path: root/tinyNET/src/ice/tnet_ice_candidate.c

/*
 * 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.
 *
 */
#include "tnet_ice_candidate.h"
#include "tnet_ice_utils.h"
#include "tnet_utils.h"
#include "turn/tnet_turn_session.h"

#include "tsk_md5.h"
#include "tsk_memory.h"
#include "tsk_list.h"
#include "tsk_string.h"
#include "tsk_debug.h"

#include <stdlib.h>
#include <string.h>
#include <ctype.h>

static int _tnet_ice_candidate_tostring(
                                        uint8_t* foundation,
                                        uint32_t comp_id,
                                        const char* transport_str,
                                        uint32_t priority,
                                        const char* connection_addr,
                                        tnet_port_t port,
                                        const char* cand_type_str,
                                        const tsk_params_L_t *extension_att_list,
                                        char** output);
static const char* _tnet_ice_candidate_get_foundation(tnet_ice_cand_type_t type);
static tnet_stun_pkt_t * _tnet_ice_candidate_stun_create_bind_request(tnet_ice_candidate_t* self, const char* username, const char* password);
static tsk_bool_t _tnet_ice_candidate_stun_transac_id_equals(const tnet_stun_transac_id_t id1, const tnet_stun_transac_id_t id2);
static const char* _tnet_ice_candidate_get_transport_str(tnet_socket_type_t transport_e);
static tnet_socket_type_t _tnet_ice_candidate_get_transport_type(tsk_bool_t ipv6, const char* transport_str);
static const char* _tnet_ice_candidate_get_candtype_str(tnet_ice_cand_type_t candtype_e);
static tnet_ice_cand_type_t _tnet_ice_candtype_get_transport_type(const char* candtype_str);

static tsk_object_t* tnet_ice_candidate_ctor(tsk_object_t * self, va_list * app)
{
    tnet_ice_candidate_t *candidate = self;
    if (candidate){
        candidate->extension_att_list = tsk_list_create();
    }
    return self;
}

static tsk_object_t* tnet_ice_candidate_dtor(tsk_object_t * self)
{
    tnet_ice_candidate_t *candidate = self;
    if (candidate){
        TSK_SAFE_FREE(candidate->transport_str);
        TSK_SAFE_FREE(candidate->cand_type_str);
        TSK_OBJECT_SAFE_FREE(candidate->extension_att_list);
        TSK_OBJECT_SAFE_FREE(candidate->socket);
        
        
        TSK_SAFE_FREE(candidate->stun.nonce);
        TSK_SAFE_FREE(candidate->stun.realm);
        TSK_SAFE_FREE(candidate->stun.srflx_addr);
        
        TSK_SAFE_FREE(candidate->turn.relay_addr);
        TSK_OBJECT_SAFE_FREE(candidate->turn.ss);
        
        TSK_SAFE_FREE(candidate->ufrag);
        TSK_SAFE_FREE(candidate->pwd);
        
        TSK_SAFE_FREE(candidate->tostring);
    }
    return self;
}

static int tnet_ice_candidate_cmp(const tsk_object_t *_s1, const tsk_object_t *_s2)
{
    const tnet_ice_candidate_t *c1 = _s1;
    const tnet_ice_candidate_t *c2 = _s2;
    
    if (c1 && c2){
        return (int)(c1->priority - c2->priority);
    }
    else if (!c1 && !c2) return 0;
    else return -1;
}

static const tsk_object_def_t tnet_ice_candidate_def_s =
{
    sizeof(tnet_ice_candidate_t),
    tnet_ice_candidate_ctor,
    tnet_ice_candidate_dtor,
    tnet_ice_candidate_cmp,
};

tnet_ice_candidate_t* tnet_ice_candidate_create(tnet_ice_cand_type_t type_e, tnet_socket_t* socket, tsk_bool_t is_ice_jingle, tsk_bool_t is_rtp, tsk_bool_t is_video, const char* ufrag, const char* pwd, const char *foundation)
{
    tnet_ice_candidate_t* candidate;
    
    if (!(candidate = tsk_object_new(&tnet_ice_candidate_def_s))){
        TSK_DEBUG_ERROR("Failed to create candidate");
        return tsk_null;
    }
    
