xref: /openbmc/linux/net/ipv4/ipmr.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
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 <linux/compat.h>
64 #include <net/ipip.h>
65 #include <net/checksum.h>
66 #include <net/netlink.h>
67 #include <net/fib_rules.h>
68 
69 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
70 #define CONFIG_IP_PIMSM	1
71 #endif
72 
73 struct mr_table {
74 	struct list_head	list;
75 #ifdef CONFIG_NET_NS
76 	struct net		*net;
77 #endif
78 	u32			id;
79 	struct sock __rcu	*mroute_sk;
80 	struct timer_list	ipmr_expire_timer;
81 	struct list_head	mfc_unres_queue;
82 	struct list_head	mfc_cache_array[MFC_LINES];
83 	struct vif_device	vif_table[MAXVIFS];
84 	int			maxvif;
85 	atomic_t		cache_resolve_queue_len;
86 	int			mroute_do_assert;
87 	int			mroute_do_pim;
88 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
89 	int			mroute_reg_vif_num;
90 #endif
91 };
92 
93 struct ipmr_rule {
94 	struct fib_rule		common;
95 };
96 
97 struct ipmr_result {
98 	struct mr_table		*mrt;
99 };
100 
101 /* Big lock, protecting vif table, mrt cache and mroute socket state.
102  * Note that the changes are semaphored via rtnl_lock.
103  */
104 
105 static DEFINE_RWLOCK(mrt_lock);
106 
107 /*
108  *	Multicast router control variables
109  */
110 
111 #define VIF_EXISTS(_mrt, _idx) ((_mrt)->vif_table[_idx].dev != NULL)
112 
113 /* Special spinlock for queue of unresolved entries */
114 static DEFINE_SPINLOCK(mfc_unres_lock);
115 
116 /* We return to original Alan's scheme. Hash table of resolved
117  * entries is changed only in process context and protected
118  * with weak lock mrt_lock. Queue of unresolved entries is protected
119  * with strong spinlock mfc_unres_lock.
120  *
121  * In this case data path is free of exclusive locks at all.
122  */
123 
124 static struct kmem_cache *mrt_cachep __read_mostly;
125 
126 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
127 static int ip_mr_forward(struct net *net, struct mr_table *mrt,
128 			 struct sk_buff *skb, struct mfc_cache *cache,
129 			 int local);
130 static int ipmr_cache_report(struct mr_table *mrt,
131 			     struct sk_buff *pkt, vifi_t vifi, int assert);
132 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
133 			      struct mfc_cache *c, struct rtmsg *rtm);
134 static void ipmr_expire_process(unsigned long arg);
135 
136 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
137 #define ipmr_for_each_table(mrt, net) \
138 	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
139 
140 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
141 {
142 	struct mr_table *mrt;
143 
144 	ipmr_for_each_table(mrt, net) {
145 		if (mrt->id == id)
146 			return mrt;
147 	}
148 	return NULL;
149 }
150 
151 static int ipmr_fib_lookup(struct net *net, struct flowi *flp,
152 			   struct mr_table **mrt)
153 {
154 	struct ipmr_result res;
155 	struct fib_lookup_arg arg = { .result = &res, };
156 	int err;
157 
158 	err = fib_rules_lookup(net->ipv4.mr_rules_ops, flp, 0, &arg);
159 	if (err < 0)
160 		return err;
161 	*mrt = res.mrt;
162 	return 0;
163 }
164 
165 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
166 			    int flags, struct fib_lookup_arg *arg)
167 {
168 	struct ipmr_result *res = arg->result;
169 	struct mr_table *mrt;
170 
171 	switch (rule->action) {
172 	case FR_ACT_TO_TBL:
173 		break;
174 	case FR_ACT_UNREACHABLE:
175 		return -ENETUNREACH;
176 	case FR_ACT_PROHIBIT:
177 		return -EACCES;
178 	case FR_ACT_BLACKHOLE:
179 	default:
180 		return -EINVAL;
181 	}
182 
183 	mrt = ipmr_get_table(rule->fr_net, rule->table);
184 	if (mrt == NULL)
185 		return -EAGAIN;
186 	res->mrt = mrt;
187 	return 0;
188 }
189 
190 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
191 {
192 	return 1;
193 }
194 
195 static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
196 	FRA_GENERIC_POLICY,
197 };
198 
199 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
200 			       struct fib_rule_hdr *frh, struct nlattr **tb)
201 {
202 	return 0;
203 }
204 
205 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
206 			     struct nlattr **tb)
207 {
208 	return 1;
209 }
210 
211 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
212 			  struct fib_rule_hdr *frh)
213 {
214 	frh->dst_len = 0;
215 	frh->src_len = 0;
216 	frh->tos     = 0;
217 	return 0;
218 }
219 
220 static const struct fib_rules_ops __net_initdata ipmr_rules_ops_template = {
221 	.family		= RTNL_FAMILY_IPMR,
222 	.rule_size	= sizeof(struct ipmr_rule),
223 	.addr_size	= sizeof(u32),
224 	.action		= ipmr_rule_action,
225 	.match		= ipmr_rule_match,
226 	.configure	= ipmr_rule_configure,
227 	.compare	= ipmr_rule_compare,
228 	.default_pref	= fib_default_rule_pref,
229 	.fill		= ipmr_rule_fill,
230 	.nlgroup	= RTNLGRP_IPV4_RULE,
231 	.policy		= ipmr_rule_policy,
232 	.owner		= THIS_MODULE,
233 };
234 
235 static int __net_init ipmr_rules_init(struct net *net)
236 {
237 	struct fib_rules_ops *ops;
238 	struct mr_table *mrt;
239 	int err;
240 
241 	ops = fib_rules_register(&ipmr_rules_ops_template, net);
242 	if (IS_ERR(ops))
243 		return PTR_ERR(ops);
244 
245 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
246 
247 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
248 	if (mrt == NULL) {
249 		err = -ENOMEM;
250 		goto err1;
251 	}
252 
253 	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
254 	if (err < 0)
255 		goto err2;
256 
257 	net->ipv4.mr_rules_ops = ops;
258 	return 0;
259 
260 err2:
261 	kfree(mrt);
262 err1:
263 	fib_rules_unregister(ops);
264 	return err;
265 }
266 
267 static void __net_exit ipmr_rules_exit(struct net *net)
268 {
269 	struct mr_table *mrt, *next;
270 
271 	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
272 		list_del(&mrt->list);
273 		kfree(mrt);
274 	}
275 	fib_rules_unregister(net->ipv4.mr_rules_ops);
276 }
277 #else
278 #define ipmr_for_each_table(mrt, net) \
279 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
280 
281 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
282 {
283 	return net->ipv4.mrt;
284 }
285 
286 static int ipmr_fib_lookup(struct net *net, struct flowi *flp,
287 			   struct mr_table **mrt)
288 {
289 	*mrt = net->ipv4.mrt;
290 	return 0;
291 }
292 
293 static int __net_init ipmr_rules_init(struct net *net)
294 {
295 	net->ipv4.mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
296 	return net->ipv4.mrt ? 0 : -ENOMEM;
297 }
298 
299 static void __net_exit ipmr_rules_exit(struct net *net)
300 {
301 	kfree(net->ipv4.mrt);
302 }
303 #endif
304 
305 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
306 {
307 	struct mr_table *mrt;
308 	unsigned int i;
309 
310 	mrt = ipmr_get_table(net, id);
311 	if (mrt != NULL)
312 		return mrt;
313 
314 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
315 	if (mrt == NULL)
316 		return NULL;
317 	write_pnet(&mrt->net, net);
318 	mrt->id = id;
319 
320 	/* Forwarding cache */
321 	for (i = 0; i < MFC_LINES; i++)
322 		INIT_LIST_HEAD(&mrt->mfc_cache_array[i]);
323 
324 	INIT_LIST_HEAD(&mrt->mfc_unres_queue);
325 
326 	setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
327 		    (unsigned long)mrt);
328 
329 #ifdef CONFIG_IP_PIMSM
330 	mrt->mroute_reg_vif_num = -1;
331 #endif
332 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
333 	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
334 #endif
335 	return mrt;
336 }
337 
338 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
339 
340 static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
341 {
342 	struct net *net = dev_net(dev);
343 
344 	dev_close(dev);
345 
346 	dev = __dev_get_by_name(net, "tunl0");
347 	if (dev) {
348 		const struct net_device_ops *ops = dev->netdev_ops;
349 		struct ifreq ifr;
350 		struct ip_tunnel_parm p;
351 
352 		memset(&p, 0, sizeof(p));
353 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
354 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
355 		p.iph.version = 4;
356 		p.iph.ihl = 5;
357 		p.iph.protocol = IPPROTO_IPIP;
358 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
359 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
360 
361 		if (ops->ndo_do_ioctl) {
362 			mm_segment_t oldfs = get_fs();
363 
364 			set_fs(KERNEL_DS);
365 			ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
366 			set_fs(oldfs);
367 		}
368 	}
369 }
370 
371 static
372 struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
373 {
374 	struct net_device  *dev;
375 
376 	dev = __dev_get_by_name(net, "tunl0");
377 
378 	if (dev) {
379 		const struct net_device_ops *ops = dev->netdev_ops;
380 		int err;
381 		struct ifreq ifr;
382 		struct ip_tunnel_parm p;
383 		struct in_device  *in_dev;
384 
385 		memset(&p, 0, sizeof(p));
386 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
387 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
388 		p.iph.version = 4;
389 		p.iph.ihl = 5;
390 		p.iph.protocol = IPPROTO_IPIP;
391 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
392 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
393 
394 		if (ops->ndo_do_ioctl) {
395 			mm_segment_t oldfs = get_fs();
396 
397 			set_fs(KERNEL_DS);
398 			err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
399 			set_fs(oldfs);
400 		} else {
