1 | /* |
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2 | * This file contains the support infrastructure used to manage the |
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3 | * table of integer style file descriptors used by the low level |
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4 | * POSIX system calls like open(), read, fstat(), etc. |
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5 | * |
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6 | * COPYRIGHT (c) 1989-1998. |
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7 | * On-Line Applications Research Corporation (OAR). |
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8 | * Copyright assigned to U.S. Government, 1994. |
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9 | * |
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10 | * The license and distribution terms for this file may be |
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11 | * found in the file LICENSE in this distribution or at |
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12 | * http://www.OARcorp.com/rtems/license.html. |
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13 | * |
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14 | * $Id$ |
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15 | */ |
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16 | |
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17 | #include "libio_.h" /* libio_.h pulls in rtems */ |
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18 | #include <rtems.h> |
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19 | #include <rtems/assoc.h> /* assoc.h not included by rtems.h */ |
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20 | |
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21 | #include <stdio.h> /* O_RDONLY, et.al. */ |
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22 | #include <fcntl.h> /* O_RDONLY, et.al. */ |
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23 | #include <assert.h> |
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24 | #include <errno.h> |
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25 | |
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26 | #if ! defined(O_NDELAY) |
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27 | # if defined(solaris2) |
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28 | # define O_NDELAY O_NONBLOCK |
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29 | # elif defined(RTEMS_NEWLIB) |
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30 | # define O_NDELAY _FNBIO |
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31 | # endif |
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32 | #endif |
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33 | |
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34 | |
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35 | #include <errno.h> |
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36 | #include <string.h> /* strcmp */ |
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37 | #include <unistd.h> |
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38 | #include <stdlib.h> /* calloc() */ |
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39 | |
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40 | #include "libio.h" /* libio.h not pulled in by rtems */ |
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41 | |
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42 | /* |
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43 | * File descriptor Table Information |
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44 | */ |
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45 | |
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46 | extern unsigned32 rtems_libio_number_iops; |
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47 | rtems_id rtems_libio_semaphore; |
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48 | rtems_libio_t *rtems_libio_iops; |
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49 | rtems_libio_t *rtems_libio_last_iop; |
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50 | rtems_libio_t *rtems_libio_iop_freelist; |
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51 | |
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52 | /* |
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53 | * External I/O Handlers Table |
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54 | * |
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55 | * Space for all possible handlers is preallocated |
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56 | * to speed up dispatch to external handlers. |
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57 | */ |
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58 | |
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59 | rtems_libio_handler_t rtems_libio_handlers[15]; |
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60 | |
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61 | /* |
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62 | * Default mode for all files. |
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63 | */ |
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64 | |
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65 | mode_t rtems_filesystem_umask; |
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66 | |
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67 | /* |
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68 | * rtems_register_libio_handler |
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69 | * |
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70 | * This function registers an external IO handler set. This lets |
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71 | * other subsystems have their own versions of many of the system |
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72 | * calls. For example, the networking code registers handlers which |
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73 | * map the system calls for read() and write() to socket calls. |
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74 | * |
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75 | */ |
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76 | |
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77 | void rtems_register_libio_handler( |
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78 | int handler_flag, |
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79 | const rtems_libio_handler_t *handler |
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80 | ) |
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81 | { |
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82 | int handler_index = (handler_flag >> LIBIO_FLAGS_HANDLER_SHIFT) - 1; |
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83 | |
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84 | if ((handler_index < 0) || (handler_index >= 15)) |
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85 | rtems_fatal_error_occurred( RTEMS_INVALID_NUMBER ); |
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86 | |
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87 | rtems_libio_handlers[handler_index] = *handler; |
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88 | } |
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89 | |
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90 | /* |
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91 | * rtems_libio_init |
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92 | * |
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93 | * Called by BSP startup code to initialize the libio subsystem. |
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94 | */ |
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95 | |
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96 | void rtems_libio_init( void ) |
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97 | { |
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98 | rtems_status_code rc; |
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99 | int i; |
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100 | rtems_libio_t *iop; |
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101 | |
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102 | if (rtems_libio_number_iops > 0) |
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103 | { |
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104 | rtems_libio_iops = (rtems_libio_t *) calloc(rtems_libio_number_iops, |
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105 | sizeof(rtems_libio_t)); |
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106 | if (rtems_libio_iops == NULL) |
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107 | rtems_fatal_error_occurred(RTEMS_NO_MEMORY); |
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108 | |
