2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
26 #include <sys/socket.h>
27 #include <sys/types.h>
32 #include <common/common.h>
33 #include <common/kernel-ctl/kernel-ctl.h>
34 #include <common/sessiond-comm/sessiond-comm.h>
35 #include <common/sessiond-comm/relayd.h>
36 #include <common/compat/fcntl.h>
37 #include <common/relayd/relayd.h>
39 #include "kernel-consumer.h"
41 extern struct lttng_consumer_global_data consumer_data
;
42 extern int consumer_poll_timeout
;
43 extern volatile int consumer_quit
;
46 * Take a snapshot for a specific fd
48 * Returns 0 on success, < 0 on error
50 int lttng_kconsumer_take_snapshot(struct lttng_consumer_local_data
*ctx
,
51 struct lttng_consumer_stream
*stream
)
54 int infd
= stream
->wait_fd
;
56 ret
= kernctl_snapshot(infd
);
59 perror("Getting sub-buffer snapshot.");
66 * Get the produced position
68 * Returns 0 on success, < 0 on error
70 int lttng_kconsumer_get_produced_snapshot(
71 struct lttng_consumer_local_data
*ctx
,
72 struct lttng_consumer_stream
*stream
,
76 int infd
= stream
->wait_fd
;
78 ret
= kernctl_snapshot_get_produced(infd
, pos
);
81 perror("kernctl_snapshot_get_produced");
87 int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data
*ctx
,
88 int sock
, struct pollfd
*consumer_sockpoll
)
91 struct lttcomm_consumer_msg msg
;
93 ret
= lttcomm_recv_unix_sock(sock
, &msg
, sizeof(msg
));
94 if (ret
!= sizeof(msg
)) {
95 lttng_consumer_send_error(ctx
, CONSUMERD_ERROR_RECV_CMD
);
98 if (msg
.cmd_type
== LTTNG_CONSUMER_STOP
) {
102 /* relayd needs RCU read-side protection */
105 switch (msg
.cmd_type
) {
106 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET
:
109 struct consumer_relayd_sock_pair
*relayd
;
111 DBG("Consumer adding relayd socket");
113 /* Get relayd reference if exists. */
114 relayd
= consumer_find_relayd(msg
.u
.relayd_sock
.net_index
);
115 if (relayd
== NULL
) {
116 /* Not found. Allocate one. */
117 relayd
= consumer_allocate_relayd_sock_pair(
118 msg
.u
.relayd_sock
.net_index
);
119 if (relayd
== NULL
) {
120 lttng_consumer_send_error(ctx
, CONSUMERD_OUTFD_ERROR
);
125 /* Poll on consumer socket. */
126 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
131 /* Get relayd socket from session daemon */
132 ret
= lttcomm_recv_fds_unix_sock(sock
, &fd
, 1);
133 if (ret
!= sizeof(fd
)) {
134 lttng_consumer_send_error(ctx
, CONSUMERD_ERROR_RECV_FD
);
138 /* Copy socket information and received FD */
139 switch (msg
.u
.relayd_sock
.type
) {
140 case LTTNG_STREAM_CONTROL
:
141 /* Copy received lttcomm socket */
142 lttcomm_copy_sock(&relayd
->control_sock
, &msg
.u
.relayd_sock
.sock
);
144 ret
= lttcomm_create_sock(&relayd
->control_sock
);
149 /* Close the created socket fd which is useless */
150 close(relayd
->control_sock
.fd
);
152 /* Assign new file descriptor */
153 relayd
->control_sock
.fd
= fd
;
155 case LTTNG_STREAM_DATA
:
156 /* Copy received lttcomm socket */
157 lttcomm_copy_sock(&relayd
->data_sock
, &msg
.u
.relayd_sock
.sock
);
158 ret
= lttcomm_create_sock(&relayd
->data_sock
);
163 /* Close the created socket fd which is useless */
164 close(relayd
->data_sock
.fd
);
166 /* Assign new file descriptor */
167 relayd
->data_sock
.fd
= fd
;
170 ERR("Unknown relayd socket type");
174 DBG("Consumer %s socket created successfully with net idx %d (fd: %d)",
175 msg
.u
.relayd_sock
.type
== LTTNG_STREAM_CONTROL
? "control" : "data",
176 relayd
->net_seq_idx
, fd
);
179 * Add relayd socket pair to consumer data hashtable. If object already
180 * exists or on error, the function gracefully returns.
