xref: /openbmc/linux/net/ipv4/ipmr.c (revision 4f3db074)
1 /*
2  *	IP multicast routing support for mrouted 3.6/3.8
3  *
4  *		(c) 1995 Alan Cox, <alan@lxorguk.ukuu.org.uk>
5  *	  Linux Consultancy and Custom Driver Development
6  *
7  *	This program is free software; you can redistribute it and/or
8  *	modify it under the terms of the GNU General Public License
9  *	as published by the Free Software Foundation; either version
10  *	2 of the License, or (at your option) any later version.
11  *
12  *	Fixes:
13  *	Michael Chastain	:	Incorrect size of copying.
14  *	Alan Cox		:	Added the cache manager code
15  *	Alan Cox		:	Fixed the clone/copy bug and device race.
16  *	Mike McLagan		:	Routing by source
17  *	Malcolm Beattie		:	Buffer handling fixes.
18  *	Alexey Kuznetsov	:	Double buffer free and other fixes.
19  *	SVR Anand		:	Fixed several multicast bugs and problems.
20  *	Alexey Kuznetsov	:	Status, optimisations and more.
21  *	Brad Parker		:	Better behaviour on mrouted upcall
22  *					overflow.
23  *      Carlos Picoto           :       PIMv1 Support
24  *	Pavlin Ivanov Radoslavov:	PIMv2 Registers must checksum only PIM header
25  *					Relax this requirement to work with older peers.
26  *
27  */
28 
29 #include <asm/uaccess.h>
30 #include <linux/types.h>
31 #include <linux/capability.h>
32 #include <linux/errno.h>
33 #include <linux/timer.h>
34 #include <linux/mm.h>
35 #include <linux/kernel.h>
36 #include <linux/fcntl.h>
37 #include <linux/stat.h>
38 #include <linux/socket.h>
39 #include <linux/in.h>
40 #include <linux/inet.h>
41 #include <linux/netdevice.h>
42 #include <linux/inetdevice.h>
43 #include <linux/igmp.h>
44 #include <linux/proc_fs.h>
45 #include <linux/seq_file.h>
46 #include <linux/mroute.h>
47 #include <linux/init.h>
48 #include <linux/if_ether.h>
49 #include <linux/slab.h>
50 #include <net/net_namespace.h>
51 #include <net/ip.h>
52 #include <net/protocol.h>
53 #include <linux/skbuff.h>
54 #include <net/route.h>
55 #include <net/sock.h>
56 #include <net/icmp.h>
57 #include <net/udp.h>
58 #include <net/raw.h>
59 #include <linux/notifier.h>
60 #include <linux/if_arp.h>
61 #include <linux/netfilter_ipv4.h>
62 #include <linux/compat.h>
63 #include <linux/export.h>
64 #include <net/ip_tunnels.h>
65 #include <net/checksum.h>
66 #include <net/netlink.h>
67 #include <net/fib_rules.h>
68 #include <linux/netconf.h>
69 
70 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
71 #define CONFIG_IP_PIMSM	1
72 #endif
73 
74 struct mr_table {
75 	struct list_head	list;
76 	possible_net_t		net;
77 	u32			id;
78 	struct sock __rcu	*mroute_sk;
79 	struct timer_list	ipmr_expire_timer;
80 	struct list_head	mfc_unres_queue;
81 	struct list_head	mfc_cache_array[MFC_LINES];
82 	struct vif_device	vif_table[MAXVIFS];
83 	int			maxvif;
84 	atomic_t		cache_resolve_queue_len;
85 	bool			mroute_do_assert;
86 	bool			mroute_do_pim;
87 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
88 	int			mroute_reg_vif_num;
89 #endif
90 };
91 
92 struct ipmr_rule {
93 	struct fib_rule		common;
94 };
95 
96 struct ipmr_result {
97 	struct mr_table		*mrt;
98 };
99 
100 /* Big lock, protecting vif table, mrt cache and mroute socket state.
101  * Note that the changes are semaphored via rtnl_lock.
102  */
103 
104 static DEFINE_RWLOCK(mrt_lock);
105 
106 /*
107  *	Multicast router control variables
108  */
109 
110 #define VIF_EXISTS(_mrt, _idx) ((_mrt)->vif_table[_idx].dev != NULL)
111 
112 /* Special spinlock for queue of unresolved entries */
113 static DEFINE_SPINLOCK(mfc_unres_lock);
114 
115 /* We return to original Alan's scheme. Hash table of resolved
116  * entries is changed only in process context and protected
117  * with weak lock mrt_lock. Queue of unresolved entries is protected
118  * with strong spinlock mfc_unres_lock.
119  *
120  * In this case data path is free of exclusive locks at all.
121  */
122 
123 static struct kmem_cache *mrt_cachep __read_mostly;
124 
125 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
126 static void ipmr_free_table(struct mr_table *mrt);
127 
128 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
129 			  struct sk_buff *skb, struct mfc_cache *cache,
130 			  int local);
131 static int ipmr_cache_report(struct mr_table *mrt,
132 			     struct sk_buff *pkt, vifi_t vifi, int assert);
133 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
134 			      struct mfc_cache *c, struct rtmsg *rtm);
135 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
136 				 int cmd);
137 static void mroute_clean_tables(struct mr_table *mrt);
138 static void ipmr_expire_process(unsigned long arg);
139 
140 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
141 #define ipmr_for_each_table(mrt, net) \
142 	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
143 
144 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
145 {
146 	struct mr_table *mrt;
147 
148 	ipmr_for_each_table(mrt, net) {
149 		if (mrt->id == id)
150 			return mrt;
151 	}
152 	return NULL;
153 }
154 
155 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
156 			   struct mr_table **mrt)
157 {
158 	int err;
159 	struct ipmr_result res;
160 	struct fib_lookup_arg arg = {
161 		.result = &res,
162 		.flags = FIB_LOOKUP_NOREF,
163 	};
164 
165 	err = fib_rules_lookup(net->ipv4.mr_rules_ops,
166 			       flowi4_to_flowi(flp4), 0, &arg);
167 	if (err < 0)
168 		return err;
169 	*mrt = res.mrt;
170 	return 0;
171 }
172 
173 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
174 			    int flags, struct fib_lookup_arg *arg)
175 {
176 	struct ipmr_result *res = arg->result;
177 	struct mr_table *mrt;
178 
179 	switch (rule->action) {
180 	case FR_ACT_TO_TBL:
181 		break;
182 	case FR_ACT_UNREACHABLE:
183 		return -ENETUNREACH;
184 	case FR_ACT_PROHIBIT:
185 		return -EACCES;
186 	case FR_ACT_BLACKHOLE:
187 	default:
188 		return -EINVAL;
189 	}
190 
191 	mrt = ipmr_get_table(rule->fr_net, rule->table);
192 	if (!mrt)
193 		return -EAGAIN;
194 	res->mrt = mrt;
195 	return 0;
196 }
197 
198 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
199 {
200 	return 1;
201 }
202 
203 static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
204 	FRA_GENERIC_POLICY,
205 };
206 
207 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
208 			       struct fib_rule_hdr *frh, struct nlattr **tb)
209 {
210 	return 0;
211 }
212 
213 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
214 			     struct nlattr **tb)
215 {
216 	return 1;
217 }
218 
219 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
220 			  struct fib_rule_hdr *frh)
221 {
222 	frh->dst_len = 0;
223 	frh->src_len = 0;
224 	frh->tos     = 0;
225 	return 0;
226 }
227 
228 static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
229 	.family		= RTNL_FAMILY_IPMR,
230 	.rule_size	= sizeof(struct ipmr_rule),
231 	.addr_size	= sizeof(u32),
232 	.action		= ipmr_rule_action,
233 	.match		= ipmr_rule_match,
234 	.configure	= ipmr_rule_configure,
235 	.compare	= ipmr_rule_compare,
236 	.default_pref	= fib_default_rule_pref,
237 	.fill		= ipmr_rule_fill,
238 	.nlgroup	= RTNLGRP_IPV4_RULE,
239 	.policy		= ipmr_rule_policy,
240 	.owner		= THIS_MODULE,
241 };
242 
243 static int __net_init ipmr_rules_init(struct net *net)
244 {
245 	struct fib_rules_ops *ops;
246 	struct mr_table *mrt;
247 	int err;
248 
249 	ops = fib_rules_register(&ipmr_rules_ops_template, net);
250 	if (IS_ERR(ops))
251 		return PTR_ERR(ops);
252 
253 	INIT_LIST_HEAD(&net->ipv4.mr_tables);
254 
255 	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
256 	if (!mrt) {
257 		err = -ENOMEM;
258 		goto err1;
259 	}
260 
261 	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
262 	if (err < 0)
263 		goto err2;
264 
265 	net->ipv4.mr_rules_ops = ops;
266 	return 0;
267 
268 err2:
269 	ipmr_free_table(mrt);
270 err1:
271 	fib_rules_unregister(ops);
272 	return err;
273 }
274 
275 static void __net_exit ipmr_rules_exit(struct net *net)
276 {
277 	struct mr_table *mrt, *next;
278 
279 	rtnl_lock();
280 	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
281 		list_del(&mrt->list);
282 		ipmr_free_table(mrt);
283 	}
284 	fib_rules_unregister(net->ipv4.mr_rules_ops);
285 	rtnl_unlock();
286 }
287 #else
288 #define ipmr_for_each_table(mrt, net) \
289 	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
290 
291 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
292 {
293 	return net->ipv4.mrt;
294 }
295 
296 static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
297 			   struct mr_table **mrt)
298 {
299 	*mrt = net->ipv4.mrt;
300 	return 0;
301 }
302 
303 static int __net_init ipmr_rules_init(struct net *net)
304 {
305 	net->ipv4.mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
306 	return net->ipv4.mrt ? 0 : -ENOMEM;
307 }
308 
309 static void __net_exit ipmr_rules_exit(struct net *net)
310 {
311 	rtnl_lock();
312 	ipmr_free_table(net->ipv4.mrt);
313 	net->ipv4.mrt = NULL;
314 	rtnl_unlock();
315 }
316 #endif
317 
318 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
319 {
320 	struct mr_table *mrt;
321 	unsigned int i;
322 
323 	mrt = ipmr_get_table(net, id);
324 	if (mrt)
325 		return mrt;
326 
327 	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
328 	if (!mrt)
329 		return NULL;
330 	write_pnet(&mrt->net, net);
331 	mrt->id = id;
332 
333 	/* Forwarding cache */
334 	for (i = 0; i < MFC_LINES; i++)
335 		INIT_LIST_HEAD(&mrt->mfc_cache_array[i]);
336 
337 	INIT_LIST_HEAD(&mrt->mfc_unres_queue);
338 
339 	setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
340 		    (unsigned long)mrt);
341 
342 #ifdef CONFIG_IP_PIMSM
343 	mrt->mroute_reg_vif_num = -1;
344 #endif
345 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
346 	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
347 #endif
348 	return mrt;
349 }
350 
351 static void ipmr_free_table(struct mr_table *mrt)
352 {
353 	del_timer_sync(&mrt->ipmr_expire_timer);
354 	mroute_clean_tables(mrt);
355 	kfree(mrt);
356 }
357 
358 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
359 
360 static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
361 {
362 	struct net *net = dev_net(dev);
363 
364 	dev_close(dev);
365 
366 	dev = __dev_get_by_name(net, "tunl0");
367 	if (dev) {
368 		const struct net_device_ops *ops = dev->netdev_ops;
369 		struct ifreq ifr;
370 		struct ip_tunnel_parm p;
371 
372 		memset(&p, 0, sizeof(p));
373 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
374 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
375 		p.iph.version = 4;
376 		p.iph.ihl = 5;
377 		p.iph.protocol = IPPROTO_IPIP;
378 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
379 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
380 
