1 /**
2 * collectd - src/unixsock.c
3 * Copyright (C) 2007,2008 Florian octo Forster
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 *
23 * Authors:
24 * Florian octo Forster <octo at collectd.org>
25 **/
27 #include "collectd.h"
28 #include "common.h"
29 #include "plugin.h"
30 #include "configfile.h"
32 #include "utils_cmd_flush.h"
33 #include "utils_cmd_getval.h"
34 #include "utils_cmd_getthreshold.h"
35 #include "utils_cmd_listval.h"
36 #include "utils_cmd_putval.h"
37 #include "utils_cmd_putnotif.h"
39 /* Folks without pthread will need to disable this plugin. */
40 #include <pthread.h>
42 #include <sys/stat.h>
43 #include <sys/un.h>
45 #include <grp.h>
47 #ifndef UNIX_PATH_MAX
48 # define UNIX_PATH_MAX sizeof (((struct sockaddr_un *)0)->sun_path)
49 #endif
51 #define US_DEFAULT_PATH LOCALSTATEDIR"/run/"PACKAGE_NAME"-unixsock"
53 /*
54 * Private variables
55 */
56 /* valid configuration file keys */
57 static const char *config_keys[] =
58 {
59 "SocketFile",
60 "SocketGroup",
61 "SocketPerms",
62 "DeleteSocket"
63 };
64 static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
66 static int loop = 0;
68 /* socket configuration */
69 static int sock_fd = -1;
70 static char *sock_file = NULL;
71 static char *sock_group = NULL;
72 static int sock_perms = S_IRWXU | S_IRWXG;
73 static _Bool delete_socket = 0;
75 static pthread_t listen_thread = (pthread_t) 0;
77 /*
78 * Functions
79 */
80 static int us_open_socket (void)
81 {
82 struct sockaddr_un sa;
83 int status;
85 sock_fd = socket (PF_UNIX, SOCK_STREAM, 0);
86 if (sock_fd < 0)
87 {
88 char errbuf[1024];
89 ERROR ("unixsock plugin: socket failed: %s",
90 sstrerror (errno, errbuf, sizeof (errbuf)));
91 return (-1);
92 }
94 memset (&sa, '\0', sizeof (sa));
95 sa.sun_family = AF_UNIX;
96 sstrncpy (sa.sun_path, (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
97 sizeof (sa.sun_path));
99 DEBUG ("unixsock plugin: socket path = %s", sa.sun_path);
101 if (delete_socket)
102 {
103 errno = 0;
104 status = unlink (sa.sun_path);
105 if ((status != 0) && (errno != ENOENT))
106 {
107 char errbuf[1024];
108 WARNING ("unixsock plugin: Deleting socket file \"%s\" failed: %s",
109 sa.sun_path,
110 sstrerror (errno, errbuf, sizeof (errbuf)));
111 }
112 else if (status == 0)
113 {
114 INFO ("unixsock plugin: Successfully deleted socket file \"%s\".",
115 sa.sun_path);
116 }
117 }
119 status = bind (sock_fd, (struct sockaddr *) &sa, sizeof (sa));
120 if (status != 0)
121 {
122 char errbuf[1024];
123 sstrerror (errno, errbuf, sizeof (errbuf));
124 ERROR ("unixsock plugin: bind failed: %s", errbuf);
125 close (sock_fd);
126 sock_fd = -1;
127 return (-1);
128 }
130 chmod (sa.sun_path, sock_perms);
132 status = listen (sock_fd, 8);
133 if (status != 0)
134 {
135 char errbuf[1024];
136 ERROR ("unixsock plugin: listen failed: %s",
137 sstrerror (errno, errbuf, sizeof (errbuf)));
138 close (sock_fd);
139 sock_fd = -1;
140 return (-1);
141 }
143 do
144 {
145 char *grpname;
146 struct group *g;
147 struct group sg;
148 char grbuf[2048];
150 grpname = (sock_group != NULL) ? sock_group : COLLECTD_GRP_NAME;
151 g = NULL;
153 status = getgrnam_r (grpname, &sg, grbuf, sizeof (grbuf), &g);
154 if (status != 0)
155 {
156 char errbuf[1024];
157 WARNING ("unixsock plugin: getgrnam_r (%s) failed: %s", grpname,
158 sstrerror (errno, errbuf, sizeof (errbuf)));
159 break;
160 }
161 if (g == NULL)
162 {
163 WARNING ("unixsock plugin: No such group: `%s'",
164 grpname);
165 break;
166 }
168 if (chown ((sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
169 (uid_t) -1, g->gr_gid) != 0)
170 {
171 char errbuf[1024];
172 WARNING ("unixsock plugin: chown (%s, -1, %i) failed: %s",
173 (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
