xref: /linux/net/ipv6/ip6mr.c (revision 3ce095c16263630dde46d6051854073edaacf3d7)
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 <asm/uaccess.h>
20 #include <linux/types.h>
21 #include <linux/sched.h>
22 #include <linux/errno.h>
23 #include <linux/timer.h>
24 #include <linux/mm.h>
25 #include <linux/kernel.h>
26 #include <linux/fcntl.h>
27 #include <linux/stat.h>
28 #include <linux/socket.h>
29 #include <linux/inet.h>
30 #include <linux/netdevice.h>
31 #include <linux/inetdevice.h>
32 #include <linux/proc_fs.h>
33 #include <linux/seq_file.h>
34 #include <linux/init.h>
35 #include <linux/slab.h>
36 #include <linux/compat.h>
37 #include <net/protocol.h>
38 #include <linux/skbuff.h>
39 #include <net/sock.h>
40 #include <net/raw.h>
41 #include <linux/notifier.h>
42 #include <linux/if_arp.h>
43 #include <net/checksum.h>
44 #include <net/netlink.h>
45 #include <net/fib_rules.h>
46 
47 #include <net/ipv6.h>
48 #include <net/ip6_route.h>
49 #include <linux/mroute6.h>
50 #include <linux/pim.h>
51 #include <net/addrconf.h>
52 #include <linux/netfilter_ipv6.h>
53 #include <linux/export.h>
54 #include <net/ip6_checksum.h>
55 #include <linux/netconf.h>
56 
57 struct mr6_table {
58 	struct list_head	list;
59 	possible_net_t		net;
60 	u32			id;
61 	struct sock		*mroute6_sk;
62 	struct timer_list	ipmr_expire_timer;
63 	struct list_head	mfc6_unres_queue;
64 	struct list_head	mfc6_cache_array[MFC6_LINES];
65 	struct mif_device	vif6_table[MAXMIFS];
66 	int			maxvif;
67 	atomic_t		cache_resolve_queue_len;
68 	bool			mroute_do_assert;
69 	bool			mroute_do_pim;
70 #ifdef CONFIG_IPV6_PIMSM_V2
71 	int			mroute_reg_vif_num;
72 #endif
73 };
74 
75 struct ip6mr_rule {
76 	struct fib_rule		common;
77 };
78 
79 struct ip6mr_result {
80 	struct mr6_table	*mrt;
81 };
82 
83 /* Big lock, protecting vif table, mrt cache and mroute socket state.
84    Note that the changes are semaphored via rtnl_lock.
85  */
86 
87 static DEFINE_RWLOCK(mrt_lock);
88 
89 /*
90  *	Multicast router control variables
91  */
92 
93 #define MIF_EXISTS(_mrt, _idx) ((_mrt)->vif6_table[_idx].dev != NULL)
94 
95 /* Special spinlock for queue of unresolved entries */
96 static DEFINE_SPINLOCK(mfc_unres_lock);
97 
98 /* We return to original Alan's scheme. Hash table of resolved
99    entries is changed only in process context and protected
100    with weak lock mrt_lock. Queue of unresolved entries is protected
101    with strong spinlock mfc_unres_lock.
102 
103    In this case data path is free of exclusive locks at all.
104  */
105 
106 static struct kmem_cache *mrt_cachep __read_mostly;
107 
108 static struct mr6_table *ip6mr_new_table(struct net *net, u32 id);
109 static void ip6mr_free_table(struct mr6_table *mrt);
110 
111 static void ip6_mr_forward(struct net *net, struct mr6_table *mrt,
112 			   struct sk_buff *skb, struct mfc6_cache *cache);
113 static int ip6mr_cache_report(struct mr6_table *mrt, struct sk_buff *pkt,
114 			      mifi_t mifi, int assert);
115 static int __ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb,
116 			       struct mfc6_cache *c, struct rtmsg *rtm);
117 static void mr6_netlink_event(struct mr6_table *mrt, struct mfc6_cache *mfc,
118 			      int cmd);
119 static int ip6mr_rtm_dumproute(struct sk_buff *skb,
120 			       struct netlink_callback *cb);
121 static void mroute_clean_tables(struct mr6_table *mrt);
122 static void ipmr_expire_process(unsigned long arg);
123 
124 #ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
125 #define ip6mr_for_each_table(mrt, net) \
126 	list_for_each_entry_rcu(mrt, &net->ipv6.mr6_tables, list)
127 
128 static struct mr6_table *ip6mr_get_table(struct net *net, u32 id)
129 {
130 	struct mr6_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 mr6_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 	err = fib_rules_lookup(net->ipv6.mr6_rules_ops,
150 			       flowi6_to_flowi(flp6), 0, &arg);
151 	if (err < 0)
152 		return err;
153 	*mrt = res.mrt;
154 	return 0;
155 }
156 
157 static int ip6mr_rule_action(struct fib_rule *rule, struct flowi *flp,
158 			     int flags, struct fib_lookup_arg *arg)
159 {
160 	struct ip6mr_result *res = arg->result;
161 	struct mr6_table *mrt;
162 
163 	switch (rule->action) {
164 	case FR_ACT_TO_TBL:
165 		break;
166 	case FR_ACT_UNREACHABLE:
167 		return -ENETUNREACH;
168 	case FR_ACT_PROHIBIT:
169 		return -EACCES;
170 	case FR_ACT_BLACKHOLE:
171 	default:
172 		return -EINVAL;
173 	}
174 
175 	mrt = ip6mr_get_table(rule->fr_net, rule->table);
176 	if (!mrt)
177 		return -EAGAIN;
178 	res->mrt = mrt;
179 	return 0;
180 }
181 
182 static int ip6mr_rule_match(struct fib_rule *rule, struct flowi *flp, int flags)
183 {
184 	return 1;
185 }
186 
187 static const struct nla_policy ip6mr_rule_policy[FRA_MAX + 1] = {
188 	FRA_GENERIC_POLICY,
189 };
190 
191 static int ip6mr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
192 				struct fib_rule_hdr *frh, struct nlattr **tb)
193 {
194 	return 0;
195 }
196 
197 static int ip6mr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
198 			      struct nlattr **tb)
199 {
200 	return 1;
201 }
202 
203 static int ip6mr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
204 			   struct fib_rule_hdr *frh)
205 {
206 	frh->dst_len = 0;
207 	frh->src_len = 0;
208 	frh->tos     = 0;
209 	return 0;
210 }
211 
212 static const struct fib_rules_ops __net_initconst ip6mr_rules_ops_template = {
213 	.family		= RTNL_FAMILY_IP6MR,
214 	.rule_size	= sizeof(struct ip6mr_rule),
215 	.addr_size	= sizeof(struct in6_addr),
216 	.action		= ip6mr_rule_action,
217 	.match		= ip6mr_rule_match,
218 	.configure	= ip6mr_rule_configure,
219 	.compare	= ip6mr_rule_compare,
220 	.default_pref	= fib_default_rule_pref,
221 	.fill		= ip6mr_rule_fill,
222 	.nlgroup	= RTNLGRP_IPV6_RULE,
223 	.policy		= ip6mr_rule_policy,
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 mr6_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 (!mrt) {
241 		err = -ENOMEM;
242 		goto err1;
243 	}
244 
245 	err = fib_default_rule_add(ops, 0x7fff, RT6_TABLE_DFLT, 0);
246 	if (err < 0)
247 		goto err2;
248 
249 	net->ipv6.mr6_rules_ops = ops;
250 	return 0;
251 
252 err2:
253 	ip6mr_free_table(mrt);
254 err1:
255 	fib_rules_unregister(ops);
256 	return err;
257 }
258 
259 static void __net_exit ip6mr_rules_exit(struct net *net)
260 {
261 	struct mr6_table *mrt, *next;
262 
263 	rtnl_lock();
264 	list_for_each_entry_safe(mrt, next, &net->ipv6.mr6_tables, list) {
265 		list_del(&mrt->list);
266 		ip6mr_free_table(mrt);
267 	}
268 	fib_rules_unregister(net->ipv6.mr6_rules_ops);
269 	rtnl_unlock();
270 }
271 #else
272 #define ip6mr_for_each_table(mrt, net) \
273 	for (mrt = net->ipv6.mrt6; mrt; mrt = NULL)
274 
275 static struct mr6_table *ip6mr_get_table(struct net *net, u32 id)
276 {
277 	return net->ipv6.mrt6;
278 }
279 
280 static int ip6mr_fib_lookup(struct net *net, struct flowi6 *flp6,
281 			    struct mr6_table **mrt)
282 {
283 	*mrt = net->ipv6.mrt6;
284 	return 0;
285 }
286 
287 static int __net_init ip6mr_rules_init(struct net *net)
288 {
289 	net->ipv6.mrt6 = ip6mr_new_table(net, RT6_TABLE_DFLT);
290 	return net->ipv6.mrt6 ? 0 : -ENOMEM;
291 }
292 
293 static void __net_exit ip6mr_rules_exit(struct net *net)
294 {
295 	rtnl_lock();
296 	ip6mr_free_table(net->ipv6.mrt6);
297 	net->ipv6.mrt6 = NULL;
298 	rtnl_unlock();
299 }
300 #endif
301 
302 static struct mr6_table *ip6mr_new_table(struct net *net, u32 id)
303 {
304 	struct mr6_table *mrt;
305 	unsigned int i;
306 
307 	mrt = ip6mr_get_table(net, id);
308 	if (mrt)
309 		return mrt;
310 
311 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
312 	if (!mrt)
313 		return NULL;
314 	mrt->id = id;
315 	write_pnet(&mrt->net, net);
316 
317 	/* Forwarding cache */
318 	for (i = 0; i < MFC6_LINES; i++)
319 		INIT_LIST_HEAD(&mrt->mfc6_cache_array[i]);
320 
321 	INIT_LIST_HEAD(&mrt->mfc6_unres_queue);
322 
323 	setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
324 		    (unsigned long)mrt);
325 
326 #ifdef CONFIG_IPV6_PIMSM_V2
327 	mrt->mroute_reg_vif_num = -1;
328 #endif
329 #ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
330 	list_add_tail_rcu(&mrt->list, &net->ipv6.mr6_tables);
331 #endif
332 	return mrt;
333 }
334 
335 static void ip6mr_free_table(struct mr6_table *mrt)
336 {
337 	del_timer_sync(&mrt->ipmr_expire_timer);
338 	mroute_clean_tables(mrt);
339 	kfree(mrt);
340 }
341 
342 #ifdef CONFIG_PROC_FS
343 
344 struct ipmr_mfc_iter {
345 	struct seq_net_private p;
346 	struct mr6_table *mrt;
347 	struct list_head *cache;
348 	int ct;
349 };
350 
351 
352 static struct mfc6_cache *ipmr_mfc_seq_idx(struct net *net,
353 					   struct ipmr_mfc_iter *it, loff_t pos)
354 {
355 	struct mr6_table *mrt = it->mrt;
356 	struct mfc6_cache *mfc;
357 
358 	read_lock(&mrt_lock);
359 	for (it->ct = 0; it->ct < MFC6_LINES; it->ct++) {
360 		it->cache = &mrt->mfc6_cache_array[it->ct];
361 		list_for_each_entry(mfc, it->cache, list)
362 			if (pos-- == 0)
363 				return mfc;
364 	}
365 	read_unlock(&mrt_lock);
