/// <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>
/// 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>
/// 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>
/// 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)
{
SIP_Registration reg = m_pRegistrations[to.Address];
if (reg == null)
{
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());
}
#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>
/// Raises <b>AorUpdated</b> event.
/// </summary>
/// <param name="registration">SIP registration.</param>
private void OnAorUpdated(SIP_Registration registration)
{
if (AorUpdated != null)
{
AorUpdated(this, new SIP_RegistrationEventArgs(registration));
}
}
/// <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);
}
}