xref: /openbmc/linux/net/ipv4/ipmr.c (revision 3ddc8b84)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	IP multicast routing support for mrouted 3.6/3.8
4  *
5  *		(c) 1995 Alan Cox, <alan@lxorguk.ukuu.org.uk>
6  *	  Linux Consultancy and Custom Driver Development
7  *
8  *	Fixes:
9  *	Michael Chastain	:	Incorrect size of copying.
10  *	Alan Cox		:	Added the cache manager code
11  *	Alan Cox		:	Fixed the clone/copy bug and device race.
12  *	Mike McLagan		:	Routing by source
13  *	Malcolm Beattie		:	Buffer handling fixes.
14  *	Alexey Kuznetsov	:	Double buffer free and other fixes.
15  *	SVR Anand		:	Fixed several multicast bugs and problems.
16  *	Alexey Kuznetsov	:	Status, optimisations and more.
17  *	Brad Parker		:	Better behaviour on mrouted upcall
18  *					overflow.
19  *      Carlos Picoto           :       PIMv1 Support
20  *	Pavlin Ivanov Radoslavov:	PIMv2 Registers must checksum only PIM header
21  *					Relax this requirement to work with older peers.
22  */
23 
24 #include <linux/uaccess.h>
25 #include <linux/types.h>
26 #include <linux/cache.h>
27 #include <linux/capability.h>
28 #include <linux/errno.h>
29 #include <linux/mm.h>
30 #include <linux/kernel.h>
31 #include <linux/fcntl.h>
32 #include <linux/stat.h>
33 #include <linux/socket.h>
34 #include <linux/in.h>
35 #include <linux/inet.h>
36 #include <linux/netdevice.h>
37 #include <linux/inetdevice.h>
38 #include <linux/igmp.h>
39 #include <linux/proc_fs.h>
40 #include <linux/seq_file.h>
41 #include <linux/mroute.h>
42 #include <linux/init.h>
43 #include <linux/if_ether.h>
44 #include <linux/slab.h>
45 #include <net/net_namespace.h>
46 #include <net/ip.h>
47 #include <net/protocol.h>
48 #include <linux/skbuff.h>
49 #include <net/route.h>
50 #include <net/icmp.h>
51 #include <net/udp.h>
52 #include <net/raw.h>
53 #include <linux/notifier.h>
54 #include <linux/if_arp.h>
55 #include <linux/netfilter_ipv4.h>
56 #include <linux/compat.h>
57 #include <linux/export.h>
58 #include <linux/rhashtable.h>
59 #include <net/ip_tunnels.h>
60 #include <net/checksum.h>
61 #include <net/netlink.h>
62 #include <net/fib_rules.h>
63 #include <linux/netconf.h>
64 #include <net/rtnh.h>
65 
66 #include <linux/nospec.h>
67 
68 struct ipmr_rule {
69 	struct fib_rule		common;
70 };
71 
72 struct ipmr_result {
73 	struct mr_table		*mrt;
74 };
75 
76 /* Big lock, protecting vif table, mrt cache and mroute socket state.
77  * Note that the changes are semaphored via rtnl_lock.
78  */
79 
80 static DEFINE_SPINLOCK(mrt_lock);
81 
82 static struct net_device *vif_dev_read(const struct vif_device *vif)
83 {
84 	return rcu_dereference(vif->dev);
85 }
86 
87 /* Multicast router control variables */
88 
89 /* Special spinlock for queue of unresolved entries */
90 static DEFINE_SPINLOCK(mfc_unres_lock);
91 
92 /* We return to original Alan's scheme. Hash table of resolved
93  * entries is changed only in process context and protected
94  * with weak lock mrt_lock. Queue of unresolved entries is protected
95  * with strong spinlock mfc_unres_lock.
96  *
97  * In this case data path is free of exclusive locks at all.
98  */
99 
100 static struct kmem_cache *mrt_cachep __ro_after_init;
101 
102 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
103 static void ipmr_free_table(struct mr_table *mrt);
104 
105 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
106 			  struct net_device *dev, struct sk_buff *skb,
107 			  struct mfc_cache *cache, int local);
108 static int ipmr_cache_report(const struct mr_table *mrt,
109 			     struct sk_buff *pkt, vifi_t vifi, int assert);
110 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
111 				 int cmd);
112 static void igmpmsg_netlink_event(const struct mr_table *mrt, struct sk_buff *pkt);
113 static void mroute_clean_tables(struct mr_table *mrt, int flags);
114 static void ipmr_expire_process(struct timer_list *t);
115 
116 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
117 #define ipmr_for_each_table(mrt, net)					\
118 	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list,	\
119 				lockdep_rtnl_is_held() ||		\
120 				list_empty(&net->ipv4.mr_tables))
121 
122 static struct mr_table *ipmr_mr_table_iter(struct net *net,
123 					   struct mr_table *mrt)
124 {
125 	struct mr_table *ret;
126 
127 	if (!mrt)
128 		ret = list_entry_rcu(net->ipv4.mr_tables.next,
129 				     struct mr_table, list);
130 	else
131 		ret = list_entry_rcu(mrt->list.next,
132 				     struct mr_table, list);
133 
134 	if (&ret->list == &net->ipv4.mr_tables)
135 		return NULL;
136 	return ret;
137 }
138 
139 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
140 {
141 	struct mr_table *mrt;
142 
143 	ipmr_for_each_table(mrt, net) {
144 		if (mrt->id == id)
145 			return mrt;
146 	}
147 	return NULL;
148 }
149 
150 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
151 			   struct mr_table **mrt)
152 {
153 	int err;
154 	struct ipmr_result res;
155 	struct fib_lookup_arg arg = {
156 		.result = &res,
157 		.flags = FIB_LOOKUP_NOREF,
158 	};
159 
160 	/* update flow if oif or iif point to device enslaved to l3mdev */
161 	l3mdev_update_flow(net, flowi4_to_flowi(flp4));
162 
163 	err = fib_rules_lookup(net->ipv4.mr_rules_ops,
164 			       flowi4_to_flowi(flp4), 0, &arg);
165 	if (err < 0)
166 		return err;
167 	*mrt = res.mrt;
168 	return 0;
169 }
170 
171 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
172 			    int flags, struct fib_lookup_arg *arg)
173 {
174 	struct ipmr_result *res = arg->result;
175 	struct mr_table *mrt;
176 
177 	switch (rule->action) {
178 	case FR_ACT_TO_TBL:
179 		break;
180 	case FR_ACT_UNREACHABLE:
181 		return -ENETUNREACH;
182 	case FR_ACT_PROHIBIT:
183 		return -EACCES;
184 	case FR_ACT_BLACKHOLE:
185 	default:
186 		return -EINVAL;
187 	}
188 
189 	arg->table = fib_rule_get_table(rule, arg);
190 
191 	mrt = ipmr_get_table(rule->fr_net, arg->table);
192 	if (!mrt)
193 		return -EAGAIN;
194 	res->mrt = mrt;
195 	return 0;
196 }
197 
198 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
199 {
200 	return 1;
201 }
202 
203 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
204 			       struct fib_rule_hdr *frh, struct nlattr **tb,
205 			       struct netlink_ext_ack *extack)
206 {
207 	return 0;
208 }
209 
210 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
211 			     struct nlattr **tb)
212 {
213 	return 1;
214 }
215 
216 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
217 			  struct fib_rule_hdr *frh)
218 {
219 	frh->dst_len = 0;
220 	frh->src_len = 0;
221 	frh->tos     = 0;
222 	return 0;
223 }
224 
225 static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
226 	.family		= RTNL_FAMILY_IPMR,
227 	.rule_size	= sizeof(struct ipmr_rule),
228 	.addr_size	= sizeof(u32),
229 	.action		= ipmr_rule_action,
230 	.match		= ipmr_rule_match,
231 	.configure	= ipmr_rule_configure,
232 	.compare	= ipmr_rule_compare,
233 	.fill		= ipmr_rule_fill,
234 	.nlgroup	= RTNLGRP_IPV4_RULE,
235 	.owner		= THIS_MODULE,
236 };
237 
238 static int __net_init ipmr_rules_init(struct net *net)
239 {
240 	struct fib_rules_ops *ops;
241 	struct mr_table *mrt;
242 	int err;
243 
244 	ops = fib_rules_register(&ipmr_rules_ops_template, net);
245 	if (IS_ERR(ops))
246 		return PTR_ERR(ops);
247 
248 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
249 
250 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
251 	if (IS_ERR(mrt)) {
252 		err = PTR_ERR(mrt);
253 		goto err1;
254 	}
255 
256 	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
257 	if (err < 0)
258 		goto err2;
259 
260 	net->ipv4.mr_rules_ops = ops;
261 	return 0;
262 
263 err2:
264 	rtnl_lock();
265 	ipmr_free_table(mrt);
266 	rtnl_unlock();
267 err1:
268 	fib_rules_unregister(ops);
269 	return err;
270 }
271 
272 static void __net_exit ipmr_rules_exit(struct net *net)
273 {
274 	struct mr_table *mrt, *next;
275 
276 	ASSERT_RTNL();
277 	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
278 		list_del(&mrt->list);
279 		ipmr_free_table(mrt);
280 	}
281 	fib_rules_unregister(net->ipv4.mr_rules_ops);
282 }
283 
284 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
285 			   struct netlink_ext_ack *extack)
286 {
287 	return fib_rules_dump(net, nb, RTNL_FAMILY_IPMR, extack);
288 }
289 
290 static unsigned int ipmr_rules_seq_read(struct net *net)
291 {
292 	return fib_rules_seq_read(net, RTNL_FAMILY_IPMR);
293 }
294 
295 bool ipmr_rule_default(const struct fib_rule *rule)
296 {
297 	return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
298 }
299 EXPORT_SYMBOL(ipmr_rule_default);
300 #else
301 #define ipmr_for_each_table(mrt, net) \
302 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
303 
304 static struct mr_table *ipmr_mr_table_iter(struct net *net,
305 					   struct mr_table *mrt)
306 {
307 	if (!mrt)
308 		return net->ipv4.mrt;
309 	return NULL;
310 }
311 
312 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
313 {
314 	return net->ipv4.mrt;
315 }
316 
317 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
318 			   struct mr_table **mrt)
319 {
320 	*mrt = net->ipv4.mrt;
321 	return 0;
322 }
323 
324 static int __net_init ipmr_rules_init(struct net *net)
325 {
326 	struct mr_table *mrt;
327 
328 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
329 	if (IS_ERR(mrt))
330 		return PTR_ERR(mrt);
331 	net->ipv4.mrt = mrt;
332 	return 0;
333 }
334 
335 static void __net_exit ipmr_rules_exit(struct net *net)
336 {
337 	ASSERT_RTNL();
338 	ipmr_free_table(net->ipv4.mrt);
339 	net->ipv4.mrt = NULL;
340 }
341 
342 static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
343 			   struct netlink_ext_ack *extack)
344 {
345 	return 0;
346 }
347 
348 static unsigned int ipmr_rules_seq_read(struct net *net)
349 {
350 	return 0;
351 }
352 
353 bool ipmr_rule_default(const struct fib_rule *rule)
354 {
355 	return true;
356 }
357 EXPORT_SYMBOL(ipmr_rule_default);
358 #endif
359 
360 static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
361 				const void *ptr)
362 {
363 	const struct mfc_cache_cmp_arg *cmparg = arg->key;
364 	const struct mfc_cache *c = ptr;
365 
366 	return cmparg->mfc_mcastgrp != c->mfc_mcastgrp ||
367 	       cmparg->mfc_origin != c->mfc_origin;
368 }
369 
370 static const struct rhashtable_params ipmr_rht_params = {
371 	.head_offset = offsetof(struct mr_mfc, mnode),
372 	.key_offset = offsetof(struct mfc_cache, cmparg),
373 	.key_len = sizeof(struct mfc_cache_cmp_arg),
374 	.nelem_hint = 3,
375 	.obj_cmpfn = ipmr_hash_cmp,
376 	.automatic_shrinking = true,
377 };
378 
379 static void ipmr_new_table_set(struct mr_table *mrt,
380 			       struct net *net)
381 {
382 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
383 	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
384 #endif
385 }
386 
387 static struct mfc_cache_cmp_arg ipmr_mr_table_ops_cmparg_any = {
388 	.mfc_mcastgrp = htonl(INADDR_ANY),
389 	.mfc_origin = htonl(INADDR_ANY),
390 };
391 
392 static struct mr_table_ops ipmr_mr_table_ops = {
393 	.rht_params = &ipmr_rht_params,
394 	.cmparg_any = &ipmr_mr_table_ops_cmparg_any,
395 };
396 
397 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
398 {
399 	struct mr_table *mrt;
400 
401 	/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
402 	if (id != RT_TABLE_DEFAULT && id >= 1000000000)
403 		return ERR_PTR(-EINVAL);
404 
405 	mrt = ipmr_get_table(net, id);
406 	if (mrt)
407 		return mrt;
408 
409 	return mr_table_alloc(net, id, &ipmr_mr_table_ops,
410 			      ipmr_expire_process, ipmr_new_table_set);
411 }
412 
413 static void ipmr_free_table(struct mr_table *mrt)
414 {
415 	timer_shutdown_sync(&mrt->ipmr_expire_timer);
416 	mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC |
417 				 MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC);
418 	rhltable_destroy(&mrt->mfc_hash);
419 	kfree(mrt);
420 }
421 
422 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
423 
424 /* Initialize ipmr pimreg/tunnel in_device */
425 static bool ipmr_init_vif_indev(const struct net_device *dev)
426 {
427 	struct in_device *in_dev;
428 
