Split gsi_metadata_file and add gsi_metadata_file_type attribute

Split gsi_metadata_file into gsi_metadata_file plus
gsi_public_metadata_file, and add gsi_metadata_file_type attribute.
Files that are okay to be publicly readable are labeled with
gsi_public_metadata_file. Right now only files needed to infer the
device fstab belong to this label.
The difference between gsi_metadata_file and gsi_public_metadata_file is
that gsi_public_metadata_file has relaxed neverallow rules, so processes
who wish to read the fstab can add the respective allow rules to their
policy files.
Allow gsid to restorecon on gsi_metadata_file to fix the file context of
gsi_public_metadata_file.

Bug: 181110285
Test: Build pass
Test: Issue a DSU installation then verify no DSU related denials and
  files under /metadata/gsi/ are labeled correctly.
Change-Id: I54a5fe734dd345e28fd8c0874d5fceaf80ab8c11
diff --git a/private/compat/28.0/28.0.ignore.cil b/private/compat/28.0/28.0.ignore.cil
index d24d12d..e7ddf48 100644
--- a/private/compat/28.0/28.0.ignore.cil
+++ b/private/compat/28.0/28.0.ignore.cil
@@ -61,6 +61,7 @@
     gpuservice
     gsi_data_file
     gsi_metadata_file
+    gsi_public_metadata_file
     gsi_service
     gsid
     gsid_exec
diff --git a/private/compat/30.0/30.0.cil b/private/compat/30.0/30.0.cil
index 73374e6..2b2b04a 100644
--- a/private/compat/30.0/30.0.cil
+++ b/private/compat/30.0/30.0.cil
@@ -1482,7 +1482,9 @@
 (typeattributeset graphics_device_30_0 (graphics_device))
 (typeattributeset graphicsstats_service_30_0 (graphicsstats_service))
 (typeattributeset gsi_data_file_30_0 (gsi_data_file))
-(typeattributeset gsi_metadata_file_30_0 (gsi_metadata_file))
+(typeattributeset gsi_metadata_file_30_0
+  ( gsi_metadata_file
+    gsi_public_metadata_file))
 (typeattributeset gsid_prop_30_0 (gsid_prop))
 (typeattributeset hal_atrace_hwservice_30_0 (hal_atrace_hwservice))
 (typeattributeset hal_audio_hwservice_30_0 (hal_audio_hwservice))
diff --git a/private/file_contexts b/private/file_contexts
index 1347797..d5d773c 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -762,6 +762,10 @@
 /metadata/apex(/.*)?      u:object_r:apex_metadata_file:s0
 /metadata/vold(/.*)?      u:object_r:vold_metadata_file:s0
 /metadata/gsi(/.*)?       u:object_r:gsi_metadata_file:s0
+/metadata/gsi/dsu/active  u:object_r:gsi_public_metadata_file:s0
+/metadata/gsi/dsu/booted  u:object_r:gsi_public_metadata_file:s0
+/metadata/gsi/dsu/lp_names  u:object_r:gsi_public_metadata_file:s0
+/metadata/gsi/dsu/[^/]+/metadata_encryption_dir u:object_r:gsi_public_metadata_file:s0
 /metadata/gsi/ota(/.*)?   u:object_r:ota_metadata_file:s0
 /metadata/password_slots(/.*)?    u:object_r:password_slot_metadata_file:s0
 /metadata/ota(/.*)?       u:object_r:ota_metadata_file:s0
diff --git a/private/gsid.te b/private/gsid.te
index c523731..fb40528 100644
--- a/private/gsid.te
+++ b/private/gsid.te
@@ -123,7 +123,7 @@
 #
 allow gsid metadata_file:dir { search getattr };
 allow gsid {
-    gsi_metadata_file
+    gsi_metadata_file_type
 }:dir create_dir_perms;
 
 allow gsid {
@@ -131,10 +131,15 @@
 }:dir rw_dir_perms;
 
 allow gsid {
-    gsi_metadata_file
+    gsi_metadata_file_type
     ota_metadata_file
 }:file create_file_perms;
 
+# Allow restorecon to fix context of gsi_public_metadata_file.
+allow gsid file_contexts_file:file r_file_perms;
+allow gsid gsi_metadata_file:file relabelfrom;
+allow gsid gsi_public_metadata_file:file relabelto;
+
 allow gsid {
       gsi_data_file
       ota_image_data_file
@@ -153,6 +158,9 @@
 
 allow gsid system_server:binder call;
 
+# Prevent most processes from writing to gsi_metadata_file_type, but allow
+# adding rules for path resolution of gsi_public_metadata_file and reading
+# gsi_public_metadata_file.
 neverallow {
     domain
     -init
@@ -160,7 +168,7 @@
     -fastbootd
     -recovery
     -vold
-} gsi_metadata_file:dir *;
+} gsi_metadata_file_type:dir no_w_dir_perms;
 
 neverallow {
     domain
@@ -168,7 +176,18 @@
     -gsid
     -fastbootd
     -vold
-} gsi_metadata_file:file_class_set *;
+} { gsi_metadata_file_type -gsi_public_metadata_file }:file_class_set *;
+
+neverallow {
+    domain
+    -init
+    -gsid
+    -fastbootd
+    -vold
+} gsi_public_metadata_file:file_class_set ~{ r_file_perms };
+
+# Prevent apps from accessing gsi_metadata_file_type.
+neverallow appdomain gsi_metadata_file_type:dir_file_class_set *;
 
 neverallow {
     domain
diff --git a/private/lpdumpd.te b/private/lpdumpd.te
index 3bcd761..a264be7 100644
--- a/private/lpdumpd.te
+++ b/private/lpdumpd.te
@@ -20,8 +20,8 @@
 # Triggered when lpdumpd tries to read default fstab.
 dontaudit lpdumpd metadata_file:dir r_dir_perms;
 dontaudit lpdumpd metadata_file:file r_file_perms;
-dontaudit lpdumpd gsi_metadata_file:dir r_dir_perms;
-dontaudit lpdumpd gsi_metadata_file:file r_file_perms;
+dontaudit lpdumpd gsi_metadata_file_type:dir r_dir_perms;
+dontaudit lpdumpd gsi_metadata_file_type:file r_file_perms;
 
 ### Neverallow rules