esp-idf/components/vfs/include/esp_vfs.h

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24 KiB
C

// Copyright 2015-2020 Espressif Systems (Shanghai) PTE LTD
//
// Licensed 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 __ESP_VFS_H__
#define __ESP_VFS_H__
#include <stdint.h>
#include <stddef.h>
#include <stdarg.h>
#include <unistd.h>
#include <utime.h>
#include "freertos/FreeRTOS.h"
#include "freertos/semphr.h"
#include "esp_err.h"
#include <sys/types.h>
#include <sys/reent.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/termios.h>
#include <sys/poll.h>
#include <sys/dirent.h>
#include <string.h>
#include "sdkconfig.h"
#ifdef __cplusplus
extern "C" {
#endif
#ifndef _SYS_TYPES_FD_SET
#error "VFS should be used with FD_SETSIZE and FD_SET from sys/types.h"
#endif
/**
* Maximum number of (global) file descriptors.
*/
#define MAX_FDS FD_SETSIZE /* for compatibility with fd_set and select() */
/**
* Maximum length of path prefix (not including zero terminator)
*/
#define ESP_VFS_PATH_MAX 15
/**
* Default value of flags member in esp_vfs_t structure.
*/
#define ESP_VFS_FLAG_DEFAULT 0
/**
* Flag which indicates that FS needs extra context pointer in syscalls.
*/
#define ESP_VFS_FLAG_CONTEXT_PTR 1
/*
* @brief VFS identificator used for esp_vfs_register_with_id()
*/
typedef int esp_vfs_id_t;
/**
* @brief VFS semaphore type for select()
*
*/
typedef struct
{
bool is_sem_local; /*!< type of "sem" is SemaphoreHandle_t when true, defined by socket driver otherwise */
void *sem; /*!< semaphore instance */
} esp_vfs_select_sem_t;
/**
* @brief VFS definition structure
*
* This structure should be filled with pointers to corresponding
* FS driver functions.
*
* VFS component will translate all FDs so that the filesystem implementation
* sees them starting at zero. The caller sees a global FD which is prefixed
* with an pre-filesystem-implementation.
*
* Some FS implementations expect some state (e.g. pointer to some structure)
* to be passed in as a first argument. For these implementations,
* populate the members of this structure which have _p suffix, set
* flags member to ESP_VFS_FLAG_CONTEXT_PTR and provide the context pointer
* to esp_vfs_register function.
* If the implementation doesn't use this extra argument, populate the
* members without _p suffix and set flags member to ESP_VFS_FLAG_DEFAULT.
*
* If the FS driver doesn't provide some of the functions, set corresponding
* members to NULL.
*/
typedef struct
{
int flags; /*!< ESP_VFS_FLAG_CONTEXT_PTR or ESP_VFS_FLAG_DEFAULT */
union {
ssize_t (*write_p)(void* p, int fd, const void * data, size_t size); /*!< Write with context pointer */
ssize_t (*write)(int fd, const void * data, size_t size); /*!< Write without context pointer */
};
union {
off_t (*lseek_p)(void* p, int fd, off_t size, int mode); /*!< Seek with context pointer */
off_t (*lseek)(int fd, off_t size, int mode); /*!< Seek without context pointer */
};
union {
ssize_t (*read_p)(void* ctx, int fd, void * dst, size_t size); /*!< Read with context pointer */
ssize_t (*read)(int fd, void * dst, size_t size); /*!< Read without context pointer */
};
union {
ssize_t (*pread_p)(void *ctx, int fd, void * dst, size_t size, off_t offset); /*!< pread with context pointer */
ssize_t (*pread)(int fd, void * dst, size_t size, off_t offset); /*!< pread without context pointer */
};
union {
ssize_t (*pwrite_p)(void *ctx, int fd, const void *src, size_t size, off_t offset); /*!< pwrite with context pointer */
ssize_t (*pwrite)(int fd, const void *src, size_t size, off_t offset); /*!< pwrite without context pointer */
};
union {
int (*open_p)(void* ctx, const char * path, int flags, int mode); /*!< open with context pointer */
