xref: /linux/net/ipv6/ip6mr.c (revision f15e3b3ddb9fab1c1731b6154e2cd6573fb54c4d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *	Linux IPv6 multicast routing support for BSD pim6sd
4  *	Based on net/ipv4/ipmr.c.
5  *
6  *	(c) 2004 Mickael Hoerdt, <hoerdt@clarinet.u-strasbg.fr>
7  *		LSIIT Laboratory, Strasbourg, France
8  *	(c) 2004 Jean-Philippe Andriot, <jean-philippe.andriot@6WIND.com>
9  *		6WIND, Paris, France
10  *	Copyright (C)2007,2008 USAGI/WIDE Project
11  *		YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
12  */
13 
14 #include <linux/uaccess.h>
15 #include <linux/types.h>
16 #include <linux/sched.h>
17 #include <linux/errno.h>
18 #include <linux/mm.h>
19 #include <linux/kernel.h>
20 #include <linux/fcntl.h>
21 #include <linux/stat.h>
22 #include <linux/socket.h>
23 #include <linux/inet.h>
24 #include <linux/netdevice.h>
25 #include <linux/inetdevice.h>
26 #include <linux/proc_fs.h>
27 #include <linux/seq_file.h>
28 #include <linux/init.h>
29 #include <linux/compat.h>
30 #include <linux/rhashtable.h>
31 #include <net/protocol.h>
32 #include <linux/skbuff.h>
33 #include <net/raw.h>
34 #include <linux/notifier.h>
35 #include <linux/if_arp.h>
36 #include <net/checksum.h>
37 #include <net/netlink.h>
38 #include <net/fib_rules.h>
39 
40 #include <net/ipv6.h>
41 #include <net/ip6_route.h>
42 #include <linux/mroute6.h>
43 #include <linux/pim.h>
44 #include <net/addrconf.h>
45 #include <linux/netfilter_ipv6.h>
46 #include <linux/export.h>
47 #include <net/ip6_checksum.h>
48 #include <linux/netconf.h>
49 #include <net/ip_tunnels.h>
50 
51 #include <linux/nospec.h>
52 
53 struct ip6mr_rule {
54 	struct fib_rule		common;
55 };
56 
57 struct ip6mr_result {
58 	struct mr_table	*mrt;
59 };
60 
61 /* Big lock, protecting vif table, mrt cache and mroute socket state.
62    Note that the changes are semaphored via rtnl_lock.
63  */
64 
65 static DEFINE_SPINLOCK(mrt_lock);
66 
67 static struct net_device *vif_dev_read(const struct vif_device *vif)
68 {
69 	return rcu_dereference(vif->dev);
70 }
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(const 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(const struct mr_table *mrt, struct sk_buff *pkt);
98 static int ip6mr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
99 			      struct netlink_ext_ack *extack);
100 static int ip6mr_rtm_dumproute(struct sk_buff *skb,
101 			       struct netlink_callback *cb);
102 static void mroute_clean_tables(struct mr_table *mrt, int flags);
103 static void ipmr_expire_process(struct timer_list *t);
104 
105 #ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
106 #define ip6mr_for_each_table(mrt, net) \
107 	list_for_each_entry_rcu(mrt, &net->ipv6.mr6_tables, list, \
108 				lockdep_rtnl_is_held() || \
109 				list_empty(&net->ipv6.mr6_tables))
110 
111 static struct mr_table *ip6mr_mr_table_iter(struct net *net,
112 					    struct mr_table *mrt)
113 {
114 	struct mr_table *ret;
115 
116 	if (!mrt)
117 		ret = list_entry_rcu(net->ipv6.mr6_tables.next,
118 				     struct mr_table, list);
119 	else
120 		ret = list_entry_rcu(mrt->list.next,
121 				     struct mr_table, list);
122 
123 	if (&ret->list == &net->ipv6.mr6_tables)
124 		return NULL;
125 	return ret;
126 }
127 
128 static struct mr_table *ip6mr_get_table(struct net *net, u32 id)
129 {
130 	struct mr_table *mrt;
131 
132 	ip6mr_for_each_table(mrt, net) {
133 		if (mrt->id == id)
134 			return mrt;
135 	}
136 	return NULL;
137 }
138 
139 static int ip6mr_fib_lookup(struct net *net, struct flowi6 *flp6,
140 			    struct mr_table **mrt)
141 {
142 	int err;
143 	struct ip6mr_result res;
144 	struct fib_lookup_arg arg = {
145 		.result = &res,
146 		.flags = FIB_LOOKUP_NOREF,
147 	};
148 
149 	/* update flow if oif or iif point to device enslaved to l3mdev */
150 	l3mdev_update_flow(net, flowi6_to_flowi(flp6));
151 
152 	err = fib_rules_lookup(net->ipv6.mr6_rules_ops,
153 			       flowi6_to_flowi(flp6), 0, &arg);
154 	if (err < 0)
155 		return err;
156 	*mrt = res.mrt;
157 	return 0;
158 }
159 
160 static int ip6mr_rule_action(struct fib_rule *rule, struct flowi *flp,
161 			     int flags, struct fib_lookup_arg *arg)
162 {
163 	struct ip6mr_result *res = arg->result;
164 	struct mr_table *mrt;
165 
166 	switch (rule->action) {
167 	case FR_ACT_TO_TBL:
168 		break;
169 	case FR_ACT_UNREACHABLE:
170 		return -ENETUNREACH;
171 	case FR_ACT_PROHIBIT:
172 		return -EACCES;
173 	case FR_ACT_BLACKHOLE:
174 	default:
175 		return -EINVAL;
176 	}
177 
178 	arg->table = fib_rule_get_table(rule, arg);
179 
180 	mrt = ip6mr_get_table(rule->fr_net, arg->table);
181 	if (!mrt)
182 		return -EAGAIN;
183 	res->mrt = mrt;
184 	return 0;
185 }
186 
187 static int ip6mr_rule_match(struct fib_rule *rule, struct flowi *flp, int flags)
188 {
189 	return 1;
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 	.owner		= THIS_MODULE,
225 };
226 
227 static int __net_init ip6mr_rules_init(struct net *net)
228 {
229 	struct fib_rules_ops *ops;
230 	struct mr_table *mrt;
231 	int err;
232 
233 	ops = fib_rules_register(&ip6mr_rules_ops_template, net);
234 	if (IS_ERR(ops))
235 		return PTR_ERR(ops);
236 
237 	INIT_LIST_HEAD(&net->ipv6.mr6_tables);
238 
239 	mrt = ip6mr_new_table(net, RT6_TABLE_DFLT);
240 	if (IS_ERR(mrt)) {
241 		err = PTR_ERR(mrt);
242 		goto err1;
243 	}
244 
245 	err = fib_default_rule_add(ops, 0x7fff, RT6_TABLE_DFLT);
246 	if (err < 0)
247 		goto err2;
248 
249 	net->ipv6.mr6_rules_ops = ops;
250 	return 0;
251 
252 err2:
253 	rtnl_lock();
254 	ip6mr_free_table(mrt);
255 	rtnl_unlock();
256 err1:
257 	fib_rules_unregister(ops);
258 	return err;
259 }
260 
261 static void __net_exit ip6mr_rules_exit(struct net *net)
262 {
263 	struct mr_table *mrt, *next;
264 
265 	ASSERT_RTNL();
266 	list_for_each_entry_safe(mrt, next, &net->ipv6.mr6_tables, list) {
267 		list_del(&mrt->list);
268 		ip6mr_free_table(mrt);
269 	}
270 	fib_rules_unregister(net->ipv6.mr6_rules_ops);
271 }
272 
273 static int ip6mr_rules_dump(struct net *net, struct notifier_block *nb,
274 			    struct netlink_ext_ack *extack)
275 {
276 	return fib_rules_dump(net, nb, RTNL_FAMILY_IP6MR, extack);
277 }
278 
279 static unsigned int ip6mr_rules_seq_read(const struct net *net)
280 {
281 	return fib_rules_seq_read(net, RTNL_FAMILY_IP6MR);
282 }
283 
284 bool ip6mr_rule_default(const struct fib_rule *rule)
285 {
286 	return fib_rule_matchall(rule) && rule->action == FR_ACT_TO_TBL &&
287 	       rule->table == RT6_TABLE_DFLT && !rule->l3mdev;
288 }
289 EXPORT_SYMBOL(ip6mr_rule_default);
290 #else
291 #define ip6mr_for_each_table(mrt, net) \
292 	for (mrt = net->ipv6.mrt6; mrt; mrt = NULL)
293 
294 static struct mr_table *ip6mr_mr_table_iter(struct net *net,
295 					    struct mr_table *mrt)
296 {
297 	if (!mrt)
298 		return net->ipv6.mrt6;
299 	return NULL;
300 }
301 
302 static struct mr_table *ip6mr_get_table(struct net *net, u32 id)
303 {
304 	return net->ipv6.mrt6;
305 }
306 
307 static int ip6mr_fib_lookup(struct net *net, struct flowi6 *flp6,
308 			    struct mr_table **mrt)
309 {
310 	*mrt = net->ipv6.mrt6;
311 	return 0;
312 }
313 
314 static int __net_init ip6mr_rules_init(struct net *net)
315 {
316 	struct mr_table *mrt;
317 
318 	mrt = ip6mr_new_table(net, RT6_TABLE_DFLT);
319 	if (IS_ERR(mrt))
320 		return PTR_ERR(mrt);
321 	net->ipv6.mrt6 = mrt;
322 	return 0;
323 }
324 
325 static void __net_exit ip6mr_rules_exit(struct net *net)
326 {
327 	ASSERT_RTNL();
328 	ip6mr_free_table(net->ipv6.mrt6);
329 	net->ipv6.mrt6 = NULL;
330 }
331 
332 static int ip6mr_rules_dump(struct net *net, struct notifier_block *nb,
333 			    struct netlink_ext_ack *extack)
334 {
335 	return 0;
336 }
337 
338 static unsigned int ip6mr_rules_seq_read(const struct net *net)
339 {
340 	return 0;
341 }
342 #endif
343 
344 static int ip6mr_hash_cmp(struct rhashtable_compare_arg *arg,
345 			  const void *ptr)
346 {
347 	const struct mfc6_cache_cmp_arg *cmparg = arg->key;
348 	struct mfc6_cache *c = (struct mfc6_cache *)ptr;
349 
350 	return !ipv6_addr_equal(&c->mf6c_mcastgrp, &cmparg->mf6c_mcastgrp) ||
351 	       !ipv6_addr_equal(&c->mf6c_origin, &cmparg->mf6c_origin);
352 }
353 
354 static const struct rhashtable_params ip6mr_rht_params = {
355 	.head_offset = offsetof(struct mr_mfc, mnode),
356 	.key_offset = offsetof(struct mfc6_cache, cmparg),
357 	.key_len = sizeof(struct mfc6_cache_cmp_arg),
358 	.nelem_hint = 3,
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 	timer_shutdown_sync(&mrt->ipmr_expire_timer);
396 	mroute_clean_tables(mrt, MRT6_FLUSH_MIFS | MRT6_FLUSH_MIFS_STATIC |
397 				 MRT6_FLUSH_MFC | MRT6_FLUSH_MFC_STATIC);
398 	rhltable_destroy(&mrt->mfc_hash);
399 	kfree(mrt);
400 }
401 
402 #ifdef CONFIG_PROC_FS
403 /* The /proc interfaces to multicast routing
404  * /proc/ip6_mr_cache /proc/ip6_mr_vif
405  */
406 
407 static void *ip6mr_vif_seq_start(struct seq_file *seq, loff_t *pos)
408 	__acquires(RCU)
409 {
410 	struct mr_vif_iter *iter = seq->private;
411 	struct net *net = seq_file_net(seq);
412 	struct mr_table *mrt;
413 
414 	mrt = ip6mr_get_table(net, RT6_TABLE_DFLT);
415 	if (!mrt)
416 		return ERR_PTR(-ENOENT);
417 
418 	iter->mrt = mrt;
419 
420 	rcu_read_lock();
421 	return mr_vif_seq_start(seq, pos);
422 }
423 
424 static void ip6mr_vif_seq_stop(struct seq_file *seq, void *v)
425 	__releases(RCU)
426 {
427 	rcu_read_unlock();
428 }
429 
430 static int ip6mr_vif_seq_show(struct seq_file *seq, void *v)
431 {
432 	struct mr_vif_iter *iter = seq->private;
