diff options
Diffstat (limited to 'utils/gdmopen.c')
| -rw-r--r-- | utils/gdmopen.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/utils/gdmopen.c b/utils/gdmopen.c new file mode 100644 index 00000000..d5c8574d --- /dev/null +++ b/utils/gdmopen.c @@ -0,0 +1,201 @@ +/* + * 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_dealloc = FALSE; + +static void +sighandler (int sig) +{ + if (child_pid > 1) { + if (kill (child_pid, sig) == 0) + waitpid (child_pid, NULL, 0); + } + + if (do_dealloc) { + /* 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); + + /* Now deallocate our new one */ + (void) ioctl(fd, VT_DISALLOCATE, vtno); + } + + /* Kill myself with this signal */ + signal (sig, SIG_DFL); + kill (getpid (), sig); +} + +int +main (int argc, char *argv[]) +{ + char vtname[256]; + int status; + + 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; + } + + 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) { + + 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); + + execvp (argv[1], &argv[1]); + + _exit (66); /* failed */ + } + + if (child_pid < 0) { + perror ("gdmopen: fork() error"); + return 66; + } + + do_dealloc = TRUE; + + waitpid (child_pid, &status, 0); + child_pid = -1; + + do_dealloc = 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); + + /* Now deallocate our new one */ + (void) ioctl(fd, VT_DISALLOCATE, vtno); + + close (fd); + + if (WIFEXITED (status)) + return WEXITSTATUS (status); + else + return 66; +} |