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snprintb.c revision 1.5.6.1
      1 /*	$NetBSD: snprintb.c,v 1.5.6.1 2012/04/17 00:01:40 yamt Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2002 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 /*
     30  * snprintb: print an interpreted bitmask to a buffer
     31  *
     32  * => returns the length of the buffer that would be required to print the
     33  *    string minus the terminating NUL.
     34  */
     35 #ifndef _STANDALONE
     36 # ifndef _KERNEL
     37 
     38 #  if HAVE_NBTOOL_CONFIG_H
     39 #   include "nbtool_config.h"
     40 #  endif
     41 
     42 #  include <sys/cdefs.h>
     43 #  if defined(LIBC_SCCS) && !defined(lint)
     44 __RCSID("$NetBSD: snprintb.c,v 1.5.6.1 2012/04/17 00:01:40 yamt Exp $");
     45 #  endif
     46 
     47 #  include <sys/types.h>
     48 #  include <sys/inttypes.h>
     49 #  include <stdio.h>
     50 #  include <util.h>
     51 #  include <errno.h>
     52 # else
     53 #  include <sys/cdefs.h>
     54 __KERNEL_RCSID(0, "$NetBSD: snprintb.c,v 1.5.6.1 2012/04/17 00:01:40 yamt Exp $");
     55 #  include <sys/param.h>
     56 #  include <sys/inttypes.h>
     57 #  include <sys/systm.h>
     58 #  include <lib/libkern/libkern.h>
     59 # endif
     60 
     61 int
     62 snprintb_m(char *buf, size_t buflen, const char *bitfmt, uint64_t val,
     63 	   size_t l_max)
     64 {
     65 	char *bp = buf, *s_bp = NULL;
     66 	const char *c_fmt, *s_fmt = NULL, *cur_fmt;
     67 	const char *sbase;
     68 	int bit, ch, t_len, s_len = 0, l_len, f_len, v_len, sep;
     69 	int restart = 0;
     70 	uint64_t field;
     71 
     72 #ifdef _KERNEL
     73 	/*
     74 	 * For safety; no other *s*printf() do this, but in the kernel
     75 	 * we don't usually check the return value
     76 	 */
     77 	(void)memset(buf, 0, buflen);
     78 #endif /* _KERNEL */
     79 
     80 	ch = *bitfmt++;
     81 	switch (ch != '\177' ? ch : *bitfmt++) {
     82 	case 8:
     83 		sbase = "0%" PRIo64;
     84 		break;
     85 	case 10:
     86 		sbase = "%" PRId64;
     87 		break;
     88 	case 16:
     89 		sbase = "0x%" PRIx64;
     90 		break;
     91 	default:
     92 		goto internal;
     93 	}
     94 
     95 	/* Reserve space for trailing blank line if needed */
     96 	if (l_max > 0)
     97 		buflen--;
     98 
     99 	t_len = snprintf(bp, buflen, sbase, val);
    100 	if (t_len < 0)
    101 		goto internal;
    102 
    103 	v_len = l_len = t_len;
    104 
    105 	if ((size_t)t_len < buflen)
    106 		bp += t_len;
    107 	else
    108 		bp += buflen - 1;
    109 
    110 	/*
    111 	 * If the value we printed was 0 and we're using the old-style format,
    112 	 * we're done.
