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 IPaddr_t NetArpWaitPacketIP
;
31 static IPaddr_t NetArpWaitReplyIP
;
32 /* MAC address of waiting packet's destination */
33 uchar
*NetArpWaitPacketMAC
;
34 int NetArpWaitTxPacketSize
;
35 ulong NetArpWaitTimerStart
;
38 static uchar
*NetArpTxPacket
; /* THE ARP transmit packet */
39 static uchar NetArpPacketBuf
[PKTSIZE_ALIGN
+ PKTALIGN
];
43 /* XXX problem with bss workaround */
44 NetArpWaitPacketMAC
= NULL
;
45 NetArpWaitPacketIP
= 0;
46 NetArpWaitReplyIP
= 0;
47 NetArpWaitTxPacketSize
= 0;
48 NetArpTxPacket
= &NetArpPacketBuf
[0] + (PKTALIGN
- 1);
49 NetArpTxPacket
-= (ulong
)NetArpTxPacket
% PKTALIGN
;
52 void arp_raw_request(IPaddr_t sourceIP
, const uchar
*targetEther
,
59 debug_cond(DEBUG_DEV_PKT
, "ARP broadcast %d\n", NetArpWaitTry
);
63 eth_hdr_size
= NetSetEther(pkt
, NetBcastAddr
, 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
, NetOurEther
, ARP_HLEN
); /* source ET addr */
75 NetWriteIP(&arp
->ar_spa
, sourceIP
); /* source IP addr */
76 memcpy(&arp
->ar_tha
, targetEther
, ARP_HLEN
); /* target ET addr */
77 NetWriteIP(&arp
->ar_tpa
, targetIP
); /* target IP addr */
79 NetSendPacket(NetArpTxPacket
, eth_hdr_size
+ ARP_HDR_SIZE
);
84 if ((NetArpWaitPacketIP
& NetOurSubnetMask
) !=
85 (NetOurIP
& NetOurSubnetMask
)) {
86 if (NetOurGatewayIP
== 0) {
87 puts("## Warning: gatewayip needed but not set\n");
88 NetArpWaitReplyIP
= NetArpWaitPacketIP
;
90 NetArpWaitReplyIP
= NetOurGatewayIP
;
93 NetArpWaitReplyIP
= NetArpWaitPacketIP
;
96 arp_raw_request(NetOurIP
, NetEtherNullAddr
, NetArpWaitReplyIP
);
99 void ArpTimeoutCheck(void)
103 if (!NetArpWaitPacketIP
)
108 /* check for arp timeout */
109 if ((t
- NetArpWaitTimerStart
) > ARP_TIMEOUT
) {
112 if (NetArpWaitTry
>= ARP_TIMEOUT_COUNT
) {
113 puts("\nARP Retry count exceeded; starting again\n");
117 NetArpWaitTimerStart
= t
;
123 void ArpReceive(struct ethernet_hdr
*et
, struct ip_udp_hdr
*ip
, int len
)
126 IPaddr_t reply_ip_addr
;
131 * We have to deal with two types of ARP packets:
132 * - REQUEST packets will be answered by sending our
133 * IP address - if we know it.
134 * - REPLY packates are expected only after we asked
135 * for the TFTP server's or the gateway's ethernet
136 * address; so if we receive such a packet, we set
137 * the server ethernet address
139 debug_cond(DEBUG_NET_PKT
, "Got ARP\n");
141 arp
= (struct arp_hdr
*)ip
;
142 if (len
< ARP_HDR_SIZE
) {
143 printf("bad length %d < %d\n", len
, ARP_HDR_SIZE
);
146 if (ntohs(arp
->ar_hrd
) != ARP_ETHER
)
148 if (ntohs(arp
->ar_pro
) != PROT_IP
)
150 if (arp
->ar_hln
!= ARP_HLEN
)
152 if (arp
->ar_pln
!= ARP_PLEN
)
158 if (NetReadIP(&arp
->ar_tpa
) != NetOurIP
)
161 switch (ntohs(arp
->ar_op
)) {
163 /* reply with our IP address */
164 debug_cond(DEBUG_DEV_PKT
, "Got ARP REQUEST, return our IP\n");
166 eth_hdr_size
= net_update_ether(et
, et
->et_src
, PROT_ARP
);
168 arp
->ar_op
= htons(ARPOP_REPLY
);
169 memcpy(&arp
->ar_tha
, &arp
->ar_sha
, ARP_HLEN
);
170 NetCopyIP(&arp
->ar_tpa
, &arp
->ar_spa
);
171 memcpy(&arp
->ar_sha
, NetOurEther
, ARP_HLEN
);
172 NetCopyIP(&arp
->ar_spa
, &NetOurIP
);
174 #ifdef CONFIG_CMD_LINK_LOCAL
176 * Work-around for brain-damaged Cisco equipment with
179 * If the requesting IP is not on our subnet, wait 5ms to
180 * reply to ARP request so that our reply will overwrite
181 * the arp-proxy's instead of the other way around.
183 if ((NetReadIP(&arp
->ar_tpa
) & NetOurSubnetMask
) !=
184 (NetReadIP(&arp
->ar_spa
) & NetOurSubnetMask
))
187 NetSendPacket((uchar
*)et
, eth_hdr_size
+ ARP_HDR_SIZE
);
190 case ARPOP_REPLY
: /* arp reply */
191 /* are we waiting for a reply */
192 if (!NetArpWaitPacketIP
)
195 #ifdef CONFIG_KEEP_SERVERADDR
196 if (NetServerIP
== NetArpWaitPacketIP
) {
198 sprintf(buf
, "%pM", &arp
->ar_sha
);
199 setenv("serveraddr", buf
);
203 reply_ip_addr
= NetReadIP(&arp
->ar_spa
);
205 /* matched waiting packet's address */
206 if (reply_ip_addr
== NetArpWaitReplyIP
) {
207 debug_cond(DEBUG_DEV_PKT
,
208 "Got ARP REPLY, set eth addr (%pM)\n",
211 /* save address for later use */
212 if (NetArpWaitPacketMAC
!= NULL
)
213 memcpy(NetArpWaitPacketMAC
,
214 &arp
->ar_sha
, ARP_HLEN
);
216 net_get_arp_handler()((uchar
*)arp
, 0, reply_ip_addr
,
219 /* set the mac address in the waiting packet's header
221 memcpy(((struct ethernet_hdr
*)NetTxPacket
)->et_dest
,
222 &arp
->ar_sha
, ARP_HLEN
);
223 NetSendPacket(NetTxPacket
, NetArpWaitTxPacketSize
);
225 /* no arp request pending now */
226 NetArpWaitPacketIP
= 0;
227 NetArpWaitTxPacketSize
= 0;
228 NetArpWaitPacketMAC
= NULL
;
233 debug("Unexpected ARP opcode 0x%x\n",