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