/// <summary>
/// Raises <b>AorUpdated</b> event.
/// </summary>
/// <param name="registration">SIP registration.</param>
private void OnAorUpdated(SIP_Registration registration)
{
if (this.AorUpdated != null)
{
this.AorUpdated(this, new SIP_RegistrationEventArgs(registration));
}
}
/// <summary>
/// Default constructor.
/// </summary>
/// <param name="registration">SIP reggistration.</param>
/// <exception cref="ArgumentNullException">Is raised when <b>registration</b> is null reference.</exception>
public SIP_RegistrationEventArgs(SIP_Registration registration)
{
if(registration == null){
throw new ArgumentNullException("registration");
}
m_pRegistration = registration;
}
/// <summary>
/// Adds specified registration to collection.
/// </summary>
/// <param name="registration">Registration to add.</param>
public void Add(SIP_Registration registration)
{
lock(m_pRegistrations){
if(Contains(registration.AOR)){
throw new ArgumentException("Registration with specified registration name already exists !");
}
m_pRegistrations.Add(registration);
}
}
/// <summary>
/// Adds specified registration to collection.
/// </summary>
/// <param name="registration">Registration to add.</param>
public void Add(SIP_Registration registration)
{
lock (m_pRegistrations){
if (Contains(registration.AOR))
{
throw new ArgumentException("Registration with specified registration name already exists !");
}
m_pRegistrations.Add(registration);
}
}
/// <summary>
/// Default constructor.
/// </summary>
/// <param name="owner">Owner registration.</param>
/// <param name="contactUri">Contact URI what can be used to contact the registration.</param>
/// <exception cref="ArgumentNullException">Is raised when <b>owner</b> or <b>contactUri</b> is null reference.</exception>
internal SIP_RegistrationBinding(SIP_Registration owner,AbsoluteUri contactUri)
{
if(owner == null){
throw new ArgumentNullException("owner");
}
if(contactUri == null){
throw new ArgumentNullException("contactUri");
}
m_pRegistration = owner;
m_ContactURI = contactUri;
}
/// <summary>
/// Add or updates specified SIP registration info.
/// </summary>
/// <param name="aor">Registration address of record.</param>
/// <param name="contacts">Registration address of record contacts to update.</param>
/// <param name="flow">SIP proxy local data flow what accpeted this contact registration.</param>
public void SetRegistration(string aor, SIP_t_ContactParam[] contacts, SIP_Flow flow)
{
lock (m_pRegistrations){
SIP_Registration registration = m_pRegistrations[aor];
if (registration == null)
{
registration = new SIP_Registration("system", aor);
m_pRegistrations.Add(registration);
OnAorRegistered(registration);
}
registration.AddOrUpdateBindings(flow, "", 1, contacts);
}
}
/// <summary>
/// Default constructor.
/// </summary>
/// <param name="owner">Owner registration.</param>
/// <param name="contactUri">Contact URI what can be used to contact the registration.</param>
/// <exception cref="ArgumentNullException">Is raised when <b>owner</b> or <b>contactUri</b> is null reference.</exception>
internal SIP_RegistrationBinding(SIP_Registration owner, AbsoluteUri contactUri)
{
if (owner == null)
{
throw new ArgumentNullException("owner");
}
if (contactUri == null)
{
throw new ArgumentNullException("contactUri");
}
m_pRegistration = owner;
m_ContactURI = contactUri;
}
/// <summary>
/// Removes all expired registrations from the collection.
/// </summary>
public void RemoveExpired()
{
lock (m_pRegistrations){
for (int i = 0; i < m_pRegistrations.Count; i++)
{
SIP_Registration registration = m_pRegistrations[i];
// Force registration to remove all its expired contacts.
registration.RemoveExpiredBindings();
// No bindings left, so we need to remove that registration.
if (registration.Bindings.Length == 0)
{
m_pRegistrations.Remove(registration);
i--;
}
}
}
}
/// <summary>
/// Forwards specified request to target recipient.
/// </summary>
/// <param name="statefull">Specifies if request is sent statefully or statelessly.</param>
/// <param name="e">Request event arguments.</param>
/// <param name="addRecordRoute">If true Record-Route header field is added.</param>
internal void ForwardRequest(bool statefull, SIP_RequestReceivedEventArgs e, bool addRecordRoute)
{
SIP_RequestContext requestContext = new SIP_RequestContext(this, e.Request, e.Flow);
SIP_Request request = e.Request;
SIP_Uri route = null;
/* RFC 3261 16.
* 1. Validate the request (Section 16.3)
* 1. Reasonable Syntax
* 2. URI scheme (NOTE: We do it later)
* 3. Max-Forwards
* 4. (Optional) Loop Detection
* 5. Proxy-Require
* 6. Proxy-Authorization
* 2. Preprocess routing information (Section 16.4)
* 3. Determine target(s) for the request (Section 16.5)
* x. Custom handling (non-RFC)
* 1. Process custom request handlers.
* 2. URI scheme
* 4. Forward the request (Section 16.6)
*/
#region 1. Validate the request (Section 16.3)
// 1.1 Reasonable Syntax.
