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   1 /*
   2  *      IP multicast routing support for mrouted 3.6/3.8
   3  *
   4  *              (c) 1995 Alan Cox, <alan@redhat.com>
   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  *      Version: $Id: ipmr.c,v 1.65 2001/10/31 21:55:54 davem Exp $
  13  *
  14  *      Fixes:
  15  *      Michael Chastain        :       Incorrect size of copying.
  16  *      Alan Cox                :       Added the cache manager code
  17  *      Alan Cox                :       Fixed the clone/copy bug and device race.
  18  *      Mike McLagan            :       Routing by source
  19  *      Malcolm Beattie         :       Buffer handling fixes.
  20  *      Alexey Kuznetsov        :       Double buffer free and other fixes.
  21  *      SVR Anand               :       Fixed several multicast bugs and problems.
  22  *      Alexey Kuznetsov        :       Status, optimisations and more.
  23  *      Brad Parker             :       Better behaviour on mrouted upcall
  24  *                                      overflow.
  25  *      Carlos Picoto           :       PIMv1 Support
  26  *      Pavlin Ivanov Radoslavov:       PIMv2 Registers must checksum only PIM header
  27  *                                      Relax this requrement to work with older peers.
  28  *
  29  */
  30
  31 #include <linux/config.h>
  32 #include <asm/system.h>
  33 #include <asm/uaccess.h>
  34 #include <linux/types.h>
  35 #include <linux/sched.h>
  36 #include <linux/errno.h>
  37 #include <linux/timer.h>
  38 #include <linux/mm.h>
  39 #include <linux/kernel.h>
  40 #include <linux/fcntl.h>
  41 #include <linux/stat.h>
  42 #include <linux/socket.h>
  43 #include <linux/in.h>
  44 #include <linux/inet.h>
  45 #include <linux/netdevice.h>
  46 #include <linux/inetdevice.h>
  47 #include <linux/igmp.h>
  48 #include <linux/proc_fs.h>
  49 #include <linux/seq_file.h>
  50 #include <linux/mroute.h>
  51 #include <linux/init.h>
  52 #include <net/ip.h>
  53 #include <net/protocol.h>
  54 #include <linux/skbuff.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 <net/ipip.h>
  63 #include <net/checksum.h>
  64
  65 #if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
  66 #define CONFIG_IP_PIMSM 1
  67 #endif
  68
  69 static struct sock *mroute_socket;
  70
  71
  72 /* Big lock, protecting vif table, mrt cache and mroute socket state.
  73    Note that the changes are semaphored via rtnl_lock.
  74  */
  75
  76 static DEFINE_RWLOCK(mrt_lock);
  77
  78 /*
  79  *      Multicast router control variables
  80  */
  81
  82 static struct vif_device vif_table[MAXVIFS];            /* Devices              */
  83 static int maxvif;
  84
  85 #define VIF_EXISTS(idx) (vif_table[idx].dev != NULL)
  86
  87 static int mroute_do_assert;                            /* Set in PIM assert    */
  88 static int mroute_do_pim;
  89
  90 static struct mfc_cache *mfc_cache_array[MFC_LINES];    /* Forwarding cache     */
  91
  92 static struct mfc_cache *mfc_unres_queue;               /* Queue of unresolved entries */
  93 static atomic_t cache_resolve_queue_len;                /* Size of unresolved   */
  94
  95 /* Special spinlock for queue of unresolved entries */
  96 static DEFINE_SPINLOCK(mfc_unres_lock);
  97
  98 /* We return to original Alan's scheme. Hash table of resolved
  99    entries is changed only in process context and protected
 100    with weak lock mrt_lock. Queue of unresolved entries is protected
 101    with strong spinlock mfc_unres_lock.
 102
 103    In this case data path is free of exclusive locks at all.
 104  */
 105
 106 static kmem_cache_t *mrt_cachep;
 107
 108 static int ip_mr_forward(struct sk_buff *skb, struct mfc_cache *cache, int local);
 109 static int ipmr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert);
 110 static int ipmr_fill_mroute(struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm);
 111
 112 #ifdef CONFIG_IP_PIMSM_V2
 113 static struct net_protocol pim_protocol;
 114 #endif
 115
 116 static struct timer_list ipmr_expire_timer;
 117
 118 /* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
 119
 120 static
 121 struct net_device *ipmr_new_tunnel(struct vifctl *v)
 122 {
 123         struct net_device  *dev;
 124
 125         dev = __dev_get_by_name("tunl0");
 126
 127         if (dev) {
 128                 int err;
 129                 struct ifreq ifr;
 130                 mm_segment_t    oldfs;
 131                 struct ip_tunnel_parm p;
 132                 struct in_device  *in_dev;
 133
 134                 memset(&p, 0, sizeof(p));
 135                 p.iph.daddr = v->vifc_rmt_addr.s_addr;
 136                 p.iph.saddr = v->vifc_lcl_addr.s_addr;
 137                 p.iph.version = 4;
 138                 p.iph.ihl = 5;
 139                 p.iph.protocol = IPPROTO_IPIP;
 140                 sprintf(p.name, "dvmrp%d", v->vifc_vifi);
 141                 ifr.ifr_ifru.ifru_data = (void*)&p;
 142
 143                 oldfs = get_fs(); set_fs(KERNEL_DS);
 144                 err = dev->do_ioctl(dev, &ifr, SIOCADDTUNNEL);
 145                 set_fs(oldfs);
 146
 147                 dev = NULL;
 148
 149                 if (err == 0 && (dev = __dev_get_by_name(p.name)) != NULL) {
 150                         dev->flags |= IFF_MULTICAST;
 151
 152                         in_dev = __in_dev_get(dev);
 153                         if (in_dev == NULL && (in_dev = inetdev_init(dev)) == NULL)
 154                                 goto failure;
 155                         in_dev->cnf.rp_filter = 0;
 156
 157                         if (dev_open(dev))
 158                                 goto failure;
 159                 }
 160         }
 161         return dev;
 162
 163 failure:
 164         /* allow the register to be completed before unregistering. */
 165         rtnl_unlock();
 166         rtnl_lock();
 167
 168         unregister_netdevice(dev);
 169         return NULL;
 170 }
 171
 172 #ifdef CONFIG_IP_PIMSM
 173
 174 static int reg_vif_num = -1;
 175
 176 static int reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
 177 {
 178         read_lock(&mrt_lock);
 179         ((struct net_device_stats*)dev->priv)->tx_bytes += skb->len;
 180         ((struct net_device_stats*)dev->priv)->tx_packets++;
 181         ipmr_cache_report(skb, reg_vif_num, IGMPMSG_WHOLEPKT);
 182         read_unlock(&mrt_lock);
 183         kfree_skb(skb);
 184         return 0;
 185 }
 186
 187 static struct net_device_stats *reg_vif_get_stats(struct net_device *dev)
 188 {
 189         return (struct net_device_stats*)dev->priv;
 190 }
 191
 192 static void reg_vif_setup(struct net_device *dev)
 193 {
 194         dev->type               = ARPHRD_PIMREG;
 195         dev->mtu                = 1500 - sizeof(struct iphdr) - 8;
 196         dev->flags              = IFF_NOARP;
 197         dev->hard_start_xmit    = reg_vif_xmit;
 198         dev->get_stats          = reg_vif_get_stats;
 199         dev->destructor         = free_netdev;
 200 }
 201
 202 static struct net_device *ipmr_reg_vif(void)
 203 {
 204         struct net_device *dev;
 205         struct in_device *in_dev;
 206
 207         dev = alloc_netdev(sizeof(struct net_device_stats), "pimreg",
 208                            reg_vif_setup);
 209
 210         if (dev == NULL)
 211                 return NULL;
 212
 213         if (register_netdevice(dev)) {
 214                 free_netdev(dev);
 215                 return NULL;
 216         }
 217         dev->iflink = 0;
 218
 219         if ((in_dev = inetdev_init(dev)) == NULL)
 220                 goto failure;
 221
 222         in_dev->cnf.rp_filter = 0;
 223
 224         if (dev_open(dev))
 225                 goto failure;
 226
 227         return dev;
 228
 229 failure:
 230         /* allow the register to be completed before unregistering. */
 231         rtnl_unlock();
 232         rtnl_lock();
 233
 234         unregister_netdevice(dev);
 235         return NULL;
 236 }
 237 #endif
 238
 239 /*
 240  *      Delete a VIF entry
 241  */
 242
 243 static int vif_delete(int vifi)
 244 {
 245         struct vif_device *v;
 246         struct net_device *dev;
 247         struct in_device *in_dev;
 248
 249         if (vifi < 0 || vifi >= maxvif)
 250                 return -EADDRNOTAVAIL;
 251
 252         v = &vif_table[vifi];
 253
 254         write_lock_bh(&mrt_lock);
 255         dev = v->dev;
 256         v->dev = NULL;
 257
 258         if (!dev) {
 259                 write_unlock_bh(&mrt_lock);
 260                 return -EADDRNOTAVAIL;
 261         }
 262
 263 #ifdef CONFIG_IP_PIMSM
 264         if (vifi == reg_vif_num)
 265                 reg_vif_num = -1;
 266 #endif
 267
 268         if (vifi+1 == maxvif) {
 269                 int tmp;
 270                 for (tmp=vifi-1; tmp>=0; tmp--) {
 271                         if (VIF_EXISTS(tmp))
 272                                 break;
 273                 }
 274                 maxvif = tmp+1;
 275         }
 276
 277         write_unlock_bh(&mrt_lock);
 278
 279         dev_set_allmulti(dev, -1);
 280
 281         if ((in_dev = __in_dev_get(dev)) != NULL) {
 282                 in_dev->cnf.mc_forwarding--;
 283                 ip_rt_multicast_event(in_dev);
 284         }
 285
 286         if (v->flags&(VIFF_TUNNEL|VIFF_REGISTER))
 287                 unregister_netdevice(dev);
 288
 289         dev_put(dev);
 290         return 0;
 291 }
 292
 293 /* Destroy an unresolved cache entry, killing queued skbs
 294    and reporting error to netlink readers.
