Merge "Add support for injecting RPC binder accessors to libbinder" into main am: d53d0744fc am: 97eba08623

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/3212539

Change-Id: Ib19906d467c56a3b85e98aeda3a0d6ed626b6378
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/libs/binder/BackendUnifiedServiceManager.cpp b/libs/binder/BackendUnifiedServiceManager.cpp
index 54f687b..fee36da 100644
--- a/libs/binder/BackendUnifiedServiceManager.cpp
+++ b/libs/binder/BackendUnifiedServiceManager.cpp
@@ -46,7 +46,9 @@
                                                          os::Service* _out) {
     os::Service service;
     binder::Status status = mTheRealServiceManager->getService2(name, &service);
-    toBinderService(service, _out);
+    if (status.isOk()) {
+        return toBinderService(name, service, _out);
+    }
     return status;
 }
 
@@ -54,15 +56,38 @@
                                                           os::Service* _out) {
     os::Service service;
     binder::Status status = mTheRealServiceManager->checkService(name, &service);
-    toBinderService(service, _out);
+    if (status.isOk()) {
+        return toBinderService(name, service, _out);
+    }
     return status;
 }
 
-void BackendUnifiedServiceManager::toBinderService(const os::Service& in, os::Service* _out) {
+binder::Status BackendUnifiedServiceManager::toBinderService(const ::std::string& name,
+                                                             const os::Service& in,
+                                                             os::Service* _out) {
     switch (in.getTag()) {
         case os::Service::Tag::binder: {
+            if (in.get<os::Service::Tag::binder>() == nullptr) {
+                // failed to find a service. Check to see if we have any local
+                // injected Accessors for this service.
+                os::Service accessor;
+                binder::Status status = getInjectedAccessor(name, &accessor);
+                if (!status.isOk()) {
+                    *_out = os::Service::make<os::Service::Tag::binder>(nullptr);
+                    return status;
+                }
+                if (accessor.getTag() == os::Service::Tag::accessor &&
+                    accessor.get<os::Service::Tag::accessor>() != nullptr) {
+                    ALOGI("Found local injected service for %s, will attempt to create connection",
+                          name.c_str());
+                    // Call this again using the accessor Service to get the real
+                    // service's binder into _out
+                    return toBinderService(name, accessor, _out);
+                }
+            }
+
             *_out = in;
-            break;
+            return binder::Status::ok();
         }
         case os::Service::Tag::accessor: {
             sp<IBinder> accessorBinder = in.get<os::Service::Tag::accessor>();
@@ -70,7 +95,7 @@
             if (accessor == nullptr) {
                 ALOGE("Service#accessor doesn't have accessor. VM is maybe starting...");
                 *_out = os::Service::make<os::Service::Tag::binder>(nullptr);
-                break;
+                return binder::Status::ok();
             }
             auto request = [=] {
                 os::ParcelFileDescriptor fd;
@@ -83,10 +108,15 @@
                 }
             };
             auto session = RpcSession::make();
-            session->setupPreconnectedClient(base::unique_fd{}, request);
+            status_t status = session->setupPreconnectedClient(base::unique_fd{}, request);
+            if (status != OK) {
+                ALOGE("Failed to set up preconnected binder RPC client: %s",
+                      statusToString(status).c_str());
+                return binder::Status::fromStatusT(status);
+            }
             session->setSessionSpecificRoot(accessorBinder);
             *_out = os::Service::make<os::Service::Tag::binder>(session->getRootObject());
-            break;
+            return binder::Status::ok();
         }
         default: {
             LOG_ALWAYS_FATAL("Unknown service type: %d", in.getTag());
@@ -177,4 +207,4 @@
     return gUnifiedServiceManager;
 }
 
-} // namespace android
\ No newline at end of file
+} // namespace android
diff --git a/libs/binder/BackendUnifiedServiceManager.h b/libs/binder/BackendUnifiedServiceManager.h
index 8f3839f..387eb35 100644
--- a/libs/binder/BackendUnifiedServiceManager.h
+++ b/libs/binder/BackendUnifiedServiceManager.h
@@ -59,9 +59,12 @@
 
 private:
     sp<os::IServiceManager> mTheRealServiceManager;
-    void toBinderService(const os::Service& in, os::Service* _out);
+    binder::Status toBinderService(const ::std::string& name, const os::Service& in,
+                                   os::Service* _out);
 };
 
 sp<BackendUnifiedServiceManager> getBackendUnifiedServiceManager();
 
