kern_cons.c revision 49558
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 * $Id: tty_cons.c,v 1.70 1999/07/24 09:41:06 yokota Exp $ 40 */ 41 42#include "opt_devfs.h" 43 44#include <sys/param.h> 45#ifdef DEVFS 46#include <sys/devfsext.h> 47#endif /*DEVFS*/ 48#include <sys/systm.h> 49#include <sys/conf.h> 50#include <sys/kernel.h> 51#include <sys/reboot.h> 52#include <sys/sysctl.h> 53#include <sys/proc.h> 54#include <sys/tty.h> 55#include <sys/uio.h> 56#include <sys/cons.h> 57 58#include <machine/cpu.h> 59 60static d_open_t cnopen; 61static d_close_t cnclose; 62static d_read_t cnread; 63static d_write_t cnwrite; 64static d_ioctl_t cnioctl; 65static d_poll_t cnpoll; 66 67#define CDEV_MAJOR 0 68static struct cdevsw cn_cdevsw = { 69 /* open */ cnopen, 70 /* close */ cnclose, 71 /* read */ cnread, 72 /* write */ cnwrite, 73 /* ioctl */ cnioctl, 74 /* stop */ nostop, 75 /* reset */ noreset, 76 /* devtotty */ nodevtotty, 77 /* poll */ cnpoll, 78 /* mmap */ nommap, 79 /* strategy */ nostrategy, 80 /* name */ "console", 81 /* parms */ noparms, 82 /* maj */ CDEV_MAJOR, 83 /* dump */ nodump, 84 /* psize */ nopsize, 85 /* flags */ D_TTY, 86 /* maxio */ 0, 87 /* bmaj */ -1 88}; 89 90static dev_t cn_dev_t; /* seems to be never really used */ 91static udev_t cn_udev_t; 92SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLFLAG_RD, 93 &cn_udev_t, sizeof cn_udev_t, "T,dev_t", ""); 94 95static int cn_mute; 96 97int cons_unavail = 0; /* XXX: 98 * physical console not available for 99 * input (i.e., it is in graphics mode) 100 */ 101 102static u_char cn_is_open; /* nonzero if logical console is open */ 103static int openmode, openflag; /* how /dev/console was openned */ 104static u_char cn_phys_is_open; /* nonzero if physical device is open */ 105static d_close_t *cn_phys_close; /* physical device close function */ 106static d_open_t *cn_phys_open; /* physical device open function */ 107static struct consdev *cn_tab; /* physical console device info */ 108static struct tty *cn_tp; /* physical console tty struct */ 109#ifdef DEVFS 110static void *cn_devfs_token; /* represents the devfs entry */ 111#endif /* DEVFS */ 112 113CONS_DRIVER(cons, NULL, NULL, NULL, NULL, NULL, NULL); 114 115void 116cninit() 117{ 118 struct consdev **list, *best_cp, *cp; 119 120 /* 121 * Find the first console with the highest priority. 122 */ 123 best_cp = NULL; 124 list = (struct consdev **)cons_set.ls_items; 125 while ((cp = *list++) != NULL) { 126 if (cp->cn_probe == NULL) 127 continue; 128 (*cp->cn_probe)(cp); 129 if (cp->cn_pri > CN_DEAD && 130 (best_cp == NULL || cp->cn_pri > best_cp->cn_pri)) 131 best_cp = cp; 132 } 133 134 /* 135 * Check if we should mute the console (for security reasons perhaps) 136 * It can be changes dynamically using sysctl kern.consmute 137 * once we are up and going. 