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/* SPDX-License-Identifier: MIT */
/*
* ARP table
*
* Copyright (c) 2011 AdaCore
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "slirp.h"
#include <string.h>
void arp_table_add(Slirp *slirp, uint32_t ip_addr,
const uint8_t ethaddr[ETH_ALEN])
{
const uint32_t broadcast_addr =
~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
ArpTable *arptbl = &slirp->arp_table;
int i;
char ethaddr_str[ETH_ADDRSTRLEN];
char addr[INET_ADDRSTRLEN];
DEBUG_CALL("arp_table_add");
DEBUG_ARG("ip = %s", inet_ntop(AF_INET, &(struct in_addr){ .s_addr = ip_addr },
addr, sizeof(addr)));
DEBUG_ARG("hw addr = %s", slirp_ether_ntoa(ethaddr, ethaddr_str,
sizeof(ethaddr_str)));
if (ip_addr == 0 || ip_addr == 0xffffffff || ip_addr == broadcast_addr) {
/* Do not register broadcast addresses */
return;
}
/* Search for an entry */
for (i = 0; i < ARP_TABLE_SIZE; i++) {
if (arptbl->table[i].ar_sip == ip_addr) {
/* Update the entry */
memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN);
return;
}
}
/* No entry found, create a new one */
arptbl->table[arptbl->next_victim].ar_sip = ip_addr;
memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN);
arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE;
}
bool arp_table_search(Slirp *slirp, uint32_t ip_addr,
uint8_t out_ethaddr[ETH_ALEN])
{
const uint32_t broadcast_addr =
~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
ArpTable *arptbl = &slirp->arp_table;
int i;
char ethaddr_str[ETH_ADDRSTRLEN];
char addr[INET_ADDRSTRLEN];
DEBUG_CALL("arp_table_search");
DEBUG_ARG("ip = %s", inet_ntop(AF_INET, &(struct in_addr){ .s_addr = ip_addr },
addr, sizeof(addr)));
/* If broadcast address */
if (ip_addr == 0 || ip_addr == 0xffffffff || ip_addr == broadcast_addr) {
/* return Ethernet broadcast address */
memset(out_ethaddr, 0xff, ETH_ALEN);
return 1;
}
for (i = 0; i < ARP_TABLE_SIZE; i++) {
if (arptbl->table[i].ar_sip == ip_addr) {
memcpy(out_ethaddr, arptbl->table[i].ar_sha, ETH_ALEN);
DEBUG_ARG("found hw addr = %s",
slirp_ether_ntoa(out_ethaddr, ethaddr_str,
sizeof(ethaddr_str)));
return 1;
}
}
return 0;
}