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/ipip.h>
  65#include <net/checksum.h>
  66#include <net/netlink.h>
  67#include <net/fib_rules.h>
  68
  69#if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
  70#define CONFIG_IP_PIMSM	1
  71#endif
  72
  73struct mr_table {
  74	struct list_head	list;
  75#ifdef CONFIG_NET_NS
  76	struct net		*net;
  77#endif
  78	u32			id;
  79	struct sock __rcu	*mroute_sk;
  80	struct timer_list	ipmr_expire_timer;
  81	struct list_head	mfc_unres_queue;
  82	struct list_head	mfc_cache_array[MFC_LINES];
  83	struct vif_device	vif_table[MAXVIFS];
  84	int			maxvif;
  85	atomic_t		cache_resolve_queue_len;
  86	int			mroute_do_assert;
  87	int			mroute_do_pim;
  88#if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
  89	int			mroute_reg_vif_num;
  90#endif
  91};
  92
  93struct ipmr_rule {
  94	struct fib_rule		common;
  95};
  96
  97struct ipmr_result {
  98	struct mr_table		*mrt;
  99};
 100
 101/* Big lock, protecting vif table, mrt cache and mroute socket state.
 102 * Note that the changes are semaphored via rtnl_lock.
 103 */
 104
 105static DEFINE_RWLOCK(mrt_lock);
 106
 107/*
 108 *	Multicast router control variables
 109 */
 110
 111#define VIF_EXISTS(_mrt, _idx) ((_mrt)->vif_table[_idx].dev != NULL)
 112
 113/* Special spinlock for queue of unresolved entries */
 114static DEFINE_SPINLOCK(mfc_unres_lock);
 115
 116/* We return to original Alan's scheme. Hash table of resolved
 117 * entries is changed only in process context and protected
 118 * with weak lock mrt_lock. Queue of unresolved entries is protected
 119 * with strong spinlock mfc_unres_lock.
 120 *
 121 * In this case data path is free of exclusive locks at all.
 122 */
 123
 124static struct kmem_cache *mrt_cachep __read_mostly;
 125
 126static struct mr_table *ipmr_new_table(struct net *net, u32 id);
 127static void ipmr_free_table(struct mr_table *mrt);
 128
 129static int ip_mr_forward(struct net *net, struct mr_table *mrt,
 130			 struct sk_buff *skb, struct mfc_cache *cache,
 131			 int local);
 132static int ipmr_cache_report(struct mr_table *mrt,
 133			     struct sk_buff *pkt, vifi_t vifi, int assert);
 134static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
 135			      struct mfc_cache *c, struct rtmsg *rtm);
 136static void mroute_clean_tables(struct mr_table *mrt);
 137static void ipmr_expire_process(unsigned long arg);
 138
 139#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
 140#define ipmr_for_each_table(mrt, net) \
 141	list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
 142
 143static struct mr_table *ipmr_get_table(struct net *net, u32 id)
 144{
 145	struct mr_table *mrt;
 146
 147	ipmr_for_each_table(mrt, net) {
 148		if (mrt->id == id)
 149			return mrt;
 150	}
 151	return NULL;
 152}
 153
 154static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
 155			   struct mr_table **mrt)
 156{
 157	struct ipmr_result res;
 158	struct fib_lookup_arg arg = { .result = &res, };
 159	int err;
 160
 161	err = fib_rules_lookup(net->ipv4.mr_rules_ops,
 162			       flowi4_to_flowi(flp4), 0, &arg);
 163	if (err < 0)
 164		return err;
 165	*mrt = res.mrt;
 166	return 0;
 167}
 168
 169static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
 170			    int flags, struct fib_lookup_arg *arg)
 171{
 172	struct ipmr_result *res = arg->result;
 173	struct mr_table *mrt;
 174
 175	switch (rule->action) {
 176	case FR_ACT_TO_TBL:
 177		break;
 178	case FR_ACT_UNREACHABLE:
 179		return -ENETUNREACH;
 180	case FR_ACT_PROHIBIT:
 181		return -EACCES;
 182	case FR_ACT_BLACKHOLE:
 183	default:
 184		return -EINVAL;
 185	}
 186
 187	mrt = ipmr_get_table(rule->fr_net, rule->table);
 188	if (mrt == NULL)
 189		return -EAGAIN;
 190	res->mrt = mrt;
 191	return 0;
 192}
 193
 194static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
 195{
 196	return 1;
 197}
 198
 199static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
 200	FRA_GENERIC_POLICY,
 201};
 202
 203static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
 204			       struct fib_rule_hdr *frh, struct nlattr **tb)
 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_initdata 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	.default_pref	= fib_default_rule_pref,
 233	.fill		= ipmr_rule_fill,
 234	.nlgroup	= RTNLGRP_IPV4_RULE,
 235	.policy		= ipmr_rule_policy,
 236	.owner		= THIS_MODULE,
 237};
 238
 239static int __net_init ipmr_rules_init(struct net *net)
 240{
 241	struct fib_rules_ops *ops;
 242	struct mr_table *mrt;
 243	int err;
 244
 245	ops = fib_rules_register(&ipmr_rules_ops_template, net);
 246	if (IS_ERR(ops))
 247		return PTR_ERR(ops);
 248
 249	INIT_LIST_HEAD(&net->ipv4.mr_tables);
 250
 251	mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
 252	if (mrt == NULL) {
 253		err = -ENOMEM;
 254		goto err1;
 255	}
 256
 257	err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
 258	if (err < 0)
 259		goto err2;
 260
 261	net->ipv4.mr_rules_ops = ops;
 262	return 0;
 263
 264err2:
 265	kfree(mrt);
 266err1:
 267	fib_rules_unregister(ops);
 268	return err;
 269}
 270
 271static void __net_exit ipmr_rules_exit(struct net *net)
 272{
 273	struct mr_table *mrt, *next;
 274
 275	list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
 276		list_del(&mrt->list);
 277		ipmr_free_table(mrt);
 278	}
 279	fib_rules_unregister(net->ipv4.mr_rules_ops);
 280}
 281#else
 282#define ipmr_for_each_table(mrt, net) \
 283	for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
 284
 285static struct mr_table *ipmr_get_table(struct net *net, u32 id)
 286{
 287	return net->ipv4.mrt;
 288}
 289
 290static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
 291			   struct mr_table **mrt)
 292{
 293	*mrt = net->ipv4.mrt;
 294	return 0;
 295}
 296
 297static int __net_init ipmr_rules_init(struct net *net)
 298{
 299	net->ipv4.mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
 300	return net->ipv4.mrt ? 0 : -ENOMEM;
 301}
 302
 303static void __net_exit ipmr_rules_exit(struct net *net)
 304{
 305	ipmr_free_table(net->ipv4.mrt);
 306}
 307#endif
 308
 309static struct mr_table *ipmr_new_table(struct net *net, u32 id)
 310{
 311	struct mr_table *mrt;
 312	unsigned int i;
 313
 314	mrt = ipmr_get_table(net, id);
 315	if (mrt != NULL)
 316		return mrt;
 317
 318	mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
 319	if (mrt == NULL)
 320		return NULL;
 321	write_pnet(&mrt->net, net);
 322	mrt->id = id;
 323
 324	/* Forwarding cache */
 325	for (i = 0; i < MFC_LINES; i++)
 326		INIT_LIST_HEAD(&mrt->mfc_cache_array[i]);
 327
 328	INIT_LIST_HEAD(&mrt->mfc_unres_queue);
 329
 330	setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
 331		    (unsigned long)mrt);
 332
 333#ifdef CONFIG_IP_PIMSM
 334	mrt->mroute_reg_vif_num = -1;
 335#endif
 336#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
 337	list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
 338#endif
 339	return mrt;
 340}
 341
 342static void ipmr_free_table(struct mr_table *mrt)
 343{
 344	del_timer_sync(&mrt->ipmr_expire_timer);
 345	mroute_clean_tables(mrt);
 346	kfree(mrt);
 347}
 348
 349/* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
 350
 351static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
 352{
 353	struct net *net = dev_net(dev);
 354
 355	dev_close(dev);
 356
 357	dev = __dev_get_by_name(net, "tunl0");
 358	if (dev) {
 359		const struct net_device_ops *ops = dev->netdev_ops;
 360		struct ifreq ifr;
 361		struct ip_tunnel_parm p;
 362
 363		memset(&p, 0, sizeof(p));
 364		p.iph.daddr = v->vifc_rmt_addr.s_addr;
 365		p.iph.saddr = v->vifc_lcl_addr.s_addr;
 366		p.iph.version = 4;
 367		p.iph.ihl = 5;
 368		p.iph.protocol = IPPROTO_IPIP;
 369		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
 370		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