433 	struct mr_table *mrt = iter->mrt;
434 
435 	if (v == SEQ_START_TOKEN) {
436 		seq_puts(seq,
437 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags\n");
438 	} else {
439 		const struct vif_device *vif = v;
440 		const struct net_device *vif_dev;
441 		const char *name;
442 
443 		vif_dev = vif_dev_read(vif);
444 		name = vif_dev ? vif_dev->name : "none";
445 
446 		seq_printf(seq,
447 			   "%2td %-10s %8ld %7ld  %8ld %7ld %05X\n",
448 			   vif - mrt->vif_table,
449 			   name, vif->bytes_in, vif->pkt_in,
450 			   vif->bytes_out, vif->pkt_out,
451 			   vif->flags);
452 	}
453 	return 0;
454 }
455 
456 static const struct seq_operations ip6mr_vif_seq_ops = {
457 	.start = ip6mr_vif_seq_start,
458 	.next  = mr_vif_seq_next,
459 	.stop  = ip6mr_vif_seq_stop,
460 	.show  = ip6mr_vif_seq_show,
461 };
462 
463 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
464 {
465 	struct net *net = seq_file_net(seq);
466 	struct mr_table *mrt;
467 
468 	mrt = ip6mr_get_table(net, RT6_TABLE_DFLT);
469 	if (!mrt)
470 		return ERR_PTR(-ENOENT);
471 
472 	return mr_mfc_seq_start(seq, pos, mrt, &mfc_unres_lock);
473 }
474 
475 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
476 {
477 	int n;
478 
479 	if (v == SEQ_START_TOKEN) {
480 		seq_puts(seq,
481 			 "Group                            "
482 			 "Origin                           "
483 			 "Iif      Pkts  Bytes     Wrong  Oifs\n");
484 	} else {
485 		const struct mfc6_cache *mfc = v;
486 		const struct mr_mfc_iter *it = seq->private;
487 		struct mr_table *mrt = it->mrt;
488 
489 		seq_printf(seq, "%pI6 %pI6 %-3hd",
490 			   &mfc->mf6c_mcastgrp, &mfc->mf6c_origin,
491 			   mfc->_c.mfc_parent);
492 
493 		if (it->cache != &mrt->mfc_unres_queue) {
494 			seq_printf(seq, " %8lu %8lu %8lu",
495 				   mfc->_c.mfc_un.res.pkt,
496 				   mfc->_c.mfc_un.res.bytes,
497 				   mfc->_c.mfc_un.res.wrong_if);
498 			for (n = mfc->_c.mfc_un.res.minvif;
499 			     n < mfc->_c.mfc_un.res.maxvif; n++) {
500 				if (VIF_EXISTS(mrt, n) &&
501 				    mfc->_c.mfc_un.res.ttls[n] < 255)
502 					seq_printf(seq,
503 						   " %2d:%-3d", n,
504 						   mfc->_c.mfc_un.res.ttls[n]);
505 			}
506 		} else {
507 			/* unresolved mfc_caches don't contain
508 			 * pkt, bytes and wrong_if values
509 			 */
510 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
511 		}
512 		seq_putc(seq, '\n');
513 	}
514 	return 0;
515 }
516 
517 static const struct seq_operations ipmr_mfc_seq_ops = {
518 	.start = ipmr_mfc_seq_start,
519 	.next  = mr_mfc_seq_next,
520 	.stop  = mr_mfc_seq_stop,
521 	.show  = ipmr_mfc_seq_show,
522 };
523 #endif
524 
525 #ifdef CONFIG_IPV6_PIMSM_V2
526 
527 static int pim6_rcv(struct sk_buff *skb)
528 {
529 	struct pimreghdr *pim;
530 	struct ipv6hdr   *encap;
531 	struct net_device  *reg_dev = NULL;
532 	struct net *net = dev_net(skb->dev);
533 	struct mr_table *mrt;
534 	struct flowi6 fl6 = {
535 		.flowi6_iif	= skb->dev->ifindex,
536 		.flowi6_mark	= skb->mark,
537 	};
538 	int reg_vif_num;
539 
540 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap)))
541 		goto drop;
542 
543 	pim = (struct pimreghdr *)skb_transport_header(skb);
544 	if (pim->type != ((PIM_VERSION << 4) | PIM_TYPE_REGISTER) ||
545 	    (pim->flags & PIM_NULL_REGISTER) ||
546 	    (csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
547 			     sizeof(*pim), IPPROTO_PIM,
548 			     csum_partial((void *)pim, sizeof(*pim), 0)) &&
549 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
550 		goto drop;
551 
552 	/* check if the inner packet is destined to mcast group */
553 	encap = (struct ipv6hdr *)(skb_transport_header(skb) +
554 				   sizeof(*pim));
555 
556 	if (!ipv6_addr_is_multicast(&encap->daddr) ||
557 	    encap->payload_len == 0 ||
558 	    ntohs(encap->payload_len) + sizeof(*pim) > skb->len)
559 		goto drop;
560 
561 	if (ip6mr_fib_lookup(net, &fl6, &mrt) < 0)
562 		goto drop;
563 
564 	/* Pairs with WRITE_ONCE() in mif6_add()/mif6_delete() */
565 	reg_vif_num = READ_ONCE(mrt->mroute_reg_vif_num);
566 	if (reg_vif_num >= 0)
567 		reg_dev = vif_dev_read(&mrt->vif_table[reg_vif_num]);
568 
569 	if (!reg_dev)
570 		goto drop;
571 
572 	skb->mac_header = skb->network_header;
573 	skb_pull(skb, (u8 *)encap - skb->data);
574 	skb_reset_network_header(skb);
575 	skb->protocol = htons(ETH_P_IPV6);
576 	skb->ip_summed = CHECKSUM_NONE;
577 
578 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
579 
580 	netif_rx(skb);
581 
582 	return 0;
583  drop:
584 	kfree_skb(skb);
585 	return 0;
586 }
587 
588 static const struct inet6_protocol pim6_protocol = {
589 	.handler	=	pim6_rcv,
590 };
591 
592 /* Service routines creating virtual interfaces: PIMREG */
593 
594 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb,
595 				      struct net_device *dev)
596 {
597 	struct net *net = dev_net(dev);
598 	struct mr_table *mrt;
599 	struct flowi6 fl6 = {
600 		.flowi6_oif	= dev->ifindex,
601 		.flowi6_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
602 		.flowi6_mark	= skb->mark,
603 	};
604 
605 	if (!pskb_inet_may_pull(skb))
606 		goto tx_err;
607 
608 	if (ip6mr_fib_lookup(net, &fl6, &mrt) < 0)
609 		goto tx_err;
610 
611 	DEV_STATS_ADD(dev, tx_bytes, skb->len);
612 	DEV_STATS_INC(dev, tx_packets);
613 	rcu_read_lock();
614 	ip6mr_cache_report(mrt, skb, READ_ONCE(mrt->mroute_reg_vif_num),
615 			   MRT6MSG_WHOLEPKT);
616 	rcu_read_unlock();
617 	kfree_skb(skb);
618 	return NETDEV_TX_OK;
619 
620 tx_err:
621 	DEV_STATS_INC(dev, tx_errors);
622 	kfree_skb(skb);
623 	return NETDEV_TX_OK;
624 }
625 
626 static int reg_vif_get_iflink(const struct net_device *dev)
627 {
628 	return 0;
629 }
630 
631 static const struct net_device_ops reg_vif_netdev_ops = {
632 	.ndo_start_xmit	= reg_vif_xmit,
633 	.ndo_get_iflink = reg_vif_get_iflink,
634 };
635 
636 static void reg_vif_setup(struct net_device *dev)
637 {
638 	dev->type		= ARPHRD_PIMREG;
639 	dev->mtu		= 1500 - sizeof(struct ipv6hdr) - 8;
640 	dev->flags		= IFF_NOARP;
641 	dev->netdev_ops		= &reg_vif_netdev_ops;
642 	dev->needs_free_netdev	= true;
643 	dev->netns_local	= true;
644 }
645 
646 static struct net_device *ip6mr_reg_vif(struct net *net, struct mr_table *mrt)
647 {
648 	struct net_device *dev;
649 	char name[IFNAMSIZ];
650 
651 	if (mrt->id == RT6_TABLE_DFLT)
652 		sprintf(name, "pim6reg");
653 	else
654 		sprintf(name, "pim6reg%u", mrt->id);
655 
656 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
657 	if (!dev)
658 		return NULL;
659 
660 	dev_net_set(dev, net);
661 
662 	if (register_netdevice(dev)) {
663 		free_netdev(dev);
664 		return NULL;
665 	}
666 
667 	if (dev_open(dev, NULL))
668 		goto failure;
669 
670 	dev_hold(dev);
671 	return dev;
672 
673 failure:
674 	unregister_netdevice(dev);
675 	return NULL;
676 }
677 #endif
678 
679 static int call_ip6mr_vif_entry_notifiers(struct net *net,
680 					  enum fib_event_type event_type,
681 					  struct vif_device *vif,
682 					  struct net_device *vif_dev,
683 					  mifi_t vif_index, u32 tb_id)
684 {
685 	return mr_call_vif_notifiers(net, RTNL_FAMILY_IP6MR, event_type,
686 				     vif, vif_dev, vif_index, tb_id,
687 				     &net->ipv6.ipmr_seq);
688 }
689 
690 static int call_ip6mr_mfc_entry_notifiers(struct net *net,
691 					  enum fib_event_type event_type,
692 					  struct mfc6_cache *mfc, u32 tb_id)
693 {
694 	return mr_call_mfc_notifiers(net, RTNL_FAMILY_IP6MR, event_type,
695 				     &mfc->_c, tb_id, &net->ipv6.ipmr_seq);
696 }
697 
698 /* Delete a VIF entry */
699 static int mif6_delete(struct mr_table *mrt, int vifi, int notify,
700 		       struct list_head *head)
701 {
702 	struct vif_device *v;
703 	struct net_device *dev;
704 	struct inet6_dev *in6_dev;
705 
706 	if (vifi < 0 || vifi >= mrt->maxvif)
707 		return -EADDRNOTAVAIL;
708 
709 	v = &mrt->vif_table[vifi];
710 
711 	dev = rtnl_dereference(v->dev);
712 	if (!dev)
713 		return -EADDRNOTAVAIL;
714 
715 	call_ip6mr_vif_entry_notifiers(read_pnet(&mrt->net),
716 				       FIB_EVENT_VIF_DEL, v, dev,
717 				       vifi, mrt->id);
718 	spin_lock(&mrt_lock);
719 	RCU_INIT_POINTER(v->dev, NULL);
720 
721 #ifdef CONFIG_IPV6_PIMSM_V2
722 	if (vifi == mrt->mroute_reg_vif_num) {
723 		/* Pairs with READ_ONCE() in ip6mr_cache_report() and reg_vif_xmit() */
724 		WRITE_ONCE(mrt->mroute_reg_vif_num, -1);
725 	}
726 #endif
727 
728 	if (vifi + 1 == mrt->maxvif) {
729 		int tmp;
730 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
731 			if (VIF_EXISTS(mrt, tmp))
732 				break;
733 		}
734 		WRITE_ONCE(mrt->maxvif, tmp + 1);
735 	}
736 
737 	spin_unlock(&mrt_lock);
738 
739 	dev_set_allmulti(dev, -1);
740 
741 	in6_dev = __in6_dev_get(dev);
742 	if (in6_dev) {
743 		atomic_dec(&in6_dev->cnf.mc_forwarding);
744 		inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
745 					     NETCONFA_MC_FORWARDING,
746 					     dev->ifindex, &in6_dev->cnf);
747 	}
748 
749 	if ((v->flags & MIFF_REGISTER) && !notify)
750 		unregister_netdevice_queue(dev, head);
751 
752 	netdev_put(dev, &v->dev_tracker);
753 	return 0;
754 }
755 
756 static inline void ip6mr_cache_free_rcu(struct rcu_head *head)
757 {
758 	struct mr_mfc *c = container_of(head, struct mr_mfc, rcu);
759 
760 	kmem_cache_free(mrt_cachep, (struct mfc6_cache *)c);
761 }
762 
763 static inline void ip6mr_cache_free(struct mfc6_cache *c)
764 {
765 	call_rcu(&c->_c.rcu, ip6mr_cache_free_rcu);
766 }
767 
768 /* Destroy an unresolved cache entry, killing queued skbs
769    and reporting error to netlink readers.
