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mcast.c

/*
 *    Multicast support for IPv6
 *    Linux INET6 implementation
 *
 *    Authors:
 *    Pedro Roque       <roque@di.fc.ul.pt>
 *
 *    $Id: mcast.c,v 1.40 2002/02/08 03:57:19 davem Exp $
 *
 *    Based on linux/ipv4/igmp.c and linux/ipv4/ip_sockglue.c
 *
 *    This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

/* Changes:
 *
 *    yoshfuji    : fix format of router-alert option
 *    YOSHIFUJI Hideaki @USAGI:
 *          Fixed source address for MLD message based on
 *          <draft-ietf-magma-mld-source-05.txt>.
 *    YOSHIFUJI Hideaki @USAGI:
 *          - Ignore Queries for invalid addresses.
 *          - MLD for link-local addresses.
 *    David L Stevens <dlstevens@us.ibm.com>:
 *          - MLDv2 support
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/jiffies.h>
#include <linux/times.h>
#include <linux/net.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/route.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>

#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>

#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/snmp.h>

#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/if_inet6.h>
#include <net/ndisc.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>

#include <net/ip6_checksum.h>

/* Set to 3 to get tracing... */
#define MCAST_DEBUG 2

#if MCAST_DEBUG >= 3
#define MDBG(x) printk x
#else
#define MDBG(x)
#endif

/*
 *  These header formats should be in a separate include file, but icmpv6.h
 *  doesn't have in6_addr defined in all cases, there is no __u128, and no
 *  other files reference these.
 *
 *                +-DLS 4/14/03
 */

/* Multicast Listener Discovery version 2 headers */

struct mld2_grec {
      __u8        grec_type;
      __u8        grec_auxwords;
      __be16            grec_nsrcs;
      struct in6_addr   grec_mca;
      struct in6_addr   grec_src[0];
};

struct mld2_report {
      __u8  type;
      __u8  resv1;
      __sum16     csum;
      __be16      resv2;
      __be16      ngrec;
      struct mld2_grec grec[0];
};

struct mld2_query {
      __u8 type;
      __u8 code;
      __sum16 csum;
      __be16 mrc;
      __be16 resv1;
      struct in6_addr mca;
#if defined(__LITTLE_ENDIAN_BITFIELD)
      __u8 qrv:3,
           suppress:1,
           resv2:4;
#elif defined(__BIG_ENDIAN_BITFIELD)
      __u8 resv2:4,
           suppress:1,
           qrv:3;
#else
#error "Please fix <asm/byteorder.h>"
#endif
      __u8 qqic;
      __be16 nsrcs;
      struct in6_addr srcs[0];
};

static struct in6_addr mld2_all_mcr = MLD2_ALL_MCR_INIT;

/* Big mc list lock for all the sockets */
static DEFINE_RWLOCK(ipv6_sk_mc_lock);

static struct socket *igmp6_socket;

int __ipv6_dev_mc_dec(struct inet6_dev *idev, struct in6_addr *addr);

static void igmp6_join_group(struct ifmcaddr6 *ma);
static void igmp6_leave_group(struct ifmcaddr6 *ma);
static void igmp6_timer_handler(unsigned long data);

static void mld_gq_timer_expire(unsigned long data);
static void mld_ifc_timer_expire(unsigned long data);
static void mld_ifc_event(struct inet6_dev *idev);
static void mld_add_delrec(struct inet6_dev *idev, struct ifmcaddr6 *pmc);
static void mld_del_delrec(struct inet6_dev *idev, struct in6_addr *addr);
static void mld_clear_delrec(struct inet6_dev *idev);
static int sf_setstate(struct ifmcaddr6 *pmc);
static void sf_markstate(struct ifmcaddr6 *pmc);
static void ip6_mc_clear_src(struct ifmcaddr6 *pmc);
static int ip6_mc_del_src(struct inet6_dev *idev, struct in6_addr *pmca,
                    int sfmode, int sfcount, struct in6_addr *psfsrc,
                    int delta);
static int ip6_mc_add_src(struct inet6_dev *idev, struct in6_addr *pmca,
                    int sfmode, int sfcount, struct in6_addr *psfsrc,
                    int delta);
static int ip6_mc_leave_src(struct sock *sk, struct ipv6_mc_socklist *iml,
                      struct inet6_dev *idev);


#define IGMP6_UNSOLICITED_IVAL      (10*HZ)
#define MLD_QRV_DEFAULT       2

#define MLD_V1_SEEN(idev) (ipv6_devconf.force_mld_version == 1 || \
            (idev)->cnf.force_mld_version == 1 || \
            ((idev)->mc_v1_seen && \
            time_before(jiffies, (idev)->mc_v1_seen)))

#define MLDV2_MASK(value, nb) ((nb)>=32 ? (value) : ((1<<(nb))-1) & (value))
#define MLDV2_EXP(thresh, nbmant, nbexp, value) \
      ((value) < (thresh) ? (value) : \
      ((MLDV2_MASK(value, nbmant) | (1<<(nbmant))) << \
      (MLDV2_MASK((value) >> (nbmant), nbexp) + (nbexp))))

#define MLDV2_QQIC(value) MLDV2_EXP(0x80, 4, 3, value)
#define MLDV2_MRC(value) MLDV2_EXP(0x8000, 12, 3, value)

#define IPV6_MLD_MAX_MSF      64

int sysctl_mld_max_msf __read_mostly = IPV6_MLD_MAX_MSF;

/*
 *    socket join on multicast group
 */

int ipv6_sock_mc_join(struct sock *sk, int ifindex, struct in6_addr *addr)
{
      struct net_device *dev = NULL;
      struct ipv6_mc_socklist *mc_lst;
      struct ipv6_pinfo *np = inet6_sk(sk);
      int err;

      if (!ipv6_addr_is_multicast(addr))
            return -EINVAL;

      read_lock_bh(&ipv6_sk_mc_lock);
      for (mc_lst=np->ipv6_mc_list; mc_lst; mc_lst=mc_lst->next) {
            if ((ifindex == 0 || mc_lst->ifindex == ifindex) &&
                ipv6_addr_equal(&mc_lst->addr, addr)) {
                  read_unlock_bh(&ipv6_sk_mc_lock);
                  return -EADDRINUSE;
            }
      }
      read_unlock_bh(&ipv6_sk_mc_lock);

      mc_lst = sock_kmalloc(sk, sizeof(struct ipv6_mc_socklist), GFP_KERNEL);

      if (mc_lst == NULL)
            return -ENOMEM;

      mc_lst->next = NULL;
      ipv6_addr_copy(&mc_lst->addr, addr);

      if (ifindex == 0) {
            struct rt6_info *rt;
            rt = rt6_lookup(addr, NULL, 0, 0);
            if (rt) {
                  dev = rt->rt6i_dev;
                  dev_hold(dev);
                  dst_release(&rt->u.dst);
            }
      } else
            dev = dev_get_by_index(&init_net, ifindex);

      if (dev == NULL) {
            sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
            return -ENODEV;
      }

      mc_lst->ifindex = dev->ifindex;
      mc_lst->sfmode = MCAST_EXCLUDE;
      rwlock_init(&mc_lst->sflock);
      mc_lst->sflist = NULL;

      /*
       *    now add/increase the group membership on the device
       */

      err = ipv6_dev_mc_inc(dev, addr);

      if (err) {
            sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
            dev_put(dev);
            return err;
      }

      write_lock_bh(&ipv6_sk_mc_lock);
      mc_lst->next = np->ipv6_mc_list;
      np->ipv6_mc_list = mc_lst;
      write_unlock_bh(&ipv6_sk_mc_lock);

      dev_put(dev);

      return 0;
}

/*
 *    socket leave on multicast group
 */
int ipv6_sock_mc_drop(struct sock *sk, int ifindex, struct in6_addr *addr)
{
      struct ipv6_pinfo *np = inet6_sk(sk);
      struct ipv6_mc_socklist *mc_lst, **lnk;

      write_lock_bh(&ipv6_sk_mc_lock);
      for (lnk = &np->ipv6_mc_list; (mc_lst = *lnk) !=NULL ; lnk = &mc_lst->next) {
            if ((ifindex == 0 || mc_lst->ifindex == ifindex) &&
                ipv6_addr_equal(&mc_lst->addr, addr)) {
                  struct net_device *dev;

                  *lnk = mc_lst->next;
                  write_unlock_bh(&ipv6_sk_mc_lock);

                  if ((dev = dev_get_by_index(&init_net, mc_lst->ifindex)) != NULL) {
                        struct inet6_dev *idev = in6_dev_get(dev);

                        (void) ip6_mc_leave_src(sk, mc_lst, idev);
                        if (idev) {
                              __ipv6_dev_mc_dec(idev, &mc_lst->addr);
                              in6_dev_put(idev);
                        }
                        dev_put(dev);
                  } else
                        (void) ip6_mc_leave_src(sk, mc_lst, NULL);
                  sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
                  return 0;
            }
      }
      write_unlock_bh(&ipv6_sk_mc_lock);

      return -EADDRNOTAVAIL;
}

static struct inet6_dev *ip6_mc_find_dev(struct in6_addr *group, int ifindex)
{
      struct net_device *dev = NULL;
      struct inet6_dev *idev = NULL;

      if (ifindex == 0) {
            struct rt6_info *rt;

            rt = rt6_lookup(group, NULL, 0, 0);
            if (rt) {
                  dev = rt->rt6i_dev;
                  dev_hold(dev);
                  dst_release(&rt->u.dst);
            }
      } else
            dev = dev_get_by_index(&init_net, ifindex);

      if (!dev)
            return NULL;
      idev = in6_dev_get(dev);
      if (!idev) {
            dev_put(dev);
            return NULL;
      }
      read_lock_bh(&idev->lock);
      if (idev->dead) {
            read_unlock_bh(&idev->lock);
            in6_dev_put(idev);
            dev_put(dev);
            return NULL;
      }
      return idev;
}

void ipv6_sock_mc_close(struct sock *sk)
{
      struct ipv6_pinfo *np = inet6_sk(sk);
      struct ipv6_mc_socklist *mc_lst;

      write_lock_bh(&ipv6_sk_mc_lock);
      while ((mc_lst = np->ipv6_mc_list) != NULL) {
            struct net_device *dev;

            np->ipv6_mc_list = mc_lst->next;
            write_unlock_bh(&ipv6_sk_mc_lock);

            dev = dev_get_by_index(&init_net, mc_lst->ifindex);
            if (dev) {
                  struct inet6_dev *idev = in6_dev_get(dev);

