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 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include "opt_ddb.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/lock.h> 49 #include <sys/mutex.h> 50 #include <sys/sx.h> 51 #include <sys/kernel.h> 52 #include <sys/msgbuf.h> 53 #include <sys/malloc.h> 54 #include <sys/proc.h> 55 #include <sys/stddef.h> 56 #include <sys/sysctl.h> 57 #include <sys/tty.h> 58 #include <sys/syslog.h> 59 #include <sys/cons.h> 60 #include <sys/uio.h> 61 62 #ifdef DDB 63 #include <ddb/ddb.h> 64 #endif 65 66 /* 67 * Note that stdarg.h and the ANSI style va_start macro is used for both 68 * ANSI and traditional C compilers. 69 */ 70 #include <machine/stdarg.h> 71 72 #define TOCONS 0x01 73 #define TOTTY 0x02 74 #define TOLOG 0x04 75 76 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */ 77 #define MAXNBUF (sizeof(intmax_t) * NBBY + 1) 78 79 struct putchar_arg { 80 int flags; 81 int pri; 82 struct tty *tty; 83 }; 84 85 struct snprintf_arg { 86 char *str; 87 size_t remain; 88 }; 89 90 extern int log_open; 91 92 struct tty *constty; /* pointer to console "window" tty */ 93 94 static void (*v_putc)(int) = cnputc; /* routine to putc on virtual console */ 95 static void msglogchar(int c, int pri); 96 static void msgaddchar(int c, void *dummy); 97 static u_int msgbufcksum(char *cp, size_t size, u_int cksum); 98 static void putchar(int ch, void *arg); 99 static char *ksprintn(char *nbuf, uintmax_t num, int base, int *len); 100 static void snprintf_func(int ch, void *arg); 101 102 static int consintr = 1; /* Ok to handle console interrupts? */ 103 static int msgbufmapped; /* Set when safe to use msgbuf */ 104 int msgbuftrigger; 105 106 static int log_console_output = 1; 107 TUNABLE_INT("kern.log_console_output", &log_console_output); 108 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW, 109 &log_console_output, 0, ""); 110 111 /* 112 * Warn that a system table is full. 113 */ 114 void 115 tablefull(const char *tab) 116 { 117 118 log(LOG_ERR, "%s: table is full\n", tab); 119 } 120 121 /* 122 * Uprintf prints to the controlling terminal for the current process. 123 * It may block if the tty queue is overfull. No message is printed if 124 * the queue does not clear in a reasonable time. 125 */ 126 int 127 uprintf(const char *fmt, ...) 128 { 129 struct thread *td = curthread; 130 struct proc *p = td->td_proc; 131 va_list ap; 132 struct putchar_arg pca; 133 int retval; 134 135 if (td == NULL || td == PCPU_GET(idlethread)) 136 return (0); 137 138 p = td->td_proc; 139 PROC_LOCK(p); 140 if ((p->p_flag & P_CONTROLT) == 0) { 141 PROC_UNLOCK(p); 142 return (0); 143 } 144 SESS_LOCK(p->p_session); 145 pca.tty = p->p_session->s_ttyp; 146 SESS_UNLOCK(p->p_session); 147 PROC_UNLOCK(p); 148 if (pca.tty == NULL) 149 return (0); 150 pca.flags = TOTTY; 151 va_start(ap, fmt); 152 retval = kvprintf(fmt, putchar, &pca, 10, ap); 153 va_end(ap); 154 155 return (retval); 156 } 157 158 /* 159 * tprintf prints on the controlling terminal associated 160 * with the given session, possibly to the log as well. 161 */ 162 void 163 tprintf(struct proc *p, int pri, const char *fmt, ...) 