nua_stack.c

Sofia SIP is an open-source SIP User-Agent library, compliant with the IETF RFC3261 specification.

void nh_destroy(nua_t *nua, nua_handle_t *nh)
{
  assert(nh); assert(nh != nua->nua_dhandle);

  if (nh->nh_notifier)
    nea_server_destroy(nh->nh_notifier), nh->nh_notifier = NULL;

  while (nh->nh_ds->ds_cr)
    nua_client_request_destroy(nh->nh_ds->ds_cr);

  while (nh->nh_ds->ds_sr)
    nua_server_request_destroy(nh->nh_ds->ds_sr);

  nua_dialog_deinit(nh, nh->nh_ds);

  if (nh->nh_soa)
    soa_destroy(nh->nh_soa), nh->nh_soa = NULL;

  if (nh_is_inserted(nh))
    nh_remove(nua, nh);

  nua_handle_unref(nh);		/* Remove stack reference */
}

/* ======================================================================== */

/**@internal
 * Save handle parameters and initial authentication info.
 *
 * @retval -1 upon an error
 * @retval 0 when successful
 */
int nua_stack_init_handle(nua_t *nua, nua_handle_t *nh, tagi_t const *tags)
{
  int retval = 0;

  if (nh == NULL)
    return -1;

  assert(nh != nua->nua_dhandle);

  if (nua_stack_set_params(nua, nh, nua_i_error, tags) < 0)
    retval = -1;

  if (retval || nh->nh_init) /* Already initialized? */
    return retval;

  if (nh->nh_tags)
    nh_authorize(nh, TAG_NEXT(nh->nh_tags));

  nh->nh_init = 1;

  return 0;
}

/** @internal Create a handle for processing incoming request */
nua_handle_t *nua_stack_incoming_handle(nua_t *nua,
					nta_incoming_t *irq,
					sip_t const *sip,
					int create_dialog)
{
  nua_handle_t *nh;
  url_t const *url;
  sip_to_t to[1];
  sip_from_t from[1];

  assert(sip && sip->sip_from && sip->sip_to);

  if (sip->sip_contact)
    url = sip->sip_contact->m_url;
  else
    url = sip->sip_from->a_url;

  /* Strip away parameters */
  sip_from_init(from)->a_display = sip->sip_to->a_display;
  *from->a_url = *sip->sip_to->a_url;

  sip_to_init(to)->a_display = sip->sip_from->a_display;
  *to->a_url = *sip->sip_from->a_url;

  nh = nh_create(nua,
		 NUTAG_URL((url_string_t *)url), /* Remote target */
		 SIPTAG_TO(to), /* Local AoR */
		 SIPTAG_FROM(from), /* Remote AoR */
		 TAG_END());

  if (nh && nua_stack_init_handle(nua, nh, NULL) < 0)
    nh_destroy(nua, nh), nh = NULL;

  if (nh && create_dialog) {
    struct nua_dialog_state *ds = nh->nh_ds;

    nua_dialog_store_peer_info(nh, ds, sip);

    ds->ds_leg = nta_leg_tcreate(nua->nua_nta, nua_stack_process_request, nh,
				 SIPTAG_CALL_ID(sip->sip_call_id),
				 SIPTAG_FROM(sip->sip_to),
				 SIPTAG_TO(sip->sip_from),
				 NTATAG_REMOTE_CSEQ(sip->sip_cseq->cs_seq),
				 TAG_END());

    if (!ds->ds_leg || !nta_leg_tag(ds->ds_leg, nta_incoming_tag(irq, NULL)))
      nh_destroy(nua, nh), nh = NULL;
  }

  if (nh)
    nua_dialog_uas_route(nh, nh->nh_ds, sip, 1);

  return nh;
}


/** Set flags and special event on handle.
 *
 * @retval 0 when successful
 * @retval -1 upon an error
 */
int nua_stack_set_handle_special(nua_handle_t *nh,
				 enum nh_kind kind,
				 nua_event_t special)
{
  if (nh == NULL)
    return -1;

  if (special && nh->nh_special && nh->nh_special != special)
    return -1;