138 * 139 */ 140 cn_mute = ((boothowto & (RB_MUTE 141 |RB_SINGLE 142 |RB_VERBOSE 143 |RB_ASKNAME 144 |RB_CONFIG)) == RB_MUTE); 145 146 /* 147 * If no console, give up. 148 */ 149 if (best_cp == NULL) { 150 if (cn_tab != NULL && cn_tab->cn_term != NULL) 151 (*cn_tab->cn_term)(cn_tab); 152 cn_tab = best_cp; 153 return; 154 } 155 156 /* 157 * Initialize console, then attach to it. This ordering allows 158 * debugging using the previous console, if any. 159 */ 160 (*best_cp->cn_init)(best_cp); 161 if (cn_tab != NULL && cn_tab != best_cp) { 162 /* Turn off the previous console. */ 163 if (cn_tab->cn_term != NULL) 164 (*cn_tab->cn_term)(cn_tab); 165 } 166 cn_tab = best_cp; 167} 168 169void 170cninit_finish() 171{ 172 struct cdevsw *cdp; 173 174 if ((cn_tab == NULL) || cn_mute) 175 return; 176 177 /* 178 * Hook the open and close functions. 179 */ 180 cdp = devsw(cn_tab->cn_dev); 181 cn_phys_close = cdp->d_close; 182 cdp->d_close = cnclose; 183 cn_phys_open = cdp->d_open; 184 cdp->d_open = cnopen; 185 cn_tp = (*cdp->d_devtotty)(cn_tab->cn_dev); 186 cn_dev_t = cn_tab->cn_dev; 187 cn_udev_t = dev2udev(cn_dev_t); 188} 189 190static void 191cnuninit(void) 192{ 193 struct cdevsw *cdp; 194 195 if (cn_tab == NULL) 196 return; 197 198 /* 199 * Unhook the open and close functions. 200 */ 201 cdp = devsw(cn_tab->cn_dev); 202 cdp->d_close = cn_phys_close; 203 cn_phys_close = NULL; 204 cdp->d_open = cn_phys_open; 205 cn_phys_open = NULL; 206 cn_tp = NULL; 207 cn_dev_t = NODEV; 208 cn_udev_t = NOUDEV; 209} 210 211/* 212 * User has changed the state of the console muting. 213 * This may require us to open or close the device in question. 214 */ 215static int 216sysctl_kern_consmute SYSCTL_HANDLER_ARGS 217{ 218 int error; 219 int ocn_mute; 220 221 ocn_mute = cn_mute; 222 error = sysctl_handle_int(oidp, &cn_mute, 0, req); 223 if((error == 0) && (cn_tab != NULL) && (req->newptr != NULL)) { 224 if(ocn_mute && !cn_mute) { 225 /* 226 * going from muted to unmuted.. open the physical dev 227 * if the console has been openned 228 */ 229 cninit_finish(); 230 if(cn_is_open) 231 /* XXX curproc is not what we want really */ 232 error = cnopen(cn_dev_t, openflag, 233 openmode, curproc); 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 = cnclose(cn_dev_t, openflag, 243 openmode, curproc); 244 if ( error == 0) cnuninit(); 245 } 246 if (error != 0) { 247 /* 248 * back out the change if there was an error 249 */ 250 cn_mute = ocn_mute; 251 } 252 } 253 return (error); 254} 255 256SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW, 257 0, sizeof cn_mute, sysctl_kern_consmute, "I", ""); 258 259static int 260cnopen(dev, flag, mode, p) 261 dev_t dev; 262 int flag, mode; 263 struct proc *p; 264{ 265 dev_t cndev, physdev; 266 int retval = 0; 267 268 if (cn_tab == NULL) 269 return (0); 270 cndev = cn_tab->cn_dev; 271 physdev = (major(dev) == major(cndev) ? dev : cndev); 272 /* 273 * If mute is active, then non console opens don't get here 274 * so we don't need to check for that. They 275 * bypass this and go straight to the device. 276 */ 277 if(!cn_mute) 278 retval = (*cn_phys_open)(physdev, flag, mode, p); 279 if (retval == 0) { 280 /* 281 * check if we openned it via /dev/console or 282 * via the physical entry (e.g. /dev/sio0). 283 */ 284 if (dev == cndev) 285 cn_phys_is_open = 1; 286 else if (physdev == cndev) { 287 openmode = mode; 288 openflag = flag; 289 cn_is_open = 1; 290 } 291 } 292 return (retval); 293} 294 295static int 296cnclose(dev, flag, mode, p) 297 dev_t dev; 298 int flag, mode; 299 struct proc *p; 300{ 301 dev_t cndev; 302 303 if (cn_tab == NULL) 304 return (0); 305 cndev = cn_tab->cn_dev; 306 /* 307 * act appropriatly depending on whether it's /dev/console 308 * or the pysical device (e.g. /dev/sio) that's being closed. 