Commit | Line | Data |
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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 modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (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 along | |
15 | * with this program; if not, write to the Free Software Foundation, Inc., | |
16 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
fac6795d DG |
17 | */ |
18 | ||
19 | #define _GNU_SOURCE | |
20 | #include <errno.h> | |
21 | #include <fcntl.h> | |
22 | #include <getopt.h> | |
23 | #include <grp.h> | |
24 | #include <limits.h> | |
25 | #include <stdio.h> | |
26 | #include <stdlib.h> | |
27 | #include <string.h> | |
28 | #include <sys/stat.h> | |
29 | #include <sys/types.h> | |
30 | #include <sys/wait.h> | |
31 | #include <unistd.h> | |
32 | ||
33 | #include <lttng/liblttngctl.h> | |
34 | ||
35 | #include "lttng.h" | |
36 | #include "lttngerr.h" | |
37 | ||
38 | /* Variables */ | |
39 | static char *progname; | |
40 | ||
41 | /* Prototypes */ | |
42 | static int process_client_opt(void); | |
43 | static int process_opt_list_apps(void); | |
57167058 | 44 | static int process_opt_list_sessions(void); |
aaf97519 | 45 | static int process_opt_create_session(void); |
5b8719f5 DG |
46 | static void sighandler(int sig); |
47 | static int set_signal_handler(void); | |
fac6795d DG |
48 | |
49 | /* | |
50 | * start_client | |
51 | * | |
52 | * Process client request from the command line | |
53 | * options. Every tracing action is done by the | |
54 | * liblttngctl API. | |
55 | */ | |
56 | static int process_client_opt(void) | |
57 | { | |
58 | int ret; | |
8028d920 | 59 | uuid_t uuid; |
fac6795d DG |
60 | |
61 | /* Connect to the session daemon */ | |
62 | ret = lttng_connect_sessiond(); | |
63 | if (ret < 0) { | |
fac6795d DG |
64 | goto end; |
65 | } | |
66 | ||
67 | if (opt_list_apps) { | |
68 | ret = process_opt_list_apps(); | |
69 | if (ret < 0) { | |
fac6795d DG |
70 | goto end; |
71 | } | |
72 | } | |
73 | ||
57167058 DG |
74 | if (opt_list_session) { |
75 | ret = process_opt_list_sessions(); | |
76 | if (ret < 0) { | |
77 | goto end; | |
78 | } | |
79 | } | |
80 | ||
aaf97519 DG |
81 | if (opt_create_session != NULL) { |
82 | ret = process_opt_create_session(); | |
83 | if (ret < 0) { | |
84 | goto end; | |
85 | } | |
86 | } | |
87 | ||
8028d920 DG |
88 | if (opt_destroy_session != NULL) { |
89 | uuid_parse(opt_destroy_session, uuid); | |
90 | ret = lttng_destroy_session(&uuid); | |
91 | if (ret < 0) { | |
92 | goto end; | |
93 | } | |
94 | } | |
95 | ||
fac6795d DG |
96 | return 0; |
97 | ||
98 | end: | |
ebafd2a5 | 99 | ERR("%s", lttng_get_readable_code(ret)); |
fac6795d DG |
100 | return ret; |
101 | } | |
102 | ||
aaf97519 DG |
103 | /* |
104 | * process_opt_create_session | |
105 | * | |
106 | * Create a new session using the name pass | |
107 | * to the command line. | |
108 | */ | |
109 | static int process_opt_create_session(void) | |
110 | { | |
111 | int ret; | |
8028d920 DG |
112 | uuid_t session_id; |
113 | char str_uuid[37]; | |
aaf97519 DG |
114 | |
115 | ret = lttng_create_session(opt_create_session, &session_id); | |
116 | if (ret < 0) { | |
117 | goto error; | |
118 | } | |
119 | ||
8028d920 DG |
120 | uuid_unparse(session_id, str_uuid); |
121 | ||
aaf97519 | 122 | MSG("Session created:"); |
8028d920 | 123 | MSG(" %s (%s)", opt_create_session, str_uuid); |
aaf97519 DG |
124 | |
125 | error: | |
126 | return ret; | |
127 | } | |
128 | ||
57167058 DG |
129 | /* |
130 | * process_opt_list_sessions | |
131 | * | |
132 | * Get the list of available sessions from | |
133 | * the session daemon and print it to user. | |
134 | */ | |
135 | static int process_opt_list_sessions(void) | |
136 | { | |
137 | int ret, count, i; | |
138 | struct lttng_session *sess; | |