770  */
771 
772 static void ip6mr_destroy_unres(struct mr_table *mrt, struct mfc6_cache *c)
773 {
774 	struct net *net = read_pnet(&mrt->net);
775 	struct sk_buff *skb;
776 
777 	atomic_dec(&mrt->cache_resolve_queue_len);
778 
779 	while ((skb = skb_dequeue(&c->_c.mfc_un.unres.unresolved)) != NULL) {
780 		if (ipv6_hdr(skb)->version == 0) {
781 			struct nlmsghdr *nlh = skb_pull(skb,
782 							sizeof(struct ipv6hdr));
783 			nlh->nlmsg_type = NLMSG_ERROR;
784 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
785 			skb_trim(skb, nlh->nlmsg_len);
786 			((struct nlmsgerr *)nlmsg_data(nlh))->error = -ETIMEDOUT;
787 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
788 		} else
789 			kfree_skb(skb);
790 	}
791 
792 	ip6mr_cache_free(c);
793 }
794 
795 
796 /* Timer process for all the unresolved queue. */
797 
798 static void ipmr_do_expire_process(struct mr_table *mrt)
799 {
800 	unsigned long now = jiffies;
801 	unsigned long expires = 10 * HZ;
802 	struct mr_mfc *c, *next;
803 
804 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
805 		if (time_after(c->mfc_un.unres.expires, now)) {
806 			/* not yet... */
807 			unsigned long interval = c->mfc_un.unres.expires - now;
808 			if (interval < expires)
809 				expires = interval;
810 			continue;
811 		}
812 
813 		list_del(&c->list);
814 		mr6_netlink_event(mrt, (struct mfc6_cache *)c, RTM_DELROUTE);
815 		ip6mr_destroy_unres(mrt, (struct mfc6_cache *)c);
816 	}
817 
818 	if (!list_empty(&mrt->mfc_unres_queue))
819 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
820 }
821 
822 static void ipmr_expire_process(struct timer_list *t)
823 {
824 	struct mr_table *mrt = from_timer(mrt, t, ipmr_expire_timer);
825 
826 	if (!spin_trylock(&mfc_unres_lock)) {
827 		mod_timer(&mrt->ipmr_expire_timer, jiffies + 1);
828 		return;
829 	}
830 
831 	if (!list_empty(&mrt->mfc_unres_queue))
832 		ipmr_do_expire_process(mrt);
833 
834 	spin_unlock(&mfc_unres_lock);
835 }
836 
837 /* Fill oifs list. It is called under locked mrt_lock. */
838 
839 static void ip6mr_update_thresholds(struct mr_table *mrt,
840 				    struct mr_mfc *cache,
841 				    unsigned char *ttls)
842 {
843 	int vifi;
844 
845 	cache->mfc_un.res.minvif = MAXMIFS;
846 	cache->mfc_un.res.maxvif = 0;
847 	memset(cache->mfc_un.res.ttls, 255, MAXMIFS);
848 
849 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
850 		if (VIF_EXISTS(mrt, vifi) &&
851 		    ttls[vifi] && ttls[vifi] < 255) {
852 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
853 			if (cache->mfc_un.res.minvif > vifi)
854 				cache->mfc_un.res.minvif = vifi;
855 			if (cache->mfc_un.res.maxvif <= vifi)
856 				cache->mfc_un.res.maxvif = vifi + 1;
857 		}
858 	}
859 	cache->mfc_un.res.lastuse = jiffies;
860 }
861 
862 static int mif6_add(struct net *net, struct mr_table *mrt,
863 		    struct mif6ctl *vifc, int mrtsock)
864 {
865 	int vifi = vifc->mif6c_mifi;
866 	struct vif_device *v = &mrt->vif_table[vifi];
867 	struct net_device *dev;
868 	struct inet6_dev *in6_dev;
869 	int err;
870 
871 	/* Is vif busy ? */
872 	if (VIF_EXISTS(mrt, vifi))
873 		return -EADDRINUSE;
874 
875 	switch (vifc->mif6c_flags) {
876 #ifdef CONFIG_IPV6_PIMSM_V2
877 	case MIFF_REGISTER:
878 		/*
879 		 * Special Purpose VIF in PIM
880 		 * All the packets will be sent to the daemon
881 		 */
882 		if (mrt->mroute_reg_vif_num >= 0)
883 			return -EADDRINUSE;
884 		dev = ip6mr_reg_vif(net, mrt);
885 		if (!dev)
886 			return -ENOBUFS;
887 		err = dev_set_allmulti(dev, 1);
888 		if (err) {
889 			unregister_netdevice(dev);
890 			dev_put(dev);
891 			return err;
892 		}
893 		break;
894 #endif
895 	case 0:
896 		dev = dev_get_by_index(net, vifc->mif6c_pifi);
897 		if (!dev)
898 			return -EADDRNOTAVAIL;
899 		err = dev_set_allmulti(dev, 1);
900 		if (err) {
901 			dev_put(dev);
902 			return err;
903 		}
904 		break;
905 	default:
906 		return -EINVAL;
907 	}
908 
909 	in6_dev = __in6_dev_get(dev);
910 	if (in6_dev) {
911 		atomic_inc(&in6_dev->cnf.mc_forwarding);
912 		inet6_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
913 					     NETCONFA_MC_FORWARDING,
914 					     dev->ifindex, &in6_dev->cnf);
915 	}
916 
917 	/* Fill in the VIF structures */
918 	vif_device_init(v, dev, vifc->vifc_rate_limit, vifc->vifc_threshold,
919 			vifc->mif6c_flags | (!mrtsock ? VIFF_STATIC : 0),
920 			MIFF_REGISTER);
921 
922 	/* And finish update writing critical data */
923 	spin_lock(&mrt_lock);
924 	rcu_assign_pointer(v->dev, dev);
925 	netdev_tracker_alloc(dev, &v->dev_tracker, GFP_ATOMIC);
926 #ifdef CONFIG_IPV6_PIMSM_V2
927 	if (v->flags & MIFF_REGISTER)
928 		WRITE_ONCE(mrt->mroute_reg_vif_num, vifi);
929 #endif
930 	if (vifi + 1 > mrt->maxvif)
931 		WRITE_ONCE(mrt->maxvif, vifi + 1);
932 	spin_unlock(&mrt_lock);
933 	call_ip6mr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD,
934 				       v, dev, vifi, mrt->id);
935 	return 0;
936 }
937 
938 static struct mfc6_cache *ip6mr_cache_find(struct mr_table *mrt,
939 					   const struct in6_addr *origin,
940 					   const struct in6_addr *mcastgrp)
941 {
942 	struct mfc6_cache_cmp_arg arg = {
943 		.mf6c_origin = *origin,
944 		.mf6c_mcastgrp = *mcastgrp,
945 	};
946 
947 	return mr_mfc_find(mrt, &arg);
948 }
949 
950 /* Look for a (*,G) entry */
951 static struct mfc6_cache *ip6mr_cache_find_any(struct mr_table *mrt,
952 					       struct in6_addr *mcastgrp,
953 					       mifi_t mifi)
954 {
955 	struct mfc6_cache_cmp_arg arg = {
956 		.mf6c_origin = in6addr_any,
957 		.mf6c_mcastgrp = *mcastgrp,
958 	};
959 
960 	if (ipv6_addr_any(mcastgrp))
961 		return mr_mfc_find_any_parent(mrt, mifi);
962 	return mr_mfc_find_any(mrt, mifi, &arg);
963 }
964 
965 /* Look for a (S,G,iif) entry if parent != -1 */
966 static struct mfc6_cache *
967 ip6mr_cache_find_parent(struct mr_table *mrt,
968 			const struct in6_addr *origin,
969 			const struct in6_addr *mcastgrp,
970 			int parent)
971 {
972 	struct mfc6_cache_cmp_arg arg = {
973 		.mf6c_origin = *origin,
974 		.mf6c_mcastgrp = *mcastgrp,
975 	};
976 
977 	return mr_mfc_find_parent(mrt, &arg, parent);
978 }
979 
980 /* Allocate a multicast cache entry */
981 static struct mfc6_cache *ip6mr_cache_alloc(void)
982 {
983 	struct mfc6_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
984 	if (!c)
985 		return NULL;
986 	c->_c.mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
987 	c->_c.mfc_un.res.minvif = MAXMIFS;
988 	c->_c.free = ip6mr_cache_free_rcu;
989 	refcount_set(&c->_c.mfc_un.res.refcount, 1);
990 	return c;
991 }
992 
993 static struct mfc6_cache *ip6mr_cache_alloc_unres(void)
994 {
995 	struct mfc6_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
996 	if (!c)
997 		return NULL;
998 	skb_queue_head_init(&c->_c.mfc_un.unres.unresolved);
999 	c->_c.mfc_un.unres.expires = jiffies + 10 * HZ;
1000 	return c;
1001 }
1002 
1003 /*
1004  *	A cache entry has gone into a resolved state from queued
1005  */
1006 
1007 static void ip6mr_cache_resolve(struct net *net, struct mr_table *mrt,
1008 				struct mfc6_cache *uc, struct mfc6_cache *c)
1009 {
1010 	struct sk_buff *skb;
1011 
1012 	/*
1013 	 *	Play the pending entries through our router
1014 	 */
1015 
1016 	while ((skb = __skb_dequeue(&uc->_c.mfc_un.unres.unresolved))) {
1017 		if (ipv6_hdr(skb)->version == 0) {
1018 			struct nlmsghdr *nlh = skb_pull(skb,
1019 							sizeof(struct ipv6hdr));
1020 
1021 			if (mr_fill_mroute(mrt, skb, &c->_c,
1022 					   nlmsg_data(nlh)) > 0) {
1023 				nlh->nlmsg_len = skb_tail_pointer(skb) - (u8 *)nlh;
1024 			} else {
1025 				nlh->nlmsg_type = NLMSG_ERROR;
1026 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
1027 				skb_trim(skb, nlh->nlmsg_len);
1028 				((struct nlmsgerr *)nlmsg_data(nlh))->error = -EMSGSIZE;
1029 			}
1030 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
1031 		} else {
1032 			rcu_read_lock();
1033 			ip6_mr_forward(net, mrt, skb->dev, skb, c);
1034 			rcu_read_unlock();
1035 		}
1036 	}
1037 }
1038 
1039 /*
1040  *	Bounce a cache query up to pim6sd and netlink.
1041  *
1042  *	Called under rcu_read_lock()
1043  */
1044 
1045 static int ip6mr_cache_report(const struct mr_table *mrt, struct sk_buff *pkt,
1046 			      mifi_t mifi, int assert)
1047 {
1048 	struct sock *mroute6_sk;
1049 	struct sk_buff *skb;
1050 	struct mrt6msg *msg;
1051 	int ret;
1052 
1053 #ifdef CONFIG_IPV6_PIMSM_V2
1054 	if (assert == MRT6MSG_WHOLEPKT || assert == MRT6MSG_WRMIFWHOLE)
1055 		skb = skb_realloc_headroom(pkt, -skb_network_offset(pkt)
1056 						+sizeof(*msg));
1057 	else
1058 #endif
1059 		skb = alloc_skb(sizeof(struct ipv6hdr) + sizeof(*msg), GFP_ATOMIC);
1060 
1061 	if (!skb)
1062 		return -ENOBUFS;
1063 
1064 	/* I suppose that internal messages
1065 	 * do not require checksums */
1066 
1067 	skb->ip_summed = CHECKSUM_UNNECESSARY;
1068 
1069 #ifdef CONFIG_IPV6_PIMSM_V2
1070 	if (assert == MRT6MSG_WHOLEPKT || assert == MRT6MSG_WRMIFWHOLE) {
1071 		/* Ugly, but we have no choice with this interface.
