-

1 files changed, 2883 insertions, 0 deletions

diff --git a/tinyNET/src/ice/tnet_ice_ctx.c b/tinyNET/src/ice/tnet_ice_ctx.c
new file mode 100644
index 0000000..94d3042
--- /dev/null
+++ b/tinyNET/src/ice/tnet_ice_ctx.c
@@ -0,0 +1,2883 @@
+/*
+ * Copyright (C) 2012-2015 Mamadou DIOP
+ * Copyright (C) 2012-2015 Doubango Telecom <http://www.doubango.org>.
+ *
+ * This file is part of Open Source Doubango Framework.
+ *
+ * DOUBANGO is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * DOUBANGO is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with DOUBANGO.
+ *
+ */
+
+/**@file tnet_ice_ctx.c
+ * @brief Interactive Connectivity Establishment (ICE) implementation as per RFC 5245
+ *
+ */
+#include "tnet_ice_ctx.h"
+#include "tnet_ice_event.h"
+#include "tnet_ice_candidate.h"
+#include "tnet_ice_pair.h"
+#include "tnet_ice_utils.h"
+#include "tnet_utils.h"
+#include "tnet_endianness.h"
+#include "tnet_transport.h"
+#include "tnet_proxydetect.h"
+
+#include "stun/tnet_stun.h"
+#include "stun/tnet_stun_message.h"
+#include "stun/tnet_stun_types.h"
+#include "turn/tnet_turn_session.h"
+
+#include "tsk_condwait.h"
+#include "tsk_time.h"
+#include "tsk_timer.h"
+#include "tsk_runnable.h"
+#include "tsk_memory.h"
+#include "tsk_string.h"
+#include "tsk_fsm.h"
+#include "tsk_debug.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef LONG_MAX
+#	define LONG_MAX      2147483647L
+#endif
+
+#if !defined(TNET_ICE_DEBUG_STATE_MACHINE)
+#	define TNET_ICE_DEBUG_STATE_MACHINE 1
+#endif
+
+/**@ingroup tnet_nat_group
+ * Estimate of the round-trip time (RTT) in millisecond.
+ */
+#define kIceDefaultRTO			500
+/**@ingroup tnet_nat_group
+ * Number of retransmission for UDP retransmission in millisecond.
+ *	7.2.1.  Sending over UDP
+ Rc SHOULD be configurable and SHOULD have a default of 7.
+ */
+#define kIceDefaultRC				4 //7
+
+#define kIceDefaultTurnEnabled			0 // Relay candidates
+#define kIceDefaultStunEnabled			1 // Reflexive candidates
+
+#define kIceCandidatesCountMax	40
+#define kIceServersCountMax		10
+
+#define kIceConnCheckMinTriesMin	0
+#define kIceConnCheckMinTriesMax	3
+
+#define kIcePairsBuildingTimeMax	2500 // maximum time to build pairs
+
+typedef tsk_list_t tnet_ice_servers_L_t;
+
+static const char* foundation_default = tsk_null;
+
+typedef enum tnet_ice_server_proto_e
+{
+    tnet_ice_server_proto_none = 0x00,
+    tnet_ice_server_proto_stun = (0x01 << 0),
+    tnet_ice_server_proto_turn = (0x01 << 1),
+    tnet_ice_server_proto_all = 0xFF
+}
+tnet_ice_server_proto_t;
+
+static int _tnet_ice_ctx_fsm_act(struct tnet_ice_ctx_s* self, tsk_fsm_action_id action_id);
+static int _tnet_ice_ctx_signal_async(struct tnet_ice_ctx_s* self, tnet_ice_event_type_t type, const char* phrase);
+static int _tnet_ice_ctx_cancel(struct tnet_ice_ctx_s* self, tsk_bool_t silent);
+static int _tnet_ice_ctx_restart(struct tnet_ice_ctx_s* self);
+static int _tnet_ice_ctx_recv_stun_message_for_pair(struct tnet_ice_ctx_s* self, const struct tnet_ice_pair_s* pair, const void* data, tsk_size_t size, tnet_fd_t local_fd, const struct sockaddr_storage* remote_addr, tsk_bool_t *role_conflict);
+static int _tnet_ice_ctx_send_turn_raw(struct tnet_ice_ctx_s* self, struct tnet_turn_session_s* turn_ss, tnet_turn_peer_id_t turn_peer_id, const void* data, tsk_size_t size);
+static int _tnet_ice_ctx_build_pairs(struct tnet_ice_ctx_s* self, tnet_ice_candidates_L_t* local_candidates, tnet_ice_candidates_L_t* remote_candidates, tnet_ice_pairs_L_t* result_pairs, tsk_bool_t is_controlling, uint64_t tie_breaker, tsk_bool_t is_ice_jingle, tsk_bool_t is_rtcpmuxed);
+static void* TSK_STDCALL _tnet_ice_ctx_run(void* self);
+
+static int _tnet_ice_ctx_fsm_Started_2_GatheringHostCandidates_X_GatherHostCandidates(va_list *app);
+static int _tnet_ice_ctx_fsm_GatheringHostCandidates_2_GatheringHostCandidatesDone_X_Success(va_list *app);
+static int _tnet_ice_ctx_fsm_GatheringHostCandidates_2_Terminated_X_Failure(va_list *app);
+static int _tnet_ice_ctx_fsm_GatheringHostCandidatesDone_2_GatheringReflexiveCandidates_X_GatherReflexiveCandidates(va_list *app);
+static int _tnet_ice_ctx_fsm_GatheringReflexiveCandidates_2_GatheringReflexiveCandidatesDone_X_Success(va_list *app);
+static int _tnet_ice_ctx_fsm_GatheringReflexiveCandidates_2_Terminated_X_Failure(va_list *app);
+static int _tnet_ice_ctx_fsm_GatheringReflexiveCandidatesDone_2_GatheringRelayCandidates_X_GatherRelayCandidates(va_list *app);
+static int _tnet_ice_ctx_fsm_GatheringRelayCandidates_2_GatheringRelayCandidatesDone_X_Success(va_list *app);
+static int _tnet_ice_ctx_fsm_GatheringRelayCandidates_2_Terminated_X_Failure(va_list *app);
+static int _tnet_ice_ctx_fsm_Any_2_GatheringCompleted_X_GatheringComplet(va_list *app);
+static int _tnet_ice_ctx_fsm_Any_2_Started_X_Cancel(va_list *app);
+static int _tnet_ice_ctx_fsm_GatheringCompleted_2_ConnChecking_X_ConnCheck(va_list *app);
+static int _tnet_ice_ctx_fsm_ConnChecking_2_ConnCheckingCompleted_X_Success(va_list *app);
+static int _tnet_ice_ctx_fsm_ConnChecking_2_Terminated_X_Failure(va_list *app);
+static int _tnet_ice_ctx_fsm_Any_2_Terminated_X_AnyNotStarted(va_list *app); // Any action if not started
+
+static int _tnet_ice_ctx_servers_clear(struct tnet_ice_ctx_s* self);
+static int _tnet_ice_ctx_server_add(struct tnet_ice_ctx_s* self, enum tnet_ice_server_proto_e e_proto,
+                                    enum tnet_socket_type_e e_transport,
+                                    const char* str_server_addr, uint16_t u_server_port,
+                                    const char* str_software,
+                                    const char* str_username, const char* str_password);
+static int _tnet_ice_ctx_server_remove(struct tnet_ice_ctx_s* self, enum tnet_ice_server_proto_e e_proto, enum tnet_socket_type_e e_transport, const char* str_server_addr, uint16_t u_server_port);
+static const struct tnet_ice_server_s* _tnet_ice_ctx_server_find(struct tnet_ice_ctx_s* self, enum tnet_ice_server_proto_e e_proto, enum tnet_socket_type_e e_transport, const char* str_server_addr, uint16_t u_server_port);
+static tsk_bool_t _tnet_ice_ctx_server_exists(struct tnet_ice_ctx_s* self, enum tnet_ice_server_proto_e e_proto, enum tnet_socket_type_e e_transport, const char* str_server_addr, uint16_t u_server_port);
+static tsk_size_t _tnet_ice_ctx_servers_count_by_proto(struct tnet_ice_ctx_s* self, enum tnet_ice_server_proto_e e_proto);
+static tnet_ice_servers_L_t* _tnet_ice_ctx_servers_copy(struct tnet_ice_ctx_s* self, enum tnet_ice_server_proto_e e_proto);
+
+static int _tnet_ice_ctx_fsm_OnTerminated(struct tnet_ice_ctx_s* self);
+static tsk_bool_t _tnet_ice_ctx_fsm_cond_NotStarted(struct tnet_ice_ctx_s* self, const void* _any);
+static int _tnet_ice_ctx_turn_callback(const struct tnet_turn_session_event_xs *e);
+
+typedef struct tnet_ice_server_s
+{
+    TSK_DECLARE_OBJECT;
+    
+    enum tnet_socket_type_e e_transport;
+    tnet_ice_server_proto_t e_proto;
+    char* str_server_addr;
+    uint16_t u_server_port;
+    struct sockaddr_storage obj_server_addr;
+    char* str_software;
+    char* str_username;
+    char* str_password;
+    int rto;
+}
+tnet_ice_server_t;
+
+static tsk_object_t* tnet_ice_server_ctor(tsk_object_t * self, va_list * app)
+{
+    tnet_ice_server_t *ice_server = self;
+    if (ice_server) {
+    }
+    return self;
+}
+static tsk_object_t* tnet_ice_server_dtor(tsk_object_t * self)
+{
+    tnet_ice_server_t *ice_server = self;
+    if (ice_server) {
+        TSK_FREE(ice_server->str_server_addr);
+        TSK_FREE(ice_server->str_software);
+        TSK_FREE(ice_server->str_username);
+        TSK_FREE(ice_server->str_password);
+        
+        TSK_DEBUG_INFO("*** ICE server destroyed ***");
+    }
+    return self;
+}
+static const tsk_object_def_t tnet_ice_server_def_s =
+{
+    sizeof(tnet_ice_server_t),
+    tnet_ice_server_ctor,
+    tnet_ice_server_dtor,
+    tsk_null,
+};
+
+static tnet_ice_server_t* tnet_ice_server_create(
+                                                 enum tnet_ice_server_proto_e e_proto,
+                                                 enum tnet_socket_type_e e_transport,
+                                                 const char* str_server_addr, uint16_t u_server_port,
+                                                 const char* str_software,
+                                                 const char* str_username, const char* str_password)
+{
+    tnet_ice_server_t *ice_server;
+    struct sockaddr_storage obj_server_addr;
+    
+    if (tsk_strnullORempty(str_server_addr) || !u_server_port) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return tsk_null;
+    }
+    
+    if (tnet_sockaddr_init(str_server_addr, u_server_port, e_transport, &obj_server_addr) != 0) {
+        TSK_DEBUG_ERROR("Invalid server address (host=%s, port=%d, transport=%d)", str_server_addr, u_server_port, e_transport);
+        return tsk_null;
+    }
+    
+    if ((ice_server = tsk_object_new(&tnet_ice_server_def_s))) {
+        ice_server->e_proto = e_proto;
+        ice_server->e_transport = e_transport;
+        tsk_strupdate(&ice_server->str_server_addr, str_server_addr);
+        ice_server->u_server_port = u_server_port;
+        tsk_strupdate(&ice_server->str_software, str_software);
+        tsk_strupdate(&ice_server->str_username, str_username);
+        tsk_strupdate(&ice_server->str_password, str_password);
+        memcpy(&ice_server->obj_server_addr, &obj_server_addr, sizeof(struct sockaddr_storage));
+    }
+    return ice_server;
+}
+
+typedef struct tnet_ice_ctx_s
+{
+    TSK_DECLARE_RUNNABLE;
+    
+    tsk_bool_t is_started;
+    tsk_bool_t is_active;
+    tsk_bool_t is_sync_mode;
+    tsk_bool_t is_silent_mode;
+    tnet_ice_callback_f callback;
+    const void* userdata;
+    tsk_bool_t use_ipv6;
+    tsk_bool_t use_rtcp;
+    tsk_bool_t use_rtcpmux;
+    tsk_bool_t is_video;
+    tsk_bool_t is_building_pairs;
+    tsk_bool_t unicast;
+    tsk_bool_t anycast;
+    tsk_bool_t multicast;
+    
+    tsk_bool_t is_connchecking;
+    tsk_bool_t is_controlling;
+    tsk_bool_t is_ice_jingle;
+    tsk_bool_t is_turn_enabled;
+    tsk_bool_t is_stun_enabled;
+    uint64_t tie_breaker;
+    uint64_t concheck_timeout;
+    
+    const void* rtp_callback_data;
+    tnet_ice_rtp_callback_f rtp_callback;
+    
+    tnet_ice_servers_L_t *servers;
+    
+    char* ufrag;
+    char* pwd;
+    
+    tsk_timer_manager_handle_t* h_timer_mgr;
+    
+    tsk_fsm_t* fsm;
+    
+    tsk_condwait_handle_t* condwait_pairs;
+    tnet_ice_candidates_L_t* candidates_local;
+    tnet_ice_candidates_L_t* candidates_remote;
+    tnet_ice_pairs_L_t* candidates_pairs;
+    tsk_bool_t have_nominated_offer;
+    tsk_bool_t have_nominated_answer;
+    tsk_bool_t have_nominated_symetric; /**< Whether symetic RTP has been negotiated */
+    
+    uint16_t RTO; /**< Estimate of the round-trip time (RTT) in millisecond */
+    uint16_t Rc; /**< Number of retransmissions for UDP in millisecond */
+    
+    struct {
+        char* path_priv;
+        char* path_pub;
+        char* path_ca;
+        tsk_bool_t verify;
+    } ssl;
+    
+    struct {
+        tsk_bool_t auto_detect;
+        struct tnet_proxyinfo_s* info;
+    }
+    proxy;
+    
+    struct {
+        tsk_condwait_handle_t* condwait;
+        struct tnet_turn_session_s* ss_nominated_rtp;
+        tnet_turn_peer_id_t peer_id_rtp;
+        struct tnet_turn_session_s* ss_nominated_rtcp;
+        tnet_turn_peer_id_t peer_id_rtcp;
+    } turn;
+    
+    TSK_DECLARE_SAFEOBJ;
+}
+tnet_ice_ctx_t;
+
+typedef struct tnet_ice_action_s
+{
+    TSK_DECLARE_OBJECT;
+    
+    tsk_fsm_action_id id;
+}
+tnet_ice_action_t;
+
+typedef enum _fsm_state_e
+{
+    _fsm_state_Started,
+    _fsm_state_GatheringHostCandidates,
+    _fsm_state_GatheringHostCandidatesDone,
+    _fsm_state_GatheringReflexiveCandidates,
+    _fsm_state_GatheringReflexiveCandidatesDone,
+    _fsm_state_GatheringRelayCandidates,
+    _fsm_state_GatheringRelayCandidatesDone,
+    _fsm_state_GatheringCompleted,
+    _fsm_state_ConnChecking,
+    _fsm_state_ConnCheckingCompleted,
+    _fsm_state_Terminated
+}
+_fsm_state_t;
+
+typedef enum _fsm_action_e
+{
+    _fsm_action_Success,
+    _fsm_action_Failure,
+    _fsm_action_GatherHostCandidates,
+    _fsm_action_GatherReflexiveCandidates,
+    _fsm_action_GatherRelayCandidates,
+    _fsm_action_GatheringComplet,
+    _fsm_action_ConnCheck,
+    _fsm_action_Cancel,
+    _fsm_action_Error,
+}
+_fsm_action_t;
+
+static tsk_object_t* tnet_ice_action_ctor(tsk_object_t * self, va_list * app)
+{
+    tnet_ice_action_t *action = self;
+    if (action){
+    }
+    return self;
+}
+static tsk_object_t* tnet_ice_action_dtor(tsk_object_t * self)
+{
+    tnet_ice_action_t *action = self;
+    if (action){
+    }
+    return self;
+}
+static const tsk_object_def_t tnet_ice_action_def_s =
+{
+    sizeof(tnet_ice_action_t),
+    tnet_ice_action_ctor,
+    tnet_ice_action_dtor,
+    tsk_null,
+};
+static tnet_ice_action_t* tnet_ice_action_create(tsk_fsm_action_id id)
+{
+    tnet_ice_action_t *action = tsk_object_new(&tnet_ice_action_def_s);
+    if (action){
+        action->id = id;
+    }
+    return action;
+}
+
+
+
+
+static tsk_object_t* tnet_ice_ctx_ctor(tsk_object_t * self, va_list * app)
+{
+    tnet_ice_ctx_t *ctx = self;
+    if (ctx){
+        tsk_safeobj_init(ctx);
+        
+        if (!(ctx->h_timer_mgr = tsk_timer_manager_create())){
+            TSK_DEBUG_ERROR("Failed to create timer manager");
+            return tsk_null;
+        }
+        if (!(ctx->fsm = tsk_fsm_create(_fsm_state_Started, _fsm_state_Terminated))){
+            TSK_DEBUG_ERROR("Failed to create state machine");
+            return tsk_null;
+        }
+        if (!(ctx->candidates_local = tsk_list_create())){
+            TSK_DEBUG_ERROR("Failed to create candidates list");
+            return tsk_null;
+        }
+        if (!(ctx->candidates_remote = tsk_list_create())){
+            TSK_DEBUG_ERROR("Failed to create candidates list");
+            return tsk_null;
+        }
+        if (!(ctx->candidates_pairs = tsk_list_create())){
+            TSK_DEBUG_ERROR("Failed to create candidates list");
+            return tsk_null;
+        }
+        
+        // Create condwait for pairs
+        if (!(ctx->condwait_pairs = tsk_condwait_create())) {
+            TSK_DEBUG_ERROR("Failed to create condwait for pairs");
+            return tsk_null;
+        }
+        
+        // Create list objects to hold the servers
+        if (!(ctx->servers = tsk_list_create())){
+            TSK_DEBUG_ERROR("Failed to create server list");
+            return tsk_null;
+        }
+        
+        tsk_runnable_set_important(TSK_RUNNABLE(self), tsk_false);
+        
+        /*	7.2.1.  Sending over UDP
+         In fixed-line access links, a value of 500 ms is RECOMMENDED.