164 { 165 struct tty *tp = NULL; 166 int flags = 0; 167 va_list ap; 168 struct putchar_arg pca; 169 struct session *sess = NULL; 170 171 if (pri != -1) 172 flags |= TOLOG; 173 if (p != NULL) { 174 PROC_LOCK(p); 175 if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) { 176 sess = p->p_session; 177 SESS_LOCK(sess); 178 PROC_UNLOCK(p); 179 SESSHOLD(sess); 180 tp = sess->s_ttyp; 181 SESS_UNLOCK(sess); 182 if (ttycheckoutq(tp, 0)) 183 flags |= TOTTY; 184 else 185 tp = NULL; 186 } else 187 PROC_UNLOCK(p); 188 } 189 pca.pri = pri; 190 pca.tty = tp; 191 pca.flags = flags; 192 va_start(ap, fmt); 193 kvprintf(fmt, putchar, &pca, 10, ap); 194 va_end(ap); 195 if (sess != NULL) { 196 SESS_LOCK(sess); 197 SESSRELE(sess); 198 SESS_UNLOCK(sess); 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 struct putchar_arg pca; 233 234 pca.tty = NULL; 235 pca.pri = level; 236 pca.flags = log_open ? TOLOG : TOCONS; 237 238 va_start(ap, fmt); 239 kvprintf(fmt, putchar, &pca, 10, ap); 240 va_end(ap); 241 242 msgbuftrigger = 1; 243 } 244 245 #define CONSCHUNK 128 246 247 void 248 log_console(struct uio *uio) 249 { 250 int c, i, error, iovlen, nl; 251 struct uio muio; 252 struct iovec *miov = NULL; 253 char *consbuffer; 254 int pri; 255 256 if (!log_console_output) 257 return; 258 259 pri = LOG_INFO | LOG_CONSOLE; 260 muio = *uio; 261 iovlen = uio->uio_iovcnt * sizeof (struct iovec); 262 MALLOC(miov, struct iovec *, iovlen, M_TEMP, M_WAITOK); 263 MALLOC(consbuffer, char *, CONSCHUNK, M_TEMP, M_WAITOK); 264 bcopy(muio.uio_iov, miov, iovlen); 265 muio.uio_iov = miov; 266 uio = &muio; 267 268 nl = 0; 269 while (uio->uio_resid > 0) { 270 c = imin(uio->uio_resid, CONSCHUNK); 271 error = uiomove(consbuffer, c, uio); 272 if (error != 0) 273 break; 274 for (i = 0; i < c; i++) { 275 msglogchar(consbuffer[i], pri); 276 if (consbuffer[i] == '\n') 277 nl = 1; 278 else 279 nl = 0; 280 } 281 } 282 if (!nl) 283 msglogchar('\n', pri); 284 msgbuftrigger = 1; 285 FREE(miov, M_TEMP); 286 FREE(consbuffer, M_TEMP); 287 return; 288 } 289 290 int 291 printf(const char *fmt, ...) 292 { 293 va_list ap; 294 int savintr; 295 struct putchar_arg pca; 296 int retval; 297 298 savintr = consintr; /* disable interrupts */ 299 consintr = 0; 300 va_start(ap, fmt); 301 pca.tty = NULL; 302 pca.flags = TOCONS | TOLOG; 303 pca.pri = -1; 304 retval = kvprintf(fmt, putchar, &pca, 10, ap); 305 va_end(ap); 306 if (!panicstr) 307 msgbuftrigger = 1; 308 consintr = savintr; /* reenable interrupts */ 309 return (retval); 310 } 311 312 int 313 vprintf(const char *fmt, va_list ap) 314 { 315 int savintr; 316 struct putchar_arg pca; 317 int retval; 318 319 savintr = consintr; /* disable interrupts */ 320 consintr = 0; 321 pca.tty = NULL; 322 pca.flags = TOCONS | TOLOG; 323 pca.pri = -1; 324 retval = kvprintf(fmt, putchar, &pca, 10, ap); 325 if (!panicstr) 326 msgbuftrigger = 1; 327 consintr = savintr; /* reenable interrupts */ 328 return (retval); 329 } 330 331 /* 332 * Print a character on console or users terminal. If destination is 333 * the console then the last bunch of characters are saved in msgbuf for 334 * inspection later. 335 */ 336 static void 337 putchar(int c, void *arg) 338 { 339 struct putchar_arg *ap = (struct putchar_arg*) arg; 340 int flags = ap->flags; 341 struct tty *tp = ap->tty; 342 if (panicstr) 343 constty = NULL; 344 if ((flags & TOCONS) && tp == NULL && constty) { 345 tp = constty; 346 flags |= TOTTY; 347 } 348 if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 && 349 (flags & TOCONS) && tp == constty) 350 constty = NULL; 351 if ((flags & TOLOG)) 352 msglogchar(c, ap->pri); 353 if ((flags & TOCONS) && constty == NULL && c != '\0') 354 (*v_putc)(c); 355 } 356 357 /* 358 * Scaled down version of sprintf(3). 