1 /***************************************************************************
2 * Copyright (c) 2024 Microsoft Corporation
3 *
4 * This program and the accompanying materials are made available under the
5 * terms of the MIT License which is available at
6 * https://opensource.org/licenses/MIT.
7 *
8 * SPDX-License-Identifier: MIT
9 **************************************************************************/
10
11
12 /**************************************************************************/
13 /**************************************************************************/
14 /** */
15 /** FileX Component */
16 /** */
17 /** File */
18 /** */
19 /**************************************************************************/
20 /**************************************************************************/
21
22 #define FX_SOURCE_CODE
23
24
25 /* Include necessary system files. */
26
27 #include "fx_api.h"
28 #include "fx_file.h"
29
30
31 FX_CALLER_CHECKING_EXTERNS
32
33
34 /**************************************************************************/
35 /* */
36 /* FUNCTION RELEASE */
37 /* */
38 /* _fxe_file_open PORTABLE C */
39 /* 6.1 */
40 /* AUTHOR */
41 /* */
42 /* William E. Lamie, Microsoft Corporation */
43 /* */
44 /* DESCRIPTION */
45 /* */
46 /* This function checks for errors in the file open call. */
47 /* */
48 /* INPUT */
49 /* */
50 /* media_ptr Media control block pointer */
51 /* file_ptr File control block pointer */
52 /* file_name Name pointer */
53 /* open_type Type of open requested */
54 /* file_control_block_size Size of FX_FILE structure */
55 /* */
56 /* OUTPUT */
57 /* */
58 /* return status */
59 /* */
60 /* CALLS */
61 /* */
62 /* _fx_file_open Actual open file service */
63 /* */
64 /* CALLED BY */
65 /* */
66 /* Application Code */
67 /* */
68 /* RELEASE HISTORY */
69 /* */
70 /* DATE NAME DESCRIPTION */
71 /* */
72 /* 05-19-2020 William E. Lamie Initial Version 6.0 */
73 /* 09-30-2020 William E. Lamie Modified comment(s), */
74 /* resulting in version 6.1 */
75 /* */
76 /**************************************************************************/
_fxe_file_open(FX_MEDIA * media_ptr,FX_FILE * file_ptr,CHAR * file_name,UINT open_type,UINT file_control_block_size)77 UINT _fxe_file_open(FX_MEDIA *media_ptr, FX_FILE *file_ptr, CHAR *file_name, UINT open_type, UINT file_control_block_size)
78 {
79
80 UINT status;
81 FX_FILE *current_file;
82 ULONG open_count;
83
84
85 /* Check for a null media or file pointer. */
86 if ((media_ptr == FX_NULL) || (media_ptr -> fx_media_id != FX_MEDIA_ID) || (file_ptr == FX_NULL) || (file_control_block_size != sizeof(FX_FILE)))
87 {
88 return(FX_PTR_ERROR);
89 }
90
91 /* Check for an invalid open type. */
92 if ((open_type != FX_OPEN_FOR_READ) && (open_type != FX_OPEN_FOR_READ_FAST) && (open_type != FX_OPEN_FOR_WRITE))
93 {
94 return(FX_ACCESS_ERROR);
95 }
96
97 /* Check for a valid caller. */
98 FX_CALLER_CHECKING_CODE
99
100 /* Get protection. */
101 FX_PROTECT
102
103 /* Check for a duplicate file open. */
104
105 /* Loop to search the list for the same file handle. */
106 current_file = media_ptr -> fx_media_opened_file_list;
107 open_count = media_ptr -> fx_media_opened_file_count;
108
109 while (open_count--)
110 {
111
112 /* See if a match exists. */
113 if (file_ptr == current_file)
114 {
115
116 /* Release protection. */
117 FX_UNPROTECT
118
119 /* Return error. */
120 return(FX_PTR_ERROR);
121 }
122
123 /* Move to the next opened file. */
124 current_file = current_file -> fx_file_opened_next;
125 }
126
127 /* Release protection. */
128 FX_UNPROTECT
129
130 /* Call actual file open service. */
131 status = _fx_file_open(media_ptr, file_ptr, file_name, open_type);
132
133 /* Open is complete, return status. */
134 return(status);
135 }
136
137
