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 1.20 2007/01/08 03:33:41 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 cdev_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,udev_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 cdev_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(void) 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(void) 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 } 186 cn_dev = cn_tab->cn_dev; 187 cn_udev = dev2udev(cn_dev); 188 console_pausing = 0; 189 } 190 191 static void 192 cnuninit(void) 193 { 194 if (cn_tab == NULL) 195 return; 196 197 /* 198 * Unhook the open and close functions. XXX bad hack 199 */ 200 if (cn_fwd_ops) 201 dev_ops_restore(cn_tab->cn_dev, cn_fwd_ops); 202 cn_fwd_ops = NULL; 203 cn_dev = NULL; 204 cn_udev = NOUDEV; 205 } 206 207 /* 208 * User has changed the state of the console muting. 209 * This may require us to open or close the device in question. 210 */ 211 static int 212 sysctl_kern_consmute(SYSCTL_HANDLER_ARGS) 213 { 214 int error; 215 int ocn_mute; 216 217 ocn_mute = cn_mute; 218 error = sysctl_handle_int(oidp, &cn_mute, 0, req); 219 if((error == 0) && (cn_tab != NULL) && (req->newptr != NULL)) { 220 if(ocn_mute && !cn_mute) { 221 /* 222 * going from muted to unmuted.. open the physical dev 223 * if the console has been openned 224 */ 225 cninit_finish(); 226 if (cn_is_open) { 227 /* XXX curproc is not what we want really */ 228 error = dev_dopen(cn_dev, openflag, 229 openmode, curproc->p_ucred); 230 } 231 /* if it failed, back it out */ 232 if ( error != 0) cnuninit(); 233 } else if (!ocn_mute && cn_mute) { 234 /* 235 * going from unmuted to muted.. close the physical dev 236 * if it's only open via /dev/console 237 */ 238 if (cn_is_open) { 239 error = dev_dclose(cn_dev, openflag, 240 openmode); 241 } 242 if (error == 0) 243 cnuninit(); 244 } 245 if (error != 0) { 246 /* 247 * back out the change if there was an error 248 */ 249 cn_mute = ocn_mute; 250 } 251 } 252 return (error); 253 } 254 255 SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW, 256 0, sizeof cn_mute, sysctl_kern_consmute, "I", ""); 257 258 /* 259 * We intercept the OPEN and CLOSE calls on the original device, and 260 * forward the rest through. 261 */ 262 static int 263 cnintercept(struct dev_generic_args *ap) 264 { 265 int error; 266 267 if (ap->a_desc == &dev_open_desc) { 268 error = cnopen((struct dev_open_args *)ap); 269 } else if (ap->a_desc == &dev_close_desc) { 270 error = cnclose((struct dev_close_args *)ap); 271 } else if (cn_fwd_ops) { 272 error = dev_doperate_ops(cn_fwd_ops, ap); 273 } else { 274 error = ENXIO; 275 } 276 return (error); 277 } 278 279 /* 280 * cnopen() is called as an intercept function (dev will be that of the 281 * actual physical device representing our console), and also called from 282 * the muting code and from the /dev/console switch (dev will have the 283 * console's cdevsw). 284 */ 285 static int 286 cnopen(struct dev_open_args *ap) 287 { 288 cdev_t dev = ap->a_head.a_dev; 289 int flag = ap->a_oflags; 290 int mode = ap->a_devtype; 291 cdev_t cndev, physdev; 292 int retval = 0; 293 294 if (cn_tab == NULL || cn_fwd_ops == NULL) 295 return (0); 296 cndev = cn_tab->cn_dev; 297 physdev = (major(dev) == major(cndev) ? dev : cndev); 298 299 /* 300 * If mute is active, then non console opens don't get here 301 * so we don't need to check for that. They bypass this and go 302 * straight to the device. 303 * 304 * It is important to note that due to our intercept and the fact 305 * that we might be called via the original (intercepted) device, 306 * the original device's ops may point to us, so to avoid an 307 * infinite recursion we have to forward through cn_fwd_ops. 308 * This is a severe hack that really needs to be fixed XXX. 309 * 310 * XXX at the moment we assume that the port forwarding function 311 * is synchronous for open. 312 */ 313 if (!cn_mute) { 314 ap->a_head.a_dev = physdev; 315 retval = dev_doperate_ops(cn_fwd_ops, &ap->a_head); 316 } 317 if (retval == 0) { 318 /* 319 * check if we openned it via /dev/console or 320 * via the physical entry (e.g. /dev/sio0). 321 */ 322 if (dev == cndev) 323 cn_phys_is_open = 1; 324 else if (physdev == cndev) { 325 openmode = mode; 326 openflag = flag; 327 cn_is_open = 1; 328 } 329 dev->si_tty = physdev->si_tty; 330 } 331 return (retval); 332 } 333 334 /* 335 * cnclose() is called as a port intercept function (dev will be that of the 336 * actual physical device representing our console), and also called from 337 * the muting code and from the /dev/console switch (dev will have the 338 * console's cdevsw). 