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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 | ||
30 | static void cleanup_health_management_thread(void *thread_data) | |
31 | { | |
32 | struct lttng_pipe *quit_pipe = thread_data; | |
33 | ||
34 | lttng_pipe_destroy(quit_pipe); | |
35 | } | |
36 | ||
37 | /* | |
38 | * Thread managing health check socket. | |
39 | */ | |
40 | static void *thread_manage_health(void *thread_data) | |
41 | { | |
42 | const bool is_root = (getuid() == 0); | |
43 | int sock = -1, new_sock = -1, ret, i, pollfd, err = -1; | |
44 | uint32_t revents, nb_fd; | |
45 | struct lttng_poll_event events; | |
46 | struct health_comm_msg msg; | |
47 | struct health_comm_reply reply; | |
48 | /* Thread-specific quit pipe. */ | |
49 | struct lttng_pipe *quit_pipe = thread_data; | |
50 | const int quit_pipe_read_fd = lttng_pipe_get_readfd(quit_pipe); | |
51 | ||
52 | DBG("[thread] Manage health check started"); | |
53 | ||
54 | rcu_register_thread(); | |
55 | ||
56 | /* | |
57 | * Created with a size of two for: | |
58 | * - client socket | |
59 | * - thread quit pipe | |
60 | */ | |
61 | ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC); | |
62 | if (ret < 0) { | |
63 | goto error; | |
64 | } | |
65 | ||
66 | /* Create unix socket */ | |
67 | sock = lttcomm_create_unix_sock(config.health_unix_sock_path.value); | |
68 | if (sock < 0) { | |
69 | ERR("Unable to create health check Unix socket"); | |
70 | goto error; | |
71 | } | |
72 | ||
73 | if (is_root) { | |
74 | /* lttng health client socket path permissions */ | |
75 | ret = chown(config.health_unix_sock_path.value, 0, | |
76 | utils_get_group_id(config.tracing_group_name.value)); | |
77 | if (ret < 0) { | |
78 | ERR("Unable to set group on %s", config.health_unix_sock_path.value); | |
79 | PERROR("chown"); | |
80 | goto error; | |
81 | } | |
82 | ||
83 | ret = chmod(config.health_unix_sock_path.value, | |
84 | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP); | |
85 | if (ret < 0) { | |
86 | ERR("Unable to set permissions on %s", config.health_unix_sock_path.value); | |
87 | PERROR("chmod"); | |
88 | goto error; | |
89 | } | |
90 | } | |
91 | ||
92 | /* | |
93 | * Set the CLOEXEC flag. Return code is useless because either way, the | |
94 | * show must go on. | |
95 | */ | |
96 | (void) utils_set_fd_cloexec(sock); | |
97 | ||
98 | ret = lttcomm_listen_unix_sock(sock); | |
99 | if (ret < 0) { | |
100 | goto error; | |
101 | } | |
102 | ||
103 | ret = lttng_poll_add(&events, quit_pipe_read_fd, LPOLLIN | LPOLLERR); | |
104 | if (ret < 0) { | |
105 | goto error; | |
106 | } | |
107 | ||
108 | /* Add the application registration socket */ | |
109 | ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLPRI); | |
110 | if (ret < 0) { | |
111 | goto error; | |
112 | } | |
113 | ||
114 | sessiond_notify_ready(); | |
115 | ||
116 | while (1) { | |
117 | DBG("Health check ready"); | |
118 | ||
119 | /* Infinite blocking call, waiting for transmission */ | |
120 | restart: | |
121 | ret = lttng_poll_wait(&events, -1); | |
122 | if (ret < 0) { | |
123 | /* | |
124 | * Restart interrupted system call. | |
125 | */ | |
126 | if (errno == EINTR) { | |
127 | goto restart; | |
128 | } | |
129 | goto error; | |
130 | } | |
131 | ||
132 | nb_fd = ret; | |
133 | ||
134 | for (i = 0; i < nb_fd; i++) { | |
135 | /* Fetch once the poll data */ | |
136 | revents = LTTNG_POLL_GETEV(&events, i); | |
137 | pollfd = LTTNG_POLL_GETFD(&events, i); | |
138 | ||
139 | if (!revents) { | |
140 | /* No activity for this FD (poll implementation). */ | |
141 | continue; | |
142 | } | |
143 | ||
144 | /* Event on the registration socket */ | |
145 | if (pollfd == sock) { | |
