xref: /freebsd/sys/kern/subr_prf.c (revision 54ebdd631db8c0bba2baab0155f603a8b5cf014a)
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  putchar(int ch, void *arg);
98 static char *ksprintn(char *nbuf, uintmax_t num, int base, int *len, int upper);
99 static void  snprintf_func(int ch, void *arg);
100 
101 static int msgbufmapped;		/* Set when safe to use msgbuf */
102 int msgbuftrigger;
103 
104 static int      log_console_output = 1;
105 TUNABLE_INT("kern.log_console_output", &log_console_output);
106 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW,
107     &log_console_output, 0, "Duplicate console output to the syslog.");
108 
109 static int	always_console_output = 0;
110 TUNABLE_INT("kern.always_console_output", &always_console_output);
111 SYSCTL_INT(_kern, OID_AUTO, always_console_output, CTLFLAG_RW,
112     &always_console_output, 0, "Always output to console despite TIOCCONS.");
113 
114 /*
115  * Warn that a system table is full.
116  */
117 void
118 tablefull(const char *tab)
119 {
120 
121 	log(LOG_ERR, "%s: table is full\n", tab);
122 }
123 
124 /*
125  * Uprintf prints to the controlling terminal for the current process.
126  */
127 int
128 uprintf(const char *fmt, ...)
129 {
130 	struct thread *td = curthread;
131 	struct proc *p = td->td_proc;
132 	va_list ap;
133 	struct putchar_arg pca;
134 	int retval;
135 
136 	if (td == NULL || TD_IS_IDLETHREAD(td))
137 		return (0);
138 
139 	sx_slock(&proctree_lock);
140 	p = td->td_proc;
141 	PROC_LOCK(p);
142 	if ((p->p_flag & P_CONTROLT) == 0) {
143 		PROC_UNLOCK(p);
144 		retval = 0;
145 		goto out;
146 	}
147 	SESS_LOCK(p->p_session);
148 	pca.tty = p->p_session->s_ttyp;
149 	SESS_UNLOCK(p->p_session);
150 	PROC_UNLOCK(p);
151 	if (pca.tty == NULL) {
152 		retval = 0;
153 		goto out;
154 	}
155 	pca.flags = TOTTY;
156 	va_start(ap, fmt);
157 	tty_lock(pca.tty);
158 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
159 	tty_unlock(pca.tty);
160 	va_end(ap);
161 out:
162 	sx_sunlock(&proctree_lock);
163 	return (retval);
164 }
165 
166 /*
167  * tprintf prints on the controlling terminal associated with the given
168  * session, possibly to the log as well.
169  */
170 void
171 tprintf(struct proc *p, int pri, const char *fmt, ...)
172 {
173 	struct tty *tp = NULL;
174 	int flags = 0;
175 	va_list ap;
176 	struct putchar_arg pca;
177 	struct session *sess = NULL;
178 
179 	sx_slock(&proctree_lock);
180 	if (pri != -1)
181 		flags |= TOLOG;
182 	if (p != NULL) {
183 		PROC_LOCK(p);
184 		if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
185 			sess = p->p_session;
186 			sess_hold(sess);
187 			PROC_UNLOCK(p);
188 			tp = sess->s_ttyp;
189 			if (tp != NULL && tty_checkoutq(tp))
190 				flags |= TOTTY;
191 			else
192 				tp = NULL;
193 		} else
194 			PROC_UNLOCK(p);
195 	}
196 	pca.pri = pri;
197 	pca.tty = tp;
198 	pca.flags = flags;
199 	va_start(ap, fmt);
200 	if (pca.tty != NULL)
201 		tty_lock(pca.tty);
202 	kvprintf(fmt, putchar, &pca, 10, ap);
203 	if (pca.tty != NULL)
204 		tty_unlock(pca.tty);
205 	va_end(ap);
206 	if (sess != NULL)
207 		sess_release(sess);
208 	msgbuftrigger = 1;
209 	sx_sunlock(&proctree_lock);
210 }
211 
212 /*
213  * Ttyprintf displays a message on a tty; it should be used only by
214  * the tty driver, or anything that knows the underlying tty will not
215  * be revoke(2)'d away.  Other callers should use tprintf.
