nua_stack.c

sip协议栈

    if (!ds->ds_remote)
      ds->ds_remote = sip_to_dup(nh->nh_home, sip->sip_to);
    if (!ds->ds_local)
      ds->ds_local = sip_from_dup(nh->nh_home, sip->sip_from);

    if (copy) {
      cr->cr_msg = msg;
      msg = msg_copy(msg);
    }
  }

  return msg;

 error:
  ta_end(ta);
  msg_destroy(msg);
  return NULL;
}

/**@internal
 * Create a response message.
 *
 * @param nua
 * @param nh
 * @param irq
 * @param status
 * @param phrase
 * @param tag, value, ... list of tag-value pairs
 */
msg_t *nh_make_response(nua_t *nua, nua_handle_t *nh,
			nta_incoming_t *irq,
			int status, char const *phrase,
			tag_type_t tag, tag_value_t value, ...)
{
  ta_list ta;
  msg_t *msg = nta_msg_create(nua->nua_nta, 0);
  sip_t *sip = sip_object(msg);
  tagi_t const *t;

  ta_start(ta, tag, value);

  if (!msg)
    return NULL;
  else if (nta_msg_response_complete(msg, irq, status, phrase) < 0)
    msg_destroy(msg);
  else if (sip_add_tl(msg, sip, ta_tags(ta)) < 0)
    msg_destroy(msg);
  else if (sip_complete_message(msg) < 0)
    msg_destroy(msg);
  else if (!sip->sip_supported && NH_PGET(nh, supported) &&
	   sip_add_dup(msg, sip, (sip_header_t *)NH_PGET(nh, supported)) < 0)
    msg_destroy(msg);
  else if (!sip->sip_user_agent && NH_PGET(nh, user_agent) &&
	   sip_add_dup(msg, sip, (sip_header_t *)NH_PGET(nh, user_agent)) < 0)
    msg_destroy(msg);
  else if (!sip->sip_organization && NH_PGET(nh, organization) &&
	   sip_add_dup(msg, sip, (sip_header_t *)NH_PGET(nh, organization)) < 0)
    msg_destroy(msg);
  else if (!sip->sip_allow && NH_PGET(nh, allow) &&
	   sip_add_dup(msg, sip, (sip_header_t*)NH_PGET(nh, allow)) < 0)
    msg_destroy(msg);
  else if (!sip->sip_contact &&
	   (t = tl_find(ta_args(ta), _nutag_add_contact)) &&
	   nua_registration_add_contact(nh, msg, sip, t->t_value, 0) < 0)
    msg_destroy(msg);
  else
    return msg;

  return NULL;
}


/* ======================================================================== */
/* Generic processing */

int nua_stack_process_unknown(nua_t *nua,
			      nua_handle_t *nh,
			      nta_incoming_t *irq,
			      sip_t const *sip)
{
  return 501;
}

int
nua_stack_method(nua_t *nua, nua_handle_t *nh, nua_event_t e,
		 tagi_t const *tags)
{
  return UA_EVENT1(e, SIP_501_NOT_IMPLEMENTED);
}

/**@internal
 * Relay response message to the application.
 *
 * If handle has already been marked as destroyed by nua_handle_destroy(),
 * release the handle with nh_destroy().
 */
int nua_stack_process_response(nua_handle_t *nh,
			       struct nua_client_request *cr,
			       nta_outgoing_t *orq,
			       sip_t const *sip,
			       tag_type_t tag, tag_value_t value, ...)
{
  msg_t *msg = nta_outgoing_getresponse(orq);
  int status = sip->sip_status->st_status;
  char const *phrase = sip->sip_status->st_phrase;
  ta_list ta;
  int final;

  if (status >= 200 && status < 300)
    nh_challenge(nh, sip);  /* Collect nextnonce */

  if (nta_outgoing_method(orq) == sip_method_invite)
    final = status >= 300;
  else
    final = status >= 200;

  if (final) {
    nua_creq_deinit(cr, orq);

