xref: /freebsd/sys/kern/subr_prf.c (revision 39ee7a7a6bdd1557b1c3532abf60d139798ac88b)
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 #ifdef _KERNEL
41 #include "opt_ddb.h"
42 #include "opt_printf.h"
43 #endif  /* _KERNEL */
44 
45 #include <sys/param.h>
46 #ifdef _KERNEL
47 #include <sys/systm.h>
48 #include <sys/lock.h>
49 #include <sys/kdb.h>
50 #include <sys/mutex.h>
51 #include <sys/sx.h>
52 #include <sys/kernel.h>
53 #include <sys/msgbuf.h>
54 #include <sys/malloc.h>
55 #include <sys/priv.h>
56 #include <sys/proc.h>
57 #include <sys/stddef.h>
58 #include <sys/sysctl.h>
59 #include <sys/tty.h>
60 #include <sys/syslog.h>
61 #include <sys/cons.h>
62 #include <sys/uio.h>
63 #endif
64 #include <sys/ctype.h>
65 #include <sys/sbuf.h>
66 
67 #ifdef DDB
68 #include <ddb/ddb.h>
69 #endif
70 
71 /*
72  * Note that stdarg.h and the ANSI style va_start macro is used for both
73  * ANSI and traditional C compilers.
74  */
75 #include <machine/stdarg.h>
76 
77 #ifdef _KERNEL
78 
79 #define TOCONS	0x01
80 #define TOTTY	0x02
81 #define TOLOG	0x04
82 
83 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
84 #define MAXNBUF	(sizeof(intmax_t) * NBBY + 1)
85 
86 struct putchar_arg {
87 	int	flags;
88 	int	pri;
89 	struct	tty *tty;
90 	char	*p_bufr;
91 	size_t	n_bufr;
92 	char	*p_next;
93 	size_t	remain;
94 };
95 
96 struct snprintf_arg {
97 	char	*str;
98 	size_t	remain;
99 };
100 
101 extern	int log_open;
102 
103 static void  msglogchar(int c, int pri);
104 static void  msglogstr(char *str, int pri, int filter_cr);
105 static void  putchar(int ch, void *arg);
106 static char *ksprintn(char *nbuf, uintmax_t num, int base, int *len, int upper);
107 static void  snprintf_func(int ch, void *arg);
108 
109 static int msgbufmapped;		/* Set when safe to use msgbuf */
110 int msgbuftrigger;
111 
112 static int log_console_output = 1;
113 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RWTUN,
114     &log_console_output, 0, "Duplicate console output to the syslog");
115 
116 /*
117  * See the comment in log_console() below for more explanation of this.
118  */
119 static int log_console_add_linefeed;
120 SYSCTL_INT(_kern, OID_AUTO, log_console_add_linefeed, CTLFLAG_RWTUN,
121     &log_console_add_linefeed, 0, "log_console() adds extra newlines");
122 
123 static int always_console_output;
124 SYSCTL_INT(_kern, OID_AUTO, always_console_output, CTLFLAG_RWTUN,
125     &always_console_output, 0, "Always output to console despite TIOCCONS");
126 
127 /*
128  * Warn that a system table is full.
129  */
130 void
131 tablefull(const char *tab)
132 {
133 
134 	log(LOG_ERR, "%s: table is full\n", tab);
135 }
136 
137 /*
138  * Uprintf prints to the controlling terminal for the current process.
139  */
140 int
141 uprintf(const char *fmt, ...)
142 {
143 	va_list ap;
144 	struct putchar_arg pca;
145 	struct proc *p;
146 	struct thread *td;
147 	int retval;
148 
149 	td = curthread;
150 	if (TD_IS_IDLETHREAD(td))
151 		return (0);
152 
153 	sx_slock(&proctree_lock);
154 	p = td->td_proc;
155 	PROC_LOCK(p);
156 	if ((p->p_flag & P_CONTROLT) == 0) {
157 		PROC_UNLOCK(p);
158 		sx_sunlock(&proctree_lock);
159 		return (0);
160 	}
161 	SESS_LOCK(p->p_session);
162 	pca.tty = p->p_session->s_ttyp;
163 	SESS_UNLOCK(p->p_session);
164 	PROC_UNLOCK(p);
165 	if (pca.tty == NULL) {
166 		sx_sunlock(&proctree_lock);
167 		return (0);
168 	}
169 	pca.flags = TOTTY;
170 	pca.p_bufr = NULL;
171 	va_start(ap, fmt);
172 	tty_lock(pca.tty);
173 	sx_sunlock(&proctree_lock);
174 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
175 	tty_unlock(pca.tty);
176 	va_end(ap);
177 	return (retval);
178 }
179 
180 /*
181  * tprintf and vtprintf print on the controlling terminal associated with the
182  * given session, possibly to the log as well.