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109 | iop = rtems_libio_iop_freelist = rtems_libio_iops; |
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110 | for (i = 0 ; i < (rtems_libio_number_iops - 1) ; i++, iop++) |
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111 | iop->data1 = iop + 1; |
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112 | iop->data1 = NULL; |
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113 | } |
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114 | |
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115 | /* |
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116 | * Create the binary semaphore used to provide mutual exclusion |
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117 | * on the IOP Table. |
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118 | */ |
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119 | |
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120 | rc = rtems_semaphore_create( |
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121 | RTEMS_LIBIO_SEM, |
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122 | 1, |
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123 | RTEMS_BINARY_SEMAPHORE | RTEMS_INHERIT_PRIORITY | RTEMS_PRIORITY, |
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124 | RTEMS_NO_PRIORITY, |
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125 | &rtems_libio_semaphore |
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126 | ); |
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127 | if ( rc != RTEMS_SUCCESSFUL ) |
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128 | rtems_fatal_error_occurred( rc ); |
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129 | |
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130 | /* |
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131 | * Initialize the base file system infrastructure. |
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132 | */ |
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133 | |
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134 | rtems_filesystem_initialize(); |
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135 | } |
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136 | |
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137 | /* |
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138 | * rtems_libio_fcntl_flags |
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139 | * |
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140 | * Convert UNIX fnctl(2) flags to ones that RTEMS drivers understand |
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141 | */ |
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142 | |
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143 | rtems_assoc_t access_modes_assoc[] = { |
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144 | { "READ", LIBIO_FLAGS_READ, O_RDONLY }, |
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145 | { "WRITE", LIBIO_FLAGS_WRITE, O_WRONLY }, |
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146 | { "READ/WRITE", LIBIO_FLAGS_READ_WRITE, O_RDWR }, |
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147 | { 0, 0, 0 }, |
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148 | }; |
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149 | |
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150 | rtems_assoc_t status_flags_assoc[] = { |
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151 | { "NO DELAY", LIBIO_FLAGS_NO_DELAY, O_NDELAY }, |
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152 | { "APPEND", LIBIO_FLAGS_APPEND, O_APPEND }, |
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153 | { "CREATE", LIBIO_FLAGS_CREATE, O_CREAT }, |
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154 | { 0, 0, 0 }, |
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155 | }; |
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156 | |
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157 | unsigned32 rtems_libio_fcntl_flags( |
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158 | unsigned32 fcntl_flags |
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159 | ) |
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160 | { |
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161 | unsigned32 flags = 0; |
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162 | unsigned32 access_modes; |
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163 | |
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164 | /* |
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165 | * Access mode is a small integer |
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166 | */ |
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167 | |
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168 | access_modes = fcntl_flags & O_ACCMODE; |
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169 | fcntl_flags &= ~O_ACCMODE; |
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170 | flags = rtems_assoc_local_by_remote( access_modes_assoc, access_modes ); |
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171 | |
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172 | /* |
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173 | * Everything else is single bits |
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174 | */ |
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175 | |
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176 | flags |= |
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177 | rtems_assoc_local_by_remote_bitfield(status_flags_assoc, fcntl_flags); |
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178 | return flags; |
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179 | } |
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180 | |
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181 | /* |
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182 | * rtems_libio_allocate |
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183 | * |
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184 | * This routine searches the IOP Table for an unused entry. If it |
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185 | * finds one, it returns it. Otherwise, it returns NULL. |
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186 | */ |
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187 | |
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188 | rtems_libio_t *rtems_libio_allocate( void ) |
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189 | { |
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190 | rtems_libio_t *iop; |
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191 | rtems_status_code rc; |
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192 | |
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193 | rtems_semaphore_obtain( rtems_libio_semaphore, RTEMS_WAIT, RTEMS_NO_TIMEOUT ); |
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194 | |
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195 | if (rtems_libio_iop_freelist) { |
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196 | iop = rtems_libio_iop_freelist; |
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197 | rc = rtems_semaphore_create( |
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198 | RTEMS_LIBIO_IOP_SEM(iop - rtems_libio_iops), |
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199 | 1, |
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200 | RTEMS_BINARY_SEMAPHORE | RTEMS_INHERIT_PRIORITY | RTEMS_PRIORITY, |
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201 | RTEMS_NO_PRIORITY, |
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202 | &iop->sem |
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203 | ); |
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204 | if (rc != RTEMS_SUCCESSFUL) |
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205 | goto failed; |
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206 | rtems_libio_iop_freelist = iop->data1; |
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207 | iop->data1 = 0; |
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208 | iop->flags = LIBIO_FLAGS_OPEN; |
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209 | goto done; |
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210 | } |
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211 | |
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212 | failed: |
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213 | iop = 0; |
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214 | |
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215 | done: |
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216 | rtems_semaphore_release( rtems_libio_semaphore ); |
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217 | return iop; |
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218 | } |
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219 | |
