xref: /linux/net/ipv4/ipmr.c (revision 8c749ce93ee69e789e46b3be98de9e0cbfcf8ed8)
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.minvif = MAXVIFS;
896 	return c;
897 }
898 
899 static struct mfc_cache *ipmr_cache_alloc_unres(void)
900 {
901 	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
902 
903 	if (c) {
904 		skb_queue_head_init(&c->mfc_un.unres.unresolved);
905 		c->mfc_un.unres.expires = jiffies + 10*HZ;
906 	}
907 	return c;
908 }
909 
910 /* A cache entry has gone into a resolved state from queued */
911 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
912 			       struct mfc_cache *uc, struct mfc_cache *c)
913 {
914 	struct sk_buff *skb;
915 	struct nlmsgerr *e;
916 
917 	/* Play the pending entries through our router */
918 	while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
919 		if (ip_hdr(skb)->version == 0) {
920 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
921 
922 			if (__ipmr_fill_mroute(mrt, skb, c, nlmsg_data(nlh)) > 0) {
923 				nlh->nlmsg_len = skb_tail_pointer(skb) -
924 						 (u8 *)nlh;
925 			} else {
926 				nlh->nlmsg_type = NLMSG_ERROR;
927 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
928 				skb_trim(skb, nlh->nlmsg_len);
929 				e = nlmsg_data(nlh);
930 				e->error = -EMSGSIZE;
931 				memset(&e->msg, 0, sizeof(e->msg));
932 			}
933 
934 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
935 		} else {
936 			ip_mr_forward(net, mrt, skb, c, 0);
937 		}
938 	}
939 }
940 
941 /* Bounce a cache query up to mrouted. We could use netlink for this but mrouted
942  * expects the following bizarre scheme.
943  *
944  * Called under mrt_lock.
945  */
946 static int ipmr_cache_report(struct mr_table *mrt,
947 			     struct sk_buff *pkt, vifi_t vifi, int assert)
948 {
949 	const int ihl = ip_hdrlen(pkt);
950 	struct sock *mroute_sk;
951 	struct igmphdr *igmp;
952 	struct igmpmsg *msg;
953 	struct sk_buff *skb;
954 	int ret;
955 
956 	if (assert == IGMPMSG_WHOLEPKT)
957 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
958 	else
959 		skb = alloc_skb(128, GFP_ATOMIC);
960 
961 	if (!skb)
962 		return -ENOBUFS;
963 
964 	if (assert == IGMPMSG_WHOLEPKT) {
965 		/* Ugly, but we have no choice with this interface.
966 		 * Duplicate old header, fix ihl, length etc.
967 		 * And all this only to mangle msg->im_msgtype and
968 		 * to set msg->im_mbz to "mbz" :-)
969 		 */
970 		skb_push(skb, sizeof(struct iphdr));
971 		skb_reset_network_header(skb);
972 		skb_reset_transport_header(skb);
973 		msg = (struct igmpmsg *)skb_network_header(skb);
974 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
975 		msg->im_msgtype = IGMPMSG_WHOLEPKT;
976 		msg->im_mbz = 0;
977 		msg->im_vif = mrt->mroute_reg_vif_num;
978 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
979 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
980 					     sizeof(struct iphdr));
981 	} else {
982 		/* Copy the IP header */
983 		skb_set_network_header(skb, skb->len);
984 		skb_put(skb, ihl);
985 		skb_copy_to_linear_data(skb, pkt->data, ihl);
986 		/* Flag to the kernel this is a route add */
987 		ip_hdr(skb)->protocol = 0;
988 		msg = (struct igmpmsg *)skb_network_header(skb);
989 		msg->im_vif = vifi;
990 		skb_dst_set(skb, dst_clone(skb_dst(pkt)));
991 		/* Add our header */
992 		igmp = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
993 		igmp->type = assert;
994 		msg->im_msgtype = assert;
995 		igmp->code = 0;
996 		ip_hdr(skb)->tot_len = htons(skb->len);	/* Fix the length */
997 		skb->transport_header = skb->network_header;
998 	}
999 
1000 	rcu_read_lock();
1001 	mroute_sk = rcu_dereference(mrt->mroute_sk);
1002 	if (!mroute_sk) {
1003 		rcu_read_unlock();
1004 		kfree_skb(skb);
1005 		return -EINVAL;
1006 	}
1007 
1008 	/* Deliver to mrouted */
1009 	ret = sock_queue_rcv_skb(mroute_sk, skb);
1010 	rcu_read_unlock();
1011 	if (ret < 0) {
1012 		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1013 		kfree_skb(skb);
1014 	}
1015 
1016 	return ret;
1017 }
1018 
1019 /* Queue a packet for resolution. It gets locked cache entry! */
1020 static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
1021 				 struct sk_buff *skb)
1022 {
1023 	bool found = false;
1024 	int err;
1025 	struct mfc_cache *c;
1026 	const struct iphdr *iph = ip_hdr(skb);
1027 
1028 	spin_lock_bh(&mfc_unres_lock);
1029 	list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
1030 		if (c->mfc_mcastgrp == iph->daddr &&
1031 		    c->mfc_origin == iph->saddr) {
1032 			found = true;
1033 			break;
1034 		}
1035 	}
1036 
1037 	if (!found) {
1038 		/* Create a new entry if allowable */
1039 		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
1040 		    (c = ipmr_cache_alloc_unres()) == NULL) {
1041 			spin_unlock_bh(&mfc_unres_lock);
1042 
1043 			kfree_skb(skb);
1044 			return -ENOBUFS;
1045 		}
1046 
1047 		/* Fill in the new cache entry */
1048 		c->mfc_parent	= -1;
1049 		c->mfc_origin	= iph->saddr;
1050 		c->mfc_mcastgrp	= iph->daddr;
1051 
1052 		/* Reflect first query at mrouted. */
1053 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1054 		if (err < 0) {
1055 			/* If the report failed throw the cache entry
1056 			   out - Brad Parker
1057 			 */
1058 			spin_unlock_bh(&mfc_unres_lock);
1059 
1060 			ipmr_cache_free(c);
1061 			kfree_skb(skb);
1062 			return err;
1063 		}
1064 
1065 		atomic_inc(&mrt->cache_resolve_queue_len);
1066 		list_add(&c->list, &mrt->mfc_unres_queue);
1067 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1068 
1069 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1070 			mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1071 	}
1072 
1073 	/* See if we can append the packet */
1074 	if (c->mfc_un.unres.unresolved.qlen > 3) {
1075 		kfree_skb(skb);
1076 		err = -ENOBUFS;
1077 	} else {
1078 		skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1079 		err = 0;
1080 	}
1081 
1082 	spin_unlock_bh(&mfc_unres_lock);
1083 	return err;
1084 }
1085 
1086 /* MFC cache manipulation by user space mroute daemon */
1087 
1088 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1089 {
1090 	int line;
1091 	struct mfc_cache *c, *next;
1092 
1093 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1094 
1095 	list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[line], list) {
1096 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1097 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr &&
1098 		    (parent == -1 || parent == c->mfc_parent)) {
1099 			list_del_rcu(&c->list);
1100 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1101 			ipmr_cache_free(c);
1102 			return 0;
1103 		}
1104 	}
1105 	return -ENOENT;
1106 }
1107 
1108 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1109 			struct mfcctl *mfc, int mrtsock, int parent)
1110 {
1111 	bool found = false;
1112 	int line;
1113 	struct mfc_cache *uc, *c;
1114 
1115 	if (mfc->mfcc_parent >= MAXVIFS)
1116 		return -ENFILE;
1117 
1118 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1119 
1120 	list_for_each_entry(c, &mrt->mfc_cache_array[line], list) {
1121 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1122 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr &&
1123 		    (parent == -1 || parent == c->mfc_parent)) {
1124 			found = true;
1125 			break;
1126 		}
1127 	}
1128 
1129 	if (found) {
1130 		write_lock_bh(&mrt_lock);
1131 		c->mfc_parent = mfc->mfcc_parent;
1132 		ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1133 		if (!mrtsock)
1134 			c->mfc_flags |= MFC_STATIC;
1135 		write_unlock_bh(&mrt_lock);
1136 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1137 		return 0;
1138 	}
1139 
1140 	if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1141 	    !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1142 		return -EINVAL;
1143 
1144 	c = ipmr_cache_alloc();
1145 	if (!c)
1146 		return -ENOMEM;
1147 
1148 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1149 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1150 	c->mfc_parent = mfc->mfcc_parent;
1151 	ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1152 	if (!mrtsock)
1153 		c->mfc_flags |= MFC_STATIC;
1154 
1155 	list_add_rcu(&c->list, &mrt->mfc_cache_array[line]);
1156 
1157 	/* Check to see if we resolved a queued list. If so we
1158 	 * need to send on the frames and tidy up.
