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
|
/****************************************************************************
* fs/fs_fdopen.c
*
* Copyright (C) 2007-2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdio.h>
#include <string.h>
#include <semaphore.h>
#include <fcntl.h>
#include <errno.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs.h>
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: fs_fdopen
****************************************************************************/
FAR struct file_struct *fs_fdopen(int fd, int oflags, FAR _TCB *tcb)
{
FAR struct filelist *flist;
FAR struct streamlist *slist;
FAR struct inode *inode;
FAR FILE *stream;
int err = OK;
int ret;
int i;
/* Check input parameters */
if (fd < 0)
{
err = EBADF;
goto errout;
}
/* A NULL TCB pointer means to use this threads TCB. This is a little
* hack the let's this function be called from user-space (via a syscall)
* without having access to the TCB.
*/
if (!tcb)
{
tcb = sched_self();
}
/* Get the file and stream list from the TCB */
flist = tcb->filelist;
slist = tcb->streams;
/* Get the inode associated with the file descriptor. This should
* normally be the case if fd >= 0. But not in the case where the
* called attempts to explictly stdin with fdopen(0) but stdin has
* been closed.
*/
inode = flist->fl_files[fd].f_inode;
if (!inode)
{
err = ENOENT;
goto errout;
}
/* Make sure that the inode supports the requested access. In
* the case of fdopen, we are not actually creating the file -- in
* particular w and w+ do not truncate the file and any files have
* already been created.
*/
if (inode_checkflags(inode, oflags) != OK)
{
err = EACCES;
goto errout;
}
/* Find an unallocated FILE structure */
ret = sem_wait(&slist->sl_sem);
if (ret != OK)
{
goto errout_with_errno;
}
for (i = 0 ; i < CONFIG_NFILE_STREAMS; i++)
{
stream = &slist->sl_streams[i];
if (stream->fs_filedes < 0)
{
/* Zero the structure */
#if CONFIG_STDIO_BUFFER_SIZE > 0
memset(stream, 0, sizeof(FILE));
#elif CONFIG_NUNGET_CHARS > 0
stream->fs_nungotten = 0;
#endif
#if CONFIG_STDIO_BUFFER_SIZE > 0
/* Initialize the semaphore the manages access to the buffer */
(void)sem_init(&stream->fs_sem, 0, 1);
/* Allocate the IO buffer */
stream->fs_bufstart = kmalloc(CONFIG_STDIO_BUFFER_SIZE);
if (!stream)
{
err = ENOMEM;
goto errout_with_sem;
}
/* Set up pointers */
stream->fs_bufend = &stream->fs_bufstart[CONFIG_STDIO_BUFFER_SIZE];
stream->fs_bufpos = stream->fs_bufstart;
stream->fs_bufpos = stream->fs_bufstart;
stream->fs_bufread = stream->fs_bufstart;
#endif
/* Save the file description and open flags. Setting the
* file descriptor locks this stream.
*/
stream->fs_filedes = fd;
stream->fs_oflags = oflags;
sem_post(&slist->sl_sem);
return stream;
}
}
#if CONFIG_STDIO_BUFFER_SIZE > 0
errout_with_sem:
#endif
sem_post(&slist->sl_sem);
errout:
set_errno(err);
errout_with_errno:
return NULL;
}
|
