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); | |
1c9f7941 | 48 | static int get_cmdline_by_pid(pid_t pid, char **cmdline); |
8548ff30 | 49 | static int validate_options(void); |
fac6795d DG |
50 | |
51 | /* | |
52 | * start_client | |
53 | * | |
54 | * Process client request from the command line | |
55 | * options. Every tracing action is done by the | |
56 | * liblttngctl API. | |
57 | */ | |
58 | static int process_client_opt(void) | |
59 | { | |
60 | int ret; | |
8028d920 | 61 | uuid_t uuid; |
fac6795d DG |
62 | |
63 | /* Connect to the session daemon */ | |
64 | ret = lttng_connect_sessiond(); | |
65 | if (ret < 0) { | |
fac6795d DG |
66 | goto end; |
67 | } | |
68 | ||
69 | if (opt_list_apps) { | |
70 | ret = process_opt_list_apps(); | |
71 | if (ret < 0) { | |
fac6795d DG |
72 | goto end; |
73 | } | |
74 | } | |
75 | ||
57167058 DG |
76 | if (opt_list_session) { |
77 | ret = process_opt_list_sessions(); | |
78 | if (ret < 0) { | |
79 | goto end; | |
80 | } | |
81 | } | |
82 | ||
aaf97519 DG |
83 | if (opt_create_session != NULL) { |
84 | ret = process_opt_create_session(); | |
85 | if (ret < 0) { | |
86 | goto end; | |
87 | } | |
88 | } | |
89 | ||
8028d920 DG |
90 | if (opt_destroy_session != NULL) { |
91 | uuid_parse(opt_destroy_session, uuid); | |
92 | ret = lttng_destroy_session(&uuid); | |
93 | if (ret < 0) { | |
94 | goto end; | |
95 | } | |
96 | } | |
97 | ||
e8be5f4f DG |
98 | if (opt_session_uuid != NULL) { |
99 | lttng_set_current_session_uuid(opt_session_uuid); | |
100 | } | |
101 | ||
df0da139 DG |
102 | if (opt_create_trace) { |
103 | DBG("Create trace for pid %d", opt_create_trace); | |
104 | ret = lttng_ust_create_trace(opt_create_trace); | |
105 | if (ret < 0) { | |
106 | goto end; | |
107 | } | |
8548ff30 | 108 | MSG("Trace created successfully!\nUse --start PID to start tracing."); |
df0da139 DG |
109 | } |
110 | ||
fac6795d DG |
111 | return 0; |
112 | ||
113 | end: | |
ebafd2a5 | 114 | ERR("%s", lttng_get_readable_code(ret)); |
fac6795d DG |
115 | return ret; |
116 | } | |
117 | ||
aaf97519 DG |
118 | /* |
119 | * process_opt_create_session | |
120 | * | |
121 | * Create a new session using the name pass | |
122 | * to the command line. | |
123 | */ | |
124 | static int process_opt_create_session(void) | |
125 | { | |
126 | int ret; | |
8028d920 DG |
127 | uuid_t session_id; |
128 | char str_uuid[37]; | |
aaf97519 DG |
129 | |
130 | ret = lttng_create_session(opt_create_session, &session_id); | |
131 | if (ret < 0) { | |
132 | goto error; | |
133 | } | |
134 | ||
8028d920 DG |
135 | uuid_unparse(session_id, str_uuid); |
136 | ||
aaf97519 | 137 | MSG("Session created:"); |
8028d920 | 138 | MSG(" %s (%s)", opt_create_session, str_uuid); |
aaf97519 DG |
139 | |
140 | error: | |
141 | return ret; | |
142 | } | |
143 | ||
57167058 DG |
144 | /* |
145 | * process_opt_list_sessions | |
146 | * | |
147 | * Get the list of available sessions from | |
148 | * the session daemon and print it to user. | |
149 | */ | |
150 | static int process_opt_list_sessions(void) | |
151 | { | |
152 | int ret, count, i; | |
153 | struct lttng_session *sess; | |
