metalsvm/apps/echo.c

/*
 * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Adam Dunkels <adam@sics.se>
 *
 */

#include <metalsvm/stdio.h>

#include "tests.h"

#if defined(CONFIG_LWIP) && defined(START_ECHO)

#include <lwip/opt.h>

#if LWIP_NETCONN

#include <lwip/sys.h>
#include <lwip/api.h>

/*-----------------------------------------------------------------------------------*/
static void
tcpecho_thread(void *arg)
{
	struct netconn *conn, *newconn;
	err_t           err;
	LWIP_UNUSED_ARG(arg);

	/* Create a new connection identifier. */
	conn = netconn_new(NETCONN_TCP);

	/* Bind connection to well known port number 7. */
	netconn_bind(conn, NULL, 7);

	/* Tell connection to go into listening mode. */
	netconn_listen(conn);

	while (1) {

		/* Grab new connection. */
		err = netconn_accept(conn, &newconn);
		/* kprintf("accepted new connection %p\n", newconn); */
		/* Process the new connection. */
		if (err == ERR_OK) {
			struct netbuf  *buf;
			void           *data;
			u16_t           len;

			while ((err = netconn_recv(newconn, &buf)) == ERR_OK) {
				/* kprintf("Recved\n"); */
				do {
					netbuf_data(buf, &data, &len);
					err = netconn_write(newconn, data, len, NETCONN_COPY);
#if 0
					if (err != ERR_OK) {
						kprintf("tcpecho: netconn_write: error \"%s\"\n", lwip_strerr(err));
					}
#endif
				} while (netbuf_next(buf) >= 0);
				netbuf_delete(buf);
			}
			/* kprintf("Got EOF, looping\n"); */
			/*
			 * Close connection and discard connection
			 * identifier.
			 */
			netconn_close(newconn);
			netconn_delete(newconn);
		}
	}
}

/*-----------------------------------------------------------------------------------*/
void
echo_init(void)
{
	sys_thread_new("tcpecho_thread", tcpecho_thread, NULL, DEFAULT_THREAD_STACKSIZE, DEFAULT_THREAD_PRIO);
}
/*-----------------------------------------------------------------------------------*/

#else

#include <lwip/debug.h>
#include <lwip/stats.h>
#include <lwip/tcp.h>

/*
 * TCP echo server example using raw API.
 *
 * Echos all bytes sent by connecting client,
 * and passively closes when client is done.
 *
 */


static struct tcp_pcb *echo_pcb;

enum echo_states
{
	ES_NONE = 0,
	ES_ACCEPTED,
	ES_RECEIVED,
	ES_CLOSING
};

struct echo_state
{
	u8_t state;
	u8_t retries;
	struct tcp_pcb *pcb;
	/* pbuf (chain) to recycle */
	struct pbuf *p;
};

static err_t echo_accept(void *arg, struct tcp_pcb *newpcb, err_t err);
static err_t echo_recv(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err);
static void echo_error(void *arg, err_t err);
static err_t echo_poll(void *arg, struct tcp_pcb *tpcb);
static err_t echo_sent(void *arg, struct tcp_pcb *tpcb, u16_t len);
static void echo_send(struct tcp_pcb *tpcb, struct echo_state *es);
static void echo_close(struct tcp_pcb *tpcb, struct echo_state *es);

void
echo_init(void)
{
	echo_pcb = tcp_new();
	if (echo_pcb != NULL)
	{
		err_t err;

		err = tcp_bind(echo_pcb, IP_ADDR_ANY, 7);
		if (err == ERR_OK)
		{
			echo_pcb = tcp_listen(echo_pcb);
			tcp_accept(echo_pcb, echo_accept);
		} else  {
			/* abort? output diagnostic? */
		}
	} else {
		/* abort? output diagnostic? */
	}
}

static err_t
echo_accept(void *arg, struct tcp_pcb *newpcb, err_t err)
{
	err_t ret_err;
	struct echo_state *es;

	LWIP_UNUSED_ARG(arg);
	LWIP_UNUSED_ARG(err);

	/* commonly observed practive to call tcp_setprio(), why? */
	tcp_setprio(newpcb, TCP_PRIO_MIN);

	es = (struct echo_state *)mem_malloc(sizeof(struct echo_state));
	if (es != NULL)
	{
		es->state = ES_ACCEPTED;
		es->pcb = newpcb;
		es->retries = 0;
		es->p = NULL;
		/* pass newly allocated es to our callbacks */
		tcp_arg(newpcb, es);
		tcp_recv(newpcb, echo_recv);
		tcp_err(newpcb, echo_error);
		tcp_poll(newpcb, echo_poll, 0);
		ret_err = ERR_OK;
	} else {
		ret_err = ERR_MEM;
	}
	return ret_err;  
}

static 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 = (struct echo_state *)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;
}

static void
echo_error(void *arg, err_t err)
{
	struct echo_state *es;

	LWIP_UNUSED_ARG(err);

	es = (struct echo_state *)arg;
	if (es != NULL)
	{
		mem_free(es);
	}
}

static err_t
echo_poll(void *arg, struct tcp_pcb *tpcb)
{
	err_t ret_err;
	struct echo_state *es;

	es = (struct echo_state *)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;
}

static 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;
}

static void
echo_send(struct tcp_pcb *tpcb, struct echo_state *es)
{
	struct pbuf *ptr;
	err_t wr_err = ERR_OK;
 
	while ((wr_err == ERR_OK) &&
	       (es->p != NULL) && 
	       (es->p->len <= tcp_sndbuf(tpcb)))
	{
		ptr = es->p;

		/* enqueue data for transmission */
		wr_err = tcp_write(tpcb, ptr->payload, ptr->len, 1);
		if (wr_err == ERR_OK)
		{
			u16_t plen;
			u8_t freed;

			plen = ptr->len;
			/* continue with next pbuf in chain (if any) */
			es->p = ptr->next;
			if(es->p != NULL)
			{
				/* new reference! */
				pbuf_ref(es->p);
			}
			/* chop first pbuf from chain */
			do
			{
				/* try hard to free pbuf */
				freed = pbuf_free(ptr);
			} while(freed == 0);
			/* we can read more data now */
			tcp_recved(tpcb, plen);
		} else if(wr_err == ERR_MEM) {
			/* we are low on memory, try later / harder, defer to poll */
			es->p = ptr;
		} else {
			/* other problem ?? */
		}
	}
}

static void
echo_close(struct tcp_pcb *tpcb, struct echo_state *es)
{
	tcp_arg(tpcb, NULL);
	tcp_sent(tpcb, NULL);
	tcp_recv(tpcb, NULL);
	tcp_err(tpcb, NULL);
	tcp_poll(tpcb, NULL, 0);
  
	if (es != NULL)
	{
		mem_free(es);
	}  
	tcp_close(tpcb);
}

#endif /* LWIP_NETCONN */

#endif /* CONFIG_LWIP */