/types.h>
26 #include <linux/cache.h>
27 #include <linux/capability.h>
28 #include <linux/errno.h>
29 #include <linux/mm.h>
30 #include <linux/kernel.h>
31 #include <linux/fcntl.h>
32 #include <linux/stat.h>
33 #include <linux/socket.h>
34 #include <linux/in.h>
35 #include <linux/inet.h>
36 #include <linux/netdevice.h>
37 #include <linux/inetdevice.h>
38 #include <linux/igmp.h>
39 #include <linux/proc_fs.h>
40 #include <linux/seq_file.h>
41 #include <linux/mroute.h>
42 #include <linux/init.h>
43 #include <linux/if_ether.h>
44 #include <linux/slab.h>
45 #include <net/net_namespace.h>
46 #include <net/ip.h>
47 #include <net/protocol.h>
48 #include <linux/skbuff.h>
49 #include <net/route.h>
50 #include <net/icmp.h>
51 #include <net/udp.h>
52 #include <net/raw.h>
53 #include <linux/notifier.h>
54 #include <linux/if_arp.h>
55 #include <linux/netfilter_ipv4.h>
56 #include <linux/compat.h>
57 #include <linux/export.h>
58 #include <linux/rhashtable.h>
59 #include <net/ip_tunnels.h>
60 #include <net/checksum.h>
61 #include <net/netlink.h>
62 #include <net/fib_rules.h>
63 #include <linux/netconf.h>
64 #include <net/rtnh.h>
65 
66 #include <linux/nospec.h>
67 
68 struct ipmr_rule {
69 	struct fib_rule		common;
70 };
71 
72 struct ipmr_result {
73 	struct mr_table		*mrt;
74 };
75 
76 /* Big lock, protecting vif table, mrt cache and mroute socket state.
77  * Note that the changes are semaphored via rtnl_lock.
78  */
79 
80 static DEFINE_RWLOCK(mrt_lock);
81 
82 /* Multicast router control variables */
83 
84 /* Special spinlock for queue of unresolved entries */
85 static DEFINE_SPINLOCK(mfc_unres_lock);
86 
87 /* We return to original Alan's scheme. Hash table of resolved
88  * entries is changed only in process context and protected
89  * with weak lock mrt_lock. Queue of unresolved entries is protected
90  * with strong spinlock mfc_unres_lock.
91  *
92  * In this case data path is free of exclusive locks at all.
93  */
94 
95 static struct kmem_cache *mrt_cachep __ro_after_init;
96 
97 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
98 static void ipmr_free_table(struct mr_table *mrt);
99 
100 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
101 			  struct net_device *dev, struct sk_buff *skb,
102 			  struct mfc_cache *cache, int local);
103 static int ipmr_cache_report(struct mr_table *mrt,
104 			     struct sk_buff *pkt, vifi_t vifi, int assert);
105 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
106 				 int cmd);
107 static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
108 static void mroute_clean_tables(struct mr_table *mrt, int flags);
109 static void ipmr_expire_process(struct timer_list *t);
110 
111 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
112 #define ipmr_for_each_table(mrt, net)					\
113 	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list,	\
114 				lockdep_rtnl_is_held() ||		\
115 				list_empty(&net->ipv4.mr_tables))
116 
117 static struct mr_table *ipmr_mr_table_iter(struct net *net,
118 					   struct mr_table *mrt)
119 {
120 	struct mr_table *ret;
121 
122 	if (!mrt)
123 		ret = list_entry_rcu(net->ipv4.mr_tables.next,
124 				     struct mr_table, list);
125 	else
126 		ret = list_entry_rcu(mrt->list.next,
127 				     struct mr_table, list);
128 
129 	if (&ret->list == &net->ipv4.mr_tables)
130 		return NULL;
131 	return ret;
132 }
133 
134 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
135 {
136 	struct mr_table *mrt;
137 
138 	ipmr_for_each_table(mrt, net) {
139 		if (mrt->id == id)
140 			return mrt;
141 	}
142 	return NULL;
143 }
144 
145 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
146 			   struct mr_table **mrt)
147 {
148 	int err;
149 	struct ipmr_result res;
150 	struct fib_lookup_arg arg = {
151 		.result = &res,
152 		.flags = FIB_LOOKUP_NOREF,
153 	};
154 
155 	/* update flow if oif or iif point to device enslaved to l3mdev */
156 	l3mdev_update_flow(net, flowi4_to_flowi(flp4));
157 
158 	err = fib_rules_lookup(net->ipv4.mr_rules_ops,
159 			       flowi4_to_flowi(flp4), 0, &arg);
160 	if (err < 0)
161 		return err;
162 	*mrt = res.mrt;
163 	return 0;
164 }
165 
166 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
167 			    int flags, struct fib_lookup_arg *arg)
168 {
169 	struct ipmr_result *res = arg->result;
170 	struct mr_table *mrt;
171 
172 	switch (rule->action) {
173 	case FR_ACT_TO_TBL:
174 		break;
175 	case FR_ACT_UNREACHABLE:
176 		return -ENETUNREACH;
177 	case FR_ACT_PROHIBIT:
178 		return -EACCES;
179 	case FR_ACT_BLACKHOLE:
180 	default:
181 		return -EINVAL;
182 	}
183 
184 	arg->table = fib_rule_get_table(rule, arg);
185 
186 	mrt = ipmr_get_table(rule->fr_net, arg->table);
187 	if (!mrt)
188 		return -EAGAIN;
189 	res->mrt = mrt;
190 	return 0;
191 }
192 
193 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
194 {
195 	return 1;
196 }
197 
198 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
199 			       struct fib_rule_hdr *frh, struct nlattr **tb,
200 			       struct netlink_ext_ack *extack)
201 {
202 	return 0;
203 }
204 
205 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
206 			     struct nlattr **tb)
207 {
208 	return 1;
209 }
210 
211 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
212 			  struct fib_rule_hdr *frh)
213 {
214 	frh->dst_len = 0;
215 	frh->src_len = 0;
216 	frh->tos     = 0;
217 	return 0;
218 }
219 
220 static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
221 	.family		= RTNL_FAMILY_IPMR,
222 	.rule_size	= sizeof(struct ipmr_rule),
223 	.addr_size	= sizeof(u32),
224 	.action		= ipmr_rule_action,
225 	.match		= ipmr_rule_match,
226 	.configure	= ipmr_rule_configure,
227 	.compare	= ipmr_rule_compare,
228 	.fill		= ipmr_rule_fill,
229 	.nlgroup	= RTNLGRP_IPV4_RULE,
230 	.owner		= THIS_MODULE,
231 };
232 
233 static int __net_init ipmr_rules_init(struct net *net)
234 {
235 	struct fib_rules_ops *ops;
236 	struct mr_table *mrt;
237 	int err;
238 
239 	ops = fib_rules_register(&ipmr_rules_ops_template, net);
240 	if (IS_ERR(ops))
241 		return PTR_ERR(ops);
242 
243 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
244 
245 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
246 	if (IS_ERR(mrt)) {
247 		err = PTR_ERR(mrt);
248 		goto err1;
249 	}
250 
251 	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
252 	if (err < 0)
253 		goto err2;
254 
255 	net->ipv4.mr_rules_ops = ops;
256 	return 0;
257 
258 err2:
259 	rtnl_lock();
260 	ipmr_free_table(mrt);
261 	rtnl_unlock();
262 err1:
263 	fib_rules_unregister(ops);
264 	return err;
265 }
266 
267 static void __net_exit ipmr_rules_exit(struct net *net)
268 {
269 	struct mr_table *mrt, *next;
270 
271 	ASSERT_RTNL();
272 	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
273 		list_del(&mrt->list);
274 		ipmr_free_table(mrt);
275 	}
276 	fib_rules_unregister(net->ipv4.mr_rules_ops);
277 }
278 
279 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
280 			   struct netlink_ext_ack *extack)
281 {
282 	return fib_rules_dump(net, nb, RTNL_FAMILY_IPMR, extack);
283 }
284 
285 static unsigned int ipmr_rules_seq_read(struct net *net)
286 {
287 	return fib_rules_seq_read(net, RTNL_FAMILY_IPMR);
288 }
289 
290 bool ipmr_rule_default(const struct fib_rule *rule)
291 {
292 	return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
293 }
294 EXPORT_SYMBOL(ipmr_rule_default);
295 #else
296 #define ipmr_for_each_table(mrt, net) \
297 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
298 
299 static struct mr_table *ipmr_mr_table_iter(struct net *net,
300 					   struct mr_table *mrt)
301 {
302 	if (!mrt)
303 		return net->ipv4.mrt;
304 	return NULL;
305 }
306 
307 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
308 {
309 	return net->ipv4.mrt;
310 }
311 
312 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
313 			   struct mr_table **mrt)
314 {
315 	*mrt = net->ipv4.mrt;
316 	return 0;
317 }
318 
319 static int __net_init ipmr_rules_init(struct net *net)
320 {
321 	struct mr_table *mrt;
322 
323 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
324 	if (IS_ERR(mrt))
325 		return PTR_ERR(mrt);
326 	net->ipv4.mrt = mrt;
327 	return 0;
328 }
329 
330 static void __net_exit ipmr_rules_exit(struct net *net)
331 {
332 	ASSERT_RTNL();
333 	ipmr_free_table(net->ipv4.mrt);
334 	net->ipv4.mrt = NULL;
335 }
336 
337 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
338 			   struct netlink_ext_ack *extack)
339 {
340 	return 0;
341 }
342 
343 static unsigned int ipmr_rules_seq_read(struct net *net)
344 {
345 	return 0;
346 }
347 
348 bool ipmr_rule_default(const struct fib_rule *rule)
349 {
350 	return true;
351 }
352 EXPORT_SYMBOL(ipmr_rule_default);
353 #endif
354 
355 static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
356 				const void *ptr)
357 {
358 	const struct mfc_cache_cmp_arg *cmparg = arg->key;
359 	struct mfc_cache *c = (struct mfc_cache *)ptr;
360 
361 	return cmparg->mfc_mcastgrp != c->mfc_mcastgrp ||
362 	       cmparg->mfc_origin != c->mfc_origin;
363 }
364 
365 static const struct rhashtable_params ipmr_rht_params = {
366 	.head_offset = offsetof(struct mr_mfc, mnode),
367 	.key_offset = offsetof(struct mfc_cache, cmparg),
368 	.key_len = sizeof(struct mfc_cache_cmp_arg),
369 	.nelem_hint = 3,
370 	.obj_cmpfn = ipmr_hash_cmp,
371 	.automatic_shrinking = true,
372 };
373 
374 static void ipmr_new_table_set(struct mr_table *mrt,
375 			       struct net *net)
376 {
377 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
378 	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
379 #endif
380 }
381 
382 static struct mfc_cache_cmp_arg ipmr_mr_table_ops_cmparg_any = {
383 	.mfc_mcastgrp = htonl(INADDR_ANY),
384 	.mfc_origin = htonl(INADDR_ANY),
385 };
386 
387 static struct mr_table_ops ipmr_mr_table_ops = {
388 	.rht_params = &ipmr_rht_params,
389 	.cmparg_any = &ipmr_mr_table_ops_cmparg_any,
390 };
391 
392 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
393 {
394 	struct mr_table *mrt;
395 
396 	/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
397 	if (id != RT_TABLE_DEFAULT && id >= 1000000000)
398 		return ERR_PTR(-EINVAL);
399 
400 	mrt = ipmr_get_table(net, id);
401 	if (mrt)
402 		return mrt;
403 
404 	return mr_table_alloc(net, id, &ipmr_mr_table_ops,
405 			      ipmr_expire_process, ipmr_new_table_set);
406 }
407 
408 static void ipmr_free_table(struct mr_table *mrt)
409 {
410 	del_timer_sync(&mrt->ipmr_expire_timer);
411 	mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC |
412 				 MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC);
413 	rhltable_destroy(&mrt->mfc_hash);
414 	kfree(mrt);
415 }
416 
417 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
418 
419 /* Initialize ipmr pimreg/tunnel in_device */
420 static bool ipmr_init_vif_indev(const struct net_device *dev)
421 {
422 	struct in_device *in_dev;
423 
424 	ASSERT_RTNL();
425 
426 	in_dev = __in_dev_get_rtnl(dev);
427 	if (!in_dev)
428 		return false;
429 	ipv4_devconf_setall(in_dev);
430 	neigh_parms_data_state_setall(in_dev->arp_parms);
431 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
432 
433 	return true;
434 }
435 
436 static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
437 {
438 	struct net_device *tunnel_dev, *new_dev;
439 	struct ip_tunnel_parm p = { };
440 	int err;
441 
442 	tunnel_dev = __dev_get_by_name(net, "tunl0");
443 	if (!tunnel_dev)
444 		goto out;
445 
446 	p.iph.daddr = v->vifc_rmt_addr.s_addr;
447 	p.iph.saddr = v->vifc_lcl_addr.s_addr;
