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

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _LGPL_SOURCE
  19 #include <errno.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <inttypes.h>
  25
  26 #include <common/common.h>
  27 #include <common/consumer/consumer.h>
  28 #include <common/defaults.h>
  29
  30 #include "consumer.h"
  31 #include "health-sessiond.h"
  32 #include "ust-consumer.h"
  33 #include "buffer-registry.h"
  34 #include "session.h"
  35 #include "lttng-sessiond.h"
  36
  37 /*
  38  * Return allocated full pathname of the session using the consumer trace path
  39  * and subdir if available. On a successful allocation, the directory of the
  40  * trace is created with the session credentials.
  41  *
  42  * The caller can safely free(3) the returned value. On error, NULL is
  43  * returned.
  44  */
  45 static char *setup_trace_path(struct consumer_output *consumer,
  46                 struct ust_app_session *ua_sess)
  47 {
  48         int ret;
  49         char *pathname;
  50
  51         assert(consumer);
  52         assert(ua_sess);
  53
  54         health_code_update();
  55
  56         /*
  57          * Allocate the string ourself to make sure we never exceed
  58          * LTTNG_PATH_MAX.
  59          */
  60         pathname = zmalloc(LTTNG_PATH_MAX);
  61         if (!pathname) {
  62                 goto error;
  63         }
  64
  65         /* Get correct path name destination */
  66         if (consumer->type == CONSUMER_DST_LOCAL) {
  67                 /* Set application path to the destination path */
  68                 ret = snprintf(pathname, LTTNG_PATH_MAX, "%s%s%s%s",
  69                                 consumer->dst.session_root_path,
  70                                 consumer->chunk_path,
  71                                 consumer->subdir, ua_sess->path);
  72                 if (ret < 0) {
  73                         PERROR("snprintf channel path");
  74                         goto error;
  75                 }
  76
  77                 /* Create directory. Ignore if exist. */
  78                 ret = run_as_mkdir_recursive(pathname, S_IRWXU | S_IRWXG,
  79                                 ua_sess->euid, ua_sess->egid);
  80                 if (ret < 0) {
  81                         if (errno != EEXIST) {
  82                                 ERR("Trace directory creation error");
  83                                 goto error;
  84                         }
  85                 }
  86         } else {
  87                 ret = snprintf(pathname, LTTNG_PATH_MAX, "%s%s%s%s",
  88                                 consumer->dst.net.base_dir,
  89                                 consumer->chunk_path,
  90                                 consumer->subdir,
  91                                 ua_sess->path);
  92                 if (ret < 0) {
  93                         PERROR("snprintf channel path");
  94                         goto error;
  95                 }
  96         }
  97
  98         return pathname;
  99
 100 error:
 101         free(pathname);
 102         return NULL;
 103 }
 104
 105 /*
 106  * Send a single channel to the consumer using command ASK_CHANNEL_CREATION.
 107  *
 108  * Consumer socket lock MUST be acquired before calling this.
 109  */
 110 static int ask_channel_creation(struct ust_app_session *ua_sess,
 111                 struct ust_app_channel *ua_chan,
 112                 struct consumer_output *consumer,
 113                 struct consumer_socket *socket,
 114                 struct ust_registry_session *registry,
 115                 uint64_t trace_archive_id)
 116 {
 117         int ret, output;
 118         uint32_t chan_id;
 119         uint64_t key, chan_reg_key;
 120         char *pathname = NULL;
 121         struct lttcomm_consumer_msg msg;
 122         struct ust_registry_channel *chan_reg;
 123         char shm_path[PATH_MAX] = "";
 124         char root_shm_path[PATH_MAX] = "";
 125
 126         assert(ua_sess);
 127         assert(ua_chan);
 128         assert(socket);
 129         assert(consumer);
 130         assert(registry);
 131
 132         DBG2("Asking UST consumer for channel");
 133
 134         /* Get and create full trace path of session. */
 135         if (ua_sess->output_traces) {
 136                 pathname = setup_trace_path(consumer, ua_sess);
 137                 if (!pathname) {
 138                         ret = -1;
 139                         goto error;
 140                 }
 141         }
 142
 143         /* Depending on the buffer type, a different channel key is used. */
 144         if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
 145                 chan_reg_key = ua_chan->tracing_channel_id;
 146         } else {
 147                 chan_reg_key = ua_chan->key;
 148         }
 149
 150         if (ua_chan->attr.type == LTTNG_UST_CHAN_METADATA) {
 151                 chan_id = -1U;
 152                 /*
 153                  * Metadata channels shm_path (buffers) are handled within
 154                  * session daemon. Consumer daemon should not try to create
 155                  * those buffer files.