// SIP_Message parsing have done it.
// 1.2 URI scheme check.
// We do it later.
// 1.3 Max-Forwards.
if (request.MaxForwards <= 0)
{
e.ServerTransaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x483_Too_Many_Hops, request));
return;
}
// 1.4 (Optional) Loop Detection.
// Skip.
// 1.5 Proxy-Require.
// TODO:
// 1.6 Proxy-Authorization.
/* If an element requires credentials before forwarding a request,
* the request MUST be inspected as described in Section 22.3. That
* section also defines what the element must do if the inspection
* fails.
*/
// We need to auth all foreign calls.
if (!SIP_Utils.IsSipOrSipsUri(request.RequestLine.Uri.ToString()) || !this.OnIsLocalUri(((SIP_Uri)request.RequestLine.Uri).Host))
{
// If To: field is registrar AOR and request-URI is local registration contact, skip authentication.
bool skipAuth = false;
if (request.To.Address.IsSipOrSipsUri)
{
SIP_Registration registration = m_pRegistrar.GetRegistration(((SIP_Uri)request.To.Address.Uri).Address);
if (registration != null)
{
if (registration.GetBinding(request.RequestLine.Uri) != null)
{
skipAuth = true;
}
}
}
if (!skipAuth)
{
string userName = null;
// We need to pass-through ACK.
if (request.RequestLine.Method == SIP_Methods.ACK)
{
}
else if (!AuthenticateRequest(e, out userName))
{
return;
}
requestContext.SetUser(userName);
}
}
#endregion
#region 2. Preprocess routing information (Section 16.4).
/*
* The proxy MUST inspect the Request-URI of the request. If the
* Request-URI of the request contains a value this proxy previously
* placed into a Record-Route header field (see Section 16.6 item 4),
* the proxy MUST replace the Request-URI in the request with the last
* value from the Route header field, and remove that value from the
* Route header field. The proxy MUST then proceed as if it received
* this modified request.
*
* This will only happen when the element sending the request to the
* proxy (which may have been an endpoint) is a strict router. This
* rewrite on receive is necessary to enable backwards compatibility
* with those elements. It also allows elements following this
* specification to preserve the Request-URI through strict-routing
* proxies (see Section 12.2.1.1).
*
* This requirement does not obligate a proxy to keep state in order
* to detect URIs it previously placed in Record-Route header fields.
* Instead, a proxy need only place enough information in those URIs
* to recognize them as values it provided when they later appear.
*
* If the Request-URI contains a maddr parameter, the proxy MUST check
* to see if its value is in the set of addresses or domains the proxy
* is configured to be responsible for. If the Request-URI has a maddr
* parameter with a value the proxy is responsible for, and the request
* was received using the port and transport indicated (explicitly or by
* default) in the Request-URI, the proxy MUST strip the maddr and any
* non-default port or transport parameter and continue processing as if
* those values had not been present in the request.
*
* A request may arrive with a maddr matching the proxy, but on a
* port or transport different from that indicated in the URI. Such
* a request needs to be forwarded to the proxy using the indicated
* port and transport.
*
* If the first value in the Route header field indicates this proxy,
* the proxy MUST remove that value from the request.
*/
// Strict route - handle it.
if ((request.RequestLine.Uri is SIP_Uri) && IsRecordRoute(((SIP_Uri)request.RequestLine.Uri)) && request.Route.GetAllValues().Length > 0)
{
request.RequestLine.Uri = request.Route.GetAllValues()[request.Route.GetAllValues().Length - 1].Address.Uri;
SIP_t_AddressParam[] routes = request.Route.GetAllValues();
route = (SIP_Uri)routes[routes.Length - 1].Address.Uri;
request.Route.RemoveLastValue();
}
// Check if Route header field indicates this proxy.
if (request.Route.GetAllValues().Length > 0)
{
route = (SIP_Uri)request.Route.GetTopMostValue().Address.Uri;
// We consider loose-route always ours, because otherwise this message never reach here.
if (route.Param_Lr)
{
request.Route.RemoveTopMostValue();
}
// It's our route, remove it.
else if (IsLocalRoute(route))
{
request.Route.RemoveTopMostValue();
}
}
#endregion
#region REGISTER request processing
if (e.Request.RequestLine.Method == SIP_Methods.REGISTER)
{
SIP_Uri requestUri = (SIP_Uri)e.Request.RequestLine.Uri;
// REGISTER is meant for us.
if (this.OnIsLocalUri(requestUri.Host))
{
if ((m_ProxyMode & SIP_ProxyMode.Registrar) != 0)
{
m_pRegistrar.Register(e);
return;
}
else
{
e.ServerTransaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x405_Method_Not_Allowed, e.Request));
return;
}
}
// Forward REGISTER.
// else{
}
#endregion
#region 3. Determine target(s) for the request (Section 16.5)
/* 3. Determine target(s) for the request (Section 16.5)
* Next, the proxy calculates the target(s) of the request. The set of
* targets will either be predetermined by the contents of the request
* or will be obtained from an abstract location service. Each target
* in the set is represented as a URI.
