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