/* $Id$ */

/***
  This file is part of ivam2.

  ivam2 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.
  
  ivam2 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 ivam2; if not, write to the Free Software Foundation,
  Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <signal.h>
#include <assert.h>
#include <string.h>
#include <errno.h>
#include <grp.h>
#include <pwd.h>
#include <sys/types.h>
#include <stdlib.h>

#include <libdaemon/dlog.h>
#include <libdaemon/dfork.h>
#include <libdaemon/dpid.h>

#include "main.h"
#include "exec.h"
#include "modemman.h"
#include "msntab.h"
#include "cmdline.h"

oop_source* event_source = NULL;
struct gengetopt_args_info args;
const char *appname = NULL;

uid_t target_uid = 0;
gid_t target_gid = 0;

#define DEFAULT_MSNTABLE PKGSYSCONFDIR"/msntab"
#define IVAM_USER "ivam"
#define IVAM_GROUP "ivam"

static void *oop_exit_cb(oop_source *source, int sig, void *user) {
    daemon_log(LOG_ERR, "Recieved signal %s", sig == SIGINT ? "SIGINT" : (sig == SIGTERM ? "SIGTERM" : "UNKNWON"));
    return OOP_HALT;
}

static void *oop_reload_cb(oop_source *source, int sig, void *user) {
    daemon_log(LOG_ERR, "Reloading MSN table.");
    msntab_flush();

    if (msntab_load(args.msntab_arg ? args.msntab_arg : DEFAULT_MSNTABLE) < 0) {
        daemon_log(LOG_ERR, "Ignoring all calls.");
        msntab_flush();
    }

    return OOP_CONTINUE;
}

static void *oop_dump_cb(oop_source *source, int sig, void *user) {
    msntab_dump();
    return OOP_CONTINUE;
}


static int change_uid_gid(void) {
    struct passwd *pw;
    
    if (args.no_drop_root_flag)
        return 0;
        
    if (initgroups(IVAM_USER, target_gid) != 0) {
        daemon_log(LOG_ERR, "Failed to change group list: %s", strerror(errno));
        return -1;
    }
    
    if (setgid(target_gid) != 0) {
        daemon_log(LOG_ERR, "Failed to change GID: %s", strerror(errno));
        return -1;
    }
    
    if (setuid(target_uid) != 0) {
        daemon_log(LOG_ERR, "Failed to change UID: %s", strerror(errno));
        return -1;
    }

    if ((pw = getpwuid(target_uid))) {
        setenv("USER", pw->pw_name, 1);
        setenv("LOGNAME", pw->pw_name, 1);
        setenv("HOME", pw->pw_dir, 1);
    } else {
        unsetenv("USER");
        unsetenv("LOGNAME");
        unsetenv("HOME");
    }
    
    daemon_log(LOG_INFO, "Successfully dropped root privileges.");
    
    return 0;
}

static int get_target_uid_gid(void) {
    struct passwd *pw;
    struct group * gr;

    if (args.no_drop_root_flag) {
        target_uid = getuid();
        target_gid = getgid();
        return 0;
    }

    if (!(pw = getpwnam(IVAM_USER))) {
        daemon_log(LOG_ERR, "Failed to find user '%s'.", IVAM_USER);
        return -1;
    }

    if (!(gr = getgrnam(IVAM_GROUP))) {
        daemon_log(LOG_ERR, "Failed to find group '%s'.", IVAM_GROUP);
        return -1;
    }

    target_uid = pw->pw_uid;
    target_gid = gr->gr_gid;
    
    daemon_log(LOG_INFO, "Found user '%s' (UID %lu) and group '%s' (GID %lu).", IVAM_USER, (unsigned long) target_uid, IVAM_GROUP, (unsigned long) target_gid);

    return 0;
}

int main_loop(void) {
    int r = -1, retval_sent = 0;
    oop_source_sys *sys = NULL;

    daemon_log(LOG_INFO, "Starting up "PACKAGE" version "VERSION" <"PACKAGE_BUGREPORT">.");

    if (get_target_uid_gid() < 0)
        goto finish;

    setenv("PATH", BINDIR":/usr/sbin:/usr/bin:/sbin:/bin/:/usr/local/sbin:/usr/local/bin", 1);
    
    daemon_log(LOG_INFO, "Path set to '%s'.", getenv("PATH"));
    
    if (!(sys = oop_sys_new())) {
        daemon_log(LOG_ERR, "Failed to create system source.");
        goto finish;
    }

