transmission/daemon/daemon.c

/*
 * This file Copyright (C) 2008-2014 Mnemosyne LLC
 *
 * It may be used under the GNU GPL versions 2 or 3
 * or any future license endorsed by Mnemosyne LLC.
 *
 */

#include <errno.h>
#include <stdio.h> /* printf */
#include <stdlib.h> /* atoi */

#ifdef HAVE_SYSLOG
#include <syslog.h>
#endif

#ifdef _WIN32
 #include <process.h> /* getpid */
#else
 #include <unistd.h> /* getpid */
#endif

#include <event2/event.h>

#include <libtransmission/transmission.h>
#include <libtransmission/error.h>
#include <libtransmission/file.h>
#include <libtransmission/tr-getopt.h>
#include <libtransmission/log.h>
#include <libtransmission/utils.h>
#include <libtransmission/variant.h>
#include <libtransmission/version.h>
#include <libtransmission/watchdir.h>

#ifdef USE_SYSTEMD
 #include <systemd/sd-daemon.h>
#else
 static void sd_notify (int status UNUSED, const char * str UNUSED) { }
 static void sd_notifyf (int status UNUSED, const char * fmt UNUSED, ...) { }
#endif

#include "daemon.h"

#define MY_NAME "transmission-daemon"

#define MEM_K 1024
#define MEM_K_STR "KiB"
#define MEM_M_STR "MiB"
#define MEM_G_STR "GiB"
#define MEM_T_STR "TiB"

#define DISK_K 1000
#define DISK_B_STR  "B"
#define DISK_K_STR "kB"
#define DISK_M_STR "MB"
#define DISK_G_STR "GB"
#define DISK_T_STR "TB"

#define SPEED_K 1000
#define SPEED_B_STR  "B/s"
#define SPEED_K_STR "kB/s"
#define SPEED_M_STR "MB/s"
#define SPEED_G_STR "GB/s"
#define SPEED_T_STR "TB/s"

static bool seenHUP = false;
static const char *logfileName = NULL;
static tr_sys_file_t logfile = TR_BAD_SYS_FILE;
static tr_session * mySession = NULL;
static tr_quark key_pidfile = 0;
static tr_quark key_watch_dir_force_generic = 0;
static struct event_base *ev_base = NULL;

/***
****  Config File
***/

static const char *
getUsage (void)
{
    return "Transmission " LONG_VERSION_STRING
           "  https://transmissionbt.com/\n"
           "A fast and easy BitTorrent client\n"
           "\n"
           MY_NAME " is a headless Transmission session\n"
           "that can be controlled via transmission-remote\n"
           "or the web interface.\n"
           "\n"
           "Usage: " MY_NAME " [options]";
}

