private void Communicate()
{
// communicate
try {
Communication.Communicate(this);
} catch (Exception exception) {
LogError($"Error: {exception.Message}");
// continue
} finally {
LogVerbose("Communication completed.");
lock (this.instanceLocker) {
CloseTcpConnections();
this.proxyCredential = null;
this.connectingToProxy = false;
this.responseIO = null;
this.requestIO = null;
}
}
return;
}
protected virtual bool SetModifications(Request request, Response response)
{
// argument checks
if (request == null)
{
throw new ArgumentNullException(nameof(request));
}
// response may be null
// Currently only basic authorization for the proxy is handled.
// ToDo: convert local function in C# 7
Func <bool, string, Proxy.BasicCredential> getServerBasicCredentials = (firstRequest, realm) => {
// set the cached proxy credential
Proxy.BasicCredential proxyCredential;
lock (this.instanceLocker) {
Proxy.BasicCredential currentProxyCredential = this.proxyCredential;
proxyCredential = firstRequest ? currentProxyCredential : null;
if (proxyCredential == null)
{
string endPoint = this.server.EndPoint;
proxyCredential = this.Proxy.GetServerBasicCredentials(endPoint, realm, firstRequest: firstRequest, oldBasicCredentials: currentProxyCredential);
this.proxyCredential = proxyCredential; // may be null
}
}
return(proxyCredential);
};
bool retry = false;
IReadOnlyCollection <byte> overridingProxyAuthorization = null;
if (response == null)
{
// before requesting firstly
if (request.ProxyAuthorizationSpan.IsZeroToZero)
{
// set the cached proxy credential
Proxy.BasicCredential proxyCredential = getServerBasicCredentials(true, null);
overridingProxyAuthorization = proxyCredential?.Bytes;
}
}
else
{
// after responded from the server
if (response.StatusCode == 407)
{
// 407: Proxy Authentication Required
// the current credential seems to be invalid (or null)
Proxy.BasicCredential proxyCredential = getServerBasicCredentials(false, "Proxy"); // ToDo: extract realm from the field
overridingProxyAuthorization = proxyCredential?.Bytes;
}
else
{
// no need to resending
overridingProxyAuthorization = null;
}
}
// set modifications if necessary
if (overridingProxyAuthorization != null)
{
// set or overwrite the Proxy-Authorization field.
Span span = request.ProxyAuthorizationSpan;
if (span.IsZeroToZero)
{
span = request.EndOfHeaderFields;
}
request.AddModification(
span,
(modifier) => { modifier.Write(overridingProxyAuthorization); return(true); }
);
retry = true;
}
return(retry);
}