xref: /kernel/linux/linux-5.10/net/ipv4/ipmr.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *	IP multicast routing support for mrouted 3.6/3.8
4 *
5 *		(c) 1995 Alan Cox, <alan@lxorguk.ukuu.org.uk>
6 *	  Linux Consultancy and Custom Driver Development
7 *
8 *	Fixes:
9 *	Michael Chastain	:	Incorrect size of copying.
10 *	Alan Cox		:	Added the cache manager code
11 *	Alan Cox		:	Fixed the clone/copy bug and device race.
12 *	Mike McLagan		:	Routing by source
13 *	Malcolm Beattie		:	Buffer handling fixes.
14 *	Alexey Kuznetsov	:	Double buffer free and other fixes.
15 *	SVR Anand		:	Fixed several multicast bugs and problems.
16 *	Alexey Kuznetsov	:	Status, optimisations and more.
17 *	Brad Parker		:	Better behaviour on mrouted upcall
18 *					overflow.
19 *      Carlos Picoto           :       PIMv1 Support
20 *	Pavlin Ivanov Radoslavov:	PIMv2 Registers must checksum only PIM header
21 *					Relax this requirement to work with older peers.
22 */
23
24#include <linux/uaccess.h>
25#include <linux/types.h>
26#include <linux/cache.h>
27#include <linux/capability.h>
28#include <linux/errno.h>
29#include <linux/mm.h>
30#include <linux/kernel.h>
31#include <linux/fcntl.h>
32#include <linux/stat.h>
33#include <linux/socket.h>
34#include <linux/in.h>
35#include <linux/inet.h>
36#include <linux/netdevice.h>
37#include <linux/inetdevice.h>
38#include <linux/igmp.h>
39#include <linux/proc_fs.h>
40#include <linux/seq_file.h>
41#include <linux/mroute.h>
42#include <linux/init.h>
43#include <linux/if_ether.h>
44#include <linux/slab.h>
45#include <net/net_namespace.h>
46#include <net/ip.h>
47#include <net/protocol.h>
48#include <linux/skbuff.h>
49#include <net/route.h>
50#include <net/icmp.h>
51#include <net/udp.h>
52#include <net/raw.h>
53#include <linux/notifier.h>
54#include <linux/if_arp.h>
55#include <linux/netfilter_ipv4.h>
56#include <linux/compat.h>
57#include <linux/export.h>
58#include <linux/rhashtable.h>
59#include <net/ip_tunnels.h>
60#include <net/checksum.h>
61#include <net/netlink.h>
62#include <net/fib_rules.h>
63#include <linux/netconf.h>
64#include <net/rtnh.h>
65
66#include <linux/nospec.h>
67
68struct ipmr_rule {
69	struct fib_rule		common;
70};
71
72struct ipmr_result {
73	struct mr_table		*mrt;
74};
75
76/* Big lock, protecting vif table, mrt cache and mroute socket state.
77 * Note that the changes are semaphored via rtnl_lock.
78 */
79
80static DEFINE_RWLOCK(mrt_lock);
81
82/* Multicast router control variables */
83
84/* Special spinlock for queue of unresolved entries */
85static DEFINE_SPINLOCK(mfc_unres_lock);
86
87/* We return to original Alan's scheme. Hash table of resolved
88 * entries is changed only in process context and protected
89 * with weak lock mrt_lock. Queue of unresolved entries is protected
90 * with strong spinlock mfc_unres_lock.
91 *
92 * In this case data path is free of exclusive locks at all.
93 */
94
95static struct kmem_cache *mrt_cachep __ro_after_init;
96
97static struct mr_table *ipmr_new_table(struct net *net, u32 id);
98static void ipmr_free_table(struct mr_table *mrt);
99
100static void ip_mr_forward(struct net *net, struct mr_table *mrt,
101			  struct net_device *dev, struct sk_buff *skb,
102			  struct mfc_cache *cache, int local);
103static int ipmr_cache_report(struct mr_table *mrt,
104			     struct sk_buff *pkt, vifi_t vifi, int assert);
105static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
106				 int cmd);
107static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
108static void mroute_clean_tables(struct mr_table *mrt, int flags);
109static void ipmr_expire_process(struct timer_list *t);
110
111#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
112#define ipmr_for_each_table(mrt, net)					\
113	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list,	\
114				lockdep_rtnl_is_held() ||		\
115				list_empty(&net->ipv4.mr_tables))
116
117static struct mr_table *ipmr_mr_table_iter(struct net *net,
118					   struct mr_table *mrt)
119{
120	struct mr_table *ret;
121
122	if (!mrt)
123		ret = list_entry_rcu(net->ipv4.mr_tables.next,
124				     struct mr_table, list);
125	else
126		ret = list_entry_rcu(mrt->list.next,
127				     struct mr_table, list);
128
129	if (&ret->list == &net->ipv4.mr_tables)
130		return NULL;
131	return ret;
132}
133
134static struct mr_table *ipmr_get_table(struct net *net, u32 id)
135{
136	struct mr_table *mrt;
137
138	ipmr_for_each_table(mrt, net) {
139		if (mrt->id == id)
140			return mrt;
141	}
142	return NULL;
143}
144
145static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
146			   struct mr_table **mrt)
147{
148	int err;
149	struct ipmr_result res;
150	struct fib_lookup_arg arg = {
151		.result = &res,
152		.flags = FIB_LOOKUP_NOREF,
153	};
154
155	/* update flow if oif or iif point to device enslaved to l3mdev */
156	l3mdev_update_flow(net, flowi4_to_flowi(flp4));
157
158	err = fib_rules_lookup(net->ipv4.mr_rules_ops,
159			       flowi4_to_flowi(flp4), 0, &arg);
160	if (err < 0)
161		return err;
162	*mrt = res.mrt;
163	return 0;
164}
165
166static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
167			    int flags, struct fib_lookup_arg *arg)
168{
169	struct ipmr_result *res = arg->result;
170	struct mr_table *mrt;
171
172	switch (rule->action) {
173	case FR_ACT_TO_TBL:
174		break;
175	case FR_ACT_UNREACHABLE:
176		return -ENETUNREACH;
177	case FR_ACT_PROHIBIT:
178		return -EACCES;
179	case FR_ACT_BLACKHOLE:
180	default:
181		return -EINVAL;
182	}
183
184	arg->table = fib_rule_get_table(rule, arg);
185
186	mrt = ipmr_get_table(rule->fr_net, arg->table);
187	if (!mrt)
188		return -EAGAIN;
189	res->mrt = mrt;
190	return 0;
191}
192
193static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
194{
195	return 1;
196}
197
198static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
199	FRA_GENERIC_POLICY,
200};
201
202static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
203			       struct fib_rule_hdr *frh, struct nlattr **tb,
204			       struct netlink_ext_ack *extack)
205{
206	return 0;
207}
208
209static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
210			     struct nlattr **tb)
211{
212	return 1;
213}
214
215static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
216			  struct fib_rule_hdr *frh)
217{
218	frh->dst_len = 0;
219	frh->src_len = 0;
220	frh->tos     = 0;
221	return 0;
222}
223
224static const struct fib_rules_ops __net_initconst ipmr_rules_ops_template = {
225	.family		= RTNL_FAMILY_IPMR,
226	.rule_size	= sizeof(struct ipmr_rule),
227	.addr_size	= sizeof(u32),
228	.action		= ipmr_rule_action,
229	.match		= ipmr_rule_match,
230	.configure	= ipmr_rule_configure,
231	.compare	= ipmr_rule_compare,
232	.fill		= ipmr_rule_fill,
233	.nlgroup	= RTNLGRP_IPV4_RULE,
234	.policy		= ipmr_rule_policy,
235	.owner		= THIS_MODULE,
236};
237
238static int __net_init ipmr_rules_init(struct net *net)
239{
240	struct fib_rules_ops *ops;
241	struct mr_table *mrt;
242	int err;
243
244	ops = fib_rules_register(&ipmr_rules_ops_template, net);
245	if (IS_ERR(ops))
246		return PTR_ERR(ops);
247
248	INIT_LIST_HEAD(&net->ipv4.mr_tables);
249
250	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
251	if (IS_ERR(mrt)) {
252		err = PTR_ERR(mrt);
253		goto err1;
254	}
255
256	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
257	if (err < 0)
258		goto err2;
259
260	net->ipv4.mr_rules_ops = ops;
261	return 0;
262
263err2:
264	rtnl_lock();
265	ipmr_free_table(mrt);
266	rtnl_unlock();
267err1:
268	fib_rules_unregister(ops);
269	return err;
270}
271
272static void __net_exit ipmr_rules_exit(struct net *net)
273{
274	struct mr_table *mrt, *next;
275
276	rtnl_lock();
277	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
278		list_del(&mrt->list);
279		ipmr_free_table(mrt);
280	}
281	fib_rules_unregister(net->ipv4.mr_rules_ops);
282	rtnl_unlock();
283}
284
285static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
286			   struct netlink_ext_ack *extack)
287{
288	return fib_rules_dump(net, nb, RTNL_FAMILY_IPMR, extack);
289}
290
291static unsigned int ipmr_rules_seq_read(struct net *net)
292{
293	return fib_rules_seq_read(net, RTNL_FAMILY_IPMR);
294}
295
296bool ipmr_rule_default(const struct fib_rule *rule)
297{
298	return fib_rule_matchall(rule) && rule->table == RT_TABLE_DEFAULT;
299}
300EXPORT_SYMBOL(ipmr_rule_default);
301#else
302#define ipmr_for_each_table(mrt, net) \
303	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
304
305static struct mr_table *ipmr_mr_table_iter(struct net *net,
306					   struct mr_table *mrt)
307{
308	if (!mrt)
309		return net->ipv4.mrt;
310	return NULL;
311}
312
313static struct mr_table *ipmr_get_table(struct net *net, u32 id)
314{
315	return net->ipv4.mrt;
316}
317
318static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
319			   struct mr_table **mrt)
320{
321	*mrt = net->ipv4.mrt;
322	return 0;
323}
324
325static int __net_init ipmr_rules_init(struct net *net)
326{
327	struct mr_table *mrt;
328
329	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
330	if (IS_ERR(mrt))
331		return PTR_ERR(mrt);
332	net->ipv4.mrt = mrt;
333	return 0;
334}
335
336static void __net_exit ipmr_rules_exit(struct net *net)
337{
338	rtnl_lock();
339	ipmr_free_table(net->ipv4.mrt);
340	net->ipv4.mrt = NULL;
341	rtnl_unlock();
342}
343
344static int ipmr_rules_dump(struct net *net, struct notifier_block *nb,
345			   struct netlink_ext_ack *extack)
346{
347	return 0;
348}
349
350static unsigned int ipmr_rules_seq_read(struct net *net)
351{
352	return 0;
353}
354
355bool ipmr_rule_default(const struct fib_rule *rule)
356{
357	return true;
358}
359EXPORT_SYMBOL(ipmr_rule_default);
360#endif
361
362static inline int ipmr_hash_cmp(struct rhashtable_compare_arg *arg,
363				const void *ptr)
364{
365	const struct mfc_cache_cmp_arg *cmparg = arg->key;
366	struct mfc_cache *c = (struct mfc_cache *)ptr;
367
368	return cmparg->mfc_mcastgrp != c->mfc_mcastgrp ||
369	       cmparg->mfc_origin != c->mfc_origin;
370}
371
372static const struct rhashtable_params ipmr_rht_params = {
373	.head_offset = offsetof(struct mr_mfc, mnode),
374	.key_offset = offsetof(struct mfc_cache, cmparg),
375	.key_len = sizeof(struct mfc_cache_cmp_arg),
376	.nelem_hint = 3,
377	.obj_cmpfn = ipmr_hash_cmp,
378	.automatic_shrinking = true,
379};
380
381static void ipmr_new_table_set(struct mr_table *mrt,
382			       struct net *net)
383{
384#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
385	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
386#endif
387}
388
389static struct mfc_cache_cmp_arg ipmr_mr_table_ops_cmparg_any = {
390	.mfc_mcastgrp = htonl(INADDR_ANY),
391	.mfc_origin = htonl(INADDR_ANY),
392};
393
394static struct mr_table_ops ipmr_mr_table_ops = {
395	.rht_params = &ipmr_rht_params,
396	.cmparg_any = &ipmr_mr_table_ops_cmparg_any,
397};
398
399static struct mr_table *ipmr_new_table(struct net *net, u32 id)
400{
401	struct mr_table *mrt;
402
403	/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
404	if (id != RT_TABLE_DEFAULT && id >= 1000000000)
405		return ERR_PTR(-EINVAL);
406
407	mrt = ipmr_get_table(net, id);
408	if (mrt)
409		return mrt;
410
411	return mr_table_alloc(net, id, &ipmr_mr_table_ops,
412			      ipmr_expire_process, ipmr_new_table_set);
413}
414
415static void ipmr_free_table(struct mr_table *mrt)
416{
417	del_timer_sync(&mrt->ipmr_expire_timer);
418	mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC |
419				 MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC);
420	rhltable_destroy(&mrt->mfc_hash);
