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Commit 62932069 authored by Kai Vehmanen's avatar Kai Vehmanen
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Added initial DNS-SRV lookup support to stun. 

darcs-hash:20060322195701-7659e-941bf1d0e955951b61b57de3020d0f6c981fadfb.gz
parent 9259f476
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Showing with 227 additions and 98 deletions
libsofia-sip-ua/nth/Makefile.am
View file @ 62932069
......@@ -42,6 +42,7 @@ LDADD = libnth.la \
../sresolv/libsresolv.la \
../tport/libtport.la \
../stun/libstun.la \
../sresolv/libsresolv.la \
../url/liburl.la \
../msg/libmsg.la \
../bnf/libbnf.la \
......
libsofia-sip-ua/stun/Makefile.am
View file @ 62932069
......@@ -36,6 +36,7 @@ BUILT_SOURCES = stun_tag_ref.c
COVERAGE_INPUT = $(libstun_la_SOURCES) $(include_sofia_HEADERS)
LDADD = libstun.la \
../sresolv/libsresolv.la \
../su/libsu.la
torture_stun_LDFLAGS = -static
......
libsofia-sip-ua/stun/sofia-sip/stun.h
View file @ 62932069
......@@ -66,14 +66,15 @@ extern char const stun_version[]; /**< Name and version of STUN software */
/**
* STUN Action types. These define the current discovery process.
* Defined as a bitmap.
*/
typedef enum stun_action_s {
stun_action_no_action,
stun_action_tls_query,
stun_action_binding_request,
stun_action_keepalive,
stun_action_get_nattype,
stun_action_get_lifetime,
stun_action_no_action = 1,
stun_action_tls_query = 2,
stun_action_binding_request = 4,
stun_action_keepalive = 8,
stun_action_get_nattype = 16,
stun_action_get_lifetime = 32,
} stun_action_t;
/**
......@@ -84,6 +85,9 @@ typedef enum stun_state_e {
stun_no_assigned_event,
stun_dispose_me,
/* DNS-SRV lookups */
stun_dns_lookup_pending,
/* TLS events */
stun_tls_connecting,
stun_tls_ssl_connecting,
......@@ -170,14 +174,13 @@ su_root_t *stun_root(stun_handle_t *sh);
int stun_is_requested(tag_type_t tag, tag_value_t value, ...);
/* -------------------------------------------------------------------
* Functions for 'Binding Discovery' usage (RFC3489bis) */
* Functions for 'Binding Discovery' usage (RFC3489/3489bis) */
int stun_request_shared_secret(stun_handle_t *sh);
/** Bind a socket using STUN. */
int stun_bind(stun_handle_t *sh,
stun_discovery_f,
stun_discovery_magic_t *magic,
/* su_localinfo_t *my_addr, */
tag_type_t tag, tag_value_t value,
...);
......@@ -201,7 +204,6 @@ int stun_lifetime(stun_discovery_t *sd);
/* -------------------------------------------------------------------
* Functions for 'Connectivity Check' and 'NAT Keepalives' usages (RFC3489bis) */
/* other functions */
int stun_set_uname_pwd(stun_handle_t *sh,
const char *uname,
int len_uname,
......@@ -211,7 +213,8 @@ int stun_set_uname_pwd(stun_handle_t *sh,
int stun_msg_is_keepalive(uint16_t data);
int stun_message_length(void *data, int len, int end_of_message);
/** Process incoming message */
/* Process incoming message */
int stun_process_message(stun_handle_t *sh, su_socket_t s,
su_sockaddr_t *sa, socklen_t salen,
void *data, int len);
......@@ -236,9 +239,9 @@ su_socket_t stun_discovery_get_socket(stun_discovery_t *sd);
/*********************************************************/
/* Deprecated functions. These are supported with limited
compatibility. */
/* --------------------------------------------------------------------
* Deprecated functions. These are supported with limited
* compatibility. */
su_root_t *stun_handle_root(stun_handle_t *sh);
int stun_handle_request_shared_secret(stun_handle_t *sh);
......
libsofia-sip-ua/stun/stun.c
View file @ 62932069
......@@ -25,7 +25,7 @@
/**
* @file stun.c STUN client module
*
* See RFC 3489 for further information.