+         */
+        ctx->RTO = kIceDefaultRTO;
+        
+        /*	7.2.1.  Sending over UDP
+         Rc SHOULD be configurable and SHOULD have a default of 7.
+         */
+        ctx->Rc = kIceDefaultRC;
+        
+        ctx->tie_breaker = ((tsk_time_now() << 32) ^ tsk_time_now());
+        ctx->is_ice_jingle = tsk_false;
+        ctx->is_stun_enabled = kIceDefaultStunEnabled;
+        ctx->is_turn_enabled = kIceDefaultTurnEnabled;
+        
+        ctx->concheck_timeout = LONG_MAX;
+    }
+    return self;
+}
+static tsk_object_t* tnet_ice_ctx_dtor(tsk_object_t * self)
+{
+    tnet_ice_ctx_t *ctx = self;
+    if (ctx){
+        tnet_ice_ctx_stop(ctx);
+        if (ctx->h_timer_mgr){
+            tsk_timer_manager_destroy(&ctx->h_timer_mgr);
+        }
+        
+        TSK_OBJECT_SAFE_FREE(ctx->fsm);
+        TSK_OBJECT_SAFE_FREE(ctx->candidates_local);
+        TSK_OBJECT_SAFE_FREE(ctx->candidates_remote);
+        TSK_OBJECT_SAFE_FREE(ctx->candidates_pairs);
+        
+        TSK_OBJECT_SAFE_FREE(ctx->turn.ss_nominated_rtp);
+        TSK_OBJECT_SAFE_FREE(ctx->turn.ss_nominated_rtcp);
+        if (ctx->turn.condwait) {
+            tsk_condwait_destroy(&ctx->turn.condwait);
+        }
+        if (ctx->condwait_pairs) {
+            tsk_condwait_destroy(&ctx->condwait_pairs);
+        }
+        TSK_OBJECT_SAFE_FREE(ctx->servers);
+        
+        TSK_OBJECT_SAFE_FREE(ctx->proxy.info);
+        
+        TSK_FREE(ctx->ssl.path_priv);
+        TSK_FREE(ctx->ssl.path_pub);
+        TSK_FREE(ctx->ssl.path_ca);
+        
+        tsk_safeobj_deinit(ctx);
+    }
+    TSK_DEBUG_INFO("*** ICE context destroyed ***");
+    return self;
+}
+static const tsk_object_def_t tnet_ice_ctx_def_s =
+{
+    sizeof(tnet_ice_ctx_t),
+    tnet_ice_ctx_ctor,
+    tnet_ice_ctx_dtor,
+    tsk_null,
+};
+
+
+tnet_ice_ctx_t* tnet_ice_ctx_create(tsk_bool_t is_ice_jingle, tsk_bool_t use_ipv6, tsk_bool_t use_rtcp, tsk_bool_t is_video, tnet_ice_callback_f callback, const void* userdata)
+{
+    tnet_ice_ctx_t* ctx;
+    
+    if (!(ctx = tsk_object_new(&tnet_ice_ctx_def_s))){
+        TSK_DEBUG_ERROR("Failed to create ICE context object");
+        return tsk_null;
+    }
+    
+    ctx->is_ice_jingle = is_ice_jingle;
+    ctx->use_ipv6 = use_ipv6;
+    ctx->use_rtcp = use_rtcp;
+    ctx->is_video = is_video;
+    ctx->callback = callback;
+    ctx->userdata = userdata;
+    ctx->unicast = tsk_true;
+    ctx->anycast = tsk_false;
+    ctx->multicast = tsk_false;
+    
+    tnet_ice_utils_set_ufrag(&ctx->ufrag);
+    tnet_ice_utils_set_pwd(&ctx->pwd);
+    
+    ctx->fsm->debug = TNET_ICE_DEBUG_STATE_MACHINE;
+    tsk_fsm_set_callback_terminated(ctx->fsm, TSK_FSM_ONTERMINATED_F(_tnet_ice_ctx_fsm_OnTerminated), (const void*)ctx);
+    tsk_fsm_set(ctx->fsm,
+                // (Started) -> (GatherHostCandidates) -> (GatheringHostCandidates)
+                TSK_FSM_ADD_ALWAYS(_fsm_state_Started, _fsm_action_GatherHostCandidates, _fsm_state_GatheringHostCandidates, _tnet_ice_ctx_fsm_Started_2_GatheringHostCandidates_X_GatherHostCandidates, "ICE_Started_2_GatheringHostCandidates_X_GatherHostCandidates"),
+                // (GatheringHostCandidates) -> (Success) -> (GatheringHostCandidatesDone)
+                TSK_FSM_ADD_ALWAYS(_fsm_state_GatheringHostCandidates, _fsm_action_Success, _fsm_state_GatheringHostCandidatesDone, _tnet_ice_ctx_fsm_GatheringHostCandidates_2_GatheringHostCandidatesDone_X_Success, "ICE_GatheringHostCandidates_2_GatheringHostCandidatesDone_X_Success"),
+                // (GatheringHostCandidates) -> (Failure) -> (Terminated)
+                TSK_FSM_ADD_ALWAYS(_fsm_state_GatheringHostCandidates, _fsm_action_Failure, _fsm_state_Terminated, _tnet_ice_ctx_fsm_GatheringHostCandidates_2_Terminated_X_Failure, "ICE_GatheringHostCandidates_2_Terminated_X_Failure"),
+                
+                // (GatheringHostCandidatesDone) -> (GatherReflexiveCandidates) -> (GatheringReflexiveCandidates)
+                TSK_FSM_ADD_ALWAYS(_fsm_state_GatheringHostCandidatesDone, _fsm_action_GatherReflexiveCandidates, _fsm_state_GatheringReflexiveCandidates, _tnet_ice_ctx_fsm_GatheringHostCandidatesDone_2_GatheringReflexiveCandidates_X_GatherReflexiveCandidates, "ICE_GatheringHostCandidatesDone_2_GatheringReflexiveCandidates_X_GatherReflexiveCandidates"),
+                // (GatheringReflexiveCandidates) -> (Success) -> GatheringReflexiveCandidatesDone
+                TSK_FSM_ADD_ALWAYS(_fsm_state_GatheringReflexiveCandidates, _fsm_action_Success, _fsm_state_GatheringReflexiveCandidatesDone, _tnet_ice_ctx_fsm_GatheringReflexiveCandidates_2_GatheringReflexiveCandidatesDone_X_Success, "ICE_fsm_GatheringReflexiveCandidates_2_GatheringReflexiveCandidatesDone_X_Success"),
+                // (GatheringReflexiveCandidates) -> (Failure) -> Terminated
+                TSK_FSM_ADD_ALWAYS(_fsm_state_GatheringReflexiveCandidates, _fsm_action_Failure, _fsm_state_Terminated, _tnet_ice_ctx_fsm_GatheringReflexiveCandidates_2_Terminated_X_Failure, "ICE_GatheringReflexiveCandidates_2_Terminated_X_Failure"),
+                
+                // (GatheringReflexiveCandidatesDone) -> (GatherRelayCandidates) -> (GatheringRelayCandidates)
+                TSK_FSM_ADD_ALWAYS(_fsm_state_GatheringReflexiveCandidatesDone, _fsm_action_GatherRelayCandidates, _fsm_state_GatheringRelayCandidates, _tnet_ice_ctx_fsm_GatheringReflexiveCandidatesDone_2_GatheringRelayCandidates_X_GatherRelayCandidates, "ICE_GatheringReflexiveCandidatesDone_2_GatheringRelayCandidates_X_GatherRelayCandidates"),
+                // (GatheringHostCandidatesDone) -> (GatherRelayCandidates) -> (GatheringRelayCandidates)
+                TSK_FSM_ADD_ALWAYS(_fsm_state_GatheringHostCandidatesDone, _fsm_action_GatherRelayCandidates, _fsm_state_GatheringRelayCandidates, _tnet_ice_ctx_fsm_GatheringReflexiveCandidatesDone_2_GatheringRelayCandidates_X_GatherRelayCandidates, "ICE_GatheringHostCandidatesDone_2_GatheringRelayCandidates_X_GatherRelayCandidates"),
+                // (GatheringRelayCandidates) -> (Success) -> GatheringRelayCandidatesDone
+                TSK_FSM_ADD_ALWAYS(_fsm_state_GatheringRelayCandidates, _fsm_action_Success, _fsm_state_GatheringRelayCandidatesDone, _tnet_ice_ctx_fsm_GatheringRelayCandidates_2_GatheringRelayCandidatesDone_X_Success, "ICE_fsm_GatheringRelayCandidates_2_GatheringRelayCandidatesDone_X_Success"),
+                // (GatheringRelayCandidates) -> (Failure) -> Terminated
+                TSK_FSM_ADD_ALWAYS(_fsm_state_GatheringRelayCandidates, _fsm_action_Failure, _fsm_state_Terminated, _tnet_ice_ctx_fsm_GatheringRelayCandidates_2_Terminated_X_Failure, "ICE_GatheringRelayCandidates_2_Terminated_X_Failure"),
+                
+                // (GatheringComplet) -> (ConnCheck) -> ConnChecking
+                TSK_FSM_ADD_ALWAYS(_fsm_state_GatheringCompleted, _fsm_action_ConnCheck, _fsm_state_ConnChecking, _tnet_ice_ctx_fsm_GatheringCompleted_2_ConnChecking_X_ConnCheck, "ICE_GatheringCompleted_2_ConnChecking_X_ConnCheck"),
+                // (ConnChecking) -> (Success) -> ConnCheckingCompleted
+                TSK_FSM_ADD_ALWAYS(_fsm_state_ConnChecking, _fsm_action_Success, _fsm_state_ConnCheckingCompleted, _tnet_ice_ctx_fsm_ConnChecking_2_ConnCheckingCompleted_X_Success, "ICE_ConnChecking_2_ConnCheckingCompleted_X_Success"),
+                // (ConnChecking) -> (Failure) -> Terminated
+                TSK_FSM_ADD_ALWAYS(_fsm_state_ConnChecking, _fsm_action_Failure, _fsm_state_Terminated, _tnet_ice_ctx_fsm_ConnChecking_2_Terminated_X_Failure, "ICE_ConnChecking_2_Terminated_X_Failure"),
+                
+                // (Any) -> (GatheringComplet) -> GatheringCompleted
+                TSK_FSM_ADD_ALWAYS(tsk_fsm_state_any, _fsm_action_GatheringComplet, _fsm_state_GatheringCompleted, _tnet_ice_ctx_fsm_Any_2_GatheringCompleted_X_GatheringComplet, "ICE_Any_2_GatheringCompleted_X_GatheringComplet"),
+                // (Any) -> (Cancel) -> Started
+                TSK_FSM_ADD_ALWAYS(tsk_fsm_state_any, _fsm_action_Cancel, _fsm_state_Started, _tnet_ice_ctx_fsm_Any_2_Started_X_Cancel, "ICE_Any_2_Started_X_Cancel"),
+                // (Any) -> (AnyNotStarted) -> Terminated
+                TSK_FSM_ADD(tsk_fsm_state_any, tsk_fsm_action_any, _tnet_ice_ctx_fsm_cond_NotStarted, _fsm_state_Terminated, _tnet_ice_ctx_fsm_Any_2_Terminated_X_AnyNotStarted, "ICE_fsm_Any_2_Terminated_X_AnyNotStarted")
+                );
+    
+    return ctx;
+}
+
+int tnet_ice_ctx_set_userdata(tnet_ice_ctx_t* self, const void* userdata)
+{
+    if (!self){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    self->userdata = userdata;
+    return 0;
+}
+
+// @deprecated: use "tnet_ice_ctx_add_server()"
+int tnet_ice_ctx_set_stun(
+                          tnet_ice_ctx_t* self,
+                          const char* server_addr,
+                          uint16_t server_port,
+                          const char* software,
+                          const char* username,
+                          const char* password)
+{
+    _tnet_ice_ctx_servers_clear(self);
+    return tnet_ice_ctx_add_server(
+                                   self,
+                                   "udp",
+                                   server_addr,
+                                   server_port,
+                                   (!tsk_strnullORempty(username) && !tsk_strnullORempty(password)), /* use_turn*/
+                                   tsk_true, /* use_stun*/
+                                   username,
+                                   password);
+}
+
+int tnet_ice_ctx_add_server(
+                            struct tnet_ice_ctx_s* self,
+                            const char* transport_proto, // "udp", "tcp", "tls", "ws", "wss"
+                            const char* server_addr,
+                            uint16_t server_port,
+                            tsk_bool_t use_turn,
+                            tsk_bool_t use_stun,
+                            const char* username,
+                            const char* password)
+{
+    tnet_socket_type_t socket_type;
+    tnet_ice_server_proto_t e_proto = tnet_ice_server_proto_none;
+    if (!self || tsk_strnullORempty(server_addr) || !server_port) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    if (!use_turn && !use_stun) {
+        TSK_DEBUG_ERROR("'use_stun' or 'use_turn' must be true");
+        return -1;
+    }
+    if (use_stun) {
+        e_proto |= tnet_ice_server_proto_stun;
+    }
+    if (use_turn) {
+        e_proto |= tnet_ice_server_proto_turn;
+    }
+    
+    if (tsk_striequals(transport_proto, "udp")) {
+        socket_type = self->use_ipv6 ? tnet_socket_type_udp_ipv6 : tnet_socket_type_udp_ipv4;
+    }
+    else if (tsk_striequals(transport_proto, "tcp")) {
+        socket_type = self->use_ipv6 ? tnet_socket_type_tcp_ipv6 : tnet_socket_type_tcp_ipv4;
+    }
+    else if (tsk_striequals(transport_proto, "tls")) {
+        socket_type = self->use_ipv6 ? tnet_socket_type_tls_ipv6 : tnet_socket_type_tls_ipv4;
+    }
+    else if (tsk_striequals(transport_proto, "ws")) {
+        socket_type = self->use_ipv6 ? tnet_socket_type_ws_ipv6 : tnet_socket_type_ws_ipv4;
+    }
+    else if (tsk_striequals(transport_proto, "wss")) {
+        socket_type = self->use_ipv6 ? tnet_socket_type_wss_ipv6 : tnet_socket_type_wss_ipv4;
+    }
+    else {
+        TSK_DEBUG_ERROR("'%s' not a valid transport proto", transport_proto);
+        return -1;
+    }
+    return _tnet_ice_ctx_server_add(self, e_proto,
+                                    socket_type, server_addr, server_port,
+                                    kStunSoftware,
+                                    username, password);
+}
+
+int tnet_ice_ctx_set_sync_mode(tnet_ice_ctx_t* self, tsk_bool_t sync_mode)
+{
+    if (!self){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    self->is_sync_mode = sync_mode;
+    return 0;
+}
+
+int tnet_ice_ctx_set_silent_mode(struct tnet_ice_ctx_s* self, tsk_bool_t silent_mode)
+{
+    if (!self){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    self->is_silent_mode = silent_mode;
+    return 0;
+}
+
+// Whether to gather reflexive candidates
+int tnet_ice_ctx_set_stun_enabled(struct tnet_ice_ctx_s* self, tsk_bool_t stun_enabled)
+{
+    if (!self){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    self->is_stun_enabled = stun_enabled;
+    return 0;
+}
+
+// Whether to gather relay candidates
+int tnet_ice_ctx_set_turn_enabled(struct tnet_ice_ctx_s* self, tsk_bool_t turn_enabled)
+{
+    if (!self){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    self->is_turn_enabled = turn_enabled;
+    return 0;
+}
+
+int tnet_ice_ctx_start(tnet_ice_ctx_t* self)
+{
+    int ret;
+    tsk_bool_t timer_mgr_started = tsk_false;
+    tsk_bool_t runnable_started = tsk_false;
+    const char* err = tsk_null;
+    
+    if (!self){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    
+    tsk_safeobj_lock(self);
+    
+    TSK_DEBUG_INFO("tnet_ice_ctx_start");
+    
+    if (self->is_started){
+        ret = 0;
+        if (!self->is_active){
+            TSK_DEBUG_INFO("ICE restart");
+            ret = _tnet_ice_ctx_restart(self);
+        }
+        TSK_DEBUG_INFO("ICE already started");
+        tsk_safeobj_unlock(self);
+        return ret;
+    }
+    
+    /* === Timer manager === */
+    if ((ret = tsk_timer_manager_start(self->h_timer_mgr))){
+        err = "Failed to start timer manager";
+        TSK_DEBUG_ERROR("%s", err);
+        goto bail;
+    }
+    timer_mgr_started = tsk_true;
+    
+    /* === Runnable === */
+    TSK_RUNNABLE(self)->run = _tnet_ice_ctx_run;
+    if ((ret = tsk_runnable_start(TSK_RUNNABLE(self), tnet_ice_event_def_t))){
+        err = "Failed to start runnable";
+        TSK_DEBUG_ERROR("%s", err);
+        goto bail;
+    }
+    runnable_started = tsk_true;
+    
