2 * collectd - src/erlang.c
3 * Copyright (C) 2009 Florian octo Forster
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; only version 2 of the License is applicable.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 * Florian octo Forster <octo at verplant.org>
25 #include <sys/types.h>
26 #include <sys/socket.h>
27 #include <netinet/in.h>
32 #include <erl_interface.h>
36 * Private data structures
38 struct ce_connection_info_s
43 typedef struct ce_connection_info_s ce_connection_info_t;
48 static pthread_t listen_thread_id;
49 static _Bool listen_thread_running = false;
51 static char conf_service[NI_MAXSERV] = "29157";
52 static char conf_cookie[256] = "ceisaequ";
57 static int send_atom (int fd, ETERM *to, const char *atom) /* {{{ */
62 reply = erl_mk_atom (atom);
66 status = erl_send (fd, to, reply);
67 erl_free_term (reply);
73 } /* }}} int send_atom */
75 static int send_error (int fd, ETERM *to, const char *message) /* {{{ */
80 DEBUG ("erlang plugin: send_error: message = %s.", message);
81 reply = erl_format ("{~a,~s}", "error", message);
83 status = erl_send (fd, to, reply);
89 erl_free_term (reply);
92 } /* }}} int send_error */
94 static int eterm_to_int (const ETERM *term, int *ret_int) /* {{{ */
96 if ((term == NULL) || (ret_int == NULL))
99 switch (ERL_TYPE (term))
102 *ret_int = (int) ERL_INT_VALUE (term);
106 *ret_int = (int) ERL_INT_UVALUE (term);
110 *ret_int = (int) (ERL_FLOAT_VALUE (term) + .5);
114 *ret_int = (int) ERL_LL_VALUE (term);
118 *ret_int = (int) ERL_LL_UVALUE (term);
122 ERROR ("erlang plugin: Don't know how to cast "
123 "erlang type %#x to int.", (unsigned int) ERL_TYPE (term));
125 } /* switch (ERL_TYPE (term)) */
128 } /* }}} int eterm_to_int */
130 static int eterm_to_time_t (const ETERM *term, time_t *ret_time) /* {{{ */
132 if ((term == NULL) || (ret_time == NULL))
135 if (ERL_IS_NIL (term)
136 || (ERL_IS_ATOM (term)
137 && ((strcmp ("now", ERL_ATOM_PTR (term)) == 0)
138 || (strcmp ("undefined", ERL_ATOM_PTR (term)) == 0))))
140 *ret_time = time (NULL);
144 switch (ERL_TYPE (term))
147 *ret_time = (time_t) ERL_INT_VALUE (term);
151 *ret_time = (time_t) ERL_INT_UVALUE (term);
155 if ((strcmp ("now", ERL_ATOM_PTR (term)) == 0)
156 || (strcmp ("undefined", ERL_ATOM_PTR (term)) == 0))
158 *ret_time = time (NULL);
162 ERROR ("erlang plugin: Invalid atom for time: %s.",
163 ERL_ATOM_PTR (term));
169 *ret_time = (time_t) (ERL_FLOAT_VALUE (term) + .5);
173 *ret_time = (time_t) ERL_LL_VALUE (term);
177 *ret_time = (time_t) ERL_LL_UVALUE (term);
181 ERROR ("erlang plugin: Don't know how to cast "
182 "erlang type %#x to time_t.", (unsigned int) ERL_TYPE (term));
184 } /* switch (ERL_TYPE (term)) */
187 } /* }}} int eterm_to_time_t */
189 static int eterm_to_string (const ETERM *term, char *buffer, size_t buffer_size) /* {{{ */
193 if ((term == NULL) || (buffer == NULL) || (buffer_size <= 0))
196 memset (buffer, 0, buffer_size);
198 if (ERL_IS_EMPTY_LIST (term)
200 || (ERL_IS_ATOM (term)
201 && (strcmp ("undefined", ERL_ATOM_PTR (term)) == 0)))
207 if (!ERL_IS_LIST (term))
210 tmp = erl_iolist_to_string (term);
214 strncpy (buffer, tmp, buffer_size - 1);
218 } /* }}} int eterm_to_string */
