xref: /linux/net/ipv4/ipmr.c (revision e3e29f990cc77c5b23280c77275812a3f010cc41)
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/uaccess.h>
30 #include <linux/types.h>
31 #include <linux/capability.h>
32 #include <linux/errno.h>
33 #include <linux/timer.h>
34 #include <linux/mm.h>
35 #include <linux/kernel.h>
36 #include <linux/fcntl.h>
37 #include <linux/stat.h>
38 #include <linux/socket.h>
39 #include <linux/in.h>
40 #include <linux/inet.h>
41 #include <linux/netdevice.h>
42 #include <linux/inetdevice.h>
43 #include <linux/igmp.h>
44 #include <linux/proc_fs.h>
45 #include <linux/seq_file.h>
46 #include <linux/mroute.h>
47 #include <linux/init.h>
48 #include <linux/if_ether.h>
49 #include <linux/slab.h>
50 #include <net/net_namespace.h>
51 #include <net/ip.h>
52 #include <net/protocol.h>
53 #include <linux/skbuff.h>
54 #include <net/route.h>
55 #include <net/sock.h>
56 #include <net/icmp.h>
57 #include <net/udp.h>
58 #include <net/raw.h>
59 #include <linux/notifier.h>
60 #include <linux/if_arp.h>
61 #include <linux/netfilter_ipv4.h>
62 #include <linux/compat.h>
63 #include <linux/export.h>
64 #include <net/ip_tunnels.h>
65 #include <net/checksum.h>
66 #include <net/netlink.h>
67 #include <net/fib_rules.h>
68 #include <linux/netconf.h>
69 
70 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
71 #define CONFIG_IP_PIMSM	1
72 #endif
73 
74 struct mr_table {
75 	struct list_head	list;
76 #ifdef CONFIG_NET_NS
77 	struct net		*net;
78 #endif
79 	u32			id;
80 	struct sock __rcu	*mroute_sk;
81 	struct timer_list	ipmr_expire_timer;
82 	struct list_head	mfc_unres_queue;
83 	struct list_head	mfc_cache_array[MFC_LINES];
84 	struct vif_device	vif_table[MAXVIFS];
85 	int			maxvif;
86 	atomic_t		cache_resolve_queue_len;
87 	bool			mroute_do_assert;
88 	bool			mroute_do_pim;
89 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
90 	int			mroute_reg_vif_num;
91 #endif
92 };
93 
94 struct ipmr_rule {
95 	struct fib_rule		common;
96 };
97 
98 struct ipmr_result {
99 	struct mr_table		*mrt;
100 };
101 
102 /* Big lock, protecting vif table, mrt cache and mroute socket state.
103  * Note that the changes are semaphored via rtnl_lock.
104  */
105 
106 static DEFINE_RWLOCK(mrt_lock);
107 
108 /*
109  *	Multicast router control variables
110  */
111 
112 #define VIF_EXISTS(_mrt, _idx) ((_mrt)->vif_table[_idx].dev != NULL)
113 
114 /* Special spinlock for queue of unresolved entries */
115 static DEFINE_SPINLOCK(mfc_unres_lock);
116 
117 /* We return to original Alan's scheme. Hash table of resolved
118  * entries is changed only in process context and protected
119  * with weak lock mrt_lock. Queue of unresolved entries is protected
120  * with strong spinlock mfc_unres_lock.
121  *
122  * In this case data path is free of exclusive locks at all.
123  */
124 
125 static struct kmem_cache *mrt_cachep __read_mostly;
126 
127 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
128 static void ipmr_free_table(struct mr_table *mrt);
129 
130 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
131 			  struct sk_buff *skb, struct mfc_cache *cache,
132 			  int local);
133 static int ipmr_cache_report(struct mr_table *mrt,
134 			     struct sk_buff *pkt, vifi_t vifi, int assert);
135 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
136 			      struct mfc_cache *c, struct rtmsg *rtm);
137 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
138 				 int cmd);
139 static void mroute_clean_tables(struct mr_table *mrt);
140 static void ipmr_expire_process(unsigned long arg);
141 
142 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
143 #define ipmr_for_each_table(mrt, net) \
144 	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
145 
146 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
147 {
148 	struct mr_table *mrt;
149 
150 	ipmr_for_each_table(mrt, net) {
151 		if (mrt->id == id)
152 			return mrt;
153 	}
154 	return NULL;
155 }
156 
157 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
158 			   struct mr_table **mrt)
159 {
160 	int err;
161 	struct ipmr_result res;
162 	struct fib_lookup_arg arg = {
163 		.result = &res,
164 		.flags = FIB_LOOKUP_NOREF,
165 	};
166 
167 	err = fib_rules_lookup(net->ipv4.mr_rules_ops,
168 			       flowi4_to_flowi(flp4), 0, &arg);
169 	if (err < 0)
170 		return err;
171 	*mrt = res.mrt;
172 	return 0;
173 }
174 
175 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
176 			    int flags, struct fib_lookup_arg *arg)
177 {
178 	struct ipmr_result *res = arg->result;
179 	struct mr_table *mrt;
180 
181 	switch (rule->action) {
182 	case FR_ACT_TO_TBL:
183 		break;
184 	case FR_ACT_UNREACHABLE:
185 		return -ENETUNREACH;
186 	case FR_ACT_PROHIBIT:
187 		return -EACCES;
188 	case FR_ACT_BLACKHOLE:
189 	default:
190 		return -EINVAL;
191 	}
192 
193 	mrt = ipmr_get_table(rule->fr_net, rule->table);
194 	if (mrt == NULL)
195 		return -EAGAIN;
196 	res->mrt = mrt;
197 	return 0;
198 }
199 
200 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
201 {
202 	return 1;
203 }
204 
205 static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
206 	FRA_GENERIC_POLICY,
207 };
208 
209 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
210 			       struct fib_rule_hdr *frh, struct nlattr **tb)
211 {
212 	return 0;
213 }
214 
215 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
216 			     struct nlattr **tb)
217 {
218 	return 1;
219 }
220 
221 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
222 			  struct fib_rule_hdr *frh)
223 {
224 	frh->dst_len = 0;
225 	frh->src_len = 0;
226 	frh->tos     = 0;
227 	return 0;
228 }
229 
230 static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
231 	.family		= RTNL_FAMILY_IPMR,
232 	.rule_size	= sizeof(struct ipmr_rule),
233 	.addr_size	= sizeof(u32),
234 	.action		= ipmr_rule_action,
235 	.match		= ipmr_rule_match,
236 	.configure	= ipmr_rule_configure,
237 	.compare	= ipmr_rule_compare,
238 	.default_pref	= fib_default_rule_pref,
239 	.fill		= ipmr_rule_fill,
240 	.nlgroup	= RTNLGRP_IPV4_RULE,
241 	.policy		= ipmr_rule_policy,
242 	.owner		= THIS_MODULE,
243 };
244 
245 static int __net_init ipmr_rules_init(struct net *net)
246 {
247 	struct fib_rules_ops *ops;
248 	struct mr_table *mrt;
249 	int err;
250 
251 	ops = fib_rules_register(&ipmr_rules_ops_template, net);
252 	if (IS_ERR(ops))
253 		return PTR_ERR(ops);
254 
255 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
256 
257 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
258 	if (mrt == NULL) {
259 		err = -ENOMEM;
260 		goto err1;
261 	}
262 
263 	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
264 	if (err < 0)
265 		goto err2;
266 
267 	net->ipv4.mr_rules_ops = ops;
268 	return 0;
269 
270 err2:
271 	ipmr_free_table(mrt);
272 err1:
273 	fib_rules_unregister(ops);
274 	return err;
275 }
276 
277 static void __net_exit ipmr_rules_exit(struct net *net)
278 {
279 	struct mr_table *mrt, *next;
280 
281 	rtnl_lock();
282 	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
283 		list_del(&mrt->list);
284 		ipmr_free_table(mrt);
285 	}
286 	fib_rules_unregister(net->ipv4.mr_rules_ops);
287 	rtnl_unlock();
288 }
289 #else
290 #define ipmr_for_each_table(mrt, net) \
291 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
292 
293 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
294 {
295 	return net->ipv4.mrt;
296 }
297 
298 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
299 			   struct mr_table **mrt)
300 {
301 	*mrt = net->ipv4.mrt;
302 	return 0;
303 }
304 
305 static int __net_init ipmr_rules_init(struct net *net)
306 {
307 	net->ipv4.mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
308 	return net->ipv4.mrt ? 0 : -ENOMEM;
309 }
310 
311 static void __net_exit ipmr_rules_exit(struct net *net)
312 {
313 	rtnl_lock();
314 	ipmr_free_table(net->ipv4.mrt);
315 	net->ipv4.mrt = NULL;
316 	rtnl_unlock();
317 }
318 #endif
319 
320 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
321 {
322 	struct mr_table *mrt;
323 	unsigned int i;
324 
325 	mrt = ipmr_get_table(net, id);
326 	if (mrt != NULL)
327 		return mrt;
328 
329 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
330 	if (mrt == NULL)
331 		return NULL;
332 	write_pnet(&mrt->net, net);
333 	mrt->id = id;
334 
335 	/* Forwarding cache */
336 	for (i = 0; i < MFC_LINES; i++)
337 		INIT_LIST_HEAD(&mrt->mfc_cache_array[i]);
338 
339 	INIT_LIST_HEAD(&mrt->mfc_unres_queue);
340 
341 	setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
342 		    (unsigned long)mrt);
343 
344 #ifdef CONFIG_IP_PIMSM
345 	mrt->mroute_reg_vif_num = -1;
346 #endif
347 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
348 	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
349 #endif
350 	return mrt;
351 }
352 
353 static void ipmr_free_table(struct mr_table *mrt)
354 {
355 	del_timer_sync(&mrt->ipmr_expire_timer);
356 	mroute_clean_tables(mrt);
357 	kfree(mrt);
358 }
359 
360 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
361 
362 static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
363 {
364 	struct net *net = dev_net(dev);
365 
366 	dev_close(dev);
367 
368 	dev = __dev_get_by_name(net, "tunl0");
369 	if (dev) {
370 		const struct net_device_ops *ops = dev->netdev_ops;
371 		struct ifreq ifr;
372 		struct ip_tunnel_parm p;
373 
374 		memset(&p, 0, sizeof(p));
375 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
376 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
377 		p.iph.version = 4;
378 		p.iph.ihl = 5;
379 		p.iph.protocol = IPPROTO_IPIP;
380 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
381 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
382 
383 		if (ops->ndo_do_ioctl) {
384 			mm_segment_t oldfs = get_fs();
385 
386 			set_fs(KERNEL_DS);
387 			ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
388 			set_fs(oldfs);
389 		}
390 	}
391 }
392 
393 static
394 struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
395 {
396 	struct net_device  *dev;
397 
398 	dev = __dev_get_by_name(net, "tunl0");
399 
400 	if (dev) {
401 		const struct net_device_ops *ops = dev->netdev_ops;
402 		int err;
403 		struct ifreq ifr;
404 		struct ip_tunnel_parm p;
405 		struct in_device  *in_dev;
406 
407 		memset(&p, 0, sizeof(p));
408 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
409 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
410 		p.iph.version = 4;
411 		p.iph.ihl = 5;
412 		p.iph.protocol = IPPROTO_IPIP;
