text: /*
   * 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 = 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]));
  
      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 = 0x%x", 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;
  }
  