 371
 372		if (ops->ndo_do_ioctl) {
 373			mm_segment_t oldfs = get_fs();
 374
 375			set_fs(KERNEL_DS);
 376			ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
 377			set_fs(oldfs);
 378		}
 379	}
 380}
 381
 382static
 383struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
 384{
 385	struct net_device  *dev;
 386
 387	dev = __dev_get_by_name(net, "tunl0");
 388
 389	if (dev) {
 390		const struct net_device_ops *ops = dev->netdev_ops;
 391		int err;
 392		struct ifreq ifr;
 393		struct ip_tunnel_parm p;
 394		struct in_device  *in_dev;
 395
 396		memset(&p, 0, sizeof(p));
 397		p.iph.daddr = v->vifc_rmt_addr.s_addr;
 398		p.iph.saddr = v->vifc_lcl_addr.s_addr;
 399		p.iph.version = 4;
 400		p.iph.ihl = 5;
 401		p.iph.protocol = IPPROTO_IPIP;
 402		sprintf(p.name, "dvmrp%d", v->vifc_vifi);
 403		ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
 404
 405		if (ops->ndo_do_ioctl) {
 406			mm_segment_t oldfs = get_fs();
 407
 408			set_fs(KERNEL_DS);
 409			err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
 410			set_fs(oldfs);
 411		} else {
 412			err = -EOPNOTSUPP;
 413		}
 414		dev = NULL;
 415
 416		if (err == 0 &&
 417		    (dev = __dev_get_by_name(net, p.name)) != NULL) {
 418			dev->flags |= IFF_MULTICAST;
 419
 420			in_dev = __in_dev_get_rtnl(dev);
 421			if (in_dev == NULL)
 422				goto failure;
 423
 424			ipv4_devconf_setall(in_dev);
 425			IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
 426
 427			if (dev_open(dev))
 428				goto failure;
 429			dev_hold(dev);
 430		}
 431	}
 432	return dev;
 433
 434failure:
 435	/* allow the register to be completed before unregistering. */
 436	rtnl_unlock();
 437	rtnl_lock();
 438
 439	unregister_netdevice(dev);
 440	return NULL;
 441}
 442
 443#ifdef CONFIG_IP_PIMSM
 444
 445static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
 446{
 447	struct net *net = dev_net(dev);
 448	struct mr_table *mrt;
 449	struct flowi4 fl4 = {
 450		.flowi4_oif	= dev->ifindex,
 451		.flowi4_iif	= skb->skb_iif,
 452		.flowi4_mark	= skb->mark,
 453	};
 454	int err;
 455
 456	err = ipmr_fib_lookup(net, &fl4, &mrt);
 457	if (err < 0) {
 458		kfree_skb(skb);
 459		return err;
 460	}
 461
 462	read_lock(&mrt_lock);
 463	dev->stats.tx_bytes += skb->len;
 464	dev->stats.tx_packets++;
 465	ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
 466	read_unlock(&mrt_lock);
 467	kfree_skb(skb);
 468	return NETDEV_TX_OK;
 469}
 470
 471static const struct net_device_ops reg_vif_netdev_ops = {
 472	.ndo_start_xmit	= reg_vif_xmit,
 473};
 474
 475static void reg_vif_setup(struct net_device *dev)
 476{
 477	dev->type		= ARPHRD_PIMREG;
 478	dev->mtu		= ETH_DATA_LEN - sizeof(struct iphdr) - 8;
 479	dev->flags		= IFF_NOARP;
 480	dev->netdev_ops		= &reg_vif_netdev_ops,
 481	dev->destructor		= free_netdev;
 482	dev->features		|= NETIF_F_NETNS_LOCAL;
 483}
 484
 485static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
 486{
 487	struct net_device *dev;
 488	struct in_device *in_dev;
 489	char name[IFNAMSIZ];
 490
 491	if (mrt->id == RT_TABLE_DEFAULT)
 492		sprintf(name, "pimreg");
 493	else
 494		sprintf(name, "pimreg%u", mrt->id);
 495
 496	dev = alloc_netdev(0, name, reg_vif_setup);
 497
 498	if (dev == NULL)
 499		return NULL;
 500
 501	dev_net_set(dev, net);
 502
 503	if (register_netdevice(dev)) {
 504		free_netdev(dev);
 505		return NULL;
 506	}
 507	dev->iflink = 0;
 508
 509	rcu_read_lock();
 510	in_dev = __in_dev_get_rcu(dev);
 511	if (!in_dev) {
 512		rcu_read_unlock();
 513		goto failure;
 514	}
 515
 516	ipv4_devconf_setall(in_dev);
 517	IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
 518	rcu_read_unlock();
 519
 520	if (dev_open(dev))
 521		goto failure;
 522
 523	dev_hold(dev);
 524
 525	return dev;
 526
 527failure:
 528	/* allow the register to be completed before unregistering. */
 529	rtnl_unlock();
 530	rtnl_lock();
 531
 532	unregister_netdevice(dev);
 533	return NULL;
 534}
 535#endif
 536
 537/*
 538 *	Delete a VIF entry
 539 *	@notify: Set to 1, if the caller is a notifier_call
 540 */
 541
 542static int vif_delete(struct mr_table *mrt, int vifi, int notify,
 543		      struct list_head *head)
 544{
 545	struct vif_device *v;
 546	struct net_device *dev;
 547	struct in_device *in_dev;
 548
 549	if (vifi < 0 || vifi >= mrt->maxvif)
 550		return -EADDRNOTAVAIL;
 551
 552	v = &mrt->vif_table[vifi];
 553
 554	write_lock_bh(&mrt_lock);
 555	dev = v->dev;
 556	v->dev = NULL;
 557
 558	if (!dev) {
 559		write_unlock_bh(&mrt_lock);
 560		return -EADDRNOTAVAIL;
 561	}
 562
 563#ifdef CONFIG_IP_PIMSM
 564	if (vifi == mrt->mroute_reg_vif_num)
 565		mrt->mroute_reg_vif_num = -1;
 566#endif
 567
 568	if (vifi + 1 == mrt->maxvif) {
 569		int tmp;
 570
 571		for (tmp = vifi - 1; tmp >= 0; tmp--) {
 572			if (VIF_EXISTS(mrt, tmp))
 573				break;
 574		}
 575		mrt->maxvif = tmp+1;
 576	}
 577
 578	write_unlock_bh(&mrt_lock);
 579
 580	dev_set_allmulti(dev, -1);
 581
 582	in_dev = __in_dev_get_rtnl(dev);
 583	if (in_dev) {
 584		IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
 585		ip_rt_multicast_event(in_dev);
 586	}
 587
 588	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
 589		unregister_netdevice_queue(dev, head);
 590
 591	dev_put(dev);
 592	return 0;
 593}
 594
 595static void ipmr_cache_free_rcu(struct rcu_head *head)
 596{
 597	struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
 598
 599	kmem_cache_free(mrt_cachep, c);
 600}
 601
 602static inline void ipmr_cache_free(struct mfc_cache *c)
 603{
 604	call_rcu(&c->rcu, ipmr_cache_free_rcu);
 605}
 606
 607/* Destroy an unresolved cache entry, killing queued skbs
 608 * and reporting error to netlink readers.
 609 */
 610
 611static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
 612{
 613	struct net *net = read_pnet(&mrt->net);
 614	struct sk_buff *skb;
 615	struct nlmsgerr *e;
 616
 617	atomic_dec(&mrt->cache_resolve_queue_len);
 618
 619	while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
 620		if (ip_hdr(skb)->version == 0) {
 621			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
 622			nlh->nlmsg_type = NLMSG_ERROR;
 623			nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
 624			skb_trim(skb, nlh->nlmsg_len);
 625			e = NLMSG_DATA(nlh);
 626			e->error = -ETIMEDOUT;
 627			memset(&e->msg, 0, sizeof(e->msg));
 628
 629			rtnl_unicast(skb, net, NETLINK_CB(skb).pid);
 630		} else {
 631			kfree_skb(skb);
 632		}
 633	}
 634
 635	ipmr_cache_free(c);
 636}
 637
 638
 639/* Timer process for the unresolved queue. */
 640
 641static void ipmr_expire_process(unsigned long arg)
 642{
 643	struct mr_table *mrt = (struct mr_table *)arg;
 644	unsigned long now;
 645	unsigned long expires;
 646	struct mfc_cache *c, *next;
 647
 648	if (!spin_trylock(&mfc_unres_lock)) {
 649		mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
 650		return;
 651	}
 652
 653	if (list_empty(&mrt->mfc_unres_queue))
 654		goto out;
 655
 656	now = jiffies;
 657	expires = 10*HZ;
 658
 659	list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
 660		if (time_after(c->mfc_un.unres.expires, now)) {
 661			unsigned long interval = c->mfc_un.unres.expires - now;
 662			if (interval < expires)
 663				expires = interval;
 664			continue;
 665		}
 666
 667		list_del(&c->list);
 668		ipmr_destroy_unres(mrt, c);
 669	}
 670
 671	if (!list_empty(&mrt->mfc_unres_queue))
 672		mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
 673
 674out:
 675	spin_unlock(&mfc_unres_lock);
 676}
 677
 678/* Fill oifs list. It is called under write locked mrt_lock. */
 679
 680static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
 681				   unsigned char *ttls)
 682{
 683	int vifi;
 684
 685	cache->mfc_un.res.minvif = MAXVIFS;
 686	cache->mfc_un.res.maxvif = 0;
 687	memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
 688