154 | ||
155 | count = lttng_list_sessions(&sess); | |
156 | if (count < 0) { | |
157 | ret = count; | |
158 | goto error; | |
159 | } | |
160 | ||
161 | MSG("Available sessions [Name (uuid)]:"); | |
162 | for (i = 0; i < count; i++) { | |
163 | MSG("\tName: %s (uuid: %s)", sess[i].name, sess[i].uuid); | |
164 | } | |
165 | ||
166 | free(sess); | |
167 | MSG("\nTo select a session, use --session UUID."); | |
168 | ||
169 | return 0; | |
170 | ||
171 | error: | |
172 | return ret; | |
173 | } | |
174 | ||
fac6795d DG |
175 | /* |
176 | * process_opt_list_apps | |
177 | * | |
178 | * Get the UST traceable pid list and print | |
179 | * them to the user. | |
180 | */ | |
181 | static int process_opt_list_apps(void) | |
182 | { | |
e8f07c63 | 183 | int i, ret, count; |
fac6795d | 184 | pid_t *pids; |
1c9f7941 | 185 | char *cmdline; |
fac6795d | 186 | |
e8f07c63 DG |
187 | count = lttng_ust_list_apps(&pids); |
188 | if (count < 0) { | |
189 | ret = count; | |
fac6795d DG |
190 | goto error; |
191 | } | |
192 | ||
193 | MSG("LTTng UST traceable application [name (pid)]:"); | |
e8f07c63 | 194 | for (i=0; i < count; i++) { |
1c9f7941 DG |
195 | ret = get_cmdline_by_pid(pids[i], &cmdline); |
196 | if (!ret) { | |
e8f07c63 | 197 | MSG("\t(not running) (%d)", pids[i]); |
fac6795d DG |
198 | continue; |
199 | } | |
fac6795d | 200 | MSG("\t%s (%d)", cmdline, pids[i]); |
1c9f7941 | 201 | free(cmdline); |
fac6795d DG |
202 | } |
203 | ||
e065084a DG |
204 | /* Allocated by lttng_ust_list_apps() */ |
205 | free(pids); | |
206 | ||
fac6795d DG |
207 | return 0; |
208 | ||
209 | error: | |
210 | return ret; | |
211 | } | |
212 | ||
1c9f7941 DG |
213 | /* |
214 | * get_cmdline_by_pid | |
215 | * | |
216 | * Get command line from /proc for a | |
217 | * specific pid. Allocate cmdline so the | |
218 | * user must free() that pointer. | |
219 | * | |
220 | * On success, return 1 | |
221 | * On error (not found), return 0 | |
222 | */ | |
223 | static int get_cmdline_by_pid(pid_t pid, char **cmdline) | |
224 | { | |
225 | int ret; | |
226 | FILE *fp; | |
227 | char path[24]; /* Can't go bigger than /proc/65535/cmdline */ | |
228 | ||
229 | snprintf(path, sizeof(path), "/proc/%d/cmdline", pid); | |
230 | fp = fopen(path, "r"); | |
231 | if (fp == NULL) { | |
232 | goto not_running; | |
233 | } | |
234 | ||
235 | /* Caller must free() *cmdline */ | |
236 | *cmdline = malloc(PATH_MAX); | |
237 | ret = fread(*cmdline, 1, PATH_MAX, fp); | |
238 | fclose(fp); | |
239 | ||
240 | return 1; | |
241 | ||
242 | not_running: | |
243 | return 0; | |
244 | } | |
245 | ||
8548ff30 DG |
246 | /* |
247 | * validate_options | |
248 | * | |
249 | * Make sure that all options passed to the command line | |
250 | * are compatible with each others. | |
251 | * | |
252 | * On error, return -1 | |
253 | * On success, return 0 | |
254 | */ | |
255 | static int validate_options(void) | |
256 | { | |
257 | if ((opt_session_uuid == NULL) && | |
258 | (opt_create_trace)) { | |
259 | ERR("Can't create trace without a session ID.\nPlease specify using --session UUID"); | |
260 | goto error; | |
261 | } | |
262 | ||
263 | return 0; | |
