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: src/sys/kern/subr_prf.c,v 1.61.2.5 2002/08/31 18:22:08 dwmalone Exp $ 40 * $DragonFly: src/sys/kern/subr_prf.c,v 1.20 2008/01/04 12:16:19 matthias Exp $ 41 */ 42 43 #include "opt_ddb.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/kernel.h> 48 #include <sys/msgbuf.h> 49 #include <sys/malloc.h> 50 #include <sys/proc.h> 51 #include <sys/tty.h> 52 #include <sys/tprintf.h> 53 #include <sys/stdint.h> 54 #include <sys/syslog.h> 55 #include <sys/cons.h> 56 #include <sys/uio.h> 57 #include <sys/sysctl.h> 58 #include <sys/lock.h> 59 #include <sys/ctype.h> 60 61 #ifdef DDB 62 #include <ddb/ddb.h> 63 #endif 64 65 /* 66 * Note that stdarg.h and the ANSI style va_start macro is used for both 67 * ANSI and traditional C compilers. We use the __ machine version to stay 68 * within the kernel header file set. 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 void kputchar (int ch, void *arg); 98 static char *ksprintn (char *nbuf, uintmax_t num, int base, int *lenp, 99 int upper); 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 static int unprivileged_read_msgbuf = 1; 112 SYSCTL_INT(_security, OID_AUTO, unprivileged_read_msgbuf, CTLFLAG_RW, 113 &unprivileged_read_msgbuf, 0, 114 "Unprivileged processes may read the kernel message buffer"); 115 116 /* 117 * Warn that a system table is full. 118 */ 119 void 120 tablefull(const char *tab) 121 { 122 123 log(LOG_ERR, "%s: table is full\n", tab); 124 } 125 126 /* 127 * Uprintf prints to the controlling terminal for the current process. 128 */ 129 int 130 uprintf(const char *fmt, ...) 131 { 132 struct proc *p = curproc; 133 __va_list ap; 134 struct putchar_arg pca; 135 int retval = 0; 136 137 if (p && p->p_flag & P_CONTROLT && 138 p->p_session->s_ttyvp) { 139 __va_start(ap, fmt); 140 pca.tty = p->p_session->s_ttyp; 141 pca.flags = TOTTY; 142 143 retval = kvcprintf(fmt, kputchar, &pca, 10, ap); 144 __va_end(ap); 145 } 146 return (retval); 147 } 148 149 tpr_t 150 tprintf_open(struct proc *p) 151 { 152 153 if ((p->p_flag & P_CONTROLT) && p->p_session->s_ttyvp) { 154 sess_hold(p->p_session); 155 return ((tpr_t) p->p_session); 156 } 157 return ((tpr_t) NULL); 158 } 159 160 void 161 tprintf_close(tpr_t sess) 162 { 163 if (sess) 164 sess_rele((struct session *) sess); 165 } 166 167 /* 168 * tprintf prints on the controlling terminal associated 169 * with the given session. 170 */ 171 int 172 tprintf(tpr_t tpr, const char *fmt, ...) 173 { 174 struct session *sess = (struct session *)tpr; 175 struct tty *tp = NULL; 176 int flags = TOLOG; 177 __va_list ap; 178 struct putchar_arg pca; 179 int retval; 180 181 if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) { 182 flags |= TOTTY; 183 tp = sess->s_ttyp; 184 } 185 __va_start(ap, fmt); 186 pca.tty = tp; 187 pca.flags = flags; 188 pca.pri = LOG_INFO; 189 retval = kvcprintf(fmt, kputchar, &pca, 10, ap); 190 __va_end(ap); 191 msgbuftrigger = 1; 192 return (retval); 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 = kvcprintf(fmt, kputchar, &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 int 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 = kvcprintf(fmt, kputchar, &pca, 10, ap); 233 __va_end(ap); 234 235 msgbuftrigger = 1; 236 return (retval); 237 } 238 