xref: /freebsd/sys/kern/subr_prf.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
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 #include "opt_printf.h"
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/lock.h>
46 #include <sys/kdb.h>
47 #include <sys/mutex.h>
48 #include <sys/sx.h>
49 #include <sys/kernel.h>
50 #include <sys/msgbuf.h>
51 #include <sys/malloc.h>
52 #include <sys/priv.h>
53 #include <sys/proc.h>
54 #include <sys/stddef.h>
55 #include <sys/sysctl.h>
56 #include <sys/tty.h>
57 #include <sys/syslog.h>
58 #include <sys/cons.h>
59 #include <sys/uio.h>
60 #include <sys/ctype.h>
61 
62 #ifdef DDB
63 #include <ddb/ddb.h>
64 #endif
65 
66 /*
67  * Note that stdarg.h and the ANSI style va_start macro is used for both
68  * ANSI and traditional C compilers.
69  */
70 #include <machine/stdarg.h>
71 
72 #define TOCONS	0x01
73 #define TOTTY	0x02
74 #define TOLOG	0x04
75 
76 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
77 #define MAXNBUF	(sizeof(intmax_t) * NBBY + 1)
78 
79 struct putchar_arg {
80 	int	flags;
81 	int	pri;
82 	struct	tty *tty;
83 	char	*p_bufr;
84 	size_t	n_bufr;
85 	char	*p_next;
86 	size_t	remain;
87 };
88 
89 struct snprintf_arg {
90 	char	*str;
91 	size_t	remain;
92 };
93 
94 extern	int log_open;
95 
96 static void  msglogchar(int c, int pri);
97 static void  msglogstr(char *str, int pri, int filter_cr);
98 static void  putchar(int ch, void *arg);
99 static char *ksprintn(char *nbuf, uintmax_t num, int base, int *len, int upper);
100 static void  snprintf_func(int ch, void *arg);
101 
102 static int msgbufmapped;		/* Set when safe to use msgbuf */
103 int msgbuftrigger;
104 
105 static int      log_console_output = 1;
106 TUNABLE_INT("kern.log_console_output", &log_console_output);
107 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW,
108     &log_console_output, 0, "Duplicate console output to the syslog.");
109 
110 /*
111  * See the comment in log_console() below for more explanation of this.
112  */
113 static int log_console_add_linefeed = 0;
114 TUNABLE_INT("kern.log_console_add_linefeed", &log_console_add_linefeed);
115 SYSCTL_INT(_kern, OID_AUTO, log_console_add_linefeed, CTLFLAG_RW,
116     &log_console_add_linefeed, 0, "log_console() adds extra newlines.");
117 
118 static int	always_console_output = 0;
119 TUNABLE_INT("kern.always_console_output", &always_console_output);
120 SYSCTL_INT(_kern, OID_AUTO, always_console_output, CTLFLAG_RW,
121     &always_console_output, 0, "Always output to console despite TIOCCONS.");
122 
123 /*
124  * Warn that a system table is full.
125  */
126 void
127 tablefull(const char *tab)
128 {
129 
130 	log(LOG_ERR, "%s: table is full\n", tab);
131 }
132 
133 /*
134  * Uprintf prints to the controlling terminal for the current process.
135  */
136 int
137 uprintf(const char *fmt, ...)
138 {
139 	va_list ap;
140 	struct putchar_arg pca;
141 	struct proc *p;
142 	struct thread *td;
143 	int retval;
144 
145 	td = curthread;
146 	if (TD_IS_IDLETHREAD(td))
147 		return (0);
148 
149 	sx_slock(&proctree_lock);
150 	p = td->td_proc;
151 	PROC_LOCK(p);
152 	if ((p->p_flag & P_CONTROLT) == 0) {
153 		PROC_UNLOCK(p);
154 		retval = 0;
155 		goto out;
156 	}
157 	SESS_LOCK(p->p_session);
158 	pca.tty = p->p_session->s_ttyp;
159 	SESS_UNLOCK(p->p_session);
160 	PROC_UNLOCK(p);
161 	if (pca.tty == NULL) {
162 		retval = 0;
163 		goto out;
164 	}
165 	pca.flags = TOTTY;
166 	va_start(ap, fmt);
167 	tty_lock(pca.tty);
168 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
169 	tty_unlock(pca.tty);
170 	va_end(ap);
171 out:
172 	sx_sunlock(&proctree_lock);
173 	return (retval);
174 }
175 
176 /*
177  * tprintf prints on the controlling terminal associated with the given
178  * session, possibly to the log as well.
