[unix-history] / sbin / slattach / slattach.c

/*
 * Copyright (c) 1988 Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Rick Adams.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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.
 */

/*
 * Hacks to support "-a|c|n" flags on the command line which enable VJ
 * header compresion and disable ICMP.
 * If this is good all rights go to B & L Jolitz, otherwise send your
 * comments to Reagan (/dev/null).
 *
 * nerd@percival.rain.com (Michael Galassi) 92.09.03
 *
 * Hacked to change from sgtty to POSIX termio style serial line control
 * and added flag to enable cts/rts style flow control.
 *
 * blymn@awadi.com.au (Brett Lymn) 93.04.04
 *
 * Put slattach in it's own process group so it can't be killed
 * accidentally. Close the connection on SIGHUP and SIGINT. Write a
 * syslog entry upon opening and closing the connection.  Rich Murphey
 * and Brad Huntting.
 *
 * Add '-r command' option: runs 'command' upon recieving SIGHUP
 * resulting from loss of carrier.  Log any errors after forking.
 * Rich 8/13/93
 *
 * This version of slattach includes many changes by David Greenman, Brian
 * Smith, Chris Bradley, and me (Michael Galassi).  None of them are
 * represented as functional anywhere outside of RAINet though they do work
 * for us.  Documentation is limited to the usage message for now.  If you
 * make improovments please pass them back.
 *
 * Added '-u UCMD' which runs 'UCMD <old> <new>' whenever the slip
 * unit number changes where <old> and <new> are the old and new unit
 * numbers, respectively.  Also added the '-z' option which forces
 * invocation of the redial command (-r CMD) upon startup regardless
 * of whether the com driver claims (sometimes mistakenly) that
 * carrier is present. Also added '-e ECMD' which runs ECMD before
 * exiting.
 *
 * marc@escargot.rain.com (Marc Frajola) 93/09/10
 *
 * Minor fixes to allow passive SLIP links to work (connections with
 * modem control that do not have an associated dial command). Added
 * code to re-check for carrier after dial command has been executed.
 * Added SIGTERM handler to properly handle normal kill signals. Fixed
 * bug in logic that caused message about no -u command to be logged
 * even when -u was specified and the sl number changes. Tried to get
 * rid of redundant syslog()'s to minimize console log output. Improved
 * logging of improper command line options or number of command
 * arguments. Removed spurious newline characters from syslog() calls.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1988 Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
/*static char sccsid[] = "from: @(#)slattach.c	4.6 (Berkeley) 6/1/90";*/
static char rcsid[] = "$Id";
#endif /* not lint */

#include <sys/param.h>
#include <sys/ioctl.h>
#include <termios.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <net/if.h>
#include <net/if_slvar.h>
#include <netdb.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <paths.h>
#include <syslog.h>
#include <signal.h>
#include <strings.h>

extern int errno;
extern char *sys_errlist[];

#define DEFAULT_BAUD	9600

void	sighup_handler();	/* SIGHUP handler */
void	sigint_handler();	/* SIGINT handler */
void	sigterm_handler();	/* SIGTERM handler */
void	exit_handler(int ret);	/* run exit_cmd iff specified upon exit. */
void	setup_line();		/* configure slip line */
void	attach_line();		/* switch to slip line discipline */

int	fd = -1;
char	*dev = (char *)0;
int	slipdisc = SLIPDISC;
int	ttydisc = TTYDISC;
int	flow_control = 0;	/* non-zero to enable hardware flow control. */
int	modem_control = 0;	/* non-zero iff we watch carrier. */
int	comstate;		/* TIOCMGET current state of serial driver */
int	redial_on_startup = 0;	/* iff non-zero execute redial_cmd on startup */
int	speed = DEFAULT_BAUD;
int	slflags = 0;		/* compression flags */
int	unit = -1;		/* slip device unit number */
int	foreground = 0;
FILE	*console;

char	devname[32];
char	hostname[MAXHOSTNAMELEN];
char	*redial_cmd = 0;	/* command to exec upon shutdown. */
char	*config_cmd = 0;	/* command to exec if slip unit changes. */
char	*exit_cmd = 0;		/* command to exec before exiting. */
char	string[100];

