3ba5766ea00c0e45dd332126956434d579bdf7d9
[lttng-tools.git] / src / bin / lttng / commands / view.c
1 /*
2 * Copyright (C) 2011 David Goulet <dgoulet@efficios.com>
3 *
4 * SPDX-License-Identifier: GPL-2.0-only
5 *
6 */
7
8 #define _LGPL_SOURCE
9 #include <popt.h>
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <string.h>
13 #include <sys/stat.h>
14 #include <sys/types.h>
15 #include <unistd.h>
16
17 #include "../command.h"
18
19 static char *opt_session_name;
20 static char *opt_viewer;
21 static char *opt_trace_path;
22 static const char *babeltrace_bin = CONFIG_BABELTRACE_BIN;
23 static const char *babeltrace2_bin = CONFIG_BABELTRACE2_BIN;
24
25 #ifdef LTTNG_EMBED_HELP
26 static const char help_msg[] =
27 #include <lttng-view.1.h>
28 ;
29 #endif
30
31 enum {
32 OPT_HELP = 1,
33 OPT_LIST_OPTIONS,
34 };
35
36 static struct poptOption long_options[] = {
37 /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
38 {"help", 'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
39 {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
40 {"viewer", 'e', POPT_ARG_STRING, &opt_viewer, 0, 0, 0},
41 {"trace-path", 't', POPT_ARG_STRING, &opt_trace_path, 0, 0, 0},
42 {0, 0, 0, 0, 0, 0, 0}
43 };
44
45 /*
46 * This is needed for each viewer since we are using execvp().
47 */
48 static const char *babeltrace_opts[] = { "babeltrace" };
49 static const char *babeltrace2_opts[] = { "babeltrace2" };
50
51 /*
52 * Type is also use as the index in the viewers array. So please, make sure
53 * your enum value is in the right order in the array below.
54 */
55 enum viewer_type {
56 VIEWER_BABELTRACE = 0,
57 VIEWER_BABELTRACE2 = 1,
58 VIEWER_USER_DEFINED = 2,
59 };
60
61 static const struct viewer {
62 const char *exec_name;
63 enum viewer_type type;
64 } viewers[] = {
65 { "babeltrace", VIEWER_BABELTRACE },
66 { "babeltrace2", VIEWER_BABELTRACE2 },
67 { NULL, VIEWER_USER_DEFINED },
68 };
69
70 /* Is the session we are trying to view is in live mode. */
71 static int session_live_mode;
72
73 static const struct viewer *parse_viewer_option(void)
74 {
75 if (opt_viewer == NULL) {
76 /* Default is babeltrace2 */
77 return &(viewers[VIEWER_BABELTRACE2]);
78 }
79
80 return &(viewers[VIEWER_USER_DEFINED]);
81 }
82
83 /*
84 * Alloc an array of string pointer from a simple string having all options
85 * seperated by spaces. Also adds the trace path to the arguments.
86 *
87 * The returning pointer is ready to be passed to execvp().
88 */
89 static char **alloc_argv_from_user_opts(char *opts, const char *trace_path)
90 {
91 int i = 0, ignore_space = 0;
92 unsigned int num_opts = 1;
93 char **argv, *token = opts;
94
95 /* Count number of arguments. */
96 do {
97 if (*token == ' ') {
98 /* Use to ignore consecutive spaces */
99 if (!ignore_space) {
100 num_opts++;
101 }
102 ignore_space = 1;
103 } else {
104 ignore_space = 0;
105 }
106 token++;
107 } while (*token != '\0');
108
109 /* Add two here for the NULL terminating element and trace path */
110 argv = zmalloc(sizeof(char *) * (num_opts + 2));
111 if (argv == NULL) {
112 goto error;
113 }
114
115 token = strtok(opts, " ");
116 while (token != NULL) {
117 argv[i] = strdup(token);
118 if (argv[i] == NULL) {
119 goto error;
120 }
121 token = strtok(NULL, " ");
122 i++;
123 }
124
125 argv[num_opts] = (char *) trace_path;
126 argv[num_opts + 1] = NULL;
127
128 return argv;
129
130 error:
131 if (argv) {
132 for (i = 0; i < num_opts + 2; i++) {
133 free(argv[i]);
134 }
135 free(argv);
136 }
137
138 return NULL;
139 }
140
141 /*
142 * Alloc an array of string pointer from an array of strings. It also adds
143 * the trace path to the argv.
144 *
145 * The returning pointer is ready to be passed to execvp().
