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 **/
26
27 #include "collectd.h"
28
29 #include "plugin.h"
30 #include "utils/common/common.h"
31
32 #include "utils/cmds/flush.h"
33 #include "utils/cmds/getthreshold.h"
34 #include "utils/cmds/getval.h"
35 #include "utils/cmds/listval.h"
36 #include "utils/cmds/putnotif.h"
37 #include "utils/cmds/putval.h"
38
39 #include <sys/stat.h>
40 #include <sys/un.h>
41
42 #include <grp.h>
43
44 #ifndef UNIX_PATH_MAX
45 #define UNIX_PATH_MAX sizeof(((struct sockaddr_un *)0)->sun_path)
46 #endif
47
48 #define US_DEFAULT_PATH LOCALSTATEDIR "/run/" PACKAGE_NAME "-unixsock"
49
50 /*
51 * Private variables
52 */
53 /* valid configuration file keys */
54 static const char *config_keys[] = {"SocketFile", "SocketGroup", "SocketPerms",
55 "DeleteSocket"};
56 static int config_keys_num = STATIC_ARRAY_SIZE(config_keys);
57
58 static int loop;
59
60 /* socket configuration */
61 static int sock_fd = -1;
62 static char *sock_file;
63 static char *sock_group;
64 static int sock_perms = S_IRWXU | S_IRWXG;
65 static bool delete_socket;
66
67 static pthread_t listen_thread = (pthread_t)0;
68
69 /*
70 * Functions
71 */
us_open_socket(void)72 static int us_open_socket(void) {
73 struct sockaddr_un sa = {0};
74 int status;
75
76 sock_fd = socket(PF_UNIX, SOCK_STREAM, 0);
77 if (sock_fd < 0) {
78 ERROR("unixsock plugin: socket failed: %s", STRERRNO);
79 return -1;
80 }
81
82 sa.sun_family = AF_UNIX;
83 sstrncpy(sa.sun_path, (sock_file != NULL) ? sock_file : US_DEFAULT_PATH,
84 sizeof(sa.sun_path));
85
86 DEBUG("unixsock plugin: socket path = %s", sa.sun_path);
87
88 if (delete_socket) {
89 errno = 0;
90 status = unlink(sa.sun_path);
91 if ((status != 0) && (errno != ENOENT)) {
92 WARNING("unixsock plugin: Deleting socket file \"%s\" failed: %s",
93 sa.sun_path, STRERRNO);
94 } else if (status == 0) {
95 INFO("unixsock plugin: Successfully deleted socket file \"%s\".",
96 sa.sun_path);
97 }
98 }
99
100 status = bind(sock_fd, (struct sockaddr *)&sa, sizeof(sa));
101 if (status != 0) {
102 ERROR("unixsock plugin: bind failed: %s", STRERRNO);
103 close(sock_fd);
104 sock_fd = -1;
105 return -1;
106 }
107
108 status = chmod(sa.sun_path, sock_perms);
109 if (status == -1) {
110 ERROR("unixsock plugin: chmod failed: %s", STRERRNO);
111 close(sock_fd);
112 sock_fd = -1;
113 return -1;
114 }
115
116 status = listen(sock_fd, 8);
117 if (status != 0) {
118 ERROR("unixsock plugin: listen failed: %s", STRERRNO);
119 close(sock_fd);
120 sock_fd = -1;
121 return -1;
122 }
123
124 do {
125 const char *grpname;
126 struct group *g;
127 struct group sg;
128
129 long int grbuf_size = sysconf(_SC_GETGR_R_SIZE_MAX);
130 if (grbuf_size <= 0)
131 grbuf_size = sysconf(_SC_PAGESIZE);
132 if (grbuf_size <= 0)
133 grbuf_size = 4096;
134 char grbuf[grbuf_size];
135
136 grpname = (sock_group != NULL) ? sock_group : COLLECTD_GRP_NAME;
137 g = NULL;
138
139 status = getgrnam_r(grpname, &sg, grbuf, sizeof(grbuf), &g);
140 if (status != 0) {
141 WARNING("unixsock plugin: getgrnam_r (%s) failed: %s", grpname,
142 STRERROR(status));
143 break;
144 }
145 if (g == NULL) {
146 WARNING("unixsock plugin: No such group: `%s'", grpname);
147 break;
148 }
149
150 if (chown((sock_file != NULL) ? sock_file : US_DEFAULT_PATH, (uid_t)-1,
151 g->gr_gid) != 0) {
