plugin_transport_udp_broadcasting.c File Reference

Neighbour discovery with UDP. More...

#include "platform.h"
#include "plugin_transport_udp.h"
#include "gnunet_hello_lib.h"
#include "gnunet_util_lib.h"
#include "gnunet_fragmentation_lib.h"
#include "gnunet_protocols.h"
#include "gnunet_resolver_service.h"
#include "gnunet_signatures.h"
#include "gnunet_constants.h"
#include "gnunet_statistics_service.h"
#include "gnunet_transport_service.h"
#include "gnunet_transport_plugin.h"
#include "transport.h"

Include dependency graph for plugin_transport_udp_broadcasting.c:

Go to the source code of this file.

Data Structures
struct	UDP_Beacon_Message
struct	BroadcastAddress
struct	MstContext
	Client-specific context for broadcast_mst_cb(). More...

Macros
#define	LOG(kind, ...)   GNUNET_log_from (kind, "transport-udp", __VA_ARGS__)

Functions
static int	broadcast_mst_cb (void *cls, const struct GNUNET_MessageHeader *message)
	Parse broadcast message received. More...
void	udp_broadcast_receive (struct Plugin *plugin, const char *buf, ssize_t size, const union UdpAddress *udp_addr, size_t udp_addr_len, enum GNUNET_NetworkType network_type)
	We received a broadcast message. More...
static unsigned int	prepare_beacon (struct Plugin *plugin, struct UDP_Beacon_Message *msg)
static void	udp_ipv4_broadcast_send (void *cls)
static void	udp_ipv6_broadcast_send (void *cls)
static int	iface_proc (void *cls, const char *name, int isDefault, const struct sockaddr *addr, const struct sockaddr *broadcast_addr, const struct sockaddr *netmask, socklen_t addrlen)
	Callback function invoked for each interface found. More...
void	setup_broadcast (struct Plugin *plugin, struct sockaddr_in6 *server_addrv6, struct sockaddr_in *server_addrv4)
	Setup broadcasting subsystem. More...
void	stop_broadcast (struct Plugin *plugin)
	Stop broadcasting subsystem. More...

Detailed Description

Neighbour discovery with UDP.

Author

Christian Grothoff

Matthias Wachs

Definition in file plugin_transport_udp_broadcasting.c.

Macro Definition Documentation

LOG

#define LOG	(		kind,
			...
	)		GNUNET_log_from (kind, "transport-udp", __VA_ARGS__)

Definition at line 41 of file plugin_transport_udp_broadcasting.c.

Function Documentation

broadcast_mst_cb()

static int broadcast_mst_cb ( void *  cls, const struct GNUNET_MessageHeader *  message  )

static

Parse broadcast message received.

Parameters

cls	the struct Plugin
client	the struct MstContext with sender address
message	the message we received

Returns

GNUNET_OK (always)

Definition at line 136 of file plugin_transport_udp_broadcasting.c.

{
  struct MstContext *mc = cls;
  struct Plugin *plugin = mc->plugin;
  struct GNUNET_HELLO_Address *address;
  const struct GNUNET_MessageHeader *hello;
  const struct UDP_Beacon_Message *msg;
 
  msg = (const struct UDP_Beacon_Message *) message;
 
  if (GNUNET_MESSAGE_TYPE_TRANSPORT_BROADCAST_BEACON !=
      ntohs (msg->header.type))
    return GNUNET_OK;
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Received beacon with %u bytes from peer `%s' via address `%s'\n",
       ntohs (msg->header.size),
       GNUNET_i2s (&msg->sender),
       udp_address_to_string (NULL,
                              mc->udp_addr,
                              mc->udp_addr_len));
  hello = (struct GNUNET_MessageHeader *) &msg[1];
  address = GNUNET_HELLO_address_allocate (&msg->sender,
                                           PLUGIN_NAME,
                                           mc->udp_addr,
                                           mc->udp_addr_len,
                                           GNUNET_HELLO_ADDRESS_INFO_NONE);
  plugin->env->receive (plugin->env->cls,
                        address,
                        NULL,
                        hello);
  GNUNET_HELLO_address_free (address);
  GNUNET_STATISTICS_update (plugin->env->stats,
                            _ ("# Multicast HELLO beacons received via UDP"),
                            1, GNUNET_NO);
  return GNUNET_OK;
}

References _, address, GNUNET_ERROR_TYPE_DEBUG, GNUNET_HELLO_address_allocate(), GNUNET_HELLO_address_free, GNUNET_HELLO_ADDRESS_INFO_NONE, GNUNET_i2s(), GNUNET_MESSAGE_TYPE_TRANSPORT_BROADCAST_BEACON, GNUNET_NO, GNUNET_OK, GNUNET_STATISTICS_update(), LOG, mc, msg, plugin, PLUGIN_NAME, GNUNET_MessageHeader::size, GNUNET_MessageHeader::type, and udp_address_to_string().

