alistair23-linux/include/net/checksum.h
Joe Perches 4fc7074703 checksum: Remove extern from function prototypes
There are a mix of function prototypes with and without extern
in the kernel sources.  Standardize on not using extern for
function prototypes.

Function prototypes don't need to be written with extern.
extern is assumed by the compiler.  Its use is as unnecessary as
using auto to declare automatic/local variables in a block.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-31 17:50:02 -07:00

125 lines
3.2 KiB
C

/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Checksumming functions for IP, TCP, UDP and so on
*
* Authors: Jorge Cwik, <jorge@laser.satlink.net>
* Arnt Gulbrandsen, <agulbra@nvg.unit.no>
* Borrows very liberally from tcp.c and ip.c, see those
* files for more names.
*
* 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.
*/
#ifndef _CHECKSUM_H
#define _CHECKSUM_H
#include <linux/errno.h>
#include <asm/types.h>
#include <asm/byteorder.h>
#include <asm/uaccess.h>
#include <asm/checksum.h>
#ifndef _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
static inline
__wsum csum_and_copy_from_user (const void __user *src, void *dst,
int len, __wsum sum, int *err_ptr)
{
if (access_ok(VERIFY_READ, src, len))
return csum_partial_copy_from_user(src, dst, len, sum, err_ptr);
if (len)
*err_ptr = -EFAULT;
return sum;
}
#endif
#ifndef HAVE_CSUM_COPY_USER
static __inline__ __wsum csum_and_copy_to_user
(const void *src, void __user *dst, int len, __wsum sum, int *err_ptr)
{
sum = csum_partial(src, len, sum);
if (access_ok(VERIFY_WRITE, dst, len)) {
if (copy_to_user(dst, src, len) == 0)
return sum;
}
if (len)
*err_ptr = -EFAULT;
return (__force __wsum)-1; /* invalid checksum */
}
#endif
static inline __wsum csum_add(__wsum csum, __wsum addend)
{
u32 res = (__force u32)csum;
res += (__force u32)addend;
return (__force __wsum)(res + (res < (__force u32)addend));
}
static inline __wsum csum_sub(__wsum csum, __wsum addend)
{
return csum_add(csum, ~addend);
}
static inline __wsum
csum_block_add(__wsum csum, __wsum csum2, int offset)
{
u32 sum = (__force u32)csum2;
if (offset&1)
sum = ((sum&0xFF00FF)<<8)+((sum>>8)&0xFF00FF);
return csum_add(csum, (__force __wsum)sum);
}
static inline __wsum
csum_block_sub(__wsum csum, __wsum csum2, int offset)
{
u32 sum = (__force u32)csum2;
if (offset&1)
sum = ((sum&0xFF00FF)<<8)+((sum>>8)&0xFF00FF);
return csum_sub(csum, (__force __wsum)sum);
}
static inline __wsum csum_unfold(__sum16 n)
{
return (__force __wsum)n;
}
#define CSUM_MANGLED_0 ((__force __sum16)0xffff)
static inline void csum_replace4(__sum16 *sum, __be32 from, __be32 to)
{
__be32 diff[] = { ~from, to };
*sum = csum_fold(csum_partial(diff, sizeof(diff), ~csum_unfold(*sum)));
}
static inline void csum_replace2(__sum16 *sum, __be16 from, __be16 to)
{
csum_replace4(sum, (__force __be32)from, (__force __be32)to);
}
struct sk_buff;
void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
__be32 from, __be32 to, int pseudohdr);
void inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb,
const __be32 *from, const __be32 *to,
int pseudohdr);
static inline void inet_proto_csum_replace2(__sum16 *sum, struct sk_buff *skb,
__be16 from, __be16 to,
int pseudohdr)
{
inet_proto_csum_replace4(sum, skb, (__force __be32)from,
(__force __be32)to, pseudohdr);
}
#endif