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// SPDX-License-Identifier: GPL-2.0
/*
* Copied from Linux Monitor (LiMon) - Networking.
*
* Copyright 1994 - 2000 Neil Russell.
* (See License)
* Copyright 2000 Roland Borde
* Copyright 2000 Paolo Scaffardi
* Copyright 2000-2002 Wolfgang Denk, wd@denx.de
*/
#include <common.h>
#include <env.h>
#include <log.h>
#include <net.h>
#include "arp.h"
#ifndef CONFIG_ARP_TIMEOUT
/* Milliseconds before trying ARP again */
# define ARP_TIMEOUT 5000UL
#else
# define ARP_TIMEOUT CONFIG_ARP_TIMEOUT
#endif
#ifndef CONFIG_NET_RETRY_COUNT
# define ARP_TIMEOUT_COUNT 5 /* # of timeouts before giving up */
#else
# define ARP_TIMEOUT_COUNT CONFIG_NET_RETRY_COUNT
#endif
struct in_addr net_arp_wait_packet_ip;
static struct in_addr net_arp_wait_reply_ip;
/* MAC address of waiting packet's destination */
uchar *arp_wait_packet_ethaddr;
int arp_wait_tx_packet_size;
ulong arp_wait_timer_start;
int arp_wait_try;
uchar *arp_tx_packet; /* THE ARP transmit packet */
static uchar arp_tx_packet_buf[PKTSIZE_ALIGN + PKTALIGN];
void arp_init(void)
{
/* XXX problem with bss workaround */
arp_wait_packet_ethaddr = NULL;
net_arp_wait_packet_ip.s_addr = 0;
net_arp_wait_reply_ip.s_addr = 0;
arp_wait_tx_packet_size = 0;
arp_tx_packet = &arp_tx_packet_buf[0] + (PKTALIGN - 1);
arp_tx_packet -= (ulong)arp_tx_packet % PKTALIGN;
}
void arp_raw_request(struct in_addr source_ip, const uchar *target_ethaddr,
struct in_addr target_ip)
{
uchar *pkt;
struct arp_hdr *arp;
int eth_hdr_size;
debug_cond(DEBUG_DEV_PKT, "ARP broadcast %d\n", arp_wait_try);
pkt = arp_tx_packet;
eth_hdr_size = net_set_ether(pkt, net_bcast_ethaddr, PROT_ARP);
pkt += eth_hdr_size;
arp = (struct arp_hdr *)pkt;
arp->ar_hrd = htons(ARP_ETHER);
arp->ar_pro = htons(PROT_IP);
arp->ar_hln = ARP_HLEN;
arp->ar_pln = ARP_PLEN;
arp->ar_op = htons(ARPOP_REQUEST);
memcpy(&arp->ar_sha, net_ethaddr, ARP_HLEN); /* source ET addr */
net_write_ip(&arp->ar_spa, source_ip); /* source IP addr */
memcpy(&arp->ar_tha, target_ethaddr, ARP_HLEN); /* target ET addr */
net_write_ip(&arp->ar_tpa, target_ip); /* target IP addr */
net_send_packet(arp_tx_packet, eth_hdr_size + ARP_HDR_SIZE);
}
void arp_request(void)
{
if ((net_arp_wait_packet_ip.s_addr & net_netmask.s_addr) !=
(net_ip.s_addr & net_netmask.s_addr)) {
if (net_gateway.s_addr == 0) {
puts("## Warning: gatewayip needed but not set\n");
net_arp_wait_reply_ip = net_arp_wait_packet_ip;
} else {
net_arp_wait_reply_ip = net_gateway;
}
} else {
net_arp_wait_reply_ip = net_arp_wait_packet_ip;
}
arp_raw_request(net_ip, net_null_ethaddr, net_arp_wait_reply_ip);
}
int arp_timeout_check(void)
{
ulong t;
if (!arp_is_waiting())
return 0;
t = get_timer(0);
/* check for arp timeout */
if ((t - arp_wait_timer_start) > ARP_TIMEOUT) {
arp_wait_try++;
if (arp_wait_try >= ARP_TIMEOUT_COUNT) {
puts("\nARP Retry count exceeded; starting again\n");
arp_wait_try = 0;
net_set_state(NETLOOP_FAIL);
} else {
arp_wait_timer_start = t;
arp_request();
}
}
return 1;
}
void arp_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len)
{
struct arp_hdr *arp;
struct in_addr reply_ip_addr;
int eth_hdr_size;
uchar *tx_packet;
/*
* We have to deal with two types of ARP packets:
* - REQUEST packets will be answered by sending our
* IP address - if we know it.