413 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
414 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
415 
416 		if (ops->ndo_do_ioctl) {
417 			mm_segment_t oldfs = get_fs();
418 
419 			set_fs(KERNEL_DS);
420 			err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
421 			set_fs(oldfs);
422 		} else {
423 			err = -EOPNOTSUPP;
424 		}
425 		dev = NULL;
426 
427 		if (err == 0 &&
428 		    (dev = __dev_get_by_name(net, p.name)) != NULL) {
429 			dev->flags |= IFF_MULTICAST;
430 
431 			in_dev = __in_dev_get_rtnl(dev);
432 			if (in_dev == NULL)
433 				goto failure;
434 
435 			ipv4_devconf_setall(in_dev);
436 			neigh_parms_data_state_setall(in_dev->arp_parms);
437 			IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
438 
439 			if (dev_open(dev))
440 				goto failure;
441 			dev_hold(dev);
442 		}
443 	}
444 	return dev;
445 
446 failure:
447 	/* allow the register to be completed before unregistering. */
448 	rtnl_unlock();
449 	rtnl_lock();
450 
451 	unregister_netdevice(dev);
452 	return NULL;
453 }
454 
455 #ifdef CONFIG_IP_PIMSM
456 
457 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
458 {
459 	struct net *net = dev_net(dev);
460 	struct mr_table *mrt;
461 	struct flowi4 fl4 = {
462 		.flowi4_oif	= dev->ifindex,
463 		.flowi4_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
464 		.flowi4_mark	= skb->mark,
465 	};
466 	int err;
467 
468 	err = ipmr_fib_lookup(net, &fl4, &mrt);
469 	if (err < 0) {
470 		kfree_skb(skb);
471 		return err;
472 	}
473 
474 	read_lock(&mrt_lock);
475 	dev->stats.tx_bytes += skb->len;
476 	dev->stats.tx_packets++;
477 	ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
478 	read_unlock(&mrt_lock);
479 	kfree_skb(skb);
480 	return NETDEV_TX_OK;
481 }
482 
483 static const struct net_device_ops reg_vif_netdev_ops = {
484 	.ndo_start_xmit	= reg_vif_xmit,
485 };
486 
487 static void reg_vif_setup(struct net_device *dev)
488 {
489 	dev->type		= ARPHRD_PIMREG;
490 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
491 	dev->flags		= IFF_NOARP;
492 	dev->netdev_ops		= &reg_vif_netdev_ops;
493 	dev->destructor		= free_netdev;
494 	dev->features		|= NETIF_F_NETNS_LOCAL;
495 }
496 
497 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
498 {
499 	struct net_device *dev;
500 	struct in_device *in_dev;
501 	char name[IFNAMSIZ];
502 
503 	if (mrt->id == RT_TABLE_DEFAULT)
504 		sprintf(name, "pimreg");
505 	else
506 		sprintf(name, "pimreg%u", mrt->id);
507 
508 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
509 
510 	if (dev == NULL)
511 		return NULL;
512 
513 	dev_net_set(dev, net);
514 
515 	if (register_netdevice(dev)) {
516 		free_netdev(dev);
517 		return NULL;
518 	}
519 	dev->iflink = 0;
520 
521 	rcu_read_lock();
522 	in_dev = __in_dev_get_rcu(dev);
523 	if (!in_dev) {
524 		rcu_read_unlock();
525 		goto failure;
526 	}
527 
528 	ipv4_devconf_setall(in_dev);
529 	neigh_parms_data_state_setall(in_dev->arp_parms);
530 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
531 	rcu_read_unlock();
532 
533 	if (dev_open(dev))
534 		goto failure;
535 
536 	dev_hold(dev);
537 
538 	return dev;
539 
540 failure:
541 	/* allow the register to be completed before unregistering. */
542 	rtnl_unlock();
543 	rtnl_lock();
544 
545 	unregister_netdevice(dev);
546 	return NULL;
547 }
548 #endif
549 
550 /**
551  *	vif_delete - Delete a VIF entry
552  *	@notify: Set to 1, if the caller is a notifier_call
553  */
554 
555 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
556 		      struct list_head *head)
557 {
558 	struct vif_device *v;
559 	struct net_device *dev;
560 	struct in_device *in_dev;
561 
562 	if (vifi < 0 || vifi >= mrt->maxvif)
563 		return -EADDRNOTAVAIL;
564 
565 	v = &mrt->vif_table[vifi];
566 
567 	write_lock_bh(&mrt_lock);
568 	dev = v->dev;
569 	v->dev = NULL;
570 
571 	if (!dev) {
572 		write_unlock_bh(&mrt_lock);
573 		return -EADDRNOTAVAIL;
574 	}
575 
576 #ifdef CONFIG_IP_PIMSM
577 	if (vifi == mrt->mroute_reg_vif_num)
578 		mrt->mroute_reg_vif_num = -1;
579 #endif
580 
581 	if (vifi + 1 == mrt->maxvif) {
582 		int tmp;
583 
584 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
585 			if (VIF_EXISTS(mrt, tmp))
586 				break;
587 		}
588 		mrt->maxvif = tmp+1;
589 	}
590 
591 	write_unlock_bh(&mrt_lock);
592 
593 	dev_set_allmulti(dev, -1);
594 
595 	in_dev = __in_dev_get_rtnl(dev);
596 	if (in_dev) {
597 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
598 		inet_netconf_notify_devconf(dev_net(dev),
599 					    NETCONFA_MC_FORWARDING,
600 					    dev->ifindex, &in_dev->cnf);
601 		ip_rt_multicast_event(in_dev);
602 	}
603 
604 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
605 		unregister_netdevice_queue(dev, head);
606 
607 	dev_put(dev);
608 	return 0;
609 }
610 
611 static void ipmr_cache_free_rcu(struct rcu_head *head)
612 {
613 	struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
614 
615 	kmem_cache_free(mrt_cachep, c);
616 }
617 
618 static inline void ipmr_cache_free(struct mfc_cache *c)
619 {
620 	call_rcu(&c->rcu, ipmr_cache_free_rcu);
621 }
622 
623 /* Destroy an unresolved cache entry, killing queued skbs
624  * and reporting error to netlink readers.
625  */
626 
627 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
628 {
629 	struct net *net = read_pnet(&mrt->net);
630 	struct sk_buff *skb;
631 	struct nlmsgerr *e;
632 
633 	atomic_dec(&mrt->cache_resolve_queue_len);
634 
635 	while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
636 		if (ip_hdr(skb)->version == 0) {
637 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
638 			nlh->nlmsg_type = NLMSG_ERROR;
639 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
640 			skb_trim(skb, nlh->nlmsg_len);
641 			e = nlmsg_data(nlh);
642 			e->error = -ETIMEDOUT;
643 			memset(&e->msg, 0, sizeof(e->msg));
644 
645 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
646 		} else {
647 			kfree_skb(skb);
648 		}
649 	}
650 
651 	ipmr_cache_free(c);
652 }
653 
654 
655 /* Timer process for the unresolved queue. */
656 
657 static void ipmr_expire_process(unsigned long arg)
658 {
659 	struct mr_table *mrt = (struct mr_table *)arg;
660 	unsigned long now;
661 	unsigned long expires;
662 	struct mfc_cache *c, *next;
663 
664 	if (!spin_trylock(&mfc_unres_lock)) {
665 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
666 		return;
667 	}
668 
669 	if (list_empty(&mrt->mfc_unres_queue))
670 		goto out;
671 
672 	now = jiffies;
673 	expires = 10*HZ;
674 
675 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
676 		if (time_after(c->mfc_un.unres.expires, now)) {
677 			unsigned long interval = c->mfc_un.unres.expires - now;
678 			if (interval < expires)
679 				expires = interval;
680 			continue;
681 		}
682 
683 		list_del(&c->list);
684 		mroute_netlink_event(mrt, c, RTM_DELROUTE);
685 		ipmr_destroy_unres(mrt, c);
686 	}
687 
688 	if (!list_empty(&mrt->mfc_unres_queue))
689 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
690 
691 out:
692 	spin_unlock(&mfc_unres_lock);
693 }
694 
695 /* Fill oifs list. It is called under write locked mrt_lock. */
696 
697 static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
698 				   unsigned char *ttls)
699 {
700 	int vifi;
701 
702 	cache->mfc_un.res.minvif = MAXVIFS;
703 	cache->mfc_un.res.maxvif = 0;
704 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
705 
706 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
707 		if (VIF_EXISTS(mrt, vifi) &&
708 		    ttls[vifi] && ttls[vifi] < 255) {
709 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
710 			if (cache->mfc_un.res.minvif > vifi)
711 				cache->mfc_un.res.minvif = vifi;
712 			if (cache->mfc_un.res.maxvif <= vifi)
713 				cache->mfc_un.res.maxvif = vifi + 1;
714 		}
715 	}
716 }
717 
718 static int vif_add(struct net *net, struct mr_table *mrt,
719 		   struct vifctl *vifc, int mrtsock)
720 {
721 	int vifi = vifc->vifc_vifi;
722 	struct vif_device *v = &mrt->vif_table[vifi];
723 	struct net_device *dev;
724 	struct in_device *in_dev;
725 	int err;
726 
727 	/* Is vif busy ? */
728 	if (VIF_EXISTS(mrt, vifi))
729 		return -EADDRINUSE;
730 
731 	switch (vifc->vifc_flags) {
732 #ifdef CONFIG_IP_PIMSM
733 	case VIFF_REGISTER:
734 		/*
735 		 * Special Purpose VIF in PIM
736 		 * All the packets will be sent to the daemon
737 		 */
738 		if (mrt->mroute_reg_vif_num >= 0)
739 			return -EADDRINUSE;
740 		dev = ipmr_reg_vif(net, mrt);
741 		if (!dev)
742 			return -ENOBUFS;
743 		err = dev_set_allmulti(dev, 1);
744 		if (err) {
745 			unregister_netdevice(dev);
746 			dev_put(dev);
747 			return err;
748 		}
749 		break;
750 #endif
751 	case VIFF_TUNNEL:
752 		dev = ipmr_new_tunnel(net, vifc);
753 		if (!dev)
754 			return -ENOBUFS;
755 		err = dev_set_allmulti(dev, 1);
756 		if (err) {
757 			ipmr_del_tunnel(dev, vifc);
758 			dev_put(dev);
759 			return err;
760 		}
761 		break;
762 
763 	case VIFF_USE_IFINDEX:
764 	case 0:
765 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
766 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
767 			if (dev && __in_dev_get_rtnl(dev) == NULL) {
768 				dev_put(dev);
769 				return -EADDRNOTAVAIL;
770 			}
771 		} else {
772 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
773 		}
774 		if (!dev)
775 			return -EADDRNOTAVAIL;
776 		err = dev_set_allmulti(dev, 1);
777 		if (err) {
778 			dev_put(dev);
779 			return err;
780 		}
781 		break;
782 	default:
783 		return -EINVAL;
784 	}
785 
786 	in_dev = __in_dev_get_rtnl(dev);
787 	if (!in_dev) {
788 		dev_put(dev);
789 		return -EADDRNOTAVAIL;
790 	}
791 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
792 	inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING, dev->ifindex,
793 				    &in_dev->cnf);
794 	ip_rt_multicast_event(in_dev);
795 
796 	/* Fill in the VIF structures */
797 
798 	v->rate_limit = vifc->vifc_rate_limit;
799 	v->local = vifc->vifc_lcl_addr.s_addr;
800 	v->remote = vifc->vifc_rmt_addr.s_addr;
801 	v->flags = vifc->vifc_flags;
802 	if (!mrtsock)
803 		v->flags |= VIFF_STATIC;
804 	v->threshold = vifc->vifc_threshold;
805 	v->bytes_in = 0;
806 	v->bytes_out = 0;
807 	v->pkt_in = 0;
808 	v->pkt_out = 0;
809 	v->link = dev->ifindex;
810 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
811 		v->link = dev->iflink;
812 
813 	/* And finish update writing critical data */
814 	write_lock_bh(&mrt_lock);
815 	v->dev = dev;
816 #ifdef CONFIG_IP_PIMSM
817 	if (v->flags & VIFF_REGISTER)
818 		mrt->mroute_reg_vif_num = vifi;
