xref: /freebsd/sys/kern/subr_prf.c (revision 809a8352dd5bb83dca991ff6c82e509208afad26)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1986, 1988, 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  * (c) UNIX System Laboratories, Inc.
7  * All or some portions of this file are derived from material licensed
8  * to the University of California by American Telephone and Telegraph
9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10  * the permission of UNIX System Laboratories, Inc.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
37  */
38 
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #ifdef _KERNEL
43 #include "opt_ddb.h"
44 #include "opt_printf.h"
45 #endif  /* _KERNEL */
46 
47 #include <sys/param.h>
48 #ifdef _KERNEL
49 #include <sys/systm.h>
50 #include <sys/lock.h>
51 #include <sys/kdb.h>
52 #include <sys/mutex.h>
53 #include <sys/sx.h>
54 #include <sys/kernel.h>
55 #include <sys/msgbuf.h>
56 #include <sys/malloc.h>
57 #include <sys/priv.h>
58 #include <sys/proc.h>
59 #include <sys/stddef.h>
60 #include <sys/sysctl.h>
61 #include <sys/tty.h>
62 #include <sys/syslog.h>
63 #include <sys/cons.h>
64 #include <sys/uio.h>
65 #endif
66 #include <sys/ctype.h>
67 #include <sys/sbuf.h>
68 
69 #ifdef DDB
70 #include <ddb/ddb.h>
71 #endif
72 
73 /*
74  * Note that stdarg.h and the ANSI style va_start macro is used for both
75  * ANSI and traditional C compilers.
76  */
77 #ifdef _KERNEL
78 #include <machine/stdarg.h>
79 #else
80 #include <stdarg.h>
81 #endif
82 
83 /*
84  * This is needed for sbuf_putbuf() when compiled into userland.  Due to the
85  * shared nature of this file, it's the only place to put it.
86  */
87 #ifndef _KERNEL
88 #include <stdio.h>
89 #endif
90 
91 #ifdef _KERNEL
92 
93 #define TOCONS	0x01
94 #define TOTTY	0x02
95 #define TOLOG	0x04
96 
97 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
98 #define MAXNBUF	(sizeof(intmax_t) * NBBY + 1)
99 
100 struct putchar_arg {
101 	int	flags;
102 	int	pri;
103 	struct	tty *tty;
104 	char	*p_bufr;
105 	size_t	n_bufr;
106 	char	*p_next;
107 	size_t	remain;
108 };
109 
110 struct snprintf_arg {
111 	char	*str;
112 	size_t	remain;
113 };
114 
115 extern	int log_open;
116 
117 static void  msglogchar(int c, int pri);
118 static void  msglogstr(char *str, int pri, int filter_cr);
119 static void  putchar(int ch, void *arg);
120 static char *ksprintn(char *nbuf, uintmax_t num, int base, int *len, int upper);
121 static void  snprintf_func(int ch, void *arg);
122 
123 static bool msgbufmapped;		/* Set when safe to use msgbuf */
124 int msgbuftrigger;
125 struct msgbuf *msgbufp;
126 
127 #ifndef BOOT_TAG_SZ
128 #define	BOOT_TAG_SZ	32
129 #endif
130 #ifndef BOOT_TAG
131 /* Tag used to mark the start of a boot in dmesg */
132 #define	BOOT_TAG	"---<<BOOT>>---"
133 #endif
134 
135 static char current_boot_tag[BOOT_TAG_SZ + 1] = BOOT_TAG;
136 SYSCTL_STRING(_kern, OID_AUTO, boot_tag, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
137     current_boot_tag, 0, "Tag added to dmesg at start of boot");
138 
139 static int log_console_output = 1;
140 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RWTUN,
141     &log_console_output, 0, "Duplicate console output to the syslog");
142 
143 /*
144  * See the comment in log_console() below for more explanation of this.
145  */
146 static int log_console_add_linefeed;
147 SYSCTL_INT(_kern, OID_AUTO, log_console_add_linefeed, CTLFLAG_RWTUN,
148     &log_console_add_linefeed, 0, "log_console() adds extra newlines");
149 
150 static int always_console_output;
151 SYSCTL_INT(_kern, OID_AUTO, always_console_output, CTLFLAG_RWTUN,
152     &always_console_output, 0, "Always output to console despite TIOCCONS");
153 
154 /*
155  * Warn that a system table is full.
156  */
157 void
158 tablefull(const char *tab)
159 {
160 
161 	log(LOG_ERR, "%s: table is full\n", tab);
162 }
163 
164 /*
165  * Uprintf prints to the controlling terminal for the current process.
166  */
167 int
168 uprintf(const char *fmt, ...)