429 	ASSERT_RTNL();
430 
431 	in_dev = __in_dev_get_rtnl(dev);
432 	if (!in_dev)
433 		return false;
434 	ipv4_devconf_setall(in_dev);
435 	neigh_parms_data_state_setall(in_dev->arp_parms);
436 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
437 
438 	return true;
439 }
440 
441 static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
442 {
443 	struct net_device *tunnel_dev, *new_dev;
444 	struct ip_tunnel_parm p = { };
445 	int err;
446 
447 	tunnel_dev = __dev_get_by_name(net, "tunl0");
448 	if (!tunnel_dev)
449 		goto out;
450 
451 	p.iph.daddr = v->vifc_rmt_addr.s_addr;
452 	p.iph.saddr = v->vifc_lcl_addr.s_addr;
453 	p.iph.version = 4;
454 	p.iph.ihl = 5;
455 	p.iph.protocol = IPPROTO_IPIP;
456 	sprintf(p.name, "dvmrp%d", v->vifc_vifi);
457 
458 	if (!tunnel_dev->netdev_ops->ndo_tunnel_ctl)
459 		goto out;
460 	err = tunnel_dev->netdev_ops->ndo_tunnel_ctl(tunnel_dev, &p,
461 			SIOCADDTUNNEL);
462 	if (err)
463 		goto out;
464 
465 	new_dev = __dev_get_by_name(net, p.name);
466 	if (!new_dev)
467 		goto out;
468 
469 	new_dev->flags |= IFF_MULTICAST;
470 	if (!ipmr_init_vif_indev(new_dev))
471 		goto out_unregister;
472 	if (dev_open(new_dev, NULL))
473 		goto out_unregister;
474 	dev_hold(new_dev);
475 	err = dev_set_allmulti(new_dev, 1);
476 	if (err) {
477 		dev_close(new_dev);
478 		tunnel_dev->netdev_ops->ndo_tunnel_ctl(tunnel_dev, &p,
479 				SIOCDELTUNNEL);
480 		dev_put(new_dev);
481 		new_dev = ERR_PTR(err);
482 	}
483 	return new_dev;
484 
485 out_unregister:
486 	unregister_netdevice(new_dev);
487 out:
488 	return ERR_PTR(-ENOBUFS);
489 }
490 
491 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
492 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
493 {
494 	struct net *net = dev_net(dev);
495 	struct mr_table *mrt;
496 	struct flowi4 fl4 = {
497 		.flowi4_oif	= dev->ifindex,
498 		.flowi4_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
499 		.flowi4_mark	= skb->mark,
500 	};
501 	int err;
502 
503 	err = ipmr_fib_lookup(net, &fl4, &mrt);
504 	if (err < 0) {
505 		kfree_skb(skb);
506 		return err;
507 	}
508 
509 	DEV_STATS_ADD(dev, tx_bytes, skb->len);
510 	DEV_STATS_INC(dev, tx_packets);
511 	rcu_read_lock();
512 
513 	/* Pairs with WRITE_ONCE() in vif_add() and vif_delete() */
514 	ipmr_cache_report(mrt, skb, READ_ONCE(mrt->mroute_reg_vif_num),
515 			  IGMPMSG_WHOLEPKT);
516 
517 	rcu_read_unlock();
518 	kfree_skb(skb);
519 	return NETDEV_TX_OK;
520 }
521 
522 static int reg_vif_get_iflink(const struct net_device *dev)
523 {
524 	return 0;
525 }
526 
527 static const struct net_device_ops reg_vif_netdev_ops = {
528 	.ndo_start_xmit	= reg_vif_xmit,
529 	.ndo_get_iflink = reg_vif_get_iflink,
530 };
531 
532 static void reg_vif_setup(struct net_device *dev)
533 {
534 	dev->type		= ARPHRD_PIMREG;
535 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
536 	dev->flags		= IFF_NOARP;
537 	dev->netdev_ops		= &reg_vif_netdev_ops;
538 	dev->needs_free_netdev	= true;
539 	dev->features		|= NETIF_F_NETNS_LOCAL;
540 }
541 
542 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
543 {
544 	struct net_device *dev;
545 	char name[IFNAMSIZ];
546 
547 	if (mrt->id == RT_TABLE_DEFAULT)
548 		sprintf(name, "pimreg");
549 	else
550 		sprintf(name, "pimreg%u", mrt->id);
551 
552 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
553 
554 	if (!dev)
555 		return NULL;
556 
557 	dev_net_set(dev, net);
558 
559 	if (register_netdevice(dev)) {
560 		free_netdev(dev);
561 		return NULL;
562 	}
563 
564 	if (!ipmr_init_vif_indev(dev))
565 		goto failure;
566 	if (dev_open(dev, NULL))
567 		goto failure;
568 
569 	dev_hold(dev);
570 
571 	return dev;
572 
573 failure:
574 	unregister_netdevice(dev);
575 	return NULL;
576 }
577 
578 /* called with rcu_read_lock() */
579 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
580 		     unsigned int pimlen)
581 {
582 	struct net_device *reg_dev = NULL;
583 	struct iphdr *encap;
584 	int vif_num;
585 
586 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
587 	/* Check that:
588 	 * a. packet is really sent to a multicast group
589 	 * b. packet is not a NULL-REGISTER
590 	 * c. packet is not truncated
591 	 */
592 	if (!ipv4_is_multicast(encap->daddr) ||
593 	    encap->tot_len == 0 ||
594 	    ntohs(encap->tot_len) + pimlen > skb->len)
595 		return 1;
596 
597 	/* Pairs with WRITE_ONCE() in vif_add()/vid_delete() */
598 	vif_num = READ_ONCE(mrt->mroute_reg_vif_num);
599 	if (vif_num >= 0)
600 		reg_dev = vif_dev_read(&mrt->vif_table[vif_num]);
601 	if (!reg_dev)
602 		return 1;
603 
604 	skb->mac_header = skb->network_header;
605 	skb_pull(skb, (u8 *)encap - skb->data);
606 	skb_reset_network_header(skb);
607 	skb->protocol = htons(ETH_P_IP);
608 	skb->ip_summed = CHECKSUM_NONE;
609 
610 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
611 
612 	netif_rx(skb);
613 
614 	return NET_RX_SUCCESS;
615 }
616 #else
617 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
618 {
619 	return NULL;
620 }
621 #endif
622 
623 static int call_ipmr_vif_entry_notifiers(struct net *net,
624 					 enum fib_event_type event_type,
625 					 struct vif_device *vif,
626 					 struct net_device *vif_dev,
627 					 vifi_t vif_index, u32 tb_id)
628 {
629 	return mr_call_vif_notifiers(net, RTNL_FAMILY_IPMR, event_type,
630 				     vif, vif_dev, vif_index, tb_id,
631 				     &net->ipv4.ipmr_seq);
632 }
633 
634 static int call_ipmr_mfc_entry_notifiers(struct net *net,
635 					 enum fib_event_type event_type,
636 					 struct mfc_cache *mfc, u32 tb_id)
637 {
638 	return mr_call_mfc_notifiers(net, RTNL_FAMILY_IPMR, event_type,
639 				     &mfc->_c, tb_id, &net->ipv4.ipmr_seq);
640 }
641 
642 /**
643  *	vif_delete - Delete a VIF entry
644  *	@mrt: Table to delete from
645  *	@vifi: VIF identifier to delete
646  *	@notify: Set to 1, if the caller is a notifier_call
647  *	@head: if unregistering the VIF, place it on this queue
648  */
649 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
650 		      struct list_head *head)
651 {
652 	struct net *net = read_pnet(&mrt->net);
653 	struct vif_device *v;
654 	struct net_device *dev;
655 	struct in_device *in_dev;
656 
657 	if (vifi < 0 || vifi >= mrt->maxvif)
658 		return -EADDRNOTAVAIL;
659 
660 	v = &mrt->vif_table[vifi];
661 
662 	dev = rtnl_dereference(v->dev);
663 	if (!dev)
664 		return -EADDRNOTAVAIL;
665 
666 	spin_lock(&mrt_lock);
667 	call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_DEL, v, dev,
668 				      vifi, mrt->id);
669 	RCU_INIT_POINTER(v->dev, NULL);
670 
671 	if (vifi == mrt->mroute_reg_vif_num) {
672 		/* Pairs with READ_ONCE() in ipmr_cache_report() and reg_vif_xmit() */
673 		WRITE_ONCE(mrt->mroute_reg_vif_num, -1);
674 	}
675 	if (vifi + 1 == mrt->maxvif) {
676 		int tmp;
677 
678 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
679 			if (VIF_EXISTS(mrt, tmp))
680 				break;
681 		}
682 		WRITE_ONCE(mrt->maxvif, tmp + 1);
683 	}
684 
685 	spin_unlock(&mrt_lock);
686 
687 	dev_set_allmulti(dev, -1);
688 
689 	in_dev = __in_dev_get_rtnl(dev);
690 	if (in_dev) {
691 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
692 		inet_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
693 					    NETCONFA_MC_FORWARDING,
694 					    dev->ifindex, &in_dev->cnf);
695 		ip_rt_multicast_event(in_dev);
696 	}
697 
698 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
699 		unregister_netdevice_queue(dev, head);
700 
701 	netdev_put(dev, &v->dev_tracker);
702 	return 0;
703 }
704 
705 static void ipmr_cache_free_rcu(struct rcu_head *head)
706 {
707 	struct mr_mfc *c = container_of(head, struct mr_mfc, rcu);
708 
709 	kmem_cache_free(mrt_cachep, (struct mfc_cache *)c);
710 }
711 
712 static void ipmr_cache_free(struct mfc_cache *c)
713 {
714 	call_rcu(&c->_c.rcu, ipmr_cache_free_rcu);
715 }
716 
717 /* Destroy an unresolved cache entry, killing queued skbs
718  * and reporting error to netlink readers.
719  */
720 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
721 {
722 	struct net *net = read_pnet(&mrt->net);
723 	struct sk_buff *skb;
724 	struct nlmsgerr *e;
725 
726 	atomic_dec(&mrt->cache_resolve_queue_len);
727 
728 	while ((skb = skb_dequeue(&c->_c.mfc_un.unres.unresolved))) {
729 		if (ip_hdr(skb)->version == 0) {
730 			struct nlmsghdr *nlh = skb_pull(skb,
731 							sizeof(struct iphdr));
732 			nlh->nlmsg_type = NLMSG_ERROR;
733 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
734 			skb_trim(skb, nlh->nlmsg_len);
735 			e = nlmsg_data(nlh);
736 			e->error = -ETIMEDOUT;
737 			memset(&e->msg, 0, sizeof(e->msg));
738 
739 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
740 		} else {
741 			kfree_skb(skb);
742 		}
743 	}
744 
745 	ipmr_cache_free(c);
746 }
747 
748 /* Timer process for the unresolved queue. */
749 static void ipmr_expire_process(struct timer_list *t)
750 {
751 	struct mr_table *mrt = from_timer(mrt, t, ipmr_expire_timer);
752 	struct mr_mfc *c, *next;
753 	unsigned long expires;
754 	unsigned long now;
755 
756 	if (!spin_trylock(&mfc_unres_lock)) {
757 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
758 		return;
759 	}
760 
761 	if (list_empty(&mrt->mfc_unres_queue))
762 		goto out;
763 
764 	now = jiffies;
765 	expires = 10*HZ;
766 
767 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
768 		if (time_after(c->mfc_un.unres.expires, now)) {
769 			unsigned long interval = c->mfc_un.unres.expires - now;
770 			if (interval < expires)
771 				expires = interval;
772 			continue;
773 		}
774 
775 		list_del(&c->list);
776 		mroute_netlink_event(mrt, (struct mfc_cache *)c, RTM_DELROUTE);
777 		ipmr_destroy_unres(mrt, (struct mfc_cache *)c);
778 	}
779 
780 	if (!list_empty(&mrt->mfc_unres_queue))
781 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
782 
783 out:
784 	spin_unlock(&mfc_unres_lock);
785 }
786 
787 /* Fill oifs list. It is called under locked mrt_lock. */
788 static void ipmr_update_thresholds(struct mr_table *mrt, struct mr_mfc *cache,
789 				   unsigned char *ttls)
790 {
791 	int vifi;
792 
793 	cache->mfc_un.res.minvif = MAXVIFS;
794 	cache->mfc_un.res.maxvif = 0;
795 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
796 
797 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
798 		if (VIF_EXISTS(mrt, vifi) &&
799 		    ttls[vifi] && ttls[vifi] < 255) {
800 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
801 			if (cache->mfc_un.res.minvif > vifi)
802 				cache->mfc_un.res.minvif = vifi;
803 			if (cache->mfc_un.res.maxvif <= vifi)
804 				cache->mfc_un.res.maxvif = vifi + 1;
805 		}
806 	}
807 	cache->mfc_un.res.lastuse = jiffies;
808 }
809 
810 static int vif_add(struct net *net, struct mr_table *mrt,
811 		   struct vifctl *vifc, int mrtsock)
812 {
813 	struct netdev_phys_item_id ppid = { };
814 	int vifi = vifc->vifc_vifi;
815 	struct vif_device *v = &mrt->vif_table[vifi];
816 	struct net_device *dev;
817 	struct in_device *in_dev;
818 	int err;
819 
820 	/* Is vif busy ? */
821 	if (VIF_EXISTS(mrt, vifi))
822 		return -EADDRINUSE;
823 
824 	switch (vifc->vifc_flags) {
825 	case VIFF_REGISTER:
826 		if (!ipmr_pimsm_enabled())
827 			return -EINVAL;
828 		/* Special Purpose VIF in PIM
829 		 * All the packets will be sent to the daemon
830 		 */
831 		if (mrt->mroute_reg_vif_num >= 0)
832 			return -EADDRINUSE;
833 		dev = ipmr_reg_vif(net, mrt);
834 		if (!dev)
835 			return -ENOBUFS;
836 		err = dev_set_allmulti(dev, 1);
837 		if (err) {
838 			unregister_netdevice(dev);
839 			dev_put(dev);
840 			return err;
841 		}
842 		break;
843 	case VIFF_TUNNEL:
844 		dev = ipmr_new_tunnel(net, vifc);
845 		if (IS_ERR(dev))
846 			return PTR_ERR(dev);
847 		break;
848 	case VIFF_USE_IFINDEX:
849 	case 0:
850 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
851 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
852 			if (dev && !__in_dev_get_rtnl(dev)) {
853 				dev_put(dev);
854 				return -EADDRNOTAVAIL;
855 			}
856 		} else {
857 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
858 		}
859 		if (!dev)
860 			return -EADDRNOTAVAIL;