1159 	 */
1160 	found = false;
1161 	spin_lock_bh(&mfc_unres_lock);
1162 	list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1163 		if (uc->mfc_origin == c->mfc_origin &&
1164 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1165 			list_del(&uc->list);
1166 			atomic_dec(&mrt->cache_resolve_queue_len);
1167 			found = true;
1168 			break;
1169 		}
1170 	}
1171 	if (list_empty(&mrt->mfc_unres_queue))
1172 		del_timer(&mrt->ipmr_expire_timer);
1173 	spin_unlock_bh(&mfc_unres_lock);
1174 
1175 	if (found) {
1176 		ipmr_cache_resolve(net, mrt, uc, c);
1177 		ipmr_cache_free(uc);
1178 	}
1179 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1180 	return 0;
1181 }
1182 
1183 /* Close the multicast socket, and clear the vif tables etc */
1184 static void mroute_clean_tables(struct mr_table *mrt, bool all)
1185 {
1186 	int i;
1187 	LIST_HEAD(list);
1188 	struct mfc_cache *c, *next;
1189 
1190 	/* Shut down all active vif entries */
1191 	for (i = 0; i < mrt->maxvif; i++) {
1192 		if (!all && (mrt->vif_table[i].flags & VIFF_STATIC))
1193 			continue;
1194 		vif_delete(mrt, i, 0, &list);
1195 	}
1196 	unregister_netdevice_many(&list);
1197 
1198 	/* Wipe the cache */
1199 	for (i = 0; i < MFC_LINES; i++) {
1200 		list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[i], list) {
1201 			if (!all && (c->mfc_flags & MFC_STATIC))
1202 				continue;
1203 			list_del_rcu(&c->list);
1204 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1205 			ipmr_cache_free(c);
1206 		}
1207 	}
1208 
1209 	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1210 		spin_lock_bh(&mfc_unres_lock);
1211 		list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
1212 			list_del(&c->list);
1213 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1214 			ipmr_destroy_unres(mrt, c);
1215 		}
1216 		spin_unlock_bh(&mfc_unres_lock);
1217 	}
1218 }
1219 
1220 /* called from ip_ra_control(), before an RCU grace period,
1221  * we dont need to call synchronize_rcu() here
1222  */
1223 static void mrtsock_destruct(struct sock *sk)
1224 {
1225 	struct net *net = sock_net(sk);
1226 	struct mr_table *mrt;
1227 
1228 	rtnl_lock();
1229 	ipmr_for_each_table(mrt, net) {
1230 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1231 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1232 			inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1233 						    NETCONFA_IFINDEX_ALL,
1234 						    net->ipv4.devconf_all);
1235 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1236 			mroute_clean_tables(mrt, false);
1237 		}
1238 	}
1239 	rtnl_unlock();
1240 }
1241 
1242 /* Socket options and virtual interface manipulation. The whole
1243  * virtual interface system is a complete heap, but unfortunately
1244  * that's how BSD mrouted happens to think. Maybe one day with a proper
1245  * MOSPF/PIM router set up we can clean this up.
1246  */
1247 
1248 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
1249 			 unsigned int optlen)
1250 {
1251 	struct net *net = sock_net(sk);
1252 	int val, ret = 0, parent = 0;
1253 	struct mr_table *mrt;
1254 	struct vifctl vif;
1255 	struct mfcctl mfc;
1256 	u32 uval;
1257 
1258 	/* There's one exception to the lock - MRT_DONE which needs to unlock */
1259 	rtnl_lock();
1260 	if (sk->sk_type != SOCK_RAW ||
1261 	    inet_sk(sk)->inet_num != IPPROTO_IGMP) {
1262 		ret = -EOPNOTSUPP;
1263 		goto out_unlock;
1264 	}
1265 
1266 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1267 	if (!mrt) {
1268 		ret = -ENOENT;
1269 		goto out_unlock;
1270 	}
1271 	if (optname != MRT_INIT) {
1272 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1273 		    !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
1274 			ret = -EACCES;
1275 			goto out_unlock;
1276 		}
1277 	}
1278 
1279 	switch (optname) {
1280 	case MRT_INIT:
1281 		if (optlen != sizeof(int)) {
1282 			ret = -EINVAL;
1283 			break;
1284 		}
1285 		if (rtnl_dereference(mrt->mroute_sk)) {
1286 			ret = -EADDRINUSE;
1287 			break;
1288 		}
1289 
1290 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1291 		if (ret == 0) {
1292 			rcu_assign_pointer(mrt->mroute_sk, sk);
1293 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1294 			inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1295 						    NETCONFA_IFINDEX_ALL,
1296 						    net->ipv4.devconf_all);
1297 		}
1298 		break;
1299 	case MRT_DONE:
1300 		if (sk != rcu_access_pointer(mrt->mroute_sk)) {
1301 			ret = -EACCES;
1302 		} else {
1303 			/* We need to unlock here because mrtsock_destruct takes
1304 			 * care of rtnl itself and we can't change that due to
1305 			 * the IP_ROUTER_ALERT setsockopt which runs without it.
1306 			 */
1307 			rtnl_unlock();
1308 			ret = ip_ra_control(sk, 0, NULL);
1309 			goto out;
1310 		}
1311 		break;
1312 	case MRT_ADD_VIF:
1313 	case MRT_DEL_VIF:
1314 		if (optlen != sizeof(vif)) {
1315 			ret = -EINVAL;
1316 			break;
1317 		}
1318 		if (copy_from_user(&vif, optval, sizeof(vif))) {
1319 			ret = -EFAULT;
1320 			break;
1321 		}
1322 		if (vif.vifc_vifi >= MAXVIFS) {
1323 			ret = -ENFILE;
1324 			break;
1325 		}
1326 		if (optname == MRT_ADD_VIF) {
1327 			ret = vif_add(net, mrt, &vif,
1328 				      sk == rtnl_dereference(mrt->mroute_sk));
1329 		} else {
1330 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1331 		}
1332 		break;
1333 	/* Manipulate the forwarding caches. These live
1334 	 * in a sort of kernel/user symbiosis.
