libbinder: remove abstraction layer for get port

In preparation to move this code to another file. There were a few
bugs before:
- dead code
- getsockaddr error would lead to abort (but only inconsistent state in
  the old abstraction should have left for an abort)
- added check to ensure socklen_t when returned from getsockname is as
  expected

Bug: 185167543
Test: binderRpcTest
Change-Id: Ic79479b6a66226db309dfde134617af50c2365fe

1 files changed, 18 insertions, 52 deletions

diff --git a/libs/binder/RpcConnection.cpp b/libs/binder/RpcConnection.cpp
index fa228b2ab3..3e1964673a 100644
--- a/libs/binder/RpcConnection.cpp
+++ b/libs/binder/RpcConnection.cpp
@@ -46,55 +46,9 @@ extern "C" pid_t gettid();
 
 namespace android {
 
-using base::borrowed_fd;
 using base::unique_fd;
 using AddrInfo = std::unique_ptr<addrinfo, decltype(&freeaddrinfo)>;
 
-namespace {
-bool checkSockaddrSize(const char* name, size_t actual, size_t expected) {
-    if (actual >= expected) return true;
-    ALOGW("getSockaddrPort: family is %s but size is %zu < %zu", name, actual, expected);
-    return false;
-}
-
-// Get the port number of |storage| for certain families. Requires storage->sa_family to be
-// set to a known family; otherwise, return nullopt.
-std::optional<unsigned int> getSockaddrPort(const sockaddr* storage, socklen_t len) {
-    switch (storage->sa_family) {
-        case AF_INET: {
-            if (!checkSockaddrSize("INET", len, sizeof(sockaddr_in))) return std::nullopt;
-            auto inetStorage = reinterpret_cast<const sockaddr_in*>(storage);
-            return ntohs(inetStorage->sin_port);
-        }
-        default: {
-            uint16_t family = storage->sa_family;
-            ALOGW("Don't know how to infer port for family %" PRIu16, family);
-            return std::nullopt;
-        }
-    }
-}
-
-std::optional<unsigned int> getSocketPort(borrowed_fd socketfd,
-                                          const RpcConnection::SocketAddress& socketAddress) {
-    sockaddr_storage storage{};
-    socklen_t len = sizeof(storage);
-    auto storagePtr = reinterpret_cast<sockaddr*>(&storage);
-    if (0 != getsockname(socketfd.get(), storagePtr, &len)) {
-        int savedErrno = errno;
-        ALOGE("Could not getsockname at %s: %s", socketAddress.toString().c_str(),
-              strerror(savedErrno));
-        return std::nullopt;
-    }
-
-    // getsockname does not fill in family, but getSockaddrPort() needs it.
-    if (storage.ss_family == AF_UNSPEC) {
-        storage.ss_family = socketAddress.addr()->sa_family;
-    }
-    return getSockaddrPort(storagePtr, len);
-}
-
-} // namespace
-
 RpcConnection::SocketAddress::~SocketAddress() {}
 
 RpcConnection::RpcConnection() {
@@ -224,15 +178,27 @@ bool RpcConnection::setupInetServer(unsigned int port, unsigned int* assignedPor
         if (!setupSocketServer(socketAddress)) {
             continue;
         }
-        auto realPort = getSocketPort(mServer.get(), socketAddress);
-        LOG_ALWAYS_FATAL_IF(!realPort.has_value(), "Unable to get port number after setting up %s",
-                            socketAddress.toString().c_str());
-        LOG_ALWAYS_FATAL_IF(port != 0 && *realPort != port,
+
+        LOG_ALWAYS_FATAL_IF(socketAddress.addr()->sa_family != AF_INET, "expecting inet");
+        sockaddr_in addr{};
+        socklen_t len = sizeof(addr);
+        if (0 != getsockname(mServer.get(), reinterpret_cast<sockaddr*>(&addr), &len)) {
+            int savedErrno = errno;
+            ALOGE("Could not getsockname at %s: %s", socketAddress.toString().c_str(),
+                  strerror(savedErrno));
+            return false;
+        }
+        LOG_ALWAYS_FATAL_IF(len != sizeof(addr), "Wrong socket type: len %zu vs len %zu",
+                            static_cast<size_t>(len), sizeof(addr));
+        unsigned int realPort = ntohs(addr.sin_port);
+        LOG_ALWAYS_FATAL_IF(port != 0 && realPort != port,
                             "Requesting inet server on %s but it is set up on %u.",
-                            socketAddress.toString().c_str(), *realPort);
+                            socketAddress.toString().c_str(), realPort);
+
         if (assignedPort != nullptr) {
-            *assignedPort = *realPort;
+            *assignedPort = realPort;
         }
+
         return true;
     }
     ALOGE("None of the socket address resolved for %s:%u can be set up as inet server.", kAddr,