861 		err = dev_set_allmulti(dev, 1);
862 		if (err) {
863 			dev_put(dev);
864 			return err;
865 		}
866 		break;
867 	default:
868 		return -EINVAL;
869 	}
870 
871 	in_dev = __in_dev_get_rtnl(dev);
872 	if (!in_dev) {
873 		dev_put(dev);
874 		return -EADDRNOTAVAIL;
875 	}
876 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
877 	inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING,
878 				    dev->ifindex, &in_dev->cnf);
879 	ip_rt_multicast_event(in_dev);
880 
881 	/* Fill in the VIF structures */
882 	vif_device_init(v, dev, vifc->vifc_rate_limit,
883 			vifc->vifc_threshold,
884 			vifc->vifc_flags | (!mrtsock ? VIFF_STATIC : 0),
885 			(VIFF_TUNNEL | VIFF_REGISTER));
886 
887 	err = dev_get_port_parent_id(dev, &ppid, true);
888 	if (err == 0) {
889 		memcpy(v->dev_parent_id.id, ppid.id, ppid.id_len);
890 		v->dev_parent_id.id_len = ppid.id_len;
891 	} else {
892 		v->dev_parent_id.id_len = 0;
893 	}
894 
895 	v->local = vifc->vifc_lcl_addr.s_addr;
896 	v->remote = vifc->vifc_rmt_addr.s_addr;
897 
898 	/* And finish update writing critical data */
899 	spin_lock(&mrt_lock);
900 	rcu_assign_pointer(v->dev, dev);
901 	netdev_tracker_alloc(dev, &v->dev_tracker, GFP_ATOMIC);
902 	if (v->flags & VIFF_REGISTER) {
903 		/* Pairs with READ_ONCE() in ipmr_cache_report() and reg_vif_xmit() */
904 		WRITE_ONCE(mrt->mroute_reg_vif_num, vifi);
905 	}
906 	if (vifi+1 > mrt->maxvif)
907 		WRITE_ONCE(mrt->maxvif, vifi + 1);
908 	spin_unlock(&mrt_lock);
909 	call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD, v, dev,
910 				      vifi, mrt->id);
911 	return 0;
912 }
913 
914 /* called with rcu_read_lock() */
915 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
916 					 __be32 origin,
917 					 __be32 mcastgrp)
918 {
919 	struct mfc_cache_cmp_arg arg = {
920 			.mfc_mcastgrp = mcastgrp,
921 			.mfc_origin = origin
922 	};
923 
924 	return mr_mfc_find(mrt, &arg);
925 }
926 
927 /* Look for a (*,G) entry */
928 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
929 					     __be32 mcastgrp, int vifi)
930 {
931 	struct mfc_cache_cmp_arg arg = {
932 			.mfc_mcastgrp = mcastgrp,
933 			.mfc_origin = htonl(INADDR_ANY)
934 	};
935 
936 	if (mcastgrp == htonl(INADDR_ANY))
937 		return mr_mfc_find_any_parent(mrt, vifi);
938 	return mr_mfc_find_any(mrt, vifi, &arg);
939 }
940 
941 /* Look for a (S,G,iif) entry if parent != -1 */
942 static struct mfc_cache *ipmr_cache_find_parent(struct mr_table *mrt,
943 						__be32 origin, __be32 mcastgrp,
944 						int parent)
945 {
946 	struct mfc_cache_cmp_arg arg = {
947 			.mfc_mcastgrp = mcastgrp,
948 			.mfc_origin = origin,
949 	};
950 
951 	return mr_mfc_find_parent(mrt, &arg, parent);
952 }
953 
954 /* Allocate a multicast cache entry */
955 static struct mfc_cache *ipmr_cache_alloc(void)
956 {
957 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
958 
959 	if (c) {
960 		c->_c.mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
961 		c->_c.mfc_un.res.minvif = MAXVIFS;
962 		c->_c.free = ipmr_cache_free_rcu;
963 		refcount_set(&c->_c.mfc_un.res.refcount, 1);
964 	}
965 	return c;
966 }
967 
968 static struct mfc_cache *ipmr_cache_alloc_unres(void)
969 {
970 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
971 
972 	if (c) {
973 		skb_queue_head_init(&c->_c.mfc_un.unres.unresolved);
974 		c->_c.mfc_un.unres.expires = jiffies + 10 * HZ;
975 	}
976 	return c;
977 }
978 
979 /* A cache entry has gone into a resolved state from queued */
980 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
981 			       struct mfc_cache *uc, struct mfc_cache *c)
982 {
983 	struct sk_buff *skb;
984 	struct nlmsgerr *e;
985 
986 	/* Play the pending entries through our router */
987 	while ((skb = __skb_dequeue(&uc->_c.mfc_un.unres.unresolved))) {
988 		if (ip_hdr(skb)->version == 0) {
989 			struct nlmsghdr *nlh = skb_pull(skb,
990 							sizeof(struct iphdr));
991 
992 			if (mr_fill_mroute(mrt, skb, &c->_c,
993 					   nlmsg_data(nlh)) > 0) {
994 				nlh->nlmsg_len = skb_tail_pointer(skb) -
995 						 (u8 *)nlh;
996 			} else {
997 				nlh->nlmsg_type = NLMSG_ERROR;
998 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
999 				skb_trim(skb, nlh->nlmsg_len);
1000 				e = nlmsg_data(nlh);
1001 				e->error = -EMSGSIZE;
1002 				memset(&e->msg, 0, sizeof(e->msg));
1003 			}
1004 
1005 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
1006 		} else {
1007 			rcu_read_lock();
1008 			ip_mr_forward(net, mrt, skb->dev, skb, c, 0);
1009 			rcu_read_unlock();
1010 		}
1011 	}
1012 }
1013 
1014 /* Bounce a cache query up to mrouted and netlink.
1015  *
1016  * Called under rcu_read_lock().
1017  */
1018 static int ipmr_cache_report(const struct mr_table *mrt,
1019 			     struct sk_buff *pkt, vifi_t vifi, int assert)
1020 {
1021 	const int ihl = ip_hdrlen(pkt);
1022 	struct sock *mroute_sk;
1023 	struct igmphdr *igmp;
1024 	struct igmpmsg *msg;
1025 	struct sk_buff *skb;
1026 	int ret;
1027 
1028 	mroute_sk = rcu_dereference(mrt->mroute_sk);
1029 	if (!mroute_sk)
1030 		return -EINVAL;
1031 
1032 	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE)
1033 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
1034 	else
1035 		skb = alloc_skb(128, GFP_ATOMIC);
1036 
1037 	if (!skb)
1038 		return -ENOBUFS;
1039 
1040 	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE) {
1041 		/* Ugly, but we have no choice with this interface.
1042 		 * Duplicate old header, fix ihl, length etc.
1043 		 * And all this only to mangle msg->im_msgtype and
1044 		 * to set msg->im_mbz to "mbz" :-)
1045 		 */
1046 		skb_push(skb, sizeof(struct iphdr));
1047 		skb_reset_network_header(skb);
1048 		skb_reset_transport_header(skb);
1049 		msg = (struct igmpmsg *)skb_network_header(skb);
1050 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
1051 		msg->im_msgtype = assert;
1052 		msg->im_mbz = 0;
1053 		if (assert == IGMPMSG_WRVIFWHOLE) {
1054 			msg->im_vif = vifi;
1055 			msg->im_vif_hi = vifi >> 8;
1056 		} else {
1057 			/* Pairs with WRITE_ONCE() in vif_add() and vif_delete() */
1058 			int vif_num = READ_ONCE(mrt->mroute_reg_vif_num);
1059 
1060 			msg->im_vif = vif_num;
1061 			msg->im_vif_hi = vif_num >> 8;
1062 		}
1063 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
1064 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
1065 					     sizeof(struct iphdr));
1066 	} else {
1067 		/* Copy the IP header */
1068 		skb_set_network_header(skb, skb->len);
1069 		skb_put(skb, ihl);
1070 		skb_copy_to_linear_data(skb, pkt->data, ihl);
1071 		/* Flag to the kernel this is a route add */
1072 		ip_hdr(skb)->protocol = 0;
1073 		msg = (struct igmpmsg *)skb_network_header(skb);
1074 		msg->im_vif = vifi;
1075 		msg->im_vif_hi = vifi >> 8;
1076 		ipv4_pktinfo_prepare(mroute_sk, pkt);
1077 		memcpy(skb->cb, pkt->cb, sizeof(skb->cb));
1078 		/* Add our header */
1079 		igmp = skb_put(skb, sizeof(struct igmphdr));
1080 		igmp->type = assert;
1081 		msg->im_msgtype = assert;
1082 		igmp->code = 0;
1083 		ip_hdr(skb)->tot_len = htons(skb->len);	/* Fix the length */
1084 		skb->transport_header = skb->network_header;
1085 	}
1086 
1087 	igmpmsg_netlink_event(mrt, skb);
1088 
1089 	/* Deliver to mrouted */
1090 	ret = sock_queue_rcv_skb(mroute_sk, skb);
1091 
1092 	if (ret < 0) {
1093 		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1094 		kfree_skb(skb);
1095 	}
1096 
1097 	return ret;
1098 }
1099 
1100 /* Queue a packet for resolution. It gets locked cache entry! */
1101 /* Called under rcu_read_lock() */
1102 static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
1103 				 struct sk_buff *skb, struct net_device *dev)
1104 {
1105 	const struct iphdr *iph = ip_hdr(skb);
1106 	struct mfc_cache *c;
1107 	bool found = false;
1108 	int err;
1109 
1110 	spin_lock_bh(&mfc_unres_lock);
1111 	list_for_each_entry(c, &mrt->mfc_unres_queue, _c.list) {
1112 		if (c->mfc_mcastgrp == iph->daddr &&
1113 		    c->mfc_origin == iph->saddr) {
1114 			found = true;
1115 			break;
1116 		}
1117 	}
1118 
1119 	if (!found) {
1120 		/* Create a new entry if allowable */
1121 		c = ipmr_cache_alloc_unres();
1122 		if (!c) {
1123 			spin_unlock_bh(&mfc_unres_lock);
1124 
1125 			kfree_skb(skb);
1126 			return -ENOBUFS;
1127 		}
1128 
1129 		/* Fill in the new cache entry */
1130 		c->_c.mfc_parent = -1;
1131 		c->mfc_origin	= iph->saddr;
1132 		c->mfc_mcastgrp	= iph->daddr;
1133 
1134 		/* Reflect first query at mrouted. */
1135 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1136 
1137 		if (err < 0) {
1138 			/* If the report failed throw the cache entry
1139 			   out - Brad Parker
1140 			 */
1141 			spin_unlock_bh(&mfc_unres_lock);
1142 
1143 			ipmr_cache_free(c);
1144 			kfree_skb(skb);
1145 			return err;
1146 		}
1147 
1148 		atomic_inc(&mrt->cache_resolve_queue_len);
1149 		list_add(&c->_c.list, &mrt->mfc_unres_queue);
1150 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1151 
1152 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1153 			mod_timer(&mrt->ipmr_expire_timer,
1154 				  c->_c.mfc_un.unres.expires);
1155 	}
1156 
1157 	/* See if we can append the packet */
1158 	if (c->_c.mfc_un.unres.unresolved.qlen > 3) {
1159 		kfree_skb(skb);
1160 		err = -ENOBUFS;
1161 	} else {
1162 		if (dev) {
1163 			skb->dev = dev;
1164 			skb->skb_iif = dev->ifindex;
1165 		}
1166 		skb_queue_tail(&c->_c.mfc_un.unres.unresolved, skb);
1167 		err = 0;
1168 	}
1169 
1170 	spin_unlock_bh(&mfc_unres_lock);
1171 	return err;
1172 }
1173 
1174 /* MFC cache manipulation by user space mroute daemon */
1175 
1176 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1177 {
1178 	struct net *net = read_pnet(&mrt->net);
1179 	struct mfc_cache *c;
1180 
1181 	/* The entries are added/deleted only under RTNL */
1182 	rcu_read_lock();
1183 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1184 				   mfc->mfcc_mcastgrp.s_addr, parent);
1185 	rcu_read_unlock();
1186 	if (!c)
1187 		return -ENOENT;
1188 	rhltable_remove(&mrt->mfc_hash, &c->_c.mnode, ipmr_rht_params);
1189 	list_del_rcu(&c->_c.list);
1190 	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, c, mrt->id);
1191 	mroute_netlink_event(mrt, c, RTM_DELROUTE);
1192 	mr_cache_put(&c->_c);
1193 
1194 	return 0;
1195 }
1196 
1197 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1198 			struct mfcctl *mfc, int mrtsock, int parent)
1199 {
1200 	struct mfc_cache *uc, *c;
1201 	struct mr_mfc *_uc;
1202 	bool found;
1203 	int ret;
1204 
1205 	if (mfc->mfcc_parent >= MAXVIFS)
1206 		return -ENFILE;
1207 
1208 	/* The entries are added/deleted only under RTNL */
1209 	rcu_read_lock();
1210 	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1211 				   mfc->mfcc_mcastgrp.s_addr, parent);
1212 	rcu_read_unlock();
1213 	if (c) {
1214 		spin_lock(&mrt_lock);
1215 		c->_c.mfc_parent = mfc->mfcc_parent;
1216 		ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
1217 		if (!mrtsock)
1218 			c->_c.mfc_flags |= MFC_STATIC;
1219 		spin_unlock(&mrt_lock);
1220 		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, c,
1221 					      mrt->id);
1222 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1223 		return 0;
1224 	}
1225 
1226 	if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1227 	    !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1228 		return -EINVAL;
1229 
1230 	c = ipmr_cache_alloc();
1231 	if (!c)
1232 		return -ENOMEM;
1233 
1234 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1235 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1236 	c->_c.mfc_parent = mfc->mfcc_parent;
1237 	ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
1238 	if (!mrtsock)
1239 		c->_c.mfc_flags |= MFC_STATIC;
1240 
1241 	ret = rhltable_insert_key(&mrt->mfc_hash, &c->cmparg, &c->_c.mnode,
1242 				  ipmr_rht_params);
1243 	if (ret) {
1244 		pr_err("ipmr: rhtable insert error %d\n", ret);
1245 		ipmr_cache_free(c);
1246 		return ret;
1247 	}
1248 	list_add_tail_rcu(&c->_c.list, &mrt->mfc_cache_list);
1249 	/* Check to see if we resolved a queued list. If so we
1250 	 * need to send on the frames and tidy up.
