1 /*- 2 * Copyright (c) 1986, 1988, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 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 * @(#)subr_prf.c 8.3 (Berkeley) 1/21/94 39 * $FreeBSD$ 40 */ 41 42 #include "opt_ddb.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/lock.h> 47 #include <sys/mutex.h> 48 #include <sys/sx.h> 49 #include <sys/kernel.h> 50 #include <sys/msgbuf.h> 51 #include <sys/malloc.h> 52 #include <sys/proc.h> 53 #include <sys/stddef.h> 54 #include <sys/stdint.h> 55 #include <sys/sysctl.h> 56 #include <sys/tty.h> 57 #include <sys/syslog.h> 58 #include <sys/cons.h> 59 #include <sys/uio.h> 60 61 #ifdef DDB 62 #include <ddb/ddb.h> 63 #endif 64 65 /* 66 * Note that stdarg.h and the ANSI style va_start macro is used for both 67 * ANSI and traditional C compilers. 68 */ 69 #include <machine/stdarg.h> 70 71 #define TOCONS 0x01 72 #define TOTTY 0x02 73 #define TOLOG 0x04 74 75 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */ 76 #define MAXNBUF (sizeof(intmax_t) * NBBY + 1) 77 78 struct putchar_arg { 79 int flags; 80 int pri; 81 struct tty *tty; 82 }; 83 84 struct snprintf_arg { 85 char *str; 86 size_t remain; 87 }; 88 89 extern int log_open; 90 91 struct tty *constty; /* pointer to console "window" tty */ 92 93 static void (*v_putc)(int) = cnputc; /* routine to putc on virtual console */ 94 static void msglogchar(int c, int pri); 95 static void msgaddchar(int c, void *dummy); 96 static void putchar(int ch, void *arg); 97 static char *ksprintn(char *nbuf, uintmax_t num, int base, int *len); 98 static void snprintf_func(int ch, void *arg); 99 100 static int consintr = 1; /* Ok to handle console interrupts? */ 101 static int msgbufmapped; /* Set when safe to use msgbuf */ 102 int msgbuftrigger; 103 104 static int log_console_output = 1; 105 TUNABLE_INT("kern.log_console_output", &log_console_output); 106 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW, 107 &log_console_output, 0, ""); 108 109 /* 110 * Warn that a system table is full. 111 */ 112 void 113 tablefull(const char *tab) 114 { 115 116 log(LOG_ERR, "%s: table is full\n", tab); 117 } 118 119 /* 120 * Uprintf prints to the controlling terminal for the current process. 121 * It may block if the tty queue is overfull. No message is printed if 122 * the queue does not clear in a reasonable time. 123 */ 124 int 125 uprintf(const char *fmt, ...) 126 { 127 struct thread *td = curthread; 128 struct proc *p = td->td_proc; 129 va_list ap; 130 struct putchar_arg pca; 131 int retval; 132 133 if (td == NULL || td == PCPU_GET(idlethread)) 134 return (0); 135 136 p = td->td_proc; 137 PROC_LOCK(p); 138 if ((p->p_flag & P_CONTROLT) == 0) { 139 PROC_UNLOCK(p); 140 return (0); 141 } 142 SESS_LOCK(p->p_session); 143 pca.tty = p->p_session->s_ttyp; 144 SESS_UNLOCK(p->p_session); 145 PROC_UNLOCK(p); 146 if (pca.tty == NULL) 147 return (0); 148 pca.flags = TOTTY; 149 va_start(ap, fmt); 150 retval = kvprintf(fmt, putchar, &pca, 10, ap); 151 va_end(ap); 152 153 return (retval); 154 } 155 156 /* 157 * tprintf prints on the controlling terminal associated 158 * with the given session, possibly to the log as well. 159 */ 160 void 161 tprintf(struct proc *p, int pri, const char *fmt, ...) 