-} // namespace android
\ No newline at end of file
+android::binder::Status getInjectedAccessor(const std::string& name, android::os::Service* service);
+
+} // namespace android
diff --git a/libs/binder/IServiceManager.cpp b/libs/binder/IServiceManager.cpp
index c55dd9d..cba21b2 100644
--- a/libs/binder/IServiceManager.cpp
+++ b/libs/binder/IServiceManager.cpp
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <sys/socket.h>
 #define LOG_TAG "ServiceManagerCppClient"
 
 #include <binder/IServiceManager.h>
@@ -24,14 +25,19 @@
 #include <chrono>
 #include <condition_variable>
 
+#include <FdTrigger.h>
+#include <RpcSocketAddress.h>
 #include <android-base/properties.h>
+#include <android/os/BnAccessor.h>
 #include <android/os/BnServiceCallback.h>
+#include <android/os/BnServiceManager.h>
 #include <android/os/IAccessor.h>
 #include <android/os/IServiceManager.h>
 #include <binder/IPCThreadState.h>
 #include <binder/Parcel.h>
+#include <binder/RpcSession.h>
 #include <utils/String8.h>
-
+#include <variant>
 #ifndef __ANDROID_VNDK__
 #include <binder/IPermissionController.h>
 #endif
@@ -148,8 +154,141 @@
     }
 };
 
