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261 lines
7.2 KiB
261 lines
7.2 KiB
/**************************************************************************** |
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* fs/fs_fdopen.c |
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* |
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* Copyright (C) 2007-2012 Gregory Nutt. All rights reserved. |
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* Author: Gregory Nutt <gnutt@nuttx.org> |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in |
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* the documentation and/or other materials provided with the |
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* distribution. |
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* 3. Neither the name NuttX nor the names of its contributors may be |
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* used to endorse or promote products derived from this software |
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* without specific prior written permission. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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* POSSIBILITY OF SUCH DAMAGE. |
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* |
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****************************************************************************/ |
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/**************************************************************************** |
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* Included Files |
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****************************************************************************/ |
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#include <nuttx/config.h> |
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#include <stdio.h> |
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#include <string.h> |
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#include <semaphore.h> |
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#include <fcntl.h> |
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#include <errno.h> |
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#include <nuttx/kmalloc.h> |
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#include <nuttx/fs/fs.h> |
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#include <nuttx/net/net.h> |
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/**************************************************************************** |
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* Private Functions |
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****************************************************************************/ |
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/**************************************************************************** |
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* Name: fs_checkfd |
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* |
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* Description: |
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* Check if the file descriptor is valid for the provided TCB and if it |
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* supports the requested access. |
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* |
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****************************************************************************/ |
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#if CONFIG_NFILE_DESCRIPTORS > 0 |
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static inline int fs_checkfd(FAR _TCB *tcb, int fd, int oflags) |
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{ |
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FAR struct filelist *flist; |
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FAR struct inode *inode; |
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/* Get the file list from the TCB */ |
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flist = tcb->filelist; |
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/* Get the inode associated with the file descriptor. This should |
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* normally be the case if fd >= 0. But not in the case where the |
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* called attempts to explictly stdin with fdopen(0) but stdin has |
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* been closed. |
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*/ |
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inode = flist->fl_files[fd].f_inode; |
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if (!inode) |
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{ |
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/* No inode -- descriptor does not correspond to an open file */ |
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return -ENOENT; |
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} |
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/* Make sure that the inode supports the requested access. In |
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* the case of fdopen, we are not actually creating the file -- in |
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* particular w and w+ do not truncate the file and any files have |
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* already been created. |
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*/ |
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if (inode_checkflags(inode, oflags) != OK) |
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{ |
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/* Cannot support the requested access */ |
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return -EACCES; |
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} |
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/* Looks good to me */ |
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return OK; |
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} |
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#endif |
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/**************************************************************************** |
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* Public Functions |
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****************************************************************************/ |
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/**************************************************************************** |
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* Name: fs_fdopen |
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* |
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* Description: |
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* This function does the core operations for fopen and fdopen. |
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* |
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****************************************************************************/ |
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FAR struct file_struct *fs_fdopen(int fd, int oflags, FAR _TCB *tcb) |
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{ |
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FAR struct streamlist *slist; |
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FAR FILE *stream; |
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int err = OK; |
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int ret; |
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int i; |
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/* Check input parameters */ |
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if (fd < 0) |
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{ |
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err = EBADF; |
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goto errout; |
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} |
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/* A NULL TCB pointer means to use this threads TCB. This is a little |
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* hack the let's this function be called from user-space (via a syscall) |
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* without having access to the TCB. |
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*/ |
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if (!tcb) |
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{ |
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tcb = sched_self(); |
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} |
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/* Verify that this is a valid file/socket descriptor and that the |
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* requested access can be support. |
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* |
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* Is this fd in the range of valid file descriptors? Socket descriptors |
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* lie in a different range. |
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*/ |
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#if CONFIG_NFILE_DESCRIPTORS > 0 |
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if ((unsigned int)fd >= CONFIG_NFILE_DESCRIPTORS) |
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#endif |
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{ |
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/* No.. If networking is enabled then this might be a socket |
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* descriptor. |
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*/ |
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#if defined(CONFIG_NET) && CONFIG_NSOCKET_DESCRIPTORS > 0 |
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ret = net_checksd(fd, oflags); |
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#else |
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/* No networking... it is just a bad descriptor */ |
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err = EBADF; |
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goto errout; |
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#endif |
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} |
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/* The descriptor is in a valid range to file descriptor... perform some more checks */ |
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#if CONFIG_NFILE_DESCRIPTORS > 0 |
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else |
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{ |
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ret = fs_checkfd(tcb, fd, oflags); |
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} |
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#endif |
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/* Do we have a good descriptor of some sort? */ |
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if (ret < 0) |
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{ |
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/* No... return the reported error */ |
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err = -ret; |
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goto errout; |
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} |
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/* Get the stream list from the TCB */ |
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slist = tcb->streams; |
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/* Find an unallocated FILE structure in the stream list */ |
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ret = sem_wait(&slist->sl_sem); |
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if (ret != OK) |
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{ |
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goto errout_with_errno; |
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} |
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for (i = 0 ; i < CONFIG_NFILE_STREAMS; i++) |
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{ |
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stream = &slist->sl_streams[i]; |
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if (stream->fs_filedes < 0) |
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{ |
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/* Zero the structure */ |
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#if CONFIG_STDIO_BUFFER_SIZE > 0 |
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memset(stream, 0, sizeof(FILE)); |
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#elif CONFIG_NUNGET_CHARS > 0 |
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stream->fs_nungotten = 0; |
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#endif |
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#if CONFIG_STDIO_BUFFER_SIZE > 0 |
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/* Initialize the semaphore the manages access to the buffer */ |
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(void)sem_init(&stream->fs_sem, 0, 1); |
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/* Allocate the IO buffer */ |
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stream->fs_bufstart = kmalloc(CONFIG_STDIO_BUFFER_SIZE); |
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if (!stream) |
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{ |
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err = ENOMEM; |
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goto errout_with_sem; |
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} |
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/* Set up pointers */ |
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stream->fs_bufend = &stream->fs_bufstart[CONFIG_STDIO_BUFFER_SIZE]; |
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stream->fs_bufpos = stream->fs_bufstart; |
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stream->fs_bufpos = stream->fs_bufstart; |
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stream->fs_bufread = stream->fs_bufstart; |
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#endif |
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/* Save the file description and open flags. Setting the |
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* file descriptor locks this stream. |
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*/ |
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stream->fs_filedes = fd; |
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stream->fs_oflags = (uint16_t)oflags; |
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sem_post(&slist->sl_sem); |
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return stream; |
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} |
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} |
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/* No free stream available.. report ENFILE */ |
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err = ENFILE; |
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#if CONFIG_STDIO_BUFFER_SIZE > 0 |
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errout_with_sem: |
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#endif |
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sem_post(&slist->sl_sem); |
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errout: |
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set_errno(err); |
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errout_with_errno: |
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return NULL; |
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}
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