Logo Search packages:      
Sourcecode: linux version File versions  Download package

igmp.c

/*
 *    Linux NET3: Internet Group Management Protocol  [IGMP]
 *
 *    This code implements the IGMP protocol as defined in RFC1112. There has
 *    been a further revision of this protocol since which is now supported.
 *
 *    If you have trouble with this module be careful what gcc you have used,
 *    the older version didn't come out right using gcc 2.5.8, the newer one
 *    seems to fall out with gcc 2.6.2.
 *
 *    Version: $Id: igmp.c,v 1.47 2002/02/01 22:01:03 davem Exp $
 *
 *    Authors:
 *          Alan Cox <Alan.Cox@linux.org>
 *
 *    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.
 *
 *    Fixes:
 *
 *          Alan Cox    :     Added lots of __inline__ to optimise
 *                            the memory usage of all the tiny little
 *                            functions.
 *          Alan Cox    :     Dumped the header building experiment.
 *          Alan Cox    :     Minor tweaks ready for multicast routing
 *                            and extended IGMP protocol.
 *          Alan Cox    :     Removed a load of inline directives. Gcc 2.5.8
 *                            writes utterly bogus code otherwise (sigh)
 *                            fixed IGMP loopback to behave in the manner
 *                            desired by mrouted, fixed the fact it has been
 *                            broken since 1.3.6 and cleaned up a few minor
 *                            points.
 *
 *          Chih-Jen Chang    :     Tried to revise IGMP to Version 2
 *          Tsu-Sheng Tsao          E-mail: chihjenc@scf.usc.edu and tsusheng@scf.usc.edu
 *                            The enhancements are mainly based on Steve Deering's
 *                            ipmulti-3.5 source code.
 *          Chih-Jen Chang    :     Added the igmp_get_mrouter_info and
 *          Tsu-Sheng Tsao          igmp_set_mrouter_info to keep track of
 *                            the mrouted version on that device.
 *          Chih-Jen Chang    :     Added the max_resp_time parameter to
 *          Tsu-Sheng Tsao          igmp_heard_query(). Using this parameter
 *                            to identify the multicast router version
 *                            and do what the IGMP version 2 specified.
 *          Chih-Jen Chang    :     Added a timer to revert to IGMP V2 router
 *          Tsu-Sheng Tsao          if the specified time expired.
 *          Alan Cox    :     Stop IGMP from 0.0.0.0 being accepted.
 *          Alan Cox    :     Use GFP_ATOMIC in the right places.
 *          Christian Daudt : igmp timer wasn't set for local group
 *                            memberships but was being deleted,
 *                            which caused a "del_timer() called
 *                            from %p with timer not initialized\n"
 *                            message (960131).
 *          Christian Daudt : removed del_timer from
 *                            igmp_timer_expire function (960205).
 *             Christian Daudt :       igmp_heard_report now only calls
 *                                     igmp_timer_expire if tm->running is
 *                                     true (960216).
 *          Malcolm Beattie : ttl comparison wrong in igmp_rcv made
 *                            igmp_heard_query never trigger. Expiry
 *                            miscalculation fixed in igmp_heard_query
 *                            and random() made to return unsigned to
 *                            prevent negative expiry times.
 *          Alexey Kuznetsov: Wrong group leaving behaviour, backport
 *                            fix from pending 2.1.x patches.
 *          Alan Cox:         Forget to enable FDDI support earlier.
 *          Alexey Kuznetsov: Fixed leaving groups on device down.
 *          Alexey Kuznetsov: Accordance to igmp-v2-06 draft.
 *          David L Stevens:  IGMPv3 support, with help from
 *                            Vinay Kulkarni
 */

#include <linux/module.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/inetdevice.h>
#include <linux/igmp.h>
#include <linux/if_arp.h>
#include <linux/rtnetlink.h>
#include <linux/times.h>

#include <net/net_namespace.h>
#include <net/arp.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/route.h>
#include <net/sock.h>
#include <net/checksum.h>
#include <linux/netfilter_ipv4.h>
#ifdef CONFIG_IP_MROUTE
#include <linux/mroute.h>
#endif
#ifdef CONFIG_PROC_FS
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#endif

#define IP_MAX_MEMBERSHIPS    20
#define IP_MAX_MSF            10

#ifdef CONFIG_IP_MULTICAST
/* Parameter names and values are taken from igmp-v2-06 draft */

#define IGMP_V1_Router_Present_Timeout          (400*HZ)
#define IGMP_V2_Router_Present_Timeout          (400*HZ)
#define IGMP_Unsolicited_Report_Interval  (10*HZ)
#define IGMP_Query_Response_Interval            (10*HZ)
#define IGMP_Unsolicited_Report_Count           2


#define IGMP_Initial_Report_Delay         (1)

/* IGMP_Initial_Report_Delay is not from IGMP specs!
 * IGMP specs require to report membership immediately after
 * joining a group, but we delay the first report by a
 * small interval. It seems more natural and still does not
 * contradict to specs provided this delay is small enough.
 */

#define IGMP_V1_SEEN(in_dev) \
      (IPV4_DEVCONF_ALL(FORCE_IGMP_VERSION) == 1 || \
       IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 1 || \
       ((in_dev)->mr_v1_seen && \
        time_before(jiffies, (in_dev)->mr_v1_seen)))
#define IGMP_V2_SEEN(in_dev) \
      (IPV4_DEVCONF_ALL(FORCE_IGMP_VERSION) == 2 || \
       IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 2 || \
       ((in_dev)->mr_v2_seen && \
        time_before(jiffies, (in_dev)->mr_v2_seen)))

static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im);
static void igmpv3_del_delrec(struct in_device *in_dev, __be32 multiaddr);
static void igmpv3_clear_delrec(struct in_device *in_dev);
static int sf_setstate(struct ip_mc_list *pmc);
static void sf_markstate(struct ip_mc_list *pmc);
#endif
static void ip_mc_clear_src(struct ip_mc_list *pmc);
static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
                   int sfcount, __be32 *psfsrc, int delta);

static void ip_ma_put(struct ip_mc_list *im)
{
      if (atomic_dec_and_test(&im->refcnt)) {
            in_dev_put(im->interface);
            kfree(im);
      }
}

#ifdef CONFIG_IP_MULTICAST

/*
 *    Timer management
 */

static __inline__ void igmp_stop_timer(struct ip_mc_list *im)
{
      spin_lock_bh(&im->lock);
      if (del_timer(&im->timer))
            atomic_dec(&im->refcnt);
      im->tm_running=0;
      im->reporter = 0;
      im->unsolicit_count = 0;
      spin_unlock_bh(&im->lock);
}

/* It must be called with locked im->lock */
static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
{
      int tv=net_random() % max_delay;

      im->tm_running=1;
      if (!mod_timer(&im->timer, jiffies+tv+2))
            atomic_inc(&im->refcnt);
}

static void igmp_gq_start_timer(struct in_device *in_dev)
{
      int tv = net_random() % in_dev->mr_maxdelay;

      in_dev->mr_gq_running = 1;
      if (!mod_timer(&in_dev->mr_gq_timer, jiffies+tv+2))
            in_dev_hold(in_dev);
}

static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
{
      int tv = net_random() % delay;

      if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
            in_dev_hold(in_dev);
}

static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
{
      spin_lock_bh(&im->lock);
      im->unsolicit_count = 0;
      if (del_timer(&im->timer)) {
            if ((long)(im->timer.expires-jiffies) < max_delay) {
                  add_timer(&im->timer);
                  im->tm_running=1;
                  spin_unlock_bh(&im->lock);
                  return;
            }
            atomic_dec(&im->refcnt);
      }
      igmp_start_timer(im, max_delay);
      spin_unlock_bh(&im->lock);
}


/*
 *    Send an IGMP report.
 */

#define IGMP_SIZE (sizeof(struct igmphdr)+sizeof(struct iphdr)+4)


static int is_in(struct ip_mc_list *pmc, struct ip_sf_list *psf, int type,
      int gdeleted, int sdeleted)
{
      switch (type) {
      case IGMPV3_MODE_IS_INCLUDE:
      case IGMPV3_MODE_IS_EXCLUDE:
            if (gdeleted || sdeleted)
                  return 0;
            if (!(pmc->gsquery && !psf->sf_gsresp)) {
                  if (pmc->sfmode == MCAST_INCLUDE)
                        return 1;
                  /* don't include if this source is excluded
                   * in all filters
                   */
                  if (psf->sf_count[MCAST_INCLUDE])
                        return type == IGMPV3_MODE_IS_INCLUDE;
                  return pmc->sfcount[MCAST_EXCLUDE] ==
                        psf->sf_count[MCAST_EXCLUDE];
            }
            return 0;
      case IGMPV3_CHANGE_TO_INCLUDE:
            if (gdeleted || sdeleted)
                  return 0;
            return psf->sf_count[MCAST_INCLUDE] != 0;
      case IGMPV3_CHANGE_TO_EXCLUDE:
            if (gdeleted || sdeleted)
                  return 0;
            if (pmc->sfcount[MCAST_EXCLUDE] == 0 ||
                psf->sf_count[MCAST_INCLUDE])
                  return 0;
            return pmc->sfcount[MCAST_EXCLUDE] ==
                  psf->sf_count[MCAST_EXCLUDE];
      case IGMPV3_ALLOW_NEW_SOURCES:
            if (gdeleted || !psf->sf_crcount)
                  return 0;
            return (pmc->sfmode == MCAST_INCLUDE) ^ sdeleted;
      case IGMPV3_BLOCK_OLD_SOURCES:
            if (pmc->sfmode == MCAST_INCLUDE)
                  return gdeleted || (psf->sf_crcount && sdeleted);
            return psf->sf_crcount && !gdeleted && !sdeleted;
      }
      return 0;
}

static int
igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted)
{
      struct ip_sf_list *psf;
      int scount = 0;