int (*open)(const char * path, int flags, int mode); /*!< open without context pointer */
};
union {
int (*close_p)(void* ctx, int fd); /*!< close with context pointer */
int (*close)(int fd); /*!< close without context pointer */
};
union {
int (*fstat_p)(void* ctx, int fd, struct stat * st); /*!< fstat with context pointer */
int (*fstat)(int fd, struct stat * st); /*!< fstat without context pointer */
};
#ifdef CONFIG_VFS_SUPPORT_DIR
union {
int (*stat_p)(void* ctx, const char * path, struct stat * st); /*!< stat with context pointer */
int (*stat)(const char * path, struct stat * st); /*!< stat without context pointer */
};
union {
int (*link_p)(void* ctx, const char* n1, const char* n2); /*!< link with context pointer */
int (*link)(const char* n1, const char* n2); /*!< link without context pointer */
};
union {
int (*unlink_p)(void* ctx, const char *path); /*!< unlink with context pointer */
int (*unlink)(const char *path); /*!< unlink without context pointer */
};
union {
int (*rename_p)(void* ctx, const char *src, const char *dst); /*!< rename with context pointer */
int (*rename)(const char *src, const char *dst); /*!< rename without context pointer */
};
union {
DIR* (*opendir_p)(void* ctx, const char* name); /*!< opendir with context pointer */
DIR* (*opendir)(const char* name); /*!< opendir without context pointer */
};
union {
struct dirent* (*readdir_p)(void* ctx, DIR* pdir); /*!< readdir with context pointer */
struct dirent* (*readdir)(DIR* pdir); /*!< readdir without context pointer */
};
union {
int (*readdir_r_p)(void* ctx, DIR* pdir, struct dirent* entry, struct dirent** out_dirent); /*!< readdir_r with context pointer */
int (*readdir_r)(DIR* pdir, struct dirent* entry, struct dirent** out_dirent); /*!< readdir_r without context pointer */
};
union {
long (*telldir_p)(void* ctx, DIR* pdir); /*!< telldir with context pointer */
long (*telldir)(DIR* pdir); /*!< telldir without context pointer */
};
union {
void (*seekdir_p)(void* ctx, DIR* pdir, long offset); /*!< seekdir with context pointer */
void (*seekdir)(DIR* pdir, long offset); /*!< seekdir without context pointer */
};
union {
int (*closedir_p)(void* ctx, DIR* pdir); /*!< closedir with context pointer */
int (*closedir)(DIR* pdir); /*!< closedir without context pointer */
};
union {
int (*mkdir_p)(void* ctx, const char* name, mode_t mode); /*!< mkdir with context pointer */
int (*mkdir)(const char* name, mode_t mode); /*!< mkdir without context pointer */
};
union {
int (*rmdir_p)(void* ctx, const char* name); /*!< rmdir with context pointer */
int (*rmdir)(const char* name); /*!< rmdir without context pointer */
};
#endif // CONFIG_VFS_SUPPORT_DIR
union {
int (*fcntl_p)(void* ctx, int fd, int cmd, int arg); /*!< fcntl with context pointer */
int (*fcntl)(int fd, int cmd, int arg); /*!< fcntl without context pointer */
};
union {
int (*ioctl_p)(void* ctx, int fd, int cmd, va_list args); /*!< ioctl with context pointer */
int (*ioctl)(int fd, int cmd, va_list args); /*!< ioctl without context pointer */
};
union {
int (*fsync_p)(void* ctx, int fd); /*!< fsync with context pointer */
int (*fsync)(int fd); /*!< fsync without context pointer */
};
#ifdef CONFIG_VFS_SUPPORT_DIR
union {
int (*access_p)(void* ctx, const char *path, int amode); /*!< access with context pointer */
int (*access)(const char *path, int amode); /*!< access without context pointer */
};
union {
int (*truncate_p)(void* ctx, const char *path, off_t length); /*!< truncate with context pointer */
int (*truncate)(const char *path, off_t length); /*!< truncate without context pointer */
};
union {
int (*utime_p)(void* ctx, const char *path, const struct utimbuf *times); /*!< utime with context pointer */
