1 /*
2 * Copyright (c) 2008 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * $DragonFly: src/usr.sbin/vknetd/mac.c,v 1.1 2008/05/27 01:58:01 dillon Exp $
35 */
36 /*
37 * Bridging code (serialized)
38 */
39 #include "vknetd.h"
40
41 static struct mac_list LRUList = TAILQ_HEAD_INITIALIZER(LRUList);
42 static mac_t MacHash[MAC_HSIZE];
43
44 void
mac_init(void)45 mac_init(void)
46 {
47 static struct mac MacAry[NMACS];
48 int i;
49
50 for (i = 0; i < NMACS; ++i)
51 TAILQ_INSERT_TAIL(&LRUList, &MacAry[i], lru_entry);
52 }
53
54 static __inline int
machash(u_int8_t * macbuf)55 machash(u_int8_t *macbuf)
56 {
57 int hv;
58
59 hv = macbuf[0] ^ (macbuf[1] << 1) ^ (macbuf[2] << 2) ^
60 (macbuf[3] << 3) ^ (macbuf[4] << 4) ^ (macbuf[5] << 5);
61 return(hv & MAC_HMASK);
62 }
63
64 /*
65 * Locate a cached MAC address, return NULL if we do not have it cached.
66 * The MAC is moved to the head of the LRU list.
67 */
68 mac_t
mac_find(u_int8_t * macbuf)69 mac_find(u_int8_t *macbuf)
70 {
71 mac_t scan;
72
73 for (scan = MacHash[machash(macbuf)]; scan; scan = scan->mac_next) {
74 if (bcmp(macbuf, scan->macbuf, 6) == 0) {
75 if (TAILQ_FIRST(&LRUList) != scan) {
76 TAILQ_REMOVE(&LRUList, scan, lru_entry);
77 TAILQ_INSERT_HEAD(&LRUList, scan, lru_entry);
78 }
79 return(scan);
80 }
81 }
82 return(NULL);
83 }
84
85 /*
86 * Create a bridge association for a MAC address. The caller must
87 * have already deleted any pre-existing association.
88 */
89 void
mac_add(bridge_t bridge,u_int8_t * macbuf)90 mac_add(bridge_t bridge, u_int8_t *macbuf)
91 {
92 mac_t *hashp;
93 mac_t mac;
94
95 /*
96 * Recycle least recently used MAC
97 */
98 mac = TAILQ_LAST(&LRUList, mac_list);
99 if (mac->bridge)
100 mac_delete(mac);
101
102 /*
103 * Create the bridge assocation and enter the MAC into the hash
104 * table.
105 */
106 bcopy(macbuf, mac->macbuf, 6);
107 TAILQ_INSERT_TAIL(&bridge->mac_list, mac, bridge_entry);
108
109 hashp = &MacHash[machash(mac->macbuf)];
110 mac->mac_next = *hashp;
111 *hashp = mac;
112
113 mac->bridge = bridge;
114
115 /*
116 * We don't want to recycle the MAC any time soon.
117 */
118 TAILQ_REMOVE(&LRUList, mac, lru_entry);
119 TAILQ_INSERT_HEAD(&LRUList, mac, lru_entry);
120 }
121
122 /*
123 * Delete a MAC's bridge assocation
124 */
125 void
mac_delete(mac_t mac)126 mac_delete(mac_t mac)
127 {
128 mac_t *hashp;
129
130 /*
131 * Remove the bridge linkage
132 */
133 TAILQ_REMOVE(&mac->bridge->mac_list, mac, bridge_entry);
134 mac->bridge = NULL;
135
136 /*
137 * Remove the MAC hash linkage
138 */
139 hashp = &MacHash[machash(mac->macbuf)];
140 while (*hashp != mac) {
141 assert(*hashp);
142 hashp = &(*hashp)->mac_next;
143 }
144 *hashp = mac->mac_next;
145
146 /*
147 * This MAC is now unused, place on end of LRU list.
148 */
149 TAILQ_REMOVE(&LRUList, mac, lru_entry);
150 TAILQ_INSERT_TAIL(&LRUList, mac, lru_entry);
151 }
152
153 /*
154 * Return non-zero if this is a broadcast MAC
155 */
156 int
mac_broadcast(u_int8_t * macbuf)157 mac_broadcast(u_int8_t *macbuf)
158 {
159 if (macbuf[0] == 0 && macbuf[1] == 0 && macbuf[2] == 0 &&
160 macbuf[3] == 0 && macbuf[4] == 0 && macbuf[5] == 0) {
161 return(1);
162 }
163 if (macbuf[0] == 0xFF && macbuf[1] == 0xFF && macbuf[2] == 0xFF &&
164 macbuf[3] == 0xFF && macbuf[4] == 0xFF && macbuf[5] == 0xFF) {
165 return(1);
166 }
167 return(0);
168 }
169
170