Part Number: MCU-PLUS-SDK-AM243X
When using the LWIP posix-compatible socket API if I close the socket and then re-open a new socket and attempt to bind it to the same port, bind will fail with error EADDRINUSE(98). Is there any way to make sure to release the address/port when closing a socket?
This does not seem to happen with the netconn API. I am able to repeatedly close and open a netconn connection and bind it to the same port.
I have attached sample code adapted from one of the lwip examples. I am using MCU+SDK AM243x 8.6.0.45
/*
* 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 Files */
/* ========================================================================== */
#include <string.h>
#include <stdio.h>
/*
#include "lwip/opt.h"
#include "lwip/api.h"
*/
#include "lwip/sys.h"
#include <kernel/dpl/ClockP.h>
#include "enet_apputils.h"
#include <sys/socket.h>
// These are defined here because netinet/in.h does not exist in freertos
#define SOMAXCONN 128
#define IPPROTO_IPV4 4
#include <errno.h>
#include <netdb.h>
/* ========================================================================== */
/* Macros & Typedefs */
/* ========================================================================== */
#define MAX_MESSAGE_SIZE (256)
#define APP_SERVER_PORT (8889)
static const uint8_t APP_CLIENT_TX_MSG1[] = "Greetings from Texas Instruments!";
/* ========================================================================== */
/* Structure Declarations */
/* ========================================================================== */
/* ========================================================================== */
/* Function Declarations */
/* ========================================================================== */
static void AppTcp_ServerTask(void *arg);
/* ========================================================================== */
/* Global Variables */
/* ========================================================================== */
/* ========================================================================== */
/* Function Definitions */
/* ========================================================================== */
static void AppTcp_ServerTask(void *arg)
{
struct netconn *pConn = NULL, *pClientConn = NULL;
err_t err;
LWIP_UNUSED_ARG(arg);
int server_fd, new_socket, ret, i, size;
struct sockaddr_in address;
int addrlen = sizeof(address);
static char buffer[MAX_MESSAGE_SIZE] = {0};
while (1)
{
server_fd = socket(AF_INET, SOCK_STREAM, 0);
LWIP_ERROR("tcpecho: invalid socket\r\n", (server_fd >= 0), return);
address.sin_family = AF_INET;
address.sin_addr.s_addr = INADDR_ANY;
address.sin_port = htons(APP_SERVER_PORT);
/* This fails on the second iteration */
ret = bind(server_fd, (struct sockaddr *)&address, sizeof(address));
LWIP_ERROR("tcpecho: bind failed\r\n", (ret >= 0), return);
/* Tell connection to go into listening mode. */
listen(server_fd, 3);
for (i = 0; i < 2; i++)
{
/* Grab new connection. */
new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t*)&addrlen);
LWIP_ERROR("tcpecho: accept failed\r\n", (new_socket >= 0), return);
printf("accepted new connection %d\r\n", new_socket);
ret = recv(new_socket, buffer, MAX_MESSAGE_SIZE, 0);
LWIP_ERROR("tcpecho: recv failed\r\n", (ret >= 0), return);
size = ret;
ret = send(new_socket, buffer, size, 0);
LWIP_ERROR("tcpecho: send failed\r\n", (ret >= 0), return);
/* Close connection and discard connection identifier. */
close(new_socket);
}
close(server_fd);
}
}
void AppTcp_startServer_socket()
{
sys_thread_new("AppTcp_ServerTask_socket", AppTcp_ServerTask, NULL, DEFAULT_THREAD_STACKSIZE, DEFAULT_THREAD_PRIO);
}
/*-----------------------------------------------------------------------------------*/
