src/bin/lttng-sessiond/kernel-consumer.c

   1 /*
   2  * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License, version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _LGPL_SOURCE
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <sys/stat.h>
  22 #include <unistd.h>
  23 #include <inttypes.h>
  24
  25 #include <common/common.h>
  26 #include <common/defaults.h>
  27 #include <common/compat/string.h>
  28
  29 #include "consumer.h"
  30 #include "health-sessiond.h"
  31 #include "kernel-consumer.h"
  32 #include "notification-thread-commands.h"
  33 #include "session.h"
  34 #include "lttng-sessiond.h"
  35
  36 static char *create_channel_path(struct consumer_output *consumer,
  37                 uid_t uid, gid_t gid)
  38 {
  39         int ret;
  40         char tmp_path[PATH_MAX];
  41         char *pathname = NULL;
  42
  43         assert(consumer);
  44
  45         /* Get the right path name destination */
  46         if (consumer->type == CONSUMER_DST_LOCAL) {
  47                 /* Set application path to the destination path */
  48                 ret = snprintf(tmp_path, sizeof(tmp_path), "%s%s%s",
  49                                 consumer->dst.session_root_path,
  50                                 consumer->chunk_path,
  51                                 consumer->subdir);
  52                 if (ret < 0) {
  53                         PERROR("snprintf kernel channel path");
  54                         goto error;
  55                 } else if (ret >= sizeof(tmp_path)) {
  56                         ERR("Kernel channel path exceeds the maximal allowed length of of %zu bytes (%i bytes required) with path \"%s%s%s\"",
  57                                         sizeof(tmp_path), ret,
  58                                         consumer->dst.session_root_path,
  59                                         consumer->chunk_path,
  60                                         consumer->subdir);
  61                         goto error;
  62                 }
  63                 pathname = lttng_strndup(tmp_path, sizeof(tmp_path));
  64                 if (!pathname) {
  65                         PERROR("lttng_strndup");
  66                         goto error;
  67                 }
  68
  69                 /* Create directory */
  70                 ret = run_as_mkdir_recursive(pathname, S_IRWXU | S_IRWXG, uid, gid);
  71                 if (ret < 0) {
  72                         if (errno != EEXIST) {
  73                                 ERR("Trace directory creation error");
  74                                 goto error;
  75                         }
  76                 }
  77                 DBG3("Kernel local consumer tracefile path: %s", pathname);
  78         } else {
  79                 ret = snprintf(tmp_path, sizeof(tmp_path), "%s%s",
  80                                 consumer->dst.net.base_dir,
  81                                 consumer->subdir);
  82                 if (ret < 0) {
  83                         PERROR("snprintf kernel metadata path");
  84                         goto error;
  85                 } else if (ret >= sizeof(tmp_path)) {
  86                         ERR("Kernel channel path exceeds the maximal allowed length of of %zu bytes (%i bytes required) with path \"%s%s\"",
  87                                         sizeof(tmp_path), ret,
  88                                         consumer->dst.net.base_dir,
  89                                         consumer->subdir);
  90                         goto error;
  91                 }
  92                 pathname = lttng_strndup(tmp_path, sizeof(tmp_path));
  93                 if (!pathname) {
  94                         PERROR("lttng_strndup");
  95                         goto error;
  96                 }
  97                 DBG3("Kernel network consumer subdir path: %s", pathname);
  98         }
  99
 100         return pathname;
 101
 102 error:
 103         free(pathname);
 104         return NULL;
 105 }
 106
 107 /*
 108  * Sending a single channel to the consumer with command ADD_CHANNEL.
