bridge_snmp.c revision 330449 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2006 Shteryana Shopova <syrinx@FreeBSD.org>
5 * All rights reserved.
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 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * Bridge MIB implementation for SNMPd.
29 *
30 * $FreeBSD: stable/11/usr.sbin/bsnmpd/modules/snmp_bridge/bridge_snmp.c 330449 2018-03-05 07:26:05Z eadler $
31 */
32
33#include <sys/param.h>
34#include <sys/queue.h>
35#include <sys/socket.h>
36#include <sys/types.h>
37
38#include <net/ethernet.h>
39#include <net/if.h>
40#include <net/if_mib.h>
41#include <net/if_types.h>
42
43#include <errno.h>
44#include <stdarg.h>
45#include <stdlib.h>
46#include <stdio.h>
47#include <string.h>
48#include <syslog.h>
49
50#include <bsnmp/snmpmod.h>
51#include <bsnmp/snmp_mibII.h>
52
53#include "bridge_tree.h"
54#include "bridge_snmp.h"
55#include "bridge_oid.h"
56
57static struct lmodule *bridge_module;
58
59/* For the registration. */
60static const struct asn_oid oid_dot1Bridge = OIDX_dot1dBridge;
61/* The registration. */
62static uint reg_bridge;
63
64/* Periodic timer for polling all bridges' data. */
65static void *bridge_data_timer;
66static void *bridge_tc_timer;
67
68static int bridge_data_maxage = SNMP_BRIDGE_DATA_MAXAGE;
69static int bridge_poll_ticks = SNMP_BRIDGE_POLL_INTERVAL * 100;
70static int bridge_tc_poll_ticks = SNMP_BRIDGE_TC_POLL_INTERVAL * 100;
71
72/*
73 * Our default bridge, whose info will be visible under
74 * the dot1dBridge subtree and functions to set/fetch it.
75 */
76static char bif_default_name[IFNAMSIZ] = "bridge0";
77static struct bridge_if *bif_default;
78
79struct bridge_if *
80bridge_get_default(void)
81{
82	struct mibif *ifp;
83
84	if (bif_default != NULL) {
85
86		/* Walk through the mibII interface list. */
87		for (ifp = mib_first_if(); ifp != NULL; ifp = mib_next_if(ifp))
88			if (strcmp(ifp->name, bif_default->bif_name) == 0)
89				break;
90
91		if (ifp == NULL)
92			bif_default = NULL;
93	}
94
95	return (bif_default);
96}
97
98void
99bridge_set_default(struct bridge_if *bif)
100{
101	bif_default = bif;
102
103	syslog(LOG_ERR, "Set default bridge interface to: %s",
104	    bif == NULL ? "(none)" : bif->bif_name);
105}
106
107const char *
108bridge_get_default_name(void)
109{
110	return (bif_default_name);
111}
112
113static int
114bridge_set_default_name(const char *bif_name, uint len)
115{
116	struct bridge_if *bif;
117
118	if (len >= IFNAMSIZ)
119		return (-1);
120
121	bcopy(bif_name, bif_default_name, len);
122	bif_default_name[len] = '\0';
123
124	if ((bif = bridge_if_find_ifname(bif_default_name)) == NULL) {
125		bif_default = NULL;
126		return (0);
127	}
128
129	bif_default = bif;
130	return (1);
131}
132
133int
134bridge_get_data_maxage(void)
135{
136	return (bridge_data_maxage);
137}
138
139static void
140bridge_set_poll_ticks(int poll_ticks)
141{
142	if (bridge_data_timer != NULL)
143		timer_stop(bridge_data_timer);
144
145	bridge_poll_ticks = poll_ticks;
146	bridge_data_timer = timer_start_repeat(bridge_poll_ticks,
147	    bridge_poll_ticks, bridge_update_all, NULL, bridge_module);
148}
149/*
150 * The bridge module configuration via SNMP.
151 */
152static int
153bridge_default_name_save(struct snmp_context *ctx, const char *bridge_default)
154{
155	if ((ctx->scratch->int1 = strlen(bridge_default)) >= IFNAMSIZ)
156		return (-1);
157
158	if ((ctx->scratch->ptr1 = malloc(IFNAMSIZ)) == NULL)
159		return (-1);
160
161	strncpy(ctx->scratch->ptr1, bridge_default, ctx->scratch->int1);
162	return (0);
163}
164
165int
166op_begemot_bridge_config(struct snmp_context *ctx, struct snmp_value *val,
167    uint sub, uint iidx __unused, enum snmp_op op)
168{
169	switch (op) {
170	    case SNMP_OP_GET:
171		switch (val->var.subs[sub - 1]) {
172		    case LEAF_begemotBridgeDefaultBridgeIf:
173			return (string_get(val, bridge_get_default_name(), -1));
174
175		    case LEAF_begemotBridgeDataUpdate:
176			val->v.integer = bridge_data_maxage;
177			return (SNMP_ERR_NOERROR);
178
179		    case LEAF_begemotBridgeDataPoll:
180			val->v.integer = bridge_poll_ticks / 100;
181			return (SNMP_ERR_NOERROR);
182		}
183		abort();
184
185	    case SNMP_OP_GETNEXT:
186		abort();
187
188	    case SNMP_OP_SET:
189		switch (val->var.subs[sub - 1]) {
190		    case LEAF_begemotBridgeDefaultBridgeIf:
191			/*
192			 * Cannot use string_save() here - requires either
193			 * a fixed-sized or var-length string - not less
194			 * than or equal.