Referenced by udp_broadcast_receive().

Here is the call graph for this function:

Here is the caller graph for this function:

udp_broadcast_receive()

void udp_broadcast_receive	(	struct Plugin *	plugin,
		const char *	buf,
		ssize_t	size,
		const union UdpAddress *	udp_addr,
		size_t	udp_addr_len,
		enum GNUNET_NetworkType	network_type
	)

We received a broadcast message.

Process it and all subsequent messages in the same packet.

Parameters

plugin	the UDP plugin
buf	the buffer with the message(s)
size	number of bytes in buf
udp_addr	address of the sender
udp_addr_len	number of bytes in udp_addr
network_type	network type of the sender's address

Definition at line 187 of file plugin_transport_udp_broadcasting.c.

{
  struct GNUNET_MessageStreamTokenizer *broadcast_mst;
  struct MstContext mc;
 
  broadcast_mst = GNUNET_MST_create (&broadcast_mst_cb,
                                     &mc);
  mc.plugin = plugin;
  mc.udp_addr = udp_addr;
  mc.udp_addr_len = udp_addr_len;
  mc.ats_address_network_type = network_type;
  GNUNET_MST_from_buffer (broadcast_mst,
                          buf, size,
                          GNUNET_NO,
                          GNUNET_NO);
  GNUNET_MST_destroy (broadcast_mst);
}

References broadcast_mst_cb(), buf, GNUNET_MST_create(), GNUNET_MST_destroy(), GNUNET_MST_from_buffer(), GNUNET_NO, mc, plugin, size, MstContext::udp_addr, and MstContext::udp_addr_len.

Referenced by udp_select_read().

Here is the call graph for this function:

Here is the caller graph for this function:

prepare_beacon()

static unsigned int prepare_beacon ( struct Plugin *  plugin, struct UDP_Beacon_Message *  msg  )

static

Definition at line 212 of file plugin_transport_udp_broadcasting.c.

{
  uint16_t hello_size;
  uint16_t msg_size;
 
  const struct GNUNET_MessageHeader *hello;
 
  hello = plugin->env->get_our_hello ();
  if (NULL == hello)
    return 0;
  hello_size = GNUNET_HELLO_size ((struct GNUNET_HELLO_Message *) hello);
  msg_size = hello_size + sizeof(struct UDP_Beacon_Message);
 
  if ((hello_size < (sizeof(struct GNUNET_MessageHeader))) ||
      (msg_size > (UDP_MTU)))
    return 0;
 
  msg->sender = *(plugin->env->my_identity);
  msg->header.size = htons (msg_size);
  msg->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_BROADCAST_BEACON);
  GNUNET_memcpy (&msg[1], hello, hello_size);
  return msg_size;
}

References GNUNET_HELLO_size(), GNUNET_memcpy, GNUNET_MESSAGE_TYPE_TRANSPORT_BROADCAST_BEACON, msg, plugin, GNUNET_MessageHeader::size, GNUNET_MessageHeader::type, and UDP_MTU.

Referenced by udp_ipv4_broadcast_send(), and udp_ipv6_broadcast_send().

Here is the call graph for this function:

Here is the caller graph for this function:

udp_ipv4_broadcast_send()

static void udp_ipv4_broadcast_send ( void *  cls )

static

Definition at line 239 of file plugin_transport_udp_broadcasting.c.

{
  struct BroadcastAddress *baddr = cls;
  struct Plugin *plugin = baddr->plugin;
  int sent;
  uint16_t msg_size;
  char buf[65536] GNUNET_ALIGN;
 
  baddr->broadcast_task = NULL;
 
  msg_size = prepare_beacon (plugin, (struct UDP_Beacon_Message *) &buf);
  if (0 != msg_size)
  {
    struct sockaddr_in *addr = (struct sockaddr_in *) baddr->addr;
 
