/* 
 * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
 * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
 */
#include <pjnath/turn_sock.h>
#include <pj/activesock.h>
#include <pj/ssl_sock.h>
#include <pj/assert.h>
#include <pj/errno.h>
#include <pj/lock.h>
#include <pj/log.h>
#include <pj/pool.h>
#include <pj/ioqueue.h>
#include <pj/compat/socket.h>

enum
{
    TIMER_NONE,
    TIMER_DESTROY
};


enum { MAX_BIND_RETRY = 100 };


#define INIT    0x1FFFFFFF

enum {
    DATACONN_STATE_NULL,
    DATACONN_STATE_INITSOCK,
    DATACONN_STATE_CONN_BINDING,
    DATACONN_STATE_READY,
};

/* This structure describe data connection of TURN TCP allocations
 * (RFC 6062).
 */
typedef struct tcp_data_conn_t
{
    pj_pool_t            *pool;

    pj_uint32_t          id;            /* Connection ID.               */
    int                  state;         /* Connection state.            */
    pj_sockaddr          peer_addr;     /* Peer address (mapped).       */
    unsigned             peer_addr_len;

    pj_activesock_t     *asock;         /* Active socket.               */
    pj_ioqueue_op_key_t  send_key;

    pj_turn_sock        *turn_sock;     /* TURN socket parent.          */
} tcp_data_conn_t;


struct pj_turn_sock
{
    pj_pool_t           *pool;
    const char          *obj_name;
    pj_turn_session     *sess;
    pj_turn_sock_cb      cb;
    void                *user_data;

    pj_bool_t            is_destroying;
    pj_grp_lock_t       *grp_lock;

    pj_turn_alloc_param  alloc_param;
    pj_stun_config       cfg;
    pj_turn_sock_cfg     setting;

    pj_timer_entry       timer;

    int                  af;
    pj_turn_tp_type      conn_type;
    pj_activesock_t     *active_sock;
#if PJ_HAS_SSL_SOCK
    pj_ssl_sock_t       *ssl_sock;
    pj_ssl_cert_t       *cert;
    pj_str_t             server_name;
#endif

    pj_ioqueue_op_key_t  send_key;
    pj_ioqueue_op_key_t  int_send_key;
    unsigned             pkt_len;
    unsigned             body_len;

    /* Data connection, when peer_conn_type==PJ_TURN_TP_TCP (RFC 6062) */
    unsigned             data_conn_cnt;
    tcp_data_conn_t      data_conn[PJ_TURN_MAX_TCP_CONN_CNT];
};


/*
 * Callback prototypes.
 */
static pj_status_t turn_on_send_pkt(pj_turn_session *sess,
                                    const pj_uint8_t *pkt,
                                    unsigned pkt_len,
                                    const pj_sockaddr_t *dst_addr,
                                    unsigned dst_addr_len);
static pj_status_t turn_on_stun_send_pkt(pj_turn_session *sess,
                                         const pj_uint8_t *pkt,
                                         unsigned pkt_len,
                                         const pj_sockaddr_t *dst_addr,
                                         unsigned dst_addr_len);
static void turn_on_channel_bound(pj_turn_session *sess,
                                  const pj_sockaddr_t *peer_addr,
                                  unsigned addr_len,
                                  unsigned ch_num);
static void turn_on_rx_data(pj_turn_session *sess,
                            void *pkt,
                            unsigned pkt_len,
                            const pj_sockaddr_t *peer_addr,
                            unsigned addr_len);
static void turn_on_state(pj_turn_session *sess, 
                          pj_turn_state_t old_state,
                          pj_turn_state_t new_state);
static void turn_on_connection_attempt(pj_turn_session *sess,
                                       pj_uint32_t conn_id,
                                       const pj_sockaddr_t *peer_addr,
                                       unsigned addr_len);
static void turn_on_connection_bind_status(pj_turn_session *sess,
                                           pj_status_t status,
                                           pj_uint32_t conn_id,
                                           const pj_sockaddr_t *peer_addr,
                                           unsigned addr_len);
static void turn_on_connect_complete(pj_turn_session *sess,
                                     pj_status_t status,
                                     pj_uint32_t conn_id,
                                     const pj_sockaddr_t *peer_addr,
                                     unsigned addr_len);

static pj_bool_t on_data_read(pj_turn_sock *turn_sock,
                              void *data,
                              pj_size_t size,
                              pj_status_t status,
                              pj_size_t *remainder);
static pj_bool_t on_data_sent(pj_turn_sock *turn_sock,
                              pj_ioqueue_op_key_t *send_key,
                              pj_ssize_t sent);
static pj_bool_t on_connect_complete(pj_turn_sock *turn_sock,
                                     pj_status_t status);

/*
 * Activesock callback
 */
static pj_bool_t on_connect_complete_asock(pj_activesock_t *asock,
                                           pj_status_t status);
static pj_bool_t on_data_read_asock(pj_activesock_t *asock,
                                    void *data,
                                    pj_size_t size,
                                    pj_status_t status,
                                    pj_size_t *remainder);
static pj_bool_t on_data_sent_asock(pj_activesock_t *asock,
                                     pj_ioqueue_op_key_t *send_key,
                                     pj_ssize_t sent);

/*
 * SSL sock callback
 */
#if PJ_HAS_SSL_SOCK
static pj_bool_t on_connect_complete_ssl_sock(pj_ssl_sock_t *ssl_sock,
                                              pj_status_t status);
static pj_bool_t on_data_read_ssl_sock(pj_ssl_sock_t *ssl_sock,
                                       void *data,
                                       pj_size_t size,
                                       pj_status_t status,
                                       pj_size_t *remainder);
#endif

static pj_bool_t dataconn_on_data_read(pj_activesock_t *asock,
                                       void *data,
                                       pj_size_t size,
                                       pj_status_t status,
                                       pj_size_t *remainder);
static pj_bool_t dataconn_on_data_sent(pj_activesock_t *asock,
                                       pj_ioqueue_op_key_t *send_key,
                                       pj_ssize_t sent);
static pj_bool_t dataconn_on_connect_complete(pj_activesock_t *asock,
                                              pj_status_t status);
static void dataconn_cleanup(tcp_data_conn_t *conn);

static void turn_sock_on_destroy(void *comp);
static void destroy(pj_turn_sock *turn_sock);
static void timer_cb(pj_timer_heap_t *th, pj_timer_entry *e);


/* Init config */
PJ_DEF(void) pj_turn_sock_cfg_default(pj_turn_sock_cfg *cfg)
{
    pj_bzero(cfg, sizeof(*cfg));
    cfg->max_pkt_size = PJ_TURN_MAX_PKT_LEN;
    cfg->qos_type = PJ_QOS_TYPE_BEST_EFFORT;
    cfg->qos_ignore_error = PJ_TRUE;

#if PJ_HAS_SSL_SOCK
    pj_turn_sock_tls_cfg_default(&cfg->tls_cfg);
#endif
}

#if PJ_HAS_SSL_SOCK

PJ_DEF(void) pj_turn_sock_tls_cfg_default(pj_turn_sock_tls_cfg *tls_cfg)
{
    pj_bzero(tls_cfg, sizeof(*tls_cfg));
    pj_ssl_sock_param_default(&tls_cfg->ssock_param);
    tls_cfg->ssock_param.proto = PJ_TURN_TLS_DEFAULT_PROTO;
}

PJ_DEF(void) pj_turn_sock_tls_cfg_dup(pj_pool_t *pool,
                                      pj_turn_sock_tls_cfg *dst,
                                      const pj_turn_sock_tls_cfg *src)
{
    pj_memcpy(dst, src, sizeof(*dst));
    pj_strdup_with_null(pool, &dst->ca_list_file, &src->ca_list_file);
    pj_strdup_with_null(pool, &dst->ca_list_path, &src->ca_list_path);
    pj_strdup_with_null(pool, &dst->cert_file, &src->cert_file);
    pj_strdup_with_null(pool, &dst->privkey_file, &src->privkey_file);
    pj_strdup_with_null(pool, &dst->password, &src->password);
    pj_strdup(pool, &dst->ca_buf, &src->ca_buf);
    pj_strdup(pool, &dst->cert_buf, &src->cert_buf);
    pj_strdup(pool, &dst->privkey_buf, &src->privkey_buf);
    pj_ssl_sock_param_copy(pool, &dst->ssock_param, &src->ssock_param);
}

static void wipe_buf(pj_str_t *buf)
{
    volatile char *p = buf->ptr;
    pj_ssize_t len = buf->slen;
    while (len--) *p++ = 0;
    buf->slen = 0;
}

PJ_DEF(void) pj_turn_sock_tls_cfg_wipe_keys(pj_turn_sock_tls_cfg *tls_cfg)
{
    wipe_buf(&tls_cfg->ca_list_file);
    wipe_buf(&tls_cfg->ca_list_path);
    wipe_buf(&tls_cfg->cert_file);
    wipe_buf(&tls_cfg->privkey_file);
    wipe_buf(&tls_cfg->password);
    wipe_buf(&tls_cfg->ca_buf);
    wipe_buf(&tls_cfg->cert_buf);
    wipe_buf(&tls_cfg->privkey_buf); 
}
#endif

/*
 * Create.
 */
PJ_DEF(pj_status_t) pj_turn_sock_create(pj_stun_config *cfg,
                                        int af,
                                        pj_turn_tp_type conn_type,
                                        const pj_turn_sock_cb *cb,
                                        const pj_turn_sock_cfg *setting,
                                        void *user_data,
                                        pj_turn_sock **p_turn_sock)
{
    pj_turn_sock *turn_sock;
    pj_turn_session_cb sess_cb;
    pj_turn_sock_cfg default_setting;
    pj_pool_t *pool;
    const char *name_tmpl;
    pj_status_t status;

