xref: /freebsd/usr.sbin/bsnmpd/modules/snmp_lm75/snmp_lm75.c (revision 9f23cbd6cae82fd77edfad7173432fa8dccd0a95)
1 /*-
2  * Copyright (c) 2014 Luiz Otavio O Souza <loos@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/queue.h>
32 #include <sys/sysctl.h>
33 
34 #include <bsnmp/snmpmod.h>
35 
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <syslog.h>
40 
41 #include "lm75_oid.h"
42 #include "lm75_tree.h"
43 
44 #ifndef	LM75BUF
45 #define	LM75BUF		64
46 #endif
47 #define	TZ_ZEROC	2732
48 #define	UPDATE_INTERVAL	500	/* update interval in ticks */
49 
50 static struct lmodule *module;
51 
52 static const struct asn_oid oid_lm75 = OIDX_begemotLm75;
53 
54 /* the Object Resource registration index */
55 static u_int lm75_index = 0;
56 
57 /* Number of available sensors in the system. */
58 static int lm75_sensors;
59 
60 /*
61  * Structure that describes single sensor.
62  */
63 struct lm75_snmp_sensor {
64 	TAILQ_ENTRY(lm75_snmp_sensor) link;
65 	int32_t		index;
66 	int32_t		sysctlidx;
67 	int32_t		temp;
68 	char		desc[LM75BUF];
69 	char		location[LM75BUF];
70 	char		parent[LM75BUF];
71 	char		pnpinfo[LM75BUF];
72 };
73 
74 static TAILQ_HEAD(, lm75_snmp_sensor) sensors =
75     TAILQ_HEAD_INITIALIZER(sensors);
76 
77 /* Ticks of the last sensors reading. */
78 static uint64_t last_sensors_update;
79 
80 static void free_sensors(void);
81 static int lm75_fini(void);
82 static int lm75_init(struct lmodule *mod, int argc, char *argv[]);
83 static void lm75_start(void);
84 static int update_sensors(void);
85 
86 const struct snmp_module config = {
87     .comment   =
88 	"This module implements the BEGEMOT MIB for reading LM75 sensors data.",
89     .init      = lm75_init,
90     .start     = lm75_start,
91     .fini      = lm75_fini,
92     .tree      = lm75_ctree,
93     .tree_size = lm75_CTREE_SIZE,
94 };
95 
96 static int
97 lm75_init(struct lmodule *mod, int argc __unused, char *argv[] __unused)
98 {
99 
100 	module = mod;
101 
102 	lm75_sensors = 0;
103 
104 	return(0);
105 }
106 
107 static void
108 lm75_start(void)
109 {
110 
111 	lm75_index = or_register(&oid_lm75,
112 	    "The MIB module for reading lm75 sensors data.", module);
113 }
114 
115 static int
116 lm75_fini(void)
117 {
118 
119 	or_unregister(lm75_index);
120 	free_sensors();
121 	closelog();
122 
123 	return (0);
124 }
125 
126 static void
127 free_sensors(void)
128 {
129 	struct lm75_snmp_sensor *sensor;
130 
131 	while ((sensor = TAILQ_FIRST(&sensors)) != NULL) {
132 		TAILQ_REMOVE(&sensors, sensor, link);
133 		free(sensor);
134 	}
135 }
136 
137 static int
138 sysctlname(int *oid, int nlen, char *name, size_t len)
139 {
140 	int mib[12];
141 
142 	if (nlen > (int)(sizeof(mib) / sizeof(int) - 2))
143 		return (-1);
144 
145 	mib[0] = 0;
146 	mib[1] = 1;
147 	memcpy(mib + 2, oid, nlen * sizeof(int));
148 
149 	if (sysctl(mib, nlen + 2, name, &len, 0, 0) == -1)
150 		return (-1);
151 
152 	return (0);
153 }
154 
155 static int
156 sysctlgetnext(int *oid, int nlen, int *next, size_t *nextlen)
157 {
158 	int mib[12];
159 
160 	if (nlen > (int)(sizeof(mib) / sizeof(int) - 2))
161 		return (-1);
162 
163 	mib[0] = 0;
164 	mib[1] = 2;
165 	memcpy(mib + 2, oid, nlen * sizeof(int));
166 
167 	if (sysctl(mib, nlen + 2, next, nextlen, 0, 0) == -1)
168 		return (-1);
169 
170 	return (0);
171 }
172 
173 static int
