FreeBSD-5.3/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.
* 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.
*/
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1988 Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "from: @(#)slattach.c 4.6 (Berkeley) 6/1/90";
#endif
static const char rcsid[] =
"$FreeBSD: src/sbin/slattach/slattach.c,v 1.40 2004/04/09 19:58:39 markm Exp $";
#endif /* not lint */
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <err.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/if.h>
#include <net/slip.h>
#define DEFAULT_BAUD 9600
void sighup_handler(); /* SIGHUP handler */
void sigint_handler(); /* SIGINT handler */
void sigterm_handler(); /* SIGTERM handler */
void sigurg_handler(); /* SIGURG handler */
void exit_handler(int ret); /* run exit_cmd iff specified upon exit. */
void setup_line(int cflag); /* configure terminal settings */
void slip_discipline(); /* switch to slip line discipline */
void configure_network(); /* configure slip interface */
void acquire_line(); /* get tty device as controlling terminal */
static void usage(void);
int fd = -1;
char *dev = (char *)0; /* path name of the tty (e.g. /dev/tty01) */
char *dvname; /* basename of dev */
int locked = 0; /* uucp lock active */
int flow_control = 0; /* non-zero to enable hardware flow control. */
int modem_control = HUPCL; /* !CLOCAL+HUPCL 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 */
speed_t speed = DEFAULT_BAUD; /* baud rate of tty */
int slflags = 0; /* compression flags */
int unit = -1; /* slip device unit number */
int foreground = 0; /* act as daemon if zero, else don't fork. */
int keepal = 0; /* keepalive timeout */
int outfill = 0; /* outfill timeout */
int sl_unit = -1; /* unit number */
int uucp_lock = 0; /* do uucp locking */
int exiting = 0; /* already running exit_handler */
struct termios tty; /* tty configuration/state */
char tty_path[32]; /* path name of the tty (e.g. /dev/tty01) */
char pidfilename[40]; /* e.g. /var/run/slattach.tty01.pid */
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. */
static void
usage()
{
fprintf(stderr, "%s\n%s\n",
"usage: slattach [-acfhlnz] [-e command] [-r command] [-s speed] [-u command]",
" [-L] [-K timeout] [-O timeout] [-S unit] device");
/* do not exit here */
}
int
main(int argc, char **argv)
{
int option;
while ((option = getopt(argc, argv, "ace:fhlnr:s:u:zLK:O:S:")) != -1) {
switch (option) {
case 'a':
slflags |= IFF_LINK2;
slflags &= ~IFF_LINK0;
break;
case 'c':
slflags |= IFF_LINK0;
slflags &= ~IFF_LINK2;
break;
case 'e':
exit_cmd = strdup (optarg);
break;
case 'f':
foreground = 1;
break;
case 'h':
flow_control |= CRTSCTS;
break;
case 'l':
modem_control = CLOCAL; /* clear HUPCL too */
break;
case 'n':
slflags |= IFF_LINK1;
break;
case 'r':
redial_cmd = strdup (optarg);
break;
case 's':
speed = atoi(optarg);
break;
case 'u':
config_cmd = strdup (optarg);
break;
case 'z':
redial_on_startup = 1;
break;
case 'L':
uucp_lock = 1;
break;
case 'K':
keepal = atoi(optarg);
break;
case 'O':
outfill = atoi(optarg);
break;
case 'S':
sl_unit = atoi(optarg);
break;
case '?':
default:
usage();
exit_handler(1);
}
}
if (optind == argc - 1)