+    self->is_started = tsk_true; // needed by FSM -> "Must" be before fsm_ast()
+    self->is_active = tsk_true;
+    
+    if ((ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_GatherHostCandidates))){
+        err = "FSM execution failed";
+        TSK_DEBUG_ERROR("%s", err);
+        goto bail;
+    }
+    
+bail:
+    tsk_safeobj_unlock(self);
+    
+    if (ret){
+        _tnet_ice_ctx_signal_async(self, tnet_ice_event_type_start_failed, err);
+        if (timer_mgr_started){
+            tsk_timer_manager_stop(self->h_timer_mgr);
+        }
+        if (runnable_started){
+            tsk_runnable_stop(TSK_RUNNABLE(self));
+        }
+        self->is_started = tsk_false;
+        self->is_active = tsk_false;
+    }
+    return ret;
+}
+
+// register callback to call when we receive early RTP packets while negotaiating ICE pairs
+int tnet_ice_ctx_rtp_callback(tnet_ice_ctx_t* self, tnet_ice_rtp_callback_f rtp_callback, const void* rtp_callback_data)
+{
+    if (!self){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    
+    self->rtp_callback_data = rtp_callback_data;
+    self->rtp_callback = rtp_callback;
+    return 0;
+}
+
+// timeout (millis): <=0 to disable
+int tnet_ice_ctx_set_concheck_timeout(tnet_ice_ctx_t* self, int64_t timeout)
+{
+    if (!self){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    
+    self->concheck_timeout = (timeout <= 0 ? LONG_MAX : timeout);
+    
+    return 0;
+}
+
+// @param candidates (candidate \r\n)+
+int tnet_ice_ctx_set_remote_candidates_2(struct tnet_ice_ctx_s* self, const char* candidates, const char* ufrag, const char* pwd, tsk_bool_t is_controlling, tsk_bool_t is_ice_jingle, tsk_bool_t use_rtcpmux)
+{
+    int ret = 0;
+    char *v, *copy, *saveptr;
+    tsk_size_t size, idx = 0;
+    tsk_bool_t exists;
+    tnet_ice_candidate_t* candidate;
+    tsk_strings_L_t *added_candidates = tsk_null;
+    if (!self) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    
+    self->is_controlling = is_controlling;
+    self->is_ice_jingle = is_ice_jingle;
+    tnet_ice_ctx_set_rtcpmux(self, use_rtcpmux);
+    
+    if (tsk_strnullORempty(candidates)) {
+        // remote party is ICE-lite or doesn't support ICE
+        return tnet_ice_ctx_cancel(self);
+    }
+    
+    TSK_DEBUG_INFO("tnet_ice_ctx_set_remote_candidates(ufrag=%s, pwd=%s, is_controlling=%d, is_ice_jingle=%d, use_rtcpmux=%d)",
+                   ufrag, pwd, is_controlling, is_ice_jingle, use_rtcpmux);
+    
+    tsk_list_lock(self->candidates_pairs);
+    if (!TSK_LIST_IS_EMPTY(self->candidates_pairs)) {
+        TSK_DEBUG_WARN("Adding Remote ICE candidates after pairs building");
+    }
+    tsk_list_unlock(self->candidates_pairs);
+    
+    // active if remote is full-ICE
+    // in all case we are always full-ICE
+    // self->is_active = tsk_true;
+    
+    tsk_list_lock(self->candidates_remote);
+    
+    // clear old candidates
+    tsk_list_clear_items(self->candidates_remote);
+    
+    copy = tsk_strdup(candidates);
+    size = (tsk_size_t)tsk_strlen(copy);
+    do {
+        v = tsk_strtok_r(&copy[idx], "\r\n", &saveptr);
+        idx += tsk_strlen(v) + 2;
+        if (v && (candidate = tnet_ice_candidate_parse(v))) {
+            exists = tsk_false;
+            if (!added_candidates) {
+                added_candidates = tsk_list_create();
+            }
+            if (ufrag && pwd) {
+                tnet_ice_candidate_set_credential(candidate, ufrag, pwd);
+            }
+            if (added_candidates) {
+                tsk_string_t* str_cand = tsk_string_create(tnet_ice_candidate_tostring(candidate));
+                if (str_cand) {
+                    if ((exists = !!tsk_list_find_object_by_data(added_candidates, str_cand))) {
+                        TSK_DEBUG_INFO("Remote candidate [[%s]] is duplicated ...skipping", str_cand->value);
+                    }
+                    else {
+                        tsk_list_push_back_data(added_candidates, (void**)&str_cand);
+                    }
+                    TSK_OBJECT_SAFE_FREE(str_cand);
+                }
+            }
+            if (!exists) {
+                tsk_list_push_descending_data(self->candidates_remote, (void**)&candidate);
+            }
+            TSK_OBJECT_SAFE_FREE(candidate);
+        }
+    } while (v && (idx < size));
+    
+    tsk_list_unlock(self->candidates_remote);
+    
+    TSK_FREE(copy);
+    TSK_OBJECT_SAFE_FREE(added_candidates);
+    
+    if (!tnet_ice_ctx_is_connected(self) && tnet_ice_ctx_got_local_candidates(self) && !TSK_LIST_IS_EMPTY(self->candidates_remote)) {
+        ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_ConnCheck);
+    }
+    return ret;
+}
+
+// @param candidates (candidate \r\n)+
+int tnet_ice_ctx_set_remote_candidates(tnet_ice_ctx_t* self, const char* candidates, const char* ufrag, const char* pwd, tsk_bool_t is_controlling, tsk_bool_t is_ice_jingle)
+{
+    return tnet_ice_ctx_set_remote_candidates_2(self, candidates, ufrag, pwd, is_controlling, is_ice_jingle, self->use_rtcpmux);
+}
+
+int tnet_ice_ctx_set_rtcpmux(tnet_ice_ctx_t* self, tsk_bool_t use_rtcpmux)
+{
+    if (!self) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    if (self->is_connchecking && self->use_rtcpmux != use_rtcpmux) {
+        TSK_DEBUG_WARN("use_rtcpmux changed(%d->%d) while connchecking", self->use_rtcpmux, use_rtcpmux);
+    }
+    self->use_rtcpmux = use_rtcpmux;
+    return 0;
+}
+
+int tnet_ice_ctx_set_ssl_certs(struct tnet_ice_ctx_s* self, const char* path_priv, const char* path_pub, const char* path_ca, tsk_bool_t verify)
+{
+    if (!self) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    tsk_strupdate(&self->ssl.path_priv, path_priv);
+    tsk_strupdate(&self->ssl.path_pub, path_pub);
+    tsk_strupdate(&self->ssl.path_ca, path_ca);
+    self->ssl.verify = verify;
+    return 0;
+}
+
+tsk_size_t tnet_ice_ctx_count_local_candidates(const tnet_ice_ctx_t* self)
+{
+    if (!self){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return 0;
+    }
+    return tsk_list_count(self->candidates_local, tsk_null, tsk_null);
+}
+
+tsk_bool_t tnet_ice_ctx_got_local_candidates(const tnet_ice_ctx_t* self)
+{
+    tsk_fsm_state_id curr_state;
+    if (!self){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return tsk_false;
+    }
+    if (!self->is_started){
+        return tsk_false;
+    }
+    
+    curr_state = tsk_fsm_get_current_state(self->fsm);
+    
+    return (curr_state >= _fsm_state_GatheringCompleted && curr_state < _fsm_state_Terminated);
+}
+
+const tnet_ice_candidate_t* tnet_ice_ctx_get_local_candidate_at(const tnet_ice_ctx_t* self, tsk_size_t index)
+{
+    const tsk_list_item_t *item;
+    tsk_size_t pos = 0;
+    if (!self){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return tsk_null;
+    }
+    
+    tsk_list_foreach(item, self->candidates_local){
+        if (pos++ == index){
+            return (const tnet_ice_candidate_t*)item->data;
+        }
+    }
+    return tsk_null;
+}
+
+tsk_bool_t tnet_ice_ctx_is_started(const tnet_ice_ctx_t* self)
+{
+    return (self && self->is_started);
+}
+
+// says if ICE is enabled
+// doesn't say if the connection has been negotiated (see is_connecte())
+tsk_bool_t tnet_ice_ctx_is_active(const tnet_ice_ctx_t* self)
+{
+    return (self && self->is_started && self->is_active);
+}
+
+tsk_bool_t tnet_ice_ctx_is_turn_rtp_active(const struct tnet_ice_ctx_s* self)
+{
+    tsk_bool_t b_active;
+    return tnet_ice_ctx_is_active(self)
+    && self->turn.ss_nominated_rtp
+    && tnet_turn_session_is_active(self->turn.ss_nominated_rtp, self->turn.peer_id_rtp, &b_active) == 0
+    && b_active;
+}
+
+tsk_bool_t tnet_ice_ctx_is_turn_rtcp_active(const struct tnet_ice_ctx_s* self)
+{
+    if (self->use_rtcpmux) {
+        return tnet_ice_ctx_is_turn_rtp_active(self);
+    }
+    else {
+        tsk_bool_t b_active;
+        return tnet_ice_ctx_is_active(self)
+        && self->turn.ss_nominated_rtcp
+        && tnet_turn_session_is_active(self->turn.ss_nominated_rtcp, self->turn.peer_id_rtcp, &b_active) == 0
+        && b_active;
+    }
+}
+
+// says if media can start in both direction
+tsk_bool_t tnet_ice_ctx_is_connected(const tnet_ice_ctx_t* self)
+{
+    return (self && self->have_nominated_symetric);
+}
+
+tsk_bool_t tnet_ice_ctx_is_can_send(const tnet_ice_ctx_t* self)
+{
+    return (self && self->have_nominated_offer);
+}
+
+tsk_bool_t tnet_ice_ctx_is_can_recv(const tnet_ice_ctx_t* self)
+{
+    return (self && self->have_nominated_answer);
+}
+
+tsk_bool_t tnet_ice_ctx_use_ipv6(const tnet_ice_ctx_t* self)
+{
+    return (self && self->use_ipv6);
+}
+
+tsk_bool_t tnet_ice_ctx_use_rtcp(const tnet_ice_ctx_t* self)
+{
+    return (self && self->use_rtcp);
+}
+
+int tnet_ice_ctx_get_nominated_symetric_candidates(const tnet_ice_ctx_t* self, uint32_t comp_id,
+                                                   const tnet_ice_candidate_t** candidate_offer,
+                                                   const tnet_ice_candidate_t** candidate_answer_src,
+                                                   const tnet_ice_candidate_t** candidate_answer_dest)
+{
+    if (!self){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    return tnet_ice_pairs_get_nominated_symetric_candidates(self->candidates_pairs, comp_id, candidate_offer, candidate_answer_src, candidate_answer_dest);
+}
+
+int tnet_ice_ctx_recv_stun_message(tnet_ice_ctx_t* self, const void* data, tsk_size_t size, tnet_fd_t local_fd, const struct sockaddr_storage* remote_addr, tsk_bool_t *role_conflict)
+{
+    static const tnet_ice_pair_t* kNullPair = tsk_null; // means seach for the pair using local_fd and remote_addr
+    return _tnet_ice_ctx_recv_stun_message_for_pair(self, kNullPair, data, size, local_fd, remote_addr, role_conflict);
+}
+
+int tnet_ice_ctx_send_turn_rtp(struct tnet_ice_ctx_s* self, const void* data, tsk_size_t size)
+{
+    return _tnet_ice_ctx_send_turn_raw(self, self->turn.ss_nominated_rtp, self->turn.peer_id_rtp, data, size);
+}
+
+int tnet_ice_ctx_send_turn_rtcp(struct tnet_ice_ctx_s* self, const void* data, tsk_size_t size)
+{
+    return self->use_rtcpmux
+    ? tnet_ice_ctx_send_turn_rtp(self, data, size)
+    : _tnet_ice_ctx_send_turn_raw(self, self->turn.ss_nominated_rtcp, self->turn.peer_id_rtcp, data, size);
+}
+
+int tnet_ice_ctx_turn_get_bytes_count(const struct tnet_ice_ctx_s* self, uint64_t* bytes_in, uint64_t* bytes_out)
+{
+    int ret;
+    
+    if (!self) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    ret = tnet_turn_session_get_bytes_count(self->turn.ss_nominated_rtp, bytes_in, bytes_out);
+    if (ret == 0 && !self->use_rtcpmux) {
+        uint64_t _bytes_in, _bytes_out;
+        ret = tnet_turn_session_get_bytes_count(self->turn.ss_nominated_rtcp, &_bytes_in, &_bytes_out);
+        if (ret == 0) {
+            if (bytes_in) *bytes_in += _bytes_in;
+            if (bytes_out) *bytes_out += _bytes_out;
+        }
+    }
+    return ret;
+}
+
+const char* tnet_ice_ctx_get_ufrag(const struct tnet_ice_ctx_s* self)
+{
+    return (self && self->ufrag) ? self->ufrag : tsk_null;
+}
+
+const char* tnet_ice_ctx_get_pwd(const struct tnet_ice_ctx_s* self)
+{
+    return (self && self->pwd) ? self->pwd : tsk_null;
+}
+
+int tnet_ice_ctx_set_proxy_auto_detect(struct tnet_ice_ctx_s* self, tsk_bool_t auto_detect)
+{
+    if (!self) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    self->proxy.auto_detect = auto_detect;
+    return 0;
+}
+
+int tnet_ice_ctx_set_proxy_info(struct tnet_ice_ctx_s* self, enum tnet_proxy_type_e type, const char* host, tnet_port_t port, const char* login, const char* password)
+{
+    if (!self) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    if (!self->proxy.info && !(self->proxy.info = tnet_proxyinfo_create())) {
+        return -2;
+    }
+    self->proxy.info->type = type;
+    self->proxy.info->port = port;
+    tsk_strupdate(&self->proxy.info->hostname, host);
+    tsk_strupdate(&self->proxy.info->username, login);
+    tsk_strupdate(&self->proxy.info->password, password);
+    return 0;
+}
+
+// cancels the ICE processing without stopping the process
+int tnet_ice_ctx_cancel(tnet_ice_ctx_t* self)
+{
+    int ret;
+    
+    if (!self) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    
+    tsk_safeobj_lock(self);
+    if (tsk_fsm_get_current_state(self->fsm) == _fsm_state_Started) {
+        // Do nothing if already in the "started" state
+        ret = 0;
+        goto bail;
+    }
+    
+    self->is_active = tsk_false;
+    self->have_nominated_symetric = tsk_false;
+    self->have_nominated_answer = tsk_false;
+    self->have_nominated_offer = tsk_false;
+    tsk_condwait_broadcast(self->condwait_pairs);
+    if (self->turn.condwait) {
+        ret = tsk_condwait_broadcast(self->turn.condwait);
+    }
+    ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_Cancel);
+    
+bail:
+    tsk_safeobj_unlock(self);
+    return ret;
+}
+
+int tnet_ice_ctx_stop(tnet_ice_ctx_t* self)
+{
+    int ret;
+    
+    if (!self) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    
+    tsk_safeobj_lock(self);
+    if (!self->is_started) {
+        ret = 0;
+        goto bail;
+    }
+    
+    self->is_started = tsk_false;
+    tsk_condwait_broadcast(self->condwait_pairs);
+    if (self->turn.condwait) {
+        ret = tsk_condwait_broadcast(self->turn.condwait);
+    }
+    ret = tsk_timer_manager_stop(self->h_timer_mgr);
+    ret = tsk_runnable_stop(TSK_RUNNABLE(self));
+    
+bail:
+    tsk_safeobj_unlock(self);
+    return ret;
+}
+
+//--------------------------------------------------------
+//				== STATE MACHINE BEGIN ==
+//--------------------------------------------------------
+
+// Started -> (GatherHostCandidates) -> (GatheringHostCandidates)
+static int _tnet_ice_ctx_fsm_Started_2_GatheringHostCandidates_X_GatherHostCandidates(va_list *app)