int (*utime)(const char *path, const struct utimbuf *times); /*!< utime without context pointer */
};
#endif // CONFIG_VFS_SUPPORT_DIR
#ifdef CONFIG_VFS_SUPPORT_TERMIOS
union {
int (*tcsetattr_p)(void *ctx, int fd, int optional_actions, const struct termios *p); /*!< tcsetattr with context pointer */
int (*tcsetattr)(int fd, int optional_actions, const struct termios *p); /*!< tcsetattr without context pointer */
};
union {
int (*tcgetattr_p)(void *ctx, int fd, struct termios *p); /*!< tcgetattr with context pointer */
int (*tcgetattr)(int fd, struct termios *p); /*!< tcgetattr without context pointer */
};
union {
int (*tcdrain_p)(void *ctx, int fd); /*!< tcdrain with context pointer */
int (*tcdrain)(int fd); /*!< tcdrain without context pointer */
};
union {
int (*tcflush_p)(void *ctx, int fd, int select); /*!< tcflush with context pointer */
int (*tcflush)(int fd, int select); /*!< tcflush without context pointer */
};
union {
int (*tcflow_p)(void *ctx, int fd, int action); /*!< tcflow with context pointer */
int (*tcflow)(int fd, int action); /*!< tcflow without context pointer */
};
union {
pid_t (*tcgetsid_p)(void *ctx, int fd); /*!< tcgetsid with context pointer */
pid_t (*tcgetsid)(int fd); /*!< tcgetsid without context pointer */
};
union {
int (*tcsendbreak_p)(void *ctx, int fd, int duration); /*!< tcsendbreak with context pointer */
int (*tcsendbreak)(int fd, int duration); /*!< tcsendbreak without context pointer */
};
#endif // CONFIG_VFS_SUPPORT_TERMIOS
#ifdef CONFIG_VFS_SUPPORT_SELECT
/** start_select is called for setting up synchronous I/O multiplexing of the desired file descriptors in the given VFS */
esp_err_t (*start_select)(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, esp_vfs_select_sem_t sem, void **end_select_args);
/** socket select function for socket FDs with the functionality of POSIX select(); this should be set only for the socket VFS */
int (*socket_select)(int nfds, fd_set *readfds, fd_set *writefds, fd_set *errorfds, struct timeval *timeout);
/** called by VFS to interrupt the socket_select call when select is activated from a non-socket VFS driver; set only for the socket driver */
void (*stop_socket_select)(void *sem);
/** stop_socket_select which can be called from ISR; set only for the socket driver */
void (*stop_socket_select_isr)(void *sem, BaseType_t *woken);
/** end_select is called to stop the I/O multiplexing and deinitialize the environment created by start_select for the given VFS */
void* (*get_socket_select_semaphore)(void);
/** get_socket_select_semaphore returns semaphore allocated in the socket driver; set only for the socket driver */
esp_err_t (*end_select)(void *end_select_args);
#endif // CONFIG_VFS_SUPPORT_SELECT
} esp_vfs_t;
/**
* Register a virtual filesystem for given path prefix.
*
* @param base_path file path prefix associated with the filesystem.
* Must be a zero-terminated C string, may be empty.
* If not empty, must be up to ESP_VFS_PATH_MAX
* characters long, and at least 2 characters long.
* Name must start with a "/" and must not end with "/".
* For example, "/data" or "/dev/spi" are valid.
* These VFSes would then be called to handle file paths such as
* "/data/myfile.txt" or "/dev/spi/0".
* In the special case of an empty base_path, a "fallback"
* VFS is registered. Such VFS will handle paths which are not
* matched by any other registered VFS.
* @param vfs Pointer to esp_vfs_t, a structure which maps syscalls to
* the filesystem driver functions. VFS component doesn't
* assume ownership of this pointer.
* @param ctx If vfs->flags has ESP_VFS_FLAG_CONTEXT_PTR set, a pointer
* which should be passed to VFS functions. Otherwise, NULL.
*
* @return ESP_OK if successful, ESP_ERR_NO_MEM if too many VFSes are
* registered.
