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/sysctl.h> 55 #include <sys/tty.h> 56 #include <sys/syslog.h> 57 #include <sys/cons.h> 58 #include <sys/uio.h> 59 60 #ifdef DDB 61 #include <ddb/ddb.h> 62 #endif 63 64 /* 65 * Note that stdarg.h and the ANSI style va_start macro is used for both 66 * ANSI and traditional C compilers. 67 */ 68 #include <machine/stdarg.h> 69 70 #define TOCONS 0x01 71 #define TOTTY 0x02 72 #define TOLOG 0x04 73 74 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */ 75 #define MAXNBUF (sizeof(intmax_t) * NBBY + 1) 76 77 struct putchar_arg { 78 int flags; 79 int pri; 80 struct tty *tty; 81 }; 82 83 struct snprintf_arg { 84 char *str; 85 size_t remain; 86 }; 87 88 extern int log_open; 89 90 struct tty *constty; /* pointer to console "window" tty */ 91 92 static void (*v_putc)(int) = cnputc; /* routine to putc on virtual console */ 93 static void msglogchar(int c, int pri); 94 static void msgaddchar(int c, void *dummy); 95 static u_int msgbufcksum(char *cp, size_t size, u_int cksum); 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; 165 va_list ap; 166 struct putchar_arg pca; 167 struct session *sess = NULL; 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 = p->p_session; 175 SESS_LOCK(sess); 176 PROC_UNLOCK(p); 177 SESSHOLD(sess); 178 tp = sess->s_ttyp; 179 SESS_UNLOCK(sess); 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 kvprintf(fmt, putchar, &pca, 10, ap); 192 va_end(ap); 193 if (sess != NULL) { 194 SESS_LOCK(sess); 195 SESSRELE(sess); 196 SESS_UNLOCK(sess); 197 } 198 msgbuftrigger = 1; 199 } 200 201 /* 202 * Ttyprintf displays a message on a tty; it should be used only by 203 * the tty driver, or anything that knows the underlying tty will not 204 * be revoke(2)'d away. Other callers should use tprintf. 205 */ 206 int 207 ttyprintf(struct tty *tp, const char *fmt, ...) 208 { 209 va_list ap; 210 struct putchar_arg pca; 211 int retval; 212 213 va_start(ap, fmt); 214 pca.tty = tp; 215 pca.flags = TOTTY; 216 retval = kvprintf(fmt, putchar, &pca, 10, ap); 217 va_end(ap); 218 return (retval); 219 } 220 221 /* 222 * Log writes to the log buffer, and guarantees not to sleep (so can be 223 * called by interrupt routines). If there is no process reading the 224 * log yet, it writes to the console also. 225 */ 226 void 227 log(int level, const char *fmt, ...) 228 { 229 va_list ap; 230 struct putchar_arg pca; 231 232 pca.tty = NULL; 233 pca.pri = level; 234 pca.flags = log_open ? TOLOG : TOCONS; 235 236 va_start(ap, fmt); 237 kvprintf(fmt, putchar, &pca, 10, ap); 238 va_end(ap); 239 240 msgbuftrigger = 1; 241 } 242 243 #define CONSCHUNK 128 244 245 void 246 log_console(struct uio *uio) 247 { 248 int c, i, error, iovlen, nl; 249 struct uio muio; 250 struct iovec *miov = NULL; 251 char *consbuffer; 252 int pri; 253 254 if (!log_console_output) 255 return; 256 257 pri = LOG_INFO | LOG_CONSOLE; 258 muio = *uio; 259 iovlen = uio->uio_iovcnt * sizeof (struct iovec); 260 MALLOC(miov, struct iovec *, iovlen, M_TEMP, M_WAITOK); 261 MALLOC(consbuffer, char *, CONSCHUNK, M_TEMP, M_WAITOK); 262 bcopy(muio.uio_iov, miov, iovlen); 263 muio.uio_iov = miov; 264 