1 /* 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1991 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * from: @(#)cons.c 7.2 (Berkeley) 5/9/91 39 * $FreeBSD: src/sys/kern/tty_cons.c,v 1.81.2.4 2001/12/17 18:44:41 guido Exp $ 40 * $DragonFly: src/sys/kern/tty_cons.c,v 1.16 2006/07/28 02:17:40 dillon Exp $ 41 */ 42 43 #include "opt_ddb.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/conf.h> 48 #include <sys/cons.h> 49 #include <sys/kernel.h> 50 #include <sys/proc.h> 51 #include <sys/reboot.h> 52 #include <sys/sysctl.h> 53 #include <sys/tty.h> 54 #include <sys/uio.h> 55 #include <sys/msgport.h> 56 #include <sys/msgport2.h> 57 #include <sys/device.h> 58 59 #include <ddb/ddb.h> 60 61 #include <machine/cpu.h> 62 63 static d_open_t cnopen; 64 static d_close_t cnclose; 65 static d_read_t cnread; 66 static d_write_t cnwrite; 67 static d_ioctl_t cnioctl; 68 static d_poll_t cnpoll; 69 static d_kqfilter_t cnkqfilter; 70 71 static int cnintercept(struct dev_generic_args *ap); 72 73 #define CDEV_MAJOR 0 74 static struct dev_ops cn_ops = { 75 { "console", CDEV_MAJOR, D_TTY | D_KQFILTER }, 76 .d_open = cnopen, 77 .d_close = cnclose, 78 .d_read = cnread, 79 .d_write = cnwrite, 80 .d_ioctl = cnioctl, 81 .d_poll = cnpoll, 82 .d_kqfilter = cnkqfilter, 83 }; 84 85 static struct dev_ops cn_iops = { 86 { "intercept", CDEV_MAJOR, D_TTY | D_KQFILTER }, 87 .d_default = cnintercept 88 }; 89 90 static struct dev_ops *cn_fwd_ops; 91 static dev_t cn_dev; 92 static udev_t cn_udev; 93 SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLFLAG_RD, 94 &cn_udev, sizeof cn_udev, "T,dev_t", ""); 95 96 static int cn_mute; 97 98 int cons_unavail = 0; /* XXX: 99 * physical console not available for 100 * input (i.e., it is in graphics mode) 101 */ 102 103 static u_char cn_is_open; /* nonzero if logical console is open */ 104 static int openmode, openflag; /* how /dev/console was openned */ 105 static dev_t cn_devfsdev; /* represents the device private info */ 106 static u_char cn_phys_is_open; /* nonzero if physical device is open */ 107 struct consdev *cn_tab; /* physical console device info */ 108 static u_char console_pausing; /* pause after each line during probe */ 109 static char *console_pausestr= 110 "<pause; press any key to proceed to next line or '.' to end pause mode>"; 111 112 CONS_DRIVER(cons, NULL, NULL, NULL, NULL, NULL, NULL, NULL); 113 SET_DECLARE(cons_set, struct consdev); 114 115 void 116 cninit() 117 { 118 struct consdev *best_cp, *cp, **list; 119 120 /* 121 * Find the first console with the highest priority. 122 */ 123 best_cp = NULL; 124 SET_FOREACH(list, cons_set) { 125 cp = *list; 126 if (cp->cn_probe == NULL) 127 continue; 128 (*cp->cn_probe)(cp); 129 if (cp->cn_pri > CN_DEAD && 130 (best_cp == NULL || cp->cn_pri > best_cp->cn_pri)) 131 best_cp = cp; 132 } 133 134 /* 135 * Check if we should mute the console (for security reasons perhaps) 136 * It can be changes dynamically using sysctl kern.consmute 137 * once we are up and going. 