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