1 // SPDX-License-Identifier: GPL-2.0
3 * Copied from Linux Monitor (LiMon) - Networking.
5 * Copyright 1994 - 2000 Neil Russell.
7 * Copyright 2000 Roland Borde
8 * Copyright 2000 Paolo Scaffardi
9 * Copyright 2000-2002 Wolfgang Denk, wd@denx.de
19 #ifndef CONFIG_ARP_TIMEOUT
20 /* Milliseconds before trying ARP again */
21 # define ARP_TIMEOUT 5000UL
23 # define ARP_TIMEOUT CONFIG_ARP_TIMEOUT
27 #ifndef CONFIG_NET_RETRY_COUNT
28 # define ARP_TIMEOUT_COUNT 5 /* # of timeouts before giving up */
30 # define ARP_TIMEOUT_COUNT CONFIG_NET_RETRY_COUNT
33 struct in_addr net_arp_wait_packet_ip;
34 static struct in_addr net_arp_wait_reply_ip;
35 /* MAC address of waiting packet's destination */
36 uchar *arp_wait_packet_ethaddr;
37 int arp_wait_tx_packet_size;
38 ulong arp_wait_timer_start;
40 uchar *arp_tx_packet; /* THE ARP transmit packet */
41 static uchar arp_tx_packet_buf[PKTSIZE_ALIGN + PKTALIGN];
45 /* XXX problem with bss workaround */
46 arp_wait_packet_ethaddr = NULL;
47 net_arp_wait_packet_ip.s_addr = 0;
48 net_arp_wait_reply_ip.s_addr = 0;
49 arp_wait_tx_packet_size = 0;
50 arp_tx_packet = &arp_tx_packet_buf[0] + (PKTALIGN - 1);
51 arp_tx_packet -= (ulong)arp_tx_packet % PKTALIGN;
54 void arp_raw_request(struct in_addr source_ip, const uchar *target_ethaddr,
55 struct in_addr target_ip)
61 debug_cond(DEBUG_DEV_PKT, "ARP broadcast %d\n", arp_wait_try);
65 eth_hdr_size = net_set_ether(pkt, net_bcast_ethaddr, PROT_ARP);
68 arp = (struct arp_hdr *)pkt;
70 arp->ar_hrd = htons(ARP_ETHER);
71 arp->ar_pro = htons(PROT_IP);
72 arp->ar_hln = ARP_HLEN;
73 arp->ar_pln = ARP_PLEN;
74 arp->ar_op = htons(ARPOP_REQUEST);
76 memcpy(&arp->ar_sha, net_ethaddr, ARP_HLEN); /* source ET addr */
77 net_write_ip(&arp->ar_spa, source_ip); /* source IP addr */
78 memcpy(&arp->ar_tha, target_ethaddr, ARP_HLEN); /* target ET addr */
79 net_write_ip(&arp->ar_tpa, target_ip); /* target IP addr */
81 net_send_packet(arp_tx_packet, eth_hdr_size + ARP_HDR_SIZE);
84 void arp_request(void)
86 if ((net_arp_wait_packet_ip.s_addr & net_netmask.s_addr) !=
87 (net_ip.s_addr & net_netmask.s_addr)) {
88 if (net_gateway.s_addr == 0) {
89 puts("## Warning: gatewayip needed but not set\n");
90 net_arp_wait_reply_ip = net_arp_wait_packet_ip;
92 net_arp_wait_reply_ip = net_gateway;
95 net_arp_wait_reply_ip = net_arp_wait_packet_ip;
98 arp_raw_request(net_ip, net_null_ethaddr, net_arp_wait_reply_ip);
101 int arp_timeout_check(void)
105 if (!arp_is_waiting())
110 /* check for arp timeout */
111 if ((t - arp_wait_timer_start) > ARP_TIMEOUT) {
114 if (arp_wait_try >= ARP_TIMEOUT_COUNT) {
115 puts("\nARP Retry count exceeded; starting again\n");
117 net_set_state(NETLOOP_FAIL);
119 arp_wait_timer_start = t;
126 void arp_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len)
129 struct in_addr reply_ip_addr;
134 * We have to deal with two types of ARP packets:
135 * - REQUEST packets will be answered by sending our
136 * IP address - if we know it.
