linux-user: stack_base is now mandatory on all targets
[qemu.git] / slirp / arp_table.c
1 /*
2 * ARP table
3 *
4 * Copyright (c) 2011 AdaCore
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25 #include "slirp.h"
26
27 void arp_table_add(Slirp *slirp, uint32_t ip_addr, uint8_t ethaddr[ETH_ALEN])
28 {
29 const uint32_t broadcast_addr =
30 ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
31 ArpTable *arptbl = &slirp->arp_table;
32 int i;
33
34 DEBUG_CALL("arp_table_add");
35 DEBUG_ARG("ip = 0x%x", ip_addr);
36 DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
37 ethaddr[0], ethaddr[1], ethaddr[2],
38 ethaddr[3], ethaddr[4], ethaddr[5]));
39
40 /* Check 0.0.0.0/8 invalid source-only addresses */
41 assert((ip_addr & htonl(~(0xf << 28))) != 0);
42
43 if (ip_addr == 0xffffffff || ip_addr == broadcast_addr) {
44 /* Do not register broadcast addresses */
45 return;
46 }
47
48 /* Search for an entry */
49 for (i = 0; i < ARP_TABLE_SIZE; i++) {
50 if (arptbl->table[i].ar_sip == ip_addr) {
51 /* Update the entry */
52 memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN);
53 return;
54 }
55 }
56
57 /* No entry found, create a new one */
58 arptbl->table[arptbl->next_victim].ar_sip = ip_addr;
59 memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN);
60 arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE;
61 }
62
63 bool arp_table_search(Slirp *slirp, uint32_t ip_addr,
64 uint8_t out_ethaddr[ETH_ALEN])
65 {
66 const uint32_t broadcast_addr =
67 ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr;
68 ArpTable *arptbl = &slirp->arp_table;
69 int i;
70
71 DEBUG_CALL("arp_table_search");
72 DEBUG_ARG("ip = 0x%x", ip_addr);
73
74 /* Check 0.0.0.0/8 invalid source-only addresses */
75 assert((ip_addr & htonl(~(0xf << 28))) != 0);
76
77 /* If broadcast address */
78 if (ip_addr == 0xffffffff || ip_addr == broadcast_addr) {
79 /* return Ethernet broadcast address */
80 memset(out_ethaddr, 0xff, ETH_ALEN);
81 return 1;
82 }
83
84 for (i = 0; i < ARP_TABLE_SIZE; i++) {
85 if (arptbl->table[i].ar_sip == ip_addr) {
86 memcpy(out_ethaddr, arptbl->table[i].ar_sha, ETH_ALEN);
87 DEBUG_ARGS((dfd, " found hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n",
88 out_ethaddr[0], out_ethaddr[1], out_ethaddr[2],
89 out_ethaddr[3], out_ethaddr[4], out_ethaddr[5]));
90 return 1;
91 }
92 }
93
94 return 0;
95 }