1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2013 Hudson River Trading LLC 5 * Written by: John H. Baldwin <jhb@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 __FBSDID("$FreeBSD$"); 32 33 #include "namespace.h" 34 #include <assert.h> 35 #include <errno.h> 36 #include <limits.h> 37 #ifdef DEBUG 38 #include <stdint.h> 39 #endif 40 #include <stdio.h> 41 #include <stdlib.h> 42 #include <string.h> 43 #include <wchar.h> 44 #include "un-namespace.h" 45 46 /* XXX: There is no FPOS_MAX. This assumes fpos_t is an off_t. */ 47 #define FPOS_MAX OFF_MAX 48 49 struct wmemstream { 50 wchar_t **bufp; 51 size_t *sizep; 52 ssize_t len; 53 fpos_t offset; 54 mbstate_t mbstate; 55 }; 56 57 static int 58 wmemstream_grow(struct wmemstream *ms, fpos_t newoff) 59 { 60 wchar_t *buf; 61 ssize_t newsize; 62 63 if (newoff < 0 || newoff >= SSIZE_MAX / sizeof(wchar_t)) 64 newsize = SSIZE_MAX / sizeof(wchar_t) - 1; 65 else 66 newsize = newoff; 67 if (newsize > ms->len) { 68 buf = reallocarray(*ms->bufp, newsize + 1, sizeof(wchar_t)); 69 if (buf != NULL) { 70 #ifdef DEBUG 71 fprintf(stderr, "WMS: %p growing from %zd to %zd\n", 72 ms, ms->len, newsize); 73 #endif 74 wmemset(buf + ms->len + 1, 0, newsize - ms->len); 75 *ms->bufp = buf; 76 ms->len = newsize; 77 return (1); 78 } 79 return (0); 80 } 81 return (1); 82 } 83 84 static void 85 wmemstream_update(struct wmemstream *ms) 86 { 87 88 assert(ms->len >= 0 && ms->offset >= 0); 89 *ms->sizep = ms->len < ms->offset ? ms->len : ms->offset; 90 } 91 92 /* 93 * Based on a starting multibyte state and an input buffer, determine 94 * how many wchar_t's would be output. This doesn't use mbsnrtowcs() 95 * so that it can handle embedded null characters. 96 */ 97 static size_t 98 wbuflen(const mbstate_t *state, const char *buf, int len) 99 { 100 mbstate_t lenstate; 101 size_t charlen, count; 102 103 count = 0; 104 lenstate = *state; 105 while (len > 0) { 106 charlen = mbrlen(buf, len, &lenstate); 107 if (charlen == (size_t)-1) 108 return (-1); 109 if (charlen == (size_t)-2) 110 break; 111 if (charlen == 0) 112 /* XXX: Not sure how else to handle this. */ 113 charlen = 1; 114 len -= charlen; 115 buf += charlen; 116 count++; 117 } 118 return (count); 119 } 120 121 static int 122 wmemstream_write(void *cookie, const char *buf, int len) 123 { 124 struct wmemstream *ms; 125 ssize_t consumed, wlen; 126 size_t charlen; 127 128 ms = cookie; 129 wlen = wbuflen(&ms->mbstate, buf, len); 130 if (wlen < 0) { 131 errno = EILSEQ; 132 return (-1); 133 } 134 if (!wmemstream_grow(ms, ms->offset + wlen)) 135 return (-1); 136 137 /* 138 * This copies characters one at a time rather than using 139 * mbsnrtowcs() so it can properly handle embedded null 140 * characters. 141 */ 142 consumed = 0; 143 while (len > 0 && ms->offset < ms->len) { 144 charlen = mbrtowc(*ms->bufp + ms->offset, buf, len, 145 &ms->mbstate); 146 if (charlen == (size_t)-1) { 147 if (consumed == 0) { 148 errno = EILSEQ; 149 return (-1); 150 } 151 /* Treat it as a successful short write. */ 152 break; 153 } 154 if (charlen == 0) 155 /* XXX: Not sure how else to handle this. */ 156 charlen = 1; 157 if (charlen == (size_t)-2) { 158 consumed += len; 159 len = 0; 160 } else { 161 consumed += charlen; 162 buf += charlen; 163 len -= charlen; 164 ms->offset++; 165 } 166 } 167 wmemstream_update(ms); 168 #ifdef DEBUG 169 fprintf(stderr, "WMS: write(%p, %d) = %zd\n", ms, len, consumed); 170 #endif 171 return (consumed); 172 } 173 174 static fpos_t 175 wmemstream_seek(void *cookie, fpos_t pos, int whence) 176 { 177 struct wmemstream *ms; 178 fpos_t old; 179 180 ms = cookie; 181 old = ms->offset; 182 switch (whence) { 183 case SEEK_SET: 184 /* _fseeko() checks for negative offsets. */ 185 assert(pos >= 0); 186 ms->offset = pos; 187 break; 188 case SEEK_CUR: 189 /* This is only called by _ftello(). */ 190 assert(pos == 0); 191 break; 192 case SEEK_END: 193 if (pos < 0) { 194 if (pos + ms->len < 0) { 195 #ifdef DEBUG 196 fprintf(stderr, 197 "WMS: bad SEEK_END: pos %jd, len %zd\n", 198 (intmax_t)pos, ms->len); 199 #endif 200 errno = EINVAL; 201 return (-1); 202 } 203 } else { 204 if (FPOS_MAX - ms->len < pos) { 205 #ifdef DEBUG 206 fprintf(stderr, 207 "WMS: bad SEEK_END: pos %jd, len %zd\n", 208 (intmax_t)pos, ms->len); 209 #endif 210 errno = EOVERFLOW; 211 return (-1); 212 } 213 } 214 ms->offset = ms->len + pos; 215 break; 216 } 217 /* Reset the multibyte state if a seek changes the position. */ 218 if (ms->offset != old) 219 memset(&ms->mbstate, 0, sizeof(ms->mbstate)); 220 wmemstream_update(ms); 221 #ifdef DEBUG 222 fprintf(stderr, "WMS: seek(%p, %jd, %d) %jd -> %jd\n", ms, 223 (intmax_t)pos, whence, (intmax_t)old, (intmax_t)ms->offset); 224 #endif 225 return (ms->offset); 226 } 227 228 static int 229 wmemstream_close(void *cookie) 230 { 231 232 free(cookie); 233 return (0); 234 } 235 236 FILE * 237 open_wmemstream(wchar_t **bufp, size_t *sizep) 238 { 239 struct wmemstream *ms; 240 int save_errno; 241 FILE *fp; 242 243 if (bufp == NULL || sizep == NULL) { 244 errno = EINVAL; 245 return (NULL); 246 } 247 *bufp = calloc(1, sizeof(wchar_t)); 248 if (*bufp == NULL) 249 return (NULL); 250 ms = malloc(sizeof(*ms)); 251 if (ms == NULL) { 252 save_errno = errno; 253 free(*bufp); 254 *bufp = NULL; 255 errno = save_errno; 256 return (NULL); 257 } 258 ms->bufp = bufp; 259 ms->sizep = sizep; 260 ms->len = 0; 261 ms->offset = 0; 262 memset(&ms->mbstate, 0, sizeof(mbstate_t)); 263 wmemstream_update(ms); 264 fp = funopen(ms, NULL, wmemstream_write, wmemstream_seek, 265 wmemstream_close); 266 if (fp == NULL) { 267 save_errno = errno; 268 free(ms); 269 free(*bufp); 270 *bufp = NULL; 271 errno = save_errno; 272 return (NULL); 273 } 274 fwide(fp, 1); 275 return (fp); 276 } 277