 689	for (vifi = 0; vifi < mrt->maxvif; vifi++) {
 690		if (VIF_EXISTS(mrt, vifi) &&
 691		    ttls[vifi] && ttls[vifi] < 255) {
 692			cache->mfc_un.res.ttls[vifi] = ttls[vifi];
 693			if (cache->mfc_un.res.minvif > vifi)
 694				cache->mfc_un.res.minvif = vifi;
 695			if (cache->mfc_un.res.maxvif <= vifi)
 696				cache->mfc_un.res.maxvif = vifi + 1;
 697		}
 698	}
 699}
 700
 701static int vif_add(struct net *net, struct mr_table *mrt,
 702		   struct vifctl *vifc, int mrtsock)
 703{
 704	int vifi = vifc->vifc_vifi;
 705	struct vif_device *v = &mrt->vif_table[vifi];
 706	struct net_device *dev;
 707	struct in_device *in_dev;
 708	int err;
 709
 710	/* Is vif busy ? */
 711	if (VIF_EXISTS(mrt, vifi))
 712		return -EADDRINUSE;
 713
 714	switch (vifc->vifc_flags) {
 715#ifdef CONFIG_IP_PIMSM
 716	case VIFF_REGISTER:
 717		/*
 718		 * Special Purpose VIF in PIM
 719		 * All the packets will be sent to the daemon
 720		 */
 721		if (mrt->mroute_reg_vif_num >= 0)
 722			return -EADDRINUSE;
 723		dev = ipmr_reg_vif(net, mrt);
 724		if (!dev)
 725			return -ENOBUFS;
 726		err = dev_set_allmulti(dev, 1);
 727		if (err) {
 728			unregister_netdevice(dev);
 729			dev_put(dev);
 730			return err;
 731		}
 732		break;
 733#endif
 734	case VIFF_TUNNEL:
 735		dev = ipmr_new_tunnel(net, vifc);
 736		if (!dev)
 737			return -ENOBUFS;
 738		err = dev_set_allmulti(dev, 1);
 739		if (err) {
 740			ipmr_del_tunnel(dev, vifc);
 741			dev_put(dev);
 742			return err;
 743		}
 744		break;
 745
 746	case VIFF_USE_IFINDEX:
 747	case 0:
 748		if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
 749			dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
 750			if (dev && __in_dev_get_rtnl(dev) == NULL) {
 751				dev_put(dev);
 752				return -EADDRNOTAVAIL;
 753			}
 754		} else {
 755			dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
 756		}
 757		if (!dev)
 758			return -EADDRNOTAVAIL;
 759		err = dev_set_allmulti(dev, 1);
 760		if (err) {
 761			dev_put(dev);
 762			return err;
 763		}
 764		break;
 765	default:
 766		return -EINVAL;
 767	}
 768
 769	in_dev = __in_dev_get_rtnl(dev);
 770	if (!in_dev) {
 771		dev_put(dev);
 772		return -EADDRNOTAVAIL;
 773	}
 774	IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
 775	ip_rt_multicast_event(in_dev);
 776
 777	/* Fill in the VIF structures */
 778
 779	v->rate_limit = vifc->vifc_rate_limit;
 780	v->local = vifc->vifc_lcl_addr.s_addr;
 781	v->remote = vifc->vifc_rmt_addr.s_addr;
 782	v->flags = vifc->vifc_flags;
 783	if (!mrtsock)
 784		v->flags |= VIFF_STATIC;
 785	v->threshold = vifc->vifc_threshold;
 786	v->bytes_in = 0;
 787	v->bytes_out = 0;
 788	v->pkt_in = 0;
 789	v->pkt_out = 0;
 790	v->link = dev->ifindex;
 791	if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
 792		v->link = dev->iflink;
 793
 794	/* And finish update writing critical data */
 795	write_lock_bh(&mrt_lock);
 796	v->dev = dev;
 797#ifdef CONFIG_IP_PIMSM
 798	if (v->flags & VIFF_REGISTER)
 799		mrt->mroute_reg_vif_num = vifi;
 800#endif
 801	if (vifi+1 > mrt->maxvif)
 802		mrt->maxvif = vifi+1;
 803	write_unlock_bh(&mrt_lock);
 804	return 0;
 805}
 806
 807/* called with rcu_read_lock() */
 808static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
 809					 __be32 origin,
 810					 __be32 mcastgrp)
 811{
 812	int line = MFC_HASH(mcastgrp, origin);
 813	struct mfc_cache *c;
 814
 815	list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list) {
 816		if (c->mfc_origin == origin && c->mfc_mcastgrp == mcastgrp)
 817			return c;
 818	}
 819	return NULL;
 820}
 821
 822/*
 823 *	Allocate a multicast cache entry
 824 */
 825static struct mfc_cache *ipmr_cache_alloc(void)
 826{
 827	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
 828
 829	if (c)
 830		c->mfc_un.res.minvif = MAXVIFS;
 831	return c;
 832}
 833
 834static struct mfc_cache *ipmr_cache_alloc_unres(void)
 835{
 836	struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
 837
 838	if (c) {
 839		skb_queue_head_init(&c->mfc_un.unres.unresolved);
 840		c->mfc_un.unres.expires = jiffies + 10*HZ;
 841	}
 842	return c;
 843}
 844
 845/*
 846 *	A cache entry has gone into a resolved state from queued
 847 */
 848
 849static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
 850			       struct mfc_cache *uc, struct mfc_cache *c)
 851{
 852	struct sk_buff *skb;
 853	struct nlmsgerr *e;
 854
 855	/* Play the pending entries through our router */
 856
 857	while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
 858		if (ip_hdr(skb)->version == 0) {
 859			struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
 860
 861			if (__ipmr_fill_mroute(mrt, skb, c, NLMSG_DATA(nlh)) > 0) {
 862				nlh->nlmsg_len = skb_tail_pointer(skb) -
 863						 (u8 *)nlh;
 864			} else {
 865				nlh->nlmsg_type = NLMSG_ERROR;
 866				nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
 867				skb_trim(skb, nlh->nlmsg_len);
 868				e = NLMSG_DATA(nlh);
 869				e->error = -EMSGSIZE;
 870				memset(&e->msg, 0, sizeof(e->msg));
 871			}
 872
 873			rtnl_unicast(skb, net, NETLINK_CB(skb).pid);
 874		} else {
 875			ip_mr_forward(net, mrt, skb, c, 0);
 876		}
 877	}
 878}
 879
 880/*
 881 *	Bounce a cache query up to mrouted. We could use netlink for this but mrouted
 882 *	expects the following bizarre scheme.
 883 *
 884 *	Called under mrt_lock.
 885 */
 886
 887static int ipmr_cache_report(struct mr_table *mrt,
 888			     struct sk_buff *pkt, vifi_t vifi, int assert)
 889{
 890	struct sk_buff *skb;
 891	const int ihl = ip_hdrlen(pkt);
 892	struct igmphdr *igmp;
 893	struct igmpmsg *msg;
 894	struct sock *mroute_sk;
 895	int ret;
 896
 897#ifdef CONFIG_IP_PIMSM
 898	if (assert == IGMPMSG_WHOLEPKT)
 899		skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
 900	else
 901#endif
 902		skb = alloc_skb(128, GFP_ATOMIC);
 903
 904	if (!skb)
 905		return -ENOBUFS;
 906
 907#ifdef CONFIG_IP_PIMSM
 908	if (assert == IGMPMSG_WHOLEPKT) {
 909		/* Ugly, but we have no choice with this interface.
 910		 * Duplicate old header, fix ihl, length etc.
 911		 * And all this only to mangle msg->im_msgtype and
 912		 * to set msg->im_mbz to "mbz" :-)
 913		 */
 914		skb_push(skb, sizeof(struct iphdr));
 915		skb_reset_network_header(skb);
 916		skb_reset_transport_header(skb);
 917		msg = (struct igmpmsg *)skb_network_header(skb);
 918		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
 919		msg->im_msgtype = IGMPMSG_WHOLEPKT;
 920		msg->im_mbz = 0;
 921		msg->im_vif = mrt->mroute_reg_vif_num;
 922		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
 923		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
 924					     sizeof(struct iphdr));
 925	} else
 926#endif
 927	{
 928
 929	/* Copy the IP header */
 930
 931	skb->network_header = skb->tail;
 932	skb_put(skb, ihl);
 933	skb_copy_to_linear_data(skb, pkt->data, ihl);
 934	ip_hdr(skb)->protocol = 0;	/* Flag to the kernel this is a route add */
 935	msg = (struct igmpmsg *)skb_network_header(skb);
 936	msg->im_vif = vifi;
 937	skb_dst_set(skb, dst_clone(skb_dst(pkt)));
 938
 939	/* Add our header */
 940
 941	igmp = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
 942	igmp->type	=
 943	msg->im_msgtype = assert;
 944	igmp->code	= 0;
 945	ip_hdr(skb)->tot_len = htons(skb->len);		/* Fix the length */
 946	skb->transport_header = skb->network_header;
 947	}
 948
 949	rcu_read_lock();
 950	mroute_sk = rcu_dereference(mrt->mroute_sk);
 951	if (mroute_sk == NULL) {
 952		rcu_read_unlock();
 953		kfree_skb(skb);
 954		return -EINVAL;
 955	}
 956
 957	/* Deliver to mrouted */
 958
 959	ret = sock_queue_rcv_skb(mroute_sk, skb);
 960	rcu_read_unlock();
 961	if (ret < 0) {
 962		net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
 
 963		kfree_skb(skb);
 964	}
 965
 966	return ret;
 967}
 968
 969/*
 970 *	Queue a packet for resolution. It gets locked cache entry!