421	kfree(mrt);
422}
423
424/* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
425
426/* Initialize ipmr pimreg/tunnel in_device */
427static bool ipmr_init_vif_indev(const struct net_device *dev)
428{
429	struct in_device *in_dev;
430
431	ASSERT_RTNL();
432
433	in_dev = __in_dev_get_rtnl(dev);
434	if (!in_dev)
435		return false;
436	ipv4_devconf_setall(in_dev);
437	neigh_parms_data_state_setall(in_dev->arp_parms);
438	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
439
440	return true;
441}
442
443static struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
444{
445	struct net_device *tunnel_dev, *new_dev;
446	struct ip_tunnel_parm p = { };
447	int err;
448
449	tunnel_dev = __dev_get_by_name(net, "tunl0");
450	if (!tunnel_dev)
451		goto out;
452
453	p.iph.daddr = v->vifc_rmt_addr.s_addr;
454	p.iph.saddr = v->vifc_lcl_addr.s_addr;
455	p.iph.version = 4;
456	p.iph.ihl = 5;
457	p.iph.protocol = IPPROTO_IPIP;
458	sprintf(p.name, "dvmrp%d", v->vifc_vifi);
459
460	if (!tunnel_dev->netdev_ops->ndo_tunnel_ctl)
461		goto out;
462	err = tunnel_dev->netdev_ops->ndo_tunnel_ctl(tunnel_dev, &p,
463			SIOCADDTUNNEL);
464	if (err)
465		goto out;
466
467	new_dev = __dev_get_by_name(net, p.name);
468	if (!new_dev)
469		goto out;
470
471	new_dev->flags |= IFF_MULTICAST;
472	if (!ipmr_init_vif_indev(new_dev))
473		goto out_unregister;
474	if (dev_open(new_dev, NULL))
475		goto out_unregister;
476	dev_hold(new_dev);
477	err = dev_set_allmulti(new_dev, 1);
478	if (err) {
479		dev_close(new_dev);
480		tunnel_dev->netdev_ops->ndo_tunnel_ctl(tunnel_dev, &p,
481				SIOCDELTUNNEL);
482		dev_put(new_dev);
483		new_dev = ERR_PTR(err);
484	}
485	return new_dev;
486
487out_unregister:
488	unregister_netdevice(new_dev);
489out:
490	return ERR_PTR(-ENOBUFS);
491}
492
493#if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
494static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
495{
496	struct net *net = dev_net(dev);
497	struct mr_table *mrt;
498	struct flowi4 fl4 = {
499		.flowi4_oif	= dev->ifindex,
500		.flowi4_iif	= skb->skb_iif ? : LOOPBACK_IFINDEX,
501		.flowi4_mark	= skb->mark,
502	};
503	int err;
504
505	err = ipmr_fib_lookup(net, &fl4, &mrt);
506	if (err < 0) {
507		kfree_skb(skb);
508		return err;
509	}
510
511	read_lock(&mrt_lock);
512	dev->stats.tx_bytes += skb->len;
513	dev->stats.tx_packets++;
514	ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
515	read_unlock(&mrt_lock);
516	kfree_skb(skb);
517	return NETDEV_TX_OK;
518}
519
520static int reg_vif_get_iflink(const struct net_device *dev)
521{
522	return 0;
523}
524
525static const struct net_device_ops reg_vif_netdev_ops = {
526	.ndo_start_xmit	= reg_vif_xmit,
527	.ndo_get_iflink = reg_vif_get_iflink,
528};
529
530static void reg_vif_setup(struct net_device *dev)
531{
532	dev->type		= ARPHRD_PIMREG;
533	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
534	dev->flags		= IFF_NOARP;
535	dev->netdev_ops		= &reg_vif_netdev_ops;
536	dev->needs_free_netdev	= true;
537	dev->features		|= NETIF_F_NETNS_LOCAL;
538}
539
540static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
541{
542	struct net_device *dev;
543	char name[IFNAMSIZ];
544
545	if (mrt->id == RT_TABLE_DEFAULT)
546		sprintf(name, "pimreg");
547	else
548		sprintf(name, "pimreg%u", mrt->id);
549
550	dev = alloc_netdev(0, name, NET_NAME_UNKNOWN, reg_vif_setup);
551
552	if (!dev)
553		return NULL;
554
555	dev_net_set(dev, net);
556
557	if (register_netdevice(dev)) {
558		free_netdev(dev);
559		return NULL;
560	}
561
562	if (!ipmr_init_vif_indev(dev))
563		goto failure;
564	if (dev_open(dev, NULL))
565		goto failure;
566
567	dev_hold(dev);
568
569	return dev;
570
571failure:
572	unregister_netdevice(dev);
573	return NULL;
574}
575
576/* called with rcu_read_lock() */
577static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
578		     unsigned int pimlen)
579{
580	struct net_device *reg_dev = NULL;
581	struct iphdr *encap;
582
583	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
584	/* Check that:
585	 * a. packet is really sent to a multicast group
586	 * b. packet is not a NULL-REGISTER
587	 * c. packet is not truncated
588	 */
589	if (!ipv4_is_multicast(encap->daddr) ||
590	    encap->tot_len == 0 ||
591	    ntohs(encap->tot_len) + pimlen > skb->len)
592		return 1;
593
594	read_lock(&mrt_lock);
595	if (mrt->mroute_reg_vif_num >= 0)
596		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
597	read_unlock(&mrt_lock);
598
599	if (!reg_dev)
600		return 1;
601
602	skb->mac_header = skb->network_header;
603	skb_pull(skb, (u8 *)encap - skb->data);
604	skb_reset_network_header(skb);
605	skb->protocol = htons(ETH_P_IP);
606	skb->ip_summed = CHECKSUM_NONE;
607
608	skb_tunnel_rx(skb, reg_dev, dev_net(reg_dev));
609
610	netif_rx(skb);
611
612	return NET_RX_SUCCESS;
613}
614#else
615static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
616{
617	return NULL;
618}
619#endif
620
621static int call_ipmr_vif_entry_notifiers(struct net *net,
622					 enum fib_event_type event_type,
623					 struct vif_device *vif,
624					 vifi_t vif_index, u32 tb_id)
625{
626	return mr_call_vif_notifiers(net, RTNL_FAMILY_IPMR, event_type,
627				     vif, vif_index, tb_id,
628				     &net->ipv4.ipmr_seq);
629}
630
631static int call_ipmr_mfc_entry_notifiers(struct net *net,
632					 enum fib_event_type event_type,
633					 struct mfc_cache *mfc, u32 tb_id)
634{
635	return mr_call_mfc_notifiers(net, RTNL_FAMILY_IPMR, event_type,
636				     &mfc->_c, tb_id, &net->ipv4.ipmr_seq);
637}
638
639/**
640 *	vif_delete - Delete a VIF entry
641 *	@mrt: Table to delete from
642 *	@vifi: VIF identifier to delete
643 *	@notify: Set to 1, if the caller is a notifier_call
644 *	@head: if unregistering the VIF, place it on this queue
645 */
646static int vif_delete(struct mr_table *mrt, int vifi, int notify,
647		      struct list_head *head)
648{
649	struct net *net = read_pnet(&mrt->net);
650	struct vif_device *v;
651	struct net_device *dev;
652	struct in_device *in_dev;
653
654	if (vifi < 0 || vifi >= mrt->maxvif)
655		return -EADDRNOTAVAIL;
656
657	v = &mrt->vif_table[vifi];
658
659	if (VIF_EXISTS(mrt, vifi))
660		call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_DEL, v, vifi,
661					      mrt->id);
662
663	write_lock_bh(&mrt_lock);
664	dev = v->dev;
665	v->dev = NULL;
666
667	if (!dev) {
668		write_unlock_bh(&mrt_lock);
669		return -EADDRNOTAVAIL;
670	}
671
672	if (vifi == mrt->mroute_reg_vif_num)
673		mrt->mroute_reg_vif_num = -1;
674
675	if (vifi + 1 == mrt->maxvif) {
676		int tmp;
677
678		for (tmp = vifi - 1; tmp >= 0; tmp--) {
679			if (VIF_EXISTS(mrt, tmp))
680				break;
681		}
682		mrt->maxvif = tmp+1;
683	}
684
685	write_unlock_bh(&mrt_lock);
686
687	dev_set_allmulti(dev, -1);
688
689	in_dev = __in_dev_get_rtnl(dev);
690	if (in_dev) {
691		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
692		inet_netconf_notify_devconf(dev_net(dev), RTM_NEWNETCONF,
693					    NETCONFA_MC_FORWARDING,
694					    dev->ifindex, &in_dev->cnf);
695		ip_rt_multicast_event(in_dev);
696	}
697
698	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
699		unregister_netdevice_queue(dev, head);
700
701	dev_put(dev);
702	return 0;
703}
704
705static void ipmr_cache_free_rcu(struct rcu_head *head)
706{
707	struct mr_mfc *c = container_of(head, struct mr_mfc, rcu);
708
709	kmem_cache_free(mrt_cachep, (struct mfc_cache *)c);
710}
711
712static void ipmr_cache_free(struct mfc_cache *c)
713{
714	call_rcu(&c->_c.rcu, ipmr_cache_free_rcu);
715}
716
717/* Destroy an unresolved cache entry, killing queued skbs
718 * and reporting error to netlink readers.
719 */
720static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
721{
722	struct net *net = read_pnet(&mrt->net);
723	struct sk_buff *skb;
724	struct nlmsgerr *e;
725
726	atomic_dec(&mrt->cache_resolve_queue_len);
727
728	while ((skb = skb_dequeue(&c->_c.mfc_un.unres.unresolved))) {
729		if (ip_hdr(skb)->version == 0) {
730			struct nlmsghdr *nlh = skb_pull(skb,
731							sizeof(struct iphdr));
732			nlh->nlmsg_type = NLMSG_ERROR;
733			nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
734			skb_trim(skb, nlh->nlmsg_len);
735			e = nlmsg_data(nlh);
736			e->error = -ETIMEDOUT;
737			memset(&e->msg, 0, sizeof(e->msg));
738
739			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
740		} else {
741			kfree_skb(skb);
742		}
743	}
744
745	ipmr_cache_free(c);
746}
747
748/* Timer process for the unresolved queue. */
749static void ipmr_expire_process(struct timer_list *t)
750{
751	struct mr_table *mrt = from_timer(mrt, t, ipmr_expire_timer);
752	struct mr_mfc *c, *next;
753	unsigned long expires;
754	unsigned long now;
755
756	if (!spin_trylock(&mfc_unres_lock)) {
757		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
758		return;
759	}
760
761	if (list_empty(&mrt->mfc_unres_queue))
762		goto out;
763
764	now = jiffies;
765	expires = 10*HZ;
766
767	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
768		if (time_after(c->mfc_un.unres.expires, now)) {
769			unsigned long interval = c->mfc_un.unres.expires - now;
770			if (interval < expires)
771				expires = interval;
772			continue;
773		}
774
775		list_del(&c->list);
776		mroute_netlink_event(mrt, (struct mfc_cache *)c, RTM_DELROUTE);
777		ipmr_destroy_unres(mrt, (struct mfc_cache *)c);
778	}
779
780	if (!list_empty(&mrt->mfc_unres_queue))
781		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
782
783out:
784	spin_unlock(&mfc_unres_lock);
785}
786
787/* Fill oifs list. It is called under write locked mrt_lock. */
788static void ipmr_update_thresholds(struct mr_table *mrt, struct mr_mfc *cache,
789				   unsigned char *ttls)
790{
791	int vifi;
792
793	cache->mfc_un.res.minvif = MAXVIFS;
794	cache->mfc_un.res.maxvif = 0;
795	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
796
797	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
798		if (VIF_EXISTS(mrt, vifi) &&
799		    ttls[vifi] && ttls[vifi] < 255) {
800			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
801			if (cache->mfc_un.res.minvif > vifi)
802				cache->mfc_un.res.minvif = vifi;
803			if (cache->mfc_un.res.maxvif <= vifi)
804				cache->mfc_un.res.maxvif = vifi + 1;
805		}
806	}
807	cache->mfc_un.res.lastuse = jiffies;
808}
809
810static int vif_add(struct net *net, struct mr_table *mrt,
811		   struct vifctl *vifc, int mrtsock)
812{
813	struct netdev_phys_item_id ppid = { };
814	int vifi = vifc->vifc_vifi;
815	struct vif_device *v = &mrt->vif_table[vifi];
816	struct net_device *dev;
817	struct in_device *in_dev;
818	int err;
819
820	/* Is vif busy ? */
821	if (VIF_EXISTS(mrt, vifi))
822		return -EADDRINUSE;
823
824	switch (vifc->vifc_flags) {
825	case VIFF_REGISTER:
826		if (!ipmr_pimsm_enabled())
827			return -EINVAL;
828		/* Special Purpose VIF in PIM
829		 * All the packets will be sent to the daemon
830		 */
831		if (mrt->mroute_reg_vif_num >= 0)
832			return -EADDRINUSE;
833		dev = ipmr_reg_vif(net, mrt);
834		if (!dev)
835			return -ENOBUFS;
836		err = dev_set_allmulti(dev, 1);
837		if (err) {
838			unregister_netdevice(dev);
839			dev_put(dev);
840			return err;
841		}
842		break;
843	case VIFF_TUNNEL:
844		dev = ipmr_new_tunnel(net, vifc);
845		if (IS_ERR(dev))
846			return PTR_ERR(dev);
847		break;
848	case VIFF_USE_IFINDEX:
849	case 0:
850		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
851			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
852			if (dev && !__in_dev_get_rtnl(dev)) {
853				dev_put(dev);
854				return -EADDRNOTAVAIL;
855			}
856		} else {
