SELinux: Add a network node caching mechanism similar to the sel_netif_*() functions

This patch adds a SELinux IP address/node SID caching mechanism similar to the
sel_netif_*() functions.  The node SID queries in the SELinux hooks files are
also modified to take advantage of this new functionality.  In addition, remove
the address length information from the sk_buff parsing routines as it is
redundant since we already have the address family.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/selinux/Makefile b/security/selinux/Makefile
index dc3502e..00afd85 100644
--- a/security/selinux/Makefile
+++ b/security/selinux/Makefile
@@ -4,7 +4,14 @@
 
 obj-$(CONFIG_SECURITY_SELINUX) := selinux.o ss/
 
-selinux-y := avc.o hooks.o selinuxfs.o netlink.o nlmsgtab.o netif.o exports.o
+selinux-y := avc.o \
+	     hooks.o \
+	     selinuxfs.o \
+	     netlink.o \
+	     nlmsgtab.o \
+	     netif.o \
+	     netnode.o \
+	     exports.o
 
 selinux-$(CONFIG_SECURITY_NETWORK_XFRM) += xfrm.o