1072 		   Duplicate old header, fix length etc.
1073 		   And all this only to mangle msg->im6_msgtype and
1074 		   to set msg->im6_mbz to "mbz" :-)
1075 		 */
1076 		__skb_pull(skb, skb_network_offset(pkt));
1077 
1078 		skb_push(skb, sizeof(*msg));
1079 		skb_reset_transport_header(skb);
1080 		msg = (struct mrt6msg *)skb_transport_header(skb);
1081 		msg->im6_mbz = 0;
1082 		msg->im6_msgtype = assert;
1083 		if (assert == MRT6MSG_WRMIFWHOLE)
1084 			msg->im6_mif = mifi;
1085 		else
1086 			msg->im6_mif = READ_ONCE(mrt->mroute_reg_vif_num);
1087 		msg->im6_pad = 0;
1088 		msg->im6_src = ipv6_hdr(pkt)->saddr;
1089 		msg->im6_dst = ipv6_hdr(pkt)->daddr;
1090 
1091 		skb->ip_summed = CHECKSUM_UNNECESSARY;
1092 	} else
1093 #endif
1094 	{
1095 	/*
1096 	 *	Copy the IP header
1097 	 */
1098 
1099 	skb_put(skb, sizeof(struct ipv6hdr));
1100 	skb_reset_network_header(skb);
1101 	skb_copy_to_linear_data(skb, ipv6_hdr(pkt), sizeof(struct ipv6hdr));
1102 
1103 	/*
1104 	 *	Add our header
1105 	 */
1106 	skb_put(skb, sizeof(*msg));
1107 	skb_reset_transport_header(skb);
1108 	msg = (struct mrt6msg *)skb_transport_header(skb);
1109 
1110 	msg->im6_mbz = 0;
1111 	msg->im6_msgtype = assert;
1112 	msg->im6_mif = mifi;
1113 	msg->im6_pad = 0;
1114 	msg->im6_src = ipv6_hdr(pkt)->saddr;
1115 	msg->im6_dst = ipv6_hdr(pkt)->daddr;
1116 
1117 	skb_dst_set(skb, dst_clone(skb_dst(pkt)));
1118 	skb->ip_summed = CHECKSUM_UNNECESSARY;
1119 	}
1120 
1121 	mroute6_sk = rcu_dereference(mrt->mroute_sk);
1122 	if (!mroute6_sk) {
1123 		kfree_skb(skb);
1124 		return -EINVAL;
1125 	}
1126 
1127 	mrt6msg_netlink_event(mrt, skb);
1128 
1129 	/* Deliver to user space multicast routing algorithms */
1130 	ret = sock_queue_rcv_skb(mroute6_sk, skb);
1131 
1132 	if (ret < 0) {
1133 		net_warn_ratelimited("mroute6: pending queue full, dropping entries\n");
1134 		kfree_skb(skb);
1135 	}
1136 
1137 	return ret;
1138 }
1139 
1140 /* Queue a packet for resolution. It gets locked cache entry! */
1141 static int ip6mr_cache_unresolved(struct mr_table *mrt, mifi_t mifi,
1142 				  struct sk_buff *skb, struct net_device *dev)
1143 {
1144 	struct mfc6_cache *c;
1145 	bool found = false;
1146 	int err;
1147 
1148 	spin_lock_bh(&mfc_unres_lock);
1149 	list_for_each_entry(c, &mrt->mfc_unres_queue, _c.list) {
1150 		if (ipv6_addr_equal(&c->mf6c_mcastgrp, &ipv6_hdr(skb)->daddr) &&
1151 		    ipv6_addr_equal(&c->mf6c_origin, &ipv6_hdr(skb)->saddr)) {
1152 			found = true;
1153 			break;
1154 		}
1155 	}
1156 
1157 	if (!found) {
1158 		/*
1159 		 *	Create a new entry if allowable
1160 		 */
1161 
1162 		c = ip6mr_cache_alloc_unres();
1163 		if (!c) {
1164 			spin_unlock_bh(&mfc_unres_lock);
1165 
1166 			kfree_skb(skb);
1167 			return -ENOBUFS;
1168 		}
1169 
1170 		/* Fill in the new cache entry */
1171 		c->_c.mfc_parent = -1;
1172 		c->mf6c_origin = ipv6_hdr(skb)->saddr;
1173 		c->mf6c_mcastgrp = ipv6_hdr(skb)->daddr;
1174 
1175 		/*
1176 		 *	Reflect first query at pim6sd
1177 		 */
1178 		err = ip6mr_cache_report(mrt, skb, mifi, MRT6MSG_NOCACHE);
1179 		if (err < 0) {
1180 			/* If the report failed throw the cache entry
1181 			   out - Brad Parker
1182 			 */
1183 			spin_unlock_bh(&mfc_unres_lock);
1184 
1185 			ip6mr_cache_free(c);
1186 			kfree_skb(skb);
1187 			return err;
1188 		}
1189 
1190 		atomic_inc(&mrt->cache_resolve_queue_len);
1191 		list_add(&c->_c.list, &mrt->mfc_unres_queue);
1192 		mr6_netlink_event(mrt, c, RTM_NEWROUTE);
1193 
1194 		ipmr_do_expire_process(mrt);
1195 	}
1196 
1197 	/* See if we can append the packet */
1198 	if (c->_c.mfc_un.unres.unresolved.qlen > 3) {
1199 		kfree_skb(skb);
1200 		err = -ENOBUFS;
1201 	} else {
1202 		if (dev) {
1203 			skb->dev = dev;
1204 			skb->skb_iif = dev->ifindex;
1205 		}
1206 		skb_queue_tail(&c->_c.mfc_un.unres.unresolved, skb);
1207 		err = 0;
1208 	}
1209 
1210 	spin_unlock_bh(&mfc_unres_lock);
1211 	return err;
1212 }
1213 
1214 /*
1215  *	MFC6 cache manipulation by user space
1216  */
1217 
1218 static int ip6mr_mfc_delete(struct mr_table *mrt, struct mf6cctl *mfc,
1219 			    int parent)
1220 {
1221 	struct mfc6_cache *c;
1222 
1223 	/* The entries are added/deleted only under RTNL */
1224 	rcu_read_lock();
1225 	c = ip6mr_cache_find_parent(mrt, &mfc->mf6cc_origin.sin6_addr,
1226 				    &mfc->mf6cc_mcastgrp.sin6_addr, parent);
1227 	rcu_read_unlock();
1228 	if (!c)
1229 		return -ENOENT;
1230 	rhltable_remove(&mrt->mfc_hash, &c->_c.mnode, ip6mr_rht_params);
1231 	list_del_rcu(&c->_c.list);
1232 
1233 	call_ip6mr_mfc_entry_notifiers(read_pnet(&mrt->net),
1234 				       FIB_EVENT_ENTRY_DEL, c, mrt->id);
1235 	mr6_netlink_event(mrt, c, RTM_DELROUTE);
1236 	mr_cache_put(&c->_c);
1237 	return 0;
1238 }
1239 
1240 static int ip6mr_device_event(struct notifier_block *this,
1241 			      unsigned long event, void *ptr)
1242 {
1243 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1244 	struct net *net = dev_net(dev);
1245 	struct mr_table *mrt;
1246 	struct vif_device *v;
1247 	int ct;
1248 
1249 	if (event != NETDEV_UNREGISTER)
1250 		return NOTIFY_DONE;
1251 
1252 	ip6mr_for_each_table(mrt, net) {
1253 		v = &mrt->vif_table[0];
1254 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1255 			if (rcu_access_pointer(v->dev) == dev)
1256 				mif6_delete(mrt, ct, 1, NULL);
1257 		}
1258 	}
1259 
1260 	return NOTIFY_DONE;
1261 }
1262 
1263 static unsigned int ip6mr_seq_read(const struct net *net)
1264 {
1265 	return READ_ONCE(net->ipv6.ipmr_seq) + ip6mr_rules_seq_read(net);
1266 }
1267 
1268 static int ip6mr_dump(struct net *net, struct notifier_block *nb,
1269 		      struct netlink_ext_ack *extack)
1270 {
1271 	return mr_dump(net, nb, RTNL_FAMILY_IP6MR, ip6mr_rules_dump,
1272 		       ip6mr_mr_table_iter, extack);
1273 }
1274 
1275 static struct notifier_block ip6_mr_notifier = {
1276 	.notifier_call = ip6mr_device_event
1277 };
1278 
1279 static const struct fib_notifier_ops ip6mr_notifier_ops_template = {
1280 	.family		= RTNL_FAMILY_IP6MR,
1281 	.fib_seq_read	= ip6mr_seq_read,
1282 	.fib_dump	= ip6mr_dump,
1283 	.owner		= THIS_MODULE,
1284 };
1285 
1286 static int __net_init ip6mr_notifier_init(struct net *net)
1287 {
1288 	struct fib_notifier_ops *ops;
1289 
1290 	net->ipv6.ipmr_seq = 0;
1291 
1292 	ops = fib_notifier_ops_register(&ip6mr_notifier_ops_template, net);
1293 	if (IS_ERR(ops))
1294 		return PTR_ERR(ops);
1295 
1296 	net->ipv6.ip6mr_notifier_ops = ops;
1297 
1298 	return 0;
1299 }
1300 
1301 static void __net_exit ip6mr_notifier_exit(struct net *net)
1302 {
1303 	fib_notifier_ops_unregister(net->ipv6.ip6mr_notifier_ops);
1304 	net->ipv6.ip6mr_notifier_ops = NULL;
1305 }
1306 
1307 /* Setup for IP multicast routing */
1308 static int __net_init ip6mr_net_init(struct net *net)
1309 {
1310 	int err;
1311 
1312 	err = ip6mr_notifier_init(net);
1313 	if (err)
1314 		return err;
1315 
1316 	err = ip6mr_rules_init(net);
1317 	if (err < 0)
1318 		goto ip6mr_rules_fail;
1319 
1320 #ifdef CONFIG_PROC_FS
1321 	err = -ENOMEM;
1322 	if (!proc_create_net("ip6_mr_vif", 0, net->proc_net, &ip6mr_vif_seq_ops,
1323 			sizeof(struct mr_vif_iter)))
1324 		goto proc_vif_fail;
1325 	if (!proc_create_net("ip6_mr_cache", 0, net->proc_net, &ipmr_mfc_seq_ops,
1326 			sizeof(struct mr_mfc_iter)))
1327 		goto proc_cache_fail;
1328 #endif
1329 
1330 	return 0;
1331 
1332 #ifdef CONFIG_PROC_FS
1333 proc_cache_fail:
1334 	remove_proc_entry("ip6_mr_vif", net->proc_net);
1335 proc_vif_fail:
1336 	rtnl_lock();
1337 	ip6mr_rules_exit(net);
1338 	rtnl_unlock();
1339 #endif
1340 ip6mr_rules_fail:
1341 	ip6mr_notifier_exit(net);
1342 	return err;
1343 }
1344 
1345 static void __net_exit ip6mr_net_exit(struct net *net)
1346 {
1347 #ifdef CONFIG_PROC_FS
1348 	remove_proc_entry("ip6_mr_cache", net->proc_net);
1349 	remove_proc_entry("ip6_mr_vif", net->proc_net);
1350 #endif
1351 	ip6mr_notifier_exit(net);
1352 }
1353 
1354 static void __net_exit ip6mr_net_exit_batch(struct list_head *net_list)
1355 {
1356 	struct net *net;
1357 
1358 	rtnl_lock();
1359 	list_for_each_entry(net, net_list, exit_list)
1360 		ip6mr_rules_exit(net);
1361 	rtnl_unlock();
1362 }
1363 
1364 static struct pernet_operations ip6mr_net_ops = {
1365 	.init = ip6mr_net_init,
1366 	.exit = ip6mr_net_exit,
1367 	.exit_batch = ip6mr_net_exit_batch,
1368 };
1369 
1370 int __init ip6_mr_init(void)
1371 {
1372 	int err;
1373 
1374 	mrt_cachep = KMEM_CACHE(mfc6_cache, SLAB_HWCACHE_ALIGN);
1375 	if (!mrt_cachep)
1376 		return -ENOMEM;
1377 
1378 	err = register_pernet_subsys(&ip6mr_net_ops);
1379 	if (err)
1380 		goto reg_pernet_fail;
1381 
