libbinder: RPC use 'status_t' over 'bool'

For ease of debugging/handling errors (I realized that binderRpcTest
currently crashes on Pixel 3 because of some missing kernel patches -
this would have been easier with this, and one potential (even if
temporary) solution would be to check the return code).

Bug: 167966510
Test: binderRpcTest, binderRpcBenchmark, binder_parcel_fuzzer,
    binder_rpc_fuzzer, binderHostDeviceTest
Change-Id: I1baa2e9380e0ec8f82f8ceb250f3eeb632dc5fbc
diff --git a/libs/binder/RpcServer.cpp b/libs/binder/RpcServer.cpp
index 879e462..4fa99c0 100644
--- a/libs/binder/RpcServer.cpp
+++ b/libs/binder/RpcServer.cpp
@@ -55,25 +55,25 @@
     mAgreedExperimental = true;
 }
 
-bool RpcServer::setupUnixDomainServer(const char* path) {
+status_t RpcServer::setupUnixDomainServer(const char* path) {
     return setupSocketServer(UnixSocketAddress(path));
 }
 
-bool RpcServer::setupVsockServer(unsigned int port) {
+status_t RpcServer::setupVsockServer(unsigned int port) {
     // realizing value w/ this type at compile time to avoid ubsan abort
     constexpr unsigned int kAnyCid = VMADDR_CID_ANY;
 
     return setupSocketServer(VsockSocketAddress(kAnyCid, port));
 }
 
-bool RpcServer::setupInetServer(const char* address, unsigned int port,
-                                unsigned int* assignedPort) {
+status_t RpcServer::setupInetServer(const char* address, unsigned int port,
+                                    unsigned int* assignedPort) {
     if (assignedPort != nullptr) *assignedPort = 0;
     auto aiStart = InetSocketAddress::getAddrInfo(address, port);
-    if (aiStart == nullptr) return false;
+    if (aiStart == nullptr) return UNKNOWN_ERROR;
     for (auto ai = aiStart.get(); ai != nullptr; ai = ai->ai_next) {
         InetSocketAddress socketAddress(ai->ai_addr, ai->ai_addrlen, address, port);
-        if (!setupSocketServer(socketAddress)) {
+        if (status_t status = setupSocketServer(socketAddress); status != OK) {
             continue;
         }
 
@@ -84,7 +84,7 @@
             int savedErrno = errno;
             ALOGE("Could not getsockname at %s: %s", socketAddress.toString().c_str(),
                   strerror(savedErrno));
-            return false;
+            return -savedErrno;
         }
         LOG_ALWAYS_FATAL_IF(len != sizeof(addr), "Wrong socket type: len %zu vs len %zu",
                             static_cast<size_t>(len), sizeof(addr));
@@ -97,11 +97,11 @@
             *assignedPort = realPort;
         }
 
-        return true;
+        return OK;
     }
     ALOGE("None of the socket address resolved for %s:%u can be set up as inet server.", address,
           port);
-    return false;
+    return UNKNOWN_ERROR;
 }
 
 void RpcServer::setMaxThreads(size_t threads) {
@@ -366,7 +366,7 @@
         }
 
         if (incoming) {
-            LOG_ALWAYS_FATAL_IF(!session->addOutgoingConnection(std::move(client), true),
+            LOG_ALWAYS_FATAL_IF(OK != session->addOutgoingConnection(std::move(client), true),
                                 "server state must already be initialized");
             return;
         }
@@ -383,21 +383,22 @@
     RpcSession::join(std::move(session), std::move(setupResult));
 }
 
-bool RpcServer::setupSocketServer(const RpcSocketAddress& addr) {
+status_t RpcServer::setupSocketServer(const RpcSocketAddress& addr) {
     LOG_RPC_DETAIL("Setting up socket server %s", addr.toString().c_str());
     LOG_ALWAYS_FATAL_IF(hasServer(), "Each RpcServer can only have one server.");
 
     unique_fd serverFd(
             TEMP_FAILURE_RETRY(socket(addr.addr()->sa_family, SOCK_STREAM | SOCK_CLOEXEC, 0)));
     if (serverFd == -1) {
-        ALOGE("Could not create socket: %s", strerror(errno));
-        return false;
+        int savedErrno = errno;
+        ALOGE("Could not create socket: %s", strerror(savedErrno));
+        return -savedErrno;
     }
 
     if (0 != TEMP_FAILURE_RETRY(bind(serverFd.get(), addr.addr(), addr.addrSize()))) {
         int savedErrno = errno;
         ALOGE("Could not bind socket at %s: %s", addr.toString().c_str(), strerror(savedErrno));
-        return false;
+        return -savedErrno;
     }
 
     // Right now, we create all threads at once, making accept4 slow. To avoid hanging the client,
@@ -407,16 +408,16 @@
     if (0 != TEMP_FAILURE_RETRY(listen(serverFd.get(), 50 /*backlog*/))) {
         int savedErrno = errno;
         ALOGE("Could not listen socket at %s: %s", addr.toString().c_str(), strerror(savedErrno));
-        return false;
+        return -savedErrno;
     }
 
     LOG_RPC_DETAIL("Successfully setup socket server %s", addr.toString().c_str());
 
-    if (!setupExternalServer(std::move(serverFd))) {
+    if (status_t status = setupExternalServer(std::move(serverFd)); status != OK) {
         ALOGE("Another thread has set up server while calling setupSocketServer. Race?");
-        return false;
+        return status;
     }
-    return true;
+    return OK;
 }
 
 void RpcServer::onSessionAllIncomingThreadsEnded(const sp<RpcSession>& session) {
@@ -449,15 +450,15 @@
     return std::move(mServer);
 }
 
-bool RpcServer::setupExternalServer(base::unique_fd serverFd) {
+status_t RpcServer::setupExternalServer(base::unique_fd serverFd) {
     LOG_ALWAYS_FATAL_IF(!mAgreedExperimental, "no!");
     std::lock_guard<std::mutex> _l(mLock);
     if (mServer.ok()) {
         ALOGE("Each RpcServer can only have one server.");
-        return false;
+        return INVALID_OPERATION;
     }
     mServer = std::move(serverFd);
-    return true;
+    return OK;
 }
 
 } // namespace android