xref: /linux/net/ipv4/ipmr.c (revision cb299ba8b5ef2239429484072fea394cd7581bd7)
1 /*
2  *	IP multicast routing support for mrouted 3.6/3.8
3  *
4  *		(c) 1995 Alan Cox, <alan@lxorguk.ukuu.org.uk>
5  *	  Linux Consultancy and Custom Driver Development
6  *
7  *	This program is free software; you can redistribute it and/or
8  *	modify it under the terms of the GNU General Public License
9  *	as published by the Free Software Foundation; either version
10  *	2 of the License, or (at your option) any later version.
11  *
12  *	Fixes:
13  *	Michael Chastain	:	Incorrect size of copying.
14  *	Alan Cox		:	Added the cache manager code
15  *	Alan Cox		:	Fixed the clone/copy bug and device race.
16  *	Mike McLagan		:	Routing by source
17  *	Malcolm Beattie		:	Buffer handling fixes.
18  *	Alexey Kuznetsov	:	Double buffer free and other fixes.
19  *	SVR Anand		:	Fixed several multicast bugs and problems.
20  *	Alexey Kuznetsov	:	Status, optimisations and more.
21  *	Brad Parker		:	Better behaviour on mrouted upcall
22  *					overflow.
23  *      Carlos Picoto           :       PIMv1 Support
24  *	Pavlin Ivanov Radoslavov:	PIMv2 Registers must checksum only PIM header
25  *					Relax this requirement to work with older peers.
26  *
27  */
28 
29 #include <asm/system.h>
30 #include <asm/uaccess.h>
31 #include <linux/types.h>
32 #include <linux/capability.h>
33 #include <linux/errno.h>
34 #include <linux/timer.h>
35 #include <linux/mm.h>
36 #include <linux/kernel.h>
37 #include <linux/fcntl.h>
38 #include <linux/stat.h>
39 #include <linux/socket.h>
40 #include <linux/in.h>
41 #include <linux/inet.h>
42 #include <linux/netdevice.h>
43 #include <linux/inetdevice.h>
44 #include <linux/igmp.h>
45 #include <linux/proc_fs.h>
46 #include <linux/seq_file.h>
47 #include <linux/mroute.h>
48 #include <linux/init.h>
49 #include <linux/if_ether.h>
50 #include <linux/slab.h>
51 #include <net/net_namespace.h>
52 #include <net/ip.h>
53 #include <net/protocol.h>
54 #include <linux/skbuff.h>
55 #include <net/route.h>
56 #include <net/sock.h>
57 #include <net/icmp.h>
58 #include <net/udp.h>
59 #include <net/raw.h>
60 #include <linux/notifier.h>
61 #include <linux/if_arp.h>
62 #include <linux/netfilter_ipv4.h>
63 #include <net/ipip.h>
64 #include <net/checksum.h>
65 #include <net/netlink.h>
66 #include <net/fib_rules.h>
67 
68 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
69 #define CONFIG_IP_PIMSM	1
70 #endif
71 
72 struct mr_table {
73 	struct list_head	list;
74 #ifdef CONFIG_NET_NS
75 	struct net		*net;
76 #endif
77 	u32			id;
78 	struct sock __rcu	*mroute_sk;
79 	struct timer_list	ipmr_expire_timer;
80 	struct list_head	mfc_unres_queue;
81 	struct list_head	mfc_cache_array[MFC_LINES];
82 	struct vif_device	vif_table[MAXVIFS];
83 	int			maxvif;
84 	atomic_t		cache_resolve_queue_len;
85 	int			mroute_do_assert;
86 	int			mroute_do_pim;
87 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
88 	int			mroute_reg_vif_num;
89 #endif
90 };
91 
92 struct ipmr_rule {
93 	struct fib_rule		common;
94 };
95 
96 struct ipmr_result {
97 	struct mr_table		*mrt;
98 };
99 
100 /* Big lock, protecting vif table, mrt cache and mroute socket state.
101  * Note that the changes are semaphored via rtnl_lock.
102  */
103 
104 static DEFINE_RWLOCK(mrt_lock);
105 
106 /*
107  *	Multicast router control variables
108  */
109 
110 #define VIF_EXISTS(_mrt, _idx) ((_mrt)->vif_table[_idx].dev != NULL)
111 
112 /* Special spinlock for queue of unresolved entries */
113 static DEFINE_SPINLOCK(mfc_unres_lock);
114 
115 /* We return to original Alan's scheme. Hash table of resolved
116  * entries is changed only in process context and protected
117  * with weak lock mrt_lock. Queue of unresolved entries is protected
118  * with strong spinlock mfc_unres_lock.
119  *
120  * In this case data path is free of exclusive locks at all.
121  */
122 
123 static struct kmem_cache *mrt_cachep __read_mostly;
124 
125 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
126 static int ip_mr_forward(struct net *net, struct mr_table *mrt,
127 			 struct sk_buff *skb, struct mfc_cache *cache,
128 			 int local);
129 static int ipmr_cache_report(struct mr_table *mrt,
130 			     struct sk_buff *pkt, vifi_t vifi, int assert);
131 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
132 			      struct mfc_cache *c, struct rtmsg *rtm);
133 static void ipmr_expire_process(unsigned long arg);
134 
135 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
136 #define ipmr_for_each_table(mrt, net) \
137 	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
138 
139 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
140 {
141 	struct mr_table *mrt;
142 
143 	ipmr_for_each_table(mrt, net) {
144 		if (mrt->id == id)
145 			return mrt;
146 	}
147 	return NULL;
148 }
149 
150 static int ipmr_fib_lookup(struct net *net, struct flowi *flp,
151 			   struct mr_table **mrt)
152 {
153 	struct ipmr_result res;
154 	struct fib_lookup_arg arg = { .result = &res, };
155 	int err;
156 
157 	err = fib_rules_lookup(net->ipv4.mr_rules_ops, flp, 0, &arg);
158 	if (err < 0)
159 		return err;
160 	*mrt = res.mrt;
161 	return 0;
162 }
163 
164 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
165 			    int flags, struct fib_lookup_arg *arg)
166 {
167 	struct ipmr_result *res = arg->result;
168 	struct mr_table *mrt;
169 
170 	switch (rule->action) {
171 	case FR_ACT_TO_TBL:
172 		break;
173 	case FR_ACT_UNREACHABLE:
174 		return -ENETUNREACH;
175 	case FR_ACT_PROHIBIT:
176 		return -EACCES;
177 	case FR_ACT_BLACKHOLE:
178 	default:
179 		return -EINVAL;
180 	}
181 
182 	mrt = ipmr_get_table(rule->fr_net, rule->table);
183 	if (mrt == NULL)
184 		return -EAGAIN;
185 	res->mrt = mrt;
186 	return 0;
187 }
188 
189 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
190 {
191 	return 1;
192 }
193 
194 static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
195 	FRA_GENERIC_POLICY,
196 };
197 
198 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
199 			       struct fib_rule_hdr *frh, struct nlattr **tb)
200 {
201 	return 0;
202 }
203 
204 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
205 			     struct nlattr **tb)
206 {
207 	return 1;
208 }
209 
210 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
211 			  struct fib_rule_hdr *frh)
212 {
213 	frh->dst_len = 0;
214 	frh->src_len = 0;
215 	frh->tos     = 0;
216 	return 0;
217 }
218 
219 static const struct fib_rules_ops __net_initdata ipmr_rules_ops_template = {
220 	.family		= RTNL_FAMILY_IPMR,
221 	.rule_size	= sizeof(struct ipmr_rule),
222 	.addr_size	= sizeof(u32),
223 	.action		= ipmr_rule_action,
224 	.match		= ipmr_rule_match,
225 	.configure	= ipmr_rule_configure,
226 	.compare	= ipmr_rule_compare,
227 	.default_pref	= fib_default_rule_pref,
228 	.fill		= ipmr_rule_fill,
229 	.nlgroup	= RTNLGRP_IPV4_RULE,
230 	.policy		= ipmr_rule_policy,
231 	.owner		= THIS_MODULE,
232 };
233 
234 static int __net_init ipmr_rules_init(struct net *net)
235 {
236 	struct fib_rules_ops *ops;
237 	struct mr_table *mrt;
238 	int err;
239 
240 	ops = fib_rules_register(&ipmr_rules_ops_template, net);
241 	if (IS_ERR(ops))
242 		return PTR_ERR(ops);
243 
244 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
245 
246 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
247 	if (mrt == NULL) {
248 		err = -ENOMEM;
249 		goto err1;
250 	}
251 
252 	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
253 	if (err < 0)
254 		goto err2;
255 
256 	net->ipv4.mr_rules_ops = ops;
257 	return 0;
258 
259 err2:
260 	kfree(mrt);
261 err1:
262 	fib_rules_unregister(ops);
263 	return err;
264 }
265 
266 static void __net_exit ipmr_rules_exit(struct net *net)
267 {
268 	struct mr_table *mrt, *next;
269 
270 	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
271 		list_del(&mrt->list);
272 		kfree(mrt);
273 	}
274 	fib_rules_unregister(net->ipv4.mr_rules_ops);
275 }
276 #else
