xref: /freebsd/sys/kern/subr_prf.c (revision a3cbca537ef1d8ac03a693cd51d98fb8087acc8d)
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 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RWTUN,
107     &log_console_output, 0, "Duplicate console output to the syslog");
108 
109 /*
110  * See the comment in log_console() below for more explanation of this.
111  */
112 static int log_console_add_linefeed;
113 SYSCTL_INT(_kern, OID_AUTO, log_console_add_linefeed, CTLFLAG_RWTUN,
114     &log_console_add_linefeed, 0, "log_console() adds extra newlines");
115 
116 static int always_console_output;
117 SYSCTL_INT(_kern, OID_AUTO, always_console_output, CTLFLAG_RWTUN,
118     &always_console_output, 0, "Always output to console despite TIOCCONS");
119 
120 /*
121  * Warn that a system table is full.
122  */
123 void
124 tablefull(const char *tab)
125 {
126 
127 	log(LOG_ERR, "%s: table is full\n", tab);
128 }
129 
130 /*
131  * Uprintf prints to the controlling terminal for the current process.
132  */
133 int
134 uprintf(const char *fmt, ...)
135 {
136 	va_list ap;
137 	struct putchar_arg pca;
138 	struct proc *p;
139 	struct thread *td;
140 	int retval;
141 
142 	td = curthread;
143 	if (TD_IS_IDLETHREAD(td))
144 		return (0);
145 
146 	sx_slock(&proctree_lock);
147 	p = td->td_proc;
148 	PROC_LOCK(p);
149 	if ((p->p_flag & P_CONTROLT) == 0) {
150 		PROC_UNLOCK(p);
151 		sx_sunlock(&proctree_lock);
152 		return (0);
153 	}
154 	SESS_LOCK(p->p_session);
155 	pca.tty = p->p_session->s_ttyp;
156 	SESS_UNLOCK(p->p_session);
157 	PROC_UNLOCK(p);
158 	if (pca.tty == NULL) {
159 		sx_sunlock(&proctree_lock);
160 		return (0);
161 	}
162 	pca.flags = TOTTY;
163 	pca.p_bufr = NULL;
164 	va_start(ap, fmt);
165 	tty_lock(pca.tty);
166 	sx_sunlock(&proctree_lock);
167 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
168 	tty_unlock(pca.tty);
169 	va_end(ap);
170 	return (retval);
171 }
172 
173 /*
174  * tprintf and vtprintf print on the controlling terminal associated with the
175  * given session, possibly to the log as well.
176  */
177 void
178 tprintf(struct proc *p, int pri, const char *fmt, ...)
179 {
180 	va_list ap;
181 
182 	va_start(ap, fmt);
183 	vtprintf(p, pri, fmt, ap);
184 	va_end(ap);
185 }
186 
187 void
188 vtprintf(struct proc *p, int pri, const char *fmt, va_list ap)
189 {
190 	struct tty *tp = NULL;
191 	int flags = 0;
192 	struct putchar_arg pca;
193 	struct session *sess = NULL;
194 
195 	sx_slock(&proctree_lock);
196 	if (pri != -1)
197 		flags |= TOLOG;
198 	if (p != NULL) {
199 		PROC_LOCK(p);
200 		if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
201 			sess = p->p_session;
202 			sess_hold(sess);
203 			PROC_UNLOCK(p);
204 			tp = sess->s_ttyp;
205 			if (tp != NULL && tty_checkoutq(tp))
206 				flags |= TOTTY;
207 			else
208 				tp = NULL;
209 		} else
210 			PROC_UNLOCK(p);
211 	}
212 	pca.pri = pri;
213 	pca.tty = tp;
214 	pca.flags = flags;
215 	pca.p_bufr = NULL;
216 	if (pca.tty != NULL)
217 		tty_lock(pca.tty);
218 	sx_sunlock(&proctree_lock);
219 	kvprintf(fmt, putchar, &pca, 10, ap);
220 	if (pca.tty != NULL)
221 		tty_unlock(pca.tty);
222 	if (sess != NULL)
223 		sess_release(sess);
224 	msgbuftrigger = 1;
225 }
226 
227 /*
228  * Ttyprintf displays a message on a tty; it should be used only by
229  * the tty driver, or anything that knows the underlying tty will not
230  * be revoke(2)'d away.  Other callers should use tprintf.
