slirp/ndp_table.c

   1 /*
   2  * Copyright (c) 2013
   3  * Guillaume Subiron, Yann Bordenave, Serigne Modou Wagne.
   4  */
   5
   6 #include "qemu/osdep.h"
   7 #include "qemu-common.h"
   8 #include "slirp.h"
   9
  10 void ndp_table_add(Slirp *slirp, struct in6_addr ip_addr,
  11                     uint8_t ethaddr[ETH_ALEN])
  12 {
  13     char addrstr[INET6_ADDRSTRLEN];
  14     NdpTable *ndp_table = &slirp->ndp_table;
  15     int i;
  16
  17     inet_ntop(AF_INET6, &(ip_addr), addrstr, INET6_ADDRSTRLEN);
  18
  19     DEBUG_CALL("ndp_table_add");
  20     DEBUG_ARG("ip = %s", addrstr);
  21     DEBUG_ARG("hw addr = %02x:%02x:%02x:%02x:%02x:%02x",
  22               ethaddr[0], ethaddr[1], ethaddr[2],
  23               ethaddr[3], ethaddr[4], ethaddr[5]);
  24
  25     if (IN6_IS_ADDR_MULTICAST(&ip_addr) || in6_zero(&ip_addr)) {
  26         /* Do not register multicast or unspecified addresses */
  27         DEBUG_CALL(" abort: do not register multicast or unspecified address");
  28         return;
  29     }
  30
  31     /* Search for an entry */
  32     for (i = 0; i < NDP_TABLE_SIZE; i++) {
  33         if (in6_equal(&ndp_table->table[i].ip_addr, &ip_addr)) {
  34             DEBUG_CALL(" already in table: update the entry");
  35             /* Update the entry */
  36             memcpy(ndp_table->table[i].eth_addr, ethaddr, ETH_ALEN);
  37             return;
  38         }
  39     }
  40
  41     /* No entry found, create a new one */
  42     DEBUG_CALL(" create new entry");
  43     ndp_table->table[ndp_table->next_victim].ip_addr = ip_addr;
  44     memcpy(ndp_table->table[ndp_table->next_victim].eth_addr,
  45             ethaddr, ETH_ALEN);
  46     ndp_table->next_victim = (ndp_table->next_victim + 1) % NDP_TABLE_SIZE;
  47 }
  48
  49 bool ndp_table_search(Slirp *slirp, struct in6_addr ip_addr,
  50                       uint8_t out_ethaddr[ETH_ALEN])
  51 {
  52     char addrstr[INET6_ADDRSTRLEN];
  53     NdpTable *ndp_table = &slirp->ndp_table;
  54     int i;
  55
  56     inet_ntop(AF_INET6, &(ip_addr), addrstr, INET6_ADDRSTRLEN);
  57
  58     DEBUG_CALL("ndp_table_search");
  59     DEBUG_ARG("ip = %s", addrstr);
  60
  61     assert(!in6_zero(&ip_addr));
  62
  63     /* Multicast address: fec0::abcd:efgh/8 -> 33:33:ab:cd:ef:gh */
  64     if (IN6_IS_ADDR_MULTICAST(&ip_addr)) {
  65         out_ethaddr[0] = 0x33; out_ethaddr[1] = 0x33;
  66         out_ethaddr[2] = ip_addr.s6_addr[12];
  67         out_ethaddr[3] = ip_addr.s6_addr[13];
  68         out_ethaddr[4] = ip_addr.s6_addr[14];
  69         out_ethaddr[5] = ip_addr.s6_addr[15];
  70         DEBUG_ARG("multicast addr = %02x:%02x:%02x:%02x:%02x:%02x",
  71                   out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
  72                   out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]);
  73         return 1;
  74     }
  75
  76     for (i = 0; i < NDP_TABLE_SIZE; i++) {
  77         if (in6_equal(&ndp_table->table[i].ip_addr, &ip_addr)) {
  78             memcpy(out_ethaddr, ndp_table->table[i].eth_addr,  ETH_ALEN);
  79             DEBUG_ARG("found hw addr = %02x:%02x:%02x:%02x:%02x:%02x",
  80                       out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
  81                       out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]);
  82             return 1;
  83         }
  84     }
  85
  86     DEBUG_CALL(" ip not found in table");
  87     return 0;
  88 }