401 			err = -EOPNOTSUPP;
402 		}
403 		dev = NULL;
404 
405 		if (err == 0 &&
406 		    (dev = __dev_get_by_name(net, p.name)) != NULL) {
407 			dev->flags |= IFF_MULTICAST;
408 
409 			in_dev = __in_dev_get_rtnl(dev);
410 			if (in_dev == NULL)
411 				goto failure;
412 
413 			ipv4_devconf_setall(in_dev);
414 			IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
415 
416 			if (dev_open(dev))
417 				goto failure;
418 			dev_hold(dev);
419 		}
420 	}
421 	return dev;
422 
423 failure:
424 	/* allow the register to be completed before unregistering. */
425 	rtnl_unlock();
426 	rtnl_lock();
427 
428 	unregister_netdevice(dev);
429 	return NULL;
430 }
431 
432 #ifdef CONFIG_IP_PIMSM
433 
434 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
435 {
436 	struct net *net = dev_net(dev);
437 	struct mr_table *mrt;
438 	struct flowi fl = {
439 		.oif		= dev->ifindex,
440 		.iif		= skb->skb_iif,
441 		.mark		= skb->mark,
442 	};
443 	int err;
444 
445 	err = ipmr_fib_lookup(net, &fl, &mrt);
446 	if (err < 0) {
447 		kfree_skb(skb);
448 		return err;
449 	}
450 
451 	read_lock(&mrt_lock);
452 	dev->stats.tx_bytes += skb->len;
453 	dev->stats.tx_packets++;
454 	ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
455 	read_unlock(&mrt_lock);
456 	kfree_skb(skb);
457 	return NETDEV_TX_OK;
458 }
459 
460 static const struct net_device_ops reg_vif_netdev_ops = {
461 	.ndo_start_xmit	= reg_vif_xmit,
462 };
463 
464 static void reg_vif_setup(struct net_device *dev)
465 {
466 	dev->type		= ARPHRD_PIMREG;
467 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
468 	dev->flags		= IFF_NOARP;
469 	dev->netdev_ops		= &reg_vif_netdev_ops,
470 	dev->destructor		= free_netdev;
471 	dev->features		|= NETIF_F_NETNS_LOCAL;
472 }
473 
474 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
475 {
476 	struct net_device *dev;
477 	struct in_device *in_dev;
478 	char name[IFNAMSIZ];
479 
480 	if (mrt->id == RT_TABLE_DEFAULT)
481 		sprintf(name, "pimreg");
482 	else
483 		sprintf(name, "pimreg%u", mrt->id);
484 
485 	dev = alloc_netdev(0, name, reg_vif_setup);
486 
487 	if (dev == NULL)
488 		return NULL;
489 
490 	dev_net_set(dev, net);
491 
492 	if (register_netdevice(dev)) {
493 		free_netdev(dev);
494 		return NULL;
495 	}
496 	dev->iflink = 0;
497 
498 	rcu_read_lock();
499 	in_dev = __in_dev_get_rcu(dev);
500 	if (!in_dev) {
501 		rcu_read_unlock();
502 		goto failure;
503 	}
504 
505 	ipv4_devconf_setall(in_dev);
506 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
507 	rcu_read_unlock();
508 
509 	if (dev_open(dev))
510 		goto failure;
511 
512 	dev_hold(dev);
513 
514 	return dev;
515 
516 failure:
517 	/* allow the register to be completed before unregistering. */
518 	rtnl_unlock();
519 	rtnl_lock();
520 
521 	unregister_netdevice(dev);
522 	return NULL;
523 }
524 #endif
525 
526 /*
527  *	Delete a VIF entry
528  *	@notify: Set to 1, if the caller is a notifier_call
529  */
530 
531 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
532 		      struct list_head *head)
533 {
534 	struct vif_device *v;
535 	struct net_device *dev;
536 	struct in_device *in_dev;
537 
538 	if (vifi < 0 || vifi >= mrt->maxvif)
539 		return -EADDRNOTAVAIL;
540 
541 	v = &mrt->vif_table[vifi];
542 
543 	write_lock_bh(&mrt_lock);
544 	dev = v->dev;
545 	v->dev = NULL;
546 
547 	if (!dev) {
548 		write_unlock_bh(&mrt_lock);
549 		return -EADDRNOTAVAIL;
550 	}
551 
552 #ifdef CONFIG_IP_PIMSM
553 	if (vifi == mrt->mroute_reg_vif_num)
554 		mrt->mroute_reg_vif_num = -1;
555 #endif
556 
557 	if (vifi + 1 == mrt->maxvif) {
558 		int tmp;
559 
560 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
561 			if (VIF_EXISTS(mrt, tmp))
562 				break;
563 		}
564 		mrt->maxvif = tmp+1;
565 	}
566 
567 	write_unlock_bh(&mrt_lock);
568 
569 	dev_set_allmulti(dev, -1);
570 
571 	in_dev = __in_dev_get_rtnl(dev);
572 	if (in_dev) {
573 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
574 		ip_rt_multicast_event(in_dev);
575 	}
576 
577 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
578 		unregister_netdevice_queue(dev, head);
579 
580 	dev_put(dev);
581 	return 0;
582 }
583 
584 static void ipmr_cache_free_rcu(struct rcu_head *head)
585 {
586 	struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
587 
588 	kmem_cache_free(mrt_cachep, c);
589 }
590 
591 static inline void ipmr_cache_free(struct mfc_cache *c)
592 {
593 	call_rcu(&c->rcu, ipmr_cache_free_rcu);
594 }
595 
596 /* Destroy an unresolved cache entry, killing queued skbs
597  * and reporting error to netlink readers.
598  */
599 
600 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
601 {
602 	struct net *net = read_pnet(&mrt->net);
603 	struct sk_buff *skb;
604 	struct nlmsgerr *e;
605 
606 	atomic_dec(&mrt->cache_resolve_queue_len);
607 
608 	while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
609 		if (ip_hdr(skb)->version == 0) {
610 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
611 			nlh->nlmsg_type = NLMSG_ERROR;
612 			nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
613 			skb_trim(skb, nlh->nlmsg_len);
614 			e = NLMSG_DATA(nlh);
615 			e->error = -ETIMEDOUT;
616 			memset(&e->msg, 0, sizeof(e->msg));
617 
618 			rtnl_unicast(skb, net, NETLINK_CB(skb).pid);
619 		} else {
620 			kfree_skb(skb);
621 		}
622 	}
623 
624 	ipmr_cache_free(c);
625 }
626 
627 
628 /* Timer process for the unresolved queue. */
629 
630 static void ipmr_expire_process(unsigned long arg)
631 {
632 	struct mr_table *mrt = (struct mr_table *)arg;
633 	unsigned long now;
634 	unsigned long expires;
635 	struct mfc_cache *c, *next;
636 
637 	if (!spin_trylock(&mfc_unres_lock)) {
638 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
639 		return;
640 	}
641 
642 	if (list_empty(&mrt->mfc_unres_queue))
643 		goto out;
644 
645 	now = jiffies;
646 	expires = 10*HZ;
647 
648 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
649 		if (time_after(c->mfc_un.unres.expires, now)) {
650 			unsigned long interval = c->mfc_un.unres.expires - now;
651 			if (interval < expires)
652 				expires = interval;
653 			continue;
654 		}
655 
656 		list_del(&c->list);
657 		ipmr_destroy_unres(mrt, c);
658 	}
659 
660 	if (!list_empty(&mrt->mfc_unres_queue))
661 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
662 
663 out:
664 	spin_unlock(&mfc_unres_lock);
665 }
666 
667 /* Fill oifs list. It is called under write locked mrt_lock. */
668 
669 static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
670 				   unsigned char *ttls)
671 {
672 	int vifi;
673 
674 	cache->mfc_un.res.minvif = MAXVIFS;
675 	cache->mfc_un.res.maxvif = 0;
676 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
677 
678 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
679 		if (VIF_EXISTS(mrt, vifi) &&
680 		    ttls[vifi] && ttls[vifi] < 255) {
681 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
682 			if (cache->mfc_un.res.minvif > vifi)
683 				cache->mfc_un.res.minvif = vifi;
684 			if (cache->mfc_un.res.maxvif <= vifi)
685 				cache->mfc_un.res.maxvif = vifi + 1;
686 		}
687 	}
688 }
689 
690 static int vif_add(struct net *net, struct mr_table *mrt,
691 		   struct vifctl *vifc, int mrtsock)
692 {
693 	int vifi = vifc->vifc_vifi;
694 	struct vif_device *v = &mrt->vif_table[vifi];
695 	struct net_device *dev;
696 	struct in_device *in_dev;
697 	int err;
698 
699 	/* Is vif busy ? */
700 	if (VIF_EXISTS(mrt, vifi))
701 		return -EADDRINUSE;
702 
703 	switch (vifc->vifc_flags) {
704 #ifdef CONFIG_IP_PIMSM
705 	case VIFF_REGISTER:
706 		/*
707 		 * Special Purpose VIF in PIM
708 		 * All the packets will be sent to the daemon
709 		 */
710 		if (mrt->mroute_reg_vif_num >= 0)
711 			return -EADDRINUSE;
712 		dev = ipmr_reg_vif(net, mrt);
713 		if (!dev)
714 			return -ENOBUFS;
715 		err = dev_set_allmulti(dev, 1);
716 		if (err) {
717 			unregister_netdevice(dev);
718 			dev_put(dev);
719 			return err;
720 		}
721 		break;
722 #endif
723 	case VIFF_TUNNEL:
724 		dev = ipmr_new_tunnel(net, vifc);
725 		if (!dev)
726 			return -ENOBUFS;
727 		err = dev_set_allmulti(dev, 1);
728 		if (err) {
729 			ipmr_del_tunnel(dev, vifc);
730 			dev_put(dev);
731 			return err;
732 		}
733 		break;
734 
735 	case VIFF_USE_IFINDEX:
736 	case 0:
737 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
738 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
739 			if (dev && __in_dev_get_rtnl(dev) == NULL) {
740 				dev_put(dev);
741 				return -EADDRNOTAVAIL;
742 			}
743 		} else {
744 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
745 		}
746 		if (!dev)
747 			return -EADDRNOTAVAIL;
748 		err = dev_set_allmulti(dev, 1);
749 		if (err) {
750 			dev_put(dev);
751 			return err;
752 		}
753 		break;
754 	default:
755 		return -EINVAL;
756 	}
757 
758 	in_dev = __in_dev_get_rtnl(dev);
759 	if (!in_dev) {
760 		dev_put(dev);
761 		return -EADDRNOTAVAIL;
762 	}
763 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
764 	ip_rt_multicast_event(in_dev);
765 
766 	/* Fill in the VIF structures */
767 
768 	v->rate_limit = vifc->vifc_rate_limit;
769 	v->local = vifc->vifc_lcl_addr.s_addr;
770 	v->remote = vifc->vifc_rmt_addr.s_addr;
771 	v->flags = vifc->vifc_flags;
772 	if (!mrtsock)