231  */
232 int
233 ttyprintf(struct tty *tp, const char *fmt, ...)
234 {
235 	va_list ap;
236 	struct putchar_arg pca;
237 	int retval;
238 
239 	va_start(ap, fmt);
240 	pca.tty = tp;
241 	pca.flags = TOTTY;
242 	pca.p_bufr = NULL;
243 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
244 	va_end(ap);
245 	return (retval);
246 }
247 
248 static int
249 _vprintf(int level, int flags, const char *fmt, va_list ap)
250 {
251 	struct putchar_arg pca;
252 	int retval;
253 #ifdef PRINTF_BUFR_SIZE
254 	char bufr[PRINTF_BUFR_SIZE];
255 #endif
256 
257 	pca.tty = NULL;
258 	pca.pri = level;
259 	pca.flags = flags;
260 #ifdef PRINTF_BUFR_SIZE
261 	pca.p_bufr = bufr;
262 	pca.p_next = pca.p_bufr;
263 	pca.n_bufr = sizeof(bufr);
264 	pca.remain = sizeof(bufr);
265 	*pca.p_next = '\0';
266 #else
267 	/* Don't buffer console output. */
268 	pca.p_bufr = NULL;
269 #endif
270 
271 	retval = kvprintf(fmt, putchar, &pca, 10, 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 
284 	return (retval);
285 }
286 
287 /*
288  * Log writes to the log buffer, and guarantees not to sleep (so can be
289  * called by interrupt routines).  If there is no process reading the
290  * log yet, it writes to the console also.
291  */
292 void
293 log(int level, const char *fmt, ...)
294 {
295 	va_list ap;
296 
297 	va_start(ap, fmt);
298 	(void)_vprintf(level, log_open ? TOLOG : TOCONS, fmt, ap);
299 	va_end(ap);
300 
301 	msgbuftrigger = 1;
302 }
303 
304 #define CONSCHUNK 128
305 
306 void
307 log_console(struct uio *uio)
308 {
309 	int c, error, nl;
310 	char *consbuffer;
311 	int pri;
312 
313 	if (!log_console_output)
314 		return;
315 
316 	pri = LOG_INFO | LOG_CONSOLE;
317 	uio = cloneuio(uio);
318 	consbuffer = malloc(CONSCHUNK, M_TEMP, M_WAITOK);
319 
320 	nl = 0;
321 	while (uio->uio_resid > 0) {
322 		c = imin(uio->uio_resid, CONSCHUNK - 1);
323 		error = uiomove(consbuffer, c, uio);
324 		if (error != 0)
325 			break;
326 		/* Make sure we're NUL-terminated */
327 		consbuffer[c] = '\0';
328 		if (consbuffer[c - 1] == '\n')
329 			nl = 1;
330 		else
331 			nl = 0;
332 		msglogstr(consbuffer, pri, /*filter_cr*/ 1);
333 	}
334 	/*
335 	 * The previous behavior in log_console() is preserved when
336 	 * log_console_add_linefeed is non-zero.  For that behavior, if an
337 	 * individual console write came in that was not terminated with a
338 	 * line feed, it would add a line feed.
339 	 *
340 	 * This results in different data in the message buffer than
341 	 * appears on the system console (which doesn't add extra line feed
342 	 * characters).
343 	 *
344 	 * A number of programs and rc scripts write a line feed, or a period
345 	 * and a line feed when they have completed their operation.  On
346 	 * the console, this looks seamless, but when displayed with
347 	 * 'dmesg -a', you wind up with output that looks like this:
348 	 *
349 	 * Updating motd:
350 	 * .
