xref: /freebsd/sys/kern/subr_prf.c (revision d37ea99837e6ad50837fd9fe1771ddf1c3ba6002)
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  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include "opt_ddb.h"
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/lock.h>
45 #include <sys/mutex.h>
46 #include <sys/sx.h>
47 #include <sys/kernel.h>
48 #include <sys/msgbuf.h>
49 #include <sys/malloc.h>
50 #include <sys/proc.h>
51 #include <sys/stddef.h>
52 #include <sys/sysctl.h>
53 #include <sys/tty.h>
54 #include <sys/syslog.h>
55 #include <sys/cons.h>
56 #include <sys/uio.h>
57 
58 #ifdef DDB
59 #include <ddb/ddb.h>
60 #endif
61 
62 /*
63  * Note that stdarg.h and the ANSI style va_start macro is used for both
64  * ANSI and traditional C compilers.
65  */
66 #include <machine/stdarg.h>
67 
68 #define TOCONS	0x01
69 #define TOTTY	0x02
70 #define TOLOG	0x04
71 
72 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
73 #define MAXNBUF	(sizeof(intmax_t) * NBBY + 1)
74 
75 struct putchar_arg {
76 	int	flags;
77 	int	pri;
78 	struct	tty *tty;
79 };
80 
81 struct snprintf_arg {
82 	char	*str;
83 	size_t	remain;
84 };
85 
86 extern	int log_open;
87 
88 static void  msglogchar(int c, int pri);
89 static void  putchar(int ch, void *arg);
90 static char *ksprintn(char *nbuf, uintmax_t num, int base, int *len);
91 static void  snprintf_func(int ch, void *arg);
92 
93 static int consintr = 1;		/* Ok to handle console interrupts? */
94 static int msgbufmapped;		/* Set when safe to use msgbuf */
95 int msgbuftrigger;
96 
97 static int      log_console_output = 1;
98 TUNABLE_INT("kern.log_console_output", &log_console_output);
99 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW,
100     &log_console_output, 0, "Duplicate console output to the syslog.");
101 
102 static int	always_console_output = 0;
103 TUNABLE_INT("kern.always_console_output", &always_console_output);
104 SYSCTL_INT(_kern, OID_AUTO, always_console_output, CTLFLAG_RW,
105     &always_console_output, 0, "Always output to console despite TIOCCONS.");
106 
107 /*
108  * Warn that a system table is full.
109  */
110 void
111 tablefull(const char *tab)
112 {
113 
114 	log(LOG_ERR, "%s: table is full\n", tab);
115 }
116 
117 /*
118  * Uprintf prints to the controlling terminal for the current process.
119  * It may block if the tty queue is overfull.  No message is printed if
120  * the queue does not clear in a reasonable time.
121  */
122 int
123 uprintf(const char *fmt, ...)
124 {
125 	struct thread *td = curthread;
126 	struct proc *p = td->td_proc;
127 	va_list ap;
128 	struct putchar_arg pca;
129 	int retval;
130 
131 	if (td == NULL || td == PCPU_GET(idlethread))
132 		return (0);
133 
134 	p = td->td_proc;
135 	PROC_LOCK(p);
136 	if ((p->p_flag & P_CONTROLT) == 0) {
137 		PROC_UNLOCK(p);
138 		return (0);
139 	}
140 	SESS_LOCK(p->p_session);
141 	pca.tty = p->p_session->s_ttyp;
142 	SESS_UNLOCK(p->p_session);
143 	PROC_UNLOCK(p);
144 	if (pca.tty == NULL)
145 		return (0);
146 	pca.flags = TOTTY;
147 	va_start(ap, fmt);
148 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
149 	va_end(ap);
150 
151 	return (retval);
152 }
153 
154 /*
155  * tprintf prints on the controlling terminal associated
156  * with the given session, possibly to the log as well.
157  */
158 void
159 tprintf(struct proc *p, int pri, const char *fmt, ...)