174 (int) g->gr_gid,
175 sstrerror (errno, errbuf, sizeof (errbuf)));
176 }
177 } while (0);
179 return (0);
180 } /* int us_open_socket */
182 static void *us_handle_client (void *arg)
183 {
184 int fdin;
185 int fdout;
186 FILE *fhin, *fhout;
188 fdin = *((int *) arg);
189 free (arg);
190 arg = NULL;
192 DEBUG ("unixsock plugin: us_handle_client: Reading from fd #%i", fdin);
194 fdout = dup (fdin);
195 if (fdout < 0)
196 {
197 char errbuf[1024];
198 ERROR ("unixsock plugin: dup failed: %s",
199 sstrerror (errno, errbuf, sizeof (errbuf)));
200 close (fdin);
201 pthread_exit ((void *) 1);
202 }
204 fhin = fdopen (fdin, "r");
205 if (fhin == NULL)
206 {
207 char errbuf[1024];
208 ERROR ("unixsock plugin: fdopen failed: %s",
209 sstrerror (errno, errbuf, sizeof (errbuf)));
210 close (fdin);
211 close (fdout);
212 pthread_exit ((void *) 1);
213 return ((void *) 1);
214 }
216 fhout = fdopen (fdout, "w");
217 if (fhout == NULL)
218 {
219 char errbuf[1024];
220 ERROR ("unixsock plugin: fdopen failed: %s",
221 sstrerror (errno, errbuf, sizeof (errbuf)));
222 fclose (fhin); /* this closes fdin as well */
223 close (fdout);
224 pthread_exit ((void *) 1);
225 return ((void *) 1);
226 }
228 /* change output buffer to line buffered mode */
229 if (setvbuf (fhout, NULL, _IOLBF, 0) != 0)
230 {
231 char errbuf[1024];
232 ERROR ("unixsock plugin: setvbuf failed: %s",
233 sstrerror (errno, errbuf, sizeof (errbuf)));
234 fclose (fhin);
235 fclose (fhout);
236 pthread_exit ((void *) 1);
237 return ((void *) 0);
238 }
240 while (42)
241 {
242 char buffer[1024];
243 char buffer_copy[1024];
244 char *fields[128];
245 int fields_num;
246 int len;
248 errno = 0;
249 if (fgets (buffer, sizeof (buffer), fhin) == NULL)
250 {
251 if ((errno == EINTR) || (errno == EAGAIN))
252 continue;
254 if (errno != 0)
255 {
256 char errbuf[1024];
257 WARNING ("unixsock plugin: failed to read from socket #%i: %s",
258 fileno (fhin),
259 sstrerror (errno, errbuf, sizeof (errbuf)));
260 }
261 break;
262 }
264 len = strlen (buffer);
265 while ((len > 0)
266 && ((buffer[len - 1] == '\n') || (buffer[len - 1] == '\r')))
267 buffer[--len] = '\0';
269 if (len == 0)
270 continue;
272 sstrncpy (buffer_copy, buffer, sizeof (buffer_copy));
274 fields_num = strsplit (buffer_copy, fields,
275 sizeof (fields) / sizeof (fields[0]));
276 if (fields_num < 1)
277 {
278 fprintf (fhout, "-1 Internal error\n");
279 fclose (fhin);
280 fclose (fhout);
281 pthread_exit ((void *) 1);
282 return ((void *) 1);
283 }
285 if (strcasecmp (fields[0], "getval") == 0)
286 {
287 handle_getval (fhout, buffer);
288 }
289 else if (strcasecmp (fields[0], "getthreshold") == 0)
290 {
291 handle_getthreshold (fhout, buffer);
292 }
293 else if (strcasecmp (fields[0], "putval") == 0)
294 {
295 handle_putval (fhout, buffer);
296 }
297 else if (strcasecmp (fields[0], "listval") == 0)
298 {
299 handle_listval (fhout, buffer);
300 }
301 else if (strcasecmp (fields[0], "putnotif") == 0)
302 {
303 handle_putnotif (fhout, buffer);
304 }
305 else if (strcasecmp (fields[0], "flush") == 0)
306 {
307 handle_flush (fhout, buffer);
308 }
309 else
310 {
311 if (fprintf (fhout, "-1 Unknown command: %s\n", fields[0]) < 0)
312 {
313 char errbuf[1024];
314 WARNING ("unixsock plugin: failed to write to socket #%i: %s",
315 fileno (fhout),
316 sstrerror (errno, errbuf, sizeof (errbuf)));
317 break;
318 }
319 }
320 } /* while (fgets) */
322 DEBUG ("unixsock plugin: us_handle_client: Exiting..");
323 fclose (fhin);
324 fclose (fhout);
326 pthread_exit ((void *) 0);
327 return ((void *) 0);
328 } /* void *us_handle_client */
330 static void *us_server_thread (void __attribute__((unused)) *arg)
331 {
332 int status;
333 int *remote_fd;