*
* If the domain of the Request-URI indicates a domain this element is
* not responsible for, the Request-URI MUST be placed into the target
* set as the only target, and the element MUST proceed to the task of
* Request Forwarding (Section 16.6).
*
* If the target set for the request has not been predetermined as
* described above, this implies that the element is responsible for the
* domain in the Request-URI, and the element MAY use whatever mechanism
* it desires to determine where to send the request. Any of these
* mechanisms can be modeled as accessing an abstract Location Service.
* This may consist of obtaining information from a location service
* created by a SIP Registrar, reading a database, consulting a presence
* server, utilizing other protocols, or simply performing an
* algorithmic substitution on the Request-URI. When accessing the
* location service constructed by a registrar, the Request-URI MUST
* first be canonicalized as described in Section 10.3 before being used
* as an index. The output of these mechanisms is used to construct the
* target set.
*/
// Non-SIP
// Foreign SIP
// Local SIP
if (e.Request.RequestLine.Uri is SIP_Uri)
{
SIP_Uri requestUri = (SIP_Uri)e.Request.RequestLine.Uri;
// Proxy is not responsible for the domain in the Request-URI.
if (!this.OnIsLocalUri(requestUri.Host))
{
/* NAT traversal.
* When we do record routing, store request sender flow info and request target flow info.
* Now the tricky part, how proxy later which flow is target (because both sides can send requests).
* Sender-flow will store from-tag to flow and target-flow will store flowID only (Because we don't know to-tag).
* Later if request to-tag matches(incoming request), use that flow, otherwise(outgoing request) other flow.
*
* flowInfo: sender-flow "/" target-flow
* sender-flow = from-tag ":" flowID
* target-flow = flowID
*/
SIP_Flow targetFlow = null;
string flowInfo = (route != null && route.Parameters["flowInfo"] != null) ? route.Parameters["flowInfo"].Value : null;
if (flowInfo != null && request.To.Tag != null)
{
string flow1Tag = flowInfo.Substring(0, flowInfo.IndexOf(':'));
string flow1ID = flowInfo.Substring(flowInfo.IndexOf(':') + 1, flowInfo.IndexOf('/') - flowInfo.IndexOf(':') - 1);
string flow2ID = flowInfo.Substring(flowInfo.IndexOf('/') + 1);
if (flow1Tag == request.To.Tag)
{
targetFlow = m_pStack.TransportLayer.GetFlow(flow1ID);
}
else
{
;
targetFlow = m_pStack.TransportLayer.GetFlow(flow2ID);
}
}
requestContext.Targets.Add(new SIP_ProxyTarget(requestUri, targetFlow));
}
// Proxy is responsible for the domain in the Request-URI.
else
{
// Try to get AOR from registrar.
SIP_Registration registration = m_pRegistrar.GetRegistration(requestUri.Address);
// We have AOR specified in request-URI in registrar server.
if (registration != null)
{
// Add all AOR SIP contacts to target set.
foreach (SIP_RegistrationBinding binding in registration.Bindings)
{
if (binding.ContactURI is SIP_Uri && binding.TTL > 0)
{
requestContext.Targets.Add(new SIP_ProxyTarget((SIP_Uri)binding.ContactURI, binding.Flow));
}
}
}
// We don't have AOR specified in request-URI in registrar server.
else
{
// If the Request-URI indicates a resource at this proxy that does not
// exist, the proxy MUST return a 404 (Not Found) response.
if (!this.OnAddressExists(requestUri.Address))
{
e.ServerTransaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x404_Not_Found, e.Request));
return;
}
}
// If the target set remains empty after applying all of the above, the proxy MUST return an error response,
// which SHOULD be the 480 (Temporarily Unavailable) response.
if (requestContext.Targets.Count == 0)
{
e.ServerTransaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x480_Temporarily_Unavailable, e.Request));
return;
}
}
}
#endregion
#region x. Custom handling
// x.1 Process custom request handlers, if any.
foreach (SIP_ProxyHandler handler in this.Handlers)
{
try{
SIP_ProxyHandler h = handler;
// Reusing existing handler not allowed, create new instance of handler.
if (!handler.IsReusable)
{
h = (SIP_ProxyHandler)System.Activator.CreateInstance(handler.GetType());
}
if (h.ProcessRequest(requestContext))
{
// Handler processed request, we are done.
return;
}
}
catch (Exception x) {
m_pStack.OnError(x);
}
}
// x.2 URI scheme.
// If no targets and request-URI non-SIP, reject request because custom handlers should have been handled it.
if (requestContext.Targets.Count == 0 && !SIP_Utils.IsSipOrSipsUri(request.RequestLine.Uri.ToString()))
{
e.ServerTransaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x416_Unsupported_URI_Scheme, e.Request));
return;
}
#endregion
#region 4. Forward the request (Section 16.6)
#region Statefull
if (statefull)
{
SIP_ProxyContext proxyContext = this.CreateProxyContext(requestContext, e.ServerTransaction, request, addRecordRoute);
proxyContext.Start();
}
#endregion
#region Stateless
else
{
/* RFC 3261 16.6 Request Forwarding.
