src/network/UDPClient.cxx

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/***************************************************************************
 *   Copyright (C) 2007 by Prabakaran Thirumalai   *
 *   praba_tuty@yahoo.com   *
 *                                                                         *
 *   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 <CSql.h>
#include <Network.h>

UDPClient::~UDPClient()
{
   if (isConnectedFlag) disconnect();
}
DbRetVal UDPClient::send(NetworkPacketType type, char *buf, int len)
{
    DbRetVal rv = OK;
    //printf("NW:UDP Send\n");
    void* totalBuffer = malloc(sizeof(PacketHeader)+ len);
    //PacketHeader *hdr= (PacketHeader*) totalBuffer;
    PacketHeader *hdr=  new PacketHeader();
    hdr->packetType = type;
    hdr->packetLength = len;
    hdr->srcNetworkID = networkid;
    hdr->version = 1;
    memcpy(((char*)totalBuffer) + sizeof(PacketHeader) , buf, len);

/*
    int numbytes =sendto(sockfd, totalBuffer, sizeof(PacketHeader)+ len, 0,
                (struct sockaddr *)&srvAddr, sizeof(struct sockaddr));

    if (numbytes== -1) {
        printError(ErrOS,"Unable to send the packet\n");
        return ErrOS;
    }
*/
    int numbytes=0;
    if ((numbytes=sendto(sockfd, hdr, sizeof(PacketHeader), 0,
           (struct sockaddr *)&srvAddr, sizeof(struct sockaddr))) == -1) {
        printError(ErrOS, "Unable to send the packet\n");
        return ErrOS;
    }
    //printf("Sent bytes %d\n", numbytes);
    if ((numbytes=sendto(sockfd, buf, len, 0,
           (struct sockaddr *)&srvAddr, sizeof(struct sockaddr))) == -1) {
        printError(ErrOS, "Unable to send the packet\n");
        return ErrOS;
    }
    //printf("Sent bytes %d\n", numbytes);
    free(totalBuffer);
    return rv;
    
}
DbRetVal UDPClient::receive()
{
    //TODO:: resoibse timeout during socket read
    DbRetVal rv = OK;
    fd_set fdset; //TODO::Move it to UDPClient class
    FD_ZERO(&fdset);
    FD_SET(sockfd, &fdset);
    struct timeval timeout;
    timeout.tv_sec = Conf::config.getNetworkResponseTimeout();
    timeout.tv_usec = 0;
    int ret = os::select(sockfd+1, &fdset, 0, 0, &timeout);
    if (ret <= 0) {
        printError(ErrPeerTimeOut,"Response timeout for peer site\n");
        return ErrPeerTimeOut;
    }

    int response =0;
    socklen_t len = sizeof(struct sockaddr);
    int numbytes = recvfrom(sockfd, &response, 4, 0,
                   (struct sockaddr *)&fromAddr, &len);
    if (numbytes !=4)
    {
       printf("Unable to receive response from peer\n");
       return ErrOS;
    }
    //printf("NW:UDP receive\n");
    if (response != 1) rv = ErrPeerResponse;
    if(srvAddr.sin_addr.s_addr != fromAddr.sin_addr.s_addr)
    {
        printf("Packet received from unknown source\n");
        rv = ErrPeerResponse;
    }
    //printf("Response rv %d\n", rv);
    return rv;
}
DbRetVal UDPClient::connect()
{
    printf("NW:UDP connect %s %d %d\n", hostName, port, networkid);

    //TODO::send endian to the peer site
    //do not do endian conversion here. it will be done at the server side
    DbRetVal rv = OK; 
    isConnectedFlag = false;
    struct hostent *he;
    int numbytes;
    if ((he=gethostbyname(hostName)) == NULL) { // get the host info
        printError(ErrOS,"Unable to get the peer host name\n");
        return ErrOS;
    }
    if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
        printError(ErrOS,"Unable to create socket to peer host name\n");
        return ErrOS;
    }
    srvAddr.sin_family = AF_INET; // host byte order
    srvAddr.sin_port = htons(port); // short, network byte order
    srvAddr.sin_addr = *((struct in_addr *)he->h_addr);
    memset(&(srvAddr.sin_zero), '\0', 8); // zero the rest of the struct
    printf("NW:UDP connecting\n");
    PacketHeader *hdr=  new PacketHeader();
    hdr->packetType = NW_PKT_CONNECT;
    hdr->packetLength = 0;
    hdr->srcNetworkID = 
    hdr->version = 1;
    if ((numbytes=sendto(sockfd, hdr, sizeof(PacketHeader), 0,
           (struct sockaddr *)&srvAddr, sizeof(struct sockaddr))) == -1) {
        printError(ErrOS, "Unable to send the packet\n");
        return ErrOS;
    }
    printf("Sent bytes %d\n", numbytes);

    fd_set fdset; 
    FD_ZERO(&fdset);
    FD_SET(sockfd, &fdset);
    struct timeval timeout;
    timeout.tv_sec = Conf::config.getNetworkConnectTimeout();
    timeout.tv_usec = 0;
    int ret = os::select(sockfd+1, &fdset, 0, 0, &timeout);
    if (ret <= 0) {
        printError(ErrPeerTimeOut,"Response timeout for peer site\n");
        return ErrPeerTimeOut;
    }

    int response =0;
    socklen_t len = sizeof(struct sockaddr);
    numbytes = recvfrom(sockfd, &response, 4, 0,
                   (struct sockaddr *)&fromAddr, &len);
    if (numbytes !=4)
    {
       printf("Unable to receive response from peer\n");
       return ErrOS;
    }
    if (response != 1) return ErrPeerResponse;
    isConnectedFlag = true;
    printf("NW:UDP connected\n");
    return OK;
}

DbRetVal UDPClient::disconnect()
{
    if (isConnectedFlag)
       printf("NW:UDP disconnect\n");

    isConnectedFlag = false;
    return OK;
}

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