381 		if (ops->ndo_do_ioctl) {
382 			mm_segment_t oldfs = get_fs();
383 
384 			set_fs(KERNEL_DS);
385 			ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
386 			set_fs(oldfs);
387 		}
388 	}
389 }
390 
391 static
392 struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
393 {
394 	struct net_device  *dev;
395 
396 	dev = __dev_get_by_name(net, "tunl0");
397 
398 	if (dev) {
399 		const struct net_device_ops *ops = dev->netdev_ops;
400 		int err;
401 		struct ifreq ifr;
402 		struct ip_tunnel_parm p;
403 		struct in_device  *in_dev;
404 
405 		memset(&p, 0, sizeof(p));
406 		p.iph.daddr = v->vifc_rmt_addr.s_addr;
407 		p.iph.saddr = v->vifc_lcl_addr.s_addr;
408 		p.iph.version = 4;
409 		p.iph.ihl = 5;
410 		p.iph.protocol = IPPROTO_IPIP;
411 		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
412 		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
413 
414 		if (ops->ndo_do_ioctl) {
415 			mm_segment_t oldfs = get_fs();
416 
417 			set_fs(KERNEL_DS);
418 			err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
419 			set_fs(oldfs);
420 		} else {
421 			err = -EOPNOTSUPP;
422 		}
423 		dev = NULL;
424 
425 		if (err == 0 &&
426 		    (dev = __dev_get_by_name(net, p.name)) != NULL) {
427 			dev->flags |= IFF_MULTICAST;
428 
429 			in_dev = __in_dev_get_rtnl(dev);
430 			if (!in_dev)
431 				goto failure;
432 
433 			ipv4_devconf_setall(in_dev);
434 			neigh_parms_data_state_setall(in_dev->arp_parms);
435 			IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
436 
437 			if (dev_open(dev))
438 				goto failure;
439 			dev_hold(dev);
440 		}
441 	}
442 	return dev;
443 
444 failure:
445 	/* allow the register to be completed before unregistering. */
446 	rtnl_unlock();
447 	rtnl_lock();
448 
449 	unregister_netdevice(dev);
450 	return NULL;
451 }
452 
453 #ifdef CONFIG_IP_PIMSM
454 
455 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
456 {
457 	struct net *net = dev_net(dev);
458 	struct mr_table *mrt;
459 	struct flowi4 fl4 = {
460 		.flowi4_oif	= dev->ifindex,
461 		.flowi4_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
462 		.flowi4_mark	= skb->mark,
463 	};
464 	int err;
465 
466 	err = ipmr_fib_lookup(net, &fl4, &mrt);
467 	if (err < 0) {
468 		kfree_skb(skb);
469 		return err;
470 	}
471 
472 	read_lock(&mrt_lock);
473 	dev->stats.tx_bytes += skb->len;
474 	dev->stats.tx_packets++;
475 	ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
476 	read_unlock(&mrt_lock);
477 	kfree_skb(skb);
478 	return NETDEV_TX_OK;
479 }
480 
481 static int reg_vif_get_iflink(const struct net_device *dev)
482 {
483 	return 0;
484 }
485 
486 static const struct net_device_ops reg_vif_netdev_ops = {
487 	.ndo_start_xmit	= reg_vif_xmit,
488 	.ndo_get_iflink = reg_vif_get_iflink,
489 };
490 
491 static void reg_vif_setup(struct net_device *dev)
492 {
493 	dev->type		= ARPHRD_PIMREG;
494 	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
495 	dev->flags		= IFF_NOARP;
496 	dev->netdev_ops		= &reg_vif_netdev_ops;
497 	dev->destructor		= free_netdev;
498 	dev->features		|= NETIF_F_NETNS_LOCAL;
499 }
500 
501 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
502 {
503 	struct net_device *dev;
504 	struct in_device *in_dev;
505 	char name[IFNAMSIZ];
506 
507 	if (mrt->id == RT_TABLE_DEFAULT)
508 		sprintf(name, "pimreg");
509 	else
510 		sprintf(name, "pimreg%u", mrt->id);
511 
512 	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
513 
514 	if (!dev)
515 		return NULL;
516 
517 	dev_net_set(dev, net);
518 
519 	if (register_netdevice(dev)) {
520 		free_netdev(dev);
521 		return NULL;
522 	}
523 
524 	rcu_read_lock();
525 	in_dev = __in_dev_get_rcu(dev);
526 	if (!in_dev) {
527 		rcu_read_unlock();
528 		goto failure;
529 	}
530 
531 	ipv4_devconf_setall(in_dev);
532 	neigh_parms_data_state_setall(in_dev->arp_parms);
533 	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
534 	rcu_read_unlock();
535 
536 	if (dev_open(dev))
537 		goto failure;
538 
539 	dev_hold(dev);
540 
541 	return dev;
542 
543 failure:
544 	/* allow the register to be completed before unregistering. */
545 	rtnl_unlock();
546 	rtnl_lock();
547 
548 	unregister_netdevice(dev);
549 	return NULL;
550 }
551 #endif
552 
553 /**
554  *	vif_delete - Delete a VIF entry
555  *	@notify: Set to 1, if the caller is a notifier_call
556  */
557 
558 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
559 		      struct list_head *head)
560 {
561 	struct vif_device *v;
562 	struct net_device *dev;
563 	struct in_device *in_dev;
564 
565 	if (vifi < 0 || vifi >= mrt->maxvif)
566 		return -EADDRNOTAVAIL;
567 
568 	v = &mrt->vif_table[vifi];
569 
570 	write_lock_bh(&mrt_lock);
571 	dev = v->dev;
572 	v->dev = NULL;
573 
574 	if (!dev) {
575 		write_unlock_bh(&mrt_lock);
576 		return -EADDRNOTAVAIL;
577 	}
578 
579 #ifdef CONFIG_IP_PIMSM
580 	if (vifi == mrt->mroute_reg_vif_num)
581 		mrt->mroute_reg_vif_num = -1;
582 #endif
583 
584 	if (vifi + 1 == mrt->maxvif) {
585 		int tmp;
586 
587 		for (tmp = vifi - 1; tmp >= 0; tmp--) {
588 			if (VIF_EXISTS(mrt, tmp))
589 				break;
590 		}
591 		mrt->maxvif = tmp+1;
592 	}
593 
594 	write_unlock_bh(&mrt_lock);
595 
596 	dev_set_allmulti(dev, -1);
597 
598 	in_dev = __in_dev_get_rtnl(dev);
599 	if (in_dev) {
600 		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
601 		inet_netconf_notify_devconf(dev_net(dev),
602 					    NETCONFA_MC_FORWARDING,
603 					    dev->ifindex, &in_dev->cnf);
604 		ip_rt_multicast_event(in_dev);
605 	}
606 
607 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
608 		unregister_netdevice_queue(dev, head);
609 
610 	dev_put(dev);
611 	return 0;
612 }
613 
614 static void ipmr_cache_free_rcu(struct rcu_head *head)
615 {
616 	struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
617 
618 	kmem_cache_free(mrt_cachep, c);
619 }
620 
621 static inline void ipmr_cache_free(struct mfc_cache *c)
622 {
623 	call_rcu(&c->rcu, ipmr_cache_free_rcu);
624 }
625 
626 /* Destroy an unresolved cache entry, killing queued skbs
627  * and reporting error to netlink readers.
628  */
629 
630 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
631 {
632 	struct net *net = read_pnet(&mrt->net);
633 	struct sk_buff *skb;
634 	struct nlmsgerr *e;
635 
636 	atomic_dec(&mrt->cache_resolve_queue_len);
637 
638 	while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
639 		if (ip_hdr(skb)->version == 0) {
640 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
641 			nlh->nlmsg_type = NLMSG_ERROR;
642 			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
643 			skb_trim(skb, nlh->nlmsg_len);
644 			e = nlmsg_data(nlh);
645 			e->error = -ETIMEDOUT;
646 			memset(&e->msg, 0, sizeof(e->msg));
647 
648 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
649 		} else {
650 			kfree_skb(skb);
651 		}
652 	}
653 
654 	ipmr_cache_free(c);
655 }
656 
657 
658 /* Timer process for the unresolved queue. */
659 
660 static void ipmr_expire_process(unsigned long arg)
661 {
662 	struct mr_table *mrt = (struct mr_table *)arg;
663 	unsigned long now;
664 	unsigned long expires;
665 	struct mfc_cache *c, *next;
666 
667 	if (!spin_trylock(&mfc_unres_lock)) {
668 		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
669 		return;
670 	}
671 
672 	if (list_empty(&mrt->mfc_unres_queue))
673 		goto out;
674 
675 	now = jiffies;
676 	expires = 10*HZ;
677 
678 	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
679 		if (time_after(c->mfc_un.unres.expires, now)) {
680 			unsigned long interval = c->mfc_un.unres.expires - now;
681 			if (interval < expires)
682 				expires = interval;
683 			continue;
684 		}
685 
686 		list_del(&c->list);
687 		mroute_netlink_event(mrt, c, RTM_DELROUTE);
688 		ipmr_destroy_unres(mrt, c);
689 	}
690 
691 	if (!list_empty(&mrt->mfc_unres_queue))
692 		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
693 
694 out:
695 	spin_unlock(&mfc_unres_lock);
696 }
697 
698 /* Fill oifs list. It is called under write locked mrt_lock. */
699 
700 static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
701 				   unsigned char *ttls)
702 {
703 	int vifi;
704 
705 	cache->mfc_un.res.minvif = MAXVIFS;
706 	cache->mfc_un.res.maxvif = 0;
707 	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
708 
709 	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
710 		if (VIF_EXISTS(mrt, vifi) &&
711 		    ttls[vifi] && ttls[vifi] < 255) {
712 			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
713 			if (cache->mfc_un.res.minvif > vifi)
714 				cache->mfc_un.res.minvif = vifi;
715 			if (cache->mfc_un.res.maxvif <= vifi)
716 				cache->mfc_un.res.maxvif = vifi + 1;
717 		}
718 	}
719 }
720 
721 static int vif_add(struct net *net, struct mr_table *mrt,
722 		   struct vifctl *vifc, int mrtsock)
723 {
724 	int vifi = vifc->vifc_vifi;
725 	struct vif_device *v = &mrt->vif_table[vifi];
726 	struct net_device *dev;
727 	struct in_device *in_dev;
728 	int err;
729 
730 	/* Is vif busy ? */
731 	if (VIF_EXISTS(mrt, vifi))
732 		return -EADDRINUSE;
733 
734 	switch (vifc->vifc_flags) {
735 #ifdef CONFIG_IP_PIMSM
736 	case VIFF_REGISTER:
737 		/*
738 		 * Special Purpose VIF in PIM
739 		 * All the packets will be sent to the daemon
740 		 */
741 		if (mrt->mroute_reg_vif_num >= 0)
742 			return -EADDRINUSE;
743 		dev = ipmr_reg_vif(net, mrt);
744 		if (!dev)
745 			return -ENOBUFS;
746 		err = dev_set_allmulti(dev, 1);
747 		if (err) {
748 			unregister_netdevice(dev);
749 			dev_put(dev);
750 			return err;
751 		}
752 		break;
753 #endif
754 	case VIFF_TUNNEL:
755 		dev = ipmr_new_tunnel(net, vifc);
756 		if (!dev)
757 			return -ENOBUFS;
758 		err = dev_set_allmulti(dev, 1);
759 		if (err) {
760 			ipmr_del_tunnel(dev, vifc);
761 			dev_put(dev);
762 			return err;
763 		}
764 		break;
765 
766 	case VIFF_USE_IFINDEX:
767 	case 0:
768 		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
769 			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
770 			if (dev && !__in_dev_get_rtnl(dev)) {
771 				dev_put(dev);
772 				return -EADDRNOTAVAIL;
773 			}
774 		} else {
775 			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
776 		}
777 		if (!dev)
778 			return -EADDRNOTAVAIL;
779 		err = dev_set_allmulti(dev, 1);
780 		if (err) {
781 			dev_put(dev);
782 			return err;
783 		}
784 		break;
785 	default:
786 		return -EINVAL;
787 	}
788 
789 	in_dev = __in_dev_get_rtnl(dev);
790 	if (!in_dev) {
791 		dev_put(dev);
792 		return -EADDRNOTAVAIL;
793 	}
794 	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
795 	inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING, dev->ifindex,
796 				    &in_dev->cnf);
797 	ip_rt_multicast_event(in_dev);
798 
799 	/* Fill in the VIF structures */
800 
