slattach.c

来自「Linux下网络相关工具源代码。」· C语言 代码 · 共 724 行 · 第 1/2 页

tty_set_state(struct termios *tty)
{
  if (ioctl(tty_fd, TCSETS, tty) < 0) {
	if (opt_q == 0) fprintf(stderr,
		"slattach: tty_set_state: %s\n", strerror(errno));
	return(-errno);
  }
  return(0);
}


/* Get the line discipline of a terminal line. */
static int
tty_get_disc(int *disc)
{
  if (ioctl(tty_fd, TIOCGETD, disc) < 0) {
	if (opt_q == 0) fprintf(stderr,
		"slattach: tty_get_disc: %s\n", strerror(errno));
	return(-errno);
  }
  return(0);
}


/* Set the line discipline of a terminal line. */
static int
tty_set_disc(int disc)
{
  if (disc == -1) disc = tty_sdisc;

  if (ioctl(tty_fd, TIOCSETD, &disc) < 0) {
	if (opt_q == 0) fprintf(stderr,
		"slattach: tty_set_disc(%d, %d): %s\n", tty_fd,
			disc, strerror(errno));
	return(-errno);
  }
  return(0);
}


/* Fetch the name of the network interface attached to this terminal. */
static int
tty_get_name(char *name)
{
  if (ioctl(tty_fd, SIOCGIFNAME, name) < 0) {
	if (opt_q == 0) fprintf(stderr,
		"slattach: tty_get_name: %s\n", strerror(errno));
	return(-errno);
  }
  return(0);
}


/* Hangup the line. */
static int
tty_hangup(void)
{
  struct termios tty;

  tty = tty_current;
  (void) tty_set_speed(&tty, "0");
  if (tty_set_state(&tty) < 0) {
	if (opt_q == 0) fprintf(stderr, _("slattach: tty_hangup(DROP): %s\n"), strerror(errno));
	return(-errno);
  }

  (void) sleep(1);

  if (tty_set_state(&tty_current) < 0) {
	if (opt_q == 0) fprintf(stderr, _("slattach: tty_hangup(RAISE): %s\n"), strerror(errno));
	return(-errno);
  }
  return(0);
}


/* Close down a terminal line. */
static int
tty_close(void)
{
  (void) tty_set_disc(tty_sdisc);
  (void) tty_hangup();
  (void) tty_lock(NULL, 0);
  return(0);
}


/* Open and initialize a terminal line. */
static int
tty_open(char *name, char *speed)
{
  char path[PATH_MAX];
  register char *sp;
  int fd;

  /* Try opening the TTY device. */
  if (name != NULL) {
	if ((sp = strrchr(name, '/')) != (char *)NULL) *sp++ = '\0';
	  else sp = name;
	sprintf(path, "/dev/%s", sp);
	if (tty_lock(sp, 1)) return(-1); /* can we lock the device? */
	if ((fd = open(path, O_RDWR)) < 0) {
		if (opt_q == 0) fprintf(stderr,
			"slattach: tty_open(%s, RW): %s\n",
					path, strerror(errno));
		return(-errno);
	}
	tty_fd = fd;
	if (opt_d) printf("slattach: tty_open: %s (%d) ", path, fd);
  } else {
	tty_fd = 0;
	sp = (char *)NULL;
  }

  /* Fetch the current state of the terminal. */
  if (tty_get_state(&tty_saved) < 0) {
	if (opt_q == 0) fprintf(stderr, _("slattach: tty_open: cannot get current state!\n"));
	return(-errno);
  }
  tty_current = tty_saved;

  /* Fetch the current line discipline of this terminal. */
  if (tty_get_disc(&tty_sdisc) < 0) {
	if (opt_q == 0) fprintf(stderr, _("slattach: tty_open: cannot get current line disc!\n"));
	return(-errno);
  } 
  tty_ldisc = tty_sdisc;

  /* Put this terminal line in a 8-bit transparent mode. */
  if (opt_m == 0) {
	if (tty_set_raw(&tty_current) < 0) {
		if (opt_q == 0) fprintf(stderr, _("slattach: tty_open: cannot set RAW mode!\n"));
		return(-errno);
	}

	/* Set the default speed if we need to. */
	if (speed != NULL) {
		if (tty_set_speed(&tty_current, speed) != 0) {
			if (opt_q == 0) fprintf(stderr, _("slattach: tty_open: cannot set %s bps!\n"),
						speed);
			return(-errno);
		}
	}

	/* Set up a completely 8-bit clean line. */
	if (tty_set_databits(&tty_current, "8") ||
	    tty_set_stopbits(&tty_current, "1") ||
	    tty_set_parity(&tty_current, "N")) {
		if (opt_q == 0) fprintf(stderr, _("slattach: tty_open: cannot set 8N1 mode!\n"));
		return(-errno);
  	}

	/* Set the new line mode. */
	if ((fd = tty_set_state(&tty_current)) < 0) return(fd);
  }