169 {
170 	va_list ap;
171 	struct putchar_arg pca;
172 	struct proc *p;
173 	struct thread *td;
174 	int retval;
175 
176 	td = curthread;
177 	if (TD_IS_IDLETHREAD(td))
178 		return (0);
179 
180 	sx_slock(&proctree_lock);
181 	p = td->td_proc;
182 	PROC_LOCK(p);
183 	if ((p->p_flag & P_CONTROLT) == 0) {
184 		PROC_UNLOCK(p);
185 		sx_sunlock(&proctree_lock);
186 		return (0);
187 	}
188 	SESS_LOCK(p->p_session);
189 	pca.tty = p->p_session->s_ttyp;
190 	SESS_UNLOCK(p->p_session);
191 	PROC_UNLOCK(p);
192 	if (pca.tty == NULL) {
193 		sx_sunlock(&proctree_lock);
194 		return (0);
195 	}
196 	pca.flags = TOTTY;
197 	pca.p_bufr = NULL;
198 	va_start(ap, fmt);
199 	tty_lock(pca.tty);
200 	sx_sunlock(&proctree_lock);
201 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
202 	tty_unlock(pca.tty);
203 	va_end(ap);
204 	return (retval);
205 }
206 
207 /*
208  * tprintf and vtprintf print on the controlling terminal associated with the
209  * given session, possibly to the log as well.
210  */
211 void
212 tprintf(struct proc *p, int pri, const char *fmt, ...)
213 {
214 	va_list ap;
215 
216 	va_start(ap, fmt);
217 	vtprintf(p, pri, fmt, ap);
218 	va_end(ap);
219 }
220 
221 void
222 vtprintf(struct proc *p, int pri, const char *fmt, va_list ap)
223 {
224 	struct tty *tp = NULL;
225 	int flags = 0;
226 	struct putchar_arg pca;
227 	struct session *sess = NULL;
228 
229 	sx_slock(&proctree_lock);
230 	if (pri != -1)
231 		flags |= TOLOG;
232 	if (p != NULL) {
233 		PROC_LOCK(p);
234 		if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
235 			sess = p->p_session;
236 			sess_hold(sess);
237 			PROC_UNLOCK(p);
238 			tp = sess->s_ttyp;
239 			if (tp != NULL && tty_checkoutq(tp))
240 				flags |= TOTTY;
241 			else
242 				tp = NULL;
243 		} else
244 			PROC_UNLOCK(p);
245 	}
246 	pca.pri = pri;
247 	pca.tty = tp;
248 	pca.flags = flags;
249 	pca.p_bufr = NULL;
250 	if (pca.tty != NULL)
251 		tty_lock(pca.tty);
252 	sx_sunlock(&proctree_lock);
253 	kvprintf(fmt, putchar, &pca, 10, ap);
254 	if (pca.tty != NULL)
255 		tty_unlock(pca.tty);
256 	if (sess != NULL)
257 		sess_release(sess);
258 	msgbuftrigger = 1;
259 }
260 
261 static int
262 _vprintf(int level, int flags, const char *fmt, va_list ap)
263 {
264 	struct putchar_arg pca;
265 	int retval;
266 #ifdef PRINTF_BUFR_SIZE
267 	char bufr[PRINTF_BUFR_SIZE];
268 #endif
269 
270 	TSENTER();
271 	pca.tty = NULL;
272 	pca.pri = level;
273 	pca.flags = flags;
274 #ifdef PRINTF_BUFR_SIZE
275 	pca.p_bufr = bufr;
276 	pca.p_next = pca.p_bufr;
277 	pca.n_bufr = sizeof(bufr);
278 	pca.remain = sizeof(bufr);
279 	*pca.p_next = '\0';
280 #else
281 	/* Don't buffer console output. */
282 	pca.p_bufr = NULL;
283 #endif
284 
285 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
286 
287 #ifdef PRINTF_BUFR_SIZE
288 	/* Write any buffered console/log output: */
289 	if (*pca.p_bufr != '\0') {
290 		if (pca.flags & TOLOG)
291 			msglogstr(pca.p_bufr, level, /*filter_cr*/1);
292 
293 		if (pca.flags & TOCONS)
294 			cnputs(pca.p_bufr);
295 	}
296 #endif
297 
298 	TSEXIT();
299 	return (retval);
300 }
301 
302 /*
303  * Log writes to the log buffer, and guarantees not to sleep (so can be
304  * called by interrupt routines).  If there is no process reading the
305  * log yet, it writes to the console also.
306  */
307 void
308 log(int level, const char *fmt, ...)
