/*
 * rfcomm_sppd.c
 */

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2003 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: rfcomm_sppd.c,v 1.4 2003/09/07 18:15:55 max Exp $
 */

#include <sys/stat.h>
#include <sys/types.h>
#define L2CAP_SOCKET_CHECKED
#include <bluetooth.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <limits.h>
#include <paths.h>
#include <sdp.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <termios.h>
#include <unistd.h>
#include <libutil.h>

#define SPPD_IDENT              "rfcomm_sppd"
#define SPPD_BUFFER_SIZE        1024
#define max(a, b)               (((a) > (b))? (a) : (b))

int             rfcomm_channel_lookup   (bdaddr_t const *local,
                                         bdaddr_t const *remote, 
                                         int service, int *channel, int *error);

static int      sppd_ttys_open  (char **tty, int *amaster, int *aslave);
static int      sppd_read       (int fd, char *buffer, int size);
static int      sppd_write      (int fd, char *buffer, int size);
static void     sppd_sighandler (int s);
static void     usage           (void);

static int      done;   /* are we done? */

/* Main */
int
main(int argc, char *argv[]) 
{
        struct sigaction         sa;
        struct sockaddr_rfcomm   ra;
        bdaddr_t                 addr;
        int                      n, background, channel, service,
                                 s, amaster, aslave, fd, doserver,
                                 dopty;
        fd_set                   rfd;
        char                    *tty = NULL, *ep = NULL, buf[SPPD_BUFFER_SIZE];

        memcpy(&addr, NG_HCI_BDADDR_ANY, sizeof(addr));
        background = channel = 0;
        service = SDP_SERVICE_CLASS_SERIAL_PORT;
        doserver = 0;
        dopty = 0;

        /* Parse command line options */
        while ((n = getopt(argc, argv, "a:bc:thS")) != -1) {
                switch (n) { 
                case 'a': /* BDADDR */
                        if (!bt_aton(optarg, &addr)) {
                                struct hostent  *he = NULL;

                                if ((he = bt_gethostbyname(optarg)) == NULL)
                                        errx(1, "%s: %s", optarg, hstrerror(h_errno));

                                memcpy(&addr, he->h_addr, sizeof(addr));
                        }
                        break;

                case 'c': /* RFCOMM channel */
                        channel = strtoul(optarg, &ep, 10);
                        if (*ep != '\0') {
                                channel = 0;
                                switch (tolower(optarg[0])) {
                                case 'd': /* DialUp Networking */
                                        service = SDP_SERVICE_CLASS_DIALUP_NETWORKING;
                                        break;

                                case 'f': /* Fax */
                                        service = SDP_SERVICE_CLASS_FAX;
                                        break;

                                case 'l': /* LAN */
                                        service = SDP_SERVICE_CLASS_LAN_ACCESS_USING_PPP;
                                        break;

                                case 's': /* Serial Port */
                                        service = SDP_SERVICE_CLASS_SERIAL_PORT;
                                        break;

                                default:
                                        errx(1, "Unknown service name: %s",
                                                optarg);
                                        /* NOT REACHED */
                                }
                        }
                        break;

                case 'b': /* Run in background */
                        background = 1;
                        break;

                case 't': /* Open pseudo TTY */
                        dopty = 1;
                        break;

                case 'S':
                        doserver = 1;
                        break;

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

        /* Check if we have everything we need */
        if (!doserver && memcmp(&addr, NG_HCI_BDADDR_ANY, sizeof(addr)) == 0)
                usage();
                /* NOT REACHED */

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

        if (sigaction(SIGTERM, &sa, NULL) < 0)
                err(1, "Could not sigaction(SIGTERM)");
 
        if (sigaction(SIGHUP, &sa, NULL) < 0)
                err(1, "Could not sigaction(SIGHUP)");
 
        if (sigaction(SIGINT, &sa, NULL) < 0)
                err(1, "Could not sigaction(SIGINT)");

        sa.sa_handler = SIG_IGN;
        sa.sa_flags = SA_NOCLDWAIT;

        if (sigaction(SIGCHLD, &sa, NULL) < 0)
                err(1, "Could not sigaction(SIGCHLD)");

