2 * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
3 * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
4 * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 * SPDX-License-Identifier: GPL-2.0-only
12 #include "connection.hpp"
13 #include "ctf-trace.hpp"
14 #include "health-relayd.hpp"
16 #include "lttng-relayd.hpp"
17 #include "session.hpp"
19 #include "testpoint.hpp"
21 #include "viewer-session.hpp"
22 #include "viewer-stream.hpp"
24 #include <common/common.hpp>
25 #include <common/compat/endian.hpp>
26 #include <common/compat/poll.hpp>
27 #include <common/compat/socket.hpp>
28 #include <common/defaults.hpp>
29 #include <common/fd-tracker/utils.hpp>
30 #include <common/fs-handle.hpp>
31 #include <common/futex.hpp>
32 #include <common/index/index.hpp>
33 #include <common/make-unique-wrapper.hpp>
34 #include <common/pthread-lock.hpp>
35 #include <common/sessiond-comm/inet.hpp>
36 #include <common/sessiond-comm/relayd.hpp>
37 #include <common/sessiond-comm/sessiond-comm.hpp>
38 #include <common/urcu.hpp>
39 #include <common/uri.hpp>
40 #include <common/utils.hpp>
42 #include <lttng/lttng.h>
56 #include <sys/mount.h>
57 #include <sys/resource.h>
58 #include <sys/socket.h>
60 #include <sys/types.h>
63 #include <urcu/futex.h>
64 #include <urcu/rculist.h>
65 #include <urcu/uatomic.h>
67 #define SESSION_BUF_DEFAULT_COUNT 16
69 static struct lttng_uri
*live_uri
;
72 * This pipe is used to inform the worker thread that a command is queued and
73 * ready to be processed.
75 static int live_conn_pipe
[2] = { -1, -1 };
77 /* Shared between threads */
78 static int live_dispatch_thread_exit
;
80 static pthread_t live_listener_thread
;
81 static pthread_t live_dispatcher_thread
;
82 static pthread_t live_worker_thread
;
85 * Relay command queue.
87 * The live_thread_listener and live_thread_dispatcher communicate with this
90 static struct relay_conn_queue viewer_conn_queue
;
92 static uint64_t last_relay_viewer_session_id
;
93 static pthread_mutex_t last_relay_viewer_session_id_lock
= PTHREAD_MUTEX_INITIALIZER
;
95 static const char *lttng_viewer_command_str(lttng_viewer_command cmd
)
98 case LTTNG_VIEWER_CONNECT
:
100 case LTTNG_VIEWER_LIST_SESSIONS
:
101 return "LIST_SESSIONS";
102 case LTTNG_VIEWER_ATTACH_SESSION
:
103 return "ATTACH_SESSION";
104 case LTTNG_VIEWER_GET_NEXT_INDEX
:
105 return "GET_NEXT_INDEX";
106 case LTTNG_VIEWER_GET_PACKET
:
108 case LTTNG_VIEWER_GET_METADATA
:
109 return "GET_METADATA";
110 case LTTNG_VIEWER_GET_NEW_STREAMS
:
111 return "GET_NEW_STREAMS";
112 case LTTNG_VIEWER_CREATE_SESSION
:
113 return "CREATE_SESSION";
114 case LTTNG_VIEWER_DETACH_SESSION
:
115 return "DETACH_SESSION";
122 lttng_viewer_next_index_return_code_str(enum lttng_viewer_next_index_return_code code
)
125 case LTTNG_VIEWER_INDEX_OK
:
127 case LTTNG_VIEWER_INDEX_RETRY
:
128 return "INDEX_RETRY";
129 case LTTNG_VIEWER_INDEX_HUP
:
131 case LTTNG_VIEWER_INDEX_ERR
:
133 case LTTNG_VIEWER_INDEX_INACTIVE
:
134 return "INDEX_INACTIVE";
135 case LTTNG_VIEWER_INDEX_EOF
:
142 static const char *lttng_viewer_attach_return_code_str(enum lttng_viewer_attach_return_code code
)
145 case LTTNG_VIEWER_ATTACH_OK
:
147 case LTTNG_VIEWER_ATTACH_ALREADY
:
148 return "ATTACH_ALREADY";
149 case LTTNG_VIEWER_ATTACH_UNK
:
151 case LTTNG_VIEWER_ATTACH_NOT_LIVE
:
152 return "ATTACH_NOT_LIVE";
153 case LTTNG_VIEWER_ATTACH_SEEK_ERR
:
154 return "ATTACH_SEEK_ERR";
155 case LTTNG_VIEWER_ATTACH_NO_SESSION
:
156 return "ATTACH_NO_SESSION";
163 lttng_viewer_get_packet_return_code_str(enum lttng_viewer_get_packet_return_code code
)
166 case LTTNG_VIEWER_GET_PACKET_OK
:
167 return "GET_PACKET_OK";
168 case LTTNG_VIEWER_GET_PACKET_RETRY
:
169 return "GET_PACKET_RETRY";
170 case LTTNG_VIEWER_GET_PACKET_ERR
:
171 return "GET_PACKET_ERR";
172 case LTTNG_VIEWER_GET_PACKET_EOF
:
173 return "GET_PACKET_EOF";
182 static void cleanup_relayd_live()
190 * Receive a request buffer using a given socket, destination allocated buffer
193 * Return the size of the received message or else a negative value on error
194 * with errno being set by recvmsg() syscall.
196 static ssize_t
recv_request(struct lttcomm_sock
*sock
, void *buf
, size_t size
)
200 ret
= sock
->ops
->recvmsg(sock
, buf
, size
, 0);
201 if (ret
< 0 || ret
!= size
) {
203 /* Orderly shutdown. Not necessary to print an error. */
204 DBG("Socket %d did an orderly shutdown", sock
->fd
);
206 ERR("Relay failed to receive request.");
215 * Send a response buffer using a given socket, source allocated buffer of
218 * Return the size of the sent message or else a negative value on error with
219 * errno being set by sendmsg() syscall.
221 static ssize_t
send_response(struct lttcomm_sock
*sock
, void *buf
, size_t size
)
225 ret
= sock
->ops
->sendmsg(sock
, buf
, size
, 0);
227 ERR("Relayd failed to send response.");
234 * Atomically check if new streams got added in one of the sessions attached
235 * and reset the flag to 0.
237 * Returns 1 if new streams got added, 0 if nothing changed, a negative value
240 static int check_new_streams(struct relay_connection
*conn
)
244 if (!conn
->viewer_session
) {
249 lttng::urcu::rcu_list_iteration_adapter
<relay_session
,
250 &relay_session::viewer_session_node
>(
251 conn
->viewer_session
->session_list
)) {
252 if (!session_get(session
)) {
256 ret
= uatomic_read(&session
->new_streams
);
257 session_put(session
);
264 DBG("Viewer connection has%s new streams: socket_fd = %d",
265 ret
== 0 ? " no" : "",
271 * Sends one viewer stream to the given socket.
273 * This function needs to be called with the stream locked.
275 * Return 0 on success, or else a negative value.
277 static ssize_t
send_one_viewer_stream(struct lttcomm_sock
*sock
,
278 struct relay_viewer_stream
*vstream
)
280 struct ctf_trace
*ctf_trace
;
281 struct lttng_viewer_stream send_stream
= {};
284 ASSERT_LOCKED(vstream
->stream
->lock
);
286 ctf_trace
= vstream
->stream
->trace
;
287 send_stream
.id
= htobe64(vstream
->stream
->stream_handle
);
288 send_stream
.ctf_trace_id
= htobe64(ctf_trace
->id
);
289 send_stream
.metadata_flag
= htobe32(vstream
->stream
->is_metadata
);
291 send_stream
.path_name
, vstream
->path_name
, sizeof(send_stream
.path_name
))) {
292 ret
= -1; /* Error. */
295 if (lttng_strncpy(send_stream
.channel_name
,
296 vstream
->channel_name
,
297 sizeof(send_stream
.channel_name
))) {
298 ret
= -1; /* Error. */
302 DBG("Sending stream %" PRIu64
" to viewer", vstream
->stream
->stream_handle
);
303 vstream
->sent_flag
= true;
305 ret
= send_response(sock
, &send_stream
, sizeof(send_stream
));
317 * Send viewer streams to the given socket. The ignore_sent_flag indicates if
318 * this function should ignore the sent flag or not.
320 * Return 0 on success or else a negative value.
322 static ssize_t
send_viewer_streams(struct lttcomm_sock
*sock
,
324 unsigned int ignore_sent_flag
,
325 struct relay_viewer_session
*viewer_session
)
330 lttng::urcu::lfht_iteration_adapter
<relay_viewer_stream
,
331 decltype(relay_viewer_stream::stream_n
),
332 &relay_viewer_stream::stream_n
>(
333 *viewer_streams_ht
->ht
)) {
334 health_code_update();
336 if (!viewer_stream_get(vstream
)) {
340 pthread_mutex_lock(&vstream
->stream
->lock
);
341 /* Ignore if not the same session. */
342 if (vstream
->stream
->trace
->session
->id
!= session_id
||
343 (!ignore_sent_flag
&& vstream
->sent_flag
)) {
344 pthread_mutex_unlock(&vstream
->stream
->lock
);
345 viewer_stream_put(vstream
);
349 ret
= send_one_viewer_stream(sock
, vstream
);
350 pthread_mutex_unlock(&vstream
->stream
->lock
);
352 viewer_stream_put(vstream
);
356 pthread_mutex_lock(&viewer_session
->unannounced_stream_list_lock
);
357 cds_list_del_rcu(&vstream
->viewer_stream_node
);
358 pthread_mutex_unlock(&viewer_session
->unannounced_stream_list_lock
);
359 viewer_stream_put(vstream
);
363 * Any remaining streams that have been seen, but are perhaps unpublished
364 * due to a session being destroyed in between attach and get_new_streams.
367 lttng::urcu::rcu_list_iteration_adapter
<relay_viewer_stream
,
368 &relay_viewer_stream::viewer_stream_node
>(
369 viewer_session
->unannounced_stream_list
)) {
370 health_code_update();
371 if (!viewer_stream_get(vstream
)) {
375 pthread_mutex_lock(&vstream
->stream
->lock
);
376 if (vstream
->stream
->trace
->session
->id
!= session_id
) {
377 pthread_mutex_unlock(&vstream
->stream
->lock
);
378 viewer_stream_put(vstream
);
382 ret
= send_one_viewer_stream(sock
, vstream
);
383 pthread_mutex_unlock(&vstream
->stream
->lock
);
385 viewer_stream_put(vstream
);
389 pthread_mutex_lock(&viewer_session
->unannounced_stream_list_lock
);
390 cds_list_del_rcu(&vstream
->viewer_stream_node
);
391 viewer_stream_put(vstream
);
392 pthread_mutex_unlock(&viewer_session
->unannounced_stream_list_lock
);
393 viewer_stream_put(vstream
);
403 * Create every viewer stream possible for the given session with the seek
404 * type. Three counters *can* be return which are in order the total amount of
405 * viewer stream of the session, the number of unsent stream and the number of
406 * stream created. Those counters can be NULL and thus will be ignored.
408 * session must be locked to ensure that we see either none or all initial
409 * streams for a session, but no intermediate state..
411 * Return 0 on success or else a negative value.
