nta.c

Internet Phone, Chat, Conferencing

 * ;transport=<xxx>
 * ;maddr=<actual addr>
 * ;comp=sigcomp
 * @endcode
 *
 * The scheme part determines which transports are used. "sip" implies UDP
 * and TCP, "sips" TLS over TCP. In the future, more transports can be
 * supported, for instance, "sip" can use SCTP or DCCP, "sips" DTLS or TLS
 * over SCTP.
 *
 * The "host" part determines what address/domain name is used in Contact.
 * An "*" in "host" part is shorthand for any local IP address. 0.0.0.0
 * means that the only the IPv4 addresses are used. [::] means that only
 * the IPv6 addresses are used. If a domain name or a specific IP address
 * is given as "host" part, an additional "maddr" parameter can be used to
 * control which addresses are used by the stack when binding listen
 * sockets for incoming requests.
 *
 * The "port" determines what port is used in contact, and to which port the
 * stack binds in order to listen for incoming requests. Empty or missing
 * port means that default port should be used (5060 for sip, 5061 for
 * sips). An "*" in "port" part means any port, i.e., the stack binds to an
 * ephemeral port.
 *
 * The "transport" parameter determines the transport protocol that is used
 * and how they are preferred. If no protocol is specified, both UDP and TCP
 * are used for SIP URL and TLS for SIPS URL. The preference can be
 * indicated with a comma-separated list of transports, for instance,
 * parameter @code transport=tcp,udp @endocde indicates that TCP is
 * preferred to UDP.
 *
 * The "maddr" parameter determines to which address the stack binds in
 * order to listen for incoming requests. An "*" in "maddr" parameter is
 * shorthand for any local IP address. 0.0.0.0 means that only IPv4 sockets
 * are created. [::] means that only IPv6 sockets are created.
 *
 * The "comp" parameter determines the supported compression protocol.
 * Currently only sigcomp is supported (with suitable library.
 *
 * @par Examples:
 * @code sip:172.21.40.24;maddr=* @endcode \n
 * @code sip:172.21.40.24:50600;transport=TCP,UDP;comp=sigcomp @endcode \n
 * @code sips:* @endcode
 *
 * @return
 * On success, zero is returned. On error, -1 is returned, and @a errno is
 * set appropriately.
 */
int nta_agent_add_tport(nta_agent_t *self,
			url_string_t const *uri,
			tag_type_t tag, tag_value_t value, ...)
{
  url_t *url;
  char tp[32];
  char maddr[256];
  char comp[32];
  tp_name_t tpn[1] = {{ NULL }};
  char const * const * tports = tports_sip;
  int error;
  ta_list ta;

  if (self == NULL) {
    su_seterrno(EINVAL);
    return -1;
  }

  if (uri == NULL)
    uri = (url_string_t *)"sip:*";
  else if (url_string_p(uri) ?
	   strcmp(uri->us_str, "*") == 0 :
	   uri->us_url->url_type == url_any) {
    uri = (url_string_t *)"sip:*:*";
  }

  if (!(url = url_hdup(self->sa_home, uri->us_url)) ||
      (url->url_type != url_sip && url->url_type != url_sips)) {
    if (url_string_p(uri))
      SU_DEBUG_1(("nta: %s: invalid bind URL\n", uri->us_str));
    else
      SU_DEBUG_1(("nta: invalid bind URL\n"));
    su_seterrno(EINVAL);
    return -1;
  }

  if (url->url_type == url_sip) {
    tpn->tpn_proto = "*";
    tports = tports_sip;
  }
  else {
    assert(url->url_type == url_sips);
    tpn->tpn_proto = "tls";
    tports = tports_sips;
  }

  tpn->tpn_canon = url->url_host;
  tpn->tpn_host = url->url_host;
  tpn->tpn_port = url_port(url);

  if (url->url_params) {
    if (url_param(url->url_params, "transport", tp, sizeof(tp)) > 0) {
      if (strchr(tp, ',')) {
	int i; char *t, *tps[9];

