ping.c
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/*
* Copied from Linux Monitor (LiMon) - Networking.
*
* Copyright 1994 - 2000 Neil Russell.
* (See License)
* Copyright 2000 Roland Borde
* Copyright 2000 Paolo Scaffardi
* Copyright 2000-2002 Wolfgang Denk, wd@denx.de
* SPDX-License-Identifier: GPL-2.0
*/
#include "ping.h"
#include "arp.h"
static ushort PingSeqNo;
/* The ip address to ping */
IPaddr_t NetPingIP;
static void set_icmp_header(uchar *pkt, IPaddr_t dest)
{
/*
* Construct an IP and ICMP header.
*/
struct ip_hdr *ip = (struct ip_hdr *)pkt;
struct icmp_hdr *icmp = (struct icmp_hdr *)(pkt + IP_HDR_SIZE);
net_set_ip_header(pkt, dest, NetOurIP);
ip->ip_len = htons(IP_ICMP_HDR_SIZE);
ip->ip_p = IPPROTO_ICMP;
ip->ip_sum = compute_ip_checksum(ip, IP_HDR_SIZE);
icmp->type = ICMP_ECHO_REQUEST;
icmp->code = 0;
icmp->checksum = 0;
icmp->un.echo.id = 0;
icmp->un.echo.sequence = htons(PingSeqNo++);
icmp->checksum = compute_ip_checksum(icmp, ICMP_HDR_SIZE);
}
static int ping_send(void)
{
uchar *pkt;
int eth_hdr_size;
/* XXX always send arp request */
debug_cond(DEBUG_DEV_PKT, "sending ARP for %pI4\n", &NetPingIP);
NetArpWaitPacketIP = NetPingIP;
eth_hdr_size = NetSetEther(NetTxPacket, NetEtherNullAddr, PROT_IP);
pkt = (uchar *)NetTxPacket + eth_hdr_size;
set_icmp_header(pkt, NetPingIP);
/* size of the waiting packet */
NetArpWaitTxPacketSize = eth_hdr_size + IP_ICMP_HDR_SIZE;
/* and do the ARP request */
NetArpWaitTry = 1;
NetArpWaitTimerStart = get_timer(0);
ArpRequest();
return 1; /* waiting */
}
static void ping_timeout(void)
{
eth_halt();
net_set_state(NETLOOP_FAIL); /* we did not get the reply */
}
void ping_start(void)
{
printf("Using %s device\n", eth_get_name());
NetSetTimeout(10000UL, ping_timeout);
ping_send();
}
void ping_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len)
{
struct icmp_hdr *icmph = (struct icmp_hdr *)&ip->udp_src;
IPaddr_t src_ip;
int eth_hdr_size;
switch (icmph->type) {
case ICMP_ECHO_REPLY:
src_ip = NetReadIP((void *)&ip->ip_src);
if (src_ip == NetPingIP)
net_set_state(NETLOOP_SUCCESS);
return;
case ICMP_ECHO_REQUEST:
eth_hdr_size = net_update_ether(et, et->et_src, PROT_IP);
debug_cond(DEBUG_DEV_PKT, "Got ICMP ECHO REQUEST, return "
"%d bytes\n", eth_hdr_size + len);
ip->ip_sum = 0;
ip->ip_off = 0;
NetCopyIP((void *)&ip->ip_dst, &ip->ip_src);
NetCopyIP((void *)&ip->ip_src, &NetOurIP);
ip->ip_sum = compute_ip_checksum(ip, IP_HDR_SIZE);
icmph->type = ICMP_ECHO_REPLY;
icmph->checksum = 0;
icmph->checksum = compute_ip_checksum(icmph, len - IP_HDR_SIZE);
NetSendPacket((uchar *)et, eth_hdr_size + len);
return;
/* default:
return;*/
}
}