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authorGravatar Denis Vlasenko <vda.linux@googlemail.com>2008-03-27 16:26:35 +0000
committerGravatar Denis Vlasenko <vda.linux@googlemail.com>2008-03-27 16:26:35 +0000
commit95891fc016c9911406cb826540873f0894bcbe8b (patch)
tree6bd21013d32cd589946742000c021ad95de61634 /console-tools/openvt.c
parent72b3442aeb948a9f27822d8888df765393b9ecd4 (diff)
downloadbusybox-95891fc016c9911406cb826540873f0894bcbe8b.tar.gz
busybox-95891fc016c9911406cb826540873f0894bcbe8b.tar.bz2
openvt: fix gross mismatch between us and "standard" openvt.
standard one even has different syntax! std: "openvt -c 12", we: "openvt 12" std: "openvt top", we: complain that "top" is not a number. openvt: implement -c -w -s (-l -f -v are also accepted but ingnored) openvt_main 188 343 +155 vfork_child - 67 +67 not_vt_fd - 23 +23 packed_usage 23932 23952 +20 ------------------------------------------------------------------------------ (add/remove: 2/0 grow/shrink: 2/0 up/down: 265/0) Total: 265 bytes text data bss dec hex filename 801344 641 7380 809365 c5995 busybox_old 801617 641 7380 809638 c5aa6 busybox_unstripped
Diffstat (limited to 'console-tools/openvt.c')
-rw-r--r--console-tools/openvt.c161
1 files changed, 148 insertions, 13 deletions
diff --git a/console-tools/openvt.c b/console-tools/openvt.c
index 39b985995..6f2aa19c4 100644
--- a/console-tools/openvt.c
+++ b/console-tools/openvt.c
@@ -8,29 +8,164 @@
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
-/* getopt not needed */
-
+#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;
+ /* _only_ O_NONBLOCK: ask for neither read not write perms */
+ fd = open(DEV_CONSOLE, 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(0, 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(argv[0], argv);
+ bb_perror_msg_and_die("exec %s", argv[0]);
+ }
+}
+
int openvt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int openvt_main(int argc, char **argv)
+int openvt_main(int argc ATTRIBUTE_UNUSED, char **argv)
{
- char vtname[sizeof(VC_FORMAT) + 2];
+ char vtname[sizeof(VC_FORMAT) + sizeof(int)*3];
+ 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),
+ };
- if (argc < 3)
- bb_show_usage();
+ /* "+" - stop on first non-option */
+ flags = getopt32(argv, "+c:wslfv", &str_c);
+ argv += optind;
- /* check for illegal vt number: < 1 or > 63 */
- sprintf(vtname, VC_FORMAT, (int)xatou_range(argv[1], 1, 63));
+ if (flags & OPT_c) {
+ /* Check for illegal vt number: < 1 or > 63 */
+ vtno = xatou_range(str_c, 1, 63);
+ } else {
+ vtno = find_free_vtno();
+ }
- bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS, argv);
- /* grab new one */
+ /* 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(0);
+ /*setsid(); - BAD IDEA: after we exit, child is SIGHUPed... */
xopen(vtname, O_RDWR);
+
+ if (flags & OPT_s) {
+ xioctl(0, VT_ACTIVATE, (void*)(ptrdiff_t)vtno);
+ xioctl(0, VT_WAITACTIVE, (void*)(ptrdiff_t)vtno);
+ }
+
+ if (!argv[0]) {
+ argv--;
+ argv[0] = getenv("SHELL");
+ if (!argv[0])
+ argv[0] = (char *) DEFAULT_SHELL;
+ /*argv[1] = NULL; - already is */
+ }
+
xdup2(0, STDOUT_FILENO);
xdup2(0, STDERR_FILENO);
- argv += 2;
- BB_EXECVP(argv[0], argv);
- _exit(1);
+#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) {
+ wait(NULL);
+// TODO: -ws handling should be here
+ }
+
+ return EXIT_SUCCESS;
}