857			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
858		}
859		if (!dev)
860			return -EADDRNOTAVAIL;
861		err = dev_set_allmulti(dev, 1);
862		if (err) {
863			dev_put(dev);
864			return err;
865		}
866		break;
867	default:
868		return -EINVAL;
869	}
870
871	in_dev = __in_dev_get_rtnl(dev);
872	if (!in_dev) {
873		dev_put(dev);
874		return -EADDRNOTAVAIL;
875	}
876	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
877	inet_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_MC_FORWARDING,
878				    dev->ifindex, &in_dev->cnf);
879	ip_rt_multicast_event(in_dev);
880
881	/* Fill in the VIF structures */
882	vif_device_init(v, dev, vifc->vifc_rate_limit,
883			vifc->vifc_threshold,
884			vifc->vifc_flags | (!mrtsock ? VIFF_STATIC : 0),
885			(VIFF_TUNNEL | VIFF_REGISTER));
886
887	err = dev_get_port_parent_id(dev, &ppid, true);
888	if (err == 0) {
889		memcpy(v->dev_parent_id.id, ppid.id, ppid.id_len);
890		v->dev_parent_id.id_len = ppid.id_len;
891	} else {
892		v->dev_parent_id.id_len = 0;
893	}
894
895	v->local = vifc->vifc_lcl_addr.s_addr;
896	v->remote = vifc->vifc_rmt_addr.s_addr;
897
898	/* And finish update writing critical data */
899	write_lock_bh(&mrt_lock);
900	v->dev = dev;
901	if (v->flags & VIFF_REGISTER)
902		mrt->mroute_reg_vif_num = vifi;
903	if (vifi+1 > mrt->maxvif)
904		mrt->maxvif = vifi+1;
905	write_unlock_bh(&mrt_lock);
906	call_ipmr_vif_entry_notifiers(net, FIB_EVENT_VIF_ADD, v, vifi, mrt->id);
907	return 0;
908}
909
910/* called with rcu_read_lock() */
911static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
912					 __be32 origin,
913					 __be32 mcastgrp)
914{
915	struct mfc_cache_cmp_arg arg = {
916			.mfc_mcastgrp = mcastgrp,
917			.mfc_origin = origin
918	};
919
920	return mr_mfc_find(mrt, &arg);
921}
922
923/* Look for a (*,G) entry */
924static struct mfc_cache *ipmr_cache_find_any(struct mr_table *mrt,
925					     __be32 mcastgrp, int vifi)
926{
927	struct mfc_cache_cmp_arg arg = {
928			.mfc_mcastgrp = mcastgrp,
929			.mfc_origin = htonl(INADDR_ANY)
930	};
931
932	if (mcastgrp == htonl(INADDR_ANY))
933		return mr_mfc_find_any_parent(mrt, vifi);
934	return mr_mfc_find_any(mrt, vifi, &arg);
935}
936
937/* Look for a (S,G,iif) entry if parent != -1 */
938static struct mfc_cache *ipmr_cache_find_parent(struct mr_table *mrt,
939						__be32 origin, __be32 mcastgrp,
940						int parent)
941{
942	struct mfc_cache_cmp_arg arg = {
943			.mfc_mcastgrp = mcastgrp,
944			.mfc_origin = origin,
945	};
946
947	return mr_mfc_find_parent(mrt, &arg, parent);
948}
949
950/* Allocate a multicast cache entry */
951static struct mfc_cache *ipmr_cache_alloc(void)
952{
953	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
954
955	if (c) {
956		c->_c.mfc_un.res.last_assert = jiffies - MFC_ASSERT_THRESH - 1;
957		c->_c.mfc_un.res.minvif = MAXVIFS;
958		c->_c.free = ipmr_cache_free_rcu;
959		refcount_set(&c->_c.mfc_un.res.refcount, 1);
960	}
961	return c;
962}
963
964static struct mfc_cache *ipmr_cache_alloc_unres(void)
965{
966	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
967
968	if (c) {
969		skb_queue_head_init(&c->_c.mfc_un.unres.unresolved);
970		c->_c.mfc_un.unres.expires = jiffies + 10 * HZ;
971	}
972	return c;
973}
974
975/* A cache entry has gone into a resolved state from queued */
976static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
977			       struct mfc_cache *uc, struct mfc_cache *c)
978{
979	struct sk_buff *skb;
980	struct nlmsgerr *e;
981
982	/* Play the pending entries through our router */
983	while ((skb = __skb_dequeue(&uc->_c.mfc_un.unres.unresolved))) {
984		if (ip_hdr(skb)->version == 0) {
985			struct nlmsghdr *nlh = skb_pull(skb,
986							sizeof(struct iphdr));
987
988			if (mr_fill_mroute(mrt, skb, &c->_c,
989					   nlmsg_data(nlh)) > 0) {
990				nlh->nlmsg_len = skb_tail_pointer(skb) -
991						 (u8 *)nlh;
992			} else {
993				nlh->nlmsg_type = NLMSG_ERROR;
994				nlh->nlmsg_len = nlmsg_msg_size(sizeof(struct nlmsgerr));
995				skb_trim(skb, nlh->nlmsg_len);
996				e = nlmsg_data(nlh);
997				e->error = -EMSGSIZE;
998				memset(&e->msg, 0, sizeof(e->msg));
999			}
1000
1001			rtnl_unicast(skb, net, NETLINK_CB(skb).portid);
1002		} else {
1003			ip_mr_forward(net, mrt, skb->dev, skb, c, 0);
1004		}
1005	}
1006}
1007
1008/* Bounce a cache query up to mrouted and netlink.
1009 *
1010 * Called under mrt_lock.
1011 */
1012static int ipmr_cache_report(struct mr_table *mrt,
1013			     struct sk_buff *pkt, vifi_t vifi, int assert)
1014{
1015	const int ihl = ip_hdrlen(pkt);
1016	struct sock *mroute_sk;
1017	struct igmphdr *igmp;
1018	struct igmpmsg *msg;
1019	struct sk_buff *skb;
1020	int ret;
1021
1022	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE)
1023		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
1024	else
1025		skb = alloc_skb(128, GFP_ATOMIC);
1026
1027	if (!skb)
1028		return -ENOBUFS;
1029
1030	if (assert == IGMPMSG_WHOLEPKT || assert == IGMPMSG_WRVIFWHOLE) {
1031		/* Ugly, but we have no choice with this interface.
1032		 * Duplicate old header, fix ihl, length etc.
1033		 * And all this only to mangle msg->im_msgtype and
1034		 * to set msg->im_mbz to "mbz" :-)
1035		 */
1036		skb_push(skb, sizeof(struct iphdr));
1037		skb_reset_network_header(skb);
1038		skb_reset_transport_header(skb);
1039		msg = (struct igmpmsg *)skb_network_header(skb);
1040		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
1041		msg->im_msgtype = assert;
1042		msg->im_mbz = 0;
1043		if (assert == IGMPMSG_WRVIFWHOLE) {
1044			msg->im_vif = vifi;
1045			msg->im_vif_hi = vifi >> 8;
1046		} else {
1047			msg->im_vif = mrt->mroute_reg_vif_num;
1048			msg->im_vif_hi = mrt->mroute_reg_vif_num >> 8;
1049		}
1050		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
1051		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
1052					     sizeof(struct iphdr));
1053	} else {
1054		/* Copy the IP header */
1055		skb_set_network_header(skb, skb->len);
1056		skb_put(skb, ihl);
1057		skb_copy_to_linear_data(skb, pkt->data, ihl);
1058		/* Flag to the kernel this is a route add */
1059		ip_hdr(skb)->protocol = 0;
1060		msg = (struct igmpmsg *)skb_network_header(skb);
1061		msg->im_vif = vifi;
1062		msg->im_vif_hi = vifi >> 8;
1063		skb_dst_set(skb, dst_clone(skb_dst(pkt)));
1064		/* Add our header */
1065		igmp = skb_put(skb, sizeof(struct igmphdr));
1066		igmp->type = assert;
1067		msg->im_msgtype = assert;
1068		igmp->code = 0;
1069		ip_hdr(skb)->tot_len = htons(skb->len);	/* Fix the length */
1070		skb->transport_header = skb->network_header;
1071	}
1072
1073	rcu_read_lock();
1074	mroute_sk = rcu_dereference(mrt->mroute_sk);
1075	if (!mroute_sk) {
1076		rcu_read_unlock();
1077		kfree_skb(skb);
1078		return -EINVAL;
1079	}
1080
1081	igmpmsg_netlink_event(mrt, skb);
1082
1083	/* Deliver to mrouted */
1084	ret = sock_queue_rcv_skb(mroute_sk, skb);
1085	rcu_read_unlock();
1086	if (ret < 0) {
1087		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
1088		kfree_skb(skb);
1089	}
1090
1091	return ret;
1092}
1093
1094/* Queue a packet for resolution. It gets locked cache entry! */
1095static int ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi,
1096				 struct sk_buff *skb, struct net_device *dev)
1097{
1098	const struct iphdr *iph = ip_hdr(skb);
1099	struct mfc_cache *c;
1100	bool found = false;
1101	int err;
1102
1103	spin_lock_bh(&mfc_unres_lock);
1104	list_for_each_entry(c, &mrt->mfc_unres_queue, _c.list) {
1105		if (c->mfc_mcastgrp == iph->daddr &&
1106		    c->mfc_origin == iph->saddr) {
1107			found = true;
1108			break;
1109		}
1110	}
1111
1112	if (!found) {
1113		/* Create a new entry if allowable */
1114		c = ipmr_cache_alloc_unres();
1115		if (!c) {
1116			spin_unlock_bh(&mfc_unres_lock);
1117
1118			kfree_skb(skb);
1119			return -ENOBUFS;
1120		}
1121
1122		/* Fill in the new cache entry */
1123		c->_c.mfc_parent = -1;
1124		c->mfc_origin	= iph->saddr;
1125		c->mfc_mcastgrp	= iph->daddr;
1126
1127		/* Reflect first query at mrouted. */
1128		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1129
1130		if (err < 0) {
1131			/* If the report failed throw the cache entry
1132			   out - Brad Parker
1133			 */
1134			spin_unlock_bh(&mfc_unres_lock);
1135
1136			ipmr_cache_free(c);
1137			kfree_skb(skb);
1138			return err;
1139		}
1140
1141		atomic_inc(&mrt->cache_resolve_queue_len);
1142		list_add(&c->_c.list, &mrt->mfc_unres_queue);
1143		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1144
1145		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1146			mod_timer(&mrt->ipmr_expire_timer,
1147				  c->_c.mfc_un.unres.expires);
1148	}
1149
1150	/* See if we can append the packet */
1151	if (c->_c.mfc_un.unres.unresolved.qlen > 3) {
1152		kfree_skb(skb);
1153		err = -ENOBUFS;
1154	} else {
1155		if (dev) {
1156			skb->dev = dev;
1157			skb->skb_iif = dev->ifindex;
1158		}
1159		skb_queue_tail(&c->_c.mfc_un.unres.unresolved, skb);
1160		err = 0;
1161	}
1162
1163	spin_unlock_bh(&mfc_unres_lock);
1164	return err;
1165}
1166
1167/* MFC cache manipulation by user space mroute daemon */
1168
1169static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc, int parent)
1170{
1171	struct net *net = read_pnet(&mrt->net);
1172	struct mfc_cache *c;
1173
1174	/* The entries are added/deleted only under RTNL */
1175	rcu_read_lock();
1176	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1177				   mfc->mfcc_mcastgrp.s_addr, parent);
1178	rcu_read_unlock();
1179	if (!c)
1180		return -ENOENT;
1181	rhltable_remove(&mrt->mfc_hash, &c->_c.mnode, ipmr_rht_params);
1182	list_del_rcu(&c->_c.list);
1183	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, c, mrt->id);
1184	mroute_netlink_event(mrt, c, RTM_DELROUTE);
1185	mr_cache_put(&c->_c);
1186
1187	return 0;
1188}
1189
1190static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1191			struct mfcctl *mfc, int mrtsock, int parent)
1192{
1193	struct mfc_cache *uc, *c;
1194	struct mr_mfc *_uc;
1195	bool found;
1196	int ret;
1197
1198	if (mfc->mfcc_parent >= MAXVIFS)
1199		return -ENFILE;
1200
1201	/* The entries are added/deleted only under RTNL */
1202	rcu_read_lock();
1203	c = ipmr_cache_find_parent(mrt, mfc->mfcc_origin.s_addr,
1204				   mfc->mfcc_mcastgrp.s_addr, parent);
1205	rcu_read_unlock();
1206	if (c) {
1207		write_lock_bh(&mrt_lock);
1208		c->_c.mfc_parent = mfc->mfcc_parent;
1209		ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
1210		if (!mrtsock)
1211			c->_c.mfc_flags |= MFC_STATIC;
1212		write_unlock_bh(&mrt_lock);
1213		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, c,
1214					      mrt->id);
1215		mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1216		return 0;
1217	}
1218
1219	if (mfc->mfcc_mcastgrp.s_addr != htonl(INADDR_ANY) &&
1220	    !ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1221		return -EINVAL;
1222
1223	c = ipmr_cache_alloc();
1224	if (!c)
1225		return -ENOMEM;
1226
1227	c->mfc_origin = mfc->mfcc_origin.s_addr;
1228	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1229	c->_c.mfc_parent = mfc->mfcc_parent;
1230	ipmr_update_thresholds(mrt, &c->_c, mfc->mfcc_ttls);
1231	if (!mrtsock)
1232		c->_c.mfc_flags |= MFC_STATIC;
1233
1234	ret = rhltable_insert_key(&mrt->mfc_hash, &c->cmparg, &c->_c.mnode,
1235				  ipmr_rht_params);
1236	if (ret) {
1237		pr_err("ipmr: rhtable insert error %d\n", ret);
1238		ipmr_cache_free(c);
1239		return ret;
1240	}
1241	list_add_tail_rcu(&c->_c.list, &mrt->mfc_cache_list);
1242	/* Check to see if we resolved a queued list. If so we
1243	 * need to send on the frames and tidy up.
