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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 <common.h>
#include "arp.h"
#ifndef CONFIG_ARP_TIMEOUT
/* Milliseconds before trying ARP again */
# define ARP_TIMEOUT 5000UL
#else
# define ARP_TIMEOUT CONFIG_ARP_TIMEOUT
#endif
#ifndef CONFIG_NET_RETRY_COUNT
# define ARP_TIMEOUT_COUNT 5 /* # of timeouts before giving up */
#else
# define ARP_TIMEOUT_COUNT CONFIG_NET_RETRY_COUNT
#endif
IPaddr_t NetArpWaitPacketIP;
static IPaddr_t NetArpWaitReplyIP;
/* MAC address of waiting packet's destination */
uchar *NetArpWaitPacketMAC;
int NetArpWaitTxPacketSize;
ulong NetArpWaitTimerStart;
int NetArpWaitTry;
static uchar *NetArpTxPacket; /* THE ARP transmit packet */
static uchar NetArpPacketBuf[PKTSIZE_ALIGN + PKTALIGN];
void ArpInit(void)
{
/* XXX problem with bss workaround */
NetArpWaitPacketMAC = NULL;
NetArpWaitPacketIP = 0;
NetArpWaitReplyIP = 0;
NetArpWaitTxPacketSize = 0;
NetArpTxPacket = &NetArpPacketBuf[0] + (PKTALIGN - 1);
NetArpTxPacket -= (ulong)NetArpTxPacket % PKTALIGN;
}
void arp_raw_request(IPaddr_t sourceIP, const uchar *targetEther,
IPaddr_t targetIP)
{
uchar *pkt;
struct arp_hdr *arp;
int eth_hdr_size;
debug_cond(DEBUG_DEV_PKT, "ARP broadcast %d\n", NetArpWaitTry);
pkt = NetArpTxPacket;
eth_hdr_size = NetSetEther(pkt, NetBcastAddr, PROT_ARP);
pkt += eth_hdr_size;
arp = (struct arp_hdr *) pkt;
arp->ar_hrd = htons(ARP_ETHER);
arp->ar_pro = htons(PROT_IP);
arp->ar_hln = ARP_HLEN;
arp->ar_pln = ARP_PLEN;
arp->ar_op = htons(ARPOP_REQUEST);
memcpy(&arp->ar_sha, NetOurEther, ARP_HLEN); /* source ET addr */
NetWriteIP(&arp->ar_spa, sourceIP); /* source IP addr */
memcpy(&arp->ar_tha, targetEther, ARP_HLEN); /* target ET addr */
NetWriteIP(&arp->ar_tpa, targetIP); /* target IP addr */
NetSendPacket(NetArpTxPacket, eth_hdr_size + ARP_HDR_SIZE);
}
void ArpRequest(void)
{
if ((NetArpWaitPacketIP & NetOurSubnetMask) !=
(NetOurIP & NetOurSubnetMask)) {
if (NetOurGatewayIP == 0) {
puts("## Warning: gatewayip needed but not set\n");
NetArpWaitReplyIP = NetArpWaitPacketIP;
} else {
NetArpWaitReplyIP = NetOurGatewayIP;
}
} else {
NetArpWaitReplyIP = NetArpWaitPacketIP;
}
arp_raw_request(NetOurIP, NetEtherNullAddr, NetArpWaitReplyIP);
}
void ArpTimeoutCheck(void)
{
ulong t;
if (!NetArpWaitPacketIP)
return;
t = get_timer(0);
/* check for arp timeout */
if ((t - NetArpWaitTimerStart) > ARP_TIMEOUT) {
NetArpWaitTry++;
if (NetArpWaitTry >= ARP_TIMEOUT_COUNT) {
puts("\nARP Retry count exceeded; starting again\n");
NetArpWaitTry = 0;
NetStartAgain();
} else {
NetArpWaitTimerStart = t;
ArpRequest();
}
}
}
void ArpReceive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len)
{
struct arp_hdr *arp;
IPaddr_t reply_ip_addr;
uchar *pkt;
int eth_hdr_size;
/*
* We have to deal with two types of ARP packets:
* - REQUEST packets will be answered by sending our
* IP address - if we know it.