366 
367 	spin_lock_bh(&mfc_unres_lock);
368 	it->cache = &mrt->mfc6_unres_queue;
369 	list_for_each_entry(mfc, it->cache, list)
370 		if (pos-- == 0)
371 			return mfc;
372 	spin_unlock_bh(&mfc_unres_lock);
373 
374 	it->cache = NULL;
375 	return NULL;
376 }
377 
378 /*
379  *	The /proc interfaces to multicast routing /proc/ip6_mr_cache /proc/ip6_mr_vif
380  */
381 
382 struct ipmr_vif_iter {
383 	struct seq_net_private p;
384 	struct mr6_table *mrt;
385 	int ct;
386 };
387 
388 static struct mif_device *ip6mr_vif_seq_idx(struct net *net,
389 					    struct ipmr_vif_iter *iter,
390 					    loff_t pos)
391 {
392 	struct mr6_table *mrt = iter->mrt;
393 
394 	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
395 		if (!MIF_EXISTS(mrt, iter->ct))
396 			continue;
397 		if (pos-- == 0)
398 			return &mrt->vif6_table[iter->ct];
399 	}
400 	return NULL;
401 }
402 
403 static void *ip6mr_vif_seq_start(struct seq_file *seq, loff_t *pos)
404 	__acquires(mrt_lock)
405 {
406 	struct ipmr_vif_iter *iter = seq->private;
407 	struct net *net = seq_file_net(seq);
408 	struct mr6_table *mrt;
409 
410 	mrt = ip6mr_get_table(net, RT6_TABLE_DFLT);
411 	if (!mrt)
412 		return ERR_PTR(-ENOENT);
413 
414 	iter->mrt = mrt;
415 
416 	read_lock(&mrt_lock);
417 	return *pos ? ip6mr_vif_seq_idx(net, seq->private, *pos - 1)
418 		: SEQ_START_TOKEN;
419 }
420 
421 static void *ip6mr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
422 {
423 	struct ipmr_vif_iter *iter = seq->private;
424 	struct net *net = seq_file_net(seq);
425 	struct mr6_table *mrt = iter->mrt;
426 
427 	++*pos;
428 	if (v == SEQ_START_TOKEN)
429 		return ip6mr_vif_seq_idx(net, iter, 0);
430 
431 	while (++iter->ct < mrt->maxvif) {
432 		if (!MIF_EXISTS(mrt, iter->ct))
433 			continue;
434 		return &mrt->vif6_table[iter->ct];
435 	}
436 	return NULL;
437 }
438 
439 static void ip6mr_vif_seq_stop(struct seq_file *seq, void *v)
440 	__releases(mrt_lock)
441 {
442 	read_unlock(&mrt_lock);
443 }
444 
445 static int ip6mr_vif_seq_show(struct seq_file *seq, void *v)
446 {
447 	struct ipmr_vif_iter *iter = seq->private;
448 	struct mr6_table *mrt = iter->mrt;
449 
450 	if (v == SEQ_START_TOKEN) {
451 		seq_puts(seq,
452 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags\n");
453 	} else {
454 		const struct mif_device *vif = v;
455 		const char *name = vif->dev ? vif->dev->name : "none";
456 
457 		seq_printf(seq,
458 			   "%2td %-10s %8ld %7ld  %8ld %7ld %05X\n",
459 			   vif - mrt->vif6_table,
460 			   name, vif->bytes_in, vif->pkt_in,
461 			   vif->bytes_out, vif->pkt_out,
462 			   vif->flags);
463 	}
464 	return 0;
465 }
466 
467 static const struct seq_operations ip6mr_vif_seq_ops = {
468 	.start = ip6mr_vif_seq_start,
469 	.next  = ip6mr_vif_seq_next,
470 	.stop  = ip6mr_vif_seq_stop,
471 	.show  = ip6mr_vif_seq_show,
472 };
473 
474 static int ip6mr_vif_open(struct inode *inode, struct file *file)
475 {
476 	return seq_open_net(inode, file, &ip6mr_vif_seq_ops,
477 			    sizeof(struct ipmr_vif_iter));
478 }
479 
480 static const struct file_operations ip6mr_vif_fops = {
481 	.owner	 = THIS_MODULE,
482 	.open    = ip6mr_vif_open,
483 	.read    = seq_read,
484 	.llseek  = seq_lseek,
485 	.release = seq_release_net,
486 };
487 
488 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
489 {
490 	struct ipmr_mfc_iter *it = seq->private;
491 	struct net *net = seq_file_net(seq);
492 	struct mr6_table *mrt;
493 
494 	mrt = ip6mr_get_table(net, RT6_TABLE_DFLT);
495 	if (!mrt)
496 		return ERR_PTR(-ENOENT);
497 
498 	it->mrt = mrt;
499 	return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
500 		: SEQ_START_TOKEN;
501 }
502 
503 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
504 {
505 	struct mfc6_cache *mfc = v;
506 	struct ipmr_mfc_iter *it = seq->private;
507 	struct net *net = seq_file_net(seq);
508 	struct mr6_table *mrt = it->mrt;
509 
510 	++*pos;
511 
512 	if (v == SEQ_START_TOKEN)
513 		return ipmr_mfc_seq_idx(net, seq->private, 0);
514 
515 	if (mfc->list.next != it->cache)
516 		return list_entry(mfc->list.next, struct mfc6_cache, list);
517 
518 	if (it->cache == &mrt->mfc6_unres_queue)
519 		goto end_of_list;
520 
521 	BUG_ON(it->cache != &mrt->mfc6_cache_array[it->ct]);
522 
523 	while (++it->ct < MFC6_LINES) {
524 		it->cache = &mrt->mfc6_cache_array[it->ct];
525 		if (list_empty(it->cache))
526 			continue;
527 		return list_first_entry(it->cache, struct mfc6_cache, list);
528 	}
529 
530 	/* exhausted cache_array, show unresolved */
531 	read_unlock(&mrt_lock);
532 	it->cache = &mrt->mfc6_unres_queue;
533 	it->ct = 0;
534 
535 	spin_lock_bh(&mfc_unres_lock);
536 	if (!list_empty(it->cache))
537 		return list_first_entry(it->cache, struct mfc6_cache, list);
538 
539  end_of_list:
540 	spin_unlock_bh(&mfc_unres_lock);
541 	it->cache = NULL;
542 
543 	return NULL;
544 }
545 
546 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
547 {
548 	struct ipmr_mfc_iter *it = seq->private;
549 	struct mr6_table *mrt = it->mrt;
550 
551 	if (it->cache == &mrt->mfc6_unres_queue)
552 		spin_unlock_bh(&mfc_unres_lock);
553 	else if (it->cache == mrt->mfc6_cache_array)
554 		read_unlock(&mrt_lock);
555 }
556 
557 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
558 {
559 	int n;
560 
561 	if (v == SEQ_START_TOKEN) {
562 		seq_puts(seq,
563 			 "Group                            "
564 			 "Origin                           "
565 			 "Iif      Pkts  Bytes     Wrong  Oifs\n");
566 	} else {
567 		const struct mfc6_cache *mfc = v;
568 		const struct ipmr_mfc_iter *it = seq->private;
569 		struct mr6_table *mrt = it->mrt;
570 
571 		seq_printf(seq, "%pI6 %pI6 %-3hd",
572 			   &mfc->mf6c_mcastgrp, &mfc->mf6c_origin,
573 			   mfc->mf6c_parent);
574 
575 		if (it->cache != &mrt->mfc6_unres_queue) {
576 			seq_printf(seq, " %8lu %8lu %8lu",
577 				   mfc->mfc_un.res.pkt,
578 				   mfc->mfc_un.res.bytes,
579 				   mfc->mfc_un.res.wrong_if);
580 			for (n = mfc->mfc_un.res.minvif;
581 			     n < mfc->mfc_un.res.maxvif; n++) {
582 				if (MIF_EXISTS(mrt, n) &&
583 				    mfc->mfc_un.res.ttls[n] < 255)
584 					seq_printf(seq,
585 						   " %2d:%-3d",
586 						   n, mfc->mfc_un.res.ttls[n]);
587 			}
588 		} else {
589 			/* unresolved mfc_caches don't contain
590 			 * pkt, bytes and wrong_if values
591 			 */
592 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
593 		}
594 		seq_putc(seq, '\n');
595 	}
596 	return 0;
597 }
598 
599 static const struct seq_operations ipmr_mfc_seq_ops = {
600 	.start = ipmr_mfc_seq_start,
601 	.next  = ipmr_mfc_seq_next,
602 	.stop  = ipmr_mfc_seq_stop,
603 	.show  = ipmr_mfc_seq_show,
604 };
605 
606 static int ipmr_mfc_open(struct inode *inode, struct file *file)
607 {
608 	return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
609 			    sizeof(struct ipmr_mfc_iter));
610 }
611 
612 static const struct file_operations ip6mr_mfc_fops = {
613 	.owner	 = THIS_MODULE,
614 	.open    = ipmr_mfc_open,
615 	.read    = seq_read,
616 	.llseek  = seq_lseek,
617 	.release = seq_release_net,
618 };
619 #endif
620 
621 #ifdef CONFIG_IPV6_PIMSM_V2
622 
623 static int pim6_rcv(struct sk_buff *skb)
624 {
625 	struct pimreghdr *pim;
626 	struct ipv6hdr   *encap;
627 	struct net_device  *reg_dev = NULL;
628 	struct net *net = dev_net(skb->dev);
629 	struct mr6_table *mrt;
630 	struct flowi6 fl6 = {
631 		.flowi6_iif	= skb->dev->ifindex,
632 		.flowi6_mark	= skb->mark,
633 	};
634 	int reg_vif_num;
635 
636 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap)))
637 		goto drop;
638 
639 	pim = (struct pimreghdr *)skb_transport_header(skb);
640 	if (pim->type != ((PIM_VERSION << 4) | PIM_REGISTER) ||
641 	    (pim->flags & PIM_NULL_REGISTER) ||
642 	    (csum_ipv6_magic(&ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
643 			     sizeof(*pim), IPPROTO_PIM,
644 			     csum_partial((void *)pim, sizeof(*pim), 0)) &&
645 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
646 		goto drop;
647 
648 	/* check if the inner packet is destined to mcast group */
649 	encap = (struct ipv6hdr *)(skb_transport_header(skb) +
650 				   sizeof(*pim));
651 
652 	if (!ipv6_addr_is_multicast(&encap->daddr) ||
653 	    encap->payload_len == 0 ||
654 	    ntohs(encap->payload_len) + sizeof(*pim) > skb->len)
655 		goto drop;
656 
657 	if (ip6mr_fib_lookup(net, &fl6, &mrt) < 0)
658 		goto drop;
659 	reg_vif_num = mrt->mroute_reg_vif_num;
660 
661 	read_lock(&mrt_lock);
662 	if (reg_vif_num >= 0)
663 		reg_dev = mrt->vif6_table[reg_vif_num].dev;
664 	if (reg_dev)
665 		dev_hold(reg_dev);
666 	read_unlock(&mrt_lock);
667 
668 	if (!reg_dev)
669 		goto drop;
670 
671 	skb->mac_header = skb->network_header;
672 	skb_pull(skb, (u8 *)encap - skb->data);
673 	skb_reset_network_header(skb);
674 	skb->protocol = htons(ETH_P_IPV6);
675 	skb->ip_summed = CHECKSUM_NONE;
676 
677 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
678 
679 	netif_rx(skb);
680 
681 	dev_put(reg_dev);
682 	return 0;
683  drop:
684 	kfree_skb(skb);
685 	return 0;
