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 #include <net/inet_dscp.h>
66 
67 #include <linux/nospec.h>
68 
69 struct ipmr_rule {
70 	struct fib_rule		common;
71 };
72 
73 struct ipmr_result {
74 	struct mr_table		*mrt;
75 };
76 
77 /* Big lock, protecting vif table, mrt cache and mroute socket state.
78  * Note that the changes are semaphored via rtnl_lock.
79  */
80 
81 static DEFINE_SPINLOCK(mrt_lock);
82 
83 static struct net_device *vif_dev_read(const struct vif_device *vif)
84 {
85 	return rcu_dereference(vif->dev);
86 }
87 
88 /* Multicast router control variables */
89 
90 /* Special spinlock for queue of unresolved entries */
91 static DEFINE_SPINLOCK(mfc_unres_lock);
92 
93 /* We return to original Alan's scheme. Hash table of resolved
94  * entries is changed only in process context and protected
95  * with weak lock mrt_lock. Queue of unresolved entries is protected
96  * with strong spinlock mfc_unres_lock.
97  *
98  * In this case data path is free of exclusive locks at all.
99  */
100 
101 static struct kmem_cache *mrt_cachep __ro_after_init;
102 
103 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
104 static void ipmr_free_table(struct mr_table *mrt);
105 
106 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
107 			  struct net_device *dev, struct sk_buff *skb,
108 			  struct mfc_cache *cache, int local);
109 static int ipmr_cache_report(const struct mr_table *mrt,
110 			     struct sk_buff *pkt, vifi_t vifi, int assert);
111 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
112 				 int cmd);
113 static void igmpmsg_netlink_event(const struct mr_table *mrt, struct sk_buff *pkt);
114 static void mroute_clean_tables(struct mr_table *mrt, int flags);
115 static void ipmr_expire_process(struct timer_list *t);
116 
117 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
118 #define ipmr_for_each_table(mrt, net)					\
119 	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list,	\
120 				lockdep_rtnl_is_held() ||		\
121 				list_empty(&net->ipv4.mr_tables))
122 
123 static struct mr_table *ipmr_mr_table_iter(struct net *net,
124 					   struct mr_table *mrt)
125 {
126 	struct mr_table *ret;
127 
128 	if (!mrt)
129 		ret = list_entry_rcu(net->ipv4.mr_tables.next,
130 				     struct mr_table, list);
131 	else
132 		ret = list_entry_rcu(mrt->list.next,
133 				     struct mr_table, list);
134 
135 	if (&ret->list == &net->ipv4.mr_tables)
136 		return NULL;
137 	return ret;
138 }
139 
140 static struct mr_table *__ipmr_get_table(struct net *net, u32 id)
141 {
142 	struct mr_table *mrt;
143 
144 	ipmr_for_each_table(mrt, net) {
145 		if (mrt->id == id)
146 			return mrt;
147 	}
148 	return NULL;
149 }
150 
151 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
152 {
153 	struct mr_table *mrt;
154 
155 	rcu_read_lock();
156 	mrt = __ipmr_get_table(net, id);
157 	rcu_read_unlock();
158 	return mrt;
159 }
160 
161 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
162 			   struct mr_table **mrt)
163 {
164 	int err;
165 	struct ipmr_result res;
166 	struct fib_lookup_arg arg = {
167 		.result = &res,
168 		.flags = FIB_LOOKUP_NOREF,
169 	};
170 
171 	/* update flow if oif or iif point to device enslaved to l3mdev */
172 	l3mdev_update_flow(net, flowi4_to_flowi(flp4));
173 
174 	err = fib_rules_lookup(net->ipv4.mr_rules_ops,
175 			       flowi4_to_flowi(flp4), 0, &arg);
176 	if (err < 0)
177 		return err;
178 	*mrt = res.mrt;
179 	return 0;
180 }
181 
182 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
183 			    int flags, struct fib_lookup_arg *arg)
184 {
185 	struct ipmr_result *res = arg->result;
186 	struct mr_table *mrt;
187 
188 	switch (rule->action) {
189 	case FR_ACT_TO_TBL:
190 		break;
191 	case FR_ACT_UNREACHABLE:
192 		return -ENETUNREACH;
193 	case FR_ACT_PROHIBIT:
194 		return -EACCES;
195 	case FR_ACT_BLACKHOLE:
196 	default:
197 		return -EINVAL;
198 	}
199 
200 	arg->table = fib_rule_get_table(rule, arg);
201 
202 	mrt = __ipmr_get_table(rule->fr_net, arg->table);
203 	if (!mrt)
204 		return -EAGAIN;
205 	res->mrt = mrt;
206 	return 0;
207 }
208 
209 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
210 {
211 	return 1;
212 }
213 
214 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
215 			       struct fib_rule_hdr *frh, struct nlattr **tb,
216 			       struct netlink_ext_ack *extack)
217 {
218 	return 0;
219 }
220 
221 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
222 			     struct nlattr **tb)
223 {
224 	return 1;
225 }
226 
227 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
228 			  struct fib_rule_hdr *frh)
229 {
230 	frh->dst_len = 0;
231 	frh->src_len = 0;
232 	frh->tos     = 0;
233 	return 0;
234 }
235 
236 static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
237 	.family		= RTNL_FAMILY_IPMR,
238 	.rule_size	= sizeof(struct ipmr_rule),
239 	.addr_size	= sizeof(u32),
240 	.action		= ipmr_rule_action,
241 	.match		= ipmr_rule_match,
242 	.configure	= ipmr_rule_configure,
243 	.compare	= ipmr_rule_compare,
244 	.fill		= ipmr_rule_fill,
245 	.nlgroup	= RTNLGRP_IPV4_RULE,
246 	.owner		= THIS_MODULE,
247 };
248 
249 static int __net_init ipmr_rules_init(struct net *net)
250 {
251 	struct fib_rules_ops *ops;
252 	struct mr_table *mrt;
253 	int err;
254 
255 	ops = fib_rules_register(&ipmr_rules_ops_template, net);
256 	if (IS_ERR(ops))
257 		return PTR_ERR(ops);
258 
259 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
260 
261 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
262 	if (IS_ERR(mrt)) {
263 		err = PTR_ERR(mrt);
264 		goto err1;
265 	}
266 
267 	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT);
268 	if (err < 0)
269 		goto err2;
270 
271 	net->ipv4.mr_rules_ops = ops;
272 	return 0;
273 
274 err2:
275 	rtnl_lock();
276 	ipmr_free_table(mrt);
277 	rtnl_unlock();
278 err1:
279 	fib_rules_unregister(ops);
280 	return err;
281 }
282 
283 static void __net_exit ipmr_rules_exit(struct net *net)
284 {
285 	struct mr_table *mrt, *next;
286 
287 	ASSERT_RTNL();
288 	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
289 		list_del(&mrt->list);
290 		ipmr_free_table(mrt);
291 	}
292 	fib_rules_unregister(net->ipv4.mr_rules_ops);
293 }
294 
295 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
296 			   struct netlink_ext_ack *extack)
297 {
298 	return fib_rules_dump(net, nb, RTNL_FAMILY_IPMR, extack);
299 }
300 
301 static unsigned int ipmr_rules_seq_read(const struct net *net)
302 {
303 	return fib_rules_seq_read(net, RTNL_FAMILY_IPMR);
304 }
305 
306 bool ipmr_rule_default(const struct fib_rule *rule)
307 {
308 	return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
309 }
310 EXPORT_SYMBOL(ipmr_rule_default);
311 #else
312 #define ipmr_for_each_table(mrt, net) \
313 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
314 
315 static struct mr_table *ipmr_mr_table_iter(struct net *net,
316 					   struct mr_table *mrt)
317 {
318 	if (!mrt)
319 		return net->ipv4.mrt;
320 	return NULL;
321 }
322 
323 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
324 {
325 	return net->ipv4.mrt;
326 }
327 
328 #define __ipmr_get_table ipmr_get_table
329 
330 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
331 			   struct mr_table **mrt)
332 {
333 	*mrt = net->ipv4.mrt;
334 	return 0;
335 }
336 
337 static int __net_init ipmr_rules_init(struct net *net)
338 {
339 	struct mr_table *mrt;
340 
341 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
342 	if (IS_ERR(mrt))
343 		return PTR_ERR(mrt);
344 	net->ipv4.mrt = mrt;
345 	return 0;
346 }
347 
348 static void __net_exit ipmr_rules_exit(struct net *net)
349 {
350 	ASSERT_RTNL();
351 	ipmr_free_table(net->ipv4.mrt);
352 	net->ipv4.mrt = NULL;
353 }
354 
355 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
356 			   struct netlink_ext_ack *extack)
357 {
358 	return 0;
359 }
360 
361 static unsigned int ipmr_rules_seq_read(const struct net *net)
362 {
363 	return 0;
364 }
365 
366 bool ipmr_rule_default(const struct fib_rule *rule)
367 {
368 	return true;
369 }
370 EXPORT_SYMBOL(ipmr_rule_default);
371 #endif
372 
373 static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
374 				const void *ptr)
375 {
376 	const struct mfc_cache_cmp_arg *cmparg = arg->key;
377 	const struct mfc_cache *c = ptr;
378 
379 	return cmparg->mfc_mcastgrp != c->mfc_mcastgrp ||
380 	       cmparg->mfc_origin != c->mfc_origin;
381 }
382 
383 static const struct rhashtable_params ipmr_rht_params = {
384 	.head_offset = offsetof(struct mr_mfc, mnode),
385 	.key_offset = offsetof(struct mfc_cache, cmparg),
386 	.key_len = sizeof(struct mfc_cache_cmp_arg),
387 	.nelem_hint = 3,
388 	.obj_cmpfn = ipmr_hash_cmp,
389 	.automatic_shrinking = true,
390 };
391 
392 static void ipmr_new_table_set(struct mr_table *mrt,
393 			       struct net *net)
394 {
395 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
396 	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
397 #endif
398 }
399 
400 static struct mfc_cache_cmp_arg ipmr_mr_table_ops_cmparg_any = {
401 	.mfc_mcastgrp = htonl(INADDR_ANY),
402 	.mfc_origin = htonl(INADDR_ANY),
403 };
404 
405 static struct mr_table_ops ipmr_mr_table_ops = {
406 	.rht_params = &ipmr_rht_params,
407 	.cmparg_any = &ipmr_mr_table_ops_cmparg_any,
408 };
409 
410 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
411 {
412 	struct mr_table *mrt;
413 
414 	/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
415 	if (id != RT_TABLE_DEFAULT && id >= 1000000000)
416 		return ERR_PTR(-EINVAL);
417 
418 	mrt = __ipmr_get_table(net, id);
419 	if (mrt)
420 		return mrt;
421 
422 	return mr_table_alloc(net, id, &ipmr_mr_table_ops,
423 			      ipmr_expire_process, ipmr_new_table_set);
424 }
425 
426 static void ipmr_free_table(struct mr_table *mrt)
427 {
428 	struct net *net = read_pnet(&mrt->net);
429 
430 	WARN_ON_ONCE(!mr_can_free_table(net));
431 
432 	timer_shutdown_sync(&mrt->ipmr_expire_timer);
433 	mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC |
434 				 MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC);
435 	rhltable_destroy(&mrt->mfc_hash);
436 	kfree(mrt);
437 }
438 
439 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
440 
441 /* Initialize ipmr pimreg/tunnel in_device */
442 static bool ipmr_init_vif_indev(const struct net_device *dev)
443 {
444 	struct in_device *in_dev;
445 
446 	ASSERT_RTNL();
447 
448 	in_dev = __in_dev_get_rtnl(dev);
449 	if (!in_dev)
450 		return false;
451 	ipv4_devconf_setall(in_dev);
452 	neigh_parms_data_state_setall(in_dev->arp_parms);
453 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
454 
455 	return true;
456 }
457 
458 static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
459 {
460 	struct net_device *tunnel_dev, *new_dev;
461 	struct ip_tunnel_parm_kern p = { };
462 	int err;
463 
464 	tunnel_dev = __dev_get_by_name(net, "tunl0");
465 	if (!tunnel_dev)
466 		goto out;
467 
468 	p.iph.daddr = v->vifc_rmt_addr.s_addr;
469 	p.iph.saddr = v->vifc_lcl_addr.s_addr;
470 	p.iph.version = 4;
471 	p.iph.ihl = 5;
472 	p.iph.protocol = IPPROTO_IPIP;
473 	sprintf(p.name, "dvmrp%d", v->vifc_vifi);
474 
475 	if (!tunnel_dev->netdev_ops->ndo_tunnel_ctl)
476 		goto out;
477 	err = tunnel_dev->netdev_ops->ndo_tunnel_ctl(tunnel_dev, &p,
478 			SIOCADDTUNNEL);
479 	if (err)
480 		goto out;
481 
482 	new_dev = __dev_get_by_name(net, p.name);
483 	if (!new_dev)
484 		goto out;
485 
486 	new_dev->flags |= IFF_MULTICAST;
487 	if (!ipmr_init_vif_indev(new_dev))
488 		goto out_unregister;
489 	if (dev_open(new_dev, NULL))
490 		goto out_unregister;
491 	dev_hold(new_dev);
492 	err = dev_set_allmulti(new_dev, 1);
493 	if (err) {
494 		dev_close(new_dev);
495 		tunnel_dev->netdev_ops->ndo_tunnel_ctl(tunnel_dev, &p,
496 				SIOCDELTUNNEL);
497 		dev_put(new_dev);
498 		new_dev = ERR_PTR(err);
499 	}
500 	return new_dev;
501 
502 out_unregister:
503 	unregister_netdevice(new_dev);
504 out:
505 	return ERR_PTR(-ENOBUFS);
506 }
507 
508 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
509 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
510 {
511 	struct net *net = dev_net(dev);
512 	struct mr_table *mrt;
513 	struct flowi4 fl4 = {
514 		.flowi4_oif	= dev->ifindex,
515 		.flowi4_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
516 		.flowi4_mark	= skb->mark,
517 	};
518 	int err;
519 
520 	err = ipmr_fib_lookup(net, &fl4, &mrt);
521 	if (err < 0) {
522 		kfree_skb(skb);
523 		return err;
524 	}
525 
526 	DEV_STATS_ADD(dev, tx_bytes, skb->len);
527 	DEV_STATS_INC(dev, tx_packets);
528 	rcu_read_lock();
529 
530 	/* Pairs with WRITE_ONCE() in vif_add() and vif_delete() */
531 	ipmr_cache_report(mrt, skb, READ_ONCE(mrt->mroute_reg_vif_num),
532 			  IGMPMSG_WHOLEPKT);
533 
534 	rcu_read_unlock();
535 	kfree_skb(skb);
536 	return NETDEV_TX_OK;
537 }
538 
539 static int reg_vif_get_iflink(const struct net_device *dev)
540 {
541 	return 0;
542 }
543 
544 static const struct net_device_ops reg_vif_netdev_ops = {
545 	.ndo_start_xmit	= reg_vif_xmit,
546 	.ndo_get_iflink = reg_vif_get_iflink,
547 };
548 
549 static void reg_vif_setup(struct net_device *dev)
550 {
551 	dev->type		= ARPHRD_PIMREG;
552 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
553 	dev->flags		= IFF_NOARP;
554 	dev->netdev_ops		= &reg_vif_netdev_ops;
555 	dev->needs_free_netdev	= true;
556 	dev->netns_immutable	= true;
557 }
558 
559 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
560 {
561 	struct net_device *dev;
562 	char name[IFNAMSIZ];
563 
564 	if (mrt->id == RT_TABLE_DEFAULT)