138 * 139 */ 140 cn_mute = ((boothowto & (RB_MUTE 141 |RB_SINGLE 142 |RB_VERBOSE 143 |RB_ASKNAME 144 |RB_CONFIG)) == RB_MUTE); 145 146 /* 147 * If no console, give up. 148 */ 149 if (best_cp == NULL) { 150 if (cn_tab != NULL && cn_tab->cn_term != NULL) 151 (*cn_tab->cn_term)(cn_tab); 152 cn_tab = best_cp; 153 return; 154 } 155 156 /* 157 * Initialize console, then attach to it. This ordering allows 158 * debugging using the previous console, if any. 159 */ 160 (*best_cp->cn_init)(best_cp); 161 if (cn_tab != NULL && cn_tab != best_cp) { 162 /* Turn off the previous console. */ 163 if (cn_tab->cn_term != NULL) 164 (*cn_tab->cn_term)(cn_tab); 165 } 166 if (boothowto & RB_PAUSE) 167 console_pausing = 1; 168 cn_tab = best_cp; 169 } 170 171 /* 172 * Hook the open and close functions on the selected device. 173 */ 174 void 175 cninit_finish() 176 { 177 if ((cn_tab == NULL) || cn_mute) 178 return; 179 180 /* 181 * Hook the open and close functions. XXX bad hack. 182 */ 183 if (dev_is_good(cn_tab->cn_dev)) 184 cn_fwd_ops = dev_ops_intercept(cn_tab->cn_dev, &cn_iops); 185 cn_dev = cn_tab->cn_dev; 186 cn_udev = dev2udev(cn_dev); 187 console_pausing = 0; 188 } 189 190 static void 191 cnuninit(void) 192 { 193 if (cn_tab == NULL) 194 return; 195 196 /* 197 * Unhook the open and close functions. XXX bad hack 198 */ 199 if (cn_fwd_ops) 200 dev_ops_restore(cn_tab->cn_dev, cn_fwd_ops); 201 cn_fwd_ops = NULL; 202 cn_dev = NULL; 203 cn_udev = NOUDEV; 204 } 205 206 /* 207 * User has changed the state of the console muting. 208 * This may require us to open or close the device in question. 209 */ 210 static int 211 sysctl_kern_consmute(SYSCTL_HANDLER_ARGS) 212 { 213 int error; 214 int ocn_mute; 215 216 ocn_mute = cn_mute; 217 error = sysctl_handle_int(oidp, &cn_mute, 0, req); 218 if((error == 0) && (cn_tab != NULL) && (req->newptr != NULL)) { 219 if(ocn_mute && !cn_mute) { 220 /* 221 * going from muted to unmuted.. open the physical dev 222 * if the console has been openned 223 */ 224 cninit_finish(); 225 if (cn_is_open) { 226 /* XXX curproc is not what we want really */ 227 error = dev_dopen(cn_dev, openflag, 228 openmode, curproc->p_ucred); 229 } 230 /* if it failed, back it out */ 231 if ( error != 0) cnuninit(); 232 } else if (!ocn_mute && cn_mute) { 233 /* 234 * going from unmuted to muted.. close the physical dev 235 * if it's only open via /dev/console 236 */ 237 if (cn_is_open) { 238 error = dev_dclose(cn_dev, openflag, 239 openmode); 240 } 241 if (error == 0) 242 cnuninit(); 243 } 244 if (error != 0) { 245 /* 246 * back out the change if there was an error 247 */ 248 cn_mute = ocn_mute; 249 } 250 } 251 return (error); 252 } 253 254 SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW, 255 0, sizeof cn_mute, sysctl_kern_consmute, "I", ""); 256 257 /* 258 * We intercept the OPEN and CLOSE calls on the original device, and 259 * forward the rest through. 260 */ 261 static int 262 cnintercept(struct dev_generic_args *ap) 263 { 264 int error; 265 266 if (ap->a_desc == &dev_open_desc) { 267 error = cnopen((struct dev_open_args *)ap); 268 } else if (ap->a_desc == &dev_close_desc) { 269 error = cnclose((struct dev_close_args *)ap); 270 } else if (cn_fwd_ops) { 271 error = dev_doperate_ops(cn_fwd_ops, ap); 272 } else { 273 error = ENXIO; 274 } 275 return (error); 276 } 277 278 /* 279 * cnopen() is called as an intercept function (dev will be that of the 280 * actual physical device representing our console), and also called from 281 * the muting code and from the /dev/console switch (dev will have the 282 * console's cdevsw). 