277 #define ipmr_for_each_table(mrt, net) \
278 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
279 
280 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
281 {
282 	return net->ipv4.mrt;
283 }
284 
285 static int ipmr_fib_lookup(struct net *net, struct flowi *flp,
286 			   struct mr_table **mrt)
287 {
288 	*mrt = net->ipv4.mrt;
289 	return 0;
290 }
291 
292 static int __net_init ipmr_rules_init(struct net *net)
293 {
294 	net->ipv4.mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
295 	return net->ipv4.mrt ? 0 : -ENOMEM;
296 }
297 
298 static void __net_exit ipmr_rules_exit(struct net *net)
299 {
300 	kfree(net->ipv4.mrt);
301 }
302 #endif
303 
304 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
305 {
306 	struct mr_table *mrt;
307 	unsigned int i;
308 
309 	mrt = ipmr_get_table(net, id);
310 	if (mrt != NULL)
311 		return mrt;
312 
313 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
314 	if (mrt == NULL)
315 		return NULL;
316 	write_pnet(&mrt->net, net);
317 	mrt->id = id;
318 
319 	/* Forwarding cache */
320 	for (i = 0; i < MFC_LINES; i++)
321 		INIT_LIST_HEAD(&mrt->mfc_cache_array[i]);
322 
323 	INIT_LIST_HEAD(&mrt->mfc_unres_queue);
324 
325 	setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
326 		    (unsigned long)mrt);
327 
328 #ifdef CONFIG_IP_PIMSM
329 	mrt->mroute_reg_vif_num = -1;
330 #endif
331 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
332 	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
333 #endif
334 	return mrt;
335 }
336 
337 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
338 
339 static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
340 {
341 	struct net *net = dev_net(dev);
342 
343 	dev_close(dev);
344 
345 	dev = __dev_get_by_name(net, "tunl0");
346 	if (dev) {
347 		const struct net_device_ops *ops = dev->netdev_ops;
348 		struct ifreq ifr;
349 		struct ip_tunnel_parm p;
350 
351 		memset(&p, 0, sizeof(p));
352 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
353 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
354 		p.iph.version = 4;
355 		p.iph.ihl = 5;
356 		p.iph.protocol = IPPROTO_IPIP;
357 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
358 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
359 
360 		if (ops->ndo_do_ioctl) {
361 			mm_segment_t oldfs = get_fs();
362 
363 			set_fs(KERNEL_DS);
364 			ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
365 			set_fs(oldfs);
366 		}
367 	}
368 }
369 
370 static
371 struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
372 {
373 	struct net_device  *dev;
374 
375 	dev = __dev_get_by_name(net, "tunl0");
376 
377 	if (dev) {
378 		const struct net_device_ops *ops = dev->netdev_ops;
379 		int err;
380 		struct ifreq ifr;
381 		struct ip_tunnel_parm p;
382 		struct in_device  *in_dev;
383 
384 		memset(&p, 0, sizeof(p));
385 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
386 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
387 		p.iph.version = 4;
388 		p.iph.ihl = 5;
389 		p.iph.protocol = IPPROTO_IPIP;
390 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
391 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
392 
393 		if (ops->ndo_do_ioctl) {
394 			mm_segment_t oldfs = get_fs();
395 
396 			set_fs(KERNEL_DS);
397 			err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
398 			set_fs(oldfs);
399 		} else {
400 			err = -EOPNOTSUPP;
401 		}
402 		dev = NULL;
403 
404 		if (err == 0 &&
405 		    (dev = __dev_get_by_name(net, p.name)) != NULL) {
406 			dev->flags |= IFF_MULTICAST;
407 
408 			in_dev = __in_dev_get_rtnl(dev);
409 			if (in_dev == NULL)
410 				goto failure;
411 
412 			ipv4_devconf_setall(in_dev);
413 			IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
414 
415 			if (dev_open(dev))
416 				goto failure;
417 			dev_hold(dev);
418 		}
419 	}
420 	return dev;
421 
422 failure:
423 	/* allow the register to be completed before unregistering. */
424 	rtnl_unlock();
425 	rtnl_lock();
426 
427 	unregister_netdevice(dev);
428 	return NULL;
429 }
430 
431 #ifdef CONFIG_IP_PIMSM
432 
433 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
434 {
435 	struct net *net = dev_net(dev);
436 	struct mr_table *mrt;
437 	struct flowi fl = {
438 		.oif		= dev->ifindex,
439 		.iif		= skb->skb_iif,
440 		.mark		= skb->mark,
441 	};
442 	int err;
443 
444 	err = ipmr_fib_lookup(net, &fl, &mrt);
445 	if (err < 0) {
446 		kfree_skb(skb);
447 		return err;
448 	}
449 
450 	read_lock(&mrt_lock);
451 	dev->stats.tx_bytes += skb->len;
452 	dev->stats.tx_packets++;
453 	ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
454 	read_unlock(&mrt_lock);
455 	kfree_skb(skb);
456 	return NETDEV_TX_OK;
457 }
458 
459 static const struct net_device_ops reg_vif_netdev_ops = {
460 	.ndo_start_xmit	= reg_vif_xmit,
461 };
462 
463 static void reg_vif_setup(struct net_device *dev)
464 {
465 	dev->type		= ARPHRD_PIMREG;
466 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
467 	dev->flags		= IFF_NOARP;
468 	dev->netdev_ops		= &reg_vif_netdev_ops,
469 	dev->destructor		= free_netdev;
470 	dev->features		|= NETIF_F_NETNS_LOCAL;
471 }
472 
473 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
474 {
475 	struct net_device *dev;
476 	struct in_device *in_dev;
477 	char name[IFNAMSIZ];
478 
479 	if (mrt->id == RT_TABLE_DEFAULT)
480 		sprintf(name, "pimreg");
481 	else
482 		sprintf(name, "pimreg%u", mrt->id);
483 
484 	dev = alloc_netdev(0, name, reg_vif_setup);
485 
486 	if (dev == NULL)
487 		return NULL;
488 
489 	dev_net_set(dev, net);
490 
491 	if (register_netdevice(dev)) {
492 		free_netdev(dev);
493 		return NULL;
494 	}
495 	dev->iflink = 0;
496 
497 	rcu_read_lock();
498 	in_dev = __in_dev_get_rcu(dev);
499 	if (!in_dev) {
500 		rcu_read_unlock();
501 		goto failure;
502 	}
503 
504 	ipv4_devconf_setall(in_dev);
505 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
506 	rcu_read_unlock();
507 
508 	if (dev_open(dev))
509 		goto failure;
510 
511 	dev_hold(dev);
512 
513 	return dev;
514 
515 failure:
516 	/* allow the register to be completed before unregistering. */
517 	rtnl_unlock();
518 	rtnl_lock();
519 
520 	unregister_netdevice(dev);
521 	return NULL;
522 }
523 #endif
524 
525 /*
526  *	Delete a VIF entry
527  *	@notify: Set to 1, if the caller is a notifier_call
528  */
529 
530 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
531 		      struct list_head *head)
532 {
533 	struct vif_device *v;
534 	struct net_device *dev;
535 	struct in_device *in_dev;
536 
537 	if (vifi < 0 || vifi >= mrt->maxvif)
538 		return -EADDRNOTAVAIL;
539 
540 	v = &mrt->vif_table[vifi];
541 
542 	write_lock_bh(&mrt_lock);
543 	dev = v->dev;
544 	v->dev = NULL;
545 
546 	if (!dev) {
547 		write_unlock_bh(&mrt_lock);
548 		return -EADDRNOTAVAIL;
549 	}
550 
551 #ifdef CONFIG_IP_PIMSM
552 	if (vifi == mrt->mroute_reg_vif_num)
553 		mrt->mroute_reg_vif_num = -1;
554 #endif
555 
556 	if (vifi + 1 == mrt->maxvif) {
557 		int tmp;
558 
559 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
560 			if (VIF_EXISTS(mrt, tmp))
561 				break;
562 		}
563 		mrt->maxvif = tmp+1;
564 	}
565 
566 	write_unlock_bh(&mrt_lock);
567 
568 	dev_set_allmulti(dev, -1);
569 
570 	in_dev = __in_dev_get_rtnl(dev);
571 	if (in_dev) {
572 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
573 		ip_rt_multicast_event(in_dev);
574 	}
575 
576 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
577 		unregister_netdevice_queue(dev, head);
578 
579 	dev_put(dev);
580 	return 0;
581 }
582 
583 static void ipmr_cache_free_rcu(struct rcu_head *head)
584 {
585 	struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
586 
587 	kmem_cache_free(mrt_cachep, c);
588 }
589 
590 static inline void ipmr_cache_free(struct mfc_cache *c)
591 {
592 	call_rcu(&c->rcu, ipmr_cache_free_rcu);
593 }
594 
595 /* Destroy an unresolved cache entry, killing queued skbs
596  * and reporting error to netlink readers.