565 		sprintf(name, "pimreg");
566 	else
567 		sprintf(name, "pimreg%u", mrt->id);
568 
569 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
570 
571 	if (!dev)
572 		return NULL;
573 
574 	dev_net_set(dev, net);
575 
576 	if (register_netdevice(dev)) {
577 		free_netdev(dev);
578 		return NULL;
579 	}
580 
581 	if (!ipmr_init_vif_indev(dev))
582 		goto failure;
583 	if (dev_open(dev, NULL))
584 		goto failure;
585 
586 	dev_hold(dev);
587 
588 	return dev;
589 
590 failure:
591 	unregister_netdevice(dev);
592 	return NULL;
593 }
594 
595 /* called with rcu_read_lock() */
596 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
597 		     unsigned int pimlen)
598 {
599 	struct net_device *reg_dev = NULL;
600 	struct iphdr *encap;
601 	int vif_num;
602 
603 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
604 	/* Check that:
605 	 * a. packet is really sent to a multicast group
606 	 * b. packet is not a NULL-REGISTER
607 	 * c. packet is not truncated
608 	 */
609 	if (!ipv4_is_multicast(encap->daddr) ||
610 	    encap->tot_len == 0 ||
611 	    ntohs(encap->tot_len) + pimlen > skb->len)
612 		return 1;
613 
614 	/* Pairs with WRITE_ONCE() in vif_add()/vid_delete() */
615 	vif_num = READ_ONCE(mrt->mroute_reg_vif_num);
616 	if (vif_num >= 0)
617 		reg_dev = vif_dev_read(&mrt->vif_table[vif_num]);
618 	if (!reg_dev)
619 		return 1;
620 
621 	skb->mac_header = skb->network_header;
622 	skb_pull(skb, (u8 *)encap - skb->data);
623 	skb_reset_network_header(skb);
624 	skb->protocol = htons(ETH_P_IP);
625 	skb->ip_summed = CHECKSUM_NONE;
626 
627 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
628 
629 	netif_rx(skb);
630 
631 	return NET_RX_SUCCESS;
632 }
633 #else
634 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
635 {
636 	return NULL;
637 }
638 #endif
639 
640 static int call_ipmr_vif_entry_notifiers(struct net *net,
641 					 enum fib_event_type event_type,
642 					 struct vif_device *vif,
643 					 struct net_device *vif_dev,
644 					 vifi_t vif_index, u32 tb_id)
645 {
646 	return mr_call_vif_notifiers(net, RTNL_FAMILY_IPMR, event_type,
647 				     vif, vif_dev, vif_index, tb_id,
648 				     &net->ipv4.ipmr_seq);
649 }
650 
651 static int call_ipmr_mfc_entry_notifiers(struct net *net,
652 					 enum fib_event_type event_type,
653 					 struct mfc_cache *mfc, u32 tb_id)
654 {
655 	return mr_call_mfc_notifiers(net, RTNL_FAMILY_IPMR, event_type,
656 				     &mfc->_c, tb_id, &net->ipv4.ipmr_seq);
657 }
658 
659 /**
660  *	vif_delete - Delete a VIF entry
661  *	@mrt: Table to delete from
662  *	@vifi: VIF identifier to delete
663  *	@notify: Set to 1, if the caller is a notifier_call
664  *	@head: if unregistering the VIF, place it on this queue
665  */
666 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
667 		      struct list_head *head)
668 {
669 	struct net *net = read_pnet(&mrt->net);
670 	struct vif_device *v;
671 	struct net_device *dev;
672 	struct in_device *in_dev;
673 
674 	if (vifi < 0 || vifi >= mrt->maxvif)
675 		return -EADDRNOTAVAIL;
676 
677 	v = &mrt->vif_table[vifi];
678 
679 	dev = rtnl_dereference(v->dev);
680 	if (!dev)
681 		return -EADDRNOTAVAIL;
682 
683 	spin_lock(&mrt_lock);
684 	call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_DEL, v, dev,
685 				      vifi, mrt->id);
686 	RCU_INIT_POINTER(v->dev, NULL);
687 
688 	if (vifi == mrt->mroute_reg_vif_num) {
689 		/* Pairs with READ_ONCE() in ipmr_cache_report() and reg_vif_xmit() */
690 		WRITE_ONCE(mrt->mroute_reg_vif_num, -1);
691 	}
692 	if (vifi + 1 == mrt->maxvif) {
693 		int tmp;
694 
695 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
696 			if (VIF_EXISTS(mrt, tmp))
697 				break;
698 		}
699 		WRITE_ONCE(mrt->maxvif, tmp + 1);
700 	}
701 
702 	spin_unlock(&mrt_lock);
703 
704 	dev_set_allmulti(dev, -1);
705 
706 	in_dev = __in_dev_get_rtnl(dev);
707 	if (in_dev) {
708 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
709 		inet_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
710 					    NETCONFA_MC_FORWARDING,
711 					    dev->ifindex, &in_dev->cnf);
712 		ip_rt_multicast_event(in_dev);
713 	}
714 
715 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
716 		unregister_netdevice_queue(dev, head);
717 
718 	netdev_put(dev, &v->dev_tracker);
719 	return 0;
720 }
721 
722 static void ipmr_cache_free_rcu(struct rcu_head *head)
723 {
724 	struct mr_mfc *c = container_of(head, struct mr_mfc, rcu);
725 
726 	kmem_cache_free(mrt_cachep, (struct mfc_cache *)c);
727 }
728 
729 static void ipmr_cache_free(struct mfc_cache *c)
730 {
731 	call_rcu(&c->_c.rcu, ipmr_cache_free_rcu);
732 }
733 
734 /* Destroy an unresolved cache entry, killing queued skbs
735  * and reporting error to netlink readers.
736  */
737 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
738 {
739 	struct net *net = read_pnet(&mrt->net);
740 	struct sk_buff *skb;
741 	struct nlmsgerr *e;
742 
743 	atomic_dec(&mrt->cache_resolve_queue_len);
744 
745 	while ((skb = skb_dequeue(&c->_c.mfc_un.unres.unresolved))) {
746 		if (ip_hdr(skb)->version == 0) {
747 			struct nlmsghdr *nlh = skb_pull(skb,
748 							sizeof(struct iphdr));
749 			nlh->nlmsg_type = NLMSG_ERROR;
750 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
751 			skb_trim(skb, nlh->nlmsg_len);
752 			e = nlmsg_data(nlh);
753 			e->error = -ETIMEDOUT;
754 			memset(&e->msg, 0, sizeof(e->msg));
755 
756 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
757 		} else {
758 			kfree_skb(skb);
759 		}
760 	}
761 
762 	ipmr_cache_free(c);
763 }
764 
765 /* Timer process for the unresolved queue. */
766 static void ipmr_expire_process(struct timer_list *t)
767 {
768 	struct mr_table *mrt = timer_container_of(mrt, t, ipmr_expire_timer);
769 	struct mr_mfc *c, *next;
770 	unsigned long expires;
771 	unsigned long now;
772 
773 	if (!spin_trylock(&mfc_unres_lock)) {
774 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
775 		return;
776 	}
777 
778 	if (list_empty(&mrt->mfc_unres_queue))
779 		goto out;
780 
781 	now = jiffies;
782 	expires = 10*HZ;
783 
784 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
785 		if (time_after(c->mfc_un.unres.expires, now)) {
786 			unsigned long interval = c->mfc_un.unres.expires - now;
787 			if (interval < expires)
788 				expires = interval;
789 			continue;
790 		}
791 
792 		list_del(&c->list);
793 		mroute_netlink_event(mrt, (struct mfc_cache *)c, RTM_DELROUTE);
794 		ipmr_destroy_unres(mrt, (struct mfc_cache *)c);
795 	}
796 
797 	if (!list_empty(&mrt->mfc_unres_queue))
798 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
799 
800 out:
801 	spin_unlock(&mfc_unres_lock);
802 }
803 
804 /* Fill oifs list. It is called under locked mrt_lock. */
805 static void ipmr_update_thresholds(struct mr_table *mrt, struct mr_mfc *cache,
806 				   unsigned char *ttls)
807 {
808 	int vifi;
809 
810 	cache->mfc_un.res.minvif = MAXVIFS;
811 	cache->mfc_un.res.maxvif = 0;
812 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
813 
814 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
815 		if (VIF_EXISTS(mrt, vifi) &&
816 		    ttls[vifi] && ttls[vifi] < 255) {
817 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
818 			if (cache->mfc_un.res.minvif > vifi)
819 				cache->mfc_un.res.minvif = vifi;
820 			if (cache->mfc_un.res.maxvif <= vifi)
821 				cache->mfc_un.res.maxvif = vifi + 1;
822 		}
823 	}
824 	WRITE_ONCE(cache->mfc_un.res.lastuse, jiffies);
825 }
826 
827 static int vif_add(struct net *net, struct mr_table *mrt,
828 		   struct vifctl *vifc, int mrtsock)
829 {
830 	struct netdev_phys_item_id ppid = { };
831 	int vifi = vifc->vifc_vifi;
832 	struct vif_device *v = &mrt->vif_table[vifi];
833 	struct net_device *dev;
834 	struct in_device *in_dev;
835 	int err;
836 
837 	/* Is vif busy ? */
838 	if (VIF_EXISTS(mrt, vifi))
839 		return -EADDRINUSE;
840 
841 	switch (vifc->vifc_flags) {
842 	case VIFF_REGISTER:
843 		if (!ipmr_pimsm_enabled())
844 			return -EINVAL;
845 		/* Special Purpose VIF in PIM
846 		 * All the packets will be sent to the daemon
847 		 */
848 		if (mrt->mroute_reg_vif_num >= 0)
849 			return -EADDRINUSE;
850 		dev = ipmr_reg_vif(net, mrt);
851 		if (!dev)
852 			return -ENOBUFS;
853 		err = dev_set_allmulti(dev, 1);
854 		if (err) {
855 			unregister_netdevice(dev);
856 			dev_put(dev);
857 			return err;
858 		}
859 		break;
860 	case VIFF_TUNNEL:
861 		dev = ipmr_new_tunnel(net, vifc);
862 		if (IS_ERR(dev))
863 			return PTR_ERR(dev);
864 		break;
865 	case VIFF_USE_IFINDEX:
866 	case 0:
867 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
868 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
869 			if (dev && !__in_dev_get_rtnl(dev)) {
870 				dev_put(dev);
871 				return -EADDRNOTAVAIL;
872 			}
873 		} else {
874 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
875 		}
876 		if (!dev)
877 			return -EADDRNOTAVAIL;
878 		err = dev_set_allmulti(dev, 1);
879 		if (err) {
880 			dev_put(dev);
881 			return err;
882 		}
883 		break;
884 	default:
885 		return -EINVAL;
886 	}
887 
888 	in_dev = __in_dev_get_rtnl(dev);
889 	if (!in_dev) {
890 		dev_put(dev);
891 		return -EADDRNOTAVAIL;
892 	}
893 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
894 	inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING,
895 				    dev->ifindex, &in_dev->cnf);
896 	ip_rt_multicast_event(in_dev);
897 
898 	/* Fill in the VIF structures */
899 	vif_device_init(v, dev, vifc->vifc_rate_limit,
900 			vifc->vifc_threshold,
901 			vifc->vifc_flags | (!mrtsock ? VIFF_STATIC : 0),
902 			(VIFF_TUNNEL | VIFF_REGISTER));
903 
904 	err = dev_get_port_parent_id(dev, &ppid, true);
905 	if (err == 0) {
906 		memcpy(v->dev_parent_id.id, ppid.id, ppid.id_len);
907 		v->dev_parent_id.id_len = ppid.id_len;
908 	} else {
909 		v->dev_parent_id.id_len = 0;
910 	}
911 
912 	v->local = vifc->vifc_lcl_addr.s_addr;
913 	v->remote = vifc->vifc_rmt_addr.s_addr;
914 
915 	/* And finish update writing critical data */
916 	spin_lock(&mrt_lock);
917 	rcu_assign_pointer(v->dev, dev);
918 	netdev_tracker_alloc(dev, &v->dev_tracker, GFP_ATOMIC);
919 	if (v->flags & VIFF_REGISTER) {
920 		/* Pairs with READ_ONCE() in ipmr_cache_report() and reg_vif_xmit() */
921 		WRITE_ONCE(mrt->mroute_reg_vif_num, vifi);
922 	}
923 	if (vifi+1 > mrt->maxvif)
924 		WRITE_ONCE(mrt->maxvif, vifi + 1);
925 	spin_unlock(&mrt_lock);
926 	call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD, v, dev,
927 				      vifi, mrt->id);
928 	return 0;
929 }
930 
931 /* called with rcu_read_lock() */
932 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
933 					 __be32 origin,
934 					 __be32 mcastgrp)
935 {
936 	struct mfc_cache_cmp_arg arg = {
937 			.mfc_mcastgrp = mcastgrp,
938 			.mfc_origin = origin
939 	};
940 
941 	return mr_mfc_find(mrt, &arg);
942 }
943 
944 /* Look for a (*,G) entry */
945 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
946 					     __be32 mcastgrp, int vifi)
947 {
948 	struct mfc_cache_cmp_arg arg = {
949 			.mfc_mcastgrp = mcastgrp,
950 			.mfc_origin = htonl(INADDR_ANY)
951 	};
952 
953 	if (mcastgrp == htonl(INADDR_ANY))
954 		return mr_mfc_find_any_parent(mrt, vifi);
955 	return mr_mfc_find_any(mrt, vifi, &arg);
956 }
957 
958 /* Look for a (S,G,iif) entry if parent != -1 */
959 static struct mfc_cache *ipmr_cache_find_parent(struct mr_table *mrt,
960 						__be32 origin, __be32 mcastgrp,
961 						int parent)
962 {
963 	struct mfc_cache_cmp_arg arg = {
964 			.mfc_mcastgrp = mcastgrp,
965 			.mfc_origin = origin,
966 	};
967 
968 	return mr_mfc_find_parent(mrt, &arg, parent);
969 }
970 
971 /* Allocate a multicast cache entry */
972 static struct mfc_cache *ipmr_cache_alloc(void)
973 {
974 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
975 
976 	if (c) {
977 		c->_c.mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
978 		c->_c.mfc_un.res.minvif = MAXVIFS;
979 		c->_c.free = ipmr_cache_free_rcu;
980 		refcount_set(&c->_c.mfc_un.res.refcount, 1);
981 	}
982 	return c;
983 }
984 
985 static struct mfc_cache *ipmr_cache_alloc_unres(void)
986 {
987 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
988 
989 	if (c) {
990 		skb_queue_head_init(&c->_c.mfc_un.unres.unresolved);
991 		c->_c.mfc_un.unres.expires = jiffies + 10 * HZ;
992 	}
993 	return c;
994 }
995 
996 /* A cache entry has gone into a resolved state from queued */
997 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
998 			       struct mfc_cache *uc, struct mfc_cache *c)
999 {
1000 	struct sk_buff *skb;
1001 	struct nlmsgerr *e;
1002 
1003 	/* Play the pending entries through our router */
1004 	while ((skb = __skb_dequeue(&uc->_c.mfc_un.unres.unresolved))) {
1005 		if (ip_hdr(skb)->version == 0) {
1006 			struct nlmsghdr *nlh = skb_pull(skb,
1007 							sizeof(struct iphdr));
1008 
1009 			if (mr_fill_mroute(mrt, skb, &c->_c,
1010 					   nlmsg_data(nlh)) > 0) {
1011 				nlh->nlmsg_len = skb_tail_pointer(skb) -
1012 						 (u8 *)nlh;
1013 			} else {
1014 				nlh->nlmsg_type = NLMSG_ERROR;
1015 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
1016 				skb_trim(skb, nlh->nlmsg_len);
1017 				e = nlmsg_data(nlh);
1018 				e->error = -EMSGSIZE;
1019 				memset(&e->msg, 0, sizeof(e->msg));
1020 			}
1021 
1022 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
1023 		} else {
1024 			rcu_read_lock();
1025 			ip_mr_forward(net, mrt, skb->dev, skb, c, 0);
1026 			rcu_read_unlock();
1027 		}
1028 	}
1029 }
1030 
1031 /* Bounce a cache query up to mrouted and netlink.