686 }
687 
688 static const struct inet6_protocol pim6_protocol = {
689 	.handler	=	pim6_rcv,
690 };
691 
692 /* Service routines creating virtual interfaces: PIMREG */
693 
694 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb,
695 				      struct net_device *dev)
696 {
697 	struct net *net = dev_net(dev);
698 	struct mr6_table *mrt;
699 	struct flowi6 fl6 = {
700 		.flowi6_oif	= dev->ifindex,
701 		.flowi6_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
702 		.flowi6_mark	= skb->mark,
703 	};
704 	int err;
705 
706 	err = ip6mr_fib_lookup(net, &fl6, &mrt);
707 	if (err < 0) {
708 		kfree_skb(skb);
709 		return err;
710 	}
711 
712 	read_lock(&mrt_lock);
713 	dev->stats.tx_bytes += skb->len;
714 	dev->stats.tx_packets++;
715 	ip6mr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, MRT6MSG_WHOLEPKT);
716 	read_unlock(&mrt_lock);
717 	kfree_skb(skb);
718 	return NETDEV_TX_OK;
719 }
720 
721 static int reg_vif_get_iflink(const struct net_device *dev)
722 {
723 	return 0;
724 }
725 
726 static const struct net_device_ops reg_vif_netdev_ops = {
727 	.ndo_start_xmit	= reg_vif_xmit,
728 	.ndo_get_iflink = reg_vif_get_iflink,
729 };
730 
731 static void reg_vif_setup(struct net_device *dev)
732 {
733 	dev->type		= ARPHRD_PIMREG;
734 	dev->mtu		= 1500 - sizeof(struct ipv6hdr) - 8;
735 	dev->flags		= IFF_NOARP;
736 	dev->netdev_ops		= &reg_vif_netdev_ops;
737 	dev->destructor		= free_netdev;
738 	dev->features		|= NETIF_F_NETNS_LOCAL;
739 }
740 
741 static struct net_device *ip6mr_reg_vif(struct net *net, struct mr6_table *mrt)
742 {
743 	struct net_device *dev;
744 	char name[IFNAMSIZ];
745 
746 	if (mrt->id == RT6_TABLE_DFLT)
747 		sprintf(name, "pim6reg");
748 	else
749 		sprintf(name, "pim6reg%u", mrt->id);
750 
751 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
752 	if (!dev)
753 		return NULL;
754 
755 	dev_net_set(dev, net);
756 
757 	if (register_netdevice(dev)) {
758 		free_netdev(dev);
759 		return NULL;
760 	}
761 
762 	if (dev_open(dev))
763 		goto failure;
764 
765 	dev_hold(dev);
766 	return dev;
767 
768 failure:
769 	/* allow the register to be completed before unregistering. */
770 	rtnl_unlock();
771 	rtnl_lock();
772 
773 	unregister_netdevice(dev);
774 	return NULL;
775 }
776 #endif
777 
778 /*
779  *	Delete a VIF entry
780  */
781 
782 static int mif6_delete(struct mr6_table *mrt, int vifi, struct list_head *head)
783 {
784 	struct mif_device *v;
785 	struct net_device *dev;
786 	struct inet6_dev *in6_dev;
787 
788 	if (vifi < 0 || vifi >= mrt->maxvif)
789 		return -EADDRNOTAVAIL;
790 
791 	v = &mrt->vif6_table[vifi];
792 
793 	write_lock_bh(&mrt_lock);
794 	dev = v->dev;
795 	v->dev = NULL;
796 
797 	if (!dev) {
798 		write_unlock_bh(&mrt_lock);
799 		return -EADDRNOTAVAIL;
800 	}
801 
802 #ifdef CONFIG_IPV6_PIMSM_V2
803 	if (vifi == mrt->mroute_reg_vif_num)
804 		mrt->mroute_reg_vif_num = -1;
805 #endif
806 
807 	if (vifi + 1 == mrt->maxvif) {
808 		int tmp;
809 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
810 			if (MIF_EXISTS(mrt, tmp))
811 				break;
812 		}
813 		mrt->maxvif = tmp + 1;
814 	}
815 
816 	write_unlock_bh(&mrt_lock);
817 
818 	dev_set_allmulti(dev, -1);
819 
820 	in6_dev = __in6_dev_get(dev);
821 	if (in6_dev) {
822 		in6_dev->cnf.mc_forwarding--;
823 		inet6_netconf_notify_devconf(dev_net(dev),
824 					     NETCONFA_MC_FORWARDING,
825 					     dev->ifindex, &in6_dev->cnf);
826 	}
827 
828 	if (v->flags & MIFF_REGISTER)
829 		unregister_netdevice_queue(dev, head);
830 
831 	dev_put(dev);
832 	return 0;
833 }
834 
835 static inline void ip6mr_cache_free(struct mfc6_cache *c)
836 {
837 	kmem_cache_free(mrt_cachep, c);
838 }
839 
840 /* Destroy an unresolved cache entry, killing queued skbs
841    and reporting error to netlink readers.
842  */
843 
844 static void ip6mr_destroy_unres(struct mr6_table *mrt, struct mfc6_cache *c)
845 {
846 	struct net *net = read_pnet(&mrt->net);
847 	struct sk_buff *skb;
848 
849 	atomic_dec(&mrt->cache_resolve_queue_len);
850 
851 	while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved)) != NULL) {
852 		if (ipv6_hdr(skb)->version == 0) {
853 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct ipv6hdr));
854 			nlh->nlmsg_type = NLMSG_ERROR;
855 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
856 			skb_trim(skb, nlh->nlmsg_len);
857 			((struct nlmsgerr *)nlmsg_data(nlh))->error = -ETIMEDOUT;
858 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
859 		} else
860 			kfree_skb(skb);
861 	}
862 
863 	ip6mr_cache_free(c);
864 }
865 
866 
867 /* Timer process for all the unresolved queue. */
868 
869 static void ipmr_do_expire_process(struct mr6_table *mrt)
870 {
871 	unsigned long now = jiffies;
872 	unsigned long expires = 10 * HZ;
873 	struct mfc6_cache *c, *next;
874 
875 	list_for_each_entry_safe(c, next, &mrt->mfc6_unres_queue, list) {
876 		if (time_after(c->mfc_un.unres.expires, now)) {
877 			/* not yet... */
878 			unsigned long interval = c->mfc_un.unres.expires - now;
879 			if (interval < expires)
880 				expires = interval;
881 			continue;
882 		}
883 
884 		list_del(&c->list);
885 		mr6_netlink_event(mrt, c, RTM_DELROUTE);
886 		ip6mr_destroy_unres(mrt, c);
887 	}
888 
889 	if (!list_empty(&mrt->mfc6_unres_queue))
890 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
891 }
892 
893 static void ipmr_expire_process(unsigned long arg)
894 {
895 	struct mr6_table *mrt = (struct mr6_table *)arg;
896 
897 	if (!spin_trylock(&mfc_unres_lock)) {
898 		mod_timer(&mrt->ipmr_expire_timer, jiffies + 1);
899 		return;
900 	}
901 
902 	if (!list_empty(&mrt->mfc6_unres_queue))
903 		ipmr_do_expire_process(mrt);
904 
905 	spin_unlock(&mfc_unres_lock);
906 }
907 
908 /* Fill oifs list. It is called under write locked mrt_lock. */
909 
910 static void ip6mr_update_thresholds(struct mr6_table *mrt, struct mfc6_cache *cache,
911 				    unsigned char *ttls)
912 {
913 	int vifi;
914 
915 	cache->mfc_un.res.minvif = MAXMIFS;
916 	cache->mfc_un.res.maxvif = 0;
917 	memset(cache->mfc_un.res.ttls, 255, MAXMIFS);
918 
919 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
920 		if (MIF_EXISTS(mrt, vifi) &&
921 		    ttls[vifi] && ttls[vifi] < 255) {
922 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
923 			if (cache->mfc_un.res.minvif > vifi)
924 				cache->mfc_un.res.minvif = vifi;
925 			if (cache->mfc_un.res.maxvif <= vifi)
926 				cache->mfc_un.res.maxvif = vifi + 1;
927 		}
928 	}
929 }
930 
931 static int mif6_add(struct net *net, struct mr6_table *mrt,
932 		    struct mif6ctl *vifc, int mrtsock)
933 {
934 	int vifi = vifc->mif6c_mifi;
935 	struct mif_device *v = &mrt->vif6_table[vifi];
936 	struct net_device *dev;
937 	struct inet6_dev *in6_dev;
938 	int err;
939 
940 	/* Is vif busy ? */
941 	if (MIF_EXISTS(mrt, vifi))
942 		return -EADDRINUSE;
943 
944 	switch (vifc->mif6c_flags) {
945 #ifdef CONFIG_IPV6_PIMSM_V2
946 	case MIFF_REGISTER:
947 		/*
948 		 * Special Purpose VIF in PIM
949 		 * All the packets will be sent to the daemon
950 		 */
951 		if (mrt->mroute_reg_vif_num >= 0)
952 			return -EADDRINUSE;
953 		dev = ip6mr_reg_vif(net, mrt);
954 		if (!dev)
955 			return -ENOBUFS;
956 		err = dev_set_allmulti(dev, 1);
957 		if (err) {
958 			unregister_netdevice(dev);
959 			dev_put(dev);
960 			return err;
961 		}
962 		break;
963 #endif
964 	case 0:
965 		dev = dev_get_by_index(net, vifc->mif6c_pifi);
966 		if (!dev)
967 			return -EADDRNOTAVAIL;
968 		err = dev_set_allmulti(dev, 1);
969 		if (err) {
970 			dev_put(dev);
971 			return err;
972 		}
973 		break;
974 	default:
975 		return -EINVAL;
976 	}
977 
978 	in6_dev = __in6_dev_get(dev);
979 	if (in6_dev) {
980 		in6_dev->cnf.mc_forwarding++;
981 		inet6_netconf_notify_devconf(dev_net(dev),
982 					     NETCONFA_MC_FORWARDING,
983 					     dev->ifindex, &in6_dev->cnf);
984 	}
985 
986 	/*
987 	 *	Fill in the VIF structures
988 	 */
989 	v->rate_limit = vifc->vifc_rate_limit;
990 	v->flags = vifc->mif6c_flags;
991 	if (!mrtsock)
992 		v->flags |= VIFF_STATIC;
993 	v->threshold = vifc->vifc_threshold;
994 	v->bytes_in = 0;
995 	v->bytes_out = 0;
996 	v->pkt_in = 0;
997 	v->pkt_out = 0;
998 	v->link = dev->ifindex;
999 	if (v->flags & MIFF_REGISTER)
1000 		v->link = dev_get_iflink(dev);
1001 
1002 	/* And finish update writing critical data */
1003 	write_lock_bh(&mrt_lock);
1004 	v->dev = dev;
1005 #ifdef CONFIG_IPV6_PIMSM_V2
1006 	if (v->flags & MIFF_REGISTER)
1007 		mrt->mroute_reg_vif_num = vifi;
1008 #endif
1009 	if (vifi + 1 > mrt->maxvif)
1010 		mrt->maxvif = vifi + 1;
1011 	write_unlock_bh(&mrt_lock);
1012 	return 0;
1013 }
1014 
1015 static struct mfc6_cache *ip6mr_cache_find(struct mr6_table *mrt,
1016 					   const struct in6_addr *origin,
1017 					   const struct in6_addr *mcastgrp)
1018 {
1019 	int line = MFC6_HASH(mcastgrp, origin);
1020 	struct mfc6_cache *c;
1021 
1022 	list_for_each_entry(c, &mrt->mfc6_cache_array[line], list) {
1023 		if (ipv6_addr_equal(&c->mf6c_origin, origin) &&
1024 		    ipv6_addr_equal(&c->mf6c_mcastgrp, mcastgrp))