    if (cr->cr_usage && nh->nh_cr == cr) {
      if ((status >= 300 && !cr->cr_usage->du_ready) ||
	  cr->cr_usage->du_terminating)
	nua_dialog_usage_remove(nh, nh->nh_ds, cr->cr_usage);
    }

    cr->cr_usage = NULL;
  }

  ta_start(ta, tag, value);

  nua_stack_event(nh->nh_nua, nh, msg, cr->cr_event, status, phrase,
		  ta_tags(ta));

  if (final)
    cr->cr_event = nua_i_error;

  ta_end(ta);

  return 0;
}

static 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;
}

int nua_creq_restart_with(nua_handle_t *nh,
			  struct nua_client_request *cr,
			  nta_outgoing_t *orq,
			  int status, char const *phrase,
			  nua_creq_restart_f *f,
			  TAG_LIST)
{
  ta_list ta;
  msg_t *msg = nta_outgoing_getresponse(orq);

  nua_stack_event(nh->nh_nua, nh, msg, cr->cr_event, status, phrase,
		  TAG_END());

  nta_outgoing_destroy(orq);

  if (f) {
    ta_start(ta, tag, value);
    f(nh, ta_args(ta));
    ta_end(ta);
  }

  return 1;
}


/** @internal Save operation until it can be restarted */
int nua_creq_save_restart(nua_handle_t *nh,
			  struct nua_client_request *cr,
			  nta_outgoing_t *orq,
			  int status, char const *phrase,
			  nua_creq_restart_f *restart_function)
{
  nua_dialog_usage_t *du = cr->cr_usage;
  msg_t *msg = nta_outgoing_getresponse(orq);

  nua_stack_event(nh->nh_nua, nh, msg, cr->cr_event,
		  status, phrase, 
		  TAG_END());
  nta_outgoing_destroy(orq);

  if (du) {
    du->du_pending = NULL;
    du->du_refresh = 0;
  }

  cr->cr_restart = restart_function;
  return 1;
}


/**@internal
 * Check response, return true if we can restart the request.
 *
 */
int nua_creq_check_restart(nua_handle_t *nh,
			   struct nua_client_request *cr,
			   nta_outgoing_t *orq,
			   sip_t const *sip,
			   nua_creq_restart_f *restart_function)
{
  int status = sip->sip_status->st_status;
  sip_method_t method = nta_outgoing_method(orq);
  int removed = 0;

  nua_dialog_usage_t *du = cr->cr_usage;

  assert(restart_function);

  if (orq == cr->cr_orq)
    removed = 1, cr->cr_orq = NULL;

  cr->cr_restart = NULL;

  if (cr->cr_msg == NULL || status < 200)
    ;
  else if (++cr->cr_retry_count > NH_PGET(nh, retry_count))
    ;
  else if (status == 302) {
    if (can_redirect(sip->sip_contact, method)) {
      return
	nua_creq_restart_with(nh, cr, orq, 100, "Redirected",
			      restart_function,
			      NUTAG_URL(sip->sip_contact->m_url),
			      TAG_END());
    }
  }
  else if (status == 423) {
    sip_t *req = sip_object(cr->cr_msg);
    unsigned my_expires = 0;

    if (req->sip_expires)
      my_expires = req->sip_expires->ex_delta;

    if (sip->sip_min_expires &&
	sip->sip_min_expires->me_delta > my_expires) {
      sip_expires_t ex[1];
      sip_expires_init(ex);
      ex->ex_delta = sip->sip_min_expires->me_delta;

      return
	nua_creq_restart_with(nh, cr, orq,
			      100, "Re-Negotiating Subscription Expiration",
			      restart_function, 
			      SIPTAG_EXPIRES(ex),
			      TAG_END());
    }
  }
  else if (method != sip_method_ack && method != sip_method_cancel &&
	   ((status == 401 && sip->sip_www_authenticate) ||
	    (status == 407 && sip->sip_proxy_authenticate)) &&
	   nh_challenge(nh, sip) > 0) {
    msg_t *request = nta_outgoing_getrequest(orq);
    sip_t *rsip = sip_object(request);
    int done;

