af2278d46a2f318a91dbc2a5d28d57bed14f2f11
[lttng-tools.git] / src / bin / lttng-relayd / session.c
1 /*
2 * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com>
3 * David Goulet <dgoulet@efficios.com>
4 * 2015 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License, version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 #define _LGPL_SOURCE
21 #include <common/common.h>
22 #include <common/utils.h>
23 #include <common/compat/uuid.h>
24 #include <urcu/rculist.h>
25
26 #include <sys/stat.h>
27
28 #include "ctf-trace.h"
29 #include "lttng-relayd.h"
30 #include "session.h"
31 #include "sessiond-trace-chunks.h"
32 #include "stream.h"
33 #include <common/defaults.h>
34 #include "utils.h"
35
36 /* Global session id used in the session creation. */
37 static uint64_t last_relay_session_id;
38 static pthread_mutex_t last_relay_session_id_lock = PTHREAD_MUTEX_INITIALIZER;
39
40 static int init_session_output_path(struct relay_session *session)
41 {
42 /*
43 * session_directory:
44 *
45 * if base_path is \0'
46 * hostname/session_name
47 * else
48 * hostname/base_path
49 */
50 char *session_directory = NULL;
51 int ret = 0;
52
53 if (session->output_path[0] != '\0') {
54 goto end;
55 }
56 /*
57 * If base path is set, it overrides the session name for the
58 * session relative base path. No timestamp is appended if the
59 * base path is overridden.
60 *
61 * If the session name already contains the creation time (e.g.
62 * auto-<timestamp>, don't append yet another timestamp after
63 * the session name in the generated path.
64 *
65 * Otherwise, generate the path with session_name-<timestamp>.
66 */
67 if (session->base_path[0] != '\0') {
68 ret = asprintf(&session_directory, "%s/%s", session->hostname,
69 session->base_path);
70 } else if (session->session_name_contains_creation_time) {
71 ret = asprintf(&session_directory, "%s/%s", session->hostname,
72 session->session_name);
73 } else {
74 char session_creation_datetime[16];
75 size_t strftime_ret;
76 struct tm *timeinfo;
77 time_t creation_time;
78
79 /*
80 * The 2.11+ protocol guarantees that a creation time
81 * is provided for a session. This would indicate a
82 * protocol error or an improper use of this util.
83 */
84 if (!session->creation_time.is_set) {
85 ERR("Creation time missing for session \"%s\" (protocol error)",
86 session->session_name);
87 ret = -1;
88 goto end;
89 }
90 creation_time = LTTNG_OPTIONAL_GET(session->creation_time);
91
92 timeinfo = localtime(&creation_time);
93 if (!timeinfo) {
94 ERR("Failed to get timeinfo while initializing session output directory handle");
95 ret = -1;
96 goto end;
97 }
98 strftime_ret = strftime(session_creation_datetime,
99 sizeof(session_creation_datetime),
100 "%Y%m%d-%H%M%S", timeinfo);
101 if (strftime_ret == 0) {
102 ERR("Failed to format session creation timestamp while initializing session output directory handle");
103 ret = -1;
104 goto end;
105 }
106 ret = asprintf(&session_directory, "%s/%s-%s",
107 session->hostname, session->session_name,
108 session_creation_datetime);
109 }
110 if (ret < 0) {
111 PERROR("Failed to format session directory name");
112 goto end;
113 }
114
115 if (strlen(session_directory) >= LTTNG_PATH_MAX) {
116 ERR("Session output directory exceeds maximal length");
117 ret = -1;
118 goto end;
119 }
120 strcpy(session->output_path, session_directory);
121 ret = 0;
122
123 end:
124 free(session_directory);
125 return ret;
126 }
127
128 static int session_set_anonymous_chunk(struct relay_session *session)
129 {
130 int ret = 0;
131 struct lttng_trace_chunk *chunk = NULL;
132 enum lttng_trace_chunk_status status;
133 struct lttng_directory_handle output_directory;
134
135 ret = session_init_output_directory_handle(session, &output_directory);
136 if (ret) {
137 goto end;
138 }
139
140 chunk = lttng_trace_chunk_create_anonymous();
141 if (!chunk) {
142 goto end;
143 }
144
145 status = lttng_trace_chunk_set_credentials_current_user(chunk);
146 if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
147 ret = -1;
148 goto end;
149 }
150
151 status = lttng_trace_chunk_set_as_owner(chunk, &output_directory);
152 if (status != LTTNG_TRACE_CHUNK_STATUS_OK) {
153 ret = -1;
154 goto end;
155 }
156 session->current_trace_chunk = chunk;
157 chunk = NULL;
158 end:
159 lttng_trace_chunk_put(chunk);
160 lttng_directory_handle_fini(&output_directory);
161 return ret;
162 }
163
164 /*
165 * Create a new session by assigning a new session ID.
