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