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

static struct sk_buff *igmpv3_newpack(struct net_device *dev, int size)
{
      struct sk_buff *skb;
      struct rtable *rt;
      struct iphdr *pip;
      struct igmpv3_report *pig;

      skb = alloc_skb(size + LL_RESERVED_SPACE(dev), GFP_ATOMIC);
      if (skb == NULL)
            return NULL;

      {
            struct flowi fl = { .oif = dev->ifindex,
                            .nl_u = { .ip4_u = {
                            .daddr = IGMPV3_ALL_MCR } },
                            .proto = IPPROTO_IGMP };
            if (ip_route_output_key(&rt, &fl)) {
                  kfree_skb(skb);
                  return NULL;
            }
      }
      if (rt->rt_src == 0) {
            kfree_skb(skb);
            ip_rt_put(rt);
            return NULL;
      }

      skb->dst = &rt->u.dst;
      skb->dev = dev;

      skb_reserve(skb, LL_RESERVED_SPACE(dev));

      skb_reset_network_header(skb);
      pip = ip_hdr(skb);
      skb_put(skb, sizeof(struct iphdr) + 4);

      pip->version  = 4;
      pip->ihl      = (sizeof(struct iphdr)+4)>>2;
      pip->tos      = 0xc0;
      pip->frag_off = htons(IP_DF);
      pip->ttl      = 1;
      pip->daddr    = rt->rt_dst;
      pip->saddr    = rt->rt_src;
      pip->protocol = IPPROTO_IGMP;
      pip->tot_len  = 0;      /* filled in later */
      ip_select_ident(pip, &rt->u.dst, NULL);
      ((u8*)&pip[1])[0] = IPOPT_RA;
      ((u8*)&pip[1])[1] = 4;
      ((u8*)&pip[1])[2] = 0;
      ((u8*)&pip[1])[3] = 0;

      skb->transport_header = skb->network_header + sizeof(struct iphdr) + 4;
      skb_put(skb, sizeof(*pig));
      pig = igmpv3_report_hdr(skb);
      pig->type = IGMPV3_HOST_MEMBERSHIP_REPORT;
      pig->resv1 = 0;
      pig->csum = 0;
      pig->resv2 = 0;
      pig->ngrec = 0;
      return skb;
}

static int igmpv3_sendpack(struct sk_buff *skb)
{
      struct iphdr *pip = ip_hdr(skb);
      struct igmphdr *pig = igmp_hdr(skb);
      const int iplen = skb->tail - skb->network_header;
      const int igmplen = skb->tail - skb->transport_header;

      pip->tot_len = htons(iplen);
      ip_send_check(pip);
      pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen);

      return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, skb->dev,
                   dst_output);
}

static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel)
{
      return sizeof(struct igmpv3_grec) + 4*igmp_scount(pmc,type,gdel,sdel);
}

static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
      int type, struct igmpv3_grec **ppgr)
{
      struct net_device *dev = pmc->interface->dev;
      struct igmpv3_report *pih;
      struct igmpv3_grec *pgr;

      if (!skb)
            skb = igmpv3_newpack(dev, dev->mtu);
      if (!skb)
            return NULL;
      pgr = (struct igmpv3_grec *)skb_put(skb, sizeof(struct igmpv3_grec));
      pgr->grec_type = type;
      pgr->grec_auxwords = 0;
      pgr->grec_nsrcs = 0;
      pgr->grec_mca = pmc->multiaddr;
      pih = igmpv3_report_hdr(skb);
      pih->ngrec = htons(ntohs(pih->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 ip_mc_list *pmc,
      int type, int gdeleted, int sdeleted)
{
      struct net_device *dev = pmc->interface->dev;
      struct igmpv3_report *pih;
      struct igmpv3_grec *pgr = NULL;
      struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list;
      int scount, stotal, first, isquery, truncate;

      if (pmc->multiaddr == IGMP_ALL_HOSTS)
            return skb;

      isquery = type == IGMPV3_MODE_IS_INCLUDE ||
              type == IGMPV3_MODE_IS_EXCLUDE;
      truncate = type == IGMPV3_MODE_IS_EXCLUDE ||
                type == IGMPV3_CHANGE_TO_EXCLUDE;

      stotal = scount = 0;

      psf_list = sdeleted ? &pmc->tomb : &pmc->sources;

      if (!*psf_list)
            goto empty_source;

      pih = skb ? igmpv3_report_hdr(skb) : NULL;

      /* EX and TO_EX get a fresh packet, if needed */
      if (truncate) {
            if (pih && pih->ngrec &&
                AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
                  if (skb)
                        igmpv3_sendpack(skb);
                  skb = igmpv3_newpack(dev, dev->mtu);
            }
      }
      first = 1;
      psf_prev = NULL;
      for (psf=*psf_list; psf; psf=psf_next) {
            __be32 *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(__be32) +
                first*sizeof(struct igmpv3_grec)) {
                  if (truncate && !first)
                        break;       /* truncate these */
                  if (pgr)
                        pgr->grec_nsrcs = htons(scount);
                  if (skb)
                        igmpv3_sendpack(skb);
                  skb = igmpv3_newpack(dev, dev->mtu);
                  first = 1;
                  scount = 0;
            }
            if (first) {
                  skb = add_grhead(skb, pmc, type, &pgr);
                  first = 0;
            }
            if (!skb)
                  return NULL;
            psrc = (__be32 *)skb_put(skb, sizeof(__be32));
            *psrc = psf->sf_inaddr;
            scount++; stotal++;
            if ((type == IGMPV3_ALLOW_NEW_SOURCES ||
                 type == IGMPV3_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 == IGMPV3_ALLOW_NEW_SOURCES ||
                type == IGMPV3_BLOCK_OLD_SOURCES)
                  return skb;
            if (pmc->crcount || isquery) {
                  /* make sure we have room for group header */
                  if (skb && AVAILABLE(skb)<sizeof(struct igmpv3_grec)) {
                        igmpv3_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->gsquery = 0; /* clear query state on report */
      return skb;
}

static int igmpv3_send_report(struct in_device *in_dev, struct ip_mc_list *pmc)
{
      struct sk_buff *skb = NULL;
      int type;

      if (!pmc) {
            read_lock(&in_dev->mc_list_lock);
            for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
                  if (pmc->multiaddr == IGMP_ALL_HOSTS)
                        continue;
                  spin_lock_bh(&pmc->lock);
                  if (pmc->sfcount[MCAST_EXCLUDE])
                        type = IGMPV3_MODE_IS_EXCLUDE;
                  else
                        type = IGMPV3_MODE_IS_INCLUDE;
                  skb = add_grec(skb, pmc, type, 0, 0);
                  spin_unlock_bh(&pmc->lock);
            }
            read_unlock(&in_dev->mc_list_lock);
      } else {
            spin_lock_bh(&pmc->lock);
            if (pmc->sfcount[MCAST_EXCLUDE])
                  type = IGMPV3_MODE_IS_EXCLUDE;
            else
                  type = IGMPV3_MODE_IS_INCLUDE;
            skb = add_grec(skb, pmc, type, 0, 0);
            spin_unlock_bh(&pmc->lock);
      }
      if (!skb)
            return 0;
      return igmpv3_sendpack(skb);
}

/*
 * remove zero-count source records from a source filter list
 */
static void igmpv3_clear_zeros(struct ip_sf_list **ppsf)
{
      struct ip_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 igmpv3_send_cr(struct in_device *in_dev)
{
      struct ip_mc_list *pmc, *pmc_prev, *pmc_next;
      struct sk_buff *skb = NULL;
      int type, dtype;

      read_lock(&in_dev->mc_list_lock);
      spin_lock_bh(&in_dev->mc_tomb_lock);

      /* deleted MCA's */
      pmc_prev = NULL;
      for (pmc=in_dev->mc_tomb; pmc; pmc=pmc_next) {
            pmc_next = pmc->next;
            if (pmc->sfmode == MCAST_INCLUDE) {
                  type = IGMPV3_BLOCK_OLD_SOURCES;
                  dtype = IGMPV3_BLOCK_OLD_SOURCES;
                  skb = add_grec(skb, pmc, type, 1, 0);
                  skb = add_grec(skb, pmc, dtype, 1, 1);
            }
            if (pmc->crcount) {
                  if (pmc->sfmode == MCAST_EXCLUDE) {
                        type = IGMPV3_CHANGE_TO_INCLUDE;
                        skb = add_grec(skb, pmc, type, 1, 0);
                  }
                  pmc->crcount--;
                  if (pmc->crcount == 0) {
                        igmpv3_clear_zeros(&pmc->tomb);
                        igmpv3_clear_zeros(&pmc->sources);
                  }
            }
            if (pmc->crcount == 0 && !pmc->tomb && !pmc->sources) {
                  if (pmc_prev)
                        pmc_prev->next = pmc_next;
                  else
                        in_dev->mc_tomb = pmc_next;
                  in_dev_put(pmc->interface);
                  kfree(pmc);
            } else
                  pmc_prev = pmc;
      }
      spin_unlock_bh(&in_dev->mc_tomb_lock);

