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826d496d MD |
1 | /* |
2 | * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca> | |
fac6795d DG |
3 | * |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version 2 | |
7 | * of the License, or (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
fac6795d DG |
17 | */ |
18 | ||
19 | #define _GNU_SOURCE | |
20 | #include <errno.h> | |
21 | #include <grp.h> | |
22 | #include <stdio.h> | |
23 | #include <stdlib.h> | |
24 | #include <string.h> | |
25 | #include <unistd.h> | |
26 | ||
27 | #include <lttng/liblttngctl.h> | |
28 | ||
29 | #include "liblttsessiondcomm.h" | |
30 | #include "lttngerr.h" | |
31 | ||
32 | /* Socket to session daemon for communication */ | |
33 | static int sessiond_socket; | |
34 | static char sessiond_sock_path[PATH_MAX]; | |
35 | ||
36 | /* Communication structure to ltt-sessiond */ | |
37 | static struct lttcomm_lttng_msg llm; | |
38 | static struct lttcomm_session_msg lsm; | |
39 | ||
40 | /* Prototypes */ | |
41 | static int check_tracing_group(const char *grp_name); | |
42 | static int ask_sessiond(void); | |
e065084a | 43 | static int recvfrom_sessiond(void); |
fac6795d DG |
44 | static int set_session_daemon_path(void); |
45 | static void reset_data_struct(void); | |
46 | ||
47 | int lttng_connect_sessiond(void); | |
48 | int lttng_create_session(const char *name, char *session_id); | |
49 | int lttng_check_session_daemon(void); | |
50 | ||
51 | /* Variables */ | |
52 | static char *tracing_group; | |
53 | static int connected; | |
54 | ||
55 | /* | |
56 | * ask_sessiond | |
57 | * | |
e065084a | 58 | * Send lttcomm_session_msg to the session daemon. |
fac6795d DG |
59 | * |
60 | * On success, return 0 | |
61 | * On error, return error code | |
62 | */ | |
63 | static int ask_sessiond(void) | |
64 | { | |
65 | int ret; | |
66 | ||
67 | if (!connected) { | |
e065084a DG |
68 | ret = -ENOTCONN; |
69 | goto end; | |
fac6795d DG |
70 | } |
71 | ||
72 | ret = lttcomm_send_unix_sock(sessiond_socket, &lsm, sizeof(lsm)); | |
e065084a DG |
73 | |
74 | end: | |
75 | return ret; | |
76 | } | |
77 | ||
78 | /* | |
79 | * recvfrom_sessiond | |
80 | * | |
81 | * Receive data from the sessiond socket. | |
82 | * | |
83 | * On success, return 0 | |
84 | * On error, return recv() error code | |
85 | */ | |
86 | static int recvfrom_sessiond(void) | |
87 | { | |
88 | int ret; | |
89 | ||
90 | if (!connected) { | |
91 | ret = -ENOTCONN; | |
92 | goto end; | |
fac6795d DG |
93 | } |
94 | ||
95 | ret = lttcomm_recv_unix_sock(sessiond_socket, &llm, sizeof(llm)); | |
96 | if (ret < 0) { | |
e065084a | 97 | goto end; |
fac6795d DG |
98 | } |
99 | ||
100 | /* Check return code */ | |
101 | if (llm.ret_code != LTTCOMM_OK) { | |
102 | ret = -llm.ret_code; | |
e065084a | 103 | goto end; |
fac6795d DG |
104 | } |
105 | ||
e065084a | 106 | end: |
fac6795d DG |
107 | return ret; |
108 | } | |
109 | ||
110 | /* | |
111 | * lttng_get_readable_code | |
112 | * | |
113 | * Return a human readable string of code | |
114 | */ | |
115 | const char *lttng_get_readable_code(int code) | |
116 | { | |
117 | if (code > -LTTCOMM_OK) { | |
118 | return "Ended with errors"; | |
119 | } | |
120 | ||
121 | return lttcomm_get_readable_code(code); | |
122 | } | |
123 | ||
124 | /* | |
