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 1.21 2007/05/07 05:21:41 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 static u_char console_pausing; /* pause after each line during probe */ 108 static char *console_pausestr= 109 "<pause; press any key to proceed to next line or '.' to end pause mode>"; 110 111 struct consdev *cn_tab; /* physical console device info */ 112 struct consdev *gdb_tab; /* physical gdb debugger device info */ 113 114 CONS_DRIVER(cons, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL); 115 SET_DECLARE(cons_set, struct consdev); 116 117 void 118 cninit(void) 119 { 120 struct consdev *best_cp, *cp, **list; 121 122 /* 123 * Find the first console with the highest priority. 124 */ 125 best_cp = NULL; 126 SET_FOREACH(list, cons_set) { 127 cp = *list; 128 if (cp->cn_probe == NULL) 129 continue; 130 (*cp->cn_probe)(cp); 131 if (cp->cn_pri > CN_DEAD && cp->cn_probegood && 132 (best_cp == NULL || cp->cn_pri > best_cp->cn_pri)) 133 best_cp = cp; 134 } 135 136 /* 137 * Check if we should mute the console (for security reasons perhaps) 138 * It can be changes dynamically using sysctl kern.consmute 139 * once we are up and going. 140 * 141 */ 142 cn_mute = ((boothowto & (RB_MUTE 143 |RB_SINGLE 144 |RB_VERBOSE 145 |RB_ASKNAME 146 |RB_CONFIG)) == RB_MUTE); 147 148 /* 149 * If no console, give up. 150 */ 151 if (best_cp == NULL) { 152 if (cn_tab != NULL && cn_tab->cn_term != NULL) 153 (*cn_tab->cn_term)(cn_tab); 154 cn_tab = best_cp; 155 return; 156 } 157 158 /* 159 * Initialize console, then attach to it. This ordering allows 160 * debugging using the previous console, if any. 161 */ 162 (*best_cp->cn_init)(best_cp); 163 if (cn_tab != NULL && cn_tab != best_cp) { 164 /* Turn off the previous console. */ 165 if (cn_tab->cn_term != NULL) 166 (*cn_tab->cn_term)(cn_tab); 167 } 168 if (boothowto & RB_PAUSE) 169 console_pausing = 1; 170 cn_tab = best_cp; 171 } 172 173 /* 174 * Hook the open and close functions on the selected device. 175 */ 176 void 177 cninit_finish(void) 178 { 179 if ((cn_tab == NULL) || cn_mute) 180 return; 181 182 if (cn_tab->cn_dev == NULL) { 183 cn_tab->cn_init_fini(cn_tab); 184 } 185 if (cn_tab->cn_dev == NULL) { 186 kprintf("Unable to hook console open and close! cn_tab %p\n", 187 cn_tab); 188 return; 189 } 190 191 /* 192 * Hook the open and close functions. XXX bad hack. 193 */ 194 if (dev_is_good(cn_tab->cn_dev)) { 195 cn_fwd_ops = dev_ops_intercept(cn_tab->cn_dev, &cn_iops); 196 } 197 cn_dev = cn_tab->cn_dev; 198 cn_udev = dev2udev(cn_dev); 199 console_pausing = 0; 200 } 201 202 static void 203 cnuninit(void) 204 { 205 if (cn_tab == NULL) 206 return; 207 208 /* 209 * Unhook the open and close functions. XXX bad hack 210 */ 211 if (cn_fwd_ops) 212 dev_ops_restore(cn_tab->cn_dev, cn_fwd_ops); 213 cn_fwd_ops = NULL; 214 cn_dev = NULL; 215 cn_udev = NOUDEV; 216 } 217 218 /* 219 * User has changed the state of the console muting. 220 * This may require us to open or close the device in question. 221 */ 222 static int 223 sysctl_kern_consmute(SYSCTL_HANDLER_ARGS) 224 { 225 int error; 226 int ocn_mute; 227 228 ocn_mute = cn_mute; 229 error = sysctl_handle_int(oidp, &cn_mute, 0, req); 230 if((error == 0) && (cn_tab != NULL) && (req->newptr != NULL)) { 231 if(ocn_mute && !cn_mute) { 232 /* 233 * going from muted to unmuted.. open the physical dev 234 * if the console has been openned 235 */ 236 cninit_finish(); 237 if (cn_is_open) { 238 /* XXX curproc is not what we want really */ 239 error = dev_dopen(cn_dev, openflag, 240 openmode, curproc->p_ucred); 241 } 242 /* if it failed, back it out */ 243 if ( error != 0) cnuninit(); 244 } else if (!ocn_mute && cn_mute) { 245 /* 246 * going from unmuted to muted.. close the physical dev 247 * if it's only open via /dev/console 248 */ 249 if (cn_is_open) { 250 error = dev_dclose(cn_dev, openflag, 251 openmode); 252 } 253 if (error == 0) 254 cnuninit(); 255 } 256 if (error != 0) { 257 /* 258 * back out the change if there was an error 259 */ 260 cn_mute = ocn_mute; 261 } 262 } 263 return (error); 264 } 265 266 SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW, 267 0, sizeof cn_mute, sysctl_kern_consmute, "I", ""); 268 269 /* 270 * We intercept the OPEN and CLOSE calls on the original device, and 271 * forward the rest through. 