183  */
184 void
185 tprintf(struct proc *p, int pri, const char *fmt, ...)
186 {
187 	va_list ap;
188 
189 	va_start(ap, fmt);
190 	vtprintf(p, pri, fmt, ap);
191 	va_end(ap);
192 }
193 
194 void
195 vtprintf(struct proc *p, int pri, const char *fmt, va_list ap)
196 {
197 	struct tty *tp = NULL;
198 	int flags = 0;
199 	struct putchar_arg pca;
200 	struct session *sess = NULL;
201 
202 	sx_slock(&proctree_lock);
203 	if (pri != -1)
204 		flags |= TOLOG;
205 	if (p != NULL) {
206 		PROC_LOCK(p);
207 		if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
208 			sess = p->p_session;
209 			sess_hold(sess);
210 			PROC_UNLOCK(p);
211 			tp = sess->s_ttyp;
212 			if (tp != NULL && tty_checkoutq(tp))
213 				flags |= TOTTY;
214 			else
215 				tp = NULL;
216 		} else
217 			PROC_UNLOCK(p);
218 	}
219 	pca.pri = pri;
220 	pca.tty = tp;
221 	pca.flags = flags;
222 	pca.p_bufr = NULL;
223 	if (pca.tty != NULL)
224 		tty_lock(pca.tty);
225 	sx_sunlock(&proctree_lock);
226 	kvprintf(fmt, putchar, &pca, 10, ap);
227 	if (pca.tty != NULL)
228 		tty_unlock(pca.tty);
229 	if (sess != NULL)
230 		sess_release(sess);
231 	msgbuftrigger = 1;
232 }
233 
234 /*
235  * Ttyprintf displays a message on a tty; it should be used only by
236  * the tty driver, or anything that knows the underlying tty will not
237  * be revoke(2)'d away.  Other callers should use tprintf.
238  */
239 int
240 ttyprintf(struct tty *tp, const char *fmt, ...)
241 {
242 	va_list ap;
243 	struct putchar_arg pca;
244 	int retval;
245 
246 	va_start(ap, fmt);
247 	pca.tty = tp;
248 	pca.flags = TOTTY;
249 	pca.p_bufr = NULL;
250 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
251 	va_end(ap);
252 	return (retval);
253 }
254 
255 static int
256 _vprintf(int level, int flags, const char *fmt, va_list ap)
257 {
258 	struct putchar_arg pca;
259 	int retval;
260 #ifdef PRINTF_BUFR_SIZE
261 	char bufr[PRINTF_BUFR_SIZE];
262 #endif
263 
264 	pca.tty = NULL;
265 	pca.pri = level;
266 	pca.flags = flags;
267 #ifdef PRINTF_BUFR_SIZE
268 	pca.p_bufr = bufr;
269 	pca.p_next = pca.p_bufr;
270 	pca.n_bufr = sizeof(bufr);
271 	pca.remain = sizeof(bufr);
272 	*pca.p_next = '\0';
273 #else
274 	/* Don't buffer console output. */
275 	pca.p_bufr = NULL;
276 #endif
277 
278 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
279 
280 #ifdef PRINTF_BUFR_SIZE
281 	/* Write any buffered console/log output: */
282 	if (*pca.p_bufr != '\0') {
283 		if (pca.flags & TOLOG)
284 			msglogstr(pca.p_bufr, level, /*filter_cr*/1);
285 
286 		if (pca.flags & TOCONS)
287 			cnputs(pca.p_bufr);
288 	}
289 #endif
290 
291 	return (retval);
292 }
293 
294 /*
295  * Log writes to the log buffer, and guarantees not to sleep (so can be
296  * called by interrupt routines).  If there is no process reading the
297  * log yet, it writes to the console also.
298  */
299 void
300 log(int level, const char *fmt, ...)
