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