1335 	 */
1336 	case MRT_ADD_MFC:
1337 	case MRT_DEL_MFC:
1338 		parent = -1;
1339 	case MRT_ADD_MFC_PROXY:
1340 	case MRT_DEL_MFC_PROXY:
1341 		if (optlen != sizeof(mfc)) {
1342 			ret = -EINVAL;
1343 			break;
1344 		}
1345 		if (copy_from_user(&mfc, optval, sizeof(mfc))) {
1346 			ret = -EFAULT;
1347 			break;
1348 		}
1349 		if (parent == 0)
1350 			parent = mfc.mfcc_parent;
1351 		if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1352 			ret = ipmr_mfc_delete(mrt, &mfc, parent);
1353 		else
1354 			ret = ipmr_mfc_add(net, mrt, &mfc,
1355 					   sk == rtnl_dereference(mrt->mroute_sk),
1356 					   parent);
1357 		break;
1358 	/* Control PIM assert. */
1359 	case MRT_ASSERT:
1360 		if (optlen != sizeof(val)) {
1361 			ret = -EINVAL;
1362 			break;
1363 		}
1364 		if (get_user(val, (int __user *)optval)) {
1365 			ret = -EFAULT;
1366 			break;
1367 		}
1368 		mrt->mroute_do_assert = val;
1369 		break;
1370 	case MRT_PIM:
1371 		if (!ipmr_pimsm_enabled()) {
1372 			ret = -ENOPROTOOPT;
1373 			break;
1374 		}
1375 		if (optlen != sizeof(val)) {
1376 			ret = -EINVAL;
1377 			break;
1378 		}
1379 		if (get_user(val, (int __user *)optval)) {
1380 			ret = -EFAULT;
1381 			break;
1382 		}
1383 
1384 		val = !!val;
1385 		if (val != mrt->mroute_do_pim) {
1386 			mrt->mroute_do_pim = val;
1387 			mrt->mroute_do_assert = val;
1388 		}
1389 		break;
1390 	case MRT_TABLE:
1391 		if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) {
1392 			ret = -ENOPROTOOPT;
1393 			break;
1394 		}
1395 		if (optlen != sizeof(uval)) {
1396 			ret = -EINVAL;
1397 			break;
1398 		}
1399 		if (get_user(uval, (u32 __user *)optval)) {
1400 			ret = -EFAULT;
1401 			break;
1402 		}
1403 
1404 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1405 			ret = -EBUSY;
1406 		} else {
1407 			mrt = ipmr_new_table(net, uval);
1408 			if (IS_ERR(mrt))
1409 				ret = PTR_ERR(mrt);
1410 			else
1411 				raw_sk(sk)->ipmr_table = uval;
1412 		}
1413 		break;
1414 	/* Spurious command, or MRT_VERSION which you cannot set. */
1415 	default:
1416 		ret = -ENOPROTOOPT;
1417 	}
1418 out_unlock:
1419 	rtnl_unlock();
1420 out:
1421 	return ret;
1422 }
1423 
1424 /* Getsock opt support for the multicast routing system. */
1425 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1426 {
1427 	int olr;
1428 	int val;
1429 	struct net *net = sock_net(sk);
1430 	struct mr_table *mrt;
1431 
1432 	if (sk->sk_type != SOCK_RAW ||
1433 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1434 		return -EOPNOTSUPP;
1435 
1436 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1437 	if (!mrt)
1438 		return -ENOENT;
1439 
1440 	switch (optname) {
1441 	case MRT_VERSION:
1442 		val = 0x0305;
1443 		break;
1444 	case MRT_PIM:
1445 		if (!ipmr_pimsm_enabled())
1446 			return -ENOPROTOOPT;
1447 		val = mrt->mroute_do_pim;
1448 		break;
1449 	case MRT_ASSERT:
1450 		val = mrt->mroute_do_assert;
1451 		break;
1452 	default:
1453 		return -ENOPROTOOPT;
1454 	}
1455 
1456 	if (get_user(olr, optlen))
1457 		return -EFAULT;
1458 	olr = min_t(unsigned int, olr, sizeof(int));
1459 	if (olr < 0)
1460 		return -EINVAL;
1461 	if (put_user(olr, optlen))
1462 		return -EFAULT;
1463 	if (copy_to_user(optval, &val, olr))
1464 		return -EFAULT;
1465 	return 0;
1466 }
1467 
1468 /* The IP multicast ioctl support routines. */
1469 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1470 {
1471 	struct sioc_sg_req sr;
1472 	struct sioc_vif_req vr;
1473 	struct vif_device *vif;
1474 	struct mfc_cache *c;
1475 	struct net *net = sock_net(sk);
1476 	struct mr_table *mrt;
1477 
1478 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1479 	if (!mrt)
1480 		return -ENOENT;
1481 
1482 	switch (cmd) {
1483 	case SIOCGETVIFCNT:
1484 		if (copy_from_user(&vr, arg, sizeof(vr)))
1485 			return -EFAULT;
1486 		if (vr.vifi >= mrt->maxvif)
1487 			return -EINVAL;
1488 		read_lock(&mrt_lock);
1489 		vif = &mrt->vif_table[vr.vifi];
1490 		if (VIF_EXISTS(mrt, vr.vifi)) {
1491 			vr.icount = vif->pkt_in;
1492 			vr.ocount = vif->pkt_out;
1493 			vr.ibytes = vif->bytes_in;
1494 			vr.obytes = vif->bytes_out;
1495 			read_unlock(&mrt_lock);
1496 
1497 			if (copy_to_user(arg, &vr, sizeof(vr)))
1498 				return -EFAULT;
1499 			return 0;
1500 		}
1501 		read_unlock(&mrt_lock);
1502 		return -EADDRNOTAVAIL;
1503 	case SIOCGETSGCNT:
1504 		if (copy_from_user(&sr, arg, sizeof(sr)))
1505 			return -EFAULT;
1506 
1507 		rcu_read_lock();
1508 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1509 		if (c) {
1510 			sr.pktcnt = c->mfc_un.res.pkt;
1511 			sr.bytecnt = c->mfc_un.res.bytes;
1512 			sr.wrong_if = c->mfc_un.res.wrong_if;
1513 			rcu_read_unlock();
1514 
1515 			if (copy_to_user(arg, &sr, sizeof(sr)))
1516 				return -EFAULT;
1517 			return 0;
1518 		}
1519 		rcu_read_unlock();
1520 		return -EADDRNOTAVAIL;
1521 	default:
1522 		return -ENOIOCTLCMD;
1523 	}
1524 }
1525 
1526 #ifdef CONFIG_COMPAT
1527 struct compat_sioc_sg_req {
1528 	struct in_addr src;
1529 	struct in_addr grp;
1530 	compat_ulong_t pktcnt;
1531 	compat_ulong_t bytecnt;
1532 	compat_ulong_t wrong_if;
1533 };
1534 
1535 struct compat_sioc_vif_req {
1536 	vifi_t	vifi;		/* Which iface */
1537 	compat_ulong_t icount;
1538 	compat_ulong_t ocount;
1539 	compat_ulong_t ibytes;
1540 	compat_ulong_t obytes;
1541 };
1542 
1543 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1544 {
1545 	struct compat_sioc_sg_req sr;
1546 	struct compat_sioc_vif_req vr;
1547 	struct vif_device *vif;
1548 	struct mfc_cache *c;
1549 	struct net *net = sock_net(sk);
1550 	struct mr_table *mrt;
1551 
1552 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1553 	if (!mrt)
1554 		return -ENOENT;
1555 
1556 	switch (cmd) {
1557 	case SIOCGETVIFCNT:
1558 		if (copy_from_user(&vr, arg, sizeof(vr)))
1559 			return -EFAULT;
1560 		if (vr.vifi >= mrt->maxvif)
1561 			return -EINVAL;
1562 		read_lock(&mrt_lock);
1563 		vif = &mrt->vif_table[vr.vifi];
1564 		if (VIF_EXISTS(mrt, vr.vifi)) {
1565 			vr.icount = vif->pkt_in;
1566 			vr.ocount = vif->pkt_out;
1567 			vr.ibytes = vif->bytes_in;
1568 			vr.obytes = vif->bytes_out;
1569 			read_unlock(&mrt_lock);
1570 
1571 			if (copy_to_user(arg, &vr, sizeof(vr)))
1572 				return -EFAULT;
1573 			return 0;
1574 		}
1575 		read_unlock(&mrt_lock);
1576 		return -EADDRNOTAVAIL;
1577 	case SIOCGETSGCNT:
1578 		if (copy_from_user(&sr, arg, sizeof(sr)))
1579 			return -EFAULT;
1580 
1581 		rcu_read_lock();
1582 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1583 		if (c) {
1584 			sr.pktcnt = c->mfc_un.res.pkt;
1585 			sr.bytecnt = c->mfc_un.res.bytes;
1586 			sr.wrong_if = c->mfc_un.res.wrong_if;
1587 			rcu_read_unlock();
1588 
1589 			if (copy_to_user(arg, &sr, sizeof(sr)))
1590 				return -EFAULT;
1591 			return 0;
1592 		}
1593 		rcu_read_unlock();
1594 		return -EADDRNOTAVAIL;
1595 	default:
1596 		return -ENOIOCTLCMD;
1597 	}
1598 }
1599 #endif
1600 
1601 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1602 {
1603 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1604 	struct net *net = dev_net(dev);
1605 	struct mr_table *mrt;
1606 	struct vif_device *v;
1607 	int ct;
1608 
1609 	if (event != NETDEV_UNREGISTER)
1610 		return NOTIFY_DONE;
1611 
1612 	ipmr_for_each_table(mrt, net) {
1613 		v = &mrt->vif_table[0];
1614 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1615 			if (v->dev == dev)
1616 				vif_delete(mrt, ct, 1, NULL);
1617 		}
1618 	}
1619 	return NOTIFY_DONE;
1620 }
1621 
1622 static struct notifier_block ip_mr_notifier = {
1623 	.notifier_call = ipmr_device_event,
1624 };
1625 
1626 /* Encapsulate a packet by attaching a valid IPIP header to it.
1627  * This avoids tunnel drivers and other mess and gives us the speed so
1628  * important for multicast video.
