hexdump.c revision 92069
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: head/sys/kern/subr_prf.c 92069 2002-03-11 07:53:13Z tanimura $ 40 */ 41 42#include <sys/param.h> 43#include <sys/systm.h> 44#include <sys/lock.h> 45#include <sys/mutex.h> 46#include <sys/sx.h> 47#include <sys/kernel.h> 48#include <sys/msgbuf.h> 49#include <sys/malloc.h> 50#include <sys/proc.h> 51#include <sys/sysctl.h> 52#include <sys/tty.h> 53#include <sys/syslog.h> 54#include <sys/cons.h> 55#include <sys/uio.h> 56 57/* 58 * Note that stdarg.h and the ANSI style va_start macro is used for both 59 * ANSI and traditional C compilers. 60 */ 61#include <machine/stdarg.h> 62 63#define TOCONS 0x01 64#define TOTTY 0x02 65#define TOLOG 0x04 66 67/* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */ 68#define MAXNBUF (sizeof(quad_t) * NBBY + 1) 69 70struct putchar_arg { 71 int flags; 72 int pri; 73 struct tty *tty; 74}; 75 76struct snprintf_arg { 77 char *str; 78 size_t remain; 79}; 80 81extern int log_open; 82 83struct tty *constty; /* pointer to console "window" tty */ 84 85static void (*v_putc)(int) = cnputc; /* routine to putc on virtual console */ 86static void msglogchar(int c, int pri); 87static void msgaddchar(int c, void *dummy); 88static void putchar __P((int ch, void *arg)); 89static char *ksprintn __P((char *nbuf, u_long num, int base, int *len)); 90static char *ksprintqn __P((char *nbuf, u_quad_t num, int base, int *len)); 91static void snprintf_func __P((int ch, void *arg)); 92 93static int consintr = 1; /* Ok to handle console interrupts? */ 94static int msgbufmapped; /* Set when safe to use msgbuf */ 95int msgbuftrigger; 96 97/* 98 * Warn that a system table is full. 99 */ 100void 101tablefull(const char *tab) 102{ 103 104 log(LOG_ERR, "%s: table is full\n", tab); 105} 106 107/* 108 * Uprintf prints to the controlling terminal for the current process. 109 * It may block if the tty queue is overfull. No message is printed if 110 * the queue does not clear in a reasonable time. 111 */ 112int 113uprintf(const char *fmt, ...) 114{ 115 struct thread *td = curthread; 116 struct proc *p = td->td_proc; 117 va_list ap; 118 struct putchar_arg pca; 119 int retval; 120 121 if (td == NULL || td == PCPU_GET(idlethread)) 122 return (0); 123 124 p = td->td_proc; 125 PROC_LOCK(p); 126 if ((p->p_flag & P_CONTROLT) == 0) { 127 PROC_UNLOCK(p); 128 return (0); 129 } 130 SESS_LOCK(p->p_session); 131 pca.tty = p->p_session->s_ttyp; 132 SESS_UNLOCK(p->p_session); 133 PROC_UNLOCK(p); 134 if (pca.tty == NULL) 135 return (0); 136 pca.flags = TOTTY; 137 va_start(ap, fmt); 138 retval = kvprintf(fmt, putchar, &pca, 10, ap); 139 va_end(ap); 140 141 return (retval); 142} 143 144/* 145 * tprintf prints on the controlling terminal associated 146 * with the given session, possibly to the log as well. 147 */ 148void 149tprintf(struct proc *p, int pri, const char *fmt, ...) 