Initial revision

net/arp.c

+/*
+ * (C) Copyright 2000
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <command.h>
+#include <net.h>
+#include "bootp.h"
+#include "tftp.h"
+#include "arp.h"
+
+#if (CONFIG_COMMANDS & CFG_CMD_NET)
+
+#define TIMEOUT		5		/* Seconds before trying ARP again */
+#ifndef	CONFIG_NET_RETRY_COUNT
+# define TIMEOUT_COUNT	5		/* # of timeouts before giving up  */
+#else
+# define TIMEOUT_COUNT  (CONFIG_NET_RETRY_COUNT)
+#endif
+
+static void ArpHandler(uchar *pkt, unsigned dest, unsigned src, unsigned len);
+static void ArpTimeout(void);
+
+int	ArpTry = 0;
+
+/*
+ *	Handle a ARP received packet.
+ */
+static void
+ArpHandler(uchar *pkt, unsigned dest, unsigned src, unsigned len)
+{
+	/* Check if the frame is really an ARP reply */
+	if (memcmp (NetServerEther, NetBcastAddr, 6) != 0) {
+#ifdef	DEBUG
+		printf("Got good ARP - start TFTP\n");
+#endif
+		TftpStart ();
+	}
+}
+
+
+/*
+ *	Timeout on ARP request.
+ */
+static void
+ArpTimeout(void)
+{
+	if (ArpTry >= TIMEOUT_COUNT) {
+		puts ("\nRetry count exceeded; starting again\n");
+		NetStartAgain ();
+	} else {
+		NetSetTimeout (TIMEOUT * CFG_HZ, ArpTimeout);
+		ArpRequest ();
+	}
+}
+
+
+void
+ArpRequest (void)
+{
+	int i;
+	volatile uchar *pkt;
+	ARP_t *	arp;
+
+	printf("ARP broadcast %d\n", ++ArpTry);
+	pkt = NetTxPacket;
+
+	NetSetEther(pkt, NetBcastAddr, PROT_ARP);
+	pkt += ETHER_HDR_SIZE;
+
+	arp = (ARP_t *)pkt;
+
+	arp->ar_hrd = htons(ARP_ETHER);
+	arp->ar_pro = htons(PROT_IP);
+	arp->ar_hln = 6;
+	arp->ar_pln = 4;
+	arp->ar_op  = htons(ARPOP_REQUEST);
+
+	memcpy (&arp->ar_data[0], NetOurEther, 6);	/* source ET addr	*/
+	NetWriteIP((uchar*)&arp->ar_data[6], NetOurIP);	/* source IP addr	*/
+	for (i=10; i<16; ++i) {
+		arp->ar_data[i] = 0;			/* dest ET addr = 0	*/
+	}
+
+	if((NetServerIP & NetOurSubnetMask) != (NetOurIP & NetOurSubnetMask)) {
+	    if (NetOurGatewayIP == 0) {
+		puts ("## Warning: gatewayip needed but not set\n");
+	    }
+	    NetWriteIP((uchar*)&arp->ar_data[16], NetOurGatewayIP);
+	} else {
+	    NetWriteIP((uchar*)&arp->ar_data[16], NetServerIP);
+	}
+
+
+	NetSendPacket(NetTxPacket, ETHER_HDR_SIZE + ARP_HDR_SIZE);
+
+	NetSetTimeout(TIMEOUT * CFG_HZ, ArpTimeout);
+	NetSetHandler(ArpHandler);
+}
+
+#endif /* CFG_CMD_NET */