146 */
147 static char **alloc_argv_from_local_opts(const char **opts, size_t opts_len,
148 const char *trace_path)
149 {
150 char **argv;
151 size_t size, mem_len;
152
153 /* Add one for the NULL terminating element. */
154 mem_len = opts_len + 1;
155 if (session_live_mode) {
156 /* Add 3 option for the live mode being "-i lttng-live URL". */
157 mem_len += 3;
158 } else {
159 /* Add option for the trace path. */
160 mem_len += 1;
161 }
162
163 size = sizeof(char *) * mem_len;
164
165 /* Add two here for the trace_path and the NULL terminating element. */
166 argv = zmalloc(size);
167 if (argv == NULL) {
168 goto error;
169 }
170
171 memcpy(argv, opts, sizeof(char *) * opts_len);
172
173 if (session_live_mode) {
174 argv[opts_len] = (char *) "-i";
175 argv[opts_len + 1] = (char *) "lttng-live";
176 argv[opts_len + 2] = (char *) trace_path;
177 argv[opts_len + 3] = NULL;
178 } else {
179 argv[opts_len] = (char *) trace_path;
180 argv[opts_len + 1] = NULL;
181 }
182
183 error:
184 return argv;
185 }
186
187 /*
188 * Spawn viewer with the trace directory path.
189 */
190 static int spawn_viewer(const char *trace_path)
191 {
192 int ret = 0;
193 struct stat status;
194 const char *viewer_bin = NULL;
195 const struct viewer *viewer;
196 char **argv = NULL;
197
198 /* Check for --viewer option. */
199 viewer = parse_viewer_option();
200 if (viewer == NULL) {
201 ret = CMD_ERROR;
202 goto error;
203 }
204
205 retry_viewer:
206 switch (viewer->type) {
207 case VIEWER_BABELTRACE2:
208 if (stat(babeltrace2_bin, &status) == 0) {
209 viewer_bin = babeltrace2_bin;
210 } else {
211 viewer_bin = viewer->exec_name;
212 }
213 argv = alloc_argv_from_local_opts(babeltrace2_opts,
214 ARRAY_SIZE(babeltrace2_opts), trace_path);
215 break;
216 case VIEWER_BABELTRACE:
217 if (stat(babeltrace_bin, &status) == 0) {
218 viewer_bin = babeltrace_bin;
219 } else {
220 viewer_bin = viewer->exec_name;
221 }
222 argv = alloc_argv_from_local_opts(babeltrace_opts,
223 ARRAY_SIZE(babeltrace_opts), trace_path);
224 break;
225 case VIEWER_USER_DEFINED:
226 argv = alloc_argv_from_user_opts(opt_viewer, trace_path);
227 if (argv) {
228 viewer_bin = argv[0];
229 }
230 break;
231 default:
232 viewer_bin = viewers[VIEWER_BABELTRACE].exec_name;
233 argv = alloc_argv_from_local_opts(babeltrace_opts,
234 ARRAY_SIZE(babeltrace_opts), trace_path);
235 break;
236 }
237
238 if (argv == NULL || !viewer_bin) {
239 ret = CMD_FATAL;
240 goto error;
241 }
242
243 DBG("Using %s viewer", viewer_bin);
244
245 ret = execvp(viewer_bin, argv);
246 if (ret) {
247 if (errno == ENOENT && viewer->exec_name) {
248 if (viewer->type == VIEWER_BABELTRACE2) {
249 /* Fallback to legacy babeltrace. */
250 DBG("babeltrace2 not installed on the system, falling back to babeltrace 1.x");
251 viewer = &viewers[VIEWER_BABELTRACE];
252 free(argv);
253 argv = NULL;
254 goto retry_viewer;
255 } else {
256 ERR("Viewer \"%s\" not found on the system",
257 viewer_bin);
258 }
259 } else {
260 PERROR("Failed to launch \"%s\" viewer", viewer_bin);
261 }
262 ret = CMD_FATAL;
263 goto error;
264 }
265
266 error:
267 free(argv);
268 return ret;
269 }
270
271 /*
272 * Build the live path we need for the lttng live view.
273 */
274 static char *build_live_path(char *session_name)
275 {
276 int ret;
277 char *path = NULL;
278 char hostname[HOST_NAME_MAX];
279
280 ret = gethostname(hostname, sizeof(hostname));
281 if (ret < 0) {
282 PERROR("gethostname");
283 goto error;
284 }
285
286 ret = asprintf(&path, "net://localhost/host/%s/%s", hostname,
287 session_name);
288 if (ret < 0) {
289 PERROR("asprintf live path");
290 goto error;
291 }
292
293 error:
294 return path;
295 }
296
297 /*
298 * Exec viewer if found and use session name path.
