1 /* $NetBSD: open_wmemstream.c,v 1.2 2024/01/23 15:32:54 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2013 Advanced Computing Technologies LLC 5 * Written by: John H. Baldwin <jhb (at) FreeBSD.org> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 #if 0 32 __FBSDID("$FreeBSD: head/lib/libc/stdio/open_wmemstream.c 247411 2013-02-27 19:50:46Z jhb $"); 33 #endif 34 __RCSID("$NetBSD: open_wmemstream.c,v 1.2 2024/01/23 15:32:54 christos Exp $"); 35 36 #include "namespace.h" 37 #include <assert.h> 38 #include <errno.h> 39 #include <limits.h> 40 #include <stdio.h> 41 #include <stdlib.h> 42 #include <string.h> 43 #include <wchar.h> 44 45 #define OFF_MAX LLONG_MAX 46 47 struct wmemstream { 48 wchar_t **bufp; 49 size_t *sizep; 50 size_t len; 51 size_t offset; 52 mbstate_t mbstate; 53 }; 54 55 static __inline size_t 56 off_t_to_size_t(off_t off) 57 { 58 if (off < 0 || off >= SSIZE_MAX) 59 return SSIZE_MAX - 1; 60 return (size_t)off; 61 } 62 63 static int 64 wmemstream_grow(struct wmemstream *ms, size_t newoff) 65 { 66 wchar_t *buf; 67 size_t newsize; 68 69 if (newoff >= (off_t)(SSIZE_MAX / sizeof(wchar_t))) 70 newsize = SSIZE_MAX / sizeof(wchar_t) - 1; 71 else 72 newsize = newoff; 73 if (newsize > ms->len) { 74 buf = realloc(*ms->bufp, (newsize + 1) * sizeof(wchar_t)); 75 if (buf != NULL) { 76 #ifdef DEBUG 77 fprintf(stderr, "WMS: %p growing from %zu to %zu\n", 78 ms, ms->len, newsize); 79 #endif 80 wmemset(buf + ms->len + 1, 0, newsize - ms->len); 81 *ms->bufp = buf; 82 ms->len = newsize; 83 return (1); 84 } 85 return (0); 86 } 87 return (1); 88 } 89 90 static void 91 wmemstream_update(struct wmemstream *ms) 92 { 93 94 *ms->sizep = ms->len < ms->offset ? ms->len : ms->offset; 95 } 96 97 /* 98 * Based on a starting multibyte state and an input buffer, determine 99 * how many wchar_t's would be output. This doesn't use mbsnrtowcs() 100 * so that it can handle embedded null characters. 101 */ 102 static ssize_t 103 wbuflen(const mbstate_t *state, const char *buf, size_t len) 104 { 105 mbstate_t lenstate; 106 size_t charlen, count; 107 108 count = 0; 109 lenstate = *state; 110 while (len > 0) { 111 charlen = mbrlen(buf, len, &lenstate); 112 if (charlen == (size_t)-1) 113 return (-1); 114 if (charlen == (size_t)-2) 115 break; 116 if (charlen == 0) 117 /* XXX: Not sure how else to handle this. */ 118 charlen = 1; 119 len -= charlen; 120 buf += charlen; 121 count++; 122 } 123 return (count); 124 } 125 126 static ssize_t 127 wmemstream_write(void *cookie, const void *buf, size_t len) 128 { 129 struct wmemstream *ms; 130 ssize_t consumed, wlen; 131 size_t charlen; 132 133 ms = cookie; 134 wlen = wbuflen(&ms->mbstate, buf, len); 135 if (wlen < 0) { 136 errno = EILSEQ; 137 return (-1); 138 } 139 if (!wmemstream_grow(ms, ms->offset + wlen)) 140 return (-1); 141 142 /* 143 * This copies characters one at a time rather than using 144 * mbsnrtowcs() so it can properly handle embedded null 145 * characters. 