linux/net/ipv4/ipmr.c
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   1/*
   2 *      IP multicast routing support for mrouted 3.6/3.8
   3 *
   4 *              (c) 1995 Alan Cox, <alan@lxorguk.ukuu.org.uk>
   5 *        Linux Consultancy and Custom Driver Development
   6 *
   7 *      This program is free software; you can redistribute it and/or
   8 *      modify it under the terms of the GNU General Public License
   9 *      as published by the Free Software Foundation; either version
  10 *      2 of the License, or (at your option) any later version.
  11 *
  12 *      Fixes:
  13 *      Michael Chastain        :       Incorrect size of copying.
  14 *      Alan Cox                :       Added the cache manager code
  15 *      Alan Cox                :       Fixed the clone/copy bug and device race.
  16 *      Mike McLagan            :       Routing by source
  17 *      Malcolm Beattie         :       Buffer handling fixes.
  18 *      Alexey Kuznetsov        :       Double buffer free and other fixes.
  19 *      SVR Anand               :       Fixed several multicast bugs and problems.
  20 *      Alexey Kuznetsov        :       Status, optimisations and more.
  21 *      Brad Parker             :       Better behaviour on mrouted upcall
  22 *                                      overflow.
  23 *      Carlos Picoto           :       PIMv1 Support
  24 *      Pavlin Ivanov Radoslavov:       PIMv2 Registers must checksum only PIM header
  25 *                                      Relax this requirement to work with older peers.
  26 *
  27 */
  28
  29#include <asm/uaccess.h>
  30#include <linux/types.h>
  31#include <linux/capability.h>
  32#include <linux/errno.h>
  33#include <linux/timer.h>
  34#include <linux/mm.h>
  35#include <linux/kernel.h>
  36#include <linux/fcntl.h>
  37#include <linux/stat.h>
  38#include <linux/socket.h>
  39#include <linux/in.h>
  40#include <linux/inet.h>
  41#include <linux/netdevice.h>
  42#include <linux/inetdevice.h>
  43#include <linux/igmp.h>
  44#include <linux/proc_fs.h>
  45#include <linux/seq_file.h>
  46#include <linux/mroute.h>
  47#include <linux/init.h>
  48#include <linux/if_ether.h>
  49#include <linux/slab.h>
  50#include <net/net_namespace.h>
  51#include <net/ip.h>
  52#include <net/protocol.h>
  53#include <linux/skbuff.h>
  54#include <net/route.h>
  55#include <net/sock.h>
  56#include <net/icmp.h>
  57#include <net/udp.h>
  58#include <net/raw.h>
  59#include <linux/notifier.h>
  60#include <linux/if_arp.h>
  61#include <linux/netfilter_ipv4.h>
  62#include <linux/compat.h>
  63#include <linux/export.h>
  64#include <net/ipip.h>
  65#include <net/checksum.h>
  66#include <net/netlink.h>
  67#include <net/fib_rules.h>
  68
  69#if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
  70#define CONFIG_IP_PIMSM 1
  71#endif
  72
  73struct mr_table {
  74        struct list_head        list;
  75#ifdef CONFIG_NET_NS
  76        struct net              *net;
  77#endif
  78        u32                     id;
  79        struct sock __rcu       *mroute_sk;
  80        struct timer_list       ipmr_expire_timer;
  81        struct list_head        mfc_unres_queue;
  82        struct list_head        mfc_cache_array[MFC_LINES];
  83        struct vif_device       vif_table[MAXVIFS];
  84        int                     maxvif;
  85        atomic_t                cache_resolve_queue_len;
  86        int                     mroute_do_assert;
  87        int                     mroute_do_pim;
  88#if defined(CONFIG_IP_PIMSM_V1) || defined(CONFIG_IP_PIMSM_V2)
  89        int                     mroute_reg_vif_num;
  90#endif
  91};
  92
  93struct ipmr_rule {
  94        struct fib_rule         common;
  95};
  96
  97struct ipmr_result {
  98        struct mr_table         *mrt;
  99};
 100
 101/* Big lock, protecting vif table, mrt cache and mroute socket state.
 102 * Note that the changes are semaphored via rtnl_lock.
 103 */
 104
 105static DEFINE_RWLOCK(mrt_lock);
 106
 107/*
 108 *      Multicast router control variables
 109 */
 110
 111#define VIF_EXISTS(_mrt, _idx) ((_mrt)->vif_table[_idx].dev != NULL)
 112
 113/* Special spinlock for queue of unresolved entries */
 114static DEFINE_SPINLOCK(mfc_unres_lock);
 115
 116/* We return to original Alan's scheme. Hash table of resolved
 117 * entries is changed only in process context and protected
 118 * with weak lock mrt_lock. Queue of unresolved entries is protected
 119 * with strong spinlock mfc_unres_lock.
 120 *
 121 * In this case data path is free of exclusive locks at all.
 122 */
 123
 124static struct kmem_cache *mrt_cachep __read_mostly;
 125
 126static struct mr_table *ipmr_new_table(struct net *net, u32 id);
 127static void ipmr_free_table(struct mr_table *mrt);
 128
 129static int ip_mr_forward(struct net *net, struct mr_table *mrt,
 130                         struct sk_buff *skb, struct mfc_cache *cache,
 131                         int local);
 132static int ipmr_cache_report(struct mr_table *mrt,
 133                             struct sk_buff *pkt, vifi_t vifi, int assert);
 134static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
 135                              struct mfc_cache *c, struct rtmsg *rtm);
 136static void mroute_clean_tables(struct mr_table *mrt);
 137static void ipmr_expire_process(unsigned long arg);
 138
 139#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
 140#define ipmr_for_each_table(mrt, net) \
 141        list_for_each_entry_rcu(mrt, &net->ipv4.mr_tables, list)
 142
 143static struct mr_table *ipmr_get_table(struct net *net, u32 id)
 144{
 145        struct mr_table *mrt;
 146
 147        ipmr_for_each_table(mrt, net) {
 148                if (mrt->id == id)
 149                        return mrt;
 150        }
 151        return NULL;
 152}
 153
 154static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
 155                           struct mr_table **mrt)
 156{
 157        struct ipmr_result res;
 158        struct fib_lookup_arg arg = { .result = &res, };
 159        int err;
 160
 161        err = fib_rules_lookup(net->ipv4.mr_rules_ops,
 162                               flowi4_to_flowi(flp4), 0, &arg);
 163        if (err < 0)
 164                return err;
 165        *mrt = res.mrt;
 166        return 0;
 167}
 168
 169static int ipmr_rule_action(struct fib_rule *rule, struct flowi *flp,
 170                            int flags, struct fib_lookup_arg *arg)
 171{
 172        struct ipmr_result *res = arg->result;
 173        struct mr_table *mrt;
 174
 175        switch (rule->action) {
 176        case FR_ACT_TO_TBL:
 177                break;
 178        case FR_ACT_UNREACHABLE:
 179                return -ENETUNREACH;
 180        case FR_ACT_PROHIBIT:
 181                return -EACCES;
 182        case FR_ACT_BLACKHOLE:
 183        default:
 184                return -EINVAL;
 185        }
 186
 187        mrt = ipmr_get_table(rule->fr_net, rule->table);
 188        if (mrt == NULL)
 189                return -EAGAIN;
 190        res->mrt = mrt;
 191        return 0;
 192}
 193
 194static int ipmr_rule_match(struct fib_rule *rule, struct flowi *fl, int flags)
 195{
 196        return 1;
 197}
 198
 199static const struct nla_policy ipmr_rule_policy[FRA_MAX + 1] = {
 200        FRA_GENERIC_POLICY,
 201};
 202
 203static int ipmr_rule_configure(struct fib_rule *rule, struct sk_buff *skb,
 204                               struct fib_rule_hdr *frh, struct nlattr **tb)
 205{
 206        return 0;
 207}
 208
 209static int ipmr_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh,
 210                             struct nlattr **tb)
 211{
 212        return 1;
 213}
 214
 215static int ipmr_rule_fill(struct fib_rule *rule, struct sk_buff *skb,
 216                          struct fib_rule_hdr *frh)
 217{
 218        frh->dst_len = 0;
 219        frh->src_len = 0;
 220        frh->tos     = 0;
 221        return 0;
 222}
 223
 224static const struct fib_rules_ops __net_initdata ipmr_rules_ops_template = {
 225        .family         = RTNL_FAMILY_IPMR,
 226        .rule_size      = sizeof(struct ipmr_rule),
 227        .addr_size      = sizeof(u32),
 228        .action         = ipmr_rule_action,
 229        .match          = ipmr_rule_match,
 230        .configure      = ipmr_rule_configure,
 231        .compare        = ipmr_rule_compare,
 232        .default_pref   = fib_default_rule_pref,
 233        .fill           = ipmr_rule_fill,
 234        .nlgroup        = RTNLGRP_IPV4_RULE,
 235        .policy         = ipmr_rule_policy,
 236        .owner          = THIS_MODULE,
 237};
 238
 239static int __net_init ipmr_rules_init(struct net *net)
 240{
 241        struct fib_rules_ops *ops;
 242        struct mr_table *mrt;
 243        int err;
 244
 245        ops = fib_rules_register(&ipmr_rules_ops_template, net);
 246        if (IS_ERR(ops))
 247                return PTR_ERR(ops);
 248
 249        INIT_LIST_HEAD(&net->ipv4.mr_tables);
 250
 251        mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
 252        if (mrt == NULL) {
 253                err = -ENOMEM;
 254                goto err1;
 255        }
 256
 257        err = fib_default_rule_add(ops, 0x7fff, RT_TABLE_DEFAULT, 0);
 258        if (err < 0)
 259                goto err2;
 260
 261        net->ipv4.mr_rules_ops = ops;
 262        return 0;
 263
 264err2:
 265        kfree(mrt);
 266err1:
 267        fib_rules_unregister(ops);
 268        return err;
 269}
 270
 271static void __net_exit ipmr_rules_exit(struct net *net)
 272{
 273        struct mr_table *mrt, *next;
 274
 275        list_for_each_entry_safe(mrt, next, &net->ipv4.mr_tables, list) {
 276                list_del(&mrt->list);
 277                ipmr_free_table(mrt);
 278        }
 279        fib_rules_unregister(net->ipv4.mr_rules_ops);
 280}
 281#else
 282#define ipmr_for_each_table(mrt, net) \
 283        for (mrt = net->ipv4.mrt; mrt; mrt = NULL)
 284
 285static struct mr_table *ipmr_get_table(struct net *net, u32 id)
 286{
 287        return net->ipv4.mrt;
 288}
 289