1025 			return c;
1026 	}
1027 	return NULL;
1028 }
1029 
1030 /* Look for a (*,*,oif) entry */
1031 static struct mfc6_cache *ip6mr_cache_find_any_parent(struct mr6_table *mrt,
1032 						      mifi_t mifi)
1033 {
1034 	int line = MFC6_HASH(&in6addr_any, &in6addr_any);
1035 	struct mfc6_cache *c;
1036 
1037 	list_for_each_entry(c, &mrt->mfc6_cache_array[line], list)
1038 		if (ipv6_addr_any(&c->mf6c_origin) &&
1039 		    ipv6_addr_any(&c->mf6c_mcastgrp) &&
1040 		    (c->mfc_un.res.ttls[mifi] < 255))
1041 			return c;
1042 
1043 	return NULL;
1044 }
1045 
1046 /* Look for a (*,G) entry */
1047 static struct mfc6_cache *ip6mr_cache_find_any(struct mr6_table *mrt,
1048 					       struct in6_addr *mcastgrp,
1049 					       mifi_t mifi)
1050 {
1051 	int line = MFC6_HASH(mcastgrp, &in6addr_any);
1052 	struct mfc6_cache *c, *proxy;
1053 
1054 	if (ipv6_addr_any(mcastgrp))
1055 		goto skip;
1056 
1057 	list_for_each_entry(c, &mrt->mfc6_cache_array[line], list)
1058 		if (ipv6_addr_any(&c->mf6c_origin) &&
1059 		    ipv6_addr_equal(&c->mf6c_mcastgrp, mcastgrp)) {
1060 			if (c->mfc_un.res.ttls[mifi] < 255)
1061 				return c;
1062 
1063 			/* It's ok if the mifi is part of the static tree */
1064 			proxy = ip6mr_cache_find_any_parent(mrt,
1065 							    c->mf6c_parent);
1066 			if (proxy && proxy->mfc_un.res.ttls[mifi] < 255)
1067 				return c;
1068 		}
1069 
1070 skip:
1071 	return ip6mr_cache_find_any_parent(mrt, mifi);
1072 }
1073 
1074 /*
1075  *	Allocate a multicast cache entry
1076  */
1077 static struct mfc6_cache *ip6mr_cache_alloc(void)
1078 {
1079 	struct mfc6_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
1080 	if (!c)
1081 		return NULL;
1082 	c->mfc_un.res.minvif = MAXMIFS;
1083 	return c;
1084 }
1085 
1086 static struct mfc6_cache *ip6mr_cache_alloc_unres(void)
1087 {
1088 	struct mfc6_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
1089 	if (!c)
1090 		return NULL;
1091 	skb_queue_head_init(&c->mfc_un.unres.unresolved);
1092 	c->mfc_un.unres.expires = jiffies + 10 * HZ;
1093 	return c;
1094 }
1095 
1096 /*
1097  *	A cache entry has gone into a resolved state from queued
1098  */
1099 
1100 static void ip6mr_cache_resolve(struct net *net, struct mr6_table *mrt,
1101 				struct mfc6_cache *uc, struct mfc6_cache *c)
1102 {
1103 	struct sk_buff *skb;
1104 
1105 	/*
1106 	 *	Play the pending entries through our router
1107 	 */
1108 
1109 	while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
1110 		if (ipv6_hdr(skb)->version == 0) {
1111 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct ipv6hdr));
1112 
1113 			if (__ip6mr_fill_mroute(mrt, skb, c, nlmsg_data(nlh)) > 0) {
1114 				nlh->nlmsg_len = skb_tail_pointer(skb) - (u8 *)nlh;
1115 			} else {
1116 				nlh->nlmsg_type = NLMSG_ERROR;
1117 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
1118 				skb_trim(skb, nlh->nlmsg_len);
1119 				((struct nlmsgerr *)nlmsg_data(nlh))->error = -EMSGSIZE;
1120 			}
1121 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
1122 		} else
1123 			ip6_mr_forward(net, mrt, skb, c);
1124 	}
1125 }
1126 
1127 /*
1128  *	Bounce a cache query up to pim6sd. We could use netlink for this but pim6sd
1129  *	expects the following bizarre scheme.
1130  *
1131  *	Called under mrt_lock.
1132  */
1133 
1134 static int ip6mr_cache_report(struct mr6_table *mrt, struct sk_buff *pkt,
1135 			      mifi_t mifi, int assert)
1136 {
1137 	struct sk_buff *skb;
1138 	struct mrt6msg *msg;
1139 	int ret;
1140 
1141 #ifdef CONFIG_IPV6_PIMSM_V2
1142 	if (assert == MRT6MSG_WHOLEPKT)
1143 		skb = skb_realloc_headroom(pkt, -skb_network_offset(pkt)
1144 						+sizeof(*msg));
1145 	else
1146 #endif
1147 		skb = alloc_skb(sizeof(struct ipv6hdr) + sizeof(*msg), GFP_ATOMIC);
1148 
1149 	if (!skb)
1150 		return -ENOBUFS;
1151 
1152 	/* I suppose that internal messages
1153 	 * do not require checksums */
1154 
1155 	skb->ip_summed = CHECKSUM_UNNECESSARY;
1156 
1157 #ifdef CONFIG_IPV6_PIMSM_V2
1158 	if (assert == MRT6MSG_WHOLEPKT) {
1159 		/* Ugly, but we have no choice with this interface.
1160 		   Duplicate old header, fix length etc.
1161 		   And all this only to mangle msg->im6_msgtype and
1162 		   to set msg->im6_mbz to "mbz" :-)
1163 		 */
1164 		skb_push(skb, -skb_network_offset(pkt));
1165 
1166 		skb_push(skb, sizeof(*msg));
1167 		skb_reset_transport_header(skb);
1168 		msg = (struct mrt6msg *)skb_transport_header(skb);
1169 		msg->im6_mbz = 0;
1170 		msg->im6_msgtype = MRT6MSG_WHOLEPKT;
1171 		msg->im6_mif = mrt->mroute_reg_vif_num;
1172 		msg->im6_pad = 0;
1173 		msg->im6_src = ipv6_hdr(pkt)->saddr;
1174 		msg->im6_dst = ipv6_hdr(pkt)->daddr;
1175 
1176 		skb->ip_summed = CHECKSUM_UNNECESSARY;
1177 	} else
1178 #endif
1179 	{
1180 	/*
1181 	 *	Copy the IP header
1182 	 */
1183 
1184 	skb_put(skb, sizeof(struct ipv6hdr));
1185 	skb_reset_network_header(skb);
1186 	skb_copy_to_linear_data(skb, ipv6_hdr(pkt), sizeof(struct ipv6hdr));
1187 
1188 	/*
1189 	 *	Add our header
1190 	 */
1191 	skb_put(skb, sizeof(*msg));
1192 	skb_reset_transport_header(skb);
1193 	msg = (struct mrt6msg *)skb_transport_header(skb);
1194 
1195 	msg->im6_mbz = 0;
1196 	msg->im6_msgtype = assert;
1197 	msg->im6_mif = mifi;
1198 	msg->im6_pad = 0;
1199 	msg->im6_src = ipv6_hdr(pkt)->saddr;
1200 	msg->im6_dst = ipv6_hdr(pkt)->daddr;
1201 
1202 	skb_dst_set(skb, dst_clone(skb_dst(pkt)));
1203 	skb->ip_summed = CHECKSUM_UNNECESSARY;
1204 	}
1205 
1206 	if (!mrt->mroute6_sk) {
1207 		kfree_skb(skb);
1208 		return -EINVAL;
1209 	}
1210 
1211 	/*
1212 	 *	Deliver to user space multicast routing algorithms
1213 	 */
1214 	ret = sock_queue_rcv_skb(mrt->mroute6_sk, skb);
1215 	if (ret < 0) {
1216 		net_warn_ratelimited("mroute6: pending queue full, dropping entries\n");
1217 		kfree_skb(skb);
1218 	}
1219 
1220 	return ret;
1221 }
1222 
1223 /*
1224  *	Queue a packet for resolution. It gets locked cache entry!
1225  */
1226 
1227 static int
1228 ip6mr_cache_unresolved(struct mr6_table *mrt, mifi_t mifi, struct sk_buff *skb)
1229 {
1230 	bool found = false;
1231 	int err;
1232 	struct mfc6_cache *c;
1233 
1234 	spin_lock_bh(&mfc_unres_lock);
1235 	list_for_each_entry(c, &mrt->mfc6_unres_queue, list) {
1236 		if (ipv6_addr_equal(&c->mf6c_mcastgrp, &ipv6_hdr(skb)->daddr) &&
1237 		    ipv6_addr_equal(&c->mf6c_origin, &ipv6_hdr(skb)->saddr)) {
1238 			found = true;
1239 			break;
1240 		}
1241 	}
1242 
1243 	if (!found) {
1244 		/*
1245 		 *	Create a new entry if allowable
1246 		 */
1247 
1248 		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
1249 		    (c = ip6mr_cache_alloc_unres()) == NULL) {
1250 			spin_unlock_bh(&mfc_unres_lock);
1251 
1252 			kfree_skb(skb);
1253 			return -ENOBUFS;
1254 		}
1255 
1256 		/*
1257 		 *	Fill in the new cache entry
1258 		 */
1259 		c->mf6c_parent = -1;
1260 		c->mf6c_origin = ipv6_hdr(skb)->saddr;
1261 		c->mf6c_mcastgrp = ipv6_hdr(skb)->daddr;
1262 
1263 		/*
1264 		 *	Reflect first query at pim6sd
1265 		 */
1266 		err = ip6mr_cache_report(mrt, skb, mifi, MRT6MSG_NOCACHE);
1267 		if (err < 0) {
1268 			/* If the report failed throw the cache entry
1269 			   out - Brad Parker
1270 			 */
1271 			spin_unlock_bh(&mfc_unres_lock);
1272 
1273 			ip6mr_cache_free(c);
1274 			kfree_skb(skb);
1275 			return err;
1276 		}
1277 
1278 		atomic_inc(&mrt->cache_resolve_queue_len);
1279 		list_add(&c->list, &mrt->mfc6_unres_queue);
1280 		mr6_netlink_event(mrt, c, RTM_NEWROUTE);
1281 
1282 		ipmr_do_expire_process(mrt);
1283 	}
1284 
1285 	/*
1286 	 *	See if we can append the packet
1287 	 */
1288 	if (c->mfc_un.unres.unresolved.qlen > 3) {
1289 		kfree_skb(skb);
1290 		err = -ENOBUFS;
1291 	} else {
1292 		skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1293 		err = 0;
1294 	}
1295 
1296 	spin_unlock_bh(&mfc_unres_lock);
1297 	return err;
1298 }
1299 
1300 /*
1301  *	MFC6 cache manipulation by user space
1302  */
1303 
1304 static int ip6mr_mfc_delete(struct mr6_table *mrt, struct mf6cctl *mfc,
1305 			    int parent)
1306 {
1307 	int line;
1308 	struct mfc6_cache *c, *next;
1309 
1310 	line = MFC6_HASH(&mfc->mf6cc_mcastgrp.sin6_addr, &mfc->mf6cc_origin.sin6_addr);
1311 
1312 	list_for_each_entry_safe(c, next, &mrt->mfc6_cache_array[line], list) {
1313 		if (ipv6_addr_equal(&c->mf6c_origin, &mfc->mf6cc_origin.sin6_addr) &&
1314 		    ipv6_addr_equal(&c->mf6c_mcastgrp,
1315 				    &mfc->mf6cc_mcastgrp.sin6_addr) &&
1316 		    (parent == -1 || parent == c->mf6c_parent)) {
1317 			write_lock_bh(&mrt_lock);
1318 			list_del(&c->list);
1319 			write_unlock_bh(&mrt_lock);
1320 
1321 			mr6_netlink_event(mrt, c, RTM_DELROUTE);
1322 			ip6mr_cache_free(c);
1323 			return 0;
1324 		}
1325 	}
1326 	return -ENOENT;
1327 }
1328 
1329 static int ip6mr_device_event(struct notifier_block *this,
1330 			      unsigned long event, void *ptr)
1331 {
1332 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1333 	struct net *net = dev_net(dev);
1334 	struct mr6_table *mrt;
1335 	struct mif_device *v;
1336 	int ct;
