kern_cons.c revision 29368
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: cons.c,v 1.54 1997/08/08 20:29:47 julian Exp $ 40 */ 41 42#include <sys/param.h> 43#ifdef DEVFS 44#include <sys/devfsext.h> 45#endif /*DEVFS*/ 46#include <sys/systm.h> 47#include <sys/conf.h> 48#include <sys/kernel.h> 49#include <sys/reboot.h> 50#include <sys/sysctl.h> 51#include <sys/proc.h> 52#include <sys/tty.h> 53 54#include <machine/cpu.h> 55#include <machine/cons.h> 56 57/* XXX this should be config(8)ed. */ 58#include "sc.h" 59#include "vt.h" 60#include "sio.h" 61static struct consdev constab[] = { 62#if NSC > 0 63 { sccnprobe, sccninit, sccngetc, sccncheckc, sccnputc }, 64#endif 65#if NVT > 0 66 { pccnprobe, pccninit, pccngetc, pccncheckc, pccnputc }, 67#endif 68#if NSIO > 0 69 { siocnprobe, siocninit, siocngetc, siocncheckc, siocnputc }, 70#endif 71 { 0 }, 72}; 73 74static d_open_t cnopen; 75static d_close_t cnclose; 76static d_read_t cnread; 77static d_write_t cnwrite; 78static d_ioctl_t cnioctl; 79static d_poll_t cnpoll; 80 81#define CDEV_MAJOR 0 82static struct cdevsw cn_cdevsw = 83 { cnopen, cnclose, cnread, cnwrite, /*0*/ 84 cnioctl, nullstop, nullreset, nodevtotty,/* console */ 85 cnpoll, nommap, NULL, "console", NULL, -1 }; 86 87static dev_t cn_dev_t; /* seems to be never really used */ 88SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLTYPE_OPAQUE|CTLFLAG_RD, 89 &cn_dev_t, sizeof cn_dev_t, "T,dev_t", ""); 90 91static int cn_mute; 92 93int cons_unavail = 0; /* XXX: 94 * physical console not available for 95 * input (i.e., it is in graphics mode) 96 */ 97 98static u_char cn_is_open; /* nonzero if logical console is open */ 99static int openmode, openflag; /* how /dev/console was openned */ 100static u_char cn_phys_is_open; /* nonzero if physical device is open */ 101static d_close_t *cn_phys_close; /* physical device close function */ 102static d_open_t *cn_phys_open; /* physical device open function */ 103static struct consdev *cn_tab; /* physical console device info */ 104static struct tty *cn_tp; /* physical console tty struct */ 105#ifdef DEVFS 106static void *cn_devfs_token; /* represents the devfs entry */ 107#endif /* DEVFS */ 108 109void 110cninit() 111{ 112 struct consdev *best_cp, *cp; 113 114 /* 115 * Find the first console with the highest priority. 116 */ 117 best_cp = NULL; 118 for (cp = constab; cp->cn_probe; cp++) { 119 (*cp->cn_probe)(cp); 120 if (cp->cn_pri > CN_DEAD && 121 (best_cp == NULL || cp->cn_pri > best_cp->cn_pri)) 122 best_cp = cp; 123 } 124 125 /* 126 * Check if we should mute the console (for security reasons perhaps) 127 * It can be changes dynamically using sysctl kern.consmute 128 * once we are up and going. 129 * 130 */ 131 cn_mute = ((boothowto & (RB_MUTE 132 |RB_SINGLE 133 |RB_VERBOSE 134 |RB_ASKNAME 135 |RB_CONFIG)) == RB_MUTE); 136 137 /* 138 * If no console, give up. 139 */ 140 if (best_cp == NULL) { 141 cn_tab = best_cp; 142 return; 143 } 144 145 /* 146 * Initialize console, then attach to it. This ordering allows 147 * debugging using the previous console, if any. 148 * XXX if there was a previous console, then its driver should 149 * be informed when we forget about it. 150 */ 151 (*best_cp->cn_init)(best_cp); 152 cn_tab = best_cp; 153} 154 155void 156cninit_finish() 157{ 158 struct cdevsw *cdp; 159 160 if ((cn_tab == NULL) || cn_mute) 161 return; 162 163 /* 164 * Hook the open and close functions. 