xref: /linux/net/ipv4/ipmr.c (revision 30cb24f97d44f6b81c14b85c5323de62eef1fb7f)
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/flow.h>
46 #include <net/net_namespace.h>
47 #include <net/ip.h>
48 #include <net/protocol.h>
49 #include <linux/skbuff.h>
50 #include <net/route.h>
51 #include <net/icmp.h>
52 #include <net/udp.h>
53 #include <net/raw.h>
54 #include <linux/notifier.h>
55 #include <linux/if_arp.h>
56 #include <linux/netfilter_ipv4.h>
57 #include <linux/compat.h>
58 #include <linux/export.h>
59 #include <linux/rhashtable.h>
60 #include <net/ip_tunnels.h>
61 #include <net/checksum.h>
62 #include <net/netlink.h>
63 #include <net/fib_rules.h>
64 #include <linux/netconf.h>
65 #include <net/rtnh.h>
66 #include <net/inet_dscp.h>
67 
68 #include <linux/nospec.h>
69 
70 struct ipmr_rule {
71 	struct fib_rule		common;
72 };
73 
74 struct ipmr_result {
75 	struct mr_table		*mrt;
76 };
77 
78 /* Big lock, protecting vif table, mrt cache and mroute socket state.
79  * Note that the changes are semaphored via rtnl_lock.
80  */
81 
82 static DEFINE_SPINLOCK(mrt_lock);
83 
84 static struct net_device *vif_dev_read(const struct vif_device *vif)
85 {
86 	return rcu_dereference(vif->dev);
87 }
88 
89 /* Multicast router control variables */
90 
91 /* Special spinlock for queue of unresolved entries */
92 static DEFINE_SPINLOCK(mfc_unres_lock);
93 
94 /* We return to original Alan's scheme. Hash table of resolved
95  * entries is changed only in process context and protected
96  * with weak lock mrt_lock. Queue of unresolved entries is protected
97  * with strong spinlock mfc_unres_lock.
98  *
99  * In this case data path is free of exclusive locks at all.
100  */
101 
102 static struct kmem_cache *mrt_cachep __ro_after_init;
103 
104 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
105 static void ipmr_free_table(struct mr_table *mrt,
106 			    struct list_head *dev_kill_list);
107 
108 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
109 			  struct net_device *dev, struct sk_buff *skb,
110 			  struct mfc_cache *cache, int local);
111 static int ipmr_cache_report(const struct mr_table *mrt,
112 			     struct sk_buff *pkt, vifi_t vifi, int assert);
113 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
114 				 int cmd);
115 static void igmpmsg_netlink_event(const struct mr_table *mrt, struct sk_buff *pkt);
116 static void mroute_clean_tables(struct mr_table *mrt, int flags,
117 				struct list_head *dev_kill_list);
118 static void ipmr_expire_process(struct timer_list *t);
119 
120 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
121 #define ipmr_for_each_table(mrt, net)					\
122 	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list,	\
123 				lockdep_rtnl_is_held() ||		\
124 				list_empty(&net->ipv4.mr_tables))
125 
126 static struct mr_table *ipmr_mr_table_iter(struct net *net,
127 					   struct mr_table *mrt)
128 {
129 	struct mr_table *ret;
130 
131 	if (!mrt)
132 		ret = list_entry_rcu(net->ipv4.mr_tables.next,
133 				     struct mr_table, list);
134 	else
135 		ret = list_entry_rcu(mrt->list.next,
136 				     struct mr_table, list);
137 
138 	if (&ret->list == &net->ipv4.mr_tables)
139 		return NULL;
140 	return ret;
141 }
142 
143 static struct mr_table *__ipmr_get_table(struct net *net, u32 id)
144 {
145 	struct mr_table *mrt;
146 
147 	ipmr_for_each_table(mrt, net) {
148 		if (mrt->id == id)
149 			return mrt;
150 	}
151 	return NULL;
152 }
153 
154 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
155 			   struct mr_table **mrt)
156 {
157 	int err;
158 	struct ipmr_result res;
159 	struct fib_lookup_arg arg = {
160 		.result = &res,
161 		.flags = FIB_LOOKUP_NOREF,
162 	};
163 
164 	/* update flow if oif or iif point to device enslaved to l3mdev */
165 	l3mdev_update_flow(net, flowi4_to_flowi(flp4));
166 
167 	err = fib_rules_lookup(net->ipv4.mr_rules_ops,
168 			       flowi4_to_flowi(flp4), 0, &arg);
169 	if (err < 0)
170 		return err;
171 	*mrt = res.mrt;
172 	return 0;
173 }
174 
175 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
176 			    int flags, struct fib_lookup_arg *arg)
177 {
178 	struct ipmr_result *res = arg->result;
179 	struct mr_table *mrt;
180 
181 	switch (rule->action) {
182 	case FR_ACT_TO_TBL:
183 		break;
184 	case FR_ACT_UNREACHABLE:
185 		return -ENETUNREACH;
186 	case FR_ACT_PROHIBIT:
187 		return -EACCES;
188 	case FR_ACT_BLACKHOLE:
189 	default:
190 		return -EINVAL;
191 	}
192 
193 	arg->table = fib_rule_get_table(rule, arg);
194 
195 	mrt = __ipmr_get_table(rule->fr_net, arg->table);
196 	if (!mrt)
197 		return -EAGAIN;
198 	res->mrt = mrt;
199 	return 0;
200 }
201 
202 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
203 {
204 	return 1;
205 }
206 
207 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
208 			       struct fib_rule_hdr *frh, struct nlattr **tb,
209 			       struct netlink_ext_ack *extack)
210 {
211 	return 0;
212 }
213 
214 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
215 			     struct nlattr **tb)
216 {
217 	return 1;
218 }
219 
220 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
221 			  struct fib_rule_hdr *frh)
222 {
223 	frh->dst_len = 0;
224 	frh->src_len = 0;
225 	frh->tos     = 0;
226 	return 0;
227 }
228 
229 static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
230 	.family		= RTNL_FAMILY_IPMR,
231 	.rule_size	= sizeof(struct ipmr_rule),
232 	.addr_size	= sizeof(u32),
233 	.action		= ipmr_rule_action,
234 	.match		= ipmr_rule_match,
235 	.configure	= ipmr_rule_configure,
236 	.compare	= ipmr_rule_compare,
237 	.fill		= ipmr_rule_fill,
238 	.nlgroup	= RTNLGRP_IPV4_RULE,
239 	.owner		= THIS_MODULE,
240 };
241 
242 static int __net_init ipmr_rules_init(struct net *net)
243 {
244 	struct fib_rules_ops *ops;
245 	LIST_HEAD(dev_kill_list);
246 	struct mr_table *mrt;
247 	int err;
248 
249 	ops = fib_rules_register(&ipmr_rules_ops_template, net);
250 	if (IS_ERR(ops))
251 		return PTR_ERR(ops);
252 
253 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
254 
255 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
256 	if (IS_ERR(mrt)) {
257 		err = PTR_ERR(mrt);
258 		goto err1;
259 	}
260 
261 	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT);
262 	if (err < 0)
263 		goto err2;
264 
265 	net->ipv4.mr_rules_ops = ops;
266 	return 0;
267 
268 err2:
269 	ipmr_free_table(mrt, &dev_kill_list);
270 err1:
271 	fib_rules_unregister(ops);
272 	return err;
273 }
274 
275 static void __net_exit ipmr_rules_exit(struct net *net)
276 {
277 	fib_rules_unregister(net->ipv4.mr_rules_ops);
278 }
279 
280 static void __net_exit ipmr_rules_exit_rtnl(struct net *net,
281 					    struct list_head *dev_kill_list)
282 {
283 	struct mr_table *mrt, *next;
284 
285 	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
286 		list_del_rcu(&mrt->list);
287 		ipmr_free_table(mrt, dev_kill_list);
288 	}
289 }
290 
291 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
292 			   struct netlink_ext_ack *extack)
293 {
294 	return fib_rules_dump(net, nb, RTNL_FAMILY_IPMR, extack);
295 }
296 
297 static unsigned int ipmr_rules_seq_read(const struct net *net)
298 {
299 	return fib_rules_seq_read(net, RTNL_FAMILY_IPMR);
300 }
301 
302 bool ipmr_rule_default(const struct fib_rule *rule)
303 {
304 	return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
305 }
306 EXPORT_SYMBOL(ipmr_rule_default);
307 #else
308 static struct mr_table *ipmr_mr_table_iter(struct net *net,
309 					   struct mr_table *mrt)
310 {
311 	if (!mrt)
312 		return rcu_dereference(net->ipv4.mrt);
313 	return NULL;
314 }
315 
316 static struct mr_table *__ipmr_get_table(struct net *net, u32 id)
317 {
318 	return rcu_dereference_check(net->ipv4.mrt,
319 				     lockdep_rtnl_is_held() ||
320 				     !rcu_access_pointer(net->ipv4.mrt));
321 }
322 
323 #define ipmr_for_each_table(mrt, net)				\
324 	for (mrt = __ipmr_get_table(net, 0); mrt; mrt = NULL)
325 
326 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
327 			   struct mr_table **mrt)
328 {
329 	*mrt = rcu_dereference(net->ipv4.mrt);
330 	if (!*mrt)
331 		return -EAGAIN;
332 	return 0;
333 }
334 
335 static int __net_init ipmr_rules_init(struct net *net)
336 {
337 	struct mr_table *mrt;
338 
339 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
340 	if (IS_ERR(mrt))
341 		return PTR_ERR(mrt);
342 
343 	rcu_assign_pointer(net->ipv4.mrt, mrt);
344 	return 0;
345 }
346 
347 static void __net_exit ipmr_rules_exit(struct net *net)
348 {
349 }
350 
351 static void __net_exit ipmr_rules_exit_rtnl(struct net *net,
352 					    struct list_head *dev_kill_list)
353 {
354 	struct mr_table *mrt = rcu_dereference_protected(net->ipv4.mrt, 1);
355 
356 	RCU_INIT_POINTER(net->ipv4.mrt, NULL);
357 	ipmr_free_table(mrt, dev_kill_list);
358 }
359 
360 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
361 			   struct netlink_ext_ack *extack)
362 {
363 	return 0;
364 }
365 
366 static unsigned int ipmr_rules_seq_read(const struct net *net)
367 {
368 	return 0;
369 }
370 
371 bool ipmr_rule_default(const struct fib_rule *rule)
372 {
373 	return true;
374 }
375 EXPORT_SYMBOL(ipmr_rule_default);
376 #endif
377 
378 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
379 {
380 	struct mr_table *mrt;
381 
382 	rcu_read_lock();
383 	mrt = __ipmr_get_table(net, id);
384 	rcu_read_unlock();
385 
386 	return mrt;
387 }
388 
389 static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
390 				const void *ptr)
391 {
392 	const struct mfc_cache_cmp_arg *cmparg = arg->key;
393 	const struct mfc_cache *c = ptr;
394 
395 	return cmparg->mfc_mcastgrp != c->mfc_mcastgrp ||
396 	       cmparg->mfc_origin != c->mfc_origin;
397 }
398 
399 static const struct rhashtable_params ipmr_rht_params = {
400 	.head_offset = offsetof(struct mr_mfc, mnode),
401 	.key_offset = offsetof(struct mfc_cache, cmparg),
402 	.key_len = sizeof(struct mfc_cache_cmp_arg),
403 	.nelem_hint = 3,
404 	.obj_cmpfn = ipmr_hash_cmp,
405 	.automatic_shrinking = true,
406 };
407 
408 static void ipmr_new_table_set(struct mr_table *mrt,
409 			       struct net *net)
410 {
411 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
412 	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
413 #endif
414 }
415 
416 static struct mfc_cache_cmp_arg ipmr_mr_table_ops_cmparg_any = {
417 	.mfc_mcastgrp = htonl(INADDR_ANY),
418 	.mfc_origin = htonl(INADDR_ANY),
419 };
420 
421 static struct mr_table_ops ipmr_mr_table_ops = {
422 	.rht_params = &ipmr_rht_params,
423 	.cmparg_any = &ipmr_mr_table_ops_cmparg_any,
424 };
425 
426 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
427 {
428 	struct mr_table *mrt;
429 
430 	/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
431 	if (id != RT_TABLE_DEFAULT && id >= 1000000000)
432 		return ERR_PTR(-EINVAL);
433 
434 	mrt = __ipmr_get_table(net, id);
435 	if (mrt)
436 		return mrt;
437 
438 	return mr_table_alloc(net, id, &ipmr_mr_table_ops,
439 			      ipmr_expire_process, ipmr_new_table_set);
440 }
441 
442 static void ipmr_free_table(struct mr_table *mrt, struct list_head *dev_kill_list)
443 {
444 	struct net *net = read_pnet(&mrt->net);
445 	LIST_HEAD(ipmr_dev_kill_list);
446 
447 	WARN_ON_ONCE(!mr_can_free_table(net));
448 
449 	mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC |
450 			    MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC,
451 			    &ipmr_dev_kill_list);
452 	timer_shutdown_sync(&mrt->ipmr_expire_timer);
453 	mr_table_free(mrt);
454 
455 	WARN_ON_ONCE(!net_initialized(net) && !list_empty(&ipmr_dev_kill_list));
456 	list_splice(&ipmr_dev_kill_list, dev_kill_list);
457 }
458 
459 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
460 
461 /* Initialize ipmr pimreg/tunnel in_device */
462 static bool ipmr_init_vif_indev(const struct net_device *dev)
463 {
464 	struct in_device *in_dev;
465 
466 	ASSERT_RTNL();
467 
468 	in_dev = __in_dev_get_rtnl(dev);
469 	if (!in_dev)
470 		return false;
471 	ipv4_devconf_setall(in_dev);
472 	neigh_parms_data_state_setall(in_dev->arp_parms);
473 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
474 
475 	return true;
476 }
477 
478 static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
479 {
480 	struct net_device *tunnel_dev, *new_dev;
481 	struct ip_tunnel_parm_kern p = { };
482 	int err;
483 
484 	tunnel_dev = __dev_get_by_name(net, "tunl0");
485 	if (!tunnel_dev)
486 		goto out;
487 
488 	p.iph.daddr = v->vifc_rmt_addr.s_addr;
489 	p.iph.saddr = v->vifc_lcl_addr.s_addr;
490 	p.iph.version = 4;
491 	p.iph.ihl = 5;
492 	p.iph.protocol = IPPROTO_IPIP;
493 	sprintf(p.name, "dvmrp%d", v->vifc_vifi);
494 
495 	if (!tunnel_dev->netdev_ops->ndo_tunnel_ctl)
496 		goto out;
497 	err = tunnel_dev->netdev_ops->ndo_tunnel_ctl(tunnel_dev, &p,
498 			SIOCADDTUNNEL);
499 	if (err)
500 		goto out;
501 
502 	new_dev = __dev_get_by_name(net, p.name);
503 	if (!new_dev)
504 		goto out;
505 
506 	new_dev->flags |= IFF_MULTICAST;
507 	if (!ipmr_init_vif_indev(new_dev))
508 		goto out_unregister;
509 	if (dev_open(new_dev, NULL))
510 		goto out_unregister;
511 	dev_hold(new_dev);
512 	err = dev_set_allmulti(new_dev, 1);
513 	if (err) {
514 		dev_close(new_dev);
515 		tunnel_dev->netdev_ops->ndo_tunnel_ctl(tunnel_dev, &p,
516 				SIOCDELTUNNEL);
517 		dev_put(new_dev);
518 		new_dev = ERR_PTR(err);
519 	}
520 	return new_dev;
521 
522 out_unregister:
523 	unregister_netdevice(new_dev);
524 out:
525 	return ERR_PTR(-ENOBUFS);
526 }
527 
528 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
529 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
530 {
531 	struct net *net = dev_net(dev);
532 	struct mr_table *mrt;
533 	struct flowi4 fl4 = {
534 		.flowi4_oif	= dev->ifindex,
535 		.flowi4_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
536 		.flowi4_mark	= skb->mark,
537 	};
538 	int err;
539 
540 	err = ipmr_fib_lookup(net, &fl4, &mrt);
541 	if (err < 0) {
542 		kfree_skb(skb);
543 		return err;
544 	}
545 
546 	DEV_STATS_ADD(dev, tx_bytes, skb->len);
547 	DEV_STATS_INC(dev, tx_packets);
548 	rcu_read_lock();
549 
550 	/* Pairs with WRITE_ONCE() in vif_add() and vif_delete() */
551 	ipmr_cache_report(mrt, skb, READ_ONCE(mrt->mroute_reg_vif_num),
552 			  IGMPMSG_WHOLEPKT);
553 
554 	rcu_read_unlock();
555 	kfree_skb(skb);
