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
50static struct lmodule *module;
51
52static const struct asn_oid oid_lm75 = OIDX_begemotLm75;
53
54/* the Object Resource registration index */
55static u_int lm75_index = 0;
56
57/* Number of available sensors in the system. */
58static int lm75_sensors;
59
60/*
61 * Structure that describes single sensor.
62 */
63struct 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
74static TAILQ_HEAD(, lm75_snmp_sensor) sensors =
75    TAILQ_HEAD_INITIALIZER(sensors);
76
77/* Ticks of the last sensors reading. */
78static uint64_t last_sensors_update;
79
80static void free_sensors(void);
81static int lm75_fini(void);
82static int lm75_init(struct lmodule *mod, int argc, char *argv[]);
83static void lm75_start(void);
84static int update_sensors(void);
85
86const 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
96static int
97lm75_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
107static void
108lm75_start(void)
109{
110
111	lm75_index = or_register(&oid_lm75,
112	    "The MIB module for reading lm75 sensors data.", module);
113}
114
115static int
116lm75_fini(void)
117{
118
119	or_unregister(lm75_index);
120	free_sensors();
121	closelog();
122
123	return (0);
124}
125
126static void
127free_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
137static int
138sysctlname(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
155static int
156sysctlgetnext(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
173static int
174update_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
196static void
197update_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
214static int
215add_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
246static int
247update_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		/* Alocate 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
333int
334op_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
367int
368op_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