      /* change recs */
      for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
            spin_lock_bh(&pmc->lock);
            if (pmc->sfcount[MCAST_EXCLUDE]) {
                  type = IGMPV3_BLOCK_OLD_SOURCES;
                  dtype = IGMPV3_ALLOW_NEW_SOURCES;
            } else {
                  type = IGMPV3_ALLOW_NEW_SOURCES;
                  dtype = IGMPV3_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->crcount) {
                  if (pmc->sfmode == MCAST_EXCLUDE)
                        type = IGMPV3_CHANGE_TO_EXCLUDE;
                  else
                        type = IGMPV3_CHANGE_TO_INCLUDE;
                  skb = add_grec(skb, pmc, type, 0, 0);
                  pmc->crcount--;
            }
            spin_unlock_bh(&pmc->lock);
      }
      read_unlock(&in_dev->mc_list_lock);

      if (!skb)
            return;
      (void) igmpv3_sendpack(skb);
}

static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
      int type)
{
      struct sk_buff *skb;
      struct iphdr *iph;
      struct igmphdr *ih;
      struct rtable *rt;
      struct net_device *dev = in_dev->dev;
      __be32      group = pmc ? pmc->multiaddr : 0;
      __be32      dst;

      if (type == IGMPV3_HOST_MEMBERSHIP_REPORT)
            return igmpv3_send_report(in_dev, pmc);
      else if (type == IGMP_HOST_LEAVE_MESSAGE)
            dst = IGMP_ALL_ROUTER;
      else
            dst = group;

      {
            struct flowi fl = { .oif = dev->ifindex,
                            .nl_u = { .ip4_u = { .daddr = dst } },
                            .proto = IPPROTO_IGMP };
            if (ip_route_output_key(&rt, &fl))
                  return -1;
      }
      if (rt->rt_src == 0) {
            ip_rt_put(rt);
            return -1;
      }

      skb=alloc_skb(IGMP_SIZE+LL_RESERVED_SPACE(dev), GFP_ATOMIC);
      if (skb == NULL) {
            ip_rt_put(rt);
            return -1;
      }

      skb->dst = &rt->u.dst;

      skb_reserve(skb, LL_RESERVED_SPACE(dev));

      skb_reset_network_header(skb);
      iph = ip_hdr(skb);
      skb_put(skb, sizeof(struct iphdr) + 4);

      iph->version  = 4;
      iph->ihl      = (sizeof(struct iphdr)+4)>>2;
      iph->tos      = 0xc0;
      iph->frag_off = htons(IP_DF);
      iph->ttl      = 1;
      iph->daddr    = dst;
      iph->saddr    = rt->rt_src;
      iph->protocol = IPPROTO_IGMP;
      iph->tot_len  = htons(IGMP_SIZE);
      ip_select_ident(iph, &rt->u.dst, NULL);
      ((u8*)&iph[1])[0] = IPOPT_RA;
      ((u8*)&iph[1])[1] = 4;
      ((u8*)&iph[1])[2] = 0;
      ((u8*)&iph[1])[3] = 0;
      ip_send_check(iph);

      ih = (struct igmphdr *)skb_put(skb, sizeof(struct igmphdr));
      ih->type=type;
      ih->code=0;
      ih->csum=0;
      ih->group=group;
      ih->csum=ip_compute_csum((void *)ih, sizeof(struct igmphdr));

      return NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, skb, NULL, rt->u.dst.dev,
                   dst_output);
}

static void igmp_gq_timer_expire(unsigned long data)
{
      struct in_device *in_dev = (struct in_device *)data;

      in_dev->mr_gq_running = 0;
      igmpv3_send_report(in_dev, NULL);
      __in_dev_put(in_dev);
}

static void igmp_ifc_timer_expire(unsigned long data)
{
      struct in_device *in_dev = (struct in_device *)data;

      igmpv3_send_cr(in_dev);
      if (in_dev->mr_ifc_count) {
            in_dev->mr_ifc_count--;
            igmp_ifc_start_timer(in_dev, IGMP_Unsolicited_Report_Interval);
      }
      __in_dev_put(in_dev);
}

static void igmp_ifc_event(struct in_device *in_dev)
{
      if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
            return;
      in_dev->mr_ifc_count = in_dev->mr_qrv ? in_dev->mr_qrv :
            IGMP_Unsolicited_Report_Count;
      igmp_ifc_start_timer(in_dev, 1);
}


static void igmp_timer_expire(unsigned long data)
{
      struct ip_mc_list *im=(struct ip_mc_list *)data;
      struct in_device *in_dev = im->interface;

      spin_lock(&im->lock);
      im->tm_running=0;

      if (im->unsolicit_count) {
            im->unsolicit_count--;
            igmp_start_timer(im, IGMP_Unsolicited_Report_Interval);
      }
      im->reporter = 1;
      spin_unlock(&im->lock);

      if (IGMP_V1_SEEN(in_dev))
            igmp_send_report(in_dev, im, IGMP_HOST_MEMBERSHIP_REPORT);
      else if (IGMP_V2_SEEN(in_dev))
            igmp_send_report(in_dev, im, IGMPV2_HOST_MEMBERSHIP_REPORT);
      else
            igmp_send_report(in_dev, im, IGMPV3_HOST_MEMBERSHIP_REPORT);

      ip_ma_put(im);
}

/* mark EXCLUDE-mode sources */
static int igmp_xmarksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
{
      struct ip_sf_list *psf;
      int i, scount;

      scount = 0;
      for (psf=pmc->sources; psf; psf=psf->sf_next) {
            if (scount == nsrcs)
                  break;
            for (i=0; i<nsrcs; i++) {
                  /* skip inactive filters */
                  if (pmc->sfcount[MCAST_INCLUDE] ||
                      pmc->sfcount[MCAST_EXCLUDE] !=
                      psf->sf_count[MCAST_EXCLUDE])
                        continue;
                  if (srcs[i] == psf->sf_inaddr) {
                        scount++;
                        break;
                  }
            }
      }
      pmc->gsquery = 0;
      if (scount == nsrcs)    /* all sources excluded */
            return 0;
      return 1;
}

static int igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
{
      struct ip_sf_list *psf;
      int i, scount;

      if (pmc->sfmode == MCAST_EXCLUDE)
            return igmp_xmarksources(pmc, nsrcs, srcs);

      /* mark INCLUDE-mode sources */
      scount = 0;
      for (psf=pmc->sources; psf; psf=psf->sf_next) {
            if (scount == nsrcs)
                  break;
            for (i=0; i<nsrcs; i++)
                  if (srcs[i] == psf->sf_inaddr) {
                        psf->sf_gsresp = 1;
                        scount++;
                        break;
                  }
      }
      if (!scount) {
            pmc->gsquery = 0;
            return 0;
      }
      pmc->gsquery = 1;
      return 1;
}

static void igmp_heard_report(struct in_device *in_dev, __be32 group)
{
      struct ip_mc_list *im;

      /* Timers are only set for non-local groups */

      if (group == IGMP_ALL_HOSTS)
            return;

      read_lock(&in_dev->mc_list_lock);
      for (im=in_dev->mc_list; im!=NULL; im=im->next) {
            if (im->multiaddr == group) {
                  igmp_stop_timer(im);
                  break;
            }
      }
      read_unlock(&in_dev->mc_list_lock);
}

static void igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
      int len)
{
      struct igmphdr          *ih = igmp_hdr(skb);
      struct igmpv3_query *ih3 = igmpv3_query_hdr(skb);
      struct ip_mc_list *im;
      __be32                  group = ih->group;
      int               max_delay;
      int               mark = 0;


      if (len == 8) {
            if (ih->code == 0) {
                  /* Alas, old v1 router presents here. */

                  max_delay = IGMP_Query_Response_Interval;
                  in_dev->mr_v1_seen = jiffies +
                        IGMP_V1_Router_Present_Timeout;
                  group = 0;
            } else {
                  /* v2 router present */
                  max_delay = ih->code*(HZ/IGMP_TIMER_SCALE);
                  in_dev->mr_v2_seen = jiffies +
                        IGMP_V2_Router_Present_Timeout;
            }
            /* cancel the interface change timer */
            in_dev->mr_ifc_count = 0;
            if (del_timer(&in_dev->mr_ifc_timer))
                  __in_dev_put(in_dev);
            /* clear deleted report items */
            igmpv3_clear_delrec(in_dev);
      } else if (len < 12) {
            return;     /* ignore bogus packet; freed by caller */
      } else { /* v3 */
            if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)))
                  return;

            ih3 = igmpv3_query_hdr(skb);
            if (ih3->nsrcs) {
                  if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)
                                 + ntohs(ih3->nsrcs)*sizeof(__be32)))
                        return;
                  ih3 = igmpv3_query_hdr(skb);
            }

            max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
            if (!max_delay)
                  max_delay = 1;    /* can't mod w/ 0 */
            in_dev->mr_maxdelay = max_delay;
            if (ih3->qrv)
                  in_dev->mr_qrv = ih3->qrv;
            if (!group) { /* general query */
                  if (ih3->nsrcs)
                        return;     /* no sources allowed */
                  igmp_gq_start_timer(in_dev);
                  return;
            }
            /* mark sources to include, if group & source-specific */
            mark = ih3->nsrcs != 0;
      }

