hexdump.c revision 150335 
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: head/sys/kern/subr_prf.c 150335 2005-09-19 16:51:43Z rwatson $");
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/kdb.h>
46#include <sys/mutex.h>
47#include <sys/sx.h>
48#include <sys/kernel.h>
49#include <sys/msgbuf.h>
50#include <sys/malloc.h>
51#include <sys/proc.h>
52#include <sys/stddef.h>
53#include <sys/sysctl.h>
54#include <sys/tty.h>
55#include <sys/syslog.h>
56#include <sys/cons.h>
57#include <sys/uio.h>
58
59#ifdef DDB
60#include <ddb/ddb.h>
61#endif
62
63/*
64 * Note that stdarg.h and the ANSI style va_start macro is used for both
65 * ANSI and traditional C compilers.
66 */
67#include <machine/stdarg.h>
68
69#define TOCONS	0x01
70#define TOTTY	0x02
71#define TOLOG	0x04
72
73/* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
74#define MAXNBUF	(sizeof(intmax_t) * NBBY + 1)
75
76struct putchar_arg {
77	int	flags;
78	int	pri;
79	struct	tty *tty;
80};
81
82struct snprintf_arg {
83	char	*str;
84	size_t	remain;
85};
86
87extern	int log_open;
88
89static void  msglogchar(int c, int pri);
90static void  putchar(int ch, void *arg);
91static char *ksprintn(char *nbuf, uintmax_t num, int base, int *len);
92static void  snprintf_func(int ch, void *arg);
93
94static int consintr = 1;		/* Ok to handle console interrupts? */
95static int msgbufmapped;		/* Set when safe to use msgbuf */
96int msgbuftrigger;
97
98static int      log_console_output = 1;
99TUNABLE_INT("kern.log_console_output", &log_console_output);
100SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW,
101    &log_console_output, 0, "Duplicate console output to the syslog.");
102
103static int	always_console_output = 0;
104TUNABLE_INT("kern.always_console_output", &always_console_output);
105SYSCTL_INT(_kern, OID_AUTO, always_console_output, CTLFLAG_RW,
106    &always_console_output, 0, "Always output to console despite TIOCCONS.");
107
108/*
109 * Warn that a system table is full.
110 */
111void
112tablefull(const char *tab)
113{
114
115	log(LOG_ERR, "%s: table is full\n", tab);
116}
117
118/*
119 * Uprintf prints to the controlling terminal for the current process.
120 * It may block if the tty queue is overfull.  No message is printed if
121 * the queue does not clear in a reasonable time.
122 */
123int
124uprintf(const char *fmt, ...)
125{
126	struct thread *td = curthread;
127	struct proc *p = td->td_proc;
128	va_list ap;
129	struct putchar_arg pca;
130	int retval;
131
132	GIANT_REQUIRED;
133
134	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "uprintf");
135
136	if (td == NULL || td == PCPU_GET(idlethread))
137		return (0);
138
139	p = td->td_proc;
140	PROC_LOCK(p);
141	if ((p->p_flag & P_CONTROLT) == 0) {
142		PROC_UNLOCK(p);
143		return (0);
144	}
145	SESS_LOCK(p->p_session);
146	pca.tty = p->p_session->s_ttyp;
147	SESS_UNLOCK(p->p_session);
148	PROC_UNLOCK(p);
149	if (pca.tty == NULL)
150		return (0);
151	pca.flags = TOTTY;
152	va_start(ap, fmt);
153	retval = kvprintf(fmt, putchar, &pca, 10, ap);
154	va_end(ap);
155
156	return (retval);
157}
158
159/*
160 * tprintf prints on the controlling terminal associated
161 * with the given session, possibly to the log as well.
162 */
163void
164tprintf(struct proc *p, int pri, const char *fmt, ...)
