1 /* $OpenBSD: cons.c,v 1.30 2022/07/02 08:50:41 visa Exp $ */ 2 /* $NetBSD: cons.c,v 1.30 1996/04/08 19:57:30 jonathan Exp $ */ 3 4 /* 5 * Copyright (c) 1988 University of Utah. 6 * Copyright (c) 1990, 1993 7 * The Regents of the University of California. All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * the Systems Programming Group of the University of Utah Computer 11 * Science Department. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * from: Utah $Hdr: cons.c 1.7 92/01/21$ 38 * 39 * @(#)cons.c 8.2 (Berkeley) 1/12/94 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/ioctl.h> 45 #include <sys/tty.h> 46 #include <sys/conf.h> 47 #include <sys/vnode.h> 48 49 #include <dev/cons.h> 50 51 struct tty *constty = NULL; /* virtual console output device */ 52 struct vnode *cn_devvp = NULLVP; /* vnode for underlying device. */ 53 54 int 55 cnopen(dev_t dev, int flag, int mode, struct proc *p) 56 { 57 dev_t cndev; 58 59 if (cn_tab == NULL) 60 return (0); 61 62 /* 63 * always open the 'real' console device, so we don't get nailed 64 * later. This follows normal device semantics; they always get 65 * open() calls. 66 */ 67 cndev = cn_tab->cn_dev; 68 if (cndev == NODEV) 69 return (ENXIO); 70 #ifdef DIAGNOSTIC 71 if (cndev == dev) 72 panic("cnopen: recursive"); 73 #endif 74 if (cn_devvp == NULLVP) { 75 /* try to get a reference on its vnode, but fail silently */ 76 cdevvp(cndev, &cn_devvp); 77 } 78 return ((*cdevsw[major(cndev)].d_open)(cndev, flag, mode, p)); 79 } 80 81 int 82 cnclose(dev_t dev, int flag, int mode, struct proc *p) 83 { 84 struct vnode *vp; 85 86 if (cn_tab == NULL) 87 return (0); 88 89 /* 90 * If the real console isn't otherwise open, close it. 91 * If it's otherwise open, don't close it, because that'll 92 * screw up others who have it open. 93 */ 94 dev = cn_tab->cn_dev; 95 if (cn_devvp != NULLVP) { 96 /* release our reference to real dev's vnode */ 97 vrele(cn_devvp); 98 cn_devvp = NULLVP; 99 } 100 if (vfinddev(dev, VCHR, &vp) && vcount(vp)) 101 return (0); 102 return ((*cdevsw[major(dev)].d_close)(dev, flag, mode, p)); 103 } 104 105 int 106 cnread(dev_t dev, struct uio *uio, int flag) 107 { 108 109 /* 110 * If we would redirect input, punt. This will keep strange 111 * things from happening to people who are using the real 112 * console. Nothing should be using /dev/console for 113 * input (except a shell in single-user mode, but then, 114 * one wouldn't TIOCCONS then). 115 */ 116 if (constty != NULL) 117 return 0; 118 else if (cn_tab == NULL) 119 return ENXIO; 120 121 dev = cn_tab->cn_dev; 122 return ((*cdevsw[major(dev)].d_read)(dev, uio, flag)); 123 } 124 125 int 126 cnwrite(dev_t dev, struct uio *uio, int flag) 127 { 128 129 /* 130 * Redirect output, if that's appropriate. 131 * If there's no real console, return ENXIO. 132 */ 133 if (constty != NULL) 134 dev = constty->t_dev; 135 else if (cn_tab == NULL) 136 return ENXIO; 137 else 138 dev = cn_tab->cn_dev; 139 return ((*cdevsw[major(dev)].d_write)(dev, uio, flag)); 140 } 141 142 int 143 cnstop(struct tty *tp, int flag) 144 { 145 return (0); 146 } 147 148 int 149 cnioctl(dev_t dev, u_long cmd, caddr_t data, int flag, 150 struct proc *p) 151 { 152 int error; 153 154 /* 155 * Superuser can always use this to wrest control of console 156 * output from the "virtual" console. 157 */ 158 if (cmd == TIOCCONS && constty != NULL) { 159 error = suser(p); 160 if (error) 161 return (error); 162 constty = NULL; 163 return (0); 164 } 165 166 /* 167 * Redirect the ioctl, if that's appropriate. 168 * Note that strange things can happen, if a program does 169 * ioctls on /dev/console, then the console is redirected 170 * out from under it. 171 */ 172 if (constty != NULL) 173 dev = constty->t_dev; 174 else if (cn_tab == NULL) 175 return ENXIO; 176 else 177 dev = cn_tab->cn_dev; 178 return ((*cdevsw[major(dev)].d_ioctl)(dev, cmd, data, flag, p)); 179 } 180 181 int 182 cnkqfilter(dev_t dev, struct knote *kn) 183 { 184 185 /* 186 * Redirect output, if that's appropriate. 187 * If there's no real console, return 1. 188 */ 189 if (constty != NULL) 190 dev = constty->t_dev; 191 else if (cn_tab == NULL) 192 return (ENXIO); 193 else 194 dev = cn_tab->cn_dev; 195 if (cdevsw[major(dev)].d_kqfilter) 196 return ((*cdevsw[major(dev)].d_kqfilter)(dev, kn)); 197 return (EOPNOTSUPP); 198 } 199 200 int 201 cngetc(void) 202 { 203 204 if (cn_tab == NULL) 205 return (0); 206 return ((*cn_tab->cn_getc)(cn_tab->cn_dev)); 207 } 208 209 void 210 cnputc(int c) 211 { 212 213 if (cn_tab == NULL) 214 return; 215 216 if (c) { 217 (*cn_tab->cn_putc)(cn_tab->cn_dev, c); 218 if (c == '\n') 219 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 220 } 221 } 222 223 void 224 cnpollc(int on) 225 { 226 static int refcount = 0; 227 228 if (cn_tab == NULL) 229 return; 230 if (!on) 231 --refcount; 232 if (refcount == 0) 233 (*cn_tab->cn_pollc)(cn_tab->cn_dev, on); 234 if (on) 235 ++refcount; 236 } 237 238 void 239 nullcnpollc(dev_t dev, int on) 240 { 241 242 } 243 244 void 245 cnbell(u_int pitch, u_int period, u_int volume) 246 { 247 if (cn_tab == NULL || cn_tab->cn_bell == NULL) 248 return; 249 250 (*cn_tab->cn_bell)(cn_tab->cn_dev, pitch, period, volume); 251 } 252