160 {
161 	struct tty *tp = NULL;
162 	int flags = 0;
163 	va_list ap;
164 	struct putchar_arg pca;
165 	struct session *sess = NULL;
166 
167 	if (pri != -1)
168 		flags |= TOLOG;
169 	if (p != NULL) {
170 		PROC_LOCK(p);
171 		if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
172 			sess = p->p_session;
173 			SESS_LOCK(sess);
174 			PROC_UNLOCK(p);
175 			SESSHOLD(sess);
176 			tp = sess->s_ttyp;
177 			SESS_UNLOCK(sess);
178 			if (ttycheckoutq(tp, 0))
179 				flags |= TOTTY;
180 			else
181 				tp = NULL;
182 		} else
183 			PROC_UNLOCK(p);
184 	}
185 	pca.pri = pri;
186 	pca.tty = tp;
187 	pca.flags = flags;
188 	va_start(ap, fmt);
189 	kvprintf(fmt, putchar, &pca, 10, ap);
190 	va_end(ap);
191 	if (sess != NULL) {
192 		SESS_LOCK(sess);
193 		SESSRELE(sess);
194 		SESS_UNLOCK(sess);
195 	}
196 	msgbuftrigger = 1;
197 }
198 
199 /*
200  * Ttyprintf displays a message on a tty; it should be used only by
201  * the tty driver, or anything that knows the underlying tty will not
202  * be revoke(2)'d away.  Other callers should use tprintf.
203  */
204 int
205 ttyprintf(struct tty *tp, const char *fmt, ...)
206 {
207 	va_list ap;
208 	struct putchar_arg pca;
209 	int retval;
210 
211 	va_start(ap, fmt);
212 	pca.tty = tp;
213 	pca.flags = TOTTY;
214 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
215 	va_end(ap);
216 	return (retval);
217 }
218 
219 /*
220  * Log writes to the log buffer, and guarantees not to sleep (so can be
221  * called by interrupt routines).  If there is no process reading the
222  * log yet, it writes to the console also.
223  */
224 void
225 log(int level, const char *fmt, ...)
226 {
227 	va_list ap;
228 	struct putchar_arg pca;
229 
230 	pca.tty = NULL;
231 	pca.pri = level;
232 	pca.flags = log_open ? TOLOG : TOCONS;
233 
234 	va_start(ap, fmt);
235 	kvprintf(fmt, putchar, &pca, 10, ap);
236 	va_end(ap);
237 
238 	msgbuftrigger = 1;
239 }
240 
241 #define CONSCHUNK 128
242 
243 void
244 log_console(struct uio *uio)
245 {
246 	int c, i, error, iovlen, nl;
247 	struct uio muio;
248 	struct iovec *miov = NULL;
249 	char *consbuffer;
250 	int pri;
251 
252 	if (!log_console_output)
253 		return;
254 
255 	pri = LOG_INFO | LOG_CONSOLE;
256 	muio = *uio;
257 	iovlen = uio->uio_iovcnt * sizeof (struct iovec);
258 	MALLOC(miov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
259 	MALLOC(consbuffer, char *, CONSCHUNK, M_TEMP, M_WAITOK);
260 	bcopy(muio.uio_iov, miov, iovlen);
261 	muio.uio_iov = miov;
262 	uio = &muio;
263 
264 	nl = 0;
265 	while (uio->uio_resid > 0) {
266 		c = imin(uio->uio_resid, CONSCHUNK);
267 		error = uiomove(consbuffer, c, uio);
268 		if (error != 0)
269 			break;
270 		for (i = 0; i < c; i++) {
271 			msglogchar(consbuffer[i], pri);
272 			if (consbuffer[i] == '\n')
273 				nl = 1;
274 			else
275 				nl = 0;
276 		}
277 	}
278 	if (!nl)
279 		msglogchar('\n', pri);
280 	msgbuftrigger = 1;
281 	FREE(miov, M_TEMP);
282 	FREE(consbuffer, M_TEMP);
283 	return;
284 }
285 
286 int
287 printf(const char *fmt, ...)