351 	 *
352 	 * On the console, it looks like this:
353 	 * Updating motd:.
354 	 *
355 	 * We could add logic to detect that situation, or just not insert
356 	 * the extra newlines.  Set the kern.log_console_add_linefeed
357 	 * sysctl/tunable variable to get the old behavior.
358 	 */
359 	if (!nl && log_console_add_linefeed) {
360 		consbuffer[0] = '\n';
361 		consbuffer[1] = '\0';
362 		msglogstr(consbuffer, pri, /*filter_cr*/ 1);
363 	}
364 	msgbuftrigger = 1;
365 	free(uio, M_IOV);
366 	free(consbuffer, M_TEMP);
367 	return;
368 }
369 
370 int
371 printf(const char *fmt, ...)
372 {
373 	va_list ap;
374 	int retval;
375 
376 	va_start(ap, fmt);
377 	retval = vprintf(fmt, ap);
378 	va_end(ap);
379 
380 	return (retval);
381 }
382 
383 int
384 vprintf(const char *fmt, va_list ap)
385 {
386 	int retval;
387 
388 	retval = _vprintf(-1, TOCONS | TOLOG, fmt, ap);
389 
390 	if (!panicstr)
391 		msgbuftrigger = 1;
392 
393 	return (retval);
394 }
395 
396 static void
397 putbuf(int c, struct putchar_arg *ap)
398 {
399 	/* Check if no console output buffer was provided. */
400 	if (ap->p_bufr == NULL) {
401 		/* Output direct to the console. */
402 		if (ap->flags & TOCONS)
403 			cnputc(c);
404 
405 		if (ap->flags & TOLOG)
406 			msglogchar(c, ap->pri);
407 	} else {
408 		/* Buffer the character: */
409 		*ap->p_next++ = c;
410 		ap->remain--;
411 
412 		/* Always leave the buffer zero terminated. */
413 		*ap->p_next = '\0';
414 
415 		/* Check if the buffer needs to be flushed. */
416 		if (ap->remain == 2 || c == '\n') {
417 
418 			if (ap->flags & TOLOG)
419 				msglogstr(ap->p_bufr, ap->pri, /*filter_cr*/1);
420 
421 			if (ap->flags & TOCONS) {
422 				if ((panicstr == NULL) && (constty != NULL))
423 					msgbuf_addstr(&consmsgbuf, -1,
424 					    ap->p_bufr, /*filter_cr*/ 0);
425 
426 				if ((constty == NULL) ||(always_console_output))
427 					cnputs(ap->p_bufr);
428 			}
429 
430 			ap->p_next = ap->p_bufr;
431 			ap->remain = ap->n_bufr;
432 			*ap->p_next = '\0';
433 		}
434 
435 		/*
436 		 * Since we fill the buffer up one character at a time,
437 		 * this should not happen.  We should always catch it when
438 		 * ap->remain == 2 (if not sooner due to a newline), flush
439 		 * the buffer and move on.  One way this could happen is
440 		 * if someone sets PRINTF_BUFR_SIZE to 1 or something
441 		 * similarly silly.
442 		 */
443 		KASSERT(ap->remain > 2, ("Bad buffer logic, remain = %zd",
444 		    ap->remain));
445 	}
446 }
447 
448 /*
449  * Print a character on console or users terminal.  If destination is
450  * the console then the last bunch of characters are saved in msgbuf for
451  * inspection later.
452  */
453 static void
454 putchar(int c, void *arg)
455 {
456 	struct putchar_arg *ap = (struct putchar_arg*) arg;
457 	struct tty *tp = ap->tty;
458 	int flags = ap->flags;
459 
460 	/* Don't use the tty code after a panic or while in ddb. */
461 	if (kdb_active) {
462 		if (c != '\0')
463 			cnputc(c);
464 		return;
465 	}
466 
467 	if ((flags & TOTTY) && tp != NULL && panicstr == NULL)
468 		tty_putchar(tp, c);
469 
470 	if ((flags & (TOCONS | TOLOG)) && c != '\0')
471 		putbuf(c, ap);
472 }
473 
474 /*
475  * Scaled down version of sprintf(3).