*/
esp_err_t esp_vfs_register(const char* base_path, const esp_vfs_t* vfs, void* ctx);
/**
* Special case function for registering a VFS that uses a method other than
* open() to open new file descriptors from the interval <min_fd; max_fd).
*
* This is a special-purpose function intended for registering LWIP sockets to VFS.
*
* @param vfs Pointer to esp_vfs_t. Meaning is the same as for esp_vfs_register().
* @param ctx Pointer to context structure. Meaning is the same as for esp_vfs_register().
* @param min_fd The smallest file descriptor this VFS will use.
* @param max_fd Upper boundary for file descriptors this VFS will use (the biggest file descriptor plus one).
*
* @return ESP_OK if successful, ESP_ERR_NO_MEM if too many VFSes are
* registered, ESP_ERR_INVALID_ARG if the file descriptor boundaries
* are incorrect.
*/
esp_err_t esp_vfs_register_fd_range(const esp_vfs_t *vfs, void *ctx, int min_fd, int max_fd);
/**
* Special case function for registering a VFS that uses a method other than
* open() to open new file descriptors. In comparison with
* esp_vfs_register_fd_range, this function doesn't pre-registers an interval
* of file descriptors. File descriptors can be registered later, by using
* esp_vfs_register_fd.
*
* @param vfs Pointer to esp_vfs_t. Meaning is the same as for esp_vfs_register().
* @param ctx Pointer to context structure. Meaning is the same as for esp_vfs_register().
* @param vfs_id Here will be written the VFS ID which can be passed to
* esp_vfs_register_fd for registering file descriptors.
*
* @return ESP_OK if successful, ESP_ERR_NO_MEM if too many VFSes are
* registered, ESP_ERR_INVALID_ARG if the file descriptor boundaries
* are incorrect.
*/
esp_err_t esp_vfs_register_with_id(const esp_vfs_t *vfs, void *ctx, esp_vfs_id_t *vfs_id);
/**
* Unregister a virtual filesystem for given path prefix
*
* @param base_path file prefix previously used in esp_vfs_register call
* @return ESP_OK if successful, ESP_ERR_INVALID_STATE if VFS for given prefix
* hasn't been registered
*/
esp_err_t esp_vfs_unregister(const char* base_path);
/**
* Unregister a virtual filesystem with the given index
*
* @param vfs_id The VFS ID returned by esp_vfs_register_with_id
* @return ESP_OK if successful, ESP_ERR_INVALID_STATE if VFS for the given index
* hasn't been registered
*/
esp_err_t esp_vfs_unregister_with_id(esp_vfs_id_t vfs_id);
/**
* Special function for registering another file descriptor for a VFS registered
* by esp_vfs_register_with_id.
*
* @param vfs_id VFS identificator returned by esp_vfs_register_with_id.
* @param fd The registered file descriptor will be written to this address.
*
* @return ESP_OK if the registration is successful,
* ESP_ERR_NO_MEM if too many file descriptors are registered,
* ESP_ERR_INVALID_ARG if the arguments are incorrect.
*/
esp_err_t esp_vfs_register_fd(esp_vfs_id_t vfs_id, int *fd);
/**
* Special function for registering another file descriptor with given local_fd
* for a VFS registered by esp_vfs_register_with_id.
*
* @param vfs_id VFS identificator returned by esp_vfs_register_with_id.
* @param local_fd The fd in the local vfs. Passing -1 will set the local fd as the (*fd) value.
* @param permanent Whether the fd should be treated as permannet (not removed after close())
* @param fd The registered file descriptor will be written to this address.
*
* @return ESP_OK if the registration is successful,
* ESP_ERR_NO_MEM if too many file descriptors are registered,
* ESP_ERR_INVALID_ARG if the arguments are incorrect.
*/
esp_err_t esp_vfs_register_fd_with_local_fd(esp_vfs_id_t vfs_id, int local_fd, bool permanent, int *fd);
/**
* Special function for unregistering a file descriptor belonging to a VFS
* registered by esp_vfs_register_with_id.
*
* @param vfs_id VFS identificator returned by esp_vfs_register_with_id.