288 {
289 	va_list ap;
290 	int savintr;
291 	struct putchar_arg pca;
292 	int retval;
293 
294 	savintr = consintr;		/* disable interrupts */
295 	consintr = 0;
296 	va_start(ap, fmt);
297 	pca.tty = NULL;
298 	pca.flags = TOCONS | TOLOG;
299 	pca.pri = -1;
300 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
301 	va_end(ap);
302 	if (!panicstr)
303 		msgbuftrigger = 1;
304 	consintr = savintr;		/* reenable interrupts */
305 	return (retval);
306 }
307 
308 int
309 vprintf(const char *fmt, va_list ap)
310 {
311 	int savintr;
312 	struct putchar_arg pca;
313 	int retval;
314 
315 	savintr = consintr;		/* disable interrupts */
316 	consintr = 0;
317 	pca.tty = NULL;
318 	pca.flags = TOCONS | TOLOG;
319 	pca.pri = -1;
320 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
321 	if (!panicstr)
322 		msgbuftrigger = 1;
323 	consintr = savintr;		/* reenable interrupts */
324 	return (retval);
325 }
326 
327 /*
328  * Print a character on console or users terminal.  If destination is
329  * the console then the last bunch of characters are saved in msgbuf for
330  * inspection later.
331  */
332 static void
333 putchar(int c, void *arg)
334 {
335 	struct putchar_arg *ap = (struct putchar_arg*) arg;
336 	struct tty *tp = ap->tty;
337 	int consdirect, flags = ap->flags;
338 
339 	consdirect = ((flags & TOCONS) && constty == NULL);
340 	/* Don't use the tty code after a panic or while in ddb. */
341 	if (panicstr)
342 		consdirect = 1;
343 #ifdef DDB
344 	if (db_active)
345 		consdirect = 1;
346 #endif
347 	if (consdirect) {
348 		if (c != '\0')
349 			cnputc(c);
350 	} else {
351 		if ((flags & TOTTY) && tp != NULL)
352 			tputchar(c, tp);
353 		if (flags & TOCONS) {
354 			if (constty != NULL)
355 				msgbuf_addchar(&consmsgbuf, c);
356 			if (always_console_output && c != '\0')
357 				cnputc(c);
358 		}
359 	}
360 	if ((flags & TOLOG))
361 		msglogchar(c, ap->pri);
362 }
363 
364 /*
365  * Scaled down version of sprintf(3).
366  */
367 int
368 sprintf(char *buf, const char *cfmt, ...)
369 {
370 	int retval;
371 	va_list ap;
372 
373 	va_start(ap, cfmt);
374 	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
375 	buf[retval] = '\0';
376 	va_end(ap);
377 	return (retval);
378 }
379 
380 /*
381  * Scaled down version of vsprintf(3).
382  */
383 int
384 vsprintf(char *buf, const char *cfmt, va_list ap)
385 {
386 	int retval;
387 
388 	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
389 	buf[retval] = '\0';
390 	return (retval);
391 }
392 
393 /*
394  * Scaled down version of snprintf(3).
395  */
396 int
397 snprintf(char *str, size_t size, const char *format, ...)
398 {
399 	int retval;
400 	va_list ap;
401 
402 	va_start(ap, format);
403 	retval = vsnprintf(str, size, format, ap);
404 	va_end(ap);
405 	return(retval);
406 }
407 
408 /*
409  * Scaled down version of vsnprintf(3).
410  */
411 int
412 vsnprintf(char *str, size_t size, const char *format, va_list ap)
413 {
414 	struct snprintf_arg info;
415 	int retval;
416 
417 	info.str = str;
418 	info.remain = size;
419 	retval = kvprintf(format, snprintf_func, &info, 10, ap);
420 	if (info.remain >= 1)
421 		*info.str++ = '\0';
422 	return (retval);
423 }
424 
425 /*
426  * Kernel version which takes radix argument vsnprintf(3).