150{ 151 struct tty *tp = NULL; 152 int flags = 0, shld = 0; 153 va_list ap; 154 struct putchar_arg pca; 155 int retval; 156 157 if (pri != -1) 158 flags |= TOLOG; 159 if (p != NULL) { 160 PROC_LOCK(p); 161 if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) { 162 SESS_LOCK(p->p_session); 163 SESSHOLD(p->p_session); 164 tp = p->p_session->s_ttyp; 165 SESS_UNLOCK(p->p_session); 166 PROC_UNLOCK(p); 167 shld++; 168 if (ttycheckoutq(tp, 0)) 169 flags |= TOTTY; 170 else 171 tp = NULL; 172 } else 173 PROC_UNLOCK(p); 174 } 175 pca.pri = pri; 176 pca.tty = tp; 177 pca.flags = flags; 178 va_start(ap, fmt); 179 retval = kvprintf(fmt, putchar, &pca, 10, ap); 180 va_end(ap); 181 if (shld) { 182 PROC_LOCK(p); 183 SESS_LOCK(p->p_session); 184 SESSRELE(p->p_session); 185 SESS_UNLOCK(p->p_session); 186 PROC_UNLOCK(p); 187 } 188 msgbuftrigger = 1; 189} 190 191/* 192 * Ttyprintf displays a message on a tty; it should be used only by 193 * the tty driver, or anything that knows the underlying tty will not 194 * be revoke(2)'d away. Other callers should use tprintf. 195 */ 196int 197ttyprintf(struct tty *tp, const char *fmt, ...) 198{ 199 va_list ap; 200 struct putchar_arg pca; 201 int retval; 202 203 va_start(ap, fmt); 204 pca.tty = tp; 205 pca.flags = TOTTY; 206 retval = kvprintf(fmt, putchar, &pca, 10, ap); 207 va_end(ap); 208 return (retval); 209} 210 211/* 212 * Log writes to the log buffer, and guarantees not to sleep (so can be 213 * called by interrupt routines). If there is no process reading the 214 * log yet, it writes to the console also. 215 */ 216void 217log(int level, const char *fmt, ...) 218{ 219 va_list ap; 220 int retval; 221 struct putchar_arg pca; 222 223 pca.tty = NULL; 224 pca.pri = level; 225 pca.flags = log_open ? TOLOG : TOCONS; 226 227 va_start(ap, fmt); 228 retval = kvprintf(fmt, putchar, &pca, 10, ap); 229 va_end(ap); 230 231 msgbuftrigger = 1; 232} 233 234#define CONSCHUNK 128 235 236void 237log_console(struct uio *uio) 238{ 239 int c, i, error, iovlen, nl; 240 struct uio muio; 241 struct iovec *miov = NULL; 242 char *consbuffer; 243 int pri; 244 245 pri = LOG_INFO | LOG_CONSOLE; 246 muio = *uio; 247 iovlen = uio->uio_iovcnt * sizeof (struct iovec); 248 MALLOC(miov, struct iovec *, iovlen, M_TEMP, M_WAITOK); 249 MALLOC(consbuffer, char *, CONSCHUNK, M_TEMP, M_WAITOK); 250 bcopy((caddr_t)muio.uio_iov, (caddr_t)miov, iovlen); 251 muio.uio_iov = miov; 252 uio = &muio; 253 254 nl = 0; 255 while (uio->uio_resid > 0) { 256 c = imin(uio->uio_resid, CONSCHUNK); 257 error = uiomove(consbuffer, c, uio); 258 if (error != 0) 259 return; 260 for (i = 0; i < c; i++) { 261 msglogchar(consbuffer[i], pri); 262 if (consbuffer[i] == '\n') 263 nl = 1; 264 else 265 nl = 0; 266 } 267 } 268 if (!nl) 269 msglogchar('\n', pri); 270 msgbuftrigger = 1; 271 FREE(miov, M_TEMP); 272 FREE(consbuffer, M_TEMP); 273 return; 274} 275 276int 277printf(const char *fmt, ...) 278{ 279 va_list ap; 280 int savintr; 281 struct putchar_arg pca; 282 int retval; 283 284 savintr = consintr; /* disable interrupts */ 285 consintr = 0; 286 va_start(ap, fmt); 287 pca.tty = NULL; 288 pca.flags = TOCONS | TOLOG; 289 pca.pri = -1; 290 retval = kvprintf(fmt, putchar, &pca, 10, ap); 291 va_end(ap); 292 if (!panicstr) 293 msgbuftrigger = 1; 294 consintr = savintr; /* reenable interrupts */ 295 return (retval); 296} 297 298int 299vprintf(const char *fmt, va_list ap) 300{ 301 int savintr; 302 struct putchar_arg pca; 303 int retval; 304 305 savintr = consintr; /* disable interrupts */ 306 consintr = 0; 307 pca.tty = NULL; 308 pca.flags = TOCONS | TOLOG; 309 pca.pri = -1; 310 retval = kvprintf(fmt, putchar, &pca, 10, ap); 311 if (!panicstr) 312 msgbuftrigger = 1; 313 consintr = savintr; /* reenable interrupts */ 314 return (retval); 315} 316 317/* 318 * Print a character on console or users terminal. If destination is 319 * the console then the last bunch of characters are saved in msgbuf for 320 * inspection later. 