nta.c

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

    agent_set_params(agent, ta_args(ta));

    if (agent->sa_mclass == NULL)
      agent->sa_mclass = sip_default_mclass();

    agent->sa_in.re_t1 = &agent->sa_in.re_list;
    
    incoming_queue_init(agent->sa_in.proceeding, 0);
    incoming_queue_init(agent->sa_in.preliminary, agent->sa_t1x64); /* P1 */
    incoming_queue_init(agent->sa_in.inv_completed, agent->sa_t1x64); /* H */
    incoming_queue_init(agent->sa_in.inv_confirmed, agent->sa_t4); /* I */
    incoming_queue_init(agent->sa_in.completed, agent->sa_t1x64); /* J */
    incoming_queue_init(agent->sa_in.terminated, 0);
    incoming_queue_init(agent->sa_in.final_failed, 0); 

    agent->sa_out.re_t1 = &agent->sa_out.re_list;

    outgoing_queue_init(agent->sa_out.delayed, 0);
    outgoing_queue_init(agent->sa_out.resolving, 0);
    outgoing_queue_init(agent->sa_out.trying, agent->sa_t1x64); /* F */
    outgoing_queue_init(agent->sa_out.completed, agent->sa_t4); /* K */
    outgoing_queue_init(agent->sa_out.terminated, 0); 
    /* Special queues (states) for outgoing INVITE transactions */
    outgoing_queue_init(agent->sa_out.inv_calling, agent->sa_t1x64); /* B */
    timer_c = (agent->sa_use_timer_c || !agent->sa_is_a_uas)
      ? agent->sa_timer_c : 0;
    outgoing_queue_init(agent->sa_out.inv_proceeding, timer_c); /* C */
    outgoing_queue_init(agent->sa_out.inv_completed, 32000); /* Timer D */

    if (leg_htable_resize(agent->sa_home, agent->sa_dialogs, 0) < 0 ||
	leg_htable_resize(agent->sa_home, agent->sa_defaults, 0) < 0 ||
	outgoing_htable_resize(agent->sa_home, agent->sa_outgoing, 0) < 0 ||
	incoming_htable_resize(agent->sa_home, agent->sa_incoming, 0) < 0) {
      SU_DEBUG_0(("nta_agent_create: failure with %s\n", "hash tables"));
      goto deinit;
    }
    SU_DEBUG_9(("nta_agent_create: initialized %s\n", "hash tables"));

    if (contact_url != (url_string_t *)-1 &&
	nta_agent_add_tport(agent, contact_url, ta_tags(ta)) < 0) {
      SU_DEBUG_7(("nta_agent_create: failure with %s\n", "transport"));
      goto deinit;
    }
    SU_DEBUG_9(("nta_agent_create: initialized %s\n", "transports"));

    if (agent_tag_init(agent) < 0) {
      SU_DEBUG_3(("nta_agent_create: failure with %s\n", "random identifiers"));
      goto deinit;
    }
    SU_DEBUG_9(("nta_agent_create: initialized %s\n", "random identifiers"));

    if (agent_timer_init(agent) < 0) {
      SU_DEBUG_0(("nta_agent_create: failure with %s\n", "timer"));
      goto deinit;
    }
    SU_DEBUG_9(("nta_agent_create: initialized %s\n", "timer"));

    if (agent_launch_terminator(agent) == 0)
      SU_DEBUG_9(("nta_agent_create: initialized %s\n", "threads"));