1244	 */
1245	found = false;
1246	spin_lock_bh(&mfc_unres_lock);
1247	list_for_each_entry(_uc, &mrt->mfc_unres_queue, list) {
1248		uc = (struct mfc_cache *)_uc;
1249		if (uc->mfc_origin == c->mfc_origin &&
1250		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1251			list_del(&_uc->list);
1252			atomic_dec(&mrt->cache_resolve_queue_len);
1253			found = true;
1254			break;
1255		}
1256	}
1257	if (list_empty(&mrt->mfc_unres_queue))
1258		del_timer(&mrt->ipmr_expire_timer);
1259	spin_unlock_bh(&mfc_unres_lock);
1260
1261	if (found) {
1262		ipmr_cache_resolve(net, mrt, uc, c);
1263		ipmr_cache_free(uc);
1264	}
1265	call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_ADD, c, mrt->id);
1266	mroute_netlink_event(mrt, c, RTM_NEWROUTE);
1267	return 0;
1268}
1269
1270/* Close the multicast socket, and clear the vif tables etc */
1271static void mroute_clean_tables(struct mr_table *mrt, int flags)
1272{
1273	struct net *net = read_pnet(&mrt->net);
1274	struct mr_mfc *c, *tmp;
1275	struct mfc_cache *cache;
1276	LIST_HEAD(list);
1277	int i;
1278
1279	/* Shut down all active vif entries */
1280	if (flags & (MRT_FLUSH_VIFS | MRT_FLUSH_VIFS_STATIC)) {
1281		for (i = 0; i < mrt->maxvif; i++) {
1282			if (((mrt->vif_table[i].flags & VIFF_STATIC) &&
1283			     !(flags & MRT_FLUSH_VIFS_STATIC)) ||
1284			    (!(mrt->vif_table[i].flags & VIFF_STATIC) && !(flags & MRT_FLUSH_VIFS)))
1285				continue;
1286			vif_delete(mrt, i, 0, &list);
1287		}
1288		unregister_netdevice_many(&list);
1289	}
1290
1291	/* Wipe the cache */
1292	if (flags & (MRT_FLUSH_MFC | MRT_FLUSH_MFC_STATIC)) {
1293		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
1294			if (((c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC_STATIC)) ||
1295			    (!(c->mfc_flags & MFC_STATIC) && !(flags & MRT_FLUSH_MFC)))
1296				continue;
1297			rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
1298			list_del_rcu(&c->list);
1299			cache = (struct mfc_cache *)c;
1300			call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
1301						      mrt->id);
1302			mroute_netlink_event(mrt, cache, RTM_DELROUTE);
1303			mr_cache_put(c);
1304		}
1305	}
1306
1307	if (flags & MRT_FLUSH_MFC) {
1308		if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1309			spin_lock_bh(&mfc_unres_lock);
1310			list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
1311				list_del(&c->list);
1312				cache = (struct mfc_cache *)c;
1313				mroute_netlink_event(mrt, cache, RTM_DELROUTE);
1314				ipmr_destroy_unres(mrt, cache);
1315			}
1316			spin_unlock_bh(&mfc_unres_lock);
1317		}
1318	}
1319}
1320
1321/* called from ip_ra_control(), before an RCU grace period,
1322 * we dont need to call synchronize_rcu() here
1323 */
1324static void mrtsock_destruct(struct sock *sk)
1325{
1326	struct net *net = sock_net(sk);
1327	struct mr_table *mrt;
1328
1329	rtnl_lock();
1330	ipmr_for_each_table(mrt, net) {
1331		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1332			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1333			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1334						    NETCONFA_MC_FORWARDING,
1335						    NETCONFA_IFINDEX_ALL,
1336						    net->ipv4.devconf_all);
1337			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1338			mroute_clean_tables(mrt, MRT_FLUSH_VIFS | MRT_FLUSH_MFC);
1339		}
1340	}
1341	rtnl_unlock();
1342}
1343
1344/* Socket options and virtual interface manipulation. The whole
1345 * virtual interface system is a complete heap, but unfortunately
1346 * that's how BSD mrouted happens to think. Maybe one day with a proper
1347 * MOSPF/PIM router set up we can clean this up.
1348 */
1349
1350int ip_mroute_setsockopt(struct sock *sk, int optname, sockptr_t optval,
1351			 unsigned int optlen)
1352{
1353	struct net *net = sock_net(sk);
1354	int val, ret = 0, parent = 0;
1355	struct mr_table *mrt;
1356	struct vifctl vif;
1357	struct mfcctl mfc;
1358	bool do_wrvifwhole;
1359	u32 uval;
1360
1361	/* There's one exception to the lock - MRT_DONE which needs to unlock */
1362	rtnl_lock();
1363	if (sk->sk_type != SOCK_RAW ||
1364	    inet_sk(sk)->inet_num != IPPROTO_IGMP) {
1365		ret = -EOPNOTSUPP;
1366		goto out_unlock;
1367	}
1368
1369	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1370	if (!mrt) {
1371		ret = -ENOENT;
1372		goto out_unlock;
1373	}
1374	if (optname != MRT_INIT) {
1375		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1376		    !ns_capable(net->user_ns, CAP_NET_ADMIN)) {
1377			ret = -EACCES;
1378			goto out_unlock;
1379		}
1380	}
1381
1382	switch (optname) {
1383	case MRT_INIT:
1384		if (optlen != sizeof(int)) {
1385			ret = -EINVAL;
1386			break;
1387		}
1388		if (rtnl_dereference(mrt->mroute_sk)) {
1389			ret = -EADDRINUSE;
1390			break;
1391		}
1392
1393		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1394		if (ret == 0) {
1395			rcu_assign_pointer(mrt->mroute_sk, sk);
1396			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1397			inet_netconf_notify_devconf(net, RTM_NEWNETCONF,
1398						    NETCONFA_MC_FORWARDING,
1399						    NETCONFA_IFINDEX_ALL,
1400						    net->ipv4.devconf_all);
1401		}
1402		break;
1403	case MRT_DONE:
1404		if (sk != rcu_access_pointer(mrt->mroute_sk)) {
1405			ret = -EACCES;
1406		} else {
1407			/* We need to unlock here because mrtsock_destruct takes
1408			 * care of rtnl itself and we can't change that due to
1409			 * the IP_ROUTER_ALERT setsockopt which runs without it.
1410			 */
1411			rtnl_unlock();
1412			ret = ip_ra_control(sk, 0, NULL);
1413			goto out;
1414		}
1415		break;
1416	case MRT_ADD_VIF:
1417	case MRT_DEL_VIF:
1418		if (optlen != sizeof(vif)) {
1419			ret = -EINVAL;
1420			break;
1421		}
1422		if (copy_from_sockptr(&vif, optval, sizeof(vif))) {
1423			ret = -EFAULT;
1424			break;
1425		}
1426		if (vif.vifc_vifi >= MAXVIFS) {
1427			ret = -ENFILE;
1428			break;
1429		}
1430		if (optname == MRT_ADD_VIF) {
1431			ret = vif_add(net, mrt, &vif,
1432				      sk == rtnl_dereference(mrt->mroute_sk));
1433		} else {
1434			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1435		}
1436		break;
1437	/* Manipulate the forwarding caches. These live
1438	 * in a sort of kernel/user symbiosis.
1439	 */
1440	case MRT_ADD_MFC:
1441	case MRT_DEL_MFC:
1442		parent = -1;
1443		fallthrough;
1444	case MRT_ADD_MFC_PROXY:
1445	case MRT_DEL_MFC_PROXY:
1446		if (optlen != sizeof(mfc)) {
1447			ret = -EINVAL;
1448			break;
1449		}
1450		if (copy_from_sockptr(&mfc, optval, sizeof(mfc))) {
1451			ret = -EFAULT;
1452			break;
1453		}
1454		if (parent == 0)
1455			parent = mfc.mfcc_parent;
1456		if (optname == MRT_DEL_MFC || optname == MRT_DEL_MFC_PROXY)
1457			ret = ipmr_mfc_delete(mrt, &mfc, parent);
1458		else
1459			ret = ipmr_mfc_add(net, mrt, &mfc,
1460					   sk == rtnl_dereference(mrt->mroute_sk),
1461					   parent);
1462		break;
1463	case MRT_FLUSH:
1464		if (optlen != sizeof(val)) {
1465			ret = -EINVAL;
1466			break;
1467		}
1468		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1469			ret = -EFAULT;
1470			break;
1471		}
1472		mroute_clean_tables(mrt, val);
1473		break;
1474	/* Control PIM assert. */
1475	case MRT_ASSERT:
1476		if (optlen != sizeof(val)) {
1477			ret = -EINVAL;
1478			break;
1479		}
1480		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1481			ret = -EFAULT;
1482			break;
1483		}
1484		mrt->mroute_do_assert = val;
1485		break;
1486	case MRT_PIM:
1487		if (!ipmr_pimsm_enabled()) {
1488			ret = -ENOPROTOOPT;
1489			break;
1490		}
1491		if (optlen != sizeof(val)) {
1492			ret = -EINVAL;
1493			break;
1494		}
1495		if (copy_from_sockptr(&val, optval, sizeof(val))) {
1496			ret = -EFAULT;
1497			break;
1498		}
1499
1500		do_wrvifwhole = (val == IGMPMSG_WRVIFWHOLE);
1501		val = !!val;
1502		if (val != mrt->mroute_do_pim) {
1503			mrt->mroute_do_pim = val;
1504			mrt->mroute_do_assert = val;
1505			mrt->mroute_do_wrvifwhole = do_wrvifwhole;
1506		}
1507		break;
1508	case MRT_TABLE:
1509		if (!IS_BUILTIN(CONFIG_IP_MROUTE_MULTIPLE_TABLES)) {
1510			ret = -ENOPROTOOPT;
1511			break;
1512		}
1513		if (optlen != sizeof(uval)) {
1514			ret = -EINVAL;
1515			break;
1516		}
1517		if (copy_from_sockptr(&uval, optval, sizeof(uval))) {
1518			ret = -EFAULT;
1519			break;
1520		}
1521
1522		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1523			ret = -EBUSY;
1524		} else {
1525			mrt = ipmr_new_table(net, uval);
1526			if (IS_ERR(mrt))
1527				ret = PTR_ERR(mrt);
1528			else
1529				raw_sk(sk)->ipmr_table = uval;
1530		}
1531		break;
1532	/* Spurious command, or MRT_VERSION which you cannot set. */
1533	default:
1534		ret = -ENOPROTOOPT;
1535	}
1536out_unlock:
1537	rtnl_unlock();
1538out:
1539	return ret;
1540}
1541
1542/* Getsock opt support for the multicast routing system. */
1543int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1544{
1545	int olr;
1546	int val;
1547	struct net *net = sock_net(sk);
1548	struct mr_table *mrt;
1549
1550	if (sk->sk_type != SOCK_RAW ||
1551	    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1552		return -EOPNOTSUPP;
1553
1554	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1555	if (!mrt)
1556		return -ENOENT;
1557
1558	switch (optname) {
1559	case MRT_VERSION:
1560		val = 0x0305;
1561		break;
1562	case MRT_PIM:
1563		if (!ipmr_pimsm_enabled())
1564			return -ENOPROTOOPT;
1565		val = mrt->mroute_do_pim;
1566		break;
1567	case MRT_ASSERT:
1568		val = mrt->mroute_do_assert;
1569		break;
1570	default:
1571		return -ENOPROTOOPT;
1572	}
1573
1574	if (get_user(olr, optlen))
1575		return -EFAULT;
1576	olr = min_t(unsigned int, olr, sizeof(int));
1577	if (olr < 0)
1578		return -EINVAL;
1579	if (put_user(olr, optlen))
1580		return -EFAULT;
1581	if (copy_to_user(optval, &val, olr))
1582		return -EFAULT;
1583	return 0;
1584}
1585
1586/* The IP multicast ioctl support routines. */
1587int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1588{
1589	struct sioc_sg_req sr;
1590	struct sioc_vif_req vr;
1591	struct vif_device *vif;
1592	struct mfc_cache *c;
1593	struct net *net = sock_net(sk);
1594	struct mr_table *mrt;
1595
1596	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1597	if (!mrt)
1598		return -ENOENT;
1599
1600	switch (cmd) {
1601	case SIOCGETVIFCNT:
1602		if (copy_from_user(&vr, arg, sizeof(vr)))
1603			return -EFAULT;
1604		if (vr.vifi >= mrt->maxvif)
1605			return -EINVAL;
1606		vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif);
1607		read_lock(&mrt_lock);
1608		vif = &mrt->vif_table[vr.vifi];
1609		if (VIF_EXISTS(mrt, vr.vifi)) {
1610			vr.icount = vif->pkt_in;
1611			vr.ocount = vif->pkt_out;
1612			vr.ibytes = vif->bytes_in;
1613			vr.obytes = vif->bytes_out;
1614			read_unlock(&mrt_lock);
1615
1616			if (copy_to_user(arg, &vr, sizeof(vr)))
1617				return -EFAULT;
1618			return 0;
1619		}
1620		read_unlock(&mrt_lock);
1621		return -EADDRNOTAVAIL;
1622	case SIOCGETSGCNT:
1623		if (copy_from_user(&sr, arg, sizeof(sr)))
1624			return -EFAULT;
1625
1626		rcu_read_lock();
1627		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1628		if (c) {
1629			sr.pktcnt = c->_c.mfc_un.res.pkt;
1630			sr.bytecnt = c->_c.mfc_un.res.bytes;
1631			sr.wrong_if = c->_c.mfc_un.res.wrong_if;
1632			rcu_read_unlock();
1633
1634			if (copy_to_user(arg, &sr, sizeof(sr)))
1635				return -EFAULT;
1636			return 0;
1637		}
1638		rcu_read_unlock();
1639		return -EADDRNOTAVAIL;
1640	default:
1641		return -ENOIOCTLCMD;
1642	}
1643}
1644
1645#ifdef CONFIG_COMPAT
1646struct compat_sioc_sg_req {
1647	struct in_addr src;
1648	struct in_addr grp;
1649	compat_ulong_t pktcnt;
1650	compat_ulong_t bytecnt;
1651	compat_ulong_t wrong_if;
1652};
1653
1654struct compat_sioc_vif_req {
1655	vifi_t	vifi;		/* Which iface */
1656	compat_ulong_t icount;
1657	compat_ulong_t ocount;
1658	compat_ulong_t ibytes;
1659	compat_ulong_t obytes;
1660};
1661
1662int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1663{
1664	struct compat_sioc_sg_req sr;
1665	struct compat_sioc_vif_req vr;
1666	struct vif_device *vif;
1667	struct mfc_cache *c;
1668	struct net *net = sock_net(sk);
1669	struct mr_table *mrt;
1670
1671	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1672	if (!mrt)
1673		return -ENOENT;
1674
1675	switch (cmd) {
1676	case SIOCGETVIFCNT:
1677		if (copy_from_user(&vr, arg, sizeof(vr)))
1678			return -EFAULT;
1679		if (vr.vifi >= mrt->maxvif)
1680			return -EINVAL;
1681		vr.vifi = array_index_nospec(vr.vifi, mrt->maxvif);
1682		read_lock(&mrt_lock);
1683		vif = &mrt->vif_table[vr.vifi];
1684		if (VIF_EXISTS(mrt, vr.vifi)) {
1685			vr.icount = vif->pkt_in;
1686			vr.ocount = vif->pkt_out;
1687			vr.ibytes = vif->bytes_in;
1688			vr.obytes = vif->bytes_out;
1689			read_unlock(&mrt_lock);
1690
1691			if (copy_to_user(arg, &vr, sizeof(vr)))
1692				return -EFAULT;
1693			return 0;
1694		}
1695		read_unlock(&mrt_lock);
1696		return -EADDRNOTAVAIL;
1697	case SIOCGETSGCNT:
1698		if (copy_from_user(&sr, arg, sizeof(sr)))
1699			return -EFAULT;
1700
1701		rcu_read_lock();
1702		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1703		if (c) {
1704			sr.pktcnt = c->_c.mfc_un.res.pkt;
1705			sr.bytecnt = c->_c.mfc_un.res.bytes;
1706			sr.wrong_if = c->_c.mfc_un.res.wrong_if;
1707			rcu_read_unlock();
1708
1709			if (copy_to_user(arg, &sr, sizeof(sr)))
1710				return -EFAULT;
1711			return 0;
1712		}
1713		rcu_read_unlock();
1714		return -EADDRNOTAVAIL;
1715	default:
1716		return -ENOIOCTLCMD;
1717	}
1718}
1719#endif
1720
1721static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1722{
1723	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1724	struct net *net = dev_net(dev);
1725	struct mr_table *mrt;
1726	struct vif_device *v;
1727	int ct;
1728
1729	if (event != NETDEV_UNREGISTER)
1730		return NOTIFY_DONE;
1731
1732	ipmr_for_each_table(mrt, net) {
1733		v = &mrt->vif_table[0];
1734		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1735			if (v->dev == dev)
1736				vif_delete(mrt, ct, 1, NULL);
1737		}
1738	}
1739	return NOTIFY_DONE;
1740}
1741
1742static struct notifier_block ip_mr_notifier = {
1743	.notifier_call = ipmr_device_event,
1744};
1745
1746/* Encapsulate a packet by attaching a valid IPIP header to it.