801 	v->rate_limit = vifc->vifc_rate_limit;
802 	v->local = vifc->vifc_lcl_addr.s_addr;
803 	v->remote = vifc->vifc_rmt_addr.s_addr;
804 	v->flags = vifc->vifc_flags;
805 	if (!mrtsock)
806 		v->flags |= VIFF_STATIC;
807 	v->threshold = vifc->vifc_threshold;
808 	v->bytes_in = 0;
809 	v->bytes_out = 0;
810 	v->pkt_in = 0;
811 	v->pkt_out = 0;
812 	v->link = dev->ifindex;
813 	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
814 		v->link = dev_get_iflink(dev);
815 
816 	/* And finish update writing critical data */
817 	write_lock_bh(&mrt_lock);
818 	v->dev = dev;
819 #ifdef CONFIG_IP_PIMSM
820 	if (v->flags & VIFF_REGISTER)
821 		mrt->mroute_reg_vif_num = vifi;
822 #endif
823 	if (vifi+1 > mrt->maxvif)
824 		mrt->maxvif = vifi+1;
825 	write_unlock_bh(&mrt_lock);
826 	return 0;
827 }
828 
829 /* called with rcu_read_lock() */
830 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
831 					 __be32 origin,
832 					 __be32 mcastgrp)
833 {
834 	int line = MFC_HASH(mcastgrp, origin);
835 	struct mfc_cache *c;
836 
837 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list) {
838 		if (c->mfc_origin == origin && c->mfc_mcastgrp == mcastgrp)
839 			return c;
840 	}
841 	return NULL;
842 }
843 
844 /* Look for a (*,*,oif) entry */
845 static struct mfc_cache *ipmr_cache_find_any_parent(struct mr_table *mrt,
846 						    int vifi)
847 {
848 	int line = MFC_HASH(htonl(INADDR_ANY), htonl(INADDR_ANY));
849 	struct mfc_cache *c;
850 
851 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list)
852 		if (c->mfc_origin == htonl(INADDR_ANY) &&
853 		    c->mfc_mcastgrp == htonl(INADDR_ANY) &&
854 		    c->mfc_un.res.ttls[vifi] < 255)
855 			return c;
856 
857 	return NULL;
858 }
859 
860 /* Look for a (*,G) entry */
861 static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
862 					     __be32 mcastgrp, int vifi)
863 {
864 	int line = MFC_HASH(mcastgrp, htonl(INADDR_ANY));
865 	struct mfc_cache *c, *proxy;
866 
867 	if (mcastgrp == htonl(INADDR_ANY))
868 		goto skip;
869 
870 	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list)
871 		if (c->mfc_origin == htonl(INADDR_ANY) &&
872 		    c->mfc_mcastgrp == mcastgrp) {
873 			if (c->mfc_un.res.ttls[vifi] < 255)
874 				return c;
875 
876 			/* It's ok if the vifi is part of the static tree */
877 			proxy = ipmr_cache_find_any_parent(mrt,
878 							   c->mfc_parent);
879 			if (proxy && proxy->mfc_un.res.ttls[vifi] < 255)
880 				return c;
881 		}
882 
883 skip:
884 	return ipmr_cache_find_any_parent(mrt, vifi);
885 }
886 
887 /*
888  *	Allocate a multicast cache entry
889  */
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 /*
911  *	A cache entry has gone into a resolved state from queued
912  */
913 
914 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
915 			       struct mfc_cache *uc, struct mfc_cache *c)
916 {
917 	struct sk_buff *skb;
918 	struct nlmsgerr *e;
919 
920 	/* Play the pending entries through our router */
921 
922 	while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
923 		if (ip_hdr(skb)->version == 0) {
924 			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
925 
926 			if (__ipmr_fill_mroute(mrt, skb, c, nlmsg_data(nlh)) > 0) {
927 				nlh->nlmsg_len = skb_tail_pointer(skb) -
928 						 (u8 *)nlh;
929 			} else {
930 				nlh->nlmsg_type = NLMSG_ERROR;
931 				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
932 				skb_trim(skb, nlh->nlmsg_len);
933 				e = nlmsg_data(nlh);
934 				e->error = -EMSGSIZE;
935 				memset(&e->msg, 0, sizeof(e->msg));
936 			}
937 
938 			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
939 		} else {
940 			ip_mr_forward(net, mrt, skb, c, 0);
941 		}
942 	}
943 }
944 
945 /*
946  *	Bounce a cache query up to mrouted. We could use netlink for this but mrouted
947  *	expects the following bizarre scheme.
948  *
949  *	Called under mrt_lock.
950  */
951 
952 static int ipmr_cache_report(struct mr_table *mrt,
953 			     struct sk_buff *pkt, vifi_t vifi, int assert)
954 {
955 	struct sk_buff *skb;
956 	const int ihl = ip_hdrlen(pkt);
957 	struct igmphdr *igmp;
958 	struct igmpmsg *msg;
959 	struct sock *mroute_sk;
960 	int ret;
961 
962 #ifdef CONFIG_IP_PIMSM
963 	if (assert == IGMPMSG_WHOLEPKT)
964 		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
965 	else
966 #endif
967 		skb = alloc_skb(128, GFP_ATOMIC);
968 
969 	if (!skb)
970 		return -ENOBUFS;
971 
972 #ifdef CONFIG_IP_PIMSM
973 	if (assert == IGMPMSG_WHOLEPKT) {
974 		/* Ugly, but we have no choice with this interface.
975 		 * Duplicate old header, fix ihl, length etc.
976 		 * And all this only to mangle msg->im_msgtype and
977 		 * to set msg->im_mbz to "mbz" :-)
978 		 */
979 		skb_push(skb, sizeof(struct iphdr));
980 		skb_reset_network_header(skb);
981 		skb_reset_transport_header(skb);
982 		msg = (struct igmpmsg *)skb_network_header(skb);
983 		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
984 		msg->im_msgtype = IGMPMSG_WHOLEPKT;
985 		msg->im_mbz = 0;
986 		msg->im_vif = mrt->mroute_reg_vif_num;
987 		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
988 		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
989 					     sizeof(struct iphdr));
990 	} else
991 #endif
992 	{
993 
994 	/* Copy the IP header */
995 
996 	skb_set_network_header(skb, skb->len);
997 	skb_put(skb, ihl);
998 	skb_copy_to_linear_data(skb, pkt->data, ihl);
999 	ip_hdr(skb)->protocol = 0;	/* Flag to the kernel this is a route add */
1000 	msg = (struct igmpmsg *)skb_network_header(skb);
1001 	msg->im_vif = vifi;
1002 	skb_dst_set(skb, dst_clone(skb_dst(pkt)));
1003 
1004 	/* Add our header */
1005 
1006 	igmp = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
1007 	igmp->type	=
1008 	msg->im_msgtype = assert;
1009 	igmp->code	= 0;
1010 	ip_hdr(skb)->tot_len = htons(skb->len);		/* Fix the length */
1011 	skb->transport_header = skb->network_header;
1012 	}
1013 
1014 	rcu_read_lock();
1015 	mroute_sk = rcu_dereference(mrt->mroute_sk);
1016 	if (!mroute_sk) {
1017 		rcu_read_unlock();
1018 		kfree_skb(skb);
1019 		return -EINVAL;
1020 	}
1021 
1022 	/* Deliver to mrouted */
1023 
1024 	ret = sock_queue_rcv_skb(mroute_sk, skb);
1025 	rcu_read_unlock();
1026 	if (ret < 0) {
1027 		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1028 		kfree_skb(skb);
1029 	}
1030 
1031 	return ret;
1032 }
1033 
1034 /*
1035  *	Queue a packet for resolution. It gets locked cache entry!
1036  */
1037 
1038 static int
1039 ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi, struct sk_buff *skb)
1040 {
1041 	bool found = false;
1042 	int err;
1043 	struct mfc_cache *c;
1044 	const struct iphdr *iph = ip_hdr(skb);
1045 
1046 	spin_lock_bh(&mfc_unres_lock);
1047 	list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
1048 		if (c->mfc_mcastgrp == iph->daddr &&
1049 		    c->mfc_origin == iph->saddr) {
1050 			found = true;
1051 			break;
1052 		}
1053 	}
1054 
1055 	if (!found) {
1056 		/* Create a new entry if allowable */
1057 
1058 		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
1059 		    (c = ipmr_cache_alloc_unres()) == NULL) {
1060 			spin_unlock_bh(&mfc_unres_lock);
1061 
1062 			kfree_skb(skb);
1063 			return -ENOBUFS;
1064 		}
1065 
1066 		/* Fill in the new cache entry */
1067 
1068 		c->mfc_parent	= -1;
1069 		c->mfc_origin	= iph->saddr;
1070 		c->mfc_mcastgrp	= iph->daddr;
1071 
1072 		/* Reflect first query at mrouted. */
1073 
1074 		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1075 		if (err < 0) {
1076 			/* If the report failed throw the cache entry
1077 			   out - Brad Parker
1078 			 */
1079 			spin_unlock_bh(&mfc_unres_lock);
1080 
1081 			ipmr_cache_free(c);
1082 			kfree_skb(skb);
1083 			return err;
1084 		}
1085 
1086 		atomic_inc(&mrt->cache_resolve_queue_len);
1087 		list_add(&c->list, &mrt->mfc_unres_queue);
1088 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1089 
1090 		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1091 			mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1092 	}
1093 
1094 	/* See if we can append the packet */
1095 
1096 	if (c->mfc_un.unres.unresolved.qlen > 3) {
1097 		kfree_skb(skb);
1098 		err = -ENOBUFS;
1099 	} else {
1100 		skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1101 		err = 0;
1102 	}
1103 
1104 	spin_unlock_bh(&mfc_unres_lock);
1105 	return err;
1106 }
1107 
1108 /*
1109  *	MFC cache manipulation by user space mroute daemon
1110  */
1111 
1112 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1113 {
1114 	int line;
1115 	struct mfc_cache *c, *next;
1116 
1117 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1118 
1119 	list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[line], list) {
1120 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1121 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr &&
1122 		    (parent == -1 || parent == c->mfc_parent)) {
1123 			list_del_rcu(&c->list);
1124 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1125 			ipmr_cache_free(c);
1126 			return 0;
1127 		}
1128 	}
1129 	return -ENOENT;
1130 }
1131 
1132 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1133 			struct mfcctl *mfc, int mrtsock, int parent)
1134 {
1135 	bool found = false;
1136 	int line;
1137 	struct mfc_cache *uc, *c;
1138 
1139 	if (mfc->mfcc_parent >= MAXVIFS)
1140 		return -ENFILE;
1141 
1142 	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1143 
1144 	list_for_each_entry(c, &mrt->mfc_cache_array[line], list) {
1145 		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1146 		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr &&
1147 		    (parent == -1 || parent == c->mfc_parent)) {
1148 			found = true;
1149 			break;
1150 		}
1151 	}
1152 
1153 	if (found) {
1154 		write_lock_bh(&mrt_lock);
1155 		c->mfc_parent = mfc->mfcc_parent;
1156 		ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1157 		if (!mrtsock)
1158 			c->mfc_flags |= MFC_STATIC;
1159 		write_unlock_bh(&mrt_lock);
1160 		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1161 		return 0;
1162 	}
1163 
1164 	if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1165 	    !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1166 		return -EINVAL;
1167 
1168 	c = ipmr_cache_alloc();
1169 	if (!c)
1170 		return -ENOMEM;
1171 
1172 	c->mfc_origin = mfc->mfcc_origin.s_addr;
1173 	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1174 	c->mfc_parent = mfc->mfcc_parent;
1175 	ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1176 	if (!mrtsock)
1177 		c->mfc_flags |= MFC_STATIC;
1178 
1179 	list_add_rcu(&c->list, &mrt->mfc_cache_array[line]);
1180 
1181 	/*
1182 	 *	Check to see if we resolved a queued list. If so we
1183 	 *	need to send on the frames and tidy up.
