7f785dc86b8a89249141ea37a3866e45cd23978f
1 /**
2 * collectd - src/mqtt.c
3 * Copyright (C) 2014 Marc Falzon
4 * Copyright (C) 2014,2015 Florian octo Forster
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22 * DEALINGS IN THE SOFTWARE.
23 *
24 * Authors:
25 * Marc Falzon <marc at baha dot mu>
26 * Florian octo Forster <octo at collectd.org>
27 **/
29 // Reference: http://mosquitto.org/api/files/mosquitto-h.html
32 #include "collectd.h"
33 #include "common.h"
34 #include "plugin.h"
35 #include "utils_cache.h"
36 #include "utils_complain.h"
38 #include <pthread.h>
40 #include <mosquitto.h>
42 #define MQTT_MAX_TOPIC_SIZE 1024
43 #define MQTT_MAX_MESSAGE_SIZE MQTT_MAX_TOPIC_SIZE + 1024
44 #define MQTT_DEFAULT_HOST "localhost"
45 #define MQTT_DEFAULT_PORT 1883
46 #define MQTT_DEFAULT_TOPIC_PREFIX "collectd"
47 #define MQTT_DEFAULT_TOPIC "collectd/#"
49 /*
50 * Data types
51 */
52 struct mqtt_client_conf
53 {
54 _Bool publish;
55 char *name;
57 struct mosquitto *mosq;
58 _Bool connected;
60 char *host;
61 int port;
62 char *client_id;
63 char *username;
64 char *password;
65 int qos;
67 /* For publishing */
68 char *topic_prefix;
69 _Bool store_rates;
70 _Bool retain;
72 /* For subscribing */
73 pthread_t thread;
74 _Bool loop;
75 char *topic;
76 _Bool clean_session;
78 c_complain_t complaint_cantpublish;
79 pthread_mutex_t lock;
80 };
81 typedef struct mqtt_client_conf mqtt_client_conf_t;
83 static mqtt_client_conf_t **subscribers = NULL;
84 static size_t subscribers_num = 0;
86 /*
87 * Functions
88 */
89 static char const *mosquitto_strerror (int code)
90 {
91 switch (code)
92 {
93 case MOSQ_ERR_SUCCESS: return "MOSQ_ERR_SUCCESS";
94 case MOSQ_ERR_NOMEM: return "MOSQ_ERR_NOMEM";
95 case MOSQ_ERR_PROTOCOL: return "MOSQ_ERR_PROTOCOL";
96 case MOSQ_ERR_INVAL: return "MOSQ_ERR_INVAL";
97 case MOSQ_ERR_NO_CONN: return "MOSQ_ERR_NO_CONN";
98 case MOSQ_ERR_CONN_REFUSED: return "MOSQ_ERR_CONN_REFUSED";
99 case MOSQ_ERR_NOT_FOUND: return "MOSQ_ERR_NOT_FOUND";
100 case MOSQ_ERR_CONN_LOST: return "MOSQ_ERR_CONN_LOST";
101 case MOSQ_ERR_SSL: return "MOSQ_ERR_SSL";
102 case MOSQ_ERR_PAYLOAD_SIZE: return "MOSQ_ERR_PAYLOAD_SIZE";
103 case MOSQ_ERR_NOT_SUPPORTED: return "MOSQ_ERR_NOT_SUPPORTED";
104 case MOSQ_ERR_AUTH: return "MOSQ_ERR_AUTH";
105 case MOSQ_ERR_ACL_DENIED: return "MOSQ_ERR_ACL_DENIED";
106 case MOSQ_ERR_UNKNOWN: return "MOSQ_ERR_UNKNOWN";
107 case MOSQ_ERR_ERRNO: return "MOSQ_ERR_ERRNO";
108 }
110 return "UNKNOWN ERROR CODE";
111 }
113 static void mqtt_free (mqtt_client_conf_t *conf)
114 {
115 if (conf == NULL)
116 return;
118 if (conf->connected)
119 (void) mosquitto_disconnect (conf->mosq);
120 conf->connected = 0;
121 (void) mosquitto_destroy (conf->mosq);
123 sfree (conf->host);
124 sfree (conf->username);
125 sfree (conf->password);
126 sfree (conf->client_id);
127 sfree (conf->topic_prefix);
128 sfree (conf);
129 }
131 static char *strip_prefix (char *topic)
132 {
133 size_t num;
134 size_t i;
136 num = 0;
137 for (i = 0; topic[i] != 0; i++)
138 if (topic[i] == '/')
139 num++;
141 if (num < 2)
142 return (NULL);
144 while (num > 2)
145 {
146 char *tmp = strchr (topic, '/');
147 if (tmp == NULL)
148 return (NULL);
149 topic = tmp + 1;
150 num--;
151 }
153 return (topic);
154 }
156 static void on_message (__attribute__((unused)) void *arg,
157 const struct mosquitto_message *msg)
158 {
159 value_list_t vl = VALUE_LIST_INIT;
160 data_set_t const *ds;