239 #define CONSCHUNK 128 240 241 void 242 log_console(struct uio *uio) 243 { 244 int c, i, error, iovlen, nl; 245 struct uio muio; 246 struct iovec *miov = NULL; 247 char *consbuffer; 248 int pri; 249 250 if (!log_console_output) 251 return; 252 253 pri = LOG_INFO | LOG_CONSOLE; 254 muio = *uio; 255 iovlen = uio->uio_iovcnt * sizeof (struct iovec); 256 MALLOC(miov, struct iovec *, iovlen, M_TEMP, M_WAITOK); 257 MALLOC(consbuffer, char *, CONSCHUNK, M_TEMP, M_WAITOK); 258 bcopy((caddr_t)muio.uio_iov, (caddr_t)miov, iovlen); 259 muio.uio_iov = miov; 260 uio = &muio; 261 262 nl = 0; 263 while (uio->uio_resid > 0) { 264 c = imin(uio->uio_resid, CONSCHUNK); 265 error = uiomove(consbuffer, c, uio); 266 if (error != 0) 267 break; 268 for (i = 0; i < c; i++) { 269 msglogchar(consbuffer[i], pri); 270 if (consbuffer[i] == '\n') 271 nl = 1; 272 else 273 nl = 0; 274 } 275 } 276 if (!nl) 277 msglogchar('\n', pri); 278 msgbuftrigger = 1; 279 FREE(miov, M_TEMP); 280 FREE(consbuffer, M_TEMP); 281 return; 282 } 283 284 /* 285 * Output to the console. 286 * 287 * NOT YET ENTIRELY MPSAFE 288 */ 289 int 290 kprintf(const char *fmt, ...) 291 { 292 __va_list ap; 293 int savintr; 294 struct putchar_arg pca; 295 int retval; 296 297 savintr = consintr; /* disable interrupts */ 298 consintr = 0; 299 __va_start(ap, fmt); 300 pca.tty = NULL; 301 pca.flags = TOCONS | TOLOG; 302 pca.pri = -1; 303 cons_lock(); 304 retval = kvcprintf(fmt, kputchar, &pca, 10, ap); 305 cons_unlock(); 306 __va_end(ap); 307 if (!panicstr) 308 msgbuftrigger = 1; 309 consintr = savintr; /* reenable interrupts */ 310 return (retval); 311 } 312 313 int 314 kvprintf(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 cons_lock(); 326 retval = kvcprintf(fmt, kputchar, &pca, 10, ap); 327 cons_unlock(); 328 if (!panicstr) 329 msgbuftrigger = 1; 330 consintr = savintr; /* reenable interrupts */ 331 return (retval); 332 } 333 334 /* 335 * Limited rate kprintf. The passed rate structure must be initialized 336 * with the desired reporting frequency. A frequency of 0 will result in 337 * no output. 338 */ 339 void 340 krateprintf(struct krate *rate, const char *fmt, ...) 341 { 342 __va_list ap; 343 344 if (rate->ticks != (int)time_second) { 345 rate->ticks = (int)time_second; 346 rate->count = 0; 347 } 348 if (rate->count < rate->freq) { 349 ++rate->count; 350 __va_start(ap, fmt); 351 kvprintf(fmt, ap); 352 __va_end(ap); 353 } 354 } 355 356 /* 357 * Print a character on console or users terminal. If destination is 358 * the console then the last bunch of characters are saved in msgbuf for 359 * inspection later. 360 * 361 * NOT YET ENTIRELY MPSAFE, EVEN WHEN LOGGING JUST TO THE SYSCONSOLE. 362 */ 363 static void 364 kputchar(int c, void *arg) 365 { 366 struct putchar_arg *ap = (struct putchar_arg*) arg; 367 int flags = ap->flags; 368 struct tty *tp = ap->tty; 369 if (panicstr) 370 constty = NULL; 371 if ((flags & TOCONS) && tp == NULL && constty) { 372 tp = constty; 373 flags |= TOTTY; 374 } 375 if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 && 376 (flags & TOCONS) && tp == constty) 377 constty = NULL; 378 if ((flags & TOLOG)) 379 msglogchar(c, ap->pri); 380 if ((flags & TOCONS) && constty == NULL && c != '\0') 381 (*v_putc)(c); 382 } 383 384 /* 385 * Scaled down version of sprintf(3). 