283 */ 284 static int 285 cnopen(struct dev_open_args *ap) 286 { 287 dev_t dev = ap->a_head.a_dev; 288 int flag = ap->a_oflags; 289 int mode = ap->a_devtype; 290 dev_t cndev, physdev; 291 int retval = 0; 292 293 if (cn_tab == NULL || cn_fwd_ops == NULL) 294 return (0); 295 cndev = cn_tab->cn_dev; 296 physdev = (major(dev) == major(cndev) ? dev : cndev); 297 298 /* 299 * If mute is active, then non console opens don't get here 300 * so we don't need to check for that. They bypass this and go 301 * straight to the device. 302 * 303 * It is important to note that due to our intercept and the fact 304 * that we might be called via the original (intercepted) device, 305 * the original device's ops may point to us, so to avoid an 306 * infinite recursion we have to forward through cn_fwd_ops. 307 * This is a severe hack that really needs to be fixed XXX. 308 * 309 * XXX at the moment we assume that the port forwarding function 310 * is synchronous for open. 311 */ 312 if (!cn_mute) { 313 ap->a_head.a_dev = physdev; 314 retval = dev_doperate_ops(cn_fwd_ops, &ap->a_head); 315 } 316 if (retval == 0) { 317 /* 318 * check if we openned it via /dev/console or 319 * via the physical entry (e.g. /dev/sio0). 320 */ 321 if (dev == cndev) 322 cn_phys_is_open = 1; 323 else if (physdev == cndev) { 324 openmode = mode; 325 openflag = flag; 326 cn_is_open = 1; 327 } 328 dev->si_tty = physdev->si_tty; 329 } 330 return (retval); 331 } 332 333 /* 334 * cnclose() is called as a port intercept function (dev will be that of the 335 * actual physical device representing our console), and also called from 336 * the muting code and from the /dev/console switch (dev will have the 337 * console's cdevsw). 338 */ 339 static int 340 cnclose(struct dev_close_args *ap) 341 { 342 dev_t dev = ap->a_head.a_dev; 343 dev_t cndev; 344 struct tty *cn_tp; 345 346 if (cn_tab == NULL || cn_fwd_ops == NULL) 347 return (0); 348 cndev = cn_tab->cn_dev; 349 cn_tp = cndev->si_tty; 350 /* 351 * act appropriatly depending on whether it's /dev/console 352 * or the pysical device (e.g. /dev/sio) that's being closed. 353 * in either case, don't actually close the device unless 354 * both are closed. 355 */ 356 if (dev == cndev) { 357 /* the physical device is about to be closed */ 358 cn_phys_is_open = 0; 359 if (cn_is_open) { 360 if (cn_tp) { 361 /* perform a ttyhalfclose() */ 362 /* reset session and proc group */ 363 ttyclearsession(cn_tp); 364 } 365 return (0); 366 } 367 } else if (major(dev) != major(cndev)) { 368 /* the logical console is about to be closed */ 369 cn_is_open = 0; 370 if (cn_phys_is_open) 371 return (0); 372 dev = cndev; 373 } 374 if (cn_fwd_ops) { 375 ap->a_head.a_dev = dev; 376 return (dev_doperate_ops(cn_fwd_ops, &ap->a_head)); 377 } 378 return (0); 379 } 380 381 /* 382 * The following functions are dispatched solely from the /dev/console 383 * device. Their job is primarily to forward the request through. 384 * If the console is not attached to anything then write()'s are sunk 385 * to null and reads return 0 (mostly). 