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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: @(#)cons.c 7.2 (Berkeley) 5/9/91 35 * $FreeBSD: src/sys/kern/tty_cons.c,v 1.81.2.4 2001/12/17 18:44:41 guido Exp $ 36 */ 37 38 #include "opt_ddb.h" 39 #include "opt_comconsole.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/conf.h> 44 #include <sys/cons.h> 45 #include <sys/kernel.h> 46 #include <sys/proc.h> 47 #include <sys/priv.h> 48 #include <sys/reboot.h> 49 #include <sys/sysctl.h> 50 #include <sys/tty.h> 51 #include <sys/uio.h> 52 #include <sys/msgport.h> 53 #include <sys/msgport2.h> 54 #include <sys/device.h> 55 56 #include <ddb/ddb.h> 57 58 #include <machine/cpu.h> 59 60 static d_open_t cnopen; 61 static d_close_t cnclose; 62 static d_read_t cnread; 63 static d_write_t cnwrite; 64 static d_ioctl_t cnioctl; 65 static d_kqfilter_t cnkqfilter; 66 67 static int cnintercept(struct dev_generic_args *ap); 68 69 #define CDEV_MAJOR 0 70 static struct dev_ops cn_ops = { 71 { "console", 0, D_TTY | D_MPSAFE }, 72 .d_open = cnopen, 73 .d_close = cnclose, 74 .d_read = cnread, 75 .d_write = cnwrite, 76 .d_ioctl = cnioctl, 77 .d_kqfilter = cnkqfilter, 78 }; 79 80 static struct dev_ops cn_iops = { 81 { "intercept", 0, D_TTY | D_MPSAFE }, 82 .d_default = cnintercept 83 }; 84 85 static struct dev_ops *cn_fwd_ops; 86 static cdev_t cn_dev; 87 88 //XXX: get this shit out! (alexh) 89 #if 0 90 SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLFLAG_RD, 91 &cn_udev, sizeof cn_udev, "T,udev_t", ""); 92 #endif 93 94 static int cn_mute; 95 96 #ifdef BREAK_TO_DEBUGGER 97 int break_to_debugger = 1; 98 #else 99 int break_to_debugger = 0; 100 #endif 101 TUNABLE_INT("kern.break_to_debugger", &break_to_debugger); 102 SYSCTL_INT(_kern, OID_AUTO, break_to_debugger, CTLFLAG_RW, 103 &break_to_debugger, 0, ""); 104 105 #ifdef ALT_BREAK_TO_DEBUGGER 106 int alt_break_to_debugger = 1; 107 #else 108 int alt_break_to_debugger = 0; 109 #endif 110 TUNABLE_INT("kern.alt_break_to_debugger", &alt_break_to_debugger); 111 SYSCTL_INT(_kern, OID_AUTO, alt_break_to_debugger, CTLFLAG_RW, 112 &alt_break_to_debugger, 0, ""); 113 114 int cons_unavail = 0; /* XXX: 115 * physical console not available for 116 * input (i.e., it is in graphics mode) 117 */ 118 int sysbeep_enable = 1; 119 120 static u_char cn_is_open; /* nonzero if logical console is open */ 121 static int openmode, openflag; /* how /dev/console was openned */ 122 static cdev_t cn_devfsdev; /* represents the device private info */ 123 static u_char cn_phys_is_open; /* nonzero if physical device is open */ 124 static u_char console_pausing; /* pause after each line during probe */ 125 static char *console_pausestr= 126 "<pause; press any key to proceed to next line or '.' to end pause mode>"; 127 128 struct consdev *cn_tab; /* physical console device info */ 129 struct consdev *gdb_tab; /* physical gdb debugger device info */ 130 131 SYSCTL_INT(_kern, OID_AUTO, sysbeep_enable, CTLFLAG_RW, &sysbeep_enable, 0, ""); 132 static uint32_t console_rdev; 133 SYSCTL_INT(_kern, OID_AUTO, console_rdev, CTLFLAG_RW, 134 &console_rdev, 0, ""); 135 136 CONS_DRIVER(cons, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL); 137 SET_DECLARE(cons_set, struct consdev); 138 139 void 140 cninit(void) 141 { 142 struct consdev *best_cp, *cp, **list; 143 144 /* 145 * Workaround for token acquisition and releases during the 146 * console init. For some reason if lwkt_gettoken()'s mpcount 147 * optimization is turned off the console init blows up. It 148 * might be trying to kprintf() something in the middle of 149 * its init. 150 */ 151 lwkt_gettoken(&tty_token); 152 153 /* 154 * Check if we should mute the console (for security reasons perhaps) 155 * It can be changes dynamically using sysctl kern.consmute 156 * once we are up and going. 