 971 */
 972
 973static int
 974ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi, struct sk_buff *skb)
 975{
 976	bool found = false;
 977	int err;
 978	struct mfc_cache *c;
 979	const struct iphdr *iph = ip_hdr(skb);
 980
 981	spin_lock_bh(&mfc_unres_lock);
 982	list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
 983		if (c->mfc_mcastgrp == iph->daddr &&
 984		    c->mfc_origin == iph->saddr) {
 985			found = true;
 986			break;
 987		}
 988	}
 989
 990	if (!found) {
 991		/* Create a new entry if allowable */
 992
 993		if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
 994		    (c = ipmr_cache_alloc_unres()) == NULL) {
 995			spin_unlock_bh(&mfc_unres_lock);
 996
 997			kfree_skb(skb);
 998			return -ENOBUFS;
 999		}
1000
1001		/* Fill in the new cache entry */
1002
1003		c->mfc_parent	= -1;
1004		c->mfc_origin	= iph->saddr;
1005		c->mfc_mcastgrp	= iph->daddr;
1006
1007		/* Reflect first query at mrouted. */
1008
1009		err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1010		if (err < 0) {
1011			/* If the report failed throw the cache entry
1012			   out - Brad Parker
1013			 */
1014			spin_unlock_bh(&mfc_unres_lock);
1015
1016			ipmr_cache_free(c);
1017			kfree_skb(skb);
1018			return err;
1019		}
1020
1021		atomic_inc(&mrt->cache_resolve_queue_len);
1022		list_add(&c->list, &mrt->mfc_unres_queue);
1023
1024		if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1025			mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1026	}
1027
1028	/* See if we can append the packet */
1029
1030	if (c->mfc_un.unres.unresolved.qlen > 3) {
1031		kfree_skb(skb);
1032		err = -ENOBUFS;
1033	} else {
1034		skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1035		err = 0;
1036	}
1037
1038	spin_unlock_bh(&mfc_unres_lock);
1039	return err;
1040}
1041
1042/*
1043 *	MFC cache manipulation by user space mroute daemon
1044 */
1045
1046static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc)
1047{
1048	int line;
1049	struct mfc_cache *c, *next;
1050
1051	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1052
1053	list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[line], list) {
1054		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1055		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
1056			list_del_rcu(&c->list);
1057
1058			ipmr_cache_free(c);
1059			return 0;
1060		}
1061	}
1062	return -ENOENT;
1063}
1064
1065static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1066			struct mfcctl *mfc, int mrtsock)
1067{
1068	bool found = false;
1069	int line;
1070	struct mfc_cache *uc, *c;
1071
1072	if (mfc->mfcc_parent >= MAXVIFS)
1073		return -ENFILE;
1074
1075	line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1076
1077	list_for_each_entry(c, &mrt->mfc_cache_array[line], list) {
1078		if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1079		    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
1080			found = true;
1081			break;
1082		}
1083	}
1084
1085	if (found) {
1086		write_lock_bh(&mrt_lock);
1087		c->mfc_parent = mfc->mfcc_parent;
1088		ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1089		if (!mrtsock)
1090			c->mfc_flags |= MFC_STATIC;
1091		write_unlock_bh(&mrt_lock);
1092		return 0;
1093	}
1094
1095	if (!ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1096		return -EINVAL;
1097
1098	c = ipmr_cache_alloc();
1099	if (c == NULL)
1100		return -ENOMEM;
1101
1102	c->mfc_origin = mfc->mfcc_origin.s_addr;
1103	c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1104	c->mfc_parent = mfc->mfcc_parent;
1105	ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1106	if (!mrtsock)
1107		c->mfc_flags |= MFC_STATIC;
1108
1109	list_add_rcu(&c->list, &mrt->mfc_cache_array[line]);
1110
1111	/*
1112	 *	Check to see if we resolved a queued list. If so we
1113	 *	need to send on the frames and tidy up.
1114	 */
1115	found = false;
1116	spin_lock_bh(&mfc_unres_lock);
1117	list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1118		if (uc->mfc_origin == c->mfc_origin &&
1119		    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1120			list_del(&uc->list);
1121			atomic_dec(&mrt->cache_resolve_queue_len);
1122			found = true;
1123			break;
1124		}
1125	}
1126	if (list_empty(&mrt->mfc_unres_queue))
1127		del_timer(&mrt->ipmr_expire_timer);
1128	spin_unlock_bh(&mfc_unres_lock);
1129
1130	if (found) {
1131		ipmr_cache_resolve(net, mrt, uc, c);
1132		ipmr_cache_free(uc);
1133	}
1134	return 0;
1135}
1136
1137/*
1138 *	Close the multicast socket, and clear the vif tables etc
1139 */
1140
1141static void mroute_clean_tables(struct mr_table *mrt)
1142{
1143	int i;
1144	LIST_HEAD(list);
1145	struct mfc_cache *c, *next;
1146
1147	/* Shut down all active vif entries */
1148
1149	for (i = 0; i < mrt->maxvif; i++) {
1150		if (!(mrt->vif_table[i].flags & VIFF_STATIC))
1151			vif_delete(mrt, i, 0, &list);
1152	}
1153	unregister_netdevice_many(&list);
1154
1155	/* Wipe the cache */
1156
1157	for (i = 0; i < MFC_LINES; i++) {
1158		list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[i], list) {
1159			if (c->mfc_flags & MFC_STATIC)
1160				continue;
1161			list_del_rcu(&c->list);
1162			ipmr_cache_free(c);
1163		}
1164	}
1165
1166	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1167		spin_lock_bh(&mfc_unres_lock);
1168		list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
1169			list_del(&c->list);
1170			ipmr_destroy_unres(mrt, c);
1171		}
1172		spin_unlock_bh(&mfc_unres_lock);
1173	}
1174}
1175
1176/* called from ip_ra_control(), before an RCU grace period,
1177 * we dont need to call synchronize_rcu() here
1178 */
1179static void mrtsock_destruct(struct sock *sk)
1180{
1181	struct net *net = sock_net(sk);
1182	struct mr_table *mrt;
1183
1184	rtnl_lock();
1185	ipmr_for_each_table(mrt, net) {
1186		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1187			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1188			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1189			mroute_clean_tables(mrt);
1190		}
1191	}
1192	rtnl_unlock();
1193}
1194
1195/*
1196 *	Socket options and virtual interface manipulation. The whole
1197 *	virtual interface system is a complete heap, but unfortunately
1198 *	that's how BSD mrouted happens to think. Maybe one day with a proper
1199 *	MOSPF/PIM router set up we can clean this up.
1200 */
1201
1202int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen)
1203{
1204	int ret;
1205	struct vifctl vif;
1206	struct mfcctl mfc;
1207	struct net *net = sock_net(sk);
1208	struct mr_table *mrt;
1209
1210	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1211	if (mrt == NULL)
1212		return -ENOENT;
1213
1214	if (optname != MRT_INIT) {
1215		if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1216		    !capable(CAP_NET_ADMIN))
1217			return -EACCES;
1218	}
1219
1220	switch (optname) {
1221	case MRT_INIT:
1222		if (sk->sk_type != SOCK_RAW ||
1223		    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1224			return -EOPNOTSUPP;
1225		if (optlen != sizeof(int))
1226			return -ENOPROTOOPT;
1227
1228		rtnl_lock();
1229		if (rtnl_dereference(mrt->mroute_sk)) {
1230			rtnl_unlock();
1231			return -EADDRINUSE;
1232		}
1233
1234		ret = ip_ra_control(sk, 1, mrtsock_destruct);
1235		if (ret == 0) {
1236			rcu_assign_pointer(mrt->mroute_sk, sk);
1237			IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1238		}
1239		rtnl_unlock();
1240		return ret;
1241	case MRT_DONE:
1242		if (sk != rcu_access_pointer(mrt->mroute_sk))
1243			return -EACCES;
1244		return ip_ra_control(sk, 0, NULL);
1245	case MRT_ADD_VIF:
1246	case MRT_DEL_VIF:
1247		if (optlen != sizeof(vif))
1248			return -EINVAL;
1249		if (copy_from_user(&vif, optval, sizeof(vif)))
1250			return -EFAULT;
1251		if (vif.vifc_vifi >= MAXVIFS)
1252			return -ENFILE;
1253		rtnl_lock();
1254		if (optname == MRT_ADD_VIF) {
1255			ret = vif_add(net, mrt, &vif,
1256				      sk == rtnl_dereference(mrt->mroute_sk));
1257		} else {
1258			ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1259		}
1260		rtnl_unlock();
1261		return ret;
1262
1263		/*
1264		 *	Manipulate the forwarding caches. These live
1265		 *	in a sort of kernel/user symbiosis.
1266		 */
1267	case MRT_ADD_MFC:
1268	case MRT_DEL_MFC:
1269		if (optlen != sizeof(mfc))
1270			return -EINVAL;
1271		if (copy_from_user(&mfc, optval, sizeof(mfc)))
1272			return -EFAULT;
1273		rtnl_lock();
1274		if (optname == MRT_DEL_MFC)
1275			ret = ipmr_mfc_delete(mrt, &mfc);
1276		else
1277			ret = ipmr_mfc_add(net, mrt, &mfc,
1278					   sk == rtnl_dereference(mrt->mroute_sk));
1279		rtnl_unlock();
1280		return ret;
1281		/*
1282		 *	Control PIM assert.
1283		 */
1284	case MRT_ASSERT:
1285	{
1286		int v;
1287		if (get_user(v, (int __user *)optval))
1288			return -EFAULT;
1289		mrt->mroute_do_assert = (v) ? 1 : 0;
1290		return 0;
1291	}
1292#ifdef CONFIG_IP_PIMSM
1293	case MRT_PIM:
1294	{
1295		int v;
1296
1297		if (get_user(v, (int __user *)optval))
1298			return -EFAULT;
1299		v = (v) ? 1 : 0;
1300
1301		rtnl_lock();
1302		ret = 0;
1303		if (v != mrt->mroute_do_pim) {
1304			mrt->mroute_do_pim = v;
1305			mrt->mroute_do_assert = v;
1306		}
1307		rtnl_unlock();
1308		return ret;
1309	}
1310#endif
1311#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
1312	case MRT_TABLE:
1313	{
1314		u32 v;
1315
1316		if (optlen != sizeof(u32))
1317			return -EINVAL;
1318		if (get_user(v, (u32 __user *)optval))
1319			return -EFAULT;
1320
1321		rtnl_lock();
1322		ret = 0;
1323		if (sk == rtnl_dereference(mrt->mroute_sk)) {
1324			ret = -EBUSY;
1325		} else {
1326			if (!ipmr_new_table(net, v))
1327				ret = -ENOMEM;
1328			raw_sk(sk)->ipmr_table = v;
1329		}
1330		rtnl_unlock();
1331		return ret;
1332	}
1333#endif
1334	/*
1335	 *	Spurious command, or MRT_VERSION which you cannot
1336	 *	set.
1337	 */
1338	default:
1339		return -ENOPROTOOPT;
1340	}
1341}
1342
1343/*
1344 *	Getsock opt support for the multicast routing system.