413 int make_viewer_streams(struct relay_session
*relay_session
,
414 struct relay_viewer_session
*viewer_session
,
415 enum lttng_viewer_seek seek_t
,
416 unsigned int *nb_total
,
417 unsigned int *nb_unsent
,
418 unsigned int *nb_created
,
423 LTTNG_ASSERT(relay_session
);
424 ASSERT_LOCKED(relay_session
->lock
);
426 if (relay_session
->connection_closed
) {
431 * Check unannounced viewer streams for any that have been seen but are no longer published.
433 for (auto *viewer_stream
:
434 lttng::urcu::rcu_list_iteration_adapter
<relay_viewer_stream
,
435 &relay_viewer_stream::viewer_stream_node
>(
436 viewer_session
->unannounced_stream_list
)) {
437 if (!viewer_stream_get(viewer_stream
)) {
438 DBG("Couldn't get reference for viewer_stream");
442 if (viewer_stream
->sent_flag
) {
443 ERR("logic error -> viewer stream %ld is in unannounced_stream_list is marked as sent",
444 viewer_stream
->stream
->stream_handle
);
448 if (viewer_stream
->stream
->published
) {
450 * This stream should be handled later when iterating via the
453 viewer_stream_put(viewer_stream
);
457 if (viewer_stream
->stream
->trace
->session
->id
!= relay_session
->id
) {
458 viewer_stream_put(viewer_stream
);
470 viewer_stream_put(viewer_stream
);
474 * Create viewer streams for relay streams that are ready to be
475 * used for a the given session id only.
477 for (auto *raw_ctf_trace
: lttng::urcu::
478 lfht_iteration_adapter
<ctf_trace
, decltype(ctf_trace::node
), &ctf_trace::node
>(
479 *relay_session
->ctf_traces_ht
->ht
)) {
480 bool trace_has_metadata_stream
= false;
482 health_code_update();
484 if (!ctf_trace_get(raw_ctf_trace
)) {
489 lttng::make_unique_wrapper
<struct ctf_trace
, ctf_trace_put
>(raw_ctf_trace
);
491 * The trace metadata state may be updated while iterating over all the
492 * relay streams associated with the trace, so the lock is required.
494 const lttng::pthread::lock_guard
ctf_trace_lock(ctf_trace
->lock
);
497 * Iterate over all the streams of the trace to see if we have a
501 lttng::urcu::rcu_list_iteration_adapter
<relay_stream
,
502 &relay_stream::stream_node
>(
503 ctf_trace
->stream_list
)) {
504 bool is_metadata_stream
;
506 pthread_mutex_lock(&stream
->lock
);
507 is_metadata_stream
= stream
->is_metadata
;
508 pthread_mutex_unlock(&stream
->lock
);
510 if (is_metadata_stream
) {
511 trace_has_metadata_stream
= true;
517 * If there is no metadata stream in this trace at the moment
518 * and we never sent one to the viewer, skip the trace. We
519 * accept that the viewer will not see this trace at all.
521 if (!trace_has_metadata_stream
&& !ctf_trace
->metadata_stream_sent_to_viewer
) {
525 for (auto *raw_stream
:
526 lttng::urcu::rcu_list_iteration_adapter
<relay_stream
,
527 &relay_stream::stream_node
>(
528 ctf_trace
->stream_list
)) {
529 struct relay_viewer_stream
*viewer_stream
;
531 if (!stream_get(raw_stream
)) {
536 lttng::make_unique_wrapper
<relay_stream
, stream_put
>(raw_stream
);
537 raw_stream
= nullptr;
539 const lttng::pthread::lock_guard
stream_lock(stream
->lock
);
541 * stream published is protected by the session lock.
543 if (!stream
->published
) {
546 viewer_stream
= viewer_stream_get_by_id(stream
->stream_handle
);
547 if (!viewer_stream
) {
548 struct lttng_trace_chunk
*viewer_stream_trace_chunk
= nullptr;
551 * Save that we sent the metadata stream to the
552 * viewer. So that we know what trace the viewer
555 if (stream
->is_metadata
) {
556 ctf_trace
->metadata_stream_sent_to_viewer
= true;
560 * If a rotation is ongoing, use a copy of the
561 * relay stream's chunk to ensure the stream
564 * Otherwise, the viewer session's current trace
565 * chunk can be used safely.
567 if ((stream
->ongoing_rotation
.is_set
||
568 session_has_ongoing_rotation(relay_session
)) &&
569 stream
->trace_chunk
) {
570 viewer_stream_trace_chunk
=
571 lttng_trace_chunk_copy(stream
->trace_chunk
);
572 if (!viewer_stream_trace_chunk
) {
578 * Transition the viewer session into the newest
579 * trace chunk available.
581 if (!lttng_trace_chunk_ids_equal(
582 viewer_session
->current_trace_chunk
,
583 stream
->trace_chunk
)) {
584 ret
= viewer_session_set_trace_chunk_copy(
585 viewer_session
, stream
->trace_chunk
);
592 if (stream
->trace_chunk
) {
594 * If the corresponding relay
595 * stream's trace chunk is set,
596 * the viewer stream will be
599 * Note that a relay stream can
600 * have a NULL output trace
601 * chunk (for instance, after a
602 * clear against a stopped
605 const bool reference_acquired
=
606 lttng_trace_chunk_get(
607 viewer_session
->current_trace_chunk
);
609 LTTNG_ASSERT(reference_acquired
);
610 viewer_stream_trace_chunk
=
611 viewer_session
->current_trace_chunk
;
615 viewer_stream
= viewer_stream_create(
616 stream
.get(), viewer_stream_trace_chunk
, seek_t
);
617 lttng_trace_chunk_put(viewer_stream_trace_chunk
);
618 viewer_stream_trace_chunk
= nullptr;
619 if (!viewer_stream
) {
625 * Add the new stream to the list of streams to publish for
628 pthread_mutex_lock(&viewer_session
->unannounced_stream_list_lock
);
629 cds_list_add_rcu(&viewer_stream
->viewer_stream_node
,
630 &viewer_session
->unannounced_stream_list
);
631 pthread_mutex_unlock(&viewer_session
->unannounced_stream_list_lock
);
633 * Get for the unannounced stream list, this should be
634 * put when the unannounced stream is sent.
636 if (!viewer_stream_get(viewer_stream
)) {
637 ERR("Unable to get self-reference on viewer stream");
642 /* Update number of created stream counter. */
646 * Ensure a self-reference is preserved even
647 * after we have put our local reference.
649 if (!viewer_stream_get(viewer_stream
)) {
650 ERR("Unable to get self-reference on viewer stream, logic error.");
654 if (!viewer_stream
->sent_flag
&& nb_unsent
) {
655 /* Update number of unsent stream counter. */
659 /* Update number of total stream counter. */
661 if (stream
->is_metadata
) {
662 if (!stream
->closed
||
663 stream
->metadata_received
>
664 viewer_stream
->metadata_sent
) {
668 if (!stream
->closed
||
669 !(((int64_t) (stream
->prev_data_seq
-
670 stream
->last_net_seq_num
)) >= 0)) {
675 /* Put local reference. */
676 viewer_stream_put(viewer_stream
);
686 int relayd_live_stop()
688 /* Stop dispatch thread */
689 CMM_STORE_SHARED(live_dispatch_thread_exit
, 1);
690 futex_nto1_wake(&viewer_conn_queue
.futex
);
694 static int create_sock(void *data
, int *out_fd
)
697 struct lttcomm_sock
*sock
= (lttcomm_sock
*) data
;
699 ret
= lttcomm_create_sock(sock
);
709 static int close_sock(void *data
, int *in_fd
__attribute__((unused
)))
711 struct lttcomm_sock
*sock
= (lttcomm_sock
*) data
;
713 return sock
->ops
->close(sock
);
716 static int accept_sock(void *data
, int *out_fd
)
719 /* Socks is an array of in_sock, out_sock. */
720 struct lttcomm_sock
**socks
= (lttcomm_sock
**) data
;
721 struct lttcomm_sock
*in_sock
= socks
[0];
723 socks
[1] = in_sock
->ops
->accept(in_sock
);
728 *out_fd
= socks
[1]->fd
;
733 static struct lttcomm_sock
*accept_live_sock(struct lttcomm_sock
*listening_sock
, const char *name
)
736 struct lttcomm_sock
*socks
[2] = { listening_sock
, nullptr };
737 struct lttcomm_sock
*new_sock
= nullptr;
739 ret
= fd_tracker_open_unsuspendable_fd(
740 the_fd_tracker
, &out_fd
, (const char **) &name
, 1, accept_sock
, &socks
);
745 DBG("%s accepted, socket %d", name
, new_sock
->fd
);
751 * Create and init socket from uri.
753 static struct lttcomm_sock
*init_socket(struct lttng_uri
*uri
, const char *name
)
756 struct lttcomm_sock
*sock
= nullptr;
757 char uri_str
[LTTNG_PATH_MAX
];
758 char *formated_name
= nullptr;
760 sock
= lttcomm_alloc_sock_from_uri(uri
);
761 if (sock
== nullptr) {
762 ERR("Allocating socket");
767 * Don't fail to create the socket if the name can't be built as it is
768 * only used for debugging purposes.
770 ret
= uri_to_str_url(uri
, uri_str
, sizeof(uri_str
));
771 uri_str
[sizeof(uri_str
) - 1] = '\0';
773 ret
= asprintf(&formated_name
, "%s socket @ %s", name
, uri_str
);
775 formated_name
= nullptr;
779 ret
= fd_tracker_open_unsuspendable_fd(the_fd_tracker
,
781 (const char **) (formated_name
? &formated_name
:
787 PERROR("Failed to create \"%s\" socket", formated_name
?: "Unknown");
790 DBG("Listening on %s socket %d", name
, sock
->fd
);
792 ret
= sock
->ops
->bind(sock
);
794 PERROR("Failed to bind lttng-live socket");
798 ret
= sock
->ops
->listen(sock
, -1);
808 lttcomm_destroy_sock(sock
);
815 * This thread manages the listening for new connections on the network
817 static void *thread_listener(void *data
__attribute__((unused
)))
819 int i
, ret
, err
= -1;
821 struct lttng_poll_event events
;
822 struct lttcomm_sock
*live_control_sock
;
824 DBG("[thread] Relay live listener started");
826 rcu_register_thread();
827 health_register(health_relayd
, HEALTH_RELAYD_TYPE_LIVE_LISTENER
);
829 health_code_update();
831 live_control_sock
= init_socket(live_uri
, "Live listener");
832 if (!live_control_sock
) {
833 goto error_sock_control
;
836 /* Pass 2 as size here for the thread quit pipe and control sockets. */
837 ret
= create_named_thread_poll_set(&events
, 2, "Live listener thread epoll");
839 goto error_create_poll
;
842 /* Add the control socket */
843 ret
= lttng_poll_add(&events
, live_control_sock
->fd
, LPOLLIN
| LPOLLRDHUP
);
848 lttng_relay_notify_ready();
850 if (testpoint(relayd_thread_live_listener
)) {
851 goto error_testpoint
;
855 health_code_update();
857 DBG("Listener accepting live viewers connections");
861 ret
= lttng_poll_wait(&events
, -1);
865 * Restart interrupted system call.
867 if (errno
== EINTR
) {
874 DBG("Relay new viewer connection received");
875 for (i
= 0; i
< nb_fd
; i
++) {
876 /* Fetch once the poll data */
877 const auto revents
= LTTNG_POLL_GETEV(&events
, i
);
878 const auto pollfd
= LTTNG_POLL_GETFD(&events
, i
);
880 health_code_update();
882 /* Activity on thread quit pipe, exiting. */
883 if (relayd_is_thread_quit_pipe(pollfd
)) {
884 DBG("Activity on thread quit pipe");
889 if (revents
& LPOLLIN
) {
891 * A new connection is requested, therefore a
892 * viewer connection is allocated in this
893 * thread, enqueued to a global queue and
894 * dequeued (and freed) in the worker thread.
