cons.c revision 1.63
1 /* $NetBSD: cons.c,v 1.63 2007/03/04 06:01:41 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * the Systems Programming Group of the University of Utah Computer 9 * Science Department. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * from: Utah $Hdr: cons.c 1.7 92/01/21$ 36 * 37 * @(#)cons.c 8.2 (Berkeley) 1/12/94 38 */ 39 40 /* 41 * Copyright (c) 1988 University of Utah. 42 * 43 * This code is derived from software contributed to Berkeley by 44 * the Systems Programming Group of the University of Utah Computer 45 * Science Department. 46 * 47 * Redistribution and use in source and binary forms, with or without 48 * modification, are permitted provided that the following conditions 49 * are met: 50 * 1. Redistributions of source code must retain the above copyright 51 * notice, this list of conditions and the following disclaimer. 52 * 2. Redistributions in binary form must reproduce the above copyright 53 * notice, this list of conditions and the following disclaimer in the 54 * documentation and/or other materials provided with the distribution. 55 * 3. All advertising materials mentioning features or use of this software 56 * must display the following acknowledgement: 57 * This product includes software developed by the University of 58 * California, Berkeley and its contributors. 59 * 4. Neither the name of the University nor the names of its contributors 60 * may be used to endorse or promote products derived from this software 61 * without specific prior written permission. 62 * 63 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 64 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 65 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 66 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 67 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 68 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 69 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 70 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 71 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 72 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 73 * SUCH DAMAGE. 74 * 75 * from: Utah $Hdr: cons.c 1.7 92/01/21$ 76 * 77 * @(#)cons.c 8.2 (Berkeley) 1/12/94 78 */ 79 80 #include <sys/cdefs.h> 81 __KERNEL_RCSID(0, "$NetBSD: cons.c,v 1.63 2007/03/04 06:01:41 christos Exp $"); 82 83 #include <sys/param.h> 84 #include <sys/proc.h> 85 #include <sys/user.h> 86 #include <sys/systm.h> 87 #include <sys/buf.h> 88 #include <sys/ioctl.h> 89 #include <sys/poll.h> 90 #include <sys/tty.h> 91 #include <sys/file.h> 92 #include <sys/conf.h> 93 #include <sys/vnode.h> 94 #include <sys/kauth.h> 95 #include <sys/mutex.h> 96 97 #include <dev/cons.h> 98 99 dev_type_open(cnopen); 100 dev_type_close(cnclose); 101 dev_type_read(cnread); 102 dev_type_write(cnwrite); 103 dev_type_ioctl(cnioctl); 104 dev_type_poll(cnpoll); 105 dev_type_kqfilter(cnkqfilter); 106 107 static const struct cdevsw *cn_redirect(dev_t *, int, int *); 108 109 const struct cdevsw cons_cdevsw = { 110 cnopen, cnclose, cnread, cnwrite, cnioctl, 111 nostop, notty, cnpoll, nommap, cnkqfilter, D_TTY 112 }; 113 114 struct tty *constty = NULL; /* virtual console output device */ 115 struct consdev *cn_tab; /* physical console device info */ 116 struct vnode *cn_devvp[2]; /* vnode for underlying device. */ 117 118 int 119 cnopen(dev_t dev, int flag, int mode, struct lwp *l) 120 { 121 const struct cdevsw *cdev; 122 dev_t cndev; 123 int unit; 124 125 unit = minor(dev); 126 if (unit > 1) 127 return ENODEV; 128 129 if (cn_tab == NULL) 130 return (0); 131 132 /* 133 * always open the 'real' console device, so we don't get nailed 134 * later. This follows normal device semantics; they always get 135 * open() calls. 