 290static int ipmr_fib_lookup(struct net *net, struct flowi4 *flp4,
 291                           struct mr_table **mrt)
 292{
 293        *mrt = net->ipv4.mrt;
 294        return 0;
 295}
 296
 297static int __net_init ipmr_rules_init(struct net *net)
 298{
 299        net->ipv4.mrt = ipmr_new_table(net, RT_TABLE_DEFAULT);
 300        return net->ipv4.mrt ? 0 : -ENOMEM;
 301}
 302
 303static void __net_exit ipmr_rules_exit(struct net *net)
 304{
 305        ipmr_free_table(net->ipv4.mrt);
 306}
 307#endif
 308
 309static struct mr_table *ipmr_new_table(struct net *net, u32 id)
 310{
 311        struct mr_table *mrt;
 312        unsigned int i;
 313
 314        mrt = ipmr_get_table(net, id);
 315        if (mrt != NULL)
 316                return mrt;
 317
 318        mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
 319        if (mrt == NULL)
 320                return NULL;
 321        write_pnet(&mrt->net, net);
 322        mrt->id = id;
 323
 324        /* Forwarding cache */
 325        for (i = 0; i < MFC_LINES; i++)
 326                INIT_LIST_HEAD(&mrt->mfc_cache_array[i]);
 327
 328        INIT_LIST_HEAD(&mrt->mfc_unres_queue);
 329
 330        setup_timer(&mrt->ipmr_expire_timer, ipmr_expire_process,
 331                    (unsigned long)mrt);
 332
 333#ifdef CONFIG_IP_PIMSM
 334        mrt->mroute_reg_vif_num = -1;
 335#endif
 336#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
 337        list_add_tail_rcu(&mrt->list, &net->ipv4.mr_tables);
 338#endif
 339        return mrt;
 340}
 341
 342static void ipmr_free_table(struct mr_table *mrt)
 343{
 344        del_timer_sync(&mrt->ipmr_expire_timer);
 345        mroute_clean_tables(mrt);
 346        kfree(mrt);
 347}
 348
 349/* Service routines creating virtual interfaces: DVMRP tunnels and PIMREG */
 350
 351static void ipmr_del_tunnel(struct net_device *dev, struct vifctl *v)
 352{
 353        struct net *net = dev_net(dev);
 354
 355        dev_close(dev);
 356
 357        dev = __dev_get_by_name(net, "tunl0");
 358        if (dev) {
 359                const struct net_device_ops *ops = dev->netdev_ops;
 360                struct ifreq ifr;
 361                struct ip_tunnel_parm p;
 362
 363                memset(&p, 0, sizeof(p));
 364                p.iph.daddr = v->vifc_rmt_addr.s_addr;
 365                p.iph.saddr = v->vifc_lcl_addr.s_addr;
 366                p.iph.version = 4;
 367                p.iph.ihl = 5;
 368                p.iph.protocol = IPPROTO_IPIP;
 369                sprintf(p.name, "dvmrp%d", v->vifc_vifi);
 370                ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
 371
 372                if (ops->ndo_do_ioctl) {
 373                        mm_segment_t oldfs = get_fs();
 374
 375                        set_fs(KERNEL_DS);
 376                        ops->ndo_do_ioctl(dev, &ifr, SIOCDELTUNNEL);
 377                        set_fs(oldfs);
 378                }
 379        }
 380}
 381
 382static
 383struct net_device *ipmr_new_tunnel(struct net *net, struct vifctl *v)
 384{
 385        struct net_device  *dev;
 386
 387        dev = __dev_get_by_name(net, "tunl0");
 388
 389        if (dev) {
 390                const struct net_device_ops *ops = dev->netdev_ops;
 391                int err;
 392                struct ifreq ifr;
 393                struct ip_tunnel_parm p;
 394                struct in_device  *in_dev;
 395
 396                memset(&p, 0, sizeof(p));
 397                p.iph.daddr = v->vifc_rmt_addr.s_addr;
 398                p.iph.saddr = v->vifc_lcl_addr.s_addr;
 399                p.iph.version = 4;
 400                p.iph.ihl = 5;
 401                p.iph.protocol = IPPROTO_IPIP;
 402                sprintf(p.name, "dvmrp%d", v->vifc_vifi);
 403                ifr.ifr_ifru.ifru_data = (__force void __user *)&p;
 404
 405                if (ops->ndo_do_ioctl) {
 406                        mm_segment_t oldfs = get_fs();
 407
 408                        set_fs(KERNEL_DS);
 409                        err = ops->ndo_do_ioctl(dev, &ifr, SIOCADDTUNNEL);
 410                        set_fs(oldfs);
 411                } else {
 412                        err = -EOPNOTSUPP;
 413                }
 414                dev = NULL;
 415
 416                if (err == 0 &&
 417                    (dev = __dev_get_by_name(net, p.name)) != NULL) {
 418                        dev->flags |= IFF_MULTICAST;
 419
 420                        in_dev = __in_dev_get_rtnl(dev);
 421                        if (in_dev == NULL)
 422                                goto failure;
 423
 424                        ipv4_devconf_setall(in_dev);
 425                        IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
 426
 427                        if (dev_open(dev))
 428                                goto failure;
 429                        dev_hold(dev);
 430                }
 431        }
 432        return dev;
 433
 434failure:
 435        /* allow the register to be completed before unregistering. */
 436        rtnl_unlock();
 437        rtnl_lock();
 438
 439        unregister_netdevice(dev);
 440        return NULL;
 441}
 442
 443#ifdef CONFIG_IP_PIMSM
 444
 445static netdev_tx_t reg_vif_xmit(struct sk_buff *skb, struct net_device *dev)
 446{
 447        struct net *net = dev_net(dev);
 448        struct mr_table *mrt;
 449        struct flowi4 fl4 = {
 450                .flowi4_oif     = dev->ifindex,
 451                .flowi4_iif     = skb->skb_iif,
 452                .flowi4_mark    = skb->mark,
 453        };
 454        int err;
 455
 456        err = ipmr_fib_lookup(net, &fl4, &mrt);
 457        if (err < 0) {
 458                kfree_skb(skb);
 459                return err;
 460        }
 461
 462        read_lock(&mrt_lock);
 463        dev->stats.tx_bytes += skb->len;
 464        dev->stats.tx_packets++;
 465        ipmr_cache_report(mrt, skb, mrt->mroute_reg_vif_num, IGMPMSG_WHOLEPKT);
 466        read_unlock(&mrt_lock);
 467        kfree_skb(skb);
 468        return NETDEV_TX_OK;
 469}
 470
 471static const struct net_device_ops reg_vif_netdev_ops = {
 472        .ndo_start_xmit = reg_vif_xmit,
 473};
 474
 475static void reg_vif_setup(struct net_device *dev)
 476{
 477        dev->type               = ARPHRD_PIMREG;
 478        dev->mtu                = ETH_DATA_LEN - sizeof(struct iphdr) - 8;
 479        dev->flags              = IFF_NOARP;
 480        dev->netdev_ops         = &reg_vif_netdev_ops,
 481        dev->destructor         = free_netdev;
 482        dev->features           |= NETIF_F_NETNS_LOCAL;
 483}
 484
 485static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)
 486{
 487        struct net_device *dev;
 488        struct in_device *in_dev;
 489        char name[IFNAMSIZ];
 490
 491        if (mrt->id == RT_TABLE_DEFAULT)
 492                sprintf(name, "pimreg");
 493        else
 494                sprintf(name, "pimreg%u", mrt->id);
 495
 496        dev = alloc_netdev(0, name, reg_vif_setup);
 497
 498        if (dev == NULL)
 499                return NULL;
 500
 501        dev_net_set(dev, net);
 502
 503        if (register_netdevice(dev)) {
 504                free_netdev(dev);
 505                return NULL;
 506        }
 507        dev->iflink = 0;
 508
 509        rcu_read_lock();
 510        in_dev = __in_dev_get_rcu(dev);
 511        if (!in_dev) {
 512                rcu_read_unlock();
 513                goto failure;
 514        }
 515
 516        ipv4_devconf_setall(in_dev);
 517        IPV4_DEVCONF(in_dev->cnf, RP_FILTER) = 0;
 518        rcu_read_unlock();
 519
 520        if (dev_open(dev))
 521                goto failure;
 522
 523        dev_hold(dev);
 524
 525        return dev;
 526
 527failure:
 528        /* allow the register to be completed before unregistering. */
 529        rtnl_unlock();
 530        rtnl_lock();
 531
 532        unregister_netdevice(dev);
 533        return NULL;
 534}
 535#endif
 536
 537/**
 538 *      vif_delete - Delete a VIF entry
 539 *      @notify: Set to 1, if the caller is a notifier_call
 540 */
 541
 542static int vif_delete(struct mr_table *mrt, int vifi, int notify,
 543                      struct list_head *head)
 544{
 545        struct vif_device *v;
 546        struct net_device *dev;
 547        struct in_device *in_dev;
 548
 549        if (vifi < 0 || vifi >= mrt->maxvif)
 550                return -EADDRNOTAVAIL;
 551
 552        v = &mrt->vif_table[vifi];
 553
 554        write_lock_bh(&mrt_lock);
 555        dev = v->dev;
 556        v->dev = NULL;
 557
 558        if (!dev) {
 559                write_unlock_bh(&mrt_lock);
 560                return -EADDRNOTAVAIL;
 561        }
 562
 563#ifdef CONFIG_IP_PIMSM
 564        if (vifi == mrt->mroute_reg_vif_num)
 565                mrt->mroute_reg_vif_num = -1;
 566#endif
 567
 568        if (vifi + 1 == mrt->maxvif) {
 569                int tmp;
 570
 571                for (tmp = vifi - 1; tmp >= 0; tmp--) {
 572                        if (VIF_EXISTS(mrt, tmp))
 573                                break;
 574                }
 575                mrt->maxvif = tmp+1;
 576        }
 577
 578        write_unlock_bh(&mrt_lock);
 579
 580        dev_set_allmulti(dev, -1);
 581
 582        in_dev = __in_dev_get_rtnl(dev);
 583        if (in_dev) {
 584                IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)--;
 585                ip_rt_multicast_event(in_dev);
 586        }
 587
 588        if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER) && !notify)
 589                unregister_netdevice_queue(dev, head);
 590
 591        dev_put(dev);
 592        return 0;
 593}
 594
 595static void ipmr_cache_free_rcu(struct rcu_head *head)
 596{
 597        struct mfc_cache *c = container_of(head, struct mfc_cache, rcu);
 598
 599        kmem_cache_free(mrt_cachep, c);
 600}
 601
 602static inline void ipmr_cache_free(struct mfc_cache *c)
 603{
 604        call_rcu(&c->rcu, ipmr_cache_free_rcu);
 605}
 606
 607/* Destroy an unresolved cache entry, killing queued skbs
 608 * and reporting error to netlink readers.