static const struct tr_option options[] =
{

    { 'a', "allowed", "Allowed IP addresses. (Default: " TR_DEFAULT_RPC_WHITELIST ")", "a", 1, "<list>" },
    { 'b', "blocklist", "Enable peer blocklists", "b", 0, NULL },
    { 'B', "no-blocklist", "Disable peer blocklists", "B", 0, NULL },
    { 'c', "watch-dir", "Where to watch for new .torrent files", "c", 1, "<directory>" },
    { 'C', "no-watch-dir", "Disable the watch-dir", "C", 0, NULL },
    { 941, "incomplete-dir", "Where to store new torrents until they're complete", NULL, 1, "<directory>" },
    { 942, "no-incomplete-dir", "Don't store incomplete torrents in a different location", NULL, 0, NULL },
    { 'd', "dump-settings", "Dump the settings and exit", "d", 0, NULL },
    { 'e', "logfile", "Dump the log messages to this filename", "e", 1, "<filename>" },
    { 'f', "foreground", "Run in the foreground instead of daemonizing", "f", 0, NULL },
    { 'g', "config-dir", "Where to look for configuration files", "g", 1, "<path>" },
    { 'p', "port", "RPC port (Default: " TR_DEFAULT_RPC_PORT_STR ")", "p", 1, "<port>" },
    { 't', "auth", "Require authentication", "t", 0, NULL },
    { 'T', "no-auth", "Don't require authentication", "T", 0, NULL },
    { 'u', "username", "Set username for authentication", "u", 1, "<username>" },
    { 'v', "password", "Set password for authentication", "v", 1, "<password>" },
    { 'V', "version", "Show version number and exit", "V", 0, NULL },
    { 810, "log-error", "Show error messages", NULL, 0, NULL },
    { 811, "log-info", "Show error and info messages", NULL, 0, NULL },
    { 812, "log-debug", "Show error, info, and debug messages", NULL, 0, NULL },
    { 'w', "download-dir", "Where to save downloaded data", "w", 1, "<path>" },
    { 800, "paused", "Pause all torrents on startup", NULL, 0, NULL },
    { 'o', "dht", "Enable distributed hash tables (DHT)", "o", 0, NULL },
    { 'O', "no-dht", "Disable distributed hash tables (DHT)", "O", 0, NULL },
    { 'y', "lpd", "Enable local peer discovery (LPD)", "y", 0, NULL },
    { 'Y', "no-lpd", "Disable local peer discovery (LPD)", "Y", 0, NULL },
    { 830, "utp", "Enable uTP for peer connections", NULL, 0, NULL },
    { 831, "no-utp", "Disable uTP for peer connections", NULL, 0, NULL },
    { 'P', "peerport", "Port for incoming peers (Default: " TR_DEFAULT_PEER_PORT_STR ")", "P", 1, "<port>" },
    { 'm', "portmap", "Enable portmapping via NAT-PMP or UPnP", "m", 0, NULL },
    { 'M', "no-portmap", "Disable portmapping", "M", 0, NULL },
    { 'L', "peerlimit-global", "Maximum overall number of peers (Default: " TR_DEFAULT_PEER_LIMIT_GLOBAL_STR ")", "L", 1, "<limit>" },
    { 'l', "peerlimit-torrent", "Maximum number of peers per torrent (Default: " TR_DEFAULT_PEER_LIMIT_TORRENT_STR ")", "l", 1, "<limit>" },
    { 910, "encryption-required",  "Encrypt all peer connections", "er", 0, NULL },
    { 911, "encryption-preferred", "Prefer encrypted peer connections", "ep", 0, NULL },
    { 912, "encryption-tolerated", "Prefer unencrypted peer connections", "et", 0, NULL },
    { 'i', "bind-address-ipv4", "Where to listen for peer connections", "i", 1, "<ipv4 addr>" },
    { 'I', "bind-address-ipv6", "Where to listen for peer connections", "I", 1, "<ipv6 addr>" },
    { 'r', "rpc-bind-address", "Where to listen for RPC connections", "r", 1, "<ipv4 addr>" },
    { 953, "global-seedratio", "All torrents, unless overridden by a per-torrent setting, should seed until a specific ratio", "gsr", 1, "ratio" },
    { 954, "no-global-seedratio", "All torrents, unless overridden by a per-torrent setting, should seed regardless of ratio", "GSR", 0, NULL },
    { 'x', "pid-file", "Enable PID file", "x", 1, "<pid-file>" },
    { 0, NULL, NULL, NULL, 0, NULL }
};

static bool
reopen_log_file (const char *filename)
{
    tr_error * error = NULL;
    const tr_sys_file_t old_log_file = logfile;
    const tr_sys_file_t new_log_file = tr_sys_file_open (filename,
                                                         TR_SYS_FILE_WRITE | TR_SYS_FILE_CREATE | TR_SYS_FILE_APPEND,
                                                         0666, &error);

    if (new_log_file == TR_BAD_SYS_FILE)
    {
        fprintf (stderr, "Couldn't (re)open log file \"%s\": %s\n", filename, error->message);
        tr_error_free (error);
        return false;
    }

    logfile = new_log_file;

