d10b4ea737417a0f207ad3122a9683438e4c9955
1 /**
2 * collectd - src/lua.c
3 * Copyright (C) 2010 Julien Ammous
4 * Copyright (C) 2010 Florian Forster
5 * Copyright (C) 2016 Ruben Kerkhof
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 *
25 * Authors:
26 * Julien Ammous
27 * Florian Forster <octo at collectd.org>
28 * Ruben Kerkhof <ruben at rubenkerkhof.com>
29 **/
31 /* <lua5.1/luaconf.h> defines a macro using "sprintf". Although not used here,
32 * GCC will complain about the macro definition. */
33 #define DONT_POISON_SPRINTF_YET
35 #include "collectd.h"
36 #include "common.h"
37 #include "plugin.h"
39 /* Include the Lua API header files. */
40 #include "utils_lua.h"
41 #include <lauxlib.h>
42 #include <lua.h>
43 #include <lualib.h>
45 #include <pthread.h>
47 #if COLLECT_DEBUG && __GNUC__
48 #undef sprintf
49 #pragma GCC poison sprintf
50 #endif
52 typedef struct lua_script_s {
53 char *script_path;
54 lua_State *lua_state;
55 struct lua_script_s *next;
56 } lua_script_t;
58 typedef struct {
59 lua_State *lua_state;
60 const char *lua_function_name;
61 pthread_mutex_t lock;
62 int callback_id;
63 } clua_callback_data_t;
65 static char base_path[PATH_MAX];
66 static lua_script_t *scripts;
68 static int clua_store_callback(lua_State *L, int idx) /* {{{ */
69 {
70 /* Copy the function pointer */
71 lua_pushvalue(L, idx);
73 return luaL_ref(L, LUA_REGISTRYINDEX);
74 } /* }}} int clua_store_callback */
76 static int clua_load_callback(lua_State *L, int callback_ref) /* {{{ */
77 {
78 lua_rawgeti(L, LUA_REGISTRYINDEX, callback_ref);
80 if (!lua_isfunction(L, -1)) {
81 lua_pop(L, 1);
82 return (-1);
83 }
85 return (0);
86 } /* }}} int clua_load_callback */
88 /* Store the threads in a global variable so they are not cleaned up by the
89 * garbage collector. */
90 static int clua_store_thread(lua_State *L, int idx) /* {{{ */
91 {
92 if (idx < 0)
93 idx += lua_gettop(L) + 1;
95 /* Copy the thread pointer */
96 lua_pushvalue(L, idx); /* +1 = 3 */
97 if (!lua_isthread(L, -1)) {
98 lua_pop(L, 3); /* -3 = 0 */
99 return (-1);
100 }
102 luaL_ref(L, LUA_REGISTRYINDEX);
103 lua_pop(L, 1); /* -1 = 0 */
104 return (0);
105 } /* }}} int clua_store_thread */
107 static int clua_read(user_data_t *ud) /* {{{ */
108 {
109 clua_callback_data_t *cb = ud->data;
111 pthread_mutex_lock(&cb->lock);
113 lua_State *L = cb->lua_state;
115 int status = clua_load_callback(L, cb->callback_id);
116 if (status != 0) {
117 ERROR("Lua plugin: Unable to load callback \"%s\" (id %i).",
118 cb->lua_function_name, cb->callback_id);
119 pthread_mutex_unlock(&cb->lock);
120 return (-1);
121 }
122 /* +1 = 1 */
124 status = lua_pcall(L, 0, 1, 0);
125 if (status != 0) {
126 const char *errmsg = lua_tostring(L, -1);
127 if (errmsg == NULL)
128 ERROR("Lua plugin: Calling a read callback failed. "
129 "In addition, retrieving the error message failed.");
130 else
131 ERROR("Lua plugin: Calling a read callback failed: %s", errmsg);
132 lua_pop(L, 1);
133 pthread_mutex_unlock(&cb->lock);
134 return (-1);
135 }
137 if (!lua_isnumber(L, -1)) {