 609 */
 610
 611static void ipmr_destroy_unres(struct mr_table *mrt, struct mfc_cache *c)
 612{
 613        struct net *net = read_pnet(&mrt->net);
 614        struct sk_buff *skb;
 615        struct nlmsgerr *e;
 616
 617        atomic_dec(&mrt->cache_resolve_queue_len);
 618
 619        while ((skb = skb_dequeue(&c->mfc_un.unres.unresolved))) {
 620                if (ip_hdr(skb)->version == 0) {
 621                        struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
 622                        nlh->nlmsg_type = NLMSG_ERROR;
 623                        nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
 624                        skb_trim(skb, nlh->nlmsg_len);
 625                        e = NLMSG_DATA(nlh);
 626                        e->error = -ETIMEDOUT;
 627                        memset(&e->msg, 0, sizeof(e->msg));
 628
 629                        rtnl_unicast(skb, net, NETLINK_CB(skb).pid);
 630                } else {
 631                        kfree_skb(skb);
 632                }
 633        }
 634
 635        ipmr_cache_free(c);
 636}
 637
 638
 639/* Timer process for the unresolved queue. */
 640
 641static void ipmr_expire_process(unsigned long arg)
 642{
 643        struct mr_table *mrt = (struct mr_table *)arg;
 644        unsigned long now;
 645        unsigned long expires;
 646        struct mfc_cache *c, *next;
 647
 648        if (!spin_trylock(&mfc_unres_lock)) {
 649                mod_timer(&mrt->ipmr_expire_timer, jiffies+HZ/10);
 650                return;
 651        }
 652
 653        if (list_empty(&mrt->mfc_unres_queue))
 654                goto out;
 655
 656        now = jiffies;
 657        expires = 10*HZ;
 658
 659        list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
 660                if (time_after(c->mfc_un.unres.expires, now)) {
 661                        unsigned long interval = c->mfc_un.unres.expires - now;
 662                        if (interval < expires)
 663                                expires = interval;
 664                        continue;
 665                }
 666
 667                list_del(&c->list);
 668                ipmr_destroy_unres(mrt, c);
 669        }
 670
 671        if (!list_empty(&mrt->mfc_unres_queue))
 672                mod_timer(&mrt->ipmr_expire_timer, jiffies + expires);
 673
 674out:
 675        spin_unlock(&mfc_unres_lock);
 676}
 677
 678/* Fill oifs list. It is called under write locked mrt_lock. */
 679
 680static void ipmr_update_thresholds(struct mr_table *mrt, struct mfc_cache *cache,
 681                                   unsigned char *ttls)
 682{
 683        int vifi;
 684
 685        cache->mfc_un.res.minvif = MAXVIFS;
 686        cache->mfc_un.res.maxvif = 0;
 687        memset(cache->mfc_un.res.ttls, 255, MAXVIFS);
 688
 689        for (vifi = 0; vifi < mrt->maxvif; vifi++) {
 690                if (VIF_EXISTS(mrt, vifi) &&
 691                    ttls[vifi] && ttls[vifi] < 255) {
 692                        cache->mfc_un.res.ttls[vifi] = ttls[vifi];
 693                        if (cache->mfc_un.res.minvif > vifi)
 694                                cache->mfc_un.res.minvif = vifi;
 695                        if (cache->mfc_un.res.maxvif <= vifi)
 696                                cache->mfc_un.res.maxvif = vifi + 1;
 697                }
 698        }
 699}
 700
 701static int vif_add(struct net *net, struct mr_table *mrt,
 702                   struct vifctl *vifc, int mrtsock)
 703{
 704        int vifi = vifc->vifc_vifi;
 705        struct vif_device *v = &mrt->vif_table[vifi];
 706        struct net_device *dev;
 707        struct in_device *in_dev;
 708        int err;
 709
 710        /* Is vif busy ? */
 711        if (VIF_EXISTS(mrt, vifi))
 712                return -EADDRINUSE;
 713
 714        switch (vifc->vifc_flags) {
 715#ifdef CONFIG_IP_PIMSM
 716        case VIFF_REGISTER:
 717                /*
 718                 * Special Purpose VIF in PIM
 719                 * All the packets will be sent to the daemon
 720                 */
 721                if (mrt->mroute_reg_vif_num >= 0)
 722                        return -EADDRINUSE;
 723                dev = ipmr_reg_vif(net, mrt);
 724                if (!dev)
 725                        return -ENOBUFS;
 726                err = dev_set_allmulti(dev, 1);
 727                if (err) {
 728                        unregister_netdevice(dev);
 729                        dev_put(dev);
 730                        return err;
 731                }
 732                break;
 733#endif
 734        case VIFF_TUNNEL:
 735                dev = ipmr_new_tunnel(net, vifc);
 736                if (!dev)
 737                        return -ENOBUFS;
 738                err = dev_set_allmulti(dev, 1);
 739                if (err) {
 740                        ipmr_del_tunnel(dev, vifc);
 741                        dev_put(dev);
 742                        return err;
 743                }
 744                break;
 745
 746        case VIFF_USE_IFINDEX:
 747        case 0:
 748                if (vifc->vifc_flags == VIFF_USE_IFINDEX) {
 749                        dev = dev_get_by_index(net, vifc->vifc_lcl_ifindex);
 750                        if (dev && __in_dev_get_rtnl(dev) == NULL) {
 751                                dev_put(dev);
 752                                return -EADDRNOTAVAIL;
 753                        }
 754                } else {
 755                        dev = ip_dev_find(net, vifc->vifc_lcl_addr.s_addr);
 756                }
 757                if (!dev)
 758                        return -EADDRNOTAVAIL;
 759                err = dev_set_allmulti(dev, 1);
 760                if (err) {
 761                        dev_put(dev);
 762                        return err;
 763                }
 764                break;
 765        default:
 766                return -EINVAL;
 767        }
 768
 769        in_dev = __in_dev_get_rtnl(dev);
 770        if (!in_dev) {
 771                dev_put(dev);
 772                return -EADDRNOTAVAIL;
 773        }
 774        IPV4_DEVCONF(in_dev->cnf, MC_FORWARDING)++;
 775        ip_rt_multicast_event(in_dev);
 776
 777        /* Fill in the VIF structures */
 778
 779        v->rate_limit = vifc->vifc_rate_limit;
 780        v->local = vifc->vifc_lcl_addr.s_addr;
 781        v->remote = vifc->vifc_rmt_addr.s_addr;
 782        v->flags = vifc->vifc_flags;
 783        if (!mrtsock)
 784                v->flags |= VIFF_STATIC;
 785        v->threshold = vifc->vifc_threshold;
 786        v->bytes_in = 0;
 787        v->bytes_out = 0;
 788        v->pkt_in = 0;
 789        v->pkt_out = 0;
 790        v->link = dev->ifindex;
 791        if (v->flags & (VIFF_TUNNEL | VIFF_REGISTER))
 792                v->link = dev->iflink;
 793
 794        /* And finish update writing critical data */
 795        write_lock_bh(&mrt_lock);
 796        v->dev = dev;
 797#ifdef CONFIG_IP_PIMSM
 798        if (v->flags & VIFF_REGISTER)
 799                mrt->mroute_reg_vif_num = vifi;
 800#endif
 801        if (vifi+1 > mrt->maxvif)
 802                mrt->maxvif = vifi+1;
 803        write_unlock_bh(&mrt_lock);
 804        return 0;
 805}
 806
 807/* called with rcu_read_lock() */
 808static struct mfc_cache *ipmr_cache_find(struct mr_table *mrt,
 809                                         __be32 origin,
 810                                         __be32 mcastgrp)
 811{
 812        int line = MFC_HASH(mcastgrp, origin);
 813        struct mfc_cache *c;
 814
 815        list_for_each_entry_rcu(c, &mrt->mfc_cache_array[line], list) {
 816                if (c->mfc_origin == origin && c->mfc_mcastgrp == mcastgrp)
 817                        return c;
 818        }
 819        return NULL;
 820}
 821
 822/*
 823 *      Allocate a multicast cache entry
 824 */
 825static struct mfc_cache *ipmr_cache_alloc(void)
 826{
 827        struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_KERNEL);
 828
 829        if (c)
 830                c->mfc_un.res.minvif = MAXVIFS;
 831        return c;
 832}
 833
 834static struct mfc_cache *ipmr_cache_alloc_unres(void)
 835{
 836        struct mfc_cache *c = kmem_cache_zalloc(mrt_cachep, GFP_ATOMIC);
 837
 838        if (c) {
 839                skb_queue_head_init(&c->mfc_un.unres.unresolved);
 840                c->mfc_un.unres.expires = jiffies + 10*HZ;
 841        }
 842        return c;
 843}
 844
 845/*
 846 *      A cache entry has gone into a resolved state from queued
 847 */
 848
 849static void ipmr_cache_resolve(struct net *net, struct mr_table *mrt,
 850                               struct mfc_cache *uc, struct mfc_cache *c)
 851{
 852        struct sk_buff *skb;
 853        struct nlmsgerr *e;
 854
 855        /* Play the pending entries through our router */
 856
 857        while ((skb = __skb_dequeue(&uc->mfc_un.unres.unresolved))) {
 858                if (ip_hdr(skb)->version == 0) {
 859                        struct nlmsghdr *nlh = (struct nlmsghdr *)skb_pull(skb, sizeof(struct iphdr));
 860
 861                        if (__ipmr_fill_mroute(mrt, skb, c, NLMSG_DATA(nlh)) > 0) {
 862                                nlh->nlmsg_len = skb_tail_pointer(skb) -
 863                                                 (u8 *)nlh;
 864                        } else {
 865                                nlh->nlmsg_type = NLMSG_ERROR;
 866                                nlh->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
 867                                skb_trim(skb, nlh->nlmsg_len);
 868                                e = NLMSG_DATA(nlh);
 869                                e->error = -EMSGSIZE;
 870                                memset(&e->msg, 0, sizeof(e->msg));
 871                        }
 872
 873                        rtnl_unicast(skb, net, NETLINK_CB(skb).pid);
 874                } else {
 875                        ip_mr_forward(net, mrt, skb, c, 0);
 876                }
 877        }
 878}
 879
 880/*
 881 *      Bounce a cache query up to mrouted. We could use netlink for this but mrouted
 882 *      expects the following bizarre scheme.
 883 *
 884 *      Called under mrt_lock.
 885 */
 886
 887static int ipmr_cache_report(struct mr_table *mrt,
 888                             struct sk_buff *pkt, vifi_t vifi, int assert)
 889{
 890        struct sk_buff *skb;
 891        const int ihl = ip_hdrlen(pkt);
 892        struct igmphdr *igmp;
 893        struct igmpmsg *msg;
 894        struct sock *mroute_sk;
 895        int ret;
 896
 897#ifdef CONFIG_IP_PIMSM
 898        if (assert == IGMPMSG_WHOLEPKT)
 899                skb = skb_realloc_headroom(pkt, sizeof(struct iphdr));
 900        else
 901#endif
 902                skb = alloc_skb(128, GFP_ATOMIC);
 903
 904        if (!skb)
 905                return -ENOBUFS;
 906
 907#ifdef CONFIG_IP_PIMSM
 908        if (assert == IGMPMSG_WHOLEPKT) {
 909                /* Ugly, but we have no choice with this interface.
 910                 * Duplicate old header, fix ihl, length etc.
 911                 * And all this only to mangle msg->im_msgtype and
 912                 * to set msg->im_mbz to "mbz" :-)
 913                 */
 914                skb_push(skb, sizeof(struct iphdr));
 915                skb_reset_network_header(skb);
 916                skb_reset_transport_header(skb);
 917                msg = (struct igmpmsg *)skb_network_header(skb);
 918                memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));
 919                msg->im_msgtype = IGMPMSG_WHOLEPKT;
 920                msg->im_mbz = 0;
 921                msg->im_vif = mrt->mroute_reg_vif_num;
 922                ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;
 923                ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +
 924                                             sizeof(struct iphdr));
 925        } else
 926#endif
 927        {
 928
 929        /* Copy the IP header */
 930
 931        skb->network_header = skb->tail;
 932        skb_put(skb, ihl);
 933        skb_copy_to_linear_data(skb, pkt->data, ihl);
 934        ip_hdr(skb)->protocol = 0;      /* Flag to the kernel this is a route add */
 935        msg = (struct igmpmsg *)skb_network_header(skb);
 936        msg->im_vif = vifi;
 937        skb_dst_set(skb, dst_clone(skb_dst(pkt)));
 938
 939        /* Add our header */
 940
 941        igmp = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
 942        igmp->type      =
 943        msg->im_msgtype = assert;
 944        igmp->code      = 0;
 945        ip_hdr(skb)->tot_len = htons(skb->len);         /* Fix the length */
 946        skb->transport_header = skb->network_header;
 947        }
 948
 949        rcu_read_lock();
 950        mroute_sk = rcu_dereference(mrt->mroute_sk);
 951        if (mroute_sk == NULL) {
 952                rcu_read_unlock();
 953                kfree_skb(skb);
 954                return -EINVAL;
 955        }
 956
 957        /* Deliver to mrouted */
 958
 959        ret = sock_queue_rcv_skb(mroute_sk, skb);
 960        rcu_read_unlock();
 961        if (ret < 0) {
 962                net_warn_ratelimited("mroute: pending queue full, dropping entries\n");
 963                kfree_skb(skb);
 964        }
 965
 966        return ret;
 967}
 968
 969/*
 970 *      Queue a packet for resolution. It gets locked cache entry!
