usr/src/sbin/startslip/startslip.c


/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1990, 1991 The Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)startslip.c 5.6 (Berkeley) %G%";
#endif /* not lint */

#include <sys/param.h>
#if BSD >= 199006
#define POSIX
#endif
#ifdef POSIX
#include <sys/termios.h>
#include <sys/ioctl.h>
#else
#include <sgtty.h>
#endif
#include <sys/socket.h>
#include <sys/syslog.h>
#include <netinet/in.h>
#include <net/if.h>
#include <net/if_slvar.h>
#include <netdb.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <signal.h>

#define DEFAULT_BAUD    B9600
int     speed = DEFAULT_BAUD;
int     hup;
int     logged_in;
int     wait_time = 60;         /* then back off */
#define MAXTRIES        6       /* w/60 sec and doubling, takes an hour */
#define PIDFILE         "/var/run/startslip.pid"

#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

main(argc, argv)
        int argc;
        char **argv;
{
        extern char *optarg;
        extern int optind;
        int ch, disc;
        int fd = -1;
        void sighup();
        FILE *wfd = NULL, *pfd;
        char *dialerstring = 0, buf[BUFSIZ];
        int first = 1, tries = 0;
        int pausefirst = 0;
        int pid;
#ifdef POSIX
        struct termios t;
#else
        struct sgttyb sgtty;
#endif

        while ((ch = getopt(argc, argv, "db:s:p:")) != EOF)
                switch (ch) {
                case 'd':
                        debug = 1;
                        break;
#ifdef POSIX
                case 'b':
                        speed = atoi(optarg);
                        break;
#endif
                case 'p':
                        pausefirst = atoi(optarg);
                        break;
                case 's':
                        dialerstring = optarg;
                        break;
                case '?':
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        if (argc != 3)
                usage();

        openlog("startslip", LOG_PID, LOG_DAEMON);

#if BSD <= 43
        if (debug == 0 && (fd = open("/dev/tty", 0)) >= 0) {
                ioctl(fd, TIOCNOTTY, 0);
                close(fd);
                fd = -1;
        }
#endif

        if (debug)
                setbuf(stdout, NULL);

        if (pfd = fopen(PIDFILE, "r")) {
                pid = 0;
                fscanf(pfd, "%d", &pid);
                if (pid > 0)
                        kill(pid, SIGUSR1);
                fclose(pfd);
        }
restart:
        logged_in = 0;
        if (++tries > MAXTRIES) {
                syslog(LOG_ERR, "exiting after %d tries\n", tries);
                /* ???
                if (first)
                */
                        exit(1);
        }

        /*
         * We may get a HUP below, when the parent (session leader/
         * controlling process) exits; ignore HUP until into new session.
         */
        signal(SIGHUP, SIG_IGN);
        hup = 0;
        if (fork() > 0) {
                if (pausefirst)
                        sleep(pausefirst);
                if (first)
                        printd("parent exit\n");
                exit(0);
        }
        pausefirst = 0;
#ifdef POSIX
        if (setsid() == -1)
                perror("setsid");
#endif
        pid = getpid();
        printd("restart: pid %d: ", pid);
        if (pfd = fopen(PIDFILE, "w")) {
                fprintf(pfd, "%d\n", pid);
                fclose(pfd);
        }
        if (wfd) {
                printd("fclose, ");
                fclose(wfd);
                wfd == NULL;
        }
        if (fd >= 0) {
                printd("close, ");
                close(fd);
                sleep(5);
        }
        printd("open");
        if ((fd = open(argv[0], O_RDWR)) < 0) {
                perror(argv[0]);
                syslog(LOG_ERR, "open %s: %m\n", argv[0]);
                if (first)
                        exit(1);
                else {
                        sleep(wait_time * tries);
                        goto restart;
                }
        }
        printd(" %d", fd);
#ifdef TIOCSCTTY
        if (ioctl(fd, TIOCSCTTY, 0) < 0)
                perror("ioctl (TIOCSCTTY)");
#endif
        signal(SIGHUP, sighup);
        if (debug) {
                if (ioctl(fd, TIOCGETD, &disc) < 0)
                        perror("ioctl(TIOCSETD)");
                printf(" (disc was %d)", disc);
        }
        disc = TTYDISC;
        if (ioctl(fd, TIOCSETD, &disc) < 0) {
                perror("ioctl(TIOCSETD)");
                syslog(LOG_ERR, "%s: ioctl (TIOCSETD 0): %m\n",
                    argv[0]);
        }
        printd(", ioctl");
#ifdef POSIX
        if (tcgetattr(fd, &t) < 0) {
                perror("tcgetattr");
                syslog(LOG_ERR, "%s: tcgetattr: %m\n", argv[0]);
                exit(2);
        }
        cfmakeraw(&t);
        t.c_iflag &= ~IMAXBEL;
        t.c_cflag |= CRTSCTS;
        cfsetspeed(&t, speed);
        if (tcsetattr(fd, TCSAFLUSH, &t) < 0) {
                perror("tcsetattr");
                syslog(LOG_ERR, "%s: tcsetattr: %m\n", argv[0]);
                if (first)
                        exit(2);
                else {
                        sleep(wait_time * tries);
                        goto restart;
                }
        }
#else
        if (ioctl(fd, TIOCGETP, &sgtty) < 0) {
                perror("ioctl (TIOCGETP)");
                syslog(LOG_ERR, "%s: ioctl (TIOCGETP): %m\n",
                    argv[0]);
                exit(2);
        }
        sgtty.sg_flags = RAW | ANYP;
        sgtty.sg_erase = sgtty.sg_kill = 0377;
        sgtty.sg_ispeed = sgtty.sg_ospeed = speed;
        if (ioctl(fd, TIOCSETP, &sgtty) < 0) {
                perror("ioctl (TIOCSETP)");
                syslog(LOG_ERR, "%s: ioctl (TIOCSETP): %m\n",
                    argv[0]);
                if (first)
                        exit(2);
                else {
                        sleep(wait_time * tries);
                        goto restart;
                }
        }
#endif
        sleep(2);               /* wait for flakey line to settle */
        if (hup)
                goto restart;

