mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 18:14:07 +08:00
e97288386a
to it in an asm() block, and we're running on a system with 64-bit registers, it is vitally important that we sign extend it correctly before returning to C. Otherwise the stray high bits will be preserved into csum_fold, and on the SB-1 processor, 32-bit arithmetic on a non sign-extended register will yield surprising results. This caused incorrect checksums in some UDP packets for NFS root. The problem was mild when using a 10.0.1.x IP address, but severe when using 192.168.1.x. Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
257 lines
5.6 KiB
C
257 lines
5.6 KiB
C
/*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file "COPYING" in the main directory of this archive
|
|
* for more details.
|
|
*
|
|
* Copyright (C) 1995, 96, 97, 98, 99, 2001 by Ralf Baechle
|
|
* Copyright (C) 1999 Silicon Graphics, Inc.
|
|
* Copyright (C) 2001 Thiemo Seufer.
|
|
* Copyright (C) 2002 Maciej W. Rozycki
|
|
*/
|
|
#ifndef _ASM_CHECKSUM_H
|
|
#define _ASM_CHECKSUM_H
|
|
|
|
#include <linux/config.h>
|
|
#include <linux/in6.h>
|
|
|
|
#include <asm/uaccess.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
|
|
*/
|
|
unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum);
|
|
|
|
/*
|
|
* this is a new version of the above that records errors it finds in *errp,
|
|
* but continues and zeros the rest of the buffer.
|
|
*/
|
|
unsigned int csum_partial_copy_from_user(const unsigned char __user *src,
|
|
unsigned char *dst, int len,
|
|
unsigned int sum, int *errp);
|
|
|
|
/*
|
|
* Copy and checksum to user
|
|
*/
|
|
#define HAVE_CSUM_COPY_USER
|
|
static inline unsigned int csum_and_copy_to_user (const unsigned char *src,
|
|
unsigned char __user *dst,
|
|
int len, int sum,
|
|
int *err_ptr)
|
|
{
|
|
might_sleep();
|
|
sum = csum_partial(src, len, sum);
|
|
|
|
if (copy_to_user(dst, src, len)) {
|
|
*err_ptr = -EFAULT;
|
|
return -1;
|
|
}
|
|
|
|
return sum;
|
|
}
|
|
|
|
/*
|
|
* the same as csum_partial, but copies from user space (but on MIPS
|
|
* we have just one address space, so this is identical to the above)
|
|
*/
|
|
unsigned int csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst,
|
|
int len, unsigned int sum);
|
|
|
|
/*
|
|
* Fold a partial checksum without adding pseudo headers
|
|
*/
|
|
static inline unsigned short int csum_fold(unsigned int sum)
|
|
{
|
|
__asm__(
|
|
" .set push # csum_fold\n"
|
|
" .set noat \n"
|
|
" sll $1, %0, 16 \n"
|
|
" addu %0, $1 \n"
|
|
" sltu $1, %0, $1 \n"
|
|
" srl %0, %0, 16 \n"
|
|
" addu %0, $1 \n"
|
|
" xori %0, 0xffff \n"
|
|
" .set pop"
|
|
: "=r" (sum)
|
|
: "0" (sum));
|
|
|
|
return sum;
|
|
}
|
|
|
|
/*
|
|
* This is a version of ip_compute_csum() optimized for IP headers,
|
|
* which always checksum on 4 octet boundaries.
|
|
*
|
|
* By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
|
|
* Arnt Gulbrandsen.
