Add destroy session feature
[lttng-tools.git] / liblttngctl / liblttngctl.c
CommitLineData
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 */
33static int sessiond_socket;
34static char sessiond_sock_path[PATH_MAX];
35
36/* Communication structure to ltt-sessiond */
fac6795d 37static struct lttcomm_session_msg lsm;
aaf97519 38static struct lttcomm_lttng_msg llm;
fac6795d
DG
39
40/* Prototypes */
41static int check_tracing_group(const char *grp_name);
ca95a216
DG
42static int ask_sessiond(enum lttcomm_command_type lct, void **buf);
43static int recv_data_sessiond(void *buf, size_t len);
44static int send_data_sessiond(void);
fac6795d 45static int set_session_daemon_path(void);
fac6795d
DG
46
47/* Variables */
48static char *tracing_group;
49static int connected;
50
51/*
ca95a216 52 * send_data_sessiond
fac6795d 53 *
e065084a 54 * Send lttcomm_session_msg to the session daemon.
fac6795d
DG
55 *
56 * On success, return 0
57 * On error, return error code
58 */
ca95a216 59static int send_data_sessiond(void)
fac6795d
DG
60{
61 int ret;
62
63 if (!connected) {
e065084a
DG
64 ret = -ENOTCONN;
65 goto end;
fac6795d
DG
66 }
67
68 ret = lttcomm_send_unix_sock(sessiond_socket, &lsm, sizeof(lsm));
e065084a
DG
69
70end:
71 return ret;
72}
73
74/*
ca95a216 75 * recv_data_sessiond
e065084a
DG
76 *
77 * Receive data from the sessiond socket.
78 *
79 * On success, return 0
80 * On error, return recv() error code
81 */
ca95a216 82static int recv_data_sessiond(void *buf, size_t len)
e065084a
DG
83{
84 int ret;
85
86 if (!connected) {
87 ret = -ENOTCONN;
88 goto end;
fac6795d
DG
89 }
90
ca95a216 91 ret = lttcomm_recv_unix_sock(sessiond_socket, buf, len);
fac6795d 92 if (ret < 0) {
e065084a 93 goto end;
fac6795d
DG
94 }
95
e065084a 96end:
fac6795d
DG
97 return ret;
98}
99
100/*
ca95a216 101 * ask_sessiond
fac6795d 102 *
ca95a216
DG
103 * Ask the session daemon a specific command
104 * and put the data into buf.
105 *
106 * Return size of data (only payload, not header).
fac6795d 107 */
ca95a216 108static int ask_sessiond(enum lttcomm_command_type lct, void **buf)
fac6795d 109{
ca95a216
DG
110 int ret;
111 size_t size;
112 void *data = NULL;
ca95a216
DG
113
114 lsm.cmd_type = lct;
115
116 /* Send command to session daemon */
117 ret = send_data_sessiond();
118 if (ret < 0) {
119 goto end;
fac6795d
DG
120 }
121
ca95a216
DG
122 /* Get header from data transmission */
123 ret = recv_data_sessiond(&llm, sizeof(llm));
124 if (ret < 0) {
125 goto end;
126 }
fac6795d 127
ca95a216
DG
128 /* Check error code if OK */
129 if (llm.ret_code != LTTCOMM_OK) {
130 ret = -llm.ret_code;
131 goto end;
132 }
fac6795d 133
ca95a216
DG
134 size = llm.size_payload;
135 if (size == 0) {
136 goto end;
fac6795d
DG
137 }
138
ca95a216
DG
139 data = (void*) malloc(size);
140
141 /* Get payload data */
142 ret = recv_data_sessiond(data, size);
fac6795d
DG
143 if (ret < 0) {
144 goto end;
145 }
146
ca95a216
DG
147 *buf = data;
148 ret = size;
fac6795d
DG
149
150end:
ca95a216
DG
151 /* Reset lsm data struct */
152 memset(&lsm, 0, sizeof(lsm));
fac6795d
DG
153 return ret;
154}
155
ca95a216
DG
156/*
157 * lttng_get_readable_code
158 *
159 * Return a human readable string of code
160 */
161const char *lttng_get_readable_code(int code)
162{
163 if (code > -LTTCOMM_OK) {
164 return "Ended with errors";
165 }
166
167 return lttcomm_get_readable_code(code);
168}
169
fac6795d
DG
170/*
171 * lttng_ust_list_apps
172 *
173 * Ask the session daemon for all UST traceable
174 * applications.
175 *
ca95a216
DG
176 * Return the number of pids.
177 * On error, return negative value.
fac6795d 178 */
ca95a216 179int lttng_ust_list_apps(pid_t **pids)
fac6795d 180{
ca95a216 181 int ret;
fac6795d 182
ca95a216 183 ret = ask_sessiond(UST_LIST_APPS, (void**) pids);
fac6795d 184 if (ret < 0) {
ca95a216 185 return ret;
fac6795d
DG
186 }
187
ca95a216 188 return ret / sizeof(pid_t);
fac6795d
DG
189}
190
aaf97519
DG
191/*
192 * lttng_create_session
193 *
194 * Create a brand new session using name. Allocate
195 * the session_id param pointing to the UUID.