301 {
302 	va_list ap;
303 
304 	va_start(ap, fmt);
305 	(void)_vprintf(level, log_open ? TOLOG : TOCONS | TOLOG, fmt, ap);
306 	va_end(ap);
307 
308 	msgbuftrigger = 1;
309 }
310 
311 #define CONSCHUNK 128
312 
313 void
314 log_console(struct uio *uio)
315 {
316 	int c, error, nl;
317 	char *consbuffer;
318 	int pri;
319 
320 	if (!log_console_output)
321 		return;
322 
323 	pri = LOG_INFO | LOG_CONSOLE;
324 	uio = cloneuio(uio);
325 	consbuffer = malloc(CONSCHUNK, M_TEMP, M_WAITOK);
326 
327 	nl = 0;
328 	while (uio->uio_resid > 0) {
329 		c = imin(uio->uio_resid, CONSCHUNK - 1);
330 		error = uiomove(consbuffer, c, uio);
331 		if (error != 0)
332 			break;
333 		/* Make sure we're NUL-terminated */
334 		consbuffer[c] = '\0';
335 		if (consbuffer[c - 1] == '\n')
336 			nl = 1;
337 		else
338 			nl = 0;
339 		msglogstr(consbuffer, pri, /*filter_cr*/ 1);
340 	}
341 	/*
342 	 * The previous behavior in log_console() is preserved when
343 	 * log_console_add_linefeed is non-zero.  For that behavior, if an
344 	 * individual console write came in that was not terminated with a
345 	 * line feed, it would add a line feed.
346 	 *
347 	 * This results in different data in the message buffer than
348 	 * appears on the system console (which doesn't add extra line feed
349 	 * characters).
350 	 *
351 	 * A number of programs and rc scripts write a line feed, or a period
352 	 * and a line feed when they have completed their operation.  On
353 	 * the console, this looks seamless, but when displayed with
354 	 * 'dmesg -a', you wind up with output that looks like this:
355 	 *
356 	 * Updating motd:
357 	 * .
358 	 *
359 	 * On the console, it looks like this:
360 	 * Updating motd:.
361 	 *
362 	 * We could add logic to detect that situation, or just not insert
363 	 * the extra newlines.  Set the kern.log_console_add_linefeed
364 	 * sysctl/tunable variable to get the old behavior.
365 	 */
366 	if (!nl && log_console_add_linefeed) {
367 		consbuffer[0] = '\n';
368 		consbuffer[1] = '\0';
369 		msglogstr(consbuffer, pri, /*filter_cr*/ 1);
370 	}
371 	msgbuftrigger = 1;
372 	free(uio, M_IOV);
373 	free(consbuffer, M_TEMP);
374 	return;
375 }
376 
377 int
378 printf(const char *fmt, ...)
379 {
380 	va_list ap;
381 	int retval;
382 
383 	va_start(ap, fmt);
384 	retval = vprintf(fmt, ap);
385 	va_end(ap);
386 
387 	return (retval);
388 }
389 
390 int
391 vprintf(const char *fmt, va_list ap)
392 {
393 	int retval;
394 
395 	retval = _vprintf(-1, TOCONS | TOLOG, fmt, ap);
396 
397 	if (!panicstr)
398 		msgbuftrigger = 1;
399 
400 	return (retval);
401 }
402 
403 static void
404 putbuf(int c, struct putchar_arg *ap)
405 {
406 	/* Check if no console output buffer was provided. */
407 	if (ap->p_bufr == NULL) {
408 		/* Output direct to the console. */
409 		if (ap->flags & TOCONS)
410 			cnputc(c);
411 
412 		if (ap->flags & TOLOG)
413 			msglogchar(c, ap->pri);
414 	} else {
415 		/* Buffer the character: */
416 		*ap->p_next++ = c;
417 		ap->remain--;
418 
419 		/* Always leave the buffer zero terminated. */
420 		*ap->p_next = '\0';
421 
422 		/* Check if the buffer needs to be flushed. */
423 		if (ap->remain == 2 || c == '\n') {
424 
425 			if (ap->flags & TOLOG)
426 				msglogstr(ap->p_bufr, ap->pri, /*filter_cr*/1);
427 
428 			if (ap->flags & TOCONS) {
429 				if ((panicstr == NULL) && (constty != NULL))
430 					msgbuf_addstr(&consmsgbuf, -1,
431 					    ap->p_bufr, /*filter_cr*/ 0);
432 
433 				if ((constty == NULL) ||(always_console_output))
434 					cnputs(ap->p_bufr);
435 			}
436 
437 			ap->p_next = ap->p_bufr;
438 			ap->remain = ap->n_bufr;
439 			*ap->p_next = '\0';
440 		}
441 
442 		/*
443 		 * Since we fill the buffer up one character at a time,
444 		 * this should not happen.  We should always catch it when
445 		 * ap->remain == 2 (if not sooner due to a newline), flush
446 		 * the buffer and move on.  One way this could happen is
447 		 * if someone sets PRINTF_BUFR_SIZE to 1 or something
448 		 * similarly silly.
