Creating a RAW UDP connection in lwip ARP - udp

Question

I am currently working to create a simple transfer protocol over Ethernet. I have a SP605 Xilinx evaluation board which I am using to debug the Ethernet portion of our project. I attempted to cannibalize the example but have so far been unsuccessful. Currently, the communication needs to only be one way. Currently, I am trying to see the data being sent with netcat. I also have wireshark open and am seeing the system get stuck repeatedly asking:
2217 1323.697811000 Xilinx_00:01:02 Broadcast
ARP 60 Who has 192.168.1.11? Tell 192.168.1.10
I can see the Host computer reply with:
2217 1323.697811000 Xilinx_00:01:02 Broadcast
ARP 60 Who has 192.168.1.11? Tell 192.168.1.10
I feel like I have some issues with the configuration but cannot figure out how what it is. I think it might have something to do with a not having a recv handler set but I am not sure.
Below is the code I am using. lwip_init() is mimicking the call from the examples provided by Xilinx.
/*
* main.c
*
* Created on: Sep 24, 2013
* Author: Ian
*/
#include <stdio.h>
#include <string.h>
#include <stdio.h>
#include "lwip/init.h"
#include "xparameters.h"
#include "netif/xadapter.h"
#include "xenv_standalone.h"
#include "platform_config.h"
#include "xparameters.h"
#include "xintc.h"
#include "xil_exception.h"
#include "mb_interface.h"
#include "xtmrctr_l.h"
#include "lwip/udp.h"
#include "lwipopts.h"
#include "xil_printf.h"
struct ip_addr ipaddr, ipaddr_remote, netmask, gw;
void udp_test(void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, u16_t port);
void print_ip(char *msg, struct ip_addr *ip)
{
print(msg);
xil_printf("%d.%d.%d.%d\r\n", ip4_addr1(ip), ip4_addr2(ip),
ip4_addr3(ip), ip4_addr4(ip));
}
void print_ip_settings(struct ip_addr *ip, struct ip_addr *mask, struct ip_addr *gw)
{
print_ip("Board IP: ", ip);
print_ip("Netmask : ", mask);
print_ip("Gateway : ", gw);
}
int main()
{
err_t error;
struct netif *netif, server_netif;
struct udp_pcb *udp_1;
struct pbuf *p;
char data[8] = "01234567";
u16_t Port;
Port = 69;
int count = 0;
int n = 0;
int buflen = 8;
/* the mac address of the board. this should be unique per board */
unsigned char mac_ethernet_address[] = { 0x00, 0x0a, 0x35, 0x00, 0x01, 0x02 };
netif = &server_netif;
xil_printf("\r\n\r\n");
xil_printf("-----lwIP RAW Application ------\r\n");
/* initliaze IP addresses to be used */
IP4_ADDR(&ipaddr_remote, 192, 168, 1, 11);
IP4_ADDR(&ipaddr, 192, 168, 1, 10);
IP4_ADDR(&netmask, 255, 255, 255, 0);
IP4_ADDR(&gw, 192, 168, 1, 1);
print_ip_settings(&ipaddr, &netmask, &gw);
lwip_init();
if (!xemac_add(netif, &ipaddr, &netmask, &gw, mac_ethernet_address, PLATFORM_EMAC_BASEADDR)) {
xil_printf("Error adding N/W interface\r\n");
return -1;
}
netif_set_default(netif);
netif_set_up(netif);
Xil_ExceptionEnable(); //Setup complete start interrupts
udp_1 = udp_new();
error = udp_bind(udp_1, IP_ADDR_ANY, Port);
if (error != 0)
{
xil_printf("Failed %d\r\n", error);
}
else if (error == 0)
{
xil_printf("Success\r\n");
}
error = udp_connect(udp_1, &ipaddr_remote, Port);
if (error != 0)
{
xil_printf("Failed %d\r\n", error);
}
else if (error == 0)
{
xil_printf("Success\r\n");
}
while(1)
{
count++;
xemacif_input(netif);
if (count == 100000)
{
p = pbuf_alloc(PBUF_TRANSPORT, buflen, PBUF_POOL);
if (!p) {
xil_printf("error allocating pbuf\r\n");
return ERR_MEM;
}
memcpy(p->payload, data, buflen);
udp_send(udp_1, p);
xil_printf("SEND\r\n");
count = 0;
pbuf_free(p);
}
}
data[1] = '2';
}

Answer 1

Ok, so basically here is what I found.
