1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Copied from Linux Monitor (LiMon) - Networking. 4 * 5 * Copyright 1994 - 2000 Neil Russell. 6 * (See License) 7 * Copyright 2000 Roland Borde 8 * Copyright 2000 Paolo Scaffardi 9 * Copyright 2000-2002 Wolfgang Denk, wd@denx.de 10 */ 11 12#include <common.h> 13#include <env.h> 14#include <log.h> 15#include <net.h> 16#include <linux/delay.h> 17 18#include "arp.h" 19 20struct in_addr net_arp_wait_packet_ip; 21static struct in_addr net_arp_wait_reply_ip; 22/* MAC address of waiting packet's destination */ 23uchar *arp_wait_packet_ethaddr; 24int arp_wait_tx_packet_size; 25ulong arp_wait_timer_start; 26int arp_wait_try; 27uchar *arp_tx_packet; /* THE ARP transmit packet */ 28static uchar arp_tx_packet_buf[PKTSIZE_ALIGN + PKTALIGN]; 29 30void arp_init(void) 31{ 32 /* XXX problem with bss workaround */ 33 arp_wait_packet_ethaddr = NULL; 34 net_arp_wait_packet_ip.s_addr = 0; 35 net_arp_wait_reply_ip.s_addr = 0; 36 arp_wait_tx_packet_size = 0; 37 arp_tx_packet = &arp_tx_packet_buf[0] + (PKTALIGN - 1); 38 arp_tx_packet -= (ulong)arp_tx_packet % PKTALIGN; 39} 40 41void arp_raw_request(struct in_addr source_ip, const uchar *target_ethaddr, 42 struct in_addr target_ip) 43{ 44 uchar *pkt; 45 struct arp_hdr *arp; 46 int eth_hdr_size; 47 48 debug_cond(DEBUG_DEV_PKT, "ARP broadcast %d\n", arp_wait_try); 49 50 pkt = arp_tx_packet; 51 52 eth_hdr_size = net_set_ether(pkt, net_bcast_ethaddr, PROT_ARP); 53 pkt += eth_hdr_size; 54 55 arp = (struct arp_hdr *)pkt; 56 57 arp->ar_hrd = htons(ARP_ETHER); 58 arp->ar_pro = htons(PROT_IP); 59 arp->ar_hln = ARP_HLEN; 60 arp->ar_pln = ARP_PLEN; 61 arp->ar_op = htons(ARPOP_REQUEST); 62 63 memcpy(&arp->ar_sha, net_ethaddr, ARP_HLEN); /* source ET addr */ 64 net_write_ip(&arp->ar_spa, source_ip); /* source IP addr */ 65 memcpy(&arp->ar_tha, target_ethaddr, ARP_HLEN); /* target ET addr */ 66 net_write_ip(&arp->ar_tpa, target_ip); /* target IP addr */ 67 68 net_send_packet(arp_tx_packet, eth_hdr_size + ARP_HDR_SIZE); 69} 70 71void arp_request(void) 72{ 73 if ((net_arp_wait_packet_ip.s_addr & net_netmask.s_addr) != 74 (net_ip.s_addr & net_netmask.s_addr)) { 75 if (net_gateway.s_addr == 0) { 76 puts("## Warning: gatewayip needed but not set\n"); 77 net_arp_wait_reply_ip = net_arp_wait_packet_ip; 78 } else { 79 net_arp_wait_reply_ip = net_gateway; 80 } 81 } else { 82 net_arp_wait_reply_ip = net_arp_wait_packet_ip; 83 } 84 85 arp_raw_request(net_ip, net_null_ethaddr, net_arp_wait_reply_ip); 86} 87 88int arp_timeout_check(void) 89{ 90 ulong t; 91 92 if (!arp_is_waiting()) 93 return 0; 94 95 t = get_timer(0); 96 97 /* check for arp timeout */ 98 if ((t - arp_wait_timer_start) > CONFIG_ARP_TIMEOUT) { 99 arp_wait_try++; 100 101 if (arp_wait_try >= CONFIG_NET_RETRY_COUNT) { 102 puts("\nARP Retry count exceeded; starting again\n"); 103 arp_wait_try = 0; 104 net_set_state(NETLOOP_FAIL); 105 } else { 106 arp_wait_timer_start = t; 107 arp_request(); 108 } 109 } 110 return 1; 111} 112 113void arp_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len) 114{ 115 struct arp_hdr *arp; 116 struct in_addr reply_ip_addr; 117 int eth_hdr_size; 118 uchar *tx_packet; 119 120 /* 121 * We have to deal with two types of ARP packets: 122 * - REQUEST packets