476  */
477 int
478 sprintf(char *buf, const char *cfmt, ...)
479 {
480 	int retval;
481 	va_list ap;
482 
483 	va_start(ap, cfmt);
484 	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
485 	buf[retval] = '\0';
486 	va_end(ap);
487 	return (retval);
488 }
489 
490 /*
491  * Scaled down version of vsprintf(3).
492  */
493 int
494 vsprintf(char *buf, const char *cfmt, va_list ap)
495 {
496 	int retval;
497 
498 	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
499 	buf[retval] = '\0';
500 	return (retval);
501 }
502 
503 /*
504  * Scaled down version of snprintf(3).
505  */
506 int
507 snprintf(char *str, size_t size, const char *format, ...)
508 {
509 	int retval;
510 	va_list ap;
511 
512 	va_start(ap, format);
513 	retval = vsnprintf(str, size, format, ap);
514 	va_end(ap);
515 	return(retval);
516 }
517 
518 /*
519  * Scaled down version of vsnprintf(3).
520  */
521 int
522 vsnprintf(char *str, size_t size, const char *format, va_list ap)
523 {
524 	struct snprintf_arg info;
525 	int retval;
526 
527 	info.str = str;
528 	info.remain = size;
529 	retval = kvprintf(format, snprintf_func, &info, 10, ap);
530 	if (info.remain >= 1)
531 		*info.str++ = '\0';
532 	return (retval);
533 }
534 
535 /*
536  * Kernel version which takes radix argument vsnprintf(3).
537  */
538 int
539 vsnrprintf(char *str, size_t size, int radix, const char *format, va_list ap)
540 {
541 	struct snprintf_arg info;
542 	int retval;
543 
544 	info.str = str;
545 	info.remain = size;
546 	retval = kvprintf(format, snprintf_func, &info, radix, ap);
547 	if (info.remain >= 1)
548 		*info.str++ = '\0';
549 	return (retval);
550 }
551 
552 static void
553 snprintf_func(int ch, void *arg)
554 {
555 	struct snprintf_arg *const info = arg;
556 
557 	if (info->remain >= 2) {
558 		*info->str++ = ch;
559 		info->remain--;
560 	}
561 }
562 
563 /*
564  * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
565  * order; return an optional length and a pointer to the last character
566  * written in the buffer (i.e., the first character of the string).
567  * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
568  */
569 static char *
570 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
571 {
572 	char *p, c;
573 
574 	p = nbuf;
575 	*p = '\0';
576 	do {
577 		c = hex2ascii(num % base);
578 		*++p = upper ? toupper(c) : c;
579 	} while (num /= base);
580 	if (lenp)
581 		*lenp = p - nbuf;
582 	return (p);
583 }
584 
585 /*
586  * Scaled down version of printf(3).
587  *
588  * Two additional formats:
589  *
590  * The format %b is supported to decode error registers.
591  * Its usage is:
592  *
593  *	printf("reg=%b\n", regval, "<base><arg>*");
594  *
595  * where <base> is the output base expressed as a control character, e.g.
596  * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
597  * the first of which gives the bit number to be inspected (origin 1), and
598  * the next characters (up to a control character, i.e. a character <= 32),
599  * give the name of the register.  Thus:
600  *
601  *	kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
602  *
603  * would produce output:
604  *
605  *	reg=3<BITTWO,BITONE>
606  *
607  * XXX:  %D  -- Hexdump, takes pointer and separator string:
608  *		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
609  *		("%*D", len, ptr, " " -> XX XX XX XX ...