dev = argv[optind];
if (optind < (argc - 1))
warnx("too many args, first='%s'", argv[optind]);
if (optind > (argc - 1))
warnx("not enough args");
if (dev == (char *)0) {
usage();
exit_handler(2);
}
if (strncmp(_PATH_DEV, dev, sizeof(_PATH_DEV) - 1)) {
strcpy(tty_path, _PATH_DEV);
strcat(tty_path, "/");
strncat(tty_path, dev, 10);
dev = tty_path;
}
dvname = strrchr(dev, '/'); /* always succeeds */
dvname++; /* trailing tty pathname component */
snprintf(pidfilename, sizeof(pidfilename),
"%sslattach.%s.pid", _PATH_VARRUN, dvname);
printf("%s\n",pidfilename);
if (!foreground)
daemon(0,0); /* fork, setsid, chdir /, and close std*. */
/* daemon() closed stderr, so log errors from here on. */
openlog("slattach",LOG_CONS|LOG_PID,LOG_DAEMON);
acquire_line(); /* get tty device as controlling terminal */
setup_line(0); /* configure for slip line discipline */
slip_discipline(); /* switch to slip line discipline */
/* upon INT log a timestamp and exit. */
if (signal(SIGINT,sigint_handler) == SIG_ERR)
syslog(LOG_NOTICE,"cannot install SIGINT handler: %m");
/* upon TERM log a timestamp and exit. */
if (signal(SIGTERM,sigterm_handler) == SIG_ERR)
syslog(LOG_NOTICE,"cannot install SIGTERM handler: %m");
/* upon HUP redial and reconnect. */
if (signal(SIGHUP,sighup_handler) == SIG_ERR)
syslog(LOG_NOTICE,"cannot install SIGHUP handler: %m");
if (redial_on_startup)
sighup_handler();
else if (!(modem_control & CLOCAL)) {
if (ioctl(fd, TIOCMGET, &comstate) < 0)
syslog(LOG_NOTICE,"cannot get carrier state: %m");
if (!(comstate & TIOCM_CD)) { /* check for carrier */
/* force a redial if no carrier */
kill (getpid(), SIGHUP);
} else
configure_network();
} else
configure_network(); /* configure the network if needed. */
for (;;) {
sigset_t mask;
sigemptyset(&mask);
sigsuspend(&mask);
}
}
/* Close all FDs, fork, reopen tty port as 0-2, and make it the
controlling terminal for our process group. */
void acquire_line()
{
int ttydisc = TTYDISC;
int oflags;
FILE *pidfile;
/* reset to tty discipline */
if (fd >= 0 && ioctl(fd, TIOCSETD, &ttydisc) < 0) {
syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
exit_handler(1);
}
(void)close(STDIN_FILENO); /* close FDs before forking. */
(void)close(STDOUT_FILENO);
(void)close(STDERR_FILENO);
if (fd > 2)
(void)close(fd);
signal(SIGHUP, SIG_IGN); /* ignore HUP signal when parent dies. */
if (daemon(0,0)) { /* fork, setsid, chdir /, and close std*. */
syslog(LOG_ERR, "daemon(0,0): %m");
exit_handler(1);
}
while (getppid () != 1)
sleep (1); /* Wait for parent to die. */
/* create PID file */
if((pidfile = fopen(pidfilename, "w"))) {
fprintf(pidfile, "%ld\n", (long)getpid());
fclose(pidfile);
}
if (signal(SIGHUP,sighup_handler) == SIG_ERR) /* Re-enable HUP signal */
syslog(LOG_NOTICE,"cannot install SIGHUP handler: %m");
if (uucp_lock) {
/* unlock not needed here, always re-lock with new pid */
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, "can't lock %s", dev);
exit_handler(1);
}
locked = 1;
}
if ((fd = open(dev, O_RDWR | O_NONBLOCK, 0)) < 0) {
syslog(LOG_ERR, "open(%s) %m", dev);
exit_handler(1);
}
/* Turn off O_NONBLOCK for dumb redialers, if any. */
if ((oflags = fcntl(fd, F_GETFL)) == -1) {