* See RFC 3489/3489bis for further information.
*
* @author Martti Mela <Martti.Mela@nokia.com>
* @author Tat Chan <Tat.Chan@nokia.com>
......@@ -40,7 +40,6 @@
#include <assert.h>
#define SU_ROOT_MAGIC_T struct stun_magic_t
/* #define SU_WAKEUP_ARG_T struct stun_handle_s */
#include "sofia-sip/stun.h"
#include "stun_internal.h"
......@@ -74,12 +73,14 @@ enum {
};
int stun_change_map[4][4] = {
#if 0 /* XXX: not used at the moment (2006/03) */
static int stun_change_map[4][4] = {
{0, 1, 2, 3}, /* no change */
{2, 3, 0, 1}, /* change ip */
{1, 0, 3, 2}, /* change port */
{3, 2, 1, 0} /* change ip and port, Ca:Cp */
};
#endif
/* NAT TYPES */
......@@ -129,16 +130,17 @@ struct stun_discovery_s {
su_socket_t sd_socket2; /**< Alternative socket */
int sd_index; /**< root_register index */
/* Binding discovery */
su_sockaddr_t sd_addr_seen_outside[1]; /**< local address */
/* NAT type related */
stun_nattype_t sd_nattype; /**< Determined NAT type */
int sd_first; /**< These are the requests */
int sd_second;
int sd_third;
int sd_fourth;
unsigned sd_first:1; /**< These are the requests */
unsigned sd_second:1;
unsigned sd_third:1;
unsigned sd_fourth:1;
unsigned :0;
/* Life time related */
int sd_lt_cur;
......@@ -189,6 +191,13 @@ struct stun_handle_s
su_localinfo_t sh_localinfo; /**< local addrinfo */
su_sockaddr_t sh_local_addr[1]; /**< local address */
char *sh_domain; /**< domain address for DNS-SRV lookups */
stun_request_t *sh_dns_pend_req;
stun_discovery_t *sh_dns_pend_sd;
stun_action_t sh_dns_pend_action;
stun_dns_lookup_t *sh_dns_lookup;
#if defined(HAVE_OPENSSL)
SSL_CTX *sh_ctx; /**< SSL context for TLS */
SSL *sh_ssl; /**< SSL handle for TLS */
......@@ -281,37 +290,42 @@ char const stun_version[] =
"sofia-sip-stun";
#endif
int do_action(stun_handle_t *sh, stun_msg_t *binding_response);
int stun_tls_callback(su_root_magic_t *m, su_wait_t *w, su_wakeup_arg_t *arg);
int process_binding_request(stun_request_t *req, stun_msg_t *binding_response);
stun_discovery_t *stun_discovery_create(stun_handle_t *sh,
stun_action_t action,
stun_discovery_f sdf,
stun_discovery_magic_t *magic);
int stun_discovery_destroy(stun_discovery_t *sd);
int action_bind(stun_request_t *req, stun_msg_t *binding_response);
int action_determine_nattype(stun_request_t *req, stun_msg_t *binding_response);
int process_get_lifetime(stun_request_t *req, stun_msg_t *binding_response);
stun_request_t *stun_request_create(stun_discovery_t *sd);
int stun_send_binding_request(stun_request_t *req,
static int do_action(stun_handle_t *sh, stun_msg_t *binding_response);
static int stun_tls_callback(su_root_magic_t *m, su_wait_t *w, su_wakeup_arg_t *arg);
static int process_binding_request(stun_request_t *req, stun_msg_t *binding_response);
static stun_discovery_t *stun_discovery_create(stun_handle_t *sh,
stun_action_t action,
stun_discovery_f sdf,
stun_discovery_magic_t *magic);
static int stun_discovery_destroy(stun_discovery_t *sd);
static int action_bind(stun_request_t *req, stun_msg_t *binding_response);