610  */
611 int
612 kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap)
613 {
614 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; }
615 	char nbuf[MAXNBUF];
616 	char *d;
617 	const char *p, *percent, *q;
618 	u_char *up;
619 	int ch, n;
620 	uintmax_t num;
621 	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
622 	int cflag, hflag, jflag, tflag, zflag;
623 	int dwidth, upper;
624 	char padc;
625 	int stop = 0, retval = 0;
626 
627 	num = 0;
628 	if (!func)
629 		d = (char *) arg;
630 	else
631 		d = NULL;
632 
633 	if (fmt == NULL)
634 		fmt = "(fmt null)\n";
635 
636 	if (radix < 2 || radix > 36)
637 		radix = 10;
638 
639 	for (;;) {
640 		padc = ' ';
641 		width = 0;
642 		while ((ch = (u_char)*fmt++) != '%' || stop) {
643 			if (ch == '\0')
644 				return (retval);
645 			PCHAR(ch);
646 		}
647 		percent = fmt - 1;
648 		qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
649 		sign = 0; dot = 0; dwidth = 0; upper = 0;
650 		cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
651 reswitch:	switch (ch = (u_char)*fmt++) {
652 		case '.':
653 			dot = 1;
654 			goto reswitch;
655 		case '#':
656 			sharpflag = 1;
657 			goto reswitch;
658 		case '+':
659 			sign = 1;
660 			goto reswitch;
661 		case '-':
662 			ladjust = 1;
663 			goto reswitch;
664 		case '%':
665 			PCHAR(ch);
666 			break;
667 		case '*':
668 			if (!dot) {
669 				width = va_arg(ap, int);
670 				if (width < 0) {
671 					ladjust = !ladjust;
672 					width = -width;
673 				}
674 			} else {
675 				dwidth = va_arg(ap, int);
676 			}
677 			goto reswitch;
678 		case '0':
679 			if (!dot) {
680 				padc = '0';
681 				goto reswitch;
682 			}
683 		case '1': case '2': case '3': case '4':
684 		case '5': case '6': case '7': case '8': case '9':
685 				for (n = 0;; ++fmt) {
686 					n = n * 10 + ch - '0';
687 					ch = *fmt;
688 					if (ch < '0' || ch > '9')
689 						break;
690 				}
691 			if (dot)
692 				dwidth = n;
693 			else
694 				width = n;
695 			goto reswitch;
696 		case 'b':
697 			num = (u_int)va_arg(ap, int);
698 			p = va_arg(ap, char *);
699 			for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
700 				PCHAR(*q--);
701 
702 			if (num == 0)
703 				break;
704 
705 			for (tmp = 0; *p;) {
706 				n = *p++;
707 				if (num & (1 << (n - 1))) {
708 					PCHAR(tmp ? ',' : '<');
709 					for (; (n = *p) > ' '; ++p)
710 						PCHAR(n);
711 					tmp = 1;
712 				} else
713 					for (; *p > ' '; ++p)
714 						continue;
715 			}
716 			if (tmp)
717 				PCHAR('>');
718 			break;
719 		case 'c':
720 			PCHAR(va_arg(ap, int));
721 			break;
722 		case 'D':
723 			up = va_arg(ap, u_char *);
724 			p = va_arg(ap, char *);
725 			if (!width)
726 				width = 16;
727 			while(width--) {
728 				PCHAR(hex2ascii(*up >> 4));
729 				PCHAR(hex2ascii(*up & 0x0f));
730 				up++;
731 				if (width)
732 					for (q=p;*q;q++)
733 						PCHAR(*q);
734 			}
735 			break;
736 		case 'd':
737 		case 'i':
738 			base = 10;
739 			sign = 1;
740 			goto handle_sign;
741 		case 'h':
742 			if (hflag) {
743 				hflag = 0;
744 				cflag = 1;
745 			} else
746 				hflag = 1;
747 			goto reswitch;
748 		case 'j':
749 			jflag = 1;
750 			goto reswitch;
751 		case 'l':
752 			if (lflag) {
753 				lflag = 0;
754 				qflag = 1;
755 			} else
756 				lflag = 1;
757 			goto reswitch;
758 		case 'n':
759 			if (jflag)
760 				*(va_arg(ap, intmax_t *)) = retval;
761 			else if (qflag)
762 				*(va_arg(ap, quad_t *)) = retval;
763 			else if (lflag)
764 				*(va_arg(ap, long *)) = retval;
765 			else if (zflag)
766 				*(va_arg(ap, size_t *)) = retval;
