/****************************************************************************
* fs/procfs/fs_skeleton.c
*
* Copyright (C) 2015 Ken Pettit. All rights reserved.
* Author: Ken Pettit <pettitkd@gmail.com>
*
* 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 <sys/types.h>
#include <sys/statfs.h>
#include <sys/stat.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/arch.h>
#include <nuttx/sched.h>
#include <nuttx/kmalloc.h>
#include <nuttx/fs/fs.h>
#include <nuttx/fs/procfs.h>
#include <nuttx/fs/dirent.h>
#include <arch/irq.h>
#if !defined(CONFIG_DISABLE_MOUNTPOINT) && defined(CONFIG_FS_PROCFS)
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/* This enumeration identifies all of the thread attributes that can be
* accessed via the procfs file system.
*/
/* This structure describes one open "file" */
struct skel_file_s
{
struct procfs_file_s base; /* Base open file structure */
/* Add context specific data types for managing an open file here */
};
/* Level 1 is the directory of attributes */
struct skel_level1_s
{
struct procfs_dir_priv_s base; /* Base directory private data */
/* Add context specific data types here for managing the directory
* open / read / stat, etc.
*/
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* File system methods */
static int skel_open(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode);
static int skel_close(FAR struct file *filep);
static ssize_t skel_read(FAR struct file *filep, FAR char *buffer,
size_t buflen);
static int skel_dup(FAR const struct file *oldp,
FAR struct file *newp);
static int skel_opendir(FAR const char *relpath,
FAR struct fs_dirent_s *dir);
static int skel_closedir(FAR struct fs_dirent_s *dir);
static int skel_readdir(FAR struct fs_dirent_s *dir);
static int skel_rewinddir(FAR struct fs_dirent_s *dir);
static int skel_stat(FAR const char *relpath, FAR struct stat *buf);
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/* See include/nutts/fs/procfs.h
* We use the old-fashioned kind of initializers so that this will compile
* with any compiler.
*/
const struct procfs_operations skel_procfsoperations =
{
skel_open, /* open */
skel_close, /* close */
skel_read, /* read */
/* TODO: Decide if this driver supports write */
NULL, /* write */
skel_dup, /* dup */
skel_opendir, /* opendir */
skel_closedir, /* closedir */
skel_readdir, /* readdir */
skel_rewinddir, /* rewinddir */
skel_stat /* stat */
};
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: skel_open
****************************************************************************/
static int skel_open(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode)
{
FAR struct skel_file_s *priv;
fvdbg("Open '%s'\n", relpath);
/* PROCFS is read-only. Any attempt to open with any kind of write
* access is not permitted.
*
* REVISIT: Write-able proc files could be quite useful.
*/
if (((oflags & O_WRONLY) != 0 || (oflags & O_RDONLY) == 0) &&
(skel_procfsoperations.write == NULL))
{
fdbg("ERROR: Only O_RDONLY supported\n");
return -EACCES;
}
/* Allocate the open file structure */
priv = (FAR struct skel_file_s *)kmm_zalloc(sizeof(struct skel_file_s));
if (!priv)
{
fdbg("ERROR: Failed to allocate file attributes\n");
return -ENOMEM;
}
/* TODO: Initialize the context specific data here */
/* Save the open file structure as the open-specific state in
* filep->f_priv.
*/
filep->f_priv = (FAR void *)priv;
return OK;
}
/****************************************************************************
* Name: skel_close
****************************************************************************/
static int skel_close(FAR struct file *filep)
{
FAR struct skel_file_s *priv;
/* Recover our private data from the struct file instance */
priv = (FAR struct skel_file_s *)filep->f_priv;
DEBUGASSERT(priv);
/* Release the file attributes structure */
kmm_free(priv);
filep->f_priv = NULL;
return OK;
}
/****************************************************************************
* Name: skel_read
****************************************************************************/
static ssize_t skel_read(FAR struct file *filep, FAR char *buffer,
size_t buflen)
{
FAR struct skel_file_s *priv;
ssize_t ret;
fvdbg("buffer=%p buflen=%d\n", buffer, (int)buflen);
/* Recover our private data from the struct file instance */
priv = (FAR struct skel_file_s *)filep->f_priv;
DEBUGASSERT(priv);
/* TODO: Provide the requested data */
ret = 0;
/* Update the file offset */
if (ret > 0)
{
filep->f_pos += ret;
}
return ret;
}
/****************************************************************************
* Name: skel_dup
*
* Description:
* Duplicate open file data in the new file structure.
