xref: /linux/net/ipv4/ipmr.c (revision cc3ae7b0af27118994c1e491382b253be3b762bf)
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 #include <net/nexthop.h>
70 
71 struct ipmr_rule {
72 	struct fib_rule		common;
73 };
74 
75 struct ipmr_result {
76 	struct mr_table		*mrt;
77 };
78 
79 /* Big lock, protecting vif table, mrt cache and mroute socket state.
80  * Note that the changes are semaphored via rtnl_lock.
81  */
82 
83 static DEFINE_RWLOCK(mrt_lock);
84 
85 /* Multicast router control variables */
86 
87 /* Special spinlock for queue of unresolved entries */
88 static DEFINE_SPINLOCK(mfc_unres_lock);
89 
90 /* We return to original Alan's scheme. Hash table of resolved
91  * entries is changed only in process context and protected
92  * with weak lock mrt_lock. Queue of unresolved entries is protected
93  * with strong spinlock mfc_unres_lock.
94  *
95  * In this case data path is free of exclusive locks at all.
96  */
97 
98 static struct kmem_cache *mrt_cachep __read_mostly;
99 
100 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
101 static void ipmr_free_table(struct mr_table *mrt);
102 
103 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
104 			  struct sk_buff *skb, struct mfc_cache *cache,
105 			  int local);
106 static int ipmr_cache_report(struct mr_table *mrt,
107 			     struct sk_buff *pkt, vifi_t vifi, int assert);
108 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
109 			      struct mfc_cache *c, struct rtmsg *rtm);
110 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
111 				 int cmd);
112 static void mroute_clean_tables(struct mr_table *mrt, bool all);
113 static void ipmr_expire_process(unsigned long arg);
114 
115 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
116 #define ipmr_for_each_table(mrt, net) \
117 	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
118 
119 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
120 {
121 	struct mr_table *mrt;
122 
123 	ipmr_for_each_table(mrt, net) {
124 		if (mrt->id == id)
125 			return mrt;
126 	}
127 	return NULL;
128 }
129 
130 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
131 			   struct mr_table **mrt)
132 {
133 	int err;
134 	struct ipmr_result res;
135 	struct fib_lookup_arg arg = {
136 		.result = &res,
137 		.flags = FIB_LOOKUP_NOREF,
138 	};
139 
140 	err = fib_rules_lookup(net->ipv4.mr_rules_ops,
141 			       flowi4_to_flowi(flp4), 0, &arg);
142 	if (err < 0)
143 		return err;
144 	*mrt = res.mrt;
145 	return 0;
146 }
147 
148 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
149 			    int flags, struct fib_lookup_arg *arg)
150 {
151 	struct ipmr_result *res = arg->result;
152 	struct mr_table *mrt;
153 
154 	switch (rule->action) {
155 	case FR_ACT_TO_TBL:
156 		break;
157 	case FR_ACT_UNREACHABLE:
158 		return -ENETUNREACH;
159 	case FR_ACT_PROHIBIT:
160 		return -EACCES;
161 	case FR_ACT_BLACKHOLE:
162 	default:
163 		return -EINVAL;
164 	}
165 
166 	mrt = ipmr_get_table(rule->fr_net, rule->table);
167 	if (!mrt)
168 		return -EAGAIN;
169 	res->mrt = mrt;
170 	return 0;
171 }
172 
173 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
174 {
175 	return 1;
176 }
177 
178 static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
179 	FRA_GENERIC_POLICY,
180 };
181 
182 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
183 			       struct fib_rule_hdr *frh, struct nlattr **tb)
184 {
185 	return 0;
186 }
187 
188 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
189 			     struct nlattr **tb)
190 {
191 	return 1;
192 }
193 
194 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
195 			  struct fib_rule_hdr *frh)
196 {
197 	frh->dst_len = 0;
198 	frh->src_len = 0;
199 	frh->tos     = 0;
200 	return 0;
201 }
202 
203 static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
204 	.family		= RTNL_FAMILY_IPMR,
205 	.rule_size	= sizeof(struct ipmr_rule),
206 	.addr_size	= sizeof(u32),
207 	.action		= ipmr_rule_action,
208 	.match		= ipmr_rule_match,
209 	.configure	= ipmr_rule_configure,
210 	.compare	= ipmr_rule_compare,
211 	.fill		= ipmr_rule_fill,
212 	.nlgroup	= RTNLGRP_IPV4_RULE,
213 	.policy		= ipmr_rule_policy,
214 	.owner		= THIS_MODULE,
215 };
216 
217 static int __net_init ipmr_rules_init(struct net *net)
218 {
219 	struct fib_rules_ops *ops;
220 	struct mr_table *mrt;
221 	int err;
222 
223 	ops = fib_rules_register(&ipmr_rules_ops_template, net);
224 	if (IS_ERR(ops))
225 		return PTR_ERR(ops);
226 
227 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
228 
229 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
230 	if (IS_ERR(mrt)) {
231 		err = PTR_ERR(mrt);
232 		goto err1;
233 	}
234 
235 	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
236 	if (err < 0)
237 		goto err2;
238 
239 	net->ipv4.mr_rules_ops = ops;
240 	return 0;
241 
242 err2:
243 	ipmr_free_table(mrt);
244 err1:
245 	fib_rules_unregister(ops);
246 	return err;
247 }
248 
249 static void __net_exit ipmr_rules_exit(struct net *net)
250 {
251 	struct mr_table *mrt, *next;
252 
253 	rtnl_lock();
254 	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
255 		list_del(&mrt->list);
256 		ipmr_free_table(mrt);
257 	}
258 	fib_rules_unregister(net->ipv4.mr_rules_ops);
259 	rtnl_unlock();
260 }
261 #else
262 #define ipmr_for_each_table(mrt, net) \
263 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
264 
265 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
266 {
267 	return net->ipv4.mrt;
268 }
269 
270 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
271 			   struct mr_table **mrt)
272 {
273 	*mrt = net->ipv4.mrt;
274 	return 0;
275 }
276 
277 static int __net_init ipmr_rules_init(struct net *net)
278 {
279 	struct mr_table *mrt;
280 
281 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
282 	if (IS_ERR(mrt))
283 		return PTR_ERR(mrt);
284 	net->ipv4.mrt = mrt;
285 	return 0;
286 }
287 
288 static void __net_exit ipmr_rules_exit(struct net *net)
289 {
290 	rtnl_lock();
291 	ipmr_free_table(net->ipv4.mrt);
292 	net->ipv4.mrt = NULL;
293 	rtnl_unlock();
294 }
295 #endif
296 
297 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
298 {
299 	struct mr_table *mrt;
300 	unsigned int i;
301 
302 	/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
303 	if (id != RT_TABLE_DEFAULT && id >= 1000000000)
304 		return ERR_PTR(-EINVAL);
305 
306 	mrt = ipmr_get_table(net, id);
307 	if (mrt)
308 		return mrt;
309 
310 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
311 	if (!mrt)
312 		return ERR_PTR(-ENOMEM);
313 	write_pnet(&mrt->net, net);
314 	mrt->id = id;
315 
316 	/* Forwarding cache */
317 	for (i = 0; i < MFC_LINES; i++)
318 		INIT_LIST_HEAD(&mrt->mfc_cache_array[i]);
319 
320 	INIT_LIST_HEAD(&mrt->mfc_unres_queue);
321 
322 	setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
323 		    (unsigned long)mrt);
324 
325 	mrt->mroute_reg_vif_num = -1;
326 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
327 	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
328 #endif
329 	return mrt;
330 }
331 
332 static void ipmr_free_table(struct mr_table *mrt)
333 {
334 	del_timer_sync(&mrt->ipmr_expire_timer);
335 	mroute_clean_tables(mrt, true);
336 	kfree(mrt);
337 }
338 
339 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
340 
341 static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
342 {
343 	struct net *net = dev_net(dev);
344 
345 	dev_close(dev);
346 
347 	dev = __dev_get_by_name(net, "tunl0");
348 	if (dev) {
349 		const struct net_device_ops *ops = dev->netdev_ops;
350 		struct ifreq ifr;
351 		struct ip_tunnel_parm p;
352 
353 		memset(&p, 0, sizeof(p));
354 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
355 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
356 		p.iph.version = 4;
357 		p.iph.ihl = 5;
358 		p.iph.protocol = IPPROTO_IPIP;
359 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
360 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
361 
362 		if (ops->ndo_do_ioctl) {
363 			mm_segment_t oldfs = get_fs();
364 
365 			set_fs(KERNEL_DS);
366 			ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
367 			set_fs(oldfs);
368 		}
369 	}
370 }
371 
372 /* Initialize ipmr pimreg/tunnel in_device */
373 static bool ipmr_init_vif_indev(const struct net_device *dev)
374 {
375 	struct in_device *in_dev;
376 
377 	ASSERT_RTNL();
378 
379 	in_dev = __in_dev_get_rtnl(dev);
380 	if (!in_dev)
381 		return false;
382 	ipv4_devconf_setall(in_dev);
383 	neigh_parms_data_state_setall(in_dev->arp_parms);
384 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
385 
386 	return true;
387 }
388 
389 static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
390 {
391 	struct net_device  *dev;
392 
393 	dev = __dev_get_by_name(net, "tunl0");
394 
395 	if (dev) {
396 		const struct net_device_ops *ops = dev->netdev_ops;
397 		int err;
398 		struct ifreq ifr;
399 		struct ip_tunnel_parm p;
400 
401 		memset(&p, 0, sizeof(p));
402 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
403 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
404 		p.iph.version = 4;
405 		p.iph.ihl = 5;
406 		p.iph.protocol = IPPROTO_IPIP;
407 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
408 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
409 
410 		if (ops->ndo_do_ioctl) {
411 			mm_segment_t oldfs = get_fs();
412 
413 			set_fs(KERNEL_DS);
414 			err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
415 			set_fs(oldfs);
416 		} else {
417 			err = -EOPNOTSUPP;
418 		}
419 		dev = NULL;
420 
421 		if (err == 0 &&
422 		    (dev = __dev_get_by_name(net, p.name)) != NULL) {
423 			dev->flags |= IFF_MULTICAST;
424 			if (!ipmr_init_vif_indev(dev))
425 				goto failure;
426 			if (dev_open(dev))
427 				goto failure;
428 			dev_hold(dev);
429 		}
430 	}
431 	return dev;
432 
433 failure:
434 	unregister_netdevice(dev);
435 	return NULL;
436 }
437 
438 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
439 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
440 {
441 	struct net *net = dev_net(dev);
442 	struct mr_table *mrt;
443 	struct flowi4 fl4 = {
