/* agent must be locked */
static struct ice_candidate_pair *__pair_candidate(struct interface_address *addr, struct ice_agent *ag,
struct ice_candidate *cand, struct packet_stream *ps)
{
struct ice_candidate_pair *pair;
if (addr->family != family_from_address(&cand->endpoint.ip46))
return NULL;
pair = g_slice_alloc0(sizeof(*pair));
pair->agent = ag;
pair->remote_candidate = cand;
pair->local_address = addr;
pair->packet_stream = ps;
if (cand->component_id != 1)
PAIR_SET(pair, FROZEN);
__do_ice_pair_priority(pair);
__new_stun_transaction(pair);
g_queue_push_tail(&ag->candidate_pairs, pair);
g_hash_table_insert(ag->pair_hash, pair, pair);
g_tree_insert(ag->all_pairs, pair, pair);
ilog(LOG_DEBUG, "Created candidate pair "PAIR_FORMAT" between %s and %s, type %s", PAIR_FMT(pair),
smart_ntop_buf(&addr->addr), smart_ntop_ep_buf(&cand->endpoint),
ice_candidate_type_str(cand->type));
return pair;
}
/* agent must NOT be locked, but call must be locked in R */
static void __do_ice_check(struct ice_candidate_pair *pair) {
struct sockaddr_in6 dst;
struct packet_stream *ps = pair->packet_stream;
struct ice_agent *ag = pair->agent;
u_int32_t prio, transact[3];
if (PAIR_ISSET(pair, SUCCEEDED) && !PAIR_ISSET(pair, TO_USE))
return;
if (!ag->pwd[0].s)
return;
ZERO(dst);
dst.sin6_port = htons(pair->remote_candidate->endpoint.port);
dst.sin6_addr = pair->remote_candidate->endpoint.ip46;
dst.sin6_family = AF_INET6;
prio = ice_priority(ICT_PRFLX, pair->local_address->preference,
pair->remote_candidate->component_id);
mutex_lock(&ag->lock);
pair->retransmit = g_now;
if (!PAIR_SET(pair, IN_PROGRESS)) {
PAIR_CLEAR2(pair, FROZEN, FAILED);
pair->retransmit_ms = STUN_RETRANSMIT_INTERVAL;
pair->retransmits = 0;
}
else if (pair->retransmits > STUN_MAX_RETRANSMITS) {
__fail_pair(pair);
mutex_unlock(&ag->lock);
return;
}
else {
pair->retransmit_ms *= 2;
pair->retransmits++;
}
timeval_add_usec(&pair->retransmit, pair->retransmit_ms * 1000);
__agent_schedule_abs(pair->agent, &pair->retransmit);
memcpy(transact, pair->stun_transaction, sizeof(transact));
pair->was_controlling = AGENT_ISSET(ag, CONTROLLING);
pair->was_nominated = PAIR_ISSET(pair, TO_USE);
mutex_unlock(&ag->lock);
ilog(LOG_DEBUG, "Sending %sICE/STUN request for candidate pair "PAIR_FORMAT" from %s to %s",
PAIR_ISSET(pair, TO_USE) ? "nominating " : "",
PAIR_FMT(pair), smart_ntop_buf(&pair->local_address->addr),
smart_ntop_ep_buf(&pair->remote_candidate->endpoint));
stun_binding_request(&dst, transact, &ag->pwd[0], ag->ufrag,
AGENT_ISSET(ag, CONTROLLING), tie_breaker,
prio, &pair->local_address->addr, ps->sfd->fd.fd,
PAIR_ISSET(pair, TO_USE));
}
/* call(W) or call(R)+agent must be locked - no in_lock or out_lock must be held */
static int __check_valid(struct ice_agent *ag) {
struct call_media *media = ag->media;
struct packet_stream *ps;
GList *l, *k;
GQueue all_compos;
struct ice_candidate_pair *pair;
struct interface_address *ifa;
if (!ag) {
ilog(LOG_ERR, "ice ag is NULL");
return 0;
}
__get_complete_valid_pairs(&all_compos, ag);
if (!all_compos.length) {
ilog(LOG_DEBUG, "ICE not completed yet");
return 0;
}
pair = all_compos.head->data;
ilog(LOG_DEBUG, "ICE completed, using pair "PAIR_FORMAT, PAIR_FMT(pair));
AGENT_SET(ag, COMPLETED);
ifa = g_atomic_pointer_get(&media->local_address);
if (ifa != pair->local_address
&& g_atomic_pointer_compare_and_exchange(&media->local_address, ifa,
pair->local_address))
ilog(LOG_INFO, "ICE negotiated: local interface %s", smart_ntop_buf(&pair->local_address->addr));
for (l = media->streams.head, k = all_compos.head; l && k; l = l->next, k = k->next) {
ps = l->data;
pair = k->data;
mutex_lock(&ps->out_lock);
if (memcmp(&ps->endpoint, &pair->remote_candidate->endpoint, sizeof(ps->endpoint))) {
ilog(LOG_INFO, "ICE negotiated: peer for component %u is %s", ps->component,
smart_ntop_ep_buf(&pair->remote_candidate->endpoint));