556 	return NETDEV_TX_OK;
557 }
558 
559 static int reg_vif_get_iflink(const struct net_device *dev)
560 {
561 	return 0;
562 }
563 
564 static const struct net_device_ops reg_vif_netdev_ops = {
565 	.ndo_start_xmit	= reg_vif_xmit,
566 	.ndo_get_iflink = reg_vif_get_iflink,
567 };
568 
569 static void reg_vif_setup(struct net_device *dev)
570 {
571 	dev->type		= ARPHRD_PIMREG;
572 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
573 	dev->flags		= IFF_NOARP;
574 	dev->netdev_ops		= &reg_vif_netdev_ops;
575 	dev->needs_free_netdev	= true;
576 	dev->netns_immutable	= true;
577 }
578 
579 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
580 {
581 	struct net_device *dev;
582 	char name[IFNAMSIZ];
583 
584 	if (mrt->id == RT_TABLE_DEFAULT)
585 		sprintf(name, "pimreg");
586 	else
587 		sprintf(name, "pimreg%u", mrt->id);
588 
589 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
590 
591 	if (!dev)
592 		return NULL;
593 
594 	dev_net_set(dev, net);
595 
596 	if (register_netdevice(dev)) {
597 		free_netdev(dev);
598 		return NULL;
599 	}
600 
601 	if (!ipmr_init_vif_indev(dev))
602 		goto failure;
603 	if (dev_open(dev, NULL))
604 		goto failure;
605 
606 	dev_hold(dev);
607 
608 	return dev;
609 
610 failure:
611 	unregister_netdevice(dev);
612 	return NULL;
613 }
614 
615 /* called with rcu_read_lock() */
616 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
617 		     unsigned int pimlen)
618 {
619 	struct net_device *reg_dev = NULL;
620 	struct iphdr *encap;
621 	int vif_num;
622 
623 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
624 	/* Check that:
625 	 * a. packet is really sent to a multicast group
626 	 * b. packet is not a NULL-REGISTER
627 	 * c. packet is not truncated
628 	 */
629 	if (!ipv4_is_multicast(encap->daddr) ||
630 	    encap->tot_len == 0 ||
631 	    ntohs(encap->tot_len) + pimlen > skb->len)
632 		return 1;
633 
634 	/* Pairs with WRITE_ONCE() in vif_add()/vid_delete() */
635 	vif_num = READ_ONCE(mrt->mroute_reg_vif_num);
636 	if (vif_num >= 0)
637 		reg_dev = vif_dev_read(&mrt->vif_table[vif_num]);
638 	if (!reg_dev)
639 		return 1;
640 
641 	skb->mac_header = skb->network_header;
642 	skb_pull(skb, (u8 *)encap - skb->data);
643 	skb_reset_network_header(skb);
644 	skb->protocol = htons(ETH_P_IP);
645 	skb->ip_summed = CHECKSUM_NONE;
646 
647 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
648 
649 	netif_rx(skb);
650 
651 	return NET_RX_SUCCESS;
652 }
653 #else
654 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
655 {
656 	return NULL;
657 }
658 #endif
659 
660 static int call_ipmr_vif_entry_notifiers(struct net *net,
661 					 enum fib_event_type event_type,
662 					 struct vif_device *vif,
663 					 struct net_device *vif_dev,
664 					 vifi_t vif_index, u32 tb_id)
665 {
666 	return mr_call_vif_notifiers(net, RTNL_FAMILY_IPMR, event_type,
667 				     vif, vif_dev, vif_index, tb_id,
668 				     &net->ipv4.ipmr_seq);
669 }
670 
671 static int call_ipmr_mfc_entry_notifiers(struct net *net,
672 					 enum fib_event_type event_type,
673 					 struct mfc_cache *mfc, u32 tb_id)
674 {
675 	return mr_call_mfc_notifiers(net, RTNL_FAMILY_IPMR, event_type,
676 				     &mfc->_c, tb_id, &net->ipv4.ipmr_seq);
677 }
678 
679 /**
680  *	vif_delete - Delete a VIF entry
681  *	@mrt: Table to delete from
682  *	@vifi: VIF identifier to delete
683  *	@notify: Set to 1, if the caller is a notifier_call
684  *	@head: if unregistering the VIF, place it on this queue
685  */
686 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
687 		      struct list_head *head)
688 {
689 	struct net *net = read_pnet(&mrt->net);
690 	struct vif_device *v;
691 	struct net_device *dev;
692 	struct in_device *in_dev;
693 
694 	if (vifi < 0 || vifi >= mrt->maxvif)
695 		return -EADDRNOTAVAIL;
696 
697 	v = &mrt->vif_table[vifi];
698 
699 	dev = rtnl_dereference(v->dev);
700 	if (!dev)
701 		return -EADDRNOTAVAIL;
702 
703 	spin_lock(&mrt_lock);
704 	call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_DEL, v, dev,
705 				      vifi, mrt->id);
706 	RCU_INIT_POINTER(v->dev, NULL);
707 
708 	if (vifi == mrt->mroute_reg_vif_num) {
709 		/* Pairs with READ_ONCE() in ipmr_cache_report() and reg_vif_xmit() */
710 		WRITE_ONCE(mrt->mroute_reg_vif_num, -1);
711 	}
712 	if (vifi + 1 == mrt->maxvif) {
713 		int tmp;
714 
715 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
716 			if (VIF_EXISTS(mrt, tmp))
717 				break;
718 		}
719 		WRITE_ONCE(mrt->maxvif, tmp + 1);
720 	}
721 
722 	spin_unlock(&mrt_lock);
723 
724 	dev_set_allmulti(dev, -1);
725 
726 	in_dev = __in_dev_get_rtnl(dev);
727 	if (in_dev) {
728 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
729 		inet_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
730 					    NETCONFA_MC_FORWARDING,
731 					    dev->ifindex, &in_dev->cnf);
732 		ip_rt_multicast_event(in_dev);
733 	}
734 
735 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
736 		unregister_netdevice_queue(dev, head);
737 
738 	netdev_put(dev, &v->dev_tracker);
739 	return 0;
740 }
741 
742 static void ipmr_cache_free_rcu(struct rcu_head *head)
743 {
744 	struct mr_mfc *c = container_of(head, struct mr_mfc, rcu);
745 
746 	kmem_cache_free(mrt_cachep, (struct mfc_cache *)c);
747 }
748 
749 static void ipmr_cache_free(struct mfc_cache *c)
750 {
751 	call_rcu(&c->_c.rcu, ipmr_cache_free_rcu);
752 }
753 
754 /* Destroy an unresolved cache entry, killing queued skbs
755  * and reporting error to netlink readers.
756  */
757 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
758 {
759 	struct net *net = read_pnet(&mrt->net);
760 	struct sk_buff *skb;
761 	struct nlmsgerr *e;
762 
763 	atomic_dec(&mrt->cache_resolve_queue_len);
764 
765 	while ((skb = skb_dequeue(&c->_c.mfc_un.unres.unresolved))) {
766 		if (ip_hdr(skb)->version == 0) {
767 			struct nlmsghdr *nlh = skb_pull(skb,
768 							sizeof(struct iphdr));
769 			nlh->nlmsg_type = NLMSG_ERROR;
770 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
771 			skb_trim(skb, nlh->nlmsg_len);
772 			e = nlmsg_data(nlh);
773 			e->error = -ETIMEDOUT;
774 			memset(&e->msg, 0, sizeof(e->msg));
775 
776 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
777 		} else {
778 			kfree_skb(skb);
779 		}
780 	}
781 
782 	ipmr_cache_free(c);
783 }
784 
785 /* Timer process for the unresolved queue. */
786 static void ipmr_expire_process(struct timer_list *t)
787 {
788 	struct mr_table *mrt = timer_container_of(mrt, t, ipmr_expire_timer);
789 	struct mr_mfc *c, *next;
790 	unsigned long expires;
791 	unsigned long now;
792 
793 	if (!spin_trylock(&mfc_unres_lock)) {
794 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
795 		return;
796 	}
797 
798 	if (list_empty(&mrt->mfc_unres_queue))
799 		goto out;
800 
801 	now = jiffies;
802 	expires = 10*HZ;
803 
804 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
805 		if (time_after(c->mfc_un.unres.expires, now)) {
806 			unsigned long interval = c->mfc_un.unres.expires - now;
807 			if (interval < expires)
808 				expires = interval;
809 			continue;
810 		}
811 
812 		list_del(&c->list);
813 		mroute_netlink_event(mrt, (struct mfc_cache *)c, RTM_DELROUTE);
814 		ipmr_destroy_unres(mrt, (struct mfc_cache *)c);
815 	}
816 
817 	if (!list_empty(&mrt->mfc_unres_queue))
818 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
819 
820 out:
821 	spin_unlock(&mfc_unres_lock);
822 }
823 
824 /* Fill oifs list. It is called under locked mrt_lock. */
825 static void ipmr_update_thresholds(struct mr_table *mrt, struct mr_mfc *cache,
826 				   unsigned char *ttls)
827 {
828 	int vifi;
829 
830 	cache->mfc_un.res.minvif = MAXVIFS;
831 	cache->mfc_un.res.maxvif = 0;
832 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
833 
834 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
835 		if (VIF_EXISTS(mrt, vifi) &&
836 		    ttls[vifi] && ttls[vifi] < 255) {
837 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
838 			if (cache->mfc_un.res.minvif > vifi)
839 				cache->mfc_un.res.minvif = vifi;
840 			if (cache->mfc_un.res.maxvif <= vifi)
841 				cache->mfc_un.res.maxvif = vifi + 1;
842 		}
843 	}
844 	WRITE_ONCE(cache->mfc_un.res.lastuse, jiffies);
845 }
846 
847 static int vif_add(struct net *net, struct mr_table *mrt,
848 		   struct vifctl *vifc, int mrtsock)
849 {
850 	struct netdev_phys_item_id ppid = { };
851 	int vifi = vifc->vifc_vifi;
852 	struct vif_device *v = &mrt->vif_table[vifi];
853 	struct net_device *dev;
854 	struct in_device *in_dev;
855 	int err;
856 
857 	/* Is vif busy ? */
858 	if (VIF_EXISTS(mrt, vifi))
859 		return -EADDRINUSE;
860 
861 	switch (vifc->vifc_flags) {
862 	case VIFF_REGISTER:
863 		if (!ipmr_pimsm_enabled())
864 			return -EINVAL;
865 		/* Special Purpose VIF in PIM
866 		 * All the packets will be sent to the daemon
867 		 */
868 		if (mrt->mroute_reg_vif_num >= 0)
869 			return -EADDRINUSE;
870 		dev = ipmr_reg_vif(net, mrt);
871 		if (!dev)
872 			return -ENOBUFS;
873 		err = dev_set_allmulti(dev, 1);
874 		if (err) {
875 			unregister_netdevice(dev);
876 			dev_put(dev);
877 			return err;
878 		}
879 		break;
880 	case VIFF_TUNNEL:
881 		dev = ipmr_new_tunnel(net, vifc);
882 		if (IS_ERR(dev))
883 			return PTR_ERR(dev);
884 		break;
885 	case VIFF_USE_IFINDEX:
886 	case 0:
887 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
888 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
889 			if (dev && !__in_dev_get_rtnl(dev)) {
890 				dev_put(dev);
891 				return -EADDRNOTAVAIL;
892 			}
893 		} else {
894 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
895 		}
896 		if (!dev)
897 			return -EADDRNOTAVAIL;
898 		err = dev_set_allmulti(dev, 1);
899 		if (err) {
900 			dev_put(dev);
901 			return err;
902 		}
903 		break;
904 	default:
905 		return -EINVAL;
906 	}
907 
908 	in_dev = __in_dev_get_rtnl(dev);
909 	if (!in_dev) {
910 		dev_put(dev);
911 		return -EADDRNOTAVAIL;
912 	}
913 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
914 	inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING,
915 				    dev->ifindex, &in_dev->cnf);
916 	ip_rt_multicast_event(in_dev);
917 
918 	/* Fill in the VIF structures */
919 	vif_device_init(v, dev, vifc->vifc_rate_limit,
920 			vifc->vifc_threshold,
921 			vifc->vifc_flags | (!mrtsock ? VIFF_STATIC : 0),
922 			(VIFF_TUNNEL | VIFF_REGISTER));
923 
924 	err = netif_get_port_parent_id(dev, &ppid, true);
925 	if (err == 0) {
926 		memcpy(v->dev_parent_id.id, ppid.id, ppid.id_len);
927 		v->dev_parent_id.id_len = ppid.id_len;
928 	} else {
929 		v->dev_parent_id.id_len = 0;
930 	}
931 
932 	v->local = vifc->vifc_lcl_addr.s_addr;
933 	v->remote = vifc->vifc_rmt_addr.s_addr;
934 
935 	/* And finish update writing critical data */
936 	spin_lock(&mrt_lock);
937 	rcu_assign_pointer(v->dev, dev);
938 	netdev_tracker_alloc(dev, &v->dev_tracker, GFP_ATOMIC);
939 	if (v->flags & VIFF_REGISTER) {
940 		/* Pairs with READ_ONCE() in ipmr_cache_report() and reg_vif_xmit() */
941 		WRITE_ONCE(mrt->mroute_reg_vif_num, vifi);
942 	}
943 	if (vifi+1 > mrt->maxvif)
944 		WRITE_ONCE(mrt->maxvif, vifi + 1);
945 	spin_unlock(&mrt_lock);
946 	call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD, v, dev,
947 				      vifi, mrt->id);
948 	return 0;
949 }
950 
951 /* called with rcu_read_lock() */
952 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
953 					 __be32 origin,
954 					 __be32 mcastgrp)
955 {
956 	struct mfc_cache_cmp_arg arg = {
957 			.mfc_mcastgrp = mcastgrp,
958 			.mfc_origin = origin
959 	};
960 
961 	return mr_mfc_find(mrt, &arg);
962 }
963 
964 /* Look for a (*,G) entry */
965 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
966 					     __be32 mcastgrp, int vifi)
967 {
968 	struct mfc_cache_cmp_arg arg = {
969 			.mfc_mcastgrp = mcastgrp,
970 			.mfc_origin = htonl(INADDR_ANY)
971 	};
972 
973 	if (mcastgrp == htonl(INADDR_ANY))
974 		return mr_mfc_find_any_parent(mrt, vifi);
975 	return mr_mfc_find_any(mrt, vifi, &arg);
976 }
977 
978 /* Look for a (S,G,iif) entry if parent != -1 */
979 static struct mfc_cache *ipmr_cache_find_parent(struct mr_table *mrt,
980 						__be32 origin, __be32 mcastgrp,
981 						int parent)
982 {
983 	struct mfc_cache_cmp_arg arg = {
984 			.mfc_mcastgrp = mcastgrp,
985 			.mfc_origin = origin,
986 	};
987 
988 	return mr_mfc_find_parent(mrt, &arg, parent);
989 }
990 
991 /* Allocate a multicast cache entry */
992 static struct mfc_cache *ipmr_cache_alloc(void)
993 {
994 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
995 
996 	if (c) {
997 		c->_c.mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
998 		c->_c.mfc_un.res.minvif = MAXVIFS;
999 		c->_c.free = ipmr_cache_free_rcu;
1000 		refcount_set(&c->_c.mfc_un.res.refcount, 1);
1001 	}
1002 	return c;
1003 }
1004 
1005 static struct mfc_cache *ipmr_cache_alloc_unres(void)
1006 {
1007 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
1008 
1009 	if (c) {
1010 		skb_queue_head_init(&c->_c.mfc_un.unres.unresolved);
1011 		c->_c.mfc_un.unres.expires = jiffies + 10 * HZ;
1012 	}
1013 	return c;
1014 }
1015 
1016 /* A cache entry has gone into a resolved state from queued */
1017 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
1018 			       struct mfc_cache *uc, struct mfc_cache *c)
1019 {
1020 	struct sk_buff *skb;
1021 	struct nlmsgerr *e;
1022 
1023 	/* Play the pending entries through our router */
1024 	while ((skb = __skb_dequeue(&uc->_c.mfc_un.unres.unresolved))) {
1025 		if (ip_hdr(skb)->version == 0) {
1026 			struct nlmsghdr *nlh = skb_pull(skb,
1027 							sizeof(struct iphdr));
1028 
1029 			if (mr_fill_mroute(mrt, skb, &c->_c,
1030 					   nlmsg_data(nlh)) > 0) {
1031 				nlh->nlmsg_len = skb_tail_pointer(skb) -
1032 						 (u8 *)nlh;
1033 			} else {
1034 				nlh->nlmsg_type = NLMSG_ERROR;
1035 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
1036 				skb_trim(skb, nlh->nlmsg_len);
1037 				e = nlmsg_data(nlh);
1038 				e->error = -EMSGSIZE;
1039 				memset(&e->msg, 0, sizeof(e->msg));
1040 			}
1041 
1042 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
1043 		} else {
1044 			rcu_read_lock();
1045 			ip_mr_forward(net, mrt, skb->dev, skb, c, 0);
1046 			rcu_read_unlock();
1047 		}
1048 	}
1049 }
1050 
1051 /* Bounce a cache query up to mrouted and netlink.
