Commit | Line | Data |
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2691221a MD |
1 | /* |
2 | * lttng-ust-comm.c | |
3 | * | |
4 | * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca> | |
5 | * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
6 | * | |
7 | * This library is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU Lesser General Public | |
9 | * License as published by the Free Software Foundation; only | |
10 | * version 2.1 of the License. | |
11 | * | |
12 | * This library is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * Lesser General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU Lesser General Public | |
18 | * License along with this library; if not, write to the Free Software | |
19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | */ | |
21 | ||
22 | #include <sys/types.h> | |
23 | #include <sys/socket.h> | |
24 | #include <unistd.h> | |
25 | #include <errno.h> | |
b35d179d MD |
26 | #include <ust/lttng-ust-abi.h> |
27 | #include <lttng-ust-comm.h> | |
2691221a | 28 | #include <ust/usterr-signal-safe.h> |
d9e99d10 | 29 | #include <pthread.h> |
1ea11eab MD |
30 | #include <assert.h> |
31 | ||
32 | /* | |
33 | * communication thread mutex. Held when handling a command, also held | |
34 | * by fork() to deal with removal of threads, and by exit path. | |
35 | */ | |
36 | static pthread_mutex_t lttng_ust_comm_mutex = PTHREAD_MUTEX_INITIALIZER; | |
37 | ||
38 | /* Should the ust comm thread quit ? */ | |
39 | static int lttng_ust_comm_should_quit; | |
40 | ||
41 | /* | |
42 | * Info about socket and associated listener thread. | |
43 | */ | |
44 | struct sock_info { | |
45 | char sock_path[PATH_MAX]; | |
46 | int socket; | |
47 | pthread_t ust_listener; /* listener thread */ | |
48 | }; | |
2691221a MD |
49 | |
50 | /* Socket from app (connect) to session daemon (listen) for communication */ | |
1ea11eab MD |
51 | struct sock_info global_apps = { |
52 | .sock_path = DEFAULT_GLOBAL_APPS_UNIX_SOCK, | |
53 | .socket = -1, | |
54 | }; | |
2691221a MD |
55 | |
56 | /* TODO: allow global_apps_sock_path override */ | |
57 | ||
1ea11eab MD |
58 | struct sock_info local_apps = { |
59 | .socket = -1, | |
60 | }; | |
2691221a MD |
61 | |
62 | static | |
9eb62b9c | 63 | int setup_local_apps_socket(void) |
2691221a MD |
64 | { |
65 | const char *home_dir; | |
2691221a MD |
66 | |
67 | home_dir = (const char *) getenv("HOME"); | |
68 | if (!home_dir) | |
69 | return -ENOENT; | |
1ea11eab | 70 | snprintf(local_apps.sock_path, PATH_MAX, |
2691221a | 71 | DEFAULT_HOME_APPS_UNIX_SOCK, home_dir); |
2691221a MD |
72 | return 0; |
73 | } | |
74 | ||
75 | static | |
76 | int register_app_to_sessiond(int socket) | |
77 | { | |
78 | ssize_t ret; | |
79 | struct { | |
e44418f3 MD |
80 | uint32_t major; |
81 | uint32_t minor; | |
2691221a MD |
82 | pid_t pid; |
83 | uid_t uid; | |
84 | } reg_msg; | |
85 | ||
e44418f3 MD |
86 | reg_msg.major = LTTNG_UST_COMM_VERSION_MAJOR; |
87 | reg_msg.minor = LTTNG_UST_COMM_VERSION_MINOR; | |
2691221a MD |
88 | reg_msg.pid = getpid(); |
89 | reg_msg.uid = getuid(); | |
90 | ||
91 | ret = lttcomm_send_unix_sock(socket, ®_msg, sizeof(reg_msg)); | |
92 | if (ret >= 0 && ret != sizeof(reg_msg)) | |
93 | return -EIO; | |
94 | return ret; | |
95 | } | |
96 | ||
d9e99d10 | 97 | static |
d3a492d1 | 98 | int send_reply(int sock, struct lttcomm_ust_reply *lur) |
d9e99d10 | 99 | { |
9eb62b9c | 100 | ssize_t len; |
d3a492d1 MD |
101 | |
102 | len = lttcomm_send_unix_sock(sock, &lur, sizeof(lur)); | |
103 | switch (len) { | |
104 | case sizeof(lur): | |
105 | DBG("message successfully sent"); | |
106 | return 0; | |
107 | case -1: | |
108 | if (errno == ECONNRESET) { | |
