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_getthreshold.h"
30 #include "utils_cmd_listval.h"
31 #include "utils_cmd_putval.h"
32 #include "utils_cmd_putnotif.h"
34 /* Folks without pthread will need to disable this plugin. */
35 #include <pthread.h>
37 #include <sys/socket.h>
38 #include <sys/stat.h>
39 #include <sys/un.h>
41 #include <grp.h>
43 #ifndef UNIX_PATH_MAX
44 # define UNIX_PATH_MAX sizeof (((struct sockaddr_un *)0)->sun_path)
45 #endif
47 #define US_DEFAULT_PATH LOCALSTATEDIR"/run/"PACKAGE_NAME"-unixsock"
49 /*
50 * Private variables
51 */
52 /* valid configuration file keys */
53 static const char *config_keys[] =
54 {
55 "SocketFile",
56 "SocketGroup",
57 "SocketPerms"
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;
69 static pthread_t listen_thread = (pthread_t) 0;
71 /*
72 * Functions
73 */
74 static int us_open_socket (void)
75 {
76 struct sockaddr_un sa;
77 int status;
79 sock_fd = socket (PF_UNIX, SOCK_STREAM, 0);
80 if (sock_fd < 0)
81 {
82 char errbuf[1024];
83 ERROR ("unixsock plugin: socket failed: %s",
84 sstrerror (errno, errbuf, sizeof (errbuf)));
85 return (-1);
86 }
88 memset (&sa, '\0', sizeof (sa));
89 sa.sun_family = AF_UNIX;
90 sstrncpy (sa.sun_path, (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
91 sizeof (sa.sun_path));
92 /* unlink (sa.sun_path); */
94 DEBUG ("unixsock plugin: socket path = %s", sa.sun_path);
96 status = bind (sock_fd, (struct sockaddr *) &sa, sizeof (sa));
97 if (status != 0)
98 {
99 char errbuf[1024];
100 sstrerror (errno, errbuf, sizeof (errbuf));
101 ERROR ("unixsock plugin: bind failed: %s", errbuf);
102 close (sock_fd);
103 sock_fd = -1;
104 return (-1);
105 }
107 chmod (sa.sun_path, sock_perms);
109 status = listen (sock_fd, 8);
110 if (status != 0)
111 {
112 char errbuf[1024];
113 ERROR ("unixsock plugin: listen failed: %s",
114 sstrerror (errno, errbuf, sizeof (errbuf)));
115 close (sock_fd);
116 sock_fd = -1;
117 return (-1);
118 }
120 do
121 {
122 char *grpname;
123 struct group *g;
124 struct group sg;
125 char grbuf[2048];
127 grpname = (sock_group != NULL) ? sock_group : COLLECTD_GRP_NAME;
128 g = NULL;
130 status = getgrnam_r (grpname, &sg, grbuf, sizeof (grbuf), &g);
131 if (status != 0)
132 {
133 char errbuf[1024];
134 WARNING ("unixsock plugin: getgrnam_r (%s) failed: %s", grpname,
135 sstrerror (errno, errbuf, sizeof (errbuf)));
136 break;
137 }
138 if (g == NULL)
139 {
140 WARNING ("unixsock plugin: No such group: `%s'",
141 grpname);
142 break;
143 }
145 if (chown ((sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
146 (uid_t) -1, g->gr_gid) != 0)
147 {
148 char errbuf[1024];
149 WARNING ("unixsock plugin: chown (%s, -1, %i) failed: %s",
150 (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
151 (int) g->gr_gid,
152 sstrerror (errno, errbuf, sizeof (errbuf)));
153 }
154 } while (0);
156 return (0);
157 } /* int us_open_socket */
159 static void *us_handle_client (void *arg)
160 {
161 int fdin;
162 int fdout;
163 FILE *fhin, *fhout;
165 fdin = *((int *) arg);
166 free (arg);
167 arg = NULL;
169 DEBUG ("unixsock plugin: us_handle_client: Reading from fd #%i", fdin);
171 fdout = dup (fdin);
172 if (fdout < 0)
173 {
174 char errbuf[1024];
175 ERROR ("unixsock plugin: dup failed: %s",
176 sstrerror (errno, errbuf, sizeof (errbuf)));
177 close (fdin);
178 pthread_exit ((void *) 1);