static char usage_str[] = "\
usage: %s [-acfhlnz] [-e command] [-r command] [-s speed] [-u command] device\n\
  -a      -- autoenable VJ compression\n\
  -c      -- enable VJ compression\n\
  -e ECMD -- run ECMD before exiting\n\
  -f      -- run in foreground (don't detach from controlling tty)\n\
  -h      -- turn on cts/rts style flow control\n\
  -l      -- disable modem control (CLOCAL) and ignore carrier detect\n\
  -n      -- throw out ICMP packets\n\
  -r RCMD -- run RCMD upon loss of carrier\n\
  -s #    -- set baud rate (default 9600)\n\
  -u UCMD -- run 'UCMD <old sl#> <new sl#>' before switch to slip discipline\n\
  -z      -- run RCMD upon startup irrespective of carrier\n";

int main(int argc, char **argv)
{
	int option;
	char name[32];
	extern char *optarg;
	extern int optind;

	while ((option = getopt(argc, argv, "ace:fhlnr:s:u:z")) != EOF) {
		switch (option) {
		case 'a':
			slflags |= SC_AUTOCOMP;
			slflags &= ~SC_COMPRESS;
			break;
		case 'c':
			slflags |= SC_COMPRESS;
			slflags &= ~SC_AUTOCOMP;
			break;
		case 'e':
			exit_cmd = (char*) strdup (optarg);
			break;
		case 'f':
			foreground = 1;
			break;
		case 'h':
			flow_control |= CRTSCTS;
			break;
		case 'l':
			modem_control |= CLOCAL;
			break;
		case 'n':
			slflags |= SC_NOICMP;
			break;
		case 'r':
			redial_cmd = (char*) strdup (optarg);
			break;
		case 's':
			speed = atoi(optarg);
			break;
		case 'u':
			config_cmd = (char*) strdup (optarg);
			break;
		case 'z':
			redial_on_startup = 1;
			break;
		default:
			fprintf(stderr, "%s: Invalid option -- '%c'\n",
			  option);
		case '?':
			fprintf(stderr, usage_str, argv[0]);
			exit_handler(1);
		}
	}

	if (optind == argc - 1)
		dev = argv[optind];

	if (optind < (argc - 1)) {
	    fprintf(stderr, "%s: Too many args, first='%s'\n",
	      argv[0], argv[optind]);
	}
	if (optind > (argc - 1)) {
	    fprintf(stderr, "%s: Not enough args\n", argv[0]);
	}
	if (dev == (char *)0) {
		fprintf(stderr, usage_str, argv[0]);
		exit_handler(2);
	}
	if (strncmp(_PATH_DEV, dev, sizeof(_PATH_DEV) - 1)) {
		strcpy(devname, _PATH_DEV);
		strcat(devname, "/");
		strncat(devname, dev, 10);
		dev = devname;
	}

	if (!foreground)
		daemon(0,0);	/* fork, setsid, chdir /, and close std*. */

	/* Note: daemon() closes stderr, so log errors from here on. */
	(void)sprintf(name,"slattach[%d]", getpid());
	openlog(name,LOG_CONS,LOG_DAEMON);

	if ((fd = open(dev, O_RDWR | O_NONBLOCK)) < 0) {
                syslog(LOG_ERR, "open(%s): %m", dev);
		exit_handler(1);
	}
	/* acquire the serial line as a controling terminal. */
	if (ioctl(fd, TIOCSCTTY, 0) < 0)
		syslog(LOG_NOTICE,"ioctl(TIOCSCTTY) failed: %s: %m");
	/* Make us the foreground process group associated with the
	   slip line which is our controlling terminal. */
	if (tcsetpgrp(fd, getpid()) < 0)
		syslog(LOG_NOTICE,"tcsetpgrp failed: %s: %m");
	/* upon INT log a timestamp and exit.  */
	if ((int)signal(SIGINT,sigint_handler) < 0)
		syslog(LOG_NOTICE,"cannot install SIGINT handler: %s: %m");
	/* upon TERM log a timestamp and exit.  */
	if ((int)signal(SIGTERM,sigterm_handler) < 0)
		syslog(LOG_NOTICE,"cannot install SIGTERM handler: %s: %m");
	/* upon HUP redial and reconnect.  */
	if ((int)signal(SIGHUP,sighup_handler) < 0)
		syslog(LOG_NOTICE,"cannot install SIGHUP handler: %s: %m");