166 *
167 * Return allocated session or else NULL.
168 */
169 struct relay_session *session_create(const char *session_name,
170 const char *hostname, const char *base_path,
171 uint32_t live_timer,
172 bool snapshot,
173 const lttng_uuid sessiond_uuid,
174 const uint64_t *id_sessiond,
175 const uint64_t *current_chunk_id,
176 const time_t *creation_time,
177 uint32_t major,
178 uint32_t minor,
179 bool session_name_contains_creation_time)
180 {
181 int ret;
182 struct relay_session *session = NULL;
183
184 if (session_name && strstr(session_name, ".")) {
185 ERR("Illegal character in session name: \"%s\"",
186 session_name);
187 goto error;
188 }
189 if (base_path && strstr(base_path, "../")) {
190 ERR("Invalid session base path walks up the path hierarchy: \"%s\"",
191 base_path);
192 goto error;
193 }
194 if (hostname && strstr(hostname, ".")) {
195 ERR("Invalid character in hostname: \"%s\"",
196 hostname);
197 goto error;
198 }
199
200 session = zmalloc(sizeof(*session));
201 if (!session) {
202 PERROR("Failed to allocate session");
203 goto error;
204 }
205 if (lttng_strncpy(session->session_name, session_name,
206 sizeof(session->session_name))) {
207 WARN("Session name exceeds maximal allowed length");
208 goto error;
209 }
210 if (lttng_strncpy(session->hostname, hostname,
211 sizeof(session->hostname))) {
212 WARN("Hostname exceeds maximal allowed length");
213 goto error;
214 }
215 if (lttng_strncpy(session->base_path, base_path,
216 sizeof(session->base_path))) {
217 WARN("Base path exceeds maximal allowed length");
218 goto error;
219 }
220 if (creation_time) {
221 LTTNG_OPTIONAL_SET(&session->creation_time, *creation_time);
222 }
223 session->session_name_contains_creation_time =
224 session_name_contains_creation_time;
225
226 session->ctf_traces_ht = lttng_ht_new(0, LTTNG_HT_TYPE_STRING);
227 if (!session->ctf_traces_ht) {
228 goto error;
229 }
230
231 pthread_mutex_lock(&last_relay_session_id_lock);
232 session->id = ++last_relay_session_id;
233 pthread_mutex_unlock(&last_relay_session_id_lock);
234
235 session->major = major;
236 session->minor = minor;
237 lttng_ht_node_init_u64(&session->session_n, session->id);
238 urcu_ref_init(&session->ref);
239 CDS_INIT_LIST_HEAD(&session->recv_list);
240 pthread_mutex_init(&session->lock, NULL);
241 pthread_mutex_init(&session->recv_list_lock, NULL);
242
243 session->live_timer = live_timer;
244 session->snapshot = snapshot;
245 lttng_uuid_copy(session->sessiond_uuid, sessiond_uuid);
246
247 if (id_sessiond) {
248 LTTNG_OPTIONAL_SET(&session->id_sessiond, *id_sessiond);
249 }
250
251 if (major == 2 && minor >= 11) {
252 /* Only applies for 2.11+ peers using trace chunks. */
253 ret = init_session_output_path(session);
254 if (ret) {
255 goto error;
256 }
257 }
258
259 ret = sessiond_trace_chunk_registry_session_created(