1382 	err = register_netdevice_notifier(&ip6_mr_notifier);
1383 	if (err)
1384 		goto reg_notif_fail;
1385 #ifdef CONFIG_IPV6_PIMSM_V2
1386 	if (inet6_add_protocol(&pim6_protocol, IPPROTO_PIM) < 0) {
1387 		pr_err("%s: can't add PIM protocol\n", __func__);
1388 		err = -EAGAIN;
1389 		goto add_proto_fail;
1390 	}
1391 #endif
1392 	err = rtnl_register_module(THIS_MODULE, RTNL_FAMILY_IP6MR, RTM_GETROUTE,
1393 				   ip6mr_rtm_getroute, ip6mr_rtm_dumproute, 0);
1394 	if (err == 0)
1395 		return 0;
1396 
1397 #ifdef CONFIG_IPV6_PIMSM_V2
1398 	inet6_del_protocol(&pim6_protocol, IPPROTO_PIM);
1399 add_proto_fail:
1400 	unregister_netdevice_notifier(&ip6_mr_notifier);
1401 #endif
1402 reg_notif_fail:
1403 	unregister_pernet_subsys(&ip6mr_net_ops);
1404 reg_pernet_fail:
1405 	kmem_cache_destroy(mrt_cachep);
1406 	return err;
1407 }
1408 
1409 void ip6_mr_cleanup(void)
1410 {
1411 	rtnl_unregister(RTNL_FAMILY_IP6MR, RTM_GETROUTE);
1412 #ifdef CONFIG_IPV6_PIMSM_V2
1413 	inet6_del_protocol(&pim6_protocol, IPPROTO_PIM);
1414 #endif
1415 	unregister_netdevice_notifier(&ip6_mr_notifier);
1416 	unregister_pernet_subsys(&ip6mr_net_ops);
1417 	kmem_cache_destroy(mrt_cachep);
1418 }
1419 
1420 static int ip6mr_mfc_add(struct net *net, struct mr_table *mrt,
1421 			 struct mf6cctl *mfc, int mrtsock, int parent)
1422 {
1423 	unsigned char ttls[MAXMIFS];
1424 	struct mfc6_cache *uc, *c;
1425 	struct mr_mfc *_uc;
1426 	bool found;
1427 	int i, err;
1428 
1429 	if (mfc->mf6cc_parent >= MAXMIFS)
1430 		return -ENFILE;
1431 
1432 	memset(ttls, 255, MAXMIFS);
1433 	for (i = 0; i < MAXMIFS; i++) {
1434 		if (IF_ISSET(i, &mfc->mf6cc_ifset))
1435 			ttls[i] = 1;
1436 	}
1437 
1438 	/* The entries are added/deleted only under RTNL */
1439 	rcu_read_lock();
1440 	c = ip6mr_cache_find_parent(mrt, &mfc->mf6cc_origin.sin6_addr,
1441 				    &mfc->mf6cc_mcastgrp.sin6_addr, parent);
1442 	rcu_read_unlock();
1443 	if (c) {
1444 		spin_lock(&mrt_lock);
1445 		c->_c.mfc_parent = mfc->mf6cc_parent;
1446 		ip6mr_update_thresholds(mrt, &c->_c, ttls);
1447 		if (!mrtsock)
1448 			c->_c.mfc_flags |= MFC_STATIC;
1449 		spin_unlock(&mrt_lock);
1450 		call_ip6mr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE,
1451 					       c, mrt->id);
1452 		mr6_netlink_event(mrt, c, RTM_NEWROUTE);
1453 		return 0;
1454 	}
1455 
1456 	if (!ipv6_addr_any(&mfc->mf6cc_mcastgrp.sin6_addr) &&
1457 	    !ipv6_addr_is_multicast(&mfc->mf6cc_mcastgrp.sin6_addr))
1458 		return -EINVAL;
1459 
1460 	c = ip6mr_cache_alloc();
1461 	if (!c)
1462 		return -ENOMEM;
1463 
1464 	c->mf6c_origin = mfc->mf6cc_origin.sin6_addr;
1465 	c->mf6c_mcastgrp = mfc->mf6cc_mcastgrp.sin6_addr;
1466 	c->_c.mfc_parent = mfc->mf6cc_parent;
1467 	ip6mr_update_thresholds(mrt, &c->_c, ttls);
1468 	if (!mrtsock)
1469 		c->_c.mfc_flags |= MFC_STATIC;
1470 
1471 	err = rhltable_insert_key(&mrt->mfc_hash, &c->cmparg, &c->_c.mnode,
1472 				  ip6mr_rht_params);
1473 	if (err) {
1474 		pr_err("ip6mr: rhtable insert error %d\n", err);
1475 		ip6mr_cache_free(c);
1476 		return err;
1477 	}
1478 	list_add_tail_rcu(&c->_c.list, &mrt->mfc_cache_list);
1479 
1480 	/* Check to see if we resolved a queued list. If so we
1481 	 * need to send on the frames and tidy up.
1482 	 */
1483 	found = false;
1484 	spin_lock_bh(&mfc_unres_lock);
1485 	list_for_each_entry(_uc, &mrt->mfc_unres_queue, list) {
1486 		uc = (struct mfc6_cache *)_uc;
1487 		if (ipv6_addr_equal(&uc->mf6c_origin, &c->mf6c_origin) &&
1488 		    ipv6_addr_equal(&uc->mf6c_mcastgrp, &c->mf6c_mcastgrp)) {
1489 			list_del(&_uc->list);
1490 			atomic_dec(&mrt->cache_resolve_queue_len);
1491 			found = true;
1492 			break;
1493 		}
1494 	}
1495 	if (list_empty(&mrt->mfc_unres_queue))
1496 		del_timer(&mrt->ipmr_expire_timer);
1497 	spin_unlock_bh(&mfc_unres_lock);
1498 
1499 	if (found) {
1500 		ip6mr_cache_resolve(net, mrt, uc, c);
1501 		ip6mr_cache_free(uc);
1502 	}
1503 	call_ip6mr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_ADD,
1504 				       c, mrt->id);
1505 	mr6_netlink_event(mrt, c, RTM_NEWROUTE);
1506 	return 0;
1507 }
1508 
1509 /*
1510  *	Close the multicast socket, and clear the vif tables etc
1511  */
1512 
1513 static void mroute_clean_tables(struct mr_table *mrt, int flags)
1514 {
1515 	struct mr_mfc *c, *tmp;
1516 	LIST_HEAD(list);
1517 	int i;
1518 
1519 	/* Shut down all active vif entries */
1520 	if (flags & (MRT6_FLUSH_MIFS | MRT6_FLUSH_MIFS_STATIC)) {
1521 		for (i = 0; i < mrt->maxvif; i++) {
1522 			if (((mrt->vif_table[i].flags & VIFF_STATIC) &&
1523 			     !(flags & MRT6_FLUSH_MIFS_STATIC)) ||
1524 			    (!(mrt->vif_table[i].flags & VIFF_STATIC) && !(flags & MRT6_FLUSH_MIFS)))
1525 				continue;
1526 			mif6_delete(mrt, i, 0, &list);
1527 		}
1528 		unregister_netdevice_many(&list);
1529 	}
1530 
1531 	/* Wipe the cache */
1532 	if (flags & (MRT6_FLUSH_MFC | MRT6_FLUSH_MFC_STATIC)) {
1533 		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
1534 			if (((c->mfc_flags & MFC_STATIC) && !(flags & MRT6_FLUSH_MFC_STATIC)) ||
1535 			    (!(c->mfc_flags & MFC_STATIC) && !(flags & MRT6_FLUSH_MFC)))
1536 				continue;
1537 			rhltable_remove(&mrt->mfc_hash, &c->mnode, ip6mr_rht_params);
1538 			list_del_rcu(&c->list);
1539 			call_ip6mr_mfc_entry_notifiers(read_pnet(&mrt->net),
1540 						       FIB_EVENT_ENTRY_DEL,
1541 						       (struct mfc6_cache *)c, mrt->id);
1542 			mr6_netlink_event(mrt, (struct mfc6_cache *)c, RTM_DELROUTE);
1543 			mr_cache_put(c);
1544 		}
1545 	}
1546 
1547 	if (flags & MRT6_FLUSH_MFC) {
1548 		if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1549 			spin_lock_bh(&mfc_unres_lock);
1550 			list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
1551 				list_del(&c->list);
1552 				mr6_netlink_event(mrt, (struct mfc6_cache *)c,
1553 						  RTM_DELROUTE);
1554 				ip6mr_destroy_unres(mrt, (struct mfc6_cache *)c);
1555 			}
1556 			spin_unlock_bh(&mfc_unres_lock);
1557 		}
1558 	}
1559 }
1560 
1561 static int ip6mr_sk_init(struct mr_table *mrt, struct sock *sk)
1562 {
1563 	int err = 0;
1564 	struct net *net = sock_net(sk);
1565 
1566 	rtnl_lock();
1567 	spin_lock(&mrt_lock);
1568 	if (rtnl_dereference(mrt->mroute_sk)) {
1569 		err = -EADDRINUSE;
1570 	} else {
1571 		rcu_assign_pointer(mrt->mroute_sk, sk);
1572 		sock_set_flag(sk, SOCK_RCU_FREE);
1573 		atomic_inc(&net->ipv6.devconf_all->mc_forwarding);
1574 	}
1575 	spin_unlock(&mrt_lock);
1576 
1577 	if (!err)
1578 		inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
1579 					     NETCONFA_MC_FORWARDING,
1580 					     NETCONFA_IFINDEX_ALL,
1581 					     net->ipv6.devconf_all);
1582 	rtnl_unlock();
1583 
1584 	return err;
1585 }
1586 
1587 int ip6mr_sk_done(struct sock *sk)
1588 {
1589 	struct net *net = sock_net(sk);
1590 	struct ipv6_devconf *devconf;
1591 	struct mr_table *mrt;
1592 	int err = -EACCES;
1593 
1594 	if (sk->sk_type != SOCK_RAW ||
1595 	    inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
1596 		return err;
1597 
1598 	devconf = net->ipv6.devconf_all;
1599 	if (!devconf || !atomic_read(&devconf->mc_forwarding))
1600 		return err;
1601 
1602 	rtnl_lock();
1603 	ip6mr_for_each_table(mrt, net) {
1604 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1605 			spin_lock(&mrt_lock);
1606 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1607 			/* Note that mroute_sk had SOCK_RCU_FREE set,
1608 			 * so the RCU grace period before sk freeing
1609 			 * is guaranteed by sk_destruct()
1610 			 */
1611 			atomic_dec(&devconf->mc_forwarding);
1612 			spin_unlock(&mrt_lock);
1613 			inet6_netconf_notify_devconf(net, RTM_NEWNETCONF,
1614 						     NETCONFA_MC_FORWARDING,
1615 						     NETCONFA_IFINDEX_ALL,
1616 						     net->ipv6.devconf_all);
1617 
1618 			mroute_clean_tables(mrt, MRT6_FLUSH_MIFS | MRT6_FLUSH_MFC);
1619 			err = 0;
1620 			break;
1621 		}
1622 	}
1623 	rtnl_unlock();
1624 
1625 	return err;
1626 }
1627 
1628 bool mroute6_is_socket(struct net *net, struct sk_buff *skb)
1629 {
1630 	struct mr_table *mrt;
1631 	struct flowi6 fl6 = {
1632 		.flowi6_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
1633 		.flowi6_oif	= skb->dev->ifindex,
1634 		.flowi6_mark	= skb->mark,
1635 	};
1636 
1637 	if (ip6mr_fib_lookup(net, &fl6, &mrt) < 0)
1638 		return NULL;
1639 
1640 	return rcu_access_pointer(mrt->mroute_sk);
1641 }
1642 EXPORT_SYMBOL(mroute6_is_socket);
1643 
1644 /*
1645  *	Socket options and virtual interface manipulation. The whole
1646  *	virtual interface system is a complete heap, but unfortunately
1647  *	that's how BSD mrouted happens to think. Maybe one day with a proper
1648  *	MOSPF/PIM router set up we can clean this up.