1184 	 */
1185 	found = false;
1186 	spin_lock_bh(&mfc_unres_lock);
1187 	list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1188 		if (uc->mfc_origin == c->mfc_origin &&
1189 		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1190 			list_del(&uc->list);
1191 			atomic_dec(&mrt->cache_resolve_queue_len);
1192 			found = true;
1193 			break;
1194 		}
1195 	}
1196 	if (list_empty(&mrt->mfc_unres_queue))
1197 		del_timer(&mrt->ipmr_expire_timer);
1198 	spin_unlock_bh(&mfc_unres_lock);
1199 
1200 	if (found) {
1201 		ipmr_cache_resolve(net, mrt, uc, c);
1202 		ipmr_cache_free(uc);
1203 	}
1204 	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1205 	return 0;
1206 }
1207 
1208 /*
1209  *	Close the multicast socket, and clear the vif tables etc
1210  */
1211 
1212 static void mroute_clean_tables(struct mr_table *mrt)
1213 {
1214 	int i;
1215 	LIST_HEAD(list);
1216 	struct mfc_cache *c, *next;
1217 
1218 	/* Shut down all active vif entries */
1219 
1220 	for (i = 0; i < mrt->maxvif; i++) {
1221 		if (!(mrt->vif_table[i].flags & VIFF_STATIC))
1222 			vif_delete(mrt, i, 0, &list);
1223 	}
1224 	unregister_netdevice_many(&list);
1225 
1226 	/* Wipe the cache */
1227 
1228 	for (i = 0; i < MFC_LINES; i++) {
1229 		list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[i], list) {
1230 			if (c->mfc_flags & MFC_STATIC)
1231 				continue;
1232 			list_del_rcu(&c->list);
1233 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1234 			ipmr_cache_free(c);
1235 		}
1236 	}
1237 
1238 	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1239 		spin_lock_bh(&mfc_unres_lock);
1240 		list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
1241 			list_del(&c->list);
1242 			mroute_netlink_event(mrt, c, RTM_DELROUTE);
1243 			ipmr_destroy_unres(mrt, c);
1244 		}
1245 		spin_unlock_bh(&mfc_unres_lock);
1246 	}
1247 }
1248 
1249 /* called from ip_ra_control(), before an RCU grace period,
1250  * we dont need to call synchronize_rcu() here
1251  */
1252 static void mrtsock_destruct(struct sock *sk)
1253 {
1254 	struct net *net = sock_net(sk);
1255 	struct mr_table *mrt;
1256 
1257 	rtnl_lock();
1258 	ipmr_for_each_table(mrt, net) {
1259 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1260 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1261 			inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1262 						    NETCONFA_IFINDEX_ALL,
1263 						    net->ipv4.devconf_all);
1264 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1265 			mroute_clean_tables(mrt);
1266 		}
1267 	}
1268 	rtnl_unlock();
1269 }
1270 
1271 /*
1272  *	Socket options and virtual interface manipulation. The whole
1273  *	virtual interface system is a complete heap, but unfortunately
1274  *	that's how BSD mrouted happens to think. Maybe one day with a proper
1275  *	MOSPF/PIM router set up we can clean this up.
1276  */
1277 
1278 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen)
1279 {
1280 	int ret, parent = 0;
1281 	struct vifctl vif;
1282 	struct mfcctl mfc;
1283 	struct net *net = sock_net(sk);
1284 	struct mr_table *mrt;
1285 
1286 	if (sk->sk_type != SOCK_RAW ||
1287 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1288 		return -EOPNOTSUPP;
1289 
1290 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1291 	if (!mrt)
1292 		return -ENOENT;
1293 
1294 	if (optname != MRT_INIT) {
1295 		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1296 		    !ns_capable(net->user_ns, CAP_NET_ADMIN))
1297 			return -EACCES;
1298 	}
1299 
1300 	switch (optname) {
1301 	case MRT_INIT:
1302 		if (optlen != sizeof(int))
1303 			return -EINVAL;
1304 
1305 		rtnl_lock();
1306 		if (rtnl_dereference(mrt->mroute_sk)) {
1307 			rtnl_unlock();
1308 			return -EADDRINUSE;
1309 		}
1310 
1311 		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1312 		if (ret == 0) {
1313 			rcu_assign_pointer(mrt->mroute_sk, sk);
1314 			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1315 			inet_netconf_notify_devconf(net, NETCONFA_MC_FORWARDING,
1316 						    NETCONFA_IFINDEX_ALL,
1317 						    net->ipv4.devconf_all);
1318 		}
1319 		rtnl_unlock();
1320 		return ret;
1321 	case MRT_DONE:
1322 		if (sk != rcu_access_pointer(mrt->mroute_sk))
1323 			return -EACCES;
1324 		return ip_ra_control(sk, 0, NULL);
1325 	case MRT_ADD_VIF:
1326 	case MRT_DEL_VIF:
1327 		if (optlen != sizeof(vif))
1328 			return -EINVAL;
1329 		if (copy_from_user(&vif, optval, sizeof(vif)))
1330 			return -EFAULT;
1331 		if (vif.vifc_vifi >= MAXVIFS)
1332 			return -ENFILE;
1333 		rtnl_lock();
1334 		if (optname == MRT_ADD_VIF) {
1335 			ret = vif_add(net, mrt, &vif,
1336 				      sk == rtnl_dereference(mrt->mroute_sk));
1337 		} else {
1338 			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1339 		}
1340 		rtnl_unlock();
1341 		return ret;
1342 
1343 		/*
1344 		 *	Manipulate the forwarding caches. These live
1345 		 *	in a sort of kernel/user symbiosis.
1346 		 */
1347 	case MRT_ADD_MFC:
1348 	case MRT_DEL_MFC:
1349 		parent = -1;
1350 	case MRT_ADD_MFC_PROXY:
1351 	case MRT_DEL_MFC_PROXY:
1352 		if (optlen != sizeof(mfc))
1353 			return -EINVAL;
1354 		if (copy_from_user(&mfc, optval, sizeof(mfc)))
1355 			return -EFAULT;
1356 		if (parent == 0)
1357 			parent = mfc.mfcc_parent;
1358 		rtnl_lock();
1359 		if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1360 			ret = ipmr_mfc_delete(mrt, &mfc, parent);
1361 		else
1362 			ret = ipmr_mfc_add(net, mrt, &mfc,
1363 					   sk == rtnl_dereference(mrt->mroute_sk),
1364 					   parent);
1365 		rtnl_unlock();
1366 		return ret;
1367 		/*
1368 		 *	Control PIM assert.
1369 		 */
1370 	case MRT_ASSERT:
1371 	{
1372 		int v;
1373 		if (optlen != sizeof(v))
1374 			return -EINVAL;
1375 		if (get_user(v, (int __user *)optval))
1376 			return -EFAULT;
1377 		mrt->mroute_do_assert = v;
1378 		return 0;
1379 	}
1380 #ifdef CONFIG_IP_PIMSM
1381 	case MRT_PIM:
1382 	{
1383 		int v;
1384 
1385 		if (optlen != sizeof(v))
1386 			return -EINVAL;
1387 		if (get_user(v, (int __user *)optval))
1388 			return -EFAULT;
1389 		v = !!v;
1390 
1391 		rtnl_lock();
1392 		ret = 0;
1393 		if (v != mrt->mroute_do_pim) {
1394 			mrt->mroute_do_pim = v;
1395 			mrt->mroute_do_assert = v;
1396 		}
1397 		rtnl_unlock();
1398 		return ret;
1399 	}
1400 #endif
1401 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
1402 	case MRT_TABLE:
1403 	{
1404 		u32 v;
1405 
1406 		if (optlen != sizeof(u32))
1407 			return -EINVAL;
1408 		if (get_user(v, (u32 __user *)optval))
1409 			return -EFAULT;
1410 
1411 		/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
1412 		if (v != RT_TABLE_DEFAULT && v >= 1000000000)
1413 			return -EINVAL;
1414 
1415 		rtnl_lock();
1416 		ret = 0;
1417 		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1418 			ret = -EBUSY;
1419 		} else {
1420 			if (!ipmr_new_table(net, v))
1421 				ret = -ENOMEM;
1422 			else
1423 				raw_sk(sk)->ipmr_table = v;
1424 		}
1425 		rtnl_unlock();
1426 		return ret;
1427 	}
1428 #endif
1429 	/*
1430 	 *	Spurious command, or MRT_VERSION which you cannot
1431 	 *	set.
1432 	 */
1433 	default:
1434 		return -ENOPROTOOPT;
1435 	}
1436 }
1437 
1438 /*
1439  *	Getsock opt support for the multicast routing system.
1440  */
1441 
1442 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1443 {
1444 	int olr;
1445 	int val;
1446 	struct net *net = sock_net(sk);
1447 	struct mr_table *mrt;
1448 
1449 	if (sk->sk_type != SOCK_RAW ||
1450 	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1451 		return -EOPNOTSUPP;
1452 
1453 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1454 	if (!mrt)
1455 		return -ENOENT;
1456 
1457 	if (optname != MRT_VERSION &&
1458 #ifdef CONFIG_IP_PIMSM
1459 	   optname != MRT_PIM &&
1460 #endif
1461 	   optname != MRT_ASSERT)
1462 		return -ENOPROTOOPT;
1463 
1464 	if (get_user(olr, optlen))
1465 		return -EFAULT;
1466 
1467 	olr = min_t(unsigned int, olr, sizeof(int));
1468 	if (olr < 0)
1469 		return -EINVAL;
1470 
1471 	if (put_user(olr, optlen))
1472 		return -EFAULT;
1473 	if (optname == MRT_VERSION)
1474 		val = 0x0305;
1475 #ifdef CONFIG_IP_PIMSM
1476 	else if (optname == MRT_PIM)
1477 		val = mrt->mroute_do_pim;
1478 #endif
1479 	else
1480 		val = mrt->mroute_do_assert;
1481 	if (copy_to_user(optval, &val, olr))
1482 		return -EFAULT;
1483 	return 0;
1484 }
1485 
1486 /*
1487  *	The IP multicast ioctl support routines.