 156                  */
 157         } else {
 158                 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
 159                 assert(chan_reg);
 160                 chan_id = chan_reg->chan_id;
 161                 if (ua_sess->shm_path[0]) {
 162                         strncpy(shm_path, ua_sess->shm_path, sizeof(shm_path));
 163                         shm_path[sizeof(shm_path) - 1] = '\0';
 164                         strncat(shm_path, "/",
 165                                 sizeof(shm_path) - strlen(shm_path) - 1);
 166                         strncat(shm_path, ua_chan->name,
 167                                         sizeof(shm_path) - strlen(shm_path) - 1);
 168                                 strncat(shm_path, "_",
 169                                         sizeof(shm_path) - strlen(shm_path) - 1);
 170                 }
 171                 strncpy(root_shm_path, ua_sess->root_shm_path, sizeof(root_shm_path));
 172                 root_shm_path[sizeof(root_shm_path) - 1] = '\0';
 173         }
 174
 175         switch (ua_chan->attr.output) {
 176         case LTTNG_UST_MMAP:
 177         default:
 178                 output = LTTNG_EVENT_MMAP;
 179                 break;
 180         }
 181
 182         consumer_init_ask_channel_comm_msg(&msg,
 183                         ua_chan->attr.subbuf_size,
 184                         ua_chan->attr.num_subbuf,
 185                         ua_chan->attr.overwrite,
 186                         ua_chan->attr.switch_timer_interval,
 187                         ua_chan->attr.read_timer_interval,
 188                         ua_sess->live_timer_interval,
 189                         ua_chan->monitor_timer_interval,
 190                         output,
 191                         (int) ua_chan->attr.type,
 192                         ua_sess->tracing_id,
 193                         pathname,
 194                         ua_chan->name,
 195                         ua_sess->euid,
 196                         ua_sess->egid,
 197                         consumer->net_seq_index,
 198                         ua_chan->key,
 199                         registry->uuid,
 200                         chan_id,
 201                         ua_chan->tracefile_size,
 202                         ua_chan->tracefile_count,
 203                         ua_sess->id,
 204                         ua_sess->output_traces,
 205                         ua_sess->uid,
 206                         ua_chan->attr.blocking_timeout,
 207                         root_shm_path, shm_path,
 208                         trace_archive_id);
 209
 210         health_code_update();
 211
 212         ret = consumer_socket_send(socket, &msg, sizeof(msg));
 213         if (ret < 0) {
 214                 goto error;
 215         }
 216
 217         ret = consumer_recv_status_channel(socket, &key,
 218                         &ua_chan->expected_stream_count);
 219         if (ret < 0) {
 220                 goto error;
 221         }
 222         /* Communication protocol error. */
 223         assert(key == ua_chan->key);
 224         /* We need at least one where 1 stream for 1 cpu. */
 225         if (ua_sess->output_traces) {
 226                 assert(ua_chan->expected_stream_count > 0);
 227         }
 228
 229         DBG2("UST ask channel %" PRIu64 " successfully done with %u stream(s)", key,
 230                         ua_chan->expected_stream_count);
 231
 232 error:
 233         free(pathname);
 234         health_code_update();
 235         return ret;
 236 }
 237
 238 /*
 239  * Ask consumer to create a channel for a given session.
 240  *
 241  * Session list and rcu read side locks must be held by the caller.
 242  *
 243  * Returns 0 on success else a negative value.
 244  */
 245 int ust_consumer_ask_channel(struct ust_app_session *ua_sess,
 246                 struct ust_app_channel *ua_chan,
 247                 struct consumer_output *consumer,
 248                 struct consumer_socket *socket,
 249                 struct ust_registry_session *registry,
 250                 uint64_t trace_archive_id)
 251 {
 252         int ret;
 253
 254         assert(ua_sess);
 255         assert(ua_chan);
 256         assert(consumer);
 257         assert(socket);
 258         assert(registry);
 259
 260         if (!consumer->enabled) {
 261                 ret = -LTTNG_ERR_NO_CONSUMER;
 262                 DBG3("Consumer is disabled");
 263                 goto error;
 264         }
 265
 266         pthread_mutex_lock(socket->lock);
 267         ret = ask_channel_creation(ua_sess, ua_chan, consumer, socket, registry,
 268                         trace_archive_id);
 269         pthread_mutex_unlock(socket->lock);
 270         if (ret < 0) {
 271                 ERR("ask_channel_creation consumer command failed");
 272                 goto error;
 273         }
 274
 275 error:
 276         return ret;
 277 }
 278
 279 /*
 280  * Send a get channel command to consumer using the given channel key.  The
 281  * channel object is populated and the stream list.
 282  *
 283  * Return 0 on success else a negative value.
