kern_cons.c revision 125467
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 */ 40 41#include <sys/cdefs.h> 42__FBSDID("$FreeBSD: head/sys/kern/tty_cons.c 125467 2004-02-05 01:56:43Z kan $"); 43 44#include "opt_ddb.h" 45 46#include <sys/param.h> 47#include <sys/systm.h> 48#include <sys/conf.h> 49#include <sys/cons.h> 50#include <sys/fcntl.h> 51#include <sys/kernel.h> 52#include <sys/malloc.h> 53#include <sys/msgbuf.h> 54#include <sys/namei.h> 55#include <sys/proc.h> 56#include <sys/queue.h> 57#include <sys/reboot.h> 58#include <sys/sysctl.h> 59#include <sys/tty.h> 60#include <sys/uio.h> 61#include <sys/vnode.h> 62 63#include <ddb/ddb.h> 64 65#include <machine/cpu.h> 66 67static d_open_t cnopen; 68static d_close_t cnclose; 69static d_read_t cnread; 70static d_write_t cnwrite; 71static d_ioctl_t cnioctl; 72static d_poll_t cnpoll; 73static d_kqfilter_t cnkqfilter; 74 75static struct cdevsw cn_cdevsw = { 76 .d_open = cnopen, 77 .d_close = cnclose, 78 .d_read = cnread, 79 .d_write = cnwrite, 80 .d_ioctl = cnioctl, 81 .d_poll = cnpoll, 82 .d_name = "console", 83 .d_maj = 256, 84 /* 85 * XXX: We really want major #0, but zero here means 86 * XXX: allocate a major number automatically. 87 * XXX: kern_conf.c knows what to do when it sees 256. 88 */ 89 .d_flags = D_TTY, 90 .d_kqfilter = cnkqfilter, 91}; 92 93struct cn_device { 94 STAILQ_ENTRY(cn_device) cnd_next; 95 struct vnode *cnd_vp; 96 struct consdev *cnd_cn; 97}; 98 99#define CNDEVPATHMAX 32 100#define CNDEVTAB_SIZE 4 101static struct cn_device cn_devtab[CNDEVTAB_SIZE]; 102static STAILQ_HEAD(, cn_device) cn_devlist = 103 STAILQ_HEAD_INITIALIZER(cn_devlist); 104 105#define CND_INVALID(cnd, td) \ 106 (cnd == NULL || cnd->cnd_vp == NULL || \ 107 (cnd->cnd_vp->v_type == VBAD && !cn_devopen(cnd, td, 1))) 108 109static udev_t cn_udev_t; 110SYSCTL_OPAQUE(_machdep, CPU_CONSDEV, consdev, CTLFLAG_RD, 111 &cn_udev_t, sizeof cn_udev_t, "T,dev_t", ""); 112 113int cons_avail_mask = 0; /* Bit mask. Each registered low level console 114 * which is currently unavailable for inpit 115 * (i.e., if it is in graphics mode) will have 116 * this bit cleared. 117 */ 118static int cn_mute; 119static int openflag; /* how /dev/console was opened */ 120static int cn_is_open; 121static char *consbuf; /* buffer used by `consmsgbuf' */ 122static struct callout conscallout; /* callout for outputting to constty */ 123struct msgbuf consmsgbuf; /* message buffer for console tty */ 124static u_char console_pausing; /* pause after each line during probe */ 125static char *console_pausestr= 126"<pause; press any key to proceed to next line or '.' to end pause mode>"; 127struct tty *constty; /* pointer to console "window" tty */ 128 129void cndebug(char *); 130static void constty_timeout(void *arg); 131 132CONS_DRIVER(cons, NULL, NULL, NULL, NULL, NULL, NULL, NULL); 133SET_DECLARE(cons_set, struct consdev); 134 135void 136cninit(void) 137{ 138 struct consdev *best_cn, *cn, **list; 139 140 /* 141 * Check if we should mute the console (for security reasons perhaps) 142 * It can be changes dynamically using sysctl kern.consmute 143 * once we are up and going. 144 * 145 */ 146 cn_mute = ((boothowto & (RB_MUTE 147 |RB_SINGLE 148 |RB_VERBOSE 149 |RB_ASKNAME 150 |RB_CONFIG)) == RB_MUTE); 151 152 /* 153 * Find the first console with the highest priority. 