162 { 163 struct tty *tp = NULL; 164 int flags = 0, shld = 0; 165 va_list ap; 166 struct putchar_arg pca; 167 int retval; 168 169 if (pri != -1) 170 flags |= TOLOG; 171 if (p != NULL) { 172 PROC_LOCK(p); 173 if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) { 174 SESS_LOCK(p->p_session); 175 SESSHOLD(p->p_session); 176 tp = p->p_session->s_ttyp; 177 SESS_UNLOCK(p->p_session); 178 PROC_UNLOCK(p); 179 shld++; 180 if (ttycheckoutq(tp, 0)) 181 flags |= TOTTY; 182 else 183 tp = NULL; 184 } else 185 PROC_UNLOCK(p); 186 } 187 pca.pri = pri; 188 pca.tty = tp; 189 pca.flags = flags; 190 va_start(ap, fmt); 191 retval = kvprintf(fmt, putchar, &pca, 10, ap); 192 va_end(ap); 193 if (shld) { 194 PROC_LOCK(p); 195 SESS_LOCK(p->p_session); 196 SESSRELE(p->p_session); 197 SESS_UNLOCK(p->p_session); 198 PROC_UNLOCK(p); 199 } 200 msgbuftrigger = 1; 201 } 202 203 /* 204 * Ttyprintf displays a message on a tty; it should be used only by 205 * the tty driver, or anything that knows the underlying tty will not 206 * be revoke(2)'d away. Other callers should use tprintf. 207 */ 208 int 209 ttyprintf(struct tty *tp, const char *fmt, ...) 210 { 211 va_list ap; 212 struct putchar_arg pca; 213 int retval; 214 215 va_start(ap, fmt); 216 pca.tty = tp; 217 pca.flags = TOTTY; 218 retval = kvprintf(fmt, putchar, &pca, 10, ap); 219 va_end(ap); 220 return (retval); 221 } 222 223 /* 224 * Log writes to the log buffer, and guarantees not to sleep (so can be 225 * called by interrupt routines). If there is no process reading the 226 * log yet, it writes to the console also. 227 */ 228 void 229 log(int level, const char *fmt, ...) 230 { 231 va_list ap; 232 int retval; 233 struct putchar_arg pca; 234 235 pca.tty = NULL; 236 pca.pri = level; 237 pca.flags = log_open ? TOLOG : TOCONS; 238 239 va_start(ap, fmt); 240 retval = kvprintf(fmt, putchar, &pca, 10, ap); 241 va_end(ap); 242 243 msgbuftrigger = 1; 244 } 245 246 #define CONSCHUNK 128 247 248 void 249 log_console(struct uio *uio) 250 { 251 int c, i, error, iovlen, nl; 252 struct uio muio; 253 struct iovec *miov = NULL; 254 char *consbuffer; 255 int pri; 256 257 if (!log_console_output) 258 return; 259 260 pri = LOG_INFO | LOG_CONSOLE; 261 muio = *uio; 262 iovlen = uio->uio_iovcnt * sizeof (struct iovec); 263 MALLOC(miov, struct iovec *, iovlen, M_TEMP, 0); 264 MALLOC(consbuffer, char *, CONSCHUNK, M_TEMP, 0); 265 bcopy(muio.uio_iov, miov, iovlen); 266 muio.uio_iov = miov; 267 uio = &muio; 268 269 nl = 0; 270 while (uio->uio_resid > 0) { 271 c = imin(uio->uio_resid, CONSCHUNK); 272 error = uiomove(consbuffer, c, uio); 273 if (error != 0) 274 break; 275 for (i = 0; i < c; i++) { 276 msglogchar(consbuffer[i], pri); 277 if (consbuffer[i] == '\n') 278 nl = 1; 279 else 280 nl = 0; 281 } 282 } 283 if (!nl) 284 msglogchar('\n', pri); 285 msgbuftrigger = 1; 286 FREE(miov, M_TEMP); 287 FREE(consbuffer, M_TEMP); 288 return; 289 } 290 291 int 292 printf(const char *fmt, ...) 293 { 294 va_list ap; 295 int savintr; 296 struct putchar_arg pca; 297 int retval; 298 299 savintr = consintr; /* disable interrupts */ 300 consintr = 0; 301 va_start(ap, fmt); 302 pca.tty = NULL; 303 pca.flags = TOCONS | TOLOG; 304 pca.pri = -1; 305 retval = kvprintf(fmt, putchar, &pca, 10, ap); 306 va_end(ap); 307 if (!panicstr) 308 msgbuftrigger = 1; 309 consintr = savintr; /* reenable interrupts */ 310 return (retval); 311 } 312 313 int 314 vprintf(const char *fmt, va_list ap) 315 { 316 int savintr; 317 struct putchar_arg pca; 318 int retval; 319 320 savintr = consintr; /* disable interrupts */ 321 consintr = 0; 322 pca.tty = NULL; 323 pca.flags = TOCONS | TOLOG; 324 pca.pri = -1; 325 retval = kvprintf(fmt, putchar, &pca, 10, ap); 326 if (!panicstr) 327 msgbuftrigger = 1; 328 consintr = savintr; /* reenable interrupts */ 329 return (retval); 330 } 331 332 /* 333 * Print a character on console or users terminal. If destination is 334 * the console then the last bunch of characters are saved in msgbuf for 335 * inspection later. 