xref: /netbsd-src/common/lib/libutil/snprintb.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /*	$NetBSD: snprintb.c,v 1.18 2018/07/26 00:33:26 kamil 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 1.18 2018/07/26 00:33:26 kamil Exp $");
45 #  endif
46 
47 #  include <sys/types.h>
48 #  include <inttypes.h>
49 #  include <stdio.h>
50 #  include <util.h>
51 #  include <errno.h>
52 # else /* ! _KERNEL */
53 #  include <sys/cdefs.h>
54 __KERNEL_RCSID(0, "$NetBSD: snprintb.c,v 1.18 2018/07/26 00:33:26 kamil Exp $");
55 #  include <sys/param.h>
56 #  include <sys/inttypes.h>
57 #  include <sys/systm.h>
58 #  include <lib/libkern/libkern.h>
59 # endif /* ! _KERNEL */
60 
61 # ifndef HAVE_SNPRINTB_M
62 int
63 snprintb_m(char *buf, size_t buflen, const char *bitfmt, uint64_t val,
64 	   size_t l_max)
65 {
66 	char *bp = buf, *s_bp = NULL;
67 	const char *c_fmt, *s_fmt = NULL, *cur_fmt;
68 	const char *sbase;
69 	int bit, ch, t_len, s_len = 0, l_len, f_len, v_len, sep;
70 	int restart = 0;
71 	uint64_t field;
72 
73 #ifdef _KERNEL
74 	/*
75 	 * For safety; no other *s*printf() do this, but in the kernel
76 	 * we don't usually check the return value
77 	 */
78 	(void)memset(buf, 0, buflen);
79 #endif /* _KERNEL */
80 
81 	ch = *bitfmt++;
82 	switch (ch != '\177' ? ch : *bitfmt++) {
83 	case 8:
84 		sbase = "0%" PRIo64;
85 		break;
86 	case 10:
87 		sbase = "%" PRId64;
88 		break;
89 	case 16:
90 		sbase = "0x%" PRIx64;
91 		break;
92 	default:
93 		goto internal;
94 	}
95 
96 	/* Reserve space for trailing blank line if needed */
97 	if (l_max > 0)
98 		buflen--;
99 
100 	t_len = snprintf(bp, buflen, sbase, val);
101 	if (t_len < 0)
102 		goto internal;
103 
104 	v_len = l_len = t_len;
105 
106 	if ((size_t)t_len < buflen)
107 		bp += t_len;
108 	else
109 		bp += buflen - 1;
110 
111 	/*
112 	 * If the value we printed was 0 and we're using the old-style format,
113 	 * we're done.
114 	 */
115 	if ((val == 0) && (ch != '\177'))
116 		goto terminate;
117 
118 #define STORE(c) do { l_len++;						\
119 		   if ((size_t)(++t_len) < buflen)			\
120 		   	*bp++ = (c);					\
121 		 } while ( /* CONSTCOND */ 0)
122 
123 #define	BACKUP	do { if (s_bp != NULL) {				\
124 			bp = s_bp; s_bp = NULL;				\
125 			t_len -= l_len - s_len;				\
126 			restart = 1;					\
127 			bitfmt = s_fmt;					\
128 		  }							\
129 		  STORE('>'); STORE('\0');				\
130 		  if ((size_t)t_len < buflen)				\
131 			snprintf(bp, buflen - t_len, sbase, val);	\
132 		  t_len += v_len; l_len = v_len; bp += v_len;		\
133 		} while ( /* CONSTCOND */ 0)
134 
135 #define	PUTSEP do {							\
136 			if (l_max > 0 && (size_t)l_len >= l_max) {	\
137 				BACKUP;					\
138 				STORE('<');				\
139 			} else {					\
140 				/* Remember separator location */	\
141 				if (l_max > 0 && sep != '<') {		\
142 					s_len = l_len;			\
143 					s_bp  = bp;			\
144 					s_fmt = cur_fmt;		\
145 				}					\
146 				STORE(sep);				\
147 				restart = 0;				\
148 			}						\
149 		} while ( /* CONSTCOND */ 0)
150 
151 #define	PUTCHR(c) do {							\
152 			if (l_max > 0 && (size_t)l_len >= (l_max - 1)) {\
153 				BACKUP;					\