  if (!nh_is_special(nh) && !nh->nh_has_invite) {
    switch (kind) {
    case nh_has_invite:    nh->nh_has_invite = 1;    break;
    case nh_has_subscribe: nh->nh_has_subscribe = 1; break;
    case nh_has_notify:    nh->nh_has_notify = 1;    break;
    case nh_has_register:  nh->nh_has_register = 1;  break;
    case nh_has_nothing:
    default:
      break;
    }

    if (special)
      nh->nh_special = special;
  }

  return 0;
}

sip_replaces_t *nua_stack_handle_make_replaces(nua_handle_t *nh, 
					       su_home_t *home,
					       int early_only)
{
  if (nh && nh->nh_ds && nh->nh_ds->ds_leg)
    return nta_leg_make_replaces(nh->nh_ds->ds_leg, home, early_only);
  else
    return NULL;
}

nua_handle_t *nua_stack_handle_by_replaces(nua_t *nua,
					   sip_replaces_t const *r)
{
  if (nua) {
    nta_leg_t *leg = nta_leg_by_replaces(nua->nua_nta, r);
    if (leg)
      return nta_leg_magic(leg, nua_stack_process_request);
  }
  return NULL;
}

nua_handle_t *nua_stack_handle_by_call_id(nua_t *nua, const char *call_id)
{
  if (nua) {
    nta_leg_t *leg = nta_leg_by_call_id(nua->nua_nta, call_id);
    if (leg)
      return nta_leg_magic(leg, nua_stack_process_request);
  }
  return NULL;
}

/** @internal Add authorization data */
int nh_authorize(nua_handle_t *nh, tag_type_t tag, tag_value_t value, ...)
{
  int retval = 0;
  tagi_t const *ti;
  ta_list ta;

  ta_start(ta, tag, value);

  for (ti = ta_args(ta); ti; ti = tl_next(ti)) {
    if (ti->t_tag == nutag_auth && ti->t_value) {
      char *data = (char *)ti->t_value;
      int rv = auc_credentials(&nh->nh_auth, nh->nh_home, data);

      if (rv > 0) {
	retval = 1;
      }
      else if (rv < 0) {
	retval = -1;
	break;
      }
    }
  }

  ta_end(ta);

  return retval;
}

su_inline
int can_redirect(sip_contact_t const *m, sip_method_t method)
{
  if (m && m->m_url->url_host) {
    enum url_type_e type = m->m_url->url_type;
    return
      type == url_sip ||
      type == url_sips ||
      (type == url_tel &&
       (method == sip_method_invite || method == sip_method_message)) ||
      (type == url_im && method == sip_method_message) ||
      (type == url_pres && method == sip_method_subscribe);
  }
  return 0;
}

/* ======================================================================== */
/* Authentication */

/** @NUA_EVENT nua_r_authenticate
 *
 * Response to nua_authenticate(). Under normal operation, this event is
 * never sent but rather the unauthenticated operation is completed. 
 * However, if there is no operation to authentication or if there is an
 * authentication error the #nua_r_authenticate event is sent to the
 * application with the status code as follows:
 * - <i>202 No operation to restart</i>:\n
 *   The authenticator associated with the handle was updated, but there was
 *   no operation to retry with the new credentials.
 * - <i>900 Cannot add credentials</i>:\n
 *   There was internal problem updating authenticator.
 * - <i>904 No matching challenge</i>:\n
 *   There was no challenge matching with the credentials provided by
 *   nua_authenticate(), e.g., their realm did not match with the one 
 *   received with the challenge.
 * 
 * @param status status code from authentication 
 * @param phrase a short textual description of @a status code
 * @param nh     operation handle authenticated
 * @param hmagic application context associated with the handle
 * @param sip    NULL
 * @param tags   empty
 * 
 * @sa nua_terminate(), nua_handle_destroy()
 *
 * @END_NUA_EVENT
 */

void
nua_stack_authenticate(nua_t *nua, nua_handle_t *nh, nua_event_t e,
		       tagi_t const *tags)
{
  nua_client_request_t *cr = nh->nh_ds->ds_cr;
  int status = nh_authorize(nh, TAG_NEXT(tags));