767 			else if (hflag)
768 				*(va_arg(ap, short *)) = retval;
769 			else if (cflag)
770 				*(va_arg(ap, char *)) = retval;
771 			else
772 				*(va_arg(ap, int *)) = retval;
773 			break;
774 		case 'o':
775 			base = 8;
776 			goto handle_nosign;
777 		case 'p':
778 			base = 16;
779 			sharpflag = (width == 0);
780 			sign = 0;
781 			num = (uintptr_t)va_arg(ap, void *);
782 			goto number;
783 		case 'q':
784 			qflag = 1;
785 			goto reswitch;
786 		case 'r':
787 			base = radix;
788 			if (sign)
789 				goto handle_sign;
790 			goto handle_nosign;
791 		case 's':
792 			p = va_arg(ap, char *);
793 			if (p == NULL)
794 				p = "(null)";
795 			if (!dot)
796 				n = strlen (p);
797 			else
798 				for (n = 0; n < dwidth && p[n]; n++)
799 					continue;
800 
801 			width -= n;
802 
803 			if (!ladjust && width > 0)
804 				while (width--)
805 					PCHAR(padc);
806 			while (n--)
807 				PCHAR(*p++);
808 			if (ladjust && width > 0)
809 				while (width--)
810 					PCHAR(padc);
811 			break;
812 		case 't':
813 			tflag = 1;
814 			goto reswitch;
815 		case 'u':
816 			base = 10;
817 			goto handle_nosign;
818 		case 'X':
819 			upper = 1;
820 		case 'x':
821 			base = 16;
822 			goto handle_nosign;
823 		case 'y':
824 			base = 16;
825 			sign = 1;
826 			goto handle_sign;
827 		case 'z':
828 			zflag = 1;
829 			goto reswitch;
830 handle_nosign:
831 			sign = 0;
832 			if (jflag)
833 				num = va_arg(ap, uintmax_t);
834 			else if (qflag)
835 				num = va_arg(ap, u_quad_t);
836 			else if (tflag)
837 				num = va_arg(ap, ptrdiff_t);
838 			else if (lflag)
839 				num = va_arg(ap, u_long);
840 			else if (zflag)
841 				num = va_arg(ap, size_t);
842 			else if (hflag)
843 				num = (u_short)va_arg(ap, int);
844 			else if (cflag)
845 				num = (u_char)va_arg(ap, int);
846 			else
847 				num = va_arg(ap, u_int);
848 			goto number;
849 handle_sign:
850 			if (jflag)
851 				num = va_arg(ap, intmax_t);
852 			else if (qflag)
853 				num = va_arg(ap, quad_t);
854 			else if (tflag)
855 				num = va_arg(ap, ptrdiff_t);
856 			else if (lflag)
857 				num = va_arg(ap, long);
858 			else if (zflag)
859 				num = va_arg(ap, ssize_t);
860 			else if (hflag)
861 				num = (short)va_arg(ap, int);
862 			else if (cflag)
863 				num = (char)va_arg(ap, int);
864 			else
865 				num = va_arg(ap, int);
866 number:
867 			if (sign && (intmax_t)num < 0) {
868 				neg = 1;
869 				num = -(intmax_t)num;
870 			}
871 			p = ksprintn(nbuf, num, base, &n, upper);
872 			tmp = 0;
873 			if (sharpflag && num != 0) {
874 				if (base == 8)
875 					tmp++;
876 				else if (base == 16)
877 					tmp += 2;
878 			}
879 			if (neg)
880 				tmp++;
881 
882 			if (!ladjust && padc == '0')
883 				dwidth = width - tmp;
884 			width -= tmp + imax(dwidth, n);
885 			dwidth -= n;
886 			if (!ladjust)
887 				while (width-- > 0)
888 					PCHAR(' ');
889 			if (neg)
890 				PCHAR('-');
891 			if (sharpflag && num != 0) {
892 				if (base == 8) {
893 					PCHAR('0');
894 				} else if (base == 16) {
895 					PCHAR('0');
896 					PCHAR('x');
897 				}
898 			}
899 			while (dwidth-- > 0)
900 				PCHAR('0');
901 
902 			while (*p)
903 				PCHAR(*p--);
904 
905 			if (ladjust)
906 				while (width-- > 0)
907 					PCHAR(' ');
908 
909 			break;
910 		default:
911 			while (percent < fmt)
912 				PCHAR(*percent++);
913 			/*
914 			 * Since we ignore a formatting argument it is no
915 			 * longer safe to obey the remaining formatting
916 			 * arguments as the arguments will no longer match
917 			 * the format specs.