444 		.flowi4_oif	= dev->ifindex,
445 		.flowi4_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
446 		.flowi4_mark	= skb->mark,
447 	};
448 	int err;
449 
450 	err = ipmr_fib_lookup(net, &fl4, &mrt);
451 	if (err < 0) {
452 		kfree_skb(skb);
453 		return err;
454 	}
455 
456 	read_lock(&mrt_lock);
457 	dev->stats.tx_bytes += skb->len;
458 	dev->stats.tx_packets++;
459 	ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
460 	read_unlock(&mrt_lock);
461 	kfree_skb(skb);
462 	return NETDEV_TX_OK;
463 }
464 
465 static int reg_vif_get_iflink(const struct net_device *dev)
466 {
467 	return 0;
468 }
469 
470 static const struct net_device_ops reg_vif_netdev_ops = {
471 	.ndo_start_xmit	= reg_vif_xmit,
472 	.ndo_get_iflink = reg_vif_get_iflink,
473 };
474 
475 static void reg_vif_setup(struct net_device *dev)
476 {
477 	dev->type		= ARPHRD_PIMREG;
478 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
479 	dev->flags		= IFF_NOARP;
480 	dev->netdev_ops		= &reg_vif_netdev_ops;
481 	dev->destructor		= free_netdev;
482 	dev->features		|= NETIF_F_NETNS_LOCAL;
483 }
484 
485 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
486 {
487 	struct net_device *dev;
488 	char name[IFNAMSIZ];
489 
490 	if (mrt->id == RT_TABLE_DEFAULT)
491 		sprintf(name, "pimreg");
492 	else
493 		sprintf(name, "pimreg%u", mrt->id);
494 
495 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
496 
497 	if (!dev)
498 		return NULL;
499 
500 	dev_net_set(dev, net);
501 
502 	if (register_netdevice(dev)) {
503 		free_netdev(dev);
504 		return NULL;
505 	}
506 
507 	if (!ipmr_init_vif_indev(dev))
508 		goto failure;
509 	if (dev_open(dev))
510 		goto failure;
511 
512 	dev_hold(dev);
513 
514 	return dev;
515 
516 failure:
517 	unregister_netdevice(dev);
518 	return NULL;
519 }
520 
521 /* called with rcu_read_lock() */
522 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
523 		     unsigned int pimlen)
524 {
525 	struct net_device *reg_dev = NULL;
526 	struct iphdr *encap;
527 
528 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
529 	/* Check that:
530 	 * a. packet is really sent to a multicast group
531 	 * b. packet is not a NULL-REGISTER
532 	 * c. packet is not truncated
533 	 */
534 	if (!ipv4_is_multicast(encap->daddr) ||
535 	    encap->tot_len == 0 ||
536 	    ntohs(encap->tot_len) + pimlen > skb->len)
537 		return 1;
538 
539 	read_lock(&mrt_lock);
540 	if (mrt->mroute_reg_vif_num >= 0)
541 		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
542 	read_unlock(&mrt_lock);
543 
544 	if (!reg_dev)
545 		return 1;
546 
547 	skb->mac_header = skb->network_header;
548 	skb_pull(skb, (u8 *)encap - skb->data);
549 	skb_reset_network_header(skb);
550 	skb->protocol = htons(ETH_P_IP);
551 	skb->ip_summed = CHECKSUM_NONE;
552 
553 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
554 
555 	netif_rx(skb);
556 
557 	return NET_RX_SUCCESS;
558 }
559 #else
560 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
561 {
562 	return NULL;
563 }
564 #endif
565 
566 /**
567  *	vif_delete - Delete a VIF entry
568  *	@notify: Set to 1, if the caller is a notifier_call
569  */
570 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
571 		      struct list_head *head)
572 {
573 	struct vif_device *v;
574 	struct net_device *dev;
575 	struct in_device *in_dev;
576 
577 	if (vifi < 0 || vifi >= mrt->maxvif)
578 		return -EADDRNOTAVAIL;
579 
580 	v = &mrt->vif_table[vifi];
581 
582 	write_lock_bh(&mrt_lock);
583 	dev = v->dev;
584 	v->dev = NULL;
585 
586 	if (!dev) {
587 		write_unlock_bh(&mrt_lock);
588 		return -EADDRNOTAVAIL;
589 	}
590 
591 	if (vifi == mrt->mroute_reg_vif_num)
592 		mrt->mroute_reg_vif_num = -1;
593 
594 	if (vifi + 1 == mrt->maxvif) {
595 		int tmp;
596 
597 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
598 			if (VIF_EXISTS(mrt, tmp))
599 				break;
600 		}
601 		mrt->maxvif = tmp+1;
602 	}
603 
604 	write_unlock_bh(&mrt_lock);
605 
606 	dev_set_allmulti(dev, -1);
607 
608 	in_dev = __in_dev_get_rtnl(dev);
609 	if (in_dev) {
610 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
611 		inet_netconf_notify_devconf(dev_net(dev),
612 					    NETCONFA_MC_FORWARDING,
613 					    dev->ifindex, &in_dev->cnf);
614 		ip_rt_multicast_event(in_dev);
615 	}
616 
617 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
618 		unregister_netdevice_queue(dev, head);
619 
620 	dev_put(dev);
621 	return 0;
622 }
623 
624 static void ipmr_cache_free_rcu(struct rcu_head *head)
625 {
626 	struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
627 
628 	kmem_cache_free(mrt_cachep, c);
629 }
630 
631 static inline void ipmr_cache_free(struct mfc_cache *c)
632 {
633 	call_rcu(&c->rcu, ipmr_cache_free_rcu);
634 }
635 
636 /* Destroy an unresolved cache entry, killing queued skbs
637  * and reporting error to netlink readers.
638  */
639 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
640 {
641 	struct net *net = read_pnet(&mrt->net);
642 	struct sk_buff *skb;
643 	struct nlmsgerr *e;
644 
645 	atomic_dec(&mrt->cache_resolve_queue_len);
646 
647 	while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
648 		if (ip_hdr(skb)->version == 0) {
649 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
650 			nlh->nlmsg_type = NLMSG_ERROR;
651 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
652 			skb_trim(skb, nlh->nlmsg_len);
653 			e = nlmsg_data(nlh);
654 			e->error = -ETIMEDOUT;
655 			memset(&e->msg, 0, sizeof(e->msg));
656 
657 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
658 		} else {
659 			kfree_skb(skb);
660 		}
661 	}
662 
663 	ipmr_cache_free(c);
664 }
665 
666 /* Timer process for the unresolved queue. */
667 static void ipmr_expire_process(unsigned long arg)
668 {
669 	struct mr_table *mrt = (struct mr_table *)arg;
670 	unsigned long now;
671 	unsigned long expires;
672 	struct mfc_cache *c, *next;
673 
674 	if (!spin_trylock(&mfc_unres_lock)) {
675 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
676 		return;
677 	}
678 
679 	if (list_empty(&mrt->mfc_unres_queue))
680 		goto out;
681 
682 	now = jiffies;
683 	expires = 10*HZ;
684 
685 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
686 		if (time_after(c->mfc_un.unres.expires, now)) {
687 			unsigned long interval = c->mfc_un.unres.expires - now;
688 			if (interval < expires)
689 				expires = interval;
690 			continue;
691 		}
692 
693 		list_del(&c->list);
694 		mroute_netlink_event(mrt, c, RTM_DELROUTE);
695 		ipmr_destroy_unres(mrt, c);
696 	}
697 
698 	if (!list_empty(&mrt->mfc_unres_queue))
699 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
700 
701 out:
702 	spin_unlock(&mfc_unres_lock);
703 }
704 
705 /* Fill oifs list. It is called under write locked mrt_lock. */
706 static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
707 				   unsigned char *ttls)
708 {
709 	int vifi;
710 
711 	cache->mfc_un.res.minvif = MAXVIFS;
712 	cache->mfc_un.res.maxvif = 0;
713 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
714 
715 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
716 		if (VIF_EXISTS(mrt, vifi) &&
717 		    ttls[vifi] && ttls[vifi] < 255) {
718 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
719 			if (cache->mfc_un.res.minvif > vifi)
720 				cache->mfc_un.res.minvif = vifi;
721 			if (cache->mfc_un.res.maxvif <= vifi)
722 				cache->mfc_un.res.maxvif = vifi + 1;
723 		}
724 	}
725 }
726 
727 static int vif_add(struct net *net, struct mr_table *mrt,
728 		   struct vifctl *vifc, int mrtsock)
729 {
730 	int vifi = vifc->vifc_vifi;
731 	struct vif_device *v = &mrt->vif_table[vifi];
732 	struct net_device *dev;
733 	struct in_device *in_dev;
734 	int err;
735 
736 	/* Is vif busy ? */
737 	if (VIF_EXISTS(mrt, vifi))
738 		return -EADDRINUSE;
739 
740 	switch (vifc->vifc_flags) {
741 	case VIFF_REGISTER:
742 		if (!ipmr_pimsm_enabled())
743 			return -EINVAL;
744 		/* Special Purpose VIF in PIM
745 		 * All the packets will be sent to the daemon
746 		 */
747 		if (mrt->mroute_reg_vif_num >= 0)
748 			return -EADDRINUSE;
749 		dev = ipmr_reg_vif(net, mrt);
750 		if (!dev)
751 			return -ENOBUFS;
752 		err = dev_set_allmulti(dev, 1);
753 		if (err) {
754 			unregister_netdevice(dev);
755 			dev_put(dev);
756 			return err;
757 		}
758 		break;
759 	case VIFF_TUNNEL:
760 		dev = ipmr_new_tunnel(net, vifc);
761 		if (!dev)
762 			return -ENOBUFS;
763 		err = dev_set_allmulti(dev, 1);
764 		if (err) {
765 			ipmr_del_tunnel(dev, vifc);
766 			dev_put(dev);
767 			return err;
768 		}
769 		break;
770 	case VIFF_USE_IFINDEX:
771 	case 0:
772 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
773 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
774 			if (dev && !__in_dev_get_rtnl(dev)) {
775 				dev_put(dev);
776 				return -EADDRNOTAVAIL;
777 			}
778 		} else {
779 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
780 		}
781 		if (!dev)
782 			return -EADDRNOTAVAIL;
783 		err = dev_set_allmulti(dev, 1);
784 		if (err) {
785 			dev_put(dev);
786 			return err;
787 		}
788 		break;
789 	default:
790 		return -EINVAL;
791 	}
792 
793 	in_dev = __in_dev_get_rtnl(dev);
794 	if (!in_dev) {
795 		dev_put(dev);
796 		return -EADDRNOTAVAIL;
797 	}
798 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
799 	inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING, dev->ifindex,
800 				    &in_dev->cnf);
801 	ip_rt_multicast_event(in_dev);
802 
803 	/* Fill in the VIF structures */
804 
805 	v->rate_limit = vifc->vifc_rate_limit;
806 	v->local = vifc->vifc_lcl_addr.s_addr;
807 	v->remote = vifc->vifc_rmt_addr.s_addr;
808 	v->flags = vifc->vifc_flags;
809 	if (!mrtsock)
810 		v->flags |= VIFF_STATIC;
811 	v->threshold = vifc->vifc_threshold;
812 	v->bytes_in = 0;
813 	v->bytes_out = 0;
814 	v->pkt_in = 0;
815 	v->pkt_out = 0;
816 	v->link = dev->ifindex;
817 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
818 		v->link = dev_get_iflink(dev);
819 
820 	/* And finish update writing critical data */
821 	write_lock_bh(&mrt_lock);
822 	v->dev = dev;
823 	if (v->flags & VIFF_REGISTER)