#if HAVE_SOFIA_SRESOLV
    agent->sa_resolver = sres_resolver_create(root, NULL, ta_tags(ta));
    if (!agent->sa_resolver) {
      SU_DEBUG_0(("nta_agent_create: failure with %s\n", "resolver"));
    }
    SU_DEBUG_9(("nta_agent_create: initialized %s\n", "resolver"));
#endif

    ta_end(ta);

    return agent;

  deinit:
    nta_agent_destroy(agent);
  }

  ta_end(ta);

  return NULL;
}

/**
 * Destroy an NTA agent object.
 *
 * @param agent the NTA agent object to be destroyed.
 *
 */
void nta_agent_destroy(nta_agent_t *agent)
{
  if (agent) {
    size_t i;
    outgoing_htable_t *oht = agent->sa_outgoing;
    incoming_htable_t *iht = agent->sa_incoming;
    /* Currently, this is pretty pointless, as legs don't keep any resources */
    leg_htable_t *lht;
    nta_leg_t *leg;

    for (i = 0, lht = agent->sa_dialogs; i < lht->lht_size; i++) {
      if ((leg = lht->lht_table[i])) {
	SU_DEBUG_3(("nta_agent_destroy: destroying dialog with <"
		    URL_PRINT_FORMAT ">\n",
		    URL_PRINT_ARGS(leg->leg_remote->a_url)));
	leg_free(agent, leg);
      }
    }

    for (i = 0, lht = agent->sa_defaults; i < lht->lht_size; i++) {
      if ((leg = lht->lht_table[i])) {
	SU_DEBUG_3(("%s: destroying leg for <" 
		    URL_PRINT_FORMAT ">\n",
		    __func__, URL_PRINT_ARGS(leg->leg_url)));
	leg_free(agent, leg);
      }
    }

    if (agent->sa_default_leg)
      leg_free(agent, agent->sa_default_leg);

    for (i = iht->iht_size; i-- > 0; )
      while (iht->iht_table[i]) {
	nta_incoming_t *irq = iht->iht_table[i];

	if (!irq->irq_destroyed)
	  SU_DEBUG_3(("%s: destroying %s server transaction from <"
		      URL_PRINT_FORMAT ">\n",
		      __func__, irq->irq_rq->rq_method_name,
		      URL_PRINT_ARGS(irq->irq_from->a_url)));

	incoming_free(irq);
      }

    for (i = oht->oht_size; i-- > 0;)
      while (oht->oht_table[i]) {
	nta_outgoing_t *orq = oht->oht_table[i];

	if (!orq->orq_destroyed)
	  SU_DEBUG_3(("%s: destroying %s client transaction to <"
		      URL_PRINT_FORMAT ">\n",
		      __func__, orq->orq_method_name,
		      URL_PRINT_ARGS(orq->orq_to->a_url)));

	outgoing_free(orq);
      }

    su_timer_destroy(agent->sa_timer), agent->sa_timer = NULL;

#   if HAVE_SOFIA_SRESOLV
    sres_resolver_destroy(agent->sa_resolver), agent->sa_resolver = NULL;
#   endif

    tport_destroy(agent->sa_tports), agent->sa_tports = NULL;

    agent_kill_terminator(agent);

    su_home_unref(agent->sa_home);
  }
}

/** Return agent context. */
nta_agent_magic_t *nta_agent_magic(nta_agent_t const *agent)
{
  return agent ? agent->sa_magic : NULL;
}

/** Return @Contact header.
 *
 * Get a @Contact header, which can be used to reach @a agent.
 *
 * @param agent NTA agent object
 *
 * User agents can insert the @Contact header in the outgoing REGISTER,
 * INVITE, and ACK requests and replies to incoming INVITE and OPTIONS
 * transactions.
 *
 * Proxies can use the @Contact header to create appropriate @RecordRoute
 * headers:
 * @code
 * r_r = sip_record_route_create(msg_home(msg),
 *	 			 sip->sip_request->rq_url,
 *				 contact->m_url);
 * @endcode
 *
 * @return A sip_contact_t object corresponding to the @a agent.
 */
sip_contact_t *nta_agent_contact(nta_agent_t const *agent)
{
  return agent ? agent->sa_contact : NULL;
}

/** Return a list of @Via headers.
 *
 * Get @Via headers for all activated transport.
 *
 * @param agent NTA agent object
 *
 * @return A list of #sip_via_t objects used by the @a agent.
 */
sip_via_t *nta_agent_via(nta_agent_t const *agent)
{
  return agent ? agent->sa_vias : NULL;
}

