Failed ASM/SSM IGMP join if interface has no address

[troglobit]

The struct ip_mreq API with socket opt IP_ADD_MEMBERSHIP requires a valid IP address for the interface on which to perform the join.

A newer API using the Linux (and FreeBSD) specific struct ip_mreqn support IP_ADD_MEMBERSHIP using an ifindex instead. This API is however limited to IPv4.

RFC3678 define a complete new ASM/SSM API for both IPv4 and IPv6 using struct group_req which would better suit SMCRoute.

This bug report is filed with the intention of replacing at least the current IPv4 implementation with the RFC3678 API.