nta.c

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

	     NTATAG_PASS_408(agent->sa_pass_408),
	     NTATAG_PRELOAD(agent->sa_preload),
	     NTATAG_PROGRESS(agent->sa_progress),
	     NTATAG_REL100(agent->sa_invite_100rel),
	     NTATAG_SERVER_RPORT(agent->sa_server_rport),
	     NTATAG_SIGCOMP_ALGORITHM(agent->sa_algorithm),
	     NTATAG_SIGCOMP_OPTIONS(agent->sa_sigcomp_options ?
				    agent->sa_sigcomp_options :
				    "sip"),
	     NTATAG_SIPFLAGS(agent->sa_flags),
	     NTATAG_SIP_T1(agent->sa_t1),
	     NTATAG_SIP_T1X64(agent->sa_t1x64),
	     NTATAG_SIP_T2(agent->sa_t2),
	     NTATAG_SIP_T4(agent->sa_t4),
#if HAVE_SOFIA_SMIME
	     NTATAG_SMIME(agent->sa_smime),
#else
	     NTATAG_SMIME(NULL),
#endif
	     NTATAG_STATELESS(agent->sa_is_stateless),
	     NTATAG_TAG_3261(1),
	     NTATAG_TIMEOUT_408(agent->sa_timeout_408),
	     NTATAG_TIMER_C(agent->sa_timer_c),
	     NTATAG_UA(agent->sa_is_a_uas),
	     NTATAG_UDP_MTU(agent->sa_udp_mtu),
	     NTATAG_USER_VIA(agent->sa_user_via),
	     NTATAG_USE_NAPTR(agent->sa_use_naptr),
	     NTATAG_USE_SRV(agent->sa_use_srv),
	     NTATAG_USE_TIMESTAMP(agent->sa_timestamp),
	     TAG_END());
}

/**Get NTA statistics.
 *
 * The nta_agent_get_stats() function retrieves the stack statistics.
 *
 * @TAGS
 * NTATAG_S_ACKED_TR_REF(),
 * NTATAG_S_BAD_MESSAGE_REF(),
 * NTATAG_S_BAD_REQUEST_REF(),
 * NTATAG_S_BAD_RESPONSE_REF(),
 * NTATAG_S_CANCELED_TR_REF(),
 * NTATAG_S_CLIENT_TR_REF(),
 * NTATAG_S_DIALOG_TR_REF(),
 * NTATAG_S_DROP_REQUEST_REF(),
 * NTATAG_S_DROP_RESPONSE_REF(),
 * NTATAG_S_IRQ_HASH_REF(),
 * NTATAG_S_IRQ_HASH_USED_REF(),
 * NTATAG_S_LEG_HASH_REF(),
 * NTATAG_S_LEG_HASH_USED_REF(),
 * NTATAG_S_MERGED_REQUEST_REF(),
 * NTATAG_S_ORQ_HASH_REF(),
 * NTATAG_S_ORQ_HASH_USED_REF(),
 * NTATAG_S_RECV_MSG_REF(),
 * NTATAG_S_RECV_REQUEST_REF(),
 * NTATAG_S_RECV_RESPONSE_REF(),
 * NTATAG_S_RECV_RETRY_REF(),
 * NTATAG_S_RETRY_REQUEST_REF(),
 * NTATAG_S_RETRY_RESPONSE_REF(),
 * NTATAG_S_SENT_MSG_REF(),
 * NTATAG_S_SENT_REQUEST_REF(),
 * NTATAG_S_SENT_RESPONSE_REF(),
 * NTATAG_S_SERVER_TR_REF(),
 * NTATAG_S_TOUT_REQUEST_REF(), 
 * NTATAG_S_TOUT_RESPONSE_REF(),
 * NTATAG_S_TRLESS_200_REF(),
 * NTATAG_S_TRLESS_REQUEST_REF(),
 * NTATAG_S_TRLESS_RESPONSE_REF(), and
 * NTATAG_S_TRLESS_TO_TR_REF(),
 */
int nta_agent_get_stats(nta_agent_t *agent,
			tag_type_t tag, tag_value_t value, ...)
{
  int n;
  ta_list ta;

  if (!agent)
    return su_seterrno(EINVAL), -1;

  ta_start(ta, tag, value);