195			 */
196			if (bridge_default_name_save(ctx,
197			    bridge_get_default_name()) < 0)
198				return (SNMP_ERR_RES_UNAVAIL);
199
200			if (bridge_set_default_name(val->v.octetstring.octets,
201			    val->v.octetstring.len) < 0)
202				return (SNMP_ERR_BADVALUE);
203			return (SNMP_ERR_NOERROR);
204
205		    case LEAF_begemotBridgeDataUpdate:
206			if (val->v.integer < SNMP_BRIDGE_DATA_MAXAGE_MIN ||
207			    val->v.integer > SNMP_BRIDGE_DATA_MAXAGE_MAX)
208				return (SNMP_ERR_WRONG_VALUE);
209			ctx->scratch->int1 = bridge_data_maxage;
210			bridge_data_maxage = val->v.integer;
211			return (SNMP_ERR_NOERROR);
212
213		    case LEAF_begemotBridgeDataPoll:
214			if (val->v.integer < SNMP_BRIDGE_POLL_INTERVAL_MIN ||
215			    val->v.integer > SNMP_BRIDGE_POLL_INTERVAL_MAX)
216				return (SNMP_ERR_WRONG_VALUE);
217			ctx->scratch->int1 = val->v.integer;
218			return (SNMP_ERR_NOERROR);
219		}
220		abort();
221
222	    case SNMP_OP_ROLLBACK:
223		switch (val->var.subs[sub - 1]) {
224		    case LEAF_begemotBridgeDefaultBridgeIf:
225			bridge_set_default_name(ctx->scratch->ptr1,
226			    ctx->scratch->int1);
227			free(ctx->scratch->ptr1);
228			break;
229		    case LEAF_begemotBridgeDataUpdate:
230			bridge_data_maxage = ctx->scratch->int1;
231			break;
232		}
233		return (SNMP_ERR_NOERROR);
234
235	    case SNMP_OP_COMMIT:
236		switch (val->var.subs[sub - 1]) {
237		    case LEAF_begemotBridgeDefaultBridgeIf:
238			free(ctx->scratch->ptr1);
239			break;
240		    case LEAF_begemotBridgeDataPoll:
241			bridge_set_poll_ticks(ctx->scratch->int1 * 100);
242			break;
243		}
244		return (SNMP_ERR_NOERROR);
245	}
246
247	abort();
248}
249
250/*
251 * Bridge mib module initialization hook.
252 * Returns 0 on success, < 0 on error.
253 */
254static int
255bridge_init(struct lmodule * mod, int argc __unused, char *argv[] __unused)
256{
257	bridge_module = mod;
258
259	if (bridge_kmod_load() < 0)
260		return (-1);
261
262	if (bridge_ioctl_init() < 0)
263		return (-1);
264
265	/* Register to get creation messages for bridge interfaces. */
266	if (mib_register_newif(bridge_attach_newif, bridge_module)) {
267		syslog(LOG_ERR, "Cannot register newif function: %s",
268		    strerror(errno));
269		return (-1);
270	}
271
272	return (0);
273}
274
275/*
276 * Bridge mib module finalization hook.
277 */
278static int
279bridge_fini(void)
280{
281	mib_unregister_newif(bridge_module);
282	or_unregister(reg_bridge);
283
284	if (bridge_data_timer != NULL) {
285		timer_stop(bridge_data_timer);
286		bridge_data_timer = NULL;
287	}
288
289	if (bridge_tc_timer != NULL) {
290		timer_stop(bridge_tc_timer);
291		bridge_tc_timer = NULL;
292	}
293
294	bridge_ifs_fini();
295	bridge_ports_fini();
296	bridge_addrs_fini();
297
298	return (0);
299}
300
301/*
302 * Bridge mib module start operation.
303 */
304static void
305bridge_start(void)
306{
307	reg_bridge = or_register(&oid_dot1Bridge,
308	    "The IETF MIB for Bridges (RFC 4188).", bridge_module);
309
310	bridge_data_timer = timer_start_repeat(bridge_poll_ticks,
311	    bridge_poll_ticks, bridge_update_all, NULL, bridge_module);
312
313	bridge_tc_timer = timer_start_repeat(bridge_tc_poll_ticks,
314	    bridge_tc_poll_ticks, bridge_update_tc_time, NULL, bridge_module);
315}
316
317static void
318bridge_dump(void)
319{
320	struct bridge_if *bif;
321
322	if ((bif = bridge_get_default()) == NULL)
323		syslog(LOG_ERR, "Dump: no default bridge interface");
324	else
325		syslog(LOG_ERR, "Dump: default bridge interface %s",
326		     bif->bif_name);
327
328	bridge_ifs_dump();
329	bridge_pf_dump();
330}
331
332const struct snmp_module config = {
333	.comment = "This module implements the bridge mib (RFC 4188).",
334	.init =		bridge_init,
335	.fini =		bridge_fini,
336	.start =	bridge_start,
337	.tree =		bridge_ctree,
338	.dump =		bridge_dump,
339	.tree_size =	bridge_CTREE_SIZE,
340};
341