 295  */
 296
 297 static void ipmr_destroy_unres(struct mfc_cache *c)
 298 {
 299         struct sk_buff *skb;
 300         struct nlmsgerr *e;
 301
 302         atomic_dec(&cache_resolve_queue_len);
 303
 304         while((skb=skb_dequeue(&c->mfc_un.unres.unresolved))) {
 305                 if (skb->nh.iph->version == 0) {
 306                         struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
 307                         nlh->nlmsg_type = NLMSG_ERROR;
 308                         nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
 309                         skb_trim(skb, nlh->nlmsg_len);
 310                         e = NLMSG_DATA(nlh);
 311                         e->error = -ETIMEDOUT;
 312                         memset(&e->msg, 0, sizeof(e->msg));
 313                         netlink_unicast(rtnl, skb, NETLINK_CB(skb).dst_pid, MSG_DONTWAIT);
 314                 } else
 315                         kfree_skb(skb);
 316         }
 317
 318         kmem_cache_free(mrt_cachep, c);
 319 }
 320
 321
 322 /* Single timer process for all the unresolved queue. */
 323
 324 static void ipmr_expire_process(unsigned long dummy)
 325 {
 326         unsigned long now;
 327         unsigned long expires;
 328         struct mfc_cache *c, **cp;
 329
 330         if (!spin_trylock(&mfc_unres_lock)) {
 331                 mod_timer(&ipmr_expire_timer, jiffies+HZ/10);
 332                 return;
 333         }
 334
 335         if (atomic_read(&cache_resolve_queue_len) == 0)
 336                 goto out;
 337
 338         now = jiffies;
 339         expires = 10*HZ;
 340         cp = &mfc_unres_queue;
 341
 342         while ((c=*cp) != NULL) {
 343                 if (time_after(c->mfc_un.unres.expires, now)) {
 344                         unsigned long interval = c->mfc_un.unres.expires - now;
 345                         if (interval < expires)
 346                                 expires = interval;
 347                         cp = &c->next;
 348                         continue;
 349                 }
 350
 351                 *cp = c->next;
 352
 353                 ipmr_destroy_unres(c);
 354         }
 355
 356         if (atomic_read(&cache_resolve_queue_len))
 357                 mod_timer(&ipmr_expire_timer, jiffies + expires);
 358
 359 out:
 360         spin_unlock(&mfc_unres_lock);
 361 }
 362
 363 /* Fill oifs list. It is called under write locked mrt_lock. */
 364
 365 static void ipmr_update_thresholds(struct mfc_cache *cache, unsigned char *ttls)
 366 {
 367         int vifi;
 368
 369         cache->mfc_un.res.minvif = MAXVIFS;
 370         cache->mfc_un.res.maxvif = 0;
 371         memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
 372
 373         for (vifi=0; vifi<maxvif; vifi++) {
 374                 if (VIF_EXISTS(vifi) && ttls[vifi] && ttls[vifi] < 255) {
 375                         cache->mfc_un.res.ttls[vifi] = ttls[vifi];
 376                         if (cache->mfc_un.res.minvif > vifi)
 377                                 cache->mfc_un.res.minvif = vifi;
 378                         if (cache->mfc_un.res.maxvif <= vifi)
 379                                 cache->mfc_un.res.maxvif = vifi + 1;
 380                 }
 381         }
 382 }
 383
 384 static int vif_add(struct vifctl *vifc, int mrtsock)
 385 {
 386         int vifi = vifc->vifc_vifi;
 387         struct vif_device *v = &vif_table[vifi];
 388         struct net_device *dev;
 389         struct in_device *in_dev;
 390
 391         /* Is vif busy ? */
 392         if (VIF_EXISTS(vifi))
 393                 return -EADDRINUSE;
 394
 395         switch (vifc->vifc_flags) {
 396 #ifdef CONFIG_IP_PIMSM
 397         case VIFF_REGISTER:
 398                 /*
 399                  * Special Purpose VIF in PIM
 400                  * All the packets will be sent to the daemon
 401                  */
 402                 if (reg_vif_num >= 0)
 403                         return -EADDRINUSE;
 404                 dev = ipmr_reg_vif();
 405                 if (!dev)
 406                         return -ENOBUFS;
 407                 break;
 408 #endif
 409         case VIFF_TUNNEL:
 410                 dev = ipmr_new_tunnel(vifc);
 411                 if (!dev)
 412                         return -ENOBUFS;
 413                 break;
 414         case 0:
 415                 dev=ip_dev_find(vifc->vifc_lcl_addr.s_addr);
 416                 if (!dev)
 417                         return -EADDRNOTAVAIL;
 418                 __dev_put(dev);
 419                 break;
 420         default:
 421                 return -EINVAL;
 422         }
 423
 424         if ((in_dev = __in_dev_get(dev)) == NULL)
 425                 return -EADDRNOTAVAIL;
 426         in_dev->cnf.mc_forwarding++;
 427         dev_set_allmulti(dev, +1);
 428         ip_rt_multicast_event(in_dev);
 429
 430         /*
 431          *      Fill in the VIF structures
 432          */
 433         v->rate_limit=vifc->vifc_rate_limit;
 434         v->local=vifc->vifc_lcl_addr.s_addr;
 435         v->remote=vifc->vifc_rmt_addr.s_addr;
 436         v->flags=vifc->vifc_flags;
 437         if (!mrtsock)
 438                 v->flags |= VIFF_STATIC;
 439         v->threshold=vifc->vifc_threshold;
 440         v->bytes_in = 0;
 441         v->bytes_out = 0;
 442         v->pkt_in = 0;
 443         v->pkt_out = 0;
 444         v->link = dev->ifindex;
 445         if (v->flags&(VIFF_TUNNEL|VIFF_REGISTER))
 446                 v->link = dev->iflink;
 447
 448         /* And finish update writing critical data */
 449         write_lock_bh(&mrt_lock);
 450         dev_hold(dev);
 451         v->dev=dev;
 452 #ifdef CONFIG_IP_PIMSM
 453         if (v->flags&VIFF_REGISTER)
 454                 reg_vif_num = vifi;
 455 #endif
 456         if (vifi+1 > maxvif)
 457                 maxvif = vifi+1;
 458         write_unlock_bh(&mrt_lock);
 459         return 0;
 460 }
 461
 462 static struct mfc_cache *ipmr_cache_find(__u32 origin, __u32 mcastgrp)
 463 {
 464         int line=MFC_HASH(mcastgrp,origin);
 465         struct mfc_cache *c;
 466
 467         for (c=mfc_cache_array[line]; c; c = c->next) {
 468                 if (c->mfc_origin==origin && c->mfc_mcastgrp==mcastgrp)
 469                         break;
 470         }
 471         return c;
 472 }
 473
 474 /*
 475  *      Allocate a multicast cache entry
 476  */
 477 static struct mfc_cache *ipmr_cache_alloc(void)
 478 {
 479         struct mfc_cache *c=kmem_cache_alloc(mrt_cachep, GFP_KERNEL);
 480         if(c==NULL)
 481                 return NULL;
 482         memset(c, 0, sizeof(*c));
 483         c->mfc_un.res.minvif = MAXVIFS;
 484         return c;
 485 }
 486
 487 static struct mfc_cache *ipmr_cache_alloc_unres(void)
 488 {
 489         struct mfc_cache *c=kmem_cache_alloc(mrt_cachep, GFP_ATOMIC);
 490         if(c==NULL)
 491                 return NULL;
 492         memset(c, 0, sizeof(*c));
 493         skb_queue_head_init(&c->mfc_un.unres.unresolved);
 494         c->mfc_un.unres.expires = jiffies + 10*HZ;
 495         return c;
 496 }
 497
 498 /*
 499  *      A cache entry has gone into a resolved state from queued
 500  */
 501
 502 static void ipmr_cache_resolve(struct mfc_cache *uc, struct mfc_cache *c)
 503 {
 504         struct sk_buff *skb;
 505         struct nlmsgerr *e;
 506
 507         /*
 508          *      Play the pending entries through our router
 509          */
 510
 511         while((skb=__skb_dequeue(&uc->mfc_un.unres.unresolved))) {
 512                 if (skb->nh.iph->version == 0) {
 513                         int err;
 514                         struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
 515
 516                         if (ipmr_fill_mroute(skb, c, NLMSG_DATA(nlh)) > 0) {
 517                                 nlh->nlmsg_len = skb->tail - (u8*)nlh;
 518                         } else {
 519                                 nlh->nlmsg_type = NLMSG_ERROR;
 520                                 nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
 521                                 skb_trim(skb, nlh->nlmsg_len);
 522                                 e = NLMSG_DATA(nlh);
 523                                 e->error = -EMSGSIZE;
 524                                 memset(&e->msg, 0, sizeof(e->msg));
 525                         }
 526                         err = netlink_unicast(rtnl, skb, NETLINK_CB(skb).dst_pid, MSG_DONTWAIT);
 527                 } else
 528                         ip_mr_forward(skb, c, 0);
 529         }
 530 }
 531
 532 /*
 533  *      Bounce a cache query up to mrouted. We could use netlink for this but mrouted
 534  *      expects the following bizarre scheme.