1052  *
1053  * Called under rcu_read_lock().
1054  */
1055 static int ipmr_cache_report(const struct mr_table *mrt,
1056 			     struct sk_buff *pkt, vifi_t vifi, int assert)
1057 {
1058 	const int ihl = ip_hdrlen(pkt);
1059 	struct sock *mroute_sk;
1060 	struct igmphdr *igmp;
1061 	struct igmpmsg *msg;
1062 	struct sk_buff *skb;
1063 	int ret;
1064 
1065 	mroute_sk = rcu_dereference(mrt->mroute_sk);
1066 	if (!mroute_sk)
1067 		return -EINVAL;
1068 
1069 	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE)
1070 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
1071 	else
1072 		skb = alloc_skb(128, GFP_ATOMIC);
1073 
1074 	if (!skb)
1075 		return -ENOBUFS;
1076 
1077 	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE) {
1078 		/* Ugly, but we have no choice with this interface.
1079 		 * Duplicate old header, fix ihl, length etc.
1080 		 * And all this only to mangle msg->im_msgtype and
1081 		 * to set msg->im_mbz to "mbz" :-)
1082 		 */
1083 		skb_push(skb, sizeof(struct iphdr));
1084 		skb_reset_network_header(skb);
1085 		skb_reset_transport_header(skb);
1086 		msg = (struct igmpmsg *)skb_network_header(skb);
1087 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
1088 		msg->im_msgtype = assert;
1089 		msg->im_mbz = 0;
1090 		if (assert == IGMPMSG_WRVIFWHOLE) {
1091 			msg->im_vif = vifi;
1092 			msg->im_vif_hi = vifi >> 8;
1093 		} else {
1094 			/* Pairs with WRITE_ONCE() in vif_add() and vif_delete() */
1095 			int vif_num = READ_ONCE(mrt->mroute_reg_vif_num);
1096 
1097 			msg->im_vif = vif_num;
1098 			msg->im_vif_hi = vif_num >> 8;
1099 		}
1100 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
1101 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
1102 					     sizeof(struct iphdr));
1103 	} else {
1104 		/* Copy the IP header */
1105 		skb_set_network_header(skb, skb->len);
1106 		skb_put(skb, ihl);
1107 		skb_copy_to_linear_data(skb, pkt->data, ihl);
1108 		/* Flag to the kernel this is a route add */
1109 		ip_hdr(skb)->protocol = 0;
1110 		msg = (struct igmpmsg *)skb_network_header(skb);
1111 		msg->im_vif = vifi;
1112 		msg->im_vif_hi = vifi >> 8;
1113 		ipv4_pktinfo_prepare(mroute_sk, pkt, false);
1114 		memcpy(skb->cb, pkt->cb, sizeof(skb->cb));
1115 		/* Add our header.
1116 		 * Note that code, csum and group fields are cleared.
1117 		 */
1118 		igmp = skb_put_zero(skb, sizeof(struct igmphdr));
1119 		igmp->type = assert;
1120 		msg->im_msgtype = assert;
1121 		ip_hdr(skb)->tot_len = htons(skb->len);	/* Fix the length */
1122 		skb->transport_header = skb->network_header;
1123 	}
1124 
1125 	igmpmsg_netlink_event(mrt, skb);
1126 
1127 	/* Deliver to mrouted */
1128 	ret = sock_queue_rcv_skb(mroute_sk, skb);
1129 
1130 	if (ret < 0) {
1131 		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1132 		kfree_skb(skb);
1133 	}
1134 
1135 	return ret;
1136 }
1137 
1138 /* Queue a packet for resolution. It gets locked cache entry! */
1139 /* Called under rcu_read_lock() */
1140 static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
1141 				 struct sk_buff *skb, struct net_device *dev)
1142 {
1143 	struct net *net = read_pnet(&mrt->net);
1144 	const struct iphdr *iph = ip_hdr(skb);
1145 	struct mfc_cache *c = NULL;
1146 	bool found = false;
1147 	int err;
1148 
1149 	spin_lock_bh(&mfc_unres_lock);
1150 
1151 	if (!check_net(net)) {
1152 		err = -EINVAL;
1153 		goto err;
1154 	}
1155 
1156 	list_for_each_entry(c, &mrt->mfc_unres_queue, _c.list) {
1157 		if (c->mfc_mcastgrp == iph->daddr &&
1158 		    c->mfc_origin == iph->saddr) {
1159 			found = true;
1160 			break;
1161 		}
1162 	}
1163 
1164 	if (!found) {
1165 		/* Create a new entry if allowable */
1166 		c = ipmr_cache_alloc_unres();
1167 		if (!c) {
1168 			err = -ENOBUFS;
1169 			goto err;
1170 		}
1171 
1172 		/* Fill in the new cache entry */
1173 		c->_c.mfc_parent = -1;
1174 		c->mfc_origin	= iph->saddr;
1175 		c->mfc_mcastgrp	= iph->daddr;
1176 
1177 		/* Reflect first query at mrouted. */
1178 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1179 		if (err < 0)
1180 			goto err;
1181 
1182 		atomic_inc(&mrt->cache_resolve_queue_len);
1183 		list_add(&c->_c.list, &mrt->mfc_unres_queue);
1184 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1185 
1186 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1187 			mod_timer(&mrt->ipmr_expire_timer,
1188 				  c->_c.mfc_un.unres.expires);
1189 	}
1190 
1191 	/* See if we can append the packet */
1192 	if (c->_c.mfc_un.unres.unresolved.qlen > 3) {
1193 		c = NULL;
1194 		err = -ENOBUFS;
1195 		goto err;
1196 	}
1197 
1198 	if (dev) {
1199 		skb->dev = dev;
1200 		skb->skb_iif = dev->ifindex;
1201 	}
1202 
1203 	skb_queue_tail(&c->_c.mfc_un.unres.unresolved, skb);
1204 
1205 	spin_unlock_bh(&mfc_unres_lock);
1206 	return 0;
1207 
1208 err:
1209 	spin_unlock_bh(&mfc_unres_lock);
1210 	if (c)
1211 		ipmr_cache_free(c);
1212 	kfree_skb(skb);
1213 	return err;
1214 }
1215 
1216 /* MFC cache manipulation by user space mroute daemon */
1217 
1218 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1219 {
1220 	struct net *net = read_pnet(&mrt->net);
1221 	struct mfc_cache *c;
1222 
1223 	rcu_read_lock();
1224 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1225 				   mfc->mfcc_mcastgrp.s_addr, parent);
1226 	rcu_read_unlock();
1227 	if (!c)
1228 		return -ENOENT;
1229 	rhltable_remove(&mrt->mfc_hash, &c->_c.mnode, ipmr_rht_params);
1230 	list_del_rcu(&c->_c.list);
1231 	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, c, mrt->id);
1232 	mroute_netlink_event(mrt, c, RTM_DELROUTE);
1233 	mr_cache_put(&c->_c);
1234 
1235 	return 0;
1236 }
1237 
1238 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1239 			struct mfcctl *mfc, int mrtsock, int parent)
1240 {
1241 	struct mfc_cache *uc, *c;
1242 	struct mr_mfc *_uc;
1243 	bool found;
1244 	int ret;
1245 
1246 	if (mfc->mfcc_parent >= MAXVIFS)
1247 		return -ENFILE;
1248 
1249 	rcu_read_lock();
1250 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1251 				   mfc->mfcc_mcastgrp.s_addr, parent);
1252 	rcu_read_unlock();
1253 	if (c) {
1254 		spin_lock(&mrt_lock);
1255 		c->_c.mfc_parent = mfc->mfcc_parent;
1256 		ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
1257 		if (!mrtsock)
1258 			c->_c.mfc_flags |= MFC_STATIC;
1259 		spin_unlock(&mrt_lock);
1260 		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, c,
1261 					      mrt->id);
1262 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1263 		return 0;
1264 	}
1265 
1266 	if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1267 	    !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1268 		return -EINVAL;
1269 
1270 	c = ipmr_cache_alloc();
1271 	if (!c)
1272 		return -ENOMEM;
1273 
1274 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1275 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1276 	c->_c.mfc_parent = mfc->mfcc_parent;
1277 	ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
1278 	if (!mrtsock)
1279 		c->_c.mfc_flags |= MFC_STATIC;
1280 
1281 	ret = rhltable_insert_key(&mrt->mfc_hash, &c->cmparg, &c->_c.mnode,
1282 				  ipmr_rht_params);
1283 	if (ret) {
1284 		pr_err("ipmr: rhtable insert error %d\n", ret);
1285 		ipmr_cache_free(c);
1286 		return ret;
1287 	}
1288 	list_add_tail_rcu(&c->_c.list, &mrt->mfc_cache_list);
1289 	/* Check to see if we resolved a queued list. If so we
1290 	 * need to send on the frames and tidy up.
1291 	 */
1292 	found = false;
1293 	spin_lock_bh(&mfc_unres_lock);
1294 	list_for_each_entry(_uc, &mrt->mfc_unres_queue, list) {
1295 		uc = (struct mfc_cache *)_uc;
1296 		if (uc->mfc_origin == c->mfc_origin &&
1297 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1298 			list_del(&_uc->list);
1299 			atomic_dec(&mrt->cache_resolve_queue_len);
1300 			found = true;
1301 			break;
1302 		}
1303 	}
1304 	if (list_empty(&mrt->mfc_unres_queue))
1305 		timer_delete(&mrt->ipmr_expire_timer);
1306 	spin_unlock_bh(&mfc_unres_lock);
1307 
1308 	if (found) {
1309 		ipmr_cache_resolve(net, mrt, uc, c);
1310 		ipmr_cache_free(uc);
1311 	}
1312 	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, c, mrt->id);
1313 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1314 	return 0;
1315 }
1316 
1317 /* Close the multicast socket, and clear the vif tables etc */
1318 static void mroute_clean_tables(struct mr_table *mrt, int flags,
1319 				struct list_head *dev_kill_list)
1320 {
1321 	struct net *net = read_pnet(&mrt->net);
1322 	struct mfc_cache *cache;
1323 	struct mr_mfc *c, *tmp;
1324 	int i;
1325 
1326 	/* Shut down all active vif entries */
1327 	if (flags & (MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC)) {
1328 		for (i = 0; i < mrt->maxvif; i++) {
1329 			if (((mrt->vif_table[i].flags & VIFF_STATIC) &&
1330 			     !(flags & MRT_FLUSH_VIFS_STATIC)) ||
1331 			    (!(mrt->vif_table[i].flags & VIFF_STATIC) && !(flags & MRT_FLUSH_VIFS)))
1332 				continue;
1333 			vif_delete(mrt, i, 0, dev_kill_list);
1334 		}
1335 	}
1336 
1337 	/* Wipe the cache */
1338 	if (flags & (MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC)) {
1339 		mutex_lock(&net->ipv4.mfc_mutex);
1340 
1341 		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
1342 			if (((c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC_STATIC)) ||
1343 			    (!(c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC)))
1344 				continue;
1345 			rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
1346 			list_del_rcu(&c->list);
1347 			cache = (struct mfc_cache *)c;
1348 			call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
1349 						      mrt->id);
1350 			mroute_netlink_event(mrt, cache, RTM_DELROUTE);
1351 			mr_cache_put(c);
1352 		}
1353 
1354 		mutex_unlock(&net->ipv4.mfc_mutex);
1355 	}
1356 
1357 	if (flags & MRT_FLUSH_MFC) {
1358 		if (atomic_read(&mrt->cache_resolve_queue_len) != 0 || !check_net(net)) {
1359 			spin_lock_bh(&mfc_unres_lock);
1360 			list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
1361 				list_del(&c->list);
1362 				cache = (struct mfc_cache *)c;
1363 				mroute_netlink_event(mrt, cache, RTM_DELROUTE);
1364 				ipmr_destroy_unres(mrt, cache);
1365 			}
1366 			spin_unlock_bh(&mfc_unres_lock);
1367 		}
1368 	}
1369 }
1370 
1371 /* called from ip_ra_control(), before an RCU grace period,
1372  * we don't need to call synchronize_rcu() here
1373  */
1374 static void mrtsock_destruct(struct sock *sk)
1375 {
1376 	struct net *net = sock_net(sk);
1377 	LIST_HEAD(dev_kill_list);
1378 	struct mr_table *mrt;
1379 
1380 	rtnl_lock();
1381 
1382 	ipmr_for_each_table(mrt, net) {
1383 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1384 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1385 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1386 						    NETCONFA_MC_FORWARDING,
1387 						    NETCONFA_IFINDEX_ALL,
1388 						    net->ipv4.devconf_all);
1389 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1390 			mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_MFC,
1391 					    &dev_kill_list);
1392 		}
1393 	}
1394 
1395 	unregister_netdevice_many(&dev_kill_list);
1396 
1397 	rtnl_unlock();
1398 }
1399 
1400 /* Socket options and virtual interface manipulation. The whole
1401  * virtual interface system is a complete heap, but unfortunately
1402  * that's how BSD mrouted happens to think. Maybe one day with a proper
1403  * MOSPF/PIM router set up we can clean this up.
