source: mainline/uspace/srv/net/tcp/service.c@ 1d03e86

/*
 * Copyright (c) 2015 Jiri Svoboda
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup tcp
 * @{
 */

/**
 * @file HelenOS service implementation
 */

#include <async.h>
#include <errno.h>
#include <inet/endpoint.h>
#include <inet/inet.h>
#include <io/log.h>
#include <ipc/services.h>
#include <ipc/tcp.h>
#include <loc.h>
#include <macros.h>
#include <mem.h>
#include <stdlib.h>

#include "conn.h"
#include "service.h"
#include "tcp_type.h"
#include "ucall.h"

#define NAME "tcp"

/** Maximum amount of data transferred in one send call */
#define MAX_MSG_SIZE DATA_XFER_LIMIT

static void tcp_ev_data(tcp_cconn_t *);
static void tcp_ev_connected(tcp_cconn_t *);
static void tcp_ev_conn_failed(tcp_cconn_t *);
static void tcp_ev_conn_reset(tcp_cconn_t *);
static void tcp_ev_new_conn(tcp_clst_t *, tcp_cconn_t *);

static void tcp_service_cstate_change(tcp_conn_t *, void *, tcp_cstate_t);
static void tcp_service_recv_data(tcp_conn_t *, void *);
static void tcp_service_lst_cstate_change(tcp_conn_t *, void *, tcp_cstate_t);

static int tcp_cconn_create(tcp_client_t *, tcp_conn_t *, tcp_cconn_t **);

/** Connection callbacks to tie us to lower layer */
static tcp_cb_t tcp_service_cb = {
        .cstate_change = tcp_service_cstate_change,
        .recv_data = tcp_service_recv_data
};

/** Sentinel connection callbacks to tie us to lower layer */
static tcp_cb_t tcp_service_lst_cb = {
        .cstate_change = tcp_service_lst_cstate_change,
        .recv_data = NULL
};

/** Connection state has changed.
 *
 * @param conn      Connection
 * @param arg       Argument (not used)
 * @param old_state Previous connection state
 */
static void tcp_service_cstate_change(tcp_conn_t *conn, void *arg,
    tcp_cstate_t old_state)
{
        tcp_cstate_t nstate;
        tcp_cconn_t *cconn;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_service_cstate_change()");
        nstate = conn->cstate;
        cconn = tcp_uc_get_userptr(conn);

        if ((old_state == st_syn_sent || old_state == st_syn_received) &&
            (nstate == st_established)) {
                /* Connection established */
                tcp_ev_connected(cconn);
        }

        if (old_state != st_closed && nstate == st_closed && conn->reset) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_service_cstate_change: "
                    "Connection reset");
                /* Connection reset */
                tcp_ev_conn_reset(cconn);
        } else {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_service_cstate_change: "
                    "old_state=%d nstate=%d conn->reset=%d",
                    old_state, nstate, conn->reset);
        }

        /* XXX Failed to establish connection */
        if (0) tcp_ev_conn_failed(cconn);
}

/** Sentinel connection state has changed.
 *
 * @param conn      Connection
 * @param arg       Argument (not used)
 * @param old_state Previous connection state
 */
static void tcp_service_lst_cstate_change(tcp_conn_t *conn, void *arg,
    tcp_cstate_t old_state)
{
        tcp_cstate_t nstate;
        tcp_clst_t *clst;
        tcp_cconn_t *cconn;
        inet_ep2_t epp;
        int rc;
        tcp_error_t trc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_service_lst_cstate_change()");
        nstate = conn->cstate;
        clst = tcp_uc_get_userptr(conn);

        if ((old_state == st_syn_sent || old_state == st_syn_received) &&
            (nstate == st_established)) {
                /* Connection established */
                clst->conn = NULL;

                rc = tcp_cconn_create(clst->client, conn, &cconn);
                if (rc != EOK) {
                        /* XXX Could not create client connection */
                        return;
                }

                /* XXX Is there a race here (i.e. the connection is already active)? */
                tcp_uc_set_cb(conn, &tcp_service_cb, cconn);