109 | printf("remote end closed connection\n"); | |
110 | return 0; | |
111 | } | |
112 | return -1; | |
113 | default: | |
114 | printf("incorrect message size: %zd\n", len); | |
115 | return -1; | |
116 | } | |
117 | } | |
118 | ||
119 | static | |
120 | int handle_message(int sock, struct lttcomm_ust_msg *lum) | |
121 | { | |
1ea11eab MD |
122 | int ret = 0; |
123 | ||
124 | pthread_mutex_lock(<tng_ust_comm_mutex); | |
125 | ||
126 | if (lttng_ust_comm_should_quit) { | |
127 | ret = 0; | |
128 | goto end; | |
129 | } | |
9eb62b9c | 130 | |
e7723462 | 131 | switch (lum->cmd_type) { |
b35d179d | 132 | case UST_CREATE_SESSION: |
9eb62b9c | 133 | { |
e7723462 | 134 | struct lttcomm_ust_reply lur; |
d9e99d10 | 135 | |
9eb62b9c MD |
136 | DBG("Handling create session message"); |
137 | memset(&lur, 0, sizeof(lur)); | |
b35d179d | 138 | lur.cmd_type = UST_CREATE_SESSION; |
1ea11eab MD |
139 | ret = lttng_abi_create_session(); |
140 | if (ret >= 0) { | |
141 | lur.ret_val = ret; | |
9eb62b9c | 142 | lur.ret_code = LTTCOMM_OK; |
1ea11eab | 143 | } else { |
9eb62b9c | 144 | lur.ret_code = LTTCOMM_SESSION_FAIL; |
1ea11eab | 145 | } |
d3a492d1 | 146 | ret = send_reply(sock, &lur); |
1ea11eab MD |
147 | break; |
148 | } | |
149 | case UST_RELEASE: | |
150 | { | |
151 | struct lttcomm_ust_reply lur; | |
152 | ||
153 | DBG("Handling release message, handle: %d", | |
154 | lum->handle); | |
155 | memset(&lur, 0, sizeof(lur)); | |
156 | lur.cmd_type = UST_RELEASE; | |
1ea11eab MD |
157 | ret = objd_unref(lum->handle); |
158 | if (!ret) { | |
159 | lur.ret_code = LTTCOMM_OK; | |
160 | } else { | |
161 | lur.ret_code = LTTCOMM_ERR; | |
162 | } | |
d3a492d1 | 163 | ret = send_reply(sock, &lur); |
d9e99d10 | 164 | break; |
9eb62b9c | 165 | } |
d9e99d10 | 166 | default: |
e7723462 | 167 | ERR("Unimplemented command %d", (int) lum->cmd_type); |
1ea11eab MD |
168 | ret = -1; |
169 | goto end; | |
d9e99d10 | 170 | } |
1ea11eab MD |
171 | end: |
172 | pthread_mutex_unlock(<tng_ust_comm_mutex); | |
173 | return ret; | |
d9e99d10 MD |
174 | } |
175 | ||
1ea11eab MD |
176 | /* |
177 | * This thread does not allocate any resource, except within | |
178 | * handle_message, within mutex protection. This mutex protects against | |
179 | * fork and exit. | |
180 | * The other moment it allocates resources is at socket connexion, which | |
181 | * is also protected by the mutex. | |
182 | */ | |
d9e99d10 MD |
183 | static |
184 | void *ust_listener_thread(void *arg) | |
185 | { | |
1ea11eab MD |
186 | struct sock_info *sock_info = arg; |
187 | int sock, ret; | |
d9e99d10 | 188 | |
9eb62b9c MD |
189 | /* Restart trying to connect to the session daemon */ |
190 | restart: | |
1ea11eab MD |
191 | pthread_mutex_lock(<tng_ust_comm_mutex); |
192 | ||
193 | if (lttng_ust_comm_should_quit) { | |
194 | pthread_mutex_unlock(<tng_ust_comm_mutex); | |
195 | goto quit; | |
196 | } | |
9eb62b9c | 197 | |
1ea11eab MD |
198 | if (sock_info->socket != -1) { |
199 | ret = close(sock_info->socket); | |
200 | if (ret) { | |
201 | ERR("Error closing local apps socket"); | |
202 | } | |
203 | sock_info->socket = -1; | |
204 | } | |
9eb62b9c MD |
205 | /* Check for sessiond availability with pipe TODO */ |
206 | ||
207 | /* Register */ | |
1ea11eab | 208 | ret = lttcomm_connect_unix_sock(sock_info->sock_path); |
9eb62b9c MD |
209 | if (ret < 0) { |
210 | ERR("Error connecting to global apps socket"); | |
1ea11eab | 211 | pthread_mutex_unlock(<tng_ust_comm_mutex); |
4eef2998 | 212 | sleep(5); |
1ea11eab MD |
213 | goto restart; |
214 | } else { | |
215 | sock_info->socket = sock = ret; | |
216 | pthread_mutex_unlock(<tng_ust_comm_mutex); | |
