This patch adds a simple ARP table in Slirp and also adds handling of gratuitous ARP requests. Signed-off-by: Fabien Chouteau <chouteau@adacore.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
96 lines
3.4 KiB
C
96 lines
3.4 KiB
C
/*
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* ARP table
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*
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* Copyright (c) 2011 AdaCore
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "slirp.h"
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void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN])
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{
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const in_addr_t broadcast_addr =
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~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
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ArpTable *arptbl = &slirp->arp_table;
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int i;
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DEBUG_CALL("arp_table_add");
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DEBUG_ARG("ip = 0x%x", ip_addr);
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DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
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ethaddr[0], ethaddr[1], ethaddr[2],
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ethaddr[3], ethaddr[4], ethaddr[5]));
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/* Check 0.0.0.0/8 invalid source-only addresses */
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assert((ip_addr & htonl(~(0xf << 28))) != 0);
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if (ip_addr == 0xffffffff || ip_addr == broadcast_addr) {
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/* Do not register broadcast addresses */
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return;
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}
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/* Search for an entry */
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for (i = 0; i < ARP_TABLE_SIZE; i++) {
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if (arptbl->table[i].ar_sip == ip_addr) {
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/* Update the entry */
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memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN);
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return;
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}
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}
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/* No entry found, create a new one */
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arptbl->table[arptbl->next_victim].ar_sip = ip_addr;
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memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN);
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arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE;
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}
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bool arp_table_search(Slirp *slirp, int in_ip_addr,
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uint8_t out_ethaddr[ETH_ALEN])
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{
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const in_addr_t broadcast_addr =
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~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
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ArpTable *arptbl = &slirp->arp_table;
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int i;
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DEBUG_CALL("arp_table_search");
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DEBUG_ARG("ip = 0x%x", in_ip_addr);
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/* Check 0.0.0.0/8 invalid source-only addresses */
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assert((in_ip_addr & htonl(~(0xf << 28))) != 0);
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/* If broadcast address */
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if (in_ip_addr == 0xffffffff || in_ip_addr == broadcast_addr) {
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/* return Ethernet broadcast address */
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memset(out_ethaddr, 0xff, ETH_ALEN);
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return 1;
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}
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for (i = 0; i < ARP_TABLE_SIZE; i++) {
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if (arptbl->table[i].ar_sip == in_ip_addr) {
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memcpy(out_ethaddr, arptbl->table[i].ar_sha, ETH_ALEN);
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DEBUG_ARGS((dfd, " found hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
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out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
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out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]));
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return 1;
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}
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}
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return 0;
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}
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