336 */ 337 static void 338 putchar(int c, void *arg) 339 { 340 struct putchar_arg *ap = (struct putchar_arg*) arg; 341 int flags = ap->flags; 342 struct tty *tp = ap->tty; 343 if (panicstr) 344 constty = NULL; 345 if ((flags & TOCONS) && tp == NULL && constty) { 346 tp = constty; 347 flags |= TOTTY; 348 } 349 if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 && 350 (flags & TOCONS) && tp == constty) 351 constty = NULL; 352 if ((flags & TOLOG)) 353 msglogchar(c, ap->pri); 354 if ((flags & TOCONS) && constty == NULL && c != '\0') 355 (*v_putc)(c); 356 } 357 358 /* 359 * Scaled down version of sprintf(3). 360 */ 361 int 362 sprintf(char *buf, const char *cfmt, ...) 363 { 364 int retval; 365 va_list ap; 366 367 va_start(ap, cfmt); 368 retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap); 369 buf[retval] = '\0'; 370 va_end(ap); 371 return (retval); 372 } 373 374 /* 375 * Scaled down version of vsprintf(3). 376 */ 377 int 378 vsprintf(char *buf, const char *cfmt, va_list ap) 379 { 380 int retval; 381 382 retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap); 383 buf[retval] = '\0'; 384 return (retval); 385 } 386 387 /* 388 * Scaled down version of snprintf(3). 389 */ 390 int 391 snprintf(char *str, size_t size, const char *format, ...) 392 { 393 int retval; 394 va_list ap; 395 396 va_start(ap, format); 397 retval = vsnprintf(str, size, format, ap); 398 va_end(ap); 399 return(retval); 400 } 401 402 /* 403 * Scaled down version of vsnprintf(3). 404 */ 405 int 406 vsnprintf(char *str, size_t size, const char *format, va_list ap) 407 { 408 struct snprintf_arg info; 409 int retval; 410 411 info.str = str; 412 info.remain = size; 413 retval = kvprintf(format, snprintf_func, &info, 10, ap); 414 if (info.remain >= 1) 415 *info.str++ = '\0'; 416 return (retval); 417 } 418 419 static void 420 snprintf_func(int ch, void *arg) 421 { 422 struct snprintf_arg *const info = arg; 423 424 if (info->remain >= 2) { 425 *info->str++ = ch; 426 info->remain--; 427 } 428 } 429 430 /* 431 * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse 432 * order; return an optional length and a pointer to the last character 433 * written in the buffer (i.e., the first character of the string). 434 * The buffer pointed to by `nbuf' must have length >= MAXNBUF. 435 */ 436 static char * 437 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp) 438 { 439 char *p; 440 441 p = nbuf; 442 *p = '\0'; 443 do { 444 *++p = hex2ascii(num % base); 445 } while (num /= base); 446 if (lenp) 447 *lenp = p - nbuf; 448 return (p); 449 } 450 451 /* 452 * Scaled down version of printf(3). 453 * 454 * Two additional formats: 455 * 456 * The format %b is supported to decode error registers. 