net/ipv4/ipmr.c

   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/system.h>
  30 #include <asm/uaccess.h>
  31 #include <linux/types.h>
  32 #include <linux/capability.h>
  33 #include <linux/errno.h>
  34 #include <linux/timer.h>
  35 #include <linux/mm.h>
  36 #include <linux/kernel.h>
  37 #include <linux/fcntl.h>
  38 #include <linux/stat.h>
  39 #include <linux/socket.h>
  40 #include <linux/in.h>
  41 #include <linux/inet.h>
  42 #include <linux/netdevice.h>
  43 #include <linux/inetdevice.h>
  44 #include <linux/igmp.h>
  45 #include <linux/proc_fs.h>
  46 #include <linux/seq_file.h>
  47 #include <linux/mroute.h>
  48 #include <linux/init.h>
  49 #include <linux/if_ether.h>
  50 #include <linux/slab.h>
  51 #include <net/net_namespace.h>
  52 #include <net/ip.h>
  53 #include <net/protocol.h>
  54 #include <linux/skbuff.h>
  55 #include <net/route.h>
  56 #include <net/sock.h>
  57 #include <net/icmp.h>
  58 #include <net/udp.h>
  59 #include <net/raw.h>
  60 #include <linux/notifier.h>
  61 #include <linux/if_arp.h>
  62 #include <linux/netfilter_ipv4.h>
  63 #include <net/ipip.h>
  64 #include <net/checksum.h>
  65 #include <net/netlink.h>
  66 #include <net/fib_rules.h>
  67
  68 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
  69 #define CONFIG_IP_PIMSM 1
  70 #endif
  71
  72 struct mr_table {
  73         struct list_head        list;
  74 #ifdef CONFIG_NET_NS
  75         struct net              *net;
  76 #endif
  77         u32                     id;
  78         struct sock __rcu       *mroute_sk;
  79         struct timer_list       ipmr_expire_timer;
  80         struct list_head        mfc_unres_queue;
  81         struct list_head        mfc_cache_array[MFC_LINES];
  82         struct vif_device       vif_table[MAXVIFS];
  83         int                     maxvif;
  84         atomic_t                cache_resolve_queue_len;
  85         int                     mroute_do_assert;
  86         int                     mroute_do_pim;
  87 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
  88         int                     mroute_reg_vif_num;
  89 #endif
  90 };
  91
  92 struct ipmr_rule {
  93         struct fib_rule         common;
  94 };
  95
  96 struct ipmr_result {
  97         struct mr_table         *mrt;
  98 };
  99
 100 /* Big lock, protecting vif table, mrt cache and mroute socket state.
 101  * Note that the changes are semaphored via rtnl_lock.
 102  */
 103
 104 static DEFINE_RWLOCK(mrt_lock);
 105
 106 /*
 107  *      Multicast router control variables
 108  */
 109
 110 #define VIF_EXISTS(_mrt, _idx) ((_mrt)->vif_table[_idx].dev != NULL)
 111
 112 /* Special spinlock for queue of unresolved entries */
 113 static DEFINE_SPINLOCK(mfc_unres_lock);
 114
 115 /* We return to original Alan's scheme. Hash table of resolved
 116  * entries is changed only in process context and protected
 117  * with weak lock mrt_lock. Queue of unresolved entries is protected
 118  * with strong spinlock mfc_unres_lock.
 119  *
 120  * In this case data path is free of exclusive locks at all.
 121  */
 122
 123 static struct kmem_cache *mrt_cachep __read_mostly;
 124
 125 static struct mr_table *ipmr_new_table(struct net *net, u32 id);
 126 static int ip_mr_forward(struct net *net, struct mr_table *mrt,
 127                          struct sk_buff *skb, struct mfc_cache *cache,
 128                          int local);
 129 static int ipmr_cache_report(struct mr_table *mrt,
 130                              struct sk_buff *pkt, vifi_t vifi, int assert);
 131 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
 132                               struct mfc_cache *c, struct rtmsg *rtm);
 133 static void ipmr_expire_process(unsigned long arg);
 134
 135 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
 136 #define ipmr_for_each_table(mrt, net) \
 137         list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
 138
 139 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
 140 {
 141         struct mr_table *mrt;
 142
 143         ipmr_for_each_table(mrt, net) {
 144                 if (mrt->id == id)
 145                         return mrt;
 146         }
 147         return NULL;
 148 }
 149
 150 static int ipmr_fib_lookup(struct net *net, struct flowi *flp,
 151                            struct mr_table **mrt)
 152 {
 153         struct ipmr_result res;
 154         struct fib_lookup_arg arg = { .result = &res, };
 155         int err;
 156
 157         err = fib_rules_lookup(net->ipv4.mr_rules_ops, flp, 0, &arg);
 158         if (err < 0)
 159                 return err;
 160         *mrt = res.mrt;
 161         return 0;
 162 }
 163
 164 static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
 165                             int flags, struct fib_lookup_arg *arg)
 166 {
 167         struct ipmr_result *res = arg->result;
 168         struct mr_table *mrt;
 169
 170         switch (rule->action) {
 171         case FR_ACT_TO_TBL:
 172                 break;
 173         case FR_ACT_UNREACHABLE:
 174                 return -ENETUNREACH;
 175         case FR_ACT_PROHIBIT:
 176                 return -EACCES;
 177         case FR_ACT_BLACKHOLE:
 178         default:
 179                 return -EINVAL;
 180         }
 181
 182         mrt = ipmr_get_table(rule->fr_net, rule->table);
 183         if (mrt == NULL)
 184                 return -EAGAIN;
 185         res->mrt = mrt;
 186         return 0;
 187 }
 188
 189 static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
 190 {
 191         return 1;
 192 }
 193
 194 static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
 195         FRA_GENERIC_POLICY,
 196 };
 197
 198 static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
 199                                struct fib_rule_hdr *frh, struct nlattr **tb)
 200 {
 201         return 0;
 202 }
 203
 204 static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
 205                              struct nlattr **tb)
 206 {
 207         return 1;
 208 }
 209
 210 static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
 211                           struct fib_rule_hdr *frh)
 212 {
 213         frh->dst_len = 0;
 214         frh->src_len = 0;
 215         frh->tos     = 0;
 216         return 0;
 217 }
 218
 219 static const struct fib_rules_ops __net_initdata ipmr_rules_ops_template = {
 220         .family         = RTNL_FAMILY_IPMR,
 221         .rule_size      = sizeof(struct ipmr_rule),
 222         .addr_size      = sizeof(u32),
 223         .action         = ipmr_rule_action,
 224         .match          = ipmr_rule_match,
 225         .configure      = ipmr_rule_configure,
 226         .compare        = ipmr_rule_compare,
 227         .default_pref   = fib_default_rule_pref,
 228         .fill           = ipmr_rule_fill,
 229         .nlgroup        = RTNLGRP_IPV4_RULE,
 230         .policy         = ipmr_rule_policy,
 231         .owner          = THIS_MODULE,
 232 };
 233
 234 static int __net_init ipmr_rules_init(struct net *net)
 235 {
 236         struct fib_rules_ops *ops;
 237         struct mr_table *mrt;
 238         int err;
 239
 240         ops = fib_rules_register(&ipmr_rules_ops_template, net);
 241         if (IS_ERR(ops))
 242                 return PTR_ERR(ops);
 243
 244         INIT_LIST_HEAD(&net->ipv4.mr_tables);
 245
 246         mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
 247         if (mrt == NULL) {
 248                 err = -ENOMEM;
 249                 goto err1;
 250         }
 251
 252         err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
 253         if (err < 0)
 254                 goto err2;
 255
 256         net->ipv4.mr_rules_ops = ops;
 257         return 0;
 258
 259 err2:
 260         kfree(mrt);
 261 err1:
 262         fib_rules_unregister(ops);
 263         return err;
 264 }
 265
 266 static void __net_exit ipmr_rules_exit(struct net *net)
 267 {
 268         struct mr_table *mrt, *next;
 269
 270         list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
 271                 list_del(&mrt->list);
 272                 kfree(mrt);
 273         }
 274         fib_rules_unregister(net->ipv4.mr_rules_ops);
 275 }
 276 #else
 277 #define ipmr_for_each_table(mrt, net) \
 278         for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
 279
 280 static struct mr_table *ipmr_get_table(struct net *net, u32 id)
 281 {
 282         return net->ipv4.mrt;
 283 }
 284
 285 static int ipmr_fib_lookup(struct net *net, struct flowi *flp,
 286                            struct mr_table **mrt)
 287 {
 288         *mrt = net->ipv4.mrt;
 289         return 0;
 290 }
 291
 292 static int __net_init ipmr_rules_init(struct net *net)
 293 {
 294         net->ipv4.mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
 295         return net->ipv4.mrt ? 0 : -ENOMEM;
 296 }
 297
 298 static void __net_exit ipmr_rules_exit(struct net *net)
 299 {
 300         kfree(net->ipv4.mrt);
 301 }
 302 #endif
 303
 304 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
 305 {
 306         struct mr_table *mrt;
 307         unsigned int i;
 308
 309         mrt = ipmr_get_table(net, id);
 310         if (mrt != NULL)
 311                 return mrt;
 312