138 ERROR("Lua plugin: Read function \"%s\" (id %i) did not return a numeric "
139 "status.",
140 cb->lua_function_name, cb->callback_id);
141 status = -1;
142 } else {
143 status = (int)lua_tointeger(L, -1);
144 }
146 /* pop return value and function */
147 lua_pop(L, 1); /* -1 = 0 */
149 pthread_mutex_unlock(&cb->lock);
150 return (status);
151 } /* }}} int clua_read */
153 static int clua_write(const data_set_t *ds, const value_list_t *vl, /* {{{ */
154 user_data_t *ud) {
155 clua_callback_data_t *cb = ud->data;
157 pthread_mutex_lock(&cb->lock);
159 lua_State *L = cb->lua_state;
161 int status = clua_load_callback(L, cb->callback_id);
162 if (status != 0) {
163 ERROR("Lua plugin: Unable to load callback \"%s\" (id %i).",
164 cb->lua_function_name, cb->callback_id);
165 pthread_mutex_unlock(&cb->lock);
166 return (-1);
167 }
168 /* +1 = 1 */
170 status = luaC_pushvaluelist(L, ds, vl);
171 if (status != 0) {
172 lua_pop(L, 1); /* -1 = 0 */
173 pthread_mutex_unlock(&cb->lock);
174 ERROR("Lua plugin: luaC_pushvaluelist failed.");
175 return (-1);
176 }
177 /* +1 = 2 */
179 status = lua_pcall(L, 1, 1, 0); /* -2+1 = 1 */
180 if (status != 0) {
181 const char *errmsg = lua_tostring(L, -1);
182 if (errmsg == NULL)
183 ERROR("Lua plugin: Calling the write callback failed. "
184 "In addition, retrieving the error message failed.");
185 else
186 ERROR("Lua plugin: Calling the write callback failed:\n%s", errmsg);
187 lua_pop(L, 1); /* -1 = 0 */
188 pthread_mutex_unlock(&cb->lock);
189 return (-1);
190 }
192 if (!lua_isnumber(L, -1)) {
193 ERROR("Lua plugin: Write function \"%s\" (id %i) did not return a numeric "
194 "value.",
195 cb->lua_function_name, cb->callback_id);
196 status = -1;
197 } else {
198 status = (int)lua_tointeger(L, -1);
199 }
201 lua_pop(L, 1); /* -1 = 0 */
202 pthread_mutex_unlock(&cb->lock);
203 return (status);
204 } /* }}} int clua_write */
206 /*
207 * Exported functions
208 */
210 static int lua_cb_log_debug(lua_State *L) /* {{{ */
211 {
212 const char *msg = luaL_checkstring(L, 1);
213 plugin_log(LOG_DEBUG, "%s", msg);
214 return 0;
215 } /* }}} int lua_cb_log_debug */
217 static int lua_cb_log_error(lua_State *L) /* {{{ */
218 {
219 const char *msg = luaL_checkstring(L, 1);
220 plugin_log(LOG_ERR, "%s", msg);
221 return 0;
222 } /* }}} int lua_cb_log_error */
224 static int lua_cb_log_info(lua_State *L) /* {{{ */
225 {
226 const char *msg = luaL_checkstring(L, 1);
227 plugin_log(LOG_INFO, "%s", msg);
228 return 0;
229 } /* }}} int lua_cb_log_info */
231 static int lua_cb_log_notice(lua_State *L) /* {{{ */
232 {
233 const char *msg = luaL_checkstring(L, 1);
234 plugin_log(LOG_NOTICE, "%s", msg);
235 return 0;
236 } /* }}} int lua_cb_log_notice */
238 static int lua_cb_log_warning(lua_State *L) /* {{{ */
239 {
240 const char *msg = luaL_checkstring(L, 1);
241 plugin_log(LOG_WARNING, "%s", msg);
242 return 0;
243 } /* }}} int lua_cb_log_warning */
245 static int lua_cb_dispatch_values(lua_State *L) /* {{{ */
246 {
247 int nargs = lua_gettop(L);
249 if (nargs != 1)