    addr->sin_port = htons (plugin->port);
    sent = GNUNET_NETWORK_socket_sendto (plugin->sockv4, &buf, msg_size,
                                         (const struct sockaddr *) addr,
                                         baddr->addrlen);
    if (sent == GNUNET_SYSERR)
    {
      if ((ENETUNREACH == errno) || (ENETDOWN == errno))
      {
        /* "Network unreachable" or "Network down"
         *
         * This indicates that we just do not have network connectivity
         */
        GNUNET_log (GNUNET_ERROR_TYPE_BULK | GNUNET_ERROR_TYPE_WARNING,
                    "Network connectivity is down, cannot send beacon!\n");
      }
      else
        GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "sendto");
    }
    else
    {
      LOG (GNUNET_ERROR_TYPE_DEBUG,
           "Sent HELLO beacon broadcast with %i bytes to address %s\n", sent,
           GNUNET_a2s (baddr->addr, baddr->addrlen));
    }
  }
 
#ifdef __linux__
  /*
   * Cryogenic
   */
  if (NULL != baddr->cryogenic_fd)
  {
    baddr->cryogenic_times.delay_msecs =
      (plugin->broadcast_interval.rel_value_us / 1000.0) * 0.5;
    baddr->cryogenic_times.timeout_msecs =
      (plugin->broadcast_interval.rel_value_us / 1000.0) * 1.5;
 
    if (ioctl (baddr->cryogenic_fd->fd,
               PM_SET_DELAY_AND_TIMEOUT,
               &baddr->cryogenic_times) < 0)
    {
      GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "ioctl");
      baddr->broadcast_task =
        GNUNET_SCHEDULER_add_delayed (plugin->broadcast_interval,
                                      &udp_ipv4_broadcast_send, baddr);
    }
    else
      GNUNET_SCHEDULER_add_write_file (GNUNET_TIME_UNIT_FOREVER_REL,
                                       baddr->cryogenic_fd,
                                       &udp_ipv4_broadcast_send,
                                       baddr);
  }
  else
#endif
  baddr->broadcast_task =
    GNUNET_SCHEDULER_add_delayed (plugin->broadcast_interval,
                                  &udp_ipv4_broadcast_send, baddr);
}

References BroadcastAddress::addr, BroadcastAddress::addrlen, BroadcastAddress::broadcast_task, buf, GNUNET_a2s(), GNUNET_ALIGN, GNUNET_ERROR_TYPE_BULK, GNUNET_ERROR_TYPE_DEBUG, GNUNET_ERROR_TYPE_ERROR, GNUNET_ERROR_TYPE_WARNING, GNUNET_log, GNUNET_log_strerror, GNUNET_NETWORK_socket_sendto(), GNUNET_SCHEDULER_add_delayed(), GNUNET_SCHEDULER_add_write_file(), GNUNET_SYSERR, GNUNET_TIME_UNIT_FOREVER_REL, LOG, plugin, BroadcastAddress::plugin, and prepare_beacon().

Referenced by iface_proc().

Here is the call graph for this function:

Here is the caller graph for this function:

udp_ipv6_broadcast_send()

static void udp_ipv6_broadcast_send ( void *  cls )

static

Definition at line 315 of file plugin_transport_udp_broadcasting.c.

{
  struct BroadcastAddress *baddr = cls;
  struct Plugin *plugin = baddr->plugin;
  ssize_t sent;
  uint16_t msg_size;
  char buf[65536] GNUNET_ALIGN;
  const struct sockaddr_in6 *s6 = (const struct sockaddr_in6 *) baddr->addr;
 
  baddr->broadcast_task = NULL;
 
  msg_size = prepare_beacon (plugin, (struct UDP_Beacon_Message *) &buf);
  /* Note: unclear if this actually works to limit the multicast to
     the specified interface as we're not (necessarily) using a
     link-local multicast group and the kernel suggests that the
     scope ID is only respected for link-local addresses; however,
     if the scope ID is ignored, the kernel should just multicast
     on ALL interfaces, which is merely slightly less efficient;
     in that case, we might want to revert to only doing this
     once, and not per interface (hard to test...) */plugin->ipv6_multicast_address.sin6_scope_id = s6->sin6_scope_id;
  sent = GNUNET_NETWORK_socket_sendto (plugin->sockv6, &buf, msg_size,
                                       (const struct sockaddr *)
                                       &plugin->ipv6_multicast_address,
                                       sizeof(struct sockaddr_in6));
  plugin->ipv6_multicast_address.sin6_scope_id = 0;
  if (sent == GNUNET_SYSERR)
  {
    if ((ENETUNREACH == errno) || (ENETDOWN == errno))
    {
      /* "Network unreachable" or "Network down"
       *
       * This indicates that this system is IPv6 enabled, but does not
       * have a valid global IPv6 address assigned
       */GNUNET_log (GNUNET_ERROR_TYPE_BULK | GNUNET_ERROR_TYPE_WARNING,
                  "Network connectivity is down, cannot send beacon!\n");
    }
    else
      GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "sendto");
  }
  else
  {
    LOG (GNUNET_ERROR_TYPE_DEBUG,
         "Sending IPv6 HELLO beacon broadcast with %d bytes to address %s\n",
         (int) sent,
         GNUNET_a2s ((const struct sockaddr *) &plugin->ipv6_multicast_address,
                     sizeof(struct sockaddr_in6)));
  }
#ifdef __linux__
  /*
   * Cryogenic
   */
  if (NULL != baddr->cryogenic_fd)
  {
    baddr->cryogenic_times.delay_msecs =
      (plugin->broadcast_interval.rel_value_us / 1000.0) * 0.5;
    baddr->cryogenic_times.timeout_msecs =
      (plugin->broadcast_interval.rel_value_us / 1000.0) * 1.5;
 