448 	p.iph.version = 4;
449 	p.iph.ihl = 5;
450 	p.iph.protocol = IPPROTO_IPIP;
451 	sprintf(p.name, "dvmrp%d", v->vifc_vifi);
452 
453 	if (!tunnel_dev->netdev_ops->ndo_tunnel_ctl)
454 		goto out;
455 	err = tunnel_dev->netdev_ops->ndo_tunnel_ctl(tunnel_dev, &p,
456 			SIOCADDTUNNEL);
457 	if (err)
458 		goto out;
459 
460 	new_dev = __dev_get_by_name(net, p.name);
461 	if (!new_dev)
462 		goto out;
463 
464 	new_dev->flags |= IFF_MULTICAST;
465 	if (!ipmr_init_vif_indev(new_dev))
466 		goto out_unregister;
467 	if (dev_open(new_dev, NULL))
468 		goto out_unregister;
469 	dev_hold(new_dev);
470 	err = dev_set_allmulti(new_dev, 1);
471 	if (err) {
472 		dev_close(new_dev);
473 		tunnel_dev->netdev_ops->ndo_tunnel_ctl(tunnel_dev, &p,
474 				SIOCDELTUNNEL);
475 		dev_put(new_dev);
476 		new_dev = ERR_PTR(err);
477 	}
478 	return new_dev;
479 
480 out_unregister:
481 	unregister_netdevice(new_dev);
482 out:
483 	return ERR_PTR(-ENOBUFS);
484 }
485 
486 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
487 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
488 {
489 	struct net *net = dev_net(dev);
490 	struct mr_table *mrt;
491 	struct flowi4 fl4 = {
492 		.flowi4_oif	= dev->ifindex,
493 		.flowi4_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
494 		.flowi4_mark	= skb->mark,
495 	};
496 	int err;
497 
498 	err = ipmr_fib_lookup(net, &fl4, &mrt);
499 	if (err < 0) {
500 		kfree_skb(skb);
501 		return err;
502 	}
503 
504 	read_lock(&mrt_lock);
505 	dev->stats.tx_bytes += skb->len;
506 	dev->stats.tx_packets++;
507 	ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
508 	read_unlock(&mrt_lock);
509 	kfree_skb(skb);
510 	return NETDEV_TX_OK;
511 }
512 
513 static int reg_vif_get_iflink(const struct net_device *dev)
514 {
515 	return 0;
516 }
517 
518 static const struct net_device_ops reg_vif_netdev_ops = {
519 	.ndo_start_xmit	= reg_vif_xmit,
520 	.ndo_get_iflink = reg_vif_get_iflink,
521 };
522 
523 static void reg_vif_setup(struct net_device *dev)
524 {
525 	dev->type		= ARPHRD_PIMREG;
526 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
527 	dev->flags		= IFF_NOARP;
528 	dev->netdev_ops		= &reg_vif_netdev_ops;
529 	dev->needs_free_netdev	= true;
530 	dev->features		|= NETIF_F_NETNS_LOCAL;
531 }
532 
533 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
534 {
535 	struct net_device *dev;
536 	char name[IFNAMSIZ];
537 
538 	if (mrt->id == RT_TABLE_DEFAULT)
539 		sprintf(name, "pimreg");
540 	else
541 		sprintf(name, "pimreg%u", mrt->id);
542 
543 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
544 
545 	if (!dev)
546 		return NULL;
547 
548 	dev_net_set(dev, net);
549 
550 	if (register_netdevice(dev)) {
551 		free_netdev(dev);
552 		return NULL;
553 	}
554 
555 	if (!ipmr_init_vif_indev(dev))
556 		goto failure;
557 	if (dev_open(dev, NULL))
558 		goto failure;
559 
560 	dev_hold(dev);
561 
562 	return dev;
563 
564 failure:
565 	unregister_netdevice(dev);
566 	return NULL;
567 }
568 
569 /* called with rcu_read_lock() */
570 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
571 		     unsigned int pimlen)
572 {
573 	struct net_device *reg_dev = NULL;
574 	struct iphdr *encap;
575 
576 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
577 	/* Check that:
578 	 * a. packet is really sent to a multicast group
579 	 * b. packet is not a NULL-REGISTER
580 	 * c. packet is not truncated
581 	 */
582 	if (!ipv4_is_multicast(encap->daddr) ||
583 	    encap->tot_len == 0 ||
584 	    ntohs(encap->tot_len) + pimlen > skb->len)
585 		return 1;
586 
587 	read_lock(&mrt_lock);
588 	if (mrt->mroute_reg_vif_num >= 0)
589 		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
590 	read_unlock(&mrt_lock);
591 
592 	if (!reg_dev)
593 		return 1;
594 
595 	skb->mac_header = skb->network_header;
596 	skb_pull(skb, (u8 *)encap - skb->data);
597 	skb_reset_network_header(skb);
598 	skb->protocol = htons(ETH_P_IP);
599 	skb->ip_summed = CHECKSUM_NONE;
600 
601 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
602 
603 	netif_rx(skb);
604 
605 	return NET_RX_SUCCESS;
606 }
607 #else
608 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
609 {
610 	return NULL;
611 }
612 #endif
613 
614 static int call_ipmr_vif_entry_notifiers(struct net *net,
615 					 enum fib_event_type event_type,
616 					 struct vif_device *vif,
617 					 vifi_t vif_index, u32 tb_id)
618 {
619 	return mr_call_vif_notifiers(net, RTNL_FAMILY_IPMR, event_type,
620 				     vif, vif_index, tb_id,
621 				     &net->ipv4.ipmr_seq);
622 }
623 
624 static int call_ipmr_mfc_entry_notifiers(struct net *net,
625 					 enum fib_event_type event_type,
626 					 struct mfc_cache *mfc, u32 tb_id)
627 {
628 	return mr_call_mfc_notifiers(net, RTNL_FAMILY_IPMR, event_type,
629 				     &mfc->_c, tb_id, &net->ipv4.ipmr_seq);
630 }
631 
632 /**
633  *	vif_delete - Delete a VIF entry
634  *	@mrt: Table to delete from
635  *	@vifi: VIF identifier to delete
636  *	@notify: Set to 1, if the caller is a notifier_call
637  *	@head: if unregistering the VIF, place it on this queue
638  */
639 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
640 		      struct list_head *head)
641 {
642 	struct net *net = read_pnet(&mrt->net);
643 	struct vif_device *v;
644 	struct net_device *dev;
645 	struct in_device *in_dev;
646 
647 	if (vifi < 0 || vifi >= mrt->maxvif)
648 		return -EADDRNOTAVAIL;
649 
650 	v = &mrt->vif_table[vifi];
651 
652 	if (VIF_EXISTS(mrt, vifi))
653 		call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_DEL, v, vifi,
654 					      mrt->id);
655 
656 	write_lock_bh(&mrt_lock);
657 	dev = v->dev;
658 	v->dev = NULL;
659 
660 	if (!dev) {
661 		write_unlock_bh(&mrt_lock);
662 		return -EADDRNOTAVAIL;
663 	}
664 
665 	if (vifi == mrt->mroute_reg_vif_num)
666 		mrt->mroute_reg_vif_num = -1;
667 
668 	if (vifi + 1 == mrt->maxvif) {
669 		int tmp;
670 
671 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
672 			if (VIF_EXISTS(mrt, tmp))
673 				break;
674 		}
675 		mrt->maxvif = tmp+1;
676 	}
677 
678 	write_unlock_bh(&mrt_lock);
679 
680 	dev_set_allmulti(dev, -1);
681 
682 	in_dev = __in_dev_get_rtnl(dev);
683 	if (in_dev) {
684 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
685 		inet_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
686 					    NETCONFA_MC_FORWARDING,
687 					    dev->ifindex, &in_dev->cnf);
688 		ip_rt_multicast_event(in_dev);
689 	}
690 
691 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
692 		unregister_netdevice_queue(dev, head);
693 
694 	dev_put_track(dev, &v->dev_tracker);
695 	return 0;
696 }
697 
698 static void ipmr_cache_free_rcu(struct rcu_head *head)
699 {
700 	struct mr_mfc *c = container_of(head, struct mr_mfc, rcu);
701 
702 	kmem_cache_free(mrt_cachep, (struct mfc_cache *)c);
703 }
704 
705 static void ipmr_cache_free(struct mfc_cache *c)
706 {
707 	call_rcu(&c->_c.rcu, ipmr_cache_free_rcu);
708 }
709 
710 /* Destroy an unresolved cache entry, killing queued skbs
711  * and reporting error to netlink readers.
712  */
713 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
714 {
715 	struct net *net = read_pnet(&mrt->net);
716 	struct sk_buff *skb;
717 	struct nlmsgerr *e;
718 
719 	atomic_dec(&mrt->cache_resolve_queue_len);
720 
721 	while ((skb = skb_dequeue(&c->_c.mfc_un.unres.unresolved))) {
722 		if (ip_hdr(skb)->version == 0) {
723 			struct nlmsghdr *nlh = skb_pull(skb,
724 							sizeof(struct iphdr));
725 			nlh->nlmsg_type = NLMSG_ERROR;
726 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
727 			skb_trim(skb, nlh->nlmsg_len);
728 			e = nlmsg_data(nlh);
729 			e->error = -ETIMEDOUT;
730 			memset(&e->msg, 0, sizeof(e->msg));
731 
732 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
733 		} else {
734 			kfree_skb(skb);
735 		}
736 	}
737 
738 	ipmr_cache_free(c);
739 }
740 
741 /* Timer process for the unresolved queue. */
742 static void ipmr_expire_process(struct timer_list *t)
743 {
744 	struct mr_table *mrt = from_timer(mrt, t, ipmr_expire_timer);
745 	struct mr_mfc *c, *next;
746 	unsigned long expires;
747 	unsigned long now;
748 
749 	if (!spin_trylock(&mfc_unres_lock)) {
750 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
751 		return;
752 	}
753 
754 	if (list_empty(&mrt->mfc_unres_queue))
755 		goto out;
756 
757 	now = jiffies;
758 	expires = 10*HZ;
759 
760 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
761 		if (time_after(c->mfc_un.unres.expires, now)) {
762 			unsigned long interval = c->mfc_un.unres.expires - now;
763 			if (interval < expires)
764 				expires = interval;
765 			continue;
766 		}
767 
768 		list_del(&c->list);
769 		mroute_netlink_event(mrt, (struct mfc_cache *)c, RTM_DELROUTE);
770 		ipmr_destroy_unres(mrt, (struct mfc_cache *)c);
771 	}
772 
773 	if (!list_empty(&mrt->mfc_unres_queue))
774 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
775 
776 out:
777 	spin_unlock(&mfc_unres_lock);
778 }
779 
780 /* Fill oifs list. It is called under write locked mrt_lock. */
781 static void ipmr_update_thresholds(struct mr_table *mrt, struct mr_mfc *cache,
782 				   unsigned char *ttls)
783 {
784 	int vifi;
785 
786 	cache->mfc_un.res.minvif = MAXVIFS;
787 	cache->mfc_un.res.maxvif = 0;
788 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
789 
790 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
791 		if (VIF_EXISTS(mrt, vifi) &&
792 		    ttls[vifi] && ttls[vifi] < 255) {
793 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
794 			if (cache->mfc_un.res.minvif > vifi)
795 				cache->mfc_un.res.minvif = vifi;
796 			if (cache->mfc_un.res.maxvif <= vifi)
797 				cache->mfc_un.res.maxvif = vifi + 1;
798 		}
799 	}
800 	cache->mfc_un.res.lastuse = jiffies;
801 }
802 
803 static int vif_add(struct net *net, struct mr_table *mrt,
804 		   struct vifctl *vifc, int mrtsock)
805 {
806 	struct netdev_phys_item_id ppid = { };
807 	int vifi = vifc->vifc_vifi;
808 	struct vif_device *v = &mrt->vif_table[vifi];
809 	struct net_device *dev;
810 	struct in_device *in_dev;
811 	int err;
812 
813 	/* Is vif busy ? */
814 	if (VIF_EXISTS(mrt, vifi))
815 		return -EADDRINUSE;
816 
817 	switch (vifc->vifc_flags) {
818 	case VIFF_REGISTER:
819 		if (!ipmr_pimsm_enabled())
820 			return -EINVAL;
821 		/* Special Purpose VIF in PIM
822 		 * All the packets will be sent to the daemon
823 		 */
824 		if (mrt->mroute_reg_vif_num >= 0)
825 			return -EADDRINUSE;
826 		dev = ipmr_reg_vif(net, mrt);
827 		if (!dev)
828 			return -ENOBUFS;
829 		err = dev_set_allmulti(dev, 1);
830 		if (err) {
831 			unregister_netdevice(dev);
832 			dev_put(dev);
833 			return err;
834 		}
835 		break;
836 	case VIFF_TUNNEL:
837 		dev = ipmr_new_tunnel(net, vifc);
838 		if (IS_ERR(dev))
839 			return PTR_ERR(dev);
840 		break;
841 	case VIFF_USE_IFINDEX:
842 	case 0:
843 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
844 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
845 			if (dev && !__in_dev_get_rtnl(dev)) {
846 				dev_put(dev);
847 				return -EADDRNOTAVAIL;
848 			}
849 		} else {
850 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
851 		}
852 		if (!dev)
853 			return -EADDRNOTAVAIL;
854 		err = dev_set_allmulti(dev, 1);
855 		if (err) {
856 			dev_put(dev);
857 			return err;
858 		}
859 		break;
860 	default:
861 		return -EINVAL;
862 	}
863 
864 	in_dev = __in_dev_get_rtnl(dev);
865 	if (!in_dev) {
866 		dev_put(dev);
867 		return -EADDRNOTAVAIL;
868 	}
869 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
