1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 
31 #include <sys/param.h>
32 #include <sys/queue.h>
33 #include <sys/socket.h>
34 #include <sys/types.h>
35 
36 #include <net/ethernet.h>
37 #include <net/if.h>
38 #include <net/if_mib.h>
39 #include <net/if_types.h>
40 
41 #include <errno.h>
42 #include <stdarg.h>
43 #include <stdlib.h>
44 #include <stdio.h>
45 #include <string.h>
46 #include <syslog.h>
47 
48 #include <bsnmp/snmpmod.h>
49 #include <bsnmp/snmp_mibII.h>
50 
51 #define	SNMPTREE_TYPES
52 #include "bridge_tree.h"
53 #include "bridge_snmp.h"
54 #include "bridge_oid.h"
55 
56 static struct lmodule *bridge_module;
57 
58 /* For the registration. */
59 static const struct asn_oid oid_dot1Bridge = OIDX_dot1dBridge;
60 /* The registration. */
61 static uint reg_bridge;
62 
63 /* Periodic timer for polling all bridges' data. */
64 static void *bridge_data_timer;
65 static void *bridge_tc_timer;
66 
67 static int bridge_data_maxage = SNMP_BRIDGE_DATA_MAXAGE;
68 static int bridge_poll_ticks = SNMP_BRIDGE_POLL_INTERVAL * 100;
69 static int bridge_tc_poll_ticks = SNMP_BRIDGE_TC_POLL_INTERVAL * 100;
70 
71 /*
72  * Our default bridge, whose info will be visible under
73  * the dot1dBridge subtree and functions to set/fetch it.
74  */
75 static char bif_default_name[IFNAMSIZ] = "bridge0";
76 static struct bridge_if *bif_default;
77 
78 struct bridge_if *
79 bridge_get_default(void)
80 {
81 	struct mibif *ifp;
82 
83 	if (bif_default != NULL) {
84 
85 		/* Walk through the mibII interface list. */
86 		for (ifp = mib_first_if(); ifp != NULL; ifp = mib_next_if(ifp))
87 			if (strcmp(ifp->name, bif_default->bif_name) == 0)
88 				break;
89 
90 		if (ifp == NULL)
91 			bif_default = NULL;
92 	}
93 
94 	return (bif_default);
95 }
96 
97 void
98 bridge_set_default(struct bridge_if *bif)
99 {
100 	bif_default = bif;
101 
102 	syslog(LOG_ERR, "Set default bridge interface to: %s",
103 	    bif == NULL ? "(none)" : bif->bif_name);
104 }
105 
106 const char *
107 bridge_get_default_name(void)
108 {
109 	return (bif_default_name);
110 }
111 
112 static int
113 bridge_set_default_name(const char *bif_name, uint len)
114 {
115 	struct bridge_if *bif;
116 
117 	if (len >= IFNAMSIZ)
118 		return (-1);
119 
120 	bcopy(bif_name, bif_default_name, len);
121 	bif_default_name[len] = '\0';
122 
123 	if ((bif = bridge_if_find_ifname(bif_default_name)) == NULL) {
124 		bif_default = NULL;
125 		return (0);
126 	}
127 
128 	bif_default = bif;
129 	return (1);
130 }
131 
132 int
133 bridge_get_data_maxage(void)
134 {
135 	return (bridge_data_maxage);
136 }
137 
138 static void
139 bridge_set_poll_ticks(int poll_ticks)
140 {
141 	if (bridge_data_timer != NULL)
142 		timer_stop(bridge_data_timer);
143 
144 	bridge_poll_ticks = poll_ticks;
145 	bridge_data_timer = timer_start_repeat(bridge_poll_ticks,
146 	    bridge_poll_ticks, bridge_update_all, NULL, bridge_module);
147 }
148 /*
149  * The bridge module configuration via SNMP.
150  */
151 static int
152 bridge_default_name_save(struct snmp_context *ctx, const char *bridge_default)
153 {
154 	if ((ctx->scratch->int1 = strlen(bridge_default)) >= IFNAMSIZ)
155 		return (-1);
156 
157 	if ((ctx->scratch->ptr1 = malloc(IFNAMSIZ)) == NULL)
158 		return (-1);
159 
160 	strncpy(ctx->scratch->ptr1, bridge_default, ctx->scratch->int1);
161 	return (0);
162 }
163 
164 int
165 op_begemot_bridge_config(struct snmp_context *ctx, struct snmp_value *val,
166     uint sub, uint iidx __unused, enum snmp_op op)
167 {
168 	switch (op) {
169 	    case SNMP_OP_GET:
170 		switch (val->var.subs[sub - 1]) {
171 		    case LEAF_begemotBridgeDefaultBridgeIf:
172 			return (string_get(val, bridge_get_default_name(), -1));
173 
174 		    case LEAF_begemotBridgeDataUpdate:
175 			val->v.integer = bridge_data_maxage;
176 			return (SNMP_ERR_NOERROR);
177 
178 		    case LEAF_begemotBridgeDataPoll:
179 			val->v.integer = bridge_poll_ticks / 100;
180 			return (SNMP_ERR_NOERROR);
181 		}
182 		abort();
183 
184 	    case SNMP_OP_GETNEXT:
185 		abort();
186 
187 	    case SNMP_OP_SET:
188 		switch (val->var.subs[sub - 1]) {
189 		    case LEAF_begemotBridgeDefaultBridgeIf:
190 			/*
191 			 * Cannot use string_save() here - requires either
192 			 * a fixed-sized or var-length string - not less
193 			 * than or equal.