* @param fd File descriptor which should be unregistered.
*
* @return ESP_OK if the registration is successful,
* ESP_ERR_INVALID_ARG if the arguments are incorrect.
*/
esp_err_t esp_vfs_unregister_fd(esp_vfs_id_t vfs_id, int fd);
/**
* These functions are to be used in newlib syscall table. They will be called by
* newlib when it needs to use any of the syscalls.
*/
/**@{*/
ssize_t esp_vfs_write(struct _reent *r, int fd, const void * data, size_t size);
off_t esp_vfs_lseek(struct _reent *r, int fd, off_t size, int mode);
ssize_t esp_vfs_read(struct _reent *r, int fd, void * dst, size_t size);
int esp_vfs_open(struct _reent *r, const char * path, int flags, int mode);
int esp_vfs_close(struct _reent *r, int fd);
int esp_vfs_fstat(struct _reent *r, int fd, struct stat * st);
int esp_vfs_stat(struct _reent *r, const char * path, struct stat * st);
int esp_vfs_link(struct _reent *r, const char* n1, const char* n2);
int esp_vfs_unlink(struct _reent *r, const char *path);
int esp_vfs_rename(struct _reent *r, const char *src, const char *dst);
int esp_vfs_utime(const char *path, const struct utimbuf *times);
/**@}*/
/**
* @brief Synchronous I/O multiplexing which implements the functionality of POSIX select() for VFS
* @param nfds Specifies the range of descriptors which should be checked.
* The first nfds descriptors will be checked in each set.
* @param readfds If not NULL, then points to a descriptor set that on input
* specifies which descriptors should be checked for being
* ready to read, and on output indicates which descriptors
* are ready to read.
* @param writefds If not NULL, then points to a descriptor set that on input
* specifies which descriptors should be checked for being
* ready to write, and on output indicates which descriptors
* are ready to write.
* @param errorfds If not NULL, then points to a descriptor set that on input
* specifies which descriptors should be checked for error
* conditions, and on output indicates which descriptors
* have error conditions.
* @param timeout If not NULL, then points to timeval structure which
* specifies the time period after which the functions should
* time-out and return. If it is NULL, then the function will
* not time-out.
*
* @return The number of descriptors set in the descriptor sets, or -1
* when an error (specified by errno) have occurred.
*/
int esp_vfs_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *errorfds, struct timeval *timeout);
/**
* @brief Notification from a VFS driver about a read/write/error condition
*
* This function is called when the VFS driver detects a read/write/error
* condition as it was requested by the previous call to start_select.
*
* @param sem semaphore structure which was passed to the driver by the start_select call
*/
void esp_vfs_select_triggered(esp_vfs_select_sem_t sem);
/**
* @brief Notification from a VFS driver about a read/write/error condition (ISR version)
*
* This function is called when the VFS driver detects a read/write/error
* condition as it was requested by the previous call to start_select.
*
* @param sem semaphore structure which was passed to the driver by the start_select call
* @param woken is set to pdTRUE if the function wakes up a task with higher priority
*/
void esp_vfs_select_triggered_isr(esp_vfs_select_sem_t sem, BaseType_t *woken);
/**
*
* @brief Implements the VFS layer of POSIX pread()
*
* @param fd File descriptor used for read
* @param dst Pointer to the buffer where the output will be written
* @param size Number of bytes to be read
* @param offset Starting offset of the read
*
* @return A positive return value indicates the number of bytes read. -1 is return on failure and errno is
* set accordingly.
*/
ssize_t esp_vfs_pread(int fd, void *dst, size_t size, off_t offset);
/**
*
* @brief Implements the VFS layer of POSIX pwrite()
*
* @param fd File descriptor used for write
* @param src Pointer to the buffer from where the output will be read
* @param size Number of bytes to write
* @param offset Starting offset of the write
*
* @return A positive return value indicates the number of bytes written. -1 is return on failure and errno is
* set accordingly.
*/
ssize_t esp_vfs_pwrite(int fd, const void *src, size_t size, off_t offset);
#ifdef __cplusplus
} // extern "C"
#endif
#endif //__ESP_VFS_H__