err_t EthernetClient::do_poll(void *arg, struct tcp_pcb *cpcb)
{
EthernetClient *client = static_cast<EthernetClient*>(arg);
if(client->_connected) {
if(cpcb->keep_cnt_sent++ > 4) {
cpcb->keep_cnt_sent = 0;
/* Stop polling */
tcp_poll(cpcb, NULL, 0);
tcp_abort(cpcb);
return ERR_OK;
}
/* Send tcp keep alive probe */
tcp_keepalive(cpcb);
return ERR_OK;
}
/* We only end up here if the connection failed to close
* in an earlier call to tcp_close */
err_t err = tcp_close(cpcb);
if (err != ERR_OK) {
/* error closing, try again later in poll (every 2 sec) */
tcp_poll(cpcb, do_poll, 4);
return err;
}
return err;
}
static int _tcp_keepalive(lua_State *L)
{
int fd = luaL_checkint(L, 1);
int keep_alive = lua_toboolean(L, 2);
int ret = tcp_keepalive(fd, keep_alive);
lua_pushinteger(L, ret);
return 1;
}