    if (old_log_file != TR_BAD_SYS_FILE)
        tr_sys_file_close (old_log_file, NULL);

    return true;
}

static const char*
getConfigDir (int argc, const char * const * argv)
{
    int c;
    const char * configDir = NULL;
    const char * optarg;
    const int ind = tr_optind;

    while ((c = tr_getopt (getUsage (), argc, argv, options, &optarg))) {
        if (c == 'g') {
            configDir = optarg;
            break;
        }
    }

    tr_optind = ind;

    if (configDir == NULL)
        configDir = tr_getDefaultConfigDir (MY_NAME);

    return configDir;
}

static tr_watchdir_status
onFileAdded (tr_watchdir_t   dir,
             const char    * name,
             void          * context)
{
    tr_session * session = context;

    if (!tr_str_has_suffix (name, ".torrent"))
        return TR_WATCHDIR_IGNORE;

    char * filename = tr_buildPath (tr_watchdir_get_path (dir), name, NULL);
    tr_ctor * ctor = tr_ctorNew (session);
    int err = tr_ctorSetMetainfoFromFile (ctor, filename);

    if (!err)
    {
        tr_torrentNew (ctor, &err, NULL);

        if (err == TR_PARSE_ERR)
            tr_logAddError ("Error parsing .torrent file \"%s\"", name);
        else
        {
            bool trash = false;
            const bool test = tr_ctorGetDeleteSource (ctor, &trash);

            tr_logAddInfo ("Parsing .torrent file successful \"%s\"", name);

            if (test && trash)
            {
                tr_error * error = NULL;

                tr_logAddInfo ("Deleting input .torrent file \"%s\"", name);
                if (!tr_sys_path_remove (filename, &error))
                {
                    tr_logAddError ("Error deleting .torrent file: %s", error->message);
                    tr_error_free (error);
                }
            }
            else
            {
                char * new_filename = tr_strdup_printf ("%s.added", filename);
                tr_sys_path_rename (filename, new_filename, NULL);
                tr_free (new_filename);
            }
        }
    }
    else
    {
        err = TR_PARSE_ERR;
    }

    tr_ctorFree (ctor);
    tr_free (filename);

    return err == TR_PARSE_ERR ? TR_WATCHDIR_RETRY : TR_WATCHDIR_ACCEPT;
}

static void
printMessage (tr_sys_file_t logfile, int level, const char * name, const char * message, const char * file, int line)
{
    if (logfile != TR_BAD_SYS_FILE)
    {
        char timestr[64];
        tr_logGetTimeStr (timestr, sizeof (timestr));
        if (name)
            tr_sys_file_write_fmt (logfile, "[%s] %s %s (%s:%d)" TR_NATIVE_EOL_STR,
                                   NULL, timestr, name, message, file, line);
        else
            tr_sys_file_write_fmt (logfile, "[%s] %s (%s:%d)" TR_NATIVE_EOL_STR,
                                   NULL, timestr, message, file, line);
    }
#ifdef HAVE_SYSLOG
    else /* daemon... write to syslog */
    {
        int priority;

        /* figure out the syslog priority */
        switch (level) {
            case TR_LOG_ERROR: priority = LOG_ERR; break;
            case TR_LOG_DEBUG: priority = LOG_DEBUG; break;
            default:           priority = LOG_INFO; break;
        }

        if (name)
            syslog (priority, "%s %s (%s:%d)", name, message, file, line);
        else
            syslog (priority, "%s (%s:%d)", message, file, line);
    }
#else
    (void) level;
#endif
}

static void
pumpLogMessages (tr_sys_file_t logfile)
{
    const tr_log_message * l;
    tr_log_message * list = tr_logGetQueue ();

    for (l=list; l!=NULL; l=l->next)
        printMessage (logfile, l->level, l->name, l->message, l->file, l->line);

    if (logfile != TR_BAD_SYS_FILE)
        tr_sys_file_flush (logfile, NULL);