    PJ_ASSERT_RETURN(cfg && p_turn_sock, PJ_EINVAL);
    PJ_ASSERT_RETURN(af==pj_AF_INET() || af==pj_AF_INET6(), PJ_EINVAL);
    PJ_ASSERT_RETURN(conn_type!=PJ_TURN_TP_TCP || PJ_HAS_TCP, PJ_EINVAL);
    PJ_ASSERT_RETURN(conn_type!=PJ_TURN_TP_TLS || PJ_HAS_SSL_SOCK, PJ_EINVAL);

    if (!setting) {
        pj_turn_sock_cfg_default(&default_setting);
        setting = &default_setting;
    }

    switch (conn_type) {
    case PJ_TURN_TP_UDP:
        name_tmpl = "udprel%p";
        break;
    case PJ_TURN_TP_TCP:
        name_tmpl = "tcprel%p";
        break;
#if PJ_HAS_SSL_SOCK
    case PJ_TURN_TP_TLS:
        name_tmpl = "tlsrel%p";
        break;
#endif
    default:
        PJ_ASSERT_RETURN(!"Invalid TURN conn_type", PJ_EINVAL);
        name_tmpl = "tcprel%p";
        break;
    }

    /* Create and init basic data structure */
    pool = pj_pool_create(cfg->pf, name_tmpl, PJNATH_POOL_LEN_TURN_SOCK,
                          PJNATH_POOL_INC_TURN_SOCK, NULL);
    turn_sock = PJ_POOL_ZALLOC_T(pool, pj_turn_sock);
    turn_sock->pool = pool;
    turn_sock->obj_name = pool->obj_name;
    turn_sock->user_data = user_data;
    turn_sock->af = af;
    turn_sock->conn_type = conn_type;

    /* Copy STUN config (this contains ioqueue, timer heap, etc.) */
    pj_memcpy(&turn_sock->cfg, cfg, sizeof(*cfg));

    /* Copy setting (QoS parameters etc */
    pj_memcpy(&turn_sock->setting, setting, sizeof(*setting));
#if PJ_HAS_SSL_SOCK
    pj_turn_sock_tls_cfg_dup(turn_sock->pool, &turn_sock->setting.tls_cfg,
                             &setting->tls_cfg);
#endif

    /* Set callback */
    if (cb) {
        pj_memcpy(&turn_sock->cb, cb, sizeof(*cb));
    }

    /* Session lock */
    if (setting->grp_lock) {
        turn_sock->grp_lock = setting->grp_lock;
    } else {
        status = pj_grp_lock_create(pool, NULL, &turn_sock->grp_lock);
        if (status != PJ_SUCCESS) {
            pj_pool_release(pool);
            return status;
        }
    }

    pj_grp_lock_add_ref(turn_sock->grp_lock);
    pj_grp_lock_add_handler(turn_sock->grp_lock, pool, turn_sock,
                            &turn_sock_on_destroy);

    /* Init timer */
    pj_timer_entry_init(&turn_sock->timer, TIMER_NONE, turn_sock, &timer_cb);

    /* Init TURN session */
    pj_bzero(&sess_cb, sizeof(sess_cb));
    sess_cb.on_send_pkt = &turn_on_send_pkt;
    sess_cb.on_stun_send_pkt = &turn_on_stun_send_pkt;
    sess_cb.on_channel_bound = &turn_on_channel_bound;
    sess_cb.on_rx_data = &turn_on_rx_data;
    sess_cb.on_state = &turn_on_state;
    sess_cb.on_connect_complete = &turn_on_connect_complete;
    sess_cb.on_connection_attempt = &turn_on_connection_attempt;
    sess_cb.on_connection_bind_status = &turn_on_connection_bind_status;
    status = pj_turn_session_create(cfg, pool->obj_name, af, conn_type,
                                    turn_sock->grp_lock, &sess_cb, 0,
                                    turn_sock, &turn_sock->sess);
    if (status != PJ_SUCCESS) {
        destroy(turn_sock);
        return status;
    }

    /* Note: socket and ioqueue will be created later once the TURN server
     * has been resolved.
     */

    *p_turn_sock = turn_sock;
    return PJ_SUCCESS;
}

/*
 * Destroy.
 */
static void turn_sock_on_destroy(void *comp)
{
    pj_turn_sock *turn_sock = (pj_turn_sock*) comp;

    if (turn_sock->pool) {
        PJ_LOG(4,(turn_sock->obj_name, "TURN socket destroyed"));
        pj_pool_safe_release(&turn_sock->pool);
    }
}

static void destroy(pj_turn_sock *turn_sock)
{
    unsigned i;

    PJ_LOG(4,(turn_sock->obj_name, "TURN socket destroy request, ref_cnt=%d",
              pj_grp_lock_get_ref(turn_sock->grp_lock)));

    pj_grp_lock_acquire(turn_sock->grp_lock);
    if (turn_sock->is_destroying) {
        pj_grp_lock_release(turn_sock->grp_lock);
        return;
    }

    turn_sock->is_destroying = PJ_TRUE;
    if (turn_sock->sess)
        pj_turn_session_shutdown(turn_sock->sess);
    if (turn_sock->active_sock)
        pj_activesock_close(turn_sock->active_sock);
#if PJ_HAS_SSL_SOCK
    if (turn_sock->ssl_sock)
        pj_ssl_sock_close(turn_sock->ssl_sock);
#endif

    for (i=0; i < PJ_TURN_MAX_TCP_CONN_CNT; ++i) {
        dataconn_cleanup(&turn_sock->data_conn[i]);
    }
    turn_sock->data_conn_cnt = 0;

    pj_grp_lock_dec_ref(turn_sock->grp_lock);
    pj_grp_lock_release(turn_sock->grp_lock);
}

static void turn_sock_destroy(pj_turn_sock *turn_sock,
			                  pj_status_t last_err)
{
    pj_grp_lock_acquire(turn_sock->grp_lock);
    if (turn_sock->is_destroying) {
        pj_grp_lock_release(turn_sock->grp_lock);
        return;
    }

    if (turn_sock->sess) {
        pj_turn_session_shutdown2(turn_sock->sess, last_err);
        /* This will ultimately call our state callback, and when
         * session state is DESTROYING we will schedule a timer to
         * destroy ourselves.
         */
    } else {
        destroy(turn_sock);
    }

    pj_grp_lock_release(turn_sock->grp_lock);
}

PJ_DEF(void) pj_turn_sock_destroy(pj_turn_sock *turn_sock)
{
    turn_sock_destroy(turn_sock, PJ_SUCCESS);
}

/* Timer callback */
static void timer_cb(pj_timer_heap_t *th, pj_timer_entry *e)
{
    pj_turn_sock *turn_sock = (pj_turn_sock*)e->user_data;
    int eid = e->id;

    PJ_UNUSED_ARG(th);

    e->id = TIMER_NONE;

    switch (eid) {
    case TIMER_DESTROY:
        destroy(turn_sock);
        break;
    default:
        pj_assert(!"Invalid timer id");
        break;
    }
}


/* Display error */
static void show_err(pj_turn_sock *turn_sock, const char *title,
                     pj_status_t status)
{
    PJ_PERROR(4,(turn_sock->obj_name, status, "%s", title));
}

/* On error, terminate session */
static void sess_fail(pj_turn_sock *turn_sock, const char *title,
                      pj_status_t status)
{
    show_err(turn_sock, title, status);
    if (turn_sock->sess) {
        pj_turn_session_destroy(turn_sock->sess, status);
    }
}

/*
 * Set user data.
 */
PJ_DEF(pj_status_t) pj_turn_sock_set_user_data( pj_turn_sock *turn_sock,
                                               void *user_data)
{
    PJ_ASSERT_RETURN(turn_sock, PJ_EINVAL);
    turn_sock->user_data = user_data;
    return PJ_SUCCESS;
}

/*
 * Get user data.
 */
PJ_DEF(void*) pj_turn_sock_get_user_data(pj_turn_sock *turn_sock)
{
    PJ_ASSERT_RETURN(turn_sock, NULL);
    return turn_sock->user_data;
}

/*
 * Get group lock.
 */
PJ_DEF(pj_grp_lock_t *) pj_turn_sock_get_grp_lock(pj_turn_sock *turn_sock)
{
    PJ_ASSERT_RETURN(turn_sock, NULL);
    return turn_sock->grp_lock;
}

/**
 * Get info.
 */
PJ_DEF(pj_status_t) pj_turn_sock_get_info(pj_turn_sock *turn_sock,
                                          pj_turn_session_info *info)
{
    PJ_ASSERT_RETURN(turn_sock && info, PJ_EINVAL);

    if (turn_sock->sess) {
        return pj_turn_session_get_info(turn_sock->sess, info);
    } else {
        pj_bzero(info, sizeof(*info));
        info->state = PJ_TURN_STATE_NULL;
        return PJ_SUCCESS;
    }
}

/**
 * Lock the TURN socket. Application may need to call this function to
 * synchronize access to other objects to avoid deadlock.
 */
PJ_DEF(pj_status_t) pj_turn_sock_lock(pj_turn_sock *turn_sock)
{
    return pj_grp_lock_acquire(turn_sock->grp_lock);
}

/**
 * Unlock the TURN socket.
 */
PJ_DEF(pj_status_t) pj_turn_sock_unlock(pj_turn_sock *turn_sock)
{
    return pj_grp_lock_release(turn_sock->grp_lock);
}

