valid_socket - protects the socket efunctions.
int valid_socket( object caller, string function,
mixed *info );
Each of the socket efunctions calls valid_socket() prior to executing.
If valid_socket returns 0, then the socket efunction fails. If
valid_socket returns 1, then the socket efunction attempts to succeed.
The first argument 'caller' is the object that called the socket efunc‐
tion. The second argument is the name of the socket efunction that is
being called (e.g. socket_write() or socket_bind()). The third argu‐
ment is an array of information. The first element of the array (when
applicable) is file descriptor being referenced. The second element of
the array is the owner of the socket (object). The third element of
the array is the address (string) of the remote end of the socket. The
fourth element of the array is the port number associated with the