                /* New incoming connection */
                tcp_ev_new_conn(clst, cconn);
        }

        if (old_state != st_closed && nstate == st_closed && conn->reset) {
                /* Connection reset */
                /* XXX */
        }

        /* XXX Failed to establish connection */
        if (0) {
                /* XXX */
        }

        /* Replenish sentinel connection */

        inet_ep2_init(&epp);
        epp.local = clst->elocal;

        trc = tcp_uc_open(&epp, ap_passive, tcp_open_nonblock,
            &conn);
        if (trc != TCP_EOK) {
                /* XXX Could not replenish connection */
                return;
        }

        conn->name = (char *) "s";
        clst->conn = conn;

        /* XXX Is there a race here (i.e. the connection is already active)? */
        tcp_uc_set_cb(conn, &tcp_service_lst_cb, clst);
}

/** Received data became available on connection.
 *
 * @param conn Connection
 * @param arg  Client connection
 */
static void tcp_service_recv_data(tcp_conn_t *conn, void *arg)
{
        tcp_cconn_t *cconn = (tcp_cconn_t *)arg;

        tcp_ev_data(cconn);
}

/** Send 'data' event to client.
 *
 * @param cconn Client connection
 */
static void tcp_ev_data(tcp_cconn_t *cconn)
{
        async_exch_t *exch;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_ev_data()");

        log_msg(LOG_DEFAULT, LVL_DEBUG, "client=%p\n", cconn->client);
        log_msg(LOG_DEFAULT, LVL_DEBUG, "sess=%p\n", cconn->client->sess);

        exch = async_exchange_begin(cconn->client->sess);
        aid_t req = async_send_1(exch, TCP_EV_DATA, cconn->id, NULL);
        async_exchange_end(exch);

        async_forget(req);
}

/** Send 'connected' event to client.
 *
 * @param cconn Client connection
 */
static void tcp_ev_connected(tcp_cconn_t *cconn)
{
        async_exch_t *exch;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_ev_connected()");

        exch = async_exchange_begin(cconn->client->sess);
        aid_t req = async_send_1(exch, TCP_EV_CONNECTED, cconn->id, NULL);
        async_exchange_end(exch);

        async_forget(req);
}

/** Send 'conn_failed' event to client.
 *
 * @param cconn Client connection
 */
static void tcp_ev_conn_failed(tcp_cconn_t *cconn)
{
        async_exch_t *exch;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_ev_conn_failed()");

        exch = async_exchange_begin(cconn->client->sess);
        aid_t req = async_send_1(exch, TCP_EV_CONN_FAILED, cconn->id, NULL);
        async_exchange_end(exch);

        async_forget(req);
}

/** Send 'conn_reset' event to client.
 *
 * @param cconn Client connection
 */
static void tcp_ev_conn_reset(tcp_cconn_t *cconn)
{
        async_exch_t *exch;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_ev_conn_reset()");

        exch = async_exchange_begin(cconn->client->sess);
        aid_t req = async_send_1(exch, TCP_EV_CONN_RESET, cconn->id, NULL);
        async_exchange_end(exch);

        async_forget(req);
}

/** Send 'new_conn' event to client.
 *
 * @param clst Client listener that received the connection
 * @param cconn New client connection
 */
static void tcp_ev_new_conn(tcp_clst_t *clst, tcp_cconn_t *cconn)
{
        async_exch_t *exch;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_ev_new_conn()");

        exch = async_exchange_begin(clst->client->sess);
        aid_t req = async_send_2(exch, TCP_EV_NEW_CONN, clst->id, cconn->id,
            NULL);
        async_exchange_end(exch);

        async_forget(req);
}

/** Create client connection.
 *
 * This effectively adds a connection into a client's namespace.
 *
 * @param client TCP client
 * @param conn   Connection
 * @param rcconn Place to store pointer to new client connection
 *
 * @return EOK on success or ENOMEM if out of memory
 */
static int tcp_cconn_create(tcp_client_t *client, tcp_conn_t *conn,
    tcp_cconn_t **rcconn)
{
        tcp_cconn_t *cconn;
        sysarg_t id;

        cconn = calloc(1, sizeof(tcp_cconn_t));
        if (cconn == NULL)
                return ENOMEM;

