/*-
 * main.c
 *
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2004 Maksim Yevmenkin <m_evmenkin@yahoo.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $Id: main.c,v 1.8 2004/01/13 19:31:54 max Exp $
 */

#include <sys/select.h>
#define L2CAP_SOCKET_CHECKED
#include <bluetooth.h>
#include <errno.h>
#include <grp.h>
#include <pwd.h>
#include <signal.h>
#include <sdp.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "log.h"
#include "server.h"

#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/queue.h>
#include "profile.h"
#include "provider.h"

#define SDPD                    "sdpd"

static int32_t  drop_root       (char const *user, char const *group);
static void     sighandler      (int32_t s);
static void     usage           (void);

static int32_t  done;

/*
 * Bluetooth Service Discovery Procotol (SDP) daemon
 */

int
main(int argc, char *argv[])
{
        server_t                 server;
        char const              *control = SDP_LOCAL_PATH;
        char const              *user = "nobody", *group = "nobody";
        int32_t                  detach = 1, opt;
        struct sigaction         sa;

        while ((opt = getopt(argc, argv, "c:dg:hu:")) != -1) {
                switch (opt) {
                case 'c': /* control */
                        control = optarg;
                        break;

                case 'd': /* do not detach */
                        detach = 0;
                        break;

                case 'g': /* group */
                        group = optarg;
                        break;

                case 'u': /* user */
                        user = optarg;
                        break;

                case 'h':
                default:
                        usage();
                        /* NOT REACHED */
                }
        }

        log_open(SDPD, !detach);

        /* Become daemon if required */
        if (detach && daemon(0, 0) < 0) {
                log_crit("Could not become daemon. %s (%d)",
                        strerror(errno), errno);
                exit(1);
        }

        /* Set signal handlers */
        memset(&sa, 0, sizeof(sa));
        sa.sa_handler = sighandler;

        if (sigaction(SIGTERM, &sa, NULL) < 0 ||
            sigaction(SIGHUP,  &sa, NULL) < 0 ||
            sigaction(SIGINT,  &sa, NULL) < 0) {
                log_crit("Could not install signal handlers. %s (%d)",
                        strerror(errno), errno); 
                exit(1);
        }

        sa.sa_handler = SIG_IGN;
        if (sigaction(SIGPIPE, &sa, NULL) < 0) {
                log_crit("Could not install signal handlers. %s (%d)",
                        strerror(errno), errno); 
                exit(1);
        }

        /* Initialize server */
        if (server_init(&server, control) < 0)
                exit(1);

        if ((user != NULL || group != NULL) && drop_root(user, group) < 0)
                exit(1);

        for (done = 0; !done; ) {
                if (server_do(&server) != 0)
                        done ++;
        }

        server_shutdown(&server);
        log_close();

        return (0);
}

/*
 * Drop root
 */

static int32_t
drop_root(char const *user, char const *group)
{
        int      uid, gid;
        char    *ep;

        if ((uid = getuid()) != 0) {
                log_notice("Cannot set uid/gid. Not a superuser");
                return (0); /* dont do anything unless root */
        }

        gid = getgid();

        if (user != NULL) {
                uid = strtol(user, &ep, 10);
                if (*ep != '\0') {
                        struct passwd   *pwd = getpwnam(user);

                        if (pwd == NULL) {
                                log_err("Could not find passwd entry for " \
                                        "user %s", user);
                                return (-1);
                        }

                        uid = pwd->pw_uid;
                }
        }

        if (group != NULL) {
                gid = strtol(group, &ep, 10);
                if (*ep != '\0') {
                        struct group    *grp = getgrnam(group);

                        if (grp == NULL) {
                                log_err("Could not find group entry for " \
                                        "group %s", group);
                                return (-1);
                        }

                        gid = grp->gr_gid;
                }
        }

        if (setgid(gid) < 0) {
                log_err("Could not setgid(%s). %s (%d)",
                        group, strerror(errno), errno);
                return (-1);
        }

        if (setuid(uid) < 0) {
                log_err("Could not setuid(%s). %s (%d)",
                        user, strerror(errno), errno);
                return (-1);
        }

        return (0);
}

/*
 * Signal handler
 */

static void
sighandler(int32_t s)
{
        log_notice("Got signal %d. Total number of signals received %d",
                s, ++ done);
}

/*
 * Display usage information and quit
 */

static void
usage(void)
{
        fprintf(stderr,
"Usage: %s [options]\n" \
"Where options are:\n" \
"       -c      specify control socket name (default %s)\n" \
"       -d      do not detach (run in foreground)\n" \
"       -g grp  specify group\n" \
"       -h      display usage and exit\n" \
"       -u usr  specify user\n",
                SDPD, SDP_LOCAL_PATH);
        exit(255);
}