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