err_t
echo_poll(void *arg, struct tcp_pcb *tpcb)
{
err_t ret_err;
struct echo_state *es;
es = arg;
if (es != NULL)
{
if (es->p != NULL)
{
/* there is a remaining pbuf (chain) */
tcp_sent(tpcb, echo_sent);
echo_send(tpcb, es);
}
else
{
/* no remaining pbuf (chain) */
if(es->state == ES_CLOSING)
{
echo_close(tpcb, es);
}
}
ret_err = ERR_OK;
}
else
{
/* nothing to be done */
tcp_abort(tpcb);
ret_err = ERR_ABRT;
}
return ret_err;
}
err_t
echo_sent(void *arg, struct tcp_pcb *tpcb, u16_t len)
{
struct echo_state *es;
LWIP_UNUSED_ARG(len);
es = (struct echo_state *)arg;
es->retries = 0;
if(es->p != NULL)
{
/* still got pbufs to send */
tcp_sent(tpcb, echo_sent);
echo_send(tpcb, es);
}
else
{
/* no more pbufs to send */
if(es->state == ES_CLOSING)
{
echo_close(tpcb, es);
}
}
return ERR_OK;
}
void
echo_write(int fd, short revents, void *conn)
{
struct conn * c = (struct conn *) conn;
evbuffer_write(c->buf, fd);
printf("fd %d: wrote echo\n", fd);
echo_close(conn);
}
err_t
echo_recv(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err)
{
struct echo_state *es;
err_t ret_err;
LWIP_ASSERT("arg != NULL",arg != NULL);
es = arg;
if (p == NULL)
{
/* remote host closed connection */
es->state = ES_CLOSING;
if(es->p == NULL)
{
/* we're done sending, close it */
echo_close(tpcb, es);
}
else
{
/* we're not done yet */
tcp_sent(tpcb, echo_sent);
echo_send(tpcb, es);
}
ret_err = ERR_OK;
}
else if(err != ERR_OK)
{
/* cleanup, for unkown reason */
if (p != NULL)
{
es->p = NULL;
pbuf_free(p);
}
ret_err = err;
}
else if(es->state == ES_ACCEPTED)
{
/* first data chunk in p->payload */
es->state = ES_RECEIVED;
/* store reference to incoming pbuf (chain) */
es->p = p;
/* install send completion notifier */
tcp_sent(tpcb, echo_sent);
echo_send(tpcb, es);
ret_err = ERR_OK;
}
else if (es->state == ES_RECEIVED)
{
/* read some more data */
if(es->p == NULL)
{
es->p = p;
tcp_sent(tpcb, echo_sent);
echo_send(tpcb, es);
}
else
{
struct pbuf *ptr;
/* chain pbufs to the end of what we recv'ed previously */
ptr = es->p;
pbuf_chain(ptr,p);
}
ret_err = ERR_OK;
}
else if(es->state == ES_CLOSING)
{
/* odd case, remote side closing twice, trash data */
tcp_recved(tpcb, p->tot_len);
es->p = NULL;
pbuf_free(p);
ret_err = ERR_OK;
}
else
{
/* unkown es->state, trash data */
tcp_recved(tpcb, p->tot_len);
es->p = NULL;
pbuf_free(p);
ret_err = ERR_OK;
}
return ret_err;
}