339 */ 340 static int 341 cnclose(struct dev_close_args *ap) 342 { 343 cdev_t dev = ap->a_head.a_dev; 344 cdev_t cndev; 345 struct tty *cn_tp; 346 347 if (cn_tab == NULL || cn_fwd_ops == NULL) 348 return (0); 349 cndev = cn_tab->cn_dev; 350 cn_tp = cndev->si_tty; 351 /* 352 * act appropriatly depending on whether it's /dev/console 353 * or the pysical device (e.g. /dev/sio) that's being closed. 354 * in either case, don't actually close the device unless 355 * both are closed. 356 */ 357 if (dev == cndev) { 358 /* the physical device is about to be closed */ 359 cn_phys_is_open = 0; 360 if (cn_is_open) { 361 if (cn_tp) { 362 /* perform a ttyhalfclose() */ 363 /* reset session and proc group */ 364 ttyclearsession(cn_tp); 365 } 366 return (0); 367 } 368 } else if (major(dev) != major(cndev)) { 369 /* the logical console is about to be closed */ 370 cn_is_open = 0; 371 if (cn_phys_is_open) 372 return (0); 373 dev = cndev; 374 } 375 if (cn_fwd_ops) { 376 ap->a_head.a_dev = dev; 377 return (dev_doperate_ops(cn_fwd_ops, &ap->a_head)); 378 } 379 return (0); 380 } 381 382 /* 383 * The following functions are dispatched solely from the /dev/console 384 * device. Their job is primarily to forward the request through. 385 * If the console is not attached to anything then write()'s are sunk 386 * to null and reads return 0 (mostly). 387 */ 388 static int 389 cnread(struct dev_read_args *ap) 390 { 391 if (cn_tab == NULL || cn_fwd_ops == NULL) 392 return (0); 393 ap->a_head.a_dev = cn_tab->cn_dev; 394 return (dev_doperate(&ap->a_head)); 395 } 396 397 static int 398 cnwrite(struct dev_write_args *ap) 399 { 400 struct uio *uio = ap->a_uio; 401 cdev_t dev; 402 403 if (cn_tab == NULL || cn_fwd_ops == NULL) { 404 uio->uio_resid = 0; /* dump the data */ 405 return (0); 406 } 407 if (constty) 408 dev = constty->t_dev; 409 else 410 dev = cn_tab->cn_dev; 411 log_console(uio); 412 ap->a_head.a_dev = dev; 413 return (dev_doperate(&ap->a_head)); 414 } 415 416 static int 417 cnioctl(struct dev_ioctl_args *ap) 418 { 419 int error; 420 421 if (cn_tab == NULL || cn_fwd_ops == NULL) 422 return (0); 423 KKASSERT(curproc != NULL); 424 /* 425 * Superuser can always use this to wrest control of console 426 * output from the "virtual" console. 427 */ 428 if (ap->a_cmd == TIOCCONS && constty) { 429 if (ap->a_cred) { 430 error = suser_cred(ap->a_cred, 0); 431 if (error) 432 return (error); 433 } 434 constty = NULL; 435 return (0); 436 } 437 ap->a_head.a_dev = cn_tab->cn_dev; 438 return (dev_doperate(&ap->a_head)); 439 } 440 441 static int 442 cnpoll(struct dev_poll_args *ap) 443 { 444 if ((cn_tab == NULL) || cn_mute || cn_fwd_ops == NULL) 445 return (1); 446 ap->a_head.a_dev = cn_tab->cn_dev; 447 return (dev_doperate(&ap->a_head)); 448 } 449 450 static int 451 cnkqfilter(struct dev_kqfilter_args *ap) 452 { 453 if ((cn_tab == NULL) || cn_mute || cn_fwd_ops == NULL) 454 return (1); 455 ap->a_head.a_dev = cn_tab->cn_dev; 456 return (dev_doperate(&ap->a_head)); 457 } 458 459 /* 460 * These synchronous functions are primarily used the kernel needs to 461 * access the keyboard (e.g. when running the debugger), or output data 462 * directly to the console. 463 */ 464 int 465 cngetc(void) 466 { 467 int c; 468 if ((cn_tab == NULL) || cn_mute) 469 return (-1); 470 c = (*cn_tab->cn_getc)(cn_tab->cn_dev); 471 if (c == '\r') c = '\n'; /* console input is always ICRNL */ 472 return (c); 473 } 474 475 int 476 cncheckc(void) 477 { 478 if ((cn_tab == NULL) || cn_mute) 479 return (-1); 480 return ((*cn_tab->cn_checkc)(cn_tab->cn_dev)); 481 } 482 483 void 484 cnputc(int c) 485 { 486 char *cp; 487 488 if ((cn_tab == NULL) || cn_mute) 489 return; 490 if (c) { 491 if (c == '\n') 492 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 493 (*cn_tab->cn_putc)(cn_tab->cn_dev, c); 494 #ifdef DDB 495 if (console_pausing && !db_active && (c == '\n')) { 496 #else 497 if (console_pausing && (c == '\n')) { 498 #endif 499 for(cp=console_pausestr; *cp != '\0'; cp++) 500 (*cn_tab->cn_putc)(cn_tab->cn_dev, *cp); 501 if (cngetc() == '.') 502 console_pausing = 0; 503 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 504 for(cp=console_pausestr; *cp != '\0'; cp++) 505 (*cn_tab->cn_putc)(cn_tab->cn_dev, ' '); 506 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 507 } 508 } 509 } 510 511 void 512 cndbctl(int on) 513 { 514 static int refcount; 515 516 if (cn_tab == NULL) 517 return; 518 if (!on) 519 refcount--; 520 if (refcount == 0 && cn_tab->cn_dbctl != NULL) 521 (*cn_tab->cn_dbctl)(cn_tab->cn_dev, on); 522 if (on) 523 refcount++; 524 } 525 526 static void 527 cn_drvinit(void *unused) 528 { 529 dev_ops_add(&cn_ops, 0, 0); 530 cn_devfsdev = make_dev(&cn_ops, 0, UID_ROOT, GID_WHEEL, 531 0600, "console"); 532 } 533 534 SYSINIT(cndev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,cn_drvinit,NULL) 535