897 struct relay_connection
*new_conn
;
898 struct lttcomm_sock
*newsock
;
900 newsock
= accept_live_sock(live_control_sock
,
901 "Live socket to client");
903 PERROR("accepting control sock");
906 DBG("Relay viewer connection accepted socket %d", newsock
->fd
);
909 newsock
->fd
, SOL_SOCKET
, SO_REUSEADDR
, &val
, sizeof(val
));
911 PERROR("setsockopt inet");
912 lttcomm_destroy_sock(newsock
);
915 new_conn
= connection_create(newsock
, RELAY_CONNECTION_UNKNOWN
);
917 lttcomm_destroy_sock(newsock
);
920 /* Ownership assumed by the connection. */
923 /* Enqueue request for the dispatcher thread. */
924 cds_wfcq_head_ptr_t head
;
925 head
.h
= &viewer_conn_queue
.head
;
926 cds_wfcq_enqueue(head
, &viewer_conn_queue
.tail
, &new_conn
->qnode
);
929 * Wake the dispatch queue futex.
930 * Implicit memory barrier with the
931 * exchange in cds_wfcq_enqueue.
933 futex_nto1_wake(&viewer_conn_queue
.futex
);
934 } else if (revents
& (LPOLLERR
| LPOLLHUP
| LPOLLRDHUP
)) {
935 ERR("socket poll error");
938 ERR("Unexpected poll events %u for sock %d", revents
, pollfd
);
948 (void) fd_tracker_util_poll_clean(the_fd_tracker
, &events
);
950 if (live_control_sock
->fd
>= 0) {
951 int sock_fd
= live_control_sock
->fd
;
953 ret
= fd_tracker_close_unsuspendable_fd(
954 the_fd_tracker
, &sock_fd
, 1, close_sock
, live_control_sock
);
958 live_control_sock
->fd
= -1;
960 lttcomm_destroy_sock(live_control_sock
);
964 DBG("Live viewer listener thread exited with error");
966 health_unregister(health_relayd
);
967 rcu_unregister_thread();
968 DBG("Live viewer listener thread cleanup complete");
969 if (lttng_relay_stop_threads()) {
970 ERR("Error stopping threads");
976 * This thread manages the dispatching of the requests to worker threads
978 static void *thread_dispatcher(void *data
__attribute__((unused
)))
982 struct cds_wfcq_node
*node
;
983 struct relay_connection
*conn
= nullptr;
985 DBG("[thread] Live viewer relay dispatcher started");
987 health_register(health_relayd
, HEALTH_RELAYD_TYPE_LIVE_DISPATCHER
);
989 if (testpoint(relayd_thread_live_dispatcher
)) {
990 goto error_testpoint
;
993 health_code_update();
996 health_code_update();
998 /* Atomically prepare the queue futex */
999 futex_nto1_prepare(&viewer_conn_queue
.futex
);
1001 if (CMM_LOAD_SHARED(live_dispatch_thread_exit
)) {
1006 health_code_update();
1008 /* Dequeue commands */
1009 node
= cds_wfcq_dequeue_blocking(&viewer_conn_queue
.head
,
1010 &viewer_conn_queue
.tail
);
1011 if (node
== nullptr) {
1012 DBG("Woken up but nothing in the live-viewer "
1013 "relay command queue");
1014 /* Continue thread execution */
1017 conn
= lttng::utils::container_of(node
, &relay_connection::qnode
);
1018 DBG("Dispatching viewer request waiting on sock %d", conn
->sock
->fd
);
1021 * Inform worker thread of the new request. This
1022 * call is blocking so we can be assured that
1023 * the data will be read at some point in time
1024 * or wait to the end of the world :)
1026 ret
= lttng_write(live_conn_pipe
[1], &conn
, sizeof(conn
)); /* NOLINT sizeof
1030 PERROR("write conn pipe");
1031 connection_put(conn
);
1034 } while (node
!= nullptr);
1036 /* Futex wait on queue. Blocking call on futex() */
1037 health_poll_entry();
1038 futex_nto1_wait(&viewer_conn_queue
.futex
);
1042 /* Normal exit, no error */
1049 ERR("Health error occurred in %s", __func__
);
1051 health_unregister(health_relayd
);
1052 DBG("Live viewer dispatch thread dying");
1053 if (lttng_relay_stop_threads()) {
1054 ERR("Error stopping threads");
1060 * Establish connection with the viewer and check the versions.
1062 * Return 0 on success or else negative value.
1064 static int viewer_connect(struct relay_connection
*conn
)
1067 struct lttng_viewer_connect reply
, msg
;
1069 conn
->version_check_done
= true;
1071 health_code_update();
1073 ret
= recv_request(conn
->sock
, &msg
, sizeof(msg
));
1078 health_code_update();
1080 memset(&reply
, 0, sizeof(reply
));
1081 reply
.major
= RELAYD_VERSION_COMM_MAJOR
;
1082 reply
.minor
= RELAYD_VERSION_COMM_MINOR
;
1084 /* Major versions must be the same */
1085 if (reply
.major
!= be32toh(msg
.major
)) {
1086 DBG("Incompatible major versions ([relayd] %u vs [client] %u)",
1088 be32toh(msg
.major
));
1093 conn
->major
= reply
.major
;
1094 /* We adapt to the lowest compatible version */
1095 if (reply
.minor
<= be32toh(msg
.minor
)) {
1096 conn
->minor
= reply
.minor
;
1098 conn
->minor
= be32toh(msg
.minor
);
1101 if (be32toh(msg
.type
) == LTTNG_VIEWER_CLIENT_COMMAND
) {
1102 conn
->type
= RELAY_VIEWER_COMMAND
;
1103 } else if (be32toh(msg
.type
) == LTTNG_VIEWER_CLIENT_NOTIFICATION
) {
1104 conn
->type
= RELAY_VIEWER_NOTIFICATION
;
1106 ERR("Unknown connection type : %u", be32toh(msg
.type
));
1111 reply
.major
= htobe32(reply
.major
);
1112 reply
.minor
= htobe32(reply
.minor
);
1113 if (conn
->type
== RELAY_VIEWER_COMMAND
) {
1115 * Increment outside of htobe64 macro, because the argument can
1116 * be used more than once within the macro, and thus the
1117 * operation may be undefined.
1119 pthread_mutex_lock(&last_relay_viewer_session_id_lock
);
1120 last_relay_viewer_session_id
++;
1121 pthread_mutex_unlock(&last_relay_viewer_session_id_lock
);
1122 reply
.viewer_session_id
= htobe64(last_relay_viewer_session_id
);
1125 health_code_update();
1127 ret
= send_response(conn
->sock
, &reply
, sizeof(reply
));
1132 health_code_update();
1134 DBG("Version check done using protocol %u.%u", conn
->major
, conn
->minor
);
1142 * Send the viewer the list of current sessions.
1143 * We need to create a copy of the hash table content because otherwise
1144 * we cannot assume the number of entries stays the same between getting
1145 * the number of HT elements and iteration over the HT.
1147 * Return 0 on success or else a negative value.
1149 static int viewer_list_sessions(struct relay_connection
*conn
)
1152 struct lttng_viewer_list_sessions session_list
;
1153 struct lttng_viewer_session
*send_session_buf
= nullptr;
1154 uint32_t buf_count
= SESSION_BUF_DEFAULT_COUNT
;
1157 send_session_buf
= calloc
<lttng_viewer_session
>(SESSION_BUF_DEFAULT_COUNT
);
1158 if (!send_session_buf
) {
1162 for (auto *session
:
1163 lttng::urcu::lfht_iteration_adapter
<relay_session
,
1164 decltype(relay_session::session_n
),
1165 &relay_session::session_n
>(*sessions_ht
->ht
)) {
1166 struct lttng_viewer_session
*send_session
;
1168 health_code_update();
1170 pthread_mutex_lock(&session
->lock
);
1171 if (session
->connection_closed
) {
1172 /* Skip closed session */
1176 if (count
>= buf_count
) {
1177 struct lttng_viewer_session
*newbuf
;
1178 const uint32_t new_buf_count
= buf_count
<< 1;
1180 newbuf
= (lttng_viewer_session
*) realloc(
1181 send_session_buf
, new_buf_count
* sizeof(*send_session_buf
));
1186 send_session_buf
= newbuf
;
1187 buf_count
= new_buf_count
;
1189 send_session
= &send_session_buf
[count
];
1190 if (lttng_strncpy(send_session
->session_name
,
1191 session
->session_name
,
1192 sizeof(send_session
->session_name
))) {
1196 if (lttng_strncpy(send_session
->hostname
,
1198 sizeof(send_session
->hostname
))) {
1202 send_session
->id
= htobe64(session
->id
);
1203 send_session
->live_timer
= htobe32(session
->live_timer
);
1204 if (session
->viewer_attached
) {
1205 send_session
->clients
= htobe32(1);
1207 send_session
->clients
= htobe32(0);
1209 send_session
->streams
= htobe32(session
->stream_count
);
1212 pthread_mutex_unlock(&session
->lock
);
1215 pthread_mutex_unlock(&session
->lock
);
1223 session_list
.sessions_count
= htobe32(count
);
1225 health_code_update();
1227 ret
= send_response(conn
->sock
, &session_list
, sizeof(session_list
));
1232 health_code_update();
1234 ret
= send_response(conn
->sock
, send_session_buf
, count
* sizeof(*send_session_buf
));
1238 health_code_update();
1242 free(send_session_buf
);
1247 * Send the viewer the list of current streams.
1249 static int viewer_get_new_streams(struct relay_connection
*conn
)
1251 int ret
, send_streams
= 0;
1252 unsigned int nb_created
= 0, nb_unsent
= 0, nb_streams
= 0, nb_total
= 0;
1253 struct lttng_viewer_new_streams_request request
;
1254 struct lttng_viewer_new_streams_response response
;
1255 struct relay_session
*session
= nullptr;
1256 uint64_t session_id
;
1257 bool closed
= false;
1261 health_code_update();
1263 /* Receive the request from the connected client. */
1264 ret
= recv_request(conn
->sock
, &request
, sizeof(request
));
1268 session_id
= be64toh(request
.session_id
);
1270 health_code_update();
1272 memset(&response
, 0, sizeof(response
));
1274 session
= session_get_by_id(session_id
);
1276 DBG("Relay session %" PRIu64
" not found", session_id
);
1277 response
.status
= htobe32(LTTNG_VIEWER_NEW_STREAMS_ERR
);
1281 if (!viewer_session_is_attached(conn
->viewer_session
, session
)) {
1282 response
.status
= htobe32(LTTNG_VIEWER_NEW_STREAMS_ERR
);
1287 * For any new stream, create it with LTTNG_VIEWER_SEEK_BEGINNING since
1288 * that at this point the client is already attached to the session.Aany
1289 * initial stream will have been created with the seek type at attach
1290 * time (for now most readers use the LTTNG_VIEWER_SEEK_LAST on attach).
1291 * Otherwise any event happening in a new stream between the attach and
1292 * a call to viewer_get_new_streams will be "lost" (never received) from
1293 * the viewer's point of view.
