xref: /freebsd/sys/kern/subr_prf.c (revision 13de33a5dc2304b13d595d75d48c51793958474f)
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 		sx_sunlock(&proctree_lock);
155 		return (0);
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 		sx_sunlock(&proctree_lock);
163 		return (0);
164 	}
165 	pca.flags = TOTTY;
166 	pca.p_bufr = NULL;
167 	va_start(ap, fmt);
168 	tty_lock(pca.tty);
169 	sx_sunlock(&proctree_lock);
170 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
171 	tty_unlock(pca.tty);
172 	va_end(ap);
173 	return (retval);
174 }
175 
176 /*
177  * tprintf and vtprintf print on the controlling terminal associated with the
178  * given session, possibly to the log as well.
179  */
180 void
181 tprintf(struct proc *p, int pri, const char *fmt, ...)
182 {
183 	va_list ap;
184 
185 	va_start(ap, fmt);
186 	vtprintf(p, pri, fmt, ap);
187 	va_end(ap);
188 }
189 
190 void
191 vtprintf(struct proc *p, int pri, const char *fmt, va_list ap)
192 {
193 	struct tty *tp = NULL;
194 	int flags = 0;
195 	struct putchar_arg pca;
196 	struct session *sess = NULL;
197 
198 	sx_slock(&proctree_lock);
199 	if (pri != -1)
200 		flags |= TOLOG;
201 	if (p != NULL) {
202 		PROC_LOCK(p);
203 		if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
204 			sess = p->p_session;
205 			sess_hold(sess);
206 			PROC_UNLOCK(p);
207 			tp = sess->s_ttyp;
208 			if (tp != NULL && tty_checkoutq(tp))
209 				flags |= TOTTY;
210 			else
211 				tp = NULL;
212 		} else
213 			PROC_UNLOCK(p);
214 	}
215 	pca.pri = pri;
216 	pca.tty = tp;
217 	pca.flags = flags;
218 	pca.p_bufr = NULL;
219 	if (pca.tty != NULL)
220 		tty_lock(pca.tty);
221 	sx_sunlock(&proctree_lock);
222 	kvprintf(fmt, putchar, &pca, 10, ap);
223 	if (pca.tty != NULL)
224 		tty_unlock(pca.tty);
225 	if (sess != NULL)
226 		sess_release(sess);
227 	msgbuftrigger = 1;
228 }
229 
230 /*
231  * Ttyprintf displays a message on a tty; it should be used only by
232  * the tty driver, or anything that knows the underlying tty will not
233  * be revoke(2)'d away.  Other callers should use tprintf.
234  */
235 int
236 ttyprintf(struct tty *tp, const char *fmt, ...)
237 {
238 	va_list ap;
239 	struct putchar_arg pca;
240 	int retval;
241 
242 	va_start(ap, fmt);
243 	pca.tty = tp;
244 	pca.flags = TOTTY;
245 	pca.p_bufr = NULL;
246 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
247 	va_end(ap);
248 	return (retval);
249 }
250 
251 /*
252  * Log writes to the log buffer, and guarantees not to sleep (so can be
253  * called by interrupt routines).  If there is no process reading the
254  * log yet, it writes to the console also.
255  */
256 void
257 log(int level, const char *fmt, ...)