154 */ 155 best_cn = NULL; 156 SET_FOREACH(list, cons_set) { 157 cn = *list; 158 cnremove(cn); 159 if (cn->cn_probe == NULL) 160 continue; 161 cn->cn_probe(cn); 162 if (cn->cn_pri == CN_DEAD) 163 continue; 164 if (best_cn == NULL || cn->cn_pri > best_cn->cn_pri) 165 best_cn = cn; 166 if (boothowto & RB_MULTIPLE) { 167 /* 168 * Initialize console, and attach to it. 169 */ 170 cnadd(cn); 171 cn->cn_init(cn); 172 } 173 } 174 if (best_cn == NULL) 175 return; 176 if ((boothowto & RB_MULTIPLE) == 0) { 177 cnadd(best_cn); 178 best_cn->cn_init(best_cn); 179 } 180 if (boothowto & RB_PAUSE) 181 console_pausing = 1; 182 /* 183 * Make the best console the preferred console. 184 */ 185 cnselect(best_cn); 186} 187 188void 189cninit_finish() 190{ 191 console_pausing = 0; 192} 193 194/* add a new physical console to back the virtual console */ 195int 196cnadd(struct consdev *cn) 197{ 198 struct cn_device *cnd; 199 int i; 200 201 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) 202 if (cnd->cnd_cn == cn) 203 return (0); 204 for (i = 0; i < CNDEVTAB_SIZE; i++) { 205 cnd = &cn_devtab[i]; 206 if (cnd->cnd_cn == NULL) 207 break; 208 } 209 if (cnd->cnd_cn != NULL) 210 return (ENOMEM); 211 cnd->cnd_cn = cn; 212 if (cn->cn_name[0] == '\0') { 213 /* XXX: it is unclear if/where this print might output */ 214 printf("WARNING: console at %p has no name\n", cn); 215 } 216 STAILQ_INSERT_TAIL(&cn_devlist, cnd, cnd_next); 217 218 /* Add device to the active mask. */ 219 cnavailable(cn, (cn->cn_flags & CN_FLAG_NOAVAIL) == 0); 220 221 return (0); 222} 223 224void 225cnremove(struct consdev *cn) 226{ 227 struct cn_device *cnd; 228 int i; 229 230 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) { 231 if (cnd->cnd_cn != cn) 232 continue; 233 STAILQ_REMOVE(&cn_devlist, cnd, cn_device, cnd_next); 234 if (cnd->cnd_vp != NULL) 235 vn_close(cnd->cnd_vp, openflag, NOCRED, NULL); 236 cnd->cnd_vp = NULL; 237 cnd->cnd_cn = NULL; 238 239 /* Remove this device from available mask. */ 240 for (i = 0; i < CNDEVTAB_SIZE; i++) 241 if (cnd == &cn_devtab[i]) { 242 cons_avail_mask &= ~(1 << i); 243 break; 244 } 245#if 0 246 /* 247 * XXX 248 * syscons gets really confused if console resources are 249 * freed after the system has initialized. 250 */ 251 if (cn->cn_term != NULL) 252 cn->cn_term(cn); 253#endif 254 return; 255 } 256} 257 258void 259cnselect(struct consdev *cn) 260{ 261 struct cn_device *cnd; 262 263 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) { 264 if (cnd->cnd_cn != cn) 265 continue; 266 if (cnd == STAILQ_FIRST(&cn_devlist)) 267 return; 268 STAILQ_REMOVE(&cn_devlist, cnd, cn_device, cnd_next); 269 STAILQ_INSERT_HEAD(&cn_devlist, cnd, cnd_next); 270 return; 271 } 272} 273 274void 275cnavailable(struct consdev *cn, int available) 276{ 277 int i; 278 279 for (i = 0; i < CNDEVTAB_SIZE; i++) { 280 if (cn_devtab[i].cnd_cn == cn) 281 break; 282 } 283 if (available) { 284 if (i < CNDEVTAB_SIZE) 285 cons_avail_mask |= (1 << i); 286 cn->cn_flags &= ~CN_FLAG_NOAVAIL; 287 } else { 288 if (i < CNDEVTAB_SIZE) 289 cons_avail_mask &= ~(1 << i); 290 cn->cn_flags |= CN_FLAG_NOAVAIL; 291 } 292} 293 294int 295cn_unavailable(void) 296{ 297 return (cons_avail_mask == 0); 298} 299 300void 301cndebug(char *str) 302{ 303 int i, len; 304 305 len = strlen(str); 306 cnputc('>'); cnputc('>'); cnputc('>'); cnputc(' '); 307 for (i = 0; i < len; i++) 308 cnputc(str[i]); 309 cnputc('\n'); 310} 311 312/* 313 * XXX: rewrite to use sbufs instead 314 */ 315 316static int 317sysctl_kern_console(SYSCTL_HANDLER_ARGS) 318{ 319 struct cn_device *cnd; 320 struct consdev *cp, **list; 321 char *name, *p; 322 int delete, len, error; 323 324 len = 2; 325 SET_FOREACH(list, cons_set) { 326 cp = *list; 327 if (cp->cn_name[0] != '\0') 328 len += strlen(cp->cn_name) + 1; 329 } 330 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) 331 len += strlen(cnd->cnd_cn->cn_name) + 1; 332 len = len > CNDEVPATHMAX ? len : CNDEVPATHMAX; 333 MALLOC(name, char *, len, M_TEMP, M_WAITOK | M_ZERO); 334 p = name; 335 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) 336 p += sprintf(p, "%s,", cnd->cnd_cn->cn_name); 337 *p++ = '/'; 338 SET_FOREACH(list, cons_set) { 339 cp = *list; 340 if (cp->cn_name[0] != '\0') 341 p += sprintf(p, "%s,", cp->cn_name); 342 } 343 error = sysctl_handle_string(oidp, name, len, req); 344 if (error == 0 && req->newptr != NULL) { 345 p = name; 346 error = ENXIO; 347 delete = 0; 348 if (*p == '-') { 349 delete = 1; 350 p++; 351 } 352 SET_FOREACH(list, cons_set) { 353 cp = *list; 354 if (strcmp(p, cp->cn_name) != 0) 355 continue; 356 if (delete) { 357 cnremove(cp); 358 error = 0; 359 } else { 360 error = cnadd(cp); 361 if (error == 0) 362 cnselect(cp); 363 } 364 break; 365 } 366 } 367 FREE(name, M_TEMP); 368 return (error); 369} 370 371SYSCTL_PROC(_kern, OID_AUTO, console, CTLTYPE_STRING|CTLFLAG_RW, 372 0, 0, sysctl_kern_console, "A", "Console device control"); 373 374/* 375 * User has changed the state of the console muting. 376 * This may require us to open or close the device in question. 377 */ 378static int 379sysctl_kern_consmute(SYSCTL_HANDLER_ARGS) 380{ 381 int error; 382 int ocn_mute; 383 384 ocn_mute = cn_mute; 385 error = sysctl_handle_int(oidp, &cn_mute, 0, req); 386 if (error != 0 || req->newptr == NULL) 387 return (error); 388 if (ocn_mute && !cn_mute && cn_is_open) 389 error = cnopen(NODEV, openflag, 0, curthread); 390 else if (!ocn_mute && cn_mute && cn_is_open) { 391 error = cnclose(NODEV, openflag, 0, curthread); 392 cn_is_open = 1; /* XXX hack */ 393 } 394 return (error); 395} 396 397SYSCTL_PROC(_kern, OID_AUTO, consmute, CTLTYPE_INT|CTLFLAG_RW, 398 0, sizeof(cn_mute), sysctl_kern_consmute, "I", ""); 399 400static int 401cn_devopen(struct cn_device *cnd, struct thread *td, int forceopen) 402{ 403 char path[CNDEVPATHMAX]; 404 struct nameidata nd; 405 struct vnode *vp; 406 dev_t dev; 407 int error; 408 409 if ((vp = cnd->cnd_vp) != NULL) { 410 if (!forceopen && vp->v_type != VBAD) { 411 dev = vp->v_rdev; 412 return ((*devsw(dev)->d_open)(dev, openflag, 0, td)); 413 } 414 cnd->cnd_vp = NULL; 415 vn_close(vp, openflag, td->td_ucred, td); 416 } 417 snprintf(path, sizeof(path), "/dev/%s", cnd->cnd_cn->cn_name); 418 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, path, td); 419 error = vn_open(&nd, &openflag, 0, -1); 420 if (error == 0) { 421 NDFREE(&nd, NDF_ONLY_PNBUF); 422 VOP_UNLOCK(nd.ni_vp, 0, td); 423 if (nd.ni_vp->v_type == VCHR) 424 cnd->cnd_vp = nd.ni_vp; 425 else 426 vn_close(nd.ni_vp, openflag, td->td_ucred, td); 427 } 428 return (cnd->cnd_vp != NULL); 429} 430 431static int 432cnopen(dev_t dev, int flag, int mode, struct thread *td) 433{ 434 struct cn_device *cnd; 435 436 openflag = flag | FWRITE; /* XXX */ 437 cn_is_open = 1; /* console is logically open */ 438 if (cn_mute) 439 return (0); 440 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) 441 cn_devopen(cnd, td, 0); 442 return (0); 443} 444 445static int 446cnclose(dev_t dev, int flag, int mode, struct thread *td) 447{ 448 struct cn_device *cnd; 449 struct vnode *vp; 450 451 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) { 452 if ((vp = cnd->cnd_vp) == NULL) 453 continue; 454 cnd->cnd_vp = NULL; 455 vn_close(vp, openflag, td->td_ucred, td); 456 } 457 cn_is_open = 0; 458 return (0); 459} 460 461static int 462cnread(dev_t dev, struct uio *uio, int flag) 463{ 464 struct cn_device *cnd; 465 466 cnd = STAILQ_FIRST(&cn_devlist); 467 if (cn_mute || CND_INVALID(cnd, curthread)) 468 return (0); 469 dev = cnd->cnd_vp->v_rdev; 470 return ((*devsw(dev)->d_read)(dev, uio, flag)); 471} 472 473static int 474cnwrite(dev_t dev, struct uio *uio, int flag) 475{ 476 struct cn_device *cnd; 477 478 cnd = STAILQ_FIRST(&cn_devlist); 479 if (cn_mute || CND_INVALID(cnd, curthread)) 480 goto done; 481 if (constty) 482 dev = constty->t_dev; 483 else 484 dev = cnd->cnd_vp->v_rdev; 485 if (dev != NULL) { 486 log_console(uio); 487 return ((*devsw(dev)->d_write)(dev, uio, flag)); 488 } 489done: 490 uio->uio_resid = 0; /* dump the data */ 491 return (0); 492} 493 494static int 495cnioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td) 496{ 497 struct cn_device *cnd; 498 int error; 499 500 cnd = STAILQ_FIRST(&cn_devlist); 501 if (cn_mute || CND_INVALID(cnd, td)) 502 return (0); 503 /* 504 * Superuser can always use this to wrest control of console 505 * output from the "virtual" console. 506 */ 507 if (cmd == TIOCCONS && constty) { 508 error = suser(td); 509 if (error) 510 return (error); 511 constty = NULL; 512 return (0); 513 } 514 dev = cnd->cnd_vp->v_rdev; 515 if (dev != NULL) 516 return ((*devsw(dev)->d_ioctl)(dev, cmd, data, flag, td)); 517 return (0); 518} 519 520/* 521 * XXX 522 * poll/kqfilter do not appear to be correct 523 */ 524static int 525cnpoll(dev_t dev, int events, struct thread *td) 526{ 527 struct cn_device *cnd; 528 529 cnd = STAILQ_FIRST(&cn_devlist); 530 if (cn_mute || CND_INVALID(cnd, td)) 531 return (0); 532 dev = cnd->cnd_vp->v_rdev; 533 if (dev != NULL) 534 return ((*devsw(dev)->d_poll)(dev, events, td)); 535 return (0); 536} 537 538static int 539cnkqfilter(dev_t dev, struct knote *kn) 540{ 541 struct cn_device *cnd; 542 543 cnd = STAILQ_FIRST(&cn_devlist); 544 if (cn_mute || CND_INVALID(cnd, curthread)) 545 return (1); 546 dev = cnd->cnd_vp->v_rdev; 547 if (dev != NULL) 548 return ((*devsw(dev)->d_kqfilter)(dev, kn)); 549 return (1); 550} 551 552/* 553 * Low level console routines. 554 */ 555int 556cngetc(void) 557{ 558 int c; 559 560 if (cn_mute) 561 return (-1); 562 while ((c = cncheckc()) == -1) 563 ; 564 if (c == '\r') 565 c = '\n'; /* console input is always ICRNL */ 566 return (c); 567} 568 569int 570cncheckc(void) 571{ 572 struct cn_device *cnd; 573 struct consdev *cn; 574 int c; 575 576 if (cn_mute) 577 return (-1); 578 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) { 579 cn = cnd->cnd_cn; 580#ifdef DDB 581 if (!db_active || !