1 | /* |
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2 | * COPYRIGHT (c) 1989-2010. |
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3 | * On-Line Applications Research Corporation (OAR). |
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4 | * |
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5 | * The license and distribution terms for this file may be |
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6 | * found in the file LICENSE in this distribution or at |
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7 | * http://www.rtems.com/license/LICENSE. |
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8 | * |
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9 | * $Id$ |
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10 | */ |
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11 | |
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12 | #if HAVE_CONFIG_H |
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13 | #include "config.h" |
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14 | #endif |
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15 | |
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16 | /* |
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17 | * This file implements the "mount" procedure for tar-based IMFS |
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18 | * extensions. The TAR is not actually mounted under the IMFS. |
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19 | * Directories from the TAR file are created as usual in the IMFS. |
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20 | * File entries are created as IMFS_LINEAR_FILE nodes with their nods |
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21 | * pointing to addresses in the TAR image. |
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22 | */ |
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23 | |
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24 | #include <sys/types.h> |
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25 | #include <sys/stat.h> |
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26 | #include <fcntl.h> |
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27 | |
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28 | #include <string.h> |
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29 | |
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30 | #include <rtems.h> |
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31 | #include <rtems/libio_.h> |
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32 | #include <rtems/imfs.h> |
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33 | #include <rtems/untar.h> |
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34 | #include <rtems/tar.h> |
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35 | |
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36 | /* |
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37 | * TAR file format: |
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38 | * |
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39 | * Offset Length Contents |
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40 | * 0 100 bytes File name ('\0' terminated, 99 maxmum length) |
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41 | * 100 8 bytes File mode (in octal ascii) |
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42 | * 108 8 bytes User ID (in octal ascii) |
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43 | * 116 8 bytes Group ID (in octal ascii) |
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44 | * 124 12 bytes File size (s) (in octal ascii) |
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45 | * 136 12 bytes Modify time (in octal ascii) |
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46 | * 148 8 bytes Header checksum (in octal ascii) |
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47 | * 156 1 bytes Link flag |
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48 | * 157 100 bytes Linkname ('\0' terminated, 99 maxmum length) |
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49 | * 257 8 bytes Magic ("ustar \0") |
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50 | * 265 32 bytes User name ('\0' terminated, 31 maxmum length) |
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51 | * 297 32 bytes Group name ('\0' terminated, 31 maxmum length) |
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52 | * 329 8 bytes Major device ID (in octal ascii) |
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53 | * 337 8 bytes Minor device ID (in octal ascii) |
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54 | * 345 167 bytes Padding |
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55 | * 512 (s+p)bytes File contents (s+p) := (((s) + 511) & ~511), |
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56 | * round up to 512 bytes |
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57 | * |
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58 | * Checksum: |
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59 | * int i, sum; |
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60 | * char* header = tar_header_pointer; |
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61 | * sum = 0; |
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62 | * for(i = 0; i < 512; i++) |
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63 | * sum += 0xFF & header[i]; |
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64 | */ |
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65 | |
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66 | #define MAX_NAME_FIELD_SIZE 99 |
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67 | |
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68 | #define MIN(a,b) ((a)>(b)?(b):(a)) |
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69 | |
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70 | /* |
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71 | * rtems_tarfs_load |
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72 | * |
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73 | * Here we create the mountpoint directory and load the tarfs at |
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74 | * that node. Once the IMFS has been mounted, we work through the |
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75 | * tar image and perform as follows: |
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76 | * - For directories, simply call mkdir(). The IMFS creates nodes as |
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77 | * needed. |
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78 | * - For files, we make our own calls to IMFS eval_for_make and |
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79 | * create_node. |
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80 | */ |
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81 | int rtems_tarfs_load( |
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82 | char *mountpoint, |
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83 | uint8_t *tar_image, |
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84 | size_t tar_size |
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85 | ) |
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86 | { |
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87 | rtems_filesystem_location_info_t root_loc; |
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88 | rtems_filesystem_location_info_t loc; |
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89 | const char *hdr_ptr; |
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90 | char filename[100]; |
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91 | char full_filename[256]; |
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92 | int hdr_chksum; |