260 sessiond_trace_chunk_registry, sessiond_uuid);
261 if (ret) {
262 goto error;
263 }
264
265 if (id_sessiond && current_chunk_id) {
266 session->current_trace_chunk =
267 sessiond_trace_chunk_registry_get_chunk(
268 sessiond_trace_chunk_registry,
269 session->sessiond_uuid,
270 session->id_sessiond.value,
271 *current_chunk_id);
272 if (!session->current_trace_chunk) {
273 char uuid_str[UUID_STR_LEN];
274
275 lttng_uuid_to_str(sessiond_uuid, uuid_str);
276 ERR("Could not find trace chunk: sessiond = {%s}, sessiond session id = %" PRIu64 ", trace chunk id = %" PRIu64,
277 uuid_str, *id_sessiond,
278 *current_chunk_id);
279 }
280 } else if (!id_sessiond) {
281 /*
282 * Pre-2.11 peers will not announce trace chunks. An
283 * anonymous trace chunk which will remain set for the
284 * duration of the session is created.
285 */
286 ret = session_set_anonymous_chunk(session);
287 if (ret) {
288 goto error;
289 }
290 }
291
292 lttng_ht_add_unique_u64(sessions_ht, &session->session_n);
293 return session;
294
295 error:
296 session_put(session);
297 return NULL;
298 }
299
300 /* Should be called with RCU read-side lock held. */
301 bool session_get(struct relay_session *session)
302 {
303 return urcu_ref_get_unless_zero(&session->ref);
304 }
305
306 /*
307 * Lookup a session within the session hash table using the session id
308 * as key. A session reference is taken when a session is returned.
309 * session_put() must be called on that session.
310 *
311 * Return session or NULL if not found.
312 */
313 struct relay_session *session_get_by_id(uint64_t id)
314 {
315 struct relay_session *session = NULL;
316 struct lttng_ht_node_u64 *node;
317 struct lttng_ht_iter iter;
318
319 rcu_read_lock();
320 lttng_ht_lookup(sessions_ht, &id, &iter);
321 node = lttng_ht_iter_get_node_u64(&iter);
322 if (!node) {
323 DBG("Session find by ID %" PRIu64 " id NOT found", id);
324 goto end;
325 }
326 session = caa_container_of(node, struct relay_session, session_n);
327 DBG("Session find by ID %" PRIu64 " id found", id);
328 if (!session_get(session)) {
329 session = NULL;
330 }
331 end:
332 rcu_read_unlock();
333 return session;
334 }
335
336 static void rcu_destroy_session(struct rcu_head *rcu_head)
337 {
338 struct relay_session *session =
339 caa_container_of(rcu_head, struct relay_session,
340 rcu_node);
341 /*
342 * Since each trace has a reference on the session, it means
343 * that if we are at the point where we teardown the session, no
344 * trace belonging to that session exist at this point.
345 * Calling lttng_ht_destroy in call_rcu worker thread so we
346 * don't hold the RCU read-side lock while calling it.
347 */
348 lttng_ht_destroy(session->ctf_traces_ht);
349 free(session);
350 }
351
352 /*
353 * Delete session from the given hash table.
354 *
355 * Return lttng ht del error code being 0 on success and 1 on failure.
