/* $NetBSD: cons.c,v 1.77 2019/12/06 04:15:38 riastradh 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 __KERNEL_RCSID(0, "$NetBSD: cons.c,v 1.77 2019/12/06 04:15:38 riastradh Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include "nullcons.h" dev_type_open(cnopen); dev_type_close(cnclose); dev_type_read(cnread); dev_type_write(cnwrite); dev_type_ioctl(cnioctl); dev_type_poll(cnpoll); dev_type_kqfilter(cnkqfilter); static bool cn_redirect(dev_t *, int, int *); const struct cdevsw cons_cdevsw = { .d_open = cnopen, .d_close = cnclose, .d_read = cnread, .d_write = cnwrite, .d_ioctl = cnioctl, .d_stop = nostop, .d_tty = notty, .d_poll = cnpoll, .d_mmap = nommap, .d_kqfilter = cnkqfilter, .d_discard = nodiscard, .d_flag = D_TTY }; struct tty *constty = NULL; /* virtual console output device */ struct consdev *cn_tab; /* physical console device info */ struct vnode *cn_devvp[2]; /* vnode for underlying device. */ int cnopen(dev_t dev, int flag, int mode, struct lwp *l) { dev_t cndev; int unit, error; unit = minor(dev); if (unit > 1) return ENODEV; 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 NNULLCONS > 0 if (cndev == NODEV) { nullconsattach(0); } #else /* NNULLCONS > 0 */ if (cndev == NODEV) { /* * This is most likely an error in the console attach * code. Panicking looks better than jumping into nowhere * through cdevsw below.... */ panic("cnopen: no console device"); } #endif /* NNULLCONS > 0 */ if (dev == cndev) { /* * This causes cnopen() to be called recursively, which * is generally a bad thing. It is often caused when * dev == 0 and cn_dev has not been set, but was probably * initialised to 0. */ panic("cnopen: cn_tab->cn_dev == dev"); } if (cn_devvp[unit] != NULLVP) return 0; if ((error = cdevvp(cndev, &cn_devvp[unit])) != 0) printf("cnopen: unable to get vnode reference\n"); error = vn_lock(cn_devvp[unit], LK_EXCLUSIVE | LK_RETRY); if (error == 0) { error = VOP_OPEN(cn_devvp[unit], flag, kauth_cred_get()); VOP_UNLOCK(cn_devvp[unit]); } return error; } int cnclose(dev_t dev, int flag, int mode, struct lwp *l) { struct vnode *vp; int unit, error; unit = minor(dev); if (cn_tab == NULL) return (0); vp = cn_devvp[unit]; cn_devvp[unit] = NULL; error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); if (error == 0) { error = VOP_CLOSE(vp, flag, kauth_cred_get()); VOP_UNLOCK(vp); vrele(vp); } return error; } int cnread(dev_t dev, struct uio *uio, int flag) { int error; /* * 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 (!cn_redirect(&dev, 1, &error)) return error; return cdev_read(dev, uio, flag); } int cnwrite(dev_t dev, struct uio *uio, int flag) { int error; /* Redirect output, if that's appropriate. */ if (!cn_redirect(&dev, 0, &error)) return error; return cdev_write(dev, uio, flag); } int cnioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) { int error; error = 0; /* * Superuser can always use this to wrest control of console * output from the "virtual" console. */ if (cmd == TIOCCONS && constty != NULL) { error = kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_VIRTUAL, constty); if (!error) constty = NULL; return (error); } /* * 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 (!cn_redirect(&dev, 0, &error)) return error; return cdev_ioctl(dev, cmd, data, flag, l); } /*ARGSUSED*/ int cnpoll(dev_t dev, int events, struct lwp *l) { int error; /* * Redirect the poll, if that's appropriate. * I don't want to think of the possible side effects * of console redirection here. */ if (!cn_redirect(&dev, 0, &error)) return POLLHUP; return cdev_poll(dev, events, l); } /*ARGSUSED*/ int cnkqfilter(dev_t dev, struct knote *kn) { int error; /* * Redirect the kqfilter, if that's appropriate. * I don't want to think of the possible side effects * of console redirection here. */ if (!cn_redirect(&dev, 0, &error)) return error; return cdev_kqfilter(dev, kn); } int cngetc(void) { if (cn_tab == NULL) return (0); int s = splhigh(); for (;;) { const int rv = (*cn_tab->cn_getc)(cn_tab->cn_dev); if (rv >= 0) { splx(s); return rv; } docritpollhooks(); } } int cngetsn(char *cp, int size) { char *lp; int c, len; cnpollc(1); lp = cp; len = 0; for (;;) { c = cngetc(); switch (c) { case '\n': case '\r': printf("\n"); *lp++ = '\0'; cnpollc(0); return (len); case '\b': case '\177': case '#': if (len) { --len; --lp; printf("\b \b"); } continue; case '@': case 'u'&037: /* CTRL-u */ len = 0; lp = cp; printf("\n"); continue; default: if (len + 1 >= size || c < ' ') { printf("\007"); continue; } printf("%c", c); ++len; *lp++ = c; } } } void cnputc(int c) { if (cn_tab == NULL) return; /* * XXX * for some reason this causes ARCS firmware to output an endless stream of * whitespaces with n32 kernels, so use the pre-1.74 code for now until I can * figure out why this happens */ #ifndef sgimips if (c) { if (c == '\n') { (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); docritpollhooks(); } (*cn_tab->cn_putc)(cn_tab->cn_dev, c); } #else if (c) { (*cn_tab->cn_putc)(cn_tab->cn_dev, c); if (c == '\n') { docritpollhooks(); (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); } } #endif } 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); } void cnflush(void) { if (cn_tab == NULL || cn_tab->cn_flush == NULL) return; (*cn_tab->cn_flush)(cn_tab->cn_dev); } void cnhalt(void) { if (cn_tab == NULL || cn_tab->cn_halt == NULL) return; (*cn_tab->cn_halt)(cn_tab->cn_dev); } /* * Redirect output, if that's appropriate. If there's no real console, * return ENXIO. * * Call with tty_mutex held. */ static bool cn_redirect(dev_t *devp, int is_read, int *error) { dev_t dev = *devp; *error = ENXIO; if (constty != NULL && minor(dev) == 0 && (cn_tab == NULL || (cn_tab->cn_pri != CN_REMOTE))) { if (is_read) { *error = 0; return false; } dev = constty->t_dev; } else if (cn_tab == NULL) return false; else dev = cn_tab->cn_dev; *devp = dev; return true; }