1032  *
1033  * Called under rcu_read_lock().
1034  */
1035 static int ipmr_cache_report(const struct mr_table *mrt,
1036 			     struct sk_buff *pkt, vifi_t vifi, int assert)
1037 {
1038 	const int ihl = ip_hdrlen(pkt);
1039 	struct sock *mroute_sk;
1040 	struct igmphdr *igmp;
1041 	struct igmpmsg *msg;
1042 	struct sk_buff *skb;
1043 	int ret;
1044 
1045 	mroute_sk = rcu_dereference(mrt->mroute_sk);
1046 	if (!mroute_sk)
1047 		return -EINVAL;
1048 
1049 	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE)
1050 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
1051 	else
1052 		skb = alloc_skb(128, GFP_ATOMIC);
1053 
1054 	if (!skb)
1055 		return -ENOBUFS;
1056 
1057 	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE) {
1058 		/* Ugly, but we have no choice with this interface.
1059 		 * Duplicate old header, fix ihl, length etc.
1060 		 * And all this only to mangle msg->im_msgtype and
1061 		 * to set msg->im_mbz to "mbz" :-)
1062 		 */
1063 		skb_push(skb, sizeof(struct iphdr));
1064 		skb_reset_network_header(skb);
1065 		skb_reset_transport_header(skb);
1066 		msg = (struct igmpmsg *)skb_network_header(skb);
1067 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
1068 		msg->im_msgtype = assert;
1069 		msg->im_mbz = 0;
1070 		if (assert == IGMPMSG_WRVIFWHOLE) {
1071 			msg->im_vif = vifi;
1072 			msg->im_vif_hi = vifi >> 8;
1073 		} else {
1074 			/* Pairs with WRITE_ONCE() in vif_add() and vif_delete() */
1075 			int vif_num = READ_ONCE(mrt->mroute_reg_vif_num);
1076 
1077 			msg->im_vif = vif_num;
1078 			msg->im_vif_hi = vif_num >> 8;
1079 		}
1080 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
1081 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
1082 					     sizeof(struct iphdr));
1083 	} else {
1084 		/* Copy the IP header */
1085 		skb_set_network_header(skb, skb->len);
1086 		skb_put(skb, ihl);
1087 		skb_copy_to_linear_data(skb, pkt->data, ihl);
1088 		/* Flag to the kernel this is a route add */
1089 		ip_hdr(skb)->protocol = 0;
1090 		msg = (struct igmpmsg *)skb_network_header(skb);
1091 		msg->im_vif = vifi;
1092 		msg->im_vif_hi = vifi >> 8;
1093 		ipv4_pktinfo_prepare(mroute_sk, pkt, false);
1094 		memcpy(skb->cb, pkt->cb, sizeof(skb->cb));
1095 		/* Add our header */
1096 		igmp = skb_put(skb, sizeof(struct igmphdr));
1097 		igmp->type = assert;
1098 		msg->im_msgtype = assert;
1099 		igmp->code = 0;
1100 		ip_hdr(skb)->tot_len = htons(skb->len);	/* Fix the length */
1101 		skb->transport_header = skb->network_header;
1102 	}
1103 
1104 	igmpmsg_netlink_event(mrt, skb);
1105 
1106 	/* Deliver to mrouted */
1107 	ret = sock_queue_rcv_skb(mroute_sk, skb);
1108 
1109 	if (ret < 0) {
1110 		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1111 		kfree_skb(skb);
1112 	}
1113 
1114 	return ret;
1115 }
1116 
1117 /* Queue a packet for resolution. It gets locked cache entry! */
1118 /* Called under rcu_read_lock() */
1119 static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
1120 				 struct sk_buff *skb, struct net_device *dev)
1121 {
1122 	const struct iphdr *iph = ip_hdr(skb);
1123 	struct mfc_cache *c;
1124 	bool found = false;
1125 	int err;
1126 
1127 	spin_lock_bh(&mfc_unres_lock);
1128 	list_for_each_entry(c, &mrt->mfc_unres_queue, _c.list) {
1129 		if (c->mfc_mcastgrp == iph->daddr &&
1130 		    c->mfc_origin == iph->saddr) {
1131 			found = true;
1132 			break;
1133 		}
1134 	}
1135 
1136 	if (!found) {
1137 		/* Create a new entry if allowable */
1138 		c = ipmr_cache_alloc_unres();
1139 		if (!c) {
1140 			spin_unlock_bh(&mfc_unres_lock);
1141 
1142 			kfree_skb(skb);
1143 			return -ENOBUFS;
1144 		}
1145 
1146 		/* Fill in the new cache entry */
1147 		c->_c.mfc_parent = -1;
1148 		c->mfc_origin	= iph->saddr;
1149 		c->mfc_mcastgrp	= iph->daddr;
1150 
1151 		/* Reflect first query at mrouted. */
1152 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1153 
1154 		if (err < 0) {
1155 			/* If the report failed throw the cache entry
1156 			   out - Brad Parker
1157 			 */
1158 			spin_unlock_bh(&mfc_unres_lock);
1159 
1160 			ipmr_cache_free(c);
1161 			kfree_skb(skb);
1162 			return err;
1163 		}
1164 
1165 		atomic_inc(&mrt->cache_resolve_queue_len);
1166 		list_add(&c->_c.list, &mrt->mfc_unres_queue);
1167 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1168 
1169 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1170 			mod_timer(&mrt->ipmr_expire_timer,
1171 				  c->_c.mfc_un.unres.expires);
1172 	}
1173 
1174 	/* See if we can append the packet */
1175 	if (c->_c.mfc_un.unres.unresolved.qlen > 3) {
1176 		kfree_skb(skb);
1177 		err = -ENOBUFS;
1178 	} else {
1179 		if (dev) {
1180 			skb->dev = dev;
1181 			skb->skb_iif = dev->ifindex;
1182 		}
1183 		skb_queue_tail(&c->_c.mfc_un.unres.unresolved, skb);
1184 		err = 0;
1185 	}
1186 
1187 	spin_unlock_bh(&mfc_unres_lock);
1188 	return err;
1189 }
1190 
1191 /* MFC cache manipulation by user space mroute daemon */
1192 
1193 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1194 {
1195 	struct net *net = read_pnet(&mrt->net);
1196 	struct mfc_cache *c;
1197 
1198 	/* The entries are added/deleted only under RTNL */
1199 	rcu_read_lock();
1200 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1201 				   mfc->mfcc_mcastgrp.s_addr, parent);
1202 	rcu_read_unlock();
1203 	if (!c)
1204 		return -ENOENT;
1205 	rhltable_remove(&mrt->mfc_hash, &c->_c.mnode, ipmr_rht_params);
1206 	list_del_rcu(&c->_c.list);
1207 	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, c, mrt->id);
1208 	mroute_netlink_event(mrt, c, RTM_DELROUTE);
1209 	mr_cache_put(&c->_c);
1210 
1211 	return 0;
1212 }
1213 
1214 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1215 			struct mfcctl *mfc, int mrtsock, int parent)
1216 {
1217 	struct mfc_cache *uc, *c;
1218 	struct mr_mfc *_uc;
1219 	bool found;
1220 	int ret;
1221 
1222 	if (mfc->mfcc_parent >= MAXVIFS)
1223 		return -ENFILE;
1224 
1225 	/* The entries are added/deleted only under RTNL */
1226 	rcu_read_lock();
1227 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1228 				   mfc->mfcc_mcastgrp.s_addr, parent);
1229 	rcu_read_unlock();
1230 	if (c) {
1231 		spin_lock(&mrt_lock);
1232 		c->_c.mfc_parent = mfc->mfcc_parent;
1233 		ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
1234 		if (!mrtsock)
1235 			c->_c.mfc_flags |= MFC_STATIC;
1236 		spin_unlock(&mrt_lock);
1237 		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, c,
1238 					      mrt->id);
1239 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1240 		return 0;
1241 	}
1242 
1243 	if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1244 	    !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1245 		return -EINVAL;
1246 
1247 	c = ipmr_cache_alloc();
1248 	if (!c)
1249 		return -ENOMEM;
1250 
1251 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1252 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1253 	c->_c.mfc_parent = mfc->mfcc_parent;
1254 	ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
1255 	if (!mrtsock)
1256 		c->_c.mfc_flags |= MFC_STATIC;
1257 
1258 	ret = rhltable_insert_key(&mrt->mfc_hash, &c->cmparg, &c->_c.mnode,
1259 				  ipmr_rht_params);
1260 	if (ret) {
1261 		pr_err("ipmr: rhtable insert error %d\n", ret);
1262 		ipmr_cache_free(c);
1263 		return ret;
1264 	}
1265 	list_add_tail_rcu(&c->_c.list, &mrt->mfc_cache_list);
1266 	/* Check to see if we resolved a queued list. If so we
1267 	 * need to send on the frames and tidy up.