(cn->cn_flags & CN_FLAG_NODEBUG)) { 582#endif 583 c = cn->cn_checkc(cn); 584 if (c != -1) { 585 return (c); 586 } 587#ifdef DDB 588 } 589#endif 590 } 591 return (-1); 592} 593 594void 595cnputc(int c) 596{ 597 struct cn_device *cnd; 598 struct consdev *cn; 599 char *cp; 600 601 if (cn_mute || c == '\0') 602 return; 603 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) { 604 cn = cnd->cnd_cn; 605#ifdef DDB 606 if (!db_active || !(cn->cn_flags & CN_FLAG_NODEBUG)) { 607#endif 608 if (c == '\n') 609 cn->cn_putc(cn, '\r'); 610 cn->cn_putc(cn, c); 611#ifdef DDB 612 } 613#endif 614 } 615#ifdef DDB 616 if (console_pausing && !db_active && (c == '\n')) { 617#else 618 if (console_pausing && (c == '\n')) { 619#endif 620 for (cp = console_pausestr; *cp != '\0'; cp++) 621 cnputc(*cp); 622 if (cngetc() == '.') 623 console_pausing = 0; 624 cnputc('\r'); 625 for (cp = console_pausestr; *cp != '\0'; cp++) 626 cnputc(' '); 627 cnputc('\r'); 628 } 629} 630 631void 632cndbctl(int on) 633{ 634 struct cn_device *cnd; 635 struct consdev *cn; 636 static int refcount; 637 638 if (!on) 639 refcount--; 640 if (refcount == 0) 641 STAILQ_FOREACH(cnd, &cn_devlist, cnd_next) { 642 cn = cnd->cnd_cn; 643 if (cn->cn_dbctl != NULL) 644 cn->cn_dbctl(cn, on); 645 } 646 if (on) 647 refcount++; 648} 649 650static int consmsgbuf_size = 8192; 651SYSCTL_INT(_kern, OID_AUTO, consmsgbuf_size, CTLFLAG_RW, &consmsgbuf_size, 0, 652 ""); 653 654/* 655 * Redirect console output to a tty. 656 */ 657void 658constty_set(struct tty *tp) 659{ 660 int size; 661 662 KASSERT(tp != NULL, ("constty_set: NULL tp")); 663 if (consbuf == NULL) { 664 size = consmsgbuf_size; 665 consbuf = malloc(size, M_TTYS, M_WAITOK); 666 msgbuf_init(&consmsgbuf, consbuf, size); 667 callout_init(&conscallout, 0); 668 } 669 constty = tp; 670 constty_timeout(NULL); 671} 672 673/* 674 * Disable console redirection to a tty. 675 */ 676void 677constty_clear(void) 678{ 679 int c; 680 681 constty = NULL; 682 if (consbuf == NULL) 683 return; 684 callout_stop(&conscallout); 685 while ((c = msgbuf_getchar(&consmsgbuf)) != -1) 686 cnputc(c); 687 free(consbuf, M_TTYS); 688 consbuf = NULL; 689} 690 691/* Times per second to check for pending console tty messages. */ 692static int constty_wakeups_per_second = 5; 693SYSCTL_INT(_kern, OID_AUTO, constty_wakeups_per_second, CTLFLAG_RW, 694 &constty_wakeups_per_second, 0, ""); 695 696static void 697constty_timeout(void *arg) 698{ 699 int c; 700 701 while (constty != NULL && (c = msgbuf_getchar(&consmsgbuf)) != -1) { 702 if (tputchar(c, constty) < 0) 703 constty = NULL; 704 } 705 if (constty != NULL) { 706 callout_reset(&conscallout, hz / constty_wakeups_per_second, 707 constty_timeout, NULL); 708 } else { 709 /* Deallocate the constty buffer memory. */ 710 constty_clear(); 711 } 712} 713 714static void 715cn_drvinit(void *unused) 716{ 717 718 make_dev(&cn_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "console"); 719} 720 721SYSINIT(cndev, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, cn_drvinit, NULL) 722