179  */
180 void
181 tprintf(struct proc *p, int pri, const char *fmt, ...)
182 {
183 	struct tty *tp = NULL;
184 	int flags = 0;
185 	va_list ap;
186 	struct putchar_arg pca;
187 	struct session *sess = NULL;
188 
189 	sx_slock(&proctree_lock);
190 	if (pri != -1)
191 		flags |= TOLOG;
192 	if (p != NULL) {
193 		PROC_LOCK(p);
194 		if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
195 			sess = p->p_session;
196 			sess_hold(sess);
197 			PROC_UNLOCK(p);
198 			tp = sess->s_ttyp;
199 			if (tp != NULL && tty_checkoutq(tp))
200 				flags |= TOTTY;
201 			else
202 				tp = NULL;
203 		} else
204 			PROC_UNLOCK(p);
205 	}
206 	pca.pri = pri;
207 	pca.tty = tp;
208 	pca.flags = flags;
209 	va_start(ap, fmt);
210 	if (pca.tty != NULL)
211 		tty_lock(pca.tty);
212 	kvprintf(fmt, putchar, &pca, 10, ap);
213 	if (pca.tty != NULL)
214 		tty_unlock(pca.tty);
215 	va_end(ap);
216 	if (sess != NULL)
217 		sess_release(sess);
218 	msgbuftrigger = 1;
219 	sx_sunlock(&proctree_lock);
220 }
221 
222 /*
223  * Ttyprintf displays a message on a tty; it should be used only by
224  * the tty driver, or anything that knows the underlying tty will not
225  * be revoke(2)'d away.  Other callers should use tprintf.
226  */
227 int
228 ttyprintf(struct tty *tp, const char *fmt, ...)
229 {
230 	va_list ap;
231 	struct putchar_arg pca;
232 	int retval;
233 
234 	va_start(ap, fmt);
235 	pca.tty = tp;
236 	pca.flags = TOTTY;
237 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
238 	va_end(ap);
239 	return (retval);
240 }
241 
242 /*
243  * Log writes to the log buffer, and guarantees not to sleep (so can be
244  * called by interrupt routines).  If there is no process reading the
245  * log yet, it writes to the console also.
246  */
247 void
248 log(int level, const char *fmt, ...)
249 {
250 	va_list ap;
251 	struct putchar_arg pca;
252 #ifdef PRINTF_BUFR_SIZE
253 	char bufr[PRINTF_BUFR_SIZE];
254 #endif
255 
256 	pca.tty = NULL;
257 	pca.pri = level;
258 	pca.flags = log_open ? TOLOG : TOCONS;
259 #ifdef PRINTF_BUFR_SIZE
260 	pca.p_bufr = bufr;
261 	pca.p_next = pca.p_bufr;
262 	pca.n_bufr = sizeof(bufr);
263 	pca.remain = sizeof(bufr);
264 	*pca.p_next = '\0';
265 #else
266 	pca.p_bufr = NULL;
267 #endif
268 
269 	va_start(ap, fmt);
270 	kvprintf(fmt, putchar, &pca, 10, ap);
271 	va_end(ap);
272 
273 #ifdef PRINTF_BUFR_SIZE
274 	/* Write any buffered console/log output: */
275 	if (*pca.p_bufr != '\0') {
276 		if (pca.flags & TOLOG)
277 			msglogstr(pca.p_bufr, level, /*filter_cr*/1);
278 
279 		if (pca.flags & TOCONS)
280 			cnputs(pca.p_bufr);
281 	}
282 #endif
283 	msgbuftrigger = 1;
284 }
285 
286 #define CONSCHUNK 128
287 
288 void
289 log_console(struct uio *uio)
290 {
291 	int c, error, nl;
292 	char *consbuffer;
293 	int pri;
294 
295 	if (!log_console_output)
296 		return;
297 
298 	pri = LOG_INFO | LOG_CONSOLE;
299 	uio = cloneuio(uio);
300 	consbuffer = malloc(CONSCHUNK, M_TEMP, M_WAITOK);
301 
302 	nl = 0;
303 	while (uio->uio_resid > 0) {
304 		c = imin(uio->uio_resid, CONSCHUNK - 1);
305 		error = uiomove(consbuffer, c, uio);
306 		if (error != 0)
307 			break;
308 		/* Make sure we're NUL-terminated */
309 		consbuffer[c] = '\0';
310 		if (consbuffer[c - 1] == '\n')
311 			nl = 1;
312 		else
313 			nl = 0;
314 		msglogstr(consbuffer, pri, /*filter_cr*/ 1);
315 	}
316 	/*
317 	 * The previous behavior in log_console() is preserved when
318 	 * log_console_add_linefeed is non-zero.  For that behavior, if an
319 	 * individual console write came in that was not terminated with a
320 	 * line feed, it would add a line feed.