syslog(LOG_ERR, "fcntl(F_GETFL) failed: %m");
exit_handler(1);
}
if (fcntl(fd, F_SETFL, oflags & ~O_NONBLOCK) == -1) {
syslog(LOG_ERR, "fcntl(F_SETFL) failed: %m");
exit_handler(1);
}
(void)dup2(fd, STDIN_FILENO);
(void)dup2(fd, STDOUT_FILENO);
(void)dup2(fd, STDERR_FILENO);
if (fd > 2)
(void)close (fd);
fd = STDIN_FILENO;
/* acquire the serial line as a controlling terminal. */
if (ioctl(fd, TIOCSCTTY, 0) < 0) {
syslog(LOG_ERR,"ioctl(TIOCSCTTY): %m");
exit_handler(1);
}
/* 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: %m");
}
/* Set the tty flags and set DTR. */
/* Call as setup_line(CLOCAL) to force clocal assertion. */
void setup_line(int cflag)
{
tty.c_lflag = tty.c_iflag = tty.c_oflag = 0;
tty.c_cflag = CREAD | CS8 | flow_control | modem_control | cflag;
cfsetispeed(&tty, speed);
cfsetospeed(&tty, 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);
}
}
/* Put the line in slip discipline. */
void slip_discipline()
{
struct ifreq ifr;
int slipdisc = SLIPDISC;
int s, tmp_unit = -1;
/* Switch to slip line discipline. */
if (ioctl(fd, TIOCSETD, &slipdisc) < 0) {
syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
exit_handler(1);
}
if (sl_unit >= 0 && ioctl(fd, SLIOCSUNIT, &sl_unit) < 0) {
syslog(LOG_ERR, "ioctl(SLIOCSUNIT): %m");
exit_handler(1);
}
/* find out what unit number we were assigned */
if (ioctl(fd, SLIOCGUNIT, (caddr_t)&tmp_unit) < 0) {
syslog(LOG_ERR, "ioctl(SLIOCGUNIT): %m");
exit_handler(1);
}
if (tmp_unit < 0) {
syslog(LOG_ERR, "bad unit (%d) from ioctl(SLIOCGUNIT)",tmp_unit);
exit_handler(1);
}
if (keepal > 0) {
signal(SIGURG, sigurg_handler);
if (ioctl(fd, SLIOCSKEEPAL, &keepal) < 0) {
syslog(LOG_ERR, "ioctl(SLIOCSKEEPAL): %m");
exit_handler(1);
}
}
if (outfill > 0 && ioctl(fd, SLIOCSOUTFILL, &outfill) < 0) {
syslog(LOG_ERR, "ioctl(SLIOCSOUTFILL): %m");
exit_handler(1);
}
/* open a socket as the handle to the interface */
s = socket(AF_INET, SOCK_DGRAM, 0);
if (s < 0) {
syslog(LOG_ERR, "socket: %m");
exit_handler(1);
}
sprintf(ifr.ifr_name, "sl%d", tmp_unit);
/* get the flags for the interface */
if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) {
syslog(LOG_ERR, "ioctl (SIOCGIFFLAGS): %m");
exit_handler(1);
}
/* Assert any compression or no-icmp flags. */
#define SLMASK (~(IFF_LINK0 | IFF_LINK1 | IFF_LINK2))
ifr.ifr_flags &= SLMASK;
ifr.ifr_flags |= slflags;
if (ioctl(s, SIOCSIFFLAGS, (caddr_t)&ifr) < 0) {
syslog(LOG_ERR, "ioctl (SIOCSIFFLAGS): %m");
exit_handler(1);
}
close(s);
}
/* configure the interface, e.g. by passing the unit number to a script. */
void configure_network()
{
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);
}
/* iff the unit number changes either invoke config_cmd or punt. */
if (config_cmd) {
char *s;
s = (char*) malloc(strlen(config_cmd) + 32);
if (s == NULL) {
syslog(LOG_ERR, "malloc failed");
exit(1);
}
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 {
/* don't compare unit numbers if this is the first time to attach. */
if (unit < 0)
unit = new_unit;
if (new_unit != unit) {
syslog(LOG_ERR,
"slip unit changed from sl%d to sl%d, but no -u CMD was specified!",
unit, new_unit);
exit_handler(1);
}
syslog(LOG_NOTICE,"sl%d connected to %s at %d baud",unit,dev,speed);