179 }
181 fhin = fdopen (fdin, "r");
182 if (fhin == NULL)
183 {
184 char errbuf[1024];
185 ERROR ("unixsock plugin: fdopen failed: %s",
186 sstrerror (errno, errbuf, sizeof (errbuf)));
187 close (fdin);
188 close (fdout);
189 pthread_exit ((void *) 1);
190 return ((void *) 1);
191 }
193 fhout = fdopen (fdout, "w");
194 if (fhout == NULL)
195 {
196 char errbuf[1024];
197 ERROR ("unixsock plugin: fdopen failed: %s",
198 sstrerror (errno, errbuf, sizeof (errbuf)));
199 fclose (fhin); /* this closes fdin as well */
200 close (fdout);
201 pthread_exit ((void *) 1);
202 return ((void *) 1);
203 }
205 /* change output buffer to line buffered mode */
206 if (setvbuf (fhout, NULL, _IOLBF, 0) != 0)
207 {
208 char errbuf[1024];
209 ERROR ("unixsock plugin: setvbuf failed: %s",
210 sstrerror (errno, errbuf, sizeof (errbuf)));
211 fclose (fhin);
212 fclose (fhout);
213 pthread_exit ((void *) 1);
214 return ((void *) 0);
215 }
217 while (42)
218 {
219 char buffer[1024];
220 char buffer_copy[1024];
221 char *fields[128];
222 int fields_num;
223 int len;
225 errno = 0;
226 if (fgets (buffer, sizeof (buffer), fhin) == NULL)
227 {
228 if ((errno == EINTR) || (errno == EAGAIN))
229 continue;
231 if (errno != 0)
232 {
233 char errbuf[1024];
234 WARNING ("unixsock plugin: failed to read from socket #%i: %s",
235 fileno (fhin),
236 sstrerror (errno, errbuf, sizeof (errbuf)));
237 }
238 break;
239 }
241 len = strlen (buffer);
242 while ((len > 0)
243 && ((buffer[len - 1] == '\n') || (buffer[len - 1] == '\r')))
244 buffer[--len] = '\0';
246 if (len == 0)
247 continue;
249 sstrncpy (buffer_copy, buffer, sizeof (buffer_copy));
251 fields_num = strsplit (buffer_copy, fields,
252 sizeof (fields) / sizeof (fields[0]));
253 if (fields_num < 1)
254 {
255 fprintf (fhout, "-1 Internal error\n");
256 fclose (fhin);
257 fclose (fhout);
258 pthread_exit ((void *) 1);
259 return ((void *) 1);
260 }
262 if (strcasecmp (fields[0], "getval") == 0)
263 {
264 handle_getval (fhout, buffer);
265 }
266 else if (strcasecmp (fields[0], "getthreshold") == 0)
267 {
268 handle_getthreshold (fhout, buffer);
269 }
270 else if (strcasecmp (fields[0], "putval") == 0)
271 {
272 handle_putval (fhout, buffer);
273 }
274 else if (strcasecmp (fields[0], "listval") == 0)
275 {
276 handle_listval (fhout, buffer);
277 }
278 else if (strcasecmp (fields[0], "putnotif") == 0)
279 {
280 handle_putnotif (fhout, buffer);
281 }
282 else if (strcasecmp (fields[0], "flush") == 0)
283 {
284 handle_flush (fhout, buffer);
285 }
286 else
287 {
288 if (fprintf (fhout, "-1 Unknown command: %s\n", fields[0]) < 0)
289 {
290 char errbuf[1024];
291 WARNING ("unixsock plugin: failed to write to socket #%i: %s",
292 fileno (fhout),
293 sstrerror (errno, errbuf, sizeof (errbuf)));
294 break;
295 }
296 }
297 } /* while (fgets) */
299 DEBUG ("unixsock plugin: us_handle_client: Exiting..");
300 fclose (fhin);
301 fclose (fhout);
303 pthread_exit ((void *) 0);
304 return ((void *) 0);
305 } /* void *us_handle_client */
307 static void *us_server_thread (void __attribute__((unused)) *arg)
308 {
309 int status;
310 int *remote_fd;
311 pthread_t th;
312 pthread_attr_t th_attr;
314 pthread_attr_init (&th_attr);
315 pthread_attr_setdetachstate (&th_attr, PTHREAD_CREATE_DETACHED);
317 if (us_open_socket () != 0)
318 pthread_exit ((void *) 1);
