Ah so it means "filter the source IP/port when receiving early packets on the connected socket" is done by recvfrom()? I was misunderstood that it is done by so

Ah so it means "filter the source IP/port when receiving early packets on the connected socket" is done by recvfrom()? I was misunderstood that it is done by some fancy iptable/epbf rule :) Thanks for clarification.