386 */ 387 int 388 ksprintf(char *buf, const char *cfmt, ...) 389 { 390 int retval; 391 __va_list ap; 392 393 __va_start(ap, cfmt); 394 retval = kvcprintf(cfmt, NULL, (void *)buf, 10, ap); 395 buf[retval] = '\0'; 396 __va_end(ap); 397 return (retval); 398 } 399 400 /* 401 * Scaled down version of vsprintf(3). 402 */ 403 int 404 kvsprintf(char *buf, const char *cfmt, __va_list ap) 405 { 406 int retval; 407 408 retval = kvcprintf(cfmt, NULL, (void *)buf, 10, ap); 409 buf[retval] = '\0'; 410 return (retval); 411 } 412 413 /* 414 * Scaled down version of snprintf(3). 415 */ 416 int 417 ksnprintf(char *str, size_t size, const char *format, ...) 418 { 419 int retval; 420 __va_list ap; 421 422 __va_start(ap, format); 423 retval = kvsnprintf(str, size, format, ap); 424 __va_end(ap); 425 return(retval); 426 } 427 428 /* 429 * Scaled down version of vsnprintf(3). 430 */ 431 int 432 kvsnprintf(char *str, size_t size, const char *format, __va_list ap) 433 { 434 struct snprintf_arg info; 435 int retval; 436 437 info.str = str; 438 info.remain = size; 439 retval = kvcprintf(format, snprintf_func, &info, 10, ap); 440 if (info.remain >= 1) 441 *info.str++ = '\0'; 442 return (retval); 443 } 444 445 static void 446 snprintf_func(int ch, void *arg) 447 { 448 struct snprintf_arg *const info = arg; 449 450 if (info->remain >= 2) { 451 *info->str++ = ch; 452 info->remain--; 453 } 454 } 455 456 /* 457 * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse 458 * order; return an optional length and a pointer to the last character 459 * written in the buffer (i.e., the first character of the string). 460 * The buffer pointed to by `nbuf' must have length >= MAXNBUF. 461 */ 462 static char * 463 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper) 464 { 465 char *p, c; 466 467 p = nbuf; 468 *p = '\0'; 469 do { 470 c = hex2ascii(num % base); 471 *++p = upper ? toupper(c) : c; 472 } while (num /= base); 473 if (lenp) 474 *lenp = p - nbuf; 475 return (p); 476 } 477 478 /* 479 * Scaled down version of printf(3). 480 * 481 * Two additional formats: 482 * 483 * The format %b is supported to decode error registers. 484 * Its usage is: 485 * 486 * kprintf("reg=%b\n", regval, "<base><arg>*"); 487 * 488 * where <base> is the output base expressed as a control character, e.g. 489 * \10 gives octal; \20 gives hex. Each arg is a sequence of characters, 490 * the first of which gives the bit number to be inspected (origin 1), and 491 * the next characters (up to a control character, i.e. a character <= 32), 492 * give the name of the register. Thus: 493 * 494 * kvcprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n"); 495 * 496 * would produce output: 497 * 498 * reg=3<BITTWO,BITONE> 499 * 500 * XXX: %D -- Hexdump, takes pointer and separator string: 501 * ("%6D", ptr, ":") -> XX:XX:XX:XX:XX:XX 502 * ("%*D", len, ptr, " " -> XX XX XX XX ... 