321 	 *
322 	 * This results in different data in the message buffer than
323 	 * appears on the system console (which doesn't add extra line feed
324 	 * characters).
325 	 *
326 	 * A number of programs and rc scripts write a line feed, or a period
327 	 * and a line feed when they have completed their operation.  On
328 	 * the console, this looks seamless, but when displayed with
329 	 * 'dmesg -a', you wind up with output that looks like this:
330 	 *
331 	 * Updating motd:
332 	 * .
333 	 *
334 	 * On the console, it looks like this:
335 	 * Updating motd:.
336 	 *
337 	 * We could add logic to detect that situation, or just not insert
338 	 * the extra newlines.  Set the kern.log_console_add_linefeed
339 	 * sysctl/tunable variable to get the old behavior.
340 	 */
341 	if (!nl && log_console_add_linefeed) {
342 		consbuffer[0] = '\n';
343 		consbuffer[1] = '\0';
344 		msglogstr(consbuffer, pri, /*filter_cr*/ 1);
345 	}
346 	msgbuftrigger = 1;
347 	free(uio, M_IOV);
348 	free(consbuffer, M_TEMP);
349 	return;
350 }
351 
352 int
353 printf(const char *fmt, ...)
354 {
355 	va_list ap;
356 	int retval;
357 
358 	va_start(ap, fmt);
359 	retval = vprintf(fmt, ap);
360 	va_end(ap);
361 
362 	return (retval);
363 }
364 
365 int
366 vprintf(const char *fmt, va_list ap)
367 {
368 	struct putchar_arg pca;
369 	int retval;
370 #ifdef PRINTF_BUFR_SIZE
371 	char bufr[PRINTF_BUFR_SIZE];
372 #endif
373 
374 	pca.tty = NULL;
375 	pca.flags = TOCONS | TOLOG;
376 	pca.pri = -1;
377 #ifdef PRINTF_BUFR_SIZE
378 	pca.p_bufr = bufr;
379 	pca.p_next = pca.p_bufr;
380 	pca.n_bufr = sizeof(bufr);
381 	pca.remain = sizeof(bufr);
382 	*pca.p_next = '\0';
383 #else
384 	/* Don't buffer console output. */
385 	pca.p_bufr = NULL;
386 #endif
387 
388 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
389 
390 #ifdef PRINTF_BUFR_SIZE
391 	/* Write any buffered console/log output: */
392 	if (*pca.p_bufr != '\0') {
393 		cnputs(pca.p_bufr);
394 		msglogstr(pca.p_bufr, pca.pri, /*filter_cr*/ 1);
395 	}
396 #endif
397 
398 	if (!panicstr)
399 		msgbuftrigger = 1;
400 
401 	return (retval);
402 }
403 
404 static void
405 putbuf(int c, struct putchar_arg *ap)
406 {
407 	/* Check if no console output buffer was provided. */
408 	if (ap->p_bufr == NULL) {
409 		/* Output direct to the console. */
410 		if (ap->flags & TOCONS)
411 			cnputc(c);
412 
413 		if (ap->flags & TOLOG)
414 			msglogchar(c, ap->pri);
415 	} else {
416 		/* Buffer the character: */
417 		*ap->p_next++ = c;
418 		ap->remain--;
419 
420 		/* Always leave the buffer zero terminated. */
421 		*ap->p_next = '\0';
422 
423 		/* Check if the buffer needs to be flushed. */
424 		if (ap->remain == 2 || c == '\n') {
425 
426 			if (ap->flags & TOLOG)
427 				msglogstr(ap->p_bufr, ap->pri, /*filter_cr*/1);
428 
429 			if (ap->flags & TOCONS) {
430 				if ((panicstr == NULL) && (constty != NULL))
431 					msgbuf_addstr(&consmsgbuf, -1,
432 					    ap->p_bufr, /*filter_cr*/ 0);
433 
434 				if ((constty == NULL) ||(always_console_output))
435 					cnputs(ap->p_bufr);
436 			}
437 
438 			ap->p_next = ap->p_bufr;
439 			ap->remain = ap->n_bufr;
440 			*ap->p_next = '\0';
441 		}
442 
443 		/*
444 		 * Since we fill the buffer up one character at a time,
445 		 * this should not happen.  We should always catch it when
446 		 * ap->remain == 2 (if not sooner due to a newline), flush
447 		 * the buffer and move on.  One way this could happen is
448 		 * if someone sets PRINTF_BUFR_SIZE to 1 or something
449 		 * similarly silly.
