Archipelago » qemu

/*

 * 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"

void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN])

{

    const in_addr_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 = 0x%x", 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]));

    /* Check 0.0.0.0/8 invalid source-only addresses */

    assert((ip_addr & htonl(~(0xf << 28))) != 0);

    if (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, int in_ip_addr,

                      uint8_t out_ethaddr[ETH_ALEN])

{

    const in_addr_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 = 0x%x", in_ip_addr);

    /* Check 0.0.0.0/8 invalid source-only addresses */

    assert((in_ip_addr & htonl(~(0xf << 28))) != 0);

    /* If broadcast address */

    if (in_ip_addr == 0xffffffff || in_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 == in_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;

}