archive_read_open_file.c 5.0 KB

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  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. #include "archive_platform.h"
  26. __FBSDID("$FreeBSD: head/lib/libarchive/archive_read_open_file.c 201093 2009-12-28 02:28:44Z kientzle $");
  27. #ifdef HAVE_SYS_STAT_H
  28. #include <sys/stat.h>
  29. #endif
  30. #ifdef HAVE_ERRNO_H
  31. #include <errno.h>
  32. #endif
  33. #ifdef HAVE_FCNTL_H
  34. #include <fcntl.h>
  35. #endif
  36. #ifdef HAVE_IO_H
  37. #include <io.h>
  38. #endif
  39. #ifdef HAVE_STDLIB_H
  40. #include <stdlib.h>
  41. #endif
  42. #ifdef HAVE_STRING_H
  43. #include <string.h>
  44. #endif
  45. #ifdef HAVE_UNISTD_H
  46. #include <unistd.h>
  47. #endif
  48. #include "archive.h"
  49. struct read_FILE_data {
  50. FILE *f;
  51. size_t block_size;
  52. void *buffer;
  53. char can_skip;
  54. };
  55. static int file_close(struct archive *, void *);
  56. static ssize_t file_read(struct archive *, void *, const void **buff);
  57. static int64_t file_skip(struct archive *, void *, int64_t request);
  58. int
  59. archive_read_open_FILE(struct archive *a, FILE *f)
  60. {
  61. struct stat st;
  62. struct read_FILE_data *mine;
  63. size_t block_size = 128 * 1024;
  64. void *b;
  65. archive_clear_error(a);
  66. mine = (struct read_FILE_data *)malloc(sizeof(*mine));
  67. b = malloc(block_size);
  68. if (mine == NULL || b == NULL) {
  69. archive_set_error(a, ENOMEM, "No memory");
  70. free(mine);
  71. free(b);
  72. return (ARCHIVE_FATAL);
  73. }
  74. mine->block_size = block_size;
  75. mine->buffer = b;
  76. mine->f = f;
  77. /*
  78. * If we can't fstat() the file, it may just be that it's not
  79. * a file. (On some platforms, FILE * objects can wrap I/O
  80. * streams that don't support fileno()). As a result, fileno()
  81. * should be used cautiously.)
  82. */
  83. if (fstat(fileno(mine->f), &st) == 0 && S_ISREG(st.st_mode)) {
  84. archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino);
  85. /* Enable the seek optimization only for regular files. */
  86. mine->can_skip = 1;
  87. } else
  88. mine->can_skip = 0;
  89. #if defined(__CYGWIN__) || defined(_WIN32)
  90. setmode(fileno(mine->f), O_BINARY);
  91. #endif
  92. archive_read_set_read_callback(a, file_read);
  93. archive_read_set_skip_callback(a, file_skip);
  94. archive_read_set_close_callback(a, file_close);
  95. archive_read_set_callback_data(a, mine);
  96. return (archive_read_open1(a));
  97. }
  98. static ssize_t
  99. file_read(struct archive *a, void *client_data, const void **buff)
  100. {
  101. struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
  102. size_t bytes_read;
  103. *buff = mine->buffer;
  104. bytes_read = fread(mine->buffer, 1, mine->block_size, mine->f);
  105. if (bytes_read < mine->block_size && ferror(mine->f)) {
  106. archive_set_error(a, errno, "Error reading file");
  107. }
  108. return (bytes_read);
  109. }
  110. static int64_t
  111. file_skip(struct archive *a, void *client_data, int64_t request)
  112. {
  113. struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
  114. #if HAVE_FSEEKO
  115. off_t skip = (off_t)request;
  116. #elif HAVE__FSEEKI64
  117. int64_t skip = request;
  118. #else
  119. long skip = (long)request;
  120. #endif
  121. int skip_bits = sizeof(skip) * 8 - 1;
  122. (void)a; /* UNUSED */
  123. /*
  124. * If we can't skip, return 0 as the amount we did step and
  125. * the caller will work around by reading and discarding.
  126. */
  127. if (!mine->can_skip)
  128. return (0);
  129. if (request == 0)
  130. return (0);
  131. /* If request is too big for a long or an off_t, reduce it. */
  132. if (sizeof(request) > sizeof(skip)) {
  133. int64_t max_skip =
  134. (((int64_t)1 << (skip_bits - 1)) - 1) * 2 + 1;
  135. if (request > max_skip)
  136. skip = max_skip;
  137. }
  138. #ifdef __ANDROID__
  139. /* fileno() isn't safe on all platforms ... see above. */
  140. if (lseek(fileno(mine->f), skip, SEEK_CUR) < 0)
  141. #elif HAVE_FSEEKO
  142. if (fseeko(mine->f, skip, SEEK_CUR) != 0)
  143. #elif HAVE__FSEEKI64
  144. if (_fseeki64(mine->f, skip, SEEK_CUR) != 0)
  145. #else
  146. if (fseek(mine->f, skip, SEEK_CUR) != 0)
  147. #endif
  148. {
  149. mine->can_skip = 0;
  150. return (0);
  151. }
  152. return (request);
  153. }
  154. static int
  155. file_close(struct archive *a, void *client_data)
  156. {
  157. struct read_FILE_data *mine = (struct read_FILE_data *)client_data;
  158. (void)a; /* UNUSED */
  159. if (mine->buffer != NULL)
  160. free(mine->buffer);
  161. free(mine);
  162. return (ARCHIVE_OK);
  163. }