pid_t pid_start(const char *argv[], int argc, int drop_privs)
{
pid_t chproc = fork();
if (chproc == 0) {
/* Alter privileges. */
if (drop_privs) {
proc_update_privileges(conf()->uid, conf()->gid);
}
/* Duplicate, it doesn't run from stack address anyway. */
char **args = malloc((argc + 1) * sizeof(char*));
memset(args, 0, (argc + 1) * sizeof(char*));
int ci = 0;
for (int i = 0; i < argc; ++i) {
if (strlen(argv[i]) > 0) {
args[ci++] = strdup(argv[i]);
}
}
args[ci] = 0;
/* Execute command. */
fflush(stdout);
fflush(stderr);
execvp(args[0], args);
/* Execute failed. */
log_server_error("Failed to run executable '%s'\n", args[0]);
for (int i = 0; i < argc; ++i) {
free(args[i]);
}
free(args);
exit(1);
return -1;
}
return chproc;
}
int main(int argc, char **argv)
{
/* Parse command line arguments. */
int c = 0, li = 0;
int daemonize = 0;
const char *config_fn = CONF_DEFAULT_FILE;
const char *config_db = NULL;
const char *daemon_root = "/";
/* Long options. */
struct option opts[] = {
{"config", required_argument, 0, 'c' },
{"confdb", required_argument, 0, 'C' },
{"daemonize", optional_argument, 0, 'd'},
{"version", no_argument, 0, 'V'},
{"help", no_argument, 0, 'h'},
{0, 0, 0, 0}
};
while ((c = getopt_long(argc, argv, "c:C:dVh", opts, &li)) != -1) {
switch (c) {
case 'c':
config_fn = optarg;
break;
case 'C':
config_db = optarg;
break;
case 'd':
daemonize = 1;
if (optarg) {
daemon_root = optarg;
}
break;
case 'V':
printf("%s, version %s\n", "Knot DNS", PACKAGE_VERSION);
return EXIT_SUCCESS;
case 'h':
case '?':
help();
return EXIT_SUCCESS;
default:
help();
return EXIT_FAILURE;
}
}
/* Check for non-option parameters. */
if (argc - optind > 0) {
help();
return EXIT_FAILURE;
}
/* Now check if we want to daemonize. */
if (daemonize) {
if (make_daemon(1, 0) != 0) {
fprintf(stderr, "Daemonization failed, shutting down...\n");
return EXIT_FAILURE;
}
}
/* Clear file creation mask. */
umask(0);
/* Setup base signal handling. */
setup_signals();
/* Initialize cryptographic backend. */
dnssec_crypto_init();
atexit(dnssec_crypto_cleanup);
/* Initialize pseudorandom number generator. */
srand(time(NULL));
/* POSIX 1003.1e capabilities. */
setup_capabilities();
/* Default logging to std out/err. */
log_init();
/* Open configuration. */
conf_t *new_conf = NULL;
if (config_db == NULL) {
int ret = conf_new(&new_conf, conf_scheme, NULL);
if (ret != KNOT_EOK) {
log_fatal("failed to initialize configuration database "
"(%s)", knot_strerror(ret));
log_close();
return EXIT_FAILURE;
}
/* Import the configuration file. */
ret = conf_import(new_conf, config_fn, true);
if (ret != KNOT_EOK) {
log_fatal("failed to load configuration file (%s)",
knot_strerror(ret));
conf_free(new_conf, false);
log_close();
return EXIT_FAILURE;
}
new_conf->filename = strdup(config_fn);
} else {
/* Open configuration database. */
int ret = conf_new(&new_conf, conf_scheme, config_db);
if (ret != KNOT_EOK) {
log_fatal("failed to open configuration database '%s' "
"(%s)", config_db, knot_strerror(ret));
log_close();
return EXIT_FAILURE;
}
}
/* Run post-open config operations. */
int res = conf_post_open(new_conf);
if (res != KNOT_EOK) {
log_fatal("failed to use configuration (%s)", knot_strerror(res));
conf_free(new_conf, false);
log_close();
return EXIT_FAILURE;
}
conf_update(new_conf);
/* Initialize logging subsystem. */
log_reconfigure(conf(), NULL);
/* Initialize server. */
server_t server;
res = server_init(&server, conf_bg_threads(conf()));
if (res != KNOT_EOK) {
log_fatal("failed to initialize server (%s)", knot_strerror(res));
conf_free(conf(), false);
log_close();
return EXIT_FAILURE;
}
/* Reconfigure server interfaces.
* @note This MUST be done before we drop privileges. */
server_reconfigure(conf(), &server);
log_info("configured %zu zones", conf_id_count(conf(), C_ZONE));
/* Alter privileges. */
int uid, gid;
if (conf_user(conf(), &uid, &gid) != KNOT_EOK ||
log_update_privileges(uid, gid) != KNOT_EOK ||
proc_update_privileges(uid, gid) != KNOT_EOK) {
log_fatal("failed to drop privileges");
server_deinit(&server);
conf_free(conf(), false);
log_close();
return EXIT_FAILURE;
}
/* Check and create PID file. */
long pid = (long)getpid();
char *pidfile = NULL;
if (daemonize) {
pidfile = pid_check_and_create();
if (pidfile == NULL) {
server_deinit(&server);
conf_free(conf(), false);
log_close();
return EXIT_FAILURE;
}
log_info("PID stored in '%s'", pidfile);
if (chdir(daemon_root) != 0) {
log_warning("failed to change working directory to %s",
daemon_root);
} else {
log_info("changed directory to %s", daemon_root);
}
}
/* Now we're going multithreaded. */
rcu_register_thread();
/* Populate zone database. */
log_info("loading zones");
server_update_zones(conf(), &server);
/* Check number of loaded zones. */
if (knot_zonedb_size(server.zone_db) == 0) {
log_warning("no zones loaded");
}
/* Start it up. */
log_info("starting server");
conf_val_t async_val = conf_get(conf(), C_SRV, C_ASYNC_START);
res = server_start(&server, conf_bool(&async_val));
if (res != KNOT_EOK) {
log_fatal("failed to start server (%s)", knot_strerror(res));
server_deinit(&server);
rcu_unregister_thread();
pid_cleanup(pidfile);
log_close();
conf_free(conf(), false);
return EXIT_FAILURE;
}
if (daemonize) {
log_info("server started as a daemon, PID %ld", pid);
} else {
log_info("server started in the foreground, PID %ld", pid);
init_signal_started();
}
/* Start the event loop. */
event_loop(&server);
/* Teardown server and configuration. */
server_deinit(&server);
/* Free configuration. */
conf_free(conf(), false);
/* Unhook from RCU. */
rcu_unregister_thread();
/* Cleanup PID file. */
pid_cleanup(pidfile);
log_info("shutting down");
log_close();
return EXIT_SUCCESS;
}