* - REPLY packates are expected only after we asked
* for the TFTP server's or the gateway's ethernet
* address; so if we receive such a packet, we set
* the server ethernet address
*/
debug_cond(DEBUG_NET_PKT, "Got ARP\n");
arp = (struct arp_hdr *)ip;
if (len < ARP_HDR_SIZE) {
printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
return;
}
if (ntohs(arp->ar_hrd) != ARP_ETHER)
return;
if (ntohs(arp->ar_pro) != PROT_IP)
return;
if (arp->ar_hln != ARP_HLEN)
return;
if (arp->ar_pln != ARP_PLEN)
return;
if (net_ip.s_addr == 0)
return;
if (net_read_ip(&arp->ar_tpa).s_addr != net_ip.s_addr)
return;
switch (ntohs(arp->ar_op)) {
case ARPOP_REQUEST:
/* reply with our IP address */
debug_cond(DEBUG_DEV_PKT, "Got ARP REQUEST, return our IP\n");
eth_hdr_size = net_update_ether(et, et->et_src, PROT_ARP);
arp->ar_op = htons(ARPOP_REPLY);
memcpy(&arp->ar_tha, &arp->ar_sha, ARP_HLEN);
net_copy_ip(&arp->ar_tpa, &arp->ar_spa);
memcpy(&arp->ar_sha, net_ethaddr, ARP_HLEN);
net_copy_ip(&arp->ar_spa, &net_ip);
#ifdef CONFIG_CMD_LINK_LOCAL
/*
* Work-around for brain-damaged Cisco equipment with
* arp-proxy enabled.
*
* If the requesting IP is not on our subnet, wait 5ms to
* reply to ARP request so that our reply will overwrite
* the arp-proxy's instead of the other way around.
*/
if ((net_read_ip(&arp->ar_tpa).s_addr & net_netmask.s_addr) !=
(net_read_ip(&arp->ar_spa).s_addr & net_netmask.s_addr))
udelay(5000);
#endif
tx_packet = net_get_async_tx_pkt_buf();
memcpy(tx_packet, et, eth_hdr_size + ARP_HDR_SIZE);
net_send_packet(tx_packet, eth_hdr_size + ARP_HDR_SIZE);
return;
case ARPOP_REPLY: /* arp reply */
/* are we waiting for a reply? */
if (!arp_is_waiting())
break;
#ifdef CONFIG_KEEP_SERVERADDR
if (net_server_ip.s_addr == net_arp_wait_packet_ip.s_addr) {
char buf[20];
sprintf(buf, "%pM", &arp->ar_sha);
env_set("serveraddr", buf);
}
#endif
reply_ip_addr = net_read_ip(&arp->ar_spa);
/* matched waiting packet's address */
if (reply_ip_addr.s_addr == net_arp_wait_reply_ip.s_addr) {
debug_cond(DEBUG_DEV_PKT,
"Got ARP REPLY, set eth addr (%pM)\n",
arp->ar_data);
/* save address for later use */
if (arp_wait_packet_ethaddr != NULL)
memcpy(arp_wait_packet_ethaddr,
&arp->ar_sha, ARP_HLEN);
net_get_arp_handler()((uchar *)arp, 0, reply_ip_addr,
0, len);
/* set the mac address in the waiting packet's header
and transmit it */
memcpy(((struct ethernet_hdr *)net_tx_packet)->et_dest,
&arp->ar_sha, ARP_HLEN);
net_send_packet(net_tx_packet, arp_wait_tx_packet_size);
/* no arp request pending now */
net_arp_wait_packet_ip.s_addr = 0;
arp_wait_tx_packet_size = 0;
arp_wait_packet_ethaddr = NULL;
}
return;
default:
debug("Unexpected ARP opcode 0x%x\n",
ntohs(arp->ar_op));
return;
}
}
bool arp_is_waiting(void)
{
return !!net_arp_wait_packet_ip.s_addr;
}
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