216  */
217 int
218 ttyprintf(struct tty *tp, const char *fmt, ...)
219 {
220 	va_list ap;
221 	struct putchar_arg pca;
222 	int retval;
223 
224 	va_start(ap, fmt);
225 	pca.tty = tp;
226 	pca.flags = TOTTY;
227 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
228 	va_end(ap);
229 	return (retval);
230 }
231 
232 /*
233  * Log writes to the log buffer, and guarantees not to sleep (so can be
234  * called by interrupt routines).  If there is no process reading the
235  * log yet, it writes to the console also.
236  */
237 void
238 log(int level, const char *fmt, ...)
239 {
240 	va_list ap;
241 	struct putchar_arg pca;
242 
243 	pca.tty = NULL;
244 	pca.pri = level;
245 	pca.flags = log_open ? TOLOG : TOCONS;
246 	pca.p_bufr = NULL;
247 
248 	va_start(ap, fmt);
249 	kvprintf(fmt, putchar, &pca, 10, ap);
250 	va_end(ap);
251 
252 	msgbuftrigger = 1;
253 }
254 
255 #define CONSCHUNK 128
256 
257 void
258 log_console(struct uio *uio)
259 {
260 	int c, i, error;
261 	char *consbuffer;
262 	int pri;
263 
264 	if (!log_console_output)
265 		return;
266 
267 	pri = LOG_INFO | LOG_CONSOLE;
268 	uio = cloneuio(uio);
269 	consbuffer = malloc(CONSCHUNK, M_TEMP, M_WAITOK);
270 
271 	while (uio->uio_resid > 0) {
272 		c = imin(uio->uio_resid, CONSCHUNK);
273 		error = uiomove(consbuffer, c, uio);
274 		if (error != 0)
275 			break;
276 		for (i = 0; i < c; i++)
277 			msglogchar(consbuffer[i], pri);
278 	}
279 	msgbuftrigger = 1;
280 	free(uio, M_IOV);
281 	free(consbuffer, M_TEMP);
282 	return;
283 }
284 
285 int
286 printf(const char *fmt, ...)
287 {
288 	va_list ap;
289 	struct putchar_arg pca;
290 	int retval;
291 #ifdef PRINTF_BUFR_SIZE
292 	char bufr[PRINTF_BUFR_SIZE];
293 #endif
294 
295 	va_start(ap, fmt);
296 	pca.tty = NULL;
297 	pca.flags = TOCONS | TOLOG;
298 	pca.pri = -1;
299 #ifdef PRINTF_BUFR_SIZE
300 	pca.p_bufr = bufr;
301 	pca.p_next = pca.p_bufr;
302 	pca.n_bufr = sizeof(bufr);
303 	pca.remain = sizeof(bufr);
304 	*pca.p_next = '\0';
305 #else
306 	/* Don't buffer console output. */
307 	pca.p_bufr = NULL;
308 #endif
309 
310 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
311 	va_end(ap);
312 
313 #ifdef PRINTF_BUFR_SIZE
314 	/* Write any buffered console output: */
315 	if (*pca.p_bufr != '\0')
316 		cnputs(pca.p_bufr);
317 #endif
318 
319 	if (!panicstr)
320 		msgbuftrigger = 1;
321 
322 	return (retval);
323 }
324 
325 int
326 vprintf(const char *fmt, va_list ap)
327 {
328 	struct putchar_arg pca;
329 	int retval;
330 #ifdef PRINTF_BUFR_SIZE
331 	char bufr[PRINTF_BUFR_SIZE];
332 #endif
333 
334 	pca.tty = NULL;
335 	pca.flags = TOCONS | TOLOG;
336 	pca.pri = -1;
337 #ifdef PRINTF_BUFR_SIZE
338 	pca.p_bufr = bufr;
339 	pca.p_next = pca.p_bufr;
340 	pca.n_bufr = sizeof(bufr);
341 	pca.remain = sizeof(bufr);
342 	*pca.p_next = '\0';
343 #else
344 	/* Don't buffer console output. */
345 	pca.p_bufr = NULL;
346 #endif
347 
348 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
349 
350 #ifdef PRINTF_BUFR_SIZE
351 	/* Write any buffered console output: */
352 	if (*pca.p_bufr != '\0')
353 		cnputs(pca.p_bufr);