/*
 * Set STUN message logging for this TURN session. 
 */
PJ_DEF(void) pj_turn_sock_set_log( pj_turn_sock *turn_sock,
                                   unsigned flags)
{
    pj_turn_session_set_log(turn_sock->sess, flags);
}

/*
 * Set software name
 */
PJ_DEF(pj_status_t) pj_turn_sock_set_software_name( pj_turn_sock *turn_sock,
                                                    const pj_str_t *sw)
{
    return pj_turn_session_set_software_name(turn_sock->sess, sw);
}

/*
 * Initialize.
 */
PJ_DEF(pj_status_t) pj_turn_sock_alloc(pj_turn_sock *turn_sock,
                                       const pj_str_t *domain,
                                       int default_port,
                                       pj_dns_resolver *resolver,
                                       const pj_stun_auth_cred *cred,
                                       const pj_turn_alloc_param *param)
{
    pj_status_t status;

    PJ_ASSERT_RETURN(turn_sock && domain, PJ_EINVAL);
    PJ_ASSERT_RETURN(turn_sock->sess, PJ_EINVALIDOP);

    pj_grp_lock_acquire(turn_sock->grp_lock);

    /* Copy alloc param. We will call session_alloc() only after the 
     * server address has been resolved.
     */
    if (param) {
        pj_turn_alloc_param_copy(turn_sock->pool, &turn_sock->alloc_param, param);
    } else {
        pj_turn_alloc_param_default(&turn_sock->alloc_param);
    }

    /* Set credental */
    if (cred) {
        status = pj_turn_session_set_credential(turn_sock->sess, cred);
        if (status != PJ_SUCCESS) {
            sess_fail(turn_sock, "Error setting credential", status);
            pj_grp_lock_release(turn_sock->grp_lock);
            return status;
        }
    }
#if PJ_HAS_SSL_SOCK
    if (turn_sock->conn_type == PJ_TURN_TP_TLS) {
        pj_strdup_with_null(turn_sock->pool, &turn_sock->server_name, domain);
    }
#endif

    /* Resolve server */
    status = pj_turn_session_set_server(turn_sock->sess, domain, default_port,
                                        resolver);
    if (status != PJ_SUCCESS) {
        sess_fail(turn_sock, "Error setting TURN server", status);
        pj_grp_lock_release(turn_sock->grp_lock);
        return status;
    } else if (!turn_sock->sess) {
        /* TURN session may have been destroyed here, i.e: when DNS resolution
         * completed synchronously and TURN allocation failed.
         */
        PJ_LOG(4,(turn_sock->obj_name, "TURN session destroyed in setting "
                                       "TURN server"));
        pj_grp_lock_release(turn_sock->grp_lock);
        return PJ_EGONE;
    }

    /* Done for now. The next work will be done when session state moved
     * to RESOLVED state.
     */
    pj_grp_lock_release(turn_sock->grp_lock);
    return PJ_SUCCESS;
}

/*
 * Install permission
 */
PJ_DEF(pj_status_t) pj_turn_sock_set_perm( pj_turn_sock *turn_sock,
                                           unsigned addr_cnt,
                                           const pj_sockaddr addr[],
                                           unsigned options)
{
    if (turn_sock->sess == NULL)
        return PJ_EINVALIDOP;

    return pj_turn_session_set_perm(turn_sock->sess, addr_cnt, addr, options);
}

/*
 * Send packet.
 */ 
PJ_DEF(pj_status_t) pj_turn_sock_sendto( pj_turn_sock *turn_sock,
                                        const pj_uint8_t *pkt,
                                        unsigned pkt_len,
                                        const pj_sockaddr_t *addr,
                                        unsigned addr_len)
{
    PJ_ASSERT_RETURN(turn_sock && addr && addr_len, PJ_EINVAL);

    if (turn_sock->sess == NULL)
        return PJ_EINVALIDOP;

    /* TURN session may add some headers to the packet, so we need
     * to store our actual data length to be sent here.
     */
    turn_sock->body_len = pkt_len;
    return pj_turn_session_sendto(turn_sock->sess, pkt, pkt_len, 
                                  addr, addr_len);
}

/*
 * Bind a peer address to a channel number.
 */
PJ_DEF(pj_status_t) pj_turn_sock_bind_channel( pj_turn_sock *turn_sock,
                                              const pj_sockaddr_t *peer,
                                              unsigned addr_len)
{
    PJ_ASSERT_RETURN(turn_sock && peer && addr_len, PJ_EINVAL);
    PJ_ASSERT_RETURN(turn_sock->sess != NULL, PJ_EINVALIDOP);

    return pj_turn_session_bind_channel(turn_sock->sess, peer, addr_len);
}

/**
 * Send Connect request for the specified a peer address.
 */
PJ_DEF(pj_status_t) pj_turn_sock_connect( pj_turn_sock *turn_sock,
                                         const pj_sockaddr_t *peer_addr,
                                         unsigned addr_len)
{
    PJ_ASSERT_RETURN(turn_sock && peer_addr && addr_len, PJ_EINVAL);
    PJ_ASSERT_RETURN(turn_sock->sess != NULL, PJ_EINVALIDOP);

    return pj_turn_session_connect(turn_sock->sess, peer_addr, addr_len);
}

/**
 * Close existing connection to the peer address.
 */
PJ_DEF(pj_status_t) pj_turn_sock_disconnect( pj_turn_sock *turn_sock,
                                          const pj_sockaddr_t *peer_addr,
                                          unsigned addr_len)

{
    unsigned i;
    char addrtxt[PJ_INET6_ADDRSTRLEN+8];

    PJ_ASSERT_RETURN(turn_sock && peer_addr && addr_len, PJ_EINVAL);
    PJ_ASSERT_RETURN(turn_sock->sess != NULL, PJ_EINVALIDOP);

    pj_grp_lock_acquire(turn_sock->grp_lock);
    for (i=0; i < PJ_TURN_MAX_TCP_CONN_CNT; ++i) {
        tcp_data_conn_t *conn = &turn_sock->data_conn[i];
        if (conn->state < DATACONN_STATE_CONN_BINDING)
            continue;
        if (pj_sockaddr_cmp(&conn->peer_addr, peer_addr) == 0) {
            dataconn_cleanup(conn);
            --turn_sock->data_conn_cnt;
            pj_grp_lock_release(turn_sock->grp_lock);
            return PJ_SUCCESS;
        }
    }

    PJ_LOG(4, (turn_sock->obj_name, "Connection for peer %s is not exist",
               pj_sockaddr_print(peer_addr, addrtxt, sizeof(addrtxt), 3)));

    pj_grp_lock_release(turn_sock->grp_lock);
    return PJ_ENOTFOUND;
}


/*
 * Notification when outgoing TCP socket has been connected.
 */
static pj_bool_t on_connect_complete(pj_turn_sock *turn_sock,
                                     pj_status_t status)
{
    pj_grp_lock_acquire(turn_sock->grp_lock);

    /* TURN session may have already been destroyed here.
     * See ticket #1557 (https://github.com/pjsip/pjproject/issues/1557).
     */
    if (!turn_sock->sess) {
        sess_fail(turn_sock, "TURN session already destroyed", status);
        pj_grp_lock_release(turn_sock->grp_lock);
        return PJ_FALSE;
    }

    if (status != PJ_SUCCESS) {
        if (turn_sock->conn_type == PJ_TURN_TP_UDP)
            sess_fail(turn_sock, "UDP connect() error", status);
        else if (turn_sock->conn_type == PJ_TURN_TP_TCP)
            sess_fail(turn_sock, "TCP connect() error", status);
        else if (turn_sock->conn_type == PJ_TURN_TP_TLS)
            sess_fail(turn_sock, "TLS connect() error", status);

        pj_grp_lock_release(turn_sock->grp_lock);
        return PJ_FALSE;
    }

    if (turn_sock->conn_type != PJ_TURN_TP_UDP) {
        PJ_LOG(5, (turn_sock->obj_name, "%s connected",
                   turn_sock->conn_type == PJ_TURN_TP_TCP ? "TCP" : "TLS"));
    }

    /* Kick start pending read operation */
    if (turn_sock->conn_type != PJ_TURN_TP_TLS) 
        status = pj_activesock_start_read(turn_sock->active_sock, 
                                          turn_sock->pool,
                                          turn_sock->setting.max_pkt_size, 
                                          0);
#if PJ_HAS_SSL_SOCK
    else
        status = pj_ssl_sock_start_read(turn_sock->ssl_sock, turn_sock->pool,
                                        turn_sock->setting.max_pkt_size, 0);
#endif
    if (status != PJ_SUCCESS) {
        sess_fail(turn_sock, "Error in start_read", status);
        pj_grp_lock_release(turn_sock->grp_lock);
        return PJ_FALSE;
    }

    /* Init send_key */
    pj_ioqueue_op_key_init(&turn_sock->send_key, sizeof(turn_sock->send_key));
    pj_ioqueue_op_key_init(&turn_sock->int_send_key,
                           sizeof(turn_sock->int_send_key));

    /* Send Allocate request */
    status = pj_turn_session_alloc(turn_sock->sess, &turn_sock->alloc_param);
    if (status != PJ_SUCCESS) {
        sess_fail(turn_sock, "Error sending ALLOCATE", status);
        pj_grp_lock_release(turn_sock->grp_lock);
        return PJ_FALSE;
    }

    pj_grp_lock_release(turn_sock->grp_lock);
    return PJ_TRUE;
}

static pj_bool_t on_connect_complete_asock(pj_activesock_t *asock,
                                           pj_status_t status)
{
    pj_turn_sock *turn_sock;

    turn_sock = (pj_turn_sock*)pj_activesock_get_user_data(asock);
    if (!turn_sock)
        return PJ_FALSE;

    return on_connect_complete(turn_sock, status);
}

#if PJ_HAS_SSL_SOCK
static pj_bool_t on_connect_complete_ssl_sock(pj_ssl_sock_t *ssl_sock,
                                              pj_status_t status)
{
    pj_turn_sock *turn_sock;

    turn_sock = (pj_turn_sock*)pj_ssl_sock_get_user_data(ssl_sock);
    if (!turn_sock)
        return PJ_FALSE;

    return on_connect_complete(turn_sock, status);
}
#endif

static pj_uint16_t GETVAL16H(const pj_uint8_t *buf, unsigned pos)
{
    return (pj_uint16_t) ((buf[pos + 0] << 8) | \
                          (buf[pos + 1] << 0));
}