139 | ||
140 | count = lttng_list_sessions(&sess); | |
141 | if (count < 0) { | |
142 | ret = count; | |
143 | goto error; | |
144 | } | |
145 | ||
146 | MSG("Available sessions [Name (uuid)]:"); | |
147 | for (i = 0; i < count; i++) { | |
148 | MSG("\tName: %s (uuid: %s)", sess[i].name, sess[i].uuid); | |
149 | } | |
150 | ||
151 | free(sess); | |
152 | MSG("\nTo select a session, use --session UUID."); | |
153 | ||
154 | return 0; | |
155 | ||
156 | error: | |
157 | return ret; | |
158 | } | |
159 | ||
fac6795d DG |
160 | /* |
161 | * process_opt_list_apps | |
162 | * | |
163 | * Get the UST traceable pid list and print | |
164 | * them to the user. | |
165 | */ | |
166 | static int process_opt_list_apps(void) | |
167 | { | |
e8f07c63 | 168 | int i, ret, count; |
fac6795d DG |
169 | pid_t *pids; |
170 | FILE *fp; | |
171 | char path[24]; /* Can't go bigger than /proc/65535/cmdline */ | |
172 | char cmdline[PATH_MAX]; | |
173 | ||
e8f07c63 DG |
174 | count = lttng_ust_list_apps(&pids); |
175 | if (count < 0) { | |
176 | ret = count; | |
fac6795d DG |
177 | goto error; |
178 | } | |
179 | ||
180 | MSG("LTTng UST traceable application [name (pid)]:"); | |
e8f07c63 | 181 | for (i=0; i < count; i++) { |
fac6795d DG |
182 | snprintf(path, sizeof(path), "/proc/%d/cmdline", pids[i]); |
183 | fp = fopen(path, "r"); | |
184 | if (fp == NULL) { | |
e8f07c63 | 185 | MSG("\t(not running) (%d)", pids[i]); |
fac6795d DG |
186 | continue; |
187 | } | |
188 | ret = fread(cmdline, 1, sizeof(cmdline), fp); | |
189 | MSG("\t%s (%d)", cmdline, pids[i]); | |
190 | fclose(fp); | |
191 | } | |
192 | ||
e065084a DG |
193 | /* Allocated by lttng_ust_list_apps() */ |
194 | free(pids); | |
195 | ||
fac6795d DG |
196 | return 0; |
197 | ||
198 | error: | |
199 | return ret; | |
200 | } | |
201 | ||
5b8719f5 DG |
202 | /* |
203 | * spawn_sessiond | |
204 | * | |
205 | * Spawn a session daemon by forking and execv. | |
206 | */ | |
207 | static int spawn_sessiond(char *pathname) | |
208 | { | |
209 | int ret = 0; | |
210 | pid_t pid; | |
211 | ||
212 | MSG("Spawning session daemon"); | |
213 | pid = fork(); | |
214 | if (pid == 0) { | |
215 | /* Spawn session daemon and tell | |
216 | * it to signal us when ready. | |
217 | */ | |
75462a81 | 218 | ret = execlp(pathname, "ltt-sessiond", "--sig-parent", "--quiet", NULL); |
5b8719f5 DG |
219 | if (ret < 0) { |
220 | if (errno == ENOENT) { | |
221 | ERR("No session daemon found. Use --sessiond-path."); | |
222 | } else { | |
223 | perror("execlp"); | |
224 | } | |
225 | kill(getppid(), SIGTERM); | |
226 | exit(EXIT_FAILURE); | |
227 | } | |
228 | exit(EXIT_SUCCESS); | |
229 | } else if (pid > 0) { | |
230 | /* Wait for ltt-sessiond to start */ | |
231 | pause(); | |
232 | goto end; | |
233 | } else { | |
234 | perror("fork"); | |
235 | ret = -1; | |
236 | goto end; | |
237 | } | |
238 | ||
239 | end: | |
240 | return ret; | |
241 | } | |
242 | ||
fac6795d DG |
243 | /* |
244 | * check_ltt_sessiond | |
245 | * | |
246 | * Check if the session daemon is available using | |
5b8719f5 DG |
247 | * the liblttngctl API for the check. If not, try to |
248 | * spawn a daemon. | |
fac6795d DG |
249 | */ |
250 | static int check_ltt_sessiond(void) | |
251 | { | |
252 | int ret; | |
5b8719f5 | 253 | char *pathname = NULL; |
fac6795d DG |
254 | |
255 | ret = lttng_check_session_daemon(); | |
256 | if (ret < 0) { | |
5b8719f5 DG |
257 | /* Try command line option path */ |
258 | if (opt_sessiond_path != NULL) { | |
259 | ret = access(opt_sessiond_path, F_OK | X_OK); | |
260 | if (ret < 0) { | |
261 | ERR("No such file: %s", opt_sessiond_path); | |
262 | goto end; | |
263 | } | |
264 | pathname = opt_sessiond_path; | |
265 | } else { | |
266 | /* Try LTTNG_SESSIOND_PATH env variable */ | |
e8f07c63 DG |