503 */ 504 int 505 kvcprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, __va_list ap) 506 { 507 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; } 508 char nbuf[MAXNBUF]; 509 char *d; 510 const char *p, *percent, *q; 511 u_char *up; 512 int ch, n; 513 uintmax_t num; 514 int base, tmp, width, ladjust, sharpflag, neg, sign, dot; 515 int jflag, lflag, qflag, tflag; 516 int dwidth, upper; 517 char padc; 518 int retval = 0, stop = 0; 519 520 num = 0; 521 if (!func) 522 d = (char *) arg; 523 else 524 d = NULL; 525 526 if (fmt == NULL) 527 fmt = "(fmt null)\n"; 528 529 if (radix < 2 || radix > 36) 530 radix = 10; 531 532 for (;;) { 533 padc = ' '; 534 width = 0; 535 while ((ch = (u_char)*fmt++) != '%' || stop) { 536 if (ch == '\0') 537 return (retval); 538 PCHAR(ch); 539 } 540 percent = fmt - 1; 541 dot = dwidth = ladjust = neg = sharpflag = sign = upper = 0; 542 jflag = lflag = qflag = tflag = 0; 543 544 reswitch: 545 switch (ch = (u_char)*fmt++) { 546 case '.': 547 dot = 1; 548 goto reswitch; 549 case '#': 550 sharpflag = 1; 551 goto reswitch; 552 case '+': 553 sign = 1; 554 goto reswitch; 555 case '-': 556 ladjust = 1; 557 goto reswitch; 558 case '%': 559 PCHAR(ch); 560 break; 561 case '*': 562 if (!dot) { 563 width = __va_arg(ap, int); 564 if (width < 0) { 565 ladjust = !ladjust; 566 width = -width; 567 } 568 } else { 569 dwidth = __va_arg(ap, int); 570 } 571 goto reswitch; 572 case '0': 573 if (!dot) { 574 padc = '0'; 575 goto reswitch; 576 } 577 case '1': case '2': case '3': case '4': 578 case '5': case '6': case '7': case '8': case '9': 579 for (n = 0;; ++fmt) { 580 n = n * 10 + ch - '0'; 581 ch = *fmt; 582 if (ch < '0' || ch > '9') 583 break; 584 } 585 if (dot) 586 dwidth = n; 587 else 588 width = n; 589 goto reswitch; 590 case 'b': 591 num = (u_int)__va_arg(ap, int); 592 p = __va_arg(ap, char *); 593 for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;) 594 PCHAR(*q--); 595 596 if (num == 0) 597 break; 598 599 for (tmp = 0; *p;) { 600 n = *p++; 601 if (num & (1 << (n - 1))) { 602 PCHAR(tmp ? ',' : '<'); 603 for (; (n = *p) > ' '; ++p) 604 PCHAR(n); 605 tmp = 1; 606 } else 607 for (; *p > ' '; ++p) 608 continue; 609 } 610 if (tmp) 611 PCHAR('>'); 612 break; 613 case 'c': 614 PCHAR(__va_arg(ap, int)); 615 break; 616 case 'D': 617 up = __va_arg(ap, u_char *); 618 p = __va_arg(ap, char *); 619 if (!width) 620 width = 16; 621 while(width--) { 622 PCHAR(hex2ascii(*up >> 4)); 623 PCHAR(hex2ascii(*up & 0x0f)); 624 up++; 625 if (width) 626 for (q=p;*q;q++) 627 PCHAR(*q); 628 } 629 break; 630 case 'd': 631 case 'i': 632 base = 10; 633 sign = 1; 634 goto handle_sign; 635 case 'j': 636 jflag = 1; 637 goto reswitch; 638 case 'l': 639 if (lflag) { 640 lflag = 0; 641 qflag = 1; 642 } else 643 lflag = 1; 644 goto reswitch; 645 case 'n': 646 if (jflag) 647 *(__va_arg(ap, intmax_t *)) = retval; 648 else if (lflag) 649 *(__va_arg(ap, long *)) = retval; 650 else if (qflag) 651 *(__va_arg(ap, quad_t *)) = retval; 652 else 653 *(__va_arg(ap, int *)) = retval; 654 break; 655 case 'o': 656 base = 8; 657 goto handle_nosign; 658 case 'p': 659 base = 16; 660 sharpflag = (width == 0); 661 sign = 0; 662 num = (uintptr_t)__va_arg(ap, void *); 663 goto number; 664 case 'q': 665 qflag = 1; 666 goto reswitch; 667 case 'r': 668 base = radix; 669 if (sign) 670 goto handle_sign; 671 goto handle_nosign; 672 case 's': 673 p = __va_arg(ap, char *); 674 if (p == NULL) 675 p = "(null)"; 676 if (!dot) 677 n = strlen (p); 678 else 679 for (n = 0; n < dwidth && p[n]; n++) 680 continue; 681 682 width -= n; 683 684 if (!ladjust && width > 0) 685 while (width--) 686 PCHAR(padc); 687 while (n--) 688 