1 /**
2 * collectd - src/unixsock.c
3 * Copyright (C) 2007,2008 Florian octo Forster
4 *
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.
8 *
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.
13 *
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
17 *
18 * Author:
19 * Florian octo Forster <octo at verplant.org>
20 **/
22 #include "collectd.h"
23 #include "common.h"
24 #include "plugin.h"
25 #include "configfile.h"
27 #include "utils_cmd_flush.h"
28 #include "utils_cmd_getval.h"
29 #include "utils_cmd_listval.h"
30 #include "utils_cmd_putval.h"
31 #include "utils_cmd_putnotif.h"
33 /* Folks without pthread will need to disable this plugin. */
34 #include <pthread.h>
36 #include <sys/socket.h>
37 #include <sys/stat.h>
38 #include <sys/un.h>
40 #include <grp.h>
42 #ifndef UNIX_PATH_MAX
43 # define UNIX_PATH_MAX sizeof (((struct sockaddr_un *)0)->sun_path)
44 #endif
46 #define US_DEFAULT_PATH LOCALSTATEDIR"/run/"PACKAGE_NAME"-unixsock"
48 /*
49 * Private variables
50 */
51 /* valid configuration file keys */
52 static const char *config_keys[] =
53 {
54 "SocketFile",
55 "SocketGroup",
56 "SocketPerms",
57 "DeleteSocket"
58 };
59 static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
61 static int loop = 0;
63 /* socket configuration */
64 static int sock_fd = -1;
65 static char *sock_file = NULL;
66 static char *sock_group = NULL;
67 static int sock_perms = S_IRWXU | S_IRWXG;
68 static _Bool delete_socket = 0;
70 static pthread_t listen_thread = (pthread_t) 0;
72 /*
73 * Functions
74 */
75 static int us_open_socket (void)
76 {
77 struct sockaddr_un sa;
78 int status;
80 sock_fd = socket (PF_UNIX, SOCK_STREAM, 0);
81 if (sock_fd < 0)
82 {
83 char errbuf[1024];
84 ERROR ("unixsock plugin: socket failed: %s",
85 sstrerror (errno, errbuf, sizeof (errbuf)));
86 return (-1);
87 }
89 memset (&sa, '\0', sizeof (sa));
90 sa.sun_family = AF_UNIX;
91 sstrncpy (sa.sun_path, (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
92 sizeof (sa.sun_path));
94 DEBUG ("unixsock plugin: socket path = %s", sa.sun_path);
96 if (delete_socket)
97 {
98 errno = 0;
99 status = unlink (sa.sun_path);
100 if ((status != 0) && (errno != ENOENT))
101 {
102 char errbuf[1024];
103 WARNING ("unixsock plugin: Deleting socket file \"%s\" failed: %s",
104 sa.sun_path,
105 sstrerror (errno, errbuf, sizeof (errbuf)));
106 }
107 else if (status == 0)
108 {
109 INFO ("unixsock plugin: Successfully deleted socket file \"%s\".",
110 sa.sun_path);
111 }
112 }
114 status = bind (sock_fd, (struct sockaddr *) &sa, sizeof (sa));
115 if (status != 0)
116 {
117 char errbuf[1024];
118 sstrerror (errno, errbuf, sizeof (errbuf));
119 ERROR ("unixsock plugin: bind failed: %s", errbuf);
120 close (sock_fd);
121 sock_fd = -1;
122 return (-1);
123 }
125 chmod (sa.sun_path, sock_perms);
127 status = listen (sock_fd, 8);
128 if (status != 0)
129 {
130 char errbuf[1024];
131 ERROR ("unixsock plugin: listen failed: %s",
132 sstrerror (errno, errbuf, sizeof (errbuf)));
133 close (sock_fd);
134 sock_fd = -1;
135 return (-1);
136 }
138 do
139 {
140 char *grpname;
141 struct group *g;
142 struct group sg;
143 char grbuf[2048];
145 grpname = (sock_group != NULL) ? sock_group : COLLECTD_GRP_NAME;
146 g = NULL;
148 status = getgrnam_r (grpname, &sg, grbuf, sizeof (grbuf), &g);
149 if (status != 0)
150 {
151 char errbuf[1024];
152 WARNING ("unixsock plugin: getgrnam_r (%s) failed: %s", grpname,
153 sstrerror (errno, errbuf, sizeof (errbuf)));
154 break;
155 }
156 if (g == NULL)
157 {
158 WARNING ("unixsock plugin: No such group: `%s'",
159 grpname);
160 break;
161 }
163 if (chown ((sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