	setup_line();

	if (redial_on_startup)
		sighup_handler();
	else
		attach_line();
	if (!(modem_control & CLOCAL)) {
		ioctl(fd, TIOCMGET, &comstate);
		if (!(comstate & TIOCM_CD)) { /* check for carrier */
			/* force a redial if no carrier */
			kill (getpid(), SIGHUP);
		}
	}
	for (;;) {
		sigset_t mask = 0;
		sigsuspend(&mask);
	}
}

void setup_line()
{
	struct termios tty;

	tty.c_lflag = tty.c_iflag = tty.c_oflag = 0;
	tty.c_cflag = CREAD | CS8 | flow_control | modem_control;
	tty.c_ispeed = tty.c_ospeed = speed;
	/* set the line speed and flow control */
	if (tcsetattr(fd, TCSAFLUSH, &tty) < 0) {
                syslog(LOG_ERR, "tcsetattr(TCSAFLUSH): %m");
		exit_handler(1);
	}
	/* set data terminal ready */
	if (ioctl(fd, TIOCSDTR) < 0) {
                syslog(LOG_ERR, "ioctl(TIOCSDTR): %m");
                exit_handler(1);
        }
	/* Switch to slip line discipline. */
	if (ioctl(fd, TIOCSETD, &slipdisc) < 0) {
                syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
		exit_handler(1);
	}
	/* Assert any compression or no-icmp flags. */
	if (ioctl(fd, SLIOCSFLAGS, &slflags) < 0) {
                syslog(LOG_ERR, "ioctl(SLIOCSFLAGS): %m");
		exit_handler(1);
	}
}

/* switch to slip line discipline and configure the network. */
void attach_line()
{
	int new_unit;

	/* find out what unit number we were assigned */
        if (ioctl(fd, SLIOCGUNIT, (caddr_t)&new_unit) < 0) {
                syslog(LOG_ERR, "ioctl(SLIOCGUNIT): %m");
                exit_handler(1);
        }
	/* don't compare unit numbers if this is the first time to attach. */
	if (unit < 0)
		unit = new_unit;
	/* iff the unit number changes either invoke config_cmd or punt. */
	if (config_cmd) {
		char *s;
		s = (char*) malloc(strlen(config_cmd) + 32);
		sprintf (s, "%s %d %d", config_cmd, unit, new_unit);
		syslog(LOG_NOTICE, "Configuring %s (sl%d):", dev, unit);
		syslog(LOG_NOTICE, "  '%s'", s);
		system(s);
		free (s);
		unit = new_unit;
	} else {
		if (new_unit != unit) {
			syslog(LOG_ERR, "slip unit changed from sl%d to sl%d, but no -u CMD was specified!");
			exit_handler(1);
		}
		syslog(LOG_NOTICE,"sl%d connected to %s at %d baud",unit,dev,speed);
	}
}

/* Signal handler for SIGHUP when carrier is dropped. */
void sighup_handler()
{
again:
	/* reset discipline */
	if (ioctl(fd, TIOCSETD, &ttydisc) < 0) {
		syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
		exit_handler(1);
	}
	/* invoke a shell for redial_cmd or punt. */
	if (redial_cmd) {
		syslog(LOG_NOTICE,"SIGHUP on %s (sl%d); running %s",
		       dev,unit,redial_cmd);
		system(redial_cmd);
		/* Now check again for carrier (dial command is done): */
		if (!(modem_control & CLOCAL)) {
			ioctl(fd, TIOCMGET, &comstate);
			if (!(comstate & TIOCM_CD)) { /* check for carrier */
				/* force a redial if no carrier */
				goto again;
			}
		}
	} else {
		/*
		 * No redial command.
		 *
		 * If modem control, just wait for carrier before
		 * falling through to setup_line() and attach_line().
		 * If no modem control, just fall through immediately.
		 */
		if (!(modem_control & CLOCAL)) {
		    int carrier = 0;

		    syslog(LOG_NOTICE, "Waiting for carrier on %s (sl%d)",
		      dev, unit);