 535  *
 536  *      Called under mrt_lock.
 537  */
 538
 539 static int ipmr_cache_report(struct sk_buff *pkt, vifi_t vifi, int assert)
 540 {
 541         struct sk_buff *skb;
 542         int ihl = pkt->nh.iph->ihl<<2;
 543         struct igmphdr *igmp;
 544         struct igmpmsg *msg;
 545         int ret;
 546
 547 #ifdef CONFIG_IP_PIMSM
 548         if (assert == IGMPMSG_WHOLEPKT)
 549                 skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
 550         else
 551 #endif
 552                 skb = alloc_skb(128, GFP_ATOMIC);
 553
 554         if(!skb)
 555                 return -ENOBUFS;
 556
 557 #ifdef CONFIG_IP_PIMSM
 558         if (assert == IGMPMSG_WHOLEPKT) {
 559                 /* Ugly, but we have no choice with this interface.
 560                    Duplicate old header, fix ihl, length etc.
 561                    And all this only to mangle msg->im_msgtype and
 562                    to set msg->im_mbz to "mbz" :-)
 563                  */
 564                 msg = (struct igmpmsg*)skb_push(skb, sizeof(struct iphdr));
 565                 skb->nh.raw = skb->h.raw = (u8*)msg;
 566                 memcpy(msg, pkt->nh.raw, sizeof(struct iphdr));
 567                 msg->im_msgtype = IGMPMSG_WHOLEPKT;
 568                 msg->im_mbz = 0;
 569                 msg->im_vif = reg_vif_num;
 570                 skb->nh.iph->ihl = sizeof(struct iphdr) >> 2;
 571                 skb->nh.iph->tot_len = htons(ntohs(pkt->nh.iph->tot_len) + sizeof(struct iphdr));
 572         } else
 573 #endif
 574         {
 575
 576         /*
 577          *      Copy the IP header
 578          */
 579
 580         skb->nh.iph = (struct iphdr *)skb_put(skb, ihl);
 581         memcpy(skb->data,pkt->data,ihl);
 582         skb->nh.iph->protocol = 0;                      /* Flag to the kernel this is a route add */
 583         msg = (struct igmpmsg*)skb->nh.iph;
 584         msg->im_vif = vifi;
 585         skb->dst = dst_clone(pkt->dst);
 586
 587         /*
 588          *      Add our header
 589          */
 590
 591         igmp=(struct igmphdr *)skb_put(skb,sizeof(struct igmphdr));
 592         igmp->type      =
 593         msg->im_msgtype = assert;
 594         igmp->code      =       0;
 595         skb->nh.iph->tot_len=htons(skb->len);                   /* Fix the length */
 596         skb->h.raw = skb->nh.raw;
 597         }
 598
 599         if (mroute_socket == NULL) {
 600                 kfree_skb(skb);
 601                 return -EINVAL;
 602         }
 603
 604         /*
 605          *      Deliver to mrouted
 606          */
 607         if ((ret=sock_queue_rcv_skb(mroute_socket,skb))<0) {
 608                 if (net_ratelimit())
 609                         printk(KERN_WARNING "mroute: pending queue full, dropping entries.\n");
 610                 kfree_skb(skb);
 611         }
 612
 613         return ret;
 614 }
 615
 616 /*
 617  *      Queue a packet for resolution. It gets locked cache entry!
 618  */
 619
 620 static int
 621 ipmr_cache_unresolved(vifi_t vifi, struct sk_buff *skb)
 622 {
 623         int err;
 624         struct mfc_cache *c;
 625
 626         spin_lock_bh(&mfc_unres_lock);
 627         for (c=mfc_unres_queue; c; c=c->next) {
 628                 if (c->mfc_mcastgrp == skb->nh.iph->daddr &&
 629                     c->mfc_origin == skb->nh.iph->saddr)
 630                         break;
 631         }
 632
 633         if (c == NULL) {
 634                 /*
 635                  *      Create a new entry if allowable
 636                  */
 637
 638                 if (atomic_read(&cache_resolve_queue_len)>=10 ||
 639                     (c=ipmr_cache_alloc_unres())==NULL) {
 640                         spin_unlock_bh(&mfc_unres_lock);
 641
 642                         kfree_skb(skb);
 643                         return -ENOBUFS;
 644                 }
 645
 646                 /*
 647                  *      Fill in the new cache entry
 648                  */
 649                 c->mfc_parent=-1;
 650                 c->mfc_origin=skb->nh.iph->saddr;
 651                 c->mfc_mcastgrp=skb->nh.iph->daddr;
 652
 653                 /*
 654                  *      Reflect first query at mrouted.
 655                  */
 656                 if ((err = ipmr_cache_report(skb, vifi, IGMPMSG_NOCACHE))<0) {
 657                         /* If the report failed throw the cache entry
 658                            out - Brad Parker
 659                          */
 660                         spin_unlock_bh(&mfc_unres_lock);
 661
 662                         kmem_cache_free(mrt_cachep, c);
 663                         kfree_skb(skb);
 664                         return err;
 665                 }
 666
 667                 atomic_inc(&cache_resolve_queue_len);
 668                 c->next = mfc_unres_queue;
 669                 mfc_unres_queue = c;
 670
 671                 mod_timer(&ipmr_expire_timer, c->mfc_un.unres.expires);
 672         }
 673
 674         /*
 675          *      See if we can append the packet
 676          */
 677         if (c->mfc_un.unres.unresolved.qlen>3) {
 678                 kfree_skb(skb);
 679                 err = -ENOBUFS;
 680         } else {
 681                 skb_queue_tail(&c->mfc_un.unres.unresolved,skb);
 682                 err = 0;
 683         }
 684
 685         spin_unlock_bh(&mfc_unres_lock);
 686         return err;
 687 }
 688
 689 /*
 690  *      MFC cache manipulation by user space mroute daemon
 691  */
 692
 693 static int ipmr_mfc_delete(struct mfcctl *mfc)
 694 {
 695         int line;
 696         struct mfc_cache *c, **cp;
 697
 698         line=MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
 699
 700         for (cp=&mfc_cache_array[line]; (c=*cp) != NULL; cp = &c->next) {
 701                 if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
 702                     c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
 703                         write_lock_bh(&mrt_lock);
 704                         *cp = c->next;
 705                         write_unlock_bh(&mrt_lock);
 706
 707                         kmem_cache_free(mrt_cachep, c);
 708                         return 0;
 709                 }
 710         }
 711         return -ENOENT;
 712 }
 713
 714 static int ipmr_mfc_add(struct mfcctl *mfc, int mrtsock)
 715 {
 716         int line;
 717         struct mfc_cache *uc, *c, **cp;
 718
 719         line=MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
 720
 721         for (cp=&mfc_cache_array[line]; (c=*cp) != NULL; cp = &c->next) {
 722                 if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
 723                     c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr)
 724                         break;
 725         }
 726
 727         if (c != NULL) {
 728                 write_lock_bh(&mrt_lock);
 729                 c->mfc_parent = mfc->mfcc_parent;
 730                 ipmr_update_thresholds(c, mfc->mfcc_ttls);
 731                 if (!mrtsock)
 732                         c->mfc_flags |= MFC_STATIC;
 733                 write_unlock_bh(&mrt_lock);
 734                 return 0;
 735         }
 736
 737         if(!MULTICAST(mfc->mfcc_mcastgrp.s_addr))
 738                 return -EINVAL;
 739
 740         c=ipmr_cache_alloc();
 741         if (c==NULL)
 742                 return -ENOMEM;
 743
 744         c->mfc_origin=mfc->mfcc_origin.s_addr;
 745         c->mfc_mcastgrp=mfc->mfcc_mcastgrp.s_addr;
 746         c->mfc_parent=mfc->mfcc_parent;
 747         ipmr_update_thresholds(c, mfc->mfcc_ttls);
 748         if (!mrtsock)
 749                 c->mfc_flags |= MFC_STATIC;
 750
 751         write_lock_bh(&mrt_lock);
 752         c->next = mfc_cache_array[line];
 753         mfc_cache_array[line] = c;
 754         write_unlock_bh(&mrt_lock);
 755
 756         /*
 757          *      Check to see if we resolved a queued list. If so we
 758          *      need to send on the frames and tidy up.