* For each target, the proxy forwards the request following these steps:
* 1. Make a copy of the received request
* 2. Update the Request-URI
* 3. Update the Max-Forwards header field
* 4. Optionally add a Record-route header field value
* 5. Optionally add additional header fields
* 6. Postprocess routing information
* 7. Determine the next-hop address, port, and transport
* 8. Add a Via header field value
* 9. Add a Content-Length header field if necessary
* 10. Forward the new request
*/
/* RFC 3261 16.11 Stateless Proxy.
* o A stateless proxy MUST choose one and only one target from the target set. This choice
* MUST only rely on fields in the message and time-invariant properties of the server. In
* particular, a retransmitted request MUST be forwarded to the same destination each time
* it is processed. Furthermore, CANCEL and non-Routed ACK requests MUST generate the same
* choice as their associated INVITE.
*
* However, a stateless proxy cannot simply use a random number generator to compute
* the first component of the branch ID, as described in Section 16.6 bullet 8.
* This is because retransmissions of a request need to have the same value, and
* a stateless proxy cannot tell a retransmission from the original request.
*
* We just use: "z9hG4bK-" + md5(topmost branch)
*/
bool isStrictRoute = false;
SIP_Hop[] hops = null;
#region 1. Make a copy of the received request
SIP_Request forwardRequest = request.Copy();
#endregion
#region 2. Update the Request-URI
forwardRequest.RequestLine.Uri = requestContext.Targets[0].TargetUri;
#endregion
#region 3. Update the Max-Forwards header field
forwardRequest.MaxForwards--;
#endregion
#region 4. Optionally add a Record-route header field value
#endregion
#region 5. Optionally add additional header fields
#endregion
#region 6. Postprocess routing information
/* 6. Postprocess routing information.
*
* If the copy contains a Route header field, the proxy MUST inspect the URI in its first value.
* If that URI does not contain an lr parameter, the proxy MUST modify the copy as follows:
* - The proxy MUST place the Request-URI into the Route header
* field as the last value.
*
* - The proxy MUST then place the first Route header field value
* into the Request-URI and remove that value from the Route header field.
*/
if (forwardRequest.Route.GetAllValues().Length > 0 && !forwardRequest.Route.GetTopMostValue().Parameters.Contains("lr"))
{
forwardRequest.Route.Add(forwardRequest.RequestLine.Uri.ToString());
forwardRequest.RequestLine.Uri = SIP_Utils.UriToRequestUri(forwardRequest.Route.GetTopMostValue().Address.Uri);
forwardRequest.Route.RemoveTopMostValue();
isStrictRoute = true;
}
#endregion
#region 7. Determine the next-hop address, port, and transport
/* 7. Determine the next-hop address, port, and transport.
* The proxy MAY have a local policy to send the request to a
* specific IP address, port, and transport, independent of the
* values of the Route and Request-URI. Such a policy MUST NOT be
* used if the proxy is not certain that the IP address, port, and
* transport correspond to a server that is a loose router.
* However, this mechanism for sending the request through a
* specific next hop is NOT RECOMMENDED; instead a Route header
* field should be used for that purpose as described above.
*
* In the absence of such an overriding mechanism, the proxy
* applies the procedures listed in [4] as follows to determine
* where to send the request. If the proxy has reformatted the
* request to send to a strict-routing element as described in
* step 6 above, the proxy MUST apply those procedures to the
* Request-URI of the request. Otherwise, the proxy MUST apply
* the procedures to the first value in the Route header field, if
* present, else the Request-URI. The procedures will produce an
* ordered set of (address, port, transport) tuples.
* Independently of which URI is being used as input to the
* procedures of [4], if the Request-URI specifies a SIPS
* resource, the proxy MUST follow the procedures of [4] as if the
* input URI were a SIPS URI.
*
* As described in [4], the proxy MUST attempt to deliver the
* message to the first tuple in that set, and proceed through the
* set in order until the delivery attempt succeeds.
*
* For each tuple attempted, the proxy MUST format the message as
* appropriate for the tuple and send the request using a new
* client transaction as detailed in steps 8 through 10.
*
* Since each attempt uses a new client transaction, it represents
* a new branch. Thus, the branch parameter provided with the Via
* header field inserted in step 8 MUST be different for each
* attempt.
*
* If the client transaction reports failure to send the request
* or a timeout from its state machine, the proxy continues to the
* next address in that ordered set. If the ordered set is
* exhausted, the request cannot be forwarded to this element in
* the target set. The proxy does not need to place anything in
* the response context, but otherwise acts as if this element of
* the target set returned a 408 (Request Timeout) final response.
