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/*
* llmnrd -- LLMNR (RFC 4705) responder daemon.
*
* Copyright (C) 2014-2016 Tobias Klauser <tklauser@distanz.ch>
*
* This file is part of llmnrd.
*
* llmnrd 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, version 2 of the License.
*
* llmnrd 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 llmnrd. If not, see <http://www.gnu.org/licenses/>.
*/
#include <errno.h>
#include <getopt.h>
#include <signal.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/param.h>
#include "compiler.h"
#include "log.h"
#include "util.h"
#include "iface.h"
#include "llmnr.h"
#include "llmnr-packet.h"
static const char *short_opts = "H:p:6dhV";
static const struct option long_opts[] = {
{ "hostname", required_argument, NULL, 'H' },
{ "port", required_argument, NULL, 'p' },
{ "ipv6", no_argument, NULL, '6' },
{ "daemonize", no_argument, NULL, 'd' },
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
{ NULL, 0, NULL, 0 },
};
static void __noreturn usage_and_exit(int status)
{
fprintf(stdout, "Usage: llmnrd [OPTIONS]\n"
"Options:\n"
" -H, --hostname NAME set hostname to respond with (default: system hostname)\n"
" -p, --port NUM set port number to listen on (default: %d)\n"
" -6, --ipv6 enable LLMNR name resolution over IPv6\n"
" -d, --daemonize run as daemon in the background\n"
" -h, --help show this help and exit\n"
" -V, --version show version information and exit\n",
LLMNR_UDP_PORT);
exit(status);
}
static void __noreturn version_and_exit(void)
{
fprintf(stdout, "llmnrd %s %s\n"
"Copyright (C) 2014-2016 Tobias Klauser <tklauser@distanz.ch>\n"
"Licensed under the GNU General Public License, version 2\n",
VERSION_STRING, GIT_VERSION);
exit(EXIT_SUCCESS);
}
static void signal_handler(int sig)
{
switch (sig) {
case SIGINT:
case SIGQUIT:
case SIGTERM:
log_info("Interrupt received. Stopping llmnrd.\n");
iface_stop();
llmnr_stop();
break;
case SIGHUP:
default:
/* ignore */
break;
}
}
static void register_signal(int sig, void (*handler)(int))
{
sigset_t block_mask;
struct sigaction saction;
sigfillset(&block_mask);
saction.sa_handler = handler;
saction.sa_mask = block_mask;
saction.sa_flags = SA_RESTART;
if (sigaction(sig, &saction, NULL) != 0) {
log_err("Failed to register signal handler for %s (%d)\n",
strsignal(sig), sig);
}
}
int main(int argc, char **argv)
{
int c, ret = EXIT_FAILURE;
long num_arg;
bool daemonize = false, ipv6 = false;
char *hostname = NULL;
uint16_t port = LLMNR_UDP_PORT;
while ((c = getopt_long(argc, argv, short_opts, long_opts, NULL)) != -1) {
switch (c) {
case 'd':
daemonize = true;
break;
case 'H':
hostname = xstrdup(optarg);
break;
case 'p':
num_arg = strtol(optarg, NULL, 0);
if (num_arg < 0 || num_arg > UINT16_MAX) {
log_err("Invalid port number: %ld\n", num_arg);
return EXIT_FAILURE;
}
port = num_arg;
break;
case '6':
ipv6 = true;
break;
case 'V':
version_and_exit();
case 'h':
usage_and_exit(EXIT_SUCCESS);
default:
usage_and_exit(EXIT_FAILURE);
}
}
register_signal(SIGINT, signal_handler);
register_signal(SIGQUIT, signal_handler);
register_signal(SIGTERM, signal_handler);
register_signal(SIGHUP, signal_handler);
if (!hostname) {
hostname = xzalloc(MAXHOSTNAMELEN);
if (gethostname(hostname, MAXHOSTNAMELEN) != 0) {
log_err("Failed to get hostname");
return EXIT_FAILURE;
}
hostname[MAXHOSTNAMELEN - 1] = '\0';
}
if (daemonize) {
if (daemon(0, 0) != 0) {
log_err("Failed to daemonize process: %s\n", strerror(errno));
return EXIT_FAILURE;
}
}
if (llmnr_init(hostname, port, ipv6) < 0)
goto out;
if (iface_start_thread() < 0)
goto out;
ret = llmnr_run();
out:
free(hostname);
return ret;
}
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