scripts/selinux,selinux: update mdp to enable policy capabilities

Presently mdp does not enable any SELinux policy capabilities
in the dummy policy it generates. Thus, policies derived from
it will by default lack various features commonly used in modern
policies such as open permission, extended socket classes, network
peer controls, etc.  Split the policy capability definitions out into
their own headers so that we can include them into mdp without pulling in
other kernel headers and extend mdp generate policycap statements for the
policy capabilities known to the kernel.  Policy authors may wish to
selectively remove some of these from the generated policy.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Author: stephensmalley

scripts/selinux/mdp/mdp.c

@@ -35,6 +35,9 @@ struct security_class_mapping {
 
 #include "classmap.h"
 #include "initial_sid_to_string.h"
+#include "policycap_names.h"
+
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
 
 int main(int argc, char *argv[])
 {
@@ -115,6 +118,10 @@ int main(int argc, char *argv[])
 		}
 	}
 
+	/* enable all policy capabilities */
+	for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++)
+		fprintf(fout, "policycap %s;\n", selinux_policycap_names[i]);
+
 	/* types, roles, and allows */
 	fprintf(fout, "type base_t;\n");
 	fprintf(fout, "role base_r;\n");

security/selinux/include/policycap.h

@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SELINUX_POLICYCAP_H_
+#define _SELINUX_POLICYCAP_H_
+
+/* Policy capabilities */
+enum {
+	POLICYDB_CAPABILITY_NETPEER,
+	POLICYDB_CAPABILITY_OPENPERM,
+	POLICYDB_CAPABILITY_EXTSOCKCLASS,
+	POLICYDB_CAPABILITY_ALWAYSNETWORK,
+	POLICYDB_CAPABILITY_CGROUPSECLABEL,
+	POLICYDB_CAPABILITY_NNP_NOSUID_TRANSITION,
+	POLICYDB_CAPABILITY_GENFS_SECLABEL_SYMLINKS,
+	__POLICYDB_CAPABILITY_MAX
+};
+#define POLICYDB_CAPABILITY_MAX (__POLICYDB_CAPABILITY_MAX - 1)
+
+extern const char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX];
+
+#endif /* _SELINUX_POLICYCAP_H_ */

security/selinux/include/policycap_names.h

@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SELINUX_POLICYCAP_NAMES_H_
+#define _SELINUX_POLICYCAP_NAMES_H_
+
+#include "policycap.h"
+
+/* Policy capability names */
+const char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX] = {
+	"network_peer_controls",
+	"open_perms",
+	"extended_socket_class",
+	"always_check_network",
+	"cgroup_seclabel",
+	"nnp_nosuid_transition",
+	"genfs_seclabel_symlinks"
+};
+
+#endif /* _SELINUX_POLICYCAP_NAMES_H_ */

security/selinux/include/security.h

@@ -16,6 +16,7 @@
 #include <linux/refcount.h>
 #include <linux/workqueue.h>
 #include "flask.h"
+#include "policycap.h"
 
 #define SECSID_NULL			0x00000000 /* unspecified SID */
 #define SECSID_WILD			0xffffffff /* wildcard SID */
@@ -72,21 +73,6 @@ struct netlbl_lsm_secattr;
 
 extern int selinux_enabled_boot;
 
-/* Policy capabilities */
-enum {
-	POLICYDB_CAPABILITY_NETPEER,
-	POLICYDB_CAPABILITY_OPENPERM,
-	POLICYDB_CAPABILITY_EXTSOCKCLASS,
-	POLICYDB_CAPABILITY_ALWAYSNETWORK,
-	POLICYDB_CAPABILITY_CGROUPSECLABEL,
-	POLICYDB_CAPABILITY_NNP_NOSUID_TRANSITION,
-	POLICYDB_CAPABILITY_GENFS_SECLABEL_SYMLINKS,
-	__POLICYDB_CAPABILITY_MAX
-};
-#define POLICYDB_CAPABILITY_MAX (__POLICYDB_CAPABILITY_MAX - 1)
-
-extern const char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX];
-
 /*
  * type_datum properties
  * available at the kernel policy version >= POLICYDB_VERSION_BOUNDARY

security/selinux/ss/services.c

@@ -64,17 +64,7 @@
 #include "xfrm.h"
 #include "ebitmap.h"
 #include "audit.h"
-
-/* Policy capability names */
-const char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX] = {
-	"network_peer_controls",
-	"open_perms",
-	"extended_socket_class",
-	"always_check_network",
-	"cgroup_seclabel",
-	"nnp_nosuid_transition",
-	"genfs_seclabel_symlinks"
-};
+#include "policycap_names.h"
 
 static struct selinux_ss selinux_ss;