+class AccessorProvider {
+public:
+    AccessorProvider(RpcAccessorProvider&& provider) : mProvider(provider) {}
+    sp<IBinder> provide(const String16& name) { return mProvider(name); }
+
+private:
+    AccessorProvider() = delete;
+
+    RpcAccessorProvider mProvider;
+};
+
+class AccessorProviderEntry {
+public:
+    AccessorProviderEntry(std::shared_ptr<AccessorProvider>&& provider) : mProvider(provider) {}
+    std::shared_ptr<AccessorProvider> mProvider;
+
+private:
+    AccessorProviderEntry() = delete;
+};
+
 [[clang::no_destroy]] static std::once_flag gSmOnce;
 [[clang::no_destroy]] static sp<IServiceManager> gDefaultServiceManager;
+[[clang::no_destroy]] static std::mutex gAccessorProvidersMutex;
+[[clang::no_destroy]] static std::vector<AccessorProviderEntry> gAccessorProviders;
+
+class LocalAccessor : public android::os::BnAccessor {
+public:
+    LocalAccessor(const String16& instance, RpcSocketAddressProvider&& connectionInfoProvider)
+          : mInstance(instance), mConnectionInfoProvider(connectionInfoProvider) {
+        LOG_ALWAYS_FATAL_IF(!mConnectionInfoProvider,
+                            "LocalAccessor object needs a valid connection info provider");
+    }
+
+    ~LocalAccessor() {
+        if (mOnDelete) mOnDelete();
+    }
+
+    ::android::binder::Status addConnection(::android::os::ParcelFileDescriptor* outFd) {
+        using android::os::IAccessor;
+        sockaddr_storage addrStorage;
+        std::unique_ptr<FdTrigger> trigger = FdTrigger::make();
+        RpcTransportFd fd;
+        status_t status =
+                mConnectionInfoProvider(mInstance, reinterpret_cast<sockaddr*>(&addrStorage),
+                                        sizeof(addrStorage));
+        if (status != OK) {
+            const std::string error = "The connection info provider was unable to provide "
+                                      "connection info for instance " +
+                    std::string(String8(mInstance).c_str()) +
+                    " with status: " + statusToString(status);
+            ALOGE("%s", error.c_str());
+            return Status::fromServiceSpecificError(IAccessor::ERROR_CONNECTION_INFO_NOT_FOUND,
+                                                    error.c_str());
+        }
+        if (addrStorage.ss_family == AF_VSOCK) {
+            sockaddr_vm* addr = reinterpret_cast<sockaddr_vm*>(&addrStorage);
+            status = singleSocketConnection(VsockSocketAddress(addr->svm_cid, addr->svm_port),
+                                            trigger, &fd);
+        } else if (addrStorage.ss_family == AF_UNIX) {
+            sockaddr_un* addr = reinterpret_cast<sockaddr_un*>(&addrStorage);
+            status = singleSocketConnection(UnixSocketAddress(addr->sun_path), trigger, &fd);
+        } else if (addrStorage.ss_family == AF_INET) {
+            sockaddr_in* addr = reinterpret_cast<sockaddr_in*>(&addrStorage);
+            status = singleSocketConnection(InetSocketAddress(reinterpret_cast<sockaddr*>(addr),
+                                                              sizeof(sockaddr_in),
+                                                              inet_ntoa(addr->sin_addr),
+                                                              ntohs(addr->sin_port)),
+                                            trigger, &fd);
+        } else {
+            const std::string error =
+                    "Unsupported socket family type or the ConnectionInfoProvider failed to find a "
+                    "valid address. Family type: " +
+                    std::to_string(addrStorage.ss_family);
+            ALOGE("%s", error.c_str());
+            return Status::fromServiceSpecificError(IAccessor::ERROR_UNSUPPORTED_SOCKET_FAMILY,
+                                                    error.c_str());
+        }
+        if (status != OK) {
+            const std::string error = "Failed to connect to socket for " +
+                    std::string(String8(mInstance).c_str()) +
+                    " with status: " + statusToString(status);
+            ALOGE("%s", error.c_str());
+            int err = 0;
+            if (status == -EACCES) {
+                err = IAccessor::ERROR_FAILED_TO_CONNECT_EACCES;
+            } else {
+                err = IAccessor::ERROR_FAILED_TO_CONNECT_TO_SOCKET;
+            }
+            return Status::fromServiceSpecificError(err, error.c_str());
+        }
+        *outFd = os::ParcelFileDescriptor(std::move(fd.fd));
+        return Status::ok();
+    }
+
+    ::android::binder::Status getInstanceName(String16* instance) {
+        *instance = mInstance;
+        return Status::ok();
+    }
+
+private:
+    LocalAccessor() = delete;
+    String16 mInstance;
+    RpcSocketAddressProvider mConnectionInfoProvider;
+    std::function<void()> mOnDelete;
+};
+
+android::binder::Status getInjectedAccessor(const std::string& name,
+                                            android::os::Service* service) {
+    std::vector<AccessorProviderEntry> copiedProviders;
+    {
+        std::lock_guard<std::mutex> lock(gAccessorProvidersMutex);
+        copiedProviders.insert(copiedProviders.begin(), gAccessorProviders.begin(),
+                               gAccessorProviders.end());
+    }
+
+    // Unlocked to call the providers. This requires the providers to be
+    // threadsafe and not contain any references to objects that could be
+    // deleted.
+    for (const auto& provider : copiedProviders) {
+        sp<IBinder> binder = provider.mProvider->provide(String16(name.c_str()));
+        if (binder == nullptr) continue;
+        status_t status = validateAccessor(String16(name.c_str()), binder);
+        if (status != OK) {
+            ALOGE("A provider returned a binder that is not an IAccessor for instance %s. Status: "
+                  "%s",
+                  name.c_str(), statusToString(status).c_str());
+            return android::binder::Status::fromStatusT(android::INVALID_OPERATION);
+        }
+        *service = os::Service::make<os::Service::Tag::accessor>(binder);
+        return android::binder::Status::ok();
+    }
+
+    *service = os::Service::make<os::Service::Tag::accessor>(nullptr);
+    return android::binder::Status::ok();
+}
 