1345 */
1346
1347int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1348{
1349	int olr;
1350	int val;
1351	struct net *net = sock_net(sk);
1352	struct mr_table *mrt;
1353
1354	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1355	if (mrt == NULL)
1356		return -ENOENT;
1357
1358	if (optname != MRT_VERSION &&
1359#ifdef CONFIG_IP_PIMSM
1360	   optname != MRT_PIM &&
1361#endif
1362	   optname != MRT_ASSERT)
1363		return -ENOPROTOOPT;
1364
1365	if (get_user(olr, optlen))
1366		return -EFAULT;
1367
1368	olr = min_t(unsigned int, olr, sizeof(int));
1369	if (olr < 0)
1370		return -EINVAL;
1371
1372	if (put_user(olr, optlen))
1373		return -EFAULT;
1374	if (optname == MRT_VERSION)
1375		val = 0x0305;
1376#ifdef CONFIG_IP_PIMSM
1377	else if (optname == MRT_PIM)
1378		val = mrt->mroute_do_pim;
1379#endif
1380	else
1381		val = mrt->mroute_do_assert;
1382	if (copy_to_user(optval, &val, olr))
1383		return -EFAULT;
1384	return 0;
1385}
1386
1387/*
1388 *	The IP multicast ioctl support routines.
1389 */
1390
1391int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1392{
1393	struct sioc_sg_req sr;
1394	struct sioc_vif_req vr;
1395	struct vif_device *vif;
1396	struct mfc_cache *c;
1397	struct net *net = sock_net(sk);
1398	struct mr_table *mrt;
1399
1400	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1401	if (mrt == NULL)
1402		return -ENOENT;
1403
1404	switch (cmd) {
1405	case SIOCGETVIFCNT:
1406		if (copy_from_user(&vr, arg, sizeof(vr)))
1407			return -EFAULT;
1408		if (vr.vifi >= mrt->maxvif)
1409			return -EINVAL;
1410		read_lock(&mrt_lock);
1411		vif = &mrt->vif_table[vr.vifi];
1412		if (VIF_EXISTS(mrt, vr.vifi)) {
1413			vr.icount = vif->pkt_in;
1414			vr.ocount = vif->pkt_out;
1415			vr.ibytes = vif->bytes_in;
1416			vr.obytes = vif->bytes_out;
1417			read_unlock(&mrt_lock);
1418
1419			if (copy_to_user(arg, &vr, sizeof(vr)))
1420				return -EFAULT;
1421			return 0;
1422		}
1423		read_unlock(&mrt_lock);
1424		return -EADDRNOTAVAIL;
1425	case SIOCGETSGCNT:
1426		if (copy_from_user(&sr, arg, sizeof(sr)))
1427			return -EFAULT;
1428
1429		rcu_read_lock();
1430		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1431		if (c) {
1432			sr.pktcnt = c->mfc_un.res.pkt;
1433			sr.bytecnt = c->mfc_un.res.bytes;
1434			sr.wrong_if = c->mfc_un.res.wrong_if;
1435			rcu_read_unlock();
1436
1437			if (copy_to_user(arg, &sr, sizeof(sr)))
1438				return -EFAULT;
1439			return 0;
1440		}
1441		rcu_read_unlock();
1442		return -EADDRNOTAVAIL;
1443	default:
1444		return -ENOIOCTLCMD;
1445	}
1446}
1447
1448#ifdef CONFIG_COMPAT
1449struct compat_sioc_sg_req {
1450	struct in_addr src;
1451	struct in_addr grp;
1452	compat_ulong_t pktcnt;
1453	compat_ulong_t bytecnt;
1454	compat_ulong_t wrong_if;
1455};
1456
1457struct compat_sioc_vif_req {
1458	vifi_t	vifi;		/* Which iface */
1459	compat_ulong_t icount;
1460	compat_ulong_t ocount;
1461	compat_ulong_t ibytes;
1462	compat_ulong_t obytes;
1463};
1464
1465int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1466{
1467	struct compat_sioc_sg_req sr;
1468	struct compat_sioc_vif_req vr;
1469	struct vif_device *vif;
1470	struct mfc_cache *c;
1471	struct net *net = sock_net(sk);
1472	struct mr_table *mrt;
1473
1474	mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1475	if (mrt == NULL)
1476		return -ENOENT;
1477
1478	switch (cmd) {
1479	case SIOCGETVIFCNT:
1480		if (copy_from_user(&vr, arg, sizeof(vr)))
1481			return -EFAULT;
1482		if (vr.vifi >= mrt->maxvif)
1483			return -EINVAL;
1484		read_lock(&mrt_lock);
1485		vif = &mrt->vif_table[vr.vifi];
1486		if (VIF_EXISTS(mrt, vr.vifi)) {
1487			vr.icount = vif->pkt_in;
1488			vr.ocount = vif->pkt_out;
1489			vr.ibytes = vif->bytes_in;
1490			vr.obytes = vif->bytes_out;
1491			read_unlock(&mrt_lock);
1492
1493			if (copy_to_user(arg, &vr, sizeof(vr)))
1494				return -EFAULT;
1495			return 0;
1496		}
1497		read_unlock(&mrt_lock);
1498		return -EADDRNOTAVAIL;
1499	case SIOCGETSGCNT:
1500		if (copy_from_user(&sr, arg, sizeof(sr)))
1501			return -EFAULT;
1502
1503		rcu_read_lock();
1504		c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1505		if (c) {
1506			sr.pktcnt = c->mfc_un.res.pkt;
1507			sr.bytecnt = c->mfc_un.res.bytes;
1508			sr.wrong_if = c->mfc_un.res.wrong_if;
1509			rcu_read_unlock();
1510
1511			if (copy_to_user(arg, &sr, sizeof(sr)))
1512				return -EFAULT;
1513			return 0;
1514		}
1515		rcu_read_unlock();
1516		return -EADDRNOTAVAIL;
1517	default:
1518		return -ENOIOCTLCMD;
1519	}
1520}
1521#endif
1522
1523
1524static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1525{
1526	struct net_device *dev = ptr;
1527	struct net *net = dev_net(dev);
1528	struct mr_table *mrt;
1529	struct vif_device *v;
1530	int ct;
 
1531
1532	if (event != NETDEV_UNREGISTER)
1533		return NOTIFY_DONE;
1534
1535	ipmr_for_each_table(mrt, net) {
1536		v = &mrt->vif_table[0];
1537		for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1538			if (v->dev == dev)
1539				vif_delete(mrt, ct, 1, NULL);
1540		}
1541	}
 
1542	return NOTIFY_DONE;
1543}
1544
1545
1546static struct notifier_block ip_mr_notifier = {
1547	.notifier_call = ipmr_device_event,
1548};
1549
1550/*
1551 *	Encapsulate a packet by attaching a valid IPIP header to it.
1552 *	This avoids tunnel drivers and other mess and gives us the speed so
1553 *	important for multicast video.
1554 */
1555
1556static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr)
1557{
1558	struct iphdr *iph;
1559	const struct iphdr *old_iph = ip_hdr(skb);
1560
1561	skb_push(skb, sizeof(struct iphdr));
1562	skb->transport_header = skb->network_header;
1563	skb_reset_network_header(skb);
1564	iph = ip_hdr(skb);
1565
1566	iph->version	=	4;
1567	iph->tos	=	old_iph->tos;
1568	iph->ttl	=	old_iph->ttl;
1569	iph->frag_off	=	0;
1570	iph->daddr	=	daddr;
1571	iph->saddr	=	saddr;
1572	iph->protocol	=	IPPROTO_IPIP;
1573	iph->ihl	=	5;
1574	iph->tot_len	=	htons(skb->len);
1575	ip_select_ident(iph, skb_dst(skb), NULL);
1576	ip_send_check(iph);
1577
1578	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1579	nf_reset(skb);
1580}
1581
1582static inline int ipmr_forward_finish(struct sk_buff *skb)
1583{
1584	struct ip_options *opt = &(IPCB(skb)->opt);
1585
1586	IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
1587	IP_ADD_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTOCTETS, skb->len);
1588
1589	if (unlikely(opt->optlen))
1590		ip_forward_options(skb);
1591
1592	return dst_output(skb);
1593}
1594
1595/*
1596 *	Processing handlers for ipmr_forward
1597 */
1598
1599static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1600			    struct sk_buff *skb, struct mfc_cache *c, int vifi)
1601{
1602	const struct iphdr *iph = ip_hdr(skb);
1603	struct vif_device *vif = &mrt->vif_table[vifi];
1604	struct net_device *dev;
1605	struct rtable *rt;
1606	struct flowi4 fl4;
1607	int    encap = 0;
1608
1609	if (vif->dev == NULL)
1610		goto out_free;
1611
1612#ifdef CONFIG_IP_PIMSM
1613	if (vif->flags & VIFF_REGISTER) {
1614		vif->pkt_out++;
1615		vif->bytes_out += skb->len;
1616		vif->dev->stats.tx_bytes += skb->len;
1617		vif->dev->stats.tx_packets++;
1618		ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1619		goto out_free;
1620	}
1621#endif
1622
1623	if (vif->flags & VIFF_TUNNEL) {
1624		rt = ip_route_output_ports(net, &fl4, NULL,
1625					   vif->remote, vif->local,
1626					   0, 0,
1627					   IPPROTO_IPIP,
1628					   RT_TOS(iph->tos), vif->link);
1629		if (IS_ERR(rt))
1630			goto out_free;
1631		encap = sizeof(struct iphdr);
1632	} else {
1633		rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1634					   0, 0,
1635					   IPPROTO_IPIP,
1636					   RT_TOS(iph->tos), vif->link);
1637		if (IS_ERR(rt))
1638			goto out_free;
1639	}
1640
1641	dev = rt->dst.dev;
1642
1643	if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1644		/* Do not fragment multicasts. Alas, IPv4 does not
1645		 * allow to send ICMP, so that packets will disappear
1646		 * to blackhole.
1647		 */
1648
1649		IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
1650		ip_rt_put(rt);
1651		goto out_free;
1652	}
1653
1654	encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1655
1656	if (skb_cow(skb, encap)) {
1657		ip_rt_put(rt);
1658		goto out_free;
1659	}
1660
1661	vif->pkt_out++;
1662	vif->bytes_out += skb->len;
1663
1664	skb_dst_drop(skb);
1665	skb_dst_set(skb, &rt->dst);
1666	ip_decrease_ttl(ip_hdr(skb));
1667
1668	/* FIXME: forward and output firewalls used to be called here.