    tr_logFreeQueue (list);
}

static void
reportStatus (void)
{
    const double up = tr_sessionGetRawSpeed_KBps (mySession, TR_UP);
    const double dn = tr_sessionGetRawSpeed_KBps (mySession, TR_DOWN);

    if (up>0 || dn>0)
        sd_notifyf (0, "STATUS=Uploading %.2f KBps, Downloading %.2f KBps.\n", up, dn);
    else
        sd_notify (0, "STATUS=Idle.\n");
}

static void
periodicUpdate (evutil_socket_t   fd UNUSED,
                short             what UNUSED,
                void            * context UNUSED)
{
    pumpLogMessages (logfile);
    reportStatus ();
}

static tr_rpc_callback_status
on_rpc_callback (tr_session            * session UNUSED,
                 tr_rpc_callback_type    type,
                 struct tr_torrent     * tor UNUSED,
                 void                  * user_data UNUSED)
{
    if (type == TR_RPC_SESSION_CLOSE)
        event_base_loopexit(ev_base, NULL);
    return TR_RPC_OK;
}

static bool
parse_args (int           argc,
            const char ** argv,
            tr_variant  * settings,
            bool        * paused,
            bool        * dump_settings,
            bool        * foreground,
            int         * exit_code)
{
    int c;
    const char * optarg;

    *paused = false;
    *dump_settings = false;
    *foreground = false;

