Introduce two related changes to the TrustedBSD MAC Framework:

(1) Abstract interpreter vnode labeling in execve(2) and mac_execve(2)
    so that the general exec code isn't aware of the details of
    allocating, copying, and freeing labels, rather, simply passes in
    a void pointer to start and stop functions that will be used by
    the framework.  This change will be MFC'd.

(2) Introduce a new flags field to the MAC_POLICY_SET(9) interface
    allowing policies to declare which types of objects require label
    allocation, initialization, and destruction, and define a set of
    flags covering various supported object types (MPC_OBJECT_PROC,
    MPC_OBJECT_VNODE, MPC_OBJECT_INPCB, ...).  This change reduces the
    overhead of compiling the MAC Framework into the kernel if policies
    aren't loaded, or if policies require labels on only a small number
    or even no object types.  Each time a policy is loaded or unloaded,
    we recalculate a mask of labeled object types across all policies
    present in the system.  Eliminate MAC_ALWAYS_LABEL_MBUF option as it
    is no longer required.

MFC after:	1 week ((1) only)
Reviewed by:	csjp
Obtained from:	TrustedBSD Project
Sponsored by:	Apple, Inc.

1 files changed, 21 insertions, 1 deletions

diff --git a/sys/security/mac_mls/mac_mls.c b/sys/security/mac_mls/mac_mls.c
index c3b2cdaa6bd0..597628fb8cb6 100644
--- a/sys/security/mac_mls/mac_mls.c
+++ b/sys/security/mac_mls/mac_mls.c
@@ -3091,5 +3091,25 @@ static struct mac_policy_ops mls_ops =
 	.mpo_vnode_setlabel_extattr = mls_vnode_setlabel_extattr,
 };
 
+#define	MLS_OBJECTS	(MPC_OBJECT_CRED |				\
+			 /* MPC_OBJECT_PROC | */			\
+			 MPC_OBJECT_VNODE |				\
+			 MPC_OBJECT_INPCB |				\
+			 MPC_OBJECT_SOCKET |				\
+			 MPC_OBJECT_DEVFS |				\
+			 MPC_OBJECT_MBUF |				\
+			 MPC_OBJECT_IPQ |				\
+			 MPC_OBJECT_IFNET |				\
+			 MPC_OBJECT_BPFDESC |				\
+			 MPC_OBJECT_PIPE |				\
+			 MPC_OBJECT_MOUNT |				\
+			 MPC_OBJECT_POSIXSEM |				\
+			 /* MPC_OBJECT_POSIXSHM | */			\
+			 MPC_OBJECT_SYSVMSG |				\
+			 MPC_OBJECT_SYSVMSQ |				\
+			 MPC_OBJECT_SYSVSEM |				\
+			 MPC_OBJECT_SYSVSHM |				\
+			 MPC_OBJECT_SYNCACHE)
+
 MAC_POLICY_SET(&mls_ops, mac_mls, "TrustedBSD MAC/MLS",
-    MPC_LOADTIME_FLAG_NOTLATE | MPC_LOADTIME_FLAG_LABELMBUFS, &mls_slot);
+    MPC_LOADTIME_FLAG_NOTLATE, &mls_slot, MLS_OBJECTS);