 sp<IServiceManager> defaultServiceManager()
 {
@@ -172,6 +311,75 @@
     }
 }
 
+std::weak_ptr<AccessorProvider> addAccessorProvider(RpcAccessorProvider&& providerCallback) {
+    std::lock_guard<std::mutex> lock(gAccessorProvidersMutex);
+    std::shared_ptr<AccessorProvider> provider =
+            std::make_shared<AccessorProvider>(std::move(providerCallback));
+    gAccessorProviders.push_back(AccessorProviderEntry(std::move(provider)));
+
+    return provider;
+}
+
+status_t removeAccessorProvider(std::weak_ptr<AccessorProvider> wProvider) {
+    std::shared_ptr<AccessorProvider> provider = wProvider.lock();
+    if (provider == nullptr) {
+        ALOGE("The provider supplied to removeAccessorProvider has already been removed.");
+        return NAME_NOT_FOUND;
+    }
+    std::lock_guard<std::mutex> lock(gAccessorProvidersMutex);
+    size_t sizeBefore = gAccessorProviders.size();
+    gAccessorProviders.erase(std::remove_if(gAccessorProviders.begin(), gAccessorProviders.end(),
+                                            [&](AccessorProviderEntry entry) {
+                                                return entry.mProvider == provider;
+                                            }),
+                             gAccessorProviders.end());
+    if (sizeBefore == gAccessorProviders.size()) {
+        ALOGE("Failed to find an AccessorProvider for removeAccessorProvider");
+        return NAME_NOT_FOUND;
+    }
+
+    return OK;
+}
+
+status_t validateAccessor(const String16& instance, const sp<IBinder>& binder) {
+    if (binder == nullptr) {
+        ALOGE("Binder is null");
+        return BAD_VALUE;
+    }
+    sp<IAccessor> accessor = interface_cast<IAccessor>(binder);
+    if (accessor == nullptr) {
+        ALOGE("This binder for %s is not an IAccessor binder", String8(instance).c_str());
+        return BAD_TYPE;
+    }
+    String16 reportedInstance;
+    Status status = accessor->getInstanceName(&reportedInstance);
+    if (!status.isOk()) {
+        ALOGE("Failed to validate the binder being used to create a new ARpc_Accessor for %s with "
+              "status: %s",
+              String8(instance).c_str(), status.toString8().c_str());
+        return NAME_NOT_FOUND;
+    }
+    if (reportedInstance != instance) {
+        ALOGE("Instance %s doesn't match the Accessor's instance of %s", String8(instance).c_str(),
+              String8(reportedInstance).c_str());
+        return NAME_NOT_FOUND;
+    }
+    return OK;
+}
+
+sp<IBinder> createAccessor(const String16& instance,
+                           RpcSocketAddressProvider&& connectionInfoProvider) {
+    // Try to create a new accessor
+    if (!connectionInfoProvider) {
+        ALOGE("Could not find an Accessor for %s and no ConnectionInfoProvider provided to "
+              "create a new one",
+              String8(instance).c_str());
+        return nullptr;
+    }
+    sp<IBinder> binder = sp<LocalAccessor>::make(instance, std::move(connectionInfoProvider));
+    return binder;
+}
+
 #if !defined(__ANDROID_VNDK__)
 // IPermissionController is not accessible to vendors
 
diff --git a/libs/binder/RpcSession.cpp b/libs/binder/RpcSession.cpp
index 49def82..cd21a91 100644
--- a/libs/binder/RpcSession.cpp
+++ b/libs/binder/RpcSession.cpp
@@ -589,6 +589,21 @@
 status_t RpcSession::setupOneSocketConnection(const RpcSocketAddress& addr,
                                               const std::vector<uint8_t>& sessionId,
                                               bool incoming) {
+    RpcTransportFd transportFd;
+    status_t status = singleSocketConnection(addr, mShutdownTrigger, &transportFd);
+    if (status != OK) return status;
+
+    return initAndAddConnection(std::move(transportFd), sessionId, incoming);
+}
+
+status_t singleSocketConnection(const RpcSocketAddress& addr,
+                                const std::unique_ptr<FdTrigger>& shutdownTrigger,
+                                RpcTransportFd* outFd) {
+    LOG_ALWAYS_FATAL_IF(outFd == nullptr,
+                        "There is no reason to call this function without an outFd");
+    LOG_ALWAYS_FATAL_IF(shutdownTrigger == nullptr,
+                        "FdTrigger argument is required so we don't get stuck in the connect call "
+                        "if the server process shuts down.");
     for (size_t tries = 0; tries < 5; tries++) {
         if (tries > 0) usleep(10000);
 
@@ -620,7 +635,7 @@
             if (connErrno == EAGAIN || connErrno == EINPROGRESS) {
                 // For non-blocking sockets, connect() may return EAGAIN (for unix domain socket) or
                 // EINPROGRESS (for others). Call poll() and getsockopt() to get the error.
-                status_t pollStatus = mShutdownTrigger->triggerablePoll(transportFd, POLLOUT);
+                status_t pollStatus = shutdownTrigger->triggerablePoll(transportFd, POLLOUT);
                 if (pollStatus != OK) {
                     ALOGE("Could not POLLOUT after connect() on non-blocking socket: %s",
                           statusToString(pollStatus).c_str());
@@ -654,7 +669,8 @@
         LOG_RPC_DETAIL("Socket at %s client with fd %d", addr.toString().c_str(),
                        transportFd.fd.get());
 
-        return initAndAddConnection(std::move(transportFd), sessionId, incoming);
+        *outFd = std::move(transportFd);
+        return OK;
     }
 
