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#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <linux/kd.h>
#include <linux/vt.h>
#include "vt.h"
/* -------------------------------------------------------------------- */
#define CONSOLE_ACTIVE 0
#define CONSOLE_REL_REQ 1
#define CONSOLE_INACTIVE 2
#define CONSOLE_ACQ_REQ 3
int console_visible = 1;
extern int debug;
static int switch_last, tty;
static int console_switch_state = CONSOLE_ACTIVE;
static struct vt_mode vt_mode;
static int orig_vt_no = 0;
static void (*console_redraw)(void);
static void console_switch_signal(int signal)
{
if (signal == SIGUSR1) {
/* release */
console_switch_state = CONSOLE_REL_REQ;
if (debug)
write(2,"vt: SIGUSR1\n",12);
}
if (signal == SIGUSR2) {
/* acquisition */
console_switch_state = CONSOLE_ACQ_REQ;
if (debug)
write(2,"vt: SIGUSR2\n",12);
}
}
static void console_switch_release(void)
{
ioctl(tty, VT_RELDISP, 1);
console_switch_state = CONSOLE_INACTIVE;
if (debug)
write(2,"vt: release\n",12);
}
static void console_switch_acquire(void)
{
ioctl(tty, VT_RELDISP, VT_ACKACQ);
console_switch_state = CONSOLE_ACTIVE;
if (debug)
write(2,"vt: acquire\n",12);
}
int console_switch_init(int tty_fd, void (*redraw)(void))
{
struct sigaction act,old;
tty = tty_fd;
console_redraw = redraw;
memset(&act,0,sizeof(act));
act.sa_handler = console_switch_signal;
sigemptyset(&act.sa_mask);
sigaction(SIGUSR1,&act,&old);
sigaction(SIGUSR2,&act,&old);
if (-1 == ioctl(tty, VT_GETMODE, &vt_mode)) {
perror("ioctl VT_GETMODE");
exit(1);
}
vt_mode.mode = VT_PROCESS;
vt_mode.waitv = 0;
vt_mode.relsig = SIGUSR1;
vt_mode.acqsig = SIGUSR2;
if (-1 == ioctl(tty, VT_SETMODE, &vt_mode)) {
perror("ioctl VT_SETMODE");
exit(1);
}
return 0;
}
int check_console_switch(void)
{
if (switch_last == console_switch_state)
return 0;
switch (console_switch_state) {
case CONSOLE_REL_REQ:
console_switch_release();
case CONSOLE_INACTIVE:
console_visible = 0;
break;
case CONSOLE_ACQ_REQ:
console_switch_acquire();
case CONSOLE_ACTIVE:
console_visible = 1;
console_redraw();
break;
default:
break;
}
switch_last = console_switch_state;
return 1;
}
void console_set_vt(int vtno)
{
struct vt_stat vts;
char vtname[12];
if (vtno < 0) {
if (-1 == ioctl(tty,VT_OPENQRY, &vtno) || vtno == -1) {
perror("ioctl VT_OPENQRY");
exit(1);
}
}
vtno &= 0xff;
sprintf(vtname, "/dev/tty%d", vtno);
chown(vtname, getuid(), getgid());
if (-1 == access(vtname, R_OK | W_OK)) {
fprintf(stderr,"access %s: %s\n",vtname,strerror(errno));
exit(1);
}
switch (fork()) {
case 0:
break;
case -1:
perror("fork");
exit(1);
default:
exit(0);
}
close(tty);
close(0);
close(1);
close(2);
setsid();
open(vtname,O_RDWR);
dup(0);
dup(0);
if (-1 == ioctl(tty,VT_GETSTATE, &vts)) {
perror("ioctl VT_GETSTATE");
exit(1);
}
orig_vt_no = vts.v_active;
if (-1 == ioctl(tty,VT_ACTIVATE, vtno)) {
perror("ioctl VT_ACTIVATE");
exit(1);
}
if (-1 == ioctl(tty,VT_WAITACTIVE, vtno)) {
perror("ioctl VT_WAITACTIVE");
exit(1);
}
}
void console_restore_vt(void)
{
if (!orig_vt_no)
return;
if (ioctl(tty, VT_ACTIVATE, orig_vt_no) < 0)
perror("ioctl VT_ACTIVATE");
if (ioctl(tty, VT_WAITACTIVE, orig_vt_no) < 0)
perror("ioctl VT_WAITACTIVE");
}
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