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@@ -1,6 +1,150 @@
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#ifndef __UM_CHECKSUM_H
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#define __UM_CHECKSUM_H
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+#include <linux/string.h>
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+#include <linux/in6.h>
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+
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+/*
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+ * computes the checksum of a memory block at buff, length len,
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+ * and adds in "sum" (32-bit)
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+ *
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+ * returns a 32-bit number suitable for feeding into itself
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+ * or csum_tcpudp_magic
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+ *
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+ * this function must be called with even lengths, except
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+ * for the last fragment, which may be odd
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+ *
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+ * it's best to have buff aligned on a 32-bit boundary
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+ */
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+extern __wsum csum_partial(const void *buff, int len, __wsum sum);
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+
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+/*
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+ * Note: when you get a NULL pointer exception here this means someone
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+ * passed in an incorrect kernel address to one of these functions.
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+ *
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+ * If you use these functions directly please don't forget the
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+ * access_ok().
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+ */
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+
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+static __inline__
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+__wsum csum_partial_copy_nocheck(const void *src, void *dst,
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+ int len, __wsum sum)
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+{
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+ memcpy(dst, src, len);
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+ return csum_partial(dst, len, sum);
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+}
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+
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+/*
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+ * the same as csum_partial, but copies from src while it
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+ * checksums, and handles user-space pointer exceptions correctly, when needed.
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+ *
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+ * here even more important to align src and dst on a 32-bit (or even
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+ * better 64-bit) boundary
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+ */
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+
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+static __inline__
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+__wsum csum_partial_copy_from_user(const void __user *src, void *dst,
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+ int len, __wsum sum, int *err_ptr)
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+{
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+ if (copy_from_user(dst, src, len)) {
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+ *err_ptr = -EFAULT;
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+ return (__force __wsum)-1;
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+ }
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+
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+ return csum_partial(dst, len, sum);
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+}
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+
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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__(
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+ " 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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+ );
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+ return (__force __sum16)(~(__force u32)sum >> 16);
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+}
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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), "g" ((len + proto) << 8), "0" (sum));
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+ return sum;
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+}
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+
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+/*
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+ * computes the checksum of the TCP/UDP pseudo-header
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+ * returns a 16-bit checksum, already complemented
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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,
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+ __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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+/**
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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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+
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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 ipl
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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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#ifdef CONFIG_X86_32
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# include "checksum_32.h"
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#else
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Al Viro