    if (ioctl (baddr->cryogenic_fd->fd,
               PM_SET_DELAY_AND_TIMEOUT,
               &baddr->cryogenic_times) < 0)
    {
      GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "ioctl");
      baddr->broadcast_task =
        GNUNET_SCHEDULER_add_delayed (plugin->broadcast_interval,
                                      &udp_ipv6_broadcast_send, baddr);
    }
    else
      GNUNET_SCHEDULER_add_write_file (GNUNET_TIME_UNIT_FOREVER_REL,
                                       baddr->cryogenic_fd,
                                       &udp_ipv6_broadcast_send,
                                       baddr);
  }
  else
#endif
  baddr->broadcast_task =
    GNUNET_SCHEDULER_add_delayed (plugin->broadcast_interval,
                                  &udp_ipv6_broadcast_send, baddr);
}

References BroadcastAddress::addr, BroadcastAddress::broadcast_task, buf, GNUNET_a2s(), GNUNET_ALIGN, GNUNET_ERROR_TYPE_BULK, GNUNET_ERROR_TYPE_DEBUG, GNUNET_ERROR_TYPE_ERROR, GNUNET_ERROR_TYPE_WARNING, GNUNET_log, GNUNET_log_strerror, GNUNET_NETWORK_socket_sendto(), GNUNET_SCHEDULER_add_delayed(), GNUNET_SCHEDULER_add_write_file(), GNUNET_SYSERR, GNUNET_TIME_UNIT_FOREVER_REL, LOG, plugin, BroadcastAddress::plugin, and prepare_beacon().

Referenced by iface_proc().

Here is the call graph for this function:

Here is the caller graph for this function:

iface_proc()

static int iface_proc ( void *  cls, const char *  name, int  isDefault, const struct sockaddr *  addr, const struct sockaddr *  broadcast_addr, const struct sockaddr *  netmask, socklen_t  addrlen  )

static

Callback function invoked for each interface found.

Parameters

cls	closure with the struct Plugin
name	name of the interface (can be NULL for unknown)
isDefault	is this presumably the default interface
addr	address of this interface (can be NULL for unknown or unassigned)
broadcast_addr	the broadcast address (can be NULL for unknown or unassigned)
netmask	the network mask (can be NULL for unknown or unassigned)
addrlen	length of the address

Returns

GNUNET_OK to continue iteration, GNUNET_SYSERR to abort

Definition at line 409 of file plugin_transport_udp_broadcasting.c.

{
  struct Plugin *plugin = cls;
  struct BroadcastAddress *ba;
  enum GNUNET_NetworkType network;
 
  if (NULL == addr)
    return GNUNET_OK;
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "address %s for interface %s %p\n ",
              GNUNET_a2s (addr, addrlen), name, addr);
  if (NULL == broadcast_addr)
    return GNUNET_OK;
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "broadcast address %s for interface %s %p\n ",
              GNUNET_a2s (broadcast_addr, addrlen), name, broadcast_addr);
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "netmask %s for interface %s %p\n ",
              GNUNET_a2s (netmask, addrlen), name, netmask);
 
  network = plugin->env->get_address_type (plugin->env->cls, broadcast_addr,
                                           addrlen);
  if (GNUNET_NT_LOOPBACK == network)
  {
    /* Broadcasting on loopback does not make sense */
    return GNUNET_YES;
  }
 
  ba = GNUNET_new (struct BroadcastAddress);
  ba->plugin = plugin;
  ba->addr = GNUNET_malloc (addrlen);
  GNUNET_memcpy (ba->addr, broadcast_addr, addrlen);
  ba->addrlen = addrlen;
 
  if ((GNUNET_YES == plugin->enable_ipv4) &&
      (NULL != plugin->sockv4) &&
      (addrlen == sizeof(struct sockaddr_in)))
  {
#ifdef __linux__
    /*
     * setup Cryogenic FD for ipv4 broadcasting
     */
    char *filename;
 