     ALOGE("Ran out of retries to connect to %s", addr.toString().c_str());
diff --git a/libs/binder/RpcSocketAddress.h b/libs/binder/RpcSocketAddress.h
index c7ba5d9..ee7d448 100644
--- a/libs/binder/RpcSocketAddress.h
+++ b/libs/binder/RpcSocketAddress.h
@@ -113,4 +113,11 @@
     unsigned int mPort;
 };
 
+/**
+ * Connects to a single socket and produces a RpcTransportFd.
+ */
+status_t singleSocketConnection(const RpcSocketAddress& address,
+                                const std::unique_ptr<FdTrigger>& shutdownTrigger,
+                                RpcTransportFd* outFd);
+
 } // namespace android
diff --git a/libs/binder/aidl/android/os/IAccessor.aidl b/libs/binder/aidl/android/os/IAccessor.aidl
index a3134a3..c06e05c 100644
--- a/libs/binder/aidl/android/os/IAccessor.aidl
+++ b/libs/binder/aidl/android/os/IAccessor.aidl
@@ -25,15 +25,56 @@
  */
 interface IAccessor {
     /**
+     * The connection info was not available for this service.
+     * This happens when the user-supplied callback fails to produce
+     * valid connection info.
+     * Depending on the implementation of the callback, it might be helpful
+     * to retry.
+     */
+    const int ERROR_CONNECTION_INFO_NOT_FOUND = 0;
+    /**
+     * Failed to create the socket. Often happens when the process trying to create
+     * the socket lacks the permissions to do so.
+     * This may be a temporary issue, so retrying the operation is OK.
+     */
+    const int ERROR_FAILED_TO_CREATE_SOCKET = 1;
+    /**
+     * Failed to connect to the socket. This can happen for many reasons, so be sure
+     * log the error message and check it.
+     * This may be a temporary issue, so retrying the operation is OK.
+     */
+    const int ERROR_FAILED_TO_CONNECT_TO_SOCKET = 2;
+    /**
+     * Failed to connect to the socket with EACCES because this process does not
+     * have perimssions to connect.
+     * There is no need to retry the connection as this access will not be granted
+     * upon retry.
+     */
+    const int ERROR_FAILED_TO_CONNECT_EACCES = 3;
+    /**
+     * Unsupported socket family type returned.
+     * There is no need to retry the connection as this socket family is not
+     * supported.
+     */
+    const int ERROR_UNSUPPORTED_SOCKET_FAMILY = 4;
+
+    /**
      * Adds a connection to the RPC server of the service managed by the IAccessor.
      *
      * This method can be called multiple times to establish multiple distinct
      * connections to the same RPC server.
      *
+     * @throws ServiceSpecificError with message and one of the IAccessor::ERROR_ values.
+     *
      * @return A file descriptor connected to the RPC session of the service managed
      *         by IAccessor.
      */
     ParcelFileDescriptor addConnection();
 
-    // TODO(b/350941051): Add API for debugging.
+    /**
+     * Get the instance name for the service this accessor is responsible for.
+     *
+     * This is used to verify the proxy binder is associated with the expected instance name.
+     */
+    String getInstanceName();
 }
diff --git a/libs/binder/include/binder/IServiceManager.h b/libs/binder/include/binder/IServiceManager.h
index 5fb7307..879f319 100644
--- a/libs/binder/include/binder/IServiceManager.h
+++ b/libs/binder/include/binder/IServiceManager.h
@@ -17,14 +17,16 @@
 #pragma once
 #include <binder/Common.h>
 #include <binder/IInterface.h>
-#include <utils/Vector.h>
+// Trusty has its own definition of socket APIs from trusty_ipc.h
+#ifndef __TRUSTY__
+#include <sys/socket.h>
+#endif // __TRUSTY__
 #include <utils/String16.h>
+#include <utils/Vector.h>
 #include <optional>
 
 namespace android {
 
-// ----------------------------------------------------------------------
-
 /**
  * Service manager for C++ services.
  *
@@ -216,6 +218,64 @@
 LIBBINDER_EXPORTED bool checkPermission(const String16& permission, pid_t pid, uid_t uid,
                                         bool logPermissionFailure = true);
 