1404  */
1405 
1406 int ip_mroute_setsockopt(struct sock *sk, int optname, sockptr_t optval,
1407 			 unsigned int optlen)
1408 {
1409 	struct net *net = sock_net(sk);
1410 	int val, ret = 0, parent = 0;
1411 	struct mr_table *mrt;
1412 	struct vifctl vif;
1413 	struct mfcctl mfc;
1414 	bool do_wrvifwhole;
1415 	u32 uval;
1416 
1417 	/* There's one exception to the lock - MRT_DONE which needs to unlock */
1418 	rtnl_lock();
1419 	if (sk->sk_type != SOCK_RAW ||
1420 	    inet_sk(sk)->inet_num != IPPROTO_IGMP) {
1421 		ret = -EOPNOTSUPP;
1422 		goto out_unlock;
1423 	}
1424 
1425 	mrt = __ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1426 	if (!mrt) {
1427 		ret = -ENOENT;
1428 		goto out_unlock;
1429 	}
1430 	if (optname != MRT_INIT) {
1431 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1432 		    !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
1433 			ret = -EACCES;
1434 			goto out_unlock;
1435 		}
1436 	}
1437 
1438 	switch (optname) {
1439 	case MRT_INIT:
1440 		if (optlen != sizeof(int)) {
1441 			ret = -EINVAL;
1442 			break;
1443 		}
1444 		if (rtnl_dereference(mrt->mroute_sk)) {
1445 			ret = -EADDRINUSE;
1446 			break;
1447 		}
1448 
1449 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1450 		if (ret == 0) {
1451 			rcu_assign_pointer(mrt->mroute_sk, sk);
1452 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1453 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1454 						    NETCONFA_MC_FORWARDING,
1455 						    NETCONFA_IFINDEX_ALL,
1456 						    net->ipv4.devconf_all);
1457 		}
1458 		break;
1459 	case MRT_DONE:
1460 		if (sk != rcu_access_pointer(mrt->mroute_sk)) {
1461 			ret = -EACCES;
1462 		} else {
1463 			/* We need to unlock here because mrtsock_destruct takes
1464 			 * care of rtnl itself and we can't change that due to
1465 			 * the IP_ROUTER_ALERT setsockopt which runs without it.
1466 			 */
1467 			rtnl_unlock();
1468 			ret = ip_ra_control(sk, 0, NULL);
1469 			goto out;
1470 		}
1471 		break;
1472 	case MRT_ADD_VIF:
1473 	case MRT_DEL_VIF:
1474 		if (optlen != sizeof(vif)) {
1475 			ret = -EINVAL;
1476 			break;
1477 		}
1478 		if (copy_from_sockptr(&vif, optval, sizeof(vif))) {
1479 			ret = -EFAULT;
1480 			break;
1481 		}
1482 		if (vif.vifc_vifi >= MAXVIFS) {
1483 			ret = -ENFILE;
1484 			break;
1485 		}
1486 		if (optname == MRT_ADD_VIF) {
1487 			ret = vif_add(net, mrt, &vif,
1488 				      sk == rtnl_dereference(mrt->mroute_sk));
1489 		} else {
1490 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1491 		}
1492 		break;
1493 	/* Manipulate the forwarding caches. These live
1494 	 * in a sort of kernel/user symbiosis.
1495 	 */
1496 	case MRT_ADD_MFC:
1497 	case MRT_DEL_MFC:
1498 		parent = -1;
1499 		fallthrough;
1500 	case MRT_ADD_MFC_PROXY:
1501 	case MRT_DEL_MFC_PROXY:
1502 		if (optlen != sizeof(mfc)) {
1503 			ret = -EINVAL;
1504 			break;
1505 		}
1506 		if (copy_from_sockptr(&mfc, optval, sizeof(mfc))) {
1507 			ret = -EFAULT;
1508 			break;
1509 		}
1510 		if (parent == 0)
1511 			parent = mfc.mfcc_parent;
1512 
1513 		mutex_lock(&net->ipv4.mfc_mutex);
1514 
1515 		if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1516 			ret = ipmr_mfc_delete(mrt, &mfc, parent);
1517 		else
1518 			ret = ipmr_mfc_add(net, mrt, &mfc,
1519 					   sk == rtnl_dereference(mrt->mroute_sk),
1520 					   parent);
1521 
1522 		mutex_unlock(&net->ipv4.mfc_mutex);
1523 		break;
1524 	case MRT_FLUSH: {
1525 		LIST_HEAD(dev_kill_list);
1526 
1527 		if (optlen != sizeof(val)) {
1528 			ret = -EINVAL;
1529 			break;
1530 		}
1531 		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1532 			ret = -EFAULT;
1533 			break;
1534 		}
1535 
1536 		mroute_clean_tables(mrt, val, &dev_kill_list);
1537 		unregister_netdevice_many(&dev_kill_list);
1538 		break;
1539 	}
1540 	/* Control PIM assert. */
1541 	case MRT_ASSERT:
1542 		if (optlen != sizeof(val)) {
1543 			ret = -EINVAL;
1544 			break;
1545 		}
1546 		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1547 			ret = -EFAULT;
1548 			break;
1549 		}
1550 		WRITE_ONCE(mrt->mroute_do_assert, val);
1551 		break;
1552 	case MRT_PIM:
1553 		if (!ipmr_pimsm_enabled()) {
1554 			ret = -ENOPROTOOPT;
1555 			break;
1556 		}
1557 		if (optlen != sizeof(val)) {
1558 			ret = -EINVAL;
1559 			break;
1560 		}
1561 		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1562 			ret = -EFAULT;
1563 			break;
1564 		}
1565 
1566 		do_wrvifwhole = (val == IGMPMSG_WRVIFWHOLE);
1567 		val = !!val;
1568 		if (val != mrt->mroute_do_pim) {
1569 			WRITE_ONCE(mrt->mroute_do_pim, val);
1570 			WRITE_ONCE(mrt->mroute_do_assert, val);
1571 			WRITE_ONCE(mrt->mroute_do_wrvifwhole, do_wrvifwhole);
1572 		}
1573 		break;
1574 	case MRT_TABLE:
1575 		if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) {
1576 			ret = -ENOPROTOOPT;
1577 			break;
1578 		}
1579 		if (optlen != sizeof(uval)) {
1580 			ret = -EINVAL;
1581 			break;
1582 		}
1583 		if (copy_from_sockptr(&uval, optval, sizeof(uval))) {
1584 			ret = -EFAULT;
1585 			break;
1586 		}
1587 
1588 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1589 			ret = -EBUSY;
1590 		} else {
1591 			mrt = ipmr_new_table(net, uval);
1592 			if (IS_ERR(mrt))
1593 				ret = PTR_ERR(mrt);
1594 			else
1595 				raw_sk(sk)->ipmr_table = uval;
1596 		}
1597 		break;
1598 	/* Spurious command, or MRT_VERSION which you cannot set. */
1599 	default:
1600 		ret = -ENOPROTOOPT;
1601 	}
1602 out_unlock:
1603 	rtnl_unlock();
1604 out:
1605 	return ret;
1606 }
1607 
1608 /* Execute if this ioctl is a special mroute ioctl */
1609 int ipmr_sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1610 {
1611 	switch (cmd) {
1612 	/* These userspace buffers will be consumed by ipmr_ioctl() */
1613 	case SIOCGETVIFCNT: {
1614 		struct sioc_vif_req buffer;
1615 
1616 		return sock_ioctl_inout(sk, cmd, arg, &buffer,
1617 				      sizeof(buffer));
1618 		}
1619 	case SIOCGETSGCNT: {
1620 		struct sioc_sg_req buffer;
1621 
1622 		return sock_ioctl_inout(sk, cmd, arg, &buffer,
1623 				      sizeof(buffer));
1624 		}
1625 	}
1626 	/* return code > 0 means that the ioctl was not executed */
1627 	return 1;
1628 }
1629 
1630 /* Getsock opt support for the multicast routing system. */
1631 int ip_mroute_getsockopt(struct sock *sk, int optname, sockptr_t optval,
1632 			 sockptr_t optlen)
1633 {
1634 	int olr;
1635 	int val;
1636 	struct net *net = sock_net(sk);
1637 	struct mr_table *mrt;
1638 
1639 	if (sk->sk_type != SOCK_RAW ||
1640 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1641 		return -EOPNOTSUPP;
1642 
1643 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1644 	if (!mrt)
1645 		return -ENOENT;
1646 
1647 	switch (optname) {
1648 	case MRT_VERSION:
1649 		val = 0x0305;
1650 		break;
1651 	case MRT_PIM:
1652 		if (!ipmr_pimsm_enabled())
1653 			return -ENOPROTOOPT;
1654 		val = READ_ONCE(mrt->mroute_do_pim);
1655 		break;
1656 	case MRT_ASSERT:
1657 		val = READ_ONCE(mrt->mroute_do_assert);
1658 		break;
1659 	default:
1660 		return -ENOPROTOOPT;
1661 	}
1662 
1663 	if (copy_from_sockptr(&olr, optlen, sizeof(int)))
1664 		return -EFAULT;
1665 	if (olr < 0)
1666 		return -EINVAL;
1667 
1668 	olr = min_t(unsigned int, olr, sizeof(int));
1669 
1670 	if (copy_to_sockptr(optlen, &olr, sizeof(int)))
1671 		return -EFAULT;
1672 	if (copy_to_sockptr(optval, &val, olr))
1673 		return -EFAULT;
1674 	return 0;
1675 }
1676 
1677 /* The IP multicast ioctl support routines. */
1678 int ipmr_ioctl(struct sock *sk, int cmd, void *arg)
1679 {
1680 	struct vif_device *vif;
1681 	struct mfc_cache *c;
1682 	struct net *net = sock_net(sk);
1683 	struct sioc_vif_req *vr;
1684 	struct sioc_sg_req *sr;
1685 	struct mr_table *mrt;
1686 
1687 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1688 	if (!mrt)
1689 		return -ENOENT;
1690 
1691 	switch (cmd) {
1692 	case SIOCGETVIFCNT:
1693 		vr = (struct sioc_vif_req *)arg;
1694 		if (vr->vifi >= mrt->maxvif)
1695 			return -EINVAL;
1696 		vr->vifi = array_index_nospec(vr->vifi, mrt->maxvif);
1697 		rcu_read_lock();
1698 		vif = &mrt->vif_table[vr->vifi];
1699 		if (VIF_EXISTS(mrt, vr->vifi)) {
1700 			vr->icount = READ_ONCE(vif->pkt_in);
1701 			vr->ocount = READ_ONCE(vif->pkt_out);
1702 			vr->ibytes = READ_ONCE(vif->bytes_in);
1703 			vr->obytes = READ_ONCE(vif->bytes_out);
1704 			rcu_read_unlock();
1705 
1706 			return 0;
1707 		}
1708 		rcu_read_unlock();
1709 		return -EADDRNOTAVAIL;
1710 	case SIOCGETSGCNT:
1711 		sr = (struct sioc_sg_req *)arg;
1712 
1713 		rcu_read_lock();
1714 		c = ipmr_cache_find(mrt, sr->src.s_addr, sr->grp.s_addr);
1715 		if (c) {
1716 			sr->pktcnt = atomic_long_read(&c->_c.mfc_un.res.pkt);
1717 			sr->bytecnt = atomic_long_read(&c->_c.mfc_un.res.bytes);
1718 			sr->wrong_if = atomic_long_read(&c->_c.mfc_un.res.wrong_if);
1719 			rcu_read_unlock();
1720 			return 0;
1721 		}
1722 		rcu_read_unlock();
1723 		return -EADDRNOTAVAIL;
1724 	default:
1725 		return -ENOIOCTLCMD;
1726 	}
1727 }
1728 
1729 #ifdef CONFIG_COMPAT
1730 struct compat_sioc_sg_req {
1731 	struct in_addr src;
1732 	struct in_addr grp;
1733 	compat_ulong_t pktcnt;
1734 	compat_ulong_t bytecnt;
1735 	compat_ulong_t wrong_if;
1736 };
1737 
1738 struct compat_sioc_vif_req {
1739 	vifi_t	vifi;		/* Which iface */
1740 	compat_ulong_t icount;
1741 	compat_ulong_t ocount;
1742 	compat_ulong_t ibytes;
1743 	compat_ulong_t obytes;
1744 };
1745 
1746 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1747 {
1748 	struct compat_sioc_sg_req sr;
1749 	struct compat_sioc_vif_req vr;
1750 	struct vif_device *vif;
1751 	struct mfc_cache *c;
1752 	struct net *net = sock_net(sk);
1753 	struct mr_table *mrt;
1754 
1755 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1756 	if (!mrt)
1757 		return -ENOENT;
1758 
1759 	switch (cmd) {
1760 	case SIOCGETVIFCNT:
1761 		if (copy_from_user(&vr, arg, sizeof(vr)))
1762 			return -EFAULT;
1763 		if (vr.vifi >= mrt->maxvif)
1764 			return -EINVAL;
1765 		vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif);
1766 		rcu_read_lock();
1767 		vif = &mrt->vif_table[vr.vifi];
1768 		if (VIF_EXISTS(mrt, vr.vifi)) {
1769 			vr.icount = READ_ONCE(vif->pkt_in);
1770 			vr.ocount = READ_ONCE(vif->pkt_out);
1771 			vr.ibytes = READ_ONCE(vif->bytes_in);
1772 			vr.obytes = READ_ONCE(vif->bytes_out);
1773 			rcu_read_unlock();
1774 
1775 			if (copy_to_user(arg, &vr, sizeof(vr)))
1776 				return -EFAULT;
1777 			return 0;
1778 		}
1779 		rcu_read_unlock();
1780 		return -EADDRNOTAVAIL;
1781 	case SIOCGETSGCNT:
1782 		if (copy_from_user(&sr, arg, sizeof(sr)))
1783 			return -EFAULT;
1784 
1785 		rcu_read_lock();
1786 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1787 		if (c) {
1788 			sr.pktcnt = atomic_long_read(&c->_c.mfc_un.res.pkt);
1789 			sr.bytecnt = atomic_long_read(&c->_c.mfc_un.res.bytes);
1790 			sr.wrong_if = atomic_long_read(&c->_c.mfc_un.res.wrong_if);
1791 			rcu_read_unlock();
1792 
1793 			if (copy_to_user(arg, &sr, sizeof(sr)))
1794 				return -EFAULT;
1795 			return 0;
1796 		}
1797 		rcu_read_unlock();
1798 		return -EADDRNOTAVAIL;
1799 	default:
1800 		return -ENOIOCTLCMD;
1801 	}
1802 }
1803 #endif
1804 
1805 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1806 {
1807 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1808 	struct net *net = dev_net(dev);
1809 	struct mr_table *mrt;
1810 	struct vif_device *v;
1811 	int ct;
1812 
1813 	if (event != NETDEV_UNREGISTER)
1814 		return NOTIFY_DONE;
1815 
1816 	ipmr_for_each_table(mrt, net) {
1817 		v = &mrt->vif_table[0];
1818 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1819 			if (rcu_access_pointer(v->dev) == dev)
1820 				vif_delete(mrt, ct, 1, NULL);
1821 		}
1822 	}
1823 	return NOTIFY_DONE;
1824 }
1825 
1826 static struct notifier_block ip_mr_notifier = {
1827 	.notifier_call = ipmr_device_event,
1828 };
1829 
1830 /* Encapsulate a packet by attaching a valid IPIP header to it.
