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, 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, M_WAITOK); 264 MALLOC(consbuffer, char *, CONSCHUNK, M_TEMP, M_WAITOK); 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 /* 420 * Kernel version which takes radix argument vsnprintf(3). 421 */ 422 int 423 vsnrprintf(char *str, size_t size, int radix, const char *format, va_list ap) 424 { 425 struct snprintf_arg info; 426 int retval; 427 428 info.str = str; 429 info.remain = size; 430 retval = kvprintf(format, snprintf_func, &info, radix, ap); 431 if (info.remain >= 1) 432 *info.str++ = '\0'; 433 return (retval); 434 } 435 436 static void 437 snprintf_func(int ch, void *arg) 438 { 439 struct snprintf_arg *const info = arg; 440 441 if (info->remain >= 2) { 442 *info->str++ = ch; 443 info->remain--; 444 } 445 } 446 447 /* 448 * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse 449 * order; return an optional length and a pointer to the last character 450 * written in the buffer (i.e., the first character of the string). 451 * The buffer pointed to by `nbuf' must have length >= MAXNBUF. 452 */ 453 static char * 454 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp) 455 { 456 char *p; 457 458 p = nbuf; 459 *p = '\0'; 460 do { 461 *++p = hex2ascii(num % base); 462 } while (num /= base); 463 if (lenp) 464 *lenp = p - nbuf; 465 return (p); 466 } 467 468 /* 469 * Scaled down version of printf(3). 470 * 471 * Two additional formats: 472 * 473 * The format %b is supported to decode error registers. 474 * Its usage is: 475 * 476 * printf("reg=%b\n", regval, "<base><arg>*"); 477 * 478 * where <base> is the output base expressed as a control character, e.g. 479 * \10 gives octal; \20 gives hex. Each arg is a sequence of characters, 480 * the first of which gives the bit number to be inspected (origin 1), and 481 * the next characters (up to a control character, i.e. a character <= 32), 482 * give the name of the register. Thus: 483 * 484 * kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n"); 485 * 486 * would produce output: 487 * 488 * reg=3<BITTWO,BITONE> 489 * 490 * XXX: %D -- Hexdump, takes pointer and separator string: 491 * ("%6D", ptr, ":") -> XX:XX:XX:XX:XX:XX 492 * ("%*D", len, ptr, " " -> XX XX XX XX ... 493 */ 494 int 495 kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap) 496 { 497 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; } 498 char nbuf[MAXNBUF]; 499 char *d; 500 const char *p, *percent, *q; 501 u_char *up; 502 int ch, n; 503 uintmax_t num; 504 int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot; 505 int jflag, tflag, zflag; 506 int dwidth; 507 char padc; 508 int retval = 0; 509 510 num = 0; 511 if (!func) 512 d = (char *) arg; 513 else 514 d = NULL; 515 516 if (fmt == NULL) 517 fmt = "(fmt null)\n"; 518 519 if (radix < 2 || radix > 36) 520 radix = 10; 521 522 for (;;) { 523 padc = ' '; 524 width = 0; 525 while ((ch = (u_char)*fmt++) != '%') { 526 if (ch == '\0') 527 return (retval); 528 PCHAR(ch); 529 } 530 percent = fmt - 1; 531 qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0; 532 sign = 0; dot = 0; dwidth = 0; 533 jflag = 0; tflag = 0; zflag = 0; 534 reswitch: switch (ch = (u_char)*fmt++) { 535 case '.': 536 dot = 1; 537 goto reswitch; 538 case '#': 539 sharpflag = 1; 540 goto reswitch; 541 case '+': 542 sign = 1; 543 goto reswitch; 544 case '-': 545 ladjust = 1; 546 goto reswitch; 547 case '%': 548 PCHAR(ch); 549 break; 550 case '*': 551 if (!dot) { 552 width = va_arg(ap, int); 553 if (width < 0) { 554 ladjust = !ladjust; 555 width = -width; 556 } 557 } else { 558 dwidth = va_arg(ap, int); 559 } 560 goto reswitch; 561 case '0': 562 if (!dot) { 563 padc = '0'; 564 goto reswitch; 565 } 566 case '1': case '2': case '3': case '4': 567 case '5': case '6': case '7': case '8': case '9': 568 for (n = 0;; ++fmt) { 569 n = n * 10 + ch - '0'; 570 ch = *fmt; 571 if (ch < '0' || ch > '9') 572 break; 573 } 574 if (dot) 575 dwidth = n; 576 else 577 width = n; 578 goto reswitch; 579 case 'b': 580 num = (u_int)va_arg(ap, int); 581 p = va_arg(ap, char *); 582 for (q = ksprintn(nbuf, num, *p++, NULL); *q;) 583 PCHAR(*q--); 584 585 if (num == 0) 586 break; 587 588 for (tmp = 0; *p;) { 589 n = *p++; 590 if (num & (1 << (n - 1))) { 591 PCHAR(tmp ? ',' : '<'); 592 for (; (n = *p) > ' '; ++p) 593 PCHAR(n); 594 tmp = 1; 595 } else 596 for (; *p > ' '; ++p) 597 continue; 598 } 599 if (tmp) 600 PCHAR('>'); 601 break; 602 case 'c': 603 PCHAR(va_arg(ap, int)); 604 break; 605 case 'D': 606 up = va_arg(ap, u_char *); 607 p = va_arg(ap, char *); 608 if (!width) 609 width = 16; 610 while(width--) { 611 PCHAR(hex2ascii(*up >> 4)); 612 PCHAR(hex2ascii(*up & 0x0f)); 613 up++; 614 if (width) 615 for (q=p;*q;q++) 616 PCHAR(*q); 617 } 618 break; 619 case 'd': 620 case 'i': 621 base = 10; 622 sign = 1; 623 goto handle_sign; 624 case 'j': 625 jflag = 1; 626 goto reswitch; 627 case 'l': 628 if (lflag) { 629 lflag = 0; 630 qflag = 1; 631 } else 632 lflag = 1; 633 goto reswitch; 634 case 'n': 635 if (jflag) 636 *(va_arg(ap, intmax_t *)) = retval; 637 else if (qflag) 638 *(va_arg(ap, quad_t *)) = retval; 639 else if (lflag) 640 *(va_arg(ap, long *)) = retval; 641 else if (zflag) 642 *(va_arg(ap, size_t *)) = retval; 643 else 644 *(va_arg(ap, int *)) = retval; 645 break; 646 case 'o': 647 base = 8; 648 goto handle_nosign; 649 case 'p': 650 base = 16; 651 sharpflag = (width == 0); 652 sign = 0; 653 num = (uintptr_t)va_arg(ap, void *); 654 goto number; 655 case 'q': 656 qflag = 1; 657 goto reswitch; 658 case 'r': 659 base = radix; 660 if (sign) 661 goto handle_sign; 662 goto handle_nosign; 663 case 's': 664 p = va_arg(ap, char *); 665 if (p == NULL) 666 p = "(null)"; 667 if (!dot) 668 n = strlen (p); 669 else 670 for (n = 0; n < dwidth && p[n]; n++) 671 continue; 672 673 width -= n; 674 675 if (!ladjust && width > 0) 676 while (width--) 677 PCHAR(padc); 678 while (n--) 679 PCHAR(*p++); 680 if (ladjust && width > 0) 681 while (width--) 682 PCHAR(padc); 683 break; 684 case 't': 685 tflag = 1; 686 goto reswitch; 687 break; 688 case 'u': 689 base = 10; 690 goto handle_nosign; 691 case 'x': 692 case 'X': 693 base = 16; 694 goto handle_nosign; 695 case 'y': 696 base = 16; 697 sign = 1; 698 goto handle_sign; 699 case 'z': 700 zflag = 1; 701 goto reswitch; 702 handle_nosign: 