src/common/ust-consumer/ust-consumer.c

   1 /*
   2  * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *
   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.
   8  *
   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.
  13  *
  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.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <assert.h>
  21 #include <lttng/ust-ctl.h>
  22 #include <poll.h>
  23 #include <pthread.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <sys/mman.h>
  27 #include <sys/socket.h>
  28 #include <sys/stat.h>
  29 #include <sys/types.h>
  30 #include <inttypes.h>
  31 #include <unistd.h>
  32
  33 #include <common/common.h>
  34 #include <common/sessiond-comm/sessiond-comm.h>
  35 #include <common/relayd/relayd.h>
  36 #include <common/compat/fcntl.h>
  37
  38 #include "ust-consumer.h"
  39
  40 extern struct lttng_consumer_global_data consumer_data;
  41 extern int consumer_poll_timeout;
  42 extern volatile int consumer_quit;
  43
  44 /*
  45  * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
  46  * compiled out, we isolate it in this library.
  47  */
  48 int lttng_ustctl_get_mmap_read_offset(struct lttng_ust_shm_handle *handle,
  49                 struct lttng_ust_lib_ring_buffer *buf, unsigned long *off)
  50 {
  51         return ustctl_get_mmap_read_offset(handle, buf, off);
  52 };
  53
  54 /*
  55  * Take a snapshot for a specific fd
  56  *
  57  * Returns 0 on success, < 0 on error
  58  */
  59 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_local_data *ctx,
  60                 struct lttng_consumer_stream *stream)
  61 {
  62         int ret = 0;
  63
  64         ret = ustctl_snapshot(stream->chan->handle, stream->buf);
  65         if (ret != 0) {
  66                 errno = -ret;
  67                 PERROR("Getting sub-buffer snapshot.");
  68         }
  69
  70         return ret;
  71 }
  72
  73 /*
  74  * Get the produced position
  75  *
  76  * Returns 0 on success, < 0 on error
  77  */
  78 int lttng_ustconsumer_get_produced_snapshot(
  79                 struct lttng_consumer_local_data *ctx,
  80                 struct lttng_consumer_stream *stream,
  81                 unsigned long *pos)
  82 {
  83         int ret;
  84
  85         ret = ustctl_snapshot_get_produced(stream->chan->handle,
  86                         stream->buf, pos);
  87         if (ret != 0) {
  88                 errno = -ret;
  89                 PERROR("kernctl_snapshot_get_produced");
  90         }
  91
  92         return ret;
  93 }
  94
  95 /*
  96  * Receive command from session daemon and process it.
  97  *
  98  * Return 1 on success else a negative value or 0.
  99  */
 100 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 101                 int sock, struct pollfd *consumer_sockpoll)
 102 {
 103         ssize_t ret;
 104         struct lttcomm_consumer_msg msg;
 105
 106         ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
 107         if (ret != sizeof(msg)) {
 108                 DBG("Consumer received unexpected message size %zd (expects %zu)",
 109                         ret, sizeof(msg));
 110                 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD);
 111                 return ret;
 112         }
 113         if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
 114                 return -ENOENT;
 115         }
 116
 117         /* relayd needs RCU read-side lock */
 118         rcu_read_lock();
 119
 120         switch (msg.cmd_type) {
 121         case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
 122         {
 123                 ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
 124                                 msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
 125                                 &msg.u.relayd_sock.sock);
 126                 goto end_nosignal;
 127         }
 128         case LTTNG_CONSUMER_ADD_CHANNEL:
 129         {
 130                 struct lttng_consumer_channel *new_channel;
 131                 int fds[1];
 132                 size_t nb_fd = 1;
 133
 134                 DBG("UST Consumer adding channel");
 135
 136                 /* block */
 137                 if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
 138                         rcu_read_unlock();
 139                         return -EINTR;
 140                 }
 141                 ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd);
 142                 if (ret != sizeof(fds)) {
 143                         lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD);
 144                         rcu_read_unlock();
 145                         return ret;
 146                 }
 147
 148                 DBG("consumer_add_channel %d", msg.u.channel.channel_key);
 149
 150                 new_channel = consumer_allocate_channel(msg.u.channel.channel_key,
 151                                 fds[0], -1,
 152                                 msg.u.channel.mmap_len,
 153                                 msg.u.channel.max_sb_size,