824 		mrt->mroute_reg_vif_num = vifi;
825 	if (vifi+1 > mrt->maxvif)
826 		mrt->maxvif = vifi+1;
827 	write_unlock_bh(&mrt_lock);
828 	return 0;
829 }
830 
831 /* called with rcu_read_lock() */
832 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
833 					 __be32 origin,
834 					 __be32 mcastgrp)
835 {
836 	int line = MFC_HASH(mcastgrp, origin);
837 	struct mfc_cache *c;
838 
839 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list) {
840 		if (c->mfc_origin == origin && c->mfc_mcastgrp == mcastgrp)
841 			return c;
842 	}
843 	return NULL;
844 }
845 
846 /* Look for a (*,*,oif) entry */
847 static struct mfc_cache *ipmr_cache_find_any_parent(struct mr_table *mrt,
848 						    int vifi)
849 {
850 	int line = MFC_HASH(htonl(INADDR_ANY), htonl(INADDR_ANY));
851 	struct mfc_cache *c;
852 
853 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list)
854 		if (c->mfc_origin == htonl(INADDR_ANY) &&
855 		    c->mfc_mcastgrp == htonl(INADDR_ANY) &&
856 		    c->mfc_un.res.ttls[vifi] < 255)
857 			return c;
858 
859 	return NULL;
860 }
861 
862 /* Look for a (*,G) entry */
863 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
864 					     __be32 mcastgrp, int vifi)
865 {
866 	int line = MFC_HASH(mcastgrp, htonl(INADDR_ANY));
867 	struct mfc_cache *c, *proxy;
868 
869 	if (mcastgrp == htonl(INADDR_ANY))
870 		goto skip;
871 
872 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list)
873 		if (c->mfc_origin == htonl(INADDR_ANY) &&
874 		    c->mfc_mcastgrp == mcastgrp) {
875 			if (c->mfc_un.res.ttls[vifi] < 255)
876 				return c;
877 
878 			/* It's ok if the vifi is part of the static tree */
879 			proxy = ipmr_cache_find_any_parent(mrt,
880 							   c->mfc_parent);
881 			if (proxy && proxy->mfc_un.res.ttls[vifi] < 255)
882 				return c;
883 		}
884 
885 skip:
886 	return ipmr_cache_find_any_parent(mrt, vifi);
887 }
888 
889 /* Allocate a multicast cache entry */
890 static struct mfc_cache *ipmr_cache_alloc(void)
891 {
892 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
893 
894 	if (c) {
895 		c->mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
896 		c->mfc_un.res.minvif = MAXVIFS;
897 	}
898 	return c;
899 }
900 
901 static struct mfc_cache *ipmr_cache_alloc_unres(void)
902 {
903 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
904 
905 	if (c) {
906 		skb_queue_head_init(&c->mfc_un.unres.unresolved);
907 		c->mfc_un.unres.expires = jiffies + 10*HZ;
908 	}
909 	return c;
910 }
911 
912 /* A cache entry has gone into a resolved state from queued */
913 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
914 			       struct mfc_cache *uc, struct mfc_cache *c)
915 {
916 	struct sk_buff *skb;
917 	struct nlmsgerr *e;
918 
919 	/* Play the pending entries through our router */
920 	while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
921 		if (ip_hdr(skb)->version == 0) {
922 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
923 
924 			if (__ipmr_fill_mroute(mrt, skb, c, nlmsg_data(nlh)) > 0) {
925 				nlh->nlmsg_len = skb_tail_pointer(skb) -
926 						 (u8 *)nlh;
927 			} else {
928 				nlh->nlmsg_type = NLMSG_ERROR;
929 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
930 				skb_trim(skb, nlh->nlmsg_len);
931 				e = nlmsg_data(nlh);
932 				e->error = -EMSGSIZE;
933 				memset(&e->msg, 0, sizeof(e->msg));
934 			}
935 
936 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
937 		} else {
938 			ip_mr_forward(net, mrt, skb, c, 0);
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 static int ipmr_cache_report(struct mr_table *mrt,
949 			     struct sk_buff *pkt, vifi_t vifi, int assert)
950 {
951 	const int ihl = ip_hdrlen(pkt);
952 	struct sock *mroute_sk;
953 	struct igmphdr *igmp;
954 	struct igmpmsg *msg;
955 	struct sk_buff *skb;
956 	int ret;
957 
958 	if (assert == IGMPMSG_WHOLEPKT)
959 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
960 	else
961 		skb = alloc_skb(128, GFP_ATOMIC);
962 
963 	if (!skb)
964 		return -ENOBUFS;
965 
966 	if (assert == IGMPMSG_WHOLEPKT) {
967 		/* Ugly, but we have no choice with this interface.
968 		 * Duplicate old header, fix ihl, length etc.
969 		 * And all this only to mangle msg->im_msgtype and
970 		 * to set msg->im_mbz to "mbz" :-)
971 		 */
972 		skb_push(skb, sizeof(struct iphdr));
973 		skb_reset_network_header(skb);
974 		skb_reset_transport_header(skb);
975 		msg = (struct igmpmsg *)skb_network_header(skb);
976 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
977 		msg->im_msgtype = IGMPMSG_WHOLEPKT;
978 		msg->im_mbz = 0;
979 		msg->im_vif = mrt->mroute_reg_vif_num;
980 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
981 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
982 					     sizeof(struct iphdr));
983 	} else {
984 		/* Copy the IP header */
985 		skb_set_network_header(skb, skb->len);
986 		skb_put(skb, ihl);
987 		skb_copy_to_linear_data(skb, pkt->data, ihl);
988 		/* Flag to the kernel this is a route add */
989 		ip_hdr(skb)->protocol = 0;
990 		msg = (struct igmpmsg *)skb_network_header(skb);
991 		msg->im_vif = vifi;
992 		skb_dst_set(skb, dst_clone(skb_dst(pkt)));
993 		/* Add our header */
994 		igmp = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
995 		igmp->type = assert;
996 		msg->im_msgtype = assert;
997 		igmp->code = 0;
998 		ip_hdr(skb)->tot_len = htons(skb->len);	/* Fix the length */
999 		skb->transport_header = skb->network_header;
1000 	}
1001 
1002 	rcu_read_lock();
1003 	mroute_sk = rcu_dereference(mrt->mroute_sk);
1004 	if (!mroute_sk) {
1005 		rcu_read_unlock();
1006 		kfree_skb(skb);
1007 		return -EINVAL;
1008 	}
1009 
1010 	/* Deliver to mrouted */
1011 	ret = sock_queue_rcv_skb(mroute_sk, skb);
1012 	rcu_read_unlock();
1013 	if (ret < 0) {
1014 		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1015 		kfree_skb(skb);
1016 	}
1017 
1018 	return ret;
1019 }
1020 
1021 /* Queue a packet for resolution. It gets locked cache entry! */
1022 static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
1023 				 struct sk_buff *skb)
1024 {
1025 	bool found = false;
1026 	int err;
1027 	struct mfc_cache *c;
1028 	const struct iphdr *iph = ip_hdr(skb);
1029 
1030 	spin_lock_bh(&mfc_unres_lock);
1031 	list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
1032 		if (c->mfc_mcastgrp == iph->daddr &&
1033 		    c->mfc_origin == iph->saddr) {
1034 			found = true;
1035 			break;
1036 		}
1037 	}
1038 
1039 	if (!found) {
1040 		/* Create a new entry if allowable */
1041 		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
1042 		    (c = ipmr_cache_alloc_unres()) == NULL) {
1043 			spin_unlock_bh(&mfc_unres_lock);
1044 
1045 			kfree_skb(skb);
1046 			return -ENOBUFS;
1047 		}
1048 
1049 		/* Fill in the new cache entry */
1050 		c->mfc_parent	= -1;
1051 		c->mfc_origin	= iph->saddr;
1052 		c->mfc_mcastgrp	= iph->daddr;
1053 
1054 		/* Reflect first query at mrouted. */
1055 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1056 		if (err < 0) {
1057 			/* If the report failed throw the cache entry
1058 			   out - Brad Parker
1059 			 */
1060 			spin_unlock_bh(&mfc_unres_lock);
1061 
1062 			ipmr_cache_free(c);
1063 			kfree_skb(skb);
1064 			return err;
1065 		}
1066 
1067 		atomic_inc(&mrt->cache_resolve_queue_len);
1068 		list_add(&c->list, &mrt->mfc_unres_queue);
1069 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1070 
1071 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1072 			mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1073 	}
1074 
1075 	/* See if we can append the packet */
1076 	if (c->mfc_un.unres.unresolved.qlen > 3) {
1077 		kfree_skb(skb);
1078 		err = -ENOBUFS;
1079 	} else {
1080 		skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1081 		err = 0;
1082 	}
1083 
1084 	spin_unlock_bh(&mfc_unres_lock);
1085 	return err;
1086 }
1087 
1088 /* MFC cache manipulation by user space mroute daemon */
1089 
1090 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1091 {
1092 	int line;
1093 	struct mfc_cache *c, *next;
1094 
1095 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1096 
1097 	list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[line], list) {
1098 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1099 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr &&
1100 		    (parent == -1 || parent == c->mfc_parent)) {
1101 			list_del_rcu(&c->list);
1102 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1103 			ipmr_cache_free(c);
1104 			return 0;
1105 		}
1106 	}
1107 	return -ENOENT;
1108 }
1109 
1110 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1111 			struct mfcctl *mfc, int mrtsock, int parent)
1112 {
1113 	bool found = false;
1114 	int line;
1115 	struct mfc_cache *uc, *c;
1116 
1117 	if (mfc->mfcc_parent >= MAXVIFS)
1118 		return -ENFILE;
1119 
1120 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1121 
1122 	list_for_each_entry(c, &mrt->mfc_cache_array[line], list) {
1123 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1124 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr &&
1125 		    (parent == -1 || parent == c->mfc_parent)) {
1126 			found = true;
1127 			break;
1128 		}
1129 	}
1130 
1131 	if (found) {
1132 		write_lock_bh(&mrt_lock);
1133 		c->mfc_parent = mfc->mfcc_parent;
1134 		ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1135 		if (!mrtsock)
1136 			c->mfc_flags |= MFC_STATIC;
1137 		write_unlock_bh(&mrt_lock);
1138 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1139 		return 0;
1140 	}
1141 
1142 	if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1143 	    !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1144 		return -EINVAL;
1145 
1146 	c = ipmr_cache_alloc();
1147 	if (!c)
1148 		return -ENOMEM;
1149 
1150 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1151 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
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 
1157 	list_add_rcu(&c->list, &mrt->mfc_cache_array[line]);
1158 
1159 	/* Check to see if we resolved a queued list. If so we
1160 	 * need to send on the frames and tidy up.