819 #endif
820 	if (vifi+1 > mrt->maxvif)
821 		mrt->maxvif = vifi+1;
822 	write_unlock_bh(&mrt_lock);
823 	return 0;
824 }
825 
826 /* called with rcu_read_lock() */
827 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
828 					 __be32 origin,
829 					 __be32 mcastgrp)
830 {
831 	int line = MFC_HASH(mcastgrp, origin);
832 	struct mfc_cache *c;
833 
834 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list) {
835 		if (c->mfc_origin == origin && c->mfc_mcastgrp == mcastgrp)
836 			return c;
837 	}
838 	return NULL;
839 }
840 
841 /* Look for a (*,*,oif) entry */
842 static struct mfc_cache *ipmr_cache_find_any_parent(struct mr_table *mrt,
843 						    int vifi)
844 {
845 	int line = MFC_HASH(htonl(INADDR_ANY), htonl(INADDR_ANY));
846 	struct mfc_cache *c;
847 
848 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list)
849 		if (c->mfc_origin == htonl(INADDR_ANY) &&
850 		    c->mfc_mcastgrp == htonl(INADDR_ANY) &&
851 		    c->mfc_un.res.ttls[vifi] < 255)
852 			return c;
853 
854 	return NULL;
855 }
856 
857 /* Look for a (*,G) entry */
858 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
859 					     __be32 mcastgrp, int vifi)
860 {
861 	int line = MFC_HASH(mcastgrp, htonl(INADDR_ANY));
862 	struct mfc_cache *c, *proxy;
863 
864 	if (mcastgrp == htonl(INADDR_ANY))
865 		goto skip;
866 
867 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list)
868 		if (c->mfc_origin == htonl(INADDR_ANY) &&
869 		    c->mfc_mcastgrp == mcastgrp) {
870 			if (c->mfc_un.res.ttls[vifi] < 255)
871 				return c;
872 
873 			/* It's ok if the vifi is part of the static tree */
874 			proxy = ipmr_cache_find_any_parent(mrt,
875 							   c->mfc_parent);
876 			if (proxy && proxy->mfc_un.res.ttls[vifi] < 255)
877 				return c;
878 		}
879 
880 skip:
881 	return ipmr_cache_find_any_parent(mrt, vifi);
882 }
883 
884 /*
885  *	Allocate a multicast cache entry
886  */
887 static struct mfc_cache *ipmr_cache_alloc(void)
888 {
889 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
890 
891 	if (c)
892 		c->mfc_un.res.minvif = MAXVIFS;
893 	return c;
894 }
895 
896 static struct mfc_cache *ipmr_cache_alloc_unres(void)
897 {
898 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
899 
900 	if (c) {
901 		skb_queue_head_init(&c->mfc_un.unres.unresolved);
902 		c->mfc_un.unres.expires = jiffies + 10*HZ;
903 	}
904 	return c;
905 }
906 
907 /*
908  *	A cache entry has gone into a resolved state from queued
909  */
910 
911 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
912 			       struct mfc_cache *uc, struct mfc_cache *c)
913 {
914 	struct sk_buff *skb;
915 	struct nlmsgerr *e;
916 
917 	/* Play the pending entries through our router */
918 
919 	while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
920 		if (ip_hdr(skb)->version == 0) {
921 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
922 
923 			if (__ipmr_fill_mroute(mrt, skb, c, nlmsg_data(nlh)) > 0) {
924 				nlh->nlmsg_len = skb_tail_pointer(skb) -
925 						 (u8 *)nlh;
926 			} else {
927 				nlh->nlmsg_type = NLMSG_ERROR;
928 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
929 				skb_trim(skb, nlh->nlmsg_len);
930 				e = nlmsg_data(nlh);
931 				e->error = -EMSGSIZE;
932 				memset(&e->msg, 0, sizeof(e->msg));
933 			}
934 
935 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
936 		} else {
937 			ip_mr_forward(net, mrt, skb, c, 0);
938 		}
939 	}
940 }
941 
942 /*
943  *	Bounce a cache query up to mrouted. We could use netlink for this but mrouted
944  *	expects the following bizarre scheme.
945  *
946  *	Called under mrt_lock.
947  */
948 
949 static int ipmr_cache_report(struct mr_table *mrt,
950 			     struct sk_buff *pkt, vifi_t vifi, int assert)
951 {
952 	struct sk_buff *skb;
953 	const int ihl = ip_hdrlen(pkt);
954 	struct igmphdr *igmp;
955 	struct igmpmsg *msg;
956 	struct sock *mroute_sk;
957 	int ret;
958 
959 #ifdef CONFIG_IP_PIMSM
960 	if (assert == IGMPMSG_WHOLEPKT)
961 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
962 	else
963 #endif
964 		skb = alloc_skb(128, GFP_ATOMIC);
965 
966 	if (!skb)
967 		return -ENOBUFS;
968 
969 #ifdef CONFIG_IP_PIMSM
970 	if (assert == IGMPMSG_WHOLEPKT) {
971 		/* Ugly, but we have no choice with this interface.
972 		 * Duplicate old header, fix ihl, length etc.
973 		 * And all this only to mangle msg->im_msgtype and
974 		 * to set msg->im_mbz to "mbz" :-)
975 		 */
976 		skb_push(skb, sizeof(struct iphdr));
977 		skb_reset_network_header(skb);
978 		skb_reset_transport_header(skb);
979 		msg = (struct igmpmsg *)skb_network_header(skb);
980 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
981 		msg->im_msgtype = IGMPMSG_WHOLEPKT;
982 		msg->im_mbz = 0;
983 		msg->im_vif = mrt->mroute_reg_vif_num;
984 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
985 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
986 					     sizeof(struct iphdr));
987 	} else
988 #endif
989 	{
990 
991 	/* Copy the IP header */
992 
993 	skb_set_network_header(skb, skb->len);
994 	skb_put(skb, ihl);
995 	skb_copy_to_linear_data(skb, pkt->data, ihl);
996 	ip_hdr(skb)->protocol = 0;	/* Flag to the kernel this is a route add */
997 	msg = (struct igmpmsg *)skb_network_header(skb);
998 	msg->im_vif = vifi;
999 	skb_dst_set(skb, dst_clone(skb_dst(pkt)));
1000 
1001 	/* Add our header */
1002 
1003 	igmp = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
1004 	igmp->type	=
1005 	msg->im_msgtype = assert;
1006 	igmp->code	= 0;
1007 	ip_hdr(skb)->tot_len = htons(skb->len);		/* Fix the length */
1008 	skb->transport_header = skb->network_header;
1009 	}
1010 
1011 	rcu_read_lock();
1012 	mroute_sk = rcu_dereference(mrt->mroute_sk);
1013 	if (mroute_sk == NULL) {
1014 		rcu_read_unlock();
1015 		kfree_skb(skb);
1016 		return -EINVAL;
1017 	}
1018 
1019 	/* Deliver to mrouted */
1020 
1021 	ret = sock_queue_rcv_skb(mroute_sk, skb);
1022 	rcu_read_unlock();
1023 	if (ret < 0) {
1024 		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1025 		kfree_skb(skb);
1026 	}
1027 
1028 	return ret;
1029 }
1030 
1031 /*
1032  *	Queue a packet for resolution. It gets locked cache entry!
1033  */
1034 
1035 static int
1036 ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi, struct sk_buff *skb)
1037 {
1038 	bool found = false;
1039 	int err;
1040 	struct mfc_cache *c;
1041 	const struct iphdr *iph = ip_hdr(skb);
1042 
1043 	spin_lock_bh(&mfc_unres_lock);
1044 	list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
1045 		if (c->mfc_mcastgrp == iph->daddr &&
1046 		    c->mfc_origin == iph->saddr) {
1047 			found = true;
1048 			break;
1049 		}
1050 	}
1051 
1052 	if (!found) {
1053 		/* Create a new entry if allowable */
1054 
1055 		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
1056 		    (c = ipmr_cache_alloc_unres()) == NULL) {
1057 			spin_unlock_bh(&mfc_unres_lock);
1058 
1059 			kfree_skb(skb);
1060 			return -ENOBUFS;
1061 		}
1062 
1063 		/* Fill in the new cache entry */
1064 
1065 		c->mfc_parent	= -1;
1066 		c->mfc_origin	= iph->saddr;
1067 		c->mfc_mcastgrp	= iph->daddr;
1068 
1069 		/* Reflect first query at mrouted. */
1070 
1071 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1072 		if (err < 0) {
1073 			/* If the report failed throw the cache entry
1074 			   out - Brad Parker
1075 			 */
1076 			spin_unlock_bh(&mfc_unres_lock);
1077 
1078 			ipmr_cache_free(c);
1079 			kfree_skb(skb);
1080 			return err;
1081 		}
1082 
1083 		atomic_inc(&mrt->cache_resolve_queue_len);
1084 		list_add(&c->list, &mrt->mfc_unres_queue);
1085 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1086 
1087 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1088 			mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1089 	}
1090 
1091 	/* See if we can append the packet */
1092 
1093 	if (c->mfc_un.unres.unresolved.qlen > 3) {
1094 		kfree_skb(skb);
1095 		err = -ENOBUFS;
1096 	} else {
1097 		skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1098 		err = 0;
1099 	}
1100 
1101 	spin_unlock_bh(&mfc_unres_lock);
1102 	return err;
1103 }
1104 
1105 /*
1106  *	MFC cache manipulation by user space mroute daemon
1107  */
1108 
1109 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1110 {
1111 	int line;
1112 	struct mfc_cache *c, *next;
1113 
1114 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1115 
1116 	list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[line], list) {
1117 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1118 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr &&
1119 		    (parent == -1 || parent == c->mfc_parent)) {
1120 			list_del_rcu(&c->list);
1121 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1122 			ipmr_cache_free(c);
1123 			return 0;
1124 		}
1125 	}
1126 	return -ENOENT;
1127 }
1128 
1129 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1130 			struct mfcctl *mfc, int mrtsock, int parent)
1131 {
1132 	bool found = false;
1133 	int line;
1134 	struct mfc_cache *uc, *c;
1135 
1136 	if (mfc->mfcc_parent >= MAXVIFS)
1137 		return -ENFILE;
1138 
1139 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1140 
1141 	list_for_each_entry(c, &mrt->mfc_cache_array[line], list) {
1142 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1143 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr &&
1144 		    (parent == -1 || parent == c->mfc_parent)) {
1145 			found = true;
1146 			break;
1147 		}
1148 	}
1149 
1150 	if (found) {
1151 		write_lock_bh(&mrt_lock);
1152 		c->mfc_parent = mfc->mfcc_parent;
1153 		ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1154 		if (!mrtsock)
1155 			c->mfc_flags |= MFC_STATIC;
1156 		write_unlock_bh(&mrt_lock);
1157 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1158 		return 0;
1159 	}
1160 
1161 	if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1162 	    !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1163 		return -EINVAL;
1164 
1165 	c = ipmr_cache_alloc();
1166 	if (c == NULL)
1167 		return -ENOMEM;
1168 
1169 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1170 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1171 	c->mfc_parent = mfc->mfcc_parent;
1172 	ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1173 	if (!mrtsock)
1174 		c->mfc_flags |= MFC_STATIC;
1175 
1176 	list_add_rcu(&c->list, &mrt->mfc_cache_array[line]);
1177 
1178 	/*
1179 	 *	Check to see if we resolved a queued list. If so we
1180 	 *	need to send on the frames and tidy up.