      /*
       * - Start the timers in all of our membership records
       *   that the query applies to for the interface on
       *   which the query arrived excl. those that belong
       *   to a "local" group (224.0.0.X)
       * - For timers already running check if they need to
       *   be reset.
       * - Use the igmp->igmp_code field as the maximum
       *   delay possible
       */
      read_lock(&in_dev->mc_list_lock);
      for (im=in_dev->mc_list; im!=NULL; im=im->next) {
            int changed;

            if (group && group != im->multiaddr)
                  continue;
            if (im->multiaddr == IGMP_ALL_HOSTS)
                  continue;
            spin_lock_bh(&im->lock);
            if (im->tm_running)
                  im->gsquery = im->gsquery && mark;
            else
                  im->gsquery = mark;
            changed = !im->gsquery ||
                  igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs);
            spin_unlock_bh(&im->lock);
            if (changed)
                  igmp_mod_timer(im, max_delay);
      }
      read_unlock(&in_dev->mc_list_lock);
}

int igmp_rcv(struct sk_buff *skb)
{
      /* This basically follows the spec line by line -- see RFC1112 */
      struct igmphdr *ih;
      struct in_device *in_dev = in_dev_get(skb->dev);
      int len = skb->len;

      if (in_dev==NULL) {
            kfree_skb(skb);
            return 0;
      }

      if (!pskb_may_pull(skb, sizeof(struct igmphdr)))
            goto drop;

      switch (skb->ip_summed) {
      case CHECKSUM_COMPLETE:
            if (!csum_fold(skb->csum))
                  break;
            /* fall through */
      case CHECKSUM_NONE:
            skb->csum = 0;
            if (__skb_checksum_complete(skb))
                  goto drop;
      }

      ih = igmp_hdr(skb);
      switch (ih->type) {
      case IGMP_HOST_MEMBERSHIP_QUERY:
            igmp_heard_query(in_dev, skb, len);
            break;
      case IGMP_HOST_MEMBERSHIP_REPORT:
      case IGMPV2_HOST_MEMBERSHIP_REPORT:
      case IGMPV3_HOST_MEMBERSHIP_REPORT:
            /* Is it our report looped back? */
            if (((struct rtable*)skb->dst)->fl.iif == 0)
                  break;
            /* don't rely on MC router hearing unicast reports */
            if (skb->pkt_type == PACKET_MULTICAST ||
                skb->pkt_type == PACKET_BROADCAST)
                  igmp_heard_report(in_dev, ih->group);
            break;
      case IGMP_PIM:
#ifdef CONFIG_IP_PIMSM_V1
            in_dev_put(in_dev);
            return pim_rcv_v1(skb);
#endif
      case IGMP_DVMRP:
      case IGMP_TRACE:
      case IGMP_HOST_LEAVE_MESSAGE:
      case IGMP_MTRACE:
      case IGMP_MTRACE_RESP:
            break;
      default:
            break;
      }

drop:
      in_dev_put(in_dev);
      kfree_skb(skb);
      return 0;
}

#endif


/*
 *    Add a filter to a device
 */

static void ip_mc_filter_add(struct in_device *in_dev, __be32 addr)
{
      char buf[MAX_ADDR_LEN];
      struct net_device *dev = in_dev->dev;

      /* Checking for IFF_MULTICAST here is WRONG-WRONG-WRONG.
         We will get multicast token leakage, when IFF_MULTICAST
         is changed. This check should be done in dev->set_multicast_list
         routine. Something sort of:
         if (dev->mc_list && dev->flags&IFF_MULTICAST) { do it; }
         --ANK
         */
      if (arp_mc_map(addr, buf, dev, 0) == 0)
            dev_mc_add(dev,buf,dev->addr_len,0);
}

/*
 *    Remove a filter from a device
 */

static void ip_mc_filter_del(struct in_device *in_dev, __be32 addr)
{
      char buf[MAX_ADDR_LEN];
      struct net_device *dev = in_dev->dev;

      if (arp_mc_map(addr, buf, dev, 0) == 0)
            dev_mc_delete(dev,buf,dev->addr_len,0);
}

#ifdef CONFIG_IP_MULTICAST
/*
 * deleted ip_mc_list manipulation
 */
static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im)
{
      struct ip_mc_list *pmc;

      /* this is an "ip_mc_list" 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_KERNEL);
      if (!pmc)
            return;
      spin_lock_bh(&im->lock);
      pmc->interface = im->interface;
      in_dev_hold(in_dev);
      pmc->multiaddr = im->multiaddr;
      pmc->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
            IGMP_Unsolicited_Report_Count;
      pmc->sfmode = im->sfmode;
      if (pmc->sfmode == MCAST_INCLUDE) {
            struct ip_sf_list *psf;

            pmc->tomb = im->tomb;
            pmc->sources = im->sources;
            im->tomb = im->sources = NULL;
            for (psf=pmc->sources; psf; psf=psf->sf_next)
                  psf->sf_crcount = pmc->crcount;
      }
      spin_unlock_bh(&im->lock);

      spin_lock_bh(&in_dev->mc_tomb_lock);
      pmc->next = in_dev->mc_tomb;
      in_dev->mc_tomb = pmc;
      spin_unlock_bh(&in_dev->mc_tomb_lock);
}

static void igmpv3_del_delrec(struct in_device *in_dev, __be32 multiaddr)
{
      struct ip_mc_list *pmc, *pmc_prev;
      struct ip_sf_list *psf, *psf_next;

      spin_lock_bh(&in_dev->mc_tomb_lock);
      pmc_prev = NULL;
      for (pmc=in_dev->mc_tomb; pmc; pmc=pmc->next) {
            if (pmc->multiaddr == multiaddr)
                  break;
            pmc_prev = pmc;
      }
      if (pmc) {
            if (pmc_prev)
                  pmc_prev->next = pmc->next;
            else
                  in_dev->mc_tomb = pmc->next;
      }
      spin_unlock_bh(&in_dev->mc_tomb_lock);
      if (pmc) {
            for (psf=pmc->tomb; psf; psf=psf_next) {
                  psf_next = psf->sf_next;
                  kfree(psf);
            }
            in_dev_put(pmc->interface);
            kfree(pmc);
      }
}

static void igmpv3_clear_delrec(struct in_device *in_dev)
{
      struct ip_mc_list *pmc, *nextpmc;

      spin_lock_bh(&in_dev->mc_tomb_lock);
      pmc = in_dev->mc_tomb;
      in_dev->mc_tomb = NULL;
      spin_unlock_bh(&in_dev->mc_tomb_lock);

      for (; pmc; pmc = nextpmc) {
            nextpmc = pmc->next;
            ip_mc_clear_src(pmc);
            in_dev_put(pmc->interface);
            kfree(pmc);
      }
      /* clear dead sources, too */
      read_lock(&in_dev->mc_list_lock);
      for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
            struct ip_sf_list *psf, *psf_next;

            spin_lock_bh(&pmc->lock);
            psf = pmc->tomb;
            pmc->tomb = NULL;
            spin_unlock_bh(&pmc->lock);
            for (; psf; psf=psf_next) {
                  psf_next = psf->sf_next;
                  kfree(psf);
            }
      }
      read_unlock(&in_dev->mc_list_lock);
}
#endif

static void igmp_group_dropped(struct ip_mc_list *im)
{
      struct in_device *in_dev = im->interface;
#ifdef CONFIG_IP_MULTICAST
      int reporter;
#endif

      if (im->loaded) {
            im->loaded = 0;
            ip_mc_filter_del(in_dev, im->multiaddr);
      }

#ifdef CONFIG_IP_MULTICAST
      if (im->multiaddr == IGMP_ALL_HOSTS)
            return;

      reporter = im->reporter;
      igmp_stop_timer(im);

      if (!in_dev->dead) {
            if (IGMP_V1_SEEN(in_dev))
                  goto done;
            if (IGMP_V2_SEEN(in_dev)) {
                  if (reporter)
                        igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE);
                  goto done;
            }
            /* IGMPv3 */
            igmpv3_add_delrec(in_dev, im);

            igmp_ifc_event(in_dev);
      }
done:
#endif
      ip_mc_clear_src(im);
}

static void igmp_group_added(struct ip_mc_list *im)
{
      struct in_device *in_dev = im->interface;

      if (im->loaded == 0) {
            im->loaded = 1;
            ip_mc_filter_add(in_dev, im->multiaddr);
      }

#ifdef CONFIG_IP_MULTICAST
      if (im->multiaddr == IGMP_ALL_HOSTS)
            return;

      if (in_dev->dead)
            return;
      if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
            spin_lock_bh(&im->lock);
            igmp_start_timer(im, IGMP_Initial_Report_Delay);
            spin_unlock_bh(&im->lock);
            return;
      }
      /* else, v3 */

      im->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
            IGMP_Unsolicited_Report_Count;
      igmp_ifc_event(in_dev);
#endif
}


