Linux supports many obsolete address families, which are usually available in
common distro kernels, but they are less likely to be properly audited and
may have security issues
This blocks all socket families in the socket (and socketcall where applicable) syscall
except
- AF_UNIX - Unix domain sockets
- AF_INET - IPv4
- AF_INET6 - IPv6
- AF_NETLINK - Netlink sockets for communicating with the ekrnel
- AF_PACKET - raw sockets, which are only allowed with CAP_NET_RAW
All other socket families are blocked, including Appletalk (native, not
over IP), IPX (remember that!), VSOCK and HVSOCK, which should not generally
be used in containers, etc.
Note that users can of course provide a profile per container or in the daemon
config if they have unusual use cases that require these.
Signed-off-by: Justin Cormack <justin.cormack@docker.com>