 313         mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
 314         if (mrt == NULL)
 315                 return NULL;
 316         write_pnet(&mrt->net, net);
 317         mrt->id = id;
 318
 319         /* Forwarding cache */
 320         for (i = 0; i < MFC_LINES; i++)
 321                 INIT_LIST_HEAD(&mrt->mfc_cache_array[i]);
 322
 323         INIT_LIST_HEAD(&mrt->mfc_unres_queue);
 324
 325         setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
 326                     (unsigned long)mrt);
 327
 328 #ifdef CONFIG_IP_PIMSM
 329         mrt->mroute_reg_vif_num = -1;
 330 #endif
 331 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
 332         list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
 333 #endif
 334         return mrt;
 335 }
 336
 337 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
 338
 339 static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
 340 {
 341         struct net *net = dev_net(dev);
 342
 343         dev_close(dev);
 344
 345         dev = __dev_get_by_name(net, "tunl0");
 346         if (dev) {
 347                 const struct net_device_ops *ops = dev->netdev_ops;
 348                 struct ifreq ifr;
 349                 struct ip_tunnel_parm p;
 350
 351                 memset(&p, 0, sizeof(p));
 352                 p.iph.daddr = v->vifc_rmt_addr.s_addr;
 353                 p.iph.saddr = v->vifc_lcl_addr.s_addr;
 354                 p.iph.version = 4;
 355                 p.iph.ihl = 5;
 356                 p.iph.protocol = IPPROTO_IPIP;
 357                 sprintf(p.name, "dvmrp%d", v->vifc_vifi);
 358                 ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
 359
 360                 if (ops->ndo_do_ioctl) {
 361                         mm_segment_t oldfs = get_fs();
 362
 363                         set_fs(KERNEL_DS);
 364                         ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
 365                         set_fs(oldfs);
 366                 }
 367         }
 368 }
 369
 370 static
 371 struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
 372 {
 373         struct net_device  *dev;
 374
 375         dev = __dev_get_by_name(net, "tunl0");
 376
 377         if (dev) {
 378                 const struct net_device_ops *ops = dev->netdev_ops;
 379                 int err;
 380                 struct ifreq ifr;
 381                 struct ip_tunnel_parm p;
 382                 struct in_device  *in_dev;
 383
 384                 memset(&p, 0, sizeof(p));
 385                 p.iph.daddr = v->vifc_rmt_addr.s_addr;
 386                 p.iph.saddr = v->vifc_lcl_addr.s_addr;
 387                 p.iph.version = 4;
 388                 p.iph.ihl = 5;
 389                 p.iph.protocol = IPPROTO_IPIP;
 390                 sprintf(p.name, "dvmrp%d", v->vifc_vifi);
 391                 ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
 392
 393                 if (ops->ndo_do_ioctl) {
 394                         mm_segment_t oldfs = get_fs();
 395
 396                         set_fs(KERNEL_DS);
 397                         err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
 398                         set_fs(oldfs);
 399                 } else {
 400                         err = -EOPNOTSUPP;
 401                 }
 402                 dev = NULL;
 403
 404                 if (err == 0 &&
 405                     (dev = __dev_get_by_name(net, p.name)) != NULL) {
 406                         dev->flags |= IFF_MULTICAST;
 407
 408                         in_dev = __in_dev_get_rtnl(dev);
 409                         if (in_dev == NULL)
 410                                 goto failure;
 411
 412                         ipv4_devconf_setall(in_dev);
 413                         IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
 414
 415                         if (dev_open(dev))
 416                                 goto failure;
 417                         dev_hold(dev);
 418                 }
 419         }
 420         return dev;
 421
 422 failure:
 423         /* allow the register to be completed before unregistering. */
 424         rtnl_unlock();
 425         rtnl_lock();
 426
 427         unregister_netdevice(dev);
 428         return NULL;
 429 }
 430
 431 #ifdef CONFIG_IP_PIMSM
 432
 433 static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
 434 {
 435         struct net *net = dev_net(dev);
 436         struct mr_table *mrt;
 437         struct flowi fl = {
 438                 .oif            = dev->ifindex,
 439                 .iif            = skb->skb_iif,
 440                 .mark           = skb->mark,
 441         };
 442         int err;
 443
 444         err = ipmr_fib_lookup(net, &fl, &mrt);
 445         if (err < 0) {
 446                 kfree_skb(skb);
 447                 return err;
 448         }
 449
 450         read_lock(&mrt_lock);
 451         dev->stats.tx_bytes += skb->len;
 452         dev->stats.tx_packets++;
 453         ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
 454         read_unlock(&mrt_lock);
 455         kfree_skb(skb);
 456         return NETDEV_TX_OK;
 457 }
 458
 459 static const struct net_device_ops reg_vif_netdev_ops = {
 460         .ndo_start_xmit = reg_vif_xmit,
 461 };
 462
 463 static void reg_vif_setup(struct net_device *dev)
 464 {
 465         dev->type               = ARPHRD_PIMREG;
 466         dev->mtu                = ETH_DATA_LEN - sizeof(struct iphdr) - 8;
 467         dev->flags              = IFF_NOARP;
 468         dev->netdev_ops         = &reg_vif_netdev_ops,
 469         dev->destructor         = free_netdev;
 470         dev->features           |= NETIF_F_NETNS_LOCAL;
 471 }
 472
 473 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
 474 {
 475         struct net_device *dev;
 476         struct in_device *in_dev;
 477         char name[IFNAMSIZ];
 478
 479         if (mrt->id == RT_TABLE_DEFAULT)
 480                 sprintf(name, "pimreg");
 481         else
 482                 sprintf(name, "pimreg%u", mrt->id);
 483
 484         dev = alloc_netdev(0, name, reg_vif_setup);
 485
 486         if (dev == NULL)
 487                 return NULL;
 488
 489         dev_net_set(dev, net);
 490
 491         if (register_netdevice(dev)) {
 492                 free_netdev(dev);
 493                 return NULL;
 494         }
 495         dev->iflink = 0;
 496
 497         rcu_read_lock();
 498         in_dev = __in_dev_get_rcu(dev);
 499         if (!in_dev) {
 500                 rcu_read_unlock();
 501                 goto failure;
 502         }
 503
 504         ipv4_devconf_setall(in_dev);
 505         IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
 506         rcu_read_unlock();
 507
 508         if (dev_open(dev))
 509                 goto failure;
 510
 511         dev_hold(dev);
 512
 513         return dev;
 514
 515 failure:
 516         /* allow the register to be completed before unregistering. */
 517         rtnl_unlock();
 518         rtnl_lock();
 519
 520         unregister_netdevice(dev);
 521         return NULL;
 522 }
 523 #endif
 524
 525 /*
 526  *      Delete a VIF entry
 527  *      @notify: Set to 1, if the caller is a notifier_call
 528  */
 529
 530 static int vif_delete(struct mr_table *mrt, int vifi, int notify,
 531                       struct list_head *head)
 532 {
 533         struct vif_device *v;
 534         struct net_device *dev;
 535         struct in_device *in_dev;
 536
 537         if (vifi < 0 || vifi >= mrt->maxvif)
 538                 return -EADDRNOTAVAIL;
 539
 540         v = &mrt->vif_table[vifi];
 541
 542         write_lock_bh(&mrt_lock);
 543         dev = v->dev;
 544         v->dev = NULL;
 545
 546         if (!dev) {
 547                 write_unlock_bh(&mrt_lock);
 548                 return -EADDRNOTAVAIL;
 549         }
 550
 551 #ifdef CONFIG_IP_PIMSM
 552         if (vifi == mrt->mroute_reg_vif_num)
 553                 mrt->mroute_reg_vif_num = -1;
 554 #endif
 555
 556         if (vifi + 1 == mrt->maxvif) {
 557                 int tmp;
 558
 559                 for (tmp = vifi - 1; tmp >= 0; tmp--) {
 560                         if (VIF_EXISTS(mrt, tmp))
 561                                 break;
 562                 }
 563                 mrt->maxvif = tmp+1;
 564         }
 565
 566         write_unlock_bh(&mrt_lock);
 567
 568         dev_set_allmulti(dev, -1);
 569
 570         in_dev = __in_dev_get_rtnl(dev);
 571         if (in_dev) {
 572                 IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
 573                 ip_rt_multicast_event(in_dev);
 574         }
 575
 576         if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
 577                 unregister_netdevice_queue(dev, head);
 578
 579         dev_put(dev);
 580         return 0;
 581 }
 582
 583 static void ipmr_cache_free_rcu(struct rcu_head *head)
 584 {
 585         struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
 586
 587         kmem_cache_free(mrt_cachep, c);
 588 }
 589
 590 static inline void ipmr_cache_free(struct mfc_cache *c)
 591 {
 592         call_rcu(&c->rcu, ipmr_cache_free_rcu);
 593 }
 594
 595 /* Destroy an unresolved cache entry, killing queued skbs
 596  * and reporting error to netlink readers.