    candidate->type_e = type_e;
    candidate->socket = tsk_object_ref(socket);
    candidate->local_pref = 0xFFFF;
    candidate->is_ice_jingle = is_ice_jingle;
    candidate->is_rtp = is_rtp;
    candidate->is_video = is_video;
    candidate->comp_id = is_rtp ? TNET_ICE_CANDIDATE_COMPID_RTP : TNET_ICE_CANDIDATE_COMPID_RTCP;
    if (foundation){
        memcpy(candidate->foundation, foundation, TSK_MIN(tsk_strlen(foundation), TNET_ICE_CANDIDATE_FOUND_SIZE_PREF));
    }
    else{
        tnet_ice_utils_compute_foundation((char*)candidate->foundation, TSK_MIN(sizeof(candidate->foundation), TNET_ICE_CANDIDATE_FOUND_SIZE_PREF));
    }
    candidate->priority = tnet_ice_utils_get_priority(candidate->type_e, candidate->local_pref, candidate->is_rtp);
    if (candidate->socket){
        memcpy(candidate->connection_addr, candidate->socket->ip, sizeof(candidate->socket->ip));
        candidate->port = candidate->socket->port;
        candidate->transport_e = socket->type;
    }
    tnet_ice_candidate_set_credential(candidate, ufrag, pwd);
    
    return candidate;
}

// @param str e.g. "1 1 udp 1 192.168.196.1 57806 typ host name video_rtcp network_name {0C0137CC-DB78-46B6-9B6C-7E097FFA79FE} username StFEVThMK2DHThkv password qkhKUDr4WqKRwZTo generation 0"
tnet_ice_candidate_t* tnet_ice_candidate_parse(const char* str)
{
    char *v, *copy, *saveptr;
    int32_t k;
    tnet_ice_candidate_t* candidate;
    
    if (tsk_strnullORempty(str)){
        TSK_DEBUG_ERROR("Invalid parameter");
        return tsk_null;
    }
    
    if (!(candidate = tsk_object_new(&tnet_ice_candidate_def_s))){
        TSK_DEBUG_ERROR("Failed to create candidate");
        return tsk_null;
    }
    
    k = 0;
    copy = tsk_strdup(str);
    v = tsk_strtok_r(copy, " ", &saveptr);
    
    while (v){
        switch (k){
            case 0:
            {
                memcpy(candidate->foundation, v, TSK_MIN(tsk_strlen(v), sizeof(candidate->foundation)));
                break;
            }
            case 1:
            {
                candidate->comp_id = atoi(v);
                break;
            }
            case 2:
            {
                candidate->transport_str = tsk_strdup(v);
                break;
            }
            case 3:
            {
                candidate->priority = atoi(v);
                break;
            }
            case 4:
            {
                memcpy(candidate->connection_addr, v, TSK_MIN(tsk_strlen(v), sizeof(candidate->connection_addr)));
                break;
            }
            case 5:
            {
                tnet_family_t family;
                candidate->port = atoi(v);
                family = tnet_get_family(candidate->connection_addr, candidate->port);
                candidate->transport_e = _tnet_ice_candidate_get_transport_type((family == AF_INET6), candidate->transport_str);
                break;
            }
            case 6:
            {
                v = tsk_strtok_r(tsk_null, " ", &saveptr);
                tsk_strupdate(&candidate->cand_type_str, v);
                candidate->type_e = _tnet_ice_candtype_get_transport_type(v);
                break;
            }
            default:
            {
                const char* name = v;
                const char* value = (v = tsk_strtok_r(tsk_null, " ", &saveptr));
                tsk_param_t* param = tsk_param_create(name, value);
                if (param){
                    tsk_list_push_back_data(candidate->extension_att_list, (void**)&param);
                }
                break;
            }
        }
        
        ++k;
        v = tsk_strtok_r(tsk_null, " ", &saveptr);
    }
    
    if (k < 6){
        TSK_DEBUG_ERROR("Failed to parse: %s", str);
        TSK_OBJECT_SAFE_FREE(candidate);
    }
    TSK_FREE(copy);
    
    return candidate;
}

int tnet_ice_candidate_set_credential(tnet_ice_candidate_t* self, const char* ufrag, const char* pwd)
{
    if (!self){
        TSK_DEBUG_ERROR("Invalid parameter");
        return -1;
    }
    
    tsk_strupdate(&self->ufrag, ufrag);
    tsk_strupdate(&self->pwd, pwd);
    