1295 pthread_mutex_lock(&session
->lock
);
1297 * If a session rotation is ongoing, do not attempt to open any
1298 * stream, because the chunk can be in an intermediate state
1299 * due to directory renaming.
1301 if (session_has_ongoing_rotation(session
)) {
1302 DBG("Relay session %" PRIu64
" rotation ongoing", session_id
);
1303 response
.status
= htobe32(LTTNG_VIEWER_NEW_STREAMS_NO_NEW
);
1304 goto send_reply_unlock
;
1306 ret
= make_viewer_streams(session
,
1307 conn
->viewer_session
,
1308 LTTNG_VIEWER_SEEK_BEGINNING
,
1315 * This is caused by an internal error; propagate the negative
1316 * 'ret' to close the connection.
1318 response
.status
= htobe32(LTTNG_VIEWER_NEW_STREAMS_ERR
);
1319 goto send_reply_unlock
;
1322 uatomic_set(&session
->new_streams
, 0);
1324 response
.status
= htobe32(LTTNG_VIEWER_NEW_STREAMS_OK
);
1326 /* Only send back the newly created streams with the unsent ones. */
1327 nb_streams
= nb_unsent
+ nb_created
;
1328 response
.streams_count
= htobe32(nb_streams
);
1331 * If the session is closed, HUP when there are no more streams
1334 if (closed
&& nb_total
== 0) {
1336 response
.streams_count
= 0;
1337 response
.status
= htobe32(LTTNG_VIEWER_NEW_STREAMS_HUP
);
1338 goto send_reply_unlock
;
1341 pthread_mutex_unlock(&session
->lock
);
1344 health_code_update();
1345 ret
= send_response(conn
->sock
, &response
, sizeof(response
));
1347 goto end_put_session
;
1349 health_code_update();
1352 * Unknown or empty session, just return gracefully, the viewer
1353 * knows what is happening.
1355 if (!send_streams
|| !nb_streams
) {
1357 goto end_put_session
;
1361 * Send stream and *DON'T* ignore the sent flag so every viewer
1362 * streams that were not sent from that point will be sent to
1365 ret
= send_viewer_streams(conn
->sock
, session_id
, 0, conn
->viewer_session
);
1367 goto end_put_session
;
1372 session_put(session
);
1379 * Send the viewer the list of current sessions.
1381 static int viewer_attach_session(struct relay_connection
*conn
)
1383 int send_streams
= 0;
1385 unsigned int nb_streams
= 0;
1386 enum lttng_viewer_seek seek_type
;
1387 struct lttng_viewer_attach_session_request request
;
1388 struct lttng_viewer_attach_session_response response
;
1389 struct relay_session
*session
= nullptr;
1390 enum lttng_viewer_attach_return_code viewer_attach_status
;
1391 bool closed
= false;
1392 uint64_t session_id
;
1396 health_code_update();
1398 /* Receive the request from the connected client. */
1399 ret
= recv_request(conn
->sock
, &request
, sizeof(request
));
1404 session_id
= be64toh(request
.session_id
);
1406 health_code_update();
1408 memset(&response
, 0, sizeof(response
));
1410 if (!conn
->viewer_session
) {
1411 viewer_attach_status
= LTTNG_VIEWER_ATTACH_NO_SESSION
;
1412 DBG("Client trying to attach before creating a live viewer session, returning status=%s",
1413 lttng_viewer_attach_return_code_str(viewer_attach_status
));
1417 session
= session_get_by_id(session_id
);
1419 viewer_attach_status
= LTTNG_VIEWER_ATTACH_UNK
;
1420 DBG("Relay session %" PRIu64
" not found, returning status=%s",
1422 lttng_viewer_attach_return_code_str(viewer_attach_status
));
1425 DBG("Attach relay session ID %" PRIu64
" received", session_id
);
1427 pthread_mutex_lock(&session
->lock
);
1428 if (session
->live_timer
== 0) {
1429 viewer_attach_status
= LTTNG_VIEWER_ATTACH_NOT_LIVE
;
1430 DBG("Relay session ID %" PRIu64
" is not a live session, returning status=%s",
1432 lttng_viewer_attach_return_code_str(viewer_attach_status
));
1437 viewer_attach_status
= viewer_session_attach(conn
->viewer_session
, session
);
1438 if (viewer_attach_status
!= LTTNG_VIEWER_ATTACH_OK
) {
1439 DBG("Error attaching to relay session %" PRIu64
", returning status=%s",
1441 lttng_viewer_attach_return_code_str(viewer_attach_status
));
1445 switch (be32toh(request
.seek
)) {
1446 case LTTNG_VIEWER_SEEK_BEGINNING
:
1447 case LTTNG_VIEWER_SEEK_LAST
:
1448 viewer_attach_status
= LTTNG_VIEWER_ATTACH_OK
;
1449 seek_type
= (lttng_viewer_seek
) be32toh(request
.seek
);
1452 ERR("Wrong seek parameter for relay session %" PRIu64
", returning status=%s",
1454 lttng_viewer_attach_return_code_str(viewer_attach_status
));
1455 viewer_attach_status
= LTTNG_VIEWER_ATTACH_SEEK_ERR
;
1461 * If a session rotation is ongoing, do not attempt to open any
1462 * stream, because the chunk can be in an intermediate state
1463 * due to directory renaming.
1465 if (session_has_ongoing_rotation(session
)) {
1466 DBG("Relay session %" PRIu64
" rotation ongoing", session_id
);
1471 ret
= make_viewer_streams(
1472 session
, conn
->viewer_session
, seek_type
, &nb_streams
, nullptr, nullptr, &closed
);
1474 goto end_put_session
;
1476 pthread_mutex_unlock(&session
->lock
);
1477 session_put(session
);
1480 response
.streams_count
= htobe32(nb_streams
);
1482 * If the session is closed when the viewer is attaching, it
1483 * means some of the streams may have been concurrently removed,
1484 * so we don't allow the viewer to attach, even if there are
1485 * streams available.
1489 response
.streams_count
= 0;
1490 viewer_attach_status
= LTTNG_VIEWER_ATTACH_UNK
;
1491 ERR("Session %" PRIu64
" is closed, returning status=%s",
1493 lttng_viewer_attach_return_code_str(viewer_attach_status
));
1498 health_code_update();
1500 response
.status
= htobe32((uint32_t) viewer_attach_status
);
1502 ret
= send_response(conn
->sock
, &response
, sizeof(response
));
1504 goto end_put_session
;
1506 health_code_update();
1509 * Unknown or empty session, just return gracefully, the viewer
1510 * knows what is happening.
1512 if (!send_streams
|| !nb_streams
) {
1514 goto end_put_session
;
1517 /* Send stream and ignore the sent flag. */
1518 ret
= send_viewer_streams(conn
->sock
, session_id
, 1, conn
->viewer_session
);
1520 goto end_put_session
;
1525 pthread_mutex_unlock(&session
->lock
);
1526 session_put(session
);
1533 * Open the index file if needed for the given vstream.
1535 * If an index file is successfully opened, the vstream will set it as its
1536 * current index file.
1538 * Return 0 on success, a negative value on error (-ENOENT if not ready yet).
1540 * Called with rstream lock held.
1542 static int try_open_index(struct relay_viewer_stream
*vstream
, struct relay_stream
*rstream
)
1545 const uint32_t connection_major
= rstream
->trace
->session
->major
;
1546 const uint32_t connection_minor
= rstream
->trace
->session
->minor
;
1547 enum lttng_trace_chunk_status chunk_status
;
1549 if (vstream
->index_file
) {
1554 * First time, we open the index file and at least one index is ready.
1556 if (rstream
->index_received_seqcount
== 0 || !vstream
->stream_file
.trace_chunk
) {
1561 chunk_status
= lttng_index_file_create_from_trace_chunk_read_only(
1562 vstream
->stream_file
.trace_chunk
,
1564 rstream
->channel_name
,
1565 rstream
->tracefile_size
,
1566 vstream
->current_tracefile_id
,
1567 lttng_to_index_major(connection_major
, connection_minor
),
1568 lttng_to_index_minor(connection_major
, connection_minor
),
1570 &vstream
->index_file
);
1571 if (chunk_status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
1572 if (chunk_status
== LTTNG_TRACE_CHUNK_STATUS_NO_FILE
) {
1584 * Check the status of the index for the given stream. This function
1585 * updates the index structure if needed and can put (close) the vstream
1586 * in the HUP situation.
1588 * Return 0 means that we can proceed with the index. A value of 1 means
1589 * that the index has been updated and is ready to be sent to the
1590 * client. A negative value indicates an error that can't be handled.
1592 * Called with rstream lock held.
1594 static int check_index_status(struct relay_viewer_stream
*vstream
,
1595 struct relay_stream
*rstream
,
1596 struct ctf_trace
*trace
,
1597 struct lttng_viewer_index
*index
)
1601 DBG("Check index status: index_received_seqcount %" PRIu64
" "
1602 "index_sent_seqcount %" PRIu64
" "
1603 "for stream %" PRIu64
,
1604 rstream
->index_received_seqcount
,
1605 vstream
->index_sent_seqcount
,
1606 vstream
->stream
->stream_handle
);
1607 if ((trace
->session
->connection_closed
|| rstream
->closed
) &&
1608 rstream
->index_received_seqcount
== vstream
->index_sent_seqcount
) {
1610 * Last index sent and session connection or relay
1611 * stream are closed.
1613 index
->status
= LTTNG_VIEWER_INDEX_HUP
;
1614 DBG("Check index status: Connection or stream are closed, stream %" PRIu64
1615 ",connection-closed=%d, relay-stream-closed=%d, returning status=%s",
1616 vstream
->stream
->stream_handle
,
1617 trace
->session
->connection_closed
,
1619 lttng_viewer_next_index_return_code_str(
1620 (enum lttng_viewer_next_index_return_code
) index
->status
));
1622 } else if (rstream
->beacon_ts_end
!= -1ULL &&
1623 (rstream
->index_received_seqcount
== 0 ||
1624 (vstream
->index_sent_seqcount
!= 0 &&
1625 rstream
->index_received_seqcount
<= vstream
->index_sent_seqcount
))) {
1627 * We've received a synchronization beacon and the last index
1628 * available has been sent, the index for now is inactive.
1630 * In this case, we have received a beacon which allows us to
1631 * inform the client of a time interval during which we can
1632 * guarantee that there are no events to read (and never will
1635 * The sent seqcount can grow higher than receive seqcount on
1636 * clear because the rotation performed by clear will push
1637 * the index_sent_seqcount ahead (see
1638 * viewer_stream_sync_tracefile_array_tail) and skip over
1639 * packet sequence numbers.
1641 index
->status
= LTTNG_VIEWER_INDEX_INACTIVE
;
1642 index
->timestamp_end
= htobe64(rstream
->beacon_ts_end
);
1643 index
->stream_id
= htobe64(rstream
->ctf_stream_id
);
1644 DBG("Check index status: inactive with beacon, for stream %" PRIu64
1645 ", returning status=%s",
1646 vstream
->stream
->stream_handle
,
1647 lttng_viewer_next_index_return_code_str(
1648 (enum lttng_viewer_next_index_return_code
) index
->status
));
1650 } else if (rstream
->index_received_seqcount
== 0 ||
1651 (vstream
->index_sent_seqcount
!= 0 &&
1652 rstream
->index_received_seqcount
<= vstream
->index_sent_seqcount
)) {
1654 * This checks whether received <= sent seqcount. In
1655 * this case, we have not received a beacon. Therefore,
1656 * we can only ask the client to retry later.