356 */
357 static int session_delete(struct relay_session *session)
358 {
359 struct lttng_ht_iter iter;
360
361 iter.iter.node = &session->session_n.node;
362 return lttng_ht_del(sessions_ht, &iter);
363 }
364
365
366 static void destroy_session(struct relay_session *session)
367 {
368 int ret;
369
370 ret = session_delete(session);
371 assert(!ret);
372 lttng_trace_chunk_put(session->current_trace_chunk);
373 session->current_trace_chunk = NULL;
374 lttng_trace_chunk_put(session->pending_closure_trace_chunk);
375 session->pending_closure_trace_chunk = NULL;
376 ret = sessiond_trace_chunk_registry_session_destroyed(
377 sessiond_trace_chunk_registry, session->sessiond_uuid);
378 assert(!ret);
379 call_rcu(&session->rcu_node, rcu_destroy_session);
380 }
381
382 void session_release(struct urcu_ref *ref)
383 {
384 struct relay_session *session =
385 caa_container_of(ref, struct relay_session, ref);
386
387 destroy_session(session);
388 }
389
390 void session_put(struct relay_session *session)
391 {
392 rcu_read_lock();
393 urcu_ref_put(&session->ref, session_release);
394 rcu_read_unlock();
395 }
396
397 int session_close(struct relay_session *session)
398 {
399 int ret = 0;
400 struct ctf_trace *trace;
401 struct lttng_ht_iter iter;
402 struct relay_stream *stream;
403
404 pthread_mutex_lock(&session->lock);
405 DBG("closing session %" PRIu64 ": is conn already closed %d",
406 session->id, session->connection_closed);
407 session->connection_closed = true;
408 pthread_mutex_unlock(&session->lock);
409
410 rcu_read_lock();
411 cds_lfht_for_each_entry(session->ctf_traces_ht->ht,
412 &iter.iter, trace, node.node) {
413 ret = ctf_trace_close(trace);
414 if (ret) {
415 goto rcu_unlock;
416 }
417 }
418 cds_list_for_each_entry_rcu(stream, &session->recv_list,
419 recv_node) {
420 /* Close streams which have not been published yet. */
421 try_stream_close(stream);
422 }
423 rcu_unlock:
424 rcu_read_unlock();
425 if (ret) {
426 return ret;
427 }
428 /* Put self-reference from create. */
429 session_put(session);
430 return ret;
431 }
432
433 int session_abort(struct relay_session *session)
434 {
435 int ret = 0;
436
437 if (!session) {
438 return 0;
439 }
440
441 pthread_mutex_lock(&session->lock);
442 DBG("aborting session %" PRIu64, session->id);
443 session->aborted = true;
444 pthread_mutex_unlock(&session->lock);
445 return ret;
446 }
447
448 void print_sessions(void)
449 {
450 struct lttng_ht_iter iter;
451 struct relay_session *session;
452
453 if (!sessions_ht) {
454 return;
455 }
456
457 rcu_read_lock();
458 cds_lfht_for_each_entry(sessions_ht->ht, &iter.iter, session,
459 session_n.node) {
460 if (!session_get(session)) {
461 continue;
462 }
463 DBG("session %p refcount %ld session %" PRIu64,
464 session,
465 session->ref.refcount,
466 session->id);
467 session_put(session);
468 }
469 rcu_read_unlock();
470 }
471
472 int session_init_output_directory_handle(struct relay_session *session,
473 struct lttng_directory_handle *handle)
474 {
475 int ret;
476 /*
477 * relayd_output_path/session_directory
478 * e.g. /home/user/lttng-traces/hostname/session_name
479 */
480 char *full_session_path = NULL;
481
482 pthread_mutex_lock(&session->lock);
483 full_session_path = create_output_path(session->output_path);
484 if (!full_session_path) {
485 ret = -1;
486 goto end;
487 }
488
489 ret = utils_mkdir_recursive(
490 full_session_path, S_IRWXU | S_IRWXG, -1, -1);
491 if (ret) {
492 ERR("Failed to create session output path \"%s\"",
493 full_session_path);
494 goto end;
495 }
496
497 ret = lttng_directory_handle_init(handle, full_session_path);
498 if (ret) {
499 goto end;
500 }
501 end:
502 pthread_mutex_unlock(&session->lock);
503 free(full_session_path);
504 return ret;
505 }
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