move console handling to vt.c

1 files changed, 178 insertions, 0 deletions

diff --git a/vt.c b/vt.c
new file mode 100644
index 0000000..75559fb
--- /dev/null
+++ b/vt.c
@@ -0,0 +1,178 @@
+#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");
+}