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/socket.h>
43 #include <sys/stat.h>
44 #include <sys/un.h>
46 #include <grp.h>
48 #ifndef UNIX_PATH_MAX
49 # define UNIX_PATH_MAX sizeof (((struct sockaddr_un *)0)->sun_path)
50 #endif
52 #define US_DEFAULT_PATH LOCALSTATEDIR"/run/"PACKAGE_NAME"-unixsock"
54 /*
55 * Private variables
56 */
57 /* valid configuration file keys */
58 static const char *config_keys[] =
59 {
60 "SocketFile",
61 "SocketGroup",
62 "SocketPerms",
63 "DeleteSocket"
64 };
65 static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
67 static int loop = 0;
69 /* socket configuration */
70 static int sock_fd = -1;
71 static char *sock_file = NULL;
72 static char *sock_group = NULL;
73 static int sock_perms = S_IRWXU | S_IRWXG;
74 static _Bool delete_socket = 0;
76 static pthread_t listen_thread = (pthread_t) 0;
78 /*
79 * Functions
80 */
81 static int us_open_socket (void)
82 {
83 struct sockaddr_un sa;
84 int status;
86 sock_fd = socket (PF_UNIX, SOCK_STREAM, 0);
87 if (sock_fd < 0)
88 {
89 char errbuf[1024];
90 ERROR ("unixsock plugin: socket failed: %s",
91 sstrerror (errno, errbuf, sizeof (errbuf)));
92 return (-1);
93 }
95 memset (&sa, '\0', sizeof (sa));
96 sa.sun_family = AF_UNIX;
97 sstrncpy (sa.sun_path, (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
98 sizeof (sa.sun_path));
100 DEBUG ("unixsock plugin: socket path = %s", sa.sun_path);
102 if (delete_socket)
103 {
104 errno = 0;
105 status = unlink (sa.sun_path);
106 if ((status != 0) && (errno != ENOENT))
107 {
108 char errbuf[1024];
109 WARNING ("unixsock plugin: Deleting socket file \"%s\" failed: %s",
110 sa.sun_path,
111 sstrerror (errno, errbuf, sizeof (errbuf)));
112 }
113 else if (status == 0)
114 {
115 INFO ("unixsock plugin: Successfully deleted socket file \"%s\".",
116 sa.sun_path);
117 }
118 }
120 status = bind (sock_fd, (struct sockaddr *) &sa, sizeof (sa));
121 if (status != 0)
122 {
123 char errbuf[1024];
124 sstrerror (errno, errbuf, sizeof (errbuf));
125 ERROR ("unixsock plugin: bind failed: %s", errbuf);
126 close (sock_fd);
127 sock_fd = -1;
128 return (-1);
129 }
131 status = chmod (sa.sun_path, sock_perms);
132 if (status == -1)
133 {
134 char errbuf[1024];
135 ERROR ("unixsock plugin: chmod failed: %s",
136 sstrerror (errno, errbuf, sizeof (errbuf)));
137 close (sock_fd);
138 sock_fd = -1;
139 return (-1);
140 }
142 status = listen (sock_fd, 8);
143 if (status != 0)
144 {
145 char errbuf[1024];
146 ERROR ("unixsock plugin: listen failed: %s",
147 sstrerror (errno, errbuf, sizeof (errbuf)));
148 close (sock_fd);
149 sock_fd = -1;
150 return (-1);
151 }
153 do
154 {
155 char *grpname;
156 struct group *g;
157 struct group sg;
158 char grbuf[2048];
160 grpname = (sock_group != NULL) ? sock_group : COLLECTD_GRP_NAME;
161 g = NULL;
163 status = getgrnam_r (grpname, &sg, grbuf, sizeof (grbuf), &g);
164 if (status != 0)
165 {
166 char errbuf[1024];
167 WARNING ("unixsock plugin: getgrnam_r (%s) failed: %s", grpname,
168 sstrerror (errno, errbuf, sizeof (errbuf)));
169 break;
170 }
171 if (g == NULL)
172 {
173 WARNING ("unixsock plugin: No such group: `%s'",
174 grpname);
175 break;
176 }
178 if (chown ((sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
179 (uid_t) -1, g->gr_gid) != 0)
180 {
181 char errbuf[1024];
182 WARNING ("unixsock plugin: chown (%s, -1, %i) failed: %s",
183 (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
184 (int) g->gr_gid,
185 sstrerror (errno, errbuf, sizeof (errbuf)));
186 }
187 } while (0);
189 return (0);
190 } /* int us_open_socket */
192 static void *us_handle_client (void *arg)
193 {