174 update_sensor_sysctl(void *obuf, size_t *obuflen, int idx, const char *name)
175 {
176 	char buf[LM75BUF];
177 	int mib[5];
178 	size_t len;
179 
180 	/* Fill out the mib information. */
181 	snprintf(buf, sizeof(buf) - 1, "dev.lm75.%d.%s", idx, name);
182 	len = sizeof(mib) / sizeof(int);
183 	if (sysctlnametomib(buf, mib, &len) == -1)
184 		return (-1);
185 
186 	if (len != 4)
187 		return (-1);
188 
189 	/* Read the sysctl data. */
190 	if (sysctl(mib, len, obuf, obuflen, NULL, 0) == -1)
191 		return (-1);
192 
193 	return (0);
194 }
195 
196 static void
197 update_sensor(struct lm75_snmp_sensor *sensor, int idx)
198 {
199 	size_t len;
200 
201 	len = sizeof(sensor->desc);
202 	update_sensor_sysctl(sensor->desc, &len, idx, "%desc");
203 
204 	len = sizeof(sensor->location);
205 	update_sensor_sysctl(sensor->location, &len, idx, "%location");
206 
207 	len = sizeof(sensor->pnpinfo);
208 	update_sensor_sysctl(sensor->pnpinfo, &len, idx, "%pnpinfo");
209 
210 	len = sizeof(sensor->parent);
211 	update_sensor_sysctl(sensor->parent, &len, idx, "%parent");
212 }
213 
214 static int
215 add_sensor(char *buf)
216 {
217 	int idx, temp;
218 	size_t len;
219 	struct lm75_snmp_sensor *sensor;
220 
221 	if (sscanf(buf, "dev.lm75.%d.temperature", &idx) != 1)
222 		return (-1);
223 
224 	/* Read the sensor temperature. */
225 	len = sizeof(temp);
226 	if (update_sensor_sysctl(&temp, &len, idx, "temperature") != 0)
227 		return (-1);
228 
229 	/* Add the sensor data to the table. */
230 	sensor = calloc(1, sizeof(*sensor));
231 	if (sensor == NULL) {
232 		syslog(LOG_ERR, "Unable to allocate %zu bytes for resource",
233 		    sizeof(*sensor));
234 		return (-1);
235 	}
236 	sensor->index = ++lm75_sensors;
237 	sensor->sysctlidx = idx;
238 	sensor->temp = (temp - TZ_ZEROC) / 10;
239 	TAILQ_INSERT_TAIL(&sensors, sensor, link);
240 
241 	update_sensor(sensor, idx);
242 
243 	return (0);
244 }
245 
246 static int
247 update_sensors(void)
248 {
249 	char buf[LM75BUF];
250 	int i, root[5], *next, *oid;
251 	size_t len, nextlen, rootlen;
252 	static uint64_t now;
253 
254 	now = get_ticks();
255 	if (now - last_sensors_update < UPDATE_INTERVAL)
256 		return (0);
257 
258 	last_sensors_update = now;
259 
260 	/* Reset the sensor data. */
261 	free_sensors();
262 	lm75_sensors = 0;
263 
264 	/* Start from the lm75 default root node. */
265 	rootlen = 2;
266 	if (sysctlnametomib("dev.lm75", root, &rootlen) == -1)
267 		return (0);
268 
269 	oid = (int *)malloc(sizeof(int) * rootlen);
270 	if (oid == NULL) {
271 		perror("malloc");
272 		return (-1);
273 	}
274 	memcpy(oid, root, rootlen * sizeof(int));
275 	len = rootlen;
276 
277 	/* Traverse the sysctl(3) interface and find the active sensors. */
278 	for (;;) {
279 
280 		/* Find the size of the next mib. */
281 		nextlen = 0;
282 		if (sysctlgetnext(oid, len, NULL, &nextlen) == -1) {
283 			free(oid);
284 			return (0);
285 		}
286 		/* Allocate and read the next mib. */
287 		next = (int *)malloc(nextlen);
288 		if (next == NULL) {
289 			syslog(LOG_ERR,
290 			    "Unable to allocate %zu bytes for resource",
291 			    nextlen);
292 			free(oid);
293 			return (-1);
294 		}
295 		if (sysctlgetnext(oid, len, next, &nextlen) == -1) {
296 			free(oid);
297 			free(next);
298 			return (0);
299 		}
300 		free(oid);
301 		/* Check if we care about the next mib. */
