1 | /** |
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2 | * @file |
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3 | * |
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4 | * @brief Open a File |
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5 | * @ingroup libcsupport |
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6 | */ |
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7 | |
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8 | /* |
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9 | * COPYRIGHT (c) 1989-2010. |
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10 | * On-Line Applications Research Corporation (OAR). |
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11 | * |
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12 | * Modifications to support reference counting in the file system are |
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13 | * Copyright (c) 2012 embedded brains GmbH. |
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14 | * |
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15 | * The license and distribution terms for this file may be |
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16 | * found in the file LICENSE in this distribution or at |
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17 | * http://www.rtems.org/license/LICENSE. |
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18 | */ |
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19 | |
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20 | #if HAVE_CONFIG_H |
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21 | #include "config.h" |
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22 | #endif |
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23 | |
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24 | #include <sys/stat.h> |
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25 | #include <fcntl.h> |
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26 | #include <stdarg.h> |
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27 | #include <unistd.h> |
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28 | |
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29 | #include <rtems/libio_.h> |
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30 | |
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31 | static void create_regular_file( |
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32 | rtems_filesystem_eval_path_context_t *ctx, |
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33 | mode_t mode |
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34 | ) |
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35 | { |
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36 | int rv = 0; |
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37 | const rtems_filesystem_location_info_t *currentloc = |
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38 | rtems_filesystem_eval_path_get_currentloc( ctx ); |
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39 | const char *token = rtems_filesystem_eval_path_get_token( ctx ); |
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40 | size_t tokenlen = rtems_filesystem_eval_path_get_tokenlen( ctx ); |
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41 | |
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42 | rv = rtems_filesystem_mknod( |
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43 | currentloc, |
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44 | token, |
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45 | tokenlen, |
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46 | S_IFREG | mode, |
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47 | 0 |
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48 | ); |
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49 | |
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50 | if ( rv == 0 ) { |
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51 | /* The mode only applies to future accesses of the newly created file */ |
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52 | rtems_filesystem_eval_path_set_flags( ctx, 0 ); |
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53 | |
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54 | rtems_filesystem_eval_path_set_path( ctx, token, tokenlen ); |
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55 | rtems_filesystem_eval_path_continue( ctx ); |
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56 | } else { |
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57 | rtems_filesystem_eval_path_error( ctx, 0 ); |
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58 | } |
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59 | } |
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60 | |
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61 | static int do_open( |
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62 | rtems_libio_t *iop, |
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63 | const char *path, |
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64 | int oflag, |
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65 | mode_t mode |
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66 | ) |
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67 | { |
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68 | int rv = 0; |
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69 | int fd = iop - rtems_libio_iops; |
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70 | int rwflag = oflag + 1; |
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71 | bool read_access = (rwflag & _FREAD) == _FREAD; |
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72 | bool write_access = (rwflag & _FWRITE) == _FWRITE; |
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73 | bool make = (oflag & O_CREAT) == O_CREAT; |
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74 | bool exclusive = (oflag & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL); |
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75 | bool truncate = (oflag & O_TRUNC) == O_TRUNC; |
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76 | int eval_flags = RTEMS_FS_FOLLOW_LINK |
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77 | | (read_access ? RTEMS_FS_PERMS_READ : 0) |
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78 | | (write_access ? RTEMS_FS_PERMS_WRITE : 0) |
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79 | | (make ? RTEMS_FS_MAKE : 0) |
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80 | | (exclusive ? RTEMS_FS_EXCLUSIVE : 0); |
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81 | rtems_filesystem_eval_path_context_t ctx; |
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82 | |
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83 | rtems_filesystem_eval_path_start( &ctx, path, eval_flags ); |
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84 | |
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85 | if ( rtems_filesystem_eval_path_has_token( &ctx ) ) { |
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86 | create_regular_file( &ctx, mode ); |
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87 | } |
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88 | |
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89 | if ( write_access ) { |
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90 | const rtems_filesystem_location_info_t *currentloc = |
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91 | rtems_filesystem_eval_path_get_currentloc( &ctx ); |
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92 | mode_t type = rtems_filesystem_location_type( currentloc ); |
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93 | |
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94 | if ( S_ISDIR( type ) ) { |
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95 | rtems_filesystem_eval_path_error( &ctx, EISDIR ); |
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96 | } |
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97 | } |
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98 | |
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99 | iop->flags |= rtems_libio_fcntl_flags( oflag ); |
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100 | rtems_filesystem_eval_path_extract_currentloc( &ctx, &iop->pathinfo ); |
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101 | rtems_filesystem_eval_path_cleanup( &ctx ); |
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102 | |
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103 | rv = (*iop->pathinfo.handlers->open_h)( iop, path, oflag, mode ); |
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104 | |
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105 | if ( rv == 0 ) { |
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106 | if ( truncate ) { |
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107 | rv = ftruncate( fd, 0 ); |
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108 | if ( rv != 0 ) { |
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109 | (*iop->pathinfo.handlers->close_h)( iop ); |
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110 | } |
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111 | } |
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112 | |
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113 | if ( rv == 0 ) { |
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114 | rv = fd; |
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115 | } else { |
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116 | rv = -1; |
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117 | } |
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118 | } |
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119 | |
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120 | if ( rv < 0 ) { |
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121 | rtems_libio_free( iop ); |
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122 | } |
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123 | |
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124 | return rv; |
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125 | } |
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126 | |
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127 | /** |
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128 | * POSIX 1003.1 5.3.1 - Open a File |
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129 | */ |
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130 | int open( const char *path, int oflag, ... ) |
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131 | { |
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132 | int rv = 0; |
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133 | va_list ap; |
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134 | mode_t mode = 0; |
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135 | rtems_libio_t *iop = NULL; |
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136 | |
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137 | va_start( ap, oflag ); |
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138 | |
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139 | mode = va_arg( ap, mode_t ); |
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140 | |
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141 | iop = rtems_libio_allocate(); |
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142 | if ( iop != NULL ) { |
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143 | rv = do_open( iop, path, oflag, mode ); |
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144 | } else { |
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145 | errno = ENFILE; |
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146 | rv = -1; |
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147 | } |
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148 | |
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149 | va_end( ap ); |
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150 | |
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151 | return rv; |
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152 | } |
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153 | |
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154 | |
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155 | |
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156 | #if defined(RTEMS_NEWLIB) && !defined(HAVE__OPEN_R) |
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157 | |
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158 | #include <reent.h> |
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159 | |
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160 | /** |
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161 | * This is the Newlib dependent reentrant version of open(). |
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162 | */ |
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163 | int _open_r( |
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164 | struct _reent *ptr __attribute__((unused)), |
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165 | const char *buf, |
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166 | int oflag, |
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167 | int mode |
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168 | ) |
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169 | { |
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170 | return open( buf, oflag, mode ); |
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171 | } |
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172 | #endif |
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