196 */
8028d920 197int lttng_create_session(char *name, uuid_t *session_id)
aaf97519
DG
198{
199 int ret;
200 char *uuid;
201
202 strncpy(lsm.session_name, name, sizeof(lsm.session_name));
8028d920 203 lsm.session_name[sizeof(lsm.session_name) - 1] = '\0';
aaf97519
DG
204
205 ret = ask_sessiond(LTTNG_CREATE_SESSION, NULL);
206 if (ret < 0) {
207 goto end;
208 }
209
8028d920 210 uuid_copy(*session_id, llm.session_id);
aaf97519 211
8028d920
DG
212end:
213 return ret;
214}
215
216/*
217 * lttng_destroy_session
218 *
219 * Destroy session using name.
220 */
221int lttng_destroy_session(uuid_t *uuid)
222{
223 int ret;
224
225 uuid_copy(lsm.session_id, *uuid);
226
227 ret = ask_sessiond(LTTNG_DESTROY_SESSION, NULL);
228 if (ret < 0) {
229 goto end;
230 }
aaf97519
DG
231
232end:
233 return ret;
234}
235
57167058
DG
236/*
237 * lttng_list_sessions
238 *
239 * Ask the session daemon for all available sessions.
240 *
ca95a216
DG
241 * Return number of session.
242 * On error, return negative value.
57167058 243 */
ca95a216 244int lttng_list_sessions(struct lttng_session **sessions)
57167058 245{
ca95a216 246 int ret;
57167058 247
ca95a216 248 ret = ask_sessiond(LTTNG_LIST_SESSIONS, (void**) sessions);
57167058 249 if (ret < 0) {
ca95a216 250 return ret;
57167058
DG
251 }
252
ca95a216 253 return ret / sizeof(struct lttng_session);
57167058
DG
254}
255
fac6795d
DG
256/*
257 * lttng_connect_sessiond
258 *
259 * Connect to the LTTng session daemon.
260 * On success, return 0
261 * On error, return a negative value
262 */
263int lttng_connect_sessiond(void)
264{
265 int ret;
266
267 ret = set_session_daemon_path();
268 if (ret < 0) {
269 return ret;
270 }
271
272 /* Connect to the sesssion daemon */
273 ret = lttcomm_connect_unix_sock(sessiond_sock_path);
274 if (ret < 0) {
275 return ret;
276 }
277
278 sessiond_socket = ret;
279 connected = 1;
280
281 return 0;
282}
283
284/*
285 * lttng_set_tracing_group
286 *
287 * Set tracing group variable with name. This function
288 * allocate memory pointed by tracing_group.
289 */
290int lttng_set_tracing_group(const char *name)
291{
292 if (asprintf(&tracing_group, "%s", name) < 0) {
293 return -ENOMEM;
294 }
295
296 return 0;
297}
298
299/*
300 * lttng_check_session_daemon
301 *
302 * Return 0 if a sesssion daemon is available
303 * else return -1
304 */
305int lttng_check_session_daemon(void)
306{
307 int ret;
308
309 ret = set_session_daemon_path();
310 if (ret < 0) {
311 return ret;
312 }
313
314 /* If socket exist, we consider the daemon started */
315 ret = access(sessiond_sock_path, F_OK);
316 if (ret < 0) {
317 return ret;
318 }
319
320 return 0;
321}
322
fac6795d
DG
323/*
324 * set_session_daemon_path
325 *
326 * Set sessiond socket path by putting it in
327 * the global sessiond_sock_path variable.
328 */
329static int set_session_daemon_path(void)
330{
331 int ret;
332
333 /* Are we in the tracing group ? */
334 ret = check_tracing_group(tracing_group);
335 if (ret < 0) {
336 if (sprintf(sessiond_sock_path, DEFAULT_HOME_CLIENT_UNIX_SOCK,
337 getenv("HOME")) < 0) {
338 return -ENOMEM;
339 }
340 } else {
341 strncpy(sessiond_sock_path, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
342 sizeof(DEFAULT_GLOBAL_CLIENT_UNIX_SOCK));
343 }
344
345 return 0;
346}
347
348/*
349 * check_tracing_group
350 *
351 * Check if the specified group name exist.
352 * If yes, 0, else -1
353 */
354static int check_tracing_group(const char *grp_name)
355{
356 struct group *grp_tracing; /* no free(). See getgrnam(3) */
357 gid_t *grp_list;
358 int grp_list_size, grp_id, i;
359 int ret = -1;
360
361 /* Get GID of group 'tracing' */
362 grp_tracing = getgrnam(grp_name);
363 if (grp_tracing == NULL) {
364 /* NULL means not found also. getgrnam(3) */
365 if (errno != 0) {
366 perror("getgrnam");
367 }
368 goto end;
369 }
370
371 /* Get number of supplementary group IDs */
372 grp_list_size = getgroups(0, NULL);
373 if (grp_list_size < 0) {
374 perror("getgroups");
375 goto end;
376 }
377
378 /* Alloc group list of the right size */
379 grp_list = malloc(grp_list_size * sizeof(gid_t));
380 grp_id = getgroups(grp_list_size, grp_list);
381 if (grp_id < -1) {
382 perror("getgroups");
383 goto free_list;
384 }
385
386 for (i = 0; i < grp_list_size; i++) {
387 if (grp_list[i] == grp_tracing->gr_gid) {
388 ret = 0;
389 break;
390 }
391 }
392
393free_list:
394 free(grp_list);
395
396end:
397 return ret;
398}
399
400/*
401 * lib constructor
402 */
403static void __attribute__((constructor)) init()
404{
405 /* Set default session group */
406 lttng_set_tracing_group(DEFAULT_TRACING_GROUP);
407}
This page took 0.042532 seconds and 5 git commands to generate.