152 WARNING("unixsock plugin: chown (%s, -1, %i) failed: %s",
153 (sock_file != NULL) ? sock_file : US_DEFAULT_PATH, (int)g->gr_gid,
154 STRERRNO);
155 }
156 } while (0);
157
158 return 0;
159 } /* int us_open_socket */
160
us_handle_client(void * arg)161 static void *us_handle_client(void *arg) {
162 int fdin;
163 int fdout;
164 FILE *fhin, *fhout;
165
166 fdin = *((int *)arg);
167 free(arg);
168 arg = NULL;
169
170 DEBUG("unixsock plugin: us_handle_client: Reading from fd #%i", fdin);
171
172 fdout = dup(fdin);
173 if (fdout < 0) {
174 ERROR("unixsock plugin: dup failed: %s", STRERRNO);
175 close(fdin);
176 pthread_exit((void *)1);
177 }
178
179 fhin = fdopen(fdin, "r");
180 if (fhin == NULL) {
181 ERROR("unixsock plugin: fdopen failed: %s", STRERRNO);
182 close(fdin);
183 close(fdout);
184 pthread_exit((void *)1);
185 return (void *)1;
186 }
187
188 fhout = fdopen(fdout, "w");
189 if (fhout == NULL) {
190 ERROR("unixsock plugin: fdopen failed: %s", STRERRNO);
191 fclose(fhin); /* this closes fdin as well */
192 close(fdout);
193 pthread_exit((void *)1);
194 return (void *)1;
195 }
196
197 /* change output buffer to line buffered mode */
198 if (setvbuf(fhout, NULL, _IOLBF, 0) != 0) {
199 ERROR("unixsock plugin: setvbuf failed: %s", STRERRNO);
200 fclose(fhin);
201 fclose(fhout);
202 pthread_exit((void *)1);
203 return (void *)0;
204 }
205
206 while (42) {
207 char buffer[1024];
208 char buffer_copy[1024];
209 char *fields[128];
210 int fields_num;
211
212 errno = 0;
213 if (fgets(buffer, sizeof(buffer), fhin) == NULL) {
214 if ((errno == EINTR) || (errno == EAGAIN))
215 continue;
216
217 if (errno != 0) {
218 WARNING("unixsock plugin: failed to read from socket #%i: %s",
219 fileno(fhin), STRERRNO);
220 }
221 break;
222 }
223
224 size_t len = strlen(buffer);
225 while ((len > 0) &&
226 ((buffer[len - 1] == '\n') || (buffer[len - 1] == '\r')))
227 buffer[--len] = '\0';
228
229 if (len == 0)
230 continue;
231
232 sstrncpy(buffer_copy, buffer, sizeof(buffer_copy));
233
234 fields_num =
235 strsplit(buffer_copy, fields, sizeof(fields) / sizeof(fields[0]));
236 if (fields_num < 1) {
237 fprintf(fhout, "-1 Internal error\n");
238 fclose(fhin);
239 fclose(fhout);
240 pthread_exit((void *)1);
241 return (void *)1;
242 }
243
244 if (strcasecmp(fields[0], "getval") == 0) {
245 cmd_handle_getval(fhout, buffer);
246 } else if (strcasecmp(fields[0], "getthreshold") == 0) {
247 handle_getthreshold(fhout, buffer);
248 } else if (strcasecmp(fields[0], "putval") == 0) {
249 cmd_handle_putval(fhout, buffer);
250 } else if (strcasecmp(fields[0], "listval") == 0) {
251 cmd_handle_listval(fhout, buffer);
252 } else if (strcasecmp(fields[0], "putnotif") == 0) {
253 handle_putnotif(fhout, buffer);
254 } else if (strcasecmp(fields[0], "flush") == 0) {
255 cmd_handle_flush(fhout, buffer);
256 } else {
257 if (fprintf(fhout, "-1 Unknown command: %s\n", fields[0]) < 0) {
258 WARNING("unixsock plugin: failed to write to socket #%i: %s",
259 fileno(fhout), STRERRNO);
260 break;
261 }
262 }
263 } /* while (fgets) */
264
265 DEBUG("unixsock plugin: us_handle_client: Exiting..");
266 fclose(fhin);
267 fclose(fhout);
268
269 pthread_exit((void *)0);
270 return (void *)0;
271 } /* void *us_handle_client */
272
us_server_thread(void * arg)273 static void *us_server_thread(void __attribute__((unused)) * arg) {