1337 	LIST_HEAD(list);
1338 
1339 	if (event != NETDEV_UNREGISTER)
1340 		return NOTIFY_DONE;
1341 
1342 	ip6mr_for_each_table(mrt, net) {
1343 		v = &mrt->vif6_table[0];
1344 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1345 			if (v->dev == dev)
1346 				mif6_delete(mrt, ct, &list);
1347 		}
1348 	}
1349 	unregister_netdevice_many(&list);
1350 
1351 	return NOTIFY_DONE;
1352 }
1353 
1354 static struct notifier_block ip6_mr_notifier = {
1355 	.notifier_call = ip6mr_device_event
1356 };
1357 
1358 /*
1359  *	Setup for IP multicast routing
1360  */
1361 
1362 static int __net_init ip6mr_net_init(struct net *net)
1363 {
1364 	int err;
1365 
1366 	err = ip6mr_rules_init(net);
1367 	if (err < 0)
1368 		goto fail;
1369 
1370 #ifdef CONFIG_PROC_FS
1371 	err = -ENOMEM;
1372 	if (!proc_create("ip6_mr_vif", 0, net->proc_net, &ip6mr_vif_fops))
1373 		goto proc_vif_fail;
1374 	if (!proc_create("ip6_mr_cache", 0, net->proc_net, &ip6mr_mfc_fops))
1375 		goto proc_cache_fail;
1376 #endif
1377 
1378 	return 0;
1379 
1380 #ifdef CONFIG_PROC_FS
1381 proc_cache_fail:
1382 	remove_proc_entry("ip6_mr_vif", net->proc_net);
1383 proc_vif_fail:
1384 	ip6mr_rules_exit(net);
1385 #endif
1386 fail:
1387 	return err;
1388 }
1389 
1390 static void __net_exit ip6mr_net_exit(struct net *net)
1391 {
1392 #ifdef CONFIG_PROC_FS
1393 	remove_proc_entry("ip6_mr_cache", net->proc_net);
1394 	remove_proc_entry("ip6_mr_vif", net->proc_net);
1395 #endif
1396 	ip6mr_rules_exit(net);
1397 }
1398 
1399 static struct pernet_operations ip6mr_net_ops = {
1400 	.init = ip6mr_net_init,
1401 	.exit = ip6mr_net_exit,
1402 };
1403 
1404 int __init ip6_mr_init(void)
1405 {
1406 	int err;
1407 
1408 	mrt_cachep = kmem_cache_create("ip6_mrt_cache",
1409 				       sizeof(struct mfc6_cache),
1410 				       0, SLAB_HWCACHE_ALIGN,
1411 				       NULL);
1412 	if (!mrt_cachep)
1413 		return -ENOMEM;
1414 
1415 	err = register_pernet_subsys(&ip6mr_net_ops);
1416 	if (err)
1417 		goto reg_pernet_fail;
1418 
1419 	err = register_netdevice_notifier(&ip6_mr_notifier);
1420 	if (err)
1421 		goto reg_notif_fail;
1422 #ifdef CONFIG_IPV6_PIMSM_V2
1423 	if (inet6_add_protocol(&pim6_protocol, IPPROTO_PIM) < 0) {
1424 		pr_err("%s: can't add PIM protocol\n", __func__);
1425 		err = -EAGAIN;
1426 		goto add_proto_fail;
1427 	}
1428 #endif
1429 	rtnl_register(RTNL_FAMILY_IP6MR, RTM_GETROUTE, NULL,
1430 		      ip6mr_rtm_dumproute, NULL);
1431 	return 0;
1432 #ifdef CONFIG_IPV6_PIMSM_V2
1433 add_proto_fail:
1434 	unregister_netdevice_notifier(&ip6_mr_notifier);
1435 #endif
1436 reg_notif_fail:
1437 	unregister_pernet_subsys(&ip6mr_net_ops);
1438 reg_pernet_fail:
1439 	kmem_cache_destroy(mrt_cachep);
1440 	return err;
1441 }
1442 
1443 void ip6_mr_cleanup(void)
1444 {
1445 	rtnl_unregister(RTNL_FAMILY_IP6MR, RTM_GETROUTE);
1446 #ifdef CONFIG_IPV6_PIMSM_V2
1447 	inet6_del_protocol(&pim6_protocol, IPPROTO_PIM);
1448 #endif
1449 	unregister_netdevice_notifier(&ip6_mr_notifier);
1450 	unregister_pernet_subsys(&ip6mr_net_ops);
1451 	kmem_cache_destroy(mrt_cachep);
1452 }
1453 
1454 static int ip6mr_mfc_add(struct net *net, struct mr6_table *mrt,
1455 			 struct mf6cctl *mfc, int mrtsock, int parent)
1456 {
1457 	bool found = false;
1458 	int line;
1459 	struct mfc6_cache *uc, *c;
1460 	unsigned char ttls[MAXMIFS];
1461 	int i;
1462 
1463 	if (mfc->mf6cc_parent >= MAXMIFS)
1464 		return -ENFILE;
1465 
1466 	memset(ttls, 255, MAXMIFS);
1467 	for (i = 0; i < MAXMIFS; i++) {
1468 		if (IF_ISSET(i, &mfc->mf6cc_ifset))
1469 			ttls[i] = 1;
1470 
1471 	}
1472 
1473 	line = MFC6_HASH(&mfc->mf6cc_mcastgrp.sin6_addr, &mfc->mf6cc_origin.sin6_addr);
1474 
1475 	list_for_each_entry(c, &mrt->mfc6_cache_array[line], list) {
1476 		if (ipv6_addr_equal(&c->mf6c_origin, &mfc->mf6cc_origin.sin6_addr) &&
1477 		    ipv6_addr_equal(&c->mf6c_mcastgrp,
1478 				    &mfc->mf6cc_mcastgrp.sin6_addr) &&
1479 		    (parent == -1 || parent == mfc->mf6cc_parent)) {
1480 			found = true;
1481 			break;
1482 		}
1483 	}
1484 
1485 	if (found) {
1486 		write_lock_bh(&mrt_lock);
1487 		c->mf6c_parent = mfc->mf6cc_parent;
1488 		ip6mr_update_thresholds(mrt, c, ttls);
1489 		if (!mrtsock)
1490 			c->mfc_flags |= MFC_STATIC;
1491 		write_unlock_bh(&mrt_lock);
1492 		mr6_netlink_event(mrt, c, RTM_NEWROUTE);
1493 		return 0;
1494 	}
1495 
1496 	if (!ipv6_addr_any(&mfc->mf6cc_mcastgrp.sin6_addr) &&
1497 	    !ipv6_addr_is_multicast(&mfc->mf6cc_mcastgrp.sin6_addr))
1498 		return -EINVAL;
1499 
1500 	c = ip6mr_cache_alloc();
1501 	if (!c)
1502 		return -ENOMEM;
1503 
1504 	c->mf6c_origin = mfc->mf6cc_origin.sin6_addr;
1505 	c->mf6c_mcastgrp = mfc->mf6cc_mcastgrp.sin6_addr;
1506 	c->mf6c_parent = mfc->mf6cc_parent;
1507 	ip6mr_update_thresholds(mrt, c, ttls);
1508 	if (!mrtsock)
1509 		c->mfc_flags |= MFC_STATIC;
1510 
1511 	write_lock_bh(&mrt_lock);
1512 	list_add(&c->list, &mrt->mfc6_cache_array[line]);
1513 	write_unlock_bh(&mrt_lock);
1514 
1515 	/*
1516 	 *	Check to see if we resolved a queued list. If so we
1517 	 *	need to send on the frames and tidy up.
1518 	 */
1519 	found = false;
1520 	spin_lock_bh(&mfc_unres_lock);
1521 	list_for_each_entry(uc, &mrt->mfc6_unres_queue, list) {
1522 		if (ipv6_addr_equal(&uc->mf6c_origin, &c->mf6c_origin) &&
1523 		    ipv6_addr_equal(&uc->mf6c_mcastgrp, &c->mf6c_mcastgrp)) {
1524 			list_del(&uc->list);
1525 			atomic_dec(&mrt->cache_resolve_queue_len);
1526 			found = true;
1527 			break;
1528 		}
1529 	}
1530 	if (list_empty(&mrt->mfc6_unres_queue))
1531 		del_timer(&mrt->ipmr_expire_timer);
1532 	spin_unlock_bh(&mfc_unres_lock);
1533 
1534 	if (found) {
1535 		ip6mr_cache_resolve(net, mrt, uc, c);
1536 		ip6mr_cache_free(uc);
1537 	}
1538 	mr6_netlink_event(mrt, c, RTM_NEWROUTE);
1539 	return 0;
1540 }
1541 
1542 /*
1543  *	Close the multicast socket, and clear the vif tables etc
1544  */
1545 
1546 static void mroute_clean_tables(struct mr6_table *mrt)
1547 {
1548 	int i;
1549 	LIST_HEAD(list);
1550 	struct mfc6_cache *c, *next;
1551 
1552 	/*
1553 	 *	Shut down all active vif entries
1554 	 */
1555 	for (i = 0; i < mrt->maxvif; i++) {
1556 		if (!(mrt->vif6_table[i].flags & VIFF_STATIC))
1557 			mif6_delete(mrt, i, &list);
1558 	}
1559 	unregister_netdevice_many(&list);
1560 
1561 	/*
1562 	 *	Wipe the cache
1563 	 */
1564 	for (i = 0; i < MFC6_LINES; i++) {
1565 		list_for_each_entry_safe(c, next, &mrt->mfc6_cache_array[i], list) {
1566 			if (c->mfc_flags & MFC_STATIC)
1567 				continue;
1568 			write_lock_bh(&mrt_lock);
1569 			list_del(&c->list);
1570 			write_unlock_bh(&mrt_lock);
1571 
1572 			mr6_netlink_event(mrt, c, RTM_DELROUTE);
1573 			ip6mr_cache_free(c);
1574 		}
1575 	}
1576 
1577 	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1578 		spin_lock_bh(&mfc_unres_lock);
1579 		list_for_each_entry_safe(c, next, &mrt->mfc6_unres_queue, list) {
1580 			list_del(&c->list);
1581 			mr6_netlink_event(mrt, c, RTM_DELROUTE);
1582 			ip6mr_destroy_unres(mrt, c);
1583 		}
1584 		spin_unlock_bh(&mfc_unres_lock);
1585 	}
1586 }
1587 
1588 static int ip6mr_sk_init(struct mr6_table *mrt, struct sock *sk)
1589 {
1590 	int err = 0;
1591 	struct net *net = sock_net(sk);
1592 
1593 	rtnl_lock();
1594 	write_lock_bh(&mrt_lock);
1595 	if (likely(mrt->mroute6_sk == NULL)) {
1596 		mrt->mroute6_sk = sk;
1597 		net->ipv6.devconf_all->mc_forwarding++;
1598 		inet6_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1599 					     NETCONFA_IFINDEX_ALL,
1600 					     net->ipv6.devconf_all);
1601 	}
1602 	else
1603 		err = -EADDRINUSE;
1604 	write_unlock_bh(&mrt_lock);
1605 
1606 	rtnl_unlock();
1607 
1608 	return err;
1609 }
1610 
1611 int ip6mr_sk_done(struct sock *sk)
1612 {
1613 	int err = -EACCES;
1614 	struct net *net = sock_net(sk);
1615 	struct mr6_table *mrt;
1616 
1617 	rtnl_lock();
1618 	ip6mr_for_each_table(mrt, net) {
1619 		if (sk == mrt->mroute6_sk) {
1620 			write_lock_bh(&mrt_lock);
1621 			mrt->mroute6_sk = NULL;
1622 			net->ipv6.devconf_all->mc_forwarding--;
1623 			inet6_netconf_notify_devconf(net,
1624 						     NETCONFA_MC_FORWARDING,
1625 						     NETCONFA_IFINDEX_ALL,
1626 						     net->ipv6.devconf_all);
1627 			write_unlock_bh(&mrt_lock);
1628 
1629 			mroute_clean_tables(mrt);
1630 			err = 0;
1631 			break;
1632 		}
1633 	}
1634 	rtnl_unlock();
1635 
1636 	return err;
1637 }
1638 
1639 struct sock *mroute6_socket(struct net *net, struct sk_buff *skb)
1640 {
1641 	struct mr6_table *mrt;
1642 	struct flowi6 fl6 = {
1643 		.flowi6_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
1644 		.flowi6_oif	= skb->dev->ifindex,
1645 		.flowi6_mark	= skb->mark,
1646 	};
1647 
1648 	if (ip6mr_fib_lookup(net, &fl6, &mrt) < 0)
1649 		return NULL;
1650 
1651 	return mrt->mroute6_sk;
1652 }
1653 
1654 /*
1655  *	Socket options and virtual interface manipulation. The whole
1656  *	virtual interface system is a complete heap, but unfortunately
1657  *	that's how BSD mrouted happens to think. Maybe one day with a proper
1658  *	MOSPF/PIM router set up we can clean this up.