+{
+    int ret = 0;
+    tnet_ice_ctx_t* self;
+    tnet_addresses_L_t* addresses;
+    const tsk_list_item_t *item;
+    const tnet_address_t* address;
+    tnet_ice_candidate_t* candidate;
+    tnet_socket_t* socket_rtp = tsk_null;
+    tnet_socket_t* socket_rtcp = tsk_null;
+    tnet_socket_type_t socket_type;
+    uint16_t local_pref, curr_local_pref;
+    tnet_ip_t best_local_ip;
+    tsk_bool_t check_best_local_ip;
+    static const tsk_bool_t dnsserver = tsk_false;
+    static const long if_index_any = -1; // any interface
+    static const char* destination = "doubango.org";
+    
+    self = va_arg(*app, tnet_ice_ctx_t *);
+    socket_type = self->use_ipv6 ? tnet_socket_type_udp_ipv6 : tnet_socket_type_udp_ipv4;
+    
+    addresses = tnet_get_addresses((self->use_ipv6 ? AF_INET6 : AF_INET), self->unicast, self->anycast, self->multicast, dnsserver, if_index_any);
+    if (!addresses || TSK_LIST_IS_EMPTY(addresses)){
+        TSK_DEBUG_ERROR("Failed to get addresses");
+        ret = -1;
+        goto bail;
+    }
+    
+    
+    check_best_local_ip = (tnet_getbestsource(destination, 5060, socket_type, &best_local_ip) == 0);
+    curr_local_pref = local_pref = check_best_local_ip ? 0xFFFE : 0xFFFF;
+    
+    // lock-list
+    tsk_list_lock(self->candidates_local);
+    // clear-list
+    tsk_list_clear_items(self->candidates_local);
+    
+    tsk_list_foreach(item, addresses){
+        if (!(address = item->data)){
+            continue;
+        }
+        
+        // Skip loopback address to avoid problems :)
+        if ((address->family == AF_INET && tsk_striequals(address->ip, "127.0.0.1")) || (address->family == AF_INET6 && tsk_striequals(address->ip, "::1"))){
+            continue;
+        }
+        
+        // host candidates
+        ret = tnet_ice_utils_create_sockets(socket_type,
+                                            address->ip, &socket_rtp,
+                                            self->use_rtcp ? &socket_rtcp : tsk_null);
+        if (ret == 0){
+            const char* foundation_rtp = foundation_default;
+            tsk_list_lock(self->candidates_local);
+            if (socket_rtp){
+                if ((candidate = tnet_ice_candidate_create(tnet_ice_cand_type_host, socket_rtp, self->is_ice_jingle, tsk_true, self->is_video, self->ufrag, self->pwd, foundation_default))){
+                    foundation_rtp = (const char*)candidate->foundation;
+                    if (check_best_local_ip && (candidate->socket && (tsk_striequals(candidate->socket->ip, best_local_ip)))){
+                        curr_local_pref = 0xFFFF;
+                        check_best_local_ip = tsk_false;
+                        tnet_ice_candidate_set_local_pref(candidate, curr_local_pref);
+                        tsk_list_push_front_data(self->candidates_local, (void**)&candidate);
+                    }
+                    else{
+                        curr_local_pref = local_pref--;
+                        tnet_ice_candidate_set_local_pref(candidate, curr_local_pref);
+                        tsk_list_push_back_data(self->candidates_local, (void**)&candidate);
+                    }
+                }
+            }
+            if (socket_rtcp){
+                if ((candidate = tnet_ice_candidate_create(tnet_ice_cand_type_host, socket_rtcp, self->is_ice_jingle, tsk_false, self->is_video, self->ufrag, self->pwd, foundation_rtp))){
+                    tnet_ice_candidate_set_local_pref(candidate, curr_local_pref);
+                    tsk_list_push_back_data(self->candidates_local, (void**)&candidate);
+                }
+            }
+            tsk_list_unlock(self->candidates_local);
+        }
+        
+        TSK_OBJECT_SAFE_FREE(socket_rtp);
+        TSK_OBJECT_SAFE_FREE(socket_rtcp);
+        
+        // break if no longer running
+        if (!self->is_started){
+            break;
+        }
+        
+        TSK_DEBUG_INFO("local ip address = %s", address->ip);
+    }
+    
+    // unlock-list
+    tsk_list_unlock(self->candidates_local);
+    
+bail:
+    if (self->is_started){
+        if (ret == 0 && !TSK_LIST_IS_EMPTY(self->candidates_local)){
+            ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_Success);
+        }
+        else{
+            ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_Failure);
+        }
+    }
+    
+    TSK_OBJECT_SAFE_FREE(addresses);
+    return ret;
+}
+
+// GatheringHostCandidates -> (Success) -> (GatheringHostCandidatesDone)
+static int _tnet_ice_ctx_fsm_GatheringHostCandidates_2_GatheringHostCandidatesDone_X_Success(va_list *app)
+{
+    int ret;
+    tnet_ice_ctx_t* self;
+    
+    self = va_arg(*app, tnet_ice_ctx_t *);
+    
+    ret = _tnet_ice_ctx_signal_async(self, tnet_ice_event_type_gathering_host_candidates_succeed, "Gathering host candidates succeed");
+    if (ret == 0) {
+        if (self->is_stun_enabled && _tnet_ice_ctx_servers_count_by_proto(self, tnet_ice_server_proto_stun) > 0) {
+            TSK_DEBUG_INFO("ICE-STUN enabled and we have STUN servers");
+            ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_GatherReflexiveCandidates);
+        }
+        else {
+            if (self->is_turn_enabled && _tnet_ice_ctx_servers_count_by_proto(self, tnet_ice_server_proto_turn) > 0) {
+                TSK_DEBUG_INFO("ICE-TURN enabled and we have STUN servers");
+                ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_GatherRelayCandidates);
+            }
+            else {
+                TSK_DEBUG_INFO("Do not gather reflexive/relayed candidates because ICE-STUN/TURN is disabled or no server defined");
+                ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_GatheringComplet);
+            }
+        }
+    }
+    
+    return ret;
+}
+
+// GatheringHostCandidates -> (Failure) -> (Terminated)
+static int _tnet_ice_ctx_fsm_GatheringHostCandidates_2_Terminated_X_Failure(va_list *app)
+{
+    tnet_ice_ctx_t* self;
+    
+    self = va_arg(*app, tnet_ice_ctx_t *);
+    return _tnet_ice_ctx_signal_async(self, tnet_ice_event_type_gathering_host_candidates_failed, "Gathering host candidates failed");
+}
+
+// GatheringHostCandidatesDone -> (GatherReflexiveCandidate) -> GatheringReflexiveCandidates
+static int _tnet_ice_ctx_fsm_GatheringHostCandidatesDone_2_GatheringReflexiveCandidates_X_GatherReflexiveCandidates(va_list *app)
+{
+    /*	RFC 5389 - 7.2.1.  Sending over UDP
+     STUN indications are not retransmitted; thus, indication transactions over UDP
+     are not reliable.
+     */
+    int ret = 0;
+    tnet_ice_servers_L_t* ice_servers = tsk_null;
+    tnet_ice_server_t* ice_server;
+    tnet_ice_ctx_t* self;
+    uint16_t i, k, rc;
+    struct timeval tv;
+    tnet_stun_pkt_resp_t *response = tsk_null;
+    const tsk_list_item_t *item, *item_server;
+    tnet_ice_candidate_t* candidate;
+    tnet_fd_t fds[kIceCandidatesCountMax] = { TNET_INVALID_FD }; // -1, then zeros
+    tnet_fd_t fds_skipped[kIceCandidatesCountMax] = { TNET_INVALID_FD }; // -1, then zeros
+    uint16_t fds_count = 0;
+    tnet_fd_t fd_max = -1;
+    fd_set set;
+    tsk_size_t srflx_addr_count_added = 0, srflx_addr_count_skipped = 0, host_addr_count = 0;
+    long tv_sec, tv_usec; //very important to save these values as timeval could be modified by select() - happens on iOS -
+    
+    self = va_arg(*app, tnet_ice_ctx_t *);
+    
+    // Get ICE servers to use to gather reflexive candidates
+    ice_servers = _tnet_ice_ctx_servers_copy(self, tnet_ice_server_proto_stun);
+    if (!ice_servers || TSK_LIST_IS_EMPTY(ice_servers)) { // not expected to be null or empty because we checked the number of such servers before calling this transition
+        TSK_DEBUG_WARN("No valid STUN server could be used to gather reflexive candidates");
+        goto bail;
+    }
+    
+    // set all default values to -1
+    // = {{ -1 }} will only set the first element
+    for (i = 0; i < sizeof(fds) / sizeof(fds[0]); ++i) {
+        fds[i] = TNET_INVALID_FD;
+    }
+    for (i = 0; i < sizeof(fds_skipped) / sizeof(fds_skipped[0]); ++i) {
+        fds_skipped[i] = TNET_INVALID_FD;
+    }
+    
+    rc = self->Rc;
+    tv.tv_sec = tv_sec = 0;
+    tv.tv_usec = tv_usec = 0;
+    
+    // load fds for both rtp and rtcp sockets
+    tsk_list_foreach(item, self->candidates_local) {
+        if (!(candidate = item->data)) {
+            continue;
+        }
+        
+        ++host_addr_count;
+        if ((fds_count < sizeof(fds) / sizeof(fds[0])) && candidate->socket) {
+            fds[fds_count++] = candidate->socket->fd;
+            if (candidate->socket->fd > fd_max) {
+                fd_max = candidate->socket->fd;
+            }
+        }
+    }
+    
+    
+    /*	RFC 5389 - 7.2.1.  Sending over UDP
+     A client SHOULD retransmit a STUN request message starting with an
+     interval of RTO ("Retransmission TimeOut"), doubling after each
+     retransmission.
+     
+     e.g. 0 ms, 500 ms, 1500 ms, 3500 ms, 7500ms, 15500 ms, and 31500 ms
+     */
+    for (i = 0; (i < rc && self->is_started && ((srflx_addr_count_added + srflx_addr_count_skipped) < host_addr_count)); ++i) {
+        // Try gathering the reflexive candidate for each server
+        tsk_list_foreach(item_server, ice_servers) {
+            if (!self->is_started) {
+                break;
+            }
+            if (!(ice_server = item_server->data)) {
+                continue; // must never happen
+            }
+            if (i == 0) {
+                ice_server->rto = 0;
+            }
+            else if (i == 1) {
+                ice_server->rto = self->RTO;
+            }
+            // else // ice_server->rto <<= 1;
+            tv_sec = ice_server->rto / 1000;
+            tv_usec = (ice_server->rto % 1000) * 1000;
+            if (tv_usec >= 1000000) { // > 1000000 is invalid and produce EINVAL when passed to select(iOS)
+                tv_usec -= 1000000;
+                tv_sec++;
+            }
+            // restore values for new select
+            tv.tv_sec = tv_sec;
+#if TNET_UNDER_APPLE
+            tv.tv_usec = (__darwin_suseconds_t)tv_usec;
+#else
+            tv.tv_usec = tv_usec;
+#endif
+            
+            TSK_DEBUG_INFO("ICE reflexive candidates gathering ...srv_addr=%s,srv_port=%u,tv_sec=%lu,tv_usec=%lu,rto=%d", ice_server->str_server_addr, ice_server->u_server_port, tv_sec, tv_usec, ice_server->rto);
+            
+            FD_ZERO(&set);
+            for (k = 0; k < fds_count; ++k) {
+                FD_SET(fds[k], &set);
+            }
+            
+            // sends STUN binding requets
+            tsk_list_foreach(item, self->candidates_local){
+                if (!(candidate = (tnet_ice_candidate_t*)item->data)) {
+                    continue;
+                }
+                if (candidate->socket && tsk_strnullORempty(candidate->stun.srflx_addr)) {
+                    ret = tnet_ice_candidate_send_stun_bind_request(candidate, &ice_server->obj_server_addr, ice_server->str_username, ice_server->str_password);
+                }
+            }
+            
+            if ((ret = select(fd_max + 1, &set, NULL, NULL, &tv)) < 0) {
+                TSK_DEBUG_ERROR("select() failed with error code = %d", tnet_geterrno());
+                goto bail;
+            }
+            else if (ret == 0) {
+                // timeout
+                TSK_DEBUG_INFO("STUN request timedout at %d, rc = %d, rto=%d", i, rc - 1, ice_server->rto);
+                ice_server->rto <<= 1;
+                continue;
+            }
+            else if (ret > 0) {
+                // there is data to read
+                for (k = 0; k < fds_count; ++k) {
+                    tnet_fd_t fd = fds[k];
+                    if (FD_ISSET(fd, &set)) {
+                        unsigned int len = 0;
+                        void* data = 0;
+                        const tnet_ice_candidate_t* candidate_curr;
+                        
+                        // Check how many bytes are pending
+                        if ((ret = tnet_ioctlt(fd, FIONREAD, &len)) < 0) {
+                            TSK_DEBUG_ERROR("tnet_ioctlt() failed");
+                            continue;
+                        }
+                        
+                        if (len == 0) {
+                            TSK_DEBUG_INFO("tnet_ioctlt() retured zero bytes");
+                            continue;
+                        }
+                        
+                        // Receive pending data
+                        data = tsk_calloc(len, sizeof(uint8_t));
+                        if ((ret = tnet_sockfd_recv(fd, data, len, 0)) < 0) {
+                            TSK_FREE(data);
+                            
+                            TSK_DEBUG_ERROR("Recving STUN dgrams failed with error code:%d", tnet_geterrno());
+                            continue;
+                        }
+                        
+                        // Parse the incoming response
+                        if ((ret = tnet_stun_pkt_read(data, (tsk_size_t)ret, &response))) {
+                            TSK_FREE(data);
+                            continue;
+                        }
+                        TSK_FREE(data);
+                        if (response) {
+                            ret = 0;
+                            if ((candidate_curr = tnet_ice_candidate_find_by_fd(self->candidates_local, fd))) {
+                                if (tsk_strnullORempty(candidate_curr->stun.srflx_addr)) { // "srflx" candidate?
+                                    ret = tnet_ice_candidate_process_stun_response((tnet_ice_candidate_t*)candidate_curr, response, fd);
+                                    if (!tsk_strnullORempty(candidate_curr->stun.srflx_addr)) { // ...and now (after processing the response)...is it "srflx" candidate?
