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