/*
 *    Multicast list managers
 */


/*
 *    A socket has joined a multicast group on device dev.
 */

void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
{
      struct ip_mc_list *im;

      ASSERT_RTNL();

      for (im=in_dev->mc_list; im; im=im->next) {
            if (im->multiaddr == addr) {
                  im->users++;
                  ip_mc_add_src(in_dev, &addr, MCAST_EXCLUDE, 0, NULL, 0);
                  goto out;
            }
      }

      im = kmalloc(sizeof(*im), GFP_KERNEL);
      if (!im)
            goto out;

      im->users=1;
      im->interface=in_dev;
      in_dev_hold(in_dev);
      im->multiaddr=addr;
      /* initial mode is (EX, empty) */
      im->sfmode = MCAST_EXCLUDE;
      im->sfcount[MCAST_INCLUDE] = 0;
      im->sfcount[MCAST_EXCLUDE] = 1;
      im->sources = NULL;
      im->tomb = NULL;
      im->crcount = 0;
      atomic_set(&im->refcnt, 1);
      spin_lock_init(&im->lock);
#ifdef CONFIG_IP_MULTICAST
      im->tm_running=0;
      init_timer(&im->timer);
      im->timer.data=(unsigned long)im;
      im->timer.function=&igmp_timer_expire;
      im->unsolicit_count = IGMP_Unsolicited_Report_Count;
      im->reporter = 0;
      im->gsquery = 0;
#endif
      im->loaded = 0;
      write_lock_bh(&in_dev->mc_list_lock);
      im->next=in_dev->mc_list;
      in_dev->mc_list=im;
      write_unlock_bh(&in_dev->mc_list_lock);
#ifdef CONFIG_IP_MULTICAST
      igmpv3_del_delrec(in_dev, im->multiaddr);
#endif
      igmp_group_added(im);
      if (!in_dev->dead)
            ip_rt_multicast_event(in_dev);
out:
      return;
}

/*
 *    Resend IGMP JOIN report; used for bonding.
 */
void ip_mc_rejoin_group(struct ip_mc_list *im)
{
#ifdef CONFIG_IP_MULTICAST
      struct in_device *in_dev = im->interface;

      if (im->multiaddr == IGMP_ALL_HOSTS)
            return;

      if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
            igmp_mod_timer(im, IGMP_Initial_Report_Delay);
            return;
      }
      /* else, v3 */
      im->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
            IGMP_Unsolicited_Report_Count;
      igmp_ifc_event(in_dev);
#endif
}

/*
 *    A socket has left a multicast group on device dev
 */

void ip_mc_dec_group(struct in_device *in_dev, __be32 addr)
{
      struct ip_mc_list *i, **ip;

      ASSERT_RTNL();

      for (ip=&in_dev->mc_list; (i=*ip)!=NULL; ip=&i->next) {
            if (i->multiaddr==addr) {
                  if (--i->users == 0) {
                        write_lock_bh(&in_dev->mc_list_lock);
                        *ip = i->next;
                        write_unlock_bh(&in_dev->mc_list_lock);
                        igmp_group_dropped(i);

                        if (!in_dev->dead)
                              ip_rt_multicast_event(in_dev);

                        ip_ma_put(i);
                        return;
                  }
                  break;
            }
      }
}

/* Device going down */

void ip_mc_down(struct in_device *in_dev)
{
      struct ip_mc_list *i;

      ASSERT_RTNL();

      for (i=in_dev->mc_list; i; i=i->next)
            igmp_group_dropped(i);

#ifdef CONFIG_IP_MULTICAST
      in_dev->mr_ifc_count = 0;
      if (del_timer(&in_dev->mr_ifc_timer))
            __in_dev_put(in_dev);
      in_dev->mr_gq_running = 0;
      if (del_timer(&in_dev->mr_gq_timer))
            __in_dev_put(in_dev);
      igmpv3_clear_delrec(in_dev);
#endif

      ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
}

void ip_mc_init_dev(struct in_device *in_dev)
{
      ASSERT_RTNL();

      in_dev->mc_tomb = NULL;
#ifdef CONFIG_IP_MULTICAST
      in_dev->mr_gq_running = 0;
      init_timer(&in_dev->mr_gq_timer);
      in_dev->mr_gq_timer.data=(unsigned long) in_dev;
      in_dev->mr_gq_timer.function=&igmp_gq_timer_expire;
      in_dev->mr_ifc_count = 0;
      init_timer(&in_dev->mr_ifc_timer);
      in_dev->mr_ifc_timer.data=(unsigned long) in_dev;
      in_dev->mr_ifc_timer.function=&igmp_ifc_timer_expire;
      in_dev->mr_qrv = IGMP_Unsolicited_Report_Count;
#endif

      rwlock_init(&in_dev->mc_list_lock);
      spin_lock_init(&in_dev->mc_tomb_lock);
}

/* Device going up */

void ip_mc_up(struct in_device *in_dev)
{
      struct ip_mc_list *i;

      ASSERT_RTNL();

      ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);

      for (i=in_dev->mc_list; i; i=i->next)
            igmp_group_added(i);
}

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

void ip_mc_destroy_dev(struct in_device *in_dev)
{
      struct ip_mc_list *i;

      ASSERT_RTNL();

      /* Deactivate timers */
      ip_mc_down(in_dev);

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

            igmp_group_dropped(i);
            ip_ma_put(i);

            write_lock_bh(&in_dev->mc_list_lock);
      }
      write_unlock_bh(&in_dev->mc_list_lock);
}

static struct in_device * ip_mc_find_dev(struct ip_mreqn *imr)
{
      struct flowi fl = { .nl_u = { .ip4_u =
                              { .daddr = imr->imr_multiaddr.s_addr } } };
      struct rtable *rt;
      struct net_device *dev = NULL;
      struct in_device *idev = NULL;

      if (imr->imr_ifindex) {
            idev = inetdev_by_index(imr->imr_ifindex);
            if (idev)
                  __in_dev_put(idev);
            return idev;
      }
      if (imr->imr_address.s_addr) {
            dev = ip_dev_find(imr->imr_address.s_addr);
            if (!dev)
                  return NULL;
            dev_put(dev);
      }

      if (!dev && !ip_route_output_key(&rt, &fl)) {
            dev = rt->u.dst.dev;
            ip_rt_put(rt);
      }
      if (dev) {
            imr->imr_ifindex = dev->ifindex;
            idev = __in_dev_get_rtnl(dev);
      }
      return idev;
}

/*
 *    Join a socket to a group
 */
int sysctl_igmp_max_memberships __read_mostly = IP_MAX_MEMBERSHIPS;
int sysctl_igmp_max_msf __read_mostly = IP_MAX_MSF;


static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
      __be32 *psfsrc)
{
      struct ip_sf_list *psf, *psf_prev;
      int rv = 0;

      psf_prev = NULL;
      for (psf=pmc->sources; psf; psf=psf->sf_next) {
            if (psf->sf_inaddr == *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[sfmode] == 0) {
            ip_rt_multicast_event(pmc->interface);
      }
      if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
#ifdef CONFIG_IP_MULTICAST
            struct in_device *in_dev = pmc->interface;
#endif

            /* no more filters for this source */
            if (psf_prev)
                  psf_prev->sf_next = psf->sf_next;
            else
                  pmc->sources = psf->sf_next;
#ifdef CONFIG_IP_MULTICAST
            if (psf->sf_oldin &&
                !IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
                  psf->sf_crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
                        IGMP_Unsolicited_Report_Count;
                  psf->sf_next = pmc->tomb;
                  pmc->tomb = psf;
                  rv = 1;
            } else
#endif
                  kfree(psf);
      }
      return rv;
}

#ifndef CONFIG_IP_MULTICAST
#define igmp_ifc_event(x)     do { } while (0)
#endif

static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
                   int sfcount, __be32 *psfsrc, int delta)
{
      struct ip_mc_list *pmc;
      int   changerec = 0;
      int   i, err;

      if (!in_dev)
            return -ENODEV;
      read_lock(&in_dev->mc_list_lock);
      for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
            if (*pmca == pmc->multiaddr)
                  break;
      }
      if (!pmc) {
            /* MCA not found?? bug */
            read_unlock(&in_dev->mc_list_lock);
            return -ESRCH;
      }
      spin_lock_bh(&pmc->lock);
      read_unlock(&in_dev->mc_list_lock);
#ifdef CONFIG_IP_MULTICAST
      sf_markstate(pmc);
#endif
      if (!delta) {
            err = -EINVAL;
            if (!pmc->sfcount[sfmode])
                  goto out_unlock;
            pmc->sfcount[sfmode]--;
      }
      err = 0;
      for (i=0; i<sfcount; i++) {
            int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);

            changerec |= rv > 0;
            if (!err && rv < 0)
                  err = rv;
      }
      if (pmc->sfmode == MCAST_EXCLUDE &&
          pmc->sfcount[MCAST_EXCLUDE] == 0 &&
          pmc->sfcount[MCAST_INCLUDE]) {
#ifdef CONFIG_IP_MULTICAST
            struct ip_sf_list *psf;
#endif