+                                        if (tsk_striequals(candidate_curr->connection_addr, candidate_curr->stun.srflx_addr) && candidate_curr->port == candidate_curr->stun.srflx_port) {
+                                            tsk_size_t j;
+                                            tsk_bool_t already_skipped = tsk_false;
+                                            /* refc 5245- 4.1.3.  Eliminating Redundant Candidates
+                                             
+                                             Next, the agent eliminates redundant candidates.  A candidate is
+                                             redundant if its transport address equals another candidate, and its
+                                             base equals the base of that other candidate.  Note that two
+                                             candidates can have the same transport address yet have different
+                                             bases, and these would not be considered redundant.  Frequently, a
+                                             server reflexive candidate and a host candidate will be redundant
+                                             when the agent is not behind a NAT.  The agent SHOULD eliminate the
+                                             redundant candidate with the lower priority. */
+                                            for (j = 0; (fds_skipped[j] != TNET_INVALID_FD && j < (sizeof(fds_skipped) / sizeof(fds_skipped[0]))); ++j) {
+                                                if (fds_skipped[j] == fd) {
+                                                    already_skipped = tsk_true;
+                                                    break;
+                                                }
+                                            }
+                                            
+                                            if (!already_skipped) {
+                                                ++srflx_addr_count_skipped;
+                                                fds_skipped[j] = fd;
+                                            }
+                                            TSK_DEBUG_INFO("Skipping redundant candidate address=%s and port=%d, fd=%d, already_skipped(%u)=%s",
+                                                           candidate_curr->stun.srflx_addr,
+                                                           candidate_curr->stun.srflx_port,
+                                                           fd,
+                                                           (unsigned)j, already_skipped ? "yes" : "no");
+                                        }
+                                        else {
+                                            char* foundation = tsk_strdup(TNET_ICE_CANDIDATE_TYPE_SRFLX);
+                                            tnet_ice_candidate_t* new_cand;
+                                            tsk_strcat(&foundation, (const char*)candidate_curr->foundation);
+                                            new_cand = tnet_ice_candidate_create(tnet_ice_cand_type_srflx, candidate_curr->socket, candidate_curr->is_ice_jingle, candidate_curr->is_rtp, self->is_video, self->ufrag, self->pwd, foundation);
+                                            TSK_FREE(foundation);
+                                            if (new_cand) {
+                                                ++srflx_addr_count_added;
+                                                tsk_list_lock(self->candidates_local);
+                                                tnet_ice_candidate_set_rflx_addr(new_cand, candidate_curr->stun.srflx_addr, candidate_curr->stun.srflx_port);
+                                                tsk_list_push_descending_data(self->candidates_local, (void**)&new_cand);
+                                                tsk_list_unlock(self->candidates_local);
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                        TSK_OBJECT_SAFE_FREE(response);
+                    }
+                }
+            }
+            else {
+                continue;
+            }
+        } // tsk_list_foreach (item, ice_servers)...
+    } // for (i = 0; (i < rc....
+    
+bail:
+    TSK_DEBUG_INFO("srflx_addr_count_added=%u, srflx_addr_count_skipped=%u", (unsigned)srflx_addr_count_added, (unsigned)srflx_addr_count_skipped);
+    if ((srflx_addr_count_added + srflx_addr_count_skipped) > 0) ret = 0; // Hack the returned value if we have at least one success (happens when timeouts)
+    if (self->is_started) {
+        if (ret == 0) {
+            ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_Success);
+        }
+        else{
+            ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_Failure);
+        }
+    }
+    
+    tsk_list_foreach(item, self->candidates_local) {
+        if (!(candidate = (tnet_ice_candidate_t*)item->data)) {
+            continue;
+        }
+        TSK_DEBUG_INFO("Candidate: %s", tnet_ice_candidate_tostring(candidate));
+    }
+    TSK_OBJECT_SAFE_FREE(ice_servers);
+    return ret;
+}
+
+// GatheringReflexiveCandidates -> (Success) -> GatheringReflexiveCandidatesDone
+static int _tnet_ice_ctx_fsm_GatheringReflexiveCandidates_2_GatheringReflexiveCandidatesDone_X_Success(va_list *app)
+{
+    tnet_ice_ctx_t* self;
+    
+    self = va_arg(*app, tnet_ice_ctx_t *);
+    
+    if (self->is_started) {
+        int ret = _tnet_ice_ctx_signal_async(self, tnet_ice_event_type_gathering_reflexive_candidates_succeed, "Gathering reflexive candidates succeed");
+        if (ret == 0) {
+            enum _fsm_action_e action_next = _fsm_action_GatheringComplet;
+            if (self->is_turn_enabled) {
+                if (_tnet_ice_ctx_servers_count_by_proto(self, tnet_ice_server_proto_turn) == 0) {
+                    TSK_DEBUG_WARN("TURN is enabled but no TURN server could be found");
+                }
+                else {
+                    action_next = _fsm_action_GatherRelayCandidates;
+                }
+            }
+            ret = _tnet_ice_ctx_fsm_act(self, action_next);
+        }
+        return ret;
+    }
+    else {
+        return -1;
+    }
+}
+
+// GatheringReflexiveCandidates -> (Failure) -> Terminated
+static int _tnet_ice_ctx_fsm_GatheringReflexiveCandidates_2_Terminated_X_Failure(va_list *app)
+{
+    tnet_ice_ctx_t* self = va_arg(*app, tnet_ice_ctx_t *);
+    return _tnet_ice_ctx_signal_async(self, tnet_ice_event_type_gathering_reflexive_candidates_failed, "Gathering reflexive candidates failed");
+}
+
+// GatheringReflexiveCandidatesDone -> (GatherRelayCandidates) -> GatheringRelayCandidates
+static int _tnet_ice_ctx_fsm_GatheringReflexiveCandidatesDone_2_GatheringRelayCandidates_X_GatherRelayCandidates(va_list *app)
+{
+    tnet_ice_ctx_t* self = va_arg(*app, tnet_ice_ctx_t *);
+    int ret = 0;
+    tsk_list_item_t *item, *item_server = tsk_null;
+    tnet_ice_candidate_t* candidate;
+    uint16_t i, rto, rc;
+    tsk_size_t relay_addr_count_ok = 0, relay_addr_count_nok = 0, relay_addr_count_added = 0, host_addr_count = 0;
+    uint64_t u_t0, u_t1;
+    enum tnet_stun_state_e e_tunrn_state;
+    tnet_ice_servers_L_t* ice_servers = tsk_null;
+    tnet_ice_server_t* ice_server;
+    tnet_ice_candidates_L_t* candidates_local_copy = tsk_null;;
+    
+    // Create TURN condwait handle if not already done
+    if (!self->turn.condwait && !(self->turn.condwait = tsk_condwait_create())) {
+        TSK_DEBUG_ERROR("Failed to create TURN condwait handle");
+        ret = -2;
+        goto bail;
+    }
+    
+    // Copy local ICE candidates
+    tsk_list_lock(self->candidates_local);
+    candidates_local_copy = tsk_list_clone(self->candidates_local);
+    tsk_list_unlock(self->candidates_local);
+    
+    // Take reference to the TURN servers
+    ice_servers = _tnet_ice_ctx_servers_copy(self, tnet_ice_server_proto_turn);
+    if (!ice_servers || TSK_LIST_IS_EMPTY(ice_servers)) {
+        TSK_DEBUG_WARN("TURN enabled but no server could be found"); // should never happen...but who knows?
+        goto bail;
+    }
+next_server:
+    if (!self->is_started) {
+        goto bail;
+    }
+    relay_addr_count_ok = 0, relay_addr_count_nok = 0, relay_addr_count_added = 0, host_addr_count = 0;
+    if (!item_server) {
+        item_server = ice_servers->head;
+    }
+    else {
+        item_server = item_server->next;
+    }
+    if (!item_server) {
+        TSK_DEBUG_INFO("We have reached the end of TURN servers");
+        goto bail;
+    }
+    ice_server = (tnet_ice_server_t*)item_server->data;
+    
+    // Create TURN sessions for each local host candidate
+    tsk_list_foreach(item, candidates_local_copy) {
+        if (!(candidate = item->data)) {
+            continue;
+        }
+        TSK_DEBUG_INFO("Gathering relay candidate: local addr=%s=%d, TURN server=%s:%d", candidate->connection_addr, candidate->port, ice_server->str_server_addr, ice_server->u_server_port);
+        
+        // Destroy previvious TURN session (if exist)
+        TSK_OBJECT_SAFE_FREE(candidate->turn.ss);
+        if (candidate->type_e == tnet_ice_cand_type_host && candidate->socket) { // do not create TURN session for reflexive candidates
+            // create the TURN session
+            // FIXME: For now we support UDP relaying only (like Chrome): more info at https://groups.google.com/forum/#!topic/turn-server-project-rfc5766-turn-server/vR_2OAV9a_w
+            // This is not an issue even if both peers requires TCP/TLS connection to the TURN server. UDP relaying will be local to the servers.
+            //
+            static enum tnet_turn_transport_e __e_req_transport = tnet_turn_transport_udp; // We should create two TURN sessions: #1 UDP relay + #1 TCP relay
+            if ((ret = tnet_turn_session_create_4(candidate->socket, __e_req_transport, ice_server->str_server_addr, ice_server->u_server_port, ice_server->e_transport, &candidate->turn.ss))) {
+                continue;
+            }
+            // set TURN callback
+            if ((ret = tnet_turn_session_set_callback(candidate->turn.ss, _tnet_ice_ctx_turn_callback, self))) {
+                continue;
+            }
+            // set SSL certificates
+            if ((ret = tnet_turn_session_set_ssl_certs(candidate->turn.ss, self->ssl.path_priv, self->ssl.path_pub, self->ssl.path_ca, self->ssl.verify))) {
+                continue;
+            }
+            // WebProxy
+            if ((ret = tnet_turn_session_set_proxy_auto_detect(candidate->turn.ss, self->proxy.auto_detect))) {
+                continue;
+            }
+            if ((ret = tnet_turn_session_set_proxy_info(candidate->turn.ss, self->proxy.info))) {
+                continue;
+            }
+            // set TURN credentials
+            if ((ret = tnet_turn_session_set_cred(candidate->turn.ss, ice_server->str_username, ice_server->str_password))) {
+                continue;
+            }
+            // prepare()
+            if ((ret = tnet_turn_session_prepare(candidate->turn.ss))) {
+                continue;
+            }
+            // start()
+            if ((ret = tnet_turn_session_start(candidate->turn.ss))) {
+                continue;
+            }
+            // allocate()
+            if ((ret = tnet_turn_session_allocate(candidate->turn.ss))) {
+                continue;
+            }
+            ++host_addr_count;
+        }
+    } // tsk_list_foreach(item, self->candidates_local) {
+    
+    rto = self->RTO;
+    rc = self->Rc;
+    
+    for (i = 0; (i < rc && self->is_started && ((relay_addr_count_ok + relay_addr_count_nok) < host_addr_count));) {
+        if (!self->is_started || !self->is_active) {
+            TSK_DEBUG_INFO("ICE context stopped/cancelled while gathering TURN candidates");
+            goto bail;
+        }
+        
+        u_t0 = tsk_time_now();
+        tsk_condwait_timedwait(self->turn.condwait, rto);
+        u_t1 = tsk_time_now();
+        if ((u_t1 - u_t0) >= rto) {
+            // timedwait() -> timedout
+            rto <<= 1;
+            ++i;
+        }
+        
+        // count the number of TURN sessions with alloc() = ok/nok and ignore ones without response
+        relay_addr_count_ok = 0;
+        tsk_list_foreach(item, candidates_local_copy) {
+            if (!(candidate = item->data) || !candidate->turn.ss) {
+                continue;
+            }
+            if ((ret = tnet_turn_session_get_state_alloc(candidate->turn.ss, &e_tunrn_state))) {
+                goto bail;
+            }
+            if (e_tunrn_state == tnet_stun_state_ok) {
+                ++relay_addr_count_ok;
+            }
+            else if (e_tunrn_state == tnet_stun_state_nok) {
+                TSK_OBJECT_SAFE_FREE(candidate->turn.ss); // delete the session
+                ++relay_addr_count_nok;
+            }
+        }
+    }
+    
+    // add/delete TURN candidates
+    tsk_list_foreach(item, candidates_local_copy) {
+        if (!(candidate = item->data) || !candidate->turn.ss) {
+            continue;
+        }
+        if ((ret = tnet_turn_session_get_state_alloc(candidate->turn.ss, &e_tunrn_state))) {
+            goto bail;
+        }
+        if (e_tunrn_state == tnet_stun_state_ok) {
+            static tsk_bool_t __b_ipv6;
+            char* foundation = tsk_null;
+            char* relay_addr = tsk_null;
+            tnet_port_t relay_port;
+            tnet_ice_candidate_t* new_cand = tsk_null;
+            struct tnet_socket_s* p_lcl_sock = tsk_null;
+            
+            if ((ret = tnet_turn_session_get_relayed_addr(candidate->turn.ss, &relay_addr, &relay_port, &__b_ipv6))) {
+                goto bail;
+            }
+            if (tsk_striequals(candidate->connection_addr, relay_addr) && candidate->port == relay_port) {
+                TSK_DEBUG_INFO("Skipping redundant candidate address=%s and port=%d", relay_addr, relay_port);
+                TSK_FREE(relay_addr);
+                continue;
+            }
+            if ((ret = tnet_turn_session_get_socket_local(candidate->turn.ss, &p_lcl_sock))) {
+                goto bail;
+            }
+            tsk_strcat_2(&foundation, "%s%s", TNET_ICE_CANDIDATE_TYPE_RELAY, (const char*)candidate->foundation);
+            new_cand = tnet_ice_candidate_create(tnet_ice_cand_type_relay, p_lcl_sock, candidate->is_ice_jingle, candidate->is_rtp, self->is_video, self->ufrag, self->pwd, foundation);
+            TSK_FREE(foundation);
+            TSK_OBJECT_SAFE_FREE(p_lcl_sock);
+            if (new_cand) {
+                tsk_list_lock(self->candidates_local);
+                new_cand->turn.ss = candidate->turn.ss, candidate->turn.ss = tsk_null;
+                new_cand->turn.relay_addr = relay_addr, relay_addr = tsk_null;
+                new_cand->turn.relay_port = relay_port;
+                tnet_ice_candidate_set_rflx_addr(new_cand, new_cand->turn.relay_addr, new_cand->turn.relay_port);
+                tsk_list_push_descending_data(self->candidates_local, (void**)&new_cand);
+                tsk_list_unlock(self->candidates_local);
+                ++relay_addr_count_added;
+            }
+            TSK_FREE(relay_addr);
+        }
+        else {
+            TSK_OBJECT_SAFE_FREE(candidate->turn.ss);
+        }
+    }
+    
+    // Try next TURN server
+    if (self->is_started && item_server && relay_addr_count_added == 0) {
+        goto next_server;
+    }
+    
+bail:
+    if (self->is_started) {
+        if (ret == 0) {
+            ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_Success);
+        }
+        else {
+            ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_Failure);
+        }
+    }
+    TSK_OBJECT_SAFE_FREE(ice_servers);
+    TSK_OBJECT_SAFE_FREE(candidates_local_copy);
+    return ret;
+}
+
+// GatheringRelayCandidates -> (Success) -> GatheringRelayCandidatesDone
+static int _tnet_ice_ctx_fsm_GatheringRelayCandidates_2_GatheringRelayCandidatesDone_X_Success(va_list *app)
+{
+    tnet_ice_ctx_t* self = va_arg(*app, tnet_ice_ctx_t *);
+    if (self->is_started) {
+        // Relay candidates are the last ones -> gathering is competed
+        return _tnet_ice_ctx_fsm_act(self, _fsm_action_GatheringComplet);
+    }
+    else {
+        return -1;
+    }
+}
+
+// GatheringReflexiveCandidates -> (Failure) -> Terminated
+static int _tnet_ice_ctx_fsm_GatheringRelayCandidates_2_Terminated_X_Failure(va_list *app)
+{
+    tnet_ice_ctx_t* self = va_arg(*app, tnet_ice_ctx_t *);
+    return _tnet_ice_ctx_signal_async(self, tnet_ice_event_type_gathering_relay_candidates_failed, "Gathering relay candidates failed");
+}
+
+// Any -> (Cancel) -> Started
+static int _tnet_ice_ctx_fsm_Any_2_Started_X_Cancel(va_list *app)
+{
+    tnet_ice_ctx_t* self;
+    self = va_arg(*app, tnet_ice_ctx_t *);
+    
+    tsk_list_lock(self->candidates_remote);
+    tsk_list_clear_items(self->candidates_remote);
+    tsk_list_unlock(self->candidates_remote);
+    
+    tsk_list_lock(self->candidates_pairs);
+    tsk_list_clear_items(self->candidates_pairs);
+    tsk_list_unlock(self->candidates_pairs);
+    
+    TSK_OBJECT_SAFE_FREE(self->turn.ss_nominated_rtp);
+    TSK_OBJECT_SAFE_FREE(self->turn.ss_nominated_rtcp);
+    
+    // Do not clear local candidates because then will be used as fallback if the remote peer is an ICE-lite
+    // These candidates will be cleared before the next local gathering
+    // tsk_list_lock(self->candidates_local);
+    // tsk_list_clear_items(self->candidates_local);
+    // tsk_list_unlock(self->candidates_local);
+    
+    // restore "is_cancelled" until next cancel
+    // set "is_active" to false to allow ICE re-start
+    // self->is_cancelled = tsk_false;
+    // self->is_active = tsk_false;
+    
+    // alert user
+    _tnet_ice_ctx_signal_async(self, tnet_ice_event_type_cancelled, "Cancelled");
+    
+    return 0;
+    
+}
+
+// Any -> (GatheringComplet) -> GatheringCompleted
+static int _tnet_ice_ctx_fsm_Any_2_GatheringCompleted_X_GatheringComplet(va_list *app)
+{
+    int ret = 0;
+    tnet_ice_ctx_t* self;
+    tsk_bool_t has_remote_candidates;
+    
+    self = va_arg(*app, tnet_ice_ctx_t *);
+    
+    // alert user
+    _tnet_ice_ctx_signal_async(self, tnet_ice_event_type_gathering_completed, "Gathering candidates completed");
+    
+    if (self->is_started){
+        tsk_list_lock(self->candidates_remote);
+        has_remote_candidates = !TSK_LIST_IS_EMPTY(self->candidates_remote);
+        tsk_list_unlock(self->candidates_remote);
+        
+        if (has_remote_candidates){
+            ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_ConnCheck);
+        }
+    }
+    else{
+        return -1;
+    }
+    
+    return ret;
+}
+
+// GatheringComplet -> (ConnCheck) -> ConnChecking
+static int _tnet_ice_ctx_fsm_GatheringCompleted_2_ConnChecking_X_ConnCheck(va_list *app)
+{
+    // Implements:
+    // 5.8. Scheduling Checks
+#if !defined(FD_SETSIZE)
+#define FD_SETSIZE 64
+#endif
+    int ret, err;
+    const tsk_list_item_t *item;
+    tnet_ice_ctx_t* self;
+    tnet_fd_t fds[FD_SETSIZE] = { -1 };
+    tnet_fd_t fds_turn[FD_SETSIZE] = { -1 };
+    uint16_t fds_count = 0, fds_turn_count = 0, k;
+    tnet_fd_t fd_max = -1;
+    fd_set set;
+    const tnet_ice_pair_t *pair;
+    struct timeval tv;
+    static const long rto = 160; // milliseconds
+    struct sockaddr_storage remote_addr;
+    uint64_t time_start, time_curr = 0, time_end = 0, concheck_timeout = 0;
+    tsk_bool_t role_conflict, restart_conneck, check_rtcp, isset, got_hosts;
+    void* recvfrom_buff_ptr = tsk_null;
+    tsk_size_t recvfrom_buff_size = 0, tries_count = 0, tries_count_min = kIceConnCheckMinTriesMin;
+    enum tnet_stun_state_e e_state;
+    
+    self = va_arg(*app, tnet_ice_ctx_t *);
+    
+    self->is_connchecking = tsk_true;
+    
+    // "tries_count" and "tries_count_min"
+    // The connection checks to to the "relay", "prflx", "srflx" and "host" candidates are sent at the same time.