1669	 * What do we do with netfilter? -- RR
1670	 */
1671	if (vif->flags & VIFF_TUNNEL) {
1672		ip_encap(skb, vif->local, vif->remote);
1673		/* FIXME: extra output firewall step used to be here. --RR */
1674		vif->dev->stats.tx_packets++;
1675		vif->dev->stats.tx_bytes += skb->len;
1676	}
1677
1678	IPCB(skb)->flags |= IPSKB_FORWARDED;
1679
1680	/*
1681	 * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1682	 * not only before forwarding, but after forwarding on all output
1683	 * interfaces. It is clear, if mrouter runs a multicasting
1684	 * program, it should receive packets not depending to what interface
1685	 * program is joined.
1686	 * If we will not make it, the program will have to join on all
1687	 * interfaces. On the other hand, multihoming host (or router, but
1688	 * not mrouter) cannot join to more than one interface - it will
1689	 * result in receiving multiple packets.
1690	 */
1691	NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, skb, skb->dev, dev,
1692		ipmr_forward_finish);
1693	return;
1694
1695out_free:
1696	kfree_skb(skb);
1697}
1698
1699static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1700{
1701	int ct;
1702
1703	for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1704		if (mrt->vif_table[ct].dev == dev)
1705			break;
1706	}
1707	return ct;
1708}
1709
1710/* "local" means that we should preserve one skb (for local delivery) */
1711
1712static int ip_mr_forward(struct net *net, struct mr_table *mrt,
1713			 struct sk_buff *skb, struct mfc_cache *cache,
1714			 int local)
1715{
1716	int psend = -1;
1717	int vif, ct;
1718
1719	vif = cache->mfc_parent;
1720	cache->mfc_un.res.pkt++;
1721	cache->mfc_un.res.bytes += skb->len;
1722
1723	/*
1724	 * Wrong interface: drop packet and (maybe) send PIM assert.
1725	 */
1726	if (mrt->vif_table[vif].dev != skb->dev) {
1727		int true_vifi;
1728
1729		if (rt_is_output_route(skb_rtable(skb))) {
1730			/* It is our own packet, looped back.
1731			 * Very complicated situation...
1732			 *
1733			 * The best workaround until routing daemons will be
1734			 * fixed is not to redistribute packet, if it was
1735			 * send through wrong interface. It means, that
1736			 * multicast applications WILL NOT work for
1737			 * (S,G), which have default multicast route pointing
1738			 * to wrong oif. In any case, it is not a good
1739			 * idea to use multicasting applications on router.
1740			 */
1741			goto dont_forward;
1742		}
1743
1744		cache->mfc_un.res.wrong_if++;
1745		true_vifi = ipmr_find_vif(mrt, skb->dev);
1746
1747		if (true_vifi >= 0 && mrt->mroute_do_assert &&
1748		    /* pimsm uses asserts, when switching from RPT to SPT,
1749		     * so that we cannot check that packet arrived on an oif.
1750		     * It is bad, but otherwise we would need to move pretty
1751		     * large chunk of pimd to kernel. Ough... --ANK
1752		     */
1753		    (mrt->mroute_do_pim ||
1754		     cache->mfc_un.res.ttls[true_vifi] < 255) &&
1755		    time_after(jiffies,
1756			       cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1757			cache->mfc_un.res.last_assert = jiffies;
1758			ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1759		}
1760		goto dont_forward;
1761	}
1762
1763	mrt->vif_table[vif].pkt_in++;
1764	mrt->vif_table[vif].bytes_in += skb->len;
1765
1766	/*
1767	 *	Forward the frame
1768	 */
1769	for (ct = cache->mfc_un.res.maxvif - 1;
1770	     ct >= cache->mfc_un.res.minvif; ct--) {
1771		if (ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1772			if (psend != -1) {
1773				struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1774
1775				if (skb2)
1776					ipmr_queue_xmit(net, mrt, skb2, cache,
1777							psend);
1778			}
1779			psend = ct;
1780		}
1781	}
1782	if (psend != -1) {
1783		if (local) {
1784			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1785
1786			if (skb2)
1787				ipmr_queue_xmit(net, mrt, skb2, cache, psend);
1788		} else {
1789			ipmr_queue_xmit(net, mrt, skb, cache, psend);
1790			return 0;
1791		}
1792	}
1793
1794dont_forward:
1795	if (!local)
1796		kfree_skb(skb);
1797	return 0;
1798}
1799
1800static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
1801{
1802	struct rtable *rt = skb_rtable(skb);
1803	struct iphdr *iph = ip_hdr(skb);
1804	struct flowi4 fl4 = {
1805		.daddr = iph->daddr,
1806		.saddr = iph->saddr,
1807		.flowi4_tos = RT_TOS(iph->tos),
1808		.flowi4_oif = rt->rt_oif,
1809		.flowi4_iif = rt->rt_iif,
1810		.flowi4_mark = rt->rt_mark,
1811	};
1812	struct mr_table *mrt;
1813	int err;
1814
1815	err = ipmr_fib_lookup(net, &fl4, &mrt);
1816	if (err)
1817		return ERR_PTR(err);
1818	return mrt;
1819}
1820
1821/*
1822 *	Multicast packets for forwarding arrive here
1823 *	Called with rcu_read_lock();
1824 */
1825
1826int ip_mr_input(struct sk_buff *skb)
1827{
1828	struct mfc_cache *cache;
1829	struct net *net = dev_net(skb->dev);
1830	int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
1831	struct mr_table *mrt;
1832
1833	/* Packet is looped back after forward, it should not be
1834	 * forwarded second time, but still can be delivered locally.
1835	 */
1836	if (IPCB(skb)->flags & IPSKB_FORWARDED)
1837		goto dont_forward;
1838
1839	mrt = ipmr_rt_fib_lookup(net, skb);
1840	if (IS_ERR(mrt)) {
1841		kfree_skb(skb);
1842		return PTR_ERR(mrt);
1843	}
1844	if (!local) {
1845		if (IPCB(skb)->opt.router_alert) {
1846			if (ip_call_ra_chain(skb))
1847				return 0;
1848		} else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
1849			/* IGMPv1 (and broken IGMPv2 implementations sort of
1850			 * Cisco IOS <= 11.2(8)) do not put router alert
1851			 * option to IGMP packets destined to routable
1852			 * groups. It is very bad, because it means
1853			 * that we can forward NO IGMP messages.
1854			 */
1855			struct sock *mroute_sk;
1856
1857			mroute_sk = rcu_dereference(mrt->mroute_sk);
1858			if (mroute_sk) {
1859				nf_reset(skb);
1860				raw_rcv(mroute_sk, skb);
1861				return 0;
1862			}
1863		    }
1864	}
1865
1866	/* already under rcu_read_lock() */
1867	cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
1868
1869	/*
1870	 *	No usable cache entry
1871	 */
1872	if (cache == NULL) {
1873		int vif;
1874
1875		if (local) {
1876			struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1877			ip_local_deliver(skb);
1878			if (skb2 == NULL)
1879				return -ENOBUFS;
1880			skb = skb2;
1881		}
1882
1883		read_lock(&mrt_lock);
1884		vif = ipmr_find_vif(mrt, skb->dev);
1885		if (vif >= 0) {
1886			int err2 = ipmr_cache_unresolved(mrt, vif, skb);
1887			read_unlock(&mrt_lock);
1888
1889			return err2;
1890		}
1891		read_unlock(&mrt_lock);
1892		kfree_skb(skb);
1893		return -ENODEV;
1894	}
1895
1896	read_lock(&mrt_lock);
1897	ip_mr_forward(net, mrt, skb, cache, local);
1898	read_unlock(&mrt_lock);
1899
1900	if (local)
1901		return ip_local_deliver(skb);
1902
1903	return 0;
1904
1905dont_forward:
1906	if (local)
1907		return ip_local_deliver(skb);
1908	kfree_skb(skb);
1909	return 0;
1910}
1911
1912#ifdef CONFIG_IP_PIMSM
1913/* called with rcu_read_lock() */
1914static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
1915		     unsigned int pimlen)
1916{
1917	struct net_device *reg_dev = NULL;
1918	struct iphdr *encap;
1919
1920	encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
1921	/*
1922	 * Check that:
1923	 * a. packet is really sent to a multicast group
1924	 * b. packet is not a NULL-REGISTER
1925	 * c. packet is not truncated
1926	 */
1927	if (!ipv4_is_multicast(encap->daddr) ||
1928	    encap->tot_len == 0 ||
1929	    ntohs(encap->tot_len) + pimlen > skb->len)
1930		return 1;
1931
1932	read_lock(&mrt_lock);
1933	if (mrt->mroute_reg_vif_num >= 0)
1934		reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
1935	read_unlock(&mrt_lock);
1936
1937	if (reg_dev == NULL)
1938		return 1;
1939
1940	skb->mac_header = skb->network_header;
1941	skb_pull(skb, (u8 *)encap - skb->data);
1942	skb_reset_network_header(skb);
1943	skb->protocol = htons(ETH_P_IP);
1944	skb->ip_summed = CHECKSUM_NONE;
1945	skb->pkt_type = PACKET_HOST;
1946
1947	skb_tunnel_rx(skb, reg_dev);
1948
1949	netif_rx(skb);
1950
1951	return NET_RX_SUCCESS;
1952}
1953#endif
1954
1955#ifdef CONFIG_IP_PIMSM_V1
1956/*
1957 * Handle IGMP messages of PIMv1
