nua_session.c

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

    ss->ss_reporting = 1;	/* We report terminated state here if BYE fails */
    error = nua_client_create(nh, nua_r_bye, &nua_bye_client_methods, NULL);
    ss->ss_reporting = 0;
    signal_call_state_change(nh, ss, 500, "Internal Error", 
			     error 
			     ? nua_callstate_terminated
			     : nua_callstate_terminating);
  }
  else if (ss)
    signal_call_state_change(nh, ss, 200, "ACK sent", nua_callstate_ready);

  if (!nua_client_is_queued(cr) && !nua_client_is_bound(cr))
    nua_client_request_destroy(cr);

  nua_client_next_request(nh->nh_ds->ds_cr, 1);

  return 0;
}

/** Send ACK, destroy INVITE transaction.
 *
 *  @retval 1 if successful
 *  @retval < 0 if an error occurred
 */
static
int nua_invite_client_ack(nua_client_request_t *cr, tagi_t const *tags)
{
  nua_handle_t *nh = cr->cr_owner;
  nua_dialog_state_t *ds = nh->nh_ds;
  nua_session_usage_t *ss = nua_dialog_usage_private(cr->cr_usage);

  msg_t *msg;
  sip_t *sip;
  int error = -1;
  sip_authorization_t *wa;
  sip_proxy_authorization_t *pa;
  sip_cseq_t *cseq;
  int proxy_is_set;
  url_string_t *proxy;
  nta_outgoing_t *ack;
  int status = 200;
  char const *phrase = "OK", *reason = NULL;
  char const *invite_branch;

  assert(cr->cr_orq);
  assert(cr->cr_method == sip_method_invite);


  if (!ds->ds_leg) {
    /* XXX - fix nua_dialog_usage_remove_at() instead! */
    nta_outgoing_destroy(cr->cr_orq);
    return -1;
  }

  assert(ds->ds_leg);

  msg = nta_outgoing_getrequest(cr->cr_orq);
  sip = sip_object(msg);
  if (!msg)
    return -1;
  invite_branch = nta_outgoing_branch(cr->cr_orq);

  wa = sip_authorization(sip);
  pa = sip_proxy_authorization(sip);
  
  msg_destroy(msg);

  msg = nta_msg_create(nh->nh_nua->nua_nta, 0);
  sip = sip_object(msg);  
  if (!msg)
    return -1;

  cseq = sip_cseq_create(msg_home(msg), cr->cr_seq, SIP_METHOD_ACK);

  if (!cseq)
    ;
  else if (nh->nh_tags && sip_add_tl(msg, sip, TAG_NEXT(nh->nh_tags)) < 0)
    ;
  else if (tags && sip_add_tl(msg, sip, TAG_NEXT(tags)) < 0)
    ;
  else if (wa && sip_add_dup(msg, sip, (sip_header_t *)wa) < 0)
    ;
  else if (pa && sip_add_dup(msg, sip, (sip_header_t *)pa) < 0)
    ;
  else if (sip_header_insert(msg, sip, (sip_header_t *)cseq) < 0)
    ;
  else if (nta_msg_request_complete(msg, ds->ds_leg, SIP_METHOD_ACK, NULL) < 0)
    ;
  else {
    /* Remove extra headers */
    while (sip->sip_allow)
      sip_header_remove(msg, sip, (sip_header_t*)sip->sip_allow);
    while (sip->sip_priority)
      sip_header_remove(msg, sip, (sip_header_t*)sip->sip_priority);
    while (sip->sip_proxy_require)
      sip_header_remove(msg, sip, (sip_header_t*)sip->sip_proxy_require);
    while (sip->sip_require)
      sip_header_remove(msg, sip, (sip_header_t*)sip->sip_require);
    while (sip->sip_subject)
      sip_header_remove(msg, sip, (sip_header_t*)sip->sip_subject);
    while (sip->sip_supported)
      sip_header_remove(msg, sip, (sip_header_t*)sip->sip_supported);

    if (ss == NULL || ss->ss_state >= nua_callstate_ready)
      ;
    else if (cr->cr_offer_recv && !cr->cr_answer_sent) {
      if (nh->nh_soa == NULL) {
	if (session_get_description(sip, NULL, NULL))
	  cr->cr_answer_sent = 1, ss->ss_oa_sent = Answer;
      }
      else if (soa_generate_answer(nh->nh_soa, NULL) < 0 ||
	  session_include_description(nh->nh_soa, 1, msg, sip) < 0) {
	status = 900, phrase = "Internal media error";
	reason = "SIP;cause=500;text=\"Internal media error\"";
	/* reason = soa_error_as_sip_reason(nh->nh_soa); */
      }
      else {
	cr->cr_answer_sent = 1, ss->ss_oa_sent = Answer;
      }
    }

    if (ss == NULL || ss->ss_state >= nua_callstate_ready || reason)
      ;
    else if (nh->nh_soa && soa_is_complete(nh->nh_soa)) {
      /* signal SOA that O/A round(s) is (are) complete */
	soa_activate(nh->nh_soa, NULL);
    }
    else if (nh->nh_soa == NULL
	     /* NUA does not necessarily know dirty details */
	     /* && !(cr->cr_offer_sent && !cr->cr_answer_recv) */) {
      ;
    }
    else {
      nua_client_request_t *cru;