703 sign = 0; 704 if (jflag) 705 num = va_arg(ap, uintmax_t); 706 else if (qflag) 707 num = va_arg(ap, u_quad_t); 708 else if (tflag) 709 num = va_arg(ap, ptrdiff_t); 710 else if (lflag) 711 num = va_arg(ap, u_long); 712 else if (zflag) 713 num = va_arg(ap, size_t); 714 else 715 num = va_arg(ap, u_int); 716 goto number; 717 handle_sign: 718 if (jflag) 719 num = va_arg(ap, intmax_t); 720 else if (qflag) 721 num = va_arg(ap, quad_t); 722 else if (tflag) 723 num = va_arg(ap, ptrdiff_t); 724 else if (lflag) 725 num = va_arg(ap, long); 726 else if (zflag) 727 num = va_arg(ap, size_t); 728 else 729 num = va_arg(ap, int); 730 number: 731 if (sign && (intmax_t)num < 0) { 732 neg = 1; 733 num = -(intmax_t)num; 734 } 735 p = ksprintn(nbuf, num, base, &tmp); 736 if (sharpflag && num != 0) { 737 if (base == 8) 738 tmp++; 739 else if (base == 16) 740 tmp += 2; 741 } 742 if (neg) 743 tmp++; 744 745 if (!ladjust && width && (width -= tmp) > 0) 746 while (width--) 747 PCHAR(padc); 748 if (neg) 749 PCHAR('-'); 750 if (sharpflag && num != 0) { 751 if (base == 8) { 752 PCHAR('0'); 753 } else if (base == 16) { 754 PCHAR('0'); 755 PCHAR('x'); 756 } 757 } 758 759 while (*p) 760 PCHAR(*p--); 761 762 if (ladjust && width && (width -= tmp) > 0) 763 while (width--) 764 PCHAR(padc); 765 766 break; 767 default: 768 while (percent < fmt) 769 PCHAR(*percent++); 770 break; 771 } 772 } 773 #undef PCHAR 774 } 775 776 /* 777 * Put character in log buffer with a particular priority. 778 */ 779 static void 780 msglogchar(int c, int pri) 781 { 782 static int lastpri = -1; 783 static int dangling; 784 char nbuf[MAXNBUF]; 785 char *p; 786 787 if (!msgbufmapped) 788 return; 789 if (c == '\0' || c == '\r') 790 return; 791 if (pri != -1 && pri != lastpri) { 792 if (dangling) { 793 msgaddchar('\n', NULL); 794 dangling = 0; 795 } 796 msgaddchar('<', NULL); 797 for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL); *p;) 798 msgaddchar(*p--, NULL); 799 msgaddchar('>', NULL); 800 lastpri = pri; 801 } 802 msgaddchar(c, NULL); 803 if (c == '\n') { 804 dangling = 0; 805 lastpri = -1; 806 } else { 807 dangling = 1; 808 } 809 } 810 811 /* 812 * Put char in log buffer 813 */ 814 static void 815 msgaddchar(int c, void *dummy) 816 { 817 struct msgbuf *mbp; 818 819 if (!msgbufmapped) 820 return; 821 mbp = msgbufp; 822 mbp->msg_cksum += (u_char)c - (u_char)mbp->msg_ptr[mbp->msg_bufx]; 823 mbp->msg_ptr[mbp->msg_bufx++] = c; 824 if (mbp->msg_bufx >= mbp->msg_size) 825 mbp->msg_bufx = 0; 826 /* If the buffer is full, keep the most recent data. */ 827 if (mbp->msg_bufr == mbp->msg_bufx) { 828 if (++mbp->msg_bufr >= mbp->msg_size) 829 mbp->msg_bufr = 0; 830 } 831 } 832 833 static void 834 msgbufcopy(struct msgbuf *oldp) 835 { 836 int pos; 837 838 pos = oldp->msg_bufr; 839 while (pos != oldp->msg_bufx) { 840 msglogchar(oldp->msg_ptr[pos], -1); 841 if (++pos >= oldp->msg_size) 842 pos = 0; 843 } 844 } 845 846 void 847 msgbufinit(void *ptr, int size) 848 { 849 char *cp; 850 static struct msgbuf *oldp = NULL; 851 852 size -= sizeof(*msgbufp); 853 cp = (char *)ptr; 854 msgbufp = (struct msgbuf *) (cp + size); 855 if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size || 856 msgbufp->msg_bufx >= size || msgbufp->msg_bufx < 0 || 857 msgbufp->msg_bufr >= size || msgbufp->msg_bufr < 0 || 858 msgbufcksum(cp, size, msgbufp->msg_cksum) != msgbufp->msg_cksum) { 859 bzero(cp, size); 860 bzero(msgbufp, sizeof(*msgbufp)); 861 msgbufp->msg_magic = MSG_MAGIC; 862 msgbufp->msg_size = size; 863 } 864 msgbufp->msg_ptr = cp; 865 if (msgbufmapped && oldp != msgbufp) 866 msgbufcopy(oldp); 867 msgbufmapped = 1; 868 oldp = msgbufp; 869 } 870 871 static u_int 872 msgbufcksum(char *cp, size_t size, u_int cksum) 873 { 874 u_int sum; 875 int i; 876 877 sum = 0; 878 for (i = 0; i < size; i++) 879 sum += (u_char)cp[i]; 880 if (sum != cksum) 881 printf("msgbuf cksum mismatch (read %x, calc %x)\n", cksum, 882 sum); 883 884 return (sum); 885 } 886 887 SYSCTL_DECL(_security_bsd); 888 889 static int unprivileged_read_msgbuf = 1; 890 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_read_msgbuf, 891 CTLFLAG_RW, &unprivileged_read_msgbuf, 0, 892 "Unprivileged processes may read the kernel message buffer"); 893 894 /* Sysctls for accessing/clearing the msgbuf */ 895 static int 896 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS) 897 { 898 int error; 899 900 if (!unprivileged_read_msgbuf) { 901 error = suser(req->td); 902 if (error) 903 return (error); 904 } 905 906 /* 907 * Unwind the buffer, so that it's linear (possibly starting with 908 * some initial nulls). 909 */ 910 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr + msgbufp->msg_bufx, 911 msgbufp->msg_size - msgbufp->msg_bufx, req); 912 if (error) 913 return (error); 914 if (msgbufp->msg_bufx > 0) { 915 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr, 916 msgbufp->msg_bufx, req); 917 } 918 return (error); 919 } 920 921 SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD, 922 0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer"); 923 924 static int msgbuf_clear; 925 926 static int 927 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS) 928 { 929 int error; 930 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); 931 if (!error && req->newptr) { 932 /* Clear the buffer and reset write pointer */ 933 bzero(msgbufp->msg_ptr, msgbufp->msg_size); 934 msgbufp->msg_bufr = msgbufp->msg_bufx = 0; 935 msgbufp->msg_cksum = 0; 936 msgbuf_clear = 0; 937 } 938 return (error); 939 } 940 941 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear, 942 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0, 943 sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer"); 944 945 #ifdef DDB 946 947 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf) 948 { 949 int i, j; 950 951 if (!msgbufmapped) { 952 db_printf("msgbuf not mapped yet\n"); 953 return; 954 } 955 db_printf("msgbufp = %p\n", msgbufp); 956 db_printf("magic = %x, size = %d, r= %d, w = %d, ptr = %p, cksum= %d\n", 957 msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_bufr, 958 msgbufp->msg_bufx, msgbufp->msg_ptr, msgbufp->msg_cksum); 959 for (i = 0; i < msgbufp->msg_size; i++) { 960 j = (i + msgbufp->msg_bufr) % msgbufp->msg_size; 961 db_printf("%c", msgbufp->msg_ptr[j]); 962 } 963 db_printf("\n"); 964 } 965 966 #endif /* DDB */ 967