    tr_optind = 1;
    while ((c = tr_getopt (getUsage (), argc, argv, options, &optarg))) {
        switch (c) {
            case 'a': tr_variantDictAddStr  (settings, TR_KEY_rpc_whitelist, optarg);
                      tr_variantDictAddBool (settings, TR_KEY_rpc_whitelist_enabled, true);
                      break;
            case 'b': tr_variantDictAddBool (settings, TR_KEY_blocklist_enabled, true);
                      break;
            case 'B': tr_variantDictAddBool (settings, TR_KEY_blocklist_enabled, false);
                      break;
            case 'c': tr_variantDictAddStr  (settings, TR_KEY_watch_dir, optarg);
                      tr_variantDictAddBool (settings, TR_KEY_watch_dir_enabled, true);
                      break;
            case 'C': tr_variantDictAddBool (settings, TR_KEY_watch_dir_enabled, false);
                      break;
            case 941: tr_variantDictAddStr  (settings, TR_KEY_incomplete_dir, optarg);
                      tr_variantDictAddBool (settings, TR_KEY_incomplete_dir_enabled, true);
                      break;
            case 942: tr_variantDictAddBool (settings, TR_KEY_incomplete_dir_enabled, false);
                      break;
            case 'd': *dump_settings = true;
                      break;
            case 'e': if (reopen_log_file (optarg))
                          logfileName = optarg;
                      break;
            case 'f': *foreground = true;
                      break;
            case 'g': /* handled above */
                      break;
            case 'V': /* version */
                      fprintf (stderr, "%s %s\n", MY_NAME, LONG_VERSION_STRING);
                      *exit_code = 0;
                      return false;
            case 'o': tr_variantDictAddBool (settings, TR_KEY_dht_enabled, true);
                      break;
            case 'O': tr_variantDictAddBool (settings, TR_KEY_dht_enabled, false);
                      break;
            case 'p': tr_variantDictAddInt (settings, TR_KEY_rpc_port, atoi (optarg));
                      break;
            case 't': tr_variantDictAddBool (settings, TR_KEY_rpc_authentication_required, true);
                      break;
            case 'T': tr_variantDictAddBool (settings, TR_KEY_rpc_authentication_required, false);
                      break;
            case 'u': tr_variantDictAddStr (settings, TR_KEY_rpc_username, optarg);
                      break;
            case 'v': tr_variantDictAddStr (settings, TR_KEY_rpc_password, optarg);
                      break;
            case 'w': tr_variantDictAddStr (settings, TR_KEY_download_dir, optarg);
                      break;
            case 'P': tr_variantDictAddInt (settings, TR_KEY_peer_port, atoi (optarg));
                      break;
            case 'm': tr_variantDictAddBool (settings, TR_KEY_port_forwarding_enabled, true);
                      break;
            case 'M': tr_variantDictAddBool (settings, TR_KEY_port_forwarding_enabled, false);
                      break;
            case 'L': tr_variantDictAddInt (settings, TR_KEY_peer_limit_global, atoi (optarg));
                      break;
            case 'l': tr_variantDictAddInt (settings, TR_KEY_peer_limit_per_torrent, atoi (optarg));
                      break;
            case 800: *paused = true;
                      break;
            case 910: tr_variantDictAddInt (settings, TR_KEY_encryption, TR_ENCRYPTION_REQUIRED);
                      break;
            case 911: tr_variantDictAddInt (settings, TR_KEY_encryption, TR_ENCRYPTION_PREFERRED);
                      break;
            case 912: tr_variantDictAddInt (settings, TR_KEY_encryption, TR_CLEAR_PREFERRED);
                      break;
            case 'i': tr_variantDictAddStr (settings, TR_KEY_bind_address_ipv4, optarg);
                      break;
            case 'I': tr_variantDictAddStr (settings, TR_KEY_bind_address_ipv6, optarg);
                      break;
            case 'r': tr_variantDictAddStr (settings, TR_KEY_rpc_bind_address, optarg);
                      break;
            case 953: tr_variantDictAddReal (settings, TR_KEY_ratio_limit, atof (optarg));
                      tr_variantDictAddBool (settings, TR_KEY_ratio_limit_enabled, true);
                      break;
            case 954: tr_variantDictAddBool (settings, TR_KEY_ratio_limit_enabled, false);
                      break;
            case 'x': tr_variantDictAddStr (settings, key_pidfile, optarg);
                      break;
            case 'y': tr_variantDictAddBool (settings, TR_KEY_lpd_enabled, true);
                      break;
            case 'Y': tr_variantDictAddBool (settings, TR_KEY_lpd_enabled, false);
                      break;
            case 810: tr_variantDictAddInt (settings,  TR_KEY_message_level, TR_LOG_ERROR);
                      break;
            case 811: tr_variantDictAddInt (settings,  TR_KEY_message_level, TR_LOG_INFO);
                      break;
            case 812: tr_variantDictAddInt (settings,  TR_KEY_message_level, TR_LOG_DEBUG);
                      break;
            case 830: tr_variantDictAddBool (settings, TR_KEY_utp_enabled, true);
                      break;
            case 831: tr_variantDictAddBool (settings, TR_KEY_utp_enabled, false);
                      break;
            default:  tr_getopt_usage (MY_NAME, getUsage (), options);
                      *exit_code = 0;
                      return false;
        }
    }

    return true;
}

struct daemon_data
{
  tr_variant   settings;
  const char * configDir;
  bool         paused;
};

static void
daemon_reconfigure (void * arg UNUSED)
{
    if (!mySession)
    {
        tr_logAddInfo ("Deferring reload until session is fully started.");
        seenHUP = true;
    }
    else
    {
        tr_variant settings;
        const char * configDir;

        /* reopen the logfile to allow for log rotation */
        if (logfileName != NULL)
            reopen_log_file (logfileName);

        configDir = tr_sessionGetConfigDir (mySession);
        tr_logAddInfo ("Reloading settings from \"%s\"", configDir);
        tr_variantInitDict (&settings, 0);
        tr_variantDictAddBool (&settings, TR_KEY_rpc_enabled, true);
        tr_sessionLoadSettings (&settings, configDir, MY_NAME);
        tr_sessionSet (mySession, &settings);
        tr_variantFree (&settings);
        tr_sessionReloadBlocklists (mySession);
    }
}

static void
daemon_stop (void * arg UNUSED)
{
    event_base_loopexit (ev_base, NULL);
}

static int
daemon_start (void * raw_arg,
              bool   foreground)
{
    bool boolVal;
    const char * pid_filename;
    bool pidfile_created = false;
    tr_session * session = NULL;
    struct event * status_ev = NULL;
    tr_watchdir_t watchdir = NULL;

    struct daemon_data * const arg = raw_arg;
    tr_variant * const settings = &arg->settings;
    const char * const configDir = arg->configDir;

