From 01d5a1d2f12f16c6f36309eab5cec9fd5a413933 Mon Sep 17 00:00:00 2001
From: Daniel Zheng <zhengdaniel@google.com>
Date: Wed, 16 Oct 2024 14:09:50 -0700
Subject: [PATCH] bootctl: fix reconnect logic

Instead of just logging an error message, let's try reonnecting to the
bootctl service if our death recipient is invoked. We should also
reconnect our death recipient here.

If binder is killed, our death recipient is automatically unlinked.

Bug: 369289491
Test: kill bootctl service on CVD. Apply OTA
Change-Id: I914643baaf1fa6fe1e192517a2e43e07ee749b70
---
 boot/aidl/client/BootControlClient.cpp | 30 ++++++++++++++++++++------
 1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/boot/aidl/client/BootControlClient.cpp b/boot/aidl/client/BootControlClient.cpp
index 10f0ffe2e9..090d62416a 100644
--- a/boot/aidl/client/BootControlClient.cpp
+++ b/boot/aidl/client/BootControlClient.cpp
@@ -79,14 +79,32 @@ class BootControlClientAidl final : public BootControlClient {
 
     BootControlVersion GetVersion() const override { return BootControlVersion::BOOTCTL_AIDL; }
 
-    ~BootControlClientAidl() {
-        if (boot_control_death_recipient) {
-            AIBinder_unlinkToDeath(module_->asBinder().get(), boot_control_death_recipient, this);
+    void onBootControlServiceDied() {
+        LOG(ERROR) << "boot control service AIDL died. Attempting to reconnect...";
+        const auto instance_name =
+                std::string(::aidl::android::hardware::boot::IBootControl::descriptor) + "/default";
+        if (AServiceManager_isDeclared(instance_name.c_str())) {
+            module_ = ::aidl::android::hardware::boot::IBootControl::fromBinder(
+                    ndk::SpAIBinder(AServiceManager_waitForService(instance_name.c_str())));
+            if (module_ == nullptr) {
+                LOG(ERROR) << "AIDL " << instance_name
+                           << " is declared but waitForService returned nullptr when trying to "
+                              "reconnect boot control service";
+                return;
+            }
+            LOG(INFO) << "Reconnected to AIDL version of IBootControl";
+            binder_status_t status = AIBinder_linkToDeath(module_->asBinder().get(),
+                                                          boot_control_death_recipient, this);
+            if (status != STATUS_OK) {
+                LOG(ERROR) << "Could not link to binder death";
+                return;
+            }
+
+        } else {
+            LOG(ERROR) << "Failed to get service manager for: " << instance_name;
         }
     }
 
-    void onBootControlServiceDied() { LOG(ERROR) << "boot control service AIDL died"; }
-
     int32_t GetNumSlots() const override {
         int32_t ret = -1;
         LOG_NDK_STATUS(module_->getNumberSlots(&ret));
@@ -179,7 +197,7 @@ class BootControlClientAidl final : public BootControlClient {
     }
 
   private:
-    const std::shared_ptr<IBootControl> module_;
+    std::shared_ptr<IBootControl> module_;
     AIBinder_DeathRecipient* boot_control_death_recipient;
     static void onBootControlServiceDied(void* client) {
         BootControlClientAidl* self = static_cast<BootControlClientAidl*>(client);