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173fca4f JG |
1 | /* |
2 | * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com> | |
3 | * Copyright (C) 2018 - Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
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, version 2 only, as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
12 | * more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License along with | |
15 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
16 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
17 | */ | |
18 | ||
19 | #include "lttng-sessiond.h" | |
20 | #include "health-sessiond.h" | |
21 | #include <common/macros.h> | |
22 | #include <common/error.h> | |
23 | #include <common/utils.h> | |
24 | #include <common/pipe.h> | |
25 | #include <inttypes.h> | |
26 | #include <sys/stat.h> | |
27 | #include "utils.h" | |
28 | #include "thread.h" | |
29 | ||
c78d8e86 JG |
30 | struct thread_notifiers { |
31 | struct lttng_pipe *quit_pipe; | |
32 | sem_t ready; | |
33 | }; | |
34 | ||
35 | static | |
36 | void mark_thread_as_ready(struct thread_notifiers *notifiers) | |
173fca4f | 37 | { |
c78d8e86 JG |
38 | DBG("Marking health management thread as ready"); |
39 | sem_post(¬ifiers->ready); | |
40 | } | |
173fca4f | 41 | |
c78d8e86 JG |
42 | static |
43 | void wait_until_thread_is_ready(struct thread_notifiers *notifiers) | |
44 | { | |
45 | DBG("Waiting for health management thread to be ready"); | |
46 | sem_wait(¬ifiers->ready); | |
47 | DBG("Health management thread is ready"); | |
48 | } | |
49 | ||
50 | static void cleanup_health_management_thread(void *data) | |
51 | { | |
52 | struct thread_notifiers *notifiers = data; | |
53 | ||
54 | lttng_pipe_destroy(notifiers->quit_pipe); | |
55 | sem_destroy(¬ifiers->ready); | |
56 | free(notifiers); | |
173fca4f JG |
57 | } |
58 | ||
59 | /* | |
60 | * Thread managing health check socket. | |
61 | */ | |
c78d8e86 | 62 | static void *thread_manage_health(void *data) |
173fca4f JG |
63 | { |
64 | const bool is_root = (getuid() == 0); | |
65 | int sock = -1, new_sock = -1, ret, i, pollfd, err = -1; | |
66 | uint32_t revents, nb_fd; | |
67 | struct lttng_poll_event events; | |
68 | struct health_comm_msg msg; | |
69 | struct health_comm_reply reply; | |
70 | /* Thread-specific quit pipe. */ | |
c78d8e86 JG |
71 | struct thread_notifiers *notifiers = data; |
72 | const int quit_pipe_read_fd = lttng_pipe_get_readfd( | |
73 | notifiers->quit_pipe); | |
173fca4f JG |
74 | |
75 | DBG("[thread] Manage health check started"); | |
76 | ||
77 | rcu_register_thread(); | |
78 | ||
79 | /* | |
80 | * Created with a size of two for: | |
81 | * - client socket | |
82 | * - thread quit pipe | |
83 | */ | |
84 | ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC); | |
85 | if (ret < 0) { | |
86 | goto error; | |
87 | } | |
88 | ||
89 | /* Create unix socket */ | |
90 | sock = lttcomm_create_unix_sock(config.health_unix_sock_path.value); | |
91 | if (sock < 0) { | |
92 | ERR("Unable to create health check Unix socket"); | |
93 | goto error; | |
94 | } | |
95 | ||
96 | if (is_root) { | |
97 | /* lttng health client socket path permissions */ | |
28ab59d0 JR |
98 | gid_t gid; |
99 | ||
100 | ret = utils_get_group_id(config.tracing_group_name.value, true, &gid); | |
101 | if (ret) { | |
102 | /* Default to root group. */ | |
103 | gid = 0; | |
104 | } | |
105 | ||
106 | ret = chown(config.health_unix_sock_path.value, 0, gid); | |
173fca4f JG |
107 | if (ret < 0) { |
108 | ERR("Unable to set group on %s", config.health_unix_sock_path.value); | |
109 | PERROR("chown"); | |
110 | goto error; | |
111 | } | |
112 | ||
113 | ret = chmod(config.health_unix_sock_path.value, | |
114 | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP); | |
115 | if (ret < 0) { | |
116 | ERR("Unable to set permissions on %s", config.health_unix_sock_path.value); | |
117 | PERROR("chmod"); | |
118 | goto error; | |
119 | } | |
120 | } | |
121 | ||
122 | /* | |
123 | * Set the CLOEXEC flag. Return code is useless because either way, the | |
124 | * show must go on. | |
125 | */ | |
126 | (void) utils_set_fd_cloexec(sock); | |
127 | ||
128 | ret = lttcomm_listen_unix_sock(sock); | |
129 | if (ret < 0) { | |
130 | goto error; | |
131 | } | |
132 | ||
133 | ret = lttng_poll_add(&events, quit_pipe_read_fd, LPOLLIN | LPOLLERR); | |
134 | if (ret < 0) { | |
135 | goto error; | |
136 | } | |
137 | ||
138 | /* Add the application registration socket */ | |
139 | ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLPRI); | |
140 | if (ret < 0) { | |
141 | goto error; | |
142 | } | |
143 | ||