/* Quick check to determine if there is enough packet to process in the
 * incoming buffer. Return the packet length, or zero if there's no packet.
 */
static unsigned has_packet(pj_turn_sock *turn_sock, const void *buf, pj_size_t bufsize)
{
    pj_bool_t is_stun;

    if (turn_sock->conn_type == PJ_TURN_TP_UDP)
        return (unsigned)bufsize;

    /* Quickly check if this is STUN message, by checking the first two bits and
     * size field which must be multiple of 4 bytes
     */
    is_stun = ((((pj_uint8_t*)buf)[0] & 0xC0) == 0) &&
              ((GETVAL16H((const pj_uint8_t*)buf, 2) & 0x03)==0);

    if (is_stun) {
        pj_size_t msg_len = GETVAL16H((const pj_uint8_t*)buf, 2);
        return (unsigned)((msg_len+20 <= bufsize) ? msg_len+20 : 0);
    } else {
        /* This must be ChannelData. */
        pj_turn_channel_data cd;

        if (bufsize < 4)
            return 0;

        /* Decode ChannelData packet */
        pj_memcpy(&cd, buf, sizeof(pj_turn_channel_data));
        cd.length = pj_ntohs(cd.length);

        if (bufsize >= cd.length+sizeof(cd)) 
            return (cd.length+sizeof(cd)+3) & (~3);
        else
            return 0;
    }
}

/*
 * Notification from ioqueue when incoming UDP packet is received.
 */
static pj_bool_t on_data_read(pj_turn_sock *turn_sock,
                              void *data,
                              pj_size_t size,
                              pj_status_t status,
                              pj_size_t *remainder)
{
    pj_bool_t ret = PJ_TRUE;

    pj_grp_lock_acquire(turn_sock->grp_lock);

    if (status == PJ_SUCCESS && turn_sock->sess && !turn_sock->is_destroying) {
        /* Report incoming packet to TURN session, repeat while we have
         * "packet" in the buffer (required for stream-oriented transports)
         */
        unsigned pkt_len;

        //PJ_LOG(5,(turn_sock->pool->obj_name, 
        //        "Incoming data, %lu bytes total buffer", size));

        while ((pkt_len=has_packet(turn_sock, data, size)) != 0) {
            pj_size_t parsed_len;
            //const pj_uint8_t *pkt = (const pj_uint8_t*)data;

            //PJ_LOG(5,(turn_sock->pool->obj_name, 
            //        "Packet start: %02X %02X %02X %02X", 
            //        pkt[0], pkt[1], pkt[2], pkt[3]));

            //PJ_LOG(5,(turn_sock->pool->obj_name, 
            //        "Processing %lu bytes packet of %lu bytes total buffer",
            //        pkt_len, size));

            parsed_len = (unsigned)size;
            pj_turn_session_on_rx_pkt(turn_sock->sess, data,  size, &parsed_len);

            /* parsed_len may be zero if we have parsing error, so use our
             * previous calculation to exhaust the bad packet.
             */
            if (parsed_len == 0)
                parsed_len = pkt_len;

            if (parsed_len < (unsigned)size) {
                *remainder = size - parsed_len;
                pj_memmove(data, ((char*)data)+parsed_len, *remainder);
            } else {
                *remainder = 0;
            }
            size = *remainder;

            //PJ_LOG(5,(turn_sock->pool->obj_name, 
            //        "Buffer size now %lu bytes", size));
        }
    } else if (status != PJ_SUCCESS) {
        if (turn_sock->conn_type == PJ_TURN_TP_UDP)
            sess_fail(turn_sock, "UDP connection closed", status);
        else if (turn_sock->conn_type == PJ_TURN_TP_TCP)
            sess_fail(turn_sock, "TCP connection closed", status);
        else if (turn_sock->conn_type == PJ_TURN_TP_TLS)
            sess_fail(turn_sock, "TLS connection closed", status);

        ret = PJ_FALSE;
        goto on_return;
    }

on_return:
    pj_grp_lock_release(turn_sock->grp_lock);

    return ret;
}

static pj_bool_t on_data_read_asock(pj_activesock_t *asock,
                                    void *data,
                                    pj_size_t size,
                                    pj_status_t status,
                                    pj_size_t *remainder)
{
    pj_turn_sock *turn_sock;

    turn_sock = (pj_turn_sock*)pj_activesock_get_user_data(asock);

    return on_data_read(turn_sock, data, size, status, remainder);
}

static pj_bool_t on_data_sent(pj_turn_sock *turn_sock,
                              pj_ioqueue_op_key_t *send_key,
                              pj_ssize_t sent)
{
    /* Don't report to callback if this is internal message. */
    if (send_key == &turn_sock->int_send_key) {
        return PJ_TRUE;
    }

    if (turn_sock->cb.on_data_sent) {
        pj_ssize_t header_len, sent_size;

        /* Remove the length of packet header from sent size. */
        header_len = turn_sock->pkt_len - turn_sock->body_len;
        sent_size = (sent > header_len)? (sent - header_len) : 0;
        (*turn_sock->cb.on_data_sent)(turn_sock, sent_size);
    }

    return PJ_TRUE;
}


static pj_bool_t on_data_sent_asock(pj_activesock_t *asock,
                                     pj_ioqueue_op_key_t *send_key,
                                     pj_ssize_t sent)
{
    pj_turn_sock *turn_sock;

    turn_sock = (pj_turn_sock*)pj_activesock_get_user_data(asock);

    return on_data_sent(turn_sock, send_key, sent);
}


#if PJ_HAS_SSL_SOCK
static pj_bool_t on_data_read_ssl_sock(pj_ssl_sock_t *ssl_sock,
                                       void *data,
                                       pj_size_t size,
                                       pj_status_t status,
                                       pj_size_t *remainder)
{
    pj_turn_sock *turn_sock;

    turn_sock = (pj_turn_sock*)pj_ssl_sock_get_user_data(ssl_sock);

    return on_data_read(turn_sock, data, size, status, remainder);
}

static pj_bool_t on_data_sent_ssl_sock(pj_ssl_sock_t *ssl_sock,
                                       pj_ioqueue_op_key_t *op_key,
                                       pj_ssize_t bytes_sent)
{
    pj_turn_sock *turn_sock;

    PJ_UNUSED_ARG(op_key);

    turn_sock = (pj_turn_sock*)pj_ssl_sock_get_user_data(ssl_sock);

    /* Check for error/closure */
    if (bytes_sent <= 0) {
        pj_status_t status;

        status = (bytes_sent == 0) ? PJ_RETURN_OS_ERROR(OSERR_ENOTCONN) :
            (pj_status_t)-bytes_sent;

        sess_fail(turn_sock, "TLS send() error", status);

        return PJ_FALSE;
    }

    return on_data_sent(turn_sock, op_key, bytes_sent);
}
#endif


static pj_status_t send_pkt(pj_turn_session *sess,
                            pj_bool_t internal,
                            const pj_uint8_t *pkt,
                            unsigned pkt_len,
                            const pj_sockaddr_t *dst_addr,
                            unsigned dst_addr_len)
{
    pj_turn_sock *turn_sock = (pj_turn_sock*) 
                              pj_turn_session_get_user_data(sess);
    pj_ssize_t len = pkt_len;
    pj_status_t status = PJ_SUCCESS;
    pj_ioqueue_op_key_t *send_key = &turn_sock->send_key;

    if (turn_sock == NULL || turn_sock->is_destroying) {
        /* We've been destroyed */
        // https://github.com/pjsip/pjproject/issues/1316
        //pj_assert(!"We should shutdown gracefully");
        return PJ_EINVALIDOP;
    }

    if (internal)
        send_key = &turn_sock->int_send_key;
    turn_sock->pkt_len = pkt_len;

    if (turn_sock->conn_type == PJ_TURN_TP_UDP) {
        status = pj_activesock_sendto(turn_sock->active_sock,
                                      send_key, pkt, &len, 0,
                                      dst_addr, dst_addr_len);
    } else if (turn_sock->alloc_param.peer_conn_type == PJ_TURN_TP_TCP) {
        pj_turn_session_info info;
        pj_turn_session_get_info(turn_sock->sess, &info);
        if (pj_sockaddr_cmp(&info.server, dst_addr) == 0) {
            /* Destination address is TURN server */
            status = pj_activesock_send(turn_sock->active_sock,
                                        send_key, pkt, &len, 0);
        } else {
            /* Destination address is peer, lookup data connection */
            unsigned i;

