| 1 | /* |
| 2 | * Copyright (C) 2001 Edmund Grimley Evans <edmundo@rano.org> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License as published by |
| 6 | * the Free Software Foundation; either version 2 of the License, or |
| 7 | * (at your option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License along |
| 15 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 16 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 17 | */ |
| 18 | |
| 19 | #ifdef HAVE_CONFIG_H |
| 20 | # include <config.h> |
| 21 | #endif |
| 22 | |
| 23 | #if !defined _WIN32 && defined HAVE_ICONV |
| 24 | |
| 25 | #include <assert.h> |
| 26 | #include <errno.h> |
| 27 | #include <iconv.h> |
| 28 | #include <stdlib.h> |
| 29 | #include <string.h> |
| 30 | |
| 31 | #include "iconvert.h" |
| 32 | #include "share/alloc.h" |
| 33 | #include "share/safe_str.h" |
| 34 | |
| 35 | /* |
| 36 | * Convert data from one encoding to another. Return: |
| 37 | * |
| 38 | * -2 : memory allocation failed |
| 39 | * -1 : unknown encoding |
| 40 | * 0 : data was converted exactly |
| 41 | * 1 : data was converted inexactly |
| 42 | * 2 : data was invalid (but still converted) |
| 43 | * |
| 44 | * We convert in two steps, via UTF-8, as this is the only |
| 45 | * reliable way of distinguishing between invalid input |
| 46 | * and valid input which iconv refuses to transliterate. |
| 47 | * We convert from UTF-8 twice, because we have no way of |
| 48 | * knowing whether the conversion was exact if iconv returns |
| 49 | * E2BIG (due to a bug in the specification of iconv). |
| 50 | * An alternative approach is to assume that the output of |
| 51 | * iconv is never more than 4 times as long as the input, |
| 52 | * but I prefer to avoid that assumption if possible. |
| 53 | */ |
| 54 | |
| 55 | int iconvert(const char *fromcode, const char *tocode, |
| 56 | const char *from, size_t fromlen, |
| 57 | char **to, size_t *tolen) |
| 58 | { |
| 59 | int ret = 0; |
| 60 | iconv_t cd1, cd2; |
| 61 | char *ib; |
| 62 | char *ob; |
| 63 | char *utfbuf = 0, *outbuf, *newbuf; |
| 64 | size_t utflen, outlen, ibl, obl, k; |
| 65 | char tbuf[2048]; |
| 66 | |
| 67 | cd1 = iconv_open("UTF-8", fromcode); |
| 68 | if (cd1 == (iconv_t)(-1)) |
| 69 | return -1; |
| 70 | |
| 71 | cd2 = (iconv_t)(-1); |
| 72 | /* Don't use strcasecmp() as it's locale-dependent. */ |
| 73 | if (!strchr("Uu", tocode[0]) || |
| 74 | !strchr("Tt", tocode[1]) || |
| 75 | !strchr("Ff", tocode[2]) || |
| 76 | tocode[3] != '-' || |
| 77 | tocode[4] != '8' || |
| 78 | tocode[5] != '\0') { |
| 79 | char *tocode1; |
| 80 | size_t dest_len = strlen(tocode) + 11; |
| 81 | /* |
| 82 | * Try using this non-standard feature of glibc and libiconv. |
| 83 | * This is deliberately not a config option as people often |
| 84 | * change their iconv library without rebuilding applications. |
| 85 | */ |
| 86 | tocode1 = safe_malloc_(dest_len); |
| 87 | if (!tocode1) |
| 88 | goto fail; |
| 89 | |
| 90 | safe_strncpy(tocode1, tocode, dest_len); |
| 91 | safe_strncat(tocode1, "//TRANSLIT", dest_len); |
| 92 | cd2 = iconv_open(tocode1, "UTF-8"); |
| 93 | free(tocode1); |
| 94 | |
| 95 | if (cd2 == (iconv_t)(-1)) |
| 96 | cd2 = iconv_open(tocode, fromcode); |
| 97 | |
| 98 | if (cd2 == (iconv_t)(-1)) { |
| 99 | iconv_close(cd1); |
| 100 | return -1; |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | utflen = 1; /*fromlen * 2 + 1; XXX */ |
| 105 | utfbuf = malloc(utflen); |
| 106 | if (!utfbuf) |
| 107 | goto fail; |
| 108 | |
| 109 | /* Convert to UTF-8 */ |
| 110 | ib = (char *)from; |
| 111 | ibl = fromlen; |
| 112 | ob = utfbuf; |
| 113 | obl = utflen; |
| 114 | for (;;) { |
| 115 | k = iconv(cd1, &ib, &ibl, &ob, &obl); |
| 116 | assert((!k && !ibl) || |
| 117 | (k == (size_t)(-1) && errno == E2BIG && ibl && obl < 6) || |
| 118 | (k == (size_t)(-1) && |
| 119 | (errno == EILSEQ || errno == EINVAL) && ibl)); |