918 			 */
919 			stop = 1;
920 			break;
921 		}
922 	}
923 #undef PCHAR
924 }
925 
926 /*
927  * Put character in log buffer with a particular priority.
928  */
929 static void
930 msglogchar(int c, int pri)
931 {
932 	static int lastpri = -1;
933 	static int dangling;
934 	char nbuf[MAXNBUF];
935 	char *p;
936 
937 	if (!msgbufmapped)
938 		return;
939 	if (c == '\0' || c == '\r')
940 		return;
941 	if (pri != -1 && pri != lastpri) {
942 		if (dangling) {
943 			msgbuf_addchar(msgbufp, '\n');
944 			dangling = 0;
945 		}
946 		msgbuf_addchar(msgbufp, '<');
947 		for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL, 0); *p;)
948 			msgbuf_addchar(msgbufp, *p--);
949 		msgbuf_addchar(msgbufp, '>');
950 		lastpri = pri;
951 	}
952 	msgbuf_addchar(msgbufp, c);
953 	if (c == '\n') {
954 		dangling = 0;
955 		lastpri = -1;
956 	} else {
957 		dangling = 1;
958 	}
959 }
960 
961 static void
962 msglogstr(char *str, int pri, int filter_cr)
963 {
964 	if (!msgbufmapped)
965 		return;
966 
967 	msgbuf_addstr(msgbufp, pri, str, filter_cr);
968 }
969 
970 void
971 msgbufinit(void *ptr, int size)
972 {
973 	char *cp;
974 	static struct msgbuf *oldp = NULL;
975 
976 	size -= sizeof(*msgbufp);
977 	cp = (char *)ptr;
978 	msgbufp = (struct msgbuf *)(cp + size);
979 	msgbuf_reinit(msgbufp, cp, size);
980 	if (msgbufmapped && oldp != msgbufp)
981 		msgbuf_copy(oldp, msgbufp);
982 	msgbufmapped = 1;
983 	oldp = msgbufp;
984 }
985 
986 static int unprivileged_read_msgbuf = 1;
987 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_read_msgbuf,
988     CTLFLAG_RW, &unprivileged_read_msgbuf, 0,
989     "Unprivileged processes may read the kernel message buffer");
990 
991 /* Sysctls for accessing/clearing the msgbuf */
992 static int
993 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
994 {
995 	char buf[128];
996 	u_int seq;
997 	int error, len;
998 
999 	if (!unprivileged_read_msgbuf) {
1000 		error = priv_check(req->td, PRIV_MSGBUF);
1001 		if (error)
1002 			return (error);
1003 	}
1004 
1005 	/* Read the whole buffer, one chunk at a time. */
1006 	mtx_lock(&msgbuf_lock);
1007 	msgbuf_peekbytes(msgbufp, NULL, 0, &seq);
1008 	for (;;) {
1009 		len = msgbuf_peekbytes(msgbufp, buf, sizeof(buf), &seq);
1010 		mtx_unlock(&msgbuf_lock);
1011 		if (len == 0)
1012 			return (0);
1013 
1014 		error = sysctl_handle_opaque(oidp, buf, len, req);
1015 		if (error)
1016 			return (error);
1017 
1018 		mtx_lock(&msgbuf_lock);
1019 	}
1020 }
1021 
1022 SYSCTL_PROC(_kern, OID_AUTO, msgbuf,
1023     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