static int action_determine_nattype(stun_request_t *req, stun_msg_t *binding_response);
static int process_get_lifetime(stun_request_t *req, stun_msg_t *binding_response);
static stun_request_t *stun_request_create(stun_discovery_t *sd);
static int stun_send_binding_request(stun_request_t *req,
su_sockaddr_t *srvr_addr);
int stun_bind_callback(stun_magic_t *m, su_wait_t *w, su_wakeup_arg_t *arg);
static int stun_bind_callback(stun_magic_t *m, su_wait_t *w, su_wakeup_arg_t *arg);
/* timers */
void stun_sendto_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg);
void stun_tls_connect_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg);
void stun_get_lifetime_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg);
void stun_keepalive_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg);
static void stun_sendto_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg);
static void stun_tls_connect_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg);
static void stun_get_lifetime_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg);
static void stun_keepalive_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg);
static int priv_stun_bind_send(stun_handle_t *sh, stun_request_t *req, stun_discovery_t *sd);
static void priv_dns_queue_bind(stun_handle_t *sh, stun_request_t *req, stun_discovery_t *sd);
static void priv_dns_queue_shared_secret(stun_handle_t *sh);
static int priv_stun_bind_send(stun_handle_t *sh, stun_request_t *req, stun_discovery_t *sd);
/* Deprecated. Use stun_root(). */
su_root_t *stun_handle_root(stun_handle_t *self)
......@@ -358,7 +372,7 @@ int stun_is_requested(tag_type_t tag, tag_value_t value, ...)
if (t && t->t_value)
stun_server = (char *)t->t_value;
else if (t2 && t2->t_value)
stun_server = (char *)t->t_value;
stun_server = (char *)t2->t_value;
else
stun_server = getenv("STUN_SERVER");
ta_end(ta);
......@@ -415,7 +429,8 @@ stun_handle_t *stun_handle_create(stun_magic_t *context,
SU_DEBUG_5(("%s(\"%s\"): called\n",
"stun_handle_tcreate", server));
if (!server)
/* fail, if no server or a domain for a DNS-SRV lookup is specified */
if (!server && !domain)
return NULL;
stun->sh_pri_info.ai_addrlen = 16;
......@@ -427,10 +442,15 @@ stun_handle_t *stun_handle_create(stun_magic_t *context,
stun->sh_localinfo.li_addrlen = 16;
stun->sh_localinfo.li_addr = stun->sh_local_addr;
err = stun_atoaddr(AF_INET, &stun->sh_pri_info, server);
stun->sh_domain = su_strdup(stun->sh_home, domain);
stun->sh_dns_lookup = NULL;
if (server) {
err = stun_atoaddr(AF_INET, &stun->sh_pri_info, server);
if (err < 0)
return NULL;
if (err < 0)
return NULL;
}
stun->sh_nattype = stun_nat_unknown;
......@@ -438,7 +458,7 @@ stun_handle_t *stun_handle_create(stun_magic_t *context,
stun->sh_context = context;
stun->sh_callback = cb;
/* always try TLS: */
stun->sh_use_msgint = 1;
stun->sh_use_msgint = 1; /* XXX: do not commit */
/* whether use of shared-secret msgint is required */
stun->sh_req_msgint = req_msg_integrity;