1658 * The sent seqcount can grow higher than receive seqcount on
1659 * clear because the rotation performed by clear will push
1660 * the index_sent_seqcount ahead (see
1661 * viewer_stream_sync_tracefile_array_tail) and skip over
1662 * packet sequence numbers.
1664 index
->status
= LTTNG_VIEWER_INDEX_RETRY
;
1665 DBG("Check index status:"
1666 "did not received beacon for stream %" PRIu64
", returning status=%s",
1667 vstream
->stream
->stream_handle
,
1668 lttng_viewer_next_index_return_code_str(
1669 (enum lttng_viewer_next_index_return_code
) index
->status
));
1671 } else if (!tracefile_array_seq_in_file(rstream
->tfa
,
1672 vstream
->current_tracefile_id
,
1673 vstream
->index_sent_seqcount
)) {
1675 * The next index we want to send cannot be read either
1676 * because we need to perform a rotation, or due to
1677 * the producer having overwritten its trace file.
1679 DBG("Viewer stream %" PRIu64
" rotation", vstream
->stream
->stream_handle
);
1680 ret
= viewer_stream_rotate(vstream
);
1682 /* EOF across entire stream. */
1683 index
->status
= LTTNG_VIEWER_INDEX_HUP
;
1684 DBG("Check index status:"
1685 "reached end of file for stream %" PRIu64
", returning status=%s",
1686 vstream
->stream
->stream_handle
,
1687 lttng_viewer_next_index_return_code_str(
1688 (enum lttng_viewer_next_index_return_code
) index
->status
));
1692 * If we have been pushed due to overwrite, it
1693 * necessarily means there is data that can be read in
1694 * the stream. If we rotated because we reached the end
1695 * of a tracefile, it means the following tracefile
1696 * needs to contain at least one index, else we would
1697 * have already returned LTTNG_VIEWER_INDEX_RETRY to the
1698 * viewer. The updated index_sent_seqcount needs to
1699 * point to a readable index entry now.
1701 * In the case where we "rotate" on a single file, we
1702 * can end up in a case where the requested index is
1703 * still unavailable.
1705 if (rstream
->tracefile_count
== 1 &&
1706 !tracefile_array_seq_in_file(rstream
->tfa
,
1707 vstream
->current_tracefile_id
,
1708 vstream
->index_sent_seqcount
)) {
1709 index
->status
= LTTNG_VIEWER_INDEX_RETRY
;
1710 DBG("Check index status:"
1711 "tracefile array sequence number %" PRIu64
1712 " not in file for stream %" PRIu64
", returning status=%s",
1713 vstream
->index_sent_seqcount
,
1714 vstream
->stream
->stream_handle
,
1715 lttng_viewer_next_index_return_code_str(
1716 (enum lttng_viewer_next_index_return_code
) index
->status
));
1719 LTTNG_ASSERT(tracefile_array_seq_in_file(
1720 rstream
->tfa
, vstream
->current_tracefile_id
, vstream
->index_sent_seqcount
));
1722 /* ret == 0 means successful so we continue. */
1727 viewer_stream_put(vstream
);
1732 static void viewer_stream_rotate_to_trace_chunk(struct relay_viewer_stream
*vstream
,
1733 struct lttng_trace_chunk
*new_trace_chunk
)
1735 lttng_trace_chunk_put(vstream
->stream_file
.trace_chunk
);
1737 if (new_trace_chunk
) {
1738 const bool acquired_reference
= lttng_trace_chunk_get(new_trace_chunk
);
1740 LTTNG_ASSERT(acquired_reference
);
1743 vstream
->stream_file
.trace_chunk
= new_trace_chunk
;
1744 viewer_stream_sync_tracefile_array_tail(vstream
);
1745 viewer_stream_close_files(vstream
);
1749 * Send the next index for a stream.
1751 * Return 0 on success or else a negative value.
1753 static int viewer_get_next_index(struct relay_connection
*conn
)
1756 struct lttng_viewer_get_next_index request_index
;
1757 struct lttng_viewer_index viewer_index
;
1758 struct ctf_packet_index packet_index
;
1759 struct relay_viewer_stream
*vstream
= nullptr;
1760 struct relay_stream
*rstream
= nullptr;
1761 struct ctf_trace
*ctf_trace
= nullptr;
1762 struct relay_viewer_stream
*metadata_viewer_stream
= nullptr;
1763 bool viewer_stream_and_session_in_same_chunk
, viewer_stream_one_rotation_behind
;
1764 uint64_t stream_file_chunk_id
= -1ULL, viewer_session_chunk_id
= -1ULL;
1765 enum lttng_trace_chunk_status status
;
1766 bool attached_sessions_have_new_streams
= false;
1770 memset(&viewer_index
, 0, sizeof(viewer_index
));
1771 health_code_update();
1773 ret
= recv_request(conn
->sock
, &request_index
, sizeof(request_index
));
1777 health_code_update();
1779 vstream
= viewer_stream_get_by_id(be64toh(request_index
.stream_id
));
1781 viewer_index
.status
= LTTNG_VIEWER_INDEX_ERR
;
1782 DBG("Client requested index of unknown stream id %" PRIu64
", returning status=%s",
1783 (uint64_t) be64toh(request_index
.stream_id
),
1784 lttng_viewer_next_index_return_code_str(
1785 (enum lttng_viewer_next_index_return_code
) viewer_index
.status
));
1789 /* Use back. ref. Protected by refcounts. */
1790 rstream
= vstream
->stream
;
1791 ctf_trace
= rstream
->trace
;
1793 /* metadata_viewer_stream may be NULL. */
1794 metadata_viewer_stream
= ctf_trace_get_viewer_metadata_stream(ctf_trace
);
1797 * Hold the session lock to protect against concurrent changes
1798 * to the chunk files (e.g. rename done by clear), which are
1799 * protected by the session ongoing rotation state. Those are
1800 * synchronized with the session lock.
1802 pthread_mutex_lock(&rstream
->trace
->session
->lock
);
1803 pthread_mutex_lock(&rstream
->lock
);
1806 * The viewer should not ask for index on metadata stream.
1808 if (rstream
->is_metadata
) {
1809 viewer_index
.status
= LTTNG_VIEWER_INDEX_HUP
;
1810 DBG("Client requested index of a metadata stream id %" PRIu64
1811 ", returning status=%s",
1812 (uint64_t) be64toh(request_index
.stream_id
),
1813 lttng_viewer_next_index_return_code_str(
1814 (enum lttng_viewer_next_index_return_code
) viewer_index
.status
));
1818 ret
= check_new_streams(conn
);
1820 viewer_index
.status
= LTTNG_VIEWER_INDEX_ERR
;
1821 ERR("Error checking for new streams in the attached sessions, returning status=%s",
1822 lttng_viewer_next_index_return_code_str(
1823 (enum lttng_viewer_next_index_return_code
) viewer_index
.status
));
1825 } else if (ret
== 1) {
1826 attached_sessions_have_new_streams
= true;
1829 if (rstream
->ongoing_rotation
.is_set
) {
1830 /* Rotation is ongoing, try again later. */
1831 viewer_index
.status
= LTTNG_VIEWER_INDEX_RETRY
;
1832 DBG("Client requested index for stream id %" PRIu64
1833 " while a stream rotation is ongoing, returning status=%s",
1834 (uint64_t) be64toh(request_index
.stream_id
),
1835 lttng_viewer_next_index_return_code_str(
1836 (enum lttng_viewer_next_index_return_code
) viewer_index
.status
));
1840 if (session_has_ongoing_rotation(rstream
->trace
->session
)) {
1841 /* Rotation is ongoing, try again later. */
1842 viewer_index
.status
= LTTNG_VIEWER_INDEX_RETRY
;
1843 DBG("Client requested index for stream id %" PRIu64
1844 " while a session rotation is ongoing, returning status=%s",
1845 (uint64_t) be64toh(request_index
.stream_id
),
1846 lttng_viewer_next_index_return_code_str(
1847 (enum lttng_viewer_next_index_return_code
) viewer_index
.status
));
1852 * Transition the viewer session into the newest trace chunk available.
1854 if (!lttng_trace_chunk_ids_equal(conn
->viewer_session
->current_trace_chunk
,
1855 rstream
->trace_chunk
)) {
1856 DBG("Relay stream and viewer chunk ids differ");
1858 ret
= viewer_session_set_trace_chunk_copy(conn
->viewer_session
,
1859 rstream
->trace_chunk
);
1861 viewer_index
.status
= LTTNG_VIEWER_INDEX_ERR
;
1862 ERR("Error copying trace chunk for stream id %" PRIu64
1863 ", returning status=%s",
1864 (uint64_t) be64toh(request_index
.stream_id
),
1865 lttng_viewer_next_index_return_code_str(
1866 (enum lttng_viewer_next_index_return_code
) viewer_index
.status
));
1872 * Transition the viewer stream into the latest trace chunk available.
1874 * Note that the stream must _not_ rotate in one precise condition:
1875 * the relay stream has rotated to a NULL trace chunk and the viewer
1876 * stream is consuming the trace chunk that was active just before
1877 * that rotation to NULL.
1879 * This allows clients to consume all the packets of a trace chunk
1880 * after a session's destruction.
1882 if (vstream
->stream_file
.trace_chunk
) {
1883 status
= lttng_trace_chunk_get_id(vstream
->stream_file
.trace_chunk
,
1884 &stream_file_chunk_id
);
1885 LTTNG_ASSERT(status
== LTTNG_TRACE_CHUNK_STATUS_OK
);
1887 if (conn
->viewer_session
->current_trace_chunk
) {
1888 status
= lttng_trace_chunk_get_id(conn
->viewer_session
->current_trace_chunk
,
1889 &viewer_session_chunk_id
);
1890 LTTNG_ASSERT(status
== LTTNG_TRACE_CHUNK_STATUS_OK
);
1893 viewer_stream_and_session_in_same_chunk
= lttng_trace_chunk_ids_equal(
1894 conn
->viewer_session
->current_trace_chunk
, vstream
->stream_file
.trace_chunk
);
1895 viewer_stream_one_rotation_behind
= rstream
->completed_rotation_count
==
1896 vstream
->last_seen_rotation_count
+ 1;
1898 if (viewer_stream_and_session_in_same_chunk
) {
1899 DBG("Transition to latest chunk check (%s -> %s): Same chunk, no need to rotate",
1900 vstream
->stream_file
.trace_chunk
?
1901 std::to_string(stream_file_chunk_id
).c_str() :
1903 conn
->viewer_session
->current_trace_chunk
?
1904 std::to_string(viewer_session_chunk_id
).c_str() :
1906 } else if (viewer_stream_one_rotation_behind
&& !rstream
->trace_chunk
) {
1907 DBG("Transition to latest chunk check (%s -> %s): One chunk behind relay stream which is being destroyed, no need to rotate",
1908 vstream
->stream_file
.trace_chunk
?
1909 std::to_string(stream_file_chunk_id
).c_str() :
1911 conn
->viewer_session
->current_trace_chunk
?
1912 std::to_string(viewer_session_chunk_id
).c_str() :
1914 } else if (vstream
->stream_file
.trace_chunk
&&
1915 rstream
->completed_rotation_count
== vstream
->last_seen_rotation_count
&&
1916 !rstream
->trace_chunk
) {
1918 * When a relay stream is closed, there is a window before the rotation of the
1919 * streams happens, during which the next index may be fetched. If the seen
1920 * rotations are the same and the relay stream trace chunk is null, don't rotate.
