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