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220 | /* |
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221 | * rtems_libio_free |
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222 | * |
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223 | * This routine frees the resources associated with an IOP (file descriptor) |
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224 | * and clears the slot in the IOP Table. |
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225 | */ |
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226 | |
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227 | void rtems_libio_free( |
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228 | rtems_libio_t *iop |
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229 | ) |
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230 | { |
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231 | rtems_semaphore_obtain( rtems_libio_semaphore, RTEMS_WAIT, RTEMS_NO_TIMEOUT ); |
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232 | |
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233 | if (iop->sem) |
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234 | rtems_semaphore_delete(iop->sem); |
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235 | |
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236 | iop->data1 = rtems_libio_iop_freelist; |
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237 | rtems_libio_iop_freelist = iop; |
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238 | |
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239 | rtems_semaphore_release(rtems_libio_semaphore); |
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240 | } |
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241 | |
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242 | /* |
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243 | * rtems_libio_is_open_files_in_fs |
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244 | * |
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245 | * This routine scans the entire file descriptor table to determine if the |
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246 | * are any active file descriptors that refer to the at least one node in the |
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247 | * file system that we are trying to dismount. |
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248 | * |
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249 | * If there is at least one node in the file system referenced by the mount |
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250 | * table entry a 1 is returned, otherwise a 0 is returned. |
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251 | */ |
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252 | |
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253 | int rtems_libio_is_open_files_in_fs( |
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254 | rtems_filesystem_mount_table_entry_t * fs_mt_entry |
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255 | ) |
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256 | { |
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257 | rtems_libio_t *iop; |
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258 | int result = 0; |
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259 | |
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260 | rtems_semaphore_obtain( rtems_libio_semaphore, RTEMS_WAIT, RTEMS_NO_TIMEOUT ); |
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261 | |
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262 | /* |
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263 | * Look for any active file descriptor entry. |
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264 | */ |
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265 | |
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266 | for ( iop=rtems_libio_iops ; iop <= rtems_libio_last_iop ; iop++ ) { |
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267 | |
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268 | if ((iop->flags & LIBIO_FLAGS_OPEN) != 0) { |
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269 | |
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270 | /* |
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271 | * Check if this node is under the file system that we |
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272 | * are trying to dismount. |
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273 | */ |
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274 | |
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275 | if ( iop->pathinfo.mt_entry == fs_mt_entry ) { |
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276 | result = 1; |
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277 | break; |
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278 | } |
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279 | } |
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280 | } |
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281 | |
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282 | rtems_semaphore_release( rtems_libio_semaphore ); |
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283 | |
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284 | return result; |
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285 | } |
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286 | |
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287 | /* |
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288 | * rtems_libio_is_file_open |
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289 | * |
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290 | * This routine scans the entire file descriptor table to determine if the |
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291 | * given file refers to an active file descriptor. |
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292 | * |
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293 | * If the given file is open a 1 is returned, otherwise a 0 is returned. |
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294 | */ |
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295 | |
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296 | int rtems_libio_is_file_open( |
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297 | void *node_access |
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298 | ) |
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299 | { |
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300 | rtems_libio_t *iop; |
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301 | int result=0; |
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302 | |
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303 | rtems_semaphore_obtain( rtems_libio_semaphore, RTEMS_WAIT, RTEMS_NO_TIMEOUT ); |
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304 | |
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305 | /* |
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306 | * Look for any active file descriptor entry. |
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307 | */ |
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308 | |
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309 | for ( iop=rtems_libio_iops ; iop <= rtems_libio_last_iop ; iop++ ) { |
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310 | |
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311 | if ((iop->flags & LIBIO_FLAGS_OPEN) != 0) { |
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312 | |
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313 | /* |
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314 | * Check if this node is under the file system that we |
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315 | * are trying to dismount. |
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316 | */ |
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317 | |
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318 | if ( iop->pathinfo.node_access == node_access ) { |
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319 | result = 1; |
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320 | break; |
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321 | } |
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322 | } |
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323 | } |
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324 | |
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325 | rtems_semaphore_release( rtems_libio_semaphore ); |
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326 | |
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327 | return result; |
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328 | } |
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329 | |
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330 | |
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