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 <poll.h>
  22 #include <pthread.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <sys/mman.h>
  26 #include <sys/socket.h>
  27 #include <sys/stat.h>
  28 #include <sys/types.h>
  29 #include <unistd.h>
  30 #include <lttng/ust-ctl.h>
  31
  32 #include <common/common.h>
  33 #include <common/sessiond-comm/sessiond-comm.h>
  34 #include <common/relayd/relayd.h>
  35 #include <common/compat/fcntl.h>
  36
  37 #include "ust-consumer.h"
  38
  39 extern struct lttng_consumer_global_data consumer_data;
  40 extern int consumer_poll_timeout;
  41 extern volatile int consumer_quit;
  42
  43 /*
  44  * Mmap the ring buffer, read it and write the data to the tracefile.
  45  *
  46  * Returns the number of bytes written, else negative value on error.
  47  */
  48 ssize_t lttng_ustconsumer_on_read_subbuffer_mmap(
  49                 struct lttng_consumer_local_data *ctx,
  50                 struct lttng_consumer_stream *stream, unsigned long len)
  51 {
  52         unsigned long mmap_offset;
  53         long ret = 0, written = 0;
  54         off_t orig_offset = stream->out_fd_offset;
  55         int outfd = stream->out_fd;
  56         uint64_t metadata_id;
  57         struct consumer_relayd_sock_pair *relayd = NULL;
  58
  59         /* Flag that the current stream if set for network streaming. */
  60         if (stream->net_seq_idx != -1) {
  61                 relayd = consumer_find_relayd(stream->net_seq_idx);
  62                 if (relayd == NULL) {
  63                         goto end;
  64                 }
  65         }
  66
  67         /* get the offset inside the fd to mmap */
  68         ret = ustctl_get_mmap_read_offset(stream->chan->handle,
  69                 stream->buf, &mmap_offset);
  70         if (ret != 0) {
  71                 errno = -ret;
  72                 PERROR("ustctl_get_mmap_read_offset");
  73                 written = ret;
  74                 goto end;
  75         }
  76
  77         /* Handle stream on the relayd if the output is on the network */
  78         if (relayd) {
  79                 if (stream->metadata_flag) {
  80                         /* Only lock if metadata since we use the control socket. */
  81                         pthread_mutex_lock(&relayd->ctrl_sock_mutex);
  82                 }
  83
  84                 ret = consumer_handle_stream_before_relayd(stream, len);
  85                 if (ret >= 0) {
  86                         outfd = ret;
  87
  88                         /* Write metadata stream id before payload */
  89                         if (stream->metadata_flag) {
  90                                 metadata_id = htobe64(stream->relayd_stream_id);
  91                                 do {
  92                                         ret = write(outfd, (void *) &metadata_id,
  93                                                         sizeof(stream->relayd_stream_id));
  94                                         if (ret < 0) {
  95                                                 PERROR("write metadata stream id");
  96                                                 written = ret;
  97                                                 goto end;
  98                                         }
  99                                 } while (errno == EINTR);
 100                                 DBG("Metadata stream id %zu written before data",
 101                                                 stream->relayd_stream_id);
 102                         }
 103                 }
 104                 /* Else, use the default set before which is the filesystem. */
 105         }
 106
 107         while (len > 0) {
 108                 ret = write(outfd, stream->mmap_base + mmap_offset, len);
 109                 if (ret < 0) {
 110                         if (errno == EINTR) {
 111                                 /* restart the interrupted system call */
 112                                 continue;
 113                         } else {
 114                                 PERROR("Error in file write");
 115                                 if (written == 0) {
 116                                         written = ret;
 117                                 }
 118                                 goto end;
 119                         }
 120                 } else if (ret > len) {
 121                         PERROR("ret %ld > len %lu", ret, len);
 122                         written += ret;
 123                         goto end;
 124                 } else {
 125                         len -= ret;
 126                         mmap_offset += ret;
 127                 }
 128                 DBG("UST mmap write() ret %ld (len %lu)", ret, len);
 129
 130                 /* This call is useless on a socket so better save a syscall. */
 131                 if (!relayd) {
 132                         /* This won't block, but will start writeout asynchronously */
 133                         lttng_sync_file_range(outfd, stream->out_fd_offset, ret,
 134                                         SYNC_FILE_RANGE_WRITE);
 135                         stream->out_fd_offset += ret;
 136                 }
 137                 written += ret;
 138         }
 139         lttng_consumer_sync_trace_file(stream, orig_offset);
 140
 141 end:
 142         if (relayd && stream->metadata_flag) {
 143                 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
 144         }
 145         return written;
 146 }
 147
 148 /*
 149  * Splice the data from the ring buffer to the tracefile.