            /* filter mode change */
            pmc->sfmode = MCAST_INCLUDE;
#ifdef CONFIG_IP_MULTICAST
            pmc->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
                  IGMP_Unsolicited_Report_Count;
            in_dev->mr_ifc_count = pmc->crcount;
            for (psf=pmc->sources; psf; psf = psf->sf_next)
                  psf->sf_crcount = 0;
            igmp_ifc_event(pmc->interface);
      } else if (sf_setstate(pmc) || changerec) {
            igmp_ifc_event(pmc->interface);
#endif
      }
out_unlock:
      spin_unlock_bh(&pmc->lock);
      return err;
}

/*
 * Add multicast single-source filter to the interface list
 */
static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
      __be32 *psfsrc, int delta)
{
      struct ip_sf_list *psf, *psf_prev;

      psf_prev = NULL;
      for (psf=pmc->sources; psf; psf=psf->sf_next) {
            if (psf->sf_inaddr == *psfsrc)
                  break;
            psf_prev = psf;
      }
      if (!psf) {
            psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
            if (!psf)
                  return -ENOBUFS;
            psf->sf_inaddr = *psfsrc;
            if (psf_prev) {
                  psf_prev->sf_next = psf;
            } else
                  pmc->sources = psf;
      }
      psf->sf_count[sfmode]++;
      if (psf->sf_count[sfmode] == 1) {
            ip_rt_multicast_event(pmc->interface);
      }
      return 0;
}

#ifdef CONFIG_IP_MULTICAST
static void sf_markstate(struct ip_mc_list *pmc)
{
      struct ip_sf_list *psf;
      int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];

      for (psf=pmc->sources; psf; psf=psf->sf_next)
            if (pmc->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 ip_mc_list *pmc)
{
      struct ip_sf_list *psf, *dpsf;
      int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
      int qrv = pmc->interface->mr_qrv;
      int new_in, rv;

      rv = 0;
      for (psf=pmc->sources; psf; psf=psf->sf_next) {
            if (pmc->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 ip_sf_list *prev = NULL;

                        for (dpsf=pmc->tomb; dpsf; dpsf=dpsf->sf_next) {
                              if (dpsf->sf_inaddr == psf->sf_inaddr)
                                    break;
                              prev = dpsf;
                        }
                        if (dpsf) {
                              if (prev)
                                    prev->sf_next = dpsf->sf_next;
                              else
                                    pmc->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->tomb; dpsf; dpsf=dpsf->sf_next)
                        if (dpsf->sf_inaddr == psf->sf_inaddr)
                              break;
                  if (!dpsf) {
                        dpsf = (struct ip_sf_list *)
                              kmalloc(sizeof(*dpsf), GFP_ATOMIC);
                        if (!dpsf)
                              continue;
                        *dpsf = *psf;
                        /* pmc->lock held by callers */
                        dpsf->sf_next = pmc->tomb;
                        pmc->tomb = dpsf;
                  }
                  dpsf->sf_crcount = qrv;
                  rv++;
            }
      }
      return rv;
}
#endif

/*
 * Add multicast source filter list to the interface list
 */
static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
                   int sfcount, __be32 *psfsrc, int delta)
{
      struct ip_mc_list *pmc;
      int   isexclude;
      int   i, err;

      if (!in_dev)
            return -ENODEV;
      read_lock(&in_dev->mc_list_lock);
      for (pmc=in_dev->mc_list; pmc; pmc=pmc->next) {
            if (*pmca == pmc->multiaddr)
                  break;
      }
      if (!pmc) {
            /* MCA not found?? bug */
            read_unlock(&in_dev->mc_list_lock);
            return -ESRCH;
      }
      spin_lock_bh(&pmc->lock);
      read_unlock(&in_dev->mc_list_lock);

#ifdef CONFIG_IP_MULTICAST
      sf_markstate(pmc);
#endif
      isexclude = pmc->sfmode == MCAST_EXCLUDE;
      if (!delta)
            pmc->sfcount[sfmode]++;
      err = 0;
      for (i=0; i<sfcount; i++) {
            err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i], delta);
            if (err)
                  break;
      }
      if (err) {
            int j;

            pmc->sfcount[sfmode]--;
            for (j=0; j<i; j++)
                  (void) ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
      } else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {
#ifdef CONFIG_IP_MULTICAST
            struct ip_sf_list *psf;
            in_dev = pmc->interface;
#endif

            /* filter mode change */
            if (pmc->sfcount[MCAST_EXCLUDE])
                  pmc->sfmode = MCAST_EXCLUDE;
            else if (pmc->sfcount[MCAST_INCLUDE])
                  pmc->sfmode = MCAST_INCLUDE;
#ifdef CONFIG_IP_MULTICAST
            /* else no filters; keep old mode for reports */

            pmc->crcount = in_dev->mr_qrv ? in_dev->mr_qrv :
                  IGMP_Unsolicited_Report_Count;
            in_dev->mr_ifc_count = pmc->crcount;
            for (psf=pmc->sources; psf; psf = psf->sf_next)
                  psf->sf_crcount = 0;
            igmp_ifc_event(in_dev);
      } else if (sf_setstate(pmc)) {
            igmp_ifc_event(in_dev);
#endif
      }
      spin_unlock_bh(&pmc->lock);
      return err;
}

static void ip_mc_clear_src(struct ip_mc_list *pmc)
{
      struct ip_sf_list *psf, *nextpsf;

      for (psf=pmc->tomb; psf; psf=nextpsf) {
            nextpsf = psf->sf_next;
            kfree(psf);
      }
      pmc->tomb = NULL;
      for (psf=pmc->sources; psf; psf=nextpsf) {
            nextpsf = psf->sf_next;
            kfree(psf);
      }
      pmc->sources = NULL;
      pmc->sfmode = MCAST_EXCLUDE;
      pmc->sfcount[MCAST_INCLUDE] = 0;
      pmc->sfcount[MCAST_EXCLUDE] = 1;
}


/*
 * Join a multicast group
 */
int ip_mc_join_group(struct sock *sk , struct ip_mreqn *imr)
{
      int err;
      __be32 addr = imr->imr_multiaddr.s_addr;
      struct ip_mc_socklist *iml=NULL, *i;
      struct in_device *in_dev;
      struct inet_sock *inet = inet_sk(sk);
      int ifindex;
      int count = 0;

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

      rtnl_lock();

      in_dev = ip_mc_find_dev(imr);

      if (!in_dev) {
            iml = NULL;
            err = -ENODEV;
            goto done;
      }

      err = -EADDRINUSE;
      ifindex = imr->imr_ifindex;
      for (i = inet->mc_list; i; i = i->next) {
            if (i->multi.imr_multiaddr.s_addr == addr &&
                i->multi.imr_ifindex == ifindex)
                  goto done;
            count++;
      }
      err = -ENOBUFS;
      if (count >= sysctl_igmp_max_memberships)
            goto done;
      iml = sock_kmalloc(sk,sizeof(*iml),GFP_KERNEL);
      if (iml == NULL)
            goto done;

      memcpy(&iml->multi, imr, sizeof(*imr));
      iml->next = inet->mc_list;
      iml->sflist = NULL;
      iml->sfmode = MCAST_EXCLUDE;
      inet->mc_list = iml;
      ip_mc_inc_group(in_dev, addr);
      err = 0;
done:
      rtnl_unlock();
      return err;
}

static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
                     struct in_device *in_dev)
{
      int err;

      if (iml->sflist == NULL) {
            /* any-source empty exclude case */
            return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
                  iml->sfmode, 0, NULL, 0);
      }
      err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
                  iml->sfmode, iml->sflist->sl_count,
                  iml->sflist->sl_addr, 0);
      sock_kfree_s(sk, iml->sflist, IP_SFLSIZE(iml->sflist->sl_max));
      iml->sflist = NULL;
      return err;
}

/*
 *    Ask a socket to leave a group.
 */

int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
{
      struct inet_sock *inet = inet_sk(sk);
      struct ip_mc_socklist *iml, **imlp;
      struct in_device *in_dev;
      __be32 group = imr->imr_multiaddr.s_addr;
      u32 ifindex;
      int ret = -EADDRNOTAVAIL;

      rtnl_lock();
      in_dev = ip_mc_find_dev(imr);
      ifindex = imr->imr_ifindex;
      for (imlp = &inet->mc_list; (iml = *imlp) != NULL; imlp = &iml->next) {
            if (iml->multi.imr_multiaddr.s_addr != group)
                  continue;
            if (ifindex) {
                  if (iml->multi.imr_ifindex != ifindex)
                        continue;
            } else if (imr->imr_address.s_addr && imr->imr_address.s_addr !=
                        iml->multi.imr_address.s_addr)
                  continue;

            (void) ip_mc_leave_src(sk, iml, in_dev);

            *imlp = iml->next;

            if (in_dev)
                  ip_mc_dec_group(in_dev, group);
            rtnl_unlock();
            sock_kfree_s(sk, iml, sizeof(*iml));
            return 0;
      }
      if (!in_dev)
            ret = -ENODEV;
      rtnl_unlock();
      return ret;
}

int ip_mc_source(int add, int omode, struct sock *sk, struct
      ip_mreq_source *mreqs, int ifindex)
{
      int err;
      struct ip_mreqn imr;
      __be32 addr = mreqs->imr_multiaddr;
      struct ip_mc_socklist *pmc;
      struct in_device *in_dev = NULL;
      struct inet_sock *inet = inet_sk(sk);
      struct ip_sf_socklist *psl;
      int leavegroup = 0;
      int i, j, rv;