            status = PJ_ENOTFOUND;
            for (i=0; i < PJ_TURN_MAX_TCP_CONN_CNT; ++i) {
                tcp_data_conn_t *conn = &turn_sock->data_conn[i];
                if (conn->state < DATACONN_STATE_CONN_BINDING)
                    continue;
                if (pj_sockaddr_cmp(&conn->peer_addr, dst_addr) == 0) {
                    status = pj_activesock_send(conn->asock,
                                                &conn->send_key,
                                                pkt, &len, 0);
                    break;
                }
            }
        }
    } else  if (turn_sock->conn_type == PJ_TURN_TP_TCP) {
        status = pj_activesock_send(turn_sock->active_sock,
                                    send_key, pkt, &len, 0);
    }
#if PJ_HAS_SSL_SOCK
    else if (turn_sock->conn_type == PJ_TURN_TP_TLS) {
        status = pj_ssl_sock_send(turn_sock->ssl_sock,
                                  send_key, pkt, &len, 0);
    }
#endif
    else {
        PJ_ASSERT_RETURN(!"Invalid TURN conn_type", PJ_EINVAL);
    }

    if (status != PJ_SUCCESS && status != PJ_EPENDING) {
        show_err(turn_sock, "socket send()", status);
    }

    return status;
}


/*
 * Callback from TURN session to send outgoing packet.
 */
static pj_status_t turn_on_send_pkt(pj_turn_session *sess,
                                    const pj_uint8_t *pkt,
                                    unsigned pkt_len,
                                    const pj_sockaddr_t *dst_addr,
                                    unsigned dst_addr_len)
{
    return send_pkt(sess, PJ_FALSE, pkt, pkt_len,
                    dst_addr, dst_addr_len);
}

static pj_status_t turn_on_stun_send_pkt(pj_turn_session *sess,
                                         const pj_uint8_t *pkt,
                                         unsigned pkt_len,
                                         const pj_sockaddr_t *dst_addr,
                                         unsigned dst_addr_len)
{
    return send_pkt(sess, PJ_TRUE, pkt, pkt_len,
                    dst_addr, dst_addr_len);
}


/*
 * Callback from TURN session when a channel is successfully bound.
 */
static void turn_on_channel_bound(pj_turn_session *sess,
                                  const pj_sockaddr_t *peer_addr,
                                  unsigned addr_len,
                                  unsigned ch_num)
{
    PJ_UNUSED_ARG(sess);
    PJ_UNUSED_ARG(peer_addr);
    PJ_UNUSED_ARG(addr_len);
    PJ_UNUSED_ARG(ch_num);
}


/*
 * Callback from TURN session upon incoming data.
 */
static void turn_on_rx_data(pj_turn_session *sess,
                            void *pkt,
                            unsigned pkt_len,
                            const pj_sockaddr_t *peer_addr,
                            unsigned addr_len)
{
    pj_turn_sock *turn_sock = (pj_turn_sock*) 
                           pj_turn_session_get_user_data(sess);
    if (turn_sock == NULL || turn_sock->is_destroying) {
        /* We've been destroyed */
        return;
    }

    if (turn_sock->alloc_param.peer_conn_type != PJ_TURN_TP_UDP) {
        /* Data traffic for RFC 6062 is not via TURN session */
        return;
    }

    if (turn_sock->cb.on_rx_data) {
        (*turn_sock->cb.on_rx_data)(turn_sock, pkt, pkt_len, 
                                  peer_addr, addr_len);
    }
}


/*
 * Callback from TURN session when state has changed
 */
static void turn_on_state(pj_turn_session *sess, 
                          pj_turn_state_t old_state,
                          pj_turn_state_t new_state)
{
    pj_turn_sock *turn_sock = (pj_turn_sock*) 
                           pj_turn_session_get_user_data(sess);
    pj_status_t status = PJ_SUCCESS;

    if (turn_sock == NULL) {
        /* We've been destroyed */
        return;
    }

    /* Notify app first */
    if (turn_sock->cb.on_state) {
        (*turn_sock->cb.on_state)(turn_sock, old_state, new_state);
    }

    pj_grp_lock_acquire(turn_sock->grp_lock);

    /* Make sure user hasn't destroyed us in the callback */
    if (turn_sock->sess && new_state == PJ_TURN_STATE_RESOLVED) {
        pj_turn_session_info info;
        pj_turn_session_get_info(turn_sock->sess, &info);
        new_state = info.state;
    }

    if (turn_sock->sess && new_state == PJ_TURN_STATE_RESOLVED) {
        /*
         * Once server has been resolved, initiate outgoing TCP
         * connection to the server.
         */
        pj_turn_session_info info;
        char addrtxt[PJ_INET6_ADDRSTRLEN+8];
        int sock_type;
        pj_sock_t sock;
        pj_activesock_cfg asock_cfg;
        pj_activesock_cb asock_cb;
        pj_sockaddr bound_addr, *cfg_bind_addr;
        pj_uint16_t max_bind_retry;

        /* Close existing connection, if any. This happens when
         * we're switching to alternate TURN server when either TCP
         * connection or ALLOCATE request failed.
         */
        if ((turn_sock->conn_type != PJ_TURN_TP_TLS) && 
            (turn_sock->active_sock)) 
        {
            pj_activesock_close(turn_sock->active_sock);
            turn_sock->active_sock = NULL;
        }
#if PJ_HAS_SSL_SOCK
        else if ((turn_sock->conn_type == PJ_TURN_TP_TLS) &&
            (turn_sock->ssl_sock))
        {
            pj_ssl_sock_close(turn_sock->ssl_sock);
            turn_sock->ssl_sock = NULL;
        }
#endif
        /* Get server address from session info */
        pj_turn_session_get_info(sess, &info);

        if (turn_sock->conn_type == PJ_TURN_TP_UDP)
            sock_type = pj_SOCK_DGRAM();
        else
            sock_type = pj_SOCK_STREAM();
        sock_type |= pj_SOCK_CLOEXEC();

        cfg_bind_addr = &turn_sock->setting.bound_addr;
        max_bind_retry = MAX_BIND_RETRY;
        if (turn_sock->setting.port_range &&
            turn_sock->setting.port_range < max_bind_retry)
        {
            max_bind_retry = turn_sock->setting.port_range;
        }
        pj_sockaddr_init(turn_sock->af, &bound_addr, NULL, 0);
        if (cfg_bind_addr->addr.sa_family == pj_AF_INET() || 
            cfg_bind_addr->addr.sa_family == pj_AF_INET6())
        {
            pj_sockaddr_cp(&bound_addr, cfg_bind_addr);
        }

        if (turn_sock->conn_type != PJ_TURN_TP_TLS) {
            /* Init socket */
            status = pj_sock_socket(turn_sock->af, sock_type, 0, &sock);
            if (status != PJ_SUCCESS) {
                turn_sock_destroy(turn_sock, status);
                pj_grp_lock_release(turn_sock->grp_lock);
                return;
            }

            /* Bind socket */
            status = pj_sock_bind_random(sock, &bound_addr,
                                         turn_sock->setting.port_range,
                                         max_bind_retry);
            if (status != PJ_SUCCESS) {
                pj_sock_close(sock);
                turn_sock_destroy(turn_sock, status);
                pj_grp_lock_release(turn_sock->grp_lock);
                return;
            }
            /* Apply QoS, if specified */
            status = pj_sock_apply_qos2(sock, turn_sock->setting.qos_type,
                                    &turn_sock->setting.qos_params,
                                    (turn_sock->setting.qos_ignore_error?2:1),
                                    turn_sock->pool->obj_name, NULL);
            if (status != PJ_SUCCESS && !turn_sock->setting.qos_ignore_error) 
            {
                pj_sock_close(sock);
                turn_sock_destroy(turn_sock, status);
                pj_grp_lock_release(turn_sock->grp_lock);
                return;
            }

            /* Apply socket buffer size */
            if (turn_sock->setting.so_rcvbuf_size > 0) {
                unsigned sobuf_size = turn_sock->setting.so_rcvbuf_size;
                status = pj_sock_setsockopt_sobuf(sock, pj_SO_RCVBUF(),
                                                  PJ_TRUE, &sobuf_size);
                if (status != PJ_SUCCESS) {
                    pj_perror(3, turn_sock->obj_name, status,
                              "Failed setting SO_RCVBUF");
                } else {
                    if (sobuf_size < turn_sock->setting.so_rcvbuf_size) {
                        PJ_LOG(4, (turn_sock->obj_name,
                                "Warning! Cannot set SO_RCVBUF as configured,"
                                " now=%d, configured=%d", sobuf_size,
                                turn_sock->setting.so_rcvbuf_size));
                    } else {
                        PJ_LOG(5, (turn_sock->obj_name, "SO_RCVBUF set to %d",
                                   sobuf_size));
                    }
                }
            }
            if (turn_sock->setting.so_sndbuf_size > 0) {
                unsigned sobuf_size = turn_sock->setting.so_sndbuf_size;
                status = pj_sock_setsockopt_sobuf(sock, pj_SO_SNDBUF(),
                                                  PJ_TRUE, &sobuf_size);
                if (status != PJ_SUCCESS) {
                    pj_perror(3, turn_sock->obj_name, status,
                              "Failed setting SO_SNDBUF");
                } else {
                    if (sobuf_size < turn_sock->setting.so_sndbuf_size) {
                        PJ_LOG(4, (turn_sock->obj_name,
                                "Warning! Cannot set SO_SNDBUF as configured,"
                                " now=%d, configured=%d", sobuf_size,
                                turn_sock->setting.so_sndbuf_size));
                    } else {
                        PJ_LOG(5, (turn_sock->obj_name, "SO_SNDBUF set to %d",
                                   sobuf_size));
                    }
                }
            }