 971 */
 972
 973static int
 974ipmr_cache_unresolved(struct mr_table *mrt, vifi_t vifi, struct sk_buff *skb)
 975{
 976        bool found = false;
 977        int err;
 978        struct mfc_cache *c;
 979        const struct iphdr *iph = ip_hdr(skb);
 980
 981        spin_lock_bh(&mfc_unres_lock);
 982        list_for_each_entry(c, &mrt->mfc_unres_queue, list) {
 983                if (c->mfc_mcastgrp == iph->daddr &&
 984                    c->mfc_origin == iph->saddr) {
 985                        found = true;
 986                        break;
 987                }
 988        }
 989
 990        if (!found) {
 991                /* Create a new entry if allowable */
 992
 993                if (atomic_read(&mrt->cache_resolve_queue_len) >= 10 ||
 994                    (c = ipmr_cache_alloc_unres()) == NULL) {
 995                        spin_unlock_bh(&mfc_unres_lock);
 996
 997                        kfree_skb(skb);
 998                        return -ENOBUFS;
 999                }
1000
1001                /* Fill in the new cache entry */
1002
1003                c->mfc_parent   = -1;
1004                c->mfc_origin   = iph->saddr;
1005                c->mfc_mcastgrp = iph->daddr;
1006
1007                /* Reflect first query at mrouted. */
1008
1009                err = ipmr_cache_report(mrt, skb, vifi, IGMPMSG_NOCACHE);
1010                if (err < 0) {
1011                        /* If the report failed throw the cache entry
1012                           out - Brad Parker
1013                         */
1014                        spin_unlock_bh(&mfc_unres_lock);
1015
1016                        ipmr_cache_free(c);
1017                        kfree_skb(skb);
1018                        return err;
1019                }
1020
1021                atomic_inc(&mrt->cache_resolve_queue_len);
1022                list_add(&c->list, &mrt->mfc_unres_queue);
1023
1024                if (atomic_read(&mrt->cache_resolve_queue_len) == 1)
1025                        mod_timer(&mrt->ipmr_expire_timer, c->mfc_un.unres.expires);
1026        }
1027
1028        /* See if we can append the packet */
1029
1030        if (c->mfc_un.unres.unresolved.qlen > 3) {
1031                kfree_skb(skb);
1032                err = -ENOBUFS;
1033        } else {
1034                skb_queue_tail(&c->mfc_un.unres.unresolved, skb);
1035                err = 0;
1036        }
1037
1038        spin_unlock_bh(&mfc_unres_lock);
1039        return err;
1040}
1041
1042/*
1043 *      MFC cache manipulation by user space mroute daemon
1044 */
1045
1046static int ipmr_mfc_delete(struct mr_table *mrt, struct mfcctl *mfc)
1047{
1048        int line;
1049        struct mfc_cache *c, *next;
1050
1051        line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1052
1053        list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[line], list) {
1054                if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1055                    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
1056                        list_del_rcu(&c->list);
1057
1058                        ipmr_cache_free(c);
1059                        return 0;
1060                }
1061        }
1062        return -ENOENT;
1063}
1064
1065static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
1066                        struct mfcctl *mfc, int mrtsock)
1067{
1068        bool found = false;
1069        int line;
1070        struct mfc_cache *uc, *c;
1071
1072        if (mfc->mfcc_parent >= MAXVIFS)
1073                return -ENFILE;
1074
1075        line = MFC_HASH(mfc->mfcc_mcastgrp.s_addr, mfc->mfcc_origin.s_addr);
1076
1077        list_for_each_entry(c, &mrt->mfc_cache_array[line], list) {
1078                if (c->mfc_origin == mfc->mfcc_origin.s_addr &&
1079                    c->mfc_mcastgrp == mfc->mfcc_mcastgrp.s_addr) {
1080                        found = true;
1081                        break;
1082                }
1083        }
1084
1085        if (found) {
1086                write_lock_bh(&mrt_lock);
1087                c->mfc_parent = mfc->mfcc_parent;
1088                ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1089                if (!mrtsock)
1090                        c->mfc_flags |= MFC_STATIC;
1091                write_unlock_bh(&mrt_lock);
1092                return 0;
1093        }
1094
1095        if (!ipv4_is_multicast(mfc->mfcc_mcastgrp.s_addr))
1096                return -EINVAL;
1097
1098        c = ipmr_cache_alloc();
1099        if (c == NULL)
1100                return -ENOMEM;
1101
1102        c->mfc_origin = mfc->mfcc_origin.s_addr;
1103        c->mfc_mcastgrp = mfc->mfcc_mcastgrp.s_addr;
1104        c->mfc_parent = mfc->mfcc_parent;
1105        ipmr_update_thresholds(mrt, c, mfc->mfcc_ttls);
1106        if (!mrtsock)
1107                c->mfc_flags |= MFC_STATIC;
1108
1109        list_add_rcu(&c->list, &mrt->mfc_cache_array[line]);
1110
1111        /*
1112         *      Check to see if we resolved a queued list. If so we
1113         *      need to send on the frames and tidy up.
1114         */
1115        found = false;
1116        spin_lock_bh(&mfc_unres_lock);
1117        list_for_each_entry(uc, &mrt->mfc_unres_queue, list) {
1118                if (uc->mfc_origin == c->mfc_origin &&
1119                    uc->mfc_mcastgrp == c->mfc_mcastgrp) {
1120                        list_del(&uc->list);
1121                        atomic_dec(&mrt->cache_resolve_queue_len);
1122                        found = true;
1123                        break;
1124                }
1125        }
1126        if (list_empty(&mrt->mfc_unres_queue))
1127                del_timer(&mrt->ipmr_expire_timer);
1128        spin_unlock_bh(&mfc_unres_lock);
1129
1130        if (found) {
1131                ipmr_cache_resolve(net, mrt, uc, c);
1132                ipmr_cache_free(uc);
1133        }
1134        return 0;
1135}
1136
1137/*
1138 *      Close the multicast socket, and clear the vif tables etc
1139 */
1140
1141static void mroute_clean_tables(struct mr_table *mrt)
1142{
1143        int i;
1144        LIST_HEAD(list);
1145        struct mfc_cache *c, *next;
1146
1147        /* Shut down all active vif entries */
1148
1149        for (i = 0; i < mrt->maxvif; i++) {
1150                if (!(mrt->vif_table[i].flags & VIFF_STATIC))
1151                        vif_delete(mrt, i, 0, &list);
1152        }
1153        unregister_netdevice_many(&list);
1154
1155        /* Wipe the cache */
1156
1157        for (i = 0; i < MFC_LINES; i++) {
1158                list_for_each_entry_safe(c, next, &mrt->mfc_cache_array[i], list) {
1159                        if (c->mfc_flags & MFC_STATIC)
1160                                continue;
1161                        list_del_rcu(&c->list);
1162                        ipmr_cache_free(c);
1163                }
1164        }
1165
1166        if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
1167                spin_lock_bh(&mfc_unres_lock);
1168                list_for_each_entry_safe(c, next, &mrt->mfc_unres_queue, list) {
1169                        list_del(&c->list);
1170                        ipmr_destroy_unres(mrt, c);
1171                }
1172                spin_unlock_bh(&mfc_unres_lock);
1173        }
1174}
1175
1176/* called from ip_ra_control(), before an RCU grace period,
1177 * we dont need to call synchronize_rcu() here
1178 */
1179static void mrtsock_destruct(struct sock *sk)
1180{
1181        struct net *net = sock_net(sk);
1182        struct mr_table *mrt;
1183
1184        rtnl_lock();
1185        ipmr_for_each_table(mrt, net) {
1186                if (sk == rtnl_dereference(mrt->mroute_sk)) {
1187                        IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
1188                        RCU_INIT_POINTER(mrt->mroute_sk, NULL);
1189                        mroute_clean_tables(mrt);
1190                }
1191        }
1192        rtnl_unlock();
1193}
1194
1195/*
1196 *      Socket options and virtual interface manipulation. The whole
1197 *      virtual interface system is a complete heap, but unfortunately
1198 *      that's how BSD mrouted happens to think. Maybe one day with a proper
1199 *      MOSPF/PIM router set up we can clean this up.
1200 */
1201
1202int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen)
1203{
1204        int ret;
1205        struct vifctl vif;
1206        struct mfcctl mfc;
1207        struct net *net = sock_net(sk);
1208        struct mr_table *mrt;
1209
1210        mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1211        if (mrt == NULL)
1212                return -ENOENT;
1213
1214        if (optname != MRT_INIT) {
1215                if (sk != rcu_access_pointer(mrt->mroute_sk) &&
1216                    !capable(CAP_NET_ADMIN))
1217                        return -EACCES;
1218        }
1219
1220        switch (optname) {
1221        case MRT_INIT:
1222                if (sk->sk_type != SOCK_RAW ||
1223                    inet_sk(sk)->inet_num != IPPROTO_IGMP)
1224                        return -EOPNOTSUPP;
1225                if (optlen != sizeof(int))
1226                        return -ENOPROTOOPT;
1227
1228                rtnl_lock();
1229                if (rtnl_dereference(mrt->mroute_sk)) {
1230                        rtnl_unlock();
1231                        return -EADDRINUSE;
1232                }
1233
1234                ret = ip_ra_control(sk, 1, mrtsock_destruct);
1235                if (ret == 0) {
1236                        rcu_assign_pointer(mrt->mroute_sk, sk);
1237                        IPV4_DEVCONF_ALL(net, MC_FORWARDING)++;
1238                }
1239                rtnl_unlock();
1240                return ret;
1241        case MRT_DONE:
1242                if (sk != rcu_access_pointer(mrt->mroute_sk))
1243                        return -EACCES;
1244                return ip_ra_control(sk, 0, NULL);
1245        case MRT_ADD_VIF:
1246        case MRT_DEL_VIF:
1247                if (optlen != sizeof(vif))
1248                        return -EINVAL;
1249                if (copy_from_user(&vif, optval, sizeof(vif)))
1250                        return -EFAULT;
1251                if (vif.vifc_vifi >= MAXVIFS)
1252                        return -ENFILE;
1253                rtnl_lock();
1254                if (optname == MRT_ADD_VIF) {
1255                        ret = vif_add(net, mrt, &vif,
1256                                      sk == rtnl_dereference(mrt->mroute_sk));
1257                } else {
1258                        ret = vif_delete(mrt, vif.vifc_vifi, 0, NULL);
1259                }
1260                rtnl_unlock();
1261                return ret;
1262
1263                /*
1264                 *      Manipulate the forwarding caches. These live
1265                 *      in a sort of kernel/user symbiosis.
1266                 */
1267        case MRT_ADD_MFC:
1268        case MRT_DEL_MFC:
1269                if (optlen != sizeof(mfc))
1270                        return -EINVAL;
1271                if (copy_from_user(&mfc, optval, sizeof(mfc)))
1272                        return -EFAULT;
1273                rtnl_lock();
1274                if (optname == MRT_DEL_MFC)
1275                        ret = ipmr_mfc_delete(mrt, &mfc);
1276                else
1277                        ret = ipmr_mfc_add(net, mrt, &mfc,
1278                                           sk == rtnl_dereference(mrt->mroute_sk));
1279                rtnl_unlock();
1280                return ret;
1281                /*
1282                 *      Control PIM assert.
