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  * Send a single channel to the consumer using command ASK_CHANNEL_CREATION.
  39  *
  40  * Consumer socket lock MUST be acquired before calling this.
  41  */
  42 static int ask_channel_creation(struct ust_app_session *ua_sess,
  43                 struct ust_app_channel *ua_chan,
  44                 struct consumer_output *consumer,
  45                 struct consumer_socket *socket,
  46                 struct ust_registry_session *registry,
  47                 struct lttng_trace_chunk *trace_chunk)
  48 {
  49         int ret, output;
  50         uint32_t chan_id;
  51         uint64_t key, chan_reg_key;
  52         char *pathname = NULL;
  53         struct lttcomm_consumer_msg msg;
  54         struct ust_registry_channel *chan_reg;
  55         char shm_path[PATH_MAX] = "";
  56         char root_shm_path[PATH_MAX] = "";
  57         bool is_local_trace;
  58
  59         assert(ua_sess);
  60         assert(ua_chan);
  61         assert(socket);
  62         assert(consumer);
  63         assert(registry);
  64
  65         DBG2("Asking UST consumer for channel");
  66
  67         is_local_trace = consumer->net_seq_index == -1ULL;
  68         /* Format the channel's path (relative to the current trace chunk). */
  69         pathname = setup_channel_trace_path(consumer, ua_sess->path);
  70         if (!pathname) {
  71                 ret = -1;
  72                 goto error;
  73         }
  74
  75         if (is_local_trace && trace_chunk) {
  76                 enum lttng_trace_chunk_status chunk_status;
  77                 char *pathname_index;
  78
  79                 ret = asprintf(&pathname_index, "%s/" DEFAULT_INDEX_DIR,
  80                                 pathname);
  81                 if (ret < 0) {
  82                         ERR("Failed to format channel index directory");
  83                         ret = -1;
  84                         goto error;
  85                 }
  86
  87                 /*
  88                  * Create the index subdirectory which will take care
  89                  * of implicitly creating the channel's path.
  90                  */
  91                 chunk_status = lttng_trace_chunk_create_subdirectory(
  92                                 trace_chunk, pathname_index);
  93                 free(pathname_index);
  94                 if (chunk_status != LTTNG_TRACE_CHUNK_STATUS_OK) {
  95                         ret = -1;
  96                         goto error;
  97                 }
  98         }
  99
 100         /* Depending on the buffer type, a different channel key is used. */
 101         if (ua_sess->buffer_type == LTTNG_BUFFER_PER_UID) {
 102                 chan_reg_key = ua_chan->tracing_channel_id;
 103         } else {
 104                 chan_reg_key = ua_chan->key;
 105         }
 106
 107         if (ua_chan->attr.type == LTTNG_UST_CHAN_METADATA) {
 108                 chan_id = -1U;
 109                 /*
 110                  * Metadata channels shm_path (buffers) are handled within
 111                  * session daemon. Consumer daemon should not try to create
 112                  * those buffer files.
 113                  */
 114         } else {
 115                 chan_reg = ust_registry_channel_find(registry, chan_reg_key);
 116                 assert(chan_reg);
 117                 chan_id = chan_reg->chan_id;
 118                 if (ua_sess->shm_path[0]) {
 119                         strncpy(shm_path, ua_sess->shm_path, sizeof(shm_path));
 120                         shm_path[sizeof(shm_path) - 1] = '\0';
 121                         strncat(shm_path, "/",
 122                                 sizeof(shm_path) - strlen(shm_path) - 1);
 123                         strncat(shm_path, ua_chan->name,
 124                                         sizeof(shm_path) - strlen(shm_path) - 1);
 125                                 strncat(shm_path, "_",
 126                                         sizeof(shm_path) - strlen(shm_path) - 1);
 127                 }
 128                 strncpy(root_shm_path, ua_sess->root_shm_path, sizeof(root_shm_path));
