nua_subnotref.c

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

     * XXX - If we have received a NOTIFY, we should try to terminate
     * subscription
     */
  }

  if (!eu->eu_unsolicited)
    nua_stack_tevent(nh->nh_nua, nh, NULL,
		     nua_i_notify, NUA_ERROR_AT(__FILE__, __LINE__),
		     NUTAG_SUBSTATE(nua_substate_terminated),
		     SIPTAG_EVENT(du->du_event),
		     TAG_END());

  nua_dialog_usage_remove(nh, ds, du, NULL, NULL);
}

/** Terminate subscription.
 *
 * @retval >0  shutdown done
 * @retval 0   shutdown in progress
 * @retval <0  try again later
 */
static int nua_subscribe_usage_shutdown(nua_handle_t *nh,
					nua_dialog_state_t *ds,
					nua_dialog_usage_t *du)
{
  struct event_usage *eu = nua_dialog_usage_private(du);
  nua_client_request_t *cr = du->du_cr;

  assert(eu); (void)eu;

  if (cr) {
    if (nua_client_resend_request(cr, 1) >= 0)
      return 0;
  }
  
  nua_dialog_usage_remove(nh, ds, du, NULL, NULL);
  return 200;
}

/* ======================================================================== */
/* NOTIFY server */

/** @NUA_EVENT nua_i_notify
 *
 * Event for incoming NOTIFY request.
 *
 * @param status statuscode of response sent automatically by stack
 * @param phrase a short textual description of @a status code
 * @param nh     operation handle associated with the subscription
 * @param hmagic application context associated with the handle
 * @param sip    incoming NOTIFY request
 * @param tags   NUTAG_SUBSTATE() indicating the subscription state
 *
 * @sa nua_subscribe(), nua_unsubscribe(), @RFC3265, #nua_i_subscribe
 * 
 * @END_NUA_EVENT
 */

int nua_notify_server_init(nua_server_request_t *sr);
int nua_notify_server_preprocess(nua_server_request_t *sr);
int nua_notify_server_report(nua_server_request_t *, tagi_t const *);

nua_server_methods_t const nua_notify_server_methods = 
  {
    SIP_METHOD_NOTIFY,
    nua_i_notify,		/* Event */
    { 
      /* create_dialog: */ 1,	/* Do create dialog */
      /* in_dialog: */ 0,	/* Not always in-dialog request */
      /* target_refresh: */ 1,	/* Target refresh request  */
      /* add_contact: */ 1,	/* Add Contact to response */
    },
    nua_notify_server_init,
    nua_notify_server_preprocess,
    nua_base_server_params,
    nua_base_server_respond,
    nua_notify_server_report,
  };


int nua_notify_server_init(nua_server_request_t *sr)
{
  if (!sr->sr_initial) {
    nua_dialog_state_t *ds = sr->sr_owner->nh_ds;

    /* Check for forked subscription. */
    if (ds->ds_remote_tag && ds->ds_remote_tag[0] && 
	str0cmp(ds->ds_remote_tag, sr->sr_request.sip->sip_from->a_tag)) {
      sip_contact_t const *m = NULL;

      m = nua_stack_get_contact(sr->sr_owner->nh_nua->nua_registrations);
      
      if (m) {
	sip_warning_t w[1];
	
	sip_warning_init(w)->w_code = 399;
	w->w_host = m->m_url->url_host;
	w->w_port = m->m_url->url_port;
	w->w_text = "Forking SUBSCRIBEs are not supported";

	sip_add_dup(sr->sr_response.msg, NULL, (sip_header_t*)w);
      }

      return SR_STATUS(sr, 481, "Subscription Does Not Exist");
    }
  }

  return 0;
}

int nua_notify_server_preprocess(nua_server_request_t *sr)
{
  nua_dialog_state_t *ds = sr->sr_owner->nh_ds;
  nua_dialog_usage_t *du;
  struct event_usage *eu;
  sip_t const *sip = sr->sr_request.sip;
  sip_event_t *o = sip->sip_event;
  enum nua_substate substate = nua_substate_terminated;
  sip_subscription_state_t *subs = sip->sip_subscription_state;
  char const *what = "", *reason = NULL;
  int solicited = 1;