+    // Because the requests are sent at the same time it's possible to have success check for "relay" (or "srflx") candidates before the "host" candidates.
+    // "tries_count_min" is the minimum (if success check is not for "host" candidates) tries before giving up.
+    // The pairs are already sorted ("host"->"srflx"->"prflx", "relay") to make sure to choose the best candidates when there are more than one success conncheck.
+    
+start_conneck:
+    role_conflict = tsk_false;
+    restart_conneck = tsk_false;
+    
+    tsk_list_lock(self->candidates_pairs);
+    tsk_list_clear_items(self->candidates_pairs);
+    tsk_list_unlock(self->candidates_pairs);
+    
+    TSK_OBJECT_SAFE_FREE(self->turn.ss_nominated_rtp);
+    TSK_OBJECT_SAFE_FREE(self->turn.ss_nominated_rtcp);
+    
+    if ((ret = _tnet_ice_ctx_build_pairs(self, self->candidates_local, self->candidates_remote, self->candidates_pairs, self->is_controlling, self->tie_breaker, self->is_ice_jingle, self->use_rtcpmux))) {
+        TSK_DEBUG_ERROR("_tnet_ice_ctx_build_pairs() failed");
+        goto bail;
+    }
+    
+#define _FD_ISSET(_fds, _fds_count, _fd, _isset) { uint16_t __i; *_isset = 0; for (__i = 0; __i < _fds_count; ++__i) { if (_fds[__i] == _fd) { *_isset = 1; break; } } }
+    
+    // load fds for both rtp and rtcp sockets / create TURN permissions
+    tsk_list_lock(self->candidates_pairs);
+    tsk_list_foreach(item, self->candidates_pairs){
+        if (!(pair = item->data) || !pair->candidate_offer || !pair->candidate_offer->socket){
+            continue;
+        }
+        
+        if ((fds_count < sizeof(fds) / sizeof(fds[0])) && pair->candidate_offer->socket) {
+            if (pair->candidate_offer->turn.ss && (ret = tnet_turn_session_get_state_createperm(pair->candidate_offer->turn.ss, pair->turn_peer_id, &e_state)) == 0) {
+                if (e_state == tnet_stun_state_none) {
+                    ret = tnet_turn_session_createpermission(((tnet_ice_pair_t *)pair)->candidate_offer->turn.ss, pair->candidate_answer->connection_addr, pair->candidate_answer->port, &((tnet_ice_pair_t *)pair)->turn_peer_id);
+                    if (ret) {
+                        continue;
+                        // goto bail;
+                    }
+                }
+                fds_turn[fds_turn_count++] = pair->candidate_offer->socket->fd;
+                // When TURN is active the socket (host) is pulled in the TURN session and any incoming data will be forwarded to us.
+                // Do not add fd to the set
+                continue;
+            }
+            _FD_ISSET(fds, fds_count, pair->candidate_offer->socket->fd, &isset); // not in the set -> to avoid doubloon
+            if (!isset) {
+                _FD_ISSET(fds_turn, fds_turn_count, pair->candidate_offer->socket->fd, &isset); // not already managed by a TURN session
+                if (!isset) {
+                    fds[fds_count++] = pair->candidate_offer->socket->fd;
+                    if (pair->candidate_offer->socket->fd > fd_max) {
+                        fd_max = pair->candidate_offer->socket->fd;
+                    }
+                }
+            }
+        }
+    }
+    tsk_list_unlock(self->candidates_pairs);
+    
+    concheck_timeout = self->concheck_timeout;
+    time_start = time_curr = tsk_time_now();
+    time_end = (time_start + concheck_timeout);
+    tries_count_min = fds_turn_count > 0 ? kIceConnCheckMinTriesMax : kIceConnCheckMinTriesMin;
+    
+    while (self->is_started && self->is_active && (time_curr < time_end) && !self->have_nominated_symetric) {
+        tv.tv_sec = 0;
+        tv.tv_usec = (rto * 1000);
+        
+        FD_ZERO(&set);
+        for (k = 0; k < fds_count; ++k) {
+            FD_SET(fds[k], &set);
+        }
+        
+        // set new current time here to avoid "continue" skips
+        // ignore already ellapsed time if new timeout value is defined
+        time_curr = tsk_time_now();
+        if (self->concheck_timeout != concheck_timeout) {
+            concheck_timeout = self->concheck_timeout;
+            time_start = time_curr;
+            time_end = (time_start + concheck_timeout);
+        }
+        
+        // Send ConnCheck requests
+        // the pairs are already sorted by priority (from high to low)
+        if (!self->have_nominated_symetric) {
+            tsk_list_foreach(item, self->candidates_pairs) {
+                if (!(pair = item->data) || !pair->candidate_offer || !pair->candidate_offer->socket) {
+                    continue;
+                }
+                switch (pair->state_offer) {
+                    case tnet_ice_pair_state_failed:
+                    case tnet_ice_pair_state_succeed:
+                        continue;
+                    default: break;
+                }
+                
+                ret = tnet_ice_pair_send_conncheck((tnet_ice_pair_t *)pair);
+            }
+        }
+        
+        if (fds_count == 0) {
+            tsk_thread_sleep(10);
+            goto check_nomination;
+        }
+        
+        if ((ret = select(fd_max + 1, &set, NULL, NULL, &tv)) < 0) {
+            TNET_PRINT_LAST_ERROR("select() failed");
+            goto bail;
+        }
+        else if (ret == 0) {
+            // timeout
+            // TSK_DEBUG_INFO("STUN request timedout");
+            goto check_nomination; //!\ continue == possible endless loop
+        }
+        else if (ret > 0) {
+            // there is data to read
+            for (k = 0; k < fds_count; ++k) {
+                tnet_fd_t fd = fds[k];
+                unsigned int len = 0;
+                tsk_size_t read = 0;
+                
+                if (!FD_ISSET(fd, &set)) {
+                    continue;
+                }
+                
+                // Check how many bytes are pending
+                if ((ret = tnet_ioctlt(fd, FIONREAD, &len)) < 0) {
+                    continue;
+                }
+                
+                if (len == 0){
+                    // TSK_DEBUG_INFO("tnet_ioctlt() returent zero bytes");
+                    continue;
+                }
+                
+                // Receive pending data
+                if (recvfrom_buff_size < len){
+                    if (!(recvfrom_buff_ptr = tsk_realloc(recvfrom_buff_ptr, len))){
+                        recvfrom_buff_size = 0;
+                        goto bail;
+                    }
+                    recvfrom_buff_size = len;
+                }
+                
+                // receive all messages
+                while (self->is_started && self->is_active && read < len && ret == 0) {
+                    if ((ret = tnet_sockfd_recvfrom(fd, recvfrom_buff_ptr, recvfrom_buff_size, 0, (struct sockaddr *)&remote_addr)) < 0) {
+                        err = tnet_geterrno();
+                        /* "EAGAIN" means no data to read. We must trust "EAGAIN" instead of "read" because pending data could be removed by the system
+                         */
+                        /* "WSAECONNRESET"
+                         The virtual circuit was reset by the remote side executing a hard or abortive close. The application should close the socket as it is no longer usable. On a UDP-datagram socket, this error would indicate that a previous send operation resulted in an ICMP "Port Unreachable" message.
+                         */
+                        if (err == TNET_ERROR_EAGAIN || err == TNET_ERROR_CONNRESET) {
+                            // TODO: remove "fd" from the list if "E_CONNRESET"
+                            len = 0;
+                            continue;
+                        }
+                        
+                        TNET_PRINT_LAST_ERROR("Receiving STUN dgrams failed with errno=%d", err);
+                        goto bail;
+                    }
+                    
+                    read += ret;
+                    
+                    // recv() STUN message (request / response)
+                    ret = tnet_ice_ctx_recv_stun_message(self, recvfrom_buff_ptr, (tsk_size_t)ret, fd, &remote_addr, &role_conflict);
+                    if (ret == 0 && role_conflict) {
+                        // A change in roles will require to recompute pair priorities
+                        restart_conneck = tsk_true;
+                        // do not break the loop -> read/process all pending STUN messages
+                    }
+                }
+            }
+        }
+        
+    check_nomination:
+        // check whether we need to re-start connection checking
+        if (restart_conneck) {
+            goto start_conneck;
+        }
+        
+        check_rtcp = (self->use_rtcp && !self->use_rtcpmux);
+        if (!self->have_nominated_offer) {
+            self->have_nominated_offer = tnet_ice_pairs_have_nominated_offer(self->candidates_pairs, check_rtcp);
+        }
+        if (!self->have_nominated_answer) {
+            self->have_nominated_answer = tnet_ice_pairs_have_nominated_answer(self->candidates_pairs, check_rtcp);
+        }
+        if (self->have_nominated_offer && self->have_nominated_answer) {
+            self->have_nominated_symetric = tnet_ice_pairs_have_nominated_symetric_2(self->candidates_pairs, check_rtcp, &got_hosts);
+            self->have_nominated_symetric &= (got_hosts || ((tries_count++) >= tries_count_min));
+        }
+    } // while (self->is_started...
+    
+    // "ret" could be "<>0" if last function used was "select()", "recvfrom()", "ioctlt()"...this is why we set the value to #0.
