xref: /openbmc/u-boot/net/rarp.c (revision 7ca6f363)
1 /*
2  * (C) Copyright 2000-2002
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <command.h>
10 #include <net.h>
11 #include "nfs.h"
12 #include "bootp.h"
13 #include "rarp.h"
14 #include "tftp.h"
15 
16 #define TIMEOUT 5000UL /* Milliseconds before trying BOOTP again */
17 #ifndef	CONFIG_NET_RETRY_COUNT
18 #define TIMEOUT_COUNT 5 /* # of timeouts before giving up  */
19 #else
20 #define TIMEOUT_COUNT (CONFIG_NET_RETRY_COUNT)
21 #endif
22 
23 int RarpTry;
24 
25 /*
26  *	Handle a RARP received packet.
27  */
28 void rarp_receive(struct ip_udp_hdr *ip, unsigned len)
29 {
30 	struct arp_hdr *arp;
31 
32 	debug_cond(DEBUG_NET_PKT, "Got RARP\n");
33 	arp = (struct arp_hdr *)ip;
34 	if (len < ARP_HDR_SIZE) {
35 		printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
36 		return;
37 	}
38 
39 	if ((ntohs(arp->ar_op) != RARPOP_REPLY) ||
40 		(ntohs(arp->ar_hrd) != ARP_ETHER)   ||
41 		(ntohs(arp->ar_pro) != PROT_IP)     ||
42 		(arp->ar_hln != 6) || (arp->ar_pln != 4)) {
43 
44 		puts("invalid RARP header\n");
45 	} else {
46 		NetCopyIP(&NetOurIP, &arp->ar_data[16]);
47 		if (NetServerIP == 0)
48 			NetCopyIP(&NetServerIP, &arp->ar_data[6]);
49 		memcpy(NetServerEther, &arp->ar_data[0], 6);
50 		debug_cond(DEBUG_DEV_PKT, "Got good RARP\n");
51 		net_auto_load();
52 	}
53 }
54 
55 
56 /*
57  *	Timeout on BOOTP request.
58  */
59 static void RarpTimeout(void)
60 {
61 	if (RarpTry >= TIMEOUT_COUNT) {
62 		puts("\nRetry count exceeded; starting again\n");
63 		NetStartAgain();
64 	} else {
65 		NetSetTimeout(TIMEOUT, RarpTimeout);
66 		RarpRequest();
67 	}
68 }
69 
70 
71 void RarpRequest(void)
72 {
73 	uchar *pkt;
74 	struct arp_hdr *rarp;
75 	int eth_hdr_size;
76 
77 	printf("RARP broadcast %d\n", ++RarpTry);
78 	pkt = NetTxPacket;
79 
80 	eth_hdr_size = NetSetEther(pkt, NetBcastAddr, PROT_RARP);
81 	pkt += eth_hdr_size;
82 
83 	rarp = (struct arp_hdr *)pkt;
84 
85 	rarp->ar_hrd = htons(ARP_ETHER);
86 	rarp->ar_pro = htons(PROT_IP);
87 	rarp->ar_hln = 6;
88 	rarp->ar_pln = 4;
89 	rarp->ar_op  = htons(RARPOP_REQUEST);
90 	memcpy(&rarp->ar_data[0],  NetOurEther, 6);	/* source ET addr */
91 	memcpy(&rarp->ar_data[6],  &NetOurIP,   4);	/* source IP addr */
92 	/* dest ET addr = source ET addr ??*/
93 	memcpy(&rarp->ar_data[10], NetOurEther, 6);
94 	/* dest IP addr set to broadcast */
95 	memset(&rarp->ar_data[16], 0xff,        4);
96 
97 	NetSendPacket(NetTxPacket, eth_hdr_size + ARP_HDR_SIZE);
98 
99 	NetSetTimeout(TIMEOUT, RarpTimeout);
100 }
101