*/
SIP_Uri uri = null;
if (isStrictRoute)
{
uri = (SIP_Uri)forwardRequest.RequestLine.Uri;
}
else if (forwardRequest.Route.GetTopMostValue() != null)
{
uri = (SIP_Uri)forwardRequest.Route.GetTopMostValue().Address.Uri;
}
else
{
uri = (SIP_Uri)forwardRequest.RequestLine.Uri;
}
hops = m_pStack.GetHops(uri, forwardRequest.ToByteData().Length, ((SIP_Uri)forwardRequest.RequestLine.Uri).IsSecure);
if (hops.Length == 0)
{
if (forwardRequest.RequestLine.Method != SIP_Methods.ACK)
{
e.ServerTransaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x503_Service_Unavailable + ": No hop(s) for target.", forwardRequest));
}
return;
}
#endregion
#region 8. Add a Via header field value
forwardRequest.Via.AddToTop("SIP/2.0/transport-tl-addign sentBy-tl-assign-it;branch=z9hG4bK-" + Net_Utils.ComputeMd5(request.Via.GetTopMostValue().Branch, true));
// Add 'flowID' what received request, you should use the same flow to send response back.
// For more info see RFC 3261 18.2.2.
forwardRequest.Via.GetTopMostValue().Parameters.Add("flowID", request.Flow.ID);
#endregion
#region 9. Add a Content-Length header field if necessary
// Skip, our SIP_Message class is smart and do it when ever it's needed.
#endregion
#region 10. Forward the new request
try{
try{
if (requestContext.Targets[0].Flow != null)
{
m_pStack.TransportLayer.SendRequest(requestContext.Targets[0].Flow, request);
return;
}
}
catch {
m_pStack.TransportLayer.SendRequest(request, null, hops[0]);
}
}
catch (SIP_TransportException x) {
string dummy = x.Message;
if (forwardRequest.RequestLine.Method != SIP_Methods.ACK)
{
/* RFC 3261 16.9 Handling Transport Errors
* If the transport layer notifies a proxy of an error when it tries to
* forward a request (see Section 18.4), the proxy MUST behave as if the
* forwarded request received a 503 (Service Unavailable) response.
*/
e.ServerTransaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x503_Service_Unavailable + ": Transport error.", forwardRequest));
}
}
#endregion
}
#endregion
#endregion
}
/// <summary>
/// Raises <b>AorUpdated</b> event.
/// </summary>
/// <param name="registration">SIP registration.</param>
private void OnAorUpdated(SIP_Registration registration)
{
if(this.AorUpdated != null){
this.AorUpdated(this,new SIP_RegistrationEventArgs(registration));
}
}
/// <summary>
/// Handles REGISTER method.
/// </summary>
/// <param name="e">Request event arguments.</param>
internal void Register(SIP_RequestReceivedEventArgs e)
{
/* RFC 3261 10.3 Processing REGISTER Requests.
1. The registrar inspects the Request-URI to determine whether it
has access to bindings for the domain identified in the
Request-URI. If not, and if the server also acts as a proxy
server, the server SHOULD forward the request to the addressed
domain, following the general behavior for proxying messages
described in Section 16.
2. To guarantee that the registrar supports any necessary extensions,
the registrar MUST process the Require header field.
3. A registrar SHOULD authenticate the UAC.
4. The registrar SHOULD determine if the authenticated user is
authorized to modify registrations for this address-of-record.
For example, a registrar might consult an authorization
database that maps user names to a list of addresses-of-record
for which that user has authorization to modify bindings. If
the authenticated user is not authorized to modify bindings,
the registrar MUST return a 403 (Forbidden) and skip the
remaining steps.
5. The registrar extracts the address-of-record from the To header
field of the request. If the address-of-record is not valid
for the domain in the Request-URI, the registrar MUST send a
404 (Not Found) response and skip the remaining steps. The URI
MUST then be converted to a canonical form. To do that, all
URI parameters MUST be removed (including the user-param), and
any escaped characters MUST be converted to their unescaped
form. The result serves as an index into the list of bindings.
6. The registrar checks whether the request contains the Contact
header field. If not, it skips to the last step. If the
Contact header field is present, the registrar checks if there
is one Contact field value that contains the special value "*"
and an Expires field. If the request has additional Contact
fields or an expiration time other than zero, the request is
invalid, and the server MUST return a 400 (Invalid Request) and
skip the remaining steps. If not, the registrar checks whether
the Call-ID agrees with the value stored for each binding. If
not, it MUST remove the binding. If it does agree, it MUST
remove the binding only if the CSeq in the request is higher
than the value stored for that binding. Otherwise, the update
MUST be aborted and the request fails.
7. The registrar now processes each contact address in the Contact
header field in turn. For each address, it determines the
expiration interval as follows:
- If the field value has an "expires" parameter, that value
MUST be taken as the requested expiration.
- If there is no such parameter, but the request has an
Expires header field, that value MUST be taken as the requested expiration.
- If there is neither, a locally-configured default value MUST
be taken as the requested expiration.
The registrar MAY choose an expiration less than the requested
expiration interval. If and only if the requested expiration
interval is greater than zero AND smaller than one hour AND
less than a registrar-configured minimum, the registrar MAY
reject the registration with a response of 423 (Interval Too
Brief). This response MUST contain a Min-Expires header field
that states the minimum expiration interval the registrar is
willing to honor. It then skips the remaining steps.
For each address, the registrar then searches the list of
current bindings using the URI comparison rules. If the
binding does not exist, it is tentatively added. If the
binding does exist, the registrar checks the Call-ID value. If
the Call-ID value in the existing binding differs from the
Call-ID value in the request, the binding MUST be removed if
the expiration time is zero and updated otherwise. If they are
the same, the registrar compares the CSeq value. If the value
is higher than that of the existing binding, it MUST update or
remove the binding as above. If not, the update MUST be
aborted and the request fails.