146 | if (revents & LPOLLIN) { | |
147 | continue; | |
148 | } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) { | |
149 | ERR("Health socket poll error"); | |
150 | goto error; | |
151 | } else { | |
152 | ERR("Unexpected poll events %u for sock %d", revents, pollfd); | |
153 | goto error; | |
154 | } | |
155 | } else { | |
156 | /* Event on the thread's quit pipe. */ | |
157 | err = 0; | |
158 | goto exit; | |
159 | } | |
160 | } | |
161 | ||
162 | new_sock = lttcomm_accept_unix_sock(sock); | |
163 | if (new_sock < 0) { | |
164 | goto error; | |
165 | } | |
166 | ||
167 | /* | |
168 | * Set the CLOEXEC flag. Return code is useless because either way, the | |
169 | * show must go on. | |
170 | */ | |
171 | (void) utils_set_fd_cloexec(new_sock); | |
172 | ||
173 | DBG("Receiving data from client for health..."); | |
174 | ret = lttcomm_recv_unix_sock(new_sock, (void *)&msg, sizeof(msg)); | |
175 | if (ret <= 0) { | |
176 | DBG("Nothing recv() from client... continuing"); | |
177 | ret = close(new_sock); | |
178 | if (ret) { | |
179 | PERROR("close"); | |
180 | } | |
181 | continue; | |
182 | } | |
183 | ||
184 | rcu_thread_online(); | |
185 | ||
186 | memset(&reply, 0, sizeof(reply)); | |
187 | for (i = 0; i < NR_HEALTH_SESSIOND_TYPES; i++) { | |
188 | /* | |
189 | * health_check_state returns 0 if health is | |
190 | * bad. | |
191 | */ | |
192 | if (!health_check_state(health_sessiond, i)) { | |
193 | reply.ret_code |= 1ULL << i; | |
194 | } | |
195 | } | |
196 | ||
197 | DBG2("Health check return value %" PRIx64, reply.ret_code); | |
198 | ||
199 | ret = lttcomm_send_unix_sock(new_sock, (void *) &reply, | |
200 | sizeof(reply)); | |
201 | if (ret < 0) { | |
202 | ERR("Failed to send health data back to client"); | |
203 | } | |
204 | ||
205 | /* End of transmission */ | |
206 | ret = close(new_sock); | |
207 | if (ret) { | |
208 | PERROR("close"); | |
209 | } | |
210 | } | |
211 | ||
212 | exit: | |
213 | error: | |
214 | if (err) { | |
215 | ERR("Health error occurred in %s", __func__); | |
216 | } | |
217 | DBG("Health check thread dying"); | |
218 | unlink(config.health_unix_sock_path.value); | |
219 | if (sock >= 0) { | |
220 | ret = close(sock); | |
221 | if (ret) { | |
222 | PERROR("close"); | |
223 | } | |
224 | } | |
225 | ||
226 | lttng_poll_clean(&events); | |
227 | rcu_unregister_thread(); | |
228 | return NULL; | |
229 | } | |
230 | ||
231 | static bool shutdown_health_management_thread(void *thread_data) | |
232 | { | |
233 | int ret; | |
234 | int pipe_write_fd; | |
235 | struct lttng_pipe *health_quit_pipe = thread_data; | |
236 | ||
237 | pipe_write_fd = lttng_pipe_get_writefd(health_quit_pipe); | |
238 | ret = notify_thread_pipe(pipe_write_fd); | |
239 | if (ret < 0) { | |
240 | ERR("Failed to notify Health management thread's quit pipe"); | |
241 | goto error; | |
242 | } | |
243 | return true; | |
244 | error: | |
245 | return false; | |
246 | } | |
247 | ||
248 | bool launch_health_management_thread(void) | |
249 | { | |
250 | struct lttng_thread *thread; | |
251 | struct lttng_pipe *health_quit_pipe = NULL; | |
252 | ||
253 | health_quit_pipe = lttng_pipe_open(FD_CLOEXEC); | |
254 | if (!health_quit_pipe) { | |
255 | goto error; | |
256 | } | |
257 | ||
258 | thread = lttng_thread_create("Health management", | |
259 | thread_manage_health, | |
260 | shutdown_health_management_thread, | |
261 | cleanup_health_management_thread, | |
262 | health_quit_pipe); | |
263 | if (!thread) { | |
264 | goto error; | |
265 | } | |
266 | lttng_thread_put(thread); | |
267 | return true; | |
268 | error: | |
269 | cleanup_health_management_thread(health_quit_pipe); | |
270 | return false; | |
271 | } |