static __wsum __csum_and_copy()

in lib/csum_partial_copy.c [316:347]

• 31 lines of code
• 4 McCabe index (conditional complexity)

static __wsum __csum_and_copy(const void __user *src, void *dst, int len)
{
	unsigned long soff = 7 & (unsigned long) src;
	unsigned long doff = 7 & (unsigned long) dst;
	unsigned long checksum;

	if (!doff) {
		if (!soff)
			checksum = csum_partial_cfu_aligned(
				(const unsigned long __user *) src,
				(unsigned long *) dst, len-8);
		else
			checksum = csum_partial_cfu_dest_aligned(
				(const unsigned long __user *) src,
				(unsigned long *) dst,
				soff, len-8);
	} else {
		unsigned long partial_dest;
		ldq_u(partial_dest, dst);
		if (!soff)
			checksum = csum_partial_cfu_src_aligned(
				(const unsigned long __user *) src,
				(unsigned long *) dst,
				doff, len-8, partial_dest);
		else
			checksum = csum_partial_cfu_unaligned(
				(const unsigned long __user *) src,
				(unsigned long *) dst,
				soff, doff, len-8, partial_dest);
	}
	return (__force __wsum)from64to16 (checksum);
}