449 		 */
450 		KASSERT(ap->remain > 2, ("Bad buffer logic, remain = %zd",
451 		    ap->remain));
452 	}
453 }
454 
455 /*
456  * Print a character on console or users terminal.  If destination is
457  * the console then the last bunch of characters are saved in msgbuf for
458  * inspection later.
459  */
460 static void
461 putchar(int c, void *arg)
462 {
463 	struct putchar_arg *ap = (struct putchar_arg*) arg;
464 	struct tty *tp = ap->tty;
465 	int flags = ap->flags;
466 
467 	/* Don't use the tty code after a panic or while in ddb. */
468 	if (kdb_active) {
469 		if (c != '\0')
470 			cnputc(c);
471 		return;
472 	}
473 
474 	if ((flags & TOTTY) && tp != NULL && panicstr == NULL)
475 		tty_putchar(tp, c);
476 
477 	if ((flags & (TOCONS | TOLOG)) && c != '\0')
478 		putbuf(c, ap);
479 }
480 
481 /*
482  * Scaled down version of sprintf(3).
483  */
484 int
485 sprintf(char *buf, const char *cfmt, ...)
486 {
487 	int retval;
488 	va_list ap;
489 
490 	va_start(ap, cfmt);
491 	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
492 	buf[retval] = '\0';
493 	va_end(ap);
494 	return (retval);
495 }
496 
497 /*
498  * Scaled down version of vsprintf(3).
499  */
500 int
501 vsprintf(char *buf, const char *cfmt, va_list ap)
502 {
503 	int retval;
504 
505 	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
506 	buf[retval] = '\0';
507 	return (retval);
508 }
509 
510 /*
511  * Scaled down version of snprintf(3).
512  */
513 int
514 snprintf(char *str, size_t size, const char *format, ...)
515 {
516 	int retval;
517 	va_list ap;
518 
519 	va_start(ap, format);
520 	retval = vsnprintf(str, size, format, ap);
521 	va_end(ap);
522 	return(retval);
523 }
524 
525 /*
526  * Scaled down version of vsnprintf(3).
527  */
528 int
529 vsnprintf(char *str, size_t size, const char *format, va_list ap)
530 {
531 	struct snprintf_arg info;
532 	int retval;
533 
534 	info.str = str;
535 	info.remain = size;
536 	retval = kvprintf(format, snprintf_func, &info, 10, ap);
537 	if (info.remain >= 1)
538 		*info.str++ = '\0';
539 	return (retval);
540 }
541 
542 /*
543  * Kernel version which takes radix argument vsnprintf(3).
544  */
545 int
546 vsnrprintf(char *str, size_t size, int radix, const char *format, va_list ap)
547 {
548 	struct snprintf_arg info;
549 	int retval;
550 
551 	info.str = str;
552 	info.remain = size;
553 	retval = kvprintf(format, snprintf_func, &info, radix, ap);
554 	if (info.remain >= 1)
555 		*info.str++ = '\0';
556 	return (retval);
557 }
558 
559 static void
560 snprintf_func(int ch, void *arg)
561 {
562 	struct snprintf_arg *const info = arg;
563 
564 	if (info->remain >= 2) {
565 		*info->str++ = ch;
566 		info->remain--;
567 	}
568 }
569 
570 /*
571  * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
572  * order; return an optional length and a pointer to the last character
573  * written in the buffer (i.e., the first character of the string).
574  * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
575  */
576 static char *
577 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
578 {
579 	char *p, c;
580 
581 	p = nbuf;
582 	*p = '\0';
583 	do {
584 		c = hex2ascii(num % base);
585 		*++p = upper ? toupper(c) : c;
586 	} while (num /= base);
587 	if (lenp)
588 		*lenp = p - nbuf;
589 	return (p);
590 }
591 
592 /*
593  * Scaled down version of printf(3).
594  *
595  * Two additional formats:
596  *
597  * The format %b is supported to decode error registers.
598  * Its usage is:
599  *
600  *	printf("reg=%b\n", regval, "<base><arg>*");
601  *
602  * where <base> is the output base expressed as a control character, e.g.
603  * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
604  * the first of which gives the bit number to be inspected (origin 1), and
605  * the next characters (up to a control character, i.e. a character <= 32),
606  * give the name of the register.  Thus:
607  *
608  *	kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE");
609  *
610  * would produce output:
611  *
612  *	reg=3<BITTWO,BITONE>
613  *
614  * XXX:  %D  -- Hexdump, takes pointer and separator string:
615  *		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
616  *		("%*D", len, ptr, " " -> XX XX XX XX ...