 150  *
 151  * Returns the number of bytes spliced.
 152  */
 153 ssize_t lttng_ustconsumer_on_read_subbuffer_splice(
 154                 struct lttng_consumer_local_data *ctx,
 155                 struct lttng_consumer_stream *stream, unsigned long len)
 156 {
 157         return -ENOSYS;
 158 }
 159
 160 /*
 161  * Take a snapshot for a specific fd
 162  *
 163  * Returns 0 on success, < 0 on error
 164  */
 165 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_local_data *ctx,
 166                 struct lttng_consumer_stream *stream)
 167 {
 168         int ret = 0;
 169
 170         ret = ustctl_snapshot(stream->chan->handle, stream->buf);
 171         if (ret != 0) {
 172                 errno = -ret;
 173                 PERROR("Getting sub-buffer snapshot.");
 174         }
 175
 176         return ret;
 177 }
 178
 179 /*
 180  * Get the produced position
 181  *
 182  * Returns 0 on success, < 0 on error
 183  */
 184 int lttng_ustconsumer_get_produced_snapshot(
 185                 struct lttng_consumer_local_data *ctx,
 186                 struct lttng_consumer_stream *stream,
 187                 unsigned long *pos)
 188 {
 189         int ret;
 190
 191         ret = ustctl_snapshot_get_produced(stream->chan->handle,
 192                         stream->buf, pos);
 193         if (ret != 0) {
 194                 errno = -ret;
 195                 PERROR("kernctl_snapshot_get_produced");
 196         }
 197
 198         return ret;
 199 }
 200
 201 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
 202                 int sock, struct pollfd *consumer_sockpoll)
 203 {
 204         ssize_t ret;
 205         struct lttcomm_consumer_msg msg;
 206
 207         ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
 208         if (ret != sizeof(msg)) {
 209                 lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
 210                 return ret;
 211         }
 212         if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
 213                 return -ENOENT;
 214         }
 215
 216         switch (msg.cmd_type) {
 217         case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
 218         {
 219                 int fd;
 220                 struct consumer_relayd_sock_pair *relayd;
 221
 222                 DBG("UST Consumer adding relayd socket");
 223
 224                 /* Get relayd reference if exists. */
 225                 relayd = consumer_find_relayd(msg.u.relayd_sock.net_index);
 226                 if (relayd == NULL) {
 227                         /* Not found. Allocate one. */
 228                         relayd = consumer_allocate_relayd_sock_pair(
 229                                         msg.u.relayd_sock.net_index);
 230                         if (relayd == NULL) {
 231                                 lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
 232                                 goto end_nosignal;
 233                         }
 234                 }
 235
 236                 /* Poll on consumer socket. */
 237                 if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
 238                         return -EINTR;
 239                 }
 240
 241                 /* Get relayd socket from session daemon */
 242                 ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1);
 243                 if (ret != sizeof(fd)) {
 244                         lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
 245                         goto end_nosignal;
 246                 }
 247
 248                 /* Copy socket information and received FD */
 249                 switch (msg.u.relayd_sock.type) {
 250                 case LTTNG_STREAM_CONTROL:
 251                         /* Copy received lttcomm socket */
 252                         lttcomm_copy_sock(&relayd->control_sock, &msg.u.relayd_sock.sock);
 253                         ret = lttcomm_create_sock(&relayd->control_sock);
 254                         if (ret < 0) {
 255                                 goto end_nosignal;
 256                         }
 257
 258                         /* Close the created socket fd which is useless */
 259                         close(relayd->control_sock.fd);
 260
 261                         /* Assign new file descriptor */
 262                         relayd->control_sock.fd = fd;
 263                         break;
 264                 case LTTNG_STREAM_DATA:
 265                         /* Copy received lttcomm socket */
 266                         lttcomm_copy_sock(&relayd->data_sock, &msg.u.relayd_sock.sock);
