net: add socketpair wrapper.

Useful to have a Unix socket-pair to communicate with
a forked process.

Signed-off-by: Michael Meeks <michael.meeks@collabora.com>
Change-Id: Ic4ad1eee62b6d3b40a03bc8e59bce6e0e16efc28

net/Socket.cpp

@@ -80,6 +80,26 @@ int Socket::createSocket([[maybe_unused]] Socket::Type type)
 #endif
 }
 
+
+bool StreamSocket::socketpair(std::shared_ptr<StreamSocket> &parent,
+                              std::shared_ptr<StreamSocket> &child)
+{
+#if MOBILEAPP
+    return false;
+#else
+    int pair[2];
+    int rc = ::socketpair(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0, pair);
+    if (rc != 0)
+        return false;
+
+    child = std::shared_ptr<StreamSocket>(new StreamSocket("save-child", pair[0], Socket::Type::Unix, true));
+    parent = std::shared_ptr<StreamSocket>(new StreamSocket("save-kit-parent", pair[1], Socket::Type::Unix, true));
+
+    return true;
+#endif
+}
+
+
 #if ENABLE_DEBUG
 static std::atomic<long> socketErrorCount;
 

net/Socket.hpp

@@ -926,11 +926,9 @@ public:
 
     /// Create a StreamSocket from native FD.
     StreamSocket(std::string host, const int fd, Type type, bool /* isClient */,
-                 std::shared_ptr<ProtocolHandlerInterface> socketHandler,
                  ReadType readType = NormalRead) :
         Socket(fd, type),
         _hostname(std::move(host)),
-        _socketHandler(std::move(socketHandler)),
         _bytesSent(0),
         _bytesRecvd(0),
         _wsState(WSState::HTTP),
@@ -941,11 +939,6 @@ public:
         _inputProcessingEnabled(true)
     {
         LOG_TRC("StreamSocket ctor");
-
-        // Without a handler we make no sense object.
-        if (!_socketHandler)
-            throw std::runtime_error("StreamSocket " + std::to_string(fd) +
-                                     " expects a valid SocketHandler instance.");
     }
 
     ~StreamSocket()
@@ -956,7 +949,8 @@ public:
         if (!_closed)
         {
             ASSERT_CORRECT_SOCKET_THREAD(this);
-            _socketHandler->onDisconnect();
+            if (_socketHandler)
+                _socketHandler->onDisconnect();
             _socketHandler.reset();
         }
 
@@ -1009,6 +1003,10 @@ public:
         return !_outBuffer.empty() || !_inBuffer.empty();
     }
 
+    /// Create a pair of connected stream sockets
+    static bool socketpair(std::shared_ptr<StreamSocket> &parent,
+                           std::shared_ptr<StreamSocket> &child);
+
     /// Send data to the socket peer.
     void send(const char* data, const int len, const bool doFlush = true)
     {
@@ -1202,10 +1200,14 @@ public:
                                            std::shared_ptr<ProtocolHandlerInterface> handler,
                                            ReadType readType = NormalRead)
     {
-        ProtocolHandlerInterface* pHandler = handler.get();
-        auto socket = std::make_shared<TSocket>(std::move(hostname), fd, type, isClient,
-                                                std::move(handler), readType);
-        pHandler->onConnect(socket);
+        // Without a handler we make no sense object.
+        if (!handler)
+            throw std::runtime_error("StreamSocket " + std::to_string(fd) +
+                                     " expects a valid SocketHandler instance.");
+
+        auto socket = std::make_shared<TSocket>(std::move(hostname), fd, type, isClient, readType);
+        socket->setHandler(handler);
+
         return socket;
     }
 

net/SslSocket.hpp

@@ -24,9 +24,8 @@ class SslStreamSocket final : public StreamSocket
 {
 public:
     SslStreamSocket(const std::string& host, const int fd, Type type, bool isClient,
-                    std::shared_ptr<ProtocolHandlerInterface> responseClient,
                     ReadType readType = NormalRead)
-        : StreamSocket(host, fd, type, isClient, std::move(responseClient), readType)
+        : StreamSocket(host, fd, type, isClient, readType)
         , _bio(nullptr)
         , _ssl(nullptr)
         , _sslWantsTo(SslWantsTo::Neither)