309 {
310 	va_list ap;
311 
312 	va_start(ap, fmt);
313 	vlog(level, fmt, ap);
314 	va_end(ap);
315 }
316 
317 void
318 vlog(int level, const char *fmt, va_list ap)
319 {
320 
321 	(void)_vprintf(level, log_open ? TOLOG : TOCONS | TOLOG, fmt, ap);
322 	msgbuftrigger = 1;
323 }
324 
325 #define CONSCHUNK 128
326 
327 void
328 log_console(struct uio *uio)
329 {
330 	int c, error, nl;
331 	char *consbuffer;
332 	int pri;
333 
334 	if (!log_console_output)
335 		return;
336 
337 	pri = LOG_INFO | LOG_CONSOLE;
338 	uio = cloneuio(uio);
339 	consbuffer = malloc(CONSCHUNK, M_TEMP, M_WAITOK);
340 
341 	nl = 0;
342 	while (uio->uio_resid > 0) {
343 		c = imin(uio->uio_resid, CONSCHUNK - 1);
344 		error = uiomove(consbuffer, c, uio);
345 		if (error != 0)
346 			break;
347 		/* Make sure we're NUL-terminated */
348 		consbuffer[c] = '\0';
349 		if (consbuffer[c - 1] == '\n')
350 			nl = 1;
351 		else
352 			nl = 0;
353 		msglogstr(consbuffer, pri, /*filter_cr*/ 1);
354 	}
355 	/*
356 	 * The previous behavior in log_console() is preserved when
357 	 * log_console_add_linefeed is non-zero.  For that behavior, if an
358 	 * individual console write came in that was not terminated with a
359 	 * line feed, it would add a line feed.
360 	 *
361 	 * This results in different data in the message buffer than
362 	 * appears on the system console (which doesn't add extra line feed
363 	 * characters).
364 	 *
365 	 * A number of programs and rc scripts write a line feed, or a period
366 	 * and a line feed when they have completed their operation.  On
367 	 * the console, this looks seamless, but when displayed with
368 	 * 'dmesg -a', you wind up with output that looks like this:
369 	 *
370 	 * Updating motd:
371 	 * .
372 	 *
373 	 * On the console, it looks like this:
374 	 * Updating motd:.
375 	 *
376 	 * We could add logic to detect that situation, or just not insert
377 	 * the extra newlines.  Set the kern.log_console_add_linefeed
378 	 * sysctl/tunable variable to get the old behavior.
379 	 */
380 	if (!nl && log_console_add_linefeed) {
381 		consbuffer[0] = '\n';
382 		consbuffer[1] = '\0';
383 		msglogstr(consbuffer, pri, /*filter_cr*/ 1);
384 	}
385 	msgbuftrigger = 1;
386 	free(uio, M_IOV);
387 	free(consbuffer, M_TEMP);
388 }
389 
390 int
391 printf(const char *fmt, ...)
392 {
393 	va_list ap;
394 	int retval;
395 
396 	va_start(ap, fmt);
397 	retval = vprintf(fmt, ap);
398 	va_end(ap);
399 
400 	return (retval);
401 }
402 
403 int
404 vprintf(const char *fmt, va_list ap)
405 {
406 	int retval;
407 
408 	retval = _vprintf(-1, TOCONS | TOLOG, fmt, ap);
409 
410 	if (!panicstr)
411 		msgbuftrigger = 1;
412 
413 	return (retval);
414 }
415 
416 static void
417 prf_putbuf(char *bufr, int flags, int pri)
418 {
419 
420 	if (flags & TOLOG)
421 		msglogstr(bufr, pri, /*filter_cr*/1);
422 
423 	if (flags & TOCONS) {
424 		if ((panicstr == NULL) && (constty != NULL))
425 			msgbuf_addstr(&consmsgbuf, -1,
426 			    bufr, /*filter_cr*/ 0);
427 
428 		if ((constty == NULL) ||(always_console_output))
429 			cnputs(bufr);
430 	}
431 }
432 
433 static void
434 putbuf(int c, struct putchar_arg *ap)
435 {
436 	/* Check if no console output buffer was provided. */
437 	if (ap->p_bufr == NULL) {
438 		/* Output direct to the console. */
439 		if (ap->flags & TOCONS)
440 			cnputc(c);
441 
442 		if (ap->flags & TOLOG)
443 			msglogchar(c, ap->pri);
444 	} else {
445 		/* Buffer the character: */
446 		*ap->p_next++ = c;
447 		ap->remain--;
448 
449 		/* Always leave the buffer zero terminated. */
450 		*ap->p_next = '\0';
451 
452 		/* Check if the buffer needs to be flushed. */
453 		if (ap->remain == 2 || c == '\n') {
454 			prf_putbuf(ap->p_bufr, ap->flags, ap->pri);
455 
456 			ap->p_next = ap->p_bufr;
457 			ap->remain = ap->n_bufr;
458 			*ap->p_next = '\0';
459 		}
460 
461 		/*
462 		 * Since we fill the buffer up one character at a time,
463 		 * this should not happen.  We should always catch it when
464 		 * ap->remain == 2 (if not sooner due to a newline), flush
465 		 * the buffer and move on.  One way this could happen is
466 		 * if someone sets PRINTF_BUFR_SIZE to 1 or something
467 		 * similarly silly.