PCHAR(*p++); 689 if (ladjust && width > 0) 690 while (width--) 691 PCHAR(padc); 692 break; 693 case 't': 694 tflag = 1; 695 goto reswitch; 696 case 'u': 697 base = 10; 698 goto handle_nosign; 699 case 'X': 700 upper = 1; 701 /* FALLTHROUGH */ 702 case 'x': 703 base = 16; 704 goto handle_nosign; 705 case 'z': 706 base = 16; 707 sign = 1; 708 goto handle_sign; 709 handle_nosign: 710 sign = 0; 711 if (jflag) 712 num = __va_arg(ap, uintmax_t); 713 else if (lflag) 714 num = __va_arg(ap, u_long); 715 else if (qflag) 716 num = __va_arg(ap, u_quad_t); 717 else if (tflag) 718 num = __va_arg(ap, ptrdiff_t); 719 else 720 num = __va_arg(ap, u_int); 721 goto number; 722 handle_sign: 723 if (jflag) 724 num = __va_arg(ap, intmax_t); 725 else if (lflag) 726 num = __va_arg(ap, long); 727 else if (qflag) 728 num = __va_arg(ap, quad_t); 729 else if (tflag) 730 num = __va_arg(ap, ptrdiff_t); 731 else 732 num = __va_arg(ap, int); 733 number: 734 if (sign && (intmax_t)num < 0) { 735 neg = 1; 736 num = -(intmax_t)num; 737 } 738 p = ksprintn(nbuf, num, base, &tmp, upper); 739 if (sharpflag && num != 0) { 740 if (base == 8) 741 tmp++; 742 else if (base == 16) 743 tmp += 2; 744 } 745 if (neg) 746 tmp++; 747 748 if (!ladjust && padc != '0' && width && 749 (width -= tmp) > 0) { 750 while (width--) 751 PCHAR(padc); 752 } 753 if (neg) 754 PCHAR('-'); 755 if (sharpflag && num != 0) { 756 if (base == 8) { 757 PCHAR('0'); 758 } else if (base == 16) { 759 PCHAR('0'); 760 PCHAR('x'); 761 } 762 } 763 if (!ladjust && width && (width -= tmp) > 0) 764 while (width--) 765 PCHAR(padc); 766 767 while (*p) 768 PCHAR(*p--); 769 770 if (ladjust && width && (width -= tmp) > 0) 771 while (width--) 772 PCHAR(padc); 773 774 break; 775 default: 776 while (percent < fmt) 777 PCHAR(*percent++); 778 /* 779 * Since we ignore an formatting argument it is no 780 * longer safe to obey the remaining formatting 781 * arguments as the arguments will no longer match 782 * the format specs. 783 */ 784 stop = 1; 785 break; 786 } 787 } 788 #undef PCHAR 789 } 790 791 /* 792 * Put character in log buffer with a particular priority. 793 * 794 * MPSAFE 795 */ 796 static void 797 msglogchar(int c, int pri) 798 { 799 static int lastpri = -1; 800 static int dangling; 801 char nbuf[MAXNBUF]; 802 char *p; 803 804 if (!msgbufmapped) 805 return; 806 if (c == '\0' || c == '\r') 807 return; 808 if (pri != -1 && pri != lastpri) { 809 if (dangling) { 810 msgaddchar('\n', NULL); 811 dangling = 0; 812 } 813 msgaddchar('<', NULL); 814 for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL, 0); *p;) 815 msgaddchar(*p--, NULL); 816 msgaddchar('>', NULL); 817 lastpri = pri; 818 } 819 msgaddchar(c, NULL); 820 if (c == '\n') { 821 dangling = 0; 822 lastpri = -1; 823 } else { 824 dangling = 1; 825 } 826 } 827 828 /* 829 * Put char in log buffer. Make sure nothing blows up beyond repair if 830 * we have an MP race. 831 * 832 * MPSAFE. 