+// ----------------------------------------------------------------------
+// Trusty's definition of the socket APIs does not include sockaddr types
+#ifndef __TRUSTY__
+typedef std::function<status_t(const String16& name, sockaddr* outAddr, socklen_t addrSize)>
+        RpcSocketAddressProvider;
+
+typedef std::function<sp<IBinder>(const String16& name)> RpcAccessorProvider;
+
+class AccessorProvider;
+
+/**
+ * Register an accessor provider for the service manager APIs.
+ *
+ * \param provider callback that generates Accessors.
+ *
+ * \return A pointer used as a recept for the successful addition of the
+ *         AccessorProvider. This is needed to unregister it later.
+ */
+[[nodiscard]] LIBBINDER_EXPORTED std::weak_ptr<AccessorProvider> addAccessorProvider(
+        RpcAccessorProvider&& providerCallback);
+
+/**
+ * Remove an accessor provider using the pointer provided by addAccessorProvider
+ * along with the cookie pointer that was used.
+ *
+ * \param provider cookie that was returned by addAccessorProvider to keep track
+ *        of this instance.
+ */
+[[nodiscard]] LIBBINDER_EXPORTED status_t
+removeAccessorProvider(std::weak_ptr<AccessorProvider> provider);
+
+/**
+ * Create an Accessor associated with a service that can create a socket connection based
+ * on the connection info from the supplied RpcSocketAddressProvider.
+ *
+ * \param instance name of the service that this Accessor is associated with
+ * \param connectionInfoProvider a callback that returns connection info for
+ *        connecting to the service.
+ * \return the binder of the IAccessor implementation from libbinder
+ */
+LIBBINDER_EXPORTED sp<IBinder> createAccessor(const String16& instance,
+                                              RpcSocketAddressProvider&& connectionInfoProvider);
+
+/**
+ * Check to make sure this binder is the expected binder that is an IAccessor
+ * associated with a specific instance.
+ *
+ * This helper function exists to avoid adding the IAccessor type to
+ * libbinder_ndk.
+ *
+ * \param instance name of the service that this Accessor should be associated with
+ * \param binder to validate
+ *
+ * \return OK if the binder is an IAccessor for `instance`
+ */
+LIBBINDER_EXPORTED status_t validateAccessor(const String16& instance, const sp<IBinder>& binder);
+#endif // __TRUSTY__
+
 #ifndef __ANDROID__
 // Create an IServiceManager that delegates the service manager on the device via adb.
 // This is can be set as the default service manager at program start, so that
diff --git a/libs/binder/tests/binderRpcTest.cpp b/libs/binder/tests/binderRpcTest.cpp
index 3038de9..fbca35e 100644
--- a/libs/binder/tests/binderRpcTest.cpp
+++ b/libs/binder/tests/binderRpcTest.cpp
@@ -365,26 +365,57 @@
         session->setMaxOutgoingConnections(options.numOutgoingConnections);
         session->setFileDescriptorTransportMode(options.clientFileDescriptorTransportMode);
 
+        sockaddr_storage addr{};
+        socklen_t addrLen = 0;
+
         switch (socketType) {
-            case SocketType::PRECONNECTED:
+            case SocketType::PRECONNECTED: {
+                sockaddr_un addr_un{};
+                addr_un.sun_family = AF_UNIX;
+                strcpy(addr_un.sun_path, serverConfig.addr.c_str());
+                addr = *reinterpret_cast<sockaddr_storage*>(&addr_un);
+                addrLen = sizeof(sockaddr_un);
+
                 status = session->setupPreconnectedClient({}, [=]() {
                     return connectTo(UnixSocketAddress(serverConfig.addr.c_str()));
                 });
-                break;
+            } break;
             case SocketType::UNIX_RAW:
-            case SocketType::UNIX:
+            case SocketType::UNIX: {
+                sockaddr_un addr_un{};
+                addr_un.sun_family = AF_UNIX;
+                strcpy(addr_un.sun_path, serverConfig.addr.c_str());
+                addr = *reinterpret_cast<sockaddr_storage*>(&addr_un);
+                addrLen = sizeof(sockaddr_un);
+
                 status = session->setupUnixDomainClient(serverConfig.addr.c_str());
-                break;
+            } break;
             case SocketType::UNIX_BOOTSTRAP:
                 status = session->setupUnixDomainSocketBootstrapClient(
                         unique_fd(dup(bootstrapClientFd.get())));
                 break;
-            case SocketType::VSOCK:
+            case SocketType::VSOCK: {
+                sockaddr_vm addr_vm{
+                        .svm_family = AF_VSOCK,
+                        .svm_port = static_cast<unsigned int>(serverInfo.port),
+                        .svm_cid = VMADDR_CID_LOCAL,
+                };
+                addr = *reinterpret_cast<sockaddr_storage*>(&addr_vm);
+                addrLen = sizeof(sockaddr_vm);
+
                 status = session->setupVsockClient(VMADDR_CID_LOCAL, serverInfo.port);
-                break;
-            case SocketType::INET:
-                status = session->setupInetClient("127.0.0.1", serverInfo.port);
-                break;
+            } break;
+            case SocketType::INET: {
+                const std::string ip_addr = "127.0.0.1";
+                sockaddr_in addr_in{};
+                addr_in.sin_family = AF_INET;
+                addr_in.sin_port = htons(serverInfo.port);
+                inet_aton(ip_addr.c_str(), &addr_in.sin_addr);
+                addr = *reinterpret_cast<sockaddr_storage*>(&addr_in);
+                addrLen = sizeof(sockaddr_in);
+
+                status = session->setupInetClient(ip_addr.c_str(), serverInfo.port);
+            } break;
             case SocketType::TIPC:
                 status = session->setupPreconnectedClient({}, [=]() {
 #ifdef BINDER_RPC_TO_TRUSTY_TEST
@@ -413,7 +444,7 @@
             break;
         }
         LOG_ALWAYS_FATAL_IF(status != OK, "Could not connect: %s", statusToString(status).c_str());
-        ret->sessions.push_back({session, session->getRootObject()});
+        ret->sessions.push_back({session, session->getRootObject(), addr, addrLen});
     }
     return ret;
 }
@@ -1127,6 +1158,139 @@
     ASSERT_EQ(beforeFds, countFds()) << (system("ls -l /proc/self/fd/"), "fd leak?");
 }
 