|
|
*/
|
|
static inline unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl)
|
|
{
|
|
unsigned int *word = (unsigned int *) iph;
|
|
unsigned int *stop = word + ihl;
|
|
unsigned int csum;
|
|
int carry;
|
|
|
|
csum = word[0];
|
|
csum += word[1];
|
|
carry = (csum < word[1]);
|
|
csum += carry;
|
|
|
|
csum += word[2];
|
|
carry = (csum < word[2]);
|
|
csum += carry;
|
|
|
|
csum += word[3];
|
|
carry = (csum < word[3]);
|
|
csum += carry;
|
|
|
|
word += 4;
|
|
do {
|
|
csum += *word;
|
|
carry = (csum < *word);
|
|
csum += carry;
|
|
word++;
|
|
} while (word != stop);
|
|
|
|
return csum_fold(csum);
|
|
}
|
|
|
|
static inline unsigned int csum_tcpudp_nofold(unsigned long saddr,
|
|
unsigned long daddr, unsigned short len, unsigned short proto,
|
|
unsigned int sum)
|
|
{
|
|
__asm__(
|
|
" .set push # csum_tcpudp_nofold\n"
|
|
" .set noat \n"
|
|
#ifdef CONFIG_32BIT
|
|
" addu %0, %2 \n"
|
|
" sltu $1, %0, %2 \n"
|
|
" addu %0, $1 \n"
|
|
|
|
" addu %0, %3 \n"
|
|
" sltu $1, %0, %3 \n"
|
|
" addu %0, $1 \n"
|
|
|
|
" addu %0, %4 \n"
|
|
" sltu $1, %0, %4 \n"
|
|
" addu %0, $1 \n"
|
|
#endif
|
|
#ifdef CONFIG_64BIT
|
|
" daddu %0, %2 \n"
|
|
" daddu %0, %3 \n"
|
|
" daddu %0, %4 \n"
|
|
" dsll32 $1, %0, 0 \n"
|
|
" daddu %0, $1 \n"
|
|
" dsra32 %0, %0, 0 \n"
|
|
#endif
|
|
" .set pop"
|
|
: "=r" (sum)
|
|
: "0" (daddr), "r"(saddr),
|
|
#ifdef __MIPSEL__
|
|
"r" (((unsigned long)htons(len)<<16) + proto*256),
|
|
#else
|
|
"r" (((unsigned long)(proto)<<16) + len),
|
|
#endif
|
|
"r" (sum));
|
|
|
|
return sum;
|
|
}
|
|
|
|
/*
|
|
* computes the checksum of the TCP/UDP pseudo-header
|
|
* returns a 16-bit checksum, already complemented
|
|
*/
|
|
static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
|
|
unsigned long daddr,
|
|
unsigned short len,
|
|
unsigned short proto,
|
|
unsigned int 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 unsigned short ip_compute_csum(unsigned char * buff, int len)
|
|
{
|
|
return csum_fold(csum_partial(buff, len, 0));
|
|
}
|
|
|
|
#define _HAVE_ARCH_IPV6_CSUM
|
|
static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
|
|
struct in6_addr *daddr,
|
|
__u32 len,
|
|
unsigned short proto,
|
|
unsigned int sum)
|
|
{
|
|
__asm__(
|
|
" .set push # csum_ipv6_magic\n"
|
|
" .set noreorder \n"
|
|
" .set noat \n"
|
|
" addu %0, %5 # proto (long in network byte order)\n"
|
|
" sltu $1, %0, %5 \n"
|
|
" addu %0, $1 \n"
|
|
|
|
" addu %0, %6 # csum\n"
|
|
" sltu $1, %0, %6 \n"
|
|
" lw %1, 0(%2) # four words source address\n"
|
|
" addu %0, $1 \n"
|
|
" addu %0, %1 \n"
|
|
" sltu $1, %0, %1 \n"
|
|
|
|
" lw %1, 4(%2) \n"
|
|
" addu %0, $1 \n"
|
|
" addu %0, %1 \n"
|
|
" sltu $1, %0, %1 \n"
|
|
|
|
" lw %1, 8(%2) \n"
|
|
" addu %0, $1 \n"
|
|
" addu %0, %1 \n"
|
|
" sltu $1, %0, %1 \n"
|
|
|
|
" lw %1, 12(%2) \n"
|
|
" addu %0, $1 \n"
|
|
" addu %0, %1 \n"
|
|
" sltu $1, %0, %1 \n"
|
|
|
|
" lw %1, 0(%3) \n"
|
|
" addu %0, $1 \n"
|
|
" addu %0, %1 \n"
|
|
" sltu $1, %0, %1 \n"
|
|
|
|
" lw %1, 4(%3) \n"
|
|
" addu %0, $1 \n"
|
|
" addu %0, %1 \n"
|
|
" sltu $1, %0, %1 \n"
|
|
|
|
" lw %1, 8(%3) \n"
|
|
" addu %0, $1 \n"
|
|
" addu %0, %1 \n"
|
|
" sltu $1, %0, %1 \n"
|
|
|
|
" lw %1, 12(%3) \n"
|
|
" addu %0, $1 \n"
|
|
" addu %0, %1 \n"
|
|
" sltu $1, %0, %1 \n"
|
|
|
|
" addu %0, $1 # Add final carry\n"
|
|
" .set pop"
|
|
: "=r" (sum), "=r" (proto)
|
|
: "r" (saddr), "r" (daddr),
|
|
"0" (htonl(len)), "1" (htonl(proto)), "r" (sum));
|
|
|
|
return csum_fold(sum);
|
|
}
|
|
|
|
#endif /* _ASM_CHECKSUM_H */
|