1629  */
1630 static void ip_encap(struct net *net, struct sk_buff *skb,
1631 		     __be32 saddr, __be32 daddr)
1632 {
1633 	struct iphdr *iph;
1634 	const struct iphdr *old_iph = ip_hdr(skb);
1635 
1636 	skb_push(skb, sizeof(struct iphdr));
1637 	skb->transport_header = skb->network_header;
1638 	skb_reset_network_header(skb);
1639 	iph = ip_hdr(skb);
1640 
1641 	iph->version	=	4;
1642 	iph->tos	=	old_iph->tos;
1643 	iph->ttl	=	old_iph->ttl;
1644 	iph->frag_off	=	0;
1645 	iph->daddr	=	daddr;
1646 	iph->saddr	=	saddr;
1647 	iph->protocol	=	IPPROTO_IPIP;
1648 	iph->ihl	=	5;
1649 	iph->tot_len	=	htons(skb->len);
1650 	ip_select_ident(net, skb, NULL);
1651 	ip_send_check(iph);
1652 
1653 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1654 	nf_reset(skb);
1655 }
1656 
1657 static inline int ipmr_forward_finish(struct net *net, struct sock *sk,
1658 				      struct sk_buff *skb)
1659 {
1660 	struct ip_options *opt = &(IPCB(skb)->opt);
1661 
1662 	IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
1663 	IP_ADD_STATS(net, IPSTATS_MIB_OUTOCTETS, skb->len);
1664 
1665 	if (unlikely(opt->optlen))
1666 		ip_forward_options(skb);
1667 
1668 	return dst_output(net, sk, skb);
1669 }
1670 
1671 /* Processing handlers for ipmr_forward */
1672 
1673 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1674 			    struct sk_buff *skb, struct mfc_cache *c, int vifi)
1675 {
1676 	const struct iphdr *iph = ip_hdr(skb);
1677 	struct vif_device *vif = &mrt->vif_table[vifi];
1678 	struct net_device *dev;
1679 	struct rtable *rt;
1680 	struct flowi4 fl4;
1681 	int    encap = 0;
1682 
1683 	if (!vif->dev)
1684 		goto out_free;
1685 
1686 	if (vif->flags & VIFF_REGISTER) {
1687 		vif->pkt_out++;
1688 		vif->bytes_out += skb->len;
1689 		vif->dev->stats.tx_bytes += skb->len;
1690 		vif->dev->stats.tx_packets++;
1691 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1692 		goto out_free;
1693 	}
1694 
1695 	if (vif->flags & VIFF_TUNNEL) {
1696 		rt = ip_route_output_ports(net, &fl4, NULL,
1697 					   vif->remote, vif->local,
1698 					   0, 0,
1699 					   IPPROTO_IPIP,
1700 					   RT_TOS(iph->tos), vif->link);
1701 		if (IS_ERR(rt))
1702 			goto out_free;
1703 		encap = sizeof(struct iphdr);
1704 	} else {
1705 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1706 					   0, 0,
1707 					   IPPROTO_IPIP,
1708 					   RT_TOS(iph->tos), vif->link);
1709 		if (IS_ERR(rt))
1710 			goto out_free;
1711 	}
1712 
1713 	dev = rt->dst.dev;
1714 
1715 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1716 		/* Do not fragment multicasts. Alas, IPv4 does not
1717 		 * allow to send ICMP, so that packets will disappear
1718 		 * to blackhole.
1719 		 */
1720 		IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
1721 		ip_rt_put(rt);
1722 		goto out_free;
1723 	}
1724 
1725 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1726 
1727 	if (skb_cow(skb, encap)) {
1728 		ip_rt_put(rt);
1729 		goto out_free;
1730 	}
1731 
1732 	vif->pkt_out++;
1733 	vif->bytes_out += skb->len;
1734 
1735 	skb_dst_drop(skb);
1736 	skb_dst_set(skb, &rt->dst);
1737 	ip_decrease_ttl(ip_hdr(skb));
1738 
1739 	/* FIXME: forward and output firewalls used to be called here.
1740 	 * What do we do with netfilter? -- RR
1741 	 */
1742 	if (vif->flags & VIFF_TUNNEL) {
1743 		ip_encap(net, skb, vif->local, vif->remote);
1744 		/* FIXME: extra output firewall step used to be here. --RR */
1745 		vif->dev->stats.tx_packets++;
1746 		vif->dev->stats.tx_bytes += skb->len;
1747 	}
1748 
1749 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1750 
1751 	/* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1752 	 * not only before forwarding, but after forwarding on all output
1753 	 * interfaces. It is clear, if mrouter runs a multicasting
1754 	 * program, it should receive packets not depending to what interface
1755 	 * program is joined.
1756 	 * If we will not make it, the program will have to join on all
1757 	 * interfaces. On the other hand, multihoming host (or router, but
1758 	 * not mrouter) cannot join to more than one interface - it will
1759 	 * result in receiving multiple packets.
1760 	 */
1761 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
1762 		net, NULL, skb, skb->dev, dev,
1763 		ipmr_forward_finish);
1764 	return;
1765 
1766 out_free:
1767 	kfree_skb(skb);
1768 }
1769 
1770 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1771 {
1772 	int ct;
1773 
1774 	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1775 		if (mrt->vif_table[ct].dev == dev)
1776 			break;
1777 	}
1778 	return ct;
1779 }
1780 
1781 /* "local" means that we should preserve one skb (for local delivery) */
1782 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
1783 			  struct sk_buff *skb, struct mfc_cache *cache,
1784 			  int local)
1785 {
1786 	int psend = -1;
1787 	int vif, ct;
1788 	int true_vifi = ipmr_find_vif(mrt, skb->dev);
1789 
1790 	vif = cache->mfc_parent;
1791 	cache->mfc_un.res.pkt++;
1792 	cache->mfc_un.res.bytes += skb->len;
1793 
1794 	if (cache->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
1795 		struct mfc_cache *cache_proxy;
1796 
1797 		/* For an (*,G) entry, we only check that the incomming
1798 		 * interface is part of the static tree.
1799 		 */
1800 		cache_proxy = ipmr_cache_find_any_parent(mrt, vif);
1801 		if (cache_proxy &&
1802 		    cache_proxy->mfc_un.res.ttls[true_vifi] < 255)
1803 			goto forward;
1804 	}
1805 
1806 	/* Wrong interface: drop packet and (maybe) send PIM assert. */
1807 	if (mrt->vif_table[vif].dev != skb->dev) {
1808 		if (rt_is_output_route(skb_rtable(skb))) {
1809 			/* It is our own packet, looped back.
1810 			 * Very complicated situation...
1811 			 *
1812 			 * The best workaround until routing daemons will be
1813 			 * fixed is not to redistribute packet, if it was
1814 			 * send through wrong interface. It means, that
1815 			 * multicast applications WILL NOT work for
1816 			 * (S,G), which have default multicast route pointing
1817 			 * to wrong oif. In any case, it is not a good
1818 			 * idea to use multicasting applications on router.
1819 			 */
1820 			goto dont_forward;
1821 		}
1822 
1823 		cache->mfc_un.res.wrong_if++;
1824 
1825 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
1826 		    /* pimsm uses asserts, when switching from RPT to SPT,
1827 		     * so that we cannot check that packet arrived on an oif.
1828 		     * It is bad, but otherwise we would need to move pretty
1829 		     * large chunk of pimd to kernel. Ough... --ANK
1830 		     */
1831 		    (mrt->mroute_do_pim ||
1832 		     cache->mfc_un.res.ttls[true_vifi] < 255) &&
1833 		    time_after(jiffies,
1834 			       cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1835 			cache->mfc_un.res.last_assert = jiffies;
1836 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1837 		}
1838 		goto dont_forward;
1839 	}
1840 
1841 forward:
1842 	mrt->vif_table[vif].pkt_in++;
1843 	mrt->vif_table[vif].bytes_in += skb->len;
1844 
1845 	/* Forward the frame */
1846 	if (cache->mfc_origin == htonl(INADDR_ANY) &&
1847 	    cache->mfc_mcastgrp == htonl(INADDR_ANY)) {
1848 		if (true_vifi >= 0 &&
1849 		    true_vifi != cache->mfc_parent &&
1850 		    ip_hdr(skb)->ttl >
1851 				cache->mfc_un.res.ttls[cache->mfc_parent]) {
1852 			/* It's an (*,*) entry and the packet is not coming from
1853 			 * the upstream: forward the packet to the upstream
1854 			 * only.