*
****************************************************************************/
static int skel_dup(FAR const struct file *oldp, FAR struct file *newp)
{
FAR struct skel_file_s *oldpriv;
FAR struct skel_file_s *newpriv;
fvdbg("Dup %p->%p\n", oldp, newp);
/* Recover our private data from the old struct file instance */
oldpriv = (FAR struct skel_file_s *)oldp->f_priv;
DEBUGASSERT(oldpriv);
/* Allocate a new container to hold the task and attribute selection */
newpriv = (FAR struct skel_file_s *)kmm_zalloc(sizeof(struct skel_file_s));
if (!newpriv)
{
fdbg("ERROR: Failed to allocate file attributes\n");
return -ENOMEM;
}
/* The copy the file attribtes from the old attributes to the new */
memcpy(newpriv, oldpriv, sizeof(struct skel_file_s));
/* Save the new attributes in the new file structure */
newp->f_priv = (FAR void *)newpriv;
return OK;
}
/****************************************************************************
* Name: skel_opendir
*
* Description:
* Open a directory for read access
*
****************************************************************************/
static int skel_opendir(FAR const char *relpath, FAR struct fs_dirent_s *dir)
{
FAR struct skel_level1_s *level1;
fvdbg("relpath: \"%s\"\n", relpath ? relpath : "NULL");
DEBUGASSERT(relpath && dir && !dir->u.procfs);
/* The path refers to the 1st level sbdirectory. Allocate the level1
* dirent structure.
*/
level1 = (FAR struct skel_level1_s *)
kmm_zalloc(sizeof(struct skel_level1_s));
if (!level1)
{
fdbg("ERROR: Failed to allocate the level1 directory structure\n");
return -ENOMEM;
}
/* TODO: Initialze context specific data */
/* Initialze base structure components */
level1->base.level = 1;
level1->base.nentries = 0;
level1->base.index = 0;
dir->u.procfs = (FAR void *) level1;
return OK;
}
/****************************************************************************
* Name: skel_closedir
*
* Description: Close the directory listing
*
****************************************************************************/
static int skel_closedir(FAR struct fs_dirent_s *dir)
{
FAR struct skel_level1_s *priv;
DEBUGASSERT(dir && dir->u.procfs);
priv = dir->u.procfs;
if (priv)
{
kmm_free(priv);
}
dir->u.procfs = NULL;
return OK;
}
/****************************************************************************
* Name: skel_readdir
*
* Description: Read the next directory entry
*
****************************************************************************/
static int skel_readdir(FAR struct fs_dirent_s *dir)
{
FAR struct skel_level1_s *level1;
char filename[16];
int index;
int ret;
DEBUGASSERT(dir && dir->u.procfs);
level1 = dir->u.procfs;
/* TODO: Perform device specific readdir function here. This may
* or may not involve validating the nentries variable
* in the base depending on the implementation.
*/
/* Have we reached the end of the directory */
index = level1->base.index;
if (index >= level1->base.nentries)
{
/* We signal the end of the directory by returning the special
* error -ENOENT
*/
fvdbg("Entry %d: End of directory\n", index);
ret = -ENOENT;
}
/* We are tranversing a subdirectory of task attributes */
else
{
DEBUGASSERT(level1->base.level == 1);
/* TODO: Add device specific entries */
strcpy(filename, "dummy");
/* TODO: Specify the type of entry */
dir->fd_dir.d_type = DTYPE_FILE;
strncpy(dir->fd_dir.d_name, filename, NAME_MAX + 1);
/* Set up the next directory entry offset. NOTE that we could use the
* standard f_pos instead of our own private index.
*/
level1->base.index = index + 1;
ret = OK;
}
return ret;
}
/****************************************************************************
* Name: skel_rewindir
*
* Description: Reset directory read to the first entry
*
****************************************************************************/
static int skel_rewinddir(FAR struct fs_dirent_s *dir)
{
FAR struct skel_level1_s *priv;
DEBUGASSERT(dir && dir->u.procfs);
priv = dir->u.procfs;
priv->base.index = 0;
return OK;
}
/****************************************************************************
* Name: skel_stat
*
* Description: Return information about a file or directory
*
****************************************************************************/
static int skel_stat(FAR const char *relpath, FAR truct stat *buf)
{
int ret = -ENOENT;
/* TODO: Decide if the relpath is valid and if it is a file
* or a directory and set it's permissions.
*/
buf->st_mode = S_IFDIR | S_IROTH | S_IRGRP | S_IRUSR;
ret = OK;
/* File/directory size, access block size */
buf->st_size = 0;
buf->st_blksize = 0;
buf->st_blocks = 0;
return ret;
}
/****************************************************************************
* Public Functions
****************************************************************************/
#endif /* !CONFIG_DISABLE_MOUNTPOINT && CONFIG_FS_PROCFS */