File:  [Qemu by Fabrice Bellard] / qemu / slirp / arp_table.c
Revision 1.1.1.1 (vendor branch): download - view: text, annotated - select for diffs
Tue Apr 24 19:31:06 2018 UTC (3 years, 3 months ago) by root
Branches: qemu, MAIN
CVS tags: qemu1101, qemu1001, HEAD
qemu 1.0.1

    1: /*
    2:  * ARP table
    3:  *
    4:  * Copyright (c) 2011 AdaCore
    5:  *
    6:  * Permission is hereby granted, free of charge, to any person obtaining a copy
    7:  * of this software and associated documentation files (the "Software"), to deal
    8:  * in the Software without restriction, including without limitation the rights
    9:  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   10:  * copies of the Software, and to permit persons to whom the Software is
   11:  * furnished to do so, subject to the following conditions:
   12:  *
   13:  * The above copyright notice and this permission notice shall be included in
   14:  * all copies or substantial portions of the Software.
   15:  *
   16:  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   17:  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   18:  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
   19:  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   20:  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   21:  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   22:  * THE SOFTWARE.
   23:  */
   24: 
   25: #include "slirp.h"
   26: 
   27: void arp_table_add(Slirp *slirp, uint32_t ip_addr, uint8_t ethaddr[ETH_ALEN])
   28: {
   29:     const uint32_t broadcast_addr =
   30:         ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
   31:     ArpTable *arptbl = &slirp->arp_table;
   32:     int i;
   33: 
   34:     DEBUG_CALL("arp_table_add");
   35:     DEBUG_ARG("ip = 0x%x", ip_addr);
   36:     DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
   37:                 ethaddr[0], ethaddr[1], ethaddr[2],
   38:                 ethaddr[3], ethaddr[4], ethaddr[5]));
   39: 
   40:     /* Check 0.0.0.0/8 invalid source-only addresses */
   41:     assert((ip_addr & htonl(~(0xf << 28))) != 0);
   42: 
   43:     if (ip_addr == 0xffffffff || ip_addr == broadcast_addr) {
   44:         /* Do not register broadcast addresses */
   45:         return;
   46:     }
   47: 
   48:     /* Search for an entry */
   49:     for (i = 0; i < ARP_TABLE_SIZE; i++) {
   50:         if (arptbl->table[i].ar_sip == ip_addr) {
   51:             /* Update the entry */
   52:             memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN);
   53:             return;
   54:         }
   55:     }
   56: 
   57:     /* No entry found, create a new one */
   58:     arptbl->table[arptbl->next_victim].ar_sip = ip_addr;
   59:     memcpy(arptbl->table[arptbl->next_victim].ar_sha,  ethaddr, ETH_ALEN);
   60:     arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE;
   61: }
   62: 
   63: bool arp_table_search(Slirp *slirp, uint32_t ip_addr,
   64:                       uint8_t out_ethaddr[ETH_ALEN])
   65: {
   66:     const uint32_t broadcast_addr =
   67:         ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
   68:     ArpTable *arptbl = &slirp->arp_table;
   69:     int i;
   70: 
   71:     DEBUG_CALL("arp_table_search");
   72:     DEBUG_ARG("ip = 0x%x", ip_addr);
   73: 
   74:     /* Check 0.0.0.0/8 invalid source-only addresses */
   75:     assert((ip_addr & htonl(~(0xf << 28))) != 0);
   76: 
   77:     /* If broadcast address */
   78:     if (ip_addr == 0xffffffff || ip_addr == broadcast_addr) {
   79:         /* return Ethernet broadcast address */
   80:         memset(out_ethaddr, 0xff, ETH_ALEN);
   81:         return 1;
   82:     }
   83: 
   84:     for (i = 0; i < ARP_TABLE_SIZE; i++) {
   85:         if (arptbl->table[i].ar_sip == ip_addr) {
   86:             memcpy(out_ethaddr, arptbl->table[i].ar_sha,  ETH_ALEN);
   87:             DEBUG_ARGS((dfd, " found hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
   88:                         out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
   89:                         out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]));
   90:             return 1;
   91:         }
   92:     }
   93: 
   94:     return 0;
   95: }

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