125 | * lttng_create_session | |
126 | * | |
127 | * Create a tracing session using "name" to the session daemon. | |
128 | * If no name is given, the auto session creation is set and | |
129 | * the daemon will take care of finding a name. | |
130 | * | |
131 | * On success, return 0 and session_id point to the uuid str. | |
132 | * On error, negative value is returned. | |
133 | */ | |
134 | int lttng_create_session(const char *name, char *session_id) | |
135 | { | |
136 | int ret; | |
137 | ||
138 | lsm.cmd_type = LTTNG_CREATE_SESSION; | |
139 | if (name == NULL) { | |
140 | lsm.u.create_session.auto_session = 1; | |
141 | } else { | |
142 | strncpy(lsm.session_name, name, strlen(name)); | |
143 | lsm.u.create_session.auto_session = 0; | |
144 | } | |
145 | ||
146 | /* Ask the session daemon */ | |
147 | ret = ask_sessiond(); | |
148 | if (ret < 0) { | |
149 | goto end; | |
150 | } | |
151 | ||
152 | /* Unparse session ID */ | |
153 | uuid_unparse(llm.session_id, session_id); | |
154 | ||
155 | end: | |
156 | reset_data_struct(); | |
157 | ||
158 | return ret; | |
159 | } | |
160 | ||
161 | /* | |
162 | * lttng_ust_list_apps | |
163 | * | |
164 | * Ask the session daemon for all UST traceable | |
165 | * applications. | |
166 | * | |
167 | * Return the size of pids. | |
168 | */ | |
169 | size_t lttng_ust_list_apps(pid_t **pids) | |
170 | { | |
e065084a DG |
171 | int ret, first = 0; |
172 | size_t size = 0; | |
173 | pid_t *p = NULL; | |
fac6795d DG |
174 | |
175 | lsm.cmd_type = UST_LIST_APPS; | |
176 | ||
177 | ret = ask_sessiond(); | |
178 | if (ret < 0) { | |
179 | goto error; | |
180 | } | |
181 | ||
e065084a DG |
182 | do { |
183 | ret = recvfrom_sessiond(); | |
184 | if (ret < 0) { | |
185 | goto error; | |
186 | } | |
187 | ||
188 | if (first == 0) { | |
189 | first = 1; | |
190 | size = llm.num_pckt; | |
191 | p = malloc(sizeof(pid_t) * size); | |
192 | } | |
193 | p[size - llm.num_pckt] = llm.u.list_apps.pid; | |
194 | } while ((llm.num_pckt-1) != 0); | |
195 | ||
196 | *pids = p; | |
fac6795d | 197 | |
e065084a | 198 | return size; |
fac6795d DG |
199 | |
200 | error: | |
201 | return ret; | |
202 | } | |
203 | ||
204 | /* | |
205 | * lttng_connect_sessiond | |
206 | * | |
207 | * Connect to the LTTng session daemon. | |
208 | * On success, return 0 | |
209 | * On error, return a negative value | |
210 | */ | |
211 | int lttng_connect_sessiond(void) | |
212 | { | |
213 | int ret; | |
214 | ||
215 | ret = set_session_daemon_path(); | |
216 | if (ret < 0) { | |
217 | return ret; | |
218 | } | |
219 | ||
220 | /* Connect to the sesssion daemon */ | |
221 | ret = lttcomm_connect_unix_sock(sessiond_sock_path); | |
222 | if (ret < 0) { | |
223 | return ret; | |
224 | } | |
225 | ||
226 | sessiond_socket = ret; | |
227 | connected = 1; | |
228 | ||
229 | return 0; | |
230 | } | |
231 | ||
232 | /* | |
233 | * lttng_set_tracing_group | |
234 | * | |
235 | * Set tracing group variable with name. This function | |
236 | * allocate memory pointed by tracing_group. | |
237 | */ | |
238 | int lttng_set_tracing_group(const char *name) | |
239 | { | |
240 | if (asprintf(&tracing_group, "%s", name) < 0) { | |
241 | return -ENOMEM; | |
242 | } | |
243 | ||
244 | return 0; | |
245 | } | |
246 | ||
247 | /* | |