    return 0;
}

int tnet_ice_candidate_set_rflx_addr(tnet_ice_candidate_t* self, const char* addr, tnet_port_t port)
{
    if (!self || !addr || !port){
        TSK_DEBUG_ERROR("Invalid argument");
        return -1;
    }
    memset(self->connection_addr, 0, sizeof(self->connection_addr));
    memcpy(self->connection_addr, addr, TSK_MIN(tsk_strlen(addr), sizeof(self->connection_addr)));
    self->port = port;
    return 0;
}

const char* tnet_ice_candidate_get_att_value(const tnet_ice_candidate_t* self, const char* att_name)
{
    if (!self || !att_name){
        TSK_DEBUG_ERROR("Invalid parameter");
        return tsk_null;
    }
    return tsk_params_get_param_value(self->extension_att_list, att_name);
}

int tnet_ice_candidate_set_local_pref(tnet_ice_candidate_t* self, uint16_t local_pref)
{
    if (!self){
        TSK_DEBUG_ERROR("Invalid parameter");
        return -1;
    }
    self->local_pref = local_pref;
    self->priority = tnet_ice_utils_get_priority(self->type_e, self->local_pref, self->is_rtp);
    return 0;
}

const char* tnet_ice_candidate_tostring(tnet_ice_candidate_t* self)
{
    const char* _transport_str;
    char __str[255]; // always allocated: bad idea :(
    
    if (!self){
        TSK_DEBUG_ERROR("Invalid argument");
        return tsk_null;
    }
    
    if (self->type_e == tnet_ice_cand_type_relay && self->turn.ss) {
        enum tnet_turn_transport_e e_req_transport = tnet_turn_transport_udp;
        tnet_turn_session_get_req_transport(self->turn.ss, &e_req_transport);
        _transport_str = (e_req_transport == tnet_turn_transport_tcp) ? "tcp" : "udp";
    }
    else {
        _transport_str = self->transport_str ? self->transport_str : _tnet_ice_candidate_get_transport_str(self->transport_e);
        if (self->is_ice_jingle){
            tsk_size_t i, s = tsk_strlen(_transport_str);
            memset(__str, 0, sizeof(__str));
            for (i = 0; i < s && i < sizeof(__str) / sizeof(__str[0]); ++i){
                __str[i] = tolower(_transport_str[i]);
            }
            _transport_str = &__str[0];
        }
    }
    
    _tnet_ice_candidate_tostring(
                                 self->foundation,
                                 self->comp_id,
                                 _transport_str,
                                 self->priority,
                                 (tsk_strnullORempty(self->connection_addr) && self->socket) ? self->socket->ip : self->connection_addr,
                                 (self->port <= 0 && self->socket) ? self->socket->port : self->port,
                                 self->cand_type_str ? self->cand_type_str : _tnet_ice_candidate_get_candtype_str(self->type_e),
                                 self->extension_att_list,
                                 &self->tostring);
    
    /* <rel-addr> and <rel-port>:  convey transport addresses related to the
     candidate, useful for diagnostics and other purposes. <rel-addr>
     and <rel-port> MUST be present for server reflexive, peer
     reflexive, and relayed candidates. */
    switch (self->type_e){
        case tnet_ice_cand_type_srflx:
        case tnet_ice_cand_type_prflx:
        case tnet_ice_cand_type_relay:
        {
            if (self->socket){ // when called from the browser(IE, Safari, Opera or Firefox) webrtc4all
                tsk_strcat_2(&self->tostring, " raddr %s rport %d", self->socket->ip, self->socket->port);
            }
            break;
        }
        default:
        {
            break;
        }
    }
    
    // To ease debugging
    if (self->socket) {
        tsk_strcat_2(&self->tostring, " tr %s", _tnet_ice_candidate_get_transport_str(self->socket->type));
        if (self->type_e == tnet_ice_cand_type_relay && self->turn.ss) {
            tnet_socket_t* turn_sock = tsk_null;
            if (tnet_turn_session_get_socket_local(self->turn.ss, &turn_sock) == 0 && turn_sock) {
                tsk_strcat_2(&self->tostring, " fd %d", turn_sock->fd);
            }
            TSK_OBJECT_SAFE_FREE(turn_sock);
        }
        else {
            tsk_strcat_2(&self->tostring, " fd %d", self->socket->fd);
        }
    }
    
