contrib/libarchive-2/libarchive/archive_string.c

   1 /*-
   2  * Copyright (c) 2003-2007 Tim Kientzle
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "archive_platform.h"
  27 __FBSDID("$FreeBSD: src/lib/libarchive/archive_string.c,v 1.16 2008/06/15 11:28:56 kientzle Exp $");
  28
  29 /*
  30  * Basic resizable string support, to simplify manipulating arbitrary-sized
  31  * strings while minimizing heap activity.
  32  */
  33
  34 #ifdef HAVE_STDLIB_H
  35 #include <stdlib.h>
  36 #endif
  37 #ifdef HAVE_STRING_H
  38 #include <string.h>
  39 #endif
  40 #ifdef HAVE_WCHAR_H
  41 #include <wchar.h>
  42 #endif
  43
  44 #include "archive_private.h"
  45 #include "archive_string.h"
  46
  47 struct archive_string *
  48 __archive_string_append(struct archive_string *as, const char *p, size_t s)
  49 {
  50         if (__archive_string_ensure(as, as->length + s + 1) == NULL)
  51                 __archive_errx(1, "Out of memory");
  52         memcpy(as->s + as->length, p, s);
  53         as->s[as->length + s] = 0;
  54         as->length += s;
  55         return (as);
  56 }
  57
  58 void
  59 __archive_string_copy(struct archive_string *dest, struct archive_string *src)
  60 {
  61         if (src->length == 0)
  62                 dest->length = 0;
  63         else {
  64                 if (__archive_string_ensure(dest, src->length + 1) == NULL)
  65                         __archive_errx(1, "Out of memory");
  66                 memcpy(dest->s, src->s, src->length);
  67                 dest->length = src->length;
  68                 dest->s[dest->length] = 0;
  69         }
  70 }
  71
  72 void
  73 __archive_string_free(struct archive_string *as)
  74 {
  75         as->length = 0;
  76         as->buffer_length = 0;
  77         if (as->s != NULL) {
  78                 free(as->s);
  79                 as->s = NULL;
  80         }
  81 }
  82
  83 /* Returns NULL on any allocation failure. */
  84 struct archive_string *
  85 __archive_string_ensure(struct archive_string *as, size_t s)
  86 {
  87         /* If buffer is already big enough, don't reallocate. */
  88         if (as->s && (s <= as->buffer_length))
  89                 return (as);
  90
  91         /*
  92          * Growing the buffer at least exponentially ensures that
  93          * append operations are always linear in the number of
  94          * characters appended.  Using a smaller growth rate for
  95          * larger buffers reduces memory waste somewhat at the cost of
  96          * a larger constant factor.
  97          */
  98         if (as->buffer_length < 32)
  99                 /* Start with a minimum 32-character buffer. */
 100                 as->buffer_length = 32;
 101         else if (as->buffer_length < 8192)
 102                 /* Buffers under 8k are doubled for speed. */
 103                 as->buffer_length *= 2;
 104         else {
 105                 /* Buffers 8k and over grow by at least 25% each time. */
 106                 size_t old_length = as->buffer_length;
 107                 as->buffer_length = (as->buffer_length * 5) / 4;
 108                 /* Be safe: If size wraps, release buffer and return NULL. */
 109                 if (as->buffer_length < old_length) {
 110                         free(as->s);
 111                         as->s = NULL;
 112                         return (NULL);
 113                 }
 114         }
 115         /*
 116          * The computation above is a lower limit to how much we'll
 117          * grow the buffer.  In any case, we have to grow it enough to
 118          * hold the request.