258 {
259 	va_list ap;
260 	struct putchar_arg pca;
261 #ifdef PRINTF_BUFR_SIZE
262 	char bufr[PRINTF_BUFR_SIZE];
263 #endif
264 
265 	pca.tty = NULL;
266 	pca.pri = level;
267 	pca.flags = log_open ? TOLOG : TOCONS;
268 #ifdef PRINTF_BUFR_SIZE
269 	pca.p_bufr = bufr;
270 	pca.p_next = pca.p_bufr;
271 	pca.n_bufr = sizeof(bufr);
272 	pca.remain = sizeof(bufr);
273 	*pca.p_next = '\0';
274 #else
275 	pca.p_bufr = NULL;
276 #endif
277 
278 	va_start(ap, fmt);
279 	kvprintf(fmt, putchar, &pca, 10, ap);
280 	va_end(ap);
281 
282 #ifdef PRINTF_BUFR_SIZE
283 	/* Write any buffered console/log output: */
284 	if (*pca.p_bufr != '\0') {
285 		if (pca.flags & TOLOG)
286 			msglogstr(pca.p_bufr, level, /*filter_cr*/1);
287 
288 		if (pca.flags & TOCONS)
289 			cnputs(pca.p_bufr);
290 	}
291 #endif
292 	msgbuftrigger = 1;
293 }
294 
295 #define CONSCHUNK 128
296 
297 void
298 log_console(struct uio *uio)
299 {
300 	int c, error, nl;
301 	char *consbuffer;
302 	int pri;
303 
304 	if (!log_console_output)
305 		return;
306 
307 	pri = LOG_INFO | LOG_CONSOLE;
308 	uio = cloneuio(uio);
309 	consbuffer = malloc(CONSCHUNK, M_TEMP, M_WAITOK);
310 
311 	nl = 0;
312 	while (uio->uio_resid > 0) {
313 		c = imin(uio->uio_resid, CONSCHUNK - 1);
314 		error = uiomove(consbuffer, c, uio);
315 		if (error != 0)
316 			break;
317 		/* Make sure we're NUL-terminated */
318 		consbuffer[c] = '\0';
319 		if (consbuffer[c - 1] == '\n')
320 			nl = 1;
321 		else
322 			nl = 0;
323 		msglogstr(consbuffer, pri, /*filter_cr*/ 1);
324 	}
325 	/*
326 	 * The previous behavior in log_console() is preserved when
327 	 * log_console_add_linefeed is non-zero.  For that behavior, if an
328 	 * individual console write came in that was not terminated with a
329 	 * line feed, it would add a line feed.
330 	 *
331 	 * This results in different data in the message buffer than
332 	 * appears on the system console (which doesn't add extra line feed
333 	 * characters).
334 	 *
335 	 * A number of programs and rc scripts write a line feed, or a period
336 	 * and a line feed when they have completed their operation.  On
337 	 * the console, this looks seamless, but when displayed with
338 	 * 'dmesg -a', you wind up with output that looks like this:
339 	 *
340 	 * Updating motd:
341 	 * .
342 	 *
343 	 * On the console, it looks like this:
344 	 * Updating motd:.
345 	 *
346 	 * We could add logic to detect that situation, or just not insert
347 	 * the extra newlines.  Set the kern.log_console_add_linefeed
348 	 * sysctl/tunable variable to get the old behavior.
349 	 */
350 	if (!nl && log_console_add_linefeed) {
351 		consbuffer[0] = '\n';
352 		consbuffer[1] = '\0';
353 		msglogstr(consbuffer, pri, /*filter_cr*/ 1);
354 	}
355 	msgbuftrigger = 1;
356 	free(uio, M_IOV);
357 	free(consbuffer, M_TEMP);
358 	return;
359 }
360 
361 int
362 printf(const char *fmt, ...)
363 {
364 	va_list ap;
365 	int retval;
366 
367 	va_start(ap, fmt);
368 	retval = vprintf(fmt, ap);
369 	va_end(ap);
370 
371 	return (retval);
372 }
373 
374 int
375 vprintf(const char *fmt, va_list ap)
376 {
377 	struct putchar_arg pca;
378 	int retval;
379 #ifdef PRINTF_BUFR_SIZE
380 	char bufr[PRINTF_BUFR_SIZE];
381 #endif
382 
383 	pca.tty = NULL;
384 	pca.flags = TOCONS | TOLOG;
385 	pca.pri = -1;
386 #ifdef PRINTF_BUFR_SIZE
387 	pca.p_bufr = bufr;
388 	pca.p_next = pca.p_bufr;
389 	pca.n_bufr = sizeof(bufr);
390 	pca.remain = sizeof(bufr);
391 	*pca.p_next = '\0';
392 #else
393 	/* Don't buffer console output. */
394 	pca.p_bufr = NULL;
395 #endif
396 
397 	retval = kvprintf(fmt, putchar, &pca, 10, ap);
398 
399 #ifdef PRINTF_BUFR_SIZE
400 	/* Write any buffered console/log output: */
401 	if (*pca.p_bufr != '\0') {
402 		cnputs(pca.p_bufr);
403 		msglogstr(pca.p_bufr, pca.pri, /*filter_cr*/ 1);
404 	}
405 #endif
406 
407 	if (!panicstr)
408 		msgbuftrigger = 1;
409 
410 	return (retval);
411 }
412 
413 static void
414 putbuf(int c, struct putchar_arg *ap)
415 {
416 	/* Check if no console output buffer was provided. */
417 	if (ap->p_bufr == NULL) {