1251 	 */
1252 	found = false;
1253 	spin_lock_bh(&mfc_unres_lock);
1254 	list_for_each_entry(_uc, &mrt->mfc_unres_queue, list) {
1255 		uc = (struct mfc_cache *)_uc;
1256 		if (uc->mfc_origin == c->mfc_origin &&
1257 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1258 			list_del(&_uc->list);
1259 			atomic_dec(&mrt->cache_resolve_queue_len);
1260 			found = true;
1261 			break;
1262 		}
1263 	}
1264 	if (list_empty(&mrt->mfc_unres_queue))
1265 		del_timer(&mrt->ipmr_expire_timer);
1266 	spin_unlock_bh(&mfc_unres_lock);
1267 
1268 	if (found) {
1269 		ipmr_cache_resolve(net, mrt, uc, c);
1270 		ipmr_cache_free(uc);
1271 	}
1272 	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, c, mrt->id);
1273 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1274 	return 0;
1275 }
1276 
1277 /* Close the multicast socket, and clear the vif tables etc */
1278 static void mroute_clean_tables(struct mr_table *mrt, int flags)
1279 {
1280 	struct net *net = read_pnet(&mrt->net);
1281 	struct mr_mfc *c, *tmp;
1282 	struct mfc_cache *cache;
1283 	LIST_HEAD(list);
1284 	int i;
1285 
1286 	/* Shut down all active vif entries */
1287 	if (flags & (MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC)) {
1288 		for (i = 0; i < mrt->maxvif; i++) {
1289 			if (((mrt->vif_table[i].flags & VIFF_STATIC) &&
1290 			     !(flags & MRT_FLUSH_VIFS_STATIC)) ||
1291 			    (!(mrt->vif_table[i].flags & VIFF_STATIC) && !(flags & MRT_FLUSH_VIFS)))
1292 				continue;
1293 			vif_delete(mrt, i, 0, &list);
1294 		}
1295 		unregister_netdevice_many(&list);
1296 	}
1297 
1298 	/* Wipe the cache */
1299 	if (flags & (MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC)) {
1300 		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
1301 			if (((c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC_STATIC)) ||
1302 			    (!(c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC)))
1303 				continue;
1304 			rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
1305 			list_del_rcu(&c->list);
1306 			cache = (struct mfc_cache *)c;
1307 			call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
1308 						      mrt->id);
1309 			mroute_netlink_event(mrt, cache, RTM_DELROUTE);
1310 			mr_cache_put(c);
1311 		}
1312 	}
1313 
1314 	if (flags & MRT_FLUSH_MFC) {
1315 		if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1316 			spin_lock_bh(&mfc_unres_lock);
1317 			list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
1318 				list_del(&c->list);
1319 				cache = (struct mfc_cache *)c;
1320 				mroute_netlink_event(mrt, cache, RTM_DELROUTE);
1321 				ipmr_destroy_unres(mrt, cache);
1322 			}
1323 			spin_unlock_bh(&mfc_unres_lock);
1324 		}
1325 	}
1326 }
1327 
1328 /* called from ip_ra_control(), before an RCU grace period,
1329  * we don't need to call synchronize_rcu() here
1330  */
1331 static void mrtsock_destruct(struct sock *sk)
1332 {
1333 	struct net *net = sock_net(sk);
1334 	struct mr_table *mrt;
1335 
1336 	rtnl_lock();
1337 	ipmr_for_each_table(mrt, net) {
1338 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1339 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1340 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1341 						    NETCONFA_MC_FORWARDING,
1342 						    NETCONFA_IFINDEX_ALL,
1343 						    net->ipv4.devconf_all);
1344 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1345 			mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_MFC);
1346 		}
1347 	}
1348 	rtnl_unlock();
1349 }
1350 
1351 /* Socket options and virtual interface manipulation. The whole
1352  * virtual interface system is a complete heap, but unfortunately
1353  * that's how BSD mrouted happens to think. Maybe one day with a proper
1354  * MOSPF/PIM router set up we can clean this up.
1355  */
1356 
1357 int ip_mroute_setsockopt(struct sock *sk, int optname, sockptr_t optval,
1358 			 unsigned int optlen)
1359 {
1360 	struct net *net = sock_net(sk);
1361 	int val, ret = 0, parent = 0;
1362 	struct mr_table *mrt;
1363 	struct vifctl vif;
1364 	struct mfcctl mfc;
1365 	bool do_wrvifwhole;
1366 	u32 uval;
1367 
1368 	/* There's one exception to the lock - MRT_DONE which needs to unlock */
1369 	rtnl_lock();
1370 	if (sk->sk_type != SOCK_RAW ||
1371 	    inet_sk(sk)->inet_num != IPPROTO_IGMP) {
1372 		ret = -EOPNOTSUPP;
1373 		goto out_unlock;
1374 	}
1375 
1376 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1377 	if (!mrt) {
1378 		ret = -ENOENT;
1379 		goto out_unlock;
1380 	}
1381 	if (optname != MRT_INIT) {
1382 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1383 		    !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
1384 			ret = -EACCES;
1385 			goto out_unlock;
1386 		}
1387 	}
1388 
1389 	switch (optname) {
1390 	case MRT_INIT:
1391 		if (optlen != sizeof(int)) {
1392 			ret = -EINVAL;
1393 			break;
1394 		}
1395 		if (rtnl_dereference(mrt->mroute_sk)) {
1396 			ret = -EADDRINUSE;
1397 			break;
1398 		}
1399 
1400 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1401 		if (ret == 0) {
1402 			rcu_assign_pointer(mrt->mroute_sk, sk);
1403 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1404 			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1405 						    NETCONFA_MC_FORWARDING,
1406 						    NETCONFA_IFINDEX_ALL,
1407 						    net->ipv4.devconf_all);
1408 		}
1409 		break;
1410 	case MRT_DONE:
1411 		if (sk != rcu_access_pointer(mrt->mroute_sk)) {
1412 			ret = -EACCES;
1413 		} else {
1414 			/* We need to unlock here because mrtsock_destruct takes
1415 			 * care of rtnl itself and we can't change that due to
1416 			 * the IP_ROUTER_ALERT setsockopt which runs without it.
1417 			 */
1418 			rtnl_unlock();
1419 			ret = ip_ra_control(sk, 0, NULL);
1420 			goto out;
1421 		}
1422 		break;
1423 	case MRT_ADD_VIF:
1424 	case MRT_DEL_VIF:
1425 		if (optlen != sizeof(vif)) {
1426 			ret = -EINVAL;
1427 			break;
1428 		}
1429 		if (copy_from_sockptr(&vif, optval, sizeof(vif))) {
1430 			ret = -EFAULT;
1431 			break;
1432 		}
1433 		if (vif.vifc_vifi >= MAXVIFS) {
1434 			ret = -ENFILE;
1435 			break;
1436 		}
1437 		if (optname == MRT_ADD_VIF) {
1438 			ret = vif_add(net, mrt, &vif,
1439 				      sk == rtnl_dereference(mrt->mroute_sk));
1440 		} else {
1441 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1442 		}
1443 		break;
1444 	/* Manipulate the forwarding caches. These live
1445 	 * in a sort of kernel/user symbiosis.
1446 	 */
1447 	case MRT_ADD_MFC:
1448 	case MRT_DEL_MFC:
1449 		parent = -1;
1450 		fallthrough;
1451 	case MRT_ADD_MFC_PROXY:
1452 	case MRT_DEL_MFC_PROXY:
1453 		if (optlen != sizeof(mfc)) {
1454 			ret = -EINVAL;
1455 			break;
1456 		}
1457 		if (copy_from_sockptr(&mfc, optval, sizeof(mfc))) {
1458 			ret = -EFAULT;
1459 			break;
1460 		}
1461 		if (parent == 0)
1462 			parent = mfc.mfcc_parent;
1463 		if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1464 			ret = ipmr_mfc_delete(mrt, &mfc, parent);
1465 		else
1466 			ret = ipmr_mfc_add(net, mrt, &mfc,
1467 					   sk == rtnl_dereference(mrt->mroute_sk),
1468 					   parent);
1469 		break;
1470 	case MRT_FLUSH:
1471 		if (optlen != sizeof(val)) {
1472 			ret = -EINVAL;
1473 			break;
1474 		}
1475 		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1476 			ret = -EFAULT;
1477 			break;
1478 		}
1479 		mroute_clean_tables(mrt, val);
1480 		break;
1481 	/* Control PIM assert. */
1482 	case MRT_ASSERT:
1483 		if (optlen != sizeof(val)) {
1484 			ret = -EINVAL;
1485 			break;
1486 		}
1487 		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1488 			ret = -EFAULT;
1489 			break;
1490 		}
1491 		mrt->mroute_do_assert = val;
1492 		break;
1493 	case MRT_PIM:
1494 		if (!ipmr_pimsm_enabled()) {
1495 			ret = -ENOPROTOOPT;
1496 			break;
1497 		}
1498 		if (optlen != sizeof(val)) {
1499 			ret = -EINVAL;
1500 			break;
1501 		}
1502 		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1503 			ret = -EFAULT;
1504 			break;
1505 		}
1506 
1507 		do_wrvifwhole = (val == IGMPMSG_WRVIFWHOLE);
1508 		val = !!val;
1509 		if (val != mrt->mroute_do_pim) {
1510 			mrt->mroute_do_pim = val;
1511 			mrt->mroute_do_assert = val;
1512 			mrt->mroute_do_wrvifwhole = do_wrvifwhole;
1513 		}
1514 		break;
1515 	case MRT_TABLE:
1516 		if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) {
1517 			ret = -ENOPROTOOPT;
1518 			break;
1519 		}
1520 		if (optlen != sizeof(uval)) {
1521 			ret = -EINVAL;
1522 			break;
1523 		}
1524 		if (copy_from_sockptr(&uval, optval, sizeof(uval))) {
1525 			ret = -EFAULT;
1526 			break;
1527 		}
1528 
1529 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1530 			ret = -EBUSY;
1531 		} else {
1532 			mrt = ipmr_new_table(net, uval);
1533 			if (IS_ERR(mrt))
1534 				ret = PTR_ERR(mrt);
1535 			else
1536 				raw_sk(sk)->ipmr_table = uval;
1537 		}
1538 		break;
1539 	/* Spurious command, or MRT_VERSION which you cannot set. */
1540 	default:
1541 		ret = -ENOPROTOOPT;
1542 	}
1543 out_unlock:
1544 	rtnl_unlock();
1545 out:
1546 	return ret;
1547 }
1548 
1549 /* Execute if this ioctl is a special mroute ioctl */
1550 int ipmr_sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1551 {
1552 	switch (cmd) {
1553 	/* These userspace buffers will be consumed by ipmr_ioctl() */
1554 	case SIOCGETVIFCNT: {
1555 		struct sioc_vif_req buffer;
1556 
1557 		return sock_ioctl_inout(sk, cmd, arg, &buffer,
1558 				      sizeof(buffer));
1559 		}
1560 	case SIOCGETSGCNT: {
1561 		struct sioc_sg_req buffer;
1562 
1563 		return sock_ioctl_inout(sk, cmd, arg, &buffer,
1564 				      sizeof(buffer));
1565 		}
1566 	}
1567 	/* return code > 0 means that the ioctl was not executed */
1568 	return 1;
1569 }
1570 
1571 /* Getsock opt support for the multicast routing system. */
1572 int ip_mroute_getsockopt(struct sock *sk, int optname, sockptr_t optval,
1573 			 sockptr_t optlen)
1574 {
1575 	int olr;
1576 	int val;
1577 	struct net *net = sock_net(sk);
1578 	struct mr_table *mrt;
1579 
1580 	if (sk->sk_type != SOCK_RAW ||
1581 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1582 		return -EOPNOTSUPP;
1583 
1584 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1585 	if (!mrt)
1586 		return -ENOENT;
1587 
1588 	switch (optname) {
1589 	case MRT_VERSION:
1590 		val = 0x0305;
1591 		break;
1592 	case MRT_PIM:
1593 		if (!ipmr_pimsm_enabled())
1594 			return -ENOPROTOOPT;
1595 		val = mrt->mroute_do_pim;
1596 		break;
1597 	case MRT_ASSERT:
1598 		val = mrt->mroute_do_assert;
1599 		break;
1600 	default:
1601 		return -ENOPROTOOPT;
1602 	}
1603 
1604 	if (copy_from_sockptr(&olr, optlen, sizeof(int)))
1605 		return -EFAULT;
1606 	olr = min_t(unsigned int, olr, sizeof(int));
1607 	if (olr < 0)
1608 		return -EINVAL;
1609 	if (copy_to_sockptr(optlen, &olr, sizeof(int)))
1610 		return -EFAULT;
1611 	if (copy_to_sockptr(optval, &val, olr))
1612 		return -EFAULT;
1613 	return 0;
1614 }
1615 
1616 /* The IP multicast ioctl support routines. */
1617 int ipmr_ioctl(struct sock *sk, int cmd, void *arg)
1618 {
1619 	struct vif_device *vif;
1620 	struct mfc_cache *c;
1621 	struct net *net = sock_net(sk);
1622 	struct sioc_vif_req *vr;
1623 	struct sioc_sg_req *sr;
1624 	struct mr_table *mrt;
1625 
1626 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1627 	if (!mrt)
1628 		return -ENOENT;
1629 
1630 	switch (cmd) {
1631 	case SIOCGETVIFCNT:
1632 		vr = (struct sioc_vif_req *)arg;
1633 		if (vr->vifi >= mrt->maxvif)
1634 			return -EINVAL;
1635 		vr->vifi = array_index_nospec(vr->vifi, mrt->maxvif);
1636 		rcu_read_lock();