            /* Create active socket */
            pj_activesock_cfg_default(&asock_cfg);
            asock_cfg.grp_lock = turn_sock->grp_lock;

            pj_bzero(&asock_cb, sizeof(asock_cb));
            asock_cb.on_data_read = &on_data_read_asock;
            asock_cb.on_data_sent = &on_data_sent_asock;
            asock_cb.on_connect_complete = &on_connect_complete_asock;
            status = pj_activesock_create(turn_sock->pool, sock,
                                          sock_type, &asock_cfg,
                                          turn_sock->cfg.ioqueue, &asock_cb,
                                          turn_sock,
                                          &turn_sock->active_sock);                                                                                                                                                                                                                                                                             
            if (status != PJ_SUCCESS)
                pj_sock_close(sock);
        }
#if PJ_HAS_SSL_SOCK
        else {
            //TURN TLS
            pj_ssl_sock_param param, *ssock_param;

            ssock_param = &turn_sock->setting.tls_cfg.ssock_param;
            pj_ssl_sock_param_default(&param);

            pj_ssl_sock_param_copy(turn_sock->pool, &param, ssock_param);
            param.cb.on_connect_complete = &on_connect_complete_ssl_sock;
            param.cb.on_data_read = &on_data_read_ssl_sock;
            param.cb.on_data_sent = &on_data_sent_ssl_sock;
            param.ioqueue = turn_sock->cfg.ioqueue;
            param.timer_heap = turn_sock->cfg.timer_heap;
            param.grp_lock = turn_sock->grp_lock;
            param.server_name = turn_sock->server_name;
            param.user_data = turn_sock;
            param.sock_type = sock_type;
            param.sock_af = turn_sock->af;
            if (param.send_buffer_size < PJ_TURN_MAX_PKT_LEN)
                param.send_buffer_size = PJ_TURN_MAX_PKT_LEN;
            if (param.read_buffer_size < PJ_TURN_MAX_PKT_LEN)
                param.read_buffer_size = PJ_TURN_MAX_PKT_LEN;

            param.qos_type = turn_sock->setting.qos_type;
            param.qos_ignore_error = turn_sock->setting.qos_ignore_error;
            pj_memcpy(&param.qos_params, &turn_sock->setting.qos_params,
                      sizeof(param.qos_params));

            if (turn_sock->setting.tls_cfg.cert_file.slen ||
                turn_sock->setting.tls_cfg.ca_list_file.slen ||
                turn_sock->setting.tls_cfg.ca_list_path.slen ||
                turn_sock->setting.tls_cfg.privkey_file.slen)
            {
                status = pj_ssl_cert_load_from_files2(
                    turn_sock->pool,
                    &turn_sock->setting.tls_cfg.ca_list_file,
                    &turn_sock->setting.tls_cfg.ca_list_path,
                    &turn_sock->setting.tls_cfg.cert_file,
                    &turn_sock->setting.tls_cfg.privkey_file,
                    &turn_sock->setting.tls_cfg.password,
                    &turn_sock->cert);

            } else if (turn_sock->setting.tls_cfg.ca_buf.slen ||
                       turn_sock->setting.tls_cfg.cert_buf.slen ||
                       turn_sock->setting.tls_cfg.privkey_buf.slen)
            {
                status = pj_ssl_cert_load_from_buffer(
                    turn_sock->pool,
                    &turn_sock->setting.tls_cfg.ca_buf,
                    &turn_sock->setting.tls_cfg.cert_buf,
                    &turn_sock->setting.tls_cfg.privkey_buf,
                    &turn_sock->setting.tls_cfg.password,
                    &turn_sock->cert);
            }
            if (status != PJ_SUCCESS) {
                turn_sock_destroy(turn_sock, status);
                pj_grp_lock_release(turn_sock->grp_lock);
                return;
            }
            if (turn_sock->cert) {
                pj_turn_sock_tls_cfg_wipe_keys(&turn_sock->setting.tls_cfg);
            }

            status = pj_ssl_sock_create(turn_sock->pool, &param,
                                        &turn_sock->ssl_sock);

            if (status != PJ_SUCCESS) {
                turn_sock_destroy(turn_sock, status);
                pj_grp_lock_release(turn_sock->grp_lock);
                return;
            }

            if (turn_sock->cert) {
                status = pj_ssl_sock_set_certificate(turn_sock->ssl_sock,
                                                     turn_sock->pool,
                                                     turn_sock->cert);

                pj_ssl_cert_wipe_keys(turn_sock->cert);
                turn_sock->cert = NULL;
            }

        }
#endif

        if (status != PJ_SUCCESS) {
            turn_sock_destroy(turn_sock, status);
            pj_grp_lock_release(turn_sock->grp_lock);
            return;
        }

        PJ_LOG(5,(turn_sock->pool->obj_name,
                  "Connecting to %s", 
                  pj_sockaddr_print(&info.server, addrtxt, 
                                    sizeof(addrtxt), 3)));

        /* Initiate non-blocking connect */
        if (turn_sock->conn_type == PJ_TURN_TP_UDP) {
            status = PJ_SUCCESS;
        }
#if PJ_HAS_TCP
        else if (turn_sock->conn_type == PJ_TURN_TP_TCP) {
            status=pj_activesock_start_connect(
                                        turn_sock->active_sock, 
                                        turn_sock->pool,
                                        &info.server, 
                                        pj_sockaddr_get_len(&info.server));
        } 
#endif  
#if PJ_HAS_SSL_SOCK
        else if (turn_sock->conn_type == PJ_TURN_TP_TLS) {
            pj_ssl_start_connect_param connect_param;
            connect_param.pool = turn_sock->pool;
            connect_param.localaddr = &bound_addr;
            connect_param.local_port_range = turn_sock->setting.port_range;
            connect_param.remaddr = &info.server;
            connect_param.addr_len = pj_sockaddr_get_len(&info.server);

            status = pj_ssl_sock_start_connect2(turn_sock->ssl_sock,
                                                &connect_param);
        }
#endif
        if (status == PJ_SUCCESS) {
            on_connect_complete(turn_sock, PJ_SUCCESS);
        } else if (status != PJ_EPENDING) {
            PJ_PERROR(3, (turn_sock->pool->obj_name, status,
                          "Failed to connect to %s",
                          pj_sockaddr_print(&info.server, addrtxt,
                                            sizeof(addrtxt), 3)));
            turn_sock_destroy(turn_sock, status);
            pj_grp_lock_release(turn_sock->grp_lock);
            return;
        }

        /* Done for now. Subsequent work will be done in 
         * on_connect_complete() callback.
         */
    }

    if (new_state >= PJ_TURN_STATE_DESTROYING && turn_sock->sess) {
        pj_time_val delay = {0, 0};

        turn_sock->sess = NULL;
        pj_turn_session_set_user_data(sess, NULL);

        pj_timer_heap_cancel_if_active(turn_sock->cfg.timer_heap,
                                       &turn_sock->timer, 0);
        pj_timer_heap_schedule_w_grp_lock(turn_sock->cfg.timer_heap,
                                          &turn_sock->timer,
                                          &delay, TIMER_DESTROY,
                                          turn_sock->grp_lock);
    }

    pj_grp_lock_release(turn_sock->grp_lock);
}


static void dataconn_cleanup(tcp_data_conn_t *conn)
{
    if (conn->asock)
        pj_activesock_close(conn->asock);

    pj_pool_safe_release(&conn->pool);

    pj_bzero(conn, sizeof(*conn));
}

static pj_bool_t dataconn_on_data_read(pj_activesock_t *asock,
                                       void *data,
                                       pj_size_t size,
                                       pj_status_t status,
                                       pj_size_t *remainder)
{
    tcp_data_conn_t *conn = (tcp_data_conn_t*)
                            pj_activesock_get_user_data(asock);
    pj_turn_sock *turn_sock = conn->turn_sock;

    pj_grp_lock_acquire(turn_sock->grp_lock);

    if (size == 0 && status != PJ_SUCCESS) {
        /* Connection gone, release data connection */
        dataconn_cleanup(conn);
        --turn_sock->data_conn_cnt;
        pj_grp_lock_release(turn_sock->grp_lock);
        return PJ_FALSE;
    }

    *remainder = size;
    while (*remainder > 0) {
        if (conn->state == DATACONN_STATE_READY) {
            /* Application data */
            if (turn_sock->cb.on_rx_data) {
                (*turn_sock->cb.on_rx_data)(turn_sock, data, (unsigned)*remainder,
                                            &conn->peer_addr,
                                            conn->peer_addr_len);
            }
            *remainder = 0;
        } else if (conn->state == DATACONN_STATE_CONN_BINDING) {
            /* Waiting for ConnectionBind response */
            pj_bool_t is_stun;
            pj_turn_session_on_rx_pkt_param prm;