        /* Allocate new ID */
        id = 0;
        list_foreach (client->cconn, lclient, tcp_cconn_t, cconn) {
                if (cconn->id >= id)
                        id = cconn->id + 1;
        }

        cconn->id = id;
        cconn->client = client;
        cconn->conn = conn;

        list_append(&cconn->lclient, &client->cconn);
        *rcconn = cconn;
        return EOK;
}

/** Destroy client connection.
 *
 * @param cconn Client connection
 */
static void tcp_cconn_destroy(tcp_cconn_t *cconn)
{
        list_remove(&cconn->lclient);
        free(cconn);
}

/** Create client listener.
 *
 * Create client listener based on sentinel connection.
 * XXX Implement actual listener in protocol core
 *
 * @param client TCP client
 * @param conn   Sentinel connection
 * @param rclst  Place to store pointer to new client listener
 *
 * @return EOK on success or ENOMEM if out of memory
 */
static int tcp_clistener_create(tcp_client_t *client, tcp_conn_t *conn,
    tcp_clst_t **rclst)
{
        tcp_clst_t *clst;
        sysarg_t id;

        clst = calloc(1, sizeof(tcp_clst_t));
        if (clst == NULL)
                return ENOMEM;

        /* Allocate new ID */
        id = 0;
        list_foreach (client->clst, lclient, tcp_clst_t, clst) {
                if (clst->id >= id)
                        id = clst->id + 1;
        }

        clst->id = id;
        clst->client = client;
        clst->conn = conn;

        list_append(&clst->lclient, &client->clst);
        *rclst = clst;
        return EOK;
}

/** Destroy client listener.
 *
 * @param clst Client listener
 */
static void tcp_clistener_destroy(tcp_clst_t *clst)
{
        list_remove(&clst->lclient);
        free(clst);
}

/** Get client connection by ID.
 *
 * @param client Client
 * @param id     Client connection ID
 * @param rcconn Place to store pointer to client connection
 *
 * @return EOK on success, ENOENT if no client connection with the given ID
 *         is found.
 */
static int tcp_cconn_get(tcp_client_t *client, sysarg_t id,
    tcp_cconn_t **rcconn)
{
        list_foreach (client->cconn, lclient, tcp_cconn_t, cconn) {
                if (cconn->id == id) {
                        *rcconn = cconn;
                        return EOK;
                }
        }

        return ENOENT;
}

/** Get client listener by ID.
 *
 * @param client Client
 * @param id     Client connection ID
 * @param rclst  Place to store pointer to client listener
 *
 * @return EOK on success, ENOENT if no client listener with the given ID
 *         is found.
 */
static int tcp_clistener_get(tcp_client_t *client, sysarg_t id,
    tcp_clst_t **rclst)
{
        list_foreach (client->clst, lclient, tcp_clst_t, clst) {
                if (clst->id == id) {
                        *rclst = clst;
                        return EOK;
                }
        }

        return ENOENT;
}

/** Create connection.
 *
 * Handle client request to create connection (with parameters unmarshalled).
 *
 * @param client   TCP client
 * @param epp      Endpoint pair
 * @param rconn_id Place to store ID of new connection
 *
 * @return EOK on success or negative error code
 */
static int tcp_conn_create_impl(tcp_client_t *client, inet_ep2_t *epp,
    sysarg_t *rconn_id)
{
        tcp_conn_t *conn;
        tcp_cconn_t *cconn;
        int rc;
        tcp_error_t trc;
        char *slocal;
        char *sremote;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_create_impl");

        inet_addr_format(&epp->local.addr, &slocal);
        inet_addr_format(&epp->remote.addr, &sremote);
        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_create: local=%s remote=%s",
            slocal, sremote);
        free(slocal);
        free(sremote);

        trc = tcp_uc_open(epp, ap_active, tcp_open_nonblock, &conn);
        if (trc != TCP_EOK)
                return EIO;

        conn->name = (char *) "c";

        rc = tcp_cconn_create(client, conn, &cconn);
        if (rc != EOK) {
                assert(rc == ENOMEM);
                tcp_conn_delete(conn);
                return ENOMEM;
        }