 267                         ret = lttcomm_create_sock(&relayd->data_sock);
 268                         if (ret < 0) {
 269                                 goto end_nosignal;
 270                         }
 271
 272                         /* Close the created socket fd which is useless */
 273                         close(relayd->data_sock.fd);
 274
 275                         /* Assign new file descriptor */
 276                         relayd->data_sock.fd = fd;
 277                         break;
 278                 default:
 279                         ERR("Unknown relayd socket type");
 280                         goto end_nosignal;
 281                 }
 282
 283                 DBG("Consumer %s socket created successfully with net idx %d (fd: %d)",
 284                                 msg.u.relayd_sock.type == LTTNG_STREAM_CONTROL ? "control" : "data",
 285                                 relayd->net_seq_idx, fd);
 286
 287                 /*
 288                  * Add relayd socket pair to consumer data hashtable. If object already
 289                  * exists or on error, the function gracefully returns.
 290                  */
 291                 consumer_add_relayd(relayd);
 292
 293                 goto end_nosignal;
 294         }
 295         case LTTNG_CONSUMER_ADD_CHANNEL:
 296         {
 297                 struct lttng_consumer_channel *new_channel;
 298                 int fds[1];
 299                 size_t nb_fd = 1;
 300
 301                 /* block */
 302                 if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
 303                         return -EINTR;
 304                 }
 305                 ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd);
 306                 if (ret != sizeof(fds)) {
 307                         lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
 308                         return ret;
 309                 }
 310
 311                 DBG("consumer_add_channel %d", msg.u.channel.channel_key);
 312
 313                 new_channel = consumer_allocate_channel(msg.u.channel.channel_key,
 314                                 fds[0], -1,
 315                                 msg.u.channel.mmap_len,
 316                                 msg.u.channel.max_sb_size);
 317                 if (new_channel == NULL) {
 318                         lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
 319                         goto end_nosignal;
 320                 }
 321                 if (ctx->on_recv_channel != NULL) {
 322                         ret = ctx->on_recv_channel(new_channel);
 323                         if (ret == 0) {
 324                                 consumer_add_channel(new_channel);
 325                         } else if (ret < 0) {
 326                                 goto end_nosignal;
 327                         }
 328                 } else {
 329                         consumer_add_channel(new_channel);
 330                 }
 331                 goto end_nosignal;
 332         }
 333         case LTTNG_CONSUMER_ADD_STREAM:
 334         {
 335                 struct lttng_consumer_stream *new_stream;
 336                 int fds[2];
 337                 size_t nb_fd = 2;
 338                 struct consumer_relayd_sock_pair *relayd = NULL;
 339
 340                 /* block */
 341                 if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
 342                         return -EINTR;
 343                 }
 344                 ret = lttcomm_recv_fds_unix_sock(sock, fds, nb_fd);
 345                 if (ret != sizeof(fds)) {
 346                         lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD);
 347                         return ret;
 348                 }
 349
 350                 assert(msg.u.stream.output == LTTNG_EVENT_MMAP);
 351                 new_stream = consumer_allocate_stream(msg.u.channel.channel_key,
 352                                 msg.u.stream.stream_key,
 353                                 fds[0], fds[1],
 354                                 msg.u.stream.state,
 355                                 msg.u.stream.mmap_len,
 356                                 msg.u.stream.output,
 357                                 msg.u.stream.path_name,
 358                                 msg.u.stream.uid,
 359                                 msg.u.stream.gid,
 360                                 msg.u.stream.net_index,
 361                                 msg.u.stream.metadata_flag);
 362                 if (new_stream == NULL) {