ps->endpoint = pair->remote_candidate->endpoint;
}
mutex_unlock(&ps->out_lock);
}
call_media_unkernelize(media);
g_queue_clear(&all_compos);
return 1;
}
/* call is locked in R */
int ice_response(struct packet_stream *ps, struct sockaddr_in6 *src, struct in6_addr *dst,
struct stun_attrs *attrs, u_int32_t transaction[3])
{
struct ice_candidate_pair *pair, *opair;
struct ice_agent *ag;
struct call_media *media = ps->media;
const char *err;
unsigned int component;
struct ice_candidate *cand;
struct interface_address *ifa;
int ret, was_ctl;
__DBG("received ICE response from %s on %s", smart_ntop_port_buf(src), smart_ntop_buf(dst));
ag = media->ice_agent;
if (!ag)
return -1;
atomic64_set(&ag->last_activity, poller_now);
mutex_lock(&ag->lock);
pair = g_hash_table_lookup(ag->transaction_hash, transaction);
err = "ICE/STUN response with unknown transaction received";
if (!pair)
goto err_unlock;
was_ctl = pair->was_controlling;
mutex_unlock(&ag->lock);
ifa = pair->local_address;
ilog(LOG_DEBUG, "Received ICE/STUN response code %u for candidate pair "PAIR_FORMAT" from %s to %s",
attrs->error_code, PAIR_FMT(pair),
smart_ntop_ep_buf(&pair->remote_candidate->endpoint),
smart_ntop_buf(&ifa->addr));
/* verify endpoints */
err = "ICE/STUN response received, but source address didn't match remote candidate address";
if (memcmp(&src->sin6_addr, &pair->remote_candidate->endpoint.ip46, sizeof(src->sin6_addr)))
goto err;
if (ntohs(src->sin6_port) != pair->remote_candidate->endpoint.port)
goto err;
err = "ICE/STUN response received, but destination address didn't match local interface address";
if (memcmp(dst, &ifa->addr, sizeof(*dst)))
goto err;
if (pair->packet_stream != ps)
goto err;
PAIR_CLEAR(pair, IN_PROGRESS);
ret = 0;
/* handle all errors */
if (attrs->error_code) {
err = "ICE/STUN error received";
if (attrs->error_code != 487)
goto err;
__role_change(ag, !was_ctl);
__trigger_check(pair);
goto out;
}
/* we don't discover peer reflexive here (RFC 5245 7.1.3.2.1) as we don't expect to be behind NAT */
/* we also skip parts of 7.1.3.2.2 as we don't do server reflexive */
mutex_lock(&ag->lock);
/* check if we're in the final (controlling) phase */
if (pair->was_nominated && PAIR_CLEAR(pair, TO_USE)) {
ilog(LOG_DEBUG, "Setting nominated ICE candidate pair "PAIR_FORMAT" as valid", PAIR_FMT(pair));
PAIR_SET(pair, VALID);
g_tree_insert(ag->valid_pairs, pair, pair);
ret = __check_valid(ag);
goto out_unlock;
}
if (PAIR_SET(pair, SUCCEEDED))
goto out_unlock;
ilog(LOG_DEBUG, "Setting ICE candidate pair "PAIR_FORMAT" as succeeded", PAIR_FMT(pair));
g_tree_insert(ag->succeeded_pairs, pair, pair);
if (!ag->start_nominating.tv_sec) {
if (__check_succeeded_complete(ag)) {
ag->start_nominating = g_now;
timeval_add_usec(&ag->start_nominating, 100000);
__agent_schedule_abs(ag, &ag->start_nominating);
}
}
/* now unfreeze all other pairs from the same foundation */
for (component = 1; component <= MAX_COMPONENTS; component++) {
if (component == ps->component)
continue;
cand = __foundation_lookup(ag, &pair->remote_candidate->foundation, component);
if (!cand)
continue;
opair = __pair_lookup(ag, cand, ifa);
if (!opair)
continue;
if (PAIR_ISSET(opair, FAILED))
continue;
if (!PAIR_CLEAR(opair, FROZEN))
continue;
ilog(LOG_DEBUG, "Unfreezing related ICE pair "PAIR_FORMAT, PAIR_FMT(opair));
}
/* if this was previously nominated by the peer, it's now valid */
if (PAIR_ISSET(pair, NOMINATED)) {
PAIR_SET(pair, VALID);
g_tree_insert(ag->valid_pairs, pair, pair);
if (!AGENT_ISSET(ag, CONTROLLING))
ret = __check_valid(ag);
}
out_unlock:
mutex_unlock(&ag->lock);
out:
return ret;
err_unlock:
mutex_unlock(&ag->lock);
err:
if (err)
ilog(LOG_NOTICE, "%s (from %s on interface %s)",
err, smart_ntop_port_buf(src), smart_ntop_buf(dst));
if (pair && attrs->error_code)
__fail_pair(pair);
return 0;
}
/* return values:
