Introduce support for Mandatory Access Control and extensible

kernel access control.

When decompressing data from one mbuf into another mbuf, preserve the
mbuf label by copying it to the new mbuf.

Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, NAI Labs

sys/net/bsd_comp.c

@@ -43,9 +43,12 @@
  * $FreeBSD$
  */
 
+#include "opt_mac.h"
+
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/lock.h>
+#include <sys/mac.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
 #include <sys/mutex.h>
@@ -879,6 +882,9 @@ bsd_decompress(state, cmp, dmpp)
     dmp->m_data += db->hdrlen;
     wptr = mtod(dmp, u_char *);
     space = M_TRAILINGSPACE(dmp) - PPP_HDRLEN + 1;
+#ifdef MAC
+    mac_create_mbuf_from_mbuf(cmp, dmp);
+#endif
 
     /*
      * Fill in the ppp header, but not the last byte of the protocol