        /* Open TTYs */
        if (dopty) {
                if (sppd_ttys_open(&tty, &amaster, &aslave) < 0)
                        exit(1);

                fd = amaster;
        } else {
                if (background)
                        usage();

                amaster = STDIN_FILENO;
                fd = STDOUT_FILENO;
        }

        /* Open RFCOMM connection */

        if (doserver) {
                struct sockaddr_rfcomm   ma;
                bdaddr_t                 bt_addr_any;
                sdp_sp_profile_t         sp;
                void                    *ss;
                uint32_t                 sdp_handle;
                int                      acceptsock, aaddrlen;

                acceptsock = socket(PF_BLUETOOTH, SOCK_STREAM,
                                        BLUETOOTH_PROTO_RFCOMM);
                if (acceptsock < 0)
                        err(1, "Could not create socket");

                memcpy(&bt_addr_any, NG_HCI_BDADDR_ANY, sizeof(bt_addr_any));

                memset(&ma, 0, sizeof(ma));
                ma.rfcomm_len = sizeof(ma);
                ma.rfcomm_family = AF_BLUETOOTH;
                memcpy(&ma.rfcomm_bdaddr, &bt_addr_any, sizeof(bt_addr_any));
                ma.rfcomm_channel = channel;

                if (bind(acceptsock, (struct sockaddr *)&ma, sizeof(ma)) < 0)
                        err(1, "Could not bind socket on channel %d", channel);
                if (listen(acceptsock, 10) != 0)
                        err(1, "Could not listen on socket");

                aaddrlen = sizeof(ma);
                if (getsockname(acceptsock, (struct sockaddr *)&ma, &aaddrlen) < 0)
                        err(1, "Could not get socket name");
                channel = ma.rfcomm_channel;

                ss = sdp_open_local(NULL);
                if (ss == NULL)
                        errx(1, "Unable to create local SDP session");
                if (sdp_error(ss) != 0)
                        errx(1, "Unable to open local SDP session. %s (%d)",
                            strerror(sdp_error(ss)), sdp_error(ss));
                memset(&sp, 0, sizeof(sp));
                sp.server_channel = channel;

                if (sdp_register_service(ss, SDP_SERVICE_CLASS_SERIAL_PORT,
                                &bt_addr_any, (void *)&sp, sizeof(sp),
                                &sdp_handle) != 0) {
                        errx(1, "Unable to register LAN service with "
                            "local SDP daemon. %s (%d)",
                            strerror(sdp_error(ss)), sdp_error(ss));
                }

                s = -1;
                while (s < 0) {
                        aaddrlen = sizeof(ra);
                        s = accept(acceptsock, (struct sockaddr *)&ra,
                            &aaddrlen);
                        if (s < 0)
                                err(1, "Unable to accept()");
                        if (memcmp(&addr, NG_HCI_BDADDR_ANY, sizeof(addr)) &&
                            memcmp(&addr, &ra.rfcomm_bdaddr, sizeof(addr))) {
                                warnx("Connect from wrong client");
                                close(s);
                                s = -1;
                        }
                }
                sdp_unregister_service(ss, sdp_handle);
                sdp_close(ss);
                close(acceptsock);
        } else {
                /* Check channel, if was not set then obtain it via SDP */
                if (channel == 0 && service != 0)
                        if (rfcomm_channel_lookup(NULL, &addr,
                                    service, &channel, &n) != 0)
                                errc(1, n, "Could not obtain RFCOMM channel");
                if (channel <= 0 || channel > 30)
                        errx(1, "Invalid RFCOMM channel number %d", channel);

                s = socket(PF_BLUETOOTH, SOCK_STREAM, BLUETOOTH_PROTO_RFCOMM);
                if (s < 0)
                        err(1, "Could not create socket");

                memset(&ra, 0, sizeof(ra));
                ra.rfcomm_len = sizeof(ra);
                ra.rfcomm_family = AF_BLUETOOTH;

                if (bind(s, (struct sockaddr *) &ra, sizeof(ra)) < 0)
                        err(1, "Could not bind socket");

                memcpy(&ra.rfcomm_bdaddr, &addr, sizeof(ra.rfcomm_bdaddr));
                ra.rfcomm_channel = channel;

                if (connect(s, (struct sockaddr *) &ra, sizeof(ra)) < 0)
                        err(1, "Could not connect socket");
        }

        /* Became daemon if required */
        if (background && daemon(0, 0) < 0)
                err(1, "Could not daemon()");

        openlog(SPPD_IDENT, LOG_NDELAY|LOG_PERROR|LOG_PID, LOG_DAEMON);
        syslog(LOG_INFO, "Starting on %s...", (tty != NULL)? tty : "stdin/stdout");