773 		v->flags |= VIFF_STATIC;
774 	v->threshold = vifc->vifc_threshold;
775 	v->bytes_in = 0;
776 	v->bytes_out = 0;
777 	v->pkt_in = 0;
778 	v->pkt_out = 0;
779 	v->link = dev->ifindex;
780 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
781 		v->link = dev->iflink;
782 
783 	/* And finish update writing critical data */
784 	write_lock_bh(&mrt_lock);
785 	v->dev = dev;
786 #ifdef CONFIG_IP_PIMSM
787 	if (v->flags & VIFF_REGISTER)
788 		mrt->mroute_reg_vif_num = vifi;
789 #endif
790 	if (vifi+1 > mrt->maxvif)
791 		mrt->maxvif = vifi+1;
792 	write_unlock_bh(&mrt_lock);
793 	return 0;
794 }
795 
796 /* called with rcu_read_lock() */
797 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
798 					 __be32 origin,
799 					 __be32 mcastgrp)
800 {
801 	int line = MFC_HASH(mcastgrp, origin);
802 	struct mfc_cache *c;
803 
804 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list) {
805 		if (c->mfc_origin == origin && c->mfc_mcastgrp == mcastgrp)
806 			return c;
807 	}
808 	return NULL;
809 }
810 
811 /*
812  *	Allocate a multicast cache entry
813  */
814 static struct mfc_cache *ipmr_cache_alloc(void)
815 {
816 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
817 
818 	if (c)
819 		c->mfc_un.res.minvif = MAXVIFS;
820 	return c;
821 }
822 
823 static struct mfc_cache *ipmr_cache_alloc_unres(void)
824 {
825 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
826 
827 	if (c) {
828 		skb_queue_head_init(&c->mfc_un.unres.unresolved);
829 		c->mfc_un.unres.expires = jiffies + 10*HZ;
830 	}
831 	return c;
832 }
833 
834 /*
835  *	A cache entry has gone into a resolved state from queued
836  */
837 
838 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
839 			       struct mfc_cache *uc, struct mfc_cache *c)
840 {
841 	struct sk_buff *skb;
842 	struct nlmsgerr *e;
843 
844 	/* Play the pending entries through our router */
845 
846 	while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
847 		if (ip_hdr(skb)->version == 0) {
848 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
849 
850 			if (__ipmr_fill_mroute(mrt, skb, c, NLMSG_DATA(nlh)) > 0) {
851 				nlh->nlmsg_len = skb_tail_pointer(skb) -
852 						 (u8 *)nlh;
853 			} else {
854 				nlh->nlmsg_type = NLMSG_ERROR;
855 				nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
856 				skb_trim(skb, nlh->nlmsg_len);
857 				e = NLMSG_DATA(nlh);
858 				e->error = -EMSGSIZE;
859 				memset(&e->msg, 0, sizeof(e->msg));
860 			}
861 
862 			rtnl_unicast(skb, net, NETLINK_CB(skb).pid);
863 		} else {
864 			ip_mr_forward(net, mrt, skb, c, 0);
865 		}
866 	}
867 }
868 
869 /*
870  *	Bounce a cache query up to mrouted. We could use netlink for this but mrouted
871  *	expects the following bizarre scheme.
872  *
873  *	Called under mrt_lock.
874  */
875 
876 static int ipmr_cache_report(struct mr_table *mrt,
877 			     struct sk_buff *pkt, vifi_t vifi, int assert)
878 {
879 	struct sk_buff *skb;
880 	const int ihl = ip_hdrlen(pkt);
881 	struct igmphdr *igmp;
882 	struct igmpmsg *msg;
883 	struct sock *mroute_sk;
884 	int ret;
885 
886 #ifdef CONFIG_IP_PIMSM
887 	if (assert == IGMPMSG_WHOLEPKT)
888 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
889 	else
890 #endif
891 		skb = alloc_skb(128, GFP_ATOMIC);
892 
893 	if (!skb)
894 		return -ENOBUFS;
895 
896 #ifdef CONFIG_IP_PIMSM
897 	if (assert == IGMPMSG_WHOLEPKT) {
898 		/* Ugly, but we have no choice with this interface.
899 		 * Duplicate old header, fix ihl, length etc.
900 		 * And all this only to mangle msg->im_msgtype and
901 		 * to set msg->im_mbz to "mbz" :-)
902 		 */
903 		skb_push(skb, sizeof(struct iphdr));
904 		skb_reset_network_header(skb);
905 		skb_reset_transport_header(skb);
906 		msg = (struct igmpmsg *)skb_network_header(skb);
907 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
908 		msg->im_msgtype = IGMPMSG_WHOLEPKT;
909 		msg->im_mbz = 0;
910 		msg->im_vif = mrt->mroute_reg_vif_num;
911 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
912 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
913 					     sizeof(struct iphdr));
914 	} else
915 #endif
916 	{
917 
918 	/* Copy the IP header */
919 
920 	skb->network_header = skb->tail;
921 	skb_put(skb, ihl);
922 	skb_copy_to_linear_data(skb, pkt->data, ihl);
923 	ip_hdr(skb)->protocol = 0;	/* Flag to the kernel this is a route add */
924 	msg = (struct igmpmsg *)skb_network_header(skb);
925 	msg->im_vif = vifi;
926 	skb_dst_set(skb, dst_clone(skb_dst(pkt)));
927 
928 	/* Add our header */
929 
930 	igmp = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
931 	igmp->type	=
932 	msg->im_msgtype = assert;
933 	igmp->code	= 0;
934 	ip_hdr(skb)->tot_len = htons(skb->len);		/* Fix the length */
935 	skb->transport_header = skb->network_header;
936 	}
937 
938 	rcu_read_lock();
939 	mroute_sk = rcu_dereference(mrt->mroute_sk);
940 	if (mroute_sk == NULL) {
941 		rcu_read_unlock();
942 		kfree_skb(skb);
943 		return -EINVAL;
944 	}
945 
946 	/* Deliver to mrouted */
947 
948 	ret = sock_queue_rcv_skb(mroute_sk, skb);
949 	rcu_read_unlock();
950 	if (ret < 0) {
951 		if (net_ratelimit())
952 			printk(KERN_WARNING "mroute: pending queue full, dropping entries.\n");
953 		kfree_skb(skb);
954 	}
955 
956 	return ret;
957 }
958 
959 /*
960  *	Queue a packet for resolution. It gets locked cache entry!
961  */
962 
963 static int
964 ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi, struct sk_buff *skb)
965 {
966 	bool found = false;
967 	int err;
968 	struct mfc_cache *c;
969 	const struct iphdr *iph = ip_hdr(skb);
970 
971 	spin_lock_bh(&mfc_unres_lock);
972 	list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
973 		if (c->mfc_mcastgrp == iph->daddr &&
974 		    c->mfc_origin == iph->saddr) {
975 			found = true;
976 			break;
977 		}
978 	}
979 
980 	if (!found) {
981 		/* Create a new entry if allowable */
982 
983 		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
984 		    (c = ipmr_cache_alloc_unres()) == NULL) {
985 			spin_unlock_bh(&mfc_unres_lock);
986 
987 			kfree_skb(skb);
988 			return -ENOBUFS;
989 		}
990 
991 		/* Fill in the new cache entry */
992 
993 		c->mfc_parent	= -1;
994 		c->mfc_origin	= iph->saddr;
995 		c->mfc_mcastgrp	= iph->daddr;
996 
997 		/* Reflect first query at mrouted. */
998 
999 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1000 		if (err < 0) {
1001 			/* If the report failed throw the cache entry
1002 			   out - Brad Parker
1003 			 */
1004 			spin_unlock_bh(&mfc_unres_lock);
1005 
1006 			ipmr_cache_free(c);
1007 			kfree_skb(skb);
1008 			return err;
1009 		}
1010 
1011 		atomic_inc(&mrt->cache_resolve_queue_len);
1012 		list_add(&c->list, &mrt->mfc_unres_queue);
1013 
1014 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1015 			mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1016 	}
1017 
1018 	/* See if we can append the packet */
1019 
1020 	if (c->mfc_un.unres.unresolved.qlen > 3) {
1021 		kfree_skb(skb);
1022 		err = -ENOBUFS;
1023 	} else {
1024 		skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1025 		err = 0;
1026 	}
1027 
1028 	spin_unlock_bh(&mfc_unres_lock);
1029 	return err;
1030 }
1031 
1032 /*
1033  *	MFC cache manipulation by user space mroute daemon
1034  */
1035 
1036 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc)
1037 {
1038 	int line;
1039 	struct mfc_cache *c, *next;
1040 
1041 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1042 
1043 	list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[line], list) {
1044 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1045 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
1046 			list_del_rcu(&c->list);
1047 
1048 			ipmr_cache_free(c);
1049 			return 0;
1050 		}
1051 	}
1052 	return -ENOENT;
1053 }
1054 
1055 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1056 			struct mfcctl *mfc, int mrtsock)
1057 {
1058 	bool found = false;
1059 	int line;
1060 	struct mfc_cache *uc, *c;
1061 
1062 	if (mfc->mfcc_parent >= MAXVIFS)
1063 		return -ENFILE;
1064 
1065 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1066 
1067 	list_for_each_entry(c, &mrt->mfc_cache_array[line], list) {
1068 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1069 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
1070 			found = true;
1071 			break;
1072 		}
1073 	}
1074 
1075 	if (found) {
1076 		write_lock_bh(&mrt_lock);
1077 		c->mfc_parent = mfc->mfcc_parent;
1078 		ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1079 		if (!mrtsock)
1080 			c->mfc_flags |= MFC_STATIC;
1081 		write_unlock_bh(&mrt_lock);
1082 		return 0;
1083 	}
1084 
1085 	if (!ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1086 		return -EINVAL;
1087 
1088 	c = ipmr_cache_alloc();
1089 	if (c == NULL)
1090 		return -ENOMEM;
1091 
1092 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1093 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1094 	c->mfc_parent = mfc->mfcc_parent;
1095 	ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1096 	if (!mrtsock)
1097 		c->mfc_flags |= MFC_STATIC;
1098 
1099 	list_add_rcu(&c->list, &mrt->mfc_cache_array[line]);
1100 
1101 	/*
1102 	 *	Check to see if we resolved a queued list. If so we
1103 	 *	need to send on the frames and tidy up.
