Clean some part of the code
[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 */
197int lttng_create_session(char *name, char **session_id)
198{
199 int ret;
200 char *uuid;
201
202 strncpy(lsm.session_name, name, sizeof(lsm.session_name));
203
204 ret = ask_sessiond(LTTNG_CREATE_SESSION, NULL);
205 if (ret < 0) {
206 goto end;
207 }
208
209 /* Allocate UUID string length */
210 uuid = malloc(UUID_STR_LEN);
211
212 strncpy(uuid, llm.session_id, UUID_STR_LEN);
213 *session_id = uuid;
214
215end:
216 return ret;
217}
218
57167058
DG
219/*
220 * lttng_list_sessions
221 *
222 * Ask the session daemon for all available sessions.
223 *
ca95a216
DG
224 * Return number of session.
225 * On error, return negative value.
57167058 226 */
ca95a216 227int lttng_list_sessions(struct lttng_session **sessions)
57167058 228{
ca95a216 229 int ret;
57167058 230
ca95a216 231 ret = ask_sessiond(LTTNG_LIST_SESSIONS, (void**) sessions);
57167058 232 if (ret < 0) {
ca95a216 233 return ret;
57167058
DG
234 }
235
ca95a216 236 return ret / sizeof(struct lttng_session);
57167058
DG
237}
238
fac6795d
DG
239/*
240 * lttng_connect_sessiond
241 *
242 * Connect to the LTTng session daemon.
243 * On success, return 0
244 * On error, return a negative value
245 */
246int lttng_connect_sessiond(void)
247{
248 int ret;
249
250 ret = set_session_daemon_path();
251 if (ret < 0) {
252 return ret;
253 }
254
255 /* Connect to the sesssion daemon */
256 ret = lttcomm_connect_unix_sock(sessiond_sock_path);
257 if (ret < 0) {
258 return ret;
259 }
260
261 sessiond_socket = ret;
262 connected = 1;
263
264 return 0;
265}
266
267/*
268 * lttng_set_tracing_group
269 *
270 * Set tracing group variable with name. This function
271 * allocate memory pointed by tracing_group.
272 */
273int lttng_set_tracing_group(const char *name)
274{
275 if (asprintf(&tracing_group, "%s", name) < 0) {
276 return -ENOMEM;
277 }
278
279 return 0;
280}
281
282/*
283 * lttng_check_session_daemon
284 *
285 * Return 0 if a sesssion daemon is available
286 * else return -1
287 */
288int lttng_check_session_daemon(void)
289{
290 int ret;
291
292 ret = set_session_daemon_path();
293 if (ret < 0) {
294 return ret;
295 }
296
297 /* If socket exist, we consider the daemon started */
298 ret = access(sessiond_sock_path, F_OK);
299 if (ret < 0) {
300 return ret;
301 }
302
303 return 0;
304}
305
fac6795d
DG
306/*
307 * set_session_daemon_path
308 *
309 * Set sessiond socket path by putting it in
310 * the global sessiond_sock_path variable.
311 */
312static int set_session_daemon_path(void)
313{
314 int ret;
315
316 /* Are we in the tracing group ? */
317 ret = check_tracing_group(tracing_group);
318 if (ret < 0) {
319 if (sprintf(sessiond_sock_path, DEFAULT_HOME_CLIENT_UNIX_SOCK,
320 getenv("HOME")) < 0) {
321 return -ENOMEM;
322 }
323 } else {
324 strncpy(sessiond_sock_path, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
325 sizeof(DEFAULT_GLOBAL_CLIENT_UNIX_SOCK));
326 }
327
328 return 0;
329}
330
331/*
332 * check_tracing_group
333 *
334 * Check if the specified group name exist.
335 * If yes, 0, else -1
336 */
337static int check_tracing_group(const char *grp_name)
338{
339 struct group *grp_tracing; /* no free(). See getgrnam(3) */
340 gid_t *grp_list;
341 int grp_list_size, grp_id, i;
342 int ret = -1;
343
344 /* Get GID of group 'tracing' */
345 grp_tracing = getgrnam(grp_name);
346 if (grp_tracing == NULL) {
347 /* NULL means not found also. getgrnam(3) */
348 if (errno != 0) {
349 perror("getgrnam");
350 }
351 goto end;
352 }
353
354 /* Get number of supplementary group IDs */
355 grp_list_size = getgroups(0, NULL);
356 if (grp_list_size < 0) {
357 perror("getgroups");
358 goto end;
359 }
360
361 /* Alloc group list of the right size */
362 grp_list = malloc(grp_list_size * sizeof(gid_t));
363 grp_id = getgroups(grp_list_size, grp_list);
364 if (grp_id < -1) {
365 perror("getgroups");
366 goto free_list;
367 }
368
369 for (i = 0; i < grp_list_size; i++) {
370 if (grp_list[i] == grp_tracing->gr_gid) {
371 ret = 0;
372 break;
373 }
374 }
375
376free_list:
377 free(grp_list);
378
379end:
380 return ret;
381}
382
383/*
384 * lib constructor
385 */
386static void __attribute__((constructor)) init()
387{
388 /* Set default session group */
389 lttng_set_tracing_group(DEFAULT_TRACING_GROUP);
390}
This page took 0.039208 seconds and 5 git commands to generate.