 759          */
 760         spin_lock_bh(&mfc_unres_lock);
 761         for (cp = &mfc_unres_queue; (uc=*cp) != NULL;
 762              cp = &uc->next) {
 763                 if (uc->mfc_origin == c->mfc_origin &&
 764                     uc->mfc_mcastgrp == c->mfc_mcastgrp) {
 765                         *cp = uc->next;
 766                         if (atomic_dec_and_test(&cache_resolve_queue_len))
 767                                 del_timer(&ipmr_expire_timer);
 768                         break;
 769                 }
 770         }
 771         spin_unlock_bh(&mfc_unres_lock);
 772
 773         if (uc) {
 774                 ipmr_cache_resolve(uc, c);
 775                 kmem_cache_free(mrt_cachep, uc);
 776         }
 777         return 0;
 778 }
 779
 780 /*
 781  *      Close the multicast socket, and clear the vif tables etc
 782  */
 783
 784 static void mroute_clean_tables(struct sock *sk)
 785 {
 786         int i;
 787
 788         /*
 789          *      Shut down all active vif entries
 790          */
 791         for(i=0; i<maxvif; i++) {
 792                 if (!(vif_table[i].flags&VIFF_STATIC))
 793                         vif_delete(i);
 794         }
 795
 796         /*
 797          *      Wipe the cache
 798          */
 799         for (i=0;i<MFC_LINES;i++) {
 800                 struct mfc_cache *c, **cp;
 801
 802                 cp = &mfc_cache_array[i];
 803                 while ((c = *cp) != NULL) {
 804                         if (c->mfc_flags&MFC_STATIC) {
 805                                 cp = &c->next;
 806                                 continue;
 807                         }
 808                         write_lock_bh(&mrt_lock);
 809                         *cp = c->next;
 810                         write_unlock_bh(&mrt_lock);
 811
 812                         kmem_cache_free(mrt_cachep, c);
 813                 }
 814         }
 815
 816         if (atomic_read(&cache_resolve_queue_len) != 0) {
 817                 struct mfc_cache *c;
 818
 819                 spin_lock_bh(&mfc_unres_lock);
 820                 while (mfc_unres_queue != NULL) {
 821                         c = mfc_unres_queue;
 822                         mfc_unres_queue = c->next;
 823                         spin_unlock_bh(&mfc_unres_lock);
 824
 825                         ipmr_destroy_unres(c);
 826
 827                         spin_lock_bh(&mfc_unres_lock);
 828                 }
 829                 spin_unlock_bh(&mfc_unres_lock);
 830         }
 831 }
 832
 833 static void mrtsock_destruct(struct sock *sk)
 834 {
 835         rtnl_lock();
 836         if (sk == mroute_socket) {
 837                 ipv4_devconf.mc_forwarding--;
 838
 839                 write_lock_bh(&mrt_lock);
 840                 mroute_socket=NULL;
 841                 write_unlock_bh(&mrt_lock);
 842
 843                 mroute_clean_tables(sk);
 844         }
 845         rtnl_unlock();
 846 }
 847
 848 /*
 849  *      Socket options and virtual interface manipulation. The whole
 850  *      virtual interface system is a complete heap, but unfortunately
 851  *      that's how BSD mrouted happens to think. Maybe one day with a proper
 852  *      MOSPF/PIM router set up we can clean this up.
 853  */
 854
 855 int ip_mroute_setsockopt(struct sock *sk,int optname,char __user *optval,int optlen)
 856 {
 857         int ret;
 858         struct vifctl vif;
 859         struct mfcctl mfc;
 860
 861         if(optname!=MRT_INIT)
 862         {
 863                 if(sk!=mroute_socket && !capable(CAP_NET_ADMIN))
 864                         return -EACCES;
 865         }
 866
 867         switch(optname)
 868         {
 869                 case MRT_INIT:
 870                         if (sk->sk_type != SOCK_RAW ||
 871                             inet_sk(sk)->num != IPPROTO_IGMP)
 872                                 return -EOPNOTSUPP;
 873                         if(optlen!=sizeof(int))
 874                                 return -ENOPROTOOPT;
 875
 876                         rtnl_lock();
 877                         if (mroute_socket) {
 878                                 rtnl_unlock();
 879                                 return -EADDRINUSE;
 880                         }
 881
 882                         ret = ip_ra_control(sk, 1, mrtsock_destruct);
 883                         if (ret == 0) {
 884                                 write_lock_bh(&mrt_lock);
 885                                 mroute_socket=sk;
 886                                 write_unlock_bh(&mrt_lock);
 887
 888                                 ipv4_devconf.mc_forwarding++;
 889                         }
 890                         rtnl_unlock();
 891                         return ret;
 892                 case MRT_DONE:
 893                         if (sk!=mroute_socket)
 894                                 return -EACCES;
 895                         return ip_ra_control(sk, 0, NULL);
 896                 case MRT_ADD_VIF:
 897                 case MRT_DEL_VIF:
 898                         if(optlen!=sizeof(vif))
 899                                 return -EINVAL;
 900                         if (copy_from_user(&vif,optval,sizeof(vif)))
 901                                 return -EFAULT;
 902                         if(vif.vifc_vifi >= MAXVIFS)
 903                                 return -ENFILE;
 904                         rtnl_lock();
 905                         if (optname==MRT_ADD_VIF) {
 906                                 ret = vif_add(&vif, sk==mroute_socket);
 907                         } else {
 908                                 ret = vif_delete(vif.vifc_vifi);
 909                         }
 910                         rtnl_unlock();
 911                         return ret;
 912
 913                 /*
 914                  *      Manipulate the forwarding caches. These live
 915                  *      in a sort of kernel/user symbiosis.
 916                  */
 917                 case MRT_ADD_MFC:
 918                 case MRT_DEL_MFC:
 919                         if(optlen!=sizeof(mfc))
 920                                 return -EINVAL;
 921                         if (copy_from_user(&mfc,optval, sizeof(mfc)))
 922                                 return -EFAULT;
 923                         rtnl_lock();
 924                         if (optname==MRT_DEL_MFC)
 925                                 ret = ipmr_mfc_delete(&mfc);
 926                         else
 927                                 ret = ipmr_mfc_add(&mfc, sk==mroute_socket);
 928                         rtnl_unlock();
 929                         return ret;
 930                 /*
 931                  *      Control PIM assert.
 932                  */
 933                 case MRT_ASSERT:
 934                 {
 935                         int v;
 936                         if(get_user(v,(int __user *)optval))
 937                                 return -EFAULT;
 938                         mroute_do_assert=(v)?1:0;
 939                         return 0;
 940                 }
 941 #ifdef CONFIG_IP_PIMSM
 942                 case MRT_PIM:
 943                 {
 944                         int v, ret;
 945                         if(get_user(v,(int __user *)optval))
 946                                 return -EFAULT;
 947                         v = (v)?1:0;
 948                         rtnl_lock();
 949                         ret = 0;
 950                         if (v != mroute_do_pim) {
 951                                 mroute_do_pim = v;
 952                                 mroute_do_assert = v;
 953 #ifdef CONFIG_IP_PIMSM_V2
 954                                 if (mroute_do_pim)
 955                                         ret = inet_add_protocol(&pim_protocol,
 956                                                                 IPPROTO_PIM);
 957                                 else
 958                                         ret = inet_del_protocol(&pim_protocol,
 959                                                                 IPPROTO_PIM);
 960                                 if (ret < 0)
 961                                         ret = -EAGAIN;
 962 #endif
 963                         }
 964                         rtnl_unlock();
 965                         return ret;
 966                 }
 967 #endif
 968                 /*
 969                  *      Spurious command, or MRT_VERSION which you cannot
 970                  *      set.