870 	inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING,
871 				    dev->ifindex, &in_dev->cnf);
872 	ip_rt_multicast_event(in_dev);
873 
874 	/* Fill in the VIF structures */
875 	vif_device_init(v, dev, vifc->vifc_rate_limit,
876 			vifc->vifc_threshold,
877 			vifc->vifc_flags | (!mrtsock ? VIFF_STATIC : 0),
878 			(VIFF_TUNNEL | VIFF_REGISTER));
879 
880 	err = dev_get_port_parent_id(dev, &ppid, true);
881 	if (err == 0) {
882 		memcpy(v->dev_parent_id.id, ppid.id, ppid.id_len);
883 		v->dev_parent_id.id_len = ppid.id_len;
884 	} else {
885 		v->dev_parent_id.id_len = 0;
886 	}
887 
888 	v->local = vifc->vifc_lcl_addr.s_addr;
889 	v->remote = vifc->vifc_rmt_addr.s_addr;
890 
891 	/* And finish update writing critical data */
892 	write_lock_bh(&mrt_lock);
893 	v->dev = dev;
894 	netdev_tracker_alloc(dev, &v->dev_tracker, GFP_ATOMIC);
895 	if (v->flags & VIFF_REGISTER)
896 		mrt->mroute_reg_vif_num = vifi;
897 	if (vifi+1 > mrt->maxvif)
898 		mrt->maxvif = vifi+1;
899 	write_unlock_bh(&mrt_lock);
900 	call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD, v, vifi, mrt->id);
901 	return 0;
902 }
903 
904 /* called with rcu_read_lock() */
905 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
906 					 __be32 origin,
907 					 __be32 mcastgrp)
908 {
909 	struct mfc_cache_cmp_arg arg = {
910 			.mfc_mcastgrp = mcastgrp,
911 			.mfc_origin = origin
912 	};
913 
914 	return mr_mfc_find(mrt, &arg);
915 }
916 
917 /* Look for a (*,G) entry */
918 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
919 					     __be32 mcastgrp, int vifi)
920 {
921 	struct mfc_cache_cmp_arg arg = {
922 			.mfc_mcastgrp = mcastgrp,
923 			.mfc_origin = htonl(INADDR_ANY)
924 	};
925 
926 	if (mcastgrp == htonl(INADDR_ANY))
927 		return mr_mfc_find_any_parent(mrt, vifi);
928 	return mr_mfc_find_any(mrt, vifi, &arg);
929 }
930 
931 /* Look for a (S,G,iif) entry if parent != -1 */
932 static struct mfc_cache *ipmr_cache_find_parent(struct mr_table *mrt,
933 						__be32 origin, __be32 mcastgrp,
934 						int parent)
935 {
936 	struct mfc_cache_cmp_arg arg = {
937 			.mfc_mcastgrp = mcastgrp,
938 			.mfc_origin = origin,
939 	};
940 
941 	return mr_mfc_find_parent(mrt, &arg, parent);
942 }
943 
944 /* Allocate a multicast cache entry */
945 static struct mfc_cache *ipmr_cache_alloc(void)
946 {
947 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
948 
949 	if (c) {
950 		c->_c.mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
951 		c->_c.mfc_un.res.minvif = MAXVIFS;
952 		c->_c.free = ipmr_cache_free_rcu;
953 		refcount_set(&c->_c.mfc_un.res.refcount, 1);
954 	}
955 	return c;
956 }
957 
958 static struct mfc_cache *ipmr_cache_alloc_unres(void)
959 {
960 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
961 
962 	if (c) {
963 		skb_queue_head_init(&c->_c.mfc_un.unres.unresolved);
964 		c->_c.mfc_un.unres.expires = jiffies + 10 * HZ;
965 	}
966 	return c;
967 }
968 
969 /* A cache entry has gone into a resolved state from queued */
970 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
971 			       struct mfc_cache *uc, struct mfc_cache *c)
972 {
973 	struct sk_buff *skb;
974 	struct nlmsgerr *e;
975 
976 	/* Play the pending entries through our router */
977 	while ((skb = __skb_dequeue(&uc->_c.mfc_un.unres.unresolved))) {
978 		if (ip_hdr(skb)->version == 0) {
979 			struct nlmsghdr *nlh = skb_pull(skb,
980 							sizeof(struct iphdr));
981 
982 			if (mr_fill_mroute(mrt, skb, &c->_c,
983 					   nlmsg_data(nlh)) > 0) {
984 				nlh->nlmsg_len = skb_tail_pointer(skb) -
985 						 (u8 *)nlh;
986 			} else {
987 				nlh->nlmsg_type = NLMSG_ERROR;
988 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
989 				skb_trim(skb, nlh->nlmsg_len);
990 				e = nlmsg_data(nlh);
991 				e->error = -EMSGSIZE;
992 				memset(&e->msg, 0, sizeof(e->msg));
993 			}
994 
995 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
996 		} else {
997 			ip_mr_forward(net, mrt, skb->dev, skb, c, 0);
998 		}
999 	}
1000 }
1001 
1002 /* Bounce a cache query up to mrouted and netlink.
1003  *
1004  * Called under mrt_lock.
1005  */
1006 static int ipmr_cache_report(struct mr_table *mrt,
1007 			     struct sk_buff *pkt, vifi_t vifi, int assert)
1008 {
1009 	const int ihl = ip_hdrlen(pkt);
1010 	struct sock *mroute_sk;
1011 	struct igmphdr *igmp;
1012 	struct igmpmsg *msg;
1013 	struct sk_buff *skb;
1014 	int ret;
1015 
1016 	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE)
1017 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
1018 	else
1019 		skb = alloc_skb(128, GFP_ATOMIC);
1020 
1021 	if (!skb)
1022 		return -ENOBUFS;
1023 
1024 	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE) {
1025 		/* Ugly, but we have no choice with this interface.
1026 		 * Duplicate old header, fix ihl, length etc.
1027 		 * And all this only to mangle msg->im_msgtype and
1028 		 * to set msg->im_mbz to "mbz" :-)
1029 		 */
1030 		skb_push(skb, sizeof(struct iphdr));
1031 		skb_reset_network_header(skb);
1032 		skb_reset_transport_header(skb);
1033 		msg = (struct igmpmsg *)skb_network_header(skb);
1034 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
1035 		msg->im_msgtype = assert;
1036 		msg->im_mbz = 0;
1037 		if (assert == IGMPMSG_WRVIFWHOLE) {
1038 			msg->im_vif = vifi;
1039 			msg->im_vif_hi = vifi >> 8;
1040 		} else {
1041 			msg->im_vif = mrt->mroute_reg_vif_num;
1042 			msg->im_vif_hi = mrt->mroute_reg_vif_num >> 8;
1043 		}
1044 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
1045 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
1046 					     sizeof(struct iphdr));
1047 	} else {
1048 		/* Copy the IP header */
1049 		skb_set_network_header(skb, skb->len);
1050 		skb_put(skb, ihl);
1051 		skb_copy_to_linear_data(skb, pkt->data, ihl);
1052 		/* Flag to the kernel this is a route add */
1053 		ip_hdr(skb)->protocol = 0;
1054 		msg = (struct igmpmsg *)skb_network_header(skb);
1055 		msg->im_vif = vifi;
1056 		msg->im_vif_hi = vifi >> 8;
1057 		skb_dst_set(skb, dst_clone(skb_dst(pkt)));
1058 		/* Add our header */
1059 		igmp = skb_put(skb, sizeof(struct igmphdr));
1060 		igmp->type = assert;
1061 		msg->im_msgtype = assert;
1062 		igmp->code = 0;
1063 		ip_hdr(skb)->tot_len = htons(skb->len);	/* Fix the length */
1064 		skb->transport_header = skb->network_header;
1065 	}
1066 
1067 	rcu_read_lock();
1068 	mroute_sk = rcu_dereference(mrt->mroute_sk);
1069 	if (!mroute_sk) {
1070 		rcu_read_unlock();
1071 		kfree_skb(skb);
1072 		return -EINVAL;
1073 	}
1074 
1075 	igmpmsg_netlink_event(mrt, skb);
1076 
1077 	/* Deliver to mrouted */
1078 	ret = sock_queue_rcv_skb(mroute_sk, skb);
1079 	rcu_read_unlock();
1080 	if (ret < 0) {
1081 		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1082 		kfree_skb(skb);
1083 	}
1084 
1085 	return ret;
1086 }
1087 
1088 /* Queue a packet for resolution. It gets locked cache entry! */
1089 static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
1090 				 struct sk_buff *skb, struct net_device *dev)
1091 {
1092 	const struct iphdr *iph = ip_hdr(skb);
1093 	struct mfc_cache *c;
1094 	bool found = false;
1095 	int err;
1096 
1097 	spin_lock_bh(&mfc_unres_lock);
1098 	list_for_each_entry(c, &mrt->mfc_unres_queue, _c.list) {
1099 		if (c->mfc_mcastgrp == iph->daddr &&
1100 		    c->mfc_origin == iph->saddr) {
1101 			found = true;
1102 			break;
1103 		}
1104 	}
1105 
1106 	if (!found) {
1107 		/* Create a new entry if allowable */
1108 		c = ipmr_cache_alloc_unres();
1109 		if (!c) {
1110 			spin_unlock_bh(&mfc_unres_lock);
1111 
1112 			kfree_skb(skb);
1113 			return -ENOBUFS;
1114 		}
1115 
1116 		/* Fill in the new cache entry */
1117 		c->_c.mfc_parent = -1;
1118 		c->mfc_origin	= iph->saddr;
1119 		c->mfc_mcastgrp	= iph->daddr;
1120 
1121 		/* Reflect first query at mrouted. */
1122 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1123 
1124 		if (err < 0) {
1125 			/* If the report failed throw the cache entry
1126 			   out - Brad Parker
1127 			 */
1128 			spin_unlock_bh(&mfc_unres_lock);
1129 
1130 			ipmr_cache_free(c);
1131 			kfree_skb(skb);
1132 			return err;
1133 		}
1134 
1135 		atomic_inc(&mrt->cache_resolve_queue_len);
1136 		list_add(&c->_c.list, &mrt->mfc_unres_queue);
1137 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1138 
1139 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1140 			mod_timer(&mrt->ipmr_expire_timer,
1141 				  c->_c.mfc_un.unres.expires);
1142 	}
1143 
1144 	/* See if we can append the packet */
1145 	if (c->_c.mfc_un.unres.unresolved.qlen > 3) {
1146 		kfree_skb(skb);
1147 		err = -ENOBUFS;
1148 	} else {
1149 		if (dev) {
1150 			skb->dev = dev;
1151 			skb->skb_iif = dev->ifindex;
1152 		}
1153 		skb_queue_tail(&c->_c.mfc_un.unres.unresolved, skb);
1154 		err = 0;
1155 	}
1156 
1157 	spin_unlock_bh(&mfc_unres_lock);
1158 	return err;
1159 }
1160 
1161 /* MFC cache manipulation by user space mroute daemon */
1162 
1163 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1164 {
1165 	struct net *net = read_pnet(&mrt->net);
1166 	struct mfc_cache *c;
1167 
1168 	/* The entries are added/deleted only under RTNL */
1169 	rcu_read_lock();
1170 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1171 				   mfc->mfcc_mcastgrp.s_addr, parent);
1172 	rcu_read_unlock();
1173 	if (!c)
1174 		return -ENOENT;
1175 	rhltable_remove(&mrt->mfc_hash, &c->_c.mnode, ipmr_rht_params);
1176 	list_del_rcu(&c->_c.list);
1177 	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, c, mrt->id);
1178 	mroute_netlink_event(mrt, c, RTM_DELROUTE);
1179 	mr_cache_put(&c->_c);
1180 
1181 	return 0;
1182 }
1183 
1184 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1185 			struct mfcctl *mfc, int mrtsock, int parent)
1186 {
1187 	struct mfc_cache *uc, *c;
1188 	struct mr_mfc *_uc;
1189 	bool found;
1190 	int ret;
1191 
1192 	if (mfc->mfcc_parent >= MAXVIFS)
1193 		return -ENFILE;
1194 
1195 	/* The entries are added/deleted only under RTNL */
1196 	rcu_read_lock();
1197 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1198 				   mfc->mfcc_mcastgrp.s_addr, parent);
1199 	rcu_read_unlock();
1200 	if (c) {
1201 		write_lock_bh(&mrt_lock);
1202 		c->_c.mfc_parent = mfc->mfcc_parent;
1203 		ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
1204 		if (!mrtsock)
1205 			c->_c.mfc_flags |= MFC_STATIC;
1206 		write_unlock_bh(&mrt_lock);
1207 		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, c,
1208 					      mrt->id);
1209 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1210 		return 0;
1211 	}
1212 
1213 	if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1214 	    !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1215 		return -EINVAL;
1216 
1217 	c = ipmr_cache_alloc();
1218 	if (!c)
1219 		return -ENOMEM;
1220 
1221 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1222 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1223 	c->_c.mfc_parent = mfc->mfcc_parent;
1224 	ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
1225 	if (!mrtsock)
1226 		c->_c.mfc_flags |= MFC_STATIC;
1227 
1228 	ret = rhltable_insert_key(&mrt->mfc_hash, &c->cmparg, &c->_c.mnode,
1229 				  ipmr_rht_params);
1230 	if (ret) {
1231 		pr_err("ipmr: rhtable insert error %d\n", ret);
1232 		ipmr_cache_free(c);
1233 		return ret;
1234 	}
1235 	list_add_tail_rcu(&c->_c.list, &mrt->mfc_cache_list);
1236 	/* Check to see if we resolved a queued list. If so we
1237 	 * need to send on the frames and tidy up.