 363                         lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR);
 364                         goto end;
 365                 }
 366
 367                 /* The stream is not metadata. Get relayd reference if exists. */
 368                 relayd = consumer_find_relayd(msg.u.stream.net_index);
 369                 if (relayd != NULL) {
 370                         pthread_mutex_lock(&relayd->ctrl_sock_mutex);
 371                         /* Add stream on the relayd */
 372                         ret = relayd_add_stream(&relayd->control_sock,
 373                                         msg.u.stream.name, msg.u.stream.path_name,
 374                                         &new_stream->relayd_stream_id);
 375                         pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
 376                         if (ret < 0) {
 377                                 goto end;
 378                         }
 379                 } else if (msg.u.stream.net_index != -1) {
 380                         ERR("Network sequence index %d unknown. Not adding stream.",
 381                                         msg.u.stream.net_index);
 382                         free(new_stream);
 383                         goto end;
 384                 }
 385
 386                 if (ctx->on_recv_stream != NULL) {
 387                         ret = ctx->on_recv_stream(new_stream);
 388                         if (ret == 0) {
 389                                 consumer_add_stream(new_stream);
 390                         } else if (ret < 0) {
 391                                 goto end;
 392                         }
 393                 } else {
 394                         consumer_add_stream(new_stream);
 395                 }
 396
 397                 DBG("UST consumer_add_stream %s (%d,%d) with relayd id %lu",
 398                                 msg.u.stream.path_name, fds[0], fds[1],
 399                                 new_stream->relayd_stream_id);
 400                 break;
 401         }
 402         case LTTNG_CONSUMER_UPDATE_STREAM:
 403         {
 404                 return -ENOSYS;
 405 #if 0
 406                 if (ctx->on_update_stream != NULL) {
 407                         ret = ctx->on_update_stream(msg.u.stream.stream_key, msg.u.stream.state);
 408                         if (ret == 0) {
 409                                 consumer_change_stream_state(msg.u.stream.stream_key, msg.u.stream.state);
 410                         } else if (ret < 0) {
 411                                 goto end;
 412                         }
 413                 } else {
 414                         consumer_change_stream_state(msg.u.stream.stream_key,
 415                                 msg.u.stream.state);
 416                 }
 417 #endif
 418                 break;
 419         }
 420         default:
 421                 break;
 422         }
 423 end:
 424         /*
 425          * Wake-up the other end by writing a null byte in the pipe
 426          * (non-blocking). Important note: Because writing into the
 427          * pipe is non-blocking (and therefore we allow dropping wakeup
 428          * data, as long as there is wakeup data present in the pipe
 429          * buffer to wake up the other end), the other end should
 430          * perform the following sequence for waiting:
 431          * 1) empty the pipe (reads).
 432          * 2) perform update operation.
 433          * 3) wait on the pipe (poll).
 434          */
 435         do {
 436                 ret = write(ctx->consumer_poll_pipe[1], "", 1);
 437         } while (ret == -1UL && errno == EINTR);
 438 end_nosignal:
 439         return 0;
 440 }
 441
 442 int lttng_ustconsumer_allocate_channel(struct lttng_consumer_channel *chan)
 443 {
 444         struct lttng_ust_object_data obj;
 445
 446         obj.handle = -1;
 447         obj.shm_fd = chan->shm_fd;
 448         obj.wait_fd = chan->wait_fd;
 449         obj.memory_map_size = chan->mmap_len;
 450         chan->handle = ustctl_map_channel(&obj);
 451         if (!chan->handle) {
 452                 return -ENOMEM;
 453         }
 454         chan->wait_fd_is_copy = 1;
 455         chan->shm_fd = -1;
 456
 457         return 0;
 458 }
 459
 460 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
 461 {
 462         ustctl_flush_buffer(stream->chan->handle, stream->buf, 0);
 463         stream->hangup_flush_done = 1;
 464 }
 465
 466 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
 467 {
 468         ustctl_unmap_channel(chan->handle);