will be answered by sending our 123 * IP address - if we know it. 124 * - REPLY packates are expected only after we asked 125 * for the TFTP server's or the gateway's ethernet 126 * address; so if we receive such a packet, we set 127 * the server ethernet address 128 */ 129 debug_cond(DEBUG_NET_PKT, "Got ARP\n"); 130 131 arp = (struct arp_hdr *)ip; 132 if (len < ARP_HDR_SIZE) { 133 printf("bad length %d < %d\n", len, ARP_HDR_SIZE); 134 return; 135 } 136 if (ntohs(arp->ar_hrd) != ARP_ETHER) 137 return; 138 if (ntohs(arp->ar_pro) != PROT_IP) 139 return; 140 if (arp->ar_hln != ARP_HLEN) 141 return; 142 if (arp->ar_pln != ARP_PLEN) 143 return; 144 145 if (net_ip.s_addr == 0) 146 return; 147 148 if (net_read_ip(&arp->ar_tpa).s_addr != net_ip.s_addr) 149 return; 150 151 switch (ntohs(arp->ar_op)) { 152 case ARPOP_REQUEST: 153 /* reply with our IP address */ 154 debug_cond(DEBUG_DEV_PKT, "Got ARP REQUEST, return our IP\n"); 155 eth_hdr_size = net_update_ether(et, et->et_src, PROT_ARP); 156 arp->ar_op = htons(ARPOP_REPLY); 157 memcpy(&arp->ar_tha, &arp->ar_sha, ARP_HLEN); 158 net_copy_ip(&arp->ar_tpa, &arp->ar_spa); 159 memcpy(&arp->ar_sha, net_ethaddr, ARP_HLEN); 160 net_copy_ip(&arp->ar_spa, &net_ip); 161 162#ifdef CONFIG_CMD_LINK_LOCAL 163 /* 164 * Work-around for brain-damaged Cisco equipment with 165 * arp-proxy enabled. 166 * 167 * If the requesting IP is not on our subnet, wait 5ms to 168 * reply to ARP request so that our reply will overwrite 169 * the arp-proxy's instead of the other way around. 170 */ 171 if ((net_read_ip(&arp->ar_tpa).s_addr & net_netmask.s_addr) != 172 (net_read_ip(&arp->ar_spa).s_addr & net_netmask.s_addr)) 173 udelay(5000); 174#endif 175 tx_packet = net_get_async_tx_pkt_buf(); 176 memcpy(tx_packet, et, eth_hdr_size + ARP_HDR_SIZE); 177 net_send_packet(tx_packet, eth_hdr_size + ARP_HDR_SIZE); 178 return; 179 180 case ARPOP_REPLY: /* arp reply */ 181 /* are we waiting for a reply? */ 182 if (!arp_is_waiting()) 183 break; 184 185 if (IS_ENABLED(CONFIG_KEEP_SERVERADDR) && 186 net_server_ip.s_addr == net_arp_wait_packet_ip.s_addr) { 187 char buf[20]; 188 sprintf(buf, "%pM", &arp->ar_sha); 189 env_set("serveraddr", buf); 190 } 191 192 reply_ip_addr = net_read_ip(&arp->ar_spa); 193 194 /* matched waiting packet's address */ 195 if (reply_ip_addr.s_addr == net_arp_wait_reply_ip.s_addr) { 196 debug_cond(DEBUG_DEV_PKT, 197 "Got ARP REPLY, set eth addr (%pM)\n", 198 arp->ar_data); 199 200 /* save address for later use */ 201 if (arp_wait_packet_ethaddr != NULL) 202 memcpy(arp_wait_packet_ethaddr, 203 &arp->ar_sha, ARP_HLEN); 204 205 net_get_arp_handler()((uchar *)arp, 0, reply_ip_addr, 206 0, len); 207 208 /* set the mac address in the waiting packet's header 209 and transmit it */ 210 memcpy(((struct ethernet_hdr *)net_tx_packet)->et_dest, 211 &arp->ar_sha, ARP_HLEN); 212 net_send_packet(net_tx_packet, arp_wait_tx_packet_size); 213 214 /* no arp request pending now */ 215 net_arp_wait_packet_ip.s_addr = 0; 216 arp_wait_tx_packet_size = 0; 217 arp_wait_packet_ethaddr = NULL; 218 } 219 return; 220 default: 221 debug("Unexpected ARP opcode 0x%x\n", 222 ntohs(arp->ar_op)); 223 return; 224 } 225} 226 227bool arp_is_waiting(void) 228{ 229 return !!net_arp_wait_packet_ip.s_addr; 230} 231