/** Return a list of public (UPnP, STUN) @Via headers.
 *
 * Get public @Via headers for all activated transports.
 *
 * @param agent NTA agent object
 *
 * @return A list of #sip_via_t objects used by the @a agent.
 */
sip_via_t *nta_agent_public_via(nta_agent_t const *agent)
{
  return agent ? agent->sa_public_vias : NULL;
}

/** Match a @Via header @a v with @Via headers in @a agent.
 *
 */
static
sip_via_t *agent_has_via(nta_agent_t const *agent, sip_via_t const *via)
{
  sip_via_t const *v;

  for (v = agent->sa_public_vias; v; v = v->v_next) {
    if (strcasecmp(via->v_host, v->v_host))
      continue;
    if (str0cmp(via->v_port, v->v_port))
      continue;
    if (strcasecmp(via->v_protocol, v->v_protocol))
      continue;
    return (sip_via_t *)v;
  }

  for (v = agent->sa_vias; v; v = v->v_next) {
    if (strcasecmp(via->v_host, v->v_host))
      continue;
    if (str0cmp(via->v_port, v->v_port))
      continue;
    if (strcasecmp(via->v_protocol, v->v_protocol))
      continue;
    return (sip_via_t *)v;
  }

  return NULL;
}

/** Return @UserAgent header.
 *
 * Get @UserAgent information with NTA version.
 *
 * @param agent NTA agent object (may be NULL)
 *
 * @return A string containing the @a agent version.
 */
char const *nta_agent_version(nta_agent_t const *agent)
{
  return "nta" "/" VERSION;
}

/** Initialize default tag */
static int agent_tag_init(nta_agent_t *self)
{
  sip_contact_t *m = self->sa_contact;
  uint32_t hash = 1;

  if (m) {

    if (m->m_url->url_user)
      hash = 914715421U * hash + msg_hash_string(m->m_url->url_user);
    if (m->m_url->url_host)
      hash = 914715421U * hash + msg_hash_string(m->m_url->url_host);
    if (m->m_url->url_port)
      hash = 914715421U * hash + msg_hash_string(m->m_url->url_port);
    if (m->m_url->url_params)
      hash = 914715421U * hash + msg_hash_string(m->m_url->url_params);
  }

  if (hash == 0)
    hash = 914715421U;

  self->sa_branch = NTA_BRANCH_PRIME * su_ntp_now();
  self->sa_branch *= hash;

  self->sa_tags = NTA_TAG_PRIME * self->sa_branch;

  return 0;
}

/** Initialize agent timer. */
static
int agent_timer_init(nta_agent_t *agent)
{
  agent->sa_timer = su_timer_create(su_root_task(agent->sa_root),
				    NTA_SIP_T1 / 8);
#if 0
  return su_timer_set(agent->sa_timer,
		      agent_timer,
		      agent);
#endif
  return -(agent->sa_timer == NULL);
}

/**
 * Agent timer routine.
 */
static
void agent_timer(su_root_magic_t *rm, su_timer_t *timer, nta_agent_t *agent)
{
  su_time_t stamp = su_now();
  uint32_t now = su_time_ms(stamp), next, latest;

  now += now == 0;

  agent->sa_next = 0;

  agent->sa_now = stamp;
  agent->sa_millisec = now;
  agent->sa_in_timer = 1;

  outgoing_timer(agent);
  incoming_timer(agent);

  /* agent->sa_now is used only if sa_millisec != 0 */
  agent->sa_millisec = 0;
  agent->sa_in_timer = 0;

  /* Calculate next timeout */
  next = latest = now + NTA_TIME_MAX + 1;

#define NEXT_TIMEOUT(next, p, f, now) \
  (void)(p && (int32_t)(p->f - (next)) < 0 && \
	 ((next) = ((int32_t)(p->f - (now)) > 0 ? p->f : (now))))