136 */ 137 cndev = cn_tab->cn_dev; 138 if (cndev == NODEV) { 139 /* 140 * This is most likely an error in the console attach 141 * code. Panicking looks better than jumping into nowhere 142 * through cdevsw below.... 143 */ 144 panic("cnopen: no console device"); 145 } 146 if (dev == cndev) { 147 /* 148 * This causes cnopen() to be called recursively, which 149 * is generally a bad thing. It is often caused when 150 * dev == 0 and cn_dev has not been set, but was probably 151 * initialised to 0. 152 */ 153 panic("cnopen: cn_tab->cn_dev == dev"); 154 } 155 cdev = cdevsw_lookup(cndev); 156 if (cdev == NULL) 157 return (ENXIO); 158 159 if (cn_devvp[unit] == NULLVP) { 160 /* try to get a reference on its vnode, but fail silently */ 161 cdevvp(cndev, &cn_devvp[unit]); 162 } 163 return ((*cdev->d_open)(cndev, flag, mode, l)); 164 } 165 166 int 167 cnclose(dev_t dev, int flag, int mode, struct lwp *l) 168 { 169 const struct cdevsw *cdev; 170 struct vnode *vp; 171 int unit; 172 173 unit = minor(dev); 174 175 if (cn_tab == NULL) 176 return (0); 177 178 /* 179 * If the real console isn't otherwise open, close it. 180 * If it's otherwise open, don't close it, because that'll 181 * screw up others who have it open. 182 */ 183 dev = cn_tab->cn_dev; 184 cdev = cdevsw_lookup(dev); 185 if (cdev == NULL) 186 return (ENXIO); 187 if (cn_devvp[unit] != NULLVP) { 188 /* release our reference to real dev's vnode */ 189 vrele(cn_devvp[unit]); 190 cn_devvp[unit] = NULLVP; 191 } 192 if (vfinddev(dev, VCHR, &vp) && vcount(vp)) 193 return (0); 194 return ((*cdev->d_close)(dev, flag, mode, l)); 195 } 196 197 int 198 cnread(dev_t dev, struct uio *uio, int flag) 199 { 200 const struct cdevsw *cdev; 201 int error; 202 203 /* 204 * If we would redirect input, punt. This will keep strange 205 * things from happening to people who are using the real 206 * console. Nothing should be using /dev/console for 207 * input (except a shell in single-user mode, but then, 208 * one wouldn't TIOCCONS then). 209 */ 210 cdev = cn_redirect(&dev, 1, &error); 211 if (cdev == NULL) 212 return error; 213 return ((*cdev->d_read)(dev, uio, flag)); 214 } 215 216 int 217 cnwrite(dev_t dev, struct uio *uio, int flag) 218 { 219 const struct cdevsw *cdev; 220 int error; 221 222 /* Redirect output, if that's appropriate. */ 223 cdev = cn_redirect(&dev, 0, &error); 224 if (cdev == NULL) 225 return error; 226 227 return ((*cdev->d_write)(dev, uio, flag)); 228 } 229 230 int 231 cnioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l) 232 { 233 const struct cdevsw *cdev; 234 int error; 235 236 error = 0; 237 238 /* 239 * Superuser can always use this to wrest control of console 240 * output from the "virtual" console. 241 */ 242 #ifdef notyet 243 mutex_enter(&tty_mutex); 244 #endif 245 if (cmd == TIOCCONS && constty != NULL) { 246 error = kauth_authorize_generic(l->l_cred, 247 KAUTH_GENERIC_ISSUSER, NULL); 248 if (!error) 249 constty = NULL; 250 #ifdef notyet 251 mutex_exit(&tty_mutex); 252 #endif 253 return (error); 254 } 255 256 /* 257 * Redirect the ioctl, if that's appropriate. 