xref: /openbmc/linux/net/ipv6/ip6mr.c (revision c8ec3743)
1 /*
2  *	Linux IPv6 multicast routing support for BSD pim6sd
3  *	Based on net/ipv4/ipmr.c.
4  *
5  *	(c) 2004 Mickael Hoerdt, <hoerdt@clarinet.u-strasbg.fr>
6  *		LSIIT Laboratory, Strasbourg, France
7  *	(c) 2004 Jean-Philippe Andriot, <jean-philippe.andriot@6WIND.com>
8  *		6WIND, Paris, France
9  *	Copyright (C)2007,2008 USAGI/WIDE Project
10  *		YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
11  *
12  *	This program is free software; you can redistribute it and/or
13  *	modify it under the terms of the GNU General Public License
14  *	as published by the Free Software Foundation; either version
15  *	2 of the License, or (at your option) any later version.
16  *
17  */
18 
19 #include <linux/uaccess.h>
20 #include <linux/types.h>
21 #include <linux/sched.h>
22 #include <linux/errno.h>
23 #include <linux/mm.h>
24 #include <linux/kernel.h>
25 #include <linux/fcntl.h>
26 #include <linux/stat.h>
27 #include <linux/socket.h>
28 #include <linux/inet.h>
29 #include <linux/netdevice.h>
30 #include <linux/inetdevice.h>
31 #include <linux/proc_fs.h>
32 #include <linux/seq_file.h>
33 #include <linux/init.h>
34 #include <linux/compat.h>
35 #include <linux/rhashtable.h>
36 #include <net/protocol.h>
37 #include <linux/skbuff.h>
38 #include <net/raw.h>
39 #include <linux/notifier.h>
40 #include <linux/if_arp.h>
41 #include <net/checksum.h>
42 #include <net/netlink.h>
43 #include <net/fib_rules.h>
44 
45 #include <net/ipv6.h>
46 #include <net/ip6_route.h>
47 #include <linux/mroute6.h>
48 #include <linux/pim.h>
49 #include <net/addrconf.h>
50 #include <linux/netfilter_ipv6.h>
51 #include <linux/export.h>
52 #include <net/ip6_checksum.h>
53 #include <linux/netconf.h>
54 #include <net/ip_tunnels.h>
55 
56 #include <linux/nospec.h>
57 
58 struct ip6mr_rule {
59 	struct fib_rule		common;
60 };
61 
62 struct ip6mr_result {
63 	struct mr_table	*mrt;
64 };
65 
66 /* Big lock, protecting vif table, mrt cache and mroute socket state.
67    Note that the changes are semaphored via rtnl_lock.
68  */
69 
70 static DEFINE_RWLOCK(mrt_lock);
71 
72 /* Multicast router control variables */
73 
74 /* Special spinlock for queue of unresolved entries */
75 static DEFINE_SPINLOCK(mfc_unres_lock);
76 
77 /* We return to original Alan's scheme. Hash table of resolved
78    entries is changed only in process context and protected
79    with weak lock mrt_lock. Queue of unresolved entries is protected
80    with strong spinlock mfc_unres_lock.
81 
82    In this case data path is free of exclusive locks at all.
83  */
84 
85 static struct kmem_cache *mrt_cachep __read_mostly;
86 
87 static struct mr_table *ip6mr_new_table(struct net *net, u32 id);
88 static void ip6mr_free_table(struct mr_table *mrt);
89 
90 static void ip6_mr_forward(struct net *net, struct mr_table *mrt,
91 			   struct net_device *dev, struct sk_buff *skb,
92 			   struct mfc6_cache *cache);
93 static int ip6mr_cache_report(struct mr_table *mrt, struct sk_buff *pkt,
94 			      mifi_t mifi, int assert);
95 static void mr6_netlink_event(struct mr_table *mrt, struct mfc6_cache *mfc,
96 			      int cmd);
97 static void mrt6msg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
98 static int ip6mr_rtm_dumproute(struct sk_buff *skb,
99 			       struct netlink_callback *cb);
100 static void mroute_clean_tables(struct mr_table *mrt, bool all);
101 static void ipmr_expire_process(struct timer_list *t);
102 
103 #ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
104 #define ip6mr_for_each_table(mrt, net) \
105 	list_for_each_entry_rcu(mrt, &net->ipv6.mr6_tables, list)
106 
107 static struct mr_table *ip6mr_mr_table_iter(struct net *net,
108 					    struct mr_table *mrt)
109 {
110 	struct mr_table *ret;
111 
112 	if (!mrt)
113 		ret = list_entry_rcu(net->ipv6.mr6_tables.next,
114 				     struct mr_table, list);
115 	else
116 		ret = list_entry_rcu(mrt->list.next,
117 				     struct mr_table, list);
118 
119 	if (&ret->list == &net->ipv6.mr6_tables)
120 		return NULL;
121 	return ret;
122 }
123 
124 static struct mr_table *ip6mr_get_table(struct net *net, u32 id)
125 {
126 	struct mr_table *mrt;
127 
128 	ip6mr_for_each_table(mrt, net) {
129 		if (mrt->id == id)
130 			return mrt;
131 	}
132 	return NULL;
133 }
134 
135 static int ip6mr_fib_lookup(struct net *net, struct flowi6 *flp6,
136 			    struct mr_table **mrt)
137 {
138 	int err;
139 	struct ip6mr_result res;
140 	struct fib_lookup_arg arg = {
141 		.result = &res,
142 		.flags = FIB_LOOKUP_NOREF,
143 	};
144 
145 	/* update flow if oif or iif point to device enslaved to l3mdev */
146 	l3mdev_update_flow(net, flowi6_to_flowi(flp6));
147 
148 	err = fib_rules_lookup(net->ipv6.mr6_rules_ops,
149 			       flowi6_to_flowi(flp6), 0, &arg);
150 	if (err < 0)
151 		return err;
152 	*mrt = res.mrt;
153 	return 0;
154 }
155 
156 static int ip6mr_rule_action(struct fib_rule *rule, struct flowi *flp,
157 			     int flags, struct fib_lookup_arg *arg)
158 {
159 	struct ip6mr_result *res = arg->result;
160 	struct mr_table *mrt;
161 
162 	switch (rule->action) {
163 	case FR_ACT_TO_TBL:
164 		break;
165 	case FR_ACT_UNREACHABLE:
166 		return -ENETUNREACH;
167 	case FR_ACT_PROHIBIT:
168 		return -EACCES;
169 	case FR_ACT_BLACKHOLE:
170 	default:
171 		return -EINVAL;
172 	}
173 
174 	arg->table = fib_rule_get_table(rule, arg);
175 
176 	mrt = ip6mr_get_table(rule->fr_net, arg->table);
177 	if (!mrt)
178 		return -EAGAIN;
179 	res->mrt = mrt;
180 	return 0;
181 }
182 
183 static int ip6mr_rule_match(struct fib_rule *rule, struct flowi *flp, int flags)
184 {
185 	return 1;
186 }
187 
188 static const struct nla_policy ip6mr_rule_policy[FRA_MAX + 1] = {
189 	FRA_GENERIC_POLICY,
190 };
191 
192 static int ip6mr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
193 				struct fib_rule_hdr *frh, struct nlattr **tb,
194 				struct netlink_ext_ack *extack)
195 {
196 	return 0;
197 }
198 
199 static int ip6mr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
200 			      struct nlattr **tb)
201 {
202 	return 1;
203 }
204 
205 static int ip6mr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
206 			   struct fib_rule_hdr *frh)
207 {
208 	frh->dst_len = 0;
209 	frh->src_len = 0;
210 	frh->tos     = 0;
211 	return 0;
212 }
213 
214 static const struct fib_rules_ops __net_initconst ip6mr_rules_ops_template = {
215 	.family		= RTNL_FAMILY_IP6MR,
216 	.rule_size	= sizeof(struct ip6mr_rule),
217 	.addr_size	= sizeof(struct in6_addr),
218 	.action		= ip6mr_rule_action,
219 	.match		= ip6mr_rule_match,
220 	.configure	= ip6mr_rule_configure,
221 	.compare	= ip6mr_rule_compare,
222 	.fill		= ip6mr_rule_fill,
223 	.nlgroup	= RTNLGRP_IPV6_RULE,
224 	.policy		= ip6mr_rule_policy,
225 	.owner		= THIS_MODULE,
226 };
227 
228 static int __net_init ip6mr_rules_init(struct net *net)
229 {
230 	struct fib_rules_ops *ops;
231 	struct mr_table *mrt;
232 	int err;
233 
234 	ops = fib_rules_register(&ip6mr_rules_ops_template, net);
235 	if (IS_ERR(ops))
236 		return PTR_ERR(ops);
237 
238 	INIT_LIST_HEAD(&net->ipv6.mr6_tables);
239 
240 	mrt = ip6mr_new_table(net, RT6_TABLE_DFLT);
241 	if (IS_ERR(mrt)) {
242 		err = PTR_ERR(mrt);
243 		goto err1;
244 	}
245 
246 	err = fib_default_rule_add(ops, 0x7fff, RT6_TABLE_DFLT, 0);
247 	if (err < 0)
248 		goto err2;
249 
250 	net->ipv6.mr6_rules_ops = ops;
251 	return 0;
252 
253 err2:
254 	ip6mr_free_table(mrt);
255 err1:
256 	fib_rules_unregister(ops);
257 	return err;
258 }
259 
260 static void __net_exit ip6mr_rules_exit(struct net *net)
261 {
262 	struct mr_table *mrt, *next;
263 
264 	rtnl_lock();
265 	list_for_each_entry_safe(mrt, next, &net->ipv6.mr6_tables, list) {
266 		list_del(&mrt->list);
267 		ip6mr_free_table(mrt);
268 	}
269 	fib_rules_unregister(net->ipv6.mr6_rules_ops);
270 	rtnl_unlock();
271 }
272 
273 static int ip6mr_rules_dump(struct net *net, struct notifier_block *nb)
274 {
275 	return fib_rules_dump(net, nb, RTNL_FAMILY_IP6MR);
276 }
277 
278 static unsigned int ip6mr_rules_seq_read(struct net *net)
279 {
280 	return fib_rules_seq_read(net, RTNL_FAMILY_IP6MR);
281 }
282 
283 bool ip6mr_rule_default(const struct fib_rule *rule)
284 {
285 	return fib_rule_matchall(rule) && rule->action == FR_ACT_TO_TBL &&
286 	       rule->table == RT6_TABLE_DFLT && !rule->l3mdev;
287 }
288 EXPORT_SYMBOL(ip6mr_rule_default);
289 #else
290 #define ip6mr_for_each_table(mrt, net) \
291 	for (mrt = net->ipv6.mrt6; mrt; mrt = NULL)
292 
293 static struct mr_table *ip6mr_mr_table_iter(struct net *net,
294 					    struct mr_table *mrt)
295 {
296 	if (!mrt)
297 		return net->ipv6.mrt6;
298 	return NULL;
299 }
300 
301 static struct mr_table *ip6mr_get_table(struct net *net, u32 id)
302 {
303 	return net->ipv6.mrt6;
304 }
305 
306 static int ip6mr_fib_lookup(struct net *net, struct flowi6 *flp6,
307 			    struct mr_table **mrt)
308 {
309 	*mrt = net->ipv6.mrt6;
310 	return 0;
311 }
312 
313 static int __net_init ip6mr_rules_init(struct net *net)
314 {
315 	struct mr_table *mrt;
316 
317 	mrt = ip6mr_new_table(net, RT6_TABLE_DFLT);
318 	if (IS_ERR(mrt))
319 		return PTR_ERR(mrt);
320 	net->ipv6.mrt6 = mrt;
321 	return 0;
322 }
323 
324 static void __net_exit ip6mr_rules_exit(struct net *net)
325 {
326 	rtnl_lock();
327 	ip6mr_free_table(net->ipv6.mrt6);
328 	net->ipv6.mrt6 = NULL;
329 	rtnl_unlock();
330 }
331 
332 static int ip6mr_rules_dump(struct net *net, struct notifier_block *nb)
333 {
334 	return 0;
335 }
336 
337 static unsigned int ip6mr_rules_seq_read(struct net *net)
338 {
339 	return 0;
340 }
341 #endif
342 
343 static int ip6mr_hash_cmp(struct rhashtable_compare_arg *arg,
344 			  const void *ptr)
345 {
346 	const struct mfc6_cache_cmp_arg *cmparg = arg->key;
347 	struct mfc6_cache *c = (struct mfc6_cache *)ptr;