}
}
/* sighup_handler() is invoked when carrier drops, eg. before redial. */
void sighup_handler()
{
if(exiting) return;
if (redial_cmd == NULL) {
syslog(LOG_NOTICE,"SIGHUP on %s (sl%d); exiting", dev, unit);
exit_handler(1);
}
again:
/* invoke a shell for redial_cmd or punt. */
if (*redial_cmd) { /* Non-empty redial command */
syslog(LOG_NOTICE,"SIGHUP on %s (sl%d); running '%s'",
dev, unit, redial_cmd);
acquire_line(); /* reopen dead line */
setup_line(CLOCAL);
if (locked) {
if (uucp_lock)
uu_unlock(dvname); /* for redial */
locked = 0;
}
if (system(redial_cmd))
goto again;
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, "can't relock %s after %s, aborting",
dev, redial_cmd);
exit_handler(1);
}
locked = 1;
}
/* Now check again for carrier (dial command is done): */
if (!(modem_control & CLOCAL)) {
tty.c_cflag &= ~CLOCAL;
if (tcsetattr(fd, TCSAFLUSH, &tty) < 0) {
syslog(LOG_ERR, "tcsetattr(TCSAFLUSH): %m");
exit_handler(1);
}
ioctl(fd, TIOCMGET, &comstate);
if (!(comstate & TIOCM_CD)) { /* check for carrier */
/* force a redial if no carrier */
goto again;
}
} else
setup_line(0);
} else { /* Empty redial command */
syslog(LOG_NOTICE,"SIGHUP on %s (sl%d); reestablish connection",
dev, unit);
acquire_line(); /* reopen dead line */
setup_line(0); /* restore ospeed from hangup (B0) */
/* If modem control, just wait for carrier before attaching.
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. */
/* We must poll since CLOCAL prevents signal. */
while (! carrier) {
sleep(2);
ioctl(fd, TIOCMGET, &comstate);
if (comstate & TIOCM_CD)
carrier = 1;
}
syslog(LOG_NOTICE, "carrier now present on %s (sl%d)",
dev, unit);
}
}
slip_discipline();
configure_network();
}
/* Signal handler for SIGINT. We just log and exit. */
void sigint_handler()
{
if(exiting) return;
syslog(LOG_NOTICE,"SIGINT on %s (sl%d); exiting",dev,unit);
exit_handler(0);
}
/* Signal handler for SIGURG. */
void sigurg_handler()
{
int ttydisc = TTYDISC;
signal(SIGURG, SIG_IGN);
if(exiting) return;
syslog(LOG_NOTICE,"SIGURG on %s (sl%d); hangup",dev,unit);
if (ioctl(fd, TIOCSETD, &ttydisc) < 0) {
syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
exit_handler(1);
}
cfsetospeed(&tty, B0);
if (tcsetattr(fd, TCSANOW, &tty) < 0) {
syslog(LOG_ERR, "tcsetattr(TCSANOW): %m");
exit_handler(1);
}
/* Need to go to sighup handler in any case */
if (modem_control & CLOCAL)
kill (getpid(), SIGHUP);
}
/* Signal handler for SIGTERM. We just log and exit. */
void sigterm_handler()
{
if(exiting) return;
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)
{
if(exiting) return;
exiting = 1;
/*
* First close the slip line in case exit_cmd wants it (like to hang
* up a modem or something).
*/
if (fd != -1)
close(fd);
if (uucp_lock && locked)
uu_unlock(dvname);
/* Remove the PID file */
(void)unlink(pidfilename);
if (config_cmd) {
char *s;
s = (char*) malloc(strlen(config_cmd) + 32);
if (s == NULL) {
syslog(LOG_ERR, "malloc failed");
exit(1);
}
sprintf (s, "%s %d -1", config_cmd, unit);
syslog(LOG_NOTICE, "deconfiguring %s (sl%d):", dev, unit);
syslog(LOG_NOTICE, " '%s'", s);
system(s);
free (s);
}
/* 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: */