359 */ 360 int 361 sprintf(char *buf, const char *cfmt, ...) 362 { 363 int retval; 364 va_list ap; 365 366 va_start(ap, cfmt); 367 retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap); 368 buf[retval] = '\0'; 369 va_end(ap); 370 return (retval); 371 } 372 373 /* 374 * Scaled down version of vsprintf(3). 375 */ 376 int 377 vsprintf(char *buf, const char *cfmt, va_list ap) 378 { 379 int retval; 380 381 retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap); 382 buf[retval] = '\0'; 383 return (retval); 384 } 385 386 /* 387 * Scaled down version of snprintf(3). 388 */ 389 int 390 snprintf(char *str, size_t size, const char *format, ...) 391 { 392 int retval; 393 va_list ap; 394 395 va_start(ap, format); 396 retval = vsnprintf(str, size, format, ap); 397 va_end(ap); 398 return(retval); 399 } 400 401 /* 402 * Scaled down version of vsnprintf(3). 403 */ 404 int 405 vsnprintf(char *str, size_t size, const char *format, va_list ap) 406 { 407 struct snprintf_arg info; 408 int retval; 409 410 info.str = str; 411 info.remain = size; 412 retval = kvprintf(format, snprintf_func, &info, 10, ap); 413 if (info.remain >= 1) 414 *info.str++ = '\0'; 415 return (retval); 416 } 417 418 /* 419 * Kernel version which takes radix argument vsnprintf(3). 420 */ 421 int 422 vsnrprintf(char *str, size_t size, int radix, const char *format, va_list ap) 423 { 424 struct snprintf_arg info; 425 int retval; 426 427 info.str = str; 428 info.remain = size; 429 retval = kvprintf(format, snprintf_func, &info, radix, ap); 430 if (info.remain >= 1) 431 *info.str++ = '\0'; 432 return (retval); 433 } 434 435 static void 436 snprintf_func(int ch, void *arg) 437 { 438 struct snprintf_arg *const info = arg; 439 440 if (info->remain >= 2) { 441 *info->str++ = ch; 442 info->remain--; 443 } 444 } 445 446 /* 447 * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse 448 * order; return an optional length and a pointer to the last character 449 * written in the buffer (i.e., the first character of the string). 450 * The buffer pointed to by `nbuf' must have length >= MAXNBUF. 451 */ 452 static char * 453 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp) 454 { 455 char *p; 456 457 p = nbuf; 458 *p = '\0'; 459 do { 460 *++p = hex2ascii(num % base); 461 } while (num /= base); 462 if (lenp) 463 *lenp = p - nbuf; 464 return (p); 465 } 466 467 /* 468 * Scaled down version of printf(3). 469 * 470 * Two additional formats: 471 * 472 * The format %b is supported to decode error registers. 473 * Its usage is: 474 * 475 * printf("reg=%b\n", regval, "<base><arg>*"); 476 * 477 * where <base> is the output base expressed as a control character, e.g. 478 * \10 gives octal; \20 gives hex. Each arg is a sequence of characters, 479 * the first of which gives the bit number to be inspected (origin 1), and 480 * the next characters (up to a control character, i.e. a character <= 32), 481 * give the name of the register. Thus: 482 * 483 * kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n"); 484 * 485 * would produce output: 486 * 487 * reg=3<BITTWO,BITONE> 488 * 489 * XXX: %D -- Hexdump, takes pointer and separator string: 490 * ("%6D", ptr, ":") -> XX:XX:XX:XX:XX:XX 491 * ("%*D", len, ptr, " " -> XX XX XX XX ... 