157 * 158 */ 159 cn_mute = ((boothowto & (RB_MUTE 160 |RB_SINGLE 161 |RB_VERBOSE 162 |RB_ASKNAME)) == RB_MUTE); 163 164 /* 165 * Find the first console with the highest priority. 166 */ 167 best_cp = NULL; 168 SET_FOREACH(list, cons_set) { 169 cp = *list; 170 if (cp->cn_probe == NULL) 171 continue; 172 (*cp->cn_probe)(cp); 173 if (cp->cn_pri > CN_DEAD && cp->cn_probegood && 174 (best_cp == NULL || cp->cn_pri > best_cp->cn_pri)) 175 best_cp = cp; 176 } 177 178 179 /* 180 * If no console, give up. 181 */ 182 if (best_cp == NULL) { 183 if (cn_tab != NULL && cn_tab->cn_term != NULL) 184 (*cn_tab->cn_term)(cn_tab); 185 goto done; 186 } 187 188 /* 189 * Initialize console, then attach to it. This ordering allows 190 * debugging using the previous console, if any. 191 */ 192 (*best_cp->cn_init)(best_cp); 193 if (cn_tab != NULL && cn_tab != best_cp) { 194 /* Turn off the previous console. */ 195 if (cn_tab->cn_term != NULL) 196 (*cn_tab->cn_term)(cn_tab); 197 } 198 if (boothowto & RB_PAUSE) 199 console_pausing = 1; 200 done: 201 cn_tab = best_cp; 202 203 /* 204 * We can safely release the token after the init is done. 205 * Also assert that the mpcount is still correct or otherwise 206 * the SMP/AP boot will blow up on us. 207 */ 208 lwkt_reltoken(&tty_token); 209 } 210 211 212 /* 213 * Hook the open and close functions on the selected device. 214 */ 215 void 216 cninit_finish(void) 217 { 218 if ((cn_tab == NULL) || cn_mute) 219 return; 220 if (cn_tab->cn_dev == NULL) { 221 cn_tab->cn_init_fini(cn_tab); 222 if (cn_tab->cn_dev == NULL) { 223 kprintf("Unable to hook console! cn_tab %p\n", cn_tab); 224 return; 225 } 226 } 227 228 cn_fwd_ops = dev_ops_intercept(cn_tab->cn_dev, &cn_iops); 229 cn_dev = cn_tab->cn_dev; 230 if (cn_dev) { 231 console_rdev = makeudev(cn_dev->si_umajor, 232 (cn_dev->si_uminor == 255 ? 233 0 : cn_dev->si_uminor)); 234 } else { 235 console_rdev = 0; 236 } 237 console_pausing = 0; 238 } 239 240 static void 241 cnuninit(void) 242 { 243 if (cn_tab == NULL) 244 return; 245 if (cn_fwd_ops) 246 dev_ops_restore(cn_tab->cn_dev, cn_fwd_ops); 247 cn_fwd_ops = NULL; 248 cn_dev = NULL; 249 } 250 251 252 /* 253 * User has changed the state of the console muting. 254 * This may require us to open or close the device in question. 255 */ 256 static int 257 sysctl_kern_consmute(SYSCTL_HANDLER_ARGS) 258 { 259 int error; 260 int ocn_mute; 261 262 ocn_mute = cn_mute; 263 error = sysctl_handle_int(oidp, &cn_mute, 0, req); 264 if((error == 0) && (cn_tab != NULL) && (req->newptr != NULL)) { 265 if(ocn_mute && !cn_mute) { 266 /* 267 * going from muted to unmuted.. open the physical dev 268 * if the console has been openned 269 */ 270 cninit_finish(); 271 if (cn_is_open) { 272 /* XXX curproc is not what we want really */ 273 error = dev_dopen(cn_dev, openflag, 274 openmode, curproc->p_ucred, NULL); 275 } 276 /* if it failed, back it out */ 277 if ( error != 0) cnuninit(); 278 } else if (!ocn_mute && cn_mute) { 279 /* 280 * going from unmuted to muted.. close the physical dev 281 * if it's only open via /dev/console 282 */ 283 if (cn_is_open) { 284 error = dev_dclose(cn_dev, openflag, 285 openmode, NULL); 286 } 287 if (error == 0) 288 cnuninit(); 289 } 290 if (error != 0) { 291 /* 292 * back out the change if there was an error 293 */ 294 cn_mute = ocn_mute; 295 } 296 } 297 return (error); 298 } 299 300 SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW, 301 0, sizeof cn_mute, sysctl_kern_consmute, "I", ""); 302 303 304 /* 305 * We intercept the OPEN and CLOSE calls on the original device, and 306 * forward the rest through. 