licensing and lib/tool/checksum.c

[Miika Komu]

For unified MIT-based code licensing, lib/tool/checksum.c has to be rewritten. This is my suggestion on how to proceed with rewriting this piece of code, feel free to comment.

ipv4_checksum() and ipv6_checksum() can be replaced with the following BSD-licensed code:

http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet/in_cksum.c?rev=1.10.10.1.4.1;content-type=text%2Fplain
http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet6/in6_cksum.c?rev=1.19;content-type=text%2Fplain

We need to include some header definitions and align the code with our code conventions as described in doc/HACKING. The FreeBSD code can be retrieved e.g. as follows:

svn co http://svn.freebsd.org/base/head/

I believe we can keep checksum_ip() which is from RFC 1071 section 4.1.

hip_checksum_packet() has to be rewritten from scratch because it was borrowed from OpenHIP which is based on GPL.

[René Hummen (rene-hummen)]

When rewriting the code, make sure to resolve bug #682745 (https://bugs.launchpad.net/hipl/+bug/682745) as well.

[Miika Komu (miika-iki)]

hip_checksum_packet() could be rewritten with checksum_ip and ipv6_checksum.