492 */ 493 int 494 kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap) 495 { 496 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; } 497 char nbuf[MAXNBUF]; 498 char *d; 499 const char *p, *percent, *q; 500 u_char *up; 501 int ch, n; 502 uintmax_t num; 503 int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot; 504 int jflag, tflag, zflag; 505 int dwidth; 506 char padc; 507 int retval = 0; 508 509 num = 0; 510 if (!func) 511 d = (char *) arg; 512 else 513 d = NULL; 514 515 if (fmt == NULL) 516 fmt = "(fmt null)\n"; 517 518 if (radix < 2 || radix > 36) 519 radix = 10; 520 521 for (;;) { 522 padc = ' '; 523 width = 0; 524 while ((ch = (u_char)*fmt++) != '%') { 525 if (ch == '\0') 526 return (retval); 527 PCHAR(ch); 528 } 529 percent = fmt - 1; 530 qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0; 531 sign = 0; dot = 0; dwidth = 0; 532 jflag = 0; tflag = 0; zflag = 0; 533 reswitch: switch (ch = (u_char)*fmt++) { 534 case '.': 535 dot = 1; 536 goto reswitch; 537 case '#': 538 sharpflag = 1; 539 goto reswitch; 540 case '+': 541 sign = 1; 542 goto reswitch; 543 case '-': 544 ladjust = 1; 545 goto reswitch; 546 case '%': 547 PCHAR(ch); 548 break; 549 case '*': 550 if (!dot) { 551 width = va_arg(ap, int); 552 if (width < 0) { 553 ladjust = !ladjust; 554 width = -width; 555 } 556 } else { 557 dwidth = va_arg(ap, int); 558 } 559 goto reswitch; 560 case '0': 561 if (!dot) { 562 padc = '0'; 563 goto reswitch; 564 } 565 case '1': case '2': case '3': case '4': 566 case '5': case '6': case '7': case '8': case '9': 567 for (n = 0;; ++fmt) { 568 n = n * 10 + ch - '0'; 569 ch = *fmt; 570 if (ch < '0' || ch > '9') 571 break; 572 } 573 if (dot) 574 dwidth = n; 575 else 576 width = n; 577 goto reswitch; 578 case 'b': 579 num = (u_int)va_arg(ap, int); 580 p = va_arg(ap, char *); 581 for (q = ksprintn(nbuf, num, *p++, NULL); *q;) 582 PCHAR(*q--); 583 584 if (num == 0) 585 break; 586 587 for (tmp = 0; *p;) { 588 n = *p++; 589 if (num & (1 << (n - 1))) { 590 PCHAR(tmp ? ',' : '<'); 591 for (; (n = *p) > ' '; ++p) 592 PCHAR(n); 593 tmp = 1; 594 } else 595 for (; *p > ' '; ++p) 596 continue; 597 } 598 if (tmp) 599 PCHAR('>'); 600 break; 601 case 'c': 602 PCHAR(va_arg(ap, int)); 603 break; 604 case 'D': 605 up = va_arg(ap, u_char *); 606 p = va_arg(ap, char *); 607 if (!width) 608 width = 16; 609 while(width--) { 610 PCHAR(hex2ascii(*up >> 4)); 611 PCHAR(hex2ascii(*up & 0x0f)); 612 up++; 613 if (width) 614 for (q=p;*q;q++) 615 PCHAR(*q); 616 } 617 break; 618 case 'd': 619 case 'i': 620 base = 10; 621 sign = 1; 622 goto handle_sign; 623 case 'j': 624 jflag = 1; 625 goto reswitch; 626 case 'l': 627 if (lflag) { 628 lflag = 0; 629 qflag = 1; 630 } else 631 lflag = 1; 632 goto reswitch; 633 case 'n': 634 if (jflag) 635 *(va_arg(ap, intmax_t *)) = retval; 636 else if (qflag) 637 *(va_arg(ap, quad_t *)) = retval; 638 else if (lflag) 639 *(va_arg(ap, long *)) = retval; 640 else if (zflag) 641 *(va_arg(ap, size_t *)) = retval; 642 else 643 *(va_arg(ap, int *)) = retval; 644 break; 645 case 'o': 646 base = 8; 647 goto handle_nosign; 648 case 'p': 649 base = 16; 650 sharpflag = (width == 0); 651 sign = 0; 652 num = (uintptr_t)va_arg(ap, void *); 653 goto number; 654 case 'q': 655 qflag = 1; 656 goto reswitch; 657 case 'r': 658 base = radix; 659 if (sign) 660 goto handle_sign; 661 goto handle_nosign; 662 case 's': 663 p = va_arg(ap, char *); 664 if (p == NULL) 665 p = "(null)"; 666 if (!dot) 667 n = strlen (p); 668 else 669 for (n = 0; n < dwidth && p[n]; n++) 670 continue; 