1181 	 */
1182 	found = false;
1183 	spin_lock_bh(&mfc_unres_lock);
1184 	list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1185 		if (uc->mfc_origin == c->mfc_origin &&
1186 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1187 			list_del(&uc->list);
1188 			atomic_dec(&mrt->cache_resolve_queue_len);
1189 			found = true;
1190 			break;
1191 		}
1192 	}
1193 	if (list_empty(&mrt->mfc_unres_queue))
1194 		del_timer(&mrt->ipmr_expire_timer);
1195 	spin_unlock_bh(&mfc_unres_lock);
1196 
1197 	if (found) {
1198 		ipmr_cache_resolve(net, mrt, uc, c);
1199 		ipmr_cache_free(uc);
1200 	}
1201 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1202 	return 0;
1203 }
1204 
1205 /*
1206  *	Close the multicast socket, and clear the vif tables etc
1207  */
1208 
1209 static void mroute_clean_tables(struct mr_table *mrt)
1210 {
1211 	int i;
1212 	LIST_HEAD(list);
1213 	struct mfc_cache *c, *next;
1214 
1215 	/* Shut down all active vif entries */
1216 
1217 	for (i = 0; i < mrt->maxvif; i++) {
1218 		if (!(mrt->vif_table[i].flags & VIFF_STATIC))
1219 			vif_delete(mrt, i, 0, &list);
1220 	}
1221 	unregister_netdevice_many(&list);
1222 
1223 	/* Wipe the cache */
1224 
1225 	for (i = 0; i < MFC_LINES; i++) {
1226 		list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[i], list) {
1227 			if (c->mfc_flags & MFC_STATIC)
1228 				continue;
1229 			list_del_rcu(&c->list);
1230 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1231 			ipmr_cache_free(c);
1232 		}
1233 	}
1234 
1235 	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1236 		spin_lock_bh(&mfc_unres_lock);
1237 		list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
1238 			list_del(&c->list);
1239 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1240 			ipmr_destroy_unres(mrt, c);
1241 		}
1242 		spin_unlock_bh(&mfc_unres_lock);
1243 	}
1244 }
1245 
1246 /* called from ip_ra_control(), before an RCU grace period,
1247  * we dont need to call synchronize_rcu() here
1248  */
1249 static void mrtsock_destruct(struct sock *sk)
1250 {
1251 	struct net *net = sock_net(sk);
1252 	struct mr_table *mrt;
1253 
1254 	rtnl_lock();
1255 	ipmr_for_each_table(mrt, net) {
1256 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1257 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1258 			inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1259 						    NETCONFA_IFINDEX_ALL,
1260 						    net->ipv4.devconf_all);
1261 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1262 			mroute_clean_tables(mrt);
1263 		}
1264 	}
1265 	rtnl_unlock();
1266 }
1267 
1268 /*
1269  *	Socket options and virtual interface manipulation. The whole
1270  *	virtual interface system is a complete heap, but unfortunately
1271  *	that's how BSD mrouted happens to think. Maybe one day with a proper
1272  *	MOSPF/PIM router set up we can clean this up.
1273  */
1274 
1275 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen)
1276 {
1277 	int ret, parent = 0;
1278 	struct vifctl vif;
1279 	struct mfcctl mfc;
1280 	struct net *net = sock_net(sk);
1281 	struct mr_table *mrt;
1282 
1283 	if (sk->sk_type != SOCK_RAW ||
1284 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1285 		return -EOPNOTSUPP;
1286 
1287 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1288 	if (mrt == NULL)
1289 		return -ENOENT;
1290 
1291 	if (optname != MRT_INIT) {
1292 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1293 		    !ns_capable(net->user_ns, CAP_NET_ADMIN))
1294 			return -EACCES;
1295 	}
1296 
1297 	switch (optname) {
1298 	case MRT_INIT:
1299 		if (optlen != sizeof(int))
1300 			return -EINVAL;
1301 
1302 		rtnl_lock();
1303 		if (rtnl_dereference(mrt->mroute_sk)) {
1304 			rtnl_unlock();
1305 			return -EADDRINUSE;
1306 		}
1307 
1308 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1309 		if (ret == 0) {
1310 			rcu_assign_pointer(mrt->mroute_sk, sk);
1311 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1312 			inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1313 						    NETCONFA_IFINDEX_ALL,
1314 						    net->ipv4.devconf_all);
1315 		}
1316 		rtnl_unlock();
1317 		return ret;
1318 	case MRT_DONE:
1319 		if (sk != rcu_access_pointer(mrt->mroute_sk))
1320 			return -EACCES;
1321 		return ip_ra_control(sk, 0, NULL);
1322 	case MRT_ADD_VIF:
1323 	case MRT_DEL_VIF:
1324 		if (optlen != sizeof(vif))
1325 			return -EINVAL;
1326 		if (copy_from_user(&vif, optval, sizeof(vif)))
1327 			return -EFAULT;
1328 		if (vif.vifc_vifi >= MAXVIFS)
1329 			return -ENFILE;
1330 		rtnl_lock();
1331 		if (optname == MRT_ADD_VIF) {
1332 			ret = vif_add(net, mrt, &vif,
1333 				      sk == rtnl_dereference(mrt->mroute_sk));
1334 		} else {
1335 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1336 		}
1337 		rtnl_unlock();
1338 		return ret;
1339 
1340 		/*
1341 		 *	Manipulate the forwarding caches. These live
1342 		 *	in a sort of kernel/user symbiosis.
1343 		 */
1344 	case MRT_ADD_MFC:
1345 	case MRT_DEL_MFC:
1346 		parent = -1;
1347 	case MRT_ADD_MFC_PROXY:
1348 	case MRT_DEL_MFC_PROXY:
1349 		if (optlen != sizeof(mfc))
1350 			return -EINVAL;
1351 		if (copy_from_user(&mfc, optval, sizeof(mfc)))
1352 			return -EFAULT;
1353 		if (parent == 0)
1354 			parent = mfc.mfcc_parent;
1355 		rtnl_lock();
1356 		if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1357 			ret = ipmr_mfc_delete(mrt, &mfc, parent);
1358 		else
1359 			ret = ipmr_mfc_add(net, mrt, &mfc,
1360 					   sk == rtnl_dereference(mrt->mroute_sk),
1361 					   parent);
1362 		rtnl_unlock();
1363 		return ret;
1364 		/*
1365 		 *	Control PIM assert.
1366 		 */
1367 	case MRT_ASSERT:
1368 	{
1369 		int v;
1370 		if (optlen != sizeof(v))
1371 			return -EINVAL;
1372 		if (get_user(v, (int __user *)optval))
1373 			return -EFAULT;
1374 		mrt->mroute_do_assert = v;
1375 		return 0;
1376 	}
1377 #ifdef CONFIG_IP_PIMSM
1378 	case MRT_PIM:
1379 	{
1380 		int v;
1381 
1382 		if (optlen != sizeof(v))
1383 			return -EINVAL;
1384 		if (get_user(v, (int __user *)optval))
1385 			return -EFAULT;
1386 		v = !!v;
1387 
1388 		rtnl_lock();
1389 		ret = 0;
1390 		if (v != mrt->mroute_do_pim) {
1391 			mrt->mroute_do_pim = v;
1392 			mrt->mroute_do_assert = v;
1393 		}
1394 		rtnl_unlock();
1395 		return ret;
1396 	}
1397 #endif
1398 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
1399 	case MRT_TABLE:
1400 	{
1401 		u32 v;
1402 
1403 		if (optlen != sizeof(u32))
1404 			return -EINVAL;
1405 		if (get_user(v, (u32 __user *)optval))
1406 			return -EFAULT;
1407 
1408 		/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
1409 		if (v != RT_TABLE_DEFAULT && v >= 1000000000)
1410 			return -EINVAL;
1411 
1412 		rtnl_lock();
1413 		ret = 0;
1414 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1415 			ret = -EBUSY;
1416 		} else {
1417 			if (!ipmr_new_table(net, v))
1418 				ret = -ENOMEM;
1419 			else
1420 				raw_sk(sk)->ipmr_table = v;
1421 		}
1422 		rtnl_unlock();
1423 		return ret;
1424 	}
1425 #endif
1426 	/*
1427 	 *	Spurious command, or MRT_VERSION which you cannot
1428 	 *	set.
1429 	 */
1430 	default:
1431 		return -ENOPROTOOPT;
1432 	}
1433 }
1434 
1435 /*
1436  *	Getsock opt support for the multicast routing system.
1437  */
1438 
1439 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1440 {
1441 	int olr;
1442 	int val;
1443 	struct net *net = sock_net(sk);
1444 	struct mr_table *mrt;
1445 
1446 	if (sk->sk_type != SOCK_RAW ||
1447 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1448 		return -EOPNOTSUPP;
1449 
1450 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1451 	if (mrt == NULL)
1452 		return -ENOENT;
1453 
1454 	if (optname != MRT_VERSION &&
1455 #ifdef CONFIG_IP_PIMSM
1456 	   optname != MRT_PIM &&
1457 #endif
1458 	   optname != MRT_ASSERT)
1459 		return -ENOPROTOOPT;
1460 
1461 	if (get_user(olr, optlen))
1462 		return -EFAULT;
1463 
1464 	olr = min_t(unsigned int, olr, sizeof(int));
1465 	if (olr < 0)
1466 		return -EINVAL;
1467 
1468 	if (put_user(olr, optlen))
1469 		return -EFAULT;
1470 	if (optname == MRT_VERSION)
1471 		val = 0x0305;
1472 #ifdef CONFIG_IP_PIMSM
1473 	else if (optname == MRT_PIM)
1474 		val = mrt->mroute_do_pim;
1475 #endif
1476 	else
1477 		val = mrt->mroute_do_assert;
1478 	if (copy_to_user(optval, &val, olr))
1479 		return -EFAULT;
1480 	return 0;
1481 }
1482 
1483 /*
1484  *	The IP multicast ioctl support routines.