 469 }
 470
 471 int lttng_ustconsumer_allocate_stream(struct lttng_consumer_stream *stream)
 472 {
 473         struct lttng_ust_object_data obj;
 474         int ret;
 475
 476         obj.handle = -1;
 477         obj.shm_fd = stream->shm_fd;
 478         obj.wait_fd = stream->wait_fd;
 479         obj.memory_map_size = stream->mmap_len;
 480         ret = ustctl_add_stream(stream->chan->handle, &obj);
 481         if (ret)
 482                 return ret;
 483         stream->buf = ustctl_open_stream_read(stream->chan->handle, stream->cpu);
 484         if (!stream->buf)
 485                 return -EBUSY;
 486         /* ustctl_open_stream_read has closed the shm fd. */
 487         stream->wait_fd_is_copy = 1;
 488         stream->shm_fd = -1;
 489
 490         stream->mmap_base = ustctl_get_mmap_base(stream->chan->handle, stream->buf);
 491         if (!stream->mmap_base) {
 492                 return -EINVAL;
 493         }
 494
 495         return 0;
 496 }
 497
 498 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
 499 {
 500         ustctl_close_stream_read(stream->chan->handle, stream->buf);
 501 }
 502
 503
 504 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
 505                 struct lttng_consumer_local_data *ctx)
 506 {
 507         unsigned long len;
 508         int err;
 509         long ret = 0;
 510         struct lttng_ust_shm_handle *handle;
 511         struct lttng_ust_lib_ring_buffer *buf;
 512         char dummy;
 513         ssize_t readlen;
 514
 515         DBG("In read_subbuffer (wait_fd: %d, stream key: %d)",
 516                 stream->wait_fd, stream->key);
 517
 518         /* We can consume the 1 byte written into the wait_fd by UST */
 519         if (!stream->hangup_flush_done) {
 520                 do {
 521                         readlen = read(stream->wait_fd, &dummy, 1);
 522                 } while (readlen == -1 && errno == EINTR);
 523                 if (readlen == -1) {
 524                         ret = readlen;
 525                         goto end;
 526                 }
 527         }
 528
 529         buf = stream->buf;
 530         handle = stream->chan->handle;
 531         /* Get the next subbuffer */
 532         err = ustctl_get_next_subbuf(handle, buf);
 533         if (err != 0) {
 534                 ret = -ret;     /* ustctl_get_next_subbuf returns negative, caller expect positive. */
 535                 /*
 536                  * This is a debug message even for single-threaded consumer,
 537                  * because poll() have more relaxed criterions than get subbuf,
 538                  * so get_subbuf may fail for short race windows where poll()
 539                  * would issue wakeups.
 540                  */
 541                 DBG("Reserving sub buffer failed (everything is normal, "
 542                                 "it is due to concurrency)");
 543                 goto end;
 544         }
 545         assert(stream->output == LTTNG_EVENT_MMAP);
 546         /* read the used subbuffer size */
 547         err = ustctl_get_padded_subbuf_size(handle, buf, &len);
 548         assert(err == 0);
 549         /* write the subbuffer to the tracefile */
 550         ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len);
 551         if (ret != len) {
 552                 /*
 553                  * display the error but continue processing to try
 554                  * to release the subbuffer
 555                  */
 556                 ERR("Error writing to tracefile");
 557         }
 558         err = ustctl_put_next_subbuf(handle, buf);
 559         assert(err == 0);
 560 end:
 561         return ret;
 562 }
 563
 564 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
 565 {
 566         int ret;
 567
 568         /* Opening the tracefile in write mode */
 569         if (stream->path_name != NULL && stream->net_seq_idx == -1) {
 570                 ret = run_as_open(stream->path_name,
 571                                 O_WRONLY|O_CREAT|O_TRUNC,
 572                                 S_IRWXU|S_IRWXG|S_IRWXO,
 573                                 stream->uid, stream->gid);
 574                 if (ret < 0) {
 575                         ERR("Opening %s", stream->path_name);
 576                         PERROR("open");
 577                         goto error;
 578                 }
 579                 stream->out_fd = ret;
 580         }
 581
 582         /* we return 0 to let the library handle the FD internally */
 583         return 0;
 584
 585 error:
 586         return ret;
 587 }