272 */ 273 static int 274 cnintercept(struct dev_generic_args *ap) 275 { 276 int error; 277 278 if (ap->a_desc == &dev_open_desc) { 279 error = cnopen((struct dev_open_args *)ap); 280 } else if (ap->a_desc == &dev_close_desc) { 281 error = cnclose((struct dev_close_args *)ap); 282 } else if (cn_fwd_ops) { 283 error = dev_doperate_ops(cn_fwd_ops, ap); 284 } else { 285 error = ENXIO; 286 } 287 return (error); 288 } 289 290 /* 291 * cnopen() is called as an intercept function (dev will be that of the 292 * actual physical device representing our console), and also called from 293 * the muting code and from the /dev/console switch (dev will have the 294 * console's cdevsw). 295 */ 296 static int 297 cnopen(struct dev_open_args *ap) 298 { 299 cdev_t dev = ap->a_head.a_dev; 300 int flag = ap->a_oflags; 301 int mode = ap->a_devtype; 302 cdev_t cndev, physdev; 303 int retval = 0; 304 305 if (cn_tab == NULL || cn_fwd_ops == NULL) 306 return (0); 307 cndev = cn_tab->cn_dev; 308 physdev = (major(dev) == major(cndev) ? dev : cndev); 309 310 /* 311 * If mute is active, then non console opens don't get here 312 * so we don't need to check for that. They bypass this and go 313 * straight to the device. 314 * 315 * It is important to note that due to our intercept and the fact 316 * that we might be called via the original (intercepted) device, 317 * the original device's ops may point to us, so to avoid an 318 * infinite recursion we have to forward through cn_fwd_ops. 319 * This is a severe hack that really needs to be fixed XXX. 320 * 321 * XXX at the moment we assume that the port forwarding function 322 * is synchronous for open. 323 */ 324 if (!cn_mute) { 325 ap->a_head.a_dev = physdev; 326 retval = dev_doperate_ops(cn_fwd_ops, &ap->a_head); 327 } 328 if (retval == 0) { 329 /* 330 * check if we openned it via /dev/console or 331 * via the physical entry (e.g. /dev/sio0). 332 */ 333 if (dev == cndev) 334 cn_phys_is_open = 1; 335 else if (physdev == cndev) { 336 openmode = mode; 337 openflag = flag; 338 cn_is_open = 1; 339 } 340 dev->si_tty = physdev->si_tty; 341 } 342 return (retval); 343 } 344 345 /* 346 * cnclose() is called as a port intercept function (dev will be that of the 347 * actual physical device representing our console), and also called from 348 * the muting code and from the /dev/console switch (dev will have the 349 * console's cdevsw). 350 */ 351 static int 352 cnclose(struct dev_close_args *ap) 353 { 354 cdev_t dev = ap->a_head.a_dev; 355 cdev_t cndev; 356 struct tty *cn_tp; 357 358 if (cn_tab == NULL || cn_fwd_ops == NULL) 359 return (0); 360 cndev = cn_tab->cn_dev; 361 cn_tp = cndev->si_tty; 362 /* 363 * act appropriatly depending on whether it's /dev/console 364 * or the pysical device (e.g. /dev/sio) that's being closed. 365 * in either case, don't actually close the device unless 366 * both are closed. 367 */ 368 if (dev == cndev) { 369 /* the physical device is about to be closed */ 370 cn_phys_is_open = 0; 371 if (cn_is_open) { 372 if (cn_tp) { 373 /* perform a ttyhalfclose() */ 374 /* reset session and proc group */ 375 ttyclearsession(cn_tp); 376 } 377 return (0); 378 } 379 } else if (major(dev) != major(cndev)) { 380 /* the logical console is about to be closed */ 381 cn_is_open = 0; 382 if (cn_phys_is_open) 383 return (0); 384 dev = cndev; 385 } 386 if (cn_fwd_ops) { 387 ap->a_head.a_dev = dev; 388 return (dev_doperate_ops(cn_fwd_ops, &ap->a_head)); 389 } 390 return (0); 391 } 392 393 /* 394 * The following functions are dispatched solely from the /dev/console 395 * device. Their job is primarily to forward the request through. 