[SELinux]: Add support for DCCP

This patch implements SELinux kernel support for DCCP
(http://linux-net.osdl.org/index.php/DCCP), which is similar in
operation to TCP in terms of connected state between peers.

The SELinux support for DCCP is thus modeled on existing handling of
TCP.

A new DCCP socket class is introduced, to allow protocol
differentation.  The permissions for this class inherit all of the
socket permissions, as well as the current TCP permissions (node_bind,
name_bind etc). IPv4 and IPv6 are supported, although labeled
networking is not, at this stage.

Patches for SELinux userspace are at:
http://people.redhat.com/jmorris/selinux/dccp/user/

I've performed some basic testing, and it seems to be working as
expected.  Adding policy support is similar to TCP, the only real
difference being that it's a different protocol.

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/security/selinux/include/av_inherit.h b/security/selinux/include/av_inherit.h
index a68fdd5..8377a4b 100644
--- a/security/selinux/include/av_inherit.h
+++ b/security/selinux/include/av_inherit.h
@@ -30,3 +30,4 @@
    S_(SECCLASS_NETLINK_DNRT_SOCKET, socket, 0x00400000UL)
    S_(SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET, socket, 0x00400000UL)
    S_(SECCLASS_APPLETALK_SOCKET, socket, 0x00400000UL)
+   S_(SECCLASS_DCCP_SOCKET, socket, 0x00400000UL)