1268 	 */
1269 	found = false;
1270 	spin_lock_bh(&mfc_unres_lock);
1271 	list_for_each_entry(_uc, &mrt->mfc_unres_queue, list) {
1272 		uc = (struct mfc_cache *)_uc;
1273 		if (uc->mfc_origin == c->mfc_origin &&
1274 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1275 			list_del(&_uc->list);
1276 			atomic_dec(&mrt->cache_resolve_queue_len);
1277 			found = true;
1278 			break;
1279 		}
1280 	}
1281 	if (list_empty(&mrt->mfc_unres_queue))
1282 		timer_delete(&mrt->ipmr_expire_timer);
1283 	spin_unlock_bh(&mfc_unres_lock);
1284 
1285 	if (found) {
1286 		ipmr_cache_resolve(net, mrt, uc, c);
1287 		ipmr_cache_free(uc);
1288 	}
1289 	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, c, mrt->id);
1290 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1291 	return 0;
1292 }
1293 
1294 /* Close the multicast socket, and clear the vif tables etc */
1295 static void mroute_clean_tables(struct mr_table *mrt, int flags)
1296 {
1297 	struct net *net = read_pnet(&mrt->net);
1298 	struct mr_mfc *c, *tmp;
1299 	struct mfc_cache *cache;
1300 	LIST_HEAD(list);
1301 	int i;
1302 
1303 	/* Shut down all active vif entries */
1304 	if (flags & (MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC)) {
1305 		for (i = 0; i < mrt->maxvif; i++) {
1306 			if (((mrt->vif_table[i].flags & VIFF_STATIC) &&
1307 			     !(flags & MRT_FLUSH_VIFS_STATIC)) ||
1308 			    (!(mrt->vif_table[i].flags & VIFF_STATIC) && !(flags & MRT_FLUSH_VIFS)))
1309 				continue;
1310 			vif_delete(mrt, i, 0, &list);
1311 		}
1312 		unregister_netdevice_many(&list);
1313 	}
1314 
1315 	/* Wipe the cache */
1316 	if (flags & (MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC)) {
1317 		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
1318 			if (((c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC_STATIC)) ||
1319 			    (!(c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC)))
1320 				continue;
1321 			rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
1322 			list_del_rcu(&c->list);
1323 			cache = (struct mfc_cache *)c;
1324 			call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
1325 						      mrt->id);
1326 			mroute_netlink_event(mrt, cache, RTM_DELROUTE);
1327 			mr_cache_put(c);
1328 		}
1329 	}
1330 
1331 	if (flags & MRT_FLUSH_MFC) {
1332 		if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1333 			spin_lock_bh(&mfc_unres_lock);
1334 			list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
1335 				list_del(&c->list);
1336 				cache = (struct mfc_cache *)c;
1337 				mroute_netlink_event(mrt, cache, RTM_DELROUTE);
1338 				ipmr_destroy_unres(mrt, cache);
1339 			}
1340 			spin_unlock_bh(&mfc_unres_lock);
1341 		}
1342 	}
1343 }
1344 
1345 /* called from ip_ra_control(), before an RCU grace period,
1346  * we don't need to call synchronize_rcu() here
1347  */
1348 static void mrtsock_destruct(struct sock *sk)
1349 {
1350 	struct net *net = sock_net(sk);
1351 	struct mr_table *mrt;
1352 
1353 	rtnl_lock();
1354 	ipmr_for_each_table(mrt, net) {
1355 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1356 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1357 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1358 						    NETCONFA_MC_FORWARDING,
1359 						    NETCONFA_IFINDEX_ALL,
1360 						    net->ipv4.devconf_all);
1361 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1362 			mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_MFC);
1363 		}
1364 	}
1365 	rtnl_unlock();
1366 }
1367 
1368 /* Socket options and virtual interface manipulation. The whole
1369  * virtual interface system is a complete heap, but unfortunately
1370  * that's how BSD mrouted happens to think. Maybe one day with a proper
1371  * MOSPF/PIM router set up we can clean this up.
1372  */
1373 
1374 int ip_mroute_setsockopt(struct sock *sk, int optname, sockptr_t optval,
1375 			 unsigned int optlen)
1376 {
1377 	struct net *net = sock_net(sk);
1378 	int val, ret = 0, parent = 0;
1379 	struct mr_table *mrt;
1380 	struct vifctl vif;
1381 	struct mfcctl mfc;
1382 	bool do_wrvifwhole;
1383 	u32 uval;
1384 
1385 	/* There's one exception to the lock - MRT_DONE which needs to unlock */
1386 	rtnl_lock();
1387 	if (sk->sk_type != SOCK_RAW ||
1388 	    inet_sk(sk)->inet_num != IPPROTO_IGMP) {
1389 		ret = -EOPNOTSUPP;
1390 		goto out_unlock;
1391 	}
1392 
1393 	mrt = __ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1394 	if (!mrt) {
1395 		ret = -ENOENT;
1396 		goto out_unlock;
1397 	}
1398 	if (optname != MRT_INIT) {
1399 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1400 		    !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
1401 			ret = -EACCES;
1402 			goto out_unlock;
1403 		}
1404 	}
1405 
1406 	switch (optname) {
1407 	case MRT_INIT:
1408 		if (optlen != sizeof(int)) {
1409 			ret = -EINVAL;
1410 			break;
1411 		}
1412 		if (rtnl_dereference(mrt->mroute_sk)) {
1413 			ret = -EADDRINUSE;
1414 			break;
1415 		}
1416 
1417 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1418 		if (ret == 0) {
1419 			rcu_assign_pointer(mrt->mroute_sk, sk);
1420 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1421 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1422 						    NETCONFA_MC_FORWARDING,
1423 						    NETCONFA_IFINDEX_ALL,
1424 						    net->ipv4.devconf_all);
1425 		}
1426 		break;
1427 	case MRT_DONE:
1428 		if (sk != rcu_access_pointer(mrt->mroute_sk)) {
1429 			ret = -EACCES;
1430 		} else {
1431 			/* We need to unlock here because mrtsock_destruct takes
1432 			 * care of rtnl itself and we can't change that due to
1433 			 * the IP_ROUTER_ALERT setsockopt which runs without it.
1434 			 */
1435 			rtnl_unlock();
1436 			ret = ip_ra_control(sk, 0, NULL);
1437 			goto out;
1438 		}
1439 		break;
1440 	case MRT_ADD_VIF:
1441 	case MRT_DEL_VIF:
1442 		if (optlen != sizeof(vif)) {
1443 			ret = -EINVAL;
1444 			break;
1445 		}
1446 		if (copy_from_sockptr(&vif, optval, sizeof(vif))) {
1447 			ret = -EFAULT;
1448 			break;
1449 		}
1450 		if (vif.vifc_vifi >= MAXVIFS) {
1451 			ret = -ENFILE;
1452 			break;
1453 		}
1454 		if (optname == MRT_ADD_VIF) {
1455 			ret = vif_add(net, mrt, &vif,
1456 				      sk == rtnl_dereference(mrt->mroute_sk));
1457 		} else {
1458 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1459 		}
1460 		break;
1461 	/* Manipulate the forwarding caches. These live
1462 	 * in a sort of kernel/user symbiosis.
1463 	 */
1464 	case MRT_ADD_MFC:
1465 	case MRT_DEL_MFC:
1466 		parent = -1;
1467 		fallthrough;
1468 	case MRT_ADD_MFC_PROXY:
1469 	case MRT_DEL_MFC_PROXY:
1470 		if (optlen != sizeof(mfc)) {
1471 			ret = -EINVAL;
1472 			break;
1473 		}
1474 		if (copy_from_sockptr(&mfc, optval, sizeof(mfc))) {
1475 			ret = -EFAULT;
1476 			break;
1477 		}
1478 		if (parent == 0)
1479 			parent = mfc.mfcc_parent;
1480 		if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1481 			ret = ipmr_mfc_delete(mrt, &mfc, parent);
1482 		else
1483 			ret = ipmr_mfc_add(net, mrt, &mfc,
1484 					   sk == rtnl_dereference(mrt->mroute_sk),
1485 					   parent);
1486 		break;
1487 	case MRT_FLUSH:
1488 		if (optlen != sizeof(val)) {
1489 			ret = -EINVAL;
1490 			break;
1491 		}
1492 		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1493 			ret = -EFAULT;
1494 			break;
1495 		}
1496 		mroute_clean_tables(mrt, val);
1497 		break;
1498 	/* Control PIM assert. */
1499 	case MRT_ASSERT:
1500 		if (optlen != sizeof(val)) {
1501 			ret = -EINVAL;
1502 			break;
1503 		}
1504 		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1505 			ret = -EFAULT;
1506 			break;
1507 		}
1508 		mrt->mroute_do_assert = val;
1509 		break;
1510 	case MRT_PIM:
1511 		if (!ipmr_pimsm_enabled()) {
1512 			ret = -ENOPROTOOPT;
1513 			break;
1514 		}
1515 		if (optlen != sizeof(val)) {
1516 			ret = -EINVAL;
1517 			break;
1518 		}
1519 		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1520 			ret = -EFAULT;
1521 			break;
1522 		}
1523 
1524 		do_wrvifwhole = (val == IGMPMSG_WRVIFWHOLE);
1525 		val = !!val;
1526 		if (val != mrt->mroute_do_pim) {
1527 			mrt->mroute_do_pim = val;
1528 			mrt->mroute_do_assert = val;
1529 			mrt->mroute_do_wrvifwhole = do_wrvifwhole;
1530 		}
1531 		break;
1532 	case MRT_TABLE:
1533 		if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) {
1534 			ret = -ENOPROTOOPT;
1535 			break;
1536 		}
1537 		if (optlen != sizeof(uval)) {
1538 			ret = -EINVAL;
1539 			break;
1540 		}
1541 		if (copy_from_sockptr(&uval, optval, sizeof(uval))) {
1542 			ret = -EFAULT;
1543 			break;
1544 		}
1545 
1546 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1547 			ret = -EBUSY;
1548 		} else {
1549 			mrt = ipmr_new_table(net, uval);
1550 			if (IS_ERR(mrt))
1551 				ret = PTR_ERR(mrt);
1552 			else
1553 				raw_sk(sk)->ipmr_table = uval;
1554 		}
1555 		break;
1556 	/* Spurious command, or MRT_VERSION which you cannot set. */
1557 	default:
1558 		ret = -ENOPROTOOPT;
1559 	}
1560 out_unlock:
1561 	rtnl_unlock();
1562 out:
1563 	return ret;
1564 }
1565 
1566 /* Execute if this ioctl is a special mroute ioctl */
1567 int ipmr_sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1568 {
1569 	switch (cmd) {
1570 	/* These userspace buffers will be consumed by ipmr_ioctl() */
1571 	case SIOCGETVIFCNT: {
1572 		struct sioc_vif_req buffer;
1573 
1574 		return sock_ioctl_inout(sk, cmd, arg, &buffer,
1575 				      sizeof(buffer));
1576 		}
1577 	case SIOCGETSGCNT: {
1578 		struct sioc_sg_req buffer;
1579 
1580 		return sock_ioctl_inout(sk, cmd, arg, &buffer,
1581 				      sizeof(buffer));
1582 		}
1583 	}
1584 	/* return code > 0 means that the ioctl was not executed */
1585 	return 1;
1586 }
1587 
1588 /* Getsock opt support for the multicast routing system. */
1589 int ip_mroute_getsockopt(struct sock *sk, int optname, sockptr_t optval,
1590 			 sockptr_t optlen)
1591 {
1592 	int olr;
1593 	int val;
1594 	struct net *net = sock_net(sk);
1595 	struct mr_table *mrt;
1596 
1597 	if (sk->sk_type != SOCK_RAW ||
1598 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1599 		return -EOPNOTSUPP;
1600 
1601 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1602 	if (!mrt)
1603 		return -ENOENT;
1604 
1605 	switch (optname) {
1606 	case MRT_VERSION:
1607 		val = 0x0305;
1608 		break;
1609 	case MRT_PIM:
1610 		if (!ipmr_pimsm_enabled())
1611 			return -ENOPROTOOPT;
1612 		val = mrt->mroute_do_pim;
1613 		break;
1614 	case MRT_ASSERT:
1615 		val = mrt->mroute_do_assert;
1616 		break;
1617 	default:
1618 		return -ENOPROTOOPT;
1619 	}
1620 
1621 	if (copy_from_sockptr(&olr, optlen, sizeof(int)))
1622 		return -EFAULT;
1623 	if (olr < 0)
1624 		return -EINVAL;
1625 
1626 	olr = min_t(unsigned int, olr, sizeof(int));
1627 
1628 	if (copy_to_sockptr(optlen, &olr, sizeof(int)))
1629 		return -EFAULT;
1630 	if (copy_to_sockptr(optval, &val, olr))
1631 		return -EFAULT;
1632 	return 0;
1633 }
1634 
1635 /* The IP multicast ioctl support routines. */
1636 int ipmr_ioctl(struct sock *sk, int cmd, void *arg)
1637 {
1638 	struct vif_device *vif;
1639 	struct mfc_cache *c;
1640 	struct net *net = sock_net(sk);
1641 	struct sioc_vif_req *vr;
1642 	struct sioc_sg_req *sr;
1643 	struct mr_table *mrt;
1644 
1645 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1646 	if (!mrt)
1647 		return -ENOENT;
1648 
1649 	switch (cmd) {
1650 	case SIOCGETVIFCNT:
1651 		vr = (struct sioc_vif_req *)arg;
1652 		if (vr->vifi >= mrt->maxvif)
1653 			return -EINVAL;
1654 		vr->vifi = array_index_nospec(vr->vifi, mrt->maxvif);
1655 		rcu_read_lock();
1656 		vif = &mrt->vif_table[vr->vifi];
1657 		if (VIF_EXISTS(mrt, vr->vifi)) {
1658 			vr->icount = READ_ONCE(vif->pkt_in);
1659 			vr->ocount = READ_ONCE(vif->pkt_out);
1660 			vr->ibytes = READ_ONCE(vif->bytes_in);
1661 			vr->obytes = READ_ONCE(vif->bytes_out);
1662 			rcu_read_unlock();
1663 
1664 			return 0;
1665 		}
1666 		rcu_read_unlock();
1667 		return -EADDRNOTAVAIL;
1668 	case SIOCGETSGCNT:
1669 		sr = (struct sioc_sg_req *)arg;
1670 
1671 		rcu_read_lock();
1672 		c = ipmr_cache_find(mrt, sr->src.s_addr, sr->grp.s_addr);
1673 		if (c) {
1674 			sr->pktcnt = atomic_long_read(&c->_c.mfc_un.res.pkt);
1675 			sr->bytecnt = atomic_long_read(&c->_c.mfc_un.res.bytes);
1676 			sr->wrong_if = atomic_long_read(&c->_c.mfc_un.res.wrong_if);
1677 			rcu_read_unlock();
1678 			return 0;
1679 		}
1680 		rcu_read_unlock();
1681 		return -EADDRNOTAVAIL;
1682 	default:
1683 		return -ENOIOCTLCMD;
1684 	}
1685 }
1686 
1687 #ifdef CONFIG_COMPAT
1688 struct compat_sioc_sg_req {
1689 	struct in_addr src;
1690 	struct in_addr grp;
1691 	compat_ulong_t pktcnt;
1692 	compat_ulong_t bytecnt;
1693 	compat_ulong_t wrong_if;
1694 };
1695 
1696 struct compat_sioc_vif_req {
1697 	vifi_t	vifi;		/* Which iface */
1698 	compat_ulong_t icount;
1699 	compat_ulong_t ocount;
1700 	compat_ulong_t ibytes;
1701 	compat_ulong_t obytes;
1702 };
1703 
1704 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1705 {
1706 	struct compat_sioc_sg_req sr;
1707 	struct compat_sioc_vif_req vr;
1708 	struct vif_device *vif;
1709 	struct mfc_cache *c;
1710 	struct net *net = sock_net(sk);
1711 	struct mr_table *mrt;
1712 
1713 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1714 	if (!mrt)
1715 		return -ENOENT;
1716 
1717 	switch (cmd) {
1718 	case SIOCGETVIFCNT:
1719 		if (copy_from_user(&vr, arg, sizeof(vr)))
1720 			return -EFAULT;
1721 		if (vr.vifi >= mrt->maxvif)
1722 			return -EINVAL;
1723 		vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif);
1724 		rcu_read_lock();
1725 		vif = &mrt->vif_table[vr.vifi];
1726 		if (VIF_EXISTS(mrt, vr.vifi)) {
1727 			vr.icount = READ_ONCE(vif->pkt_in);
1728 			vr.ocount = READ_ONCE(vif->pkt_out);
1729 			vr.ibytes = READ_ONCE(vif->bytes_in);
1730 			vr.obytes = READ_ONCE(vif->bytes_out);
1731 			rcu_read_unlock();
1732 
1733 			if (copy_to_user(arg, &vr, sizeof(vr)))
1734 				return -EFAULT;
1735 			return 0;
1736 		}
1737 		rcu_read_unlock();
1738 		return -EADDRNOTAVAIL;
1739 	case SIOCGETSGCNT:
1740 		if (copy_from_user(&sr, arg, sizeof(sr)))
1741 			return -EFAULT;
1742 
1743 		rcu_read_lock();
1744 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1745 		if (c) {
1746 			sr.pktcnt = atomic_long_read(&c->_c.mfc_un.res.pkt);
1747 			sr.bytecnt = atomic_long_read(&c->_c.mfc_un.res.bytes);
1748 			sr.wrong_if = atomic_long_read(&c->_c.mfc_un.res.wrong_if);
1749 			rcu_read_unlock();
1750 
1751 			if (copy_to_user(arg, &sr, sizeof(sr)))
1752 				return -EFAULT;
1753 			return 0;
1754 		}
1755 		rcu_read_unlock();
1756 		return -EADDRNOTAVAIL;
1757 	default:
1758 		return -ENOIOCTLCMD;
1759 	}
1760 }
1761 #endif
1762 
1763 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1764 {
1765 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1766 	struct net *net = dev_net(dev);
1767 	struct mr_table *mrt;
1768 	struct vif_device *v;
1769 	int ct;
1770 
1771 	if (event != NETDEV_UNREGISTER)
1772 		return NOTIFY_DONE;
1773 
1774 	ipmr_for_each_table(mrt, net) {
1775 		v = &mrt->vif_table[0];
1776 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1777 			if (rcu_access_pointer(v->dev) == dev)
1778 				vif_delete(mrt, ct, 1, NULL);
1779 		}
1780 	}
1781 	return NOTIFY_DONE;
1782 }
1783 
1784 static struct notifier_block ip_mr_notifier = {
1785 	.notifier_call = ipmr_device_event,
1786 };
1787 
1788 /* Encapsulate a packet by attaching a valid IPIP header to it.