1649  */
1650 
1651 int ip6_mroute_setsockopt(struct sock *sk, int optname, sockptr_t optval,
1652 			  unsigned int optlen)
1653 {
1654 	int ret, parent = 0;
1655 	struct mif6ctl vif;
1656 	struct mf6cctl mfc;
1657 	mifi_t mifi;
1658 	struct net *net = sock_net(sk);
1659 	struct mr_table *mrt;
1660 
1661 	if (sk->sk_type != SOCK_RAW ||
1662 	    inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
1663 		return -EOPNOTSUPP;
1664 
1665 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
1666 	if (!mrt)
1667 		return -ENOENT;
1668 
1669 	if (optname != MRT6_INIT) {
1670 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1671 		    !ns_capable(net->user_ns, CAP_NET_ADMIN))
1672 			return -EACCES;
1673 	}
1674 
1675 	switch (optname) {
1676 	case MRT6_INIT:
1677 		if (optlen < sizeof(int))
1678 			return -EINVAL;
1679 
1680 		return ip6mr_sk_init(mrt, sk);
1681 
1682 	case MRT6_DONE:
1683 		return ip6mr_sk_done(sk);
1684 
1685 	case MRT6_ADD_MIF:
1686 		if (optlen < sizeof(vif))
1687 			return -EINVAL;
1688 		if (copy_from_sockptr(&vif, optval, sizeof(vif)))
1689 			return -EFAULT;
1690 		if (vif.mif6c_mifi >= MAXMIFS)
1691 			return -ENFILE;
1692 		rtnl_lock();
1693 		ret = mif6_add(net, mrt, &vif,
1694 			       sk == rtnl_dereference(mrt->mroute_sk));
1695 		rtnl_unlock();
1696 		return ret;
1697 
1698 	case MRT6_DEL_MIF:
1699 		if (optlen < sizeof(mifi_t))
1700 			return -EINVAL;
1701 		if (copy_from_sockptr(&mifi, optval, sizeof(mifi_t)))
1702 			return -EFAULT;
1703 		rtnl_lock();
1704 		ret = mif6_delete(mrt, mifi, 0, NULL);
1705 		rtnl_unlock();
1706 		return ret;
1707 
1708 	/*
1709 	 *	Manipulate the forwarding caches. These live
1710 	 *	in a sort of kernel/user symbiosis.
1711 	 */
1712 	case MRT6_ADD_MFC:
1713 	case MRT6_DEL_MFC:
1714 		parent = -1;
1715 		fallthrough;
1716 	case MRT6_ADD_MFC_PROXY:
1717 	case MRT6_DEL_MFC_PROXY:
1718 		if (optlen < sizeof(mfc))
1719 			return -EINVAL;
1720 		if (copy_from_sockptr(&mfc, optval, sizeof(mfc)))
1721 			return -EFAULT;
1722 		if (parent == 0)
1723 			parent = mfc.mf6cc_parent;
1724 		rtnl_lock();
1725 		if (optname == MRT6_DEL_MFC || optname == MRT6_DEL_MFC_PROXY)
1726 			ret = ip6mr_mfc_delete(mrt, &mfc, parent);
1727 		else
1728 			ret = ip6mr_mfc_add(net, mrt, &mfc,
1729 					    sk ==
1730 					    rtnl_dereference(mrt->mroute_sk),
1731 					    parent);
1732 		rtnl_unlock();
1733 		return ret;
1734 
1735 	case MRT6_FLUSH:
1736 	{
1737 		int flags;
1738 
1739 		if (optlen != sizeof(flags))
1740 			return -EINVAL;
1741 		if (copy_from_sockptr(&flags, optval, sizeof(flags)))
1742 			return -EFAULT;
1743 		rtnl_lock();
1744 		mroute_clean_tables(mrt, flags);
1745 		rtnl_unlock();
1746 		return 0;
1747 	}
1748 
1749 	/*
1750 	 *	Control PIM assert (to activate pim will activate assert)
1751 	 */
1752 	case MRT6_ASSERT:
1753 	{
1754 		int v;
1755 
1756 		if (optlen != sizeof(v))
1757 			return -EINVAL;
1758 		if (copy_from_sockptr(&v, optval, sizeof(v)))
1759 			return -EFAULT;
1760 		mrt->mroute_do_assert = v;
1761 		return 0;
1762 	}
1763 
1764 #ifdef CONFIG_IPV6_PIMSM_V2
1765 	case MRT6_PIM:
1766 	{
1767 		bool do_wrmifwhole;
1768 		int v;
1769 
1770 		if (optlen != sizeof(v))
1771 			return -EINVAL;
1772 		if (copy_from_sockptr(&v, optval, sizeof(v)))
1773 			return -EFAULT;
1774 
1775 		do_wrmifwhole = (v == MRT6MSG_WRMIFWHOLE);
1776 		v = !!v;
1777 		rtnl_lock();
1778 		ret = 0;
1779 		if (v != mrt->mroute_do_pim) {
1780 			mrt->mroute_do_pim = v;
1781 			mrt->mroute_do_assert = v;
1782 			mrt->mroute_do_wrvifwhole = do_wrmifwhole;
1783 		}
1784 		rtnl_unlock();
1785 		return ret;
1786 	}
1787 
1788 #endif
1789 #ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
1790 	case MRT6_TABLE:
1791 	{
1792 		u32 v;
1793 
1794 		if (optlen != sizeof(u32))
1795 			return -EINVAL;
1796 		if (copy_from_sockptr(&v, optval, sizeof(v)))
1797 			return -EFAULT;
1798 		/* "pim6reg%u" should not exceed 16 bytes (IFNAMSIZ) */
1799 		if (v != RT_TABLE_DEFAULT && v >= 100000000)
1800 			return -EINVAL;
1801 		if (sk == rcu_access_pointer(mrt->mroute_sk))
1802 			return -EBUSY;
1803 
1804 		rtnl_lock();
1805 		ret = 0;
1806 		mrt = ip6mr_new_table(net, v);
1807 		if (IS_ERR(mrt))
1808 			ret = PTR_ERR(mrt);
1809 		else
1810 			raw6_sk(sk)->ip6mr_table = v;
1811 		rtnl_unlock();
1812 		return ret;
1813 	}
1814 #endif
1815 	/*
1816 	 *	Spurious command, or MRT6_VERSION which you cannot
1817 	 *	set.
1818 	 */
1819 	default:
1820 		return -ENOPROTOOPT;
1821 	}
1822 }
1823 
1824 /*
1825  *	Getsock opt support for the multicast routing system.
1826  */
1827 
1828 int ip6_mroute_getsockopt(struct sock *sk, int optname, sockptr_t optval,
1829 			  sockptr_t optlen)
1830 {
1831 	int olr;
1832 	int val;
1833 	struct net *net = sock_net(sk);
1834 	struct mr_table *mrt;
1835 
1836 	if (sk->sk_type != SOCK_RAW ||
1837 	    inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
1838 		return -EOPNOTSUPP;
1839 
1840 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
1841 	if (!mrt)
1842 		return -ENOENT;
1843 
1844 	switch (optname) {
1845 	case MRT6_VERSION:
1846 		val = 0x0305;
1847 		break;
1848 #ifdef CONFIG_IPV6_PIMSM_V2
1849 	case MRT6_PIM:
1850 		val = mrt->mroute_do_pim;
1851 		break;
1852 #endif
1853 	case MRT6_ASSERT:
1854 		val = mrt->mroute_do_assert;
1855 		break;
1856 	default:
1857 		return -ENOPROTOOPT;
1858 	}
1859 
1860 	if (copy_from_sockptr(&olr, optlen, sizeof(int)))
1861 		return -EFAULT;
1862 
1863 	olr = min_t(int, olr, sizeof(int));
1864 	if (olr < 0)
1865 		return -EINVAL;
1866 
1867 	if (copy_to_sockptr(optlen, &olr, sizeof(int)))
1868 		return -EFAULT;
1869 	if (copy_to_sockptr(optval, &val, olr))
1870 		return -EFAULT;
1871 	return 0;
1872 }
1873 
1874 /*
1875  *	The IP multicast ioctl support routines.
1876  */
1877 int ip6mr_ioctl(struct sock *sk, int cmd, void *arg)
1878 {
1879 	struct sioc_sg_req6 *sr;
1880 	struct sioc_mif_req6 *vr;
1881 	struct vif_device *vif;
1882 	struct mfc6_cache *c;
1883 	struct net *net = sock_net(sk);
1884 	struct mr_table *mrt;
1885 
1886 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
1887 	if (!mrt)
1888 		return -ENOENT;
1889 
1890 	switch (cmd) {
1891 	case SIOCGETMIFCNT_IN6:
1892 		vr = (struct sioc_mif_req6 *)arg;
1893 		if (vr->mifi >= mrt->maxvif)
1894 			return -EINVAL;
1895 		vr->mifi = array_index_nospec(vr->mifi, mrt->maxvif);
1896 		rcu_read_lock();
1897 		vif = &mrt->vif_table[vr->mifi];
1898 		if (VIF_EXISTS(mrt, vr->mifi)) {
1899 			vr->icount = READ_ONCE(vif->pkt_in);
1900 			vr->ocount = READ_ONCE(vif->pkt_out);
1901 			vr->ibytes = READ_ONCE(vif->bytes_in);
1902 			vr->obytes = READ_ONCE(vif->bytes_out);
1903 			rcu_read_unlock();
1904 			return 0;
1905 		}
1906 		rcu_read_unlock();
1907 		return -EADDRNOTAVAIL;
1908 	case SIOCGETSGCNT_IN6:
1909 		sr = (struct sioc_sg_req6 *)arg;
1910 
1911 		rcu_read_lock();
1912 		c = ip6mr_cache_find(mrt, &sr->src.sin6_addr,
1913 				     &sr->grp.sin6_addr);
1914 		if (c) {
1915 			sr->pktcnt = c->_c.mfc_un.res.pkt;
1916 			sr->bytecnt = c->_c.mfc_un.res.bytes;
1917 			sr->wrong_if = c->_c.mfc_un.res.wrong_if;
1918 			rcu_read_unlock();
1919 			return 0;
1920 		}
1921 		rcu_read_unlock();
1922 		return -EADDRNOTAVAIL;
1923 	default:
1924 		return -ENOIOCTLCMD;
1925 	}
1926 }
1927 
1928 #ifdef CONFIG_COMPAT
1929 struct compat_sioc_sg_req6 {
1930 	struct sockaddr_in6 src;
1931 	struct sockaddr_in6 grp;
1932 	compat_ulong_t pktcnt;
1933 	compat_ulong_t bytecnt;
1934 	compat_ulong_t wrong_if;
1935 };
1936 
1937 struct compat_sioc_mif_req6 {
1938 	mifi_t	mifi;
1939 	compat_ulong_t icount;
1940 	compat_ulong_t ocount;
1941 	compat_ulong_t ibytes;
1942 	compat_ulong_t obytes;
1943 };
1944 
1945 int ip6mr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1946 {
1947 	struct compat_sioc_sg_req6 sr;
1948 	struct compat_sioc_mif_req6 vr;
1949 	struct vif_device *vif;
1950 	struct mfc6_cache *c;
1951 	struct net *net = sock_net(sk);
1952 	struct mr_table *mrt;
1953 
1954 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
1955 	if (!mrt)
1956 		return -ENOENT;
1957 
1958 	switch (cmd) {
1959 	case SIOCGETMIFCNT_IN6:
1960 		if (copy_from_user(&vr, arg, sizeof(vr)))
1961 			return -EFAULT;
1962 		if (vr.mifi >= mrt->maxvif)
1963 			return -EINVAL;
1964 		vr.mifi = array_index_nospec(vr.mifi, mrt->maxvif);
1965 		rcu_read_lock();
1966 		vif = &mrt->vif_table[vr.mifi];
1967 		if (VIF_EXISTS(mrt, vr.mifi)) {
1968 			vr.icount = READ_ONCE(vif->pkt_in);
1969 			vr.ocount = READ_ONCE(vif->pkt_out);
1970 			vr.ibytes = READ_ONCE(vif->bytes_in);
1971 			vr.obytes = READ_ONCE(vif->bytes_out);
1972 			rcu_read_unlock();
1973 
1974 			if (copy_to_user(arg, &vr, sizeof(vr)))
1975 				return -EFAULT;
1976 			return 0;
1977 		}
1978 		rcu_read_unlock();
1979 		return -EADDRNOTAVAIL;
1980 	case SIOCGETSGCNT_IN6:
1981 		if (copy_from_user(&sr, arg, sizeof(sr)))
1982 			return -EFAULT;
1983 
1984 		rcu_read_lock();
1985 		c = ip6mr_cache_find(mrt, &sr.src.sin6_addr, &sr.grp.sin6_addr);
1986 		if (c) {
1987 			sr.pktcnt = c->_c.mfc_un.res.pkt;
1988 			sr.bytecnt = c->_c.mfc_un.res.bytes;
1989 			sr.wrong_if = c->_c.mfc_un.res.wrong_if;
1990 			rcu_read_unlock();
1991 
1992 			if (copy_to_user(arg, &sr, sizeof(sr)))
1993 				return -EFAULT;
1994 			return 0;
1995 		}
1996 		rcu_read_unlock();
1997 		return -EADDRNOTAVAIL;
1998 	default:
1999 		return -ENOIOCTLCMD;
2000 	}
2001 }
2002 #endif
2003 
2004 static inline int ip6mr_forward2_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
2005 {
2006 	IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
2007 		      IPSTATS_MIB_OUTFORWDATAGRAMS);
2008 	return dst_output(net, sk, skb);
2009 }
2010 
2011 /*
2012  *	Processing handlers for ip6mr_forward
2013  */
2014 
2015 static int ip6mr_forward2(struct net *net, struct mr_table *mrt,
2016 			  struct sk_buff *skb, int vifi)
2017 {
2018 	struct vif_device *vif = &mrt->vif_table[vifi];
2019 	struct net_device *vif_dev;
2020 	struct ipv6hdr *ipv6h;
2021 	struct dst_entry *dst;
2022 	struct flowi6 fl6;
2023 
2024 	vif_dev = vif_dev_read(vif);
2025 	if (!vif_dev)
2026 		goto out_free;
2027 
2028 #ifdef CONFIG_IPV6_PIMSM_V2
2029 	if (vif->flags & MIFF_REGISTER) {
2030 		WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
2031 		WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len);
2032 		DEV_STATS_ADD(vif_dev, tx_bytes, skb->len);
2033 		DEV_STATS_INC(vif_dev, tx_packets);
2034 		ip6mr_cache_report(mrt, skb, vifi, MRT6MSG_WHOLEPKT);
2035 		goto out_free;
2036 	}
2037 #endif
2038 
2039 	ipv6h = ipv6_hdr(skb);
2040 
2041 	fl6 = (struct flowi6) {
2042 		.flowi6_oif = vif->link,
2043 		.daddr = ipv6h->daddr,
2044 	};
2045 
2046 	dst = ip6_route_output(net, NULL, &fl6);
2047 	if (dst->error) {
2048 		dst_release(dst);
2049 		goto out_free;
2050 	}
2051 
2052 	skb_dst_drop(skb);
2053 	skb_dst_set(skb, dst);
2054 
2055 	/*
2056 	 * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
2057 	 * not only before forwarding, but after forwarding on all output
2058 	 * interfaces. It is clear, if mrouter runs a multicasting
2059 	 * program, it should receive packets not depending to what interface
2060 	 * program is joined.
