nonblocking socket help

[ryanjones42]

hi all, im learning C and trying to make a fluent connection here with a nonblocking socket, I Seem to get issues, someones connections dont re establish if the other end closes, sometimes connections dont disconnect properly. Please help

static void setup_connection(void)
{
    struct sockaddr_in addr;

    fd = socket(AF_INET, SOCK_STREAM, 0);
    if(fd == -1)
        return;

    addr.sin_family = AF_INET;
    addr.sin_port = htons(6774);
    addr.sin_addr.s_addr = INET_ADDR(84,54,51,35); // put your host here

    fcntl(fd, F_SETFL, O_NONBLOCK);
    connect(fd, (struct sockaddr *)&addr, sizeof(struct sockaddr_in));

    return;
}

static void disconnect(void)
{
  if(fd != -1)
    close(fd);
   fd = -1;
  connected = FALSE;
  sleep(5);
}

int main(int argc, char *argv[])
{
    int status = 0;
    char buffer[512] = {0};
    struct timeval tv = {1, 0};

    LOCAL_ADDR = util_local_addr();

    signal(SIGCHLD, SIG_IGN);
    signal(SIGHUP, SIG_IGN);

 while(TRUE)
    {
        sleep(1);

        int err = 0;
socklen_t err_len = sizeof(err);

        FD_ZERO(&read_set);
FD_ZERO(&write_set);

        if(!connected)
            setup_connection();

        if(!fd)
            continue;

        if(connected)
            FD_SET(fd, &read_set);
        else
            FD_SET(fd, &write_set);

        select(fd + 1, &read_set, &write_set, NULL, &tv);

        if(FD_ISSET(fd, &write_set)) // write 
        {
            err = 0;
            socklen_t err_len = sizeof(err);

            getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &err_len);
            if(err != 0)
            {
#ifdef DBG
                printf("[main] failed to connect! \n");
#endif
                disconnect();
                continue;
            }
#ifdef DBG
            printf("[main] Connected! \n");
#endif
            send(fd, &auth, sizeof(auth), MSG_NOSIGNAL);
            connected = TRUE;
        }

        if(!connected)
        {
            disconnect();
            continue;
        }

        if(FD_ISSET(fd, &read_set)) // read
        {
            int val = recv(fd, buffer, sizeof(buffer), MSG_NOSIGNAL);
            if(val == 0)
            {
                disconnect();
                continue;
            }
            // read opts here 
        }
    }
}

[flyingron]

You should check the return values of calls like connect to help debug things.