tree e4dc84d2f6225a95af091b45ed63a4bce1ee723c
parent ff089ad94c37bd865769a93cb86889d8d85cda10
author Paul Marks <pmarks@google.com> 1449028457 -0800
committer Paul Marks <pmarks@google.com> 1449028457 -0800

Use both IPv4+IPv6 sockets to check whether a port is free.

This allows the portpicker to function in dual-stack and IPv4/IPv6-only
environments.

For a port to be considered available, the kernel must support at least
one of (IPv6, IPv4), and the port must be available on each supported
family.

Use identical/redundant implementations of bind() and is_port_free()
between portpicker and portserver.  I am assuming that these were
intentionally designed as self-contained programs, instead of sharing a
common library.