194 int fdin;
195 int fdout;
196 FILE *fhin, *fhout;
198 fdin = *((int *) arg);
199 free (arg);
200 arg = NULL;
202 DEBUG ("unixsock plugin: us_handle_client: Reading from fd #%i", fdin);
204 fdout = dup (fdin);
205 if (fdout < 0)
206 {
207 char errbuf[1024];
208 ERROR ("unixsock plugin: dup failed: %s",
209 sstrerror (errno, errbuf, sizeof (errbuf)));
210 close (fdin);
211 pthread_exit ((void *) 1);
212 }
214 fhin = fdopen (fdin, "r");
215 if (fhin == NULL)
216 {
217 char errbuf[1024];
218 ERROR ("unixsock plugin: fdopen failed: %s",
219 sstrerror (errno, errbuf, sizeof (errbuf)));
220 close (fdin);
221 close (fdout);
222 pthread_exit ((void *) 1);
223 return ((void *) 1);
224 }
226 fhout = fdopen (fdout, "w");
227 if (fhout == NULL)
228 {
229 char errbuf[1024];
230 ERROR ("unixsock plugin: fdopen failed: %s",
231 sstrerror (errno, errbuf, sizeof (errbuf)));
232 fclose (fhin); /* this closes fdin as well */
233 close (fdout);
234 pthread_exit ((void *) 1);
235 return ((void *) 1);
236 }
238 /* change output buffer to line buffered mode */
239 if (setvbuf (fhout, NULL, _IOLBF, 0) != 0)
240 {
241 char errbuf[1024];
242 ERROR ("unixsock plugin: setvbuf failed: %s",
243 sstrerror (errno, errbuf, sizeof (errbuf)));
244 fclose (fhin);
245 fclose (fhout);
246 pthread_exit ((void *) 1);
247 return ((void *) 0);
248 }
250 while (42)
251 {
252 char buffer[1024];
253 char buffer_copy[1024];
254 char *fields[128];
255 int fields_num;
256 int len;
258 errno = 0;
259 if (fgets (buffer, sizeof (buffer), fhin) == NULL)
260 {
261 if ((errno == EINTR) || (errno == EAGAIN))
262 continue;
264 if (errno != 0)
265 {
266 char errbuf[1024];
267 WARNING ("unixsock plugin: failed to read from socket #%i: %s",
268 fileno (fhin),
269 sstrerror (errno, errbuf, sizeof (errbuf)));
270 }
271 break;
272 }
274 len = strlen (buffer);
275 while ((len > 0)
276 && ((buffer[len - 1] == '\n') || (buffer[len - 1] == '\r')))
277 buffer[--len] = '\0';
279 if (len == 0)
280 continue;
282 sstrncpy (buffer_copy, buffer, sizeof (buffer_copy));
284 fields_num = strsplit (buffer_copy, fields,
285 sizeof (fields) / sizeof (fields[0]));
286 if (fields_num < 1)
287 {
288 fprintf (fhout, "-1 Internal error\n");
289 fclose (fhin);
290 fclose (fhout);
291 pthread_exit ((void *) 1);
292 return ((void *) 1);
293 }
295 if (strcasecmp (fields[0], "getval") == 0)
296 {
297 handle_getval (fhout, buffer);
298 }
299 else if (strcasecmp (fields[0], "getthreshold") == 0)
300 {
301 handle_getthreshold (fhout, buffer);
302 }
303 else if (strcasecmp (fields[0], "putval") == 0)
304 {
305 handle_putval (fhout, buffer);
306 }
307 else if (strcasecmp (fields[0], "listval") == 0)
308 {
309 handle_listval (fhout, buffer);
310 }
311 else if (strcasecmp (fields[0], "putnotif") == 0)
312 {
313 handle_putnotif (fhout, buffer);
314 }
315 else if (strcasecmp (fields[0], "flush") == 0)
316 {
317 handle_flush (fhout, buffer);
318 }
319 else
320 {
321 if (fprintf (fhout, "-1 Unknown command: %s\n", fields[0]) < 0)
322 {
323 char errbuf[1024];
324 WARNING ("unixsock plugin: failed to write to socket #%i: %s",
325 fileno (fhout),
326 sstrerror (errno, errbuf, sizeof (errbuf)));
327 break;
328 }
329 }
330 } /* while (fgets) */
332 DEBUG ("unixsock plugin: us_handle_client: Exiting..");
333 fclose (fhin);
334 fclose (fhout);
336 pthread_exit ((void *) 0);
337 return ((void *) 0);
338 } /* void *us_handle_client */
340 static void *us_server_thread (void __attribute__((unused)) *arg)
341 {
342 int status;
343 int *remote_fd;
344 pthread_t th;
345 pthread_attr_t th_attr;
347 pthread_attr_init (&th_attr);