617  */
618 int
619 kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap)
620 {
621 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; }
622 	char nbuf[MAXNBUF];
623 	char *d;
624 	const char *p, *percent, *q;
625 	u_char *up;
626 	int ch, n;
627 	uintmax_t num;
628 	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
629 	int cflag, hflag, jflag, tflag, zflag;
630 	int dwidth, upper;
631 	char padc;
632 	int stop = 0, retval = 0;
633 
634 	num = 0;
635 	if (!func)
636 		d = (char *) arg;
637 	else
638 		d = NULL;
639 
640 	if (fmt == NULL)
641 		fmt = "(fmt null)\n";
642 
643 	if (radix < 2 || radix > 36)
644 		radix = 10;
645 
646 	for (;;) {
647 		padc = ' ';
648 		width = 0;
649 		while ((ch = (u_char)*fmt++) != '%' || stop) {
650 			if (ch == '\0')
651 				return (retval);
652 			PCHAR(ch);
653 		}
654 		percent = fmt - 1;
655 		qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
656 		sign = 0; dot = 0; dwidth = 0; upper = 0;
657 		cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
658 reswitch:	switch (ch = (u_char)*fmt++) {
659 		case '.':
660 			dot = 1;
661 			goto reswitch;
662 		case '#':
663 			sharpflag = 1;
664 			goto reswitch;
665 		case '+':
666 			sign = 1;
667 			goto reswitch;
668 		case '-':
669 			ladjust = 1;
670 			goto reswitch;
671 		case '%':
672 			PCHAR(ch);
673 			break;
674 		case '*':
675 			if (!dot) {
676 				width = va_arg(ap, int);
677 				if (width < 0) {
678 					ladjust = !ladjust;
679 					width = -width;
680 				}
681 			} else {
682 				dwidth = va_arg(ap, int);
683 			}
684 			goto reswitch;
685 		case '0':
686 			if (!dot) {
687 				padc = '0';
688 				goto reswitch;
689 			}
690 		case '1': case '2': case '3': case '4':
691 		case '5': case '6': case '7': case '8': case '9':
692 				for (n = 0;; ++fmt) {
693 					n = n * 10 + ch - '0';
694 					ch = *fmt;
695 					if (ch < '0' || ch > '9')
696 						break;
697 				}
698 			if (dot)
699 				dwidth = n;
700 			else
701 				width = n;
702 			goto reswitch;
703 		case 'b':
704 			num = (u_int)va_arg(ap, int);
705 			p = va_arg(ap, char *);
706 			for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
707 				PCHAR(*q--);
708 
709 			if (num == 0)
710 				break;
711 
712 			for (tmp = 0; *p;) {
713 				n = *p++;
714 				if (num & (1 << (n - 1))) {
715 					PCHAR(tmp ? ',' : '<');
716 					for (; (n = *p) > ' '; ++p)
717 						PCHAR(n);
718 					tmp = 1;
719 				} else
720 					for (; *p > ' '; ++p)
721 						continue;
722 			}
723 			if (tmp)
724 				PCHAR('>');
725 			break;
726 		case 'c':
727 			PCHAR(va_arg(ap, int));
728 			break;
729 		case 'D':
730 			up = va_arg(ap, u_char *);
731 			p = va_arg(ap, char *);
732 			if (!width)
733 				width = 16;
734 			while(width--) {
735 				PCHAR(hex2ascii(*up >> 4));
736 				PCHAR(hex2ascii(*up & 0x0f));
737 				up++;
738 				if (width)
739 					for (q=p;*q;q++)
740 						PCHAR(*q);
741 			}
742 			break;
743 		case 'd':
744 		case 'i':
745 			base = 10;
746 			sign = 1;
747 			goto handle_sign;
748 		case 'h':
749 			if (hflag) {
750 				hflag = 0;
751 				cflag = 1;
752 			} else
753 				hflag = 1;
754 			goto reswitch;
755 		case 'j':
756 			jflag = 1;
757 			goto reswitch;
758 		case 'l':
759 			if (lflag) {
760 				lflag = 0;
761 				qflag = 1;
762 			} else
763 				lflag = 1;
764 			goto reswitch;
765 		case 'n':
766 			if (jflag)
767 				*(va_arg(ap, intmax_t *)) = retval;
768 			else if (qflag)
769 				*(va_arg(ap, quad_t *)) = retval;
770 			else if (lflag)
771 				*(va_arg(ap, long *)) = retval;
772 			else if (zflag)
773 				*(va_arg(ap, size_t *)) = retval;