348 
349 	return !ipv6_addr_equal(&c->mf6c_mcastgrp, &cmparg->mf6c_mcastgrp) ||
350 	       !ipv6_addr_equal(&c->mf6c_origin, &cmparg->mf6c_origin);
351 }
352 
353 static const struct rhashtable_params ip6mr_rht_params = {
354 	.head_offset = offsetof(struct mr_mfc, mnode),
355 	.key_offset = offsetof(struct mfc6_cache, cmparg),
356 	.key_len = sizeof(struct mfc6_cache_cmp_arg),
357 	.nelem_hint = 3,
358 	.locks_mul = 1,
359 	.obj_cmpfn = ip6mr_hash_cmp,
360 	.automatic_shrinking = true,
361 };
362 
363 static void ip6mr_new_table_set(struct mr_table *mrt,
364 				struct net *net)
365 {
366 #ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
367 	list_add_tail_rcu(&mrt->list, &net->ipv6.mr6_tables);
368 #endif
369 }
370 
371 static struct mfc6_cache_cmp_arg ip6mr_mr_table_ops_cmparg_any = {
372 	.mf6c_origin = IN6ADDR_ANY_INIT,
373 	.mf6c_mcastgrp = IN6ADDR_ANY_INIT,
374 };
375 
376 static struct mr_table_ops ip6mr_mr_table_ops = {
377 	.rht_params = &ip6mr_rht_params,
378 	.cmparg_any = &ip6mr_mr_table_ops_cmparg_any,
379 };
380 
381 static struct mr_table *ip6mr_new_table(struct net *net, u32 id)
382 {
383 	struct mr_table *mrt;
384 
385 	mrt = ip6mr_get_table(net, id);
386 	if (mrt)
387 		return mrt;
388 
389 	return mr_table_alloc(net, id, &ip6mr_mr_table_ops,
390 			      ipmr_expire_process, ip6mr_new_table_set);
391 }
392 
393 static void ip6mr_free_table(struct mr_table *mrt)
394 {
395 	del_timer_sync(&mrt->ipmr_expire_timer);
396 	mroute_clean_tables(mrt, true);
397 	rhltable_destroy(&mrt->mfc_hash);
398 	kfree(mrt);
399 }
400 
401 #ifdef CONFIG_PROC_FS
402 /* The /proc interfaces to multicast routing
403  * /proc/ip6_mr_cache /proc/ip6_mr_vif
404  */
405 
406 static void *ip6mr_vif_seq_start(struct seq_file *seq, loff_t *pos)
407 	__acquires(mrt_lock)
408 {
409 	struct mr_vif_iter *iter = seq->private;
410 	struct net *net = seq_file_net(seq);
411 	struct mr_table *mrt;
412 
413 	mrt = ip6mr_get_table(net, RT6_TABLE_DFLT);
414 	if (!mrt)
415 		return ERR_PTR(-ENOENT);
416 
417 	iter->mrt = mrt;
418 
419 	read_lock(&mrt_lock);
420 	return mr_vif_seq_start(seq, pos);
421 }
422 
423 static void ip6mr_vif_seq_stop(struct seq_file *seq, void *v)
424 	__releases(mrt_lock)
425 {
426 	read_unlock(&mrt_lock);
427 }
428 
429 static int ip6mr_vif_seq_show(struct seq_file *seq, void *v)
430 {
431 	struct mr_vif_iter *iter = seq->private;
432 	struct mr_table *mrt = iter->mrt;
433 
434 	if (v == SEQ_START_TOKEN) {
435 		seq_puts(seq,
436 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags\n");
437 	} else {
438 		const struct vif_device *vif = v;
439 		const char *name = vif->dev ? vif->dev->name : "none";
440 
441 		seq_printf(seq,
442 			   "%2td %-10s %8ld %7ld  %8ld %7ld %05X\n",
443 			   vif - mrt->vif_table,
444 			   name, vif->bytes_in, vif->pkt_in,
445 			   vif->bytes_out, vif->pkt_out,
446 			   vif->flags);
447 	}
448 	return 0;
449 }
450 
451 static const struct seq_operations ip6mr_vif_seq_ops = {
452 	.start = ip6mr_vif_seq_start,
453 	.next  = mr_vif_seq_next,
454 	.stop  = ip6mr_vif_seq_stop,
455 	.show  = ip6mr_vif_seq_show,
456 };
457 
458 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
459 {
460 	struct net *net = seq_file_net(seq);
461 	struct mr_table *mrt;
462 
463 	mrt = ip6mr_get_table(net, RT6_TABLE_DFLT);
464 	if (!mrt)
465 		return ERR_PTR(-ENOENT);
466 
467 	return mr_mfc_seq_start(seq, pos, mrt, &mfc_unres_lock);
468 }
469 
470 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
471 {
472 	int n;
473 
474 	if (v == SEQ_START_TOKEN) {
475 		seq_puts(seq,
476 			 "Group                            "
477 			 "Origin                           "
478 			 "Iif      Pkts  Bytes     Wrong  Oifs\n");
479 	} else {
480 		const struct mfc6_cache *mfc = v;
481 		const struct mr_mfc_iter *it = seq->private;
482 		struct mr_table *mrt = it->mrt;
483 
484 		seq_printf(seq, "%pI6 %pI6 %-3hd",
485 			   &mfc->mf6c_mcastgrp, &mfc->mf6c_origin,
486 			   mfc->_c.mfc_parent);
487 
488 		if (it->cache != &mrt->mfc_unres_queue) {
489 			seq_printf(seq, " %8lu %8lu %8lu",
490 				   mfc->_c.mfc_un.res.pkt,
491 				   mfc->_c.mfc_un.res.bytes,
492 				   mfc->_c.mfc_un.res.wrong_if);
493 			for (n = mfc->_c.mfc_un.res.minvif;
494 			     n < mfc->_c.mfc_un.res.maxvif; n++) {
495 				if (VIF_EXISTS(mrt, n) &&
496 				    mfc->_c.mfc_un.res.ttls[n] < 255)
497 					seq_printf(seq,
498 						   " %2d:%-3d", n,
499 						   mfc->_c.mfc_un.res.ttls[n]);
500 			}
501 		} else {
502 			/* unresolved mfc_caches don't contain
503 			 * pkt, bytes and wrong_if values
504 			 */
505 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
506 		}
507 		seq_putc(seq, '\n');
508 	}
509 	return 0;
510 }
511 
512 static const struct seq_operations ipmr_mfc_seq_ops = {
513 	.start = ipmr_mfc_seq_start,
514 	.next  = mr_mfc_seq_next,
515 	.stop  = mr_mfc_seq_stop,
516 	.show  = ipmr_mfc_seq_show,
517 };
518 #endif
519 
520 #ifdef CONFIG_IPV6_PIMSM_V2
521 
522 static int pim6_rcv(struct sk_buff *skb)
523 {
524 	struct pimreghdr *pim;
525 	struct ipv6hdr   *encap;
526 	struct net_device  *reg_dev = NULL;
527 	struct net *net = dev_net(skb->dev);
528 	struct mr_table *mrt;
529 	struct flowi6 fl6 = {
530 		.flowi6_iif	= skb->dev->ifindex,
531 		.flowi6_mark	= skb->mark,
532 	};
533 	int reg_vif_num;
534 
535 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap)))
536 		goto drop;
537 
538 	pim = (struct pimreghdr *)skb_transport_header(skb);
539 	if (pim->type != ((PIM_VERSION << 4) | PIM_TYPE_REGISTER) ||
540 	    (pim->flags & PIM_NULL_REGISTER) ||
541 	    (csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
542 			     sizeof(*pim), IPPROTO_PIM,
543 			     csum_partial((void *)pim, sizeof(*pim), 0)) &&
544 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
545 		goto drop;
546 
547 	/* check if the inner packet is destined to mcast group */
548 	encap = (struct ipv6hdr *)(skb_transport_header(skb) +
549 				   sizeof(*pim));
550 
551 	if (!ipv6_addr_is_multicast(&encap->daddr) ||
552 	    encap->payload_len == 0 ||
553 	    ntohs(encap->payload_len) + sizeof(*pim) > skb->len)
554 		goto drop;
555 
556 	if (ip6mr_fib_lookup(net, &fl6, &mrt) < 0)
557 		goto drop;
558 	reg_vif_num = mrt->mroute_reg_vif_num;
559 
560 	read_lock(&mrt_lock);
561 	if (reg_vif_num >= 0)
562 		reg_dev = mrt->vif_table[reg_vif_num].dev;
563 	if (reg_dev)
564 		dev_hold(reg_dev);
565 	read_unlock(&mrt_lock);
566 
567 	if (!reg_dev)
568 		goto drop;
569 
570 	skb->mac_header = skb->network_header;
571 	skb_pull(skb, (u8 *)encap - skb->data);
572 	skb_reset_network_header(skb);
573 	skb->protocol = htons(ETH_P_IPV6);
574 	skb->ip_summed = CHECKSUM_NONE;
575 
576 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
577 
578 	netif_rx(skb);
579 
580 	dev_put(reg_dev);
581 	return 0;
582  drop:
583 	kfree_skb(skb);
584 	return 0;
585 }
586 
587 static const struct inet6_protocol pim6_protocol = {
588 	.handler	=	pim6_rcv,
589 };
590 
591 /* Service routines creating virtual interfaces: PIMREG */
592 
593 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb,
594 				      struct net_device *dev)
595 {
596 	struct net *net = dev_net(dev);
597 	struct mr_table *mrt;
598 	struct flowi6 fl6 = {
599 		.flowi6_oif	= dev->ifindex,
600 		.flowi6_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
601 		.flowi6_mark	= skb->mark,
602 	};
603 
604 	if (!pskb_inet_may_pull(skb))
605 		goto tx_err;
606 
607 	if (ip6mr_fib_lookup(net, &fl6, &mrt) < 0)
608 		goto tx_err;
609 
610 	read_lock(&mrt_lock);
611 	dev->stats.tx_bytes += skb->len;
612 	dev->stats.tx_packets++;
613 	ip6mr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, MRT6MSG_WHOLEPKT);
614 	read_unlock(&mrt_lock);
615 	kfree_skb(skb);
616 	return NETDEV_TX_OK;
617 
618 tx_err:
619 	dev->stats.tx_errors++;
620 	kfree_skb(skb);
621 	return NETDEV_TX_OK;
622 }
623 
624 static int reg_vif_get_iflink(const struct net_device *dev)
625 {
626 	return 0;
627 }
628 
629 static const struct net_device_ops reg_vif_netdev_ops = {
630 	.ndo_start_xmit	= reg_vif_xmit,
631 	.ndo_get_iflink = reg_vif_get_iflink,
632 };
633 
634 static void reg_vif_setup(struct net_device *dev)
635 {
636 	dev->type		= ARPHRD_PIMREG;
637 	dev->mtu		= 1500 - sizeof(struct ipv6hdr) - 8;
638 	dev->flags		= IFF_NOARP;
639 	dev->netdev_ops		= &reg_vif_netdev_ops;
640 	dev->needs_free_netdev	= true;
641 	dev->features		|= NETIF_F_NETNS_LOCAL;
642 }
643 
644 static struct net_device *ip6mr_reg_vif(struct net *net, struct mr_table *mrt)
645 {
646 	struct net_device *dev;
647 	char name[IFNAMSIZ];
648 
649 	if (mrt->id == RT6_TABLE_DFLT)
650 		sprintf(name, "pim6reg");
651 	else
652 		sprintf(name, "pim6reg%u", mrt->id);
653 
654 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
655 	if (!dev)
656 		return NULL;
657 
658 	dev_net_set(dev, net);
659 
660 	if (register_netdevice(dev)) {
661 		free_netdev(dev);
662 		return NULL;
663 	}
664 
665 	if (dev_open(dev, NULL))
666 		goto failure;
667 
668 	dev_hold(dev);
669 	return dev;
670 
671 failure:
672 	unregister_netdevice(dev);
673 	return NULL;
674 }
675 #endif
676 
677 static int call_ip6mr_vif_entry_notifiers(struct net *net,
678 					  enum fib_event_type event_type,
679 					  struct vif_device *vif,
680 					  mifi_t vif_index, u32 tb_id)
681 {
682 	return mr_call_vif_notifiers(net, RTNL_FAMILY_IP6MR, event_type,
683 				     vif, vif_index, tb_id,
684 				     &net->ipv6.ipmr_seq);
685 }
686 
687 static int call_ip6mr_mfc_entry_notifiers(struct net *net,
688 					  enum fib_event_type event_type,
689 					  struct mfc6_cache *mfc, u32 tb_id)
690 {
691 	return mr_call_mfc_notifiers(net, RTNL_FAMILY_IP6MR, event_type,
692 				     &mfc->_c, tb_id, &net->ipv6.ipmr_seq);
693 }
694 
