natblaster_peer.c

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/*****************************************************************************
 * Copyright 2005 Daniel Ferullo                                             *
 *                                                                           *
 * Licensed under the Apache License, Version 2.0 (the "License");           *
 * you may not use this file except in compliance with the License.          *
 * You may obtain a copy of the License at                                   *
 *                                                                           *
 *    http://www.apache.org/licenses/LICENSE-2.0                             *
 *                                                                           *
 * Unless required by applicable law or agreed to in writing, software       *
 * distributed under the License is distributed on an "AS IS" BASIS,         *
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  *
 * See the License for the specific language governing permissions and       *
 * limitations under the License.                                            *
 *                                                                           *
 *****************************************************************************/

/**
 * @file natblaster_peer.c
 * @author Daniel Ferullo (ferullo@cmu.edu)
 *
 * @brief contains natblaster entrypoint for peer
 */

#include "natblaster_peer.h"

#include "debug.h"
#include "errorcodes.h"
#include "nethelp.h"
#include "peerdef.h"
#include "peerfsm.h"
#include "peercon.h"

int natblaster_connect(ip_t helper_ip, port_t helper_port, ip_t peer_ip,
                       port_t peer_port, ip_t buddy_ext_ip, ip_t buddy_int_ip,
                       port_t buddy_int_port, char *device, flag_t random) {

        peer_conn_info_t info;

        /* the return type is "int", but I return "errorcode"s because I know that
         * they are the same real type and that all the errorcodes are negative.
         * This makes debugging easier. */

        /* first find a device if needed */
        if (device==NULL)
                CHECK_FAILED(findDevice(&device),ERROR_NO_DEV_FOUND);

        DEBUG(DBG_VERBOSE, "VERBOSE:connecting to Buddy....%s:%uint\n",
                DBG_IP(buddy_int_ip), DBG_PORT(buddy_int_port));
        DEBUG(DBG_VERBOSE," %sext\n", DBG_IP(buddy_ext_ip));
        DEBUG(DBG_VERBOSE, "VERBOSE:from local address.....%s:%u\n",
                DBG_IP(peer_ip), DBG_PORT(peer_port));
        DEBUG(DBG_VERBOSE, "VERBOSE:with helper............%s:%u\n",
                DBG_IP(helper_ip), DBG_PORT(helper_port));
        DEBUG(DBG_VERBOSE, "VERBOSE:using Device...........%s\n",
                device);
        DEBUG(DBG_VERBOSE, "VERBOSE: this peer is %srandom\n",
                (random==FLAG_SET ? "" : "not "));

        /* now put the info in a conn_info structure */
        info.helper.ip                = helper_ip;
        info.helper.port              = helper_port;
        info.peer.ip                  = peer_ip;
        info.peer.port                = peer_port;
        info.peer.set                 = FLAG_SET;
        info.buddy.int_ip             = buddy_int_ip;
        info.buddy.int_port           = buddy_int_port;
        info.buddy.ext_ip             = buddy_ext_ip;
        info.buddy.identifier         = FLAG_SET;
        info.buddy.ext_port           = PORT_UNKNOWN;
        info.buddy.ext_port_set       =  FLAG_UNSET;
        info.socks.helper             = SOCKET_UNKNOWN;
        info.socks.helper_pred        = SOCKET_UNKNOWN;
        info.socks.buddy              = SOCKET_UNKNOWN;
        info.device                   = device;
        info.direct_conn_status       = FLAG_UNSET;
        info.bday.stop_synack_find    = FLAG_UNSET;
        /* buddy sock gets filled in below */

        /* bind the desired port for a connection to buddy */
        CHECK_FAILED(bindSocket(info.peer.port,&info.socks.buddy),ERROR_1);


        /* bind socket for helper connection (2 before buddy port); */
        if (random==FLAG_UNSET)
                info.helper_conn.persistent_port = PORT_ADD(peer_port,-2);
        else /* bind a "random" port (not the conventional port) */
                info.helper_conn.persistent_port = PORT_ADD(peer_port,-3);
        CHECK_FAILED(bindSocket(info.helper_conn.persistent_port,
                &info.socks.helper),ERROR_2);

        /* bind port for second helper connection */
        info.helper_conn.prediction_port = PORT_ADD(peer_port,-1);
        CHECK_FAILED(bindSocket(info.helper_conn.prediction_port,
                                &info.socks.helper_pred),ERROR_3);

        if (FAILED(peer_fsm_start(&info))) {
                /* close the sockets */
                close(info.socks.helper);
                close(info.socks.helper_pred);
                close(info.socks.buddy);
                return ERROR_4;
        }

        /* close helper sockets */
        close(info.socks.helper);
        close(info.socks.helper_pred);

        return info.socks.buddy;
}

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