427  */
428 int
429 vsnrprintf(char *str, size_t size, int radix, const char *format, va_list ap)
430 {
431 	struct snprintf_arg info;
432 	int retval;
433 
434 	info.str = str;
435 	info.remain = size;
436 	retval = kvprintf(format, snprintf_func, &info, radix, ap);
437 	if (info.remain >= 1)
438 		*info.str++ = '\0';
439 	return (retval);
440 }
441 
442 static void
443 snprintf_func(int ch, void *arg)
444 {
445 	struct snprintf_arg *const info = arg;
446 
447 	if (info->remain >= 2) {
448 		*info->str++ = ch;
449 		info->remain--;
450 	}
451 }
452 
453 /*
454  * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
455  * order; return an optional length and a pointer to the last character
456  * written in the buffer (i.e., the first character of the string).
457  * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
458  */
459 static char *
460 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp)
461 {
462 	char *p;
463 
464 	p = nbuf;
465 	*p = '\0';
466 	do {
467 		*++p = hex2ascii(num % base);
468 	} while (num /= base);
469 	if (lenp)
470 		*lenp = p - nbuf;
471 	return (p);
472 }
473 
474 /*
475  * Scaled down version of printf(3).
476  *
477  * Two additional formats:
478  *
479  * The format %b is supported to decode error registers.
480  * Its usage is:
481  *
482  *	printf("reg=%b\n", regval, "<base><arg>*");
483  *
484  * where <base> is the output base expressed as a control character, e.g.
485  * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
486  * the first of which gives the bit number to be inspected (origin 1), and
487  * the next characters (up to a control character, i.e. a character <= 32),
488  * give the name of the register.  Thus:
489  *
490  *	kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
491  *
492  * would produce output:
493  *
494  *	reg=3<BITTWO,BITONE>
495  *
496  * XXX:  %D  -- Hexdump, takes pointer and separator string:
497  *		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
498  *		("%*D", len, ptr, " " -> XX XX XX XX ...
499  */
500 int
501 kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap)
502 {
503 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; }
504 	char nbuf[MAXNBUF];
505 	char *d;
506 	const char *p, *percent, *q;
507 	u_char *up;
508 	int ch, n;
509 	uintmax_t num;
510 	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
511 	int cflag, hflag, jflag, tflag, zflag;
512 	int dwidth;
513 	char padc;
514 	int retval = 0;
515 
516 	num = 0;
517 	if (!func)
518 		d = (char *) arg;
519 	else
520 		d = NULL;
521 
522 	if (fmt == NULL)
523 		fmt = "(fmt null)\n";
524 
525 	if (radix < 2 || radix > 36)
526 		radix = 10;
527 
528 	for (;;) {
529 		padc = ' ';
530 		width = 0;
531 		while ((ch = (u_char)*fmt++) != '%') {
532 			if (ch == '\0')
533 				return (retval);
534 			PCHAR(ch);
535 		}
536 		percent = fmt - 1;
537 		qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
538 		sign = 0; dot = 0; dwidth = 0;
539 		cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
540 reswitch:	switch (ch = (u_char)*fmt++) {
541 		case '.':
542 			dot = 1;
543 			goto reswitch;
544 		case '#':
545 			sharpflag = 1;
546 			goto reswitch;
547 		case '+':
548 			sign = 1;
549 			goto reswitch;
550 		case '-':
551 			ladjust = 1;
552 			goto reswitch;
553 		case '%':
554 			PCHAR(ch);
555 			break;
556 		case '*':
