mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 18:14:07 +08:00
2c656491e9
Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
195 lines
4.8 KiB
C
195 lines
4.8 KiB
C
#ifndef _I386_CHECKSUM_H
|
|
#define _I386_CHECKSUM_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
|
|
*/
|
|
asmlinkage unsigned int csum_partial(const unsigned char * buff, int len, unsigned int 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
|
|
*/
|
|
|
|
asmlinkage unsigned int csum_partial_copy_generic(const unsigned char *src, unsigned char *dst,
|
|
int len, int sum, int *src_err_ptr, int *dst_err_ptr);
|
|
|
|
/*
|
|
* Note: when you get a NULL pointer exception here this means someone
|
|
* passed in an incorrect kernel address to one of these functions.
|
|
*
|
|
* If you use these functions directly please don't forget the
|
|
* access_ok().
|
|
*/
|
|
static __inline__
|
|
unsigned int csum_partial_copy_nocheck (const unsigned char *src, unsigned char *dst,
|
|
int len, int sum)
|
|
{
|
|
return csum_partial_copy_generic ( src, dst, len, sum, NULL, NULL);
|
|
}
|
|
|
|
static __inline__
|
|
unsigned int csum_partial_copy_from_user(const unsigned char __user *src, unsigned char *dst,
|
|
int len, int sum, int *err_ptr)
|
|
{
|
|
might_sleep();
|
|
return csum_partial_copy_generic((__force unsigned char *)src, dst,
|
|
len, sum, err_ptr, NULL);
|
|
}
|
|
|
|
/*
|
|
* 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 sum;
|
|
|
|
__asm__ __volatile__(
|
|
"movl (%1), %0 ;\n"
|
|
"subl $4, %2 ;\n"
|
|
"jbe 2f ;\n"
|
|
"addl 4(%1), %0 ;\n"
|
|
"adcl 8(%1), %0 ;\n"
|
|
"adcl 12(%1), %0 ;\n"
|
|
"1: adcl 16(%1), %0 ;\n"
|
|
"lea 4(%1), %1 ;\n"
|
|
"decl %2 ;\n"
|
|
"jne 1b ;\n"
|
|
"adcl $0, %0 ;\n"
|
|
"movl %0, %2 ;\n"
|
|
"shrl $16, %0 ;\n"
|
|
"addw %w2, %w0 ;\n"
|
|
"adcl $0, %0 ;\n"
|
|
"notl %0 ;\n"
|
|
"2: ;\n"
|
|
/* Since the input registers which are loaded with iph and ihl
|
|
are modified, we must also specify them as outputs, or gcc
|
|
will assume they contain their original values. */
|
|
: "=r" (sum), "=r" (iph), "=r" (ihl)
|
|
: "1" (iph), "2" (ihl)
|
|
: "memory");
|
|
return(sum);
|
|
}
|
|
|
|
/*
|
|
* Fold a partial checksum
|
|
*/
|
|
|
|
static inline unsigned int csum_fold(unsigned int sum)
|
|
{
|
|
__asm__(
|
|
"addl %1, %0 ;\n"
|
|
"adcl $0xffff, %0 ;\n"
|
|
: "=r" (sum)
|
|
: "r" (sum << 16), "0" (sum & 0xffff0000)
|
|
);
|
|
return (~sum) >> 16;
|
|
}
|
|
|
|
static inline unsigned long csum_tcpudp_nofold(unsigned long saddr,
|
|
unsigned long daddr,
|
|
unsigned short len,
|
|
unsigned short proto,
|
|
unsigned int sum)
|
|
{
|
|
__asm__(
|
|
"addl %1, %0 ;\n"
|
|
"adcl %2, %0 ;\n"
|
|
"adcl %3, %0 ;\n"
|
|
"adcl $0, %0 ;\n"
|
|
: "=r" (sum)
|
|
: "g" (daddr), "g"(saddr), "g"((ntohs(len)<<16)+proto*256), "0"(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__(
|
|
"addl 0(%1), %0 ;\n"
|
|
"adcl 4(%1), %0 ;\n"
|
|
"adcl 8(%1), %0 ;\n"
|
|
"adcl 12(%1), %0 ;\n"
|
|
"adcl 0(%2), %0 ;\n"
|
|
"adcl 4(%2), %0 ;\n"
|
|
"adcl 8(%2), %0 ;\n"
|
|
"adcl 12(%2), %0 ;\n"
|
|
"adcl %3, %0 ;\n"
|
|
"adcl %4, %0 ;\n"
|
|
"adcl $0, %0 ;\n"
|
|
: "=&r" (sum)
|
|
: "r" (saddr), "r" (daddr),
|
|
"r"(htonl(len)), "r"(htonl(proto)), "0"(sum));
|
|
|
|
return csum_fold(sum);
|
|
}
|
|
|
|
/*
|
|
* 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();
|
|
if (access_ok(VERIFY_WRITE, dst, len))
|
|
return csum_partial_copy_generic(src, (__force unsigned char *)dst, len, sum, NULL, err_ptr);
|
|
|
|
if (len)
|
|
*err_ptr = -EFAULT;
|
|
|
|
return -1; /* invalid checksum */
|
|
}
|
|
|
|
#endif
|