468 		 */
469 		KASSERT(ap->remain > 2, ("Bad buffer logic, remain = %zd",
470 		    ap->remain));
471 	}
472 }
473 
474 /*
475  * Print a character on console or users terminal.  If destination is
476  * the console then the last bunch of characters are saved in msgbuf for
477  * inspection later.
478  */
479 static void
480 putchar(int c, void *arg)
481 {
482 	struct putchar_arg *ap = (struct putchar_arg*) arg;
483 	struct tty *tp = ap->tty;
484 	int flags = ap->flags;
485 
486 	/* Don't use the tty code after a panic or while in ddb. */
487 	if (kdb_active) {
488 		if (c != '\0')
489 			cnputc(c);
490 		return;
491 	}
492 
493 	if ((flags & TOTTY) && tp != NULL && panicstr == NULL)
494 		tty_putchar(tp, c);
495 
496 	if ((flags & (TOCONS | TOLOG)) && c != '\0')
497 		putbuf(c, ap);
498 }
499 
500 /*
501  * Scaled down version of sprintf(3).
502  */
503 int
504 sprintf(char *buf, const char *cfmt, ...)
505 {
506 	int retval;
507 	va_list ap;
508 
509 	va_start(ap, cfmt);
510 	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
511 	buf[retval] = '\0';
512 	va_end(ap);
513 	return (retval);
514 }
515 
516 /*
517  * Scaled down version of vsprintf(3).
518  */
519 int
520 vsprintf(char *buf, const char *cfmt, va_list ap)
521 {
522 	int retval;
523 
524 	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
525 	buf[retval] = '\0';
526 	return (retval);
527 }
528 
529 /*
530  * Scaled down version of snprintf(3).
531  */
532 int
533 snprintf(char *str, size_t size, const char *format, ...)
534 {
535 	int retval;
536 	va_list ap;
537 
538 	va_start(ap, format);
539 	retval = vsnprintf(str, size, format, ap);
540 	va_end(ap);
541 	return(retval);
542 }
543 
544 /*
545  * Scaled down version of vsnprintf(3).
546  */
547 int
548 vsnprintf(char *str, size_t size, const char *format, va_list ap)
549 {
550 	struct snprintf_arg info;
551 	int retval;
552 
553 	info.str = str;
554 	info.remain = size;
555 	retval = kvprintf(format, snprintf_func, &info, 10, ap);
556 	if (info.remain >= 1)
557 		*info.str++ = '\0';
558 	return (retval);
559 }
560 
561 /*
562  * Kernel version which takes radix argument vsnprintf(3).
563  */
564 int
565 vsnrprintf(char *str, size_t size, int radix, const char *format, va_list ap)
566 {
567 	struct snprintf_arg info;
568 	int retval;
569 
570 	info.str = str;
571 	info.remain = size;
572 	retval = kvprintf(format, snprintf_func, &info, radix, ap);
573 	if (info.remain >= 1)
574 		*info.str++ = '\0';
575 	return (retval);
576 }
577 
578 static void
579 snprintf_func(int ch, void *arg)
580 {
581 	struct snprintf_arg *const info = arg;
582 
583 	if (info->remain >= 2) {
584 		*info->str++ = ch;
585 		info->remain--;
586 	}
587 }
588 
589 /*
590  * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
591  * order; return an optional length and a pointer to the last character
592  * written in the buffer (i.e., the first character of the string).
593  * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
594  */
595 static char *
596 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
597 {
598 	char *p, c;
599 
600 	p = nbuf;
601 	*p = '\0';
602 	do {
603 		c = hex2ascii(num % base);
604 		*++p = upper ? toupper(c) : c;
605 	} while (num /= base);
606 	if (lenp)
607 		*lenp = p - nbuf;
608 	return (p);
609 }
610 
611 /*
612  * Scaled down version of printf(3).
613  *
614  * Two additional formats:
615  *
616  * The format %b is supported to decode error registers.
617  * Its usage is:
618  *
619  *	printf("reg=%b\n", regval, "<base><arg>*");
620  *
621  * where <base> is the output base expressed as a control character, e.g.
622  * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
623  * the first of which gives the bit number to be inspected (origin 1), and
624  * the next characters (up to a control character, i.e. a character <= 32),
625  * give the name of the register.  Thus:
626  *
627  *	kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE");
628  *
629  * would produce output:
630  *
631  *	reg=3<BITTWO,BITONE>
632  *
633  * XXX:  %D  -- Hexdump, takes pointer and separator string:
634  *		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
635  *		("%*D", len, ptr, " " -> XX XX XX XX ...