1104 	 */
1105 	found = false;
1106 	spin_lock_bh(&mfc_unres_lock);
1107 	list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1108 		if (uc->mfc_origin == c->mfc_origin &&
1109 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1110 			list_del(&uc->list);
1111 			atomic_dec(&mrt->cache_resolve_queue_len);
1112 			found = true;
1113 			break;
1114 		}
1115 	}
1116 	if (list_empty(&mrt->mfc_unres_queue))
1117 		del_timer(&mrt->ipmr_expire_timer);
1118 	spin_unlock_bh(&mfc_unres_lock);
1119 
1120 	if (found) {
1121 		ipmr_cache_resolve(net, mrt, uc, c);
1122 		ipmr_cache_free(uc);
1123 	}
1124 	return 0;
1125 }
1126 
1127 /*
1128  *	Close the multicast socket, and clear the vif tables etc
1129  */
1130 
1131 static void mroute_clean_tables(struct mr_table *mrt)
1132 {
1133 	int i;
1134 	LIST_HEAD(list);
1135 	struct mfc_cache *c, *next;
1136 
1137 	/* Shut down all active vif entries */
1138 
1139 	for (i = 0; i < mrt->maxvif; i++) {
1140 		if (!(mrt->vif_table[i].flags & VIFF_STATIC))
1141 			vif_delete(mrt, i, 0, &list);
1142 	}
1143 	unregister_netdevice_many(&list);
1144 
1145 	/* Wipe the cache */
1146 
1147 	for (i = 0; i < MFC_LINES; i++) {
1148 		list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[i], list) {
1149 			if (c->mfc_flags & MFC_STATIC)
1150 				continue;
1151 			list_del_rcu(&c->list);
1152 			ipmr_cache_free(c);
1153 		}
1154 	}
1155 
1156 	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1157 		spin_lock_bh(&mfc_unres_lock);
1158 		list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
1159 			list_del(&c->list);
1160 			ipmr_destroy_unres(mrt, c);
1161 		}
1162 		spin_unlock_bh(&mfc_unres_lock);
1163 	}
1164 }
1165 
1166 /* called from ip_ra_control(), before an RCU grace period,
1167  * we dont need to call synchronize_rcu() here
1168  */
1169 static void mrtsock_destruct(struct sock *sk)
1170 {
1171 	struct net *net = sock_net(sk);
1172 	struct mr_table *mrt;
1173 
1174 	rtnl_lock();
1175 	ipmr_for_each_table(mrt, net) {
1176 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1177 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1178 			rcu_assign_pointer(mrt->mroute_sk, NULL);
1179 			mroute_clean_tables(mrt);
1180 		}
1181 	}
1182 	rtnl_unlock();
1183 }
1184 
1185 /*
1186  *	Socket options and virtual interface manipulation. The whole
1187  *	virtual interface system is a complete heap, but unfortunately
1188  *	that's how BSD mrouted happens to think. Maybe one day with a proper
1189  *	MOSPF/PIM router set up we can clean this up.
1190  */
1191 
1192 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen)
1193 {
1194 	int ret;
1195 	struct vifctl vif;
1196 	struct mfcctl mfc;
1197 	struct net *net = sock_net(sk);
1198 	struct mr_table *mrt;
1199 
1200 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1201 	if (mrt == NULL)
1202 		return -ENOENT;
1203 
1204 	if (optname != MRT_INIT) {
1205 		if (sk != rcu_dereference_raw(mrt->mroute_sk) &&
1206 		    !capable(CAP_NET_ADMIN))
1207 			return -EACCES;
1208 	}
1209 
1210 	switch (optname) {
1211 	case MRT_INIT:
1212 		if (sk->sk_type != SOCK_RAW ||
1213 		    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1214 			return -EOPNOTSUPP;
1215 		if (optlen != sizeof(int))
1216 			return -ENOPROTOOPT;
1217 
1218 		rtnl_lock();
1219 		if (rtnl_dereference(mrt->mroute_sk)) {
1220 			rtnl_unlock();
1221 			return -EADDRINUSE;
1222 		}
1223 
1224 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1225 		if (ret == 0) {
1226 			rcu_assign_pointer(mrt->mroute_sk, sk);
1227 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1228 		}
1229 		rtnl_unlock();
1230 		return ret;
1231 	case MRT_DONE:
1232 		if (sk != rcu_dereference_raw(mrt->mroute_sk))
1233 			return -EACCES;
1234 		return ip_ra_control(sk, 0, NULL);
1235 	case MRT_ADD_VIF:
1236 	case MRT_DEL_VIF:
1237 		if (optlen != sizeof(vif))
1238 			return -EINVAL;
1239 		if (copy_from_user(&vif, optval, sizeof(vif)))
1240 			return -EFAULT;
1241 		if (vif.vifc_vifi >= MAXVIFS)
1242 			return -ENFILE;
1243 		rtnl_lock();
1244 		if (optname == MRT_ADD_VIF) {
1245 			ret = vif_add(net, mrt, &vif,
1246 				      sk == rtnl_dereference(mrt->mroute_sk));
1247 		} else {
1248 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1249 		}
1250 		rtnl_unlock();
1251 		return ret;
1252 
1253 		/*
1254 		 *	Manipulate the forwarding caches. These live
1255 		 *	in a sort of kernel/user symbiosis.
1256 		 */
1257 	case MRT_ADD_MFC:
1258 	case MRT_DEL_MFC:
1259 		if (optlen != sizeof(mfc))
1260 			return -EINVAL;
1261 		if (copy_from_user(&mfc, optval, sizeof(mfc)))
1262 			return -EFAULT;
1263 		rtnl_lock();
1264 		if (optname == MRT_DEL_MFC)
1265 			ret = ipmr_mfc_delete(mrt, &mfc);
1266 		else
1267 			ret = ipmr_mfc_add(net, mrt, &mfc,
1268 					   sk == rtnl_dereference(mrt->mroute_sk));
1269 		rtnl_unlock();
1270 		return ret;
1271 		/*
1272 		 *	Control PIM assert.
1273 		 */
1274 	case MRT_ASSERT:
1275 	{
1276 		int v;
1277 		if (get_user(v, (int __user *)optval))
1278 			return -EFAULT;
1279 		mrt->mroute_do_assert = (v) ? 1 : 0;
1280 		return 0;
1281 	}
1282 #ifdef CONFIG_IP_PIMSM
1283 	case MRT_PIM:
1284 	{
1285 		int v;
1286 
1287 		if (get_user(v, (int __user *)optval))
1288 			return -EFAULT;
1289 		v = (v) ? 1 : 0;
1290 
1291 		rtnl_lock();
1292 		ret = 0;
1293 		if (v != mrt->mroute_do_pim) {
1294 			mrt->mroute_do_pim = v;
1295 			mrt->mroute_do_assert = v;
1296 		}
1297 		rtnl_unlock();
1298 		return ret;
1299 	}
1300 #endif
1301 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
1302 	case MRT_TABLE:
1303 	{
1304 		u32 v;
1305 
1306 		if (optlen != sizeof(u32))
1307 			return -EINVAL;
1308 		if (get_user(v, (u32 __user *)optval))
1309 			return -EFAULT;
1310 
1311 		rtnl_lock();
1312 		ret = 0;
1313 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1314 			ret = -EBUSY;
1315 		} else {
1316 			if (!ipmr_new_table(net, v))
1317 				ret = -ENOMEM;
1318 			raw_sk(sk)->ipmr_table = v;
1319 		}
1320 		rtnl_unlock();
1321 		return ret;
1322 	}
1323 #endif
1324 	/*
1325 	 *	Spurious command, or MRT_VERSION which you cannot
1326 	 *	set.
1327 	 */
1328 	default:
1329 		return -ENOPROTOOPT;
1330 	}
1331 }
1332 
1333 /*
1334  *	Getsock opt support for the multicast routing system.
1335  */
1336 
1337 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1338 {
1339 	int olr;
1340 	int val;
1341 	struct net *net = sock_net(sk);
1342 	struct mr_table *mrt;
1343 
1344 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1345 	if (mrt == NULL)
1346 		return -ENOENT;
1347 
1348 	if (optname != MRT_VERSION &&
1349 #ifdef CONFIG_IP_PIMSM
1350 	   optname != MRT_PIM &&
1351 #endif
1352 	   optname != MRT_ASSERT)
1353 		return -ENOPROTOOPT;
1354 
1355 	if (get_user(olr, optlen))
1356 		return -EFAULT;
1357 
1358 	olr = min_t(unsigned int, olr, sizeof(int));
1359 	if (olr < 0)
1360 		return -EINVAL;
1361 
1362 	if (put_user(olr, optlen))
1363 		return -EFAULT;
1364 	if (optname == MRT_VERSION)
1365 		val = 0x0305;
1366 #ifdef CONFIG_IP_PIMSM
1367 	else if (optname == MRT_PIM)
1368 		val = mrt->mroute_do_pim;
1369 #endif
1370 	else
1371 		val = mrt->mroute_do_assert;
1372 	if (copy_to_user(optval, &val, olr))
1373 		return -EFAULT;
1374 	return 0;
1375 }
1376 
1377 /*
1378  *	The IP multicast ioctl support routines.