1485  */
1486 
1487 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1488 {
1489 	struct sioc_sg_req sr;
1490 	struct sioc_vif_req vr;
1491 	struct vif_device *vif;
1492 	struct mfc_cache *c;
1493 	struct net *net = sock_net(sk);
1494 	struct mr_table *mrt;
1495 
1496 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1497 	if (mrt == NULL)
1498 		return -ENOENT;
1499 
1500 	switch (cmd) {
1501 	case SIOCGETVIFCNT:
1502 		if (copy_from_user(&vr, arg, sizeof(vr)))
1503 			return -EFAULT;
1504 		if (vr.vifi >= mrt->maxvif)
1505 			return -EINVAL;
1506 		read_lock(&mrt_lock);
1507 		vif = &mrt->vif_table[vr.vifi];
1508 		if (VIF_EXISTS(mrt, vr.vifi)) {
1509 			vr.icount = vif->pkt_in;
1510 			vr.ocount = vif->pkt_out;
1511 			vr.ibytes = vif->bytes_in;
1512 			vr.obytes = vif->bytes_out;
1513 			read_unlock(&mrt_lock);
1514 
1515 			if (copy_to_user(arg, &vr, sizeof(vr)))
1516 				return -EFAULT;
1517 			return 0;
1518 		}
1519 		read_unlock(&mrt_lock);
1520 		return -EADDRNOTAVAIL;
1521 	case SIOCGETSGCNT:
1522 		if (copy_from_user(&sr, arg, sizeof(sr)))
1523 			return -EFAULT;
1524 
1525 		rcu_read_lock();
1526 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1527 		if (c) {
1528 			sr.pktcnt = c->mfc_un.res.pkt;
1529 			sr.bytecnt = c->mfc_un.res.bytes;
1530 			sr.wrong_if = c->mfc_un.res.wrong_if;
1531 			rcu_read_unlock();
1532 
1533 			if (copy_to_user(arg, &sr, sizeof(sr)))
1534 				return -EFAULT;
1535 			return 0;
1536 		}
1537 		rcu_read_unlock();
1538 		return -EADDRNOTAVAIL;
1539 	default:
1540 		return -ENOIOCTLCMD;
1541 	}
1542 }
1543 
1544 #ifdef CONFIG_COMPAT
1545 struct compat_sioc_sg_req {
1546 	struct in_addr src;
1547 	struct in_addr grp;
1548 	compat_ulong_t pktcnt;
1549 	compat_ulong_t bytecnt;
1550 	compat_ulong_t wrong_if;
1551 };
1552 
1553 struct compat_sioc_vif_req {
1554 	vifi_t	vifi;		/* Which iface */
1555 	compat_ulong_t icount;
1556 	compat_ulong_t ocount;
1557 	compat_ulong_t ibytes;
1558 	compat_ulong_t obytes;
1559 };
1560 
1561 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1562 {
1563 	struct compat_sioc_sg_req sr;
1564 	struct compat_sioc_vif_req vr;
1565 	struct vif_device *vif;
1566 	struct mfc_cache *c;
1567 	struct net *net = sock_net(sk);
1568 	struct mr_table *mrt;
1569 
1570 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1571 	if (mrt == NULL)
1572 		return -ENOENT;
1573 
1574 	switch (cmd) {
1575 	case SIOCGETVIFCNT:
1576 		if (copy_from_user(&vr, arg, sizeof(vr)))
1577 			return -EFAULT;
1578 		if (vr.vifi >= mrt->maxvif)
1579 			return -EINVAL;
1580 		read_lock(&mrt_lock);
1581 		vif = &mrt->vif_table[vr.vifi];
1582 		if (VIF_EXISTS(mrt, vr.vifi)) {
1583 			vr.icount = vif->pkt_in;
1584 			vr.ocount = vif->pkt_out;
1585 			vr.ibytes = vif->bytes_in;
1586 			vr.obytes = vif->bytes_out;
1587 			read_unlock(&mrt_lock);
1588 
1589 			if (copy_to_user(arg, &vr, sizeof(vr)))
1590 				return -EFAULT;
1591 			return 0;
1592 		}
1593 		read_unlock(&mrt_lock);
1594 		return -EADDRNOTAVAIL;
1595 	case SIOCGETSGCNT:
1596 		if (copy_from_user(&sr, arg, sizeof(sr)))
1597 			return -EFAULT;
1598 
1599 		rcu_read_lock();
1600 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1601 		if (c) {
1602 			sr.pktcnt = c->mfc_un.res.pkt;
1603 			sr.bytecnt = c->mfc_un.res.bytes;
1604 			sr.wrong_if = c->mfc_un.res.wrong_if;
1605 			rcu_read_unlock();
1606 
1607 			if (copy_to_user(arg, &sr, sizeof(sr)))
1608 				return -EFAULT;
1609 			return 0;
1610 		}
1611 		rcu_read_unlock();
1612 		return -EADDRNOTAVAIL;
1613 	default:
1614 		return -ENOIOCTLCMD;
1615 	}
1616 }
1617 #endif
1618 
1619 
1620 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1621 {
1622 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1623 	struct net *net = dev_net(dev);
1624 	struct mr_table *mrt;
1625 	struct vif_device *v;
1626 	int ct;
1627 
1628 	if (event != NETDEV_UNREGISTER)
1629 		return NOTIFY_DONE;
1630 
1631 	ipmr_for_each_table(mrt, net) {
1632 		v = &mrt->vif_table[0];
1633 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1634 			if (v->dev == dev)
1635 				vif_delete(mrt, ct, 1, NULL);
1636 		}
1637 	}
1638 	return NOTIFY_DONE;
1639 }
1640 
1641 
1642 static struct notifier_block ip_mr_notifier = {
1643 	.notifier_call = ipmr_device_event,
1644 };
1645 
1646 /*
1647  *	Encapsulate a packet by attaching a valid IPIP header to it.
1648  *	This avoids tunnel drivers and other mess and gives us the speed so
1649  *	important for multicast video.
1650  */
1651 
1652 static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr)
1653 {
1654 	struct iphdr *iph;
1655 	const struct iphdr *old_iph = ip_hdr(skb);
1656 
1657 	skb_push(skb, sizeof(struct iphdr));
1658 	skb->transport_header = skb->network_header;
1659 	skb_reset_network_header(skb);
1660 	iph = ip_hdr(skb);
1661 
1662 	iph->version	=	4;
1663 	iph->tos	=	old_iph->tos;
1664 	iph->ttl	=	old_iph->ttl;
1665 	iph->frag_off	=	0;
1666 	iph->daddr	=	daddr;
1667 	iph->saddr	=	saddr;
1668 	iph->protocol	=	IPPROTO_IPIP;
1669 	iph->ihl	=	5;
1670 	iph->tot_len	=	htons(skb->len);
1671 	ip_select_ident(skb, NULL);
1672 	ip_send_check(iph);
1673 
1674 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1675 	nf_reset(skb);
1676 }
1677 
1678 static inline int ipmr_forward_finish(struct sk_buff *skb)
1679 {
1680 	struct ip_options *opt = &(IPCB(skb)->opt);
1681 
1682 	IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
1683 	IP_ADD_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTOCTETS, skb->len);
1684 
1685 	if (unlikely(opt->optlen))
1686 		ip_forward_options(skb);
1687 
1688 	return dst_output(skb);
1689 }
1690 
1691 /*
1692  *	Processing handlers for ipmr_forward
1693  */
1694 
1695 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1696 			    struct sk_buff *skb, struct mfc_cache *c, int vifi)
1697 {
1698 	const struct iphdr *iph = ip_hdr(skb);
1699 	struct vif_device *vif = &mrt->vif_table[vifi];
1700 	struct net_device *dev;
1701 	struct rtable *rt;
1702 	struct flowi4 fl4;
1703 	int    encap = 0;
1704 
1705 	if (vif->dev == NULL)
1706 		goto out_free;
1707 
1708 #ifdef CONFIG_IP_PIMSM
1709 	if (vif->flags & VIFF_REGISTER) {
1710 		vif->pkt_out++;
1711 		vif->bytes_out += skb->len;
1712 		vif->dev->stats.tx_bytes += skb->len;
1713 		vif->dev->stats.tx_packets++;
1714 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1715 		goto out_free;
1716 	}
1717 #endif
1718 
1719 	if (vif->flags & VIFF_TUNNEL) {
1720 		rt = ip_route_output_ports(net, &fl4, NULL,
1721 					   vif->remote, vif->local,
1722 					   0, 0,
1723 					   IPPROTO_IPIP,
1724 					   RT_TOS(iph->tos), vif->link);
1725 		if (IS_ERR(rt))
1726 			goto out_free;
1727 		encap = sizeof(struct iphdr);
1728 	} else {
1729 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1730 					   0, 0,
1731 					   IPPROTO_IPIP,
1732 					   RT_TOS(iph->tos), vif->link);
1733 		if (IS_ERR(rt))
1734 			goto out_free;
1735 	}
1736 
1737 	dev = rt->dst.dev;
1738 
1739 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1740 		/* Do not fragment multicasts. Alas, IPv4 does not
1741 		 * allow to send ICMP, so that packets will disappear
1742 		 * to blackhole.
1743 		 */
1744 
1745 		IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
1746 		ip_rt_put(rt);
1747 		goto out_free;
1748 	}
1749 
1750 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1751 
1752 	if (skb_cow(skb, encap)) {
1753 		ip_rt_put(rt);
1754 		goto out_free;
1755 	}
1756 
1757 	vif->pkt_out++;
1758 	vif->bytes_out += skb->len;
1759 
1760 	skb_dst_drop(skb);
1761 	skb_dst_set(skb, &rt->dst);
1762 	ip_decrease_ttl(ip_hdr(skb));
1763 
1764 	/* FIXME: forward and output firewalls used to be called here.
1765 	 * What do we do with netfilter? -- RR
1766 	 */
1767 	if (vif->flags & VIFF_TUNNEL) {
1768 		ip_encap(skb, vif->local, vif->remote);
1769 		/* FIXME: extra output firewall step used to be here. --RR */
1770 		vif->dev->stats.tx_packets++;
1771 		vif->dev->stats.tx_bytes += skb->len;
1772 	}
1773 
1774 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1775 
1776 	/*
1777 	 * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1778 	 * not only before forwarding, but after forwarding on all output
1779 	 * interfaces. It is clear, if mrouter runs a multicasting
1780 	 * program, it should receive packets not depending to what interface
1781 	 * program is joined.
1782 	 * If we will not make it, the program will have to join on all
1783 	 * interfaces. On the other hand, multihoming host (or router, but
1784 	 * not mrouter) cannot join to more than one interface - it will
1785 	 * result in receiving multiple packets.
1786 	 */
1787 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, skb, skb->dev, dev,
1788 		ipmr_forward_finish);
1789 	return;
1790 
1791 out_free:
1792 	kfree_skb(skb);
1793 }
1794 
1795 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1796 {
1797 	int ct;
1798 
1799 	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1800 		if (mrt->vif_table[ct].dev == dev)
1801 			break;
1802 	}
1803 	return ct;
1804 }
1805 
1806 /* "local" means that we should preserve one skb (for local delivery) */
1807 
1808 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
1809 			  struct sk_buff *skb, struct mfc_cache *cache,
1810 			  int local)
1811 {
1812 	int psend = -1;
1813 	int vif, ct;
1814 	int true_vifi = ipmr_find_vif(mrt, skb->dev);
1815 
1816 	vif = cache->mfc_parent;
1817 	cache->mfc_un.res.pkt++;
1818 	cache->mfc_un.res.bytes += skb->len;
1819 
1820 	if (cache->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
1821 		struct mfc_cache *cache_proxy;
1822 
1823 		/* For an (*,G) entry, we only check that the incomming
1824 		 * interface is part of the static tree.