 597  */
 598
 599 static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
 600 {
 601         struct net *net = read_pnet(&mrt->net);
 602         struct sk_buff *skb;
 603         struct nlmsgerr *e;
 604
 605         atomic_dec(&mrt->cache_resolve_queue_len);
 606
 607         while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
 608                 if (ip_hdr(skb)->version == 0) {
 609                         struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
 610                         nlh->nlmsg_type = NLMSG_ERROR;
 611                         nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
 612                         skb_trim(skb, nlh->nlmsg_len);
 613                         e = NLMSG_DATA(nlh);
 614                         e->error = -ETIMEDOUT;
 615                         memset(&e->msg, 0, sizeof(e->msg));
 616
 617                         rtnl_unicast(skb, net, NETLINK_CB(skb).pid);
 618                 } else {
 619                         kfree_skb(skb);
 620                 }
 621         }
 622
 623         ipmr_cache_free(c);
 624 }
 625
 626
 627 /* Timer process for the unresolved queue. */
 628
 629 static void ipmr_expire_process(unsigned long arg)
 630 {
 631         struct mr_table *mrt = (struct mr_table *)arg;
 632         unsigned long now;
 633         unsigned long expires;
 634         struct mfc_cache *c, *next;
 635
 636         if (!spin_trylock(&mfc_unres_lock)) {
 637                 mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
 638                 return;
 639         }
 640
 641         if (list_empty(&mrt->mfc_unres_queue))
 642                 goto out;
 643
 644         now = jiffies;
 645         expires = 10*HZ;
 646
 647         list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
 648                 if (time_after(c->mfc_un.unres.expires, now)) {
 649                         unsigned long interval = c->mfc_un.unres.expires - now;
 650                         if (interval < expires)
 651                                 expires = interval;
 652                         continue;
 653                 }
 654
 655                 list_del(&c->list);
 656                 ipmr_destroy_unres(mrt, c);
 657         }
 658
 659         if (!list_empty(&mrt->mfc_unres_queue))
 660                 mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
 661
 662 out:
 663         spin_unlock(&mfc_unres_lock);
 664 }
 665
 666 /* Fill oifs list. It is called under write locked mrt_lock. */
 667
 668 static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
 669                                    unsigned char *ttls)
 670 {
 671         int vifi;
 672
 673         cache->mfc_un.res.minvif = MAXVIFS;
 674         cache->mfc_un.res.maxvif = 0;
 675         memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
 676
 677         for (vifi = 0; vifi < mrt->maxvif; vifi++) {
 678                 if (VIF_EXISTS(mrt, vifi) &&
 679                     ttls[vifi] && ttls[vifi] < 255) {
 680                         cache->mfc_un.res.ttls[vifi] = ttls[vifi];
 681                         if (cache->mfc_un.res.minvif > vifi)
 682                                 cache->mfc_un.res.minvif = vifi;
 683                         if (cache->mfc_un.res.maxvif <= vifi)
 684                                 cache->mfc_un.res.maxvif = vifi + 1;
 685                 }
 686         }
 687 }
 688
 689 static int vif_add(struct net *net, struct mr_table *mrt,
 690                    struct vifctl *vifc, int mrtsock)
 691 {
 692         int vifi = vifc->vifc_vifi;
 693         struct vif_device *v = &mrt->vif_table[vifi];
 694         struct net_device *dev;
 695         struct in_device *in_dev;
 696         int err;
 697
 698         /* Is vif busy ? */
 699         if (VIF_EXISTS(mrt, vifi))
 700                 return -EADDRINUSE;
 701
 702         switch (vifc->vifc_flags) {
 703 #ifdef CONFIG_IP_PIMSM
 704         case VIFF_REGISTER:
 705                 /*
 706                  * Special Purpose VIF in PIM
 707                  * All the packets will be sent to the daemon
 708                  */
 709                 if (mrt->mroute_reg_vif_num >= 0)
 710                         return -EADDRINUSE;
 711                 dev = ipmr_reg_vif(net, mrt);
 712                 if (!dev)
 713                         return -ENOBUFS;
 714                 err = dev_set_allmulti(dev, 1);
 715                 if (err) {
 716                         unregister_netdevice(dev);
 717                         dev_put(dev);
 718                         return err;
 719                 }
 720                 break;
 721 #endif
 722         case VIFF_TUNNEL:
 723                 dev = ipmr_new_tunnel(net, vifc);
 724                 if (!dev)
 725                         return -ENOBUFS;
 726                 err = dev_set_allmulti(dev, 1);
 727                 if (err) {
 728                         ipmr_del_tunnel(dev, vifc);
 729                         dev_put(dev);
 730                         return err;
 731                 }
 732                 break;
 733
 734         case VIFF_USE_IFINDEX:
 735         case 0:
 736                 if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
 737                         dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
 738                         if (dev && __in_dev_get_rtnl(dev) == NULL) {
 739                                 dev_put(dev);
 740                                 return -EADDRNOTAVAIL;
 741                         }
 742                 } else {
 743                         dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
 744                 }
 745                 if (!dev)
 746                         return -EADDRNOTAVAIL;
 747                 err = dev_set_allmulti(dev, 1);
 748                 if (err) {
 749                         dev_put(dev);
 750                         return err;
 751                 }
 752                 break;
 753         default:
 754                 return -EINVAL;
 755         }
 756
 757         in_dev = __in_dev_get_rtnl(dev);
 758         if (!in_dev) {
 759                 dev_put(dev);
 760                 return -EADDRNOTAVAIL;
 761         }
 762         IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
 763         ip_rt_multicast_event(in_dev);
 764
 765         /* Fill in the VIF structures */
 766
 767         v->rate_limit = vifc->vifc_rate_limit;
 768         v->local = vifc->vifc_lcl_addr.s_addr;
 769         v->remote = vifc->vifc_rmt_addr.s_addr;
 770         v->flags = vifc->vifc_flags;
 771         if (!mrtsock)
 772                 v->flags |= VIFF_STATIC;
 773         v->threshold = vifc->vifc_threshold;
 774         v->bytes_in = 0;
 775         v->bytes_out = 0;
 776         v->pkt_in = 0;
 777         v->pkt_out = 0;
 778         v->link = dev->ifindex;
 779         if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
 780                 v->link = dev->iflink;
 781
 782         /* And finish update writing critical data */
 783         write_lock_bh(&mrt_lock);
 784         v->dev = dev;
 785 #ifdef CONFIG_IP_PIMSM
 786         if (v->flags & VIFF_REGISTER)
 787                 mrt->mroute_reg_vif_num = vifi;
 788 #endif
 789         if (vifi+1 > mrt->maxvif)
 790                 mrt->maxvif = vifi+1;
 791         write_unlock_bh(&mrt_lock);
 792         return 0;
 793 }
 794
 795 /* called with rcu_read_lock() */
 796 static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
 797                                          __be32 origin,
 798                                          __be32 mcastgrp)
 799 {
 800         int line = MFC_HASH(mcastgrp, origin);
 801         struct mfc_cache *c;
 802
 803         list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list) {
 804                 if (c->mfc_origin == origin && c->mfc_mcastgrp == mcastgrp)
 805                         return c;
 806         }
 807         return NULL;
 808 }
 809
 810 /*
 811  *      Allocate a multicast cache entry
 812  */
 813 static struct mfc_cache *ipmr_cache_alloc(void)
 814 {
 815         struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
 816
 817         if (c)
 818                 c->mfc_un.res.minvif = MAXVIFS;
 819         return c;
 820 }
 821
 822 static struct mfc_cache *ipmr_cache_alloc_unres(void)
 823 {
 824         struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
 825
 826         if (c) {
 827                 skb_queue_head_init(&c->mfc_un.unres.unresolved);
 828                 c->mfc_un.unres.expires = jiffies + 10*HZ;
 829         }
 830         return c;
 831 }
 832
 833 /*
 834  *      A cache entry has gone into a resolved state from queued
 835  */
 836
 837 static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
 838                                struct mfc_cache *uc, struct mfc_cache *c)
 839 {
 840         struct sk_buff *skb;
 841         struct nlmsgerr *e;
 842
 843         /* Play the pending entries through our router */
 844
 845         while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
 846                 if (ip_hdr(skb)->version == 0) {
 847                         struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
 848
 849                         if (__ipmr_fill_mroute(mrt, skb, c, NLMSG_DATA(nlh)) > 0) {
 850                                 nlh->nlmsg_len = skb_tail_pointer(skb) -
 851                                                  (u8 *)nlh;
 852                         } else {
 853                                 nlh->nlmsg_type = NLMSG_ERROR;
 854                                 nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
 855                                 skb_trim(skb, nlh->nlmsg_len);
 856                                 e = NLMSG_DATA(nlh);
 857                                 e->error = -EMSGSIZE;
 858                                 memset(&e->msg, 0, sizeof(e->msg));
 859                         }
 860
 861                         rtnl_unicast(skb, net, NETLINK_CB(skb).pid);
 862                 } else {
 863                         ip_mr_forward(net, mrt, skb, c, 0);
 864                 }
 865         }
 866 }
 867
 868 /*
 869  *      Bounce a cache query up to mrouted. We could use netlink for this but mrouted
 870  *      expects the following bizarre scheme.
 871  *
 872  *      Called under mrt_lock.
 873  */
 874
 875 static int ipmr_cache_report(struct mr_table *mrt,
 876                              struct sk_buff *pkt, vifi_t vifi, int assert)
 877 {
 878         struct sk_buff *skb;
 879         const int ihl = ip_hdrlen(pkt);
 880         struct igmphdr *igmp;
 881         struct igmpmsg *msg;
 882         struct sock *mroute_sk;
 883         int ret;
 884
 885 #ifdef CONFIG_IP_PIMSM
 886         if (assert == IGMPMSG_WHOLEPKT)
 887                 skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
 888         else
 889 #endif
 890                 skb = alloc_skb(128, GFP_ATOMIC);
 891
 892         if (!skb)
 893                 return -ENOBUFS;
 894
 895 #ifdef CONFIG_IP_PIMSM
 896         if (assert == IGMPMSG_WHOLEPKT) {
 897                 /* Ugly, but we have no choice with this interface.
 898                  * Duplicate old header, fix ihl, length etc.
 899                  * And all this only to mangle msg->im_msgtype and
 900                  * to set msg->im_mbz to "mbz" :-)
 901                  */
 902                 skb_push(skb, sizeof(struct iphdr));
 903                 skb_reset_network_header(skb);
 904                 skb_reset_transport_header(skb);
 905                 msg = (struct igmpmsg *)skb_network_header(skb);
 906                 memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
 907                 msg->im_msgtype = IGMPMSG_WHOLEPKT;
 908                 msg->im_mbz = 0;
 909                 msg->im_vif = mrt->mroute_reg_vif_num;
 910                 ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
 911                 ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
 912                                              sizeof(struct iphdr));
 913         } else
 914 #endif
 915         {
 916
 917         /* Copy the IP header */
 918
 919         skb->network_header = skb->tail;
 920         skb_put(skb, ihl);
 921         skb_copy_to_linear_data(skb, pkt->data, ihl);
 922         ip_hdr(skb)->protocol = 0;      /* Flag to the kernel this is a route add */
 923         msg = (struct igmpmsg *)skb_network_header(skb);
 924         msg->im_vif = vifi;
 925         skb_dst_set(skb, dst_clone(skb_dst(pkt)));
 926
 927         /* Add our header */
 928
 929         igmp = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
 930         igmp->type      =
 931         msg->im_msgtype = assert;
 932         igmp->code      = 0;
 933         ip_hdr(skb)->tot_len = htons(skb->len);         /* Fix the length */
 934         skb->transport_header = skb->network_header;
 935         }
 936
 937         rcu_read_lock();
 938         mroute_sk = rcu_dereference(mrt->mroute_sk);
 939         if (mroute_sk == NULL) {
 940                 rcu_read_unlock();
 941                 kfree_skb(skb);
 942                 return -EINVAL;
 943         }
 944
 945         /* Deliver to mrouted */
 946
 947         ret = sock_queue_rcv_skb(mroute_sk, skb);
 948         rcu_read_unlock();
 949         if (ret < 0) {
 950                 if (net_ratelimit())
 951                         printk(KERN_WARNING "mroute: pending queue full, dropping entries.\n");
 952                 kfree_skb(skb);
 953         }
 954
 955         return ret;
 956 }
 957
 958 /*
 959  *      Queue a packet for resolution. It gets locked cache entry!