1283                 */
1284        case MRT_ASSERT:
1285        {
1286                int v;
1287                if (get_user(v, (int __user *)optval))
1288                        return -EFAULT;
1289                mrt->mroute_do_assert = (v) ? 1 : 0;
1290                return 0;
1291        }
1292#ifdef CONFIG_IP_PIMSM
1293        case MRT_PIM:
1294        {
1295                int v;
1296
1297                if (get_user(v, (int __user *)optval))
1298                        return -EFAULT;
1299                v = (v) ? 1 : 0;
1300
1301                rtnl_lock();
1302                ret = 0;
1303                if (v != mrt->mroute_do_pim) {
1304                        mrt->mroute_do_pim = v;
1305                        mrt->mroute_do_assert = v;
1306                }
1307                rtnl_unlock();
1308                return ret;
1309        }
1310#endif
1311#ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
1312        case MRT_TABLE:
1313        {
1314                u32 v;
1315
1316                if (optlen != sizeof(u32))
1317                        return -EINVAL;
1318                if (get_user(v, (u32 __user *)optval))
1319                        return -EFAULT;
1320
1321                rtnl_lock();
1322                ret = 0;
1323                if (sk == rtnl_dereference(mrt->mroute_sk)) {
1324                        ret = -EBUSY;
1325                } else {
1326                        if (!ipmr_new_table(net, v))
1327                                ret = -ENOMEM;
1328                        raw_sk(sk)->ipmr_table = v;
1329                }
1330                rtnl_unlock();
1331                return ret;
1332        }
1333#endif
1334        /*
1335         *      Spurious command, or MRT_VERSION which you cannot
1336         *      set.
1337         */
1338        default:
1339                return -ENOPROTOOPT;
1340        }
1341}
1342
1343/*
1344 *      Getsock opt support for the multicast routing system.
1345 */
1346
1347int ip_mroute_getsockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen)
1348{
1349        int olr;
1350        int val;
1351        struct net *net = sock_net(sk);
1352        struct mr_table *mrt;
1353
1354        mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1355        if (mrt == NULL)
1356                return -ENOENT;
1357
1358        if (optname != MRT_VERSION &&
1359#ifdef CONFIG_IP_PIMSM
1360           optname != MRT_PIM &&
1361#endif
1362           optname != MRT_ASSERT)
1363                return -ENOPROTOOPT;
1364
1365        if (get_user(olr, optlen))
1366                return -EFAULT;
1367
1368        olr = min_t(unsigned int, olr, sizeof(int));
1369        if (olr < 0)
1370                return -EINVAL;
1371
1372        if (put_user(olr, optlen))
1373                return -EFAULT;
1374        if (optname == MRT_VERSION)
1375                val = 0x0305;
1376#ifdef CONFIG_IP_PIMSM
1377        else if (optname == MRT_PIM)
1378                val = mrt->mroute_do_pim;
1379#endif
1380        else
1381                val = mrt->mroute_do_assert;
1382        if (copy_to_user(optval, &val, olr))
1383                return -EFAULT;
1384        return 0;
1385}
1386
1387/*
1388 *      The IP multicast ioctl support routines.
1389 */
1390
1391int ipmr_ioctl(struct sock *sk, int cmd, void __user *arg)
1392{
1393        struct sioc_sg_req sr;
1394        struct sioc_vif_req vr;
1395        struct vif_device *vif;
1396        struct mfc_cache *c;
1397        struct net *net = sock_net(sk);
1398        struct mr_table *mrt;
1399
1400        mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1401        if (mrt == NULL)
1402                return -ENOENT;
1403
1404        switch (cmd) {
1405        case SIOCGETVIFCNT:
1406                if (copy_from_user(&vr, arg, sizeof(vr)))
1407                        return -EFAULT;
1408                if (vr.vifi >= mrt->maxvif)
1409                        return -EINVAL;
1410                read_lock(&mrt_lock);
1411                vif = &mrt->vif_table[vr.vifi];
1412                if (VIF_EXISTS(mrt, vr.vifi)) {
1413                        vr.icount = vif->pkt_in;
1414                        vr.ocount = vif->pkt_out;
1415                        vr.ibytes = vif->bytes_in;
1416                        vr.obytes = vif->bytes_out;
1417                        read_unlock(&mrt_lock);
1418
1419                        if (copy_to_user(arg, &vr, sizeof(vr)))
1420                                return -EFAULT;
1421                        return 0;
1422                }
1423                read_unlock(&mrt_lock);
1424                return -EADDRNOTAVAIL;
1425        case SIOCGETSGCNT:
1426                if (copy_from_user(&sr, arg, sizeof(sr)))
1427                        return -EFAULT;
1428
1429                rcu_read_lock();
1430                c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1431                if (c) {
1432                        sr.pktcnt = c->mfc_un.res.pkt;
1433                        sr.bytecnt = c->mfc_un.res.bytes;
1434                        sr.wrong_if = c->mfc_un.res.wrong_if;
1435                        rcu_read_unlock();
1436
1437                        if (copy_to_user(arg, &sr, sizeof(sr)))
1438                                return -EFAULT;
1439                        return 0;
1440                }
1441                rcu_read_unlock();
1442                return -EADDRNOTAVAIL;
1443        default:
1444                return -ENOIOCTLCMD;
1445        }
1446}
1447
1448#ifdef CONFIG_COMPAT
1449struct compat_sioc_sg_req {
1450        struct in_addr src;
1451        struct in_addr grp;
1452        compat_ulong_t pktcnt;
1453        compat_ulong_t bytecnt;
1454        compat_ulong_t wrong_if;
1455};
1456
1457struct compat_sioc_vif_req {
1458        vifi_t  vifi;           /* Which iface */
1459        compat_ulong_t icount;
1460        compat_ulong_t ocount;
1461        compat_ulong_t ibytes;
1462        compat_ulong_t obytes;
1463};
1464
1465int ipmr_compat_ioctl(struct sock *sk, unsigned int cmd, void __user *arg)
1466{
1467        struct compat_sioc_sg_req sr;
1468        struct compat_sioc_vif_req vr;
1469        struct vif_device *vif;
1470        struct mfc_cache *c;
1471        struct net *net = sock_net(sk);
1472        struct mr_table *mrt;
1473
1474        mrt = ipmr_get_table(net, raw_sk(sk)->ipmr_table ? : RT_TABLE_DEFAULT);
1475        if (mrt == NULL)
1476                return -ENOENT;
1477
1478        switch (cmd) {
1479        case SIOCGETVIFCNT:
1480                if (copy_from_user(&vr, arg, sizeof(vr)))
1481                        return -EFAULT;
1482                if (vr.vifi >= mrt->maxvif)
1483                        return -EINVAL;
1484                read_lock(&mrt_lock);
1485                vif = &mrt->vif_table[vr.vifi];
1486                if (VIF_EXISTS(mrt, vr.vifi)) {
1487                        vr.icount = vif->pkt_in;
1488                        vr.ocount = vif->pkt_out;
1489                        vr.ibytes = vif->bytes_in;
1490                        vr.obytes = vif->bytes_out;
1491                        read_unlock(&mrt_lock);
1492
1493                        if (copy_to_user(arg, &vr, sizeof(vr)))
1494                                return -EFAULT;
1495                        return 0;
1496                }
1497                read_unlock(&mrt_lock);
1498                return -EADDRNOTAVAIL;
1499        case SIOCGETSGCNT:
1500                if (copy_from_user(&sr, arg, sizeof(sr)))
1501                        return -EFAULT;
1502
1503                rcu_read_lock();
1504                c = ipmr_cache_find(mrt, sr.src.s_addr, sr.grp.s_addr);
1505                if (c) {
1506                        sr.pktcnt = c->mfc_un.res.pkt;
1507                        sr.bytecnt = c->mfc_un.res.bytes;
1508                        sr.wrong_if = c->mfc_un.res.wrong_if;
1509                        rcu_read_unlock();
1510
1511                        if (copy_to_user(arg, &sr, sizeof(sr)))
1512                                return -EFAULT;
1513                        return 0;
1514                }
1515                rcu_read_unlock();
1516                return -EADDRNOTAVAIL;
1517        default:
1518                return -ENOIOCTLCMD;
1519        }
1520}
1521#endif
1522
1523
1524static int ipmr_device_event(struct notifier_block *this, unsigned long event, void *ptr)
1525{
1526        struct net_device *dev = ptr;
1527        struct net *net = dev_net(dev);
1528        struct mr_table *mrt;
1529        struct vif_device *v;
1530        int ct;
1531
1532        if (event != NETDEV_UNREGISTER)
1533                return NOTIFY_DONE;
1534
1535        ipmr_for_each_table(mrt, net) {
1536                v = &mrt->vif_table[0];
1537                for (ct = 0; ct < mrt->maxvif; ct++, v++) {
1538                        if (v->dev == dev)
1539                                vif_delete(mrt, ct, 1, NULL);
1540                }
1541        }
1542        return NOTIFY_DONE;
1543}
1544
1545
1546static struct notifier_block ip_mr_notifier = {
1547        .notifier_call = ipmr_device_event,
1548};
1549
1550/*
1551 *      Encapsulate a packet by attaching a valid IPIP header to it.
1552 *      This avoids tunnel drivers and other mess and gives us the speed so
1553 *      important for multicast video.
1554 */
1555
1556static void ip_encap(struct sk_buff *skb, __be32 saddr, __be32 daddr)
1557{
1558        struct iphdr *iph;
1559        const struct iphdr *old_iph = ip_hdr(skb);
1560
1561        skb_push(skb, sizeof(struct iphdr));
1562        skb->transport_header = skb->network_header;
1563        skb_reset_network_header(skb);
1564        iph = ip_hdr(skb);
1565
1566        iph->version    =       4;
1567        iph->tos        =       old_iph->tos;
1568        iph->ttl        =       old_iph->ttl;
1569        iph->frag_off   =       0;
1570        iph->daddr      =       daddr;
1571        iph->saddr      =       saddr;
1572        iph->protocol   =       IPPROTO_IPIP;
1573        iph->ihl        =       5;
1574        iph->tot_len    =       htons(skb->len);
1575        ip_select_ident(iph, skb_dst(skb), NULL);
1576        ip_send_check(iph);
1577
1578        memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1579        nf_reset(skb);
1580}
1581
1582static inline int ipmr_forward_finish(struct sk_buff *skb)
1583{
1584        struct ip_options *opt = &(IPCB(skb)->opt);
1585
1586        IP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTFORWDATAGRAMS);
1587        IP_ADD_STATS_BH(dev_net(skb_dst(skb)->dev), IPSTATS_MIB_OUTOCTETS, skb->len);
1588
1589        if (unlikely(opt->optlen))
1590                ip_forward_options(skb);
1591
1592        return dst_output(skb);
1593}
1594
1595/*
1596 *      Processing handlers for ipmr_forward
1597 */
1598
1599static void ipmr_queue_xmit(struct net *net, struct mr_table *mrt,
1600                            struct sk_buff *skb, struct mfc_cache *c, int vifi)
1601{
1602        const struct iphdr *iph = ip_hdr(skb);
1603        struct vif_device *vif = &mrt->vif_table[vifi];
1604        struct net_device *dev;
1605        struct rtable *rt;
1606        struct flowi4 fl4;
1607        int    encap = 0;
1608
1609        if (vif->dev == NULL)
1610                goto out_free;
1611
1612#ifdef CONFIG_IP_PIMSM
1613        if (vif->flags & VIFF_REGISTER) {
1614                vif->pkt_out++;
1615                vif->bytes_out += skb->len;
1616                vif->dev->stats.tx_bytes += skb->len;
1617                vif->dev->stats.tx_packets++;
1618                ipmr_cache_report(mrt, skb, vifi, IGMPMSG_WHOLEPKT);
1619                goto out_free;
1620        }
1621#endif
1622
1623        if (vif->flags & VIFF_TUNNEL) {
1624                rt = ip_route_output_ports(net, &fl4, NULL,
1625                                           vif->remote, vif->local,
1626                                           0, 0,
1627                                           IPPROTO_IPIP,
1628                                           RT_TOS(iph->tos), vif->link);
1629                if (IS_ERR(rt))
1630                        goto out_free;
1631                encap = sizeof(struct iphdr);
1632        } else {
1633                rt = ip_route_output_ports(net, &fl4, NULL, iph->daddr, 0,
1634                                           0, 0,
1635                                           IPPROTO_IPIP,
1636                                           RT_TOS(iph->tos), vif->link);
1637                if (IS_ERR(rt))
1638                        goto out_free;
1639        }
1640
1641        dev = rt->dst.dev;
1642
1643        if (skb->len+encap > dst_mtu(&rt->dst) && (ntohs(iph->frag_off) & IP_DF)) {
1644                /* Do not fragment multicasts. Alas, IPv4 does not
1645                 * allow to send ICMP, so that packets will disappear
1646                 * to blackhole.
