/* $OpenBSD: cons.c,v 1.31 2025/09/20 13:53:36 mpi Exp $ */ /* $NetBSD: cons.c,v 1.30 1996/04/08 19:57:30 jonathan Exp $ */ /* * Copyright (c) 1988 University of Utah. * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * the Systems Programming Group of the University of Utah Computer * Science Department. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: Utah $Hdr: cons.c 1.7 92/01/21$ * * @(#)cons.c 8.2 (Berkeley) 1/12/94 */ #include <sys/param.h> #include <sys/systm.h> #include <sys/ioctl.h> #include <sys/tty.h> #include <sys/conf.h> #include <sys/vnode.h> #include <dev/cons.h> struct tty *constty = NULL; /* virtual console output device */ struct vnode *cn_devvp = NULL; /* vnode for underlying device. */ int cnopen(dev_t dev, int flag, int mode, struct proc *p) { dev_t cndev; if (cn_tab == NULL) return (0); /* * always open the 'real' console device, so we don't get nailed * later. This follows normal device semantics; they always get * open() calls. */ cndev = cn_tab->cn_dev; if (cndev == NODEV) return (ENXIO); #ifdef DIAGNOSTIC if (cndev == dev) panic("cnopen: recursive"); #endif if (cn_devvp == NULL) { /* try to get a reference on its vnode, but fail silently */ cdevvp(cndev, &cn_devvp); } return ((*cdevsw[major(cndev)].d_open)(cndev, flag, mode, p)); } int cnclose(dev_t dev, int flag, int mode, struct proc *p) { struct vnode *vp; if (cn_tab == NULL) return (0); /* * If the real console isn't otherwise open, close it. * If it's otherwise open, don't close it, because that'll * screw up others who have it open. */ dev = cn_tab->cn_dev; if (cn_devvp != NULL) { /* release our reference to real dev's vnode */ vrele(cn_devvp); cn_devvp = NULL; } if (vfinddev(dev, VCHR, &vp) && vcount(vp)) return (0); return ((*cdevsw[major(dev)].d_close)(dev, flag, mode, p)); } int cnread(dev_t dev, struct uio *uio, int flag) { /* * If we would redirect input, punt. This will keep strange * things from happening to people who are using the real * console. Nothing should be using /dev/console for * input (except a shell in single-user mode, but then, * one wouldn't TIOCCONS then). */ if (constty != NULL) return 0; else if (cn_tab == NULL) return ENXIO; dev = cn_tab->cn_dev; return ((*cdevsw[major(dev)].d_read)(dev, uio, flag)); } int cnwrite(dev_t dev, struct uio *uio, int flag) { /* * Redirect output, if that's appropriate. * If there's no real console, return ENXIO. */ if (constty != NULL) dev = constty->t_dev; else if (cn_tab == NULL) return ENXIO; else dev = cn_tab->cn_dev; return ((*cdevsw[major(dev)].d_write)(dev, uio, flag)); } int cnstop(struct tty *tp, int flag) { return (0); } int cnioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p) { int error; /* * Superuser can always use this to wrest control of console * output from the "virtual" console. */ if (cmd == TIOCCONS && constty != NULL) { error = suser(p); if (error) return (error); constty = NULL; return (0); } /* * Redirect the ioctl, if that's appropriate. * Note that strange things can happen, if a program does * ioctls on /dev/console, then the console is redirected * out from under it. */ if (constty != NULL) dev = constty->t_dev; else if (cn_tab == NULL) return ENXIO; else dev = cn_tab->cn_dev; return ((*cdevsw[major(dev)].d_ioctl)(dev, cmd, data, flag, p)); } int cnkqfilter(dev_t dev, struct knote *kn) { /* * Redirect output, if that's appropriate. * If there's no real console, return 1. */ if (constty != NULL) dev = constty->t_dev; else if (cn_tab == NULL) return (ENXIO); else dev = cn_tab->cn_dev; if (cdevsw[major(dev)].d_kqfilter) return ((*cdevsw[major(dev)].d_kqfilter)(dev, kn)); return (EOPNOTSUPP); } int cngetc(void) { if (cn_tab == NULL) return (0); return ((*cn_tab->cn_getc)(cn_tab->cn_dev)); } void cnputc(int c) { if (cn_tab == NULL) return; if (c) { (*cn_tab->cn_putc)(cn_tab->cn_dev, c); if (c == '\n') (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); } } void cnpollc(int on) { static int refcount = 0; if (cn_tab == NULL) return; if (!on) --refcount; if (refcount == 0) (*cn_tab->cn_pollc)(cn_tab->cn_dev, on); if (on) ++refcount; } void nullcnpollc(dev_t dev, int on) { } void cnbell(u_int pitch, u_int period, u_int volume) { if (cn_tab == NULL || cn_tab->cn_bell == NULL) return; (*cn_tab->cn_bell)(cn_tab->cn_dev, pitch, period, volume); }