1238 	 */
1239 	found = false;
1240 	spin_lock_bh(&mfc_unres_lock);
1241 	list_for_each_entry(_uc, &mrt->mfc_unres_queue, list) {
1242 		uc = (struct mfc_cache *)_uc;
1243 		if (uc->mfc_origin == c->mfc_origin &&
1244 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1245 			list_del(&_uc->list);
1246 			atomic_dec(&mrt->cache_resolve_queue_len);
1247 			found = true;
1248 			break;
1249 		}
1250 	}
1251 	if (list_empty(&mrt->mfc_unres_queue))
1252 		del_timer(&mrt->ipmr_expire_timer);
1253 	spin_unlock_bh(&mfc_unres_lock);
1254 
1255 	if (found) {
1256 		ipmr_cache_resolve(net, mrt, uc, c);
1257 		ipmr_cache_free(uc);
1258 	}
1259 	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, c, mrt->id);
1260 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1261 	return 0;
1262 }
1263 
1264 /* Close the multicast socket, and clear the vif tables etc */
1265 static void mroute_clean_tables(struct mr_table *mrt, int flags)
1266 {
1267 	struct net *net = read_pnet(&mrt->net);
1268 	struct mr_mfc *c, *tmp;
1269 	struct mfc_cache *cache;
1270 	LIST_HEAD(list);
1271 	int i;
1272 
1273 	/* Shut down all active vif entries */
1274 	if (flags & (MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC)) {
1275 		for (i = 0; i < mrt->maxvif; i++) {
1276 			if (((mrt->vif_table[i].flags & VIFF_STATIC) &&
1277 			     !(flags & MRT_FLUSH_VIFS_STATIC)) ||
1278 			    (!(mrt->vif_table[i].flags & VIFF_STATIC) && !(flags & MRT_FLUSH_VIFS)))
1279 				continue;
1280 			vif_delete(mrt, i, 0, &list);
1281 		}
1282 		unregister_netdevice_many(&list);
1283 	}
1284 
1285 	/* Wipe the cache */
1286 	if (flags & (MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC)) {
1287 		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
1288 			if (((c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC_STATIC)) ||
1289 			    (!(c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC)))
1290 				continue;
1291 			rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
1292 			list_del_rcu(&c->list);
1293 			cache = (struct mfc_cache *)c;
1294 			call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
1295 						      mrt->id);
1296 			mroute_netlink_event(mrt, cache, RTM_DELROUTE);
1297 			mr_cache_put(c);
1298 		}
1299 	}
1300 
1301 	if (flags & MRT_FLUSH_MFC) {
1302 		if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1303 			spin_lock_bh(&mfc_unres_lock);
1304 			list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
1305 				list_del(&c->list);
1306 				cache = (struct mfc_cache *)c;
1307 				mroute_netlink_event(mrt, cache, RTM_DELROUTE);
1308 				ipmr_destroy_unres(mrt, cache);
1309 			}
1310 			spin_unlock_bh(&mfc_unres_lock);
1311 		}
1312 	}
1313 }
1314 
1315 /* called from ip_ra_control(), before an RCU grace period,
1316  * we don't need to call synchronize_rcu() here
1317  */
1318 static void mrtsock_destruct(struct sock *sk)
1319 {
1320 	struct net *net = sock_net(sk);
1321 	struct mr_table *mrt;
1322 
1323 	rtnl_lock();
1324 	ipmr_for_each_table(mrt, net) {
1325 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1326 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1327 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1328 						    NETCONFA_MC_FORWARDING,
1329 						    NETCONFA_IFINDEX_ALL,
1330 						    net->ipv4.devconf_all);
1331 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1332 			mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_MFC);
1333 		}
1334 	}
1335 	rtnl_unlock();
1336 }
1337 
1338 /* Socket options and virtual interface manipulation. The whole
1339  * virtual interface system is a complete heap, but unfortunately
1340  * that's how BSD mrouted happens to think. Maybe one day with a proper
1341  * MOSPF/PIM router set up we can clean this up.
1342  */
1343 
1344 int ip_mroute_setsockopt(struct sock *sk, int optname, sockptr_t optval,
1345 			 unsigned int optlen)
1346 {
1347 	struct net *net = sock_net(sk);
1348 	int val, ret = 0, parent = 0;
1349 	struct mr_table *mrt;
1350 	struct vifctl vif;
1351 	struct mfcctl mfc;
1352 	bool do_wrvifwhole;
1353 	u32 uval;
1354 
1355 	/* There's one exception to the lock - MRT_DONE which needs to unlock */
1356 	rtnl_lock();
1357 	if (sk->sk_type != SOCK_RAW ||
1358 	    inet_sk(sk)->inet_num != IPPROTO_IGMP) {
1359 		ret = -EOPNOTSUPP;
1360 		goto out_unlock;
1361 	}
1362 
1363 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1364 	if (!mrt) {
1365 		ret = -ENOENT;
1366 		goto out_unlock;
1367 	}
1368 	if (optname != MRT_INIT) {
1369 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1370 		    !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
1371 			ret = -EACCES;
1372 			goto out_unlock;
1373 		}
1374 	}
1375 
1376 	switch (optname) {
1377 	case MRT_INIT:
1378 		if (optlen != sizeof(int)) {
1379 			ret = -EINVAL;
1380 			break;
1381 		}
1382 		if (rtnl_dereference(mrt->mroute_sk)) {
1383 			ret = -EADDRINUSE;
1384 			break;
1385 		}
1386 
1387 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1388 		if (ret == 0) {
1389 			rcu_assign_pointer(mrt->mroute_sk, sk);
1390 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1391 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1392 						    NETCONFA_MC_FORWARDING,
1393 						    NETCONFA_IFINDEX_ALL,
1394 						    net->ipv4.devconf_all);
1395 		}
1396 		break;
1397 	case MRT_DONE:
1398 		if (sk != rcu_access_pointer(mrt->mroute_sk)) {
1399 			ret = -EACCES;
1400 		} else {
1401 			/* We need to unlock here because mrtsock_destruct takes
1402 			 * care of rtnl itself and we can't change that due to
1403 			 * the IP_ROUTER_ALERT setsockopt which runs without it.
1404 			 */
1405 			rtnl_unlock();
1406 			ret = ip_ra_control(sk, 0, NULL);
1407 			goto out;
1408 		}
1409 		break;
1410 	case MRT_ADD_VIF:
1411 	case MRT_DEL_VIF:
1412 		if (optlen != sizeof(vif)) {
1413 			ret = -EINVAL;
1414 			break;
1415 		}
1416 		if (copy_from_sockptr(&vif, optval, sizeof(vif))) {
1417 			ret = -EFAULT;
1418 			break;
1419 		}
1420 		if (vif.vifc_vifi >= MAXVIFS) {
1421 			ret = -ENFILE;
1422 			break;
1423 		}
1424 		if (optname == MRT_ADD_VIF) {
1425 			ret = vif_add(net, mrt, &vif,
1426 				      sk == rtnl_dereference(mrt->mroute_sk));
1427 		} else {
1428 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1429 		}
1430 		break;
1431 	/* Manipulate the forwarding caches. These live
1432 	 * in a sort of kernel/user symbiosis.
1433 	 */
1434 	case MRT_ADD_MFC:
1435 	case MRT_DEL_MFC:
1436 		parent = -1;
1437 		fallthrough;
1438 	case MRT_ADD_MFC_PROXY:
1439 	case MRT_DEL_MFC_PROXY:
1440 		if (optlen != sizeof(mfc)) {
1441 			ret = -EINVAL;
1442 			break;
1443 		}
1444 		if (copy_from_sockptr(&mfc, optval, sizeof(mfc))) {
1445 			ret = -EFAULT;
1446 			break;
1447 		}
1448 		if (parent == 0)
1449 			parent = mfc.mfcc_parent;
1450 		if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1451 			ret = ipmr_mfc_delete(mrt, &mfc, parent);
1452 		else
1453 			ret = ipmr_mfc_add(net, mrt, &mfc,
1454 					   sk == rtnl_dereference(mrt->mroute_sk),
1455 					   parent);
1456 		break;
1457 	case MRT_FLUSH:
1458 		if (optlen != sizeof(val)) {
1459 			ret = -EINVAL;
1460 			break;
1461 		}
1462 		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1463 			ret = -EFAULT;
1464 			break;
1465 		}
1466 		mroute_clean_tables(mrt, val);
1467 		break;
1468 	/* Control PIM assert. */
1469 	case MRT_ASSERT:
1470 		if (optlen != sizeof(val)) {
1471 			ret = -EINVAL;
1472 			break;
1473 		}
1474 		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1475 			ret = -EFAULT;
1476 			break;
1477 		}
1478 		mrt->mroute_do_assert = val;
1479 		break;
1480 	case MRT_PIM:
1481 		if (!ipmr_pimsm_enabled()) {
1482 			ret = -ENOPROTOOPT;
1483 			break;
1484 		}
1485 		if (optlen != sizeof(val)) {
1486 			ret = -EINVAL;
1487 			break;
1488 		}
1489 		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1490 			ret = -EFAULT;
1491 			break;
1492 		}
1493 
1494 		do_wrvifwhole = (val == IGMPMSG_WRVIFWHOLE);
1495 		val = !!val;
1496 		if (val != mrt->mroute_do_pim) {
1497 			mrt->mroute_do_pim = val;
1498 			mrt->mroute_do_assert = val;
1499 			mrt->mroute_do_wrvifwhole = do_wrvifwhole;
1500 		}
1501 		break;
1502 	case MRT_TABLE:
1503 		if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) {
1504 			ret = -ENOPROTOOPT;
1505 			break;
1506 		}
1507 		if (optlen != sizeof(uval)) {
1508 			ret = -EINVAL;
1509 			break;
1510 		}
1511 		if (copy_from_sockptr(&uval, optval, sizeof(uval))) {
1512 			ret = -EFAULT;
1513 			break;
1514 		}
1515 
1516 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1517 			ret = -EBUSY;
1518 		} else {
1519 			mrt = ipmr_new_table(net, uval);
1520 			if (IS_ERR(mrt))
1521 				ret = PTR_ERR(mrt);
1522 			else
1523 				raw_sk(sk)->ipmr_table = uval;
1524 		}
1525 		break;
1526 	/* Spurious command, or MRT_VERSION which you cannot set. */
1527 	default:
1528 		ret = -ENOPROTOOPT;
1529 	}
1530 out_unlock:
1531 	rtnl_unlock();
1532 out:
1533 	return ret;
1534 }
1535 
1536 /* Getsock opt support for the multicast routing system. */
1537 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1538 {
1539 	int olr;
1540 	int val;
1541 	struct net *net = sock_net(sk);
1542 	struct mr_table *mrt;
1543 
1544 	if (sk->sk_type != SOCK_RAW ||
1545 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1546 		return -EOPNOTSUPP;
1547 
1548 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1549 	if (!mrt)
1550 		return -ENOENT;
1551 
1552 	switch (optname) {
1553 	case MRT_VERSION:
1554 		val = 0x0305;
1555 		break;
1556 	case MRT_PIM:
1557 		if (!ipmr_pimsm_enabled())
1558 			return -ENOPROTOOPT;
1559 		val = mrt->mroute_do_pim;
1560 		break;
1561 	case MRT_ASSERT:
1562 		val = mrt->mroute_do_assert;
1563 		break;
1564 	default:
1565 		return -ENOPROTOOPT;
1566 	}
1567 
1568 	if (get_user(olr, optlen))
1569 		return -EFAULT;
1570 	olr = min_t(unsigned int, olr, sizeof(int));
1571 	if (olr < 0)
1572 		return -EINVAL;
1573 	if (put_user(olr, optlen))
1574 		return -EFAULT;
1575 	if (copy_to_user(optval, &val, olr))
1576 		return -EFAULT;
1577 	return 0;
1578 }
1579 
1580 /* The IP multicast ioctl support routines. */
1581 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1582 {
1583 	struct sioc_sg_req sr;
1584 	struct sioc_vif_req vr;
1585 	struct vif_device *vif;
1586 	struct mfc_cache *c;
1587 	struct net *net = sock_net(sk);
1588 	struct mr_table *mrt;
1589 
1590 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1591 	if (!mrt)
1592 		return -ENOENT;
1593 
1594 	switch (cmd) {
1595 	case SIOCGETVIFCNT:
1596 		if (copy_from_user(&vr, arg, sizeof(vr)))
1597 			return -EFAULT;
1598 		if (vr.vifi >= mrt->maxvif)
1599 			return -EINVAL;
1600 		vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif);
1601 		read_lock(&mrt_lock);
1602 		vif = &mrt->vif_table[vr.vifi];
1603 		if (VIF_EXISTS(mrt, vr.vifi)) {
1604 			vr.icount = vif->pkt_in;
1605 			vr.ocount = vif->pkt_out;
1606 			vr.ibytes = vif->bytes_in;
1607 			vr.obytes = vif->bytes_out;
1608 			read_unlock(&mrt_lock);
1609 
1610 			if (copy_to_user(arg, &vr, sizeof(vr)))
1611 				return -EFAULT;
1612 			return 0;
1613 		}
1614 		read_unlock(&mrt_lock);
1615 		return -EADDRNOTAVAIL;
1616 	case SIOCGETSGCNT:
1617 		if (copy_from_user(&sr, arg, sizeof(sr)))
1618 			return -EFAULT;
1619 
1620 		rcu_read_lock();
1621 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1622 		if (c) {
1623 			sr.pktcnt = c->_c.mfc_un.res.pkt;
1624 			sr.bytecnt = c->_c.mfc_un.res.bytes;
1625 			sr.wrong_if = c->_c.mfc_un.res.wrong_if;
1626 			rcu_read_unlock();
1627 
1628 			if (copy_to_user(arg, &sr, sizeof(sr)))
1629 				return -EFAULT;
1630 			return 0;
1631 		}
1632 		rcu_read_unlock();
1633 		return -EADDRNOTAVAIL;
1634 	default:
1635 		return -ENOIOCTLCMD;
1636 	}
1637 }
1638 
1639 #ifdef CONFIG_COMPAT
1640 struct compat_sioc_sg_req {
1641 	struct in_addr src;
1642 	struct in_addr grp;
1643 	compat_ulong_t pktcnt;
1644 	compat_ulong_t bytecnt;
1645 	compat_ulong_t wrong_if;
1646 };
1647 
1648 struct compat_sioc_vif_req {
1649 	vifi_t	vifi;		/* Which iface */
1650 	compat_ulong_t icount;
1651 	compat_ulong_t ocount;
1652 	compat_ulong_t ibytes;
1653 	compat_ulong_t obytes;
1654 };
1655 
1656 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1657 {
1658 	struct compat_sioc_sg_req sr;
1659 	struct compat_sioc_vif_req vr;
1660 	struct vif_device *vif;
1661 	struct mfc_cache *c;
1662 	struct net *net = sock_net(sk);
1663 	struct mr_table *mrt;
1664 
1665 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1666 	if (!mrt)
1667 		return -ENOENT;
1668 
1669 	switch (cmd) {
1670 	case SIOCGETVIFCNT:
1671 		if (copy_from_user(&vr, arg, sizeof(vr)))
1672 			return -EFAULT;
1673 		if (vr.vifi >= mrt->maxvif)
1674 			return -EINVAL;
1675 		vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif);
1676 		read_lock(&mrt_lock);
1677 		vif = &mrt->vif_table[vr.vifi];
1678 		if (VIF_EXISTS(mrt, vr.vifi)) {
1679 			vr.icount = vif->pkt_in;
1680 			vr.ocount = vif->pkt_out;
1681 			vr.ibytes = vif->bytes_in;
1682 			vr.obytes = vif->bytes_out;
1683 			read_unlock(&mrt_lock);
1684 
1685 			if (copy_to_user(arg, &vr, sizeof(vr)))
1686 				return -EFAULT;
1687 			return 0;
1688 		}
1689 		read_unlock(&mrt_lock);
1690 		return -EADDRNOTAVAIL;
1691 	case SIOCGETSGCNT:
1692 		if (copy_from_user(&sr, arg, sizeof(sr)))
1693 			return -EFAULT;
1694 
1695 		rcu_read_lock();
1696 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1697 		if (c) {
1698 			sr.pktcnt = c->_c.mfc_un.res.pkt;
1699 			sr.bytecnt = c->_c.mfc_un.res.bytes;
1700 			sr.wrong_if = c->_c.mfc_un.res.wrong_if;
1701 			rcu_read_unlock();
1702 
1703 			if (copy_to_user(arg, &sr, sizeof(sr)))
1704 				return -EFAULT;
1705 			return 0;
1706 		}
1707 		rcu_read_unlock();
1708 		return -EADDRNOTAVAIL;
1709 	default:
1710 		return -ENOIOCTLCMD;
1711 	}
1712 }
1713 #endif
1714 
1715 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1716 {
1717 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1718 	struct net *net = dev_net(dev);
1719 	struct mr_table *mrt;
1720 	struct vif_device *v;
1721 	int ct;
1722 
1723 	if (event != NETDEV_UNREGISTER)
1724 		return NOTIFY_DONE;
1725 
1726 	ipmr_for_each_table(mrt, net) {
1727 		v = &mrt->vif_table[0];
1728 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1729 			if (v->dev == dev)
1730 				vif_delete(mrt, ct, 1, NULL);
1731 		}
1732 	}
1733 	return NOTIFY_DONE;
1734 }
1735 
1736 static struct notifier_block ip_mr_notifier = {
1737 	.notifier_call = ipmr_device_event,
1738 };
1739 
1740 /* Encapsulate a packet by attaching a valid IPIP header to it.