695 /* Delete a VIF entry */
696 static int mif6_delete(struct mr_table *mrt, int vifi, int notify,
697 		       struct list_head *head)
698 {
699 	struct vif_device *v;
700 	struct net_device *dev;
701 	struct inet6_dev *in6_dev;
702 
703 	if (vifi < 0 || vifi >= mrt->maxvif)
704 		return -EADDRNOTAVAIL;
705 
706 	v = &mrt->vif_table[vifi];
707 
708 	if (VIF_EXISTS(mrt, vifi))
709 		call_ip6mr_vif_entry_notifiers(read_pnet(&mrt->net),
710 					       FIB_EVENT_VIF_DEL, v, vifi,
711 					       mrt->id);
712 
713 	write_lock_bh(&mrt_lock);
714 	dev = v->dev;
715 	v->dev = NULL;
716 
717 	if (!dev) {
718 		write_unlock_bh(&mrt_lock);
719 		return -EADDRNOTAVAIL;
720 	}
721 
722 #ifdef CONFIG_IPV6_PIMSM_V2
723 	if (vifi == mrt->mroute_reg_vif_num)
724 		mrt->mroute_reg_vif_num = -1;
725 #endif
726 
727 	if (vifi + 1 == mrt->maxvif) {
728 		int tmp;
729 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
730 			if (VIF_EXISTS(mrt, tmp))
731 				break;
732 		}
733 		mrt->maxvif = tmp + 1;
734 	}
735 
736 	write_unlock_bh(&mrt_lock);
737 
738 	dev_set_allmulti(dev, -1);
739 
740 	in6_dev = __in6_dev_get(dev);
741 	if (in6_dev) {
742 		in6_dev->cnf.mc_forwarding--;
743 		inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
744 					     NETCONFA_MC_FORWARDING,
745 					     dev->ifindex, &in6_dev->cnf);
746 	}
747 
748 	if ((v->flags & MIFF_REGISTER) && !notify)
749 		unregister_netdevice_queue(dev, head);
750 
751 	dev_put(dev);
752 	return 0;
753 }
754 
755 static inline void ip6mr_cache_free_rcu(struct rcu_head *head)
756 {
757 	struct mr_mfc *c = container_of(head, struct mr_mfc, rcu);
758 
759 	kmem_cache_free(mrt_cachep, (struct mfc6_cache *)c);
760 }
761 
762 static inline void ip6mr_cache_free(struct mfc6_cache *c)
763 {
764 	call_rcu(&c->_c.rcu, ip6mr_cache_free_rcu);
765 }
766 
767 /* Destroy an unresolved cache entry, killing queued skbs
768    and reporting error to netlink readers.
769  */
770 
771 static void ip6mr_destroy_unres(struct mr_table *mrt, struct mfc6_cache *c)
772 {
773 	struct net *net = read_pnet(&mrt->net);
774 	struct sk_buff *skb;
775 
776 	atomic_dec(&mrt->cache_resolve_queue_len);
777 
778 	while ((skb = skb_dequeue(&c->_c.mfc_un.unres.unresolved)) != NULL) {
779 		if (ipv6_hdr(skb)->version == 0) {
780 			struct nlmsghdr *nlh = skb_pull(skb,
781 							sizeof(struct ipv6hdr));
782 			nlh->nlmsg_type = NLMSG_ERROR;
783 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
784 			skb_trim(skb, nlh->nlmsg_len);
785 			((struct nlmsgerr *)nlmsg_data(nlh))->error = -ETIMEDOUT;
786 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
787 		} else
788 			kfree_skb(skb);
789 	}
790 
791 	ip6mr_cache_free(c);
792 }
793 
794 
795 /* Timer process for all the unresolved queue. */
796 
797 static void ipmr_do_expire_process(struct mr_table *mrt)
798 {
799 	unsigned long now = jiffies;
800 	unsigned long expires = 10 * HZ;
801 	struct mr_mfc *c, *next;
802 
803 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
804 		if (time_after(c->mfc_un.unres.expires, now)) {
805 			/* not yet... */
806 			unsigned long interval = c->mfc_un.unres.expires - now;
807 			if (interval < expires)
808 				expires = interval;
809 			continue;
810 		}
811 
812 		list_del(&c->list);
813 		mr6_netlink_event(mrt, (struct mfc6_cache *)c, RTM_DELROUTE);
814 		ip6mr_destroy_unres(mrt, (struct mfc6_cache *)c);
815 	}
816 
817 	if (!list_empty(&mrt->mfc_unres_queue))
818 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
819 }
820 
821 static void ipmr_expire_process(struct timer_list *t)
822 {
823 	struct mr_table *mrt = from_timer(mrt, t, ipmr_expire_timer);
824 
825 	if (!spin_trylock(&mfc_unres_lock)) {
826 		mod_timer(&mrt->ipmr_expire_timer, jiffies + 1);
827 		return;
828 	}
829 
830 	if (!list_empty(&mrt->mfc_unres_queue))
831 		ipmr_do_expire_process(mrt);
832 
833 	spin_unlock(&mfc_unres_lock);
834 }
835 
836 /* Fill oifs list. It is called under write locked mrt_lock. */
837 
838 static void ip6mr_update_thresholds(struct mr_table *mrt,
839 				    struct mr_mfc *cache,
840 				    unsigned char *ttls)
841 {
842 	int vifi;
843 
844 	cache->mfc_un.res.minvif = MAXMIFS;
845 	cache->mfc_un.res.maxvif = 0;
846 	memset(cache->mfc_un.res.ttls, 255, MAXMIFS);
847 
848 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
849 		if (VIF_EXISTS(mrt, vifi) &&
850 		    ttls[vifi] && ttls[vifi] < 255) {
851 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
852 			if (cache->mfc_un.res.minvif > vifi)
853 				cache->mfc_un.res.minvif = vifi;
854 			if (cache->mfc_un.res.maxvif <= vifi)
855 				cache->mfc_un.res.maxvif = vifi + 1;
856 		}
857 	}
858 	cache->mfc_un.res.lastuse = jiffies;
859 }
860 
861 static int mif6_add(struct net *net, struct mr_table *mrt,
862 		    struct mif6ctl *vifc, int mrtsock)
863 {
864 	int vifi = vifc->mif6c_mifi;
865 	struct vif_device *v = &mrt->vif_table[vifi];
866 	struct net_device *dev;
867 	struct inet6_dev *in6_dev;
868 	int err;
869 
870 	/* Is vif busy ? */
871 	if (VIF_EXISTS(mrt, vifi))
872 		return -EADDRINUSE;
873 
874 	switch (vifc->mif6c_flags) {
875 #ifdef CONFIG_IPV6_PIMSM_V2
876 	case MIFF_REGISTER:
877 		/*
878 		 * Special Purpose VIF in PIM
879 		 * All the packets will be sent to the daemon
880 		 */
881 		if (mrt->mroute_reg_vif_num >= 0)
882 			return -EADDRINUSE;
883 		dev = ip6mr_reg_vif(net, mrt);
884 		if (!dev)
885 			return -ENOBUFS;
886 		err = dev_set_allmulti(dev, 1);
887 		if (err) {
888 			unregister_netdevice(dev);
889 			dev_put(dev);
890 			return err;
891 		}
892 		break;
893 #endif
894 	case 0:
895 		dev = dev_get_by_index(net, vifc->mif6c_pifi);
896 		if (!dev)
897 			return -EADDRNOTAVAIL;
898 		err = dev_set_allmulti(dev, 1);
899 		if (err) {
900 			dev_put(dev);
901 			return err;
902 		}
903 		break;
904 	default:
905 		return -EINVAL;
906 	}
907 
908 	in6_dev = __in6_dev_get(dev);
909 	if (in6_dev) {
910 		in6_dev->cnf.mc_forwarding++;
911 		inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
912 					     NETCONFA_MC_FORWARDING,
913 					     dev->ifindex, &in6_dev->cnf);
914 	}
915 
916 	/* Fill in the VIF structures */
917 	vif_device_init(v, dev, vifc->vifc_rate_limit, vifc->vifc_threshold,
918 			vifc->mif6c_flags | (!mrtsock ? VIFF_STATIC : 0),
919 			MIFF_REGISTER);
920 
921 	/* And finish update writing critical data */
922 	write_lock_bh(&mrt_lock);
923 	v->dev = dev;
924 #ifdef CONFIG_IPV6_PIMSM_V2
925 	if (v->flags & MIFF_REGISTER)
926 		mrt->mroute_reg_vif_num = vifi;
927 #endif
928 	if (vifi + 1 > mrt->maxvif)
929 		mrt->maxvif = vifi + 1;
930 	write_unlock_bh(&mrt_lock);
931 	call_ip6mr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD,
932 				       v, vifi, mrt->id);
933 	return 0;
934 }
935 
936 static struct mfc6_cache *ip6mr_cache_find(struct mr_table *mrt,
937 					   const struct in6_addr *origin,
938 					   const struct in6_addr *mcastgrp)
939 {
940 	struct mfc6_cache_cmp_arg arg = {
941 		.mf6c_origin = *origin,
942 		.mf6c_mcastgrp = *mcastgrp,
943 	};
944 
945 	return mr_mfc_find(mrt, &arg);
946 }
947 
948 /* Look for a (*,G) entry */
949 static struct mfc6_cache *ip6mr_cache_find_any(struct mr_table *mrt,
950 					       struct in6_addr *mcastgrp,
951 					       mifi_t mifi)
952 {
953 	struct mfc6_cache_cmp_arg arg = {
954 		.mf6c_origin = in6addr_any,
955 		.mf6c_mcastgrp = *mcastgrp,
956 	};
957 
958 	if (ipv6_addr_any(mcastgrp))
959 		return mr_mfc_find_any_parent(mrt, mifi);
960 	return mr_mfc_find_any(mrt, mifi, &arg);
961 }
962 
963 /* Look for a (S,G,iif) entry if parent != -1 */
964 static struct mfc6_cache *
965 ip6mr_cache_find_parent(struct mr_table *mrt,
966 			const struct in6_addr *origin,
967 			const struct in6_addr *mcastgrp,
968 			int parent)
969 {
970 	struct mfc6_cache_cmp_arg arg = {
971 		.mf6c_origin = *origin,
972 		.mf6c_mcastgrp = *mcastgrp,
973 	};
974 
975 	return mr_mfc_find_parent(mrt, &arg, parent);
976 }
977 
978 /* Allocate a multicast cache entry */
979 static struct mfc6_cache *ip6mr_cache_alloc(void)
980 {
981 	struct mfc6_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
982 	if (!c)
983 		return NULL;
984 	c->_c.mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
985 	c->_c.mfc_un.res.minvif = MAXMIFS;
986 	c->_c.free = ip6mr_cache_free_rcu;
987 	refcount_set(&c->_c.mfc_un.res.refcount, 1);
988 	return c;
989 }
990 
991 static struct mfc6_cache *ip6mr_cache_alloc_unres(void)
992 {
993 	struct mfc6_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
994 	if (!c)
995 		return NULL;
996 	skb_queue_head_init(&c->_c.mfc_un.unres.unresolved);
997 	c->_c.mfc_un.unres.expires = jiffies + 10 * HZ;
998 	return c;
999 }
1000 
1001 /*
1002  *	A cache entry has gone into a resolved state from queued
1003  */
1004 
1005 static void ip6mr_cache_resolve(struct net *net, struct mr_table *mrt,
1006 				struct mfc6_cache *uc, struct mfc6_cache *c)
1007 {
1008 	struct sk_buff *skb;
1009 
1010 	/*
1011 	 *	Play the pending entries through our router
1012 	 */
1013 
1014 	while ((skb = __skb_dequeue(&uc->_c.mfc_un.unres.unresolved))) {
1015 		if (ipv6_hdr(skb)->version == 0) {
1016 			struct nlmsghdr *nlh = skb_pull(skb,
1017 							sizeof(struct ipv6hdr));
1018 
1019 			if (mr_fill_mroute(mrt, skb, &c->_c,
1020 					   nlmsg_data(nlh)) > 0) {
1021 				nlh->nlmsg_len = skb_tail_pointer(skb) - (u8 *)nlh;
1022 			} else {
1023 				nlh->nlmsg_type = NLMSG_ERROR;
1024 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
1025 				skb_trim(skb, nlh->nlmsg_len);
1026 				((struct nlmsgerr *)nlmsg_data(nlh))->error = -EMSGSIZE;
1027 			}
1028 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
1029 		} else
1030 			ip6_mr_forward(net, mrt, skb->dev, skb, c);
1031 	}
1032 }
1033 
1034 /*
1035  *	Bounce a cache query up to pim6sd and netlink.