1024     NULL, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
1025 
1026 static int msgbuf_clearflag;
1027 
1028 static int
1029 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
1030 {
1031 	int error;
1032 	error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
1033 	if (!error && req->newptr) {
1034 		mtx_lock(&msgbuf_lock);
1035 		msgbuf_clear(msgbufp);
1036 		mtx_unlock(&msgbuf_lock);
1037 		msgbuf_clearflag = 0;
1038 	}
1039 	return (error);
1040 }
1041 
1042 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
1043     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE | CTLFLAG_MPSAFE,
1044     &msgbuf_clearflag, 0, sysctl_kern_msgbuf_clear, "I",
1045     "Clear kernel message buffer");
1046 
1047 #ifdef DDB
1048 
1049 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
1050 {
1051 	int i, j;
1052 
1053 	if (!msgbufmapped) {
1054 		db_printf("msgbuf not mapped yet\n");
1055 		return;
1056 	}
1057 	db_printf("msgbufp = %p\n", msgbufp);
1058 	db_printf("magic = %x, size = %d, r= %u, w = %u, ptr = %p, cksum= %u\n",
1059 	    msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_rseq,
1060 	    msgbufp->msg_wseq, msgbufp->msg_ptr, msgbufp->msg_cksum);
1061 	for (i = 0; i < msgbufp->msg_size && !db_pager_quit; i++) {
1062 		j = MSGBUF_SEQ_TO_POS(msgbufp, i + msgbufp->msg_rseq);
1063 		db_printf("%c", msgbufp->msg_ptr[j]);
1064 	}
1065 	db_printf("\n");
1066 }
1067 
1068 #endif /* DDB */
1069 
1070 void
1071 hexdump(const void *ptr, int length, const char *hdr, int flags)
1072 {
1073 	int i, j, k;
1074 	int cols;
1075 	const unsigned char *cp;
1076 	char delim;
1077 
1078 	if ((flags & HD_DELIM_MASK) != 0)
1079 		delim = (flags & HD_DELIM_MASK) >> 8;
1080 	else
1081 		delim = ' ';
1082 
1083 	if ((flags & HD_COLUMN_MASK) != 0)
1084 		cols = flags & HD_COLUMN_MASK;
1085 	else
1086 		cols = 16;
1087 
1088 	cp = ptr;
1089 	for (i = 0; i < length; i+= cols) {
1090 		if (hdr != NULL)
1091 			printf("%s", hdr);
1092 
1093 		if ((flags & HD_OMIT_COUNT) == 0)
1094 			printf("%04x  ", i);
1095 
1096 		if ((flags & HD_OMIT_HEX) == 0) {
1097 			for (j = 0; j < cols; j++) {
1098 				k = i + j;
1099 				if (k < length)
1100 					printf("%c%02x", delim, cp[k]);
1101 				else
1102 					printf("   ");
1103 			}
1104 		}
1105 
1106 		if ((flags & HD_OMIT_CHARS) == 0) {
1107 			printf("  |");
1108 			for (j = 0; j < cols; j++) {
1109 				k = i + j;
1110 				if (k >= length)
1111 					printf(" ");
1112 				else if (cp[k] >= ' ' && cp[k] <= '~')
1113 					printf("%c", cp[k]);
1114 				else
1115 					printf(".");
1116 			}
1117 			printf("|");
1118 		}
1119 		printf("\n");
1120 	}
1121 }
1122