xref: /freebsd/contrib/bsnmp/snmp_mibII/mibII_nettomedia.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*
2  * Copyright (c) 2001-2003
3  *	Fraunhofer Institute for Open Communication Systems (FhG Fokus).
4  *	All rights reserved.
5  *
6  * Author: Harti Brandt <harti@freebsd.org>
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
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 the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY AUTHOR 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 AUTHOR 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  * $Begemot: bsnmp/snmp_mibII/mibII_nettomedia.c,v 1.8 2004/08/06 08:47:03 brandt Exp $
30  *
31  * Read-only implementation of the Arp table (ipNetToMediaTable)
32  *
33  * The problem with the table is, that we don't receive routing message
34  * when a) an arp table entry is resolved and b) when an arp table entry is
35  * deleted automatically. Therefor we need to poll the table from time to
36  * time.
37  */
38 #include "mibII.h"
39 #include "mibII_oid.h"
40 
41 #define ARPREFRESH	30
42 
43 struct mibarp *
44 mib_find_arp(const struct mibif *ifp, struct in_addr in)
45 {
46 	struct mibarp *at;
47 	uint32_t a = ntohl(in.s_addr);
48 
49 	if (get_ticks() >= mibarpticks + ARPREFRESH)
50 		mib_arp_update();
51 
52 	TAILQ_FOREACH(at, &mibarp_list, link)
53 		if (at->index.subs[0] == ifp->index &&
54 		    (at->index.subs[1] == ((a >> 24) & 0xff)) &&
55 		    (at->index.subs[2] == ((a >> 16) & 0xff)) &&
56 		    (at->index.subs[3] == ((a >>  8) & 0xff)) &&
57 		    (at->index.subs[4] == ((a >>  0) & 0xff)))
58 			return (at);
59 	return (NULL);
60 }
61 
62 struct mibarp *
63 mib_arp_create(const struct mibif *ifp, struct in_addr in, const u_char *phys,
64     size_t physlen)
65 {
66 	struct mibarp *at;
67 	uint32_t a = ntohl(in.s_addr);
68 
69 	if ((at = malloc(sizeof(*at))) == NULL)
70 		return (NULL);
71 	at->flags = 0;
72 
73 	at->index.len = 5;
74 	at->index.subs[0] = ifp->index;
75 	at->index.subs[1] = (a >> 24) & 0xff;
76 	at->index.subs[2] = (a >> 16) & 0xff;
77 	at->index.subs[3] = (a >>  8) & 0xff;
78 	at->index.subs[4] = (a >>  0) & 0xff;
79 	if ((at->physlen = physlen) > sizeof(at->phys))
80 		at->physlen = sizeof(at->phys);
81 	memcpy(at->phys, phys, at->physlen);
82 
83 	INSERT_OBJECT_OID(at, &mibarp_list);
84 
85 	return (at);
86 }
87 
88 void
89 mib_arp_delete(struct mibarp *at)
90 {
91 	TAILQ_REMOVE(&mibarp_list, at, link);
92 	free(at);
93 }
94 
95 int
96 op_nettomedia(struct snmp_context *ctx __unused, struct snmp_value *value,
97     u_int sub, u_int iidx __unused, enum snmp_op op)
98 {
99 	struct mibarp *at;
100 
101 	at = NULL;	/* gcc */
102 
103 	if (get_ticks() >= mibarpticks + ARPREFRESH)
104 		mib_arp_update();
105 
106 	switch (op) {
107 
108 	  case SNMP_OP_GETNEXT:
109 		if ((at = NEXT_OBJECT_OID(&mibarp_list, &value->var, sub)) == NULL)
110 			return (SNMP_ERR_NOSUCHNAME);
111 		index_append(&value->var, sub, &at->index);
112 		break;
113 
114 	  case SNMP_OP_GET:
115 		if ((at = FIND_OBJECT_OID(&mibarp_list, &value->var, sub)) == NULL)
116 			return (SNMP_ERR_NOSUCHNAME);
117 		break;
118 
119 	  case SNMP_OP_SET:
120 		if ((at = FIND_OBJECT_OID(&mibarp_list, &value->var, sub)) == NULL)
121 			return (SNMP_ERR_NO_CREATION);
122 		return (SNMP_ERR_NOT_WRITEABLE);
123 
124 	  case SNMP_OP_ROLLBACK:
125 	  case SNMP_OP_COMMIT:
126 		abort();
127 	}
128 
129 	switch (value->var.subs[sub - 1]) {
130 
131 	  case LEAF_ipNetToMediaIfIndex:
132 		value->v.integer = at->index.subs[0];
133 		break;
134 
135 	  case LEAF_ipNetToMediaPhysAddress:
136 		return (string_get(value, at->phys, at->physlen));
137 
138 	  case LEAF_ipNetToMediaNetAddress:
139 		value->v.ipaddress[0] = at->index.subs[1];
140 		value->v.ipaddress[1] = at->index.subs[2];
141 		value->v.ipaddress[2] = at->index.subs[3];
142 		value->v.ipaddress[3] = at->index.subs[4];
143 		break;
144 
145 	  case LEAF_ipNetToMediaType:
146 		value->v.integer = (at->flags & MIBARP_PERM) ? 4 : 3;
147 		break;
148 	}
149 	return (SNMP_ERR_NOERROR);
150 }
151