1659  */
1660 
1661 int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen)
1662 {
1663 	int ret, parent = 0;
1664 	struct mif6ctl vif;
1665 	struct mf6cctl mfc;
1666 	mifi_t mifi;
1667 	struct net *net = sock_net(sk);
1668 	struct mr6_table *mrt;
1669 
1670 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
1671 	if (!mrt)
1672 		return -ENOENT;
1673 
1674 	if (optname != MRT6_INIT) {
1675 		if (sk != mrt->mroute6_sk && !ns_capable(net->user_ns, CAP_NET_ADMIN))
1676 			return -EACCES;
1677 	}
1678 
1679 	switch (optname) {
1680 	case MRT6_INIT:
1681 		if (sk->sk_type != SOCK_RAW ||
1682 		    inet_sk(sk)->inet_num != IPPROTO_ICMPV6)
1683 			return -EOPNOTSUPP;
1684 		if (optlen < sizeof(int))
1685 			return -EINVAL;
1686 
1687 		return ip6mr_sk_init(mrt, sk);
1688 
1689 	case MRT6_DONE:
1690 		return ip6mr_sk_done(sk);
1691 
1692 	case MRT6_ADD_MIF:
1693 		if (optlen < sizeof(vif))
1694 			return -EINVAL;
1695 		if (copy_from_user(&vif, optval, sizeof(vif)))
1696 			return -EFAULT;
1697 		if (vif.mif6c_mifi >= MAXMIFS)
1698 			return -ENFILE;
1699 		rtnl_lock();
1700 		ret = mif6_add(net, mrt, &vif, sk == mrt->mroute6_sk);
1701 		rtnl_unlock();
1702 		return ret;
1703 
1704 	case MRT6_DEL_MIF:
1705 		if (optlen < sizeof(mifi_t))
1706 			return -EINVAL;
1707 		if (copy_from_user(&mifi, optval, sizeof(mifi_t)))
1708 			return -EFAULT;
1709 		rtnl_lock();
1710 		ret = mif6_delete(mrt, mifi, NULL);
1711 		rtnl_unlock();
1712 		return ret;
1713 
1714 	/*
1715 	 *	Manipulate the forwarding caches. These live
1716 	 *	in a sort of kernel/user symbiosis.
1717 	 */
1718 	case MRT6_ADD_MFC:
1719 	case MRT6_DEL_MFC:
1720 		parent = -1;
1721 	case MRT6_ADD_MFC_PROXY:
1722 	case MRT6_DEL_MFC_PROXY:
1723 		if (optlen < sizeof(mfc))
1724 			return -EINVAL;
1725 		if (copy_from_user(&mfc, optval, sizeof(mfc)))
1726 			return -EFAULT;
1727 		if (parent == 0)
1728 			parent = mfc.mf6cc_parent;
1729 		rtnl_lock();
1730 		if (optname == MRT6_DEL_MFC || optname == MRT6_DEL_MFC_PROXY)
1731 			ret = ip6mr_mfc_delete(mrt, &mfc, parent);
1732 		else
1733 			ret = ip6mr_mfc_add(net, mrt, &mfc,
1734 					    sk == mrt->mroute6_sk, parent);
1735 		rtnl_unlock();
1736 		return ret;
1737 
1738 	/*
1739 	 *	Control PIM assert (to activate pim will activate assert)
1740 	 */
1741 	case MRT6_ASSERT:
1742 	{
1743 		int v;
1744 
1745 		if (optlen != sizeof(v))
1746 			return -EINVAL;
1747 		if (get_user(v, (int __user *)optval))
1748 			return -EFAULT;
1749 		mrt->mroute_do_assert = v;
1750 		return 0;
1751 	}
1752 
1753 #ifdef CONFIG_IPV6_PIMSM_V2
1754 	case MRT6_PIM:
1755 	{
1756 		int v;
1757 
1758 		if (optlen != sizeof(v))
1759 			return -EINVAL;
1760 		if (get_user(v, (int __user *)optval))
1761 			return -EFAULT;
1762 		v = !!v;
1763 		rtnl_lock();
1764 		ret = 0;
1765 		if (v != mrt->mroute_do_pim) {
1766 			mrt->mroute_do_pim = v;
1767 			mrt->mroute_do_assert = v;
1768 		}
1769 		rtnl_unlock();
1770 		return ret;
1771 	}
1772 
1773 #endif
1774 #ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
1775 	case MRT6_TABLE:
1776 	{
1777 		u32 v;
1778 
1779 		if (optlen != sizeof(u32))
1780 			return -EINVAL;
1781 		if (get_user(v, (u32 __user *)optval))
1782 			return -EFAULT;
1783 		/* "pim6reg%u" should not exceed 16 bytes (IFNAMSIZ) */
1784 		if (v != RT_TABLE_DEFAULT && v >= 100000000)
1785 			return -EINVAL;
1786 		if (sk == mrt->mroute6_sk)
1787 			return -EBUSY;
1788 
1789 		rtnl_lock();
1790 		ret = 0;
1791 		if (!ip6mr_new_table(net, v))
1792 			ret = -ENOMEM;
1793 		raw6_sk(sk)->ip6mr_table = v;
1794 		rtnl_unlock();
1795 		return ret;
1796 	}
1797 #endif
1798 	/*
1799 	 *	Spurious command, or MRT6_VERSION which you cannot
1800 	 *	set.
1801 	 */
1802 	default:
1803 		return -ENOPROTOOPT;
1804 	}
1805 }
1806 
1807 /*
1808  *	Getsock opt support for the multicast routing system.
1809  */
1810 
1811 int ip6_mroute_getsockopt(struct sock *sk, int optname, char __user *optval,
1812 			  int __user *optlen)
1813 {
1814 	int olr;
1815 	int val;
1816 	struct net *net = sock_net(sk);
1817 	struct mr6_table *mrt;
1818 
1819 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
1820 	if (!mrt)
1821 		return -ENOENT;
1822 
1823 	switch (optname) {
1824 	case MRT6_VERSION:
1825 		val = 0x0305;
1826 		break;
1827 #ifdef CONFIG_IPV6_PIMSM_V2
1828 	case MRT6_PIM:
1829 		val = mrt->mroute_do_pim;
1830 		break;
1831 #endif
1832 	case MRT6_ASSERT:
1833 		val = mrt->mroute_do_assert;
1834 		break;
1835 	default:
1836 		return -ENOPROTOOPT;
1837 	}
1838 
1839 	if (get_user(olr, optlen))
1840 		return -EFAULT;
1841 
1842 	olr = min_t(int, olr, sizeof(int));
1843 	if (olr < 0)
1844 		return -EINVAL;
1845 
1846 	if (put_user(olr, optlen))
1847 		return -EFAULT;
1848 	if (copy_to_user(optval, &val, olr))
1849 		return -EFAULT;
1850 	return 0;
1851 }
1852 
1853 /*
1854  *	The IP multicast ioctl support routines.