1789  * This avoids tunnel drivers and other mess and gives us the speed so
1790  * important for multicast video.
1791  */
1792 static void ip_encap(struct net *net, struct sk_buff *skb,
1793 		     __be32 saddr, __be32 daddr)
1794 {
1795 	struct iphdr *iph;
1796 	const struct iphdr *old_iph = ip_hdr(skb);
1797 
1798 	skb_push(skb, sizeof(struct iphdr));
1799 	skb->transport_header = skb->network_header;
1800 	skb_reset_network_header(skb);
1801 	iph = ip_hdr(skb);
1802 
1803 	iph->version	=	4;
1804 	iph->tos	=	old_iph->tos;
1805 	iph->ttl	=	old_iph->ttl;
1806 	iph->frag_off	=	0;
1807 	iph->daddr	=	daddr;
1808 	iph->saddr	=	saddr;
1809 	iph->protocol	=	IPPROTO_IPIP;
1810 	iph->ihl	=	5;
1811 	iph->tot_len	=	htons(skb->len);
1812 	ip_select_ident(net, skb, NULL);
1813 	ip_send_check(iph);
1814 
1815 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1816 	nf_reset_ct(skb);
1817 }
1818 
1819 static inline int ipmr_forward_finish(struct net *net, struct sock *sk,
1820 				      struct sk_buff *skb)
1821 {
1822 	struct ip_options *opt = &(IPCB(skb)->opt);
1823 
1824 	IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
1825 
1826 	if (unlikely(opt->optlen))
1827 		ip_forward_options(skb);
1828 
1829 	return dst_output(net, sk, skb);
1830 }
1831 
1832 #ifdef CONFIG_NET_SWITCHDEV
1833 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1834 				   int in_vifi, int out_vifi)
1835 {
1836 	struct vif_device *out_vif = &mrt->vif_table[out_vifi];
1837 	struct vif_device *in_vif = &mrt->vif_table[in_vifi];
1838 
1839 	if (!skb->offload_l3_fwd_mark)
1840 		return false;
1841 	if (!out_vif->dev_parent_id.id_len || !in_vif->dev_parent_id.id_len)
1842 		return false;
1843 	return netdev_phys_item_id_same(&out_vif->dev_parent_id,
1844 					&in_vif->dev_parent_id);
1845 }
1846 #else
1847 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1848 				   int in_vifi, int out_vifi)
1849 {
1850 	return false;
1851 }
1852 #endif
1853 
1854 /* Processing handlers for ipmr_forward, under rcu_read_lock() */
1855 
1856 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1857 			    int in_vifi, struct sk_buff *skb, int vifi)
1858 {
1859 	const struct iphdr *iph = ip_hdr(skb);
1860 	struct vif_device *vif = &mrt->vif_table[vifi];
1861 	struct net_device *vif_dev;
1862 	struct net_device *dev;
1863 	struct rtable *rt;
1864 	struct flowi4 fl4;
1865 	int    encap = 0;
1866 
1867 	vif_dev = vif_dev_read(vif);
1868 	if (!vif_dev)
1869 		goto out_free;
1870 
1871 	if (vif->flags & VIFF_REGISTER) {
1872 		WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
1873 		WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len);
1874 		DEV_STATS_ADD(vif_dev, tx_bytes, skb->len);
1875 		DEV_STATS_INC(vif_dev, tx_packets);
1876 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1877 		goto out_free;
1878 	}
1879 
1880 	if (ipmr_forward_offloaded(skb, mrt, in_vifi, vifi))
1881 		goto out_free;
1882 
1883 	if (vif->flags & VIFF_TUNNEL) {
1884 		rt = ip_route_output_ports(net, &fl4, NULL,
1885 					   vif->remote, vif->local,
1886 					   0, 0,
1887 					   IPPROTO_IPIP,
1888 					   iph->tos & INET_DSCP_MASK, vif->link);
1889 		if (IS_ERR(rt))
1890 			goto out_free;
1891 		encap = sizeof(struct iphdr);
1892 	} else {
1893 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1894 					   0, 0,
1895 					   IPPROTO_IPIP,
1896 					   iph->tos & INET_DSCP_MASK, vif->link);
1897 		if (IS_ERR(rt))
1898 			goto out_free;
1899 	}
1900 
1901 	dev = rt->dst.dev;
1902 
1903 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1904 		/* Do not fragment multicasts. Alas, IPv4 does not
1905 		 * allow to send ICMP, so that packets will disappear
1906 		 * to blackhole.
1907 		 */
1908 		IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
1909 		ip_rt_put(rt);
1910 		goto out_free;
1911 	}
1912 
1913 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1914 
1915 	if (skb_cow(skb, encap)) {
1916 		ip_rt_put(rt);
1917 		goto out_free;
1918 	}
1919 
1920 	WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
1921 	WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len);
1922 
1923 	skb_dst_drop(skb);
1924 	skb_dst_set(skb, &rt->dst);
1925 	ip_decrease_ttl(ip_hdr(skb));
1926 
1927 	/* FIXME: forward and output firewalls used to be called here.
1928 	 * What do we do with netfilter? -- RR
1929 	 */
1930 	if (vif->flags & VIFF_TUNNEL) {
1931 		ip_encap(net, skb, vif->local, vif->remote);
1932 		/* FIXME: extra output firewall step used to be here. --RR */
1933 		DEV_STATS_INC(vif_dev, tx_packets);
1934 		DEV_STATS_ADD(vif_dev, tx_bytes, skb->len);
1935 	}
1936 
1937 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1938 
1939 	/* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1940 	 * not only before forwarding, but after forwarding on all output
1941 	 * interfaces. It is clear, if mrouter runs a multicasting
1942 	 * program, it should receive packets not depending to what interface
1943 	 * program is joined.
1944 	 * If we will not make it, the program will have to join on all
1945 	 * interfaces. On the other hand, multihoming host (or router, but
1946 	 * not mrouter) cannot join to more than one interface - it will
1947 	 * result in receiving multiple packets.
1948 	 */
1949 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
1950 		net, NULL, skb, skb->dev, dev,
1951 		ipmr_forward_finish);
1952 	return;
1953 
1954 out_free:
1955 	kfree_skb(skb);
1956 }
1957 
1958 /* Called with mrt_lock or rcu_read_lock() */
1959 static int ipmr_find_vif(const struct mr_table *mrt, struct net_device *dev)
1960 {
1961 	int ct;
1962 	/* Pairs with WRITE_ONCE() in vif_delete()/vif_add() */
1963 	for (ct = READ_ONCE(mrt->maxvif) - 1; ct >= 0; ct--) {
1964 		if (rcu_access_pointer(mrt->vif_table[ct].dev) == dev)
1965 			break;
1966 	}
1967 	return ct;
1968 }
1969 
1970 /* "local" means that we should preserve one skb (for local delivery) */
1971 /* Called uner rcu_read_lock() */
1972 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
1973 			  struct net_device *dev, struct sk_buff *skb,
1974 			  struct mfc_cache *c, int local)
1975 {
1976 	int true_vifi = ipmr_find_vif(mrt, dev);
1977 	int psend = -1;
1978 	int vif, ct;
1979 
1980 	vif = c->_c.mfc_parent;
1981 	atomic_long_inc(&c->_c.mfc_un.res.pkt);
1982 	atomic_long_add(skb->len, &c->_c.mfc_un.res.bytes);
1983 	WRITE_ONCE(c->_c.mfc_un.res.lastuse, jiffies);
1984 
1985 	if (c->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
1986 		struct mfc_cache *cache_proxy;
1987 
1988 		/* For an (*,G) entry, we only check that the incoming
1989 		 * interface is part of the static tree.
1990 		 */
1991 		cache_proxy = mr_mfc_find_any_parent(mrt, vif);
1992 		if (cache_proxy &&
1993 		    cache_proxy->_c.mfc_un.res.ttls[true_vifi] < 255)
1994 			goto forward;
1995 	}
1996 
1997 	/* Wrong interface: drop packet and (maybe) send PIM assert. */
1998 	if (rcu_access_pointer(mrt->vif_table[vif].dev) != dev) {
1999 		if (rt_is_output_route(skb_rtable(skb))) {
2000 			/* It is our own packet, looped back.
2001 			 * Very complicated situation...
2002 			 *
2003 			 * The best workaround until routing daemons will be
2004 			 * fixed is not to redistribute packet, if it was
2005 			 * send through wrong interface. It means, that
2006 			 * multicast applications WILL NOT work for
2007 			 * (S,G), which have default multicast route pointing
2008 			 * to wrong oif. In any case, it is not a good
2009 			 * idea to use multicasting applications on router.
2010 			 */
2011 			goto dont_forward;
2012 		}
2013 
2014 		atomic_long_inc(&c->_c.mfc_un.res.wrong_if);
2015 
2016 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
2017 		    /* pimsm uses asserts, when switching from RPT to SPT,
2018 		     * so that we cannot check that packet arrived on an oif.
2019 		     * It is bad, but otherwise we would need to move pretty
2020 		     * large chunk of pimd to kernel. Ough... --ANK
2021 		     */
2022 		    (mrt->mroute_do_pim ||
2023 		     c->_c.mfc_un.res.ttls[true_vifi] < 255) &&
2024 		    time_after(jiffies,
2025 			       c->_c.mfc_un.res.last_assert +
2026 			       MFC_ASSERT_THRESH)) {
2027 			c->_c.mfc_un.res.last_assert = jiffies;
2028 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
2029 			if (mrt->mroute_do_wrvifwhole)
2030 				ipmr_cache_report(mrt, skb, true_vifi,
2031 						  IGMPMSG_WRVIFWHOLE);
2032 		}
2033 		goto dont_forward;
2034 	}
2035 
2036 forward:
2037 	WRITE_ONCE(mrt->vif_table[vif].pkt_in,
2038 		   mrt->vif_table[vif].pkt_in + 1);
2039 	WRITE_ONCE(mrt->vif_table[vif].bytes_in,
2040 		   mrt->vif_table[vif].bytes_in + skb->len);
2041 
2042 	/* Forward the frame */
2043 	if (c->mfc_origin == htonl(INADDR_ANY) &&
2044 	    c->mfc_mcastgrp == htonl(INADDR_ANY)) {
2045 		if (true_vifi >= 0 &&
2046 		    true_vifi != c->_c.mfc_parent &&
2047 		    ip_hdr(skb)->ttl >
2048 				c->_c.mfc_un.res.ttls[c->_c.mfc_parent]) {
2049 			/* It's an (*,*) entry and the packet is not coming from
2050 			 * the upstream: forward the packet to the upstream
2051 			 * only.
