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 _GNU_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.h>
  28 #include <common/defaults.h>
  29
  30 #include "consumer.h"
  31 #include "ust-consumer.h"
  32
  33 /*
  34  * Return allocated full pathname of the session using the consumer trace path
  35  * and subdir if available. On a successful allocation, the directory of the
  36  * trace is created with the session credentials.
  37  *
  38  * The caller can safely free(3) the returned value. On error, NULL is
  39  * returned.
  40  */
  41 static char *setup_trace_path(struct consumer_output *consumer,
  42                 struct ust_app_session *ua_sess)
  43 {
  44         int ret;
  45         char *pathname;
  46
  47         assert(consumer);
  48         assert(ua_sess);
  49
  50         health_code_update();
  51
  52         /* Allocate our self the string to make sure we never exceed PATH_MAX. */
  53         pathname = zmalloc(PATH_MAX);
  54         if (!pathname) {
  55                 goto error;
  56         }
  57
  58         /* Get correct path name destination */
  59         if (consumer->type == CONSUMER_DST_LOCAL) {
  60                 /* Set application path to the destination path */
  61                 ret = snprintf(pathname, PATH_MAX, "%s/%s/%s",
  62                                 consumer->dst.trace_path, consumer->subdir, ua_sess->path);
  63                 if (ret < 0) {
  64                         PERROR("snprintf channel path");
  65                         goto error;
  66                 }
  67
  68                 /* Create directory. Ignore if exist. */
  69                 ret = run_as_mkdir_recursive(pathname, S_IRWXU | S_IRWXG, ua_sess->uid,
  70                                 ua_sess->gid);
  71                 if (ret < 0) {
  72                         if (ret != -EEXIST) {
  73                                 ERR("Trace directory creation error");
  74                                 goto error;
  75                         }
  76                 }
  77         } else {
  78                 ret = snprintf(pathname, PATH_MAX, "%s/%s", consumer->subdir,
  79                                 ua_sess->path);
  80                 if (ret < 0) {
  81                         PERROR("snprintf channel path");
  82                         goto error;
  83                 }
  84         }
  85
  86         return pathname;
  87
  88 error:
  89         free(pathname);
  90         return NULL;
  91 }
  92
  93 /*
  94  * Send a single channel to the consumer using command ADD_CHANNEL.
  95  *
  96  * Consumer socket MUST be acquired before calling this.
  97  */
  98 static int ask_channel_creation(struct ust_app_session *ua_sess,
  99                 struct ust_app_channel *ua_chan, struct consumer_output *consumer,
 100                 struct consumer_socket *socket)
 101 {
 102         int ret;
 103         uint64_t key;
 104         char *pathname = NULL;
 105         struct lttcomm_consumer_msg msg;
 106
 107         assert(ua_sess);
 108         assert(ua_chan);
 109         assert(socket);
 110         assert(consumer);
 111
 112         DBG2("Asking UST consumer for channel");
 113
 114         /* Get and create full trace path of session. */
 115         pathname = setup_trace_path(consumer, ua_sess);
 116         if (!pathname) {
 117                 ret = -1;
 118                 goto error;
 119         }
 120
 121         consumer_init_ask_channel_comm_msg(&msg,
 122                         ua_chan->attr.subbuf_size,
 123                         ua_chan->attr.num_subbuf,
 124                         ua_chan->attr.overwrite,
 125                         ua_chan->attr.switch_timer_interval,
 126                         ua_chan->attr.read_timer_interval,
 127                         (int) ua_chan->attr.output,
 128                         (int) ua_chan->attr.type,
 129                         ua_sess->id,
 130                         pathname,
 131                         ua_chan->name,
 132                         ua_sess->uid,
 133                         ua_sess->gid,
 134                         consumer->net_seq_index,
 135                         ua_chan->key,
 136                         ua_sess->registry.uuid);
 137
 138         health_code_update();
 139
 140         ret = lttcomm_send_unix_sock(socket->fd, &msg, sizeof(msg));
 141         if (ret < 0) {
 142                 goto error;
 143         }
 144
 145         ret = consumer_recv_status_channel(socket, &key,
 146                         &ua_chan->expected_stream_count);
 147         if (ret < 0) {
 148                 goto error;
 149         }
 150         /* Communication protocol error. */
 151         assert(key == ua_chan->key);
 152         /* We need at least one where 1 stream for 1 cpu. */
 153         assert(ua_chan->expected_stream_count > 0);
 154
 155         DBG2("UST ask channel %" PRIu64 " successfully done with %u stream(s)", key,
 156                         ua_chan->expected_stream_count);
 157
 158 error:
 159         free(pathname);
 160         health_code_update();
 161         return ret;
 162 }
 163
 164 /*
 165  * Ask consumer to create a channel for a given session.