    // WebRTC (Chrome) specific
    if (self->is_ice_jingle) {
        if (!tsk_params_have_param(self->extension_att_list, "name")){
            tsk_strcat_2(&self->tostring, " name %s", self->is_rtp ? (self->is_video ? "video_rtp" : "rtp") : (self->is_video ? "video_rtcp" : "rtcp"));
        }
        if (!tsk_params_have_param(self->extension_att_list, "username")){
            tsk_strcat_2(&self->tostring, " username %s", self->ufrag);
        }
        if (!tsk_params_have_param(self->extension_att_list, "password")){
            tsk_strcat_2(&self->tostring, " password %s", self->pwd);
        }
        if (!tsk_params_have_param(self->extension_att_list, "network_name")){
            tsk_strcat_2(&self->tostring, " network_name %s", "{9EBBE687-CCE6-42D3-87F5-B57BB30DEE23}");
        }
        if (!tsk_params_have_param(self->extension_att_list, "generation")){
            tsk_strcat_2(&self->tostring, " generation %s", "0");
        }
    }
    
    return self->tostring;
}

int tnet_ice_candidate_send_stun_bind_request(tnet_ice_candidate_t* self, const struct sockaddr_storage* server_addr, const char* username, const char* password)
{
    tnet_stun_pkt_t *request = tsk_null;
    tsk_buffer_t *buffer = tsk_null;
    int ret, sendBytes;
    
    if (!self || !server_addr || !TNET_SOCKET_IS_VALID(self->socket)){
        TSK_DEBUG_ERROR("Invalid parameter");
        return -1;
    }
    
    request = _tnet_ice_candidate_stun_create_bind_request(self, username, password);
    if (!request){
        TSK_DEBUG_ERROR("Failed to create STUN request");
        ret = -2;
        goto bail;
    }
    
    if ((ret = tnet_stun_pkt_write_with_padding_2(request, &buffer))){
        TSK_DEBUG_ERROR("Failed to serialize STUN request");
        goto bail;
    }
    
    sendBytes = tnet_sockfd_sendto(self->socket->fd, (const struct sockaddr*)server_addr, buffer->data, buffer->size);// return number of sent bytes
    if (sendBytes == buffer->size){
        memcpy(self->stun.transac_id, request->transac_id, sizeof(tnet_stun_transac_id_t));
        ret = 0;
    }
    else{
        TSK_DEBUG_ERROR("Only %d bytes sent", sendBytes);
        ret = -4;
        goto bail;
    }
    
bail:
    TSK_OBJECT_SAFE_FREE(request);
    TSK_OBJECT_SAFE_FREE(buffer);
    
    return 0;
}

int tnet_ice_candidate_process_stun_response(tnet_ice_candidate_t* self, const tnet_stun_pkt_resp_t* response, tnet_fd_t fd)
{
    int ret = 0;
    
    if (!self || !response){
        TSK_DEBUG_ERROR("Inavlid parameter");
        return -1;
    }
    
    //if(!(_tnet_ice_candidate_stun_transac_id_equals(response->transac_id, self->stun.transac_id))){
    //	TSK_DEBUG_ERROR("Transaction id mismatch");
    //	return -2;
    //}
    