348 pthread_attr_setdetachstate (&th_attr, PTHREAD_CREATE_DETACHED);
350 if (us_open_socket () != 0)
351 pthread_exit ((void *) 1);
353 while (loop != 0)
354 {
355 DEBUG ("unixsock plugin: Calling accept..");
356 status = accept (sock_fd, NULL, NULL);
357 if (status < 0)
358 {
359 char errbuf[1024];
361 if (errno == EINTR)
362 continue;
364 ERROR ("unixsock plugin: accept failed: %s",
365 sstrerror (errno, errbuf, sizeof (errbuf)));
366 close (sock_fd);
367 sock_fd = -1;
368 pthread_attr_destroy (&th_attr);
369 pthread_exit ((void *) 1);
370 }
372 remote_fd = (int *) malloc (sizeof (int));
373 if (remote_fd == NULL)
374 {
375 char errbuf[1024];
376 WARNING ("unixsock plugin: malloc failed: %s",
377 sstrerror (errno, errbuf, sizeof (errbuf)));
378 close (status);
379 continue;
380 }
381 *remote_fd = status;
383 DEBUG ("Spawning child to handle connection on fd #%i", *remote_fd);
385 status = plugin_thread_create (&th, &th_attr,
386 us_handle_client, (void *) remote_fd);
387 if (status != 0)
388 {
389 char errbuf[1024];
390 WARNING ("unixsock plugin: pthread_create failed: %s",
391 sstrerror (errno, errbuf, sizeof (errbuf)));
392 close (*remote_fd);
393 free (remote_fd);
394 continue;
395 }
396 } /* while (loop) */
398 close (sock_fd);
399 sock_fd = -1;
400 pthread_attr_destroy (&th_attr);
402 status = unlink ((sock_file != NULL) ? sock_file : US_DEFAULT_PATH);
403 if (status != 0)
404 {
405 char errbuf[1024];
406 NOTICE ("unixsock plugin: unlink (%s) failed: %s",
407 (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
408 sstrerror (errno, errbuf, sizeof (errbuf)));
409 }
411 return ((void *) 0);
412 } /* void *us_server_thread */
414 static int us_config (const char *key, const char *val)
415 {
416 if (strcasecmp (key, "SocketFile") == 0)
417 {
418 char *new_sock_file = strdup (val);
419 if (new_sock_file == NULL)
420 return (1);
422 sfree (sock_file);
423 sock_file = new_sock_file;
424 }
425 else if (strcasecmp (key, "SocketGroup") == 0)
426 {
427 char *new_sock_group = strdup (val);
428 if (new_sock_group == NULL)
429 return (1);
431 sfree (sock_group);
432 sock_group = new_sock_group;
433 }
434 else if (strcasecmp (key, "SocketPerms") == 0)
435 {
436 sock_perms = (int) strtol (val, NULL, 8);
437 }
438 else if (strcasecmp (key, "DeleteSocket") == 0)
439 {
440 if (IS_TRUE (val))
441 delete_socket = 1;
442 else
443 delete_socket = 0;
444 }
445 else
446 {
447 return (-1);
448 }
450 return (0);
451 } /* int us_config */
453 static int us_init (void)
454 {
455 static int have_init = 0;
457 int status;
459 /* Initialize only once. */
460 if (have_init != 0)
461 return (0);
462 have_init = 1;
464 loop = 1;
466 status = plugin_thread_create (&listen_thread, NULL,
467 us_server_thread, NULL);
468 if (status != 0)
469 {
470 char errbuf[1024];
471 ERROR ("unixsock plugin: pthread_create failed: %s",
472 sstrerror (errno, errbuf, sizeof (errbuf)));
473 return (-1);
474 }
476 return (0);
477 } /* int us_init */
479 static int us_shutdown (void)
480 {
481 void *ret;
483 loop = 0;
485 if (listen_thread != (pthread_t) 0)
486 {
487 pthread_kill (listen_thread, SIGTERM);
488 pthread_join (listen_thread, &ret);
489 listen_thread = (pthread_t) 0;
490 }
492 plugin_unregister_init ("unixsock");
493 plugin_unregister_shutdown ("unixsock");
495 return (0);
496 } /* int us_shutdown */
498 void module_register (void)
499 {
500 plugin_register_config ("unixsock", us_config,
501 config_keys, config_keys_num);
502 plugin_register_init ("unixsock", us_init);
503 plugin_register_shutdown ("unixsock", us_shutdown);
504 } /* void module_register (void) */
506 /* vim: set sw=4 ts=4 sts=4 tw=78 : */