2052 			 */
2053 			psend = c->_c.mfc_parent;
2054 			goto last_forward;
2055 		}
2056 		goto dont_forward;
2057 	}
2058 	for (ct = c->_c.mfc_un.res.maxvif - 1;
2059 	     ct >= c->_c.mfc_un.res.minvif; ct--) {
2060 		/* For (*,G) entry, don't forward to the incoming interface */
2061 		if ((c->mfc_origin != htonl(INADDR_ANY) ||
2062 		     ct != true_vifi) &&
2063 		    ip_hdr(skb)->ttl > c->_c.mfc_un.res.ttls[ct]) {
2064 			if (psend != -1) {
2065 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2066 
2067 				if (skb2)
2068 					ipmr_queue_xmit(net, mrt, true_vifi,
2069 							skb2, psend);
2070 			}
2071 			psend = ct;
2072 		}
2073 	}
2074 last_forward:
2075 	if (psend != -1) {
2076 		if (local) {
2077 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2078 
2079 			if (skb2)
2080 				ipmr_queue_xmit(net, mrt, true_vifi, skb2,
2081 						psend);
2082 		} else {
2083 			ipmr_queue_xmit(net, mrt, true_vifi, skb, psend);
2084 			return;
2085 		}
2086 	}
2087 
2088 dont_forward:
2089 	if (!local)
2090 		kfree_skb(skb);
2091 }
2092 
2093 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
2094 {
2095 	struct rtable *rt = skb_rtable(skb);
2096 	struct iphdr *iph = ip_hdr(skb);
2097 	struct flowi4 fl4 = {
2098 		.daddr = iph->daddr,
2099 		.saddr = iph->saddr,
2100 		.flowi4_tos = inet_dscp_to_dsfield(ip4h_dscp(iph)),
2101 		.flowi4_oif = (rt_is_output_route(rt) ?
2102 			       skb->dev->ifindex : 0),
2103 		.flowi4_iif = (rt_is_output_route(rt) ?
2104 			       LOOPBACK_IFINDEX :
2105 			       skb->dev->ifindex),
2106 		.flowi4_mark = skb->mark,
2107 	};
2108 	struct mr_table *mrt;
2109 	int err;
2110 
2111 	err = ipmr_fib_lookup(net, &fl4, &mrt);
2112 	if (err)
2113 		return ERR_PTR(err);
2114 	return mrt;
2115 }
2116 
2117 /* Multicast packets for forwarding arrive here
2118  * Called with rcu_read_lock();
2119  */
2120 int ip_mr_input(struct sk_buff *skb)
2121 {
2122 	struct mfc_cache *cache;
2123 	struct net *net = dev_net(skb->dev);
2124 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
2125 	struct mr_table *mrt;
2126 	struct net_device *dev;
2127 
2128 	/* skb->dev passed in is the loX master dev for vrfs.
2129 	 * As there are no vifs associated with loopback devices,
2130 	 * get the proper interface that does have a vif associated with it.
2131 	 */
2132 	dev = skb->dev;
2133 	if (netif_is_l3_master(skb->dev)) {
2134 		dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
2135 		if (!dev) {
2136 			kfree_skb(skb);
2137 			return -ENODEV;
2138 		}
2139 	}
2140 
2141 	/* Packet is looped back after forward, it should not be
2142 	 * forwarded second time, but still can be delivered locally.
2143 	 */
2144 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
2145 		goto dont_forward;
2146 
2147 	mrt = ipmr_rt_fib_lookup(net, skb);
2148 	if (IS_ERR(mrt)) {
2149 		kfree_skb(skb);
2150 		return PTR_ERR(mrt);
2151 	}
2152 	if (!local) {
2153 		if (IPCB(skb)->opt.router_alert) {
2154 			if (ip_call_ra_chain(skb))
2155 				return 0;
2156 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
2157 			/* IGMPv1 (and broken IGMPv2 implementations sort of
2158 			 * Cisco IOS <= 11.2(8)) do not put router alert
2159 			 * option to IGMP packets destined to routable
2160 			 * groups. It is very bad, because it means
2161 			 * that we can forward NO IGMP messages.
2162 			 */
2163 			struct sock *mroute_sk;
2164 
2165 			mroute_sk = rcu_dereference(mrt->mroute_sk);
2166 			if (mroute_sk) {
2167 				nf_reset_ct(skb);
2168 				raw_rcv(mroute_sk, skb);
2169 				return 0;
2170 			}
2171 		}
2172 	}
2173 
2174 	/* already under rcu_read_lock() */
2175 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
2176 	if (!cache) {
2177 		int vif = ipmr_find_vif(mrt, dev);
2178 
2179 		if (vif >= 0)
2180 			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
2181 						    vif);
2182 	}
2183 
2184 	/* No usable cache entry */
2185 	if (!cache) {
2186 		int vif;
2187 
2188 		if (local) {
2189 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2190 			ip_local_deliver(skb);
2191 			if (!skb2)
2192 				return -ENOBUFS;
2193 			skb = skb2;
2194 		}
2195 
2196 		vif = ipmr_find_vif(mrt, dev);
2197 		if (vif >= 0)
2198 			return ipmr_cache_unresolved(mrt, vif, skb, dev);
2199 		kfree_skb(skb);
2200 		return -ENODEV;
2201 	}
2202 
2203 	ip_mr_forward(net, mrt, dev, skb, cache, local);
2204 
2205 	if (local)
2206 		return ip_local_deliver(skb);
2207 
2208 	return 0;
2209 
2210 dont_forward:
2211 	if (local)
2212 		return ip_local_deliver(skb);
2213 	kfree_skb(skb);
2214 	return 0;
2215 }
2216 
2217 #ifdef CONFIG_IP_PIMSM_V1
2218 /* Handle IGMP messages of PIMv1 */
2219 int pim_rcv_v1(struct sk_buff *skb)
2220 {
2221 	struct igmphdr *pim;
2222 	struct net *net = dev_net(skb->dev);
2223 	struct mr_table *mrt;
2224 
2225 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2226 		goto drop;
2227 
2228 	pim = igmp_hdr(skb);
2229 
2230 	mrt = ipmr_rt_fib_lookup(net, skb);
2231 	if (IS_ERR(mrt))
2232 		goto drop;
2233 	if (!mrt->mroute_do_pim ||
2234 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2235 		goto drop;
2236 
2237 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2238 drop:
2239 		kfree_skb(skb);
2240 	}
2241 	return 0;
2242 }
2243 #endif
2244 
2245 #ifdef CONFIG_IP_PIMSM_V2
2246 static int pim_rcv(struct sk_buff *skb)
2247 {
2248 	struct pimreghdr *pim;
2249 	struct net *net = dev_net(skb->dev);
2250 	struct mr_table *mrt;
2251 
2252 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2253 		goto drop;
2254 
2255 	pim = (struct pimreghdr *)skb_transport_header(skb);
2256 	if (pim->type != ((PIM_VERSION << 4) | (PIM_TYPE_REGISTER)) ||
2257 	    (pim->flags & PIM_NULL_REGISTER) ||
2258 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2259 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2260 		goto drop;
2261 
2262 	mrt = ipmr_rt_fib_lookup(net, skb);
2263 	if (IS_ERR(mrt))
2264 		goto drop;
2265 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2266 drop:
2267 		kfree_skb(skb);
2268 	}
2269 	return 0;
2270 }
2271 #endif
2272 
2273 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2274 		   __be32 saddr, __be32 daddr,
2275 		   struct rtmsg *rtm, u32 portid)
2276 {
2277 	struct mfc_cache *cache;
2278 	struct mr_table *mrt;
2279 	int err;
2280 
2281 	rcu_read_lock();
2282 	mrt = __ipmr_get_table(net, RT_TABLE_DEFAULT);
2283 	if (!mrt) {
2284 		rcu_read_unlock();
2285 		return -ENOENT;
2286 	}
2287 
2288 	cache = ipmr_cache_find(mrt, saddr, daddr);
2289 	if (!cache && skb->dev) {
2290 		int vif = ipmr_find_vif(mrt, skb->dev);
2291 
2292 		if (vif >= 0)
2293 			cache = ipmr_cache_find_any(mrt, daddr, vif);
2294 	}
2295 	if (!cache) {
2296 		struct sk_buff *skb2;
2297 		struct iphdr *iph;
2298 		struct net_device *dev;
2299 		int vif = -1;
2300 
2301 		dev = skb->dev;
2302 		if (dev)
2303 			vif = ipmr_find_vif(mrt, dev);
2304 		if (vif < 0) {
2305 			rcu_read_unlock();
2306 			return -ENODEV;
2307 		}
2308 
2309 		skb2 = skb_realloc_headroom(skb, sizeof(struct iphdr));
2310 		if (!skb2) {
2311 			rcu_read_unlock();
2312 			return -ENOMEM;
2313 		}
2314 
2315 		NETLINK_CB(skb2).portid = portid;
2316 		skb_push(skb2, sizeof(struct iphdr));
2317 		skb_reset_network_header(skb2);
2318 		iph = ip_hdr(skb2);
2319 		iph->ihl = sizeof(struct iphdr) >> 2;
2320 		iph->saddr = saddr;
2321 		iph->daddr = daddr;
2322 		iph->version = 0;
2323 		err = ipmr_cache_unresolved(mrt, vif, skb2, dev);
2324 		rcu_read_unlock();
2325 		return err;
2326 	}
2327 
2328 	err = mr_fill_mroute(mrt, skb, &cache->_c, rtm);
2329 	rcu_read_unlock();
2330 	return err;
2331 }
2332 
2333 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2334 			    u32 portid, u32 seq, struct mfc_cache *c, int cmd,
2335 			    int flags)
2336 {
2337 	struct nlmsghdr *nlh;
2338 	struct rtmsg *rtm;
2339 	int err;
2340 
2341 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2342 	if (!nlh)
2343 		return -EMSGSIZE;
2344 
2345 	rtm = nlmsg_data(nlh);
2346 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2347 	rtm->rtm_dst_len  = 32;
2348 	rtm->rtm_src_len  = 32;
2349 	rtm->rtm_tos      = 0;
2350 	rtm->rtm_table    = mrt->id;
2351 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2352 		goto nla_put_failure;
2353 	rtm->rtm_type     = RTN_MULTICAST;
2354 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2355 	if (c->_c.mfc_flags & MFC_STATIC)
2356 		rtm->rtm_protocol = RTPROT_STATIC;
2357 	else
2358 		rtm->rtm_protocol = RTPROT_MROUTED;
2359 	rtm->rtm_flags    = 0;
2360 
2361 	if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
2362 	    nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
2363 		goto nla_put_failure;
2364 	err = mr_fill_mroute(mrt, skb, &c->_c, rtm);
2365 	/* do not break the dump if cache is unresolved */
2366 	if (err < 0 && err != -ENOENT)
2367 		goto nla_put_failure;
2368 
2369 	nlmsg_end(skb, nlh);
2370 	return 0;
2371 
2372 nla_put_failure:
2373 	nlmsg_cancel(skb, nlh);
2374 	return -EMSGSIZE;
2375 }
2376 
2377 static int _ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2378 			     u32 portid, u32 seq, struct mr_mfc *c, int cmd,
2379 			     int flags)
2380 {
2381 	return ipmr_fill_mroute(mrt, skb, portid, seq, (struct mfc_cache *)c,
2382 				cmd, flags);
2383 }
2384 
2385 static size_t mroute_msgsize(bool unresolved, int maxvif)
2386 {
2387 	size_t len =
2388 		NLMSG_ALIGN(sizeof(struct rtmsg))
2389 		+ nla_total_size(4)	/* RTA_TABLE */
2390 		+ nla_total_size(4)	/* RTA_SRC */
2391 		+ nla_total_size(4)	/* RTA_DST */
2392 		;
2393 
2394 	if (!unresolved)
2395 		len = len
2396 		      + nla_total_size(4)	/* RTA_IIF */
2397 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2398 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2399 						/* RTA_MFC_STATS */
2400 		      + nla_total_size_64bit(sizeof(struct rta_mfc_stats))
2401 		;
2402 
2403 	return len;
2404 }
2405 
2406 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2407 				 int cmd)
2408 {
2409 	struct net *net = read_pnet(&mrt->net);
2410 	struct sk_buff *skb;
2411 	int err = -ENOBUFS;
2412 
2413 	skb = nlmsg_new(mroute_msgsize(mfc->_c.mfc_parent >= MAXVIFS,
2414 				       mrt->maxvif),
2415 			GFP_ATOMIC);
2416 	if (!skb)
2417 		goto errout;
2418 
2419 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2420 	if (err < 0)
2421 		goto errout;
2422 
2423 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2424 	return;
2425 
2426 errout:
2427 	kfree_skb(skb);
2428 	rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2429 }
2430 
2431 static size_t igmpmsg_netlink_msgsize(size_t payloadlen)
2432 {
2433 	size_t len =
2434 		NLMSG_ALIGN(sizeof(struct rtgenmsg))
2435 		+ nla_total_size(1)	/* IPMRA_CREPORT_MSGTYPE */
2436 		+ nla_total_size(4)	/* IPMRA_CREPORT_VIF_ID */
2437 		+ nla_total_size(4)	/* IPMRA_CREPORT_SRC_ADDR */
2438 		+ nla_total_size(4)	/* IPMRA_CREPORT_DST_ADDR */
2439 		+ nla_total_size(4)	/* IPMRA_CREPORT_TABLE */
2440 					/* IPMRA_CREPORT_PKT */
2441 		+ nla_total_size(payloadlen)
2442 		;
2443 
2444 	return len;
2445 }
2446 
2447 static void igmpmsg_netlink_event(const struct mr_table *mrt, struct sk_buff *pkt)
2448 {