1855 			 */
1856 			psend = cache->mfc_parent;
1857 			goto last_forward;
1858 		}
1859 		goto dont_forward;
1860 	}
1861 	for (ct = cache->mfc_un.res.maxvif - 1;
1862 	     ct >= cache->mfc_un.res.minvif; ct--) {
1863 		/* For (*,G) entry, don't forward to the incoming interface */
1864 		if ((cache->mfc_origin != htonl(INADDR_ANY) ||
1865 		     ct != true_vifi) &&
1866 		    ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1867 			if (psend != -1) {
1868 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1869 
1870 				if (skb2)
1871 					ipmr_queue_xmit(net, mrt, skb2, cache,
1872 							psend);
1873 			}
1874 			psend = ct;
1875 		}
1876 	}
1877 last_forward:
1878 	if (psend != -1) {
1879 		if (local) {
1880 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1881 
1882 			if (skb2)
1883 				ipmr_queue_xmit(net, mrt, skb2, cache, psend);
1884 		} else {
1885 			ipmr_queue_xmit(net, mrt, skb, cache, psend);
1886 			return;
1887 		}
1888 	}
1889 
1890 dont_forward:
1891 	if (!local)
1892 		kfree_skb(skb);
1893 }
1894 
1895 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
1896 {
1897 	struct rtable *rt = skb_rtable(skb);
1898 	struct iphdr *iph = ip_hdr(skb);
1899 	struct flowi4 fl4 = {
1900 		.daddr = iph->daddr,
1901 		.saddr = iph->saddr,
1902 		.flowi4_tos = RT_TOS(iph->tos),
1903 		.flowi4_oif = (rt_is_output_route(rt) ?
1904 			       skb->dev->ifindex : 0),
1905 		.flowi4_iif = (rt_is_output_route(rt) ?
1906 			       LOOPBACK_IFINDEX :
1907 			       skb->dev->ifindex),
1908 		.flowi4_mark = skb->mark,
1909 	};
1910 	struct mr_table *mrt;
1911 	int err;
1912 
1913 	err = ipmr_fib_lookup(net, &fl4, &mrt);
1914 	if (err)
1915 		return ERR_PTR(err);
1916 	return mrt;
1917 }
1918 
1919 /* Multicast packets for forwarding arrive here
1920  * Called with rcu_read_lock();
1921  */
1922 int ip_mr_input(struct sk_buff *skb)
1923 {
1924 	struct mfc_cache *cache;
1925 	struct net *net = dev_net(skb->dev);
1926 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
1927 	struct mr_table *mrt;
1928 
1929 	/* Packet is looped back after forward, it should not be
1930 	 * forwarded second time, but still can be delivered locally.
1931 	 */
1932 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
1933 		goto dont_forward;
1934 
1935 	mrt = ipmr_rt_fib_lookup(net, skb);
1936 	if (IS_ERR(mrt)) {
1937 		kfree_skb(skb);
1938 		return PTR_ERR(mrt);
1939 	}
1940 	if (!local) {
1941 		if (IPCB(skb)->opt.router_alert) {
1942 			if (ip_call_ra_chain(skb))
1943 				return 0;
1944 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
1945 			/* IGMPv1 (and broken IGMPv2 implementations sort of
1946 			 * Cisco IOS <= 11.2(8)) do not put router alert
1947 			 * option to IGMP packets destined to routable
1948 			 * groups. It is very bad, because it means
1949 			 * that we can forward NO IGMP messages.
1950 			 */
1951 			struct sock *mroute_sk;
1952 
1953 			mroute_sk = rcu_dereference(mrt->mroute_sk);
1954 			if (mroute_sk) {
1955 				nf_reset(skb);
1956 				raw_rcv(mroute_sk, skb);
1957 				return 0;
1958 			}
1959 		    }
1960 	}
1961 
1962 	/* already under rcu_read_lock() */
1963 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
1964 	if (!cache) {
1965 		int vif = ipmr_find_vif(mrt, skb->dev);
1966 
1967 		if (vif >= 0)
1968 			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
1969 						    vif);
1970 	}
1971 
1972 	/* No usable cache entry */
1973 	if (!cache) {
1974 		int vif;
1975 
1976 		if (local) {
1977 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1978 			ip_local_deliver(skb);
1979 			if (!skb2)
1980 				return -ENOBUFS;
1981 			skb = skb2;
1982 		}
1983 
1984 		read_lock(&mrt_lock);
1985 		vif = ipmr_find_vif(mrt, skb->dev);
1986 		if (vif >= 0) {
1987 			int err2 = ipmr_cache_unresolved(mrt, vif, skb);
1988 			read_unlock(&mrt_lock);
1989 
1990 			return err2;
1991 		}
1992 		read_unlock(&mrt_lock);
1993 		kfree_skb(skb);
1994 		return -ENODEV;
1995 	}
1996 
1997 	read_lock(&mrt_lock);
1998 	ip_mr_forward(net, mrt, skb, cache, local);
1999 	read_unlock(&mrt_lock);
2000 
2001 	if (local)
2002 		return ip_local_deliver(skb);
2003 
2004 	return 0;
2005 
2006 dont_forward:
2007 	if (local)
2008 		return ip_local_deliver(skb);
2009 	kfree_skb(skb);
2010 	return 0;
2011 }
2012 
2013 #ifdef CONFIG_IP_PIMSM_V1
2014 /* Handle IGMP messages of PIMv1 */
2015 int pim_rcv_v1(struct sk_buff *skb)
2016 {
2017 	struct igmphdr *pim;
2018 	struct net *net = dev_net(skb->dev);
2019 	struct mr_table *mrt;
2020 
2021 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2022 		goto drop;
2023 
2024 	pim = igmp_hdr(skb);
2025 
2026 	mrt = ipmr_rt_fib_lookup(net, skb);
2027 	if (IS_ERR(mrt))
2028 		goto drop;
2029 	if (!mrt->mroute_do_pim ||
2030 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2031 		goto drop;
2032 
2033 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2034 drop:
2035 		kfree_skb(skb);
2036 	}
2037 	return 0;
2038 }
2039 #endif
2040 
2041 #ifdef CONFIG_IP_PIMSM_V2
2042 static int pim_rcv(struct sk_buff *skb)
2043 {
2044 	struct pimreghdr *pim;
2045 	struct net *net = dev_net(skb->dev);
2046 	struct mr_table *mrt;
2047 
2048 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2049 		goto drop;
2050 
2051 	pim = (struct pimreghdr *)skb_transport_header(skb);
2052 	if (pim->type != ((PIM_VERSION << 4) | (PIM_REGISTER)) ||
2053 	    (pim->flags & PIM_NULL_REGISTER) ||
2054 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2055 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2056 		goto drop;
2057 
2058 	mrt = ipmr_rt_fib_lookup(net, skb);
2059 	if (IS_ERR(mrt))
2060 		goto drop;
2061 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2062 drop:
2063 		kfree_skb(skb);
2064 	}
2065 	return 0;
2066 }
2067 #endif
2068 
2069 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2070 			      struct mfc_cache *c, struct rtmsg *rtm)
2071 {
2072 	int ct;
2073 	struct rtnexthop *nhp;
2074 	struct nlattr *mp_attr;
2075 	struct rta_mfc_stats mfcs;
2076 
2077 	/* If cache is unresolved, don't try to parse IIF and OIF */
2078 	if (c->mfc_parent >= MAXVIFS)
2079 		return -ENOENT;
2080 
2081 	if (VIF_EXISTS(mrt, c->mfc_parent) &&
2082 	    nla_put_u32(skb, RTA_IIF, mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
2083 		return -EMSGSIZE;
2084 
2085 	if (!(mp_attr = nla_nest_start(skb, RTA_MULTIPATH)))
2086 		return -EMSGSIZE;
2087 
2088 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
2089 		if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
2090 			if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp)))) {
2091 				nla_nest_cancel(skb, mp_attr);
2092 				return -EMSGSIZE;
2093 			}
2094 
2095 			nhp->rtnh_flags = 0;
2096 			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
2097 			nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