1825 		 */
1826 		cache_proxy = ipmr_cache_find_any_parent(mrt, vif);
1827 		if (cache_proxy &&
1828 		    cache_proxy->mfc_un.res.ttls[true_vifi] < 255)
1829 			goto forward;
1830 	}
1831 
1832 	/*
1833 	 * Wrong interface: drop packet and (maybe) send PIM assert.
1834 	 */
1835 	if (mrt->vif_table[vif].dev != skb->dev) {
1836 		if (rt_is_output_route(skb_rtable(skb))) {
1837 			/* It is our own packet, looped back.
1838 			 * Very complicated situation...
1839 			 *
1840 			 * The best workaround until routing daemons will be
1841 			 * fixed is not to redistribute packet, if it was
1842 			 * send through wrong interface. It means, that
1843 			 * multicast applications WILL NOT work for
1844 			 * (S,G), which have default multicast route pointing
1845 			 * to wrong oif. In any case, it is not a good
1846 			 * idea to use multicasting applications on router.
1847 			 */
1848 			goto dont_forward;
1849 		}
1850 
1851 		cache->mfc_un.res.wrong_if++;
1852 
1853 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
1854 		    /* pimsm uses asserts, when switching from RPT to SPT,
1855 		     * so that we cannot check that packet arrived on an oif.
1856 		     * It is bad, but otherwise we would need to move pretty
1857 		     * large chunk of pimd to kernel. Ough... --ANK
1858 		     */
1859 		    (mrt->mroute_do_pim ||
1860 		     cache->mfc_un.res.ttls[true_vifi] < 255) &&
1861 		    time_after(jiffies,
1862 			       cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1863 			cache->mfc_un.res.last_assert = jiffies;
1864 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1865 		}
1866 		goto dont_forward;
1867 	}
1868 
1869 forward:
1870 	mrt->vif_table[vif].pkt_in++;
1871 	mrt->vif_table[vif].bytes_in += skb->len;
1872 
1873 	/*
1874 	 *	Forward the frame
1875 	 */
1876 	if (cache->mfc_origin == htonl(INADDR_ANY) &&
1877 	    cache->mfc_mcastgrp == htonl(INADDR_ANY)) {
1878 		if (true_vifi >= 0 &&
1879 		    true_vifi != cache->mfc_parent &&
1880 		    ip_hdr(skb)->ttl >
1881 				cache->mfc_un.res.ttls[cache->mfc_parent]) {
1882 			/* It's an (*,*) entry and the packet is not coming from
1883 			 * the upstream: forward the packet to the upstream
1884 			 * only.
1885 			 */
1886 			psend = cache->mfc_parent;
1887 			goto last_forward;
1888 		}
1889 		goto dont_forward;
1890 	}
1891 	for (ct = cache->mfc_un.res.maxvif - 1;
1892 	     ct >= cache->mfc_un.res.minvif; ct--) {
1893 		/* For (*,G) entry, don't forward to the incoming interface */
1894 		if ((cache->mfc_origin != htonl(INADDR_ANY) ||
1895 		     ct != true_vifi) &&
1896 		    ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1897 			if (psend != -1) {
1898 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1899 
1900 				if (skb2)
1901 					ipmr_queue_xmit(net, mrt, skb2, cache,
1902 							psend);
1903 			}
1904 			psend = ct;
1905 		}
1906 	}
1907 last_forward:
1908 	if (psend != -1) {
1909 		if (local) {
1910 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1911 
1912 			if (skb2)
1913 				ipmr_queue_xmit(net, mrt, skb2, cache, psend);
1914 		} else {
1915 			ipmr_queue_xmit(net, mrt, skb, cache, psend);
1916 			return;
1917 		}
1918 	}
1919 
1920 dont_forward:
1921 	if (!local)
1922 		kfree_skb(skb);
1923 }
1924 
1925 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
1926 {
1927 	struct rtable *rt = skb_rtable(skb);
1928 	struct iphdr *iph = ip_hdr(skb);
1929 	struct flowi4 fl4 = {
1930 		.daddr = iph->daddr,
1931 		.saddr = iph->saddr,
1932 		.flowi4_tos = RT_TOS(iph->tos),
1933 		.flowi4_oif = (rt_is_output_route(rt) ?
1934 			       skb->dev->ifindex : 0),
1935 		.flowi4_iif = (rt_is_output_route(rt) ?
1936 			       LOOPBACK_IFINDEX :
1937 			       skb->dev->ifindex),
1938 		.flowi4_mark = skb->mark,
1939 	};
1940 	struct mr_table *mrt;
1941 	int err;
1942 
1943 	err = ipmr_fib_lookup(net, &fl4, &mrt);
1944 	if (err)
1945 		return ERR_PTR(err);
1946 	return mrt;
1947 }
1948 
1949 /*
1950  *	Multicast packets for forwarding arrive here
1951  *	Called with rcu_read_lock();
1952  */
1953 
1954 int ip_mr_input(struct sk_buff *skb)
1955 {
1956 	struct mfc_cache *cache;
1957 	struct net *net = dev_net(skb->dev);
1958 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
1959 	struct mr_table *mrt;
1960 
1961 	/* Packet is looped back after forward, it should not be
1962 	 * forwarded second time, but still can be delivered locally.
1963 	 */
1964 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
1965 		goto dont_forward;
1966 
1967 	mrt = ipmr_rt_fib_lookup(net, skb);
1968 	if (IS_ERR(mrt)) {
1969 		kfree_skb(skb);
1970 		return PTR_ERR(mrt);
1971 	}
1972 	if (!local) {
1973 		if (IPCB(skb)->opt.router_alert) {
1974 			if (ip_call_ra_chain(skb))
1975 				return 0;
1976 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
1977 			/* IGMPv1 (and broken IGMPv2 implementations sort of
1978 			 * Cisco IOS <= 11.2(8)) do not put router alert
1979 			 * option to IGMP packets destined to routable
1980 			 * groups. It is very bad, because it means
1981 			 * that we can forward NO IGMP messages.
1982 			 */
1983 			struct sock *mroute_sk;
1984 
1985 			mroute_sk = rcu_dereference(mrt->mroute_sk);
1986 			if (mroute_sk) {
1987 				nf_reset(skb);
1988 				raw_rcv(mroute_sk, skb);
1989 				return 0;
1990 			}
1991 		    }
1992 	}
1993 
1994 	/* already under rcu_read_lock() */
1995 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
1996 	if (cache == NULL) {
1997 		int vif = ipmr_find_vif(mrt, skb->dev);
1998 
1999 		if (vif >= 0)
2000 			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
2001 						    vif);
2002 	}
2003 
2004 	/*
2005 	 *	No usable cache entry
2006 	 */
2007 	if (cache == NULL) {
2008 		int vif;
2009 
2010 		if (local) {
2011 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2012 			ip_local_deliver(skb);
2013 			if (skb2 == NULL)
2014 				return -ENOBUFS;
2015 			skb = skb2;
2016 		}
2017 
2018 		read_lock(&mrt_lock);
2019 		vif = ipmr_find_vif(mrt, skb->dev);
2020 		if (vif >= 0) {
2021 			int err2 = ipmr_cache_unresolved(mrt, vif, skb);
2022 			read_unlock(&mrt_lock);
2023 
2024 			return err2;
2025 		}
2026 		read_unlock(&mrt_lock);
2027 		kfree_skb(skb);
2028 		return -ENODEV;
2029 	}
2030 
2031 	read_lock(&mrt_lock);
2032 	ip_mr_forward(net, mrt, skb, cache, local);
2033 	read_unlock(&mrt_lock);
2034 
2035 	if (local)
2036 		return ip_local_deliver(skb);
2037 
2038 	return 0;
2039 
2040 dont_forward:
2041 	if (local)
2042 		return ip_local_deliver(skb);
2043 	kfree_skb(skb);
2044 	return 0;
2045 }
2046 
2047 #ifdef CONFIG_IP_PIMSM
2048 /* called with rcu_read_lock() */
2049 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
2050 		     unsigned int pimlen)
2051 {
2052 	struct net_device *reg_dev = NULL;
2053 	struct iphdr *encap;
2054 
2055 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
2056 	/*
2057 	 * Check that:
2058 	 * a. packet is really sent to a multicast group
2059 	 * b. packet is not a NULL-REGISTER
2060 	 * c. packet is not truncated
2061 	 */
2062 	if (!ipv4_is_multicast(encap->daddr) ||
2063 	    encap->tot_len == 0 ||
2064 	    ntohs(encap->tot_len) + pimlen > skb->len)
2065 		return 1;
2066 
2067 	read_lock(&mrt_lock);
2068 	if (mrt->mroute_reg_vif_num >= 0)
2069 		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
2070 	read_unlock(&mrt_lock);
2071 
2072 	if (reg_dev == NULL)
2073 		return 1;
2074 
2075 	skb->mac_header = skb->network_header;
2076 	skb_pull(skb, (u8 *)encap - skb->data);
2077 	skb_reset_network_header(skb);
2078 	skb->protocol = htons(ETH_P_IP);
2079 	skb->ip_summed = CHECKSUM_NONE;
2080 
2081 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
2082 
2083 	netif_rx(skb);
2084 
2085 	return NET_RX_SUCCESS;
2086 }
2087 #endif
2088 
2089 #ifdef CONFIG_IP_PIMSM_V1
2090 /*
2091  * Handle IGMP messages of PIMv1
2092  */
2093 
2094 int pim_rcv_v1(struct sk_buff *skb)
2095 {
2096 	struct igmphdr *pim;
2097 	struct net *net = dev_net(skb->dev);
2098 	struct mr_table *mrt;
2099 
2100 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2101 		goto drop;
2102 
2103 	pim = igmp_hdr(skb);
2104 
2105 	mrt = ipmr_rt_fib_lookup(net, skb);
2106 	if (IS_ERR(mrt))
2107 		goto drop;
2108 	if (!mrt->mroute_do_pim ||
2109 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2110 		goto drop;
2111 
2112 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2113 drop:
2114 		kfree_skb(skb);
2115 	}
2116 	return 0;
2117 }
2118 #endif
2119 
2120 #ifdef CONFIG_IP_PIMSM_V2
2121 static int pim_rcv(struct sk_buff *skb)
2122 {
2123 	struct pimreghdr *pim;
2124 	struct net *net = dev_net(skb->dev);
2125 	struct mr_table *mrt;
2126 
2127 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2128 		goto drop;
2129 
2130 	pim = (struct pimreghdr *)skb_transport_header(skb);
2131 	if (pim->type != ((PIM_VERSION << 4) | (PIM_REGISTER)) ||
2132 	    (pim->flags & PIM_NULL_REGISTER) ||
2133 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2134 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2135 		goto drop;
2136 
2137 	mrt = ipmr_rt_fib_lookup(net, skb);