2061 	 * If we will not make it, the program will have to join on all
2062 	 * interfaces. On the other hand, multihoming host (or router, but
2063 	 * not mrouter) cannot join to more than one interface - it will
2064 	 * result in receiving multiple packets.
2065 	 */
2066 	skb->dev = vif_dev;
2067 	WRITE_ONCE(vif->pkt_out, vif->pkt_out + 1);
2068 	WRITE_ONCE(vif->bytes_out, vif->bytes_out + skb->len);
2069 
2070 	/* We are about to write */
2071 	/* XXX: extension headers? */
2072 	if (skb_cow(skb, sizeof(*ipv6h) + LL_RESERVED_SPACE(vif_dev)))
2073 		goto out_free;
2074 
2075 	ipv6h = ipv6_hdr(skb);
2076 	ipv6h->hop_limit--;
2077 
2078 	IP6CB(skb)->flags |= IP6SKB_FORWARDED;
2079 
2080 	return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD,
2081 		       net, NULL, skb, skb->dev, vif_dev,
2082 		       ip6mr_forward2_finish);
2083 
2084 out_free:
2085 	kfree_skb(skb);
2086 	return 0;
2087 }
2088 
2089 /* Called with rcu_read_lock() */
2090 static int ip6mr_find_vif(struct mr_table *mrt, struct net_device *dev)
2091 {
2092 	int ct;
2093 
2094 	/* Pairs with WRITE_ONCE() in mif6_delete()/mif6_add() */
2095 	for (ct = READ_ONCE(mrt->maxvif) - 1; ct >= 0; ct--) {
2096 		if (rcu_access_pointer(mrt->vif_table[ct].dev) == dev)
2097 			break;
2098 	}
2099 	return ct;
2100 }
2101 
2102 /* Called under rcu_read_lock() */
2103 static void ip6_mr_forward(struct net *net, struct mr_table *mrt,
2104 			   struct net_device *dev, struct sk_buff *skb,
2105 			   struct mfc6_cache *c)
2106 {
2107 	int psend = -1;
2108 	int vif, ct;
2109 	int true_vifi = ip6mr_find_vif(mrt, dev);
2110 
2111 	vif = c->_c.mfc_parent;
2112 	c->_c.mfc_un.res.pkt++;
2113 	c->_c.mfc_un.res.bytes += skb->len;
2114 	c->_c.mfc_un.res.lastuse = jiffies;
2115 
2116 	if (ipv6_addr_any(&c->mf6c_origin) && true_vifi >= 0) {
2117 		struct mfc6_cache *cache_proxy;
2118 
2119 		/* For an (*,G) entry, we only check that the incoming
2120 		 * interface is part of the static tree.
2121 		 */
2122 		cache_proxy = mr_mfc_find_any_parent(mrt, vif);
2123 		if (cache_proxy &&
2124 		    cache_proxy->_c.mfc_un.res.ttls[true_vifi] < 255)
2125 			goto forward;
2126 	}
2127 
2128 	/*
2129 	 * Wrong interface: drop packet and (maybe) send PIM assert.
2130 	 */
2131 	if (rcu_access_pointer(mrt->vif_table[vif].dev) != dev) {
2132 		c->_c.mfc_un.res.wrong_if++;
2133 
2134 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
2135 		    /* pimsm uses asserts, when switching from RPT to SPT,
2136 		       so that we cannot check that packet arrived on an oif.
2137 		       It is bad, but otherwise we would need to move pretty
2138 		       large chunk of pimd to kernel. Ough... --ANK
2139 		     */
2140 		    (mrt->mroute_do_pim ||
2141 		     c->_c.mfc_un.res.ttls[true_vifi] < 255) &&
2142 		    time_after(jiffies,
2143 			       c->_c.mfc_un.res.last_assert +
2144 			       MFC_ASSERT_THRESH)) {
2145 			c->_c.mfc_un.res.last_assert = jiffies;
2146 			ip6mr_cache_report(mrt, skb, true_vifi, MRT6MSG_WRONGMIF);
2147 			if (mrt->mroute_do_wrvifwhole)
2148 				ip6mr_cache_report(mrt, skb, true_vifi,
2149 						   MRT6MSG_WRMIFWHOLE);
2150 		}
2151 		goto dont_forward;
2152 	}
2153 
2154 forward:
2155 	WRITE_ONCE(mrt->vif_table[vif].pkt_in,
2156 		   mrt->vif_table[vif].pkt_in + 1);
2157 	WRITE_ONCE(mrt->vif_table[vif].bytes_in,
2158 		   mrt->vif_table[vif].bytes_in + skb->len);
2159 
2160 	/*
2161 	 *	Forward the frame
2162 	 */
2163 	if (ipv6_addr_any(&c->mf6c_origin) &&
2164 	    ipv6_addr_any(&c->mf6c_mcastgrp)) {
2165 		if (true_vifi >= 0 &&
2166 		    true_vifi != c->_c.mfc_parent &&
2167 		    ipv6_hdr(skb)->hop_limit >
2168 				c->_c.mfc_un.res.ttls[c->_c.mfc_parent]) {
2169 			/* It's an (*,*) entry and the packet is not coming from
2170 			 * the upstream: forward the packet to the upstream
2171 			 * only.
2172 			 */
2173 			psend = c->_c.mfc_parent;
2174 			goto last_forward;
2175 		}
2176 		goto dont_forward;
2177 	}
2178 	for (ct = c->_c.mfc_un.res.maxvif - 1;
2179 	     ct >= c->_c.mfc_un.res.minvif; ct--) {
2180 		/* For (*,G) entry, don't forward to the incoming interface */
2181 		if ((!ipv6_addr_any(&c->mf6c_origin) || ct != true_vifi) &&
2182 		    ipv6_hdr(skb)->hop_limit > c->_c.mfc_un.res.ttls[ct]) {
2183 			if (psend != -1) {
2184 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2185 				if (skb2)
2186 					ip6mr_forward2(net, mrt, skb2, psend);
2187 			}
2188 			psend = ct;
2189 		}
2190 	}
2191 last_forward:
2192 	if (psend != -1) {
2193 		ip6mr_forward2(net, mrt, skb, psend);
2194 		return;
2195 	}
2196 
2197 dont_forward:
2198 	kfree_skb(skb);
2199 }
2200 
2201 
2202 /*
2203  *	Multicast packets for forwarding arrive here
2204  */
2205 
2206 int ip6_mr_input(struct sk_buff *skb)
2207 {
2208 	struct mfc6_cache *cache;
2209 	struct net *net = dev_net(skb->dev);
2210 	struct mr_table *mrt;
2211 	struct flowi6 fl6 = {
2212 		.flowi6_iif	= skb->dev->ifindex,
2213 		.flowi6_mark	= skb->mark,
2214 	};
2215 	int err;
2216 	struct net_device *dev;
2217 
2218 	/* skb->dev passed in is the master dev for vrfs.
2219 	 * Get the proper interface that does have a vif associated with it.
