gatekeeper HAL service: add security policy

Change-Id: I79a305407c3a362d7be11f4c026f31f1e9666f1c
Signed-off-by: Alexey Polyudov <apolyudov@google.com>

private/file_contexts

@@ -233,6 +233,7 @@
 /system/bin/hw/android\.hardware\.boot@1\.0-service           u:object_r:hal_boot_exec:s0
 /system/bin/hw/android\.hardware\.contexthub@1\.0-service     u:object_r:hal_contexthub_default_exec:s0
 /system/bin/hw/android\.hardware\.dumpstate@1\.0-service      u:object_r:hal_dumpstate_default_exec:s0
+/system/bin/hw/android\.hardware\.gatekeeper@1\.0-service     u:object_r:hal_gatekeeper_default_exec:s0
 /system/bin/hw/android\.hardware\.graphics\.allocator@2\.0-service   u:object_r:hal_graphics_allocator_default_exec:s0
 /system/bin/hw/android\.hardware\.graphics\.composer@2\.1-service    u:object_r:hal_graphics_composer_default_exec:s0
 /system/bin/hw/android\.hardware\.health@1\.0-service         u:object_r:hal_health_default_exec:s0

private/hal_gatekeeper_default.te

+type hal_gatekeeper_default, hal_gatekeeper, domain;
+type hal_gatekeeper_default_exec, exec_type, file_type;
+
+init_daemon_domain(hal_gatekeeper_default);

public/attributes

@@ -117,6 +117,7 @@ attribute update_engine_common;
 # HALs
 attribute hal_audio;
 attribute hal_dumpstate;
+attribute hal_gatekeeper;
 attribute hal_graphics_allocator;
 attribute hal_graphics_composer;
 attribute hal_health;

public/gatekeeperd.te

-type gatekeeperd, domain;
+# normally uses HAL; implements HAL in pass-through mode only
+type gatekeeperd, hal_gatekeeper, domain;
 type gatekeeperd_exec, exec_type, file_type;
 
 # gatekeeperd
 binder_service(gatekeeperd)
 binder_use(gatekeeperd)
-allow gatekeeperd tee_device:chr_file rw_file_perms;
-allow gatekeeperd ion_device:chr_file r_file_perms;
 
 # need to find KeyStore and add self
 allow gatekeeperd gatekeeper_service:service_manager { add find };
@@ -20,6 +19,7 @@ allow gatekeeperd keystore:keystore_key { add_auth };
 # For permissions checking
 allow gatekeeperd system_server:binder call;
 allow gatekeeperd permission_service:service_manager find;
+
 # For parent user ID lookup
 allow gatekeeperd user_service:service_manager find;
 

public/hal_gatekeeper.te

+# hwbinder access
+hwbinder_use(hal_gatekeeper)
+
+# call into gatekeeperd process (callbacks)
+binder_call(hal_gatekeeper, gatekeeperd)
+
+# TEE access.
+allow hal_gatekeeper tee_device:chr_file rw_file_perms;
+allow hal_gatekeeper ion_device:chr_file r_file_perms;