1747 * This avoids tunnel drivers and other mess and gives us the speed so
1748 * important for multicast video.
1749 */
1750static void ip_encap(struct net *net, struct sk_buff *skb,
1751		     __be32 saddr, __be32 daddr)
1752{
1753	struct iphdr *iph;
1754	const struct iphdr *old_iph = ip_hdr(skb);
1755
1756	skb_push(skb, sizeof(struct iphdr));
1757	skb->transport_header = skb->network_header;
1758	skb_reset_network_header(skb);
1759	iph = ip_hdr(skb);
1760
1761	iph->version	=	4;
1762	iph->tos	=	old_iph->tos;
1763	iph->ttl	=	old_iph->ttl;
1764	iph->frag_off	=	0;
1765	iph->daddr	=	daddr;
1766	iph->saddr	=	saddr;
1767	iph->protocol	=	IPPROTO_IPIP;
1768	iph->ihl	=	5;
1769	iph->tot_len	=	htons(skb->len);
1770	ip_select_ident(net, skb, NULL);
1771	ip_send_check(iph);
1772
1773	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1774	nf_reset_ct(skb);
1775}
1776
1777static inline int ipmr_forward_finish(struct net *net, struct sock *sk,
1778				      struct sk_buff *skb)
1779{
1780	struct ip_options *opt = &(IPCB(skb)->opt);
1781
1782	IP_INC_STATS(net, IPSTATS_MIB_OUTFORWDATAGRAMS);
1783	IP_ADD_STATS(net, IPSTATS_MIB_OUTOCTETS, skb->len);
1784
1785	if (unlikely(opt->optlen))
1786		ip_forward_options(skb);
1787
1788	return dst_output(net, sk, skb);
1789}
1790
1791#ifdef CONFIG_NET_SWITCHDEV
1792static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1793				   int in_vifi, int out_vifi)
1794{
1795	struct vif_device *out_vif = &mrt->vif_table[out_vifi];
1796	struct vif_device *in_vif = &mrt->vif_table[in_vifi];
1797
1798	if (!skb->offload_l3_fwd_mark)
1799		return false;
1800	if (!out_vif->dev_parent_id.id_len || !in_vif->dev_parent_id.id_len)
1801		return false;
1802	return netdev_phys_item_id_same(&out_vif->dev_parent_id,
1803					&in_vif->dev_parent_id);
1804}
1805#else
1806static bool ipmr_forward_offloaded(struct sk_buff *skb, struct mr_table *mrt,
1807				   int in_vifi, int out_vifi)
1808{
1809	return false;
1810}
1811#endif
1812
1813/* Processing handlers for ipmr_forward */
1814
1815static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1816			    int in_vifi, struct sk_buff *skb, int vifi)
1817{
1818	const struct iphdr *iph = ip_hdr(skb);
1819	struct vif_device *vif = &mrt->vif_table[vifi];
1820	struct net_device *dev;
1821	struct rtable *rt;
1822	struct flowi4 fl4;
1823	int    encap = 0;
1824
1825	if (!vif->dev)
1826		goto out_free;
1827
1828	if (vif->flags & VIFF_REGISTER) {
1829		vif->pkt_out++;
1830		vif->bytes_out += skb->len;
1831		vif->dev->stats.tx_bytes += skb->len;
1832		vif->dev->stats.tx_packets++;
1833		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1834		goto out_free;
1835	}
1836
1837	if (ipmr_forward_offloaded(skb, mrt, in_vifi, vifi))
1838		goto out_free;
1839
1840	if (vif->flags & VIFF_TUNNEL) {
1841		rt = ip_route_output_ports(net, &fl4, NULL,
1842					   vif->remote, vif->local,
1843					   0, 0,
1844					   IPPROTO_IPIP,
1845					   RT_TOS(iph->tos), vif->link);
1846		if (IS_ERR(rt))
1847			goto out_free;
1848		encap = sizeof(struct iphdr);
1849	} else {
1850		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1851					   0, 0,
1852					   IPPROTO_IPIP,
1853					   RT_TOS(iph->tos), vif->link);
1854		if (IS_ERR(rt))
1855			goto out_free;
1856	}
1857
1858	dev = rt->dst.dev;
1859
1860	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1861		/* Do not fragment multicasts. Alas, IPv4 does not
1862		 * allow to send ICMP, so that packets will disappear
1863		 * to blackhole.
1864		 */
1865		IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS);
1866		ip_rt_put(rt);
1867		goto out_free;
1868	}
1869
1870	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1871
1872	if (skb_cow(skb, encap)) {
1873		ip_rt_put(rt);
1874		goto out_free;
1875	}
1876
1877	vif->pkt_out++;
1878	vif->bytes_out += skb->len;
1879
1880	skb_dst_drop(skb);
1881	skb_dst_set(skb, &rt->dst);
1882	ip_decrease_ttl(ip_hdr(skb));
1883
1884	/* FIXME: forward and output firewalls used to be called here.
1885	 * What do we do with netfilter? -- RR
1886	 */
1887	if (vif->flags & VIFF_TUNNEL) {
1888		ip_encap(net, skb, vif->local, vif->remote);
1889		/* FIXME: extra output firewall step used to be here. --RR */
1890		vif->dev->stats.tx_packets++;
1891		vif->dev->stats.tx_bytes += skb->len;
1892	}
1893
1894	IPCB(skb)->flags |= IPSKB_FORWARDED;
1895
1896	/* RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1897	 * not only before forwarding, but after forwarding on all output
1898	 * interfaces. It is clear, if mrouter runs a multicasting
1899	 * program, it should receive packets not depending to what interface
1900	 * program is joined.
1901	 * If we will not make it, the program will have to join on all
1902	 * interfaces. On the other hand, multihoming host (or router, but
1903	 * not mrouter) cannot join to more than one interface - it will
1904	 * result in receiving multiple packets.
1905	 */
1906	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD,
1907		net, NULL, skb, skb->dev, dev,
1908		ipmr_forward_finish);
1909	return;
1910
1911out_free:
1912	kfree_skb(skb);
1913}
1914
1915static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1916{
1917	int ct;
1918
1919	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1920		if (mrt->vif_table[ct].dev == dev)
1921			break;
1922	}
1923	return ct;
1924}
1925
1926/* "local" means that we should preserve one skb (for local delivery) */
1927static void ip_mr_forward(struct net *net, struct mr_table *mrt,
1928			  struct net_device *dev, struct sk_buff *skb,
1929			  struct mfc_cache *c, int local)
1930{
1931	int true_vifi = ipmr_find_vif(mrt, dev);
1932	int psend = -1;
1933	int vif, ct;
1934
1935	vif = c->_c.mfc_parent;
1936	c->_c.mfc_un.res.pkt++;
1937	c->_c.mfc_un.res.bytes += skb->len;
1938	c->_c.mfc_un.res.lastuse = jiffies;
1939
1940	if (c->mfc_origin == htonl(INADDR_ANY) && true_vifi >= 0) {
1941		struct mfc_cache *cache_proxy;
1942
1943		/* For an (*,G) entry, we only check that the incomming
1944		 * interface is part of the static tree.
1945		 */
1946		cache_proxy = mr_mfc_find_any_parent(mrt, vif);
1947		if (cache_proxy &&
1948		    cache_proxy->_c.mfc_un.res.ttls[true_vifi] < 255)
1949			goto forward;
1950	}
1951
1952	/* Wrong interface: drop packet and (maybe) send PIM assert. */
1953	if (mrt->vif_table[vif].dev != dev) {
1954		if (rt_is_output_route(skb_rtable(skb))) {
1955			/* It is our own packet, looped back.
1956			 * Very complicated situation...
1957			 *
1958			 * The best workaround until routing daemons will be
1959			 * fixed is not to redistribute packet, if it was
1960			 * send through wrong interface. It means, that
1961			 * multicast applications WILL NOT work for
1962			 * (S,G), which have default multicast route pointing
1963			 * to wrong oif. In any case, it is not a good
1964			 * idea to use multicasting applications on router.
1965			 */
1966			goto dont_forward;
1967		}
1968
1969		c->_c.mfc_un.res.wrong_if++;
1970
1971		if (true_vifi >= 0 && mrt->mroute_do_assert &&
1972		    /* pimsm uses asserts, when switching from RPT to SPT,
1973		     * so that we cannot check that packet arrived on an oif.
1974		     * It is bad, but otherwise we would need to move pretty
1975		     * large chunk of pimd to kernel. Ough... --ANK
1976		     */
1977		    (mrt->mroute_do_pim ||
1978		     c->_c.mfc_un.res.ttls[true_vifi] < 255) &&
1979		    time_after(jiffies,
1980			       c->_c.mfc_un.res.last_assert +
1981			       MFC_ASSERT_THRESH)) {
1982			c->_c.mfc_un.res.last_assert = jiffies;
1983			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1984			if (mrt->mroute_do_wrvifwhole)
1985				ipmr_cache_report(mrt, skb, true_vifi,
1986						  IGMPMSG_WRVIFWHOLE);
1987		}
1988		goto dont_forward;
1989	}
1990
1991forward:
1992	mrt->vif_table[vif].pkt_in++;
1993	mrt->vif_table[vif].bytes_in += skb->len;
1994
1995	/* Forward the frame */
1996	if (c->mfc_origin == htonl(INADDR_ANY) &&
1997	    c->mfc_mcastgrp == htonl(INADDR_ANY)) {
1998		if (true_vifi >= 0 &&
1999		    true_vifi != c->_c.mfc_parent &&
2000		    ip_hdr(skb)->ttl >
2001				c->_c.mfc_un.res.ttls[c->_c.mfc_parent]) {
2002			/* It's an (*,*) entry and the packet is not coming from
2003			 * the upstream: forward the packet to the upstream
2004			 * only.