......@@ -489,6 +509,13 @@ int stun_request_shared_secret(stun_handle_t *sh)
enter;
if (!sh->sh_pri_addr[0].su_port) {
/* no STUN server address, perform a DNS-SRV lookup */
SU_DEBUG_5(("Delaying STUN shared-secret req. for DNS-SRV query.\n"));
priv_dns_queue_shared_secret(sh);
return 0;
}
ai = &sh->sh_pri_info;
if (sh->sh_use_msgint == 1) {
......@@ -570,8 +597,7 @@ int stun_request_shared_secret(stun_handle_t *sh)
}
#endif /* HAVE_OPENSSL */
stun_request_t *stun_request_create(stun_discovery_t *sd)
static stun_request_t *stun_request_create(stun_discovery_t *sd)
{
stun_handle_t *sh = sd->sd_handle;
stun_request_t *req = NULL;
......@@ -648,6 +674,8 @@ void stun_handle_destroy(stun_handle_t *sh)
enter;
stun_dns_lookup_destroy(sh->sh_dns_lookup);
/* There can be several discoveries using the same socket. It is
still enough to deregister the socket in first of them */
for (sd = sh->sh_discoveries; sd; ) {
......@@ -840,6 +868,86 @@ int stun_handle_bind(stun_handle_t *sh,
return err;
}
static void priv_lookup_cb(stun_dns_lookup_t *self,
stun_magic_t *magic)
{
const char *udp_target = NULL;
uint16_t udp_port = 0;
int res;
stun_handle_t *sh = (stun_handle_t *)magic;
res = stun_dns_lookup_get_results(self,
NULL, NULL,
&udp_target, &udp_port);
if (res == 0) {
/* XXX: assumption that same host and port used for UDP/TLS */
if (udp_target) {
stun_atoaddr(AF_INET, &sh->sh_pri_info, udp_target);
if (udp_port)
sh->sh_pri_addr[0].su_port = htons(udp_port);
else
sh->sh_pri_addr[0].su_port = htons(STUN_DEFAULT_PORT);
/* step: now that server address is known, continue
* the pending action */
SU_DEBUG_5(("STUN server address found, running queue actions (%d).\n",
sh->sh_dns_pend_action));
if (sh->sh_dns_pend_action & stun_action_tls_query)
stun_request_shared_secret(sh);
if (sh->sh_dns_pend_action & stun_action_binding_request)
priv_stun_bind_send(sh, sh->sh_dns_pend_req, sh->sh_dns_pend_sd);
sh->sh_dns_pend_action = 0;
}
}
}
/**
* Queus an stun bind action for later execution once
* DNS-SRV lookup is succesfully completed.
*/
static void priv_dns_queue_bind(stun_handle_t *sh, stun_request_t *req, stun_discovery_t *sd)
{
if (!sh->sh_dns_lookup) {
sh->sh_dns_lookup = stun_dns_lookup((stun_magic_t*)sh, sh->sh_root, priv_lookup_cb, sh->sh_domain);
}
sh->sh_dns_pend_req = req;
sh->sh_dns_pend_sd = sd;
sh->sh_dns_pend_action |= stun_action_binding_request;
}
/**
* Queus an stun shared-secret action for later execution
* once DNS-SRV lookup is succesfully completed.
*/
static void priv_dns_queue_shared_secret(stun_handle_t *sh)
{
if (!sh->sh_dns_lookup) {
sh->sh_dns_lookup = stun_dns_lookup((stun_magic_t*)sh, sh->sh_root, priv_lookup_cb, sh->sh_domain);
}
sh->sh_dns_pend_action |= stun_action_tls_query;
}
static int priv_stun_bind_send(stun_handle_t *sh, stun_request_t *req, stun_discovery_t *sd)
{
int res = stun_send_binding_request(req, sh->sh_pri_addr);
if (res < 0) {
stun_free_message(req->sr_msg);
stun_discovery_destroy(sd);
}
return -1;
}
/** Bind a socket using STUN client.
