1 | /* gzlib.c -- zlib functions common to reading and writing gzip files |
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2 | * Copyright (C) 2004, 2010 Mark Adler |
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3 | * For conditions of distribution and use, see copyright notice in zlib.h |
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4 | */ |
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5 | |
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6 | #include "gzguts.h" |
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7 | |
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8 | #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0 |
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9 | # define LSEEK lseek64 |
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10 | #else |
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11 | # define LSEEK lseek |
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12 | #endif |
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13 | |
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14 | /* Local functions */ |
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15 | local void gz_reset OF((gz_statep)); |
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16 | local gzFile gz_open OF((const char *, int, const char *)); |
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17 | |
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18 | #if defined UNDER_CE |
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19 | |
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20 | /* Map the Windows error number in ERROR to a locale-dependent error message |
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21 | string and return a pointer to it. Typically, the values for ERROR come |
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22 | from GetLastError. |
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23 | |
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24 | The string pointed to shall not be modified by the application, but may be |
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25 | overwritten by a subsequent call to gz_strwinerror |
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26 | |
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27 | The gz_strwinerror function does not change the current setting of |
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28 | GetLastError. */ |
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29 | char ZLIB_INTERNAL *gz_strwinerror (error) |
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30 | DWORD error; |
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31 | { |
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32 | static char buf[1024]; |
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33 | |
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34 | wchar_t *msgbuf; |
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35 | DWORD lasterr = GetLastError(); |
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36 | DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
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37 | | FORMAT_MESSAGE_ALLOCATE_BUFFER, |
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38 | NULL, |
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39 | error, |
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40 | 0, /* Default language */ |
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41 | (LPVOID)&msgbuf, |
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42 | 0, |
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43 | NULL); |
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44 | if (chars != 0) { |
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45 | /* If there is an \r\n appended, zap it. */ |
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46 | if (chars >= 2 |
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47 | && msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') { |
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48 | chars -= 2; |
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49 | msgbuf[chars] = 0; |
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50 | } |
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51 | |
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52 | if (chars > sizeof (buf) - 1) { |
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53 | chars = sizeof (buf) - 1; |
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54 | msgbuf[chars] = 0; |
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55 | } |
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56 | |
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57 | wcstombs(buf, msgbuf, chars + 1); |
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58 | LocalFree(msgbuf); |
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59 | } |
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60 | else { |
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61 | sprintf(buf, "unknown win32 error (%ld)", error); |
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62 | } |
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63 | |
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64 | SetLastError(lasterr); |
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65 | return buf; |
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66 | } |
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67 | |
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68 | #endif /* UNDER_CE */ |
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69 | |
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70 | /* Reset gzip file state */ |
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71 | local void gz_reset(state) |
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72 | gz_statep state; |
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73 | { |
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74 | if (state->mode == GZ_READ) { /* for reading ... */ |
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75 | state->have = 0; /* no output data available */ |
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76 | state->eof = 0; /* not at end of file */ |
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77 | state->how = LOOK; /* look for gzip header */ |
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78 | state->direct = 1; /* default for empty file */ |
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79 | } |
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80 | state->seek = 0; /* no seek request pending */ |
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81 | gz_error(state, Z_OK, NULL); /* clear error */ |
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82 | state->pos = 0; /* no uncompressed data yet */ |
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83 | state->strm.avail_in = 0; /* no input data yet */ |
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84 | } |
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85 | |
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86 | /* Open a gzip file either by name or file descriptor. */ |
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87 | local gzFile gz_open(path, fd, mode) |
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88 | const char *path; |
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89 | int fd; |
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90 | const char *mode; |
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91 | { |
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92 | gz_statep state; |
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93 | |
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94 | /* allocate gzFile structure to return */ |
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95 | state = malloc(sizeof(gz_state)); |
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96 | if (state == NULL) |
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97 | return NULL; |
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98 | state->size = 0; /* no buffers allocated yet */ |
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99 | state->want = GZBUFSIZE; /* requested buffer size */ |
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100 | state->msg = NULL; /* no error message yet */ |
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101 | |
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102 | /* interpret mode */ |
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103 | state->mode = GZ_NONE; |
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104 | state->level = Z_DEFAULT_COMPRESSION; |
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105 | state->strategy = Z_DEFAULT_STRATEGY; |