2138 	if (IS_ERR(mrt))
2139 		goto drop;
2140 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2141 drop:
2142 		kfree_skb(skb);
2143 	}
2144 	return 0;
2145 }
2146 #endif
2147 
2148 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2149 			      struct mfc_cache *c, struct rtmsg *rtm)
2150 {
2151 	int ct;
2152 	struct rtnexthop *nhp;
2153 	struct nlattr *mp_attr;
2154 	struct rta_mfc_stats mfcs;
2155 
2156 	/* If cache is unresolved, don't try to parse IIF and OIF */
2157 	if (c->mfc_parent >= MAXVIFS)
2158 		return -ENOENT;
2159 
2160 	if (VIF_EXISTS(mrt, c->mfc_parent) &&
2161 	    nla_put_u32(skb, RTA_IIF, mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
2162 		return -EMSGSIZE;
2163 
2164 	if (!(mp_attr = nla_nest_start(skb, RTA_MULTIPATH)))
2165 		return -EMSGSIZE;
2166 
2167 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
2168 		if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
2169 			if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp)))) {
2170 				nla_nest_cancel(skb, mp_attr);
2171 				return -EMSGSIZE;
2172 			}
2173 
2174 			nhp->rtnh_flags = 0;
2175 			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
2176 			nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
2177 			nhp->rtnh_len = sizeof(*nhp);
2178 		}
2179 	}
2180 
2181 	nla_nest_end(skb, mp_attr);
2182 
2183 	mfcs.mfcs_packets = c->mfc_un.res.pkt;
2184 	mfcs.mfcs_bytes = c->mfc_un.res.bytes;
2185 	mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
2186 	if (nla_put(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs) < 0)
2187 		return -EMSGSIZE;
2188 
2189 	rtm->rtm_type = RTN_MULTICAST;
2190 	return 1;
2191 }
2192 
2193 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2194 		   __be32 saddr, __be32 daddr,
2195 		   struct rtmsg *rtm, int nowait)
2196 {
2197 	struct mfc_cache *cache;
2198 	struct mr_table *mrt;
2199 	int err;
2200 
2201 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2202 	if (mrt == NULL)
2203 		return -ENOENT;
2204 
2205 	rcu_read_lock();
2206 	cache = ipmr_cache_find(mrt, saddr, daddr);
2207 	if (cache == NULL && skb->dev) {
2208 		int vif = ipmr_find_vif(mrt, skb->dev);
2209 
2210 		if (vif >= 0)
2211 			cache = ipmr_cache_find_any(mrt, daddr, vif);
2212 	}
2213 	if (cache == NULL) {
2214 		struct sk_buff *skb2;
2215 		struct iphdr *iph;
2216 		struct net_device *dev;
2217 		int vif = -1;
2218 
2219 		if (nowait) {
2220 			rcu_read_unlock();
2221 			return -EAGAIN;
2222 		}
2223 
2224 		dev = skb->dev;
2225 		read_lock(&mrt_lock);
2226 		if (dev)
2227 			vif = ipmr_find_vif(mrt, dev);
2228 		if (vif < 0) {
2229 			read_unlock(&mrt_lock);
2230 			rcu_read_unlock();
2231 			return -ENODEV;
2232 		}
2233 		skb2 = skb_clone(skb, GFP_ATOMIC);
2234 		if (!skb2) {
2235 			read_unlock(&mrt_lock);
2236 			rcu_read_unlock();
2237 			return -ENOMEM;
2238 		}
2239 
2240 		skb_push(skb2, sizeof(struct iphdr));
2241 		skb_reset_network_header(skb2);
2242 		iph = ip_hdr(skb2);
2243 		iph->ihl = sizeof(struct iphdr) >> 2;
2244 		iph->saddr = saddr;
2245 		iph->daddr = daddr;
2246 		iph->version = 0;
2247 		err = ipmr_cache_unresolved(mrt, vif, skb2);
2248 		read_unlock(&mrt_lock);
2249 		rcu_read_unlock();
2250 		return err;
2251 	}
2252 
2253 	read_lock(&mrt_lock);
2254 	if (!nowait && (rtm->rtm_flags & RTM_F_NOTIFY))
2255 		cache->mfc_flags |= MFC_NOTIFY;
2256 	err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2257 	read_unlock(&mrt_lock);
2258 	rcu_read_unlock();
2259 	return err;
2260 }
2261 
2262 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2263 			    u32 portid, u32 seq, struct mfc_cache *c, int cmd,
2264 			    int flags)
2265 {
2266 	struct nlmsghdr *nlh;
2267 	struct rtmsg *rtm;
2268 	int err;
2269 
2270 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2271 	if (nlh == NULL)
2272 		return -EMSGSIZE;
2273 
2274 	rtm = nlmsg_data(nlh);
2275 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2276 	rtm->rtm_dst_len  = 32;
2277 	rtm->rtm_src_len  = 32;
2278 	rtm->rtm_tos      = 0;
2279 	rtm->rtm_table    = mrt->id;
2280 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2281 		goto nla_put_failure;
2282 	rtm->rtm_type     = RTN_MULTICAST;
2283 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2284 	if (c->mfc_flags & MFC_STATIC)
2285 		rtm->rtm_protocol = RTPROT_STATIC;
2286 	else
2287 		rtm->rtm_protocol = RTPROT_MROUTED;
2288 	rtm->rtm_flags    = 0;
2289 
2290 	if (nla_put_be32(skb, RTA_SRC, c->mfc_origin) ||
2291 	    nla_put_be32(skb, RTA_DST, c->mfc_mcastgrp))
2292 		goto nla_put_failure;
2293 	err = __ipmr_fill_mroute(mrt, skb, c, rtm);
2294 	/* do not break the dump if cache is unresolved */
2295 	if (err < 0 && err != -ENOENT)
2296 		goto nla_put_failure;
2297 
2298 	nlmsg_end(skb, nlh);
2299 	return 0;
2300 
2301 nla_put_failure:
2302 	nlmsg_cancel(skb, nlh);
2303 	return -EMSGSIZE;
2304 }
2305 
2306 static size_t mroute_msgsize(bool unresolved, int maxvif)
2307 {
2308 	size_t len =
2309 		NLMSG_ALIGN(sizeof(struct rtmsg))
2310 		+ nla_total_size(4)	/* RTA_TABLE */
2311 		+ nla_total_size(4)	/* RTA_SRC */
2312 		+ nla_total_size(4)	/* RTA_DST */
2313 		;
2314 
2315 	if (!unresolved)
2316 		len = len
2317 		      + nla_total_size(4)	/* RTA_IIF */
2318 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2319 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2320 						/* RTA_MFC_STATS */
2321 		      + nla_total_size(sizeof(struct rta_mfc_stats))
2322 		;
2323 
2324 	return len;
2325 }
2326 
2327 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2328 				 int cmd)
2329 {
2330 	struct net *net = read_pnet(&mrt->net);
2331 	struct sk_buff *skb;
2332 	int err = -ENOBUFS;
2333 
2334 	skb = nlmsg_new(mroute_msgsize(mfc->mfc_parent >= MAXVIFS, mrt->maxvif),
2335 			GFP_ATOMIC);
2336 	if (skb == NULL)
2337 		goto errout;
2338 
2339 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2340 	if (err < 0)
2341 		goto errout;
2342 
2343 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2344 	return;
2345 
2346 errout:
2347 	kfree_skb(skb);
2348 	if (err < 0)
2349 		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2350 }
2351 
2352 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2353 {
2354 	struct net *net = sock_net(skb->sk);
2355 	struct mr_table *mrt;
2356 	struct mfc_cache *mfc;
2357 	unsigned int t = 0, s_t;
2358 	unsigned int h = 0, s_h;
2359 	unsigned int e = 0, s_e;
2360 
2361 	s_t = cb->args[0];
2362 	s_h = cb->args[1];
2363 	s_e = cb->args[2];
2364 
2365 	rcu_read_lock();
2366 	ipmr_for_each_table(mrt, net) {
2367 		if (t < s_t)
2368 			goto next_table;
2369 		if (t > s_t)
2370 			s_h = 0;
2371 		for (h = s_h; h < MFC_LINES; h++) {
2372 			list_for_each_entry_rcu(mfc, &mrt->mfc_cache_array[h], list) {
2373 				if (e < s_e)
2374 					goto next_entry;
2375 				if (ipmr_fill_mroute(mrt, skb,
2376 						     NETLINK_CB(cb->skb).portid,
2377 						     cb->nlh->nlmsg_seq,
2378 						     mfc, RTM_NEWROUTE,
2379 						     NLM_F_MULTI) < 0)
2380 					goto done;
2381 next_entry:
2382 				e++;
2383 			}
2384 			e = s_e = 0;
2385 		}
2386 		spin_lock_bh(&mfc_unres_lock);
2387 		list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
2388 			if (e < s_e)
2389 				goto next_entry2;
2390 			if (ipmr_fill_mroute(mrt, skb,
2391 					     NETLINK_CB(cb->skb).portid,
2392 					     cb->nlh->nlmsg_seq,
2393 					     mfc, RTM_NEWROUTE,
2394 					     NLM_F_MULTI) < 0) {
2395 				spin_unlock_bh(&mfc_unres_lock);
2396 				goto done;
2397 			}
2398 next_entry2:
2399 			e++;
2400 		}
2401 		spin_unlock_bh(&mfc_unres_lock);
2402 		e = s_e = 0;
2403 		s_h = 0;
2404 next_table:
2405 		t++;
2406 	}
2407 done:
2408 	rcu_read_unlock();
2409 
2410 	cb->args[2] = e;
2411 	cb->args[1] = h;
2412 	cb->args[0] = t;
2413 
2414 	return skb->len;
2415 }
2416 
2417 #ifdef CONFIG_PROC_FS
2418 /*
2419  *	The /proc interfaces to multicast routing :
2420  *	/proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2421  */
2422 struct ipmr_vif_iter {
2423 	struct seq_net_private p;
2424 	struct mr_table *mrt;
2425 	int ct;
2426 };
2427 
2428 static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2429 					   struct ipmr_vif_iter *iter,
2430 					   loff_t pos)
2431 {
2432 	struct mr_table *mrt = iter->mrt;
2433 
2434 	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2435 		if (!VIF_EXISTS(mrt, iter->ct))
2436 			continue;
2437 		if (pos-- == 0)
2438 			return &mrt->vif_table[iter->ct];
2439 	}
2440 	return NULL;
2441 }
2442 
2443 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2444 	__acquires(mrt_lock)
2445 {
2446 	struct ipmr_vif_iter *iter = seq->private;
2447 	struct net *net = seq_file_net(seq);
2448 	struct mr_table *mrt;
2449 
2450 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2451 	if (mrt == NULL)
2452 		return ERR_PTR(-ENOENT);
2453 
2454 	iter->mrt = mrt;
2455 
2456 	read_lock(&mrt_lock);
2457 	return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2458 		: SEQ_START_TOKEN;
2459 }
2460 
2461 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2462 {
