qemu/slirp/arp_table.c

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/*
* 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 "qemu/osdep.h"
#include "slirp.h"
void arp_table_add(Slirp *slirp, uint32_t ip_addr, 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;
DEBUG_CALL("arp_table_add");
DEBUG_ARG("ip = %s", inet_ntoa((struct in_addr){.s_addr = ip_addr}));
DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
ethaddr[0], ethaddr[1], ethaddr[2],
ethaddr[3], ethaddr[4], ethaddr[5]));
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;
DEBUG_CALL("arp_table_search");
DEBUG_ARG("ip = %s", inet_ntoa((struct in_addr){.s_addr = ip_addr}));
/* If broadcast address */
if (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_ARGS((dfd, " found hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]));
return 1;
}
}
return 0;
}