557 			if (!dot) {
558 				width = va_arg(ap, int);
559 				if (width < 0) {
560 					ladjust = !ladjust;
561 					width = -width;
562 				}
563 			} else {
564 				dwidth = va_arg(ap, int);
565 			}
566 			goto reswitch;
567 		case '0':
568 			if (!dot) {
569 				padc = '0';
570 				goto reswitch;
571 			}
572 		case '1': case '2': case '3': case '4':
573 		case '5': case '6': case '7': case '8': case '9':
574 				for (n = 0;; ++fmt) {
575 					n = n * 10 + ch - '0';
576 					ch = *fmt;
577 					if (ch < '0' || ch > '9')
578 						break;
579 				}
580 			if (dot)
581 				dwidth = n;
582 			else
583 				width = n;
584 			goto reswitch;
585 		case 'b':
586 			num = (u_int)va_arg(ap, int);
587 			p = va_arg(ap, char *);
588 			for (q = ksprintn(nbuf, num, *p++, NULL); *q;)
589 				PCHAR(*q--);
590 
591 			if (num == 0)
592 				break;
593 
594 			for (tmp = 0; *p;) {
595 				n = *p++;
596 				if (num & (1 << (n - 1))) {
597 					PCHAR(tmp ? ',' : '<');
598 					for (; (n = *p) > ' '; ++p)
599 						PCHAR(n);
600 					tmp = 1;
601 				} else
602 					for (; *p > ' '; ++p)
603 						continue;
604 			}
605 			if (tmp)
606 				PCHAR('>');
607 			break;
608 		case 'c':
609 			PCHAR(va_arg(ap, int));
610 			break;
611 		case 'D':
612 			up = va_arg(ap, u_char *);
613 			p = va_arg(ap, char *);
614 			if (!width)
615 				width = 16;
616 			while(width--) {
617 				PCHAR(hex2ascii(*up >> 4));
618 				PCHAR(hex2ascii(*up & 0x0f));
619 				up++;
620 				if (width)
621 					for (q=p;*q;q++)
622 						PCHAR(*q);
623 			}
624 			break;
625 		case 'd':
626 		case 'i':
627 			base = 10;
628 			sign = 1;
629 			goto handle_sign;
630 		case 'h':
631 			if (hflag) {
632 				hflag = 0;
633 				cflag = 1;
634 			} else
635 				hflag = 1;
636 			goto reswitch;
637 		case 'j':
638 			jflag = 1;
639 			goto reswitch;
640 		case 'l':
641 			if (lflag) {
642 				lflag = 0;
643 				qflag = 1;
644 			} else
645 				lflag = 1;
646 			goto reswitch;
647 		case 'n':
648 			if (jflag)
649 				*(va_arg(ap, intmax_t *)) = retval;
650 			else if (qflag)
651 				*(va_arg(ap, quad_t *)) = retval;
652 			else if (lflag)
653 				*(va_arg(ap, long *)) = retval;
654 			else if (zflag)
655 				*(va_arg(ap, size_t *)) = retval;
656 			else if (hflag)
657 				*(va_arg(ap, short *)) = retval;
658 			else if (cflag)
659 				*(va_arg(ap, char *)) = retval;
660 			else
661 				*(va_arg(ap, int *)) = retval;
662 			break;
663 		case 'o':
664 			base = 8;
665 			goto handle_nosign;
666 		case 'p':
667 			base = 16;
668 			sharpflag = (width == 0);
669 			sign = 0;
670 			num = (uintptr_t)va_arg(ap, void *);
671 			goto number;
672 		case 'q':
673 			qflag = 1;
674 			goto reswitch;
675 		case 'r':
676 			base = radix;
677 			if (sign)
678 				goto handle_sign;
679 			goto handle_nosign;
680 		case 's':
681 			p = va_arg(ap, char *);
682 			if (p == NULL)
683 				p = "(null)";
684 			if (!dot)
685 				n = strlen (p);
686 			else
687 				for (n = 0; n < dwidth && p[n]; n++)
688 					continue;
689 
690 			width -= n;
691 
692 			if (!ladjust && width > 0)
693 				while (width--)
694 					PCHAR(padc);
695 			while (n--)
696 				PCHAR(*p++);
697 			if (ladjust && width > 0)
698 				while (width--)
699 					PCHAR(padc);
700 			break;
701 		case 't':
702 			tflag = 1;
703 			goto reswitch;
704 		case 'u':
705 			base = 10;