321 */ 322static void 323putchar(int c, void *arg) 324{ 325 struct putchar_arg *ap = (struct putchar_arg*) arg; 326 int flags = ap->flags; 327 struct tty *tp = ap->tty; 328 if (panicstr) 329 constty = NULL; 330 if ((flags & TOCONS) && tp == NULL && constty) { 331 tp = constty; 332 flags |= TOTTY; 333 } 334 if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 && 335 (flags & TOCONS) && tp == constty) 336 constty = NULL; 337 if ((flags & TOLOG)) 338 msglogchar(c, ap->pri); 339 if ((flags & TOCONS) && constty == NULL && c != '\0') 340 (*v_putc)(c); 341} 342 343/* 344 * Scaled down version of sprintf(3). 345 */ 346int 347sprintf(char *buf, const char *cfmt, ...) 348{ 349 int retval; 350 va_list ap; 351 352 va_start(ap, cfmt); 353 retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap); 354 buf[retval] = '\0'; 355 va_end(ap); 356 return (retval); 357} 358 359/* 360 * Scaled down version of vsprintf(3). 361 */ 362int 363vsprintf(char *buf, const char *cfmt, va_list ap) 364{ 365 int retval; 366 367 retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap); 368 buf[retval] = '\0'; 369 return (retval); 370} 371 372/* 373 * Scaled down version of snprintf(3). 374 */ 375int 376snprintf(char *str, size_t size, const char *format, ...) 377{ 378 int retval; 379 va_list ap; 380 381 va_start(ap, format); 382 retval = vsnprintf(str, size, format, ap); 383 va_end(ap); 384 return(retval); 385} 386 387/* 388 * Scaled down version of vsnprintf(3). 389 */ 390int 391vsnprintf(char *str, size_t size, const char *format, va_list ap) 392{ 393 struct snprintf_arg info; 394 int retval; 395 396 info.str = str; 397 info.remain = size; 398 retval = kvprintf(format, snprintf_func, &info, 10, ap); 399 if (info.remain >= 1) 400 *info.str++ = '\0'; 401 return (retval); 402} 403 404static void 405snprintf_func(int ch, void *arg) 406{ 407 struct snprintf_arg *const info = arg; 408 409 if (info->remain >= 2) { 410 *info->str++ = ch; 411 info->remain--; 412 } 413} 414 415/* 416 * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse 417 * order; return an optional length and a pointer to the last character 418 * written in the buffer (i.e., the first character of the string). 419 * The buffer pointed to by `nbuf' must have length >= MAXNBUF. 420 */ 421static char * 422ksprintn(nbuf, ul, base, lenp) 423 char *nbuf; 424 u_long ul; 425 int base, *lenp; 426{ 427 char *p; 428 429 p = nbuf; 430 *p = '\0'; 431 do { 432 *++p = hex2ascii(ul % base); 433 } while (ul /= base); 434 if (lenp) 435 *lenp = p - nbuf; 436 return (p); 437} 438/* ksprintn, but for a quad_t. */ 439static char * 440ksprintqn(nbuf, uq, base, lenp) 441 char *nbuf; 442 u_quad_t uq; 443 int base, *lenp; 444{ 445 char *p; 446 447 p = nbuf; 448 *p = '\0'; 449 do { 450 *++p = hex2ascii(uq % base); 451 } while (uq /= base); 452 if (lenp) 453 *lenp = p - nbuf; 454 return (p); 455} 456 457/* 458 * Scaled down version of printf(3). 459 * 460 * Two additional formats: 461 * 462 * The format %b is supported to decode error registers. 