182 consumer_add_relayd(relayd
);
186 case LTTNG_CONSUMER_ADD_CHANNEL
:
188 struct lttng_consumer_channel
*new_channel
;
190 DBG("consumer_add_channel %d", msg
.u
.channel
.channel_key
);
191 new_channel
= consumer_allocate_channel(msg
.u
.channel
.channel_key
,
193 msg
.u
.channel
.mmap_len
,
194 msg
.u
.channel
.max_sb_size
);
195 if (new_channel
== NULL
) {
196 lttng_consumer_send_error(ctx
, CONSUMERD_OUTFD_ERROR
);
199 if (ctx
->on_recv_channel
!= NULL
) {
200 ret
= ctx
->on_recv_channel(new_channel
);
202 consumer_add_channel(new_channel
);
203 } else if (ret
< 0) {
207 consumer_add_channel(new_channel
);
211 case LTTNG_CONSUMER_ADD_STREAM
:
214 struct consumer_relayd_sock_pair
*relayd
= NULL
;
215 struct lttng_consumer_stream
*new_stream
;
218 if (lttng_consumer_poll_socket(consumer_sockpoll
) < 0) {
223 /* Get stream file descriptor from socket */
224 ret
= lttcomm_recv_fds_unix_sock(sock
, &fd
, 1);
225 if (ret
!= sizeof(fd
)) {
226 lttng_consumer_send_error(ctx
, CONSUMERD_ERROR_RECV_FD
);
231 new_stream
= consumer_allocate_stream(msg
.u
.stream
.channel_key
,
232 msg
.u
.stream
.stream_key
,
235 msg
.u
.stream
.mmap_len
,
237 msg
.u
.stream
.path_name
,
240 msg
.u
.stream
.net_index
,
241 msg
.u
.stream
.metadata_flag
);
242 if (new_stream
== NULL
) {
243 lttng_consumer_send_error(ctx
, CONSUMERD_OUTFD_ERROR
);
247 /* The stream is not metadata. Get relayd reference if exists. */
248 relayd
= consumer_find_relayd(msg
.u
.stream
.net_index
);
249 if (relayd
!= NULL
) {
250 /* Add stream on the relayd */
251 pthread_mutex_lock(&relayd
->ctrl_sock_mutex
);
252 ret
= relayd_add_stream(&relayd
->control_sock
,
253 msg
.u
.stream
.name
, msg
.u
.stream
.path_name
,
254 &new_stream
->relayd_stream_id
);
255 pthread_mutex_unlock(&relayd
->ctrl_sock_mutex
);
259 } else if (msg
.u
.stream
.net_index
!= -1) {
260 ERR("Network sequence index %d unknown. Not adding stream.",
261 msg
.u
.stream
.net_index
);
266 if (ctx
->on_recv_stream
!= NULL
) {
267 ret
= ctx
->on_recv_stream(new_stream
);
269 consumer_add_stream(new_stream
);
270 } else if (ret
< 0) {
274 consumer_add_stream(new_stream
);
277 DBG("Kernel consumer_add_stream (%d)", fd
);
280 case LTTNG_CONSUMER_UPDATE_STREAM
:
285 case LTTNG_CONSUMER_DESTROY_RELAYD
:
287 struct consumer_relayd_sock_pair
*relayd
;
289 DBG("Kernel consumer destroying relayd %" PRIu64
,
290 msg
.u
.destroy_relayd
.net_seq_idx
);
292 /* Get relayd reference if exists. */
293 relayd
= consumer_find_relayd(msg
.u
.destroy_relayd
.net_seq_idx
);
294 if (relayd
== NULL
) {
295 ERR("Unable to find relayd %" PRIu64
,
296 msg
.u
.destroy_relayd
.net_seq_idx
);
300 /* Set destroy flag for this object */
301 uatomic_set(&relayd
->destroy_flag
, 1);
303 /* Destroy the relayd if refcount is 0 else set the destroy flag. */
304 if (uatomic_read(&relayd
->refcount
) == 0) {
305 consumer_destroy_relayd(relayd
);
314 * Wake-up the other end by writing a null byte in the pipe (non-blocking).