	/* Split tp into transports */
	for (i = 0, t = tp; t && i < 8; i++) {
	  tps[i] = t;
	  if ((t = strchr(t, ',')))
	    *t++ = '\0';
	}

	tps[i] = NULL;
	tports = (char const * const *)tps;
      } else {
	tpn->tpn_proto = tp;
      }
    }
    if (url_param(url->url_params, "maddr", maddr, sizeof(maddr)) > 0)
      tpn->tpn_host = maddr;
    if (url_param(url->url_params, "comp", comp, sizeof(comp)) > 0)
      tpn->tpn_comp = comp;
#if !HAVE_SIGCOMP
    if (str0casecmp(tpn->tpn_comp, "sigcomp") == 0) {
      SU_DEBUG_1(("nta(%p): sigcomp not supported for UA " 
		  URL_PRINT_FORMAT "\n",
		  self, URL_PRINT_ARGS(url)));
    }
#endif
  }

  ta_start(ta, tag, value);

  if (self->sa_tports == NULL) {
    /* Create master transport */
#if HAVE_SIGCOMP
    struct sigcomp_algorithm const *algorithm = self->sa_algorithm;

    if (algorithm == NULL)
      algorithm = sigcomp_algorithm_by_name(getenv("SIGCOMP_ALGORITHM"));

    self->sa_state_handler = sigcomp_state_handler_create();

    if (self->sa_state_handler)
      self->sa_compartment = 
	sigcomp_compartment_create(algorithm, self->sa_state_handler, 0,
				   "", 0, NULL, 0);

    if (self->sa_compartment) {
      agent_sigcomp_options(self, self->sa_compartment);
      sigcomp_compartment_option(self->sa_compartment, "stateless");
    }
    else
      SU_DEBUG_1(("nta: initializing SigComp: %s\n", strerror(errno)));
#endif

    if (!(self->sa_tports = 
	  tport_tcreate(self, nta_agent_class, self->sa_root,
			TPTAG_SDWN_ERROR(0),
			TPTAG_IDLE(1800000),
			TPTAG_DEBUG_DROP(self->sa_drop_prob),
			IF_SIGCOMP_TPTAG_COMPARTMENT(self->sa_compartment)
			ta_tags(ta)))) {
      error = su_errno();
      SU_DEBUG_9(("nta: cannot create master transport: %s\n",
		  su_strerror(error)));
      goto error;
    }
    else
      SU_DEBUG_9(("nta: master transport created\n"));
  }

  if (tport_tbind(self->sa_tports, tpn, tports, ta_tags(ta)) < 0) {
    error = su_errno();
    SU_DEBUG_1(("nta: bind(%s:%s;transport=%s%s%s%s%s): %s\n",
		tpn->tpn_canon, tpn->tpn_port, tpn->tpn_proto,
		tpn->tpn_canon != tpn->tpn_host ? ";maddr=" : "",
		tpn->tpn_canon != tpn->tpn_host ? tpn->tpn_host : "",
		tpn->tpn_comp ? ";comp=" : "",
		tpn->tpn_comp ? tpn->tpn_comp : "",
		su_strerror(error)));
    goto error;
  }
  else
    SU_DEBUG_5(("nta: bound to (%s:%s;transport=%s%s%s%s%s)\n",
		tpn->tpn_canon, tpn->tpn_port, tpn->tpn_proto,
		tpn->tpn_canon != tpn->tpn_host ? ";maddr=" : "",
		tpn->tpn_canon != tpn->tpn_host ? tpn->tpn_host : "",
		tpn->tpn_comp ? ";comp=" : "",
		tpn->tpn_comp ? tpn->tpn_comp : ""));