        /* XXX Is there a race here (i.e. the connection is already active)? */
        tcp_uc_set_cb(conn, &tcp_service_cb, cconn);

        *rconn_id = cconn->id;
        return EOK;
}

/** Destroy connection.
 *
 * Handle client request to destroy connection (with parameters unmarshalled).
 *
 * @param client  TCP client
 * @param conn_id Connection ID
 * @return EOK on success, ENOENT if no such connection is found
 */
static int tcp_conn_destroy_impl(tcp_client_t *client, sysarg_t conn_id)
{
        tcp_cconn_t *cconn;
        int rc;

        rc = tcp_cconn_get(client, conn_id, &cconn);
        if (rc != EOK) {
                assert(rc == ENOENT);
                return ENOENT;
        }

        tcp_uc_close(cconn->conn);
        tcp_uc_delete(cconn->conn);
        tcp_cconn_destroy(cconn);
        return EOK;
}

/** Create listener.
 *
 * Handle client request to create listener (with parameters unmarshalled).
 *
 * @param client  TCP client
 * @param ep      Endpoint
 * @param rlst_id Place to store ID of new listener
 *
 * @return EOK on success or negative error code
*/
static int tcp_listener_create_impl(tcp_client_t *client, inet_ep_t *ep,
    sysarg_t *rlst_id)
{
        tcp_conn_t *conn;
        tcp_clst_t *clst;
        inet_ep2_t epp;
        int rc;
        tcp_error_t trc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_listener_create_impl");

        inet_ep2_init(&epp);
        epp.local.addr = ep->addr;
        epp.local.port = ep->port;

        trc = tcp_uc_open(&epp, ap_passive, tcp_open_nonblock, &conn);
        if (trc != TCP_EOK)
                return EIO;

        conn->name = (char *) "s";

        rc = tcp_clistener_create(client, conn, &clst);
        if (rc != EOK) {
                assert(rc == ENOMEM);
                tcp_conn_delete(conn);
                return ENOMEM;
        }

        clst->elocal = epp.local;

        /* XXX Is there a race here (i.e. the connection is already active)? */
        tcp_uc_set_cb(conn, &tcp_service_lst_cb, clst);

        *rlst_id = clst->id;
        return EOK;
}

/** Destroy listener.
 *
 * Handle client request to destroy listener (with parameters unmarshalled).
 *
 * @param client TCP client
 * @param lst_id Listener ID
 *
 * @return EOK on success, ENOENT if no such listener is found
 */
static int tcp_listener_destroy_impl(tcp_client_t *client, sysarg_t lst_id)
{
        tcp_clst_t *clst;
        int rc;

        rc = tcp_clistener_get(client, lst_id, &clst);
        if (rc != EOK) {
                assert(rc == ENOENT);
                return ENOENT;
        }

//      tcp_uc_close(cconn->conn);
        tcp_clistener_destroy(clst);
        return EOK;
}

/** Send FIN.
 *
 * Handle client request to send FIN (with parameters unmarshalled).
 *
 * @param client  TCP client
 * @param conn_id Connection ID
 *
 * @return EOK on success or negative error code
 */
static int tcp_conn_send_fin_impl(tcp_client_t *client, sysarg_t conn_id)
{
        tcp_cconn_t *cconn;
        int rc;

        rc = tcp_cconn_get(client, conn_id, &cconn);
        if (rc != EOK) {
                assert(rc == ENOENT);
                return ENOENT;
        }

        (void) cconn;
        /* XXX TODO */
        return EOK;
}

/** Push connection.
 *
 * Handle client request to push connection (with parameters unmarshalled).
 *
 * @param client  TCP client
 * @param conn_id Connection ID
 *
 * @return EOK on success or negative error code
 */
static int tcp_conn_push_impl(tcp_client_t *client, sysarg_t conn_id)
{
        tcp_cconn_t *cconn;
        int rc;

        rc = tcp_cconn_get(client, conn_id, &cconn);
        if (rc != EOK) {
                assert(rc == ENOENT);
                return ENOENT;
        }