1488  */
1489 
1490 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1491 {
1492 	struct sioc_sg_req sr;
1493 	struct sioc_vif_req vr;
1494 	struct vif_device *vif;
1495 	struct mfc_cache *c;
1496 	struct net *net = sock_net(sk);
1497 	struct mr_table *mrt;
1498 
1499 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1500 	if (!mrt)
1501 		return -ENOENT;
1502 
1503 	switch (cmd) {
1504 	case SIOCGETVIFCNT:
1505 		if (copy_from_user(&vr, arg, sizeof(vr)))
1506 			return -EFAULT;
1507 		if (vr.vifi >= mrt->maxvif)
1508 			return -EINVAL;
1509 		read_lock(&mrt_lock);
1510 		vif = &mrt->vif_table[vr.vifi];
1511 		if (VIF_EXISTS(mrt, vr.vifi)) {
1512 			vr.icount = vif->pkt_in;
1513 			vr.ocount = vif->pkt_out;
1514 			vr.ibytes = vif->bytes_in;
1515 			vr.obytes = vif->bytes_out;
1516 			read_unlock(&mrt_lock);
1517 
1518 			if (copy_to_user(arg, &vr, sizeof(vr)))
1519 				return -EFAULT;
1520 			return 0;
1521 		}
1522 		read_unlock(&mrt_lock);
1523 		return -EADDRNOTAVAIL;
1524 	case SIOCGETSGCNT:
1525 		if (copy_from_user(&sr, arg, sizeof(sr)))
1526 			return -EFAULT;
1527 
1528 		rcu_read_lock();
1529 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1530 		if (c) {
1531 			sr.pktcnt = c->mfc_un.res.pkt;
1532 			sr.bytecnt = c->mfc_un.res.bytes;
1533 			sr.wrong_if = c->mfc_un.res.wrong_if;
1534 			rcu_read_unlock();
1535 
1536 			if (copy_to_user(arg, &sr, sizeof(sr)))
1537 				return -EFAULT;
1538 			return 0;
1539 		}
1540 		rcu_read_unlock();
1541 		return -EADDRNOTAVAIL;
1542 	default:
1543 		return -ENOIOCTLCMD;
1544 	}
1545 }
1546 
1547 #ifdef CONFIG_COMPAT
1548 struct compat_sioc_sg_req {
1549 	struct in_addr src;
1550 	struct in_addr grp;
1551 	compat_ulong_t pktcnt;
1552 	compat_ulong_t bytecnt;
1553 	compat_ulong_t wrong_if;
1554 };
1555 
1556 struct compat_sioc_vif_req {
1557 	vifi_t	vifi;		/* Which iface */
1558 	compat_ulong_t icount;
1559 	compat_ulong_t ocount;
1560 	compat_ulong_t ibytes;
1561 	compat_ulong_t obytes;
1562 };
1563 
1564 int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1565 {
1566 	struct compat_sioc_sg_req sr;
1567 	struct compat_sioc_vif_req vr;
1568 	struct vif_device *vif;
1569 	struct mfc_cache *c;
1570 	struct net *net = sock_net(sk);
1571 	struct mr_table *mrt;
1572 
1573 	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1574 	if (!mrt)
1575 		return -ENOENT;
1576 
1577 	switch (cmd) {
1578 	case SIOCGETVIFCNT:
1579 		if (copy_from_user(&vr, arg, sizeof(vr)))
1580 			return -EFAULT;
1581 		if (vr.vifi >= mrt->maxvif)
1582 			return -EINVAL;
1583 		read_lock(&mrt_lock);
1584 		vif = &mrt->vif_table[vr.vifi];
1585 		if (VIF_EXISTS(mrt, vr.vifi)) {
1586 			vr.icount = vif->pkt_in;
1587 			vr.ocount = vif->pkt_out;
1588 			vr.ibytes = vif->bytes_in;
1589 			vr.obytes = vif->bytes_out;
1590 			read_unlock(&mrt_lock);
1591 
1592 			if (copy_to_user(arg, &vr, sizeof(vr)))
1593 				return -EFAULT;
1594 			return 0;
1595 		}
1596 		read_unlock(&mrt_lock);
1597 		return -EADDRNOTAVAIL;
1598 	case SIOCGETSGCNT:
1599 		if (copy_from_user(&sr, arg, sizeof(sr)))
1600 			return -EFAULT;
1601 
1602 		rcu_read_lock();
1603 		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1604 		if (c) {
1605 			sr.pktcnt = c->mfc_un.res.pkt;
1606 			sr.bytecnt = c->mfc_un.res.bytes;
1607 			sr.wrong_if = c->mfc_un.res.wrong_if;
1608 			rcu_read_unlock();
1609 
1610 			if (copy_to_user(arg, &sr, sizeof(sr)))
1611 				return -EFAULT;
1612 			return 0;
1613 		}
1614 		rcu_read_unlock();
1615 		return -EADDRNOTAVAIL;
1616 	default:
1617 		return -ENOIOCTLCMD;
1618 	}
1619 }
1620 #endif
1621 
1622 
1623 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1624 {
1625 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1626 	struct net *net = dev_net(dev);
1627 	struct mr_table *mrt;
1628 	struct vif_device *v;
1629 	int ct;
1630 
1631 	if (event != NETDEV_UNREGISTER)
1632 		return NOTIFY_DONE;
1633 
1634 	ipmr_for_each_table(mrt, net) {
1635 		v = &mrt->vif_table[0];
1636 		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1637 			if (v->dev == dev)
1638 				vif_delete(mrt, ct, 1, NULL);
1639 		}
1640 	}
1641 	return NOTIFY_DONE;
1642 }
1643 
1644 
1645 static struct notifier_block ip_mr_notifier = {
1646 	.notifier_call = ipmr_device_event,
1647 };
1648 
1649 /*
1650  *	Encapsulate a packet by attaching a valid IPIP header to it.
1651  *	This avoids tunnel drivers and other mess and gives us the speed so
1652  *	important for multicast video.
1653  */
1654 
1655 static void ip_encap(struct net *net, struct sk_buff *skb,
1656 		     __be32 saddr, __be32 daddr)
1657 {
1658 	struct iphdr *iph;
1659 	const struct iphdr *old_iph = ip_hdr(skb);
1660 
1661 	skb_push(skb, sizeof(struct iphdr));
1662 	skb->transport_header = skb->network_header;
1663 	skb_reset_network_header(skb);
1664 	iph = ip_hdr(skb);
1665 
1666 	iph->version	=	4;
1667 	iph->tos	=	old_iph->tos;
1668 	iph->ttl	=	old_iph->ttl;
1669 	iph->frag_off	=	0;
1670 	iph->daddr	=	daddr;
1671 	iph->saddr	=	saddr;
1672 	iph->protocol	=	IPPROTO_IPIP;
1673 	iph->ihl	=	5;
1674 	iph->tot_len	=	htons(skb->len);
1675 	ip_select_ident(net, skb, NULL);
1676 	ip_send_check(iph);
1677 
1678 	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1679 	nf_reset(skb);
1680 }
1681 
1682 static inline int ipmr_forward_finish(struct sock *sk, struct sk_buff *skb)
1683 {
1684 	struct ip_options *opt = &(IPCB(skb)->opt);
1685 
1686 	IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
1687 	IP_ADD_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTOCTETS, skb->len);
1688 
1689 	if (unlikely(opt->optlen))
1690 		ip_forward_options(skb);
1691 
1692 	return dst_output_sk(sk, skb);
1693 }
1694 
1695 /*
1696  *	Processing handlers for ipmr_forward
1697  */
1698 
1699 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1700 			    struct sk_buff *skb, struct mfc_cache *c, int vifi)
1701 {
1702 	const struct iphdr *iph = ip_hdr(skb);
1703 	struct vif_device *vif = &mrt->vif_table[vifi];
1704 	struct net_device *dev;
1705 	struct rtable *rt;
1706 	struct flowi4 fl4;
1707 	int    encap = 0;
1708 
1709 	if (!vif->dev)
1710 		goto out_free;
1711 
1712 #ifdef CONFIG_IP_PIMSM
1713 	if (vif->flags & VIFF_REGISTER) {
1714 		vif->pkt_out++;
1715 		vif->bytes_out += skb->len;
1716 		vif->dev->stats.tx_bytes += skb->len;
1717 		vif->dev->stats.tx_packets++;
1718 		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1719 		goto out_free;
1720 	}
1721 #endif
1722 
1723 	if (vif->flags & VIFF_TUNNEL) {
1724 		rt = ip_route_output_ports(net, &fl4, NULL,
1725 					   vif->remote, vif->local,
1726 					   0, 0,
1727 					   IPPROTO_IPIP,
1728 					   RT_TOS(iph->tos), vif->link);
1729 		if (IS_ERR(rt))
1730 			goto out_free;
1731 		encap = sizeof(struct iphdr);
1732 	} else {
1733 		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1734 					   0, 0,
1735 					   IPPROTO_IPIP,
1736 					   RT_TOS(iph->tos), vif->link);
1737 		if (IS_ERR(rt))
1738 			goto out_free;
1739 	}
1740 
1741 	dev = rt->dst.dev;
1742 
1743 	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1744 		/* Do not fragment multicasts. Alas, IPv4 does not
1745 		 * allow to send ICMP, so that packets will disappear
1746 		 * to blackhole.
1747 		 */
1748 
1749 		IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
1750 		ip_rt_put(rt);
1751 		goto out_free;
1752 	}
1753 
1754 	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1755 
1756 	if (skb_cow(skb, encap)) {
1757 		ip_rt_put(rt);
1758 		goto out_free;
1759 	}
1760 
1761 	vif->pkt_out++;
1762 	vif->bytes_out += skb->len;
1763 
1764 	skb_dst_drop(skb);
1765 	skb_dst_set(skb, &rt->dst);
1766 	ip_decrease_ttl(ip_hdr(skb));
1767 
1768 	/* FIXME: forward and output firewalls used to be called here.
1769 	 * What do we do with netfilter? -- RR
1770 	 */
1771 	if (vif->flags & VIFF_TUNNEL) {
1772 		ip_encap(net, skb, vif->local, vif->remote);
1773 		/* FIXME: extra output firewall step used to be here. --RR */
1774 		vif->dev->stats.tx_packets++;
1775 		vif->dev->stats.tx_bytes += skb->len;
1776 	}
1777 
1778 	IPCB(skb)->flags |= IPSKB_FORWARDED;
1779 
1780 	/*
1781 	 * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1782 	 * not only before forwarding, but after forwarding on all output
1783 	 * interfaces. It is clear, if mrouter runs a multicasting
1784 	 * program, it should receive packets not depending to what interface
1785 	 * program is joined.
1786 	 * If we will not make it, the program will have to join on all
1787 	 * interfaces. On the other hand, multihoming host (or router, but
1788 	 * not mrouter) cannot join to more than one interface - it will
1789 	 * result in receiving multiple packets.