636  */
637 int
638 kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap)
639 {
640 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; }
641 	char nbuf[MAXNBUF];
642 	char *d;
643 	const char *p, *percent, *q;
644 	u_char *up;
645 	int ch, n;
646 	uintmax_t num;
647 	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
648 	int cflag, hflag, jflag, tflag, zflag;
649 	int bconv, dwidth, upper;
650 	char padc;
651 	int stop = 0, retval = 0;
652 
653 	num = 0;
654 	q = NULL;
655 	if (!func)
656 		d = (char *) arg;
657 	else
658 		d = NULL;
659 
660 	if (fmt == NULL)
661 		fmt = "(fmt null)\n";
662 
663 	if (radix < 2 || radix > 36)
664 		radix = 10;
665 
666 	for (;;) {
667 		padc = ' ';
668 		width = 0;
669 		while ((ch = (u_char)*fmt++) != '%' || stop) {
670 			if (ch == '\0')
671 				return (retval);
672 			PCHAR(ch);
673 		}
674 		percent = fmt - 1;
675 		qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
676 		sign = 0; dot = 0; bconv = 0; dwidth = 0; upper = 0;
677 		cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
678 reswitch:	switch (ch = (u_char)*fmt++) {
679 		case '.':
680 			dot = 1;
681 			goto reswitch;
682 		case '#':
683 			sharpflag = 1;
684 			goto reswitch;
685 		case '+':
686 			sign = 1;
687 			goto reswitch;
688 		case '-':
689 			ladjust = 1;
690 			goto reswitch;
691 		case '%':
692 			PCHAR(ch);
693 			break;
694 		case '*':
695 			if (!dot) {
696 				width = va_arg(ap, int);
697 				if (width < 0) {
698 					ladjust = !ladjust;
699 					width = -width;
700 				}
701 			} else {
702 				dwidth = va_arg(ap, int);
703 			}
704 			goto reswitch;
705 		case '0':
706 			if (!dot) {
707 				padc = '0';
708 				goto reswitch;
709 			}
710 			/* FALLTHROUGH */
711 		case '1': case '2': case '3': case '4':
712 		case '5': case '6': case '7': case '8': case '9':
713 				for (n = 0;; ++fmt) {
714 					n = n * 10 + ch - '0';
715 					ch = *fmt;
716 					if (ch < '0' || ch > '9')
717 						break;
718 				}
719 			if (dot)
720 				dwidth = n;
721 			else
722 				width = n;
723 			goto reswitch;
724 		case 'b':
725 			ladjust = 1;
726 			bconv = 1;
727 			goto handle_nosign;
728 		case 'c':
729 			width -= 1;
730 
731 			if (!ladjust && width > 0)
732 				while (width--)
733 					PCHAR(padc);
734 			PCHAR(va_arg(ap, int));
735 			if (ladjust && width > 0)
736 				while (width--)
737 					PCHAR(padc);
738 			break;
739 		case 'D':
740 			up = va_arg(ap, u_char *);
741 			p = va_arg(ap, char *);
742 			if (!width)
743 				width = 16;
744 			while(width--) {
745 				PCHAR(hex2ascii(*up >> 4));
746 				PCHAR(hex2ascii(*up & 0x0f));
747 				up++;
748 				if (width)
749 					for (q=p;*q;q++)
750 						PCHAR(*q);
751 			}
752 			break;
753 		case 'd':
754 		case 'i':
755 			base = 10;
756 			sign = 1;
757 			goto handle_sign;
758 		case 'h':
759 			if (hflag) {
760 				hflag = 0;
761 				cflag = 1;
762 			} else
763 				hflag = 1;
764 			goto reswitch;
765 		case 'j':
766 			jflag = 1;
767 			goto reswitch;
768 		case 'l':
769 			if (lflag) {
770 				lflag = 0;
771 				qflag = 1;
772 			} else
773 				lflag = 1;
774 			goto reswitch;
775 		case 'n':
776 			if (jflag)
777 				*(va_arg(ap, intmax_t *)) = retval;
778 			else if (qflag)
779 				*(va_arg(ap, quad_t *)) = retval;
780 			else if (lflag)
781 				*(va_arg(ap, long *)) = retval;
782 			else if (zflag)
783 				*(va_arg(ap, size_t *)) = retval;
784 			else if (hflag)
785 				*(va_arg(ap, short *)) = retval;
786 			else if (cflag)
787 				*(va_arg(ap, char *)) = retval;
788 			else
789 				*(va_arg(ap, int *)) = retval;
790 			break;
791 		case 'o':
792 			base = 8;
793 			goto handle_nosign;
794 		case 'p':
795 			base = 16;
796 			sharpflag = (width == 0);
797 			sign = 0;
798 			num = (uintptr_t)va_arg(ap, void *);
799 			goto number;
800 		case 'q':
801 			qflag = 1;