  du = nua_dialog_usage_get(ds, nua_subscribe_usage, o);

  if (du == NULL) {
    if (!sip_is_allowed(NH_PGET(sr->sr_owner, appl_method), SIP_METHOD_NOTIFY))
      return SR_STATUS(sr, 481, "Subscription Does Not Exist");

    solicited = 0;    /* Let application to handle unsolicited NOTIFY */
    du = nua_dialog_usage_add(sr->sr_owner, ds, nua_subscribe_usage, o);
    if (!du)
      return SR_STATUS1(sr, SIP_500_INTERNAL_SERVER_ERROR);
  }
  
  sr->sr_usage = du;
  eu = nua_dialog_usage_private(du); assert(eu);
  eu->eu_notified++;
  if (!o || !o->o_id) 
    eu->eu_no_id = 1;

  if (subs == NULL) {
    /* Compatibility */
    unsigned long delta = eu->eu_delta;
    if (sip->sip_expires) 
      delta = sip->sip_expires->ex_delta;

    if (delta == 0)
      substate = nua_substate_terminated, what = "terminated";
    else
      substate = nua_substate_active, what = "active";
  }
  else if (strcasecmp(subs->ss_substate, what = "terminated") == 0) {
    substate = nua_substate_terminated;
    reason = subs->ss_reason;

    if (str0casecmp(reason, "deactivated") == 0 ||
	str0casecmp(reason, "probation") == 0) 
      substate = nua_substate_embryonic;
  }
  else if (strcasecmp(subs->ss_substate, what = "pending") == 0) {
    substate = nua_substate_pending;
  }
  else /* if (strcasecmp(subs->ss_substate, what = "active") == 0) */ {
    /* Any extended state is considered as active */
    what = subs->ss_substate;
    substate = nua_substate_active;
  }

  eu->eu_substate = substate;
  if (!solicited)
    eu->eu_unsolicited = 1;

  SU_DEBUG_5(("nua(%p): %s: %s (%s)\n", 
	      (void *)sr->sr_owner, "nua_notify_server_preprocess",
	      what, reason ? reason : ""));

  if (solicited)
    return SR_STATUS1(sr, SIP_200_OK);

  return 0;
}


int nua_notify_server_report(nua_server_request_t *sr, tagi_t const *tags)
{
  nua_handle_t *nh = sr->sr_owner;
  nua_dialog_usage_t *du = sr->sr_usage;
  struct event_usage *eu = nua_dialog_usage_private(du);
  sip_t const *sip = sr->sr_request.sip;
  enum nua_substate substate = nua_substate_terminated;
  sip_time_t delta = SIP_TIME_MAX;
  sip_event_t const *o = sip->sip_event;
  int retry = -1;
  int retval;

  if (eu) {
    sip_subscription_state_t *subs = sip->sip_subscription_state;

    substate = eu->eu_substate;

    if (substate == nua_substate_active || substate == nua_substate_pending) {
      if (subs && subs->ss_expires) {
	sip_time_t now = sip_now();
	sip_time_t delta0 = strtoul(subs->ss_expires, NULL, 10);
	if (now + delta0 <= eu->eu_expires)
	  delta = delta0;
      }
    }
    else if (substate == nua_substate_embryonic) {
      if (subs && subs->ss_reason) {
	if (str0casecmp(subs->ss_reason, "deactivated") == 0) {
	  retry = 0;		/* retry immediately */
	} 
	else if (str0casecmp(subs->ss_reason, "probation") == 0) {
	  retry = 30;
	  if (subs->ss_retry_after)
	    retry = strtoul(subs->ss_retry_after, NULL, 10);
	  if (retry > 3600)
	    retry = 3600;
	}
      }
    }
    else if (substate == nua_substate_terminated) {
      sr->sr_terminating = 1;
    }
  }
  