220 static int eterm_to_value (const ETERM *term, int ds_type, /* {{{ */
223 if ((term == NULL) || (value == NULL))
226 switch (ERL_TYPE (term))
230 int v = ERL_INT_VALUE (term);
233 case DS_TYPE_COUNTER: value->counter = (counter_t) v; break;
234 case DS_TYPE_GAUGE: value->gauge = (gauge_t) v; break;
235 case DS_TYPE_DERIVE: value->derive = (derive_t) v; break;
236 case DS_TYPE_ABSOLUTE: value->absolute = (absolute_t) v; break;
243 unsigned int v = ERL_INT_UVALUE (term);
246 case DS_TYPE_COUNTER: value->counter = (counter_t) v; break;
247 case DS_TYPE_GAUGE: value->gauge = (gauge_t) v; break;
248 case DS_TYPE_DERIVE: value->derive = (derive_t) v; break;
249 case DS_TYPE_ABSOLUTE: value->absolute = (absolute_t) v; break;
256 double v = ERL_FLOAT_VALUE (term);
259 case DS_TYPE_COUNTER: value->counter = (counter_t) v; break;
260 case DS_TYPE_GAUGE: value->gauge = (gauge_t) v; break;
261 case DS_TYPE_DERIVE: value->derive = (derive_t) v; break;
262 case DS_TYPE_ABSOLUTE: value->absolute = (absolute_t) v; break;
269 long long v = ERL_LL_VALUE (term);
272 case DS_TYPE_COUNTER: value->counter = (counter_t) v; break;
273 case DS_TYPE_GAUGE: value->gauge = (gauge_t) v; break;
274 case DS_TYPE_DERIVE: value->derive = (derive_t) v; break;
275 case DS_TYPE_ABSOLUTE: value->absolute = (absolute_t) v; break;
282 unsigned long long v = ERL_LL_UVALUE (term);
285 case DS_TYPE_COUNTER: value->counter = (counter_t) v; break;
286 case DS_TYPE_GAUGE: value->gauge = (gauge_t) v; break;
287 case DS_TYPE_DERIVE: value->derive = (derive_t) v; break;
288 case DS_TYPE_ABSOLUTE: value->absolute = (absolute_t) v; break;
294 ERROR ("erlang plugin: Don't know how to cast "
295 "erlang type %#x to value_t.", (unsigned int) ERL_TYPE (term));
297 } /* switch (ERL_TYPE (term)) */
300 } /* }}} int eterm_to_value */
302 static int eterm_to_values (const ETERM *term, const data_set_t *ds, /* {{{ */
308 if ((term == NULL) || (ds == NULL) || (vl == NULL))
311 if (!ERL_IS_LIST (term))
318 while (!ERL_IS_EMPTY_LIST (term))
320 const ETERM *eterm_value;
323 if (ds_index >= ds->ds_num)
325 ds_index = ds->ds_num + 1;
330 tmp = realloc (vl->values, sizeof (*tmp) * (vl->values_len + 1));
338 eterm_value = ERL_CONS_HEAD (term);
339 term = ERL_CONS_TAIL (term);
341 status = eterm_to_value (eterm_value, ds->ds[ds_index].type,
342 vl->values + vl->values_len);
350 if ((status == 0) && (ds_index != ds->ds_num))
351 NOTICE ("erlang plugin: Incorrect number of values received for type %s: "
352 "Expected %i, got %i.", ds->type, ds->ds_num, ds_index);
354 if ((status != 0) || (ds_index != ds->ds_num))
363 } /* }}} int eterm_to_values */
365 static int eterm_to_value_list (const ETERM *term, value_list_t *vl) /* {{{ */
369 const data_set_t *ds;
371 if ((term == NULL) || (vl == NULL))
374 if (!ERL_IS_TUPLE (term) || (ERL_TUPLE_SIZE (term) != 9))
377 tmp = erl_element (1, term);
378 if (!ERL_IS_ATOM (tmp)
379 || (strcmp ("value_list", ERL_ATOM_PTR (tmp)) != 0))
389 #define TUPLE_ELEM_TO_CHAR_ARRAY(idx,buf) \
390 tmp = erl_element ((idx), term); \
391 status = eterm_to_string (tmp, (buf), sizeof (buf)); \
392 erl_free_term (tmp); \
396 TUPLE_ELEM_TO_CHAR_ARRAY (2, vl->host);
397 TUPLE_ELEM_TO_CHAR_ARRAY (3, vl->plugin);