165{
166	struct tty *tp = NULL;
167	int flags = 0;
168	va_list ap;
169	struct putchar_arg pca;
170	struct session *sess = NULL;
171
172	GIANT_REQUIRED;
173
174	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "tprintf");
175
176	if (pri != -1)
177		flags |= TOLOG;
178	if (p != NULL) {
179		PROC_LOCK(p);
180		if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
181			sess = p->p_session;
182			SESS_LOCK(sess);
183			PROC_UNLOCK(p);
184			SESSHOLD(sess);
185			tp = sess->s_ttyp;
186			SESS_UNLOCK(sess);
187			if (ttycheckoutq(tp, 0))
188				flags |= TOTTY;
189			else
190				tp = NULL;
191		} else
192			PROC_UNLOCK(p);
193	}
194	pca.pri = pri;
195	pca.tty = tp;
196	pca.flags = flags;
197	va_start(ap, fmt);
198	kvprintf(fmt, putchar, &pca, 10, ap);
199	va_end(ap);
200	if (sess != NULL)
201		SESSRELE(sess);
202	msgbuftrigger = 1;
203}
204
205/*
206 * Ttyprintf displays a message on a tty; it should be used only by
207 * the tty driver, or anything that knows the underlying tty will not
208 * be revoke(2)'d away.  Other callers should use tprintf.
209 */
210int
211ttyprintf(struct tty *tp, const char *fmt, ...)
212{
213	va_list ap;
214	struct putchar_arg pca;
215	int retval;
216
217	va_start(ap, fmt);
218	pca.tty = tp;
219	pca.flags = TOTTY;
220	retval = kvprintf(fmt, putchar, &pca, 10, ap);
221	va_end(ap);
222	return (retval);
223}
224
225/*
226 * Log writes to the log buffer, and guarantees not to sleep (so can be
227 * called by interrupt routines).  If there is no process reading the
228 * log yet, it writes to the console also.
229 */
230void
231log(int level, const char *fmt, ...)
232{
233	va_list ap;
234	struct putchar_arg pca;
235
236	pca.tty = NULL;
237	pca.pri = level;
238	pca.flags = log_open ? TOLOG : TOCONS;
239
240	va_start(ap, fmt);
241	kvprintf(fmt, putchar, &pca, 10, ap);
242	va_end(ap);
243
244	msgbuftrigger = 1;
245}
246
247#define CONSCHUNK 128
248
249void
250log_console(struct uio *uio)
251{
252	int c, i, error, nl;
253	char *consbuffer;
254	int pri;
255
256	if (!log_console_output)
257		return;
258
259	pri = LOG_INFO | LOG_CONSOLE;
260	uio = cloneuio(uio);
261	consbuffer = malloc(CONSCHUNK, M_TEMP, M_WAITOK);
262
263	nl = 0;
264	while (uio->uio_resid > 0) {
265		c = imin(uio->uio_resid, CONSCHUNK);
266		error = uiomove(consbuffer, c, uio);
267		if (error != 0)
268			break;
269		for (i = 0; i < c; i++) {
270			msglogchar(consbuffer[i], pri);
271			if (consbuffer[i] == '\n')
272				nl = 1;
273			else
274				nl = 0;
275		}
276	}
277	if (!nl)
278		msglogchar('\n', pri);
279	msgbuftrigger = 1;
280	free(uio, M_IOV);
281	free(consbuffer, M_TEMP);
282	return;
283}
284
285int
286printf(const char *fmt, ...)
287{
288	va_list ap;
289	int savintr;
290	struct putchar_arg pca;
291	int retval;
292
293	savintr = consintr;		/* disable interrupts */
294	consintr = 0;
295	va_start(ap, fmt);
296	pca.tty = NULL;
297	pca.flags = TOCONS | TOLOG;
298	pca.pri = -1;
299	retval = kvprintf(fmt, putchar, &pca, 10, ap);
300	va_end(ap);
301	if (!panicstr)
302		msgbuftrigger = 1;
303	consintr = savintr;		/* reenable interrupts */
304	return (retval);
305}
306
307int
308vprintf(const char *fmt, va_list ap)
309{
310	int savintr;
311	struct putchar_arg pca;
312	int retval;
313
314	savintr = consintr;		/* disable interrupts */
315	consintr = 0;
316	pca.tty = NULL;
317	pca.flags = TOCONS | TOLOG;
318	pca.pri = -1;
319	retval = kvprintf(fmt, putchar, &pca, 10, ap);
320	if (!panicstr)
321		msgbuftrigger = 1;
322	consintr = savintr;		/* reenable interrupts */
323	return (retval);
324}
325
326/*
327 * Print a character on console or users terminal.  If destination is
328 * the console then the last bunch of characters are saved in msgbuf for
329 * inspection later.