2005			 */
2006			psend = c->_c.mfc_parent;
2007			goto last_forward;
2008		}
2009		goto dont_forward;
2010	}
2011	for (ct = c->_c.mfc_un.res.maxvif - 1;
2012	     ct >= c->_c.mfc_un.res.minvif; ct--) {
2013		/* For (*,G) entry, don't forward to the incoming interface */
2014		if ((c->mfc_origin != htonl(INADDR_ANY) ||
2015		     ct != true_vifi) &&
2016		    ip_hdr(skb)->ttl > c->_c.mfc_un.res.ttls[ct]) {
2017			if (psend != -1) {
2018				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2019
2020				if (skb2)
2021					ipmr_queue_xmit(net, mrt, true_vifi,
2022							skb2, psend);
2023			}
2024			psend = ct;
2025		}
2026	}
2027last_forward:
2028	if (psend != -1) {
2029		if (local) {
2030			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2031
2032			if (skb2)
2033				ipmr_queue_xmit(net, mrt, true_vifi, skb2,
2034						psend);
2035		} else {
2036			ipmr_queue_xmit(net, mrt, true_vifi, skb, psend);
2037			return;
2038		}
2039	}
2040
2041dont_forward:
2042	if (!local)
2043		kfree_skb(skb);
2044}
2045
2046static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
2047{
2048	struct rtable *rt = skb_rtable(skb);
2049	struct iphdr *iph = ip_hdr(skb);
2050	struct flowi4 fl4 = {
2051		.daddr = iph->daddr,
2052		.saddr = iph->saddr,
2053		.flowi4_tos = RT_TOS(iph->tos),
2054		.flowi4_oif = (rt_is_output_route(rt) ?
2055			       skb->dev->ifindex : 0),
2056		.flowi4_iif = (rt_is_output_route(rt) ?
2057			       LOOPBACK_IFINDEX :
2058			       skb->dev->ifindex),
2059		.flowi4_mark = skb->mark,
2060	};
2061	struct mr_table *mrt;
2062	int err;
2063
2064	err = ipmr_fib_lookup(net, &fl4, &mrt);
2065	if (err)
2066		return ERR_PTR(err);
2067	return mrt;
2068}
2069
2070/* Multicast packets for forwarding arrive here
2071 * Called with rcu_read_lock();
2072 */
2073int ip_mr_input(struct sk_buff *skb)
2074{
2075	struct mfc_cache *cache;
2076	struct net *net = dev_net(skb->dev);
2077	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
2078	struct mr_table *mrt;
2079	struct net_device *dev;
2080
2081	/* skb->dev passed in is the loX master dev for vrfs.
2082	 * As there are no vifs associated with loopback devices,
2083	 * get the proper interface that does have a vif associated with it.
2084	 */
2085	dev = skb->dev;
2086	if (netif_is_l3_master(skb->dev)) {
2087		dev = dev_get_by_index_rcu(net, IPCB(skb)->iif);
2088		if (!dev) {
2089			kfree_skb(skb);
2090			return -ENODEV;
2091		}
2092	}
2093
2094	/* Packet is looped back after forward, it should not be
2095	 * forwarded second time, but still can be delivered locally.
2096	 */
2097	if (IPCB(skb)->flags & IPSKB_FORWARDED)
2098		goto dont_forward;
2099
2100	mrt = ipmr_rt_fib_lookup(net, skb);
2101	if (IS_ERR(mrt)) {
2102		kfree_skb(skb);
2103		return PTR_ERR(mrt);
2104	}
2105	if (!local) {
2106		if (IPCB(skb)->opt.router_alert) {
2107			if (ip_call_ra_chain(skb))
2108				return 0;
2109		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
2110			/* IGMPv1 (and broken IGMPv2 implementations sort of
2111			 * Cisco IOS <= 11.2(8)) do not put router alert
2112			 * option to IGMP packets destined to routable
2113			 * groups. It is very bad, because it means
2114			 * that we can forward NO IGMP messages.
2115			 */
2116			struct sock *mroute_sk;
2117
2118			mroute_sk = rcu_dereference(mrt->mroute_sk);
2119			if (mroute_sk) {
2120				nf_reset_ct(skb);
2121				raw_rcv(mroute_sk, skb);
2122				return 0;
2123			}
2124		    }
2125	}
2126
2127	/* already under rcu_read_lock() */
2128	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
2129	if (!cache) {
2130		int vif = ipmr_find_vif(mrt, dev);
2131
2132		if (vif >= 0)
2133			cache = ipmr_cache_find_any(mrt, ip_hdr(skb)->daddr,
2134						    vif);
2135	}
2136
2137	/* No usable cache entry */
2138	if (!cache) {
2139		int vif;
2140
2141		if (local) {
2142			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
2143			ip_local_deliver(skb);
2144			if (!skb2)
2145				return -ENOBUFS;
2146			skb = skb2;
2147		}
2148
2149		read_lock(&mrt_lock);
2150		vif = ipmr_find_vif(mrt, dev);
2151		if (vif >= 0) {
2152			int err2 = ipmr_cache_unresolved(mrt, vif, skb, dev);
2153			read_unlock(&mrt_lock);
2154
2155			return err2;
2156		}
2157		read_unlock(&mrt_lock);
2158		kfree_skb(skb);
2159		return -ENODEV;
2160	}
2161
2162	read_lock(&mrt_lock);
2163	ip_mr_forward(net, mrt, dev, skb, cache, local);
2164	read_unlock(&mrt_lock);
2165
2166	if (local)
2167		return ip_local_deliver(skb);
2168
2169	return 0;
2170
2171dont_forward:
2172	if (local)
2173		return ip_local_deliver(skb);
2174	kfree_skb(skb);
2175	return 0;
2176}
2177
2178#ifdef CONFIG_IP_PIMSM_V1
2179/* Handle IGMP messages of PIMv1 */
2180int pim_rcv_v1(struct sk_buff *skb)
2181{
2182	struct igmphdr *pim;
2183	struct net *net = dev_net(skb->dev);
2184	struct mr_table *mrt;
2185
2186	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2187		goto drop;
2188
2189	pim = igmp_hdr(skb);
2190
2191	mrt = ipmr_rt_fib_lookup(net, skb);
2192	if (IS_ERR(mrt))
2193		goto drop;
2194	if (!mrt->mroute_do_pim ||
2195	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
2196		goto drop;
2197
2198	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2199drop:
2200		kfree_skb(skb);
2201	}
2202	return 0;
2203}
2204#endif
2205
2206#ifdef CONFIG_IP_PIMSM_V2
2207static int pim_rcv(struct sk_buff *skb)
2208{
2209	struct pimreghdr *pim;
2210	struct net *net = dev_net(skb->dev);
2211	struct mr_table *mrt;
2212
2213	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
2214		goto drop;
2215
2216	pim = (struct pimreghdr *)skb_transport_header(skb);
2217	if (pim->type != ((PIM_VERSION << 4) | (PIM_TYPE_REGISTER)) ||
2218	    (pim->flags & PIM_NULL_REGISTER) ||
2219	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2220	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2221		goto drop;
2222
2223	mrt = ipmr_rt_fib_lookup(net, skb);
2224	if (IS_ERR(mrt))
2225		goto drop;
2226	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2227drop:
2228		kfree_skb(skb);
2229	}
2230	return 0;
2231}
2232#endif
2233
2234int ipmr_get_route(struct net *net, struct sk_buff *skb,
2235		   __be32 saddr, __be32 daddr,
2236		   struct rtmsg *rtm, u32 portid)
2237{
2238	struct mfc_cache *cache;
2239	struct mr_table *mrt;
2240	int err;
2241
2242	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2243	if (!mrt)
2244		return -ENOENT;
2245
2246	rcu_read_lock();
2247	cache = ipmr_cache_find(mrt, saddr, daddr);
2248	if (!cache && skb->dev) {
2249		int vif = ipmr_find_vif(mrt, skb->dev);
2250
2251		if (vif >= 0)
2252			cache = ipmr_cache_find_any(mrt, daddr, vif);
2253	}
2254	if (!cache) {
2255		struct sk_buff *skb2;
2256		struct iphdr *iph;
2257		struct net_device *dev;
2258		int vif = -1;
2259
2260		dev = skb->dev;
2261		read_lock(&mrt_lock);
2262		if (dev)
2263			vif = ipmr_find_vif(mrt, dev);
2264		if (vif < 0) {
2265			read_unlock(&mrt_lock);
2266			rcu_read_unlock();
2267			return -ENODEV;
2268		}
2269
2270		skb2 = skb_realloc_headroom(skb, sizeof(struct iphdr));
2271		if (!skb2) {
2272			read_unlock(&mrt_lock);
2273			rcu_read_unlock();
2274			return -ENOMEM;
2275		}
2276
2277		NETLINK_CB(skb2).portid = portid;
2278		skb_push(skb2, sizeof(struct iphdr));
2279		skb_reset_network_header(skb2);
2280		iph = ip_hdr(skb2);
2281		iph->ihl = sizeof(struct iphdr) >> 2;
2282		iph->saddr = saddr;
2283		iph->daddr = daddr;
2284		iph->version = 0;
2285		err = ipmr_cache_unresolved(mrt, vif, skb2, dev);
2286		read_unlock(&mrt_lock);
2287		rcu_read_unlock();
2288		return err;
2289	}
2290
2291	read_lock(&mrt_lock);
2292	err = mr_fill_mroute(mrt, skb, &cache->_c, rtm);
2293	read_unlock(&mrt_lock);
2294	rcu_read_unlock();
2295	return err;
2296}
2297
2298static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2299			    u32 portid, u32 seq, struct mfc_cache *c, int cmd,
2300			    int flags)
2301{
2302	struct nlmsghdr *nlh;
2303	struct rtmsg *rtm;
2304	int err;
2305
2306	nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
2307	if (!nlh)
2308		return -EMSGSIZE;
2309
2310	rtm = nlmsg_data(nlh);
2311	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2312	rtm->rtm_dst_len  = 32;
2313	rtm->rtm_src_len  = 32;
2314	rtm->rtm_tos      = 0;
2315	rtm->rtm_table    = mrt->id;
2316	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2317		goto nla_put_failure;
2318	rtm->rtm_type     = RTN_MULTICAST;
2319	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2320	if (c->_c.mfc_flags & MFC_STATIC)
2321		rtm->rtm_protocol = RTPROT_STATIC;
2322	else
2323		rtm->rtm_protocol = RTPROT_MROUTED;
2324	rtm->rtm_flags    = 0;
2325
2326	if (nla_put_in_addr(skb, RTA_SRC, c->mfc_origin) ||
2327	    nla_put_in_addr(skb, RTA_DST, c->mfc_mcastgrp))
2328		goto nla_put_failure;
2329	err = mr_fill_mroute(mrt, skb, &c->_c, rtm);
2330	/* do not break the dump if cache is unresolved */
2331	if (err < 0 && err != -ENOENT)
2332		goto nla_put_failure;
2333
2334	nlmsg_end(skb, nlh);
2335	return 0;
2336
2337nla_put_failure:
2338	nlmsg_cancel(skb, nlh);
2339	return -EMSGSIZE;
2340}
2341
2342static int _ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2343			     u32 portid, u32 seq, struct mr_mfc *c, int cmd,
2344			     int flags)
2345{
2346	return ipmr_fill_mroute(mrt, skb, portid, seq, (struct mfc_cache *)c,
2347				cmd, flags);
2348}
2349
2350static size_t mroute_msgsize(bool unresolved, int maxvif)
2351{
2352	size_t len =
2353		NLMSG_ALIGN(sizeof(struct rtmsg))
2354		+ nla_total_size(4)	/* RTA_TABLE */
2355		+ nla_total_size(4)	/* RTA_SRC */
2356		+ nla_total_size(4)	/* RTA_DST */
2357		;
2358
2359	if (!unresolved)
2360		len = len
2361		      + nla_total_size(4)	/* RTA_IIF */
2362		      + nla_total_size(0)	/* RTA_MULTIPATH */
2363		      + maxvif * NLA_ALIGN(sizeof(struct rtnexthop))
2364						/* RTA_MFC_STATS */
2365		      + nla_total_size_64bit(sizeof(struct rta_mfc_stats))
2366		;
2367
2368	return len;
2369}
2370
2371static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
2372				 int cmd)
2373{
2374	struct net *net = read_pnet(&mrt->net);
2375	struct sk_buff *skb;
2376	int err = -ENOBUFS;
2377
2378	skb = nlmsg_new(mroute_msgsize(mfc->_c.mfc_parent >= MAXVIFS,
2379				       mrt->maxvif),
2380			GFP_ATOMIC);
2381	if (!skb)
2382		goto errout;
2383
2384	err = ipmr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
2385	if (err < 0)
2386		goto errout;
2387
2388	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE, NULL, GFP_ATOMIC);
2389	return;
2390
2391errout:
2392	kfree_skb(skb);
2393	if (err < 0)
2394		rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE, err);
2395}
2396
2397static size_t igmpmsg_netlink_msgsize(size_t payloadlen)
2398{
2399	size_t len =
2400		NLMSG_ALIGN(sizeof(struct rtgenmsg))
2401		+ nla_total_size(1)	/* IPMRA_CREPORT_MSGTYPE */