#ifndef HAVE_SYSLOG
    (void) foreground;
#endif

    sd_notifyf (0, "MAINPID=%d\n", (int)getpid());

    /* should go before libevent calls */
    tr_net_init ();

    /* setup event state */
    ev_base = event_base_new ();
    if (ev_base == NULL)
    {
        char buf[256];
        tr_snprintf (buf, sizeof (buf), "Failed to init daemon event state: %s", tr_strerror (errno));
        printMessage (logfile, TR_LOG_ERROR, MY_NAME, buf, __FILE__, __LINE__);
        return 1;
    }

    /* start the session */
    tr_formatter_mem_init (MEM_K, MEM_K_STR, MEM_M_STR, MEM_G_STR, MEM_T_STR);
    tr_formatter_size_init (DISK_K, DISK_K_STR, DISK_M_STR, DISK_G_STR, DISK_T_STR);
    tr_formatter_speed_init (SPEED_K, SPEED_K_STR, SPEED_M_STR, SPEED_G_STR, SPEED_T_STR);
    session = tr_sessionInit (configDir, true, settings);
    tr_sessionSetRPCCallback (session, on_rpc_callback, NULL);
    tr_logAddNamedInfo (NULL, "Using settings from \"%s\"", configDir);
    tr_sessionSaveSettings (session, configDir, settings);

    pid_filename = NULL;
    tr_variantDictFindStr (settings, key_pidfile, &pid_filename, NULL);
    if (pid_filename && *pid_filename)
    {
        tr_error * error = NULL;
        tr_sys_file_t fp = tr_sys_file_open (pid_filename,
                                             TR_SYS_FILE_WRITE | TR_SYS_FILE_CREATE | TR_SYS_FILE_TRUNCATE,
                                             0666, &error);
        if (fp != TR_BAD_SYS_FILE)
        {
            tr_sys_file_write_fmt (fp, "%d", NULL, (int)getpid ());
            tr_sys_file_close (fp, NULL);
            tr_logAddInfo ("Saved pidfile \"%s\"", pid_filename);
            pidfile_created = true;
        }
        else
        {
            tr_logAddError ("Unable to save pidfile \"%s\": %s", pid_filename, error->message);
            tr_error_free (error);
        }
    }

    if (tr_variantDictFindBool (settings, TR_KEY_rpc_authentication_required, &boolVal) && boolVal)
        tr_logAddNamedInfo (MY_NAME, "requiring authentication");

    mySession = session;

    /* If we got a SIGHUP during startup, process that now. */
    if (seenHUP)
        daemon_reconfigure (arg);

    /* maybe add a watchdir */
    if (tr_variantDictFindBool (settings, TR_KEY_watch_dir_enabled, &boolVal) && boolVal)
    {
        const char * dir;
        bool force_generic;

        if (!tr_variantDictFindBool (settings, key_watch_dir_force_generic, &force_generic))
          force_generic = false;

        if (tr_variantDictFindStr (settings, TR_KEY_watch_dir, &dir, NULL) && dir != NULL && *dir != '\0')
        {
            tr_logAddInfo ("Watching \"%s\" for new .torrent files", dir);
            if ((watchdir = tr_watchdir_new (dir, &onFileAdded, mySession, ev_base, force_generic)) == NULL)
                goto cleanup;
        }
    }

    /* load the torrents */
    {
        tr_torrent ** torrents;
        tr_ctor * ctor = tr_ctorNew (mySession);
        if (arg->paused)
            tr_ctorSetPaused (ctor, TR_FORCE, true);
        torrents = tr_sessionLoadTorrents (mySession, ctor, NULL);
        tr_free (torrents);
        tr_ctorFree (ctor);
    }

