151 lines
4.5 KiB
C
151 lines
4.5 KiB
C
/*
|
|
* Copyright (c) 2018 Linaro Limited
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
#ifndef ZEPHYR_INCLUDE_SYS_FDTABLE_H_
|
|
#define ZEPHYR_INCLUDE_SYS_FDTABLE_H_
|
|
|
|
#include <stdarg.h>
|
|
#include <sys/types.h>
|
|
/* FIXME: For native_posix ssize_t, off_t. */
|
|
#include <fs/fs.h>
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
/**
|
|
* File descriptor virtual method table.
|
|
* All operations beyond read/write go thru ioctl method.
|
|
*/
|
|
struct fd_op_vtable {
|
|
ssize_t (*read)(void *obj, void *buf, size_t sz);
|
|
ssize_t (*write)(void *obj, const void *buf, size_t sz);
|
|
int (*ioctl)(void *obj, unsigned int request, va_list args);
|
|
};
|
|
|
|
/**
|
|
* @brief Reserve file descriptor.
|
|
*
|
|
* This function allows to reserve a space for file descriptor entry in
|
|
* the underlying table, and thus allows caller to fail fast if no free
|
|
* descriptor is available. If this function succeeds, z_finalize_fd()
|
|
* or z_free_fd() must be called mandatorily.
|
|
*
|
|
* @return Allocated file descriptor, or -1 in case of error (errno is set)
|
|
*/
|
|
int z_reserve_fd(void);
|
|
|
|
/**
|
|
* @brief Finalize creation of file descriptor.
|
|
*
|
|
* This function should be called exactly once after z_reserve_fd(), and
|
|
* should not be called in any other case.
|
|
*
|
|
* @param fd File descriptor previously returned by z_reserve_fd()
|
|
* @param obj pointer to I/O object structure
|
|
* @param vtable pointer to I/O operation implementations for the object
|
|
*/
|
|
void z_finalize_fd(int fd, void *obj, const struct fd_op_vtable *vtable);
|
|
|
|
/**
|
|
* @brief Allocate file descriptor for underlying I/O object.
|
|
*
|
|
* This function combines operations of z_reserve_fd() and z_finalize_fd()
|
|
* in one step, and provided for convenience.
|
|
*
|
|
* @param obj pointer to I/O object structure
|
|
* @param vtable pointer to I/O operation implementations for the object
|
|
*
|
|
* @return Allocated file descriptor, or -1 in case of error (errno is set)
|
|
*/
|
|
int z_alloc_fd(void *obj, const struct fd_op_vtable *vtable);
|
|
|
|
/**
|
|
* @brief Release reserved file descriptor.
|
|
*
|
|
* This function may be called once after z_reserve_fd(), and should
|
|
* not be called in any other case.
|
|
*
|
|
* @param fd File descriptor previously returned by z_reserve_fd()
|
|
*/
|
|
void z_free_fd(int fd);
|
|
|
|
/**
|
|
* @brief Get underlying object pointer from file descriptor.
|
|
*
|
|
* This function is useful for functions other than read/write/ioctl
|
|
* to look up underlying I/O object by fd, optionally checking its
|
|
* type (using vtable reference). If fd refers to invalid entry,
|
|
* NULL will be returned with errno set to EBADF. If fd is valid,
|
|
* but vtable param is not NULL and doesn't match object's vtable,
|
|
* NULL is returned and errno set to err param.
|
|
*
|
|
* @param fd File descriptor previously returned by z_reserve_fd()
|
|
* @param vtable Expected object vtable or NULL
|
|
* @param err errno value to set if object vtable doesn't match
|
|
*
|
|
* @return Object pointer or NULL, with errno set
|
|
*/
|
|
void *z_get_fd_obj(int fd, const struct fd_op_vtable *vtable, int err);
|
|
|
|
/**
|
|
* @brief Get underlying object pointer and vtable pointer from file descriptor.
|
|
*
|
|
* @param fd File descriptor previously returned by z_reserve_fd()
|
|
* @param vtable A pointer to a pointer variable to store the vtable
|
|
*
|
|
* @return Object pointer or NULL, with errno set
|
|
*/
|
|
void *z_get_fd_obj_and_vtable(int fd, const struct fd_op_vtable **vtable);
|
|
|
|
/**
|
|
* @brief Call ioctl vmethod on an object using varargs.
|
|
*
|
|
* We need this helper function because ioctl vmethod is declared to
|
|
* take va_list and the only portable way to construct va_list is from
|
|
* function's ... parameters.
|
|
*
|
|
* @param vtable vtable containing ioctl function pointer
|
|
* @param obj Object to call ioctl on
|
|
* @param request ioctl request number
|
|
* @param ... Variadic arguments to ioctl
|
|
*/
|
|
static inline int z_fdtable_call_ioctl(const struct fd_op_vtable *vtable, void *obj,
|
|
unsigned long request, ...)
|
|
{
|
|
va_list args;
|
|
int res;
|
|
|
|
va_start(args, request);
|
|
res = vtable->ioctl(obj, request, args);
|
|
va_end(args);
|
|
|
|
return res;
|
|
}
|
|
|
|
/**
|
|
* Request codes for fd_op_vtable.ioctl().
|
|
*
|
|
* Note that these codes are internal Zephyr numbers, for internal
|
|
* Zephyr operations (and subject to change without notice, not part
|
|
* of "stable ABI"). These are however expected to co-exist with
|
|
* "well-known" POSIX/Linux ioctl numbers, and not clash with them.
|
|
*/
|
|
enum {
|
|
/* Codes below 0x100 are reserved for fcntl() codes. */
|
|
ZFD_IOCTL_CLOSE = 0x100,
|
|
ZFD_IOCTL_FSYNC,
|
|
ZFD_IOCTL_LSEEK,
|
|
ZFD_IOCTL_POLL_PREPARE,
|
|
ZFD_IOCTL_POLL_UPDATE,
|
|
ZFD_IOCTL_GETSOCKNAME,
|
|
};
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
#endif /* ZEPHYR_INCLUDE_SYS_FDTABLE_H_ */
|