top: add -m ("memory") option

[oweals/busybox.git] / loginutils / vlock.c

diff --git a/loginutils/vlock.c b/loginutils/vlock.c
index 8e3a1ea4b3a0b1646945816f9cc256405521e660..85f489c2286d1b5574e5a339139be1941c7fb391 100644 (file)
--- a/loginutils/vlock.c
+++ b/loginutils/vlock.c
@@ -1,5 +1,4 @@
 /* vi: set sw=4 ts=4: */
-
 /*
  * vlock implementation for busybox
  *
@@ -16,81 +15,66 @@
 /* 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>
+#include "libbb.h"
 
-enum { vfd = 3 };
-
-/* static unsigned long o_lock_all; */
-
-static void release_vt(int signo)
+static void release_vt(int signo UNUSED_PARAM)
 {
-       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)
+static void acquire_vt(int signo UNUSED_PARAM)
 {
-       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);
-int vlock_main(int argc, char **argv)
+int vlock_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int vlock_main(int argc UNUSED_PARAM, char **argv)
 {
-       sigset_t sig;
-       struct sigaction sa;
        struct vt_mode vtm;
        struct termios term;
        struct termios oterm;
        struct vt_mode ovtm;
-       uid_t uid;
        struct passwd *pw;
 
-       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));
-       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);
-
+       pw = xgetpwuid(getuid());
+       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 */
+       signal_SA_RESTART_empty_mask(SIGUSR1, release_vt);
+       signal_SA_RESTART_empty_mask(SIGUSR2, acquire_vt);
+       /* 2: unmask them */
+       sig_unblock(SIGUSR1);
+       sig_unblock(SIGUSR2);
+
+       /* 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;
@@ -98,7 +82,7 @@ int vlock_main(int argc, char **argv)
        term.c_iflag |= IGNBRK;
        term.c_lflag &= ~ISIG;
        term.c_lflag &= ~(ECHO | ECHOCTL);
-       tcsetattr(STDIN_FILENO, TCSANOW, &term);
+       tcsetattr_stdin_TCSANOW(&term);
 
        do {
                printf("Virtual console%s locked by %s.\n",
@@ -111,7 +95,7 @@ int vlock_main(int argc, char **argv)
                puts("Password incorrect");
        } while (1);
 
-       ioctl(vfd, VT_SETMODE, &ovtm);
-       tcsetattr(STDIN_FILENO, TCSANOW, &oterm);
-       fflush_stdout_and_exit(0);
+       ioctl(STDIN_FILENO, VT_SETMODE, &ovtm);
+       tcsetattr_stdin_TCSANOW(&oterm);
+       fflush_stdout_and_exit(EXIT_SUCCESS);
 }