1 /* $NetBSD: snprintb.c,v 1.22 2019/12/06 19:36:22 christos 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 36 #include <sys/types.h> 37 #include <errno.h> 38 #include <inttypes.h> 39 #include <libutil.h> 40 #include <stdio.h> 41 42 int 43 snprintb_m(char *buf, size_t buflen, const char *bitfmt, uint64_t val, 44 size_t l_max) 45 { 46 char *bp = buf, *s_bp = NULL; 47 const char *c_fmt, *s_fmt = NULL, *cur_fmt; 48 const char *sbase; 49 int bit, ch, t_len, s_len = 0, l_len, f_len, v_len, sep; 50 int restart = 0, matched = 1; 51 uint64_t field; 52 53 ch = *bitfmt++; 54 switch (ch != '\177' ? ch : *bitfmt++) { 55 case 8: 56 sbase = "%#jo"; 57 break; 58 case 10: 59 sbase = "%ju"; 60 break; 61 case 16: 62 sbase = "%#jx"; 63 break; 64 default: 65 goto internal; 66 } 67 68 /* Reserve space for trailing blank line if needed */ 69 if (l_max > 0) 70 buflen--; 71 72 t_len = snprintf(bp, buflen, sbase, (uintmax_t)val); 73 if (t_len < 0) 74 goto internal; 75 76 v_len = l_len = t_len; 77 78 if ((size_t)t_len < buflen) 79 bp += t_len; 80 else 81 bp += buflen - 1; 82 83 /* 84 * If the value we printed was 0 and we're using the old-style format, 85 * we're done. 86 */ 87 if ((val == 0) && (ch != '\177')) 88 goto terminate; 89 90 #define STORE(c) do { l_len++; \ 91 if ((size_t)(++t_len) < buflen) \ 92 *bp++ = (c); \ 93 } while ( /* CONSTCOND */ 0) 94 95 #define BACKUP do { if (s_bp != NULL) { \ 96 bp = s_bp; s_bp = NULL; \ 97 t_len -= l_len - s_len; \ 98 restart = 1; \ 99 bitfmt = s_fmt; \ 100 } \ 101 STORE('>'); STORE('\0'); \ 102 if ((size_t)t_len < buflen) \ 103 snprintf(bp, buflen - t_len, sbase, (uintmax_t)val);\ 104 t_len += v_len; l_len = v_len; bp += v_len; \ 105 } while ( /* CONSTCOND */ 0) 106 107 #define PUTSEP do { \ 108 if (l_max > 0 && (size_t)l_len >= l_max) { \ 109 BACKUP; \ 110 STORE('<'); \ 111 } else { \ 112 /* Remember separator location */ \ 113 if (l_max > 0 && sep != '<') { \ 114 s_len = l_len; \ 115 s_bp = bp; \ 116 s_fmt = cur_fmt; \ 117 } \ 118 STORE(sep); \ 119 restart = 0; \ 120 } \ 121 } while ( /* CONSTCOND */ 0) 122 123 #define PUTCHR(c) do { \ 124 if (l_max > 0 && (size_t)l_len >= (l_max - 1)) {\ 125 BACKUP; \ 126 if (restart == 0) \ 127 STORE(c); \ 128 else \ 129 sep = '<'; \ 130 } else { \ 131 STORE(c); \ 132 restart = 0; \ 133 } \ 134 } while ( /* CONSTCOND */ 0) 135 136 #define PUTS(s) while ((ch = *(s)++) != 0) { \ 137 PUTCHR(ch); \ 138 if (restart) \ 139 break; \ 140 } 141 #define FMTSTR(sb, f) \ 142 do { \ 143 f_len = snprintf(bp, buflen - t_len, sb, (uintmax_t)f); \ 144 if (f_len < 0) \ 145 goto internal; \ 146 t_len += f_len; \ 147 l_len += f_len; \ 148 if ((size_t)t_len < buflen) \ 149 bp += f_len; \ 150 } while (/*CONSTCOND*/0) 151 152 /* 153 * Chris Torek's new bitmask format is identified by a leading \177 154 */ 155 sep = '<'; 156 if (ch != '\177') { 157 /* old (standard) format. */ 158 for (;(bit = *bitfmt) != 0;) { 159 cur_fmt = bitfmt++; 160 if (val & (1U << (bit - 1))) { 161 PUTSEP; 162 if (restart) 163 continue; 164 sep = ','; 165 for (; (ch = *bitfmt) > ' '; ++bitfmt) { 166 PUTCHR(ch); 167 if (restart) 168 break; 169 } 170 } else 171 for (; *bitfmt > ' '; ++bitfmt) 172 continue; 173 } 174 } else { 175 /* new quad-capable format; also does fields. */ 176 field = val; 177 while (c_fmt = bitfmt, (ch = *bitfmt++) != '\0') { 178 bit = *bitfmt++; /* now 0-origin */ 179 switch (ch) { 180 case 'b': 181 if (((unsigned int)(val >> bit) & 1) == 0) 182 goto skip; 183 cur_fmt = c_fmt; 184 PUTSEP; 185 if (restart) 186 break; 187 PUTS(bitfmt); 188 if (restart == 0) 189 sep = ','; 190 break; 191 case 'f': 192 case 'F': 193 matched = 0; 194 cur_fmt = c_fmt; 195 f_len = *bitfmt++; /* field length */ 196 field = (val >> bit) & 197 (((uint64_t)1 << f_len) - 1); 198 PUTSEP; 199 if (restart == 0) 200 sep = ','; 201 if (ch == 'F') { /* just extract */ 202 /* duplicate PUTS() effect on bitfmt */ 203 while (*bitfmt++ != '\0') 204 continue; 205 break; 206 } 207 if (restart == 0) 208 PUTS(bitfmt); 209 if (restart == 0) 210 PUTCHR('='); 211 if (restart == 0) { 212 FMTSTR(sbase, field); 213 if (l_max > 0 && (size_t)l_len > l_max) 214 PUTCHR('#'); 215 } 216 break; 217 case '=': 218 case ':': 219 /* 220 * Here "bit" is actually a value instead, 221 * to be compared against the last field. 222 * This only works for values in [0..255], 223 * of course. 224 */ 225 if ((int)field != bit) 226 goto skip; 227 matched = 1; 228 if (ch == '=') 229 PUTCHR('='); 230 PUTS(bitfmt); 231 break; 232 case '*': 233 bitfmt--; 234 if (!matched) { 235 matched = 1; 236 FMTSTR(bitfmt, field); 237 } 238 /*FALLTHROUGH*/ 239 default: 240 skip: 241 while (*bitfmt++ != '\0') 242 continue; 243 break; 244 } 245 } 246 } 247 l_len++; 248 if (sep != '<' && (size_t)(++t_len) < buflen) 249 *bp++ = '>'; 250 terminate: 251 *bp++ = '\0'; 252 if (l_max != 0) { 253 t_len++; 254 *bp = '\0'; 255 } 256 return t_len; 257 internal: 258 errno = EINVAL; 259 return -1; 260 } 261 262 int 263 snprintb(char *buf, size_t buflen, const char *bitfmt, uint64_t val) 264 { 265 return snprintb_m(buf, buflen, bitfmt, val, 0); 266 } 267