1921 * When the close finishes, the rotation count on the relay stream will go up.
1923 DBG("Transition to latest chunk check (%s -> %s): relay stream chunk is null, but viewer stream knows a chunk and isn't yet behind a rotation",
1924 vstream
->stream_file
.trace_chunk
?
1925 std::to_string(stream_file_chunk_id
).c_str() :
1927 conn
->viewer_session
->current_trace_chunk
?
1928 std::to_string(viewer_session_chunk_id
).c_str() :
1931 DBG("Transition to latest chunk check (%s -> %s): Viewer stream chunk ID and viewer session chunk ID differ, rotating viewer stream",
1932 vstream
->stream_file
.trace_chunk
?
1933 std::to_string(stream_file_chunk_id
).c_str() :
1935 conn
->viewer_session
->current_trace_chunk
?
1936 std::to_string(viewer_session_chunk_id
).c_str() :
1939 viewer_stream_rotate_to_trace_chunk(vstream
,
1940 conn
->viewer_session
->current_trace_chunk
);
1941 vstream
->last_seen_rotation_count
= rstream
->completed_rotation_count
;
1944 ret
= check_index_status(vstream
, rstream
, ctf_trace
, &viewer_index
);
1947 } else if (ret
== 1) {
1949 * We have no index to send and check_index_status has populated
1950 * viewer_index's status.
1955 /* At this point, ret is 0 thus we will be able to read the index. */
1958 /* Try to open an index if one is needed for that stream. */
1959 ret
= try_open_index(vstream
, rstream
);
1960 if (ret
== -ENOENT
) {
1961 if (rstream
->closed
) {
1962 viewer_index
.status
= LTTNG_VIEWER_INDEX_HUP
;
1963 DBG("Cannot open index for stream id %" PRIu64
1964 " stream is closed, returning status=%s",
1965 (uint64_t) be64toh(request_index
.stream_id
),
1966 lttng_viewer_next_index_return_code_str(
1967 (enum lttng_viewer_next_index_return_code
) viewer_index
.status
));
1970 viewer_index
.status
= LTTNG_VIEWER_INDEX_RETRY
;
1971 DBG("Cannot open index for stream id %" PRIu64
", returning status=%s",
1972 (uint64_t) be64toh(request_index
.stream_id
),
1973 lttng_viewer_next_index_return_code_str(
1974 (enum lttng_viewer_next_index_return_code
) viewer_index
.status
));
1979 viewer_index
.status
= LTTNG_VIEWER_INDEX_ERR
;
1980 ERR("Error opening index for stream id %" PRIu64
", returning status=%s",
1981 (uint64_t) be64toh(request_index
.stream_id
),
1982 lttng_viewer_next_index_return_code_str(
1983 (enum lttng_viewer_next_index_return_code
) viewer_index
.status
));
1988 * vstream->stream_fd may be NULL if it has been closed by
1989 * tracefile rotation, or if we are at the beginning of the
1990 * stream. We open the data stream file here to protect against
1991 * overwrite caused by tracefile rotation (in association with
1992 * unlink performed before overwrite).
1994 if (!vstream
->stream_file
.handle
) {
1995 char file_path
[LTTNG_PATH_MAX
];
1996 struct fs_handle
*fs_handle
;
1998 ret
= utils_stream_file_path(rstream
->path_name
,
1999 rstream
->channel_name
,
2000 rstream
->tracefile_size
,
2001 vstream
->current_tracefile_id
,
2010 * It is possible the the file we are trying to open is
2011 * missing if the stream has been closed (application exits with
2012 * per-pid buffers) and a clear command has been performed.
2014 status
= lttng_trace_chunk_open_fs_handle(
2015 vstream
->stream_file
.trace_chunk
, file_path
, O_RDONLY
, 0, &fs_handle
, true);
2016 if (status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
2017 if (status
== LTTNG_TRACE_CHUNK_STATUS_NO_FILE
&& rstream
->closed
) {
2018 viewer_index
.status
= LTTNG_VIEWER_INDEX_HUP
;
2019 DBG("Cannot find trace chunk file and stream is closed for stream id %" PRIu64
2020 ", returning status=%s",
2021 (uint64_t) be64toh(request_index
.stream_id
),
2022 lttng_viewer_next_index_return_code_str(
2023 (enum lttng_viewer_next_index_return_code
)
2024 viewer_index
.status
));
2027 PERROR("Failed to open trace file for viewer stream");
2030 vstream
->stream_file
.handle
= fs_handle
;
2033 ret
= lttng_index_file_read(vstream
->index_file
, &packet_index
);
2035 viewer_index
.status
= LTTNG_VIEWER_INDEX_ERR
;
2036 ERR("Relay error reading index file for stream id %" PRIu64
", returning status=%s",
2037 (uint64_t) be64toh(request_index
.stream_id
),
2038 lttng_viewer_next_index_return_code_str(
2039 (enum lttng_viewer_next_index_return_code
) viewer_index
.status
));
2042 viewer_index
.status
= LTTNG_VIEWER_INDEX_OK
;
2043 DBG("Read index file for stream id %" PRIu64
", returning status=%s",
2044 (uint64_t) be64toh(request_index
.stream_id
),
2045 lttng_viewer_next_index_return_code_str(
2046 (enum lttng_viewer_next_index_return_code
) viewer_index
.status
));
2047 vstream
->index_sent_seqcount
++;
2051 * Indexes are stored in big endian, no need to switch before sending.
2053 DBG("Sending viewer index for stream %" PRIu64
" offset %" PRIu64
,
2054 rstream
->stream_handle
,
2055 (uint64_t) be64toh(packet_index
.offset
));
2056 viewer_index
.offset
= packet_index
.offset
;
2057 viewer_index
.packet_size
= packet_index
.packet_size
;
2058 viewer_index
.content_size
= packet_index
.content_size
;
2059 viewer_index
.timestamp_begin
= packet_index
.timestamp_begin
;
2060 viewer_index
.timestamp_end
= packet_index
.timestamp_end
;
2061 viewer_index
.events_discarded
= packet_index
.events_discarded
;
2062 viewer_index
.stream_id
= packet_index
.stream_id
;
2066 pthread_mutex_unlock(&rstream
->lock
);
2067 pthread_mutex_unlock(&rstream
->trace
->session
->lock
);
2070 if (metadata_viewer_stream
) {
2071 pthread_mutex_lock(&metadata_viewer_stream
->stream
->lock
);
2072 DBG("get next index metadata check: recv %" PRIu64
" sent %" PRIu64
,
2073 metadata_viewer_stream
->stream
->metadata_received
,
2074 metadata_viewer_stream
->metadata_sent
);
2075 if (!metadata_viewer_stream
->stream
->metadata_received
||
2076 metadata_viewer_stream
->stream
->metadata_received
>
2077 metadata_viewer_stream
->metadata_sent
) {
2078 viewer_index
.flags
|= LTTNG_VIEWER_FLAG_NEW_METADATA
;
2080 pthread_mutex_unlock(&metadata_viewer_stream
->stream
->lock
);
2083 if (attached_sessions_have_new_streams
) {
2084 viewer_index
.flags
|= LTTNG_VIEWER_FLAG_NEW_STREAM
;
2087 viewer_index
.flags
= htobe32(viewer_index
.flags
);
2088 viewer_index
.status
= htobe32(viewer_index
.status
);
2089 health_code_update();
2091 ret
= send_response(conn
->sock
, &viewer_index
, sizeof(viewer_index
));
2095 health_code_update();
2098 DBG("Index %" PRIu64
" for stream %" PRIu64
" sent",
2099 vstream
->index_sent_seqcount
,
2100 vstream
->stream
->stream_handle
);
2103 if (metadata_viewer_stream
) {
2104 viewer_stream_put(metadata_viewer_stream
);
2107 viewer_stream_put(vstream
);
2112 pthread_mutex_unlock(&rstream
->lock
);
2113 pthread_mutex_unlock(&rstream
->trace
->session
->lock
);
2114 if (metadata_viewer_stream
) {
2115 viewer_stream_put(metadata_viewer_stream
);
2117 viewer_stream_put(vstream
);
2122 * Send the next index for a stream
2124 * Return 0 on success or else a negative value.
2126 static int viewer_get_packet(struct relay_connection
*conn
)
2130 char *reply
= nullptr;
2131 struct lttng_viewer_get_packet get_packet_info
;
2132 struct lttng_viewer_trace_packet reply_header
;
2133 struct relay_viewer_stream
*vstream
= nullptr;
2134 uint32_t reply_size
= sizeof(reply_header
);
2135 uint32_t packet_data_len
= 0;
2138 enum lttng_viewer_get_packet_return_code get_packet_status
;
2140 health_code_update();
2142 ret
= recv_request(conn
->sock
, &get_packet_info
, sizeof(get_packet_info
));
2146 health_code_update();
2148 /* From this point on, the error label can be reached. */
2149 memset(&reply_header
, 0, sizeof(reply_header
));
2150 stream_id
= (uint64_t) be64toh(get_packet_info
.stream_id
);
2152 vstream
= viewer_stream_get_by_id(stream_id
);
2154 get_packet_status
= LTTNG_VIEWER_GET_PACKET_ERR
;
2155 DBG("Client requested packet of unknown stream id %" PRIu64
", returning status=%s",
2157 lttng_viewer_get_packet_return_code_str(get_packet_status
));
2158 goto send_reply_nolock
;
2160 packet_data_len
= be32toh(get_packet_info
.len
);
2161 reply_size
+= packet_data_len
;
2164 reply
= zmalloc
<char>(reply_size
);
2166 get_packet_status
= LTTNG_VIEWER_GET_PACKET_ERR
;
2167 PERROR("Falled to allocate reply, returning status=%s",
2168 lttng_viewer_get_packet_return_code_str(get_packet_status
));
2172 pthread_mutex_lock(&vstream
->stream
->lock
);
2173 lseek_ret
= fs_handle_seek(
2174 vstream
->stream_file
.handle
, be64toh(get_packet_info
.offset
), SEEK_SET
);
2175 if (lseek_ret
< 0) {
2176 get_packet_status
= LTTNG_VIEWER_GET_PACKET_ERR
;
2177 PERROR("Failed to seek file system handle of viewer stream %" PRIu64
2178 " to offset %" PRIu64
", returning status=%s",
2180 (uint64_t) be64toh(get_packet_info
.offset
),
2181 lttng_viewer_get_packet_return_code_str(get_packet_status
));
2184 read_len
= fs_handle_read(
2185 vstream
->stream_file
.handle
, reply
+ sizeof(reply_header
), packet_data_len
);
2186 if (read_len
< packet_data_len
) {
2187 get_packet_status
= LTTNG_VIEWER_GET_PACKET_ERR
;
2188 PERROR("Failed to read from file system handle of viewer stream id %" PRIu64
2189 ", offset: %" PRIu64
", returning status=%s",
2191 (uint64_t) be64toh(get_packet_info
.offset
),
2192 lttng_viewer_get_packet_return_code_str(get_packet_status
));
2196 get_packet_status
= LTTNG_VIEWER_GET_PACKET_OK
;
2197 reply_header
.len
= htobe32(packet_data_len
);
2201 /* No payload to send on error. */
2202 reply_size
= sizeof(reply_header
);
2206 pthread_mutex_unlock(&vstream
->stream
->lock
);
2210 health_code_update();
2212 reply_header
.status
= htobe32(get_packet_status
);
2214 memcpy(reply
, &reply_header
, sizeof(reply_header
));
2215 ret
= send_response(conn
->sock
, reply
, reply_size
);
2217 /* No reply to send. */
2218 ret
= send_response(conn
->sock
, &reply_header
, reply_size
);
2221 health_code_update();
2223 PERROR("sendmsg of packet data failed");
2227 DBG("Sent %u bytes for stream %" PRIu64
, reply_size
, stream_id
);
2233 viewer_stream_put(vstream
);
2239 * Send the session's metadata
2241 * Return 0 on success else a negative value.