802 			goto reswitch;
803 		case 'r':
804 			base = radix;
805 			if (sign)
806 				goto handle_sign;
807 			goto handle_nosign;
808 		case 's':
809 			p = va_arg(ap, char *);
810 			if (p == NULL)
811 				p = "(null)";
812 			if (!dot)
813 				n = strlen (p);
814 			else
815 				for (n = 0; n < dwidth && p[n]; n++)
816 					continue;
817 
818 			width -= n;
819 
820 			if (!ladjust && width > 0)
821 				while (width--)
822 					PCHAR(padc);
823 			while (n--)
824 				PCHAR(*p++);
825 			if (ladjust && width > 0)
826 				while (width--)
827 					PCHAR(padc);
828 			break;
829 		case 't':
830 			tflag = 1;
831 			goto reswitch;
832 		case 'u':
833 			base = 10;
834 			goto handle_nosign;
835 		case 'X':
836 			upper = 1;
837 		case 'x':
838 			base = 16;
839 			goto handle_nosign;
840 		case 'y':
841 			base = 16;
842 			sign = 1;
843 			goto handle_sign;
844 		case 'z':
845 			zflag = 1;
846 			goto reswitch;
847 handle_nosign:
848 			sign = 0;
849 			if (jflag)
850 				num = va_arg(ap, uintmax_t);
851 			else if (qflag)
852 				num = va_arg(ap, u_quad_t);
853 			else if (tflag)
854 				num = va_arg(ap, ptrdiff_t);
855 			else if (lflag)
856 				num = va_arg(ap, u_long);
857 			else if (zflag)
858 				num = va_arg(ap, size_t);
859 			else if (hflag)
860 				num = (u_short)va_arg(ap, int);
861 			else if (cflag)
862 				num = (u_char)va_arg(ap, int);
863 			else
864 				num = va_arg(ap, u_int);
865 			if (bconv) {
866 				q = va_arg(ap, char *);
867 				base = *q++;
868 			}
869 			goto number;
870 handle_sign:
871 			if (jflag)
872 				num = va_arg(ap, intmax_t);
873 			else if (qflag)
874 				num = va_arg(ap, quad_t);
875 			else if (tflag)
876 				num = va_arg(ap, ptrdiff_t);
877 			else if (lflag)
878 				num = va_arg(ap, long);
879 			else if (zflag)
880 				num = va_arg(ap, ssize_t);
881 			else if (hflag)
882 				num = (short)va_arg(ap, int);
883 			else if (cflag)
884 				num = (char)va_arg(ap, int);
885 			else
886 				num = va_arg(ap, int);
887 number:
888 			if (sign && (intmax_t)num < 0) {
889 				neg = 1;
890 				num = -(intmax_t)num;
891 			}
892 			p = ksprintn(nbuf, num, base, &n, upper);
893 			tmp = 0;
894 			if (sharpflag && num != 0) {
895 				if (base == 8)
896 					tmp++;
897 				else if (base == 16)
898 					tmp += 2;
899 			}
900 			if (neg)
901 				tmp++;
902 
903 			if (!ladjust && padc == '0')
904 				dwidth = width - tmp;
905 			width -= tmp + imax(dwidth, n);
906 			dwidth -= n;
907 			if (!ladjust)
908 				while (width-- > 0)
909 					PCHAR(' ');
910 			if (neg)
911 				PCHAR('-');
912 			if (sharpflag && num != 0) {
913 				if (base == 8) {
914 					PCHAR('0');
915 				} else if (base == 16) {
916 					PCHAR('0');
917 					PCHAR('x');
918 				}
919 			}
920 			while (dwidth-- > 0)
921 				PCHAR('0');
922 
923 			while (*p)
924 				PCHAR(*p--);
925 
926 			if (bconv && num != 0) {
927 				/* %b conversion flag format. */
928 				tmp = retval;
929 				while (*q) {
930 					n = *q++;
931 					if (num & (1 << (n - 1))) {
932 						PCHAR(retval != tmp ?
933 						    ',' : '<');
934 						for (; (n = *q) > ' '; ++q)
935 							PCHAR(n);
936 					} else
937 						for (; *q > ' '; ++q)
938 							continue;
939 				}
940 				if (retval != tmp) {
941 					PCHAR('>');
942 					width -= retval - tmp;
943 				}
944 			}
945 
946 			if (ladjust)
947 				while (width-- > 0)
948 					PCHAR(' ');
949 
950 			break;
951 		default:
952 			while (percent < fmt)
953 				PCHAR(*percent++);
954 			/*
955 			 * Since we ignore a formatting argument it is no
956 			 * longer safe to obey the remaining formatting
957 			 * arguments as the arguments will no longer match
958 			 * the format specs.
959 			 */
960 			stop = 1;
961 			break;
962 		}
963 	}
964 #undef PCHAR
965 }
966 
967 /*
968  * Put character in log buffer with a particular priority.