597  */
598 
599 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
600 {
601 	struct net *net = read_pnet(&mrt->net);
602 	struct sk_buff *skb;
603 	struct nlmsgerr *e;
604 
605 	atomic_dec(&mrt->cache_resolve_queue_len);
606 
607 	while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
608 		if (ip_hdr(skb)->version == 0) {
609 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
610 			nlh->nlmsg_type = NLMSG_ERROR;
611 			nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
612 			skb_trim(skb, nlh->nlmsg_len);
613 			e = NLMSG_DATA(nlh);
614 			e->error = -ETIMEDOUT;
615 			memset(&e->msg, 0, sizeof(e->msg));
616 
617 			rtnl_unicast(skb, net, NETLINK_CB(skb).pid);
618 		} else {
619 			kfree_skb(skb);
620 		}
621 	}
622 
623 	ipmr_cache_free(c);
624 }
625 
626 
627 /* Timer process for the unresolved queue. */
628 
629 static void ipmr_expire_process(unsigned long arg)
630 {
631 	struct mr_table *mrt = (struct mr_table *)arg;
632 	unsigned long now;
633 	unsigned long expires;
634 	struct mfc_cache *c, *next;
635 
636 	if (!spin_trylock(&mfc_unres_lock)) {
637 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
638 		return;
639 	}
640 
641 	if (list_empty(&mrt->mfc_unres_queue))
642 		goto out;
643 
644 	now = jiffies;
645 	expires = 10*HZ;
646 
647 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
648 		if (time_after(c->mfc_un.unres.expires, now)) {
649 			unsigned long interval = c->mfc_un.unres.expires - now;
650 			if (interval < expires)
651 				expires = interval;
652 			continue;
653 		}
654 
655 		list_del(&c->list);
656 		ipmr_destroy_unres(mrt, c);
657 	}
658 
659 	if (!list_empty(&mrt->mfc_unres_queue))
660 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
661 
662 out:
663 	spin_unlock(&mfc_unres_lock);
664 }
665 
666 /* Fill oifs list. It is called under write locked mrt_lock. */
667 
668 static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
669 				   unsigned char *ttls)
670 {
671 	int vifi;
672 
673 	cache->mfc_un.res.minvif = MAXVIFS;
674 	cache->mfc_un.res.maxvif = 0;
675 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
676 
677 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
678 		if (VIF_EXISTS(mrt, vifi) &&
679 		    ttls[vifi] && ttls[vifi] < 255) {
680 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
681 			if (cache->mfc_un.res.minvif > vifi)
682 				cache->mfc_un.res.minvif = vifi;
683 			if (cache->mfc_un.res.maxvif <= vifi)
684 				cache->mfc_un.res.maxvif = vifi + 1;
685 		}
686 	}
687 }
688 
689 static int vif_add(struct net *net, struct mr_table *mrt,
690 		   struct vifctl *vifc, int mrtsock)
691 {
692 	int vifi = vifc->vifc_vifi;
693 	struct vif_device *v = &mrt->vif_table[vifi];
694 	struct net_device *dev;
695 	struct in_device *in_dev;
696 	int err;
697 
698 	/* Is vif busy ? */
699 	if (VIF_EXISTS(mrt, vifi))
700 		return -EADDRINUSE;
701 
702 	switch (vifc->vifc_flags) {
703 #ifdef CONFIG_IP_PIMSM
704 	case VIFF_REGISTER:
705 		/*
706 		 * Special Purpose VIF in PIM
707 		 * All the packets will be sent to the daemon
708 		 */
709 		if (mrt->mroute_reg_vif_num >= 0)
710 			return -EADDRINUSE;
711 		dev = ipmr_reg_vif(net, mrt);
712 		if (!dev)
713 			return -ENOBUFS;
714 		err = dev_set_allmulti(dev, 1);
715 		if (err) {
716 			unregister_netdevice(dev);
717 			dev_put(dev);
718 			return err;
719 		}
720 		break;
721 #endif
722 	case VIFF_TUNNEL:
723 		dev = ipmr_new_tunnel(net, vifc);
724 		if (!dev)
725 			return -ENOBUFS;
726 		err = dev_set_allmulti(dev, 1);
727 		if (err) {
728 			ipmr_del_tunnel(dev, vifc);
729 			dev_put(dev);
730 			return err;
731 		}
732 		break;
733 
734 	case VIFF_USE_IFINDEX:
735 	case 0:
736 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
737 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
738 			if (dev && __in_dev_get_rtnl(dev) == NULL) {
739 				dev_put(dev);
740 				return -EADDRNOTAVAIL;
741 			}
742 		} else {
743 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
744 		}
745 		if (!dev)
746 			return -EADDRNOTAVAIL;
747 		err = dev_set_allmulti(dev, 1);
748 		if (err) {
749 			dev_put(dev);
750 			return err;
751 		}
752 		break;
753 	default:
754 		return -EINVAL;
755 	}
756 
757 	in_dev = __in_dev_get_rtnl(dev);
758 	if (!in_dev) {
759 		dev_put(dev);
760 		return -EADDRNOTAVAIL;
761 	}
762 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
763 	ip_rt_multicast_event(in_dev);
764 
765 	/* Fill in the VIF structures */
766 
767 	v->rate_limit = vifc->vifc_rate_limit;
768 	v->local = vifc->vifc_lcl_addr.s_addr;
769 	v->remote = vifc->vifc_rmt_addr.s_addr;
770 	v->flags = vifc->vifc_flags;
771 	if (!mrtsock)
772 		v->flags |= VIFF_STATIC;
773 	v->threshold = vifc->vifc_threshold;
774 	v->bytes_in = 0;
775 	v->bytes_out = 0;
776 	v->pkt_in = 0;
777 	v->pkt_out = 0;
778 	v->link = dev->ifindex;
779 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
780 		v->link = dev->iflink;
781 
782 	/* And finish update writing critical data */
783 	write_lock_bh(&mrt_lock);
784 	v->dev = dev;
785 #ifdef CONFIG_IP_PIMSM
786 	if (v->flags & VIFF_REGISTER)
787 		mrt->mroute_reg_vif_num = vifi;
788 #endif
789 	if (vifi+1 > mrt->maxvif)
790 		mrt->maxvif = vifi+1;
791 	write_unlock_bh(&mrt_lock);
792 	return 0;
793 }
794 
795 /* called with rcu_read_lock() */
796 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
797 					 __be32 origin,
798 					 __be32 mcastgrp)
799 {
800 	int line = MFC_HASH(mcastgrp, origin);
801 	struct mfc_cache *c;
802 
803 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list) {
804 		if (c->mfc_origin == origin && c->mfc_mcastgrp == mcastgrp)
805 			return c;
806 	}
807 	return NULL;
808 }
809 
810 /*
811  *	Allocate a multicast cache entry
812  */
813 static struct mfc_cache *ipmr_cache_alloc(void)
814 {
815 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
816 
817 	if (c)
818 		c->mfc_un.res.minvif = MAXVIFS;
819 	return c;
820 }
821 
822 static struct mfc_cache *ipmr_cache_alloc_unres(void)
823 {
824 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
825 
826 	if (c) {
827 		skb_queue_head_init(&c->mfc_un.unres.unresolved);
828 		c->mfc_un.unres.expires = jiffies + 10*HZ;
829 	}
830 	return c;
831 }
832 
833 /*
834  *	A cache entry has gone into a resolved state from queued
835  */
836 
837 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
838 			       struct mfc_cache *uc, struct mfc_cache *c)
839 {
840 	struct sk_buff *skb;
841 	struct nlmsgerr *e;
842 
843 	/* Play the pending entries through our router */
844 
845 	while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
846 		if (ip_hdr(skb)->version == 0) {
847 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
848 
849 			if (__ipmr_fill_mroute(mrt, skb, c, NLMSG_DATA(nlh)) > 0) {
850 				nlh->nlmsg_len = skb_tail_pointer(skb) -
851 						 (u8 *)nlh;
852 			} else {
853 				nlh->nlmsg_type = NLMSG_ERROR;
854 				nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
855 				skb_trim(skb, nlh->nlmsg_len);
856 				e = NLMSG_DATA(nlh);
857 				e->error = -EMSGSIZE;
858 				memset(&e->msg, 0, sizeof(e->msg));
859 			}
860 
861 			rtnl_unicast(skb, net, NETLINK_CB(skb).pid);
862 		} else {
863 			ip_mr_forward(net, mrt, skb, c, 0);
864 		}
865 	}
866 }
867 
868 /*
869  *	Bounce a cache query up to mrouted. We could use netlink for this but mrouted
870  *	expects the following bizarre scheme.
871  *
872  *	Called under mrt_lock.
873  */
874 
875 static int ipmr_cache_report(struct mr_table *mrt,
876 			     struct sk_buff *pkt, vifi_t vifi, int assert)
877 {
878 	struct sk_buff *skb;
879 	const int ihl = ip_hdrlen(pkt);
880 	struct igmphdr *igmp;
881 	struct igmpmsg *msg;
882 	struct sock *mroute_sk;
883 	int ret;
884 
885 #ifdef CONFIG_IP_PIMSM
886 	if (assert == IGMPMSG_WHOLEPKT)
887 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
888 	else
889 #endif
890 		skb = alloc_skb(128, GFP_ATOMIC);
891 
892 	if (!skb)
893 		return -ENOBUFS;
894 
895 #ifdef CONFIG_IP_PIMSM
896 	if (assert == IGMPMSG_WHOLEPKT) {
897 		/* Ugly, but we have no choice with this interface.
898 		 * Duplicate old header, fix ihl, length etc.
899 		 * And all this only to mangle msg->im_msgtype and
900 		 * to set msg->im_mbz to "mbz" :-)
901 		 */
902 		skb_push(skb, sizeof(struct iphdr));
903 		skb_reset_network_header(skb);
904 		skb_reset_transport_header(skb);
905 		msg = (struct igmpmsg *)skb_network_header(skb);
906 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
907 		msg->im_msgtype = IGMPMSG_WHOLEPKT;
908 		msg->im_mbz = 0;
909 		msg->im_vif = mrt->mroute_reg_vif_num;
910 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
911 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
912 					     sizeof(struct iphdr));
913 	} else
914 #endif
915 	{
916 
917 	/* Copy the IP header */
918 
919 	skb->network_header = skb->tail;
920 	skb_put(skb, ihl);
921 	skb_copy_to_linear_data(skb, pkt->data, ihl);
922 	ip_hdr(skb)->protocol = 0;	/* Flag to the kernel this is a route add */
923 	msg = (struct igmpmsg *)skb_network_header(skb);
924 	msg->im_vif = vifi;
925 	skb_dst_set(skb, dst_clone(skb_dst(pkt)));
926 
927 	/* Add our header */
928 
929 	igmp = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
930 	igmp->type	=
931 	msg->im_msgtype = assert;
932 	igmp->code	= 0;
933 	ip_hdr(skb)->tot_len = htons(skb->len);		/* Fix the length */
934 	skb->transport_header = skb->network_header;
935 	}
936 
937 	rcu_read_lock();
938 	mroute_sk = rcu_dereference(mrt->mroute_sk);
939 	if (mroute_sk == NULL) {
940 		rcu_read_unlock();
941 		kfree_skb(skb);
942 		return -EINVAL;
943 	}
944 
945 	/* Deliver to mrouted */
946 
947 	ret = sock_queue_rcv_skb(mroute_sk, skb);
948 	rcu_read_unlock();
949 	if (ret < 0) {
950 		if (net_ratelimit())
951 			printk(KERN_WARNING "mroute: pending queue full, dropping entries.\n");
952 		kfree_skb(skb);
953 	}
954 
955 	return ret;
956 }
957 
958 /*
959  *	Queue a packet for resolution. It gets locked cache entry!