This algorithm ensures that out-of-order requests from the same
UA are ignored.
Each binding record records the Call-ID and CSeq values from
the request.
The binding updates MUST be committed (that is, made visible to
the proxy or redirect server) if and only if all binding
updates and additions succeed. If any one of them fails (for
example, because the back-end database commit failed), the
request MUST fail with a 500 (Server Error) response and all
tentative binding updates MUST be removed.
8. The registrar returns a 200 (OK) response. The response MUST
contain Contact header field values enumerating all current
bindings. Each Contact value MUST feature an "expires"
parameter indicating its expiration interval chosen by the
registrar. The response SHOULD include a Date header field.
*/
SIP_ServerTransaction transaction = e.ServerTransaction;
SIP_Request request = e.Request;
SIP_Uri to = null;
string userName = "";
// Probably we need to do validate in SIP stack.
#region Validate request
if(SIP_Utils.IsSipOrSipsUri(request.To.Address.Uri.ToString())){
to = (SIP_Uri)request.To.Address.Uri;
}
else{
transaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x400_Bad_Request + ": To: value must be SIP or SIPS URI.",request));
return;
}
#endregion
#region 1. Check if we are responsible for Request-URI domain
// if(m_pProxy.OnIsLocalUri(e.Request.Uri)){
// }
// TODO:
#endregion
#region 2. Check that all required extentions supported
#endregion
#region 3. Authenticate request
if(!m_pProxy.AuthenticateRequest(e,out userName)){
return;
}
#endregion
#region 4. Check if user user is authorized to modify registrations
// We do this in next step(5.).
#endregion
#region 5. Check if address of record exists
if(!m_pProxy.OnAddressExists(to.Address)){
transaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x404_Not_Found,request));
return;
}
else if(!OnCanRegister(userName,to.Address)){
transaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x403_Forbidden,request));
return;
}
#endregion
#region 6. Process * Contact if exists
// Check if we have star contact.
SIP_t_ContactParam starContact = null;
foreach(SIP_t_ContactParam c in request.Contact.GetAllValues()){
if(c.IsStarContact){
starContact = c;
break;
}
}
// We have star contact.
if(starContact != null){
if(request.Contact.GetAllValues().Length > 1){
transaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x400_Bad_Request + ": RFC 3261 10.3.6 -> If star(*) present, only 1 contact allowed.",request));
return;
}
else if(starContact.Expires != 0){
transaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x400_Bad_Request + ": RFC 3261 10.3.6 -> star(*) contact parameter 'expires' value must be always '0'.",request));
return;
}
// Remove bindings.
SIP_Registration reg = m_pRegistrations[to.Address];
if(reg != null){
foreach(SIP_RegistrationBinding b in reg.Bindings){
if(request.CallID != b.CallID || request.CSeq.SequenceNumber > b.CSeqNo){
b.Remove();
}
}
}
}
#endregion
#region 7. Process Contact values
if(starContact == null){
bool newReg = false;
SIP_Registration reg = m_pRegistrations[to.Address];
if(reg == null){
newReg = true;
reg = new SIP_Registration(userName,to.Address);
m_pRegistrations.Add(reg);
}
// We may do updates in batch only.
// We just validate all values then do update(this ensures that update doesn't fail).
// Check expires and CSeq.
foreach(SIP_t_ContactParam c in request.Contact.GetAllValues()){
if(c.Expires == -1){
c.Expires = request.Expires;
}
if(c.Expires == -1){
c.Expires = m_pProxy.Stack.MinimumExpireTime;
}
// We must accept 0 values - means remove contact.
if(c.Expires != 0 && c.Expires < m_pProxy.Stack.MinimumExpireTime){
SIP_Response resp = m_pStack.CreateResponse(SIP_ResponseCodes.x423_Interval_Too_Brief,request);
resp.MinExpires = m_pProxy.Stack.MinimumExpireTime;
transaction.SendResponse(resp);
return;
}
SIP_RegistrationBinding currentBinding = reg.GetBinding(c.Address.Uri);
if(currentBinding != null && currentBinding.CallID == request.CallID && request.CSeq.SequenceNumber < currentBinding.CSeqNo){
transaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x400_Bad_Request + ": CSeq value out of order.",request));
return;
}
}
// Do binding updates.
reg.AddOrUpdateBindings(e.ServerTransaction.Flow,request.CallID,request.CSeq.SequenceNumber,request.Contact.GetAllValues());
// Raise AOR change events.
if(newReg){
OnAorRegistered(reg);
}
else{
OnAorUpdated(reg);
}
}
#endregion
#region 8. Create 200 OK response and return all current bindings
SIP_Response response = m_pStack.CreateResponse(SIP_ResponseCodes.x200_Ok,request);
response.Date = DateTime.Now;
SIP_Registration registration = m_pRegistrations[to.Address];
if(registration != null){
foreach(SIP_RegistrationBinding b in registration.Bindings){
// Don't list expired bindings what wait to be disposed.
if(b.TTL > 1){
response.Header.Add("Contact:",b.ToContactValue());
}
}
}
// Add Authentication-Info:, then client knows next nonce.
response.AuthenticationInfo.Add("qop=\"auth\",nextnonce=\"" + m_pStack.DigestNonceManager.CreateNonce() + "\"");
transaction.SendResponse(response);
#endregion
}
/// <summary>
/// Add or updates specified SIP registration info.