1855  */
1856 
1857 int ip6mr_ioctl(struct sock *sk, int cmd, void __user *arg)
1858 {
1859 	struct sioc_sg_req6 sr;
1860 	struct sioc_mif_req6 vr;
1861 	struct mif_device *vif;
1862 	struct mfc6_cache *c;
1863 	struct net *net = sock_net(sk);
1864 	struct mr6_table *mrt;
1865 
1866 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
1867 	if (!mrt)
1868 		return -ENOENT;
1869 
1870 	switch (cmd) {
1871 	case SIOCGETMIFCNT_IN6:
1872 		if (copy_from_user(&vr, arg, sizeof(vr)))
1873 			return -EFAULT;
1874 		if (vr.mifi >= mrt->maxvif)
1875 			return -EINVAL;
1876 		read_lock(&mrt_lock);
1877 		vif = &mrt->vif6_table[vr.mifi];
1878 		if (MIF_EXISTS(mrt, vr.mifi)) {
1879 			vr.icount = vif->pkt_in;
1880 			vr.ocount = vif->pkt_out;
1881 			vr.ibytes = vif->bytes_in;
1882 			vr.obytes = vif->bytes_out;
1883 			read_unlock(&mrt_lock);
1884 
1885 			if (copy_to_user(arg, &vr, sizeof(vr)))
1886 				return -EFAULT;
1887 			return 0;
1888 		}
1889 		read_unlock(&mrt_lock);
1890 		return -EADDRNOTAVAIL;
1891 	case SIOCGETSGCNT_IN6:
1892 		if (copy_from_user(&sr, arg, sizeof(sr)))
1893 			return -EFAULT;
1894 
1895 		read_lock(&mrt_lock);
1896 		c = ip6mr_cache_find(mrt, &sr.src.sin6_addr, &sr.grp.sin6_addr);
1897 		if (c) {
1898 			sr.pktcnt = c->mfc_un.res.pkt;
1899 			sr.bytecnt = c->mfc_un.res.bytes;
1900 			sr.wrong_if = c->mfc_un.res.wrong_if;
1901 			read_unlock(&mrt_lock);
1902 
1903 			if (copy_to_user(arg, &sr, sizeof(sr)))
1904 				return -EFAULT;
1905 			return 0;
1906 		}
1907 		read_unlock(&mrt_lock);
1908 		return -EADDRNOTAVAIL;
1909 	default:
1910 		return -ENOIOCTLCMD;
1911 	}
1912 }
1913 
1914 #ifdef CONFIG_COMPAT
1915 struct compat_sioc_sg_req6 {
1916 	struct sockaddr_in6 src;
1917 	struct sockaddr_in6 grp;
1918 	compat_ulong_t pktcnt;
1919 	compat_ulong_t bytecnt;
1920 	compat_ulong_t wrong_if;
1921 };
1922 
1923 struct compat_sioc_mif_req6 {
1924 	mifi_t	mifi;
1925 	compat_ulong_t icount;
1926 	compat_ulong_t ocount;
1927 	compat_ulong_t ibytes;
1928 	compat_ulong_t obytes;
1929 };
1930 
1931 int ip6mr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1932 {
1933 	struct compat_sioc_sg_req6 sr;
1934 	struct compat_sioc_mif_req6 vr;
1935 	struct mif_device *vif;
1936 	struct mfc6_cache *c;
1937 	struct net *net = sock_net(sk);
1938 	struct mr6_table *mrt;
1939 
1940 	mrt = ip6mr_get_table(net, raw6_sk(sk)->ip6mr_table ? : RT6_TABLE_DFLT);
1941 	if (!mrt)
1942 		return -ENOENT;
1943 
1944 	switch (cmd) {
1945 	case SIOCGETMIFCNT_IN6:
1946 		if (copy_from_user(&vr, arg, sizeof(vr)))
1947 			return -EFAULT;
1948 		if (vr.mifi >= mrt->maxvif)
1949 			return -EINVAL;
1950 		read_lock(&mrt_lock);
1951 		vif = &mrt->vif6_table[vr.mifi];
1952 		if (MIF_EXISTS(mrt, vr.mifi)) {
1953 			vr.icount = vif->pkt_in;
1954 			vr.ocount = vif->pkt_out;
1955 			vr.ibytes = vif->bytes_in;
1956 			vr.obytes = vif->bytes_out;
1957 			read_unlock(&mrt_lock);
1958 
1959 			if (copy_to_user(arg, &vr, sizeof(vr)))
1960 				return -EFAULT;
1961 			return 0;
1962 		}
1963 		read_unlock(&mrt_lock);
1964 		return -EADDRNOTAVAIL;
1965 	case SIOCGETSGCNT_IN6:
1966 		if (copy_from_user(&sr, arg, sizeof(sr)))
1967 			return -EFAULT;
1968 
1969 		read_lock(&mrt_lock);
1970 		c = ip6mr_cache_find(mrt, &sr.src.sin6_addr, &sr.grp.sin6_addr);
1971 		if (c) {
1972 			sr.pktcnt = c->mfc_un.res.pkt;
1973 			sr.bytecnt = c->mfc_un.res.bytes;
1974 			sr.wrong_if = c->mfc_un.res.wrong_if;
1975 			read_unlock(&mrt_lock);
1976 
1977 			if (copy_to_user(arg, &sr, sizeof(sr)))
1978 				return -EFAULT;
1979 			return 0;
1980 		}
1981 		read_unlock(&mrt_lock);
1982 		return -EADDRNOTAVAIL;
1983 	default:
1984 		return -ENOIOCTLCMD;
1985 	}
1986 }
1987 #endif
1988 
1989 static inline int ip6mr_forward2_finish(struct sock *sk, struct sk_buff *skb)
1990 {
1991 	IP6_INC_STATS_BH(dev_net(skb_dst(skb)->dev), ip6_dst_idev(skb_dst(skb)),
1992 			 IPSTATS_MIB_OUTFORWDATAGRAMS);
1993 	IP6_ADD_STATS_BH(dev_net(skb_dst(skb)->dev), ip6_dst_idev(skb_dst(skb)),
1994 			 IPSTATS_MIB_OUTOCTETS, skb->len);
1995 	return dst_output_sk(sk, skb);
1996 }
1997 
1998 /*
1999  *	Processing handlers for ip6mr_forward
2000  */
2001 
2002 static int ip6mr_forward2(struct net *net, struct mr6_table *mrt,
2003 			  struct sk_buff *skb, struct mfc6_cache *c, int vifi)
2004 {
2005 	struct ipv6hdr *ipv6h;
2006 	struct mif_device *vif = &mrt->vif6_table[vifi];
2007 	struct net_device *dev;
2008 	struct dst_entry *dst;
2009 	struct flowi6 fl6;
2010 
2011 	if (!vif->dev)
2012 		goto out_free;
2013 
2014 #ifdef CONFIG_IPV6_PIMSM_V2
2015 	if (vif->flags & MIFF_REGISTER) {
2016 		vif->pkt_out++;
2017 		vif->bytes_out += skb->len;
2018 		vif->dev->stats.tx_bytes += skb->len;
2019 		vif->dev->stats.tx_packets++;
2020 		ip6mr_cache_report(mrt, skb, vifi, MRT6MSG_WHOLEPKT);
2021 		goto out_free;
2022 	}
2023 #endif
2024 
2025 	ipv6h = ipv6_hdr(skb);
2026 
2027 	fl6 = (struct flowi6) {
2028 		.flowi6_oif = vif->link,
2029 		.daddr = ipv6h->daddr,
2030 	};
2031 
2032 	dst = ip6_route_output(net, NULL, &fl6);
2033 	if (dst->error) {
2034 		dst_release(dst);
2035 		goto out_free;
2036 	}
2037 
2038 	skb_dst_drop(skb);
2039 	skb_dst_set(skb, dst);
2040 
2041 	/*
2042 	 * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
2043 	 * not only before forwarding, but after forwarding on all output
2044 	 * interfaces. It is clear, if mrouter runs a multicasting
2045 	 * program, it should receive packets not depending to what interface
2046 	 * program is joined.
2047 	 * If we will not make it, the program will have to join on all
2048 	 * interfaces. On the other hand, multihoming host (or router, but
2049 	 * not mrouter) cannot join to more than one interface - it will
2050 	 * result in receiving multiple packets.
2051 	 */
2052 	dev = vif->dev;
2053 	skb->dev = dev;
2054 	vif->pkt_out++;
2055 	vif->bytes_out += skb->len;
2056 
2057 	/* We are about to write */
2058 	/* XXX: extension headers? */
2059 	if (skb_cow(skb, sizeof(*ipv6h) + LL_RESERVED_SPACE(dev)))
2060 		goto out_free;
2061 
2062 	ipv6h = ipv6_hdr(skb);
2063 	ipv6h->hop_limit--;
2064 
2065 	IP6CB(skb)->flags |= IP6SKB_FORWARDED;
2066 
2067 	return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, NULL, skb,
2068 		       skb->dev, dev,
2069 		       ip6mr_forward2_finish);
2070 
2071 out_free:
2072 	kfree_skb(skb);
2073 	return 0;
2074 }
2075 
2076 static int ip6mr_find_vif(struct mr6_table *mrt, struct net_device *dev)
2077 {
2078 	int ct;
2079 
2080 	for (ct = mrt->maxvif - 1; ct >= 0; ct--) {
2081 		if (mrt->vif6_table[ct].dev == dev)
2082 			break;
2083 	}
2084 	return ct;
2085 }
2086 
2087 static void ip6_mr_forward(struct net *net, struct mr6_table *mrt,
2088 			   struct sk_buff *skb, struct mfc6_cache *cache)
2089 {
2090 	int psend = -1;
2091 	int vif, ct;
2092 	int true_vifi = ip6mr_find_vif(mrt, skb->dev);
2093 
2094 	vif = cache->mf6c_parent;
2095 	cache->mfc_un.res.pkt++;
2096 	cache->mfc_un.res.bytes += skb->len;
2097 
2098 	if (ipv6_addr_any(&cache->mf6c_origin) && true_vifi >= 0) {
2099 		struct mfc6_cache *cache_proxy;
2100 
2101 		/* For an (*,G) entry, we only check that the incoming
2102 		 * interface is part of the static tree.
2103 		 */
2104 		cache_proxy = ip6mr_cache_find_any_parent(mrt, vif);
2105 		if (cache_proxy &&
2106 		    cache_proxy->mfc_un.res.ttls[true_vifi] < 255)
2107 			goto forward;
2108 	}
2109 
2110 	/*
2111 	 * Wrong interface: drop packet and (maybe) send PIM assert.
2112 	 */
2113 	if (mrt->vif6_table[vif].dev != skb->dev) {
2114 		cache->mfc_un.res.wrong_if++;
2115 
2116 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
2117 		    /* pimsm uses asserts, when switching from RPT to SPT,
2118 		       so that we cannot check that packet arrived on an oif.
2119 		       It is bad, but otherwise we would need to move pretty
2120 		       large chunk of pimd to kernel. Ough... --ANK
2121 		     */
2122 		    (mrt->mroute_do_pim ||
2123 		     cache->mfc_un.res.ttls[true_vifi] < 255) &&
2124 		    time_after(jiffies,
2125 			       cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
2126 			cache->mfc_un.res.last_assert = jiffies;
2127 			ip6mr_cache_report(mrt, skb, true_vifi, MRT6MSG_WRONGMIF);
2128 		}
2129 		goto dont_forward;
2130 	}
2131 
2132 forward:
2133 	mrt->vif6_table[vif].pkt_in++;
2134 	mrt->vif6_table[vif].bytes_in += skb->len;
2135 
2136 	/*
2137 	 *	Forward the frame
2138 	 */
2139 	if (ipv6_addr_any(&cache->mf6c_origin) &&
2140 	    ipv6_addr_any(&cache->mf6c_mcastgrp)) {
2141 		if (true_vifi >= 0 &&
2142 		    true_vifi != cache->mf6c_parent &&
2143 		    ipv6_hdr(skb)->hop_limit >
2144 				cache->mfc_un.res.ttls[cache->mf6c_parent]) {
2145 			/* It's an (*,*) entry and the packet is not coming from
2146 			 * the upstream: forward the packet to the upstream
2147 			 * only.