250 return luaL_error(L, "Invalid number of arguments (%d != 1)", nargs);
252 luaL_checktype(L, 1, LUA_TTABLE);
254 value_list_t *vl = luaC_tovaluelist(L, -1);
255 if (vl == NULL)
256 return luaL_error(L, "%s", "luaC_tovaluelist failed");
258 #if COLLECT_DEBUG
259 char identifier[6 * DATA_MAX_NAME_LEN];
260 FORMAT_VL(identifier, sizeof(identifier), vl);
262 DEBUG("Lua plugin: collectd.dispatch_values(): Received value list \"%s\", "
263 "time %.3f, interval %.3f.",
264 identifier, CDTIME_T_TO_DOUBLE(vl->time),
265 CDTIME_T_TO_DOUBLE(vl->interval));
266 #endif
268 plugin_dispatch_values(vl);
270 sfree(vl->values);
271 sfree(vl);
272 return 0;
273 } /* }}} lua_cb_dispatch_values */
275 static int lua_cb_register_read(lua_State *L) /* {{{ */
276 {
277 int nargs = lua_gettop(L);
279 if (nargs != 1)
280 return luaL_error(L, "Invalid number of arguments (%d != 1)", nargs);
282 luaL_checktype(L, 1, LUA_TFUNCTION);
284 char function_name[DATA_MAX_NAME_LEN];
285 ssnprintf(function_name, sizeof(function_name), "lua/%s", lua_tostring(L, 1));
287 int callback_id = clua_store_callback(L, 1);
288 if (callback_id < 0)
289 return luaL_error(L, "%s", "Storing callback function failed");
291 lua_State *thread = lua_newthread(L);
292 if (thread == NULL)
293 return luaL_error(L, "%s", "lua_newthread failed");
294 clua_store_thread(L, -1);
295 lua_pop(L, 1);
297 clua_callback_data_t *cb = calloc(1, sizeof(*cb));
298 if (cb == NULL)
299 return luaL_error(L, "%s", "calloc failed");
301 cb->lua_state = thread;
302 cb->callback_id = callback_id;
303 cb->lua_function_name = strdup(function_name);
304 pthread_mutex_init(&cb->lock, NULL);
306 int status = plugin_register_complex_read(/* group = */ "lua",
307 /* name = */ function_name,
308 /* callback = */ clua_read,
309 /* interval = */ 0,
310 &(user_data_t) {
311 .data = cb,
312 });
314 if (status != 0)
315 return luaL_error(L, "%s", "plugin_register_complex_read failed");
316 return 0;
317 } /* }}} int lua_cb_register_read */
319 static int lua_cb_register_write(lua_State *L) /* {{{ */
320 {
321 int nargs = lua_gettop(L);
323 if (nargs != 1)
324 return luaL_error(L, "Invalid number of arguments (%d != 1)", nargs);
326 luaL_checktype(L, 1, LUA_TFUNCTION);
328 char function_name[DATA_MAX_NAME_LEN] = "";
329 ssnprintf(function_name, sizeof(function_name), "lua/%s", lua_tostring(L, 1));
331 int callback_id = clua_store_callback(L, 1);
332 if (callback_id < 0)
333 return luaL_error(L, "%s", "Storing callback function failed");
335 lua_State *thread = lua_newthread(L);
336 if (thread == NULL)
337 return luaL_error(L, "%s", "lua_newthread failed");
338 clua_store_thread(L, -1);
339 lua_pop(L, 1);
341 clua_callback_data_t *cb = calloc(1, sizeof(*cb));
342 if (cb == NULL)
343 return luaL_error(L, "%s", "calloc failed");
345 cb->lua_state = thread;
346 cb->callback_id = callback_id;
347 cb->lua_function_name = strdup(function_name);
348 pthread_mutex_init(&cb->lock, NULL);
350 int status = plugin_register_write(/* name = */ function_name,
351 /* callback = */ clua_write,
352 &(user_data_t) {