833 */ 834 static void 835 msgaddchar(int c, void *dummy) 836 { 837 struct msgbuf *mbp; 838 int rindex; 839 int windex; 840 841 if (!msgbufmapped) 842 return; 843 mbp = msgbufp; 844 windex = mbp->msg_bufx; 845 mbp->msg_ptr[windex] = c; 846 if (++windex >= mbp->msg_size) 847 windex = 0; 848 rindex = mbp->msg_bufr; 849 if (windex == rindex) { 850 rindex += 32; 851 if (rindex >= mbp->msg_size) 852 rindex -= mbp->msg_size; 853 mbp->msg_bufr = rindex; 854 } 855 mbp->msg_bufx = windex; 856 } 857 858 static void 859 msgbufcopy(struct msgbuf *oldp) 860 { 861 int pos; 862 863 pos = oldp->msg_bufr; 864 while (pos != oldp->msg_bufx) { 865 msglogchar(oldp->msg_ptr[pos], -1); 866 if (++pos >= oldp->msg_size) 867 pos = 0; 868 } 869 } 870 871 void 872 msgbufinit(void *ptr, size_t size) 873 { 874 char *cp; 875 static struct msgbuf *oldp = NULL; 876 877 size -= sizeof(*msgbufp); 878 cp = (char *)ptr; 879 msgbufp = (struct msgbuf *) (cp + size); 880 if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size || 881 msgbufp->msg_bufx >= size || msgbufp->msg_bufr >= size) { 882 bzero(cp, size); 883 bzero(msgbufp, sizeof(*msgbufp)); 884 msgbufp->msg_magic = MSG_MAGIC; 885 msgbufp->msg_size = (char *)msgbufp - cp; 886 } 887 msgbufp->msg_ptr = cp; 888 if (msgbufmapped && oldp != msgbufp) 889 msgbufcopy(oldp); 890 msgbufmapped = 1; 891 oldp = msgbufp; 892 } 893 894 /* Sysctls for accessing/clearing the msgbuf */ 895 896 static int 897 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS) 898 { 899 struct ucred *cred; 900 int error; 901 902 /* 903 * Only wheel or root can access the message log. 904 */ 905 if (unprivileged_read_msgbuf == 0) { 906 KKASSERT(req->td->td_proc); 907 cred = req->td->td_proc->p_ucred; 908 909 if ((cred->cr_prison || groupmember(0, cred) == 0) && 910 suser(req->td) != 0 911 ) { 912 return (EPERM); 913 } 914 } 915 916 /* 917 * Unwind the buffer, so that it's linear (possibly starting with 918 * some initial nulls). 919 */ 920 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr + msgbufp->msg_bufx, 921 msgbufp->msg_size - msgbufp->msg_bufx, req); 922 if (error) 923 return (error); 924 if (msgbufp->msg_bufx > 0) { 925 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr, 926 msgbufp->msg_bufx, req); 927 } 928 return (error); 929 } 930 931 SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD, 932 0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer"); 933 934 static int msgbuf_clear; 935 936 static int 937 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS) 938 { 939 int error; 940 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req); 941 if (!error && req->newptr) { 942 /* Clear the buffer and reset write pointer */ 943 bzero(msgbufp->msg_ptr, msgbufp->msg_size); 944 msgbufp->msg_bufr = msgbufp->msg_bufx = 0; 945 msgbuf_clear = 0; 946 } 947 return (error); 948 } 949 950 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear, 951 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0, 952 sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer"); 953 954 #ifdef DDB 955 956 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf) 957 { 958 int i, j; 959 960 if (!msgbufmapped) { 961 db_printf("msgbuf not mapped yet\n"); 962 return; 963 } 964 db_printf("msgbufp = %p\n", msgbufp); 965 db_printf("magic = %x, size = %d, r= %d, w = %d, ptr = %p\n", 966 msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_bufr, 967 msgbufp->msg_bufx, msgbufp->msg_ptr); 968 for (i = 0; i < msgbufp->msg_size; i++) { 969 j = (i + msgbufp->msg_bufr) % msgbufp->msg_size; 970 db_printf("%c", msgbufp->msg_ptr[j]); 971 } 972 db_printf("\n"); 973 } 974 975 #endif /* DDB */ 976