 971                  */
 972                 default:
 973                         return -ENOPROTOOPT;
 974         }
 975 }
 976
 977 /*
 978  *      Getsock opt support for the multicast routing system.
 979  */
 980
 981 int ip_mroute_getsockopt(struct sock *sk,int optname,char __user *optval,int __user *optlen)
 982 {
 983         int olr;
 984         int val;
 985
 986         if(optname!=MRT_VERSION &&
 987 #ifdef CONFIG_IP_PIMSM
 988            optname!=MRT_PIM &&
 989 #endif
 990            optname!=MRT_ASSERT)
 991                 return -ENOPROTOOPT;
 992
 993         if (get_user(olr, optlen))
 994                 return -EFAULT;
 995
 996         olr = min_t(unsigned int, olr, sizeof(int));
 997         if (olr < 0)
 998                 return -EINVAL;
 999
1000         if(put_user(olr,optlen))
1001                 return -EFAULT;
1002         if(optname==MRT_VERSION)
1003                 val=0x0305;
1004 #ifdef CONFIG_IP_PIMSM
1005         else if(optname==MRT_PIM)
1006                 val=mroute_do_pim;
1007 #endif
1008         else
1009                 val=mroute_do_assert;
1010         if(copy_to_user(optval,&val,olr))
1011                 return -EFAULT;
1012         return 0;
1013 }
1014
1015 /*
1016  *      The IP multicast ioctl support routines.
1017  */
1018
1019 int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1020 {
1021         struct sioc_sg_req sr;
1022         struct sioc_vif_req vr;
1023         struct vif_device *vif;
1024         struct mfc_cache *c;
1025
1026         switch(cmd)
1027         {
1028                 case SIOCGETVIFCNT:
1029                         if (copy_from_user(&vr,arg,sizeof(vr)))
1030                                 return -EFAULT;
1031                         if(vr.vifi>=maxvif)
1032                                 return -EINVAL;
1033                         read_lock(&mrt_lock);
1034                         vif=&vif_table[vr.vifi];
1035                         if(VIF_EXISTS(vr.vifi)) {
1036                                 vr.icount=vif->pkt_in;
1037                                 vr.ocount=vif->pkt_out;
1038                                 vr.ibytes=vif->bytes_in;
1039                                 vr.obytes=vif->bytes_out;
1040                                 read_unlock(&mrt_lock);
1041
1042                                 if (copy_to_user(arg,&vr,sizeof(vr)))
1043                                         return -EFAULT;
1044                                 return 0;
1045                         }
1046                         read_unlock(&mrt_lock);
1047                         return -EADDRNOTAVAIL;
1048                 case SIOCGETSGCNT:
1049                         if (copy_from_user(&sr,arg,sizeof(sr)))
1050                                 return -EFAULT;
1051
1052                         read_lock(&mrt_lock);
1053                         c = ipmr_cache_find(sr.src.s_addr, sr.grp.s_addr);
1054                         if (c) {
1055                                 sr.pktcnt = c->mfc_un.res.pkt;
1056                                 sr.bytecnt = c->mfc_un.res.bytes;
1057                                 sr.wrong_if = c->mfc_un.res.wrong_if;
1058                                 read_unlock(&mrt_lock);
1059
1060                                 if (copy_to_user(arg,&sr,sizeof(sr)))
1061                                         return -EFAULT;
1062                                 return 0;
1063                         }
1064                         read_unlock(&mrt_lock);
1065                         return -EADDRNOTAVAIL;
1066                 default:
1067                         return -ENOIOCTLCMD;
1068         }
1069 }
1070
1071
1072 static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1073 {
1074         struct vif_device *v;
1075         int ct;
1076         if (event != NETDEV_UNREGISTER)
1077                 return NOTIFY_DONE;
1078         v=&vif_table[0];
1079         for(ct=0;ct<maxvif;ct++,v++) {
1080                 if (v->dev==ptr)
1081                         vif_delete(ct);
1082         }
1083         return NOTIFY_DONE;
1084 }
1085
1086
1087 static struct notifier_block ip_mr_notifier={
1088         .notifier_call = ipmr_device_event,
1089 };
1090
1091 /*
1092  *      Encapsulate a packet by attaching a valid IPIP header to it.
1093  *      This avoids tunnel drivers and other mess and gives us the speed so
1094  *      important for multicast video.
1095  */
1096
1097 static void ip_encap(struct sk_buff *skb, u32 saddr, u32 daddr)
1098 {
1099         struct iphdr *iph = (struct iphdr *)skb_push(skb,sizeof(struct iphdr));
1100
1101         iph->version    =       4;
1102         iph->tos        =       skb->nh.iph->tos;
1103         iph->ttl        =       skb->nh.iph->ttl;
1104         iph->frag_off   =       0;
1105         iph->daddr      =       daddr;
1106         iph->saddr      =       saddr;
1107         iph->protocol   =       IPPROTO_IPIP;
1108         iph->ihl        =       5;
1109         iph->tot_len    =       htons(skb->len);
1110         ip_select_ident(iph, skb->dst, NULL);
1111         ip_send_check(iph);
1112
1113         skb->h.ipiph = skb->nh.iph;
1114         skb->nh.iph = iph;
1115         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1116         nf_reset(skb);
1117 }
1118
1119 static inline int ipmr_forward_finish(struct sk_buff *skb)
1120 {
1121         struct ip_options * opt = &(IPCB(skb)->opt);
1122
1123         IP_INC_STATS_BH(IPSTATS_MIB_OUTFORWDATAGRAMS);
1124
1125         if (unlikely(opt->optlen))
1126                 ip_forward_options(skb);
1127
1128         return dst_output(skb);
1129 }
1130
1131 /*
1132  *      Processing handlers for ipmr_forward
1133  */
1134
1135 static void ipmr_queue_xmit(struct sk_buff *skb, struct mfc_cache *c, int vifi)
1136 {
1137         struct iphdr *iph = skb->nh.iph;
1138         struct vif_device *vif = &vif_table[vifi];
1139         struct net_device *dev;
1140         struct rtable *rt;
1141         int    encap = 0;
1142
1143         if (vif->dev == NULL)
1144                 goto out_free;
1145
1146 #ifdef CONFIG_IP_PIMSM
1147         if (vif->flags & VIFF_REGISTER) {
1148                 vif->pkt_out++;
1149                 vif->bytes_out+=skb->len;
1150                 ((struct net_device_stats*)vif->dev->priv)->tx_bytes += skb->len;
1151                 ((struct net_device_stats*)vif->dev->priv)->tx_packets++;
1152                 ipmr_cache_report(skb, vifi, IGMPMSG_WHOLEPKT);
1153                 kfree_skb(skb);
1154                 return;
1155         }
1156 #endif
1157
1158         if (vif->flags&VIFF_TUNNEL) {
1159                 struct flowi fl = { .oif = vif->link,
1160                                     .nl_u = { .ip4_u =
1161                                               { .daddr = vif->remote,
1162                                                 .saddr = vif->local,
1163                                                 .tos = RT_TOS(iph->tos) } },
1164                                     .proto = IPPROTO_IPIP };
1165                 if (ip_route_output_key(&rt, &fl))
1166                         goto out_free;
1167                 encap = sizeof(struct iphdr);
1168         } else {
1169                 struct flowi fl = { .oif = vif->link,
1170                                     .nl_u = { .ip4_u =
1171                                               { .daddr = iph->daddr,
1172                                                 .tos = RT_TOS(iph->tos) } },
1173                                     .proto = IPPROTO_IPIP };
1174                 if (ip_route_output_key(&rt, &fl))
1175                         goto out_free;
1176         }
1177
1178         dev = rt->u.dst.dev;
1179
1180         if (skb->len+encap > dst_mtu(&rt->u.dst) && (ntohs(iph->frag_off) & IP_DF)) {
1181                 /* Do not fragment multicasts. Alas, IPv4 does not
1182                    allow to send ICMP, so that packets will disappear
1183                    to blackhole.