334 pthread_t th;
335 pthread_attr_t th_attr;
337 pthread_attr_init (&th_attr);
338 pthread_attr_setdetachstate (&th_attr, PTHREAD_CREATE_DETACHED);
340 if (us_open_socket () != 0)
341 pthread_exit ((void *) 1);
343 while (loop != 0)
344 {
345 DEBUG ("unixsock plugin: Calling accept..");
346 status = accept (sock_fd, NULL, NULL);
347 if (status < 0)
348 {
349 char errbuf[1024];
351 if (errno == EINTR)
352 continue;
354 ERROR ("unixsock plugin: accept failed: %s",
355 sstrerror (errno, errbuf, sizeof (errbuf)));
356 close (sock_fd);
357 sock_fd = -1;
358 pthread_attr_destroy (&th_attr);
359 pthread_exit ((void *) 1);
360 }
362 remote_fd = (int *) malloc (sizeof (int));
363 if (remote_fd == NULL)
364 {
365 char errbuf[1024];
366 WARNING ("unixsock plugin: malloc failed: %s",
367 sstrerror (errno, errbuf, sizeof (errbuf)));
368 close (status);
369 continue;
370 }
371 *remote_fd = status;
373 DEBUG ("Spawning child to handle connection on fd #%i", *remote_fd);
375 status = plugin_thread_create (&th, &th_attr,
376 us_handle_client, (void *) remote_fd);
377 if (status != 0)
378 {
379 char errbuf[1024];
380 WARNING ("unixsock plugin: pthread_create failed: %s",
381 sstrerror (errno, errbuf, sizeof (errbuf)));
382 close (*remote_fd);
383 free (remote_fd);
384 continue;
385 }
386 } /* while (loop) */
388 close (sock_fd);
389 sock_fd = -1;
390 pthread_attr_destroy (&th_attr);
392 status = unlink ((sock_file != NULL) ? sock_file : US_DEFAULT_PATH);
393 if (status != 0)
394 {
395 char errbuf[1024];
396 NOTICE ("unixsock plugin: unlink (%s) failed: %s",
397 (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
398 sstrerror (errno, errbuf, sizeof (errbuf)));
399 }
401 return ((void *) 0);
402 } /* void *us_server_thread */
404 static int us_config (const char *key, const char *val)
405 {
406 if (strcasecmp (key, "SocketFile") == 0)
407 {
408 char *new_sock_file = strdup (val);
409 if (new_sock_file == NULL)
410 return (1);
412 sfree (sock_file);
413 sock_file = new_sock_file;
414 }
415 else if (strcasecmp (key, "SocketGroup") == 0)
416 {
417 char *new_sock_group = strdup (val);
418 if (new_sock_group == NULL)
419 return (1);
421 sfree (sock_group);
422 sock_group = new_sock_group;
423 }
424 else if (strcasecmp (key, "SocketPerms") == 0)
425 {
426 sock_perms = (int) strtol (val, NULL, 8);
427 }
428 else if (strcasecmp (key, "DeleteSocket") == 0)
429 {
430 if (IS_TRUE (val))
431 delete_socket = 1;
432 else
433 delete_socket = 0;
434 }
435 else
436 {
437 return (-1);
438 }
440 return (0);
441 } /* int us_config */
443 static int us_init (void)
444 {
445 static int have_init = 0;
447 int status;
449 /* Initialize only once. */
450 if (have_init != 0)
451 return (0);
452 have_init = 1;
454 loop = 1;
456 status = plugin_thread_create (&listen_thread, NULL,
457 us_server_thread, NULL);
458 if (status != 0)
459 {
460 char errbuf[1024];
461 ERROR ("unixsock plugin: pthread_create failed: %s",
462 sstrerror (errno, errbuf, sizeof (errbuf)));
463 return (-1);
464 }
466 return (0);
467 } /* int us_init */
469 static int us_shutdown (void)
470 {
471 void *ret;
473 loop = 0;
475 if (listen_thread != (pthread_t) 0)
476 {
477 pthread_kill (listen_thread, SIGTERM);
478 pthread_join (listen_thread, &ret);
479 listen_thread = (pthread_t) 0;
480 }
482 plugin_unregister_init ("unixsock");
483 plugin_unregister_shutdown ("unixsock");
485 return (0);
486 } /* int us_shutdown */
488 void module_register (void)
489 {
490 plugin_register_config ("unixsock", us_config,
491 config_keys, config_keys_num);
492 plugin_register_init ("unixsock", us_init);
493 plugin_register_shutdown ("unixsock", us_shutdown);
494 } /* void module_register (void) */
496 /* vim: set sw=4 ts=4 sts=4 tw=78 : */