1741  * This avoids tunnel drivers and other mess and gives us the speed so
1742  * important for multicast video.
1743  */
1744 static void ip_encap(struct net *net, struct sk_buff *skb,
1745 		     __be32 saddr, __be32 daddr)
1746 {
1747 	struct iphdr *iph;
1748 	const struct iphdr *old_iph = ip_hdr(skb);
1749 
1750 	skb_push(skb, sizeof(struct iphdr));
1751 	skb->transport_header = skb->network_header;
1752 	skb_reset_network_header(skb);
1753 	iph = ip_hdr(skb);
1754 
1755 	iph->version	=	4;
1756 	iph->tos	=	old_iph->tos;
1757 	iph->ttl	=	old_iph->ttl;
1758 	iph->frag_off	=	0;
1759 	iph->daddr	=	daddr;
1760 	iph->saddr	=	saddr;
1761 	iph->protocol	=	IPPROTO_IPIP;
1762 	iph->ihl	=	5;
1763 	iph->tot_len	=	htons(skb->len);
1764 	ip_select_ident(net, skb, NULL);
1765 	ip_send_check(iph);
1766 
1767 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1768 	nf_reset_ct(skb);
1769 }
1770 
1771 static inline int ipmr_forward_finish(struct net *net, struct sock *sk,
1772 				      struct sk_buff *skb)
1773 {
1774 	struct ip_options *opt = &(IPCB(skb)->opt);
1775 
1776 	IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
1777 	IP_ADD_STATS(net, IPSTATS_MIB_OUTOCTETS, skb->len);
1778 
1779 	if (unlikely(opt->optlen))
1780 		ip_forward_options(skb);
1781 
1782 	return dst_output(net, sk, skb);
1783 }
1784 
1785 #ifdef CONFIG_NET_SWITCHDEV
1786 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1787 				   int in_vifi, int out_vifi)
1788 {
1789 	struct vif_device *out_vif = &mrt->vif_table[out_vifi];
1790 	struct vif_device *in_vif = &mrt->vif_table[in_vifi];
1791 
1792 	if (!skb->offload_l3_fwd_mark)
1793 		return false;
1794 	if (!out_vif->dev_parent_id.id_len || !in_vif->dev_parent_id.id_len)
1795 		return false;
1796 	return netdev_phys_item_id_same(&out_vif->dev_parent_id,
1797 					&in_vif->dev_parent_id);
1798 }
1799 #else
1800 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1801 				   int in_vifi, int out_vifi)
1802 {
1803 	return false;
1804 }
1805 #endif
1806 
1807 /* Processing handlers for ipmr_forward */
1808 
1809 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1810 			    int in_vifi, struct sk_buff *skb, int vifi)
1811 {
1812 	const struct iphdr *iph = ip_hdr(skb);
1813 	struct vif_device *vif = &mrt->vif_table[vifi];
1814 	struct net_device *dev;
1815 	struct rtable *rt;
1816 	struct flowi4 fl4;
1817 	int    encap = 0;
1818 
1819 	if (!vif->dev)
1820 		goto out_free;
1821 
1822 	if (vif->flags & VIFF_REGISTER) {
1823 		vif->pkt_out++;
1824 		vif->bytes_out += skb->len;
1825 		vif->dev->stats.tx_bytes += skb->len;
1826 		vif->dev->stats.tx_packets++;
1827 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1828 		goto out_free;
1829 	}
1830 
1831 	if (ipmr_forward_offloaded(skb, mrt, in_vifi, vifi))
1832 		goto out_free;
1833 
1834 	if (vif->flags & VIFF_TUNNEL) {
1835 		rt = ip_route_output_ports(net, &fl4, NULL,
1836 					   vif->remote, vif->local,
1837 					   0, 0,
1838 					   IPPROTO_IPIP,
1839 					   RT_TOS(iph->tos), vif->link);
1840 		if (IS_ERR(rt))
1841 			goto out_free;
1842 		encap = sizeof(struct iphdr);
1843 	} else {
1844 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1845 					   0, 0,
1846 					   IPPROTO_IPIP,
1847 					   RT_TOS(iph->tos), vif->link);
1848 		if (IS_ERR(rt))
1849 			goto out_free;
1850 	}
1851 
1852 	dev = rt->dst.dev;
1853 
1854 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1855 		/* Do not fragment multicasts. Alas, IPv4 does not
1856 		 * allow to send ICMP, so that packets will disappear
1857 		 * to blackhole.
1858 		 */
1859 		IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
1860 		ip_rt_put(rt);
1861 		goto out_free;
1862 	}
1863 
1864 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1865 
1866 	if (skb_cow(skb, encap)) {
1867 		ip_rt_put(rt);
1868 		goto out_free;
1869 	}
1870 
1871 	vif->pkt_out++;
1872 	vif->bytes_out += skb->len;
1873 
1874 	skb_dst_drop(skb);
1875 	skb_dst_set(skb, &rt->dst);
1876 	ip_decrease_ttl(ip_hdr(skb));
1877 
1878 	/* FIXME: forward and output firewalls used to be called here.
1879 	 * What do we do with netfilter? -- RR
1880 	 */
1881 	if (vif->flags & VIFF_TUNNEL) {
1882 		ip_encap(net, skb, vif->local, vif->remote);
1883 		/* FIXME: extra output firewall step used to be here. --RR */
1884 		vif->dev->stats.tx_packets++;
1885 		vif->dev->stats.tx_bytes += skb->len;
1886 	}
1887 
1888 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1889 
1890 	/* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1891 	 * not only before forwarding, but after forwarding on all output
1892 	 * interfaces. It is clear, if mrouter runs a multicasting
1893 	 * program, it should receive packets not depending to what interface
1894 	 * program is joined.
1895 	 * If we will not make it, the program will have to join on all
1896 	 * interfaces. On the other hand, multihoming host (or router, but
1897 	 * not mrouter) cannot join to more than one interface - it will
1898 	 * result in receiving multiple packets.
1899 	 */
1900 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
1901 		net, NULL, skb, skb->dev, dev,
1902 		ipmr_forward_finish);
1903 	return;
1904 
1905 out_free:
1906 	kfree_skb(skb);
1907 }
1908 
1909 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1910 {
1911 	int ct;
1912 
1913 	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1914 		if (mrt->vif_table[ct].dev == dev)
1915 			break;
1916 	}
1917 	return ct;
1918 }
1919 
1920 /* "local" means that we should preserve one skb (for local delivery) */
1921 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
1922 			  struct net_device *dev, struct sk_buff *skb,
1923 			  struct mfc_cache *c, int local)
1924 {
1925 	int true_vifi = ipmr_find_vif(mrt, dev);
1926 	int psend = -1;
1927 	int vif, ct;
1928 
1929 	vif = c->_c.mfc_parent;
1930 	c->_c.mfc_un.res.pkt++;
1931 	c->_c.mfc_un.res.bytes += skb->len;
1932 	c->_c.mfc_un.res.lastuse = jiffies;
1933 
1934 	if (c->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
1935 		struct mfc_cache *cache_proxy;
1936 
1937 		/* For an (*,G) entry, we only check that the incoming
1938 		 * interface is part of the static tree.
1939 		 */
1940 		cache_proxy = mr_mfc_find_any_parent(mrt, vif);
1941 		if (cache_proxy &&
1942 		    cache_proxy->_c.mfc_un.res.ttls[true_vifi] < 255)
1943 			goto forward;
1944 	}
1945 
1946 	/* Wrong interface: drop packet and (maybe) send PIM assert. */
1947 	if (mrt->vif_table[vif].dev != dev) {
1948 		if (rt_is_output_route(skb_rtable(skb))) {
1949 			/* It is our own packet, looped back.
1950 			 * Very complicated situation...
1951 			 *
1952 			 * The best workaround until routing daemons will be
1953 			 * fixed is not to redistribute packet, if it was
1954 			 * send through wrong interface. It means, that
1955 			 * multicast applications WILL NOT work for
1956 			 * (S,G), which have default multicast route pointing
1957 			 * to wrong oif. In any case, it is not a good
1958 			 * idea to use multicasting applications on router.
1959 			 */
1960 			goto dont_forward;
1961 		}
1962 
1963 		c->_c.mfc_un.res.wrong_if++;
1964 
1965 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
1966 		    /* pimsm uses asserts, when switching from RPT to SPT,
1967 		     * so that we cannot check that packet arrived on an oif.
1968 		     * It is bad, but otherwise we would need to move pretty
1969 		     * large chunk of pimd to kernel. Ough... --ANK
1970 		     */
1971 		    (mrt->mroute_do_pim ||
1972 		     c->_c.mfc_un.res.ttls[true_vifi] < 255) &&
1973 		    time_after(jiffies,
1974 			       c->_c.mfc_un.res.last_assert +
1975 			       MFC_ASSERT_THRESH)) {
1976 			c->_c.mfc_un.res.last_assert = jiffies;
1977 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1978 			if (mrt->mroute_do_wrvifwhole)
1979 				ipmr_cache_report(mrt, skb, true_vifi,
1980 						  IGMPMSG_WRVIFWHOLE);
1981 		}
1982 		goto dont_forward;
1983 	}
1984 
1985 forward:
1986 	mrt->vif_table[vif].pkt_in++;
1987 	mrt->vif_table[vif].bytes_in += skb->len;
1988 
1989 	/* Forward the frame */
1990 	if (c->mfc_origin == htonl(INADDR_ANY) &&
1991 	    c->mfc_mcastgrp == htonl(INADDR_ANY)) {
1992 		if (true_vifi >= 0 &&
1993 		    true_vifi != c->_c.mfc_parent &&
1994 		    ip_hdr(skb)->ttl >
1995 				c->_c.mfc_un.res.ttls[c->_c.mfc_parent]) {
1996 			/* It's an (*,*) entry and the packet is not coming from
1997 			 * the upstream: forward the packet to the upstream
1998 			 * only.