 166  *
 167  * Returns 0 on success else a negative value.
 168  */
 169 int ust_consumer_ask_channel(struct ust_app_session *ua_sess,
 170                 struct ust_app_channel *ua_chan, struct consumer_output *consumer,
 171                 struct consumer_socket *socket)
 172 {
 173         int ret;
 174
 175         assert(ua_sess);
 176         assert(ua_chan);
 177         assert(consumer);
 178         assert(socket);
 179         assert(socket->fd >= 0);
 180
 181         pthread_mutex_lock(socket->lock);
 182
 183         ret = ask_channel_creation(ua_sess, ua_chan, consumer, socket);
 184         if (ret < 0) {
 185                 goto error;
 186         }
 187
 188 error:
 189         pthread_mutex_unlock(socket->lock);
 190         return ret;
 191 }
 192
 193 /*
 194  * Send a get channel command to consumer using the given channel key.  The
 195  * channel object is populated and the stream list.
 196  *
 197  * Return 0 on success else a negative value.
 198  */
 199 int ust_consumer_get_channel(struct consumer_socket *socket,
 200                 struct ust_app_channel *ua_chan)
 201 {
 202         int ret;
 203         struct lttcomm_consumer_msg msg;
 204
 205         assert(ua_chan);
 206         assert(socket);
 207         assert(socket->fd >= 0);
 208
 209         msg.cmd_type = LTTNG_CONSUMER_GET_CHANNEL;
 210         msg.u.get_channel.key = ua_chan->key;
 211
 212         pthread_mutex_lock(socket->lock);
 213         health_code_update();
 214
 215         /* Send command and wait for OK reply. */
 216         ret = consumer_send_msg(socket, &msg);
 217         if (ret < 0) {
 218                 goto error;
 219         }
 220
 221         /* First, get the channel from consumer. */
 222         ret = ustctl_recv_channel_from_consumer(socket->fd, &ua_chan->obj);
 223         if (ret < 0) {
 224                 if (ret != -EPIPE) {
 225                         ERR("Error recv channel from consumer %d with ret %d",
 226                                         socket->fd, ret);
 227                 } else {
 228                         DBG3("UST app recv channel from consumer. Consumer is dead.");
 229                 }
 230                 goto error;
 231         }
 232
 233         /* Next, get all streams. */
 234         while (1) {
 235                 struct ust_app_stream *stream;
 236
 237                 /* Create UST stream */
 238                 stream = ust_app_alloc_stream();
 239                 if (stream == NULL) {
 240                         ret = -ENOMEM;
 241                         goto error;
 242                 }
 243
 244                 /* Stream object is populated by this call if successful. */
 245                 ret = ustctl_recv_stream_from_consumer(socket->fd, &stream->obj);
 246                 if (ret < 0) {
 247                         free(stream);
 248                         if (ret == -LTTNG_UST_ERR_NOENT) {
 249                                 DBG3("UST app consumer has no more stream available");
 250                                 ret = 0;
 251                                 break;
 252                         }
 253                         if (ret != -EPIPE) {
 254                                 ERR("Recv stream from consumer %d with ret %d",
 255                                                 socket->fd, ret);
 256                         } else {
 257                                 DBG3("UST app recv stream from consumer. Consumer is dead.");
 258                         }
 259                         goto error;
 260                 }
 261
 262                 /* Order is important this is why a list is used. */
 263                 cds_list_add_tail(&stream->list, &ua_chan->streams.head);
 264                 ua_chan->streams.count++;
 265
 266                 DBG2("UST app stream %d received succesfully", ua_chan->streams.count);
 267         }
 268
 269         /* This MUST match or else we have a synchronization problem. */
 270         assert(ua_chan->expected_stream_count == ua_chan->streams.count);
 271
 272         /* Wait for confirmation that we can proceed with the streams. */
 273         ret = consumer_recv_status_reply(socket);
 274         if (ret < 0) {
 275                 goto error;
 276         }
 277
 278 error:
 279         health_code_update();
 280         pthread_mutex_unlock(socket->lock);
 281         return ret;
 282 }
 283
 284 /*
 285  * Send a destroy channel command to consumer using the given channel key.