 109  */
 110 int kernel_consumer_add_channel(struct consumer_socket *sock,
 111                 struct ltt_kernel_channel *channel,
 112                 struct ltt_kernel_session *ksession,
 113                 unsigned int monitor)
 114 {
 115         int ret;
 116         char *pathname;
 117         struct lttcomm_consumer_msg lkm;
 118         struct consumer_output *consumer;
 119         enum lttng_error_code status;
 120         struct ltt_session *session;
 121         struct lttng_channel_extended *channel_attr_extended;
 122
 123         /* Safety net */
 124         assert(channel);
 125         assert(ksession);
 126         assert(ksession->consumer);
 127
 128         consumer = ksession->consumer;
 129         channel_attr_extended = (struct lttng_channel_extended *)
 130                         channel->channel->attr.extended.ptr;
 131
 132         DBG("Kernel consumer adding channel %s to kernel consumer",
 133                         channel->channel->name);
 134
 135         if (monitor) {
 136                 pathname = create_channel_path(consumer, ksession->uid,
 137                                 ksession->gid);
 138         } else {
 139                 /* Empty path. */
 140                 pathname = strdup("");
 141         }
 142         if (!pathname) {
 143                 ret = -1;
 144                 goto error;
 145         }
 146
 147         /* Prep channel message structure */
 148         consumer_init_add_channel_comm_msg(&lkm,
 149                         channel->key,
 150                         ksession->id,
 151                         pathname,
 152                         ksession->uid,
 153                         ksession->gid,
 154                         consumer->net_seq_index,
 155                         channel->channel->name,
 156                         channel->stream_count,
 157                         channel->channel->attr.output,
 158                         CONSUMER_CHANNEL_TYPE_DATA,
 159                         channel->channel->attr.tracefile_size,
 160                         channel->channel->attr.tracefile_count,
 161                         monitor,
 162                         channel->channel->attr.live_timer_interval,
 163                         channel_attr_extended->monitor_timer_interval);
 164
 165         health_code_update();
 166
 167         ret = consumer_send_channel(sock, &lkm);
 168         if (ret < 0) {
 169                 goto error;
 170         }
 171
 172         health_code_update();
 173         rcu_read_lock();
 174         session = session_find_by_id(ksession->id);
 175         assert(session);
 176
 177         status = notification_thread_command_add_channel(
 178                         notification_thread_handle, session->name,
 179                         ksession->uid, ksession->gid,
 180                         channel->channel->name, channel->key,
 181                         LTTNG_DOMAIN_KERNEL,
 182                         channel->channel->attr.subbuf_size * channel->channel->attr.num_subbuf);
 183         rcu_read_unlock();
 184         if (status != LTTNG_OK) {
 185                 ret = -1;
 186                 goto error;
 187         }
 188
 189         channel->published_to_notification_thread = true;
 190
 191 error:
 192         free(pathname);
 193         return ret;
 194 }
 195
 196 /*
 197  * Sending metadata to the consumer with command ADD_CHANNEL and ADD_STREAM.
 198  *
 199  * The consumer socket lock must be held by the caller.
 200  */
 201 int kernel_consumer_add_metadata(struct consumer_socket *sock,
 202                 struct ltt_kernel_session *session, unsigned int monitor)
 203 {
 204         int ret;
 205         char *pathname;
 206         struct lttcomm_consumer_msg lkm;
 207         struct consumer_output *consumer;
 208
 209         /* Safety net */
 210         assert(session);
 211         assert(session->consumer);
 212         assert(sock);
 213
 214         DBG("Sending metadata %d to kernel consumer", session->metadata_stream_fd);
 215
 216         /* Get consumer output pointer */
 217         consumer = session->consumer;
 218
 219         if (monitor) {
 220                 pathname = create_channel_path(consumer, session->uid, session->gid);
 221         } else {
 222                 /* Empty path. */
 223                 pathname = strdup("");
 224         }
 225         if (!pathname) {
 226                 ret = -1;
 227                 goto error;
 228         }
 229
 230         /* Prep channel message structure */
 231         consumer_init_add_channel_comm_msg(&lkm,
 232                         session->metadata->key,
 233                         session->id,
 234                         pathname,
 235                         session->uid,
 236                         session->gid,
 237                         consumer->net_seq_index,
 238                         DEFAULT_METADATA_NAME,
 239                         1,
 240                         DEFAULT_KERNEL_CHANNEL_OUTPUT,
 241                         CONSUMER_CHANNEL_TYPE_METADATA,
 242                         0, 0,
 243                         monitor, 0, 0);
 244
 245         health_code_update();
 246
 247         ret = consumer_send_channel(sock, &lkm);
 248         if (ret < 0) {
 249                 goto error;
 250         }
 251
 252         health_code_update();
 253
 254         /* Prep stream message structure */
 255         consumer_init_stream_comm_msg(&lkm,
 256                         LTTNG_CONSUMER_ADD_STREAM,
 257                         session->metadata->key,
 258                         session->metadata_stream_fd,
 259                         0); /* CPU: 0 for metadata. */
 260
 261         health_code_update();
 262
 263         /* Send stream and file descriptor */
 264         ret = consumer_send_stream(sock, consumer, &lkm,
 265                         &session->metadata_stream_fd, 1);
 266         if (ret < 0) {
 267                 goto error;
 268         }
 269
 270         health_code_update();
 271
 272 error:
 273         free(pathname);
 274         return ret;
 275 }
 276
 277 /*
 278  * Sending a single stream to the consumer with command ADD_STREAM.