* 1 = ICE completed, interfaces selected
* 0 = packet processed
* -1 = generic error, process packet as normal
* -2 = role conflict
*/
int ice_request(struct packet_stream *ps, struct sockaddr_in6 *src, struct in6_addr *dst,
struct stun_attrs *attrs)
{
struct call_media *media = ps->media;
struct ice_agent *ag;
struct interface_address *ifa;
const char *err;
struct ice_candidate *cand;
struct ice_candidate_pair *pair;
int ret;
__DBG("received ICE request from %s on %s", smart_ntop_port_buf(src), smart_ntop_buf(dst));
ag = media->ice_agent;
if (!ag)
return -1;
atomic64_set(&ag->last_activity, poller_now);
ifa = get_interface_from_address(ag->local_interface, dst);
err = "ICE/STUN binding request received on unknown local interface address";
if (!ifa)
goto err;
/* determine candidate pair */
mutex_lock(&ag->lock);
cand = __cand_lookup(ag, src, ps->component);
if (!cand)
pair = __learned_candidate(ag, ps, src, ifa, attrs->priority);
else
pair = __pair_lookup(ag, cand, ifa);
err = "Failed to determine ICE candidate from STUN request";
if (!pair)
goto err_unlock;
mutex_unlock(&ag->lock);
/* determine role conflict */
if (attrs->controlling && AGENT_ISSET(ag, CONTROLLING)) {
if (tie_breaker >= attrs->tiebreaker)
return -2;
else
__role_change(ag, 0);
}
else if (attrs->controlled && !AGENT_ISSET(ag, CONTROLLING)) {
if (tie_breaker >= attrs->tiebreaker)
__role_change(ag, 1);
else
return -2;
}
if (PAIR_ISSET(pair, SUCCEEDED))
;
else
__trigger_check(pair);
ret = 0;
if (attrs->use && !PAIR_SET(pair, NOMINATED)) {
ilog(LOG_DEBUG, "ICE pair "PAIR_FORMAT" has been nominated by peer", PAIR_FMT(pair));
mutex_lock(&ag->lock);
g_tree_insert(ag->nominated_pairs, pair, pair);
if (PAIR_ISSET(pair, SUCCEEDED)) {
PAIR_SET(pair, VALID);
g_tree_insert(ag->valid_pairs, pair, pair);
}
if (!AGENT_ISSET(ag, CONTROLLING))
ret = __check_valid(ag);
mutex_unlock(&ag->lock);
}
return ret;
err_unlock:
mutex_unlock(&ag->lock);
err:
ilog(LOG_NOTICE, "%s (from %s on interface %s)", err, smart_ntop_port_buf(src), smart_ntop_buf(dst));
return 0;
}
static void insert_candidates(struct sdp_chopper *chop, struct packet_stream *rtp, struct packet_stream *rtcp,
struct sdp_ng_flags *flags, struct sdp_media *sdp_media)
{
GList *l;
struct interface_address *ifa;
unsigned int pref;
struct call_media *media;
struct local_interface *lif;
struct ice_agent *ag;
unsigned int type_pref, local_pref;
enum ice_candidate_type cand_type;
struct ice_candidate *cand;
media = rtp->media;
cand_type = ICT_HOST;
if (flags->ice_force_relay)
cand_type = ICT_RELAY;
if (MEDIA_ISSET(media, PASSTHRU))
new_priority(sdp_media, cand_type, &type_pref, &local_pref);
else {
type_pref = ice_type_preference(cand_type);
local_pref = -1;
}
ag = media->ice_agent;
lif = ag ? ag->local_interface : media->interface;
if (ag && AGENT_ISSET(ag, COMPLETED)) {
ifa = g_atomic_pointer_get(&media->local_address);
insert_candidate(chop, rtp, 1, type_pref, ifa->preference, cand_type, ifa);
if (rtcp) /* rtcp-mux only possible in answer */
insert_candidate(chop, rtcp, 2, type_pref, ifa->preference, cand_type, ifa);
if (flags->opmode == OP_OFFER && AGENT_ISSET(ag, CONTROLLING)) {
GQueue rc;
GList *l;
chopper_append_c(chop, "a=remote-candidates:");
ice_remote_candidates(&rc, ag);
for (l = rc.head; l; l = l->next) {
if (l != rc.head)
chopper_append_c(chop, " ");
cand = l->data;
chopper_append_printf(chop, "%lu %s %u", cand->component_id,
smart_ntop_buf(&cand->endpoint.ip46), cand->endpoint.port);
}
chopper_append_c(chop, "\r\n");
g_queue_clear(&rc);
}
return;
}
for (l = lif->list.head; l; l = l->next) {
ifa = l->data;
pref = (local_pref == -1) ? ifa->preference : local_pref;
insert_candidate(chop, rtp, 1, type_pref, pref, cand_type, ifa);
if (rtcp) /* rtcp-mux only possible in answer */
insert_candidate(chop, rtcp, 2, type_pref, pref, cand_type, ifa);
if (local_pref != -1)
local_pref++;
}
}