1036  *
1037  *	Called under mrt_lock.
1038  */
1039 
1040 static int ip6mr_cache_report(struct mr_table *mrt, struct sk_buff *pkt,
1041 			      mifi_t mifi, int assert)
1042 {
1043 	struct sock *mroute6_sk;
1044 	struct sk_buff *skb;
1045 	struct mrt6msg *msg;
1046 	int ret;
1047 
1048 #ifdef CONFIG_IPV6_PIMSM_V2
1049 	if (assert == MRT6MSG_WHOLEPKT)
1050 		skb = skb_realloc_headroom(pkt, -skb_network_offset(pkt)
1051 						+sizeof(*msg));
1052 	else
1053 #endif
1054 		skb = alloc_skb(sizeof(struct ipv6hdr) + sizeof(*msg), GFP_ATOMIC);
1055 
1056 	if (!skb)
1057 		return -ENOBUFS;
1058 
1059 	/* I suppose that internal messages
1060 	 * do not require checksums */
1061 
1062 	skb->ip_summed = CHECKSUM_UNNECESSARY;
1063 
1064 #ifdef CONFIG_IPV6_PIMSM_V2
1065 	if (assert == MRT6MSG_WHOLEPKT) {
1066 		/* Ugly, but we have no choice with this interface.
1067 		   Duplicate old header, fix length etc.
1068 		   And all this only to mangle msg->im6_msgtype and
1069 		   to set msg->im6_mbz to "mbz" :-)
1070 		 */
1071 		skb_push(skb, -skb_network_offset(pkt));
1072 
1073 		skb_push(skb, sizeof(*msg));
1074 		skb_reset_transport_header(skb);
1075 		msg = (struct mrt6msg *)skb_transport_header(skb);
1076 		msg->im6_mbz = 0;
1077 		msg->im6_msgtype = MRT6MSG_WHOLEPKT;
1078 		msg->im6_mif = mrt->mroute_reg_vif_num;
1079 		msg->im6_pad = 0;
1080 		msg->im6_src = ipv6_hdr(pkt)->saddr;
1081 		msg->im6_dst = ipv6_hdr(pkt)->daddr;
1082 
1083 		skb->ip_summed = CHECKSUM_UNNECESSARY;
1084 	} else
1085 #endif
1086 	{
1087 	/*
1088 	 *	Copy the IP header
1089 	 */
1090 
1091 	skb_put(skb, sizeof(struct ipv6hdr));
1092 	skb_reset_network_header(skb);
1093 	skb_copy_to_linear_data(skb, ipv6_hdr(pkt), sizeof(struct ipv6hdr));
1094 
1095 	/*
1096 	 *	Add our header
1097 	 */
1098 	skb_put(skb, sizeof(*msg));
1099 	skb_reset_transport_header(skb);
1100 	msg = (struct mrt6msg *)skb_transport_header(skb);
1101 
1102 	msg->im6_mbz = 0;
1103 	msg->im6_msgtype = assert;
1104 	msg->im6_mif = mifi;
1105 	msg->im6_pad = 0;
1106 	msg->im6_src = ipv6_hdr(pkt)->saddr;
1107 	msg->im6_dst = ipv6_hdr(pkt)->daddr;
1108 
1109 	skb_dst_set(skb, dst_clone(skb_dst(pkt)));
1110 	skb->ip_summed = CHECKSUM_UNNECESSARY;
1111 	}
1112 
1113 	rcu_read_lock();
1114 	mroute6_sk = rcu_dereference(mrt->mroute_sk);
1115 	if (!mroute6_sk) {
1116 		rcu_read_unlock();
1117 		kfree_skb(skb);
1118 		return -EINVAL;
1119 	}
1120 
1121 	mrt6msg_netlink_event(mrt, skb);
1122 
1123 	/* Deliver to user space multicast routing algorithms */
1124 	ret = sock_queue_rcv_skb(mroute6_sk, skb);
1125 	rcu_read_unlock();
1126 	if (ret < 0) {
1127 		net_warn_ratelimited("mroute6: pending queue full, dropping entries\n");
1128 		kfree_skb(skb);
1129 	}
1130 
1131 	return ret;
1132 }
1133 
1134 /* Queue a packet for resolution. It gets locked cache entry! */
1135 static int ip6mr_cache_unresolved(struct mr_table *mrt, mifi_t mifi,
1136 				  struct sk_buff *skb, struct net_device *dev)
1137 {
1138 	struct mfc6_cache *c;
1139 	bool found = false;
1140 	int err;
1141 
1142 	spin_lock_bh(&mfc_unres_lock);
1143 	list_for_each_entry(c, &mrt->mfc_unres_queue, _c.list) {
1144 		if (ipv6_addr_equal(&c->mf6c_mcastgrp, &ipv6_hdr(skb)->daddr) &&
1145 		    ipv6_addr_equal(&c->mf6c_origin, &ipv6_hdr(skb)->saddr)) {
1146 			found = true;
1147 			break;
1148 		}
1149 	}
1150 
1151 	if (!found) {
1152 		/*
1153 		 *	Create a new entry if allowable
1154 		 */
1155 
1156 		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
1157 		    (c = ip6mr_cache_alloc_unres()) == NULL) {
1158 			spin_unlock_bh(&mfc_unres_lock);
1159 
1160 			kfree_skb(skb);
1161 			return -ENOBUFS;
1162 		}
1163 
1164 		/* Fill in the new cache entry */
1165 		c->_c.mfc_parent = -1;
1166 		c->mf6c_origin = ipv6_hdr(skb)->saddr;
1167 		c->mf6c_mcastgrp = ipv6_hdr(skb)->daddr;
1168 
1169 		/*
1170 		 *	Reflect first query at pim6sd
1171 		 */
1172 		err = ip6mr_cache_report(mrt, skb, mifi, MRT6MSG_NOCACHE);
1173 		if (err < 0) {
1174 			/* If the report failed throw the cache entry
1175 			   out - Brad Parker
1176 			 */
1177 			spin_unlock_bh(&mfc_unres_lock);
1178 
1179 			ip6mr_cache_free(c);
1180 			kfree_skb(skb);
1181 			return err;
1182 		}
1183 
1184 		atomic_inc(&mrt->cache_resolve_queue_len);
1185 		list_add(&c->_c.list, &mrt->mfc_unres_queue);
1186 		mr6_netlink_event(mrt, c, RTM_NEWROUTE);
1187 
1188 		ipmr_do_expire_process(mrt);
1189 	}
1190 
1191 	/* See if we can append the packet */
1192 	if (c->_c.mfc_un.unres.unresolved.qlen > 3) {
1193 		kfree_skb(skb);
1194 		err = -ENOBUFS;
1195 	} else {
1196 		if (dev) {
1197 			skb->dev = dev;
1198 			skb->skb_iif = dev->ifindex;
1199 		}
1200 		skb_queue_tail(&c->_c.mfc_un.unres.unresolved, skb);
1201 		err = 0;
1202 	}
1203 
1204 	spin_unlock_bh(&mfc_unres_lock);
1205 	return err;
1206 }
1207 
1208 /*
1209  *	MFC6 cache manipulation by user space
1210  */
1211 
1212 static int ip6mr_mfc_delete(struct mr_table *mrt, struct mf6cctl *mfc,
1213 			    int parent)
1214 {
1215 	struct mfc6_cache *c;
1216 
1217 	/* The entries are added/deleted only under RTNL */
1218 	rcu_read_lock();
1219 	c = ip6mr_cache_find_parent(mrt, &mfc->mf6cc_origin.sin6_addr,
1220 				    &mfc->mf6cc_mcastgrp.sin6_addr, parent);
1221 	rcu_read_unlock();
1222 	if (!c)
1223 		return -ENOENT;
1224 	rhltable_remove(&mrt->mfc_hash, &c->_c.mnode, ip6mr_rht_params);
1225 	list_del_rcu(&c->_c.list);
1226 
1227 	call_ip6mr_mfc_entry_notifiers(read_pnet(&mrt->net),
1228 				       FIB_EVENT_ENTRY_DEL, c, mrt->id);
1229 	mr6_netlink_event(mrt, c, RTM_DELROUTE);
1230 	mr_cache_put(&c->_c);
1231 	return 0;
1232 }
1233 
1234 static int ip6mr_device_event(struct notifier_block *this,
1235 			      unsigned long event, void *ptr)
1236 {
1237 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1238 	struct net *net = dev_net(dev);
1239 	struct mr_table *mrt;
1240 	struct vif_device *v;
1241 	int ct;
1242 
1243 	if (event != NETDEV_UNREGISTER)
1244 		return NOTIFY_DONE;
1245 
1246 	ip6mr_for_each_table(mrt, net) {
1247 		v = &mrt->vif_table[0];
1248 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1249 			if (v->dev == dev)
1250 				mif6_delete(mrt, ct, 1, NULL);
1251 		}
1252 	}
1253 
1254 	return NOTIFY_DONE;
1255 }
1256 
1257 static unsigned int ip6mr_seq_read(struct net *net)
1258 {
1259 	ASSERT_RTNL();
1260 
1261 	return net->ipv6.ipmr_seq + ip6mr_rules_seq_read(net);
1262 }
1263 
1264 static int ip6mr_dump(struct net *net, struct notifier_block *nb)
1265 {
1266 	return mr_dump(net, nb, RTNL_FAMILY_IP6MR, ip6mr_rules_dump,
1267 		       ip6mr_mr_table_iter, &mrt_lock);
1268 }
1269 
1270 static struct notifier_block ip6_mr_notifier = {
1271 	.notifier_call = ip6mr_device_event
1272 };
1273 
1274 static const struct fib_notifier_ops ip6mr_notifier_ops_template = {
1275 	.family		= RTNL_FAMILY_IP6MR,
1276 	.fib_seq_read	= ip6mr_seq_read,
1277 	.fib_dump	= ip6mr_dump,
1278 	.owner		= THIS_MODULE,
1279 };
1280 
1281 static int __net_init ip6mr_notifier_init(struct net *net)
1282 {
1283 	struct fib_notifier_ops *ops;
1284 
1285 	net->ipv6.ipmr_seq = 0;
1286 
1287 	ops = fib_notifier_ops_register(&ip6mr_notifier_ops_template, net);
1288 	if (IS_ERR(ops))
1289 		return PTR_ERR(ops);
1290 
1291 	net->ipv6.ip6mr_notifier_ops = ops;
1292 
1293 	return 0;
1294 }
1295 
1296 static void __net_exit ip6mr_notifier_exit(struct net *net)
1297 {
1298 	fib_notifier_ops_unregister(net->ipv6.ip6mr_notifier_ops);
1299 	net->ipv6.ip6mr_notifier_ops = NULL;
1300 }
1301 
1302 /* Setup for IP multicast routing */
1303 static int __net_init ip6mr_net_init(struct net *net)
1304 {
1305 	int err;
1306 
1307 	err = ip6mr_notifier_init(net);
1308 	if (err)
1309 		return err;
1310 
1311 	err = ip6mr_rules_init(net);
1312 	if (err < 0)
1313 		goto ip6mr_rules_fail;
1314 
1315 #ifdef CONFIG_PROC_FS
1316 	err = -ENOMEM;
1317 	if (!proc_create_net("ip6_mr_vif", 0, net->proc_net, &ip6mr_vif_seq_ops,
1318 			sizeof(struct mr_vif_iter)))
1319 		goto proc_vif_fail;
1320 	if (!proc_create_net("ip6_mr_cache", 0, net->proc_net, &ipmr_mfc_seq_ops,
1321 			sizeof(struct mr_mfc_iter)))
1322 		goto proc_cache_fail;
1323 #endif
1324 
1325 	return 0;
1326 
1327 #ifdef CONFIG_PROC_FS
1328 proc_cache_fail:
1329 	remove_proc_entry("ip6_mr_vif", net->proc_net);
1330 proc_vif_fail:
1331 	ip6mr_rules_exit(net);
1332 #endif
1333 ip6mr_rules_fail:
1334 	ip6mr_notifier_exit(net);
1335 	return err;
1336 }
1337 
1338 static void __net_exit ip6mr_net_exit(struct net *net)
1339 {
1340 #ifdef CONFIG_PROC_FS
1341 	remove_proc_entry("ip6_mr_cache", net->proc_net);
1342 	remove_proc_entry("ip6_mr_vif", net->proc_net);
