3142bf3dd84e81cb262e35d3168aa7a8d2acde71
1 /**
2 * collectd - src/mqtt.c
3 * Copyright (C) 2014 Marc Falzon <marc at baha dot mu>
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 **/
24 // Reference: http://mosquitto.org/api/files/mosquitto-h.html
27 #include "collectd.h"
28 #include "common.h"
29 #include "plugin.h"
30 #include "utils_cache.h"
31 #include "utils_complain.h"
33 #include <pthread.h>
35 #include <mosquitto.h>
37 #define MQTT_MAX_TOPIC_SIZE 1024
38 #define MQTT_MAX_MESSAGE_SIZE MQTT_MAX_TOPIC_SIZE + 1024
39 #define MQTT_DEFAULT_HOST "localhost"
40 #define MQTT_DEFAULT_PORT 1883
41 #define MQTT_DEFAULT_TOPIC_PREFIX "collectd"
43 /*
44 * Data types
45 */
46 struct mqtt_client_conf
47 {
48 char *name;
50 struct mosquitto *mosq;
51 _Bool connected;
53 char *host;
54 int port;
55 char *username;
56 char *password;
58 char *client_id;
59 char *topic_prefix;
60 _Bool store_rates;
61 _Bool retain;
62 int qos;
64 c_complain_t complaint_cantpublish;
65 pthread_mutex_t lock;
66 };
67 typedef struct mqtt_client_conf mqtt_client_conf_t;
69 static char const *mosquitto_strerror (int code)
70 {
71 switch (code)
72 {
73 case MOSQ_ERR_SUCCESS: return "MOSQ_ERR_SUCCESS";
74 case MOSQ_ERR_NOMEM: return "MOSQ_ERR_NOMEM";
75 case MOSQ_ERR_PROTOCOL: return "MOSQ_ERR_PROTOCOL";
76 case MOSQ_ERR_INVAL: return "MOSQ_ERR_INVAL";
77 case MOSQ_ERR_NO_CONN: return "MOSQ_ERR_NO_CONN";
78 case MOSQ_ERR_CONN_REFUSED: return "MOSQ_ERR_CONN_REFUSED";
79 case MOSQ_ERR_NOT_FOUND: return "MOSQ_ERR_NOT_FOUND";
80 case MOSQ_ERR_CONN_LOST: return "MOSQ_ERR_CONN_LOST";
81 case MOSQ_ERR_SSL: return "MOSQ_ERR_SSL";
82 case MOSQ_ERR_PAYLOAD_SIZE: return "MOSQ_ERR_PAYLOAD_SIZE";
83 case MOSQ_ERR_NOT_SUPPORTED: return "MOSQ_ERR_NOT_SUPPORTED";
84 case MOSQ_ERR_AUTH: return "MOSQ_ERR_AUTH";
85 case MOSQ_ERR_ACL_DENIED: return "MOSQ_ERR_ACL_DENIED";
86 case MOSQ_ERR_UNKNOWN: return "MOSQ_ERR_UNKNOWN";
87 case MOSQ_ERR_ERRNO: return "MOSQ_ERR_ERRNO";
88 }
90 return "UNKNOWN ERROR CODE";
91 }
93 static void mqtt_free (mqtt_client_conf_t *conf)
94 {
95 if (conf == NULL)
96 return;
98 if (conf->connected)
99 (void) mosquitto_disconnect (conf->mosq);
100 conf->connected = 0;
101 (void) mosquitto_destroy (conf->mosq);
103 sfree (conf->host);
104 sfree (conf->username);
105 sfree (conf->password);
106 sfree (conf->client_id);
107 sfree (conf->topic_prefix);
108 sfree (conf);
109 }
111 /*
112 * Functions
113 */
114 /* must hold conf->lock when calling. */
115 static int mqtt_reconnect (mqtt_client_conf_t *conf)
116 {
117 int status;
119 if (conf->connected)
120 return (0);
122 status = mosquitto_reconnect (conf->mosq);
123 if (status != MOSQ_ERR_SUCCESS)
124 {
125 char errbuf[1024];
126 ERROR ("mqtt_connect_broker: mosquitto_connect failed: %s",
127 (status == MOSQ_ERR_ERRNO)
128 ? sstrerror(errno, errbuf, sizeof (errbuf))
129 : mosquitto_strerror (status));
130 return (-1);
131 }
133 conf->connected = 1;
135 c_release (LOG_INFO,
136 &conf->complaint_cantpublish,
137 "mqtt plugin: successfully reconnected to broker \"%s:%d\"",
138 conf->host, conf->port);
140 return (0);
141 } /* mqtt_reconnect */
143 /* must hold conf->lock when calling. */
144 static int mqtt_connect (mqtt_client_conf_t *conf)
145 {
146 char const *client_id;
147 int status;
149 if (conf->mosq != NULL)
150 return mqtt_reconnect (conf);
152 if (conf->client_id)
153 client_id = conf->client_id;
154 else
155 client_id = hostname_g;
157 conf->mosq = mosquitto_new (client_id, /* user data = */ conf);
158 if (conf->mosq == NULL)
159 {