960  */
961 
962 static int
963 ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi, struct sk_buff *skb)
964 {
965 	bool found = false;
966 	int err;
967 	struct mfc_cache *c;
968 	const struct iphdr *iph = ip_hdr(skb);
969 
970 	spin_lock_bh(&mfc_unres_lock);
971 	list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
972 		if (c->mfc_mcastgrp == iph->daddr &&
973 		    c->mfc_origin == iph->saddr) {
974 			found = true;
975 			break;
976 		}
977 	}
978 
979 	if (!found) {
980 		/* Create a new entry if allowable */
981 
982 		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
983 		    (c = ipmr_cache_alloc_unres()) == NULL) {
984 			spin_unlock_bh(&mfc_unres_lock);
985 
986 			kfree_skb(skb);
987 			return -ENOBUFS;
988 		}
989 
990 		/* Fill in the new cache entry */
991 
992 		c->mfc_parent	= -1;
993 		c->mfc_origin	= iph->saddr;
994 		c->mfc_mcastgrp	= iph->daddr;
995 
996 		/* Reflect first query at mrouted. */
997 
998 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
999 		if (err < 0) {
1000 			/* If the report failed throw the cache entry
1001 			   out - Brad Parker
1002 			 */
1003 			spin_unlock_bh(&mfc_unres_lock);
1004 
1005 			ipmr_cache_free(c);
1006 			kfree_skb(skb);
1007 			return err;
1008 		}
1009 
1010 		atomic_inc(&mrt->cache_resolve_queue_len);
1011 		list_add(&c->list, &mrt->mfc_unres_queue);
1012 
1013 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1014 			mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1015 	}
1016 
1017 	/* See if we can append the packet */
1018 
1019 	if (c->mfc_un.unres.unresolved.qlen > 3) {
1020 		kfree_skb(skb);
1021 		err = -ENOBUFS;
1022 	} else {
1023 		skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1024 		err = 0;
1025 	}
1026 
1027 	spin_unlock_bh(&mfc_unres_lock);
1028 	return err;
1029 }
1030 
1031 /*
1032  *	MFC cache manipulation by user space mroute daemon
1033  */
1034 
1035 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc)
1036 {
1037 	int line;
1038 	struct mfc_cache *c, *next;
1039 
1040 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1041 
1042 	list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[line], list) {
1043 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1044 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
1045 			list_del_rcu(&c->list);
1046 
1047 			ipmr_cache_free(c);
1048 			return 0;
1049 		}
1050 	}
1051 	return -ENOENT;
1052 }
1053 
1054 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1055 			struct mfcctl *mfc, int mrtsock)
1056 {
1057 	bool found = false;
1058 	int line;
1059 	struct mfc_cache *uc, *c;
1060 
1061 	if (mfc->mfcc_parent >= MAXVIFS)
1062 		return -ENFILE;
1063 
1064 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1065 
1066 	list_for_each_entry(c, &mrt->mfc_cache_array[line], list) {
1067 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1068 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
1069 			found = true;
1070 			break;
1071 		}
1072 	}
1073 
1074 	if (found) {
1075 		write_lock_bh(&mrt_lock);
1076 		c->mfc_parent = mfc->mfcc_parent;
1077 		ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1078 		if (!mrtsock)
1079 			c->mfc_flags |= MFC_STATIC;
1080 		write_unlock_bh(&mrt_lock);
1081 		return 0;
1082 	}
1083 
1084 	if (!ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1085 		return -EINVAL;
1086 
1087 	c = ipmr_cache_alloc();
1088 	if (c == NULL)
1089 		return -ENOMEM;
1090 
1091 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1092 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1093 	c->mfc_parent = mfc->mfcc_parent;
1094 	ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1095 	if (!mrtsock)
1096 		c->mfc_flags |= MFC_STATIC;
1097 
1098 	list_add_rcu(&c->list, &mrt->mfc_cache_array[line]);
1099 
1100 	/*
1101 	 *	Check to see if we resolved a queued list. If so we
1102 	 *	need to send on the frames and tidy up.
1103 	 */
1104 	found = false;
1105 	spin_lock_bh(&mfc_unres_lock);
1106 	list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1107 		if (uc->mfc_origin == c->mfc_origin &&
1108 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1109 			list_del(&uc->list);
1110 			atomic_dec(&mrt->cache_resolve_queue_len);
1111 			found = true;
1112 			break;
1113 		}
1114 	}
1115 	if (list_empty(&mrt->mfc_unres_queue))
1116 		del_timer(&mrt->ipmr_expire_timer);
1117 	spin_unlock_bh(&mfc_unres_lock);
1118 
1119 	if (found) {
1120 		ipmr_cache_resolve(net, mrt, uc, c);
1121 		ipmr_cache_free(uc);
1122 	}
1123 	return 0;
1124 }
1125 
1126 /*
1127  *	Close the multicast socket, and clear the vif tables etc
1128  */
1129 
1130 static void mroute_clean_tables(struct mr_table *mrt)
1131 {
1132 	int i;
1133 	LIST_HEAD(list);
1134 	struct mfc_cache *c, *next;
1135 
1136 	/* Shut down all active vif entries */
1137 
1138 	for (i = 0; i < mrt->maxvif; i++) {
1139 		if (!(mrt->vif_table[i].flags & VIFF_STATIC))
1140 			vif_delete(mrt, i, 0, &list);
1141 	}
1142 	unregister_netdevice_many(&list);
1143 
1144 	/* Wipe the cache */
1145 
1146 	for (i = 0; i < MFC_LINES; i++) {
1147 		list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[i], list) {
1148 			if (c->mfc_flags & MFC_STATIC)
1149 				continue;
1150 			list_del_rcu(&c->list);
1151 			ipmr_cache_free(c);
1152 		}
1153 	}
1154 
1155 	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1156 		spin_lock_bh(&mfc_unres_lock);
1157 		list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
1158 			list_del(&c->list);
1159 			ipmr_destroy_unres(mrt, c);
1160 		}
1161 		spin_unlock_bh(&mfc_unres_lock);
1162 	}
1163 }
1164 
1165 /* called from ip_ra_control(), before an RCU grace period,
1166  * we dont need to call synchronize_rcu() here
1167  */
1168 static void mrtsock_destruct(struct sock *sk)
1169 {
1170 	struct net *net = sock_net(sk);
1171 	struct mr_table *mrt;
1172 
1173 	rtnl_lock();
1174 	ipmr_for_each_table(mrt, net) {
1175 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1176 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1177 			rcu_assign_pointer(mrt->mroute_sk, NULL);
1178 			mroute_clean_tables(mrt);
1179 		}
1180 	}
1181 	rtnl_unlock();
1182 }
1183 
1184 /*
1185  *	Socket options and virtual interface manipulation. The whole
1186  *	virtual interface system is a complete heap, but unfortunately
1187  *	that's how BSD mrouted happens to think. Maybe one day with a proper
1188  *	MOSPF/PIM router set up we can clean this up.
1189  */
1190 
1191 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen)
1192 {
1193 	int ret;
1194 	struct vifctl vif;
1195 	struct mfcctl mfc;
1196 	struct net *net = sock_net(sk);
1197 	struct mr_table *mrt;
1198 
1199 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1200 	if (mrt == NULL)
1201 		return -ENOENT;
1202 
1203 	if (optname != MRT_INIT) {
1204 		if (sk != rcu_dereference_raw(mrt->mroute_sk) &&
1205 		    !capable(CAP_NET_ADMIN))
1206 			return -EACCES;
1207 	}
1208 
1209 	switch (optname) {
1210 	case MRT_INIT:
1211 		if (sk->sk_type != SOCK_RAW ||
1212 		    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1213 			return -EOPNOTSUPP;
1214 		if (optlen != sizeof(int))
1215 			return -ENOPROTOOPT;
1216 
1217 		rtnl_lock();
1218 		if (rtnl_dereference(mrt->mroute_sk)) {
1219 			rtnl_unlock();
1220 			return -EADDRINUSE;
1221 		}
1222 
1223 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1224 		if (ret == 0) {
1225 			rcu_assign_pointer(mrt->mroute_sk, sk);
1226 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1227 		}
1228 		rtnl_unlock();
1229 		return ret;
1230 	case MRT_DONE:
1231 		if (sk != rcu_dereference_raw(mrt->mroute_sk))
1232 			return -EACCES;
1233 		return ip_ra_control(sk, 0, NULL);
1234 	case MRT_ADD_VIF:
1235 	case MRT_DEL_VIF:
1236 		if (optlen != sizeof(vif))
1237 			return -EINVAL;
1238 		if (copy_from_user(&vif, optval, sizeof(vif)))
1239 			return -EFAULT;
1240 		if (vif.vifc_vifi >= MAXVIFS)
1241 			return -ENFILE;
1242 		rtnl_lock();
1243 		if (optname == MRT_ADD_VIF) {
1244 			ret = vif_add(net, mrt, &vif,
1245 				      sk == rtnl_dereference(mrt->mroute_sk));
1246 		} else {
1247 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1248 		}
1249 		rtnl_unlock();
1250 		return ret;
1251 
1252 		/*
1253 		 *	Manipulate the forwarding caches. These live
1254 		 *	in a sort of kernel/user symbiosis.
1255 		 */
1256 	case MRT_ADD_MFC:
1257 	case MRT_DEL_MFC:
1258 		if (optlen != sizeof(mfc))
1259 			return -EINVAL;
1260 		if (copy_from_user(&mfc, optval, sizeof(mfc)))
1261 			return -EFAULT;
1262 		rtnl_lock();
1263 		if (optname == MRT_DEL_MFC)
1264 			ret = ipmr_mfc_delete(mrt, &mfc);
1265 		else
1266 			ret = ipmr_mfc_add(net, mrt, &mfc,
1267 					   sk == rtnl_dereference(mrt->mroute_sk));
1268 		rtnl_unlock();
1269 		return ret;
1270 		/*
1271 		 *	Control PIM assert.