1958 */
1959
1960int pim_rcv_v1(struct sk_buff *skb)
1961{
1962	struct igmphdr *pim;
1963	struct net *net = dev_net(skb->dev);
1964	struct mr_table *mrt;
1965
1966	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
1967		goto drop;
1968
1969	pim = igmp_hdr(skb);
1970
1971	mrt = ipmr_rt_fib_lookup(net, skb);
1972	if (IS_ERR(mrt))
1973		goto drop;
1974	if (!mrt->mroute_do_pim ||
1975	    pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
1976		goto drop;
1977
1978	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
1979drop:
1980		kfree_skb(skb);
1981	}
1982	return 0;
1983}
1984#endif
1985
1986#ifdef CONFIG_IP_PIMSM_V2
1987static int pim_rcv(struct sk_buff *skb)
1988{
1989	struct pimreghdr *pim;
1990	struct net *net = dev_net(skb->dev);
1991	struct mr_table *mrt;
1992
1993	if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
1994		goto drop;
1995
1996	pim = (struct pimreghdr *)skb_transport_header(skb);
1997	if (pim->type != ((PIM_VERSION << 4) | (PIM_REGISTER)) ||
1998	    (pim->flags & PIM_NULL_REGISTER) ||
1999	    (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2000	     csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2001		goto drop;
2002
2003	mrt = ipmr_rt_fib_lookup(net, skb);
2004	if (IS_ERR(mrt))
2005		goto drop;
2006	if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2007drop:
2008		kfree_skb(skb);
2009	}
2010	return 0;
2011}
2012#endif
2013
2014static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2015			      struct mfc_cache *c, struct rtmsg *rtm)
2016{
2017	int ct;
2018	struct rtnexthop *nhp;
2019	u8 *b = skb_tail_pointer(skb);
2020	struct rtattr *mp_head;
2021
2022	/* If cache is unresolved, don't try to parse IIF and OIF */
2023	if (c->mfc_parent >= MAXVIFS)
2024		return -ENOENT;
2025
2026	if (VIF_EXISTS(mrt, c->mfc_parent))
2027		RTA_PUT(skb, RTA_IIF, 4, &mrt->vif_table[c->mfc_parent].dev->ifindex);
2028
2029	mp_head = (struct rtattr *)skb_put(skb, RTA_LENGTH(0));
2030
2031	for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
2032		if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
2033			if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
2034				goto rtattr_failure;
2035			nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
2036			nhp->rtnh_flags = 0;
2037			nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
2038			nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
2039			nhp->rtnh_len = sizeof(*nhp);
2040		}
2041	}
2042	mp_head->rta_type = RTA_MULTIPATH;
2043	mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head;
2044	rtm->rtm_type = RTN_MULTICAST;
2045	return 1;
2046
2047rtattr_failure:
2048	nlmsg_trim(skb, b);
2049	return -EMSGSIZE;
2050}
2051
2052int ipmr_get_route(struct net *net, struct sk_buff *skb,
2053		   __be32 saddr, __be32 daddr,
2054		   struct rtmsg *rtm, int nowait)
2055{
2056	struct mfc_cache *cache;
2057	struct mr_table *mrt;
2058	int err;
2059
2060	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2061	if (mrt == NULL)
2062		return -ENOENT;
2063
2064	rcu_read_lock();
2065	cache = ipmr_cache_find(mrt, saddr, daddr);
2066
2067	if (cache == NULL) {
2068		struct sk_buff *skb2;
2069		struct iphdr *iph;
2070		struct net_device *dev;
2071		int vif = -1;
2072
2073		if (nowait) {
2074			rcu_read_unlock();
2075			return -EAGAIN;
2076		}
2077
2078		dev = skb->dev;
2079		read_lock(&mrt_lock);
2080		if (dev)
2081			vif = ipmr_find_vif(mrt, dev);
2082		if (vif < 0) {
2083			read_unlock(&mrt_lock);
2084			rcu_read_unlock();
2085			return -ENODEV;
2086		}
2087		skb2 = skb_clone(skb, GFP_ATOMIC);
2088		if (!skb2) {
2089			read_unlock(&mrt_lock);
2090			rcu_read_unlock();
2091			return -ENOMEM;
2092		}
2093
2094		skb_push(skb2, sizeof(struct iphdr));
2095		skb_reset_network_header(skb2);
2096		iph = ip_hdr(skb2);
2097		iph->ihl = sizeof(struct iphdr) >> 2;
2098		iph->saddr = saddr;
2099		iph->daddr = daddr;
2100		iph->version = 0;
2101		err = ipmr_cache_unresolved(mrt, vif, skb2);
2102		read_unlock(&mrt_lock);
2103		rcu_read_unlock();
2104		return err;
2105	}
2106
2107	read_lock(&mrt_lock);
2108	if (!nowait && (rtm->rtm_flags & RTM_F_NOTIFY))
2109		cache->mfc_flags |= MFC_NOTIFY;
2110	err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2111	read_unlock(&mrt_lock);
2112	rcu_read_unlock();
2113	return err;
2114}
2115
2116static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2117			    u32 pid, u32 seq, struct mfc_cache *c)
2118{
2119	struct nlmsghdr *nlh;
2120	struct rtmsg *rtm;
2121
2122	nlh = nlmsg_put(skb, pid, seq, RTM_NEWROUTE, sizeof(*rtm), NLM_F_MULTI);
2123	if (nlh == NULL)
2124		return -EMSGSIZE;
2125
2126	rtm = nlmsg_data(nlh);
2127	rtm->rtm_family   = RTNL_FAMILY_IPMR;
2128	rtm->rtm_dst_len  = 32;
2129	rtm->rtm_src_len  = 32;
2130	rtm->rtm_tos      = 0;
2131	rtm->rtm_table    = mrt->id;
2132	if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2133		goto nla_put_failure;
2134	rtm->rtm_type     = RTN_MULTICAST;
2135	rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2136	rtm->rtm_protocol = RTPROT_UNSPEC;
2137	rtm->rtm_flags    = 0;
2138
2139	if (nla_put_be32(skb, RTA_SRC, c->mfc_origin) ||
2140	    nla_put_be32(skb, RTA_DST, c->mfc_mcastgrp))
2141		goto nla_put_failure;
2142	if (__ipmr_fill_mroute(mrt, skb, c, rtm) < 0)
2143		goto nla_put_failure;
2144
2145	return nlmsg_end(skb, nlh);
2146
2147nla_put_failure:
2148	nlmsg_cancel(skb, nlh);
2149	return -EMSGSIZE;
2150}
2151
2152static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2153{
2154	struct net *net = sock_net(skb->sk);
2155	struct mr_table *mrt;
2156	struct mfc_cache *mfc;
2157	unsigned int t = 0, s_t;
2158	unsigned int h = 0, s_h;
2159	unsigned int e = 0, s_e;
2160
2161	s_t = cb->args[0];
2162	s_h = cb->args[1];
2163	s_e = cb->args[2];
2164
2165	rcu_read_lock();
2166	ipmr_for_each_table(mrt, net) {
2167		if (t < s_t)
2168			goto next_table;
2169		if (t > s_t)
2170			s_h = 0;
2171		for (h = s_h; h < MFC_LINES; h++) {
2172			list_for_each_entry_rcu(mfc, &mrt->mfc_cache_array[h], list) {
2173				if (e < s_e)
2174					goto next_entry;
2175				if (ipmr_fill_mroute(mrt, skb,
2176						     NETLINK_CB(cb->skb).pid,
2177						     cb->nlh->nlmsg_seq,
2178						     mfc) < 0)
2179					goto done;
2180next_entry:
2181				e++;
2182			}
2183			e = s_e = 0;
2184		}
2185		s_h = 0;
2186next_table:
2187		t++;
2188	}
2189done:
2190	rcu_read_unlock();
2191
2192	cb->args[2] = e;
2193	cb->args[1] = h;
2194	cb->args[0] = t;
2195
2196	return skb->len;
2197}
2198
2199#ifdef CONFIG_PROC_FS
2200/*
2201 *	The /proc interfaces to multicast routing :
2202 *	/proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2203 */
2204struct ipmr_vif_iter {
2205	struct seq_net_private p;
2206	struct mr_table *mrt;
2207	int ct;
2208};
2209
2210static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2211					   struct ipmr_vif_iter *iter,
2212					   loff_t pos)
2213{
2214	struct mr_table *mrt = iter->mrt;
2215
2216	for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2217		if (!VIF_EXISTS(mrt, iter->ct))
2218			continue;
2219		if (pos-- == 0)
2220			return &mrt->vif_table[iter->ct];
2221	}
2222	return NULL;
2223}
2224
2225static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2226	__acquires(mrt_lock)
2227{
2228	struct ipmr_vif_iter *iter = seq->private;
2229	struct net *net = seq_file_net(seq);
2230	struct mr_table *mrt;
2231
2232	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2233	if (mrt == NULL)
2234		return ERR_PTR(-ENOENT);
2235
2236	iter->mrt = mrt;
2237
2238	read_lock(&mrt_lock);
2239	return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2240		: SEQ_START_TOKEN;
2241}
2242
2243static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2244{
2245	struct ipmr_vif_iter *iter = seq->private;
2246	struct net *net = seq_file_net(seq);
2247	struct mr_table *mrt = iter->mrt;
2248
2249	++*pos;
2250	if (v == SEQ_START_TOKEN)
2251		return ipmr_vif_seq_idx(net, iter, 0);
2252
2253	while (++iter->ct < mrt->maxvif) {
2254		if (!VIF_EXISTS(mrt, iter->ct))
2255			continue;
2256		return &mrt->vif_table[iter->ct];
2257	}
2258	return NULL;
2259}
2260
2261static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2262	__releases(mrt_lock)
2263{
2264	read_unlock(&mrt_lock);
2265}
2266