706 			goto handle_nosign;
707 		case 'x':
708 		case 'X':
709 			base = 16;
710 			goto handle_nosign;
711 		case 'y':
712 			base = 16;
713 			sign = 1;
714 			goto handle_sign;
715 		case 'z':
716 			zflag = 1;
717 			goto reswitch;
718 handle_nosign:
719 			sign = 0;
720 			if (jflag)
721 				num = va_arg(ap, uintmax_t);
722 			else if (qflag)
723 				num = va_arg(ap, u_quad_t);
724 			else if (tflag)
725 				num = va_arg(ap, ptrdiff_t);
726 			else if (lflag)
727 				num = va_arg(ap, u_long);
728 			else if (zflag)
729 				num = va_arg(ap, size_t);
730 			else if (hflag)
731 				num = (u_short)va_arg(ap, int);
732 			else if (cflag)
733 				num = (u_char)va_arg(ap, int);
734 			else
735 				num = va_arg(ap, u_int);
736 			goto number;
737 handle_sign:
738 			if (jflag)
739 				num = va_arg(ap, intmax_t);
740 			else if (qflag)
741 				num = va_arg(ap, quad_t);
742 			else if (tflag)
743 				num = va_arg(ap, ptrdiff_t);
744 			else if (lflag)
745 				num = va_arg(ap, long);
746 			else if (zflag)
747 				num = va_arg(ap, size_t);
748 			else if (hflag)
749 				num = (short)va_arg(ap, int);
750 			else if (cflag)
751 				num = (char)va_arg(ap, int);
752 			else
753 				num = va_arg(ap, int);
754 number:
755 			if (sign && (intmax_t)num < 0) {
756 				neg = 1;
757 				num = -(intmax_t)num;
758 			}
759 			p = ksprintn(nbuf, num, base, &tmp);
760 			if (sharpflag && num != 0) {
761 				if (base == 8)
762 					tmp++;
763 				else if (base == 16)
764 					tmp += 2;
765 			}
766 			if (neg)
767 				tmp++;
768 
769 			if (!ladjust && width && (width -= tmp) > 0)
770 				while (width--)
771 					PCHAR(padc);
772 			if (neg)
773 				PCHAR('-');
774 			if (sharpflag && num != 0) {
775 				if (base == 8) {
776 					PCHAR('0');
777 				} else if (base == 16) {
778 					PCHAR('0');
779 					PCHAR('x');
780 				}
781 			}
782 
783 			while (*p)
784 				PCHAR(*p--);
785 
786 			if (ladjust && width && (width -= tmp) > 0)
787 				while (width--)
788 					PCHAR(padc);
789 
790 			break;
791 		default:
792 			while (percent < fmt)
793 				PCHAR(*percent++);
794 			break;
795 		}
796 	}
797 #undef PCHAR
798 }
799 
800 /*
801  * Put character in log buffer with a particular priority.
802  */
803 static void
804 msglogchar(int c, int pri)
805 {
806 	static int lastpri = -1;
807 	static int dangling;
808 	char nbuf[MAXNBUF];
809 	char *p;
810 
811 	if (!msgbufmapped)
812 		return;
813 	if (c == '\0' || c == '\r')
814 		return;
815 	if (pri != -1 && pri != lastpri) {
816 		if (dangling) {
817 			msgbuf_addchar(msgbufp, '\n');
818 			dangling = 0;
819 		}
820 		msgbuf_addchar(msgbufp, '<');
821 		for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL); *p;)
822 			msgbuf_addchar(msgbufp, *p--);
823 		msgbuf_addchar(msgbufp, '>');
824 		lastpri = pri;
825 	}
826 	msgbuf_addchar(msgbufp, c);
827 	if (c == '\n') {
828 		dangling = 0;
829 		lastpri = -1;
830 	} else {
831 		dangling = 1;
832 	}
833 }
834 
835 void
836 msgbufinit(void *ptr, int size)
837 {
838 	char *cp;
839 	static struct msgbuf *oldp = NULL;
840 
841 	size -= sizeof(*msgbufp);
842 	cp = (char *)ptr;
843 	msgbufp = (struct msgbuf *)(cp + size);
844 	msgbuf_reinit(msgbufp, cp, size);
845 	if (msgbufmapped && oldp != msgbufp)
846 		msgbuf_copy(oldp, msgbufp);
847 	msgbufmapped = 1;
848 	oldp = msgbufp;
849 }
850 
851 SYSCTL_DECL(_security_bsd);
