slirp/ndp_table.c

   1 /*
   2  * Copyright (c) 2013
   3  * Guillaume Subiron, Yann Bordenave, Serigne Modou Wagne.
   4  */
   5
   6 #include "slirp.h"
   7
   8 void ndp_table_add(Slirp *slirp, struct in6_addr ip_addr,
   9                     uint8_t ethaddr[ETH_ALEN])
  10 {
  11     char addrstr[INET6_ADDRSTRLEN];
  12     NdpTable *ndp_table = &slirp->ndp_table;
  13     int i;
  14
  15     inet_ntop(AF_INET6, &(ip_addr), addrstr, INET6_ADDRSTRLEN);
  16
  17     DEBUG_CALL("ndp_table_add");
  18     DEBUG_ARG("ip = %s", addrstr);
  19     DEBUG_ARG("hw addr = %02x:%02x:%02x:%02x:%02x:%02x",
  20               ethaddr[0], ethaddr[1], ethaddr[2],
  21               ethaddr[3], ethaddr[4], ethaddr[5]);
  22
  23     if (IN6_IS_ADDR_MULTICAST(&ip_addr) || in6_zero(&ip_addr)) {
  24         /* Do not register multicast or unspecified addresses */
  25         DEBUG_CALL(" abort: do not register multicast or unspecified address");
  26         return;
  27     }
  28
  29     /* Search for an entry */
  30     for (i = 0; i < NDP_TABLE_SIZE; i++) {
  31         if (in6_equal(&ndp_table->table[i].ip_addr, &ip_addr)) {
  32             DEBUG_CALL(" already in table: update the entry");
  33             /* Update the entry */
  34             memcpy(ndp_table->table[i].eth_addr, ethaddr, ETH_ALEN);
  35             return;
  36         }
  37     }
  38
  39     /* No entry found, create a new one */
  40     DEBUG_CALL(" create new entry");
  41     ndp_table->table[ndp_table->next_victim].ip_addr = ip_addr;
  42     memcpy(ndp_table->table[ndp_table->next_victim].eth_addr,
  43             ethaddr, ETH_ALEN);
  44     ndp_table->next_victim = (ndp_table->next_victim + 1) % NDP_TABLE_SIZE;
  45 }
  46
  47 bool ndp_table_search(Slirp *slirp, struct in6_addr ip_addr,
  48                       uint8_t out_ethaddr[ETH_ALEN])
  49 {
  50     char addrstr[INET6_ADDRSTRLEN];
  51     NdpTable *ndp_table = &slirp->ndp_table;
  52     int i;
  53
  54     inet_ntop(AF_INET6, &(ip_addr), addrstr, INET6_ADDRSTRLEN);
  55
  56     DEBUG_CALL("ndp_table_search");
  57     DEBUG_ARG("ip = %s", addrstr);
  58
  59     assert(!in6_zero(&ip_addr));
  60
  61     /* Multicast address: fec0::abcd:efgh/8 -> 33:33:ab:cd:ef:gh */
  62     if (IN6_IS_ADDR_MULTICAST(&ip_addr)) {
  63         out_ethaddr[0] = 0x33; out_ethaddr[1] = 0x33;
  64         out_ethaddr[2] = ip_addr.s6_addr[12];
  65         out_ethaddr[3] = ip_addr.s6_addr[13];
  66         out_ethaddr[4] = ip_addr.s6_addr[14];
  67         out_ethaddr[5] = ip_addr.s6_addr[15];
  68         DEBUG_ARG("multicast addr = %02x:%02x:%02x:%02x:%02x:%02x",
  69                   out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
  70                   out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]);
  71         return 1;
  72     }
  73
  74     for (i = 0; i < NDP_TABLE_SIZE; i++) {
  75         if (in6_equal(&ndp_table->table[i].ip_addr, &ip_addr)) {
  76             memcpy(out_ethaddr, ndp_table->table[i].eth_addr,  ETH_ALEN);
  77             DEBUG_ARG("found hw addr = %02x:%02x:%02x:%02x:%02x:%02x",
  78                       out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
  79                       out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]);
  80             return 1;
  81         }
  82     }
  83
  84     DEBUG_CALL(" ip not found in table");
  85     return 0;
  86 }