463 * Its usage is: 464 * 465 * printf("reg=%b\n", regval, "<base><arg>*"); 466 * 467 * where <base> is the output base expressed as a control character, e.g. 468 * \10 gives octal; \20 gives hex. Each arg is a sequence of characters, 469 * the first of which gives the bit number to be inspected (origin 1), and 470 * the next characters (up to a control character, i.e. a character <= 32), 471 * give the name of the register. Thus: 472 * 473 * kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n"); 474 * 475 * would produce output: 476 * 477 * reg=3<BITTWO,BITONE> 478 * 479 * XXX: %D -- Hexdump, takes pointer and separator string: 480 * ("%6D", ptr, ":") -> XX:XX:XX:XX:XX:XX 481 * ("%*D", len, ptr, " " -> XX XX XX XX ... 482 */ 483int 484kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap) 485{ 486#define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; } 487 char nbuf[MAXNBUF]; 488 char *p, *q, *d; 489 u_char *up; 490 int ch, n; 491 u_long ul; 492 u_quad_t uq; 493 int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot; 494 int dwidth; 495 char padc; 496 int retval = 0; 497 498 ul = 0; 499 uq = 0; 500 if (!func) 501 d = (char *) arg; 502 else 503 d = NULL; 504 505 if (fmt == NULL) 506 fmt = "(fmt null)\n"; 507 508 if (radix < 2 || radix > 36) 509 radix = 10; 510 511 for (;;) { 512 padc = ' '; 513 width = 0; 514 while ((ch = (u_char)*fmt++) != '%') { 515 if (ch == '\0') 516 return (retval); 517 PCHAR(ch); 518 } 519 qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0; 520 sign = 0; dot = 0; dwidth = 0; 521reswitch: switch (ch = (u_char)*fmt++) { 522 case '.': 523 dot = 1; 524 goto reswitch; 525 case '#': 526 sharpflag = 1; 527 goto reswitch; 528 case '+': 529 sign = 1; 530 goto reswitch; 531 case '-': 532 ladjust = 1; 533 goto reswitch; 534 case '%': 535 PCHAR(ch); 536 break; 537 case '*': 538 if (!dot) { 539 width = va_arg(ap, int); 540 if (width < 0) { 541 ladjust = !ladjust; 542 width = -width; 543 } 544 } else { 545 dwidth = va_arg(ap, int); 546 } 547 goto reswitch; 548 case '0': 549 if (!dot) { 550 padc = '0'; 551 goto reswitch; 552 } 553 case '1': case '2': case '3': case '4': 554 case '5': case '6': case '7': case '8': case '9': 555 for (n = 0;; ++fmt) { 556 n = n * 10 + ch - '0'; 557 ch = *fmt; 558 if (ch < '0' || ch > '9') 559 break; 560 } 561 if (dot) 562 dwidth = n; 563 else 564 width = n; 565 goto reswitch; 566 case 'b': 567 ul = va_arg(ap, int); 568 p = va_arg(ap, char *); 569 for (q = ksprintn(nbuf, ul, *p++, NULL); *q;) 570 PCHAR(*q--); 571 572 if (!ul) 573 break; 574 575 for (tmp = 0; *p;) { 576 n = *p++; 577 if (ul & (1 << (n - 1))) { 578 PCHAR(tmp ? ',' : '<'); 579 for (; (n = *p) > ' '; ++p) 580 PCHAR(n); 581 tmp = 1; 582 } else 583 for (; *p > ' '; ++p) 584 continue; 585 } 586 if (tmp) 587 PCHAR('>'); 588 break; 589 case 'c': 590 PCHAR(va_arg(ap, int)); 591 break; 592 case 'D': 593 up = va_arg(ap, u_char *); 594 p = va_arg(ap, char *); 595 if (!width) 596 width = 16; 597 while(width--) { 598 PCHAR(hex2ascii(*up >> 4)); 599 PCHAR(hex2ascii(*up & 0x0f)); 600 up++; 601 if (width) 602 for (q=p;*q;q++) 603 PCHAR(*q); 604 } 605 break; 606 case 'd': 607 if (qflag) 608 uq = va_arg(ap, quad_t); 609 else if (lflag) 610 ul = va_arg(ap, long); 611 else 612 ul = va_arg(ap, int); 613 sign = 1; 614 base = 10; 615 goto number; 616 case 'l': 617 if (lflag) { 618 lflag = 0; 619 qflag = 1; 620 } else 621 lflag = 1; 622 goto reswitch; 623 case 'o': 624 if (qflag) 625 uq = va_arg(ap, u_quad_t); 626 else if (lflag) 627 ul = va_arg(ap, u_long); 628 else 629 ul = va_arg(ap, u_int); 630 base = 8; 631 goto nosign; 632 case 'p': 633 ul = (uintptr_t)va_arg(ap, void *); 634 base = 16; 635 sharpflag = (width == 0); 636 goto nosign; 637 case 'q': 638 qflag = 1; 639 goto reswitch; 640 case 'n': 641 case 'r': 642 if (qflag) 643 uq = va_arg(ap, u_quad_t); 644 else if (lflag) 645 ul = va_arg(ap, u_long); 646 else 647 ul = sign ? 648 (u_long)va_arg(ap, int) : va_arg(ap, u_int); 649 base = radix; 650 goto number; 651 case 's': 652 p = va_arg(ap, char *); 653 if (p == NULL) 654 p = "(null)"; 655 if (!dot) 656 n = strlen (p); 657 else 658 for (n = 0; n < dwidth && p[n]; n++) 659 continue; 660 661 width -= n; 662 663 if (!ladjust && width > 0) 664 while (width--) 665 PCHAR(padc); 666 while (n--) 667 PCHAR(*p++); 668 if (ladjust && width > 0) 669 while (width--) 670 PCHAR(padc); 671 break; 672 case 'u': 673 if (qflag) 674 uq = va_arg(ap, u_quad_t); 675 else if (lflag) 676 ul = va_arg(ap, u_long); 677 else 678 ul = va_arg(ap, u_int); 679 base = 10; 680 goto nosign; 681 case 'x': 682 case 'X': 683 if (qflag) 684 uq = va_arg(ap, u_quad_t); 685 else if (lflag) 686 ul = va_arg(ap, u_long); 687 else 688 ul = va_arg(ap, u_int); 689 base = 16; 690 goto nosign; 691 case 'z': 692 if (qflag) 693 uq = va_arg(ap, u_quad_t); 694 else if (lflag) 695 ul = va_arg(ap, u_long); 696 else 697 ul = sign ? 698 (u_long)va_arg(ap, int) : va_arg(ap, u_int); 699 base = 16; 700 goto number; 701nosign: sign = 0; 702number: 703 if (qflag) { 704 if (sign && (quad_t)uq < 0) { 705 neg = 1; 706 uq = -(quad_t)uq; 707 } 708 p = ksprintqn(nbuf, uq, base, &tmp); 709 } else { 710 if (sign && (long)ul < 0) { 711 neg = 1; 712 ul = -(long)ul; 713 } 714 p = ksprintn(nbuf, ul, base, &tmp); 715 } 716 if (sharpflag && (qflag ? uq != 0 : ul != 0)) { 717 if (base == 8) 718 tmp++; 719 else if (base == 16) 720 tmp += 2; 721 } 722 if (neg) 723 tmp++; 724 725 if (!ladjust && width && (width -= tmp) > 0) 726 while (width--) 727 PCHAR(padc); 728 if (neg) 729 PCHAR('-'); 730 if (sharpflag && (qflag ? uq != 0 : ul != 0)) { 731 if (base == 8) { 732 PCHAR('0'); 733 } else if (base == 16) { 734 PCHAR('0'); 735 PCHAR('x'); 736 } 737 } 738 739 while (*p) 740 PCHAR(*p--); 741 742 if (ladjust && width && (width -= tmp) > 0) 743 while (width--) 744 PCHAR(padc); 745 746 break; 747 default: 748 PCHAR('%'); 749 if (lflag) 750 PCHAR('l'); 751 PCHAR(ch); 752 break; 753 } 754 } 755#undef PCHAR 756} 757 758/* 759 * Put character in log buffer with a particular priority. 760 */ 761static void 762msglogchar(int c, int pri) 763{ 764 static int lastpri = -1; 765 static int dangling; 766 char nbuf[MAXNBUF]; 767 char *p; 768 769 if (!msgbufmapped) 770 return; 771 if (c == '\0' || c == '\r') 772 return; 773 if (pri != -1 && pri != lastpri) { 774 if (dangling) { 775 msgaddchar('\n', NULL); 776 dangling = 0; 777 } 778 msgaddchar('<', NULL); 779 for (p = ksprintn(nbuf, (u_long)pri, 10, NULL); *p;) 780 msgaddchar(*p--, NULL); 781 msgaddchar('>', NULL); 782 lastpri = pri; 783 } 