The Xilinx xapp1026 had issues with the sp605_AxiEth_32kb_Cache project when I used it. It was hanging at the start interrupts. I was not able to diagnose the project BUT I switched to the sp605_EthernetLite_32kb_Cache example project. I can only assume that the failure of the MicroBlaze interrupts to initialize caused the ARP to fail to get added and forced the system into the loop repeatedly. It is still unclear why the interrupt failed to initialize in the AxiEth example.
Once here I was able to get a program to work by stripping down the provided system and using the following code:
/*
* Copyright (c) 2007 Xilinx, Inc. All rights reserved.
*
* Xilinx, Inc.
* XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS" AS A
* COURTESY TO YOU. BY PROVIDING THIS DESIGN, CODE, OR INFORMATION AS
* ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE, APPLICATION OR
* STANDARD, XILINX IS MAKING NO REPRESENTATION THAT THIS IMPLEMENTATION
* IS FREE FROM ANY CLAIMS OF INFRINGEMENT, AND YOU ARE RESPONSIBLE
* FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE FOR YOUR IMPLEMENTATION.
* XILINX EXPRESSLY DISCLAIMS ANY WARRANTY WHATSOEVER WITH RESPECT TO
* THE ADEQUACY OF THE IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO
* ANY WARRANTIES OR REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE
* FROM CLAIMS OF INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE.
*
*/
#include <stdio.h>
#include <string.h>
#include "lwip/udp.h"
#include "xparameters.h"
#include "netif/xadapter.h"
#include "platform.h"
#include "platform_config.h"
#include "lwipopts.h"
#ifndef __PPC__
#include "xil_printf.h"
#endif
void print_headers();
int start_applications();
int transfer_data();
void platform_enable_interrupts();
void lwip_init(void);
void tcp_fasttmr(void);
void tcp_slowtmr(void);
#if LWIP_DHCP==1
extern volatile int dhcp_timoutcntr;
err_t dhcp_start(struct netif *netif);
#endif
extern volatile int TxPerfConnMonCntr;
extern volatile int TcpFastTmrFlag;
extern volatile int TcpSlowTmrFlag;
void print_ip(char *msg, struct ip_addr *ip)
{
print(msg);
xil_printf("%d.%d.%d.%d\r\n", ip4_addr1(ip), ip4_addr2(ip),
ip4_addr3(ip), ip4_addr4(ip));
}
void print_ip_settings(struct ip_addr *ip, struct ip_addr *mask, struct ip_addr *gw)
{
print_ip("Board IP: ", ip);
print_ip("Netmask : ", mask);
print_ip("Gateway : ", gw);
}
int main()
{
struct netif *netif, server_netif;
struct ip_addr ipaddr, netmask, gw;
// Added stuff for the creation of a basic UDP
err_t error;
struct ip_addr ip_remote;
struct udp_pcb *udp_1;
struct pbuf *p;
char data[8] = "01234567";
u16_t Port = 12;
int buflen = 8;
int count = 0;
/* the mac address of the board. this should be unique per board */
unsigned char mac_ethernet_address[] = { 0x00, 0x0a, 0x35, 0x00, 0x01, 0x02 };
netif = &server_netif;
if (init_platform() < 0) {
xil_printf("ERROR initializing platform.\r\n");
return -1;
}
xil_printf("\r\n\r\n");
xil_printf("-----lwIP RAW Mode Demo Application ------\r\n");
/* initliaze IP addresses to be used */
#if (LWIP_DHCP==0)
IP4_ADDR(&ipaddr, 192, 168, 1, 10);
IP4_ADDR(&netmask, 255, 255, 255, 0);
IP4_ADDR(&gw, 192, 168, 1, 1);
print_ip_settings(&ipaddr, &netmask, &gw);
#endif
lwip_init();
#if (LWIP_DHCP==1)
ipaddr.addr = 0;
gw.addr = 0;
netmask.addr = 0;
#endif
/* Add network interface to the netif_list, and set it as default */
if (!xemac_add(netif, &ipaddr, &netmask, &gw, mac_ethernet_address, PLATFORM_EMAC_BASEADDR)) {
xil_printf("Error adding N/W interface\r\n");
return -1;
}
netif_set_default(netif);
/* specify that the network if is up */
netif_set_up(netif);
/* now enable interrupts */
platform_enable_interrupts();
#if (LWIP_DHCP==1)
/* Create a new DHCP client for this interface.