        (void) cconn;
        /* XXX TODO */
        return EOK;
}

/** Reset connection.
 *
 * Handle client request to reset connection (with parameters unmarshalled).
 *
 * @param client  TCP client
 * @param conn_id Connection ID
 *
 * @return EOK on success or negative error code
 */
static int tcp_conn_reset_impl(tcp_client_t *client, sysarg_t conn_id)
{
        tcp_cconn_t *cconn;
        int rc;

        rc = tcp_cconn_get(client, conn_id, &cconn);
        if (rc != EOK) {
                assert(rc == ENOENT);
                return ENOENT;
        }

        tcp_uc_abort(cconn->conn);
        return EOK;
}

/** Send data over connection..
 *
 * Handle client request to send data (with parameters unmarshalled).
 *
 * @param client  TCP client
 * @param conn_id Connection ID
 * @param data    Data buffer
 * @param size    Data size in bytes
 *
 * @return EOK on success or negative error code
 */
static int tcp_conn_send_impl(tcp_client_t *client, sysarg_t conn_id,
    void *data, size_t size)
{
        tcp_cconn_t *cconn;
        int rc;

        rc = tcp_cconn_get(client, conn_id, &cconn);
        if (rc != EOK)
                return rc;

        rc = tcp_uc_send(cconn->conn, data, size, 0);
        if (rc != EOK)
                return rc;

        return EOK;
}

/** Receive data from connection.
 *
 * Handle client request to receive data (with parameters unmarshalled).
 *
 * @param client  TCP client
 * @param conn_id Connection ID
 * @param data    Data buffer
 * @param size    Buffer size in bytes
 * @param nrecv   Place to store actual number of bytes received
 *
 * @return EOK on success or negative error code
 */
static int tcp_conn_recv_impl(tcp_client_t *client, sysarg_t conn_id,
    void *data, size_t size, size_t *nrecv)
{
        tcp_cconn_t *cconn;
        xflags_t xflags;
        int rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_impl()");

        rc = tcp_cconn_get(client, conn_id, &cconn);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_impl() - conn not found");
                return rc;
        }

        rc = tcp_uc_receive(cconn->conn, data, size, nrecv, &xflags);
        if (rc != EOK) {
                switch (rc) {
                case TCP_EAGAIN:
                        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_impl() - EAGAIN");
                        return EAGAIN;
                default:
                        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_impl() - trc=%d", rc);
                        return EIO;
                }
        }

        return EOK;
}

/** Create client callback session.
 *
 * Handle client request to create callback session.
 *
 * @param client  TCP client
 * @param iid     Async request ID
 * @param icall   Async request data
 */
static void tcp_callback_create_srv(tcp_client_t *client, ipc_callid_t iid,
    ipc_call_t *icall)
{
        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_callback_create_srv()");

        async_sess_t *sess = async_callback_receive(EXCHANGE_SERIALIZE);
        if (sess == NULL) {
                async_answer_0(iid, ENOMEM);
                return;
        }

        client->sess = sess;
        async_answer_0(iid, EOK);
}

/** Create connection.
 *
 * Handle client request to create connection.
 *
 * @param client   TCP client
 * @param iid      Async request ID
 * @param icall    Async request data
 */
static void tcp_conn_create_srv(tcp_client_t *client, ipc_callid_t iid,
    ipc_call_t *icall)
{
        ipc_callid_t callid;
        size_t size;
        inet_ep2_t epp;
        sysarg_t conn_id;
        int rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_create_srv()");

        if (!async_data_write_receive(&callid, &size)) {
                async_answer_0(callid, EREFUSED);
                async_answer_0(iid, EREFUSED);
                return;
        }

        if (size != sizeof(inet_ep2_t)) {
                async_answer_0(callid, EINVAL);
                async_answer_0(iid, EINVAL);
                return;
        }

        rc = async_data_write_finalize(callid, &epp, size);
        if (rc != EOK) {
                async_answer_0(callid, rc);
                async_answer_0(iid, rc);
                return;
        }

        rc = tcp_conn_create_impl(client, &epp, &conn_id);
        if (rc != EOK) {
                async_answer_0(iid, rc);
                return;
        }

        async_answer_1(iid, EOK, conn_id);
}

/** Destroy connection.
 *
 * Handle client request to destroy connection.
 *
 * @param client   TCP client
 * @param iid      Async request ID
 * @param icall    Async request data
 */
static void tcp_conn_destroy_srv(tcp_client_t *client, ipc_callid_t iid,
    ipc_call_t *icall)
{
        sysarg_t conn_id;
        int rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_destroy_srv()");

        conn_id = IPC_GET_ARG1(*icall);
        rc = tcp_conn_destroy_impl(client, conn_id);
        async_answer_0(iid, rc);
}