1343 #endif
1344 	ip6mr_rules_exit(net);
1345 	ip6mr_notifier_exit(net);
1346 }
1347 
1348 static struct pernet_operations ip6mr_net_ops = {
1349 	.init = ip6mr_net_init,
1350 	.exit = ip6mr_net_exit,
1351 };
1352 
1353 int __init ip6_mr_init(void)
1354 {
1355 	int err;
1356 
1357 	mrt_cachep = kmem_cache_create("ip6_mrt_cache",
1358 				       sizeof(struct mfc6_cache),
1359 				       0, SLAB_HWCACHE_ALIGN,
1360 				       NULL);
1361 	if (!mrt_cachep)
1362 		return -ENOMEM;
1363 
1364 	err = register_pernet_subsys(&ip6mr_net_ops);
1365 	if (err)
1366 		goto reg_pernet_fail;
1367 
1368 	err = register_netdevice_notifier(&ip6_mr_notifier);
1369 	if (err)
1370 		goto reg_notif_fail;
1371 #ifdef CONFIG_IPV6_PIMSM_V2
1372 	if (inet6_add_protocol(&pim6_protocol, IPPROTO_PIM) < 0) {
1373 		pr_err("%s: can't add PIM protocol\n", __func__);
1374 		err = -EAGAIN;
1375 		goto add_proto_fail;
1376 	}
1377 #endif
1378 	err = rtnl_register_module(THIS_MODULE, RTNL_FAMILY_IP6MR, RTM_GETROUTE,
1379 				   NULL, ip6mr_rtm_dumproute, 0);
1380 	if (err == 0)
1381 		return 0;
1382 
1383 #ifdef CONFIG_IPV6_PIMSM_V2
1384 	inet6_del_protocol(&pim6_protocol, IPPROTO_PIM);
1385 add_proto_fail:
1386 	unregister_netdevice_notifier(&ip6_mr_notifier);
1387 #endif
1388 reg_notif_fail:
1389 	unregister_pernet_subsys(&ip6mr_net_ops);
1390 reg_pernet_fail:
1391 	kmem_cache_destroy(mrt_cachep);
1392 	return err;
1393 }
1394 
1395 void ip6_mr_cleanup(void)
1396 {
1397 	rtnl_unregister(RTNL_FAMILY_IP6MR, RTM_GETROUTE);
1398 #ifdef CONFIG_IPV6_PIMSM_V2
1399 	inet6_del_protocol(&pim6_protocol, IPPROTO_PIM);
1400 #endif
1401 	unregister_netdevice_notifier(&ip6_mr_notifier);
1402 	unregister_pernet_subsys(&ip6mr_net_ops);
1403 	kmem_cache_destroy(mrt_cachep);
1404 }
1405 
1406 static int ip6mr_mfc_add(struct net *net, struct mr_table *mrt,
1407 			 struct mf6cctl *mfc, int mrtsock, int parent)
1408 {
1409 	unsigned char ttls[MAXMIFS];
1410 	struct mfc6_cache *uc, *c;
1411 	struct mr_mfc *_uc;
1412 	bool found;
1413 	int i, err;
1414 
1415 	if (mfc->mf6cc_parent >= MAXMIFS)
1416 		return -ENFILE;
1417 
1418 	memset(ttls, 255, MAXMIFS);
1419 	for (i = 0; i < MAXMIFS; i++) {
1420 		if (IF_ISSET(i, &mfc->mf6cc_ifset))
1421 			ttls[i] = 1;
1422 	}
1423 
1424 	/* The entries are added/deleted only under RTNL */
1425 	rcu_read_lock();
1426 	c = ip6mr_cache_find_parent(mrt, &mfc->mf6cc_origin.sin6_addr,
1427 				    &mfc->mf6cc_mcastgrp.sin6_addr, parent);
1428 	rcu_read_unlock();
1429 	if (c) {
1430 		write_lock_bh(&mrt_lock);
1431 		c->_c.mfc_parent = mfc->mf6cc_parent;
1432 		ip6mr_update_thresholds(mrt, &c->_c, ttls);
1433 		if (!mrtsock)
1434 			c->_c.mfc_flags |= MFC_STATIC;
1435 		write_unlock_bh(&mrt_lock);
1436 		call_ip6mr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE,
1437 					       c, mrt->id);
1438 		mr6_netlink_event(mrt, c, RTM_NEWROUTE);
1439 		return 0;
1440 	}
1441 
1442 	if (!ipv6_addr_any(&mfc->mf6cc_mcastgrp.sin6_addr) &&
1443 	    !ipv6_addr_is_multicast(&mfc->mf6cc_mcastgrp.sin6_addr))
1444 		return -EINVAL;
1445 
1446 	c = ip6mr_cache_alloc();
1447 	if (!c)
1448 		return -ENOMEM;
1449 
1450 	c->mf6c_origin = mfc->mf6cc_origin.sin6_addr;
1451 	c->mf6c_mcastgrp = mfc->mf6cc_mcastgrp.sin6_addr;
1452 	c->_c.mfc_parent = mfc->mf6cc_parent;
1453 	ip6mr_update_thresholds(mrt, &c->_c, ttls);
1454 	if (!mrtsock)
1455 		c->_c.mfc_flags |= MFC_STATIC;
1456 
1457 	err = rhltable_insert_key(&mrt->mfc_hash, &c->cmparg, &c->_c.mnode,
1458 				  ip6mr_rht_params);
1459 	if (err) {
1460 		pr_err("ip6mr: rhtable insert error %d\n", err);
1461 		ip6mr_cache_free(c);
1462 		return err;
1463 	}
1464 	list_add_tail_rcu(&c->_c.list, &mrt->mfc_cache_list);
1465 
1466 	/* Check to see if we resolved a queued list. If so we
1467 	 * need to send on the frames and tidy up.
1468 	 */
1469 	found = false;
1470 	spin_lock_bh(&mfc_unres_lock);
1471 	list_for_each_entry(_uc, &mrt->mfc_unres_queue, list) {
1472 		uc = (struct mfc6_cache *)_uc;
1473 		if (ipv6_addr_equal(&uc->mf6c_origin, &c->mf6c_origin) &&
1474 		    ipv6_addr_equal(&uc->mf6c_mcastgrp, &c->mf6c_mcastgrp)) {
1475 			list_del(&_uc->list);
1476 			atomic_dec(&mrt->cache_resolve_queue_len);
1477 			found = true;
1478 			break;
1479 		}
1480 	}
1481 	if (list_empty(&mrt->mfc_unres_queue))
1482 		del_timer(&mrt->ipmr_expire_timer);
1483 	spin_unlock_bh(&mfc_unres_lock);
1484 
1485 	if (found) {
1486 		ip6mr_cache_resolve(net, mrt, uc, c);
1487 		ip6mr_cache_free(uc);
1488 	}
1489 	call_ip6mr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_ADD,
1490 				       c, mrt->id);
1491 	mr6_netlink_event(mrt, c, RTM_NEWROUTE);
1492 	return 0;
1493 }
1494 
1495 /*
1496  *	Close the multicast socket, and clear the vif tables etc
1497  */
1498 
1499 static void mroute_clean_tables(struct mr_table *mrt, bool all)
1500 {
1501 	struct mr_mfc *c, *tmp;
1502 	LIST_HEAD(list);
1503 	int i;
1504 
1505 	/* Shut down all active vif entries */
1506 	for (i = 0; i < mrt->maxvif; i++) {
1507 		if (!all && (mrt->vif_table[i].flags & VIFF_STATIC))
1508 			continue;
1509 		mif6_delete(mrt, i, 0, &list);
1510 	}
1511 	unregister_netdevice_many(&list);
1512 
1513 	/* Wipe the cache */
1514 	list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
1515 		if (!all && (c->mfc_flags & MFC_STATIC))
1516 			continue;
1517 		rhltable_remove(&mrt->mfc_hash, &c->mnode, ip6mr_rht_params);
1518 		list_del_rcu(&c->list);
1519 		call_ip6mr_mfc_entry_notifiers(read_pnet(&mrt->net),
1520 					       FIB_EVENT_ENTRY_DEL,
1521 					       (struct mfc6_cache *)c, mrt->id);
1522 		mr6_netlink_event(mrt, (struct mfc6_cache *)c, RTM_DELROUTE);
1523 		mr_cache_put(c);
1524 	}
1525 
1526 	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1527 		spin_lock_bh(&mfc_unres_lock);
1528 		list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
1529 			list_del(&c->list);
1530 			mr6_netlink_event(mrt, (struct mfc6_cache *)c,
1531 					  RTM_DELROUTE);
1532 			ip6mr_destroy_unres(mrt, (struct mfc6_cache *)c);
1533 		}
1534 		spin_unlock_bh(&mfc_unres_lock);
1535 	}
1536 }
1537 
1538 static int ip6mr_sk_init(struct mr_table *mrt, struct sock *sk)
1539 {
1540 	int err = 0;
1541 	struct net *net = sock_net(sk);
1542 
1543 	rtnl_lock();
1544 	write_lock_bh(&mrt_lock);
1545 	if (rtnl_dereference(mrt->mroute_sk)) {
1546 		err = -EADDRINUSE;
1547 	} else {
1548 		rcu_assign_pointer(mrt->mroute_sk, sk);
1549 		sock_set_flag(sk, SOCK_RCU_FREE);
1550 		net->ipv6.devconf_all->mc_forwarding++;
1551 	}
1552 	write_unlock_bh(&mrt_lock);
1553 
1554 	if (!err)
1555 		inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
1556 					     NETCONFA_MC_FORWARDING,
1557 					     NETCONFA_IFINDEX_ALL,
1558 					     net->ipv6.devconf_all);
1559 	rtnl_unlock();
1560 
1561 	return err;
1562 }
1563 
1564 int ip6mr_sk_done(struct sock *sk)
1565 {
1566 	int err = -EACCES;
1567 	struct net *net = sock_net(sk);
1568 	struct mr_table *mrt;
1569 
1570 	if (sk->sk_type != SOCK_RAW ||
1571 	    inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
1572 		return err;
1573 
1574 	rtnl_lock();
1575 	ip6mr_for_each_table(mrt, net) {
1576 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1577 			write_lock_bh(&mrt_lock);
1578 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1579 			/* Note that mroute_sk had SOCK_RCU_FREE set,
1580 			 * so the RCU grace period before sk freeing
1581 			 * is guaranteed by sk_destruct()
1582 			 */
1583 			net->ipv6.devconf_all->mc_forwarding--;
1584 			write_unlock_bh(&mrt_lock);
1585 			inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
1586 						     NETCONFA_MC_FORWARDING,
1587 						     NETCONFA_IFINDEX_ALL,
1588 						     net->ipv6.devconf_all);
1589 
1590 			mroute_clean_tables(mrt, false);
1591 			err = 0;
1592 			break;
1593 		}
1594 	}
1595 	rtnl_unlock();
1596 
1597 	return err;
1598 }
1599 
1600 bool mroute6_is_socket(struct net *net, struct sk_buff *skb)
1601 {
1602 	struct mr_table *mrt;
1603 	struct flowi6 fl6 = {
1604 		.flowi6_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
1605 		.flowi6_oif	= skb->dev->ifindex,
1606 		.flowi6_mark	= skb->mark,
1607 	};
1608 
1609 	if (ip6mr_fib_lookup(net, &fl6, &mrt) < 0)
1610 		return NULL;
1611 
1612 	return rcu_access_pointer(mrt->mroute_sk);
1613 }
1614 EXPORT_SYMBOL(mroute6_is_socket);
1615 
1616 /*
1617  *	Socket options and virtual interface manipulation. The whole
1618  *	virtual interface system is a complete heap, but unfortunately
1619  *	that's how BSD mrouted happens to think. Maybe one day with a proper
1620  *	MOSPF/PIM router set up we can clean this up.