330 */
331static void
332putchar(int c, void *arg)
333{
334	struct putchar_arg *ap = (struct putchar_arg*) arg;
335	struct tty *tp = ap->tty;
336	int consdirect, flags = ap->flags;
337
338	consdirect = ((flags & TOCONS) && constty == NULL);
339	/* Don't use the tty code after a panic or while in ddb. */
340	if (panicstr)
341		consdirect = 1;
342	if (kdb_active)
343		consdirect = 1;
344	if (consdirect) {
345		if (c != '\0')
346			cnputc(c);
347	} else {
348		if ((flags & TOTTY) && tp != NULL)
349			tputchar(c, tp);
350		if (flags & TOCONS) {
351			if (constty != NULL)
352				msgbuf_addchar(&consmsgbuf, c);
353			if (always_console_output && c != '\0')
354				cnputc(c);
355		}
356	}
357	if ((flags & TOLOG))
358		msglogchar(c, ap->pri);
359}
360
361/*
362 * Scaled down version of sprintf(3).
363 */
364int
365sprintf(char *buf, const char *cfmt, ...)
366{
367	int retval;
368	va_list ap;
369
370	va_start(ap, cfmt);
371	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
372	buf[retval] = '\0';
373	va_end(ap);
374	return (retval);
375}
376
377/*
378 * Scaled down version of vsprintf(3).
379 */
380int
381vsprintf(char *buf, const char *cfmt, va_list ap)
382{
383	int retval;
384
385	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
386	buf[retval] = '\0';
387	return (retval);
388}
389
390/*
391 * Scaled down version of snprintf(3).
392 */
393int
394snprintf(char *str, size_t size, const char *format, ...)
395{
396	int retval;
397	va_list ap;
398
399	va_start(ap, format);
400	retval = vsnprintf(str, size, format, ap);
401	va_end(ap);
402	return(retval);
403}
404
405/*
406 * Scaled down version of vsnprintf(3).
407 */
408int
409vsnprintf(char *str, size_t size, const char *format, va_list ap)
410{
411	struct snprintf_arg info;
412	int retval;
413
414	info.str = str;
415	info.remain = size;
416	retval = kvprintf(format, snprintf_func, &info, 10, ap);
417	if (info.remain >= 1)
418		*info.str++ = '\0';
419	return (retval);
420}
421
422/*
423 * Kernel version which takes radix argument vsnprintf(3).
424 */
425int
426vsnrprintf(char *str, size_t size, int radix, const char *format, va_list ap)
427{
428	struct snprintf_arg info;
429	int retval;
430
431	info.str = str;
432	info.remain = size;
433	retval = kvprintf(format, snprintf_func, &info, radix, ap);
434	if (info.remain >= 1)
435		*info.str++ = '\0';
436	return (retval);
437}
438
439static void
440snprintf_func(int ch, void *arg)
441{
442	struct snprintf_arg *const info = arg;
443
444	if (info->remain >= 2) {
445		*info->str++ = ch;
446		info->remain--;
447	}
448}
449
450/*
451 * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
452 * order; return an optional length and a pointer to the last character
453 * written in the buffer (i.e., the first character of the string).
454 * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
455 */
456static char *
457ksprintn(char *nbuf, uintmax_t num, int base, int *lenp)
458{
459	char *p;
460
461	p = nbuf;
462	*p = '\0';
463	do {
464		*++p = hex2ascii(num % base);
465	} while (num /= base);
466	if (lenp)
467		*lenp = p - nbuf;
468	return (p);
469}
470
471/*
472 * Scaled down version of printf(3).
473 *
474 * Two additional formats:
475 *
476 * The format %b is supported to decode error registers.
477 * Its usage is:
478 *
479 *	printf("reg=%b\n", regval, "<base><arg>*");
480 *
481 * where <base> is the output base expressed as a control character, e.g.
482 * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
483 * the first of which gives the bit number to be inspected (origin 1), and
484 * the next characters (up to a control character, i.e. a character <= 32),
485 * give the name of the register.  Thus:
486 *
487 *	kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
488 *
489 * would produce output:
490 *
491 *	reg=3<BITTWO,BITONE>
492 *
493 * XXX:  %D  -- Hexdump, takes pointer and separator string:
494 *		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
495 *		("%*D", len, ptr, " " -> XX XX XX XX ...
