/*-
 * Copyright (c) 1990, 1991, 1993
 *      The Regents of the University of California.  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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 * @(#) Copyright (c) 1990, 1991, 1993 The Regents of the University of California.  All rights reserved.
 * @(#)startslip.c      8.1 (Berkeley) 6/5/93
 * $FreeBSD: src/sbin/startslip/startslip.c,v 1.31.2.1 2000/05/07 18:26:51 joe Exp $
 */

#include <sys/types.h>
#include <sys/time.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <libutil.h>
#include <paths.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <termios.h>
#include <unistd.h>

#include <net/slip.h>

#define DEFAULT_BAUD    B115200
int     speed = DEFAULT_BAUD;
#define FC_NONE         0       /* flow control: none */
#define FC_HW           1       /* flow control: hardware (RTS/CTS) */
int     flowcontrol = FC_NONE;
int     modem_control = 1;      /* !CLOCAL+HUPCL iff we watch carrier. */
int     sl_unit = -1;
int     uucp_lock = 0;          /* uucp locking */
char    *annex;
char    *username;
int     hup;
int     terminate;
int     locked = 0;             /* uucp lock active */
int     logged_in = 0;
int     wait_time = 60;         /* then back off */
int     script_timeout = 90;    /* connect script default timeout */
time_t  conn_time, start_time;
int     MAXTRIES = 6;           /* w/60 sec and doubling, takes an hour */
#define PIDFILE         "%sstartslip.%s.pid"

#define MAXDIALS 20
char *dials[MAXDIALS];
int diali, dialc;

int fd = -1;
FILE *pfd;
char *dvname, *devicename;
char my_pidfile[80];

#ifdef DEBUG
int     debug = 1;
#undef LOG_ERR
#undef LOG_INFO
#define syslog fprintf
#define LOG_ERR stderr
#define LOG_INFO stderr
#else
int     debug = 0;
#endif
#define printd  if (debug) printf

static int carrier(void);
static void down(int);
static int get_line(char *, int, int, time_t);
static void usage(void);
static void sighup(int);
static void sigterm(int);
static void sigurg(int);

int
main(int argc, char **argv)
{
        char *cp, **ap;
        int ch, disc;
        FILE *wfd = NULL;
        char *dialerstring = NULL, buf[BUFSIZ];
        int unitnum, keepal = 0, outfill = 0;
        char unitname[32];
        char *password;
        char *upscript = NULL, *downscript = NULL;
        int first = 1, tries = 0;
        time_t fintimeout;
        long lpid;
        pid_t pid;
        struct termios t;
        int result;

        while ((ch = getopt(argc, argv, "dhlb:s:t:w:A:U:D:W:K:O:S:L")) != -1)
                switch (ch) {
                case 'd':
                        debug = 1;
                        break;
                case 'b':
                        speed = atoi(optarg);
                        break;
                case 's':
                        if (diali >= MAXDIALS)
                                errx(1, "max dial strings number (%d) exceeded", MAXDIALS);
                        dials[diali++] = strdup(optarg);
                        break;
                case 't':
                        script_timeout = atoi(optarg);
                        break;
                case 'w':
                        wait_time = atoi(optarg);
                        break;
                case 'W':
                        MAXTRIES = atoi(optarg);
                        break;
                case 'A':
                        annex = strdup(optarg);
                        break;
                case 'U':
                        upscript = strdup(optarg);
                        break;
                case 'D':
                        downscript = strdup(optarg);
                        break;
                case 'L':
                        uucp_lock = 1;
                        break;
                case 'l':
                        modem_control = 0;
                        break;
                case 'h':
                        flowcontrol = FC_HW;
                        break;
                case 'K':
                        keepal = atoi(optarg);
                        break;
                case 'O':
                        outfill = atoi(optarg);
                        break;
                case 'S':
                        sl_unit = atoi(optarg);
                        break;
                case '?':
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        if (argc != 3)
                usage();

        /*
         * Copy these so they exist after we clobber them.
         */
        devicename = strdup(argv[0]);
        username = strdup(argv[1]);
        password = strdup(argv[2]);

