378 lines
10 KiB
C
378 lines
10 KiB
C
/* $NetBSD: sliplogin.c,v 1.24 2013/10/19 17:16:38 christos Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 1990, 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. 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.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
#ifndef lint
|
|
__COPYRIGHT("@(#) Copyright (c) 1990, 1993\
|
|
The Regents of the University of California. All rights reserved.");
|
|
#endif /* not lint */
|
|
|
|
#ifndef lint
|
|
#if 0
|
|
static char sccsid[] = "@(#)sliplogin.c 8.2 (Berkeley) 2/1/94";
|
|
#else
|
|
__RCSID("$NetBSD: sliplogin.c,v 1.24 2013/10/19 17:16:38 christos Exp $");
|
|
#endif
|
|
#endif /* not lint */
|
|
|
|
/*
|
|
* sliplogin.c
|
|
* [MUST BE RUN SUID, SLOPEN DOES A SUSER()!]
|
|
*
|
|
* This program initializes its own tty port to be an async TCP/IP interface.
|
|
* It sets the line discipline to slip, invokes a shell script to initialize
|
|
* the network interface, then pauses forever waiting for hangup.
|
|
*
|
|
* It is a remote descendant of several similar programs with incestuous ties:
|
|
* - Kirk Smith's slipconf, modified by Richard Johnsson @ DEC WRL.
|
|
* - slattach, probably by Rick Adams but touched by countless hordes.
|
|
* - the original sliplogin for 4.2bsd, Doug Kingston the mover behind it.
|
|
*
|
|
* There are two forms of usage:
|
|
*
|
|
* "sliplogin"
|
|
* Invoked simply as "sliplogin", the program looks up the username
|
|
* in the file /etc/slip.hosts.
|
|
* If an entry is found, the line on fd0 is configured for SLIP operation
|
|
* as specified in the file.
|
|
*
|
|
* "sliplogin IPhostlogin </dev/ttyb"
|
|
* Invoked by root with a username, the name is looked up in the
|
|
* /etc/slip.hosts file and if found fd0 is configured as in case 1.
|
|
*/
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/file.h>
|
|
#include <sys/param.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/syslog.h>
|
|
|
|
#if BSD >= 199006
|
|
#define POSIX
|
|
#endif
|
|
#ifdef POSIX
|
|
#include <termios.h>
|
|
#include <sys/ioctl.h>
|
|
#include <ttyent.h>
|
|
#else
|
|
#include <sgtty.h>
|
|
#endif
|
|
#include <net/slip.h>
|
|
|
|
#include <ctype.h>
|
|
#include <err.h>
|
|
#include <errno.h>
|
|
#include <netdb.h>
|
|
#include <signal.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
#include "pathnames.h"
|
|
|
|
static int unit;
|
|
static int speed;
|
|
static int uid;
|
|
static char loginargs[BUFSIZ];
|
|
static char loginfile[MAXPATHLEN];
|
|
static char loginname[BUFSIZ];
|
|
|
|
static void findid(const char *);
|
|
__dead static void hup_handler(int);
|
|
static const char *sigstr(int);
|
|
|
|
static void
|
|
findid(const char *name)
|
|
{
|
|
FILE *fp;
|
|
static char slopt[5][16];
|
|
static char laddr[16];
|
|
static char raddr[16];
|
|
static char mask[16];
|
|
char user[16];
|
|
|
|
(void)strlcpy(loginname, name, sizeof(loginname));
|
|
if ((fp = fopen(_PATH_ACCESS, "r")) == NULL) {
|
|
syslog(LOG_ERR, "%s: %m\n", _PATH_ACCESS);
|
|
err(1, "%s", _PATH_ACCESS);
|
|
}
|
|
while (fgets(loginargs, sizeof(loginargs) - 1, fp)) {
|
|
if (ferror(fp))
|
|
break;
|
|
(void)sscanf(loginargs, "%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]"
|
|
"%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s%*[ \t]%15s"
|
|
"%*[ \t]%15s\n",
|
|
user, laddr, raddr, mask, slopt[0], slopt[1],
|
|
slopt[2], slopt[3], slopt[4]);
|
|
if (user[0] == '#' || isspace((unsigned char)user[0]))
|
|
continue;
|
|
if (strcmp(user, name) != 0)
|
|
continue;
|
|
|
|
/*
|
|
* we've found the guy we're looking for -- see if
|
|
* there's a login file we can use. First check for
|
|
* one specific to this host. If none found, try for
|
|
* a generic one.
