From: Sakari Kapanen <sakari.kapanen@optofidelity.com>
Date: Sun, 24 Sep 2017 13:19:25 +0300
Subject: [PATCH] ICMPv6: fix router advertisement
Fixes several errors preventing icmpv6_radvertise.c from being compiled. Fixes conversions to network byte order (namely vlifetime, plifetime, mtu).
IPv6 source address is set to link-local IP address instead of the address in the netdev structure. This is in compliance to RFC 4861. RA didn't work on Linux before this change.
Finally, router prefix and prefix length are derived from the IPv6 address and netmask in the netdev structure. This seems to make more sense than using a predefined, separate prefix from the config.