1272 		 */
1273 	case MRT_ASSERT:
1274 	{
1275 		int v;
1276 		if (get_user(v, (int __user *)optval))
1277 			return -EFAULT;
1278 		mrt->mroute_do_assert = (v) ? 1 : 0;
1279 		return 0;
1280 	}
1281 #ifdef CONFIG_IP_PIMSM
1282 	case MRT_PIM:
1283 	{
1284 		int v;
1285 
1286 		if (get_user(v, (int __user *)optval))
1287 			return -EFAULT;
1288 		v = (v) ? 1 : 0;
1289 
1290 		rtnl_lock();
1291 		ret = 0;
1292 		if (v != mrt->mroute_do_pim) {
1293 			mrt->mroute_do_pim = v;
1294 			mrt->mroute_do_assert = v;
1295 		}
1296 		rtnl_unlock();
1297 		return ret;
1298 	}
1299 #endif
1300 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
1301 	case MRT_TABLE:
1302 	{
1303 		u32 v;
1304 
1305 		if (optlen != sizeof(u32))
1306 			return -EINVAL;
1307 		if (get_user(v, (u32 __user *)optval))
1308 			return -EFAULT;
1309 
1310 		rtnl_lock();
1311 		ret = 0;
1312 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1313 			ret = -EBUSY;
1314 		} else {
1315 			if (!ipmr_new_table(net, v))
1316 				ret = -ENOMEM;
1317 			raw_sk(sk)->ipmr_table = v;
1318 		}
1319 		rtnl_unlock();
1320 		return ret;
1321 	}
1322 #endif
1323 	/*
1324 	 *	Spurious command, or MRT_VERSION which you cannot
1325 	 *	set.
1326 	 */
1327 	default:
1328 		return -ENOPROTOOPT;
1329 	}
1330 }
1331 
1332 /*
1333  *	Getsock opt support for the multicast routing system.
1334  */
1335 
1336 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1337 {
1338 	int olr;
1339 	int val;
1340 	struct net *net = sock_net(sk);
1341 	struct mr_table *mrt;
1342 
1343 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1344 	if (mrt == NULL)
1345 		return -ENOENT;
1346 
1347 	if (optname != MRT_VERSION &&
1348 #ifdef CONFIG_IP_PIMSM
1349 	   optname != MRT_PIM &&
1350 #endif
1351 	   optname != MRT_ASSERT)
1352 		return -ENOPROTOOPT;
1353 
1354 	if (get_user(olr, optlen))
1355 		return -EFAULT;
1356 
1357 	olr = min_t(unsigned int, olr, sizeof(int));
1358 	if (olr < 0)
1359 		return -EINVAL;
1360 
1361 	if (put_user(olr, optlen))
1362 		return -EFAULT;
1363 	if (optname == MRT_VERSION)
1364 		val = 0x0305;
1365 #ifdef CONFIG_IP_PIMSM
1366 	else if (optname == MRT_PIM)
1367 		val = mrt->mroute_do_pim;
1368 #endif
1369 	else
1370 		val = mrt->mroute_do_assert;
1371 	if (copy_to_user(optval, &val, olr))
1372 		return -EFAULT;
1373 	return 0;
1374 }
1375 
1376 /*
1377  *	The IP multicast ioctl support routines.
1378  */
1379 
1380 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1381 {
1382 	struct sioc_sg_req sr;
1383 	struct sioc_vif_req vr;
1384 	struct vif_device *vif;
1385 	struct mfc_cache *c;
1386 	struct net *net = sock_net(sk);
1387 	struct mr_table *mrt;
1388 
1389 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1390 	if (mrt == NULL)
1391 		return -ENOENT;
1392 
1393 	switch (cmd) {
1394 	case SIOCGETVIFCNT:
1395 		if (copy_from_user(&vr, arg, sizeof(vr)))
1396 			return -EFAULT;
1397 		if (vr.vifi >= mrt->maxvif)
1398 			return -EINVAL;
1399 		read_lock(&mrt_lock);
1400 		vif = &mrt->vif_table[vr.vifi];
1401 		if (VIF_EXISTS(mrt, vr.vifi)) {
1402 			vr.icount = vif->pkt_in;
1403 			vr.ocount = vif->pkt_out;
1404 			vr.ibytes = vif->bytes_in;
1405 			vr.obytes = vif->bytes_out;
1406 			read_unlock(&mrt_lock);
1407 
1408 			if (copy_to_user(arg, &vr, sizeof(vr)))
1409 				return -EFAULT;
1410 			return 0;
1411 		}
1412 		read_unlock(&mrt_lock);
1413 		return -EADDRNOTAVAIL;
1414 	case SIOCGETSGCNT:
1415 		if (copy_from_user(&sr, arg, sizeof(sr)))
1416 			return -EFAULT;
1417 
1418 		rcu_read_lock();
1419 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1420 		if (c) {
1421 			sr.pktcnt = c->mfc_un.res.pkt;
1422 			sr.bytecnt = c->mfc_un.res.bytes;
1423 			sr.wrong_if = c->mfc_un.res.wrong_if;
1424 			rcu_read_unlock();
1425 
1426 			if (copy_to_user(arg, &sr, sizeof(sr)))
1427 				return -EFAULT;
1428 			return 0;
1429 		}
1430 		rcu_read_unlock();
1431 		return -EADDRNOTAVAIL;
1432 	default:
1433 		return -ENOIOCTLCMD;
1434 	}
1435 }
1436 
1437 
1438 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1439 {
1440 	struct net_device *dev = ptr;
1441 	struct net *net = dev_net(dev);
1442 	struct mr_table *mrt;
1443 	struct vif_device *v;
1444 	int ct;
1445 	LIST_HEAD(list);
1446 
1447 	if (event != NETDEV_UNREGISTER)
1448 		return NOTIFY_DONE;
1449 
1450 	ipmr_for_each_table(mrt, net) {
1451 		v = &mrt->vif_table[0];
1452 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1453 			if (v->dev == dev)
1454 				vif_delete(mrt, ct, 1, &list);
1455 		}
1456 	}
1457 	unregister_netdevice_many(&list);
1458 	return NOTIFY_DONE;
1459 }
1460 
1461 
1462 static struct notifier_block ip_mr_notifier = {
1463 	.notifier_call = ipmr_device_event,
1464 };
1465 
1466 /*
1467  *	Encapsulate a packet by attaching a valid IPIP header to it.
1468  *	This avoids tunnel drivers and other mess and gives us the speed so
1469  *	important for multicast video.
1470  */
1471 
1472 static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr)
1473 {
1474 	struct iphdr *iph;
1475 	struct iphdr *old_iph = ip_hdr(skb);
1476 
1477 	skb_push(skb, sizeof(struct iphdr));
1478 	skb->transport_header = skb->network_header;
1479 	skb_reset_network_header(skb);
1480 	iph = ip_hdr(skb);
1481 
1482 	iph->version	=	4;
1483 	iph->tos	=	old_iph->tos;
1484 	iph->ttl	=	old_iph->ttl;
1485 	iph->frag_off	=	0;
1486 	iph->daddr	=	daddr;
1487 	iph->saddr	=	saddr;
1488 	iph->protocol	=	IPPROTO_IPIP;
1489 	iph->ihl	=	5;
1490 	iph->tot_len	=	htons(skb->len);
1491 	ip_select_ident(iph, skb_dst(skb), NULL);
1492 	ip_send_check(iph);
1493 
1494 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1495 	nf_reset(skb);
1496 }
1497 
1498 static inline int ipmr_forward_finish(struct sk_buff *skb)
1499 {
1500 	struct ip_options *opt = &(IPCB(skb)->opt);
1501 
1502 	IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
1503 
1504 	if (unlikely(opt->optlen))
1505 		ip_forward_options(skb);
1506 
1507 	return dst_output(skb);
1508 }
1509 
1510 /*
1511  *	Processing handlers for ipmr_forward
1512  */
1513 
1514 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1515 			    struct sk_buff *skb, struct mfc_cache *c, int vifi)
1516 {
1517 	const struct iphdr *iph = ip_hdr(skb);
1518 	struct vif_device *vif = &mrt->vif_table[vifi];
1519 	struct net_device *dev;
1520 	struct rtable *rt;
1521 	int    encap = 0;
1522 
1523 	if (vif->dev == NULL)
1524 		goto out_free;
1525 
1526 #ifdef CONFIG_IP_PIMSM
1527 	if (vif->flags & VIFF_REGISTER) {
1528 		vif->pkt_out++;
1529 		vif->bytes_out += skb->len;
1530 		vif->dev->stats.tx_bytes += skb->len;
1531 		vif->dev->stats.tx_packets++;
1532 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1533 		goto out_free;
1534 	}
1535 #endif
1536 
1537 	if (vif->flags & VIFF_TUNNEL) {
1538 		struct flowi fl = {
1539 			.oif = vif->link,
1540 			.nl_u = {
1541 				.ip4_u = {
1542 					.daddr = vif->remote,
1543 					.saddr = vif->local,
1544 					.tos = RT_TOS(iph->tos)
1545 				}
1546 			},
1547 			.proto = IPPROTO_IPIP
1548 		};
1549 
1550 		if (ip_route_output_key(net, &rt, &fl))
1551 			goto out_free;
1552 		encap = sizeof(struct iphdr);
1553 	} else {
1554 		struct flowi fl = {
1555 			.oif = vif->link,
1556 			.nl_u = {
1557 				.ip4_u = {
1558 					.daddr = iph->daddr,
1559 					.tos = RT_TOS(iph->tos)
1560 				}
1561 			},
1562 			.proto = IPPROTO_IPIP
1563 		};
1564 
1565 		if (ip_route_output_key(net, &rt, &fl))
1566 			goto out_free;
1567 	}
1568 
1569 	dev = rt->dst.dev;
1570 
1571 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1572 		/* Do not fragment multicasts. Alas, IPv4 does not
1573 		 * allow to send ICMP, so that packets will disappear
1574 		 * to blackhole.
1575 		 */
1576 
1577 		IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
1578 		ip_rt_put(rt);
1579 		goto out_free;
1580 	}
1581 
1582 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1583 
1584 	if (skb_cow(skb, encap)) {
1585 		ip_rt_put(rt);
1586 		goto out_free;
1587 	}
1588 
1589 	vif->pkt_out++;
1590 	vif->bytes_out += skb->len;
1591 
1592 	skb_dst_drop(skb);
1593 	skb_dst_set(skb, &rt->dst);
1594 	ip_decrease_ttl(ip_hdr(skb));
1595 
1596 	/* FIXME: forward and output firewalls used to be called here.