1790 	 */
1791 	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, NULL, skb,
1792 		skb->dev, dev,
1793 		ipmr_forward_finish);
1794 	return;
1795 
1796 out_free:
1797 	kfree_skb(skb);
1798 }
1799 
1800 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1801 {
1802 	int ct;
1803 
1804 	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1805 		if (mrt->vif_table[ct].dev == dev)
1806 			break;
1807 	}
1808 	return ct;
1809 }
1810 
1811 /* "local" means that we should preserve one skb (for local delivery) */
1812 
1813 static void ip_mr_forward(struct net *net, struct mr_table *mrt,
1814 			  struct sk_buff *skb, struct mfc_cache *cache,
1815 			  int local)
1816 {
1817 	int psend = -1;
1818 	int vif, ct;
1819 	int true_vifi = ipmr_find_vif(mrt, skb->dev);
1820 
1821 	vif = cache->mfc_parent;
1822 	cache->mfc_un.res.pkt++;
1823 	cache->mfc_un.res.bytes += skb->len;
1824 
1825 	if (cache->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
1826 		struct mfc_cache *cache_proxy;
1827 
1828 		/* For an (*,G) entry, we only check that the incomming
1829 		 * interface is part of the static tree.
1830 		 */
1831 		cache_proxy = ipmr_cache_find_any_parent(mrt, vif);
1832 		if (cache_proxy &&
1833 		    cache_proxy->mfc_un.res.ttls[true_vifi] < 255)
1834 			goto forward;
1835 	}
1836 
1837 	/*
1838 	 * Wrong interface: drop packet and (maybe) send PIM assert.
1839 	 */
1840 	if (mrt->vif_table[vif].dev != skb->dev) {
1841 		if (rt_is_output_route(skb_rtable(skb))) {
1842 			/* It is our own packet, looped back.
1843 			 * Very complicated situation...
1844 			 *
1845 			 * The best workaround until routing daemons will be
1846 			 * fixed is not to redistribute packet, if it was
1847 			 * send through wrong interface. It means, that
1848 			 * multicast applications WILL NOT work for
1849 			 * (S,G), which have default multicast route pointing
1850 			 * to wrong oif. In any case, it is not a good
1851 			 * idea to use multicasting applications on router.
1852 			 */
1853 			goto dont_forward;
1854 		}
1855 
1856 		cache->mfc_un.res.wrong_if++;
1857 
1858 		if (true_vifi >= 0 && mrt->mroute_do_assert &&
1859 		    /* pimsm uses asserts, when switching from RPT to SPT,
1860 		     * so that we cannot check that packet arrived on an oif.
1861 		     * It is bad, but otherwise we would need to move pretty
1862 		     * large chunk of pimd to kernel. Ough... --ANK
1863 		     */
1864 		    (mrt->mroute_do_pim ||
1865 		     cache->mfc_un.res.ttls[true_vifi] < 255) &&
1866 		    time_after(jiffies,
1867 			       cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1868 			cache->mfc_un.res.last_assert = jiffies;
1869 			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1870 		}
1871 		goto dont_forward;
1872 	}
1873 
1874 forward:
1875 	mrt->vif_table[vif].pkt_in++;
1876 	mrt->vif_table[vif].bytes_in += skb->len;
1877 
1878 	/*
1879 	 *	Forward the frame
1880 	 */
1881 	if (cache->mfc_origin == htonl(INADDR_ANY) &&
1882 	    cache->mfc_mcastgrp == htonl(INADDR_ANY)) {
1883 		if (true_vifi >= 0 &&
1884 		    true_vifi != cache->mfc_parent &&
1885 		    ip_hdr(skb)->ttl >
1886 				cache->mfc_un.res.ttls[cache->mfc_parent]) {
1887 			/* It's an (*,*) entry and the packet is not coming from
1888 			 * the upstream: forward the packet to the upstream
1889 			 * only.
1890 			 */
1891 			psend = cache->mfc_parent;
1892 			goto last_forward;
1893 		}
1894 		goto dont_forward;
1895 	}
1896 	for (ct = cache->mfc_un.res.maxvif - 1;
1897 	     ct >= cache->mfc_un.res.minvif; ct--) {
1898 		/* For (*,G) entry, don't forward to the incoming interface */
1899 		if ((cache->mfc_origin != htonl(INADDR_ANY) ||
1900 		     ct != true_vifi) &&
1901 		    ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1902 			if (psend != -1) {
1903 				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1904 
1905 				if (skb2)
1906 					ipmr_queue_xmit(net, mrt, skb2, cache,
1907 							psend);
1908 			}
1909 			psend = ct;
1910 		}
1911 	}
1912 last_forward:
1913 	if (psend != -1) {
1914 		if (local) {
1915 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1916 
1917 			if (skb2)
1918 				ipmr_queue_xmit(net, mrt, skb2, cache, psend);
1919 		} else {
1920 			ipmr_queue_xmit(net, mrt, skb, cache, psend);
1921 			return;
1922 		}
1923 	}
1924 
1925 dont_forward:
1926 	if (!local)
1927 		kfree_skb(skb);
1928 }
1929 
1930 static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
1931 {
1932 	struct rtable *rt = skb_rtable(skb);
1933 	struct iphdr *iph = ip_hdr(skb);
1934 	struct flowi4 fl4 = {
1935 		.daddr = iph->daddr,
1936 		.saddr = iph->saddr,
1937 		.flowi4_tos = RT_TOS(iph->tos),
1938 		.flowi4_oif = (rt_is_output_route(rt) ?
1939 			       skb->dev->ifindex : 0),
1940 		.flowi4_iif = (rt_is_output_route(rt) ?
1941 			       LOOPBACK_IFINDEX :
1942 			       skb->dev->ifindex),
1943 		.flowi4_mark = skb->mark,
1944 	};
1945 	struct mr_table *mrt;
1946 	int err;
1947 
1948 	err = ipmr_fib_lookup(net, &fl4, &mrt);
1949 	if (err)
1950 		return ERR_PTR(err);
1951 	return mrt;
1952 }
1953 
1954 /*
1955  *	Multicast packets for forwarding arrive here
1956  *	Called with rcu_read_lock();
1957  */
1958 
1959 int ip_mr_input(struct sk_buff *skb)
1960 {
1961 	struct mfc_cache *cache;
1962 	struct net *net = dev_net(skb->dev);
1963 	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
1964 	struct mr_table *mrt;
1965 
1966 	/* Packet is looped back after forward, it should not be
1967 	 * forwarded second time, but still can be delivered locally.
1968 	 */
1969 	if (IPCB(skb)->flags & IPSKB_FORWARDED)
1970 		goto dont_forward;
1971 
1972 	mrt = ipmr_rt_fib_lookup(net, skb);
1973 	if (IS_ERR(mrt)) {
1974 		kfree_skb(skb);
1975 		return PTR_ERR(mrt);
1976 	}
1977 	if (!local) {
1978 		if (IPCB(skb)->opt.router_alert) {
1979 			if (ip_call_ra_chain(skb))
1980 				return 0;
1981 		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
1982 			/* IGMPv1 (and broken IGMPv2 implementations sort of
1983 			 * Cisco IOS <= 11.2(8)) do not put router alert
1984 			 * option to IGMP packets destined to routable
1985 			 * groups. It is very bad, because it means
1986 			 * that we can forward NO IGMP messages.
1987 			 */
1988 			struct sock *mroute_sk;
1989 
1990 			mroute_sk = rcu_dereference(mrt->mroute_sk);
1991 			if (mroute_sk) {
1992 				nf_reset(skb);
1993 				raw_rcv(mroute_sk, skb);
1994 				return 0;
1995 			}
1996 		    }
1997 	}
1998 
1999 	/* already under rcu_read_lock() */
2000 	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
2001 	if (!cache) {
2002 		int vif = ipmr_find_vif(mrt, skb->dev);
2003 
2004 		if (vif >= 0)
2005 			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
2006 						    vif);
2007 	}
2008 
2009 	/*
2010 	 *	No usable cache entry
2011 	 */
2012 	if (!cache) {
2013 		int vif;
2014 
2015 		if (local) {
2016 			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2017 			ip_local_deliver(skb);
2018 			if (!skb2)
2019 				return -ENOBUFS;
2020 			skb = skb2;
2021 		}
2022 
2023 		read_lock(&mrt_lock);
2024 		vif = ipmr_find_vif(mrt, skb->dev);
2025 		if (vif >= 0) {
2026 			int err2 = ipmr_cache_unresolved(mrt, vif, skb);
2027 			read_unlock(&mrt_lock);
2028 
2029 			return err2;
2030 		}
2031 		read_unlock(&mrt_lock);
2032 		kfree_skb(skb);
2033 		return -ENODEV;
2034 	}
2035 
2036 	read_lock(&mrt_lock);
2037 	ip_mr_forward(net, mrt, skb, cache, local);
2038 	read_unlock(&mrt_lock);
2039 
2040 	if (local)
2041 		return ip_local_deliver(skb);
2042 
2043 	return 0;
2044 
2045 dont_forward:
2046 	if (local)
2047 		return ip_local_deliver(skb);
2048 	kfree_skb(skb);
2049 	return 0;
2050 }
2051 
2052 #ifdef CONFIG_IP_PIMSM
2053 /* called with rcu_read_lock() */
2054 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
2055 		     unsigned int pimlen)
2056 {
2057 	struct net_device *reg_dev = NULL;
2058 	struct iphdr *encap;
2059 
2060 	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
2061 	/*
2062 	 * Check that:
2063 	 * a. packet is really sent to a multicast group
2064 	 * b. packet is not a NULL-REGISTER
2065 	 * c. packet is not truncated
2066 	 */
2067 	if (!ipv4_is_multicast(encap->daddr) ||
2068 	    encap->tot_len == 0 ||
2069 	    ntohs(encap->tot_len) + pimlen > skb->len)
2070 		return 1;
2071 
2072 	read_lock(&mrt_lock);
2073 	if (mrt->mroute_reg_vif_num >= 0)
2074 		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
2075 	read_unlock(&mrt_lock);
2076 
2077 	if (!reg_dev)
2078 		return 1;
2079 
2080 	skb->mac_header = skb->network_header;
2081 	skb_pull(skb, (u8 *)encap - skb->data);
2082 	skb_reset_network_header(skb);
2083 	skb->protocol = htons(ETH_P_IP);
2084 	skb->ip_summed = CHECKSUM_NONE;
2085 
2086 	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
2087 
2088 	netif_rx(skb);
2089 
2090 	return NET_RX_SUCCESS;
2091 }
2092 #endif
2093 
2094 #ifdef CONFIG_IP_PIMSM_V1
2095 /*
2096  * Handle IGMP messages of PIMv1
2097  */
2098 
2099 int pim_rcv_v1(struct sk_buff *skb)
2100 {
2101 	struct igmphdr *pim;
2102 	struct net *net = dev_net(skb->dev);
2103 	struct mr_table *mrt;
2104 
2105 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2106 		goto drop;
2107 
2108 	pim = igmp_hdr(skb);
2109 
2110 	mrt = ipmr_rt_fib_lookup(net, skb);
2111 	if (IS_ERR(mrt))
2112 		goto drop;
2113 	if (!mrt->mroute_do_pim ||
2114 	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2115 		goto drop;
2116 