                  (void) ip6_mc_leave_src(sk, mc_lst, idev);
                  if (idev) {
                        __ipv6_dev_mc_dec(idev, &mc_lst->addr);
                        in6_dev_put(idev);
                  }
                  dev_put(dev);
            } else
                  (void) ip6_mc_leave_src(sk, mc_lst, NULL);

            sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));

            write_lock_bh(&ipv6_sk_mc_lock);
      }
      write_unlock_bh(&ipv6_sk_mc_lock);
}

int ip6_mc_source(int add, int omode, struct sock *sk,
      struct group_source_req *pgsr)
{
      struct in6_addr *source, *group;
      struct ipv6_mc_socklist *pmc;
      struct net_device *dev;
      struct inet6_dev *idev;
      struct ipv6_pinfo *inet6 = inet6_sk(sk);
      struct ip6_sf_socklist *psl;
      int i, j, rv;
      int leavegroup = 0;
      int pmclocked = 0;
      int err;

      if (pgsr->gsr_group.ss_family != AF_INET6 ||
          pgsr->gsr_source.ss_family != AF_INET6)
            return -EINVAL;

      source = &((struct sockaddr_in6 *)&pgsr->gsr_source)->sin6_addr;
      group = &((struct sockaddr_in6 *)&pgsr->gsr_group)->sin6_addr;

      if (!ipv6_addr_is_multicast(group))
            return -EINVAL;

      idev = ip6_mc_find_dev(group, pgsr->gsr_interface);
      if (!idev)
            return -ENODEV;
      dev = idev->dev;

      err = -EADDRNOTAVAIL;

      read_lock_bh(&ipv6_sk_mc_lock);
      for (pmc=inet6->ipv6_mc_list; pmc; pmc=pmc->next) {
            if (pgsr->gsr_interface && pmc->ifindex != pgsr->gsr_interface)
                  continue;
            if (ipv6_addr_equal(&pmc->addr, group))
                  break;
      }
      if (!pmc) {       /* must have a prior join */
            err = -EINVAL;
            goto done;
      }
      /* if a source filter was set, must be the same mode as before */
      if (pmc->sflist) {
            if (pmc->sfmode != omode) {
                  err = -EINVAL;
                  goto done;
            }
      } else if (pmc->sfmode != omode) {
            /* allow mode switches for empty-set filters */
            ip6_mc_add_src(idev, group, omode, 0, NULL, 0);
            ip6_mc_del_src(idev, group, pmc->sfmode, 0, NULL, 0);
            pmc->sfmode = omode;
      }

      write_lock_bh(&pmc->sflock);
      pmclocked = 1;

      psl = pmc->sflist;
      if (!add) {
            if (!psl)
                  goto done;  /* err = -EADDRNOTAVAIL */
            rv = !0;
            for (i=0; i<psl->sl_count; i++) {
                  rv = memcmp(&psl->sl_addr[i], source,
                        sizeof(struct in6_addr));
                  if (rv == 0)
                        break;
            }
            if (rv)           /* source not found */
                  goto done;  /* err = -EADDRNOTAVAIL */

            /* special case - (INCLUDE, empty) == LEAVE_GROUP */
            if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
                  leavegroup = 1;
                  goto done;
            }

            /* update the interface filter */
            ip6_mc_del_src(idev, group, omode, 1, source, 1);

            for (j=i+1; j<psl->sl_count; j++)
                  psl->sl_addr[j-1] = psl->sl_addr[j];
            psl->sl_count--;
            err = 0;
            goto done;
      }
      /* else, add a new source to the filter */

      if (psl && psl->sl_count >= sysctl_mld_max_msf) {
            err = -ENOBUFS;
            goto done;
      }
      if (!psl || psl->sl_count == psl->sl_max) {
            struct ip6_sf_socklist *newpsl;
            int count = IP6_SFBLOCK;

            if (psl)
                  count += psl->sl_max;
            newpsl = sock_kmalloc(sk, IP6_SFLSIZE(count), GFP_ATOMIC);
            if (!newpsl) {
                  err = -ENOBUFS;
                  goto done;
            }
            newpsl->sl_max = count;
            newpsl->sl_count = count - IP6_SFBLOCK;
            if (psl) {
                  for (i=0; i<psl->sl_count; i++)
                        newpsl->sl_addr[i] = psl->sl_addr[i];
                  sock_kfree_s(sk, psl, IP6_SFLSIZE(psl->sl_max));
            }
            pmc->sflist = psl = newpsl;
      }
      rv = 1;     /* > 0 for insert logic below if sl_count is 0 */
      for (i=0; i<psl->sl_count; i++) {
            rv = memcmp(&psl->sl_addr[i], source, sizeof(struct in6_addr));
            if (rv == 0)
                  break;
      }
      if (rv == 0)            /* address already there is an error */
            goto done;
      for (j=psl->sl_count-1; j>=i; j--)
            psl->sl_addr[j+1] = psl->sl_addr[j];
      psl->sl_addr[i] = *source;
      psl->sl_count++;
      err = 0;
      /* update the interface list */
      ip6_mc_add_src(idev, group, omode, 1, source, 1);
done:
      if (pmclocked)
            write_unlock_bh(&pmc->sflock);
      read_unlock_bh(&ipv6_sk_mc_lock);
      read_unlock_bh(&idev->lock);
      in6_dev_put(idev);
      dev_put(dev);
      if (leavegroup)
            return ipv6_sock_mc_drop(sk, pgsr->gsr_interface, group);
      return err;
}

int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf)
{
      struct in6_addr *group;
      struct ipv6_mc_socklist *pmc;
      struct net_device *dev;
      struct inet6_dev *idev;
      struct ipv6_pinfo *inet6 = inet6_sk(sk);
      struct ip6_sf_socklist *newpsl, *psl;
      int leavegroup = 0;
      int i, err;

      group = &((struct sockaddr_in6 *)&gsf->gf_group)->sin6_addr;

      if (!ipv6_addr_is_multicast(group))
            return -EINVAL;
      if (gsf->gf_fmode != MCAST_INCLUDE &&
          gsf->gf_fmode != MCAST_EXCLUDE)
            return -EINVAL;

      idev = ip6_mc_find_dev(group, gsf->gf_interface);

      if (!idev)
            return -ENODEV;
      dev = idev->dev;

      err = 0;
      read_lock_bh(&ipv6_sk_mc_lock);

      if (gsf->gf_fmode == MCAST_INCLUDE && gsf->gf_numsrc == 0) {
            leavegroup = 1;
            goto done;
      }

      for (pmc=inet6->ipv6_mc_list; pmc; pmc=pmc->next) {
            if (pmc->ifindex != gsf->gf_interface)
                  continue;
            if (ipv6_addr_equal(&pmc->addr, group))
                  break;
      }
      if (!pmc) {       /* must have a prior join */
            err = -EINVAL;
            goto done;
      }
      if (gsf->gf_numsrc) {
            newpsl = sock_kmalloc(sk, IP6_SFLSIZE(gsf->gf_numsrc),
                                            GFP_ATOMIC);
            if (!newpsl) {
                  err = -ENOBUFS;
                  goto done;
            }
            newpsl->sl_max = newpsl->sl_count = gsf->gf_numsrc;
            for (i=0; i<newpsl->sl_count; ++i) {
                  struct sockaddr_in6 *psin6;

                  psin6 = (struct sockaddr_in6 *)&gsf->gf_slist[i];
                  newpsl->sl_addr[i] = psin6->sin6_addr;
            }
            err = ip6_mc_add_src(idev, group, gsf->gf_fmode,
                  newpsl->sl_count, newpsl->sl_addr, 0);
            if (err) {
                  sock_kfree_s(sk, newpsl, IP6_SFLSIZE(newpsl->sl_max));
                  goto done;
            }
      } else {
            newpsl = NULL;
            (void) ip6_mc_add_src(idev, group, gsf->gf_fmode, 0, NULL, 0);
      }

      write_lock_bh(&pmc->sflock);
      psl = pmc->sflist;
      if (psl) {
            (void) ip6_mc_del_src(idev, group, pmc->sfmode,
                  psl->sl_count, psl->sl_addr, 0);
            sock_kfree_s(sk, psl, IP6_SFLSIZE(psl->sl_max));
      } else
            (void) ip6_mc_del_src(idev, group, pmc->sfmode, 0, NULL, 0);
      pmc->sflist = newpsl;
      pmc->sfmode = gsf->gf_fmode;
      write_unlock_bh(&pmc->sflock);
      err = 0;
done:
      read_unlock_bh(&ipv6_sk_mc_lock);
      read_unlock_bh(&idev->lock);
      in6_dev_put(idev);
      dev_put(dev);
      if (leavegroup)
            err = ipv6_sock_mc_drop(sk, gsf->gf_interface, group);
      return err;
}

int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
      struct group_filter __user *optval, int __user *optlen)
{
      int err, i, count, copycount;
      struct in6_addr *group;
      struct ipv6_mc_socklist *pmc;
      struct inet6_dev *idev;
      struct net_device *dev;
      struct ipv6_pinfo *inet6 = inet6_sk(sk);
      struct ip6_sf_socklist *psl;

      group = &((struct sockaddr_in6 *)&gsf->gf_group)->sin6_addr;

      if (!ipv6_addr_is_multicast(group))
            return -EINVAL;

      idev = ip6_mc_find_dev(group, gsf->gf_interface);

      if (!idev)
            return -ENODEV;

      dev = idev->dev;

      err = -EADDRNOTAVAIL;
      /*
       * changes to the ipv6_mc_list require the socket lock and
       * a read lock on ip6_sk_mc_lock. We have the socket lock,
       * so reading the list is safe.
       */

      for (pmc=inet6->ipv6_mc_list; pmc; pmc=pmc->next) {
            if (pmc->ifindex != gsf->gf_interface)
                  continue;
            if (ipv6_addr_equal(group, &pmc->addr))
                  break;
      }
      if (!pmc)         /* must have a prior join */
            goto done;
      gsf->gf_fmode = pmc->sfmode;
      psl = pmc->sflist;
      count = psl ? psl->sl_count : 0;
      read_unlock_bh(&idev->lock);
      in6_dev_put(idev);
      dev_put(dev);

      copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
      gsf->gf_numsrc = count;
      if (put_user(GROUP_FILTER_SIZE(copycount), optlen) ||
          copy_to_user(optval, gsf, GROUP_FILTER_SIZE(0))) {
            return -EFAULT;
      }
      /* changes to psl require the socket lock, a read lock on
       * on ipv6_sk_mc_lock and a write lock on pmc->sflock. We
       * have the socket lock, so reading here is safe.
       */
      for (i=0; i<copycount; i++) {
            struct sockaddr_in6 *psin6;
            struct sockaddr_storage ss;

            psin6 = (struct sockaddr_in6 *)&ss;
            memset(&ss, 0, sizeof(ss));
            psin6->sin6_family = AF_INET6;
            psin6->sin6_addr = psl->sl_addr[i];
            if (copy_to_user(&optval->gf_slist[i], &ss, sizeof(ss)))
                  return -EFAULT;
      }
      return 0;
done:
      read_unlock_bh(&idev->lock);
      in6_dev_put(idev);
      dev_put(dev);
      return err;
}

int inet6_mc_check(struct sock *sk, struct in6_addr *mc_addr,
      struct in6_addr *src_addr)
{
      struct ipv6_pinfo *np = inet6_sk(sk);
      struct ipv6_mc_socklist *mc;
      struct ip6_sf_socklist *psl;
      int rv = 1;