2267static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2268{
2269	struct ipmr_vif_iter *iter = seq->private;
2270	struct mr_table *mrt = iter->mrt;
2271
2272	if (v == SEQ_START_TOKEN) {
2273		seq_puts(seq,
2274			 "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2275	} else {
2276		const struct vif_device *vif = v;
2277		const char *name =  vif->dev ? vif->dev->name : "none";
2278
2279		seq_printf(seq,
2280			   "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2281			   vif - mrt->vif_table,
2282			   name, vif->bytes_in, vif->pkt_in,
2283			   vif->bytes_out, vif->pkt_out,
2284			   vif->flags, vif->local, vif->remote);
2285	}
2286	return 0;
2287}
2288
2289static const struct seq_operations ipmr_vif_seq_ops = {
2290	.start = ipmr_vif_seq_start,
2291	.next  = ipmr_vif_seq_next,
2292	.stop  = ipmr_vif_seq_stop,
2293	.show  = ipmr_vif_seq_show,
2294};
2295
2296static int ipmr_vif_open(struct inode *inode, struct file *file)
2297{
2298	return seq_open_net(inode, file, &ipmr_vif_seq_ops,
2299			    sizeof(struct ipmr_vif_iter));
2300}
2301
2302static const struct file_operations ipmr_vif_fops = {
2303	.owner	 = THIS_MODULE,
2304	.open    = ipmr_vif_open,
2305	.read    = seq_read,
2306	.llseek  = seq_lseek,
2307	.release = seq_release_net,
2308};
2309
2310struct ipmr_mfc_iter {
2311	struct seq_net_private p;
2312	struct mr_table *mrt;
2313	struct list_head *cache;
2314	int ct;
2315};
2316
2317
2318static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
2319					  struct ipmr_mfc_iter *it, loff_t pos)
2320{
2321	struct mr_table *mrt = it->mrt;
2322	struct mfc_cache *mfc;
2323
2324	rcu_read_lock();
2325	for (it->ct = 0; it->ct < MFC_LINES; it->ct++) {
2326		it->cache = &mrt->mfc_cache_array[it->ct];
2327		list_for_each_entry_rcu(mfc, it->cache, list)
2328			if (pos-- == 0)
2329				return mfc;
2330	}
2331	rcu_read_unlock();
2332
2333	spin_lock_bh(&mfc_unres_lock);
2334	it->cache = &mrt->mfc_unres_queue;
2335	list_for_each_entry(mfc, it->cache, list)
2336		if (pos-- == 0)
2337			return mfc;
2338	spin_unlock_bh(&mfc_unres_lock);
2339
2340	it->cache = NULL;
2341	return NULL;
2342}
2343
2344
2345static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2346{
2347	struct ipmr_mfc_iter *it = seq->private;
2348	struct net *net = seq_file_net(seq);
2349	struct mr_table *mrt;
2350
2351	mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2352	if (mrt == NULL)
2353		return ERR_PTR(-ENOENT);
2354
2355	it->mrt = mrt;
2356	it->cache = NULL;
2357	it->ct = 0;
2358	return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
2359		: SEQ_START_TOKEN;
2360}
2361
2362static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2363{
2364	struct mfc_cache *mfc = v;
2365	struct ipmr_mfc_iter *it = seq->private;
2366	struct net *net = seq_file_net(seq);
2367	struct mr_table *mrt = it->mrt;
2368
2369	++*pos;
2370
2371	if (v == SEQ_START_TOKEN)
2372		return ipmr_mfc_seq_idx(net, seq->private, 0);
2373
2374	if (mfc->list.next != it->cache)
2375		return list_entry(mfc->list.next, struct mfc_cache, list);
2376
2377	if (it->cache == &mrt->mfc_unres_queue)
2378		goto end_of_list;
2379
2380	BUG_ON(it->cache != &mrt->mfc_cache_array[it->ct]);
2381
2382	while (++it->ct < MFC_LINES) {
2383		it->cache = &mrt->mfc_cache_array[it->ct];
2384		if (list_empty(it->cache))
2385			continue;
2386		return list_first_entry(it->cache, struct mfc_cache, list);
2387	}
2388
2389	/* exhausted cache_array, show unresolved */
2390	rcu_read_unlock();
2391	it->cache = &mrt->mfc_unres_queue;
2392	it->ct = 0;
2393
2394	spin_lock_bh(&mfc_unres_lock);
2395	if (!list_empty(it->cache))
2396		return list_first_entry(it->cache, struct mfc_cache, list);
2397
2398end_of_list:
2399	spin_unlock_bh(&mfc_unres_lock);
2400	it->cache = NULL;
2401
2402	return NULL;
2403}
2404
2405static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
2406{
2407	struct ipmr_mfc_iter *it = seq->private;
2408	struct mr_table *mrt = it->mrt;
2409
2410	if (it->cache == &mrt->mfc_unres_queue)
2411		spin_unlock_bh(&mfc_unres_lock);
2412	else if (it->cache == &mrt->mfc_cache_array[it->ct])
2413		rcu_read_unlock();
2414}
2415
2416static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2417{
2418	int n;
2419
2420	if (v == SEQ_START_TOKEN) {
2421		seq_puts(seq,
2422		 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2423	} else {
2424		const struct mfc_cache *mfc = v;
2425		const struct ipmr_mfc_iter *it = seq->private;
2426		const struct mr_table *mrt = it->mrt;
2427
2428		seq_printf(seq, "%08X %08X %-3hd",
2429			   (__force u32) mfc->mfc_mcastgrp,
2430			   (__force u32) mfc->mfc_origin,
2431			   mfc->mfc_parent);
2432
2433		if (it->cache != &mrt->mfc_unres_queue) {
2434			seq_printf(seq, " %8lu %8lu %8lu",
2435				   mfc->mfc_un.res.pkt,
2436				   mfc->mfc_un.res.bytes,
2437				   mfc->mfc_un.res.wrong_if);
2438			for (n = mfc->mfc_un.res.minvif;
2439			     n < mfc->mfc_un.res.maxvif; n++) {
2440				if (VIF_EXISTS(mrt, n) &&
2441				    mfc->mfc_un.res.ttls[n] < 255)
2442					seq_printf(seq,
2443					   " %2d:%-3d",
2444					   n, mfc->mfc_un.res.ttls[n]);
2445			}
2446		} else {
2447			/* unresolved mfc_caches don't contain
2448			 * pkt, bytes and wrong_if values
2449			 */
2450			seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
2451		}
2452		seq_putc(seq, '\n');
2453	}
2454	return 0;
2455}
2456
2457static const struct seq_operations ipmr_mfc_seq_ops = {
2458	.start = ipmr_mfc_seq_start,
2459	.next  = ipmr_mfc_seq_next,
2460	.stop  = ipmr_mfc_seq_stop,
2461	.show  = ipmr_mfc_seq_show,
2462};
2463
2464static int ipmr_mfc_open(struct inode *inode, struct file *file)
2465{
2466	return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
2467			    sizeof(struct ipmr_mfc_iter));
2468}
2469
2470static const struct file_operations ipmr_mfc_fops = {
2471	.owner	 = THIS_MODULE,
2472	.open    = ipmr_mfc_open,
2473	.read    = seq_read,
2474	.llseek  = seq_lseek,
2475	.release = seq_release_net,
2476};
2477#endif
2478
2479#ifdef CONFIG_IP_PIMSM_V2
2480static const struct net_protocol pim_protocol = {
2481	.handler	=	pim_rcv,
2482	.netns_ok	=	1,
2483};
2484#endif
2485
2486
2487/*
2488 *	Setup for IP multicast routing
2489 */
2490static int __net_init ipmr_net_init(struct net *net)
2491{
2492	int err;
2493
2494	err = ipmr_rules_init(net);
2495	if (err < 0)
2496		goto fail;
2497
2498#ifdef CONFIG_PROC_FS
2499	err = -ENOMEM;
2500	if (!proc_net_fops_create(net, "ip_mr_vif", 0, &ipmr_vif_fops))
2501		goto proc_vif_fail;
2502	if (!proc_net_fops_create(net, "ip_mr_cache", 0, &ipmr_mfc_fops))
2503		goto proc_cache_fail;
2504#endif
2505	return 0;
2506
2507#ifdef CONFIG_PROC_FS
2508proc_cache_fail:
2509	proc_net_remove(net, "ip_mr_vif");
2510proc_vif_fail:
2511	ipmr_rules_exit(net);
2512#endif
2513fail:
2514	return err;
2515}
2516
2517static void __net_exit ipmr_net_exit(struct net *net)
2518{
2519#ifdef CONFIG_PROC_FS
2520	proc_net_remove(net, "ip_mr_cache");
2521	proc_net_remove(net, "ip_mr_vif");
2522#endif
2523	ipmr_rules_exit(net);
2524}
2525
2526static struct pernet_operations ipmr_net_ops = {
2527	.init = ipmr_net_init,
2528	.exit = ipmr_net_exit,
2529};
2530
2531int __init ip_mr_init(void)
2532{
2533	int err;
2534
2535	mrt_cachep = kmem_cache_create("ip_mrt_cache",
2536				       sizeof(struct mfc_cache),
2537				       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
2538				       NULL);
2539	if (!mrt_cachep)
2540		return -ENOMEM;
2541
2542	err = register_pernet_subsys(&ipmr_net_ops);
2543	if (err)
2544		goto reg_pernet_fail;
2545
2546	err = register_netdevice_notifier(&ip_mr_notifier);
2547	if (err)
2548		goto reg_notif_fail;
2549#ifdef CONFIG_IP_PIMSM_V2
2550	if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
2551		pr_err("%s: can't add PIM protocol\n", __func__);
2552		err = -EAGAIN;
2553		goto add_proto_fail;
2554	}
2555#endif
2556	rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
2557		      NULL, ipmr_rtm_dumproute, NULL);
2558	return 0;
2559
2560#ifdef CONFIG_IP_PIMSM_V2
2561add_proto_fail:
2562	unregister_netdevice_notifier(&ip_mr_notifier);
2563#endif
2564reg_notif_fail:
2565	unregister_pernet_subsys(&ipmr_net_ops);
2566reg_pernet_fail:
2567	kmem_cache_destroy(mrt_cachep);
2568	return err;
2569}