2243 static int viewer_get_metadata(struct relay_connection
*conn
)
2249 char *data
= nullptr;
2250 struct lttng_viewer_get_metadata request
;
2251 struct lttng_viewer_metadata_packet reply
;
2252 struct relay_viewer_stream
*vstream
= nullptr;
2253 bool dispose_of_stream
= false;
2257 health_code_update();
2259 ret
= recv_request(conn
->sock
, &request
, sizeof(request
));
2263 health_code_update();
2265 memset(&reply
, 0, sizeof(reply
));
2267 vstream
= viewer_stream_get_by_id(be64toh(request
.stream_id
));
2270 * The metadata stream can be closed by a CLOSE command
2271 * just before we attach. It can also be closed by
2272 * per-pid tracing during tracing. Therefore, it is
2273 * possible that we cannot find this viewer stream.
2274 * Reply back to the client with an error if we cannot
2277 DBG("Client requested metadata of unknown stream id %" PRIu64
,
2278 (uint64_t) be64toh(request
.stream_id
));
2279 reply
.status
= htobe32(LTTNG_VIEWER_METADATA_ERR
);
2283 pthread_mutex_lock(&vstream
->stream
->trace
->session
->lock
);
2284 pthread_mutex_lock(&vstream
->stream
->trace
->lock
);
2285 pthread_mutex_lock(&vstream
->stream
->lock
);
2286 if (!vstream
->stream
->is_metadata
) {
2287 ERR("Invalid metadata stream");
2291 if (vstream
->metadata_sent
>= vstream
->stream
->metadata_received
) {
2293 * Clear feature resets the metadata_received to 0 until the
2294 * same metadata is received again.
2296 reply
.status
= htobe32(LTTNG_VIEWER_NO_NEW_METADATA
);
2298 * The live viewer considers a closed 0 byte metadata stream as
2301 dispose_of_stream
= vstream
->metadata_sent
> 0 && vstream
->stream
->closed
;
2305 if (vstream
->stream
->trace_chunk
&&
2306 !lttng_trace_chunk_ids_equal(conn
->viewer_session
->current_trace_chunk
,
2307 vstream
->stream
->trace_chunk
)) {
2308 /* A rotation has occurred on the relay stream. */
2309 DBG("Metadata relay stream and viewer chunk ids differ");
2311 ret
= viewer_session_set_trace_chunk_copy(conn
->viewer_session
,
2312 vstream
->stream
->trace_chunk
);
2314 reply
.status
= htobe32(LTTNG_VIEWER_METADATA_ERR
);
2319 if (conn
->viewer_session
->current_trace_chunk
&&
2320 !lttng_trace_chunk_ids_equal(conn
->viewer_session
->current_trace_chunk
,
2321 vstream
->stream_file
.trace_chunk
)) {
2322 bool acquired_reference
;
2324 DBG("Viewer session and viewer stream chunk differ: "
2325 "vsession chunk %p vstream chunk=%p",
2326 conn
->viewer_session
->current_trace_chunk
,
2327 vstream
->stream_file
.trace_chunk
);
2328 lttng_trace_chunk_put(vstream
->stream_file
.trace_chunk
);
2329 acquired_reference
=
2330 lttng_trace_chunk_get(conn
->viewer_session
->current_trace_chunk
);
2331 LTTNG_ASSERT(acquired_reference
);
2332 vstream
->stream_file
.trace_chunk
= conn
->viewer_session
->current_trace_chunk
;
2333 viewer_stream_close_files(vstream
);
2336 len
= vstream
->stream
->metadata_received
- vstream
->metadata_sent
;
2338 if (!vstream
->stream_file
.trace_chunk
) {
2339 if (vstream
->stream
->trace
->session
->connection_closed
) {
2341 * If the connection is closed, there is no way for the metadata stream
2342 * to ever transition back to an active chunk. As such, signal to the viewer
2343 * that there is no new metadata available.
2345 * The stream can be disposed-of. On the next execution of this command,
2346 * the relay daemon will reply with an error status since the stream can't
2349 dispose_of_stream
= true;
2352 reply
.status
= htobe32(LTTNG_VIEWER_NO_NEW_METADATA
);
2355 } else if (vstream
->stream_file
.trace_chunk
&& !vstream
->stream_file
.handle
&& len
> 0) {
2357 * Either this is the first time the metadata file is read, or a
2358 * rotation of the corresponding relay stream has occurred.
2360 struct fs_handle
*fs_handle
;
2361 char file_path
[LTTNG_PATH_MAX
];
2362 enum lttng_trace_chunk_status status
;
2363 struct relay_stream
*rstream
= vstream
->stream
;
2365 ret
= utils_stream_file_path(rstream
->path_name
,
2366 rstream
->channel_name
,
2367 rstream
->tracefile_size
,
2368 vstream
->current_tracefile_id
,
2377 * It is possible the the metadata file we are trying to open is
2378 * missing if the stream has been closed (application exits with
2379 * per-pid buffers) and a clear command has been performed.
2381 status
= lttng_trace_chunk_open_fs_handle(
2382 vstream
->stream_file
.trace_chunk
, file_path
, O_RDONLY
, 0, &fs_handle
, true);
2383 if (status
!= LTTNG_TRACE_CHUNK_STATUS_OK
) {
2384 if (status
== LTTNG_TRACE_CHUNK_STATUS_NO_FILE
) {
2385 reply
.status
= htobe32(LTTNG_VIEWER_NO_NEW_METADATA
);
2387 if (vstream
->stream
->closed
) {
2388 viewer_stream_put(vstream
);
2392 PERROR("Failed to open metadata file for viewer stream");
2395 vstream
->stream_file
.handle
= fs_handle
;
2397 if (vstream
->metadata_sent
!= 0) {
2399 * The client does not expect to receive any metadata
2400 * it has received and metadata files in successive
2401 * chunks must be a strict superset of one another.
2403 * Skip the first `metadata_sent` bytes to ensure
2404 * they are not sent a second time to the client.
2406 * Baring a block layer error or an internal error,
2407 * this seek should not fail as
2408 * `vstream->stream->metadata_received` is reset when
2409 * a relay stream is rotated. If this is reached, it is
2410 * safe to assume that
2411 * `metadata_received` > `metadata_sent`.
2413 const off_t seek_ret
=
2414 fs_handle_seek(fs_handle
, vstream
->metadata_sent
, SEEK_SET
);
2417 PERROR("Failed to seek metadata viewer stream file to `sent` position: pos = %" PRId64
,
2418 vstream
->metadata_sent
);
2419 reply
.status
= htobe32(LTTNG_VIEWER_METADATA_ERR
);
2425 reply
.len
= htobe64(len
);
2426 data
= zmalloc
<char>(len
);
2428 PERROR("viewer metadata zmalloc");
2432 fd
= fs_handle_get_fd(vstream
->stream_file
.handle
);
2434 ERR("Failed to restore viewer stream file system handle");
2437 read_len
= lttng_read(fd
, data
, len
);
2438 fs_handle_put_fd(vstream
->stream_file
.handle
);
2440 if (read_len
< len
) {
2442 PERROR("Failed to read metadata file");
2446 * A clear has been performed which prevents the relay
2447 * from sending `len` bytes of metadata.
2449 * It is important not to send any metadata if we
2450 * couldn't read all the available metadata in one shot:
2451 * sending partial metadata can cause the client to
2452 * attempt to parse an incomplete (incoherent) metadata
2453 * stream, which would result in an error.
2455 const off_t seek_ret
=
2456 fs_handle_seek(vstream
->stream_file
.handle
, -read_len
, SEEK_CUR
);
2458 DBG("Failed to read metadata: requested = %" PRIu64
", got = %zd",
2464 PERROR("Failed to restore metadata file position after partial read");
2470 vstream
->metadata_sent
+= read_len
;
2471 reply
.status
= htobe32(LTTNG_VIEWER_METADATA_OK
);
2476 reply
.status
= htobe32(LTTNG_VIEWER_METADATA_ERR
);
2479 health_code_update();
2481 pthread_mutex_unlock(&vstream
->stream
->lock
);
2482 pthread_mutex_unlock(&vstream
->stream
->trace
->lock
);
2483 pthread_mutex_unlock(&vstream
->stream
->trace
->session
->lock
);
2485 ret
= send_response(conn
->sock
, &reply
, sizeof(reply
));
2489 health_code_update();
2492 ret
= send_response(conn
->sock
, data
, len
);
2498 DBG("Sent %" PRIu64
" bytes of metadata for stream %" PRIu64
,
2500 (uint64_t) be64toh(request
.stream_id
));
2502 DBG("Metadata sent");
2508 viewer_stream_put(vstream
);
2509 if (dispose_of_stream
) {
2511 * Trigger the destruction of the viewer stream
2512 * by releasing its global reference.
2514 * The live viewers expect to receive a NO_NEW_METADATA
2515 * status before a stream disappears, otherwise they abort the
2516 * entire live connection when receiving an error status.
2518 * On the next query for this stream, an error will be reported to the
2521 viewer_stream_put(vstream
);
2529 * Create a viewer session.
2531 * Return 0 on success or else a negative value.
2533 static int viewer_create_session(struct relay_connection
*conn
)
2536 struct lttng_viewer_create_session_response resp
;
2538 memset(&resp
, 0, sizeof(resp
));
2539 resp
.status
= htobe32(LTTNG_VIEWER_CREATE_SESSION_OK
);
2540 conn
->viewer_session
= viewer_session_create();
2541 if (!conn
->viewer_session
) {
2542 ERR("Allocation viewer session");
2543 resp
.status
= htobe32(LTTNG_VIEWER_CREATE_SESSION_ERR
);
2548 health_code_update();
2549 ret
= send_response(conn
->sock
, &resp
, sizeof(resp
));
2553 health_code_update();
2561 * Detach a viewer session.
2563 * Return 0 on success or else a negative value.