  /* XXX - when to use maddr? */
  if ((agent_init_via(self, 0)) < 0) {
    error = su_errno();
    SU_DEBUG_1(("nta: cannot create Via headers\n"));
    goto error;
  }
  else
    SU_DEBUG_9(("nta: Via fields initialized\n"));

  if ((agent_init_contact(self)) < 0) {
    error = su_errno();
    SU_DEBUG_1(("nta: cannot create Contact header\n"));
    goto error;
  }
  else
    SU_DEBUG_9(("nta: Contact header created\n"));

  su_free(self->sa_home, url);
  ta_end(ta);

  return 0;

 error:
  ta_end(ta);
  su_seterrno(error);
  return -1;
}


/** Initialize Via headers. */
static
int agent_init_via(nta_agent_t *self, int use_maddr)
{
  sip_via_t *v, **vv;
  tport_t *tp;

  for (vv = &self->sa_vias; *vv; vv = &(*vv)->v_next)
    ;

  self->sa_tport_ip4 = 0;
  self->sa_tport_ip6 = 0;
  self->sa_tport_udp = 0;
  self->sa_tport_tcp = 0;
  self->sa_tport_sctp = 0;
  self->sa_tport_tls = 0;

  /* Set via fields for the tports */
  for (tp = tport_primaries(self->sa_tports); tp; tp = tport_next(tp)) {
    int maddr;
    tp_name_t tpn[1];
    char const *comp = NULL;

    *tpn = *tport_name(tp);

    assert(tpn->tpn_proto);
    assert(tpn->tpn_canon);
    assert(tpn->tpn_host);
    assert(tpn->tpn_port);

#if 0
    if (getenv("SIP_UDP_CONNECT")
	&& strcmp(tpn->tpn_proto, "udp") == 0)
      tport_set_params(tp, TPTAG_CONNECT(1), TAG_END());
#endif

    if (tport_has_ip4(tp)) self->sa_tport_ip4 = 1;

#if SU_HAVE_IN6
    if (tport_has_ip6(tp)) self->sa_tport_ip6 = 1;
#endif

    if (strcasecmp(tpn->tpn_proto, "udp") == 0)
      self->sa_tport_udp = 1;
    else if (strcasecmp(tpn->tpn_proto, "tcp") == 0)
      self->sa_tport_tcp = 1;
    else if (strcasecmp(tpn->tpn_proto, "sctp") == 0)
      self->sa_tport_sctp = 1;

    if (tport_has_tls(tp)) self->sa_tport_tls = 1;

    if (tport_magic(tp))
      continue;

    if (strcmp(tpn->tpn_port, SIP_DEFAULT_SERV) == 0)
      tpn->tpn_port = NULL;

    maddr = use_maddr && strcasecmp(tpn->tpn_canon, tpn->tpn_host) != 0;

    comp = tpn->tpn_comp;

    v = sip_via_format(self->sa_home,
		       "%s/%s %s%s%s%s%s%s%s",
		       SIP_VERSION_CURRENT, tpn->tpn_proto,
		       tpn->tpn_canon,
		       tpn->tpn_port ? ":" : "",
		       tpn->tpn_port ? tpn->tpn_port : "",
		       maddr ? ";maddr=" : "", maddr ? tpn->tpn_host : "",
		       comp ? ";comp=" : "", comp ? comp : "");

    if (v == NULL)
      return -1;

    tport_set_magic(tp, v);

    /** Add a duplicate to the list shown to application */
    *vv = sip_via_dup(self->sa_home, v);
    if (*vv == NULL)
      return -1;
    vv = &(*vv)->v_next;
  }

  if (self->sa_tport_udp)
    agent_set_udp_params(self, self->sa_udp_mtu);

  return 0;
}


/** Initialize main contact header. */
static
int agent_init_contact(nta_agent_t *self)
{
  sip_via_t const *v1 = self->sa_vias, *v2;
  char const *tp;

  if (self->sa_contact)
    return 0;

  if (!v1) return -1;
  tp = strrchr(v1->v_protocol, '/');
  if (!tp++)
    return -1;

  v2 = v1->v_next;

