busybox/console-tools/openvt.c
Pascal Bellard 21e8e8da64 libbb: introduce and use BB_EXECVP_or_die()
function                                             old     new   delta
BB_EXECVP_or_die                                       -      47     +47
time_main                                           1042    1043      +1
chrt_main                                            371     364      -7
ionice_main                                          292     282     -10
setsid_main                                           69      56     -13
nohup_main                                           236     223     -13
cttyhack_main                                        266     253     -13
chroot_main                                           94      81     -13
chpst_main                                           746     733     -13
timeout_main                                         297     279     -18
taskset_main                                         541     522     -19
vfork_child                                           67      45     -22
parse                                                975     953     -22
lpd_main                                             770     748     -22
launch_helper                                        192     170     -22
tcpudpsvd_main                                      1810    1782     -28
nice_main                                            190     156     -34
env_main                                             242     206     -36
run_command                                          221     174     -47
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/17 up/down: 48/-352)         Total: -304 bytes

Signed-off-by: Pascal Bellard <pascal.bellard@ads-lu.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-07-04 00:57:03 +02:00

179 lines
4.5 KiB
C

/* vi: set sw=4 ts=4: */
/*
* openvt.c - open a vt to run a command.
*
* busyboxed by Quy Tonthat <quy@signal3.com>
* hacked by Tito <farmatito@tiscali.it>
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include <linux/vt.h>
#include "libbb.h"
/* "Standard" openvt's man page (we do not support all of this):
openvt [-c NUM] [-fsulv] [--] [command [args]]
Find the first available VT, and run command on it. Stdio is directed
to that VT. If no command is specified then $SHELL is used.
-c NUM
Use the given VT number, not the first free one.
-f
Force opening a VT: don't try to check if VT is already in use.
-s
Switch to the new VT when starting the command.
The VT of the new command will be made the new current VT.
-u
Figure out the owner of the current VT, and run login as that user.
Suitable to be called by init. Shouldn't be used with -c or -l.
-l
Make the command a login shell: a "-" is prepended to the argv[0]
when command is executed.
-v
Verbose.
-w
Wait for command to complete. If -w and -s are used together,
switch back to the controlling terminal when the command completes.
bbox:
-u: not implemented
-f: always in effect
-l: not implemented, ignored
-v: ignored
-ws: does NOT switch back
*/
/* Helper: does this fd understand VT_xxx? */
static int not_vt_fd(int fd)
{
struct vt_stat vtstat;
return ioctl(fd, VT_GETSTATE, &vtstat); /* !0: error, it's not VT fd */
}
/* Helper: get a fd suitable for VT_xxx */
static int get_vt_fd(void)
{
int fd;
/* Do we, by chance, already have it? */
for (fd = 0; fd < 3; fd++)
if (!not_vt_fd(fd))
return fd;
fd = open(DEV_CONSOLE, O_RDONLY | O_NONBLOCK);
if (fd >= 0 && !not_vt_fd(fd))
return fd;
bb_error_msg_and_die("can't find open VT");
}
static int find_free_vtno(void)
{
int vtno;
int fd = get_vt_fd();
errno = 0;
/*xfunc_error_retval = 3; - do we need compat? */
if (ioctl(fd, VT_OPENQRY, &vtno) != 0 || vtno <= 0)
bb_perror_msg_and_die("can't find open VT");
// Not really needed, grep for DAEMON_ONLY_SANITIZE
// if (fd > 2)
// close(fd);
return vtno;
}
/* vfork scares gcc, it generates bigger code.
* Keep it away from main program.
* TODO: move to libbb; or adapt existing libbb's spawn().
*/
static NOINLINE void vfork_child(char **argv)
{
if (vfork() == 0) {
/* CHILD */
/* Try to make this VT our controlling tty */
setsid(); /* lose old ctty */
ioctl(STDIN_FILENO, TIOCSCTTY, 0 /* 0: don't forcibly steal */);
//bb_error_msg("our sid %d", getsid(0));
//bb_error_msg("our pgrp %d", getpgrp());
//bb_error_msg("VT's sid %d", tcgetsid(0));
//bb_error_msg("VT's pgrp %d", tcgetpgrp(0));
BB_EXECVP_or_die(argv);
}
}
int openvt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int openvt_main(int argc UNUSED_PARAM, char **argv)
{
char vtname[sizeof(VC_FORMAT) + sizeof(int)*3];
struct vt_stat vtstat;
char *str_c;
int vtno;
int flags;
enum {
OPT_c = (1 << 0),
OPT_w = (1 << 1),
OPT_s = (1 << 2),
OPT_l = (1 << 3),
OPT_f = (1 << 4),
OPT_v = (1 << 5),
};
/* "+" - stop on first non-option */
flags = getopt32(argv, "+c:wslfv", &str_c);
argv += optind;
if (flags & OPT_c) {
/* Check for illegal vt number: < 1 or > 63 */
vtno = xatou_range(str_c, 1, 63);
} else {
vtno = find_free_vtno();
}
/* Grab new VT */
sprintf(vtname, VC_FORMAT, vtno);
/* (Try to) clean up stray open fds above fd 2 */
bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS | DAEMON_ONLY_SANITIZE, NULL);
close(STDIN_FILENO);
/*setsid(); - BAD IDEA: after we exit, child is SIGHUPed... */
xopen(vtname, O_RDWR);
xioctl(STDIN_FILENO, VT_GETSTATE, &vtstat);
if (flags & OPT_s) {
console_make_active(STDIN_FILENO, vtno);
}
if (!argv[0]) {
argv--;
argv[0] = getenv("SHELL");
if (!argv[0])
argv[0] = (char *) DEFAULT_SHELL;
/*argv[1] = NULL; - already is */
}
xdup2(STDIN_FILENO, STDOUT_FILENO);
xdup2(STDIN_FILENO, STDERR_FILENO);
#ifdef BLOAT
{
/* Handle -l (login shell) option */
const char *prog = argv[0];
if (flags & OPT_l)
argv[0] = xasprintf("-%s", argv[0]);
}
#endif
vfork_child(argv);
if (flags & OPT_w) {
/* We have only one child, wait for it */
safe_waitpid(-1, NULL, 0); /* loops on EINTR */
if (flags & OPT_s) {
console_make_active(STDIN_FILENO, vtstat.v_active);
// Compat: even with -c N (try to) disallocate:
// # /usr/app/kbd-1.12/bin/openvt -f -c 9 -ws sleep 5
// openvt: could not deallocate console 9
xioctl(STDIN_FILENO, VT_DISALLOCATE, (void*)(ptrdiff_t)vtno);
}
}
return EXIT_SUCCESS;
}