457 * Its usage is: 458 * 459 * printf("reg=%b\n", regval, "<base><arg>*"); 460 * 461 * where <base> is the output base expressed as a control character, e.g. 462 * \10 gives octal; \20 gives hex. Each arg is a sequence of characters, 463 * the first of which gives the bit number to be inspected (origin 1), and 464 * the next characters (up to a control character, i.e. a character <= 32), 465 * give the name of the register. Thus: 466 * 467 * kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n"); 468 * 469 * would produce output: 470 * 471 * reg=3<BITTWO,BITONE> 472 * 473 * XXX: %D -- Hexdump, takes pointer and separator string: 474 * ("%6D", ptr, ":") -> XX:XX:XX:XX:XX:XX 475 * ("%*D", len, ptr, " " -> XX XX XX XX ... 476 */ 477 int 478 kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap) 479 { 480 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; } 481 char nbuf[MAXNBUF]; 482 char *d; 483 const char *p, *percent, *q; 484 u_char *up; 485 int ch, n; 486 uintmax_t num; 487 int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot; 488 int jflag, tflag, zflag; 489 int dwidth; 490 char padc; 491 int retval = 0; 492 493 num = 0; 494 if (!func) 495 d = (char *) arg; 496 else 497 d = NULL; 498 499 if (fmt == NULL) 500 fmt = "(fmt null)\n"; 501 502 if (radix < 2 || radix > 36) 503 radix = 10; 504 505 for (;;) { 506 padc = ' '; 507 width = 0; 508 while ((ch = (u_char)*fmt++) != '%') { 509 if (ch == '\0') 510 return (retval); 511 PCHAR(ch); 512 } 513 percent = fmt - 1; 514 qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0; 515 sign = 0; dot = 0; dwidth = 0; 516 jflag = 0; tflag = 0; zflag = 0; 517 reswitch: switch (ch = (u_char)*fmt++) { 518 case '.': 519 dot = 1; 520 goto reswitch; 521 case '#': 522 sharpflag = 1; 523 goto reswitch; 524 case '+': 525 sign = 1; 526 goto reswitch; 527 case '-': 528 ladjust = 1; 529 goto reswitch; 530 case '%': 531 PCHAR(ch); 532 break; 533 case '*': 534 if (!dot) { 535 width = va_arg(ap, int); 536 if (width < 0) { 537 ladjust = !ladjust; 538 width = -width; 539 } 540 } else { 541 dwidth = va_arg(ap, int); 542 } 543 goto reswitch; 544 case '0': 545 if (!dot) { 546 padc = '0'; 547 goto reswitch; 548 } 549 case '1': case '2': case '3': case '4': 550 case '5': case '6': case '7': case '8': case '9': 551 for (n = 0;; ++fmt) { 552 n = n * 10 + ch - '0'; 553 ch = *fmt; 554 if (ch < '0' || ch > '9') 555 break; 556 } 557 if (dot) 558 dwidth = n; 559 else 560 width = n; 561 goto reswitch; 562 case 'b': 563 num = (u_int)va_arg(ap, int); 564 p = va_arg(ap, char *); 565 for (q = ksprintn(nbuf, num, *p++, NULL); *q;) 566 PCHAR(*q--); 567 568 if (num == 0) 569 break; 570 571 for (tmp = 0; *p;) { 572 n = *p++; 573 if (num & (1 << (n - 1))) { 574 PCHAR(tmp ? ',' : '<'); 575 for (; (n = *p) > ' '; ++p) 576 PCHAR(n); 577 tmp = 1; 578 } else 579 for (; *p > ' '; ++p) 580 continue; 581 } 582 if (tmp) 583 PCHAR('>'); 584 break; 585 case 'c': 586 PCHAR(va_arg(ap, int)); 587 break; 588 case 'D': 589 up = va_arg(ap, u_char *); 590 p = va_arg(ap, char *); 591 if (!width) 592 width = 16; 593 while(width--) { 594 PCHAR(hex2ascii(*up >> 4)); 595 PCHAR(hex2ascii(*up & 0x0f)); 596 up++; 597 if (width) 598 for (q=p;*q;q++) 599 PCHAR(*q); 600 } 601 break; 602 case 'd': 603 case 'i': 604 base = 10; 605 sign = 1; 606 goto handle_sign; 607 case 'j': 608 jflag = 1; 609 goto reswitch; 610 case 'l': 611 if (lflag) { 612 lflag = 0; 613 qflag = 1; 614 } else 615 lflag = 1; 616 goto reswitch; 617 case 'n': 618 if (jflag) 619 *(va_arg(ap, intmax_t *)) = retval; 620 else if (qflag) 621 *(va_arg(ap, quad_t *)) = retval; 622 else if (lflag) 623 *(va_arg(ap, long *)) = retval; 624 else if (zflag) 625 *(va_arg(ap, size_t *)) = retval; 626 else 627 *(va_arg(ap, int *)) = retval; 628 break; 629 