Reading TCP_NODELAY using getsockopt returning a weird value

I am trying to verifying that my setting of TCP_NODELAY is working by reading it back after I set it.

Im setting the value to '1', but when I read it back, its set to '4'. Im afraid im doing something wrong.

Heres my code:

    int tcpBefore;
    socklen_t tcpBeforeLen = sizeof(tcpBefore);
    int res = getsockopt(socket, IPPROTO_TCP, TCP_NODELAY, &tcpBefore, &tcpBeforeLen);

    // Turn on TCP no delay
    int tcpNoDelay = 1;
    res = setsockopt(socket, IPPROTO_TCP, TCP_NODELAY, (void *)&tcpNoDelay, sizeof(tcpNoDelay));

    int tcpAfter;
    socklen_t tcpAfterLen = sizeof(tcpAfter);
    res = getsockopt(socket, IPPROTO_TCP, TCP_NODELAY, &tcpAfter, &tcpAfterLen);

The value I get for 'tcpBefore' is '0'. The value I get after I set it is '4'. This seems odd.

Is there something I am doing wrong?

via Chebli Mohamed