 284  */
 285 int ust_consumer_get_channel(struct consumer_socket *socket,
 286                 struct ust_app_channel *ua_chan)
 287 {
 288         int ret;
 289         struct lttcomm_consumer_msg msg;
 290
 291         assert(ua_chan);
 292         assert(socket);
 293
 294         memset(&msg, 0, sizeof(msg));
 295         msg.cmd_type = LTTNG_CONSUMER_GET_CHANNEL;
 296         msg.u.get_channel.key = ua_chan->key;
 297
 298         pthread_mutex_lock(socket->lock);
 299         health_code_update();
 300
 301         /* Send command and wait for OK reply. */
 302         ret = consumer_send_msg(socket, &msg);
 303         if (ret < 0) {
 304                 goto error;
 305         }
 306
 307         /* First, get the channel from consumer. */
 308         ret = ustctl_recv_channel_from_consumer(*socket->fd_ptr, &ua_chan->obj);
 309         if (ret < 0) {
 310                 if (ret != -EPIPE) {
 311                         ERR("Error recv channel from consumer %d with ret %d",
 312                                         *socket->fd_ptr, ret);
 313                 } else {
 314                         DBG3("UST app recv channel from consumer. Consumer is dead.");
 315                 }
 316                 goto error;
 317         }
 318
 319         /* Next, get all streams. */
 320         while (1) {
 321                 struct ust_app_stream *stream;
 322
 323                 /* Create UST stream */
 324                 stream = ust_app_alloc_stream();
 325                 if (stream == NULL) {
 326                         ret = -ENOMEM;
 327                         goto error;
 328                 }
 329
 330                 /* Stream object is populated by this call if successful. */
 331                 ret = ustctl_recv_stream_from_consumer(*socket->fd_ptr, &stream->obj);
 332                 if (ret < 0) {
 333                         free(stream);
 334                         if (ret == -LTTNG_UST_ERR_NOENT) {
 335                                 DBG3("UST app consumer has no more stream available");
 336                                 break;
 337                         }
 338                         if (ret != -EPIPE) {
 339                                 ERR("Recv stream from consumer %d with ret %d",
 340                                                 *socket->fd_ptr, ret);
 341                         } else {
 342                                 DBG3("UST app recv stream from consumer. Consumer is dead.");
 343                         }
 344                         goto error;
 345                 }
 346
 347                 /* Order is important this is why a list is used. */
 348                 cds_list_add_tail(&stream->list, &ua_chan->streams.head);
 349                 ua_chan->streams.count++;
 350
 351                 DBG2("UST app stream %d received successfully", ua_chan->streams.count);
 352         }
 353
 354         /* This MUST match or else we have a synchronization problem. */
 355         assert(ua_chan->expected_stream_count == ua_chan->streams.count);
 356
 357         /* Wait for confirmation that we can proceed with the streams. */
 358         ret = consumer_recv_status_reply(socket);
 359         if (ret < 0) {
 360                 goto error;
 361         }
 362
 363 error:
 364         health_code_update();
 365         pthread_mutex_unlock(socket->lock);
 366         return ret;
 367 }
 368
 369 /*
 370  * Send a destroy channel command to consumer using the given channel key.
 371  *
 372  * Note that this command MUST be used prior to a successful
 373  * LTTNG_CONSUMER_GET_CHANNEL because once this command is done successfully,
 374  * the streams are dispatched to the consumer threads and MUST be teardown
 375  * through the hang up process.
 376  *
 377  * Return 0 on success else a negative value.
 378  */
 379 int ust_consumer_destroy_channel(struct consumer_socket *socket,
 380                 struct ust_app_channel *ua_chan)
 381 {
 382         int ret;
 383         struct lttcomm_consumer_msg msg;
 384
 385         assert(ua_chan);
 386         assert(socket);
 387
 388         memset(&msg, 0, sizeof(msg));
 389         msg.cmd_type = LTTNG_CONSUMER_DESTROY_CHANNEL;
 390         msg.u.destroy_channel.key = ua_chan->key;
 391
 392         pthread_mutex_lock(socket->lock);
 393         health_code_update();
 394
 395         ret = consumer_send_msg(socket, &msg);
 396         if (ret < 0) {
 397                 goto error;
 398         }
 399
 400 error:
 401         health_code_update();
 402         pthread_mutex_unlock(socket->lock);
 403         return ret;
 404 }
 405
 406 /*
 407  * Send a given stream to UST tracer.
 408  *
 409  * On success return 0 else a negative value.
