linux/arch/mn10300/include/asm/checksum.h
Alexander Duyck 01cfbad79a ipv4: Update parameters for csum_tcpudp_magic to their original types
This patch updates all instances of csum_tcpudp_magic and
csum_tcpudp_nofold to reflect the types that are usually used as the source
inputs.  For example the protocol field is populated based on nexthdr which
is actually an unsigned 8 bit value.  The length is usually populated based
on skb->len which is an unsigned integer.

This addresses an issue in which the IPv6 function csum_ipv6_magic was
generating a checksum using the full 32b of skb->len while
csum_tcpudp_magic was only using the lower 16 bits.  As a result we could
run into issues when attempting to adjust the checksum as there was no
protocol agnostic way to update it.

With this change the value is still truncated as many architectures use
"(len + proto) << 8", however this truncation only occurs for values
greater than 16776960 in length and as such is unlikely to occur as we stop
the inner headers at ~64K in size.

I did have to make a few minor changes in the arm, mn10300, nios2, and
score versions of the function in order to support these changes as they
were either using things such as an OR to combine the protocol and length,
or were using ntohs to convert the length which would have truncated the
value.

I also updated a few spots in terms of whitespace and type differences for
the addresses.  Most of this was just to make sure all of the definitions
were in sync going forward.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-13 23:55:13 -04:00

80 lines
2.1 KiB
C

/* MN10300 Optimised checksumming code
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#ifndef _ASM_CHECKSUM_H
#define _ASM_CHECKSUM_H
extern __wsum csum_partial(const void *buff, int len, __wsum sum);
extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
int len, __wsum sum);
extern __wsum csum_partial_copy_from_user(const void *src, void *dst,
int len, __wsum sum,
int *err_ptr);
extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
extern __wsum csum_partial(const void *buff, int len, __wsum sum);
extern __sum16 ip_compute_csum(const void *buff, int len);
#define csum_partial_copy_fromuser csum_partial_copy
extern __wsum csum_partial_copy(const void *src, void *dst, int len,
__wsum sum);
static inline __sum16 csum_fold(__wsum sum)
{
asm(
" add %1,%0 \n"
" addc 0xffff,%0 \n"
: "=r" (sum)
: "r" (sum << 16), "0" (sum & 0xffff0000)
: "cc"
);
return (~sum) >> 16;
}
static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
__u32 len, __u8 proto,
__wsum sum)
{
__wsum tmp = (__wsum)((len + proto) << 8);
asm(
" add %1,%0 \n"
" addc %2,%0 \n"
" addc %3,%0 \n"
" addc 0,%0 \n"
: "=r" (sum)
: "r" (daddr), "r"(saddr), "r"(tmp), "0"(sum)
: "cc"
);
return sum;
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
__u32 len, __u8 proto,
__wsum sum)
{
return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
}
#undef _HAVE_ARCH_IPV6_CSUM
/*
* Copy and checksum to user
*/
#define HAVE_CSUM_COPY_USER
extern __wsum csum_and_copy_to_user(const void *src, void *dst, int len,
__wsum sum, int *err_ptr);
#endif /* _ASM_CHECKSUM_H */