450 		 */
451 		KASSERT(ap->remain > 2, ("Bad buffer logic, remain = %zd",
452 		    ap->remain));
453 	}
454 }
455 
456 /*
457  * Print a character on console or users terminal.  If destination is
458  * the console then the last bunch of characters are saved in msgbuf for
459  * inspection later.
460  */
461 static void
462 putchar(int c, void *arg)
463 {
464 	struct putchar_arg *ap = (struct putchar_arg*) arg;
465 	struct tty *tp = ap->tty;
466 	int flags = ap->flags;
467 	int putbuf_done = 0;
468 
469 	/* Don't use the tty code after a panic or while in ddb. */
470 	if (kdb_active) {
471 		if (c != '\0')
472 			cnputc(c);
473 	} else {
474 		if ((panicstr == NULL) && (flags & TOTTY) && (tp != NULL))
475 			tty_putchar(tp, c);
476 
477 		if (flags & TOCONS) {
478 			putbuf(c, ap);
479 			putbuf_done = 1;
480 		}
481 	}
482 	if ((flags & TOLOG) && (putbuf_done == 0)) {
483 		if (c != '\0')
484 			putbuf(c, ap);
485 	}
486 }
487 
488 /*
489  * Scaled down version of sprintf(3).
490  */
491 int
492 sprintf(char *buf, const char *cfmt, ...)
493 {
494 	int retval;
495 	va_list ap;
496 
497 	va_start(ap, cfmt);
498 	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
499 	buf[retval] = '\0';
500 	va_end(ap);
501 	return (retval);
502 }
503 
504 /*
505  * Scaled down version of vsprintf(3).
506  */
507 int
508 vsprintf(char *buf, const char *cfmt, va_list ap)
509 {
510 	int retval;
511 
512 	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
513 	buf[retval] = '\0';
514 	return (retval);
515 }
516 
517 /*
518  * Scaled down version of snprintf(3).
519  */
520 int
521 snprintf(char *str, size_t size, const char *format, ...)
522 {
523 	int retval;
524 	va_list ap;
525 
526 	va_start(ap, format);
527 	retval = vsnprintf(str, size, format, ap);
528 	va_end(ap);
529 	return(retval);
530 }
531 
532 /*
533  * Scaled down version of vsnprintf(3).
534  */
535 int
536 vsnprintf(char *str, size_t size, const char *format, va_list ap)
537 {
538 	struct snprintf_arg info;
539 	int retval;
540 
541 	info.str = str;
542 	info.remain = size;
543 	retval = kvprintf(format, snprintf_func, &info, 10, ap);
544 	if (info.remain >= 1)
545 		*info.str++ = '\0';
546 	return (retval);
547 }
548 
549 /*
550  * Kernel version which takes radix argument vsnprintf(3).
551  */
552 int
553 vsnrprintf(char *str, size_t size, int radix, const char *format, va_list ap)
554 {
555 	struct snprintf_arg info;
556 	int retval;
557 
558 	info.str = str;
559 	info.remain = size;
560 	retval = kvprintf(format, snprintf_func, &info, radix, ap);
561 	if (info.remain >= 1)
562 		*info.str++ = '\0';
563 	return (retval);
564 }
565 
566 static void
567 snprintf_func(int ch, void *arg)
568 {
569 	struct snprintf_arg *const info = arg;
570 
571 	if (info->remain >= 2) {
572 		*info->str++ = ch;
573 		info->remain--;
574 	}
575 }
576 
577 /*
578  * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
579  * order; return an optional length and a pointer to the last character
580  * written in the buffer (i.e., the first character of the string).