154 				if (restart == 0)			\
155 					STORE(c);			\
156 				else					\
157 					sep = '<';			\
158 			} else {					\
159 				STORE(c);				\
160 				restart = 0;				\
161 			}						\
162 		} while ( /* CONSTCOND */ 0)
163 
164 #define PUTS(s) while ((ch = *(s)++) != 0) {				\
165 			PUTCHR(ch);					\
166 			if (restart)					\
167 				break;					\
168 		}
169 
170 	/*
171 	 * Chris Torek's new bitmask format is identified by a leading \177
172 	 */
173 	sep = '<';
174 	if (ch != '\177') {
175 		/* old (standard) format. */
176 		for (;(bit = *bitfmt) != 0;) {
177 			cur_fmt = bitfmt++;
178 			if (val & (1U << (bit - 1))) {
179 				PUTSEP;
180 				if (restart)
181 					continue;
182 				sep = ',';
183 				for (; (ch = *bitfmt) > ' '; ++bitfmt) {
184 					PUTCHR(ch);
185 					if (restart)
186 						break;
187 				}
188 			} else
189 				for (; *bitfmt > ' '; ++bitfmt)
190 					continue;
191 		}
192 	} else {
193 		/* new quad-capable format; also does fields. */
194 		field = val;
195 		while (c_fmt = bitfmt, (ch = *bitfmt++) != '\0') {
196 			bit = *bitfmt++;	/* now 0-origin */
197 			switch (ch) {
198 			case 'b':
199 				if (((unsigned int)(val >> bit) & 1) == 0)
200 					goto skip;
201 				cur_fmt = c_fmt;
202 				PUTSEP;
203 				if (restart)
204 					break;
205 				PUTS(bitfmt);
206 				if (restart == 0)
207 					sep = ',';
208 				break;
209 			case 'f':
210 			case 'F':
211 				cur_fmt = c_fmt;
212 				f_len = *bitfmt++;	/* field length */
213 				field = (val >> bit) &
214 					    (((uint64_t)1 << f_len) - 1);
215 				PUTSEP;
216 				if (restart == 0)
217 					sep = ',';
218 				if (ch == 'F') {	/* just extract */
219 					bitfmt--;
220 					break;
221 				}
222 				if (restart == 0)
223 					PUTS(bitfmt);
224 				if (restart == 0)
225 					PUTCHR('=');
226 				if (restart == 0) {
227 					f_len = snprintf(bp, buflen - t_len,
228 							 sbase, field);
229 					if (f_len < 0)
230 						goto internal;
231 					t_len += f_len;
232 					l_len += f_len;
233 					if ((size_t)t_len < buflen)
234 						bp += f_len;
235 					if (l_max > 0 && (size_t)l_len > l_max)
236 						PUTCHR('#');
237 				}
238 				break;
239 			case '=':
240 			case ':':
241 				/*
242 				 * Here "bit" is actually a value instead,
243 				 * to be compared against the last field.
244 				 * This only works for values in [0..255],
245 				 * of course.
246 				 */
247 				if ((int)field != bit)
248 					goto skip;
249 				if (ch == '=')
250 					PUTCHR('=');
251 				PUTS(bitfmt);
252 				break;
253 			default:
254 			skip:
255 				while (*bitfmt++ != '\0')
256 					continue;
257 				break;
258 			}
259 		}
260 	}
261 	l_len++;
262 	if (sep != '<' && (size_t)(++t_len) < buflen)
263 		*bp++ = '>';
264 terminate:
265 	*bp++ = '\0';
266 	if (l_max != 0) {
267 		t_len++;
268 		*bp = '\0';
269 	}
270 	return t_len;
271 internal:
272 #ifndef _KERNEL
273 	errno = EINVAL;
274 #endif
275 	return -1;
276 }
277 
278 int
279 snprintb(char *buf, size_t buflen, const char *bitfmt, uint64_t val)
280 {
281 	return snprintb_m(buf, buflen, bitfmt, val, 0);
282 }
283 # endif /* ! HAVE_SNPRINTB_M */
284 #endif /* ! _STANDALONE */
285