xref: /openbmc/u-boot/net/arp.c (revision 9c62cc58b8e228e8296630e47b95c15c4a3753a0)
1 /*
2  * (C) Copyright 2000
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * See file CREDITS for list of people who contributed to this
6  * project.
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21  * MA 02111-1307 USA
22  */
23 
24 #include <common.h>
25 #include <command.h>
26 #include <net.h>
27 #include "bootp.h"
28 #include "tftp.h"
29 #include "arp.h"
30 
31 #if (CONFIG_COMMANDS & CFG_CMD_NET)
32 
33 #define TIMEOUT		5		/* Seconds before trying ARP again */
34 #ifndef	CONFIG_NET_RETRY_COUNT
35 # define TIMEOUT_COUNT	5		/* # of timeouts before giving up  */
36 #else
37 # define TIMEOUT_COUNT  (CONFIG_NET_RETRY_COUNT)
38 #endif
39 
40 static void ArpHandler(uchar *pkt, unsigned dest, unsigned src, unsigned len);
41 static void ArpTimeout(void);
42 
43 int	ArpTry = 0;
44 
45 /*
46  *	Handle a ARP received packet.
47  */
48 static void
49 ArpHandler(uchar *pkt, unsigned dest, unsigned src, unsigned len)
50 {
51 	/* Check if the frame is really an ARP reply */
52 	if (memcmp (NetServerEther, NetBcastAddr, 6) != 0) {
53 #ifdef	DEBUG
54 		printf("Got good ARP - start TFTP\n");
55 #endif
56 		TftpStart ();
57 	}
58 }
59 
60 
61 /*
62  *	Timeout on ARP request.
63  */
64 static void
65 ArpTimeout(void)
66 {
67 	if (ArpTry >= TIMEOUT_COUNT) {
68 		puts ("\nRetry count exceeded; starting again\n");
69 		NetStartAgain ();
70 	} else {
71 		NetSetTimeout (TIMEOUT * CFG_HZ, ArpTimeout);
72 		ArpRequest ();
73 	}
74 }
75 
76 
77 void
78 ArpRequest (void)
79 {
80 	int i;
81 	volatile uchar *pkt;
82 	ARP_t *	arp;
83 
84 	printf("ARP broadcast %d\n", ++ArpTry);
85 	pkt = NetTxPacket;
86 
87 	NetSetEther(pkt, NetBcastAddr, PROT_ARP);
88 	pkt += ETHER_HDR_SIZE;
89 
90 	arp = (ARP_t *)pkt;
91 
92 	arp->ar_hrd = htons(ARP_ETHER);
93 	arp->ar_pro = htons(PROT_IP);
94 	arp->ar_hln = 6;
95 	arp->ar_pln = 4;
96 	arp->ar_op  = htons(ARPOP_REQUEST);
97 
98 	memcpy (&arp->ar_data[0], NetOurEther, 6);	/* source ET addr	*/
99 	NetWriteIP((uchar*)&arp->ar_data[6], NetOurIP);	/* source IP addr	*/
100 	for (i=10; i<16; ++i) {
101 		arp->ar_data[i] = 0;			/* dest ET addr = 0	*/
102 	}
103 
104 	if((NetServerIP & NetOurSubnetMask) != (NetOurIP & NetOurSubnetMask)) {
105 	    if (NetOurGatewayIP == 0) {
106 		puts ("## Warning: gatewayip needed but not set\n");
107 	    }
108 	    NetWriteIP((uchar*)&arp->ar_data[16], NetOurGatewayIP);
109 	} else {
110 	    NetWriteIP((uchar*)&arp->ar_data[16], NetServerIP);
111 	}
112 
113 
114 	NetSendPacket(NetTxPacket, ETHER_HDR_SIZE + ARP_HDR_SIZE);
115 
116 	NetSetTimeout(TIMEOUT * CFG_HZ, ArpTimeout);
117 	NetSetHandler(ArpHandler);
118 }
119 
120 #endif /* CFG_CMD_NET */
121