uio = &muio; 265 266 nl = 0; 267 while (uio->uio_resid > 0) { 268 c = imin(uio->uio_resid, CONSCHUNK); 269 error = uiomove(consbuffer, c, uio); 270 if (error != 0) 271 break; 272 for (i = 0; i < c; i++) { 273 msglogchar(consbuffer[i], pri); 274 if (consbuffer[i] == '\n') 275 nl = 1; 276 else 277 nl = 0; 278 } 279 } 280 if (!nl) 281 msglogchar('\n', pri); 282 msgbuftrigger = 1; 283 FREE(miov, M_TEMP); 284 FREE(consbuffer, M_TEMP); 285 return; 286 } 287 288 int 289 printf(const char *fmt, ...) 290 { 291 va_list ap; 292 int savintr; 293 struct putchar_arg pca; 294 int retval; 295 296 savintr = consintr; /* disable interrupts */ 297 consintr = 0; 298 va_start(ap, fmt); 299 pca.tty = NULL; 300 pca.flags = TOCONS | TOLOG; 301 pca.pri = -1; 302 retval = kvprintf(fmt, putchar, &pca, 10, ap); 303 va_end(ap); 304 if (!panicstr) 305 msgbuftrigger = 1; 306 consintr = savintr; /* reenable interrupts */ 307 return (retval); 308 } 309 310 int 311 vprintf(const char *fmt, va_list ap) 312 { 313 int savintr; 314 struct putchar_arg pca; 315 int retval; 316 317 savintr = consintr; /* disable interrupts */ 318 consintr = 0; 319 pca.tty = NULL; 320 pca.flags = TOCONS | TOLOG; 321 pca.pri = -1; 322 retval = kvprintf(fmt, putchar, &pca, 10, ap); 323 if (!panicstr) 324 msgbuftrigger = 1; 325 consintr = savintr; /* reenable interrupts */ 326 return (retval); 327 } 328 329 /* 330 * Print a character on console or users terminal. If destination is 331 * the console then the last bunch of characters are saved in msgbuf for 332 * inspection later. 333 */ 334 static void 335 putchar(int c, void *arg) 336 { 337 struct putchar_arg *ap = (struct putchar_arg*) arg; 338 int flags = ap->flags; 339 struct tty *tp = ap->tty; 340 if (panicstr) 341 constty = NULL; 342 if ((flags & TOCONS) && tp == NULL && constty) { 343 tp = constty; 344 flags |= TOTTY; 345 } 346 if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 && 347 (flags & TOCONS) && tp == constty) 348 constty = NULL; 349 if ((flags & TOLOG)) 350 msglogchar(c, ap->pri); 351 if ((flags & TOCONS) && constty == NULL && c != '\0') 352 (*v_putc)(c); 353 } 354 355 /* 356 * Scaled down version of sprintf(3). 357 */ 358 int 359 sprintf(char *buf, const char *cfmt, ...) 360 { 361 int retval; 362 va_list ap; 363 364 va_start(ap, cfmt); 365 retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap); 366 buf[retval] = '\0'; 367 va_end(ap); 368 return (retval); 369 } 370 371 /* 372 * Scaled down version of vsprintf(3). 373 */ 374 int 375 vsprintf(char *buf, const char *cfmt, va_list ap) 376 { 377 int retval; 378 379 retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap); 380 buf[retval] = '\0'; 381 return (retval); 382 } 383 384 /* 385 * Scaled down version of snprintf(3). 386 */ 387 int 388 snprintf(char *str, size_t size, const char *format, ...) 389 { 390 int retval; 391 va_list ap; 392 393 va_start(ap, format); 394 retval = vsnprintf(str, size, format, ap); 395 va_end(ap); 396 return(retval); 397 } 398 399 /* 400 * Scaled down version of vsnprintf(3). 