incubator-nuttx/include/nuttx/fs/procfs.h

302 lines
11 KiB
C

/****************************************************************************
* include/nuttx/fs/procfs.h
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_FS_PROCFS_H
#define __INCLUDE_NUTTX_FS_PROCFS_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/fs/fs.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Data entry declaration prototypes ****************************************/
/* Procfs operations are a subset of the mountpt_operations */
struct procfs_operations
{
/* The procfs open method differs from the driver open method
* because it receives (1) the inode that contains the procfs
* private data, (2) the relative path into the procfs, and (3)
* information to manage privileges.
*/
CODE int (*open)(FAR struct file *filep, FAR const char *relpath,
int oflags, mode_t mode);
/* The following methods must be identical in signature and position
* because the struct file_operations and struct mountpt_operations are
* treated like unions.
*/
CODE int (*close)(FAR struct file *filep);
CODE ssize_t (*read)(FAR struct file *filep, FAR char *buffer,
size_t buflen);
CODE ssize_t (*write)(FAR struct file *filep, FAR const char *buffer,
size_t buflen);
CODE int (*poll)(FAR struct file *filep, FAR struct pollfd *fds,
bool setup);
/* The two structures need not be common after this point. The following
* are extended methods needed to deal with the unique needs of mounted
* file systems.
*
* Additional open-file-specific procfs operations:
*/
CODE int (*dup)(FAR const struct file *oldp, FAR struct file *newp);
/* Directory operations */
CODE int (*opendir)(FAR const char *relpath,
FAR struct fs_dirent_s **dir);
CODE int (*closedir)(FAR struct fs_dirent_s *dir);
CODE int (*readdir)(FAR struct fs_dirent_s *dir,
FAR struct dirent *entry);
CODE int (*rewinddir)(FAR struct fs_dirent_s *dir);
/* Operations on paths */
CODE int (*stat)(FAR const char *relpath, FAR struct stat *buf);
};
/* Procfs handler prototypes ************************************************/
/* These are the types of entries that may appear in the procfs: */
enum procfs_entry_e
{
PROCFS_UNKOWN_TYPE = 0, /* Unknown type */
PROCFS_FILE_TYPE, /* File type */
PROCFS_DIR_TYPE, /* Directory type */
};
/* This is a procfs entry that each handler should provide to supply
* specific operations for file and directory handling.
*/
struct procfs_entry_s
{
FAR const char *pathpattern;
FAR const struct procfs_operations *ops;
uint8_t type;
};
/* Specifies the common elements for an open file in the procfs
* file system. This structure should be sub-classed by handlers
* to add their own specific data elements to the context.
*/
struct procfs_file_s
{
FAR const struct procfs_entry_s *procfsentry;
};
/* The generic proc/ pseudo directory structure */
struct procfs_dir_priv_s
{
struct fs_dirent_s dir; /* VFS directory structure */
uint8_t level; /* Directory level. Currently 0 or 1 */
uint16_t index; /* Index to the next directory entry */
uint16_t nentries; /* Number of directory entries */
FAR const struct procfs_entry_s *procfsentry; /* Pointer to procfs handler entry */
};
/* An entry for procfs_register_meminfo */
struct mm_heap_s;
struct procfs_meminfo_entry_s
{
FAR const char *name;
FAR struct mm_heap_s *heap;
FAR struct procfs_meminfo_entry_s *next;
#if CONFIG_MM_BACKTRACE >= 0
/* This is dynamic control flag whether to turn on backtrace in the heap,
* you can set it by /proc/memdump.
*/
bool backtrace;
#endif
};
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Name: procfs_memcpy
*
* Description:
* procfs/ file data may be read by the user with different user buffer
* sizes to receive the data. If the amount of data to be returned is
* large or if the callers receive buffer is small, then multiple read
* operations will be required.
*
* If multiple read operations are required, then each read operation will
* be identical accept that file position (f_pos) will be incremented with
* each read: f_pos must be incremented by the read method after each
* read operation to provide the 'offset' for the next read.
*
* procfs_memcpy() is a helper function. Each read() method should
* provide data in a local data buffer ('src' and 'srclen'). This
* will transfer the data to the user receive buffer ('dest' and
* 'destlen'), respecting both (1) the size of the destination buffer so
* that it will write beyond the user receiver and (1) the file position,
* 'offset'.
*
* This function will skip over data until the under of bytes specified
* by 'offset' have been skipped. Then it will transfer data from the
* the procfs/ 'src' buffer into the user receive buffer. No more than
* 'destlen' bytes will be transferred.
*
* Input Parameters:
* src - The address of the intermediate procfs/ buffer containing the
* data to be returned.
* srclen - The number of bytes of data in the 'src' buffer
* dest - The address of the user's receive buffer.
* destlen - The size (in bytes) of the user's receive buffer.
* offset - On input, this is the number of bytes to skip before returning
* data; If bytes were skipped, this offset will be decremented.
* Data will not be transferred until this offset decrements to
* zero.
*
* Returned Value:
* The number of bytes actually transferred into the user's receive buffer.
*
****************************************************************************/
size_t procfs_memcpy(FAR const char *src, size_t srclen,
FAR char *dest, size_t destlen,
FAR off_t *offset);
/****************************************************************************
* Name: procfs_snprintf
*
* Description:
* This function is same with snprintf, except return values.
* If buf has no enough space and output was truncated due to size limit,
* snprintf: return formatted string len.
* procfs_snprintf: return string len which has written to buf.
*
* Input Parameters:
* Same with snprintf
*
* Returned Value:
* See Description.
*
****************************************************************************/
int procfs_snprintf(FAR char *buf, size_t size,
FAR const IPTR char *format, ...) printf_like(3, 4);
/****************************************************************************
* Name: procfs_sprintf
*
* Description:
* This function used to continous format string and copy it to buffer.
* Every single string length must be smaller then LINEBUF_SIZE.
*
* Input Parameters:
* buf - The address of the user's receive buffer.
* size - The size (in bytes) of the user's receive buffer.
* offset - On input, when *offset is larger the 0 , this is the
* number of bytes to skip before returning data; If bytes
* were skipped, this *offset will be decremented. when it
* decrements to a negative value, -*offset is the number of
* data copied to buffer.
*
****************************************************************************/
void procfs_sprintf(FAR char *buf, size_t size, FAR off_t *offset,
FAR const IPTR char *format, ...) printf_like(4, 5);
/****************************************************************************
* Name: procfs_register
*
* Description:
* Add a new entry to the procfs file system.
*
* NOTE: This function should be called *prior* to mounting the procfs
* file system to prevent concurrency problems with the modification of
* the procfs data set while it is in use.
*
* Input Parameters:
* entry - Describes the entry to be registered.
*
* Returned Value:
* Zero (OK) on success; a negated errno value on failure
*
****************************************************************************/
#ifdef CONFIG_FS_PROCFS_REGISTER
int procfs_register(FAR const struct procfs_entry_s *entry);
#endif
/****************************************************************************
* Name: procfs_register_meminfo
*
* Description:
* Add a new meminfo entry to the procfs file system.
*
* Input Parameters:
* entry - Describes the entry to be registered.
*
****************************************************************************/
void procfs_register_meminfo(FAR struct procfs_meminfo_entry_s *entry);
/****************************************************************************
* Name: procfs_unregister_meminfo
*
* Description:
* Remove a meminfo entry from the procfs file system.
*
* Input Parameters:
* entry - Describes the entry to be unregistered.
*
****************************************************************************/
void procfs_unregister_meminfo(FAR struct procfs_meminfo_entry_s *entry);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* __INCLUDE_NUTTX_FS_PROCFS_H */