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-rw-r--r--slirp/arp_table.c95
1 files changed, 95 insertions, 0 deletions
diff --git a/slirp/arp_table.c b/slirp/arp_table.c
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+++ b/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 "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;
+}