*
* The function stun_bind() obtains a global address for a UDP socket using
......@@ -883,7 +991,7 @@ int stun_bind(stun_handle_t *sh,
ta_list ta;
stun_action_t action = stun_action_binding_request;
int index, s_reg = 0;
enter;
if (sh == NULL)
......@@ -904,17 +1012,21 @@ int stun_bind(stun_handle_t *sh,
req = stun_request_create(sd);
if (stun_make_binding_req(sh, req, req->sr_msg, 0, 0) < 0 ||
stun_send_binding_request(req, sh->sh_pri_addr) < 0) {
if (stun_make_binding_req(sh, req, req->sr_msg, 0, 0) < 0) {
stun_discovery_destroy(sd);
stun_free_message(req->sr_msg);
return -1;
}
/* note: we always report success if bind() succeeds */
return 0;
if (!sh->sh_pri_addr[0].su_port) {
/* no STUN server address, perform a DNS-SRV lookup */
SU_DEBUG_5(("Delaying STUN bind for DNS-SRV query.\n"));
priv_dns_queue_bind(sh, req, sd);
return 0;
}
/* note: we always report success if bind() succeeds */
return priv_stun_bind_send(sh, req, sd);
}
......@@ -935,10 +1047,10 @@ su_sockaddr_t *stun_discovery_get_address(stun_discovery_t *sd)
return sd->sd_addr_seen_outside;
}
stun_discovery_t *stun_discovery_create(stun_handle_t *sh,
stun_action_t action,
stun_discovery_f sdf,
stun_discovery_magic_t *magic)
static stun_discovery_t *stun_discovery_create(stun_handle_t *sh,
stun_action_t action,
stun_discovery_f sdf,
stun_discovery_magic_t *magic)
{
stun_discovery_t *sd = NULL;
......@@ -967,7 +1079,7 @@ stun_discovery_t *stun_discovery_create(stun_handle_t *sh,
return sd;
}
int stun_discovery_destroy(stun_discovery_t *sd)
static int stun_discovery_destroy(stun_discovery_t *sd)
{
stun_handle_t *sh;
......@@ -985,7 +1097,6 @@ int stun_discovery_destroy(stun_discovery_t *sd)
else if (!sd->sd_next)
sh->sh_discoveries = NULL;
sd->sd_prev = NULL;
sd->sd_next = NULL;
free(sd);
......@@ -1011,11 +1122,14 @@ int stun_handle_get_nattype(stun_handle_t *sh,
* Initiates STUN discovery proces to find out NAT
* characteristics.
*
* Note: does not support STUNTAG_DOMAIN().
*
* @TAGS
* @TAG STUNTAG_SOCKET Bind socket for STUN
* @TAG STUNTAG_REGISTER_SOCKET Register socket for eventloop owned by STUN
* @TAG STUNTAG_SERVER() stun server hostname or dotted IPv4 address
*
* @return 0 on success, non-zero on error
*/
int stun_get_nattype(stun_handle_t *sh,
stun_discovery_f sdf,
......@@ -1114,7 +1228,7 @@ int stun_get_nattype(stun_handle_t *sh,
*******************************************************************/
#if defined(HAVE_OPENSSL)
int stun_tls_callback(su_root_magic_t *m, su_wait_t *w, su_wakeup_arg_t *arg)
static int stun_tls_callback(su_root_magic_t *m, su_wait_t *w, su_wakeup_arg_t *arg)
{
stun_discovery_t *sd = arg;
stun_handle_t *self = sd->sd_handle;
......@@ -1362,7 +1476,7 @@ int stun_tls_callback(su_root_magic_t *m, su_wait_t *w, su_wakeup_arg_t *arg)
return 0;
}
#else
int stun_tls_callback(su_root_magic_t *m, su_wait_t *w, su_wakeup_arg_t *arg)
static int stun_tls_callback(su_root_magic_t *m, su_wait_t *w, su_wakeup_arg_t *arg)
{
return 0;
}
......@@ -1370,9 +1484,9 @@ int stun_tls_callback(su_root_magic_t *m, su_wait_t *w, su_wakeup_arg_t *arg)
#if defined(HAVE_OPENSSL)
void stun_tls_connect_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg)
static void stun_tls_connect_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg)
{
stun_discovery_t *sd = arg;
stun_handle_t *sh = sd->sd_handle;
......@@ -1396,9 +1510,9 @@ void stun_tls_connect_timer_cb(su_root_magic_t *magic,
return;
}
#else
void stun_tls_connect_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg)
static void stun_tls_connect_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg)
{
}
#endif /* HAVE_OPENSSL */