396 * If the console is not attached to anything then write()'s are sunk 397 * to null and reads return 0 (mostly). 398 */ 399 static int 400 cnread(struct dev_read_args *ap) 401 { 402 if (cn_tab == NULL || cn_fwd_ops == NULL) 403 return (0); 404 ap->a_head.a_dev = cn_tab->cn_dev; 405 return (dev_doperate(&ap->a_head)); 406 } 407 408 static int 409 cnwrite(struct dev_write_args *ap) 410 { 411 struct uio *uio = ap->a_uio; 412 cdev_t dev; 413 414 if (cn_tab == NULL || cn_fwd_ops == NULL) { 415 uio->uio_resid = 0; /* dump the data */ 416 return (0); 417 } 418 if (constty) 419 dev = constty->t_dev; 420 else 421 dev = cn_tab->cn_dev; 422 log_console(uio); 423 ap->a_head.a_dev = dev; 424 return (dev_doperate(&ap->a_head)); 425 } 426 427 static int 428 cnioctl(struct dev_ioctl_args *ap) 429 { 430 int error; 431 432 if (cn_tab == NULL || cn_fwd_ops == NULL) 433 return (0); 434 KKASSERT(curproc != NULL); 435 /* 436 * Superuser can always use this to wrest control of console 437 * output from the "virtual" console. 438 */ 439 if (ap->a_cmd == TIOCCONS && constty) { 440 if (ap->a_cred) { 441 error = suser_cred(ap->a_cred, 0); 442 if (error) 443 return (error); 444 } 445 constty = NULL; 446 return (0); 447 } 448 ap->a_head.a_dev = cn_tab->cn_dev; 449 return (dev_doperate(&ap->a_head)); 450 } 451 452 static int 453 cnpoll(struct dev_poll_args *ap) 454 { 455 if ((cn_tab == NULL) || cn_mute || cn_fwd_ops == NULL) 456 return (1); 457 ap->a_head.a_dev = cn_tab->cn_dev; 458 return (dev_doperate(&ap->a_head)); 459 } 460 461 static int 462 cnkqfilter(struct dev_kqfilter_args *ap) 463 { 464 if ((cn_tab == NULL) || cn_mute || cn_fwd_ops == NULL) 465 return (1); 466 ap->a_head.a_dev = cn_tab->cn_dev; 467 return (dev_doperate(&ap->a_head)); 468 } 469 470 /* 471 * These synchronous functions are primarily used the kernel needs to 472 * access the keyboard (e.g. when running the debugger), or output data 473 * directly to the console. 474 */ 475 int 476 cngetc(void) 477 { 478 int c; 479 if ((cn_tab == NULL) || cn_mute) 480 return (-1); 481 c = (*cn_tab->cn_getc)(cn_tab->cn_dev); 482 if (c == '\r') c = '\n'; /* console input is always ICRNL */ 483 return (c); 484 } 485 486 int 487 cncheckc(void) 488 { 489 if ((cn_tab == NULL) || cn_mute) 490 return (-1); 491 return ((*cn_tab->cn_checkc)(cn_tab->cn_dev)); 492 } 493 494 void 495 cnputc(int c) 496 { 497 char *cp; 498 499 if ((cn_tab == NULL) || cn_mute) 500 return; 501 if (c) { 502 if (c == '\n') 503 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 504 (*cn_tab->cn_putc)(cn_tab->cn_dev, c); 505 #ifdef DDB 506 if (console_pausing && !db_active && (c == '\n')) { 507 #else 508 if (console_pausing && (c == '\n')) { 509 #endif 510 for(cp=console_pausestr; *cp != '\0'; cp++) 511 (*cn_tab->cn_putc)(cn_tab->cn_dev, *cp); 512 if (cngetc() == '.') 513 console_pausing = 0; 514 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 515 for(cp=console_pausestr; *cp != '\0'; cp++) 516 (*cn_tab->cn_putc)(cn_tab->cn_dev, ' '); 517 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 518 } 519 } 520 } 521 522 void 523 cndbctl(int on) 524 { 525 static int refcount; 526 527 if (cn_tab == NULL) 528 return; 529 if (!on) 530 refcount--; 531 if (refcount == 0 && cn_tab->cn_dbctl != NULL) 532 (*cn_tab->cn_dbctl)(cn_tab->cn_dev, on); 533 if (on) 534 refcount++; 535 } 536 537 static void 538 cn_drvinit(void *unused) 539 { 540 dev_ops_add(&cn_ops, 0, 0); 541 cn_devfsdev = make_dev(&cn_ops, 0, UID_ROOT, GID_WHEEL, 542 0600, "console"); 543 } 544 545 SYSINIT(cndev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,cn_drvinit,NULL) 546