summaryrefslogtreecommitdiff
path: root/FatPkg/EnhancedFatDxe/Open.c
blob: b6369cf0b3af10d19cada1b4d8a8658b64a51832 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
/*++

Copyright (c) 2005 - 2007, Intel Corporation
All rights reserved. This program and the accompanying materials are licensed and made available
under the terms and conditions of the BSD License which accompanies this
distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php

THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.


Module Name:

  open.c

Abstract:

  Routines dealing with file open

Revision History

--*/

#include "Fat.h"

EFI_STATUS
FatAllocateIFile (
  IN FAT_OFILE    *OFile,
  OUT FAT_IFILE   **PtrIFile
  )
/*++

Routine Description:

  Create an Open instance for the existing OFile.
  The IFile of the newly opened file is passed out.

Arguments:

  OFile                 - The file that serves as a starting reference point.
  PtrIFile              - The newly generated IFile instance.

Returns:

  EFI_OUT_OF_RESOURCES  - Can not allocate the memory for the IFile
  EFI_SUCCESS           - Create the new IFile for the OFile successfully

--*/
{
  FAT_IFILE *IFile;

  ASSERT_VOLUME_LOCKED (OFile->Volume);

  //
  // Allocate a new open instance
  //
  IFile = AllocateZeroPool (sizeof (FAT_IFILE));
  if (IFile == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  IFile->Signature = FAT_IFILE_SIGNATURE;

  CopyMem (&(IFile->Handle), &FatFileInterface, sizeof (EFI_FILE));

  IFile->OFile = OFile;
  InsertTailList (&OFile->Opens, &IFile->Link);

  *PtrIFile = IFile;
  return EFI_SUCCESS;
}

EFI_STATUS
FatOFileOpen (
  IN  FAT_OFILE            *OFile,
  OUT FAT_IFILE            **NewIFile,
  IN  CHAR16               *FileName,
  IN  UINT64               OpenMode,
  IN  UINT8                Attributes
  )
/*++

Routine Description:

  Open a file for a file name relative to an existing OFile.
  The IFile of the newly opened file is passed out.

Arguments:

  OFile                 - The file that serves as a starting reference point.
  NewIFile              - The newly generated IFile instance.
  FileName              - The file name relative to the OFile.
  OpenMode              - Open mode.
  Attributes            - Attributes to set if the file is created.

Returns:

  EFI_SUCCESS           - Open the file successfully.
  EFI_INVALID_PARAMETER - The open mode is conflict with the attributes
                          or the file name is not valid.
  EFI_NOT_FOUND         - Conficts between dir intention and attribute.
  EFI_WRITE_PROTECTED   - Can't open for write if the volume is read only.
  EFI_ACCESS_DENIED     - If the file's attribute is read only, and the
                          open is for read-write fail it.
  EFI_OUT_OF_RESOURCES  - Can not allocate the memory.

--*/
{
  FAT_VOLUME  *Volume;
  EFI_STATUS  Status;
  CHAR16      NewFileName[EFI_PATH_STRING_LENGTH];
  FAT_DIRENT  *DirEnt;
  UINT8       FileAttributes;
  BOOLEAN     WriteMode;

  Volume = OFile->Volume;
  ASSERT_VOLUME_LOCKED (Volume);
  WriteMode = (BOOLEAN) (OpenMode & EFI_FILE_MODE_WRITE);
  if (Volume->ReadOnly && WriteMode) {
    return EFI_WRITE_PROTECTED;
  }
  //
  // Verify the source file handle isn't in an error state
  //
  Status = OFile->Error;
  if (EFI_ERROR (Status)) {
    return Status;
  }
  //
  // Get new OFile for the file
  //
  Status = FatLocateOFile (&OFile, FileName, Attributes, NewFileName);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  if (*NewFileName != 0) {
    //
    // If there's a remaining part of the name, then we had
    // better be creating the file in the directory
    //
    if ((OpenMode & EFI_FILE_MODE_CREATE) == 0) {
      return EFI_NOT_FOUND;
    }