        /*
         * Security hack.  Do not want private information such as the
         * password and possible phone number to be left around.
         * So we clobber the arguments.
         */
        for (ap = argv - optind + 1; ap < argv + 3; ap++)
                for (cp = *ap; *cp != 0; cp++)
                        *cp = '\0';

        openlog("startslip", LOG_PID|LOG_PERROR, LOG_DAEMON);

        if (debug)
                setbuf(stdout, NULL);

        signal(SIGTERM, sigterm);
        if ((dvname = strrchr(devicename, '/')) == NULL)
                dvname = devicename;
        else
                dvname++;

        result = snprintf(my_pidfile, sizeof(my_pidfile),
                          PIDFILE, _PATH_VARRUN, dvname);
        if (result < 0 || (unsigned int)result >= sizeof(my_pidfile))
                usage();

        if ((pfd = fopen(my_pidfile, "r")) != NULL) {
                if (fscanf(pfd, "%ld\n", &lpid) == 1) {
                        pid = lpid;
                        if (pid == lpid && pid > 0)
                                kill(pid, SIGTERM);
                }
                fclose(pfd);
                pfd = NULL;     /* not remove pidfile yet */
                sleep(5);       /* allow down script to be completed */
        } else
restart:
        signal(SIGHUP, SIG_IGN);
        signal(SIGURG, SIG_IGN);
        hup = 0;
        if (wfd) {
                printd("fclose, ");
                fclose(wfd);
                conn_time = time(NULL) - start_time;
                if (uucp_lock)
                        uu_unlock(dvname);
                locked = 0;
                wfd = NULL;
                fd = -1;
                sleep(5);
        } else if (fd >= 0) {
                printd("close, ");
                close(fd);
                conn_time = time(NULL) - start_time;
                if (uucp_lock)
                        uu_unlock(dvname);
                locked = 0;
                fd = -1;
                sleep(5);
        }
        if (logged_in) {
                syslog(LOG_INFO, "%s: connection time elapsed: %ld secs",
                    username, (long)conn_time);
                sprintf(buf, "LINE=%d %s %s down",
                diali ? (dialc - 1) % diali : 0,
                downscript ? downscript : "/sbin/ifconfig" , unitname);
                system(buf);
                logged_in = 0;
        }
        if (terminate)
                down(0);
        tries++;
        if (MAXTRIES > 0 && tries > MAXTRIES) {
                syslog(LOG_ERR, "%s: exiting login after %d tries", username, tries);
                /* ???
                if (first)
                */
                        down(3);
        }
        if (tries > 1) {
                syslog(LOG_INFO, "%s: sleeping %d seconds (%d tries)",
                        username, wait_time * (tries - 1), tries);
                sleep(wait_time * (tries - 1));
                if (terminate)
                        goto restart;
        }

        if (daemon(1, debug) < 0) {
                syslog(LOG_ERR, "%s: daemon: %m", username);
                down(2);
        }

        pid = getpid();
        printd("restart: pid %ld: ", (long)pid);
        if ((pfd = fopen(my_pidfile, "w")) != NULL) {
                fprintf(pfd, "%ld\n", (long)pid);
                fclose(pfd);
        }
        printd("open");
        if (uucp_lock) {
                int res;
                if ((res = uu_lock(dvname)) != UU_LOCK_OK) {
                        if (res != UU_LOCK_INUSE)
                                syslog(LOG_ERR, "uu_lock: %s", uu_lockerr(res));
                        syslog(LOG_ERR, "%s: can't lock %s", username, devicename);
                        goto restart;
                }
                locked = 1;
        }
        if ((fd = open(devicename, O_RDWR | O_NONBLOCK)) < 0) {
                syslog(LOG_ERR, "%s: open %s: %m", username, devicename);
                if (first)
                        down(1);
                else {
                        if (uucp_lock)
                                uu_unlock(dvname);
                        locked = 0;
                        goto restart;
                }
        }
        printd(" %d", fd);
        signal(SIGHUP, sighup);
        if (ioctl(fd, TIOCSCTTY, 0) < 0) {
                syslog(LOG_ERR, "%s: ioctl (TIOCSCTTY): %m", username);
                down(2);
        }
        if (tcsetpgrp(fd, getpid()) < 0) {
                syslog(LOG_ERR, "%s: tcsetpgrp failed: %m", username);
                down(2);
        }
        printd(", ioctl\n");
        if (tcgetattr(fd, &t) < 0) {
                syslog(LOG_ERR, "%s: tcgetattr(%s): %m", username, devicename);
                down(2);
        }
        cfmakeraw(&t);
        switch (flowcontrol) {
        case FC_HW:
                t.c_cflag |= (CRTS_IFLOW|CCTS_OFLOW);
                break;
        case FC_NONE:
                t.c_cflag &= ~(CRTS_IFLOW|CCTS_OFLOW);
                break;
        }
        if (modem_control)
                t.c_cflag |= HUPCL;
        else
                t.c_cflag &= ~(HUPCL);
        t.c_cflag |= CLOCAL;    /* until modem commands passes */
        cfsetispeed(&t, speed);
        cfsetospeed(&t, speed);
        if (tcsetattr(fd, TCSAFLUSH, &t) < 0) {
                syslog(LOG_ERR, "%s: tcsetattr(%s): %m", username, devicename);
                down(2);
        }
        sleep(2);               /* wait for flakey line to settle */
        if (hup || terminate)
                goto restart;

