Move getService into libhidl.

This function is huge! By moving it out of auto-generated
code, we can do a couple of things:
- decrease the amount of space it takes (no longer not 'all'
  templated).
- make it easier to fix bugs like b/67425500

Bug: 67425500
Test: hidl_test, hidl_test_java

Change-Id: Ic8eb93d82e7bf8a6730d14109a36828bfe9d468a
diff --git a/transport/Android.bp b/transport/Android.bp
index 421c7a4..dbbbdaf 100644
--- a/transport/Android.bp
+++ b/transport/Android.bp
@@ -80,5 +80,8 @@
         debuggable: {
             cflags: ["-DLIBHIDL_TARGET_DEBUGGABLE"],
         },
+        treble: {
+            cflags: ["-DLIBHIDL_TARGET_TREBLE"]
+        },
     },
 }
diff --git a/transport/HidlTransportSupport.cpp b/transport/HidlTransportSupport.cpp
index ea2e32c..0d2f1bf 100644
--- a/transport/HidlTransportSupport.cpp
+++ b/transport/HidlTransportSupport.cpp
@@ -14,7 +14,10 @@
  * limitations under the License.
  */
 #include <hidl/HidlTransportSupport.h>
+
+#include <android/hidl/manager/1.0/IServiceManager.h>
 #include <hidl/HidlBinderSupport.h>
+#include <hidl/ServiceManagement.h>
 
 namespace android {
 namespace hardware {
@@ -53,5 +56,116 @@
     return true;
 }
 
+namespace details {
+
+sp<::android::hidl::base::V1_0::IBase> getRawServiceInternal(const std::string& descriptor,
+                                                             const std::string& instance,
+                                                             bool retry, bool getStub) {
+    using Transport = ::android::hidl::manager::V1_0::IServiceManager::Transport;
+    using ::android::hidl::base::V1_0::IBase;
+    using ::android::hidl::manager::V1_0::IServiceManager;
+
+    const sp<IServiceManager> sm = defaultServiceManager();
+    if (sm == nullptr) {
+        ALOGE("getService: defaultServiceManager() is null");
+        return nullptr;
+    }
+
+    Return<Transport> transportRet = sm->getTransport(descriptor, instance);
+
+    if (!transportRet.isOk()) {
+        ALOGE("getService: defaultServiceManager()->getTransport returns %s",
+              transportRet.description().c_str());
+        return nullptr;
+    }
+    Transport transport = transportRet;
+    const bool vintfHwbinder = (transport == Transport::HWBINDER);
+    const bool vintfPassthru = (transport == Transport::PASSTHROUGH);
+
+#ifdef LIBHIDL_TARGET_TREBLE
+
+#ifdef LIBHIDL_TARGET_DEBUGGABLE
+    const char* env = std::getenv("TREBLE_TESTING_OVERRIDE");
+    const bool trebleTestingOverride = env && !strcmp(env, "true");
+    const bool vintfLegacy = (transport == Transport::EMPTY) && trebleTestingOverride;
+#else   // LIBHIDL_TARGET_TREBLE but not LIBHIDL_TARGET_DEBUGGABLE
+    const bool trebleTestingOverride = false;
+    const bool vintfLegacy = false;
+#endif  // LIBHIDL_TARGET_DEBUGGABLE
+
+#else   // not LIBHIDL_TARGET_TREBLE
+    const char* env = std::getenv("TREBLE_TESTING_OVERRIDE");
+    const bool trebleTestingOverride = env && !strcmp(env, "true");
+    const bool vintfLegacy = (transport == Transport::EMPTY);
+#endif  // LIBHIDL_TARGET_TREBLE
+
+    for (int tries = 0;
+         !getStub && (vintfHwbinder || (vintfLegacy && tries == 0)) && (retry || tries < 1);
+         tries++) {
+        if (tries > 1) {
+            ALOGI("getService: Will do try %d for %s/%s in 1s...", tries, descriptor.c_str(),
+                  instance.c_str());
+            sleep(1);  // TODO(b/67425500): remove and update waitForHwService function
+        }
+        if (vintfHwbinder && tries > 0) {
+            waitForHwService(descriptor, instance);
+        }
+        Return<sp<IBase>> ret = sm->get(descriptor, instance);
+        if (!ret.isOk()) {
+            ALOGE("getService: defaultServiceManager()->get returns %s for %s/%s.",
+                  ret.description().c_str(), descriptor.c_str(), instance.c_str());
+            break;
+        }
+        sp<IBase> base = ret;
+        if (base == nullptr) {
+            if (tries > 0) {
+                ALOGW("getService: found unexpected null hwbinder interface for %s/%s.",
+                      descriptor.c_str(), instance.c_str());
+            }
+            continue;
+        }
+
+        Return<bool> canCastRet =
+            details::canCastInterface(base.get(), descriptor.c_str(), true /* emitError */);
+
+        if (!canCastRet.isOk()) {
+            if (canCastRet.isDeadObject()) {
+                ALOGW("getService: found dead hwbinder service for %s/%s.", descriptor.c_str(),
+                      instance.c_str());
+                continue;
+            }
+            // TODO(b/67425500): breaks getService == nullptr => hal available assumptions if the
+            // service has a transaction failure (one example of this is if the service's binder
+            // buffer is full). If this isn't here, you get an infinite loop when you don't have
+            // permission to talk to a service.
+            ALOGW("getService: unable to call into hwbinder service for %s/%s.", descriptor.c_str(),
+                  instance.c_str());
+            break;
+        }
+
+        if (!canCastRet) {
+            ALOGW("getService: received incompatible service (bug in hwservicemanager?) for %s/%s.",
+                  descriptor.c_str(), instance.c_str());
+            break;
+        }
+
+        return base;  // still needs to be wrapped by Bp class.
+    }
+
+    if (getStub || vintfPassthru || vintfLegacy) {
+        const sp<IServiceManager> pm = getPassthroughServiceManager();
+        if (pm != nullptr) {
+            sp<IBase> base = pm->get(descriptor, instance).withDefault(nullptr);
+            if (!getStub || trebleTestingOverride) {
+                base = wrapPassthrough(base);
+            }
+            return base;
+        }
+    }
+
+    return nullptr;
 }
-}
+
+}  // namespace details
+}  // namespace hardware
+}  // namespace android
diff --git a/transport/include/hidl/HidlTransportSupport.h b/transport/include/hidl/HidlTransportSupport.h
index 18a4036..4c9a881 100644
--- a/transport/include/hidl/HidlTransportSupport.h
+++ b/transport/include/hidl/HidlTransportSupport.h
@@ -19,6 +19,7 @@
 