354 #endif
355 
356 	if (!panicstr)
357 		msgbuftrigger = 1;
358 
359 	return (retval);
360 }
361 
362 static void
363 putcons(int c, struct putchar_arg *ap)
364 {
365 	/* Check if no console output buffer was provided. */
366 	if (ap->p_bufr == NULL)
367 		/* Output direct to the console. */
368 		cnputc(c);
369 	else {
370 		/* Buffer the character: */
371 		if (c == '\n') {
372 			*ap->p_next++ = '\r';
373 			ap->remain--;
374 		}
375 		*ap->p_next++ = c;
376 		ap->remain--;
377 
378 		/* Always leave the buffer zero terminated. */
379 		*ap->p_next = '\0';
380 
381 		/* Check if the buffer needs to be flushed. */
382 		if (ap->remain < 3 || c == '\n') {
383 			cnputs(ap->p_bufr);
384 			ap->p_next = ap->p_bufr;
385 			ap->remain = ap->n_bufr;
386 			*ap->p_next = '\0';
387 		}
388 	}
389 }
390 
391 /*
392  * Print a character on console or users terminal.  If destination is
393  * the console then the last bunch of characters are saved in msgbuf for
394  * inspection later.
395  */
396 static void
397 putchar(int c, void *arg)
398 {
399 	struct putchar_arg *ap = (struct putchar_arg*) arg;
400 	struct tty *tp = ap->tty;
401 	int flags = ap->flags;
402 
403 	/* Don't use the tty code after a panic or while in ddb. */
404 	if (kdb_active) {
405 		if (c != '\0')
406 			cnputc(c);
407 	} else if (panicstr || ((flags & TOCONS) && constty == NULL)) {
408 		if (c != '\0')
409 			putcons(c, ap);
410 	} else {
411 		if ((flags & TOTTY) && tp != NULL)
412 			tty_putchar(tp, c);
413 		if (flags & TOCONS) {
414 			if (constty != NULL)
415 				msgbuf_addchar(&consmsgbuf, c);
416 			if (always_console_output && c != '\0')
417 				putcons(c, ap);
418 		}
419 	}
420 	if ((flags & TOLOG))
421 		msglogchar(c, ap->pri);
422 }
423 
424 /*
425  * Scaled down version of sprintf(3).
426  */
427 int
428 sprintf(char *buf, const char *cfmt, ...)
429 {
430 	int retval;
431 	va_list ap;
432 
433 	va_start(ap, cfmt);
434 	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
435 	buf[retval] = '\0';
436 	va_end(ap);
437 	return (retval);
438 }
439 
440 /*
441  * Scaled down version of vsprintf(3).
442  */
443 int
444 vsprintf(char *buf, const char *cfmt, va_list ap)
445 {
446 	int retval;
447 
448 	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
449 	buf[retval] = '\0';
450 	return (retval);
451 }
452 
453 /*
454  * Scaled down version of snprintf(3).
455  */
456 int
457 snprintf(char *str, size_t size, const char *format, ...)
458 {
459 	int retval;
460 	va_list ap;
461 
462 	va_start(ap, format);
463 	retval = vsnprintf(str, size, format, ap);
464 	va_end(ap);
465 	return(retval);
466 }
467 
468 /*
469  * Scaled down version of vsnprintf(3).
470  */
471 int
472 vsnprintf(char *str, size_t size, const char *format, va_list ap)
473 {
474 	struct snprintf_arg info;
475 	int retval;
476 
477 	info.str = str;
478 	info.remain = size;
479 	retval = kvprintf(format, snprintf_func, &info, 10, ap);
480 	if (info.remain >= 1)
481 		*info.str++ = '\0';
482 	return (retval);
483 }
484 
485 /*
486  * Kernel version which takes radix argument vsnprintf(3).