401 */ 402 int 403 vsnprintf(char *str, size_t size, const char *format, va_list ap) 404 { 405 struct snprintf_arg info; 406 int retval; 407 408 info.str = str; 409 info.remain = size; 410 retval = kvprintf(format, snprintf_func, &info, 10, ap); 411 if (info.remain >= 1) 412 *info.str++ = '\0'; 413 return (retval); 414 } 415 416 /* 417 * Kernel version which takes radix argument vsnprintf(3). 418 */ 419 int 420 vsnrprintf(char *str, size_t size, int radix, const char *format, va_list ap) 421 { 422 struct snprintf_arg info; 423 int retval; 424 425 info.str = str; 426 info.remain = size; 427 retval = kvprintf(format, snprintf_func, &info, radix, ap); 428 if (info.remain >= 1) 429 *info.str++ = '\0'; 430 return (retval); 431 } 432 433 static void 434 snprintf_func(int ch, void *arg) 435 { 436 struct snprintf_arg *const info = arg; 437 438 if (info->remain >= 2) { 439 *info->str++ = ch; 440 info->remain--; 441 } 442 } 443 444 /* 445 * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse 446 * order; return an optional length and a pointer to the last character 447 * written in the buffer (i.e., the first character of the string). 448 * The buffer pointed to by `nbuf' must have length >= MAXNBUF. 449 */ 450 static char * 451 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp) 452 { 453 char *p; 454 455 p = nbuf; 456 *p = '\0'; 457 do { 458 *++p = hex2ascii(num % base); 459 } while (num /= base); 460 if (lenp) 461 *lenp = p - nbuf; 462 return (p); 463 } 464 465 /* 466 * Scaled down version of printf(3). 467 * 468 * Two additional formats: 469 * 470 * The format %b is supported to decode error registers. 471 * Its usage is: 472 * 473 * printf("reg=%b\n", regval, "<base><arg>*"); 474 * 475 * where <base> is the output base expressed as a control character, e.g. 476 * \10 gives octal; \20 gives hex. Each arg is a sequence of characters, 477 * the first of which gives the bit number to be inspected (origin 1), and 478 * the next characters (up to a control character, i.e. a character <= 32), 479 * give the name of the register. Thus: 480 * 481 * kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n"); 482 * 483 * would produce output: 484 * 485 * reg=3<BITTWO,BITONE> 486 * 487 * XXX: %D -- Hexdump, takes pointer and separator string: 488 * ("%6D", ptr, ":") -> XX:XX:XX:XX:XX:XX 489 * ("%*D", len, ptr, " " -> XX XX XX XX ... 490 */ 491 int 492 kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap) 493 { 494 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; } 495 char nbuf[MAXNBUF]; 496 char *d; 497 const char *p, *percent, *q; 498 u_char *up; 499 int ch, n; 500 uintmax_t num; 501 int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot; 502 int jflag, tflag, zflag; 503 int dwidth; 504 char padc; 505 int retval = 0; 506 507 num = 0; 508 if (!func) 509 d = (char *) arg; 510 else 511 d = NULL; 512 513 if (fmt == NULL) 514 fmt = "(fmt null)\n"; 515 516 if (radix < 2 || radix > 36) 517 radix = 10; 518 519 for (;;) { 520 padc = ' '; 521 width = 0; 522 while ((ch = (u_char)*fmt++) != '%') { 523 if (ch == '\0') 524 return (retval); 525 PCHAR(ch); 526 } 527 percent = fmt - 1; 528 qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0; 529 sign = 0; dot = 0; dwidth = 0; 530 jflag = 0; tflag = 0; zflag = 0; 