1621  */
1622 
1623 int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen)
1624 {
1625 	int ret, parent = 0;
1626 	struct mif6ctl vif;
1627 	struct mf6cctl mfc;
1628 	mifi_t mifi;
1629 	struct net *net = sock_net(sk);
1630 	struct mr_table *mrt;
1631 
1632 	if (sk->sk_type != SOCK_RAW ||
1633 	    inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
1634 		return -EOPNOTSUPP;
1635 
1636 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
1637 	if (!mrt)
1638 		return -ENOENT;
1639 
1640 	if (optname != MRT6_INIT) {
1641 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1642 		    !ns_capable(net->user_ns, CAP_NET_ADMIN))
1643 			return -EACCES;
1644 	}
1645 
1646 	switch (optname) {
1647 	case MRT6_INIT:
1648 		if (optlen < sizeof(int))
1649 			return -EINVAL;
1650 
1651 		return ip6mr_sk_init(mrt, sk);
1652 
1653 	case MRT6_DONE:
1654 		return ip6mr_sk_done(sk);
1655 
1656 	case MRT6_ADD_MIF:
1657 		if (optlen < sizeof(vif))
1658 			return -EINVAL;
1659 		if (copy_from_user(&vif, optval, sizeof(vif)))
1660 			return -EFAULT;
1661 		if (vif.mif6c_mifi >= MAXMIFS)
1662 			return -ENFILE;
1663 		rtnl_lock();
1664 		ret = mif6_add(net, mrt, &vif,
1665 			       sk == rtnl_dereference(mrt->mroute_sk));
1666 		rtnl_unlock();
1667 		return ret;
1668 
1669 	case MRT6_DEL_MIF:
1670 		if (optlen < sizeof(mifi_t))
1671 			return -EINVAL;
1672 		if (copy_from_user(&mifi, optval, sizeof(mifi_t)))
1673 			return -EFAULT;
1674 		rtnl_lock();
1675 		ret = mif6_delete(mrt, mifi, 0, NULL);
1676 		rtnl_unlock();
1677 		return ret;
1678 
1679 	/*
1680 	 *	Manipulate the forwarding caches. These live
1681 	 *	in a sort of kernel/user symbiosis.
1682 	 */
1683 	case MRT6_ADD_MFC:
1684 	case MRT6_DEL_MFC:
1685 		parent = -1;
1686 		/* fall through */
1687 	case MRT6_ADD_MFC_PROXY:
1688 	case MRT6_DEL_MFC_PROXY:
1689 		if (optlen < sizeof(mfc))
1690 			return -EINVAL;
1691 		if (copy_from_user(&mfc, optval, sizeof(mfc)))
1692 			return -EFAULT;
1693 		if (parent == 0)
1694 			parent = mfc.mf6cc_parent;
1695 		rtnl_lock();
1696 		if (optname == MRT6_DEL_MFC || optname == MRT6_DEL_MFC_PROXY)
1697 			ret = ip6mr_mfc_delete(mrt, &mfc, parent);
1698 		else
1699 			ret = ip6mr_mfc_add(net, mrt, &mfc,
1700 					    sk ==
1701 					    rtnl_dereference(mrt->mroute_sk),
1702 					    parent);
1703 		rtnl_unlock();
1704 		return ret;
1705 
1706 	/*
1707 	 *	Control PIM assert (to activate pim will activate assert)
1708 	 */
1709 	case MRT6_ASSERT:
1710 	{
1711 		int v;
1712 
1713 		if (optlen != sizeof(v))
1714 			return -EINVAL;
1715 		if (get_user(v, (int __user *)optval))
1716 			return -EFAULT;
1717 		mrt->mroute_do_assert = v;
1718 		return 0;
1719 	}
1720 
1721 #ifdef CONFIG_IPV6_PIMSM_V2
1722 	case MRT6_PIM:
1723 	{
1724 		int v;
1725 
1726 		if (optlen != sizeof(v))
1727 			return -EINVAL;
1728 		if (get_user(v, (int __user *)optval))
1729 			return -EFAULT;
1730 		v = !!v;
1731 		rtnl_lock();
1732 		ret = 0;
1733 		if (v != mrt->mroute_do_pim) {
1734 			mrt->mroute_do_pim = v;
1735 			mrt->mroute_do_assert = v;
1736 		}
1737 		rtnl_unlock();
1738 		return ret;
1739 	}
1740 
1741 #endif
1742 #ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
1743 	case MRT6_TABLE:
1744 	{
1745 		u32 v;
1746 
1747 		if (optlen != sizeof(u32))
1748 			return -EINVAL;
1749 		if (get_user(v, (u32 __user *)optval))
1750 			return -EFAULT;
1751 		/* "pim6reg%u" should not exceed 16 bytes (IFNAMSIZ) */
1752 		if (v != RT_TABLE_DEFAULT && v >= 100000000)
1753 			return -EINVAL;
1754 		if (sk == rcu_access_pointer(mrt->mroute_sk))
1755 			return -EBUSY;
1756 
1757 		rtnl_lock();
1758 		ret = 0;
1759 		mrt = ip6mr_new_table(net, v);
1760 		if (IS_ERR(mrt))
1761 			ret = PTR_ERR(mrt);
1762 		else
1763 			raw6_sk(sk)->ip6mr_table = v;
1764 		rtnl_unlock();
1765 		return ret;
1766 	}
1767 #endif
1768 	/*
1769 	 *	Spurious command, or MRT6_VERSION which you cannot
1770 	 *	set.
1771 	 */
1772 	default:
1773 		return -ENOPROTOOPT;
1774 	}
1775 }
1776 
1777 /*
1778  *	Getsock opt support for the multicast routing system.
1779  */
1780 
1781 int ip6_mroute_getsockopt(struct sock *sk, int optname, char __user *optval,
1782 			  int __user *optlen)
1783 {
1784 	int olr;
1785 	int val;
1786 	struct net *net = sock_net(sk);
1787 	struct mr_table *mrt;
1788 
1789 	if (sk->sk_type != SOCK_RAW ||
1790 	    inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
1791 		return -EOPNOTSUPP;
1792 
1793 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
1794 	if (!mrt)
1795 		return -ENOENT;
1796 
1797 	switch (optname) {
1798 	case MRT6_VERSION:
1799 		val = 0x0305;
1800 		break;
1801 #ifdef CONFIG_IPV6_PIMSM_V2
1802 	case MRT6_PIM:
1803 		val = mrt->mroute_do_pim;
1804 		break;
1805 #endif
1806 	case MRT6_ASSERT:
1807 		val = mrt->mroute_do_assert;
1808 		break;
1809 	default:
1810 		return -ENOPROTOOPT;
1811 	}
1812 
1813 	if (get_user(olr, optlen))
1814 		return -EFAULT;
1815 
1816 	olr = min_t(int, olr, sizeof(int));
1817 	if (olr < 0)
1818 		return -EINVAL;
1819 
1820 	if (put_user(olr, optlen))
1821 		return -EFAULT;
1822 	if (copy_to_user(optval, &val, olr))
1823 		return -EFAULT;
1824 	return 0;
1825 }
1826 
1827 /*
1828  *	The IP multicast ioctl support routines.