386 */ 387 static int 388 cnread(struct dev_read_args *ap) 389 { 390 if (cn_tab == NULL || cn_fwd_ops == NULL) 391 return (0); 392 ap->a_head.a_dev = cn_tab->cn_dev; 393 return (dev_doperate(&ap->a_head)); 394 } 395 396 static int 397 cnwrite(struct dev_write_args *ap) 398 { 399 struct uio *uio = ap->a_uio; 400 dev_t dev; 401 402 if (cn_tab == NULL || cn_fwd_ops == NULL) { 403 uio->uio_resid = 0; /* dump the data */ 404 return (0); 405 } 406 if (constty) 407 dev = constty->t_dev; 408 else 409 dev = cn_tab->cn_dev; 410 log_console(uio); 411 ap->a_head.a_dev = dev; 412 return (dev_doperate(&ap->a_head)); 413 } 414 415 static int 416 cnioctl(struct dev_ioctl_args *ap) 417 { 418 int error; 419 420 if (cn_tab == NULL || cn_fwd_ops == NULL) 421 return (0); 422 KKASSERT(curproc != NULL); 423 /* 424 * Superuser can always use this to wrest control of console 425 * output from the "virtual" console. 426 */ 427 if (ap->a_cmd == TIOCCONS && constty) { 428 if (ap->a_cred) { 429 error = suser_cred(ap->a_cred, 0); 430 if (error) 431 return (error); 432 } 433 constty = NULL; 434 return (0); 435 } 436 ap->a_head.a_dev = cn_tab->cn_dev; 437 return (dev_doperate(&ap->a_head)); 438 } 439 440 static int 441 cnpoll(struct dev_poll_args *ap) 442 { 443 if ((cn_tab == NULL) || cn_mute || cn_fwd_ops == NULL) 444 return (1); 445 ap->a_head.a_dev = cn_tab->cn_dev; 446 return (dev_doperate(&ap->a_head)); 447 } 448 449 static int 450 cnkqfilter(struct dev_kqfilter_args *ap) 451 { 452 if ((cn_tab == NULL) || cn_mute || cn_fwd_ops == NULL) 453 return (1); 454 ap->a_head.a_dev = cn_tab->cn_dev; 455 return (dev_doperate(&ap->a_head)); 456 } 457 458 /* 459 * These synchronous functions are primarily used the kernel needs to 460 * access the keyboard (e.g. when running the debugger), or output data 461 * directly to the console. 462 */ 463 int 464 cngetc(void) 465 { 466 int c; 467 if ((cn_tab == NULL) || cn_mute) 468 return (-1); 469 c = (*cn_tab->cn_getc)(cn_tab->cn_dev); 470 if (c == '\r') c = '\n'; /* console input is always ICRNL */ 471 return (c); 472 } 473 474 int 475 cncheckc(void) 476 { 477 if ((cn_tab == NULL) || cn_mute) 478 return (-1); 479 return ((*cn_tab->cn_checkc)(cn_tab->cn_dev)); 480 } 481 482 void 483 cnputc(int c) 484 { 485 char *cp; 486 487 if ((cn_tab == NULL) || cn_mute) 488 return; 489 if (c) { 490 if (c == '\n') 491 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 492 (*cn_tab->cn_putc)(cn_tab->cn_dev, c); 493 #ifdef DDB 494 if (console_pausing && !db_active && (c == '\n')) { 495 #else 496 if (console_pausing && (c == '\n')) { 497 #endif 498 for(cp=console_pausestr; *cp != '\0'; cp++) 499 (*cn_tab->cn_putc)(cn_tab->cn_dev, *cp); 500 if (cngetc() == '.') 501 console_pausing = 0; 502 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 503 for(cp=console_pausestr; *cp != '\0'; cp++) 504 (*cn_tab->cn_putc)(cn_tab->cn_dev, ' '); 505 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 506 } 507 } 508 } 509 510 void 511 cndbctl(int on) 512 { 513 static int refcount; 514 515 if (cn_tab == NULL) 516 return; 517 if (!on) 518 refcount--; 519 if (refcount == 0 && cn_tab->cn_dbctl != NULL) 520 (*cn_tab->cn_dbctl)(cn_tab->cn_dev, on); 521 if (on) 522 refcount++; 523 } 524 525 static void 526 cn_drvinit(void *unused) 527 { 528 dev_ops_add(&cn_ops, 0, 0); 529 cn_devfsdev = make_dev(&cn_ops, 0, UID_ROOT, GID_WHEEL, 530 0600, "console"); 531 } 532 533 SYSINIT(cndev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,cn_drvinit,NULL) 534