Question

I’m trying to get IP and Port of client, connected to the server socket. I pass the following function client socket file descriptor, but it returns 0.0.0.0:0
This drives me crazy, but sometimes it returns something like 248.127.0.0:24870…
What am I doing wrong?

PS returned address length is 16. Result returned by function is 0. No errors occur.

void    SocketServer::Log ( int socketFD , string message )
{
    struct sockaddr                     address;
    socklen_t                           addressLength;
    struct sockaddr_in*                 addressInternet;
    string                              ip;
    int                                 port;

    int result = getpeername ( socketFD , &address , &addressLength );
    cout << "Address length is " << addressLength << "     Return is " <<  result << "\n";
    addressInternet = (struct sockaddr_in*)&address;

    ip = inet_ntoa ( addressInternet->sin_addr );
    port = ntohs ( addressInternet->sin_port );

    cout << "Socket FD is " << socketFD << " " << ip << ":" << port << " " <<  message << "\n";
};

Answer 1

You forgot to set addressLength before calling getpeername. You need:

addressLength = sizeof(address);

As the documentation says:

The returned address is truncated if the buffer provided is too small