58 lines
1.3 KiB
C
58 lines
1.3 KiB
C
#ifndef __LINUX_UIO_H
|
|
#define __LINUX_UIO_H
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/types.h>
|
|
|
|
/*
|
|
* Berkeley style UIO structures - Alan Cox 1994.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
struct iovec
|
|
{
|
|
void __user *iov_base; /* BSD uses caddr_t (1003.1g requires void *) */
|
|
__kernel_size_t iov_len; /* Must be size_t (1003.1g) */
|
|
};
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
struct kvec {
|
|
void *iov_base; /* and that should *never* hold a userland pointer */
|
|
size_t iov_len;
|
|
};
|
|
|
|
#endif
|
|
|
|
/*
|
|
* UIO_MAXIOV shall be at least 16 1003.1g (5.4.1.1)
|
|
*/
|
|
|
|
#define UIO_FASTIOV 8
|
|
#define UIO_MAXIOV 1024
|
|
|
|
/*
|
|
* Total number of bytes covered by an iovec.
|
|
*
|
|
* NOTE that it is not safe to use this function until all the iovec's
|
|
* segment lengths have been validated. Because the individual lengths can
|
|
* overflow a size_t when added together.
|
|
*/
|
|
static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
|
|
{
|
|
unsigned long seg;
|
|
size_t ret = 0;
|
|
|
|
for (seg = 0; seg < nr_segs; seg++)
|
|
ret += iov[seg].iov_len;
|
|
return ret;
|
|
}
|
|
|
|
unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to);
|
|
|
|
#endif
|