320 while (loop != 0)
321 {
322 DEBUG ("unixsock plugin: Calling accept..");
323 status = accept (sock_fd, NULL, NULL);
324 if (status < 0)
325 {
326 char errbuf[1024];
328 if (errno == EINTR)
329 continue;
331 ERROR ("unixsock plugin: accept failed: %s",
332 sstrerror (errno, errbuf, sizeof (errbuf)));
333 close (sock_fd);
334 sock_fd = -1;
335 pthread_attr_destroy (&th_attr);
336 pthread_exit ((void *) 1);
337 }
339 remote_fd = (int *) malloc (sizeof (int));
340 if (remote_fd == NULL)
341 {
342 char errbuf[1024];
343 WARNING ("unixsock plugin: malloc failed: %s",
344 sstrerror (errno, errbuf, sizeof (errbuf)));
345 close (status);
346 continue;
347 }
348 *remote_fd = status;
350 DEBUG ("Spawning child to handle connection on fd #%i", *remote_fd);
352 status = pthread_create (&th, &th_attr, us_handle_client, (void *) remote_fd);
353 if (status != 0)
354 {
355 char errbuf[1024];
356 WARNING ("unixsock plugin: pthread_create failed: %s",
357 sstrerror (errno, errbuf, sizeof (errbuf)));
358 close (*remote_fd);
359 free (remote_fd);
360 continue;
361 }
362 } /* while (loop) */
364 close (sock_fd);
365 sock_fd = -1;
366 pthread_attr_destroy (&th_attr);
368 status = unlink ((sock_file != NULL) ? sock_file : US_DEFAULT_PATH);
369 if (status != 0)
370 {
371 char errbuf[1024];
372 NOTICE ("unixsock plugin: unlink (%s) failed: %s",
373 (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
374 sstrerror (errno, errbuf, sizeof (errbuf)));
375 }
377 return ((void *) 0);
378 } /* void *us_server_thread */
380 static int us_config (const char *key, const char *val)
381 {
382 if (strcasecmp (key, "SocketFile") == 0)
383 {
384 char *new_sock_file = strdup (val);
385 if (new_sock_file == NULL)
386 return (1);
388 sfree (sock_file);
389 sock_file = new_sock_file;
390 }
391 else if (strcasecmp (key, "SocketGroup") == 0)
392 {
393 char *new_sock_group = strdup (val);
394 if (new_sock_group == NULL)
395 return (1);
397 sfree (sock_group);
398 sock_group = new_sock_group;
399 }
400 else if (strcasecmp (key, "SocketPerms") == 0)
401 {
402 sock_perms = (int) strtol (val, NULL, 8);
403 }
404 else
405 {
406 return (-1);
407 }
409 return (0);
410 } /* int us_config */
412 static int us_init (void)
413 {
414 static int have_init = 0;
416 int status;
418 /* Initialize only once. */
419 if (have_init != 0)
420 return (0);
421 have_init = 1;
423 loop = 1;
425 status = pthread_create (&listen_thread, NULL, us_server_thread, NULL);
426 if (status != 0)
427 {
428 char errbuf[1024];
429 ERROR ("unixsock plugin: pthread_create failed: %s",
430 sstrerror (errno, errbuf, sizeof (errbuf)));
431 return (-1);
432 }
434 return (0);
435 } /* int us_init */
437 static int us_shutdown (void)
438 {
439 void *ret;
441 loop = 0;
443 if (listen_thread != (pthread_t) 0)
444 {
445 pthread_kill (listen_thread, SIGTERM);
446 pthread_join (listen_thread, &ret);
447 listen_thread = (pthread_t) 0;
448 }
450 plugin_unregister_init ("unixsock");
451 plugin_unregister_shutdown ("unixsock");
453 return (0);
454 } /* int us_shutdown */
456 void module_register (void)
457 {
458 plugin_register_config ("unixsock", us_config,
459 config_keys, config_keys_num);
460 plugin_register_init ("unixsock", us_init);
461 plugin_register_shutdown ("unixsock", us_shutdown);
462 } /* void module_register (void) */
464 /* vim: set sw=4 ts=4 sts=4 tw=78 : */