164 (uid_t) -1, g->gr_gid) != 0)
165 {
166 char errbuf[1024];
167 WARNING ("unixsock plugin: chown (%s, -1, %i) failed: %s",
168 (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
169 (int) g->gr_gid,
170 sstrerror (errno, errbuf, sizeof (errbuf)));
171 }
172 } while (0);
174 return (0);
175 } /* int us_open_socket */
177 static void *us_handle_client (void *arg)
178 {
179 int fdin;
180 int fdout;
181 FILE *fhin, *fhout;
183 fdin = *((int *) arg);
184 free (arg);
185 arg = NULL;
187 DEBUG ("unixsock plugin: us_handle_client: Reading from fd #%i", fdin);
189 fdout = dup (fdin);
190 if (fdout < 0)
191 {
192 char errbuf[1024];
193 ERROR ("unixsock plugin: dup failed: %s",
194 sstrerror (errno, errbuf, sizeof (errbuf)));
195 close (fdin);
196 pthread_exit ((void *) 1);
197 }
199 fhin = fdopen (fdin, "r");
200 if (fhin == NULL)
201 {
202 char errbuf[1024];
203 ERROR ("unixsock plugin: fdopen failed: %s",
204 sstrerror (errno, errbuf, sizeof (errbuf)));
205 close (fdin);
206 close (fdout);
207 pthread_exit ((void *) 1);
208 }
210 fhout = fdopen (fdout, "w");
211 if (fhout == NULL)
212 {
213 char errbuf[1024];
214 ERROR ("unixsock plugin: fdopen failed: %s",
215 sstrerror (errno, errbuf, sizeof (errbuf)));
216 fclose (fhin); /* this closes fdin as well */
217 close (fdout);
218 pthread_exit ((void *) 1);
219 }
221 /* change output buffer to line buffered mode */
222 if (setvbuf (fhout, NULL, _IOLBF, 0) != 0)
223 {
224 char errbuf[1024];
225 ERROR ("unixsock plugin: setvbuf failed: %s",
226 sstrerror (errno, errbuf, sizeof (errbuf)));
227 fclose (fhin);
228 fclose (fhout);
229 pthread_exit ((void *) 1);
230 }
232 while (42)
233 {
234 char buffer[1024];
235 char buffer_copy[1024];
236 char *fields[128];
237 int fields_num;
238 int len;
240 errno = 0;
241 if (fgets (buffer, sizeof (buffer), fhin) == NULL)
242 {
243 if (errno != 0)
244 {
245 char errbuf[1024];
246 WARNING ("unixsock plugin: failed to read from socket #%i: %s",
247 fileno (fhin),
248 sstrerror (errno, errbuf, sizeof (errbuf)));
249 }
250 break;
251 }
253 len = strlen (buffer);
254 while ((len > 0)
255 && ((buffer[len - 1] == '\n') || (buffer[len - 1] == '\r')))
256 buffer[--len] = '\0';
258 if (len == 0)
259 continue;
261 sstrncpy (buffer_copy, buffer, sizeof (buffer_copy));
263 fields_num = strsplit (buffer_copy, fields,
264 sizeof (fields) / sizeof (fields[0]));
265 if (fields_num < 1)
266 {
267 fprintf (fhout, "-1 Internal error\n");
268 fclose (fhin);
269 fclose (fhout);
270 pthread_exit ((void *) 1);
271 }
273 if (strcasecmp (fields[0], "getval") == 0)
274 {
275 handle_getval (fhout, buffer);
276 }
277 else if (strcasecmp (fields[0], "putval") == 0)
278 {
279 handle_putval (fhout, buffer);
280 }
281 else if (strcasecmp (fields[0], "listval") == 0)
282 {
283 handle_listval (fhout, buffer);
284 }
285 else if (strcasecmp (fields[0], "putnotif") == 0)
286 {
287 handle_putnotif (fhout, buffer);
288 }
289 else if (strcasecmp (fields[0], "flush") == 0)
290 {
291 handle_flush (fhout, buffer);
292 }
293 else
294 {
295 if (fprintf (fhout, "-1 Unknown command: %s\n", fields[0]) < 0)
296 {
297 char errbuf[1024];
298 WARNING ("unixsock plugin: failed to write to socket #%i: %s",
299 fileno (fhout),
300 sstrerror (errno, errbuf, sizeof (errbuf)));
301 break;
302 }
303 }
304 } /* while (fgets) */
306 DEBUG ("unixsock plugin: us_handle_client: Exiting..");
307 fclose (fhin);
308 fclose (fhout);
310 pthread_exit ((void *) 0);
311 return ((void *) 0);
312 } /* void *us_handle_client */
314 static void *us_server_thread (void __attribute__((unused)) *arg)
315 {
316 int status;
317 int *remote_fd;
