sessiond: make functions static in ust-registry.c
[lttng-tools.git] / src / bin / lttng-consumerd / health-consumerd.c
1 /*
2 * Copyright (C) 2013 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _LGPL_SOURCE
19 #include <fcntl.h>
20 #include <getopt.h>
21 #include <grp.h>
22 #include <limits.h>
23 #include <pthread.h>
24 #include <signal.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <sys/ipc.h>
29 #include <sys/resource.h>
30 #include <sys/shm.h>
31 #include <sys/socket.h>
32 #include <sys/stat.h>
33 #include <sys/types.h>
34 #include <urcu/list.h>
35 #include <poll.h>
36 #include <unistd.h>
37 #include <sys/mman.h>
38 #include <assert.h>
39 #include <urcu/compiler.h>
40 #include <ulimit.h>
41 #include <inttypes.h>
42
43 #include <common/defaults.h>
44 #include <common/common.h>
45 #include <common/consumer/consumer.h>
46 #include <common/consumer/consumer-timer.h>
47 #include <common/compat/poll.h>
48 #include <common/sessiond-comm/sessiond-comm.h>
49 #include <common/utils.h>
50
51 #include "lttng-consumerd.h"
52 #include "health-consumerd.h"
53
54 /* Global health check unix path */
55 static char health_unix_sock_path[PATH_MAX];
56
57 int health_quit_pipe[2];
58
59 /*
60 * Check if the thread quit pipe was triggered.
61 *
62 * Return 1 if it was triggered else 0;
63 */
64 static
65 int check_health_quit_pipe(int fd, uint32_t events)
66 {
67 if (fd == health_quit_pipe[0] && (events & LPOLLIN)) {
68 return 1;
69 }
70
71 return 0;
72 }
73
74 /*
75 * Send data on a unix socket using the liblttsessiondcomm API.
76 *
77 * Return lttcomm error code.
78 */
79 static int send_unix_sock(int sock, void *buf, size_t len)
80 {
81 /* Check valid length */
82 if (len == 0) {
83 return -1;
84 }
85
86 return lttcomm_send_unix_sock(sock, buf, len);
87 }
88
89 static
90 int setup_health_path(void)
91 {
92 int is_root, ret = 0;
93 enum lttng_consumer_type type;
94 const char *home_path;
95
96 type = lttng_consumer_get_type();
97 is_root = !getuid();
98
99 if (is_root) {
100 if (strlen(health_unix_sock_path) != 0) {
101 goto end;
102 }
103 switch (type) {
104 case LTTNG_CONSUMER_KERNEL:
105 snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
106 DEFAULT_GLOBAL_KCONSUMER_HEALTH_UNIX_SOCK);
107 break;
108 case LTTNG_CONSUMER64_UST:
109 snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
110 DEFAULT_GLOBAL_USTCONSUMER64_HEALTH_UNIX_SOCK);
111 break;
112 case LTTNG_CONSUMER32_UST:
113 snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
114 DEFAULT_GLOBAL_USTCONSUMER32_HEALTH_UNIX_SOCK);
115 break;
116 default:
117 ret = -EINVAL;
118 goto end;
119 }
120 } else {
121 home_path = utils_get_home_dir();
122 if (home_path == NULL) {
123 /* TODO: Add --socket PATH option */
124 ERR("Can't get HOME directory for sockets creation.");
125 ret = -EPERM;
126 goto end;
127 }
128
129 /* Set health check Unix path */
130 if (strlen(health_unix_sock_path) != 0) {
131 goto end;
132 }
133 switch (type) {
134 case LTTNG_CONSUMER_KERNEL:
135 snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
136 DEFAULT_HOME_KCONSUMER_HEALTH_UNIX_SOCK, home_path);
137 break;
138 case LTTNG_CONSUMER64_UST:
139 snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
140 DEFAULT_HOME_USTCONSUMER64_HEALTH_UNIX_SOCK, home_path);
141 break;
142 case LTTNG_CONSUMER32_UST:
143 snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
144 DEFAULT_HOME_USTCONSUMER32_HEALTH_UNIX_SOCK, home_path);
145 break;
146 default:
147 ret = -EINVAL;
148 goto end;
149 }
150 }
151 end:
152 return ret;
153 }
154
155 /*
156 * Thread managing health check socket.