 129                 root_shm_path[sizeof(root_shm_path) - 1] = '\0';
 130         }
 131
 132         switch (ua_chan->attr.output) {
 133         case LTTNG_UST_MMAP:
 134         default:
 135                 output = LTTNG_EVENT_MMAP;
 136                 break;
 137         }
 138
 139         consumer_init_ask_channel_comm_msg(&msg,
 140                         ua_chan->attr.subbuf_size,
 141                         ua_chan->attr.num_subbuf,
 142                         ua_chan->attr.overwrite,
 143                         ua_chan->attr.switch_timer_interval,
 144                         ua_chan->attr.read_timer_interval,
 145                         ua_sess->live_timer_interval,
 146                         ua_chan->monitor_timer_interval,
 147                         output,
 148                         (int) ua_chan->attr.type,
 149                         ua_sess->tracing_id,
 150                         pathname,
 151                         ua_chan->name,
 152                         consumer->net_seq_index,
 153                         ua_chan->key,
 154                         registry->uuid,
 155                         chan_id,
 156                         ua_chan->tracefile_size,
 157                         ua_chan->tracefile_count,
 158                         ua_sess->id,
 159                         ua_sess->output_traces,
 160                         ua_sess->real_credentials.uid,
 161                         ua_chan->attr.blocking_timeout,
 162                         root_shm_path, shm_path,
 163                         trace_chunk,
 164                         &ua_sess->effective_credentials);
 165
 166         health_code_update();
 167
 168         ret = consumer_socket_send(socket, &msg, sizeof(msg));
 169         if (ret < 0) {
 170                 goto error;
 171         }
 172
 173         ret = consumer_recv_status_channel(socket, &key,
 174                         &ua_chan->expected_stream_count);
 175         if (ret < 0) {
 176                 goto error;
 177         }
 178         /* Communication protocol error. */
 179         assert(key == ua_chan->key);
 180         /* We need at least one where 1 stream for 1 cpu. */
 181         if (ua_sess->output_traces) {
 182                 assert(ua_chan->expected_stream_count > 0);
 183         }
 184
 185         DBG2("UST ask channel %" PRIu64 " successfully done with %u stream(s)", key,
 186                         ua_chan->expected_stream_count);
 187
 188 error:
 189         free(pathname);
 190         health_code_update();
 191         return ret;
 192 }
 193
 194 /*
 195  * Ask consumer to create a channel for a given session.
 196  *
 197  * Session list and rcu read side locks must be held by the caller.
 198  *
 199  * Returns 0 on success else a negative value.
 200  */
 201 int ust_consumer_ask_channel(struct ust_app_session *ua_sess,
 202                 struct ust_app_channel *ua_chan,
 203                 struct consumer_output *consumer,
 204                 struct consumer_socket *socket,
 205                 struct ust_registry_session *registry,
 206                 struct lttng_trace_chunk * trace_chunk)
 207 {
 208         int ret;
 209
 210         assert(ua_sess);
 211         assert(ua_chan);
 212         assert(consumer);
 213         assert(socket);
 214         assert(registry);
 215
 216         if (!consumer->enabled) {
 217                 ret = -LTTNG_ERR_NO_CONSUMER;
 218                 DBG3("Consumer is disabled");
 219                 goto error;
 220         }
 221
 222         pthread_mutex_lock(socket->lock);
 223         ret = ask_channel_creation(ua_sess, ua_chan, consumer, socket, registry,
 224                         trace_chunk);
 225         pthread_mutex_unlock(socket->lock);
 226         if (ret < 0) {
 227                 ERR("ask_channel_creation consumer command failed");
 228                 goto error;
 229         }
 230
 231 error:
 232         return ret;
 233 }
 234
 235 /*
 236  * Send a get channel command to consumer using the given channel key.  The
 237  * channel object is populated and the stream list.
 238  *
 239  * Return 0 on success else a negative value.