      read_lock(&ipv6_sk_mc_lock);
      for (mc = np->ipv6_mc_list; mc; mc = mc->next) {
            if (ipv6_addr_equal(&mc->addr, mc_addr))
                  break;
      }
      if (!mc) {
            read_unlock(&ipv6_sk_mc_lock);
            return 1;
      }
      read_lock(&mc->sflock);
      psl = mc->sflist;
      if (!psl) {
            rv = mc->sfmode == MCAST_EXCLUDE;
      } else {
            int i;

            for (i=0; i<psl->sl_count; i++) {
                  if (ipv6_addr_equal(&psl->sl_addr[i], src_addr))
                        break;
            }
            if (mc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
                  rv = 0;
            if (mc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
                  rv = 0;
      }
      read_unlock(&mc->sflock);
      read_unlock(&ipv6_sk_mc_lock);

      return rv;
}

static void ma_put(struct ifmcaddr6 *mc)
{
      if (atomic_dec_and_test(&mc->mca_refcnt)) {
            in6_dev_put(mc->idev);
            kfree(mc);
      }
}

static void igmp6_group_added(struct ifmcaddr6 *mc)
{
      struct net_device *dev = mc->idev->dev;
      char buf[MAX_ADDR_LEN];

      spin_lock_bh(&mc->mca_lock);
      if (!(mc->mca_flags&MAF_LOADED)) {
            mc->mca_flags |= MAF_LOADED;
            if (ndisc_mc_map(&mc->mca_addr, buf, dev, 0) == 0)
                  dev_mc_add(dev, buf, dev->addr_len, 0);
      }
      spin_unlock_bh(&mc->mca_lock);

      if (!(dev->flags & IFF_UP) || (mc->mca_flags & MAF_NOREPORT))
            return;

      if (MLD_V1_SEEN(mc->idev)) {
            igmp6_join_group(mc);
            return;
      }
      /* else v2 */

      mc->mca_crcount = mc->idev->mc_qrv;
      mld_ifc_event(mc->idev);
}

static void igmp6_group_dropped(struct ifmcaddr6 *mc)
{
      struct net_device *dev = mc->idev->dev;
      char buf[MAX_ADDR_LEN];

      spin_lock_bh(&mc->mca_lock);
      if (mc->mca_flags&MAF_LOADED) {
            mc->mca_flags &= ~MAF_LOADED;
            if (ndisc_mc_map(&mc->mca_addr, buf, dev, 0) == 0)
                  dev_mc_delete(dev, buf, dev->addr_len, 0);
      }

      if (mc->mca_flags & MAF_NOREPORT)
            goto done;
      spin_unlock_bh(&mc->mca_lock);

      if (!mc->idev->dead)
            igmp6_leave_group(mc);

      spin_lock_bh(&mc->mca_lock);
      if (del_timer(&mc->mca_timer))
            atomic_dec(&mc->mca_refcnt);
done:
      ip6_mc_clear_src(mc);
      spin_unlock_bh(&mc->mca_lock);
}

/*
 * deleted ifmcaddr6 manipulation
 */
static void mld_add_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
{
      struct ifmcaddr6 *pmc;

      /* this is an "ifmcaddr6" for convenience; only the fields below
       * are actually used. In particular, the refcnt and users are not
       * used for management of the delete list. Using the same structure
       * for deleted items allows change reports to use common code with
       * non-deleted or query-response MCA's.
       */
      pmc = kzalloc(sizeof(*pmc), GFP_ATOMIC);
      if (!pmc)
            return;

      spin_lock_bh(&im->mca_lock);
      spin_lock_init(&pmc->mca_lock);
      pmc->idev = im->idev;
      in6_dev_hold(idev);
      pmc->mca_addr = im->mca_addr;
      pmc->mca_crcount = idev->mc_qrv;
      pmc->mca_sfmode = im->mca_sfmode;
      if (pmc->mca_sfmode == MCAST_INCLUDE) {
            struct ip6_sf_list *psf;

            pmc->mca_tomb = im->mca_tomb;
            pmc->mca_sources = im->mca_sources;
            im->mca_tomb = im->mca_sources = NULL;
            for (psf=pmc->mca_sources; psf; psf=psf->sf_next)
                  psf->sf_crcount = pmc->mca_crcount;
      }
      spin_unlock_bh(&im->mca_lock);

      write_lock_bh(&idev->mc_lock);
      pmc->next = idev->mc_tomb;
      idev->mc_tomb = pmc;
      write_unlock_bh(&idev->mc_lock);
}

static void mld_del_delrec(struct inet6_dev *idev, struct in6_addr *pmca)
{
      struct ifmcaddr6 *pmc, *pmc_prev;
      struct ip6_sf_list *psf, *psf_next;

      write_lock_bh(&idev->mc_lock);
      pmc_prev = NULL;
      for (pmc=idev->mc_tomb; pmc; pmc=pmc->next) {
            if (ipv6_addr_equal(&pmc->mca_addr, pmca))
                  break;
            pmc_prev = pmc;
      }
      if (pmc) {
            if (pmc_prev)
                  pmc_prev->next = pmc->next;
            else
                  idev->mc_tomb = pmc->next;
      }
      write_unlock_bh(&idev->mc_lock);
      if (pmc) {
            for (psf=pmc->mca_tomb; psf; psf=psf_next) {
                  psf_next = psf->sf_next;
                  kfree(psf);
            }
            in6_dev_put(pmc->idev);
            kfree(pmc);
      }
}

static void mld_clear_delrec(struct inet6_dev *idev)
{
      struct ifmcaddr6 *pmc, *nextpmc;

      write_lock_bh(&idev->mc_lock);
      pmc = idev->mc_tomb;
      idev->mc_tomb = NULL;
      write_unlock_bh(&idev->mc_lock);

      for (; pmc; pmc = nextpmc) {
            nextpmc = pmc->next;
            ip6_mc_clear_src(pmc);
            in6_dev_put(pmc->idev);
            kfree(pmc);
      }

      /* clear dead sources, too */
      read_lock_bh(&idev->lock);
      for (pmc=idev->mc_list; pmc; pmc=pmc->next) {
            struct ip6_sf_list *psf, *psf_next;

            spin_lock_bh(&pmc->mca_lock);
            psf = pmc->mca_tomb;
            pmc->mca_tomb = NULL;
            spin_unlock_bh(&pmc->mca_lock);
            for (; psf; psf=psf_next) {
                  psf_next = psf->sf_next;
                  kfree(psf);
            }
      }
      read_unlock_bh(&idev->lock);
}


/*
 *    device multicast group inc (add if not found)
 */
int ipv6_dev_mc_inc(struct net_device *dev, struct in6_addr *addr)
{
      struct ifmcaddr6 *mc;
      struct inet6_dev *idev;

      idev = in6_dev_get(dev);

      if (idev == NULL)
            return -EINVAL;

      write_lock_bh(&idev->lock);
      if (idev->dead) {
            write_unlock_bh(&idev->lock);
            in6_dev_put(idev);
            return -ENODEV;
      }

      for (mc = idev->mc_list; mc; mc = mc->next) {
            if (ipv6_addr_equal(&mc->mca_addr, addr)) {
                  mc->mca_users++;
                  write_unlock_bh(&idev->lock);
                  ip6_mc_add_src(idev, &mc->mca_addr, MCAST_EXCLUDE, 0,
                        NULL, 0);
                  in6_dev_put(idev);
                  return 0;
            }
      }

      /*
       *    not found: create a new one.
       */

      mc = kzalloc(sizeof(struct ifmcaddr6), GFP_ATOMIC);

      if (mc == NULL) {
            write_unlock_bh(&idev->lock);
            in6_dev_put(idev);
            return -ENOMEM;
      }

      init_timer(&mc->mca_timer);
      mc->mca_timer.function = igmp6_timer_handler;
      mc->mca_timer.data = (unsigned long) mc;

      ipv6_addr_copy(&mc->mca_addr, addr);
      mc->idev = idev;
      mc->mca_users = 1;
      /* mca_stamp should be updated upon changes */
      mc->mca_cstamp = mc->mca_tstamp = jiffies;
      atomic_set(&mc->mca_refcnt, 2);
      spin_lock_init(&mc->mca_lock);

      /* initial mode is (EX, empty) */
      mc->mca_sfmode = MCAST_EXCLUDE;
      mc->mca_sfcount[MCAST_EXCLUDE] = 1;

      if (ipv6_addr_is_ll_all_nodes(&mc->mca_addr) ||
          IPV6_ADDR_MC_SCOPE(&mc->mca_addr) < IPV6_ADDR_SCOPE_LINKLOCAL)
            mc->mca_flags |= MAF_NOREPORT;

      mc->next = idev->mc_list;
      idev->mc_list = mc;
      write_unlock_bh(&idev->lock);

      mld_del_delrec(idev, &mc->mca_addr);
      igmp6_group_added(mc);
      ma_put(mc);
      return 0;
}

/*
 *    device multicast group del
 */
int __ipv6_dev_mc_dec(struct inet6_dev *idev, struct in6_addr *addr)
{
      struct ifmcaddr6 *ma, **map;

      write_lock_bh(&idev->lock);
      for (map = &idev->mc_list; (ma=*map) != NULL; map = &ma->next) {
            if (ipv6_addr_equal(&ma->mca_addr, addr)) {
                  if (--ma->mca_users == 0) {
                        *map = ma->next;
                        write_unlock_bh(&idev->lock);

                        igmp6_group_dropped(ma);

                        ma_put(ma);
                        return 0;
                  }
                  write_unlock_bh(&idev->lock);
                  return 0;
            }
      }
      write_unlock_bh(&idev->lock);

      return -ENOENT;
}

int ipv6_dev_mc_dec(struct net_device *dev, struct in6_addr *addr)
{
      struct inet6_dev *idev = in6_dev_get(dev);
      int err;

      if (!idev)
            return -ENODEV;

      err = __ipv6_dev_mc_dec(idev, addr);

      in6_dev_put(idev);

      return err;
}

/*
 * identify MLD packets for MLD filter exceptions
 */
int ipv6_is_mld(struct sk_buff *skb, int nexthdr)
{
      struct icmp6hdr *pic;

      if (nexthdr != IPPROTO_ICMPV6)
            return 0;

      if (!pskb_may_pull(skb, sizeof(struct icmp6hdr)))
            return 0;

      pic = icmp6_hdr(skb);

      switch (pic->icmp6_type) {
      case ICMPV6_MGM_QUERY:
      case ICMPV6_MGM_REPORT:
      case ICMPV6_MGM_REDUCTION:
      case ICMPV6_MLD2_REPORT:
            return 1;
      default:
            break;
      }
      return 0;
}

/*
 *    check if the interface/address pair is valid
 */
int ipv6_chk_mcast_addr(struct net_device *dev, struct in6_addr *group,
      struct in6_addr *src_addr)
{
      struct inet6_dev *idev;
      struct ifmcaddr6 *mc;
      int rv = 0;

      idev = in6_dev_get(dev);
      if (idev) {
            read_lock_bh(&idev->lock);
            for (mc = idev->mc_list; mc; mc=mc->next) {
                  if (ipv6_addr_equal(&mc->mca_addr, group))
                        break;
            }
            if (mc) {
                  if (src_addr && !ipv6_addr_any(src_addr)) {
                        struct ip6_sf_list *psf;