 279  */
 280 static
 281 int kernel_consumer_add_stream(struct consumer_socket *sock,
 282                 struct ltt_kernel_channel *channel, struct ltt_kernel_stream *stream,
 283                 struct ltt_kernel_session *session, unsigned int monitor)
 284 {
 285         int ret;
 286         struct lttcomm_consumer_msg lkm;
 287         struct consumer_output *consumer;
 288
 289         assert(channel);
 290         assert(stream);
 291         assert(session);
 292         assert(session->consumer);
 293         assert(sock);
 294
 295         DBG("Sending stream %d of channel %s to kernel consumer",
 296                         stream->fd, channel->channel->name);
 297
 298         /* Get consumer output pointer */
 299         consumer = session->consumer;
 300
 301         /* Prep stream consumer message */
 302         consumer_init_stream_comm_msg(&lkm,
 303                         LTTNG_CONSUMER_ADD_STREAM,
 304                         channel->key,
 305                         stream->fd,
 306                         stream->cpu);
 307
 308         health_code_update();
 309
 310         /* Send stream and file descriptor */
 311         ret = consumer_send_stream(sock, consumer, &lkm, &stream->fd, 1);
 312         if (ret < 0) {
 313                 goto error;
 314         }
 315
 316         health_code_update();
 317
 318 error:
 319         return ret;
 320 }
 321
 322 /*
 323  * Sending the notification that all streams were sent with STREAMS_SENT.
 324  */
 325 int kernel_consumer_streams_sent(struct consumer_socket *sock,
 326                 struct ltt_kernel_session *session, uint64_t channel_key)
 327 {
 328         int ret;
 329         struct lttcomm_consumer_msg lkm;
 330         struct consumer_output *consumer;
 331
 332         assert(sock);
 333         assert(session);
 334
 335         DBG("Sending streams_sent");
 336         /* Get consumer output pointer */
 337         consumer = session->consumer;
 338
 339         /* Prep stream consumer message */
 340         consumer_init_streams_sent_comm_msg(&lkm,
 341                         LTTNG_CONSUMER_STREAMS_SENT,
 342                         channel_key, consumer->net_seq_index);
 343
 344         health_code_update();
 345
 346         /* Send stream and file descriptor */
 347         ret = consumer_send_msg(sock, &lkm);
 348         if (ret < 0) {
 349                 goto error;
 350         }
 351
 352 error:
 353         return ret;
 354 }
 355
 356 /*
 357  * Send all stream fds of kernel channel to the consumer.
 358  *
 359  * The consumer socket lock must be held by the caller.
 360  */
 361 int kernel_consumer_send_channel_streams(struct consumer_socket *sock,
 362                 struct ltt_kernel_channel *channel, struct ltt_kernel_session *session,
 363                 unsigned int monitor)
 364 {
 365         int ret = LTTNG_OK;
 366         struct ltt_kernel_stream *stream;
 367
 368         /* Safety net */
 369         assert(channel);
 370         assert(session);
 371         assert(session->consumer);
 372         assert(sock);
 373
 374         /* Bail out if consumer is disabled */
 375         if (!session->consumer->enabled) {
 376                 ret = LTTNG_OK;
 377                 goto error;
 378         }
 379
 380         DBG("Sending streams of channel %s to kernel consumer",
 381                         channel->channel->name);
 382
 383         if (!channel->sent_to_consumer) {
 384                 ret = kernel_consumer_add_channel(sock, channel, session, monitor);
 385                 if (ret < 0) {
 386                         goto error;
 387                 }
 388                 channel->sent_to_consumer = true;
 389         }
 390
 391         /* Send streams */
 392         cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
 393                 if (!stream->fd || stream->sent_to_consumer) {
 394                         continue;
 395                 }
 396
 397                 /* Add stream on the kernel consumer side. */
 398                 ret = kernel_consumer_add_stream(sock, channel, stream, session,
 399                                 monitor);
 400                 if (ret < 0) {
 401                         goto error;
 402                 }
 403                 stream->sent_to_consumer = true;
 404         }
 405
 406 error:
 407         return ret;
 408 }
 409
 410 /*
 411  * Send all stream fds of the kernel session to the consumer.