case 'o': 630 base = 8; 631 goto handle_nosign; 632 case 'p': 633 base = 16; 634 sharpflag = (width == 0); 635 sign = 0; 636 num = (uintptr_t)va_arg(ap, void *); 637 goto number; 638 case 'q': 639 qflag = 1; 640 goto reswitch; 641 case 'r': 642 base = radix; 643 if (sign) 644 goto handle_sign; 645 goto handle_nosign; 646 case 's': 647 p = va_arg(ap, char *); 648 if (p == NULL) 649 p = "(null)"; 650 if (!dot) 651 n = strlen (p); 652 else 653 for (n = 0; n < dwidth && p[n]; n++) 654 continue; 655 656 width -= n; 657 658 if (!ladjust && width > 0) 659 while (width--) 660 PCHAR(padc); 661 while (n--) 662 PCHAR(*p++); 663 if (ladjust && width > 0) 664 while (width--) 665 PCHAR(padc); 666 break; 667 case 't': 668 tflag = 1; 669 goto reswitch; 670 break; 671 case 'u': 672 base = 10; 673 goto handle_nosign; 674 case 'x': 675 case 'X': 676 base = 16; 677 goto handle_nosign; 678 case 'y': 679 base = 16; 680 sign = 1; 681 goto handle_sign; 682 case 'z': 683 zflag = 1; 684 goto reswitch; 685 handle_nosign: 686 sign = 0; 687 if (jflag) 688 num = va_arg(ap, uintmax_t); 689 else if (qflag) 690 num = va_arg(ap, u_quad_t); 691 else if (tflag) 692 num = va_arg(ap, ptrdiff_t); 693 else if (lflag) 694 num = va_arg(ap, u_long); 695 else if (zflag) 696 num = va_arg(ap, size_t); 697 else 698 num = va_arg(ap, u_int); 699 goto number; 700 handle_sign: 701 if (jflag) 702 num = va_arg(ap, intmax_t); 703 else if (qflag) 704 num = va_arg(ap, quad_t); 705 else if (tflag) 706 num = va_arg(ap, ptrdiff_t); 707 else if (lflag) 708 num = va_arg(ap, long); 709 else if (zflag) 710 num = va_arg(ap, size_t); 711 else 712 num = va_arg(ap, int); 713 number: 714 if (sign && (intmax_t)num < 0) { 715 neg = 1; 716 num = -(intmax_t)num; 717 } 718 p = ksprintn(nbuf, num, base, &tmp); 719 if (sharpflag && num != 0) { 720 if (base == 8) 721 tmp++; 722 else if (base == 16) 723 tmp += 2; 724 } 725 if (neg) 726 tmp++; 727 728 if (!ladjust && width && (width -= tmp) > 0) 729 while (width--) 730 PCHAR(padc); 731 if (neg) 732 PCHAR('-'); 733 if (sharpflag && num != 0) { 734 if (base == 8) { 735 PCHAR('0'); 736 } else if (base == 16) { 737 PCHAR('0'); 738 PCHAR('x'); 739 } 740 } 741 742 while (*p) 743 PCHAR(*p--); 744 745 if (ladjust && width && (width -= tmp) > 0) 746 while (width--) 747 PCHAR(padc); 748 749 break; 750 default: 751 while (percent < fmt) 752 PCHAR(*percent++); 753 break; 754 } 755 } 756 #undef PCHAR 757 } 758 759 /* 760 * Put character in log buffer with a particular priority. 761 */ 762 static void 763 msglogchar(int c, int pri) 764 { 765 static int lastpri = -1; 766 static int dangling; 767 char nbuf[MAXNBUF]; 768 char *p; 769 770 if (!msgbufmapped) 771 return; 772 if (c == '\0' || c == '\r') 773 return; 774 if (pri != -1 && pri != lastpri) { 775 if (dangling) { 776 msgaddchar('\n', NULL); 777 dangling = 0; 778 } 779 msgaddchar('<', NULL); 780 for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL); *p;) 781 msgaddchar(*p--, NULL); 782 msgaddchar('>', NULL); 783 lastpri = pri; 784 } 785 msgaddchar(c, NULL); 786 if (c == '\n') { 787 dangling = 0; 788 lastpri = -1; 789 } else { 790 dangling = 1; 791 } 792 } 793 794 /* 795 * Put char in log buffer 796 */ 797 static void 798 msgaddchar(int c, void *dummy) 799 { 800 struct msgbuf *mbp; 801 802 if (!msgbufmapped) 803 return; 804 mbp = msgbufp; 805 mbp->msg_ptr[mbp->msg_bufx++] = c; 806 if (mbp->msg_bufx >= mbp->msg_size) 807 mbp->msg_bufx = 