                        spin_lock_bh(&mc->mca_lock);
                        for (psf=mc->mca_sources;psf;psf=psf->sf_next) {
                              if (ipv6_addr_equal(&psf->sf_addr, src_addr))
                                    break;
                        }
                        if (psf)
                              rv = psf->sf_count[MCAST_INCLUDE] ||
                                    psf->sf_count[MCAST_EXCLUDE] !=
                                    mc->mca_sfcount[MCAST_EXCLUDE];
                        else
                              rv = mc->mca_sfcount[MCAST_EXCLUDE] !=0;
                        spin_unlock_bh(&mc->mca_lock);
                  } else
                        rv = 1; /* don't filter unspecified source */
            }
            read_unlock_bh(&idev->lock);
            in6_dev_put(idev);
      }
      return rv;
}

static void mld_gq_start_timer(struct inet6_dev *idev)
{
      int tv = net_random() % idev->mc_maxdelay;

      idev->mc_gq_running = 1;
      if (!mod_timer(&idev->mc_gq_timer, jiffies+tv+2))
            in6_dev_hold(idev);
}

static void mld_ifc_start_timer(struct inet6_dev *idev, int delay)
{
      int tv = net_random() % delay;

      if (!mod_timer(&idev->mc_ifc_timer, jiffies+tv+2))
            in6_dev_hold(idev);
}

/*
 *    IGMP handling (alias multicast ICMPv6 messages)
 */

static void igmp6_group_queried(struct ifmcaddr6 *ma, unsigned long resptime)
{
      unsigned long delay = resptime;

      /* Do not start timer for these addresses */
      if (ipv6_addr_is_ll_all_nodes(&ma->mca_addr) ||
          IPV6_ADDR_MC_SCOPE(&ma->mca_addr) < IPV6_ADDR_SCOPE_LINKLOCAL)
            return;

      if (del_timer(&ma->mca_timer)) {
            atomic_dec(&ma->mca_refcnt);
            delay = ma->mca_timer.expires - jiffies;
      }

      if (delay >= resptime) {
            if (resptime)
                  delay = net_random() % resptime;
            else
                  delay = 1;
      }
      ma->mca_timer.expires = jiffies + delay;
      if (!mod_timer(&ma->mca_timer, jiffies + delay))
            atomic_inc(&ma->mca_refcnt);
      ma->mca_flags |= MAF_TIMER_RUNNING;
}

/* mark EXCLUDE-mode sources */
static int mld_xmarksources(struct ifmcaddr6 *pmc, int nsrcs,
      struct in6_addr *srcs)
{
      struct ip6_sf_list *psf;
      int i, scount;

      scount = 0;
      for (psf=pmc->mca_sources; psf; psf=psf->sf_next) {
            if (scount == nsrcs)
                  break;
            for (i=0; i<nsrcs; i++) {
                  /* skip inactive filters */
                  if (pmc->mca_sfcount[MCAST_INCLUDE] ||
                      pmc->mca_sfcount[MCAST_EXCLUDE] !=
                      psf->sf_count[MCAST_EXCLUDE])
                        continue;
                  if (ipv6_addr_equal(&srcs[i], &psf->sf_addr)) {
                        scount++;
                        break;
                  }
            }
      }
      pmc->mca_flags &= ~MAF_GSQUERY;
      if (scount == nsrcs)    /* all sources excluded */
            return 0;
      return 1;
}

static int mld_marksources(struct ifmcaddr6 *pmc, int nsrcs,
      struct in6_addr *srcs)
{
      struct ip6_sf_list *psf;
      int i, scount;

      if (pmc->mca_sfmode == MCAST_EXCLUDE)
            return mld_xmarksources(pmc, nsrcs, srcs);

      /* mark INCLUDE-mode sources */

      scount = 0;
      for (psf=pmc->mca_sources; psf; psf=psf->sf_next) {
            if (scount == nsrcs)
                  break;
            for (i=0; i<nsrcs; i++) {
                  if (ipv6_addr_equal(&srcs[i], &psf->sf_addr)) {
                        psf->sf_gsresp = 1;
                        scount++;
                        break;
                  }
            }
      }
      if (!scount) {
            pmc->mca_flags &= ~MAF_GSQUERY;
            return 0;
      }
      pmc->mca_flags |= MAF_GSQUERY;
      return 1;
}

int igmp6_event_query(struct sk_buff *skb)
{
      struct mld2_query *mlh2 = NULL;
      struct ifmcaddr6 *ma;
      struct in6_addr *group;
      unsigned long max_delay;
      struct inet6_dev *idev;
      struct icmp6hdr *hdr;
      int group_type;
      int mark = 0;
      int len;

      if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
            return -EINVAL;

      /* compute payload length excluding extension headers */
      len = ntohs(ipv6_hdr(skb)->payload_len) + sizeof(struct ipv6hdr);
      len -= skb_network_header_len(skb);

      /* Drop queries with not link local source */
      if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL))
            return -EINVAL;

      idev = in6_dev_get(skb->dev);

      if (idev == NULL)
            return 0;

      hdr = icmp6_hdr(skb);
      group = (struct in6_addr *) (hdr + 1);
      group_type = ipv6_addr_type(group);

      if (group_type != IPV6_ADDR_ANY &&
          !(group_type&IPV6_ADDR_MULTICAST)) {
            in6_dev_put(idev);
            return -EINVAL;
      }

      if (len == 24) {
            int switchback;
            /* MLDv1 router present */

            /* Translate milliseconds to jiffies */
            max_delay = (ntohs(hdr->icmp6_maxdelay)*HZ)/1000;

            switchback = (idev->mc_qrv + 1) * max_delay;
            idev->mc_v1_seen = jiffies + switchback;

            /* cancel the interface change timer */
            idev->mc_ifc_count = 0;
            if (del_timer(&idev->mc_ifc_timer))
                  __in6_dev_put(idev);
            /* clear deleted report items */
            mld_clear_delrec(idev);
      } else if (len >= 28) {
            int srcs_offset = sizeof(struct mld2_query) -
                          sizeof(struct icmp6hdr);
            if (!pskb_may_pull(skb, srcs_offset)) {
                  in6_dev_put(idev);
                  return -EINVAL;
            }
            mlh2 = (struct mld2_query *)skb_transport_header(skb);
            max_delay = (MLDV2_MRC(ntohs(mlh2->mrc))*HZ)/1000;
            if (!max_delay)
                  max_delay = 1;
            idev->mc_maxdelay = max_delay;
            if (mlh2->qrv)
                  idev->mc_qrv = mlh2->qrv;
            if (group_type == IPV6_ADDR_ANY) { /* general query */
                  if (mlh2->nsrcs) {
                        in6_dev_put(idev);
                        return -EINVAL; /* no sources allowed */
                  }
                  mld_gq_start_timer(idev);
                  in6_dev_put(idev);
                  return 0;
            }
            /* mark sources to include, if group & source-specific */
            if (mlh2->nsrcs != 0) {
                  if (!pskb_may_pull(skb, srcs_offset +
                      ntohs(mlh2->nsrcs) * sizeof(struct in6_addr))) {
                        in6_dev_put(idev);
                        return -EINVAL;
                  }
                  mlh2 = (struct mld2_query *)skb_transport_header(skb);
                  mark = 1;
            }
      } else {
            in6_dev_put(idev);
            return -EINVAL;
      }

      read_lock_bh(&idev->lock);
      if (group_type == IPV6_ADDR_ANY) {
            for (ma = idev->mc_list; ma; ma=ma->next) {
                  spin_lock_bh(&ma->mca_lock);
                  igmp6_group_queried(ma, max_delay);
                  spin_unlock_bh(&ma->mca_lock);
            }
      } else {
            for (ma = idev->mc_list; ma; ma=ma->next) {
                  if (!ipv6_addr_equal(group, &ma->mca_addr))
                        continue;
                  spin_lock_bh(&ma->mca_lock);
                  if (ma->mca_flags & MAF_TIMER_RUNNING) {
                        /* gsquery <- gsquery && mark */
                        if (!mark)
                              ma->mca_flags &= ~MAF_GSQUERY;
                  } else {
                        /* gsquery <- mark */
                        if (mark)
                              ma->mca_flags |= MAF_GSQUERY;
                        else
                              ma->mca_flags &= ~MAF_GSQUERY;
                  }
                  if (!(ma->mca_flags & MAF_GSQUERY) ||
                      mld_marksources(ma, ntohs(mlh2->nsrcs), mlh2->srcs))
                        igmp6_group_queried(ma, max_delay);
                  spin_unlock_bh(&ma->mca_lock);
                  break;
            }
      }
      read_unlock_bh(&idev->lock);
      in6_dev_put(idev);

      return 0;
}


int igmp6_event_report(struct sk_buff *skb)
{
      struct ifmcaddr6 *ma;
      struct in6_addr *addrp;
      struct inet6_dev *idev;
      struct icmp6hdr *hdr;
      int addr_type;

      /* Our own report looped back. Ignore it. */
      if (skb->pkt_type == PACKET_LOOPBACK)
            return 0;

      /* send our report if the MC router may not have heard this report */
      if (skb->pkt_type != PACKET_MULTICAST &&
          skb->pkt_type != PACKET_BROADCAST)
            return 0;

      if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
            return -EINVAL;

      hdr = icmp6_hdr(skb);

      /* Drop reports with not link local source */
      addr_type = ipv6_addr_type(&ipv6_hdr(skb)->saddr);
      if (addr_type != IPV6_ADDR_ANY &&
          !(addr_type&IPV6_ADDR_LINKLOCAL))
            return -EINVAL;

      addrp = (struct in6_addr *) (hdr + 1);

      idev = in6_dev_get(skb->dev);
      if (idev == NULL)
            return -ENODEV;