 240  */
 241 int ust_consumer_get_channel(struct consumer_socket *socket,
 242                 struct ust_app_channel *ua_chan)
 243 {
 244         int ret;
 245         struct lttcomm_consumer_msg msg;
 246
 247         assert(ua_chan);
 248         assert(socket);
 249
 250         memset(&msg, 0, sizeof(msg));
 251         msg.cmd_type = LTTNG_CONSUMER_GET_CHANNEL;
 252         msg.u.get_channel.key = ua_chan->key;
 253
 254         pthread_mutex_lock(socket->lock);
 255         health_code_update();
 256
 257         /* Send command and wait for OK reply. */
 258         ret = consumer_send_msg(socket, &msg);
 259         if (ret < 0) {
 260                 goto error;
 261         }
 262
 263         /* First, get the channel from consumer. */
 264         ret = ustctl_recv_channel_from_consumer(*socket->fd_ptr, &ua_chan->obj);
 265         if (ret < 0) {
 266                 if (ret != -EPIPE) {
 267                         ERR("Error recv channel from consumer %d with ret %d",
 268                                         *socket->fd_ptr, ret);
 269                 } else {
 270                         DBG3("UST app recv channel from consumer. Consumer is dead.");
 271                 }
 272                 goto error;
 273         }
 274
 275         /* Next, get all streams. */
 276         while (1) {
 277                 struct ust_app_stream *stream;
 278
 279                 /* Create UST stream */
 280                 stream = ust_app_alloc_stream();
 281                 if (stream == NULL) {
 282                         ret = -ENOMEM;
 283                         goto error;
 284                 }
 285
 286                 /* Stream object is populated by this call if successful. */
 287                 ret = ustctl_recv_stream_from_consumer(*socket->fd_ptr, &stream->obj);
 288                 if (ret < 0) {
 289                         free(stream);
 290                         if (ret == -LTTNG_UST_ERR_NOENT) {
 291                                 DBG3("UST app consumer has no more stream available");
 292                                 break;
 293                         }
 294                         if (ret != -EPIPE) {
 295                                 ERR("Recv stream from consumer %d with ret %d",
 296                                                 *socket->fd_ptr, ret);
 297                         } else {
 298                                 DBG3("UST app recv stream from consumer. Consumer is dead.");
 299                         }
 300                         goto error;
 301                 }
 302
 303                 /* Order is important this is why a list is used. */
 304                 cds_list_add_tail(&stream->list, &ua_chan->streams.head);
 305                 ua_chan->streams.count++;
 306
 307                 DBG2("UST app stream %d received successfully", ua_chan->streams.count);
 308         }
 309
 310         /* This MUST match or else we have a synchronization problem. */
 311         assert(ua_chan->expected_stream_count == ua_chan->streams.count);
 312
 313         /* Wait for confirmation that we can proceed with the streams. */
 314         ret = consumer_recv_status_reply(socket);
 315         if (ret < 0) {
 316                 goto error;
 317         }
 318
 319 error:
 320         health_code_update();
 321         pthread_mutex_unlock(socket->lock);
 322         return ret;
 323 }
 324
 325 /*
 326  * Send a destroy channel command to consumer using the given channel key.
 327  *
 328  * Note that this command MUST be used prior to a successful
 329  * LTTNG_CONSUMER_GET_CHANNEL because once this command is done successfully,
 330  * the streams are dispatched to the consumer threads and MUST be teardown
 331  * through the hang up process.
 332  *
 333  * Return 0 on success else a negative value.
 334  */
 335 int ust_consumer_destroy_channel(struct consumer_socket *socket,
 336                 struct ust_app_channel *ua_chan)
 337 {
 338         int ret;
 339         struct lttcomm_consumer_msg msg;
 340
 341         assert(ua_chan);
 342         assert(socket);
 343
 344         memset(&msg, 0, sizeof(msg));
 345         msg.cmd_type = LTTNG_CONSUMER_DESTROY_CHANNEL;
 346         msg.u.destroy_channel.key = ua_chan->key;
 347
 348         pthread_mutex_lock(socket->lock);
 349         health_code_update();
 350
 351         ret = consumer_send_msg(socket, &msg);
 352         if (ret < 0) {
 353                 goto error;
 354         }
 355
 356 error:
 357         health_code_update();
 358         pthread_mutex_unlock(socket->lock);
 359         return ret;
 360 }
 361
 362 /*
 363  * Send a given stream to UST tracer.
 364  *
 365  * On success return 0 else a negative value.
 366  */
 367 int ust_consumer_send_stream_to_ust(struct ust_app *app,
 368                 struct ust_app_channel *channel, struct ust_app_stream *stream)
 369 {
 370         int ret;
 371
 372         assert(app);
 373         assert(stream);
 374         assert(channel);
 375
 376         DBG2("UST consumer send stream to app %d", app->sock);
 377
 378         /* Relay stream to application. */
 379         pthread_mutex_lock(&app->sock_lock);
 380         ret = ustctl_send_stream_to_ust(app->sock, channel->obj, stream->obj);
 381         pthread_mutex_unlock(&app->sock_lock);
 382         if (ret < 0) {
 383                 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
 384                         ERR("ustctl send stream handle %d to app pid: %d with ret %d",
 385                                         stream->obj->handle, app->pid, ret);
 386                 } else {
 387                         DBG3("UST app send stream to ust failed. Application is dead.");
 388                 }
 389                 goto error;
 390         }
 391         channel->handle = channel->obj->handle;
 392
 393 error:
 394         return ret;
 395 }
 396
 397 /*
 398  * Send channel previously received from the consumer to the UST tracer.