/** Create listener.
 *
 * Handle client request to create listener.
 *
 * @param client   TCP client
 * @param iid      Async request ID
 * @param icall    Async request data
 */
static void tcp_listener_create_srv(tcp_client_t *client, ipc_callid_t iid,
    ipc_call_t *icall)
{
        ipc_callid_t callid;
        size_t size;
        inet_ep_t ep;
        sysarg_t lst_id;
        int rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_listener_create_srv()");

        if (!async_data_write_receive(&callid, &size)) {
                async_answer_0(callid, EREFUSED);
                async_answer_0(iid, EREFUSED);
                return;
        }

        if (size != sizeof(inet_ep_t)) {
                async_answer_0(callid, EINVAL);
                async_answer_0(iid, EINVAL);
                return;
        }

        rc = async_data_write_finalize(callid, &ep, size);
        if (rc != EOK) {
                async_answer_0(callid, rc);
                async_answer_0(iid, rc);
                return;
        }

        rc = tcp_listener_create_impl(client, &ep, &lst_id);
        if (rc != EOK) {
                async_answer_0(iid, rc);
                return;
        }

        async_answer_1(iid, EOK, lst_id);
}

/** Destroy listener.
 *
 * Handle client request to destroy listener.
 *
 * @param client   TCP client
 * @param iid      Async request ID
 * @param icall    Async request data
 */
static void tcp_listener_destroy_srv(tcp_client_t *client, ipc_callid_t iid,
    ipc_call_t *icall)
{
        sysarg_t lst_id;
        int rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_listener_destroy_srv()");

        lst_id = IPC_GET_ARG1(*icall);
        rc = tcp_listener_destroy_impl(client, lst_id);
        async_answer_0(iid, rc);
}

/** Send FIN.
 *
 * Handle client request to send FIN.
 *
 * @param client   TCP client
 * @param iid      Async request ID
 * @param icall    Async request data
 */
static void tcp_conn_send_fin_srv(tcp_client_t *client, ipc_callid_t iid,
    ipc_call_t *icall)
{
        sysarg_t conn_id;
        int rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_send_fin_srv()");

        conn_id = IPC_GET_ARG1(*icall);
        rc = tcp_conn_send_fin_impl(client, conn_id);
        async_answer_0(iid, rc);
}

/** Push connection.
 *
 * Handle client request to push connection.
 *
 * @param client   TCP client
 * @param iid      Async request ID
 * @param icall    Async request data
 */
static void tcp_conn_push_srv(tcp_client_t *client, ipc_callid_t iid,
    ipc_call_t *icall)
{
        sysarg_t conn_id;
        int rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_push_srv()");

        conn_id = IPC_GET_ARG1(*icall);
        rc = tcp_conn_push_impl(client, conn_id);
        async_answer_0(iid, rc);
}

/** Reset connection.
 *
 * Handle client request to reset connection.
 *
 * @param client   TCP client
 * @param iid      Async request ID
 * @param icall    Async request data
 */
static void tcp_conn_reset_srv(tcp_client_t *client, ipc_callid_t iid,
    ipc_call_t *icall)
{
        sysarg_t conn_id;
        int rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_reset_srv()");

        conn_id = IPC_GET_ARG1(*icall);
        rc = tcp_conn_reset_impl(client, conn_id);
        async_answer_0(iid, rc);
}

/** Send data via connection..
 *
 * Handle client request to send data via connection.
 *
 * @param client   TCP client
 * @param iid      Async request ID
 * @param icall    Async request data
 */
static void tcp_conn_send_srv(tcp_client_t *client, ipc_callid_t iid,
    ipc_call_t *icall)
{
        ipc_callid_t callid;
        size_t size;
        sysarg_t conn_id;
        void *data;
        int rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_send_srv())");