    if (TNET_STUN_PKT_RESP_IS_ERROR(response)) {
        uint16_t u_code;
        if ((ret = tnet_stun_pkt_get_errorcode(response, &u_code))) {
            return ret;
        }
        if (u_code == kStunErrCodeUnauthorized || u_code == kStunErrCodeStaleNonce) {
            const tnet_stun_attr_vdata_t* pc_attr;
            if (u_code == kStunErrCodeUnauthorized) {
                // Make sure this is not an authentication failure (#2 401)
                // Do not send another req to avoid endless messages
                if ((tnet_stun_pkt_attr_exists(response, tnet_stun_attr_type_message_integrity))) { // already has a MESSAGE-INTEGRITY?
                    TSK_DEBUG_ERROR("TURN authentication failed");
                    return -3;
                }
            }
            if ((ret = tnet_stun_pkt_attr_find_first(response, tnet_stun_attr_type_nonce, (const tnet_stun_attr_t**)&pc_attr)) == 0 && pc_attr) {
                tsk_strupdate(&self->stun.nonce, (const char*)pc_attr->p_data_ptr);
            }
            if ((ret = tnet_stun_pkt_attr_find_first(response, tnet_stun_attr_type_realm, (const tnet_stun_attr_t**)&pc_attr)) == 0 && pc_attr) {
                tsk_strupdate(&self->stun.realm, (const char*)pc_attr->p_data_ptr);
            }
            return 0;
        }
        else {
            TSK_DEBUG_ERROR("STUN error: %hu", u_code);
            return -4;
        }
    }
    else if (TNET_STUN_PKT_RESP_IS_SUCCESS(response)) {
        const tnet_stun_attr_address_t* pc_attr_addr;
        if (((ret = tnet_stun_pkt_attr_find_first(response, tnet_stun_attr_type_xor_mapped_address, (const tnet_stun_attr_t**)&pc_attr_addr)) == 0 && pc_attr_addr)
            || ((ret = tnet_stun_pkt_attr_find_first(response, tnet_stun_attr_type_mapped_address, (const tnet_stun_attr_t**)&pc_attr_addr)) == 0 && pc_attr_addr)) {
            tnet_ip_t ip;
            if ((ret = tnet_stun_utils_inet_ntop((pc_attr_addr->e_family == tnet_stun_address_family_ipv6), &pc_attr_addr->address, &ip))) {
                return ret;
            }
            tsk_strupdate(&self->stun.srflx_addr, ip);
            self->stun.srflx_port = pc_attr_addr->u_port;
        }
    }
    
    return ret;
}

const tnet_ice_candidate_t* tnet_ice_candidate_find_by_fd(tnet_ice_candidates_L_t* candidates, tnet_fd_t fd)
{
    if (candidates) {
        const tsk_list_item_t *item;
        const tnet_ice_candidate_t* candidate;
        
        tsk_list_lock(candidates);
        tsk_list_foreach(item, candidates) {
            if (!(candidate = item->data)) {
                continue;
            }
            if (candidate->socket && (candidate->socket->fd == fd)) {
                tsk_list_unlock(candidates);
                return candidate;
            }
        }
    }
    
    return tsk_null;
}

const char* tnet_ice_candidate_get_ufrag(const tnet_ice_candidate_t* self)
{
    if (self){
        return self->ufrag ? self->ufrag : tnet_ice_candidate_get_att_value(self, "username");
    }
    return tsk_null;
}

const char* tnet_ice_candidate_get_pwd(const tnet_ice_candidate_t* self)
{
    if (self){
        return self->pwd ? self->pwd : tnet_ice_candidate_get_att_value(self, "password");
    }
    return tsk_null;
}

static int _tnet_ice_candidate_tostring(
                                        uint8_t* foundation,
                                        uint32_t comp_id,
                                        const char* transport_str,
                                        uint32_t priority,
                                        const char* connection_addr,
                                        tnet_port_t port,
                                        const char* cand_type_str,
                                        const tsk_params_L_t *extension_att_list,
                                        char** output)
{
    if (!output) {
        TSK_DEBUG_ERROR("Invalid argument");
        return -1;
    }
    tsk_sprintf(output, "%s %d %s %d %s %d typ %s",
                foundation,
                comp_id,
                transport_str,
                priority,
                connection_addr,
                port,
                cand_type_str);
    
    if (extension_att_list) {
        const tsk_list_item_t *item;
        tsk_list_foreach(item, extension_att_list){
            tsk_strcat_2(output, " %s %s", TSK_PARAM(item->data)->name, TSK_PARAM(item->data)->value);
        }
    }
    return 0;
}

static const char* _tnet_ice_candidate_get_foundation(tnet_ice_cand_type_t type)
{
    switch (type){
        case tnet_ice_cand_type_host: return TNET_ICE_CANDIDATE_FOUNDATION_HOST;
        case tnet_ice_cand_type_srflx: return TNET_ICE_CANDIDATE_FOUNDATION_SRFLX;
        case tnet_ice_cand_type_prflx: return TNET_ICE_CANDIDATE_FOUNDATION_PRFLX;
        case tnet_ice_cand_type_relay: default: return TNET_ICE_CANDIDATE_FOUNDATION_RELAY;
    }
}


static tsk_bool_t _tnet_ice_candidate_stun_transac_id_equals(const tnet_stun_transac_id_t id1, const tnet_stun_transac_id_t id2)
{
    tsk_size_t i;
    static const tsk_size_t size = sizeof(tnet_stun_transac_id_t);
    for (i = 0; i < size; i++){
        if (id1[i] != id2[i]){
            return tsk_false;
        }
    }
    return tsk_true;
}