258 * Note that strange things can happen, if a program does 259 * ioctls on /dev/console, then the console is redirected 260 * out from under it. 261 */ 262 cdev = cn_redirect(&dev, 0, &error); 263 #ifdef notyet 264 mutex_exit(&tty_mutex); 265 #endif 266 if (cdev != NULL) 267 error = (*cdev->d_ioctl)(dev, cmd, data, flag, l); 268 return (error); 269 } 270 271 /*ARGSUSED*/ 272 int 273 cnpoll(dev_t dev, int events, struct lwp *l) 274 { 275 const struct cdevsw *cdev; 276 int error; 277 278 /* 279 * Redirect the poll, if that's appropriate. 280 * I don't want to think of the possible side effects 281 * of console redirection here. 282 */ 283 cdev = cn_redirect(&dev, 0, &error); 284 if (cdev == NULL) 285 return POLLHUP; 286 return ((*cdev->d_poll)(dev, events, l)); 287 } 288 289 /*ARGSUSED*/ 290 int 291 cnkqfilter(dev_t dev, struct knote *kn) 292 { 293 const struct cdevsw *cdev; 294 int error; 295 296 /* 297 * Redirect the kqfilter, if that's appropriate. 298 * I don't want to think of the possible side effects 299 * of console redirection here. 300 */ 301 cdev = cn_redirect(&dev, 0, &error); 302 if (cdev == NULL) 303 return error; 304 return ((*cdev->d_kqfilter)(dev, kn)); 305 } 306 307 int 308 cngetc(void) 309 { 310 if (cn_tab == NULL) 311 return (0); 312 return ((*cn_tab->cn_getc)(cn_tab->cn_dev)); 313 } 314 315 int 316 cngetsn(char *cp, int size) 317 { 318 char *lp; 319 int c, len; 320 321 cnpollc(1); 322 323 lp = cp; 324 len = 0; 325 for (;;) { 326 c = cngetc(); 327 switch (c) { 328 case '\n': 329 case '\r': 330 printf("\n"); 331 *lp++ = '\0'; 332 cnpollc(0); 333 return (len); 334 case '\b': 335 case '\177': 336 case '#': 337 if (len) { 338 --len; 339 --lp; 340 printf("\b \b"); 341 } 342 continue; 343 case '@': 344 case 'u'&037: /* CTRL-u */ 345 len = 0; 346 lp = cp; 347 printf("\n"); 348 continue; 349 default: 350 if (len + 1 >= size || c < ' ') { 351 printf("\007"); 352 continue; 353 } 354 printf("%c", c); 355 ++len; 356 *lp++ = c; 357 } 358 } 359 } 360 361 void 362 cnputc(int c) 363 { 364 365 if (cn_tab == NULL) 366 return; 367 368 if (c) { 369 (*cn_tab->cn_putc)(cn_tab->cn_dev, c); 370 if (c == '\n') 371 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 372 } 373 } 374 375 void 376 cnpollc(int on) 377 { 378 static int refcount = 0; 379 380 if (cn_tab == NULL) 381 return; 382 if (!on) 383 --refcount; 384 if (refcount == 0) 385 (*cn_tab->cn_pollc)(cn_tab->cn_dev, on); 386 if (on) 387 ++refcount; 388 } 389 390 void 391 nullcnpollc(dev_t dev, int on) 392 { 393 394 } 395 396 void 397 cnbell(u_int pitch, u_int period, u_int volume) 398 { 399 400 if (cn_tab == NULL || cn_tab->cn_bell == NULL) 401 return; 402 (*cn_tab->cn_bell)(cn_tab->cn_dev, pitch, period, volume); 403 } 404 405 void 406 cnflush(void) 407 { 408 if (cn_tab == NULL || cn_tab->cn_flush == NULL) 409 return; 410 (*cn_tab->cn_flush)(cn_tab->cn_dev); 411 } 412 413 void 414 cnhalt(void) 415 { 416 if (cn_tab == NULL || cn_tab->cn_halt == NULL) 417 return; 418 (*cn_tab->cn_halt)(cn_tab->cn_dev); 419 } 420 421 /* 422 * Redirect output, if that's appropriate. If there's no real console, 423 * return ENXIO. 424 * 425 * Call with tty_mutex held. 426 */ 427 static const struct cdevsw * 428 cn_redirect(dev_t *devp, int is_read, int *error) 429 { 430 dev_t dev = *devp; 431 432 *error = ENXIO; 433 if (constty != NULL && minor(dev) == 0 && 434 (cn_tab == NULL || (cn_tab->cn_pri != CN_REMOTE))) { 435 if (is_read) { 436 *error = 0; 437 return NULL; 438 } 439 dev = constty->t_dev; 440 } else if (cn_tab == NULL) 441 return NULL; 442 else 443 dev = cn_tab->cn_dev; 444 *devp = dev; 445 return cdevsw_lookup(dev); 446 } 447
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