774 			else if (hflag)
775 				*(va_arg(ap, short *)) = retval;
776 			else if (cflag)
777 				*(va_arg(ap, char *)) = retval;
778 			else
779 				*(va_arg(ap, int *)) = retval;
780 			break;
781 		case 'o':
782 			base = 8;
783 			goto handle_nosign;
784 		case 'p':
785 			base = 16;
786 			sharpflag = (width == 0);
787 			sign = 0;
788 			num = (uintptr_t)va_arg(ap, void *);
789 			goto number;
790 		case 'q':
791 			qflag = 1;
792 			goto reswitch;
793 		case 'r':
794 			base = radix;
795 			if (sign)
796 				goto handle_sign;
797 			goto handle_nosign;
798 		case 's':
799 			p = va_arg(ap, char *);
800 			if (p == NULL)
801 				p = "(null)";
802 			if (!dot)
803 				n = strlen (p);
804 			else
805 				for (n = 0; n < dwidth && p[n]; n++)
806 					continue;
807 
808 			width -= n;
809 
810 			if (!ladjust && width > 0)
811 				while (width--)
812 					PCHAR(padc);
813 			while (n--)
814 				PCHAR(*p++);
815 			if (ladjust && width > 0)
816 				while (width--)
817 					PCHAR(padc);
818 			break;
819 		case 't':
820 			tflag = 1;
821 			goto reswitch;
822 		case 'u':
823 			base = 10;
824 			goto handle_nosign;
825 		case 'X':
826 			upper = 1;
827 		case 'x':
828 			base = 16;
829 			goto handle_nosign;
830 		case 'y':
831 			base = 16;
832 			sign = 1;
833 			goto handle_sign;
834 		case 'z':
835 			zflag = 1;
836 			goto reswitch;
837 handle_nosign:
838 			sign = 0;
839 			if (jflag)
840 				num = va_arg(ap, uintmax_t);
841 			else if (qflag)
842 				num = va_arg(ap, u_quad_t);
843 			else if (tflag)
844 				num = va_arg(ap, ptrdiff_t);
845 			else if (lflag)
846 				num = va_arg(ap, u_long);
847 			else if (zflag)
848 				num = va_arg(ap, size_t);
849 			else if (hflag)
850 				num = (u_short)va_arg(ap, int);
851 			else if (cflag)
852 				num = (u_char)va_arg(ap, int);
853 			else
854 				num = va_arg(ap, u_int);
855 			goto number;
856 handle_sign:
857 			if (jflag)
858 				num = va_arg(ap, intmax_t);
859 			else if (qflag)
860 				num = va_arg(ap, quad_t);
861 			else if (tflag)
862 				num = va_arg(ap, ptrdiff_t);
863 			else if (lflag)
864 				num = va_arg(ap, long);
865 			else if (zflag)
866 				num = va_arg(ap, ssize_t);
867 			else if (hflag)
868 				num = (short)va_arg(ap, int);
869 			else if (cflag)
870 				num = (char)va_arg(ap, int);
871 			else
872 				num = va_arg(ap, int);
873 number:
874 			if (sign && (intmax_t)num < 0) {
875 				neg = 1;
876 				num = -(intmax_t)num;
877 			}
878 			p = ksprintn(nbuf, num, base, &n, upper);
879 			tmp = 0;
880 			if (sharpflag && num != 0) {
881 				if (base == 8)
882 					tmp++;
883 				else if (base == 16)
884 					tmp += 2;
885 			}
886 			if (neg)
887 				tmp++;
888 
889 			if (!ladjust && padc == '0')
890 				dwidth = width - tmp;
891 			width -= tmp + imax(dwidth, n);
892 			dwidth -= n;
893 			if (!ladjust)
894 				while (width-- > 0)
895 					PCHAR(' ');
896 			if (neg)
897 				PCHAR('-');
898 			if (sharpflag && num != 0) {
899 				if (base == 8) {
900 					PCHAR('0');
901 				} else if (base == 16) {
902 					PCHAR('0');
903 					PCHAR('x');
904 				}
905 			}
906 			while (dwidth-- > 0)
907 				PCHAR('0');
908 
909 			while (*p)
910 				PCHAR(*p--);
911 
912 			if (ladjust)
913 				while (width-- > 0)
914 					PCHAR(' ');
915 
916 			break;
917 		default:
918 			while (percent < fmt)
919 				PCHAR(*percent++);
920 			/*
921 			 * Since we ignore a formatting argument it is no
922 			 * longer safe to obey the remaining formatting
923 			 * arguments as the arguments will no longer match
924 			 * the format specs.
