/* * 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; }