671 672 width -= n; 673 674 if (!ladjust && width > 0) 675 while (width--) 676 PCHAR(padc); 677 while (n--) 678 PCHAR(*p++); 679 if (ladjust && width > 0) 680 while (width--) 681 PCHAR(padc); 682 break; 683 case 't': 684 tflag = 1; 685 goto reswitch; 686 case 'u': 687 base = 10; 688 goto handle_nosign; 689 case 'x': 690 case 'X': 691 base = 16; 692 goto handle_nosign; 693 case 'y': 694 base = 16; 695 sign = 1; 696 goto handle_sign; 697 case 'z': 698 zflag = 1; 699 goto reswitch; 700 handle_nosign: 701 sign = 0; 702 if (jflag) 703 num = va_arg(ap, uintmax_t); 704 else if (qflag) 705 num = va_arg(ap, u_quad_t); 706 else if (tflag) 707 num = va_arg(ap, ptrdiff_t); 708 else if (lflag) 709 num = va_arg(ap, u_long); 710 else if (zflag) 711 num = va_arg(ap, size_t); 712 else 713 num = va_arg(ap, u_int); 714 goto number; 715 handle_sign: 716 if (jflag) 717 num = va_arg(ap, intmax_t); 718 else if (qflag) 719 num = va_arg(ap, quad_t); 720 else if (tflag) 721 num = va_arg(ap, ptrdiff_t); 722 else if (lflag) 723 num = va_arg(ap, long); 724 else if (zflag) 725 num = va_arg(ap, size_t); 726 else 727 num = va_arg(ap, int); 728 number: 729 if (sign && (intmax_t)num < 0) { 730 neg = 1; 731 num = -(intmax_t)num; 732 } 733 p = ksprintn(nbuf, num, base, &tmp); 734 if (sharpflag && num != 0) { 735 if (base == 8) 736 tmp++; 737 else if (base == 16) 738 tmp += 2; 739 } 740 if (neg) 741 tmp++; 742 743 if (!ladjust && width && (width -= tmp) > 0) 744 while (width--) 745 PCHAR(padc); 746 if (neg) 747 PCHAR('-'); 748 if (sharpflag && num != 0) { 749 if (base == 8) { 750 PCHAR('0'); 751 } else if (base == 16) { 752 PCHAR('0'); 753 PCHAR('x'); 754 } 755 } 756 757 while (*p) 758 PCHAR(*p--); 759 760 if (ladjust && width && (width -= tmp) > 0) 761 while (width--) 762 PCHAR(padc); 763 764 break; 765 default: 766 while (percent < fmt) 767 PCHAR(*percent++); 768 break; 769 } 770 } 771 #undef PCHAR 772 } 773 774 /* 775 * Put character in log buffer with a particular priority. 776 */ 777 static void 778 msglogchar(int c, int pri) 779 { 780 static int lastpri = -1; 781 static int dangling; 782 char nbuf[MAXNBUF]; 783 char *p; 784 785 if (!msgbufmapped) 786 return; 787 if (c == '\0' || c == '\r') 788 return; 789 if (pri != -1 && pri != lastpri) { 790 if (dangling) { 791 msgaddchar('\n', NULL); 792 dangling = 0; 793 } 794 msgaddchar('<', NULL); 795 for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL); *p;) 796 msgaddchar(*p--, NULL); 797 msgaddchar('>', NULL); 798 lastpri = pri; 799 } 800 msgaddchar(c, NULL); 801 if (c == '\n') { 802 dangling = 0; 803 lastpri = -1; 804 } else { 805 dangling = 1; 806 } 807 } 808 809 /* 810 * Put char in log buffer 811 */ 812 static void 813 msgaddchar(int c, void *dummy) 814 { 815 struct msgbuf *mbp; 816 817 if (!msgbufmapped) 818 return; 819 mbp = msgbufp; 820 mbp->msg_cksum += (u_char)c - (u_char)mbp->msg_ptr[mbp->msg_bufx]; 821 mbp->msg_ptr[mbp->msg_bufx++] = c; 822 if (mbp->msg_bufx >= mbp->msg_size) 823 mbp->msg_bufx = 0; 824 /* If the buffer is full, keep the most recent data. */ 825 if (mbp->msg_bufr == mbp->msg_bufx) { 826 if (++mbp->msg_bufr >= mbp->msg_size) 827 mbp->msg_bufr = 0; 828 } 829 } 830 831 static void 832 msgbufcopy(struct msgbuf *oldp) 833 { 834 int pos; 835 836 pos = oldp->msg_bufr; 837 while (pos != oldp->msg_bufx) { 838 msglogchar(oldp->msg_ptr[pos], -1); 839 if (++pos >= oldp->msg_size) 840 pos = 0; 841 } 842 } 843 