418 		/* Output direct to the console. */
419 		if (ap->flags & TOCONS)
420 			cnputc(c);
421 
422 		if (ap->flags & TOLOG)
423 			msglogchar(c, ap->pri);
424 	} else {
425 		/* Buffer the character: */
426 		*ap->p_next++ = c;
427 		ap->remain--;
428 
429 		/* Always leave the buffer zero terminated. */
430 		*ap->p_next = '\0';
431 
432 		/* Check if the buffer needs to be flushed. */
433 		if (ap->remain == 2 || c == '\n') {
434 
435 			if (ap->flags & TOLOG)
436 				msglogstr(ap->p_bufr, ap->pri, /*filter_cr*/1);
437 
438 			if (ap->flags & TOCONS) {
439 				if ((panicstr == NULL) && (constty != NULL))
440 					msgbuf_addstr(&consmsgbuf, -1,
441 					    ap->p_bufr, /*filter_cr*/ 0);
442 
443 				if ((constty == NULL) ||(always_console_output))
444 					cnputs(ap->p_bufr);
445 			}
446 
447 			ap->p_next = ap->p_bufr;
448 			ap->remain = ap->n_bufr;
449 			*ap->p_next = '\0';
450 		}
451 
452 		/*
453 		 * Since we fill the buffer up one character at a time,
454 		 * this should not happen.  We should always catch it when
455 		 * ap->remain == 2 (if not sooner due to a newline), flush
456 		 * the buffer and move on.  One way this could happen is
457 		 * if someone sets PRINTF_BUFR_SIZE to 1 or something
458 		 * similarly silly.
459 		 */
460 		KASSERT(ap->remain > 2, ("Bad buffer logic, remain = %zd",
461 		    ap->remain));
462 	}
463 }
464 
465 /*
466  * Print a character on console or users terminal.  If destination is
467  * the console then the last bunch of characters are saved in msgbuf for
468  * inspection later.
469  */
470 static void
471 putchar(int c, void *arg)
472 {
473 	struct putchar_arg *ap = (struct putchar_arg*) arg;
474 	struct tty *tp = ap->tty;
475 	int flags = ap->flags;
476 
477 	/* Don't use the tty code after a panic or while in ddb. */
478 	if (kdb_active) {
479 		if (c != '\0')
480 			cnputc(c);
481 		return;
482 	}
483 
484 	if ((flags & TOTTY) && tp != NULL && panicstr == NULL)
485 		tty_putchar(tp, c);
486 
487 	if ((flags & (TOCONS | TOLOG)) && c != '\0')
488 		putbuf(c, ap);
489 }
490 
491 /*
492  * Scaled down version of sprintf(3).
493  */
494 int
495 sprintf(char *buf, const char *cfmt, ...)
496 {
497 	int retval;
498 	va_list ap;
499 
500 	va_start(ap, cfmt);
501 	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
502 	buf[retval] = '\0';
503 	va_end(ap);
504 	return (retval);
505 }
506 
507 /*
508  * Scaled down version of vsprintf(3).
509  */
510 int
511 vsprintf(char *buf, const char *cfmt, va_list ap)
512 {
513 	int retval;
514 
515 	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
516 	buf[retval] = '\0';
517 	return (retval);
518 }
519 
520 /*
521  * Scaled down version of snprintf(3).
522  */
523 int
524 snprintf(char *str, size_t size, const char *format, ...)
525 {
526 	int retval;
527 	va_list ap;
528 
529 	va_start(ap, format);
530 	retval = vsnprintf(str, size, format, ap);
531 	va_end(ap);
532 	return(retval);
533 }
534 
535 /*
536  * Scaled down version of vsnprintf(3).
537  */
538 int
539 vsnprintf(char *str, size_t size, 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, 10, ap);
547 	if (info.remain >= 1)
548 		*info.str++ = '\0';
549 	return (retval);
550 }
551 
552 /*
553  * Kernel version which takes radix argument vsnprintf(3).
554  */
555 int
556 vsnrprintf(char *str, size_t size, int radix, const char *format, va_list ap)
557 {
558 	struct snprintf_arg info;
559 	int retval;
560 
561 	info.str = str;
562 	info.remain = size;
563 	retval = kvprintf(format, snprintf_func, &info, radix, ap);
564 	if (info.remain >= 1)
565 		*info.str++ = '\0';
566 	return (retval);
567 }
568 
569 static void
570 snprintf_func(int ch, void *arg)
571 {
572 	struct snprintf_arg *const info = arg;
573 
574 	if (info->remain >= 2) {
575 		*info->str++ = ch;
576 		info->remain--;
577 	}
578 }
579 
580 /*
581  * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
582  * order; return an optional length and a pointer to the last character
583  * written in the buffer (i.e., the first character of the string).