1184                  */
1185
1186                 IP_INC_STATS_BH(IPSTATS_MIB_FRAGFAILS);
1187                 ip_rt_put(rt);
1188                 goto out_free;
1189         }
1190
1191         encap += LL_RESERVED_SPACE(dev) + rt->u.dst.header_len;
1192
1193         if (skb_cow(skb, encap)) {
1194                 ip_rt_put(rt);
1195                 goto out_free;
1196         }
1197
1198         vif->pkt_out++;
1199         vif->bytes_out+=skb->len;
1200
1201         dst_release(skb->dst);
1202         skb->dst = &rt->u.dst;
1203         iph = skb->nh.iph;
1204         ip_decrease_ttl(iph);
1205
1206         /* FIXME: forward and output firewalls used to be called here.
1207          * What do we do with netfilter? -- RR */
1208         if (vif->flags & VIFF_TUNNEL) {
1209                 ip_encap(skb, vif->local, vif->remote);
1210                 /* FIXME: extra output firewall step used to be here. --RR */
1211                 ((struct ip_tunnel *)vif->dev->priv)->stat.tx_packets++;
1212                 ((struct ip_tunnel *)vif->dev->priv)->stat.tx_bytes+=skb->len;
1213         }
1214
1215         IPCB(skb)->flags |= IPSKB_FORWARDED;
1216
1217         /*
1218          * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1219          * not only before forwarding, but after forwarding on all output
1220          * interfaces. It is clear, if mrouter runs a multicasting
1221          * program, it should receive packets not depending to what interface
1222          * program is joined.
1223          * If we will not make it, the program will have to join on all
1224          * interfaces. On the other hand, multihoming host (or router, but
1225          * not mrouter) cannot join to more than one interface - it will
1226          * result in receiving multiple packets.
1227          */
1228         NF_HOOK(PF_INET, NF_IP_FORWARD, skb, skb->dev, dev,
1229                 ipmr_forward_finish);
1230         return;
1231
1232 out_free:
1233         kfree_skb(skb);
1234         return;
1235 }
1236
1237 static int ipmr_find_vif(struct net_device *dev)
1238 {
1239         int ct;
1240         for (ct=maxvif-1; ct>=0; ct--) {
1241                 if (vif_table[ct].dev == dev)
1242                         break;
1243         }
1244         return ct;
1245 }
1246
1247 /* "local" means that we should preserve one skb (for local delivery) */
1248
1249 static int ip_mr_forward(struct sk_buff *skb, struct mfc_cache *cache, int local)
1250 {
1251         int psend = -1;
1252         int vif, ct;
1253
1254         vif = cache->mfc_parent;
1255         cache->mfc_un.res.pkt++;
1256         cache->mfc_un.res.bytes += skb->len;
1257
1258         /*
1259          * Wrong interface: drop packet and (maybe) send PIM assert.
1260          */
1261         if (vif_table[vif].dev != skb->dev) {
1262                 int true_vifi;
1263
1264                 if (((struct rtable*)skb->dst)->fl.iif == 0) {
1265                         /* It is our own packet, looped back.
1266                            Very complicated situation...
1267
1268                            The best workaround until routing daemons will be
1269                            fixed is not to redistribute packet, if it was
1270                            send through wrong interface. It means, that
1271                            multicast applications WILL NOT work for
1272                            (S,G), which have default multicast route pointing
1273                            to wrong oif. In any case, it is not a good
1274                            idea to use multicasting applications on router.
1275                          */
1276                         goto dont_forward;
1277                 }
1278
1279                 cache->mfc_un.res.wrong_if++;
1280                 true_vifi = ipmr_find_vif(skb->dev);
1281
1282                 if (true_vifi >= 0 && mroute_do_assert &&
1283                     /* pimsm uses asserts, when switching from RPT to SPT,
1284                        so that we cannot check that packet arrived on an oif.
1285                        It is bad, but otherwise we would need to move pretty
1286                        large chunk of pimd to kernel. Ough... --ANK
1287                      */
1288                     (mroute_do_pim || cache->mfc_un.res.ttls[true_vifi] < 255) &&
1289                     time_after(jiffies,
1290                                cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1291                         cache->mfc_un.res.last_assert = jiffies;
1292                         ipmr_cache_report(skb, true_vifi, IGMPMSG_WRONGVIF);
1293                 }
1294                 goto dont_forward;
1295         }
1296
1297         vif_table[vif].pkt_in++;
1298         vif_table[vif].bytes_in+=skb->len;
1299
1300         /*
1301          *      Forward the frame
1302          */
1303         for (ct = cache->mfc_un.res.maxvif-1; ct >= cache->mfc_un.res.minvif; ct--) {
1304                 if (skb->nh.iph->ttl > cache->mfc_un.res.ttls[ct]) {
1305                         if (psend != -1) {
1306                                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1307                                 if (skb2)
1308                                         ipmr_queue_xmit(skb2, cache, psend);
1309                         }
1310                         psend=ct;
1311                 }
1312         }
1313         if (psend != -1) {
1314                 if (local) {
1315                         struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1316                         if (skb2)
1317                                 ipmr_queue_xmit(skb2, cache, psend);
1318                 } else {
1319                         ipmr_queue_xmit(skb, cache, psend);
1320                         return 0;
1321                 }
1322         }
1323
1324 dont_forward:
1325         if (!local)
1326                 kfree_skb(skb);
1327         return 0;
1328 }
1329
1330
1331 /*
1332  *      Multicast packets for forwarding arrive here
1333  */
1334
1335 int ip_mr_input(struct sk_buff *skb)
1336 {
1337         struct mfc_cache *cache;
1338         int local = ((struct rtable*)skb->dst)->rt_flags&RTCF_LOCAL;
1339
1340         /* Packet is looped back after forward, it should not be
1341            forwarded second time, but still can be delivered locally.
1342          */
1343         if (IPCB(skb)->flags&IPSKB_FORWARDED)
1344                 goto dont_forward;
1345
1346         if (!local) {
1347                     if (IPCB(skb)->opt.router_alert) {
1348                             if (ip_call_ra_chain(skb))
1349                                     return 0;
1350                     } else if (skb->nh.iph->protocol == IPPROTO_IGMP){
1351                             /* IGMPv1 (and broken IGMPv2 implementations sort of
1352                                Cisco IOS <= 11.2(8)) do not put router alert
1353                                option to IGMP packets destined to routable
1354                                groups. It is very bad, because it means
1355                                that we can forward NO IGMP messages.