            /* Ignore if this is not a STUN message */
            is_stun = ((((pj_uint8_t*)data)[0] & 0xC0) == 0);
            if (!is_stun)
                goto on_return;

            pj_bzero(&prm, sizeof(prm));
            prm.pkt = data;
            prm.pkt_len = *remainder;
            prm.src_addr = &conn->peer_addr;
            prm.src_addr_len = conn->peer_addr_len;
            pj_turn_session_on_rx_pkt2(conn->turn_sock->sess, &prm);
            /* Got remainder? */
            if (prm.parsed_len < *remainder && prm.parsed_len > 0) {
                pj_memmove(data, (pj_uint8_t*)data + prm.parsed_len,
                           *remainder);
            }
            *remainder -= prm.parsed_len;
        } else
            goto on_return;
    }

on_return:
    pj_grp_lock_release(turn_sock->grp_lock);
    return PJ_TRUE;
}

static pj_bool_t dataconn_on_data_sent(pj_activesock_t *asock,
                                       pj_ioqueue_op_key_t *send_key,
                                       pj_ssize_t sent)
{
    tcp_data_conn_t *conn = (tcp_data_conn_t*)
                            pj_activesock_get_user_data(asock);
    pj_turn_sock *turn_sock = conn->turn_sock;

    return on_data_sent(turn_sock, send_key, sent);
}

static pj_bool_t dataconn_on_connect_complete(pj_activesock_t *asock,
                                              pj_status_t status)
{
    tcp_data_conn_t *conn = (tcp_data_conn_t*)
                            pj_activesock_get_user_data(asock);
    pj_turn_sock *turn_sock = conn->turn_sock;

    pj_grp_lock_acquire(turn_sock->grp_lock);

    if (status == PJ_SUCCESS) {
        status = pj_activesock_start_read(asock, turn_sock->pool,
                                          turn_sock->setting.max_pkt_size, 0);
    }
    if (status == PJ_SUCCESS) {
        conn->state = DATACONN_STATE_CONN_BINDING;
        status = pj_turn_session_connection_bind(turn_sock->sess,
                                                 conn->pool,
                                                 conn->id,
                                                 &conn->peer_addr,
                                                 conn->peer_addr_len);
    }
    if (status != PJ_SUCCESS) {
        dataconn_cleanup(conn);
        --turn_sock->data_conn_cnt;
        pj_grp_lock_release(turn_sock->grp_lock);
        return PJ_FALSE;
    }

    pj_grp_lock_release(turn_sock->grp_lock);
    return PJ_TRUE;
}


static void turn_on_connection_attempt(pj_turn_session *sess,
                                       pj_uint32_t conn_id,
                                       const pj_sockaddr_t *peer_addr,
                                       unsigned addr_len)
{
    pj_turn_sock *turn_sock = (pj_turn_sock*) 
                              pj_turn_session_get_user_data(sess);
    pj_pool_t *pool;
    tcp_data_conn_t *new_conn;
    pj_turn_session_info info;
    pj_sock_t sock = PJ_INVALID_SOCKET;
    pj_activesock_cfg asock_cfg;
    pj_activesock_cb asock_cb;
    pj_sockaddr bound_addr, *cfg_bind_addr;
    pj_uint16_t max_bind_retry;
    char addrtxt[PJ_INET6_ADDRSTRLEN+8];
    pj_status_t status;
    unsigned i;

    if (turn_sock == NULL) {
        /* We've been destroyed */
        return;
    }

    PJ_ASSERT_ON_FAIL(turn_sock->conn_type == PJ_TURN_TP_TCP &&
                      turn_sock->alloc_param.peer_conn_type == PJ_TURN_TP_TCP,
                      return);

    PJ_LOG(5,(turn_sock->pool->obj_name, "Connection attempt from peer %s",
              pj_sockaddr_print(peer_addr, addrtxt, sizeof(addrtxt), 3)));

    pj_grp_lock_acquire(turn_sock->grp_lock);

    if (turn_sock->data_conn_cnt == PJ_TURN_MAX_TCP_CONN_CNT) {
        /* Data connection has reached limit */
        pj_grp_lock_release(turn_sock->grp_lock);
        return;
    }

    /* Check if app wants to accept this connection */
    status = PJ_SUCCESS;
    if (turn_sock->cb.on_connection_attempt) {
        status = (*turn_sock->cb.on_connection_attempt)(turn_sock, conn_id,
                                                        peer_addr, addr_len);
    }
    /* App rejects it */
    if (status != PJ_SUCCESS) {
        pj_perror(4, turn_sock->pool->obj_name, status,
                  "Rejected connection attempt from peer %s",
                  pj_sockaddr_print(peer_addr, addrtxt, sizeof(addrtxt), 3));
        pj_grp_lock_release(turn_sock->grp_lock);
        return;
    }

    /* Find free data connection slot */
    for (i=0; i < PJ_TURN_MAX_TCP_CONN_CNT; ++i) {
        if (turn_sock->data_conn[i].state == DATACONN_STATE_NULL)
            break;
    }

    /* Verify that a free slot is found */
    pj_assert(i < PJ_TURN_MAX_TCP_CONN_CNT);
    ++turn_sock->data_conn_cnt;

    /* Init new data connection */
    new_conn = &turn_sock->data_conn[i];
    pj_bzero(new_conn, sizeof(*new_conn));
    pool = pj_pool_create(turn_sock->cfg.pf, "dataconn", 128, 128, NULL);
    new_conn->pool = pool;
    new_conn->id = conn_id;
    new_conn->turn_sock = turn_sock;
    pj_sockaddr_cp(&new_conn->peer_addr, peer_addr);
    new_conn->peer_addr_len = addr_len;
    pj_ioqueue_op_key_init(&new_conn->send_key, sizeof(new_conn->send_key));
    new_conn->state = DATACONN_STATE_INITSOCK;

    /* Init socket */
    status = pj_sock_socket(turn_sock->af, pj_SOCK_STREAM() | pj_SOCK_CLOEXEC(), 0, &sock);
    if (status != PJ_SUCCESS)
        goto on_return;

    /* Bind socket */
    cfg_bind_addr = &turn_sock->setting.bound_addr;
    max_bind_retry = MAX_BIND_RETRY;
    if (turn_sock->setting.port_range &&
        turn_sock->setting.port_range < max_bind_retry)
    {
        max_bind_retry = turn_sock->setting.port_range;
    }
    pj_sockaddr_init(turn_sock->af, &bound_addr, NULL, 0);
    if (cfg_bind_addr->addr.sa_family == pj_AF_INET() ||
        cfg_bind_addr->addr.sa_family == pj_AF_INET6())
    {
        pj_sockaddr_cp(&bound_addr, cfg_bind_addr);
    }
    status = pj_sock_bind_random(sock, &bound_addr,
                                 turn_sock->setting.port_range,
                                 max_bind_retry);
    if (status != PJ_SUCCESS)
        goto on_return;

    /* Apply socket buffer size */
    if (turn_sock->setting.so_rcvbuf_size > 0) {
        unsigned sobuf_size = turn_sock->setting.so_rcvbuf_size;
        status = pj_sock_setsockopt_sobuf(sock, pj_SO_RCVBUF(), PJ_TRUE,
                                          &sobuf_size);
        if (status != PJ_SUCCESS) {
            pj_perror(3, turn_sock->obj_name, status,
                      "Failed setting SO_RCVBUF");
        } else {
            if (sobuf_size < turn_sock->setting.so_rcvbuf_size) {
                PJ_LOG(4, (turn_sock->obj_name,
                           "Warning! Cannot set SO_RCVBUF as configured,"
                           " now=%d, configured=%d", sobuf_size,
                           turn_sock->setting.so_rcvbuf_size));
            } else {
                PJ_LOG(5, (turn_sock->obj_name, "SO_RCVBUF set to %d",
                           sobuf_size));
            }
        }
    }
    if (turn_sock->setting.so_sndbuf_size > 0) {
        unsigned sobuf_size = turn_sock->setting.so_sndbuf_size;
        status = pj_sock_setsockopt_sobuf(sock, pj_SO_SNDBUF(), PJ_TRUE,
                                          &sobuf_size);
        if (status != PJ_SUCCESS) {
            pj_perror(3, turn_sock->obj_name, status,
                      "Failed setting SO_SNDBUF");
        } else {
            if (sobuf_size < turn_sock->setting.so_sndbuf_size) {
                PJ_LOG(4, (turn_sock->obj_name,
                           "Warning! Cannot set SO_SNDBUF as configured,"
                           " now=%d, configured=%d", sobuf_size,
                           turn_sock->setting.so_sndbuf_size));
            } else {
                PJ_LOG(5, (turn_sock->obj_name, "SO_SNDBUF set to %d",
                           sobuf_size));
            }
        }
    }

    /* Create active socket */
    pj_activesock_cfg_default(&asock_cfg);
    asock_cfg.grp_lock = turn_sock->grp_lock;

    pj_bzero(&asock_cb, sizeof(asock_cb));
    asock_cb.on_data_read = &dataconn_on_data_read;
    asock_cb.on_data_sent = &dataconn_on_data_sent;
    asock_cb.on_connect_complete = &dataconn_on_connect_complete;
    status = pj_activesock_create(pool, sock,
                                  pj_SOCK_STREAM(), &asock_cfg,
                                  turn_sock->cfg.ioqueue, &asock_cb,
                                  new_conn, &new_conn->asock);
    if (status != PJ_SUCCESS)
        goto on_return;

    /* Connect to TURN server for data connection */
    pj_turn_session_get_info(turn_sock->sess, &info);
    status = pj_activesock_start_connect(new_conn->asock,
                                         pool,
                                         &info.server,
                                         pj_sockaddr_get_len(&info.server));
    if (status == PJ_SUCCESS) {
        dataconn_on_connect_complete(new_conn->asock, PJ_SUCCESS);
        pj_grp_lock_release(turn_sock->grp_lock);
        return;
    }

on_return:
    if (status == PJ_EPENDING) {
        PJ_LOG(5,(pool->obj_name,
                  "Accepting connection from peer %s",
                  pj_sockaddr_print(peer_addr, addrtxt, sizeof(addrtxt), 3)));
    } else {
        /* not PJ_SUCCESS */
        pj_perror(4, pool->obj_name, status,
                  "Failed in accepting connection from peer %s",
                  pj_sockaddr_print(peer_addr, addrtxt, sizeof(addrtxt), 3));

        if (!new_conn->asock && sock != PJ_INVALID_SOCKET)
            pj_sock_close(sock);    

        dataconn_cleanup(new_conn);
        --turn_sock->data_conn_cnt;