| 120 | if (!ibl) |
| 121 | break; |
| 122 | if (obl < 6) { |
| 123 | /* Enlarge the buffer */ |
| 124 | if(utflen*2 < utflen) /* overflow check */ |
| 125 | goto fail; |
| 126 | utflen *= 2; |
| 127 | newbuf = realloc(utfbuf, utflen); |
| 128 | if (!newbuf) |
| 129 | goto fail; |
| 130 | ob = (ob - utfbuf) + newbuf; |
| 131 | obl = utflen - (ob - newbuf); |
| 132 | utfbuf = newbuf; |
| 133 | } |
| 134 | else { |
| 135 | /* Invalid input */ |
| 136 | ib++, ibl--; |
| 137 | *ob++ = '#', obl--; |
| 138 | ret = 2; |
| 139 | iconv(cd1, 0, 0, 0, 0); |
| 140 | } |
| 141 | } |
| 142 | |
| 143 | if (cd2 == (iconv_t)(-1)) { |
| 144 | /* The target encoding was UTF-8 */ |
| 145 | if (tolen) |
| 146 | *tolen = ob - utfbuf; |
| 147 | if (!to) { |
| 148 | free(utfbuf); |
| 149 | iconv_close(cd1); |
| 150 | return ret; |
| 151 | } |
| 152 | newbuf = safe_realloc_add_2op_(utfbuf, (ob - utfbuf), /*+*/1); |
| 153 | if (!newbuf) |
| 154 | goto fail; |
| 155 | ob = (ob - utfbuf) + newbuf; |
| 156 | *ob = '\0'; |
| 157 | *to = newbuf; |
| 158 | iconv_close(cd1); |
| 159 | return ret; |
| 160 | } |
| 161 | |
| 162 | /* Truncate the buffer to be tidy */ |
| 163 | utflen = ob - utfbuf; |
| 164 | newbuf = realloc(utfbuf, utflen); |
| 165 | if (!newbuf) |
| 166 | goto fail; |
| 167 | utfbuf = newbuf; |
| 168 | |
| 169 | /* Convert from UTF-8 to discover how long the output is */ |
| 170 | outlen = 0; |
| 171 | ib = utfbuf; |
| 172 | ibl = utflen; |
| 173 | while (ibl) { |
| 174 | ob = tbuf; |
| 175 | obl = sizeof(tbuf); |
| 176 | k = iconv(cd2, &ib, &ibl, &ob, &obl); |
| 177 | assert((k != (size_t)(-1) && !ibl) || |
| 178 | (k == (size_t)(-1) && errno == E2BIG && ibl) || |
| 179 | (k == (size_t)(-1) && errno == EILSEQ && ibl)); |
| 180 | if (ibl && !(k == (size_t)(-1) && errno == E2BIG)) { |
| 181 | /* Replace one character */ |
| 182 | char *tb = "?"; |
| 183 | size_t tbl = 1; |
| 184 | |
| 185 | outlen += ob - tbuf; |
| 186 | ob = tbuf; |
| 187 | obl = sizeof(tbuf); |
| 188 | k = iconv(cd2, &tb, &tbl, &ob, &obl); |
| 189 | assert((!k && !tbl) || |
| 190 | (k == (size_t)(-1) && errno == EILSEQ && tbl)); |
| 191 | for (++ib, --ibl; ibl && (*ib & 0x80); ib++, ibl--) |
| 192 | ; |
| 193 | } |
| 194 | outlen += ob - tbuf; |
| 195 | } |
| 196 | ob = tbuf; |
| 197 | obl = sizeof(tbuf); |
| 198 | k = iconv(cd2, 0, 0, &ob, &obl); |
| 199 | assert(!k); |
| 200 | outlen += ob - tbuf; |
| 201 | |
| 202 | /* Convert from UTF-8 for real */ |
| 203 | outbuf = safe_malloc_add_2op_(outlen, /*+*/1); |
| 204 | if (!outbuf) |
| 205 | goto fail; |
| 206 | ib = utfbuf; |
| 207 | ibl = utflen; |
| 208 | ob = outbuf; |
| 209 | obl = outlen; |
| 210 | while (ibl) { |
| 211 | k = iconv(cd2, &ib, &ibl, &ob, &obl); |
| 212 | assert((k != (size_t)(-1) && !ibl) || |
| 213 | (k == (size_t)(-1) && errno == EILSEQ && ibl)); |
| 214 | if (k && !ret) |
| 215 | ret = 1; |
| 216 | if (ibl && !(k == (size_t)(-1) && errno == E2BIG)) { |
| 217 | /* Replace one character */ |
| 218 | char *tb = "?"; |
| 219 | size_t tbl = 1; |
| 220 | |
| 221 | k = iconv(cd2, &tb, &tbl, &ob, &obl); |
| 222 | assert((!k && !tbl) || |
| 223 | (k == (size_t)(-1) && errno == EILSEQ && tbl)); |
| 224 | for (++ib, --ibl; ibl && (*ib & 0x80); ib++, ibl--) |
| 225 | ; |
| 226 | } |
| 227 | } |
| 228 | k = iconv(cd2, 0, 0, &ob, &obl); |
| 229 | assert(!k); |
| 230 | assert(!obl); |
| 231 | *ob = '\0'; |
| 232 | |
| 233 | free(utfbuf); |
| 234 | iconv_close(cd1); |
| 235 | iconv_close(cd2); |
| 236 | if (tolen) |
| 237 | *tolen = outlen; |
| 238 | if (!to) { |
| 239 | free(outbuf); |
| 240 | return ret; |
| 241 | } |
| 242 | *to = outbuf; |
| 243 | return ret; |
| 244 | |
| 245 | fail: |
| 246 | if(0 != utfbuf) |
| 247 | free(utfbuf); |
| 248 | iconv_close(cd1); |
| 249 | if (cd2 != (iconv_t)(-1)) |
| 250 | iconv_close(cd2); |
| 251 | return -2; |
| 252 | } |
| 253 | |
| 254 | #endif /* HAVE_ICONV */ |