  NEXT_TIMEOUT(next, agent->sa_out.re_list, orq_retry, now);
  NEXT_TIMEOUT(next, agent->sa_out.inv_completed->q_head, orq_timeout, now);
  NEXT_TIMEOUT(next, agent->sa_out.completed->q_head, orq_timeout, now);
  NEXT_TIMEOUT(next, agent->sa_out.inv_calling->q_head, orq_timeout, now);
  if (agent->sa_out.inv_proceeding->q_timeout)
    NEXT_TIMEOUT(next, agent->sa_out.inv_proceeding->q_head, orq_timeout, now);
  NEXT_TIMEOUT(next, agent->sa_out.trying->q_head, orq_timeout, now);

  NEXT_TIMEOUT(next, agent->sa_in.preliminary->q_head, irq_timeout, now);
  NEXT_TIMEOUT(next, agent->sa_in.inv_completed->q_head, irq_timeout, now);
  NEXT_TIMEOUT(next, agent->sa_in.inv_confirmed->q_head, irq_timeout, now);
  NEXT_TIMEOUT(next, agent->sa_in.completed->q_head, irq_timeout, now);
  NEXT_TIMEOUT(next, agent->sa_in.re_list, irq_retry, now);

  if (agent->sa_next)
    NEXT_TIMEOUT(next, agent, sa_next, now);

#undef NEXT_TIMEOUT

  if (next == latest) {
    /* Do not set timer? */
    SU_DEBUG_9(("nta: timer not set\n"));
    assert(!agent->sa_out.completed->q_head);
    assert(!agent->sa_out.trying->q_head);
    assert(!agent->sa_out.inv_calling->q_head);
    assert(!agent->sa_out.re_list);
    assert(!agent->sa_in.inv_confirmed->q_head);
    assert(!agent->sa_in.preliminary->q_head);
    assert(!agent->sa_in.completed->q_head);
    assert(!agent->sa_in.inv_completed->q_head);
    assert(!agent->sa_in.re_list);
    return;
  }

  if (next == now) if (++next == 0) ++next;

  SU_DEBUG_9(("nta: timer %s to %ld ms\n", "set next", (long)(next - now)));

  agent->sa_next = next;

  su_timer_set_at(timer, agent_timer, agent, su_time_add(stamp, next - now));
}

/** Add uin32_t milliseconds to the time. */
static su_time_t add_milliseconds(su_time_t t0, uint32_t ms)
{
  unsigned long sec = ms / 1000, usec = (ms % 1000) * 1000;

  t0.tv_usec += usec;
  t0.tv_sec += sec;

  if (t0.tv_usec >= 1000000) {
    t0.tv_sec += 1;
    t0.tv_usec -= 1000000;
  }

  return t0;
}

/** Calculate nonzero value for timeout.
 *
 * Sets or adjusts agent timer when needed.
 *
 * @retval 0 if offset is 0
 * @retval timeout (millisecond counter) otherwise
 */
static
uint32_t set_timeout(nta_agent_t *agent, uint32_t offset)
{
  su_time_t now;
  uint32_t next, ms;

  if (offset == 0)
    return 0;

  if (agent->sa_millisec) /* Avoid expensive call to su_now() */
    now = agent->sa_now, ms = agent->sa_millisec;
  else
    now = su_now(), ms = su_time_ms(now);
  
  next = ms + offset; if (next == 0) next = 1;

  if (agent->sa_in_timer)	/* Currently executing timer */
    return next;

  if (agent->sa_next == 0 || (int32_t)(agent->sa_next - next - 5L) > 0) {
    /* Set timer */
    if (agent->sa_next)
      SU_DEBUG_9(("nta: timer %s to %ld ms\n", "shortened", (long)offset));
    else
      SU_DEBUG_9(("nta: timer %s to %ld ms\n", "set", (long)offset));
      
    su_timer_set_at(agent->sa_timer, agent_timer, agent, 
		    add_milliseconds(now, offset));
    agent->sa_next = next;
  }

  return next;