    GNUNET_asprintf (&filename,
                     "/dev/cryogenic/%s",
                     name);
    if (0 == access (name, R_OK))
    {
      ba->cryogenic_fd =
        GNUNET_DISK_file_open (filename,
                               GNUNET_DISK_OPEN_WRITE,
                               GNUNET_DISK_PERM_NONE);
    }
    GNUNET_free (filename);
#endif
    ba->broadcast_task =
      GNUNET_SCHEDULER_add_now (&udp_ipv4_broadcast_send, ba);
  }
  if ((GNUNET_YES == plugin->enable_ipv6) &&
      (NULL != plugin->sockv6) &&
      (addrlen == sizeof(struct sockaddr_in6)))
  {
    /* Create IPv6 multicast request */
    struct ipv6_mreq multicastRequest;
    const struct sockaddr_in6 *s6 = (const struct
                                     sockaddr_in6 *) broadcast_addr;
 
    multicastRequest.ipv6mr_multiaddr =
      plugin->ipv6_multicast_address.sin6_addr;
    /* http://tools.ietf.org/html/rfc2553#section-5.2:
     *
     * IPV6_JOIN_GROUP
     *
     * Join a multicast group on a specified local interface.  If the
     * interface index is specified as 0, the kernel chooses the local
     * interface.  For example, some kernels look up the multicast
     * group in the normal IPv6 routing table and using the resulting
     * interface; we do this for each interface, so no need to use
     * zero (anymore...).
     */multicastRequest.ipv6mr_interface = s6->sin6_scope_id;
 
    /* Join the multicast group */
    if (GNUNET_OK !=
        GNUNET_NETWORK_socket_setsockopt
          (plugin->sockv6, IPPROTO_IPV6, IPV6_JOIN_GROUP,
          &multicastRequest, sizeof(multicastRequest)))
    {
      LOG (GNUNET_ERROR_TYPE_WARNING,
           "Failed to join IPv6 multicast group: IPv6 broadcasting not running\n");
    }
    else
    {
#ifdef __linux__
      /*
       * setup Cryogenic FD for ipv6 broadcasting
       */
      char *filename;
 
      GNUNET_asprintf (&filename,
                       "/dev/cryogenic/%s",
                       name);
      if (0 == access (name, R_OK))
      {
        ba->cryogenic_fd =
          GNUNET_DISK_file_open (filename,
                                 GNUNET_DISK_OPEN_WRITE,
                                 GNUNET_DISK_PERM_NONE);
      }
      GNUNET_free (filename);
#endif
      ba->broadcast_task =
        GNUNET_SCHEDULER_add_now (&udp_ipv6_broadcast_send, ba);
    }
  }
  GNUNET_CONTAINER_DLL_insert (plugin->broadcast_head,
                               plugin->broadcast_tail, ba);
  return GNUNET_OK;
}

References BroadcastAddress::addr, BroadcastAddress::addrlen, BroadcastAddress::broadcast_task, filename, GNUNET_a2s(), GNUNET_asprintf(), GNUNET_CONTAINER_DLL_insert, GNUNET_DISK_file_open(), GNUNET_DISK_OPEN_WRITE, GNUNET_DISK_PERM_NONE, GNUNET_ERROR_TYPE_DEBUG, GNUNET_ERROR_TYPE_WARNING, GNUNET_free, GNUNET_log, GNUNET_malloc, GNUNET_memcpy, GNUNET_NETWORK_socket_setsockopt(), GNUNET_new, GNUNET_NT_LOOPBACK, GNUNET_OK, GNUNET_SCHEDULER_add_now(), GNUNET_YES, LOG, name, plugin, BroadcastAddress::plugin, udp_ipv4_broadcast_send(), and udp_ipv6_broadcast_send().

Referenced by setup_broadcast().

Here is the call graph for this function:

Here is the caller graph for this function:

setup_broadcast()

void setup_broadcast	(	struct Plugin *	plugin,
		struct sockaddr_in6 *	server_addrv6,
		struct sockaddr_in *	server_addrv4
	)

Setup broadcasting subsystem.