852 
853 static int unprivileged_read_msgbuf = 1;
854 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_read_msgbuf,
855     CTLFLAG_RW, &unprivileged_read_msgbuf, 0,
856     "Unprivileged processes may read the kernel message buffer");
857 
858 /* Sysctls for accessing/clearing the msgbuf */
859 static int
860 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
861 {
862 	char buf[128];
863 	u_int seq;
864 	int error, len;
865 
866 	if (!unprivileged_read_msgbuf) {
867 		error = suser(req->td);
868 		if (error)
869 			return (error);
870 	}
871 
872 	/* Read the whole buffer, one chunk at a time. */
873 	msgbuf_peekbytes(msgbufp, NULL, 0, &seq);
874 	while ((len = msgbuf_peekbytes(msgbufp, buf, sizeof(buf), &seq)) > 0) {
875 		error = sysctl_handle_opaque(oidp, buf, len, req);
876 		if (error)
877 			return (error);
878 	}
879 	return (0);
880 }
881 
882 SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD,
883     0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
884 
885 static int msgbuf_clearflag;
886 
887 static int
888 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
889 {
890 	int error;
891 	error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
892 	if (!error && req->newptr) {
893 		msgbuf_clear(msgbufp);
894 		msgbuf_clearflag = 0;
895 	}
896 	return (error);
897 }
898 
899 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
900     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clearflag, 0,
901     sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer");
902 
903 #ifdef DDB
904 
905 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
906 {
907 	int i, j;
908 
909 	if (!msgbufmapped) {
910 		db_printf("msgbuf not mapped yet\n");
911 		return;
912 	}
913 	db_printf("msgbufp = %p\n", msgbufp);
914 	db_printf("magic = %x, size = %d, r= %u, w = %u, ptr = %p, cksum= %u\n",
915 	    msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_rseq,
916 	    msgbufp->msg_wseq, msgbufp->msg_ptr, msgbufp->msg_cksum);
917 	for (i = 0; i < msgbufp->msg_size; i++) {
918 		j = MSGBUF_SEQ_TO_POS(msgbufp, i + msgbufp->msg_rseq);
919 		db_printf("%c", msgbufp->msg_ptr[j]);
920 	}
921 	db_printf("\n");
922 }
923 
924 #endif /* DDB */
925 
926 void
927 hexdump(void *ptr, int length, const char *hdr, int flags)
928 {
929 	int i, j, k;
930 	int cols;
931 	unsigned char *cp;
932 	char delim;
933 
934 	if ((flags & HD_DELIM_MASK) != 0)
935 		delim = (flags & HD_DELIM_MASK) >> 8;
936 	else
937 		delim = ' ';
938 
939 	if ((flags & HD_COLUMN_MASK) != 0)
940 		cols = flags & HD_COLUMN_MASK;
941 	else
942 		cols = 16;
943 
944 	cp = ptr;
945 	for (i = 0; i < length; i+= cols) {
946 		if (hdr != NULL)
947 			printf("%s", hdr);
948 
949 		if ((flags & HD_OMIT_COUNT) == 0)
950 			printf("%04x  ", i);
951 
952 		if ((flags & HD_OMIT_HEX) == 0) {
953 			for (j = 0; j < cols; j++) {
954 				k = i + j;
955 				if (k < length)
956 					printf("%c%02x", delim, cp[k]);
957 				else
958 					printf("   ");
959 			}
960 		}
961 
962 		if ((flags & HD_OMIT_CHARS) == 0) {
963 			printf("  |");
964 			for (j = 0; j < cols; j++) {
965 				k = i + j;
966 				if (k >= length)
967 					printf(" ");
968 				else if (cp[k] >= ' ' && cp[k] <= '~')
969 					printf("%c", cp[k]);
970 				else
971 					printf(".");
972 			}
973 			printf("|\n");
974 		}
975 	}
976 }
977 
978