318 pthread_t th;
319 pthread_attr_t th_attr;
321 if (us_open_socket () != 0)
322 pthread_exit ((void *) 1);
324 while (loop != 0)
325 {
326 DEBUG ("unixsock plugin: Calling accept..");
327 status = accept (sock_fd, NULL, NULL);
328 if (status < 0)
329 {
330 char errbuf[1024];
332 if (errno == EINTR)
333 continue;
335 ERROR ("unixsock plugin: accept failed: %s",
336 sstrerror (errno, errbuf, sizeof (errbuf)));
337 close (sock_fd);
338 sock_fd = -1;
339 pthread_exit ((void *) 1);
340 }
342 remote_fd = (int *) malloc (sizeof (int));
343 if (remote_fd == NULL)
344 {
345 char errbuf[1024];
346 WARNING ("unixsock plugin: malloc failed: %s",
347 sstrerror (errno, errbuf, sizeof (errbuf)));
348 close (status);
349 continue;
350 }
351 *remote_fd = status;
353 DEBUG ("Spawning child to handle connection on fd #%i", *remote_fd);
355 pthread_attr_init (&th_attr);
356 pthread_attr_setdetachstate (&th_attr, PTHREAD_CREATE_DETACHED);
358 status = pthread_create (&th, &th_attr, us_handle_client, (void *) remote_fd);
359 if (status != 0)
360 {
361 char errbuf[1024];
362 WARNING ("unixsock plugin: pthread_create failed: %s",
363 sstrerror (errno, errbuf, sizeof (errbuf)));
364 close (*remote_fd);
365 free (remote_fd);
366 continue;
367 }
368 } /* while (loop) */
370 close (sock_fd);
371 sock_fd = -1;
373 status = unlink ((sock_file != NULL) ? sock_file : US_DEFAULT_PATH);
374 if (status != 0)
375 {
376 char errbuf[1024];
377 NOTICE ("unixsock plugin: unlink (%s) failed: %s",
378 (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
379 sstrerror (errno, errbuf, sizeof (errbuf)));
380 }
382 return ((void *) 0);
383 } /* void *us_server_thread */
385 static int us_config (const char *key, const char *val)
386 {
387 if (strcasecmp (key, "SocketFile") == 0)
388 {
389 char *new_sock_file = strdup (val);
390 if (new_sock_file == NULL)
391 return (1);
393 sfree (sock_file);
394 sock_file = new_sock_file;
395 }
396 else if (strcasecmp (key, "SocketGroup") == 0)
397 {
398 char *new_sock_group = strdup (val);
399 if (new_sock_group == NULL)
400 return (1);
402 sfree (sock_group);
403 sock_group = new_sock_group;
404 }
405 else if (strcasecmp (key, "SocketPerms") == 0)
406 {
407 sock_perms = (int) strtol (val, NULL, 8);
408 }
409 else if (strcasecmp (key, "DeleteSocket") == 0)
410 {
411 if (IS_TRUE (val))
412 delete_socket = 1;
413 else
414 delete_socket = 0;
415 }
416 else
417 {
418 return (-1);
419 }
421 return (0);
422 } /* int us_config */
424 static int us_init (void)
425 {
426 static int have_init = 0;
428 int status;
430 /* Initialize only once. */
431 if (have_init != 0)
432 return (0);
433 have_init = 1;
435 loop = 1;
437 status = pthread_create (&listen_thread, NULL, us_server_thread, NULL);
438 if (status != 0)
439 {
440 char errbuf[1024];
441 ERROR ("unixsock plugin: pthread_create failed: %s",
442 sstrerror (errno, errbuf, sizeof (errbuf)));
443 return (-1);
444 }
446 return (0);
447 } /* int us_init */
449 static int us_shutdown (void)
450 {
451 void *ret;
453 loop = 0;
455 if (listen_thread != (pthread_t) 0)
456 {
457 pthread_kill (listen_thread, SIGTERM);
458 pthread_join (listen_thread, &ret);
459 listen_thread = (pthread_t) 0;
460 }
462 plugin_unregister_init ("unixsock");
463 plugin_unregister_shutdown ("unixsock");
465 return (0);
466 } /* int us_shutdown */
468 void module_register (void)
469 {
470 plugin_register_config ("unixsock", us_config,
471 config_keys, config_keys_num);
472 plugin_register_init ("unixsock", us_init);
473 plugin_register_shutdown ("unixsock", us_shutdown);
474 } /* void module_register (void) */
476 /* vim: set sw=4 ts=4 sts=4 tw=78 : */