302 		for (i = 0; i < (int)rootlen; i++)
303 			if (next[i] != root[i]) {
304 				free(next);
305 				return (0);
306 			}
307 		oid = (int *)malloc(nextlen);
308 		if (oid == NULL) {
309 			syslog(LOG_ERR,
310 			    "Unable to allocate %zu bytes for resource",
311 			    nextlen);
312 			free(next);
313 			return (-1);
314 		}
315 		memcpy(oid, next, nextlen);
316 		free(next);
317 		len = nextlen / sizeof(int);
318 
319 		/* Find the mib name. */
320 		if (sysctlname(oid, len, buf, sizeof(buf)) != 0)
321 			continue;
322 
323 		if (strstr(buf, "temperature"))
324 			if (add_sensor(buf) != 0) {
325 				free(oid);
326 				return (-1);
327 			}
328 	}
329 
330 	return (0);
331 }
332 
333 int
334 op_lm75Sensors(struct snmp_context *context __unused, struct snmp_value *value,
335     u_int sub, u_int iidx __unused, enum snmp_op op)
336 {
337 	asn_subid_t which;
338 
339 	if (update_sensors() == -1)
340 		return (SNMP_ERR_RES_UNAVAIL);
341 
342 	which = value->var.subs[sub - 1];
343 
344 	switch (op) {
345 	case SNMP_OP_GET:
346 		switch (which) {
347 		case LEAF_lm75Sensors:
348 			value->v.integer = lm75_sensors;
349 			break;
350 		default:
351 			return (SNMP_ERR_RES_UNAVAIL);
352 		}
353 		break;
354 	case SNMP_OP_SET:
355 		return (SNMP_ERR_NOT_WRITEABLE);
356 	case SNMP_OP_GETNEXT:
357 	case SNMP_OP_ROLLBACK:
358 	case SNMP_OP_COMMIT:
359 		return (SNMP_ERR_NOERROR);
360 	default:
361 		return (SNMP_ERR_RES_UNAVAIL);
362 	}
363 
364 	return (SNMP_ERR_NOERROR);
365 }
366 
367 int
368 op_lm75SensorTable(struct snmp_context *context __unused,
369     struct snmp_value *value, u_int sub, u_int iidx __unused, enum snmp_op op)
370 {
371 	struct lm75_snmp_sensor *sensor;
372 	asn_subid_t which;
373 	int ret;
374 
375 	if (update_sensors() == -1)
376 		return (SNMP_ERR_RES_UNAVAIL);
377 
378 	which = value->var.subs[sub - 1];
379 
380 	switch (op) {
381 	case SNMP_OP_GETNEXT:
382 		sensor = NEXT_OBJECT_INT(&sensors, &value->var, sub);
383 		if (sensor == NULL)
384 			return (SNMP_ERR_NOSUCHNAME);
385 		value->var.len = sub + 1;
386 		value->var.subs[sub] = sensor->index;
387 		break;
388 	case SNMP_OP_GET:
389 		if (value->var.len - sub != 1)
390 			return (SNMP_ERR_NOSUCHNAME);
391 		sensor = FIND_OBJECT_INT(&sensors, &value->var, sub);
392 		if (sensor == NULL)
393 			return (SNMP_ERR_NOSUCHNAME);
394 		break;
395 	case SNMP_OP_SET:
396 		return (SNMP_ERR_NOT_WRITEABLE);
397 	case SNMP_OP_ROLLBACK:
398 	case SNMP_OP_COMMIT:
399 		return (SNMP_ERR_NOERROR);
400 	default:
401 		return (SNMP_ERR_RES_UNAVAIL);
402 	}
403 
404 	ret = SNMP_ERR_NOERROR;
405 
406 	switch (which) {
407 	case LEAF_lm75SensorIndex:
408 		value->v.integer = sensor->index;
409 		break;
410 	case LEAF_lm75SensorSysctlIndex:
411 		value->v.integer = sensor->sysctlidx;
412 		break;
413 	case LEAF_lm75SensorDesc:
414 		ret = string_get(value, sensor->desc, -1);
415 		break;
416 	case LEAF_lm75SensorLocation:
417 		ret = string_get(value, sensor->location, -1);
418 		break;
419 	case LEAF_lm75SensorPnpInfo:
420 		ret = string_get(value, sensor->pnpinfo, -1);
421 		break;
422 	case LEAF_lm75SensorParent:
423 		ret = string_get(value, sensor->parent, -1);
424 		break;
425 	case LEAF_lm75SensorTemperature:
426 		value->v.integer = sensor->temp;
427 		break;
428 	default:
429 		ret = SNMP_ERR_RES_UNAVAIL;
430 		break;
431 	}
432 
433 	return (ret);
434 }
435