[refactor] Split watchdog in a standalone library for reuse

This simplifies the task of creating an independent library of
rkpd_client later.

Test: atest keystore2_test
Bug: 241428146
Change-Id: I2834c9be9f5100d52829e6392f0dd48e7c76beb1

keystore2/Android.bp

@@ -61,6 +61,7 @@ rust_defaults {
         "libserde_cbor",
         "libthiserror",
         "libtokio",
+        "libwatchdog_rs",
     ],
     shared_libs: [
         "libcutils",

keystore2/TEST_MAPPING

@@ -33,6 +33,9 @@
     },
     {
       "name": "keystore2_client_tests"
+    },
+    {
+      "name": "libwatchdog_rs.test"
     }
   ]
 }

keystore2/src/lib.rs

@@ -50,6 +50,4 @@ mod gc;
 mod km_compat;
 mod super_key;
 mod sw_keyblob;
-
-#[cfg(feature = "watchdog")]
-mod watchdog;
+mod watchdog_helper;

keystore2/src/rkpd_client.rs

@@ -17,7 +17,7 @@
 use crate::error::{map_binder_status_code, Error, ResponseCode};
 use crate::globals::get_remotely_provisioned_component_name;
 use crate::ks_err;
-use crate::utils::watchdog as wd;
+use crate::watchdog_helper::watchdog as wd;
 use android_hardware_security_keymint::aidl::android::hardware::security::keymint::SecurityLevel::SecurityLevel;
 use android_security_rkp_aidl::aidl::android::security::rkp::{
     IGetKeyCallback::BnGetKeyCallback, IGetKeyCallback::ErrorCode::ErrorCode as GetKeyErrorCode,

keystore2/src/utils.rs

@@ -20,6 +20,7 @@ use crate::key_parameter::KeyParameter;
 use crate::ks_err;
 use crate::permission;
 use crate::permission::{KeyPerm, KeyPermSet, KeystorePerm};
+pub use crate::watchdog_helper::watchdog;
 use crate::{
     database::{KeyType, KeystoreDB},
     globals::LEGACY_IMPORTER,
@@ -421,36 +422,6 @@ pub fn count_key_entries(db: &mut KeystoreDB, domain: Domain, namespace: i64) ->
     Ok((legacy_keys.len() + num_keys_in_db) as i32)
 }
 
-/// This module provides helpers for simplified use of the watchdog module.
-#[cfg(feature = "watchdog")]
-pub mod watchdog {
-    pub use crate::watchdog::WatchPoint;
-    use crate::watchdog::Watchdog;
-    use lazy_static::lazy_static;
-    use std::sync::Arc;
-    use std::time::Duration;
-
-    lazy_static! {
-        /// A Watchdog thread, that can be used to create watch points.
-        static ref WD: Arc<Watchdog> = Watchdog::new(Duration::from_secs(10));
-    }
-
-    /// Sets a watch point with `id` and a timeout of `millis` milliseconds.
-    pub fn watch_millis(id: &'static str, millis: u64) -> Option<WatchPoint> {
-        Watchdog::watch(&WD, id, Duration::from_millis(millis))
-    }
-
-    /// Like `watch_millis` but with a callback that is called every time a report
-    /// is printed about this watch point.
-    pub fn watch_millis_with(
-        id: &'static str,
-        millis: u64,
-        callback: impl Fn() -> String + Send + 'static,
-    ) -> Option<WatchPoint> {
-        Watchdog::watch_with(&WD, id, Duration::from_millis(millis), callback)
-    }
-}
-
 /// Trait implemented by objects that can be used to decrypt cipher text using AES-GCM.
 pub trait AesGcm {
     /// Deciphers `data` using the initialization vector `iv` and AEAD tag `tag`
@@ -480,25 +451,6 @@ impl<T: AesGcmKey> AesGcm for T {
     }
 }
 
-/// This module provides empty/noop implementations of the watch dog utility functions.
-#[cfg(not(feature = "watchdog"))]
-pub mod watchdog {
-    /// Noop watch point.
-    pub struct WatchPoint();
-    /// Sets a Noop watch point.
-    fn watch_millis(_: &'static str, _: u64) -> Option<WatchPoint> {
-        None
-    }
-
-    pub fn watch_millis_with(
-        _: &'static str,
-        _: u64,
-        _: impl Fn() -> String + Send + 'static,
-    ) -> Option<WatchPoint> {
-        None
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

keystore2/src/watchdog_helper.rs

@@ -0,0 +1,64 @@
+// Copyright 2023, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Helpers for the watchdog module.
+
+/// This module provides helpers for simplified use of the watchdog module.
+#[cfg(feature = "watchdog")]
+pub mod watchdog {
+    use lazy_static::lazy_static;
+    use std::sync::Arc;
+    use std::time::Duration;
+    pub use watchdog_rs::WatchPoint;
+    use watchdog_rs::Watchdog;
+
+    lazy_static! {
+        /// A Watchdog thread, that can be used to create watch points.
+        static ref WD: Arc<Watchdog> = Watchdog::new(Duration::from_secs(10));
+    }
+
+    /// Sets a watch point with `id` and a timeout of `millis` milliseconds.
+    pub fn watch_millis(id: &'static str, millis: u64) -> Option<WatchPoint> {
+        Watchdog::watch(&WD, id, Duration::from_millis(millis))
+    }
+
+    /// Like `watch_millis` but with a callback that is called every time a report
+    /// is printed about this watch point.
+    pub fn watch_millis_with(
+        id: &'static str,
+        millis: u64,
+        callback: impl Fn() -> String + Send + 'static,
+    ) -> Option<WatchPoint> {
+        Watchdog::watch_with(&WD, id, Duration::from_millis(millis), callback)
+    }
+}
+
+/// This module provides empty/noop implementations of the watch dog utility functions.
+#[cfg(not(feature = "watchdog"))]
+pub mod watchdog {
+    /// Noop watch point.
+    pub struct WatchPoint();
+    /// Sets a Noop watch point.
+    fn watch_millis(_: &'static str, _: u64) -> Option<WatchPoint> {
+        None
+    }
+
+    pub fn watch_millis_with(
+        _: &'static str,
+        _: u64,
+        _: impl Fn() -> String + Send + 'static,
+    ) -> Option<WatchPoint> {
+        None
+    }
+}

keystore2/watchdog/Android.bp

@@ -0,0 +1,49 @@
+// Copyright 2023, The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "system_security_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["system_security_license"],
+}
+
+rust_defaults {
+    name: "libwatchdog_defaults",
+    crate_name: "watchdog_rs",
+    srcs: ["src/lib.rs"],
+    rustlibs: [
+        "liblog_rust",
+    ]
+}
+
+rust_library {
+    name: "libwatchdog_rs",
+    defaults: ["libwatchdog_defaults"],
+    apex_available: [
+        "//apex_available:platform",
+        "com.android.virt",
+    ],
+}
+
+rust_test {
+    name: "libwatchdog_rs.test",
+    defaults: ["libwatchdog_defaults"],
+    test_suites: ["general-tests"],
+    rustlibs: [
+        "libandroid_logger",
+    ]
+}