|
|
*/
|
|
(void)snprintf(loginfile, sizeof loginfile, "%s.%s",
|
|
_PATH_LOGIN, name);
|
|
if (access(loginfile, R_OK|X_OK) != 0) {
|
|
(void)strlcpy(loginfile, _PATH_LOGIN, sizeof(loginfile));
|
|
if (access(loginfile, R_OK|X_OK)) {
|
|
fputs("access denied - no login file\n",
|
|
stderr);
|
|
syslog(LOG_ERR,
|
|
"access denied for %s - no %s\n",
|
|
name, _PATH_LOGIN);
|
|
exit(5);
|
|
}
|
|
}
|
|
|
|
(void)fclose(fp);
|
|
return;
|
|
}
|
|
syslog(LOG_ERR, "SLIP access denied for %s\n", name);
|
|
errx(1, "SLIP access denied for %s", name);
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
static const char *
|
|
sigstr(int s)
|
|
{
|
|
|
|
if (s > 0 && s < NSIG)
|
|
return (sys_signame[s]);
|
|
else {
|
|
static char buf[32];
|
|
|
|
(void)snprintf(buf, sizeof buf, "sig %d", s);
|
|
return (buf);
|
|
}
|
|
}
|
|
|
|
static void
|
|
hup_handler(int s)
|
|
{
|
|
char logoutfile[MAXPATHLEN];
|
|
|
|
(void)snprintf(logoutfile, sizeof logoutfile, "%s.%s", _PATH_LOGOUT,
|
|
loginname);
|
|
if (access(logoutfile, R_OK|X_OK) != 0)
|
|
(void)strlcpy(logoutfile, _PATH_LOGOUT, sizeof(logoutfile));
|
|
if (access(logoutfile, R_OK|X_OK) == 0) {
|
|
char logincmd[2*MAXPATHLEN+32];
|
|
|
|
(void)snprintf(logincmd, sizeof logincmd, "%s %d %d %s",
|
|
logoutfile, unit, speed, loginargs);
|
|
(void)system(logincmd);
|
|
}
|
|
(void)close(0);
|
|
syslog(LOG_INFO, "closed %s slip unit %d (%s)\n", loginname, unit,
|
|
sigstr(s));
|
|
exit(1);
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
int
|
|
main(int argc, char *argv[])
|
|
{
|
|
int fd, s, ldisc, odisc;
|
|
char *name;
|
|
#ifdef POSIX
|
|
struct termios tios, otios;
|
|
#else
|
|
struct sgttyb tty, otty;
|
|
#endif
|
|
char logincmd[2*BUFSIZ+32];
|
|
|
|
if (strlen(argv[0]) > MAXLOGNAME)
|
|
errx(1, "login %s too long", argv[0]);
|
|
if ((name = strrchr(argv[0], '/')) == NULL)
|
|
name = argv[0];
|
|
else
|
|
name++;
|
|
s = getdtablesize();
|
|
for (fd = 3 ; fd < s ; fd++)
|
|
(void)close(fd);
|
|
openlog(name, LOG_PID, LOG_DAEMON);
|
|
uid = getuid();
|
|
if (argc > 1) {
|
|
findid(argv[1]);
|
|
|
|
/*
|
|
* Disassociate from current controlling terminal, if any,
|
|
* and ensure that the slip line is our controlling terminal.
|
|
*/
|
|
#ifdef POSIX
|
|
switch (fork()) {
|
|
case -1:
|
|
perror("fork");
|
|
syslog(LOG_ERR, "could not fork: %m");
|
|
exit(1);
|
|
case 0:
|
|
break;
|
|
default:
|
|
exit(0);
|
|
}
|
|
if (setsid() < 0)
|
|
perror("setsid");
|
|
#else
|
|
if ((fd = open("/dev/tty", O_RDONLY, 0)) >= 0) {
|
|
extern char *ttyname();
|
|
|
|
(void)ioctl(fd, TIOCNOTTY, (caddr_t)0);
|
|
(void)close(fd);
|
|
/* open slip tty again to acquire as controlling tty? */
|
|
fd = open(ttyname(0), O_RDWR, 0);
|
|
if (fd >= 0)
|
|
(void)close(fd);
|
|
}
|
|
(void)setpgrp(0, getpid());
|
|
#endif
|
|
if (argc > 2) {
|
|
if ((fd = open(argv[2], O_RDWR)) == -1) {
|
|
perror(argv[2]);
|
|
exit(2);
|
|
}
|
|
(void)dup2(fd, 0);
|
|
if (fd > 2)
|
|
close(fd);
|
|
}
|
|
#ifdef TIOCSCTTY
|
|
if (ioctl(STDIN_FILENO, TIOCSCTTY, (caddr_t)0) != 0)