496 */
497int
498kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap)
499{
500#define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; }
501	char nbuf[MAXNBUF];
502	char *d;
503	const char *p, *percent, *q;
504	u_char *up;
505	int ch, n;
506	uintmax_t num;
507	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
508	int cflag, hflag, jflag, tflag, zflag;
509	int dwidth;
510	char padc;
511	int stop = 0, retval = 0;
512
513	num = 0;
514	if (!func)
515		d = (char *) arg;
516	else
517		d = NULL;
518
519	if (fmt == NULL)
520		fmt = "(fmt null)\n";
521
522	if (radix < 2 || radix > 36)
523		radix = 10;
524
525	for (;;) {
526		padc = ' ';
527		width = 0;
528		while ((ch = (u_char)*fmt++) != '%' || stop) {
529			if (ch == '\0')
530				return (retval);
531			PCHAR(ch);
532		}
533		percent = fmt - 1;
534		qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
535		sign = 0; dot = 0; dwidth = 0;
536		cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
537reswitch:	switch (ch = (u_char)*fmt++) {
538		case '.':
539			dot = 1;
540			goto reswitch;
541		case '#':
542			sharpflag = 1;
543			goto reswitch;
544		case '+':
545			sign = 1;
546			goto reswitch;
547		case '-':
548			ladjust = 1;
549			goto reswitch;
550		case '%':
551			PCHAR(ch);
552			break;
553		case '*':
554			if (!dot) {
555				width = va_arg(ap, int);
556				if (width < 0) {
557					ladjust = !ladjust;
558					width = -width;
559				}
560			} else {
561				dwidth = va_arg(ap, int);
562			}
563			goto reswitch;
564		case '0':
565			if (!dot) {
566				padc = '0';
567				goto reswitch;
568			}
569		case '1': case '2': case '3': case '4':
570		case '5': case '6': case '7': case '8': case '9':
571				for (n = 0;; ++fmt) {
572					n = n * 10 + ch - '0';
573					ch = *fmt;
574					if (ch < '0' || ch > '9')
575						break;
576				}
577			if (dot)
578				dwidth = n;
579			else
580				width = n;
581			goto reswitch;
582		case 'b':
583			num = (u_int)va_arg(ap, int);
584			p = va_arg(ap, char *);
585			for (q = ksprintn(nbuf, num, *p++, NULL); *q;)
586				PCHAR(*q--);
587
588			if (num == 0)
589				break;
590
591			for (tmp = 0; *p;) {
592				n = *p++;
593				if (num & (1 << (n - 1))) {
594					PCHAR(tmp ? ',' : '<');
595					for (; (n = *p) > ' '; ++p)
596						PCHAR(n);
597					tmp = 1;
598				} else
599					for (; *p > ' '; ++p)
600						continue;
601			}
602			if (tmp)
603				PCHAR('>');
604			break;
605		case 'c':
606			PCHAR(va_arg(ap, int));
607			break;
608		case 'D':
609			up = va_arg(ap, u_char *);
610			p = va_arg(ap, char *);
611			if (!width)
612				width = 16;
613			while(width--) {
614				PCHAR(hex2ascii(*up >> 4));
615				PCHAR(hex2ascii(*up & 0x0f));
616				up++;
617				if (width)
618					for (q=p;*q;q++)
619						PCHAR(*q);
620			}
621			break;
622		case 'd':
623		case 'i':
624			base = 10;
625			sign = 1;
626			goto handle_sign;
627		case 'h':
628			if (hflag) {
629				hflag = 0;
630				cflag = 1;
631			} else
632				hflag = 1;
633			goto reswitch;
634		case 'j':
635			jflag = 1;
636			goto reswitch;
637		case 'l':
638			if (lflag) {
639				lflag = 0;
640				qflag = 1;
641			} else
642				lflag = 1;
643			goto reswitch;
644		case 'n':
645			if (jflag)
646				*(va_arg(ap, intmax_t *)) = retval;
647			else if (qflag)
648				*(va_arg(ap, quad_t *)) = retval;
649			else if (lflag)
650				*(va_arg(ap, long *)) = retval;
651			else if (zflag)
652				*(va_arg(ap, size_t *)) = retval;
653			else if (hflag)
654				*(va_arg(ap, short *)) = retval;