1356                              */
1357                             read_lock(&mrt_lock);
1358                             if (mroute_socket) {
1359                                     nf_reset(skb);
1360                                     raw_rcv(mroute_socket, skb);
1361                                     read_unlock(&mrt_lock);
1362                                     return 0;
1363                             }
1364                             read_unlock(&mrt_lock);
1365                     }
1366         }
1367
1368         read_lock(&mrt_lock);
1369         cache = ipmr_cache_find(skb->nh.iph->saddr, skb->nh.iph->daddr);
1370
1371         /*
1372          *      No usable cache entry
1373          */
1374         if (cache==NULL) {
1375                 int vif;
1376
1377                 if (local) {
1378                         struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1379                         ip_local_deliver(skb);
1380                         if (skb2 == NULL) {
1381                                 read_unlock(&mrt_lock);
1382                                 return -ENOBUFS;
1383                         }
1384                         skb = skb2;
1385                 }
1386
1387                 vif = ipmr_find_vif(skb->dev);
1388                 if (vif >= 0) {
1389                         int err = ipmr_cache_unresolved(vif, skb);
1390                         read_unlock(&mrt_lock);
1391
1392                         return err;
1393                 }
1394                 read_unlock(&mrt_lock);
1395                 kfree_skb(skb);
1396                 return -ENODEV;
1397         }
1398
1399         ip_mr_forward(skb, cache, local);
1400
1401         read_unlock(&mrt_lock);
1402
1403         if (local)
1404                 return ip_local_deliver(skb);
1405
1406         return 0;
1407
1408 dont_forward:
1409         if (local)
1410                 return ip_local_deliver(skb);
1411         kfree_skb(skb);
1412         return 0;
1413 }
1414
1415 #ifdef CONFIG_IP_PIMSM_V1
1416 /*
1417  * Handle IGMP messages of PIMv1
1418  */
1419
1420 int pim_rcv_v1(struct sk_buff * skb)
1421 {
1422         struct igmphdr *pim;
1423         struct iphdr   *encap;
1424         struct net_device  *reg_dev = NULL;
1425
1426         if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap)))
1427                 goto drop;
1428
1429         pim = (struct igmphdr*)skb->h.raw;
1430
1431         if (!mroute_do_pim ||
1432             skb->len < sizeof(*pim) + sizeof(*encap) ||
1433             pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
1434                 goto drop;
1435
1436         encap = (struct iphdr*)(skb->h.raw + sizeof(struct igmphdr));
1437         /*
1438            Check that:
1439            a. packet is really destinted to a multicast group
1440            b. packet is not a NULL-REGISTER
1441            c. packet is not truncated
1442          */
1443         if (!MULTICAST(encap->daddr) ||
1444             encap->tot_len == 0 ||
1445             ntohs(encap->tot_len) + sizeof(*pim) > skb->len)
1446                 goto drop;
1447
1448         read_lock(&mrt_lock);
1449         if (reg_vif_num >= 0)
1450                 reg_dev = vif_table[reg_vif_num].dev;
1451         if (reg_dev)
1452                 dev_hold(reg_dev);
1453         read_unlock(&mrt_lock);
1454
1455         if (reg_dev == NULL)
1456                 goto drop;
1457
1458         skb->mac.raw = skb->nh.raw;
1459         skb_pull(skb, (u8*)encap - skb->data);
1460         skb->nh.iph = (struct iphdr *)skb->data;
1461         skb->dev = reg_dev;
1462         memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
1463         skb->protocol = htons(ETH_P_IP);
1464         skb->ip_summed = 0;
1465         skb->pkt_type = PACKET_HOST;
1466         dst_release(skb->dst);
1467         skb->dst = NULL;
1468         ((struct net_device_stats*)reg_dev->priv)->rx_bytes += skb->len;
1469         ((struct net_device_stats*)reg_dev->priv)->rx_packets++;
1470         nf_reset(skb);
1471         netif_rx(skb);
1472         dev_put(reg_dev);
1473         return 0;
1474  drop:
1475         kfree_skb(skb);
1476         return 0;
1477 }
1478 #endif
1479
1480 #ifdef CONFIG_IP_PIMSM_V2
1481 static int pim_rcv(struct sk_buff * skb)
1482 {
1483         struct pimreghdr *pim;
1484         struct iphdr   *encap;
1485         struct net_device  *reg_dev = NULL;
1486
1487         if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(*encap)))
1488                 goto drop;
1489
1490         pim = (struct pimreghdr*)skb->h.raw;
1491         if (pim->type != ((PIM_VERSION<<4)|(PIM_REGISTER)) ||
1492             (pim->flags&PIM_NULL_REGISTER) ||
1493             (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
1494              (u16)csum_fold(skb_checksum(skb, 0, skb->len, 0))))
1495                 goto drop;
1496
1497         /* check if the inner packet is destined to mcast group */
1498         encap = (struct iphdr*)(skb->h.raw + sizeof(struct pimreghdr));
1499         if (!MULTICAST(encap->daddr) ||
1500             encap->tot_len == 0 ||
1501             ntohs(encap->tot_len) + sizeof(*pim) > skb->len)
1502                 goto drop;
1503
1504         read_lock(&mrt_lock);
1505         if (reg_vif_num >= 0)
1506                 reg_dev = vif_table[reg_vif_num].dev;
1507         if (reg_dev)
1508                 dev_hold(reg_dev);
1509         read_unlock(&mrt_lock);
1510
1511         if (reg_dev == NULL)
1512                 goto drop;
1513
1514         skb->mac.raw = skb->nh.raw;
1515         skb_pull(skb, (u8*)encap - skb->data);
1516         skb->nh.iph = (struct iphdr *)skb->data;
1517         skb->dev = reg_dev;
1518         memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
1519         skb->protocol = htons(ETH_P_IP);
1520         skb->ip_summed = 0;
1521         skb->pkt_type = PACKET_HOST;
1522         dst_release(skb->dst);
1523         ((struct net_device_stats*)reg_dev->priv)->rx_bytes += skb->len;
1524         ((struct net_device_stats*)reg_dev->priv)->rx_packets++;
1525         skb->dst = NULL;
1526         nf_reset(skb);
1527         netif_rx(skb);
1528         dev_put(reg_dev);
1529         return 0;
1530  drop:
1531         kfree_skb(skb);
1532         return 0;
1533 }
1534 #endif
1535
1536 static int
1537 ipmr_fill_mroute(struct sk_buff *skb, struct mfc_cache *c, struct rtmsg *rtm)
1538 {
1539         int ct;
1540         struct rtnexthop *nhp;
1541         struct net_device *dev = vif_table[c->mfc_parent].dev;
1542         u8 *b = skb->tail;
1543         struct rtattr *mp_head;
1544
1545         if (dev)
1546                 RTA_PUT(skb, RTA_IIF, 4, &dev->ifindex);
1547
1548         mp_head = (struct rtattr*)skb_put(skb, RTA_LENGTH(0));
1549
1550         for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
1551                 if (c->mfc_un.res.ttls[ct] < 255) {
1552                         if (skb_tailroom(skb) < RTA_ALIGN(RTA_ALIGN(sizeof(*nhp)) + 4))
1553                                 goto rtattr_failure;
1554                         nhp = (struct rtnexthop*)skb_put(skb, RTA_ALIGN(sizeof(*nhp)));
1555                         nhp->rtnh_flags = 0;
1556                         nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
1557                         nhp->rtnh_ifindex = vif_table[ct].dev->ifindex;
1558                         nhp->rtnh_len = sizeof(*nhp);
1559                 }
1560         }
1561         mp_head->rta_type = RTA_MULTIPATH;
1562         mp_head->rta_len = skb->tail - (u8*)mp_head;
1563         rtm->rtm_type = RTN_MULTICAST;
1564         return 1;
1565
1566 rtattr_failure:
1567         skb_trim(skb, b - skb->data);
1568         return -EMSGSIZE;
1569 }
1570
1571 int ipmr_get_route(struct sk_buff *skb, struct rtmsg *rtm, int nowait)
1572 {
1573         int err;
1574         struct mfc_cache *cache;
1575         struct rtable *rt = (struct rtable*)skb->dst;
1576
1577         read_lock(&mrt_lock);
1578         cache = ipmr_cache_find(rt->rt_src, rt->rt_dst);
1579
1580         if (cache==NULL) {
1581                 struct net_device *dev;
1582                 int vif;
1583
1584                 if (nowait) {
1585                         read_unlock(&mrt_lock);
1586                         return -EAGAIN;
1587                 }
1588
1589                 dev = skb->dev;
1590                 if (dev == NULL || (vif = ipmr_find_vif(dev)) < 0) {
1591                         read_unlock(&mrt_lock);
1592                         return -ENODEV;
1593                 }
1594                 skb->nh.raw = skb_push(skb, sizeof(struct iphdr));
1595                 skb->nh.iph->ihl = sizeof(struct iphdr)>>2;
1596                 skb->nh.iph->saddr = rt->rt_src;
1597                 skb->nh.iph->daddr = rt->rt_dst;
1598                 skb->nh.iph->version = 0;
1599                 err = ipmr_cache_unresolved(vif, skb);
1600                 read_unlock(&mrt_lock);
1601                 return err;
1602         }
1603
1604         if (!nowait && (rtm->rtm_flags&RTM_F_NOTIFY))
1605                 cache->mfc_flags |= MFC_NOTIFY;
1606         err = ipmr_fill_mroute(skb, cache, rtm);
1607         read_unlock(&mrt_lock);
1608         return err;
1609 }
1610
1611 #ifdef CONFIG_PROC_FS
1612 /*
1613  *      The /proc interfaces to multicast routing /proc/ip_mr_cache /proc/ip_mr_vif
1614  */
1615 struct ipmr_vif_iter {
1616         int ct;
1617 };