  n = tl_tgets(ta_args(ta),
	       NTATAG_S_IRQ_HASH(agent->sa_incoming->iht_size),
	       NTATAG_S_ORQ_HASH(agent->sa_outgoing->oht_size),
	       NTATAG_S_LEG_HASH(agent->sa_dialogs->lht_size),
	       NTATAG_S_IRQ_HASH_USED(agent->sa_incoming->iht_used),
	       NTATAG_S_ORQ_HASH_USED(agent->sa_outgoing->oht_used),
	       NTATAG_S_LEG_HASH_USED(agent->sa_dialogs->lht_used),
	       NTATAG_S_RECV_MSG(agent->sa_stats->as_recv_msg),
	       NTATAG_S_RECV_REQUEST(agent->sa_stats->as_recv_request),
	       NTATAG_S_RECV_RESPONSE(agent->sa_stats->as_recv_response),
	       NTATAG_S_BAD_MESSAGE(agent->sa_stats->as_bad_message),
	       NTATAG_S_BAD_REQUEST(agent->sa_stats->as_bad_request),
	       NTATAG_S_BAD_RESPONSE(agent->sa_stats->as_bad_response),
	       NTATAG_S_DROP_REQUEST(agent->sa_stats->as_drop_request),
	       NTATAG_S_DROP_RESPONSE(agent->sa_stats->as_drop_response),
	       NTATAG_S_CLIENT_TR(agent->sa_stats->as_client_tr),
	       NTATAG_S_SERVER_TR(agent->sa_stats->as_server_tr),
	       NTATAG_S_DIALOG_TR(agent->sa_stats->as_dialog_tr),
	       NTATAG_S_ACKED_TR(agent->sa_stats->as_acked_tr),
	       NTATAG_S_CANCELED_TR(agent->sa_stats->as_canceled_tr),
	       NTATAG_S_TRLESS_REQUEST(agent->sa_stats->as_trless_request),
	       NTATAG_S_TRLESS_TO_TR(agent->sa_stats->as_trless_to_tr),
	       NTATAG_S_TRLESS_RESPONSE(agent->sa_stats->as_trless_response),
	       NTATAG_S_TRLESS_200(agent->sa_stats->as_trless_200),
	       NTATAG_S_MERGED_REQUEST(agent->sa_stats->as_merged_request),
	       NTATAG_S_SENT_MSG(agent->sa_stats->as_sent_msg),
	       NTATAG_S_SENT_REQUEST(agent->sa_stats->as_sent_request),
	       NTATAG_S_SENT_RESPONSE(agent->sa_stats->as_sent_response),
	       NTATAG_S_RETRY_REQUEST(agent->sa_stats->as_retry_request),
	       NTATAG_S_RETRY_RESPONSE(agent->sa_stats->as_retry_response),
	       NTATAG_S_RECV_RETRY(agent->sa_stats->as_recv_retry),
	       NTATAG_S_TOUT_REQUEST(agent->sa_stats->as_tout_request),
	       NTATAG_S_TOUT_RESPONSE(agent->sa_stats->as_tout_response),
	       TAG_END());

  ta_end(ta);

  return n;
}

/**Calculate a new unique tag.
 *
 * This function generates a series of 2**64 unique tags for @From or @To
 * headers. The start of the tag series is derived from the NTP time the NTA
 * agent was initialized.
 *
 */
char const *nta_agent_newtag(su_home_t *home, char const *fmt, nta_agent_t *sa)
{
  char tag[(8 * 8 + 4)/ 5 + 1];

  if (sa == NULL)
    return su_seterrno(EINVAL), NULL;

  /* XXX - use a cryptographically safe func here? */
  sa->sa_tags += NTA_TAG_PRIME;

  msg_random_token(tag, sizeof(tag) - 1, &sa->sa_tags, sizeof(sa->sa_tags));

  if (fmt && fmt[0])
    return su_sprintf(home, fmt, tag);
  else
    return su_strdup(home, tag);
}

/**
 * Calculate branch value.
 */
static char const *stateful_branch(su_home_t *home, nta_agent_t *sa)
{
  char branch[(8 * 8 + 4)/ 5 + 1];

  /* XXX - use a cryptographically safe func here? */
  sa->sa_branch += NTA_BRANCH_PRIME;

  msg_random_token(branch, sizeof(branch) - 1, 
		   &sa->sa_branch, sizeof(sa->sa_branch));

  return su_sprintf(home, "branch=z9hG4bK%s", branch);
}

#include <sofia-sip/su_md5.h>

/**
 * Calculate branch value for stateless operation.
 * 
 * XXX - should include HMAC of previous @Via line.
 */
static
char const *stateless_branch(nta_agent_t *sa, 
			     msg_t *msg,
			     sip_t const *sip, 
			     tp_name_t const *tpn)
{
  su_md5_t md5[1];
  uint8_t digest[SU_MD5_DIGEST_SIZE];
  char branch[(SU_MD5_DIGEST_SIZE * 8 + 4)/ 5 + 1];
  sip_route_t const *r;

  assert(sip->sip_request);

  if (!sip->sip_via)
    return stateful_branch(msg_home(msg), sa);

  su_md5_init(md5);