    event_source = oop_sys_source(sys);
    assert(event_source);
    
    if (modem_manager_init(args.channels_arg) < 0)
        goto finish;

    if (change_uid_gid() < 0)
        goto finish;

    if (child_process_init() < 0)
        goto finish;
    
    if (msntab_load(args.msntab_arg ? args.msntab_arg : DEFAULT_MSNTABLE) < 0)
        goto finish;

    event_source->on_signal(event_source, SIGINT, oop_exit_cb, NULL);
    event_source->on_signal(event_source, SIGTERM, oop_exit_cb, NULL);
    event_source->on_signal(event_source, SIGHUP, oop_reload_cb, NULL);
    event_source->on_signal(event_source, SIGUSR1, oop_dump_cb, NULL);
    signal(SIGPIPE, SIG_IGN);

    if (!args.no_daemon_flag) {
        daemon_retval_send(0);
        retval_sent = 1;
    }
    
    daemon_log(LOG_INFO, "Start up complete.");
    
    if (oop_sys_run(sys) == OOP_ERROR) {
        daemon_log(LOG_ERR, "oop_sys_new() returned OOP_ERROR");
        goto finish;
    }

    r = 0;
    
finish:
    
    daemon_log(LOG_INFO, "Shutting down.");

    if (!retval_sent && !args.no_daemon_flag)
        daemon_retval_send(1);
    
    event_source->cancel_signal(event_source, SIGTERM, oop_exit_cb, NULL);
    event_source->cancel_signal(event_source, SIGINT, oop_exit_cb, NULL);
    event_source->cancel_signal(event_source, SIGHUP, oop_reload_cb, NULL);
    event_source->cancel_signal(event_source, SIGUSR1, oop_dump_cb, NULL);

    msntab_flush();
    
    modem_manager_done();
    child_process_done();

    if (sys) {
        event_source = NULL;
        oop_sys_delete(sys);
    }

    daemon_log(LOG_INFO, "Shut down complete.");
    
    return r;
}

int main(int argc, char*argv[]) {
    pid_t pid;
    int ret;

    appname = daemon_pid_file_ident = daemon_log_ident = daemon_ident_from_argv0(argv[0]);

    cmdline_parser(argc, argv, &args);

    if (args.no_syslog_flag)
        daemon_log_use = DAEMON_LOG_STDERR;
    
    if (args.kill_flag) {
        int ret;
        
        if ((ret = daemon_pid_file_kill_wait(SIGINT, 5)) < 0)
            daemon_log(LOG_WARNING, "Failed to kill daemon: %s", strerror(errno));

        return ret  < 0 ? 1 : 0;
    }

    if (args.reload_flag || args.info_flag) {
        int ret;
        
        if ((ret = daemon_pid_file_kill(args.reload_flag ? SIGHUP : SIGUSR1)) < 0)
            daemon_log(LOG_WARNING, "Failed to kill daemon: %s", strerror(errno));

        return ret < 0 ? 1 : 0;
    }

    if (args.check_flag) {
        if ((pid = daemon_pid_file_is_running()) >= 0)
            daemon_log(LOG_INFO, "Daemon running on PID %u.", pid);
        else
            daemon_log(LOG_INFO, "Daemon not running.");

        return pid >= 0 ? 0 : 1;
    }

    if ((pid = daemon_pid_file_is_running()) >= 0) {
        daemon_log(LOG_ERR, "Daemon already running on PID %u.", pid);
        return 1;
    }

    if (!args.no_daemon_flag) {
        daemon_retval_init();

        if ((pid = daemon_fork()) < 0) {
            daemon_retval_done();
            return 1;
        } else if (pid) {
            int ret;
            
            if ((ret = daemon_retval_wait(20)) < 0) {
                daemon_log(LOG_ERR, "Failed to recieve return value from daemon process.");
                return 255;
            }

            if (ret)
                daemon_log(LOG_ERR, "Daemon returned %i as return value.", ret);
            return ret;
        }
    }

    if (daemon_pid_file_create() < 0) {
        daemon_log(LOG_ERR, "Could not create PID file (%s).", strerror(errno));
        
        if (!args.no_daemon_flag)
            daemon_retval_send(1);
        
        return 1;
    }

    ret = main_loop() < 0 ? 1 : 0;

    if (daemon_pid_file_remove() < 0)
        daemon_log(LOG_WARNING, "Failed to remove PID file (%s).", strerror(errno));

    return ret;
}