  retval = nua_base_server_treport(sr, /* can destroy sr */
				   NUTAG_SUBSTATE(substate),
				   SIPTAG_EVENT(o),
				   TAG_NEXT(tags)); 

  if (retval != 1 || du == NULL)
    return retval;

  if (eu->eu_unsolicited) {
    /* Xyzzy */;
  }
  else if (retry >= 0) {		/* Try to subscribe again */
    /* XXX - this needs through testing */
    nua_dialog_remove(nh, nh->nh_ds, du); /* tear down */
    nua_dialog_usage_set_refresh_range(du, retry, retry + 5);
  }
  else {
    if (delta < SIP_TIME_MAX) {
      nua_dialog_usage_set_refresh(du, delta);
      eu->eu_expires = du->du_refquested + delta;
    }
  }

  return retval;
}


/* ======================================================================== */
/* REFER */

/**@fn void nua_refer(nua_handle_t *nh, tag_type_t tag, tag_value_t value, ...);
 *
 * Transfer a call. 
 * 
 * Send a REFER request asking the recipient to transfer the call. 
 *
 * The REFER request also establishes an implied subscription to the "refer"
 * event. The "refer" event can have an "id" parameter, which has the value
 * of CSeq number in the REFER request. After initiating the REFER request,
 * the nua engine sends application a #nua_r_refer event with status 100 and
 * tag NUTAG_REFER_EVENT() containing a matching event header with id
 * parameter.
 *
 * Note that the @Event header in the locally generated #nua_r_refer event
 * contains the @a id parameter. The @a id parameter contains the @CSeq
 * number of the REFER request, and it may get incremented if the request is
 * retried because it got challenged or redirected. In that case, the
 * application gets a new #nua_r_refer event with status 100 and tag
 * NUTAG_REFER_EVENT(). Also the recipient of the REFER request may or may
 * not include the @a id parameter with the @Event header in the NOTIFY
 * requests messages which it sends to the sender of the REFER request.
 *
 * Therefore the application is not able to modify the state of the implied
 * subscription before receiving the first NOTIFY request.
 *
 * @param nh              Pointer to operation handle
 * @param tag, value, ... List of tagged parameters
 *
 * @return 
 *    nothing
 *
 * @par Related Tags:
 *    NUTAG_URL() \n
 *    Tags of nua_set_hparams() \n
 *    Header tags defined in <sofia-sip/sip_tag.h>
 *
 * @par Events:
 *    #nua_r_refer \n
 *    #nua_i_notify
 *
 * @sa #nua_r_refer, NUTAG_SUBSTATE(), NUTAG_REFER_EVENT(),#nua_i_refer,
 * @RFC3515, @ReferTo, SIPTAG_REFER_TO(), SIPTAG_REFER_TO_STR(),
 * @RFC3892, @ReferredBy, SIPTAG_REFERRED_BY(), SIPTAG_REFERRED_BY_STR(),
 * @RFC3891, @Replaces, SIPTAG_REPLACES(), SIPTAG_REPLACES_STR(),
 * @RFC4488, @ReferSub, SIPTAG_REFER_SUB(), SIPTAG_REFER_SUB_STR()
 */

/**@NUA_EVENT nua_r_refer
 *
 * @brief Response to outgoing REFER.
 *
 * @param status response status code
 *               (if the request is retried, @a status is 100, the @a
 *               sip->sip_status->st_status contain the real status code
 *               from the response message, e.g., 302, 401, or 407)
 * @param phrase a short textual description of @a status code
 * @param nh     operation handle associated with the REFER request
 * @param hmagic application context associated with the handle
 * @param sip    response to REFER request or NULL upon an error
 *               (status code is in @a status and 
 *                descriptive message in @a phrase parameters)
 * @param tags    NUTAG_REFER_EVENT() \n
 *                NUTAG_SUBSTATE()
 *
 * @sa nua_refer(), NUTAG_SUBSTATE(), #nua_i_refer,
 * @RFC3515, @RFC4488, @ReferSub
 *
 * @END_NUA_EVENT
 */