925 			 */
926 			stop = 1;
927 			break;
928 		}
929 	}
930 #undef PCHAR
931 }
932 
933 /*
934  * Put character in log buffer with a particular priority.
935  */
936 static void
937 msglogchar(int c, int pri)
938 {
939 	static int lastpri = -1;
940 	static int dangling;
941 	char nbuf[MAXNBUF];
942 	char *p;
943 
944 	if (!msgbufmapped)
945 		return;
946 	if (c == '\0' || c == '\r')
947 		return;
948 	if (pri != -1 && pri != lastpri) {
949 		if (dangling) {
950 			msgbuf_addchar(msgbufp, '\n');
951 			dangling = 0;
952 		}
953 		msgbuf_addchar(msgbufp, '<');
954 		for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL, 0); *p;)
955 			msgbuf_addchar(msgbufp, *p--);
956 		msgbuf_addchar(msgbufp, '>');
957 		lastpri = pri;
958 	}
959 	msgbuf_addchar(msgbufp, c);
960 	if (c == '\n') {
961 		dangling = 0;
962 		lastpri = -1;
963 	} else {
964 		dangling = 1;
965 	}
966 }
967 
968 static void
969 msglogstr(char *str, int pri, int filter_cr)
970 {
971 	if (!msgbufmapped)
972 		return;
973 
974 	msgbuf_addstr(msgbufp, pri, str, filter_cr);
975 }
976 
977 void
978 msgbufinit(void *ptr, int size)
979 {
980 	char *cp;
981 	static struct msgbuf *oldp = NULL;
982 
983 	size -= sizeof(*msgbufp);
984 	cp = (char *)ptr;
985 	msgbufp = (struct msgbuf *)(cp + size);
986 	msgbuf_reinit(msgbufp, cp, size);
987 	if (msgbufmapped && oldp != msgbufp)
988 		msgbuf_copy(oldp, msgbufp);
989 	msgbufmapped = 1;
990 	oldp = msgbufp;
991 }
992 
993 static int unprivileged_read_msgbuf = 1;
994 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_read_msgbuf,
995     CTLFLAG_RW, &unprivileged_read_msgbuf, 0,
996     "Unprivileged processes may read the kernel message buffer");
997 
998 /* Sysctls for accessing/clearing the msgbuf */
999 static int
1000 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
1001 {
1002 	char buf[128];
1003 	u_int seq;
1004 	int error, len;
1005 
1006 	if (!unprivileged_read_msgbuf) {
1007 		error = priv_check(req->td, PRIV_MSGBUF);
1008 		if (error)
1009 			return (error);
1010 	}
1011 
1012 	/* Read the whole buffer, one chunk at a time. */
1013 	mtx_lock(&msgbuf_lock);
1014 	msgbuf_peekbytes(msgbufp, NULL, 0, &seq);
1015 	for (;;) {
1016 		len = msgbuf_peekbytes(msgbufp, buf, sizeof(buf), &seq);
1017 		mtx_unlock(&msgbuf_lock);
1018 		if (len == 0)
1019 			return (SYSCTL_OUT(req, "", 1)); /* add nulterm */
1020 
1021 		error = sysctl_handle_opaque(oidp, buf, len, req);
1022 		if (error)
1023 			return (error);
1024 
1025 		mtx_lock(&msgbuf_lock);
1026 	}
1027 }
1028 
1029 SYSCTL_PROC(_kern, OID_AUTO, msgbuf,
1030     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
1031     NULL, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
1032 
1033 static int msgbuf_clearflag;
1034 
1035 static int
1036 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
1037 {
1038 	int error;
1039 	error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
1040 	if (!error && req->newptr) {
1041 		mtx_lock(&msgbuf_lock);
1042 		msgbuf_clear(msgbufp);
1043 		mtx_unlock(&msgbuf_lock);
1044 		msgbuf_clearflag = 0;
1045 	}
1046 	return (error);
1047 }
1048 
1049 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
1050     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE | CTLFLAG_MPSAFE,
1051     &msgbuf_clearflag, 0, sysctl_kern_msgbuf_clear, "I",