9eb62b9c | 217 | } |
1ea11eab | 218 | |
9eb62b9c MD |
219 | ret = register_app_to_sessiond(sock); |
220 | if (ret < 0) { | |
221 | ERR("Error registering app to local apps socket"); | |
222 | sleep(5); | |
223 | goto restart; | |
224 | } | |
d9e99d10 MD |
225 | for (;;) { |
226 | ssize_t len; | |
e7723462 | 227 | struct lttcomm_ust_msg lum; |
d9e99d10 MD |
228 | |
229 | /* Receive session handle */ | |
e7723462 | 230 | len = lttcomm_recv_unix_sock(sock, &lum, sizeof(lum)); |
d9e99d10 MD |
231 | switch (len) { |
232 | case 0: /* orderly shutdown */ | |
233 | DBG("ltt-sessiond has performed an orderly shutdown\n"); | |
234 | goto end; | |
e7723462 | 235 | case sizeof(lum): |
d9e99d10 | 236 | DBG("message received\n"); |
e7723462 | 237 | ret = handle_message(sock, &lum); |
2a80c9d8 | 238 | if (ret < 0) { |
9eb62b9c | 239 | ERR("Error handling message\n"); |
d9e99d10 MD |
240 | } |
241 | continue; | |
242 | case -1: | |
243 | if (errno == ECONNRESET) { | |
244 | ERR("remote end closed connection\n"); | |
245 | goto end; | |
246 | } | |
247 | goto end; | |
248 | default: | |
249 | ERR("incorrect message size: %zd\n", len); | |
250 | continue; | |
251 | } | |
252 | ||
253 | } | |
254 | end: | |
9eb62b9c | 255 | goto restart; /* try to reconnect */ |
1ea11eab | 256 | quit: |
d9e99d10 MD |
257 | return NULL; |
258 | } | |
259 | ||
260 | ||
2691221a MD |
261 | /* |
262 | * sessiond monitoring thread: monitor presence of global and per-user | |
263 | * sessiond by polling the application common named pipe. | |
264 | */ | |
265 | /* TODO */ | |
266 | ||
267 | void __attribute__((constructor)) lttng_ust_comm_init(void) | |
268 | { | |
269 | int ret; | |
270 | ||
271 | init_usterr(); | |
272 | ||
9eb62b9c | 273 | ret = setup_local_apps_socket(); |
2691221a | 274 | if (ret) { |
9eb62b9c | 275 | ERR("Error setting up to local apps socket"); |
2691221a | 276 | } |
9eb62b9c | 277 | #if 0 |
1ea11eab MD |
278 | ret = pthread_create(&global_apps.ust_listener, NULL, |
279 | ust_listener_thread, &global_apps); | |
9eb62b9c | 280 | #endif //0 |
1ea11eab MD |
281 | ret = pthread_create(&local_apps.ust_listener, NULL, |
282 | ust_listener_thread, &local_apps); | |
2691221a MD |
283 | } |
284 | ||
285 | void __attribute__((destructor)) lttng_ust_comm_exit(void) | |
286 | { | |
287 | int ret; | |
288 | ||
9eb62b9c MD |
289 | /* |
290 | * Using pthread_cancel here because: | |
291 | * A) we don't want to hang application teardown. | |
292 | * B) the thread is not allocating any resource. | |
293 | */ | |
1ea11eab MD |
294 | |
295 | /* | |
296 | * Require the communication thread to quit. Synchronize with | |
297 | * mutexes to ensure it is not in a mutex critical section when | |
298 | * pthread_cancel is later called. | |
299 | */ | |
300 | pthread_mutex_lock(<tng_ust_comm_mutex); | |
301 | lttng_ust_comm_should_quit = 1; | |
302 | pthread_mutex_unlock(<tng_ust_comm_mutex); | |
303 | ||
304 | #if 0 | |
305 | ret = pthread_cancel(global_apps.ust_listener); | |
9eb62b9c MD |
306 | if (ret) { |
307 | ERR("Error cancelling global ust listener thread"); | |
2691221a | 308 | } |
1ea11eab MD |
309 | #endif //0 |
310 | if (global_apps.socket != -1) { | |
311 | ret = close(global_apps.socket); | |
312 | assert(!ret); | |
313 | } | |
314 | ||
315 | ret = pthread_cancel(local_apps.ust_listener); | |
9eb62b9c MD |
316 | if (ret) { |
317 | ERR("Error cancelling local ust listener thread"); | |
2691221a | 318 | } |
1ea11eab MD |
319 | |
320 | if (local_apps.socket != -1) { | |
321 | ret = close(local_apps.socket); | |
322 | assert(!ret); | |
323 | } | |
324 | ||
b35d179d | 325 | lttng_ust_abi_exit(); |
1ea11eab | 326 | ltt_events_exit(); |
2691221a | 327 | } |