commit ddc124b6759d414724700ad76085a6078b5b255b
author Shikha Panwar <shikhapanwar@google.com> Mon Nov 28 19:17:54 2022 +0000
committer Shikha Panwar <shikhapanwar@google.com> Wed Nov 30 11:55:22 2022 +0000
tree 8adb63006935e85cf5c3976644b9a6c97679d4e1
parent 3f6f6a55a2f1651b9b34df8a4057586b400c43e0

Implement native method getEncryptedStoragePath()

AVmPayload_getEncryptedStoragePath will return path to encrypted storage
if present, otherwise it will return NULL pointer.

The existence of ENCRYPTEDSTORE_MOUNTPOINT path is sufficient to
determine this. This is because Microdroid manager passes this path as
the mountpoint to encryptedstore & waits for it before starting
vm_payload_service.

Bug: 254454578
Test: build succeeds
Change-Id: Ifdfe1b97f08fc2e3f84ba1e49e6ca3e25e0013fc

vm_payload/src/api.rs

diff --git a/vm_payload/src/api.rs b/vm_payload/src/api.rs
index a79c0bb..28b440e 100644
--- a/vm_payload/src/api.rs
+++ b/vm_payload/src/api.rs
@@ -18,7 +18,7 @@
 #![warn(unsafe_op_in_unsafe_fn)]
 
 use android_system_virtualization_payload::aidl::android::system::virtualization::payload::IVmPayloadService::{
-    IVmPayloadService, VM_PAYLOAD_SERVICE_SOCKET_NAME, VM_APK_CONTENTS_PATH};
+    ENCRYPTEDSTORE_MOUNTPOINT, IVmPayloadService, VM_PAYLOAD_SERVICE_SOCKET_NAME, VM_APK_CONTENTS_PATH};
 use anyhow::{ensure, bail, Context, Result};
 use binder::{Strong, unstable_api::{AIBinder, new_spibinder}};
 use lazy_static::lazy_static;
@@ -28,6 +28,7 @@
 use std::ffi::CString;
 use std::fmt::Debug;
 use std::os::raw::{c_char, c_void};
+use std::path::Path;
 use std::ptr;
 use std::sync::{Mutex, atomic::{AtomicBool, Ordering}};
 
@@ -35,6 +36,8 @@
     static ref VM_APK_CONTENTS_PATH_C: CString =
         CString::new(VM_APK_CONTENTS_PATH).expect("CString::new failed");
     static ref PAYLOAD_CONNECTION: Mutex<Option<Strong<dyn IVmPayloadService>>> = Mutex::default();
+    static ref VM_ENCRYPTED_STORAGE_PATH_C: CString =
+        CString::new(ENCRYPTEDSTORE_MOUNTPOINT).expect("CString::new failed");
 }
 
 static ALREADY_NOTIFIED: AtomicBool = AtomicBool::new(false);
@@ -249,12 +252,15 @@
 /// Gets the path to the APK contents.
 #[no_mangle]
 pub extern "C" fn AVmPayload_getApkContentsPath() -> *const c_char {
-    (*VM_APK_CONTENTS_PATH_C).as_ptr()
+    VM_APK_CONTENTS_PATH_C.as_ptr()
 }
 
 /// Gets the path to the VM's encrypted storage.
 #[no_mangle]
 pub extern "C" fn AVmPayload_getEncryptedStoragePath() -> *const c_char {
-    // TODO(b/254454578): Return a real path if storage is present
-    ptr::null()
+    if Path::new(ENCRYPTEDSTORE_MOUNTPOINT).exists() {
+        VM_ENCRYPTED_STORAGE_PATH_C.as_ptr()
+    } else {
+        ptr::null()
+    }
 }