1637 		vif = &mrt->vif_table[vr->vifi];
1638 		if (VIF_EXISTS(mrt, vr->vifi)) {
1639 			vr->icount = READ_ONCE(vif->pkt_in);
1640 			vr->ocount = READ_ONCE(vif->pkt_out);
1641 			vr->ibytes = READ_ONCE(vif->bytes_in);
1642 			vr->obytes = READ_ONCE(vif->bytes_out);
1643 			rcu_read_unlock();
1644 
1645 			return 0;
1646 		}
1647 		rcu_read_unlock();
1648 		return -EADDRNOTAVAIL;
1649 	case SIOCGETSGCNT:
1650 		sr = (struct sioc_sg_req *)arg;
1651 
1652 		rcu_read_lock();
1653 		c = ipmr_cache_find(mrt, sr->src.s_addr, sr->grp.s_addr);
1654 		if (c) {
1655 			sr->pktcnt = c->_c.mfc_un.res.pkt;
1656 			sr->bytecnt = c->_c.mfc_un.res.bytes;
1657 			sr->wrong_if = c->_c.mfc_un.res.wrong_if;
1658 			rcu_read_unlock();
1659 			return 0;
1660 		}
1661 		rcu_read_unlock();
1662 		return -EADDRNOTAVAIL;
1663 	default:
1664 		return -ENOIOCTLCMD;
1665 	}
1666 }
1667 
1668 #ifdef CONFIG_COMPAT
1669 struct compat_sioc_sg_req {
1670 	struct in_addr src;
1671 	struct in_addr grp;
1672 	compat_ulong_t pktcnt;
1673 	compat_ulong_t bytecnt;
1674 	compat_ulong_t wrong_if;
1675 };
1676 
1677 struct compat_sioc_vif_req {
1678 	vifi_t	vifi;		/* Which iface */
1679 	compat_ulong_t icount;
1680 	compat_ulong_t ocount;
1681 	compat_ulong_t ibytes;
1682 	compat_ulong_t obytes;
1683 };
1684 
1685 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1686 {
1687 	struct compat_sioc_sg_req sr;
1688 	struct compat_sioc_vif_req vr;
1689 	struct vif_device *vif;
1690 	struct mfc_cache *c;
1691 	struct net *net = sock_net(sk);
1692 	struct mr_table *mrt;
1693 
1694 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1695 	if (!mrt)
1696 		return -ENOENT;
1697 
1698 	switch (cmd) {
1699 	case SIOCGETVIFCNT:
1700 		if (copy_from_user(&vr, arg, sizeof(vr)))
1701 			return -EFAULT;
1702 		if (vr.vifi >= mrt->maxvif)
1703 			return -EINVAL;
1704 		vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif);
1705 		rcu_read_lock();
1706 		vif = &mrt->vif_table[vr.vifi];
1707 		if (VIF_EXISTS(mrt, vr.vifi)) {
1708 			vr.icount = READ_ONCE(vif->pkt_in);
1709 			vr.ocount = READ_ONCE(vif->pkt_out);
1710 			vr.ibytes = READ_ONCE(vif->bytes_in);
1711 			vr.obytes = READ_ONCE(vif->bytes_out);
1712 			rcu_read_unlock();
1713 
1714 			if (copy_to_user(arg, &vr, sizeof(vr)))
1715 				return -EFAULT;
1716 			return 0;
1717 		}
1718 		rcu_read_unlock();
1719 		return -EADDRNOTAVAIL;
1720 	case SIOCGETSGCNT:
1721 		if (copy_from_user(&sr, arg, sizeof(sr)))
1722 			return -EFAULT;
1723 
1724 		rcu_read_lock();
1725 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1726 		if (c) {
1727 			sr.pktcnt = c->_c.mfc_un.res.pkt;
1728 			sr.bytecnt = c->_c.mfc_un.res.bytes;
1729 			sr.wrong_if = c->_c.mfc_un.res.wrong_if;
1730 			rcu_read_unlock();
1731 
1732 			if (copy_to_user(arg, &sr, sizeof(sr)))
1733 				return -EFAULT;
1734 			return 0;
1735 		}
1736 		rcu_read_unlock();
1737 		return -EADDRNOTAVAIL;
1738 	default:
1739 		return -ENOIOCTLCMD;
1740 	}
1741 }
1742 #endif
1743 
1744 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1745 {
1746 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1747 	struct net *net = dev_net(dev);
1748 	struct mr_table *mrt;
1749 	struct vif_device *v;
1750 	int ct;
1751 
1752 	if (event != NETDEV_UNREGISTER)
1753 		return NOTIFY_DONE;
1754 
1755 	ipmr_for_each_table(mrt, net) {
1756 		v = &mrt->vif_table[0];
1757 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1758 			if (rcu_access_pointer(v->dev) == dev)
1759 				vif_delete(mrt, ct, 1, NULL);
1760 		}
1761 	}
1762 	return NOTIFY_DONE;
1763 }
1764 
1765 static struct notifier_block ip_mr_notifier = {
1766 	.notifier_call = ipmr_device_event,
1767 };
1768 
1769 /* Encapsulate a packet by attaching a valid IPIP header to it.
1770  * This avoids tunnel drivers and other mess and gives us the speed so
1771  * important for multicast video.
1772  */
1773 static void ip_encap(struct net *net, struct sk_buff *skb,
1774 		     __be32 saddr, __be32 daddr)
1775 {
1776 	struct iphdr *iph;
1777 	const struct iphdr *old_iph = ip_hdr(skb);
1778 
1779 	skb_push(skb, sizeof(struct iphdr));
1780 	skb->transport_header = skb->network_header;
1781 	skb_reset_network_header(skb);
1782 	iph = ip_hdr(skb);
1783 
1784 	iph->version	=	4;
1785 	iph->tos	=	old_iph->tos;
1786 	iph->ttl	=	old_iph->ttl;
1787 	iph->frag_off	=	0;
1788 	iph->daddr	=	daddr;
1789 	iph->saddr	=	saddr;
1790 	iph->protocol	=	IPPROTO_IPIP;
1791 	iph->ihl	=	5;
1792 	iph->tot_len	=	htons(skb->len);
1793 	ip_select_ident(net, skb, NULL);
1794 	ip_send_check(iph);
1795 
1796 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1797 	nf_reset_ct(skb);
1798 }
1799 
1800 static inline int ipmr_forward_finish(struct net *net, struct sock *sk,
1801 				      struct sk_buff *skb)
1802 {
1803 	struct ip_options *opt = &(IPCB(skb)->opt);
1804 
1805 	IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
1806 
1807 	if (unlikely(opt->optlen))
1808 		ip_forward_options(skb);
1809 
1810 	return dst_output(net, sk, skb);
1811 }
1812 
1813 #ifdef CONFIG_NET_SWITCHDEV
1814 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1815 				   int in_vifi, int out_vifi)
1816 {
1817 	struct vif_device *out_vif = &mrt->vif_table[out_vifi];
1818 	struct vif_device *in_vif = &mrt->vif_table[in_vifi];
1819 
1820 	if (!skb->offload_l3_fwd_mark)
1821 		return false;
1822 	if (!out_vif->dev_parent_id.id_len || !in_vif->dev_parent_id.id_len)
1823 		return false;
1824 	return netdev_phys_item_id_same(&out_vif->dev_parent_id,
1825 					&in_vif->dev_parent_id);
1826 }
1827 #else
1828 static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1829 				   int in_vifi, int out_vifi)
1830 {
1831 	return false;
1832 }
1833 #endif
1834 
1835 /* Processing handlers for ipmr_forward, under rcu_read_lock() */
1836 
1837 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1838 			    int in_vifi, struct sk_buff *skb, int vifi)
1839 {
1840 	const struct iphdr *iph = ip_hdr(skb);
1841 	struct vif_device *vif = &mrt->vif_table[vifi];
1842 	struct net_device *vif_dev;
1843 	struct net_device *dev;
1844 	struct rtable *rt;
1845 	struct flowi4 fl4;
1846 	int    encap = 0;
1847 
1848 	vif_dev = vif_dev_read(vif);
1849 	if (!vif_dev)
1850 		goto out_free;
1851 
1852 	if (vif->flags & VIFF_REGISTER) {
1853 		WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
1854 		WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len);
1855 		DEV_STATS_ADD(vif_dev, tx_bytes, skb->len);
1856 		DEV_STATS_INC(vif_dev, tx_packets);
1857 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1858 		goto out_free;
1859 	}
1860 
1861 	if (ipmr_forward_offloaded(skb, mrt, in_vifi, vifi))
1862 		goto out_free;
1863 
1864 	if (vif->flags & VIFF_TUNNEL) {
1865 		rt = ip_route_output_ports(net, &fl4, NULL,
1866 					   vif->remote, vif->local,
1867 					   0, 0,
1868 					   IPPROTO_IPIP,
1869 					   RT_TOS(iph->tos), vif->link);
1870 		if (IS_ERR(rt))
1871 			goto out_free;
1872 		encap = sizeof(struct iphdr);
1873 	} else {
1874 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1875 					   0, 0,
1876 					   IPPROTO_IPIP,
1877 					   RT_TOS(iph->tos), vif->link);
1878 		if (IS_ERR(rt))
1879 			goto out_free;
1880 	}
1881 
1882 	dev = rt->dst.dev;
1883 
1884 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1885 		/* Do not fragment multicasts. Alas, IPv4 does not
1886 		 * allow to send ICMP, so that packets will disappear
1887 		 * to blackhole.
1888 		 */
1889 		IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
1890 		ip_rt_put(rt);
1891 		goto out_free;
1892 	}
1893 
1894 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1895 
1896 	if (skb_cow(skb, encap)) {
1897 		ip_rt_put(rt);
1898 		goto out_free;
1899 	}
1900 
1901 	WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
1902 	WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len);
1903 
1904 	skb_dst_drop(skb);
1905 	skb_dst_set(skb, &rt->dst);
1906 	ip_decrease_ttl(ip_hdr(skb));
1907 
1908 	/* FIXME: forward and output firewalls used to be called here.
1909 	 * What do we do with netfilter? -- RR
1910 	 */
1911 	if (vif->flags & VIFF_TUNNEL) {
1912 		ip_encap(net, skb, vif->local, vif->remote);
1913 		/* FIXME: extra output firewall step used to be here. --RR */
1914 		DEV_STATS_INC(vif_dev, tx_packets);
1915 		DEV_STATS_ADD(vif_dev, tx_bytes, skb->len);
1916 	}
1917 
1918 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1919 
1920 	/* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1921 	 * not only before forwarding, but after forwarding on all output
1922 	 * interfaces. It is clear, if mrouter runs a multicasting
1923 	 * program, it should receive packets not depending to what interface
1924 	 * program is joined.
1925 	 * If we will not make it, the program will have to join on all
1926 	 * interfaces. On the other hand, multihoming host (or router, but
1927 	 * not mrouter) cannot join to more than one interface - it will
1928 	 * result in receiving multiple packets.
1929 	 */
1930 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
1931 		net, NULL, skb, skb->dev, dev,
1932 		ipmr_forward_finish);
1933 	return;
1934 
1935 out_free:
1936 	kfree_skb(skb);
1937 }
1938 
1939 /* Called with mrt_lock or rcu_read_lock() */
1940 static int ipmr_find_vif(const struct mr_table *mrt, struct net_device *dev)
1941 {
1942 	int ct;
1943 	/* Pairs with WRITE_ONCE() in vif_delete()/vif_add() */
1944 	for (ct = READ_ONCE(mrt->maxvif) - 1; ct >= 0; ct--) {
1945 		if (rcu_access_pointer(mrt->vif_table[ct].dev) == dev)
1946 			break;
1947 	}
1948 	return ct;
1949 }
1950 
1951 /* "local" means that we should preserve one skb (for local delivery) */
1952 /* Called uner rcu_read_lock() */
1953 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
1954 			  struct net_device *dev, struct sk_buff *skb,
1955 			  struct mfc_cache *c, int local)
1956 {
1957 	int true_vifi = ipmr_find_vif(mrt, dev);
1958 	int psend = -1;
1959 	int vif, ct;
1960 
1961 	vif = c->_c.mfc_parent;
1962 	c->_c.mfc_un.res.pkt++;
1963 	c->_c.mfc_un.res.bytes += skb->len;
1964 	c->_c.mfc_un.res.lastuse = jiffies;
1965 
1966 	if (c->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
1967 		struct mfc_cache *cache_proxy;
1968 
1969 		/* For an (*,G) entry, we only check that the incoming
1970 		 * interface is part of the static tree.
1971 		 */
1972 		cache_proxy = mr_mfc_find_any_parent(mrt, vif);
1973 		if (cache_proxy &&
1974 		    cache_proxy->_c.mfc_un.res.ttls[true_vifi] < 255)
1975 			goto forward;
1976 	}
1977 
1978 	/* Wrong interface: drop packet and (maybe) send PIM assert. */
1979 	if (rcu_access_pointer(mrt->vif_table[vif].dev) != dev) {
1980 		if (rt_is_output_route(skb_rtable(skb))) {
1981 			/* It is our own packet, looped back.
1982 			 * Very complicated situation...
1983 			 *
1984 			 * The best workaround until routing daemons will be
1985 			 * fixed is not to redistribute packet, if it was
1986 			 * send through wrong interface. It means, that
1987 			 * multicast applications WILL NOT work for
1988 			 * (S,G), which have default multicast route pointing
1989 			 * to wrong oif. In any case, it is not a good
1990 			 * idea to use multicasting applications on router.
1991 			 */
1992 			goto dont_forward;
1993 		}
1994 
1995 		c->_c.mfc_un.res.wrong_if++;
1996 
1997 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
1998 		    /* pimsm uses asserts, when switching from RPT to SPT,
1999 		     * so that we cannot check that packet arrived on an oif.