+    // if there was an error then, we'll jump to "bail:" and next code is skipped
+    ret = 0;
+    
+bail:
+    // move to the next state depending on the conncheck result
+    if (self->is_started) {
+        if (ret == 0 && self->have_nominated_symetric) {
+            ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_Success);
+        }
+        else {
+            if (time_curr >= time_end) {
+                TSK_DEBUG_ERROR("ConnCheck timedout, have_nominated_symetric=%s, have_nominated_answer=%s, have_nominated_offer=%s",
+                                self->have_nominated_symetric ? "yes" : "false",
+                                self->have_nominated_answer ? "yes" : "false",
+                                self->have_nominated_offer ? "yes" : "false");
+            }
+            ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_Failure);
+        }
+    }
+    
+    TSK_FREE(recvfrom_buff_ptr);
+    
+    self->is_connchecking = tsk_false;
+    
+    return ret;
+}
+
+// ConnChecking -> (Success) -> ConnCheckingCompleted
+static int _tnet_ice_ctx_fsm_ConnChecking_2_ConnCheckingCompleted_X_Success(va_list *app)
+{
+    tnet_ice_ctx_t* self = va_arg(*app, tnet_ice_ctx_t *);
+    const tnet_ice_pair_t *pair_offer, *pair_answer_src, *pair_answer_dest;
+    const tsk_list_item_t *item;
+    const tnet_ice_pair_t *pair;
+    const tnet_ice_candidate_t *candidate;
+    tsk_list_t* sessions = tsk_list_create(); // for lock-free TURN sessions destroying
+    int ret;
+    
+    // When destroying TURN sessions the transport is locked by shutdown()
+    // This function locks "self->candidates_pairs"
+    // TURN callback locks "self->candidates_pairs"
+    // TURN callback locks the transport
+    // => We must not lock the candidates when destroying the TURN session
+    // Test with WES8 if you want to reproduce the issue
+    
+    TSK_OBJECT_SAFE_FREE(self->turn.ss_nominated_rtp);
+    TSK_OBJECT_SAFE_FREE(self->turn.ss_nominated_rtcp);
+    
+    tsk_list_lock(self->candidates_pairs);
+    
+    // take a reference to the negotiated TURN sessions
+    ret = tnet_ice_pairs_get_nominated_symetric_pairs(self->candidates_pairs, TNET_ICE_CANDIDATE_COMPID_RTP, &pair_offer, &pair_answer_src, &pair_answer_dest);
+    if (ret == 0) {
+        if (pair_offer && pair_offer->candidate_offer && pair_offer->candidate_offer->type_e == tnet_ice_cand_type_relay && pair_offer->candidate_offer->turn.ss) {
+            self->turn.ss_nominated_rtp = tsk_object_ref(pair_offer->candidate_offer->turn.ss);
+            self->turn.peer_id_rtp = pair_offer->turn_peer_id;
+            TSK_DEBUG_INFO("ICE: nominated TURN peer id [RTP] = %ld", self->turn.peer_id_rtp);
+        }
+        TSK_DEBUG_INFO("ICE: nominated symetric RTP pairs: offer:%llu, answer-src:%llu, answser-dest:%llu",
+                       pair_offer ? pair_offer->id : 0, pair_answer_src ? pair_answer_src->id : 0, pair_answer_dest ? pair_answer_dest->id : 0);
+    }
+    if (ret == 0 && pair_offer) { ((tnet_ice_pair_t *)pair_offer)->is_nominated = tsk_true; } // "is_nominated" is used do decide whether to include "USE-CANDIDATE" attribute when aggressive mode is disabled
+    
+    ret = tnet_ice_pairs_get_nominated_symetric_pairs(self->candidates_pairs, TNET_ICE_CANDIDATE_COMPID_RTCP, &pair_offer, &pair_answer_src, &pair_answer_dest);
+    if (ret == 0) {
+        if (pair_offer && pair_offer->candidate_offer && pair_offer->candidate_offer->type_e == tnet_ice_cand_type_relay && pair_offer->candidate_offer->turn.ss) {
+            self->turn.ss_nominated_rtcp = tsk_object_ref(pair_offer->candidate_offer->turn.ss);
+            self->turn.peer_id_rtcp = pair_offer->turn_peer_id;
+            TSK_DEBUG_INFO("ICE: nominated TURN peer id [RTCP] = %ld", self->turn.peer_id_rtp);
+        }
+        TSK_DEBUG_INFO("ICE: nominated symetric RTCP(use:%d, mux:%d) pairs: offer:%llu, answer-src:%llu, answser-dest:%llu",
+                       self->use_rtcp ? 1 : 0, self->use_rtcpmux ? 1 : 0,
+                       pair_offer ? pair_offer->id : 0, pair_answer_src ? pair_answer_src->id : 0, pair_answer_dest ? pair_answer_dest->id : 0);
+    }
+    if (ret == 0 && pair_offer) { ((tnet_ice_pair_t *)pair_offer)->is_nominated = tsk_true; } // "is_nominated" is used do decide whether to include "USE-CANDIDATE" attribute when aggressive mode is disabled
+    
+    // collect all useless TURN sessions (pairs)
+    tsk_list_foreach(item, self->candidates_pairs) {
+        if (!(pair = item->data) || !pair->candidate_offer || !pair->candidate_offer->turn.ss) {
+            continue;
+        }
+        if (pair->candidate_offer->turn.ss != self->turn.ss_nominated_rtp && pair->candidate_offer->turn.ss != self->turn.ss_nominated_rtcp) {
+            tsk_list_push_back_data(sessions, (void**)&pair->candidate_offer->turn.ss);
+            TSK_OBJECT_SAFE_FREE(pair->candidate_offer->turn.ss);
+        }
+    }
+    
+    tsk_list_unlock(self->candidates_pairs);
+    
+    // collect all useless TURN sessions (local candidates)
+    tsk_list_lock(self->candidates_local);
+    tsk_list_foreach(item, self->candidates_local) {
+        if (!(candidate = item->data) || !candidate->turn.ss) {
+            continue;
+        }
+        if (candidate->turn.ss != self->turn.ss_nominated_rtp && candidate->turn.ss != self->turn.ss_nominated_rtcp) {
+            tsk_list_push_back_data(sessions, (void**)&candidate->turn.ss);
+            TSK_OBJECT_SAFE_FREE(((tnet_ice_candidate_t*)candidate)->turn.ss);
+        }
+    }
+    tsk_list_unlock(self->candidates_local);
+    
+    // collect all useless TURN sessions (remote candidates)
+    tsk_list_lock(self->candidates_remote);
+    tsk_list_foreach(item, self->candidates_remote) {
+        if (!(candidate = item->data) || !candidate->turn.ss) {
+            continue;
+        }
+        if (candidate->turn.ss != self->turn.ss_nominated_rtp && candidate->turn.ss != self->turn.ss_nominated_rtcp) {
+            tsk_list_push_back_data(sessions, (void**)&candidate->turn.ss);
+            TSK_OBJECT_SAFE_FREE(((tnet_ice_candidate_t*)candidate)->turn.ss);
+        }
+    }
+    tsk_list_unlock(self->candidates_remote);
+    
+    // lock-free destruction
+    TSK_OBJECT_SAFE_FREE(sessions);
+    
+    return _tnet_ice_ctx_signal_async(self, tnet_ice_event_type_conncheck_succeed, "ConnCheck succeed");
+}
+
+// ConnChecking -> (Failure) ->Terminated
+static int _tnet_ice_ctx_fsm_ConnChecking_2_Terminated_X_Failure(va_list *app)
+{
+    tnet_ice_ctx_t* self = va_arg(*app, tnet_ice_ctx_t *);
+    return _tnet_ice_ctx_signal_async(self, tnet_ice_event_type_conncheck_failed, "ConnCheck failed");
+}
+
+// Any (AnyNotStarted) -> Terminated
+static int _tnet_ice_ctx_fsm_Any_2_Terminated_X_AnyNotStarted(va_list *app)
+{
+    return 0;
+}
+
+//++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+//				== STATE MACHINE END ==
+//++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+
+static int _tnet_ice_ctx_fsm_OnTerminated(tnet_ice_ctx_t* self)
+{
+    TSK_DEBUG_INFO("=== ICE CTX SM Terminated ===");
+    
+    if (!self){
+        TSK_DEBUG_ERROR("Invalid parameter.");
+        return -1;
+    }
+    
+    // still started but no longer active
+    self->is_active = tsk_false;
+    
+    return 0;
+}
+
+static tsk_bool_t _tnet_ice_ctx_fsm_cond_NotStarted(tnet_ice_ctx_t* self, const void* _any)
+{
+    return (!self || !self->is_started);
+}
+
+static int _tnet_ice_ctx_restart(tnet_ice_ctx_t* self)
+{
+    int ret = 0;
+    if (!self) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    
+    ret = tsk_fsm_set_current_state(self->fsm, _fsm_state_Started);
+    ret = _tnet_ice_ctx_fsm_act(self, _fsm_action_GatherHostCandidates);
+    
+    self->is_active = (ret == 0);
+    return ret;
+}
+
+static int _tnet_ice_ctx_recv_stun_message_for_pair(tnet_ice_ctx_t* self, const tnet_ice_pair_t* pair, const void* data, tsk_size_t size, tnet_fd_t local_fd, const struct sockaddr_storage* remote_addr, tsk_bool_t *role_conflict)
+{
+    tnet_stun_pkt_t* message;
+    int ret = 0;
+    if (!self || !role_conflict || !data || !size || local_fd < 0 || !remote_addr) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    
+    *role_conflict = tsk_false;
+    
+    if (!TNET_STUN_BUFF_IS_STUN2(((uint8_t*)data), size)) {
+        if (self->rtp_callback) {
+            return self->rtp_callback(self->rtp_callback_data, data, size, local_fd, remote_addr);
+        }
+        TSK_DEBUG_INFO("Not STUN message");
+        return 0;
+    }
+    
+    if (!self->is_active) {
+        TSK_DEBUG_INFO("ICE context not active yet");
+        return 0;
+    }
+    
+    if ((ret = tnet_stun_pkt_read(data, size, &message)) == 0 && message) {
+        if (message->e_type == tnet_stun_pkt_type_binding_request) {
+            tsk_bool_t is_local_conncheck_started;
+            if (self->is_building_pairs) {
+                TSK_DEBUG_INFO("Incoming STUN binding request while building new ICE pairs... wait for %d milliseconds max", kIcePairsBuildingTimeMax);
+                tsk_condwait_timedwait(self->condwait_pairs, kIcePairsBuildingTimeMax);
+                if (self->is_building_pairs) {
+                    TSK_DEBUG_WARN("%d milliseconds ellapsed and still building pairs", kIcePairsBuildingTimeMax);
+                }
+                if (!self->is_active) {
+                    TSK_DEBUG_WARN("ICE context deactivated while waiting for ICE pairs to finish building");
+                    TSK_OBJECT_SAFE_FREE(message);
+                    return 0;
+                }
+            }
+            is_local_conncheck_started = !TSK_LIST_IS_EMPTY(self->candidates_pairs); // if empty means local conncheck haven't started
+            if (!pair && is_local_conncheck_started) {
+                pair = tnet_ice_pairs_find_by_fd_and_addr(self->candidates_pairs, local_fd, remote_addr);
+            }
+            if (!pair && !self->have_nominated_symetric && is_local_conncheck_started){ // pair not found and we're still negotiating
+                // rfc 5245 - 7.1.3.2.1.  Discovering Peer Reflexive Candidates
+                tnet_ice_pair_t* pair_peer = tnet_ice_pair_prflx_create(self->candidates_pairs, local_fd, remote_addr);
+                if (pair_peer) {
+                    pair = pair_peer; // save memory address
+                    tsk_list_push_descending_data(self->candidates_pairs, (void**)&pair_peer);
+                    TSK_OBJECT_SAFE_FREE(pair_peer);
+                }
+            }
+            if (pair) {
+                short resp_code = 0;
+                char* resp_phrase = tsk_null;
+                // authenticate the request
+                tnet_ice_pair_auth_conncheck(pair, message, data, size, &resp_code, &resp_phrase);
+                if (resp_code > 0 && resp_phrase){
+                    if (resp_code >= 200 && resp_code <= 299){
+                        // Before sending the success response check that there are no role conflict
+                        if (self->is_controlling){ // I'm ICE-CONTROLLING
+                            const tnet_stun_attr_vdata_t* stun_att_ice_controlling;
+                            if ((ret = tnet_stun_pkt_attr_find_first(message, tnet_stun_attr_type_ice_controlling, (const tnet_stun_attr_t**)&stun_att_ice_controlling)) == 0 && stun_att_ice_controlling){
+                                TSK_DEBUG_WARN("Role conflicts (SEND)");
+                                if (self->tie_breaker >= *((uint64_t*)stun_att_ice_controlling->p_data_ptr)) {
+                                    resp_code = kStunErrCodeIceConflict;
+                                    tsk_strupdate(&resp_phrase, "Role conflicts");
+                                }
+                                else {
+                                    // switch to "controlled" role
+                                    self->is_controlling = tsk_false;
+                                    *role_conflict = tsk_true;
+                                }
+                            }
+                            else;
+                        }
+                        else { // I'm ICE-CONTROLLED
+                            const tnet_stun_attr_vdata_t* stun_att_ice_controlled;
+                            if ((ret = tnet_stun_pkt_attr_find_first(message, tnet_stun_attr_type_ice_controlled, (const tnet_stun_attr_t**)&stun_att_ice_controlled)) == 0 && stun_att_ice_controlled) {
+                                TSK_DEBUG_WARN("Role conflicts (SEND)");
+                                if (self->tie_breaker >= *((uint64_t*)stun_att_ice_controlled->p_data_ptr)) {
+                                    self->is_controlling = tsk_true;
+                                    *role_conflict = tsk_true;
+                                }
+                                else {
+                                    resp_code = kStunErrCodeIceConflict;
+                                    tsk_strupdate(&resp_phrase, "Role conflicts");
+                                }
+                            }
+                        }
+                    }
+                    ret = tnet_ice_pair_send_response((tnet_ice_pair_t *)pair, message, resp_code, resp_phrase, remote_addr);
+                    // "keepalive": also send STUN-BINDING if we receive one in the nominated pair and conneck is finished
+                    //!\ IMPORTANT: chrome requires this
+                    //!\ We also need to continue sending connection checks as we don't really know if the remote party has finished checking
+                    if ((self->is_ice_jingle || pair->is_nominated) && self->have_nominated_symetric) {
+                        ret = tnet_ice_pair_send_conncheck((tnet_ice_pair_t *)pair); // "keepalive"
+                    }
+                }
+                TSK_FREE(resp_phrase);
+            }
+            else { // if(pair == null)
+                if (!is_local_conncheck_started) {
+                    TSK_DEBUG_INFO("ICE local conncheck haven't started yet");
+                }
+                else {
+                    TSK_DEBUG_ERROR("Cannot find ICE pair with local fd = %d", local_fd);
+                }
+            }
+        }
+        else if (TNET_STUN_PKT_IS_RESP(message)) {
+            if (pair || (pair = tnet_ice_pairs_find_by_response(self->candidates_pairs, message))) {
+                ret = tnet_ice_pair_recv_response(((tnet_ice_pair_t*)pair), message, self->is_connchecking);
+#if 0
+                if (TNET_STUN_PKT_RESP_IS_ERROR(message)) {
+                    uint16_t u_code;
+                    if ((ret = tnet_stun_pkt_get_errorcode(message, &u_code)) == 0 && u_code == kStunErrCodeIceConflict) {
+                        // If this code is called this means that we have lower tie-breaker and we must toggle our role
+                        TSK_DEBUG_WARN("Role conflicts (RECV)");
+                        self->is_controlling = !self->is_controlling;
+                        *role_conflict = tsk_true;
+                    }
+                }
+#endif
+            }
+        }
+    }
+    TSK_OBJECT_SAFE_FREE(message);
+    
+    return ret;
+}
+
+static int _tnet_ice_ctx_send_turn_raw(struct tnet_ice_ctx_s* self, struct tnet_turn_session_s* turn_ss, tnet_turn_peer_id_t turn_peer_id, const void* data, tsk_size_t size)
+{
+    if (!self || !turn_ss || !data || !size){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    // (self);
+    return tnet_turn_session_send_data(turn_ss, turn_peer_id, data, (uint16_t)size);
+}
+
+
+// build pairs as per RFC 5245 section "5.7.1. Forming Candidate Pairs"
+static int _tnet_ice_ctx_build_pairs(struct tnet_ice_ctx_s* self, tnet_ice_candidates_L_t* local_candidates, tnet_ice_candidates_L_t* remote_candidates, tnet_ice_pairs_L_t* result_pairs, tsk_bool_t is_controlling, uint64_t tie_breaker, tsk_bool_t is_ice_jingle, tsk_bool_t is_rtcpmuxed)
+{
+    const tsk_list_item_t *item_local, *item_remote;
+    const tnet_ice_candidate_t *cand_local, *cand_remote;
+    tnet_ice_pair_t *pair;
+    enum tnet_turn_transport_e e_req_transport;
+    tnet_family_t addr_family_local, addr_family_remote;
+    
+    if (!self || TSK_LIST_IS_EMPTY(local_candidates) || TSK_LIST_IS_EMPTY(remote_candidates) || !result_pairs) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    
+    self->is_building_pairs = tsk_true;
+    TSK_DEBUG_INFO("ICE: begin building pairs(is_rtcpmuxed=%d)", is_rtcpmuxed);
+    
+    tsk_list_clear_items(result_pairs);
+    
+    tsk_list_lock(local_candidates);
+    tsk_list_lock(remote_candidates);
+    tsk_list_lock(result_pairs);
+    
+    tsk_list_foreach(item_local, local_candidates) {
+        if (!(cand_local = item_local->data)) {
+            continue;
+        }
+        if (is_rtcpmuxed && cand_local->comp_id == TNET_ICE_CANDIDATE_COMPID_RTCP) {
+            continue;
+        }
+#if 0 // TURN:FORCE
+        if (cand_local->type_e != tnet_ice_cand_type_relay) {
+            continue;
+        }
+#endif
+        
+        tsk_list_foreach(item_remote, remote_candidates) {
+            if (!(cand_remote = item_remote->data)) {
+                continue;
+            }
+            // Hack for Chrome bug (candidate with port=zero) to avoid printing errors.
+            if (cand_remote->port == 0) {
+                TSK_DEBUG_INFO("Skipping remote ICE candidate with port = 0");
+                continue;
+            }
+            
+            // CompIds(1=RTP, 2=RTCP) must match
+            if ((cand_remote->comp_id != cand_local->comp_id)){
+                continue;
+            }
+            // IP versions must match. Cannot use IPv4 socket to send/recv to IPv6 address.
