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Diffstat (limited to 'loginutils/vlock.c')
-rw-r--r--loginutils/vlock.c84
1 files changed, 40 insertions, 44 deletions
diff --git a/loginutils/vlock.c b/loginutils/vlock.c
index 6e928e239..846733ea8 100644
--- a/loginutils/vlock.c
+++ b/loginutils/vlock.c
@@ -1,5 +1,4 @@
/* vi: set sw=4 ts=4: */
-
/*
* vlock implementation for busybox
*
@@ -16,27 +15,25 @@
/* Fixed by Erik Andersen to do passwords the tinylogin way...
* It now works with md5, sha1, etc passwords. */
-#include "libbb.h"
#include <sys/vt.h>
-
-enum { vfd = 3 };
-
-/* static unsigned long o_lock_all; */
+#include "libbb.h"
static void release_vt(int signo)
{
- ioctl(vfd, VT_RELDISP, (unsigned long) !option_mask32 /*!o_lock_all*/);
+ /* If -a, param is 0, which means:
+ * "no, kernel, we don't allow console switch away from us!" */
+ ioctl(STDIN_FILENO, VT_RELDISP, (unsigned long) !option_mask32);
}
static void acquire_vt(int signo)
{
- ioctl(vfd, VT_RELDISP, VT_ACKACQ);
+ /* ACK to kernel that switch to console is successful */
+ ioctl(STDIN_FILENO, VT_RELDISP, VT_ACKACQ);
}
int vlock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int vlock_main(int argc, char **argv)
{
- sigset_t sig;
struct sigaction sa;
struct vt_mode vtm;
struct termios term;
@@ -48,49 +45,48 @@ int vlock_main(int argc, char **argv)
uid = getuid();
pw = getpwuid(uid);
if (pw == NULL)
- bb_error_msg_and_die("unknown uid %d", uid);
-
- if (argc > 2) {
- bb_show_usage();
- }
-
- /*o_lock_all = */getopt32(argv, "a");
-
- /* Avoid using statics - use constant fd */
- xmove_fd(xopen(CURRENT_TTY, O_RDWR), vfd);
- xioctl(vfd, VT_GETMODE, &vtm);
-
- /* mask a bunch of signals */
- sigprocmask(SIG_SETMASK, NULL, &sig);
- sigdelset(&sig, SIGUSR1);
- sigdelset(&sig, SIGUSR2);
- sigaddset(&sig, SIGTSTP);
- sigaddset(&sig, SIGTTIN);
- sigaddset(&sig, SIGTTOU);
- sigaddset(&sig, SIGHUP);
- sigaddset(&sig, SIGCHLD);
- sigaddset(&sig, SIGQUIT);
- sigaddset(&sig, SIGINT);
-
- sigemptyset(&(sa.sa_mask));
+ bb_error_msg_and_die("unknown uid %d", (int)uid);
+
+ opt_complementary = "=0"; /* no params! */
+ getopt32(argv, "a");
+
+ /* Ignore some signals so that we don't get killed by them */
+ bb_signals(0
+ + (1 << SIGTSTP)
+ + (1 << SIGTTIN)
+ + (1 << SIGTTOU)
+ + (1 << SIGHUP )
+ + (1 << SIGCHLD) /* paranoia :) */
+ + (1 << SIGQUIT)
+ + (1 << SIGINT )
+ , SIG_IGN);
+
+ /* We will use SIGUSRx for console switch control: */
+ /* 1: set handlers */
+ sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_RESTART;
sa.sa_handler = release_vt;
sigaction(SIGUSR1, &sa, NULL);
sa.sa_handler = acquire_vt;
sigaction(SIGUSR2, &sa, NULL);
-
- /* need to handle some signals so that we don't get killed by them */
- sa.sa_handler = SIG_IGN;
- sigaction(SIGHUP, &sa, NULL);
- sigaction(SIGQUIT, &sa, NULL);
- sigaction(SIGINT, &sa, NULL);
- sigaction(SIGTSTP, &sa, NULL);
-
+ /* 2: unmask them */
+ sigprocmask(SIG_SETMASK, NULL, &sa.sa_mask);
+ sigdelset(&sa.sa_mask, SIGUSR1);
+ sigdelset(&sa.sa_mask, SIGUSR2);
+ sigprocmask(SIG_SETMASK, &sa.sa_mask, NULL);
+
+ /* Revert stdin/out to our controlling tty
+ * (or die if we have none) */
+ xmove_fd(xopen(CURRENT_TTY, O_RDWR), STDIN_FILENO);
+ xdup2(STDIN_FILENO, STDOUT_FILENO);
+
+ xioctl(STDIN_FILENO, VT_GETMODE, &vtm);
ovtm = vtm;
+ /* "console switches are controlled by us, not kernel!" */
vtm.mode = VT_PROCESS;
vtm.relsig = SIGUSR1;
vtm.acqsig = SIGUSR2;
- ioctl(vfd, VT_SETMODE, &vtm);
+ ioctl(STDIN_FILENO, VT_SETMODE, &vtm);
tcgetattr(STDIN_FILENO, &oterm);
term = oterm;
@@ -111,7 +107,7 @@ int vlock_main(int argc, char **argv)
puts("Password incorrect");
} while (1);
- ioctl(vfd, VT_SETMODE, &ovtm);
+ ioctl(STDIN_FILENO, VT_SETMODE, &ovtm);
tcsetattr(STDIN_FILENO, TCSANOW, &oterm);
fflush_stdout_and_exit(0);
}