161 char *topic;
162 char *name;
163 char *payload;
164 int status;
166 if ((msg->payloadlen <= 0) || (msg->payload[msg->payloadlen - 1] != 0))
167 return;
169 topic = strdup (msg->topic);
170 name = strip_prefix (topic);
172 status = parse_identifier_vl (name, &vl);
173 if (status != 0)
174 {
175 ERROR ("mqtt plugin: Unable to parse topic \"%s\".", topic);
176 sfree (topic);
177 return;
178 }
179 sfree (topic);
181 ds = plugin_get_ds (vl.type);
182 if (ds == NULL)
183 {
184 ERROR ("mqtt plugin: Unknown type: \"%s\".", vl.type);
185 return;
186 }
188 vl.values = calloc (ds->ds_num, sizeof (*vl.values));
189 if (vl.values == NULL)
190 {
191 ERROR ("mqtt plugin: calloc failed.");
192 return;
193 }
194 vl.values_len = ds->ds_num;
196 payload = strdup ((void *) msg->payload);
197 DEBUG ("mqtt plugin: payload = \"%s\"", payload);
198 status = parse_values (payload, &vl, ds);
199 if (status != 0)
200 {
201 ERROR ("mqtt plugin: Unable to parse payload \"%s\".", payload);
202 sfree (payload);
203 sfree (vl.values);
204 return;
205 }
206 sfree (payload);
208 plugin_dispatch_values (&vl);
209 sfree (vl.values);
210 } /* void on_message */
212 /* must hold conf->lock when calling. */
213 static int mqtt_reconnect (mqtt_client_conf_t *conf)
214 {
215 int status;
217 if (conf->connected)
218 return (0);
220 status = mosquitto_reconnect (conf->mosq);
221 if (status != MOSQ_ERR_SUCCESS)
222 {
223 char errbuf[1024];
224 ERROR ("mqtt_connect_broker: mosquitto_connect failed: %s",
225 (status == MOSQ_ERR_ERRNO)
226 ? sstrerror(errno, errbuf, sizeof (errbuf))
227 : mosquitto_strerror (status));
228 return (-1);
229 }
231 conf->connected = 1;
233 c_release (LOG_INFO,
234 &conf->complaint_cantpublish,
235 "mqtt plugin: successfully reconnected to broker \"%s:%d\"",
236 conf->host, conf->port);
238 return (0);
239 } /* mqtt_reconnect */
241 /* must hold conf->lock when calling. */
242 static int mqtt_connect (mqtt_client_conf_t *conf)
243 {
244 char const *client_id;
245 int status;
247 if (conf->mosq != NULL)
248 return mqtt_reconnect (conf);
250 if (conf->client_id)
251 client_id = conf->client_id;
252 else
253 client_id = hostname_g;
255 conf->mosq = mosquitto_new (client_id, /* user data = */ conf);
256 if (conf->mosq == NULL)
257 {
258 ERROR ("mqtt plugin: mosquitto_new failed");
259 return (-1);
260 }
262 if (conf->username && conf->password)
263 {
264 status = mosquitto_username_pw_set (conf->mosq, conf->username, conf->password);
265 if (status != MOSQ_ERR_SUCCESS)
266 {
267 char errbuf[1024];
268 ERROR ("mqtt plugin: mosquitto_username_pw_set failed: %s",
269 (status == MOSQ_ERR_ERRNO)
270 ? sstrerror (errno, errbuf, sizeof (errbuf))
271 : mosquitto_strerror (status));
273 mosquitto_destroy (conf->mosq);
274 conf->mosq = NULL;
275 return (-1);
276 }
277 }
279 status = mosquitto_connect (conf->mosq, conf->host, conf->port,
280 /* keepalive = */ 10, /* clean session = */ conf->clean_session);
281 if (status != MOSQ_ERR_SUCCESS)
282 {
283 char errbuf[1024];
284 ERROR ("mqtt plugin: mosquitto_connect failed: %s",
285 (status == MOSQ_ERR_ERRNO)
286 ? sstrerror (errno, errbuf, sizeof (errbuf))
287 : mosquitto_strerror (status));
289 mosquitto_destroy (conf->mosq);
290 conf->mosq = NULL;
291 return (-1);
292 }
294 if (!conf->publish)
295 {
296 mosquitto_message_callback_set (conf->mosq, on_message);
298 status = mosquitto_subscribe (conf->mosq, /* mid = */ NULL,
299 conf->topic, conf->qos);