+            if (cand_local->socket) {
+                addr_family_local = TNET_SOCKET_TYPE_IS_IPV4(cand_local->socket->type) ? AF_INET : AF_INET6;
+                addr_family_remote = tnet_get_family(cand_remote->connection_addr, cand_remote->port);
+                if (addr_family_local != addr_family_remote) {
+                    TSK_DEBUG_INFO("Address family mismatch:%d<->%d", addr_family_local, addr_family_remote);
+                    continue;
+                }
+            }
+            if (cand_local->turn.ss) {
+                if (tnet_turn_session_get_req_transport(cand_local->turn.ss, &e_req_transport) != 0) {
+                    continue;
+                }
+                if (e_req_transport == tnet_turn_transport_udp && !TNET_SOCKET_TYPE_IS_DGRAM(cand_remote->transport_e)) {
+                    continue;
+                }
+                if (e_req_transport == tnet_turn_transport_tcp && !TNET_SOCKET_TYPE_IS_STREAM(cand_remote->transport_e)) {
+                    continue;
+                }
+            }
+            else {
+                if (cand_remote->transport_e != cand_local->transport_e) {
+                    continue;
+                }
+            }
+            
+            if ((pair = tnet_ice_pair_create(cand_local, cand_remote, is_controlling, tie_breaker, is_ice_jingle))) {
+                TSK_DEBUG_INFO("ICE Pair(%llu, %llu): [%s %u %u %s %d] -> [%s %u %u %s %d]",
+                               pair->id,
+                               pair->priority,
+                               
+                               cand_local->foundation,
+                               cand_local->priority,
+                               cand_local->comp_id,
+                               cand_local->connection_addr,
+                               cand_local->port,
+                               
+                               cand_remote->foundation,
+                               cand_remote->priority,
+                               cand_remote->comp_id,
+                               cand_remote->connection_addr,
+                               cand_remote->port);
+                tsk_list_push_descending_data(result_pairs, (void**)&pair);
+            }
+        }
+    }
+#if 0
+    tsk_list_foreach(item_local, result_pairs) {
+        if (!(pair = item_local->data)) {
+            continue;
+        }
+        
+        TSK_DEBUG_INFO("ICE Pair(%llu, %llu): [%s %u %s %d] -> [%s %u %s %d]",
+                       pair->id,
+                       pair->priority,
+                       
+                       pair->candidate_offer->foundation,
+                       pair->candidate_offer->comp_id,
+                       pair->candidate_offer->connection_addr,
+                       pair->candidate_offer->port,
+                       
+                       pair->candidate_answer->foundation,
+                       pair->candidate_answer->comp_id,
+                       pair->candidate_answer->connection_addr,
+                       pair->candidate_answer->port);
+    }
+#endif
+    
+    tsk_list_unlock(local_candidates);
+    tsk_list_unlock(remote_candidates);
+    tsk_list_unlock(result_pairs);
+    
+    self->is_building_pairs = tsk_false;
+    tsk_condwait_broadcast(self->condwait_pairs);
+    TSK_DEBUG_INFO("ICE: end building pairs");
+    
+    return 0;
+}
+
+
+static int _tnet_ice_ctx_fsm_act(tnet_ice_ctx_t* self, tsk_fsm_action_id action_id)
+{
+    tnet_ice_action_t *action = tsk_null;
+    tnet_ice_event_t* e = tsk_null;
+    static const char* phrase = "$action$";
+    int ret = 0;
+    
+    if (!self || !self->fsm){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    if (!(action = tnet_ice_action_create(action_id))){
+        TSK_DEBUG_ERROR("Failed to create action");
+        return -2;
+    }
+    
+    if (self->is_sync_mode) {
+        ret = tsk_fsm_act(self->fsm, action->id, self, action, self, action);
+    }
+    else {
+        if ((e = tnet_ice_event_create(self, tnet_ice_event_type_action, phrase, self->userdata))){
+            tnet_ice_event_set_action(e, action);
+            TSK_RUNNABLE_ENQUEUE_OBJECT_SAFE(TSK_RUNNABLE(self), e);
+            goto bail;
+        }
+        else{
+            TSK_DEBUG_ERROR("Failed to create ICE event");
+            ret = -2;
+            goto bail;
+        }
+    }
+    
+bail:
+    TSK_OBJECT_SAFE_FREE(e);
+    TSK_OBJECT_SAFE_FREE(action);
+    return ret;
+}
+
+static int _tnet_ice_ctx_signal_async(tnet_ice_ctx_t* self, tnet_ice_event_type_t type, const char* phrase)
+{
+    tnet_ice_event_t* e;
+    if (!self){
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    
+    if (self->is_silent_mode && type != tnet_ice_event_type_action) { // silent mode ON and not action to move the FSM
+        TSK_DEBUG_INFO("ICE silent mode ON...to not notify '%d:%s'", type, phrase);
+        return 0;
+    }
+    
+    if ((e = tnet_ice_event_create(self, type, phrase, self->userdata))){
+        TSK_RUNNABLE_ENQUEUE_OBJECT_SAFE(TSK_RUNNABLE(self), e);
+        return 0;
+    }
+    else{
+        TSK_DEBUG_ERROR("Failed to create ICE event");
+        return -2;
+    }
+}
+
+static int _tnet_ice_ctx_turn_callback(const struct tnet_turn_session_event_xs *e)
+{
+    tnet_ice_ctx_t *ctx = tsk_object_ref(TSK_OBJECT(e->pc_usr_data));
+    struct tnet_turn_session_s* session = tsk_object_ref(TSK_OBJECT(e->pc_session));
+    int ret = 0;
+    
+    if (!ctx) {
+        // the ICE context is being destroyed but TURN session not freed yet
+        goto bail;
+    }
+    
+    switch (e->e_type) {
+        case tnet_turn_session_event_type_alloc_ok:
+        case tnet_turn_session_event_type_refresh_ok:
+        case tnet_turn_session_event_type_chanbind_ok:
+        case tnet_turn_session_event_type_connect_ok:
+        default:
+        {
+            break;
+        }
+            
+        case tnet_turn_session_event_type_alloc_nok:
+        case tnet_turn_session_event_type_refresh_nok:
+        case tnet_turn_session_event_type_perm_nok:
+        case tnet_turn_session_event_type_chanbind_nok:
+        case tnet_turn_session_event_type_connect_nok:
+        {
+            // Do not raise error event if no nominated candidate because
+            // TURN error could be raised by the session when we're in "conncheck" state and this is a normal case.
+            if (ctx->is_active && ctx->is_started && ctx->turn.ss_nominated_rtp && ctx->turn.peer_id_rtp == e->u_peer_id) {
+                TSK_DEBUG_ERROR("TURN connection broken (peer-id=%ld)", e->u_peer_id);
+                if ((ret = _tnet_ice_ctx_signal_async(ctx, tnet_ice_event_type_turn_connection_broken, "TURN connection is broken"))) {
+                    goto bail;
+                }
+            }
+            break;
+        }
+            
+        case tnet_turn_session_event_type_perm_ok:
+        {
+            enum tnet_turn_transport_e e_req_transport;
+            if ((ret = tnet_turn_session_get_req_transport(session, &e_req_transport))) {
+                goto bail;
+            }
+            
+            if (e_req_transport == tnet_turn_transport_tcp) {
+                // TCP-Connect: rfc6062 - 4.3.  Initiating a Connection
+                if ((ret = tnet_turn_session_connect(session, e->u_peer_id))) {
+                    goto bail;
+                }
+            }
+            else {
+                // Bind a channel (not required). If succeed, will be used to save bandwidth usage.
+                // TODO: should be done only if first "get_state(chanbind)==none". Not an issue, if it already exists then, will be refreshed.
+                if ((ret = tnet_turn_session_chanbind(session, e->u_peer_id))) {
+                    goto bail;
+                }
+            }
+            break;
+        }
+            
+        case tnet_turn_session_event_type_recv_data:
+        {
+            tsk_bool_t role_conflict;
+            tnet_ice_pair_t* pair = tsk_null;
+            if (e->u_peer_id != kTurnPeerIdInvalid) {
+                const tsk_list_item_t *item;
+                tsk_list_lock(ctx->candidates_pairs);
+                tsk_list_foreach(item, ctx->candidates_pairs) {
+                    if (((const tnet_ice_pair_t*)item->data)->turn_peer_id == e->u_peer_id) {
+                        pair = tsk_object_ref((void*)item->data);
+                        break;
+                    }
+                }
+                tsk_list_unlock(ctx->candidates_pairs);
+            }
+            
+            ret = _tnet_ice_ctx_recv_stun_message_for_pair(
+                                                           ctx,
+                                                           pair,
+                                                           e->data.pc_data_ptr, e->data.u_data_size,
+                                                           e->pc_enet ? e->pc_enet->local_fd : TNET_INVALID_FD,
+                                                           e->pc_enet ? &e->pc_enet->remote_addr : tsk_null,
+                                                           &role_conflict);
+            TSK_OBJECT_SAFE_FREE(pair);
+            if (ret) {
+                goto bail;
+            }
+            
+            // rebuild candidates if role conflict
+            if (role_conflict) {
+                tsk_list_lock(ctx->candidates_pairs);
+                tsk_list_clear_items(ctx->candidates_pairs);
+                tsk_list_unlock(ctx->candidates_pairs);
+                
+                TSK_OBJECT_SAFE_FREE(ctx->turn.ss_nominated_rtp);
+                TSK_OBJECT_SAFE_FREE(ctx->turn.ss_nominated_rtcp);
+                
+                if ((ret = _tnet_ice_ctx_build_pairs(ctx, ctx->candidates_local, ctx->candidates_remote, ctx->candidates_pairs, ctx->is_controlling, ctx->tie_breaker, ctx->is_ice_jingle, ctx->use_rtcpmux))) {
+                    TSK_DEBUG_ERROR("_tnet_ice_ctx_build_pairs() failed");
+                    goto bail;
+                }
+            }
+            
+            break;
+        }
+    }
+    
+    // alert() waiting threads
+    if ((ret = tsk_condwait_broadcast(ctx->turn.condwait))) {
+        goto bail;
+    }
+    
+bail:
+    tsk_object_unref(ctx);
+    tsk_object_unref(session);
+    return ret;
+}
+
+static void* TSK_STDCALL _tnet_ice_ctx_run(void* self)
+{
+    // No need to take ref(ctx) because this thread will be stopped by the dtor() before memory free.
+    tsk_list_item_t *curr;
+    tnet_ice_ctx_t *ctx = (tnet_ice_ctx_t *)(self);
+    tnet_ice_event_t *e;
+    
+    TSK_DEBUG_INFO("ICE CTX::run -- START");
+    
+    TSK_RUNNABLE_RUN_BEGIN(ctx);
+    
+    // must because "ctx->callback(e);" could call a function trying to free "ctx"
+    // do not move before "TSK_RUNNABLE_RUN_BEGIN(ctx)", otherwise it'll be required to stop the "runnable" to have "ctx->refCount==0"
+    ctx = tsk_object_ref(ctx);
+    
+    if (ctx->is_started && (curr = TSK_RUNNABLE_POP_FIRST(ctx))) {
+        e = (tnet_ice_event_t*)curr->data;
+        switch (e->type) {
+            case tnet_ice_event_type_action:
+            {
+                if (e->action) {
+                    tsk_fsm_act(ctx->fsm, e->action->id, ctx, e->action, ctx, e->action);
+                }
+                break;
+            }
+            default:
+            {
+                if (ctx->callback){
+                    ctx->callback(e);
+                }
+                break;
+            }
+        }
+        tsk_object_unref(curr);
+    }
+    
+    if (!(ctx = tsk_object_unref(ctx))) {
+        goto exit;
+    }
+    
+    TSK_RUNNABLE_RUN_END(ctx);
+    
+exit:
+    if (ctx) {
+        tsk_list_clear_items(ctx->candidates_local);
+        tsk_list_clear_items(ctx->candidates_remote);
+        tsk_list_lock(ctx->candidates_pairs); // must
+        tsk_list_clear_items(ctx->candidates_pairs);
+        tsk_list_unlock(ctx->candidates_pairs);
+    }
+    
+    TSK_DEBUG_INFO("ICE CTX::run -- STOP");
+    
+    return 0;
+}
+
+static int _tnet_ice_ctx_servers_clear(struct tnet_ice_ctx_s* self)
+{
+    if (!self) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    tsk_list_lock(self->servers);
+    tsk_list_clear_items(self->servers);
+    tsk_list_unlock(self->servers);
+    return 0;
+}
+
+static int _tnet_ice_ctx_server_add(struct tnet_ice_ctx_s* self, enum tnet_ice_server_proto_e e_proto,
+                                    enum tnet_socket_type_e e_transport,
+                                    const char* str_server_addr, uint16_t u_server_port,
+                                    const char* str_software,
+                                    const char* str_username, const char* str_password)
+{
+    struct tnet_ice_server_s* ice_server;
+    int ret = -1;
+    if (!self || !e_proto || !str_server_addr || !u_server_port) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    
+    // TURN requires credentials
+    if ((e_proto & tnet_ice_server_proto_turn) == tnet_ice_server_proto_turn && (tsk_strnullORempty(str_username) || tsk_strnullORempty(str_password))) {
+        /* rfc5766 - 4.  General Behavior
+         The server MUST demand that all requests from the client
+         be authenticated using this mechanism, or that a equally strong or
+         stronger mechanism for client authentication is used.*/
+        TSK_DEBUG_ERROR("TURN requires credentials");
+        return -1;
+    }
+    // Create and add the ICE server
+    tsk_list_lock(self->servers);
+    if (_tnet_ice_ctx_server_exists(self, e_proto, e_transport, str_server_addr, u_server_port)) {
+        TSK_DEBUG_WARN("ICE server (proto=%d, transport=%d, addr=%s, port=%hu) already exists", e_proto, e_transport, str_server_addr, u_server_port);
+        ret = 0; // Not an error
+        goto bail;
+    }
+    if (!(ice_server = tnet_ice_server_create(e_proto, e_transport, str_server_addr, u_server_port, str_software, str_username, str_password))) {
+        TSK_DEBUG_ERROR("Failed to create ICE server(proto=%d, transport=%d, addr=%s, port=%hu)", e_proto, e_transport, str_server_addr, u_server_port);
+        goto bail;
+    }
+    tsk_list_push_back_data(self->servers, (void**)&ice_server);
+    TSK_OBJECT_SAFE_FREE(ice_server);
+    
+    ret = 0;
+bail:
+    tsk_list_unlock(self->servers);
+    return ret;
+}
+
+static int _tnet_ice_ctx_server_remove(struct tnet_ice_ctx_s* self, enum tnet_ice_server_proto_e e_proto, enum tnet_socket_type_e e_transport, const char* str_server_addr, uint16_t u_server_port)
+{
+    const struct tnet_ice_server_s* _pc_ice_srv;
+    const tsk_list_item_t *pc_item;
+    if (!self) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return -1;
+    }
+    tsk_list_lock(self->servers);
+    tsk_list_foreach(pc_item, self->servers) {
+        if ((_pc_ice_srv = pc_item->data)) {
+            if (_pc_ice_srv->e_proto == e_proto && _pc_ice_srv->e_transport == e_transport && _pc_ice_srv->u_server_port == u_server_port && tsk_striequals(_pc_ice_srv->str_server_addr, str_server_addr)) {
+                tsk_list_remove_item(self->servers, (tsk_list_item_t *)pc_item);
+                break;
+            }
+        }
+    }
+    tsk_list_unlock(self->servers);
+    return 0;
+}
+
+static const struct tnet_ice_server_s* _tnet_ice_ctx_server_find(struct tnet_ice_ctx_s* self, enum tnet_ice_server_proto_e e_proto, enum tnet_socket_type_e e_transport, const char* str_server_addr, uint16_t u_server_port)
+{
+    const struct tnet_ice_server_s* pc_ice_srv = tsk_null;
+    const struct tnet_ice_server_s* _pc_ice_srv;
+    const tsk_list_item_t *pc_item;
+    if (!self) {
+        TSK_DEBUG_ERROR("Invalid parameter");
+        return tsk_null;
+    }
+    tsk_list_lock(self->servers);
+    tsk_list_foreach(pc_item, self->servers) {
+        if ((_pc_ice_srv = pc_item->data)) {
+            if (_pc_ice_srv->e_proto == e_proto && _pc_ice_srv->e_transport == e_transport && _pc_ice_srv->u_server_port == u_server_port && tsk_striequals(_pc_ice_srv->str_server_addr, str_server_addr)) {
+                pc_ice_srv = _pc_ice_srv;
+                break;
+            }
+        }
+    }
+    tsk_list_unlock(self->servers);
+    return pc_ice_srv;
+}
+
+static tsk_bool_t _tnet_ice_ctx_server_exists(struct tnet_ice_ctx_s* self, enum tnet_ice_server_proto_e e_proto, enum tnet_socket_type_e e_transport, const char* str_server_addr, uint16_t u_server_port)
+{
+    return _tnet_ice_ctx_server_find(self, e_proto, e_transport, str_server_addr, u_server_port) ? tsk_true : tsk_false;
+}
+
+static tsk_size_t _tnet_ice_ctx_servers_count_by_proto(struct tnet_ice_ctx_s* self, enum tnet_ice_server_proto_e e_proto)
+{
+    tsk_size_t count = 0;
+    if (self) {
+        const struct tnet_ice_server_s* _pc_ice_srv;
+        const tsk_list_item_t *pc_item;
+        tsk_list_lock(self->servers);
+        tsk_list_foreach(pc_item, self->servers) {
+            if ((_pc_ice_srv = pc_item->data) && (_pc_ice_srv->e_proto & e_proto) == e_proto) {
+                ++count;
+            }
+        }
+        tsk_list_unlock(self->servers);
+    }
+    return count;
+}
+
+// Up to the caller to free the returned list
+static tnet_ice_servers_L_t* _tnet_ice_ctx_servers_copy(struct tnet_ice_ctx_s* self, enum tnet_ice_server_proto_e e_proto)
+{
+    tnet_ice_servers_L_t* copy = tsk_list_create();
+    if (copy) {
+        const struct tnet_ice_server_s* _pc_ice_srv;
+        const tsk_list_item_t *pc_item;
+        tsk_list_lock(self->servers);
+        tsk_list_foreach(pc_item, self->servers) {
+            if ((_pc_ice_srv = pc_item->data) && (_pc_ice_srv->e_proto & e_proto) == e_proto) {
+                tnet_ice_server_t* srv = (tnet_ice_server_t*)tsk_object_ref(pc_item->data);
+                tsk_list_push_back_data(copy, (void**)&srv);
+            }
+        }
+        tsk_list_unlock(self->servers);
+    }
+    return copy;
+}