157 */
158 void *thread_manage_health(void *data)
159 {
160 int sock = -1, new_sock = -1, ret, i, pollfd, err = -1;
161 uint32_t revents, nb_fd;
162 struct lttng_poll_event events;
163 struct health_comm_msg msg;
164 struct health_comm_reply reply;
165 int is_root;
166
167 DBG("[thread] Manage health check started");
168
169 setup_health_path();
170
171 rcu_register_thread();
172
173 /* We might hit an error path before this is created. */
174 lttng_poll_init(&events);
175
176 /* Create unix socket */
177 sock = lttcomm_create_unix_sock(health_unix_sock_path);
178 if (sock < 0) {
179 ERR("Unable to create health check Unix socket");
180 err = -1;
181 goto error;
182 }
183
184 is_root = !getuid();
185 if (is_root) {
186 /* lttng health client socket path permissions */
187 gid_t gid;
188
189 ret = utils_get_group_id(tracing_group_name, true, &gid);
190 if (ret) {
191 /* Default to root group. */
192 gid = 0;
193 }
194
195 ret = chown(health_unix_sock_path, 0, gid);
196 if (ret < 0) {
197 ERR("Unable to set group on %s", health_unix_sock_path);
198 PERROR("chown");
199 err = -1;
200 goto error;
201 }
202
203 ret = chmod(health_unix_sock_path,
204 S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
205 if (ret < 0) {
206 ERR("Unable to set permissions on %s", health_unix_sock_path);
207 PERROR("chmod");
208 err = -1;
209 goto error;
210 }
211 }
212
213 /*
214 * Set the CLOEXEC flag. Return code is useless because either way, the
215 * show must go on.
216 */
217 (void) utils_set_fd_cloexec(sock);
218
219 ret = lttcomm_listen_unix_sock(sock);
220 if (ret < 0) {
221 goto error;
222 }
223
224 /* Size is set to 1 for the consumer_channel pipe */
225 ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
226 if (ret < 0) {
227 ERR("Poll set creation failed");
228 goto error;
229 }
230
231 ret = lttng_poll_add(&events, health_quit_pipe[0], LPOLLIN);
232 if (ret < 0) {
233 goto error;
234 }
235
236 /* Add the application registration socket */
237 ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLPRI);
238 if (ret < 0) {
239 goto error;
240 }
241
242 /* Perform prior memory accesses before decrementing ready */
243 cmm_smp_mb__before_uatomic_dec();
244 uatomic_dec(&lttng_consumer_ready);
245
246 while (1) {
247 DBG("Health check ready");
248
249 /* Inifinite blocking call, waiting for transmission */
250 restart:
251 ret = lttng_poll_wait(&events, -1);
252 if (ret < 0) {
253 /*
254 * Restart interrupted system call.
255 */
256 if (errno == EINTR) {
257 goto restart;
258 }
259 goto error;
260 }
261
262 nb_fd = ret;
263
264 for (i = 0; i < nb_fd; i++) {
265 /* Fetch once the poll data */
266 revents = LTTNG_POLL_GETEV(&events, i);
267 pollfd = LTTNG_POLL_GETFD(&events, i);
268
269 /* Thread quit pipe has been closed. Killing thread. */
270 ret = check_health_quit_pipe(pollfd, revents);
271 if (ret) {
272 err = 0;
273 goto exit;
274 }
275
276 /* Event on the registration socket */
277 if (pollfd == sock) {
278 if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)
279 && !(revents & LPOLLIN)) {
280 ERR("Health socket poll error");
281 goto error;
282 }
283 }
284 }
285
286 new_sock = lttcomm_accept_unix_sock(sock);
287 if (new_sock < 0) {
288 goto error;
289 }
290
291 /*
292 * Set the CLOEXEC flag. Return code is useless because either way, the
293 * show must go on.
294 */
295 (void) utils_set_fd_cloexec(new_sock);
296
297 DBG("Receiving data from client for health...");
298 ret = lttcomm_recv_unix_sock(new_sock, (void *)&msg, sizeof(msg));
299 if (ret <= 0) {
300 DBG("Nothing recv() from client... continuing");
301 ret = close(new_sock);
302 if (ret) {
303 PERROR("close");
304 }
305 new_sock = -1;
306 continue;
307 }
308
309 rcu_thread_online();
310
311 assert(msg.cmd == HEALTH_CMD_CHECK);
312
313 memset(&reply, 0, sizeof(reply));
314 for (i = 0; i < NR_HEALTH_CONSUMERD_TYPES; i++) {
315 /*
316 * health_check_state return 0 if thread is in
317 * error.
318 */
319 if (!health_check_state(health_consumerd, i)) {
320 reply.ret_code |= 1ULL << i;
321 }
322 }
323
324 DBG("Health check return value %" PRIx64, reply.ret_code);
325
326 ret = send_unix_sock(new_sock, (void *) &reply, sizeof(reply));
327 if (ret < 0) {
328 ERR("Failed to send health data back to client");
329 }
330
331 /* End of transmission */
332 ret = close(new_sock);
333 if (ret) {
334 PERROR("close");
335 }
336 new_sock = -1;
337 }
338
339 exit:
340 error:
341 if (err) {
342 ERR("Health error occurred in %s", __func__);
343 }
344 DBG("Health check thread dying");
345 unlink(health_unix_sock_path);
346 if (sock >= 0) {
347 ret = close(sock);
348 if (ret) {
349 PERROR("close");
350 }
351 }
352
353 lttng_poll_clean(&events);
354
355 rcu_unregister_thread();
356 return NULL;
357 }
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