0; 808 /* If the buffer is full, keep the most recent data. */ 809 if (mbp->msg_bufr == mbp->msg_bufx) { 810 if (++mbp->msg_bufr >= mbp->msg_size) 811 mbp->msg_bufr = 0; 812 } 813 } 814 815 static void 816 msgbufcopy(struct msgbuf *oldp) 817 { 818 int pos; 819 820 pos = oldp->msg_bufr; 821 while (pos != oldp->msg_bufx) { 822 msglogchar(oldp->msg_ptr[pos], -1); 823 if (++pos >= oldp->msg_size) 824 pos = 0; 825 } 826 } 827 828 void 829 msgbufinit(void *ptr, int size) 830 { 831 char *cp; 832 static struct msgbuf *oldp = NULL; 833 834 size -= sizeof(*msgbufp); 835 cp = (char *)ptr; 836 msgbufp = (struct msgbuf *) (cp + size); 837 if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size || 838 msgbufp->msg_bufx >= size || msgbufp->msg_bufx < 0 || 839 msgbufp->msg_bufr >= size || msgbufp->msg_bufr < 0) { 840 bzero(cp, size); 841 bzero(msgbufp, sizeof(*msgbufp)); 842 msgbufp->msg_magic = MSG_MAGIC; 843 msgbufp->msg_size = (char *)msgbufp - cp; 844 } 845 msgbufp->msg_ptr = cp; 846 if (msgbufmapped && oldp != msgbufp) 847 msgbufcopy(oldp); 848 msgbufmapped = 1; 849 oldp = msgbufp; 850 } 851 852 SYSCTL_DECL(_security_bsd); 853 854 static int unprivileged_read_msgbuf = 1; 855 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_read_msgbuf, 856 CTLFLAG_RW, &unprivileged_read_msgbuf, 0, 857 "Unprivileged processes may read the kernel message buffer"); 858 859 /* Sysctls for accessing/clearing the msgbuf */ 860 static int 861 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS) 862 { 863 int error; 864 865 if (!unprivileged_read_msgbuf) { 866 error = suser(req->td); 867 if (error) 868 return (error); 869 } 870 871 /* 872 * Unwind the buffer, so that it's linear (possibly starting with 873 * some initial nulls). 874 */ 875 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr + msgbufp->msg_bufx, 876 msgbufp->msg_size - msgbufp->msg_bufx, req); 877 if (error) 878 return (error); 879 if (msgbufp->msg_bufx > 0) { 880 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr, 881 msgbufp->msg_bufx, req); 882 } 883 return (error); 884 } 885 886 SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD, 887 0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer"); 888 889 static int msgbuf_clear; 890 891 static int 892 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS) 893 { 894 int error; 895 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); 896 if (!error && req->newptr) { 897 /* Clear the buffer and reset write pointer */ 898 bzero(msgbufp->msg_ptr, msgbufp->msg_size); 899 msgbufp->msg_bufr = msgbufp->msg_bufx = 0; 900 msgbuf_clear = 0; 901 } 902 return (error); 903 } 904 905 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear, 906 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0, 907 sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer"); 908 909 #ifdef DDB 910 911 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf) 912 { 913 int i, j; 914 915 if (!msgbufmapped) { 916 db_printf("msgbuf not mapped yet\n"); 917 return; 918 } 919 db_printf("msgbufp = %p\n", msgbufp); 920 db_printf("magic = %x, size = %d, r= %d, w = %d, ptr = %p\n", 921 msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_bufr, 922 msgbufp->msg_bufx, msgbufp->msg_ptr); 923 for (i = 0; i < msgbufp->msg_size; i++) { 924 j = (i + msgbufp->msg_bufr) % msgbufp->msg_size; 925 db_printf("%c", msgbufp->msg_ptr[j]); 926 } 927 db_printf("\n"); 928 } 929 930 #endif /* DDB */ 931