 960  */
 961
 962 static int
 963 ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi, struct sk_buff *skb)
 964 {
 965         bool found = false;
 966         int err;
 967         struct mfc_cache *c;
 968         const struct iphdr *iph = ip_hdr(skb);
 969
 970         spin_lock_bh(&mfc_unres_lock);
 971         list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
 972                 if (c->mfc_mcastgrp == iph->daddr &&
 973                     c->mfc_origin == iph->saddr) {
 974                         found = true;
 975                         break;
 976                 }
 977         }
 978
 979         if (!found) {
 980                 /* Create a new entry if allowable */
 981
 982                 if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
 983                     (c = ipmr_cache_alloc_unres()) == NULL) {
 984                         spin_unlock_bh(&mfc_unres_lock);
 985
 986                         kfree_skb(skb);
 987                         return -ENOBUFS;
 988                 }
 989
 990                 /* Fill in the new cache entry */
 991
 992                 c->mfc_parent   = -1;
 993                 c->mfc_origin   = iph->saddr;
 994                 c->mfc_mcastgrp = iph->daddr;
 995
 996                 /* Reflect first query at mrouted. */
 997
 998                 err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
 999                 if (err < 0) {
1000                         /* If the report failed throw the cache entry
1001                            out - Brad Parker
1002                          */
1003                         spin_unlock_bh(&mfc_unres_lock);
1004
1005                         ipmr_cache_free(c);
1006                         kfree_skb(skb);
1007                         return err;
1008                 }
1009
1010                 atomic_inc(&mrt->cache_resolve_queue_len);
1011                 list_add(&c->list, &mrt->mfc_unres_queue);
1012
1013                 if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1014                         mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1015         }
1016
1017         /* See if we can append the packet */
1018
1019         if (c->mfc_un.unres.unresolved.qlen > 3) {
1020                 kfree_skb(skb);
1021                 err = -ENOBUFS;
1022         } else {
1023                 skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1024                 err = 0;
1025         }
1026
1027         spin_unlock_bh(&mfc_unres_lock);
1028         return err;
1029 }
1030
1031 /*
1032  *      MFC cache manipulation by user space mroute daemon
1033  */
1034
1035 static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc)
1036 {
1037         int line;
1038         struct mfc_cache *c, *next;
1039
1040         line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1041
1042         list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[line], list) {
1043                 if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1044                     c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
1045                         list_del_rcu(&c->list);
1046
1047                         ipmr_cache_free(c);
1048                         return 0;
1049                 }
1050         }
1051         return -ENOENT;
1052 }
1053
1054 static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1055                         struct mfcctl *mfc, int mrtsock)
1056 {
1057         bool found = false;
1058         int line;
1059         struct mfc_cache *uc, *c;
1060
1061         if (mfc->mfcc_parent >= MAXVIFS)
1062                 return -ENFILE;
1063
1064         line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1065
1066         list_for_each_entry(c, &mrt->mfc_cache_array[line], list) {
1067                 if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1068                     c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
1069                         found = true;
1070                         break;
1071                 }
1072         }
1073
1074         if (found) {
1075                 write_lock_bh(&mrt_lock);
1076                 c->mfc_parent = mfc->mfcc_parent;
1077                 ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1078                 if (!mrtsock)
1079                         c->mfc_flags |= MFC_STATIC;
1080                 write_unlock_bh(&mrt_lock);
1081                 return 0;
1082         }
1083
1084         if (!ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1085                 return -EINVAL;
1086
1087         c = ipmr_cache_alloc();
1088         if (c == NULL)
1089                 return -ENOMEM;
1090
1091         c->mfc_origin = mfc->mfcc_origin.s_addr;
1092         c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1093         c->mfc_parent = mfc->mfcc_parent;
1094         ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1095         if (!mrtsock)
1096                 c->mfc_flags |= MFC_STATIC;
1097
1098         list_add_rcu(&c->list, &mrt->mfc_cache_array[line]);
1099
1100         /*
1101          *      Check to see if we resolved a queued list. If so we
1102          *      need to send on the frames and tidy up.
1103          */
1104         found = false;
1105         spin_lock_bh(&mfc_unres_lock);
1106         list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1107                 if (uc->mfc_origin == c->mfc_origin &&
1108                     uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1109                         list_del(&uc->list);
1110                         atomic_dec(&mrt->cache_resolve_queue_len);
1111                         found = true;
1112                         break;
1113                 }
1114         }
1115         if (list_empty(&mrt->mfc_unres_queue))
1116                 del_timer(&mrt->ipmr_expire_timer);
1117         spin_unlock_bh(&mfc_unres_lock);
1118
1119         if (found) {
1120                 ipmr_cache_resolve(net, mrt, uc, c);
1121                 ipmr_cache_free(uc);
1122         }
1123         return 0;
1124 }
1125
1126 /*
1127  *      Close the multicast socket, and clear the vif tables etc
1128  */
1129
1130 static void mroute_clean_tables(struct mr_table *mrt)
1131 {
1132         int i;
1133         LIST_HEAD(list);
1134         struct mfc_cache *c, *next;
1135
1136         /* Shut down all active vif entries */
1137
1138         for (i = 0; i < mrt->maxvif; i++) {
1139                 if (!(mrt->vif_table[i].flags & VIFF_STATIC))
1140                         vif_delete(mrt, i, 0, &list);
1141         }
1142         unregister_netdevice_many(&list);
1143
1144         /* Wipe the cache */
1145
1146         for (i = 0; i < MFC_LINES; i++) {
1147                 list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[i], list) {
1148                         if (c->mfc_flags & MFC_STATIC)
1149                                 continue;
1150                         list_del_rcu(&c->list);
1151                         ipmr_cache_free(c);
1152                 }
1153         }
1154
1155         if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1156                 spin_lock_bh(&mfc_unres_lock);
1157                 list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
1158                         list_del(&c->list);
1159                         ipmr_destroy_unres(mrt, c);
1160                 }
1161                 spin_unlock_bh(&mfc_unres_lock);
1162         }
1163 }
1164
1165 /* called from ip_ra_control(), before an RCU grace period,
1166  * we dont need to call synchronize_rcu() here
1167  */
1168 static void mrtsock_destruct(struct sock *sk)
1169 {
1170         struct net *net = sock_net(sk);
1171         struct mr_table *mrt;
1172
1173         rtnl_lock();
1174         ipmr_for_each_table(mrt, net) {
1175                 if (sk == rtnl_dereference(mrt->mroute_sk)) {
1176                         IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1177                         rcu_assign_pointer(mrt->mroute_sk, NULL);
1178                         mroute_clean_tables(mrt);
1179                 }
1180         }
1181         rtnl_unlock();
1182 }
1183
1184 /*
1185  *      Socket options and virtual interface manipulation. The whole
1186  *      virtual interface system is a complete heap, but unfortunately
1187  *      that's how BSD mrouted happens to think. Maybe one day with a proper
1188  *      MOSPF/PIM router set up we can clean this up.
1189  */
1190
1191 int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen)
1192 {
1193         int ret;
1194         struct vifctl vif;
1195         struct mfcctl mfc;
1196         struct net *net = sock_net(sk);
1197         struct mr_table *mrt;
1198
1199         mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1200         if (mrt == NULL)
1201                 return -ENOENT;
1202
1203         if (optname != MRT_INIT) {
1204                 if (sk != rcu_dereference_raw(mrt->mroute_sk) &&
1205                     !capable(CAP_NET_ADMIN))
1206                         return -EACCES;
1207         }
1208
1209         switch (optname) {
1210         case MRT_INIT:
1211                 if (sk->sk_type != SOCK_RAW ||
1212                     inet_sk(sk)->inet_num != IPPROTO_IGMP)
1213                         return -EOPNOTSUPP;
1214                 if (optlen != sizeof(int))
1215                         return -ENOPROTOOPT;
1216
1217                 rtnl_lock();
1218                 if (rtnl_dereference(mrt->mroute_sk)) {
1219                         rtnl_unlock();
1220                         return -EADDRINUSE;
1221                 }
1222
1223                 ret = ip_ra_control(sk, 1, mrtsock_destruct);
1224                 if (ret == 0) {
1225                         rcu_assign_pointer(mrt->mroute_sk, sk);
1226                         IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1227                 }
1228                 rtnl_unlock();
1229                 return ret;
1230         case MRT_DONE:
1231                 if (sk != rcu_dereference_raw(mrt->mroute_sk))
1232                         return -EACCES;
1233                 return ip_ra_control(sk, 0, NULL);
1234         case MRT_ADD_VIF:
1235         case MRT_DEL_VIF:
1236                 if (optlen != sizeof(vif))
1237                         return -EINVAL;
1238                 if (copy_from_user(&vif, optval, sizeof(vif)))
1239                         return -EFAULT;
1240                 if (vif.vifc_vifi >= MAXVIFS)
1241                         return -ENFILE;
1242                 rtnl_lock();
1243                 if (optname == MRT_ADD_VIF) {
1244                         ret = vif_add(net, mrt, &vif,
1245                                       sk == rtnl_dereference(mrt->mroute_sk));
1246                 } else {
1247                         ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1248                 }
1249                 rtnl_unlock();
1250                 return ret;
1251
1252                 /*
1253                  *      Manipulate the forwarding caches. These live
1254                  *      in a sort of kernel/user symbiosis.
1255                  */
1256         case MRT_ADD_MFC:
1257         case MRT_DEL_MFC:
1258                 if (optlen != sizeof(mfc))
1259                         return -EINVAL;
1260                 if (copy_from_user(&mfc, optval, sizeof(mfc)))
1261                         return -EFAULT;
1262                 rtnl_lock();
1263                 if (optname == MRT_DEL_MFC)
1264                         ret = ipmr_mfc_delete(mrt, &mfc);
1265                 else
1266                         ret = ipmr_mfc_add(net, mrt, &mfc,
1267                                            sk == rtnl_dereference(mrt->mroute_sk));
1268                 rtnl_unlock();
1269                 return ret;
1270                 /*
1271                  *      Control PIM assert.
