NAME
oneC_sum - One's complement internet checksum
SYNOPSIS
#define _MINIX_SOURCE 1
#include <stddef.h>
#include <sys/types.h>
#include <net/gen/oneCsum.h>
u16_t oneC_sum(u16_t prev, void *data, size_t size)
DESCRIPTION
OneC_sum is used to calculate the one's complement checksum
needed for IP network packets. A good document about the
Internet Checksum is RFC-1071 (Computing the Internet check-
sum).
OneC_sum expects three parameters:
prev The checksum of previous blocks of data that are
to be included in the checksum. The value of prev
in first call to oneC_sum should be 0.
data A pointer to the block of data. The data is
interpreted as a series of 16 bit numbers in net-
work byte order, but an odd number of bytes is
also allowed.
size The size of the data in bytes.
SEE ALSO
ip(4).
RFC-1071
AUTHOR
Philip Homburg (philip@cs.vu.nl)