584  * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
585  */
586 static char *
587 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
588 {
589 	char *p, c;
590 
591 	p = nbuf;
592 	*p = '\0';
593 	do {
594 		c = hex2ascii(num % base);
595 		*++p = upper ? toupper(c) : c;
596 	} while (num /= base);
597 	if (lenp)
598 		*lenp = p - nbuf;
599 	return (p);
600 }
601 
602 /*
603  * Scaled down version of printf(3).
604  *
605  * Two additional formats:
606  *
607  * The format %b is supported to decode error registers.
608  * Its usage is:
609  *
610  *	printf("reg=%b\n", regval, "<base><arg>*");
611  *
612  * where <base> is the output base expressed as a control character, e.g.
613  * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
614  * the first of which gives the bit number to be inspected (origin 1), and
615  * the next characters (up to a control character, i.e. a character <= 32),
616  * give the name of the register.  Thus:
617  *
618  *	kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
619  *
620  * would produce output:
621  *
622  *	reg=3<BITTWO,BITONE>
623  *
624  * XXX:  %D  -- Hexdump, takes pointer and separator string:
625  *		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
626  *		("%*D", len, ptr, " " -> XX XX XX XX ...
627  */
628 int
629 kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap)
630 {
631 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; }
632 	char nbuf[MAXNBUF];
633 	char *d;
634 	const char *p, *percent, *q;
635 	u_char *up;
636 	int ch, n;
637 	uintmax_t num;
638 	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
639 	int cflag, hflag, jflag, tflag, zflag;
640 	int dwidth, upper;
641 	char padc;
642 	int stop = 0, retval = 0;
643 
644 	num = 0;
645 	if (!func)
646 		d = (char *) arg;
647 	else
648 		d = NULL;
649 
650 	if (fmt == NULL)
651 		fmt = "(fmt null)\n";
652 
653 	if (radix < 2 || radix > 36)
654 		radix = 10;
655 
656 	for (;;) {
657 		padc = ' ';
658 		width = 0;
659 		while ((ch = (u_char)*fmt++) != '%' || stop) {
660 			if (ch == '\0')
661 				return (retval);
662 			PCHAR(ch);
663 		}
664 		percent = fmt - 1;
665 		qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
666 		sign = 0; dot = 0; dwidth = 0; upper = 0;
667 		cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
668 reswitch:	switch (ch = (u_char)*fmt++) {
669 		case '.':
670 			dot = 1;
671 			goto reswitch;
672 		case '#':
673 			sharpflag = 1;
674 			goto reswitch;
675 		case '+':
676 			sign = 1;
677 			goto reswitch;
678 		case '-':
679 			ladjust = 1;
680 			goto reswitch;
681 		case '%':
682 			PCHAR(ch);
683 			break;
684 		case '*':
685 			if (!dot) {
686 				width = va_arg(ap, int);
687 				if (width < 0) {
688 					ladjust = !ladjust;
689 					width = -width;
690 				}
691 			} else {
692 				dwidth = va_arg(ap, int);
693 			}
694 			goto reswitch;
695 		case '0':
696 			if (!dot) {
697 				padc = '0';
698 				goto reswitch;
699 			}
700 		case '1': case '2': case '3': case '4':
701 		case '5': case '6': case '7': case '8': case '9':
702 				for (n = 0;; ++fmt) {
703 					n = n * 10 + ch - '0';
704 					ch = *fmt;
705 					if (ch < '0' || ch > '9')
706 						break;
707 				}
708 			if (dot)
709 				dwidth = n;
710 			else
711 				width = n;
712 			goto reswitch;
713 		case 'b':
714 			num = (u_int)va_arg(ap, int);
715 			p = va_arg(ap, char *);
716 			for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
717 				PCHAR(*q--);
718 
719 			if (num == 0)
720 				break;
721 
722 			for (tmp = 0; *p;) {
723 				n = *p++;
724 				if (num & (1 << (n - 1))) {
725 					PCHAR(tmp ? ',' : '<');