1272                  */
1273         case MRT_ASSERT:
1274         {
1275                 int v;
1276                 if (get_user(v, (int __user *)optval))
1277                         return -EFAULT;
1278                 mrt->mroute_do_assert = (v) ? 1 : 0;
1279                 return 0;
1280         }
1281 #ifdef CONFIG_IP_PIMSM
1282         case MRT_PIM:
1283         {
1284                 int v;
1285
1286                 if (get_user(v, (int __user *)optval))
1287                         return -EFAULT;
1288                 v = (v) ? 1 : 0;
1289
1290                 rtnl_lock();
1291                 ret = 0;
1292                 if (v != mrt->mroute_do_pim) {
1293                         mrt->mroute_do_pim = v;
1294                         mrt->mroute_do_assert = v;
1295                 }
1296                 rtnl_unlock();
1297                 return ret;
1298         }
1299 #endif
1300 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
1301         case MRT_TABLE:
1302         {
1303                 u32 v;
1304
1305                 if (optlen != sizeof(u32))
1306                         return -EINVAL;
1307                 if (get_user(v, (u32 __user *)optval))
1308                         return -EFAULT;
1309
1310                 rtnl_lock();
1311                 ret = 0;
1312                 if (sk == rtnl_dereference(mrt->mroute_sk)) {
1313                         ret = -EBUSY;
1314                 } else {
1315                         if (!ipmr_new_table(net, v))
1316                                 ret = -ENOMEM;
1317                         raw_sk(sk)->ipmr_table = v;
1318                 }
1319                 rtnl_unlock();
1320                 return ret;
1321         }
1322 #endif
1323         /*
1324          *      Spurious command, or MRT_VERSION which you cannot
1325          *      set.
1326          */
1327         default:
1328                 return -ENOPROTOOPT;
1329         }
1330 }
1331
1332 /*
1333  *      Getsock opt support for the multicast routing system.
1334  */
1335
1336 int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1337 {
1338         int olr;
1339         int val;
1340         struct net *net = sock_net(sk);
1341         struct mr_table *mrt;
1342
1343         mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1344         if (mrt == NULL)
1345                 return -ENOENT;
1346
1347         if (optname != MRT_VERSION &&
1348 #ifdef CONFIG_IP_PIMSM
1349            optname != MRT_PIM &&
1350 #endif
1351            optname != MRT_ASSERT)
1352                 return -ENOPROTOOPT;
1353
1354         if (get_user(olr, optlen))
1355                 return -EFAULT;
1356
1357         olr = min_t(unsigned int, olr, sizeof(int));
1358         if (olr < 0)
1359                 return -EINVAL;
1360
1361         if (put_user(olr, optlen))
1362                 return -EFAULT;
1363         if (optname == MRT_VERSION)
1364                 val = 0x0305;
1365 #ifdef CONFIG_IP_PIMSM
1366         else if (optname == MRT_PIM)
1367                 val = mrt->mroute_do_pim;
1368 #endif
1369         else
1370                 val = mrt->mroute_do_assert;
1371         if (copy_to_user(optval, &val, olr))
1372                 return -EFAULT;
1373         return 0;
1374 }
1375
1376 /*
1377  *      The IP multicast ioctl support routines.
1378  */
1379
1380 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1381 {
1382         struct sioc_sg_req sr;
1383         struct sioc_vif_req vr;
1384         struct vif_device *vif;
1385         struct mfc_cache *c;
1386         struct net *net = sock_net(sk);
1387         struct mr_table *mrt;
1388
1389         mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1390         if (mrt == NULL)
1391                 return -ENOENT;
1392
1393         switch (cmd) {
1394         case SIOCGETVIFCNT:
1395                 if (copy_from_user(&vr, arg, sizeof(vr)))
1396                         return -EFAULT;
1397                 if (vr.vifi >= mrt->maxvif)
1398                         return -EINVAL;
1399                 read_lock(&mrt_lock);
1400                 vif = &mrt->vif_table[vr.vifi];
1401                 if (VIF_EXISTS(mrt, vr.vifi)) {
1402                         vr.icount = vif->pkt_in;
1403                         vr.ocount = vif->pkt_out;
1404                         vr.ibytes = vif->bytes_in;
1405                         vr.obytes = vif->bytes_out;
1406                         read_unlock(&mrt_lock);
1407
1408                         if (copy_to_user(arg, &vr, sizeof(vr)))
1409                                 return -EFAULT;
1410                         return 0;
1411                 }
1412                 read_unlock(&mrt_lock);
1413                 return -EADDRNOTAVAIL;
1414         case SIOCGETSGCNT:
1415                 if (copy_from_user(&sr, arg, sizeof(sr)))
1416                         return -EFAULT;
1417
1418                 rcu_read_lock();
1419                 c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1420                 if (c) {
1421                         sr.pktcnt = c->mfc_un.res.pkt;
1422                         sr.bytecnt = c->mfc_un.res.bytes;
1423                         sr.wrong_if = c->mfc_un.res.wrong_if;
1424                         rcu_read_unlock();
1425
1426                         if (copy_to_user(arg, &sr, sizeof(sr)))
1427                                 return -EFAULT;
1428                         return 0;
1429                 }
1430                 rcu_read_unlock();
1431                 return -EADDRNOTAVAIL;
1432         default:
1433                 return -ENOIOCTLCMD;
1434         }
1435 }
1436
1437
1438 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1439 {
1440         struct net_device *dev = ptr;
1441         struct net *net = dev_net(dev);
1442         struct mr_table *mrt;
1443         struct vif_device *v;
1444         int ct;
1445         LIST_HEAD(list);
1446
1447         if (event != NETDEV_UNREGISTER)
1448                 return NOTIFY_DONE;
1449
1450         ipmr_for_each_table(mrt, net) {
1451                 v = &mrt->vif_table[0];
1452                 for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1453                         if (v->dev == dev)
1454                                 vif_delete(mrt, ct, 1, &list);
1455                 }
1456         }
1457         unregister_netdevice_many(&list);
1458         return NOTIFY_DONE;
1459 }
1460
1461
1462 static struct notifier_block ip_mr_notifier = {
1463         .notifier_call = ipmr_device_event,
1464 };
1465
1466 /*
1467  *      Encapsulate a packet by attaching a valid IPIP header to it.
1468  *      This avoids tunnel drivers and other mess and gives us the speed so
1469  *      important for multicast video.
1470  */
1471
1472 static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr)
1473 {
1474         struct iphdr *iph;
1475         struct iphdr *old_iph = ip_hdr(skb);
1476
1477         skb_push(skb, sizeof(struct iphdr));
1478         skb->transport_header = skb->network_header;
1479         skb_reset_network_header(skb);
1480         iph = ip_hdr(skb);
1481
1482         iph->version    =       4;
1483         iph->tos        =       old_iph->tos;
1484         iph->ttl        =       old_iph->ttl;
1485         iph->frag_off   =       0;
1486         iph->daddr      =       daddr;
1487         iph->saddr      =       saddr;
1488         iph->protocol   =       IPPROTO_IPIP;
1489         iph->ihl        =       5;
1490         iph->tot_len    =       htons(skb->len);
1491         ip_select_ident(iph, skb_dst(skb), NULL);
1492         ip_send_check(iph);
1493
1494         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1495         nf_reset(skb);
1496 }
1497
1498 static inline int ipmr_forward_finish(struct sk_buff *skb)
1499 {
1500         struct ip_options *opt = &(IPCB(skb)->opt);
1501
1502         IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
1503
1504         if (unlikely(opt->optlen))
1505                 ip_forward_options(skb);
1506
1507         return dst_output(skb);
1508 }
1509
1510 /*
1511  *      Processing handlers for ipmr_forward
1512  */
1513
1514 static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1515                             struct sk_buff *skb, struct mfc_cache *c, int vifi)
1516 {
1517         const struct iphdr *iph = ip_hdr(skb);
1518         struct vif_device *vif = &mrt->vif_table[vifi];
1519         struct net_device *dev;
1520         struct rtable *rt;
1521         int    encap = 0;
1522
1523         if (vif->dev == NULL)
1524                 goto out_free;
1525
1526 #ifdef CONFIG_IP_PIMSM
1527         if (vif->flags & VIFF_REGISTER) {
1528                 vif->pkt_out++;
1529                 vif->bytes_out += skb->len;
1530                 vif->dev->stats.tx_bytes += skb->len;
1531                 vif->dev->stats.tx_packets++;
1532                 ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1533                 goto out_free;
1534         }
1535 #endif
1536
1537         if (vif->flags & VIFF_TUNNEL) {
1538                 struct flowi fl = {
1539                         .oif = vif->link,
1540                         .fl4_dst = vif->remote,
1541                         .fl4_src = vif->local,
1542                         .fl4_tos = RT_TOS(iph->tos),
1543                         .proto = IPPROTO_IPIP
1544                 };
1545
1546                 if (ip_route_output_key(net, &rt, &fl))
1547                         goto out_free;
1548                 encap = sizeof(struct iphdr);
1549         } else {
1550                 struct flowi fl = {
1551                         .oif = vif->link,
1552                         .fl4_dst = iph->daddr,
1553                         .fl4_tos = RT_TOS(iph->tos),
1554                         .proto = IPPROTO_IPIP
1555                 };
1556
1557                 if (ip_route_output_key(net, &rt, &fl))
1558                         goto out_free;
1559         }
1560
1561         dev = rt->dst.dev;
1562
1563         if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1564                 /* Do not fragment multicasts. Alas, IPv4 does not
1565                  * allow to send ICMP, so that packets will disappear
1566                  * to blackhole.