/// </summary>
/// <param name="aor">Registration address of record.</param>
/// <param name="contacts">Registration address of record contacts to update.</param>
/// <param name="flow">SIP proxy local data flow what accpeted this contact registration.</param>
public void SetRegistration(string aor,SIP_t_ContactParam[] contacts,SIP_Flow flow)
{
lock(m_pRegistrations){
SIP_Registration registration = m_pRegistrations[aor];
if(registration == null){
registration = new SIP_Registration("system",aor);
m_pRegistrations.Add(registration);
OnAorRegistered(registration);
}
registration.AddOrUpdateBindings(flow,"",1,contacts);
}
}
/// <summary>
/// Handles REGISTER method.
/// </summary>
/// <param name="e">Request event arguments.</param>
internal void Register(SIP_RequestReceivedEventArgs e)
{
/* RFC 3261 10.3 Processing REGISTER Requests.
* 1. The registrar inspects the Request-URI to determine whether it
* has access to bindings for the domain identified in the
* Request-URI. If not, and if the server also acts as a proxy
* server, the server SHOULD forward the request to the addressed
* domain, following the general behavior for proxying messages
* described in Section 16.
*
* 2. To guarantee that the registrar supports any necessary extensions,
* the registrar MUST process the Require header field.
*
* 3. A registrar SHOULD authenticate the UAC.
*
* 4. The registrar SHOULD determine if the authenticated user is
* authorized to modify registrations for this address-of-record.
* For example, a registrar might consult an authorization
* database that maps user names to a list of addresses-of-record
* for which that user has authorization to modify bindings. If
* the authenticated user is not authorized to modify bindings,
* the registrar MUST return a 403 (Forbidden) and skip the
* remaining steps.
*
* 5. The registrar extracts the address-of-record from the To header
* field of the request. If the address-of-record is not valid
* for the domain in the Request-URI, the registrar MUST send a
* 404 (Not Found) response and skip the remaining steps. The URI
* MUST then be converted to a canonical form. To do that, all
* URI parameters MUST be removed (including the user-param), and
* any escaped characters MUST be converted to their unescaped
* form. The result serves as an index into the list of bindings.
*
* 6. The registrar checks whether the request contains the Contact
* header field. If not, it skips to the last step. If the
* Contact header field is present, the registrar checks if there
* is one Contact field value that contains the special value "*"
* and an Expires field. If the request has additional Contact
* fields or an expiration time other than zero, the request is
* invalid, and the server MUST return a 400 (Invalid Request) and
* skip the remaining steps. If not, the registrar checks whether
* the Call-ID agrees with the value stored for each binding. If
* not, it MUST remove the binding. If it does agree, it MUST
* remove the binding only if the CSeq in the request is higher
* than the value stored for that binding. Otherwise, the update
* MUST be aborted and the request fails.
*
* 7. The registrar now processes each contact address in the Contact
* header field in turn. For each address, it determines the
* expiration interval as follows:
*
* - If the field value has an "expires" parameter, that value
* MUST be taken as the requested expiration.
*
* - If there is no such parameter, but the request has an
* Expires header field, that value MUST be taken as the requested expiration.
*
* - If there is neither, a locally-configured default value MUST
* be taken as the requested expiration.
*
* The registrar MAY choose an expiration less than the requested
* expiration interval. If and only if the requested expiration
* interval is greater than zero AND smaller than one hour AND
* less than a registrar-configured minimum, the registrar MAY
* reject the registration with a response of 423 (Interval Too
* Brief). This response MUST contain a Min-Expires header field
* that states the minimum expiration interval the registrar is
* willing to honor. It then skips the remaining steps.
*
* For each address, the registrar then searches the list of
* current bindings using the URI comparison rules. If the
* binding does not exist, it is tentatively added. If the
* binding does exist, the registrar checks the Call-ID value. If
* the Call-ID value in the existing binding differs from the
* Call-ID value in the request, the binding MUST be removed if
* the expiration time is zero and updated otherwise. If they are
* the same, the registrar compares the CSeq value. If the value
* is higher than that of the existing binding, it MUST update or
* remove the binding as above. If not, the update MUST be
* aborted and the request fails.
*
* This algorithm ensures that out-of-order requests from the same
* UA are ignored.
*
* Each binding record records the Call-ID and CSeq values from
* the request.
*
* The binding updates MUST be committed (that is, made visible to
* the proxy or redirect server) if and only if all binding
* updates and additions succeed. If any one of them fails (for
* example, because the back-end database commit failed), the
* request MUST fail with a 500 (Server Error) response and all
* tentative binding updates MUST be removed.