531 reswitch: switch (ch = (u_char)*fmt++) { 532 case '.': 533 dot = 1; 534 goto reswitch; 535 case '#': 536 sharpflag = 1; 537 goto reswitch; 538 case '+': 539 sign = 1; 540 goto reswitch; 541 case '-': 542 ladjust = 1; 543 goto reswitch; 544 case '%': 545 PCHAR(ch); 546 break; 547 case '*': 548 if (!dot) { 549 width = va_arg(ap, int); 550 if (width < 0) { 551 ladjust = !ladjust; 552 width = -width; 553 } 554 } else { 555 dwidth = va_arg(ap, int); 556 } 557 goto reswitch; 558 case '0': 559 if (!dot) { 560 padc = '0'; 561 goto reswitch; 562 } 563 case '1': case '2': case '3': case '4': 564 case '5': case '6': case '7': case '8': case '9': 565 for (n = 0;; ++fmt) { 566 n = n * 10 + ch - '0'; 567 ch = *fmt; 568 if (ch < '0' || ch > '9') 569 break; 570 } 571 if (dot) 572 dwidth = n; 573 else 574 width = n; 575 goto reswitch; 576 case 'b': 577 num = (u_int)va_arg(ap, int); 578 p = va_arg(ap, char *); 579 for (q = ksprintn(nbuf, num, *p++, NULL); *q;) 580 PCHAR(*q--); 581 582 if (num == 0) 583 break; 584 585 for (tmp = 0; *p;) { 586 n = *p++; 587 if (num & (1 << (n - 1))) { 588 PCHAR(tmp ? ',' : '<'); 589 for (; (n = *p) > ' '; ++p) 590 PCHAR(n); 591 tmp = 1; 592 } else 593 for (; *p > ' '; ++p) 594 continue; 595 } 596 if (tmp) 597 PCHAR('>'); 598 break; 599 case 'c': 600 PCHAR(va_arg(ap, int)); 601 break; 602 case 'D': 603 up = va_arg(ap, u_char *); 604 p = va_arg(ap, char *); 605 if (!width) 606 width = 16; 607 while(width--) { 608 PCHAR(hex2ascii(*up >> 4)); 609 PCHAR(hex2ascii(*up & 0x0f)); 610 up++; 611 if (width) 612 for (q=p;*q;q++) 613 PCHAR(*q); 614 } 615 break; 616 case 'd': 617 case 'i': 618 base = 10; 619 sign = 1; 620 goto handle_sign; 621 case 'j': 622 jflag = 1; 623 goto reswitch; 624 case 'l': 625 if (lflag) { 626 lflag = 0; 627 qflag = 1; 628 } else 629 lflag = 1; 630 goto reswitch; 631 case 'n': 632 if (jflag) 633 *(va_arg(ap, intmax_t *)) = retval; 634 else if (qflag) 635 *(va_arg(ap, quad_t *)) = retval; 636 else if (lflag) 637 *(va_arg(ap, long *)) = retval; 638 else if (zflag) 639 *(va_arg(ap, size_t *)) = retval; 640 else 641 *(va_arg(ap, int *)) = retval; 642 break; 643 case 'o': 644 base = 8; 645 goto handle_nosign; 646 case 'p': 647 base = 16; 648 sharpflag = (width == 0); 649 sign = 0; 650 num = (uintptr_t)va_arg(ap, void *); 651 goto number; 652 case 'q': 653 qflag = 1; 654 goto reswitch; 655 case 'r': 656 base = radix; 657 if (sign) 658 goto handle_sign; 659 goto handle_nosign; 660 case 's': 661 p = va_arg(ap, char *); 662 if (p == NULL) 663 p = "(null)"; 664 if (!dot) 665 n = strlen (p); 666 else 667 for (n = 0; n < dwidth && p[n]; n++) 668 continue; 669 670 width -= n; 671 672 if (!ladjust && width > 0) 673 while (width--) 674 PCHAR(padc); 675 while (n--) 676 PCHAR(*p++); 677 if (ladjust && width > 0) 678 while (width--) 679 PCHAR(padc); 680 break; 681 case 't': 682 tflag = 1; 683 goto reswitch; 684 case 'u': 685 base = 10; 686 goto handle_nosign; 687 case 'x': 688 case 'X': 689 base = 16; 690 goto handle_nosign; 691 case 'y': 692 base = 16; 693 sign = 1; 694 goto handle_sign; 695 case 'z': 696 zflag = 1; 697 goto reswitch; 698 handle_nosign: 699 sign = 0; 700 