 410  */
 411 int ust_consumer_send_stream_to_ust(struct ust_app *app,
 412                 struct ust_app_channel *channel, struct ust_app_stream *stream)
 413 {
 414         int ret;
 415
 416         assert(app);
 417         assert(stream);
 418         assert(channel);
 419
 420         DBG2("UST consumer send stream to app %d", app->sock);
 421
 422         /* Relay stream to application. */
 423         pthread_mutex_lock(&app->sock_lock);
 424         ret = ustctl_send_stream_to_ust(app->sock, channel->obj, stream->obj);
 425         pthread_mutex_unlock(&app->sock_lock);
 426         if (ret < 0) {
 427                 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
 428                         ERR("ustctl send stream handle %d to app pid: %d with ret %d",
 429                                         stream->obj->handle, app->pid, ret);
 430                 } else {
 431                         DBG3("UST app send stream to ust failed. Application is dead.");
 432                 }
 433                 goto error;
 434         }
 435         channel->handle = channel->obj->handle;
 436
 437 error:
 438         return ret;
 439 }
 440
 441 /*
 442  * Send channel previously received from the consumer to the UST tracer.
 443  *
 444  * On success return 0 else a negative value.
 445  */
 446 int ust_consumer_send_channel_to_ust(struct ust_app *app,
 447                 struct ust_app_session *ua_sess, struct ust_app_channel *channel)
 448 {
 449         int ret;
 450
 451         assert(app);
 452         assert(ua_sess);
 453         assert(channel);
 454         assert(channel->obj);
 455
 456         DBG2("UST app send channel to sock %d pid %d (name: %s, key: %" PRIu64 ")",
 457                         app->sock, app->pid, channel->name, channel->tracing_channel_id);
 458
 459         /* Send stream to application. */
 460         pthread_mutex_lock(&app->sock_lock);
 461         ret = ustctl_send_channel_to_ust(app->sock, ua_sess->handle, channel->obj);
 462         pthread_mutex_unlock(&app->sock_lock);
 463         if (ret < 0) {
 464                 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
 465                         ERR("Error ustctl send channel %s to app pid: %d with ret %d",
 466                                         channel->name, app->pid, ret);
 467                 } else {
 468                         DBG3("UST app send channel to ust failed. Application is dead.");
 469                 }
 470                 goto error;
 471         }
 472
 473 error:
 474         return ret;
 475 }
 476
 477 /*
 478  * Handle the metadata requests from the UST consumer
 479  *
 480  * Return 0 on success else a negative value.
 481  */
 482 int ust_consumer_metadata_request(struct consumer_socket *socket)
 483 {
 484         int ret;
 485         ssize_t ret_push;
 486         struct lttcomm_metadata_request_msg request;
 487         struct buffer_reg_uid *reg_uid;
 488         struct ust_registry_session *ust_reg;
 489         struct lttcomm_consumer_msg msg;
 490
 491         assert(socket);
 492
 493         rcu_read_lock();
 494         health_code_update();
 495
 496         /* Wait for a metadata request */
 497         pthread_mutex_lock(socket->lock);
 498         ret = consumer_socket_recv(socket, &request, sizeof(request));
 499         pthread_mutex_unlock(socket->lock);
 500         if (ret < 0) {
 501                 goto end;
 502         }
 503
 504         DBG("Metadata request received for session %" PRIu64 ", key %" PRIu64,
 505                         request.session_id, request.key);
 506
 507         reg_uid = buffer_reg_uid_find(request.session_id,
 508                         request.bits_per_long, request.uid);
 509         if (reg_uid) {
 510                 ust_reg = reg_uid->registry->reg.ust;
 511         } else {
 512                 struct buffer_reg_pid *reg_pid =
 513                         buffer_reg_pid_find(request.session_id_per_pid);
 514                 if (!reg_pid) {
 515                         DBG("PID registry not found for session id %" PRIu64,
 516                                         request.session_id_per_pid);
 517
 518                         memset(&msg, 0, sizeof(msg));
 519                         msg.cmd_type = LTTNG_ERR_UND;
 520                         pthread_mutex_lock(socket->lock);
 521                         (void) consumer_send_msg(socket, &msg);
 522                         pthread_mutex_unlock(socket->lock);
 523                         /*
 524                          * This is possible since the session might have been destroyed
 525                          * during a consumer metadata request. So here, return gracefully
 526                          * because the destroy session will push the remaining metadata to
 527                          * the consumer.
 528                          */
 529                         ret = 0;
 530                         goto end;
 531                 }
 532                 ust_reg = reg_pid->registry->reg.ust;
 533         }
 534         assert(ust_reg);
 535
 536         pthread_mutex_lock(&ust_reg->lock);
 537         ret_push = ust_app_push_metadata(ust_reg, socket, 1);
 538         pthread_mutex_unlock(&ust_reg->lock);
 539         if (ret_push == -EPIPE) {
 540                 DBG("Application or relay closed while pushing metadata");
 541         } else if (ret_push < 0) {
 542                 ERR("Pushing metadata");
 543                 ret = -1;
 544                 goto end;
 545         } else {
 546                 DBG("UST Consumer metadata pushed successfully");
 547         }
 548         ret = 0;
 549
 550 end:
 551         rcu_read_unlock();
 552         return ret;
 553 }