1 /* $OpenBSD: cons.c,v 1.18 2007/06/17 18:50:58 jasper 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/proc.h> 45 #include <sys/user.h> 46 #include <sys/buf.h> 47 #include <sys/ioctl.h> 48 #include <sys/tty.h> 49 #include <sys/file.h> 50 #include <sys/conf.h> 51 #include <sys/vnode.h> 52 #include <sys/poll.h> 53 54 #include <dev/cons.h> 55 56 struct tty *constty = NULL; /* virtual console output device */ 57 struct consdev *cn_tab; /* physical console device info */ 58 struct vnode *cn_devvp; /* vnode for underlying device. */ 59 60 int 61 cnopen(dev_t dev, int flag, int mode, struct proc *p) 62 { 63 dev_t cndev; 64 65 if (cn_tab == NULL) 66 return (0); 67 68 /* 69 * always open the 'real' console device, so we don't get nailed 70 * later. This follows normal device semantics; they always get 71 * open() calls. 72 */ 73 cndev = cn_tab->cn_dev; 74 if (cndev == NODEV) 75 return (ENXIO); 76 #ifdef DIAGNOSTIC 77 if (cndev == dev) 78 panic("cnopen: recursive"); 79 #endif 80 if (cn_devvp == NULLVP) { 81 /* try to get a reference on its vnode, but fail silently */ 82 cdevvp(cndev, &cn_devvp); 83 } 84 return ((*cdevsw[major(cndev)].d_open)(cndev, flag, mode, p)); 85 } 86 87 int 88 cnclose(dev_t dev, int flag, int mode, struct proc *p) 89 { 90 struct vnode *vp; 91 92 if (cn_tab == NULL) 93 return (0); 94 95 /* 96 * If the real console isn't otherwise open, close it. 97 * If it's otherwise open, don't close it, because that'll 98 * screw up others who have it open. 99 */ 100 dev = cn_tab->cn_dev; 101 if (cn_devvp != NULLVP) { 102 /* release our reference to real dev's vnode */ 103 vrele(cn_devvp); 104 cn_devvp = NULLVP; 105 } 106 if (vfinddev(dev, VCHR, &vp) && vcount(vp)) 107 return (0); 108 return ((*cdevsw[major(dev)].d_close)(dev, flag, mode, p)); 109 } 110 111 int 112 cnread(dev_t dev, struct uio *uio, int flag) 113 { 114 115 /* 116 * If we would redirect input, punt. This will keep strange 117 * things from happening to people who are using the real 118 * console. Nothing should be using /dev/console for 119 * input (except a shell in single-user mode, but then, 120 * one wouldn't TIOCCONS then). 121 */ 122 if (constty != NULL) 123 return 0; 124 else if (cn_tab == NULL) 125 return ENXIO; 126 127 dev = cn_tab->cn_dev; 128 return ((*cdevsw[major(dev)].d_read)(dev, uio, flag)); 129 } 130 131 int 132 cnwrite(dev_t dev, struct uio *uio, int flag) 133 { 134 135 /* 136 * Redirect output, if that's appropriate. 137 * If there's no real console, return ENXIO. 138 */ 139 if (constty != NULL) 140 dev = constty->t_dev; 141 else if (cn_tab == NULL) 142 return ENXIO; 143 else 144 dev = cn_tab->cn_dev; 145 return ((*cdevsw[major(dev)].d_write)(dev, uio, flag)); 146 } 147 148 int 149 cnstop(struct tty *tp, int flag) 150 { 151 return (0); 152 } 153 154 int 155 cnioctl(dev_t dev, u_long cmd, caddr_t data, int flag, 156 struct proc *p) 157 { 158 int error; 159 160 /* 161 * Superuser can always use this to wrest control of console 162 * output from the "virtual" console. 163 */ 164 if (cmd == TIOCCONS && constty != NULL) { 165 error = suser(p, SUSER_NOACCT); 166 if (error) 167 return (error); 168 constty = NULL; 169 return (0); 170 } 171 172 /* 173 * Redirect the ioctl, if that's appropriate. 174 * Note that strange things can happen, if a program does 175 * ioctls on /dev/console, then the console is redirected 176 * out from under it. 177 */ 178 if (constty != NULL) 179 dev = constty->t_dev; 180 else if (cn_tab == NULL) 181 return ENXIO; 182 else 183 dev = cn_tab->cn_dev; 184 return ((*cdevsw[major(dev)].d_ioctl)(dev, cmd, data, flag, p)); 185 } 186 187 /*ARGSUSED*/ 188 int 189 cnpoll(dev_t dev, int rw, struct proc *p) 190 { 191 192 /* 193 * Redirect the poll, if that's appropriate. 194 * I don't want to think of the possible side effects 195 * of console redirection here. 196 */ 197 if (constty != NULL) 198 dev = constty->t_dev; 199 else if (cn_tab == NULL) 200 return POLLERR; 201 else 202 dev = cn_tab->cn_dev; 203 return (ttpoll(cn_tab->cn_dev, rw, p)); 204 } 205 206 207 int 208 cnkqfilter(dev_t dev, struct knote *kn) 209 { 210 211 /* 212 * Redirect output, if that's appropriate. 213 * If there's no real console, return 1. 214 */ 215 if (constty != NULL) 216 dev = constty->t_dev; 217 else if (cn_tab == NULL) 218 return (1); 219 else 220 dev = cn_tab->cn_dev; 221 if (cdevsw[major(dev)].d_flags & D_KQFILTER) 222 return ((*cdevsw[major(dev)].d_kqfilter)(dev, kn)); 223 return (1); 224 } 225 226 int 227 cngetc(void) 228 { 229 230 if (cn_tab == NULL) 231 return (0); 232 return ((*cn_tab->cn_getc)(cn_tab->cn_dev)); 233 } 234 235 void 236 cnputc(int c) 237 { 238 239 if (cn_tab == NULL) 240 return; 241 242 if (c) { 243 (*cn_tab->cn_putc)(cn_tab->cn_dev, c); 244 if (c == '\n') 245 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 246 } 247 } 248 249 void 250 cnpollc(int on) 251 { 252 static int refcount = 0; 253 254 if (cn_tab == NULL) 255 return; 256 if (!on) 257 --refcount; 258 if (refcount == 0) 259 (*cn_tab->cn_pollc)(cn_tab->cn_dev, on); 260 if (on) 261 ++refcount; 262 } 263 264 void 265 nullcnpollc(dev_t dev, int on) 266 { 267 268 } 269 270 void 271 cnbell(u_int pitch, u_int period, u_int volume) 272 { 273 if (cn_tab == NULL || cn_tab->cn_bell == NULL) 274 return; 275 276 (*cn_tab->cn_bell)(cn_tab->cn_dev, pitch, period, volume); 277 } 278