1999 			 */
2000 			psend = c->_c.mfc_parent;
2001 			goto last_forward;
2002 		}
2003 		goto dont_forward;
2004 	}
2005 	for (ct = c->_c.mfc_un.res.maxvif - 1;
2006 	     ct >= c->_c.mfc_un.res.minvif; ct--) {
2007 		/* For (*,G) entry, don't forward to the incoming interface */
2008 		if ((c->mfc_origin != htonl(INADDR_ANY) ||
2009 		     ct != true_vifi) &&
2010 		    ip_hdr(skb)->ttl > c->_c.mfc_un.res.ttls[ct]) {
2011 			if (psend != -1) {
2012 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2013 
2014 				if (skb2)
2015 					ipmr_queue_xmit(net, mrt, true_vifi,
2016 							skb2, psend);
2017 			}
2018 			psend = ct;
2019 		}
2020 	}
2021 last_forward:
2022 	if (psend != -1) {
2023 		if (local) {
2024 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2025 
2026 			if (skb2)
2027 				ipmr_queue_xmit(net, mrt, true_vifi, skb2,
2028 						psend);
2029 		} else {
2030 			ipmr_queue_xmit(net, mrt, true_vifi, skb, psend);
2031 			return;
2032 		}
2033 	}
2034 
2035 dont_forward:
2036 	if (!local)
2037 		kfree_skb(skb);
2038 }
2039 
2040 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
2041 {
2042 	struct rtable *rt = skb_rtable(skb);
2043 	struct iphdr *iph = ip_hdr(skb);
2044 	struct flowi4 fl4 = {
2045 		.daddr = iph->daddr,
2046 		.saddr = iph->saddr,
2047 		.flowi4_tos = RT_TOS(iph->tos),
2048 		.flowi4_oif = (rt_is_output_route(rt) ?
2049 			       skb->dev->ifindex : 0),
2050 		.flowi4_iif = (rt_is_output_route(rt) ?
2051 			       LOOPBACK_IFINDEX :
2052 			       skb->dev->ifindex),
2053 		.flowi4_mark = skb->mark,
2054 	};
2055 	struct mr_table *mrt;
2056 	int err;
2057 
2058 	err = ipmr_fib_lookup(net, &fl4, &mrt);
2059 	if (err)
2060 		return ERR_PTR(err);
2061 	return mrt;
2062 }
2063 
2064 /* Multicast packets for forwarding arrive here
2065  * Called with rcu_read_lock();
2066  */
2067 int ip_mr_input(struct sk_buff *skb)
2068 {
2069 	struct mfc_cache *cache;
2070 	struct net *net = dev_net(skb->dev);
2071 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
2072 	struct mr_table *mrt;
2073 	struct net_device *dev;
2074 
2075 	/* skb->dev passed in is the loX master dev for vrfs.
2076 	 * As there are no vifs associated with loopback devices,
2077 	 * get the proper interface that does have a vif associated with it.
2078 	 */
2079 	dev = skb->dev;
2080 	if (netif_is_l3_master(skb->dev)) {
2081 		dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
2082 		if (!dev) {
2083 			kfree_skb(skb);
2084 			return -ENODEV;
2085 		}
2086 	}
2087 
2088 	/* Packet is looped back after forward, it should not be
2089 	 * forwarded second time, but still can be delivered locally.
2090 	 */
2091 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
2092 		goto dont_forward;
2093 
2094 	mrt = ipmr_rt_fib_lookup(net, skb);
2095 	if (IS_ERR(mrt)) {
2096 		kfree_skb(skb);
2097 		return PTR_ERR(mrt);
2098 	}
2099 	if (!local) {
2100 		if (IPCB(skb)->opt.router_alert) {
2101 			if (ip_call_ra_chain(skb))
2102 				return 0;
2103 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
2104 			/* IGMPv1 (and broken IGMPv2 implementations sort of
2105 			 * Cisco IOS <= 11.2(8)) do not put router alert
2106 			 * option to IGMP packets destined to routable
2107 			 * groups. It is very bad, because it means
2108 			 * that we can forward NO IGMP messages.
2109 			 */
2110 			struct sock *mroute_sk;
2111 
2112 			mroute_sk = rcu_dereference(mrt->mroute_sk);
2113 			if (mroute_sk) {
2114 				nf_reset_ct(skb);
2115 				raw_rcv(mroute_sk, skb);
2116 				return 0;
2117 			}
2118 		}
2119 	}
2120 
2121 	/* already under rcu_read_lock() */
2122 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
2123 	if (!cache) {
2124 		int vif = ipmr_find_vif(mrt, dev);
2125 
2126 		if (vif >= 0)
2127 			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
2128 						    vif);
2129 	}
2130 
2131 	/* No usable cache entry */
2132 	if (!cache) {
2133 		int vif;
2134 
2135 		if (local) {
2136 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2137 			ip_local_deliver(skb);
2138 			if (!skb2)
2139 				return -ENOBUFS;
2140 			skb = skb2;
2141 		}
2142 
2143 		read_lock(&mrt_lock);
2144 		vif = ipmr_find_vif(mrt, dev);
2145 		if (vif >= 0) {
2146 			int err2 = ipmr_cache_unresolved(mrt, vif, skb, dev);
2147 			read_unlock(&mrt_lock);
2148 
2149 			return err2;
2150 		}
2151 		read_unlock(&mrt_lock);
2152 		kfree_skb(skb);
2153 		return -ENODEV;
2154 	}
2155 
2156 	read_lock(&mrt_lock);
2157 	ip_mr_forward(net, mrt, dev, skb, cache, local);
2158 	read_unlock(&mrt_lock);
2159 
2160 	if (local)
2161 		return ip_local_deliver(skb);
2162 
2163 	return 0;
2164 
2165 dont_forward:
2166 	if (local)
2167 		return ip_local_deliver(skb);
2168 	kfree_skb(skb);
2169 	return 0;
2170 }
2171 
2172 #ifdef CONFIG_IP_PIMSM_V1
2173 /* Handle IGMP messages of PIMv1 */
2174 int pim_rcv_v1(struct sk_buff *skb)
2175 {
2176 	struct igmphdr *pim;
2177 	struct net *net = dev_net(skb->dev);
2178 	struct mr_table *mrt;
2179 
2180 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2181 		goto drop;
2182 
2183 	pim = igmp_hdr(skb);
2184 
2185 	mrt = ipmr_rt_fib_lookup(net, skb);
2186 	if (IS_ERR(mrt))
2187 		goto drop;
2188 	if (!mrt->mroute_do_pim ||
2189 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2190 		goto drop;
2191 
2192 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2193 drop:
2194 		kfree_skb(skb);
2195 	}
2196 	return 0;
2197 }
2198 #endif
2199 
2200 #ifdef CONFIG_IP_PIMSM_V2
2201 static int pim_rcv(struct sk_buff *skb)
2202 {
2203 	struct pimreghdr *pim;
2204 	struct net *net = dev_net(skb->dev);
2205 	struct mr_table *mrt;
2206 
2207 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2208 		goto drop;
2209 
2210 	pim = (struct pimreghdr *)skb_transport_header(skb);
2211 	if (pim->type != ((PIM_VERSION << 4) | (PIM_TYPE_REGISTER)) ||
2212 	    (pim->flags & PIM_NULL_REGISTER) ||
2213 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2214 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2215 		goto drop;
2216 
2217 	mrt = ipmr_rt_fib_lookup(net, skb);
2218 	if (IS_ERR(mrt))
2219 		goto drop;
2220 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2221 drop:
2222 		kfree_skb(skb);
2223 	}
2224 	return 0;
2225 }
2226 #endif
2227 
2228 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2229 		   __be32 saddr, __be32 daddr,
2230 		   struct rtmsg *rtm, u32 portid)
2231 {
2232 	struct mfc_cache *cache;
2233 	struct mr_table *mrt;
2234 	int err;
2235 
2236 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2237 	if (!mrt)
2238 		return -ENOENT;
2239 
2240 	rcu_read_lock();
2241 	cache = ipmr_cache_find(mrt, saddr, daddr);
2242 	if (!cache && skb->dev) {
2243 		int vif = ipmr_find_vif(mrt, skb->dev);
2244 
2245 		if (vif >= 0)
2246 			cache = ipmr_cache_find_any(mrt, daddr, vif);
2247 	}
2248 	if (!cache) {
2249 		struct sk_buff *skb2;
2250 		struct iphdr *iph;
2251 		struct net_device *dev;
2252 		int vif = -1;
2253 
2254 		dev = skb->dev;
2255 		read_lock(&mrt_lock);
2256 		if (dev)
2257 			vif = ipmr_find_vif(mrt, dev);
2258 		if (vif < 0) {
2259 			read_unlock(&mrt_lock);
2260 			rcu_read_unlock();
2261 			return -ENODEV;
2262 		}
2263 
2264 		skb2 = skb_realloc_headroom(skb, sizeof(struct iphdr));
2265 		if (!skb2) {
2266 			read_unlock(&mrt_lock);
2267 			rcu_read_unlock();
2268 			return -ENOMEM;
2269 		}
2270 
2271 		NETLINK_CB(skb2).portid = portid;
2272 		skb_push(skb2, sizeof(struct iphdr));
2273 		skb_reset_network_header(skb2);
2274 		iph = ip_hdr(skb2);
2275 		iph->ihl = sizeof(struct iphdr) >> 2;
2276 		iph->saddr = saddr;
2277 		iph->daddr = daddr;
2278 		iph->version = 0;
2279 		err = ipmr_cache_unresolved(mrt, vif, skb2, dev);
2280 		read_unlock(&mrt_lock);
2281 		rcu_read_unlock();
2282 		return err;
2283 	}
2284 
2285 	read_lock(&mrt_lock);
2286 	err = mr_fill_mroute(mrt, skb, &cache->_c, rtm);
2287 	read_unlock(&mrt_lock);
2288 	rcu_read_unlock();
2289 	return err;
2290 }
2291 
2292 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2293 			    u32 portid, u32 seq, struct mfc_cache *c, int cmd,
2294 			    int flags)
2295 {
2296 	struct nlmsghdr *nlh;
2297 	struct rtmsg *rtm;
2298 	int err;
2299 
2300 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2301 	if (!nlh)
2302 		return -EMSGSIZE;
2303 
2304 	rtm = nlmsg_data(nlh);
2305 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2306 	rtm->rtm_dst_len  = 32;
2307 	rtm->rtm_src_len  = 32;
2308 	rtm->rtm_tos      = 0;
2309 	rtm->rtm_table    = mrt->id;
2310 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2311 		goto nla_put_failure;
2312 	rtm->rtm_type     = RTN_MULTICAST;
2313 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2314 	if (c->_c.mfc_flags & MFC_STATIC)
2315 		rtm->rtm_protocol = RTPROT_STATIC;
2316 	else
2317 		rtm->rtm_protocol = RTPROT_MROUTED;
2318 	rtm->rtm_flags    = 0;
2319 
2320 	if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
2321 	    nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
2322 		goto nla_put_failure;
2323 	err = mr_fill_mroute(mrt, skb, &c->_c, rtm);
2324 	/* do not break the dump if cache is unresolved */
2325 	if (err < 0 && err != -ENOENT)
2326 		goto nla_put_failure;
2327 
2328 	nlmsg_end(skb, nlh);
2329 	return 0;
2330 
2331 nla_put_failure:
2332 	nlmsg_cancel(skb, nlh);
2333 	return -EMSGSIZE;
2334 }
2335 
2336 static int _ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2337 			     u32 portid, u32 seq, struct mr_mfc *c, int cmd,
2338 			     int flags)
2339 {
2340 	return ipmr_fill_mroute(mrt, skb, portid, seq, (struct mfc_cache *)c,
2341 				cmd, flags);
2342 }
2343 
2344 static size_t mroute_msgsize(bool unresolved, int maxvif)
2345 {
2346 	size_t len =
2347 		NLMSG_ALIGN(sizeof(struct rtmsg))
2348 		+ nla_total_size(4)	/* RTA_TABLE */
2349 		+ nla_total_size(4)	/* RTA_SRC */
2350 		+ nla_total_size(4)	/* RTA_DST */
2351 		;
2352 
2353 	if (!unresolved)
2354 		len = len
2355 		      + nla_total_size(4)	/* RTA_IIF */
2356 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2357 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2358 						/* RTA_MFC_STATS */
2359 		      + nla_total_size_64bit(sizeof(struct rta_mfc_stats))
2360 		;
2361 
2362 	return len;
2363 }
2364 
2365 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2366 				 int cmd)
2367 {
2368 	struct net *net = read_pnet(&mrt->net);
2369 	struct sk_buff *skb;
2370 	int err = -ENOBUFS;
2371 
2372 	skb = nlmsg_new(mroute_msgsize(mfc->_c.mfc_parent >= MAXVIFS,
2373 				       mrt->maxvif),
2374 			GFP_ATOMIC);
2375 	if (!skb)
2376 		goto errout;
2377 
2378 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2379 	if (err < 0)
2380 		goto errout;
2381 
2382 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2383 	return;
2384 
2385 errout:
2386 	kfree_skb(skb);
2387 	if (err < 0)
2388 		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2389 }
2390 
2391 static size_t igmpmsg_netlink_msgsize(size_t payloadlen)
2392 {
2393 	size_t len =
2394 		NLMSG_ALIGN(sizeof(struct rtgenmsg))
2395 		+ nla_total_size(1)	/* IPMRA_CREPORT_MSGTYPE */
2396 		+ nla_total_size(4)	/* IPMRA_CREPORT_VIF_ID */
2397 		+ nla_total_size(4)	/* IPMRA_CREPORT_SRC_ADDR */
