servicemanager: vintf declared API

servicemanager already has to parse VINTF configurations, so exposing
this functionality here (mirroring hwservicemanager).

Note, this API, like isDeclared is not branded as "VINTF" for future
compatibility with APEX or other interfaces.

Bug: 168715768
Test: manual
Change-Id: Ifbc44677605de757c46ef17f7f29fd83e66a8161

1 files changed, 74 insertions, 19 deletions

diff --git a/cmds/servicemanager/ServiceManager.cpp b/cmds/servicemanager/ServiceManager.cpp
index e80c3210f0..c8355e2b6b 100644
--- a/cmds/servicemanager/ServiceManager.cpp
+++ b/cmds/servicemanager/ServiceManager.cpp
@@ -37,6 +37,27 @@ using ::android::internal::Stability;
 namespace android {
 
 #ifndef VENDORSERVICEMANAGER
+struct ManifestWithDescription {
+    std::shared_ptr<const vintf::HalManifest> manifest;
+    const char* description;
+};
+// func true -> stop search and forEachManifest will return true
+static bool forEachManifest(const std::function<bool(const ManifestWithDescription&)>& func) {
+    for (const ManifestWithDescription& mwd : {
+            ManifestWithDescription{ vintf::VintfObject::GetDeviceHalManifest(), "device" },
+            ManifestWithDescription{ vintf::VintfObject::GetFrameworkHalManifest(), "framework" },
+        }) {
+        if (mwd.manifest == nullptr) {
+          LOG(ERROR) << "NULL VINTF MANIFEST!: " << mwd.description;
+          // note, we explicitly do not retry here, so that we can detect VINTF
+          // or other bugs (b/151696835)
+          continue;
+        }
+        if (func(mwd)) return true;
+    }
+    return false;
+}
+
 static bool isVintfDeclared(const std::string& name) {
     size_t firstSlash = name.find('/');
     size_t lastDot = name.rfind('.', firstSlash);
@@ -49,31 +70,41 @@ static bool isVintfDeclared(const std::string& name) {
     const std::string iface = name.substr(lastDot+1, firstSlash-lastDot-1);
     const std::string instance = name.substr(firstSlash+1);
 
-    struct ManifestWithDescription {
-        std::shared_ptr<const vintf::HalManifest> manifest;
-        const char* description;
-    };
-    for (const ManifestWithDescription& mwd : {
-            ManifestWithDescription{ vintf::VintfObject::GetDeviceHalManifest(), "device" },
-            ManifestWithDescription{ vintf::VintfObject::GetFrameworkHalManifest(), "framework" },
-        }) {
-        if (mwd.manifest == nullptr) {
-          LOG(ERROR) << "NULL VINTF MANIFEST!: " << mwd.description;
-          // note, we explicitly do not retry here, so that we can detect VINTF
-          // or other bugs (b/151696835)
-          continue;
-        }
+    bool found = forEachManifest([&] (const ManifestWithDescription& mwd) {
         if (mwd.manifest->hasAidlInstance(package, iface, instance)) {
             LOG(INFO) << "Found " << name << " in " << mwd.description << " VINTF manifest.";
             return true;
         }
+        return false;  // continue
+    });
+
+    if (!found) {
+        // Although it is tested, explicitly rebuilding qualified name, in case it
+        // becomes something unexpected.
+        LOG(ERROR) << "Could not find " << package << "." << iface << "/" << instance
+                   << " in the VINTF manifest.";
     }
 
-    // Although it is tested, explicitly rebuilding qualified name, in case it
-    // becomes something unexpected.
-    LOG(ERROR) << "Could not find " << package << "." << iface << "/" << instance
-               << " in the VINTF manifest.";
-    return false;
+    return found;
+}
+
+static std::vector<std::string> getVintfInstances(const std::string& interface) {
+    size_t lastDot = interface.rfind('.');
+    if (lastDot == std::string::npos) {
+        LOG(ERROR) << "VINTF interfaces require names in Java package format (e.g. some.package.foo.IFoo) but got: " << interface;
+        return {};
+    }
+    const std::string package = interface.substr(0, lastDot);
+    const std::string iface = interface.substr(lastDot+1);
+
+    std::vector<std::string> ret;
+    (void)forEachManifest([&](const ManifestWithDescription& mwd) {
+        auto instances = mwd.manifest->getAidlInstances(package, iface);
+        ret.insert(ret.end(), instances.begin(), instances.end());
+        return false;  // continue
+    });
+
+    return ret;
 }
 
 static bool meetsDeclarationRequirements(const sp<IBinder>& binder, const std::string& name) {
@@ -331,6 +362,30 @@ Status ServiceManager::isDeclared(const std::string& name, bool* outReturn) {
     return Status::ok();
 }
 
+binder::Status ServiceManager::getDeclaredInstances(const std::string& interface, std::vector<std::string>* outReturn) {
+    auto ctx = mAccess->getCallingContext();
+
+    std::vector<std::string> allInstances;
+#ifndef VENDORSERVICEMANAGER
+    allInstances = getVintfInstances(interface);
+#endif
+
+    outReturn->clear();
+
+    for (const std::string& instance : allInstances) {
+        // TODO(b/169275998): allow checking policy only once for the interface
+        if (mAccess->canFind(ctx, interface + "/" + instance)) {
+            outReturn->push_back(instance);
+        }
+    }
+
+    if (outReturn->size() == 0 && allInstances.size() != 0) {
+        return Status::fromExceptionCode(Status::EX_SECURITY);
+    }
+
+    return Status::ok();
+}
+
 void ServiceManager::removeRegistrationCallback(const wp<IBinder>& who,
                                     ServiceCallbackMap::iterator* it,
                                     bool* found) {