 412  *
 413  * The consumer socket lock must be held by the caller.
 414  */
 415 int kernel_consumer_send_session(struct consumer_socket *sock,
 416                 struct ltt_kernel_session *session)
 417 {
 418         int ret, monitor = 0;
 419         struct ltt_kernel_channel *chan;
 420
 421         /* Safety net */
 422         assert(session);
 423         assert(session->consumer);
 424         assert(sock);
 425
 426         /* Bail out if consumer is disabled */
 427         if (!session->consumer->enabled) {
 428                 ret = LTTNG_OK;
 429                 goto error;
 430         }
 431
 432         /* Don't monitor the streams on the consumer if in flight recorder. */
 433         if (session->output_traces) {
 434                 monitor = 1;
 435         }
 436
 437         DBG("Sending session stream to kernel consumer");
 438
 439         if (session->metadata_stream_fd >= 0 && session->metadata) {
 440                 ret = kernel_consumer_add_metadata(sock, session, monitor);
 441                 if (ret < 0) {
 442                         goto error;
 443                 }
 444         }
 445
 446         /* Send channel and streams of it */
 447         cds_list_for_each_entry(chan, &session->channel_list.head, list) {
 448                 ret = kernel_consumer_send_channel_streams(sock, chan, session,
 449                                 monitor);
 450                 if (ret < 0) {
 451                         goto error;
 452                 }
 453                 if (monitor) {
 454                         /*
 455                          * Inform the relay that all the streams for the
 456                          * channel were sent.
 457                          */
 458                         ret = kernel_consumer_streams_sent(sock, session, chan->key);
 459                         if (ret < 0) {
 460                                 goto error;
 461                         }
 462                 }
 463         }
 464
 465         DBG("Kernel consumer FDs of metadata and channel streams sent");
 466
 467         session->consumer_fds_sent = 1;
 468         return 0;
 469
 470 error:
 471         return ret;
 472 }
 473
 474 int kernel_consumer_destroy_channel(struct consumer_socket *socket,
 475                 struct ltt_kernel_channel *channel)
 476 {
 477         int ret;
 478         struct lttcomm_consumer_msg msg;
 479
 480         assert(channel);
 481         assert(socket);
 482
 483         DBG("Sending kernel consumer destroy channel key %" PRIu64, channel->key);
 484
 485         memset(&msg, 0, sizeof(msg));
 486         msg.cmd_type = LTTNG_CONSUMER_DESTROY_CHANNEL;
 487         msg.u.destroy_channel.key = channel->key;
 488
 489         pthread_mutex_lock(socket->lock);
 490         health_code_update();
 491
 492         ret = consumer_send_msg(socket, &msg);
 493         if (ret < 0) {
 494                 goto error;
 495         }
 496
 497 error:
 498         health_code_update();
 499         pthread_mutex_unlock(socket->lock);
 500         return ret;
 501 }
 502
 503 int kernel_consumer_destroy_metadata(struct consumer_socket *socket,
 504                 struct ltt_kernel_metadata *metadata)
 505 {
 506         int ret;
 507         struct lttcomm_consumer_msg msg;
 508
 509         assert(metadata);
 510         assert(socket);
 511
 512         DBG("Sending kernel consumer destroy channel key %" PRIu64, metadata->key);
 513
 514         memset(&msg, 0, sizeof(msg));
 515         msg.cmd_type = LTTNG_CONSUMER_DESTROY_CHANNEL;
 516         msg.u.destroy_channel.key = metadata->key;
 517
 518         pthread_mutex_lock(socket->lock);
 519         health_code_update();
 520
 521         ret = consumer_send_msg(socket, &msg);
 522         if (ret < 0) {
 523                 goto error;
 524         }
 525
 526 error:
 527         health_code_update();
 528         pthread_mutex_unlock(socket->lock);
 529         return ret;
 530 }