1597 	 * What do we do with netfilter? -- RR
1598 	 */
1599 	if (vif->flags & VIFF_TUNNEL) {
1600 		ip_encap(skb, vif->local, vif->remote);
1601 		/* FIXME: extra output firewall step used to be here. --RR */
1602 		vif->dev->stats.tx_packets++;
1603 		vif->dev->stats.tx_bytes += skb->len;
1604 	}
1605 
1606 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1607 
1608 	/*
1609 	 * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1610 	 * not only before forwarding, but after forwarding on all output
1611 	 * interfaces. It is clear, if mrouter runs a multicasting
1612 	 * program, it should receive packets not depending to what interface
1613 	 * program is joined.
1614 	 * If we will not make it, the program will have to join on all
1615 	 * interfaces. On the other hand, multihoming host (or router, but
1616 	 * not mrouter) cannot join to more than one interface - it will
1617 	 * result in receiving multiple packets.
1618 	 */
1619 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, skb, skb->dev, dev,
1620 		ipmr_forward_finish);
1621 	return;
1622 
1623 out_free:
1624 	kfree_skb(skb);
1625 }
1626 
1627 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1628 {
1629 	int ct;
1630 
1631 	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1632 		if (mrt->vif_table[ct].dev == dev)
1633 			break;
1634 	}
1635 	return ct;
1636 }
1637 
1638 /* "local" means that we should preserve one skb (for local delivery) */
1639 
1640 static int ip_mr_forward(struct net *net, struct mr_table *mrt,
1641 			 struct sk_buff *skb, struct mfc_cache *cache,
1642 			 int local)
1643 {
1644 	int psend = -1;
1645 	int vif, ct;
1646 
1647 	vif = cache->mfc_parent;
1648 	cache->mfc_un.res.pkt++;
1649 	cache->mfc_un.res.bytes += skb->len;
1650 
1651 	/*
1652 	 * Wrong interface: drop packet and (maybe) send PIM assert.
1653 	 */
1654 	if (mrt->vif_table[vif].dev != skb->dev) {
1655 		int true_vifi;
1656 
1657 		if (skb_rtable(skb)->fl.iif == 0) {
1658 			/* It is our own packet, looped back.
1659 			 * Very complicated situation...
1660 			 *
1661 			 * The best workaround until routing daemons will be
1662 			 * fixed is not to redistribute packet, if it was
1663 			 * send through wrong interface. It means, that
1664 			 * multicast applications WILL NOT work for
1665 			 * (S,G), which have default multicast route pointing
1666 			 * to wrong oif. In any case, it is not a good
1667 			 * idea to use multicasting applications on router.
1668 			 */
1669 			goto dont_forward;
1670 		}
1671 
1672 		cache->mfc_un.res.wrong_if++;
1673 		true_vifi = ipmr_find_vif(mrt, skb->dev);
1674 
1675 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
1676 		    /* pimsm uses asserts, when switching from RPT to SPT,
1677 		     * so that we cannot check that packet arrived on an oif.
1678 		     * It is bad, but otherwise we would need to move pretty
1679 		     * large chunk of pimd to kernel. Ough... --ANK
1680 		     */
1681 		    (mrt->mroute_do_pim ||
1682 		     cache->mfc_un.res.ttls[true_vifi] < 255) &&
1683 		    time_after(jiffies,
1684 			       cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1685 			cache->mfc_un.res.last_assert = jiffies;
1686 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1687 		}
1688 		goto dont_forward;
1689 	}
1690 
1691 	mrt->vif_table[vif].pkt_in++;
1692 	mrt->vif_table[vif].bytes_in += skb->len;
1693 
1694 	/*
1695 	 *	Forward the frame
1696 	 */
1697 	for (ct = cache->mfc_un.res.maxvif - 1;
1698 	     ct >= cache->mfc_un.res.minvif; ct--) {
1699 		if (ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1700 			if (psend != -1) {
1701 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1702 
1703 				if (skb2)
1704 					ipmr_queue_xmit(net, mrt, skb2, cache,
1705 							psend);
1706 			}
1707 			psend = ct;
1708 		}
1709 	}
1710 	if (psend != -1) {
1711 		if (local) {
1712 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1713 
1714 			if (skb2)
1715 				ipmr_queue_xmit(net, mrt, skb2, cache, psend);
1716 		} else {
1717 			ipmr_queue_xmit(net, mrt, skb, cache, psend);
1718 			return 0;
1719 		}
1720 	}
1721 
1722 dont_forward:
1723 	if (!local)
1724 		kfree_skb(skb);
1725 	return 0;
1726 }
1727 
1728 
1729 /*
1730  *	Multicast packets for forwarding arrive here
1731  *	Called with rcu_read_lock();
1732  */
1733 
1734 int ip_mr_input(struct sk_buff *skb)
1735 {
1736 	struct mfc_cache *cache;
1737 	struct net *net = dev_net(skb->dev);
1738 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
1739 	struct mr_table *mrt;
1740 	int err;
1741 
1742 	/* Packet is looped back after forward, it should not be
1743 	 * forwarded second time, but still can be delivered locally.
1744 	 */
1745 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
1746 		goto dont_forward;
1747 
1748 	err = ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt);
1749 	if (err < 0) {
1750 		kfree_skb(skb);
1751 		return err;
1752 	}
1753 
1754 	if (!local) {
1755 		if (IPCB(skb)->opt.router_alert) {
1756 			if (ip_call_ra_chain(skb))
1757 				return 0;
1758 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
1759 			/* IGMPv1 (and broken IGMPv2 implementations sort of
1760 			 * Cisco IOS <= 11.2(8)) do not put router alert
1761 			 * option to IGMP packets destined to routable
1762 			 * groups. It is very bad, because it means
1763 			 * that we can forward NO IGMP messages.
1764 			 */
1765 			struct sock *mroute_sk;
1766 
1767 			mroute_sk = rcu_dereference(mrt->mroute_sk);
1768 			if (mroute_sk) {
1769 				nf_reset(skb);
1770 				raw_rcv(mroute_sk, skb);
1771 				return 0;
1772 			}
1773 		    }
1774 	}
1775 
1776 	/* already under rcu_read_lock() */
1777 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
1778 
1779 	/*
1780 	 *	No usable cache entry
1781 	 */
1782 	if (cache == NULL) {
1783 		int vif;
1784 
1785 		if (local) {
1786 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1787 			ip_local_deliver(skb);
1788 			if (skb2 == NULL)
1789 				return -ENOBUFS;
1790 			skb = skb2;
1791 		}
1792 
1793 		read_lock(&mrt_lock);
1794 		vif = ipmr_find_vif(mrt, skb->dev);
1795 		if (vif >= 0) {
1796 			int err2 = ipmr_cache_unresolved(mrt, vif, skb);
1797 			read_unlock(&mrt_lock);
1798 
1799 			return err2;
1800 		}
1801 		read_unlock(&mrt_lock);
1802 		kfree_skb(skb);
1803 		return -ENODEV;
1804 	}
1805 
1806 	read_lock(&mrt_lock);
1807 	ip_mr_forward(net, mrt, skb, cache, local);
1808 	read_unlock(&mrt_lock);
1809 
1810 	if (local)
1811 		return ip_local_deliver(skb);
1812 
1813 	return 0;
1814 
1815 dont_forward:
1816 	if (local)
1817 		return ip_local_deliver(skb);
1818 	kfree_skb(skb);
1819 	return 0;
1820 }
1821 
1822 #ifdef CONFIG_IP_PIMSM
1823 /* called with rcu_read_lock() */
1824 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
1825 		     unsigned int pimlen)
1826 {
1827 	struct net_device *reg_dev = NULL;
1828 	struct iphdr *encap;
1829 
1830 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
1831 	/*
1832 	 * Check that:
1833 	 * a. packet is really sent to a multicast group
1834 	 * b. packet is not a NULL-REGISTER
1835 	 * c. packet is not truncated
1836 	 */
1837 	if (!ipv4_is_multicast(encap->daddr) ||
1838 	    encap->tot_len == 0 ||
1839 	    ntohs(encap->tot_len) + pimlen > skb->len)
1840 		return 1;
1841 
1842 	read_lock(&mrt_lock);
1843 	if (mrt->mroute_reg_vif_num >= 0)
1844 		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
1845 	read_unlock(&mrt_lock);
1846 
1847 	if (reg_dev == NULL)
1848 		return 1;
1849 
1850 	skb->mac_header = skb->network_header;
1851 	skb_pull(skb, (u8 *)encap - skb->data);
1852 	skb_reset_network_header(skb);
1853 	skb->protocol = htons(ETH_P_IP);
1854 	skb->ip_summed = CHECKSUM_NONE;
1855 	skb->pkt_type = PACKET_HOST;
1856 
1857 	skb_tunnel_rx(skb, reg_dev);
1858 
1859 	netif_rx(skb);
1860 
1861 	return NET_RX_SUCCESS;
1862 }
1863 #endif
1864 
1865 #ifdef CONFIG_IP_PIMSM_V1
1866 /*
1867  * Handle IGMP messages of PIMv1
1868  */
1869 
1870 int pim_rcv_v1(struct sk_buff *skb)
1871 {
1872 	struct igmphdr *pim;
1873 	struct net *net = dev_net(skb->dev);
1874 	struct mr_table *mrt;
1875 
1876 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
1877 		goto drop;
1878 
1879 	pim = igmp_hdr(skb);
1880 
1881 	if (ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt) < 0)