2098 			nhp->rtnh_len = sizeof(*nhp);
2099 		}
2100 	}
2101 
2102 	nla_nest_end(skb, mp_attr);
2103 
2104 	mfcs.mfcs_packets = c->mfc_un.res.pkt;
2105 	mfcs.mfcs_bytes = c->mfc_un.res.bytes;
2106 	mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
2107 	if (nla_put(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs) < 0)
2108 		return -EMSGSIZE;
2109 
2110 	rtm->rtm_type = RTN_MULTICAST;
2111 	return 1;
2112 }
2113 
2114 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2115 		   __be32 saddr, __be32 daddr,
2116 		   struct rtmsg *rtm, int nowait)
2117 {
2118 	struct mfc_cache *cache;
2119 	struct mr_table *mrt;
2120 	int err;
2121 
2122 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2123 	if (!mrt)
2124 		return -ENOENT;
2125 
2126 	rcu_read_lock();
2127 	cache = ipmr_cache_find(mrt, saddr, daddr);
2128 	if (!cache && skb->dev) {
2129 		int vif = ipmr_find_vif(mrt, skb->dev);
2130 
2131 		if (vif >= 0)
2132 			cache = ipmr_cache_find_any(mrt, daddr, vif);
2133 	}
2134 	if (!cache) {
2135 		struct sk_buff *skb2;
2136 		struct iphdr *iph;
2137 		struct net_device *dev;
2138 		int vif = -1;
2139 
2140 		if (nowait) {
2141 			rcu_read_unlock();
2142 			return -EAGAIN;
2143 		}
2144 
2145 		dev = skb->dev;
2146 		read_lock(&mrt_lock);
2147 		if (dev)
2148 			vif = ipmr_find_vif(mrt, dev);
2149 		if (vif < 0) {
2150 			read_unlock(&mrt_lock);
2151 			rcu_read_unlock();
2152 			return -ENODEV;
2153 		}
2154 		skb2 = skb_clone(skb, GFP_ATOMIC);
2155 		if (!skb2) {
2156 			read_unlock(&mrt_lock);
2157 			rcu_read_unlock();
2158 			return -ENOMEM;
2159 		}
2160 
2161 		skb_push(skb2, sizeof(struct iphdr));
2162 		skb_reset_network_header(skb2);
2163 		iph = ip_hdr(skb2);
2164 		iph->ihl = sizeof(struct iphdr) >> 2;
2165 		iph->saddr = saddr;
2166 		iph->daddr = daddr;
2167 		iph->version = 0;
2168 		err = ipmr_cache_unresolved(mrt, vif, skb2);
2169 		read_unlock(&mrt_lock);
2170 		rcu_read_unlock();
2171 		return err;
2172 	}
2173 
2174 	read_lock(&mrt_lock);
2175 	err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2176 	read_unlock(&mrt_lock);
2177 	rcu_read_unlock();
2178 	return err;
2179 }
2180 
2181 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2182 			    u32 portid, u32 seq, struct mfc_cache *c, int cmd,
2183 			    int flags)
2184 {
2185 	struct nlmsghdr *nlh;
2186 	struct rtmsg *rtm;
2187 	int err;
2188 
2189 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2190 	if (!nlh)
2191 		return -EMSGSIZE;
2192 
2193 	rtm = nlmsg_data(nlh);
2194 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2195 	rtm->rtm_dst_len  = 32;
2196 	rtm->rtm_src_len  = 32;
2197 	rtm->rtm_tos      = 0;
2198 	rtm->rtm_table    = mrt->id;
2199 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2200 		goto nla_put_failure;
2201 	rtm->rtm_type     = RTN_MULTICAST;
2202 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2203 	if (c->mfc_flags & MFC_STATIC)
2204 		rtm->rtm_protocol = RTPROT_STATIC;
2205 	else
2206 		rtm->rtm_protocol = RTPROT_MROUTED;
2207 	rtm->rtm_flags    = 0;
2208 
2209 	if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
2210 	    nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
2211 		goto nla_put_failure;
2212 	err = __ipmr_fill_mroute(mrt, skb, c, rtm);
2213 	/* do not break the dump if cache is unresolved */
2214 	if (err < 0 && err != -ENOENT)
2215 		goto nla_put_failure;
2216 
2217 	nlmsg_end(skb, nlh);
2218 	return 0;
2219 
2220 nla_put_failure:
2221 	nlmsg_cancel(skb, nlh);
2222 	return -EMSGSIZE;
2223 }
2224 
2225 static size_t mroute_msgsize(bool unresolved, int maxvif)
2226 {
2227 	size_t len =
2228 		NLMSG_ALIGN(sizeof(struct rtmsg))
2229 		+ nla_total_size(4)	/* RTA_TABLE */
2230 		+ nla_total_size(4)	/* RTA_SRC */
2231 		+ nla_total_size(4)	/* RTA_DST */
2232 		;
2233 
2234 	if (!unresolved)
2235 		len = len
2236 		      + nla_total_size(4)	/* RTA_IIF */
2237 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2238 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2239 						/* RTA_MFC_STATS */
2240 		      + nla_total_size(sizeof(struct rta_mfc_stats))
2241 		;
2242 
2243 	return len;
2244 }
2245 
2246 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2247 				 int cmd)
2248 {
2249 	struct net *net = read_pnet(&mrt->net);
2250 	struct sk_buff *skb;
2251 	int err = -ENOBUFS;
2252 
2253 	skb = nlmsg_new(mroute_msgsize(mfc->mfc_parent >= MAXVIFS, mrt->maxvif),
2254 			GFP_ATOMIC);
2255 	if (!skb)
2256 		goto errout;
2257 
2258 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2259 	if (err < 0)
2260 		goto errout;
2261 
2262 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2263 	return;
2264 
2265 errout:
2266 	kfree_skb(skb);
2267 	if (err < 0)
2268 		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2269 }
2270 
2271 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2272 {
2273 	struct net *net = sock_net(skb->sk);
2274 	struct mr_table *mrt;
2275 	struct mfc_cache *mfc;
2276 	unsigned int t = 0, s_t;
2277 	unsigned int h = 0, s_h;
2278 	unsigned int e = 0, s_e;
2279 
2280 	s_t = cb->args[0];
2281 	s_h = cb->args[1];
2282 	s_e = cb->args[2];
2283 
2284 	rcu_read_lock();
2285 	ipmr_for_each_table(mrt, net) {
2286 		if (t < s_t)
2287 			goto next_table;
2288 		if (t > s_t)
2289 			s_h = 0;
2290 		for (h = s_h; h < MFC_LINES; h++) {
2291 			list_for_each_entry_rcu(mfc, &mrt->mfc_cache_array[h], list) {
2292 				if (e < s_e)
2293 					goto next_entry;
2294 				if (ipmr_fill_mroute(mrt, skb,
2295 						     NETLINK_CB(cb->skb).portid,
2296 						     cb->nlh->nlmsg_seq,
2297 						     mfc, RTM_NEWROUTE,
2298 						     NLM_F_MULTI) < 0)
2299 					goto done;
2300 next_entry:
2301 				e++;
2302 			}
2303 			e = s_e = 0;
2304 		}
2305 		spin_lock_bh(&mfc_unres_lock);
2306 		list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
2307 			if (e < s_e)
2308 				goto next_entry2;
2309 			if (ipmr_fill_mroute(mrt, skb,
2310 					     NETLINK_CB(cb->skb).portid,
2311 					     cb->nlh->nlmsg_seq,
2312 					     mfc, RTM_NEWROUTE,
2313 					     NLM_F_MULTI) < 0) {
2314 				spin_unlock_bh(&mfc_unres_lock);
2315 				goto done;
2316 			}
2317 next_entry2:
2318 			e++;
2319 		}
2320 		spin_unlock_bh(&mfc_unres_lock);
2321 		e = s_e = 0;
2322 		s_h = 0;
2323 next_table:
2324 		t++;
2325 	}
2326 done:
2327 	rcu_read_unlock();
2328 
2329 	cb->args[2] = e;
2330 	cb->args[1] = h;
2331 	cb->args[0] = t;
2332 
2333 	return skb->len;
2334 }
2335 
2336 static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {
2337 	[RTA_SRC]	= { .type = NLA_U32 },
2338 	[RTA_DST]	= { .type = NLA_U32 },
2339 	[RTA_IIF]	= { .type = NLA_U32 },
2340 	[RTA_TABLE]	= { .type = NLA_U32 },
2341 	[RTA_MULTIPATH]	= { .len = sizeof(struct rtnexthop) },
2342 };
2343 
2344 static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol)