  /* OK, line is open.  Do we need to "silence" it? */
  (void) tty_nomesg(tty_fd);

  return(0);
}


/* Catch any signals. */
static void
sig_catch(int sig)
{
/*  (void) signal(sig, sig_catch); */
  tty_close();
  exit(0);
}


static void
usage(void)
{
  char *usage_msg = "Usage: slattach [-ehlLmnqv] "
#ifdef SIOCSKEEPALIVE
	  "[-k keepalive] "
#endif
#ifdef SIOCSOUTFILL
	  "[-o outfill] "
#endif
	  "[-c cmd] [-s speed] [-p protocol] tty | -\n"
	  "       slattach -V | --version\n";

  fprintf(stderr, usage_msg);
  exit(1);
}


static void 
version(void)
{
    printf("%s\n%s\n%s\n", Release, Version, Signature);
    exit(E_VERSION);
}


int
main(int argc, char *argv[])
{
  char path[128];
  char buff[128];
  char *speed = NULL;
  char *proto = DEF_PROTO;
  char *extcmd = (char *)0;
  struct hwtype *ht;
  char *sp;
  int s;
  static struct option longopts[] = {
    { "version", 0, NULL, 'V' },
    { NULL, 0, NULL, 0 }
  };

  strcpy(path, "");

  /* Scan command line for any arguments. */
  opterr = 0;
  while ((s = getopt_long(argc, argv, "c:ehlLmnp:qs:vdVk:o:", longopts, NULL)) != EOF) switch(s) {
	case 'c':
		extcmd = optarg;
		break;

	case 'e':
		opt_e = 1 - opt_e;
		break;

	case 'h':
		opt_h = 1 - opt_h;
		break;

#ifdef SIOCSKEEPALIVE
	case 'k':
		opt_k = atoi(optarg);
		break;
#endif

	case 'L':
		opt_L = 1 - opt_L;
		break;

	case 'l':
		opt_l = 1 - opt_l;
		break;

	case 'm':
		opt_m = 1 - opt_m;
		break;

	case 'n':
		opt_n = 1 - opt_n;
		break;

#ifdef SIOCSOUTFILL
	case 'o':
		opt_o = atoi(optarg);
		break;
#endif

	case 'p':
		proto = optarg;
		break;

	case 'q':
		opt_q = 1 - opt_q;
		break;

	case 's':
		speed = optarg;
		break;

	case 'd':
		opt_d = 1 - opt_d;
		break;

	case 'v':
		opt_v = 1 - opt_v;
		break;

        case 'V':
		version();
		/*NOTREACHED*/

	default:
		usage();
		/*NOTREACHED*/
  }
  
  activate_init();

  /* Check the protocol. */
  if ((ht = get_hwtype(proto)) == NULL && strcmp(proto, "tty")) {
	if (opt_q == 0) fprintf(stderr, _("slattach: unsupported protocol %s\n"), proto);
	return(2);
  }
  if (ht == NULL) opt_m++;

  /* Is a terminal given? */
  if (optind != (argc - 1)) usage();
  strncpy(path, argv[optind], 128);
  if (!strcmp(path, "-")) {
	opt_e = 1;
	sp = NULL;
	if (tty_open(NULL, speed) < 0) { return(3); }
  } else {
	if ((sp = strrchr(path, '/')) != NULL) *sp++ = '\0';
	  else sp = path;
	if (tty_open(sp, speed) < 0) { return(3); }
  }

  /* Start the correct protocol. */
  if (ht == NULL) {
	tty_sdisc = N_TTY;
	tty_close();
	return(0);
  }
  (*ht->activate)(tty_fd);
  if (opt_v == 1) {
	tty_get_name(buff);
	printf(_("%s started"), proto);
	if (sp != NULL) printf(_(" on %s"), sp);
	printf(_(" interface %s\n"), buff);
  }

  /* Configure keepalive and outfill. */
#ifdef SIOCSKEEPALIVE
  if (opt_k && (ioctl(tty_fd, SIOCSKEEPALIVE, &opt_k) < 0))
	  fprintf(stderr, "slattach: ioctl(SIOCSKEEPALIVE): %s\n", strerror(errno));
#endif
#ifdef SIOCSOUTFILL
  if (opt_o && (ioctl(tty_fd, SIOCSOUTFILL, &opt_o) < 0))
	  fprintf(stderr, "slattach: ioctl(SIOCSOUTFILL): %s\n", strerror(errno));
#endif

  (void) signal(SIGHUP, sig_catch);
  (void) signal(SIGINT, sig_catch);
  (void) signal(SIGQUIT, sig_catch);
  (void) signal(SIGTERM, sig_catch);

  /* Wait until we get killed if hanging on a terminal. */
  if (opt_e == 0) {
	while(1) {
		if(opt_h == 1) { /* hangup on carrier loss */
			int n = 0;

		        ioctl(tty_fd, TIOCMGET, &n);
			if(!(n & TIOCM_CAR))
				break;
			sleep(15);
		}
		else
			sleep(60);
	};

	tty_close();
	if(extcmd!=(char *)0) /* external command on exit */
		system(extcmd);
  }
  exit(0);
}