2000 		     * It is bad, but otherwise we would need to move pretty
2001 		     * large chunk of pimd to kernel. Ough... --ANK
2002 		     */
2003 		    (mrt->mroute_do_pim ||
2004 		     c->_c.mfc_un.res.ttls[true_vifi] < 255) &&
2005 		    time_after(jiffies,
2006 			       c->_c.mfc_un.res.last_assert +
2007 			       MFC_ASSERT_THRESH)) {
2008 			c->_c.mfc_un.res.last_assert = jiffies;
2009 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
2010 			if (mrt->mroute_do_wrvifwhole)
2011 				ipmr_cache_report(mrt, skb, true_vifi,
2012 						  IGMPMSG_WRVIFWHOLE);
2013 		}
2014 		goto dont_forward;
2015 	}
2016 
2017 forward:
2018 	WRITE_ONCE(mrt->vif_table[vif].pkt_in,
2019 		   mrt->vif_table[vif].pkt_in + 1);
2020 	WRITE_ONCE(mrt->vif_table[vif].bytes_in,
2021 		   mrt->vif_table[vif].bytes_in + skb->len);
2022 
2023 	/* Forward the frame */
2024 	if (c->mfc_origin == htonl(INADDR_ANY) &&
2025 	    c->mfc_mcastgrp == htonl(INADDR_ANY)) {
2026 		if (true_vifi >= 0 &&
2027 		    true_vifi != c->_c.mfc_parent &&
2028 		    ip_hdr(skb)->ttl >
2029 				c->_c.mfc_un.res.ttls[c->_c.mfc_parent]) {
2030 			/* It's an (*,*) entry and the packet is not coming from
2031 			 * the upstream: forward the packet to the upstream
2032 			 * only.
2033 			 */
2034 			psend = c->_c.mfc_parent;
2035 			goto last_forward;
2036 		}
2037 		goto dont_forward;
2038 	}
2039 	for (ct = c->_c.mfc_un.res.maxvif - 1;
2040 	     ct >= c->_c.mfc_un.res.minvif; ct--) {
2041 		/* For (*,G) entry, don't forward to the incoming interface */
2042 		if ((c->mfc_origin != htonl(INADDR_ANY) ||
2043 		     ct != true_vifi) &&
2044 		    ip_hdr(skb)->ttl > c->_c.mfc_un.res.ttls[ct]) {
2045 			if (psend != -1) {
2046 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2047 
2048 				if (skb2)
2049 					ipmr_queue_xmit(net, mrt, true_vifi,
2050 							skb2, psend);
2051 			}
2052 			psend = ct;
2053 		}
2054 	}
2055 last_forward:
2056 	if (psend != -1) {
2057 		if (local) {
2058 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2059 
2060 			if (skb2)
2061 				ipmr_queue_xmit(net, mrt, true_vifi, skb2,
2062 						psend);
2063 		} else {
2064 			ipmr_queue_xmit(net, mrt, true_vifi, skb, psend);
2065 			return;
2066 		}
2067 	}
2068 
2069 dont_forward:
2070 	if (!local)
2071 		kfree_skb(skb);
2072 }
2073 
2074 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
2075 {
2076 	struct rtable *rt = skb_rtable(skb);
2077 	struct iphdr *iph = ip_hdr(skb);
2078 	struct flowi4 fl4 = {
2079 		.daddr = iph->daddr,
2080 		.saddr = iph->saddr,
2081 		.flowi4_tos = RT_TOS(iph->tos),
2082 		.flowi4_oif = (rt_is_output_route(rt) ?
2083 			       skb->dev->ifindex : 0),
2084 		.flowi4_iif = (rt_is_output_route(rt) ?
2085 			       LOOPBACK_IFINDEX :
2086 			       skb->dev->ifindex),
2087 		.flowi4_mark = skb->mark,
2088 	};
2089 	struct mr_table *mrt;
2090 	int err;
2091 
2092 	err = ipmr_fib_lookup(net, &fl4, &mrt);
2093 	if (err)
2094 		return ERR_PTR(err);
2095 	return mrt;
2096 }
2097 
2098 /* Multicast packets for forwarding arrive here
2099  * Called with rcu_read_lock();
2100  */
2101 int ip_mr_input(struct sk_buff *skb)
2102 {
2103 	struct mfc_cache *cache;
2104 	struct net *net = dev_net(skb->dev);
2105 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
2106 	struct mr_table *mrt;
2107 	struct net_device *dev;
2108 
2109 	/* skb->dev passed in is the loX master dev for vrfs.
2110 	 * As there are no vifs associated with loopback devices,
2111 	 * get the proper interface that does have a vif associated with it.
2112 	 */
2113 	dev = skb->dev;
2114 	if (netif_is_l3_master(skb->dev)) {
2115 		dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
2116 		if (!dev) {
2117 			kfree_skb(skb);
2118 			return -ENODEV;
2119 		}
2120 	}
2121 
2122 	/* Packet is looped back after forward, it should not be
2123 	 * forwarded second time, but still can be delivered locally.
2124 	 */
2125 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
2126 		goto dont_forward;
2127 
2128 	mrt = ipmr_rt_fib_lookup(net, skb);
2129 	if (IS_ERR(mrt)) {
2130 		kfree_skb(skb);
2131 		return PTR_ERR(mrt);
2132 	}
2133 	if (!local) {
2134 		if (IPCB(skb)->opt.router_alert) {
2135 			if (ip_call_ra_chain(skb))
2136 				return 0;
2137 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
2138 			/* IGMPv1 (and broken IGMPv2 implementations sort of
2139 			 * Cisco IOS <= 11.2(8)) do not put router alert
2140 			 * option to IGMP packets destined to routable
2141 			 * groups. It is very bad, because it means
2142 			 * that we can forward NO IGMP messages.
2143 			 */
2144 			struct sock *mroute_sk;
2145 
2146 			mroute_sk = rcu_dereference(mrt->mroute_sk);
2147 			if (mroute_sk) {
2148 				nf_reset_ct(skb);
2149 				raw_rcv(mroute_sk, skb);
2150 				return 0;
2151 			}
2152 		}
2153 	}
2154 
2155 	/* already under rcu_read_lock() */
2156 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
2157 	if (!cache) {
2158 		int vif = ipmr_find_vif(mrt, dev);
2159 
2160 		if (vif >= 0)
2161 			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
2162 						    vif);
2163 	}
2164 
2165 	/* No usable cache entry */
2166 	if (!cache) {
2167 		int vif;
2168 
2169 		if (local) {
2170 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2171 			ip_local_deliver(skb);
2172 			if (!skb2)
2173 				return -ENOBUFS;
2174 			skb = skb2;
2175 		}
2176 
2177 		vif = ipmr_find_vif(mrt, dev);
2178 		if (vif >= 0)
2179 			return ipmr_cache_unresolved(mrt, vif, skb, dev);
2180 		kfree_skb(skb);
2181 		return -ENODEV;
2182 	}
2183 
2184 	ip_mr_forward(net, mrt, dev, skb, cache, local);
2185 
2186 	if (local)
2187 		return ip_local_deliver(skb);
2188 
2189 	return 0;
2190 
2191 dont_forward:
2192 	if (local)
2193 		return ip_local_deliver(skb);
2194 	kfree_skb(skb);
2195 	return 0;
2196 }
2197 
2198 #ifdef CONFIG_IP_PIMSM_V1
2199 /* Handle IGMP messages of PIMv1 */
2200 int pim_rcv_v1(struct sk_buff *skb)
2201 {
2202 	struct igmphdr *pim;
2203 	struct net *net = dev_net(skb->dev);
2204 	struct mr_table *mrt;
2205 
2206 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2207 		goto drop;
2208 
2209 	pim = igmp_hdr(skb);
2210 
2211 	mrt = ipmr_rt_fib_lookup(net, skb);
2212 	if (IS_ERR(mrt))
2213 		goto drop;
2214 	if (!mrt->mroute_do_pim ||
2215 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2216 		goto drop;
2217 
2218 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2219 drop:
2220 		kfree_skb(skb);
2221 	}
2222 	return 0;
2223 }
2224 #endif
2225 
2226 #ifdef CONFIG_IP_PIMSM_V2
2227 static int pim_rcv(struct sk_buff *skb)
2228 {
2229 	struct pimreghdr *pim;
2230 	struct net *net = dev_net(skb->dev);
2231 	struct mr_table *mrt;
2232 
2233 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2234 		goto drop;
2235 
2236 	pim = (struct pimreghdr *)skb_transport_header(skb);
2237 	if (pim->type != ((PIM_VERSION << 4) | (PIM_TYPE_REGISTER)) ||
2238 	    (pim->flags & PIM_NULL_REGISTER) ||
2239 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2240 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2241 		goto drop;
2242 
2243 	mrt = ipmr_rt_fib_lookup(net, skb);
2244 	if (IS_ERR(mrt))
2245 		goto drop;
2246 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2247 drop:
2248 		kfree_skb(skb);
2249 	}
2250 	return 0;
2251 }
2252 #endif
2253 
2254 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2255 		   __be32 saddr, __be32 daddr,
2256 		   struct rtmsg *rtm, u32 portid)
2257 {
2258 	struct mfc_cache *cache;
2259 	struct mr_table *mrt;
2260 	int err;
2261 
2262 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2263 	if (!mrt)
2264 		return -ENOENT;
2265 
2266 	rcu_read_lock();
2267 	cache = ipmr_cache_find(mrt, saddr, daddr);
2268 	if (!cache && skb->dev) {
2269 		int vif = ipmr_find_vif(mrt, skb->dev);
2270 
2271 		if (vif >= 0)
2272 			cache = ipmr_cache_find_any(mrt, daddr, vif);
2273 	}
2274 	if (!cache) {
2275 		struct sk_buff *skb2;
2276 		struct iphdr *iph;
2277 		struct net_device *dev;
2278 		int vif = -1;
2279 
2280 		dev = skb->dev;
2281 		if (dev)
2282 			vif = ipmr_find_vif(mrt, dev);
2283 		if (vif < 0) {
2284 			rcu_read_unlock();
2285 			return -ENODEV;
2286 		}
2287 
2288 		skb2 = skb_realloc_headroom(skb, sizeof(struct iphdr));
2289 		if (!skb2) {
2290 			rcu_read_unlock();
2291 			return -ENOMEM;
2292 		}
2293 
2294 		NETLINK_CB(skb2).portid = portid;
2295 		skb_push(skb2, sizeof(struct iphdr));
2296 		skb_reset_network_header(skb2);
2297 		iph = ip_hdr(skb2);
2298 		iph->ihl = sizeof(struct iphdr) >> 2;
2299 		iph->saddr = saddr;
2300 		iph->daddr = daddr;
2301 		iph->version = 0;
2302 		err = ipmr_cache_unresolved(mrt, vif, skb2, dev);
2303 		rcu_read_unlock();
2304 		return err;
2305 	}
2306 
2307 	err = mr_fill_mroute(mrt, skb, &cache->_c, rtm);
2308 	rcu_read_unlock();
2309 	return err;
2310 }
2311 
2312 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2313 			    u32 portid, u32 seq, struct mfc_cache *c, int cmd,
2314 			    int flags)
2315 {
2316 	struct nlmsghdr *nlh;
2317 	struct rtmsg *rtm;
2318 	int err;
2319 
2320 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2321 	if (!nlh)
2322 		return -EMSGSIZE;
2323 
2324 	rtm = nlmsg_data(nlh);
2325 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2326 	rtm->rtm_dst_len  = 32;
2327 	rtm->rtm_src_len  = 32;
2328 	rtm->rtm_tos      = 0;
2329 	rtm->rtm_table    = mrt->id;
2330 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2331 		goto nla_put_failure;
2332 	rtm->rtm_type     = RTN_MULTICAST;
2333 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2334 	if (c->_c.mfc_flags & MFC_STATIC)
2335 		rtm->rtm_protocol = RTPROT_STATIC;
2336 	else
2337 		rtm->rtm_protocol = RTPROT_MROUTED;
2338 	rtm->rtm_flags    = 0;
2339 
2340 	if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
2341 	    nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
2342 		goto nla_put_failure;
2343 	err = mr_fill_mroute(mrt, skb, &c->_c, rtm);
2344 	/* do not break the dump if cache is unresolved */
2345 	if (err < 0 && err != -ENOENT)
2346 		goto nla_put_failure;
2347 
2348 	nlmsg_end(skb, nlh);
2349 	return 0;
2350 
2351 nla_put_failure:
2352 	nlmsg_cancel(skb, nlh);
2353 	return -EMSGSIZE;
2354 }
2355 
2356 static int _ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2357 			     u32 portid, u32 seq, struct mr_mfc *c, int cmd,
2358 			     int flags)
2359 {
2360 	return ipmr_fill_mroute(mrt, skb, portid, seq, (struct mfc_cache *)c,
2361 				cmd, flags);
2362 }
2363 
2364 static size_t mroute_msgsize(bool unresolved, int maxvif)
2365 {
2366 	size_t len =
2367 		NLMSG_ALIGN(sizeof(struct rtmsg))
2368 		+ nla_total_size(4)	/* RTA_TABLE */
2369 		+ nla_total_size(4)	/* RTA_SRC */
2370 		+ nla_total_size(4)	/* RTA_DST */
2371 		;
2372 
2373 	if (!unresolved)
2374 		len = len
2375 		      + nla_total_size(4)	/* RTA_IIF */
2376 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2377 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2378 						/* RTA_MFC_STATS */
2379 		      + nla_total_size_64bit(sizeof(struct rta_mfc_stats))
2380 		;
2381 
2382 	return len;
2383 }
2384 
2385 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2386 				 int cmd)
2387 {
2388 	struct net *net = read_pnet(&mrt->net);
2389 	struct sk_buff *skb;
2390 	int err = -ENOBUFS;
2391 
2392 	skb = nlmsg_new(mroute_msgsize(mfc->_c.mfc_parent >= MAXVIFS,
2393 				       mrt->maxvif),
2394 			GFP_ATOMIC);
2395 	if (!skb)
2396 		goto errout;
2397 
2398 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2399 	if (err < 0)