      /* Final response to UPDATE or PRACK may be on its way ... */
      for (cru = ds->ds_cr; cru; cru = cru->cr_next) {
	if (cr != cru && cru->cr_offer_sent && !cru->cr_answer_recv)
	  break;
      }

      if (cru == NULL) {
	/* No SDP answer -> terminate call */
	status = 988, phrase = "Incomplete offer/answer";
	reason = "SIP;cause=488;text=\"Incomplete offer/answer\"";
      }
    }
    
    proxy_is_set = NH_PISSET(nh, proxy);
    proxy = NH_PGET(nh, proxy);

    if ((ack = nta_outgoing_mcreate(nh->nh_nua->nua_nta, NULL, NULL, NULL,
				    msg,
				    NTATAG_ACK_BRANCH(invite_branch),
				    TAG_IF(proxy_is_set,
					   NTATAG_DEFAULT_PROXY(proxy)),
				    SIPTAG_END(),
				    TAG_NEXT(tags)))) {
      /* TR engine keeps this around for T2 so it catches all 2XX retransmissions  */
      nta_outgoing_destroy(ack);

      if (nh->nh_soa && reason && ss && ss->ss_state <= nua_callstate_ready)
	nua_stack_event(nh->nh_nua, nh, NULL,
			nua_i_media_error, status, phrase,
			NULL);
    }
    else if (!reason) {
      status = 900, phrase = "Cannot send ACK";
      reason = "SIP;cause=500;text=\"Internal Error\"";
    }

    if (ss && reason)
      ss->ss_reason = reason;

    if (status < 300)
      error = 1;
    else
      error = -2;
  }

  if (error == -1)
    msg_destroy(msg);

  nta_outgoing_destroy(cr->cr_orq), cr->cr_orq = NULL;
  nua_client_request_remove(cr);
  
  return error;
}

/** Complete client request */
static int nua_invite_client_complete(nua_client_request_t *cr)
{
  if (cr->cr_orq == NULL)
    /* Xyzzy */;
  else if (cr->cr_status < 200)
    nta_outgoing_cancel(cr->cr_orq);
  else
    nua_invite_client_ack(cr, NULL);

  return 0;
}

/**@fn void nua_cancel(nua_handle_t *nh, tag_type_t tag, tag_value_t value, ...);
 *
 * Cancel an INVITE operation 
 *
 * @param nh              Pointer to operation handle
 * @param tag, value, ... List of tagged parameters
 *
 * @return 
 *    nothing
 *
 * @par Related Tags:
 *    Header tags defined in <sofia-sip/sip_tag.h>
 *
 * @par Events:
 *    #nua_r_cancel, #nua_i_state  (#nua_i_active, #nua_i_terminated)
 *
 * @sa @ref nua_call_model, nua_invite(), #nua_i_cancel
 */

static int nua_cancel_client_request(nua_client_request_t *cr,
				     msg_t *msg, sip_t *sip,
				     tagi_t const *tags);

nua_client_methods_t const nua_cancel_client_methods = {
  SIP_METHOD_CANCEL,		/* crm_method, crm_method_name */
  0,				/* crm_extra */
  {				/* crm_flags */
    /* create_dialog */ 0,
    /* in_dialog */ 1,
    /* target refresh */ 0
  },
  NULL,				/* crm_template */
  NULL,				/* crm_init */
  nua_cancel_client_request,	/* crm_send */
  NULL,				/* crm_check_restart */
  NULL,				/* crm_recv */
  NULL,				/* crm_preliminary */
  NULL,				/* crm_report */
  NULL,				/* crm_complete */
};

int nua_stack_cancel(nua_t *nua, nua_handle_t *nh, nua_event_t e,
		     tagi_t const *tags)
{
  return nua_client_create(nh, e, &nua_cancel_client_methods, tags);
}

static int nua_cancel_client_request(nua_client_request_t *cr,
				     msg_t *msg, sip_t *sip,
				     tagi_t const *tags)
{
  nua_handle_t *nh = cr->cr_owner;
  nua_dialog_usage_t *du = nua_dialog_usage_for_session(nh->nh_ds);

  if (!du || !du->du_cr || !du->du_cr->cr_orq || 
      nta_outgoing_status(du->du_cr->cr_orq) >= 200) {
    return nua_client_return(cr, 481, "No transaction to CANCEL", msg);
  }