299 */
300 static int view_trace(void)
301 {
302 int ret;
303 char *session_name, *trace_path = NULL;
304 struct lttng_session *sessions = NULL;
305 bool free_trace_path = false;
306
307 /*
308 * Safety net. If lttng is suid at some point for *any* useless reasons,
309 * this prevent any bad execution of binaries.
310 */
311 if (getuid() != 0) {
312 if (getuid() != geteuid()) {
313 ERR("UID does not match effective UID.");
314 ret = CMD_ERROR;
315 goto error;
316 } else if (getgid() != getegid()) {
317 ERR("GID does not match effective GID.");
318 ret = CMD_ERROR;
319 goto error;
320 }
321 }
322
323 /* User define trace path override the session name */
324 if (opt_trace_path) {
325 session_name = NULL;
326 } else if(opt_session_name == NULL) {
327 session_name = get_session_name();
328 if (session_name == NULL) {
329 ret = CMD_ERROR;
330 goto error;
331 }
332 } else {
333 session_name = opt_session_name;
334 }
335
336 DBG("Viewing trace for session %s", session_name);
337
338 if (session_name) {
339 int i, count, found = 0;
340
341 /* Getting all sessions */
342 count = lttng_list_sessions(&sessions);
343 if (count < 0) {
344 ERR("Unable to list sessions. Session name %s not found.",
345 session_name);
346 MSG("Is there a session daemon running?");
347 ret = CMD_ERROR;
348 goto free_error;
349 }
350
351 /* Find our session listed by the session daemon */
352 for (i = 0; i < count; i++) {
353 if (strncmp(sessions[i].name, session_name, NAME_MAX) == 0) {
354 found = 1;
355 break;
356 }
357 }
358
359 if (!found) {
360 MSG("Session name %s not found", session_name);
361 ret = CMD_ERROR;
362 goto free_sessions;
363 }
364
365 session_live_mode = sessions[i].live_timer_interval;
366
367 DBG("Session live mode set to %d", session_live_mode);
368
369 if (sessions[i].enabled && !session_live_mode) {
370 WARN("Session %s is running. Please stop it before reading it.",
371 session_name);
372 ret = CMD_ERROR;
373 goto free_sessions;
374 }
375
376 /* If the timer interval is set we are in live mode. */
377 if (session_live_mode) {
378 trace_path = build_live_path(session_name);
379 if (!trace_path) {
380 ret = CMD_ERROR;
381 goto free_sessions;
382 }
383 free_trace_path = true;
384 } else {
385 /* Get file system session path. */
386 trace_path = sessions[i].path;
387 }
388 } else {
389 trace_path = opt_trace_path;
390 }
391
392 MSG("Trace directory: %s\n", trace_path);
393
394 ret = spawn_viewer(trace_path);
395 if (ret < 0) {
396 /* Don't set ret so lttng can interpret the sessiond error. */
397 goto free_sessions;
398 }
399
400 free_sessions:
401 if (session_live_mode && free_trace_path) {
402 free(trace_path);
403 }
404 free(sessions);
405 free_error:
406 if (opt_session_name == NULL) {
407 free(session_name);
408 }
409 error:
410 return ret;
411 }
412
413 /*
414 * The 'view <options>' first level command
415 */
416 int cmd_view(int argc, const char **argv)
417 {
418 int opt, ret = CMD_SUCCESS;
419 static poptContext pc;
420 const char *leftover = NULL;
421
422 pc = poptGetContext(NULL, argc, argv, long_options, 0);
423 poptReadDefaultConfig(pc, 0);
424
425 if (lttng_opt_mi) {
426 WARN("mi does not apply to view command");
427 }
428
429 while ((opt = poptGetNextOpt(pc)) != -1) {
430 switch (opt) {
431 case OPT_HELP:
432 SHOW_HELP();
433 goto end;
434 case OPT_LIST_OPTIONS:
435 list_cmd_options(stdout, long_options);
436 goto end;
437 default:
438 ret = CMD_UNDEFINED;
439 goto end;
440 }
441 }
442
443 opt_session_name = (char*) poptGetArg(pc);
444
445 leftover = poptGetArg(pc);
446 if (leftover) {
447 ERR("Unknown argument: %s", leftover);
448 ret = CMD_ERROR;
449 goto end;
450 }
451
452 ret = view_trace();
453
454 end:
455 poptFreeContext(pc);
456 return ret;
457 }
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