487  */
488 int
489 vsnrprintf(char *str, size_t size, int radix, const char *format, va_list ap)
490 {
491 	struct snprintf_arg info;
492 	int retval;
493 
494 	info.str = str;
495 	info.remain = size;
496 	retval = kvprintf(format, snprintf_func, &info, radix, ap);
497 	if (info.remain >= 1)
498 		*info.str++ = '\0';
499 	return (retval);
500 }
501 
502 static void
503 snprintf_func(int ch, void *arg)
504 {
505 	struct snprintf_arg *const info = arg;
506 
507 	if (info->remain >= 2) {
508 		*info->str++ = ch;
509 		info->remain--;
510 	}
511 }
512 
513 /*
514  * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
515  * order; return an optional length and a pointer to the last character
516  * written in the buffer (i.e., the first character of the string).
517  * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
518  */
519 static char *
520 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
521 {
522 	char *p, c;
523 
524 	p = nbuf;
525 	*p = '\0';
526 	do {
527 		c = hex2ascii(num % base);
528 		*++p = upper ? toupper(c) : c;
529 	} while (num /= base);
530 	if (lenp)
531 		*lenp = p - nbuf;
532 	return (p);
533 }
534 
535 /*
536  * Scaled down version of printf(3).
537  *
538  * Two additional formats:
539  *
540  * The format %b is supported to decode error registers.
541  * Its usage is:
542  *
543  *	printf("reg=%b\n", regval, "<base><arg>*");
544  *
545  * where <base> is the output base expressed as a control character, e.g.
546  * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
547  * the first of which gives the bit number to be inspected (origin 1), and
548  * the next characters (up to a control character, i.e. a character <= 32),
549  * give the name of the register.  Thus:
550  *
551  *	kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
552  *
553  * would produce output:
554  *
555  *	reg=3<BITTWO,BITONE>
556  *
557  * XXX:  %D  -- Hexdump, takes pointer and separator string:
558  *		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
559  *		("%*D", len, ptr, " " -> XX XX XX XX ...
560  */
561 int
562 kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap)
563 {
564 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; }
565 	char nbuf[MAXNBUF];
566 	char *d;
567 	const char *p, *percent, *q;
568 	u_char *up;
569 	int ch, n;
570 	uintmax_t num;
571 	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
572 	int cflag, hflag, jflag, tflag, zflag;
573 	int dwidth, upper;
574 	char padc;
575 	int stop = 0, retval = 0;
576 
577 	num = 0;
578 	if (!func)
579 		d = (char *) arg;
580 	else
581 		d = NULL;
582 
583 	if (fmt == NULL)
584 		fmt = "(fmt null)\n";
585 
586 	if (radix < 2 || radix > 36)
587 		radix = 10;
588 
589 	for (;;) {
590 		padc = ' ';
591 		width = 0;
592 		while ((ch = (u_char)*fmt++) != '%' || stop) {
593 			if (ch == '\0')
594 				return (retval);
595 			PCHAR(ch);
596 		}
597 		percent = fmt - 1;
598 		qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
599 		sign = 0; dot = 0; dwidth = 0; upper = 0;
600 		cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
601 reswitch:	switch (ch = (u_char)*fmt++) {
602 		case '.':
603 			dot = 1;
604 			goto reswitch;
605 		case '#':
606 			sharpflag = 1;
607 			goto reswitch;
608 		case '+':
609 			sign = 1;
610 			goto reswitch;
611 		case '-':
612 			ladjust = 1;
613 			goto reswitch;
614 		case '%':
615 			PCHAR(ch);
616 			break;
617 		case '*':
618 			if (!dot) {
619 				width = va_arg(ap, int);