        /* Notify app for failure */
        if (turn_sock->cb.on_connection_status) {
            (*turn_sock->cb.on_connection_status)(turn_sock, status, conn_id,
                                                  peer_addr, addr_len);
        }
    }
    pj_grp_lock_release(turn_sock->grp_lock);
}

static void turn_on_connection_bind_status(pj_turn_session *sess,
                                           pj_status_t status,
                                           pj_uint32_t conn_id,
                                           const pj_sockaddr_t *peer_addr,
                                           unsigned addr_len)
{
    pj_turn_sock *turn_sock = (pj_turn_sock*) 
                              pj_turn_session_get_user_data(sess);
    tcp_data_conn_t *conn = NULL;
    unsigned i;

    pj_grp_lock_acquire(turn_sock->grp_lock);

    for (i=0; i < PJ_TURN_MAX_TCP_CONN_CNT; ++i) {
        tcp_data_conn_t *c = &turn_sock->data_conn[i];
        if (c->id == conn_id &&
            pj_sockaddr_cmp(peer_addr, &c->peer_addr) == 0)
        {
            conn = c;
            break;
        }
    }
    if (!conn) {
        PJ_LOG(5,(turn_sock->pool->obj_name,
                  "Warning: stray connection bind event"));
        pj_grp_lock_release(turn_sock->grp_lock);
        return;
    }

    if (status == PJ_SUCCESS) {
        conn->state = DATACONN_STATE_READY;
    } else {
        dataconn_cleanup(conn);
        --turn_sock->data_conn_cnt;
    }

    pj_grp_lock_release(turn_sock->grp_lock);

    if (turn_sock->cb.on_connection_status) {
        (*turn_sock->cb.on_connection_status)(turn_sock, status, conn_id,
                                              peer_addr, addr_len);
    }
}

static void turn_on_connect_complete(pj_turn_session *sess,
                                     pj_status_t status,
                                     pj_uint32_t conn_id,
                                     const pj_sockaddr_t *peer_addr,
                                     unsigned addr_len)
{
    pj_turn_sock *turn_sock = (pj_turn_sock*) 
                              pj_turn_session_get_user_data(sess);
    pj_pool_t *pool;
    tcp_data_conn_t *new_conn;
    pj_turn_session_info info;
    pj_sock_t sock = PJ_INVALID_SOCKET;
    pj_activesock_cfg asock_cfg;
    pj_activesock_cb asock_cb;
    pj_sockaddr bound_addr, *cfg_bind_addr;
    pj_uint16_t max_bind_retry;
    char addrtxt[PJ_INET6_ADDRSTRLEN+8];
    unsigned i;

    if (turn_sock == NULL) {
        /* We've been destroyed */
        return;
    }

    PJ_ASSERT_ON_FAIL(turn_sock->conn_type == PJ_TURN_TP_TCP &&
                      turn_sock->alloc_param.peer_conn_type == PJ_TURN_TP_TCP,
                      return);
    PJ_LOG(5,(turn_sock->pool->obj_name, "Trying to connect to peer %s",
              pj_sockaddr_print(peer_addr, addrtxt, sizeof(addrtxt), 3)));

    pj_grp_lock_acquire(turn_sock->grp_lock);

    if (turn_sock->data_conn_cnt == PJ_TURN_MAX_TCP_CONN_CNT) {
        /* Data connection has reached limit */

        status = PJ_ETOOMANY;
        pj_perror(4, turn_sock->pool->obj_name, status,
                  "Failed in connect to peer %s",
                  pj_sockaddr_print(peer_addr, addrtxt, sizeof(addrtxt), 3));

        /* Notify app for failure */
        if (turn_sock->cb.on_connection_status) {
            (*turn_sock->cb.on_connection_status)(turn_sock, status, conn_id,
                                                  peer_addr, addr_len);
        }

        pj_grp_lock_release(turn_sock->grp_lock);
        return;
    }

    /* Find free data connection slot */
    for (i=0; i < PJ_TURN_MAX_TCP_CONN_CNT; ++i) {
        if (turn_sock->data_conn[i].state == DATACONN_STATE_NULL)
            break;
    }

    /* Verify that a free slot is found */
    pj_assert(i < PJ_TURN_MAX_TCP_CONN_CNT);
    ++turn_sock->data_conn_cnt;

    /* Init new data connection */
    new_conn = &turn_sock->data_conn[i];
    pj_bzero(new_conn, sizeof(*new_conn));
    pool = pj_pool_create(turn_sock->cfg.pf, "dataconn", 128, 128, NULL);
    new_conn->pool = pool;
    new_conn->id = conn_id;
    new_conn->turn_sock = turn_sock;
    pj_sockaddr_cp(&new_conn->peer_addr, peer_addr);
    new_conn->peer_addr_len = addr_len;
    pj_ioqueue_op_key_init(&new_conn->send_key, sizeof(new_conn->send_key));
    new_conn->state = DATACONN_STATE_INITSOCK;

    /* Init socket */
    status = pj_sock_socket(turn_sock->af, pj_SOCK_STREAM() | pj_SOCK_CLOEXEC(), 0, &sock);
    if (status != PJ_SUCCESS)
        goto on_return;

    /* Bind socket */
    cfg_bind_addr = &turn_sock->setting.bound_addr;
    max_bind_retry = MAX_BIND_RETRY;
    if (turn_sock->setting.port_range &&
        turn_sock->setting.port_range < max_bind_retry)
    {
        max_bind_retry = turn_sock->setting.port_range;
    }
    pj_sockaddr_init(turn_sock->af, &bound_addr, NULL, 0);
    if (cfg_bind_addr->addr.sa_family == pj_AF_INET() ||
        cfg_bind_addr->addr.sa_family == pj_AF_INET6())
    {
        pj_sockaddr_cp(&bound_addr, cfg_bind_addr);
    }
    status = pj_sock_bind_random(sock, &bound_addr,
                                 turn_sock->setting.port_range,
                                 max_bind_retry);
    if (status != PJ_SUCCESS)
        goto on_return;

    /* Apply socket buffer size */
    if (turn_sock->setting.so_rcvbuf_size > 0) {
        unsigned sobuf_size = turn_sock->setting.so_rcvbuf_size;
        status = pj_sock_setsockopt_sobuf(sock, pj_SO_RCVBUF(), PJ_TRUE,
                                          &sobuf_size);
        if (status != PJ_SUCCESS) {
            pj_perror(3, turn_sock->obj_name, status,
                      "Failed setting SO_RCVBUF");
        } else {
            if (sobuf_size < turn_sock->setting.so_rcvbuf_size) {
                PJ_LOG(4, (turn_sock->obj_name,
                           "Warning! Cannot set SO_RCVBUF as configured,"
                           " now=%d, configured=%d", sobuf_size,
                           turn_sock->setting.so_rcvbuf_size));
            } else {
                PJ_LOG(5, (turn_sock->obj_name, "SO_RCVBUF set to %d",
                           sobuf_size));
            }
        }
    }
    if (turn_sock->setting.so_sndbuf_size > 0) {
        unsigned sobuf_size = turn_sock->setting.so_sndbuf_size;
        status = pj_sock_setsockopt_sobuf(sock, pj_SO_SNDBUF(), PJ_TRUE,
                                          &sobuf_size);
        if (status != PJ_SUCCESS) {
            pj_perror(3, turn_sock->obj_name, status,
                      "Failed setting SO_SNDBUF");
        } else {
            if (sobuf_size < turn_sock->setting.so_sndbuf_size) {
                PJ_LOG(4, (turn_sock->obj_name,
                           "Warning! Cannot set SO_SNDBUF as configured,"
                           " now=%d, configured=%d", sobuf_size,
                           turn_sock->setting.so_sndbuf_size));
            } else {
                PJ_LOG(5, (turn_sock->obj_name, "SO_SNDBUF set to %d",
                           sobuf_size));
            }
        }
    }

    /* Create active socket */
    pj_activesock_cfg_default(&asock_cfg);
    asock_cfg.grp_lock = turn_sock->grp_lock;

    pj_bzero(&asock_cb, sizeof(asock_cb));
    asock_cb.on_data_read = &dataconn_on_data_read;
    asock_cb.on_data_sent = &dataconn_on_data_sent;
    asock_cb.on_connect_complete = &dataconn_on_connect_complete;
    status = pj_activesock_create(pool, sock,
                                  pj_SOCK_STREAM(), &asock_cfg,
                                  turn_sock->cfg.ioqueue, &asock_cb,
                                  new_conn, &new_conn->asock);
    if (status != PJ_SUCCESS)
        goto on_return;

    /* Connect to TURN server for data connection */
    pj_turn_session_get_info(turn_sock->sess, &info);
    status = pj_activesock_start_connect(new_conn->asock,
                                         pool,
                                         &info.server,
                                         pj_sockaddr_get_len(&info.server));
    if (status == PJ_SUCCESS) {
        dataconn_on_connect_complete(new_conn->asock, PJ_SUCCESS);
        pj_grp_lock_release(turn_sock->grp_lock);
        return;
    }

on_return:
    if (status == PJ_EPENDING) {
        PJ_LOG(5,(pool->obj_name,
                  "Connecting to peer %s",
                  pj_sockaddr_print(peer_addr, addrtxt, sizeof(addrtxt), 3)));
    } else {
        /* not PJ_SUCCESS */
        pj_perror(4, pool->obj_name, status,
                  "Failed in connect to peer %s",
                  pj_sockaddr_print(peer_addr, addrtxt, sizeof(addrtxt), 3));

        if (!new_conn->asock && sock != PJ_INVALID_SOCKET)
            pj_sock_close(sock);    

        dataconn_cleanup(new_conn);
        --turn_sock->data_conn_cnt;

        /* Notify app for failure */
        if (turn_sock->cb.on_connection_status) {
            (*turn_sock->cb.on_connection_status)(turn_sock, status, conn_id,
                                                  peer_addr, addr_len);
        }
    }
    pj_grp_lock_release(turn_sock->grp_lock);
}