398 TUPLE_ELEM_TO_CHAR_ARRAY (4, vl->plugin_instance);
399 TUPLE_ELEM_TO_CHAR_ARRAY (5, vl->type);
400 TUPLE_ELEM_TO_CHAR_ARRAY (6, vl->type_instance);
402 ds = plugin_get_ds (vl->type);
409 tmp = erl_element (7, term);
410 status = eterm_to_time_t (tmp, &vl->time);
415 tmp = erl_element (8, term);
416 status = eterm_to_int (tmp, &vl->interval);
420 if (vl->interval < 1)
421 vl->interval = interval_g;
423 tmp = erl_element (9, term);
424 status = eterm_to_values (tmp, ds, vl);
429 #undef TUPLE_ELEM_TO_CHAR_ARRAY
435 /* validate the struct */
436 if ((vl->host[0] == 0) || (vl->plugin[0] == 0) || (vl->type[0] == 0))
439 if (ds->ds_num != vl->values_len)
443 } /* }}} int eterm_to_value_list */
445 /* Returns non-zero only if the request could not be handled gracefully. */
446 static int handle_dispatch_values (ce_connection_info_t *cinfo, /* {{{ */
447 const ErlMessage *req)
453 memset (&vl, 0, sizeof (vl));
456 eterm_vl = erl_element (2, req->msg);
457 status = eterm_to_value_list (eterm_vl, &vl);
458 erl_free_term (eterm_vl);
463 send_error (cinfo->fd, req->from, "Cannot parse argument as value list.");
467 status = plugin_dispatch_values (&vl);
471 send_error (cinfo->fd, req->from, "plugin_dispatch_values failed.");
476 send_atom (cinfo->fd, req->from, "success");
479 } /* }}} int handle_dispatch_values */
481 static void *handle_client_thread (void *arg) /* {{{ */
483 ce_connection_info_t *cinfo;
485 unsigned char buffer[4096];
489 DEBUG ("erlang plugin: handle_client_thread[%i]: Handling client %s.",
490 cinfo->fd, cinfo->conn.nodename);
500 erl_free_term (emsg.from);
502 erl_free_term (emsg.to);
504 erl_free_term (emsg.msg);
507 status = erl_receive_msg (cinfo->fd, buffer, sizeof (buffer), &emsg);
508 if (status == ERL_TICK)
511 if (status == ERL_ERROR)
514 if (emsg.type == ERL_REG_SEND)
519 if (!ERL_IS_TUPLE (emsg.msg))
521 ERROR ("erlang plugin: Message is not a tuple.");
522 send_atom (cinfo->fd, emsg.from, "error");
526 func = erl_element (1, emsg.msg);
527 if (!ERL_IS_ATOM (func))
529 ERROR ("erlang plugin: First element is not an atom!");
530 send_atom (cinfo->fd, emsg.from, "error");
531 erl_free_term (func);
535 DEBUG ("erlang plugin: Wanted function is: %s.", ERL_ATOM_PTR (func));
537 if (strcmp ("dispatch_values", ERL_ATOM_PTR (func)) == 0)
538 status = handle_dispatch_values (cinfo, &emsg);
541 ERROR ("erlang plugin: Received request for invalid function `%s'.",
542 ERL_ATOM_PTR (func));
543 send_atom (cinfo->fd, emsg.from, "error");
547 /* Check for fatal errors in the callback functions. */
550 ERROR ("erlang plugin: Handling request for `%s' failed.",
551 ERL_ATOM_PTR (func));
552 erl_free_term (func);
556 erl_free_term (func);
558 else if (emsg.type == ERL_EXIT)
560 DEBUG ("erlang plugin: handle_client_thread[%i]: "
561 "Received exit message.", cinfo->fd);
566 ERROR ("erlang plugin: Message type not handled: %i.", emsg.type);
570 erl_free_term (emsg.from);
572 erl_free_term (emsg.to);
574 erl_free_term (emsg.msg);
577 DEBUG ("erlang plugin: handle_client_thread[%i]: Exiting.", cinfo->fd);
582 pthread_exit ((void *) 0);
584 } /* }}} void *handle_client_thread */
586 static int create_listen_socket (void) /* {{{ */