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106 | while (*mode) { |
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107 | if (*mode >= '0' && *mode <= '9') |
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108 | state->level = *mode - '0'; |
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109 | else |
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110 | switch (*mode) { |
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111 | case 'r': |
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112 | state->mode = GZ_READ; |
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113 | break; |
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114 | #ifndef NO_GZCOMPRESS |
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115 | case 'w': |
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116 | state->mode = GZ_WRITE; |
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117 | break; |
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118 | case 'a': |
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119 | state->mode = GZ_APPEND; |
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120 | break; |
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121 | #endif |
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122 | case '+': /* can't read and write at the same time */ |
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123 | free(state); |
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124 | return NULL; |
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125 | case 'b': /* ignore -- will request binary anyway */ |
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126 | break; |
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127 | case 'f': |
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128 | state->strategy = Z_FILTERED; |
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129 | break; |
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130 | case 'h': |
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131 | state->strategy = Z_HUFFMAN_ONLY; |
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132 | break; |
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133 | case 'R': |
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134 | state->strategy = Z_RLE; |
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135 | break; |
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136 | case 'F': |
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137 | state->strategy = Z_FIXED; |
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138 | default: /* could consider as an error, but just ignore */ |
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139 | ; |
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140 | } |
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141 | mode++; |
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142 | } |
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143 | |
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144 | /* must provide an "r", "w", or "a" */ |
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145 | if (state->mode == GZ_NONE) { |
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146 | free(state); |
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147 | return NULL; |
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148 | } |
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149 | |
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150 | /* save the path name for error messages */ |
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151 | state->path = malloc(strlen(path) + 1); |
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152 | if (state->path == NULL) { |
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153 | free(state); |
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154 | return NULL; |
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155 | } |
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156 | strcpy(state->path, path); |
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157 | |
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158 | /* open the file with the appropriate mode (or just use fd) */ |
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159 | state->fd = fd != -1 ? fd : |
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160 | open(path, |
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161 | #ifdef O_LARGEFILE |
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162 | O_LARGEFILE | |
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163 | #endif |
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164 | #ifdef O_BINARY |
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165 | O_BINARY | |
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166 | #endif |
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167 | (state->mode == GZ_READ ? |
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168 | O_RDONLY : |
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169 | (O_WRONLY | O_CREAT | ( |
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170 | state->mode == GZ_WRITE ? |
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171 | O_TRUNC : |
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172 | O_APPEND))), |
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173 | 0666); |
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174 | if (state->fd == -1) { |
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175 | free(state->path); |
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176 | free(state); |
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177 | return NULL; |
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178 | } |
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179 | if (state->mode == GZ_APPEND) |
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180 | state->mode = GZ_WRITE; /* simplify later checks */ |
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181 | |
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182 | /* save the current position for rewinding (only if reading) */ |
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183 | if (state->mode == GZ_READ) { |
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184 | state->start = LSEEK(state->fd, 0, SEEK_CUR); |
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185 | if (state->start == -1) state->start = 0; |
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186 | } |
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187 | |
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188 | /* initialize stream */ |
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189 | gz_reset(state); |
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190 | |
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191 | /* return stream */ |
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192 | return (gzFile)state; |
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193 | } |
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194 | |
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195 | /* -- see zlib.h -- */ |
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196 | gzFile ZEXPORT gzopen(path, mode) |
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197 | const char *path; |
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198 | const char *mode; |
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199 | { |
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200 | return gz_open(path, -1, mode); |
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201 | } |
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202 | |
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203 | /* -- see zlib.h -- */ |
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204 | gzFile ZEXPORT gzopen64(path, mode) |
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205 | const char *path; |
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206 | const char *mode; |
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207 | { |
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208 | return gz_open(path, -1, mode); |
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209 | } |
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210 | |
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211 | /* -- see zlib.h -- */ |
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212 | gzFile ZEXPORT gzdopen(fd, mode) |
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213 | int fd; |
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214 | const char *mode; |
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215 | { |
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216 | char *path; /* identifier for error messages */ |
