lwip/contrib/apps/tcpecho_raw/tcpecho_raw.c

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/*
* Copyright (c) 2001-2004 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 and a contribution to the lwIP TCP/IP stack.
*
* Credits go to Adam Dunkels (and the current maintainers) of this software.
*
* Christiaan Simons rewrote this file to get a more stable echo example.
*/
/**
* @file
* TCP echo server example using raw API.
*
* Echos all bytes sent by connecting client,
* and passively closes when client is done.
*
*/
#include "lwip/opt.h"
#include "lwip/debug.h"
#include "lwip/stats.h"
#include "lwip/tcp.h"
#include "tcpecho_raw.h"
#if LWIP_TCP && LWIP_CALLBACK_API
static struct tcp_pcb *tcpecho_raw_pcb;
enum tcpecho_raw_states
{
ES_NONE = 0,
ES_ACCEPTED,
ES_RECEIVED,
ES_CLOSING
};
struct tcpecho_raw_state
{
u8_t state;
u8_t retries;
struct tcp_pcb *pcb;
/* pbuf (chain) to recycle */
struct pbuf *p;
};
static void
tcpecho_raw_free(struct tcpecho_raw_state *es)
{
if (es != NULL) {
if (es->p) {
/* free the buffer chain if present */
pbuf_free(es->p);
}
mem_free(es);
}
}
static void
tcpecho_raw_close(struct tcp_pcb *tpcb, struct tcpecho_raw_state *es)
{
tcp_arg(tpcb, NULL);
tcp_sent(tpcb, NULL);
tcp_recv(tpcb, NULL);
tcp_err(tpcb, NULL);
tcp_poll(tpcb, NULL, 0);
tcpecho_raw_free(es);
tcp_close(tpcb);
}
static void
tcpecho_raw_send(struct tcp_pcb *tpcb, struct tcpecho_raw_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;
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 */
pbuf_free(ptr);
/* 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
tcpecho_raw_error(void *arg, err_t err)
{
struct tcpecho_raw_state *es;
LWIP_UNUSED_ARG(err);
es = (struct tcpecho_raw_state *)arg;
tcpecho_raw_free(es);
}
static err_t
tcpecho_raw_poll(void *arg, struct tcp_pcb *tpcb)
{
err_t ret_err;
struct tcpecho_raw_state *es;
es = (struct tcpecho_raw_state *)arg;
if (es != NULL) {
if (es->p != NULL) {
/* there is a remaining pbuf (chain) */
tcpecho_raw_send(tpcb, es);
} else {
/* no remaining pbuf (chain) */
if(es->state == ES_CLOSING) {
tcpecho_raw_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
tcpecho_raw_sent(void *arg, struct tcp_pcb *tpcb, u16_t len)
{
struct tcpecho_raw_state *es;
LWIP_UNUSED_ARG(len);
es = (struct tcpecho_raw_state *)arg;
es->retries = 0;
if(es->p != NULL) {
/* still got pbufs to send */
tcp_sent(tpcb, tcpecho_raw_sent);
tcpecho_raw_send(tpcb, es);
} else {
/* no more pbufs to send */
if(es->state == ES_CLOSING) {
tcpecho_raw_close(tpcb, es);
}
}
return ERR_OK;
}
static err_t
tcpecho_raw_recv(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err)
{
struct tcpecho_raw_state *es;
err_t ret_err;
LWIP_ASSERT("arg != NULL",arg != NULL);
es = (struct tcpecho_raw_state *)arg;
if (p == NULL) {
/* remote host closed connection */
es->state = ES_CLOSING;
if(es->p == NULL) {
/* we're done sending, close it */
tcpecho_raw_close(tpcb, es);
} else {
/* we're not done yet */
tcpecho_raw_send(tpcb, es);
}
ret_err = ERR_OK;
} else if(err != ERR_OK) {
/* cleanup, for unknown reason */
if (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;
tcpecho_raw_send(tpcb, es);
ret_err = ERR_OK;
} else if (es->state == ES_RECEIVED) {
/* read some more data */
if(es->p == NULL) {
es->p = p;
tcpecho_raw_send(tpcb, es);
} else {
struct pbuf *ptr;
/* chain pbufs to the end of what we recv'ed previously */
ptr = es->p;
pbuf_cat(ptr,p);
}
ret_err = ERR_OK;
} else {
/* unkown es->state, trash data */
tcp_recved(tpcb, p->tot_len);
pbuf_free(p);
ret_err = ERR_OK;
}
return ret_err;
}
static err_t
tcpecho_raw_accept(void *arg, struct tcp_pcb *newpcb, err_t err)
{
err_t ret_err;
struct tcpecho_raw_state *es;
LWIP_UNUSED_ARG(arg);
if ((err != ERR_OK) || (newpcb == NULL)) {
return ERR_VAL;
}
/* Unless this pcb should have NORMAL priority, set its priority now.
When running out of pcbs, low priority pcbs can be aborted to create
new pcbs of higher priority. */
tcp_setprio(newpcb, TCP_PRIO_MIN);
es = (struct tcpecho_raw_state *)mem_malloc(sizeof(struct tcpecho_raw_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, tcpecho_raw_recv);
tcp_err(newpcb, tcpecho_raw_error);
tcp_poll(newpcb, tcpecho_raw_poll, 0);
tcp_sent(newpcb, tcpecho_raw_sent);
ret_err = ERR_OK;
} else {
ret_err = ERR_MEM;
}
return ret_err;
}
void
tcpecho_raw_init(void)
{
tcpecho_raw_pcb = tcp_new_ip_type(IPADDR_TYPE_ANY);
if (tcpecho_raw_pcb != NULL) {
err_t err;
err = tcp_bind(tcpecho_raw_pcb, IP_ANY_TYPE, 7);
if (err == ERR_OK) {
tcpecho_raw_pcb = tcp_listen(tcpecho_raw_pcb);
tcp_accept(tcpecho_raw_pcb, tcpecho_raw_accept);
} else {
/* abort? output diagnostic? */
}
} else {
/* abort? output diagnostic? */
}
}
#endif /* LWIP_TCP && LWIP_CALLBACK_API */