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