1379  */
1380 
1381 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1382 {
1383 	struct sioc_sg_req sr;
1384 	struct sioc_vif_req vr;
1385 	struct vif_device *vif;
1386 	struct mfc_cache *c;
1387 	struct net *net = sock_net(sk);
1388 	struct mr_table *mrt;
1389 
1390 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1391 	if (mrt == NULL)
1392 		return -ENOENT;
1393 
1394 	switch (cmd) {
1395 	case SIOCGETVIFCNT:
1396 		if (copy_from_user(&vr, arg, sizeof(vr)))
1397 			return -EFAULT;
1398 		if (vr.vifi >= mrt->maxvif)
1399 			return -EINVAL;
1400 		read_lock(&mrt_lock);
1401 		vif = &mrt->vif_table[vr.vifi];
1402 		if (VIF_EXISTS(mrt, vr.vifi)) {
1403 			vr.icount = vif->pkt_in;
1404 			vr.ocount = vif->pkt_out;
1405 			vr.ibytes = vif->bytes_in;
1406 			vr.obytes = vif->bytes_out;
1407 			read_unlock(&mrt_lock);
1408 
1409 			if (copy_to_user(arg, &vr, sizeof(vr)))
1410 				return -EFAULT;
1411 			return 0;
1412 		}
1413 		read_unlock(&mrt_lock);
1414 		return -EADDRNOTAVAIL;
1415 	case SIOCGETSGCNT:
1416 		if (copy_from_user(&sr, arg, sizeof(sr)))
1417 			return -EFAULT;
1418 
1419 		rcu_read_lock();
1420 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1421 		if (c) {
1422 			sr.pktcnt = c->mfc_un.res.pkt;
1423 			sr.bytecnt = c->mfc_un.res.bytes;
1424 			sr.wrong_if = c->mfc_un.res.wrong_if;
1425 			rcu_read_unlock();
1426 
1427 			if (copy_to_user(arg, &sr, sizeof(sr)))
1428 				return -EFAULT;
1429 			return 0;
1430 		}
1431 		rcu_read_unlock();
1432 		return -EADDRNOTAVAIL;
1433 	default:
1434 		return -ENOIOCTLCMD;
1435 	}
1436 }
1437 
1438 #ifdef CONFIG_COMPAT
1439 struct compat_sioc_sg_req {
1440 	struct in_addr src;
1441 	struct in_addr grp;
1442 	compat_ulong_t pktcnt;
1443 	compat_ulong_t bytecnt;
1444 	compat_ulong_t wrong_if;
1445 };
1446 
1447 struct compat_sioc_vif_req {
1448 	vifi_t	vifi;		/* Which iface */
1449 	compat_ulong_t icount;
1450 	compat_ulong_t ocount;
1451 	compat_ulong_t ibytes;
1452 	compat_ulong_t obytes;
1453 };
1454 
1455 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1456 {
1457 	struct compat_sioc_sg_req sr;
1458 	struct compat_sioc_vif_req vr;
1459 	struct vif_device *vif;
1460 	struct mfc_cache *c;
1461 	struct net *net = sock_net(sk);
1462 	struct mr_table *mrt;
1463 
1464 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1465 	if (mrt == NULL)
1466 		return -ENOENT;
1467 
1468 	switch (cmd) {
1469 	case SIOCGETVIFCNT:
1470 		if (copy_from_user(&vr, arg, sizeof(vr)))
1471 			return -EFAULT;
1472 		if (vr.vifi >= mrt->maxvif)
1473 			return -EINVAL;
1474 		read_lock(&mrt_lock);
1475 		vif = &mrt->vif_table[vr.vifi];
1476 		if (VIF_EXISTS(mrt, vr.vifi)) {
1477 			vr.icount = vif->pkt_in;
1478 			vr.ocount = vif->pkt_out;
1479 			vr.ibytes = vif->bytes_in;
1480 			vr.obytes = vif->bytes_out;
1481 			read_unlock(&mrt_lock);
1482 
1483 			if (copy_to_user(arg, &vr, sizeof(vr)))
1484 				return -EFAULT;
1485 			return 0;
1486 		}
1487 		read_unlock(&mrt_lock);
1488 		return -EADDRNOTAVAIL;
1489 	case SIOCGETSGCNT:
1490 		if (copy_from_user(&sr, arg, sizeof(sr)))
1491 			return -EFAULT;
1492 
1493 		rcu_read_lock();
1494 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1495 		if (c) {
1496 			sr.pktcnt = c->mfc_un.res.pkt;
1497 			sr.bytecnt = c->mfc_un.res.bytes;
1498 			sr.wrong_if = c->mfc_un.res.wrong_if;
1499 			rcu_read_unlock();
1500 
1501 			if (copy_to_user(arg, &sr, sizeof(sr)))
1502 				return -EFAULT;
1503 			return 0;
1504 		}
1505 		rcu_read_unlock();
1506 		return -EADDRNOTAVAIL;
1507 	default:
1508 		return -ENOIOCTLCMD;
1509 	}
1510 }
1511 #endif
1512 
1513 
1514 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1515 {
1516 	struct net_device *dev = ptr;
1517 	struct net *net = dev_net(dev);
1518 	struct mr_table *mrt;
1519 	struct vif_device *v;
1520 	int ct;
1521 	LIST_HEAD(list);
1522 
1523 	if (event != NETDEV_UNREGISTER)
1524 		return NOTIFY_DONE;
1525 
1526 	ipmr_for_each_table(mrt, net) {
1527 		v = &mrt->vif_table[0];
1528 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1529 			if (v->dev == dev)
1530 				vif_delete(mrt, ct, 1, &list);
1531 		}
1532 	}
1533 	unregister_netdevice_many(&list);
1534 	return NOTIFY_DONE;
1535 }
1536 
1537 
1538 static struct notifier_block ip_mr_notifier = {
1539 	.notifier_call = ipmr_device_event,
1540 };
1541 
1542 /*
1543  *	Encapsulate a packet by attaching a valid IPIP header to it.
1544  *	This avoids tunnel drivers and other mess and gives us the speed so
1545  *	important for multicast video.
1546  */
1547 
1548 static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr)
1549 {
1550 	struct iphdr *iph;
1551 	struct iphdr *old_iph = ip_hdr(skb);
1552 
1553 	skb_push(skb, sizeof(struct iphdr));
1554 	skb->transport_header = skb->network_header;
1555 	skb_reset_network_header(skb);
1556 	iph = ip_hdr(skb);
1557 
1558 	iph->version	=	4;
1559 	iph->tos	=	old_iph->tos;
1560 	iph->ttl	=	old_iph->ttl;
1561 	iph->frag_off	=	0;
1562 	iph->daddr	=	daddr;
1563 	iph->saddr	=	saddr;
1564 	iph->protocol	=	IPPROTO_IPIP;
1565 	iph->ihl	=	5;
1566 	iph->tot_len	=	htons(skb->len);
1567 	ip_select_ident(iph, skb_dst(skb), NULL);
1568 	ip_send_check(iph);
1569 
1570 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1571 	nf_reset(skb);
1572 }
1573 
1574 static inline int ipmr_forward_finish(struct sk_buff *skb)
1575 {
1576 	struct ip_options *opt = &(IPCB(skb)->opt);
1577 
1578 	IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
1579 
1580 	if (unlikely(opt->optlen))
1581 		ip_forward_options(skb);
1582 
1583 	return dst_output(skb);
1584 }
1585 
1586 /*
1587  *	Processing handlers for ipmr_forward
1588  */
1589 
1590 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1591 			    struct sk_buff *skb, struct mfc_cache *c, int vifi)
1592 {
1593 	const struct iphdr *iph = ip_hdr(skb);
1594 	struct vif_device *vif = &mrt->vif_table[vifi];
1595 	struct net_device *dev;
1596 	struct rtable *rt;
1597 	int    encap = 0;
1598 
1599 	if (vif->dev == NULL)
1600 		goto out_free;
1601 
1602 #ifdef CONFIG_IP_PIMSM
1603 	if (vif->flags & VIFF_REGISTER) {
1604 		vif->pkt_out++;
1605 		vif->bytes_out += skb->len;
1606 		vif->dev->stats.tx_bytes += skb->len;
1607 		vif->dev->stats.tx_packets++;
1608 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1609 		goto out_free;
1610 	}
1611 #endif
1612 
1613 	if (vif->flags & VIFF_TUNNEL) {
1614 		struct flowi fl = {
1615 			.oif = vif->link,
1616 			.fl4_dst = vif->remote,
1617 			.fl4_src = vif->local,
1618 			.fl4_tos = RT_TOS(iph->tos),
1619 			.proto = IPPROTO_IPIP
1620 		};
1621 
1622 		if (ip_route_output_key(net, &rt, &fl))
1623 			goto out_free;
1624 		encap = sizeof(struct iphdr);
1625 	} else {
1626 		struct flowi fl = {
1627 			.oif = vif->link,
1628 			.fl4_dst = iph->daddr,
1629 			.fl4_tos = RT_TOS(iph->tos),
1630 			.proto = IPPROTO_IPIP
1631 		};
1632 
1633 		if (ip_route_output_key(net, &rt, &fl))
1634 			goto out_free;
1635 	}
1636 
1637 	dev = rt->dst.dev;
1638 
1639 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1640 		/* Do not fragment multicasts. Alas, IPv4 does not
1641 		 * allow to send ICMP, so that packets will disappear
1642 		 * to blackhole.
1643 		 */
1644 
1645 		IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
1646 		ip_rt_put(rt);
1647 		goto out_free;
1648 	}
1649 
1650 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1651 
1652 	if (skb_cow(skb, encap)) {
1653 		ip_rt_put(rt);
1654 		goto out_free;
1655 	}
1656 
1657 	vif->pkt_out++;
1658 	vif->bytes_out += skb->len;
1659 
1660 	skb_dst_drop(skb);
1661 	skb_dst_set(skb, &rt->dst);
1662 	ip_decrease_ttl(ip_hdr(skb));
1663 
1664 	/* FIXME: forward and output firewalls used to be called here.