......@@ -1479,7 +1593,7 @@ stun_request_t *find_request(stun_handle_t *self, uint16_t *id)
}
/** Process socket event */
int stun_bind_callback(stun_magic_t *m, su_wait_t *w, su_wakeup_arg_t *arg)
static int stun_bind_callback(stun_magic_t *m, su_wait_t *w, su_wakeup_arg_t *arg)
{
stun_discovery_t *sd = arg;
stun_handle_t *self = sd->sd_handle;
......@@ -1509,8 +1623,6 @@ int stun_bind_callback(stun_magic_t *m, su_wait_t *w, su_wakeup_arg_t *arg)
return 0;
}
/* s = self->sh_bind_socket; */
/* receive response */
recv_len = sizeof(recv);
dgram_len = recvfrom(s, dgram, sizeof(dgram), 0, (struct sockaddr *) &recv,
......@@ -1557,7 +1669,7 @@ int stun_bind_callback(stun_magic_t *m, su_wait_t *w, su_wakeup_arg_t *arg)
}
/** Choose the right state machine */
int do_action(stun_handle_t *sh, stun_msg_t *msg)
static int do_action(stun_handle_t *sh, stun_msg_t *msg)
{
stun_request_t *req = NULL;
stun_action_t action = stun_action_no_action;
......@@ -1614,8 +1726,7 @@ int do_action(stun_handle_t *sh, stun_msg_t *msg)
return 0;
}
int process_binding_request(stun_request_t *req, stun_msg_t *binding_response)
static int process_binding_request(stun_request_t *req, stun_msg_t *binding_response)
{
int retval = -1, clnt_addr_len;
stun_attr_t *mapped_addr, *chg_addr;
......@@ -1671,9 +1782,9 @@ int process_binding_request(stun_request_t *req, stun_msg_t *binding_response)
}
void stun_get_lifetime_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg)
static void stun_get_lifetime_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg)
{
stun_request_t *req = arg;
stun_discovery_t *sd = req->sr_discovery;
......@@ -1697,7 +1808,7 @@ void stun_get_lifetime_timer_cb(su_root_magic_t *magic,
}
int process_get_lifetime(stun_request_t *req, stun_msg_t *binding_response)
static int process_get_lifetime(stun_request_t *req, stun_msg_t *binding_response)
{
stun_discovery_t *sd = req->sr_discovery;
stun_request_t *new;
......@@ -1802,7 +1913,7 @@ int process_get_lifetime(stun_request_t *req, stun_msg_t *binding_response)
}
int action_bind(stun_request_t *req, stun_msg_t *binding_response)
static int action_bind(stun_request_t *req, stun_msg_t *binding_response)
{
su_localinfo_t *li = NULL;
su_sockaddr_t *sa = NULL;
......@@ -1832,7 +1943,7 @@ int action_bind(stun_request_t *req, stun_msg_t *binding_response)
return 0;
}
int action_determine_nattype(stun_request_t *req, stun_msg_t *binding_response)
static int action_determine_nattype(stun_request_t *req, stun_msg_t *binding_response)
{
su_sockaddr_t local;
socklen_t locallen;
......@@ -2014,9 +2125,9 @@ int action_determine_nattype(stun_request_t *req, stun_msg_t *binding_response)
}
void stun_sendto_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg)
static void stun_sendto_timer_cb(su_root_magic_t *magic,
su_timer_t *t,
su_timer_arg_t *arg)
{
stun_request_t *req = arg;
stun_handle_t *sh = req->sr_handle;
......@@ -2136,8 +2247,8 @@ void stun_sendto_timer_cb(su_root_magic_t *magic,
* @ERROR ETIMEDOUT Request timed out.
*
*/
int stun_send_binding_request(stun_request_t *req,
su_sockaddr_t *srvr_addr)
static int stun_send_binding_request(stun_request_t *req,
su_sockaddr_t *srvr_addr)
{
su_timer_t *sendto_timer = NULL;
int s;
......@@ -2430,11 +2541,14 @@ int stun_handle_get_lifetime(stun_handle_t *sh,
* Initiates STUN discovery proces to find out NAT
* binding life-time settings.
*
* Note: does not support STUNTAG_DOMAIN().
*
* @TAGS
* @TAG STUNTAG_SOCKET Bind socket for STUN
* @TAG STUNTAG_REGISTER_SOCKET Register socket for eventloop owned by STUN
* @TAG STUNTAG_SERVER() stun server hostname or dotted IPv4 address
*
* @return 0 on success, non-zero on error
*/
int stun_get_lifetime(stun_handle_t *sh,