  cr->cr_orq = nta_outgoing_tcancel(du->du_cr->cr_orq,
				    nua_client_orq_response, cr,
				    TAG_NEXT(tags));

  return cr->cr_orq ? 0 : -1;
}

/** @NUA_EVENT nua_r_cancel
 *
 * Answer to outgoing CANCEL.
 *
 * The CANCEL may be sent explicitly by nua_cancel() or implicitly by NUA
 * state machine.
 *
 * @param status response status code 
 * @param phrase a short textual description of @a status code
 * @param nh     operation handle associated with the call
 * @param hmagic application context associated with the call
 * @param sip    response to CANCEL request or NULL upon an error
 *               (status code is in @a status and 
 *                descriptive message in @a phrase parameters)
 * @param tags   empty
 *
 * @sa nua_cancel(), @ref nua_uac_call_model, #nua_r_invite, nua_invite(),
 * #nua_i_state
 *
 * @END_NUA_EVENT
 */

static void nua_session_usage_refresh(nua_handle_t *nh,
				      nua_dialog_state_t *ds,
				      nua_dialog_usage_t *du,
				      sip_time_t now)
{
  nua_session_usage_t *ss = NUA_DIALOG_USAGE_PRIVATE(du);
  nua_client_request_t const *cr = du->du_cr;
  nua_server_request_t const *sr;

  if (ss->ss_state >= nua_callstate_terminating || 
      /* INVITE is in progress or being authenticated */
      (cr && (cr->cr_orq || cr->cr_wait_for_cred)))
    return;

  /* UPDATE has been queued */
  for (cr = ds->ds_cr; cr; cr = cr->cr_next) 
    if (cr->cr_method == sip_method_update)
      return;

  /* INVITE or UPDATE in progress on server side */
  for (sr = ds->ds_sr; sr; sr = sr->sr_next)
    if (sr->sr_usage == du && 
	(sr->sr_method == sip_method_invite || 
	 sr->sr_method == sip_method_update))
      return;

  if (ss->ss_timer->refresher == nua_remote_refresher) {
    ss->ss_reason = "SIP;cause=408;text=\"Session timeout\""; 
    nua_stack_bye(nh->nh_nua, nh, nua_r_bye, NULL);
    return;
  }
  else if (NH_PGET(nh, update_refresh)) {
    nua_stack_update(nh->nh_nua, nh, nua_r_update, NULL);
  }
  else if (du->du_cr) {
    nua_client_resend_request(du->du_cr, 0);
  }
  else {
    nua_stack_invite(nh->nh_nua, nh, nua_r_invite, NULL);
  }
}

/** @interal Shut down session usage. 
 *
 * @retval >0  shutdown done
 * @retval 0   shutdown in progress
 * @retval <0  try again later
 */
static int nua_session_usage_shutdown(nua_handle_t *nh,
				      nua_dialog_state_t *ds,
				      nua_dialog_usage_t *du)
{
  nua_session_usage_t *ss = NUA_DIALOG_USAGE_PRIVATE(du);
  nua_server_request_t *sr, *sr_next;
  nua_client_request_t *cri;

  assert(ss == nua_session_usage_for_dialog(nh->nh_ds));

  /* Zap server-side transactions */
  for (sr = ds->ds_sr; sr; sr = sr_next) {
    sr_next = sr->sr_next;
    if (sr->sr_usage == du) {
      assert(sr->sr_usage == du);
      sr->sr_usage = NULL;

      if (nua_server_request_is_pending(sr)) {
	SR_STATUS1(sr, SIP_480_TEMPORARILY_UNAVAILABLE);
	nua_server_respond(sr, NULL);
	if (nua_server_report(sr) >= 2)
	  return 480;
      }
      else
	nua_server_request_destroy(sr);
    }
  }

  cri = du->du_cr;

  switch (ss->ss_state) {
  case nua_callstate_calling:
  case nua_callstate_proceeding:
    return nua_client_create(nh, nua_r_cancel, &nua_cancel_client_methods, NULL);

  case nua_callstate_completing:
  case nua_callstate_completed:
  case nua_callstate_ready:
    if (cri && cri->cr_orq) {
      if (cri->cr_status < 200)
	nua_client_create(nh, nua_r_cancel, &nua_cancel_client_methods, NULL);
      else if (cri->cr_status < 300)
	nua_invite_client_ack(cri, NULL);
    }
    if (nua_client_create(nh, nua_r_bye, &nua_bye_client_methods, NULL) != 0)
      break;

    signal_call_state_change(nh, ss, 487, "BYE sent",
			     nua_callstate_terminating);
    return 0;

  case nua_callstate_terminating:
  case nua_callstate_terminated: /* XXX */
    return 0;

  default:
    break;