300 if (status != MOSQ_ERR_SUCCESS)
301 {
302 ERROR ("mqtt plugin: Subscribing to \"%s\" failed: %s",
303 conf->topic, mosquitto_strerror (status));
305 mosquitto_disconnect (conf->mosq);
306 mosquitto_destroy (conf->mosq);
307 conf->mosq = NULL;
308 return (-1);
309 }
310 }
312 conf->connected = 1;
313 return (0);
314 } /* mqtt_connect */
316 static void *subscribers_thread (void *arg)
317 {
318 mqtt_client_conf_t *conf = arg;
319 int status;
321 conf->loop = 1;
323 while (conf->loop)
324 {
325 status = mqtt_connect (conf);
326 if (status != 0)
327 {
328 sleep (1);
329 continue;
330 }
332 /* The documentation says "0" would map to the default (1000ms), but
333 * that does not work on some versions. */
334 status = mosquitto_loop (conf->mosq, /* timeout = */ 1000 /* ms */);
335 if (status == MOSQ_ERR_CONN_LOST)
336 {
337 conf->connected = 0;
338 continue;
339 }
340 else if (status != MOSQ_ERR_SUCCESS)
341 {
342 ERROR ("mqtt plugin: mosquitto_loop failed: %s",
343 mosquitto_strerror (status));
344 mosquitto_destroy (conf->mosq);
345 conf->mosq = NULL;
346 conf->connected = 0;
347 continue;
348 }
350 DEBUG ("mqtt plugin: mosquitto_loop succeeded.");
351 } /* while (conf->loop) */
353 pthread_exit (0);
354 } /* void *subscribers_thread */
356 static int publish (mqtt_client_conf_t *conf, char const *topic,
357 void const *payload, size_t payload_len)
358 {
359 int status;
361 pthread_mutex_lock (&conf->lock);
363 status = mqtt_connect (conf);
364 if (status != 0) {
365 pthread_mutex_unlock (&conf->lock);
366 ERROR ("mqtt plugin: unable to reconnect to broker");
367 return (status);
368 }
370 status = mosquitto_publish(conf->mosq,
371 /* message id */ NULL,
372 topic,
373 (uint32_t) payload_len, payload,
374 /* qos */ conf->qos,
375 /* retain */ conf->retain);
376 if (status != MOSQ_ERR_SUCCESS)
377 {
378 char errbuf[1024];
379 c_complain (LOG_ERR,
380 &conf->complaint_cantpublish,
381 "plugin mqtt: mosquitto_publish failed: %s",
382 status == MOSQ_ERR_ERRNO ?
383 sstrerror(errno, errbuf, sizeof (errbuf)) :
384 mosquitto_strerror(status));
385 /* Mark our connection "down" regardless of the error as a safety
386 * measure; we will try to reconnect the next time we have to publish a
387 * message */
388 conf->connected = 0;
390 pthread_mutex_unlock (&conf->lock);
391 return (-1);
392 }
394 pthread_mutex_unlock (&conf->lock);
395 return (0);
396 } /* int publish */
398 static int format_topic (char *buf, size_t buf_len,
399 data_set_t const *ds, value_list_t const *vl,
400 mqtt_client_conf_t *conf)
401 {
402 char name[MQTT_MAX_TOPIC_SIZE];
403 int status;
405 if ((conf->topic_prefix == NULL) || (conf->topic_prefix[0] == 0))
406 return (FORMAT_VL (buf, buf_len, vl));
408 status = FORMAT_VL (name, sizeof (name), vl);
409 if (status != 0)
410 return (status);
412 status = ssnprintf (buf, buf_len, "%s/%s", conf->topic_prefix, name);
413 if ((status < 0) || (((size_t) status) >= buf_len))
414 return (ENOMEM);
416 return (0);
417 } /* int format_topic */
419 static int mqtt_write (const data_set_t *ds, const value_list_t *vl,
420 user_data_t *user_data)
421 {
422 mqtt_client_conf_t *conf;
423 char topic[MQTT_MAX_TOPIC_SIZE];
424 char payload[MQTT_MAX_MESSAGE_SIZE];
425 int status = 0;
427 if ((user_data == NULL) || (user_data->data == NULL))
428 return (EINVAL);
429 conf = user_data->data;
431 status = format_topic (topic, sizeof (topic), ds, vl, conf);
432 if (status != 0)