		    /* Now wait for carrier before attaching line: */
		    while (! carrier) {
			/*
			 * Don't burn the CPU checking for carrier;
			 * carrier must be polled since there is no
			 * way to have a signal sent when carrier
			 * goes high (SIGHUP can only be sent when
			 * carrier is dropped); so add space between
			 * checks for carrier:
			 */
			sleep(2);

			/* Check for carrier present on tty port: */
			ioctl(fd, TIOCMGET, &comstate);
			if (comstate & TIOCM_CD) {
			    carrier = 1;
			}
		    }

		    syslog(LOG_NOTICE, "Carrier now present on %s (sl%d)",
		      dev, unit);
		}
	}
	setup_line();
	attach_line();
}
/* Signal handler for SIGINT.  We just log and exit. */
void sigint_handler()
{
	syslog(LOG_NOTICE,"sl%d on %s caught SIGINT, exiting.",unit,dev);
	exit_handler(0);
}
/* Signal handler for SIGTERM.  We just log and exit. */
void sigterm_handler()
{
	syslog(LOG_NOTICE,"SIGTERM on %s (sl%d); exiting",dev,unit);
	exit_handler(0);
}
/* Run config_cmd if specified before exiting. */
void exit_handler(int ret)
{
	/*
	 * First close the slip line in case exit_cmd wants it (like to hang
	 * up a modem or something).
	 */
	if (fd != -1)
		close(fd);
	/* invoke a shell for exit_cmd. */
	if (exit_cmd) {
		syslog(LOG_NOTICE,"exiting after running %s", exit_cmd);
		system(exit_cmd);
	}
	exit(ret);
}