1647                 */
1648
1649                IP_INC_STATS_BH(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
1650                ip_rt_put(rt);
1651                goto out_free;
1652        }
1653
1654        encap += LL_RESERVED_SPACE(dev) + rt->dst.header_len;
1655
1656        if (skb_cow(skb, encap)) {
1657                ip_rt_put(rt);
1658                goto out_free;
1659        }
1660
1661        vif->pkt_out++;
1662        vif->bytes_out += skb->len;
1663
1664        skb_dst_drop(skb);
1665        skb_dst_set(skb, &rt->dst);
1666        ip_decrease_ttl(ip_hdr(skb));
1667
1668        /* FIXME: forward and output firewalls used to be called here.
1669         * What do we do with netfilter? -- RR
1670         */
1671        if (vif->flags & VIFF_TUNNEL) {
1672                ip_encap(skb, vif->local, vif->remote);
1673                /* FIXME: extra output firewall step used to be here. --RR */
1674                vif->dev->stats.tx_packets++;
1675                vif->dev->stats.tx_bytes += skb->len;
1676        }
1677
1678        IPCB(skb)->flags |= IPSKB_FORWARDED;
1679
1680        /*
1681         * RFC1584 teaches, that DVMRP/PIM router must deliver packets locally
1682         * not only before forwarding, but after forwarding on all output
1683         * interfaces. It is clear, if mrouter runs a multicasting
1684         * program, it should receive packets not depending to what interface
1685         * program is joined.
1686         * If we will not make it, the program will have to join on all
1687         * interfaces. On the other hand, multihoming host (or router, but
1688         * not mrouter) cannot join to more than one interface - it will
1689         * result in receiving multiple packets.
1690         */
1691        NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, skb, skb->dev, dev,
1692                ipmr_forward_finish);
1693        return;
1694
1695out_free:
1696        kfree_skb(skb);
1697}
1698
1699static int ipmr_find_vif(struct mr_table *mrt, struct net_device *dev)
1700{
1701        int ct;
1702
1703        for (ct = mrt->maxvif-1; ct >= 0; ct--) {
1704                if (mrt->vif_table[ct].dev == dev)
1705                        break;
1706        }
1707        return ct;
1708}
1709
1710/* "local" means that we should preserve one skb (for local delivery) */
1711
1712static int ip_mr_forward(struct net *net, struct mr_table *mrt,
1713                         struct sk_buff *skb, struct mfc_cache *cache,
1714                         int local)
1715{
1716        int psend = -1;
1717        int vif, ct;
1718
1719        vif = cache->mfc_parent;
1720        cache->mfc_un.res.pkt++;
1721        cache->mfc_un.res.bytes += skb->len;
1722
1723        /*
1724         * Wrong interface: drop packet and (maybe) send PIM assert.
1725         */
1726        if (mrt->vif_table[vif].dev != skb->dev) {
1727                int true_vifi;
1728
1729                if (rt_is_output_route(skb_rtable(skb))) {
1730                        /* It is our own packet, looped back.
1731                         * Very complicated situation...
1732                         *
1733                         * The best workaround until routing daemons will be
1734                         * fixed is not to redistribute packet, if it was
1735                         * send through wrong interface. It means, that
1736                         * multicast applications WILL NOT work for
1737                         * (S,G), which have default multicast route pointing
1738                         * to wrong oif. In any case, it is not a good
1739                         * idea to use multicasting applications on router.
1740                         */
1741                        goto dont_forward;
1742                }
1743
1744                cache->mfc_un.res.wrong_if++;
1745                true_vifi = ipmr_find_vif(mrt, skb->dev);
1746
1747                if (true_vifi >= 0 && mrt->mroute_do_assert &&
1748                    /* pimsm uses asserts, when switching from RPT to SPT,
1749                     * so that we cannot check that packet arrived on an oif.
1750                     * It is bad, but otherwise we would need to move pretty
1751                     * large chunk of pimd to kernel. Ough... --ANK
1752                     */
1753                    (mrt->mroute_do_pim ||
1754                     cache->mfc_un.res.ttls[true_vifi] < 255) &&
1755                    time_after(jiffies,
1756                               cache->mfc_un.res.last_assert + MFC_ASSERT_THRESH)) {
1757                        cache->mfc_un.res.last_assert = jiffies;
1758                        ipmr_cache_report(mrt, skb, true_vifi, IGMPMSG_WRONGVIF);
1759                }
1760                goto dont_forward;
1761        }
1762
1763        mrt->vif_table[vif].pkt_in++;
1764        mrt->vif_table[vif].bytes_in += skb->len;
1765
1766        /*
1767         *      Forward the frame
1768         */
1769        for (ct = cache->mfc_un.res.maxvif - 1;
1770             ct >= cache->mfc_un.res.minvif; ct--) {
1771                if (ip_hdr(skb)->ttl > cache->mfc_un.res.ttls[ct]) {
1772                        if (psend != -1) {
1773                                struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1774
1775                                if (skb2)
1776                                        ipmr_queue_xmit(net, mrt, skb2, cache,
1777                                                        psend);
1778                        }
1779                        psend = ct;
1780                }
1781        }
1782        if (psend != -1) {
1783                if (local) {
1784                        struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1785
1786                        if (skb2)
1787                                ipmr_queue_xmit(net, mrt, skb2, cache, psend);
1788                } else {
1789                        ipmr_queue_xmit(net, mrt, skb, cache, psend);
1790                        return 0;
1791                }
1792        }
1793
1794dont_forward:
1795        if (!local)
1796                kfree_skb(skb);
1797        return 0;
1798}
1799
1800static struct mr_table *ipmr_rt_fib_lookup(struct net *net, struct sk_buff *skb)
1801{
1802        struct rtable *rt = skb_rtable(skb);
1803        struct iphdr *iph = ip_hdr(skb);
1804        struct flowi4 fl4 = {
1805                .daddr = iph->daddr,
1806                .saddr = iph->saddr,
1807                .flowi4_tos = RT_TOS(iph->tos),
1808                .flowi4_oif = (rt_is_output_route(rt) ?
1809                               skb->dev->ifindex : 0),
1810                .flowi4_iif = (rt_is_output_route(rt) ?
1811                               net->loopback_dev->ifindex :
1812                               skb->dev->ifindex),
1813                .flowi4_mark = skb->mark,
1814        };
1815        struct mr_table *mrt;
1816        int err;
1817
1818        err = ipmr_fib_lookup(net, &fl4, &mrt);
1819        if (err)
1820                return ERR_PTR(err);
1821        return mrt;
1822}
1823
1824/*
1825 *      Multicast packets for forwarding arrive here
1826 *      Called with rcu_read_lock();
1827 */
1828
1829int ip_mr_input(struct sk_buff *skb)
1830{
1831        struct mfc_cache *cache;
1832        struct net *net = dev_net(skb->dev);
1833        int local = skb_rtable(skb)->rt_flags & RTCF_LOCAL;
1834        struct mr_table *mrt;
1835
1836        /* Packet is looped back after forward, it should not be
1837         * forwarded second time, but still can be delivered locally.
1838         */
1839        if (IPCB(skb)->flags & IPSKB_FORWARDED)
1840                goto dont_forward;
1841
1842        mrt = ipmr_rt_fib_lookup(net, skb);
1843        if (IS_ERR(mrt)) {
1844                kfree_skb(skb);
1845                return PTR_ERR(mrt);
1846        }
1847        if (!local) {
1848                if (IPCB(skb)->opt.router_alert) {
1849                        if (ip_call_ra_chain(skb))
1850                                return 0;
1851                } else if (ip_hdr(skb)->protocol == IPPROTO_IGMP) {
1852                        /* IGMPv1 (and broken IGMPv2 implementations sort of
1853                         * Cisco IOS <= 11.2(8)) do not put router alert
1854                         * option to IGMP packets destined to routable
1855                         * groups. It is very bad, because it means
1856                         * that we can forward NO IGMP messages.