2117 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2118 drop:
2119 		kfree_skb(skb);
2120 	}
2121 	return 0;
2122 }
2123 #endif
2124 
2125 #ifdef CONFIG_IP_PIMSM_V2
2126 static int pim_rcv(struct sk_buff *skb)
2127 {
2128 	struct pimreghdr *pim;
2129 	struct net *net = dev_net(skb->dev);
2130 	struct mr_table *mrt;
2131 
2132 	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2133 		goto drop;
2134 
2135 	pim = (struct pimreghdr *)skb_transport_header(skb);
2136 	if (pim->type != ((PIM_VERSION << 4) | (PIM_REGISTER)) ||
2137 	    (pim->flags & PIM_NULL_REGISTER) ||
2138 	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2139 	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2140 		goto drop;
2141 
2142 	mrt = ipmr_rt_fib_lookup(net, skb);
2143 	if (IS_ERR(mrt))
2144 		goto drop;
2145 	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2146 drop:
2147 		kfree_skb(skb);
2148 	}
2149 	return 0;
2150 }
2151 #endif
2152 
2153 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2154 			      struct mfc_cache *c, struct rtmsg *rtm)
2155 {
2156 	int ct;
2157 	struct rtnexthop *nhp;
2158 	struct nlattr *mp_attr;
2159 	struct rta_mfc_stats mfcs;
2160 
2161 	/* If cache is unresolved, don't try to parse IIF and OIF */
2162 	if (c->mfc_parent >= MAXVIFS)
2163 		return -ENOENT;
2164 
2165 	if (VIF_EXISTS(mrt, c->mfc_parent) &&
2166 	    nla_put_u32(skb, RTA_IIF, mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
2167 		return -EMSGSIZE;
2168 
2169 	if (!(mp_attr = nla_nest_start(skb, RTA_MULTIPATH)))
2170 		return -EMSGSIZE;
2171 
2172 	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
2173 		if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
2174 			if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp)))) {
2175 				nla_nest_cancel(skb, mp_attr);
2176 				return -EMSGSIZE;
2177 			}
2178 
2179 			nhp->rtnh_flags = 0;
2180 			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
2181 			nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
2182 			nhp->rtnh_len = sizeof(*nhp);
2183 		}
2184 	}
2185 
2186 	nla_nest_end(skb, mp_attr);
2187 
2188 	mfcs.mfcs_packets = c->mfc_un.res.pkt;
2189 	mfcs.mfcs_bytes = c->mfc_un.res.bytes;
2190 	mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
2191 	if (nla_put(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs) < 0)
2192 		return -EMSGSIZE;
2193 
2194 	rtm->rtm_type = RTN_MULTICAST;
2195 	return 1;
2196 }
2197 
2198 int ipmr_get_route(struct net *net, struct sk_buff *skb,
2199 		   __be32 saddr, __be32 daddr,
2200 		   struct rtmsg *rtm, int nowait)
2201 {
2202 	struct mfc_cache *cache;
2203 	struct mr_table *mrt;
2204 	int err;
2205 
2206 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2207 	if (!mrt)
2208 		return -ENOENT;
2209 
2210 	rcu_read_lock();
2211 	cache = ipmr_cache_find(mrt, saddr, daddr);
2212 	if (!cache && skb->dev) {
2213 		int vif = ipmr_find_vif(mrt, skb->dev);
2214 
2215 		if (vif >= 0)
2216 			cache = ipmr_cache_find_any(mrt, daddr, vif);
2217 	}
2218 	if (!cache) {
2219 		struct sk_buff *skb2;
2220 		struct iphdr *iph;
2221 		struct net_device *dev;
2222 		int vif = -1;
2223 
2224 		if (nowait) {
2225 			rcu_read_unlock();
2226 			return -EAGAIN;
2227 		}
2228 
2229 		dev = skb->dev;
2230 		read_lock(&mrt_lock);
2231 		if (dev)
2232 			vif = ipmr_find_vif(mrt, dev);
2233 		if (vif < 0) {
2234 			read_unlock(&mrt_lock);
2235 			rcu_read_unlock();
2236 			return -ENODEV;
2237 		}
2238 		skb2 = skb_clone(skb, GFP_ATOMIC);
2239 		if (!skb2) {
2240 			read_unlock(&mrt_lock);
2241 			rcu_read_unlock();
2242 			return -ENOMEM;
2243 		}
2244 
2245 		skb_push(skb2, sizeof(struct iphdr));
2246 		skb_reset_network_header(skb2);
2247 		iph = ip_hdr(skb2);
2248 		iph->ihl = sizeof(struct iphdr) >> 2;
2249 		iph->saddr = saddr;
2250 		iph->daddr = daddr;
2251 		iph->version = 0;
2252 		err = ipmr_cache_unresolved(mrt, vif, skb2);
2253 		read_unlock(&mrt_lock);
2254 		rcu_read_unlock();
2255 		return err;
2256 	}
2257 
2258 	read_lock(&mrt_lock);
2259 	if (!nowait && (rtm->rtm_flags & RTM_F_NOTIFY))
2260 		cache->mfc_flags |= MFC_NOTIFY;
2261 	err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2262 	read_unlock(&mrt_lock);
2263 	rcu_read_unlock();
2264 	return err;
2265 }
2266 
2267 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2268 			    u32 portid, u32 seq, struct mfc_cache *c, int cmd,
2269 			    int flags)
2270 {
2271 	struct nlmsghdr *nlh;
2272 	struct rtmsg *rtm;
2273 	int err;
2274 
2275 	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2276 	if (!nlh)
2277 		return -EMSGSIZE;
2278 
2279 	rtm = nlmsg_data(nlh);
2280 	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2281 	rtm->rtm_dst_len  = 32;
2282 	rtm->rtm_src_len  = 32;
2283 	rtm->rtm_tos      = 0;
2284 	rtm->rtm_table    = mrt->id;
2285 	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2286 		goto nla_put_failure;
2287 	rtm->rtm_type     = RTN_MULTICAST;
2288 	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2289 	if (c->mfc_flags & MFC_STATIC)
2290 		rtm->rtm_protocol = RTPROT_STATIC;
2291 	else
2292 		rtm->rtm_protocol = RTPROT_MROUTED;
2293 	rtm->rtm_flags    = 0;
2294 
2295 	if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
2296 	    nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
2297 		goto nla_put_failure;
2298 	err = __ipmr_fill_mroute(mrt, skb, c, rtm);
2299 	/* do not break the dump if cache is unresolved */
2300 	if (err < 0 && err != -ENOENT)
2301 		goto nla_put_failure;
2302 
2303 	nlmsg_end(skb, nlh);
2304 	return 0;
2305 
2306 nla_put_failure:
2307 	nlmsg_cancel(skb, nlh);
2308 	return -EMSGSIZE;
2309 }
2310 
2311 static size_t mroute_msgsize(bool unresolved, int maxvif)
2312 {
2313 	size_t len =
2314 		NLMSG_ALIGN(sizeof(struct rtmsg))
2315 		+ nla_total_size(4)	/* RTA_TABLE */
2316 		+ nla_total_size(4)	/* RTA_SRC */
2317 		+ nla_total_size(4)	/* RTA_DST */
2318 		;
2319 
2320 	if (!unresolved)
2321 		len = len
2322 		      + nla_total_size(4)	/* RTA_IIF */
2323 		      + nla_total_size(0)	/* RTA_MULTIPATH */
2324 		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2325 						/* RTA_MFC_STATS */
2326 		      + nla_total_size(sizeof(struct rta_mfc_stats))
2327 		;
2328 
2329 	return len;
2330 }
2331 
2332 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2333 				 int cmd)
2334 {
2335 	struct net *net = read_pnet(&mrt->net);
2336 	struct sk_buff *skb;
2337 	int err = -ENOBUFS;
2338 
2339 	skb = nlmsg_new(mroute_msgsize(mfc->mfc_parent >= MAXVIFS, mrt->maxvif),
2340 			GFP_ATOMIC);
2341 	if (!skb)
2342 		goto errout;
2343 
2344 	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2345 	if (err < 0)
2346 		goto errout;
2347 
2348 	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2349 	return;
2350 
2351 errout:
2352 	kfree_skb(skb);
2353 	if (err < 0)
2354 		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2355 }
2356 
2357 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2358 {
2359 	struct net *net = sock_net(skb->sk);
2360 	struct mr_table *mrt;
2361 	struct mfc_cache *mfc;
2362 	unsigned int t = 0, s_t;
2363 	unsigned int h = 0, s_h;
2364 	unsigned int e = 0, s_e;
2365 
2366 	s_t = cb->args[0];
2367 	s_h = cb->args[1];
2368 	s_e = cb->args[2];
2369 
2370 	rcu_read_lock();
2371 	ipmr_for_each_table(mrt, net) {
2372 		if (t < s_t)
2373 			goto next_table;
2374 		if (t > s_t)
2375 			s_h = 0;
2376 		for (h = s_h; h < MFC_LINES; h++) {
2377 			list_for_each_entry_rcu(mfc, &mrt->mfc_cache_array[h], list) {
2378 				if (e < s_e)
2379 					goto next_entry;
2380 				if (ipmr_fill_mroute(mrt, skb,
2381 						     NETLINK_CB(cb->skb).portid,
2382 						     cb->nlh->nlmsg_seq,
2383 						     mfc, RTM_NEWROUTE,
2384 						     NLM_F_MULTI) < 0)
2385 					goto done;
2386 next_entry:
2387 				e++;
2388 			}
2389 			e = s_e = 0;
2390 		}
2391 		spin_lock_bh(&mfc_unres_lock);
2392 		list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
2393 			if (e < s_e)
2394 				goto next_entry2;
2395 			if (ipmr_fill_mroute(mrt, skb,
2396 					     NETLINK_CB(cb->skb).portid,
2397 					     cb->nlh->nlmsg_seq,
2398 					     mfc, RTM_NEWROUTE,
2399 					     NLM_F_MULTI) < 0) {
2400 				spin_unlock_bh(&mfc_unres_lock);
2401 				goto done;
2402 			}
2403 next_entry2:
2404 			e++;
2405 		}
2406 		spin_unlock_bh(&mfc_unres_lock);
2407 		e = s_e = 0;
2408 		s_h = 0;
2409 next_table:
2410 		t++;
2411 	}
2412 done:
2413 	rcu_read_unlock();
2414 
2415 	cb->args[2] = e;
2416 	cb->args[1] = h;
2417 	cb->args[0] = t;
2418 
2419 	return skb->len;
2420 }
2421 
2422 #ifdef CONFIG_PROC_FS
2423 /*
2424  *	The /proc interfaces to multicast routing :
2425  *	/proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2426  */
2427 struct ipmr_vif_iter {
2428 	struct seq_net_private p;
2429 	struct mr_table *mrt;
2430 	int ct;
2431 };
2432 
2433 static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2434 					   struct ipmr_vif_iter *iter,
2435 					   loff_t pos)
2436 {
2437 	struct mr_table *mrt = iter->mrt;
2438 
2439 	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2440 		if (!VIF_EXISTS(mrt, iter->ct))
2441 			continue;
2442 		if (pos-- == 0)
2443 			return &mrt->vif_table[iter->ct];
2444 	}
2445 	return NULL;
2446 }
2447 
2448 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2449 	__acquires(mrt_lock)
2450 {
2451 	struct ipmr_vif_iter *iter = seq->private;
2452 	struct net *net = seq_file_net(seq);
2453 	struct mr_table *mrt;
2454 