Parameters

plugin
server_addrv6
server_addrv4

Definition at line 542 of file plugin_transport_udp_broadcasting.c.

{
  if (GNUNET_YES ==
      GNUNET_CONFIGURATION_get_value_yesno (plugin->env->cfg,
                                            "topology",
                                            "FRIENDS-ONLY"))
  {
    LOG (GNUNET_ERROR_TYPE_WARNING,
         _ (
           "Disabling HELLO broadcasting due to friend-to-friend only configuration!\n"));
    return;
  }
 
  if (GNUNET_YES != plugin->enable_broadcasting)
    return; /* We do not send, just receive */
 
  /* create IPv4 broadcast socket */
  if ((GNUNET_YES == plugin->enable_ipv4) && (NULL != plugin->sockv4))
  {
    static int yes = 1;
 
    if (GNUNET_NETWORK_socket_setsockopt
          (plugin->sockv4, SOL_SOCKET, SO_BROADCAST, &yes,
          sizeof(int)) != GNUNET_OK)
    {
      LOG (GNUNET_ERROR_TYPE_WARNING,
           _ (
             "Failed to set IPv4 broadcast option for broadcast socket on port %d\n"),
           ntohs (server_addrv4->sin_port));
    }
  }
  /* create IPv6 multicast socket */
  if ((GNUNET_YES == plugin->enable_ipv6) && (plugin->sockv6 != NULL))
  {
    memset (&plugin->ipv6_multicast_address, 0, sizeof(struct sockaddr_in6));
    GNUNET_assert (1 ==
                   inet_pton (AF_INET6, "FF05::13B",
                              &plugin->ipv6_multicast_address.sin6_addr));
    plugin->ipv6_multicast_address.sin6_family = AF_INET6;
    plugin->ipv6_multicast_address.sin6_port = htons (plugin->port);
  }
  GNUNET_OS_network_interfaces_list (&iface_proc, plugin);
}

References _, GNUNET_assert, GNUNET_CONFIGURATION_get_value_yesno(), GNUNET_ERROR_TYPE_WARNING, GNUNET_NETWORK_socket_setsockopt(), GNUNET_OK, GNUNET_OS_network_interfaces_list(), GNUNET_YES, iface_proc(), LOG, and plugin.

Referenced by libgnunet_plugin_transport_udp_init().

Here is the call graph for this function:

Here is the caller graph for this function:

stop_broadcast()

void stop_broadcast

(

struct Plugin *

plugin

)

Stop broadcasting subsystem.

Parameters

plugin

Definition at line 595 of file plugin_transport_udp_broadcasting.c.

{
  if (GNUNET_YES == plugin->enable_broadcasting)
  {
    /* Disable broadcasting */
    while (plugin->broadcast_head != NULL)
    {
      struct BroadcastAddress *p = plugin->broadcast_head;
 
      if (p->broadcast_task != NULL)
      {
        GNUNET_SCHEDULER_cancel (p->broadcast_task);
        p->broadcast_task = NULL;
      }
      if ((GNUNET_YES == plugin->enable_ipv6) &&
          (NULL != plugin->sockv6) &&
          (p->addrlen == sizeof(struct sockaddr_in6)))
      {
        /* Create IPv6 multicast request */
        struct ipv6_mreq multicastRequest;
        const struct sockaddr_in6 *s6 = (const struct sockaddr_in6 *) p->addr;
 
        multicastRequest.ipv6mr_multiaddr =
          plugin->ipv6_multicast_address.sin6_addr;
        multicastRequest.ipv6mr_interface = s6->sin6_scope_id;
 
        /* Leave the multicast group */
        if (GNUNET_OK ==
            GNUNET_NETWORK_socket_setsockopt
              (plugin->sockv6, IPPROTO_IPV6, IPV6_LEAVE_GROUP,
              &multicastRequest, sizeof(multicastRequest)))
        {
          GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "setsockopt");
        }
        else
        {
          LOG (GNUNET_ERROR_TYPE_DEBUG, "IPv6 multicasting stopped\n");
        }
      }
 
#ifdef __linux__
      GNUNET_DISK_file_close (p->cryogenic_fd);
#endif
      GNUNET_CONTAINER_DLL_remove (plugin->broadcast_head,
                                   plugin->broadcast_tail, p);
      GNUNET_free (p->addr);
      GNUNET_free (p);
    }
  }
}