 286  *
 287  * Note that this command MUST be used prior to a successful
 288  * LTTNG_CONSUMER_GET_CHANNEL because once this command is done successfully,
 289  * the streams are dispatched to the consumer threads and MUST be teardown
 290  * through the hang up process.
 291  *
 292  * Return 0 on success else a negative value.
 293  */
 294 int ust_consumer_destroy_channel(struct consumer_socket *socket,
 295                 struct ust_app_channel *ua_chan)
 296 {
 297         int ret;
 298         struct lttcomm_consumer_msg msg;
 299
 300         assert(ua_chan);
 301         assert(socket);
 302         assert(socket->fd >= 0);
 303
 304         msg.cmd_type = LTTNG_CONSUMER_DESTROY_CHANNEL;
 305         msg.u.destroy_channel.key = ua_chan->key;
 306
 307         pthread_mutex_lock(socket->lock);
 308         health_code_update();
 309
 310         ret = consumer_send_msg(socket, &msg);
 311         if (ret < 0) {
 312                 goto error;
 313         }
 314
 315 error:
 316         health_code_update();
 317         pthread_mutex_unlock(socket->lock);
 318         return ret;
 319 }
 320
 321 /*
 322  * Send a given stream to UST tracer.
 323  *
 324  * On success return 0 else a negative value.
 325  */
 326 int ust_consumer_send_stream_to_ust(struct ust_app *app,
 327                 struct ust_app_channel *channel, struct ust_app_stream *stream)
 328 {
 329         int ret;
 330
 331         assert(app);
 332         assert(stream);
 333         assert(channel);
 334
 335         DBG2("UST consumer send stream to app %d", app->sock);
 336
 337         /* Relay stream to application. */
 338         ret = ustctl_send_stream_to_ust(app->sock, channel->obj, stream->obj);
 339         if (ret < 0) {
 340                 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
 341                         ERR("Error ustctl send stream %s to app pid: %d with ret %d",
 342                                         stream->name, app->pid, ret);
 343                 } else {
 344                         DBG3("UST app send stream to ust failed. Application is dead.");
 345                 }
 346                 goto error;
 347         }
 348         channel->handle = channel->obj->handle;
 349
 350 error:
 351         return ret;
 352 }
 353
 354 /*
 355  * Send channel previously received from the consumer to the UST tracer.
 356  *
 357  * On success return 0 else a negative value.
 358  */
 359 int ust_consumer_send_channel_to_ust(struct ust_app *app,
 360                 struct ust_app_session *ua_sess, struct ust_app_channel *channel)
 361 {
 362         int ret;
 363
 364         assert(app);
 365         assert(ua_sess);
 366         assert(channel);
 367         assert(channel->obj);
 368
 369         DBG2("UST app send channel to app sock %d pid %d (name: %s, key: %lu)",
 370                         app->sock, app->pid, channel->name, channel->key);
 371
 372         /* Send stream to application. */
 373         ret = ustctl_send_channel_to_ust(app->sock, ua_sess->handle, channel->obj);
 374         if (ret < 0) {
 375                 if (ret != -EPIPE && ret != -LTTNG_UST_ERR_EXITING) {
 376                         ERR("Error ustctl send channel %s to app pid: %d with ret %d",
 377                                         channel->name, app->pid, ret);
 378                 } else {
 379                         DBG3("UST app send channel to ust failed. Application is dead.");
 380                 }
 381                 goto error;
 382         }
 383
 384 error:
 385         return ret;
 386 }
 387
 388 /*
 389  * Send metadata string to consumer.