1052     "Clear kernel message buffer");
1053 
1054 #ifdef DDB
1055 
1056 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
1057 {
1058 	int i, j;
1059 
1060 	if (!msgbufmapped) {
1061 		db_printf("msgbuf not mapped yet\n");
1062 		return;
1063 	}
1064 	db_printf("msgbufp = %p\n", msgbufp);
1065 	db_printf("magic = %x, size = %d, r= %u, w = %u, ptr = %p, cksum= %u\n",
1066 	    msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_rseq,
1067 	    msgbufp->msg_wseq, msgbufp->msg_ptr, msgbufp->msg_cksum);
1068 	for (i = 0; i < msgbufp->msg_size && !db_pager_quit; i++) {
1069 		j = MSGBUF_SEQ_TO_POS(msgbufp, i + msgbufp->msg_rseq);
1070 		db_printf("%c", msgbufp->msg_ptr[j]);
1071 	}
1072 	db_printf("\n");
1073 }
1074 
1075 #endif /* DDB */
1076 
1077 void
1078 hexdump(const void *ptr, int length, const char *hdr, int flags)
1079 {
1080 	int i, j, k;
1081 	int cols;
1082 	const unsigned char *cp;
1083 	char delim;
1084 
1085 	if ((flags & HD_DELIM_MASK) != 0)
1086 		delim = (flags & HD_DELIM_MASK) >> 8;
1087 	else
1088 		delim = ' ';
1089 
1090 	if ((flags & HD_COLUMN_MASK) != 0)
1091 		cols = flags & HD_COLUMN_MASK;
1092 	else
1093 		cols = 16;
1094 
1095 	cp = ptr;
1096 	for (i = 0; i < length; i+= cols) {
1097 		if (hdr != NULL)
1098 			printf("%s", hdr);
1099 
1100 		if ((flags & HD_OMIT_COUNT) == 0)
1101 			printf("%04x  ", i);
1102 
1103 		if ((flags & HD_OMIT_HEX) == 0) {
1104 			for (j = 0; j < cols; j++) {
1105 				k = i + j;
1106 				if (k < length)
1107 					printf("%c%02x", delim, cp[k]);
1108 				else
1109 					printf("   ");
1110 			}
1111 		}
1112 
1113 		if ((flags & HD_OMIT_CHARS) == 0) {
1114 			printf("  |");
1115 			for (j = 0; j < cols; j++) {
1116 				k = i + j;
1117 				if (k >= length)
1118 					printf(" ");
1119 				else if (cp[k] >= ' ' && cp[k] <= '~')
1120 					printf("%c", cp[k]);
1121 				else
1122 					printf(".");
1123 			}
1124 			printf("|");
1125 		}
1126 		printf("\n");
1127 	}
1128 }
1129 #endif /* _KERNEL */
1130 
1131 void
1132 sbuf_hexdump(struct sbuf *sb, const void *ptr, int length, const char *hdr,
1133 	     int flags)
1134 {
1135 	int i, j, k;
1136 	int cols;
1137 	const unsigned char *cp;
1138 	char delim;
1139 
1140 	if ((flags & HD_DELIM_MASK) != 0)
1141 		delim = (flags & HD_DELIM_MASK) >> 8;
1142 	else
1143 		delim = ' ';
1144 
1145 	if ((flags & HD_COLUMN_MASK) != 0)
1146 		cols = flags & HD_COLUMN_MASK;
1147 	else
1148 		cols = 16;
1149 
1150 	cp = ptr;
1151 	for (i = 0; i < length; i+= cols) {
1152 		if (hdr != NULL)
1153 			sbuf_printf(sb, "%s", hdr);
1154 
1155 		if ((flags & HD_OMIT_COUNT) == 0)
1156 			sbuf_printf(sb, "%04x  ", i);
1157 
1158 		if ((flags & HD_OMIT_HEX) == 0) {
1159 			for (j = 0; j < cols; j++) {
1160 				k = i + j;
1161 				if (k < length)
1162 					sbuf_printf(sb, "%c%02x", delim, cp[k]);
1163 				else
1164 					sbuf_printf(sb, "   ");
1165 			}
1166 		}
1167 
1168 		if ((flags & HD_OMIT_CHARS) == 0) {
1169 			sbuf_printf(sb, "  |");
1170 			for (j = 0; j < cols; j++) {
1171 				k = i + j;
1172 				if (k >= length)
1173 					sbuf_printf(sb, " ");
1174 				else if (cp[k] >= ' ' && cp[k] <= '~')
1175 					sbuf_printf(sb, "%c", cp[k]);
1176 				else
1177 					sbuf_printf(sb, ".");
1178 			}
1179 			sbuf_printf(sb, "|");
1180 		}
1181 		sbuf_printf(sb, "\n");
1182 	}
1183 }
1184 
1185