620 				if (width < 0) {
621 					ladjust = !ladjust;
622 					width = -width;
623 				}
624 			} else {
625 				dwidth = va_arg(ap, int);
626 			}
627 			goto reswitch;
628 		case '0':
629 			if (!dot) {
630 				padc = '0';
631 				goto reswitch;
632 			}
633 		case '1': case '2': case '3': case '4':
634 		case '5': case '6': case '7': case '8': case '9':
635 				for (n = 0;; ++fmt) {
636 					n = n * 10 + ch - '0';
637 					ch = *fmt;
638 					if (ch < '0' || ch > '9')
639 						break;
640 				}
641 			if (dot)
642 				dwidth = n;
643 			else
644 				width = n;
645 			goto reswitch;
646 		case 'b':
647 			num = (u_int)va_arg(ap, int);
648 			p = va_arg(ap, char *);
649 			for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
650 				PCHAR(*q--);
651 
652 			if (num == 0)
653 				break;
654 
655 			for (tmp = 0; *p;) {
656 				n = *p++;
657 				if (num & (1 << (n - 1))) {
658 					PCHAR(tmp ? ',' : '<');
659 					for (; (n = *p) > ' '; ++p)
660 						PCHAR(n);
661 					tmp = 1;
662 				} else
663 					for (; *p > ' '; ++p)
664 						continue;
665 			}
666 			if (tmp)
667 				PCHAR('>');
668 			break;
669 		case 'c':
670 			PCHAR(va_arg(ap, int));
671 			break;
672 		case 'D':
673 			up = va_arg(ap, u_char *);
674 			p = va_arg(ap, char *);
675 			if (!width)
676 				width = 16;
677 			while(width--) {
678 				PCHAR(hex2ascii(*up >> 4));
679 				PCHAR(hex2ascii(*up & 0x0f));
680 				up++;
681 				if (width)
682 					for (q=p;*q;q++)
683 						PCHAR(*q);
684 			}
685 			break;
686 		case 'd':
687 		case 'i':
688 			base = 10;
689 			sign = 1;
690 			goto handle_sign;
691 		case 'h':
692 			if (hflag) {
693 				hflag = 0;
694 				cflag = 1;
695 			} else
696 				hflag = 1;
697 			goto reswitch;
698 		case 'j':
699 			jflag = 1;
700 			goto reswitch;
701 		case 'l':
702 			if (lflag) {
703 				lflag = 0;
704 				qflag = 1;
705 			} else
706 				lflag = 1;
707 			goto reswitch;
708 		case 'n':
709 			if (jflag)
710 				*(va_arg(ap, intmax_t *)) = retval;
711 			else if (qflag)
712 				*(va_arg(ap, quad_t *)) = retval;
713 			else if (lflag)
714 				*(va_arg(ap, long *)) = retval;
715 			else if (zflag)
716 				*(va_arg(ap, size_t *)) = retval;
717 			else if (hflag)
718 				*(va_arg(ap, short *)) = retval;
719 			else if (cflag)
720 				*(va_arg(ap, char *)) = retval;
721 			else
722 				*(va_arg(ap, int *)) = retval;
723 			break;
724 		case 'o':
725 			base = 8;
726 			goto handle_nosign;
727 		case 'p':
728 			base = 16;
729 			sharpflag = (width == 0);
730 			sign = 0;
731 			num = (uintptr_t)va_arg(ap, void *);
732 			goto number;
733 		case 'q':
734 			qflag = 1;
735 			goto reswitch;
736 		case 'r':
737 			base = radix;
738 			if (sign)
739 				goto handle_sign;
740 			goto handle_nosign;
741 		case 's':
742 			p = va_arg(ap, char *);
743 			if (p == NULL)
744 				p = "(null)";
745 			if (!dot)
746 				n = strlen (p);
747 			else
748 				for (n = 0; n < dwidth && p[n]; n++)
749 					continue;
750 
751 			width -= n;
752 
753 			if (!ladjust && width > 0)
754 				while (width--)
755 					PCHAR(padc);
756 			while (n--)
757 				PCHAR(*p++);
758 			if (ladjust && width > 0)
759 				while (width--)
760 					PCHAR(padc);
761 			break;
762 		case 't':
763 			tflag = 1;
764 			goto reswitch;
765 		case 'u':
766 			base = 10;
767 			goto handle_nosign;
768 		case 'X':
769 			upper = 1;
770 		case 'x':
771 			base = 16;
772 			goto handle_nosign;
773 		case 'y':
774 			base = 16;
775 			sign = 1;
776 			goto handle_sign;