1567                  */
1568
1569                 IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
1570                 ip_rt_put(rt);
1571                 goto out_free;
1572         }
1573
1574         encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1575
1576         if (skb_cow(skb, encap)) {
1577                 ip_rt_put(rt);
1578                 goto out_free;
1579         }
1580
1581         vif->pkt_out++;
1582         vif->bytes_out += skb->len;
1583
1584         skb_dst_drop(skb);
1585         skb_dst_set(skb, &rt->dst);
1586         ip_decrease_ttl(ip_hdr(skb));
1587
1588         /* FIXME: forward and output firewalls used to be called here.
1589          * What do we do with netfilter? -- RR
1590          */
1591         if (vif->flags & VIFF_TUNNEL) {
1592                 ip_encap(skb, vif->local, vif->remote);
1593                 /* FIXME: extra output firewall step used to be here. --RR */
1594                 vif->dev->stats.tx_packets++;
1595                 vif->dev->stats.tx_bytes += skb->len;
1596         }
1597
1598         IPCB(skb)->flags |= IPSKB_FORWARDED;
1599
1600         /*
1601          * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1602          * not only before forwarding, but after forwarding on all output
1603          * interfaces. It is clear, if mrouter runs a multicasting
1604          * program, it should receive packets not depending to what interface
1605          * program is joined.
1606          * If we will not make it, the program will have to join on all
1607          * interfaces. On the other hand, multihoming host (or router, but
1608          * not mrouter) cannot join to more than one interface - it will
1609          * result in receiving multiple packets.
1610          */
1611         NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, skb, skb->dev, dev,
1612                 ipmr_forward_finish);
1613         return;
1614
1615 out_free:
1616         kfree_skb(skb);
1617 }
1618
1619 static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1620 {
1621         int ct;
1622
1623         for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1624                 if (mrt->vif_table[ct].dev == dev)
1625                         break;
1626         }
1627         return ct;
1628 }
1629
1630 /* "local" means that we should preserve one skb (for local delivery) */
1631
1632 static int ip_mr_forward(struct net *net, struct mr_table *mrt,
1633                          struct sk_buff *skb, struct mfc_cache *cache,
1634                          int local)
1635 {
1636         int psend = -1;
1637         int vif, ct;
1638
1639         vif = cache->mfc_parent;
1640         cache->mfc_un.res.pkt++;
1641         cache->mfc_un.res.bytes += skb->len;
1642
1643         /*
1644          * Wrong interface: drop packet and (maybe) send PIM assert.
1645          */
1646         if (mrt->vif_table[vif].dev != skb->dev) {
1647                 int true_vifi;
1648
1649                 if (rt_is_output_route(skb_rtable(skb))) {
1650                         /* It is our own packet, looped back.
1651                          * Very complicated situation...
1652                          *
1653                          * The best workaround until routing daemons will be
1654                          * fixed is not to redistribute packet, if it was
1655                          * send through wrong interface. It means, that
1656                          * multicast applications WILL NOT work for
1657                          * (S,G), which have default multicast route pointing
1658                          * to wrong oif. In any case, it is not a good
1659                          * idea to use multicasting applications on router.
1660                          */
1661                         goto dont_forward;
1662                 }
1663
1664                 cache->mfc_un.res.wrong_if++;
1665                 true_vifi = ipmr_find_vif(mrt, skb->dev);
1666
1667                 if (true_vifi >= 0 && mrt->mroute_do_assert &&
1668                     /* pimsm uses asserts, when switching from RPT to SPT,
1669                      * so that we cannot check that packet arrived on an oif.
1670                      * It is bad, but otherwise we would need to move pretty
1671                      * large chunk of pimd to kernel. Ough... --ANK
1672                      */
1673                     (mrt->mroute_do_pim ||
1674                      cache->mfc_un.res.ttls[true_vifi] < 255) &&
1675                     time_after(jiffies,
1676                                cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1677                         cache->mfc_un.res.last_assert = jiffies;
1678                         ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1679                 }
1680                 goto dont_forward;
1681         }
1682
1683         mrt->vif_table[vif].pkt_in++;
1684         mrt->vif_table[vif].bytes_in += skb->len;
1685
1686         /*
1687          *      Forward the frame
1688          */
1689         for (ct = cache->mfc_un.res.maxvif - 1;
1690              ct >= cache->mfc_un.res.minvif; ct--) {
1691                 if (ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1692                         if (psend != -1) {
1693                                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1694
1695                                 if (skb2)
1696                                         ipmr_queue_xmit(net, mrt, skb2, cache,
1697                                                         psend);
1698                         }
1699                         psend = ct;
1700                 }
1701         }
1702         if (psend != -1) {
1703                 if (local) {
1704                         struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1705
1706                         if (skb2)
1707                                 ipmr_queue_xmit(net, mrt, skb2, cache, psend);
1708                 } else {
1709                         ipmr_queue_xmit(net, mrt, skb, cache, psend);
1710                         return 0;
1711                 }
1712         }
1713
1714 dont_forward:
1715         if (!local)
1716                 kfree_skb(skb);
1717         return 0;
1718 }
1719
1720
1721 /*
1722  *      Multicast packets for forwarding arrive here
1723  *      Called with rcu_read_lock();
1724  */
1725
1726 int ip_mr_input(struct sk_buff *skb)
1727 {
1728         struct mfc_cache *cache;
1729         struct net *net = dev_net(skb->dev);
1730         int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
1731         struct mr_table *mrt;
1732         int err;
1733
1734         /* Packet is looped back after forward, it should not be
1735          * forwarded second time, but still can be delivered locally.
1736          */
1737         if (IPCB(skb)->flags & IPSKB_FORWARDED)
1738                 goto dont_forward;
1739
1740         err = ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt);
1741         if (err < 0) {
1742                 kfree_skb(skb);
1743                 return err;
1744         }
1745
1746         if (!local) {
1747                 if (IPCB(skb)->opt.router_alert) {
1748                         if (ip_call_ra_chain(skb))
1749                                 return 0;
1750                 } else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
1751                         /* IGMPv1 (and broken IGMPv2 implementations sort of
1752                          * Cisco IOS <= 11.2(8)) do not put router alert
1753                          * option to IGMP packets destined to routable
1754                          * groups. It is very bad, because it means
1755                          * that we can forward NO IGMP messages.
1756                          */
1757                         struct sock *mroute_sk;
1758
1759                         mroute_sk = rcu_dereference(mrt->mroute_sk);
1760                         if (mroute_sk) {
1761                                 nf_reset(skb);
1762                                 raw_rcv(mroute_sk, skb);
1763                                 return 0;
1764                         }
1765                     }
1766         }
1767
1768         /* already under rcu_read_lock() */
1769         cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
1770
1771         /*
1772          *      No usable cache entry
1773          */
1774         if (cache == NULL) {
1775                 int vif;
1776
1777                 if (local) {
1778                         struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1779                         ip_local_deliver(skb);
1780                         if (skb2 == NULL)
1781                                 return -ENOBUFS;
1782                         skb = skb2;
1783                 }
1784
1785                 read_lock(&mrt_lock);
1786                 vif = ipmr_find_vif(mrt, skb->dev);
1787                 if (vif >= 0) {
1788                         int err2 = ipmr_cache_unresolved(mrt, vif, skb);
1789                         read_unlock(&mrt_lock);
1790
1791                         return err2;
1792                 }
1793                 read_unlock(&mrt_lock);
1794                 kfree_skb(skb);
1795                 return -ENODEV;
1796         }
1797
1798         read_lock(&mrt_lock);
1799         ip_mr_forward(net, mrt, skb, cache, local);
1800         read_unlock(&mrt_lock);
1801
1802         if (local)
1803                 return ip_local_deliver(skb);
1804
1805         return 0;
1806
1807 dont_forward:
1808         if (local)
1809                 return ip_local_deliver(skb);
1810         kfree_skb(skb);
1811         return 0;
1812 }
1813
1814 #ifdef CONFIG_IP_PIMSM
1815 /* called with rcu_read_lock() */
1816 static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
1817                      unsigned int pimlen)
1818 {
1819         struct net_device *reg_dev = NULL;
1820         struct iphdr *encap;
1821
1822         encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
1823         /*
1824          * Check that:
1825          * a. packet is really sent to a multicast group
1826          * b. packet is not a NULL-REGISTER
1827          * c. packet is not truncated
1828          */
1829         if (!ipv4_is_multicast(encap->daddr) ||
1830             encap->tot_len == 0 ||
1831             ntohs(encap->tot_len) + pimlen > skb->len)
1832                 return 1;
1833
1834         read_lock(&mrt_lock);
1835         if (mrt->mroute_reg_vif_num >= 0)
1836                 reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
1837         read_unlock(&mrt_lock);
1838
1839         if (reg_dev == NULL)
1840                 return 1;
1841
1842         skb->mac_header = skb->network_header;
1843         skb_pull(skb, (u8 *)encap - skb->data);
1844         skb_reset_network_header(skb);
1845         skb->protocol = htons(ETH_P_IP);
