5 files changed, 20 insertions, 13 deletions

diff --git a/src/OSSupport/HostnameLookup.cpp b/src/OSSupport/HostnameLookup.cpp
index 860e0d88f..3a2997ffd 100644
--- a/src/OSSupport/HostnameLookup.cpp
+++ b/src/OSSupport/HostnameLookup.cpp
@@ -53,7 +53,7 @@ void cHostnameLookup::Callback(int a_ErrCode, evutil_addrinfo * a_Addr, void * a
 	// If an error has occurred, notify the error callback:
 	if (a_ErrCode != 0)
 	{
-		Self->m_Callbacks->OnError(a_ErrCode);
+		Self->m_Callbacks->OnError(a_ErrCode, evutil_socket_error_to_string(a_ErrCode));
 		cNetworkSingleton::Get().RemoveHostnameLookup(Self);
 		return;
 	}
@@ -91,7 +91,7 @@ void cHostnameLookup::Callback(int a_ErrCode, evutil_addrinfo * a_Addr, void * a
 	// If only unsupported families were reported, call the Error handler:
 	if (!HasResolved)
 	{
-		Self->m_Callbacks->OnError(DNS_ERR_NODATA);
+		Self->m_Callbacks->OnError(DNS_ERR_NODATA, "The name does not resolve to any known address.");
 	}
 	else
 	{
diff --git a/src/OSSupport/IPLookup.cpp b/src/OSSupport/IPLookup.cpp
index a52b6480b..8cdc5132d 100644
--- a/src/OSSupport/IPLookup.cpp
+++ b/src/OSSupport/IPLookup.cpp
@@ -78,7 +78,7 @@ void cIPLookup::Callback(int a_Result, char a_Type, int a_Count, int a_Ttl, void
 	if ((a_Result != 0) || (a_Addresses == nullptr))
 	{
 		// An error has occurred, notify the error callback:
-		Self->m_Callbacks->OnError(a_Result);
+		Self->m_Callbacks->OnError(a_Result, evutil_socket_error_to_string(a_Result));
 	}
 	else
 	{
diff --git a/src/OSSupport/Network.h b/src/OSSupport/Network.h
index 0452c3b6a..3ed9885ec 100644
--- a/src/OSSupport/Network.h
+++ b/src/OSSupport/Network.h
@@ -34,7 +34,7 @@ public:
 		virtual void OnRemoteClosed(cTCPLink & a_Link) = 0;
 
 		/** Called when an error is detected on the connection. */
-		virtual void OnError(cTCPLink & a_Link, int a_ErrorCode) = 0;
+		virtual void OnError(cTCPLink & a_Link, int a_ErrorCode, const AString & a_ErrorMsg) = 0;
 	};
 	typedef SharedPtr<cCallbacks> cCallbacksPtr;
 
@@ -127,7 +127,7 @@ public:
 		virtual void OnSuccess(cTCPLink & a_Link) = 0;
 
 		/** Called when the Connect call fails. */
-		virtual void OnError(int a_ErrorCode) = 0;
+		virtual void OnError(int a_ErrorCode, const AString & a_ErrorMsg) = 0;
 	};
 	typedef SharedPtr<cConnectCallbacks> cConnectCallbacksPtr;
 
@@ -163,7 +163,7 @@ public:
 
 		/** Called when an error is encountered while resolving.
 		If an error is reported, the OnFinished() callback is not called. */
-		virtual void OnError(int a_ErrorCode) = 0;
+		virtual void OnError(int a_ErrorCode, const AString & a_ErrorMsg) = 0;
 