165 */ 166 cdp = cdevsw[major(cn_tab->cn_dev)]; 167 cn_phys_close = cdp->d_close; 168 cdp->d_close = cnclose; 169 cn_phys_open = cdp->d_open; 170 cdp->d_open = cnopen; 171 cn_tp = (*cdp->d_devtotty)(cn_tab->cn_dev); 172 cn_dev_t = cn_tp->t_dev; 173} 174 175static void 176cnuninit(void) 177{ 178 struct cdevsw *cdp; 179 180 if (cn_tab == NULL) 181 return; 182 183 /* 184 * Unhook the open and close functions. 185 */ 186 cdp = cdevsw[major(cn_tab->cn_dev)]; 187 cdp->d_close = cn_phys_close; 188 cn_phys_close = NULL; 189 cdp->d_open = cn_phys_open; 190 cn_phys_open = NULL; 191 cn_tp = NULL; 192 cn_dev_t = 0; 193} 194 195/* 196 * User has changed the state of the console muting. 197 * This may require us to open or close the device in question. 198 */ 199static int 200sysctl_kern_consmute SYSCTL_HANDLER_ARGS 201{ 202 int error; 203 int ocn_mute; 204 205 ocn_mute = cn_mute; 206 error = sysctl_handle_int(oidp, &cn_mute, 0, req); 207 if((error == 0) && (cn_tab != NULL) && (req->newptr != NULL)) { 208 if(ocn_mute && !cn_mute) { 209 /* 210 * going from muted to unmuted.. open the physical dev 211 * if the console has been openned 212 */ 213 cninit_finish(); 214 if(cn_is_open) 215 /* XXX curproc is not what we want really */ 216 error = cnopen(cn_dev_t, openflag, 217 openmode, curproc); 218 /* if it failed, back it out */ 219 if ( error != 0) cnuninit(); 220 } else if (!ocn_mute && cn_mute) { 221 /* 222 * going from unmuted to muted.. close the physical dev 223 * if it's only open via /dev/console 224 */ 225 if(cn_is_open) 226 error = cnclose(cn_dev_t, openflag, 227 openmode, curproc); 228 if ( error == 0) cnuninit(); 229 } 230 if (error != 0) { 231 /* 232 * back out the change if there was an error 233 */ 234 cn_mute = ocn_mute; 235 } 236 } 237 return (error); 238} 239 240SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW, 241 0, sizeof cn_mute, sysctl_kern_consmute, "I", ""); 242 243static int 244cnopen(dev, flag, mode, p) 245 dev_t dev; 246 int flag, mode; 247 struct proc *p; 248{ 249 dev_t cndev, physdev; 250 int retval = 0; 251 252 if (cn_tab == NULL) 253 return (0); 254 cndev = cn_tab->cn_dev; 255 physdev = (major(dev) == major(cndev) ? dev : cndev); 256 /* 257 * If mute is active, then non console opens don't get here 258 * so we don't need to check for that. They 259 * bypass this and go straight to the device. 260 */ 261 if(!cn_mute) 262 retval = (*cn_phys_open)(physdev, flag, mode, p); 263 if (retval == 0) { 264 /* 265 * check if we openned it via /dev/console or 266 * via the physical entry (e.g. /dev/sio0). 267 */ 268 if (dev == cndev) 269 cn_phys_is_open = 1; 270 else if (physdev == cndev) { 271 openmode = mode; 272 openflag = flag; 273 cn_is_open = 1; 274 } 275 } 276 return (retval); 277} 278 279static int 280cnclose(dev, flag, mode, p) 281 dev_t dev; 282 int flag, mode; 283 struct proc *p; 284{ 285 dev_t cndev; 286 287 if (cn_tab == NULL) 288 return (0); 289 cndev = cn_tab->cn_dev; 290 /* 291 * act appropriatly depending on whether it's /dev/console 292 * or the pysical device (e.g. /dev/sio) that's being closed. 