248 | * lttng_check_session_daemon | |
249 | * | |
250 | * Return 0 if a sesssion daemon is available | |
251 | * else return -1 | |
252 | */ | |
253 | int lttng_check_session_daemon(void) | |
254 | { | |
255 | int ret; | |
256 | ||
257 | ret = set_session_daemon_path(); | |
258 | if (ret < 0) { | |
259 | return ret; | |
260 | } | |
261 | ||
262 | /* If socket exist, we consider the daemon started */ | |
263 | ret = access(sessiond_sock_path, F_OK); | |
264 | if (ret < 0) { | |
265 | return ret; | |
266 | } | |
267 | ||
268 | return 0; | |
269 | } | |
270 | ||
271 | /* | |
272 | * reset_data_struct | |
273 | * | |
274 | * Reset session daemon structures. | |
275 | */ | |
276 | static void reset_data_struct(void) | |
277 | { | |
278 | memset(&lsm, 0, sizeof(lsm)); | |
279 | memset(&llm, 0, sizeof(llm)); | |
280 | } | |
281 | ||
282 | /* | |
283 | * set_session_daemon_path | |
284 | * | |
285 | * Set sessiond socket path by putting it in | |
286 | * the global sessiond_sock_path variable. | |
287 | */ | |
288 | static int set_session_daemon_path(void) | |
289 | { | |
290 | int ret; | |
291 | ||
292 | /* Are we in the tracing group ? */ | |
293 | ret = check_tracing_group(tracing_group); | |
294 | if (ret < 0) { | |
295 | if (sprintf(sessiond_sock_path, DEFAULT_HOME_CLIENT_UNIX_SOCK, | |
296 | getenv("HOME")) < 0) { | |
297 | return -ENOMEM; | |
298 | } | |
299 | } else { | |
300 | strncpy(sessiond_sock_path, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK, | |
301 | sizeof(DEFAULT_GLOBAL_CLIENT_UNIX_SOCK)); | |
302 | } | |
303 | ||
304 | return 0; | |
305 | } | |
306 | ||
307 | /* | |
308 | * check_tracing_group | |
309 | * | |
310 | * Check if the specified group name exist. | |
311 | * If yes, 0, else -1 | |
312 | */ | |
313 | static int check_tracing_group(const char *grp_name) | |
314 | { | |
315 | struct group *grp_tracing; /* no free(). See getgrnam(3) */ | |
316 | gid_t *grp_list; | |
317 | int grp_list_size, grp_id, i; | |
318 | int ret = -1; | |
319 | ||
320 | /* Get GID of group 'tracing' */ | |
321 | grp_tracing = getgrnam(grp_name); | |
322 | if (grp_tracing == NULL) { | |
323 | /* NULL means not found also. getgrnam(3) */ | |
324 | if (errno != 0) { | |
325 | perror("getgrnam"); | |
326 | } | |
327 | goto end; | |
328 | } | |
329 | ||
330 | /* Get number of supplementary group IDs */ | |
331 | grp_list_size = getgroups(0, NULL); | |
332 | if (grp_list_size < 0) { | |
333 | perror("getgroups"); | |
334 | goto end; | |
335 | } | |
336 | ||
337 | /* Alloc group list of the right size */ | |
338 | grp_list = malloc(grp_list_size * sizeof(gid_t)); | |
339 | grp_id = getgroups(grp_list_size, grp_list); | |
340 | if (grp_id < -1) { | |
341 | perror("getgroups"); | |
342 | goto free_list; | |
343 | } | |
344 | ||
345 | for (i = 0; i < grp_list_size; i++) { | |
346 | if (grp_list[i] == grp_tracing->gr_gid) { | |
347 | ret = 0; | |
348 | break; | |
349 | } | |
350 | } | |
351 | ||
352 | free_list: | |
353 | free(grp_list); | |
354 | ||
355 | end: | |
356 | return ret; | |
357 | } | |
358 | ||
359 | /* | |
360 | * lib constructor | |
361 | */ | |
362 | static void __attribute__((constructor)) init() | |
363 | { | |
364 | /* Set default session group */ | |
365 | lttng_set_tracing_group(DEFAULT_TRACING_GROUP); | |
366 | } |