 390  *
 391  * Return 0 on success else a negative value.
 392  */
 393 int ust_consumer_push_metadata(struct consumer_socket *socket,
 394                 struct ust_app_session *ua_sess, char *metadata_str,
 395                 size_t len, size_t target_offset)
 396 {
 397         int ret;
 398         struct lttcomm_consumer_msg msg;
 399
 400         assert(socket);
 401         assert(socket->fd >= 0);
 402         assert(ua_sess);
 403         assert(ua_sess->metadata);
 404
 405         DBG2("UST consumer push metadata to consumer socket %d", socket->fd);
 406
 407         msg.cmd_type = LTTNG_CONSUMER_PUSH_METADATA;
 408         msg.u.push_metadata.key = ua_sess->metadata->key;
 409         msg.u.push_metadata.target_offset = target_offset;
 410         msg.u.push_metadata.len = len;
 411
 412         /*
 413          * TODO: reenable these locks when the consumerd gets the ability to
 414          * reorder the metadata it receives. This fits with locking in
 415          * src/bin/lttng-sessiond/ust-app.c:push_metadata()
 416          *
 417          * pthread_mutex_lock(socket->lock);
 418          */
 419
 420         health_code_update();
 421         ret = consumer_send_msg(socket, &msg);
 422         if (ret < 0) {
 423                 goto error;
 424         }
 425
 426         DBG3("UST consumer push metadata on sock %d of len %lu", socket->fd, len);
 427
 428         ret = lttcomm_send_unix_sock(socket->fd, metadata_str, len);
 429         if (ret < 0) {
 430                 fprintf(stderr, "send error: %d\n", ret);
 431                 goto error;
 432         }
 433
 434         health_code_update();
 435         ret = consumer_recv_status_reply(socket);
 436         if (ret < 0) {
 437                 goto error;
 438         }
 439
 440 error:
 441         health_code_update();
 442         /*
 443          * pthread_mutex_unlock(socket->lock);
 444          */
 445         return ret;
 446 }
 447
 448 /*
 449  * Send a close metdata command to consumer using the given channel key.
 450  *
 451  * Return 0 on success else a negative value.
 452  */
 453 int ust_consumer_close_metadata(struct consumer_socket *socket,
 454                 struct ust_app_channel *ua_chan)
 455 {
 456         int ret;
 457         struct lttcomm_consumer_msg msg;
 458
 459         assert(ua_chan);
 460         assert(socket);
 461         assert(socket->fd >= 0);
 462
 463         DBG2("UST consumer close metadata channel key %lu", ua_chan->key);
 464
 465         msg.cmd_type = LTTNG_CONSUMER_CLOSE_METADATA;
 466         msg.u.close_metadata.key = ua_chan->key;
 467
 468         pthread_mutex_lock(socket->lock);
 469         health_code_update();
 470
 471         ret = consumer_send_msg(socket, &msg);
 472         if (ret < 0) {
 473                 goto error;
 474         }
 475
 476 error:
 477         health_code_update();
 478         pthread_mutex_unlock(socket->lock);
 479         return ret;
 480 }
 481
 482 /*
 483  * Send a setup metdata command to consumer using the given channel key.
 484  *
 485  * Return 0 on success else a negative value.
 486  */
 487 int ust_consumer_setup_metadata(struct consumer_socket *socket,
 488                 struct ust_app_channel *ua_chan)
 489 {
 490         int ret;
 491         struct lttcomm_consumer_msg msg;
 492
 493         assert(ua_chan);
 494         assert(socket);
 495         assert(socket->fd >= 0);
 496
 497         DBG2("UST consumer setup metadata channel key %lu", ua_chan->key);
 498
 499         msg.cmd_type = LTTNG_CONSUMER_SETUP_METADATA;
 500         msg.u.setup_metadata.key = ua_chan->key;
 501
 502         pthread_mutex_lock(socket->lock);
 503         health_code_update();
 504
 505         ret = consumer_send_msg(socket, &msg);
 506         if (ret < 0) {
 507                 goto error;
 508         }
 509
 510 error:
 511         health_code_update();
 512         pthread_mutex_unlock(socket->lock);
 513         return ret;
 514 }