/* local variables: */
/* c-indent-level: 8 */
/* c-argdecl-indent: 0 */
/* c-label-offset: -8 */
/* c-continued-statement-offset: 8 */
/* c-brace-offset: 0 */
/* comment-column: 32 */
/* end: */
Commit	Line	Data
15637ed4 RG	1	/*
	2	* Copyright (c) 1988 Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* This code is derived from software contributed to Berkeley by
	6	* Rick Adams.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
	16	* 3. All advertising materials mentioning features or use of this software
	17	* must display the following acknowledgement:
	18	* This product includes software developed by the University of
	19	* California, Berkeley and its contributors.
	20	* 4. Neither the name of the University nor the names of its contributors
	21	* may be used to endorse or promote products derived from this software
	22	* without specific prior written permission.
	23	*
	24	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	25	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	26	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	27	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	28	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	29	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	30	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	31	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	32	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	33	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	34	* SUCH DAMAGE.
	35	*/
	36
78ed81a3	37	/*
	38	* Hacks to support "-a\|c\|n" flags on the command line which enable VJ
	39	* header compresion and disable ICMP.
	40	* If this is good all rights go to B & L Jolitz, otherwise send your
	41	* comments to Reagan (/dev/null).
	42	*
	43	* nerd@percival.rain.com (Michael Galassi) 92.09.03
	44	*
	45	* Hacked to change from sgtty to POSIX termio style serial line control
	46	* and added flag to enable cts/rts style flow control.
	47	*
	48	* blymn@awadi.com.au (Brett Lymn) 93.04.04
	49	*
	50	* Put slattach in it's own process group so it can't be killed
	51	* accidentally. Close the connection on SIGHUP and SIGINT. Write a
	52	* syslog entry upon opening and closing the connection. Rich Murphey
	53	* and Brad Huntting.
	54	*
	55	* Add '-r command' option: runs 'command' upon recieving SIGHUP
	56	* resulting from loss of carrier. Log any errors after forking.
	57	* Rich 8/13/93
	58	*
	59	* This version of slattach includes many changes by David Greenman, Brian
	60	* Smith, Chris Bradley, and me (Michael Galassi). None of them are
	61	* represented as functional anywhere outside of RAINet though they do work
	62	* for us. Documentation is limited to the usage message for now. If you
	63	* make improovments please pass them back.
	64	*
	65	* Added '-u UCMD' which runs 'UCMD <old> <new>' whenever the slip
	66	* unit number changes where <old> and <new> are the old and new unit
	67	* numbers, respectively. Also added the '-z' option which forces
	68	* invocation of the redial command (-r CMD) upon startup regardless
	69	* of whether the com driver claims (sometimes mistakenly) that
	70	* carrier is present. Also added '-e ECMD' which runs ECMD before
	71	* exiting.
	72	*
	73	* marc@escargot.rain.com (Marc Frajola) 93/09/10
	74	*
	75	* Minor fixes to allow passive SLIP links to work (connections with
	76	* modem control that do not have an associated dial command). Added
	77	* code to re-check for carrier after dial command has been executed.
	78	* Added SIGTERM handler to properly handle normal kill signals. Fixed
	79	* bug in logic that caused message about no -u command to be logged
	80	* even when -u was specified and the sl number changes. Tried to get
	81	* rid of redundant syslog()'s to minimize console log output. Improved
	82	* logging of improper command line options or number of command