1831  * This avoids tunnel drivers and other mess and gives us the speed so
1832  * important for multicast video.
1833  */
1834 static void ip_encap(struct net *net, struct sk_buff *skb,
1835 		     __be32 saddr, __be32 daddr)
1836 {
1837 	struct iphdr *iph;
1838 	const struct iphdr *old_iph = ip_hdr(skb);
1839 
1840 	skb_push(skb, sizeof(struct iphdr));
1841 	skb->transport_header = skb->network_header;
1842 	skb_reset_network_header(skb);
1843 	iph = ip_hdr(skb);
1844 
1845 	iph->version	=	4;
1846 	iph->tos	=	old_iph->tos;
1847 	iph->ttl	=	old_iph->ttl;
1848 	iph->frag_off	=	0;
1849 	iph->daddr	=	daddr;
1850 	iph->saddr	=	saddr;
1851 	iph->protocol	=	IPPROTO_IPIP;
1852 	iph->ihl	=	5;
1853 	iph->tot_len	=	htons(skb->len);
1854 	ip_select_ident(net, skb, NULL);
1855 	ip_send_check(iph);
1856 
1857 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1858 	nf_reset_ct(skb);
1859 }
1860 
1861 static inline int ipmr_forward_finish(struct net *net, struct sock *sk,
1862 				      struct sk_buff *skb)
1863 {
1864 	struct ip_options *opt = &(IPCB(skb)->opt);
1865 
1866 	IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
1867 
1868 	if (unlikely(opt->optlen))
1869 		ip_forward_options(skb);
1870 
1871 	return dst_output(net, sk, skb);
1872 }
1873 
1874 #ifdef CONFIG_NET_SWITCHDEV
1875 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1876 				   int in_vifi, int out_vifi)
1877 {
1878 	struct vif_device *out_vif = &mrt->vif_table[out_vifi];
1879 	struct vif_device *in_vif = &mrt->vif_table[in_vifi];
1880 
1881 	if (!skb->offload_l3_fwd_mark)
1882 		return false;
1883 	if (!out_vif->dev_parent_id.id_len || !in_vif->dev_parent_id.id_len)
1884 		return false;
1885 	return netdev_phys_item_id_same(&out_vif->dev_parent_id,
1886 					&in_vif->dev_parent_id);
1887 }
1888 #else
1889 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1890 				   int in_vifi, int out_vifi)
1891 {
1892 	return false;
1893 }
1894 #endif
1895 
1896 /* Processing handlers for ipmr_forward, under rcu_read_lock() */
1897 
1898 static int ipmr_prepare_xmit(struct net *net, struct mr_table *mrt,
1899 			     struct sk_buff *skb, int vifi)
1900 {
1901 	const struct iphdr *iph = ip_hdr(skb);
1902 	struct vif_device *vif = &mrt->vif_table[vifi];
1903 	struct net_device *vif_dev;
1904 	struct rtable *rt;
1905 	struct flowi4 fl4;
1906 	int    encap = 0;
1907 
1908 	vif_dev = vif_dev_read(vif);
1909 	if (!vif_dev)
1910 		return -1;
1911 
1912 	if (vif->flags & VIFF_REGISTER) {
1913 		WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
1914 		WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len);
1915 		DEV_STATS_ADD(vif_dev, tx_bytes, skb->len);
1916 		DEV_STATS_INC(vif_dev, tx_packets);
1917 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1918 		return -1;
1919 	}
1920 
1921 	if (vif->flags & VIFF_TUNNEL) {
1922 		rt = ip_route_output_ports(net, &fl4, NULL,
1923 					   vif->remote, vif->local,
1924 					   0, 0,
1925 					   IPPROTO_IPIP,
1926 					   iph->tos & INET_DSCP_MASK, vif->link);
1927 		if (IS_ERR(rt))
1928 			return -1;
1929 		encap = sizeof(struct iphdr);
1930 	} else {
1931 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1932 					   0, 0,
1933 					   IPPROTO_IPIP,
1934 					   iph->tos & INET_DSCP_MASK, vif->link);
1935 		if (IS_ERR(rt))
1936 			return -1;
1937 	}
1938 
1939 	if (skb->len+encap > dst4_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1940 		/* Do not fragment multicasts. Alas, IPv4 does not
1941 		 * allow to send ICMP, so that packets will disappear
1942 		 * to blackhole.
1943 		 */
1944 		IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
1945 		ip_rt_put(rt);
1946 		return -1;
1947 	}
1948 
1949 	encap += LL_RESERVED_SPACE(dst_dev_rcu(&rt->dst)) + rt->dst.header_len;
1950 
1951 	if (skb_cow(skb, encap)) {
1952 		ip_rt_put(rt);
1953 		return -1;
1954 	}
1955 
1956 	WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
1957 	WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len);
1958 
1959 	skb_dst_drop(skb);
1960 	skb_dst_set(skb, &rt->dst);
1961 	ip_decrease_ttl(ip_hdr(skb));
1962 
1963 	/* FIXME: forward and output firewalls used to be called here.
1964 	 * What do we do with netfilter? -- RR
1965 	 */
1966 	if (vif->flags & VIFF_TUNNEL) {
1967 		ip_encap(net, skb, vif->local, vif->remote);
1968 		/* FIXME: extra output firewall step used to be here. --RR */
1969 		DEV_STATS_INC(vif_dev, tx_packets);
1970 		DEV_STATS_ADD(vif_dev, tx_bytes, skb->len);
1971 	}
1972 
1973 	return 0;
1974 }
1975 
1976 static void ipmr_queue_fwd_xmit(struct net *net, struct mr_table *mrt,
1977 				int in_vifi, struct sk_buff *skb, int vifi)
1978 {
1979 	struct rtable *rt;
1980 
1981 	if (ipmr_forward_offloaded(skb, mrt, in_vifi, vifi))
1982 		goto out_free;
1983 
1984 	if (ipmr_prepare_xmit(net, mrt, skb, vifi))
1985 		goto out_free;
1986 
1987 	rt = skb_rtable(skb);
1988 
1989 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1990 
1991 	/* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1992 	 * not only before forwarding, but after forwarding on all output
1993 	 * interfaces. It is clear, if mrouter runs a multicasting
1994 	 * program, it should receive packets not depending to what interface
1995 	 * program is joined.
1996 	 * If we will not make it, the program will have to join on all
1997 	 * interfaces. On the other hand, multihoming host (or router, but
1998 	 * not mrouter) cannot join to more than one interface - it will
1999 	 * result in receiving multiple packets.
2000 	 */
2001 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
2002 		net, NULL, skb, skb->dev, dst_dev_rcu(&rt->dst),
2003 		ipmr_forward_finish);
2004 	return;
2005 
2006 out_free:
2007 	kfree_skb(skb);
2008 }
2009 
2010 static void ipmr_queue_output_xmit(struct net *net, struct mr_table *mrt,
2011 				   struct sk_buff *skb, int vifi)
2012 {
2013 	if (ipmr_prepare_xmit(net, mrt, skb, vifi))
2014 		goto out_free;
2015 
2016 	ip_mc_output(net, NULL, skb);
2017 	return;
2018 
2019 out_free:
2020 	kfree_skb(skb);
2021 }
2022 
2023 /* Called with mrt_lock or rcu_read_lock() */
2024 static int ipmr_find_vif(const struct mr_table *mrt, struct net_device *dev)
2025 {
2026 	int ct;
2027 	/* Pairs with WRITE_ONCE() in vif_delete()/vif_add() */
2028 	for (ct = READ_ONCE(mrt->maxvif) - 1; ct >= 0; ct--) {
2029 		if (rcu_access_pointer(mrt->vif_table[ct].dev) == dev)
2030 			break;
2031 	}
2032 	return ct;
2033 }
2034 
2035 /* "local" means that we should preserve one skb (for local delivery) */
2036 /* Called uner rcu_read_lock() */
2037 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
2038 			  struct net_device *dev, struct sk_buff *skb,
2039 			  struct mfc_cache *c, int local)
2040 {
2041 	int true_vifi = ipmr_find_vif(mrt, dev);
2042 	int psend = -1;
2043 	int vif, ct;
2044 
2045 	vif = c->_c.mfc_parent;
2046 	atomic_long_inc(&c->_c.mfc_un.res.pkt);
2047 	atomic_long_add(skb->len, &c->_c.mfc_un.res.bytes);
2048 	WRITE_ONCE(c->_c.mfc_un.res.lastuse, jiffies);
2049 
2050 	if (c->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
2051 		struct mfc_cache *cache_proxy;
2052 
2053 		/* For an (*,G) entry, we only check that the incoming
2054 		 * interface is part of the static tree.
2055 		 */
2056 		cache_proxy = mr_mfc_find_any_parent(mrt, vif);
2057 		if (cache_proxy &&
2058 		    cache_proxy->_c.mfc_un.res.ttls[true_vifi] < 255)
2059 			goto forward;
2060 	}
2061 
2062 	/* Wrong interface: drop packet and (maybe) send PIM assert. */
2063 	if (rcu_access_pointer(mrt->vif_table[vif].dev) != dev) {
2064 		if (rt_is_output_route(skb_rtable(skb))) {
2065 			/* It is our own packet, looped back.
2066 			 * Very complicated situation...
2067 			 *
2068 			 * The best workaround until routing daemons will be
2069 			 * fixed is not to redistribute packet, if it was
2070 			 * send through wrong interface. It means, that
2071 			 * multicast applications WILL NOT work for
2072 			 * (S,G), which have default multicast route pointing
2073 			 * to wrong oif. In any case, it is not a good
2074 			 * idea to use multicasting applications on router.
2075 			 */
2076 			goto dont_forward;
2077 		}
2078 
2079 		atomic_long_inc(&c->_c.mfc_un.res.wrong_if);
2080 
2081 		if (true_vifi >= 0 && READ_ONCE(mrt->mroute_do_assert) &&
2082 		    /* pimsm uses asserts, when switching from RPT to SPT,
2083 		     * so that we cannot check that packet arrived on an oif.
2084 		     * It is bad, but otherwise we would need to move pretty
2085 		     * large chunk of pimd to kernel. Ough... --ANK
2086 		     */
2087 		    (READ_ONCE(mrt->mroute_do_pim) ||
2088 		     c->_c.mfc_un.res.ttls[true_vifi] < 255) &&
2089 		    time_after(jiffies,
2090 			       c->_c.mfc_un.res.last_assert +
2091 			       MFC_ASSERT_THRESH)) {
2092 			c->_c.mfc_un.res.last_assert = jiffies;
2093 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
2094 			if (READ_ONCE(mrt->mroute_do_wrvifwhole))
2095 				ipmr_cache_report(mrt, skb, true_vifi,
2096 						  IGMPMSG_WRVIFWHOLE);
2097 		}
2098 		goto dont_forward;
2099 	}
2100 
2101 forward:
2102 	WRITE_ONCE(mrt->vif_table[vif].pkt_in,
2103 		   mrt->vif_table[vif].pkt_in + 1);
2104 	WRITE_ONCE(mrt->vif_table[vif].bytes_in,
2105 		   mrt->vif_table[vif].bytes_in + skb->len);
2106 
2107 	/* Forward the frame */
2108 	if (c->mfc_origin == htonl(INADDR_ANY) &&
2109 	    c->mfc_mcastgrp == htonl(INADDR_ANY)) {
2110 		if (true_vifi >= 0 &&
2111 		    true_vifi != c->_c.mfc_parent &&
2112 		    ip_hdr(skb)->ttl >
2113 				c->_c.mfc_un.res.ttls[c->_c.mfc_parent]) {
2114 			/* It's an (*,*) entry and the packet is not coming from
2115 			 * the upstream: forward the packet to the upstream
2116 			 * only.
2117 			 */
2118 			psend = c->_c.mfc_parent;
2119 			goto last_forward;
2120 		}
2121 		goto dont_forward;
2122 	}
2123 	for (ct = c->_c.mfc_un.res.maxvif - 1;
2124 	     ct >= c->_c.mfc_un.res.minvif; ct--) {
2125 		/* For (*,G) entry, don't forward to the incoming interface */
2126 		if ((c->mfc_origin != htonl(INADDR_ANY) ||
2127 		     ct != true_vifi) &&
2128 		    ip_hdr(skb)->ttl > c->_c.mfc_un.res.ttls[ct]) {
2129 			if (psend != -1) {
2130 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2131 
2132 				if (skb2)
2133 					ipmr_queue_fwd_xmit(net, mrt, true_vifi,
2134 							    skb2, psend);
2135 			}
2136 			psend = ct;
2137 		}
2138 	}
2139 last_forward:
2140 	if (psend != -1) {
2141 		if (local) {
2142 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2143 
2144 			if (skb2)
2145 				ipmr_queue_fwd_xmit(net, mrt, true_vifi, skb2,
2146 						    psend);
2147 		} else {
2148 			ipmr_queue_fwd_xmit(net, mrt, true_vifi, skb, psend);
2149 			return;
2150 		}
2151 	}
2152 
2153 dont_forward:
2154 	if (!local)
2155 		kfree_skb(skb);
2156 }
2157 
2158 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
2159 {
2160 	struct rtable *rt = skb_rtable(skb);
2161 	struct iphdr *iph = ip_hdr(skb);
2162 	struct flowi4 fl4 = {
2163 		.daddr = iph->daddr,
2164 		.saddr = iph->saddr,
2165 		.flowi4_dscp = ip4h_dscp(iph),
2166 		.flowi4_oif = (rt_is_output_route(rt) ?