 119          */
 120         if (as->buffer_length < s)
 121                 as->buffer_length = s;
 122         /* Now we can reallocate the buffer. */
 123         as->s = (char *)realloc(as->s, as->buffer_length);
 124         if (as->s == NULL)
 125                 return (NULL);
 126         return (as);
 127 }
 128
 129 struct archive_string *
 130 __archive_strncat(struct archive_string *as, const char *p, size_t n)
 131 {
 132         size_t s;
 133         const char *pp;
 134
 135         /* Like strlen(p), except won't examine positions beyond p[n]. */
 136         s = 0;
 137         pp = p;
 138         while (*pp && s < n) {
 139                 pp++;
 140                 s++;
 141         }
 142         return (__archive_string_append(as, p, s));
 143 }
 144
 145 struct archive_string *
 146 __archive_strappend_char(struct archive_string *as, char c)
 147 {
 148         return (__archive_string_append(as, &c, 1));
 149 }
 150
 151 struct archive_string *
 152 __archive_strappend_int(struct archive_string *as, int d, int base)
 153 {
 154         static const char *digits = "0123456789abcdef";
 155
 156         if (d < 0) {
 157                 __archive_strappend_char(as, '-');
 158                 d = -d;
 159         }
 160         if (d >= base)
 161                 __archive_strappend_int(as, d/base, base);
 162         __archive_strappend_char(as, digits[d % base]);
 163         return (as);
 164 }
 165
 166 /*
 167  * Home-grown wctomb for UTF-8.
 168  */
 169 static int
 170 my_wctomb_utf8(char *p, wchar_t wc)
 171 {
 172         if (p == NULL)
 173                 /* UTF-8 doesn't use shift states. */
 174                 return (0);
 175         if (wc <= 0x7f) {
 176                 p[0] = (char)wc;
 177                 return (1);
 178         }
 179         if (wc <= 0x7ff) {
 180                 p[0] = 0xc0 | ((wc >> 6) & 0x1f);
 181                 p[1] = 0x80 | (wc & 0x3f);
 182                 return (2);
 183         }
 184         if (wc <= 0xffff) {
 185                 p[0] = 0xe0 | ((wc >> 12) & 0x0f);
 186                 p[1] = 0x80 | ((wc >> 6) & 0x3f);
 187                 p[2] = 0x80 | (wc & 0x3f);
 188                 return (3);
 189         }
 190         if (wc <= 0x1fffff) {
 191                 p[0] = 0xf0 | ((wc >> 18) & 0x07);
 192                 p[1] = 0x80 | ((wc >> 12) & 0x3f);
 193                 p[2] = 0x80 | ((wc >> 6) & 0x3f);
 194                 p[3] = 0x80 | (wc & 0x3f);
 195                 return (4);
 196         }
 197         /* Unicode has no codes larger than 0x1fffff. */
 198         /*
 199          * Awkward point:  UTF-8 <-> wchar_t conversions
 200          * can actually fail.
 201          */
 202         return (-1);
 203 }
 204
 205 static int
 206 my_wcstombs(struct archive_string *as, const wchar_t *w,
 207     int (*func)(char *, wchar_t))
 208 {
 209         int n;
 210         char *p;
 211         char buff[256];
 212
 213         /* Clear the shift state before starting. */
 214         (*func)(NULL, L'\0');
 215
 216         /*
 217          * Convert one wide char at a time into 'buff', whenever that
 218          * fills, append it to the string.
 219          */
 220         p = buff;
 221         while (*w != L'\0') {
 222                 /* Flush the buffer when we have <=16 bytes free. */
 223                 /* (No encoding has a single character >16 bytes.) */
 224                 if ((size_t)(p - buff) >= (size_t)(sizeof(buff) - 16)) {
 225                         *p = '\0';
 226                         archive_strcat(as, buff);
 227                         p = buff;
 228                 }
 229                 n = (*func)(p, *w++);
 230                 if (n == -1)
 231                         return (-1);
 232                 p += n;
 233         }
 234         *p = '\0';
 235         archive_strcat(as, buff);
 236         return (0);
 237 }
 238
 239 /*
 240  * Translates a wide character string into UTF-8 and appends
 241  * to the archive_string.  Note: returns NULL if conversion fails.
 242  */
 243 struct archive_string *
 244 __archive_strappend_w_utf8(struct archive_string *as, const wchar_t *w)
 245 {
 246         if (my_wcstombs(as, w, my_wctomb_utf8))
 247                 return (NULL);
 248         return (as);
 249 }
 250
 251 /*
 252  * Translates a wide character string into current locale character set
 253  * and appends to the archive_string.  Note: returns NULL if conversion
 254  * fails.