1161 	 */
1162 	found = false;
1163 	spin_lock_bh(&mfc_unres_lock);
1164 	list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1165 		if (uc->mfc_origin == c->mfc_origin &&
1166 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1167 			list_del(&uc->list);
1168 			atomic_dec(&mrt->cache_resolve_queue_len);
1169 			found = true;
1170 			break;
1171 		}
1172 	}
1173 	if (list_empty(&mrt->mfc_unres_queue))
1174 		del_timer(&mrt->ipmr_expire_timer);
1175 	spin_unlock_bh(&mfc_unres_lock);
1176 
1177 	if (found) {
1178 		ipmr_cache_resolve(net, mrt, uc, c);
1179 		ipmr_cache_free(uc);
1180 	}
1181 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1182 	return 0;
1183 }
1184 
1185 /* Close the multicast socket, and clear the vif tables etc */
1186 static void mroute_clean_tables(struct mr_table *mrt, bool all)
1187 {
1188 	int i;
1189 	LIST_HEAD(list);
1190 	struct mfc_cache *c, *next;
1191 
1192 	/* Shut down all active vif entries */
1193 	for (i = 0; i < mrt->maxvif; i++) {
1194 		if (!all && (mrt->vif_table[i].flags & VIFF_STATIC))
1195 			continue;
1196 		vif_delete(mrt, i, 0, &list);
1197 	}
1198 	unregister_netdevice_many(&list);
1199 
1200 	/* Wipe the cache */
1201 	for (i = 0; i < MFC_LINES; i++) {
1202 		list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[i], list) {
1203 			if (!all && (c->mfc_flags & MFC_STATIC))
1204 				continue;
1205 			list_del_rcu(&c->list);
1206 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1207 			ipmr_cache_free(c);
1208 		}
1209 	}
1210 
1211 	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1212 		spin_lock_bh(&mfc_unres_lock);
1213 		list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
1214 			list_del(&c->list);
1215 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1216 			ipmr_destroy_unres(mrt, c);
1217 		}
1218 		spin_unlock_bh(&mfc_unres_lock);
1219 	}
1220 }
1221 
1222 /* called from ip_ra_control(), before an RCU grace period,
1223  * we dont need to call synchronize_rcu() here
1224  */
1225 static void mrtsock_destruct(struct sock *sk)
1226 {
1227 	struct net *net = sock_net(sk);
1228 	struct mr_table *mrt;
1229 
1230 	rtnl_lock();
1231 	ipmr_for_each_table(mrt, net) {
1232 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1233 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1234 			inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1235 						    NETCONFA_IFINDEX_ALL,
1236 						    net->ipv4.devconf_all);
1237 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1238 			mroute_clean_tables(mrt, false);
1239 		}
1240 	}
1241 	rtnl_unlock();
1242 }
1243 
1244 /* Socket options and virtual interface manipulation. The whole
1245  * virtual interface system is a complete heap, but unfortunately
1246  * that's how BSD mrouted happens to think. Maybe one day with a proper
1247  * MOSPF/PIM router set up we can clean this up.
1248  */
1249 
1250 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
1251 			 unsigned int optlen)
1252 {
1253 	struct net *net = sock_net(sk);
1254 	int val, ret = 0, parent = 0;
1255 	struct mr_table *mrt;
1256 	struct vifctl vif;
1257 	struct mfcctl mfc;
1258 	u32 uval;
1259 
1260 	/* There's one exception to the lock - MRT_DONE which needs to unlock */
1261 	rtnl_lock();
1262 	if (sk->sk_type != SOCK_RAW ||
1263 	    inet_sk(sk)->inet_num != IPPROTO_IGMP) {
1264 		ret = -EOPNOTSUPP;
1265 		goto out_unlock;
1266 	}
1267 
1268 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1269 	if (!mrt) {
1270 		ret = -ENOENT;
1271 		goto out_unlock;
1272 	}
1273 	if (optname != MRT_INIT) {
1274 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1275 		    !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
1276 			ret = -EACCES;
1277 			goto out_unlock;
1278 		}
1279 	}
1280 
1281 	switch (optname) {
1282 	case MRT_INIT:
1283 		if (optlen != sizeof(int)) {
1284 			ret = -EINVAL;
1285 			break;
1286 		}
1287 		if (rtnl_dereference(mrt->mroute_sk)) {
1288 			ret = -EADDRINUSE;
1289 			break;
1290 		}
1291 
1292 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1293 		if (ret == 0) {
1294 			rcu_assign_pointer(mrt->mroute_sk, sk);
1295 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1296 			inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1297 						    NETCONFA_IFINDEX_ALL,
1298 						    net->ipv4.devconf_all);
1299 		}
1300 		break;
1301 	case MRT_DONE:
1302 		if (sk != rcu_access_pointer(mrt->mroute_sk)) {
1303 			ret = -EACCES;
1304 		} else {
1305 			/* We need to unlock here because mrtsock_destruct takes
1306 			 * care of rtnl itself and we can't change that due to
1307 			 * the IP_ROUTER_ALERT setsockopt which runs without it.
1308 			 */
1309 			rtnl_unlock();
1310 			ret = ip_ra_control(sk, 0, NULL);
1311 			goto out;
1312 		}
1313 		break;
1314 	case MRT_ADD_VIF:
1315 	case MRT_DEL_VIF:
1316 		if (optlen != sizeof(vif)) {
1317 			ret = -EINVAL;
1318 			break;
1319 		}
1320 		if (copy_from_user(&vif, optval, sizeof(vif))) {
1321 			ret = -EFAULT;
1322 			break;
1323 		}
1324 		if (vif.vifc_vifi >= MAXVIFS) {
1325 			ret = -ENFILE;
1326 			break;
1327 		}
1328 		if (optname == MRT_ADD_VIF) {
1329 			ret = vif_add(net, mrt, &vif,
1330 				      sk == rtnl_dereference(mrt->mroute_sk));
1331 		} else {
1332 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1333 		}
1334 		break;
1335 	/* Manipulate the forwarding caches. These live
1336 	 * in a sort of kernel/user symbiosis.
1337 	 */
1338 	case MRT_ADD_MFC:
1339 	case MRT_DEL_MFC:
1340 		parent = -1;
1341 	case MRT_ADD_MFC_PROXY:
1342 	case MRT_DEL_MFC_PROXY:
1343 		if (optlen != sizeof(mfc)) {
1344 			ret = -EINVAL;
1345 			break;
1346 		}
1347 		if (copy_from_user(&mfc, optval, sizeof(mfc))) {
1348 			ret = -EFAULT;
1349 			break;
1350 		}
1351 		if (parent == 0)
1352 			parent = mfc.mfcc_parent;
1353 		if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1354 			ret = ipmr_mfc_delete(mrt, &mfc, parent);
1355 		else
1356 			ret = ipmr_mfc_add(net, mrt, &mfc,
1357 					   sk == rtnl_dereference(mrt->mroute_sk),
1358 					   parent);
1359 		break;
1360 	/* Control PIM assert. */
1361 	case MRT_ASSERT:
1362 		if (optlen != sizeof(val)) {
1363 			ret = -EINVAL;
1364 			break;
1365 		}
1366 		if (get_user(val, (int __user *)optval)) {
1367 			ret = -EFAULT;
1368 			break;
1369 		}
1370 		mrt->mroute_do_assert = val;
1371 		break;
1372 	case MRT_PIM:
1373 		if (!ipmr_pimsm_enabled()) {
1374 			ret = -ENOPROTOOPT;
1375 			break;
1376 		}
1377 		if (optlen != sizeof(val)) {
1378 			ret = -EINVAL;
1379 			break;
1380 		}
1381 		if (get_user(val, (int __user *)optval)) {
1382 			ret = -EFAULT;
1383 			break;
1384 		}
1385 
1386 		val = !!val;
1387 		if (val != mrt->mroute_do_pim) {
1388 			mrt->mroute_do_pim = val;
1389 			mrt->mroute_do_assert = val;
1390 		}
1391 		break;
1392 	case MRT_TABLE:
1393 		if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) {
1394 			ret = -ENOPROTOOPT;
1395 			break;
1396 		}
1397 		if (optlen != sizeof(uval)) {
1398 			ret = -EINVAL;
1399 			break;
1400 		}
1401 		if (get_user(uval, (u32 __user *)optval)) {
1402 			ret = -EFAULT;
1403 			break;
1404 		}
1405 
1406 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1407 			ret = -EBUSY;
1408 		} else {
1409 			mrt = ipmr_new_table(net, uval);
1410 			if (IS_ERR(mrt))
1411 				ret = PTR_ERR(mrt);
1412 			else
1413 				raw_sk(sk)->ipmr_table = uval;
1414 		}
1415 		break;
1416 	/* Spurious command, or MRT_VERSION which you cannot set. */
1417 	default:
1418 		ret = -ENOPROTOOPT;
1419 	}
1420 out_unlock:
1421 	rtnl_unlock();
1422 out:
1423 	return ret;
1424 }
1425 
1426 /* Getsock opt support for the multicast routing system. */
1427 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1428 {
1429 	int olr;
1430 	int val;
1431 	struct net *net = sock_net(sk);
1432 	struct mr_table *mrt;
1433 
1434 	if (sk->sk_type != SOCK_RAW ||
1435 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1436 		return -EOPNOTSUPP;
1437 
1438 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1439 	if (!mrt)
1440 		return -ENOENT;
1441 
1442 	switch (optname) {
1443 	case MRT_VERSION:
1444 		val = 0x0305;
1445 		break;
1446 	case MRT_PIM:
1447 		if (!ipmr_pimsm_enabled())
1448 			return -ENOPROTOOPT;
1449 		val = mrt->mroute_do_pim;
1450 		break;
1451 	case MRT_ASSERT:
1452 		val = mrt->mroute_do_assert;
1453 		break;
1454 	default:
1455 		return -ENOPROTOOPT;
1456 	}
1457 
1458 	if (get_user(olr, optlen))
1459 		return -EFAULT;
1460 	olr = min_t(unsigned int, olr, sizeof(int));
1461 	if (olr < 0)
1462 		return -EINVAL;
1463 	if (put_user(olr, optlen))
1464 		return -EFAULT;
1465 	if (copy_to_user(optval, &val, olr))
1466 		return -EFAULT;
1467 	return 0;
1468 }
1469 
1470 /* The IP multicast ioctl support routines. */
1471 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1472 {
1473 	struct sioc_sg_req sr;
1474 	struct sioc_vif_req vr;
1475 	struct vif_device *vif;
1476 	struct mfc_cache *c;
1477 	struct net *net = sock_net(sk);
1478 	struct mr_table *mrt;
1479 
1480 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1481 	if (!mrt)
1482 		return -ENOENT;
1483 
1484 	switch (cmd) {
1485 	case SIOCGETVIFCNT:
1486 		if (copy_from_user(&vr, arg, sizeof(vr)))
1487 			return -EFAULT;
1488 		if (vr.vifi >= mrt->maxvif)
1489 			return -EINVAL;
1490 		read_lock(&mrt_lock);
1491 		vif = &mrt->vif_table[vr.vifi];
1492 		if (VIF_EXISTS(mrt, vr.vifi)) {
1493 			vr.icount = vif->pkt_in;
1494 			vr.ocount = vif->pkt_out;
1495 			vr.ibytes = vif->bytes_in;
1496 			vr.obytes = vif->bytes_out;
1497 			read_unlock(&mrt_lock);
1498 
1499 			if (copy_to_user(arg, &vr, sizeof(vr)))
1500 				return -EFAULT;
1501 			return 0;
1502 		}
1503 		read_unlock(&mrt_lock);
1504 		return -EADDRNOTAVAIL;
1505 	case SIOCGETSGCNT:
1506 		if (copy_from_user(&sr, arg, sizeof(sr)))