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93 | unsigned char linkflag; |
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94 | unsigned long file_size; |
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95 | unsigned long file_mode; |
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96 | int offset; |
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97 | unsigned long nblocks; |
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98 | IMFS_jnode_t *node; |
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99 | int status; |
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100 | |
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101 | status = rtems_filesystem_evaluate_path( |
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102 | mountpoint, |
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103 | strlen(mountpoint), |
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104 | 0, |
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105 | &root_loc, |
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106 | 0 |
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107 | ); |
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108 | if (status != 0) |
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109 | return -1; |
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110 | |
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111 | if (root_loc.ops != &IMFS_ops) |
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112 | return -1; |
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113 | |
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114 | /* |
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115 | * Create an IMFS node structure pointing to tar image memory. |
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116 | */ |
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117 | offset = 0; |
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118 | while (1) { |
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119 | if (offset + 512 > tar_size) |
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120 | break; |
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121 | |
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122 | /* |
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123 | * Read a header. |
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124 | */ |
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125 | hdr_ptr = (char *) &tar_image[offset]; |
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126 | offset += 512; |
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127 | if (strncmp(&hdr_ptr[257], "ustar ", 7)) |
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128 | break; |
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129 | |
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130 | strncpy(filename, hdr_ptr, MAX_NAME_FIELD_SIZE); |
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131 | filename[MAX_NAME_FIELD_SIZE] = '\0'; |
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132 | |
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133 | linkflag = hdr_ptr[156]; |
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134 | file_mode = _rtems_octal2ulong(&hdr_ptr[100], 8); |
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135 | file_size = _rtems_octal2ulong(&hdr_ptr[124], 12); |
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136 | hdr_chksum = _rtems_octal2ulong(&hdr_ptr[148], 8); |
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137 | |
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138 | if (_rtems_tar_header_checksum(hdr_ptr) != hdr_chksum) |
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139 | break; |
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140 | |
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141 | /* |
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142 | * Generate an IMFS node depending on the file type. |
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143 | * - For directories, just create directories as usual. IMFS |
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144 | * will take care of the rest. |
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145 | * - For files, create a file node with special tarfs properties. |
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146 | */ |
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147 | if (linkflag == DIRTYPE) { |
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148 | strcpy(full_filename, mountpoint); |
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149 | if (full_filename[strlen(full_filename)-1] != '/') |
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150 | strcat(full_filename, "/"); |
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151 | strcat(full_filename, filename); |
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152 | mkdir(full_filename, S_IRWXU | S_IRWXG | S_IRWXO); |
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153 | } |
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154 | /* |
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155 | * Create a LINEAR_FILE node |
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156 | * |
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157 | * NOTE: Coverity Id 20 reports this as a leak. |
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158 | * While technically not a leak, it indicated that |
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159 | * IMFS_create_node was ONLY passed a NULL when we created the |
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160 | * root node. We added a new IMFS_create_root_node() so this |
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161 | * path no longer existed. The result was simpler code which |
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162 | * should not have this path. |
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163 | */ |
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164 | else if (linkflag == REGTYPE) { |
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165 | const char *name; |
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166 | |
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167 | loc = root_loc; |
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168 | if (IMFS_evaluate_for_make(filename, &loc, &name) == 0) { |
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169 | node = IMFS_create_node( |
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170 | &loc, |
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171 | IMFS_LINEAR_FILE, (char *)name, |
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172 | (file_mode & (S_IRWXU | S_IRWXG | S_IRWXO)) | S_IFREG, |
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173 | NULL |
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174 | ); |
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175 | node->info.linearfile.size = file_size; |
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176 | node->info.linearfile.direct = &tar_image[offset]; |
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177 | } |
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178 | |
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179 | nblocks = (((file_size) + 511) & ~511) / 512; |
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180 | offset += 512 * nblocks; |
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181 | } |
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182 | } |
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183 | return status; |
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184 | } |
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185 | |
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