+// TODO need to add IServiceManager.cpp/.h to libbinder_no_kernel
+#ifdef BINDER_WITH_KERNEL_IPC
+
+class BinderRpcAccessor : public BinderRpc {
+    void SetUp() override {
+        if (serverSingleThreaded()) {
+            // This blocks on android::FdTrigger::triggerablePoll when attempting to set
+            // up the client RpcSession
+            GTEST_SKIP() << "Accessors are not supported for single threaded libbinder";
+        }
+        if (rpcSecurity() == RpcSecurity::TLS) {
+            GTEST_SKIP() << "Accessors are not supported with TLS";
+            // ... for now
+        }
+
+        if (socketType() == SocketType::UNIX_BOOTSTRAP) {
+            GTEST_SKIP() << "Accessors do not support UNIX_BOOTSTRAP because no connection "
+                            "information is known";
+        }
+        if (socketType() == SocketType::TIPC) {
+            GTEST_SKIP() << "Accessors do not support TIPC because the socket transport is not "
+                            "known in libbinder";
+        }
+        BinderRpc::SetUp();
+    }
+};
+
+inline void waitForExtraSessionCleanup(const BinderRpcTestProcessSession& proc) {
+    // Need to give the server some time to delete its RpcSession after our last
+    // reference is dropped, closing the connection. Check for up to 1 second,
+    // every 10 ms.
+    for (size_t i = 0; i < 100; i++) {
+        std::vector<int32_t> remoteCounts;
+        EXPECT_OK(proc.rootIface->countBinders(&remoteCounts));
+        // We exect the original binder to still be alive, we just want to wait
+        // for this extra session to be cleaned up.
+        if (remoteCounts.size() == proc.proc->sessions.size()) break;
+        usleep(10000);
+    }
+}
+
+TEST_P(BinderRpcAccessor, InjectAndGetServiceHappyPath) {
+    constexpr size_t kNumThreads = 10;
+    const String16 kInstanceName("super.cool.service/better_than_default");
+
+    auto proc = createRpcTestSocketServerProcess({.numThreads = kNumThreads});
+    EXPECT_EQ(OK, proc.rootBinder->pingBinder());
+
+    auto receipt = addAccessorProvider([&](const String16& name) -> sp<IBinder> {
+        return createAccessor(name,
+                              [&](const String16& name, sockaddr* outAddr,
+                                  socklen_t addrSize) -> status_t {
+                                  if (outAddr == nullptr ||
+                                      addrSize < proc.proc->sessions[0].addrLen) {
+                                      return BAD_VALUE;
+                                  }
+                                  if (name == kInstanceName) {
+                                      if (proc.proc->sessions[0].addr.ss_family == AF_UNIX) {
+                                          sockaddr_un* un = reinterpret_cast<sockaddr_un*>(
+                                                  &proc.proc->sessions[0].addr);
+                                          ALOGE("inside callback: %s", un->sun_path);
+                                      }
+                                      std::memcpy(outAddr, &proc.proc->sessions[0].addr,
+                                                  proc.proc->sessions[0].addrLen);
+                                      return OK;
+                                  }
+                                  return NAME_NOT_FOUND;
+                              });
+    });
+
+    EXPECT_FALSE(receipt.expired());
+
+    sp<IBinder> binder = defaultServiceManager()->checkService(kInstanceName);
+    sp<IBinderRpcTest> service = checked_interface_cast<IBinderRpcTest>(binder);
+    EXPECT_NE(service, nullptr);
+
+    sp<IBinder> out;
+    EXPECT_OK(service->repeatBinder(binder, &out));
+    EXPECT_EQ(binder, out);
+
+    out.clear();
+    binder.clear();
+    service.clear();
+
+    status_t status = removeAccessorProvider(receipt);
+    EXPECT_EQ(status, OK);
+
+    waitForExtraSessionCleanup(proc);
+}
+
+TEST_P(BinderRpcAccessor, InjectNoAccessorProvided) {
+    const String16 kInstanceName("doesnt_matter_nothing_checks");
+
+    bool isProviderDeleted = false;
+
+    auto receipt = addAccessorProvider([&](const String16&) -> sp<IBinder> { return nullptr; });
+    EXPECT_FALSE(receipt.expired());
+
+    sp<IBinder> binder = defaultServiceManager()->checkService(kInstanceName);
+    EXPECT_EQ(binder, nullptr);
+
+    status_t status = removeAccessorProvider(receipt);
+    EXPECT_EQ(status, OK);
+}
+
+TEST_P(BinderRpcAccessor, InjectNoSockaddrProvided) {
+    constexpr size_t kNumThreads = 10;
+    const String16 kInstanceName("super.cool.service/better_than_default");
+
+    auto proc = createRpcTestSocketServerProcess({.numThreads = kNumThreads});
+    EXPECT_EQ(OK, proc.rootBinder->pingBinder());
+
+    bool isProviderDeleted = false;
+    bool isAccessorDeleted = false;
+
+    auto receipt = addAccessorProvider([&](const String16& name) -> sp<IBinder> {
+        return createAccessor(name, [&](const String16&, sockaddr*, socklen_t) -> status_t {
+            // don't fill in outAddr
+            return NAME_NOT_FOUND;
+        });
+    });
+
+    EXPECT_FALSE(receipt.expired());
+
+    sp<IBinder> binder = defaultServiceManager()->checkService(kInstanceName);
+    EXPECT_EQ(binder, nullptr);
+
+    status_t status = removeAccessorProvider(receipt);
+    EXPECT_EQ(status, OK);
+}
+
+#endif // BINDER_WITH_KERNEL_IPC
+
 #ifdef BINDER_RPC_TO_TRUSTY_TEST
 