1665 	 * What do we do with netfilter? -- RR
1666 	 */
1667 	if (vif->flags & VIFF_TUNNEL) {
1668 		ip_encap(skb, vif->local, vif->remote);
1669 		/* FIXME: extra output firewall step used to be here. --RR */
1670 		vif->dev->stats.tx_packets++;
1671 		vif->dev->stats.tx_bytes += skb->len;
1672 	}
1673 
1674 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1675 
1676 	/*
1677 	 * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1678 	 * not only before forwarding, but after forwarding on all output
1679 	 * interfaces. It is clear, if mrouter runs a multicasting
1680 	 * program, it should receive packets not depending to what interface
1681 	 * program is joined.
1682 	 * If we will not make it, the program will have to join on all
1683 	 * interfaces. On the other hand, multihoming host (or router, but
1684 	 * not mrouter) cannot join to more than one interface - it will
1685 	 * result in receiving multiple packets.
1686 	 */
1687 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, skb, skb->dev, dev,
1688 		ipmr_forward_finish);
1689 	return;
1690 
1691 out_free:
1692 	kfree_skb(skb);
1693 }
1694 
1695 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1696 {
1697 	int ct;
1698 
1699 	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1700 		if (mrt->vif_table[ct].dev == dev)
1701 			break;
1702 	}
1703 	return ct;
1704 }
1705 
1706 /* "local" means that we should preserve one skb (for local delivery) */
1707 
1708 static int ip_mr_forward(struct net *net, struct mr_table *mrt,
1709 			 struct sk_buff *skb, struct mfc_cache *cache,
1710 			 int local)
1711 {
1712 	int psend = -1;
1713 	int vif, ct;
1714 
1715 	vif = cache->mfc_parent;
1716 	cache->mfc_un.res.pkt++;
1717 	cache->mfc_un.res.bytes += skb->len;
1718 
1719 	/*
1720 	 * Wrong interface: drop packet and (maybe) send PIM assert.
1721 	 */
1722 	if (mrt->vif_table[vif].dev != skb->dev) {
1723 		int true_vifi;
1724 
1725 		if (rt_is_output_route(skb_rtable(skb))) {
1726 			/* It is our own packet, looped back.
1727 			 * Very complicated situation...
1728 			 *
1729 			 * The best workaround until routing daemons will be
1730 			 * fixed is not to redistribute packet, if it was
1731 			 * send through wrong interface. It means, that
1732 			 * multicast applications WILL NOT work for
1733 			 * (S,G), which have default multicast route pointing
1734 			 * to wrong oif. In any case, it is not a good
1735 			 * idea to use multicasting applications on router.
1736 			 */
1737 			goto dont_forward;
1738 		}
1739 
1740 		cache->mfc_un.res.wrong_if++;
1741 		true_vifi = ipmr_find_vif(mrt, skb->dev);
1742 
1743 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
1744 		    /* pimsm uses asserts, when switching from RPT to SPT,
1745 		     * so that we cannot check that packet arrived on an oif.
1746 		     * It is bad, but otherwise we would need to move pretty
1747 		     * large chunk of pimd to kernel. Ough... --ANK
1748 		     */
1749 		    (mrt->mroute_do_pim ||
1750 		     cache->mfc_un.res.ttls[true_vifi] < 255) &&
1751 		    time_after(jiffies,
1752 			       cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1753 			cache->mfc_un.res.last_assert = jiffies;
1754 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1755 		}
1756 		goto dont_forward;
1757 	}
1758 
1759 	mrt->vif_table[vif].pkt_in++;
1760 	mrt->vif_table[vif].bytes_in += skb->len;
1761 
1762 	/*
1763 	 *	Forward the frame
1764 	 */
1765 	for (ct = cache->mfc_un.res.maxvif - 1;
1766 	     ct >= cache->mfc_un.res.minvif; ct--) {
1767 		if (ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1768 			if (psend != -1) {
1769 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1770 
1771 				if (skb2)
1772 					ipmr_queue_xmit(net, mrt, skb2, cache,
1773 							psend);
1774 			}
1775 			psend = ct;
1776 		}
1777 	}
1778 	if (psend != -1) {
1779 		if (local) {
1780 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1781 
1782 			if (skb2)
1783 				ipmr_queue_xmit(net, mrt, skb2, cache, psend);
1784 		} else {
1785 			ipmr_queue_xmit(net, mrt, skb, cache, psend);
1786 			return 0;
1787 		}
1788 	}
1789 
1790 dont_forward:
1791 	if (!local)
1792 		kfree_skb(skb);
1793 	return 0;
1794 }
1795 
1796 
1797 /*
1798  *	Multicast packets for forwarding arrive here
1799  *	Called with rcu_read_lock();
1800  */
1801 
1802 int ip_mr_input(struct sk_buff *skb)
1803 {
1804 	struct mfc_cache *cache;
1805 	struct net *net = dev_net(skb->dev);
1806 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
1807 	struct mr_table *mrt;
1808 	int err;
1809 
1810 	/* Packet is looped back after forward, it should not be
1811 	 * forwarded second time, but still can be delivered locally.
1812 	 */
1813 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
1814 		goto dont_forward;
1815 
1816 	err = ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt);
1817 	if (err < 0) {
1818 		kfree_skb(skb);
1819 		return err;
1820 	}
1821 
1822 	if (!local) {
1823 		if (IPCB(skb)->opt.router_alert) {
1824 			if (ip_call_ra_chain(skb))
1825 				return 0;
1826 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
1827 			/* IGMPv1 (and broken IGMPv2 implementations sort of
1828 			 * Cisco IOS <= 11.2(8)) do not put router alert
1829 			 * option to IGMP packets destined to routable
1830 			 * groups. It is very bad, because it means
1831 			 * that we can forward NO IGMP messages.
1832 			 */
1833 			struct sock *mroute_sk;
1834 
1835 			mroute_sk = rcu_dereference(mrt->mroute_sk);
1836 			if (mroute_sk) {
1837 				nf_reset(skb);
1838 				raw_rcv(mroute_sk, skb);
1839 				return 0;
1840 			}
1841 		    }
1842 	}
1843 
1844 	/* already under rcu_read_lock() */
1845 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
1846 
1847 	/*
1848 	 *	No usable cache entry
1849 	 */
1850 	if (cache == NULL) {
1851 		int vif;
1852 
1853 		if (local) {
1854 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1855 			ip_local_deliver(skb);
1856 			if (skb2 == NULL)
1857 				return -ENOBUFS;
1858 			skb = skb2;
1859 		}
1860 
1861 		read_lock(&mrt_lock);
1862 		vif = ipmr_find_vif(mrt, skb->dev);
1863 		if (vif >= 0) {
1864 			int err2 = ipmr_cache_unresolved(mrt, vif, skb);
1865 			read_unlock(&mrt_lock);
1866 
1867 			return err2;
1868 		}
1869 		read_unlock(&mrt_lock);
1870 		kfree_skb(skb);
1871 		return -ENODEV;
1872 	}
1873 
1874 	read_lock(&mrt_lock);
1875 	ip_mr_forward(net, mrt, skb, cache, local);
1876 	read_unlock(&mrt_lock);
1877 
1878 	if (local)
1879 		return ip_local_deliver(skb);
1880 
1881 	return 0;
1882 
1883 dont_forward:
1884 	if (local)
1885 		return ip_local_deliver(skb);
1886 	kfree_skb(skb);
1887 	return 0;
1888 }
1889 
1890 #ifdef CONFIG_IP_PIMSM
1891 /* called with rcu_read_lock() */
1892 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
1893 		     unsigned int pimlen)
1894 {
1895 	struct net_device *reg_dev = NULL;
1896 	struct iphdr *encap;
1897 
1898 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
1899 	/*
1900 	 * Check that:
1901 	 * a. packet is really sent to a multicast group
1902 	 * b. packet is not a NULL-REGISTER
1903 	 * c. packet is not truncated
1904 	 */
1905 	if (!ipv4_is_multicast(encap->daddr) ||
1906 	    encap->tot_len == 0 ||
1907 	    ntohs(encap->tot_len) + pimlen > skb->len)
1908 		return 1;
1909 
1910 	read_lock(&mrt_lock);
1911 	if (mrt->mroute_reg_vif_num >= 0)
1912 		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
1913 	read_unlock(&mrt_lock);
1914 
1915 	if (reg_dev == NULL)
1916 		return 1;
1917 
1918 	skb->mac_header = skb->network_header;
1919 	skb_pull(skb, (u8 *)encap - skb->data);
1920 	skb_reset_network_header(skb);
1921 	skb->protocol = htons(ETH_P_IP);
1922 	skb->ip_summed = CHECKSUM_NONE;
1923 	skb->pkt_type = PACKET_HOST;
1924 
1925 	skb_tunnel_rx(skb, reg_dev);
1926 
1927 	netif_rx(skb);
1928 
1929 	return NET_RX_SUCCESS;
1930 }
1931 #endif
1932 
1933 #ifdef CONFIG_IP_PIMSM_V1
1934 /*
1935  * Handle IGMP messages of PIMv1
1936  */
1937 
1938 int pim_rcv_v1(struct sk_buff *skb)
1939 {
1940 	struct igmphdr *pim;
1941 	struct net *net = dev_net(skb->dev);
1942 	struct mr_table *mrt;
1943 
1944 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
1945 		goto drop;
1946 
1947 	pim = igmp_hdr(skb);
1948 