726 					for (; (n = *p) > ' '; ++p)
727 						PCHAR(n);
728 					tmp = 1;
729 				} else
730 					for (; *p > ' '; ++p)
731 						continue;
732 			}
733 			if (tmp)
734 				PCHAR('>');
735 			break;
736 		case 'c':
737 			PCHAR(va_arg(ap, int));
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 			goto number;
866 handle_sign:
867 			if (jflag)
868 				num = va_arg(ap, intmax_t);
869 			else if (qflag)
870 				num = va_arg(ap, quad_t);
871 			else if (tflag)
872 				num = va_arg(ap, ptrdiff_t);
873 			else if (lflag)
874 				num = va_arg(ap, long);
875 			else if (zflag)
876 				num = va_arg(ap, ssize_t);
877 			else if (hflag)
878 				num = (short)va_arg(ap, int);
879 			else if (cflag)
880 				num = (char)va_arg(ap, int);
881 			else
882 				num = va_arg(ap, int);
883 number:
884 			if (sign && (intmax_t)num < 0) {
885 				neg = 1;
886 				num = -(intmax_t)num;
887 			}
888 			p = ksprintn(nbuf, num, base, &n, upper);
889 			tmp = 0;
890 			if (sharpflag && num != 0) {
891 				if (base == 8)
892 					tmp++;
893 				else if (base == 16)
894 					tmp += 2;
895 			}
896 			if (neg)
897 				tmp++;
898 
899 			if (!ladjust && padc == '0')
900 				dwidth = width - tmp;
901 			width -= tmp + imax(dwidth, n);
902 			dwidth -= n;
903 			if (!ladjust)
904 				while (width-- > 0)
905 					PCHAR(' ');
906 			if (neg)
907 				PCHAR('-');
908 			if (sharpflag && num != 0) {
909 				if (base == 8) {
910 					PCHAR('0');
911 				} else if (base == 16) {
912 					PCHAR('0');
913 					PCHAR('x');
914 				}
915 			}
916 			while (dwidth-- > 0)
917 				PCHAR('0');
918 
919 			while (*p)
920 				PCHAR(*p--);
921 
922 			if (ladjust)
923 				while (width-- > 0)
924 					PCHAR(' ');
925 
926 			break;
927 		default:
928 			while (percent < fmt)
929 				PCHAR(*percent++);
930 			/*
931 			 * Since we ignore an formatting argument it is no
932 			 * longer safe to obey the remaining formatting
933 			 * arguments as the arguments will no longer match
934 			 * the format specs.
935 			 */
936 			stop = 1;
937 			break;
938 		}
939 	}
940 #undef PCHAR
941 }
942 
943 /*
944  * Put character in log buffer with a particular priority.
945  */
946 static void
947 msglogchar(int c, int pri)
948 {
949 	static int lastpri = -1;
950 	static int dangling;
951 	char nbuf[MAXNBUF];
952 	char *p;
953 
954 	if (!msgbufmapped)
955 		return;
956 	if (c == '\0' || c == '\r')
957 		return;
958 	if (pri != -1 && pri != lastpri) {
959 		if (dangling) {
960 			msgbuf_addchar(msgbufp, '\n');
961 			dangling = 0;
962 		}
963 		msgbuf_addchar(msgbufp, '<');
964 		for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL, 0); *p;)
965 			msgbuf_addchar(msgbufp, *p--);
966 		msgbuf_addchar(msgbufp, '>');
967 		lastpri = pri;
968 	}
969 	msgbuf_addchar(msgbufp, c);
970 	if (c == '\n') {
971 		dangling = 0;
972 		lastpri = -1;
973 	} else {
974 		dangling = 1;
975 	}
976 }
977 
978 static void
979 msglogstr(char *str, int pri, int filter_cr)
980 {
981 	if (!msgbufmapped)
982 		return;
983 
984 	msgbuf_addstr(msgbufp, pri, str, filter_cr);
985 }
986 
987 void
988 msgbufinit(void *ptr, int size)
989 {
990 	char *cp;
991 	static struct msgbuf *oldp = NULL;
992 
993 	size -= sizeof(*msgbufp);
994 	cp = (char *)ptr;
995 	msgbufp = (struct msgbuf *)(cp + size);
996 	msgbuf_reinit(msgbufp, cp, size);
997 	if (msgbufmapped && oldp != msgbufp)
998 		msgbuf_copy(oldp, msgbufp);
999 	msgbufmapped = 1;
1000 	oldp = msgbufp;
1001 }
1002 
1003 static int unprivileged_read_msgbuf = 1;
1004 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_read_msgbuf,
1005     CTLFLAG_RW, &unprivileged_read_msgbuf, 0,
