In a couple of recent reports, we've seen that it
can be useful for pasta
to forward ports from addresses which are not currently configured on the
host, but might be in future. That can be done with the sysctl
net.ipv4.ip_nonlocal_bind, but that does require CAP_NET_ADMIN to set in
the first place. We can allow the same thing on a per-socket basis with
the IP_FREEBIND (or IPV6_FREEBIND) socket option.
Add a --freebind command line argument to enable this socket option on
all listening sockets.
Link:
https://bugs.passt.top/show_bug.cgi?id=101
Signed-off-by: David Gibson <david(a)gibson.dropbear.id.au>