655			else if (cflag)
656				*(va_arg(ap, char *)) = retval;
657			else
658				*(va_arg(ap, int *)) = retval;
659			break;
660		case 'o':
661			base = 8;
662			goto handle_nosign;
663		case 'p':
664			base = 16;
665			sharpflag = (width == 0);
666			sign = 0;
667			num = (uintptr_t)va_arg(ap, void *);
668			goto number;
669		case 'q':
670			qflag = 1;
671			goto reswitch;
672		case 'r':
673			base = radix;
674			if (sign)
675				goto handle_sign;
676			goto handle_nosign;
677		case 's':
678			p = va_arg(ap, char *);
679			if (p == NULL)
680				p = "(null)";
681			if (!dot)
682				n = strlen (p);
683			else
684				for (n = 0; n < dwidth && p[n]; n++)
685					continue;
686
687			width -= n;
688
689			if (!ladjust && width > 0)
690				while (width--)
691					PCHAR(padc);
692			while (n--)
693				PCHAR(*p++);
694			if (ladjust && width > 0)
695				while (width--)
696					PCHAR(padc);
697			break;
698		case 't':
699			tflag = 1;
700			goto reswitch;
701		case 'u':
702			base = 10;
703			goto handle_nosign;
704		case 'x':
705		case 'X':
706			base = 16;
707			goto handle_nosign;
708		case 'y':
709			base = 16;
710			sign = 1;
711			goto handle_sign;
712		case 'z':
713			zflag = 1;
714			goto reswitch;
715handle_nosign:
716			sign = 0;
717			if (jflag)
718				num = va_arg(ap, uintmax_t);
719			else if (qflag)
720				num = va_arg(ap, u_quad_t);
721			else if (tflag)
722				num = va_arg(ap, ptrdiff_t);
723			else if (lflag)
724				num = va_arg(ap, u_long);
725			else if (zflag)
726				num = va_arg(ap, size_t);
727			else if (hflag)
728				num = (u_short)va_arg(ap, int);
729			else if (cflag)
730				num = (u_char)va_arg(ap, int);
731			else
732				num = va_arg(ap, u_int);
733			goto number;
734handle_sign:
735			if (jflag)
736				num = va_arg(ap, intmax_t);
737			else if (qflag)
738				num = va_arg(ap, quad_t);
739			else if (tflag)
740				num = va_arg(ap, ptrdiff_t);
741			else if (lflag)
742				num = va_arg(ap, long);
743			else if (zflag)
744				num = va_arg(ap, size_t);
745			else if (hflag)
746				num = (short)va_arg(ap, int);
747			else if (cflag)
748				num = (char)va_arg(ap, int);
749			else
750				num = va_arg(ap, int);
751number:
752			if (sign && (intmax_t)num < 0) {
753				neg = 1;
754				num = -(intmax_t)num;
755			}
756			p = ksprintn(nbuf, num, base, &tmp);
757			if (sharpflag && num != 0) {
758				if (base == 8)
759					tmp++;
760				else if (base == 16)
761					tmp += 2;
762			}
763			if (neg)
764				tmp++;
765
766			if (!ladjust && padc != '0' && width
767			    && (width -= tmp) > 0)
768				while (width--)
769					PCHAR(padc);
770			if (neg)
771				PCHAR('-');
772			if (sharpflag && num != 0) {
773				if (base == 8) {
774					PCHAR('0');
775				} else if (base == 16) {
776					PCHAR('0');
777					PCHAR('x');
778				}
779			}
780			if (!ladjust && width && (width -= tmp) > 0)
781				while (width--)
782					PCHAR(padc);
783
784			while (*p)
785				PCHAR(*p--);
786
787			if (ladjust && width && (width -= tmp) > 0)
788				while (width--)
789					PCHAR(padc);
790
791			break;
792		default:
793			while (percent < fmt)
794				PCHAR(*percent++);
795			/*
796			 * Since we ignore an formatting argument it is no
797			 * longer safe to obey the remaining formatting
798			 * arguments as the arguments will no longer match
799			 * the format specs.
800			 */
801			stop = 1;
802			break;
803		}
804	}
805#undef PCHAR
806}
807
808/*
809 * Put character in log buffer with a particular priority.