433 {
434 ERROR ("mqtt plugin: format_topic failed with status %d.", status);
435 return (status);
436 }
438 status = format_values (payload, sizeof (payload),
439 ds, vl, conf->store_rates);
440 if (status != 0)
441 {
442 ERROR ("mqtt plugin: format_values failed with status %d.", status);
443 return (status);
444 }
446 status = publish (conf, topic, payload, strlen (payload) + 1);
447 if (status != 0)
448 {
449 ERROR ("mqtt plugin: publish failed: %s", mosquitto_strerror (status));
450 return (status);
451 }
453 return (status);
454 } /* mqtt_write */
456 /*
457 * <Publish "name">
458 * Host "example.com"
459 * Port 1883
460 * ClientId "collectd"
461 * User "guest"
462 * Password "secret"
463 * Prefix "collectd"
464 * StoreRates true
465 * Retain false
466 * QoS 0
467 * </Publish>
468 */
469 static int mqtt_config_publisher (oconfig_item_t *ci)
470 {
471 mqtt_client_conf_t *conf;
472 user_data_t user_data;
473 int status;
474 int i;
476 conf = calloc (1, sizeof (*conf));
477 if (conf == NULL)
478 {
479 ERROR ("mqtt plugin: malloc failed.");
480 return (-1);
481 }
482 conf->publish = 1;
484 conf->name = NULL;
485 status = cf_util_get_string (ci, &conf->name);
486 if (status != 0)
487 {
488 mqtt_free (conf);
489 return (status);
490 }
492 conf->host = strdup (MQTT_DEFAULT_HOST);
493 conf->port = MQTT_DEFAULT_PORT;
494 conf->client_id = NULL;
495 conf->topic_prefix = strdup (MQTT_DEFAULT_TOPIC_PREFIX);
497 C_COMPLAIN_INIT (&conf->complaint_cantpublish);
499 for (i = 0; i < ci->children_num; i++)
500 {
501 oconfig_item_t *child = ci->children + i;
502 if (strcasecmp ("Host", child->key) == 0)
503 cf_util_get_string (child, &conf->host);
504 else if (strcasecmp ("Port", child->key) == 0)
505 {
506 int tmp = cf_util_get_port_number (child);
507 if (tmp < 0)
508 ERROR ("mqtt plugin: Invalid port number.");
509 else
510 conf->port = tmp;
511 }
512 else if (strcasecmp ("ClientId", child->key) == 0)
513 cf_util_get_string (child, &conf->client_id);
514 else if (strcasecmp ("User", child->key) == 0)
515 cf_util_get_string (child, &conf->username);
516 else if (strcasecmp ("Password", child->key) == 0)
517 cf_util_get_string (child, &conf->password);
518 else if (strcasecmp ("QoS", child->key) == 0)
519 {
520 int tmp = -1;
521 status = cf_util_get_int (child, &tmp);
522 if ((status != 0) || (tmp < 0) || (tmp > 2))
523 ERROR ("mqtt plugin: Not a valid QoS setting.");
524 else
525 conf->qos = tmp;
526 }
527 else if (strcasecmp ("Prefix", child->key) == 0)
528 cf_util_get_string (child, &conf->topic_prefix);
529 else if (strcasecmp ("StoreRates", child->key) == 0)
530 cf_util_get_boolean (child, &conf->store_rates);
531 else if (strcasecmp ("Retain", child->key) == 0)
532 cf_util_get_boolean (child, &conf->retain);
533 else
534 ERROR ("mqtt plugin: Unknown config option: %s", child->key);
535 }
537 memset (&user_data, 0, sizeof (user_data));
538 user_data.data = conf;
540 plugin_register_write ("mqtt", mqtt_write, &user_data);
541 return (0);
542 } /* mqtt_config_publisher */
544 /*
545 * <Subscribe "name">
546 * Host "example.com"
547 * Port 1883
548 * ClientId "collectd"
549 * User "guest"
550 * Password "secret"
551 * Topic "collectd/#"
552 * </Publish>
553 */
554 static int mqtt_config_subscriber (oconfig_item_t *ci)
555 {
556 mqtt_client_conf_t **tmp;
557 mqtt_client_conf_t *conf;
558 int status;
559 int i;
561 conf = calloc (1, sizeof (*conf));
562 if (conf == NULL)
563 {