        wfd = fdopen(fd, "w+");
        if (wfd == NULL) {
                syslog(LOG_ERR, "%s: can't fdopen %s: %m", username, devicename);
                down(2);
        }
        setbuf(wfd, NULL);

        if (diali > 0)
                dialerstring = dials[dialc++ % diali];
        if (dialerstring) {
                syslog(LOG_INFO, "%s: dialer string: %s\\r", username, dialerstring);
                fprintf(wfd, "%s\r", dialerstring);
        }
        printd("\n");

        fintimeout = time(NULL) + script_timeout;
        if (modem_control) {
                printd("waiting for carrier\n");
                while (time(NULL) < fintimeout && !carrier()) {
                        sleep(1);
                        if (hup || terminate)
                                goto restart;
                }
                if (!carrier())
                        goto restart;
                t.c_cflag &= ~(CLOCAL);
                if (tcsetattr(fd, TCSANOW, &t) < 0) {
                        syslog(LOG_ERR, "%s: tcsetattr(%s): %m", username, devicename);
                        down(2);
                }
                /* Only now we able to receive HUP on carrier drop! */
        }

        /*
         * Log in
         */
        printd("look for login: ");
        for (;;) {
                if (get_line(buf, BUFSIZ, fd, fintimeout) == 0 || hup || terminate)
                        goto restart;
                if (annex) {
                        if (bcmp(buf, annex, strlen(annex)) == 0) {
                                fprintf(wfd, "slip\r");
                                printd("Sent \"slip\"\n");
                                continue;
                        }
                        if (bcmp(&buf[1], "sername:", 8) == 0) {
                                fprintf(wfd, "%s\r", username);
                                printd("Sent login: %s\n", username);
                                continue;
                        }
                        if (bcmp(&buf[1], "assword:", 8) == 0) {
                                fprintf(wfd, "%s\r", password);
                                printd("Sent password: %s\n", password);
                                break;
                        }
                } else {
                        if (strstr(&buf[1], "ogin:") != NULL) {
                                fprintf(wfd, "%s\r", username);
                                printd("Sent login: %s\n", username);
                                continue;
                        }
                        if (strstr(&buf[1], "assword:") != NULL) {
                                fprintf(wfd, "%s\r", password);
                                printd("Sent password: %s\n", password);
                                break;
                        }
                }
        }

        sleep(5);       /* Wait until login completed */
        if (hup || terminate)
                goto restart;
        start_time = time(NULL);
        /*
         * Attach
         */
        printd("setd");
        disc = SLIPDISC;
        if (ioctl(fd, TIOCSETD, &disc) < 0) {
                syslog(LOG_ERR, "%s: ioctl (%s, TIOCSETD): %m",
                    username, devicename);
                down(2);
        }
        if (sl_unit >= 0 && ioctl(fd, SLIOCSUNIT, &sl_unit) < 0) {
                syslog(LOG_ERR, "%s: ioctl(SLIOCSUNIT): %m", username);
                down(2);
        }
        if (ioctl(fd, SLIOCGUNIT, &unitnum) < 0) {
                syslog(LOG_ERR, "%s: ioctl(SLIOCGUNIT): %m", username);
                down(2);
        }
        sprintf(unitname, "sl%d", unitnum);

