diff options
Diffstat (limited to 'slirp/arp_table.c')
-rw-r--r-- | slirp/arp_table.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/slirp/arp_table.c b/slirp/arp_table.c new file mode 100644 index 0000000000..820dee22b0 --- /dev/null +++ b/slirp/arp_table.c @@ -0,0 +1,95 @@ +/* + * 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; +} |