        /* Receive message data */

        if (!async_data_write_receive(&callid, &size)) {
                async_answer_0(callid, EREFUSED);
                async_answer_0(iid, EREFUSED);
                return;
        }

        if (size > MAX_MSG_SIZE) {
                async_answer_0(callid, EINVAL);
                async_answer_0(iid, EINVAL);
                return;
        }

        data = malloc(size);
        if (data == NULL) {
                async_answer_0(callid, ENOMEM);
                async_answer_0(iid, ENOMEM);
        }

        rc = async_data_write_finalize(callid, data, size);
        if (rc != EOK) {
                async_answer_0(callid, rc);
                async_answer_0(iid, rc);
                free(data);
                return;
        }

        conn_id = IPC_GET_ARG1(*icall);

        rc = tcp_conn_send_impl(client, conn_id, data, size);
        if (rc != EOK) {
                async_answer_0(iid, rc);
                free(data);
                return;
        }

        async_answer_0(iid, EOK);
        free(data);
}

/** Read received data from connection without blocking.
 *
 * Handle client request to read received data via connection without blocking.
 *
 * @param client   TCP client
 * @param iid      Async request ID
 * @param icall    Async request data
 */
static void tcp_conn_recv_srv(tcp_client_t *client, ipc_callid_t iid,
    ipc_call_t *icall)
{
        ipc_callid_t callid;
        sysarg_t conn_id;
        size_t size, rsize;
        void *data;
        int rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_srv()");

        conn_id = IPC_GET_ARG1(*icall);

        if (!async_data_read_receive(&callid, &size)) {
                async_answer_0(callid, EREFUSED);
                async_answer_0(iid, EREFUSED);
                return;
        }

        size = min(size, 16384);
        data = malloc(size);
        if (data == NULL) {
                async_answer_0(callid, ENOMEM);
                async_answer_0(iid, ENOMEM);
                return;
        }

        rc = tcp_conn_recv_impl(client, conn_id, data, size, &rsize);
        if (rc != EOK) {
                async_answer_0(callid, rc);
                async_answer_0(iid, rc);
                free(data);
                return;
        }

        rc = async_data_read_finalize(callid, data, size);
        if (rc != EOK) {
                async_answer_0(iid, rc);
                free(data);
                return;
        }

        async_answer_1(iid, EOK, rsize);
        free(data);

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_srv(): OK");
}

/** Read received data from connection with blocking.
 *
 * Handle client request to read received data via connection with blocking.
 *
 * @param client   TCP client
 * @param iid      Async request ID
 * @param icall    Async request data
 */
static void tcp_conn_recv_wait_srv(tcp_client_t *client, ipc_callid_t iid,
    ipc_call_t *icall)
{
        ipc_callid_t callid;
        sysarg_t conn_id;
        size_t size, rsize;
        void *data;
        int rc;

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_wait_srv()");

        conn_id = IPC_GET_ARG1(*icall);

        if (!async_data_read_receive(&callid, &size)) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_wait_srv - data_receive failed");
                async_answer_0(callid, EREFUSED);
                async_answer_0(iid, EREFUSED);
                return;
        }

        size = min(size, 16384);
        data = malloc(size);
        if (data == NULL) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_wait_srv - allocation failed");
                async_answer_0(callid, ENOMEM);
                async_answer_0(iid, ENOMEM);
                return;
        }

        rc = tcp_conn_recv_impl(client, conn_id, data, size, &rsize);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_wait_srv - recv_impl failed rc=%d", rc);
                async_answer_0(callid, rc);
                async_answer_0(iid, rc);
                free(data);
                return;
        }

        rc = async_data_read_finalize(callid, data, size);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_wait_srv - finalize failed");
                async_answer_0(iid, rc);
                free(data);
                return;
        }

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_wait_srv(): rsize=%zu", size);
        async_answer_1(iid, EOK, rsize);
        free(data);

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_conn_recv_wait_srv(): OK");
}