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217 | gzFile gz; |
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218 | |
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219 | if (fd == -1 || (path = malloc(7 + 3 * sizeof(int))) == NULL) |
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220 | return NULL; |
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221 | sprintf(path, "<fd:%d>", fd); /* for debugging */ |
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222 | gz = gz_open(path, fd, mode); |
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223 | free(path); |
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224 | return gz; |
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225 | } |
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226 | |
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227 | /* -- see zlib.h -- */ |
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228 | int ZEXPORT gzbuffer(file, size) |
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229 | gzFile file; |
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230 | unsigned size; |
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231 | { |
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232 | gz_statep state; |
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233 | |
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234 | /* get internal structure and check integrity */ |
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235 | if (file == NULL) |
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236 | return -1; |
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237 | state = (gz_statep)file; |
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238 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
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239 | return -1; |
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240 | |
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241 | /* make sure we haven't already allocated memory */ |
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242 | if (state->size != 0) |
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243 | return -1; |
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244 | |
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245 | /* check and set requested size */ |
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246 | if (size == 0) |
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247 | return -1; |
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248 | state->want = size; |
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249 | return 0; |
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250 | } |
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251 | |
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252 | /* -- see zlib.h -- */ |
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253 | int ZEXPORT gzrewind(file) |
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254 | gzFile file; |
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255 | { |
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256 | gz_statep state; |
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257 | |
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258 | /* get internal structure */ |
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259 | if (file == NULL) |
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260 | return -1; |
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261 | state = (gz_statep)file; |
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262 | |
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263 | /* check that we're reading and that there's no error */ |
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264 | if (state->mode != GZ_READ || state->err != Z_OK) |
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265 | return -1; |
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266 | |
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267 | /* back up and start over */ |
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268 | if (LSEEK(state->fd, state->start, SEEK_SET) == -1) |
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269 | return -1; |
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270 | gz_reset(state); |
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271 | return 0; |
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272 | } |
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273 | |
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274 | /* -- see zlib.h -- */ |
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275 | z_off64_t ZEXPORT gzseek64(file, offset, whence) |
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276 | gzFile file; |
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277 | z_off64_t offset; |
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278 | int whence; |
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279 | { |
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280 | unsigned n; |
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281 | z_off64_t ret; |
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282 | gz_statep state; |
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283 | |
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284 | /* get internal structure and check integrity */ |
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285 | if (file == NULL) |
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286 | return -1; |
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287 | state = (gz_statep)file; |
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288 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
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289 | return -1; |
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290 | |
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291 | /* check that there's no error */ |
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292 | if (state->err != Z_OK) |
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293 | return -1; |
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294 | |
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295 | /* can only seek from start or relative to current position */ |
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296 | if (whence != SEEK_SET && whence != SEEK_CUR) |
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297 | return -1; |
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298 | |
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299 | /* normalize offset to a SEEK_CUR specification */ |
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300 | if (whence == SEEK_SET) |
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301 | offset -= state->pos; |
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302 | else if (state->seek) |
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303 | offset += state->skip; |
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304 | state->seek = 0; |
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305 | |
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306 | /* if within raw area while reading, just go there */ |
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307 | if (state->mode == GZ_READ && state->how == COPY && |
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308 | state->pos + offset >= state->raw) { |
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309 | ret = LSEEK(state->fd, offset - state->have, SEEK_CUR); |
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310 | if (ret == -1) |
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311 | return -1; |
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312 | state->have = 0; |
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313 | state->eof = 0; |
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314 | state->seek = 0; |
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315 | gz_error(state, Z_OK, NULL); |
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316 | state->strm.avail_in = 0; |
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317 | state->pos += offset; |
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318 | return state->pos; |
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319 | } |
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320 | |
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321 | /* calculate skip amount, rewinding if needed for back seek when reading */ |
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322 | if (offset < 0) { |
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323 | if (state->mode != GZ_READ) /* writing -- can't go backwards */ |
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324 | return -1; |