2167 			       skb->dev->ifindex : 0),
2168 		.flowi4_iif = (rt_is_output_route(rt) ?
2169 			       LOOPBACK_IFINDEX :
2170 			       skb->dev->ifindex),
2171 		.flowi4_mark = skb->mark,
2172 	};
2173 	struct mr_table *mrt;
2174 	int err;
2175 
2176 	err = ipmr_fib_lookup(net, &fl4, &mrt);
2177 	if (err)
2178 		return ERR_PTR(err);
2179 	return mrt;
2180 }
2181 
2182 /* Multicast packets for forwarding arrive here
2183  * Called with rcu_read_lock();
2184  */
2185 int ip_mr_input(struct sk_buff *skb)
2186 {
2187 	struct mfc_cache *cache;
2188 	struct net *net = dev_net(skb->dev);
2189 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
2190 	struct mr_table *mrt;
2191 	struct net_device *dev;
2192 
2193 	/* skb->dev passed in is the loX master dev for vrfs.
2194 	 * As there are no vifs associated with loopback devices,
2195 	 * get the proper interface that does have a vif associated with it.
2196 	 */
2197 	dev = skb->dev;
2198 	if (netif_is_l3_master(skb->dev)) {
2199 		dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
2200 		if (!dev) {
2201 			kfree_skb(skb);
2202 			return -ENODEV;
2203 		}
2204 	}
2205 
2206 	/* Packet is looped back after forward, it should not be
2207 	 * forwarded second time, but still can be delivered locally.
2208 	 */
2209 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
2210 		goto dont_forward;
2211 
2212 	mrt = ipmr_rt_fib_lookup(net, skb);
2213 	if (IS_ERR(mrt)) {
2214 		kfree_skb(skb);
2215 		return PTR_ERR(mrt);
2216 	}
2217 	if (!local) {
2218 		if (IPCB(skb)->opt.router_alert) {
2219 			if (ip_call_ra_chain(skb))
2220 				return 0;
2221 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
2222 			/* IGMPv1 (and broken IGMPv2 implementations sort of
2223 			 * Cisco IOS <= 11.2(8)) do not put router alert
2224 			 * option to IGMP packets destined to routable
2225 			 * groups. It is very bad, because it means
2226 			 * that we can forward NO IGMP messages.
2227 			 */
2228 			struct sock *mroute_sk;
2229 
2230 			mroute_sk = rcu_dereference(mrt->mroute_sk);
2231 			if (mroute_sk) {
2232 				nf_reset_ct(skb);
2233 				raw_rcv(mroute_sk, skb);
2234 				return 0;
2235 			}
2236 		}
2237 	}
2238 
2239 	/* already under rcu_read_lock() */
2240 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
2241 	if (!cache) {
2242 		int vif = ipmr_find_vif(mrt, dev);
2243 
2244 		if (vif >= 0)
2245 			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
2246 						    vif);
2247 	}
2248 
2249 	/* No usable cache entry */
2250 	if (!cache) {
2251 		int vif;
2252 
2253 		if (local) {
2254 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2255 			ip_local_deliver(skb);
2256 			if (!skb2)
2257 				return -ENOBUFS;
2258 			skb = skb2;
2259 		}
2260 
2261 		vif = ipmr_find_vif(mrt, dev);
2262 		if (vif >= 0)
2263 			return ipmr_cache_unresolved(mrt, vif, skb, dev);
2264 		kfree_skb(skb);
2265 		return -ENODEV;
2266 	}
2267 
2268 	ip_mr_forward(net, mrt, dev, skb, cache, local);
2269 
2270 	if (local)
2271 		return ip_local_deliver(skb);
2272 
2273 	return 0;
2274 
2275 dont_forward:
2276 	if (local)
2277 		return ip_local_deliver(skb);
2278 	kfree_skb(skb);
2279 	return 0;
2280 }
2281 
2282 static void ip_mr_output_finish(struct net *net, struct mr_table *mrt,
2283 				struct net_device *dev, struct sk_buff *skb,
2284 				struct mfc_cache *c)
2285 {
2286 	int psend = -1;
2287 	int ct;
2288 
2289 	atomic_long_inc(&c->_c.mfc_un.res.pkt);
2290 	atomic_long_add(skb->len, &c->_c.mfc_un.res.bytes);
2291 	WRITE_ONCE(c->_c.mfc_un.res.lastuse, jiffies);
2292 
2293 	/* Forward the frame */
2294 	if (c->mfc_origin == htonl(INADDR_ANY) &&
2295 	    c->mfc_mcastgrp == htonl(INADDR_ANY)) {
2296 		if (ip_hdr(skb)->ttl >
2297 		    c->_c.mfc_un.res.ttls[c->_c.mfc_parent]) {
2298 			/* It's an (*,*) entry and the packet is not coming from
2299 			 * the upstream: forward the packet to the upstream
2300 			 * only.
2301 			 */
2302 			psend = c->_c.mfc_parent;
2303 			goto last_xmit;
2304 		}
2305 		goto dont_xmit;
2306 	}
2307 
2308 	for (ct = c->_c.mfc_un.res.maxvif - 1;
2309 	     ct >= c->_c.mfc_un.res.minvif; ct--) {
2310 		if (ip_hdr(skb)->ttl > c->_c.mfc_un.res.ttls[ct]) {
2311 			if (psend != -1) {
2312 				struct sk_buff *skb2;
2313 
2314 				skb2 = skb_clone(skb, GFP_ATOMIC);
2315 				if (skb2)
2316 					ipmr_queue_output_xmit(net, mrt,
2317 							       skb2, psend);
2318 			}
2319 			psend = ct;
2320 		}
2321 	}
2322 
2323 last_xmit:
2324 	if (psend != -1) {
2325 		ipmr_queue_output_xmit(net, mrt, skb, psend);
2326 		return;
2327 	}
2328 
2329 dont_xmit:
2330 	kfree_skb(skb);
2331 }
2332 
2333 /* Multicast packets for forwarding arrive here
2334  * Called with rcu_read_lock();
2335  */
2336 int ip_mr_output(struct net *net, struct sock *sk, struct sk_buff *skb)
2337 {
2338 	struct rtable *rt = skb_rtable(skb);
2339 	struct mfc_cache *cache;
2340 	struct net_device *dev;
2341 	struct mr_table *mrt;
2342 	int vif;
2343 
2344 	guard(rcu)();
2345 
2346 	dev = dst_dev_rcu(&rt->dst);
2347 
2348 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
2349 		goto mc_output;
2350 	if (!(IPCB(skb)->flags & IPSKB_MCROUTE))
2351 		goto mc_output;
2352 
2353 	skb->dev = dev;
2354 
2355 	mrt = ipmr_rt_fib_lookup(net, skb);
2356 	if (IS_ERR(mrt))
2357 		goto mc_output;
2358 
2359 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
2360 	if (!cache) {
2361 		vif = ipmr_find_vif(mrt, dev);
2362 		if (vif >= 0)
2363 			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
2364 						    vif);
2365 	}
2366 
2367 	/* No usable cache entry */
2368 	if (!cache) {
2369 		vif = ipmr_find_vif(mrt, dev);
2370 		if (vif >= 0)
2371 			return ipmr_cache_unresolved(mrt, vif, skb, dev);
2372 		goto mc_output;
2373 	}
2374 
2375 	vif = cache->_c.mfc_parent;
2376 	if (rcu_access_pointer(mrt->vif_table[vif].dev) != dev)
2377 		goto mc_output;
2378 
2379 	ip_mr_output_finish(net, mrt, dev, skb, cache);
2380 	return 0;
2381 
2382 mc_output:
2383 	return ip_mc_output(net, sk, skb);
2384 }
2385 
2386 #ifdef CONFIG_IP_PIMSM_V1
2387 /* Handle IGMP messages of PIMv1 */
2388 int pim_rcv_v1(struct sk_buff *skb)
2389 {
2390 	struct igmphdr *pim;
2391 	struct net *net = dev_net(skb->dev);
2392 	struct mr_table *mrt;
2393 
2394 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2395 		goto drop;
2396 
2397 	pim = igmp_hdr(skb);
2398 
2399 	mrt = ipmr_rt_fib_lookup(net, skb);
2400 	if (IS_ERR(mrt))
2401 		goto drop;
2402 	if (!READ_ONCE(mrt->mroute_do_pim) ||
2403 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2404 		goto drop;
2405 
2406 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2407 drop:
2408 		kfree_skb(skb);
2409 	}
2410 	return 0;
2411 }
2412 #endif
2413 
2414 #ifdef CONFIG_IP_PIMSM_V2
2415 static int pim_rcv(struct sk_buff *skb)
2416 {
2417 	struct pimreghdr *pim;
2418 	struct net *net = dev_net(skb->dev);
2419 	struct mr_table *mrt;
2420 
2421 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2422 		goto drop;
2423 
2424 	pim = (struct pimreghdr *)skb_transport_header(skb);
2425 	if (pim->type != ((PIM_VERSION << 4) | (PIM_TYPE_REGISTER)) ||
2426 	    (pim->flags & PIM_NULL_REGISTER) ||
2427 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2428 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2429 		goto drop;
2430 
2431 	mrt = ipmr_rt_fib_lookup(net, skb);
2432 	if (IS_ERR(mrt))
2433 		goto drop;
2434 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2435 drop:
2436 		kfree_skb(skb);
2437 	}
2438 	return 0;
2439 }
2440 #endif
2441 
2442 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2443 		   __be32 saddr, __be32 daddr,
2444 		   struct rtmsg *rtm, u32 portid)
2445 {
2446 	struct mfc_cache *cache;
2447 	struct mr_table *mrt;
2448 	int err;
2449 
2450 	rcu_read_lock();
2451 	mrt = __ipmr_get_table(net, RT_TABLE_DEFAULT);
2452 	if (!mrt) {
2453 		rcu_read_unlock();
2454 		return -ENOENT;
2455 	}
2456 
2457 	cache = ipmr_cache_find(mrt, saddr, daddr);
2458 	if (!cache && skb->dev) {
2459 		int vif = ipmr_find_vif(mrt, skb->dev);
2460 
2461 		if (vif >= 0)
2462 			cache = ipmr_cache_find_any(mrt, daddr, vif);
2463 	}
2464 	if (!cache) {
2465 		struct sk_buff *skb2;
2466 		struct iphdr *iph;
2467 		struct net_device *dev;
2468 		int vif = -1;
2469 
2470 		dev = skb->dev;
2471 		if (dev)
2472 			vif = ipmr_find_vif(mrt, dev);
2473 		if (vif < 0) {
2474 			rcu_read_unlock();
2475 			return -ENODEV;
2476 		}
2477 
2478 		skb2 = skb_realloc_headroom(skb, sizeof(struct iphdr));
2479 		if (!skb2) {
2480 			rcu_read_unlock();
2481 			return -ENOMEM;
2482 		}
2483 
2484 		NETLINK_CB(skb2).portid = portid;
2485 		skb_push(skb2, sizeof(struct iphdr));
2486 		skb_reset_network_header(skb2);
2487 		iph = ip_hdr(skb2);
2488 		iph->ihl = sizeof(struct iphdr) >> 2;
2489 		iph->saddr = saddr;
2490 		iph->daddr = daddr;
2491 		iph->version = 0;
2492 		err = ipmr_cache_unresolved(mrt, vif, skb2, dev);
2493 		rcu_read_unlock();
2494 		return err;
2495 	}
2496 
2497 	err = mr_fill_mroute(mrt, skb, &cache->_c, rtm);
2498 	rcu_read_unlock();
2499 	return err;
2500 }
2501 
2502 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2503 			    u32 portid, u32 seq, struct mfc_cache *c, int cmd,
2504 			    int flags)
2505 {
2506 	struct nlmsghdr *nlh;
2507 	struct rtmsg *rtm;
2508 	int err;
2509 
2510 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2511 	if (!nlh)
2512 		return -EMSGSIZE;
2513 
2514 	rtm = nlmsg_data(nlh);
2515 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2516 	rtm->rtm_dst_len  = 32;
2517 	rtm->rtm_src_len  = 32;
2518 	rtm->rtm_tos      = 0;
2519 	rtm->rtm_table    = mrt->id;
2520 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2521 		goto nla_put_failure;
2522 	rtm->rtm_type     = RTN_MULTICAST;
2523 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2524 	if (c->_c.mfc_flags & MFC_STATIC)
2525 		rtm->rtm_protocol = RTPROT_STATIC;
2526 	else
2527 		rtm->rtm_protocol = RTPROT_MROUTED;
2528 	rtm->rtm_flags    = 0;
2529 
2530 	if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
2531 	    nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
2532 		goto nla_put_failure;
2533 	err = mr_fill_mroute(mrt, skb, &c->_c, rtm);
2534 	/* do not break the dump if cache is unresolved */
2535 	if (err < 0 && err != -ENOENT)
2536 		goto nla_put_failure;
2537 
2538 	nlmsg_end(skb, nlh);
2539 	return 0;
2540 
2541 nla_put_failure:
2542 	nlmsg_cancel(skb, nlh);
2543 	return -EMSGSIZE;
2544 }
2545 
2546 static int _ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2547 			     u32 portid, u32 seq, struct mr_mfc *c, int cmd,
2548 			     int flags)
2549 {
2550 	return ipmr_fill_mroute(mrt, skb, portid, seq, (struct mfc_cache *)c,
2551 				cmd, flags);
2552 }
2553 
2554 static size_t mroute_msgsize(bool unresolved)
2555 {
2556 	size_t len =
2557 		NLMSG_ALIGN(sizeof(struct rtmsg))
2558 		+ nla_total_size(4)	/* RTA_TABLE */
2559 		+ nla_total_size(4)	/* RTA_SRC */
2560 		+ nla_total_size(4)	/* RTA_DST */
2561 		;
2562 
2563 	if (!unresolved)
2564 		len = len
2565 		      + nla_total_size(4)	/* RTA_IIF */
2566 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2567 		      + MAXVIFS * NLA_ALIGN(sizeof(struct rtnexthop))
2568 						/* RTA_MFC_STATS */
2569 		      + nla_total_size_64bit(sizeof(struct rta_mfc_stats))
2570 		;
2571 
2572 	return len;
2573 }
2574 
2575 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2576 				 int cmd)
2577 {
2578 	struct net *net = read_pnet(&mrt->net);
2579 	struct sk_buff *skb;
2580 	int err = -ENOBUFS;
2581 
2582 	skb = nlmsg_new(mroute_msgsize(mfc->_c.mfc_parent >= MAXVIFS),
2583 			GFP_ATOMIC);
2584 	if (!skb)
2585 		goto errout;
2586 
2587 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2588 	if (err < 0)
2589 		goto errout;
2590 
2591 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2592 	return;
2593 
2594 errout:
2595 	kfree_skb(skb);