* - REPLY packates are expected only after we asked
* for the TFTP server's or the gateway's ethernet
* address; so if we receive such a packet, we set
* the server ethernet address
*/
debug_cond(DEBUG_NET_PKT, "Got ARP\n");
arp = (struct arp_hdr *)ip;
if (len < ARP_HDR_SIZE) {
printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
return;
}
if (ntohs(arp->ar_hrd) != ARP_ETHER)
return;
if (ntohs(arp->ar_pro) != PROT_IP)
return;
if (arp->ar_hln != ARP_HLEN)
return;
if (arp->ar_pln != ARP_PLEN)
return;
if (NetOurIP == 0)
return;
if (NetReadIP(&arp->ar_tpa) != NetOurIP)
return;
switch (ntohs(arp->ar_op)) {
case ARPOP_REQUEST:
/* reply with our IP address */
debug_cond(DEBUG_DEV_PKT, "Got ARP REQUEST, return our IP\n");
pkt = (uchar *)et;
eth_hdr_size = net_update_ether(et, et->et_src, PROT_ARP);
pkt += eth_hdr_size;
arp->ar_op = htons(ARPOP_REPLY);
memcpy(&arp->ar_tha, &arp->ar_sha, ARP_HLEN);
NetCopyIP(&arp->ar_tpa, &arp->ar_spa);
memcpy(&arp->ar_sha, NetOurEther, ARP_HLEN);
NetCopyIP(&arp->ar_spa, &NetOurIP);
#ifdef CONFIG_CMD_LINK_LOCAL
/*
* Work-around for brain-damaged Cisco equipment with
* arp-proxy enabled.
*
* If the requesting IP is not on our subnet, wait 5ms to
* reply to ARP request so that our reply will overwrite
* the arp-proxy's instead of the other way around.
*/
if ((NetReadIP(&arp->ar_tpa) & NetOurSubnetMask) !=
(NetReadIP(&arp->ar_spa) & NetOurSubnetMask))
udelay(5000);
#endif
NetSendPacket((uchar *)et, eth_hdr_size + ARP_HDR_SIZE);
return;
case ARPOP_REPLY: /* arp reply */
/* are we waiting for a reply */
if (!NetArpWaitPacketIP)
break;
#ifdef CONFIG_KEEP_SERVERADDR
if (NetServerIP == NetArpWaitPacketIP) {
char buf[20];
sprintf(buf, "%pM", &arp->ar_sha);
setenv("serveraddr", buf);
}
#endif
reply_ip_addr = NetReadIP(&arp->ar_spa);
/* matched waiting packet's address */
if (reply_ip_addr == NetArpWaitReplyIP) {
debug_cond(DEBUG_DEV_PKT,
"Got ARP REPLY, set eth addr (%pM)\n",
arp->ar_data);
/* save address for later use */
if (NetArpWaitPacketMAC != NULL)
memcpy(NetArpWaitPacketMAC,
&arp->ar_sha, ARP_HLEN);
net_get_arp_handler()((uchar *)arp, 0, reply_ip_addr,
0, len);
/* set the mac address in the waiting packet's header
and transmit it */
memcpy(((struct ethernet_hdr *)NetTxPacket)->et_dest,
&arp->ar_sha, ARP_HLEN);
NetSendPacket(NetTxPacket, NetArpWaitTxPacketSize);
/* no arp request pending now */
NetArpWaitPacketIP = 0;
NetArpWaitTxPacketSize = 0;
NetArpWaitPacketMAC = NULL;
}
return;
default:
debug("Unexpected ARP opcode 0x%x\n",
ntohs(arp->ar_op));
return;
}
}
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