freebsd-nq/sbin/startslip/startslip.c
Josef Karthauser dee921f457 Fixes a potential buffer overflow with the pid filename.
Submitted by:	Mike Heffner <spock@techfour.net>
Submitted on:	audit@freebsd.org
2000-04-30 21:04:36 +00:00

602 lines
14 KiB
C

/*-
* 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. 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.
*/
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1990, 1991, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)startslip.c 8.1 (Berkeley) 6/5/93";
#endif
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#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 B9600
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 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
int carrier __P((void));
void down __P((int));
int getline __P((char *, int, int, time_t));
static void usage __P((void));
int
main(argc, argv)
int argc;
char **argv;
{
char *cp, **ap;
int ch, disc;
void sighup(), sigterm(), sigurg();
FILE *wfd = NULL;
char *dialerstring = 0, 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;
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++;
if (snprintf(pidfile, sizeof(pidfile), PIDFILE, _PATH_VARRUN, dvname) >= sizeof(pidfile))
usage();
if ((pfd = fopen(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);
(void) 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(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 (getline(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);
(void) 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 */
}
void
sighup()
{
printd("hup\n");
if (hup == 0 && logged_in)
syslog(LOG_INFO, "%s: got hangup signal", username);
hup = 1;
}
void
sigurg()
{
printd("urg\n");
if (hup == 0 && logged_in)
syslog(LOG_INFO, "%s: got dead line signal", username);
hup = 1;
}
void
sigterm()
{
printd("terminate\n");
if (terminate == 0 && logged_in)
syslog(LOG_INFO, "%s: got terminate signal", username);
terminate = 1;
}
int
getline(buf, size, fd, fintimeout)
char *buf;
int size, fd;
time_t fintimeout;
{
register 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(fd + 1, &readfds, NULL, NULL, &tv)) < 0) {
if (errno != EINTR)
syslog(LOG_ERR, "%s: getline: select: %m", username);
} else {
if (! ret) {
tout:
printd("getline: timed out\n");
return (0);
}
if ((ret = read(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: getline: 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);
}
int
carrier()
{
int comstate;
if (ioctl(fd, TIOCMGET, &comstate) < 0) {
syslog(LOG_ERR, "%s: ioctl (%s, TIOCMGET): %m",
username, devicename);
down(2);
}
return !!(comstate & TIOCM_CD);
}
void
down(code)
{
if (fd > -1)
close(fd);
if (pfd)
unlink(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);
}