1/*-
2 * Copyright (c) 2005-2006 The FreeBSD Project
3 * All rights reserved.
4 *
5 * Author: Victor Cruceru <soc-victor@freebsd.org>
6 *
7 * Redistribution of this software and documentation and use in source and
8 * binary forms, with or without modification, are permitted provided that
9 * the following conditions are met:
10 *
11 * 1. Redistributions of source code or documentation must retain the above
12 *    copyright 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 THE 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 THE 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 * $FreeBSD$
30 */
31
32/*
33 * Host Resources MIB implementation for SNMPd: instrumentation for
34 * hrNetworkTable
35 */
36
37#include <sys/types.h>
38#include <sys/ioctl.h>
39#include <sys/socket.h>
40#include <sys/sysctl.h>
41
42#include <net/if.h>
43#include <net/if_mib.h>
44
45#include <assert.h>
46#include <ctype.h>
47#include <err.h>
48#include <errno.h>
49#include <ifaddrs.h>
50#include <stdarg.h>
51#include <stdlib.h>
52#include <string.h>
53#include <syslog.h>
54#include <unistd.h>
55
56#include "hostres_snmp.h"
57#include "hostres_oid.h"
58#include "hostres_tree.h"
59
60#include <bsnmp/snmp_mibII.h>
61
62/*
63 * This structure is used to hold a SNMP table entry
64 * for HOST-RESOURCES-MIB's hrNetworkTable
65 */
66struct network_entry {
67	int32_t		index;
68	int32_t		ifIndex;
69	TAILQ_ENTRY(network_entry) link;
70#define	HR_NETWORK_FOUND		0x001
71	uint32_t	flags;
72
73};
74TAILQ_HEAD(network_tbl, network_entry);
75
76/* the head of the list with hrNetworkTable's entries */
77static struct network_tbl network_tbl = TAILQ_HEAD_INITIALIZER(network_tbl);
78
79/* last (agent) tick when hrNetworkTable was updated */
80static uint64_t network_tick;
81
82/* maximum number of ticks between updates of network table */
83uint32_t network_tbl_refresh = HR_NETWORK_TBL_REFRESH * 100;
84
85/* Constants */
86static const struct asn_oid OIDX_hrDeviceNetwork_c = OIDX_hrDeviceNetwork;
87
88/**
89 * Create a new entry into the network table
90 */
91static struct network_entry *
92network_entry_create(const struct device_entry *devEntry)
93{
94	struct network_entry *entry;
95
96	assert(devEntry != NULL);
97	if (devEntry == NULL)
98		return (NULL);
99
100	if ((entry = malloc(sizeof(*entry))) == NULL) {
101		syslog(LOG_WARNING, "%s: %m", __func__);
102		return (NULL);
103	}
104
105	memset(entry, 0, sizeof(*entry));
106	entry->index = devEntry->index;
107	INSERT_OBJECT_INT(entry, &network_tbl);
108
109	return (entry);
110}
111
112/**
113 * Delete an entry in the network table
114 */
115static void
116network_entry_delete(struct network_entry* entry)
117{
118
119	TAILQ_REMOVE(&network_tbl, entry, link);
120	free(entry);
121}
122
123/**
124 * Fetch the interfaces from the mibII module, get their real name from the
125 * kernel and try to find it in the device table.
126 */
127static void
128network_get_interfaces(void)
129{
130	struct device_entry *dev;
131	struct network_entry *net;
132	struct mibif *ifp;
133	int name[6];
134	size_t len;
135	char *dname;
136
137	name[0] = CTL_NET;
138	name[1] = PF_LINK;
139	name[2] = NETLINK_GENERIC;
140	name[3] = IFMIB_IFDATA;
141	name[5] = IFDATA_DRIVERNAME;
142
143	for (ifp = mib_first_if(); ifp != NULL; ifp = mib_next_if(ifp)) {
144		HRDBG("%s %s", ifp->name, ifp->descr);
145
146		name[4] = ifp->sysindex;
147
148		/* get the original name */
149		len = 0;
150		if (sysctl(name, 6, NULL, &len, 0, 0) < 0) {
151			syslog(LOG_ERR, "sysctl(net.link.ifdata.%d."
152			    "drivername): %m", ifp->sysindex);
153			continue;
154		}
155		if ((dname = malloc(len)) == NULL) {
156			syslog(LOG_ERR, "malloc: %m");
157			continue;
158		}
159		if (sysctl(name, 6, dname, &len, 0, 0) < 0) {
160			syslog(LOG_ERR, "sysctl(net.link.ifdata.%d."
