/*
This file is part of GNUnet
Copyright (C) 2010, 2011 GNUnet e.V.
GNUnet is free software: you can redistribute it and/or modify it
under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version.
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
* @file transport/plugin_transport_udp_broadcasting.c
* @brief Neighbour discovery with UDP
* @author Christian Grothoff
* @author Matthias Wachs
*/
#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"
#define LOG(kind, ...) GNUNET_log_from (kind, "transport-udp", __VA_ARGS__)
/* *********** Cryogenic ********** */
#ifdef __linux__
#include
#include
#include
#include
#include
#define PM_MAGIC 'k'
#define PM_SET_DELAY_AND_TIMEOUT _IOW (PM_MAGIC, 1, struct pm_times)
struct pm_times
{
unsigned long delay_msecs;
unsigned long timeout_msecs;
};
#endif
/************************************/
struct UDP_Beacon_Message
{
/**
* Message header.
*/
struct GNUNET_MessageHeader header;
/**
* What is the identity of the sender
*/
struct GNUNET_PeerIdentity sender;
};
struct BroadcastAddress
{
struct BroadcastAddress *next;
struct BroadcastAddress *prev;
/**
* ID of select broadcast task
*/
struct GNUNET_SCHEDULER_Task *broadcast_task;
struct Plugin *plugin;
struct sockaddr *addr;
socklen_t addrlen;
#ifdef __linux__
/**
* Cryogenic handle.
*/
struct GNUNET_DISK_FileHandle *cryogenic_fd;
/**
* Time out for cryogenic.
*/
struct pm_times cryogenic_times;
#endif
};
/**
* Client-specific context for #broadcast_mst_cb().
*/
struct MstContext
{
struct Plugin *plugin;
const union UdpAddress *udp_addr;
size_t udp_addr_len;
/**
* ATS network type.
*/
enum GNUNET_NetworkType ats_address_network_type;
};
/**
* Parse broadcast message received.
*
* @param cls the `struct Plugin`
* @param client the `struct MstContext` with sender address
* @param message the message we received
* @return #GNUNET_OK (always)
*/
static int
broadcast_mst_cb (void *cls,
const struct GNUNET_MessageHeader *message)
{
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;
}
/**
* We received a broadcast message. Process it and all subsequent
* messages in the same packet.
*
* @param plugin the UDP plugin
* @param buf the buffer with the message(s)
* @param size number of bytes in @a buf
* @param udp_addr address of the sender
* @param udp_addr_len number of bytes in @a udp_addr
* @param network_type network type of the sender's address
*/
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)
{
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);
}
static unsigned int
prepare_beacon (struct Plugin *plugin,
struct UDP_Beacon_Message *msg)
{
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;
}
static void
udp_ipv4_broadcast_send (void *cls)
{
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);
}
static void
udp_ipv6_broadcast_send (void *cls)
{
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);
}
/**
* Callback function invoked for each interface found.
*
* @param cls closure with the `struct Plugin`
* @param name name of the interface (can be NULL for unknown)
* @param isDefault is this presumably the default interface
* @param addr address of this interface (can be NULL for unknown or unassigned)
* @param broadcast_addr the broadcast address (can be NULL for unknown or unassigned)
* @param netmask the network mask (can be NULL for unknown or unassigned)
* @param addrlen length of the address
* @return #GNUNET_OK to continue iteration, #GNUNET_SYSERR to abort
*/
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)
{
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;
}
/**
* Setup broadcasting subsystem.
*
* @param plugin
* @param server_addrv6
* @param server_addrv4
*/
void
setup_broadcast (struct Plugin *plugin,
struct sockaddr_in6 *server_addrv6,
struct sockaddr_in *server_addrv4)
{
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);
}
/**
* Stop broadcasting subsystem.
*
* @param plugin
*/
void
stop_broadcast (struct Plugin *plugin)
{
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);
}
}
}
/* end of plugin_transport_udp_broadcasting.c */