2345 {
2346 	switch (rtm_protocol) {
2347 	case RTPROT_STATIC:
2348 	case RTPROT_MROUTED:
2349 		return true;
2350 	}
2351 	return false;
2352 }
2353 
2354 static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc)
2355 {
2356 	struct rtnexthop *rtnh = nla_data(nla);
2357 	int remaining = nla_len(nla), vifi = 0;
2358 
2359 	while (rtnh_ok(rtnh, remaining)) {
2360 		mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops;
2361 		if (++vifi == MAXVIFS)
2362 			break;
2363 		rtnh = rtnh_next(rtnh, &remaining);
2364 	}
2365 
2366 	return remaining > 0 ? -EINVAL : vifi;
2367 }
2368 
2369 /* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */
2370 static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
2371 			    struct mfcctl *mfcc, int *mrtsock,
2372 			    struct mr_table **mrtret)
2373 {
2374 	struct net_device *dev = NULL;
2375 	u32 tblid = RT_TABLE_DEFAULT;
2376 	struct mr_table *mrt;
2377 	struct nlattr *attr;
2378 	struct rtmsg *rtm;
2379 	int ret, rem;
2380 
2381 	ret = nlmsg_validate(nlh, sizeof(*rtm), RTA_MAX, rtm_ipmr_policy);
2382 	if (ret < 0)
2383 		goto out;
2384 	rtm = nlmsg_data(nlh);
2385 
2386 	ret = -EINVAL;
2387 	if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 ||
2388 	    rtm->rtm_type != RTN_MULTICAST ||
2389 	    rtm->rtm_scope != RT_SCOPE_UNIVERSE ||
2390 	    !ipmr_rtm_validate_proto(rtm->rtm_protocol))
2391 		goto out;
2392 
2393 	memset(mfcc, 0, sizeof(*mfcc));
2394 	mfcc->mfcc_parent = -1;
2395 	ret = 0;
2396 	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) {
2397 		switch (nla_type(attr)) {
2398 		case RTA_SRC:
2399 			mfcc->mfcc_origin.s_addr = nla_get_be32(attr);
2400 			break;
2401 		case RTA_DST:
2402 			mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr);
2403 			break;
2404 		case RTA_IIF:
2405 			dev = __dev_get_by_index(net, nla_get_u32(attr));
2406 			if (!dev) {
2407 				ret = -ENODEV;
2408 				goto out;
2409 			}
2410 			break;
2411 		case RTA_MULTIPATH:
2412 			if (ipmr_nla_get_ttls(attr, mfcc) < 0) {
2413 				ret = -EINVAL;
2414 				goto out;
2415 			}
2416 			break;
2417 		case RTA_PREFSRC:
2418 			ret = 1;
2419 			break;
2420 		case RTA_TABLE:
2421 			tblid = nla_get_u32(attr);
2422 			break;
2423 		}
2424 	}
2425 	mrt = ipmr_get_table(net, tblid);
2426 	if (!mrt) {
2427 		ret = -ENOENT;
2428 		goto out;
2429 	}
2430 	*mrtret = mrt;
2431 	*mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0;
2432 	if (dev)
2433 		mfcc->mfcc_parent = ipmr_find_vif(mrt, dev);
2434 
2435 out:
2436 	return ret;
2437 }
2438 
2439 /* takes care of both newroute and delroute */
2440 static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh)
2441 {
2442 	struct net *net = sock_net(skb->sk);
2443 	int ret, mrtsock, parent;
2444 	struct mr_table *tbl;
2445 	struct mfcctl mfcc;
2446 
2447 	mrtsock = 0;
2448 	tbl = NULL;
2449 	ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl);
2450 	if (ret < 0)
2451 		return ret;
2452 
2453 	parent = ret ? mfcc.mfcc_parent : -1;
2454 	if (nlh->nlmsg_type == RTM_NEWROUTE)
2455 		return ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent);
2456 	else
2457 		return ipmr_mfc_delete(tbl, &mfcc, parent);
2458 }
2459 
2460 #ifdef CONFIG_PROC_FS
2461 /* The /proc interfaces to multicast routing :
2462  * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2463  */
2464 struct ipmr_vif_iter {
2465 	struct seq_net_private p;
2466 	struct mr_table *mrt;
2467 	int ct;
2468 };
2469 
2470 static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2471 					   struct ipmr_vif_iter *iter,
2472 					   loff_t pos)
2473 {
2474 	struct mr_table *mrt = iter->mrt;
2475 
2476 	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2477 		if (!VIF_EXISTS(mrt, iter->ct))
2478 			continue;
2479 		if (pos-- == 0)
2480 			return &mrt->vif_table[iter->ct];
2481 	}
2482 	return NULL;
2483 }
2484 
2485 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2486 	__acquires(mrt_lock)
2487 {
2488 	struct ipmr_vif_iter *iter = seq->private;
2489 	struct net *net = seq_file_net(seq);
2490 	struct mr_table *mrt;
2491 
2492 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2493 	if (!mrt)
2494 		return ERR_PTR(-ENOENT);
2495 
2496 	iter->mrt = mrt;
2497 
2498 	read_lock(&mrt_lock);
2499 	return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2500 		: SEQ_START_TOKEN;
2501 }
2502 
2503 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2504 {
2505 	struct ipmr_vif_iter *iter = seq->private;
2506 	struct net *net = seq_file_net(seq);
2507 	struct mr_table *mrt = iter->mrt;
2508 
2509 	++*pos;
2510 	if (v == SEQ_START_TOKEN)
2511 		return ipmr_vif_seq_idx(net, iter, 0);
2512 
2513 	while (++iter->ct < mrt->maxvif) {
2514 		if (!VIF_EXISTS(mrt, iter->ct))
2515 			continue;
2516 		return &mrt->vif_table[iter->ct];
2517 	}
2518 	return NULL;
2519 }
2520 
2521 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2522 	__releases(mrt_lock)
2523 {
2524 	read_unlock(&mrt_lock);
2525 }
2526 
2527 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2528 {
2529 	struct ipmr_vif_iter *iter = seq->private;
2530 	struct mr_table *mrt = iter->mrt;
2531 
2532 	if (v == SEQ_START_TOKEN) {
2533 		seq_puts(seq,
2534 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2535 	} else {
2536 		const struct vif_device *vif = v;
2537 		const char *name =  vif->dev ? vif->dev->name : "none";
2538 
2539 		seq_printf(seq,
2540 			   "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2541 			   vif - mrt->vif_table,
2542 			   name, vif->bytes_in, vif->pkt_in,
2543 			   vif->bytes_out, vif->pkt_out,
2544 			   vif->flags, vif->local, vif->remote);
2545 	}
2546 	return 0;
2547 }
2548 
2549 static const struct seq_operations ipmr_vif_seq_ops = {
2550 	.start = ipmr_vif_seq_start,
2551 	.next  = ipmr_vif_seq_next,
2552 	.stop  = ipmr_vif_seq_stop,
2553 	.show  = ipmr_vif_seq_show,
2554 };
2555 
2556 static int ipmr_vif_open(struct inode *inode, struct file *file)
2557 {
2558 	return seq_open_net(inode, file, &ipmr_vif_seq_ops,
2559 			    sizeof(struct ipmr_vif_iter));
2560 }
2561 
2562 static const struct file_operations ipmr_vif_fops = {
2563 	.owner	 = THIS_MODULE,
2564 	.open    = ipmr_vif_open,
2565 	.read    = seq_read,
2566 	.llseek  = seq_lseek,
2567 	.release = seq_release_net,
2568 };
2569 
2570 struct ipmr_mfc_iter {
2571 	struct seq_net_private p;
2572 	struct mr_table *mrt;
2573 	struct list_head *cache;
2574 	int ct;
2575 };
2576 
2577 
2578 static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
2579 					  struct ipmr_mfc_iter *it, loff_t pos)
2580 {
2581 	struct mr_table *mrt = it->mrt;
2582 	struct mfc_cache *mfc;
2583 
2584 	rcu_read_lock();
2585 	for (it->ct = 0; it->ct < MFC_LINES; it->ct++) {
2586 		it->cache = &mrt->mfc_cache_array[it->ct];
2587 		list_for_each_entry_rcu(mfc, it->cache, list)