581  * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
582  */
583 static char *
584 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
585 {
586 	char *p, c;
587 
588 	p = nbuf;
589 	*p = '\0';
590 	do {
591 		c = hex2ascii(num % base);
592 		*++p = upper ? toupper(c) : c;
593 	} while (num /= base);
594 	if (lenp)
595 		*lenp = p - nbuf;
596 	return (p);
597 }
598 
599 /*
600  * Scaled down version of printf(3).
601  *
602  * Two additional formats:
603  *
604  * The format %b is supported to decode error registers.
605  * Its usage is:
606  *
607  *	printf("reg=%b\n", regval, "<base><arg>*");
608  *
609  * where <base> is the output base expressed as a control character, e.g.
610  * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
611  * the first of which gives the bit number to be inspected (origin 1), and
612  * the next characters (up to a control character, i.e. a character <= 32),
613  * give the name of the register.  Thus:
614  *
615  *	kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
616  *
617  * would produce output:
618  *
619  *	reg=3<BITTWO,BITONE>
620  *
621  * XXX:  %D  -- Hexdump, takes pointer and separator string:
622  *		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
623  *		("%*D", len, ptr, " " -> XX XX XX XX ...
624  */
625 int
626 kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap)
627 {
628 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; }
629 	char nbuf[MAXNBUF];
630 	char *d;
631 	const char *p, *percent, *q;
632 	u_char *up;
633 	int ch, n;
634 	uintmax_t num;
635 	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
636 	int cflag, hflag, jflag, tflag, zflag;
637 	int dwidth, upper;
638 	char padc;
639 	int stop = 0, retval = 0;
640 
641 	num = 0;
642 	if (!func)
643 		d = (char *) arg;
644 	else
645 		d = NULL;
646 
647 	if (fmt == NULL)
648 		fmt = "(fmt null)\n";
649 
650 	if (radix < 2 || radix > 36)
651 		radix = 10;
652 
653 	for (;;) {
654 		padc = ' ';
655 		width = 0;
656 		while ((ch = (u_char)*fmt++) != '%' || stop) {
657 			if (ch == '\0')
658 				return (retval);
659 			PCHAR(ch);
660 		}
661 		percent = fmt - 1;
662 		qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
663 		sign = 0; dot = 0; dwidth = 0; upper = 0;
664 		cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
665 reswitch:	switch (ch = (u_char)*fmt++) {
666 		case '.':
667 			dot = 1;
668 			goto reswitch;
669 		case '#':
670 			sharpflag = 1;
671 			goto reswitch;
672 		case '+':
673 			sign = 1;
674 			goto reswitch;
675 		case '-':
676 			ladjust = 1;
677 			goto reswitch;
678 		case '%':
679 			PCHAR(ch);
680 			break;
681 		case '*':
682 			if (!dot) {
683 				width = va_arg(ap, int);
684 				if (width < 0) {
685 					ladjust = !ladjust;
686 					width = -width;
687 				}
688 			} else {
689 				dwidth = va_arg(ap, int);
690 			}
691 			goto reswitch;
692 		case '0':
693 			if (!dot) {
694 				padc = '0';
695 				goto reswitch;
696 			}
697 		case '1': case '2': case '3': case '4':
698 		case '5': case '6': case '7': case '8': case '9':
699 				for (n = 0;; ++fmt) {
700 					n = n * 10 + ch - '0';
701 					ch = *fmt;
702 					if (ch < '0' || ch > '9')
703 						break;
704 				}
705 			if (dot)
706 				dwidth = n;
707 			else
708 				width = n;
709 			goto reswitch;
710 		case 'b':
711 			num = (u_int)va_arg(ap, int);
712 			p = va_arg(ap, char *);
713 			for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