2402		+ nla_total_size(4)	/* IPMRA_CREPORT_VIF_ID */
2403		+ nla_total_size(4)	/* IPMRA_CREPORT_SRC_ADDR */
2404		+ nla_total_size(4)	/* IPMRA_CREPORT_DST_ADDR */
2405		+ nla_total_size(4)	/* IPMRA_CREPORT_TABLE */
2406					/* IPMRA_CREPORT_PKT */
2407		+ nla_total_size(payloadlen)
2408		;
2409
2410	return len;
2411}
2412
2413static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt)
2414{
2415	struct net *net = read_pnet(&mrt->net);
2416	struct nlmsghdr *nlh;
2417	struct rtgenmsg *rtgenm;
2418	struct igmpmsg *msg;
2419	struct sk_buff *skb;
2420	struct nlattr *nla;
2421	int payloadlen;
2422
2423	payloadlen = pkt->len - sizeof(struct igmpmsg);
2424	msg = (struct igmpmsg *)skb_network_header(pkt);
2425
2426	skb = nlmsg_new(igmpmsg_netlink_msgsize(payloadlen), GFP_ATOMIC);
2427	if (!skb)
2428		goto errout;
2429
2430	nlh = nlmsg_put(skb, 0, 0, RTM_NEWCACHEREPORT,
2431			sizeof(struct rtgenmsg), 0);
2432	if (!nlh)
2433		goto errout;
2434	rtgenm = nlmsg_data(nlh);
2435	rtgenm->rtgen_family = RTNL_FAMILY_IPMR;
2436	if (nla_put_u8(skb, IPMRA_CREPORT_MSGTYPE, msg->im_msgtype) ||
2437	    nla_put_u32(skb, IPMRA_CREPORT_VIF_ID, msg->im_vif | (msg->im_vif_hi << 8)) ||
2438	    nla_put_in_addr(skb, IPMRA_CREPORT_SRC_ADDR,
2439			    msg->im_src.s_addr) ||
2440	    nla_put_in_addr(skb, IPMRA_CREPORT_DST_ADDR,
2441			    msg->im_dst.s_addr) ||
2442	    nla_put_u32(skb, IPMRA_CREPORT_TABLE, mrt->id))
2443		goto nla_put_failure;
2444
2445	nla = nla_reserve(skb, IPMRA_CREPORT_PKT, payloadlen);
2446	if (!nla || skb_copy_bits(pkt, sizeof(struct igmpmsg),
2447				  nla_data(nla), payloadlen))
2448		goto nla_put_failure;
2449
2450	nlmsg_end(skb, nlh);
2451
2452	rtnl_notify(skb, net, 0, RTNLGRP_IPV4_MROUTE_R, NULL, GFP_ATOMIC);
2453	return;
2454
2455nla_put_failure:
2456	nlmsg_cancel(skb, nlh);
2457errout:
2458	kfree_skb(skb);
2459	rtnl_set_sk_err(net, RTNLGRP_IPV4_MROUTE_R, -ENOBUFS);
2460}
2461
2462static int ipmr_rtm_valid_getroute_req(struct sk_buff *skb,
2463				       const struct nlmsghdr *nlh,
2464				       struct nlattr **tb,
2465				       struct netlink_ext_ack *extack)
2466{
2467	struct rtmsg *rtm;
2468	int i, err;
2469
2470	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2471		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for multicast route get request");
2472		return -EINVAL;
2473	}
2474
2475	if (!netlink_strict_get_check(skb))
2476		return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
2477					      rtm_ipv4_policy, extack);
2478
2479	rtm = nlmsg_data(nlh);
2480	if ((rtm->rtm_src_len && rtm->rtm_src_len != 32) ||
2481	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 32) ||
2482	    rtm->rtm_tos || rtm->rtm_table || rtm->rtm_protocol ||
2483	    rtm->rtm_scope || rtm->rtm_type || rtm->rtm_flags) {
2484		NL_SET_ERR_MSG(extack, "ipv4: Invalid values in header for multicast route get request");
2485		return -EINVAL;
2486	}
2487
2488	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2489					    rtm_ipv4_policy, extack);
2490	if (err)
2491		return err;
2492
2493	if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
2494	    (tb[RTA_DST] && !rtm->rtm_dst_len)) {
2495		NL_SET_ERR_MSG(extack, "ipv4: rtm_src_len and rtm_dst_len must be 32 for IPv4");
2496		return -EINVAL;
2497	}
2498
2499	for (i = 0; i <= RTA_MAX; i++) {
2500		if (!tb[i])
2501			continue;
2502
2503		switch (i) {
2504		case RTA_SRC:
2505		case RTA_DST:
2506		case RTA_TABLE:
2507			break;
2508		default:
2509			NL_SET_ERR_MSG(extack, "ipv4: Unsupported attribute in multicast route get request");
2510			return -EINVAL;
2511		}
2512	}
2513
2514	return 0;
2515}
2516
2517static int ipmr_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
2518			     struct netlink_ext_ack *extack)
2519{
2520	struct net *net = sock_net(in_skb->sk);
2521	struct nlattr *tb[RTA_MAX + 1];
2522	struct sk_buff *skb = NULL;
2523	struct mfc_cache *cache;
2524	struct mr_table *mrt;
2525	__be32 src, grp;
2526	u32 tableid;
2527	int err;
2528
2529	err = ipmr_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
2530	if (err < 0)
2531		goto errout;
2532
2533	src = tb[RTA_SRC] ? nla_get_in_addr(tb[RTA_SRC]) : 0;
2534	grp = tb[RTA_DST] ? nla_get_in_addr(tb[RTA_DST]) : 0;
2535	tableid = tb[RTA_TABLE] ? nla_get_u32(tb[RTA_TABLE]) : 0;
2536
2537	mrt = ipmr_get_table(net, tableid ? tableid : RT_TABLE_DEFAULT);
2538	if (!mrt) {
2539		err = -ENOENT;
2540		goto errout_free;
2541	}
2542
2543	/* entries are added/deleted only under RTNL */
2544	rcu_read_lock();
2545	cache = ipmr_cache_find(mrt, src, grp);
2546	rcu_read_unlock();
2547	if (!cache) {
2548		err = -ENOENT;
2549		goto errout_free;
2550	}
2551
2552	skb = nlmsg_new(mroute_msgsize(false, mrt->maxvif), GFP_KERNEL);
2553	if (!skb) {
2554		err = -ENOBUFS;
2555		goto errout_free;
2556	}
2557
2558	err = ipmr_fill_mroute(mrt, skb, NETLINK_CB(in_skb).portid,
2559			       nlh->nlmsg_seq, cache,
2560			       RTM_NEWROUTE, 0);
2561	if (err < 0)
2562		goto errout_free;
2563
2564	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
2565
2566errout:
2567	return err;
2568
2569errout_free:
2570	kfree_skb(skb);
2571	goto errout;
2572}
2573
2574static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2575{
2576	struct fib_dump_filter filter = {};
2577	int err;
2578
2579	if (cb->strict_check) {
2580		err = ip_valid_fib_dump_req(sock_net(skb->sk), cb->nlh,
2581					    &filter, cb);
2582		if (err < 0)
2583			return err;
2584	}
2585
2586	if (filter.table_id) {
2587		struct mr_table *mrt;
2588
2589		mrt = ipmr_get_table(sock_net(skb->sk), filter.table_id);
2590		if (!mrt) {
2591			if (rtnl_msg_family(cb->nlh) != RTNL_FAMILY_IPMR)
2592				return skb->len;
2593
2594			NL_SET_ERR_MSG(cb->extack, "ipv4: MR table does not exist");
2595			return -ENOENT;
2596		}
2597		err = mr_table_dump(mrt, skb, cb, _ipmr_fill_mroute,
2598				    &mfc_unres_lock, &filter);
2599		return skb->len ? : err;
2600	}
2601
2602	return mr_rtm_dumproute(skb, cb, ipmr_mr_table_iter,
2603				_ipmr_fill_mroute, &mfc_unres_lock, &filter);
2604}
2605
2606static const struct nla_policy rtm_ipmr_policy[RTA_MAX + 1] = {
2607	[RTA_SRC]	= { .type = NLA_U32 },
2608	[RTA_DST]	= { .type = NLA_U32 },
2609	[RTA_IIF]	= { .type = NLA_U32 },
2610	[RTA_TABLE]	= { .type = NLA_U32 },
2611	[RTA_MULTIPATH]	= { .len = sizeof(struct rtnexthop) },
2612};
2613
2614static bool ipmr_rtm_validate_proto(unsigned char rtm_protocol)
2615{
2616	switch (rtm_protocol) {
2617	case RTPROT_STATIC:
2618	case RTPROT_MROUTED:
2619		return true;
2620	}
2621	return false;
2622}
2623
2624static int ipmr_nla_get_ttls(const struct nlattr *nla, struct mfcctl *mfcc)
2625{
2626	struct rtnexthop *rtnh = nla_data(nla);
2627	int remaining = nla_len(nla), vifi = 0;
2628
2629	while (rtnh_ok(rtnh, remaining)) {
2630		mfcc->mfcc_ttls[vifi] = rtnh->rtnh_hops;
2631		if (++vifi == MAXVIFS)
2632			break;
2633		rtnh = rtnh_next(rtnh, &remaining);
2634	}
2635
2636	return remaining > 0 ? -EINVAL : vifi;
2637}
2638
2639/* returns < 0 on error, 0 for ADD_MFC and 1 for ADD_MFC_PROXY */
2640static int rtm_to_ipmr_mfcc(struct net *net, struct nlmsghdr *nlh,
2641			    struct mfcctl *mfcc, int *mrtsock,
2642			    struct mr_table **mrtret,
2643			    struct netlink_ext_ack *extack)
2644{
2645	struct net_device *dev = NULL;
2646	u32 tblid = RT_TABLE_DEFAULT;
2647	struct mr_table *mrt;
2648	struct nlattr *attr;
2649	struct rtmsg *rtm;
2650	int ret, rem;
2651
2652	ret = nlmsg_validate_deprecated(nlh, sizeof(*rtm), RTA_MAX,
2653					rtm_ipmr_policy, extack);
2654	if (ret < 0)
2655		goto out;
2656	rtm = nlmsg_data(nlh);
2657
2658	ret = -EINVAL;
2659	if (rtm->rtm_family != RTNL_FAMILY_IPMR || rtm->rtm_dst_len != 32 ||
2660	    rtm->rtm_type != RTN_MULTICAST ||
2661	    rtm->rtm_scope != RT_SCOPE_UNIVERSE ||
2662	    !ipmr_rtm_validate_proto(rtm->rtm_protocol))
2663		goto out;
2664
2665	memset(mfcc, 0, sizeof(*mfcc));
2666	mfcc->mfcc_parent = -1;
2667	ret = 0;
2668	nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), rem) {
2669		switch (nla_type(attr)) {
2670		case RTA_SRC:
2671			mfcc->mfcc_origin.s_addr = nla_get_be32(attr);
2672			break;
2673		case RTA_DST:
2674			mfcc->mfcc_mcastgrp.s_addr = nla_get_be32(attr);
2675			break;
2676		case RTA_IIF:
2677			dev = __dev_get_by_index(net, nla_get_u32(attr));
2678			if (!dev) {
2679				ret = -ENODEV;
2680				goto out;
2681			}
2682			break;
2683		case RTA_MULTIPATH:
2684			if (ipmr_nla_get_ttls(attr, mfcc) < 0) {
2685				ret = -EINVAL;
2686				goto out;
2687			}
2688			break;
2689		case RTA_PREFSRC:
2690			ret = 1;
2691			break;
2692		case RTA_TABLE:
2693			tblid = nla_get_u32(attr);
2694			break;
2695		}
2696	}
2697	mrt = ipmr_get_table(net, tblid);
2698	if (!mrt) {
2699		ret = -ENOENT;
2700		goto out;
2701	}
2702	*mrtret = mrt;
2703	*mrtsock = rtm->rtm_protocol == RTPROT_MROUTED ? 1 : 0;
2704	if (dev)
2705		mfcc->mfcc_parent = ipmr_find_vif(mrt, dev);
2706
2707out:
2708	return ret;
2709}
2710
2711/* takes care of both newroute and delroute */
2712static int ipmr_rtm_route(struct sk_buff *skb, struct nlmsghdr *nlh,
2713			  struct netlink_ext_ack *extack)
2714{
2715	struct net *net = sock_net(skb->sk);
2716	int ret, mrtsock, parent;
2717	struct mr_table *tbl;
2718	struct mfcctl mfcc;
2719
2720	mrtsock = 0;
2721	tbl = NULL;
2722	ret = rtm_to_ipmr_mfcc(net, nlh, &mfcc, &mrtsock, &tbl, extack);
2723	if (ret < 0)
2724		return ret;
2725
2726	parent = ret ? mfcc.mfcc_parent : -1;
2727	if (nlh->nlmsg_type == RTM_NEWROUTE)
2728		return ipmr_mfc_add(net, tbl, &mfcc, mrtsock, parent);
2729	else
2730		return ipmr_mfc_delete(tbl, &mfcc, parent);
2731}
2732
2733static bool ipmr_fill_table(struct mr_table *mrt, struct sk_buff *skb)
2734{
2735	u32 queue_len = atomic_read(&mrt->cache_resolve_queue_len);
2736
2737	if (nla_put_u32(skb, IPMRA_TABLE_ID, mrt->id) ||
2738	    nla_put_u32(skb, IPMRA_TABLE_CACHE_RES_QUEUE_LEN, queue_len) ||
2739	    nla_put_s32(skb, IPMRA_TABLE_MROUTE_REG_VIF_NUM,
2740			mrt->mroute_reg_vif_num) ||
2741	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_ASSERT,
2742		       mrt->mroute_do_assert) ||
2743	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_PIM, mrt->mroute_do_pim) ||
2744	    nla_put_u8(skb, IPMRA_TABLE_MROUTE_DO_WRVIFWHOLE,
2745		       mrt->mroute_do_wrvifwhole))
2746		return false;
2747
2748	return true;
2749}
2750
2751static bool ipmr_fill_vif(struct mr_table *mrt, u32 vifid, struct sk_buff *skb)
2752{
2753	struct nlattr *vif_nest;
2754	struct vif_device *vif;
2755
2756	/* if the VIF doesn't exist just continue */
2757	if (!VIF_EXISTS(mrt, vifid))
2758		return true;
2759
2760	vif = &mrt->vif_table[vifid];
2761	vif_nest = nla_nest_start_noflag(skb, IPMRA_VIF);
2762	if (!vif_nest)
2763		return false;
2764	if (nla_put_u32(skb, IPMRA_VIFA_IFINDEX, vif->dev->ifindex) ||