	83	* arguments. Removed spurious newline characters from syslog() calls.
	84	*/
	85
15637ed4 RG	86	#ifndef lint
	87	char copyright[] =
	88	"@(#) Copyright (c) 1988 Regents of the University of California.\n\
	89	All rights reserved.\n";
	90	#endif /* not lint */
	91
	92	#ifndef lint
78ed81a3	93	/static char sccsid[] = "from: @(#)slattach.c 4.6 (Berkeley) 6/1/90";/
78ed81a3	94	static char rcsid[] = "$Id";
15637ed4 RG	95	#endif /* not lint */
	96
	97	#include <sys/param.h>
78ed81a3	98	#include <sys/ioctl.h>
78ed81a3	99	#include <termios.h>
15637ed4 RG	100	#include <sys/socket.h>
	101	#include <netinet/in.h>
	102	#include <net/if.h>
78ed81a3	103	#include <net/if_slvar.h>
15637ed4 RG	104	#include <netdb.h>
15637ed4 RG	105	#include <fcntl.h>
78ed81a3	106	#include <stdlib.h>
15637ed4	107	#include <stdio.h>
78ed81a3	108	#include <unistd.h>
15637ed4	109	#include <paths.h>
78ed81a3	110	#include <syslog.h>
	111	#include <signal.h>
	112	#include <strings.h>
	113
	114	extern int errno;
	115	extern char *sys_errlist[];
15637ed4 RG	116
15637ed4 RG	117	#define DEFAULT_BAUD 9600
78ed81a3	118
	119	void sighup_handler(); /* SIGHUP handler */
	120	void sigint_handler(); /* SIGINT handler */
	121	void sigterm_handler(); /* SIGTERM handler */
	122	void exit_handler(int ret); /* run exit_cmd iff specified upon exit. */
	123	void setup_line(); /* configure slip line */
	124	void attach_line(); /* switch to slip line discipline */
	125
	126	int fd = -1;
	127	char dev = (char )0;
15637ed4	128	int slipdisc = SLIPDISC;
78ed81a3	129	int ttydisc = TTYDISC;
	130	int flow_control = 0; /* non-zero to enable hardware flow control. */
	131	int modem_control = 0; /* non-zero iff we watch carrier. */
	132	int comstate; /* TIOCMGET current state of serial driver */
	133	int redial_on_startup = 0; /* iff non-zero execute redial_cmd on startup */
	134	int speed = DEFAULT_BAUD;
	135	int slflags = 0; /* compression flags */
	136	int unit = -1; /* slip device unit number */
	137	int foreground = 0;
	138	FILE *console;
15637ed4 RG	139
	140	char devname[32];
	141	char hostname[MAXHOSTNAMELEN];
78ed81a3	142	char redial_cmd = 0; / command to exec upon shutdown. */
	143	char config_cmd = 0; / command to exec if slip unit changes. */
	144	char exit_cmd = 0; / command to exec before exiting. */
	145	char string[100];
	146
	147	static char usage_str[] = "\
	148	usage: %s [-acfhlnz] [-e command] [-r command] [-s speed] [-u command] device\n\
	149	-a -- autoenable VJ compression\n\
	150	-c -- enable VJ compression\n\
	151	-e ECMD -- run ECMD before exiting\n\
	152	-f -- run in foreground (don't detach from controlling tty)\n\
	153	-h -- turn on cts/rts style flow control\n\
	154	-l -- disable modem control (CLOCAL) and ignore carrier detect\n\
	155	-n -- throw out ICMP packets\n\
	156	-r RCMD -- run RCMD upon loss of carrier\n\
	157	-s # -- set baud rate (default 9600)\n\
	158	-u UCMD -- run 'UCMD <old sl#> <new sl#>' before switch to slip discipline\n\
	159	-z -- run RCMD upon startup irrespective of carrier\n";
15637ed4	160
78ed81a3	161	int main(int argc, char **argv)
15637ed4	162	{
78ed81a3	163	int option;
	164	char name[32];
	165	extern char *optarg;
	166	extern int optind;
	167
	168	while ((option = getopt(argc, argv, "ace:fhlnr:s:u:z")) != EOF) {
	169	switch (option) {
	170	case 'a':
	171	slflags \|= SC_AUTOCOMP;
	172	slflags &= ~SC_COMPRESS;
	173	break;
	174	case 'c':
	175	slflags \|= SC_COMPRESS;
	176	slflags &= ~SC_AUTOCOMP;
	177	break;
	178	case 'e':
	179	exit_cmd = (char*) strdup (optarg);
	180	break;
	181	case 'f':
	182	foreground = 1;
	183	break;
	184	case 'h':
	185	flow_control \|= CRTSCTS;
	186	break;
	187	case 'l':
	188	modem_control \|= CLOCAL;
	189	break;
	190	case 'n':
	191	slflags \|= SC_NOICMP;
	192	break;
	193	case 'r':
	194	redial_cmd = (char*) strdup (optarg);