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325 | offset += state->pos; |
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326 | if (offset < 0) /* before start of file! */ |
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327 | return -1; |
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328 | if (gzrewind(file) == -1) /* rewind, then skip to offset */ |
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329 | return -1; |
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330 | } |
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331 | |
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332 | /* if reading, skip what's in output buffer (one less gzgetc() check) */ |
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333 | if (state->mode == GZ_READ) { |
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334 | n = GT_OFF(state->have) || (z_off64_t)state->have > offset ? |
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335 | (unsigned)offset : state->have; |
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336 | state->have -= n; |
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337 | state->next += n; |
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338 | state->pos += n; |
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339 | offset -= n; |
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340 | } |
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341 | |
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342 | /* request skip (if not zero) */ |
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343 | if (offset) { |
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344 | state->seek = 1; |
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345 | state->skip = offset; |
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346 | } |
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347 | return state->pos + offset; |
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348 | } |
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349 | |
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350 | /* -- see zlib.h -- */ |
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351 | z_off_t ZEXPORT gzseek(file, offset, whence) |
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352 | gzFile file; |
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353 | z_off_t offset; |
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354 | int whence; |
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355 | { |
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356 | z_off64_t ret; |
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357 | |
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358 | ret = gzseek64(file, (z_off64_t)offset, whence); |
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359 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; |
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360 | } |
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361 | |
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362 | /* -- see zlib.h -- */ |
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363 | z_off64_t ZEXPORT gztell64(file) |
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364 | gzFile file; |
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365 | { |
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366 | gz_statep state; |
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367 | |
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368 | /* get internal structure and check integrity */ |
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369 | if (file == NULL) |
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370 | return -1; |
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371 | state = (gz_statep)file; |
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372 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
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373 | return -1; |
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374 | |
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375 | /* return position */ |
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376 | return state->pos + (state->seek ? state->skip : 0); |
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377 | } |
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378 | |
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379 | /* -- see zlib.h -- */ |
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380 | z_off_t ZEXPORT gztell(file) |
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381 | gzFile file; |
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382 | { |
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383 | z_off64_t ret; |
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384 | |
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385 | ret = gztell64(file); |
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386 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; |
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387 | } |
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388 | |
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389 | /* -- see zlib.h -- */ |
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390 | z_off64_t ZEXPORT gzoffset64(file) |
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391 | gzFile file; |
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392 | { |
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393 | z_off64_t offset; |
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394 | gz_statep state; |
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395 | |
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396 | /* get internal structure and check integrity */ |
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397 | if (file == NULL) |
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398 | return -1; |
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399 | state = (gz_statep)file; |
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400 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
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401 | return -1; |
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402 | |
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403 | /* compute and return effective offset in file */ |
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404 | offset = LSEEK(state->fd, 0, SEEK_CUR); |
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405 | if (offset == -1) |
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406 | return -1; |
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407 | if (state->mode == GZ_READ) /* reading */ |
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408 | offset -= state->strm.avail_in; /* don't count buffered input */ |
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409 | return offset; |
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410 | } |
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411 | |
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412 | /* -- see zlib.h -- */ |
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413 | z_off_t ZEXPORT gzoffset(file) |
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414 | gzFile file; |
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415 | { |
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416 | z_off64_t ret; |
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417 | |
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418 | ret = gzoffset64(file); |
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419 | return ret == (z_off_t)ret ? (z_off_t)ret : -1; |
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420 | } |
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421 | |
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422 | /* -- see zlib.h -- */ |
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423 | int ZEXPORT gzeof(file) |
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424 | gzFile file; |
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425 | { |
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426 | gz_statep state; |
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427 | |
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428 | /* get internal structure and check integrity */ |
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429 | if (file == NULL) |
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430 | return 0; |
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431 | state = (gz_statep)file; |
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432 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
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433 | return 0; |