777 		case 'z':
778 			zflag = 1;
779 			goto reswitch;
780 handle_nosign:
781 			sign = 0;
782 			if (jflag)
783 				num = va_arg(ap, uintmax_t);
784 			else if (qflag)
785 				num = va_arg(ap, u_quad_t);
786 			else if (tflag)
787 				num = va_arg(ap, ptrdiff_t);
788 			else if (lflag)
789 				num = va_arg(ap, u_long);
790 			else if (zflag)
791 				num = va_arg(ap, size_t);
792 			else if (hflag)
793 				num = (u_short)va_arg(ap, int);
794 			else if (cflag)
795 				num = (u_char)va_arg(ap, int);
796 			else
797 				num = va_arg(ap, u_int);
798 			goto number;
799 handle_sign:
800 			if (jflag)
801 				num = va_arg(ap, intmax_t);
802 			else if (qflag)
803 				num = va_arg(ap, quad_t);
804 			else if (tflag)
805 				num = va_arg(ap, ptrdiff_t);
806 			else if (lflag)
807 				num = va_arg(ap, long);
808 			else if (zflag)
809 				num = va_arg(ap, ssize_t);
810 			else if (hflag)
811 				num = (short)va_arg(ap, int);
812 			else if (cflag)
813 				num = (char)va_arg(ap, int);
814 			else
815 				num = va_arg(ap, int);
816 number:
817 			if (sign && (intmax_t)num < 0) {
818 				neg = 1;
819 				num = -(intmax_t)num;
820 			}
821 			p = ksprintn(nbuf, num, base, &tmp, upper);
822 			if (sharpflag && num != 0) {
823 				if (base == 8)
824 					tmp++;
825 				else if (base == 16)
826 					tmp += 2;
827 			}
828 			if (neg)
829 				tmp++;
830 
831 			if (!ladjust && padc != '0' && width
832 			    && (width -= tmp) > 0)
833 				while (width--)
834 					PCHAR(padc);
835 			if (neg)
836 				PCHAR('-');
837 			if (sharpflag && num != 0) {
838 				if (base == 8) {
839 					PCHAR('0');
840 				} else if (base == 16) {
841 					PCHAR('0');
842 					PCHAR('x');
843 				}
844 			}
845 			if (!ladjust && width && (width -= tmp) > 0)
846 				while (width--)
847 					PCHAR(padc);
848 
849 			while (*p)
850 				PCHAR(*p--);
851 
852 			if (ladjust && width && (width -= tmp) > 0)
853 				while (width--)
854 					PCHAR(padc);
855 
856 			break;
857 		default:
858 			while (percent < fmt)
859 				PCHAR(*percent++);
860 			/*
861 			 * Since we ignore an formatting argument it is no
862 			 * longer safe to obey the remaining formatting
863 			 * arguments as the arguments will no longer match
864 			 * the format specs.
865 			 */
866 			stop = 1;
867 			break;
868 		}
869 	}
870 #undef PCHAR
871 }
872 
873 /*
874  * Put character in log buffer with a particular priority.
875  */
876 static void
877 msglogchar(int c, int pri)
878 {
879 	static int lastpri = -1;
880 	static int dangling;
881 	char nbuf[MAXNBUF];
882 	char *p;
883 
884 	if (!msgbufmapped)
885 		return;
886 	if (c == '\0' || c == '\r')
887 		return;
888 	if (pri != -1 && pri != lastpri) {
889 		if (dangling) {
890 			msgbuf_addchar(msgbufp, '\n');
891 			dangling = 0;
892 		}
893 		msgbuf_addchar(msgbufp, '<');
894 		for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL, 0); *p;)
895 			msgbuf_addchar(msgbufp, *p--);
896 		msgbuf_addchar(msgbufp, '>');
897 		lastpri = pri;
898 	}
899 	msgbuf_addchar(msgbufp, c);
900 	if (c == '\n') {
901 		dangling = 0;
902 		lastpri = -1;
903 	} else {
904 		dangling = 1;
905 	}
906 }
907 
908 void
909 msgbufinit(void *ptr, int size)
910 {
911 	char *cp;
912 	static struct msgbuf *oldp = NULL;
913 
914 	size -= sizeof(*msgbufp);
915 	cp = (char *)ptr;
916 	msgbufp = (struct msgbuf *)(cp + size);
917 	msgbuf_reinit(msgbufp, cp, size);
918 	if (msgbufmapped && oldp != msgbufp)
919 		msgbuf_copy(oldp, msgbufp);
920 	msgbufmapped = 1;