2588 			if (pos-- == 0)
2589 				return mfc;
2590 	}
2591 	rcu_read_unlock();
2592 
2593 	spin_lock_bh(&mfc_unres_lock);
2594 	it->cache = &mrt->mfc_unres_queue;
2595 	list_for_each_entry(mfc, it->cache, list)
2596 		if (pos-- == 0)
2597 			return mfc;
2598 	spin_unlock_bh(&mfc_unres_lock);
2599 
2600 	it->cache = NULL;
2601 	return NULL;
2602 }
2603 
2604 
2605 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2606 {
2607 	struct ipmr_mfc_iter *it = seq->private;
2608 	struct net *net = seq_file_net(seq);
2609 	struct mr_table *mrt;
2610 
2611 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2612 	if (!mrt)
2613 		return ERR_PTR(-ENOENT);
2614 
2615 	it->mrt = mrt;
2616 	it->cache = NULL;
2617 	it->ct = 0;
2618 	return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
2619 		: SEQ_START_TOKEN;
2620 }
2621 
2622 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2623 {
2624 	struct mfc_cache *mfc = v;
2625 	struct ipmr_mfc_iter *it = seq->private;
2626 	struct net *net = seq_file_net(seq);
2627 	struct mr_table *mrt = it->mrt;
2628 
2629 	++*pos;
2630 
2631 	if (v == SEQ_START_TOKEN)
2632 		return ipmr_mfc_seq_idx(net, seq->private, 0);
2633 
2634 	if (mfc->list.next != it->cache)
2635 		return list_entry(mfc->list.next, struct mfc_cache, list);
2636 
2637 	if (it->cache == &mrt->mfc_unres_queue)
2638 		goto end_of_list;
2639 
2640 	BUG_ON(it->cache != &mrt->mfc_cache_array[it->ct]);
2641 
2642 	while (++it->ct < MFC_LINES) {
2643 		it->cache = &mrt->mfc_cache_array[it->ct];
2644 		if (list_empty(it->cache))
2645 			continue;
2646 		return list_first_entry(it->cache, struct mfc_cache, list);
2647 	}
2648 
2649 	/* exhausted cache_array, show unresolved */
2650 	rcu_read_unlock();
2651 	it->cache = &mrt->mfc_unres_queue;
2652 	it->ct = 0;
2653 
2654 	spin_lock_bh(&mfc_unres_lock);
2655 	if (!list_empty(it->cache))
2656 		return list_first_entry(it->cache, struct mfc_cache, list);
2657 
2658 end_of_list:
2659 	spin_unlock_bh(&mfc_unres_lock);
2660 	it->cache = NULL;
2661 
2662 	return NULL;
2663 }
2664 
2665 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
2666 {
2667 	struct ipmr_mfc_iter *it = seq->private;
2668 	struct mr_table *mrt = it->mrt;
2669 
2670 	if (it->cache == &mrt->mfc_unres_queue)
2671 		spin_unlock_bh(&mfc_unres_lock);
2672 	else if (it->cache == &mrt->mfc_cache_array[it->ct])
2673 		rcu_read_unlock();
2674 }
2675 
2676 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2677 {
2678 	int n;
2679 
2680 	if (v == SEQ_START_TOKEN) {
2681 		seq_puts(seq,
2682 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2683 	} else {
2684 		const struct mfc_cache *mfc = v;
2685 		const struct ipmr_mfc_iter *it = seq->private;
2686 		const struct mr_table *mrt = it->mrt;
2687 
2688 		seq_printf(seq, "%08X %08X %-3hd",
2689 			   (__force u32) mfc->mfc_mcastgrp,
2690 			   (__force u32) mfc->mfc_origin,
2691 			   mfc->mfc_parent);
2692 
2693 		if (it->cache != &mrt->mfc_unres_queue) {
2694 			seq_printf(seq, " %8lu %8lu %8lu",
2695 				   mfc->mfc_un.res.pkt,
2696 				   mfc->mfc_un.res.bytes,
2697 				   mfc->mfc_un.res.wrong_if);
2698 			for (n = mfc->mfc_un.res.minvif;
2699 			     n < mfc->mfc_un.res.maxvif; n++) {
2700 				if (VIF_EXISTS(mrt, n) &&
2701 				    mfc->mfc_un.res.ttls[n] < 255)
2702 					seq_printf(seq,
2703 					   " %2d:%-3d",
2704 					   n, mfc->mfc_un.res.ttls[n]);
2705 			}
2706 		} else {
2707 			/* unresolved mfc_caches don't contain
2708 			 * pkt, bytes and wrong_if values
2709 			 */
2710 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
2711 		}
2712 		seq_putc(seq, '\n');
2713 	}
2714 	return 0;
2715 }
2716 
2717 static const struct seq_operations ipmr_mfc_seq_ops = {
2718 	.start = ipmr_mfc_seq_start,
2719 	.next  = ipmr_mfc_seq_next,
2720 	.stop  = ipmr_mfc_seq_stop,
2721 	.show  = ipmr_mfc_seq_show,
2722 };
2723 
2724 static int ipmr_mfc_open(struct inode *inode, struct file *file)
2725 {
2726 	return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
2727 			    sizeof(struct ipmr_mfc_iter));
2728 }
2729 
2730 static const struct file_operations ipmr_mfc_fops = {
2731 	.owner	 = THIS_MODULE,
2732 	.open    = ipmr_mfc_open,
2733 	.read    = seq_read,
2734 	.llseek  = seq_lseek,
2735 	.release = seq_release_net,
2736 };
2737 #endif
2738 
2739 #ifdef CONFIG_IP_PIMSM_V2
2740 static const struct net_protocol pim_protocol = {
2741 	.handler	=	pim_rcv,
2742 	.netns_ok	=	1,
2743 };
2744 #endif
2745 
2746 /* Setup for IP multicast routing */
2747 static int __net_init ipmr_net_init(struct net *net)
2748 {
2749 	int err;
2750 
2751 	err = ipmr_rules_init(net);
2752 	if (err < 0)
2753 		goto fail;
2754 
2755 #ifdef CONFIG_PROC_FS
2756 	err = -ENOMEM;
2757 	if (!proc_create("ip_mr_vif", 0, net->proc_net, &ipmr_vif_fops))
2758 		goto proc_vif_fail;
2759 	if (!proc_create("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_fops))
2760 		goto proc_cache_fail;
2761 #endif
2762 	return 0;
2763 
2764 #ifdef CONFIG_PROC_FS
2765 proc_cache_fail:
2766 	remove_proc_entry("ip_mr_vif", net->proc_net);
2767 proc_vif_fail:
2768 	ipmr_rules_exit(net);
2769 #endif
2770 fail:
2771 	return err;
2772 }
2773 
2774 static void __net_exit ipmr_net_exit(struct net *net)
2775 {
2776 #ifdef CONFIG_PROC_FS
2777 	remove_proc_entry("ip_mr_cache", net->proc_net);
2778 	remove_proc_entry("ip_mr_vif", net->proc_net);
2779 #endif
2780 	ipmr_rules_exit(net);
2781 }
2782 
2783 static struct pernet_operations ipmr_net_ops = {
2784 	.init = ipmr_net_init,
2785 	.exit = ipmr_net_exit,
2786 };
2787 
2788 int __init ip_mr_init(void)
2789 {
2790 	int err;
2791 
2792 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
2793 				       sizeof(struct mfc_cache),
2794 				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
2795 				       NULL);
2796 
2797 	err = register_pernet_subsys(&ipmr_net_ops);
2798 	if (err)
2799 		goto reg_pernet_fail;
2800 
2801 	err = register_netdevice_notifier(&ip_mr_notifier);
2802 	if (err)
2803 		goto reg_notif_fail;
2804 #ifdef CONFIG_IP_PIMSM_V2
2805 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
2806 		pr_err("%s: can't add PIM protocol\n", __func__);
2807 		err = -EAGAIN;
2808 		goto add_proto_fail;
2809 	}
2810 #endif
2811 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
2812 		      NULL, ipmr_rtm_dumproute, NULL);
2813 	rtnl_register(RTNL_FAMILY_IPMR, RTM_NEWROUTE,
2814 		      ipmr_rtm_route, NULL, NULL);
2815 	rtnl_register(RTNL_FAMILY_IPMR, RTM_DELROUTE,
2816 		      ipmr_rtm_route, NULL, NULL);
2817 	return 0;
2818 
2819 #ifdef CONFIG_IP_PIMSM_V2
2820 add_proto_fail:
2821 	unregister_netdevice_notifier(&ip_mr_notifier);
2822 #endif
2823 reg_notif_fail:
2824 	unregister_pernet_subsys(&ipmr_net_ops);
2825 reg_pernet_fail:
2826 	kmem_cache_destroy(mrt_cachep);
2827 	return err;
2828 }
2829