1507 			return -EFAULT;
1508 
1509 		rcu_read_lock();
1510 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1511 		if (c) {
1512 			sr.pktcnt = c->mfc_un.res.pkt;
1513 			sr.bytecnt = c->mfc_un.res.bytes;
1514 			sr.wrong_if = c->mfc_un.res.wrong_if;
1515 			rcu_read_unlock();
1516 
1517 			if (copy_to_user(arg, &sr, sizeof(sr)))
1518 				return -EFAULT;
1519 			return 0;
1520 		}
1521 		rcu_read_unlock();
1522 		return -EADDRNOTAVAIL;
1523 	default:
1524 		return -ENOIOCTLCMD;
1525 	}
1526 }
1527 
1528 #ifdef CONFIG_COMPAT
1529 struct compat_sioc_sg_req {
1530 	struct in_addr src;
1531 	struct in_addr grp;
1532 	compat_ulong_t pktcnt;
1533 	compat_ulong_t bytecnt;
1534 	compat_ulong_t wrong_if;
1535 };
1536 
1537 struct compat_sioc_vif_req {
1538 	vifi_t	vifi;		/* Which iface */
1539 	compat_ulong_t icount;
1540 	compat_ulong_t ocount;
1541 	compat_ulong_t ibytes;
1542 	compat_ulong_t obytes;
1543 };
1544 
1545 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1546 {
1547 	struct compat_sioc_sg_req sr;
1548 	struct compat_sioc_vif_req vr;
1549 	struct vif_device *vif;
1550 	struct mfc_cache *c;
1551 	struct net *net = sock_net(sk);
1552 	struct mr_table *mrt;
1553 
1554 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1555 	if (!mrt)
1556 		return -ENOENT;
1557 
1558 	switch (cmd) {
1559 	case SIOCGETVIFCNT:
1560 		if (copy_from_user(&vr, arg, sizeof(vr)))
1561 			return -EFAULT;
1562 		if (vr.vifi >= mrt->maxvif)
1563 			return -EINVAL;
1564 		read_lock(&mrt_lock);
1565 		vif = &mrt->vif_table[vr.vifi];
1566 		if (VIF_EXISTS(mrt, vr.vifi)) {
1567 			vr.icount = vif->pkt_in;
1568 			vr.ocount = vif->pkt_out;
1569 			vr.ibytes = vif->bytes_in;
1570 			vr.obytes = vif->bytes_out;
1571 			read_unlock(&mrt_lock);
1572 
1573 			if (copy_to_user(arg, &vr, sizeof(vr)))
1574 				return -EFAULT;
1575 			return 0;
1576 		}
1577 		read_unlock(&mrt_lock);
1578 		return -EADDRNOTAVAIL;
1579 	case SIOCGETSGCNT:
1580 		if (copy_from_user(&sr, arg, sizeof(sr)))
1581 			return -EFAULT;
1582 
1583 		rcu_read_lock();
1584 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1585 		if (c) {
1586 			sr.pktcnt = c->mfc_un.res.pkt;
1587 			sr.bytecnt = c->mfc_un.res.bytes;
1588 			sr.wrong_if = c->mfc_un.res.wrong_if;
1589 			rcu_read_unlock();
1590 
1591 			if (copy_to_user(arg, &sr, sizeof(sr)))
1592 				return -EFAULT;
1593 			return 0;
1594 		}
1595 		rcu_read_unlock();
1596 		return -EADDRNOTAVAIL;
1597 	default:
1598 		return -ENOIOCTLCMD;
1599 	}
1600 }
1601 #endif
1602 
1603 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1604 {
1605 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1606 	struct net *net = dev_net(dev);
1607 	struct mr_table *mrt;
1608 	struct vif_device *v;
1609 	int ct;
1610 
1611 	if (event != NETDEV_UNREGISTER)
1612 		return NOTIFY_DONE;
1613 
1614 	ipmr_for_each_table(mrt, net) {
1615 		v = &mrt->vif_table[0];
1616 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1617 			if (v->dev == dev)
1618 				vif_delete(mrt, ct, 1, NULL);
1619 		}
1620 	}
1621 	return NOTIFY_DONE;
1622 }
1623 
1624 static struct notifier_block ip_mr_notifier = {
1625 	.notifier_call = ipmr_device_event,
1626 };
1627 
1628 /* Encapsulate a packet by attaching a valid IPIP header to it.
1629  * This avoids tunnel drivers and other mess and gives us the speed so
1630  * important for multicast video.
1631  */
1632 static void ip_encap(struct net *net, struct sk_buff *skb,
1633 		     __be32 saddr, __be32 daddr)
1634 {
1635 	struct iphdr *iph;
1636 	const struct iphdr *old_iph = ip_hdr(skb);
1637 
1638 	skb_push(skb, sizeof(struct iphdr));
1639 	skb->transport_header = skb->network_header;
1640 	skb_reset_network_header(skb);
1641 	iph = ip_hdr(skb);
1642 
1643 	iph->version	=	4;
1644 	iph->tos	=	old_iph->tos;
1645 	iph->ttl	=	old_iph->ttl;
1646 	iph->frag_off	=	0;
1647 	iph->daddr	=	daddr;
1648 	iph->saddr	=	saddr;
1649 	iph->protocol	=	IPPROTO_IPIP;
1650 	iph->ihl	=	5;
1651 	iph->tot_len	=	htons(skb->len);
1652 	ip_select_ident(net, skb, NULL);
1653 	ip_send_check(iph);
1654 
1655 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1656 	nf_reset(skb);
1657 }
1658 
1659 static inline int ipmr_forward_finish(struct net *net, struct sock *sk,
1660 				      struct sk_buff *skb)
1661 {
1662 	struct ip_options *opt = &(IPCB(skb)->opt);
1663 
1664 	IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
1665 	IP_ADD_STATS(net, IPSTATS_MIB_OUTOCTETS, skb->len);
1666 
1667 	if (unlikely(opt->optlen))
1668 		ip_forward_options(skb);
1669 
1670 	return dst_output(net, sk, skb);
1671 }
1672 
1673 /* Processing handlers for ipmr_forward */
1674 
1675 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1676 			    struct sk_buff *skb, struct mfc_cache *c, int vifi)
1677 {
1678 	const struct iphdr *iph = ip_hdr(skb);
1679 	struct vif_device *vif = &mrt->vif_table[vifi];
1680 	struct net_device *dev;
1681 	struct rtable *rt;
1682 	struct flowi4 fl4;
1683 	int    encap = 0;
1684 
1685 	if (!vif->dev)
1686 		goto out_free;
1687 
1688 	if (vif->flags & VIFF_REGISTER) {
1689 		vif->pkt_out++;
1690 		vif->bytes_out += skb->len;
1691 		vif->dev->stats.tx_bytes += skb->len;
1692 		vif->dev->stats.tx_packets++;
1693 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1694 		goto out_free;
1695 	}
1696 
1697 	if (vif->flags & VIFF_TUNNEL) {
1698 		rt = ip_route_output_ports(net, &fl4, NULL,
1699 					   vif->remote, vif->local,
1700 					   0, 0,
1701 					   IPPROTO_IPIP,
1702 					   RT_TOS(iph->tos), vif->link);
1703 		if (IS_ERR(rt))
1704 			goto out_free;
1705 		encap = sizeof(struct iphdr);
1706 	} else {
1707 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1708 					   0, 0,
1709 					   IPPROTO_IPIP,
1710 					   RT_TOS(iph->tos), vif->link);
1711 		if (IS_ERR(rt))
1712 			goto out_free;
1713 	}
1714 
1715 	dev = rt->dst.dev;
1716 
1717 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1718 		/* Do not fragment multicasts. Alas, IPv4 does not
1719 		 * allow to send ICMP, so that packets will disappear
1720 		 * to blackhole.
1721 		 */
1722 		IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
1723 		ip_rt_put(rt);
1724 		goto out_free;
1725 	}
1726 
1727 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1728 
1729 	if (skb_cow(skb, encap)) {
1730 		ip_rt_put(rt);
1731 		goto out_free;
1732 	}
1733 
1734 	vif->pkt_out++;
1735 	vif->bytes_out += skb->len;
1736 
1737 	skb_dst_drop(skb);
1738 	skb_dst_set(skb, &rt->dst);
1739 	ip_decrease_ttl(ip_hdr(skb));
1740 
1741 	/* FIXME: forward and output firewalls used to be called here.
1742 	 * What do we do with netfilter? -- RR
1743 	 */
1744 	if (vif->flags & VIFF_TUNNEL) {
1745 		ip_encap(net, skb, vif->local, vif->remote);
1746 		/* FIXME: extra output firewall step used to be here. --RR */
1747 		vif->dev->stats.tx_packets++;
1748 		vif->dev->stats.tx_bytes += skb->len;
1749 	}
1750 
1751 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1752 
1753 	/* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1754 	 * not only before forwarding, but after forwarding on all output
1755 	 * interfaces. It is clear, if mrouter runs a multicasting
1756 	 * program, it should receive packets not depending to what interface
1757 	 * program is joined.
1758 	 * If we will not make it, the program will have to join on all
1759 	 * interfaces. On the other hand, multihoming host (or router, but
1760 	 * not mrouter) cannot join to more than one interface - it will
1761 	 * result in receiving multiple packets.
1762 	 */
1763 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
1764 		net, NULL, skb, skb->dev, dev,
1765 		ipmr_forward_finish);
1766 	return;
1767 
1768 out_free:
1769 	kfree_skb(skb);
1770 }
1771 
1772 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1773 {
1774 	int ct;
1775 
1776 	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1777 		if (mrt->vif_table[ct].dev == dev)
1778 			break;
1779 	}
1780 	return ct;
1781 }
1782 
1783 /* "local" means that we should preserve one skb (for local delivery) */
1784 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
1785 			  struct sk_buff *skb, struct mfc_cache *cache,
1786 			  int local)
1787 {
1788 	int psend = -1;
1789 	int vif, ct;
1790 	int true_vifi = ipmr_find_vif(mrt, skb->dev);
1791 
1792 	vif = cache->mfc_parent;
1793 	cache->mfc_un.res.pkt++;
1794 	cache->mfc_un.res.bytes += skb->len;
1795 
1796 	if (cache->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
1797 		struct mfc_cache *cache_proxy;
1798 
1799 		/* For an (*,G) entry, we only check that the incomming
1800 		 * interface is part of the static tree.
1801 		 */
1802 		cache_proxy = ipmr_cache_find_any_parent(mrt, vif);
1803 		if (cache_proxy &&
1804 		    cache_proxy->mfc_un.res.ttls[true_vifi] < 255)
1805 			goto forward;
1806 	}
1807 
1808 	/* Wrong interface: drop packet and (maybe) send PIM assert. */
1809 	if (mrt->vif_table[vif].dev != skb->dev) {
1810 		if (rt_is_output_route(skb_rtable(skb))) {
1811 			/* It is our own packet, looped back.
1812 			 * Very complicated situation...
1813 			 *
1814 			 * The best workaround until routing daemons will be
1815 			 * fixed is not to redistribute packet, if it was
1816 			 * send through wrong interface. It means, that
1817 			 * multicast applications WILL NOT work for
1818 			 * (S,G), which have default multicast route pointing
1819 			 * to wrong oif. In any case, it is not a good
1820 			 * idea to use multicasting applications on router.
1821 			 */
1822 			goto dont_forward;
1823 		}
1824 
1825 		cache->mfc_un.res.wrong_if++;
1826 
1827 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
1828 		    /* pimsm uses asserts, when switching from RPT to SPT,
1829 		     * so that we cannot check that packet arrived on an oif.