1829  */
1830 
1831 int ip6mr_ioctl(struct sock *sk, int cmd, void __user *arg)
1832 {
1833 	struct sioc_sg_req6 sr;
1834 	struct sioc_mif_req6 vr;
1835 	struct vif_device *vif;
1836 	struct mfc6_cache *c;
1837 	struct net *net = sock_net(sk);
1838 	struct mr_table *mrt;
1839 
1840 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
1841 	if (!mrt)
1842 		return -ENOENT;
1843 
1844 	switch (cmd) {
1845 	case SIOCGETMIFCNT_IN6:
1846 		if (copy_from_user(&vr, arg, sizeof(vr)))
1847 			return -EFAULT;
1848 		if (vr.mifi >= mrt->maxvif)
1849 			return -EINVAL;
1850 		vr.mifi = array_index_nospec(vr.mifi, mrt->maxvif);
1851 		read_lock(&mrt_lock);
1852 		vif = &mrt->vif_table[vr.mifi];
1853 		if (VIF_EXISTS(mrt, vr.mifi)) {
1854 			vr.icount = vif->pkt_in;
1855 			vr.ocount = vif->pkt_out;
1856 			vr.ibytes = vif->bytes_in;
1857 			vr.obytes = vif->bytes_out;
1858 			read_unlock(&mrt_lock);
1859 
1860 			if (copy_to_user(arg, &vr, sizeof(vr)))
1861 				return -EFAULT;
1862 			return 0;
1863 		}
1864 		read_unlock(&mrt_lock);
1865 		return -EADDRNOTAVAIL;
1866 	case SIOCGETSGCNT_IN6:
1867 		if (copy_from_user(&sr, arg, sizeof(sr)))
1868 			return -EFAULT;
1869 
1870 		rcu_read_lock();
1871 		c = ip6mr_cache_find(mrt, &sr.src.sin6_addr, &sr.grp.sin6_addr);
1872 		if (c) {
1873 			sr.pktcnt = c->_c.mfc_un.res.pkt;
1874 			sr.bytecnt = c->_c.mfc_un.res.bytes;
1875 			sr.wrong_if = c->_c.mfc_un.res.wrong_if;
1876 			rcu_read_unlock();
1877 
1878 			if (copy_to_user(arg, &sr, sizeof(sr)))
1879 				return -EFAULT;
1880 			return 0;
1881 		}
1882 		rcu_read_unlock();
1883 		return -EADDRNOTAVAIL;
1884 	default:
1885 		return -ENOIOCTLCMD;
1886 	}
1887 }
1888 
1889 #ifdef CONFIG_COMPAT
1890 struct compat_sioc_sg_req6 {
1891 	struct sockaddr_in6 src;
1892 	struct sockaddr_in6 grp;
1893 	compat_ulong_t pktcnt;
1894 	compat_ulong_t bytecnt;
1895 	compat_ulong_t wrong_if;
1896 };
1897 
1898 struct compat_sioc_mif_req6 {
1899 	mifi_t	mifi;
1900 	compat_ulong_t icount;
1901 	compat_ulong_t ocount;
1902 	compat_ulong_t ibytes;
1903 	compat_ulong_t obytes;
1904 };
1905 
1906 int ip6mr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1907 {
1908 	struct compat_sioc_sg_req6 sr;
1909 	struct compat_sioc_mif_req6 vr;
1910 	struct vif_device *vif;
1911 	struct mfc6_cache *c;
1912 	struct net *net = sock_net(sk);
1913 	struct mr_table *mrt;
1914 
1915 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
1916 	if (!mrt)
1917 		return -ENOENT;
1918 
1919 	switch (cmd) {
1920 	case SIOCGETMIFCNT_IN6:
1921 		if (copy_from_user(&vr, arg, sizeof(vr)))
1922 			return -EFAULT;
1923 		if (vr.mifi >= mrt->maxvif)
1924 			return -EINVAL;
1925 		vr.mifi = array_index_nospec(vr.mifi, mrt->maxvif);
1926 		read_lock(&mrt_lock);
1927 		vif = &mrt->vif_table[vr.mifi];
1928 		if (VIF_EXISTS(mrt, vr.mifi)) {
1929 			vr.icount = vif->pkt_in;
1930 			vr.ocount = vif->pkt_out;
1931 			vr.ibytes = vif->bytes_in;
1932 			vr.obytes = vif->bytes_out;
1933 			read_unlock(&mrt_lock);
1934 
1935 			if (copy_to_user(arg, &vr, sizeof(vr)))
1936 				return -EFAULT;
1937 			return 0;
1938 		}
1939 		read_unlock(&mrt_lock);
1940 		return -EADDRNOTAVAIL;
1941 	case SIOCGETSGCNT_IN6:
1942 		if (copy_from_user(&sr, arg, sizeof(sr)))
1943 			return -EFAULT;
1944 
1945 		rcu_read_lock();
1946 		c = ip6mr_cache_find(mrt, &sr.src.sin6_addr, &sr.grp.sin6_addr);
1947 		if (c) {
1948 			sr.pktcnt = c->_c.mfc_un.res.pkt;
1949 			sr.bytecnt = c->_c.mfc_un.res.bytes;
1950 			sr.wrong_if = c->_c.mfc_un.res.wrong_if;
1951 			rcu_read_unlock();
1952 
1953 			if (copy_to_user(arg, &sr, sizeof(sr)))
1954 				return -EFAULT;
1955 			return 0;
1956 		}
1957 		rcu_read_unlock();
1958 		return -EADDRNOTAVAIL;
1959 	default:
1960 		return -ENOIOCTLCMD;
1961 	}
1962 }
1963 #endif
1964 
1965 static inline int ip6mr_forward2_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
1966 {
1967 	__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
1968 			IPSTATS_MIB_OUTFORWDATAGRAMS);
1969 	__IP6_ADD_STATS(net, ip6_dst_idev(skb_dst(skb)),
1970 			IPSTATS_MIB_OUTOCTETS, skb->len);
1971 	return dst_output(net, sk, skb);
1972 }
1973 
1974 /*
1975  *	Processing handlers for ip6mr_forward
1976  */
1977 
1978 static int ip6mr_forward2(struct net *net, struct mr_table *mrt,
1979 			  struct sk_buff *skb, int vifi)
1980 {
1981 	struct ipv6hdr *ipv6h;
1982 	struct vif_device *vif = &mrt->vif_table[vifi];
1983 	struct net_device *dev;
1984 	struct dst_entry *dst;
1985 	struct flowi6 fl6;
1986 
1987 	if (!vif->dev)
1988 		goto out_free;
1989 
1990 #ifdef CONFIG_IPV6_PIMSM_V2
1991 	if (vif->flags & MIFF_REGISTER) {
1992 		vif->pkt_out++;
1993 		vif->bytes_out += skb->len;
1994 		vif->dev->stats.tx_bytes += skb->len;
1995 		vif->dev->stats.tx_packets++;
1996 		ip6mr_cache_report(mrt, skb, vifi, MRT6MSG_WHOLEPKT);
1997 		goto out_free;
1998 	}
1999 #endif
2000 
2001 	ipv6h = ipv6_hdr(skb);
2002 
2003 	fl6 = (struct flowi6) {
2004 		.flowi6_oif = vif->link,
2005 		.daddr = ipv6h->daddr,
2006 	};
2007 
2008 	dst = ip6_route_output(net, NULL, &fl6);
2009 	if (dst->error) {
2010 		dst_release(dst);
2011 		goto out_free;
2012 	}
2013 
2014 	skb_dst_drop(skb);
2015 	skb_dst_set(skb, dst);
2016 
2017 	/*
2018 	 * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
2019 	 * not only before forwarding, but after forwarding on all output
2020 	 * interfaces. It is clear, if mrouter runs a multicasting
2021 	 * program, it should receive packets not depending to what interface
2022 	 * program is joined.
2023 	 * If we will not make it, the program will have to join on all
2024 	 * interfaces. On the other hand, multihoming host (or router, but
2025 	 * not mrouter) cannot join to more than one interface - it will
2026 	 * result in receiving multiple packets.
2027 	 */
2028 	dev = vif->dev;
2029 	skb->dev = dev;
2030 	vif->pkt_out++;
2031 	vif->bytes_out += skb->len;
2032 
2033 	/* We are about to write */
2034 	/* XXX: extension headers? */
2035 	if (skb_cow(skb, sizeof(*ipv6h) + LL_RESERVED_SPACE(dev)))
2036 		goto out_free;
2037 
2038 	ipv6h = ipv6_hdr(skb);
2039 	ipv6h->hop_limit--;
2040 
2041 	IP6CB(skb)->flags |= IP6SKB_FORWARDED;
2042 
2043 	return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD,
2044 		       net, NULL, skb, skb->dev, dev,
2045 		       ip6mr_forward2_finish);
2046 
2047 out_free:
2048 	kfree_skb(skb);
2049 	return 0;
2050 }
2051 
2052 static int ip6mr_find_vif(struct mr_table *mrt, struct net_device *dev)
2053 {
2054 	int ct;
2055 
2056 	for (ct = mrt->maxvif - 1; ct >= 0; ct--) {
2057 		if (mrt->vif_table[ct].dev == dev)
2058 			break;
2059 	}
2060 	return ct;
2061 }
2062 
2063 static void ip6_mr_forward(struct net *net, struct mr_table *mrt,
2064 			   struct net_device *dev, struct sk_buff *skb,
2065 			   struct mfc6_cache *c)
2066 {
2067 	int psend = -1;
2068 	int vif, ct;
2069 	int true_vifi = ip6mr_find_vif(mrt, dev);
2070 
2071 	vif = c->_c.mfc_parent;
2072 	c->_c.mfc_un.res.pkt++;
2073 	c->_c.mfc_un.res.bytes += skb->len;
2074 	c->_c.mfc_un.res.lastuse = jiffies;
2075 
2076 	if (ipv6_addr_any(&c->mf6c_origin) && true_vifi >= 0) {
2077 		struct mfc6_cache *cache_proxy;
2078 
2079 		/* For an (*,G) entry, we only check that the incoming
2080 		 * interface is part of the static tree.
2081 		 */
2082 		rcu_read_lock();
2083 		cache_proxy = mr_mfc_find_any_parent(mrt, vif);
2084 		if (cache_proxy &&
2085 		    cache_proxy->_c.mfc_un.res.ttls[true_vifi] < 255) {
2086 			rcu_read_unlock();
2087 			goto forward;
2088 		}
2089 		rcu_read_unlock();
2090 	}
2091 
2092 	/*
2093 	 * Wrong interface: drop packet and (maybe) send PIM assert.
2094 	 */
2095 	if (mrt->vif_table[vif].dev != dev) {
2096 		c->_c.mfc_un.res.wrong_if++;
2097 
2098 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
2099 		    /* pimsm uses asserts, when switching from RPT to SPT,
2100 		       so that we cannot check that packet arrived on an oif.
2101 		       It is bad, but otherwise we would need to move pretty
2102 		       large chunk of pimd to kernel. Ough... --ANK
2103 		     */
2104 		    (mrt->mroute_do_pim ||
2105 		     c->_c.mfc_un.res.ttls[true_vifi] < 255) &&
2106 		    time_after(jiffies,
2107 			       c->_c.mfc_un.res.last_assert +
2108 			       MFC_ASSERT_THRESH)) {
2109 			c->_c.mfc_un.res.last_assert = jiffies;
2110 			ip6mr_cache_report(mrt, skb, true_vifi, MRT6MSG_WRONGMIF);
2111 		}
2112 		goto dont_forward;
2113 	}
2114 
2115 forward:
2116 	mrt->vif_table[vif].pkt_in++;
2117 	mrt->vif_table[vif].bytes_in += skb->len;
2118 
2119 	/*
2120 	 *	Forward the frame
2121 	 */
2122 	if (ipv6_addr_any(&c->mf6c_origin) &&
2123 	    ipv6_addr_any(&c->mf6c_mcastgrp)) {
2124 		if (true_vifi >= 0 &&
2125 		    true_vifi != c->_c.mfc_parent &&
2126 		    ipv6_hdr(skb)->hop_limit >
2127 				c->_c.mfc_un.res.ttls[c->_c.mfc_parent]) {
2128 			/* It's an (*,*) entry and the packet is not coming from
2129 			 * the upstream: forward the packet to the upstream
2130 			 * only.
2131 			 */
2132 			psend = c->_c.mfc_parent;
2133 			goto last_forward;
2134 		}
2135 		goto dont_forward;
2136 	}
2137 	for (ct = c->_c.mfc_un.res.maxvif - 1;
2138 	     ct >= c->_c.mfc_un.res.minvif; ct--) {
2139 		/* For (*,G) entry, don't forward to the incoming interface */
2140 		if ((!ipv6_addr_any(&c->mf6c_origin) || ct != true_vifi) &&
2141 		    ipv6_hdr(skb)->hop_limit > c->_c.mfc_un.res.ttls[ct]) {
2142 			if (psend != -1) {
2143 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2144 				if (skb2)
2145 					ip6mr_forward2(net, mrt, skb2, psend);
2146 			}
2147 			psend = ct;
2148 		}
2149 	}
2150 last_forward:
2151 	if (psend != -1) {
2152 		ip6mr_forward2(net, mrt, skb, psend);
2153 		return;
2154 	}
2155 
2156 dont_forward:
2157 	kfree_skb(skb);
2158 }
2159 
2160 
2161 /*
2162  *	Multicast packets for forwarding arrive here
2163  */
2164 
2165 int ip6_mr_input(struct sk_buff *skb)
2166 {
2167 	struct mfc6_cache *cache;
2168 	struct net *net = dev_net(skb->dev);
2169 	struct mr_table *mrt;
2170 	struct flowi6 fl6 = {
2171 		.flowi6_iif	= skb->dev->ifindex,
2172 		.flowi6_mark	= skb->mark,
2173 	};
2174 	int err;
2175 	struct net_device *dev;
2176 
2177 	/* skb->dev passed in is the master dev for vrfs.
2178 	 * Get the proper interface that does have a vif associated with it.
