CODEWITHSUNDEEP
c++linuxsocketsudp
PersianGulf
PersianGulf

Reputation: 2935

printf network data

I wrote the following function and works fine:

int NetworkSocket::readDatagrams(unsigned char *buffer, string &srcAddress, unsigned short int & srcPort,size_t frameSize)
{

    unsigned int maximumPacketSize = sizeof(buffer);//frameSize ;
    int returnValue ;
    sockaddr_in from;
    socklen_t fromLength = sizeof( from );
    int receivedBytes;

    fromLength = sizeof(this->getSocketAddressStructureOfServer());
    receivedBytes = recvfrom( this->socketFD, buffer, maximumPacketSize, 0, (sockaddr *)&this->getSocketAddressStructureOfServer(), &fromLength     ) ;

    cout << receivedBytes << endl;
    returnValue = receivedBytes;
    if ( receivedBytes <= 0 )
        returnValue = -1;

    /// exporting data
    //
    srcAddress = inet_ntoa(this->getSocketAddressStructureOfServer().sin_addr);
    srcPort = ntohs( ( unsigned short int)this->getSocketAddressStructureOfServer().sin_port );


    return returnValue;
}

When i apply it, it return in ref srcAddress and port Even buffer is full, but i can't printf buffer, how i do it? wireshakr show 000010001 it means 5 bytes, and i need to examine it and compare to my data.

Upvotes: 0

Views: 164

Answers (1)

ATaylor
ATaylor

Reputation: 2598

unsigned int maximumPacketSize = sizeof(buffer);//frameSize ;

This line is faulty, since you're requesting the size of the pointer variable (which always equals '4' on a 32-bit system). You have to pass the maximum buffer size manually, or simply 'know' it, which shouldn't be a problem, since you instantiated it in the first place.

In the essence that means, you can never get more than 4 bytes.

Upvotes: 3

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