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