 		/** Called when all the addresses resolved have been reported via the OnNameResolved() callback.
 		Only called if there was no error reported. */
diff --git a/src/OSSupport/ServerHandleImpl.cpp b/src/OSSupport/ServerHandleImpl.cpp
index 866aa01be..d81d4ba46 100644
--- a/src/OSSupport/ServerHandleImpl.cpp
+++ b/src/OSSupport/ServerHandleImpl.cpp
@@ -173,7 +173,7 @@ bool cServerHandleImpl::Listen(UInt16 a_Port)
 		if (bind(MainSock, reinterpret_cast<const sockaddr *>(&name), sizeof(name)) != 0)
 		{
 			m_ErrorCode = EVUTIL_SOCKET_ERROR();
-			Printf(m_ErrorMsg, "Cannot bind IPv6 socket to port %d: %s", a_Port, evutil_socket_error_to_string(m_ErrorCode));
+			Printf(m_ErrorMsg, "Cannot bind IPv6 socket to port %d: %d (%s)", a_Port, m_ErrorCode, evutil_socket_error_to_string(m_ErrorCode));
 			evutil_closesocket(MainSock);
 			return false;
 		}
@@ -181,14 +181,14 @@ bool cServerHandleImpl::Listen(UInt16 a_Port)
 	if (evutil_make_socket_nonblocking(MainSock) != 0)
 	{
 		m_ErrorCode = EVUTIL_SOCKET_ERROR();
-		Printf(m_ErrorMsg, "Cannot make socket on port %d non-blocking: %s", a_Port, evutil_socket_error_to_string(m_ErrorCode));
+		Printf(m_ErrorMsg, "Cannot make socket on port %d non-blocking: %d (%s)", a_Port, m_ErrorCode, evutil_socket_error_to_string(m_ErrorCode));
 		evutil_closesocket(MainSock);
 		return false;
 	}
 	if (listen(MainSock, 0) != 0)
 	{
 		m_ErrorCode = EVUTIL_SOCKET_ERROR();
-		Printf(m_ErrorMsg, "Cannot listen on port %d: %s", a_Port, evutil_socket_error_to_string(m_ErrorCode));
+		Printf(m_ErrorMsg, "Cannot listen on port %d: %d (%s)", a_Port, m_ErrorCode, evutil_socket_error_to_string(m_ErrorCode));
 		evutil_closesocket(MainSock);
 		return false;
 	}
@@ -215,6 +215,7 @@ bool cServerHandleImpl::Listen(UInt16 a_Port)
 		err = EVUTIL_SOCKET_ERROR();
 		LOGD("evutil_make_socket_nonblocking() failed for secondary socket: %d, %s", err, evutil_socket_error_to_string(err));
 		evutil_closesocket(SecondSock);
+		return true;  // Report as success, the primary socket is working
 	}
 
 	// Bind to all IPv4 interfaces:
@@ -227,7 +228,7 @@ bool cServerHandleImpl::Listen(UInt16 a_Port)
 		err = EVUTIL_SOCKET_ERROR();
 		LOGD("Cannot bind secondary socket to port %d: %d (%s)", a_Port, err, evutil_socket_error_to_string(err));
 		evutil_closesocket(SecondSock);
-		return true;
+		return true;  // Report as success, the primary socket is working
 	}
 
 	if (listen(SecondSock, 0) != 0)
@@ -235,7 +236,7 @@ bool cServerHandleImpl::Listen(UInt16 a_Port)
 		err = EVUTIL_SOCKET_ERROR();
 		LOGD("Cannot listen on on secondary socket on port %d: %d (%s)", a_Port, err, evutil_socket_error_to_string(err));
 		evutil_closesocket(SecondSock);
-		return false;
+		return true;  // Report as success, the primary socket is working
 	}
 
 	m_SecondaryConnListener = evconnlistener_new(cNetworkSingleton::Get().GetEventBase(), Callback, this, LEV_OPT_CLOSE_ON_FREE | LEV_OPT_REUSEABLE, 0, SecondSock);
diff --git a/src/OSSupport/TCPLinkImpl.cpp b/src/OSSupport/TCPLinkImpl.cpp
index 3c0775367..f87f68280 100644
--- a/src/OSSupport/TCPLinkImpl.cpp
+++ b/src/OSSupport/TCPLinkImpl.cpp
@@ -177,13 +177,19 @@ void cTCPLinkImpl::EventCallback(bufferevent * a_BufferEvent, short a_What, void
 	if (a_What & BEV_EVENT_ERROR)
 	{
 		// Choose the proper callback to call based on whether we were waiting for connection or not:
+		int err = EVUTIL_SOCKET_ERROR();
 		if (Self->m_ConnectCallbacks != nullptr)
 		{
-			Self->m_ConnectCallbacks->OnError(EVUTIL_SOCKET_ERROR());
+			if (err == 0)
+			{
+				// This could be a DNS failure
+				err = bufferevent_socket_get_dns_error(a_BufferEvent);
+			}
+			Self->m_ConnectCallbacks->OnError(err, evutil_socket_error_to_string(err));
 		}
 		else
 		{
-			Self->m_Callbacks->OnError(*Self, EVUTIL_SOCKET_ERROR());
+			Self->m_Callbacks->OnError(*Self, err, evutil_socket_error_to_string(err));
 			if (Self->m_Server == nullptr)
 			{
 				cNetworkSingleton::Get().RemoveLink(Self);