353 .data = cb,
354 });
356 if (status != 0)
357 return luaL_error(L, "%s", "plugin_register_write failed");
358 return 0;
359 } /* }}} int lua_cb_register_write */
361 static const luaL_Reg collectdlib[] = {
362 {"log_debug", lua_cb_log_debug},
363 {"log_error", lua_cb_log_error},
364 {"log_info", lua_cb_log_info},
365 {"log_notice", lua_cb_log_notice},
366 {"log_warning", lua_cb_log_warning},
367 {"dispatch_values", lua_cb_dispatch_values},
368 {"register_read", lua_cb_register_read},
369 {"register_write", lua_cb_register_write},
370 {NULL, NULL}
371 };
373 static int open_collectd(lua_State *L) /* {{{ */
374 {
375 #if LUA_VERSION_NUM < 502
376 luaL_register(L, "collectd", collectdlib);
377 #else
378 luaL_newlib(L, collectdlib);
379 #endif
380 return 1;
381 } /* }}} */
383 static void lua_script_free(lua_script_t *script) /* {{{ */
384 {
385 if (script == NULL)
386 return;
388 lua_script_t *next = script->next;
390 if (script->lua_state != NULL) {
391 lua_close(script->lua_state);
392 script->lua_state = NULL;
393 }
395 sfree(script->script_path);
396 sfree(script);
398 lua_script_free(next);
399 } /* }}} void lua_script_free */
401 static int lua_script_init(lua_script_t *script) /* {{{ */
402 {
403 memset(script, 0, sizeof(*script));
405 /* initialize the lua context */
406 script->lua_state = luaL_newstate();
407 if (script->lua_state == NULL) {
408 ERROR("Lua plugin: luaL_newstate() failed.");
409 return (-1);
410 }
412 /* Open up all the standard Lua libraries. */
413 luaL_openlibs(script->lua_state);
415 /* Load the 'collectd' library */
416 #if LUA_VERSION_NUM < 502
417 lua_pushcfunction(script->lua_state, open_collectd);
418 lua_pushstring(script->lua_state, "collectd");
419 lua_call(script->lua_state, 1, 0);
420 #else
421 luaL_requiref(script->lua_state, "collectd", open_collectd, 1);
422 lua_pop(script->lua_state, 1);
423 #endif
425 /* Prepend BasePath to package.path */
426 if (base_path[0] != '\0') {
427 lua_getglobal(script->lua_state, "package");
428 lua_getfield(script->lua_state, -1, "path");
430 const char *cur_path = lua_tostring(script->lua_state, -1);
431 char *new_path = ssnprintf_alloc("%s/?.lua;%s", base_path, cur_path);
433 lua_pop(script->lua_state, 1);
434 lua_pushstring(script->lua_state, new_path);
436 free(new_path);
438 lua_setfield(script->lua_state, -2, "path");
439 lua_pop(script->lua_state, 1);
440 }
442 return (0);
443 } /* }}} int lua_script_init */
445 static int lua_script_load(const char *script_path) /* {{{ */
446 {
447 lua_script_t *script = malloc(sizeof(*script));
448 if (script == NULL) {
449 ERROR("Lua plugin: malloc failed.");
450 return (-1);
451 }
453 int status = lua_script_init(script);
454 if (status != 0) {
455 lua_script_free(script);
456 return (status);
457 }
459 script->script_path = strdup(script_path);
460 if (script->script_path == NULL) {
461 ERROR("Lua plugin: strdup failed.");
462 lua_script_free(script);
463 return (-1);
464 }
466 status = luaL_loadfile(script->lua_state, script->script_path);
467 if (status != 0) {
