file.h

 
#ifndef KERNEL_FILE_H
#define KERNEL_FILE_H
 
#include <kernel/atomic.h>
#include <kernel/error.h>
#include <kernel/spinlock.h>
 
#include <sys/fcntl.h>
 
struct vnode;
struct sockaddr;
struct msghdr;
 
#define FD_STDIN 0
#define FD_STDOUT 1
#define FD_STDERR 2
 
/*
 * File description flag.
 *
 * These are set when opening a file description (open, socket, ...) or by
 * using other syscalls (e.g. fcntl).
 */
enum file_flags {
    FD_READ = _FREAD,
    FD_WRITE = _FWRITE,
    FD_RW = FD_READ | FD_WRITE,
    FD_APPEND = _FAPPEND,
    FD_NOINHERIT = _FNOINHERIT, /* FD_CLOEXEC is already defined by fcntl(). */
};
 
struct file {
    off_t pos;                         
    void *priv;                        
    struct vnode *vnode;               
    const struct file_operations *ops; 
    atomic_t refcount;                 
    spinlock_t lock;                   
    int flags;                         
};
 
void __file_put(struct file *file);
 
static inline struct file *file_get(struct file *file)
{
    atomic_inc(&file->refcount);
    return file;
}
 
static inline void file_put(struct file *file)
{
    int count;
 
    count = atomic_dec(&file->refcount);
    if (count > 1)
        return;
 
    __file_put(file);
}
 
struct file_operations {
    error_t (*open)(struct file *);
    void (*close)(struct file *);
    ssize_t (*write)(struct file *, const char *, size_t);
    ssize_t (*read)(struct file *, char *, size_t);
    size_t (*size)(struct file *);
    error_t (*bind)(struct file *, struct sockaddr *addr, size_t len);
    error_t (*connect)(struct file *, struct sockaddr *addr, size_t len);
    ssize_t (*sendmsg)(struct file *, const struct msghdr *, int flags);
    ssize_t (*recvmsg)(struct file *, struct msghdr *, int flags);
    off_t (*seek)(struct file *, off_t, int whence);
};
 
struct file *file_open(struct vnode *, const struct file_operations *);
 
off_t default_file_seek(struct file *file, off_t off, int whence);
 
static inline void file_close(struct file *file)
{
    file_put(file);
}
 
void file_accessed(struct file *file);
void file_modified(struct file *file);
 
#define __file_ops(_default, _file, _ops, ...)                             \
    (_file->ops->_ops ? _file->ops->_ops(_file __VA_OPT__(, ) __VA_ARGS__) \
                      : _default)
 
#define file_ops(_file, _ops, ...) \
    __file_ops(E_NOT_SUPPORTED, _file, _ops, __VA_ARGS__)
 
#define file_size(file) file_ops(file, size)
 
#define file_write(file, buf, len) file_ops(file, write, buf, len)
#define file_read(file, buf, len) file_ops(file, read, buf, len)
#define file_seek(file, off, whence) file_ops(file, seek, off, whence)
 
#define file_bind(file, addr, len) file_ops(file, bind, addr, len)
#define file_connect(file, addr, len) file_ops(file, connect, addr, len)
 
#define file_sendmsg(file, msg, flags) file_ops(file, sendmsg, msg, flags)
ssize_t file_send(struct file *file, const char *data, size_t len, int flags);
ssize_t file_sendto(struct file *file, const char *data, size_t len, int flags,
                    struct sockaddr *addr, size_t addrlen);
 
#define file_recvmsg(file, msg, flags) file_ops(file, recvmsg, msg, flags)
ssize_t file_recv(struct file *file, const char *data, size_t len, int flags);
ssize_t file_recvfrom(struct file *file, const char *data, size_t len,
                      int flags, struct sockaddr *addr, size_t *addrlen);
 
#endif /* KERNEL_FILE_H */