307 */ 308 static int 309 cnintercept(struct dev_generic_args *ap) 310 { 311 int error; 312 313 if (ap->a_desc == &dev_open_desc) { 314 error = cnopen((struct dev_open_args *)ap); 315 } else if (ap->a_desc == &dev_close_desc) { 316 error = cnclose((struct dev_close_args *)ap); 317 } else if (cn_fwd_ops) { 318 error = dev_doperate_ops(cn_fwd_ops, ap); 319 } else { 320 error = ENXIO; 321 } 322 return (error); 323 } 324 325 /* 326 * cnopen() is called as an intercept function (dev will be that of the 327 * actual physical device representing our console), and also called from 328 * the muting code and from the /dev/console switch (dev will have the 329 * console's cdevsw). 330 */ 331 static int 332 cnopen(struct dev_open_args *ap) 333 { 334 cdev_t dev = ap->a_head.a_dev; 335 int flag = ap->a_oflags; 336 int mode = ap->a_devtype; 337 cdev_t cndev; 338 cdev_t physdev; 339 int retval = 0; 340 341 if (cn_tab == NULL || cn_fwd_ops == NULL) 342 return (0); 343 344 cndev = cn_tab->cn_dev; /* actual physical device */ 345 physdev = (dev == cn_devfsdev) ? cndev : dev; 346 347 /* 348 * If mute is active, then non console opens don't get here 349 * so we don't need to check for that. They bypass this and go 350 * straight to the device. 351 * 352 * It is important to note that due to our intercept and the fact 353 * that we might be called via the original (intercepted) device, 354 * the original device's ops may point to us, so to avoid an 355 * infinite recursion we have to forward through cn_fwd_ops. 356 * This is a severe hack that really needs to be fixed XXX. 357 * 358 * XXX at the moment we assume that the port forwarding function 359 * is synchronous for open. 360 */ 361 if (!cn_mute) { 362 ap->a_head.a_dev = physdev; 363 retval = dev_doperate_ops(cn_fwd_ops, &ap->a_head); 364 } 365 if (retval == 0) { 366 /* 367 * check if we openned it via /dev/console or 368 * via the physical entry (e.g. /dev/sio0). 369 */ 370 if (dev == cndev) { 371 cn_phys_is_open = 1; 372 } else if (physdev == cndev) { 373 openmode = mode; 374 openflag = flag; 375 cn_is_open = 1; 376 } 377 dev->si_tty = cndev->si_tty; 378 } 379 return (retval); 380 } 381 382 /* 383 * cnclose() is called as a port intercept function (dev will be that of the 384 * actual physical device representing our console), and also called from 385 * the muting code and from the /dev/console switch (dev will have the 386 * console's cdevsw). 387 */ 388 static int 389 cnclose(struct dev_close_args *ap) 390 { 391 struct tty *cn_tp; 392 cdev_t cndev; 393 cdev_t physdev; 394 cdev_t dev = ap->a_head.a_dev; 395 396 if (cn_tab == NULL || cn_fwd_ops == NULL) 397 return(0); 398 cndev = cn_tab->cn_dev; 399 cn_tp = cndev->si_tty; 400 physdev = (dev == cn_devfsdev) ? cndev : dev; 401 402 /* 403 * act appropriatly depending on whether it's /dev/console 404 * or the pysical device (e.g. /dev/sio) that's being closed. 405 * in either case, don't actually close the device unless 406 * both are closed. 407 */ 408 if (dev == cndev) { 409 /* the physical device is about to be closed */ 410 cn_phys_is_open = 0; 411 if (cn_is_open) { 412 if (cn_tp) { 413 /* perform a ttyhalfclose() */ 414 /* reset session and proc group */ 415 ttyclearsession(cn_tp); 416 } 417 return(0); 418 } 419 } else if (physdev == cndev) { 420 /* the logical console is about to be closed */ 421 cn_is_open = 0; 422 if (cn_phys_is_open) 423 return(0); 424 dev = cndev; 425 } 426 if (cn_fwd_ops) { 427 ap->a_head.a_dev = dev; 428 return (dev_doperate_ops(cn_fwd_ops, &ap->a_head)); 429 } 430 return (0); 431 } 432 433 /* 434 * The following functions are dispatched solely from the /dev/console 435 * device. Their job is primarily to forward the request through. 