        if (keepal > 0) {
                signal(SIGURG, sigurg);
                if (ioctl(fd, SLIOCSKEEPAL, &keepal) < 0) {
                        syslog(LOG_ERR, "%s: ioctl(SLIOCSKEEPAL): %m", username);
                        down(2);
                }
        }
        if (outfill > 0 && ioctl(fd, SLIOCSOUTFILL, &outfill) < 0) {
                syslog(LOG_ERR, "%s: ioctl(SLIOCSOUTFILL): %m", username);
                down(2);
        }

        sprintf(buf, "LINE=%d %s %s up",
                diali ? (dialc - 1) % diali : 0,
                upscript ? upscript : "/sbin/ifconfig" , unitname);
        system(buf);

        printd(", ready\n");
        if (!first)
                syslog(LOG_INFO, "%s: reconnected on %s (%d tries)", username, unitname, tries);
        else
                syslog(LOG_INFO, "%s: connected on %s", username, unitname);
        first = 0;
        tries = 0;
        logged_in = 1;
        while (hup == 0 && terminate == 0) {
                sigpause(0L);
                printd("sigpause return\n");
        }
        goto restart;
        return(0); /* not reached */
}

static void
sighup(int signo __unused)
{
        printd("hup\n");
        if (hup == 0 && logged_in)
                syslog(LOG_INFO, "%s: got hangup signal", username);
        hup = 1;
}

static void
sigurg(int signo __unused)
{
        printd("urg\n");
        if (hup == 0 && logged_in)
                syslog(LOG_INFO, "%s: got dead line signal", username);
        hup = 1;
}

static void
sigterm(int signo __unused)
{
        printd("terminate\n");
        if (terminate == 0 && logged_in)
                syslog(LOG_INFO, "%s: got terminate signal", username);
        terminate = 1;
}

static int
get_line(char *buf, int size, int this_fd, time_t fintimeout)
{
        int i;
        int ret;
        fd_set readfds;
        struct timeval tv;
        time_t timeout;

        size--;
        for (i = 0; i < size; i++) {
                if (hup || terminate)
                        return (0);
                if ((timeout = fintimeout - time(NULL)) <= 0)
                        goto tout;
                FD_ZERO(&readfds);
                FD_SET(fd, &readfds);
                tv.tv_sec = timeout;
                tv.tv_usec = 0;
                if ((ret = select(this_fd + 1, &readfds, NULL, NULL, &tv)) < 0) {
                        if (errno != EINTR)
                                syslog(LOG_ERR, "%s: get_line: select: %m", username);
                } else {
                        if (! ret) {
                        tout:
                                printd("get_line: timed out\n");
                                return (0);
                        }
                        if ((ret = read(this_fd, &buf[i], 1)) == 1) {
                                buf[i] &= 0177;
                                if (buf[i] == '\r' || buf[i] == '\0') {
                                        i--;
                                        continue;
                                }
                                if (buf[i] != '\n' && buf[i] != ':')
                                        continue;
                                buf[i + 1] = '\0';
                                printd("Got %d: %s", i + 1, buf);
                                return (i+1);
                        }
                        if (ret <= 0) {
                                if (ret < 0) {
                                        syslog(LOG_ERR, "%s: get_line: read: %m", username);
                                } else
                                        syslog(LOG_ERR, "%s: read returned 0", username);
                                buf[i] = '\0';
                                printd("returning %d after %d: %s\n", ret, i, buf);
                                return (0);
                        }
                }
        }
        return (0);
}

static int
carrier(void)
{
        int comstate;

        if (ioctl(fd, TIOCMGET, &comstate) < 0) {
                syslog(LOG_ERR, "%s: ioctl (%s, TIOCMGET): %m",
                    username, devicename);
                down(2);
        }
        return !!(comstate & TIOCM_CD);
}

static void
down(int code)
{
        if (fd > -1)
                close(fd);
        if (pfd)
                unlink(my_pidfile);
        if (uucp_lock && locked)
                uu_unlock(dvname);
        exit(code);
}

static void
usage(void)
{
        fprintf(stderr, "%s\n%s\n%s\n%s\n",  
"usage: startslip [-d] [-b speed] [-s string1 [-s string2 [...]]] [-h] [-l]",
"                 [-L] [-A annexname] [-U upscript] [-D downscript]",
"                 [-t script_timeout] [-W maxtries] [-w retry_pause]",
"                 [-K keepalive] [-O outfill] [-S unit] device user passwd");
        exit(1);
}