2596 	rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2597 }
2598 
2599 static size_t igmpmsg_netlink_msgsize(size_t payloadlen)
2600 {
2601 	size_t len =
2602 		NLMSG_ALIGN(sizeof(struct rtgenmsg))
2603 		+ nla_total_size(1)	/* IPMRA_CREPORT_MSGTYPE */
2604 		+ nla_total_size(4)	/* IPMRA_CREPORT_VIF_ID */
2605 		+ nla_total_size(4)	/* IPMRA_CREPORT_SRC_ADDR */
2606 		+ nla_total_size(4)	/* IPMRA_CREPORT_DST_ADDR */
2607 		+ nla_total_size(4)	/* IPMRA_CREPORT_TABLE */
2608 					/* IPMRA_CREPORT_PKT */
2609 		+ nla_total_size(payloadlen)
2610 		;
2611 
2612 	return len;
2613 }
2614 
2615 static void igmpmsg_netlink_event(const struct mr_table *mrt, struct sk_buff *pkt)
2616 {
2617 	struct net *net = read_pnet(&mrt->net);
2618 	struct nlmsghdr *nlh;
2619 	struct rtgenmsg *rtgenm;
2620 	struct igmpmsg *msg;
2621 	struct sk_buff *skb;
2622 	struct nlattr *nla;
2623 	int payloadlen;
2624 
2625 	payloadlen = pkt->len - sizeof(struct igmpmsg);
2626 	msg = (struct igmpmsg *)skb_network_header(pkt);
2627 
2628 	skb = nlmsg_new(igmpmsg_netlink_msgsize(payloadlen), GFP_ATOMIC);
2629 	if (!skb)
2630 		goto errout;
2631 
2632 	nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT,
2633 			sizeof(struct rtgenmsg), 0);
2634 	if (!nlh)
2635 		goto errout;
2636 	rtgenm = nlmsg_data(nlh);
2637 	rtgenm->rtgen_family = RTNL_FAMILY_IPMR;
2638 	if (nla_put_u8(skb, IPMRA_CREPORT_MSGTYPE, msg->im_msgtype) ||
2639 	    nla_put_u32(skb, IPMRA_CREPORT_VIF_ID, msg->im_vif | (msg->im_vif_hi << 8)) ||
2640 	    nla_put_in_addr(skb, IPMRA_CREPORT_SRC_ADDR,
2641 			    msg->im_src.s_addr) ||
2642 	    nla_put_in_addr(skb, IPMRA_CREPORT_DST_ADDR,
2643 			    msg->im_dst.s_addr) ||
2644 	    nla_put_u32(skb, IPMRA_CREPORT_TABLE, mrt->id))
2645 		goto nla_put_failure;
2646 
2647 	nla = nla_reserve(skb, IPMRA_CREPORT_PKT, payloadlen);
2648 	if (!nla || skb_copy_bits(pkt, sizeof(struct igmpmsg),
2649 				  nla_data(nla), payloadlen))
2650 		goto nla_put_failure;
2651 
2652 	nlmsg_end(skb, nlh);
2653 
2654 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE_R, NULL, GFP_ATOMIC);
2655 	return;
2656 
2657 nla_put_failure:
2658 	nlmsg_cancel(skb, nlh);
2659 errout:
2660 	kfree_skb(skb);
2661 	rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE_R, -ENOBUFS);
2662 }
2663 
2664 static int ipmr_rtm_valid_getroute_req(struct sk_buff *skb,
2665 				       const struct nlmsghdr *nlh,
2666 				       struct nlattr **tb,
2667 				       struct netlink_ext_ack *extack)
2668 {
2669 	struct rtmsg *rtm;
2670 	int i, err;
2671 
2672 	rtm = nlmsg_payload(nlh, sizeof(*rtm));
2673 	if (!rtm) {
2674 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for multicast route get request");
2675 		return -EINVAL;
2676 	}
2677 
2678 	if (!netlink_strict_get_check(skb))
2679 		return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
2680 					      rtm_ipv4_policy, extack);
2681 
2682 	if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
2683 	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
2684 	    rtm->rtm_tos || rtm->rtm_table || rtm->rtm_protocol ||
2685 	    rtm->rtm_scope || rtm->rtm_type || rtm->rtm_flags) {
2686 		NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for multicast route get request");
2687 		return -EINVAL;
2688 	}
2689 
2690 	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2691 					    rtm_ipv4_policy, extack);
2692 	if (err)
2693 		return err;
2694 
2695 	if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
2696 	    (tb[RTA_DST] && !rtm->rtm_dst_len)) {
2697 		NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
2698 		return -EINVAL;
2699 	}
2700 
2701 	for (i = 0; i <= RTA_MAX; i++) {
2702 		if (!tb[i])
2703 			continue;
2704 
2705 		switch (i) {
2706 		case RTA_SRC:
2707 		case RTA_DST:
2708 		case RTA_TABLE:
2709 			break;
2710 		default:
2711 			NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in multicast route get request");
2712 			return -EINVAL;
2713 		}
2714 	}
2715 
2716 	return 0;
2717 }
2718 
2719 static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2720 			     struct netlink_ext_ack *extack)
2721 {
2722 	struct net *net = sock_net(in_skb->sk);
2723 	struct nlattr *tb[RTA_MAX + 1];
2724 	struct mfc_cache *cache;
2725 	struct mr_table *mrt;
2726 	struct sk_buff *skb;
2727 	__be32 src, grp;
2728 	u32 tableid;
2729 	int err;
2730 
2731 	err = ipmr_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
2732 	if (err < 0)
2733 		goto errout;
2734 
2735 	src = nla_get_in_addr_default(tb[RTA_SRC], 0);
2736 	grp = nla_get_in_addr_default(tb[RTA_DST], 0);
2737 	tableid = nla_get_u32_default(tb[RTA_TABLE], 0);
2738 
2739 	skb = nlmsg_new(mroute_msgsize(false), GFP_KERNEL);
2740 	if (!skb) {
2741 		err = -ENOBUFS;
2742 		goto errout;
2743 	}
2744 
2745 	rcu_read_lock();
2746 
2747 	mrt = __ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT);
2748 	if (!mrt) {
2749 		err = -ENOENT;
2750 		goto errout_unlock;
2751 	}
2752 
2753 	cache = ipmr_cache_find(mrt, src, grp);
2754 	if (!cache) {
2755 		err = -ENOENT;
2756 		goto errout_unlock;
2757 	}
2758 
2759 	err = ipmr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid,
2760 			       nlh->nlmsg_seq, cache,
2761 			       RTM_NEWROUTE, 0);
2762 	if (err < 0)
2763 		goto errout_unlock;
2764 
2765 	rcu_read_unlock();
2766 
2767 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2768 errout:
2769 	return err;
2770 
2771 errout_unlock:
2772 	rcu_read_unlock();
2773 	kfree_skb(skb);
2774 	goto errout;
2775 }
2776 
2777 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2778 {
2779 	struct fib_dump_filter filter = {
2780 		.rtnl_held = false,
2781 	};
2782 	int err;
2783 
2784 	rcu_read_lock();
2785 
2786 	if (cb->strict_check) {
2787 		err = ip_valid_fib_dump_req(sock_net(skb->sk), cb->nlh,
2788 					    &filter, cb);
2789 		if (err < 0)
2790 			goto out;
2791 	}
2792 
2793 	if (filter.table_id) {
2794 		struct mr_table *mrt;
2795 
2796 		mrt = __ipmr_get_table(sock_net(skb->sk), filter.table_id);
2797 		if (!mrt) {
2798 			if (rtnl_msg_family(cb->nlh) != RTNL_FAMILY_IPMR) {
2799 				err = skb->len;
2800 				goto out;
2801 			}
2802 
2803 			NL_SET_ERR_MSG(cb->extack, "ipv4: MR table does not exist");
2804 			err = -ENOENT;
2805 			goto out;
2806 		}
2807 
2808 		err = mr_table_dump(mrt, skb, cb, _ipmr_fill_mroute,
2809 				    &mfc_unres_lock, &filter);
2810 		err = skb->len ? : err;
2811 		goto out;
2812 	}
2813 
2814 	err = mr_rtm_dumproute(skb, cb, ipmr_mr_table_iter,
2815 			       _ipmr_fill_mroute, &mfc_unres_lock, &filter);
2816 out:
2817 	rcu_read_unlock();
2818 
2819 	return err;
2820 }
2821 
2822 static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {
2823 	[RTA_SRC]	= { .type = NLA_U32 },
2824 	[RTA_DST]	= { .type = NLA_U32 },
2825 	[RTA_IIF]	= { .type = NLA_U32 },
2826 	[RTA_TABLE]	= { .type = NLA_U32 },
2827 	[RTA_MULTIPATH]	= { .len = sizeof(struct rtnexthop) },
2828 };
2829 
2830 static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol)
2831 {
2832 	switch (rtm_protocol) {
2833 	case RTPROT_STATIC:
2834 	case RTPROT_MROUTED:
2835 		return true;
2836 	}
2837 	return false;
2838 }
2839 
2840 static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc)
2841 {
2842 	struct rtnexthop *rtnh = nla_data(nla);
2843 	int remaining = nla_len(nla), vifi = 0;
2844 
2845 	while (rtnh_ok(rtnh, remaining)) {
2846 		mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops;
2847 		if (++vifi == MAXVIFS)
2848 			break;
2849 		rtnh = rtnh_next(rtnh, &remaining);
2850 	}
2851 
2852 	return remaining > 0 ? -EINVAL : vifi;
2853 }
2854 
2855 /* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */
2856 static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
2857 			    struct mfcctl *mfcc, int *mrtsock,
2858 			    struct mr_table **mrtret,
2859 			    struct netlink_ext_ack *extack)
2860 {
2861 	struct net_device *dev = NULL;
2862 	u32 tblid = RT_TABLE_DEFAULT;
2863 	int ret, rem, iif = 0;
2864 	struct mr_table *mrt;
2865 	struct nlattr *attr;
2866 	struct rtmsg *rtm;
2867 
2868 	ret = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
2869 					rtm_ipmr_policy, extack);
2870 	if (ret < 0)
2871 		goto out;
2872 	rtm = nlmsg_data(nlh);
2873 
2874 	ret = -EINVAL;
2875 	if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 ||
2876 	    rtm->rtm_type != RTN_MULTICAST ||
2877 	    rtm->rtm_scope != RT_SCOPE_UNIVERSE ||
2878 	    !ipmr_rtm_validate_proto(rtm->rtm_protocol))
2879 		goto out;
2880 
2881 	memset(mfcc, 0, sizeof(*mfcc));
2882 	mfcc->mfcc_parent = -1;
2883 	ret = 0;
2884 	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) {
2885 		switch (nla_type(attr)) {
2886 		case RTA_SRC:
2887 			mfcc->mfcc_origin.s_addr = nla_get_be32(attr);
2888 			break;
2889 		case RTA_DST:
2890 			mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr);
2891 			break;
2892 		case RTA_IIF:
2893 			iif = nla_get_u32(attr);
2894 			break;
2895 		case RTA_MULTIPATH:
2896 			if (ipmr_nla_get_ttls(attr, mfcc) < 0) {
2897 				ret = -EINVAL;
2898 				goto out;
2899 			}
2900 			break;
2901 		case RTA_PREFSRC:
2902 			ret = 1;
2903 			break;
2904 		case RTA_TABLE:
2905 			tblid = nla_get_u32(attr);
2906 			break;
2907 		}
2908 	}
2909 
2910 	rcu_read_lock();
2911 
2912 	mrt = __ipmr_get_table(net, tblid);
2913 	if (!mrt) {
2914 		ret = -ENOENT;
2915 		goto unlock;
2916 	}
2917 
2918 	if (iif) {
2919 		dev = dev_get_by_index_rcu(net, iif);
2920 		if (!dev) {
2921 			ret = -ENODEV;
2922 			goto unlock;
2923 		}
2924 
2925 		mfcc->mfcc_parent = ipmr_find_vif(mrt, dev);
2926 	}
2927 
2928 	*mrtret = mrt;
2929 	*mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0;
2930 
2931 unlock:
2932 	rcu_read_unlock();
2933 out:
2934 	return ret;
2935 }
2936 
2937 /* takes care of both newroute and delroute */
2938 static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh,
2939 			  struct netlink_ext_ack *extack)
2940 {
2941 	struct net *net = sock_net(skb->sk);
2942 	int ret, mrtsock = 0, parent;
2943 	struct mr_table *tbl = NULL;
2944 	struct mfcctl mfcc;
2945 
2946 	ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl, extack);
2947 	if (ret < 0)
2948 		return ret;
2949 
2950 	parent = ret ? mfcc.mfcc_parent : -1;
2951 
2952 	mutex_lock(&net->ipv4.mfc_mutex);
2953 
2954 	if (nlh->nlmsg_type == RTM_NEWROUTE)
2955 		ret = ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent);
2956 	else
2957 		ret = ipmr_mfc_delete(tbl, &mfcc, parent);
2958 
2959 	mutex_unlock(&net->ipv4.mfc_mutex);
2960 
2961 	return ret;
2962 }
2963 
2964 static bool ipmr_fill_table(struct mr_table *mrt, struct sk_buff *skb)
2965 {
2966 	u32 queue_len = atomic_read(&mrt->cache_resolve_queue_len);
2967 
2968 	if (nla_put_u32(skb, IPMRA_TABLE_ID, mrt->id) ||
2969 	    nla_put_u32(skb, IPMRA_TABLE_CACHE_RES_QUEUE_LEN, queue_len) ||
2970 	    nla_put_s32(skb, IPMRA_TABLE_MROUTE_REG_VIF_NUM,
2971 			READ_ONCE(mrt->mroute_reg_vif_num)) ||
2972 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_ASSERT,
2973 		       READ_ONCE(mrt->mroute_do_assert)) ||
2974 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_PIM,
2975 		       READ_ONCE(mrt->mroute_do_pim)) ||
2976 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_WRVIFWHOLE,
2977 		       READ_ONCE(mrt->mroute_do_wrvifwhole)))
2978 		return false;
2979 
2980 	return true;
2981 }
2982 
2983 static bool ipmr_fill_vif(struct mr_table *mrt, u32 vifid, struct sk_buff *skb)
2984 {
2985 	struct net_device *vif_dev;
2986 	struct nlattr *vif_nest;
2987 	struct vif_device *vif;
2988 
2989 	vif = &mrt->vif_table[vifid];
2990 	vif_dev = vif_dev_read(vif);
2991 	/* if the VIF doesn't exist just continue */
2992 	if (!vif_dev)
2993 		return true;
2994 
2995 	vif_nest = nla_nest_start_noflag(skb, IPMRA_VIF);
2996 	if (!vif_nest)
2997 		return false;
2998 
2999 	if (nla_put_u32(skb, IPMRA_VIFA_IFINDEX, READ_ONCE(vif_dev->ifindex)) ||
3000 	    nla_put_u32(skb, IPMRA_VIFA_VIF_ID, vifid) ||
