192 lines
5.2 KiB
C
192 lines
5.2 KiB
C
#ifndef _X86_64_CHECKSUM_H
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#define _X86_64_CHECKSUM_H
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/*
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* Checksums for x86-64
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* Copyright 2002 by Andi Kleen, SuSE Labs
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* with some code from asm-x86/checksum.h
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*/
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#include <linux/compiler.h>
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#include <asm/uaccess.h>
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#include <asm/byteorder.h>
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/**
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* csum_fold - Fold and invert a 32bit checksum.
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* sum: 32bit unfolded sum
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*
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* Fold a 32bit running checksum to 16bit and invert it. This is usually
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* the last step before putting a checksum into a packet.
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* Make sure not to mix with 64bit checksums.
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*/
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static inline __sum16 csum_fold(__wsum sum)
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{
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asm(" addl %1,%0\n"
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" adcl $0xffff,%0"
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: "=r" (sum)
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: "r" ((__force u32)sum << 16),
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"0" ((__force u32)sum & 0xffff0000));
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return (__force __sum16)(~(__force u32)sum >> 16);
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}
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/*
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* This is a version of ip_compute_csum() optimized for IP headers,
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* which always checksum on 4 octet boundaries.
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*
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* By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
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* Arnt Gulbrandsen.
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*/
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/**
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* ip_fast_csum - Compute the IPv4 header checksum efficiently.
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* iph: ipv4 header
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* ihl: length of header / 4
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*/
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static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
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{
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unsigned int sum;
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asm(" movl (%1), %0\n"
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" subl $4, %2\n"
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" jbe 2f\n"
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" addl 4(%1), %0\n"
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" adcl 8(%1), %0\n"
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" adcl 12(%1), %0\n"
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"1: adcl 16(%1), %0\n"
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" lea 4(%1), %1\n"
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" decl %2\n"
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" jne 1b\n"
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" adcl $0, %0\n"
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" movl %0, %2\n"
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" shrl $16, %0\n"
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" addw %w2, %w0\n"
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" adcl $0, %0\n"
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" notl %0\n"
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"2:"
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/* Since the input registers which are loaded with iph and ihl
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are modified, we must also specify them as outputs, or gcc
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will assume they contain their original values. */
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: "=r" (sum), "=r" (iph), "=r" (ihl)
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: "1" (iph), "2" (ihl)
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: "memory");
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return (__force __sum16)sum;
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}
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/**
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* csum_tcpup_nofold - Compute an IPv4 pseudo header checksum.
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* @saddr: source address
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* @daddr: destination address
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* @len: length of packet
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* @proto: ip protocol of packet
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* @sum: initial sum to be added in (32bit unfolded)
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*
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* Returns the pseudo header checksum the input data. Result is
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* 32bit unfolded.
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*/
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static inline __wsum
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csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
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unsigned short proto, __wsum sum)
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{
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asm(" addl %1, %0\n"
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" adcl %2, %0\n"
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" adcl %3, %0\n"
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" adcl $0, %0\n"
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: "=r" (sum)
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: "g" (daddr), "g" (saddr),
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"g" ((len + proto)<<8), "0" (sum));
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return sum;
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}
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/**
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* csum_tcpup_magic - Compute an IPv4 pseudo header checksum.
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* @saddr: source address
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* @daddr: destination address
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* @len: length of packet
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* @proto: ip protocol of packet
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* @sum: initial sum to be added in (32bit unfolded)
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*
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* Returns the 16bit pseudo header checksum the input data already
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* complemented and ready to be filled in.
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*/
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static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
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unsigned short len,
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unsigned short proto, __wsum sum)
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{
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return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
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}
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/**
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* csum_partial - Compute an internet checksum.
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* @buff: buffer to be checksummed
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* @len: length of buffer.
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* @sum: initial sum to be added in (32bit unfolded)
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*
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* Returns the 32bit unfolded internet checksum of the buffer.
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* Before filling it in it needs to be csum_fold()'ed.
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* buff should be aligned to a 64bit boundary if possible.
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*/
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extern __wsum csum_partial(const void *buff, int len, __wsum sum);
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#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1
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#define HAVE_CSUM_COPY_USER 1
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/* Do not call this directly. Use the wrappers below */
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extern __wsum csum_partial_copy_generic(const void *src, const void *dst,
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int len, __wsum sum,
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int *src_err_ptr, int *dst_err_ptr);
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extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
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int len, __wsum isum, int *errp);
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extern __wsum csum_partial_copy_to_user(const void *src, void __user *dst,
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int len, __wsum isum, int *errp);
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extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
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int len, __wsum sum);
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/* Old names. To be removed. */
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#define csum_and_copy_to_user csum_partial_copy_to_user
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#define csum_and_copy_from_user csum_partial_copy_from_user
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/**
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* ip_compute_csum - Compute an 16bit IP checksum.
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* @buff: buffer address.
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* @len: length of buffer.
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*
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* Returns the 16bit folded/inverted checksum of the passed buffer.
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* Ready to fill in.
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*/
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extern __sum16 ip_compute_csum(const void *buff, int len);
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/**
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* csum_ipv6_magic - Compute checksum of an IPv6 pseudo header.
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* @saddr: source address
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* @daddr: destination address
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* @len: length of packet
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* @proto: protocol of packet
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* @sum: initial sum (32bit unfolded) to be added in
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*
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* Computes an IPv6 pseudo header checksum. This sum is added the checksum
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* into UDP/TCP packets and contains some link layer information.
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* Returns the unfolded 32bit checksum.
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*/
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struct in6_addr;
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#define _HAVE_ARCH_IPV6_CSUM 1
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extern __sum16
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csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
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__u32 len, unsigned short proto, __wsum sum);
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static inline unsigned add32_with_carry(unsigned a, unsigned b)
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{
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asm("addl %2,%0\n\t"
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"adcl $0,%0"
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: "=r" (a)
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: "0" (a), "r" (b));
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return a;
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}
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#endif
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