Add microdroid specific sepolicy
Microdroid will have a separate sepolicy, apart from the core policy.
This is the first step; For now it's a simple copy of system/sepolicy.
For the future work, it will be stripped.
Bug: 189165759
Test: boot microdroid and see selinux enforced
Change-Id: I2fee39f7231560b49c93bd5e8d0feeffada40938
diff --git a/microdroid/sepolicy/system/public/runas.te b/microdroid/sepolicy/system/public/runas.te
new file mode 100644
index 0000000..356a019
--- /dev/null
+++ b/microdroid/sepolicy/system/public/runas.te
@@ -0,0 +1,43 @@
+type runas, domain, mlstrustedsubject;
+type runas_exec, system_file_type, exec_type, file_type;
+
+allow runas adbd:fd use;
+allow runas adbd:process sigchld;
+allow runas adbd:unix_stream_socket { read write };
+allow runas shell:fd use;
+allow runas shell:fifo_file { read write };
+allow runas shell:unix_stream_socket { read write };
+allow runas devpts:chr_file { read write ioctl };
+allow runas shell_data_file:file { read write };
+
+# run-as reads package information.
+allow runas system_data_file:file r_file_perms;
+allow runas system_data_file:lnk_file getattr;
+allow runas packages_list_file:file r_file_perms;
+
+# The app's data dir may be accessed through a symlink.
+allow runas system_data_file:lnk_file read;
+
+# run-as checks and changes to the app data dir.
+dontaudit runas self:global_capability_class_set { dac_override dac_read_search };
+allow runas app_data_file:dir { getattr search };
+
+# run-as switches to the app UID/GID.
+allow runas self:global_capability_class_set { setuid setgid };
+
+# run-as switches to the app security context.
+selinux_check_context(runas) # validate context
+allow runas self:process setcurrent;
+allow runas non_system_app_set:process dyntransition; # setcon
+
+# runas/libselinux needs access to seapp_contexts_file to
+# determine which domain to transition to.
+allow runas seapp_contexts_file:file r_file_perms;
+
+###
+### neverallow rules
+###
+
+# run-as cannot have capabilities other than CAP_SETUID and CAP_SETGID
+neverallow runas self:global_capability_class_set ~{ setuid setgid };
+neverallow runas self:global_capability2_class_set *;