714 				PCHAR(*q--);
715 
716 			if (num == 0)
717 				break;
718 
719 			for (tmp = 0; *p;) {
720 				n = *p++;
721 				if (num & (1 << (n - 1))) {
722 					PCHAR(tmp ? ',' : '<');
723 					for (; (n = *p) > ' '; ++p)
724 						PCHAR(n);
725 					tmp = 1;
726 				} else
727 					for (; *p > ' '; ++p)
728 						continue;
729 			}
730 			if (tmp)
731 				PCHAR('>');
732 			break;
733 		case 'c':
734 			PCHAR(va_arg(ap, int));
735 			break;
736 		case 'D':
737 			up = va_arg(ap, u_char *);
738 			p = va_arg(ap, char *);
739 			if (!width)
740 				width = 16;
741 			while(width--) {
742 				PCHAR(hex2ascii(*up >> 4));
743 				PCHAR(hex2ascii(*up & 0x0f));
744 				up++;
745 				if (width)
746 					for (q=p;*q;q++)
747 						PCHAR(*q);
748 			}
749 			break;
750 		case 'd':
751 		case 'i':
752 			base = 10;
753 			sign = 1;
754 			goto handle_sign;
755 		case 'h':
756 			if (hflag) {
757 				hflag = 0;
758 				cflag = 1;
759 			} else
760 				hflag = 1;
761 			goto reswitch;
762 		case 'j':
763 			jflag = 1;
764 			goto reswitch;
765 		case 'l':
766 			if (lflag) {
767 				lflag = 0;
768 				qflag = 1;
769 			} else
770 				lflag = 1;
771 			goto reswitch;
772 		case 'n':
773 			if (jflag)
774 				*(va_arg(ap, intmax_t *)) = retval;
775 			else if (qflag)
776 				*(va_arg(ap, quad_t *)) = retval;
777 			else if (lflag)
778 				*(va_arg(ap, long *)) = retval;
779 			else if (zflag)
780 				*(va_arg(ap, size_t *)) = retval;
781 			else if (hflag)
782 				*(va_arg(ap, short *)) = retval;
783 			else if (cflag)
784 				*(va_arg(ap, char *)) = retval;
785 			else
786 				*(va_arg(ap, int *)) = retval;
787 			break;
788 		case 'o':
789 			base = 8;
790 			goto handle_nosign;
791 		case 'p':
792 			base = 16;
793 			sharpflag = (width == 0);
794 			sign = 0;
795 			num = (uintptr_t)va_arg(ap, void *);
796 			goto number;
797 		case 'q':
798 			qflag = 1;
799 			goto reswitch;
800 		case 'r':
801 			base = radix;
802 			if (sign)
803 				goto handle_sign;
804 			goto handle_nosign;
805 		case 's':
806 			p = va_arg(ap, char *);
807 			if (p == NULL)
808 				p = "(null)";
809 			if (!dot)
810 				n = strlen (p);
811 			else
812 				for (n = 0; n < dwidth && p[n]; n++)
813 					continue;
814 
815 			width -= n;
816 
817 			if (!ladjust && width > 0)
818 				while (width--)
819 					PCHAR(padc);
820 			while (n--)
821 				PCHAR(*p++);
822 			if (ladjust && width > 0)
823 				while (width--)
824 					PCHAR(padc);
825 			break;
826 		case 't':
827 			tflag = 1;
828 			goto reswitch;
829 		case 'u':
830 			base = 10;
831 			goto handle_nosign;
832 		case 'X':
833 			upper = 1;
834 		case 'x':
835 			base = 16;
836 			goto handle_nosign;
837 		case 'y':
838 			base = 16;
839 			sign = 1;
840 			goto handle_sign;
841 		case 'z':
842 			zflag = 1;
843 			goto reswitch;
844 handle_nosign:
845 			sign = 0;
846 			if (jflag)
847 				num = va_arg(ap, uintmax_t);
848 			else if (qflag)
849 				num = va_arg(ap, u_quad_t);
850 			else if (tflag)
851 				num = va_arg(ap, ptrdiff_t);
852 			else if (lflag)
853 				num = va_arg(ap, u_long);
854 			else if (zflag)
855 				num = va_arg(ap, size_t);
856 			else if (hflag)
857 				num = (u_short)va_arg(ap, int);
858 			else if (cflag)
859 				num = (u_char)va_arg(ap, int);
860 			else
861 				num = va_arg(ap, u_int);
862 			goto number;
863 handle_sign:
864 			if (jflag)
865 				num = va_arg(ap, intmax_t);
866 			else if (qflag)