161			    "drivername): %m", ifp->sysindex);
162			free(dname);
163			continue;
164		}
165
166		HRDBG("got device %s (%s)", ifp->name, dname);
167
168		if ((dev = device_find_by_name(dname)) == NULL) {
169			HRDBG("%s not in hrDeviceTable", dname);
170			free(dname);
171			continue;
172		}
173		HRDBG("%s found in hrDeviceTable", dname);
174
175		dev->type = &OIDX_hrDeviceNetwork_c;
176		dev->flags |= HR_DEVICE_IMMUTABLE;
177
178		free(dname);
179
180		/* Then check hrNetworkTable for this device */
181		TAILQ_FOREACH(net, &network_tbl, link)
182			if (net->index == dev->index)
183				break;
184
185		if (net == NULL && (net = network_entry_create(dev)) == NULL)
186			continue;
187
188		net->flags |= HR_NETWORK_FOUND;
189		net->ifIndex = ifp->index;
190	}
191
192	network_tick = this_tick;
193}
194
195/**
196 * Finalization routine for hrNetworkTable.
197 * It destroys the lists and frees any allocated heap memory.
198 */
199void
200fini_network_tbl(void)
201{
202	struct network_entry *n1;
203
204	while ((n1 = TAILQ_FIRST(&network_tbl)) != NULL) {
205		TAILQ_REMOVE(&network_tbl, n1, link);
206		free(n1);
207	}
208}
209
210/**
211 * Get the interface list from mibII only at this point to be sure that
212 * it is there already.
213 */
214void
215start_network_tbl(void)
216{
217
218	mib_refresh_iflist();
219	network_get_interfaces();
220}
221
222/**
223 * Refresh the table.
224 */
225static void
226refresh_network_tbl(void)
227{
228	struct network_entry *entry, *entry_tmp;
229
230	if (this_tick - network_tick < network_tbl_refresh) {
231		HRDBG("no refresh needed");
232		return;
233	}
234
235	/* mark each entry as missing */
236	TAILQ_FOREACH(entry, &network_tbl, link)
237		entry->flags &= ~HR_NETWORK_FOUND;
238
239	network_get_interfaces();
240
241	/*
242	 * Purge items that disappeared
243	 */
244	TAILQ_FOREACH_SAFE(entry, &network_tbl, link, entry_tmp) {
245		if (!(entry->flags & HR_NETWORK_FOUND))
246			network_entry_delete(entry);
247	}
248
249	HRDBG("refresh DONE");
250}
251
252/*
253 * This is the implementation for a generated (by our SNMP tool)
254 * function prototype, see hostres_tree.h
255 * It handles the SNMP operations for hrNetworkTable
256 */
257int
258op_hrNetworkTable(struct snmp_context *ctx __unused, struct snmp_value *value,
259    u_int sub, u_int iidx __unused, enum snmp_op curr_op)
260{
261	struct network_entry *entry;
262
263	refresh_network_tbl();
264
265	switch (curr_op) {
266
267	case SNMP_OP_GETNEXT:
268		if ((entry = NEXT_OBJECT_INT(&network_tbl,
269		    &value->var, sub)) == NULL)
270			return (SNMP_ERR_NOSUCHNAME);
271		value->var.len = sub + 1;
272		value->var.subs[sub] = entry->index;
273		goto get;
274
275	case SNMP_OP_GET:
276		if ((entry = FIND_OBJECT_INT(&network_tbl,
277		    &value->var, sub)) == NULL)
278			return (SNMP_ERR_NOSUCHNAME);
279		goto get;
280
281	case SNMP_OP_SET:
282		if ((entry = FIND_OBJECT_INT(&network_tbl,
283		    &value->var, sub)) == NULL)
284			return (SNMP_ERR_NO_CREATION);
285		return (SNMP_ERR_NOT_WRITEABLE);
286
287	case SNMP_OP_ROLLBACK:
288	case SNMP_OP_COMMIT:
289		abort();
290	}
291	abort();
292
293  get:
294	switch (value->var.subs[sub - 1]) {
295
296	case LEAF_hrNetworkIfIndex:
297		value->v.integer = entry->ifIndex;
298		return (SNMP_ERR_NOERROR);
299
300	}
301	abort();
302}
303