315 * Important note: Because writing into the pipe is non-blocking (and
316 * therefore we allow dropping wakeup data, as long as there is wakeup data
317 * present in the pipe buffer to wake up the other end), the other end
318 * should perform the following sequence for waiting:
320 * 1) empty the pipe (reads).
321 * 2) perform update operation.
322 * 3) wait on the pipe (poll).
325 ret
= write(ctx
->consumer_poll_pipe
[1], "", 1);
326 } while (ret
< 0 && errno
== EINTR
);
333 * Consume data on a file descriptor and write it on a trace file.
335 ssize_t
lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream
*stream
,
336 struct lttng_consumer_local_data
*ctx
)
341 int infd
= stream
->wait_fd
;
343 DBG("In read_subbuffer (infd : %d)", infd
);
344 /* Get the next subbuffer */
345 err
= kernctl_get_next_subbuf(infd
);
348 * This is a debug message even for single-threaded consumer,
349 * because poll() have more relaxed criterions than get subbuf,
350 * so get_subbuf may fail for short race windows where poll()
351 * would issue wakeups.
353 DBG("Reserving sub buffer failed (everything is normal, "
354 "it is due to concurrency)");
358 switch (stream
->output
) {
359 case LTTNG_EVENT_SPLICE
:
360 /* read the whole subbuffer */
361 err
= kernctl_get_padded_subbuf_size(infd
, &len
);
364 perror("Getting sub-buffer len failed.");
368 /* splice the subbuffer to the tracefile */
369 ret
= lttng_consumer_on_read_subbuffer_splice(ctx
, stream
, len
);
372 * display the error but continue processing to try
373 * to release the subbuffer
375 ERR("Error splicing to tracefile (ret: %zd != len: %lu)",
380 case LTTNG_EVENT_MMAP
:
381 /* read the used subbuffer size */
382 err
= kernctl_get_padded_subbuf_size(infd
, &len
);
385 perror("Getting sub-buffer len failed.");
388 /* write the subbuffer to the tracefile */
389 ret
= lttng_consumer_on_read_subbuffer_mmap(ctx
, stream
, len
);
392 * display the error but continue processing to try
393 * to release the subbuffer
395 ERR("Error writing to tracefile");
399 ERR("Unknown output method");
403 err
= kernctl_put_next_subbuf(infd
);
406 if (errno
== EFAULT
) {
407 perror("Error in unreserving sub buffer\n");
408 } else if (errno
== EIO
) {
409 /* Should never happen with newer LTTng versions */
410 perror("Reader has been pushed by the writer, last sub-buffer corrupted.");
419 int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream
*stream
)
423 /* Opening the tracefile in write mode */
424 if (strlen(stream
->path_name
) > 0 && stream
->net_seq_idx
== -1) {
425 ret
= run_as_open(stream
->path_name
,
426 O_WRONLY
|O_CREAT
|O_TRUNC
,
427 S_IRWXU
|S_IRWXG
|S_IRWXO
,
428 stream
->uid
, stream
->gid
);
430 ERR("Opening %s", stream
->path_name
);
434 stream
->out_fd
= ret
;
437 if (stream
->output
== LTTNG_EVENT_MMAP
) {
438 /* get the len of the mmap region */
439 unsigned long mmap_len
;
441 ret
= kernctl_get_mmap_len(stream
->wait_fd
, &mmap_len
);
444 perror("kernctl_get_mmap_len");
447 stream
->mmap_len
= (size_t) mmap_len
;
449 stream
->mmap_base
= mmap(NULL
, stream
->mmap_len
,
450 PROT_READ
, MAP_PRIVATE
, stream
->wait_fd
, 0);
451 if (stream
->mmap_base
== MAP_FAILED
) {
452 perror("Error mmaping");
458 /* we return 0 to let the library handle the FD internally */
465 err
= close(stream
->out_fd
);