309 * in either case, don't actually close the device unless 310 * both are closed. 311 */ 312 if (dev == cndev) { 313 /* the physical device is about to be closed */ 314 cn_phys_is_open = 0; 315 if (cn_is_open) { 316 if (cn_tp) { 317 /* perform a ttyhalfclose() */ 318 /* reset session and proc group */ 319 cn_tp->t_pgrp = NULL; 320 cn_tp->t_session = NULL; 321 } 322 return (0); 323 } 324 } else if (major(dev) != major(cndev)) { 325 /* the logical console is about to be closed */ 326 cn_is_open = 0; 327 if (cn_phys_is_open) 328 return (0); 329 dev = cndev; 330 } 331 if(cn_phys_close) 332 return ((*cn_phys_close)(dev, flag, mode, p)); 333 return (0); 334} 335 336static int 337cnread(dev, uio, flag) 338 dev_t dev; 339 struct uio *uio; 340 int flag; 341{ 342 if ((cn_tab == NULL) || cn_mute) 343 return (0); 344 dev = cn_tab->cn_dev; 345 return ((*devsw(dev)->d_read)(dev, uio, flag)); 346} 347 348static int 349cnwrite(dev, uio, flag) 350 dev_t dev; 351 struct uio *uio; 352 int flag; 353{ 354 if ((cn_tab == NULL) || cn_mute) { 355 uio->uio_resid = 0; /* dump the data */ 356 return (0); 357 } 358 if (constty) 359 dev = constty->t_dev; 360 else 361 dev = cn_tab->cn_dev; 362 return ((*devsw(dev)->d_write)(dev, uio, flag)); 363} 364 365static int 366cnioctl(dev, cmd, data, flag, p) 367 dev_t dev; 368 u_long cmd; 369 caddr_t data; 370 int flag; 371 struct proc *p; 372{ 373 int error; 374 375 if ((cn_tab == NULL) || cn_mute) 376 return (0); 377 /* 378 * Superuser can always use this to wrest control of console 379 * output from the "virtual" console. 380 */ 381 if (cmd == TIOCCONS && constty) { 382 error = suser(p); 383 if (error) 384 return (error); 385 constty = NULL; 386 return (0); 387 } 388 dev = cn_tab->cn_dev; 389 return ((*devsw(dev)->d_ioctl)(dev, cmd, data, flag, p)); 390} 391 392static int 393cnpoll(dev, events, p) 394 dev_t dev; 395 int events; 396 struct proc *p; 397{ 398 if ((cn_tab == NULL) || cn_mute) 399 return (1); 400 401 dev = cn_tab->cn_dev; 402 403 return ((*devsw(dev)->d_poll)(dev, events, p)); 404} 405 406int 407cngetc() 408{ 409 int c; 410 if ((cn_tab == NULL) || cn_mute) 411 return (-1); 412 c = (*cn_tab->cn_getc)(cn_tab->cn_dev); 413 if (c == '\r') c = '\n'; /* console input is always ICRNL */ 414 return (c); 415} 416 417int 418cncheckc() 419{ 420 if ((cn_tab == NULL) || cn_mute) 421 return (-1); 422 return ((*cn_tab->cn_checkc)(cn_tab->cn_dev)); 423} 424 425void 426cnputc(c) 427 register int c; 428{ 429 if ((cn_tab == NULL) || cn_mute) 430 return; 431 if (c) { 432 if (c == '\n') 433 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 434 (*cn_tab->cn_putc)(cn_tab->cn_dev, c); 435 } 436} 437 438static void 439cn_drvinit(void *unused) 440{ 441 442 cdevsw_add(&cn_cdevsw); 443#ifdef DEVFS 444 cn_devfs_token = devfs_add_devswf(&cn_cdevsw, 0, DV_CHR, 445 UID_ROOT, GID_WHEEL, 0600, "console"); 446#endif 447} 448 449SYSINIT(cndev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,cn_drvinit,NULL) 450 451 452