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 | D_KQFILTER }, 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 | D_KQFILTER }, 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 * Check if we should mute the console (for security reasons perhaps) 126 * It can be changes dynamically using sysctl kern.consmute 127 * once we are up and going. 128 * 129 */ 130 cn_mute = ((boothowto & (RB_MUTE 131 |RB_SINGLE 132 |RB_VERBOSE 133 |RB_ASKNAME 134 |RB_CONFIG)) == RB_MUTE); 135 136 /* 137 * Find the first console with the highest priority. 138 */ 139 best_cp = NULL; 140 SET_FOREACH(list, cons_set) { 141 cp = *list; 142 if (cp->cn_probe == NULL) 143 continue; 144 (*cp->cn_probe)(cp); 145 if (cp->cn_pri > CN_DEAD && cp->cn_probegood && 146 (best_cp == NULL || cp->cn_pri > best_cp->cn_pri)) 147 best_cp = cp; 148 } 149 150 151 /* 152 * If no console, give up. 153 */ 154 if (best_cp == NULL) { 155 if (cn_tab != NULL && cn_tab->cn_term != NULL) 156 (*cn_tab->cn_term)(cn_tab); 157 cn_tab = best_cp; 158 return; 159 } 160 161 /* 162 * Initialize console, then attach to it. This ordering allows 163 * debugging using the previous console, if any. 164 */ 165 (*best_cp->cn_init)(best_cp); 166 if (cn_tab != NULL && cn_tab != best_cp) { 167 /* Turn off the previous console. */ 168 if (cn_tab->cn_term != NULL) 169 (*cn_tab->cn_term)(cn_tab); 170 } 171 if (boothowto & RB_PAUSE) 172 console_pausing = 1; 173 cn_tab = best_cp; 174 } 175 176 177 /* 178 * Hook the open and close functions on the selected device. 179 */ 180 void 181 cninit_finish(void) 182 { 183 if ((cn_tab == NULL) || cn_mute) 184 return; 185 if (cn_tab->cn_dev == NULL) { 186 cn_tab->cn_init_fini(cn_tab); 187 if (cn_tab->cn_dev == NULL) { 188 kprintf("Unable to hook console! cn_tab %p\n", cn_tab); 189 return; 190 } 191 } 192 193 cn_fwd_ops = dev_ops_intercept(cn_tab->cn_dev, &cn_iops); 194 cn_dev = cn_tab->cn_dev; 195 console_pausing = 0; 196 } 197 198 static void 199 cnuninit(void) 200 { 201 if (cn_tab == NULL) 202 return; 203 if (cn_fwd_ops) 204 dev_ops_restore(cn_tab->cn_dev, cn_fwd_ops); 205 cn_fwd_ops = NULL; 206 cn_dev = NULL; 207 } 208 209 210 /* 211 * User has changed the state of the console muting. 212 * This may require us to open or close the device in question. 213 */ 214 static int 215 sysctl_kern_consmute(SYSCTL_HANDLER_ARGS) 216 { 217 int error; 218 int ocn_mute; 219 220 ocn_mute = cn_mute; 221 error = sysctl_handle_int(oidp, &cn_mute, 0, req); 222 if((error == 0) && (cn_tab != NULL) && (req->newptr != NULL)) { 223 if(ocn_mute && !cn_mute) { 224 /* 225 * going from muted to unmuted.. open the physical dev 226 * if the console has been openned 227 */ 228 cninit_finish(); 229 if (cn_is_open) { 230 /* XXX curproc is not what we want really */ 231 error = dev_dopen(cn_dev, openflag, 232 openmode, curproc->p_ucred); 233 } 234 /* if it failed, back it out */ 235 if ( error != 0) cnuninit(); 236 } else if (!ocn_mute && cn_mute) { 237 /* 238 * going from unmuted to muted.. close the physical dev 239 * if it's only open via /dev/console 240 */ 241 if (cn_is_open) { 242 error = dev_dclose(cn_dev, openflag, 243 openmode); 244 } 245 if (error == 0) 246 cnuninit(); 247 } 248 if (error != 0) { 249 /* 250 * back out the change if there was an error 251 */ 252 cn_mute = ocn_mute; 253 } 254 } 255 return (error); 256 } 257 258 SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW, 259 0, sizeof cn_mute, sysctl_kern_consmute, "I", ""); 260 261 262 /* 263 * We intercept the OPEN and CLOSE calls on the original device, and 264 * forward the rest through. 265 */ 266 static int 267 cnintercept(struct dev_generic_args *ap) 268 { 269 int error; 270 271 if (ap->a_desc == &dev_open_desc) { 272 error = cnopen((struct dev_open_args *)ap); 273 } else if (ap->a_desc == &dev_close_desc) { 274 error = cnclose((struct dev_close_args *)ap); 275 } else if (cn_fwd_ops) { 276 error = dev_doperate_ops(cn_fwd_ops, ap); 277 } else { 278 error = ENXIO; 279 } 280 return (error); 281 } 282 283 /* 284 * cnopen() is called as an intercept function (dev will be that of the 285 * actual physical device representing our console), and also called from 286 * the muting code and from the /dev/console switch (dev will have the 287 * console's cdevsw). 