 255  */
 256 struct archive_string *
 257 __archive_strappend_w_mbs(struct archive_string *as, const wchar_t *w)
 258 {
 259 #if HAVE_WCTOMB
 260         if (my_wcstombs(as, w, wctomb))
 261                 return (NULL);
 262 #else
 263         /* TODO: Can we do better than this?  Are there platforms
 264          * that have locale support but don't have wctomb()? */
 265         if (my_wcstombs(as, w, my_wctomb_utf8))
 266                 return (NULL);
 267 #endif
 268         return (as);
 269 }
 270
 271
 272 /*
 273  * Home-grown mbtowc for UTF-8.  Some systems lack UTF-8
 274  * (or even lack mbtowc()) and we need UTF-8 support for pax
 275  * format.  So please don't replace this with a call to the
 276  * standard mbtowc() function!
 277  */
 278 static int
 279 my_mbtowc_utf8(wchar_t *pwc, const char *s, size_t n)
 280 {
 281         int ch;
 282
 283         /* Standard behavior:  a NULL value for 's' just resets shift state. */
 284         if (s == NULL)
 285                 return (0);
 286         /* If length argument is zero, don't look at the first character. */
 287         if (n <= 0)
 288                 return (-1);
 289
 290         /*
 291          * Decode 1-4 bytes depending on the value of the first byte.
 292          */
 293         ch = (unsigned char)*s;
 294         if (ch == 0) {
 295                 return (0); /* Standard:  return 0 for end-of-string. */
 296         }
 297         if ((ch & 0x80) == 0) {
 298                 *pwc = ch & 0x7f;
 299                 return (1);
 300         }
 301         if ((ch & 0xe0) == 0xc0) {
 302                 if (n < 2)
 303                         return (-1);
 304                 if ((s[1] & 0xc0) != 0x80) return (-1);
 305                 *pwc = ((ch & 0x1f) << 6) | (s[1] & 0x3f);
 306                 return (2);
 307         }
 308         if ((ch & 0xf0) == 0xe0) {
 309                 if (n < 3)
 310                         return (-1);
 311                 if ((s[1] & 0xc0) != 0x80) return (-1);
 312                 if ((s[2] & 0xc0) != 0x80) return (-1);
 313                 *pwc = ((ch & 0x0f) << 12)
 314                     | ((s[1] & 0x3f) << 6)
 315                     | (s[2] & 0x3f);
 316                 return (3);
 317         }
 318         if ((ch & 0xf8) == 0xf0) {
 319                 if (n < 4)
 320                         return (-1);
 321                 if ((s[1] & 0xc0) != 0x80) return (-1);
 322                 if ((s[2] & 0xc0) != 0x80) return (-1);
 323                 if ((s[3] & 0xc0) != 0x80) return (-1);
 324                 *pwc = ((ch & 0x07) << 18)
 325                     | ((s[1] & 0x3f) << 12)
 326                     | ((s[2] & 0x3f) << 6)
 327                     | (s[3] & 0x3f);
 328                 return (4);
 329         }
 330         /* Invalid first byte. */
 331         return (-1);
 332 }
 333
 334 /*
 335  * Return a wide-character string by converting this archive_string
 336  * from UTF-8.
 337  */
 338 wchar_t *
 339 __archive_string_utf8_w(struct archive_string *as)
 340 {
 341         wchar_t *ws, *dest;
 342         const char *src;
 343         int n;
 344         int err;
 345
 346         ws = (wchar_t *)malloc((as->length + 1) * sizeof(wchar_t));
 347         if (ws == NULL)
 348                 __archive_errx(1, "Out of memory");
 349         err = 0;
 350         dest = ws;
 351         src = as->s;
 352         while (*src != '\0') {
 353                 n = my_mbtowc_utf8(dest, src, 8);
 354                 if (n == 0)
 355                         break;
 356                 if (n < 0) {
 357                         free(ws);
 358                         return (NULL);
 359                 }
 360                 dest++;
 361                 src += n;
 362         }
 363         *dest++ = L'\0';
 364         return (ws);
 365 }