867 				num = va_arg(ap, quad_t);
868 			else if (tflag)
869 				num = va_arg(ap, ptrdiff_t);
870 			else if (lflag)
871 				num = va_arg(ap, long);
872 			else if (zflag)
873 				num = va_arg(ap, ssize_t);
874 			else if (hflag)
875 				num = (short)va_arg(ap, int);
876 			else if (cflag)
877 				num = (char)va_arg(ap, int);
878 			else
879 				num = va_arg(ap, int);
880 number:
881 			if (sign && (intmax_t)num < 0) {
882 				neg = 1;
883 				num = -(intmax_t)num;
884 			}
885 			p = ksprintn(nbuf, num, base, &n, upper);
886 			tmp = 0;
887 			if (sharpflag && num != 0) {
888 				if (base == 8)
889 					tmp++;
890 				else if (base == 16)
891 					tmp += 2;
892 			}
893 			if (neg)
894 				tmp++;
895 
896 			if (!ladjust && padc == '0')
897 				dwidth = width - tmp;
898 			width -= tmp + imax(dwidth, n);
899 			dwidth -= n;
900 			if (!ladjust)
901 				while (width-- > 0)
902 					PCHAR(' ');
903 			if (neg)
904 				PCHAR('-');
905 			if (sharpflag && num != 0) {
906 				if (base == 8) {
907 					PCHAR('0');
908 				} else if (base == 16) {
909 					PCHAR('0');
910 					PCHAR('x');
911 				}
912 			}
913 			while (dwidth-- > 0)
914 				PCHAR('0');
915 
916 			while (*p)
917 				PCHAR(*p--);
918 
919 			if (ladjust)
920 				while (width-- > 0)
921 					PCHAR(' ');
922 
923 			break;
924 		default:
925 			while (percent < fmt)
926 				PCHAR(*percent++);
927 			/*
928 			 * Since we ignore an formatting argument it is no
929 			 * longer safe to obey the remaining formatting
930 			 * arguments as the arguments will no longer match
931 			 * the format specs.
932 			 */
933 			stop = 1;
934 			break;
935 		}
936 	}
937 #undef PCHAR
938 }
939 
940 /*
941  * Put character in log buffer with a particular priority.
942  */
943 static void
944 msglogchar(int c, int pri)
945 {
946 	static int lastpri = -1;
947 	static int dangling;
948 	char nbuf[MAXNBUF];
949 	char *p;
950 
951 	if (!msgbufmapped)
952 		return;
953 	if (c == '\0' || c == '\r')
954 		return;
955 	if (pri != -1 && pri != lastpri) {
956 		if (dangling) {
957 			msgbuf_addchar(msgbufp, '\n');
958 			dangling = 0;
959 		}
960 		msgbuf_addchar(msgbufp, '<');
961 		for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL, 0); *p;)
962 			msgbuf_addchar(msgbufp, *p--);
963 		msgbuf_addchar(msgbufp, '>');
964 		lastpri = pri;
965 	}
966 	msgbuf_addchar(msgbufp, c);
967 	if (c == '\n') {
968 		dangling = 0;
969 		lastpri = -1;
970 	} else {
971 		dangling = 1;
972 	}
973 }
974 
975 static void
976 msglogstr(char *str, int pri, int filter_cr)
977 {
978 	if (!msgbufmapped)
979 		return;
980 
981 	msgbuf_addstr(msgbufp, pri, str, filter_cr);
982 }
983 
984 void
985 msgbufinit(void *ptr, int size)
986 {
987 	char *cp;
988 	static struct msgbuf *oldp = NULL;
989 
990 	size -= sizeof(*msgbufp);
991 	cp = (char *)ptr;
992 	msgbufp = (struct msgbuf *)(cp + size);
993 	msgbuf_reinit(msgbufp, cp, size);
994 	if (msgbufmapped && oldp != msgbufp)
995 		msgbuf_copy(oldp, msgbufp);
996 	msgbufmapped = 1;
997 	oldp = msgbufp;
998 }
999 
1000 static int unprivileged_read_msgbuf = 1;
1001 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_read_msgbuf,
1002     CTLFLAG_RW, &unprivileged_read_msgbuf, 0,
1003     "Unprivileged processes may read the kernel message buffer");
1004 
1005 /* Sysctls for accessing/clearing the msgbuf */
1006 static int
1007 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
1008 {