      /*
       *    Cancel the timer for this group
       */

      read_lock_bh(&idev->lock);
      for (ma = idev->mc_list; ma; ma=ma->next) {
            if (ipv6_addr_equal(&ma->mca_addr, addrp)) {
                  spin_lock(&ma->mca_lock);
                  if (del_timer(&ma->mca_timer))
                        atomic_dec(&ma->mca_refcnt);
                  ma->mca_flags &= ~(MAF_LAST_REPORTER|MAF_TIMER_RUNNING);
                  spin_unlock(&ma->mca_lock);
                  break;
            }
      }
      read_unlock_bh(&idev->lock);
      in6_dev_put(idev);
      return 0;
}

static int is_in(struct ifmcaddr6 *pmc, struct ip6_sf_list *psf, int type,
      int gdeleted, int sdeleted)
{
      switch (type) {
      case MLD2_MODE_IS_INCLUDE:
      case MLD2_MODE_IS_EXCLUDE:
            if (gdeleted || sdeleted)
                  return 0;
            if (!((pmc->mca_flags & MAF_GSQUERY) && !psf->sf_gsresp)) {
                  if (pmc->mca_sfmode == MCAST_INCLUDE)
                        return 1;
                  /* don't include if this source is excluded
                   * in all filters
                   */
                  if (psf->sf_count[MCAST_INCLUDE])
                        return type == MLD2_MODE_IS_INCLUDE;
                  return pmc->mca_sfcount[MCAST_EXCLUDE] ==
                        psf->sf_count[MCAST_EXCLUDE];
            }
            return 0;
      case MLD2_CHANGE_TO_INCLUDE:
            if (gdeleted || sdeleted)
                  return 0;
            return psf->sf_count[MCAST_INCLUDE] != 0;
      case MLD2_CHANGE_TO_EXCLUDE:
            if (gdeleted || sdeleted)
                  return 0;
            if (pmc->mca_sfcount[MCAST_EXCLUDE] == 0 ||
                psf->sf_count[MCAST_INCLUDE])
                  return 0;
            return pmc->mca_sfcount[MCAST_EXCLUDE] ==
                  psf->sf_count[MCAST_EXCLUDE];
      case MLD2_ALLOW_NEW_SOURCES:
            if (gdeleted || !psf->sf_crcount)
                  return 0;
            return (pmc->mca_sfmode == MCAST_INCLUDE) ^ sdeleted;
      case MLD2_BLOCK_OLD_SOURCES:
            if (pmc->mca_sfmode == MCAST_INCLUDE)
                  return gdeleted || (psf->sf_crcount && sdeleted);
            return psf->sf_crcount && !gdeleted && !sdeleted;
      }
      return 0;
}

static int
mld_scount(struct ifmcaddr6 *pmc, int type, int gdeleted, int sdeleted)
{
      struct ip6_sf_list *psf;
      int scount = 0;

      for (psf=pmc->mca_sources; psf; psf=psf->sf_next) {
            if (!is_in(pmc, psf, type, gdeleted, sdeleted))
                  continue;
            scount++;
      }
      return scount;
}

static struct sk_buff *mld_newpack(struct net_device *dev, int size)
{
      struct sock *sk = igmp6_socket->sk;
      struct sk_buff *skb;
      struct mld2_report *pmr;
      struct in6_addr addr_buf;
      int err;
      u8 ra[8] = { IPPROTO_ICMPV6, 0,
                 IPV6_TLV_ROUTERALERT, 2, 0, 0,
                 IPV6_TLV_PADN, 0 };

      /* we assume size > sizeof(ra) here */
      skb = sock_alloc_send_skb(sk, size + LL_RESERVED_SPACE(dev), 1, &err);

      if (!skb)
            return NULL;

      skb_reserve(skb, LL_RESERVED_SPACE(dev));

      if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) {
            /* <draft-ietf-magma-mld-source-05.txt>:
             * use unspecified address as the source address
             * when a valid link-local address is not available.
             */
            memset(&addr_buf, 0, sizeof(addr_buf));
      }

      ip6_nd_hdr(sk, skb, dev, &addr_buf, &mld2_all_mcr, NEXTHDR_HOP, 0);

      memcpy(skb_put(skb, sizeof(ra)), ra, sizeof(ra));

      skb_set_transport_header(skb, skb_tail_pointer(skb) - skb->data);
      skb_put(skb, sizeof(*pmr));
      pmr = (struct mld2_report *)skb_transport_header(skb);
      pmr->type = ICMPV6_MLD2_REPORT;
      pmr->resv1 = 0;
      pmr->csum = 0;
      pmr->resv2 = 0;
      pmr->ngrec = 0;
      return skb;
}

static inline int mld_dev_queue_xmit2(struct sk_buff *skb)
{
      struct net_device *dev = skb->dev;
      unsigned char ha[MAX_ADDR_LEN];

      ndisc_mc_map(&ipv6_hdr(skb)->daddr, ha, dev, 1);
      if (dev_hard_header(skb, dev, ETH_P_IPV6, ha, NULL, skb->len) < 0) {
            kfree_skb(skb);
            return -EINVAL;
      }
      return dev_queue_xmit(skb);
}

static inline int mld_dev_queue_xmit(struct sk_buff *skb)
{
      return NF_HOOK(PF_INET6, NF_IP6_POST_ROUTING, skb, NULL, skb->dev,
                   mld_dev_queue_xmit2);
}

static void mld_sendpack(struct sk_buff *skb)
{
      struct ipv6hdr *pip6 = ipv6_hdr(skb);
      struct mld2_report *pmr =
                        (struct mld2_report *)skb_transport_header(skb);
      int payload_len, mldlen;
      struct inet6_dev *idev = in6_dev_get(skb->dev);
      int err;

      IP6_INC_STATS(idev, IPSTATS_MIB_OUTREQUESTS);
      payload_len = (skb->tail - skb->network_header) - sizeof(*pip6);
      mldlen = skb->tail - skb->transport_header;
      pip6->payload_len = htons(payload_len);

      pmr->csum = csum_ipv6_magic(&pip6->saddr, &pip6->daddr, mldlen,
            IPPROTO_ICMPV6, csum_partial(skb_transport_header(skb),
                                   mldlen, 0));
      err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dev,
            mld_dev_queue_xmit);
      if (!err) {
            ICMP6MSGOUT_INC_STATS_BH(idev, ICMPV6_MLD2_REPORT);
            ICMP6_INC_STATS_BH(idev, ICMP6_MIB_OUTMSGS);
            IP6_INC_STATS_BH(idev, IPSTATS_MIB_OUTMCASTPKTS);
      } else
            IP6_INC_STATS_BH(idev, IPSTATS_MIB_OUTDISCARDS);

      if (likely(idev != NULL))
            in6_dev_put(idev);
}

static int grec_size(struct ifmcaddr6 *pmc, int type, int gdel, int sdel)
{
      return sizeof(struct mld2_grec) + 16 * mld_scount(pmc,type,gdel,sdel);
}

static struct sk_buff *add_grhead(struct sk_buff *skb, struct ifmcaddr6 *pmc,
      int type, struct mld2_grec **ppgr)
{
      struct net_device *dev = pmc->idev->dev;
      struct mld2_report *pmr;
      struct mld2_grec *pgr;

      if (!skb)
            skb = mld_newpack(dev, dev->mtu);
      if (!skb)
            return NULL;
      pgr = (struct mld2_grec *)skb_put(skb, sizeof(struct mld2_grec));
      pgr->grec_type = type;
      pgr->grec_auxwords = 0;
      pgr->grec_nsrcs = 0;
      pgr->grec_mca = pmc->mca_addr;      /* structure copy */
      pmr = (struct mld2_report *)skb_transport_header(skb);
      pmr->ngrec = htons(ntohs(pmr->ngrec)+1);
      *ppgr = pgr;
      return skb;
}

#define AVAILABLE(skb) ((skb) ? ((skb)->dev ? (skb)->dev->mtu - (skb)->len : \
      skb_tailroom(skb)) : 0)

static struct sk_buff *add_grec(struct sk_buff *skb, struct ifmcaddr6 *pmc,
      int type, int gdeleted, int sdeleted)
{
      struct net_device *dev = pmc->idev->dev;
      struct mld2_report *pmr;
      struct mld2_grec *pgr = NULL;
      struct ip6_sf_list *psf, *psf_next, *psf_prev, **psf_list;
      int scount, stotal, first, isquery, truncate;

      if (pmc->mca_flags & MAF_NOREPORT)
            return skb;

      isquery = type == MLD2_MODE_IS_INCLUDE ||
              type == MLD2_MODE_IS_EXCLUDE;
      truncate = type == MLD2_MODE_IS_EXCLUDE ||
                type == MLD2_CHANGE_TO_EXCLUDE;

      stotal = scount = 0;

      psf_list = sdeleted ? &pmc->mca_tomb : &pmc->mca_sources;

      if (!*psf_list)
            goto empty_source;

      pmr = skb ? (struct mld2_report *)skb_transport_header(skb) : NULL;

      /* EX and TO_EX get a fresh packet, if needed */
      if (truncate) {
            if (pmr && pmr->ngrec &&
                AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
                  if (skb)
                        mld_sendpack(skb);
                  skb = mld_newpack(dev, dev->mtu);
            }
      }
      first = 1;
      psf_prev = NULL;
      for (psf=*psf_list; psf; psf=psf_next) {
            struct in6_addr *psrc;

            psf_next = psf->sf_next;

            if (!is_in(pmc, psf, type, gdeleted, sdeleted)) {
                  psf_prev = psf;
                  continue;
            }

            /* clear marks on query responses */
            if (isquery)
                  psf->sf_gsresp = 0;

            if (AVAILABLE(skb) < sizeof(*psrc) +
                first*sizeof(struct mld2_grec)) {
                  if (truncate && !first)
                        break;       /* truncate these */
                  if (pgr)
                        pgr->grec_nsrcs = htons(scount);
                  if (skb)
                        mld_sendpack(skb);
                  skb = mld_newpack(dev, dev->mtu);
                  first = 1;
                  scount = 0;
            }
            if (first) {
                  skb = add_grhead(skb, pmc, type, &pgr);
                  first = 0;
            }
            if (!skb)
                  return NULL;
            psrc = (struct in6_addr *)skb_put(skb, sizeof(*psrc));
            *psrc = psf->sf_addr;
            scount++; stotal++;
            if ((type == MLD2_ALLOW_NEW_SOURCES ||
                 type == MLD2_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
                  psf->sf_crcount--;
                  if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
                        if (psf_prev)
                              psf_prev->sf_next = psf->sf_next;
                        else
                              *psf_list = psf->sf_next;
                        kfree(psf);
                        continue;
                  }
            }
            psf_prev = psf;
      }

empty_source:
      if (!stotal) {
            if (type == MLD2_ALLOW_NEW_SOURCES ||
                type == MLD2_BLOCK_OLD_SOURCES)
                  return skb;
            if (pmc->mca_crcount || isquery) {
                  /* make sure we have room for group header */
                  if (skb && AVAILABLE(skb) < sizeof(struct mld2_grec)) {
                        mld_sendpack(skb);
                        skb = NULL; /* add_grhead will get a new one */
                  }
                  skb = add_grhead(skb, pmc, type, &pgr);
            }
      }
      if (pgr)
            pgr->grec_nsrcs = htons(scount);

      if (isquery)
            pmc->mca_flags &= ~MAF_GSQUERY;     /* clear query state */
      return skb;
}

static void mld_send_report(struct inet6_dev *idev, struct ifmcaddr6 *pmc)
{
      struct sk_buff *skb = NULL;
      int type;

      if (!pmc) {
            read_lock_bh(&idev->lock);
            for (pmc=idev->mc_list; pmc; pmc=pmc->next) {
                  if (pmc->mca_flags & MAF_NOREPORT)
                        continue;
                  spin_lock_bh(&pmc->mca_lock);
                  if (pmc->mca_sfcount[MCAST_EXCLUDE])
                        type = MLD2_MODE_IS_EXCLUDE;
                  else
                        type = MLD2_MODE_IS_INCLUDE;
                  skb = add_grec(skb, pmc, type, 0, 0);
                  spin_unlock_bh(&pmc->mca_lock);
            }
            read_unlock_bh(&idev->lock);
      } else {
            spin_lock_bh(&pmc->mca_lock);
            if (pmc->mca_sfcount[MCAST_EXCLUDE])
                  type = MLD2_MODE_IS_EXCLUDE;
            else
                  type = MLD2_MODE_IS_INCLUDE;
            skb = add_grec(skb, pmc, type, 0, 0);
            spin_unlock_bh(&pmc->mca_lock);
      }
      if (skb)
            mld_sendpack(skb);
}

