/// <summary>
/// Gets the coap request. Creates the CoAP request from the HTTP method and
/// mapping it through the properties file. The uri is translated using
/// regular expressions, the uri format expected is either the embedded
/// mapping (http://proxyname.domain:80/proxy/coapserver:5683/resource
/// converted in coap://coapserver:5683/resource) or the standard uri to
/// indicate a local request not to be forwarded. The method uses a decoder
/// to translate the application/x-www-form-urlencoded format of the uri. The
/// CoAP options are set translating the headers. If the HTTP message has an
/// enclosing entity, it is converted to create the payload of the CoAP
/// message; finally the content-type is set accordingly to the header and to
/// the entity type.
/// </summary>
/// <param name="httpRequest">the http request</param>
/// <param name="proxyResource"></param>
/// <param name="proxyingEnabled"></param>
/// <returns></returns>
public static Request GetCoapRequest(IHttpRequest httpRequest, String proxyResource, Boolean proxyingEnabled)
{
if (httpRequest == null)
throw ThrowHelper.ArgumentNull("httpRequest");
if (proxyResource == null)
throw ThrowHelper.ArgumentNull("proxyResource");
Method coapMethod;
if (!http2coapMethod.TryGetValue(httpRequest.Method, out coapMethod))
throw ThrowHelper.TranslationException(httpRequest.Method + " method not mapped");
// create the request
Request coapRequest = new Request(coapMethod);
// get the uri
String uriString = httpRequest.RequestUri;
// remove the initial "/"
if (uriString.StartsWith("/"))
uriString = uriString.Substring(1);
// TODO URLDecode
// if the uri contains the proxy resource name, the request should be
// forwarded and it is needed to get the real requested coap server's
// uri
// e.g.:
// /proxy/[::1]:5684/helloWorld
// proxy resource: /proxy
// coap server: [::1]:5684
// coap resource: helloWorld
Regex regex = new Regex(".?" + proxyResource + ".*");
if (regex.IsMatch(uriString))
{
// find the first occurrence of the proxy resource
Int32 index = uriString.IndexOf(proxyResource);
// delete the slash
index = uriString.IndexOf('/', index);
uriString = uriString.Substring(index + 1);
if (proxyingEnabled)
{
// if the uri hasn't the indication of the scheme, add it
if (!uriString.StartsWith("coap://") &&
!uriString.StartsWith("coaps://"))
{
uriString = "coap://" + uriString;
}
// the uri will be set as a proxy-uri option
// set the proxy-uri option to allow the lower layers to underes
coapRequest.SetOption(Option.Create(OptionType.ProxyUri, uriString));
}
else
{
coapRequest.URI = new Uri(uriString);
}
// TODO set the proxy as the sender to receive the response correctly
//coapRequest.PeerAddress = new EndpointAddress(IPAddress.Loopback);
}
else
{
// if the uri does not contains the proxy resource, it means the
// request is local to the proxy and it shouldn't be forwarded
// set the uri string as uri-path option
coapRequest.UriPath = uriString;
}
// translate the http headers in coap options
IEnumerable<Option> coapOptions = GetCoapOptions(httpRequest.Headers);
coapRequest.SetOptions(coapOptions);
// the payload
if (httpRequest.InputStream != null)
{
Byte[] tmp = new Byte[4096];
MemoryStream ms = new MemoryStream(tmp.Length);
Int32 read;
while ((read = httpRequest.InputStream.Read(tmp, 0, tmp.Length)) > 0)
{
ms.Write(tmp, 0, read);
}
coapRequest.Payload = ms.ToArray();
coapRequest.ContentType = GetCoapMediaType(httpRequest.Headers["content-type"]);
}
return coapRequest;
}
