Also includes a few fixes for IPv4 multicast support. IPv6 support is coming in
a followup CL.
PiperOrigin-RevId: 233008638
Change-Id: If7dae6222fef43fda48033f0292af77832d95e82
Previously, dual stack UDP sockets bound to an IPv4 address could not use
sendto to communicate with IPv4 addresses. Further, dual stack UDP sockets
bound to an IPv6 address could use sendto to communicate with IPv4 addresses.
Neither of these behaviors are consistent with Linux.
PiperOrigin-RevId: 197036024
Change-Id: Ic3713efc569f26196e35bb41e6ad63f23675fc90