/*
 * remove zero-count source records from a source filter list
 */
static void mld_clear_zeros(struct ip6_sf_list **ppsf)
{
      struct ip6_sf_list *psf_prev, *psf_next, *psf;

      psf_prev = NULL;
      for (psf=*ppsf; psf; psf = psf_next) {
            psf_next = psf->sf_next;
            if (psf->sf_crcount == 0) {
                  if (psf_prev)
                        psf_prev->sf_next = psf->sf_next;
                  else
                        *ppsf = psf->sf_next;
                  kfree(psf);
            } else
                  psf_prev = psf;
      }
}

static void mld_send_cr(struct inet6_dev *idev)
{
      struct ifmcaddr6 *pmc, *pmc_prev, *pmc_next;
      struct sk_buff *skb = NULL;
      int type, dtype;

      read_lock_bh(&idev->lock);
      write_lock_bh(&idev->mc_lock);

      /* deleted MCA's */
      pmc_prev = NULL;
      for (pmc=idev->mc_tomb; pmc; pmc=pmc_next) {
            pmc_next = pmc->next;
            if (pmc->mca_sfmode == MCAST_INCLUDE) {
                  type = MLD2_BLOCK_OLD_SOURCES;
                  dtype = MLD2_BLOCK_OLD_SOURCES;
                  skb = add_grec(skb, pmc, type, 1, 0);
                  skb = add_grec(skb, pmc, dtype, 1, 1);
            }
            if (pmc->mca_crcount) {
                  if (pmc->mca_sfmode == MCAST_EXCLUDE) {
                        type = MLD2_CHANGE_TO_INCLUDE;
                        skb = add_grec(skb, pmc, type, 1, 0);
                  }
                  pmc->mca_crcount--;
                  if (pmc->mca_crcount == 0) {
                        mld_clear_zeros(&pmc->mca_tomb);
                        mld_clear_zeros(&pmc->mca_sources);
                  }
            }
            if (pmc->mca_crcount == 0 && !pmc->mca_tomb &&
                !pmc->mca_sources) {
                  if (pmc_prev)
                        pmc_prev->next = pmc_next;
                  else
                        idev->mc_tomb = pmc_next;
                  in6_dev_put(pmc->idev);
                  kfree(pmc);
            } else
                  pmc_prev = pmc;
      }
      write_unlock_bh(&idev->mc_lock);

      /* change recs */
      for (pmc=idev->mc_list; pmc; pmc=pmc->next) {
            spin_lock_bh(&pmc->mca_lock);
            if (pmc->mca_sfcount[MCAST_EXCLUDE]) {
                  type = MLD2_BLOCK_OLD_SOURCES;
                  dtype = MLD2_ALLOW_NEW_SOURCES;
            } else {
                  type = MLD2_ALLOW_NEW_SOURCES;
                  dtype = MLD2_BLOCK_OLD_SOURCES;
            }
            skb = add_grec(skb, pmc, type, 0, 0);
            skb = add_grec(skb, pmc, dtype, 0, 1);    /* deleted sources */

            /* filter mode changes */
            if (pmc->mca_crcount) {
                  if (pmc->mca_sfmode == MCAST_EXCLUDE)
                        type = MLD2_CHANGE_TO_EXCLUDE;
                  else
                        type = MLD2_CHANGE_TO_INCLUDE;
                  skb = add_grec(skb, pmc, type, 0, 0);
                  pmc->mca_crcount--;
            }
            spin_unlock_bh(&pmc->mca_lock);
      }
      read_unlock_bh(&idev->lock);
      if (!skb)
            return;
      (void) mld_sendpack(skb);
}

static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
{
      struct sock *sk = igmp6_socket->sk;
      struct inet6_dev *idev;
      struct sk_buff *skb;
      struct icmp6hdr *hdr;
      struct in6_addr *snd_addr;
      struct in6_addr *addrp;
      struct in6_addr addr_buf;
      struct in6_addr all_routers;
      int err, len, payload_len, full_len;
      u8 ra[8] = { IPPROTO_ICMPV6, 0,
                 IPV6_TLV_ROUTERALERT, 2, 0, 0,
                 IPV6_TLV_PADN, 0 };

      rcu_read_lock();
      IP6_INC_STATS(__in6_dev_get(dev),
                  IPSTATS_MIB_OUTREQUESTS);
      rcu_read_unlock();
      snd_addr = addr;
      if (type == ICMPV6_MGM_REDUCTION) {
            snd_addr = &all_routers;
            ipv6_addr_all_routers(&all_routers);
      }

      len = sizeof(struct icmp6hdr) + sizeof(struct in6_addr);
      payload_len = len + sizeof(ra);
      full_len = sizeof(struct ipv6hdr) + payload_len;

      skb = sock_alloc_send_skb(sk, LL_RESERVED_SPACE(dev) + full_len, 1, &err);

      if (skb == NULL) {
            rcu_read_lock();
            IP6_INC_STATS(__in6_dev_get(dev),
                        IPSTATS_MIB_OUTDISCARDS);
            rcu_read_unlock();
            return;
      }

      skb_reserve(skb, LL_RESERVED_SPACE(dev));

      if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) {
            /* <draft-ietf-magma-mld-source-05.txt>:
             * use unspecified address as the source address
             * when a valid link-local address is not available.
             */
            memset(&addr_buf, 0, sizeof(addr_buf));
      }

      ip6_nd_hdr(sk, skb, dev, &addr_buf, snd_addr, NEXTHDR_HOP, payload_len);

      memcpy(skb_put(skb, sizeof(ra)), ra, sizeof(ra));

      hdr = (struct icmp6hdr *) skb_put(skb, sizeof(struct icmp6hdr));
      memset(hdr, 0, sizeof(struct icmp6hdr));
      hdr->icmp6_type = type;

      addrp = (struct in6_addr *) skb_put(skb, sizeof(struct in6_addr));
      ipv6_addr_copy(addrp, addr);

      hdr->icmp6_cksum = csum_ipv6_magic(&addr_buf, snd_addr, len,
                                 IPPROTO_ICMPV6,
                                 csum_partial((__u8 *) hdr, len, 0));

      idev = in6_dev_get(skb->dev);

      err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, skb->dev,
            mld_dev_queue_xmit);
      if (!err) {
            ICMP6MSGOUT_INC_STATS(idev, type);
            ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
            IP6_INC_STATS(idev, IPSTATS_MIB_OUTMCASTPKTS);
      } else
            IP6_INC_STATS(idev, IPSTATS_MIB_OUTDISCARDS);

      if (likely(idev != NULL))
            in6_dev_put(idev);
      return;
}

static int ip6_mc_del1_src(struct ifmcaddr6 *pmc, int sfmode,
      struct in6_addr *psfsrc)
{
      struct ip6_sf_list *psf, *psf_prev;
      int rv = 0;

      psf_prev = NULL;
      for (psf=pmc->mca_sources; psf; psf=psf->sf_next) {
            if (ipv6_addr_equal(&psf->sf_addr, psfsrc))
                  break;
            psf_prev = psf;
      }
      if (!psf || psf->sf_count[sfmode] == 0) {
            /* source filter not found, or count wrong =>  bug */
            return -ESRCH;
      }
      psf->sf_count[sfmode]--;
      if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
            struct inet6_dev *idev = pmc->idev;

            /* no more filters for this source */
            if (psf_prev)
                  psf_prev->sf_next = psf->sf_next;
            else
                  pmc->mca_sources = psf->sf_next;
            if (psf->sf_oldin && !(pmc->mca_flags & MAF_NOREPORT) &&
                !MLD_V1_SEEN(idev)) {
                  psf->sf_crcount = idev->mc_qrv;
                  psf->sf_next = pmc->mca_tomb;
                  pmc->mca_tomb = psf;
                  rv = 1;
            } else
                  kfree(psf);
      }
      return rv;
}

static int ip6_mc_del_src(struct inet6_dev *idev, struct in6_addr *pmca,
                    int sfmode, int sfcount, struct in6_addr *psfsrc,
                    int delta)
{
      struct ifmcaddr6 *pmc;
      int   changerec = 0;
      int   i, err;

      if (!idev)
            return -ENODEV;
      read_lock_bh(&idev->lock);
      for (pmc=idev->mc_list; pmc; pmc=pmc->next) {
            if (ipv6_addr_equal(pmca, &pmc->mca_addr))
                  break;
      }
      if (!pmc) {
            /* MCA not found?? bug */
            read_unlock_bh(&idev->lock);
            return -ESRCH;
      }
      spin_lock_bh(&pmc->mca_lock);
      sf_markstate(pmc);
      if (!delta) {
            if (!pmc->mca_sfcount[sfmode]) {
                  spin_unlock_bh(&pmc->mca_lock);
                  read_unlock_bh(&idev->lock);
                  return -EINVAL;
            }
            pmc->mca_sfcount[sfmode]--;
      }
      err = 0;
      for (i=0; i<sfcount; i++) {
            int rv = ip6_mc_del1_src(pmc, sfmode, &psfsrc[i]);

            changerec |= rv > 0;
            if (!err && rv < 0)
                  err = rv;
      }
      if (pmc->mca_sfmode == MCAST_EXCLUDE &&
          pmc->mca_sfcount[MCAST_EXCLUDE] == 0 &&
          pmc->mca_sfcount[MCAST_INCLUDE]) {
            struct ip6_sf_list *psf;

            /* filter mode change */
            pmc->mca_sfmode = MCAST_INCLUDE;
            pmc->mca_crcount = idev->mc_qrv;
            idev->mc_ifc_count = pmc->mca_crcount;
            for (psf=pmc->mca_sources; psf; psf = psf->sf_next)
                  psf->sf_crcount = 0;
            mld_ifc_event(pmc->idev);
      } else if (sf_setstate(pmc) || changerec)
            mld_ifc_event(pmc->idev);
      spin_unlock_bh(&pmc->mca_lock);
      read_unlock_bh(&idev->lock);
      return err;
}