2220 	 */
2221 	dev = skb->dev;
2222 	if (netif_is_l3_master(skb->dev)) {
2223 		dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
2224 		if (!dev) {
2225 			kfree_skb(skb);
2226 			return -ENODEV;
2227 		}
2228 	}
2229 
2230 	err = ip6mr_fib_lookup(net, &fl6, &mrt);
2231 	if (err < 0) {
2232 		kfree_skb(skb);
2233 		return err;
2234 	}
2235 
2236 	cache = ip6mr_cache_find(mrt,
2237 				 &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr);
2238 	if (!cache) {
2239 		int vif = ip6mr_find_vif(mrt, dev);
2240 
2241 		if (vif >= 0)
2242 			cache = ip6mr_cache_find_any(mrt,
2243 						     &ipv6_hdr(skb)->daddr,
2244 						     vif);
2245 	}
2246 
2247 	/*
2248 	 *	No usable cache entry
2249 	 */
2250 	if (!cache) {
2251 		int vif;
2252 
2253 		vif = ip6mr_find_vif(mrt, dev);
2254 		if (vif >= 0) {
2255 			int err = ip6mr_cache_unresolved(mrt, vif, skb, dev);
2256 
2257 			return err;
2258 		}
2259 		kfree_skb(skb);
2260 		return -ENODEV;
2261 	}
2262 
2263 	ip6_mr_forward(net, mrt, dev, skb, cache);
2264 
2265 	return 0;
2266 }
2267 
2268 int ip6mr_get_route(struct net *net, struct sk_buff *skb, struct rtmsg *rtm,
2269 		    u32 portid)
2270 {
2271 	int err;
2272 	struct mr_table *mrt;
2273 	struct mfc6_cache *cache;
2274 	struct rt6_info *rt = dst_rt6_info(skb_dst(skb));
2275 
2276 	mrt = ip6mr_get_table(net, RT6_TABLE_DFLT);
2277 	if (!mrt)
2278 		return -ENOENT;
2279 
2280 	rcu_read_lock();
2281 	cache = ip6mr_cache_find(mrt, &rt->rt6i_src.addr, &rt->rt6i_dst.addr);
2282 	if (!cache && skb->dev) {
2283 		int vif = ip6mr_find_vif(mrt, skb->dev);
2284 
2285 		if (vif >= 0)
2286 			cache = ip6mr_cache_find_any(mrt, &rt->rt6i_dst.addr,
2287 						     vif);
2288 	}
2289 
2290 	if (!cache) {
2291 		struct sk_buff *skb2;
2292 		struct ipv6hdr *iph;
2293 		struct net_device *dev;
2294 		int vif;
2295 
2296 		dev = skb->dev;
2297 		if (!dev || (vif = ip6mr_find_vif(mrt, dev)) < 0) {
2298 			rcu_read_unlock();
2299 			return -ENODEV;
2300 		}
2301 
2302 		/* really correct? */
2303 		skb2 = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
2304 		if (!skb2) {
2305 			rcu_read_unlock();
2306 			return -ENOMEM;
2307 		}
2308 
2309 		NETLINK_CB(skb2).portid = portid;
2310 		skb_reset_transport_header(skb2);
2311 
2312 		skb_put(skb2, sizeof(struct ipv6hdr));
2313 		skb_reset_network_header(skb2);
2314 
2315 		iph = ipv6_hdr(skb2);
2316 		iph->version = 0;
2317 		iph->priority = 0;
2318 		iph->flow_lbl[0] = 0;
2319 		iph->flow_lbl[1] = 0;
2320 		iph->flow_lbl[2] = 0;
2321 		iph->payload_len = 0;
2322 		iph->nexthdr = IPPROTO_NONE;
2323 		iph->hop_limit = 0;
2324 		iph->saddr = rt->rt6i_src.addr;
2325 		iph->daddr = rt->rt6i_dst.addr;
2326 
2327 		err = ip6mr_cache_unresolved(mrt, vif, skb2, dev);
2328 		rcu_read_unlock();
2329 
2330 		return err;
2331 	}
2332 
2333 	err = mr_fill_mroute(mrt, skb, &cache->_c, rtm);
2334 	rcu_read_unlock();
2335 	return err;
2336 }
2337 
2338 static int ip6mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2339 			     u32 portid, u32 seq, struct mfc6_cache *c, int cmd,
2340 			     int flags)
2341 {
2342 	struct nlmsghdr *nlh;
2343 	struct rtmsg *rtm;
2344 	int err;
2345 
2346 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2347 	if (!nlh)
2348 		return -EMSGSIZE;
2349 
2350 	rtm = nlmsg_data(nlh);
2351 	rtm->rtm_family   = RTNL_FAMILY_IP6MR;
2352 	rtm->rtm_dst_len  = 128;
2353 	rtm->rtm_src_len  = 128;
2354 	rtm->rtm_tos      = 0;
2355 	rtm->rtm_table    = mrt->id;
2356 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2357 		goto nla_put_failure;
2358 	rtm->rtm_type = RTN_MULTICAST;
2359 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2360 	if (c->_c.mfc_flags & MFC_STATIC)
2361 		rtm->rtm_protocol = RTPROT_STATIC;
2362 	else
2363 		rtm->rtm_protocol = RTPROT_MROUTED;
2364 	rtm->rtm_flags    = 0;
2365 
2366 	if (nla_put_in6_addr(skb, RTA_SRC, &c->mf6c_origin) ||
2367 	    nla_put_in6_addr(skb, RTA_DST, &c->mf6c_mcastgrp))
2368 		goto nla_put_failure;
2369 	err = mr_fill_mroute(mrt, skb, &c->_c, rtm);
2370 	/* do not break the dump if cache is unresolved */
2371 	if (err < 0 && err != -ENOENT)
2372 		goto nla_put_failure;
2373 
2374 	nlmsg_end(skb, nlh);
2375 	return 0;
2376 
2377 nla_put_failure:
2378 	nlmsg_cancel(skb, nlh);
2379 	return -EMSGSIZE;
2380 }
2381 
2382 static int _ip6mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2383 			      u32 portid, u32 seq, struct mr_mfc *c,
2384 			      int cmd, int flags)
2385 {
2386 	return ip6mr_fill_mroute(mrt, skb, portid, seq, (struct mfc6_cache *)c,
2387 				 cmd, flags);
2388 }
2389 
2390 static int mr6_msgsize(bool unresolved, int maxvif)
2391 {
2392 	size_t len =
2393 		NLMSG_ALIGN(sizeof(struct rtmsg))
2394 		+ nla_total_size(4)	/* RTA_TABLE */
2395 		+ nla_total_size(sizeof(struct in6_addr))	/* RTA_SRC */
2396 		+ nla_total_size(sizeof(struct in6_addr))	/* RTA_DST */
2397 		;
2398 
2399 	if (!unresolved)
2400 		len = len
2401 		      + nla_total_size(4)	/* RTA_IIF */
2402 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2403 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2404 						/* RTA_MFC_STATS */
2405 		      + nla_total_size_64bit(sizeof(struct rta_mfc_stats))
2406 		;
2407 
2408 	return len;
2409 }
2410 
2411 static void mr6_netlink_event(struct mr_table *mrt, struct mfc6_cache *mfc,
2412 			      int cmd)
2413 {
2414 	struct net *net = read_pnet(&mrt->net);
2415 	struct sk_buff *skb;
2416 	int err = -ENOBUFS;
2417 
2418 	skb = nlmsg_new(mr6_msgsize(mfc->_c.mfc_parent >= MAXMIFS, mrt->maxvif),
2419 			GFP_ATOMIC);
2420 	if (!skb)
2421 		goto errout;
2422 
2423 	err = ip6mr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2424 	if (err < 0)
2425 		goto errout;
2426 
2427 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_MROUTE, NULL, GFP_ATOMIC);
2428 	return;
2429 
2430 errout:
2431 	kfree_skb(skb);
2432 	rtnl_set_sk_err(net, RTNLGRP_IPV6_MROUTE, err);
2433 }
2434 
2435 static size_t mrt6msg_netlink_msgsize(size_t payloadlen)
2436 {
2437 	size_t len =
2438 		NLMSG_ALIGN(sizeof(struct rtgenmsg))
2439 		+ nla_total_size(1)	/* IP6MRA_CREPORT_MSGTYPE */
2440 		+ nla_total_size(4)	/* IP6MRA_CREPORT_MIF_ID */
2441 					/* IP6MRA_CREPORT_SRC_ADDR */
2442 		+ nla_total_size(sizeof(struct in6_addr))
2443 					/* IP6MRA_CREPORT_DST_ADDR */
2444 		+ nla_total_size(sizeof(struct in6_addr))
2445 					/* IP6MRA_CREPORT_PKT */
2446 		+ nla_total_size(payloadlen)
2447 		;
2448 
2449 	return len;
2450 }
2451 
2452 static void mrt6msg_netlink_event(const struct mr_table *mrt, struct sk_buff *pkt)
2453 {
2454 	struct net *net = read_pnet(&mrt->net);
2455 	struct nlmsghdr *nlh;
2456 	struct rtgenmsg *rtgenm;
2457 	struct mrt6msg *msg;
2458 	struct sk_buff *skb;
2459 	struct nlattr *nla;
2460 	int payloadlen;
2461 
2462 	payloadlen = pkt->len - sizeof(struct mrt6msg);
2463 	msg = (struct mrt6msg *)skb_transport_header(pkt);
2464 
2465 	skb = nlmsg_new(mrt6msg_netlink_msgsize(payloadlen), GFP_ATOMIC);
2466 	if (!skb)
2467 		goto errout;
2468 
2469 	nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT,
2470 			sizeof(struct rtgenmsg), 0);
2471 	if (!nlh)
2472 		goto errout;
2473 	rtgenm = nlmsg_data(nlh);
2474 	rtgenm->rtgen_family = RTNL_FAMILY_IP6MR;
2475 	if (nla_put_u8(skb, IP6MRA_CREPORT_MSGTYPE, msg->im6_msgtype) ||
2476 	    nla_put_u32(skb, IP6MRA_CREPORT_MIF_ID, msg->im6_mif) ||
2477 	    nla_put_in6_addr(skb, IP6MRA_CREPORT_SRC_ADDR,
2478 			     &msg->im6_src) ||
2479 	    nla_put_in6_addr(skb, IP6MRA_CREPORT_DST_ADDR,
2480 			     &msg->im6_dst))
2481 		goto nla_put_failure;
2482 
2483 	nla = nla_reserve(skb, IP6MRA_CREPORT_PKT, payloadlen);
2484 	if (!nla || skb_copy_bits(pkt, sizeof(struct mrt6msg),
2485 				  nla_data(nla), payloadlen))
2486 		goto nla_put_failure;
2487 
2488 	nlmsg_end(skb, nlh);
2489 
2490 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_MROUTE_R, NULL, GFP_ATOMIC);
2491 	return;
2492 
2493 nla_put_failure:
2494 	nlmsg_cancel(skb, nlh);
2495 errout:
2496 	kfree_skb(skb);
2497 	rtnl_set_sk_err(net, RTNLGRP_IPV6_MROUTE_R, -ENOBUFS);
2498 }
2499 
2500 static const struct nla_policy ip6mr_getroute_policy[RTA_MAX + 1] = {
2501 	[RTA_SRC]		= NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
2502 	[RTA_DST]		= NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
2503 	[RTA_TABLE]		= { .type = NLA_U32 },
2504 };
2505 
2506 static int ip6mr_rtm_valid_getroute_req(struct sk_buff *skb,
2507 					const struct nlmsghdr *nlh,
2508 					struct nlattr **tb,
2509 					struct netlink_ext_ack *extack)
2510 {
2511 	struct rtmsg *rtm;
2512 	int err;
2513 
2514 	err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, ip6mr_getroute_policy,
2515 			  extack);
2516 	if (err)
2517 		return err;
2518 
2519 	rtm = nlmsg_data(nlh);
2520 	if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
2521 	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
2522 	    rtm->rtm_tos || rtm->rtm_table || rtm->rtm_protocol ||
2523 	    rtm->rtm_scope || rtm->rtm_type || rtm->rtm_flags) {
2524 		NL_SET_ERR_MSG_MOD(extack,
2525 				   "Invalid values in header for multicast route get request");
2526 		return -EINVAL;
2527 	}
2528 
2529 	if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
2530 	    (tb[RTA_DST] && !rtm->rtm_dst_len)) {
2531 		NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
2532 		return -EINVAL;
2533 	}
2534 
2535 	return 0;
2536 }
2537 
2538 static int ip6mr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2539 			      struct netlink_ext_ack *extack)
2540 {
2541 	struct net *net = sock_net(in_skb->sk);
2542 	struct in6_addr src = {}, grp = {};
2543 	struct nlattr *tb[RTA_MAX + 1];
2544 	struct mfc6_cache *cache;
2545 	struct mr_table *mrt;
2546 	struct sk_buff *skb;
2547 	u32 tableid;
2548 	int err;
2549 
2550 	err = ip6mr_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
2551 	if (err < 0)
2552 		return err;
2553 
2554 	if (tb[RTA_SRC])
2555 		src = nla_get_in6_addr(tb[RTA_SRC]);
2556 	if (tb[RTA_DST])
2557 		grp = nla_get_in6_addr(tb[RTA_DST]);
2558 	tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0;
2559 
2560 	mrt = ip6mr_get_table(net, tableid ?: RT_TABLE_DEFAULT);
2561 	if (!mrt) {
2562 		NL_SET_ERR_MSG_MOD(extack, "MR table does not exist");
2563 		return -ENOENT;
2564 	}
2565 
2566 	/* entries are added/deleted only under RTNL */
2567 	rcu_read_lock();
2568 	cache = ip6mr_cache_find(mrt, &src, &grp);
2569 	rcu_read_unlock();
2570 	if (!cache) {
2571 		NL_SET_ERR_MSG_MOD(extack, "MR cache entry not found");
2572 		return -ENOENT;
2573 	}
2574 
2575 	skb = nlmsg_new(mr6_msgsize(false, mrt->maxvif), GFP_KERNEL);
2576 	if (!skb)
2577 		return -ENOBUFS;
2578 
2579 	err = ip6mr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid,
2580 				nlh->nlmsg_seq, cache, RTM_NEWROUTE, 0);
2581 	if (err < 0) {
2582 		kfree_skb(skb);
2583 		return err;
2584 	}
2585 
2586 	return rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2587 }
2588 
2589 static int ip6mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2590 {
2591 	const struct nlmsghdr *nlh = cb->nlh;
2592 	struct fib_dump_filter filter = {
2593 		.rtnl_held = true,
2594 	};
2595 	int err;
2596 
2597 	if (cb->strict_check) {
2598 		err = ip_valid_fib_dump_req(sock_net(skb->sk), nlh,
2599 					    &filter, cb);
2600 		if (err < 0)
2601 			return err;
2602 	}
2603 
2604 	if (filter.table_id) {
2605 		struct mr_table *mrt;
2606 
2607 		mrt = ip6mr_get_table(sock_net(skb->sk), filter.table_id);
2608 		if (!mrt) {
2609 			if (rtnl_msg_family(cb->nlh) != RTNL_FAMILY_IP6MR)
2610 				return skb->len;
2611 
2612 			NL_SET_ERR_MSG_MOD(cb->extack, "MR table does not exist");
2613 			return -ENOENT;
2614 		}
2615 		err = mr_table_dump(mrt, skb, cb, _ip6mr_fill_mroute,
2616 				    &mfc_unres_lock, &filter);
2617 		return skb->len ? : err;
2618 	}
2619 
2620 	return mr_rtm_dumproute(skb, cb, ip6mr_mr_table_iter,
2621 				_ip6mr_fill_mroute, &mfc_unres_lock, &filter);
2622 }
2623