2400 		goto errout;
2401 
2402 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2403 	return;
2404 
2405 errout:
2406 	kfree_skb(skb);
2407 	if (err < 0)
2408 		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2409 }
2410 
2411 static size_t igmpmsg_netlink_msgsize(size_t payloadlen)
2412 {
2413 	size_t len =
2414 		NLMSG_ALIGN(sizeof(struct rtgenmsg))
2415 		+ nla_total_size(1)	/* IPMRA_CREPORT_MSGTYPE */
2416 		+ nla_total_size(4)	/* IPMRA_CREPORT_VIF_ID */
2417 		+ nla_total_size(4)	/* IPMRA_CREPORT_SRC_ADDR */
2418 		+ nla_total_size(4)	/* IPMRA_CREPORT_DST_ADDR */
2419 		+ nla_total_size(4)	/* IPMRA_CREPORT_TABLE */
2420 					/* IPMRA_CREPORT_PKT */
2421 		+ nla_total_size(payloadlen)
2422 		;
2423 
2424 	return len;
2425 }
2426 
2427 static void igmpmsg_netlink_event(const struct mr_table *mrt, struct sk_buff *pkt)
2428 {
2429 	struct net *net = read_pnet(&mrt->net);
2430 	struct nlmsghdr *nlh;
2431 	struct rtgenmsg *rtgenm;
2432 	struct igmpmsg *msg;
2433 	struct sk_buff *skb;
2434 	struct nlattr *nla;
2435 	int payloadlen;
2436 
2437 	payloadlen = pkt->len - sizeof(struct igmpmsg);
2438 	msg = (struct igmpmsg *)skb_network_header(pkt);
2439 
2440 	skb = nlmsg_new(igmpmsg_netlink_msgsize(payloadlen), GFP_ATOMIC);
2441 	if (!skb)
2442 		goto errout;
2443 
2444 	nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT,
2445 			sizeof(struct rtgenmsg), 0);
2446 	if (!nlh)
2447 		goto errout;
2448 	rtgenm = nlmsg_data(nlh);
2449 	rtgenm->rtgen_family = RTNL_FAMILY_IPMR;
2450 	if (nla_put_u8(skb, IPMRA_CREPORT_MSGTYPE, msg->im_msgtype) ||
2451 	    nla_put_u32(skb, IPMRA_CREPORT_VIF_ID, msg->im_vif | (msg->im_vif_hi << 8)) ||
2452 	    nla_put_in_addr(skb, IPMRA_CREPORT_SRC_ADDR,
2453 			    msg->im_src.s_addr) ||
2454 	    nla_put_in_addr(skb, IPMRA_CREPORT_DST_ADDR,
2455 			    msg->im_dst.s_addr) ||
2456 	    nla_put_u32(skb, IPMRA_CREPORT_TABLE, mrt->id))
2457 		goto nla_put_failure;
2458 
2459 	nla = nla_reserve(skb, IPMRA_CREPORT_PKT, payloadlen);
2460 	if (!nla || skb_copy_bits(pkt, sizeof(struct igmpmsg),
2461 				  nla_data(nla), payloadlen))
2462 		goto nla_put_failure;
2463 
2464 	nlmsg_end(skb, nlh);
2465 
2466 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE_R, NULL, GFP_ATOMIC);
2467 	return;
2468 
2469 nla_put_failure:
2470 	nlmsg_cancel(skb, nlh);
2471 errout:
2472 	kfree_skb(skb);
2473 	rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE_R, -ENOBUFS);
2474 }
2475 
2476 static int ipmr_rtm_valid_getroute_req(struct sk_buff *skb,
2477 				       const struct nlmsghdr *nlh,
2478 				       struct nlattr **tb,
2479 				       struct netlink_ext_ack *extack)
2480 {
2481 	struct rtmsg *rtm;
2482 	int i, err;
2483 
2484 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2485 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for multicast route get request");
2486 		return -EINVAL;
2487 	}
2488 
2489 	if (!netlink_strict_get_check(skb))
2490 		return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
2491 					      rtm_ipv4_policy, extack);
2492 
2493 	rtm = nlmsg_data(nlh);
2494 	if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
2495 	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
2496 	    rtm->rtm_tos || rtm->rtm_table || rtm->rtm_protocol ||
2497 	    rtm->rtm_scope || rtm->rtm_type || rtm->rtm_flags) {
2498 		NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for multicast route get request");
2499 		return -EINVAL;
2500 	}
2501 
2502 	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2503 					    rtm_ipv4_policy, extack);
2504 	if (err)
2505 		return err;
2506 
2507 	if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
2508 	    (tb[RTA_DST] && !rtm->rtm_dst_len)) {
2509 		NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
2510 		return -EINVAL;
2511 	}
2512 
2513 	for (i = 0; i <= RTA_MAX; i++) {
2514 		if (!tb[i])
2515 			continue;
2516 
2517 		switch (i) {
2518 		case RTA_SRC:
2519 		case RTA_DST:
2520 		case RTA_TABLE:
2521 			break;
2522 		default:
2523 			NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in multicast route get request");
2524 			return -EINVAL;
2525 		}
2526 	}
2527 
2528 	return 0;
2529 }
2530 
2531 static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2532 			     struct netlink_ext_ack *extack)
2533 {
2534 	struct net *net = sock_net(in_skb->sk);
2535 	struct nlattr *tb[RTA_MAX + 1];
2536 	struct sk_buff *skb = NULL;
2537 	struct mfc_cache *cache;
2538 	struct mr_table *mrt;
2539 	__be32 src, grp;
2540 	u32 tableid;
2541 	int err;
2542 
2543 	err = ipmr_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
2544 	if (err < 0)
2545 		goto errout;
2546 
2547 	src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2548 	grp = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2549 	tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0;
2550 
2551 	mrt = ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT);
2552 	if (!mrt) {
2553 		err = -ENOENT;
2554 		goto errout_free;
2555 	}
2556 
2557 	/* entries are added/deleted only under RTNL */
2558 	rcu_read_lock();
2559 	cache = ipmr_cache_find(mrt, src, grp);
2560 	rcu_read_unlock();
2561 	if (!cache) {
2562 		err = -ENOENT;
2563 		goto errout_free;
2564 	}
2565 
2566 	skb = nlmsg_new(mroute_msgsize(false, mrt->maxvif), GFP_KERNEL);
2567 	if (!skb) {
2568 		err = -ENOBUFS;
2569 		goto errout_free;
2570 	}
2571 
2572 	err = ipmr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid,
2573 			       nlh->nlmsg_seq, cache,
2574 			       RTM_NEWROUTE, 0);
2575 	if (err < 0)
2576 		goto errout_free;
2577 
2578 	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2579 
2580 errout:
2581 	return err;
2582 
2583 errout_free:
2584 	kfree_skb(skb);
2585 	goto errout;
2586 }
2587 
2588 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2589 {
2590 	struct fib_dump_filter filter = {};
2591 	int err;
2592 
2593 	if (cb->strict_check) {
2594 		err = ip_valid_fib_dump_req(sock_net(skb->sk), cb->nlh,
2595 					    &filter, cb);
2596 		if (err < 0)
2597 			return err;
2598 	}
2599 
2600 	if (filter.table_id) {
2601 		struct mr_table *mrt;
2602 
2603 		mrt = ipmr_get_table(sock_net(skb->sk), filter.table_id);
2604 		if (!mrt) {
2605 			if (rtnl_msg_family(cb->nlh) != RTNL_FAMILY_IPMR)
2606 				return skb->len;
2607 
2608 			NL_SET_ERR_MSG(cb->extack, "ipv4: MR table does not exist");
2609 			return -ENOENT;
2610 		}
2611 		err = mr_table_dump(mrt, skb, cb, _ipmr_fill_mroute,
2612 				    &mfc_unres_lock, &filter);
2613 		return skb->len ? : err;
2614 	}
2615 
2616 	return mr_rtm_dumproute(skb, cb, ipmr_mr_table_iter,
2617 				_ipmr_fill_mroute, &mfc_unres_lock, &filter);
2618 }
2619 
2620 static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {
2621 	[RTA_SRC]	= { .type = NLA_U32 },
2622 	[RTA_DST]	= { .type = NLA_U32 },
2623 	[RTA_IIF]	= { .type = NLA_U32 },
2624 	[RTA_TABLE]	= { .type = NLA_U32 },
2625 	[RTA_MULTIPATH]	= { .len = sizeof(struct rtnexthop) },
2626 };
2627 
2628 static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol)
2629 {
2630 	switch (rtm_protocol) {
2631 	case RTPROT_STATIC:
2632 	case RTPROT_MROUTED:
2633 		return true;
2634 	}
2635 	return false;
2636 }
2637 
2638 static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc)
2639 {
2640 	struct rtnexthop *rtnh = nla_data(nla);
2641 	int remaining = nla_len(nla), vifi = 0;
2642 
2643 	while (rtnh_ok(rtnh, remaining)) {
2644 		mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops;
2645 		if (++vifi == MAXVIFS)
2646 			break;
2647 		rtnh = rtnh_next(rtnh, &remaining);
2648 	}
2649 
2650 	return remaining > 0 ? -EINVAL : vifi;
2651 }
2652 
2653 /* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */
2654 static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
2655 			    struct mfcctl *mfcc, int *mrtsock,
2656 			    struct mr_table **mrtret,
2657 			    struct netlink_ext_ack *extack)
2658 {
2659 	struct net_device *dev = NULL;
2660 	u32 tblid = RT_TABLE_DEFAULT;
2661 	struct mr_table *mrt;
2662 	struct nlattr *attr;
2663 	struct rtmsg *rtm;
2664 	int ret, rem;
2665 
2666 	ret = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
2667 					rtm_ipmr_policy, extack);
2668 	if (ret < 0)
2669 		goto out;
2670 	rtm = nlmsg_data(nlh);
2671 
2672 	ret = -EINVAL;
2673 	if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 ||
2674 	    rtm->rtm_type != RTN_MULTICAST ||
2675 	    rtm->rtm_scope != RT_SCOPE_UNIVERSE ||
2676 	    !ipmr_rtm_validate_proto(rtm->rtm_protocol))
2677 		goto out;
2678 
2679 	memset(mfcc, 0, sizeof(*mfcc));
2680 	mfcc->mfcc_parent = -1;
2681 	ret = 0;
2682 	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) {
2683 		switch (nla_type(attr)) {
2684 		case RTA_SRC:
2685 			mfcc->mfcc_origin.s_addr = nla_get_be32(attr);
2686 			break;
2687 		case RTA_DST:
2688 			mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr);
2689 			break;
2690 		case RTA_IIF:
2691 			dev = __dev_get_by_index(net, nla_get_u32(attr));
2692 			if (!dev) {
2693 				ret = -ENODEV;
2694 				goto out;
2695 			}
2696 			break;
2697 		case RTA_MULTIPATH:
2698 			if (ipmr_nla_get_ttls(attr, mfcc) < 0) {
2699 				ret = -EINVAL;
2700 				goto out;
2701 			}
2702 			break;
2703 		case RTA_PREFSRC:
2704 			ret = 1;
2705 			break;
2706 		case RTA_TABLE:
2707 			tblid = nla_get_u32(attr);
2708 			break;
2709 		}
2710 	}
2711 	mrt = ipmr_get_table(net, tblid);
2712 	if (!mrt) {
2713 		ret = -ENOENT;
2714 		goto out;
2715 	}
2716 	*mrtret = mrt;
2717 	*mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0;
2718 	if (dev)
2719 		mfcc->mfcc_parent = ipmr_find_vif(mrt, dev);
2720 
2721 out:
2722 	return ret;
2723 }
2724 
2725 /* takes care of both newroute and delroute */
2726 static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh,
2727 			  struct netlink_ext_ack *extack)
2728 {
2729 	struct net *net = sock_net(skb->sk);
2730 	int ret, mrtsock, parent;
2731 	struct mr_table *tbl;
2732 	struct mfcctl mfcc;
2733 
2734 	mrtsock = 0;
2735 	tbl = NULL;
2736 	ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl, extack);
2737 	if (ret < 0)
2738 		return ret;
2739 
2740 	parent = ret ? mfcc.mfcc_parent : -1;
2741 	if (nlh->nlmsg_type == RTM_NEWROUTE)
2742 		return ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent);
2743 	else
2744 		return ipmr_mfc_delete(tbl, &mfcc, parent);
2745 }
2746 
2747 static bool ipmr_fill_table(struct mr_table *mrt, struct sk_buff *skb)
2748 {
2749 	u32 queue_len = atomic_read(&mrt->cache_resolve_queue_len);
2750 
2751 	if (nla_put_u32(skb, IPMRA_TABLE_ID, mrt->id) ||
2752 	    nla_put_u32(skb, IPMRA_TABLE_CACHE_RES_QUEUE_LEN, queue_len) ||
2753 	    nla_put_s32(skb, IPMRA_TABLE_MROUTE_REG_VIF_NUM,
2754 			mrt->mroute_reg_vif_num) ||
2755 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_ASSERT,
2756 		       mrt->mroute_do_assert) ||
2757 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_PIM, mrt->mroute_do_pim) ||
2758 	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_WRVIFWHOLE,
2759 		       mrt->mroute_do_wrvifwhole))
2760 		return false;
2761 
2762 	return true;
2763 }
2764 
2765 static bool ipmr_fill_vif(struct mr_table *mrt, u32 vifid, struct sk_buff *skb)
2766 {
2767 	struct net_device *vif_dev;
2768 	struct nlattr *vif_nest;
2769 	struct vif_device *vif;
2770 
2771 	vif = &mrt->vif_table[vifid];
2772 	vif_dev = rtnl_dereference(vif->dev);
2773 	/* if the VIF doesn't exist just continue */
2774 	if (!vif_dev)
2775 		return true;
2776 
2777 	vif_nest = nla_nest_start_noflag(skb, IPMRA_VIF);
2778 	if (!vif_nest)