c78d8e86 | 144 | mark_thread_as_ready(notifiers); |
173fca4f JG |
145 | while (1) { |
146 | DBG("Health check ready"); | |
147 | ||
148 | /* Infinite blocking call, waiting for transmission */ | |
149 | restart: | |
150 | ret = lttng_poll_wait(&events, -1); | |
151 | if (ret < 0) { | |
152 | /* | |
153 | * Restart interrupted system call. | |
154 | */ | |
155 | if (errno == EINTR) { | |
156 | goto restart; | |
157 | } | |
158 | goto error; | |
159 | } | |
160 | ||
161 | nb_fd = ret; | |
162 | ||
163 | for (i = 0; i < nb_fd; i++) { | |
164 | /* Fetch once the poll data */ | |
165 | revents = LTTNG_POLL_GETEV(&events, i); | |
166 | pollfd = LTTNG_POLL_GETFD(&events, i); | |
167 | ||
173fca4f JG |
168 | /* Event on the registration socket */ |
169 | if (pollfd == sock) { | |
170 | if (revents & LPOLLIN) { | |
171 | continue; | |
172 | } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { | |
173 | ERR("Health socket poll error"); | |
174 | goto error; | |
175 | } else { | |
176 | ERR("Unexpected poll events %u for sock %d", revents, pollfd); | |
177 | goto error; | |
178 | } | |
179 | } else { | |
180 | /* Event on the thread's quit pipe. */ | |
181 | err = 0; | |
182 | goto exit; | |
183 | } | |
184 | } | |
185 | ||
186 | new_sock = lttcomm_accept_unix_sock(sock); | |
187 | if (new_sock < 0) { | |
188 | goto error; | |
189 | } | |
190 | ||
191 | /* | |
192 | * Set the CLOEXEC flag. Return code is useless because either way, the | |
193 | * show must go on. | |
194 | */ | |
195 | (void) utils_set_fd_cloexec(new_sock); | |
196 | ||
197 | DBG("Receiving data from client for health..."); | |
198 | ret = lttcomm_recv_unix_sock(new_sock, (void *)&msg, sizeof(msg)); | |
199 | if (ret <= 0) { | |
200 | DBG("Nothing recv() from client... continuing"); | |
201 | ret = close(new_sock); | |
202 | if (ret) { | |
203 | PERROR("close"); | |
204 | } | |
205 | continue; | |
206 | } | |
207 | ||
208 | rcu_thread_online(); | |
209 | ||
210 | memset(&reply, 0, sizeof(reply)); | |
211 | for (i = 0; i < NR_HEALTH_SESSIOND_TYPES; i++) { | |
212 | /* | |
213 | * health_check_state returns 0 if health is | |
214 | * bad. | |
215 | */ | |
216 | if (!health_check_state(health_sessiond, i)) { | |
217 | reply.ret_code |= 1ULL << i; | |
218 | } | |
219 | } | |
220 | ||
221 | DBG2("Health check return value %" PRIx64, reply.ret_code); | |
222 | ||
223 | ret = lttcomm_send_unix_sock(new_sock, (void *) &reply, | |
224 | sizeof(reply)); | |
225 | if (ret < 0) { | |
226 | ERR("Failed to send health data back to client"); | |
227 | } | |
228 | ||
229 | /* End of transmission */ | |
230 | ret = close(new_sock); | |
231 | if (ret) { | |
232 | PERROR("close"); | |
233 | } | |
234 | } | |
235 | ||
236 | exit: | |
237 | error: | |
238 | if (err) { | |
239 | ERR("Health error occurred in %s", __func__); | |
240 | } | |
241 | DBG("Health check thread dying"); | |
242 | unlink(config.health_unix_sock_path.value); | |
243 | if (sock >= 0) { | |
244 | ret = close(sock); | |
245 | if (ret) { | |
246 | PERROR("close"); | |
247 | } | |
248 | } | |
249 | ||
250 | lttng_poll_clean(&events); | |
251 | rcu_unregister_thread(); | |
252 | return NULL; | |
253 | } | |
254 | ||
c78d8e86 | 255 | static bool shutdown_health_management_thread(void *data) |
173fca4f | 256 | { |
c78d8e86 JG |
257 | struct thread_notifiers *notifiers = data; |
258 | const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe); | |
173fca4f | 259 | |
c78d8e86 | 260 | return notify_thread_pipe(write_fd) == 1; |
173fca4f JG |
261 | } |
262 | ||
263 | bool launch_health_management_thread(void) | |
264 | { | |
c78d8e86 | 265 | struct thread_notifiers *notifiers; |
173fca4f | 266 | struct lttng_thread *thread; |
173fca4f | 267 | |
c78d8e86 JG |
268 | notifiers = zmalloc(sizeof(*notifiers)); |
269 | if (!notifiers) { | |
21fa020e | 270 | goto error_alloc; |
173fca4f JG |
271 | } |
272 | ||
c78d8e86 JG |
273 | sem_init(¬ifiers->ready, 0, 0); |
274 | notifiers->quit_pipe = lttng_pipe_open(FD_CLOEXEC); | |
275 | if (!notifiers->quit_pipe) { | |
276 | goto error; | |
277 | } | |
173fca4f JG |
278 | thread = lttng_thread_create("Health management", |
279 | thread_manage_health, | |
280 | shutdown_health_management_thread, | |
281 | cleanup_health_management_thread, | |
c78d8e86 | 282 | notifiers); |
173fca4f JG |
283 | if (!thread) { |
284 | goto error; | |
285 | } | |
c78d8e86 JG |
286 | |
287 | wait_until_thread_is_ready(notifiers); | |
173fca4f JG |
288 | lttng_thread_put(thread); |
289 | return true; | |
290 | error: | |
c78d8e86 | 291 | cleanup_health_management_thread(notifiers); |
21fa020e | 292 | error_alloc: |
173fca4f JG |
293 | return false; |
294 | } |