* Note: you must call dhcp_fine_tmr() and dhcp_coarse_tmr() at
* the predefined regular intervals after starting the client.
*/
dhcp_start(netif);
dhcp_timoutcntr = 24;
TxPerfConnMonCntr = 0;
while(((netif->ip_addr.addr) == 0) && (dhcp_timoutcntr > 0)) {
xemacif_input(netif);
if (TcpFastTmrFlag) {
tcp_fasttmr();
TcpFastTmrFlag = 0;
}
if (TcpSlowTmrFlag) {
tcp_slowtmr();
TcpSlowTmrFlag = 0;
}
}
if (dhcp_timoutcntr <= 0) {
if ((netif->ip_addr.addr) == 0) {
xil_printf("DHCP Timeout\r\n");
xil_printf("Configuring default IP of 192.168.1.10\r\n");
IP4_ADDR(&(netif->ip_addr), 192, 168, 1, 10);
IP4_ADDR(&(netif->netmask), 255, 255, 255, 0);
IP4_ADDR(&(netif->gw), 192, 168, 1, 1);
}
}
/* receive and process packets */
print_ip_settings(&(netif->ip_addr), &(netif->netmask), &(netif->gw));
#endif
/* start the application (web server, rxtest, txtest, etc..) */
xil_printf("Setup Done");
IP4_ADDR(&ip_remote, 192, 168, 1, 11);
udp_1 = udp_new();
error = udp_bind(udp_1, IP_ADDR_ANY, Port);
if (error != 0)
{
xil_printf("Failed %d\r\n", error);
}
else if (error == 0)
{
xil_printf("Success\r\n");
}
error = udp_connect(udp_1, &ip_remote, Port);
if (error != 0)
{
xil_printf("Failed %d\r\n", error);
}
else if (error == 0)
{
xil_printf("Success\r\n");
}
while (1)
{
xemacif_input(netif);
count++;
if (count == 80000)
{
p = pbuf_alloc(PBUF_TRANSPORT, buflen, PBUF_POOL);
if (!p) {
xil_printf("error allocating pbuf\r\n");
return ERR_MEM;
}
memcpy(p->payload, data, buflen);
udp_send(udp_1, p);
xil_printf("SEND\r\n");
count = 0;
pbuf_free(p);
}
}
/* never reached */
cleanup_platform();
return 0;
}
----Edit ----
So you know how people figure it out then don't leave an answer. Well here was my problem with the orginal code (I think..) the line of code xemacif_input(netif); gives the Ethernet the ability to process the arp call without it the FPGA will sending out the ARP and then not receiving it will ask repeatedly.
The previous code does appear to have the correct line of code in it. So it might have been a mistake in how the interrupts were configured.
I got this example working and implemented it in my project. If you have questions about this please ask and I will try and give the best answers I can.