969  */
970 static void
971 msglogchar(int c, int pri)
972 {
973 	static int lastpri = -1;
974 	static int dangling;
975 	char nbuf[MAXNBUF];
976 	char *p;
977 
978 	if (!msgbufmapped)
979 		return;
980 	if (c == '\0' || c == '\r')
981 		return;
982 	if (pri != -1 && pri != lastpri) {
983 		if (dangling) {
984 			msgbuf_addchar(msgbufp, '\n');
985 			dangling = 0;
986 		}
987 		msgbuf_addchar(msgbufp, '<');
988 		for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL, 0); *p;)
989 			msgbuf_addchar(msgbufp, *p--);
990 		msgbuf_addchar(msgbufp, '>');
991 		lastpri = pri;
992 	}
993 	msgbuf_addchar(msgbufp, c);
994 	if (c == '\n') {
995 		dangling = 0;
996 		lastpri = -1;
997 	} else {
998 		dangling = 1;
999 	}
1000 }
1001 
1002 static void
1003 msglogstr(char *str, int pri, int filter_cr)
1004 {
1005 	if (!msgbufmapped)
1006 		return;
1007 
1008 	msgbuf_addstr(msgbufp, pri, str, filter_cr);
1009 }
1010 
1011 void
1012 msgbufinit(void *ptr, int size)
1013 {
1014 	char *cp;
1015 	static struct msgbuf *oldp = NULL;
1016 	bool print_boot_tag;
1017 
1018 	size -= sizeof(*msgbufp);
1019 	cp = (char *)ptr;
1020 	print_boot_tag = !msgbufmapped;
1021 	/* Attempt to fetch kern.boot_tag tunable on first mapping */
1022 	if (!msgbufmapped)
1023 		TUNABLE_STR_FETCH("kern.boot_tag", current_boot_tag,
1024 		    sizeof(current_boot_tag));
1025 	msgbufp = (struct msgbuf *)(cp + size);
1026 	msgbuf_reinit(msgbufp, cp, size);
1027 	if (msgbufmapped && oldp != msgbufp)
1028 		msgbuf_copy(oldp, msgbufp);
1029 	msgbufmapped = true;
1030 	if (print_boot_tag && *current_boot_tag != '\0')
1031 		printf("%s\n", current_boot_tag);
1032 	oldp = msgbufp;
1033 }
1034 
1035 /* Sysctls for accessing/clearing the msgbuf */
1036 static int
1037 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
1038 {
1039 	char buf[128];
1040 	u_int seq;
1041 	int error, len;
1042 
1043 	error = priv_check(req->td, PRIV_MSGBUF);
1044 	if (error)
1045 		return (error);
1046 
1047 	/* Read the whole buffer, one chunk at a time. */
1048 	mtx_lock(&msgbuf_lock);
1049 	msgbuf_peekbytes(msgbufp, NULL, 0, &seq);
1050 	for (;;) {
1051 		len = msgbuf_peekbytes(msgbufp, buf, sizeof(buf), &seq);
1052 		mtx_unlock(&msgbuf_lock);
1053 		if (len == 0)
1054 			return (SYSCTL_OUT(req, "", 1)); /* add nulterm */
1055 
1056 		error = sysctl_handle_opaque(oidp, buf, len, req);
1057 		if (error)
1058 			return (error);
1059 
1060 		mtx_lock(&msgbuf_lock);
1061 	}
1062 }
1063 
1064 SYSCTL_PROC(_kern, OID_AUTO, msgbuf,
1065     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
1066     NULL, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
1067 
1068 static int msgbuf_clearflag;
1069 
1070 static int
1071 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
1072 {
1073 	int error;
1074 	error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
1075 	if (!error && req->newptr) {
1076 		mtx_lock(&msgbuf_lock);
1077 		msgbuf_clear(msgbufp);
1078 		mtx_unlock(&msgbuf_lock);
1079 		msgbuf_clearflag = 0;
1080 	}
1081 	return (error);
1082 }
1083 
1084 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
1085     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE | CTLFLAG_MPSAFE,
1086     &msgbuf_clearflag, 0, sysctl_kern_msgbuf_clear, "I",
1087     "Clear kernel message buffer");
1088 
1089 #ifdef DDB
1090 
1091 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
1092 {
1093 	int i, j;
1094 
1095 	if (!msgbufmapped) {
1096 		db_printf("msgbuf not mapped yet\n");
1097 		return;
1098 	}
1099 	db_printf("msgbufp = %p\n", msgbufp);
1100 	db_printf("magic = %x, size = %d, r= %u, w = %u, ptr = %p, cksum= %u\n",
1101 	    msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_rseq,