 154                                 msg.u.channel.nb_init_streams);
 155                 if (new_channel == NULL) {
 156                         lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
 157                         goto end_nosignal;
 158                 }
 159                 if (ctx->on_recv_channel != NULL) {
 160                         ret = ctx->on_recv_channel(new_channel);
 161                         if (ret == 0) {
 162                                 consumer_add_channel(new_channel);
 163                         } else if (ret < 0) {
 164                                 goto end_nosignal;
 165                         }
 166                 } else {
 167                         consumer_add_channel(new_channel);
 168                 }
 169                 goto end_nosignal;
 170         }
 171         case LTTNG_CONSUMER_ADD_STREAM:
 172         {
 173                 struct lttng_consumer_stream *new_stream;
 174                 int fds[2], stream_pipe;
 175                 size_t nb_fd = 2;
 176                 struct consumer_relayd_sock_pair *relayd = NULL;
 177                 int alloc_ret = 0;
 178
 179                 DBG("UST Consumer adding stream");
 180
 181                 /* block */
 182                 if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
 183                         rcu_read_unlock();
 184                         return -EINTR;
 185                 }
 186                 ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd);
 187                 if (ret != sizeof(fds)) {
 188                         lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD);
 189                         rcu_read_unlock();
 190                         return ret;
 191                 }
 192
 193                 DBG("Consumer command ADD_STREAM chan %d stream %d",
 194                                 msg.u.stream.channel_key, msg.u.stream.stream_key);
 195
 196                 assert(msg.u.stream.output == LTTNG_EVENT_MMAP);
 197                 new_stream = consumer_allocate_stream(msg.u.stream.channel_key,
 198                                 msg.u.stream.stream_key,
 199                                 fds[0], fds[1],
 200                                 msg.u.stream.state,
 201                                 msg.u.stream.mmap_len,
 202                                 msg.u.stream.output,
 203                                 msg.u.stream.path_name,
 204                                 msg.u.stream.uid,
 205                                 msg.u.stream.gid,
 206                                 msg.u.stream.net_index,
 207                                 msg.u.stream.metadata_flag,
 208                                 &alloc_ret);
 209                 if (new_stream == NULL) {
 210                         switch (alloc_ret) {
 211                         case -ENOMEM:
 212                         case -EINVAL:
 213                         default:
 214                                 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
 215                                 break;
 216                         case -ENOENT:
 217                                 /*
 218                                  * We could not find the channel. Can happen if cpu hotplug
 219                                  * happens while tearing down.
 220                                  */
 221                                 DBG3("Could not find channel");
 222                                 break;
 223                         }
 224                         goto end_nosignal;
 225                 }
 226
 227                 /* The stream is not metadata. Get relayd reference if exists. */
 228                 relayd = consumer_find_relayd(msg.u.stream.net_index);
 229                 if (relayd != NULL) {
 230                         pthread_mutex_lock(&relayd->ctrl_sock_mutex);
 231                         /* Add stream on the relayd */
 232                         ret = relayd_add_stream(&relayd->control_sock,
 233                                         msg.u.stream.name, msg.u.stream.path_name,
 234                                         &new_stream->relayd_stream_id);
 235                         pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
 236                         if (ret < 0) {
 237                                 consumer_del_stream(new_stream, NULL);
 238                                 goto end_nosignal;
 239                         }
 240                 } else if (msg.u.stream.net_index != -1) {
 241                         ERR("Network sequence index %d unknown. Not adding stream.",
 242                                         msg.u.stream.net_index);
 243                         consumer_del_stream(new_stream, NULL);
 244                         goto end_nosignal;
 245                 }
 246
 247                 /* Do actions once stream has been received. */
 248                 if (ctx->on_recv_stream) {
 249                         ret = ctx->on_recv_stream(new_stream);