        wfd = fdopen(fd, "w+");
        if (wfd == NULL) {
                syslog(LOG_ERR, "can't fdopen slip line\n");
                exit(10);
        }
        setbuf(wfd, (char *)0);
        if (dialerstring) {
                printd(", send dialstring");
                fprintf(wfd, "%s\r", dialerstring);
        } else
                putc('\r', wfd);
        printd("\n");

        /*
         * Log in
         */
        printd("look for login: ");
        for (;;) {
                if (getline(buf, BUFSIZ, fd) == 0 || hup) {
                        sleep(wait_time * tries);
                        goto restart;
                }
                if (bcmp(&buf[1], "ogin:", 5) == 0) {
                        fprintf(wfd, "%s\r", argv[1]);
                        printd("Sent login: %s\n", argv[1]);
                        continue;
                }
                if (bcmp(&buf[1], "assword:", 8) == 0) {
                        fprintf(wfd, "%s\r", argv[2]);
                        printd("Sent password: %s\n", argv[2]);
                        break;
                }
        }

        /*
         * Attach
         */
        printd("setd");
        disc = SLIPDISC;
        if (ioctl(fd, TIOCSETD, &disc) < 0) {
                perror("ioctl(TIOCSETD)");
                syslog(LOG_ERR, "%s: ioctl (TIOCSETD SLIP): %m\n",
                    argv[0]);
                exit(1);
        }
        if (first && debug == 0) {
                close(0);
                close(1);
                close(2);
                (void) open("/dev/null", O_RDWR);
                (void) dup2(0, 1);
                (void) dup2(0, 2);
        }
        (void) system("ifconfig sl0 up");
        printd(", ready\n");
        if (!first)
                syslog(LOG_INFO, "reconnected (%d tries).\n", tries);
        first = 0;
        tries = 0;
        logged_in = 1;
        while (hup == 0) {
                sigpause(0L);
                printd("sigpause return\n");
        }
        goto restart;
}

void
sighup()
{

        printd("hup\n");
        if (hup == 0 && logged_in)
                syslog(LOG_INFO, "hangup signal\n");
        hup = 1;
}

getline(buf, size, fd)
        char *buf;
        int size, fd;
{
        register int i;
        int ret;

        size--;
        for (i = 0; i < size; i++) {
                if (hup)
                        return (0);
                if ((ret = read(fd, &buf[i], 1)) == 1) {
                        buf[i] &= 0177;
                        if (buf[i] == '\r' || buf[i] == '\0')
                                buf[i] = '\n';
                        if (buf[i] != '\n' && buf[i] != ':')
                                continue;
                        buf[i + 1] = '\0';
                        printd("Got %d: \"%s\"\n", i + 1, buf);
                        return (i+1);
                }
                if (ret <= 0) {
                        if (ret < 0)
                                perror("getline: read");
                        else
                                fprintf(stderr, "read returned 0\n");
                        buf[i] = '\0';
                        printd("returning 0 after %d: \"%s\"\n", i, buf);
                        return (0);
                }
        }
        return (0);
}

usage()
{
        fprintf(stderr, "usage: startslip [-d] [-s string] dev user passwd\n");
        exit(1);
}