844 void 845 msgbufinit(void *ptr, int size) 846 { 847 char *cp; 848 static struct msgbuf *oldp = NULL; 849 850 size -= sizeof(*msgbufp); 851 cp = (char *)ptr; 852 msgbufp = (struct msgbuf *) (cp + size); 853 if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size || 854 msgbufp->msg_bufx >= size || msgbufp->msg_bufx < 0 || 855 msgbufp->msg_bufr >= size || msgbufp->msg_bufr < 0 || 856 msgbufcksum(cp, size, msgbufp->msg_cksum) != msgbufp->msg_cksum) { 857 bzero(cp, size); 858 bzero(msgbufp, sizeof(*msgbufp)); 859 msgbufp->msg_magic = MSG_MAGIC; 860 msgbufp->msg_size = size; 861 } 862 msgbufp->msg_ptr = cp; 863 if (msgbufmapped && oldp != msgbufp) 864 msgbufcopy(oldp); 865 msgbufmapped = 1; 866 oldp = msgbufp; 867 } 868 869 static u_int 870 msgbufcksum(char *cp, size_t size, u_int cksum) 871 { 872 u_int sum; 873 int i; 874 875 sum = 0; 876 for (i = 0; i < size; i++) 877 sum += (u_char)cp[i]; 878 if (sum != cksum) 879 printf("msgbuf cksum mismatch (read %x, calc %x)\n", cksum, 880 sum); 881 882 return (sum); 883 } 884 885 SYSCTL_DECL(_security_bsd); 886 887 static int unprivileged_read_msgbuf = 1; 888 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_read_msgbuf, 889 CTLFLAG_RW, &unprivileged_read_msgbuf, 0, 890 "Unprivileged processes may read the kernel message buffer"); 891 892 /* Sysctls for accessing/clearing the msgbuf */ 893 static int 894 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS) 895 { 896 int error; 897 898 if (!unprivileged_read_msgbuf) { 899 error = suser(req->td); 900 if (error) 901 return (error); 902 } 903 904 /* 905 * Unwind the buffer, so that it's linear (possibly starting with 906 * some initial nulls). 907 */ 908 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr + msgbufp->msg_bufx, 909 msgbufp->msg_size - msgbufp->msg_bufx, req); 910 if (error) 911 return (error); 912 if (msgbufp->msg_bufx > 0) { 913 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr, 914 msgbufp->msg_bufx, req); 915 } 916 return (error); 917 } 918 919 SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD, 920 0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer"); 921 922 static int msgbuf_clear; 923 924 static int 925 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS) 926 { 927 int error; 928 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); 929 if (!error && req->newptr) { 930 /* Clear the buffer and reset write pointer */ 931 bzero(msgbufp->msg_ptr, msgbufp->msg_size); 932 msgbufp->msg_bufr = msgbufp->msg_bufx = 0; 933 msgbufp->msg_cksum = 0; 934 msgbuf_clear = 0; 935 } 936 return (error); 937 } 938 939 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear, 940 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0, 941 sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer"); 942 943 #ifdef DDB 944 945 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf) 946 { 947 int i, j; 948 949 if (!msgbufmapped) { 950 db_printf("msgbuf not mapped yet\n"); 951 return; 952 } 953 db_printf("msgbufp = %p\n", msgbufp); 954 db_printf("magic = %x, size = %d, r= %d, w = %d, ptr = %p, cksum= %d\n", 955 msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_bufr, 956 msgbufp->msg_bufx, msgbufp->msg_ptr, msgbufp->msg_cksum); 957 for (i = 0; i < msgbufp->msg_size; i++) { 958 j = (i + msgbufp->msg_bufr) % msgbufp->msg_size; 959 db_printf("%c", msgbufp->msg_ptr[j]); 960 } 961 db_printf("\n"); 962 } 963 964 #endif /* DDB */ 965