	195	break;
	196	case 's':
	197	speed = atoi(optarg);
	198	break;
	199	case 'u':
	200	config_cmd = (char*) strdup (optarg);
	201	break;
	202	case 'z':
	203	redial_on_startup = 1;
	204	break;
	205	default:
	206	fprintf(stderr, "%s: Invalid option -- '%c'\n",
	207	option);
	208	case '?':
	209	fprintf(stderr, usage_str, argv[0]);
	210	exit_handler(1);
	211	}
	212	}
	213
	214	if (optind == argc - 1)
	215	dev = argv[optind];
	216
	217	if (optind < (argc - 1)) {
	218	fprintf(stderr, "%s: Too many args, first='%s'\n",
	219	argv[0], argv[optind]);
	220	}
	221	if (optind > (argc - 1)) {
	222	fprintf(stderr, "%s: Not enough args\n", argv[0]);
15637ed4	223	}
78ed81a3	224	if (dev == (char *)0) {
	225	fprintf(stderr, usage_str, argv[0]);
	226	exit_handler(2);
15637ed4 RG	227	}
15637ed4 RG	228	if (strncmp(_PATH_DEV, dev, sizeof(_PATH_DEV) - 1)) {
78ed81a3	229	strcpy(devname, _PATH_DEV);
	230	strcat(devname, "/");
	231	strncat(devname, dev, 10);
15637ed4 RG	232	dev = devname;
15637ed4 RG	233	}
78ed81a3	234
	235	if (!foreground)
	236	daemon(0,0); /* fork, setsid, chdir /, and close std. /
	237
	238	/* Note: daemon() closes stderr, so log errors from here on. */
	239	(void)sprintf(name,"slattach[%d]", getpid());
	240	openlog(name,LOG_CONS,LOG_DAEMON);
	241
	242	if ((fd = open(dev, O_RDWR \| O_NONBLOCK)) < 0) {
	243	syslog(LOG_ERR, "open(%s): %m", dev);
	244	exit_handler(1);
	245	}
	246	/* acquire the serial line as a controling terminal. */
	247	if (ioctl(fd, TIOCSCTTY, 0) < 0)
	248	syslog(LOG_NOTICE,"ioctl(TIOCSCTTY) failed: %s: %m");
	249	/* Make us the foreground process group associated with the
	250	slip line which is our controlling terminal. */
	251	if (tcsetpgrp(fd, getpid()) < 0)
	252	syslog(LOG_NOTICE,"tcsetpgrp failed: %s: %m");
	253	/* upon INT log a timestamp and exit. */
	254	if ((int)signal(SIGINT,sigint_handler) < 0)
	255	syslog(LOG_NOTICE,"cannot install SIGINT handler: %s: %m");
	256	/* upon TERM log a timestamp and exit. */
	257	if ((int)signal(SIGTERM,sigterm_handler) < 0)
	258	syslog(LOG_NOTICE,"cannot install SIGTERM handler: %s: %m");
	259	/* upon HUP redial and reconnect. */
	260	if ((int)signal(SIGHUP,sighup_handler) < 0)
	261	syslog(LOG_NOTICE,"cannot install SIGHUP handler: %s: %m");
	262
	263	setup_line();
	264
	265	if (redial_on_startup)
	266	sighup_handler();
	267	else
	268	attach_line();
	269	if (!(modem_control & CLOCAL)) {
	270	ioctl(fd, TIOCMGET, &comstate);
	271	if (!(comstate & TIOCM_CD)) { /* check for carrier */
	272	/* force a redial if no carrier */
	273	kill (getpid(), SIGHUP);
	274	}
15637ed4	275	}
78ed81a3	276	for (;;) {
	277	sigset_t mask = 0;
	278	sigsuspend(&mask);
	279	}
	280	}
	281
	282	void setup_line()
	283	{
	284	struct termios tty;
	285
	286	tty.c_lflag = tty.c_iflag = tty.c_oflag = 0;
	287	tty.c_cflag = CREAD \| CS8 \| flow_control \| modem_control;
	288	tty.c_ispeed = tty.c_ospeed = speed;
	289	/* set the line speed and flow control */
	290	if (tcsetattr(fd, TCSAFLUSH, &tty) < 0) {
	291	syslog(LOG_ERR, "tcsetattr(TCSAFLUSH): %m");
	292	exit_handler(1);
15637ed4	293	}
78ed81a3	294	/* set data terminal ready */
	295	if (ioctl(fd, TIOCSDTR) < 0) {
	296	syslog(LOG_ERR, "ioctl(TIOCSDTR): %m");
	297	exit_handler(1);
	298	}
	299	/* Switch to slip line discipline. */
15637ed4	300	if (ioctl(fd, TIOCSETD, &slipdisc) < 0) {
78ed81a3	301	syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
78ed81a3	302	exit_handler(1);
15637ed4	303	}
78ed81a3	304	/* Assert any compression or no-icmp flags. */
	305	if (ioctl(fd, SLIOCSFLAGS, &slflags) < 0) {
	306	syslog(LOG_ERR, "ioctl(SLIOCSFLAGS): %m");
	307	exit_handler(1);
	308	}
	309	}
	310
	311	/* switch to slip line discipline and configure the network. */
	312	void attach_line()
	313	{
	314	int new_unit;
15637ed4	315
78ed81a3	316	/* find out what unit number we were assigned */