2765	    nla_put_u32(skb, IPMRA_VIFA_VIF_ID, vifid) ||
2766	    nla_put_u16(skb, IPMRA_VIFA_FLAGS, vif->flags) ||
2767	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_IN, vif->bytes_in,
2768			      IPMRA_VIFA_PAD) ||
2769	    nla_put_u64_64bit(skb, IPMRA_VIFA_BYTES_OUT, vif->bytes_out,
2770			      IPMRA_VIFA_PAD) ||
2771	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_IN, vif->pkt_in,
2772			      IPMRA_VIFA_PAD) ||
2773	    nla_put_u64_64bit(skb, IPMRA_VIFA_PACKETS_OUT, vif->pkt_out,
2774			      IPMRA_VIFA_PAD) ||
2775	    nla_put_be32(skb, IPMRA_VIFA_LOCAL_ADDR, vif->local) ||
2776	    nla_put_be32(skb, IPMRA_VIFA_REMOTE_ADDR, vif->remote)) {
2777		nla_nest_cancel(skb, vif_nest);
2778		return false;
2779	}
2780	nla_nest_end(skb, vif_nest);
2781
2782	return true;
2783}
2784
2785static int ipmr_valid_dumplink(const struct nlmsghdr *nlh,
2786			       struct netlink_ext_ack *extack)
2787{
2788	struct ifinfomsg *ifm;
2789
2790	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifm))) {
2791		NL_SET_ERR_MSG(extack, "ipv4: Invalid header for ipmr link dump");
2792		return -EINVAL;
2793	}
2794
2795	if (nlmsg_attrlen(nlh, sizeof(*ifm))) {
2796		NL_SET_ERR_MSG(extack, "Invalid data after header in ipmr link dump");
2797		return -EINVAL;
2798	}
2799
2800	ifm = nlmsg_data(nlh);
2801	if (ifm->__ifi_pad || ifm->ifi_type || ifm->ifi_flags ||
2802	    ifm->ifi_change || ifm->ifi_index) {
2803		NL_SET_ERR_MSG(extack, "Invalid values in header for ipmr link dump request");
2804		return -EINVAL;
2805	}
2806
2807	return 0;
2808}
2809
2810static int ipmr_rtm_dumplink(struct sk_buff *skb, struct netlink_callback *cb)
2811{
2812	struct net *net = sock_net(skb->sk);
2813	struct nlmsghdr *nlh = NULL;
2814	unsigned int t = 0, s_t;
2815	unsigned int e = 0, s_e;
2816	struct mr_table *mrt;
2817
2818	if (cb->strict_check) {
2819		int err = ipmr_valid_dumplink(cb->nlh, cb->extack);
2820
2821		if (err < 0)
2822			return err;
2823	}
2824
2825	s_t = cb->args[0];
2826	s_e = cb->args[1];
2827
2828	ipmr_for_each_table(mrt, net) {
2829		struct nlattr *vifs, *af;
2830		struct ifinfomsg *hdr;
2831		u32 i;
2832
2833		if (t < s_t)
2834			goto skip_table;
2835		nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
2836				cb->nlh->nlmsg_seq, RTM_NEWLINK,
2837				sizeof(*hdr), NLM_F_MULTI);
2838		if (!nlh)
2839			break;
2840
2841		hdr = nlmsg_data(nlh);
2842		memset(hdr, 0, sizeof(*hdr));
2843		hdr->ifi_family = RTNL_FAMILY_IPMR;
2844
2845		af = nla_nest_start_noflag(skb, IFLA_AF_SPEC);
2846		if (!af) {
2847			nlmsg_cancel(skb, nlh);
2848			goto out;
2849		}
2850
2851		if (!ipmr_fill_table(mrt, skb)) {
2852			nlmsg_cancel(skb, nlh);
2853			goto out;
2854		}
2855
2856		vifs = nla_nest_start_noflag(skb, IPMRA_TABLE_VIFS);
2857		if (!vifs) {
2858			nla_nest_end(skb, af);
2859			nlmsg_end(skb, nlh);
2860			goto out;
2861		}
2862		for (i = 0; i < mrt->maxvif; i++) {
2863			if (e < s_e)
2864				goto skip_entry;
2865			if (!ipmr_fill_vif(mrt, i, skb)) {
2866				nla_nest_end(skb, vifs);
2867				nla_nest_end(skb, af);
2868				nlmsg_end(skb, nlh);
2869				goto out;
2870			}
2871skip_entry:
2872			e++;
2873		}
2874		s_e = 0;
2875		e = 0;
2876		nla_nest_end(skb, vifs);
2877		nla_nest_end(skb, af);
2878		nlmsg_end(skb, nlh);
2879skip_table:
2880		t++;
2881	}
2882
2883out:
2884	cb->args[1] = e;
2885	cb->args[0] = t;
2886
2887	return skb->len;
2888}
2889
2890#ifdef CONFIG_PROC_FS
2891/* The /proc interfaces to multicast routing :
2892 * /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2893 */
2894
2895static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2896	__acquires(mrt_lock)
2897{
2898	struct mr_vif_iter *iter = seq->private;
2899	struct net *net = seq_file_net(seq);
2900	struct mr_table *mrt;
2901
2902	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2903	if (!mrt)
2904		return ERR_PTR(-ENOENT);
2905
2906	iter->mrt = mrt;
2907
2908	read_lock(&mrt_lock);
2909	return mr_vif_seq_start(seq, pos);
2910}
2911
2912static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2913	__releases(mrt_lock)
2914{
2915	read_unlock(&mrt_lock);
2916}
2917
2918static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2919{
2920	struct mr_vif_iter *iter = seq->private;
2921	struct mr_table *mrt = iter->mrt;
2922
2923	if (v == SEQ_START_TOKEN) {
2924		seq_puts(seq,
2925			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2926	} else {
2927		const struct vif_device *vif = v;
2928		const char *name =  vif->dev ?
2929				    vif->dev->name : "none";
2930
2931		seq_printf(seq,
2932			   "%2td %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2933			   vif - mrt->vif_table,
2934			   name, vif->bytes_in, vif->pkt_in,
2935			   vif->bytes_out, vif->pkt_out,
2936			   vif->flags, vif->local, vif->remote);
2937	}
2938	return 0;
2939}
2940
2941static const struct seq_operations ipmr_vif_seq_ops = {
2942	.start = ipmr_vif_seq_start,
2943	.next  = mr_vif_seq_next,
2944	.stop  = ipmr_vif_seq_stop,
2945	.show  = ipmr_vif_seq_show,
2946};
2947
2948static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2949{
2950	struct net *net = seq_file_net(seq);
2951	struct mr_table *mrt;
2952
2953	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2954	if (!mrt)
2955		return ERR_PTR(-ENOENT);
2956
2957	return mr_mfc_seq_start(seq, pos, mrt, &mfc_unres_lock);
2958}
2959
2960static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2961{
2962	int n;
2963
2964	if (v == SEQ_START_TOKEN) {
2965		seq_puts(seq,
2966		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2967	} else {
2968		const struct mfc_cache *mfc = v;
2969		const struct mr_mfc_iter *it = seq->private;
2970		const struct mr_table *mrt = it->mrt;
2971
2972		seq_printf(seq, "%08X %08X %-3hd",
2973			   (__force u32) mfc->mfc_mcastgrp,
2974			   (__force u32) mfc->mfc_origin,
2975			   mfc->_c.mfc_parent);
2976
2977		if (it->cache != &mrt->mfc_unres_queue) {
2978			seq_printf(seq, " %8lu %8lu %8lu",
2979				   mfc->_c.mfc_un.res.pkt,
2980				   mfc->_c.mfc_un.res.bytes,
2981				   mfc->_c.mfc_un.res.wrong_if);
2982			for (n = mfc->_c.mfc_un.res.minvif;
2983			     n < mfc->_c.mfc_un.res.maxvif; n++) {
2984				if (VIF_EXISTS(mrt, n) &&
2985				    mfc->_c.mfc_un.res.ttls[n] < 255)
2986					seq_printf(seq,
2987					   " %2d:%-3d",
2988					   n, mfc->_c.mfc_un.res.ttls[n]);
2989			}
2990		} else {
2991			/* unresolved mfc_caches don't contain
2992			 * pkt, bytes and wrong_if values
2993			 */
2994			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
2995		}
2996		seq_putc(seq, '\n');
2997	}
2998	return 0;
2999}
3000
3001static const struct seq_operations ipmr_mfc_seq_ops = {
3002	.start = ipmr_mfc_seq_start,
3003	.next  = mr_mfc_seq_next,
3004	.stop  = mr_mfc_seq_stop,
3005	.show  = ipmr_mfc_seq_show,
3006};
3007#endif
3008
3009#ifdef CONFIG_IP_PIMSM_V2
3010static const struct net_protocol pim_protocol = {
3011	.handler	=	pim_rcv,
3012	.netns_ok	=	1,
3013};
3014#endif
3015
3016static unsigned int ipmr_seq_read(struct net *net)
3017{
3018	ASSERT_RTNL();
3019
3020	return net->ipv4.ipmr_seq + ipmr_rules_seq_read(net);
3021}
3022
3023static int ipmr_dump(struct net *net, struct notifier_block *nb,
3024		     struct netlink_ext_ack *extack)
3025{
3026	return mr_dump(net, nb, RTNL_FAMILY_IPMR, ipmr_rules_dump,
3027		       ipmr_mr_table_iter, &mrt_lock, extack);
3028}
3029
3030static const struct fib_notifier_ops ipmr_notifier_ops_template = {
3031	.family		= RTNL_FAMILY_IPMR,
3032	.fib_seq_read	= ipmr_seq_read,
3033	.fib_dump	= ipmr_dump,
3034	.owner		= THIS_MODULE,
3035};
3036
3037static int __net_init ipmr_notifier_init(struct net *net)
3038{
3039	struct fib_notifier_ops *ops;
3040
3041	net->ipv4.ipmr_seq = 0;
3042
3043	ops = fib_notifier_ops_register(&ipmr_notifier_ops_template, net);
3044	if (IS_ERR(ops))
3045		return PTR_ERR(ops);
3046	net->ipv4.ipmr_notifier_ops = ops;
3047
3048	return 0;
3049}
3050
3051static void __net_exit ipmr_notifier_exit(struct net *net)
3052{
3053	fib_notifier_ops_unregister(net->ipv4.ipmr_notifier_ops);
3054	net->ipv4.ipmr_notifier_ops = NULL;
3055}
3056
3057/* Setup for IP multicast routing */
3058static int __net_init ipmr_net_init(struct net *net)
3059{
3060	int err;
3061
3062	err = ipmr_notifier_init(net);
3063	if (err)
3064		goto ipmr_notifier_fail;
3065
3066	err = ipmr_rules_init(net);
3067	if (err < 0)
3068		goto ipmr_rules_fail;
3069
3070#ifdef CONFIG_PROC_FS
3071	err = -ENOMEM;
3072	if (!proc_create_net("ip_mr_vif", 0, net->proc_net, &ipmr_vif_seq_ops,
3073			sizeof(struct mr_vif_iter)))
3074		goto proc_vif_fail;
3075	if (!proc_create_net("ip_mr_cache", 0, net->proc_net, &ipmr_mfc_seq_ops,
3076			sizeof(struct mr_mfc_iter)))
3077		goto proc_cache_fail;
3078#endif
3079	return 0;
3080
3081#ifdef CONFIG_PROC_FS
3082proc_cache_fail:
3083	remove_proc_entry("ip_mr_vif", net->proc_net);
3084proc_vif_fail:
3085	ipmr_rules_exit(net);
3086#endif
3087ipmr_rules_fail:
3088	ipmr_notifier_exit(net);
3089ipmr_notifier_fail:
3090	return err;
3091}
3092
3093static void __net_exit ipmr_net_exit(struct net *net)
3094{
3095#ifdef CONFIG_PROC_FS
3096	remove_proc_entry("ip_mr_cache", net->proc_net);
3097	remove_proc_entry("ip_mr_vif", net->proc_net);
3098#endif
3099	ipmr_notifier_exit(net);
3100	ipmr_rules_exit(net);
3101}
3102
3103static struct pernet_operations ipmr_net_ops = {
3104	.init = ipmr_net_init,
3105	.exit = ipmr_net_exit,
3106};
3107
3108int __init ip_mr_init(void)
3109{
3110	int err;
3111
3112	mrt_cachep = kmem_cache_create("ip_mrt_cache",
3113				       sizeof(struct mfc_cache),
3114				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
3115				       NULL);
3116
3117	err = register_pernet_subsys(&ipmr_net_ops);
3118	if (err)
3119		goto reg_pernet_fail;
3120
3121	err = register_netdevice_notifier(&ip_mr_notifier);
3122	if (err)
3123		goto reg_notif_fail;
3124#ifdef CONFIG_IP_PIMSM_V2
3125	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
3126		pr_err("%s: can't add PIM protocol\n", __func__);
3127		err = -EAGAIN;
3128		goto add_proto_fail;
3129	}
3130#endif
3131	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
3132		      ipmr_rtm_getroute, ipmr_rtm_dumproute, 0);
3133	rtnl_register(RTNL_FAMILY_IPMR, RTM_NEWROUTE,
3134		      ipmr_rtm_route, NULL, 0);
3135	rtnl_register(RTNL_FAMILY_IPMR, RTM_DELROUTE,
3136		      ipmr_rtm_route, NULL, 0);
3137
3138	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETLINK,
3139		      NULL, ipmr_rtm_dumplink, 0);
3140	return 0;
3141
3142#ifdef CONFIG_IP_PIMSM_V2
3143add_proto_fail:
3144	unregister_netdevice_notifier(&ip_mr_notifier);
3145#endif
3146reg_notif_fail:
3147	unregister_pernet_subsys(&ipmr_net_ops);
3148reg_pernet_fail:
3149	kmem_cache_destroy(mrt_cachep);
3150	return err;
3151}
3152