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