  if (v2 && 
      strcasecmp(v1->v_host, v2->v_host) == 0 &&
      strcasecmp(v1->v_port, v2->v_port) == 0) {
    char const *p1 = v1->v_protocol, *p2 = v2->v_protocol;

    if (strcasecmp(p1, sip_transport_udp))
      p1 = v2->v_protocol, p2 = v1->v_protocol;

    if (strcasecmp(p1, sip_transport_udp) == 0 &&
	strcasecmp(p2, sip_transport_tcp) == 0)
      /* Do not include transport if we have both UDP and TCP */
      tp = NULL;
  }

  self->sa_contact = 
    sip_contact_create_from_via_with_transport(self->sa_home, v1, NULL, tp);

  if (!self->sa_contact)
    return -1;

  return 0;
}

/** Return Via line corresponging to tport. */
static
sip_via_t const *agent_tport_via(tport_t *tport)
{
  return tport_magic(tport);
}

/** Insert Via to a request message */
static
int outgoing_insert_via(nta_outgoing_t *orq, 
			sip_via_t const *via)
{
  nta_agent_t *self = orq->orq_agent;
  msg_t *msg = orq->orq_request;
  sip_t *sip = sip_object(msg);
  char const *branch = orq->orq_via_branch;
  int user_via = orq->orq_user_via;
  sip_via_t *v;
  int clear = 0;

  assert(sip); assert(via);

  if (user_via && sip->sip_via) {
    /* Use existing Via provided by application */
    v = sip->sip_via;
  }
  else if (msg && via && sip->sip_request &&
	   (v = sip_via_copy(msg_home(msg), via))) {
    msg_header_insert(msg, (msg_pub_t *)sip, (msg_header_t *)v);
  }
  else
    return -1;

  if (orq->orq_method != sip_method_ack) {
    if (!v->v_rport && 
	((self->sa_rport && v->v_protocol == sip_transport_udp) ||
	 (self->sa_tcp_rport && v->v_protocol == sip_transport_tcp)))
      msg_header_add_param(msg_home(msg), v->v_common, "rport");
  }
  else {
    /* msg_header_remove_param(v->v_common, "comp"); */
  }

  if (!orq->orq_tpn->tpn_comp)
    msg_header_remove_param(v->v_common, "comp");

  if (branch && branch != v->v_branch)
    msg_header_add_param(msg_home(msg), v->v_common, branch);

  if (via->v_protocol != v->v_protocol &&
      strcasecmp(via->v_protocol, v->v_protocol))
    clear = 1, v->v_protocol = via->v_protocol;

  /* XXX - should we do this? */
  if (via->v_host != v->v_host &&
      str0cmp(via->v_host, v->v_host))
    clear = 1, v->v_host = via->v_host;

  if (via->v_port != v->v_port &&
      str0cmp(via->v_port, v->v_port))
    clear = 1, v->v_port = via->v_port;

  if (clear)
    msg_fragment_clear(v->v_common);

  return 0;
}

/** Get destination name from Via. 
 *
 * If @a using_rport is non-null, try rport.
 * If *using_rport is non-zero, try rport even if <protocol> is not UDP.
 * If <protocol> is UDP, set *using_rport to zero.
 */
static
int nta_tpn_by_via(tp_name_t *tpn, sip_via_t const *v, int *using_rport)
{
  if (!v)
    return -1;

  tpn->tpn_proto = sip_via_transport(v);
  tpn->tpn_canon = v->v_host;

  if (v->v_maddr)
    tpn->tpn_host = v->v_maddr;
  else if (v->v_received)
    tpn->tpn_host = v->v_received;
  else
    tpn->tpn_host = v->v_host;

  tpn->tpn_port = sip_via_port(v, using_rport);
  tpn->tpn_comp = v->v_comp;
  tpn->tpn_ident = NULL;

  return 0;
}

/** Get transport name from URL. */
int nta_tpn_by_url(su_home_t *home,