nethelp.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 nethelp.c
 * @author Daniel Ferullo (ferullo@cmu.edu)
 *
 * @brief provides helpful basic network functions
 */
#include <pcap.h>
#include <string.h>
#include "nethelp.h"
#include "berkeleyapi.h"
#include "debug.h"

errorcode resolveIP(char *ip_or_name, ip_t *ip) {

        /* declare local variables */
        struct hostent *hp;

        /* error check arguments */
        CHECK_NOT_NULL(ip_or_name,ERROR_NULL_ARG_1);
        CHECK_NOT_NULL(ip,ERROR_NULL_ARG_2);

        /* do function */
        hp = gethostbyname(ip_or_name);

        if (hp==NULL)
                return ERROR_HOST_NAME_LOOKUP;

        if (hp->h_addr==NULL)
                return ERROR_1;

        memcpy(ip,hp->h_addr,sizeof(ip));
        if (*ip==-1)
                return ERROR_2;

        return SUCCESS;
}

errorcode bindSocket(port_t port_to_bind, sock_t *sd) {

        /* declare local variables */
        int buddy_sd;
        struct sockaddr_in server;

        /* error check arguments */
        CHECK_NOT_NULL(sd,ERROR_NULL_ARG_2);

        /* do function */

        /* create stream socket using TCP */
        if( (buddy_sd=socket(AF_INET, SOCK_STREAM, 0)) < 0 ) {
                return ERROR_SOCKET_CREATE;
        }

        /* put the clients info in the sockaddr_in struct */
        server.sin_family = AF_INET;
        server.sin_port = port_to_bind;
        server.sin_addr.s_addr = htonl(INADDR_ANY);

        /* bind the port to use for the direct connection*/
        if (bind(buddy_sd, (struct sockaddr*)&server, sizeof(server))<0) {
                DEBUG(DBG_NETWORK, "NETWORK:couldn't bind port %u\n",
                        DBG_PORT(port_to_bind));
                return ERROR_BIND;
        }
        /* done binding to port for direct connection */
        *sd = buddy_sd;

        return SUCCESS;
}

errorcode tcp_connect(ip_t ip, port_t port, sock_t *sd) {

        /* declare local variables */
        struct in_addr addr;
        struct sockaddr_in con_to;

        /* error check arguments */
        CHECK_NOT_NULL(sd,ERROR_NULL_ARG_3);

        /* do function */

        if (*sd <= 0) {
                DEBUG(DBG_ALL, "ALL:WARNING: tcp_connect: calling socket (bad b/c sd should already exist)\n");
                if ( (*sd=socket(AF_INET,SOCK_STREAM,0)) < 0)
                        return ERROR_TCP_SOCKET;
        }

        addr.s_addr = ip;

        con_to.sin_family = AF_INET;
        con_to.sin_port   = port;
        con_to.sin_addr   = addr;
        memset(con_to.sin_zero,0,8);

        if (connect(*sd, (struct sockaddr*)&con_to, sizeof(con_to))<0)
                return ERROR_TCP_CONNECT;

        return SUCCESS;
}

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