1830 		     * It is bad, but otherwise we would need to move pretty
1831 		     * large chunk of pimd to kernel. Ough... --ANK
1832 		     */
1833 		    (mrt->mroute_do_pim ||
1834 		     cache->mfc_un.res.ttls[true_vifi] < 255) &&
1835 		    time_after(jiffies,
1836 			       cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1837 			cache->mfc_un.res.last_assert = jiffies;
1838 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1839 		}
1840 		goto dont_forward;
1841 	}
1842 
1843 forward:
1844 	mrt->vif_table[vif].pkt_in++;
1845 	mrt->vif_table[vif].bytes_in += skb->len;
1846 
1847 	/* Forward the frame */
1848 	if (cache->mfc_origin == htonl(INADDR_ANY) &&
1849 	    cache->mfc_mcastgrp == htonl(INADDR_ANY)) {
1850 		if (true_vifi >= 0 &&
1851 		    true_vifi != cache->mfc_parent &&
1852 		    ip_hdr(skb)->ttl >
1853 				cache->mfc_un.res.ttls[cache->mfc_parent]) {
1854 			/* It's an (*,*) entry and the packet is not coming from
1855 			 * the upstream: forward the packet to the upstream
1856 			 * only.
1857 			 */
1858 			psend = cache->mfc_parent;
1859 			goto last_forward;
1860 		}
1861 		goto dont_forward;
1862 	}
1863 	for (ct = cache->mfc_un.res.maxvif - 1;
1864 	     ct >= cache->mfc_un.res.minvif; ct--) {
1865 		/* For (*,G) entry, don't forward to the incoming interface */
1866 		if ((cache->mfc_origin != htonl(INADDR_ANY) ||
1867 		     ct != true_vifi) &&
1868 		    ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1869 			if (psend != -1) {
1870 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1871 
1872 				if (skb2)
1873 					ipmr_queue_xmit(net, mrt, skb2, cache,
1874 							psend);
1875 			}
1876 			psend = ct;
1877 		}
1878 	}
1879 last_forward:
1880 	if (psend != -1) {
1881 		if (local) {
1882 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1883 
1884 			if (skb2)
1885 				ipmr_queue_xmit(net, mrt, skb2, cache, psend);
1886 		} else {
1887 			ipmr_queue_xmit(net, mrt, skb, cache, psend);
1888 			return;
1889 		}
1890 	}
1891 
1892 dont_forward:
1893 	if (!local)
1894 		kfree_skb(skb);
1895 }
1896 
1897 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
1898 {
1899 	struct rtable *rt = skb_rtable(skb);
1900 	struct iphdr *iph = ip_hdr(skb);
1901 	struct flowi4 fl4 = {
1902 		.daddr = iph->daddr,
1903 		.saddr = iph->saddr,
1904 		.flowi4_tos = RT_TOS(iph->tos),
1905 		.flowi4_oif = (rt_is_output_route(rt) ?
1906 			       skb->dev->ifindex : 0),
1907 		.flowi4_iif = (rt_is_output_route(rt) ?
1908 			       LOOPBACK_IFINDEX :
1909 			       skb->dev->ifindex),
1910 		.flowi4_mark = skb->mark,
1911 	};
1912 	struct mr_table *mrt;
1913 	int err;
1914 
1915 	err = ipmr_fib_lookup(net, &fl4, &mrt);
1916 	if (err)
1917 		return ERR_PTR(err);
1918 	return mrt;
1919 }
1920 
1921 /* Multicast packets for forwarding arrive here
1922  * Called with rcu_read_lock();
1923  */
1924 int ip_mr_input(struct sk_buff *skb)
1925 {
1926 	struct mfc_cache *cache;
1927 	struct net *net = dev_net(skb->dev);
1928 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
1929 	struct mr_table *mrt;
1930 
1931 	/* Packet is looped back after forward, it should not be
1932 	 * forwarded second time, but still can be delivered locally.
1933 	 */
1934 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
1935 		goto dont_forward;
1936 
1937 	mrt = ipmr_rt_fib_lookup(net, skb);
1938 	if (IS_ERR(mrt)) {
1939 		kfree_skb(skb);
1940 		return PTR_ERR(mrt);
1941 	}
1942 	if (!local) {
1943 		if (IPCB(skb)->opt.router_alert) {
1944 			if (ip_call_ra_chain(skb))
1945 				return 0;
1946 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
1947 			/* IGMPv1 (and broken IGMPv2 implementations sort of
1948 			 * Cisco IOS <= 11.2(8)) do not put router alert
1949 			 * option to IGMP packets destined to routable
1950 			 * groups. It is very bad, because it means
1951 			 * that we can forward NO IGMP messages.
1952 			 */
1953 			struct sock *mroute_sk;
1954 
1955 			mroute_sk = rcu_dereference(mrt->mroute_sk);
1956 			if (mroute_sk) {
1957 				nf_reset(skb);
1958 				raw_rcv(mroute_sk, skb);
1959 				return 0;
1960 			}
1961 		    }
1962 	}
1963 
1964 	/* already under rcu_read_lock() */
1965 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
1966 	if (!cache) {
1967 		int vif = ipmr_find_vif(mrt, skb->dev);
1968 
1969 		if (vif >= 0)
1970 			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
1971 						    vif);
1972 	}
1973 
1974 	/* No usable cache entry */
1975 	if (!cache) {
1976 		int vif;
1977 
1978 		if (local) {
1979 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1980 			ip_local_deliver(skb);
1981 			if (!skb2)
1982 				return -ENOBUFS;
1983 			skb = skb2;
1984 		}
1985 
1986 		read_lock(&mrt_lock);
1987 		vif = ipmr_find_vif(mrt, skb->dev);
1988 		if (vif >= 0) {
1989 			int err2 = ipmr_cache_unresolved(mrt, vif, skb);
1990 			read_unlock(&mrt_lock);
1991 
1992 			return err2;
1993 		}
1994 		read_unlock(&mrt_lock);
1995 		kfree_skb(skb);
1996 		return -ENODEV;
1997 	}
1998 
1999 	read_lock(&mrt_lock);
2000 	ip_mr_forward(net, mrt, skb, cache, local);
2001 	read_unlock(&mrt_lock);
2002 
2003 	if (local)
2004 		return ip_local_deliver(skb);
2005 
2006 	return 0;
2007 
2008 dont_forward:
2009 	if (local)
2010 		return ip_local_deliver(skb);
2011 	kfree_skb(skb);
2012 	return 0;
2013 }
2014 
2015 #ifdef CONFIG_IP_PIMSM_V1
2016 /* Handle IGMP messages of PIMv1 */
2017 int pim_rcv_v1(struct sk_buff *skb)
2018 {
2019 	struct igmphdr *pim;
2020 	struct net *net = dev_net(skb->dev);
2021 	struct mr_table *mrt;
2022 
2023 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2024 		goto drop;
2025 
2026 	pim = igmp_hdr(skb);
2027 
2028 	mrt = ipmr_rt_fib_lookup(net, skb);
2029 	if (IS_ERR(mrt))
2030 		goto drop;
2031 	if (!mrt->mroute_do_pim ||
2032 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2033 		goto drop;
2034 
2035 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2036 drop:
2037 		kfree_skb(skb);
2038 	}
2039 	return 0;
2040 }
2041 #endif
2042 
2043 #ifdef CONFIG_IP_PIMSM_V2
2044 static int pim_rcv(struct sk_buff *skb)
2045 {
2046 	struct pimreghdr *pim;
2047 	struct net *net = dev_net(skb->dev);
2048 	struct mr_table *mrt;
2049 
2050 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2051 		goto drop;
2052 
2053 	pim = (struct pimreghdr *)skb_transport_header(skb);
2054 	if (pim->type != ((PIM_VERSION << 4) | (PIM_REGISTER)) ||
2055 	    (pim->flags & PIM_NULL_REGISTER) ||
2056 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2057 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2058 		goto drop;
2059 
2060 	mrt = ipmr_rt_fib_lookup(net, skb);
2061 	if (IS_ERR(mrt))
2062 		goto drop;
2063 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2064 drop:
2065 		kfree_skb(skb);
2066 	}
2067 	return 0;
2068 }
2069 #endif
2070 
2071 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2072 			      struct mfc_cache *c, struct rtmsg *rtm)
2073 {
2074 	int ct;
2075 	struct rtnexthop *nhp;
2076 	struct nlattr *mp_attr;
2077 	struct rta_mfc_stats mfcs;
2078 
2079 	/* If cache is unresolved, don't try to parse IIF and OIF */
2080 	if (c->mfc_parent >= MAXVIFS)
2081 		return -ENOENT;
2082 
2083 	if (VIF_EXISTS(mrt, c->mfc_parent) &&
2084 	    nla_put_u32(skb, RTA_IIF, mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
2085 		return -EMSGSIZE;
2086 
2087 	if (!(mp_attr = nla_nest_start(skb, RTA_MULTIPATH)))
2088 		return -EMSGSIZE;
2089 
2090 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
2091 		if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
2092 			if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp)))) {
2093 				nla_nest_cancel(skb, mp_attr);
2094 				return -EMSGSIZE;
2095 			}
2096 
2097 			nhp->rtnh_flags = 0;
2098 			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
2099 			nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
2100 			nhp->rtnh_len = sizeof(*nhp);
2101 		}
2102 	}
2103 
2104 	nla_nest_end(skb, mp_attr);
2105 
2106 	mfcs.mfcs_packets = c->mfc_un.res.pkt;
2107 	mfcs.mfcs_bytes = c->mfc_un.res.bytes;
2108 	mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
2109 	if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) < 0)
2110 		return -EMSGSIZE;
2111 
2112 	rtm->rtm_type = RTN_MULTICAST;
2113 	return 1;
2114 }
2115 
2116 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2117 		   __be32 saddr, __be32 daddr,
2118 		   struct rtmsg *rtm, int nowait)
2119 {
2120 	struct mfc_cache *cache;
2121 	struct mr_table *mrt;
2122 	int err;
2123 
2124 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2125 	if (!mrt)
2126 		return -ENOENT;
2127 
2128 	rcu_read_lock();
2129 	cache = ipmr_cache_find(mrt, saddr, daddr);
2130 	if (!cache && skb->dev) {
2131 		int vif = ipmr_find_vif(mrt, skb->dev);
2132 
2133 		if (vif >= 0)
2134 			cache = ipmr_cache_find_any(mrt, daddr, vif);
2135 	}
2136 	if (!cache) {
2137 		struct sk_buff *skb2;
2138 		struct iphdr *iph;
2139 		struct net_device *dev;
2140 		int vif = -1;
2141 
2142 		if (nowait) {
2143 			rcu_read_unlock();
2144 			return -EAGAIN;
2145 		}
2146 
2147 		dev = skb->dev;
2148 		read_lock(&mrt_lock);
2149 		if (dev)
2150 			vif = ipmr_find_vif(mrt, dev);
2151 		if (vif < 0) {
2152 			read_unlock(&mrt_lock);
2153 			rcu_read_unlock();
2154 			return -ENODEV;
2155 		}
2156 		skb2 = skb_clone(skb, GFP_ATOMIC);
2157 		if (!skb2) {
2158 			read_unlock(&mrt_lock);
2159 			rcu_read_unlock();