1857                         */
1858                        struct sock *mroute_sk;
1859
1860                        mroute_sk = rcu_dereference(mrt->mroute_sk);
1861                        if (mroute_sk) {
1862                                nf_reset(skb);
1863                                raw_rcv(mroute_sk, skb);
1864                                return 0;
1865                        }
1866                    }
1867        }
1868
1869        /* already under rcu_read_lock() */
1870        cache = ipmr_cache_find(mrt, ip_hdr(skb)->saddr, ip_hdr(skb)->daddr);
1871
1872        /*
1873         *      No usable cache entry
1874         */
1875        if (cache == NULL) {
1876                int vif;
1877
1878                if (local) {
1879                        struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1880                        ip_local_deliver(skb);
1881                        if (skb2 == NULL)
1882                                return -ENOBUFS;
1883                        skb = skb2;
1884                }
1885
1886                read_lock(&mrt_lock);
1887                vif = ipmr_find_vif(mrt, skb->dev);
1888                if (vif >= 0) {
1889                        int err2 = ipmr_cache_unresolved(mrt, vif, skb);
1890                        read_unlock(&mrt_lock);
1891
1892                        return err2;
1893                }
1894                read_unlock(&mrt_lock);
1895                kfree_skb(skb);
1896                return -ENODEV;
1897        }
1898
1899        read_lock(&mrt_lock);
1900        ip_mr_forward(net, mrt, skb, cache, local);
1901        read_unlock(&mrt_lock);
1902
1903        if (local)
1904                return ip_local_deliver(skb);
1905
1906        return 0;
1907
1908dont_forward:
1909        if (local)
1910                return ip_local_deliver(skb);
1911        kfree_skb(skb);
1912        return 0;
1913}
1914
1915#ifdef CONFIG_IP_PIMSM
1916/* called with rcu_read_lock() */
1917static int __pim_rcv(struct mr_table *mrt, struct sk_buff *skb,
1918                     unsigned int pimlen)
1919{
1920        struct net_device *reg_dev = NULL;
1921        struct iphdr *encap;
1922
1923        encap = (struct iphdr *)(skb_transport_header(skb) + pimlen);
1924        /*
1925         * Check that:
1926         * a. packet is really sent to a multicast group
1927         * b. packet is not a NULL-REGISTER
1928         * c. packet is not truncated
1929         */
1930        if (!ipv4_is_multicast(encap->daddr) ||
1931            encap->tot_len == 0 ||
1932            ntohs(encap->tot_len) + pimlen > skb->len)
1933                return 1;
1934
1935        read_lock(&mrt_lock);
1936        if (mrt->mroute_reg_vif_num >= 0)
1937                reg_dev = mrt->vif_table[mrt->mroute_reg_vif_num].dev;
1938        read_unlock(&mrt_lock);
1939
1940        if (reg_dev == NULL)
1941                return 1;
1942
1943        skb->mac_header = skb->network_header;
1944        skb_pull(skb, (u8 *)encap - skb->data);
1945        skb_reset_network_header(skb);
1946        skb->protocol = htons(ETH_P_IP);
1947        skb->ip_summed = CHECKSUM_NONE;
1948        skb->pkt_type = PACKET_HOST;
1949
1950        skb_tunnel_rx(skb, reg_dev);
1951
1952        netif_rx(skb);
1953
1954        return NET_RX_SUCCESS;
1955}
1956#endif
1957
1958#ifdef CONFIG_IP_PIMSM_V1
1959/*
1960 * Handle IGMP messages of PIMv1
1961 */
1962
1963int pim_rcv_v1(struct sk_buff *skb)
1964{
1965        struct igmphdr *pim;
1966        struct net *net = dev_net(skb->dev);
1967        struct mr_table *mrt;
1968
1969        if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
1970                goto drop;
1971
1972        pim = igmp_hdr(skb);
1973
1974        mrt = ipmr_rt_fib_lookup(net, skb);
1975        if (IS_ERR(mrt))
1976                goto drop;
1977        if (!mrt->mroute_do_pim ||
1978            pim->group != PIM_V1_VERSION || pim->code != PIM_V1_REGISTER)
1979                goto drop;
1980
1981        if (__pim_rcv(mrt, skb, sizeof(*pim))) {
1982drop:
1983                kfree_skb(skb);
1984        }
1985        return 0;
1986}
1987#endif
1988
1989#ifdef CONFIG_IP_PIMSM_V2
1990static int pim_rcv(struct sk_buff *skb)
1991{
1992        struct pimreghdr *pim;
1993        struct net *net = dev_net(skb->dev);
1994        struct mr_table *mrt;
1995
1996        if (!pskb_may_pull(skb, sizeof(*pim) + sizeof(struct iphdr)))
1997                goto drop;
1998
1999        pim = (struct pimreghdr *)skb_transport_header(skb);
2000        if (pim->type != ((PIM_VERSION << 4) | (PIM_REGISTER)) ||
2001            (pim->flags & PIM_NULL_REGISTER) ||
2002            (ip_compute_csum((void *)pim, sizeof(*pim)) != 0 &&
2003             csum_fold(skb_checksum(skb, 0, skb->len, 0))))
2004                goto drop;
2005
2006        mrt = ipmr_rt_fib_lookup(net, skb);
2007        if (IS_ERR(mrt))
2008                goto drop;
2009        if (__pim_rcv(mrt, skb, sizeof(*pim))) {
2010drop:
2011                kfree_skb(skb);
2012        }
2013        return 0;
2014}
2015#endif
2016
2017static int __ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2018                              struct mfc_cache *c, struct rtmsg *rtm)
2019{
2020        int ct;
2021        struct rtnexthop *nhp;
2022        struct nlattr *mp_attr;
2023
2024        /* If cache is unresolved, don't try to parse IIF and OIF */
2025        if (c->mfc_parent >= MAXVIFS)
2026                return -ENOENT;
2027
2028        if (VIF_EXISTS(mrt, c->mfc_parent) &&
2029            nla_put_u32(skb, RTA_IIF, mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
2030                return -EMSGSIZE;
2031
2032        if (!(mp_attr = nla_nest_start(skb, RTA_MULTIPATH)))
2033                return -EMSGSIZE;
2034
2035        for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
2036                if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
2037                        if (!(nhp = nla_reserve_nohdr(skb, sizeof(*nhp)))) {
2038                                nla_nest_cancel(skb, mp_attr);
2039                                return -EMSGSIZE;
2040                        }
2041
2042                        nhp->rtnh_flags = 0;
2043                        nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
2044                        nhp->rtnh_ifindex = mrt->vif_table[ct].dev->ifindex;
2045                        nhp->rtnh_len = sizeof(*nhp);
2046                }
2047        }
2048
2049        nla_nest_end(skb, mp_attr);
2050
2051        rtm->rtm_type = RTN_MULTICAST;
2052        return 1;
2053}
2054
2055int ipmr_get_route(struct net *net, struct sk_buff *skb,
2056                   __be32 saddr, __be32 daddr,
2057                   struct rtmsg *rtm, int nowait)
2058{
2059        struct mfc_cache *cache;
2060        struct mr_table *mrt;
2061        int err;
2062
2063        mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2064        if (mrt == NULL)
2065                return -ENOENT;
2066
2067        rcu_read_lock();
2068        cache = ipmr_cache_find(mrt, saddr, daddr);
2069
2070        if (cache == NULL) {
2071                struct sk_buff *skb2;
2072                struct iphdr *iph;
2073                struct net_device *dev;
2074                int vif = -1;
2075
2076                if (nowait) {
2077                        rcu_read_unlock();
2078                        return -EAGAIN;
2079                }
2080
2081                dev = skb->dev;
2082                read_lock(&mrt_lock);
2083                if (dev)
2084                        vif = ipmr_find_vif(mrt, dev);
2085                if (vif < 0) {
2086                        read_unlock(&mrt_lock);
2087                        rcu_read_unlock();
2088                        return -ENODEV;
2089                }
2090                skb2 = skb_clone(skb, GFP_ATOMIC);
2091                if (!skb2) {
2092                        read_unlock(&mrt_lock);
2093                        rcu_read_unlock();
2094                        return -ENOMEM;
2095                }
2096
2097                skb_push(skb2, sizeof(struct iphdr));
2098                skb_reset_network_header(skb2);
2099                iph = ip_hdr(skb2);
2100                iph->ihl = sizeof(struct iphdr) >> 2;
2101                iph->saddr = saddr;
2102                iph->daddr = daddr;
2103                iph->version = 0;
2104                err = ipmr_cache_unresolved(mrt, vif, skb2);
2105                read_unlock(&mrt_lock);
2106                rcu_read_unlock();
2107                return err;
2108        }
2109
2110        read_lock(&mrt_lock);
2111        if (!nowait && (rtm->rtm_flags & RTM_F_NOTIFY))
2112                cache->mfc_flags |= MFC_NOTIFY;
2113        err = __ipmr_fill_mroute(mrt, skb, cache, rtm);
2114        read_unlock(&mrt_lock);
2115        rcu_read_unlock();
2116        return err;
2117}
2118
2119static int ipmr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
2120                            u32 pid, u32 seq, struct mfc_cache *c)
2121{
2122        struct nlmsghdr *nlh;
2123        struct rtmsg *rtm;
2124
2125        nlh = nlmsg_put(skb, pid, seq, RTM_NEWROUTE, sizeof(*rtm), NLM_F_MULTI);
2126        if (nlh == NULL)
2127                return -EMSGSIZE;
2128
2129        rtm = nlmsg_data(nlh);
2130        rtm->rtm_family   = RTNL_FAMILY_IPMR;
2131        rtm->rtm_dst_len  = 32;
2132        rtm->rtm_src_len  = 32;
2133        rtm->rtm_tos      = 0;
2134        rtm->rtm_table    = mrt->id;
2135        if (nla_put_u32(skb, RTA_TABLE, mrt->id))
2136                goto nla_put_failure;
2137        rtm->rtm_type     = RTN_MULTICAST;
2138        rtm->rtm_scope    = RT_SCOPE_UNIVERSE;
2139        rtm->rtm_protocol = RTPROT_UNSPEC;
2140        rtm->rtm_flags    = 0;
2141
2142        if (nla_put_be32(skb, RTA_SRC, c->mfc_origin) ||
2143            nla_put_be32(skb, RTA_DST, c->mfc_mcastgrp))
2144                goto nla_put_failure;
2145        if (__ipmr_fill_mroute(mrt, skb, c, rtm) < 0)
2146                goto nla_put_failure;
2147
2148        return nlmsg_end(skb, nlh);
2149
2150nla_put_failure:
2151        nlmsg_cancel(skb, nlh);
2152        return -EMSGSIZE;
2153}
2154
2155static int ipmr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
2156{
2157        struct net *net = sock_net(skb->sk);
2158        struct mr_table *mrt;
2159        struct mfc_cache *mfc;
2160        unsigned int t = 0, s_t;
2161        unsigned int h = 0, s_h;
2162        unsigned int e = 0, s_e;
2163
2164        s_t = cb->args[0];
2165        s_h = cb->args[1];
2166        s_e = cb->args[2];
2167
2168        rcu_read_lock();
2169        ipmr_for_each_table(mrt, net) {
2170                if (t < s_t)
2171                        goto next_table;
2172                if (t > s_t)
2173                        s_h = 0;
2174                for (h = s_h; h < MFC_LINES; h++) {
2175                        list_for_each_entry_rcu(mfc, &mrt->mfc_cache_array[h], list) {
2176                                if (e < s_e)
2177                                        goto next_entry;
2178                                if (ipmr_fill_mroute(mrt, skb,
2179                                                     NETLINK_CB(cb->skb).pid,
2180                                                     cb->nlh->nlmsg_seq,
2181                                                     mfc) < 0)
2182                                        goto done;
2183next_entry:
2184                                e++;
2185                        }
2186                        e = s_e = 0;
2187                }
2188                s_h = 0;
2189next_table:
2190                t++;
2191        }
2192done:
2193        rcu_read_unlock();
2194
2195        cb->args[2] = e;
2196        cb->args[1] = h;
2197        cb->args[0] = t;
2198
2199        return skb->len;
2200}
2201
2202#ifdef CONFIG_PROC_FS
2203/*
2204 *      The /proc interfaces to multicast routing :
2205 *      /proc/net/ip_mr_cache & /proc/net/ip_mr_vif
2206 */
2207struct ipmr_vif_iter {
2208        struct seq_net_private p;
2209        struct mr_table *mrt;
2210        int ct;
2211};
2212
2213static struct vif_device *ipmr_vif_seq_idx(struct net *net,
2214                                           struct ipmr_vif_iter *iter,