2148 			 */
2149 			psend = cache->mf6c_parent;
2150 			goto last_forward;
2151 		}
2152 		goto dont_forward;
2153 	}
2154 	for (ct = cache->mfc_un.res.maxvif - 1; ct >= cache->mfc_un.res.minvif; ct--) {
2155 		/* For (*,G) entry, don't forward to the incoming interface */
2156 		if ((!ipv6_addr_any(&cache->mf6c_origin) || ct != true_vifi) &&
2157 		    ipv6_hdr(skb)->hop_limit > cache->mfc_un.res.ttls[ct]) {
2158 			if (psend != -1) {
2159 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2160 				if (skb2)
2161 					ip6mr_forward2(net, mrt, skb2, cache, psend);
2162 			}
2163 			psend = ct;
2164 		}
2165 	}
2166 last_forward:
2167 	if (psend != -1) {
2168 		ip6mr_forward2(net, mrt, skb, cache, psend);
2169 		return;
2170 	}
2171 
2172 dont_forward:
2173 	kfree_skb(skb);
2174 }
2175 
2176 
2177 /*
2178  *	Multicast packets for forwarding arrive here
2179  */
2180 
2181 int ip6_mr_input(struct sk_buff *skb)
2182 {
2183 	struct mfc6_cache *cache;
2184 	struct net *net = dev_net(skb->dev);
2185 	struct mr6_table *mrt;
2186 	struct flowi6 fl6 = {
2187 		.flowi6_iif	= skb->dev->ifindex,
2188 		.flowi6_mark	= skb->mark,
2189 	};
2190 	int err;
2191 
2192 	err = ip6mr_fib_lookup(net, &fl6, &mrt);
2193 	if (err < 0) {
2194 		kfree_skb(skb);
2195 		return err;
2196 	}
2197 
2198 	read_lock(&mrt_lock);
2199 	cache = ip6mr_cache_find(mrt,
2200 				 &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr);
2201 	if (!cache) {
2202 		int vif = ip6mr_find_vif(mrt, skb->dev);
2203 
2204 		if (vif >= 0)
2205 			cache = ip6mr_cache_find_any(mrt,
2206 						     &ipv6_hdr(skb)->daddr,
2207 						     vif);
2208 	}
2209 
2210 	/*
2211 	 *	No usable cache entry
2212 	 */
2213 	if (!cache) {
2214 		int vif;
2215 
2216 		vif = ip6mr_find_vif(mrt, skb->dev);
2217 		if (vif >= 0) {
2218 			int err = ip6mr_cache_unresolved(mrt, vif, skb);
2219 			read_unlock(&mrt_lock);
2220 
2221 			return err;
2222 		}
2223 		read_unlock(&mrt_lock);
2224 		kfree_skb(skb);
2225 		return -ENODEV;
2226 	}
2227 
2228 	ip6_mr_forward(net, mrt, skb, cache);
2229 
2230 	read_unlock(&mrt_lock);
2231 
2232 	return 0;
2233 }
2234 
2235 
2236 static int __ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb,
2237 			       struct mfc6_cache *c, struct rtmsg *rtm)
2238 {
2239 	int ct;
2240 	struct rtnexthop *nhp;
2241 	struct nlattr *mp_attr;
2242 	struct rta_mfc_stats mfcs;
2243 
2244 	/* If cache is unresolved, don't try to parse IIF and OIF */
2245 	if (c->mf6c_parent >= MAXMIFS)
2246 		return -ENOENT;
2247 
2248 	if (MIF_EXISTS(mrt, c->mf6c_parent) &&
2249 	    nla_put_u32(skb, RTA_IIF, mrt->vif6_table[c->mf6c_parent].dev->ifindex) < 0)
2250 		return -EMSGSIZE;
2251 	mp_attr = nla_nest_start(skb, RTA_MULTIPATH);
2252 	if (!mp_attr)
2253 		return -EMSGSIZE;
2254 
2255 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
2256 		if (MIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
2257 			nhp = nla_reserve_nohdr(skb, sizeof(*nhp));
2258 			if (!nhp) {
2259 				nla_nest_cancel(skb, mp_attr);
2260 				return -EMSGSIZE;
2261 			}
2262 
2263 			nhp->rtnh_flags = 0;
2264 			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
2265 			nhp->rtnh_ifindex = mrt->vif6_table[ct].dev->ifindex;
2266 			nhp->rtnh_len = sizeof(*nhp);
2267 		}
2268 	}
2269 
2270 	nla_nest_end(skb, mp_attr);
2271 
2272 	mfcs.mfcs_packets = c->mfc_un.res.pkt;
2273 	mfcs.mfcs_bytes = c->mfc_un.res.bytes;
2274 	mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
2275 	if (nla_put(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs) < 0)
2276 		return -EMSGSIZE;
2277 
2278 	rtm->rtm_type = RTN_MULTICAST;
2279 	return 1;
2280 }
2281 
2282 int ip6mr_get_route(struct net *net,
2283 		    struct sk_buff *skb, struct rtmsg *rtm, int nowait)
2284 {
2285 	int err;
2286 	struct mr6_table *mrt;
2287 	struct mfc6_cache *cache;
2288 	struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
2289 
2290 	mrt = ip6mr_get_table(net, RT6_TABLE_DFLT);
2291 	if (!mrt)
2292 		return -ENOENT;
2293 
2294 	read_lock(&mrt_lock);
2295 	cache = ip6mr_cache_find(mrt, &rt->rt6i_src.addr, &rt->rt6i_dst.addr);
2296 	if (!cache && skb->dev) {
2297 		int vif = ip6mr_find_vif(mrt, skb->dev);
2298 
2299 		if (vif >= 0)
2300 			cache = ip6mr_cache_find_any(mrt, &rt->rt6i_dst.addr,
2301 						     vif);
2302 	}
2303 
2304 	if (!cache) {
2305 		struct sk_buff *skb2;
2306 		struct ipv6hdr *iph;
2307 		struct net_device *dev;
2308 		int vif;
2309 
2310 		if (nowait) {
2311 			read_unlock(&mrt_lock);
2312 			return -EAGAIN;
2313 		}
2314 
2315 		dev = skb->dev;
2316 		if (!dev || (vif = ip6mr_find_vif(mrt, dev)) < 0) {
2317 			read_unlock(&mrt_lock);
2318 			return -ENODEV;
2319 		}
2320 
2321 		/* really correct? */
2322 		skb2 = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
2323 		if (!skb2) {
2324 			read_unlock(&mrt_lock);
2325 			return -ENOMEM;
2326 		}
2327 
2328 		skb_reset_transport_header(skb2);
2329 
2330 		skb_put(skb2, sizeof(struct ipv6hdr));
2331 		skb_reset_network_header(skb2);
2332 
2333 		iph = ipv6_hdr(skb2);
2334 		iph->version = 0;
2335 		iph->priority = 0;
2336 		iph->flow_lbl[0] = 0;
2337 		iph->flow_lbl[1] = 0;
2338 		iph->flow_lbl[2] = 0;
2339 		iph->payload_len = 0;
2340 		iph->nexthdr = IPPROTO_NONE;
2341 		iph->hop_limit = 0;
2342 		iph->saddr = rt->rt6i_src.addr;
2343 		iph->daddr = rt->rt6i_dst.addr;
2344 
2345 		err = ip6mr_cache_unresolved(mrt, vif, skb2);
2346 		read_unlock(&mrt_lock);
2347 
2348 		return err;
2349 	}
2350 
2351 	if (!nowait && (rtm->rtm_flags&RTM_F_NOTIFY))
2352 		cache->mfc_flags |= MFC_NOTIFY;
2353 
2354 	err = __ip6mr_fill_mroute(mrt, skb, cache, rtm);
2355 	read_unlock(&mrt_lock);
2356 	return err;
2357 }
2358 
2359 static int ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb,
2360 			     u32 portid, u32 seq, struct mfc6_cache *c, int cmd,
2361 			     int flags)
2362 {
2363 	struct nlmsghdr *nlh;
2364 	struct rtmsg *rtm;
2365 	int err;
2366 
2367 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2368 	if (!nlh)
2369 		return -EMSGSIZE;
2370 
2371 	rtm = nlmsg_data(nlh);
2372 	rtm->rtm_family   = RTNL_FAMILY_IP6MR;
2373 	rtm->rtm_dst_len  = 128;
2374 	rtm->rtm_src_len  = 128;
2375 	rtm->rtm_tos      = 0;
2376 	rtm->rtm_table    = mrt->id;
2377 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2378 		goto nla_put_failure;
2379 	rtm->rtm_type = RTN_MULTICAST;
2380 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2381 	if (c->mfc_flags & MFC_STATIC)
2382 		rtm->rtm_protocol = RTPROT_STATIC;
2383 	else
2384 		rtm->rtm_protocol = RTPROT_MROUTED;
2385 	rtm->rtm_flags    = 0;
2386 
2387 	if (nla_put_in6_addr(skb, RTA_SRC, &c->mf6c_origin) ||
2388 	    nla_put_in6_addr(skb, RTA_DST, &c->mf6c_mcastgrp))
2389 		goto nla_put_failure;
2390 	err = __ip6mr_fill_mroute(mrt, skb, c, rtm);
2391 	/* do not break the dump if cache is unresolved */
2392 	if (err < 0 && err != -ENOENT)
2393 		goto nla_put_failure;
2394 
2395 	nlmsg_end(skb, nlh);
2396 	return 0;
2397 
2398 nla_put_failure:
2399 	nlmsg_cancel(skb, nlh);
2400 	return -EMSGSIZE;
2401 }
2402 
2403 static int mr6_msgsize(bool unresolved, int maxvif)
2404 {
2405 	size_t len =
2406 		NLMSG_ALIGN(sizeof(struct rtmsg))
2407 		+ nla_total_size(4)	/* RTA_TABLE */
2408 		+ nla_total_size(sizeof(struct in6_addr))	/* RTA_SRC */
2409 		+ nla_total_size(sizeof(struct in6_addr))	/* RTA_DST */
2410 		;
2411 
2412 	if (!unresolved)
2413 		len = len
2414 		      + nla_total_size(4)	/* RTA_IIF */
2415 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2416 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2417 						/* RTA_MFC_STATS */
2418 		      + nla_total_size(sizeof(struct rta_mfc_stats))
2419 		;
2420 
2421 	return len;
2422 }
2423 
2424 static void mr6_netlink_event(struct mr6_table *mrt, struct mfc6_cache *mfc,
2425 			      int cmd)
2426 {
2427 	struct net *net = read_pnet(&mrt->net);
2428 	struct sk_buff *skb;
2429 	int err = -ENOBUFS;
2430 
2431 	skb = nlmsg_new(mr6_msgsize(mfc->mf6c_parent >= MAXMIFS, mrt->maxvif),
2432 			GFP_ATOMIC);
2433 	if (!skb)
2434 		goto errout;
2435 
2436 	err = ip6mr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2437 	if (err < 0)
2438 		goto errout;
2439 
2440 	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_MROUTE, NULL, GFP_ATOMIC);
2441 	return;
2442 
2443 errout:
2444 	kfree_skb(skb);
2445 	if (err < 0)
2446 		rtnl_set_sk_err(net, RTNLGRP_IPV6_MROUTE, err);
2447 }
2448 
2449 static int ip6mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2450 {
2451 	struct net *net = sock_net(skb->sk);
2452 	struct mr6_table *mrt;
2453 	struct mfc6_cache *mfc;
2454 	unsigned int t = 0, s_t;
2455 	unsigned int h = 0, s_h;
2456 	unsigned int e = 0, s_e;
2457 
2458 	s_t = cb->args[0];
2459 	s_h = cb->args[1];
2460 	s_e = cb->args[2];
2461 
2462 	read_lock(&mrt_lock);
2463 	ip6mr_for_each_table(mrt, net) {
2464 		if (t < s_t)
2465 			goto next_table;
2466 		if (t > s_t)
2467 			s_h = 0;
2468 		for (h = s_h; h < MFC6_LINES; h++) {
2469 			list_for_each_entry(mfc, &mrt->mfc6_cache_array[h], list) {
2470 				if (e < s_e)
2471 					goto next_entry;
2472 				if (ip6mr_fill_mroute(mrt, skb,
2473 						      NETLINK_CB(cb->skb).portid,
2474 						      cb->nlh->nlmsg_seq,
2475 						      mfc, RTM_NEWROUTE,
2476 						      NLM_F_MULTI) < 0)
2477 					goto done;
2478 next_entry:
2479 				e++;
2480 			}
2481 			e = s_e = 0;
2482 		}
2483 		spin_lock_bh(&mfc_unres_lock);
2484 		list_for_each_entry(mfc, &mrt->mfc6_unres_queue, list) {
2485 			if (e < s_e)
2486 				goto next_entry2;
2487 			if (ip6mr_fill_mroute(mrt, skb,
2488 					      NETLINK_CB(cb->skb).portid,
2489 					      cb->nlh->nlmsg_seq,
2490 					      mfc, RTM_NEWROUTE,
2491 					      NLM_F_MULTI) < 0) {
2492 				spin_unlock_bh(&mfc_unres_lock);
2493 				goto done;
2494 			}
2495 next_entry2:
2496 			e++;
2497 		}
2498 		spin_unlock_bh(&mfc_unres_lock);
2499 		e = s_e = 0;
2500 		s_h = 0;
2501 next_table:
2502 		t++;
2503 	}
2504 done:
2505 	read_unlock(&mrt_lock);
2506 
2507 	cb->args[2] = e;
2508 	cb->args[1] = h;
2509 	cb->args[0] = t;
2510 
2511 	return skb->len;
2512 }
2513