    /* XXX - check for instant restart */
    done = auc_authorization(&nh->nh_auth, cr->cr_msg, (msg_pub_t*)NULL,
			     rsip->sip_request->rq_method_name,
			     rsip->sip_request->rq_url,
			     rsip->sip_payload);

    msg_destroy(request);

    if (done > 0) {
      return
	nua_creq_restart_with(nh, cr, orq,
			      100, "Request Authorized by Cache",
			      restart_function, TAG_END());
    }
    else if (done == 0) {
      /* Operation waits for application to call nua_authenticate() */
      return nua_creq_save_restart(nh, cr, orq, 
				   status, sip->sip_status->st_phrase, 
				   restart_function);
    }
    else {
      SU_DEBUG_5(("nua(%p): auc_authorization failed\n", nh));
    }
  }
#if HAVE_SOFIA_SMIME
  else if (status == 493)     /* try detached signature */
    ;
#endif
  else if (status == 422 && method == sip_method_invite) {
    if (sip->sip_min_se && nh->nh_ss->ss_min_se < sip->sip_min_se->min_delta)
      nh->nh_ss->ss_min_se = sip->sip_min_se->min_delta;
    if (nh->nh_ss->ss_min_se > nh->nh_ss->ss_session_timer)
      nh->nh_ss->ss_session_timer = nh->nh_ss->ss_min_se;

    return
      nua_creq_restart_with(nh, cr, orq,
			    100, "Re-Negotiating Session Timer",
			    restart_function, TAG_END());
  }

  /* This was final response that cannot be restarted. */
  if (removed)
    cr->cr_orq = orq;

  if (du) {
    du->du_pending = NULL;
    du->du_refresh = 0;
  }

  cr->cr_retry_count = 0;

  if (cr->cr_msg)
    msg_destroy(cr->cr_msg), cr->cr_msg = NULL;

  return 0;
}

/** @internal Restart a request */
int nua_creq_restart(nua_handle_t *nh,
		     struct nua_client_request *cr,
		     nta_response_f *cb,
		     tagi_t *tags)
{
  msg_t *msg;

  cr->cr_restart = NULL;

  if (!cr->cr_msg)
    return 0;

  msg = nua_creq_msg(nh->nh_nua, nh, cr, 1, SIP_METHOD_UNKNOWN,
		     TAG_NEXT(tags));

  cr->cr_orq = nta_outgoing_mcreate(nh->nh_nua->nua_nta, cb, nh, NULL, msg,
				    SIPTAG_END(), TAG_NEXT(tags));

  if (!cr->cr_orq) {
    msg_destroy(msg);
    return 0;
  }

  return 1;
}

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

void
nua_stack_authenticate(nua_t *nua, nua_handle_t *nh, nua_event_t e,
		       tagi_t const *tags)
{
  int status = nh_authorize(nh, TAG_NEXT(tags));

  if (status > 0) {
    nua_creq_restart_f *restart = NULL;

    nua_stack_event(nua, nh, NULL, e, SIP_200_OK, TAG_END());

    if (nh->nh_cr->cr_restart) {
      restart = nh->nh_cr->cr_restart;
      nh->nh_cr->cr_restart = NULL;
    }
    else if (nh->nh_ss->ss_crequest->cr_restart) {
      restart = nh->nh_ss->ss_crequest->cr_restart;
      nh->nh_ss->ss_crequest->cr_restart = NULL;
    }

    if (restart)
      restart(nh, (tagi_t *)tags);	/* Restart operation */
  }
  else if (status < 0) {
    nua_stack_event(nua, nh, NULL, e, 500, "Cannot add credentials", TAG_END());
  }
  else {
    nua_stack_event(nua, nh, NULL, e, 404, "No matching challenge", TAG_END());
  }
}