160 ERROR ("mqtt plugin: mosquitto_new failed");
161 return (-1);
162 }
164 if (conf->username && conf->password)
165 {
166 status = mosquitto_username_pw_set (conf->mosq, conf->username, conf->password);
167 if (status != MOSQ_ERR_SUCCESS)
168 {
169 char errbuf[1024];
170 ERROR ("mqtt plugin: mosquitto_username_pw_set failed: %s",
171 (status == MOSQ_ERR_ERRNO)
172 ? sstrerror (errno, errbuf, sizeof (errbuf))
173 : mosquitto_strerror (status));
175 mosquitto_destroy (conf->mosq);
176 conf->mosq = NULL;
177 return (-1);
178 }
179 }
181 status = mosquitto_connect (conf->mosq, conf->host, conf->port,
182 /* keepalive = */ 10, /* clean session = */ 1);
183 if (status != MOSQ_ERR_SUCCESS)
184 {
185 char errbuf[1024];
186 ERROR ("mqtt plugin: mosquitto_connect failed: %s",
187 (status == MOSQ_ERR_ERRNO)
188 ? sstrerror (errno, errbuf, sizeof (errbuf))
189 : mosquitto_strerror (status));
191 mosquitto_destroy (conf->mosq);
192 conf->mosq = NULL;
193 return (-1);
194 }
196 conf->connected = 1;
197 return (0);
198 } /* mqtt_connect */
200 static int publish (mqtt_client_conf_t *conf, char const *topic,
201 void const *payload, size_t payload_len)
202 {
203 int status;
205 pthread_mutex_lock (&conf->lock);
207 status = mqtt_connect (conf);
208 if (status != 0) {
209 pthread_mutex_unlock (&conf->lock);
210 ERROR ("mqtt plugin: unable to reconnect to broker");
211 return (status);
212 }
214 status = mosquitto_publish(conf->mosq,
215 /* message id */ NULL,
216 topic,
217 (uint32_t) payload_len, payload,
218 /* qos */ conf->qos,
219 /* retain */ conf->retain);
220 if (status != MOSQ_ERR_SUCCESS)
221 {
222 char errbuf[1024];
223 c_complain (LOG_ERR,
224 &conf->complaint_cantpublish,
225 "plugin mqtt: mosquitto_publish failed: %s",
226 status == MOSQ_ERR_ERRNO ?
227 sstrerror(errno, errbuf, sizeof (errbuf)) :
228 mosquitto_strerror(status));
229 /* Mark our connection "down" regardless of the error as a safety
230 * measure; we will try to reconnect the next time we have to publish a
231 * message */
232 conf->connected = 0;
234 pthread_mutex_unlock (&conf->lock);
235 return (-1);
236 }
238 pthread_mutex_unlock (&conf->lock);
239 return (0);
240 } /* int publish */
242 static int format_topic (char *buf, size_t buf_len,
243 data_set_t const *ds, value_list_t const *vl,
244 mqtt_client_conf_t *conf)
245 {
246 char name[MQTT_MAX_TOPIC_SIZE];
247 int status;
249 if ((conf->topic_prefix == NULL) || (conf->topic_prefix[0] == 0))
250 return (FORMAT_VL (buf, buf_len, vl));
252 status = FORMAT_VL (name, sizeof (name), vl);
253 if (status != 0)
254 return (status);
256 status = ssnprintf (buf, buf_len, "%s/%s", conf->topic_prefix, name);
257 if ((status < 0) || (((size_t) status) >= buf_len))
258 return (ENOMEM);
260 return (0);
261 } /* int format_topic */
263 static int mqtt_write (const data_set_t *ds, const value_list_t *vl,
264 user_data_t *user_data)
265 {
266 mqtt_client_conf_t *conf;
267 char topic[MQTT_MAX_TOPIC_SIZE];
268 char payload[MQTT_MAX_MESSAGE_SIZE];
269 int status = 0;
271 if ((user_data == NULL) || (user_data->data == NULL))
272 return (EINVAL);
273 conf = user_data->data;
275 status = format_topic (topic, sizeof (topic), ds, vl, conf);
276 if (status != 0)
277 {
278 ERROR ("mqtt plugin: format_topic failed with status %d.", status);
279 return (status);
280 }
282 status = format_values (payload, sizeof (payload),
283 ds, vl, conf->store_rates);
284 if (status != 0)
285 {
286 ERROR ("mqtt plugin: format_values failed with status %d.", status);
287 return (status);
288 }