288 */ 289 static int 290 cnopen(struct dev_open_args *ap) 291 { 292 cdev_t dev = ap->a_head.a_dev; 293 int flag = ap->a_oflags; 294 int mode = ap->a_devtype; 295 cdev_t cndev; 296 cdev_t physdev; 297 int retval = 0; 298 299 if (cn_tab == NULL || cn_fwd_ops == NULL) 300 return (0); 301 302 cndev = cn_tab->cn_dev; /* actual physical device */ 303 physdev = (dev == cn_devfsdev) ? cndev : dev; 304 305 /* 306 * If mute is active, then non console opens don't get here 307 * so we don't need to check for that. They bypass this and go 308 * straight to the device. 309 * 310 * It is important to note that due to our intercept and the fact 311 * that we might be called via the original (intercepted) device, 312 * the original device's ops may point to us, so to avoid an 313 * infinite recursion we have to forward through cn_fwd_ops. 314 * This is a severe hack that really needs to be fixed XXX. 315 * 316 * XXX at the moment we assume that the port forwarding function 317 * is synchronous for open. 318 */ 319 if (!cn_mute) { 320 ap->a_head.a_dev = physdev; 321 retval = dev_doperate_ops(cn_fwd_ops, &ap->a_head); 322 } 323 if (retval == 0) { 324 /* 325 * check if we openned it via /dev/console or 326 * via the physical entry (e.g. /dev/sio0). 327 */ 328 if (dev == cndev) { 329 cn_phys_is_open = 1; 330 } else if (physdev == cndev) { 331 openmode = mode; 332 openflag = flag; 333 cn_is_open = 1; 334 } 335 dev->si_tty = cndev->si_tty; 336 } 337 return (retval); 338 } 339 340 /* 341 * cnclose() is called as a port intercept function (dev will be that of the 342 * actual physical device representing our console), and also called from 343 * the muting code and from the /dev/console switch (dev will have the 344 * console's cdevsw). 345 */ 346 static int 347 cnclose(struct dev_close_args *ap) 348 { 349 struct tty *cn_tp; 350 cdev_t cndev; 351 cdev_t physdev; 352 cdev_t dev = ap->a_head.a_dev; 353 354 if (cn_tab == NULL || cn_fwd_ops == NULL) 355 return(0); 356 cndev = cn_tab->cn_dev; 357 cn_tp = cndev->si_tty; 358 physdev = (dev == cn_devfsdev) ? cndev : dev; 359 360 /* 361 * act appropriatly depending on whether it's /dev/console 362 * or the pysical device (e.g. /dev/sio) that's being closed. 363 * in either case, don't actually close the device unless 364 * both are closed. 365 */ 366 if (dev == cndev) { 367 /* the physical device is about to be closed */ 368 cn_phys_is_open = 0; 369 if (cn_is_open) { 370 if (cn_tp) { 371 /* perform a ttyhalfclose() */ 372 /* reset session and proc group */ 373 ttyclearsession(cn_tp); 374 } 375 return(0); 376 } 377 } else if (physdev == cndev) { 378 /* the logical console is about to be closed */ 379 cn_is_open = 0; 380 if (cn_phys_is_open) 381 return(0); 382 dev = cndev; 383 } 384 if (cn_fwd_ops) { 385 ap->a_head.a_dev = dev; 386 return (dev_doperate_ops(cn_fwd_ops, &ap->a_head)); 387 } 388 return (0); 389 } 390 391 /* 392 * The following functions are dispatched solely from the /dev/console 393 * device. Their job is primarily to forward the request through. 394 * If the console is not attached to anything then write()'s are sunk 395 * to null and reads return 0 (mostly). 396 */ 397 static int 398 cnread(struct dev_read_args *ap) 399 { 400 if (cn_tab == NULL || cn_fwd_ops == NULL) 401 return (0); 402 ap->a_head.a_dev = cn_tab->cn_dev; 403 return (dev_doperate(&ap->a_head)); 404 } 405 406 static int 407 cnwrite(struct dev_write_args *ap) 408 { 409 struct uio *uio = ap->a_uio; 410 cdev_t dev; 411 412 if (cn_tab == NULL || cn_fwd_ops == NULL) { 413 uio->uio_resid = 0; /* dump the data */ 414 return (0); 415 } 416 if (constty) 417 dev = constty->t_dev; 418 else 419 dev = cn_tab->cn_dev; 420 log_console(uio); 421 ap->a_head.a_dev = dev; 422 return (dev_doperate(&ap->a_head)); 423 } 424 425 static int 426 cnioctl(struct dev_ioctl_args *ap) 427 { 428 int error; 429 430 if (cn_tab == NULL || cn_fwd_ops == NULL) 431 return (0); 432 KKASSERT(curproc != NULL); 433 /* 434 * Superuser can always use this to wrest control of console 435 * output from the "virtual" console. 436 */ 437 if (ap->a_cmd == TIOCCONS && constty) { 438 if (ap->a_cred) { 439 error = priv_check_cred(ap->a_cred, PRIV_ROOT, 0); 440 if (error) 441 return (error); 442 } 443 constty = NULL; 444 return (0); 445 } 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 cn_devfsdev = make_only_devfs_dev(&cn_ops, 0, UID_ROOT, GID_WHEEL, 530 0600, "console"); 531 } 532 533 SYSINIT(cndev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,cn_drvinit,NULL) 534