    113 	 */
    114 	if ((val == 0) && (ch != '\177'))
    115 		goto terminate;
    116 
    117 #define STORE(c) { l_len++;						\
    118 		   if ((size_t)(++t_len) < buflen)			\
    119 		   	*bp++ = (c);					\
    120 		 } while ( /* CONSTCOND */ 0)
    121 
    122 #define	BACKUP	{ if (s_bp != NULL) {					\
    123 			bp = s_bp; s_bp = NULL;				\
    124 			t_len -= l_len - s_len;				\
    125 			restart = 1;					\
    126 			bitfmt = s_fmt;					\
    127 		  }							\
    128 		  STORE('>'); STORE('\0');				\
    129 		  if ((size_t)t_len < buflen)				\
    130 			snprintf(bp, buflen - t_len, sbase, val);	\
    131 		  t_len += v_len; l_len = v_len; bp += v_len;		\
    132 		} while ( /* CONSTCOND */ 0)
    133 
    134 #define	PUTSEP								\
    135 		if (l_max > 0 && (size_t)l_len >= l_max) {		\
    136 			BACKUP;						\
    137 			STORE('<');					\
    138 		} else {						\
    139 			/* Remember separator location */		\
    140 			if (l_max > 0 && sep != '<') {			\
    141 				s_len = l_len;				\
    142 				s_bp  = bp;				\
    143 				s_fmt = cur_fmt;			\
    144 			}						\
    145 			STORE(sep);					\
    146 			restart = 0;					\
    147 		}							\
    148 
    149 #define	PUTCHR(c)							\
    150 		if (l_max > 0 && (size_t)l_len >= (l_max - 1)) {	\
    151 			BACKUP;						\
    152 			if (restart == 0) {				\
    153 				STORE(c);				\
    154 			} else						\
    155 				sep = '<';				\
    156 		} else {						\
    157 			STORE(c);					\
    158 			restart = 0;					\
    159 		}							\
    160 
    161 #define PUTS(s) while ((ch = *(s)++) != 0) {				\
    162 			PUTCHR(ch);					\
    163 			if (restart)					\
    164 				break;					\
    165 		}
    166 
    167 	/*
    168 	 * Chris Torek's new bitmask format is identified by a leading \177
    169 	 */
    170 	sep = '<';
    171 	if (ch != '\177') {
    172 		/* old (standard) format. */
    173 		for (;(bit = *bitfmt) != 0;) {
    174 			cur_fmt = bitfmt++;
    175 			if (val & (1 << (bit - 1))) {
    176 				PUTSEP;
    177 				if (restart)
    178 					continue;
    179 				sep = ',';
    180 				for (; (ch = *bitfmt) > ' '; ++bitfmt) {
    181 					PUTCHR(ch);
    182 					if (restart)
    183 						break;
    184 				}
    185 			} else
    186 				for (; *bitfmt > ' '; ++bitfmt)
    187 					continue;
    188 		}
    189 	} else {
    190 		/* new quad-capable format; also does fields. */
    191 		field = val;
    192 		while (c_fmt = bitfmt, (ch = *bitfmt++) != '\0') {
    193 			bit = *bitfmt++;	/* now 0-origin */
    194 			switch (ch) {
    195 			case 'b':
    196 				if (((u_int)(val >> bit) & 1) == 0)
    197 					goto skip;
    198 				cur_fmt = c_fmt;
    199 				PUTSEP;
    200 				if (restart)
    201 					break;
    202 				PUTS(bitfmt);
    203 				if (restart == 0)
    204 					sep = ',';
    205 				break;
    206 			case 'f':
    207 			case 'F':
    208 				cur_fmt = c_fmt;
    209 				f_len = *bitfmt++;	/* field length */
    210 				field = (val >> bit) &
    211 					    (((uint64_t)1 << f_len) - 1);
    212 				PUTSEP;
    213 				if (restart == 0)
    214 					sep = ',';
    215 				if (ch == 'F')	/* just extract */
    216 					break;
    217 				if (restart == 0) {
    218 					PUTS(bitfmt);
    219 					PUTCHR('=');
    220 				}
    221 				if (restart == 0) {
    222 					f_len = snprintf(bp, buflen - t_len,
    223 							 sbase, field);
    224 					if (f_len < 0)
    225 						goto internal;
    226 					t_len += f_len;
    227 					l_len += f_len;
    228 					if ((size_t)t_len < buflen)
    229 						bp += f_len;
    230 					if (l_max > 0 &&
    231 					    (size_t)l_len > l_max) {
    232 						PUTCHR('#');
    233 					}
    234 				}
    235 				break;
    236 			case '=':
    237 			case ':':
    238 				/*
    239 				 * Here "bit" is actually a value instead,
    240 				 * to be compared against the last field.
    241 				 * This only works for values in [0..255],
    242 				 * of course.
    243 				 */
    244 				if ((int)field != bit)
    245 					goto skip;
    246 				if (ch == '=') {
    247 					PUTCHR('=');
    248 				}
    249 				PUTS(bitfmt);
    250 				break;
    251 			default:
    252 			skip:
    253 				while (*bitfmt++ != '\0')
    254 					continue;
    255 				break;
    256 			}
    257 		}
    258 	}
    259 	l_len++;
    260 	if ((size_t)(++t_len) < buflen)
    261 		*bp++ = '>';
    262 terminate:
    263 	*bp++ = '\0';
    264 	if (l_max != 0) {
    265 		t_len++;
    266 		*bp = '\0';
    267 	}
    268 	return t_len;
    269 internal:
    270 #ifndef _KERNEL
    271 	errno = EINVAL;
    272 #endif
    273 	return -1;
    274 }
    275 
    276 int
    277 snprintb(char *buf, size_t buflen, const char *bitfmt, uint64_t val)
    278 {
    279 	return snprintb_m(buf, buflen, bitfmt, val, 0);
    280 }
    281 #endif
    282