1846         skb->ip_summed = CHECKSUM_NONE;
1847         skb->pkt_type = PACKET_HOST;
1848
1849         skb_tunnel_rx(skb, reg_dev);
1850
1851         netif_rx(skb);
1852
1853         return NET_RX_SUCCESS;
1854 }
1855 #endif
1856
1857 #ifdef CONFIG_IP_PIMSM_V1
1858 /*
1859  * Handle IGMP messages of PIMv1
1860  */
1861
1862 int pim_rcv_v1(struct sk_buff *skb)
1863 {
1864         struct igmphdr *pim;
1865         struct net *net = dev_net(skb->dev);
1866         struct mr_table *mrt;
1867
1868         if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
1869                 goto drop;
1870
1871         pim = igmp_hdr(skb);
1872
1873         if (ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt) < 0)
1874                 goto drop;
1875
1876         if (!mrt->mroute_do_pim ||
1877             pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
1878                 goto drop;
1879
1880         if (__pim_rcv(mrt, skb, sizeof(*pim))) {
1881 drop:
1882                 kfree_skb(skb);
1883         }
1884         return 0;
1885 }
1886 #endif
1887
1888 #ifdef CONFIG_IP_PIMSM_V2
1889 static int pim_rcv(struct sk_buff *skb)
1890 {
1891         struct pimreghdr *pim;
1892         struct net *net = dev_net(skb->dev);
1893         struct mr_table *mrt;
1894
1895         if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
1896                 goto drop;
1897
1898         pim = (struct pimreghdr *)skb_transport_header(skb);
1899         if (pim->type != ((PIM_VERSION << 4) | (PIM_REGISTER)) ||
1900             (pim->flags & PIM_NULL_REGISTER) ||
1901             (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
1902              csum_fold(skb_checksum(skb, 0, skb->len, 0))))
1903                 goto drop;
1904
1905         if (ipmr_fib_lookup(net, &skb_rtable(skb)->fl, &mrt) < 0)
1906                 goto drop;
1907
1908         if (__pim_rcv(mrt, skb, sizeof(*pim))) {
1909 drop:
1910                 kfree_skb(skb);
1911         }
1912         return 0;
1913 }
1914 #endif
1915
1916 static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
1917                               struct mfc_cache *c, struct rtmsg *rtm)
1918 {
1919         int ct;
1920         struct rtnexthop *nhp;
1921         u8 *b = skb_tail_pointer(skb);
1922         struct rtattr *mp_head;
1923
1924         /* If cache is unresolved, don't try to parse IIF and OIF */
1925         if (c->mfc_parent >= MAXVIFS)
1926                 return -ENOENT;
1927
1928         if (VIF_EXISTS(mrt, c->mfc_parent))
1929                 RTA_PUT(skb, RTA_IIF, 4, &mrt->vif_table[c->mfc_parent].dev->ifindex);
1930
1931         mp_head = (struct rtattr *)skb_put(skb, RTA_LENGTH(0));
1932
1933         for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
1934                 if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
1935                         if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
1936                                 goto rtattr_failure;
1937                         nhp = (struct rtnexthop *)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
1938                         nhp->rtnh_flags = 0;
1939                         nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
1940                         nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
1941                         nhp->rtnh_len = sizeof(*nhp);
1942                 }
1943         }
1944         mp_head->rta_type = RTA_MULTIPATH;
1945         mp_head->rta_len = skb_tail_pointer(skb) - (u8 *)mp_head;
1946         rtm->rtm_type = RTN_MULTICAST;
1947         return 1;
1948
1949 rtattr_failure:
1950         nlmsg_trim(skb, b);
1951         return -EMSGSIZE;
1952 }
1953
1954 int ipmr_get_route(struct net *net,
1955                    struct sk_buff *skb, struct rtmsg *rtm, int nowait)
1956 {
1957         int err;
1958         struct mr_table *mrt;
1959         struct mfc_cache *cache;
1960         struct rtable *rt = skb_rtable(skb);
1961
1962         mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
1963         if (mrt == NULL)
1964                 return -ENOENT;
1965
1966         rcu_read_lock();
1967         cache = ipmr_cache_find(mrt, rt->rt_src, rt->rt_dst);
1968
1969         if (cache == NULL) {
1970                 struct sk_buff *skb2;
1971                 struct iphdr *iph;
1972                 struct net_device *dev;
1973                 int vif = -1;
1974
1975                 if (nowait) {
1976                         rcu_read_unlock();
1977                         return -EAGAIN;
1978                 }
1979
1980                 dev = skb->dev;
1981                 read_lock(&mrt_lock);
1982                 if (dev)
1983                         vif = ipmr_find_vif(mrt, dev);
1984                 if (vif < 0) {
1985                         read_unlock(&mrt_lock);
1986                         rcu_read_unlock();
1987                         return -ENODEV;
1988                 }
1989                 skb2 = skb_clone(skb, GFP_ATOMIC);
1990                 if (!skb2) {
1991                         read_unlock(&mrt_lock);
1992                         rcu_read_unlock();
1993                         return -ENOMEM;
1994                 }
1995
1996                 skb_push(skb2, sizeof(struct iphdr));
1997                 skb_reset_network_header(skb2);
1998                 iph = ip_hdr(skb2);
1999                 iph->ihl = sizeof(struct iphdr) >> 2;
2000                 iph->saddr = rt->rt_src;
2001                 iph->daddr = rt->rt_dst;
2002                 iph->version = 0;
2003                 err = ipmr_cache_unresolved(mrt, vif, skb2);
2004                 read_unlock(&mrt_lock);
2005                 rcu_read_unlock();
2006                 return err;
2007         }
2008
2009         read_lock(&mrt_lock);
2010         if (!nowait && (rtm->rtm_flags & RTM_F_NOTIFY))
2011                 cache->mfc_flags |= MFC_NOTIFY;
2012         err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2013         read_unlock(&mrt_lock);
2014         rcu_read_unlock();
2015         return err;
2016 }
2017
2018 static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2019                             u32 pid, u32 seq, struct mfc_cache *c)
2020 {
2021         struct nlmsghdr *nlh;
2022         struct rtmsg *rtm;
2023
2024         nlh = nlmsg_put(skb, pid, seq, RTM_NEWROUTE, sizeof(*rtm), NLM_F_MULTI);
2025         if (nlh == NULL)
2026                 return -EMSGSIZE;
2027
2028         rtm = nlmsg_data(nlh);
2029         rtm->rtm_family   = RTNL_FAMILY_IPMR;
2030         rtm->rtm_dst_len  = 32;
2031         rtm->rtm_src_len  = 32;
2032         rtm->rtm_tos      = 0;
2033         rtm->rtm_table    = mrt->id;
2034         NLA_PUT_U32(skb, RTA_TABLE, mrt->id);
2035         rtm->rtm_type     = RTN_MULTICAST;
2036         rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2037         rtm->rtm_protocol = RTPROT_UNSPEC;
2038         rtm->rtm_flags    = 0;
2039
2040         NLA_PUT_BE32(skb, RTA_SRC, c->mfc_origin);
2041         NLA_PUT_BE32(skb, RTA_DST, c->mfc_mcastgrp);
2042
2043         if (__ipmr_fill_mroute(mrt, skb, c, rtm) < 0)
2044                 goto nla_put_failure;
2045
2046         return nlmsg_end(skb, nlh);
2047
2048 nla_put_failure:
2049         nlmsg_cancel(skb, nlh);
2050         return -EMSGSIZE;
2051 }
2052
2053 static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2054 {
2055         struct net *net = sock_net(skb->sk);
2056         struct mr_table *mrt;
2057         struct mfc_cache *mfc;
2058         unsigned int t = 0, s_t;
2059         unsigned int h = 0, s_h;
2060         unsigned int e = 0, s_e;
2061
2062         s_t = cb->args[0];
2063         s_h = cb->args[1];
2064         s_e = cb->args[2];
2065
2066         rcu_read_lock();
2067         ipmr_for_each_table(mrt, net) {
2068                 if (t < s_t)
2069                         goto next_table;
2070                 if (t > s_t)
2071                         s_h = 0;
2072                 for (h = s_h; h < MFC_LINES; h++) {
2073                         list_for_each_entry_rcu(mfc, &mrt->mfc_cache_array[h], list) {
2074                                 if (e < s_e)
2075                                         goto next_entry;
2076                                 if (ipmr_fill_mroute(mrt, skb,
2077                                                      NETLINK_CB(cb->skb).pid,
2078                                                      cb->nlh->nlmsg_seq,
2079                                                      mfc) < 0)
2080                                         goto done;
2081 next_entry:
2082                                 e++;
2083                         }
2084                         e = s_e = 0;
2085                 }
2086                 s_h = 0;
2087 next_table:
2088                 t++;
2089         }
2090 done:
2091         rcu_read_unlock();
2092
2093         cb->args[2] = e;
2094         cb->args[1] = h;
2095         cb->args[0] = t;
2096
2097         return skb->len;
2098 }
2099
2100 #ifdef CONFIG_PROC_FS
2101 /*
2102  *      The /proc interfaces to multicast routing :
2103  *      /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2104  */
2105 struct ipmr_vif_iter {
2106         struct seq_net_private p;
2107         struct mr_table *mrt;
2108         int ct;
2109 };
2110
2111 static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2112                                            struct ipmr_vif_iter *iter,
2113                                            loff_t pos)
2114 {
2115         struct mr_table *mrt = iter->mrt;
2116
2117         for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2118                 if (!VIF_EXISTS(mrt, iter->ct))
2119                         continue;
2120                 if (pos-- == 0)
2121                         return &mrt->vif_table[iter->ct];
2122         }
2123         return NULL;
2124 }
2125
2126 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2127         __acquires(mrt_lock)
2128 {
2129         struct ipmr_vif_iter *iter = seq->private;
2130         struct net *net = seq_file_net(seq);
2131         struct mr_table *mrt;
2132
2133         mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2134         if (mrt == NULL)
2135                 return ERR_PTR(-ENOENT);
2136
2137         iter->mrt = mrt;
2138
2139         read_lock(&mrt_lock);
2140         return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2141                 : SEQ_START_TOKEN;
2142 }
2143
2144 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2145 {
2146         struct ipmr_vif_iter *iter = seq->private;
2147         struct net *net = seq_file_net(seq);
2148         struct mr_table *mrt = iter->mrt;
2149
2150         ++*pos;
2151         if (v == SEQ_START_TOKEN)
2152                 return ipmr_vif_seq_idx(net, iter, 0);
2153
2154         while (++iter->ct < mrt->maxvif) {
2155                 if (!VIF_EXISTS(mrt, iter->ct))
