Add a socket options callback to enable setting TCP keepalive

CONTRIBUTORS.txt

@@ -57,3 +57,4 @@ René Meusel (reneme)
 
 Sony Corporation
 Gareth Sylvester-Bradley (garethsb-sony)
+Simon Lo (lo-simon)

Release/include/cpprest/http_listener.h

@@ -18,6 +18,7 @@
 #include <limits>
 #if !defined(_WIN32) && !defined(__cplusplus_winrt) || defined(CPPREST_FORCE_HTTP_LISTENER_ASIO)
 #include <boost/asio/ssl.hpp>
+#include <boost/asio.hpp>
 #endif
 
 #if !defined(_WIN32) || (_WIN32_WINNT >= _WIN32_WINNT_VISTA && !defined(__cplusplus_winrt)) ||                         \
@@ -53,6 +54,7 @@ class http_listener_config
         , m_backlog(other.m_backlog)
 #if !defined(_WIN32) || defined(CPPREST_FORCE_HTTP_LISTENER_ASIO)
         , m_ssl_context_callback(other.m_ssl_context_callback)
+        , m_tcp_socket_callback(other.m_tcp_socket_callback)
 #endif
     {
     }
@@ -66,6 +68,7 @@ class http_listener_config
         , m_backlog(std::move(other.m_backlog))
 #if !defined(_WIN32) || defined(CPPREST_FORCE_HTTP_LISTENER_ASIO)
         , m_ssl_context_callback(std::move(other.m_ssl_context_callback))
+        , m_tcp_socket_callback(std::move(other.m_tcp_socket_callback))
 #endif
     {
     }
@@ -82,6 +85,7 @@ class http_listener_config
             m_backlog = rhs.m_backlog;
 #if !defined(_WIN32) || defined(CPPREST_FORCE_HTTP_LISTENER_ASIO)
             m_ssl_context_callback = rhs.m_ssl_context_callback;
+            m_tcp_socket_callback = rhs.m_tcp_socket_callback;
 #endif
         }
         return *this;
@@ -99,6 +103,7 @@ class http_listener_config
             m_backlog = std::move(rhs.m_backlog);
 #if !defined(_WIN32) || defined(CPPREST_FORCE_HTTP_LISTENER_ASIO)
             m_ssl_context_callback = std::move(rhs.m_ssl_context_callback);
+            m_tcp_socket_callback = std::move(rhs.m_tcp_socket_callback);
 #endif
         }
         return *this;
@@ -149,13 +154,33 @@ class http_listener_config
     {
         m_ssl_context_callback = ssl_context_callback;
     }
+
+    /// <summary>
+    /// Get the callback of tcp socket
+    /// </summary>
+    /// <returns>The function defined by the user of http_listener_config to configure a tcp socket.</returns>
+    const std::function<void(boost::asio::ip::tcp::socket&)>& get_tcp_socket_callback() const
+    {
+        return m_tcp_socket_callback;
+    }
+
+    /// <summary>
+    /// Set the callback of tcp socket
+    /// </summary>
+    /// <param name="socket_callback">The function to configure a tcp socket which will setup https
+    /// connections.</param>
+    void set_tcp_socket_callback(const std::function<void(boost::asio::ip::tcp::socket&)>& tcp_socket_callback)
+    {
+        m_tcp_socket_callback = tcp_socket_callback;
+    }
 #endif
 
 private:
     utility::seconds m_timeout;
     int m_backlog;
 #if !defined(_WIN32) || defined(CPPREST_FORCE_HTTP_LISTENER_ASIO)
     std::function<void(boost::asio::ssl::context&)> m_ssl_context_callback;
+    std::function<void(boost::asio::ip::tcp::socket&)> m_tcp_socket_callback;
 #endif
 };
 

Release/src/http/listener/http_server_asio.cpp

@@ -135,6 +135,7 @@ class hostport_listener
 
     bool m_is_https;
     const std::function<void(boost::asio::ssl::context&)>& m_ssl_context_callback;
+    const std::function<void(boost::asio::ip::tcp::socket&)>& m_tcp_socket_callback;
 
 public:
     hostport_listener(http_linux_server* server,
@@ -150,6 +151,7 @@ class hostport_listener
         , m_p_server(server)
         , m_is_https(is_https)
         , m_ssl_context_callback(config.get_ssl_context_callback())
+        , m_tcp_socket_callback(config.get_tcp_socket_callback())
     {
         m_all_connections_complete.set();
 
@@ -597,6 +599,11 @@ void hostport_listener::on_accept(std::unique_ptr<ip::tcp::socket> socket, const
         boost::system::error_code error_ignored;
         socket->set_option(option, error_ignored);
 
+        if (m_tcp_socket_callback)
+        {
+            m_tcp_socket_callback(*socket);
+        }
+
         auto conn = asio_server_connection::create(std::move(socket), m_p_server, this);
 
         m_connections.insert(conn.get());