[wpinet] ParallelTcpConnector: Add option to resolve only IPv4 addresses (#7194)

Author: PeterJohnson

wpinet/src/main/native/cpp/ParallelTcpConnector.cpp

@@ -24,10 +24,11 @@ using namespace wpi;
 ParallelTcpConnector::ParallelTcpConnector(
     wpi::uv::Loop& loop, wpi::uv::Timer::Time reconnectRate,
     wpi::Logger& logger, std::function<void(wpi::uv::Tcp& tcp)> connected,
-    const private_init&)
+    bool ipv4Only, const private_init&)
     : m_loop{loop},
       m_logger{logger},
       m_reconnectRate{reconnectRate},
+      m_ipv4Only{ipv4Only},
       m_connected{std::move(connected)},
       m_reconnectTimer{uv::Timer::Create(loop)} {
   if (!m_reconnectTimer) {
@@ -193,7 +194,7 @@ void ParallelTcpConnector::Connect() {
                static_cast<void*>(req.get()), server.first, server.second);
     addrinfo hints;
     std::memset(&hints, 0, sizeof(hints));
-    hints.ai_family = AF_UNSPEC;
+    hints.ai_family = m_ipv4Only ? AF_INET : AF_UNSPEC;
     hints.ai_socktype = SOCK_STREAM;
     hints.ai_protocol = IPPROTO_TCP;
     hints.ai_flags = AI_NUMERICSERV | AI_ADDRCONFIG;

wpinet/src/main/native/include/wpinet/ParallelTcpConnector.h

@@ -54,22 +54,26 @@ class ParallelTcpConnector
    * @param connected callback function when a connection succeeds; may be
    *                  called multiple times if it does not call Succeeded()
    *                  before returning
+   * @param ipv4Only true if only IPv4 addresses should be returned; otherwise
+   *                 both IPv4 and IPv6 addresses are returned
    * @return Parallel connector
    */
   static std::shared_ptr<ParallelTcpConnector> Create(
       wpi::uv::Loop& loop, wpi::uv::Timer::Time reconnectRate,
-      wpi::Logger& logger, std::function<void(wpi::uv::Tcp& tcp)> connected) {
+      wpi::Logger& logger, std::function<void(wpi::uv::Tcp& tcp)> connected,
+      bool ipv4Only = false) {
     if (loop.IsClosing()) {
       return nullptr;
     }
-    return std::make_shared<ParallelTcpConnector>(
-        loop, reconnectRate, logger, std::move(connected), private_init{});
+    return std::make_shared<ParallelTcpConnector>(loop, reconnectRate, logger,
+                                                  std::move(connected),
+                                                  ipv4Only, private_init{});
   }
 
   ParallelTcpConnector(wpi::uv::Loop& loop, wpi::uv::Timer::Time reconnectRate,
                        wpi::Logger& logger,
                        std::function<void(wpi::uv::Tcp& tcp)> connected,
-                       const private_init&);
+                       bool ipv4Only, const private_init&);
   ~ParallelTcpConnector();
 
   ParallelTcpConnector(const ParallelTcpConnector&) = delete;
@@ -111,6 +115,7 @@ class ParallelTcpConnector
   wpi::uv::Loop& m_loop;
   wpi::Logger& m_logger;
   wpi::uv::Timer::Time m_reconnectRate;
+  bool m_ipv4Only;
   std::function<void(wpi::uv::Tcp& tcp)> m_connected;
   std::shared_ptr<wpi::uv::Timer> m_reconnectTimer;
   std::vector<std::pair<std::string, unsigned int>> m_servers;