436 * If the console is not attached to anything then write()'s are sunk 437 * to null and reads return 0 (mostly). 438 */ 439 static int 440 cnread(struct dev_read_args *ap) 441 { 442 if (cn_tab == NULL || cn_fwd_ops == NULL) 443 return (0); 444 ap->a_head.a_dev = cn_tab->cn_dev; 445 return (dev_doperate(&ap->a_head)); 446 } 447 448 static int 449 cnwrite(struct dev_write_args *ap) 450 { 451 struct uio *uio = ap->a_uio; 452 cdev_t dev; 453 454 if (cn_tab == NULL || cn_fwd_ops == NULL) { 455 uio->uio_resid = 0; /* dump the data */ 456 return (0); 457 } 458 if (constty) 459 dev = constty->t_dev; 460 else 461 dev = cn_tab->cn_dev; 462 log_console(uio); 463 ap->a_head.a_dev = dev; 464 return (dev_doperate(&ap->a_head)); 465 } 466 467 static int 468 cnioctl(struct dev_ioctl_args *ap) 469 { 470 int error; 471 472 if (cn_tab == NULL || cn_fwd_ops == NULL) 473 return (0); 474 KKASSERT(curproc != NULL); 475 /* 476 * Superuser can always use this to wrest control of console 477 * output from the "virtual" console. 478 */ 479 if (ap->a_cmd == TIOCCONS && constty) { 480 if (ap->a_cred) { 481 error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0); 482 if (error) 483 return (error); 484 } 485 constty = NULL; 486 return (0); 487 } 488 ap->a_head.a_dev = cn_tab->cn_dev; 489 return (dev_doperate(&ap->a_head)); 490 } 491 492 static int 493 cnkqfilter(struct dev_kqfilter_args *ap) 494 { 495 if ((cn_tab == NULL) || cn_mute || cn_fwd_ops == NULL) 496 return (1); 497 ap->a_head.a_dev = cn_tab->cn_dev; 498 return (dev_doperate(&ap->a_head)); 499 } 500 501 /* 502 * These synchronous functions are primarily used the kernel needs to 503 * access the keyboard (e.g. when running the debugger), or output data 504 * directly to the console. 505 */ 506 int 507 cngetc(void) 508 { 509 int c; 510 if ((cn_tab == NULL) || cn_mute) 511 return (-1); 512 c = (*cn_tab->cn_getc)(cn_tab->cn_private); 513 if (c == '\r') c = '\n'; /* console input is always ICRNL */ 514 return (c); 515 } 516 517 int 518 cncheckc(void) 519 { 520 if ((cn_tab == NULL) || cn_mute) 521 return (-1); 522 return ((*cn_tab->cn_checkc)(cn_tab->cn_private)); 523 } 524 525 void 526 cnpoll(int on) 527 { 528 if ((cn_tab == NULL) || cn_mute) 529 return; 530 if (cn_tab->cn_poll) 531 ((*cn_tab->cn_poll)(cn_tab->cn_private, on)); 532 } 533 534 void 535 cnputc(int c) 536 { 537 char *cp; 538 539 if ((cn_tab == NULL) || cn_mute) 540 return; 541 if (c) { 542 if (c == '\n') 543 (*cn_tab->cn_putc)(cn_tab->cn_private, '\r'); 544 (*cn_tab->cn_putc)(cn_tab->cn_private, c); 545 #ifdef DDB 546 if (console_pausing && !db_active && (c == '\n')) { 547 #else 548 if (console_pausing && (c == '\n')) { 549 #endif 550 for(cp=console_pausestr; *cp != '\0'; cp++) 551 (*cn_tab->cn_putc)(cn_tab->cn_private, *cp); 552 if (cngetc() == '.') 553 console_pausing = 0; 554 (*cn_tab->cn_putc)(cn_tab->cn_private, '\r'); 555 for(cp=console_pausestr; *cp != '\0'; cp++) 556 (*cn_tab->cn_putc)(cn_tab->cn_private, ' '); 557 (*cn_tab->cn_putc)(cn_tab->cn_private, '\r'); 558 } 559 } 560 } 561 562 void 563 cndbctl(int on) 564 { 565 static int refcount; 566 567 if (cn_tab == NULL) 568 return; 569 if (!on) 570 refcount--; 571 if (refcount == 0 && cn_tab->cn_dbctl != NULL) 572 (*cn_tab->cn_dbctl)(cn_tab->cn_private, on); 573 if (on) 574 refcount++; 575 } 576 577 static void 578 cn_drvinit(void *unused) 579 { 580 cn_devfsdev = make_only_devfs_dev(&cn_ops, 0, UID_ROOT, GID_WHEEL, 581 0600, "console"); 582 } 583 584 SYSINIT(cndev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE + CDEV_MAJOR, cn_drvinit, NULL); 585