 static std::vector<BinderRpc::ParamType> getTrustyBinderRpcParams() {
@@ -1315,6 +1479,11 @@
 INSTANTIATE_TEST_SUITE_P(PerSocket, BinderRpc, ::testing::ValuesIn(getBinderRpcParams()),
                          BinderRpc::PrintParamInfo);
 
+#ifdef BINDER_WITH_KERNEL_IPC
+INSTANTIATE_TEST_SUITE_P(PerSocket, BinderRpcAccessor, ::testing::ValuesIn(getBinderRpcParams()),
+                         BinderRpc::PrintParamInfo);
+#endif // BINDER_WITH_KERNEL_IPC
+
 class BinderRpcServerRootObject
       : public ::testing::TestWithParam<std::tuple<bool, bool, RpcSecurity>> {};
 
diff --git a/libs/binder/tests/binderRpcTestFixture.h b/libs/binder/tests/binderRpcTestFixture.h
index 2c9646b..c8a8acc 100644
--- a/libs/binder/tests/binderRpcTestFixture.h
+++ b/libs/binder/tests/binderRpcTestFixture.h
@@ -35,6 +35,12 @@
     struct SessionInfo {
         sp<RpcSession> session;
         sp<IBinder> root;
+// Trusty defines its own socket APIs in trusty_ipc.h but doesn't include
+// sockaddr types.
+#ifndef __TRUSTY__
+        sockaddr_storage addr;
+        socklen_t addrLen;
+#endif
     };
 
     // client session objects associated with other process