	317	if (ioctl(fd, SLIOCGUNIT, (caddr_t)&new_unit) < 0) {
	318	syslog(LOG_ERR, "ioctl(SLIOCGUNIT): %m");
	319	exit_handler(1);
	320	}
	321	/* don't compare unit numbers if this is the first time to attach. */
	322	if (unit < 0)
	323	unit = new_unit;
	324	/* iff the unit number changes either invoke config_cmd or punt. */
	325	if (config_cmd) {
	326	char *s;
	327	s = (char*) malloc(strlen(config_cmd) + 32);
	328	sprintf (s, "%s %d %d", config_cmd, unit, new_unit);
	329	syslog(LOG_NOTICE, "Configuring %s (sl%d):", dev, unit);
	330	syslog(LOG_NOTICE, " '%s'", s);
	331	system(s);
	332	free (s);
	333	unit = new_unit;
	334	} else {
	335	if (new_unit != unit) {
	336	syslog(LOG_ERR, "slip unit changed from sl%d to sl%d, but no -u CMD was specified!");
	337	exit_handler(1);
	338	}
	339	syslog(LOG_NOTICE,"sl%d connected to %s at %d baud",unit,dev,speed);
	340	}
15637ed4 RG	341	}
15637ed4 RG	342
78ed81a3	343	/* Signal handler for SIGHUP when carrier is dropped. */
78ed81a3	344	void sighup_handler()
15637ed4	345	{
78ed81a3	346	again:
	347	/* reset discipline */
	348	if (ioctl(fd, TIOCSETD, &ttydisc) < 0) {
	349	syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
	350	exit_handler(1);
	351	}
	352	/* invoke a shell for redial_cmd or punt. */
	353	if (redial_cmd) {
	354	syslog(LOG_NOTICE,"SIGHUP on %s (sl%d); running %s",
	355	dev,unit,redial_cmd);
	356	system(redial_cmd);
	357	/* Now check again for carrier (dial command is done): */
	358	if (!(modem_control & CLOCAL)) {
	359	ioctl(fd, TIOCMGET, &comstate);
	360	if (!(comstate & TIOCM_CD)) { /* check for carrier */
	361	/* force a redial if no carrier */
	362	goto again;
	363	}
	364	}
	365	} else {
	366	/*
	367	* No redial command.
	368	*
	369	* If modem control, just wait for carrier before
	370	* falling through to setup_line() and attach_line().
	371	* If no modem control, just fall through immediately.
	372	*/
	373	if (!(modem_control & CLOCAL)) {
	374	int carrier = 0;
15637ed4	375
78ed81a3	376	syslog(LOG_NOTICE, "Waiting for carrier on %s (sl%d)",
	377	dev, unit);
	378
	379	/* Now wait for carrier before attaching line: */
	380	while (! carrier) {
	381	/*
	382	* Don't burn the CPU checking for carrier;
	383	* carrier must be polled since there is no
	384	* way to have a signal sent when carrier
	385	* goes high (SIGHUP can only be sent when
	386	* carrier is dropped); so add space between
	387	* checks for carrier:
	388	*/
	389	sleep(2);
	390
	391	/* Check for carrier present on tty port: */
	392	ioctl(fd, TIOCMGET, &comstate);
	393	if (comstate & TIOCM_CD) {
	394	carrier = 1;
	395	}
	396	}
	397
	398	syslog(LOG_NOTICE, "Carrier now present on %s (sl%d)",
	399	dev, unit);
	400	}
	401	}
	402	setup_line();
	403	attach_line();
	404	}
	405	/* Signal handler for SIGINT. We just log and exit. */
	406	void sigint_handler()
	407	{
	408	syslog(LOG_NOTICE,"sl%d on %s caught SIGINT, exiting.",unit,dev);
	409	exit_handler(0);
15637ed4	410	}
78ed81a3	411	/* Signal handler for SIGTERM. We just log and exit. */
	412	void sigterm_handler()
	413	{
	414	syslog(LOG_NOTICE,"SIGTERM on %s (sl%d); exiting",dev,unit);
	415	exit_handler(0);
	416	}
	417	/* Run config_cmd if specified before exiting. */
	418	void exit_handler(int ret)
	419	{
	420	/*
	421	* First close the slip line in case exit_cmd wants it (like to hang
	422	* up a modem or something).
	423	*/
	424	if (fd != -1)
	425	close(fd);
	426	/* invoke a shell for exit_cmd. */
	427	if (exit_cmd) {
	428	syslog(LOG_NOTICE,"exiting after running %s", exit_cmd);
	429	system(exit_cmd);
	430	}
	431	exit(ret);
	432	}
	433
	434	/* local variables: */
	435	/* c-indent-level: 8 */
	436	/* c-argdecl-indent: 0 */
	437	/* c-label-offset: -8 */
	438	/* c-continued-statement-offset: 8 */
	439	/* c-brace-offset: 0 */
	440	/* comment-column: 32 */
	441	/* end: */