2160 			return -ENOMEM;
2161 		}
2162 
2163 		skb_push(skb2, sizeof(struct iphdr));
2164 		skb_reset_network_header(skb2);
2165 		iph = ip_hdr(skb2);
2166 		iph->ihl = sizeof(struct iphdr) >> 2;
2167 		iph->saddr = saddr;
2168 		iph->daddr = daddr;
2169 		iph->version = 0;
2170 		err = ipmr_cache_unresolved(mrt, vif, skb2);
2171 		read_unlock(&mrt_lock);
2172 		rcu_read_unlock();
2173 		return err;
2174 	}
2175 
2176 	read_lock(&mrt_lock);
2177 	err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2178 	read_unlock(&mrt_lock);
2179 	rcu_read_unlock();
2180 	return err;
2181 }
2182 
2183 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2184 			    u32 portid, u32 seq, struct mfc_cache *c, int cmd,
2185 			    int flags)
2186 {
2187 	struct nlmsghdr *nlh;
2188 	struct rtmsg *rtm;
2189 	int err;
2190 
2191 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2192 	if (!nlh)
2193 		return -EMSGSIZE;
2194 
2195 	rtm = nlmsg_data(nlh);
2196 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2197 	rtm->rtm_dst_len  = 32;
2198 	rtm->rtm_src_len  = 32;
2199 	rtm->rtm_tos      = 0;
2200 	rtm->rtm_table    = mrt->id;
2201 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2202 		goto nla_put_failure;
2203 	rtm->rtm_type     = RTN_MULTICAST;
2204 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2205 	if (c->mfc_flags & MFC_STATIC)
2206 		rtm->rtm_protocol = RTPROT_STATIC;
2207 	else
2208 		rtm->rtm_protocol = RTPROT_MROUTED;
2209 	rtm->rtm_flags    = 0;
2210 
2211 	if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
2212 	    nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
2213 		goto nla_put_failure;
2214 	err = __ipmr_fill_mroute(mrt, skb, c, rtm);
2215 	/* do not break the dump if cache is unresolved */
2216 	if (err < 0 && err != -ENOENT)
2217 		goto nla_put_failure;
2218 
2219 	nlmsg_end(skb, nlh);
2220 	return 0;
2221 
2222 nla_put_failure:
2223 	nlmsg_cancel(skb, nlh);
2224 	return -EMSGSIZE;
2225 }
2226 
2227 static size_t mroute_msgsize(bool unresolved, int maxvif)
2228 {
2229 	size_t len =
2230 		NLMSG_ALIGN(sizeof(struct rtmsg))
2231 		+ nla_total_size(4)	/* RTA_TABLE */
2232 		+ nla_total_size(4)	/* RTA_SRC */
2233 		+ nla_total_size(4)	/* RTA_DST */
2234 		;
2235 
2236 	if (!unresolved)
2237 		len = len
2238 		      + nla_total_size(4)	/* RTA_IIF */
2239 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2240 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2241 						/* RTA_MFC_STATS */
2242 		      + nla_total_size_64bit(sizeof(struct rta_mfc_stats))
2243 		;
2244 
2245 	return len;
2246 }
2247 
2248 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2249 				 int cmd)
2250 {
2251 	struct net *net = read_pnet(&mrt->net);
2252 	struct sk_buff *skb;
2253 	int err = -ENOBUFS;
2254 
2255 	skb = nlmsg_new(mroute_msgsize(mfc->mfc_parent >= MAXVIFS, mrt->maxvif),
2256 			GFP_ATOMIC);
2257 	if (!skb)
2258 		goto errout;
2259 
2260 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2261 	if (err < 0)
2262 		goto errout;
2263 
2264 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2265 	return;
2266 
2267 errout:
2268 	kfree_skb(skb);
2269 	if (err < 0)
2270 		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2271 }
2272 
2273 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2274 {
2275 	struct net *net = sock_net(skb->sk);
2276 	struct mr_table *mrt;
2277 	struct mfc_cache *mfc;
2278 	unsigned int t = 0, s_t;
2279 	unsigned int h = 0, s_h;
2280 	unsigned int e = 0, s_e;
2281 
2282 	s_t = cb->args[0];
2283 	s_h = cb->args[1];
2284 	s_e = cb->args[2];
2285 
2286 	rcu_read_lock();
2287 	ipmr_for_each_table(mrt, net) {
2288 		if (t < s_t)
2289 			goto next_table;
2290 		if (t > s_t)
2291 			s_h = 0;
2292 		for (h = s_h; h < MFC_LINES; h++) {
2293 			list_for_each_entry_rcu(mfc, &mrt->mfc_cache_array[h], list) {
2294 				if (e < s_e)
2295 					goto next_entry;
2296 				if (ipmr_fill_mroute(mrt, skb,
2297 						     NETLINK_CB(cb->skb).portid,
2298 						     cb->nlh->nlmsg_seq,
2299 						     mfc, RTM_NEWROUTE,
2300 						     NLM_F_MULTI) < 0)
2301 					goto done;
2302 next_entry:
2303 				e++;
2304 			}
2305 			e = s_e = 0;
2306 		}
2307 		spin_lock_bh(&mfc_unres_lock);
2308 		list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
2309 			if (e < s_e)
2310 				goto next_entry2;
2311 			if (ipmr_fill_mroute(mrt, skb,
2312 					     NETLINK_CB(cb->skb).portid,
2313 					     cb->nlh->nlmsg_seq,
2314 					     mfc, RTM_NEWROUTE,
2315 					     NLM_F_MULTI) < 0) {
2316 				spin_unlock_bh(&mfc_unres_lock);
2317 				goto done;
2318 			}
2319 next_entry2:
2320 			e++;
2321 		}
2322 		spin_unlock_bh(&mfc_unres_lock);
2323 		e = s_e = 0;
2324 		s_h = 0;
2325 next_table:
2326 		t++;
2327 	}
2328 done:
2329 	rcu_read_unlock();
2330 
2331 	cb->args[2] = e;
2332 	cb->args[1] = h;
2333 	cb->args[0] = t;
2334 
2335 	return skb->len;
2336 }
2337 
2338 static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {
2339 	[RTA_SRC]	= { .type = NLA_U32 },
2340 	[RTA_DST]	= { .type = NLA_U32 },
2341 	[RTA_IIF]	= { .type = NLA_U32 },
2342 	[RTA_TABLE]	= { .type = NLA_U32 },
2343 	[RTA_MULTIPATH]	= { .len = sizeof(struct rtnexthop) },
2344 };
2345 
2346 static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol)
2347 {
2348 	switch (rtm_protocol) {
2349 	case RTPROT_STATIC:
2350 	case RTPROT_MROUTED:
2351 		return true;
2352 	}
2353 	return false;
2354 }
2355 
2356 static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc)
2357 {
2358 	struct rtnexthop *rtnh = nla_data(nla);
2359 	int remaining = nla_len(nla), vifi = 0;
2360 
2361 	while (rtnh_ok(rtnh, remaining)) {
2362 		mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops;
2363 		if (++vifi == MAXVIFS)
2364 			break;
2365 		rtnh = rtnh_next(rtnh, &remaining);
2366 	}
2367 
2368 	return remaining > 0 ? -EINVAL : vifi;
2369 }
2370 
2371 /* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */
2372 static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
2373 			    struct mfcctl *mfcc, int *mrtsock,
2374 			    struct mr_table **mrtret)
2375 {
2376 	struct net_device *dev = NULL;
2377 	u32 tblid = RT_TABLE_DEFAULT;
2378 	struct mr_table *mrt;
2379 	struct nlattr *attr;
2380 	struct rtmsg *rtm;
2381 	int ret, rem;
2382 
2383 	ret = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipmr_policy);
2384 	if (ret < 0)
2385 		goto out;
2386 	rtm = nlmsg_data(nlh);
2387 
2388 	ret = -EINVAL;
2389 	if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 ||
2390 	    rtm->rtm_type != RTN_MULTICAST ||
2391 	    rtm->rtm_scope != RT_SCOPE_UNIVERSE ||
2392 	    !ipmr_rtm_validate_proto(rtm->rtm_protocol))
2393 		goto out;
2394 
2395 	memset(mfcc, 0, sizeof(*mfcc));
2396 	mfcc->mfcc_parent = -1;
2397 	ret = 0;
2398 	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) {
2399 		switch (nla_type(attr)) {
2400 		case RTA_SRC:
2401 			mfcc->mfcc_origin.s_addr = nla_get_be32(attr);
2402 			break;
2403 		case RTA_DST:
2404 			mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr);
2405 			break;
2406 		case RTA_IIF:
2407 			dev = __dev_get_by_index(net, nla_get_u32(attr));
2408 			if (!dev) {
2409 				ret = -ENODEV;
2410 				goto out;
2411 			}
2412 			break;
2413 		case RTA_MULTIPATH:
2414 			if (ipmr_nla_get_ttls(attr, mfcc) < 0) {
2415 				ret = -EINVAL;
2416 				goto out;
2417 			}
2418 			break;
2419 		case RTA_PREFSRC:
2420 			ret = 1;
2421 			break;
2422 		case RTA_TABLE:
2423 			tblid = nla_get_u32(attr);
2424 			break;
2425 		}
2426 	}
2427 	mrt = ipmr_get_table(net, tblid);
2428 	if (!mrt) {
2429 		ret = -ENOENT;
2430 		goto out;
2431 	}
2432 	*mrtret = mrt;
2433 	*mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0;
2434 	if (dev)
2435 		mfcc->mfcc_parent = ipmr_find_vif(mrt, dev);
2436 
2437 out:
2438 	return ret;
2439 }
2440 
2441 /* takes care of both newroute and delroute */
2442 static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh)
2443 {
2444 	struct net *net = sock_net(skb->sk);
2445 	int ret, mrtsock, parent;
2446 	struct mr_table *tbl;
2447 	struct mfcctl mfcc;
2448 
2449 	mrtsock = 0;
2450 	tbl = NULL;
2451 	ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl);
2452 	if (ret < 0)
2453 		return ret;
2454 
2455 	parent = ret ? mfcc.mfcc_parent : -1;
2456 	if (nlh->nlmsg_type == RTM_NEWROUTE)
2457 		return ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent);
2458 	else
2459 		return ipmr_mfc_delete(tbl, &mfcc, parent);
2460 }
2461 
2462 #ifdef CONFIG_PROC_FS
2463 /* The /proc interfaces to multicast routing :
2464  * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2465  */
2466 struct ipmr_vif_iter {
2467 	struct seq_net_private p;
2468 	struct mr_table *mrt;
2469 	int ct;
2470 };
2471 
2472 static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2473 					   struct ipmr_vif_iter *iter,
2474 					   loff_t pos)
2475 {
2476 	struct mr_table *mrt = iter->mrt;
2477 
2478 	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2479 		if (!VIF_EXISTS(mrt, iter->ct))
2480 			continue;
2481 		if (pos-- == 0)
2482 			return &mrt->vif_table[iter->ct];
2483 	}
2484 	return NULL;
2485 }
2486 
2487 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2488 	__acquires(mrt_lock)
2489 {
2490 	struct ipmr_vif_iter *iter = seq->private;
2491 	struct net *net = seq_file_net(seq);
2492 	struct mr_table *mrt;
2493 
2494 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2495 	if (!mrt)
2496 		return ERR_PTR(-ENOENT);
2497 