274 int status;
275 int *remote_fd;
276 pthread_t th;
277
278 if (us_open_socket() != 0)
279 pthread_exit((void *)1);
280
281 while (loop != 0) {
282 DEBUG("unixsock plugin: Calling accept..");
283 status = accept(sock_fd, NULL, NULL);
284 if (status < 0) {
285
286 if (errno == EINTR)
287 continue;
288
289 ERROR("unixsock plugin: accept failed: %s", STRERRNO);
290 close(sock_fd);
291 sock_fd = -1;
292 pthread_exit((void *)1);
293 }
294
295 remote_fd = malloc(sizeof(*remote_fd));
296 if (remote_fd == NULL) {
297 WARNING("unixsock plugin: malloc failed: %s", STRERRNO);
298 close(status);
299 continue;
300 }
301 *remote_fd = status;
302
303 DEBUG("Spawning child to handle connection on fd #%i", *remote_fd);
304
305 status = plugin_thread_create(&th, us_handle_client, (void *)remote_fd,
306 "unixsock conn");
307 if (status == 0) {
308 pthread_detach(th);
309 } else {
310 WARNING("unixsock plugin: pthread_create failed: %s", STRERRNO);
311 close(*remote_fd);
312 free(remote_fd);
313 continue;
314 }
315 } /* while (loop) */
316
317 close(sock_fd);
318 sock_fd = -1;
319
320 status = unlink((sock_file != NULL) ? sock_file : US_DEFAULT_PATH);
321 if (status != 0) {
322 NOTICE("unixsock plugin: unlink (%s) failed: %s",
323 (sock_file != NULL) ? sock_file : US_DEFAULT_PATH, STRERRNO);
324 }
325
326 return (void *)0;
327 } /* void *us_server_thread */
328
us_config(const char * key,const char * val)329 static int us_config(const char *key, const char *val) {
330 if (strcasecmp(key, "SocketFile") == 0) {
331 char *new_sock_file = strdup(val);
332 if (new_sock_file == NULL)
333 return 1;
334
335 sfree(sock_file);
336 sock_file = new_sock_file;
337 } else if (strcasecmp(key, "SocketGroup") == 0) {
338 char *new_sock_group = strdup(val);
339 if (new_sock_group == NULL)
340 return 1;
341
342 sfree(sock_group);
343 sock_group = new_sock_group;
344 } else if (strcasecmp(key, "SocketPerms") == 0) {
345 sock_perms = (int)strtol(val, NULL, 8);
346 } else if (strcasecmp(key, "DeleteSocket") == 0) {
347 if (IS_TRUE(val))
348 delete_socket = true;
349 else
350 delete_socket = false;
351 } else {
352 return -1;
353 }
354
355 return 0;
356 } /* int us_config */
357
us_init(void)358 static int us_init(void) {
359 static int have_init;
360
361 int status;
362
363 /* Initialize only once. */
364 if (have_init != 0)
365 return 0;
366 have_init = 1;
367
368 loop = 1;
369
370 status = plugin_thread_create(&listen_thread, us_server_thread, NULL,
371 "unixsock listen");
372 if (status != 0) {
373 ERROR("unixsock plugin: pthread_create failed: %s", STRERRNO);
374 return -1;
375 }
376
377 return 0;
378 } /* int us_init */
379
us_shutdown(void)380 static int us_shutdown(void) {
381 void *ret;
382
383 loop = 0;
384
385 if (listen_thread != (pthread_t)0) {
386 pthread_kill(listen_thread, SIGTERM);
387 pthread_join(listen_thread, &ret);
388 listen_thread = (pthread_t)0;
389 }
390
391 plugin_unregister_init("unixsock");
392 plugin_unregister_shutdown("unixsock");
393
394 return 0;
395 } /* int us_shutdown */
396
module_register(void)397 void module_register(void) {
398 plugin_register_config("unixsock", us_config, config_keys, config_keys_num);
399 plugin_register_init("unixsock", us_init);
400 plugin_register_shutdown("unixsock", us_shutdown);
401 } /* void module_register (void) */
402