/*
 * Add multicast single-source filter to the interface list
 */
static int ip6_mc_add1_src(struct ifmcaddr6 *pmc, int sfmode,
      struct in6_addr *psfsrc, int delta)
{
      struct ip6_sf_list *psf, *psf_prev;

      psf_prev = NULL;
      for (psf=pmc->mca_sources; psf; psf=psf->sf_next) {
            if (ipv6_addr_equal(&psf->sf_addr, psfsrc))
                  break;
            psf_prev = psf;
      }
      if (!psf) {
            psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
            if (!psf)
                  return -ENOBUFS;

            psf->sf_addr = *psfsrc;
            if (psf_prev) {
                  psf_prev->sf_next = psf;
            } else
                  pmc->mca_sources = psf;
      }
      psf->sf_count[sfmode]++;
      return 0;
}

static void sf_markstate(struct ifmcaddr6 *pmc)
{
      struct ip6_sf_list *psf;
      int mca_xcount = pmc->mca_sfcount[MCAST_EXCLUDE];

      for (psf=pmc->mca_sources; psf; psf=psf->sf_next)
            if (pmc->mca_sfcount[MCAST_EXCLUDE]) {
                  psf->sf_oldin = mca_xcount ==
                        psf->sf_count[MCAST_EXCLUDE] &&
                        !psf->sf_count[MCAST_INCLUDE];
            } else
                  psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
}

static int sf_setstate(struct ifmcaddr6 *pmc)
{
      struct ip6_sf_list *psf, *dpsf;
      int mca_xcount = pmc->mca_sfcount[MCAST_EXCLUDE];
      int qrv = pmc->idev->mc_qrv;
      int new_in, rv;

      rv = 0;
      for (psf=pmc->mca_sources; psf; psf=psf->sf_next) {
            if (pmc->mca_sfcount[MCAST_EXCLUDE]) {
                  new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
                        !psf->sf_count[MCAST_INCLUDE];
            } else
                  new_in = psf->sf_count[MCAST_INCLUDE] != 0;
            if (new_in) {
                  if (!psf->sf_oldin) {
                        struct ip6_sf_list *prev = NULL;

                        for (dpsf=pmc->mca_tomb; dpsf;
                             dpsf=dpsf->sf_next) {
                              if (ipv6_addr_equal(&dpsf->sf_addr,
                                  &psf->sf_addr))
                                    break;
                              prev = dpsf;
                        }
                        if (dpsf) {
                              if (prev)
                                    prev->sf_next = dpsf->sf_next;
                              else
                                    pmc->mca_tomb = dpsf->sf_next;
                              kfree(dpsf);
                        }
                        psf->sf_crcount = qrv;
                        rv++;
                  }
            } else if (psf->sf_oldin) {
                  psf->sf_crcount = 0;
                  /*
                   * add or update "delete" records if an active filter
                   * is now inactive
                   */
                  for (dpsf=pmc->mca_tomb; dpsf; dpsf=dpsf->sf_next)
                        if (ipv6_addr_equal(&dpsf->sf_addr,
                            &psf->sf_addr))
                              break;
                  if (!dpsf) {
                        dpsf = (struct ip6_sf_list *)
                              kmalloc(sizeof(*dpsf), GFP_ATOMIC);
                        if (!dpsf)
                              continue;
                        *dpsf = *psf;
                        /* pmc->mca_lock held by callers */
                        dpsf->sf_next = pmc->mca_tomb;
                        pmc->mca_tomb = dpsf;
                  }
                  dpsf->sf_crcount = qrv;
                  rv++;
            }
      }
      return rv;
}

/*
 * Add multicast source filter list to the interface list
 */
static int ip6_mc_add_src(struct inet6_dev *idev, struct in6_addr *pmca,
                    int sfmode, int sfcount, struct in6_addr *psfsrc,
                    int delta)
{
      struct ifmcaddr6 *pmc;
      int   isexclude;
      int   i, err;

      if (!idev)
            return -ENODEV;
      read_lock_bh(&idev->lock);
      for (pmc=idev->mc_list; pmc; pmc=pmc->next) {
            if (ipv6_addr_equal(pmca, &pmc->mca_addr))
                  break;
      }
      if (!pmc) {
            /* MCA not found?? bug */
            read_unlock_bh(&idev->lock);
            return -ESRCH;
      }
      spin_lock_bh(&pmc->mca_lock);

      sf_markstate(pmc);
      isexclude = pmc->mca_sfmode == MCAST_EXCLUDE;
      if (!delta)
            pmc->mca_sfcount[sfmode]++;
      err = 0;
      for (i=0; i<sfcount; i++) {
            err = ip6_mc_add1_src(pmc, sfmode, &psfsrc[i], delta);
            if (err)
                  break;
      }
      if (err) {
            int j;

            if (!delta)
                  pmc->mca_sfcount[sfmode]--;
            for (j=0; j<i; j++)
                  (void) ip6_mc_del1_src(pmc, sfmode, &psfsrc[i]);
      } else if (isexclude != (pmc->mca_sfcount[MCAST_EXCLUDE] != 0)) {
            struct inet6_dev *idev = pmc->idev;
            struct ip6_sf_list *psf;

            /* filter mode change */
            if (pmc->mca_sfcount[MCAST_EXCLUDE])
                  pmc->mca_sfmode = MCAST_EXCLUDE;
            else if (pmc->mca_sfcount[MCAST_INCLUDE])
                  pmc->mca_sfmode = MCAST_INCLUDE;
            /* else no filters; keep old mode for reports */

            pmc->mca_crcount = idev->mc_qrv;
            idev->mc_ifc_count = pmc->mca_crcount;
            for (psf=pmc->mca_sources; psf; psf = psf->sf_next)
                  psf->sf_crcount = 0;
            mld_ifc_event(idev);
      } else if (sf_setstate(pmc))
            mld_ifc_event(idev);
      spin_unlock_bh(&pmc->mca_lock);
      read_unlock_bh(&idev->lock);
      return err;
}

static void ip6_mc_clear_src(struct ifmcaddr6 *pmc)
{
      struct ip6_sf_list *psf, *nextpsf;

      for (psf=pmc->mca_tomb; psf; psf=nextpsf) {
            nextpsf = psf->sf_next;
            kfree(psf);
      }
      pmc->mca_tomb = NULL;
      for (psf=pmc->mca_sources; psf; psf=nextpsf) {
            nextpsf = psf->sf_next;
            kfree(psf);
      }
      pmc->mca_sources = NULL;
      pmc->mca_sfmode = MCAST_EXCLUDE;
      pmc->mca_sfcount[MCAST_INCLUDE] = 0;
      pmc->mca_sfcount[MCAST_EXCLUDE] = 1;
}


static void igmp6_join_group(struct ifmcaddr6 *ma)
{
      unsigned long delay;

      if (ma->mca_flags & MAF_NOREPORT)
            return;

      igmp6_send(&ma->mca_addr, ma->idev->dev, ICMPV6_MGM_REPORT);

      delay = net_random() % IGMP6_UNSOLICITED_IVAL;

      spin_lock_bh(&ma->mca_lock);
      if (del_timer(&ma->mca_timer)) {
            atomic_dec(&ma->mca_refcnt);
            delay = ma->mca_timer.expires - jiffies;
      }

      if (!mod_timer(&ma->mca_timer, jiffies + delay))
            atomic_inc(&ma->mca_refcnt);
      ma->mca_flags |= MAF_TIMER_RUNNING | MAF_LAST_REPORTER;
      spin_unlock_bh(&ma->mca_lock);
}

static int ip6_mc_leave_src(struct sock *sk, struct ipv6_mc_socklist *iml,
                      struct inet6_dev *idev)
{
      int err;

      /* callers have the socket lock and a write lock on ipv6_sk_mc_lock,
       * so no other readers or writers of iml or its sflist
       */
      if (!iml->sflist) {
            /* any-source empty exclude case */
            return ip6_mc_del_src(idev, &iml->addr, iml->sfmode, 0, NULL, 0);
      }
      err = ip6_mc_del_src(idev, &iml->addr, iml->sfmode,
            iml->sflist->sl_count, iml->sflist->sl_addr, 0);
      sock_kfree_s(sk, iml->sflist, IP6_SFLSIZE(iml->sflist->sl_max));
      iml->sflist = NULL;
      return err;
}

static void igmp6_leave_group(struct ifmcaddr6 *ma)
{
      if (MLD_V1_SEEN(ma->idev)) {
            if (ma->mca_flags & MAF_LAST_REPORTER)
                  igmp6_send(&ma->mca_addr, ma->idev->dev,
                        ICMPV6_MGM_REDUCTION);
      } else {
            mld_add_delrec(ma->idev, ma);
            mld_ifc_event(ma->idev);
      }
}

static void mld_gq_timer_expire(unsigned long data)
{
      struct inet6_dev *idev = (struct inet6_dev *)data;

      idev->mc_gq_running = 0;
      mld_send_report(idev, NULL);
      __in6_dev_put(idev);
}

static void mld_ifc_timer_expire(unsigned long data)
{
      struct inet6_dev *idev = (struct inet6_dev *)data;

      mld_send_cr(idev);
      if (idev->mc_ifc_count) {
            idev->mc_ifc_count--;
            if (idev->mc_ifc_count)
                  mld_ifc_start_timer(idev, idev->mc_maxdelay);
      }
      __in6_dev_put(idev);
}

static void mld_ifc_event(struct inet6_dev *idev)
{
      if (MLD_V1_SEEN(idev))
            return;
      idev->mc_ifc_count = idev->mc_qrv;
      mld_ifc_start_timer(idev, 1);
}


static void igmp6_timer_handler(unsigned long data)
{
      struct ifmcaddr6 *ma = (struct ifmcaddr6 *) data;

      if (MLD_V1_SEEN(ma->idev))
            igmp6_send(&ma->mca_addr, ma->idev->dev, ICMPV6_MGM_REPORT);
      else
            mld_send_report(ma->idev, ma);

      spin_lock(&ma->mca_lock);
      ma->mca_flags |=  MAF_LAST_REPORTER;
      ma->mca_flags &= ~MAF_TIMER_RUNNING;
      spin_unlock(&ma->mca_lock);
      ma_put(ma);
}

/* Device going down */

void ipv6_mc_down(struct inet6_dev *idev)
{
      struct ifmcaddr6 *i;

      /* Withdraw multicast list */

      read_lock_bh(&idev->lock);
      idev->mc_ifc_count = 0;
      if (del_timer(&idev->mc_ifc_timer))
            __in6_dev_put(idev);
      idev->mc_gq_running = 0;
      if (del_timer(&idev->mc_gq_timer))
            __in6_dev_put(idev);

      for (i = idev->mc_list; i; i=i->next)
            igmp6_group_dropped(i);
      read_unlock_bh(&idev->lock);

      mld_clear_delrec(idev);
}


/* Device going up */

void ipv6_mc_up(struct inet6_dev *idev)
{
      struct ifmcaddr6 *i;

      /* Install multicast list, except for all-nodes (already installed) */

      read_lock_bh(&idev->lock);
      for (i = idev->mc_list; i; i=i->next)
            igmp6_group_added(i);
      read_unlock_bh(&idev->lock);
}

/* IPv6 device initialization. */

void ipv6_mc_init_dev(struct inet6_dev *idev)
{
      write_lock_bh(&idev->lock);
      rwlock_init(&idev->mc_lock);
      idev->mc_gq_running = 0;
      init_timer(&idev->mc_gq_timer);
      idev->mc_gq_timer.data = (unsigned long) idev;
      idev->mc_gq_timer.function = &mld_gq_timer_expire;
      idev->mc_tomb = NULL;
      idev->mc_ifc_count = 0;
      init_timer(&idev->mc_ifc_timer);
      idev->mc_ifc_timer.data = (unsigned long) idev;
      idev->mc_ifc_timer.function = &mld_ifc_timer_expire;
      idev->mc_qrv = MLD_QRV_DEFAULT;
      idev->mc_maxdelay = IGMP6_UNSOLICITED_IVAL;
      idev->mc_v1_seen = 0;
      write_unlock_bh(&idev->lock);
}