2156                         continue;
2157                 return &mrt->vif_table[iter->ct];
2158         }
2159         return NULL;
2160 }
2161
2162 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2163         __releases(mrt_lock)
2164 {
2165         read_unlock(&mrt_lock);
2166 }
2167
2168 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2169 {
2170         struct ipmr_vif_iter *iter = seq->private;
2171         struct mr_table *mrt = iter->mrt;
2172
2173         if (v == SEQ_START_TOKEN) {
2174                 seq_puts(seq,
2175                          "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2176         } else {
2177                 const struct vif_device *vif = v;
2178                 const char *name =  vif->dev ? vif->dev->name : "none";
2179
2180                 seq_printf(seq,
2181                            "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2182                            vif - mrt->vif_table,
2183                            name, vif->bytes_in, vif->pkt_in,
2184                            vif->bytes_out, vif->pkt_out,
2185                            vif->flags, vif->local, vif->remote);
2186         }
2187         return 0;
2188 }
2189
2190 static const struct seq_operations ipmr_vif_seq_ops = {
2191         .start = ipmr_vif_seq_start,
2192         .next  = ipmr_vif_seq_next,
2193         .stop  = ipmr_vif_seq_stop,
2194         .show  = ipmr_vif_seq_show,
2195 };
2196
2197 static int ipmr_vif_open(struct inode *inode, struct file *file)
2198 {
2199         return seq_open_net(inode, file, &ipmr_vif_seq_ops,
2200                             sizeof(struct ipmr_vif_iter));
2201 }
2202
2203 static const struct file_operations ipmr_vif_fops = {
2204         .owner   = THIS_MODULE,
2205         .open    = ipmr_vif_open,
2206         .read    = seq_read,
2207         .llseek  = seq_lseek,
2208         .release = seq_release_net,
2209 };
2210
2211 struct ipmr_mfc_iter {
2212         struct seq_net_private p;
2213         struct mr_table *mrt;
2214         struct list_head *cache;
2215         int ct;
2216 };
2217
2218
2219 static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
2220                                           struct ipmr_mfc_iter *it, loff_t pos)
2221 {
2222         struct mr_table *mrt = it->mrt;
2223         struct mfc_cache *mfc;
2224
2225         rcu_read_lock();
2226         for (it->ct = 0; it->ct < MFC_LINES; it->ct++) {
2227                 it->cache = &mrt->mfc_cache_array[it->ct];
2228                 list_for_each_entry_rcu(mfc, it->cache, list)
2229                         if (pos-- == 0)
2230                                 return mfc;
2231         }
2232         rcu_read_unlock();
2233
2234         spin_lock_bh(&mfc_unres_lock);
2235         it->cache = &mrt->mfc_unres_queue;
2236         list_for_each_entry(mfc, it->cache, list)
2237                 if (pos-- == 0)
2238                         return mfc;
2239         spin_unlock_bh(&mfc_unres_lock);
2240
2241         it->cache = NULL;
2242         return NULL;
2243 }
2244
2245
2246 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2247 {
2248         struct ipmr_mfc_iter *it = seq->private;
2249         struct net *net = seq_file_net(seq);
2250         struct mr_table *mrt;
2251
2252         mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2253         if (mrt == NULL)
2254                 return ERR_PTR(-ENOENT);
2255
2256         it->mrt = mrt;
2257         it->cache = NULL;
2258         it->ct = 0;
2259         return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
2260                 : SEQ_START_TOKEN;
2261 }
2262
2263 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2264 {
2265         struct mfc_cache *mfc = v;
2266         struct ipmr_mfc_iter *it = seq->private;
2267         struct net *net = seq_file_net(seq);
2268         struct mr_table *mrt = it->mrt;
2269
2270         ++*pos;
2271
2272         if (v == SEQ_START_TOKEN)
2273                 return ipmr_mfc_seq_idx(net, seq->private, 0);
2274
2275         if (mfc->list.next != it->cache)
2276                 return list_entry(mfc->list.next, struct mfc_cache, list);
2277
2278         if (it->cache == &mrt->mfc_unres_queue)
2279                 goto end_of_list;
2280
2281         BUG_ON(it->cache != &mrt->mfc_cache_array[it->ct]);
2282
2283         while (++it->ct < MFC_LINES) {
2284                 it->cache = &mrt->mfc_cache_array[it->ct];
2285                 if (list_empty(it->cache))
2286                         continue;
2287                 return list_first_entry(it->cache, struct mfc_cache, list);
2288         }
2289
2290         /* exhausted cache_array, show unresolved */
2291         rcu_read_unlock();
2292         it->cache = &mrt->mfc_unres_queue;
2293         it->ct = 0;
2294
2295         spin_lock_bh(&mfc_unres_lock);
2296         if (!list_empty(it->cache))
2297                 return list_first_entry(it->cache, struct mfc_cache, list);
2298
2299 end_of_list:
2300         spin_unlock_bh(&mfc_unres_lock);
2301         it->cache = NULL;
2302
2303         return NULL;
2304 }
2305
2306 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
2307 {
2308         struct ipmr_mfc_iter *it = seq->private;
2309         struct mr_table *mrt = it->mrt;
2310
2311         if (it->cache == &mrt->mfc_unres_queue)
2312                 spin_unlock_bh(&mfc_unres_lock);
2313         else if (it->cache == &mrt->mfc_cache_array[it->ct])
2314                 rcu_read_unlock();
2315 }
2316
2317 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2318 {
2319         int n;
2320
2321         if (v == SEQ_START_TOKEN) {
2322                 seq_puts(seq,
2323                  "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2324         } else {
2325                 const struct mfc_cache *mfc = v;
2326                 const struct ipmr_mfc_iter *it = seq->private;
2327                 const struct mr_table *mrt = it->mrt;
2328
2329                 seq_printf(seq, "%08X %08X %-3hd",
2330                            (__force u32) mfc->mfc_mcastgrp,
2331                            (__force u32) mfc->mfc_origin,
2332                            mfc->mfc_parent);
2333
2334                 if (it->cache != &mrt->mfc_unres_queue) {
2335                         seq_printf(seq, " %8lu %8lu %8lu",
2336                                    mfc->mfc_un.res.pkt,
2337                                    mfc->mfc_un.res.bytes,
2338                                    mfc->mfc_un.res.wrong_if);
2339                         for (n = mfc->mfc_un.res.minvif;
2340                              n < mfc->mfc_un.res.maxvif; n++) {
2341                                 if (VIF_EXISTS(mrt, n) &&
2342                                     mfc->mfc_un.res.ttls[n] < 255)
2343                                         seq_printf(seq,
2344                                            " %2d:%-3d",
2345                                            n, mfc->mfc_un.res.ttls[n]);
2346                         }
2347                 } else {
2348                         /* unresolved mfc_caches don't contain
2349                          * pkt, bytes and wrong_if values
2350                          */
2351                         seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
2352                 }
2353                 seq_putc(seq, '\n');
2354         }
2355         return 0;
2356 }
2357
2358 static const struct seq_operations ipmr_mfc_seq_ops = {
2359         .start = ipmr_mfc_seq_start,
2360         .next  = ipmr_mfc_seq_next,
2361         .stop  = ipmr_mfc_seq_stop,
2362         .show  = ipmr_mfc_seq_show,
2363 };
2364
2365 static int ipmr_mfc_open(struct inode *inode, struct file *file)
2366 {
2367         return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
2368                             sizeof(struct ipmr_mfc_iter));
2369 }
2370
2371 static const struct file_operations ipmr_mfc_fops = {
2372         .owner   = THIS_MODULE,
2373         .open    = ipmr_mfc_open,
2374         .read    = seq_read,
2375         .llseek  = seq_lseek,
2376         .release = seq_release_net,
2377 };
2378 #endif
2379
2380 #ifdef CONFIG_IP_PIMSM_V2
2381 static const struct net_protocol pim_protocol = {
2382         .handler        =       pim_rcv,
2383         .netns_ok       =       1,
2384 };
2385 #endif
2386
2387
2388 /*
2389  *      Setup for IP multicast routing
2390  */
2391 static int __net_init ipmr_net_init(struct net *net)
2392 {
2393         int err;
2394
2395         err = ipmr_rules_init(net);
2396         if (err < 0)
2397                 goto fail;
2398
2399 #ifdef CONFIG_PROC_FS
2400         err = -ENOMEM;
2401         if (!proc_net_fops_create(net, "ip_mr_vif", 0, &ipmr_vif_fops))
2402                 goto proc_vif_fail;
2403         if (!proc_net_fops_create(net, "ip_mr_cache", 0, &ipmr_mfc_fops))
2404                 goto proc_cache_fail;
2405 #endif
2406         return 0;
2407
2408 #ifdef CONFIG_PROC_FS
2409 proc_cache_fail:
2410         proc_net_remove(net, "ip_mr_vif");
2411 proc_vif_fail:
2412         ipmr_rules_exit(net);
2413 #endif
2414 fail:
2415         return err;
2416 }
2417
2418 static void __net_exit ipmr_net_exit(struct net *net)
2419 {
2420 #ifdef CONFIG_PROC_FS
2421         proc_net_remove(net, "ip_mr_cache");
2422         proc_net_remove(net, "ip_mr_vif");
2423 #endif
2424         ipmr_rules_exit(net);
2425 }
2426
2427 static struct pernet_operations ipmr_net_ops = {
2428         .init = ipmr_net_init,
2429         .exit = ipmr_net_exit,
2430 };
2431
2432 int __init ip_mr_init(void)
2433 {
2434         int err;
2435
2436         mrt_cachep = kmem_cache_create("ip_mrt_cache",
2437                                        sizeof(struct mfc_cache),
2438                                        0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
2439                                        NULL);
2440         if (!mrt_cachep)
2441                 return -ENOMEM;
2442
2443         err = register_pernet_subsys(&ipmr_net_ops);
2444         if (err)
2445                 goto reg_pernet_fail;
2446
2447         err = register_netdevice_notifier(&ip_mr_notifier);
2448         if (err)
2449                 goto reg_notif_fail;
2450 #ifdef CONFIG_IP_PIMSM_V2
2451         if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
2452                 printk(KERN_ERR "ip_mr_init: can't add PIM protocol\n");
2453                 err = -EAGAIN;
2454                 goto add_proto_fail;
2455         }
2456 #endif
2457         rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE, NULL, ipmr_rtm_dumproute);
2458         return 0;
2459
2460 #ifdef CONFIG_IP_PIMSM_V2
2461 add_proto_fail:
2462         unregister_netdevice_notifier(&ip_mr_notifier);
2463 #endif
2464 reg_notif_fail:
2465         unregister_pernet_subsys(&ipmr_net_ops);
2466 reg_pernet_fail:
2467         kmem_cache_destroy(mrt_cachep);
2468         return err;
2469 }