diff options
Diffstat (limited to 'vt.c')
| -rw-r--r-- | vt.c | 178 |
1 files changed, 178 insertions, 0 deletions
@@ -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"); +} |