921 	oldp = msgbufp;
922 }
923 
924 static int unprivileged_read_msgbuf = 1;
925 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_read_msgbuf,
926     CTLFLAG_RW, &unprivileged_read_msgbuf, 0,
927     "Unprivileged processes may read the kernel message buffer");
928 
929 /* Sysctls for accessing/clearing the msgbuf */
930 static int
931 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
932 {
933 	char buf[128];
934 	u_int seq;
935 	int error, len;
936 
937 	if (!unprivileged_read_msgbuf) {
938 		error = priv_check(req->td, PRIV_MSGBUF);
939 		if (error)
940 			return (error);
941 	}
942 
943 	/* Read the whole buffer, one chunk at a time. */
944 	msgbuf_peekbytes(msgbufp, NULL, 0, &seq);
945 	while ((len = msgbuf_peekbytes(msgbufp, buf, sizeof(buf), &seq)) > 0) {
946 		error = sysctl_handle_opaque(oidp, buf, len, req);
947 		if (error)
948 			return (error);
949 	}
950 	return (0);
951 }
952 
953 SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD,
954     0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
955 
956 static int msgbuf_clearflag;
957 
958 static int
959 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
960 {
961 	int error;
962 	error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
963 	if (!error && req->newptr) {
964 		msgbuf_clear(msgbufp);
965 		msgbuf_clearflag = 0;
966 	}
967 	return (error);
968 }
969 
970 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
971     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clearflag, 0,
972     sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer");
973 
974 #ifdef DDB
975 
976 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
977 {
978 	int i, j;
979 
980 	if (!msgbufmapped) {
981 		db_printf("msgbuf not mapped yet\n");
982 		return;
983 	}
984 	db_printf("msgbufp = %p\n", msgbufp);
985 	db_printf("magic = %x, size = %d, r= %u, w = %u, ptr = %p, cksum= %u\n",
986 	    msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_rseq,
987 	    msgbufp->msg_wseq, msgbufp->msg_ptr, msgbufp->msg_cksum);
988 	for (i = 0; i < msgbufp->msg_size && !db_pager_quit; i++) {
989 		j = MSGBUF_SEQ_TO_POS(msgbufp, i + msgbufp->msg_rseq);
990 		db_printf("%c", msgbufp->msg_ptr[j]);
991 	}
992 	db_printf("\n");
993 }
994 
995 #endif /* DDB */
996 
997 void
998 hexdump(const void *ptr, int length, const char *hdr, int flags)
999 {
1000 	int i, j, k;
1001 	int cols;
1002 	const unsigned char *cp;
1003 	char delim;
1004 
1005 	if ((flags & HD_DELIM_MASK) != 0)
1006 		delim = (flags & HD_DELIM_MASK) >> 8;
1007 	else
1008 		delim = ' ';
1009 
1010 	if ((flags & HD_COLUMN_MASK) != 0)
1011 		cols = flags & HD_COLUMN_MASK;
1012 	else
1013 		cols = 16;
1014 
1015 	cp = ptr;
1016 	for (i = 0; i < length; i+= cols) {
1017 		if (hdr != NULL)
1018 			printf("%s", hdr);
1019 
1020 		if ((flags & HD_OMIT_COUNT) == 0)
1021 			printf("%04x  ", i);
1022 
1023 		if ((flags & HD_OMIT_HEX) == 0) {
1024 			for (j = 0; j < cols; j++) {
1025 				k = i + j;
1026 				if (k < length)
1027 					printf("%c%02x", delim, cp[k]);
1028 				else
1029 					printf("   ");
1030 			}
1031 		}
1032 
1033 		if ((flags & HD_OMIT_CHARS) == 0) {
1034 			printf("  |");
1035 			for (j = 0; j < cols; j++) {
1036 				k = i + j;
1037 				if (k >= length)
1038 					printf(" ");
1039 				else if (cp[k] >= ' ' && cp[k] <= '~')
1040 					printf("%c", cp[k]);
1041 				else
1042 					printf(".");
1043 			}
1044 			printf("|");
1045 		}
1046 		printf("\n");
1047 	}
1048 }
1049 
1050