267 | pathname = getenv(LTTNG_SESSIOND_PATH_ENV); |
268 | if (pathname != NULL) { | |
269 | /* strdup here in order to make the free() | |
270 | * not fail later on. | |
271 | */ | |
272 | pathname = strdup(pathname); | |
273 | } | |
5b8719f5 DG |
274 | } |
275 | ||
276 | /* Let's rock and roll */ | |
277 | if (pathname == NULL) { | |
278 | ret = asprintf(&pathname, "ltt-sessiond"); | |
279 | if (ret < 0) { | |
280 | goto end; | |
281 | } | |
282 | } | |
283 | ||
284 | ret = spawn_sessiond(pathname); | |
285 | free(pathname); | |
286 | if (ret < 0) { | |
287 | ERR("Problem occurs when starting %s", pathname); | |
288 | goto end; | |
289 | } | |
fac6795d DG |
290 | } |
291 | ||
5b8719f5 | 292 | end: |
fac6795d DG |
293 | return ret; |
294 | } | |
295 | ||
5b8719f5 DG |
296 | /* |
297 | * set_signal_handler | |
298 | * | |
299 | * Setup signal handler for SIGCHLD and SIGTERM. | |
300 | */ | |
301 | static int set_signal_handler(void) | |
302 | { | |
303 | int ret = 0; | |
304 | struct sigaction sa; | |
305 | sigset_t sigset; | |
306 | ||
307 | if ((ret = sigemptyset(&sigset)) < 0) { | |
308 | perror("sigemptyset"); | |
309 | goto end; | |
310 | } | |
311 | ||
312 | sa.sa_handler = sighandler; | |
313 | sa.sa_mask = sigset; | |
314 | sa.sa_flags = 0; | |
315 | if ((ret = sigaction(SIGCHLD, &sa, NULL)) < 0) { | |
316 | perror("sigaction"); | |
317 | goto end; | |
318 | } | |
fac6795d | 319 | |
5b8719f5 DG |
320 | if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) { |
321 | perror("sigaction"); | |
322 | goto end; | |
323 | } | |
324 | ||
325 | end: | |
326 | return ret; | |
327 | } | |
328 | ||
329 | /* | |
330 | * sighandler | |
331 | * | |
332 | * Signal handler for the daemon | |
333 | */ | |
334 | static void sighandler(int sig) | |
335 | { | |
336 | DBG("%d received", sig); | |
337 | switch (sig) { | |
338 | case SIGTERM: | |
339 | clean_exit(EXIT_FAILURE); | |
340 | break; | |
341 | case SIGCHLD: | |
342 | /* Notify is done */ | |
343 | break; | |
344 | default: | |
345 | break; | |
346 | } | |
347 | ||
348 | return; | |
349 | } | |
fac6795d DG |
350 | /* |
351 | * clean_exit | |
352 | */ | |
353 | void clean_exit(int code) | |
354 | { | |
355 | DBG("Clean exit"); | |
356 | exit(code); | |
357 | } | |
358 | ||
359 | /* | |
5b8719f5 | 360 | * main |
fac6795d DG |
361 | */ |
362 | int main(int argc, char *argv[]) | |
363 | { | |
364 | int ret; | |
365 | ||
366 | progname = argv[0] ? argv[0] : "lttng"; | |
367 | ||
368 | /* For Mathieu Desnoyers aka Dr Tracing */ | |
369 | if (strncmp(progname, "drtrace", 7) == 0) { | |
370 | MSG("%c[%d;%dmWelcome back Dr Tracing!%c[%dm\n\n", 27,1,33,27,0); | |
371 | } | |
372 | ||
373 | ret = parse_args(argc, (const char **) argv); | |
374 | if (ret < 0) { | |
375 | return EXIT_FAILURE; | |
376 | } | |
377 | ||
5b8719f5 DG |
378 | ret = set_signal_handler(); |
379 | if (ret < 0) { | |
380 | return ret; | |
381 | } | |
382 | ||
fac6795d DG |
383 | if (opt_tracing_group != NULL) { |
384 | DBG("Set tracing group to '%s'", opt_tracing_group); | |
385 | lttng_set_tracing_group(opt_tracing_group); | |
386 | } | |
387 | ||
388 | /* If ask for kernel tracing, need root perms */ | |
389 | if (opt_trace_kernel) { | |
390 | DBG("Kernel tracing activated"); | |
391 | if (getuid() != 0) { | |
392 | ERR("%s must be setuid root", progname); | |
393 | return -EPERM; | |
394 | } | |
395 | } | |
396 | ||
397 | /* Check if the lttng session daemon is running. | |
398 | * If no, a daemon will be spawned. | |
399 | */ | |
5b8719f5 | 400 | if (opt_no_sessiond == 0 && (check_ltt_sessiond() < 0)) { |
fac6795d DG |
401 | return EXIT_FAILURE; |
402 | } | |
403 | ||
404 | ret = process_client_opt(); | |
405 | if (ret < 0) { | |
406 | return ret; | |
407 | } | |
408 | ||
409 | return 0; | |
410 | } |