784 msgaddchar(c, NULL); 785 if (c == '\n') { 786 dangling = 0; 787 lastpri = -1; 788 } else { 789 dangling = 1; 790 } 791} 792 793/* 794 * Put char in log buffer 795 */ 796static void 797msgaddchar(int c, void *dummy) 798{ 799 struct msgbuf *mbp; 800 801 if (!msgbufmapped) 802 return; 803 mbp = msgbufp; 804 mbp->msg_ptr[mbp->msg_bufx++] = c; 805 if (mbp->msg_bufx >= mbp->msg_size) 806 mbp->msg_bufx = 0; 807 /* If the buffer is full, keep the most recent data. */ 808 if (mbp->msg_bufr == mbp->msg_bufx) { 809 if (++mbp->msg_bufr >= mbp->msg_size) 810 mbp->msg_bufr = 0; 811 } 812} 813 814static void 815msgbufcopy(struct msgbuf *oldp) 816{ 817 int pos; 818 819 pos = oldp->msg_bufr; 820 while (pos != oldp->msg_bufx) { 821 msglogchar(oldp->msg_ptr[pos], -1); 822 if (++pos >= oldp->msg_size) 823 pos = 0; 824 } 825} 826 827void 828msgbufinit(void *ptr, size_t size) 829{ 830 char *cp; 831 static struct msgbuf *oldp = NULL; 832 833 size -= sizeof(*msgbufp); 834 cp = (char *)ptr; 835 msgbufp = (struct msgbuf *) (cp + size); 836 if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size || 837 msgbufp->msg_bufx >= size || msgbufp->msg_bufr >= size) { 838 bzero(cp, size); 839 bzero(msgbufp, sizeof(*msgbufp)); 840 msgbufp->msg_magic = MSG_MAGIC; 841 msgbufp->msg_size = (char *)msgbufp - cp; 842 } 843 msgbufp->msg_ptr = cp; 844 if (msgbufmapped && oldp != msgbufp) 845 msgbufcopy(oldp); 846 msgbufmapped = 1; 847 oldp = msgbufp; 848} 849 850SYSCTL_DECL(_security_bsd); 851 852static int unprivileged_read_msgbuf = 1; 853SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_read_msgbuf, 854 CTLFLAG_RW, &unprivileged_read_msgbuf, 0, 855 "Unprivileged processes may read the kernel message buffer"); 856 857/* Sysctls for accessing/clearing the msgbuf */ 858static int 859sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS) 860{ 861 int error; 862 863 if (!unprivileged_read_msgbuf) { 864 error = suser_td(req->td); 865 if (error) 866 return (error); 867 } 868 869 /* 870 * Unwind the buffer, so that it's linear (possibly starting with 871 * some initial nulls). 872 */ 873 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr + msgbufp->msg_bufx, 874 msgbufp->msg_size - msgbufp->msg_bufx, req); 875 if (error) 876 return (error); 877 if (msgbufp->msg_bufx > 0) { 878 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr, 879 msgbufp->msg_bufx, req); 880 } 881 return (error); 882} 883 884SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD, 885 0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer"); 886 887static int msgbuf_clear; 888 889static int 890sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS) 891{ 892 int error; 893 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); 894 if (!error && req->newptr) { 895 /* Clear the buffer and reset write pointer */ 896 bzero(msgbufp->msg_ptr, msgbufp->msg_size); 897 msgbufp->msg_bufr = msgbufp->msg_bufx = 0; 898 msgbuf_clear = 0; 899 } 900 return (error); 901} 902 903SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear, 904 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0, 905 sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer"); 906 907#include "opt_ddb.h" 908#ifdef DDB 909#include <ddb/ddb.h> 910 911DB_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