264 | ||
265 | error: | |
266 | return -1; | |
267 | } | |
268 | ||
5b8719f5 DG |
269 | /* |
270 | * spawn_sessiond | |
271 | * | |
272 | * Spawn a session daemon by forking and execv. | |
273 | */ | |
274 | static int spawn_sessiond(char *pathname) | |
275 | { | |
276 | int ret = 0; | |
277 | pid_t pid; | |
278 | ||
279 | MSG("Spawning session daemon"); | |
280 | pid = fork(); | |
281 | if (pid == 0) { | |
282 | /* Spawn session daemon and tell | |
283 | * it to signal us when ready. | |
284 | */ | |
75462a81 | 285 | ret = execlp(pathname, "ltt-sessiond", "--sig-parent", "--quiet", NULL); |
5b8719f5 DG |
286 | if (ret < 0) { |
287 | if (errno == ENOENT) { | |
288 | ERR("No session daemon found. Use --sessiond-path."); | |
289 | } else { | |
290 | perror("execlp"); | |
291 | } | |
292 | kill(getppid(), SIGTERM); | |
293 | exit(EXIT_FAILURE); | |
294 | } | |
295 | exit(EXIT_SUCCESS); | |
296 | } else if (pid > 0) { | |
297 | /* Wait for ltt-sessiond to start */ | |
298 | pause(); | |
299 | goto end; | |
300 | } else { | |
301 | perror("fork"); | |
302 | ret = -1; | |
303 | goto end; | |
304 | } | |
305 | ||
306 | end: | |
307 | return ret; | |
308 | } | |
309 | ||
fac6795d DG |
310 | /* |
311 | * check_ltt_sessiond | |
312 | * | |
313 | * Check if the session daemon is available using | |
5b8719f5 DG |
314 | * the liblttngctl API for the check. If not, try to |
315 | * spawn a daemon. | |
fac6795d DG |
316 | */ |
317 | static int check_ltt_sessiond(void) | |
318 | { | |
319 | int ret; | |
5b8719f5 | 320 | char *pathname = NULL; |
fac6795d DG |
321 | |
322 | ret = lttng_check_session_daemon(); | |
323 | if (ret < 0) { | |
5b8719f5 DG |
324 | /* Try command line option path */ |
325 | if (opt_sessiond_path != NULL) { | |
326 | ret = access(opt_sessiond_path, F_OK | X_OK); | |
327 | if (ret < 0) { | |
328 | ERR("No such file: %s", opt_sessiond_path); | |
329 | goto end; | |
330 | } | |
331 | pathname = opt_sessiond_path; | |
332 | } else { | |
333 | /* Try LTTNG_SESSIOND_PATH env variable */ | |
e8f07c63 DG |
334 | pathname = getenv(LTTNG_SESSIOND_PATH_ENV); |
335 | if (pathname != NULL) { | |
336 | /* strdup here in order to make the free() | |
337 | * not fail later on. | |
338 | */ | |
339 | pathname = strdup(pathname); | |
340 | } | |
5b8719f5 DG |
341 | } |
342 | ||
343 | /* Let's rock and roll */ | |
344 | if (pathname == NULL) { | |
345 | ret = asprintf(&pathname, "ltt-sessiond"); | |
346 | if (ret < 0) { | |
347 | goto end; | |
348 | } | |
349 | } | |
350 | ||
351 | ret = spawn_sessiond(pathname); | |
352 | free(pathname); | |
353 | if (ret < 0) { | |
354 | ERR("Problem occurs when starting %s", pathname); | |
355 | goto end; | |
356 | } | |
fac6795d DG |
357 | } |
358 | ||
5b8719f5 | 359 | end: |
fac6795d DG |
360 | return ret; |
361 | } | |
362 | ||
5b8719f5 DG |
363 | /* |
364 | * set_signal_handler | |
365 | * | |
366 | * Setup signal handler for SIGCHLD and SIGTERM. | |
367 | */ | |
368 | static int set_signal_handler(void) | |
369 | { | |
370 | int ret = 0; | |
371 | struct sigaction sa; | |
372 | sigset_t sigset; | |
373 | ||
374 | if ((ret = sigemptyset(&sigset)) < 0) { | |
