mirror of
https://github.com/torvalds/linux.git
synced 2024-12-28 05:41:55 +00:00
1e94082963
This patch updates csum_ipv6_magic so that it correctly recognizes that protocol is a unsigned 8 bit value. This will allow us to better understand what limitations may or may not be present in how we handle the data. For example there are a number of places that call htonl on the protocol value. This is likely not necessary and can be replaced with a multiplication by ntohl(1) which will be converted to a shift by the compiler. Signed-off-by: Alexander Duyck <aduyck@mirantis.com> Signed-off-by: David S. Miller <davem@davemloft.net>
154 lines
3.7 KiB
C
154 lines
3.7 KiB
C
/*
|
|
* arch/arm/include/asm/checksum.h
|
|
*
|
|
* IP checksum routines
|
|
*
|
|
* Copyright (C) Original authors of ../asm-i386/checksum.h
|
|
* Copyright (C) 1996-1999 Russell King
|
|
*/
|
|
#ifndef __ASM_ARM_CHECKSUM_H
|
|
#define __ASM_ARM_CHECKSUM_H
|
|
|
|
#include <linux/in6.h>
|
|
|
|
/*
|
|
* computes the checksum of a memory block at buff, length len,
|
|
* and adds in "sum" (32-bit)
|
|
*
|
|
* returns a 32-bit number suitable for feeding into itself
|
|
* or csum_tcpudp_magic
|
|
*
|
|
* this function must be called with even lengths, except
|
|
* for the last fragment, which may be odd
|
|
*
|
|
* it's best to have buff aligned on a 32-bit boundary
|
|
*/
|
|
__wsum csum_partial(const void *buff, int len, __wsum sum);
|
|
|
|
/*
|
|
* the same as csum_partial, but copies from src while it
|
|
* checksums, and handles user-space pointer exceptions correctly, when needed.
|
|
*
|
|
* here even more important to align src and dst on a 32-bit (or even
|
|
* better 64-bit) boundary
|
|
*/
|
|
|
|
__wsum
|
|
csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);
|
|
|
|
__wsum
|
|
csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *err_ptr);
|
|
|
|
/*
|
|
* Fold a partial checksum without adding pseudo headers
|
|
*/
|
|
static inline __sum16 csum_fold(__wsum sum)
|
|
{
|
|
__asm__(
|
|
"add %0, %1, %1, ror #16 @ csum_fold"
|
|
: "=r" (sum)
|
|
: "r" (sum)
|
|
: "cc");
|
|
return (__force __sum16)(~(__force u32)sum >> 16);
|
|
}
|
|
|
|
/*
|
|
* This is a version of ip_compute_csum() optimized for IP headers,
|
|
* which always checksum on 4 octet boundaries.
|
|
*/
|
|
static inline __sum16
|
|
ip_fast_csum(const void *iph, unsigned int ihl)
|
|
{
|
|
unsigned int tmp1;
|
|
__wsum sum;
|
|
|
|
__asm__ __volatile__(
|
|
"ldr %0, [%1], #4 @ ip_fast_csum \n\
|
|
ldr %3, [%1], #4 \n\
|
|
sub %2, %2, #5 \n\
|
|
adds %0, %0, %3 \n\
|
|
ldr %3, [%1], #4 \n\
|
|
adcs %0, %0, %3 \n\
|
|
ldr %3, [%1], #4 \n\
|
|
1: adcs %0, %0, %3 \n\
|
|
ldr %3, [%1], #4 \n\
|
|
tst %2, #15 @ do this carefully \n\
|
|
subne %2, %2, #1 @ without destroying \n\
|
|
bne 1b @ the carry flag \n\
|
|
adcs %0, %0, %3 \n\
|
|
adc %0, %0, #0"
|
|
: "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (tmp1)
|
|
: "1" (iph), "2" (ihl)
|
|
: "cc", "memory");
|
|
return csum_fold(sum);
|
|
}
|
|
|
|
static inline __wsum
|
|
csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
|
|
__u8 proto, __wsum sum)
|
|
{
|
|
u32 lenprot = len + proto;
|
|
if (__builtin_constant_p(sum) && sum == 0) {
|
|
__asm__(
|
|
"adds %0, %1, %2 @ csum_tcpudp_nofold0 \n\t"
|
|
#ifdef __ARMEB__
|
|
"adcs %0, %0, %3 \n\t"
|
|
#else
|
|
"adcs %0, %0, %3, ror #8 \n\t"
|
|
#endif
|
|
"adc %0, %0, #0"
|
|
: "=&r" (sum)
|
|
: "r" (daddr), "r" (saddr), "r" (lenprot)
|
|
: "cc");
|
|
} else {
|
|
__asm__(
|
|
"adds %0, %1, %2 @ csum_tcpudp_nofold \n\t"
|
|
"adcs %0, %0, %3 \n\t"
|
|
#ifdef __ARMEB__
|
|
"adcs %0, %0, %4 \n\t"
|
|
#else
|
|
"adcs %0, %0, %4, ror #8 \n\t"
|
|
#endif
|
|
"adc %0, %0, #0"
|
|
: "=&r"(sum)
|
|
: "r" (sum), "r" (daddr), "r" (saddr), "r" (lenprot)
|
|
: "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));
|
|
}
|
|
|
|
|
|
/*
|
|
* this routine is used for miscellaneous IP-like checksums, mainly
|
|
* in icmp.c
|
|
*/
|
|
static inline __sum16
|
|
ip_compute_csum(const void *buff, int len)
|
|
{
|
|
return csum_fold(csum_partial(buff, len, 0));
|
|
}
|
|
|
|
#define _HAVE_ARCH_IPV6_CSUM
|
|
extern __wsum
|
|
__csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, __be32 len,
|
|
__be32 proto, __wsum sum);
|
|
|
|
static inline __sum16
|
|
csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
|
|
__u32 len, __u8 proto, __wsum sum)
|
|
{
|
|
return csum_fold(__csum_ipv6_magic(saddr, daddr, htonl(len),
|
|
htonl(proto), sum));
|
|
}
|
|
#endif
|