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/**
* @file turn.c TURN Module
*
* Copyright (C) 2010 Creytiv.com
*/
#include <re.h>
#include <baresip.h>
/**
* @defgroup turn turn
*
* Traversal Using Relays around NAT (TURN) for media NAT traversal
*
* XXX: use turn RSV_TOKEN for RTP/RTCP even/odd pair ?
*/
enum {LAYER = 0};
struct mnat_sess {
struct list medial;
struct sa srv;
struct stun_dns *dnsq;
char *user;
char *pass;
mnat_estab_h *estabh;
void *arg;
int mediac;
};
struct mnat_media {
struct le le;
struct sa addr1;
struct sa addr2;
struct mnat_sess *sess;
struct sdp_media *sdpm;
struct turnc *turnc1;
struct turnc *turnc2;
void *sock1;
void *sock2;
int proto;
};
static struct mnat *mnat;
static void session_destructor(void *arg)
{
struct mnat_sess *sess = arg;
list_flush(&sess->medial);
mem_deref(sess->dnsq);
mem_deref(sess->user);
mem_deref(sess->pass);
}
static void media_destructor(void *arg)
{
struct mnat_media *m = arg;
list_unlink(&m->le);
mem_deref(m->sdpm);
mem_deref(m->turnc1);
mem_deref(m->turnc2);
mem_deref(m->sock1);
mem_deref(m->sock2);
}
static void turn_handler1(int err, uint16_t scode, const char *reason,
const struct sa *relay_addr,
const struct sa *mapped_addr,
const struct stun_msg *msg,
void *arg)
{
struct mnat_media *m = arg;
(void)mapped_addr;
(void)msg;
if (!err && !scode) {
sdp_media_set_laddr(m->sdpm, relay_addr);
m->addr1 = *relay_addr;
if (m->turnc2 && !sa_isset(&m->addr2, SA_ALL))
return;
if (--m->sess->mediac)
return;
}
m->sess->estabh(err, scode, reason, m->sess->arg);
}
static void turn_handler2(int err, uint16_t scode, const char *reason,
const struct sa *relay_addr,
const struct sa *mapped_addr,
const struct stun_msg *msg,
void *arg)
{
struct mnat_media *m = arg;
(void)mapped_addr;
(void)msg;
if (!err && !scode) {
sdp_media_set_laddr_rtcp(m->sdpm, relay_addr);
m->addr2 = *relay_addr;
if (m->turnc1 && !sa_isset(&m->addr1, SA_ALL))
return;
if (--m->sess->mediac)
return;
}
m->sess->estabh(err, scode, reason, m->sess->arg);
}
static int media_start(struct mnat_sess *sess, struct mnat_media *m)
{
int err = 0;
if (m->sock1) {
err |= turnc_alloc(&m->turnc1, NULL,
m->proto, m->sock1, LAYER,
&sess->srv, sess->user, sess->pass,
TURN_DEFAULT_LIFETIME,
turn_handler1, m);
}
if (m->sock2) {
err |= turnc_alloc(&m->turnc2, NULL,
m->proto, m->sock2, LAYER,
&sess->srv, sess->user, sess->pass,
TURN_DEFAULT_LIFETIME,
turn_handler2, m);
}
return err;
}
static void dns_handler(int err, const struct sa *srv, void *arg)
{
struct mnat_sess *sess = arg;
struct le *le;
if (err)
goto out;
sess->srv = *srv;
for (le=sess->medial.head; le; le=le->next) {
struct mnat_media *m = le->data;
err = media_start(sess, m);
if (err)
goto out;
}
return;
out:
sess->estabh(err, 0, NULL, sess->arg);
}
static int session_alloc(struct mnat_sess **sessp, struct dnsc *dnsc,
int af, const char *srv, uint16_t port,
const char *user, const char *pass,
struct sdp_session *ss, bool offerer,
mnat_estab_h *estabh, void *arg)
{
struct mnat_sess *sess;
int err;
(void)ss;
(void)offerer;
if (!sessp || !dnsc || !srv || !user || !pass || !ss || !estabh)
return EINVAL;
sess = mem_zalloc(sizeof(*sess), session_destructor);
if (!sess)
return ENOMEM;
err = str_dup(&sess->user, user);
err |= str_dup(&sess->pass, pass);
if (err)
goto out;
sess->estabh = estabh;
sess->arg = arg;
err = stun_server_discover(&sess->dnsq, dnsc,
stun_usage_relay, stun_proto_udp,
af, srv, port, dns_handler, sess);
out:
if (err)
mem_deref(sess);
else
*sessp = sess;
return err;
}
static int media_alloc(struct mnat_media **mp, struct mnat_sess *sess,
int proto, void *sock1, void *sock2,
struct sdp_media *sdpm)
{
struct mnat_media *m;
int err = 0;
if (!mp || !sess || !sdpm)
return EINVAL;
m = mem_zalloc(sizeof(*m), media_destructor);
if (!m)
return ENOMEM;
list_append(&sess->medial, &m->le, m);
m->sdpm = mem_ref(sdpm);
m->sess = sess;
m->sock1 = mem_ref(sock1);
m->sock2 = mem_ref(sock2);
m->proto = proto;
if (sa_isset(&sess->srv, SA_ALL))
err = media_start(sess, m);
if (err)
mem_deref(m);
else {
*mp = m;
++sess->mediac;
}
return err;
}
static int update(struct mnat_sess *sess)
{
struct le *le;
int err = 0;
if (!sess)
return EINVAL;
for (le=sess->medial.head; le; le=le->next) {
struct mnat_media *m = le->data;
struct sa raddr1, raddr2;
raddr1 = *sdp_media_raddr(m->sdpm);
sdp_media_raddr_rtcp(m->sdpm, &raddr2);
if (m->turnc1 && sa_isset(&raddr1, SA_ALL))
err |= turnc_add_chan(m->turnc1, &raddr1, NULL, NULL);
if (m->turnc2 && sa_isset(&raddr2, SA_ALL))
err |= turnc_add_chan(m->turnc2, &raddr2, NULL, NULL);
}
return err;
}
static int module_init(void)
{
return mnat_register(&mnat, baresip_mnatl(),
"turn", NULL, session_alloc, media_alloc,
update);
}
static int module_close(void)
{
mnat = mem_deref(mnat);
return 0;
}
EXPORT_SYM const struct mod_export DECL_EXPORTS(turn) = {
"turn",
"mnat",
module_init,
module_close,
};
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