137 * - REPLY packates are expected only after we asked
138 * for the TFTP server's or the gateway's ethernet
139 * address; so if we receive such a packet, we set
140 * the server ethernet address
142 debug_cond(DEBUG_NET_PKT, "Got ARP\n");
144 arp = (struct arp_hdr *)ip;
145 if (len < ARP_HDR_SIZE) {
146 printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
149 if (ntohs(arp->ar_hrd) != ARP_ETHER)
151 if (ntohs(arp->ar_pro) != PROT_IP)
153 if (arp->ar_hln != ARP_HLEN)
155 if (arp->ar_pln != ARP_PLEN)
158 if (net_ip.s_addr == 0)
161 if (net_read_ip(&arp->ar_tpa).s_addr != net_ip.s_addr)
164 switch (ntohs(arp->ar_op)) {
166 /* reply with our IP address */
167 debug_cond(DEBUG_DEV_PKT, "Got ARP REQUEST, return our IP\n");
168 eth_hdr_size = net_update_ether(et, et->et_src, PROT_ARP);
169 arp->ar_op = htons(ARPOP_REPLY);
170 memcpy(&arp->ar_tha, &arp->ar_sha, ARP_HLEN);
171 net_copy_ip(&arp->ar_tpa, &arp->ar_spa);
172 memcpy(&arp->ar_sha, net_ethaddr, ARP_HLEN);
173 net_copy_ip(&arp->ar_spa, &net_ip);
175 #ifdef CONFIG_CMD_LINK_LOCAL
177 * Work-around for brain-damaged Cisco equipment with
180 * If the requesting IP is not on our subnet, wait 5ms to
181 * reply to ARP request so that our reply will overwrite
182 * the arp-proxy's instead of the other way around.
184 if ((net_read_ip(&arp->ar_tpa).s_addr & net_netmask.s_addr) !=
185 (net_read_ip(&arp->ar_spa).s_addr & net_netmask.s_addr))
188 tx_packet = net_get_async_tx_pkt_buf();
189 memcpy(tx_packet, et, eth_hdr_size + ARP_HDR_SIZE);
190 net_send_packet(tx_packet, eth_hdr_size + ARP_HDR_SIZE);
193 case ARPOP_REPLY: /* arp reply */
194 /* are we waiting for a reply? */
195 if (!arp_is_waiting())
198 #ifdef CONFIG_KEEP_SERVERADDR
199 if (net_server_ip.s_addr == net_arp_wait_packet_ip.s_addr) {
201 sprintf(buf, "%pM", &arp->ar_sha);
202 env_set("serveraddr", buf);
206 reply_ip_addr = net_read_ip(&arp->ar_spa);
208 /* matched waiting packet's address */
209 if (reply_ip_addr.s_addr == net_arp_wait_reply_ip.s_addr) {
210 debug_cond(DEBUG_DEV_PKT,
211 "Got ARP REPLY, set eth addr (%pM)\n",
214 /* save address for later use */
215 if (arp_wait_packet_ethaddr != NULL)
216 memcpy(arp_wait_packet_ethaddr,
217 &arp->ar_sha, ARP_HLEN);
219 net_get_arp_handler()((uchar *)arp, 0, reply_ip_addr,
222 /* set the mac address in the waiting packet's header
224 memcpy(((struct ethernet_hdr *)net_tx_packet)->et_dest,
225 &arp->ar_sha, ARP_HLEN);
226 net_send_packet(net_tx_packet, arp_wait_tx_packet_size);
228 /* no arp request pending now */
229 net_arp_wait_packet_ip.s_addr = 0;
230 arp_wait_tx_packet_size = 0;
231 arp_wait_packet_ethaddr = NULL;
235 debug("Unexpected ARP opcode 0x%x\n",
241 bool arp_is_waiting(void)
243 return !!net_arp_wait_packet_ip.s_addr;