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
18 int rarp_try;
19
20 /*
21 * Handle a RARP received packet.
22 */
rarp_receive(struct ip_udp_hdr * ip,unsigned len)23 void 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 */
rarp_timeout_handler(void)53 static 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
rarp_request(void)65 void 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