468 ERROR("Lua plugin: luaL_loadfile failed: %s",
469 lua_tostring(script->lua_state, -1));
470 lua_pop(script->lua_state, 1);
471 lua_script_free(script);
472 return (-1);
473 }
475 status = lua_pcall(script->lua_state,
476 /* nargs = */ 0,
477 /* nresults = */ LUA_MULTRET,
478 /* errfunc = */ 0);
479 if (status != 0) {
480 const char *errmsg = lua_tostring(script->lua_state, -1);
482 if (errmsg == NULL)
483 ERROR("Lua plugin: lua_pcall failed with status %i. "
484 "In addition, no error message could be retrieved from the stack.",
485 status);
486 else
487 ERROR("Lua plugin: Executing script \"%s\" failed:\n%s",
488 script->script_path, errmsg);
490 lua_script_free(script);
491 return (-1);
492 }
494 /* Append this script to the global list of scripts. */
495 if (scripts) {
496 lua_script_t *last = scripts;
497 while (last->next)
498 last = last->next;
500 last->next = script;
501 } else {
502 scripts = script;
503 }
505 return (0);
506 } /* }}} int lua_script_load */
508 static int lua_config_base_path(const oconfig_item_t *ci) /* {{{ */
509 {
510 int status = cf_util_get_string_buffer(ci, base_path, sizeof(base_path));
511 if (status != 0)
512 return (status);
514 size_t len = strlen(base_path);
515 while ((len > 0) && (base_path[len - 1] == '/')) {
516 len--;
517 base_path[len] = '\0';
518 }
520 DEBUG("Lua plugin: base_path = \"%s\";", base_path);
522 return (0);
523 } /* }}} int lua_config_base_path */
525 static int lua_config_script(const oconfig_item_t *ci) /* {{{ */
526 {
527 char rel_path[PATH_MAX];
529 int status = cf_util_get_string_buffer(ci, rel_path, sizeof(rel_path));
530 if (status != 0)
531 return (status);
533 char abs_path[PATH_MAX];
535 if (base_path[0] == '\0')
536 sstrncpy(abs_path, rel_path, sizeof(abs_path));
537 else
538 ssnprintf(abs_path, sizeof(abs_path), "%s/%s", base_path, rel_path);
540 DEBUG("Lua plugin: abs_path = \"%s\";", abs_path);
542 status = lua_script_load(abs_path);
543 if (status != 0)
544 return (status);
546 INFO("Lua plugin: File \"%s\" loaded succesfully", abs_path);
548 return 0;
549 } /* }}} int lua_config_script */
551 /*
552 * <Plugin lua>
553 * BasePath "/"
554 * Script "script1.lua"
555 * Script "script2.lua"
556 * </Plugin>
557 */
558 static int lua_config(oconfig_item_t *ci) /* {{{ */
559 {
560 int status = 0;
561 for (int i = 0; i < ci->children_num; i++) {
562 oconfig_item_t *child = ci->children + i;
564 if (strcasecmp("BasePath", child->key) == 0) {
565 status = lua_config_base_path(child);
566 } else if (strcasecmp("Script", child->key) == 0) {
567 status = lua_config_script(child);
568 } else {
569 ERROR("Lua plugin: Option `%s' is not allowed here.", child->key);
570 status = 1;
571 }
572 }
574 return status;
575 } /* }}} int lua_config */
577 static int lua_shutdown(void) /* {{{ */
578 {
579 lua_script_free(scripts);
581 return (0);
582 } /* }}} int lua_shutdown */
584 void module_register(void) {
585 plugin_register_complex_config("lua", lua_config);
586 plugin_register_shutdown("lua", lua_shutdown);
587 }
589 /* vim: set sw=2 sts=2 et fdm=marker : */