1006     "Unprivileged processes may read the kernel message buffer");
1007 
1008 /* Sysctls for accessing/clearing the msgbuf */
1009 static int
1010 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
1011 {
1012 	char buf[128];
1013 	u_int seq;
1014 	int error, len;
1015 
1016 	if (!unprivileged_read_msgbuf) {
1017 		error = priv_check(req->td, PRIV_MSGBUF);
1018 		if (error)
1019 			return (error);
1020 	}
1021 
1022 	/* Read the whole buffer, one chunk at a time. */
1023 	mtx_lock(&msgbuf_lock);
1024 	msgbuf_peekbytes(msgbufp, NULL, 0, &seq);
1025 	for (;;) {
1026 		len = msgbuf_peekbytes(msgbufp, buf, sizeof(buf), &seq);
1027 		mtx_unlock(&msgbuf_lock);
1028 		if (len == 0)
1029 			return (0);
1030 
1031 		error = sysctl_handle_opaque(oidp, buf, len, req);
1032 		if (error)
1033 			return (error);
1034 
1035 		mtx_lock(&msgbuf_lock);
1036 	}
1037 }
1038 
1039 SYSCTL_PROC(_kern, OID_AUTO, msgbuf,
1040     CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
1041     NULL, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
1042 
1043 static int msgbuf_clearflag;
1044 
1045 static int
1046 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
1047 {
1048 	int error;
1049 	error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
1050 	if (!error && req->newptr) {
1051 		mtx_lock(&msgbuf_lock);
1052 		msgbuf_clear(msgbufp);
1053 		mtx_unlock(&msgbuf_lock);
1054 		msgbuf_clearflag = 0;
1055 	}
1056 	return (error);
1057 }
1058 
1059 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
1060     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE | CTLFLAG_MPSAFE,
1061     &msgbuf_clearflag, 0, sysctl_kern_msgbuf_clear, "I",
1062     "Clear kernel message buffer");
1063 
1064 #ifdef DDB
1065 
1066 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
1067 {
1068 	int i, j;
1069 
1070 	if (!msgbufmapped) {
1071 		db_printf("msgbuf not mapped yet\n");
1072 		return;
1073 	}
1074 	db_printf("msgbufp = %p\n", msgbufp);
1075 	db_printf("magic = %x, size = %d, r= %u, w = %u, ptr = %p, cksum= %u\n",
1076 	    msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_rseq,
1077 	    msgbufp->msg_wseq, msgbufp->msg_ptr, msgbufp->msg_cksum);
1078 	for (i = 0; i < msgbufp->msg_size && !db_pager_quit; i++) {
1079 		j = MSGBUF_SEQ_TO_POS(msgbufp, i + msgbufp->msg_rseq);
1080 		db_printf("%c", msgbufp->msg_ptr[j]);
1081 	}
1082 	db_printf("\n");
1083 }
1084 
1085 #endif /* DDB */
1086 
1087 void
1088 hexdump(const void *ptr, int length, const char *hdr, int flags)
1089 {
1090 	int i, j, k;
1091 	int cols;
1092 	const unsigned char *cp;
1093 	char delim;
1094 
1095 	if ((flags & HD_DELIM_MASK) != 0)
1096 		delim = (flags & HD_DELIM_MASK) >> 8;
1097 	else
1098 		delim = ' ';
1099 
1100 	if ((flags & HD_COLUMN_MASK) != 0)
1101 		cols = flags & HD_COLUMN_MASK;
1102 	else
1103 		cols = 16;
1104 
1105 	cp = ptr;
1106 	for (i = 0; i < length; i+= cols) {
1107 		if (hdr != NULL)
1108 			printf("%s", hdr);
1109 
1110 		if ((flags & HD_OMIT_COUNT) == 0)
1111 			printf("%04x  ", i);
1112 
1113 		if ((flags & HD_OMIT_HEX) == 0) {
1114 			for (j = 0; j < cols; j++) {
1115 				k = i + j;
1116 				if (k < length)
1117 					printf("%c%02x", delim, cp[k]);
1118 				else
1119 					printf("   ");
1120 			}
1121 		}
1122 
1123 		if ((flags & HD_OMIT_CHARS) == 0) {
1124 			printf("  |");
1125 			for (j = 0; j < cols; j++) {
1126 				k = i + j;
1127 				if (k >= length)
1128 					printf(" ");
1129 				else if (cp[k] >= ' ' && cp[k] <= '~')
1130 					printf("%c", cp[k]);
1131 				else
1132 					printf(".");
1133 			}
1134 			printf("|");
1135 		}
1136 		printf("\n");
1137 	}
1138 }
1139 
1140