#ifdef HAVE_SYSLOG
    if (!foreground)
        openlog (MY_NAME, LOG_CONS|LOG_PID, LOG_DAEMON);
#endif

    /* Create new timer event to report daemon status */
    {
        struct timeval one_sec = { 1, 0 };
        status_ev = event_new(ev_base, -1, EV_PERSIST, &periodicUpdate, NULL);
        if (status_ev == NULL)
        {
            tr_logAddError("Failed to create status event %s", tr_strerror(errno));
            goto cleanup;
        }
        if (event_add(status_ev, &one_sec) == -1)
        {
            tr_logAddError("Failed to add status event %s", tr_strerror(errno));
            goto cleanup;
        }
    }

    sd_notify( 0, "READY=1\n" );

    /* Run daemon event loop */
    if (event_base_dispatch(ev_base) == -1)
    {
        tr_logAddError("Failed to launch daemon event loop: %s", tr_strerror(errno));
        goto cleanup;
    }

cleanup:
    sd_notify( 0, "STATUS=Closing transmission session...\n" );
    printf ("Closing transmission session...");

    tr_watchdir_free (watchdir);

    if (status_ev)
    {
        event_del(status_ev);
        event_free(status_ev);
    }
    event_base_free(ev_base);

    tr_sessionSaveSettings (mySession, configDir, settings);
    tr_sessionClose (mySession);
    pumpLogMessages (logfile);
    printf (" done.\n");

    /* shutdown */
#ifdef HAVE_SYSLOG
    if (!foreground)
    {
        syslog (LOG_INFO, "%s", "Closing session");
        closelog ();
    }
#endif

    /* cleanup */
    if (pidfile_created)
        tr_sys_path_remove (pid_filename, NULL);

    sd_notify (0, "STATUS=\n");

    return 0;
}

int
tr_main (int    argc,
         char * argv[])
{
    const dtr_callbacks cb =
    {
        .on_start       = &daemon_start,
        .on_stop        = &daemon_stop,
        .on_reconfigure = &daemon_reconfigure,
    };

    int ret;
    bool loaded, dumpSettings, foreground;
    tr_error * error = NULL;

    struct daemon_data arg;
    tr_variant * const settings = &arg.settings;
    const char ** const configDir = &arg.configDir;

    key_pidfile = tr_quark_new ("pidfile", 7);
    key_watch_dir_force_generic = tr_quark_new ("watch-dir-force-generic", 23);

    /* load settings from defaults + config file */
    tr_variantInitDict (settings, 0);
    tr_variantDictAddBool (settings, TR_KEY_rpc_enabled, true);
    *configDir = getConfigDir (argc, (const char* const *)argv);
    loaded = tr_sessionLoadSettings (settings, *configDir, MY_NAME);

    /* overwrite settings from the comamndline */
    if (!parse_args (argc, (const char**) argv, settings, &arg.paused, &dumpSettings, &foreground, &ret))
        goto cleanup;

    if (foreground && logfile == TR_BAD_SYS_FILE)
        logfile = tr_sys_file_get_std (TR_STD_SYS_FILE_ERR, NULL);

    if (!loaded)
    {
        printMessage (logfile, TR_LOG_ERROR, MY_NAME, "Error loading config file -- exiting.", __FILE__, __LINE__);
        ret = 1;
        goto cleanup;
    }

    if (dumpSettings)
    {
        char * str = tr_variantToStr (settings, TR_VARIANT_FMT_JSON, NULL);
        fprintf (stderr, "%s", str);
        tr_free (str);
        goto cleanup;
    }

    if (!dtr_daemon (&cb, &arg, foreground, &ret, &error))
    {
        char buf[256];
        tr_snprintf (buf, sizeof (buf), "Failed to daemonize: %s", error->message);
        printMessage (logfile, TR_LOG_ERROR, MY_NAME, buf, __FILE__, __LINE__);
        tr_error_free (error);
    }

cleanup:
    tr_variantFree (settings);

    return ret;
}