2779 		return false;
2780 
2781 	if (nla_put_u32(skb, IPMRA_VIFA_IFINDEX, vif_dev->ifindex) ||
2782 	    nla_put_u32(skb, IPMRA_VIFA_VIF_ID, vifid) ||
2783 	    nla_put_u16(skb, IPMRA_VIFA_FLAGS, vif->flags) ||
2784 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_IN, vif->bytes_in,
2785 			      IPMRA_VIFA_PAD) ||
2786 	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_OUT, vif->bytes_out,
2787 			      IPMRA_VIFA_PAD) ||
2788 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_IN, vif->pkt_in,
2789 			      IPMRA_VIFA_PAD) ||
2790 	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_OUT, vif->pkt_out,
2791 			      IPMRA_VIFA_PAD) ||
2792 	    nla_put_be32(skb, IPMRA_VIFA_LOCAL_ADDR, vif->local) ||
2793 	    nla_put_be32(skb, IPMRA_VIFA_REMOTE_ADDR, vif->remote)) {
2794 		nla_nest_cancel(skb, vif_nest);
2795 		return false;
2796 	}
2797 	nla_nest_end(skb, vif_nest);
2798 
2799 	return true;
2800 }
2801 
2802 static int ipmr_valid_dumplink(const struct nlmsghdr *nlh,
2803 			       struct netlink_ext_ack *extack)
2804 {
2805 	struct ifinfomsg *ifm;
2806 
2807 	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) {
2808 		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for ipmr link dump");
2809 		return -EINVAL;
2810 	}
2811 
2812 	if (nlmsg_attrlen(nlh, sizeof(*ifm))) {
2813 		NL_SET_ERR_MSG(extack, "Invalid data after header in ipmr link dump");
2814 		return -EINVAL;
2815 	}
2816 
2817 	ifm = nlmsg_data(nlh);
2818 	if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags ||
2819 	    ifm->ifi_change || ifm->ifi_index) {
2820 		NL_SET_ERR_MSG(extack, "Invalid values in header for ipmr link dump request");
2821 		return -EINVAL;
2822 	}
2823 
2824 	return 0;
2825 }
2826 
2827 static int ipmr_rtm_dumplink(struct sk_buff *skb, struct netlink_callback *cb)
2828 {
2829 	struct net *net = sock_net(skb->sk);
2830 	struct nlmsghdr *nlh = NULL;
2831 	unsigned int t = 0, s_t;
2832 	unsigned int e = 0, s_e;
2833 	struct mr_table *mrt;
2834 
2835 	if (cb->strict_check) {
2836 		int err = ipmr_valid_dumplink(cb->nlh, cb->extack);
2837 
2838 		if (err < 0)
2839 			return err;
2840 	}
2841 
2842 	s_t = cb->args[0];
2843 	s_e = cb->args[1];
2844 
2845 	ipmr_for_each_table(mrt, net) {
2846 		struct nlattr *vifs, *af;
2847 		struct ifinfomsg *hdr;
2848 		u32 i;
2849 
2850 		if (t < s_t)
2851 			goto skip_table;
2852 		nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
2853 				cb->nlh->nlmsg_seq, RTM_NEWLINK,
2854 				sizeof(*hdr), NLM_F_MULTI);
2855 		if (!nlh)
2856 			break;
2857 
2858 		hdr = nlmsg_data(nlh);
2859 		memset(hdr, 0, sizeof(*hdr));
2860 		hdr->ifi_family = RTNL_FAMILY_IPMR;
2861 
2862 		af = nla_nest_start_noflag(skb, IFLA_AF_SPEC);
2863 		if (!af) {
2864 			nlmsg_cancel(skb, nlh);
2865 			goto out;
2866 		}
2867 
2868 		if (!ipmr_fill_table(mrt, skb)) {
2869 			nlmsg_cancel(skb, nlh);
2870 			goto out;
2871 		}
2872 
2873 		vifs = nla_nest_start_noflag(skb, IPMRA_TABLE_VIFS);
2874 		if (!vifs) {
2875 			nla_nest_end(skb, af);
2876 			nlmsg_end(skb, nlh);
2877 			goto out;
2878 		}
2879 		for (i = 0; i < mrt->maxvif; i++) {
2880 			if (e < s_e)
2881 				goto skip_entry;
2882 			if (!ipmr_fill_vif(mrt, i, skb)) {
2883 				nla_nest_end(skb, vifs);
2884 				nla_nest_end(skb, af);
2885 				nlmsg_end(skb, nlh);
2886 				goto out;
2887 			}
2888 skip_entry:
2889 			e++;
2890 		}
2891 		s_e = 0;
2892 		e = 0;
2893 		nla_nest_end(skb, vifs);
2894 		nla_nest_end(skb, af);
2895 		nlmsg_end(skb, nlh);
2896 skip_table:
2897 		t++;
2898 	}
2899 
2900 out:
2901 	cb->args[1] = e;
2902 	cb->args[0] = t;
2903 
2904 	return skb->len;
2905 }
2906 
2907 #ifdef CONFIG_PROC_FS
2908 /* The /proc interfaces to multicast routing :
2909  * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2910  */
2911 
2912 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2913 	__acquires(RCU)
2914 {
2915 	struct mr_vif_iter *iter = seq->private;
2916 	struct net *net = seq_file_net(seq);
2917 	struct mr_table *mrt;
2918 
2919 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2920 	if (!mrt)
2921 		return ERR_PTR(-ENOENT);
2922 
2923 	iter->mrt = mrt;
2924 
2925 	rcu_read_lock();
2926 	return mr_vif_seq_start(seq, pos);
2927 }
2928 
2929 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2930 	__releases(RCU)
2931 {
2932 	rcu_read_unlock();
2933 }
2934 
2935 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2936 {
2937 	struct mr_vif_iter *iter = seq->private;
2938 	struct mr_table *mrt = iter->mrt;
2939 
2940 	if (v == SEQ_START_TOKEN) {
2941 		seq_puts(seq,
2942 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2943 	} else {
2944 		const struct vif_device *vif = v;
2945 		const struct net_device *vif_dev;
2946 		const char *name;
2947 
2948 		vif_dev = vif_dev_read(vif);
2949 		name = vif_dev ? vif_dev->name : "none";
2950 		seq_printf(seq,
2951 			   "%2td %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2952 			   vif - mrt->vif_table,
2953 			   name, vif->bytes_in, vif->pkt_in,
2954 			   vif->bytes_out, vif->pkt_out,
2955 			   vif->flags, vif->local, vif->remote);
2956 	}
2957 	return 0;
2958 }
2959 
2960 static const struct seq_operations ipmr_vif_seq_ops = {
2961 	.start = ipmr_vif_seq_start,
2962 	.next  = mr_vif_seq_next,
2963 	.stop  = ipmr_vif_seq_stop,
2964 	.show  = ipmr_vif_seq_show,
2965 };
2966 
2967 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2968 {
2969 	struct net *net = seq_file_net(seq);
2970 	struct mr_table *mrt;
2971 
2972 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2973 	if (!mrt)
2974 		return ERR_PTR(-ENOENT);
2975 
2976 	return mr_mfc_seq_start(seq, pos, mrt, &mfc_unres_lock);
2977 }
2978 
2979 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2980 {
2981 	int n;
2982 
2983 	if (v == SEQ_START_TOKEN) {
2984 		seq_puts(seq,
2985 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2986 	} else {
2987 		const struct mfc_cache *mfc = v;
2988 		const struct mr_mfc_iter *it = seq->private;
2989 		const struct mr_table *mrt = it->mrt;
2990 
2991 		seq_printf(seq, "%08X %08X %-3hd",
2992 			   (__force u32) mfc->mfc_mcastgrp,
2993 			   (__force u32) mfc->mfc_origin,
2994 			   mfc->_c.mfc_parent);
2995 
2996 		if (it->cache != &mrt->mfc_unres_queue) {
2997 			seq_printf(seq, " %8lu %8lu %8lu",
2998 				   mfc->_c.mfc_un.res.pkt,
2999 				   mfc->_c.mfc_un.res.bytes,
3000 				   mfc->_c.mfc_un.res.wrong_if);
3001 			for (n = mfc->_c.mfc_un.res.minvif;
3002 			     n < mfc->_c.mfc_un.res.maxvif; n++) {
3003 				if (VIF_EXISTS(mrt, n) &&
3004 				    mfc->_c.mfc_un.res.ttls[n] < 255)
3005 					seq_printf(seq,
3006 					   " %2d:%-3d",
3007 					   n, mfc->_c.mfc_un.res.ttls[n]);
3008 			}
3009 		} else {
3010 			/* unresolved mfc_caches don't contain
3011 			 * pkt, bytes and wrong_if values
3012 			 */
3013 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
3014 		}
3015 		seq_putc(seq, '\n');
3016 	}
3017 	return 0;
3018 }
3019 
3020 static const struct seq_operations ipmr_mfc_seq_ops = {
3021 	.start = ipmr_mfc_seq_start,
3022 	.next  = mr_mfc_seq_next,
3023 	.stop  = mr_mfc_seq_stop,
3024 	.show  = ipmr_mfc_seq_show,
3025 };
3026 #endif
3027 
3028 #ifdef CONFIG_IP_PIMSM_V2
3029 static const struct net_protocol pim_protocol = {
3030 	.handler	=	pim_rcv,
3031 };
3032 #endif
3033 
3034 static unsigned int ipmr_seq_read(struct net *net)
3035 {
3036 	ASSERT_RTNL();
3037 
3038 	return net->ipv4.ipmr_seq + ipmr_rules_seq_read(net);
3039 }
3040 
3041 static int ipmr_dump(struct net *net, struct notifier_block *nb,
3042 		     struct netlink_ext_ack *extack)
3043 {
3044 	return mr_dump(net, nb, RTNL_FAMILY_IPMR, ipmr_rules_dump,
3045 		       ipmr_mr_table_iter, extack);
3046 }
3047 
3048 static const struct fib_notifier_ops ipmr_notifier_ops_template = {
3049 	.family		= RTNL_FAMILY_IPMR,
3050 	.fib_seq_read	= ipmr_seq_read,
3051 	.fib_dump	= ipmr_dump,
3052 	.owner		= THIS_MODULE,
3053 };
3054 
3055 static int __net_init ipmr_notifier_init(struct net *net)
3056 {
3057 	struct fib_notifier_ops *ops;
3058 
3059 	net->ipv4.ipmr_seq = 0;
3060 
3061 	ops = fib_notifier_ops_register(&ipmr_notifier_ops_template, net);
3062 	if (IS_ERR(ops))
3063 		return PTR_ERR(ops);
3064 	net->ipv4.ipmr_notifier_ops = ops;
3065 
3066 	return 0;
3067 }
3068 
3069 static void __net_exit ipmr_notifier_exit(struct net *net)
3070 {
3071 	fib_notifier_ops_unregister(net->ipv4.ipmr_notifier_ops);
3072 	net->ipv4.ipmr_notifier_ops = NULL;
3073 }
3074 
3075 /* Setup for IP multicast routing */
3076 static int __net_init ipmr_net_init(struct net *net)
3077 {
3078 	int err;
3079 
3080 	err = ipmr_notifier_init(net);
3081 	if (err)
3082 		goto ipmr_notifier_fail;
3083 
3084 	err = ipmr_rules_init(net);
3085 	if (err < 0)
3086 		goto ipmr_rules_fail;
3087 
3088 #ifdef CONFIG_PROC_FS
3089 	err = -ENOMEM;
3090 	if (!proc_create_net("ip_mr_vif", 0, net->proc_net, &ipmr_vif_seq_ops,
3091 			sizeof(struct mr_vif_iter)))
3092 		goto proc_vif_fail;
3093 	if (!proc_create_net("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_seq_ops,
3094 			sizeof(struct mr_mfc_iter)))
3095 		goto proc_cache_fail;
3096 #endif
3097 	return 0;
3098 
3099 #ifdef CONFIG_PROC_FS
3100 proc_cache_fail:
3101 	remove_proc_entry("ip_mr_vif", net->proc_net);
3102 proc_vif_fail:
3103 	rtnl_lock();
3104 	ipmr_rules_exit(net);
3105 	rtnl_unlock();
3106 #endif
3107 ipmr_rules_fail:
3108 	ipmr_notifier_exit(net);
3109 ipmr_notifier_fail:
3110 	return err;
3111 }
3112 
3113 static void __net_exit ipmr_net_exit(struct net *net)
3114 {
3115 #ifdef CONFIG_PROC_FS
3116 	remove_proc_entry("ip_mr_cache", net->proc_net);
3117 	remove_proc_entry("ip_mr_vif", net->proc_net);
3118 #endif
3119 	ipmr_notifier_exit(net);
3120 }
3121 
3122 static void __net_exit ipmr_net_exit_batch(struct list_head *net_list)
3123 {
3124 	struct net *net;
3125 
3126 	rtnl_lock();
3127 	list_for_each_entry(net, net_list, exit_list)
3128 		ipmr_rules_exit(net);
3129 	rtnl_unlock();
3130 }
3131 
3132 static struct pernet_operations ipmr_net_ops = {
3133 	.init = ipmr_net_init,
3134 	.exit = ipmr_net_exit,
3135 	.exit_batch = ipmr_net_exit_batch,
3136 };
3137 
3138 int __init ip_mr_init(void)
3139 {
3140 	int err;
3141 
3142 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
3143 				       sizeof(struct mfc_cache),
3144 				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
3145 				       NULL);
3146 
3147 	err = register_pernet_subsys(&ipmr_net_ops);
3148 	if (err)
3149 		goto reg_pernet_fail;
3150 
3151 	err = register_netdevice_notifier(&ip_mr_notifier);
3152 	if (err)
3153 		goto reg_notif_fail;
3154 #ifdef CONFIG_IP_PIMSM_V2
3155 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
3156 		pr_err("%s: can't add PIM protocol\n", __func__);
3157 		err = -EAGAIN;
3158 		goto add_proto_fail;
3159 	}
3160 #endif
3161 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
3162 		      ipmr_rtm_getroute, ipmr_rtm_dumproute, 0);
3163 	rtnl_register(RTNL_FAMILY_IPMR, RTM_NEWROUTE,
3164 		      ipmr_rtm_route, NULL, 0);
3165 	rtnl_register(RTNL_FAMILY_IPMR, RTM_DELROUTE,
3166 		      ipmr_rtm_route, NULL, 0);
3167 
3168 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETLINK,
3169 		      NULL, ipmr_rtm_dumplink, 0);
3170 	return 0;
3171 
3172 #ifdef CONFIG_IP_PIMSM_V2
3173 add_proto_fail:
3174 	unregister_netdevice_notifier(&ip_mr_notifier);
3175 #endif
3176 reg_notif_fail:
3177 	unregister_pernet_subsys(&ipmr_net_ops);
3178 reg_pernet_fail:
3179 	kmem_cache_destroy(mrt_cachep);
3180 	return err;
3181 }
3182