1949 	if (ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt) < 0)
1950 		goto drop;
1951 
1952 	if (!mrt->mroute_do_pim ||
1953 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
1954 		goto drop;
1955 
1956 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
1957 drop:
1958 		kfree_skb(skb);
1959 	}
1960 	return 0;
1961 }
1962 #endif
1963 
1964 #ifdef CONFIG_IP_PIMSM_V2
1965 static int pim_rcv(struct sk_buff *skb)
1966 {
1967 	struct pimreghdr *pim;
1968 	struct net *net = dev_net(skb->dev);
1969 	struct mr_table *mrt;
1970 
1971 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
1972 		goto drop;
1973 
1974 	pim = (struct pimreghdr *)skb_transport_header(skb);
1975 	if (pim->type != ((PIM_VERSION << 4) | (PIM_REGISTER)) ||
1976 	    (pim->flags & PIM_NULL_REGISTER) ||
1977 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
1978 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
1979 		goto drop;
1980 
1981 	if (ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt) < 0)
1982 		goto drop;
1983 
1984 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
1985 drop:
1986 		kfree_skb(skb);
1987 	}
1988 	return 0;
1989 }
1990 #endif
1991 
1992 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
1993 			      struct mfc_cache *c, struct rtmsg *rtm)
1994 {
1995 	int ct;
1996 	struct rtnexthop *nhp;
1997 	u8 *b = skb_tail_pointer(skb);
1998 	struct rtattr *mp_head;
1999 
2000 	/* If cache is unresolved, don't try to parse IIF and OIF */
2001 	if (c->mfc_parent >= MAXVIFS)
2002 		return -ENOENT;
2003 
2004 	if (VIF_EXISTS(mrt, c->mfc_parent))
2005 		RTA_PUT(skb, RTA_IIF, 4, &mrt->vif_table[c->mfc_parent].dev->ifindex);
2006 
2007 	mp_head = (struct rtattr *)skb_put(skb, RTA_LENGTH(0));
2008 
2009 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
2010 		if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
2011 			if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
2012 				goto rtattr_failure;
2013 			nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
2014 			nhp->rtnh_flags = 0;
2015 			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
2016 			nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
2017 			nhp->rtnh_len = sizeof(*nhp);
2018 		}
2019 	}
2020 	mp_head->rta_type = RTA_MULTIPATH;
2021 	mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head;
2022 	rtm->rtm_type = RTN_MULTICAST;
2023 	return 1;
2024 
2025 rtattr_failure:
2026 	nlmsg_trim(skb, b);
2027 	return -EMSGSIZE;
2028 }
2029 
2030 int ipmr_get_route(struct net *net,
2031 		   struct sk_buff *skb, struct rtmsg *rtm, int nowait)
2032 {
2033 	int err;
2034 	struct mr_table *mrt;
2035 	struct mfc_cache *cache;
2036 	struct rtable *rt = skb_rtable(skb);
2037 
2038 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2039 	if (mrt == NULL)
2040 		return -ENOENT;
2041 
2042 	rcu_read_lock();
2043 	cache = ipmr_cache_find(mrt, rt->rt_src, rt->rt_dst);
2044 
2045 	if (cache == NULL) {
2046 		struct sk_buff *skb2;
2047 		struct iphdr *iph;
2048 		struct net_device *dev;
2049 		int vif = -1;
2050 
2051 		if (nowait) {
2052 			rcu_read_unlock();
2053 			return -EAGAIN;
2054 		}
2055 
2056 		dev = skb->dev;
2057 		read_lock(&mrt_lock);
2058 		if (dev)
2059 			vif = ipmr_find_vif(mrt, dev);
2060 		if (vif < 0) {
2061 			read_unlock(&mrt_lock);
2062 			rcu_read_unlock();
2063 			return -ENODEV;
2064 		}
2065 		skb2 = skb_clone(skb, GFP_ATOMIC);
2066 		if (!skb2) {
2067 			read_unlock(&mrt_lock);
2068 			rcu_read_unlock();
2069 			return -ENOMEM;
2070 		}
2071 
2072 		skb_push(skb2, sizeof(struct iphdr));
2073 		skb_reset_network_header(skb2);
2074 		iph = ip_hdr(skb2);
2075 		iph->ihl = sizeof(struct iphdr) >> 2;
2076 		iph->saddr = rt->rt_src;
2077 		iph->daddr = rt->rt_dst;
2078 		iph->version = 0;
2079 		err = ipmr_cache_unresolved(mrt, vif, skb2);
2080 		read_unlock(&mrt_lock);
2081 		rcu_read_unlock();
2082 		return err;
2083 	}
2084 
2085 	read_lock(&mrt_lock);
2086 	if (!nowait && (rtm->rtm_flags & RTM_F_NOTIFY))
2087 		cache->mfc_flags |= MFC_NOTIFY;
2088 	err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2089 	read_unlock(&mrt_lock);
2090 	rcu_read_unlock();
2091 	return err;
2092 }
2093 
2094 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2095 			    u32 pid, u32 seq, struct mfc_cache *c)
2096 {
2097 	struct nlmsghdr *nlh;
2098 	struct rtmsg *rtm;
2099 
2100 	nlh = nlmsg_put(skb, pid, seq, RTM_NEWROUTE, sizeof(*rtm), NLM_F_MULTI);
2101 	if (nlh == NULL)
2102 		return -EMSGSIZE;
2103 
2104 	rtm = nlmsg_data(nlh);
2105 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2106 	rtm->rtm_dst_len  = 32;
2107 	rtm->rtm_src_len  = 32;
2108 	rtm->rtm_tos      = 0;
2109 	rtm->rtm_table    = mrt->id;
2110 	NLA_PUT_U32(skb, RTA_TABLE, mrt->id);
2111 	rtm->rtm_type     = RTN_MULTICAST;
2112 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2113 	rtm->rtm_protocol = RTPROT_UNSPEC;
2114 	rtm->rtm_flags    = 0;
2115 
2116 	NLA_PUT_BE32(skb, RTA_SRC, c->mfc_origin);
2117 	NLA_PUT_BE32(skb, RTA_DST, c->mfc_mcastgrp);
2118 
2119 	if (__ipmr_fill_mroute(mrt, skb, c, rtm) < 0)
2120 		goto nla_put_failure;
2121 
2122 	return nlmsg_end(skb, nlh);
2123 
2124 nla_put_failure:
2125 	nlmsg_cancel(skb, nlh);
2126 	return -EMSGSIZE;
2127 }
2128 
2129 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2130 {
2131 	struct net *net = sock_net(skb->sk);
2132 	struct mr_table *mrt;
2133 	struct mfc_cache *mfc;
2134 	unsigned int t = 0, s_t;
2135 	unsigned int h = 0, s_h;
2136 	unsigned int e = 0, s_e;
2137 
2138 	s_t = cb->args[0];
2139 	s_h = cb->args[1];
2140 	s_e = cb->args[2];
2141 
2142 	rcu_read_lock();
2143 	ipmr_for_each_table(mrt, net) {
2144 		if (t < s_t)
2145 			goto next_table;
2146 		if (t > s_t)
2147 			s_h = 0;
2148 		for (h = s_h; h < MFC_LINES; h++) {
2149 			list_for_each_entry_rcu(mfc, &mrt->mfc_cache_array[h], list) {
2150 				if (e < s_e)
2151 					goto next_entry;
2152 				if (ipmr_fill_mroute(mrt, skb,
2153 						     NETLINK_CB(cb->skb).pid,
2154 						     cb->nlh->nlmsg_seq,
2155 						     mfc) < 0)
2156 					goto done;
2157 next_entry:
2158 				e++;
2159 			}
2160 			e = s_e = 0;
2161 		}
2162 		s_h = 0;
2163 next_table:
2164 		t++;
2165 	}
2166 done:
2167 	rcu_read_unlock();
2168 
2169 	cb->args[2] = e;
2170 	cb->args[1] = h;
2171 	cb->args[0] = t;
2172 
2173 	return skb->len;
2174 }
2175 
2176 #ifdef CONFIG_PROC_FS
2177 /*
2178  *	The /proc interfaces to multicast routing :
2179  *	/proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2180  */
2181 struct ipmr_vif_iter {
2182 	struct seq_net_private p;
2183 	struct mr_table *mrt;
2184 	int ct;
2185 };
2186 
2187 static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2188 					   struct ipmr_vif_iter *iter,
2189 					   loff_t pos)
2190 {
2191 	struct mr_table *mrt = iter->mrt;
2192 
2193 	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2194 		if (!VIF_EXISTS(mrt, iter->ct))
2195 			continue;
2196 		if (pos-- == 0)
2197 			return &mrt->vif_table[iter->ct];
2198 	}
2199 	return NULL;
2200 }
2201 
2202 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2203 	__acquires(mrt_lock)
2204 {
2205 	struct ipmr_vif_iter *iter = seq->private;
2206 	struct net *net = seq_file_net(seq);
2207 	struct mr_table *mrt;
2208 
2209 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2210 	if (mrt == NULL)
2211 		return ERR_PTR(-ENOENT);
2212 
2213 	iter->mrt = mrt;
2214 
2215 	read_lock(&mrt_lock);
2216 	return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2217 		: SEQ_START_TOKEN;
2218 }
2219 
2220 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2221 {
2222 	struct ipmr_vif_iter *iter = seq->private;
2223 	struct net *net = seq_file_net(seq);
2224 	struct mr_table *mrt = iter->mrt;
2225 
2226 	++*pos;
2227 	if (v == SEQ_START_TOKEN)
2228 		return ipmr_vif_seq_idx(net, iter, 0);
2229 
2230 	while (++iter->ct < mrt->maxvif) {
2231 		if (!VIF_EXISTS(mrt, iter->ct))
2232 			continue;
2233 		return &mrt->vif_table[iter->ct];
2234 	}
2235 	return NULL;
2236 }
2237 
2238 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2239 	__releases(mrt_lock)
2240 {
2241 	read_unlock(&mrt_lock);
2242 }
2243 
2244 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2245 {
2246 	struct ipmr_vif_iter *iter = seq->private;
2247 	struct mr_table *mrt = iter->mrt;
2248 
2249 	if (v == SEQ_START_TOKEN) {
