passt usually doesn't NAT, but it does do so for the remapping of the
gateway address to refer to the host. Currently we perform this NAT with
slightly different rules on both IPv4 addresses and IPv6 addresses, but not
on IPv4-mapped IPv6 addresses. This means we won't correctly handle the
case of an IPv4 connection over an IPv6 socket, which is possible on Linux
(and probably other platforms).
Refactor tcp_conn_from_sock() to perform the NAT after converting either
address family into an inany_addr, so IPv4 and and IPv4-mapped addresses
have the same representation.
With two new helpers this lets us remove the IPv4 and IPv6 specific paths
from tcp_conn_from_sock().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
struct tcp_conn stores an address which could be IPv6 or IPv4 using a
union. We can do this without an additional tag by encoding IPv4 addresses
as IPv4-mapped IPv6 addresses.
This approach is useful wider than the specific place in tcp_conn, so
expose a new 'union inany_addr' like this from a new inany.h. Along with
that create a number of helper functions to make working with these "inany"
addresses easier.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