588 struct addrinfo ai_hints;
589 struct addrinfo *ai_list;
590 struct addrinfo *ai_ptr;
597 memset (&ai_hints, 0, sizeof (ai_hints));
598 /* AI_PASSIVE => returns INADDR_ANY */
599 ai_hints.ai_flags = AI_PASSIVE;
601 ai_hints.ai_flags |= AI_ADDRCONFIG;
604 ai_hints.ai_family = AF_INET;
605 ai_hints.ai_socktype = SOCK_STREAM;
608 status = getaddrinfo (/* node = */ NULL, /* service = */ conf_service,
609 &ai_hints, &ai_list);
612 ERROR ("erlang plugin: getaddrinfo failed: %s", gai_strerror (status));
616 for (ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
618 struct sockaddr_in *sa_in;
619 struct in_addr *sin_addr;
622 assert (ai_ptr->ai_family == AF_INET);
623 sa_in = (struct sockaddr_in *) ai_ptr->ai_addr;
624 sin_addr = &sa_in->sin_addr;
625 numeric_serv = (int) ntohs (sa_in->sin_port);
627 /* Dunno if calling this multiple times is legal. Since it wants to have
628 * the sin_addr for some reason this is the best place to call this,
630 status = erl_connect_xinit (/* host name = */ "leeloo",
631 /* plain node name = */ "collectd",
632 /* full node name = */ "collectd@leeloo.lan.home.verplant.org",
633 /* our address = */ sin_addr,
634 /* secret cookie = */ conf_cookie,
635 /* instance number = */ 0);
638 ERROR ("erlang plugin: erl_connect_xinit failed with status %i.",
643 sock_descr = socket (ai_ptr->ai_family, ai_ptr->ai_socktype,
644 ai_ptr->ai_protocol);
647 ERROR ("erlang plugin: socket(2) failed.");
652 status = setsockopt (sock_descr, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
655 ERROR ("erlang plugin: setsockopt(2) failed.");
661 status = bind (sock_descr, ai_ptr->ai_addr, ai_ptr->ai_addrlen);
664 ERROR ("erlang plugin: bind(2) failed.");
670 status = listen (sock_descr, /* backlog = */ 10);
673 ERROR ("erlang plugin: listen(2) failed.");
680 } /* for (ai_list) */
682 freeaddrinfo (ai_list);
686 status = erl_publish (numeric_serv);
689 ERROR ("erlang plugin: erl_publish (%i) failed with status %i.", numeric_serv, status);
697 } /* }}} int create_listen_socket */
699 void *listen_thread (void *arg) /* {{{ */
706 /* I have no fucking idea what this does, nor what the arguments are. Didn't
707 * find any comprehensive docs yet. */
708 erl_init (/* void *x = */ NULL, /* long y = */ 0);
710 listen = create_listen_socket ();
717 pthread_attr_t tattr;
718 ce_connection_info_t *arg;
720 fd = erl_accept (listen, &conn);
723 ERROR ("erlang plugin: erl_accept failed with status %i.", fd);
727 DEBUG ("erlang plugin: Got connection from %s on fd %i.",
730 pthread_attr_init (&tattr);
731 pthread_attr_setdetachstate (&tattr, PTHREAD_CREATE_DETACHED);
733 arg = malloc (sizeof (*arg));
736 ERROR ("erlang plugin: malloc failed.");
740 memset (arg, 0, sizeof (*arg));
743 memcpy (&arg->conn, &conn, sizeof (conn));
745 pthread_create (&tid, &tattr, handle_client_thread, arg);
748 pthread_exit ((void *) 0);
750 } /* }}} void *listen_thread */
752 static int ce_init (void) /* {{{ */
754 if (!listen_thread_running)
758 status = pthread_create (&listen_thread_id,
763 listen_thread_running = true;
767 } /* }}} int ce_init */
769 void module_register (void)
771 plugin_register_init ("erlang", ce_init);
774 /* vim: set sw=2 ts=2 noet fdm=marker : */