290 status = publish (conf, topic, payload, sizeof (payload));
291 if (status != 0)
292 {
293 ERROR ("mqtt plugin: publish failed: %s", mosquitto_strerror (status));
294 return (status);
295 }
297 return (status);
298 } /* mqtt_write */
300 /*
301 * <Publish "name">
302 * Host "example.com"
303 * Port 1883
304 * Prefix "collectd"
305 * ClientId "collectd"
306 * User "guest"
307 * Password "secret"
308 * StoreRates true
309 * Retain false
310 * QoS 0
311 * </Publish>
312 */
313 static int mqtt_config_broker (oconfig_item_t *ci)
314 {
315 mqtt_client_conf_t *conf;
316 user_data_t user_data;
317 int status;
318 int i;
320 conf = calloc (1, sizeof (*conf));
321 if (conf == NULL)
322 {
323 ERROR ("mqtt plugin: malloc failed.");
324 return (-1);
325 }
327 conf->name = NULL;
328 status = cf_util_get_string (ci, &conf->name);
329 if (status != 0)
330 {
331 mqtt_free (conf);
332 return (status);
333 }
335 conf->host = strdup (MQTT_DEFAULT_HOST);
336 conf->port = MQTT_DEFAULT_PORT;
337 conf->client_id = NULL;
338 conf->topic_prefix = strdup (MQTT_DEFAULT_TOPIC_PREFIX);
339 C_COMPLAIN_INIT (&conf->complaint_cantpublish);
341 for (i = 0; i < ci->children_num; i++)
342 {
343 oconfig_item_t *child = ci->children + i;
344 if (strcasecmp ("Host", child->key) == 0)
345 cf_util_get_string (child, &conf->host);
346 else if (strcasecmp ("Port", child->key) == 0)
347 {
348 int tmp = cf_util_get_port_number (child);
349 if (tmp < 0)
350 ERROR ("mqtt plugin: Invalid port number.");
351 else
352 conf->port = tmp;
353 }
354 else if (strcasecmp ("Prefix", child->key) == 0)
355 cf_util_get_string (child, &conf->topic_prefix);
356 else if (strcasecmp ("ClientId", child->key) == 0)
357 cf_util_get_string (child, &conf->client_id);
358 else if (strcasecmp ("User", child->key) == 0)
359 cf_util_get_string (child, &conf->username);
360 else if (strcasecmp ("Password", child->key) == 0)
361 cf_util_get_string (child, &conf->password);
362 else if (strcasecmp ("StoreRates", child->key) == 0)
363 cf_util_get_boolean (child, &conf->store_rates);
364 else if (strcasecmp ("Retain", child->key) == 0)
365 cf_util_get_boolean (child, &conf->retain);
366 else if (strcasecmp ("QoS", child->key) == 0)
367 {
368 int tmp = -1;
369 status = cf_util_get_int (child, &tmp);
370 if ((status != 0) || (tmp < 0) || (tmp > 2))
371 ERROR ("mqtt plugin: Not a valid QoS setting.");
372 else
373 conf->qos = tmp;
374 }
375 else
376 ERROR ("mqtt plugin: Unknown config option: %s", child->key);
377 }
379 memset (&user_data, 0, sizeof (user_data));
380 user_data.data = conf;
382 DEBUG ("mqtt plugin: successfully connected to broker \"%s:%d\"",
383 conf->host, conf->port);
385 plugin_register_write ("mqtt", mqtt_write, &user_data);
386 return (0);
387 } /* mqtt_config_broker */
389 /*
390 * <Plugin mqtt>
391 * <Publish "name">
392 * # ...
393 * </Publish>
394 * </Plugin>
395 */
396 static int mqtt_config (oconfig_item_t *ci)
397 {
398 int i;
400 for (i = 0; i < ci->children_num; i++)
401 {
402 oconfig_item_t *child = ci->children + i;
404 if (strcasecmp ("Publish", child->key) == 0)
405 mqtt_config_broker (child);
406 else
407 ERROR ("mqtt plugin: Unknown config option: %s", child->key);
408 }
410 return (0);
411 } /* int mqtt_config */
413 static int mqtt_init (void)
414 {
415 mosquitto_lib_init();
417 return (0);
418 } /* mqtt_init */
420 void module_register (void)
421 {
422 plugin_register_complex_config ("mqtt", mqtt_config);
423 plugin_register_init ("mqtt", mqtt_init);
424 } /* void module_register */
426 /* vim: set sw=4 sts=4 et fdm=marker : */