2398 		+ nla_total_size(4)	/* IPMRA_CREPORT_DST_ADDR */
2399 		+ nla_total_size(4)	/* IPMRA_CREPORT_TABLE */
2400 					/* IPMRA_CREPORT_PKT */
2401 		+ nla_total_size(payloadlen)
2402 		;
2403 
2404 	return len;
2405 }
2406 
2407 static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt)
2408 {
2409 	struct net *net = read_pnet(&mrt->net);
2410 	struct nlmsghdr *nlh;
2411 	struct rtgenmsg *rtgenm;
2412 	struct igmpmsg *msg;
2413 	struct sk_buff *skb;
2414 	struct nlattr *nla;
2415 	int payloadlen;
2416 
2417 	payloadlen = pkt->len - sizeof(struct igmpmsg);
2418 	msg = (struct igmpmsg *)skb_network_header(pkt);
2419 
2420 	skb = nlmsg_new(igmpmsg_netlink_msgsize(payloadlen), GFP_ATOMIC);
2421 	if (!skb)
2422 		goto errout;
2423 
2424 	nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT,
2425 			sizeof(struct rtgenmsg), 0);
2426 	if (!nlh)
2427 		goto errout;
2428 	rtgenm = nlmsg_data(nlh);
2429 	rtgenm->rtgen_family = RTNL_FAMILY_IPMR;
2430 	if (nla_put_u8(skb, IPMRA_CREPORT_MSGTYPE, msg->im_msgtype) ||
2431 	    nla_put_u32(skb, IPMRA_CREPORT_VIF_ID, msg->im_vif | (msg->im_vif_hi << 8)) ||
2432 	    nla_put_in_addr(skb, IPMRA_CREPORT_SRC_ADDR,
2433 			    msg->im_src.s_addr) ||
2434 	    nla_put_in_addr(skb, IPMRA_CREPORT_DST_ADDR,
2435 			    msg->im_dst.s_addr) ||
2436 	    nla_put_u32(skb, IPMRA_CREPORT_TABLE, mrt->id))
2437 		goto nla_put_failure;
2438 
2439 	nla = nla_reserve(skb, IPMRA_CREPORT_PKT, payloadlen);
2440 	if (!nla || skb_copy_bits(pkt, sizeof(struct igmpmsg),
2441 				  nla_data(nla), payloadlen))
2442 		goto nla_put_failure;
2443 
2444 	nlmsg_end(skb, nlh);
2445 
2446 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE_R, NULL, GFP_ATOMIC);
2447 	return;
2448 
2449 nla_put_failure:
2450 	nlmsg_cancel(skb, nlh);
2451 errout:
2452 	kfree_skb(skb);
2453 	rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE_R, -ENOBUFS);
2454 }
2455 
2456 static int ipmr_rtm_valid_getroute_req(struct sk_buff *skb,
2457 				       const struct nlmsghdr *nlh,
2458 				       struct nlattr **tb,
2459 				       struct netlink_ext_ack *extack)
2460 {
2461 	struct rtmsg *rtm;
2462 	int i, err;
2463 
2464 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2465 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for multicast route get request");
2466 		return -EINVAL;
2467 	}
2468 
2469 	if (!netlink_strict_get_check(skb))
2470 		return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
2471 					      rtm_ipv4_policy, extack);
2472 
2473 	rtm = nlmsg_data(nlh);
2474 	if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
2475 	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
2476 	    rtm->rtm_tos || rtm->rtm_table || rtm->rtm_protocol ||
2477 	    rtm->rtm_scope || rtm->rtm_type || rtm->rtm_flags) {
2478 		NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for multicast route get request");
2479 		return -EINVAL;
2480 	}
2481 
2482 	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2483 					    rtm_ipv4_policy, extack);
2484 	if (err)
2485 		return err;
2486 
2487 	if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
2488 	    (tb[RTA_DST] && !rtm->rtm_dst_len)) {
2489 		NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
2490 		return -EINVAL;
2491 	}
2492 
2493 	for (i = 0; i <= RTA_MAX; i++) {
2494 		if (!tb[i])
2495 			continue;
2496 
2497 		switch (i) {
2498 		case RTA_SRC:
2499 		case RTA_DST:
2500 		case RTA_TABLE:
2501 			break;
2502 		default:
2503 			NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in multicast route get request");
2504 			return -EINVAL;
2505 		}
2506 	}
2507 
2508 	return 0;
2509 }
2510 
2511 static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2512 			     struct netlink_ext_ack *extack)
2513 {
2514 	struct net *net = sock_net(in_skb->sk);
2515 	struct nlattr *tb[RTA_MAX + 1];
2516 	struct sk_buff *skb = NULL;
2517 	struct mfc_cache *cache;
2518 	struct mr_table *mrt;
2519 	__be32 src, grp;
2520 	u32 tableid;
2521 	int err;
2522 
2523 	err = ipmr_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
2524 	if (err < 0)
2525 		goto errout;
2526 
2527 	src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2528 	grp = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2529 	tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0;
2530 
2531 	mrt = ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT);
2532 	if (!mrt) {
2533 		err = -ENOENT;
2534 		goto errout_free;
2535 	}
2536 
2537 	/* entries are added/deleted only under RTNL */
2538 	rcu_read_lock();
2539 	cache = ipmr_cache_find(mrt, src, grp);
2540 	rcu_read_unlock();
2541 	if (!cache) {
2542 		err = -ENOENT;
2543 		goto errout_free;
2544 	}
2545 
2546 	skb = nlmsg_new(mroute_msgsize(false, mrt->maxvif), GFP_KERNEL);
2547 	if (!skb) {
2548 		err = -ENOBUFS;
2549 		goto errout_free;
2550 	}
2551 
2552 	err = ipmr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid,
2553 			       nlh->nlmsg_seq, cache,
2554 			       RTM_NEWROUTE, 0);
2555 	if (err < 0)
2556 		goto errout_free;
2557 
2558 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2559 
2560 errout:
2561 	return err;
2562 
2563 errout_free:
2564 	kfree_skb(skb);
2565 	goto errout;
2566 }
2567 
2568 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2569 {
2570 	struct fib_dump_filter filter = {};
2571 	int err;
2572 
2573 	if (cb->strict_check) {
2574 		err = ip_valid_fib_dump_req(sock_net(skb->sk), cb->nlh,
2575 					    &filter, cb);
2576 		if (err < 0)
2577 			return err;
2578 	}
2579 
2580 	if (filter.table_id) {
2581 		struct mr_table *mrt;
2582 
2583 		mrt = ipmr_get_table(sock_net(skb->sk), filter.table_id);
2584 		if (!mrt) {
2585 			if (rtnl_msg_family(cb->nlh) != RTNL_FAMILY_IPMR)
2586 				return skb->len;
2587 
2588 			NL_SET_ERR_MSG(cb->extack, "ipv4: MR table does not exist");
2589 			return -ENOENT;
2590 		}
2591 		err = mr_table_dump(mrt, skb, cb, _ipmr_fill_mroute,
2592 				    &mfc_unres_lock, &filter);
2593 		return skb->len ? : err;
2594 	}
2595 
2596 	return mr_rtm_dumproute(skb, cb, ipmr_mr_table_iter,
2597 				_ipmr_fill_mroute, &mfc_unres_lock, &filter);
2598 }
2599 
2600 static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {
2601 	[RTA_SRC]	= { .type = NLA_U32 },
2602 	[RTA_DST]	= { .type = NLA_U32 },
2603 	[RTA_IIF]	= { .type = NLA_U32 },
2604 	[RTA_TABLE]	= { .type = NLA_U32 },
2605 	[RTA_MULTIPATH]	= { .len = sizeof(struct rtnexthop) },
2606 };
2607 
2608 static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol)
2609 {
2610 	switch (rtm_protocol) {
2611 	case RTPROT_STATIC:
2612 	case RTPROT_MROUTED:
2613 		return true;
2614 	}
2615 	return false;
2616 }
2617 
2618 static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc)
2619 {
2620 	struct rtnexthop *rtnh = nla_data(nla);
2621 	int remaining = nla_len(nla), vifi = 0;
2622 
2623 	while (rtnh_ok(rtnh, remaining)) {
2624 		mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops;
2625 		if (++vifi == MAXVIFS)
2626 			break;
2627 		rtnh = rtnh_next(rtnh, &remaining);
2628 	}
2629 
2630 	return remaining > 0 ? -EINVAL : vifi;
2631 }
2632 
2633 /* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */
2634 static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
2635 			    struct mfcctl *mfcc, int *mrtsock,
2636 			    struct mr_table **mrtret,
2637 			    struct netlink_ext_ack *extack)
2638 {
2639 	struct net_device *dev = NULL;
2640 	u32 tblid = RT_TABLE_DEFAULT;
2641 	struct mr_table *mrt;
2642 	struct nlattr *attr;
2643 	struct rtmsg *rtm;
2644 	int ret, rem;
2645 
2646 	ret = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
2647 					rtm_ipmr_policy, extack);
2648 	if (ret < 0)
2649 		goto out;
2650 	rtm = nlmsg_data(nlh);
2651 
2652 	ret = -EINVAL;
2653 	if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 ||
2654 	    rtm->rtm_type != RTN_MULTICAST ||
2655 	    rtm->rtm_scope != RT_SCOPE_UNIVERSE ||
2656 	    !ipmr_rtm_validate_proto(rtm->rtm_protocol))
2657 		goto out;
2658 
2659 	memset(mfcc, 0, sizeof(*mfcc));
2660 	mfcc->mfcc_parent = -1;
2661 	ret = 0;
2662 	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) {
2663 		switch (nla_type(attr)) {
2664 		case RTA_SRC:
2665 			mfcc->mfcc_origin.s_addr = nla_get_be32(attr);
2666 			break;
2667 		case RTA_DST:
2668 			mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr);
2669 			break;
2670 		case RTA_IIF:
2671 			dev = __dev_get_by_index(net, nla_get_u32(attr));
2672 			if (!dev) {
2673 				ret = -ENODEV;
2674 				goto out;
2675 			}
2676 			break;
2677 		case RTA_MULTIPATH:
2678 			if (ipmr_nla_get_ttls(attr, mfcc) < 0) {
2679 				ret = -EINVAL;
2680 				goto out;
2681 			}
2682 			break;
2683 		case RTA_PREFSRC:
2684 			ret = 1;
2685 			break;
2686 		case RTA_TABLE:
2687 			tblid = nla_get_u32(attr);
2688 			break;
2689 		}
2690 	}
2691 	mrt = ipmr_get_table(net, tblid);
2692 	if (!mrt) {
2693 		ret = -ENOENT;
2694 		goto out;
2695 	}
2696 	*mrtret = mrt;
2697 	*mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0;
2698 	if (dev)
2699 		mfcc->mfcc_parent = ipmr_find_vif(mrt, dev);
2700 
2701 out:
2702 	return ret;
2703 }
2704 
2705 /* takes care of both newroute and delroute */
2706 static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh,
2707 			  struct netlink_ext_ack *extack)
2708 {
2709 	struct net *net = sock_net(skb->sk);
2710 	int ret, mrtsock, parent;
2711 	struct mr_table *tbl;
2712 	struct mfcctl mfcc;
2713 
2714 	mrtsock = 0;
2715 	tbl = NULL;
2716 	ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl, extack);
2717 	if (ret < 0)
2718 		return ret;
2719 
2720 	parent = ret ? mfcc.mfcc_parent : -1;
2721 	if (nlh->nlmsg_type == RTM_NEWROUTE)
2722 		return ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent);
2723 	else
2724 		return ipmr_mfc_delete(tbl, &mfcc, parent);
2725 }
2726 
2727 static bool ipmr_fill_table(struct mr_table *mrt, struct sk_buff *skb)
2728 {
2729 	u32 queue_len = atomic_read(&mrt->cache_resolve_queue_len);
2730 
2731 	if (nla_put_u32(skb, IPMRA_TABLE_ID, mrt->id) ||
2732 	    nla_put_u32(skb, IPMRA_TABLE_CACHE_RES_QUEUE_LEN, queue_len) ||
2733 	    nla_put_s32(skb, IPMRA_TABLE_MROUTE_REG_VIF_NUM,
2734 			mrt->mroute_reg_vif_num) ||
2735 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_ASSERT,
2736 		       mrt->mroute_do_assert) ||
2737 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_PIM, mrt->mroute_do_pim) ||
2738 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_WRVIFWHOLE,
2739 		       mrt->mroute_do_wrvifwhole))
2740 		return false;
2741 
2742 	return true;
2743 }
2744 
2745 static bool ipmr_fill_vif(struct mr_table *mrt, u32 vifid, struct sk_buff *skb)
2746 {
2747 	struct nlattr *vif_nest;
2748 	struct vif_device *vif;
2749 
2750 	/* if the VIF doesn't exist just continue */
2751 	if (!VIF_EXISTS(mrt, vifid))
2752 		return true;
2753 
2754 	vif = &mrt->vif_table[vifid];
2755 	vif_nest = nla_nest_start_noflag(skb, IPMRA_VIF);
2756 	if (!vif_nest)
2757 		return false;
2758 	if (nla_put_u32(skb, IPMRA_VIFA_IFINDEX, vif->dev->ifindex) ||
2759 	    nla_put_u32(skb, IPMRA_VIFA_VIF_ID, vifid) ||
2760 	    nla_put_u16(skb, IPMRA_VIFA_FLAGS, vif->flags) ||
2761 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_IN, vif->bytes_in,