1618
1619 static struct vif_device *ipmr_vif_seq_idx(struct ipmr_vif_iter *iter,
1620                                            loff_t pos)
1621 {
1622         for (iter->ct = 0; iter->ct < maxvif; ++iter->ct) {
1623                 if(!VIF_EXISTS(iter->ct))
1624                         continue;
1625                 if (pos-- == 0)
1626                         return &vif_table[iter->ct];
1627         }
1628         return NULL;
1629 }
1630
1631 static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
1632 {
1633         read_lock(&mrt_lock);
1634         return *pos ? ipmr_vif_seq_idx(seq->private, *pos - 1)
1635                 : SEQ_START_TOKEN;
1636 }
1637
1638 static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1639 {
1640         struct ipmr_vif_iter *iter = seq->private;
1641
1642         ++*pos;
1643         if (v == SEQ_START_TOKEN)
1644                 return ipmr_vif_seq_idx(iter, 0);
1645
1646         while (++iter->ct < maxvif) {
1647                 if(!VIF_EXISTS(iter->ct))
1648                         continue;
1649                 return &vif_table[iter->ct];
1650         }
1651         return NULL;
1652 }
1653
1654 static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
1655 {
1656         read_unlock(&mrt_lock);
1657 }
1658
1659 static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
1660 {
1661         if (v == SEQ_START_TOKEN) {
1662                 seq_puts(seq,
1663                          "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
1664         } else {
1665                 const struct vif_device *vif = v;
1666                 const char *name =  vif->dev ? vif->dev->name : "none";
1667
1668                 seq_printf(seq,
1669                            "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
1670                            vif - vif_table,
1671                            name, vif->bytes_in, vif->pkt_in,
1672                            vif->bytes_out, vif->pkt_out,
1673                            vif->flags, vif->local, vif->remote);
1674         }
1675         return 0;
1676 }
1677
1678 static struct seq_operations ipmr_vif_seq_ops = {
1679         .start = ipmr_vif_seq_start,
1680         .next  = ipmr_vif_seq_next,
1681         .stop  = ipmr_vif_seq_stop,
1682         .show  = ipmr_vif_seq_show,
1683 };
1684
1685 static int ipmr_vif_open(struct inode *inode, struct file *file)
1686 {
1687         struct seq_file *seq;
1688         int rc = -ENOMEM;
1689         struct ipmr_vif_iter *s = kmalloc(sizeof(*s), GFP_KERNEL);
1690
1691         if (!s)
1692                 goto out;
1693
1694         rc = seq_open(file, &ipmr_vif_seq_ops);
1695         if (rc)
1696                 goto out_kfree;
1697
1698         s->ct = 0;
1699         seq = file->private_data;
1700         seq->private = s;
1701 out:
1702         return rc;
1703 out_kfree:
1704         kfree(s);
1705         goto out;
1706
1707 }
1708
1709 static struct file_operations ipmr_vif_fops = {
1710         .owner   = THIS_MODULE,
1711         .open    = ipmr_vif_open,
1712         .read    = seq_read,
1713         .llseek  = seq_lseek,
1714         .release = seq_release_private,
1715 };
1716
1717 struct ipmr_mfc_iter {
1718         struct mfc_cache **cache;
1719         int ct;
1720 };
1721
1722
1723 static struct mfc_cache *ipmr_mfc_seq_idx(struct ipmr_mfc_iter *it, loff_t pos)
1724 {
1725         struct mfc_cache *mfc;
1726
1727         it->cache = mfc_cache_array;
1728         read_lock(&mrt_lock);
1729         for (it->ct = 0; it->ct < MFC_LINES; it->ct++)
1730                 for(mfc = mfc_cache_array[it->ct]; mfc; mfc = mfc->next)
1731                         if (pos-- == 0)
1732                                 return mfc;
1733         read_unlock(&mrt_lock);
1734
1735         it->cache = &mfc_unres_queue;
1736         spin_lock_bh(&mfc_unres_lock);
1737         for(mfc = mfc_unres_queue; mfc; mfc = mfc->next)
1738                 if (pos-- == 0)
1739                         return mfc;
1740         spin_unlock_bh(&mfc_unres_lock);
1741
1742         it->cache = NULL;
1743         return NULL;
1744 }
1745
1746
1747 static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
1748 {
1749         struct ipmr_mfc_iter *it = seq->private;
1750         it->cache = NULL;
1751         it->ct = 0;
1752         return *pos ? ipmr_mfc_seq_idx(seq->private, *pos - 1)
1753                 : SEQ_START_TOKEN;
1754 }
1755
1756 static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1757 {
1758         struct mfc_cache *mfc = v;
1759         struct ipmr_mfc_iter *it = seq->private;
1760
1761         ++*pos;
1762
1763         if (v == SEQ_START_TOKEN)
1764                 return ipmr_mfc_seq_idx(seq->private, 0);
1765
1766         if (mfc->next)
1767                 return mfc->next;
1768
1769         if (it->cache == &mfc_unres_queue)
1770                 goto end_of_list;
1771
1772         BUG_ON(it->cache != mfc_cache_array);
1773
1774         while (++it->ct < MFC_LINES) {
1775                 mfc = mfc_cache_array[it->ct];
1776                 if (mfc)
1777                         return mfc;
1778         }
1779
1780         /* exhausted cache_array, show unresolved */
1781         read_unlock(&mrt_lock);
1782         it->cache = &mfc_unres_queue;
1783         it->ct = 0;
1784
1785         spin_lock_bh(&mfc_unres_lock);
1786         mfc = mfc_unres_queue;
1787         if (mfc)
1788                 return mfc;
1789
1790  end_of_list:
1791         spin_unlock_bh(&mfc_unres_lock);
1792         it->cache = NULL;
1793
1794         return NULL;
1795 }
1796
1797 static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
1798 {
1799         struct ipmr_mfc_iter *it = seq->private;
1800
1801         if (it->cache == &mfc_unres_queue)
1802                 spin_unlock_bh(&mfc_unres_lock);
1803         else if (it->cache == mfc_cache_array)
1804                 read_unlock(&mrt_lock);
1805 }
1806
1807 static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
1808 {
1809         int n;
1810
1811         if (v == SEQ_START_TOKEN) {
1812                 seq_puts(seq,
1813                  "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
1814         } else {
1815                 const struct mfc_cache *mfc = v;
1816                 const struct ipmr_mfc_iter *it = seq->private;
1817
1818                 seq_printf(seq, "%08lX %08lX %-3d %8ld %8ld %8ld",
1819                            (unsigned long) mfc->mfc_mcastgrp,
1820                            (unsigned long) mfc->mfc_origin,
1821                            mfc->mfc_parent,
1822                            mfc->mfc_un.res.pkt,
1823                            mfc->mfc_un.res.bytes,
1824                            mfc->mfc_un.res.wrong_if);
1825
1826                 if (it->cache != &mfc_unres_queue) {
1827                         for(n = mfc->mfc_un.res.minvif;
1828                             n < mfc->mfc_un.res.maxvif; n++ ) {
1829                                 if(VIF_EXISTS(n)
1830                                    && mfc->mfc_un.res.ttls[n] < 255)
1831                                 seq_printf(seq,
1832                                            " %2d:%-3d",
1833                                            n, mfc->mfc_un.res.ttls[n]);
1834                         }
1835                 }
1836                 seq_putc(seq, '\n');
1837         }
1838         return 0;
1839 }
1840
1841 static struct seq_operations ipmr_mfc_seq_ops = {
1842         .start = ipmr_mfc_seq_start,
1843         .next  = ipmr_mfc_seq_next,
1844         .stop  = ipmr_mfc_seq_stop,
1845         .show  = ipmr_mfc_seq_show,
1846 };
1847
1848 static int ipmr_mfc_open(struct inode *inode, struct file *file)
1849 {
1850         struct seq_file *seq;
1851         int rc = -ENOMEM;
1852         struct ipmr_mfc_iter *s = kmalloc(sizeof(*s), GFP_KERNEL);
1853
1854         if (!s)
1855                 goto out;
1856
1857         rc = seq_open(file, &ipmr_mfc_seq_ops);
1858         if (rc)
1859                 goto out_kfree;
1860
1861         seq = file->private_data;
1862         seq->private = s;
1863 out:
1864         return rc;
1865 out_kfree:
1866         kfree(s);
1867         goto out;
1868
1869 }
1870
1871 static struct file_operations ipmr_mfc_fops = {
1872         .owner   = THIS_MODULE,
1873         .open    = ipmr_mfc_open,
1874         .read    = seq_read,
1875         .llseek  = seq_lseek,
1876         .release = seq_release_private,
1877 };
1878 #endif
1879
1880 #ifdef CONFIG_IP_PIMSM_V2
1881 static struct net_protocol pim_protocol = {
1882         .handler        =       pim_rcv,
1883 };
1884 #endif
1885
1886
1887 /*
1888  *      Setup for IP multicast routing
1889  */
1890
1891 void __init ip_mr_init(void)
1892 {
1893         mrt_cachep = kmem_cache_create("ip_mrt_cache",
1894                                        sizeof(struct mfc_cache),
1895                                        0, SLAB_HWCACHE_ALIGN,
1896                                        NULL, NULL);
1897         if (!mrt_cachep)
1898                 panic("cannot allocate ip_mrt_cache");
1899
1900         init_timer(&ipmr_expire_timer);
1901         ipmr_expire_timer.function=ipmr_expire_process;
1902         register_netdevice_notifier(&ip_mr_notifier);
1903 #ifdef CONFIG_PROC_FS
1904         proc_net_fops_create("ip_mr_vif", 0, &ipmr_vif_fops);
1905         proc_net_fops_create("ip_mr_cache", 0, &ipmr_mfc_fops);
1906 #endif
1907 }