2463 	struct ipmr_vif_iter *iter = seq->private;
2464 	struct net *net = seq_file_net(seq);
2465 	struct mr_table *mrt = iter->mrt;
2466 
2467 	++*pos;
2468 	if (v == SEQ_START_TOKEN)
2469 		return ipmr_vif_seq_idx(net, iter, 0);
2470 
2471 	while (++iter->ct < mrt->maxvif) {
2472 		if (!VIF_EXISTS(mrt, iter->ct))
2473 			continue;
2474 		return &mrt->vif_table[iter->ct];
2475 	}
2476 	return NULL;
2477 }
2478 
2479 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2480 	__releases(mrt_lock)
2481 {
2482 	read_unlock(&mrt_lock);
2483 }
2484 
2485 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2486 {
2487 	struct ipmr_vif_iter *iter = seq->private;
2488 	struct mr_table *mrt = iter->mrt;
2489 
2490 	if (v == SEQ_START_TOKEN) {
2491 		seq_puts(seq,
2492 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2493 	} else {
2494 		const struct vif_device *vif = v;
2495 		const char *name =  vif->dev ? vif->dev->name : "none";
2496 
2497 		seq_printf(seq,
2498 			   "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2499 			   vif - mrt->vif_table,
2500 			   name, vif->bytes_in, vif->pkt_in,
2501 			   vif->bytes_out, vif->pkt_out,
2502 			   vif->flags, vif->local, vif->remote);
2503 	}
2504 	return 0;
2505 }
2506 
2507 static const struct seq_operations ipmr_vif_seq_ops = {
2508 	.start = ipmr_vif_seq_start,
2509 	.next  = ipmr_vif_seq_next,
2510 	.stop  = ipmr_vif_seq_stop,
2511 	.show  = ipmr_vif_seq_show,
2512 };
2513 
2514 static int ipmr_vif_open(struct inode *inode, struct file *file)
2515 {
2516 	return seq_open_net(inode, file, &ipmr_vif_seq_ops,
2517 			    sizeof(struct ipmr_vif_iter));
2518 }
2519 
2520 static const struct file_operations ipmr_vif_fops = {
2521 	.owner	 = THIS_MODULE,
2522 	.open    = ipmr_vif_open,
2523 	.read    = seq_read,
2524 	.llseek  = seq_lseek,
2525 	.release = seq_release_net,
2526 };
2527 
2528 struct ipmr_mfc_iter {
2529 	struct seq_net_private p;
2530 	struct mr_table *mrt;
2531 	struct list_head *cache;
2532 	int ct;
2533 };
2534 
2535 
2536 static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
2537 					  struct ipmr_mfc_iter *it, loff_t pos)
2538 {
2539 	struct mr_table *mrt = it->mrt;
2540 	struct mfc_cache *mfc;
2541 
2542 	rcu_read_lock();
2543 	for (it->ct = 0; it->ct < MFC_LINES; it->ct++) {
2544 		it->cache = &mrt->mfc_cache_array[it->ct];
2545 		list_for_each_entry_rcu(mfc, it->cache, list)
2546 			if (pos-- == 0)
2547 				return mfc;
2548 	}
2549 	rcu_read_unlock();
2550 
2551 	spin_lock_bh(&mfc_unres_lock);
2552 	it->cache = &mrt->mfc_unres_queue;
2553 	list_for_each_entry(mfc, it->cache, list)
2554 		if (pos-- == 0)
2555 			return mfc;
2556 	spin_unlock_bh(&mfc_unres_lock);
2557 
2558 	it->cache = NULL;
2559 	return NULL;
2560 }
2561 
2562 
2563 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2564 {
2565 	struct ipmr_mfc_iter *it = seq->private;
2566 	struct net *net = seq_file_net(seq);
2567 	struct mr_table *mrt;
2568 
2569 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2570 	if (mrt == NULL)
2571 		return ERR_PTR(-ENOENT);
2572 
2573 	it->mrt = mrt;
2574 	it->cache = NULL;
2575 	it->ct = 0;
2576 	return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
2577 		: SEQ_START_TOKEN;
2578 }
2579 
2580 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2581 {
2582 	struct mfc_cache *mfc = v;
2583 	struct ipmr_mfc_iter *it = seq->private;
2584 	struct net *net = seq_file_net(seq);
2585 	struct mr_table *mrt = it->mrt;
2586 
2587 	++*pos;
2588 
2589 	if (v == SEQ_START_TOKEN)
2590 		return ipmr_mfc_seq_idx(net, seq->private, 0);
2591 
2592 	if (mfc->list.next != it->cache)
2593 		return list_entry(mfc->list.next, struct mfc_cache, list);
2594 
2595 	if (it->cache == &mrt->mfc_unres_queue)
2596 		goto end_of_list;
2597 
2598 	BUG_ON(it->cache != &mrt->mfc_cache_array[it->ct]);
2599 
2600 	while (++it->ct < MFC_LINES) {
2601 		it->cache = &mrt->mfc_cache_array[it->ct];
2602 		if (list_empty(it->cache))
2603 			continue;
2604 		return list_first_entry(it->cache, struct mfc_cache, list);
2605 	}
2606 
2607 	/* exhausted cache_array, show unresolved */
2608 	rcu_read_unlock();
2609 	it->cache = &mrt->mfc_unres_queue;
2610 	it->ct = 0;
2611 
2612 	spin_lock_bh(&mfc_unres_lock);
2613 	if (!list_empty(it->cache))
2614 		return list_first_entry(it->cache, struct mfc_cache, list);
2615 
2616 end_of_list:
2617 	spin_unlock_bh(&mfc_unres_lock);
2618 	it->cache = NULL;
2619 
2620 	return NULL;
2621 }
2622 
2623 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
2624 {
2625 	struct ipmr_mfc_iter *it = seq->private;
2626 	struct mr_table *mrt = it->mrt;
2627 
2628 	if (it->cache == &mrt->mfc_unres_queue)
2629 		spin_unlock_bh(&mfc_unres_lock);
2630 	else if (it->cache == &mrt->mfc_cache_array[it->ct])
2631 		rcu_read_unlock();
2632 }
2633 
2634 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2635 {
2636 	int n;
2637 
2638 	if (v == SEQ_START_TOKEN) {
2639 		seq_puts(seq,
2640 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2641 	} else {
2642 		const struct mfc_cache *mfc = v;
2643 		const struct ipmr_mfc_iter *it = seq->private;
2644 		const struct mr_table *mrt = it->mrt;
2645 
2646 		seq_printf(seq, "%08X %08X %-3hd",
2647 			   (__force u32) mfc->mfc_mcastgrp,
2648 			   (__force u32) mfc->mfc_origin,
2649 			   mfc->mfc_parent);
2650 
2651 		if (it->cache != &mrt->mfc_unres_queue) {
2652 			seq_printf(seq, " %8lu %8lu %8lu",
2653 				   mfc->mfc_un.res.pkt,
2654 				   mfc->mfc_un.res.bytes,
2655 				   mfc->mfc_un.res.wrong_if);
2656 			for (n = mfc->mfc_un.res.minvif;
2657 			     n < mfc->mfc_un.res.maxvif; n++) {
2658 				if (VIF_EXISTS(mrt, n) &&
2659 				    mfc->mfc_un.res.ttls[n] < 255)
2660 					seq_printf(seq,
2661 					   " %2d:%-3d",
2662 					   n, mfc->mfc_un.res.ttls[n]);
2663 			}
2664 		} else {
2665 			/* unresolved mfc_caches don't contain
2666 			 * pkt, bytes and wrong_if values
2667 			 */
2668 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
2669 		}
2670 		seq_putc(seq, '\n');
2671 	}
2672 	return 0;
2673 }
2674 
2675 static const struct seq_operations ipmr_mfc_seq_ops = {
2676 	.start = ipmr_mfc_seq_start,
2677 	.next  = ipmr_mfc_seq_next,
2678 	.stop  = ipmr_mfc_seq_stop,
2679 	.show  = ipmr_mfc_seq_show,
2680 };
2681 
2682 static int ipmr_mfc_open(struct inode *inode, struct file *file)
2683 {
2684 	return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
2685 			    sizeof(struct ipmr_mfc_iter));
2686 }
2687 
2688 static const struct file_operations ipmr_mfc_fops = {
2689 	.owner	 = THIS_MODULE,
2690 	.open    = ipmr_mfc_open,
2691 	.read    = seq_read,
2692 	.llseek  = seq_lseek,
2693 	.release = seq_release_net,
2694 };
2695 #endif
2696 
2697 #ifdef CONFIG_IP_PIMSM_V2
2698 static const struct net_protocol pim_protocol = {
2699 	.handler	=	pim_rcv,
2700 	.netns_ok	=	1,
2701 };
2702 #endif
2703 
2704 
2705 /*
2706  *	Setup for IP multicast routing
2707  */
2708 static int __net_init ipmr_net_init(struct net *net)
2709 {
2710 	int err;
2711 
2712 	err = ipmr_rules_init(net);
2713 	if (err < 0)
2714 		goto fail;
2715 
2716 #ifdef CONFIG_PROC_FS
2717 	err = -ENOMEM;
2718 	if (!proc_create("ip_mr_vif", 0, net->proc_net, &ipmr_vif_fops))
2719 		goto proc_vif_fail;
2720 	if (!proc_create("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_fops))
2721 		goto proc_cache_fail;
2722 #endif
2723 	return 0;
2724 
2725 #ifdef CONFIG_PROC_FS
2726 proc_cache_fail:
2727 	remove_proc_entry("ip_mr_vif", net->proc_net);
2728 proc_vif_fail:
2729 	ipmr_rules_exit(net);
2730 #endif
2731 fail:
2732 	return err;
2733 }
2734 
2735 static void __net_exit ipmr_net_exit(struct net *net)
2736 {
2737 #ifdef CONFIG_PROC_FS
2738 	remove_proc_entry("ip_mr_cache", net->proc_net);
2739 	remove_proc_entry("ip_mr_vif", net->proc_net);
2740 #endif
2741 	ipmr_rules_exit(net);
2742 }
2743 
2744 static struct pernet_operations ipmr_net_ops = {
2745 	.init = ipmr_net_init,
2746 	.exit = ipmr_net_exit,
2747 };
2748 
2749 int __init ip_mr_init(void)
2750 {
2751 	int err;
2752 
2753 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
2754 				       sizeof(struct mfc_cache),
2755 				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
2756 				       NULL);
2757 	if (!mrt_cachep)
2758 		return -ENOMEM;
2759 
2760 	err = register_pernet_subsys(&ipmr_net_ops);
2761 	if (err)
2762 		goto reg_pernet_fail;
2763 
2764 	err = register_netdevice_notifier(&ip_mr_notifier);
2765 	if (err)
2766 		goto reg_notif_fail;
2767 #ifdef CONFIG_IP_PIMSM_V2
2768 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
2769 		pr_err("%s: can't add PIM protocol\n", __func__);
2770 		err = -EAGAIN;
2771 		goto add_proto_fail;
2772 	}
2773 #endif
2774 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
2775 		      NULL, ipmr_rtm_dumproute, NULL);
2776 	return 0;
2777 
2778 #ifdef CONFIG_IP_PIMSM_V2
2779 add_proto_fail:
2780 	unregister_netdevice_notifier(&ip_mr_notifier);
2781 #endif
2782 reg_notif_fail:
2783 	unregister_pernet_subsys(&ipmr_net_ops);
2784 reg_pernet_fail:
2785 	kmem_cache_destroy(mrt_cachep);
2786 	return err;
2787 }
2788