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

      rtnl_lock();

      imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr;
      imr.imr_address.s_addr = mreqs->imr_interface;
      imr.imr_ifindex = ifindex;
      in_dev = ip_mc_find_dev(&imr);

      if (!in_dev) {
            err = -ENODEV;
            goto done;
      }
      err = -EADDRNOTAVAIL;

      for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
            if (pmc->multi.imr_multiaddr.s_addr == imr.imr_multiaddr.s_addr
                && pmc->multi.imr_ifindex == imr.imr_ifindex)
                  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 */
            ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0);
            ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0,
                  NULL, 0);
            pmc->sfmode = omode;
      }

      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], &mreqs->imr_sourceaddr,
                        sizeof(__be32));
                  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 */
            ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
                  &mreqs->imr_sourceaddr, 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_igmp_max_msf) {
            err = -ENOBUFS;
            goto done;
      }
      if (!psl || psl->sl_count == psl->sl_max) {
            struct ip_sf_socklist *newpsl;
            int count = IP_SFBLOCK;

            if (psl)
                  count += psl->sl_max;
            newpsl = sock_kmalloc(sk, IP_SFLSIZE(count), GFP_KERNEL);
            if (!newpsl) {
                  err = -ENOBUFS;
                  goto done;
            }
            newpsl->sl_max = count;
            newpsl->sl_count = count - IP_SFBLOCK;
            if (psl) {
                  for (i=0; i<psl->sl_count; i++)
                        newpsl->sl_addr[i] = psl->sl_addr[i];
                  sock_kfree_s(sk, psl, IP_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], &mreqs->imr_sourceaddr,
                  sizeof(__be32));
            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] = mreqs->imr_sourceaddr;
      psl->sl_count++;
      err = 0;
      /* update the interface list */
      ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
            &mreqs->imr_sourceaddr, 1);
done:
      rtnl_unlock();
      if (leavegroup)
            return ip_mc_leave_group(sk, &imr);
      return err;
}

int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
{
      int err = 0;
      struct ip_mreqn   imr;
      __be32 addr = msf->imsf_multiaddr;
      struct ip_mc_socklist *pmc;
      struct in_device *in_dev;
      struct inet_sock *inet = inet_sk(sk);
      struct ip_sf_socklist *newpsl, *psl;
      int leavegroup = 0;

      if (!MULTICAST(addr))
            return -EINVAL;
      if (msf->imsf_fmode != MCAST_INCLUDE &&
          msf->imsf_fmode != MCAST_EXCLUDE)
            return -EINVAL;

      rtnl_lock();

      imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
      imr.imr_address.s_addr = msf->imsf_interface;
      imr.imr_ifindex = ifindex;
      in_dev = ip_mc_find_dev(&imr);

      if (!in_dev) {
            err = -ENODEV;
            goto done;
      }

      /* special case - (INCLUDE, empty) == LEAVE_GROUP */
      if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) {
            leavegroup = 1;
            goto done;
      }

      for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
            if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
                pmc->multi.imr_ifindex == imr.imr_ifindex)
                  break;
      }
      if (!pmc) {       /* must have a prior join */
            err = -EINVAL;
            goto done;
      }
      if (msf->imsf_numsrc) {
            newpsl = sock_kmalloc(sk, IP_SFLSIZE(msf->imsf_numsrc),
                                             GFP_KERNEL);
            if (!newpsl) {
                  err = -ENOBUFS;
                  goto done;
            }
            newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc;
            memcpy(newpsl->sl_addr, msf->imsf_slist,
                  msf->imsf_numsrc * sizeof(msf->imsf_slist[0]));
            err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
                  msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
            if (err) {
                  sock_kfree_s(sk, newpsl, IP_SFLSIZE(newpsl->sl_max));
                  goto done;
            }
      } else {
            newpsl = NULL;
            (void) ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
                             msf->imsf_fmode, 0, NULL, 0);
      }
      psl = pmc->sflist;
      if (psl) {
            (void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
                  psl->sl_count, psl->sl_addr, 0);
            sock_kfree_s(sk, psl, IP_SFLSIZE(psl->sl_max));
      } else
            (void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
                  0, NULL, 0);
      pmc->sflist = newpsl;
      pmc->sfmode = msf->imsf_fmode;
      err = 0;
done:
      rtnl_unlock();
      if (leavegroup)
            err = ip_mc_leave_group(sk, &imr);
      return err;
}

int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
      struct ip_msfilter __user *optval, int __user *optlen)
{
      int err, len, count, copycount;
      struct ip_mreqn   imr;
      __be32 addr = msf->imsf_multiaddr;
      struct ip_mc_socklist *pmc;
      struct in_device *in_dev;
      struct inet_sock *inet = inet_sk(sk);
      struct ip_sf_socklist *psl;

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

      rtnl_lock();

      imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
      imr.imr_address.s_addr = msf->imsf_interface;
      imr.imr_ifindex = 0;
      in_dev = ip_mc_find_dev(&imr);

      if (!in_dev) {
            err = -ENODEV;
            goto done;
      }
      err = -EADDRNOTAVAIL;

      for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
            if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
                pmc->multi.imr_ifindex == imr.imr_ifindex)
                  break;
      }
      if (!pmc)         /* must have a prior join */
            goto done;
      msf->imsf_fmode = pmc->sfmode;
      psl = pmc->sflist;
      rtnl_unlock();
      if (!psl) {
            len = 0;
            count = 0;
      } else {
            count = psl->sl_count;
      }
      copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
      len = copycount * sizeof(psl->sl_addr[0]);
      msf->imsf_numsrc = count;
      if (put_user(IP_MSFILTER_SIZE(copycount), optlen) ||
          copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) {
            return -EFAULT;
      }
      if (len &&
          copy_to_user(&optval->imsf_slist[0], psl->sl_addr, len))
            return -EFAULT;
      return 0;
done:
      rtnl_unlock();
      return err;
}

int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
      struct group_filter __user *optval, int __user *optlen)
{
      int err, i, count, copycount;
      struct sockaddr_in *psin;
      __be32 addr;
      struct ip_mc_socklist *pmc;
      struct inet_sock *inet = inet_sk(sk);
      struct ip_sf_socklist *psl;

      psin = (struct sockaddr_in *)&gsf->gf_group;
      if (psin->sin_family != AF_INET)
            return -EINVAL;
      addr = psin->sin_addr.s_addr;
      if (!MULTICAST(addr))
            return -EINVAL;

      rtnl_lock();

      err = -EADDRNOTAVAIL;

      for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
            if (pmc->multi.imr_multiaddr.s_addr == addr &&
                pmc->multi.imr_ifindex == gsf->gf_interface)
                  break;
      }
      if (!pmc)         /* must have a prior join */
            goto done;
      gsf->gf_fmode = pmc->sfmode;
      psl = pmc->sflist;
      rtnl_unlock();
      count = psl ? psl->sl_count : 0;
      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;
      }
      for (i=0; i<copycount; i++) {
            struct sockaddr_storage ss;

            psin = (struct sockaddr_in *)&ss;
            memset(&ss, 0, sizeof(ss));
            psin->sin_family = AF_INET;
            psin->sin_addr.s_addr = psl->sl_addr[i];
            if (copy_to_user(&optval->gf_slist[i], &ss, sizeof(ss)))
                  return -EFAULT;
      }
      return 0;
done:
      rtnl_unlock();
      return err;
}

/*
 * check if a multicast source filter allows delivery for a given <src,dst,intf>
 */
int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr, int dif)
{
      struct inet_sock *inet = inet_sk(sk);
      struct ip_mc_socklist *pmc;
      struct ip_sf_socklist *psl;
      int i;

      if (!MULTICAST(loc_addr))
            return 1;

      for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
            if (pmc->multi.imr_multiaddr.s_addr == loc_addr &&
                pmc->multi.imr_ifindex == dif)
                  break;
      }
      if (!pmc)
            return 1;
      psl = pmc->sflist;
      if (!psl)
            return pmc->sfmode == MCAST_EXCLUDE;

      for (i=0; i<psl->sl_count; i++) {
            if (psl->sl_addr[i] == rmt_addr)
                  break;
      }
      if (pmc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
            return 0;
      if (pmc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
            return 0;
      return 1;
}

/*
 *    A socket is closing.
 */

void ip_mc_drop_socket(struct sock *sk)
{
      struct inet_sock *inet = inet_sk(sk);
      struct ip_mc_socklist *iml;

      if (inet->mc_list == NULL)
            return;

      rtnl_lock();
      while ((iml = inet->mc_list) != NULL) {
            struct in_device *in_dev;
            inet->mc_list = iml->next;

            in_dev = inetdev_by_index(iml->multi.imr_ifindex);
            (void) ip_mc_leave_src(sk, iml, in_dev);
            if (in_dev != NULL) {
                  ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
                  in_dev_put(in_dev);
            }
            sock_kfree_s(sk, iml, sizeof(*iml));
      }
      rtnl_unlock();
}

int ip_check_mc(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u16 proto)
{
      struct ip_mc_list *im;
      struct ip_sf_list *psf;
      int rv = 0;

      read_lock(&in_dev->mc_list_lock);
      for (im=in_dev->mc_list; im; im=im->next) {
            if (im->multiaddr == mc_addr)
                  break;
      }
      if (im && proto == IPPROTO_IGMP) {
            rv = 1;
      } else if (im) {
            if (src_addr) {
                  for (psf=im->sources; psf; psf=psf->sf_next) {
                        if (psf->sf_inaddr == src_addr)
                              break;
                  }
                  if (psf)
                        rv = psf->sf_count[MCAST_INCLUDE] ||
                              psf->sf_count[MCAST_EXCLUDE] !=
                              im->sfcount[MCAST_EXCLUDE];
                  else
                        rv = im->sfcount[MCAST_EXCLUDE] != 0;
            } else
                  rv = 1; /* unspecified source; tentatively allow */
      }
      read_unlock(&in_dev->mc_list_lock);
      return rv;
}