3001 	    nla_put_u16(skb, IPMRA_VIFA_FLAGS, vif->flags) ||
3002 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_IN, READ_ONCE(vif->bytes_in),
3003 			      IPMRA_VIFA_PAD) ||
3004 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_OUT, READ_ONCE(vif->bytes_out),
3005 			      IPMRA_VIFA_PAD) ||
3006 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_IN, READ_ONCE(vif->pkt_in),
3007 			      IPMRA_VIFA_PAD) ||
3008 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_OUT, READ_ONCE(vif->pkt_out),
3009 			      IPMRA_VIFA_PAD) ||
3010 	    nla_put_be32(skb, IPMRA_VIFA_LOCAL_ADDR, vif->local) ||
3011 	    nla_put_be32(skb, IPMRA_VIFA_REMOTE_ADDR, vif->remote)) {
3012 		nla_nest_cancel(skb, vif_nest);
3013 		return false;
3014 	}
3015 	nla_nest_end(skb, vif_nest);
3016 
3017 	return true;
3018 }
3019 
3020 static int ipmr_valid_dumplink(const struct nlmsghdr *nlh,
3021 			       struct netlink_ext_ack *extack)
3022 {
3023 	struct ifinfomsg *ifm;
3024 
3025 	ifm = nlmsg_payload(nlh, sizeof(*ifm));
3026 	if (!ifm) {
3027 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for ipmr link dump");
3028 		return -EINVAL;
3029 	}
3030 
3031 	if (nlmsg_attrlen(nlh, sizeof(*ifm))) {
3032 		NL_SET_ERR_MSG(extack, "Invalid data after header in ipmr link dump");
3033 		return -EINVAL;
3034 	}
3035 
3036 	if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags ||
3037 	    ifm->ifi_change || ifm->ifi_index) {
3038 		NL_SET_ERR_MSG(extack, "Invalid values in header for ipmr link dump request");
3039 		return -EINVAL;
3040 	}
3041 
3042 	return 0;
3043 }
3044 
3045 static int ipmr_rtm_dumplink(struct sk_buff *skb, struct netlink_callback *cb)
3046 {
3047 	struct net *net = sock_net(skb->sk);
3048 	struct nlmsghdr *nlh = NULL;
3049 	unsigned int t = 0, s_t;
3050 	unsigned int e = 0, s_e;
3051 	struct mr_table *mrt;
3052 
3053 	if (cb->strict_check) {
3054 		int err = ipmr_valid_dumplink(cb->nlh, cb->extack);
3055 
3056 		if (err < 0)
3057 			return err;
3058 	}
3059 
3060 	s_t = cb->args[0];
3061 	s_e = cb->args[1];
3062 
3063 	rcu_read_lock();
3064 
3065 	ipmr_for_each_table(mrt, net) {
3066 		struct nlattr *vifs, *af;
3067 		struct ifinfomsg *hdr;
3068 		u32 i;
3069 
3070 		if (t < s_t)
3071 			goto skip_table;
3072 		nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
3073 				cb->nlh->nlmsg_seq, RTM_NEWLINK,
3074 				sizeof(*hdr), NLM_F_MULTI);
3075 		if (!nlh)
3076 			break;
3077 
3078 		hdr = nlmsg_data(nlh);
3079 		memset(hdr, 0, sizeof(*hdr));
3080 		hdr->ifi_family = RTNL_FAMILY_IPMR;
3081 
3082 		af = nla_nest_start_noflag(skb, IFLA_AF_SPEC);
3083 		if (!af) {
3084 			nlmsg_cancel(skb, nlh);
3085 			goto out;
3086 		}
3087 
3088 		if (!ipmr_fill_table(mrt, skb)) {
3089 			nlmsg_cancel(skb, nlh);
3090 			goto out;
3091 		}
3092 
3093 		vifs = nla_nest_start_noflag(skb, IPMRA_TABLE_VIFS);
3094 		if (!vifs) {
3095 			nla_nest_end(skb, af);
3096 			nlmsg_end(skb, nlh);
3097 			goto out;
3098 		}
3099 		for (i = 0; i < READ_ONCE(mrt->maxvif); i++) {
3100 			if (e < s_e)
3101 				goto skip_entry;
3102 			if (!ipmr_fill_vif(mrt, i, skb)) {
3103 				nla_nest_end(skb, vifs);
3104 				nla_nest_end(skb, af);
3105 				nlmsg_end(skb, nlh);
3106 				goto out;
3107 			}
3108 skip_entry:
3109 			e++;
3110 		}
3111 		s_e = 0;
3112 		e = 0;
3113 		nla_nest_end(skb, vifs);
3114 		nla_nest_end(skb, af);
3115 		nlmsg_end(skb, nlh);
3116 skip_table:
3117 		t++;
3118 	}
3119 
3120 out:
3121 	rcu_read_unlock();
3122 
3123 	cb->args[1] = e;
3124 	cb->args[0] = t;
3125 
3126 	return skb->len;
3127 }
3128 
3129 #ifdef CONFIG_PROC_FS
3130 /* The /proc interfaces to multicast routing :
3131  * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
3132  */
3133 
3134 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
3135 	__acquires(RCU)
3136 {
3137 	struct mr_vif_iter *iter = seq->private;
3138 	struct net *net = seq_file_net(seq);
3139 	struct mr_table *mrt;
3140 
3141 	rcu_read_lock();
3142 	mrt = __ipmr_get_table(net, RT_TABLE_DEFAULT);
3143 	if (!mrt) {
3144 		rcu_read_unlock();
3145 		return ERR_PTR(-ENOENT);
3146 	}
3147 
3148 	iter->mrt = mrt;
3149 
3150 	return mr_vif_seq_start(seq, pos);
3151 }
3152 
3153 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
3154 	__releases(RCU)
3155 {
3156 	rcu_read_unlock();
3157 }
3158 
3159 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
3160 {
3161 	struct mr_vif_iter *iter = seq->private;
3162 	struct mr_table *mrt = iter->mrt;
3163 
3164 	if (v == SEQ_START_TOKEN) {
3165 		seq_puts(seq,
3166 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
3167 	} else {
3168 		const struct vif_device *vif = v;
3169 		const struct net_device *vif_dev;
3170 		const char *name;
3171 
3172 		vif_dev = vif_dev_read(vif);
3173 		name = vif_dev ? vif_dev->name : "none";
3174 		seq_printf(seq,
3175 			   "%2td %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
3176 			   vif - mrt->vif_table,
3177 			   name, vif->bytes_in, vif->pkt_in,
3178 			   vif->bytes_out, vif->pkt_out,
3179 			   vif->flags, vif->local, vif->remote);
3180 	}
3181 	return 0;
3182 }
3183 
3184 static const struct seq_operations ipmr_vif_seq_ops = {
3185 	.start = ipmr_vif_seq_start,
3186 	.next  = mr_vif_seq_next,
3187 	.stop  = ipmr_vif_seq_stop,
3188 	.show  = ipmr_vif_seq_show,
3189 };
3190 
3191 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
3192 {
3193 	struct net *net = seq_file_net(seq);
3194 	struct mr_table *mrt;
3195 
3196 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
3197 	if (!mrt)
3198 		return ERR_PTR(-ENOENT);
3199 
3200 	return mr_mfc_seq_start(seq, pos, mrt, &mfc_unres_lock);
3201 }
3202 
3203 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
3204 {
3205 	int n;
3206 
3207 	if (v == SEQ_START_TOKEN) {
3208 		seq_puts(seq,
3209 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
3210 	} else {
3211 		const struct mfc_cache *mfc = v;
3212 		const struct mr_mfc_iter *it = seq->private;
3213 		const struct mr_table *mrt = it->mrt;
3214 
3215 		seq_printf(seq, "%08X %08X %-3hd",
3216 			   (__force u32) mfc->mfc_mcastgrp,
3217 			   (__force u32) mfc->mfc_origin,
3218 			   mfc->_c.mfc_parent);
3219 
3220 		if (it->cache != &mrt->mfc_unres_queue) {
3221 			seq_printf(seq, " %8lu %8lu %8lu",
3222 				   atomic_long_read(&mfc->_c.mfc_un.res.pkt),
3223 				   atomic_long_read(&mfc->_c.mfc_un.res.bytes),
3224 				   atomic_long_read(&mfc->_c.mfc_un.res.wrong_if));
3225 			for (n = mfc->_c.mfc_un.res.minvif;
3226 			     n < mfc->_c.mfc_un.res.maxvif; n++) {
3227 				if (VIF_EXISTS(mrt, n) &&
3228 				    mfc->_c.mfc_un.res.ttls[n] < 255)
3229 					seq_printf(seq,
3230 					   " %2d:%-3d",
3231 					   n, mfc->_c.mfc_un.res.ttls[n]);
3232 			}
3233 		} else {
3234 			/* unresolved mfc_caches don't contain
3235 			 * pkt, bytes and wrong_if values
3236 			 */
3237 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
3238 		}
3239 		seq_putc(seq, '\n');
3240 	}
3241 	return 0;
3242 }
3243 
3244 static const struct seq_operations ipmr_mfc_seq_ops = {
3245 	.start = ipmr_mfc_seq_start,
3246 	.next  = mr_mfc_seq_next,
3247 	.stop  = mr_mfc_seq_stop,
3248 	.show  = ipmr_mfc_seq_show,
3249 };
3250 #endif
3251 
3252 #ifdef CONFIG_IP_PIMSM_V2
3253 static const struct net_protocol pim_protocol = {
3254 	.handler	=	pim_rcv,
3255 };
3256 #endif
3257 
3258 static unsigned int ipmr_seq_read(const struct net *net)
3259 {
3260 	return atomic_read(&net->ipv4.ipmr_seq) + ipmr_rules_seq_read(net);
3261 }
3262 
3263 static int ipmr_dump(struct net *net, struct notifier_block *nb,
3264 		     struct netlink_ext_ack *extack)
3265 {
3266 	return mr_dump(net, nb, RTNL_FAMILY_IPMR, ipmr_rules_dump,
3267 		       ipmr_mr_table_iter, extack);
3268 }
3269 
3270 static const struct fib_notifier_ops ipmr_notifier_ops_template = {
3271 	.family		= RTNL_FAMILY_IPMR,
3272 	.fib_seq_read	= ipmr_seq_read,
3273 	.fib_dump	= ipmr_dump,
3274 	.owner		= THIS_MODULE,
3275 };
3276 
3277 static int __net_init ipmr_notifier_init(struct net *net)
3278 {
3279 	struct fib_notifier_ops *ops;
3280 
3281 	atomic_set(&net->ipv4.ipmr_seq, 0);
3282 
3283 	ops = fib_notifier_ops_register(&ipmr_notifier_ops_template, net);
3284 	if (IS_ERR(ops))
3285 		return PTR_ERR(ops);
3286 	net->ipv4.ipmr_notifier_ops = ops;
3287 
3288 	return 0;
3289 }
3290 
3291 static void __net_exit ipmr_notifier_exit(struct net *net)
3292 {
3293 	fib_notifier_ops_unregister(net->ipv4.ipmr_notifier_ops);
3294 	net->ipv4.ipmr_notifier_ops = NULL;
3295 }
3296 
3297 /* Setup for IP multicast routing */
3298 static int __net_init ipmr_net_init(struct net *net)
3299 {
3300 	LIST_HEAD(dev_kill_list);
3301 	int err;
3302 
3303 	mutex_init(&net->ipv4.mfc_mutex);
3304 
3305 	err = ipmr_notifier_init(net);
3306 	if (err)
3307 		goto ipmr_notifier_fail;
3308 
3309 	err = ipmr_rules_init(net);
3310 	if (err < 0)
3311 		goto ipmr_rules_fail;
3312 
3313 #ifdef CONFIG_PROC_FS
3314 	err = -ENOMEM;
3315 	if (!proc_create_net("ip_mr_vif", 0, net->proc_net, &ipmr_vif_seq_ops,
3316 			sizeof(struct mr_vif_iter)))
3317 		goto proc_vif_fail;
3318 	if (!proc_create_net("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_seq_ops,
3319 			sizeof(struct mr_mfc_iter)))
3320 		goto proc_cache_fail;
3321 #endif
3322 	return 0;
3323 
3324 #ifdef CONFIG_PROC_FS
3325 proc_cache_fail:
3326 	remove_proc_entry("ip_mr_vif", net->proc_net);
3327 proc_vif_fail:
3328 	ipmr_rules_exit_rtnl(net, &dev_kill_list);
3329 	ipmr_rules_exit(net);
3330 #endif
3331 ipmr_rules_fail:
3332 	ipmr_notifier_exit(net);
3333 ipmr_notifier_fail:
3334 	return err;
3335 }
3336 
3337 static void __net_exit ipmr_net_exit(struct net *net)
3338 {
3339 #ifdef CONFIG_PROC_FS
3340 	remove_proc_entry("ip_mr_cache", net->proc_net);
3341 	remove_proc_entry("ip_mr_vif", net->proc_net);
3342 #endif
3343 	ipmr_rules_exit(net);
3344 	ipmr_notifier_exit(net);
3345 }
3346 
3347 static void __net_exit ipmr_net_exit_rtnl(struct net *net,
3348 					  struct list_head *dev_kill_list)
3349 {
3350 	ipmr_rules_exit_rtnl(net, dev_kill_list);
3351 }
3352 
3353 static struct pernet_operations ipmr_net_ops = {
3354 	.init = ipmr_net_init,
3355 	.exit = ipmr_net_exit,
3356 	.exit_rtnl = ipmr_net_exit_rtnl,
3357 };
3358 
3359 static const struct rtnl_msg_handler ipmr_rtnl_msg_handlers[] __initconst = {
3360 	{.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_GETLINK,
3361 	 .dumpit = ipmr_rtm_dumplink, .flags = RTNL_FLAG_DUMP_UNLOCKED},
3362 	{.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_NEWROUTE,
3363 	 .doit = ipmr_rtm_route, .flags = RTNL_FLAG_DOIT_UNLOCKED},
3364 	{.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_DELROUTE,
3365 	 .doit = ipmr_rtm_route, .flags = RTNL_FLAG_DOIT_UNLOCKED},
3366 	{.protocol = RTNL_FAMILY_IPMR, .msgtype = RTM_GETROUTE,
3367 	 .doit = ipmr_rtm_getroute, .dumpit = ipmr_rtm_dumproute,
3368 	 .flags = RTNL_FLAG_DOIT_UNLOCKED | RTNL_FLAG_DUMP_UNLOCKED},
3369 };
3370 
3371 int __init ip_mr_init(void)
3372 {
3373 	int err;
3374 
3375 	mrt_cachep = KMEM_CACHE(mfc_cache, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
3376 
3377 	err = register_pernet_subsys(&ipmr_net_ops);
3378 	if (err)
3379 		goto reg_pernet_fail;
3380 
3381 	err = register_netdevice_notifier(&ip_mr_notifier);
3382 	if (err)
3383 		goto reg_notif_fail;
3384 #ifdef CONFIG_IP_PIMSM_V2
3385 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
3386 		pr_err("%s: can't add PIM protocol\n", __func__);
3387 		err = -EAGAIN;
3388 		goto add_proto_fail;
3389 	}
3390 #endif
3391 	rtnl_register_many(ipmr_rtnl_msg_handlers);
3392 
3393 	return 0;
3394 
3395 #ifdef CONFIG_IP_PIMSM_V2
3396 add_proto_fail:
3397 	unregister_netdevice_notifier(&ip_mr_notifier);
3398 #endif
3399 reg_notif_fail:
3400 	unregister_pernet_subsys(&ipmr_net_ops);
3401 reg_pernet_fail:
3402 	kmem_cache_destroy(mrt_cachep);
3403 	return err;
3404 }
3405