|
|
perror("ioctl (TIOCSCTTY)");
|
|
#endif
|
|
} else {
|
|
if ((name = getlogin()) == NULL) {
|
|
syslog(LOG_ERR,
|
|
"access denied - getlogin returned 0\n");
|
|
errx(1, "access denied - no username");
|
|
}
|
|
findid(name);
|
|
}
|
|
if (!isatty(STDIN_FILENO)) {
|
|
syslog(LOG_ERR, "stdin not a tty");
|
|
errx(1, "stdin not a tty");
|
|
}
|
|
(void)fchmod(STDIN_FILENO, 0600);
|
|
warnx("starting slip login for %s", loginname);
|
|
#ifdef POSIX
|
|
/* set up the line parameters */
|
|
if (tcgetattr(STDIN_FILENO, &tios) < 0) {
|
|
syslog(LOG_ERR, "tcgetattr: %m");
|
|
exit(1);
|
|
}
|
|
otios = tios;
|
|
cfmakeraw(&tios);
|
|
tios.c_iflag &= ~IMAXBEL;
|
|
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &tios) < 0) {
|
|
syslog(LOG_ERR, "tcsetattr: %m");
|
|
exit(1);
|
|
}
|
|
speed = cfgetispeed(&tios);
|
|
#else
|
|
/* set up the line parameters */
|
|
if (ioctl(STDIN_FILENO, TIOCGETP, (caddr_t)&tty) < 0) {
|
|
syslog(LOG_ERR, "ioctl (TIOCGETP): %m");
|
|
exit(1);
|
|
}
|
|
otty = tty;
|
|
speed = tty.sg_ispeed;
|
|
tty.sg_flags = RAW | ANYP;
|
|
if (ioctl(STDIN_FILENO, TIOCSETP, (caddr_t)&tty) < 0) {
|
|
syslog(LOG_ERR, "ioctl (TIOCSETP): %m");
|
|
exit(1);
|
|
}
|
|
#endif
|
|
/* find out what ldisc we started with */
|
|
if (ioctl(STDIN_FILENO, TIOCGETD, (caddr_t)&odisc) < 0) {
|
|
syslog(LOG_ERR, "ioctl(TIOCGETD) (1): %m");
|
|
exit(1);
|
|
}
|
|
ldisc = SLIPDISC;
|
|
if (ioctl(STDIN_FILENO, TIOCSETD, (caddr_t)&ldisc) < 0) {
|
|
syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
|
|
exit(1);
|
|
}
|
|
/* find out what unit number we were assigned */
|
|
if (ioctl(STDIN_FILENO, SLIOCGUNIT, (caddr_t)&unit) < 0) {
|
|
syslog(LOG_ERR, "ioctl (SLIOCGUNIT): %m");
|
|
exit(1);
|
|
}
|
|
(void)signal(SIGHUP, hup_handler);
|
|
(void)signal(SIGTERM, hup_handler);
|
|
|
|
syslog(LOG_INFO, "attaching slip unit %d for %s\n", unit, loginname);
|
|
(void)snprintf(logincmd, sizeof logincmd, "%s %d %d %s", loginfile,
|
|
unit, speed, loginargs);
|
|
/*
|
|
* aim stdout and errout at /dev/null so logincmd output won't
|
|
* babble into the slip tty line.
|
|
*/
|
|
(void)close(1);
|
|
if ((fd = open(_PATH_DEVNULL, O_WRONLY)) != 1) {
|
|
if (fd < 0) {
|
|
syslog(LOG_ERR, "open /dev/null: %m");
|
|
exit(1);
|
|
}
|
|
(void)dup2(fd, 1);
|
|
(void)close(fd);
|
|
}
|
|
(void)dup2(1, 2);
|
|
|
|
/*
|
|
* Run login and logout scripts as root (real and effective);
|
|
* current route(8) is setuid root, and checks the real uid
|
|
* to see whether changes are allowed (or just "route get").
|
|
*/
|
|
(void)setuid(0);
|
|
if ((s = system(logincmd)) != 0) {
|
|
syslog(LOG_ERR, "%s login failed: exit status %d from %s",
|
|
loginname, s, loginfile);
|
|
(void)ioctl(STDIN_FILENO, TIOCSETD, (caddr_t)&odisc);
|
|
#ifdef POSIX
|
|
(void)tcsetattr(STDIN_FILENO, TCSAFLUSH, &otios);
|
|
#else
|
|
(void)ioctl(STDIN_FILENO, TIOCSETP, (caddr_t)&otty);
|
|
#endif
|
|
exit(6);
|
|
}
|
|
|
|
/* twiddle thumbs until we get a signal */
|
|
while (1)
|
|
sigpause(0);
|
|
|
|
/* NOTREACHED */
|
|
}
|