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/*
device.c -- multicast socket
Copyright (C) 2002-2005 Ivo Timmermans,
2002-2014 Guus Sliepen <guus@tinc-vpn.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.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "system.h"
#include "conf.h"
#include "device.h"
#include "net.h"
#include "logger.h"
#include "netutl.h"
#include "utils.h"
#include "route.h"
#include "xalloc.h"
static const char *device_info = "multicast socket";
static uint64_t device_total_in = 0;
static uint64_t device_total_out = 0;
static struct addrinfo *ai = NULL;
static mac_t ignore_src = {{0}};
static bool setup_device(void) {
char *host;
char *port;
char *space;
int ttl = 1;
get_config_string(lookup_config(config_tree, "Interface"), &iface);
if(!get_config_string(lookup_config(config_tree, "Device"), &device)) {
logger(LOG_ERR, "Device variable required for %s", device_info);
return false;
}
host = xstrdup(device);
space = strchr(host, ' ');
if(!space) {
logger(LOG_ERR, "Port number required for %s", device_info);
free(host);
return false;
}
*space++ = 0;
port = space;
space = strchr(port, ' ');
if(space) {
*space++ = 0;
ttl = atoi(space);
}
ai = str2addrinfo(host, port, SOCK_DGRAM);
if(!ai) {
free(host);
return false;
}
device_fd = socket(ai->ai_family, SOCK_DGRAM, IPPROTO_UDP);
if(device_fd < 0) {
logger(LOG_ERR, "Creating socket failed: %s", sockstrerror(sockerrno));
free(host);
return false;
}
#ifdef FD_CLOEXEC
fcntl(device_fd, F_SETFD, FD_CLOEXEC);
#endif
static const int one = 1;
setsockopt(device_fd, SOL_SOCKET, SO_REUSEADDR, (void *)&one, sizeof(one));
if(bind(device_fd, ai->ai_addr, ai->ai_addrlen)) {
closesocket(device_fd);
logger(LOG_ERR, "Can't bind to %s %s: %s", host, port, sockstrerror(sockerrno));
free(host);
return false;
}
switch(ai->ai_family) {
#ifdef IP_ADD_MEMBERSHIP
case AF_INET: {
struct ip_mreq mreq;
struct sockaddr_in in;
memcpy(&in, ai->ai_addr, sizeof(in));
mreq.imr_multiaddr.s_addr = in.sin_addr.s_addr;
mreq.imr_interface.s_addr = htonl(INADDR_ANY);
if(setsockopt(device_fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, (void *)&mreq, sizeof(mreq))) {
logger(LOG_ERR, "Cannot join multicast group %s %s: %s", host, port, sockstrerror(sockerrno));
closesocket(device_fd);
free(host);
return false;
}
#ifdef IP_MULTICAST_LOOP
setsockopt(device_fd, IPPROTO_IP, IP_MULTICAST_LOOP, (const void *)&one, sizeof(one));
#endif
#ifdef IP_MULTICAST_TTL
setsockopt(device_fd, IPPROTO_IP, IP_MULTICAST_TTL, (void *)&ttl, sizeof(ttl));
#endif
}
break;
#endif
#ifdef IPV6_JOIN_GROUP
case AF_INET6: {
struct ipv6_mreq mreq;
struct sockaddr_in6 in6;
memcpy(&in6, ai->ai_addr, sizeof(in6));
memcpy(&mreq.ipv6mr_multiaddr, &in6.sin6_addr, sizeof(mreq.ipv6mr_multiaddr));
mreq.ipv6mr_interface = in6.sin6_scope_id;
if(setsockopt(device_fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, (void *)&mreq, sizeof(mreq))) {
logger(LOG_ERR, "Cannot join multicast group %s %s: %s", host, port, sockstrerror(sockerrno));
closesocket(device_fd);
free(host);
return false;
}
#ifdef IPV6_MULTICAST_LOOP
setsockopt(device_fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, (const void *)&one, sizeof(one));
#endif
#ifdef IPV6_MULTICAST_HOPS
setsockopt(device_fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, (void *)&ttl, sizeof(ttl));
#endif
}
break;
#endif
default:
logger(LOG_ERR, "Multicast for address family %x unsupported", ai->ai_family);
closesocket(device_fd);
free(host);
return false;
}
free(host);
logger(LOG_INFO, "%s is a %s", device, device_info);
return true;
}
static void close_device(void) {
close(device_fd);
free(device);
free(iface);
if(ai) {
freeaddrinfo(ai);
}
}
static bool read_packet(vpn_packet_t *packet) {
int lenin;
if((lenin = recv(device_fd, (void *)packet->data, MTU, 0)) <= 0) {
logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
device, strerror(errno));
return false;
}
if(!memcmp(&ignore_src, packet->data + 6, sizeof(ignore_src))) {
ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Ignoring loopback packet of %d bytes from %s", lenin, device_info);
packet->len = 0;
return true;
}
packet->len = lenin;
device_total_in += packet->len;
ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
device_info);
return true;
}
static bool write_packet(vpn_packet_t *packet) {
ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
packet->len, device_info);
if(sendto(device_fd, (void *)packet->data, packet->len, 0, ai->ai_addr, ai->ai_addrlen) < 0) {
logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
strerror(errno));
return false;
}
device_total_out += packet->len;
memcpy(&ignore_src, packet->data + 6, sizeof(ignore_src));
return true;
}
static void dump_device_stats(void) {
logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
logger(LOG_DEBUG, " total bytes in: %10"PRIu64, device_total_in);
logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
}
const devops_t multicast_devops = {
.setup = setup_device,
.close = close_device,
.read = read_packet,
.write = write_packet,
.dump_stats = dump_device_stats,
};
#if 0
static bool not_supported(void) {
logger(LOG_ERR, "Raw socket device not supported on this platform");
return false;
}
const devops_t multicast_devops = {
.setup = not_supported,
.close = NULL,
.read = NULL,
.write = NULL,
.dump_stats = NULL,
};
#endif
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