2 * Copied from Linux Monitor (LiMon) - Networking.
4 * Copyright 1994 - 2000 Neil Russell.
6 * Copyright 2000 Roland Borde
7 * Copyright 2000 Paolo Scaffardi
8 * Copyright 2000-2002 Wolfgang Denk, wd@denx.de
9 * SPDX-License-Identifier: GPL-2.0
16 #ifndef CONFIG_ARP_TIMEOUT
17 /* Milliseconds before trying ARP again */
18 # define ARP_TIMEOUT 5000UL
20 # define ARP_TIMEOUT CONFIG_ARP_TIMEOUT
24 #ifndef CONFIG_NET_RETRY_COUNT
25 # define ARP_TIMEOUT_COUNT 5 /* # of timeouts before giving up */
27 # define ARP_TIMEOUT_COUNT CONFIG_NET_RETRY_COUNT
30 struct in_addr net_arp_wait_packet_ip
;
31 static struct in_addr net_arp_wait_reply_ip
;
32 /* MAC address of waiting packet's destination */
33 uchar
*arp_wait_packet_ethaddr
;
34 int arp_wait_tx_packet_size
;
35 ulong arp_wait_timer_start
;
38 static uchar
*arp_tx_packet
; /* THE ARP transmit packet */
39 static uchar arp_tx_packet_buf
[PKTSIZE_ALIGN
+ PKTALIGN
];
43 /* XXX problem with bss workaround */
44 arp_wait_packet_ethaddr
= NULL
;
45 net_arp_wait_packet_ip
.s_addr
= 0;
46 net_arp_wait_reply_ip
.s_addr
= 0;
47 arp_wait_tx_packet_size
= 0;
48 arp_tx_packet
= &arp_tx_packet_buf
[0] + (PKTALIGN
- 1);
49 arp_tx_packet
-= (ulong
)arp_tx_packet
% PKTALIGN
;
52 void arp_raw_request(struct in_addr source_ip
, const uchar
*target_ethaddr
,
53 struct in_addr target_ip
)
59 debug_cond(DEBUG_DEV_PKT
, "ARP broadcast %d\n", arp_wait_try
);
63 eth_hdr_size
= net_set_ether(pkt
, net_bcast_ethaddr
, PROT_ARP
);
66 arp
= (struct arp_hdr
*)pkt
;
68 arp
->ar_hrd
= htons(ARP_ETHER
);
69 arp
->ar_pro
= htons(PROT_IP
);
70 arp
->ar_hln
= ARP_HLEN
;
71 arp
->ar_pln
= ARP_PLEN
;
72 arp
->ar_op
= htons(ARPOP_REQUEST
);
74 memcpy(&arp
->ar_sha
, net_ethaddr
, ARP_HLEN
); /* source ET addr */
75 net_write_ip(&arp
->ar_spa
, source_ip
); /* source IP addr */
76 memcpy(&arp
->ar_tha
, target_ethaddr
, ARP_HLEN
); /* target ET addr */
77 net_write_ip(&arp
->ar_tpa
, target_ip
); /* target IP addr */
79 net_send_packet(arp_tx_packet
, eth_hdr_size
+ ARP_HDR_SIZE
);
82 void arp_request(void)
84 if ((net_arp_wait_packet_ip
.s_addr
& net_netmask
.s_addr
) !=
85 (net_ip
.s_addr
& net_netmask
.s_addr
)) {
86 if (net_gateway
.s_addr
== 0) {
87 puts("## Warning: gatewayip needed but not set\n");
88 net_arp_wait_reply_ip
= net_arp_wait_packet_ip
;
90 net_arp_wait_reply_ip
= net_gateway
;
93 net_arp_wait_reply_ip
= net_arp_wait_packet_ip
;
96 arp_raw_request(net_ip
, net_null_ethaddr
, net_arp_wait_reply_ip
);
99 int arp_timeout_check(void)
103 if (!net_arp_wait_packet_ip
.s_addr
)
108 /* check for arp timeout */
109 if ((t
- arp_wait_timer_start
) > ARP_TIMEOUT
) {
112 if (arp_wait_try
>= ARP_TIMEOUT_COUNT
) {
113 puts("\nARP Retry count exceeded; starting again\n");
115 net_set_state(NETLOOP_FAIL
);
117 arp_wait_timer_start
= t
;
124 void arp_receive(struct ethernet_hdr
*et
, struct ip_udp_hdr
*ip
, int len
)
127 struct in_addr reply_ip_addr
;
132 * We have to deal with two types of ARP packets:
133 * - REQUEST packets will be answered by sending our
134 * IP address - if we know it.
135 * - REPLY packates are expected only after we asked
136 * for the TFTP server's or the gateway's ethernet
137 * address; so if we receive such a packet, we set
138 * the server ethernet address
140 debug_cond(DEBUG_NET_PKT
, "Got ARP\n");
142 arp
= (struct arp_hdr
*)ip
;
143 if (len
< ARP_HDR_SIZE
) {
144 printf("bad length %d < %d\n", len
, ARP_HDR_SIZE
);
147 if (ntohs(arp
->ar_hrd
) != ARP_ETHER
)
149 if (ntohs(arp
->ar_pro
) != PROT_IP
)
151 if (arp
->ar_hln
!= ARP_HLEN
)
153 if (arp
->ar_pln
!= ARP_PLEN
)
156 if (net_ip
.s_addr
== 0)
159 if (net_read_ip(&arp
->ar_tpa
).s_addr
!= net_ip
.s_addr
)
162 switch (ntohs(arp
->ar_op
)) {
164 /* reply with our IP address */
165 debug_cond(DEBUG_DEV_PKT
, "Got ARP REQUEST, return our IP\n");
167 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 net_send_packet((uchar
*)et
, eth_hdr_size
+ ARP_HDR_SIZE
);
191 case ARPOP_REPLY
: /* arp reply */
192 /* are we waiting for a reply */
193 if (!net_arp_wait_packet_ip
.s_addr
)
196 #ifdef CONFIG_KEEP_SERVERADDR
197 if (net_server_ip
.s_addr
== net_arp_wait_packet_ip
.s_addr
) {
199 sprintf(buf
, "%pM", &arp
->ar_sha
);
200 setenv("serveraddr", buf
);
204 reply_ip_addr
= net_read_ip(&arp
->ar_spa
);
206 /* matched waiting packet's address */
207 if (reply_ip_addr
.s_addr
== net_arp_wait_reply_ip
.s_addr
) {
208 debug_cond(DEBUG_DEV_PKT
,
209 "Got ARP REPLY, set eth addr (%pM)\n",
212 /* save address for later use */
213 if (arp_wait_packet_ethaddr
!= NULL
)
214 memcpy(arp_wait_packet_ethaddr
,
215 &arp
->ar_sha
, ARP_HLEN
);
217 net_get_arp_handler()((uchar
*)arp
, 0, reply_ip_addr
,
220 /* set the mac address in the waiting packet's header
222 memcpy(((struct ethernet_hdr
*)net_tx_packet
)->et_dest
,
223 &arp
->ar_sha
, ARP_HLEN
);
224 net_send_packet(net_tx_packet
, arp_wait_tx_packet_size
);
226 /* no arp request pending now */
227 net_arp_wait_packet_ip
.s_addr
= 0;
228 arp_wait_tx_packet_size
= 0;
229 arp_wait_packet_ethaddr
= NULL
;
233 debug("Unexpected ARP opcode 0x%x\n",