146 */ 147 consumed = 0; 148 while (len > 0 && ms->offset < ms->len) { 149 charlen = mbrtowc(*ms->bufp + ms->offset, buf, len, 150 &ms->mbstate); 151 if (charlen == (size_t)-1) { 152 if (consumed == 0) { 153 errno = EILSEQ; 154 return (-1); 155 } 156 /* Treat it as a successful short write. */ 157 break; 158 } 159 if (charlen == 0) 160 /* XXX: Not sure how else to handle this. */ 161 charlen = 1; 162 if (charlen == (size_t)-2) { 163 consumed += len; 164 len = 0; 165 } else { 166 consumed += charlen; 167 buf = (const char *)buf + charlen; 168 len -= charlen; 169 ms->offset++; 170 } 171 } 172 wmemstream_update(ms); 173 #ifdef DEBUG 174 fprintf(stderr, "WMS: write(%p, %zu) = %zd\n", ms, len, consumed); 175 #endif 176 return (consumed); 177 } 178 179 static off_t 180 wmemstream_seek(void *cookie, off_t pos, int whence) 181 { 182 struct wmemstream *ms; 183 size_t old; 184 185 ms = cookie; 186 old = ms->offset; 187 switch (whence) { 188 case SEEK_SET: 189 /* _fseeko() checks for negative offsets. */ 190 assert(pos >= 0); 191 ms->offset = off_t_to_size_t(pos); 192 break; 193 case SEEK_CUR: 194 /* This is only called by _ftello(). */ 195 assert(pos == 0); 196 break; 197 case SEEK_END: 198 if (pos < 0) { 199 if (pos + (ssize_t)ms->len < 0) { 200 #ifdef DEBUG 201 fprintf(stderr, 202 "WMS: bad SEEK_END: pos %jd, len %zd\n", 203 (intmax_t)pos, ms->len); 204 #endif 205 errno = EINVAL; 206 return (-1); 207 } 208 } else { 209 if (OFF_MAX - ms->len < (size_t)pos) { 210 #ifdef DEBUG 211 fprintf(stderr, 212 "WMS: bad SEEK_END: pos %jd, len %zd\n", 213 (intmax_t)pos, ms->len); 214 #endif 215 errno = EOVERFLOW; 216 return (-1); 217 } 218 } 219 ms->offset = off_t_to_size_t(ms->len + pos); 220 break; 221 } 222 /* Reset the multibyte state if a seek changes the position. */ 223 if (ms->offset != old) 224 memset(&ms->mbstate, 0, sizeof(ms->mbstate)); 225 wmemstream_update(ms); 226 #ifdef DEBUG 227 fprintf(stderr, "WMS: seek(%p, %jd, %d) %jd -> %jd\n", ms, 228 (intmax_t)pos, whence, (intmax_t)old, (intmax_t)ms->offset); 229 #endif 230 return (ms->offset); 231 } 232 233 static int 234 wmemstream_close(void *cookie) 235 { 236 237 free(cookie); 238 return (0); 239 } 240 241 FILE * 242 open_wmemstream(wchar_t **bufp, size_t *sizep) 243 { 244 struct wmemstream *ms; 245 int save_errno; 246 FILE *fp; 247 248 if (bufp == NULL || sizep == NULL) { 249 errno = EINVAL; 250 return (NULL); 251 } 252 *bufp = calloc(1, sizeof(wchar_t)); 253 if (*bufp == NULL) 254 return (NULL); 255 ms = malloc(sizeof(*ms)); 256 if (ms == NULL) { 257 save_errno = errno; 258 free(*bufp); 259 *bufp = NULL; 260 errno = save_errno; 261 return (NULL); 262 } 263 ms->bufp = bufp; 264 ms->sizep = sizep; 265 ms->len = 0; 266 ms->offset = 0; 267 memset(&ms->mbstate, 0, sizeof(mbstate_t)); 268 wmemstream_update(ms); 269 fp = funopen2(ms, NULL, wmemstream_write, wmemstream_seek, 270 NULL, wmemstream_close); 271 if (fp == NULL) { 272 save_errno = errno; 273 free(ms); 274 free(*bufp); 275 *bufp = NULL; 276 errno = save_errno; 277 return (NULL); 278 } 279 fwide(fp, 1); 280 return (fp); 281 } 282
Indexes created Sat Sep 20 22:09:52 GMT 2025