810 */
811static void
812msglogchar(int c, int pri)
813{
814	static int lastpri = -1;
815	static int dangling;
816	char nbuf[MAXNBUF];
817	char *p;
818
819	if (!msgbufmapped)
820		return;
821	if (c == '\0' || c == '\r')
822		return;
823	if (pri != -1 && pri != lastpri) {
824		if (dangling) {
825			msgbuf_addchar(msgbufp, '\n');
826			dangling = 0;
827		}
828		msgbuf_addchar(msgbufp, '<');
829		for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL); *p;)
830			msgbuf_addchar(msgbufp, *p--);
831		msgbuf_addchar(msgbufp, '>');
832		lastpri = pri;
833	}
834	msgbuf_addchar(msgbufp, c);
835	if (c == '\n') {
836		dangling = 0;
837		lastpri = -1;
838	} else {
839		dangling = 1;
840	}
841}
842
843void
844msgbufinit(void *ptr, int size)
845{
846	char *cp;
847	static struct msgbuf *oldp = NULL;
848
849	size -= sizeof(*msgbufp);
850	cp = (char *)ptr;
851	msgbufp = (struct msgbuf *)(cp + size);
852	msgbuf_reinit(msgbufp, cp, size);
853	if (msgbufmapped && oldp != msgbufp)
854		msgbuf_copy(oldp, msgbufp);
855	msgbufmapped = 1;
856	oldp = msgbufp;
857}
858
859SYSCTL_DECL(_security_bsd);
860
861static int unprivileged_read_msgbuf = 1;
862SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_read_msgbuf,
863    CTLFLAG_RW, &unprivileged_read_msgbuf, 0,
864    "Unprivileged processes may read the kernel message buffer");
865
866/* Sysctls for accessing/clearing the msgbuf */
867static int
868sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
869{
870	char buf[128];
871	u_int seq;
872	int error, len;
873
874	if (!unprivileged_read_msgbuf) {
875		error = suser(req->td);
876		if (error)
877			return (error);
878	}
879
880	/* Read the whole buffer, one chunk at a time. */
881	msgbuf_peekbytes(msgbufp, NULL, 0, &seq);
882	while ((len = msgbuf_peekbytes(msgbufp, buf, sizeof(buf), &seq)) > 0) {
883		error = sysctl_handle_opaque(oidp, buf, len, req);
884		if (error)
885			return (error);
886	}
887	return (0);
888}
889
890SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD,
891    0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
892
893static int msgbuf_clearflag;
894
895static int
896sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
897{
898	int error;
899	error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
900	if (!error && req->newptr) {
901		msgbuf_clear(msgbufp);
902		msgbuf_clearflag = 0;
903	}
904	return (error);
905}
906
907SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
908    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clearflag, 0,
909    sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer");
910
911#ifdef DDB
912
913DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
914{
915	int i, j, quit;
916
917	quit = 0;
918
919	if (!msgbufmapped) {
920		db_printf("msgbuf not mapped yet\n");
921		return;
922	}
923	db_setup_paging(db_simple_pager, &quit, db_lines_per_page);
924	db_printf("msgbufp = %p\n", msgbufp);
925	db_printf("magic = %x, size = %d, r= %u, w = %u, ptr = %p, cksum= %u\n",
926	    msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_rseq,
927	    msgbufp->msg_wseq, msgbufp->msg_ptr, msgbufp->msg_cksum);
928	for (i = 0; i < msgbufp->msg_size && !quit; i++) {
929		j = MSGBUF_SEQ_TO_POS(msgbufp, i + msgbufp->msg_rseq);
930		db_printf("%c", msgbufp->msg_ptr[j]);
931	}
932	db_printf("\n");
933}
934
935#endif /* DDB */
936
937void
938hexdump(const void *ptr, int length, const char *hdr, int flags)
939{
940	int i, j, k;
941	int cols;
942	const unsigned char *cp;
943	char delim;
944
945	if ((flags & HD_DELIM_MASK) != 0)
946		delim = (flags & HD_DELIM_MASK) >> 8;
947	else
948		delim = ' ';
949
950	if ((flags & HD_COLUMN_MASK) != 0)
951		cols = flags & HD_COLUMN_MASK;
952	else
953		cols = 16;
954
955	cp = ptr;
956	for (i = 0; i < length; i+= cols) {
957		if (hdr != NULL)
958			printf("%s", hdr);
959
960		if ((flags & HD_OMIT_COUNT) == 0)
961			printf("%04x  ", i);
962
963		if ((flags & HD_OMIT_HEX) == 0) {
964			for (j = 0; j < cols; j++) {
965				k = i + j;
966				if (k < length)
967					printf("%c%02x", delim, cp[k]);
968				else
969					printf("   ");
970			}
971		}
972
973		if ((flags & HD_OMIT_CHARS) == 0) {
974			printf("  |");
975			for (j = 0; j < cols; j++) {
976				k = i + j;
977				if (k >= length)
978					printf(" ");
979				else if (cp[k] >= ' ' && cp[k] <= '~')
980					printf("%c", cp[k]);
981				else
982					printf(".");
983			}
984			printf("|\n");
985		}
986	}
987}
988
989