From dc207544897a30fe412ffcc0deab07dd974358d1 Mon Sep 17 00:00:00 2001
From: Parth Sane <parthsane@google.com>
Date: Thu, 14 Nov 2024 11:49:08 +0000
Subject: Add binder to libbinder cache after addService

This will prevent system_server and other applications
from calling servicemanager for local binders.

Flag: RELEASE_LIBBINDER_CLIENT_CACHE
Bug: 333854840
Test: atest binderCacheUnitTest
Change-Id: I2693f21a3f5b7a5770481e5ac79719444284524d
---
 libs/binder/BackendUnifiedServiceManager.cpp | 58 ++++++++++++++++++----------
 1 file changed, 37 insertions(+), 21 deletions(-)

(limited to 'libs/binder/BackendUnifiedServiceManager.cpp')

diff --git a/libs/binder/BackendUnifiedServiceManager.cpp b/libs/binder/BackendUnifiedServiceManager.cpp
index d32eecdc60..123dfd2c05 100644
--- a/libs/binder/BackendUnifiedServiceManager.cpp
+++ b/libs/binder/BackendUnifiedServiceManager.cpp
@@ -30,6 +30,12 @@ constexpr bool kUseCache = true;
 constexpr bool kUseCache = false;
 #endif
 
+#ifdef LIBBINDER_ADDSERVICE_CACHE
+constexpr bool kUseCacheInAddService = true;
+#else
+constexpr bool kUseCacheInAddService = false;
+#endif
+
 using AidlServiceManager = android::os::IServiceManager;
 using android::os::IAccessor;
 using binder::Status;
@@ -125,31 +131,36 @@ Status BackendUnifiedServiceManager::updateCache(const std::string& serviceName,
     if (!kUseCache) {
         return Status::ok();
     }
+
+    if (service.getTag() == os::Service::Tag::binder) {
+        return updateCache(serviceName, service.get<os::Service::Tag::binder>());
+    }
+    return Status::ok();
+}
+
+Status BackendUnifiedServiceManager::updateCache(const std::string& serviceName,
+                                                 const sp<IBinder>& binder) {
     std::string traceStr;
     if (atrace_is_tag_enabled(ATRACE_TAG_AIDL)) {
         traceStr = "BinderCacheWithInvalidation::updateCache : " + serviceName;
     }
     binder::ScopedTrace aidlTrace(ATRACE_TAG_AIDL, traceStr.c_str());
-
-    if (service.getTag() == os::Service::Tag::binder) {
-        sp<IBinder> binder = service.get<os::Service::Tag::binder>();
-        if (!binder) {
-            binder::ScopedTrace
-                    aidlTrace(ATRACE_TAG_AIDL,
-                              "BinderCacheWithInvalidation::updateCache failed: binder_null");
-        } else if (!binder->isBinderAlive()) {
-            binder::ScopedTrace aidlTrace(ATRACE_TAG_AIDL,
-                                          "BinderCacheWithInvalidation::updateCache failed: "
-                                          "isBinderAlive_false");
-        } else if (mCacheForGetService->isClientSideCachingEnabled(serviceName)) {
-            binder::ScopedTrace aidlTrace(ATRACE_TAG_AIDL,
-                                          "BinderCacheWithInvalidation::updateCache successful");
-            return mCacheForGetService->setItem(serviceName, binder);
-        } else {
-            binder::ScopedTrace aidlTrace(ATRACE_TAG_AIDL,
-                                          "BinderCacheWithInvalidation::updateCache failed: "
-                                          "caching_not_enabled");
-        }
+    if (!binder) {
+        binder::ScopedTrace
+                aidlTrace(ATRACE_TAG_AIDL,
+                          "BinderCacheWithInvalidation::updateCache failed: binder_null");
+    } else if (!binder->isBinderAlive()) {
+        binder::ScopedTrace aidlTrace(ATRACE_TAG_AIDL,
+                                      "BinderCacheWithInvalidation::updateCache failed: "
+                                      "isBinderAlive_false");
+    } else if (mCacheForGetService->isClientSideCachingEnabled(serviceName)) {
+        binder::ScopedTrace aidlTrace(ATRACE_TAG_AIDL,
+                                      "BinderCacheWithInvalidation::updateCache successful");
+        return mCacheForGetService->setItem(serviceName, binder);
+    } else {
+        binder::ScopedTrace aidlTrace(ATRACE_TAG_AIDL,
+                                      "BinderCacheWithInvalidation::updateCache failed: "
+                                      "caching_not_enabled");
     }
     return Status::ok();
 }
@@ -277,7 +288,12 @@ Status BackendUnifiedServiceManager::toBinderService(const ::std::string& name,
 Status BackendUnifiedServiceManager::addService(const ::std::string& name,
                                                 const sp<IBinder>& service, bool allowIsolated,
                                                 int32_t dumpPriority) {
-    return mTheRealServiceManager->addService(name, service, allowIsolated, dumpPriority);
+    Status status = mTheRealServiceManager->addService(name, service, allowIsolated, dumpPriority);
+    // mEnableAddServiceCache is true by default.
+    if (kUseCacheInAddService && mEnableAddServiceCache && status.isOk()) {
+        return updateCache(name, service);
+    }
+    return status;
 }
 Status BackendUnifiedServiceManager::listServices(int32_t dumpPriority,
                                                   ::std::vector<::std::string>* _aidl_return) {
-- 
cgit v1.2.3-59-g8ed1b