    Status = FatCreateDirEnt (OFile, NewFileName, Attributes, &DirEnt);
    if (EFI_ERROR (Status)) {
      return Status;
    }

    Status = FatOpenDirEnt (OFile, DirEnt);
    if (EFI_ERROR (Status)) {
      return Status;
    }

    OFile = DirEnt->OFile;
    if (OFile->ODir != NULL) {
      //
      // If we just created a directory, we need to create "." and ".."
      //
      Status = FatCreateDotDirEnts (OFile);
      if (EFI_ERROR (Status)) {
        return Status;
      }
    }
  }
  //
  // If the file's attribute is read only, and the open is for
  // read-write, then the access is denied.
  //
  FileAttributes = OFile->DirEnt->Entry.Attributes;
  if ((FileAttributes & EFI_FILE_READ_ONLY) != 0 && (FileAttributes & FAT_ATTRIBUTE_DIRECTORY) == 0 && WriteMode) {
    return EFI_ACCESS_DENIED;
  }
  //
  // Create an open instance of the OFile
  //
  Status = FatAllocateIFile (OFile, NewIFile);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  (*NewIFile)->ReadOnly = (BOOLEAN)!WriteMode;

  DEBUG ((EFI_D_INFO, "FSOpen: Open '%S' %r\n", FileName, Status));
  return FatOFileFlush (OFile);
}

EFI_STATUS
EFIAPI
FatOpen (
  IN  EFI_FILE   *FHand,
  OUT EFI_FILE   **NewHandle,
  IN  CHAR16     *FileName,
  IN  UINT64     OpenMode,
  IN  UINT64     Attributes
  )
/*++
Routine Description:

  Implements Open() of Simple File System Protocol.

Arguments:

  FHand                 - File handle of the file serves as a starting reference point.
  NewHandle             - Handle of the file that is newly opened.
  FileName              - File name relative to FHand.
  OpenMode              - Open mode.
  Attributes            - Attributes to set if the file is created.

Returns:

  EFI_INVALID_PARAMETER - The FileName is NULL or the file string is empty.
                          The OpenMode is not supported.
                          The Attributes is not the valid attributes.
  EFI_OUT_OF_RESOURCES  - Can not allocate the memory for file string.
  EFI_SUCCESS           - Open the file successfully.
  Others                - The status of open file.

--*/
{
  FAT_IFILE   *IFile;
  FAT_IFILE   *NewIFile;
  FAT_OFILE   *OFile;
  EFI_STATUS  Status;

  //
  // Perform some parameter checking
  //
  if (FileName == NULL) {
    return EFI_INVALID_PARAMETER;
  }
  //
  // Check for a valid mode
  //
  switch (OpenMode) {
  case EFI_FILE_MODE_READ:
  case EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE:
  case EFI_FILE_MODE_READ | EFI_FILE_MODE_WRITE | EFI_FILE_MODE_CREATE:
    break;

  default:
    return EFI_INVALID_PARAMETER;
  }
  //
  // Check for valid attributes
  //
  if (Attributes & (~EFI_FILE_VALID_ATTR)) {
    return EFI_INVALID_PARAMETER;
  }
  //
  // Can't open for create and apply the read only attribute
  //
  if ((OpenMode & EFI_FILE_MODE_CREATE) && (Attributes & EFI_FILE_READ_ONLY)) {
    return EFI_INVALID_PARAMETER;
  }

  IFile = IFILE_FROM_FHAND (FHand);
  OFile = IFile->OFile;

  //
  // Lock
  //
  FatAcquireLock ();

  //
  // Open the file
  //
  Status = FatOFileOpen (OFile, &NewIFile, FileName, OpenMode, (UINT8) Attributes);

  //
  // If the file was opened, return the handle to the caller
  //
  if (!EFI_ERROR (Status)) {
    *NewHandle = &NewIFile->Handle;
  }
  //
  // Unlock
  //
  Status = FatCleanupVolume (OFile->Volume, NULL, Status);
  FatReleaseLock ();

  return Status;
}