  if (status > 0) {
    if (cr && cr->cr_wait_for_cred) {
      cr->cr_waiting = cr->cr_wait_for_cred = 0;
      nua_client_restart_request(cr, cr->cr_terminating, tags);
    }
    else {
      nua_stack_event(nua, nh, NULL, e, 
		      202, "No operation to restart",
		      NULL);
    }
  }
  else if (cr && cr->cr_wait_for_cred) {
    cr->cr_waiting = cr->cr_wait_for_cred = 0;
    
    if (status < 0)
      nua_client_response(cr, 900, "Operation cannot add credentials", NULL);
    else
      nua_client_response(cr, 904, "Operation has no matching challenge ", NULL);
  }
  else if (status < 0) {
    nua_stack_event(nua, nh, NULL, e, 900, "Cannot add credentials", NULL);
  }
  else {
    nua_stack_event(nua, nh, NULL, e, 904, "No matching challenge", NULL);
  }
}


/* ======================================================================== */
/*
 * Process incoming requests
 */

nua_server_methods_t const *nua_server_methods[] = {
  /* These must be in same order as in sip_method_t */
  &nua_extension_server_methods,
  &nua_invite_server_methods,	/**< INVITE */
  NULL,				/**< ACK */
  NULL,				/**< CANCEL */
  &nua_bye_server_methods,	/**< BYE */
  &nua_options_server_methods,	/**< OPTIONS */
  &nua_register_server_methods,	/**< REGISTER */
  &nua_info_server_methods,	/**< INFO */
  &nua_prack_server_methods,	/**< PRACK */
  &nua_update_server_methods,	/**< UPDATE */
  &nua_message_server_methods,	/**< MESSAGE */
  &nua_subscribe_server_methods,/**< SUBSCRIBE */
  &nua_notify_server_methods,	/**< NOTIFY */
  &nua_refer_server_methods,	/**< REFER */
  &nua_publish_server_methods,	/**< PUBLISH */
  NULL
};


int nua_stack_process_request(nua_handle_t *nh,
			      nta_leg_t *leg,
			      nta_incoming_t *irq,
			      sip_t const *sip)
{
  nua_t *nua = nh->nh_nua;
  sip_method_t method = sip->sip_request->rq_method;
  char const *name = sip->sip_request->rq_method_name;
  nua_server_methods_t const *sm;
  nua_server_request_t *sr, sr0[1];
  int status, initial = 1;
  int create_dialog;

  char const *user_agent = NH_PGET(nh, user_agent);
  sip_supported_t const *supported = NH_PGET(nh, supported);
  sip_allow_t const *allow = NH_PGET(nh, allow);

  enter;

  nta_incoming_tag(irq, NULL);

  if (method == sip_method_cancel)
    return 481;

  /* Hook to outbound */
  if (method == sip_method_options) {
    status = nua_registration_process_request(nua->nua_registrations,
					      irq, sip);
    if (status)
      return status;
  }

  if (nta_check_method(irq, sip, allow,
		       SIPTAG_SUPPORTED(supported),
		       SIPTAG_USER_AGENT_STR(user_agent),
		       TAG_END()))
    return 405;

  switch (sip->sip_request->rq_url->url_type) {
  case url_sip:
  case url_sips:
  case url_im:
  case url_pres:
  case url_tel:
    break;
  default:
    nta_incoming_treply(irq, status = SIP_416_UNSUPPORTED_URI,
			SIPTAG_ALLOW(allow),
			SIPTAG_SUPPORTED(supported),
			SIPTAG_USER_AGENT_STR(user_agent),
			TAG_END());
    return status;
  }

  if (nta_check_required(irq, sip, supported,
			 SIPTAG_ALLOW(allow),
			 SIPTAG_USER_AGENT_STR(user_agent),
			 TAG_END()))
    return 420;

  if (method > sip_method_unknown && method <= sip_method_publish)
    sm = nua_server_methods[method];
  else
    sm = nua_server_methods[0];

  initial = nh == nua->nua_dhandle;

  if (sm == NULL) {
    SU_DEBUG_1(("nua(%p): strange %s from <" URL_PRINT_FORMAT ">\n",
		(void *)nh, sip->sip_request->rq_method_name,
		URL_PRINT_ARGS(sip->sip_from->a_url)));
  }
  else if (initial && sm->sm_flags.in_dialog) {
    /* These must be in-dialog */
    sm = NULL;
  }
  else if (initial && sip->sip_to->a_tag) {
    /* RFC 3261 section 12.2.2:
       