293 * in either case, don't actually close the device unless 294 * both are closed. 295 */ 296 if (dev == cndev) { 297 /* the physical device is about to be closed */ 298 cn_phys_is_open = 0; 299 if (cn_is_open) { 300 if (cn_tp) { 301 /* perform a ttyhalfclose() */ 302 /* reset session and proc group */ 303 cn_tp->t_pgrp = NULL; 304 cn_tp->t_session = NULL; 305 } 306 return (0); 307 } 308 } else if (major(dev) != major(cndev)) { 309 /* the logical console is about to be closed */ 310 cn_is_open = 0; 311 if (cn_phys_is_open) 312 return (0); 313 dev = cndev; 314 } 315 if(cn_phys_close) 316 return ((*cn_phys_close)(dev, flag, mode, p)); 317 return (0); 318} 319 320static int 321cnread(dev, uio, flag) 322 dev_t dev; 323 struct uio *uio; 324 int flag; 325{ 326 if ((cn_tab == NULL) || cn_mute) 327 return (0); 328 dev = cn_tab->cn_dev; 329 return ((*cdevsw[major(dev)]->d_read)(dev, uio, flag)); 330} 331 332static int 333cnwrite(dev, uio, flag) 334 dev_t dev; 335 struct uio *uio; 336 int flag; 337{ 338 if ((cn_tab == NULL) || cn_mute) { 339 uio->uio_resid = 0; /* dump the data */ 340 return (0); 341 } 342 if (constty) 343 dev = constty->t_dev; 344 else 345 dev = cn_tab->cn_dev; 346 return ((*cdevsw[major(dev)]->d_write)(dev, uio, flag)); 347} 348 349static int 350cnioctl(dev, cmd, data, flag, p) 351 dev_t dev; 352 int cmd; 353 caddr_t data; 354 int flag; 355 struct proc *p; 356{ 357 int error; 358 359 if ((cn_tab == NULL) || cn_mute) 360 return (0); 361 /* 362 * Superuser can always use this to wrest control of console 363 * output from the "virtual" console. 364 */ 365 if (cmd == TIOCCONS && constty) { 366 error = suser(p->p_ucred, (u_short *) NULL); 367 if (error) 368 return (error); 369 constty = NULL; 370 return (0); 371 } 372 dev = cn_tab->cn_dev; 373 return ((*cdevsw[major(dev)]->d_ioctl)(dev, cmd, data, flag, p)); 374} 375 376static int 377cnpoll(dev, events, p) 378 dev_t dev; 379 int events; 380 struct proc *p; 381{ 382 if ((cn_tab == NULL) || cn_mute) 383 return (1); 384 385 dev = cn_tab->cn_dev; 386 387 return ((*cdevsw[major(dev)]->d_poll)(dev, events, p)); 388} 389 390int 391cngetc() 392{ 393 int c; 394 if ((cn_tab == NULL) || cn_mute) 395 return (-1); 396 c = (*cn_tab->cn_getc)(cn_tab->cn_dev); 397 if (c == '\r') c = '\n'; /* console input is always ICRNL */ 398 return (c); 399} 400 401int 402cncheckc() 403{ 404 if ((cn_tab == NULL) || cn_mute) 405 return (-1); 406 return ((*cn_tab->cn_checkc)(cn_tab->cn_dev)); 407} 408 409void 410cnputc(c) 411 register int c; 412{ 413 if ((cn_tab == NULL) || cn_mute) 414 return; 415 if (c) { 416 if (c == '\n') 417 (*cn_tab->cn_putc)(cn_tab->cn_dev, '\r'); 418 (*cn_tab->cn_putc)(cn_tab->cn_dev, c); 419 } 420} 421 422static cn_devsw_installed = 0; 423 424static void 425cn_drvinit(void *unused) 426{ 427 dev_t dev; 428 429 if( ! cn_devsw_installed ) { 430 dev = makedev(CDEV_MAJOR,0); 431 cdevsw_add(&dev,&cn_cdevsw,NULL); 432 cn_devsw_installed = 1; 433#ifdef DEVFS 434 cn_devfs_token = devfs_add_devswf(&cn_cdevsw, 0, DV_CHR, 435 UID_ROOT, GID_WHEEL, 0600, 436 "console"); 437#endif 438 } 439} 440 441SYSINIT(cndev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,cn_drvinit,NULL) 442 443 444