2762 			      IPMRA_VIFA_PAD) ||
2763 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_OUT, vif->bytes_out,
2764 			      IPMRA_VIFA_PAD) ||
2765 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_IN, vif->pkt_in,
2766 			      IPMRA_VIFA_PAD) ||
2767 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_OUT, vif->pkt_out,
2768 			      IPMRA_VIFA_PAD) ||
2769 	    nla_put_be32(skb, IPMRA_VIFA_LOCAL_ADDR, vif->local) ||
2770 	    nla_put_be32(skb, IPMRA_VIFA_REMOTE_ADDR, vif->remote)) {
2771 		nla_nest_cancel(skb, vif_nest);
2772 		return false;
2773 	}
2774 	nla_nest_end(skb, vif_nest);
2775 
2776 	return true;
2777 }
2778 
2779 static int ipmr_valid_dumplink(const struct nlmsghdr *nlh,
2780 			       struct netlink_ext_ack *extack)
2781 {
2782 	struct ifinfomsg *ifm;
2783 
2784 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) {
2785 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for ipmr link dump");
2786 		return -EINVAL;
2787 	}
2788 
2789 	if (nlmsg_attrlen(nlh, sizeof(*ifm))) {
2790 		NL_SET_ERR_MSG(extack, "Invalid data after header in ipmr link dump");
2791 		return -EINVAL;
2792 	}
2793 
2794 	ifm = nlmsg_data(nlh);
2795 	if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags ||
2796 	    ifm->ifi_change || ifm->ifi_index) {
2797 		NL_SET_ERR_MSG(extack, "Invalid values in header for ipmr link dump request");
2798 		return -EINVAL;
2799 	}
2800 
2801 	return 0;
2802 }
2803 
2804 static int ipmr_rtm_dumplink(struct sk_buff *skb, struct netlink_callback *cb)
2805 {
2806 	struct net *net = sock_net(skb->sk);
2807 	struct nlmsghdr *nlh = NULL;
2808 	unsigned int t = 0, s_t;
2809 	unsigned int e = 0, s_e;
2810 	struct mr_table *mrt;
2811 
2812 	if (cb->strict_check) {
2813 		int err = ipmr_valid_dumplink(cb->nlh, cb->extack);
2814 
2815 		if (err < 0)
2816 			return err;
2817 	}
2818 
2819 	s_t = cb->args[0];
2820 	s_e = cb->args[1];
2821 
2822 	ipmr_for_each_table(mrt, net) {
2823 		struct nlattr *vifs, *af;
2824 		struct ifinfomsg *hdr;
2825 		u32 i;
2826 
2827 		if (t < s_t)
2828 			goto skip_table;
2829 		nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
2830 				cb->nlh->nlmsg_seq, RTM_NEWLINK,
2831 				sizeof(*hdr), NLM_F_MULTI);
2832 		if (!nlh)
2833 			break;
2834 
2835 		hdr = nlmsg_data(nlh);
2836 		memset(hdr, 0, sizeof(*hdr));
2837 		hdr->ifi_family = RTNL_FAMILY_IPMR;
2838 
2839 		af = nla_nest_start_noflag(skb, IFLA_AF_SPEC);
2840 		if (!af) {
2841 			nlmsg_cancel(skb, nlh);
2842 			goto out;
2843 		}
2844 
2845 		if (!ipmr_fill_table(mrt, skb)) {
2846 			nlmsg_cancel(skb, nlh);
2847 			goto out;
2848 		}
2849 
2850 		vifs = nla_nest_start_noflag(skb, IPMRA_TABLE_VIFS);
2851 		if (!vifs) {
2852 			nla_nest_end(skb, af);
2853 			nlmsg_end(skb, nlh);
2854 			goto out;
2855 		}
2856 		for (i = 0; i < mrt->maxvif; i++) {
2857 			if (e < s_e)
2858 				goto skip_entry;
2859 			if (!ipmr_fill_vif(mrt, i, skb)) {
2860 				nla_nest_end(skb, vifs);
2861 				nla_nest_end(skb, af);
2862 				nlmsg_end(skb, nlh);
2863 				goto out;
2864 			}
2865 skip_entry:
2866 			e++;
2867 		}
2868 		s_e = 0;
2869 		e = 0;
2870 		nla_nest_end(skb, vifs);
2871 		nla_nest_end(skb, af);
2872 		nlmsg_end(skb, nlh);
2873 skip_table:
2874 		t++;
2875 	}
2876 
2877 out:
2878 	cb->args[1] = e;
2879 	cb->args[0] = t;
2880 
2881 	return skb->len;
2882 }
2883 
2884 #ifdef CONFIG_PROC_FS
2885 /* The /proc interfaces to multicast routing :
2886  * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2887  */
2888 
2889 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2890 	__acquires(mrt_lock)
2891 {
2892 	struct mr_vif_iter *iter = seq->private;
2893 	struct net *net = seq_file_net(seq);
2894 	struct mr_table *mrt;
2895 
2896 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2897 	if (!mrt)
2898 		return ERR_PTR(-ENOENT);
2899 
2900 	iter->mrt = mrt;
2901 
2902 	read_lock(&mrt_lock);
2903 	return mr_vif_seq_start(seq, pos);
2904 }
2905 
2906 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2907 	__releases(mrt_lock)
2908 {
2909 	read_unlock(&mrt_lock);
2910 }
2911 
2912 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2913 {
2914 	struct mr_vif_iter *iter = seq->private;
2915 	struct mr_table *mrt = iter->mrt;
2916 
2917 	if (v == SEQ_START_TOKEN) {
2918 		seq_puts(seq,
2919 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2920 	} else {
2921 		const struct vif_device *vif = v;
2922 		const char *name =  vif->dev ?
2923 				    vif->dev->name : "none";
2924 
2925 		seq_printf(seq,
2926 			   "%2td %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2927 			   vif - mrt->vif_table,
2928 			   name, vif->bytes_in, vif->pkt_in,
2929 			   vif->bytes_out, vif->pkt_out,
2930 			   vif->flags, vif->local, vif->remote);
2931 	}
2932 	return 0;
2933 }
2934 
2935 static const struct seq_operations ipmr_vif_seq_ops = {
2936 	.start = ipmr_vif_seq_start,
2937 	.next  = mr_vif_seq_next,
2938 	.stop  = ipmr_vif_seq_stop,
2939 	.show  = ipmr_vif_seq_show,
2940 };
2941 
2942 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2943 {
2944 	struct net *net = seq_file_net(seq);
2945 	struct mr_table *mrt;
2946 
2947 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2948 	if (!mrt)
2949 		return ERR_PTR(-ENOENT);
2950 
2951 	return mr_mfc_seq_start(seq, pos, mrt, &mfc_unres_lock);
2952 }
2953 
2954 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2955 {
2956 	int n;
2957 
2958 	if (v == SEQ_START_TOKEN) {
2959 		seq_puts(seq,
2960 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2961 	} else {
2962 		const struct mfc_cache *mfc = v;
2963 		const struct mr_mfc_iter *it = seq->private;
2964 		const struct mr_table *mrt = it->mrt;
2965 
2966 		seq_printf(seq, "%08X %08X %-3hd",
2967 			   (__force u32) mfc->mfc_mcastgrp,
2968 			   (__force u32) mfc->mfc_origin,
2969 			   mfc->_c.mfc_parent);
2970 
2971 		if (it->cache != &mrt->mfc_unres_queue) {
2972 			seq_printf(seq, " %8lu %8lu %8lu",
2973 				   mfc->_c.mfc_un.res.pkt,
2974 				   mfc->_c.mfc_un.res.bytes,
2975 				   mfc->_c.mfc_un.res.wrong_if);
2976 			for (n = mfc->_c.mfc_un.res.minvif;
2977 			     n < mfc->_c.mfc_un.res.maxvif; n++) {
2978 				if (VIF_EXISTS(mrt, n) &&
2979 				    mfc->_c.mfc_un.res.ttls[n] < 255)
2980 					seq_printf(seq,
2981 					   " %2d:%-3d",
2982 					   n, mfc->_c.mfc_un.res.ttls[n]);
2983 			}
2984 		} else {
2985 			/* unresolved mfc_caches don't contain
2986 			 * pkt, bytes and wrong_if values
2987 			 */
2988 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
2989 		}
2990 		seq_putc(seq, '\n');
2991 	}
2992 	return 0;
2993 }
2994 
2995 static const struct seq_operations ipmr_mfc_seq_ops = {
2996 	.start = ipmr_mfc_seq_start,
2997 	.next  = mr_mfc_seq_next,
2998 	.stop  = mr_mfc_seq_stop,
2999 	.show  = ipmr_mfc_seq_show,
3000 };
3001 #endif
3002 
3003 #ifdef CONFIG_IP_PIMSM_V2
3004 static const struct net_protocol pim_protocol = {
3005 	.handler	=	pim_rcv,
3006 };
3007 #endif
3008 
3009 static unsigned int ipmr_seq_read(struct net *net)
3010 {
3011 	ASSERT_RTNL();
3012 
3013 	return net->ipv4.ipmr_seq + ipmr_rules_seq_read(net);
3014 }
3015 
3016 static int ipmr_dump(struct net *net, struct notifier_block *nb,
3017 		     struct netlink_ext_ack *extack)
3018 {
3019 	return mr_dump(net, nb, RTNL_FAMILY_IPMR, ipmr_rules_dump,
3020 		       ipmr_mr_table_iter, &mrt_lock, extack);
3021 }
3022 
3023 static const struct fib_notifier_ops ipmr_notifier_ops_template = {
3024 	.family		= RTNL_FAMILY_IPMR,
3025 	.fib_seq_read	= ipmr_seq_read,
3026 	.fib_dump	= ipmr_dump,
3027 	.owner		= THIS_MODULE,
3028 };
3029 
3030 static int __net_init ipmr_notifier_init(struct net *net)
3031 {
3032 	struct fib_notifier_ops *ops;
3033 
3034 	net->ipv4.ipmr_seq = 0;
3035 
3036 	ops = fib_notifier_ops_register(&ipmr_notifier_ops_template, net);
3037 	if (IS_ERR(ops))
3038 		return PTR_ERR(ops);
3039 	net->ipv4.ipmr_notifier_ops = ops;
3040 
3041 	return 0;
3042 }
3043 
3044 static void __net_exit ipmr_notifier_exit(struct net *net)
3045 {
3046 	fib_notifier_ops_unregister(net->ipv4.ipmr_notifier_ops);
3047 	net->ipv4.ipmr_notifier_ops = NULL;
3048 }
3049 
3050 /* Setup for IP multicast routing */
3051 static int __net_init ipmr_net_init(struct net *net)
3052 {
3053 	int err;
3054 
3055 	err = ipmr_notifier_init(net);
3056 	if (err)
3057 		goto ipmr_notifier_fail;
3058 
3059 	err = ipmr_rules_init(net);
3060 	if (err < 0)
3061 		goto ipmr_rules_fail;
3062 
3063 #ifdef CONFIG_PROC_FS
3064 	err = -ENOMEM;
3065 	if (!proc_create_net("ip_mr_vif", 0, net->proc_net, &ipmr_vif_seq_ops,
3066 			sizeof(struct mr_vif_iter)))
3067 		goto proc_vif_fail;
3068 	if (!proc_create_net("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_seq_ops,
3069 			sizeof(struct mr_mfc_iter)))
3070 		goto proc_cache_fail;
3071 #endif
3072 	return 0;
3073 
3074 #ifdef CONFIG_PROC_FS
3075 proc_cache_fail:
3076 	remove_proc_entry("ip_mr_vif", net->proc_net);
3077 proc_vif_fail:
3078 	rtnl_lock();
3079 	ipmr_rules_exit(net);
3080 	rtnl_unlock();
3081 #endif
3082 ipmr_rules_fail:
3083 	ipmr_notifier_exit(net);
3084 ipmr_notifier_fail:
3085 	return err;
3086 }
3087 
3088 static void __net_exit ipmr_net_exit(struct net *net)
3089 {
3090 #ifdef CONFIG_PROC_FS
3091 	remove_proc_entry("ip_mr_cache", net->proc_net);
3092 	remove_proc_entry("ip_mr_vif", net->proc_net);
3093 #endif
3094 	ipmr_notifier_exit(net);
3095 }
3096 
3097 static void __net_exit ipmr_net_exit_batch(struct list_head *net_list)
3098 {
3099 	struct net *net;
3100 
3101 	rtnl_lock();
3102 	list_for_each_entry(net, net_list, exit_list)
3103 		ipmr_rules_exit(net);
3104 	rtnl_unlock();
3105 }
3106 
3107 static struct pernet_operations ipmr_net_ops = {
3108 	.init = ipmr_net_init,
3109 	.exit = ipmr_net_exit,
3110 	.exit_batch = ipmr_net_exit_batch,
3111 };
3112 
3113 int __init ip_mr_init(void)
3114 {
3115 	int err;
3116 
3117 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
3118 				       sizeof(struct mfc_cache),
3119 				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
3120 				       NULL);
3121 
3122 	err = register_pernet_subsys(&ipmr_net_ops);
3123 	if (err)
3124 		goto reg_pernet_fail;
3125 
3126 	err = register_netdevice_notifier(&ip_mr_notifier);
3127 	if (err)
3128 		goto reg_notif_fail;
3129 #ifdef CONFIG_IP_PIMSM_V2
3130 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
3131 		pr_err("%s: can't add PIM protocol\n", __func__);
3132 		err = -EAGAIN;
3133 		goto add_proto_fail;
3134 	}
3135 #endif
3136 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
3137 		      ipmr_rtm_getroute, ipmr_rtm_dumproute, 0);
3138 	rtnl_register(RTNL_FAMILY_IPMR, RTM_NEWROUTE,
3139 		      ipmr_rtm_route, NULL, 0);
3140 	rtnl_register(RTNL_FAMILY_IPMR, RTM_DELROUTE,
3141 		      ipmr_rtm_route, NULL, 0);
3142 
3143 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETLINK,
3144 		      NULL, ipmr_rtm_dumplink, 0);
3145 	return 0;
3146 
3147 #ifdef CONFIG_IP_PIMSM_V2
3148 add_proto_fail:
3149 	unregister_netdevice_notifier(&ip_mr_notifier);
3150 #endif
3151 reg_notif_fail:
3152 	unregister_pernet_subsys(&ipmr_net_ops);
3153 reg_pernet_fail:
3154 	kmem_cache_destroy(mrt_cachep);
3155 	return err;
3156 }
3157