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434 | |
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435 | /* return end-of-file state */ |
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436 | return state->mode == GZ_READ ? |
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437 | (state->eof && state->strm.avail_in == 0 && state->have == 0) : 0; |
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438 | } |
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439 | |
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440 | /* -- see zlib.h -- */ |
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441 | const char * ZEXPORT gzerror(file, errnum) |
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442 | gzFile file; |
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443 | int *errnum; |
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444 | { |
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445 | gz_statep state; |
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446 | |
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447 | /* get internal structure and check integrity */ |
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448 | if (file == NULL) |
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449 | return NULL; |
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450 | state = (gz_statep)file; |
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451 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
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452 | return NULL; |
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453 | |
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454 | /* return error information */ |
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455 | if (errnum != NULL) |
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456 | *errnum = state->err; |
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457 | return state->msg == NULL ? "" : state->msg; |
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458 | } |
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459 | |
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460 | /* -- see zlib.h -- */ |
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461 | void ZEXPORT gzclearerr(file) |
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462 | gzFile file; |
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463 | { |
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464 | gz_statep state; |
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465 | |
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466 | /* get internal structure and check integrity */ |
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467 | if (file == NULL) |
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468 | return; |
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469 | state = (gz_statep)file; |
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470 | if (state->mode != GZ_READ && state->mode != GZ_WRITE) |
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471 | return; |
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472 | |
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473 | /* clear error and end-of-file */ |
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474 | if (state->mode == GZ_READ) |
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475 | state->eof = 0; |
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476 | gz_error(state, Z_OK, NULL); |
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477 | } |
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478 | |
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479 | /* Create an error message in allocated memory and set state->err and |
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480 | state->msg accordingly. Free any previous error message already there. Do |
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481 | not try to free or allocate space if the error is Z_MEM_ERROR (out of |
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482 | memory). Simply save the error message as a static string. If there is an |
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483 | allocation failure constructing the error message, then convert the error to |
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484 | out of memory. */ |
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485 | void ZLIB_INTERNAL gz_error(state, err, msg) |
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486 | gz_statep state; |
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487 | int err; |
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488 | const char *msg; |
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489 | { |
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490 | /* free previously allocated message and clear */ |
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491 | if (state->msg != NULL) { |
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492 | if (state->err != Z_MEM_ERROR) |
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493 | free(state->msg); |
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494 | state->msg = NULL; |
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495 | } |
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496 | |
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497 | /* set error code, and if no message, then done */ |
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498 | state->err = err; |
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499 | if (msg == NULL) |
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500 | return; |
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501 | |
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502 | /* for an out of memory error, save as static string */ |
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503 | if (err == Z_MEM_ERROR) { |
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504 | state->msg = (char *)msg; |
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505 | return; |
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506 | } |
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507 | |
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508 | /* construct error message with path */ |
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509 | if ((state->msg = malloc(strlen(state->path) + strlen(msg) + 3)) == NULL) { |
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510 | state->err = Z_MEM_ERROR; |
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511 | state->msg = (char *)"out of memory"; |
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512 | return; |
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513 | } |
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514 | strcpy(state->msg, state->path); |
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515 | strcat(state->msg, ": "); |
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516 | strcat(state->msg, msg); |
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517 | return; |
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518 | } |
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519 | |
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520 | #ifndef INT_MAX |
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521 | /* portably return maximum value for an int (when limits.h presumed not |
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522 | available) -- we need to do this to cover cases where 2's complement not |
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523 | used, since C standard permits 1's complement and sign-bit representations, |
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524 | otherwise we could just use ((unsigned)-1) >> 1 */ |
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525 | unsigned ZLIB_INTERNAL gz_intmax() |
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526 | { |
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527 | unsigned p, q; |
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528 | |
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529 | p = 1; |
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530 | do { |
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531 | q = p; |
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532 | p <<= 1; |
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533 | p++; |
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534 | } while (p > q); |
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535 | return q >> 1; |
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536 | } |
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537 | #endif |
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