static tnet_stun_pkt_t * _tnet_ice_candidate_stun_create_bind_request(tnet_ice_candidate_t* self, const char* username, const char* password)
{
    tnet_stun_pkt_t *request = tsk_null;
    int ret;
    
    if (!self) {
        TSK_DEBUG_ERROR("Invalid parameter");
        return tsk_null;
    }
    
    if ((ret = tnet_stun_pkt_create_empty(tnet_stun_pkt_type_binding_request, &request))) {
        TSK_DEBUG_ERROR("Failed to create STUN Bind request");
        goto bail;
    }
    // add attributes
    request->opt.dontfrag = 0;
    ret = tnet_stun_pkt_attrs_add(request,
                                  TNET_STUN_PKT_ATTR_ADD_SOFTWARE_ZT(kStunSoftware),
                                  TNET_STUN_PKT_ATTR_ADD_NULL());
    if (ret) {
        goto bail;
    }
    if (username && self->stun.realm && self->stun.nonce) {
        if ((ret = tnet_stun_pkt_auth_prepare(request, username, password, self->stun.realm, self->stun.nonce))) {
            goto bail;
        }
    }
    
bail:
    if (ret) {
        TSK_OBJECT_SAFE_FREE(request);
    }
    return request;
}

static const char* _tnet_ice_candidate_get_transport_str(tnet_socket_type_t transport_e)
{
#define TRANSPORT_GET(STR) \
if(TNET_SOCKET_TYPE_IS_##STR(transport_e)){ \
return TNET_ICE_CANDIDATE_TRANSPORT_##STR; \
}
    TRANSPORT_GET(UDP);
    TRANSPORT_GET(TCP);
    TRANSPORT_GET(TLS);
    TRANSPORT_GET(SCTP);
    TRANSPORT_GET(WS);
    TRANSPORT_GET(WSS);
    return "UNKNOWN";
    
#undef TRANSPORT_GET
}

static tnet_socket_type_t _tnet_ice_candidate_get_transport_type(tsk_bool_t ipv6, const char* transport_str)
{
#define TRANSPORT_GET(STR, str) \
if(tsk_striequals(TNET_ICE_CANDIDATE_TRANSPORT_##STR, transport_str)){ \
return tnet_socket_type_##str##_ipv4; \
}
    
    TRANSPORT_GET(UDP, udp);
    TRANSPORT_GET(TCP, tcp);
    TRANSPORT_GET(TLS, tls);
    TRANSPORT_GET(SCTP, sctp);
    TRANSPORT_GET(WS, ws);
    TRANSPORT_GET(WSS, wss);
    return tnet_socket_type_invalid;
    
#undef TRANSPORT_GET
}

static const char* _tnet_ice_candidate_get_candtype_str(tnet_ice_cand_type_t candtype_e)
{
    switch (candtype_e){
        case tnet_ice_cand_type_unknown:
        default: return "unknown";
        case tnet_ice_cand_type_host: return TNET_ICE_CANDIDATE_TYPE_HOST;
        case tnet_ice_cand_type_srflx: return TNET_ICE_CANDIDATE_TYPE_SRFLX;
        case tnet_ice_cand_type_prflx: return TNET_ICE_CANDIDATE_TYPE_PRFLX;
        case tnet_ice_cand_type_relay: return TNET_ICE_CANDIDATE_TYPE_RELAY;
    }
}

static tnet_ice_cand_type_t _tnet_ice_candtype_get_transport_type(const char* candtype_str)
{
    if (tsk_striequals(TNET_ICE_CANDIDATE_TYPE_HOST, candtype_str)){
        return tnet_ice_cand_type_host;
    }
    else if (tsk_striequals(TNET_ICE_CANDIDATE_TYPE_SRFLX, candtype_str)){
        return tnet_ice_cand_type_srflx;
    }
    else if (tsk_striequals(TNET_ICE_CANDIDATE_TYPE_PRFLX, candtype_str)){
        return tnet_ice_cand_type_prflx;
    }
    else if (tsk_striequals(TNET_ICE_CANDIDATE_TYPE_RELAY, candtype_str)){
        return tnet_ice_cand_type_relay;
    }
    else{
        return tnet_ice_cand_type_unknown;
    }
}