2565 static int viewer_detach_session(struct relay_connection
*conn
)
2568 struct lttng_viewer_detach_session_response response
;
2569 struct lttng_viewer_detach_session_request request
;
2570 struct relay_session
*session
= nullptr;
2571 uint64_t viewer_session_to_close
;
2575 health_code_update();
2577 /* Receive the request from the connected client. */
2578 ret
= recv_request(conn
->sock
, &request
, sizeof(request
));
2582 viewer_session_to_close
= be64toh(request
.session_id
);
2584 if (!conn
->viewer_session
) {
2585 DBG("Client trying to detach before creating a live viewer session");
2586 response
.status
= htobe32(LTTNG_VIEWER_DETACH_SESSION_ERR
);
2590 health_code_update();
2592 memset(&response
, 0, sizeof(response
));
2593 DBG("Detaching from session ID %" PRIu64
, viewer_session_to_close
);
2595 session
= session_get_by_id(be64toh(request
.session_id
));
2597 DBG("Relay session %" PRIu64
" not found", (uint64_t) be64toh(request
.session_id
));
2598 response
.status
= htobe32(LTTNG_VIEWER_DETACH_SESSION_UNK
);
2602 ret
= viewer_session_is_attached(conn
->viewer_session
, session
);
2604 DBG("Not attached to this session");
2605 response
.status
= htobe32(LTTNG_VIEWER_DETACH_SESSION_ERR
);
2606 goto send_reply_put
;
2609 viewer_session_close_one_session(conn
->viewer_session
, session
);
2610 response
.status
= htobe32(LTTNG_VIEWER_DETACH_SESSION_OK
);
2611 DBG("Session %" PRIu64
" detached.", viewer_session_to_close
);
2614 session_put(session
);
2617 health_code_update();
2618 ret
= send_response(conn
->sock
, &response
, sizeof(response
));
2622 health_code_update();
2630 * live_relay_unknown_command: send -1 if received unknown command
2632 static void live_relay_unknown_command(struct relay_connection
*conn
)
2634 struct lttcomm_relayd_generic_reply reply
;
2636 memset(&reply
, 0, sizeof(reply
));
2637 reply
.ret_code
= htobe32(LTTNG_ERR_UNK
);
2638 (void) send_response(conn
->sock
, &reply
, sizeof(reply
));
2642 * Process the commands received on the control socket
2644 static int process_control(struct lttng_viewer_cmd
*recv_hdr
, struct relay_connection
*conn
)
2647 const lttng_viewer_command cmd
= (lttng_viewer_command
) be32toh(recv_hdr
->cmd
);
2650 * Make sure we've done the version check before any command other then
2651 * a new client connection.
2653 if (cmd
!= LTTNG_VIEWER_CONNECT
&& !conn
->version_check_done
) {
2654 ERR("Viewer on connection %d requested %s command before version check",
2656 lttng_viewer_command_str(cmd
));
2661 DBG("Processing %s viewer command from connection %d",
2662 lttng_viewer_command_str(cmd
),
2666 case LTTNG_VIEWER_CONNECT
:
2667 ret
= viewer_connect(conn
);
2669 case LTTNG_VIEWER_LIST_SESSIONS
:
2670 ret
= viewer_list_sessions(conn
);
2672 case LTTNG_VIEWER_ATTACH_SESSION
:
2673 ret
= viewer_attach_session(conn
);
2675 case LTTNG_VIEWER_GET_NEXT_INDEX
:
2676 ret
= viewer_get_next_index(conn
);
2678 case LTTNG_VIEWER_GET_PACKET
:
2679 ret
= viewer_get_packet(conn
);
2681 case LTTNG_VIEWER_GET_METADATA
:
2682 ret
= viewer_get_metadata(conn
);
2684 case LTTNG_VIEWER_GET_NEW_STREAMS
:
2685 ret
= viewer_get_new_streams(conn
);
2687 case LTTNG_VIEWER_CREATE_SESSION
:
2688 ret
= viewer_create_session(conn
);
2690 case LTTNG_VIEWER_DETACH_SESSION
:
2691 ret
= viewer_detach_session(conn
);
2694 ERR("Received unknown viewer command (%u)", be32toh(recv_hdr
->cmd
));
2695 live_relay_unknown_command(conn
);
2704 static void cleanup_connection_pollfd(struct lttng_poll_event
*events
, int pollfd
)
2708 (void) lttng_poll_del(events
, pollfd
);
2710 ret
= fd_tracker_close_unsuspendable_fd(
2711 the_fd_tracker
, &pollfd
, 1, fd_tracker_util_close_fd
, nullptr);
2713 ERR("Closing pollfd %d", pollfd
);
2718 * This thread does the actual work
2720 static void *thread_worker(void *data
__attribute__((unused
)))
2724 struct lttng_poll_event events
;
2725 struct lttng_ht
*viewer_connections_ht
;
2726 struct lttng_viewer_cmd recv_hdr
;
2728 DBG("[thread] Live viewer relay worker started");
2730 rcu_register_thread();
2732 health_register(health_relayd
, HEALTH_RELAYD_TYPE_LIVE_WORKER
);
2734 if (testpoint(relayd_thread_live_worker
)) {
2735 goto error_testpoint
;
2738 /* table of connections indexed on socket */
2739 viewer_connections_ht
= lttng_ht_new(0, LTTNG_HT_TYPE_ULONG
);
2740 if (!viewer_connections_ht
) {
2741 goto viewer_connections_ht_error
;
2744 ret
= create_named_thread_poll_set(&events
, 2, "Live viewer worker thread epoll");
2746 goto error_poll_create
;
2749 ret
= lttng_poll_add(&events
, live_conn_pipe
[0], LPOLLIN
| LPOLLRDHUP
);
2758 health_code_update();
2760 /* Infinite blocking call, waiting for transmission */
2761 DBG3("Relayd live viewer worker thread polling...");
2762 health_poll_entry();
2763 ret
= lttng_poll_wait(&events
, -1);
2767 * Restart interrupted system call.
2769 if (errno
== EINTR
) {
2778 * Process control. The control connection is prioritised so we don't
2779 * starve it with high throughput tracing data on the data
2782 for (i
= 0; i
< nb_fd
; i
++) {
2783 /* Fetch once the poll data */
2784 const auto revents
= LTTNG_POLL_GETEV(&events
, i
);
2785 const auto pollfd
= LTTNG_POLL_GETFD(&events
, i
);
2787 health_code_update();
2789 /* Activity on thread quit pipe, exiting. */
2790 if (relayd_is_thread_quit_pipe(pollfd
)) {
2791 DBG("Activity on thread quit pipe");
2796 /* Inspect the relay conn pipe for new connection. */
2797 if (pollfd
== live_conn_pipe
[0]) {
2798 if (revents
& LPOLLIN
) {
2799 struct relay_connection
*conn
;
2801 ret
= lttng_read(live_conn_pipe
[0],
2803 sizeof(conn
)); /* NOLINT sizeof used on a
2808 ret
= lttng_poll_add(
2809 &events
, conn
->sock
->fd
, LPOLLIN
| LPOLLRDHUP
);
2811 ERR("Failed to add new live connection file descriptor to poll set");
2814 connection_ht_add(viewer_connections_ht
, conn
);
2815 DBG("Connection socket %d added to poll", conn
->sock
->fd
);
2816 } else if (revents
& (LPOLLERR
| LPOLLHUP
| LPOLLRDHUP
)) {
2817 ERR("Relay live pipe error");
2820 ERR("Unexpected poll events %u for sock %d",
2826 /* Connection activity. */
2827 struct relay_connection
*conn
;
2829 conn
= connection_get_by_sock(viewer_connections_ht
, pollfd
);
2834 if (revents
& LPOLLIN
) {
2835 ret
= conn
->sock
->ops
->recvmsg(
2836 conn
->sock
, &recv_hdr
, sizeof(recv_hdr
), 0);
2838 /* Connection closed. */
2839 cleanup_connection_pollfd(&events
, pollfd
);
2840 /* Put "create" ownership reference. */
2841 connection_put(conn
);
2842 DBG("Viewer control conn closed with %d", pollfd
);
2844 ret
= process_control(&recv_hdr
, conn
);
2846 /* Clear the session on error. */
2847 cleanup_connection_pollfd(&events
, pollfd
);
2848 /* Put "create" ownership reference. */
2849 connection_put(conn
);
2850 DBG("Viewer connection closed with %d",
2854 } else if (revents
& (LPOLLERR
| LPOLLHUP
| LPOLLRDHUP
)) {
2855 cleanup_connection_pollfd(&events
, pollfd
);
2856 /* Put "create" ownership reference. */
2857 connection_put(conn
);
2859 ERR("Unexpected poll events %u for sock %d",
2862 connection_put(conn
);
2865 /* Put local "get_by_sock" reference. */
2866 connection_put(conn
);
2873 (void) fd_tracker_util_poll_clean(the_fd_tracker
, &events
);
2875 /* Cleanup remaining connection object. */
2876 for (auto *destroy_conn
:
2877 lttng::urcu::lfht_iteration_adapter
<relay_connection
,
2878 decltype(relay_connection::sock_n
),
2879 &relay_connection::sock_n
>(
2880 *viewer_connections_ht
->ht
)) {
2881 health_code_update();
2882 connection_put(destroy_conn
);
2886 lttng_ht_destroy(viewer_connections_ht
);
2887 viewer_connections_ht_error
:
2888 /* Close relay conn pipes */
2889 (void) fd_tracker_util_pipe_close(the_fd_tracker
, live_conn_pipe
);
2891 DBG("Viewer worker thread exited with error");
2893 DBG("Viewer worker thread cleanup complete");
2897 ERR("Health error occurred in %s", __func__
);
2899 health_unregister(health_relayd
);
2900 if (lttng_relay_stop_threads()) {
2901 ERR("Error stopping threads");
2903 rcu_unregister_thread();
2908 * Create the relay command pipe to wake thread_manage_apps.
2909 * Closed in cleanup().
2911 static int create_conn_pipe()
2913 return fd_tracker_util_pipe_open_cloexec(
2914 the_fd_tracker
, "Live connection pipe", live_conn_pipe
);
2917 int relayd_live_join()
2919 int ret
, retval
= 0;
2922 ret
= pthread_join(live_listener_thread
, &status
);
2925 PERROR("pthread_join live listener");
2929 ret
= pthread_join(live_worker_thread
, &status
);
2932 PERROR("pthread_join live worker");
2936 ret
= pthread_join(live_dispatcher_thread
, &status
);
2939 PERROR("pthread_join live dispatcher");
2943 cleanup_relayd_live();
2951 int relayd_live_create(struct lttng_uri
*uri
)
2953 int ret
= 0, retval
= 0;
2959 goto exit_init_data
;
2963 /* Check if daemon is UID = 0 */
2964 is_root
= !getuid();
2967 if (live_uri
->port
< 1024) {
2968 ERR("Need to be root to use ports < 1024");
2970 goto exit_init_data
;
2974 /* Setup the thread apps communication pipe. */
2975 if (create_conn_pipe()) {
2977 goto exit_init_data
;
2980 /* Init relay command queue. */
2981 cds_wfcq_init(&viewer_conn_queue
.head
, &viewer_conn_queue
.tail
);
2983 /* Set up max poll set size */
2984 if (lttng_poll_set_max_size()) {
2986 goto exit_init_data
;
2989 /* Setup the dispatcher thread */
2990 ret
= pthread_create(&live_dispatcher_thread
,
2991 default_pthread_attr(),
2996 PERROR("pthread_create viewer dispatcher");
2998 goto exit_dispatcher_thread
;
3001 /* Setup the worker thread */
3002 ret
= pthread_create(&live_worker_thread
, default_pthread_attr(), thread_worker
, nullptr);
3005 PERROR("pthread_create viewer worker");
3007 goto exit_worker_thread
;
3010 /* Setup the listener thread */
3011 ret
= pthread_create(
3012 &live_listener_thread
, default_pthread_attr(), thread_listener
, (void *) nullptr);
3015 PERROR("pthread_create viewer listener");
3017 goto exit_listener_thread
;
3021 * All OK, started all threads.
3026 * Join on the live_listener_thread should anything be added after
3027 * the live_listener thread's creation.
3030 exit_listener_thread
:
3032 ret
= pthread_join(live_worker_thread
, &status
);
3035 PERROR("pthread_join live worker");
3040 ret
= pthread_join(live_dispatcher_thread
, &status
);
3043 PERROR("pthread_join live dispatcher");
3046 exit_dispatcher_thread
:
3049 cleanup_relayd_live();