        /* Print used tty on stdout for wrappers to pick up */
        if (!background)
                fprintf(stdout, "%s\n", tty);

        for (done = 0; !done; ) {
                FD_ZERO(&rfd);
                FD_SET(amaster, &rfd);
                FD_SET(s, &rfd);

                n = select(max(amaster, s) + 1, &rfd, NULL, NULL, NULL);
                if (n < 0) {
                        if (errno == EINTR)
                                continue;

                        syslog(LOG_ERR, "Could not select(). %s",
                                        strerror(errno));
                        exit(1);
                }

                if (n == 0)
                        continue;

                if (FD_ISSET(amaster, &rfd)) {
                        n = sppd_read(amaster, buf, sizeof(buf));
                        if (n < 0) {
                                syslog(LOG_ERR, "Could not read master pty, " \
                                        "fd=%d. %s", amaster, strerror(errno));
                                exit(1);
                        }

                        if (n == 0)
                                break; /* XXX */

                        if (sppd_write(s, buf, n) < 0) {
                                syslog(LOG_ERR, "Could not write to socket, " \
                                        "fd=%d, size=%d. %s",
                                        s, n, strerror(errno));
                                exit(1);
                        }
                }

                if (FD_ISSET(s, &rfd)) {
                        n = sppd_read(s, buf, sizeof(buf));
                        if (n < 0) {
                                syslog(LOG_ERR, "Could not read socket, " \
                                        "fd=%d. %s", s, strerror(errno));
                                exit(1);
                        }

                        if (n == 0)
                                break;

                        if (sppd_write(fd, buf, n) < 0) {
                                syslog(LOG_ERR, "Could not write to master " \
                                        "pty, fd=%d, size=%d. %s",
                                        fd, n, strerror(errno));
                                exit(1);
                        }
                }
        }

        syslog(LOG_INFO, "Completed on %s", (tty != NULL)? tty : "stdin/stdout");
        closelog();

        close(s);

        if (tty != NULL) {
                close(aslave);
                close(amaster);
        }       

        return (0);
}

/* Open TTYs */
static int
sppd_ttys_open(char **tty, int *amaster, int *aslave)
{
        char             pty[PATH_MAX];
        struct termios   tio;

        cfmakeraw(&tio);

        if (openpty(amaster, aslave, pty, &tio, NULL) == -1) {
                syslog(LOG_ERR, "Could not openpty(). %s", strerror(errno));
                return (-1);
        }

        if ((*tty = strdup(pty)) == NULL) {
                syslog(LOG_ERR, "Could not strdup(). %s", strerror(errno));
                close(*aslave);
                close(*amaster);
                return (-1);
        }

        return (0);
} /* sppd_ttys_open */

/* Read data */
static int
sppd_read(int fd, char *buffer, int size)
{
        int     n;

again:
        n = read(fd, buffer, size);
        if (n < 0) {
                if (errno == EINTR)
                        goto again;

                return (-1);
        }

        return (n);
} /* sppd_read */

/* Write data */
static int
sppd_write(int fd, char *buffer, int size)
{
        int     n, wrote;

        for (wrote = 0; size > 0; ) {
                n = write(fd, buffer, size);
                switch (n) {
                case -1:
                        if (errno != EINTR)
                                return (-1);
                        break;

                case 0: 
                        /* XXX can happen? */
                        break;

                default:
                        wrote += n;
                        buffer += n;
                        size -= n;
                        break;
                }
        }

        return (wrote);
} /* sppd_write */

/* Signal handler */
static void
sppd_sighandler(int s)
{
        syslog(LOG_INFO, "Signal %d received. Total %d signals received\n",
                        s, ++ done);
} /* sppd_sighandler */
 
/* Display usage and exit */
static void
usage(void)
{
        fprintf(stdout,
"Usage: %s options\n" \
"Where options are:\n" \
"\t-a address Peer address (required in client mode)\n" \
"\t-b         Run in background\n" \
"\t-c channel RFCOMM channel to connect to or listen on\n" \
"\t-t         use slave pseudo tty (required in background mode)\n" \
"\t-S         Server mode\n" \
"\t-h         Display this message\n", SPPD_IDENT);
        exit(255);
} /* usage */