2455 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2456 	if (!mrt)
2457 		return ERR_PTR(-ENOENT);
2458 
2459 	iter->mrt = mrt;
2460 
2461 	read_lock(&mrt_lock);
2462 	return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2463 		: SEQ_START_TOKEN;
2464 }
2465 
2466 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2467 {
2468 	struct ipmr_vif_iter *iter = seq->private;
2469 	struct net *net = seq_file_net(seq);
2470 	struct mr_table *mrt = iter->mrt;
2471 
2472 	++*pos;
2473 	if (v == SEQ_START_TOKEN)
2474 		return ipmr_vif_seq_idx(net, iter, 0);
2475 
2476 	while (++iter->ct < mrt->maxvif) {
2477 		if (!VIF_EXISTS(mrt, iter->ct))
2478 			continue;
2479 		return &mrt->vif_table[iter->ct];
2480 	}
2481 	return NULL;
2482 }
2483 
2484 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2485 	__releases(mrt_lock)
2486 {
2487 	read_unlock(&mrt_lock);
2488 }
2489 
2490 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2491 {
2492 	struct ipmr_vif_iter *iter = seq->private;
2493 	struct mr_table *mrt = iter->mrt;
2494 
2495 	if (v == SEQ_START_TOKEN) {
2496 		seq_puts(seq,
2497 			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2498 	} else {
2499 		const struct vif_device *vif = v;
2500 		const char *name =  vif->dev ? vif->dev->name : "none";
2501 
2502 		seq_printf(seq,
2503 			   "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2504 			   vif - mrt->vif_table,
2505 			   name, vif->bytes_in, vif->pkt_in,
2506 			   vif->bytes_out, vif->pkt_out,
2507 			   vif->flags, vif->local, vif->remote);
2508 	}
2509 	return 0;
2510 }
2511 
2512 static const struct seq_operations ipmr_vif_seq_ops = {
2513 	.start = ipmr_vif_seq_start,
2514 	.next  = ipmr_vif_seq_next,
2515 	.stop  = ipmr_vif_seq_stop,
2516 	.show  = ipmr_vif_seq_show,
2517 };
2518 
2519 static int ipmr_vif_open(struct inode *inode, struct file *file)
2520 {
2521 	return seq_open_net(inode, file, &ipmr_vif_seq_ops,
2522 			    sizeof(struct ipmr_vif_iter));
2523 }
2524 
2525 static const struct file_operations ipmr_vif_fops = {
2526 	.owner	 = THIS_MODULE,
2527 	.open    = ipmr_vif_open,
2528 	.read    = seq_read,
2529 	.llseek  = seq_lseek,
2530 	.release = seq_release_net,
2531 };
2532 
2533 struct ipmr_mfc_iter {
2534 	struct seq_net_private p;
2535 	struct mr_table *mrt;
2536 	struct list_head *cache;
2537 	int ct;
2538 };
2539 
2540 
2541 static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
2542 					  struct ipmr_mfc_iter *it, loff_t pos)
2543 {
2544 	struct mr_table *mrt = it->mrt;
2545 	struct mfc_cache *mfc;
2546 
2547 	rcu_read_lock();
2548 	for (it->ct = 0; it->ct < MFC_LINES; it->ct++) {
2549 		it->cache = &mrt->mfc_cache_array[it->ct];
2550 		list_for_each_entry_rcu(mfc, it->cache, list)
2551 			if (pos-- == 0)
2552 				return mfc;
2553 	}
2554 	rcu_read_unlock();
2555 
2556 	spin_lock_bh(&mfc_unres_lock);
2557 	it->cache = &mrt->mfc_unres_queue;
2558 	list_for_each_entry(mfc, it->cache, list)
2559 		if (pos-- == 0)
2560 			return mfc;
2561 	spin_unlock_bh(&mfc_unres_lock);
2562 
2563 	it->cache = NULL;
2564 	return NULL;
2565 }
2566 
2567 
2568 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2569 {
2570 	struct ipmr_mfc_iter *it = seq->private;
2571 	struct net *net = seq_file_net(seq);
2572 	struct mr_table *mrt;
2573 
2574 	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2575 	if (!mrt)
2576 		return ERR_PTR(-ENOENT);
2577 
2578 	it->mrt = mrt;
2579 	it->cache = NULL;
2580 	it->ct = 0;
2581 	return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
2582 		: SEQ_START_TOKEN;
2583 }
2584 
2585 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2586 {
2587 	struct mfc_cache *mfc = v;
2588 	struct ipmr_mfc_iter *it = seq->private;
2589 	struct net *net = seq_file_net(seq);
2590 	struct mr_table *mrt = it->mrt;
2591 
2592 	++*pos;
2593 
2594 	if (v == SEQ_START_TOKEN)
2595 		return ipmr_mfc_seq_idx(net, seq->private, 0);
2596 
2597 	if (mfc->list.next != it->cache)
2598 		return list_entry(mfc->list.next, struct mfc_cache, list);
2599 
2600 	if (it->cache == &mrt->mfc_unres_queue)
2601 		goto end_of_list;
2602 
2603 	BUG_ON(it->cache != &mrt->mfc_cache_array[it->ct]);
2604 
2605 	while (++it->ct < MFC_LINES) {
2606 		it->cache = &mrt->mfc_cache_array[it->ct];
2607 		if (list_empty(it->cache))
2608 			continue;
2609 		return list_first_entry(it->cache, struct mfc_cache, list);
2610 	}
2611 
2612 	/* exhausted cache_array, show unresolved */
2613 	rcu_read_unlock();
2614 	it->cache = &mrt->mfc_unres_queue;
2615 	it->ct = 0;
2616 
2617 	spin_lock_bh(&mfc_unres_lock);
2618 	if (!list_empty(it->cache))
2619 		return list_first_entry(it->cache, struct mfc_cache, list);
2620 
2621 end_of_list:
2622 	spin_unlock_bh(&mfc_unres_lock);
2623 	it->cache = NULL;
2624 
2625 	return NULL;
2626 }
2627 
2628 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
2629 {
2630 	struct ipmr_mfc_iter *it = seq->private;
2631 	struct mr_table *mrt = it->mrt;
2632 
2633 	if (it->cache == &mrt->mfc_unres_queue)
2634 		spin_unlock_bh(&mfc_unres_lock);
2635 	else if (it->cache == &mrt->mfc_cache_array[it->ct])
2636 		rcu_read_unlock();
2637 }
2638 
2639 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2640 {
2641 	int n;
2642 
2643 	if (v == SEQ_START_TOKEN) {
2644 		seq_puts(seq,
2645 		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2646 	} else {
2647 		const struct mfc_cache *mfc = v;
2648 		const struct ipmr_mfc_iter *it = seq->private;
2649 		const struct mr_table *mrt = it->mrt;
2650 
2651 		seq_printf(seq, "%08X %08X %-3hd",
2652 			   (__force u32) mfc->mfc_mcastgrp,
2653 			   (__force u32) mfc->mfc_origin,
2654 			   mfc->mfc_parent);
2655 
2656 		if (it->cache != &mrt->mfc_unres_queue) {
2657 			seq_printf(seq, " %8lu %8lu %8lu",
2658 				   mfc->mfc_un.res.pkt,
2659 				   mfc->mfc_un.res.bytes,
2660 				   mfc->mfc_un.res.wrong_if);
2661 			for (n = mfc->mfc_un.res.minvif;
2662 			     n < mfc->mfc_un.res.maxvif; n++) {
2663 				if (VIF_EXISTS(mrt, n) &&
2664 				    mfc->mfc_un.res.ttls[n] < 255)
2665 					seq_printf(seq,
2666 					   " %2d:%-3d",
2667 					   n, mfc->mfc_un.res.ttls[n]);
2668 			}
2669 		} else {
2670 			/* unresolved mfc_caches don't contain
2671 			 * pkt, bytes and wrong_if values
2672 			 */
2673 			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
2674 		}
2675 		seq_putc(seq, '\n');
2676 	}
2677 	return 0;
2678 }
2679 
2680 static const struct seq_operations ipmr_mfc_seq_ops = {
2681 	.start = ipmr_mfc_seq_start,
2682 	.next  = ipmr_mfc_seq_next,
2683 	.stop  = ipmr_mfc_seq_stop,
2684 	.show  = ipmr_mfc_seq_show,
2685 };
2686 
2687 static int ipmr_mfc_open(struct inode *inode, struct file *file)
2688 {
2689 	return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
2690 			    sizeof(struct ipmr_mfc_iter));
2691 }
2692 
2693 static const struct file_operations ipmr_mfc_fops = {
2694 	.owner	 = THIS_MODULE,
2695 	.open    = ipmr_mfc_open,
2696 	.read    = seq_read,
2697 	.llseek  = seq_lseek,
2698 	.release = seq_release_net,
2699 };
2700 #endif
2701 
2702 #ifdef CONFIG_IP_PIMSM_V2
2703 static const struct net_protocol pim_protocol = {
2704 	.handler	=	pim_rcv,
2705 	.netns_ok	=	1,
2706 };
2707 #endif
2708 
2709 
2710 /*
2711  *	Setup for IP multicast routing
2712  */
2713 static int __net_init ipmr_net_init(struct net *net)
2714 {
2715 	int err;
2716 
2717 	err = ipmr_rules_init(net);
2718 	if (err < 0)
2719 		goto fail;
2720 
2721 #ifdef CONFIG_PROC_FS
2722 	err = -ENOMEM;
2723 	if (!proc_create("ip_mr_vif", 0, net->proc_net, &ipmr_vif_fops))
2724 		goto proc_vif_fail;
2725 	if (!proc_create("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_fops))
2726 		goto proc_cache_fail;
2727 #endif
2728 	return 0;
2729 
2730 #ifdef CONFIG_PROC_FS
2731 proc_cache_fail:
2732 	remove_proc_entry("ip_mr_vif", net->proc_net);
2733 proc_vif_fail:
2734 	ipmr_rules_exit(net);
2735 #endif
2736 fail:
2737 	return err;
2738 }
2739 
2740 static void __net_exit ipmr_net_exit(struct net *net)
2741 {
2742 #ifdef CONFIG_PROC_FS
2743 	remove_proc_entry("ip_mr_cache", net->proc_net);
2744 	remove_proc_entry("ip_mr_vif", net->proc_net);
2745 #endif
2746 	ipmr_rules_exit(net);
2747 }
2748 
2749 static struct pernet_operations ipmr_net_ops = {
2750 	.init = ipmr_net_init,
2751 	.exit = ipmr_net_exit,
2752 };
2753 
2754 int __init ip_mr_init(void)
2755 {
2756 	int err;
2757 
2758 	mrt_cachep = kmem_cache_create("ip_mrt_cache",
2759 				       sizeof(struct mfc_cache),
2760 				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
2761 				       NULL);
2762 	if (!mrt_cachep)
2763 		return -ENOMEM;
2764 
2765 	err = register_pernet_subsys(&ipmr_net_ops);
2766 	if (err)
2767 		goto reg_pernet_fail;
2768 
2769 	err = register_netdevice_notifier(&ip_mr_notifier);
2770 	if (err)
2771 		goto reg_notif_fail;
2772 #ifdef CONFIG_IP_PIMSM_V2
2773 	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
2774 		pr_err("%s: can't add PIM protocol\n", __func__);
2775 		err = -EAGAIN;
2776 		goto add_proto_fail;
2777 	}
2778 #endif
2779 	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
2780 		      NULL, ipmr_rtm_dumproute, NULL);
2781 	return 0;
2782 
2783 #ifdef CONFIG_IP_PIMSM_V2
2784 add_proto_fail:
2785 	unregister_netdevice_notifier(&ip_mr_notifier);
2786 #endif
2787 reg_notif_fail:
2788 	unregister_pernet_subsys(&ipmr_net_ops);
2789 reg_pernet_fail:
2790 	kmem_cache_destroy(mrt_cachep);
2791 	return err;
2792 }
2793