 399  *
 400  * On success return 0 else a negative value.
 401  */
 402 int ust_consumer_send_channel_to_ust(struct ust_app *app,
 403                 struct ust_app_session *ua_sess, struct ust_app_channel *channel)
 404 {
 405         int ret;
 406
 407         assert(app);
 408         assert(ua_sess);
 409         assert(channel);
 410         assert(channel->obj);
 411
 412         DBG2("UST app send channel to sock %d pid %d (name: %s, key: %" PRIu64 ")",
 413                         app->sock, app->pid, channel->name, channel->tracing_channel_id);
 414
 415         /* Send stream to application. */
 416         pthread_mutex_lock(&app->sock_lock);
 417         ret = ustctl_send_channel_to_ust(app->sock, ua_sess->handle, channel->obj);
 418         pthread_mutex_unlock(&app->sock_lock);
 419         if (ret < 0) {
 420                 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
 421                         ERR("Error ustctl send channel %s to app pid: %d with ret %d",
 422                                         channel->name, app->pid, ret);
 423                 } else {
 424                         DBG3("UST app send channel to ust failed. Application is dead.");
 425                 }
 426                 goto error;
 427         }
 428
 429 error:
 430         return ret;
 431 }
 432
 433 /*
 434  * Handle the metadata requests from the UST consumer
 435  *
 436  * Return 0 on success else a negative value.
 437  */
 438 int ust_consumer_metadata_request(struct consumer_socket *socket)
 439 {
 440         int ret;
 441         ssize_t ret_push;
 442         struct lttcomm_metadata_request_msg request;
 443         struct buffer_reg_uid *reg_uid;
 444         struct ust_registry_session *ust_reg;
 445         struct lttcomm_consumer_msg msg;
 446
 447         assert(socket);
 448
 449         rcu_read_lock();
 450         health_code_update();
 451
 452         /* Wait for a metadata request */
 453         pthread_mutex_lock(socket->lock);
 454         ret = consumer_socket_recv(socket, &request, sizeof(request));
 455         pthread_mutex_unlock(socket->lock);
 456         if (ret < 0) {
 457                 goto end;
 458         }
 459
 460         DBG("Metadata request received for session %" PRIu64 ", key %" PRIu64,
 461                         request.session_id, request.key);
 462
 463         reg_uid = buffer_reg_uid_find(request.session_id,
 464                         request.bits_per_long, request.uid);
 465         if (reg_uid) {
 466                 ust_reg = reg_uid->registry->reg.ust;
 467         } else {
 468                 struct buffer_reg_pid *reg_pid =
 469                         buffer_reg_pid_find(request.session_id_per_pid);
 470                 if (!reg_pid) {
 471                         DBG("PID registry not found for session id %" PRIu64,
 472                                         request.session_id_per_pid);
 473
 474                         memset(&msg, 0, sizeof(msg));
 475                         msg.cmd_type = LTTNG_ERR_UND;
 476                         pthread_mutex_lock(socket->lock);
 477                         (void) consumer_send_msg(socket, &msg);
 478                         pthread_mutex_unlock(socket->lock);
 479                         /*
 480                          * This is possible since the session might have been destroyed
 481                          * during a consumer metadata request. So here, return gracefully
 482                          * because the destroy session will push the remaining metadata to
 483                          * the consumer.
 484                          */
 485                         ret = 0;
 486                         goto end;
 487                 }
 488                 ust_reg = reg_pid->registry->reg.ust;
 489         }
 490         assert(ust_reg);
 491
 492         pthread_mutex_lock(&ust_reg->lock);
 493         ret_push = ust_app_push_metadata(ust_reg, socket, 1);
 494         pthread_mutex_unlock(&ust_reg->lock);
 495         if (ret_push == -EPIPE) {
 496                 DBG("Application or relay closed while pushing metadata");
 497         } else if (ret_push < 0) {
 498                 ERR("Pushing metadata");
 499                 ret = -1;
 500                 goto end;
 501         } else {
 502                 DBG("UST Consumer metadata pushed successfully");
 503         }
 504         ret = 0;
 505
 506 end:
 507         rcu_read_unlock();
 508         return ret;
 509 }