/*
 *    Device is about to be destroyed: clean up.
 */

void ipv6_mc_destroy_dev(struct inet6_dev *idev)
{
      struct ifmcaddr6 *i;
      struct in6_addr maddr;

      /* Deactivate timers */
      ipv6_mc_down(idev);

      /* Delete all-nodes address. */
      ipv6_addr_all_nodes(&maddr);

      /* We cannot call ipv6_dev_mc_dec() directly, our caller in
       * addrconf.c has NULL'd out dev->ip6_ptr so in6_dev_get() will
       * fail.
       */
      __ipv6_dev_mc_dec(idev, &maddr);

      if (idev->cnf.forwarding) {
            ipv6_addr_all_routers(&maddr);
            __ipv6_dev_mc_dec(idev, &maddr);
      }

      write_lock_bh(&idev->lock);
      while ((i = idev->mc_list) != NULL) {
            idev->mc_list = i->next;
            write_unlock_bh(&idev->lock);

            igmp6_group_dropped(i);
            ma_put(i);

            write_lock_bh(&idev->lock);
      }
      write_unlock_bh(&idev->lock);
}

#ifdef CONFIG_PROC_FS
struct igmp6_mc_iter_state {
      struct net_device *dev;
      struct inet6_dev *idev;
};

#define igmp6_mc_seq_private(seq)   ((struct igmp6_mc_iter_state *)(seq)->private)

static inline struct ifmcaddr6 *igmp6_mc_get_first(struct seq_file *seq)
{
      struct ifmcaddr6 *im = NULL;
      struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);

      state->idev = NULL;
      for_each_netdev(&init_net, state->dev) {
            struct inet6_dev *idev;
            idev = in6_dev_get(state->dev);
            if (!idev)
                  continue;
            read_lock_bh(&idev->lock);
            im = idev->mc_list;
            if (im) {
                  state->idev = idev;
                  break;
            }
            read_unlock_bh(&idev->lock);
            in6_dev_put(idev);
      }
      return im;
}

static struct ifmcaddr6 *igmp6_mc_get_next(struct seq_file *seq, struct ifmcaddr6 *im)
{
      struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);

      im = im->next;
      while (!im) {
            if (likely(state->idev != NULL)) {
                  read_unlock_bh(&state->idev->lock);
                  in6_dev_put(state->idev);
            }
            state->dev = next_net_device(state->dev);
            if (!state->dev) {
                  state->idev = NULL;
                  break;
            }
            state->idev = in6_dev_get(state->dev);
            if (!state->idev)
                  continue;
            read_lock_bh(&state->idev->lock);
            im = state->idev->mc_list;
      }
      return im;
}

static struct ifmcaddr6 *igmp6_mc_get_idx(struct seq_file *seq, loff_t pos)
{
      struct ifmcaddr6 *im = igmp6_mc_get_first(seq);
      if (im)
            while (pos && (im = igmp6_mc_get_next(seq, im)) != NULL)
                  --pos;
      return pos ? NULL : im;
}

static void *igmp6_mc_seq_start(struct seq_file *seq, loff_t *pos)
{
      read_lock(&dev_base_lock);
      return igmp6_mc_get_idx(seq, *pos);
}

static void *igmp6_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
      struct ifmcaddr6 *im;
      im = igmp6_mc_get_next(seq, v);
      ++*pos;
      return im;
}

static void igmp6_mc_seq_stop(struct seq_file *seq, void *v)
{
      struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
      if (likely(state->idev != NULL)) {
            read_unlock_bh(&state->idev->lock);
            in6_dev_put(state->idev);
            state->idev = NULL;
      }
      state->dev = NULL;
      read_unlock(&dev_base_lock);
}

static int igmp6_mc_seq_show(struct seq_file *seq, void *v)
{
      struct ifmcaddr6 *im = (struct ifmcaddr6 *)v;
      struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);

      seq_printf(seq,
               "%-4d %-15s " NIP6_SEQFMT " %5d %08X %ld\n",
               state->dev->ifindex, state->dev->name,
               NIP6(im->mca_addr),
               im->mca_users, im->mca_flags,
               (im->mca_flags&MAF_TIMER_RUNNING) ?
               jiffies_to_clock_t(im->mca_timer.expires-jiffies) : 0);
      return 0;
}

static const struct seq_operations igmp6_mc_seq_ops = {
      .start      =     igmp6_mc_seq_start,
      .next =     igmp6_mc_seq_next,
      .stop =     igmp6_mc_seq_stop,
      .show =     igmp6_mc_seq_show,
};

static int igmp6_mc_seq_open(struct inode *inode, struct file *file)
{
      return seq_open_private(file, &igmp6_mc_seq_ops,
                  sizeof(struct igmp6_mc_iter_state));
}

static const struct file_operations igmp6_mc_seq_fops = {
      .owner            =     THIS_MODULE,
      .open       =     igmp6_mc_seq_open,
      .read       =     seq_read,
      .llseek           =     seq_lseek,
      .release    =     seq_release_private,
};

struct igmp6_mcf_iter_state {
      struct net_device *dev;
      struct inet6_dev *idev;
      struct ifmcaddr6 *im;
};

#define igmp6_mcf_seq_private(seq)  ((struct igmp6_mcf_iter_state *)(seq)->private)

static inline struct ip6_sf_list *igmp6_mcf_get_first(struct seq_file *seq)
{
      struct ip6_sf_list *psf = NULL;
      struct ifmcaddr6 *im = NULL;
      struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);

      state->idev = NULL;
      state->im = NULL;
      for_each_netdev(&init_net, state->dev) {
            struct inet6_dev *idev;
            idev = in6_dev_get(state->dev);
            if (unlikely(idev == NULL))
                  continue;
            read_lock_bh(&idev->lock);
            im = idev->mc_list;
            if (likely(im != NULL)) {
                  spin_lock_bh(&im->mca_lock);
                  psf = im->mca_sources;
                  if (likely(psf != NULL)) {
                        state->im = im;
                        state->idev = idev;
                        break;
                  }
                  spin_unlock_bh(&im->mca_lock);
            }
            read_unlock_bh(&idev->lock);
            in6_dev_put(idev);
      }
      return psf;
}

static struct ip6_sf_list *igmp6_mcf_get_next(struct seq_file *seq, struct ip6_sf_list *psf)
{
      struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);

      psf = psf->sf_next;
      while (!psf) {
            spin_unlock_bh(&state->im->mca_lock);
            state->im = state->im->next;
            while (!state->im) {
                  if (likely(state->idev != NULL)) {
                        read_unlock_bh(&state->idev->lock);
                        in6_dev_put(state->idev);
                  }
                  state->dev = next_net_device(state->dev);
                  if (!state->dev) {
                        state->idev = NULL;
                        goto out;
                  }
                  state->idev = in6_dev_get(state->dev);
                  if (!state->idev)
                        continue;
                  read_lock_bh(&state->idev->lock);
                  state->im = state->idev->mc_list;
            }
            if (!state->im)
                  break;
            spin_lock_bh(&state->im->mca_lock);
            psf = state->im->mca_sources;
      }
out:
      return psf;
}

static struct ip6_sf_list *igmp6_mcf_get_idx(struct seq_file *seq, loff_t pos)
{
      struct ip6_sf_list *psf = igmp6_mcf_get_first(seq);
      if (psf)
            while (pos && (psf = igmp6_mcf_get_next(seq, psf)) != NULL)
                  --pos;
      return pos ? NULL : psf;
}

static void *igmp6_mcf_seq_start(struct seq_file *seq, loff_t *pos)
{
      read_lock(&dev_base_lock);
      return *pos ? igmp6_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
}

static void *igmp6_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
      struct ip6_sf_list *psf;
      if (v == SEQ_START_TOKEN)
            psf = igmp6_mcf_get_first(seq);
      else
            psf = igmp6_mcf_get_next(seq, v);
      ++*pos;
      return psf;
}

static void igmp6_mcf_seq_stop(struct seq_file *seq, void *v)
{
      struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
      if (likely(state->im != NULL)) {
            spin_unlock_bh(&state->im->mca_lock);
            state->im = NULL;
      }
      if (likely(state->idev != NULL)) {
            read_unlock_bh(&state->idev->lock);
            in6_dev_put(state->idev);
            state->idev = NULL;
      }
      state->dev = NULL;
      read_unlock(&dev_base_lock);
}

static int igmp6_mcf_seq_show(struct seq_file *seq, void *v)
{
      struct ip6_sf_list *psf = (struct ip6_sf_list *)v;
      struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);

      if (v == SEQ_START_TOKEN) {
            seq_printf(seq,
                     "%3s %6s "
                     "%32s %32s %6s %6s\n", "Idx",
                     "Device", "Multicast Address",
                     "Source Address", "INC", "EXC");
      } else {
            seq_printf(seq,
                     "%3d %6.6s " NIP6_SEQFMT " " NIP6_SEQFMT " %6lu %6lu\n",
                     state->dev->ifindex, state->dev->name,
                     NIP6(state->im->mca_addr),
                     NIP6(psf->sf_addr),
                     psf->sf_count[MCAST_INCLUDE],
                     psf->sf_count[MCAST_EXCLUDE]);
      }
      return 0;
}

static const struct seq_operations igmp6_mcf_seq_ops = {
      .start      =     igmp6_mcf_seq_start,
      .next =     igmp6_mcf_seq_next,
      .stop =     igmp6_mcf_seq_stop,
      .show =     igmp6_mcf_seq_show,
};

static int igmp6_mcf_seq_open(struct inode *inode, struct file *file)
{
      return seq_open_private(file, &igmp6_mcf_seq_ops,
                  sizeof(struct igmp6_mcf_iter_state));
}

static const struct file_operations igmp6_mcf_seq_fops = {
      .owner            =     THIS_MODULE,
      .open       =     igmp6_mcf_seq_open,
      .read       =     seq_read,
      .llseek           =     seq_lseek,
      .release    =     seq_release_private,
};
#endif

int __init igmp6_init(struct net_proto_family *ops)
{
      struct ipv6_pinfo *np;
      struct sock *sk;
      int err;

      err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6, &igmp6_socket);
      if (err < 0) {
            printk(KERN_ERR
                   "Failed to initialize the IGMP6 control socket (err %d).\n",
                   err);
            igmp6_socket = NULL; /* For safety. */
            return err;
      }

      sk = igmp6_socket->sk;
      sk->sk_allocation = GFP_ATOMIC;
      sk->sk_prot->unhash(sk);

      np = inet6_sk(sk);
      np->hop_limit = 1;

#ifdef CONFIG_PROC_FS
      proc_net_fops_create(&init_net, "igmp6", S_IRUGO, &igmp6_mc_seq_fops);
      proc_net_fops_create(&init_net, "mcfilter6", S_IRUGO, &igmp6_mcf_seq_fops);
#endif

      return 0;
}

void igmp6_cleanup(void)
{
      sock_release(igmp6_socket);
      igmp6_socket = NULL; /* for safety */

#ifdef CONFIG_PROC_FS
      proc_net_remove(&init_net, "mcfilter6");
      proc_net_remove(&init_net, "igmp6");
#endif
}

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