  su_md5_str0update(md5, tpn->tpn_host);
  su_md5_str0update(md5, tpn->tpn_port);

  url_update(md5, sip->sip_request->rq_url);
  if (sip->sip_call_id) {
    su_md5_str0update(md5, sip->sip_call_id->i_id);
  }
  if (sip->sip_from) {
    url_update(md5, sip->sip_from->a_url);
    su_md5_stri0update(md5, sip->sip_from->a_tag);
  }
  if (sip->sip_to) {
    url_update(md5, sip->sip_to->a_url);
    /* XXX - some broken implementations include To tag in CANCEL */
    /* su_md5_str0update(md5, sip->sip_to->a_tag); */
  }
  if (sip->sip_cseq) {
    uint32_t cseq = htonl(sip->sip_cseq->cs_seq);
    su_md5_update(md5, &cseq, sizeof(cseq));
  }

  for (r = sip->sip_route; r; r = r->r_next)
    url_update(md5, r->r_url);

  su_md5_digest(md5, digest);

  msg_random_token(branch, sizeof(branch) - 1, digest, sizeof(digest));

  return su_sprintf(msg_home(msg), "branch=z9hG4bK.%s", branch);
}

/* ====================================================================== */
/* 2) Transport interface */

/* Local prototypes */
static int agent_create_master_transport(nta_agent_t *self, tagi_t *tags);
static int agent_init_via(nta_agent_t *self, tport_t *primaries, int use_maddr);
static int agent_init_contact(nta_agent_t *self);
static void agent_recv_message(nta_agent_t *agent,
			       tport_t *tport,
			       msg_t *msg,
			       sip_via_t *tport_via,
			       su_time_t now);
static void agent_tp_error(nta_agent_t *agent,
			   tport_t *tport,
			   int errcode,
			   char const *remote);
static void agent_update_tport(nta_agent_t *agent, tport_t *);

/**For each transport, we have name used by tport module, SRV prefixes used
 * for resolving, and NAPTR service/conversion.
 */
static 
struct sipdns_tport {
  char name[6];			/**< Named used by tport module */
  char port[6];			/**< Default port number */
  char prefix[14];		/**< Prefix for SRV domains */
  char service[10];		/**< NAPTR service */
}
#define SIPDNS_TRANSPORTS (4)
const sipdns_tports[SIPDNS_TRANSPORTS] = {
  { "udp",  "5060", "_sip._udp.",  "SIP+D2U"  },
  { "tcp",  "5060", "_sip._tcp.",  "SIP+D2T"  },
  { "sctp", "5060", "_sip._sctp.", "SIP+D2S" },
  { "tls",  "5061", "_sips._tcp.", "SIPS+D2T"  },
};

static char const * const tports_sip[] =
  {
    "udp", "tcp", "sctp", NULL
  };

static char const * const tports_sips[] =
  {
    "tls", NULL
  };

static tport_stack_class_t nta_agent_class[1] =
  {{
    sizeof(nta_agent_class),
    agent_recv_message,
    agent_tp_error,
    nta_msg_create_for_transport,
    agent_update_tport,
  }};


/** Add a transport to the agent.
 *
 * Creates a new transport and binds it
 * to the port specified by the @a uri. The @a uri must have sip: or sips:
 * scheme or be a wildcard uri ("*"). The @a uri syntax allowed is as
 * follows:
 *
 * @code url <scheme>:<host>[:<port>]<url-params> @endcode
 * where <url-params> may be
 * @code
 * ;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;
  }

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

  if (url->url_type == url_sip) {
    tpn->tpn_proto = "*";
    tports = tports_sip;
    if (!tpn->tpn_port || !tpn->tpn_port[0]) 
      tpn->tpn_port = SIP_DEFAULT_SERV;
  }
  else {
    assert(url->url_type == url_sips);
    tpn->tpn_proto = "*";
    tports = tports_sips;
    if (!tpn->tpn_port || !tpn->tpn_port[0]) 
      tpn->tpn_port = SIPS_DEFAULT_SERV;
  }

  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 (tpn->tpn_comp && 
	(nta_compressor_vtable == NULL || 
	 strcasecmp(tpn->tpn_comp, nta_compressor_vtable->ncv_name) != 0)) {
      SU_DEBUG_1(("nta(%p): comp=%s not supported for " URL_PRINT_FORMAT "\n",
		  (void *)self, tpn->tpn_comp, URL_PRINT_ARGS(url)));
    }
  }

  ta_start(ta, tag, value);

  if (self->sa_tports == NULL) {
    if (agent_create_master_transport(self, ta_args(ta)) < 0) {
      error = su_errno();
      SU_DEBUG_1(("nta: cannot create master transport: %s\n",
		  su_strerror(error)));
      goto error;
    }
  }

  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",