1102 	    msgbufp->msg_wseq, msgbufp->msg_ptr, msgbufp->msg_cksum);
1103 	for (i = 0; i < msgbufp->msg_size && !db_pager_quit; i++) {
1104 		j = MSGBUF_SEQ_TO_POS(msgbufp, i + msgbufp->msg_rseq);
1105 		db_printf("%c", msgbufp->msg_ptr[j]);
1106 	}
1107 	db_printf("\n");
1108 }
1109 
1110 #endif /* DDB */
1111 
1112 void
1113 hexdump(const void *ptr, int length, const char *hdr, int flags)
1114 {
1115 	int i, j, k;
1116 	int cols;
1117 	const unsigned char *cp;
1118 	char delim;
1119 
1120 	if ((flags & HD_DELIM_MASK) != 0)
1121 		delim = (flags & HD_DELIM_MASK) >> 8;
1122 	else
1123 		delim = ' ';
1124 
1125 	if ((flags & HD_COLUMN_MASK) != 0)
1126 		cols = flags & HD_COLUMN_MASK;
1127 	else
1128 		cols = 16;
1129 
1130 	cp = ptr;
1131 	for (i = 0; i < length; i+= cols) {
1132 		if (hdr != NULL)
1133 			printf("%s", hdr);
1134 
1135 		if ((flags & HD_OMIT_COUNT) == 0)
1136 			printf("%04x  ", i);
1137 
1138 		if ((flags & HD_OMIT_HEX) == 0) {
1139 			for (j = 0; j < cols; j++) {
1140 				k = i + j;
1141 				if (k < length)
1142 					printf("%c%02x", delim, cp[k]);
1143 				else
1144 					printf("   ");
1145 			}
1146 		}
1147 
1148 		if ((flags & HD_OMIT_CHARS) == 0) {
1149 			printf("  |");
1150 			for (j = 0; j < cols; j++) {
1151 				k = i + j;
1152 				if (k >= length)
1153 					printf(" ");
1154 				else if (cp[k] >= ' ' && cp[k] <= '~')
1155 					printf("%c", cp[k]);
1156 				else
1157 					printf(".");
1158 			}
1159 			printf("|");
1160 		}
1161 		printf("\n");
1162 	}
1163 }
1164 #endif /* _KERNEL */
1165 
1166 void
1167 sbuf_hexdump(struct sbuf *sb, const void *ptr, int length, const char *hdr,
1168 	     int flags)
1169 {
1170 	int i, j, k;
1171 	int cols;
1172 	const unsigned char *cp;
1173 	char delim;
1174 
1175 	if ((flags & HD_DELIM_MASK) != 0)
1176 		delim = (flags & HD_DELIM_MASK) >> 8;
1177 	else
1178 		delim = ' ';
1179 
1180 	if ((flags & HD_COLUMN_MASK) != 0)
1181 		cols = flags & HD_COLUMN_MASK;
1182 	else
1183 		cols = 16;
1184 
1185 	cp = ptr;
1186 	for (i = 0; i < length; i+= cols) {
1187 		if (hdr != NULL)
1188 			sbuf_printf(sb, "%s", hdr);
1189 
1190 		if ((flags & HD_OMIT_COUNT) == 0)
1191 			sbuf_printf(sb, "%04x  ", i);
1192 
1193 		if ((flags & HD_OMIT_HEX) == 0) {
1194 			for (j = 0; j < cols; j++) {
1195 				k = i + j;
1196 				if (k < length)
1197 					sbuf_printf(sb, "%c%02x", delim, cp[k]);
1198 				else
1199 					sbuf_printf(sb, "   ");
1200 			}
1201 		}
1202 
1203 		if ((flags & HD_OMIT_CHARS) == 0) {
1204 			sbuf_printf(sb, "  |");
1205 			for (j = 0; j < cols; j++) {
1206 				k = i + j;
1207 				if (k >= length)
1208 					sbuf_printf(sb, " ");
1209 				else if (cp[k] >= ' ' && cp[k] <= '~')
1210 					sbuf_printf(sb, "%c", cp[k]);
1211 				else
1212 					sbuf_printf(sb, ".");
1213 			}
1214 			sbuf_printf(sb, "|");
1215 		}
1216 		sbuf_printf(sb, "\n");
1217 	}
1218 }
1219 
1220 #ifdef _KERNEL
1221 void
1222 counted_warning(unsigned *counter, const char *msg)
1223 {
1224 	struct thread *td;
1225 	unsigned c;
1226 
1227 	for (;;) {
1228 		c = *counter;
1229 		if (c == 0)
1230 			break;
1231 		if (atomic_cmpset_int(counter, c, c - 1)) {
1232 			td = curthread;
1233 			log(LOG_INFO, "pid %d (%s) %s%s\n",
1234 			    td->td_proc->p_pid, td->td_name, msg,
1235 			    c > 1 ? "" : " - not logging anymore");
1236 			break;
1237 		}
1238 	}
1239 }
1240 #endif
1241 
1242 #ifdef _KERNEL
1243 void
1244 sbuf_putbuf(struct sbuf *sb)
1245 {
1246 
1247 	prf_putbuf(sbuf_data(sb), TOLOG | TOCONS, -1);
1248 }
1249 #else
1250 void
1251 sbuf_putbuf(struct sbuf *sb)
1252 {
1253 
1254 	printf("%s", sbuf_data(sb));
1255 }
1256 #endif
1257