xref: /openbmc/u-boot/net/rarp.c (revision 3f82d89d)
1 /*
2  * (C) Copyright 2000-2002
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 "nfs.h"
28 #include "bootp.h"
29 #include "rarp.h"
30 #include "tftp.h"
31 
32 #define TIMEOUT 5000UL /* Milliseconds before trying BOOTP again */
33 #ifndef	CONFIG_NET_RETRY_COUNT
34 #define TIMEOUT_COUNT 5 /* # of timeouts before giving up  */
35 #else
36 #define TIMEOUT_COUNT (CONFIG_NET_RETRY_COUNT)
37 #endif
38 
39 int RarpTry;
40 
41 /*
42  *	Handle a RARP received packet.
43  */
44 void rarp_receive(struct ip_udp_hdr *ip, unsigned len)
45 {
46 	struct arp_hdr *arp;
47 
48 	debug_cond(DEBUG_NET_PKT, "Got RARP\n");
49 	arp = (struct arp_hdr *)ip;
50 	if (len < ARP_HDR_SIZE) {
51 		printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
52 		return;
53 	}
54 
55 	if ((ntohs(arp->ar_op) != RARPOP_REPLY) ||
56 		(ntohs(arp->ar_hrd) != ARP_ETHER)   ||
57 		(ntohs(arp->ar_pro) != PROT_IP)     ||
58 		(arp->ar_hln != 6) || (arp->ar_pln != 4)) {
59 
60 		puts("invalid RARP header\n");
61 	} else {
62 		NetCopyIP(&NetOurIP, &arp->ar_data[16]);
63 		if (NetServerIP == 0)
64 			NetCopyIP(&NetServerIP, &arp->ar_data[6]);
65 		memcpy(NetServerEther, &arp->ar_data[0], 6);
66 		debug_cond(DEBUG_DEV_PKT, "Got good RARP\n");
67 		net_auto_load();
68 	}
69 }
70 
71 
72 /*
73  *	Timeout on BOOTP request.
74  */
75 static void RarpTimeout(void)
76 {
77 	if (RarpTry >= TIMEOUT_COUNT) {
78 		puts("\nRetry count exceeded; starting again\n");
79 		NetStartAgain();
80 	} else {
81 		NetSetTimeout(TIMEOUT, RarpTimeout);
82 		RarpRequest();
83 	}
84 }
85 
86 
87 void RarpRequest(void)
88 {
89 	uchar *pkt;
90 	struct arp_hdr *rarp;
91 	int eth_hdr_size;
92 
93 	printf("RARP broadcast %d\n", ++RarpTry);
94 	pkt = NetTxPacket;
95 
96 	eth_hdr_size = NetSetEther(pkt, NetBcastAddr, PROT_RARP);
97 	pkt += eth_hdr_size;
98 
99 	rarp = (struct arp_hdr *)pkt;
100 
101 	rarp->ar_hrd = htons(ARP_ETHER);
102 	rarp->ar_pro = htons(PROT_IP);
103 	rarp->ar_hln = 6;
104 	rarp->ar_pln = 4;
105 	rarp->ar_op  = htons(RARPOP_REQUEST);
106 	memcpy(&rarp->ar_data[0],  NetOurEther, 6);	/* source ET addr */
107 	memcpy(&rarp->ar_data[6],  &NetOurIP,   4);	/* source IP addr */
108 	/* dest ET addr = source ET addr ??*/
109 	memcpy(&rarp->ar_data[10], NetOurEther, 6);
110 	/* dest IP addr set to broadcast */
111 	memset(&rarp->ar_data[16], 0xff,        4);
112 
113 	NetSendPacket(NetTxPacket, eth_hdr_size + ARP_HDR_SIZE);
114 
115 	NetSetTimeout(TIMEOUT, RarpTimeout);
116 }
117