1882 		goto drop;
1883 
1884 	if (!mrt->mroute_do_pim ||
1885 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
1886 		goto drop;
1887 
1888 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
1889 drop:
1890 		kfree_skb(skb);
1891 	}
1892 	return 0;
1893 }
1894 #endif
1895 
1896 #ifdef CONFIG_IP_PIMSM_V2
1897 static int pim_rcv(struct sk_buff *skb)
1898 {
1899 	struct pimreghdr *pim;
1900 	struct net *net = dev_net(skb->dev);
1901 	struct mr_table *mrt;
1902 
1903 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
1904 		goto drop;
1905 
1906 	pim = (struct pimreghdr *)skb_transport_header(skb);
1907 	if (pim->type != ((PIM_VERSION << 4) | (PIM_REGISTER)) ||
1908 	    (pim->flags & PIM_NULL_REGISTER) ||
1909 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
1910 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
1911 		goto drop;
1912 
1913 	if (ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt) < 0)
1914 		goto drop;
1915 
1916 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
1917 drop:
1918 		kfree_skb(skb);
1919 	}
1920 	return 0;
1921 }
1922 #endif
1923 
1924 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
1925 			      struct mfc_cache *c, struct rtmsg *rtm)
1926 {
1927 	int ct;
1928 	struct rtnexthop *nhp;
1929 	u8 *b = skb_tail_pointer(skb);
1930 	struct rtattr *mp_head;
1931 
1932 	/* If cache is unresolved, don't try to parse IIF and OIF */
1933 	if (c->mfc_parent >= MAXVIFS)
1934 		return -ENOENT;
1935 
1936 	if (VIF_EXISTS(mrt, c->mfc_parent))
1937 		RTA_PUT(skb, RTA_IIF, 4, &mrt->vif_table[c->mfc_parent].dev->ifindex);
1938 
1939 	mp_head = (struct rtattr *)skb_put(skb, RTA_LENGTH(0));
1940 
1941 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
1942 		if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
1943 			if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
1944 				goto rtattr_failure;
1945 			nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
1946 			nhp->rtnh_flags = 0;
1947 			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
1948 			nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
1949 			nhp->rtnh_len = sizeof(*nhp);
1950 		}
1951 	}
1952 	mp_head->rta_type = RTA_MULTIPATH;
1953 	mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head;
1954 	rtm->rtm_type = RTN_MULTICAST;
1955 	return 1;
1956 
1957 rtattr_failure:
1958 	nlmsg_trim(skb, b);
1959 	return -EMSGSIZE;
1960 }
1961 
1962 int ipmr_get_route(struct net *net,
1963 		   struct sk_buff *skb, struct rtmsg *rtm, int nowait)
1964 {
1965 	int err;
1966 	struct mr_table *mrt;
1967 	struct mfc_cache *cache;
1968 	struct rtable *rt = skb_rtable(skb);
1969 
1970 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
1971 	if (mrt == NULL)
1972 		return -ENOENT;
1973 
1974 	rcu_read_lock();
1975 	cache = ipmr_cache_find(mrt, rt->rt_src, rt->rt_dst);
1976 
1977 	if (cache == NULL) {
1978 		struct sk_buff *skb2;
1979 		struct iphdr *iph;
1980 		struct net_device *dev;
1981 		int vif = -1;
1982 
1983 		if (nowait) {
1984 			rcu_read_unlock();
1985 			return -EAGAIN;
1986 		}
1987 
1988 		dev = skb->dev;
1989 		read_lock(&mrt_lock);
1990 		if (dev)
1991 			vif = ipmr_find_vif(mrt, dev);
1992 		if (vif < 0) {
1993 			read_unlock(&mrt_lock);
1994 			rcu_read_unlock();
1995 			return -ENODEV;
1996 		}
1997 		skb2 = skb_clone(skb, GFP_ATOMIC);
1998 		if (!skb2) {
1999 			read_unlock(&mrt_lock);
2000 			rcu_read_unlock();
2001 			return -ENOMEM;
2002 		}
2003 
2004 		skb_push(skb2, sizeof(struct iphdr));
2005 		skb_reset_network_header(skb2);
2006 		iph = ip_hdr(skb2);
2007 		iph->ihl = sizeof(struct iphdr) >> 2;
2008 		iph->saddr = rt->rt_src;
2009 		iph->daddr = rt->rt_dst;
2010 		iph->version = 0;
2011 		err = ipmr_cache_unresolved(mrt, vif, skb2);
2012 		read_unlock(&mrt_lock);
2013 		rcu_read_unlock();
2014 		return err;
2015 	}
2016 
2017 	read_lock(&mrt_lock);
2018 	if (!nowait && (rtm->rtm_flags & RTM_F_NOTIFY))
2019 		cache->mfc_flags |= MFC_NOTIFY;
2020 	err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2021 	read_unlock(&mrt_lock);
2022 	rcu_read_unlock();
2023 	return err;
2024 }
2025 
2026 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2027 			    u32 pid, u32 seq, struct mfc_cache *c)
2028 {
2029 	struct nlmsghdr *nlh;
2030 	struct rtmsg *rtm;
2031 
2032 	nlh = nlmsg_put(skb, pid, seq, RTM_NEWROUTE, sizeof(*rtm), NLM_F_MULTI);
2033 	if (nlh == NULL)
2034 		return -EMSGSIZE;
2035 
2036 	rtm = nlmsg_data(nlh);
2037 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2038 	rtm->rtm_dst_len  = 32;
2039 	rtm->rtm_src_len  = 32;
2040 	rtm->rtm_tos      = 0;
2041 	rtm->rtm_table    = mrt->id;
2042 	NLA_PUT_U32(skb, RTA_TABLE, mrt->id);
2043 	rtm->rtm_type     = RTN_MULTICAST;
2044 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2045 	rtm->rtm_protocol = RTPROT_UNSPEC;
2046 	rtm->rtm_flags    = 0;
2047 
2048 	NLA_PUT_BE32(skb, RTA_SRC, c->mfc_origin);
2049 	NLA_PUT_BE32(skb, RTA_DST, c->mfc_mcastgrp);
2050 
2051 	if (__ipmr_fill_mroute(mrt, skb, c, rtm) < 0)
2052 		goto nla_put_failure;
2053 
2054 	return nlmsg_end(skb, nlh);
2055 
2056 nla_put_failure:
2057 	nlmsg_cancel(skb, nlh);
2058 	return -EMSGSIZE;
2059 }
2060 
2061 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2062 {
2063 	struct net *net = sock_net(skb->sk);
2064 	struct mr_table *mrt;
2065 	struct mfc_cache *mfc;
2066 	unsigned int t = 0, s_t;
2067 	unsigned int h = 0, s_h;
2068 	unsigned int e = 0, s_e;
2069 
2070 	s_t = cb->args[0];
2071 	s_h = cb->args[1];
2072 	s_e = cb->args[2];
2073 
2074 	rcu_read_lock();
2075 	ipmr_for_each_table(mrt, net) {
2076 		if (t < s_t)
2077 			goto next_table;
2078 		if (t > s_t)
2079 			s_h = 0;
2080 		for (h = s_h; h < MFC_LINES; h++) {
2081 			list_for_each_entry_rcu(mfc, &mrt->mfc_cache_array[h], list) {
2082 				if (e < s_e)
2083 					goto next_entry;
2084 				if (ipmr_fill_mroute(mrt, skb,
2085 						     NETLINK_CB(cb->skb).pid,
2086 						     cb->nlh->nlmsg_seq,
2087 						     mfc) < 0)
2088 					goto done;
2089 next_entry:
2090 				e++;
2091 			}
2092 			e = s_e = 0;
2093 		}
2094 		s_h = 0;
2095 next_table:
2096 		t++;
2097 	}
2098 done:
2099 	rcu_read_unlock();
2100 
2101 	cb->args[2] = e;
2102 	cb->args[1] = h;
2103 	cb->args[0] = t;
2104 
2105 	return skb->len;
2106 }
2107 
2108 #ifdef CONFIG_PROC_FS
2109 /*
2110  *	The /proc interfaces to multicast routing :
2111  *	/proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2112  */
2113 struct ipmr_vif_iter {
2114 	struct seq_net_private p;
2115 	struct mr_table *mrt;
2116 	int ct;
2117 };
2118 
2119 static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2120 					   struct ipmr_vif_iter *iter,
2121 					   loff_t pos)
2122 {
2123 	struct mr_table *mrt = iter->mrt;
2124 
2125 	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2126 		if (!VIF_EXISTS(mrt, iter->ct))
2127 			continue;
2128 		if (pos-- == 0)
2129 			return &mrt->vif_table[iter->ct];
2130 	}
2131 	return NULL;
2132 }
2133 
2134 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2135 	__acquires(mrt_lock)
2136 {
2137 	struct ipmr_vif_iter *iter = seq->private;
2138 	struct net *net = seq_file_net(seq);
2139 	struct mr_table *mrt;
2140 
2141 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2142 	if (mrt == NULL)
2143 		return ERR_PTR(-ENOENT);
2144 
2145 	iter->mrt = mrt;
2146 
2147 	read_lock(&mrt_lock);
2148 	return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2149 		: SEQ_START_TOKEN;
2150 }
2151 
2152 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2153 {
2154 	struct ipmr_vif_iter *iter = seq->private;
2155 	struct net *net = seq_file_net(seq);
2156 	struct mr_table *mrt = iter->mrt;
2157 
2158 	++*pos;
2159 	if (v == SEQ_START_TOKEN)
2160 		return ipmr_vif_seq_idx(net, iter, 0);
2161 
2162 	while (++iter->ct < mrt->maxvif) {
2163 		if (!VIF_EXISTS(mrt, iter->ct))
2164 			continue;
2165 		return &mrt->vif_table[iter->ct];
2166 	}
2167 	return NULL;
2168 }
2169 
2170 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2171 	__releases(mrt_lock)
2172 {
2173 	read_unlock(&mrt_lock);
2174 }
2175 
2176 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2177 {
2178 	struct ipmr_vif_iter *iter = seq->private;
2179 	struct mr_table *mrt = iter->mrt;
2180 
2181 	if (v == SEQ_START_TOKEN) {