#if defined(CONFIG_PROC_FS)
struct igmp_mc_iter_state {
      struct net_device *dev;
      struct in_device *in_dev;
};

#define     igmp_mc_seq_private(seq)      ((struct igmp_mc_iter_state *)(seq)->private)

static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
{
      struct ip_mc_list *im = NULL;
      struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);

      state->in_dev = NULL;
      for_each_netdev(&init_net, state->dev) {
            struct in_device *in_dev;
            in_dev = in_dev_get(state->dev);
            if (!in_dev)
                  continue;
            read_lock(&in_dev->mc_list_lock);
            im = in_dev->mc_list;
            if (im) {
                  state->in_dev = in_dev;
                  break;
            }
            read_unlock(&in_dev->mc_list_lock);
            in_dev_put(in_dev);
      }
      return im;
}

static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_list *im)
{
      struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
      im = im->next;
      while (!im) {
            if (likely(state->in_dev != NULL)) {
                  read_unlock(&state->in_dev->mc_list_lock);
                  in_dev_put(state->in_dev);
            }
            state->dev = next_net_device(state->dev);
            if (!state->dev) {
                  state->in_dev = NULL;
                  break;
            }
            state->in_dev = in_dev_get(state->dev);
            if (!state->in_dev)
                  continue;
            read_lock(&state->in_dev->mc_list_lock);
            im = state->in_dev->mc_list;
      }
      return im;
}

static struct ip_mc_list *igmp_mc_get_idx(struct seq_file *seq, loff_t pos)
{
      struct ip_mc_list *im = igmp_mc_get_first(seq);
      if (im)
            while (pos && (im = igmp_mc_get_next(seq, im)) != NULL)
                  --pos;
      return pos ? NULL : im;
}

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

static void *igmp_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
      struct ip_mc_list *im;
      if (v == SEQ_START_TOKEN)
            im = igmp_mc_get_first(seq);
      else
            im = igmp_mc_get_next(seq, v);
      ++*pos;
      return im;
}

static void igmp_mc_seq_stop(struct seq_file *seq, void *v)
{
      struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
      if (likely(state->in_dev != NULL)) {
            read_unlock(&state->in_dev->mc_list_lock);
            in_dev_put(state->in_dev);
            state->in_dev = NULL;
      }
      state->dev = NULL;
      read_unlock(&dev_base_lock);
}

static int igmp_mc_seq_show(struct seq_file *seq, void *v)
{
      if (v == SEQ_START_TOKEN)
            seq_puts(seq,
                   "Idx\tDevice    : Count Querier\tGroup    Users Timer\tReporter\n");
      else {
            struct ip_mc_list *im = (struct ip_mc_list *)v;
            struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
            char   *querier;
#ifdef CONFIG_IP_MULTICAST
            querier = IGMP_V1_SEEN(state->in_dev) ? "V1" :
                    IGMP_V2_SEEN(state->in_dev) ? "V2" :
                    "V3";
#else
            querier = "NONE";
#endif

            if (state->in_dev->mc_list == im) {
                  seq_printf(seq, "%d\t%-10s: %5d %7s\n",
                           state->dev->ifindex, state->dev->name, state->dev->mc_count, querier);
            }

            seq_printf(seq,
                     "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n",
                     im->multiaddr, im->users,
                     im->tm_running, im->tm_running ?
                     jiffies_to_clock_t(im->timer.expires-jiffies) : 0,
                     im->reporter);
      }
      return 0;
}

static const struct seq_operations igmp_mc_seq_ops = {
      .start      =     igmp_mc_seq_start,
      .next =     igmp_mc_seq_next,
      .stop =     igmp_mc_seq_stop,
      .show =     igmp_mc_seq_show,
};

static int igmp_mc_seq_open(struct inode *inode, struct file *file)
{
      return seq_open_private(file, &igmp_mc_seq_ops,
                  sizeof(struct igmp_mc_iter_state));
}

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

struct igmp_mcf_iter_state {
      struct net_device *dev;
      struct in_device *idev;
      struct ip_mc_list *im;
};

#define igmp_mcf_seq_private(seq)   ((struct igmp_mcf_iter_state *)(seq)->private)

static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
{
      struct ip_sf_list *psf = NULL;
      struct ip_mc_list *im = NULL;
      struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);

      state->idev = NULL;
      state->im = NULL;
      for_each_netdev(&init_net, state->dev) {
            struct in_device *idev;
            idev = in_dev_get(state->dev);
            if (unlikely(idev == NULL))
                  continue;
            read_lock(&idev->mc_list_lock);
            im = idev->mc_list;
            if (likely(im != NULL)) {
                  spin_lock_bh(&im->lock);
                  psf = im->sources;
                  if (likely(psf != NULL)) {
                        state->im = im;
                        state->idev = idev;
                        break;
                  }
                  spin_unlock_bh(&im->lock);
            }
            read_unlock(&idev->mc_list_lock);
            in_dev_put(idev);
      }
      return psf;
}

static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_list *psf)
{
      struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);

      psf = psf->sf_next;
      while (!psf) {
            spin_unlock_bh(&state->im->lock);
            state->im = state->im->next;
            while (!state->im) {
                  if (likely(state->idev != NULL)) {
                        read_unlock(&state->idev->mc_list_lock);
                        in_dev_put(state->idev);
                  }
                  state->dev = next_net_device(state->dev);
                  if (!state->dev) {
                        state->idev = NULL;
                        goto out;
                  }
                  state->idev = in_dev_get(state->dev);
                  if (!state->idev)
                        continue;
                  read_lock(&state->idev->mc_list_lock);
                  state->im = state->idev->mc_list;
            }
            if (!state->im)
                  break;
            spin_lock_bh(&state->im->lock);
            psf = state->im->sources;
      }
out:
      return psf;
}

static struct ip_sf_list *igmp_mcf_get_idx(struct seq_file *seq, loff_t pos)
{
      struct ip_sf_list *psf = igmp_mcf_get_first(seq);
      if (psf)
            while (pos && (psf = igmp_mcf_get_next(seq, psf)) != NULL)
                  --pos;
      return pos ? NULL : psf;
}

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

static void *igmp_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
      struct ip_sf_list *psf;
      if (v == SEQ_START_TOKEN)
            psf = igmp_mcf_get_first(seq);
      else
            psf = igmp_mcf_get_next(seq, v);
      ++*pos;
      return psf;
}

static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
{
      struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
      if (likely(state->im != NULL)) {
            spin_unlock_bh(&state->im->lock);
            state->im = NULL;
      }
      if (likely(state->idev != NULL)) {
            read_unlock(&state->idev->mc_list_lock);
            in_dev_put(state->idev);
            state->idev = NULL;
      }
      state->dev = NULL;
      read_unlock(&dev_base_lock);
}

static int igmp_mcf_seq_show(struct seq_file *seq, void *v)
{
      struct ip_sf_list *psf = (struct ip_sf_list *)v;
      struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);

      if (v == SEQ_START_TOKEN) {
            seq_printf(seq,
                     "%3s %6s "
                     "%10s %10s %6s %6s\n", "Idx",
                     "Device", "MCA",
                     "SRC", "INC", "EXC");
      } else {
            seq_printf(seq,
                     "%3d %6.6s 0x%08x "
                     "0x%08x %6lu %6lu\n",
                     state->dev->ifindex, state->dev->name,
                     ntohl(state->im->multiaddr),
                     ntohl(psf->sf_inaddr),
                     psf->sf_count[MCAST_INCLUDE],
                     psf->sf_count[MCAST_EXCLUDE]);
      }
      return 0;
}

static const struct seq_operations igmp_mcf_seq_ops = {
      .start      =     igmp_mcf_seq_start,
      .next =     igmp_mcf_seq_next,
      .stop =     igmp_mcf_seq_stop,
      .show =     igmp_mcf_seq_show,
};

static int igmp_mcf_seq_open(struct inode *inode, struct file *file)
{
      return seq_open_private(file, &igmp_mcf_seq_ops,
                  sizeof(struct igmp_mcf_iter_state));
}

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

int __init igmp_mc_proc_init(void)
{
      proc_net_fops_create(&init_net, "igmp", S_IRUGO, &igmp_mc_seq_fops);
      proc_net_fops_create(&init_net, "mcfilter", S_IRUGO, &igmp_mcf_seq_fops);
      return 0;
}
#endif

EXPORT_SYMBOL(ip_mc_dec_group);
EXPORT_SYMBOL(ip_mc_inc_group);
EXPORT_SYMBOL(ip_mc_join_group);
EXPORT_SYMBOL(ip_mc_rejoin_group);

Generated by  Doxygen 1.6.0   Back to index