2449 	struct net *net = read_pnet(&mrt->net);
2450 	struct nlmsghdr *nlh;
2451 	struct rtgenmsg *rtgenm;
2452 	struct igmpmsg *msg;
2453 	struct sk_buff *skb;
2454 	struct nlattr *nla;
2455 	int payloadlen;
2456 
2457 	payloadlen = pkt->len - sizeof(struct igmpmsg);
2458 	msg = (struct igmpmsg *)skb_network_header(pkt);
2459 
2460 	skb = nlmsg_new(igmpmsg_netlink_msgsize(payloadlen), GFP_ATOMIC);
2461 	if (!skb)
2462 		goto errout;
2463 
2464 	nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT,
2465 			sizeof(struct rtgenmsg), 0);
2466 	if (!nlh)
2467 		goto errout;
2468 	rtgenm = nlmsg_data(nlh);
2469 	rtgenm->rtgen_family = RTNL_FAMILY_IPMR;
2470 	if (nla_put_u8(skb, IPMRA_CREPORT_MSGTYPE, msg->im_msgtype) ||
2471 	    nla_put_u32(skb, IPMRA_CREPORT_VIF_ID, msg->im_vif | (msg->im_vif_hi << 8)) ||
2472 	    nla_put_in_addr(skb, IPMRA_CREPORT_SRC_ADDR,
2473 			    msg->im_src.s_addr) ||
2474 	    nla_put_in_addr(skb, IPMRA_CREPORT_DST_ADDR,
2475 			    msg->im_dst.s_addr) ||
2476 	    nla_put_u32(skb, IPMRA_CREPORT_TABLE, mrt->id))
2477 		goto nla_put_failure;
2478 
2479 	nla = nla_reserve(skb, IPMRA_CREPORT_PKT, payloadlen);
2480 	if (!nla || skb_copy_bits(pkt, sizeof(struct igmpmsg),
2481 				  nla_data(nla), payloadlen))
2482 		goto nla_put_failure;
2483 
2484 	nlmsg_end(skb, nlh);
2485 
2486 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE_R, NULL, GFP_ATOMIC);
2487 	return;
2488 
2489 nla_put_failure:
2490 	nlmsg_cancel(skb, nlh);
2491 errout:
2492 	kfree_skb(skb);
2493 	rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE_R, -ENOBUFS);
2494 }
2495 
2496 static int ipmr_rtm_valid_getroute_req(struct sk_buff *skb,
2497 				       const struct nlmsghdr *nlh,
2498 				       struct nlattr **tb,
2499 				       struct netlink_ext_ack *extack)
2500 {
2501 	struct rtmsg *rtm;
2502 	int i, err;
2503 
2504 	rtm = nlmsg_payload(nlh, sizeof(*rtm));
2505 	if (!rtm) {
2506 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for multicast route get request");
2507 		return -EINVAL;
2508 	}
2509 
2510 	if (!netlink_strict_get_check(skb))
2511 		return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
2512 					      rtm_ipv4_policy, extack);
2513 
2514 	if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
2515 	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
2516 	    rtm->rtm_tos || rtm->rtm_table || rtm->rtm_protocol ||
2517 	    rtm->rtm_scope || rtm->rtm_type || rtm->rtm_flags) {
2518 		NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for multicast route get request");
2519 		return -EINVAL;
2520 	}
2521 
2522 	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2523 					    rtm_ipv4_policy, extack);
2524 	if (err)
2525 		return err;
2526 
2527 	if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
2528 	    (tb[RTA_DST] && !rtm->rtm_dst_len)) {
2529 		NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
2530 		return -EINVAL;
2531 	}
2532 
2533 	for (i = 0; i <= RTA_MAX; i++) {
2534 		if (!tb[i])
2535 			continue;
2536 
2537 		switch (i) {
2538 		case RTA_SRC:
2539 		case RTA_DST:
2540 		case RTA_TABLE:
2541 			break;
2542 		default:
2543 			NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in multicast route get request");
2544 			return -EINVAL;
2545 		}
2546 	}
2547 
2548 	return 0;
2549 }
2550 
2551 static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2552 			     struct netlink_ext_ack *extack)
2553 {
2554 	struct net *net = sock_net(in_skb->sk);
2555 	struct nlattr *tb[RTA_MAX + 1];
2556 	struct sk_buff *skb = NULL;
2557 	struct mfc_cache *cache;
2558 	struct mr_table *mrt;
2559 	__be32 src, grp;
2560 	u32 tableid;
2561 	int err;
2562 
2563 	err = ipmr_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
2564 	if (err < 0)
2565 		goto errout;
2566 
2567 	src = nla_get_in_addr_default(tb[RTA_SRC], 0);
2568 	grp = nla_get_in_addr_default(tb[RTA_DST], 0);
2569 	tableid = nla_get_u32_default(tb[RTA_TABLE], 0);
2570 
2571 	mrt = __ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT);
2572 	if (!mrt) {
2573 		err = -ENOENT;
2574 		goto errout_free;
2575 	}
2576 
2577 	/* entries are added/deleted only under RTNL */
2578 	rcu_read_lock();
2579 	cache = ipmr_cache_find(mrt, src, grp);
2580 	rcu_read_unlock();
2581 	if (!cache) {
2582 		err = -ENOENT;
2583 		goto errout_free;
2584 	}
2585 
2586 	skb = nlmsg_new(mroute_msgsize(false, mrt->maxvif), GFP_KERNEL);
2587 	if (!skb) {
2588 		err = -ENOBUFS;
2589 		goto errout_free;
2590 	}
2591 
2592 	err = ipmr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid,
2593 			       nlh->nlmsg_seq, cache,
2594 			       RTM_NEWROUTE, 0);
2595 	if (err < 0)
2596 		goto errout_free;
2597 
2598 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2599 
2600 errout:
2601 	return err;
2602 
2603 errout_free:
2604 	kfree_skb(skb);
2605 	goto errout;
2606 }
2607 
2608 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2609 {
2610 	struct fib_dump_filter filter = {
2611 		.rtnl_held = true,
2612 	};
2613 	int err;
2614 
2615 	if (cb->strict_check) {
2616 		err = ip_valid_fib_dump_req(sock_net(skb->sk), cb->nlh,
2617 					    &filter, cb);
2618 		if (err < 0)
2619 			return err;
2620 	}
2621 
2622 	if (filter.table_id) {
2623 		struct mr_table *mrt;
2624 
2625 		mrt = __ipmr_get_table(sock_net(skb->sk), filter.table_id);
2626 		if (!mrt) {
2627 			if (rtnl_msg_family(cb->nlh) != RTNL_FAMILY_IPMR)
2628 				return skb->len;
2629 
2630 			NL_SET_ERR_MSG(cb->extack, "ipv4: MR table does not exist");
2631 			return -ENOENT;
2632 		}
2633 		err = mr_table_dump(mrt, skb, cb, _ipmr_fill_mroute,
2634 				    &mfc_unres_lock, &filter);
2635 		return skb->len ? : err;
2636 	}
2637 
2638 	return mr_rtm_dumproute(skb, cb, ipmr_mr_table_iter,
2639 				_ipmr_fill_mroute, &mfc_unres_lock, &filter);
2640 }
2641 
2642 static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {
2643 	[RTA_SRC]	= { .type = NLA_U32 },
2644 	[RTA_DST]	= { .type = NLA_U32 },
2645 	[RTA_IIF]	= { .type = NLA_U32 },
2646 	[RTA_TABLE]	= { .type = NLA_U32 },
2647 	[RTA_MULTIPATH]	= { .len = sizeof(struct rtnexthop) },
2648 };
2649 
2650 static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol)
2651 {
2652 	switch (rtm_protocol) {
2653 	case RTPROT_STATIC:
2654 	case RTPROT_MROUTED:
2655 		return true;
2656 	}
2657 	return false;
2658 }
2659 
2660 static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc)
2661 {
2662 	struct rtnexthop *rtnh = nla_data(nla);
2663 	int remaining = nla_len(nla), vifi = 0;
2664 
2665 	while (rtnh_ok(rtnh, remaining)) {
2666 		mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops;
2667 		if (++vifi == MAXVIFS)
2668 			break;
2669 		rtnh = rtnh_next(rtnh, &remaining);
2670 	}
2671 
2672 	return remaining > 0 ? -EINVAL : vifi;
2673 }
2674 
2675 /* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */
2676 static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
2677 			    struct mfcctl *mfcc, int *mrtsock,
2678 			    struct mr_table **mrtret,
2679 			    struct netlink_ext_ack *extack)
2680 {
2681 	struct net_device *dev = NULL;
2682 	u32 tblid = RT_TABLE_DEFAULT;
2683 	struct mr_table *mrt;
2684 	struct nlattr *attr;
2685 	struct rtmsg *rtm;
2686 	int ret, rem;
2687 
2688 	ret = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
2689 					rtm_ipmr_policy, extack);
2690 	if (ret < 0)
2691 		goto out;
2692 	rtm = nlmsg_data(nlh);
2693 
2694 	ret = -EINVAL;
2695 	if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 ||
2696 	    rtm->rtm_type != RTN_MULTICAST ||
2697 	    rtm->rtm_scope != RT_SCOPE_UNIVERSE ||
2698 	    !ipmr_rtm_validate_proto(rtm->rtm_protocol))
2699 		goto out;
2700 
2701 	memset(mfcc, 0, sizeof(*mfcc));
2702 	mfcc->mfcc_parent = -1;
2703 	ret = 0;
2704 	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) {
2705 		switch (nla_type(attr)) {
2706 		case RTA_SRC:
2707 			mfcc->mfcc_origin.s_addr = nla_get_be32(attr);
2708 			break;
2709 		case RTA_DST:
2710 			mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr);
2711 			break;
2712 		case RTA_IIF:
2713 			dev = __dev_get_by_index(net, nla_get_u32(attr));
2714 			if (!dev) {
2715 				ret = -ENODEV;
2716 				goto out;
2717 			}
2718 			break;
2719 		case RTA_MULTIPATH:
2720 			if (ipmr_nla_get_ttls(attr, mfcc) < 0) {
2721 				ret = -EINVAL;
2722 				goto out;
2723 			}
2724 			break;
2725 		case RTA_PREFSRC:
2726 			ret = 1;
2727 			break;
2728 		case RTA_TABLE:
2729 			tblid = nla_get_u32(attr);
2730 			break;
2731 		}
2732 	}
2733 	mrt = __ipmr_get_table(net, tblid);
2734 	if (!mrt) {
2735 		ret = -ENOENT;
2736 		goto out;
2737 	}
2738 	*mrtret = mrt;
2739 	*mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0;
2740 	if (dev)
2741 		mfcc->mfcc_parent = ipmr_find_vif(mrt, dev);
2742 
2743 out:
2744 	return ret;
2745 }
2746 
2747 /* takes care of both newroute and delroute */
2748 static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh,
2749 			  struct netlink_ext_ack *extack)
2750 {
2751 	struct net *net = sock_net(skb->sk);
2752 	int ret, mrtsock, parent;
2753 	struct mr_table *tbl;
2754 	struct mfcctl mfcc;
2755 
2756 	mrtsock = 0;
2757 	tbl = NULL;
2758 	ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl, extack);
2759 	if (ret < 0)
2760 		return ret;
2761 
2762 	parent = ret ? mfcc.mfcc_parent : -1;
2763 	if (nlh->nlmsg_type == RTM_NEWROUTE)
2764 		return ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent);
2765 	else
2766 		return ipmr_mfc_delete(tbl, &mfcc, parent);
2767 }
2768 
2769 static bool ipmr_fill_table(struct mr_table *mrt, struct sk_buff *skb)
2770 {
2771 	u32 queue_len = atomic_read(&mrt->cache_resolve_queue_len);
2772 
2773 	if (nla_put_u32(skb, IPMRA_TABLE_ID, mrt->id) ||
2774 	    nla_put_u32(skb, IPMRA_TABLE_CACHE_RES_QUEUE_LEN, queue_len) ||
2775 	    nla_put_s32(skb, IPMRA_TABLE_MROUTE_REG_VIF_NUM,
2776 			mrt->mroute_reg_vif_num) ||
2777 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_ASSERT,
2778 		       mrt->mroute_do_assert) ||
2779 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_PIM, mrt->mroute_do_pim) ||
2780 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_WRVIFWHOLE,
2781 		       mrt->mroute_do_wrvifwhole))
2782 		return false;
2783 
2784 	return true;
2785 }
2786 
2787 static bool ipmr_fill_vif(struct mr_table *mrt, u32 vifid, struct sk_buff *skb)
2788 {
2789 	struct net_device *vif_dev;
2790 	struct nlattr *vif_nest;
2791 	struct vif_device *vif;
2792 
2793 	vif = &mrt->vif_table[vifid];
2794 	vif_dev = rtnl_dereference(vif->dev);
2795 	/* if the VIF doesn't exist just continue */
2796 	if (!vif_dev)
2797 		return true;
2798 
2799 	vif_nest = nla_nest_start_noflag(skb, IPMRA_VIF);
2800 	if (!vif_nest)
2801 		return false;
2802 
2803 	if (nla_put_u32(skb, IPMRA_VIFA_IFINDEX, vif_dev->ifindex) ||
2804 	    nla_put_u32(skb, IPMRA_VIFA_VIF_ID, vifid) ||
2805 	    nla_put_u16(skb, IPMRA_VIFA_FLAGS, vif->flags) ||
2806 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_IN, vif->bytes_in,
2807 			      IPMRA_VIFA_PAD) ||
2808 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_OUT, vif->bytes_out,
2809 			      IPMRA_VIFA_PAD) ||
2810 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_IN, vif->pkt_in,
