OVMS3-idf/components/vfs/include/esp_vfs.h
2019-05-15 10:50:49 +02:00

405 lines
16 KiB
C

// Copyright 2015-2019 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 "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 <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 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);
ssize_t (*write)(int fd, const void * data, size_t size);
};
union {
off_t (*lseek_p)(void* p, int fd, off_t size, int mode);
off_t (*lseek)(int fd, off_t size, int mode);
};
union {
ssize_t (*read_p)(void* ctx, int fd, void * dst, size_t size);
ssize_t (*read)(int fd, void * dst, size_t size);
};
union {
int (*open_p)(void* ctx, const char * path, int flags, int mode);
int (*open)(const char * path, int flags, int mode);
};
union {
int (*close_p)(void* ctx, int fd);
int (*close)(int fd);
};
union {
int (*fstat_p)(void* ctx, int fd, struct stat * st);
int (*fstat)(int fd, struct stat * st);
};
union {
int (*stat_p)(void* ctx, const char * path, struct stat * st);
int (*stat)(const char * path, struct stat * st);
};
union {
int (*link_p)(void* ctx, const char* n1, const char* n2);
int (*link)(const char* n1, const char* n2);
};
union {
int (*unlink_p)(void* ctx, const char *path);
int (*unlink)(const char *path);
};
union {
int (*rename_p)(void* ctx, const char *src, const char *dst);
int (*rename)(const char *src, const char *dst);
};
union {
DIR* (*opendir_p)(void* ctx, const char* name);
DIR* (*opendir)(const char* name);
};
union {
struct dirent* (*readdir_p)(void* ctx, DIR* pdir);
struct dirent* (*readdir)(DIR* pdir);
};
union {
int (*readdir_r_p)(void* ctx, DIR* pdir, struct dirent* entry, struct dirent** out_dirent);
int (*readdir_r)(DIR* pdir, struct dirent* entry, struct dirent** out_dirent);
};
union {
long (*telldir_p)(void* ctx, DIR* pdir);
long (*telldir)(DIR* pdir);
};
union {
void (*seekdir_p)(void* ctx, DIR* pdir, long offset);
void (*seekdir)(DIR* pdir, long offset);
};
union {
int (*closedir_p)(void* ctx, DIR* pdir);
int (*closedir)(DIR* pdir);
};
union {
int (*mkdir_p)(void* ctx, const char* name, mode_t mode);
int (*mkdir)(const char* name, mode_t mode);
};
union {
int (*rmdir_p)(void* ctx, const char* name);
int (*rmdir)(const char* name);
};
union {
int (*fcntl_p)(void* ctx, int fd, int cmd, va_list args);
int (*fcntl)(int fd, int cmd, va_list args);
};
union {
int (*ioctl_p)(void* ctx, int fd, int cmd, va_list args);
int (*ioctl)(int fd, int cmd, va_list args);
};
union {
int (*fsync_p)(void* ctx, int fd);
int (*fsync)(int fd);
};
union {
int (*access_p)(void* ctx, const char *path, int amode);
int (*access)(const char *path, int amode);
};
union {
int (*truncate_p)(void* ctx, const char *path, off_t length);
int (*truncate)(const char *path, off_t length);
};
#ifdef CONFIG_SUPPORT_TERMIOS
union {
int (*tcsetattr_p)(void *ctx, int fd, int optional_actions, const struct termios *p);
int (*tcsetattr)(int fd, int optional_actions, const struct termios *p);
};
union {
int (*tcgetattr_p)(void *ctx, int fd, struct termios *p);
int (*tcgetattr)(int fd, struct termios *p);
};
union {
int (*tcdrain_p)(void *ctx, int fd);
int (*tcdrain)(int fd);
};
union {
int (*tcflush_p)(void *ctx, int fd, int select);
int (*tcflush)(int fd, int select);
};
union {
int (*tcflow_p)(void *ctx, int fd, int action);
int (*tcflow)(int fd, int action);
};
union {
pid_t (*tcgetsid_p)(void *ctx, int fd);
pid_t (*tcgetsid)(int fd);
};
union {
int (*tcsendbreak_p)(void *ctx, int fd, int duration);
int (*tcsendbreak)(int fd, int duration);
};
#endif // CONFIG_SUPPORT_TERMIOS
/** 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, SemaphoreHandle_t *signal_sem);
/** 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)();
/** stop_socket_select which can be called from ISR; set only for the socket driver */
void (*stop_socket_select_isr)(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)();
/** get_socket_select_semaphore returns semaphore allocated in the socket driver; set only for the socket driver */
void (*end_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, 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".
* @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);
/**
* 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 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);
/**@}*/
/**
* @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 signal_sem semaphore handle which was passed to the driver by the start_select call
*/
void esp_vfs_select_triggered(SemaphoreHandle_t *signal_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 signal_sem semaphore handle 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(SemaphoreHandle_t *signal_sem, BaseType_t *woken);
/**
* @brief Implements the VFS layer for synchronous I/O multiplexing by poll()
*
* The implementation is based on esp_vfs_select. The parameters and return values are compatible with POSIX poll().
*
* @param fds Pointer to the array containing file descriptors and events poll() should consider.
* @param nfds Number of items in the array fds.
* @param timeout Poll() should wait at least timeout milliseconds. If the value is 0 then it should return
* immediately. If the value is -1 then it should wait (block) until the event occurs.
*
* @return A positive return value indicates the number of file descriptors that have been selected. The 0
* return value indicates a timed-out poll. -1 is return on failure and errno is set accordingly.
*
*/
int esp_vfs_poll(struct pollfd *fds, nfds_t nfds, int timeout);
#ifdef __cplusplus
} // extern "C"
#endif
#endif //__ESP_VFS_H__