if (jflag) 701 num = va_arg(ap, uintmax_t); 702 else if (qflag) 703 num = va_arg(ap, u_quad_t); 704 else if (tflag) 705 num = va_arg(ap, ptrdiff_t); 706 else if (lflag) 707 num = va_arg(ap, u_long); 708 else if (zflag) 709 num = va_arg(ap, size_t); 710 else 711 num = va_arg(ap, u_int); 712 goto number; 713 handle_sign: 714 if (jflag) 715 num = va_arg(ap, intmax_t); 716 else if (qflag) 717 num = va_arg(ap, quad_t); 718 else if (tflag) 719 num = va_arg(ap, ptrdiff_t); 720 else if (lflag) 721 num = va_arg(ap, long); 722 else if (zflag) 723 num = va_arg(ap, size_t); 724 else 725 num = va_arg(ap, int); 726 number: 727 if (sign && (intmax_t)num < 0) { 728 neg = 1; 729 num = -(intmax_t)num; 730 } 731 p = ksprintn(nbuf, num, base, &tmp); 732 if (sharpflag && num != 0) { 733 if (base == 8) 734 tmp++; 735 else if (base == 16) 736 tmp += 2; 737 } 738 if (neg) 739 tmp++; 740 741 if (!ladjust && width && (width -= tmp) > 0) 742 while (width--) 743 PCHAR(padc); 744 if (neg) 745 PCHAR('-'); 746 if (sharpflag && num != 0) { 747 if (base == 8) { 748 PCHAR('0'); 749 } else if (base == 16) { 750 PCHAR('0'); 751 PCHAR('x'); 752 } 753 } 754 755 while (*p) 756 PCHAR(*p--); 757 758 if (ladjust && width && (width -= tmp) > 0) 759 while (width--) 760 PCHAR(padc); 761 762 break; 763 default: 764 while (percent < fmt) 765 PCHAR(*percent++); 766 break; 767 } 768 } 769 #undef PCHAR 770 } 771 772 /* 773 * Put character in log buffer with a particular priority. 774 */ 775 static void 776 msglogchar(int c, int pri) 777 { 778 static int lastpri = -1; 779 static int dangling; 780 char nbuf[MAXNBUF]; 781 char *p; 782 783 if (!msgbufmapped) 784 return; 785 if (c == '\0' || c == '\r') 786 return; 787 if (pri != -1 && pri != lastpri) { 788 if (dangling) { 789 msgaddchar('\n', NULL); 790 dangling = 0; 791 } 792 msgaddchar('<', NULL); 793 for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL); *p;) 794 msgaddchar(*p--, NULL); 795 msgaddchar('>', NULL); 796 lastpri = pri; 797 } 798 msgaddchar(c, NULL); 799 if (c == '\n') { 800 dangling = 0; 801 lastpri = -1; 802 } else { 803 dangling = 1; 804 } 805 } 806 807 /* 808 * Put char in log buffer 809 */ 810 static void 811 msgaddchar(int c, void *dummy) 812 { 813 struct msgbuf *mbp; 814 815 if (!msgbufmapped) 816 return; 817 mbp = msgbufp; 818 mbp->msg_cksum += (u_char)c - (u_char)mbp->msg_ptr[mbp->msg_bufx]; 819 mbp->msg_ptr[mbp->msg_bufx++] = c; 820 if (mbp->msg_bufx >= mbp->msg_size) 821 mbp->msg_bufx = 0; 822 /* If the buffer is full, keep the most recent data. */ 823 if (mbp->msg_bufr == mbp->msg_bufx) { 824 if (++mbp->msg_bufr >= mbp->msg_size) 825 mbp->msg_bufr = 0; 826 } 827 } 828 829 static void 830 msgbufcopy(struct msgbuf *oldp) 831 { 832 int pos; 833 834 pos = oldp->msg_bufr; 835 while (pos != oldp->msg_bufx) { 836 msglogchar(oldp->msg_ptr[pos], -1); 837 if (++pos >= oldp->msg_size) 838 pos = 0; 839 } 840 } 841 842 void 843 msgbufinit(void *ptr, int size) 844 { 845 char *cp; 846 static struct msgbuf *oldp = NULL; 847 848 size -= sizeof(*msgbufp); 849 cp = (char *)ptr; 850 msgbufp = (struct msgbuf *) (cp + size); 851 if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size || 852 msgbufp->msg_bufx >= size || msgbufp->msg_bufx < 0 || 853 msgbufp->msg_bufr >= size || msgbufp->msg_bufr < 0 || 854 msgbufcksum(cp, size, msgbufp->msg_cksum) != msgbufp->msg_cksum) { 855 bzero(cp, size); 856 bzero(msgbufp, sizeof(*msgbufp)); 857 msgbufp->msg_magic = MSG_MAGIC; 858 msgbufp->msg_size = size; 859 } 860 msgbufp->msg_ptr = cp; 861 if (msgbufmapped && oldp != msgbufp) 862 msgbufcopy(oldp); 863 msgbufmapped = 1; 864 oldp = msgbufp; 865 } 866 867 static u_int 868 msgbufcksum(char *cp, size_t size, u_int cksum) 869 { 870 u_int sum; 871 int i; 872 873 sum = 0; 874 for (i = 0; i < size; i++) 875 sum += (u_char)cp[i]; 876 if (sum != cksum) 877 printf("msgbuf cksum mismatch (read %x, calc %x)\n", cksum, 878 sum); 879 880 return (sum); 881 } 882 883 SYSCTL_DECL(_security_bsd); 884 885 static int unprivileged_read_msgbuf = 1; 886 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_read_msgbuf, 887 CTLFLAG_RW, &unprivileged_read_msgbuf, 0, 888 "Unprivileged processes may read the kernel message buffer"); 889 890 /* Sysctls for accessing/clearing the msgbuf */ 891 static int 892 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS) 893 { 894 int error; 895 896 if (!unprivileged_read_msgbuf) { 897 error = suser(req->td); 898 if (error) 899 return (error); 900 } 901 902 /* 903 * Unwind the buffer, so that it's linear (possibly starting with 904 * some initial nulls). 905 */ 906 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr + msgbufp->msg_bufx, 907 msgbufp->msg_size - msgbufp->msg_bufx, req); 908 if (error) 909 return (error); 910 if (msgbufp->msg_bufx > 0) { 911 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr, 912 msgbufp->msg_bufx, req); 913 } 914 return (error); 915 } 916 917 SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD, 918 0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer"); 919 920 static int msgbuf_clear; 921 922 static int 923 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS) 924 { 925 int error; 926 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); 927 if (!error && req->newptr) { 928 /* Clear the buffer and reset write pointer */ 929 bzero(msgbufp->msg_ptr, msgbufp->msg_size); 930 msgbufp->msg_bufr = msgbufp->msg_bufx = 0; 931 msgbufp->msg_cksum = 0; 932 msgbuf_clear = 0; 933 } 934 return (error); 935 } 936 937 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear, 938 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0, 939 sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer"); 940 941 #ifdef DDB 942 943 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf) 944 { 945 int i, j; 946 947 if (!msgbufmapped) { 948 db_printf("msgbuf not mapped yet\n"); 949 return; 950 } 951 db_printf("msgbufp = %p\n", msgbufp); 952 db_printf("magic = %x, size = %d, r= %d, w = %d, ptr = %p, cksum= %d\n", 953 msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_bufr, 954 msgbufp->msg_bufx, msgbufp->msg_ptr, msgbufp->msg_cksum); 955 for (i = 0; i < msgbufp->msg_size; i++) { 956 j = (i + msgbufp->msg_bufr) % msgbufp->msg_size; 957 db_printf("%c", msgbufp->msg_ptr[j]); 958 } 959 db_printf("\n"); 960 } 961 962 #endif /* DDB */ 963