 250                         if (ret < 0) {
 251                                 consumer_del_stream(new_stream, NULL);
 252                                 goto end_nosignal;
 253                         }
 254                 }
 255
 256                 /* Get the right pipe where the stream will be sent. */
 257                 if (new_stream->metadata_flag) {
 258                         stream_pipe = ctx->consumer_metadata_pipe[1];
 259                 } else {
 260                         stream_pipe = ctx->consumer_data_pipe[1];
 261                 }
 262
 263                 do {
 264                         ret = write(stream_pipe, &new_stream, sizeof(new_stream));
 265                 } while (ret < 0 && errno == EINTR);
 266                 if (ret < 0) {
 267                         PERROR("Consumer write %s stream to pipe %d",
 268                                         new_stream->metadata_flag ? "metadata" : "data",
 269                                         stream_pipe);
 270                         consumer_del_stream(new_stream, NULL);
 271                         goto end_nosignal;
 272                 }
 273
 274                 DBG("UST consumer ADD_STREAM %s (%d,%d) with relayd id %" PRIu64,
 275                                 msg.u.stream.path_name, fds[0], fds[1],
 276                                 new_stream->relayd_stream_id);
 277                 break;
 278         }
 279         case LTTNG_CONSUMER_DESTROY_RELAYD:
 280         {
 281                 uint64_t index = msg.u.destroy_relayd.net_seq_idx;
 282                 struct consumer_relayd_sock_pair *relayd;
 283
 284                 DBG("UST consumer destroying relayd %" PRIu64, index);
 285
 286                 /* Get relayd reference if exists. */
 287                 relayd = consumer_find_relayd(index);
 288                 if (relayd == NULL) {
 289                         ERR("Unable to find relayd %" PRIu64, index);
 290                         goto end_nosignal;
 291                 }
 292
 293                 /*
 294                  * Each relayd socket pair has a refcount of stream attached to it
 295                  * which tells if the relayd is still active or not depending on the
 296                  * refcount value.
 297                  *
 298                  * This will set the destroy flag of the relayd object and destroy it
 299                  * if the refcount reaches zero when called.
 300                  *
 301                  * The destroy can happen either here or when a stream fd hangs up.
 302                  */
 303                 consumer_flag_relayd_for_destroy(relayd);
 304
 305                 goto end_nosignal;
 306         }
 307         case LTTNG_CONSUMER_UPDATE_STREAM:
 308         {
 309                 rcu_read_unlock();
 310                 return -ENOSYS;
 311         }
 312         default:
 313                 break;
 314         }
 315
 316 end_nosignal:
 317         rcu_read_unlock();
 318
 319         /*
 320          * Return 1 to indicate success since the 0 value can be a socket
 321          * shutdown during the recv() or send() call.
 322          */
 323         return 1;
 324 }
 325
 326 int lttng_ustconsumer_allocate_channel(struct lttng_consumer_channel *chan)
 327 {
 328         struct lttng_ust_object_data obj;
 329
 330         obj.handle = -1;
 331         obj.shm_fd = chan->shm_fd;
 332         obj.wait_fd = chan->wait_fd;
 333         obj.memory_map_size = chan->mmap_len;
 334         chan->handle = ustctl_map_channel(&obj);
 335         if (!chan->handle) {
 336                 return -ENOMEM;
 337         }
 338         chan->wait_fd_is_copy = 1;
 339         chan->shm_fd = -1;
 340
 341         return 0;
 342 }
 343
 344 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
 345 {
 346         ustctl_flush_buffer(stream->chan->handle, stream->buf, 0);
 347         stream->hangup_flush_done = 1;
 348 }
 349
 350 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
 351 {
 352         ustctl_unmap_channel(chan->handle);
 353 }
 354
 355 int lttng_ustconsumer_add_stream(struct lttng_consumer_stream *stream)
 356 {
 357         struct lttng_ust_object_data obj;
 358         int ret;
 359
 360         obj.handle = -1;
 361         obj.shm_fd = stream->shm_fd;
 362         obj.wait_fd = stream->wait_fd;
 363         obj.memory_map_size = stream->mmap_len;
 364         ret = ustctl_add_stream(stream->chan->handle, &obj);
 365         if (ret) {
 366                 ERR("UST ctl add_stream failed with ret %d", ret);
 367                 goto error;
 368         }
 369
 370         stream->buf = ustctl_open_stream_read(stream->chan->handle, stream->cpu);
 371         if (!stream->buf) {
 372                 ERR("UST ctl open_stream_read failed");
 373                 ret = -EBUSY;
 374                 goto error;
 375         }
 376
 377         /* ustctl_open_stream_read has closed the shm fd. */
 378         stream->wait_fd_is_copy = 1;
 379         stream->shm_fd = -1;
 380
