I am trying to build a simple TCP echoserver and client for same using
netconn API.
I am sure some might already have tried but i couldn't find any source on
internet
My system is running ubuntu 10.10
Directory structure to refer for compile instruction
/contrib
/lwip
/server.c
/lwipopts.h
File content
*lwipopts.h [i think there might me more required here that i don't
know of]*
#define LWIP_SOCKET 0
*server.c [took the basic code from *Design and Implementation of the
lwIPTCP/IP Stack*]*
#include <stdio.h>
#include <lwip/api.h>
int main()
{
struct netconn *conn, *newconn;
err_t err;
/* create a connection structure */
conn = netconn_new(NETCONN_TCP);
/* bind the connection to port 2000 on any local IP address */
*netconn_bind(conn, NULL, 7);*
printf("Now listening\n");
/* tell the connection to listen for incoming connection requests */
netconn_listen(conn);
/* Grab new connection. */
err = netconn_accept(conn, &newconn);
printf("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)
{
printf("Received data\n");
do{
netbuf_data(buf, &data, &len);
err = netconn_write(newconn, data, len, NETCONN_COPY);
if (err != ERR_OK)
printf("tcpecho: netconn_write: error \"%s\"\n", lwip_strerr(err));
}while (netbuf_next(buf) >= 0);
netbuf_delete(buf);
}
/* Close connection and discard connection identifier. */
netconn_close(newconn);
netconn_delete(newconn);
}
}
compile instruction
gcc -I. -I lwip/src/include/ -I contrib/ports/unix/include/ -I
lwip/src/include/ipv4/ lwip/src/api/*.c lwip/src/core/*.c
lwip/src/core/ipv4/*.c contrib/ports/unix/sys_arch.c
lwip/src/netif/etharp.c -lpthread server.c
Problem
All files are included and no errors / warnings occur for compile
But in netconn_bind I receive an error
*Assertion "netconn_bind: invalid conn" failed at line 172 in
lwip/src/api/api_lib.c*
*Aborted*
Please let me know if i am missing something obvious
Also i did try to understand the server implementation from simhost but it
is too complicated for a basic echoserver application
So any reference manual or if someone has already build such application
for a start then a link to it is deeply appreciated.
--
Thanks
Regards
Saket Chawla
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