xref: /freebsd/usr.sbin/bsnmpd/modules/snmp_bridge/bridge_snmp.c (revision 4928135658a9d0eaee37003df6137ab363fcb0b4)
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  * $FreeBSD$
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 
57 static struct lmodule *bridge_module;
58 
59 /* For the registration. */
60 static const struct asn_oid oid_dot1Bridge = OIDX_dot1dBridge;
61 /* The registration. */
62 static uint reg_bridge;
63 
64 /* Periodic timer for polling all bridges' data. */
65 static void *bridge_data_timer;
66 static void *bridge_tc_timer;
67 
68 static int bridge_data_maxage = SNMP_BRIDGE_DATA_MAXAGE;
69 static int bridge_poll_ticks = SNMP_BRIDGE_POLL_INTERVAL * 100;
70 static 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  */
76 static char bif_default_name[IFNAMSIZ] = "bridge0";
77 static struct bridge_if *bif_default;
78 
79 struct bridge_if *
80 bridge_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 
98 void
99 bridge_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 
107 const char *
108 bridge_get_default_name(void)
109 {
110 	return (bif_default_name);
111 }
112 
113 static int
114 bridge_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 
133 int
134 bridge_get_data_maxage(void)
135 {
136 	return (bridge_data_maxage);
137 }
138 
139 static void
140 bridge_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  */
152 static int
153 bridge_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 
165 int
166 op_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  */
254 static int
255 bridge_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  */
278 static int
279 bridge_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  */
304 static void
305 bridge_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 
317 static void
318 bridge_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 
332 const 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