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

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;
  sip_user_agent_t 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 (nta_check_method(irq, sip, allow,
		       SIPTAG_SUPPORTED(supported),
		       SIPTAG_USER_AGENT(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, SIP_416_UNSUPPORTED_URI,
			SIPTAG_ALLOW(allow),
			SIPTAG_SUPPORTED(supported),
			SIPTAG_USER_AGENT(user_agent),
			TAG_END());
  }

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

  if (nh == nua->nua_dhandle) {
    if (!sip->sip_to->a_tag)
      ;
    else if (method == sip_method_message && NH_PGET(nh, win_messenger_enable))
      ;
    else {
      nta_incoming_treply(irq, 481, "Initial transaction with a To tag",
			  TAG_END());
      return 481;
    }
    nh = NULL;
  }

  if (sip->sip_timestamp)
    nta_incoming_treply(irq, SIP_100_TRYING, TAG_END());

  switch (method) {
  case sip_method_invite:
    return nua_stack_process_invite(nua, nh, irq, sip);

  case sip_method_info:
    if (nh) return nua_stack_process_info(nua, nh, irq, sip);
    /*FALLTHROUGH*/

  case sip_method_update:
    if (nh) return nua_stack_process_update(nua, nh, irq, sip);
    /*FALLTHROUGH*/

  case sip_method_bye:
    if (nh) return nua_stack_process_bye(nua, nh, irq, sip);

    nta_incoming_treply(irq,
			481, "Call Does Not Exist",
			SIPTAG_ALLOW(allow),
			SIPTAG_SUPPORTED(supported),
			SIPTAG_USER_AGENT(user_agent),
			TAG_END());
    return 481;

  case sip_method_message:
    return nua_stack_process_message(nua, nh, irq, sip);

  case sip_method_notify:
    return nua_stack_process_notify(nua, nh, irq, sip);

  case sip_method_subscribe:
    return nua_stack_process_subsribe(nua, nh, irq, sip);

  case sip_method_options:
    return nua_stack_process_options(nua, nh, irq, sip);

  case sip_method_refer:
    return nua_stack_process_refer(nua, nh, irq, sip);

  case sip_method_publish:
    return nua_stack_process_publish(nua, nh, irq, sip);

  case sip_method_ack:
  case sip_method_cancel:
    SU_DEBUG_1(("nua(%p): strange %s from <" URL_PRINT_FORMAT ">\n", nh,
		sip->sip_request->rq_method_name,
		URL_PRINT_ARGS(sip->sip_from->a_url)));
    /* Send nua_i_error ? */
    return 481;

  default:
    return nua_stack_process_unknown(nua, nh, irq, sip);
  }
}

void
nua_stack_respond(nua_t *nua, nua_handle_t *nh,
	   int status, char const *phrase, tagi_t const *tags)
{
  struct nua_session_state *ss = nh->nh_ss;
  nua_server_request_t *sr = ss->ss_srequest;

  if (sr->sr_respond) {
    sr->sr_respond(nua, nh, status, phrase, tags);
  }
#if 0
  else if (nta_incoming_status(nh->nh_irq) < 200) {
    int add_contact = 0;
    sip_contact_t *m;

    if (nta_incoming_url(nh->nh_irq)->url_type == url_sips &&
	nua->nua_sips_contact)
      m = nua->nua_sips_contact;
    else
      m = nua->nua_contact;

    SU_DEBUG_1(("nua: anonymous response %u %s\n", status, phrase));

    tl_gets(tags, NUTAG_ADD_CONTACT_REF(add_contact), TAG_END());
    nta_incoming_treply(nh->nh_irq, status, phrase,
			TAG_IF(add_contact, SIPTAG_CONTACT(m)),
			TAG_NEXT(tags));
    if (status >= 200)
      nta_incoming_destroy(nh->nh_irq), nh->nh_irq = NULL;
  }
#endif

  else if (ss->ss_srequest->sr_irq) {
    nua_stack_event(nua, nh, NULL, nua_i_error,
		    500, "Already Sent Final Response", TAG_END());
  }
  else {
    nua_stack_event(nua, nh, NULL, nua_i_error,
		    500, "Responding to a Non-Existing Request", TAG_END());
  }
}