1 /*
2 * Copyright (c) 2006, Swedish Institute of Computer Science.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the Institute nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * This file is part of the uIP TCP/IP stack
30 *
31 * $Id: uip-neighbor.c,v 1.2 2006/06/12 08:00:30 adam Exp $
32 */
33
34 /**
35 * \file
36 * Database of link-local neighbors, used by IPv6 code and
37 * to be used by a future ARP code rewrite.
38 * \author
39 * Adam Dunkels <[email protected]>
40 */
41
42 #include "uip-neighbor.h"
43
44 #include <string.h>
45
46 #define MAX_TIME 128
47
48 #ifdef UIP_NEIGHBOR_CONF_ENTRIES
49 #define ENTRIES UIP_NEIGHBOR_CONF_ENTRIES
50 #else /* UIP_NEIGHBOR_CONF_ENTRIES */
51 #define ENTRIES 8
52 #endif /* UIP_NEIGHBOR_CONF_ENTRIES */
53
54 struct neighbor_entry {
55 uip_ipaddr_t ipaddr;
56 struct uip_neighbor_addr addr;
57 u8_t time;
58 };
59 static struct neighbor_entry entries[ENTRIES];
60
61 /*---------------------------------------------------------------------------*/
62 void
uip_neighbor_init(void)63 uip_neighbor_init(void)
64 {
65 int i;
66
67 for(i = 0; i < ENTRIES; ++i) {
68 entries[i].time = MAX_TIME;
69 }
70 }
71 /*---------------------------------------------------------------------------*/
72 void
uip_neighbor_periodic(void)73 uip_neighbor_periodic(void)
74 {
75 int i;
76
77 for(i = 0; i < ENTRIES; ++i) {
78 if(entries[i].time < MAX_TIME) {
79 entries[i].time++;
80 }
81 }
82 }
83 /*---------------------------------------------------------------------------*/
84 void
uip_neighbor_add(uip_ipaddr_t ipaddr,struct uip_neighbor_addr * addr)85 uip_neighbor_add(uip_ipaddr_t ipaddr, struct uip_neighbor_addr *addr)
86 {
87 int i, oldest;
88 u8_t oldest_time;
89
90 printf("Adding neighbor with link address %02x:%02x:%02x:%02x:%02x:%02x\n",
91 addr->addr.addr[0], addr->addr.addr[1], addr->addr.addr[2], addr->addr.addr[3],
92 addr->addr.addr[4], addr->addr.addr[5]);
93
94 /* Find the first unused entry or the oldest used entry. */
95 oldest_time = 0;
96 oldest = 0;
97 for(i = 0; i < ENTRIES; ++i) {
98 if(entries[i].time == MAX_TIME) {
99 oldest = i;
100 break;
101 }
102 if(uip_ipaddr_cmp(entries[i].ipaddr, addr)) {
103 oldest = i;
104 break;
105 }
106 if(entries[i].time > oldest_time) {
107 oldest = i;
108 oldest_time = entries[i].time;
109 }
110 }
111
112 /* Use the oldest or first free entry (either pointed to by the
113 "oldest" variable). */
114 entries[oldest].time = 0;
115 uip_ipaddr_copy(entries[oldest].ipaddr, ipaddr);
116 memcpy(&entries[oldest].addr, addr, sizeof(struct uip_neighbor_addr));
117 }
118 /*---------------------------------------------------------------------------*/
119 static struct neighbor_entry *
find_entry(uip_ipaddr_t ipaddr)120 find_entry(uip_ipaddr_t ipaddr)
121 {
122 int i;
123
124 for(i = 0; i < ENTRIES; ++i) {
125 if(uip_ipaddr_cmp(entries[i].ipaddr, ipaddr)) {
126 return &entries[i];
127 }
128 }
129 return NULL;
130 }
131 /*---------------------------------------------------------------------------*/
132 void
uip_neighbor_update(uip_ipaddr_t ipaddr)133 uip_neighbor_update(uip_ipaddr_t ipaddr)
134 {
135 struct neighbor_entry *e;
136
137 e = find_entry(ipaddr);
138 if(e != NULL) {
139 e->time = 0;
140 }
141 }
142 /*---------------------------------------------------------------------------*/
143 struct uip_neighbor_addr *
uip_neighbor_lookup(uip_ipaddr_t ipaddr)144 uip_neighbor_lookup(uip_ipaddr_t ipaddr)
145 {
146 struct neighbor_entry *e;
147
148 e = find_entry(ipaddr);
149 if(e != NULL) {
150 /* printf("Lookup neighbor with link address %02x:%02x:%02x:%02x:%02x:%02x\n",
151 e->addr.addr.addr[0], e->addr.addr.addr[1], e->addr.addr.addr[2], e->addr.addr.addr[3],
152 e->addr.addr.addr[4], e->addr.addr.addr[5]);*/
153
154 return &e->addr;
155 }
156 return NULL;
157 }
158 /*---------------------------------------------------------------------------*/
159