* 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.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
-/* getopt not needed */
+//usage:#define openvt_trivial_usage
+//usage: "[-c N] [-sw] [PROG ARGS]"
+//usage:#define openvt_full_usage "\n\n"
+//usage: "Start PROG on a new virtual terminal\n"
+//usage: "\n -c N Use specified VT"
+//usage: "\n -s Switch to the VT"
+/* //usage: "\n -l Run PROG as login shell (by prepending '-')" */
+//usage: "\n -w Wait for PROG to exit"
+//usage:
+//usage:#define openvt_example_usage
+//usage: "openvt 2 /bin/ash\n"
-#include "busybox.h"
+#include <linux/vt.h>
+#include "libbb.h"
-int openvt_main(int argc, char **argv);
-int openvt_main(int argc, char **argv)
+/* "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;
- char vtname[sizeof(VC_FORMAT) + 2];
- if (argc < 3) {
- bb_show_usage();
+ /* 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);
}
- /* check for illegal vt number: < 1 or > 63 */
- sprintf(vtname, VC_FORMAT, (int)xatou_range(argv[1], 1, 63));
-
-//FIXME NOMMU
- if (fork() == 0) {
- /* child */
- /* leave current vt (controlling tty) */
- setsid();
- /* and grab new one */
- fd = xopen(vtname, O_RDWR);
- /* Reassign stdin, stdout and sterr */
- dup2(fd, STDIN_FILENO);
- dup2(fd, STDOUT_FILENO);
- dup2(fd, STDERR_FILENO);
- while (fd > 2) close(fd--);
-
- BB_EXECVP(argv[2], &argv[2]);
- _exit(1);
+}
+
+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] = (char *) get_shell_name();
+ /*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;
}
projects / platform / upstream / busybox.git / blobdiff