2179 	 */
2180 	dev = skb->dev;
2181 	if (netif_is_l3_master(skb->dev)) {
2182 		dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
2183 		if (!dev) {
2184 			kfree_skb(skb);
2185 			return -ENODEV;
2186 		}
2187 	}
2188 
2189 	err = ip6mr_fib_lookup(net, &fl6, &mrt);
2190 	if (err < 0) {
2191 		kfree_skb(skb);
2192 		return err;
2193 	}
2194 
2195 	read_lock(&mrt_lock);
2196 	cache = ip6mr_cache_find(mrt,
2197 				 &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr);
2198 	if (!cache) {
2199 		int vif = ip6mr_find_vif(mrt, dev);
2200 
2201 		if (vif >= 0)
2202 			cache = ip6mr_cache_find_any(mrt,
2203 						     &ipv6_hdr(skb)->daddr,
2204 						     vif);
2205 	}
2206 
2207 	/*
2208 	 *	No usable cache entry
2209 	 */
2210 	if (!cache) {
2211 		int vif;
2212 
2213 		vif = ip6mr_find_vif(mrt, dev);
2214 		if (vif >= 0) {
2215 			int err = ip6mr_cache_unresolved(mrt, vif, skb, dev);
2216 			read_unlock(&mrt_lock);
2217 
2218 			return err;
2219 		}
2220 		read_unlock(&mrt_lock);
2221 		kfree_skb(skb);
2222 		return -ENODEV;
2223 	}
2224 
2225 	ip6_mr_forward(net, mrt, dev, skb, cache);
2226 
2227 	read_unlock(&mrt_lock);
2228 
2229 	return 0;
2230 }
2231 
2232 int ip6mr_get_route(struct net *net, struct sk_buff *skb, struct rtmsg *rtm,
2233 		    u32 portid)
2234 {
2235 	int err;
2236 	struct mr_table *mrt;
2237 	struct mfc6_cache *cache;
2238 	struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
2239 
2240 	mrt = ip6mr_get_table(net, RT6_TABLE_DFLT);
2241 	if (!mrt)
2242 		return -ENOENT;
2243 
2244 	read_lock(&mrt_lock);
2245 	cache = ip6mr_cache_find(mrt, &rt->rt6i_src.addr, &rt->rt6i_dst.addr);
2246 	if (!cache && skb->dev) {
2247 		int vif = ip6mr_find_vif(mrt, skb->dev);
2248 
2249 		if (vif >= 0)
2250 			cache = ip6mr_cache_find_any(mrt, &rt->rt6i_dst.addr,
2251 						     vif);
2252 	}
2253 
2254 	if (!cache) {
2255 		struct sk_buff *skb2;
2256 		struct ipv6hdr *iph;
2257 		struct net_device *dev;
2258 		int vif;
2259 
2260 		dev = skb->dev;
2261 		if (!dev || (vif = ip6mr_find_vif(mrt, dev)) < 0) {
2262 			read_unlock(&mrt_lock);
2263 			return -ENODEV;
2264 		}
2265 
2266 		/* really correct? */
2267 		skb2 = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
2268 		if (!skb2) {
2269 			read_unlock(&mrt_lock);
2270 			return -ENOMEM;
2271 		}
2272 
2273 		NETLINK_CB(skb2).portid = portid;
2274 		skb_reset_transport_header(skb2);
2275 
2276 		skb_put(skb2, sizeof(struct ipv6hdr));
2277 		skb_reset_network_header(skb2);
2278 
2279 		iph = ipv6_hdr(skb2);
2280 		iph->version = 0;
2281 		iph->priority = 0;
2282 		iph->flow_lbl[0] = 0;
2283 		iph->flow_lbl[1] = 0;
2284 		iph->flow_lbl[2] = 0;
2285 		iph->payload_len = 0;
2286 		iph->nexthdr = IPPROTO_NONE;
2287 		iph->hop_limit = 0;
2288 		iph->saddr = rt->rt6i_src.addr;
2289 		iph->daddr = rt->rt6i_dst.addr;
2290 
2291 		err = ip6mr_cache_unresolved(mrt, vif, skb2, dev);
2292 		read_unlock(&mrt_lock);
2293 
2294 		return err;
2295 	}
2296 
2297 	err = mr_fill_mroute(mrt, skb, &cache->_c, rtm);
2298 	read_unlock(&mrt_lock);
2299 	return err;
2300 }
2301 
2302 static int ip6mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2303 			     u32 portid, u32 seq, struct mfc6_cache *c, int cmd,
2304 			     int flags)
2305 {
2306 	struct nlmsghdr *nlh;
2307 	struct rtmsg *rtm;
2308 	int err;
2309 
2310 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2311 	if (!nlh)
2312 		return -EMSGSIZE;
2313 
2314 	rtm = nlmsg_data(nlh);
2315 	rtm->rtm_family   = RTNL_FAMILY_IP6MR;
2316 	rtm->rtm_dst_len  = 128;
2317 	rtm->rtm_src_len  = 128;
2318 	rtm->rtm_tos      = 0;
2319 	rtm->rtm_table    = mrt->id;
2320 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2321 		goto nla_put_failure;
2322 	rtm->rtm_type = RTN_MULTICAST;
2323 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2324 	if (c->_c.mfc_flags & MFC_STATIC)
2325 		rtm->rtm_protocol = RTPROT_STATIC;
2326 	else
2327 		rtm->rtm_protocol = RTPROT_MROUTED;
2328 	rtm->rtm_flags    = 0;
2329 
2330 	if (nla_put_in6_addr(skb, RTA_SRC, &c->mf6c_origin) ||
2331 	    nla_put_in6_addr(skb, RTA_DST, &c->mf6c_mcastgrp))
2332 		goto nla_put_failure;
2333 	err = mr_fill_mroute(mrt, skb, &c->_c, rtm);
2334 	/* do not break the dump if cache is unresolved */
2335 	if (err < 0 && err != -ENOENT)
2336 		goto nla_put_failure;
2337 
2338 	nlmsg_end(skb, nlh);
2339 	return 0;
2340 
2341 nla_put_failure:
2342 	nlmsg_cancel(skb, nlh);
2343 	return -EMSGSIZE;
2344 }
2345 
2346 static int _ip6mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2347 			      u32 portid, u32 seq, struct mr_mfc *c,
2348 			      int cmd, int flags)
2349 {
2350 	return ip6mr_fill_mroute(mrt, skb, portid, seq, (struct mfc6_cache *)c,
2351 				 cmd, flags);
2352 }
2353 
2354 static int mr6_msgsize(bool unresolved, int maxvif)
2355 {
2356 	size_t len =
2357 		NLMSG_ALIGN(sizeof(struct rtmsg))
2358 		+ nla_total_size(4)	/* RTA_TABLE */
2359 		+ nla_total_size(sizeof(struct in6_addr))	/* RTA_SRC */
2360 		+ nla_total_size(sizeof(struct in6_addr))	/* RTA_DST */
2361 		;
2362 
2363 	if (!unresolved)
2364 		len = len
2365 		      + nla_total_size(4)	/* RTA_IIF */
2366 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2367 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2368 						/* RTA_MFC_STATS */
2369 		      + nla_total_size_64bit(sizeof(struct rta_mfc_stats))
2370 		;
2371 
2372 	return len;
2373 }
2374 
2375 static void mr6_netlink_event(struct mr_table *mrt, struct mfc6_cache *mfc,
2376 			      int cmd)
2377 {
2378 	struct net *net = read_pnet(&mrt->net);
2379 	struct sk_buff *skb;
2380 	int err = -ENOBUFS;
2381 
2382 	skb = nlmsg_new(mr6_msgsize(mfc->_c.mfc_parent >= MAXMIFS, mrt->maxvif),
2383 			GFP_ATOMIC);
2384 	if (!skb)
2385 		goto errout;
2386 
2387 	err = ip6mr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2388 	if (err < 0)
2389 		goto errout;
2390 
2391 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_MROUTE, NULL, GFP_ATOMIC);
2392 	return;
2393 
2394 errout:
2395 	kfree_skb(skb);
2396 	if (err < 0)
2397 		rtnl_set_sk_err(net, RTNLGRP_IPV6_MROUTE, err);
2398 }
2399 
2400 static size_t mrt6msg_netlink_msgsize(size_t payloadlen)
2401 {
2402 	size_t len =
2403 		NLMSG_ALIGN(sizeof(struct rtgenmsg))
2404 		+ nla_total_size(1)	/* IP6MRA_CREPORT_MSGTYPE */
2405 		+ nla_total_size(4)	/* IP6MRA_CREPORT_MIF_ID */
2406 					/* IP6MRA_CREPORT_SRC_ADDR */
2407 		+ nla_total_size(sizeof(struct in6_addr))
2408 					/* IP6MRA_CREPORT_DST_ADDR */
2409 		+ nla_total_size(sizeof(struct in6_addr))
2410 					/* IP6MRA_CREPORT_PKT */
2411 		+ nla_total_size(payloadlen)
2412 		;
2413 
2414 	return len;
2415 }
2416 
2417 static void mrt6msg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt)
2418 {
2419 	struct net *net = read_pnet(&mrt->net);
2420 	struct nlmsghdr *nlh;
2421 	struct rtgenmsg *rtgenm;
2422 	struct mrt6msg *msg;
2423 	struct sk_buff *skb;
2424 	struct nlattr *nla;
2425 	int payloadlen;
2426 
2427 	payloadlen = pkt->len - sizeof(struct mrt6msg);
2428 	msg = (struct mrt6msg *)skb_transport_header(pkt);
2429 
2430 	skb = nlmsg_new(mrt6msg_netlink_msgsize(payloadlen), GFP_ATOMIC);
2431 	if (!skb)
2432 		goto errout;
2433 
2434 	nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT,
2435 			sizeof(struct rtgenmsg), 0);
2436 	if (!nlh)
2437 		goto errout;
2438 	rtgenm = nlmsg_data(nlh);
2439 	rtgenm->rtgen_family = RTNL_FAMILY_IP6MR;
2440 	if (nla_put_u8(skb, IP6MRA_CREPORT_MSGTYPE, msg->im6_msgtype) ||
2441 	    nla_put_u32(skb, IP6MRA_CREPORT_MIF_ID, msg->im6_mif) ||
2442 	    nla_put_in6_addr(skb, IP6MRA_CREPORT_SRC_ADDR,
2443 			     &msg->im6_src) ||
2444 	    nla_put_in6_addr(skb, IP6MRA_CREPORT_DST_ADDR,
2445 			     &msg->im6_dst))
2446 		goto nla_put_failure;
2447 
2448 	nla = nla_reserve(skb, IP6MRA_CREPORT_PKT, payloadlen);
2449 	if (!nla || skb_copy_bits(pkt, sizeof(struct mrt6msg),
2450 				  nla_data(nla), payloadlen))
2451 		goto nla_put_failure;
2452 
2453 	nlmsg_end(skb, nlh);
2454 
2455 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_MROUTE_R, NULL, GFP_ATOMIC);
2456 	return;
2457 
2458 nla_put_failure:
2459 	nlmsg_cancel(skb, nlh);
2460 errout:
2461 	kfree_skb(skb);
2462 	rtnl_set_sk_err(net, RTNLGRP_IPV6_MROUTE_R, -ENOBUFS);
2463 }
2464 
2465 static int ip6mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2466 {
2467 	const struct nlmsghdr *nlh = cb->nlh;
2468 	struct fib_dump_filter filter = {};
2469 	int err;
2470 
2471 	if (cb->strict_check) {
2472 		err = ip_valid_fib_dump_req(sock_net(skb->sk), nlh,
2473 					    &filter, cb);
2474 		if (err < 0)
2475 			return err;
2476 	}
2477 
2478 	if (filter.table_id) {
2479 		struct mr_table *mrt;
2480 
2481 		mrt = ip6mr_get_table(sock_net(skb->sk), filter.table_id);
2482 		if (!mrt) {
2483 			if (filter.dump_all_families)
2484 				return skb->len;
2485 
2486 			NL_SET_ERR_MSG_MOD(cb->extack, "MR table does not exist");
2487 			return -ENOENT;
2488 		}
2489 		err = mr_table_dump(mrt, skb, cb, _ip6mr_fill_mroute,
2490 				    &mfc_unres_lock, &filter);
2491 		return skb->len ? : err;
2492 	}
2493 
2494 	return mr_rtm_dumproute(skb, cb, ip6mr_mr_table_iter,
2495 				_ip6mr_fill_mroute, &mfc_unres_lock, &filter);
2496 }
2497