       If the UAS wishes to reject the request because it does not wish to
       recreate the dialog, it MUST respond to the request with a 481
       (Call/Transaction Does Not Exist) status code and pass that to the
       server transaction.
    */
    if (method == sip_method_info)
      /* accept out-of-dialog info */; else
    if (method != sip_method_message || !NH_PGET(nh, win_messenger_enable))
      sm = NULL;
  }

  if (!sm) {
    nta_incoming_treply(irq,
			status = 481, "Call Does Not Exist",
			SIPTAG_ALLOW(allow),
			SIPTAG_SUPPORTED(supported),
			SIPTAG_USER_AGENT_STR(user_agent),
			TAG_END());
    return 481;
  }

  create_dialog = sm->sm_flags.create_dialog;
  if (method == sip_method_message && NH_PGET(nh, win_messenger_enable))
    create_dialog = 1;
  sr = memset(sr0, 0, (sizeof sr0));

  sr->sr_methods = sm;
  sr->sr_method = method = sip->sip_request->rq_method;
  sr->sr_add_contact = sm->sm_flags.add_contact;
  sr->sr_target_refresh = sm->sm_flags.target_refresh;

  sr->sr_owner = nh;
  sr->sr_initial = initial;

  sr->sr_irq = irq;

  SR_STATUS1(sr, SIP_100_TRYING);

  sr->sr_request.msg = nta_incoming_getrequest(irq);
  sr->sr_request.sip = sip;
  assert(sr->sr_request.msg);

  sr->sr_response.msg = nta_incoming_create_response(irq, 0, NULL);
  sr->sr_response.sip = sip_object(sr->sr_response.msg);

  if (sr->sr_response.msg == NULL) {
    SR_STATUS1(sr, SIP_500_INTERNAL_SERVER_ERROR);
  }
  else if (sm->sm_init && sm->sm_init(sr)) {
    if (sr->sr_status < 200)    /* Init may have set response status */
      SR_STATUS1(sr, SIP_500_INTERNAL_SERVER_ERROR);
  }
  /* Create handle if request does not fail */
  else if (initial && sr->sr_status < 300) {
    if ((nh = nua_stack_incoming_handle(nua, irq, sip, create_dialog)))
      sr->sr_owner = nh;
    else
      SR_STATUS1(sr, SIP_500_INTERNAL_SERVER_ERROR);
  }

  if (sr->sr_status < 300 && sm->sm_preprocess && sm->sm_preprocess(sr)) {
    if (sr->sr_status < 200)    /* Set response status if preprocess did not */
      SR_STATUS1(sr, SIP_500_INTERNAL_SERVER_ERROR);
  }

  if (sr->sr_status < 300) {
    if (sr->sr_target_refresh)
      nua_dialog_uas_route(nh, nh->nh_ds, sip, 1); /* Set route and tags */
    nua_dialog_store_peer_info(nh, nh->nh_ds, sip);
  }

  if (sr->sr_status == 100 && method != sip_method_unknown &&
      !sip_is_allowed(NH_PGET(sr->sr_owner, appl_method), method, name)) {
    if (method == sip_method_refer || method == sip_method_subscribe)
      SR_STATUS1(sr, SIP_202_ACCEPTED);
    else
      SR_STATUS1(sr, SIP_200_OK);
  }

  /* INVITE server request is not finalized after 2XX response */
  if (sr->sr_status < (method == sip_method_invite ? 300 : 200)) {
    sr = su_alloc(nh->nh_home, (sizeof *sr));

    if (sr) {