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/*
* gdmopen.c by the Queen of England, based upon original open.
* Simplified for the purposes of gdm. All useless (to me)
* functionality stripped. Also returns what the command returns.
* Return of 66 means error with open.
*
* Original header:
*
* open.c open a vt to run a new command (or shell).
*
* Copyright (c) 1994 by Jon Tombs <jon@gtex02.us.es>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include "config.h"
#include <stdio.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <dirent.h>
#include <pwd.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/vt.h>
#include <sys/types.h>
#include <sys/wait.h>
#ifndef FALSE
#define FALSE 0
#define TRUE !FALSE
#endif
/*
* Where your VTs are hidden
*/
#ifdef __linux__
#define VTNAME "/dev/tty%d"
#endif
#ifdef ESIX_5_3_2_D
#define VTBASE "/dev/vt%02d"
#endif
const char *GDMOPENversion = "gdmopen " VERSION " simplified (was: open: 1.4 (c) Jon Tombs 1994)";
#ifndef VTNAME
#error vt device name must be defined in open.c
#endif
static pid_t child_pid = -1;
struct vt_stat vt;
static int vtno;
static int fd = 0;
static int do_switchback = FALSE;
static void
sighandler (int sig)
{
if (child_pid > 1) {
if (kill (child_pid, sig) == 0)
waitpid (child_pid, NULL, 0);
}
if (do_switchback) {
/* Switch back... */
(void) ioctl(fd, VT_ACTIVATE, vt.v_active);
/* wait to be really sure we have switched */
(void) ioctl(fd, VT_WAITACTIVE, vt.v_active);
}
/* Kill myself with this signal */
signal (sig, SIG_DFL);
kill (getpid (), sig);
}
int
main (int argc, char *argv[])
{
char vtname[256];
int status;
int cmd_start = 1;
char *command = NULL;
if (getuid () != geteuid () ||
getuid () != 0) {
fprintf (stderr, "gdmopen: Only root wants to run me\n");
return 66;
}
signal (SIGTERM, sighandler);
signal (SIGINT, sighandler);
signal (SIGHUP, sighandler);
if (argc <= 1) {
fprintf (stderr, "gdmopen: must supply a command!\n");
return 66;
}
command = argv[1];
if (strcmp (argv[1], "-l") == 0) {
char *p;
if (argc <= 2) {
fprintf (stderr, "gdmopen: must supply a command!\n");
return 66;
}
/* prepend '-' and start the command at
* argument 2 */
cmd_start = 2;
command = argv[2];
argv[2] = malloc (strlen (command) + 2);
p = strrchr (command, '/');
if (p != NULL) {
/* make it "-basename" */
strcpy (argv[2]+1, p+1);
} else {
strcpy (argv[2]+1, command);
}
*(argv[2]) = '-';
}
fd = open ("/dev/console", O_WRONLY, 0);
if (fd < 0) {
perror ("gdmopen: Failed to open /dev/console");
return 66;
}
errno = 0;
if ((ioctl(fd, VT_OPENQRY, &vtno) < 0) || (vtno == -1)) {
perror ("gdmopen: Cannot find a free VT");
close (fd);
return 66;
}
if (ioctl(fd, VT_GETSTATE, &vt) < 0) {
perror ("gdmopen: can't get VTstate");
close(fd);
return 66;
}
snprintf (vtname, sizeof (vtname), VTNAME, vtno);
chown (vtname, 0, -1);
child_pid = fork();
if (child_pid == 0) {
char VT_NUMBER[256];
snprintf (VT_NUMBER, sizeof (VT_NUMBER), "VT_NUMBER=%d", vtno);
putenv (VT_NUMBER);
signal (SIGTERM, SIG_DFL);
signal (SIGINT, SIG_DFL);
signal (SIGHUP, SIG_DFL);
/* leave current vt */
if (
#ifdef ESIX_5_3_2_D
setpgrp() < 0
#else
setsid() < 0
#endif
) {
fprintf(stderr, "open: Unable to set new session (%s)\n",
strerror(errno));
}
close(0);
close(1);
close(2);
close(fd);
/* and grab new one */
fd = open (vtname, O_RDWR);
if (fd < 0) { /* Shouldn't happen */
_exit (66); /* silently die */
}
dup(fd);
dup(fd);
/*
* Can't tell anyone if any of these fail, so throw away
* the return values
*/
(void) ioctl(fd, VT_ACTIVATE, vtno);
/* wait to be really sure we have switched */
(void) ioctl(fd, VT_WAITACTIVE, vtno);
#ifdef __linux__
/* Turn on fonts */
write (0, "\033(K", 3);
#endif /* __linux__ */
execvp (command, &argv[cmd_start]);
_exit (66); /* failed */
}
if (child_pid < 0) {
perror ("gdmopen: fork() error");
return 66;
}
do_switchback = TRUE;
waitpid (child_pid, &status, 0);
child_pid = -1;
do_switchback = FALSE;
/* Switch back... */
(void) ioctl(fd, VT_ACTIVATE, vt.v_active);
/* wait to be really sure we have switched */
(void) ioctl(fd, VT_WAITACTIVE, vt.v_active);
close (fd);
if (WIFEXITED (status))
return WEXITSTATUS (status);
else
return 66;
}
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