*
* 8. The registrar returns a 200 (OK) response. The response MUST
* contain Contact header field values enumerating all current
* bindings. Each Contact value MUST feature an "expires"
* parameter indicating its expiration interval chosen by the
* registrar. The response SHOULD include a Date header field.
*/
SIP_ServerTransaction transaction = e.ServerTransaction;
SIP_Request request = e.Request;
SIP_Uri to = null;
string userName = "";
// Probably we need to do validate in SIP stack.
#region Validate request
if (SIP_Utils.IsSipOrSipsUri(request.To.Address.Uri.ToString()))
{
to = (SIP_Uri)request.To.Address.Uri;
}
else
{
transaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x400_Bad_Request + ": To: value must be SIP or SIPS URI.", request));
return;
}
#endregion
#region 1. Check if we are responsible for Request-URI domain
// if(m_pProxy.OnIsLocalUri(e.Request.Uri)){
// }
// TODO:
#endregion
#region 2. Check that all required extentions supported
#endregion
#region 3. Authenticate request
if (!m_pProxy.AuthenticateRequest(e, out userName))
{
return;
}
#endregion
#region 4. Check if user user is authorized to modify registrations
// We do this in next step(5.).
#endregion
#region 5. Check if address of record exists
if (!m_pProxy.OnAddressExists(to.Address))
{
transaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x404_Not_Found, request));
return;
}
else if (!OnCanRegister(userName, to.Address))
{
transaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x403_Forbidden, request));
return;
}
#endregion
#region 6. Process * Contact if exists
// Check if we have star contact.
SIP_t_ContactParam starContact = null;
foreach (SIP_t_ContactParam c in request.Contact.GetAllValues())
{
if (c.IsStarContact)
{
starContact = c;
break;
}
}
// We have star contact.
if (starContact != null)
{
if (request.Contact.GetAllValues().Length > 1)
{
transaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x400_Bad_Request + ": RFC 3261 10.3.6 -> If star(*) present, only 1 contact allowed.", request));
return;
}
else if (starContact.Expires != 0)
{
transaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x400_Bad_Request + ": RFC 3261 10.3.6 -> star(*) contact parameter 'expires' value must be always '0'.", request));
return;
}
// Remove bindings.
SIP_Registration reg = m_pRegistrations[to.Address];
if (reg != null)
{
foreach (SIP_RegistrationBinding b in reg.Bindings)
{
if (request.CallID != b.CallID || request.CSeq.SequenceNumber > b.CSeqNo)
{
b.Remove();
}
}
}
}
#endregion
#region 7. Process Contact values
if (starContact == null)
{
bool newReg = false;
SIP_Registration reg = m_pRegistrations[to.Address];
if (reg == null)
{
newReg = true;
reg = new SIP_Registration(userName, to.Address);
m_pRegistrations.Add(reg);
}
// We may do updates in batch only.
// We just validate all values then do update(this ensures that update doesn't fail).
// Check expires and CSeq.
foreach (SIP_t_ContactParam c in request.Contact.GetAllValues())
{
if (c.Expires == -1)
{
c.Expires = request.Expires;
}
if (c.Expires == -1)
{
c.Expires = m_pProxy.Stack.MinimumExpireTime;
}
// We must accept 0 values - means remove contact.
if (c.Expires != 0 && c.Expires < m_pProxy.Stack.MinimumExpireTime)
{
SIP_Response resp = m_pStack.CreateResponse(SIP_ResponseCodes.x423_Interval_Too_Brief, request);
resp.MinExpires = m_pProxy.Stack.MinimumExpireTime;
transaction.SendResponse(resp);
return;
}
SIP_RegistrationBinding currentBinding = reg.GetBinding(c.Address.Uri);
if (currentBinding != null && currentBinding.CallID == request.CallID && request.CSeq.SequenceNumber < currentBinding.CSeqNo)
{
transaction.SendResponse(m_pStack.CreateResponse(SIP_ResponseCodes.x400_Bad_Request + ": CSeq value out of order.", request));
return;
}
}
// Do binding updates.
reg.AddOrUpdateBindings(e.ServerTransaction.Flow, request.CallID, request.CSeq.SequenceNumber, request.Contact.GetAllValues());
// Raise AOR change events.
if (newReg)
{
OnAorRegistered(reg);
}
else
{
OnAorUpdated(reg);
}
}
#endregion
#region 8. Create 200 OK response and return all current bindings
SIP_Response response = m_pStack.CreateResponse(SIP_ResponseCodes.x200_Ok, request);
response.Date = DateTime.Now;
SIP_Registration registration = m_pRegistrations[to.Address];
if (registration != null)
{
foreach (SIP_RegistrationBinding b in registration.Bindings)
{
// Don't list expired bindings what wait to be disposed.
if (b.TTL > 1)
{
response.Header.Add("Contact:", b.ToContactValue());
}
}
}
// Add Authentication-Info:, then client knows next nonce.
response.AuthenticationInfo.Add("qop=\"auth\",nextnonce=\"" + m_pStack.DigestNonceManager.CreateNonce() + "\"");
transaction.SendResponse(response);
#endregion
}