 381         stream->mmap_base = ustctl_get_mmap_base(stream->chan->handle, stream->buf);
 382         if (!stream->mmap_base) {
 383                 ERR("UST ctl get_mmap_base failed");
 384                 ret = -EINVAL;
 385                 goto mmap_error;
 386         }
 387
 388         return 0;
 389
 390 mmap_error:
 391         ustctl_close_stream_read(stream->chan->handle, stream->buf);
 392 error:
 393         return ret;
 394 }
 395
 396 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
 397 {
 398         ustctl_close_stream_read(stream->chan->handle, stream->buf);
 399 }
 400
 401
 402 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
 403                 struct lttng_consumer_local_data *ctx)
 404 {
 405         unsigned long len, subbuf_size, padding;
 406         int err;
 407         long ret = 0;
 408         struct lttng_ust_shm_handle *handle;
 409         struct lttng_ust_lib_ring_buffer *buf;
 410         char dummy;
 411         ssize_t readlen;
 412
 413         DBG("In read_subbuffer (wait_fd: %d, stream key: %d)",
 414                 stream->wait_fd, stream->key);
 415
 416         /* We can consume the 1 byte written into the wait_fd by UST */
 417         if (!stream->hangup_flush_done) {
 418                 do {
 419                         readlen = read(stream->wait_fd, &dummy, 1);
 420                 } while (readlen == -1 && errno == EINTR);
 421                 if (readlen == -1) {
 422                         ret = readlen;
 423                         goto end;
 424                 }
 425         }
 426
 427         buf = stream->buf;
 428         handle = stream->chan->handle;
 429         /* Get the next subbuffer */
 430         err = ustctl_get_next_subbuf(handle, buf);
 431         if (err != 0) {
 432                 ret = err;      /* ustctl_get_next_subbuf returns negative, caller expect positive. */
 433                 /*
 434                  * This is a debug message even for single-threaded consumer,
 435                  * because poll() have more relaxed criterions than get subbuf,
 436                  * so get_subbuf may fail for short race windows where poll()
 437                  * would issue wakeups.
 438                  */
 439                 DBG("Reserving sub buffer failed (everything is normal, "
 440                                 "it is due to concurrency)");
 441                 goto end;
 442         }
 443         assert(stream->output == LTTNG_EVENT_MMAP);
 444         /* Get the full padded subbuffer size */
 445         err = ustctl_get_padded_subbuf_size(handle, buf, &len);
 446         assert(err == 0);
 447
 448         /* Get subbuffer data size (without padding) */
 449         err = ustctl_get_subbuf_size(handle, buf, &subbuf_size);
 450         assert(err == 0);
 451
 452         /* Make sure we don't get a subbuffer size bigger than the padded */
 453         assert(len >= subbuf_size);
 454
 455         padding = len - subbuf_size;
 456         /* write the subbuffer to the tracefile */
 457         ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding);
 458         /*
 459          * The mmap operation should write subbuf_size amount of data when network
 460          * streaming or the full padding (len) size when we are _not_ streaming.
 461          */
 462         if ((ret != subbuf_size && stream->net_seq_idx != -1) ||
 463                         (ret != len && stream->net_seq_idx == -1)) {
 464                 /*
 465                  * Display the error but continue processing to try to release the
 466                  * subbuffer
 467                  */
 468                 ERR("Error writing to tracefile "
 469                                 "(ret: %zd != len: %lu != subbuf_size: %lu)",
 470                                 ret, len, subbuf_size);
 471         }
 472         err = ustctl_put_next_subbuf(handle, buf);
 473         assert(err == 0);
 474 end:
 475         return ret;
 476 }
 477
 478 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
 479 {
 480         int ret;
 481
 482         /* Opening the tracefile in write mode */
 483         if (stream->path_name != NULL && stream->net_seq_idx == -1) {
 484                 ret = run_as_open(stream->path_name,
 485                                 O_WRONLY|O_CREAT|O_TRUNC,
 486                                 S_IRWXU|S_IRWXG|S_IRWXO,
 487                                 stream->uid, stream->gid);
 488                 if (ret < 0) {
 489                         ERR("Opening %s", stream->path_name);
 490                         PERROR("open");
 491                         goto error;
 492                 }
 493                 stream->out_fd = ret;
 494         }
 495
 496         ret = lttng_ustconsumer_add_stream(stream);
 497         if (ret) {
 498                 consumer_del_stream(stream, NULL);
 499                 ret = -1;
 500                 goto error;
 501         }
 502
 503         /* we return 0 to let the library handle the FD internally */
 504         return 0;
 505
 506 error:
 507         return ret;
 508 }