 #include <android/hidl/base/1.0/IBase.h>
 #include <hidl/HidlBinderSupport.h>
+#include <hidl/HidlPassthroughSupport.h>
 #include <hidl/HidlSupport.h>
 #include <hidl/HidlTransportUtils.h>
 
@@ -106,10 +107,40 @@
         // binderized mode. Got BpChild. grab the remote and wrap it.
         return sp<IChild>(new BpChild(toBinder<IParent>(parent)));
     }
-    // Passthrough mode. Got BnChild and BsChild.
+    // Passthrough mode. Got BnChild or BsChild.
     return sp<IChild>(static_cast<IChild *>(parent.get()));
 }
 
+// Returns a service with the following constraints:
+// - retry => service is waited for and returned if available in this process
+// - getStub => internal only. Forces to get the unwrapped (no BsFoo) if available.
+// TODO(b/65843592)
+// If the service is a remote service, this function returns BpBase. If the service is
+// a passthrough service, this function returns the appropriately wrapped Bs child object.
+sp<::android::hidl::base::V1_0::IBase> getRawServiceInternal(const std::string& descriptor,
+                                                             const std::string& instance,
+                                                             bool retry, bool getStub);
+
+template <typename BpType, typename IType = typename BpType::Pure,
+          typename = std::enable_if_t<std::is_same<i_tag, typename IType::_hidl_tag>::value>,
+          typename = std::enable_if_t<std::is_same<bphw_tag, typename BpType::_hidl_tag>::value>>
+sp<IType> getServiceInternal(const std::string& instance, bool retry, bool getStub) {
+    using ::android::hidl::base::V1_0::IBase;
+
+    sp<IBase> base = getRawServiceInternal(IType::descriptor, instance, retry, getStub);
+
+    if (base == nullptr) {
+        return nullptr;
+    }
+
+    if (base->isRemote()) {
+        // getRawServiceInternal guarantees we get the proper class
+        return sp<IType>(new BpType(toBinder<IBase>(base)));
+    }
+
+    return IType::castFrom(base);
+}
+
 }  // namespace details
 
 }  // namespace hardware