1009 	char buf[128];
1010 	u_int seq;
1011 	int error, len;
1012 
1013 	if (!unprivileged_read_msgbuf) {
1014 		error = priv_check(req->td, PRIV_MSGBUF);
1015 		if (error)
1016 			return (error);
1017 	}
1018 
1019 	/* Read the whole buffer, one chunk at a time. */
1020 	mtx_lock(&msgbuf_lock);
1021 	msgbuf_peekbytes(msgbufp, NULL, 0, &seq);
1022 	for (;;) {
1023 		len = msgbuf_peekbytes(msgbufp, buf, sizeof(buf), &seq);
1024 		mtx_unlock(&msgbuf_lock);
1025 		if (len == 0)
1026 			return (0);
1027 
1028 		error = sysctl_handle_opaque(oidp, buf, len, req);
1029 		if (error)
1030 			return (error);
1031 
1032 		mtx_lock(&msgbuf_lock);
1033 	}
1034 }
1035 
1036 SYSCTL_PROC(_kern, OID_AUTO, msgbuf,
1037     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
1038     NULL, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
1039 
1040 static int msgbuf_clearflag;
1041 
1042 static int
1043 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
1044 {
1045 	int error;
1046 	error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
1047 	if (!error && req->newptr) {
1048 		mtx_lock(&msgbuf_lock);
1049 		msgbuf_clear(msgbufp);
1050 		mtx_unlock(&msgbuf_lock);
1051 		msgbuf_clearflag = 0;
1052 	}
1053 	return (error);
1054 }
1055 
1056 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
1057     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE | CTLFLAG_MPSAFE,
1058     &msgbuf_clearflag, 0, sysctl_kern_msgbuf_clear, "I",
1059     "Clear kernel message buffer");
1060 
1061 #ifdef DDB
1062 
1063 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
1064 {
1065 	int i, j;
1066 
1067 	if (!msgbufmapped) {
1068 		db_printf("msgbuf not mapped yet\n");
1069 		return;
1070 	}
1071 	db_printf("msgbufp = %p\n", msgbufp);
1072 	db_printf("magic = %x, size = %d, r= %u, w = %u, ptr = %p, cksum= %u\n",
1073 	    msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_rseq,
1074 	    msgbufp->msg_wseq, msgbufp->msg_ptr, msgbufp->msg_cksum);
1075 	for (i = 0; i < msgbufp->msg_size && !db_pager_quit; i++) {
1076 		j = MSGBUF_SEQ_TO_POS(msgbufp, i + msgbufp->msg_rseq);
1077 		db_printf("%c", msgbufp->msg_ptr[j]);
1078 	}
1079 	db_printf("\n");
1080 }
1081 
1082 #endif /* DDB */
1083 
1084 void
1085 hexdump(const void *ptr, int length, const char *hdr, int flags)
1086 {
1087 	int i, j, k;
1088 	int cols;
1089 	const unsigned char *cp;
1090 	char delim;
1091 
1092 	if ((flags & HD_DELIM_MASK) != 0)
1093 		delim = (flags & HD_DELIM_MASK) >> 8;
1094 	else
1095 		delim = ' ';
1096 
1097 	if ((flags & HD_COLUMN_MASK) != 0)
1098 		cols = flags & HD_COLUMN_MASK;
1099 	else
1100 		cols = 16;
1101 
1102 	cp = ptr;
1103 	for (i = 0; i < length; i+= cols) {
1104 		if (hdr != NULL)
1105 			printf("%s", hdr);
1106 
1107 		if ((flags & HD_OMIT_COUNT) == 0)
1108 			printf("%04x  ", i);
1109 
1110 		if ((flags & HD_OMIT_HEX) == 0) {
1111 			for (j = 0; j < cols; j++) {
1112 				k = i + j;
1113 				if (k < length)
1114 					printf("%c%02x", delim, cp[k]);
1115 				else
1116 					printf("   ");
1117 			}
1118 		}
1119 
1120 		if ((flags & HD_OMIT_CHARS) == 0) {
1121 			printf("  |");
1122 			for (j = 0; j < cols; j++) {
1123 				k = i + j;
1124 				if (k >= length)
1125 					printf(" ");
1126 				else if (cp[k] >= ' ' && cp[k] <= '~')
1127 					printf("%c", cp[k]);
1128 				else
1129 					printf(".");
1130 			}
1131 			printf("|");
1132 		}
1133 		printf("\n");
1134 	}
1135 }
1136 
1137