194 			 */
195 			if (bridge_default_name_save(ctx,
196 			    bridge_get_default_name()) < 0)
197 				return (SNMP_ERR_RES_UNAVAIL);
198 
199 			if (bridge_set_default_name(val->v.octetstring.octets,
200 			    val->v.octetstring.len) < 0)
201 				return (SNMP_ERR_BADVALUE);
202 			return (SNMP_ERR_NOERROR);
203 
204 		    case LEAF_begemotBridgeDataUpdate:
205 			if (val->v.integer < SNMP_BRIDGE_DATA_MAXAGE_MIN ||
206 			    val->v.integer > SNMP_BRIDGE_DATA_MAXAGE_MAX)
207 				return (SNMP_ERR_WRONG_VALUE);
208 			ctx->scratch->int1 = bridge_data_maxage;
209 			bridge_data_maxage = val->v.integer;
210 			return (SNMP_ERR_NOERROR);
211 
212 		    case LEAF_begemotBridgeDataPoll:
213 			if (val->v.integer < SNMP_BRIDGE_POLL_INTERVAL_MIN ||
214 			    val->v.integer > SNMP_BRIDGE_POLL_INTERVAL_MAX)
215 				return (SNMP_ERR_WRONG_VALUE);
216 			ctx->scratch->int1 = val->v.integer;
217 			return (SNMP_ERR_NOERROR);
218 		}
219 		abort();
220 
221 	    case SNMP_OP_ROLLBACK:
222 		switch (val->var.subs[sub - 1]) {
223 		    case LEAF_begemotBridgeDefaultBridgeIf:
224 			bridge_set_default_name(ctx->scratch->ptr1,
225 			    ctx->scratch->int1);
226 			free(ctx->scratch->ptr1);
227 			break;
228 		    case LEAF_begemotBridgeDataUpdate:
229 			bridge_data_maxage = ctx->scratch->int1;
230 			break;
231 		}
232 		return (SNMP_ERR_NOERROR);
233 
234 	    case SNMP_OP_COMMIT:
235 		switch (val->var.subs[sub - 1]) {
236 		    case LEAF_begemotBridgeDefaultBridgeIf:
237 			free(ctx->scratch->ptr1);
238 			break;
239 		    case LEAF_begemotBridgeDataPoll:
240 			bridge_set_poll_ticks(ctx->scratch->int1 * 100);
241 			break;
242 		}
243 		return (SNMP_ERR_NOERROR);
244 	}
245 
246 	abort();
247 }
248 
249 /*
250  * Bridge mib module initialization hook.
251  * Returns 0 on success, < 0 on error.
252  */
253 static int
254 bridge_init(struct lmodule * mod, int argc __unused, char *argv[] __unused)
255 {
256 	bridge_module = mod;
257 
258 	if (bridge_kmod_load() < 0)
259 		return (-1);
260 
261 	if (bridge_ioctl_init() < 0)
262 		return (-1);
263 
264 	/* Register to get creation messages for bridge interfaces. */
265 	if (mib_register_newif(bridge_attach_newif, bridge_module)) {
266 		syslog(LOG_ERR, "Cannot register newif function: %s",
267 		    strerror(errno));
268 		return (-1);
269 	}
270 
271 	return (0);
272 }
273 
274 /*
275  * Bridge mib module finalization hook.
276  */
277 static int
278 bridge_fini(void)
279 {
280 	mib_unregister_newif(bridge_module);
281 	or_unregister(reg_bridge);
282 
283 	if (bridge_data_timer != NULL) {
284 		timer_stop(bridge_data_timer);
285 		bridge_data_timer = NULL;
286 	}
287 
288 	if (bridge_tc_timer != NULL) {
289 		timer_stop(bridge_tc_timer);
290 		bridge_tc_timer = NULL;
291 	}
292 
293 	bridge_ifs_fini();
294 	bridge_ports_fini();
295 	bridge_addrs_fini();
296 
297 	return (0);
298 }
299 
300 /*
301  * Bridge mib module start operation.
302  */
303 static void
304 bridge_start(void)
305 {
306 	reg_bridge = or_register(&oid_dot1Bridge,
307 	    "The IETF MIB for Bridges (RFC 4188).", bridge_module);
308 
309 	bridge_data_timer = timer_start_repeat(bridge_poll_ticks,
310 	    bridge_poll_ticks, bridge_update_all, NULL, bridge_module);
311 
312 	bridge_tc_timer = timer_start_repeat(bridge_tc_poll_ticks,
313 	    bridge_tc_poll_ticks, bridge_update_tc_time, NULL, bridge_module);
314 }
315 
316 static void
317 bridge_dump(void)
318 {
319 	struct bridge_if *bif;
320 
321 	if ((bif = bridge_get_default()) == NULL)
322 		syslog(LOG_ERR, "Dump: no default bridge interface");
323 	else
324 		syslog(LOG_ERR, "Dump: default bridge interface %s",
325 		     bif->bif_name);
326 
327 	bridge_ifs_dump();
328 	bridge_pf_dump();
329 }
330 
331 const struct snmp_module config = {
332 	.comment = "This module implements the bridge mib (RFC 4188).",
333 	.init =		bridge_init,
334 	.fini =		bridge_fini,
335 	.start =	bridge_start,
336 	.tree =		bridge_ctree,
337 	.dump =		bridge_dump,
338 	.tree_size =	bridge_CTREE_SIZE,
339 };
340