checksum_32.h

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/*
 * Licensed under the GPL
 */

#ifndef __UM_SYSDEP_CHECKSUM_H
#define __UM_SYSDEP_CHECKSUM_H

static inline __sum16 ip_compute_csum(const void *buff, int len)
{
    return csum_fold (csum_partial(buff, len, 0));
}

#define _HAVE_ARCH_IPV6_CSUM
static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
                      const struct in6_addr *daddr,
                      __u32 len, unsigned short proto,
                      __wsum 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__ __wsum csum_and_copy_to_user(const void *src,
                             void __user *dst,
                             int len, __wsum sum, int *err_ptr)
{
    if (access_ok(VERIFY_WRITE, dst, len)) {
        if (copy_to_user(dst, src, len)) {
            *err_ptr = -EFAULT;
            return (__force __wsum)-1;
        }

        return csum_partial(src, len, sum);
    }

    if (len)
        *err_ptr = -EFAULT;

    return (__force __wsum)-1; /* invalid checksum */
}

#endif