/** Initialize TCP client structure.
 *
 * @param client TCP client
 */
static void tcp_client_init(tcp_client_t *client)
{
        memset(client, 0, sizeof(tcp_client_t));
        client->sess = NULL;
        list_initialize(&client->cconn);
        list_initialize(&client->clst);
}

/** Finalize TCP client structure.
 *
 * @param client TCP client
 */
static void tcp_client_fini(tcp_client_t *client)
{
        tcp_cconn_t *cconn;
        unsigned long n;

        n = list_count(&client->cconn);
        if (n != 0) {
                log_msg(LOG_DEFAULT, LVL_WARN, "Client with %lu active "
                    "connections closed session", n);

                while (!list_empty(&client->cconn)) {
                        cconn = list_get_instance(list_first(&client->cconn),
                            tcp_cconn_t, lclient);
                        tcp_uc_close(cconn->conn);
                        tcp_uc_delete(cconn->conn);
                        tcp_cconn_destroy(cconn);
                }
        }

        n = list_count(&client->clst);
        if (n != 0) {
                log_msg(LOG_DEFAULT, LVL_WARN, "Client with %lu active "
                    "listeners closed session", n);
                /* XXX Destroy listeners */
        }

        if (client->sess != NULL)
                async_hangup(client->sess);
}

/** Handle TCP client connection.
 *
 * @param iid   Connect call ID
 * @param icall Connect call data
 * @param arg   Connection argument
 */
static void tcp_client_conn(ipc_callid_t iid, ipc_call_t *icall, void *arg)
{
        tcp_client_t client;

        /* Accept the connection */
        async_answer_0(iid, EOK);

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_client_conn() - client=%p",
            &client);

        tcp_client_init(&client);

        while (true) {
                log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_client_conn: wait req");
                ipc_call_t call;
                ipc_callid_t callid = async_get_call(&call);
                sysarg_t method = IPC_GET_IMETHOD(call);

                log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_client_conn: method=%d",
                    (int)method);
                if (!method) {
                        /* The other side has hung up */
                        async_answer_0(callid, EOK);
                        break;
                }

                switch (method) {
                case TCP_CALLBACK_CREATE:
                        tcp_callback_create_srv(&client, callid, &call);
                        break;
                case TCP_CONN_CREATE:
                        tcp_conn_create_srv(&client, callid, &call);
                        break;
                case TCP_CONN_DESTROY:
                        tcp_conn_destroy_srv(&client, callid, &call);
                        break;
                case TCP_LISTENER_CREATE:
                        tcp_listener_create_srv(&client, callid, &call);
                        break;
                case TCP_LISTENER_DESTROY:
                        tcp_listener_destroy_srv(&client, callid, &call);
                        break;
                case TCP_CONN_SEND_FIN:
                        tcp_conn_send_fin_srv(&client, callid, &call);
                        break;
                case TCP_CONN_PUSH:
                        tcp_conn_push_srv(&client, callid, &call);
                        break;
                case TCP_CONN_RESET:
                        tcp_conn_reset_srv(&client, callid, &call);
                        break;
                case TCP_CONN_SEND:
                        tcp_conn_send_srv(&client, callid, &call);
                        break;
                case TCP_CONN_RECV:
                        tcp_conn_recv_srv(&client, callid, &call);
                        break;
                case TCP_CONN_RECV_WAIT:
                        tcp_conn_recv_wait_srv(&client, callid, &call);
                        break;
                default:
                        async_answer_0(callid, ENOTSUP);
                        break;
                }
        }

        log_msg(LOG_DEFAULT, LVL_DEBUG, "tcp_client_conn TERMINATED");
        tcp_client_fini(&client);
}

/** Initialize TCP service.
 *
 * @return EOK on success or negative error code.
 */
int tcp_service_init(void)
{
        int rc;
        service_id_t sid;

        async_set_fallback_port_handler(tcp_client_conn, NULL);

        rc = loc_server_register(NAME);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed registering server.");
                return EIO;
        }

        rc = loc_service_register(SERVICE_NAME_TCP, &sid);
        if (rc != EOK) {
                log_msg(LOG_DEFAULT, LVL_ERROR, "Failed registering service.");
                return EIO;
        }

        return EOK;
}

/**
 * @}
 */