375 | perror("sigemptyset"); | |
376 | goto end; | |
377 | } | |
378 | ||
379 | sa.sa_handler = sighandler; | |
380 | sa.sa_mask = sigset; | |
381 | sa.sa_flags = 0; | |
382 | if ((ret = sigaction(SIGCHLD, &sa, NULL)) < 0) { | |
383 | perror("sigaction"); | |
384 | goto end; | |
385 | } | |
fac6795d | 386 | |
5b8719f5 DG |
387 | if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) { |
388 | perror("sigaction"); | |
389 | goto end; | |
390 | } | |
391 | ||
392 | end: | |
393 | return ret; | |
394 | } | |
395 | ||
396 | /* | |
397 | * sighandler | |
398 | * | |
399 | * Signal handler for the daemon | |
400 | */ | |
401 | static void sighandler(int sig) | |
402 | { | |
403 | DBG("%d received", sig); | |
404 | switch (sig) { | |
405 | case SIGTERM: | |
406 | clean_exit(EXIT_FAILURE); | |
407 | break; | |
408 | case SIGCHLD: | |
409 | /* Notify is done */ | |
410 | break; | |
411 | default: | |
412 | break; | |
413 | } | |
414 | ||
415 | return; | |
416 | } | |
fac6795d DG |
417 | /* |
418 | * clean_exit | |
419 | */ | |
420 | void clean_exit(int code) | |
421 | { | |
422 | DBG("Clean exit"); | |
87378cf5 DG |
423 | if (lttng_disconnect_sessiond() < 0) { |
424 | ERR("Session daemon disconnect failed."); | |
425 | } | |
fac6795d DG |
426 | exit(code); |
427 | } | |
428 | ||
429 | /* | |
5b8719f5 | 430 | * main |
fac6795d DG |
431 | */ |
432 | int main(int argc, char *argv[]) | |
433 | { | |
434 | int ret; | |
435 | ||
436 | progname = argv[0] ? argv[0] : "lttng"; | |
437 | ||
438 | /* For Mathieu Desnoyers aka Dr Tracing */ | |
439 | if (strncmp(progname, "drtrace", 7) == 0) { | |
440 | MSG("%c[%d;%dmWelcome back Dr Tracing!%c[%dm\n\n", 27,1,33,27,0); | |
441 | } | |
442 | ||
443 | ret = parse_args(argc, (const char **) argv); | |
444 | if (ret < 0) { | |
87378cf5 | 445 | clean_exit(EXIT_FAILURE); |
fac6795d DG |
446 | } |
447 | ||
8548ff30 DG |
448 | ret = validate_options(); |
449 | if (ret < 0) { | |
450 | return EXIT_FAILURE; | |
451 | } | |
452 | ||
5b8719f5 DG |
453 | ret = set_signal_handler(); |
454 | if (ret < 0) { | |
87378cf5 | 455 | clean_exit(ret); |
5b8719f5 DG |
456 | } |
457 | ||
fac6795d DG |
458 | if (opt_tracing_group != NULL) { |
459 | DBG("Set tracing group to '%s'", opt_tracing_group); | |
460 | lttng_set_tracing_group(opt_tracing_group); | |
461 | } | |
462 | ||
463 | /* If ask for kernel tracing, need root perms */ | |
464 | if (opt_trace_kernel) { | |
465 | DBG("Kernel tracing activated"); | |
466 | if (getuid() != 0) { | |
467 | ERR("%s must be setuid root", progname); | |
87378cf5 | 468 | clean_exit(-EPERM); |
fac6795d DG |
469 | } |
470 | } | |
471 | ||
472 | /* Check if the lttng session daemon is running. | |
473 | * If no, a daemon will be spawned. | |
474 | */ | |
5b8719f5 | 475 | if (opt_no_sessiond == 0 && (check_ltt_sessiond() < 0)) { |
87378cf5 | 476 | clean_exit(EXIT_FAILURE); |
fac6795d DG |
477 | } |
478 | ||
479 | ret = process_client_opt(); | |
480 | if (ret < 0) { | |
87378cf5 | 481 | clean_exit(ret); |
fac6795d DG |
482 | } |
483 | ||
87378cf5 DG |
484 | clean_exit(0); |
485 | ||
fac6795d DG |
486 | return 0; |
487 | } |