2182 		seq_puts(seq,
2183 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2184 	} else {
2185 		const struct vif_device *vif = v;
2186 		const char *name =  vif->dev ? vif->dev->name : "none";
2187 
2188 		seq_printf(seq,
2189 			   "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2190 			   vif - mrt->vif_table,
2191 			   name, vif->bytes_in, vif->pkt_in,
2192 			   vif->bytes_out, vif->pkt_out,
2193 			   vif->flags, vif->local, vif->remote);
2194 	}
2195 	return 0;
2196 }
2197 
2198 static const struct seq_operations ipmr_vif_seq_ops = {
2199 	.start = ipmr_vif_seq_start,
2200 	.next  = ipmr_vif_seq_next,
2201 	.stop  = ipmr_vif_seq_stop,
2202 	.show  = ipmr_vif_seq_show,
2203 };
2204 
2205 static int ipmr_vif_open(struct inode *inode, struct file *file)
2206 {
2207 	return seq_open_net(inode, file, &ipmr_vif_seq_ops,
2208 			    sizeof(struct ipmr_vif_iter));
2209 }
2210 
2211 static const struct file_operations ipmr_vif_fops = {
2212 	.owner	 = THIS_MODULE,
2213 	.open    = ipmr_vif_open,
2214 	.read    = seq_read,
2215 	.llseek  = seq_lseek,
2216 	.release = seq_release_net,
2217 };
2218 
2219 struct ipmr_mfc_iter {
2220 	struct seq_net_private p;
2221 	struct mr_table *mrt;
2222 	struct list_head *cache;
2223 	int ct;
2224 };
2225 
2226 
2227 static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
2228 					  struct ipmr_mfc_iter *it, loff_t pos)
2229 {
2230 	struct mr_table *mrt = it->mrt;
2231 	struct mfc_cache *mfc;
2232 
2233 	rcu_read_lock();
2234 	for (it->ct = 0; it->ct < MFC_LINES; it->ct++) {
2235 		it->cache = &mrt->mfc_cache_array[it->ct];
2236 		list_for_each_entry_rcu(mfc, it->cache, list)
2237 			if (pos-- == 0)
2238 				return mfc;
2239 	}
2240 	rcu_read_unlock();
2241 
2242 	spin_lock_bh(&mfc_unres_lock);
2243 	it->cache = &mrt->mfc_unres_queue;
2244 	list_for_each_entry(mfc, it->cache, list)
2245 		if (pos-- == 0)
2246 			return mfc;
2247 	spin_unlock_bh(&mfc_unres_lock);
2248 
2249 	it->cache = NULL;
2250 	return NULL;
2251 }
2252 
2253 
2254 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2255 {
2256 	struct ipmr_mfc_iter *it = seq->private;
2257 	struct net *net = seq_file_net(seq);
2258 	struct mr_table *mrt;
2259 
2260 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2261 	if (mrt == NULL)
2262 		return ERR_PTR(-ENOENT);
2263 
2264 	it->mrt = mrt;
2265 	it->cache = NULL;
2266 	it->ct = 0;
2267 	return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
2268 		: SEQ_START_TOKEN;
2269 }
2270 
2271 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2272 {
2273 	struct mfc_cache *mfc = v;
2274 	struct ipmr_mfc_iter *it = seq->private;
2275 	struct net *net = seq_file_net(seq);
2276 	struct mr_table *mrt = it->mrt;
2277 
2278 	++*pos;
2279 
2280 	if (v == SEQ_START_TOKEN)
2281 		return ipmr_mfc_seq_idx(net, seq->private, 0);
2282 
2283 	if (mfc->list.next != it->cache)
2284 		return list_entry(mfc->list.next, struct mfc_cache, list);
2285 
2286 	if (it->cache == &mrt->mfc_unres_queue)
2287 		goto end_of_list;
2288 
2289 	BUG_ON(it->cache != &mrt->mfc_cache_array[it->ct]);
2290 
2291 	while (++it->ct < MFC_LINES) {
2292 		it->cache = &mrt->mfc_cache_array[it->ct];
2293 		if (list_empty(it->cache))
2294 			continue;
2295 		return list_first_entry(it->cache, struct mfc_cache, list);
2296 	}
2297 
2298 	/* exhausted cache_array, show unresolved */
2299 	rcu_read_unlock();
2300 	it->cache = &mrt->mfc_unres_queue;
2301 	it->ct = 0;
2302 
2303 	spin_lock_bh(&mfc_unres_lock);
2304 	if (!list_empty(it->cache))
2305 		return list_first_entry(it->cache, struct mfc_cache, list);
2306 
2307 end_of_list:
2308 	spin_unlock_bh(&mfc_unres_lock);
2309 	it->cache = NULL;
2310 
2311 	return NULL;
2312 }
2313 
2314 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
2315 {
2316 	struct ipmr_mfc_iter *it = seq->private;
2317 	struct mr_table *mrt = it->mrt;
2318 
2319 	if (it->cache == &mrt->mfc_unres_queue)
2320 		spin_unlock_bh(&mfc_unres_lock);
2321 	else if (it->cache == &mrt->mfc_cache_array[it->ct])
2322 		rcu_read_unlock();
2323 }
2324 
2325 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2326 {
2327 	int n;
2328 
2329 	if (v == SEQ_START_TOKEN) {
2330 		seq_puts(seq,
2331 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2332 	} else {
2333 		const struct mfc_cache *mfc = v;
2334 		const struct ipmr_mfc_iter *it = seq->private;
2335 		const struct mr_table *mrt = it->mrt;
2336 
2337 		seq_printf(seq, "%08X %08X %-3hd",
2338 			   (__force u32) mfc->mfc_mcastgrp,
2339 			   (__force u32) mfc->mfc_origin,
2340 			   mfc->mfc_parent);
2341 
2342 		if (it->cache != &mrt->mfc_unres_queue) {
2343 			seq_printf(seq, " %8lu %8lu %8lu",
2344 				   mfc->mfc_un.res.pkt,
2345 				   mfc->mfc_un.res.bytes,
2346 				   mfc->mfc_un.res.wrong_if);
2347 			for (n = mfc->mfc_un.res.minvif;
2348 			     n < mfc->mfc_un.res.maxvif; n++) {
2349 				if (VIF_EXISTS(mrt, n) &&
2350 				    mfc->mfc_un.res.ttls[n] < 255)
2351 					seq_printf(seq,
2352 					   " %2d:%-3d",
2353 					   n, mfc->mfc_un.res.ttls[n]);
2354 			}
2355 		} else {
2356 			/* unresolved mfc_caches don't contain
2357 			 * pkt, bytes and wrong_if values
2358 			 */
2359 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
2360 		}
2361 		seq_putc(seq, '\n');
2362 	}
2363 	return 0;
2364 }
2365 
2366 static const struct seq_operations ipmr_mfc_seq_ops = {
2367 	.start = ipmr_mfc_seq_start,
2368 	.next  = ipmr_mfc_seq_next,
2369 	.stop  = ipmr_mfc_seq_stop,
2370 	.show  = ipmr_mfc_seq_show,
2371 };
2372 
2373 static int ipmr_mfc_open(struct inode *inode, struct file *file)
2374 {
2375 	return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
2376 			    sizeof(struct ipmr_mfc_iter));
2377 }
2378 
2379 static const struct file_operations ipmr_mfc_fops = {
2380 	.owner	 = THIS_MODULE,
2381 	.open    = ipmr_mfc_open,
2382 	.read    = seq_read,
2383 	.llseek  = seq_lseek,
2384 	.release = seq_release_net,
2385 };
2386 #endif
2387 
2388 #ifdef CONFIG_IP_PIMSM_V2
2389 static const struct net_protocol pim_protocol = {
2390 	.handler	=	pim_rcv,
2391 	.netns_ok	=	1,
2392 };
2393 #endif
2394 
2395 
2396 /*
2397  *	Setup for IP multicast routing
2398  */
2399 static int __net_init ipmr_net_init(struct net *net)
2400 {
2401 	int err;
2402 
2403 	err = ipmr_rules_init(net);
2404 	if (err < 0)
2405 		goto fail;
2406 
2407 #ifdef CONFIG_PROC_FS
2408 	err = -ENOMEM;
2409 	if (!proc_net_fops_create(net, "ip_mr_vif", 0, &ipmr_vif_fops))
2410 		goto proc_vif_fail;
2411 	if (!proc_net_fops_create(net, "ip_mr_cache", 0, &ipmr_mfc_fops))
2412 		goto proc_cache_fail;
2413 #endif
2414 	return 0;
2415 
2416 #ifdef CONFIG_PROC_FS
2417 proc_cache_fail:
2418 	proc_net_remove(net, "ip_mr_vif");
2419 proc_vif_fail:
2420 	ipmr_rules_exit(net);
2421 #endif
2422 fail:
2423 	return err;
2424 }
2425 
2426 static void __net_exit ipmr_net_exit(struct net *net)
2427 {
2428 #ifdef CONFIG_PROC_FS
2429 	proc_net_remove(net, "ip_mr_cache");
2430 	proc_net_remove(net, "ip_mr_vif");
2431 #endif
2432 	ipmr_rules_exit(net);
2433 }
2434 
2435 static struct pernet_operations ipmr_net_ops = {
2436 	.init = ipmr_net_init,
2437 	.exit = ipmr_net_exit,
2438 };
2439 
2440 int __init ip_mr_init(void)
2441 {
2442 	int err;
2443 
2444 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
2445 				       sizeof(struct mfc_cache),
2446 				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
2447 				       NULL);
2448 	if (!mrt_cachep)
2449 		return -ENOMEM;
2450 
2451 	err = register_pernet_subsys(&ipmr_net_ops);
2452 	if (err)
2453 		goto reg_pernet_fail;
2454 
2455 	err = register_netdevice_notifier(&ip_mr_notifier);
2456 	if (err)
2457 		goto reg_notif_fail;
2458 #ifdef CONFIG_IP_PIMSM_V2
2459 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
2460 		printk(KERN_ERR "ip_mr_init: can't add PIM protocol\n");
2461 		err = -EAGAIN;
2462 		goto add_proto_fail;
2463 	}
2464 #endif
2465 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE, NULL, ipmr_rtm_dumproute);
2466 	return 0;
2467 
2468 #ifdef CONFIG_IP_PIMSM_V2
2469 add_proto_fail:
2470 	unregister_netdevice_notifier(&ip_mr_notifier);
2471 #endif
2472 reg_notif_fail:
2473 	unregister_pernet_subsys(&ipmr_net_ops);
2474 reg_pernet_fail:
2475 	kmem_cache_destroy(mrt_cachep);
2476 	return err;
2477 }
2478