2498 	iter->mrt = mrt;
2499 
2500 	read_lock(&mrt_lock);
2501 	return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2502 		: SEQ_START_TOKEN;
2503 }
2504 
2505 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2506 {
2507 	struct ipmr_vif_iter *iter = seq->private;
2508 	struct net *net = seq_file_net(seq);
2509 	struct mr_table *mrt = iter->mrt;
2510 
2511 	++*pos;
2512 	if (v == SEQ_START_TOKEN)
2513 		return ipmr_vif_seq_idx(net, iter, 0);
2514 
2515 	while (++iter->ct < mrt->maxvif) {
2516 		if (!VIF_EXISTS(mrt, iter->ct))
2517 			continue;
2518 		return &mrt->vif_table[iter->ct];
2519 	}
2520 	return NULL;
2521 }
2522 
2523 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2524 	__releases(mrt_lock)
2525 {
2526 	read_unlock(&mrt_lock);
2527 }
2528 
2529 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2530 {
2531 	struct ipmr_vif_iter *iter = seq->private;
2532 	struct mr_table *mrt = iter->mrt;
2533 
2534 	if (v == SEQ_START_TOKEN) {
2535 		seq_puts(seq,
2536 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2537 	} else {
2538 		const struct vif_device *vif = v;
2539 		const char *name =  vif->dev ? vif->dev->name : "none";
2540 
2541 		seq_printf(seq,
2542 			   "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2543 			   vif - mrt->vif_table,
2544 			   name, vif->bytes_in, vif->pkt_in,
2545 			   vif->bytes_out, vif->pkt_out,
2546 			   vif->flags, vif->local, vif->remote);
2547 	}
2548 	return 0;
2549 }
2550 
2551 static const struct seq_operations ipmr_vif_seq_ops = {
2552 	.start = ipmr_vif_seq_start,
2553 	.next  = ipmr_vif_seq_next,
2554 	.stop  = ipmr_vif_seq_stop,
2555 	.show  = ipmr_vif_seq_show,
2556 };
2557 
2558 static int ipmr_vif_open(struct inode *inode, struct file *file)
2559 {
2560 	return seq_open_net(inode, file, &ipmr_vif_seq_ops,
2561 			    sizeof(struct ipmr_vif_iter));
2562 }
2563 
2564 static const struct file_operations ipmr_vif_fops = {
2565 	.owner	 = THIS_MODULE,
2566 	.open    = ipmr_vif_open,
2567 	.read    = seq_read,
2568 	.llseek  = seq_lseek,
2569 	.release = seq_release_net,
2570 };
2571 
2572 struct ipmr_mfc_iter {
2573 	struct seq_net_private p;
2574 	struct mr_table *mrt;
2575 	struct list_head *cache;
2576 	int ct;
2577 };
2578 
2579 
2580 static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
2581 					  struct ipmr_mfc_iter *it, loff_t pos)
2582 {
2583 	struct mr_table *mrt = it->mrt;
2584 	struct mfc_cache *mfc;
2585 
2586 	rcu_read_lock();
2587 	for (it->ct = 0; it->ct < MFC_LINES; it->ct++) {
2588 		it->cache = &mrt->mfc_cache_array[it->ct];
2589 		list_for_each_entry_rcu(mfc, it->cache, list)
2590 			if (pos-- == 0)
2591 				return mfc;
2592 	}
2593 	rcu_read_unlock();
2594 
2595 	spin_lock_bh(&mfc_unres_lock);
2596 	it->cache = &mrt->mfc_unres_queue;
2597 	list_for_each_entry(mfc, it->cache, list)
2598 		if (pos-- == 0)
2599 			return mfc;
2600 	spin_unlock_bh(&mfc_unres_lock);
2601 
2602 	it->cache = NULL;
2603 	return NULL;
2604 }
2605 
2606 
2607 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2608 {
2609 	struct ipmr_mfc_iter *it = seq->private;
2610 	struct net *net = seq_file_net(seq);
2611 	struct mr_table *mrt;
2612 
2613 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2614 	if (!mrt)
2615 		return ERR_PTR(-ENOENT);
2616 
2617 	it->mrt = mrt;
2618 	it->cache = NULL;
2619 	it->ct = 0;
2620 	return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
2621 		: SEQ_START_TOKEN;
2622 }
2623 
2624 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2625 {
2626 	struct mfc_cache *mfc = v;
2627 	struct ipmr_mfc_iter *it = seq->private;
2628 	struct net *net = seq_file_net(seq);
2629 	struct mr_table *mrt = it->mrt;
2630 
2631 	++*pos;
2632 
2633 	if (v == SEQ_START_TOKEN)
2634 		return ipmr_mfc_seq_idx(net, seq->private, 0);
2635 
2636 	if (mfc->list.next != it->cache)
2637 		return list_entry(mfc->list.next, struct mfc_cache, list);
2638 
2639 	if (it->cache == &mrt->mfc_unres_queue)
2640 		goto end_of_list;
2641 
2642 	BUG_ON(it->cache != &mrt->mfc_cache_array[it->ct]);
2643 
2644 	while (++it->ct < MFC_LINES) {
2645 		it->cache = &mrt->mfc_cache_array[it->ct];
2646 		if (list_empty(it->cache))
2647 			continue;
2648 		return list_first_entry(it->cache, struct mfc_cache, list);
2649 	}
2650 
2651 	/* exhausted cache_array, show unresolved */
2652 	rcu_read_unlock();
2653 	it->cache = &mrt->mfc_unres_queue;
2654 	it->ct = 0;
2655 
2656 	spin_lock_bh(&mfc_unres_lock);
2657 	if (!list_empty(it->cache))
2658 		return list_first_entry(it->cache, struct mfc_cache, list);
2659 
2660 end_of_list:
2661 	spin_unlock_bh(&mfc_unres_lock);
2662 	it->cache = NULL;
2663 
2664 	return NULL;
2665 }
2666 
2667 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
2668 {
2669 	struct ipmr_mfc_iter *it = seq->private;
2670 	struct mr_table *mrt = it->mrt;
2671 
2672 	if (it->cache == &mrt->mfc_unres_queue)
2673 		spin_unlock_bh(&mfc_unres_lock);
2674 	else if (it->cache == &mrt->mfc_cache_array[it->ct])
2675 		rcu_read_unlock();
2676 }
2677 
2678 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2679 {
2680 	int n;
2681 
2682 	if (v == SEQ_START_TOKEN) {
2683 		seq_puts(seq,
2684 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2685 	} else {
2686 		const struct mfc_cache *mfc = v;
2687 		const struct ipmr_mfc_iter *it = seq->private;
2688 		const struct mr_table *mrt = it->mrt;
2689 
2690 		seq_printf(seq, "%08X %08X %-3hd",
2691 			   (__force u32) mfc->mfc_mcastgrp,
2692 			   (__force u32) mfc->mfc_origin,
2693 			   mfc->mfc_parent);
2694 
2695 		if (it->cache != &mrt->mfc_unres_queue) {
2696 			seq_printf(seq, " %8lu %8lu %8lu",
2697 				   mfc->mfc_un.res.pkt,
2698 				   mfc->mfc_un.res.bytes,
2699 				   mfc->mfc_un.res.wrong_if);
2700 			for (n = mfc->mfc_un.res.minvif;
2701 			     n < mfc->mfc_un.res.maxvif; n++) {
2702 				if (VIF_EXISTS(mrt, n) &&
2703 				    mfc->mfc_un.res.ttls[n] < 255)
2704 					seq_printf(seq,
2705 					   " %2d:%-3d",
2706 					   n, mfc->mfc_un.res.ttls[n]);
2707 			}
2708 		} else {
2709 			/* unresolved mfc_caches don't contain
2710 			 * pkt, bytes and wrong_if values
2711 			 */
2712 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
2713 		}
2714 		seq_putc(seq, '\n');
2715 	}
2716 	return 0;
2717 }
2718 
2719 static const struct seq_operations ipmr_mfc_seq_ops = {
2720 	.start = ipmr_mfc_seq_start,
2721 	.next  = ipmr_mfc_seq_next,
2722 	.stop  = ipmr_mfc_seq_stop,
2723 	.show  = ipmr_mfc_seq_show,
2724 };
2725 
2726 static int ipmr_mfc_open(struct inode *inode, struct file *file)
2727 {
2728 	return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
2729 			    sizeof(struct ipmr_mfc_iter));
2730 }
2731 
2732 static const struct file_operations ipmr_mfc_fops = {
2733 	.owner	 = THIS_MODULE,
2734 	.open    = ipmr_mfc_open,
2735 	.read    = seq_read,
2736 	.llseek  = seq_lseek,
2737 	.release = seq_release_net,
2738 };
2739 #endif
2740 
2741 #ifdef CONFIG_IP_PIMSM_V2
2742 static const struct net_protocol pim_protocol = {
2743 	.handler	=	pim_rcv,
2744 	.netns_ok	=	1,
2745 };
2746 #endif
2747 
2748 /* Setup for IP multicast routing */
2749 static int __net_init ipmr_net_init(struct net *net)
2750 {
2751 	int err;
2752 
2753 	err = ipmr_rules_init(net);
2754 	if (err < 0)
2755 		goto fail;
2756 
2757 #ifdef CONFIG_PROC_FS
2758 	err = -ENOMEM;
2759 	if (!proc_create("ip_mr_vif", 0, net->proc_net, &ipmr_vif_fops))
2760 		goto proc_vif_fail;
2761 	if (!proc_create("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_fops))
2762 		goto proc_cache_fail;
2763 #endif
2764 	return 0;
2765 
2766 #ifdef CONFIG_PROC_FS
2767 proc_cache_fail:
2768 	remove_proc_entry("ip_mr_vif", net->proc_net);
2769 proc_vif_fail:
2770 	ipmr_rules_exit(net);
2771 #endif
2772 fail:
2773 	return err;
2774 }
2775 
2776 static void __net_exit ipmr_net_exit(struct net *net)
2777 {
2778 #ifdef CONFIG_PROC_FS
2779 	remove_proc_entry("ip_mr_cache", net->proc_net);
2780 	remove_proc_entry("ip_mr_vif", net->proc_net);
2781 #endif
2782 	ipmr_rules_exit(net);
2783 }
2784 
2785 static struct pernet_operations ipmr_net_ops = {
2786 	.init = ipmr_net_init,
2787 	.exit = ipmr_net_exit,
2788 };
2789 
2790 int __init ip_mr_init(void)
2791 {
2792 	int err;
2793 
2794 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
2795 				       sizeof(struct mfc_cache),
2796 				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
2797 				       NULL);
2798 
2799 	err = register_pernet_subsys(&ipmr_net_ops);
2800 	if (err)
2801 		goto reg_pernet_fail;
2802 
2803 	err = register_netdevice_notifier(&ip_mr_notifier);
2804 	if (err)
2805 		goto reg_notif_fail;
2806 #ifdef CONFIG_IP_PIMSM_V2
2807 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
2808 		pr_err("%s: can't add PIM protocol\n", __func__);
2809 		err = -EAGAIN;
2810 		goto add_proto_fail;
2811 	}
2812 #endif
2813 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
2814 		      NULL, ipmr_rtm_dumproute, NULL);
2815 	rtnl_register(RTNL_FAMILY_IPMR, RTM_NEWROUTE,
2816 		      ipmr_rtm_route, NULL, NULL);
2817 	rtnl_register(RTNL_FAMILY_IPMR, RTM_DELROUTE,
2818 		      ipmr_rtm_route, NULL, NULL);
2819 	return 0;
2820 
2821 #ifdef CONFIG_IP_PIMSM_V2
2822 add_proto_fail:
2823 	unregister_netdevice_notifier(&ip_mr_notifier);
2824 #endif
2825 reg_notif_fail:
2826 	unregister_pernet_subsys(&ipmr_net_ops);
2827 reg_pernet_fail:
2828 	kmem_cache_destroy(mrt_cachep);
2829 	return err;
2830 }
2831