2250 		seq_puts(seq,
2251 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2252 	} else {
2253 		const struct vif_device *vif = v;
2254 		const char *name =  vif->dev ? vif->dev->name : "none";
2255 
2256 		seq_printf(seq,
2257 			   "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2258 			   vif - mrt->vif_table,
2259 			   name, vif->bytes_in, vif->pkt_in,
2260 			   vif->bytes_out, vif->pkt_out,
2261 			   vif->flags, vif->local, vif->remote);
2262 	}
2263 	return 0;
2264 }
2265 
2266 static const struct seq_operations ipmr_vif_seq_ops = {
2267 	.start = ipmr_vif_seq_start,
2268 	.next  = ipmr_vif_seq_next,
2269 	.stop  = ipmr_vif_seq_stop,
2270 	.show  = ipmr_vif_seq_show,
2271 };
2272 
2273 static int ipmr_vif_open(struct inode *inode, struct file *file)
2274 {
2275 	return seq_open_net(inode, file, &ipmr_vif_seq_ops,
2276 			    sizeof(struct ipmr_vif_iter));
2277 }
2278 
2279 static const struct file_operations ipmr_vif_fops = {
2280 	.owner	 = THIS_MODULE,
2281 	.open    = ipmr_vif_open,
2282 	.read    = seq_read,
2283 	.llseek  = seq_lseek,
2284 	.release = seq_release_net,
2285 };
2286 
2287 struct ipmr_mfc_iter {
2288 	struct seq_net_private p;
2289 	struct mr_table *mrt;
2290 	struct list_head *cache;
2291 	int ct;
2292 };
2293 
2294 
2295 static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
2296 					  struct ipmr_mfc_iter *it, loff_t pos)
2297 {
2298 	struct mr_table *mrt = it->mrt;
2299 	struct mfc_cache *mfc;
2300 
2301 	rcu_read_lock();
2302 	for (it->ct = 0; it->ct < MFC_LINES; it->ct++) {
2303 		it->cache = &mrt->mfc_cache_array[it->ct];
2304 		list_for_each_entry_rcu(mfc, it->cache, list)
2305 			if (pos-- == 0)
2306 				return mfc;
2307 	}
2308 	rcu_read_unlock();
2309 
2310 	spin_lock_bh(&mfc_unres_lock);
2311 	it->cache = &mrt->mfc_unres_queue;
2312 	list_for_each_entry(mfc, it->cache, list)
2313 		if (pos-- == 0)
2314 			return mfc;
2315 	spin_unlock_bh(&mfc_unres_lock);
2316 
2317 	it->cache = NULL;
2318 	return NULL;
2319 }
2320 
2321 
2322 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2323 {
2324 	struct ipmr_mfc_iter *it = seq->private;
2325 	struct net *net = seq_file_net(seq);
2326 	struct mr_table *mrt;
2327 
2328 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2329 	if (mrt == NULL)
2330 		return ERR_PTR(-ENOENT);
2331 
2332 	it->mrt = mrt;
2333 	it->cache = NULL;
2334 	it->ct = 0;
2335 	return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
2336 		: SEQ_START_TOKEN;
2337 }
2338 
2339 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2340 {
2341 	struct mfc_cache *mfc = v;
2342 	struct ipmr_mfc_iter *it = seq->private;
2343 	struct net *net = seq_file_net(seq);
2344 	struct mr_table *mrt = it->mrt;
2345 
2346 	++*pos;
2347 
2348 	if (v == SEQ_START_TOKEN)
2349 		return ipmr_mfc_seq_idx(net, seq->private, 0);
2350 
2351 	if (mfc->list.next != it->cache)
2352 		return list_entry(mfc->list.next, struct mfc_cache, list);
2353 
2354 	if (it->cache == &mrt->mfc_unres_queue)
2355 		goto end_of_list;
2356 
2357 	BUG_ON(it->cache != &mrt->mfc_cache_array[it->ct]);
2358 
2359 	while (++it->ct < MFC_LINES) {
2360 		it->cache = &mrt->mfc_cache_array[it->ct];
2361 		if (list_empty(it->cache))
2362 			continue;
2363 		return list_first_entry(it->cache, struct mfc_cache, list);
2364 	}
2365 
2366 	/* exhausted cache_array, show unresolved */
2367 	rcu_read_unlock();
2368 	it->cache = &mrt->mfc_unres_queue;
2369 	it->ct = 0;
2370 
2371 	spin_lock_bh(&mfc_unres_lock);
2372 	if (!list_empty(it->cache))
2373 		return list_first_entry(it->cache, struct mfc_cache, list);
2374 
2375 end_of_list:
2376 	spin_unlock_bh(&mfc_unres_lock);
2377 	it->cache = NULL;
2378 
2379 	return NULL;
2380 }
2381 
2382 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
2383 {
2384 	struct ipmr_mfc_iter *it = seq->private;
2385 	struct mr_table *mrt = it->mrt;
2386 
2387 	if (it->cache == &mrt->mfc_unres_queue)
2388 		spin_unlock_bh(&mfc_unres_lock);
2389 	else if (it->cache == &mrt->mfc_cache_array[it->ct])
2390 		rcu_read_unlock();
2391 }
2392 
2393 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2394 {
2395 	int n;
2396 
2397 	if (v == SEQ_START_TOKEN) {
2398 		seq_puts(seq,
2399 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2400 	} else {
2401 		const struct mfc_cache *mfc = v;
2402 		const struct ipmr_mfc_iter *it = seq->private;
2403 		const struct mr_table *mrt = it->mrt;
2404 
2405 		seq_printf(seq, "%08X %08X %-3hd",
2406 			   (__force u32) mfc->mfc_mcastgrp,
2407 			   (__force u32) mfc->mfc_origin,
2408 			   mfc->mfc_parent);
2409 
2410 		if (it->cache != &mrt->mfc_unres_queue) {
2411 			seq_printf(seq, " %8lu %8lu %8lu",
2412 				   mfc->mfc_un.res.pkt,
2413 				   mfc->mfc_un.res.bytes,
2414 				   mfc->mfc_un.res.wrong_if);
2415 			for (n = mfc->mfc_un.res.minvif;
2416 			     n < mfc->mfc_un.res.maxvif; n++) {
2417 				if (VIF_EXISTS(mrt, n) &&
2418 				    mfc->mfc_un.res.ttls[n] < 255)
2419 					seq_printf(seq,
2420 					   " %2d:%-3d",
2421 					   n, mfc->mfc_un.res.ttls[n]);
2422 			}
2423 		} else {
2424 			/* unresolved mfc_caches don't contain
2425 			 * pkt, bytes and wrong_if values
2426 			 */
2427 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
2428 		}
2429 		seq_putc(seq, '\n');
2430 	}
2431 	return 0;
2432 }
2433 
2434 static const struct seq_operations ipmr_mfc_seq_ops = {
2435 	.start = ipmr_mfc_seq_start,
2436 	.next  = ipmr_mfc_seq_next,
2437 	.stop  = ipmr_mfc_seq_stop,
2438 	.show  = ipmr_mfc_seq_show,
2439 };
2440 
2441 static int ipmr_mfc_open(struct inode *inode, struct file *file)
2442 {
2443 	return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
2444 			    sizeof(struct ipmr_mfc_iter));
2445 }
2446 
2447 static const struct file_operations ipmr_mfc_fops = {
2448 	.owner	 = THIS_MODULE,
2449 	.open    = ipmr_mfc_open,
2450 	.read    = seq_read,
2451 	.llseek  = seq_lseek,
2452 	.release = seq_release_net,
2453 };
2454 #endif
2455 
2456 #ifdef CONFIG_IP_PIMSM_V2
2457 static const struct net_protocol pim_protocol = {
2458 	.handler	=	pim_rcv,
2459 	.netns_ok	=	1,
2460 };
2461 #endif
2462 
2463 
2464 /*
2465  *	Setup for IP multicast routing
2466  */
2467 static int __net_init ipmr_net_init(struct net *net)
2468 {
2469 	int err;
2470 
2471 	err = ipmr_rules_init(net);
2472 	if (err < 0)
2473 		goto fail;
2474 
2475 #ifdef CONFIG_PROC_FS
2476 	err = -ENOMEM;
2477 	if (!proc_net_fops_create(net, "ip_mr_vif", 0, &ipmr_vif_fops))
2478 		goto proc_vif_fail;
2479 	if (!proc_net_fops_create(net, "ip_mr_cache", 0, &ipmr_mfc_fops))
2480 		goto proc_cache_fail;
2481 #endif
2482 	return 0;
2483 
2484 #ifdef CONFIG_PROC_FS
2485 proc_cache_fail:
2486 	proc_net_remove(net, "ip_mr_vif");
2487 proc_vif_fail:
2488 	ipmr_rules_exit(net);
2489 #endif
2490 fail:
2491 	return err;
2492 }
2493 
2494 static void __net_exit ipmr_net_exit(struct net *net)
2495 {
2496 #ifdef CONFIG_PROC_FS
2497 	proc_net_remove(net, "ip_mr_cache");
2498 	proc_net_remove(net, "ip_mr_vif");
2499 #endif
2500 	ipmr_rules_exit(net);
2501 }
2502 
2503 static struct pernet_operations ipmr_net_ops = {
2504 	.init = ipmr_net_init,
2505 	.exit = ipmr_net_exit,
2506 };
2507 
2508 int __init ip_mr_init(void)
2509 {
2510 	int err;
2511 
2512 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
2513 				       sizeof(struct mfc_cache),
2514 				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
2515 				       NULL);
2516 	if (!mrt_cachep)
2517 		return -ENOMEM;
2518 
2519 	err = register_pernet_subsys(&ipmr_net_ops);
2520 	if (err)
2521 		goto reg_pernet_fail;
2522 
2523 	err = register_netdevice_notifier(&ip_mr_notifier);
2524 	if (err)
2525 		goto reg_notif_fail;
2526 #ifdef CONFIG_IP_PIMSM_V2
2527 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
2528 		printk(KERN_ERR "ip_mr_init: can't add PIM protocol\n");
2529 		err = -EAGAIN;
2530 		goto add_proto_fail;
2531 	}
2532 #endif
2533 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE, NULL, ipmr_rtm_dumproute);
2534 	return 0;
2535 
2536 #ifdef CONFIG_IP_PIMSM_V2
2537 add_proto_fail:
2538 	unregister_netdevice_notifier(&ip_mr_notifier);
2539 #endif
2540 reg_notif_fail:
2541 	unregister_pernet_subsys(&ipmr_net_ops);
2542 reg_pernet_fail:
2543 	kmem_cache_destroy(mrt_cachep);
2544 	return err;
2545 }
2546