564 ERROR ("mqtt plugin: malloc failed.");
565 return (-1);
566 }
567 conf->publish = 0;
569 conf->name = NULL;
570 status = cf_util_get_string (ci, &conf->name);
571 if (status != 0)
572 {
573 mqtt_free (conf);
574 return (status);
575 }
577 conf->host = strdup (MQTT_DEFAULT_HOST);
578 conf->port = MQTT_DEFAULT_PORT;
579 conf->client_id = NULL;
580 conf->topic = strdup (MQTT_DEFAULT_TOPIC);
582 C_COMPLAIN_INIT (&conf->complaint_cantpublish);
584 for (i = 0; i < ci->children_num; i++)
585 {
586 oconfig_item_t *child = ci->children + i;
587 if (strcasecmp ("Host", child->key) == 0)
588 cf_util_get_string (child, &conf->host);
589 else if (strcasecmp ("Port", child->key) == 0)
590 {
591 int tmp = cf_util_get_port_number (child);
592 if (tmp < 0)
593 ERROR ("mqtt plugin: Invalid port number.");
594 else
595 conf->port = tmp;
596 }
597 else if (strcasecmp ("ClientId", child->key) == 0)
598 cf_util_get_string (child, &conf->client_id);
599 else if (strcasecmp ("User", child->key) == 0)
600 cf_util_get_string (child, &conf->username);
601 else if (strcasecmp ("Password", child->key) == 0)
602 cf_util_get_string (child, &conf->password);
603 else if (strcasecmp ("QoS", child->key) == 0)
604 {
605 int tmp = -1;
606 status = cf_util_get_int (child, &tmp);
607 if ((status != 0) || (tmp < 0) || (tmp > 2))
608 ERROR ("mqtt plugin: Not a valid QoS setting.");
609 else
610 conf->qos = tmp;
611 }
612 else if (strcasecmp ("Topic", child->key) == 0)
613 cf_util_get_string (child, &conf->topic);
614 else if (strcasecmp ("CleanSession", child->key) == 0)
615 cf_util_get_boolean (child, &conf->clean_session);
616 else
617 ERROR ("mqtt plugin: Unknown config option: %s", child->key);
618 }
620 tmp = realloc (subscribers, sizeof (*subscribers) * subscribers_num);
621 if (tmp == NULL)
622 {
623 ERROR ("mqtt plugin: realloc failed.");
624 mqtt_free (conf);
625 return (-1);
626 }
627 subscribers = tmp;
628 subscribers[subscribers_num] = conf;
629 subscribers_num++;
631 return (0);
632 } /* mqtt_config_subscriber */
634 /*
635 * <Plugin mqtt>
636 * <Publish "name">
637 * # ...
638 * </Publish>
639 * <Subscribe "name">
640 * # ...
641 * </Subscribe>
642 * </Plugin>
643 */
644 static int mqtt_config (oconfig_item_t *ci)
645 {
646 int i;
648 for (i = 0; i < ci->children_num; i++)
649 {
650 oconfig_item_t *child = ci->children + i;
652 if (strcasecmp ("Publish", child->key) == 0)
653 mqtt_config_publisher (child);
654 else if (strcasecmp ("Subscribe", child->key) == 0)
655 mqtt_config_subscriber (child);
656 else
657 ERROR ("mqtt plugin: Unknown config option: %s", child->key);
658 }
660 return (0);
661 } /* int mqtt_config */
663 static int mqtt_init (void)
664 {
665 size_t i;
667 mosquitto_lib_init ();
669 for (i = 0; i < subscribers_num; i++)
670 {
671 int status;
673 if (subscribers[i]->loop)
674 continue;
676 status = plugin_thread_create (&subscribers[i]->thread,
677 /* attrs = */ NULL,
678 /* func = */ subscribers_thread,
679 /* args = */ subscribers[i]);
680 if (status != 0)
681 {
682 char errbuf[1024];
683 ERROR ("mqtt plugin: pthread_create failed: %s",
684 sstrerror (errno, errbuf, sizeof (errbuf)));
685 continue;
686 }
687 }
689 return (0);
690 } /* mqtt_init */
692 void module_register (void)
693 {
694 plugin_register_complex_config ("mqtt", mqtt_config);
695 plugin_register_init ("mqtt", mqtt_init);
696 } /* void module_register */
698 /* vim: set sw=4 sts=4 et fdm=marker : */