static int nua_refer_client_init(nua_client_request_t *cr, 
				 msg_t *, sip_t *,
				 tagi_t const *tags);
static int nua_refer_client_request(nua_client_request_t *cr,
				    msg_t *, sip_t *,
				    tagi_t const *tags);
static int nua_refer_client_response(nua_client_request_t *cr,
				     int status, char const *phrase,
				     sip_t const *sip);

static nua_client_methods_t const nua_refer_client_methods = {
  SIP_METHOD_REFER,		/* crm_method, crm_method_name */
  0,				/* crm_extra */
  {				/* crm_flags */
    /* create_dialog */ 1,
    /* in_dialog */ 1,
    /* target refresh */ 1
  },
  NULL,				/* crm_template */
  nua_refer_client_init,	/* crm_init */
  nua_refer_client_request,	/* crm_send */
  NULL,				/* crm_check_restart */
  nua_refer_client_response,	/* crm_recv */
  nua_refer_client_response,	/* crm_preliminary */
  NULL,				/* crm_report */
  NULL,				/* crm_complete */
};

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

static int nua_refer_client_init(nua_client_request_t *cr,
				 msg_t *msg, sip_t *sip,
				 tagi_t const *tags)
{
  nua_handle_t *nh = cr->cr_owner;

  if (sip->sip_referred_by == NULL) {
    sip_from_t *a = sip->sip_from;
    sip_referred_by_t by[1];

    sip_referred_by_init(by);

    if (a == NULL)
      a = nh->nh_nua->nua_from;
    by->b_display = a->a_display;
    *by->b_url = *a->a_url;

    sip_add_dup(msg, sip, (sip_header_t *)by);
  }

  if (sip->sip_event)
    sip_header_remove(msg, sip, (sip_header_t *)sip->sip_event);

  return 0;
}

static int nua_refer_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, *du0 = cr->cr_usage;
  struct event_usage *eu;
  sip_event_t *event;
  int error;

  cr->cr_usage = NULL;

  event = sip_event_format(nh->nh_home, "refer;id=%u", sip->sip_cseq->cs_seq);
  if (!event)
    return -1;

  if (du0 == NULL ||
      du0->du_event == NULL ||
      du0->du_event->o_id == NULL ||
      strcmp(du0->du_event->o_id, event->o_id)) {
    du = nua_dialog_usage_add(nh, nh->nh_ds, nua_subscribe_usage, event);
    if (!du)
      return -1;
  }
  else {
    du = du0, du0 = NULL;
  }

  if (du0)
    nua_dialog_usage_remove(nh, nh->nh_ds, du0, NULL, NULL);

  eu = nua_dialog_usage_private(cr->cr_usage = du);
  eu ->eu_refer = 1;

  error = nua_base_client_request(cr, msg, sip, tags);

  if (!error) {
    /* Give application an Event header for matching NOTIFYs with REFER */
    nua_stack_tevent(nh->nh_nua, nh, NULL,
		     cr->cr_event, SIP_100_TRYING,
		     NUTAG_REFER_EVENT(event),
		     SIPTAG_EVENT(event),
		     TAG_END());
    su_free(nh->nh_home, event);
  }

  return error;
}

static int nua_refer_client_response(nua_client_request_t *cr,
				     int status, char const *phrase,
				     sip_t const *sip)
{
  nua_dialog_usage_t *du = cr->cr_usage; 
  enum nua_substate substate = nua_substate_terminated;

  if (du) {
    struct event_usage *eu = nua_dialog_usage_private(du);

    if (status < 200) {
      substate = eu->eu_substate;      
    } 
    else if (status < 300) {
      sip_refer_sub_t const *rs = sip_refer_sub(sip);

      if (rs && strcasecmp("false", rs->rs_value) == 0)
	cr->cr_terminated = 1;

      if (!cr->cr_terminated)
	substate = eu->eu_substate;
    }
  }
  
  return nua_base_client_tresponse(cr, status, phrase, sip, 
				   NUTAG_SUBSTATE(substate),
				   SIPTAG_EVENT(du ? du->du_event : NULL),
				   TAG_END());
}