2811 			      IPMRA_VIFA_PAD) ||
2812 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_OUT, vif->pkt_out,
2813 			      IPMRA_VIFA_PAD) ||
2814 	    nla_put_be32(skb, IPMRA_VIFA_LOCAL_ADDR, vif->local) ||
2815 	    nla_put_be32(skb, IPMRA_VIFA_REMOTE_ADDR, vif->remote)) {
2816 		nla_nest_cancel(skb, vif_nest);
2817 		return false;
2818 	}
2819 	nla_nest_end(skb, vif_nest);
2820 
2821 	return true;
2822 }
2823 
2824 static int ipmr_valid_dumplink(const struct nlmsghdr *nlh,
2825 			       struct netlink_ext_ack *extack)
2826 {
2827 	struct ifinfomsg *ifm;
2828 
2829 	ifm = nlmsg_payload(nlh, sizeof(*ifm));
2830 	if (!ifm) {
2831 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for ipmr link dump");
2832 		return -EINVAL;
2833 	}
2834 
2835 	if (nlmsg_attrlen(nlh, sizeof(*ifm))) {
2836 		NL_SET_ERR_MSG(extack, "Invalid data after header in ipmr link dump");
2837 		return -EINVAL;
2838 	}
2839 
2840 	if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags ||
2841 	    ifm->ifi_change || ifm->ifi_index) {
2842 		NL_SET_ERR_MSG(extack, "Invalid values in header for ipmr link dump request");
2843 		return -EINVAL;
2844 	}
2845 
2846 	return 0;
2847 }
2848 
2849 static int ipmr_rtm_dumplink(struct sk_buff *skb, struct netlink_callback *cb)
2850 {
2851 	struct net *net = sock_net(skb->sk);
2852 	struct nlmsghdr *nlh = NULL;
2853 	unsigned int t = 0, s_t;
2854 	unsigned int e = 0, s_e;
2855 	struct mr_table *mrt;
2856 
2857 	if (cb->strict_check) {
2858 		int err = ipmr_valid_dumplink(cb->nlh, cb->extack);
2859 
2860 		if (err < 0)
2861 			return err;
2862 	}
2863 
2864 	s_t = cb->args[0];
2865 	s_e = cb->args[1];
2866 
2867 	ipmr_for_each_table(mrt, net) {
2868 		struct nlattr *vifs, *af;
2869 		struct ifinfomsg *hdr;
2870 		u32 i;
2871 
2872 		if (t < s_t)
2873 			goto skip_table;
2874 		nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
2875 				cb->nlh->nlmsg_seq, RTM_NEWLINK,
2876 				sizeof(*hdr), NLM_F_MULTI);
2877 		if (!nlh)
2878 			break;
2879 
2880 		hdr = nlmsg_data(nlh);
2881 		memset(hdr, 0, sizeof(*hdr));
2882 		hdr->ifi_family = RTNL_FAMILY_IPMR;
2883 
2884 		af = nla_nest_start_noflag(skb, IFLA_AF_SPEC);
2885 		if (!af) {
2886 			nlmsg_cancel(skb, nlh);
2887 			goto out;
2888 		}
2889 
2890 		if (!ipmr_fill_table(mrt, skb)) {
2891 			nlmsg_cancel(skb, nlh);
2892 			goto out;
2893 		}
2894 
2895 		vifs = nla_nest_start_noflag(skb, IPMRA_TABLE_VIFS);
2896 		if (!vifs) {
2897 			nla_nest_end(skb, af);
2898 			nlmsg_end(skb, nlh);
2899 			goto out;
2900 		}
2901 		for (i = 0; i < mrt->maxvif; i++) {
2902 			if (e < s_e)
2903 				goto skip_entry;
2904 			if (!ipmr_fill_vif(mrt, i, skb)) {
2905 				nla_nest_end(skb, vifs);
2906 				nla_nest_end(skb, af);
2907 				nlmsg_end(skb, nlh);
2908 				goto out;
2909 			}
2910 skip_entry:
2911 			e++;
2912 		}
2913 		s_e = 0;
2914 		e = 0;
2915 		nla_nest_end(skb, vifs);
2916 		nla_nest_end(skb, af);
2917 		nlmsg_end(skb, nlh);
2918 skip_table:
2919 		t++;
2920 	}
2921 
2922 out:
2923 	cb->args[1] = e;
2924 	cb->args[0] = t;
2925 
2926 	return skb->len;
2927 }
2928 
2929 #ifdef CONFIG_PROC_FS
2930 /* The /proc interfaces to multicast routing :
2931  * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2932  */
2933 
2934 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2935 	__acquires(RCU)
2936 {
2937 	struct mr_vif_iter *iter = seq->private;
2938 	struct net *net = seq_file_net(seq);
2939 	struct mr_table *mrt;
2940 
2941 	rcu_read_lock();
2942 	mrt = __ipmr_get_table(net, RT_TABLE_DEFAULT);
2943 	if (!mrt) {
2944 		rcu_read_unlock();
2945 		return ERR_PTR(-ENOENT);
2946 	}
2947 
2948 	iter->mrt = mrt;
2949 
2950 	return mr_vif_seq_start(seq, pos);
2951 }
2952 
2953 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2954 	__releases(RCU)
2955 {
2956 	rcu_read_unlock();
2957 }
2958 
2959 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2960 {
2961 	struct mr_vif_iter *iter = seq->private;
2962 	struct mr_table *mrt = iter->mrt;
2963 
2964 	if (v == SEQ_START_TOKEN) {
2965 		seq_puts(seq,
2966 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2967 	} else {
2968 		const struct vif_device *vif = v;
2969 		const struct net_device *vif_dev;
2970 		const char *name;
2971 
2972 		vif_dev = vif_dev_read(vif);
2973 		name = vif_dev ? vif_dev->name : "none";
2974 		seq_printf(seq,
2975 			   "%2td %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2976 			   vif - mrt->vif_table,
2977 			   name, vif->bytes_in, vif->pkt_in,
2978 			   vif->bytes_out, vif->pkt_out,
2979 			   vif->flags, vif->local, vif->remote);
2980 	}
2981 	return 0;
2982 }
2983 
2984 static const struct seq_operations ipmr_vif_seq_ops = {
2985 	.start = ipmr_vif_seq_start,
2986 	.next  = mr_vif_seq_next,
2987 	.stop  = ipmr_vif_seq_stop,
2988 	.show  = ipmr_vif_seq_show,
2989 };
2990 
2991 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2992 {
2993 	struct net *net = seq_file_net(seq);
2994 	struct mr_table *mrt;
2995 
2996 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2997 	if (!mrt)
2998 		return ERR_PTR(-ENOENT);
2999 
3000 	return mr_mfc_seq_start(seq, pos, mrt, &mfc_unres_lock);
3001 }
3002 
3003 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
3004 {
3005 	int n;
3006 
3007 	if (v == SEQ_START_TOKEN) {
3008 		seq_puts(seq,
3009 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
3010 	} else {
3011 		const struct mfc_cache *mfc = v;
3012 		const struct mr_mfc_iter *it = seq->private;
3013 		const struct mr_table *mrt = it->mrt;
3014 
3015 		seq_printf(seq, "%08X %08X %-3hd",
3016 			   (__force u32) mfc->mfc_mcastgrp,
3017 			   (__force u32) mfc->mfc_origin,
3018 			   mfc->_c.mfc_parent);
3019 
3020 		if (it->cache != &mrt->mfc_unres_queue) {
3021 			seq_printf(seq, " %8lu %8lu %8lu",
3022 				   atomic_long_read(&mfc->_c.mfc_un.res.pkt),
3023 				   atomic_long_read(&mfc->_c.mfc_un.res.bytes),
3024 				   atomic_long_read(&mfc->_c.mfc_un.res.wrong_if));
3025 			for (n = mfc->_c.mfc_un.res.minvif;
3026 			     n < mfc->_c.mfc_un.res.maxvif; n++) {
3027 				if (VIF_EXISTS(mrt, n) &&
3028 				    mfc->_c.mfc_un.res.ttls[n] < 255)
3029 					seq_printf(seq,
3030 					   " %2d:%-3d",
3031 					   n, mfc->_c.mfc_un.res.ttls[n]);
3032 			}
3033 		} else {
3034 			/* unresolved mfc_caches don't contain
3035 			 * pkt, bytes and wrong_if values
3036 			 */
3037 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
3038 		}
3039 		seq_putc(seq, '\n');
3040 	}
3041 	return 0;
3042 }
3043 
3044 static const struct seq_operations ipmr_mfc_seq_ops = {
3045 	.start = ipmr_mfc_seq_start,
3046 	.next  = mr_mfc_seq_next,
3047 	.stop  = mr_mfc_seq_stop,
3048 	.show  = ipmr_mfc_seq_show,
3049 };
3050 #endif
3051 
3052 #ifdef CONFIG_IP_PIMSM_V2
3053 static const struct net_protocol pim_protocol = {
3054 	.handler	=	pim_rcv,
3055 };
3056 #endif
3057 
3058 static unsigned int ipmr_seq_read(const struct net *net)
3059 {
3060 	return READ_ONCE(net->ipv4.ipmr_seq) + ipmr_rules_seq_read(net);
3061 }
3062 
3063 static int ipmr_dump(struct net *net, struct notifier_block *nb,
3064 		     struct netlink_ext_ack *extack)
3065 {
3066 	return mr_dump(net, nb, RTNL_FAMILY_IPMR, ipmr_rules_dump,
3067 		       ipmr_mr_table_iter, extack);
3068 }
3069 
3070 static const struct fib_notifier_ops ipmr_notifier_ops_template = {
3071 	.family		= RTNL_FAMILY_IPMR,
3072 	.fib_seq_read	= ipmr_seq_read,
3073 	.fib_dump	= ipmr_dump,
3074 	.owner		= THIS_MODULE,
3075 };
3076 
3077 static int __net_init ipmr_notifier_init(struct net *net)
3078 {
3079 	struct fib_notifier_ops *ops;
3080 
3081 	net->ipv4.ipmr_seq = 0;
3082 
3083 	ops = fib_notifier_ops_register(&ipmr_notifier_ops_template, net);
3084 	if (IS_ERR(ops))
3085 		return PTR_ERR(ops);
3086 	net->ipv4.ipmr_notifier_ops = ops;
3087 
3088 	return 0;
3089 }
3090 
3091 static void __net_exit ipmr_notifier_exit(struct net *net)
3092 {
3093 	fib_notifier_ops_unregister(net->ipv4.ipmr_notifier_ops);
3094 	net->ipv4.ipmr_notifier_ops = NULL;
3095 }
3096 
3097 /* Setup for IP multicast routing */
3098 static int __net_init ipmr_net_init(struct net *net)
3099 {
3100 	int err;
3101 
3102 	err = ipmr_notifier_init(net);
3103 	if (err)
3104 		goto ipmr_notifier_fail;
3105 
3106 	err = ipmr_rules_init(net);
3107 	if (err < 0)
3108 		goto ipmr_rules_fail;
3109 
3110 #ifdef CONFIG_PROC_FS
3111 	err = -ENOMEM;
3112 	if (!proc_create_net("ip_mr_vif", 0, net->proc_net, &ipmr_vif_seq_ops,
3113 			sizeof(struct mr_vif_iter)))
3114 		goto proc_vif_fail;
3115 	if (!proc_create_net("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_seq_ops,
3116 			sizeof(struct mr_mfc_iter)))
3117 		goto proc_cache_fail;
3118 #endif
3119 	return 0;
3120 
3121 #ifdef CONFIG_PROC_FS
3122 proc_cache_fail:
3123 	remove_proc_entry("ip_mr_vif", net->proc_net);
3124 proc_vif_fail:
3125 	rtnl_lock();
3126 	ipmr_rules_exit(net);
3127 	rtnl_unlock();
3128 #endif
3129 ipmr_rules_fail:
3130 	ipmr_notifier_exit(net);
3131 ipmr_notifier_fail:
3132 	return err;
3133 }
3134 
3135 static void __net_exit ipmr_net_exit(struct net *net)
3136 {
3137 #ifdef CONFIG_PROC_FS
3138 	remove_proc_entry("ip_mr_cache", net->proc_net);
3139 	remove_proc_entry("ip_mr_vif", net->proc_net);
3140 #endif
3141 	ipmr_notifier_exit(net);
3142 }
3143 
3144 static void __net_exit ipmr_net_exit_batch(struct list_head *net_list)
3145 {
3146 	struct net *net;
3147 
3148 	rtnl_lock();
3149 	list_for_each_entry(net, net_list, exit_list)
3150 		ipmr_rules_exit(net);
3151 	rtnl_unlock();
3152 }
3153 
3154 static struct pernet_operations ipmr_net_ops = {
3155 	.init = ipmr_net_init,
3156 	.exit = ipmr_net_exit,
3157 	.exit_batch = ipmr_net_exit_batch,
3158 };
3159 
3160 static const struct rtnl_msg_handler ipmr_rtnl_msg_handlers[] __initconst = {
3161 	{.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_GETLINK,
3162 	 .dumpit = ipmr_rtm_dumplink},
3163 	{.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_NEWROUTE,
3164 	 .doit = ipmr_rtm_route},
3165 	{.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_DELROUTE,
3166 	 .doit = ipmr_rtm_route},
3167 	{.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_GETROUTE,
3168 	 .doit = ipmr_rtm_getroute, .dumpit = ipmr_rtm_dumproute},
3169 };
3170 
3171 int __init ip_mr_init(void)
3172 {
3173 	int err;
3174 
3175 	mrt_cachep = KMEM_CACHE(mfc_cache, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
3176 
3177 	err = register_pernet_subsys(&ipmr_net_ops);
3178 	if (err)
3179 		goto reg_pernet_fail;
3180 
3181 	err = register_netdevice_notifier(&ip_mr_notifier);
3182 	if (err)
3183 		goto reg_notif_fail;
3184 #ifdef CONFIG_IP_PIMSM_V2
3185 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
3186 		pr_err("%s: can't add PIM protocol\n", __func__);
3187 		err = -EAGAIN;
3188 		goto add_proto_fail;
3189 	}
3190 #endif
3191 	rtnl_register_many(ipmr_rtnl_msg_handlers);
3192 
3193 	return 0;
3194 
3195 #ifdef CONFIG_IP_PIMSM_V2
3196 add_proto_fail:
3197 	unregister_netdevice_notifier(&ip_mr_notifier);
3198 #endif
3199 reg_notif_fail:
3200 	unregister_pernet_subsys(&ipmr_net_ops);
3201 reg_pernet_fail:
3202 	kmem_cache_destroy(mrt_cachep);
3203 	return err;
3204 }
3205