2215                                           loff_t pos)
2216{
2217        struct mr_table *mrt = iter->mrt;
2218
2219        for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
2220                if (!VIF_EXISTS(mrt, iter->ct))
2221                        continue;
2222                if (pos-- == 0)
2223                        return &mrt->vif_table[iter->ct];
2224        }
2225        return NULL;
2226}
2227
2228static void *ipmr_vif_seq_start(struct seq_file *seq, loff_t *pos)
2229        __acquires(mrt_lock)
2230{
2231        struct ipmr_vif_iter *iter = seq->private;
2232        struct net *net = seq_file_net(seq);
2233        struct mr_table *mrt;
2234
2235        mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2236        if (mrt == NULL)
2237                return ERR_PTR(-ENOENT);
2238
2239        iter->mrt = mrt;
2240
2241        read_lock(&mrt_lock);
2242        return *pos ? ipmr_vif_seq_idx(net, seq->private, *pos - 1)
2243                : SEQ_START_TOKEN;
2244}
2245
2246static void *ipmr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2247{
2248        struct ipmr_vif_iter *iter = seq->private;
2249        struct net *net = seq_file_net(seq);
2250        struct mr_table *mrt = iter->mrt;
2251
2252        ++*pos;
2253        if (v == SEQ_START_TOKEN)
2254                return ipmr_vif_seq_idx(net, iter, 0);
2255
2256        while (++iter->ct < mrt->maxvif) {
2257                if (!VIF_EXISTS(mrt, iter->ct))
2258                        continue;
2259                return &mrt->vif_table[iter->ct];
2260        }
2261        return NULL;
2262}
2263
2264static void ipmr_vif_seq_stop(struct seq_file *seq, void *v)
2265        __releases(mrt_lock)
2266{
2267        read_unlock(&mrt_lock);
2268}
2269
2270static int ipmr_vif_seq_show(struct seq_file *seq, void *v)
2271{
2272        struct ipmr_vif_iter *iter = seq->private;
2273        struct mr_table *mrt = iter->mrt;
2274
2275        if (v == SEQ_START_TOKEN) {
2276                seq_puts(seq,
2277                         "Interface      BytesIn  PktsIn  BytesOut PktsOut Flags Local    Remote\n");
2278        } else {
2279                const struct vif_device *vif = v;
2280                const char *name =  vif->dev ? vif->dev->name : "none";
2281
2282                seq_printf(seq,
2283                           "%2Zd %-10s %8ld %7ld  %8ld %7ld %05X %08X %08X\n",
2284                           vif - mrt->vif_table,
2285                           name, vif->bytes_in, vif->pkt_in,
2286                           vif->bytes_out, vif->pkt_out,
2287                           vif->flags, vif->local, vif->remote);
2288        }
2289        return 0;
2290}
2291
2292static const struct seq_operations ipmr_vif_seq_ops = {
2293        .start = ipmr_vif_seq_start,
2294        .next  = ipmr_vif_seq_next,
2295        .stop  = ipmr_vif_seq_stop,
2296        .show  = ipmr_vif_seq_show,
2297};
2298
2299static int ipmr_vif_open(struct inode *inode, struct file *file)
2300{
2301        return seq_open_net(inode, file, &ipmr_vif_seq_ops,
2302                            sizeof(struct ipmr_vif_iter));
2303}
2304
2305static const struct file_operations ipmr_vif_fops = {
2306        .owner   = THIS_MODULE,
2307        .open    = ipmr_vif_open,
2308        .read    = seq_read,
2309        .llseek  = seq_lseek,
2310        .release = seq_release_net,
2311};
2312
2313struct ipmr_mfc_iter {
2314        struct seq_net_private p;
2315        struct mr_table *mrt;
2316        struct list_head *cache;
2317        int ct;
2318};
2319
2320
2321static struct mfc_cache *ipmr_mfc_seq_idx(struct net *net,
2322                                          struct ipmr_mfc_iter *it, loff_t pos)
2323{
2324        struct mr_table *mrt = it->mrt;
2325        struct mfc_cache *mfc;
2326
2327        rcu_read_lock();
2328        for (it->ct = 0; it->ct < MFC_LINES; it->ct++) {
2329                it->cache = &mrt->mfc_cache_array[it->ct];
2330                list_for_each_entry_rcu(mfc, it->cache, list)
2331                        if (pos-- == 0)
2332                                return mfc;
2333        }
2334        rcu_read_unlock();
2335
2336        spin_lock_bh(&mfc_unres_lock);
2337        it->cache = &mrt->mfc_unres_queue;
2338        list_for_each_entry(mfc, it->cache, list)
2339                if (pos-- == 0)
2340                        return mfc;
2341        spin_unlock_bh(&mfc_unres_lock);
2342
2343        it->cache = NULL;
2344        return NULL;
2345}
2346
2347
2348static void *ipmr_mfc_seq_start(struct seq_file *seq, loff_t *pos)
2349{
2350        struct ipmr_mfc_iter *it = seq->private;
2351        struct net *net = seq_file_net(seq);
2352        struct mr_table *mrt;
2353
2354        mrt = ipmr_get_table(net, RT_TABLE_DEFAULT);
2355        if (mrt == NULL)
2356                return ERR_PTR(-ENOENT);
2357
2358        it->mrt = mrt;
2359        it->cache = NULL;
2360        it->ct = 0;
2361        return *pos ? ipmr_mfc_seq_idx(net, seq->private, *pos - 1)
2362                : SEQ_START_TOKEN;
2363}
2364
2365static void *ipmr_mfc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2366{
2367        struct mfc_cache *mfc = v;
2368        struct ipmr_mfc_iter *it = seq->private;
2369        struct net *net = seq_file_net(seq);
2370        struct mr_table *mrt = it->mrt;
2371
2372        ++*pos;
2373
2374        if (v == SEQ_START_TOKEN)
2375                return ipmr_mfc_seq_idx(net, seq->private, 0);
2376
2377        if (mfc->list.next != it->cache)
2378                return list_entry(mfc->list.next, struct mfc_cache, list);
2379
2380        if (it->cache == &mrt->mfc_unres_queue)
2381                goto end_of_list;
2382
2383        BUG_ON(it->cache != &mrt->mfc_cache_array[it->ct]);
2384
2385        while (++it->ct < MFC_LINES) {
2386                it->cache = &mrt->mfc_cache_array[it->ct];
2387                if (list_empty(it->cache))
2388                        continue;
2389                return list_first_entry(it->cache, struct mfc_cache, list);
2390        }
2391
2392        /* exhausted cache_array, show unresolved */
2393        rcu_read_unlock();
2394        it->cache = &mrt->mfc_unres_queue;
2395        it->ct = 0;
2396
2397        spin_lock_bh(&mfc_unres_lock);
2398        if (!list_empty(it->cache))
2399                return list_first_entry(it->cache, struct mfc_cache, list);
2400
2401end_of_list:
2402        spin_unlock_bh(&mfc_unres_lock);
2403        it->cache = NULL;
2404
2405        return NULL;
2406}
2407
2408static void ipmr_mfc_seq_stop(struct seq_file *seq, void *v)
2409{
2410        struct ipmr_mfc_iter *it = seq->private;
2411        struct mr_table *mrt = it->mrt;
2412
2413        if (it->cache == &mrt->mfc_unres_queue)
2414                spin_unlock_bh(&mfc_unres_lock);
2415        else if (it->cache == &mrt->mfc_cache_array[it->ct])
2416                rcu_read_unlock();
2417}
2418
2419static int ipmr_mfc_seq_show(struct seq_file *seq, void *v)
2420{
2421        int n;
2422
2423        if (v == SEQ_START_TOKEN) {
2424                seq_puts(seq,
2425                 "Group    Origin   Iif     Pkts    Bytes    Wrong Oifs\n");
2426        } else {
2427                const struct mfc_cache *mfc = v;
2428                const struct ipmr_mfc_iter *it = seq->private;
2429                const struct mr_table *mrt = it->mrt;
2430
2431                seq_printf(seq, "%08X %08X %-3hd",
2432                           (__force u32) mfc->mfc_mcastgrp,
2433                           (__force u32) mfc->mfc_origin,
2434                           mfc->mfc_parent);
2435
2436                if (it->cache != &mrt->mfc_unres_queue) {
2437                        seq_printf(seq, " %8lu %8lu %8lu",
2438                                   mfc->mfc_un.res.pkt,
2439                                   mfc->mfc_un.res.bytes,
2440                                   mfc->mfc_un.res.wrong_if);
2441                        for (n = mfc->mfc_un.res.minvif;
2442                             n < mfc->mfc_un.res.maxvif; n++) {
2443                                if (VIF_EXISTS(mrt, n) &&
2444                                    mfc->mfc_un.res.ttls[n] < 255)
2445                                        seq_printf(seq,
2446                                           " %2d:%-3d",
2447                                           n, mfc->mfc_un.res.ttls[n]);
2448                        }
2449                } else {
2450                        /* unresolved mfc_caches don't contain
2451                         * pkt, bytes and wrong_if values
2452                         */
2453                        seq_printf(seq, " %8lu %8lu %8lu", 0ul, 0ul, 0ul);
2454                }
2455                seq_putc(seq, '\n');
2456        }
2457        return 0;
2458}
2459
2460static const struct seq_operations ipmr_mfc_seq_ops = {
2461        .start = ipmr_mfc_seq_start,
2462        .next  = ipmr_mfc_seq_next,
2463        .stop  = ipmr_mfc_seq_stop,
2464        .show  = ipmr_mfc_seq_show,
2465};
2466
2467static int ipmr_mfc_open(struct inode *inode, struct file *file)
2468{
2469        return seq_open_net(inode, file, &ipmr_mfc_seq_ops,
2470                            sizeof(struct ipmr_mfc_iter));
2471}
2472
2473static const struct file_operations ipmr_mfc_fops = {
2474        .owner   = THIS_MODULE,
2475        .open    = ipmr_mfc_open,
2476        .read    = seq_read,
2477        .llseek  = seq_lseek,
2478        .release = seq_release_net,
2479};
2480#endif
2481
2482#ifdef CONFIG_IP_PIMSM_V2
2483static const struct net_protocol pim_protocol = {
2484        .handler        =       pim_rcv,
2485        .netns_ok       =       1,
2486};
2487#endif
2488
2489
2490/*
2491 *      Setup for IP multicast routing
2492 */
2493static int __net_init ipmr_net_init(struct net *net)
2494{
2495        int err;
2496
2497        err = ipmr_rules_init(net);
2498        if (err < 0)
2499                goto fail;
2500
2501#ifdef CONFIG_PROC_FS
2502        err = -ENOMEM;
2503        if (!proc_net_fops_create(net, "ip_mr_vif", 0, &ipmr_vif_fops))
2504                goto proc_vif_fail;
2505        if (!proc_net_fops_create(net, "ip_mr_cache", 0, &ipmr_mfc_fops))
2506                goto proc_cache_fail;
2507#endif
2508        return 0;
2509
2510#ifdef CONFIG_PROC_FS
2511proc_cache_fail:
2512        proc_net_remove(net, "ip_mr_vif");
2513proc_vif_fail:
2514        ipmr_rules_exit(net);
2515#endif
2516fail:
2517        return err;
2518}
2519
2520static void __net_exit ipmr_net_exit(struct net *net)
2521{
2522#ifdef CONFIG_PROC_FS
2523        proc_net_remove(net, "ip_mr_cache");
2524        proc_net_remove(net, "ip_mr_vif");
2525#endif
2526        ipmr_rules_exit(net);
2527}
2528
2529static struct pernet_operations ipmr_net_ops = {
2530        .init = ipmr_net_init,
2531        .exit = ipmr_net_exit,
2532};
2533
2534int __init ip_mr_init(void)
2535{
2536        int err;
2537
2538        mrt_cachep = kmem_cache_create("ip_mrt_cache",
2539                                       sizeof(struct mfc_cache),
2540                                       0, SLAB_HWCACHE_ALIGN | SLAB_PANIC,
2541                                       NULL);
2542        if (!mrt_cachep)
2543                return -ENOMEM;
2544
2545        err = register_pernet_subsys(&ipmr_net_ops);
2546        if (err)
2547                goto reg_pernet_fail;
2548
2549        err = register_netdevice_notifier(&ip_mr_notifier);
2550        if (err)
2551                goto reg_notif_fail;
2552#ifdef CONFIG_IP_PIMSM_V2
2553        if (inet_add_protocol(&pim_protocol, IPPROTO_PIM) < 0) {
2554                pr_err("%s: can't add PIM protocol\n", __func__);
2555                err = -EAGAIN;
2556                goto add_proto_fail;
2557        }
2558#endif
2559        rtnl_register(RTNL_FAMILY_IPMR, RTM_GETROUTE,
2560                      NULL, ipmr_rtm_dumproute, NULL);
2561        return 0;
2562
2563#ifdef CONFIG_IP_PIMSM_V2
2564add_proto_fail:
2565        unregister_netdevice_notifier(&ip_mr_notifier);
2566#endif
2567reg_notif_fail:
2568        unregister_pernet_subsys(&ipmr_net_ops);
2569reg_pernet_fail:
2570        kmem_cache_destroy(mrt_cachep);
2571        return err;
2572}
2573
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