liblttng-ust-ctl/ustctl.c

   1 /*
   2  * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
   3  * Copyright (C) 2011-2013 - 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 as published by
   7  * the Free Software Foundation; version 2 of the License only.
   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 <string.h>
  21 #include <lttng/ust-ctl.h>
  22 #include <lttng/ust-abi.h>
  23 #include <lttng/ust-events.h>
  24 #include <sys/mman.h>
  25 #include <byteswap.h>
  26
  27 #include <usterr-signal-safe.h>
  28 #include <ust-comm.h>
  29 #include <helper.h>
  30
  31 #include "../libringbuffer/backend.h"
  32 #include "../libringbuffer/frontend.h"
  33 #include "../liblttng-ust/wait.h"
  34 #include "../liblttng-ust/lttng-rb-clients.h"
  35
  36 /*
  37  * Number of milliseconds to retry before failing metadata writes on
  38  * buffer full condition. (10 seconds)
  39  */
  40 #define LTTNG_METADATA_TIMEOUT_MSEC     10000
  41
  42 /*
  43  * Channel representation within consumer.
  44  */
  45 struct ustctl_consumer_channel {
  46         struct lttng_channel *chan;             /* lttng channel buffers */
  47
  48         /* initial attributes */
  49         struct ustctl_consumer_channel_attr attr;
  50         int wait_fd;                            /* monitor close() */
  51         int wakeup_fd;                          /* monitor close() */
  52 };
  53
  54 /*
  55  * Stream representation within consumer.
  56  */
  57 struct ustctl_consumer_stream {
  58         struct lttng_ust_shm_handle *handle;    /* shared-memory handle */
  59         struct lttng_ust_lib_ring_buffer *buf;
  60         struct ustctl_consumer_channel *chan;
  61         int shm_fd, wait_fd, wakeup_fd;
  62         int cpu;
  63         uint64_t memory_map_size;
  64 };
  65
  66 extern void lttng_ring_buffer_client_overwrite_init(void);
  67 extern void lttng_ring_buffer_client_overwrite_rt_init(void);
  68 extern void lttng_ring_buffer_client_discard_init(void);
  69 extern void lttng_ring_buffer_client_discard_rt_init(void);
  70 extern void lttng_ring_buffer_metadata_client_init(void);
  71 extern void lttng_ring_buffer_client_overwrite_exit(void);
  72 extern void lttng_ring_buffer_client_overwrite_rt_exit(void);
  73 extern void lttng_ring_buffer_client_discard_exit(void);
  74 extern void lttng_ring_buffer_client_discard_rt_exit(void);
  75 extern void lttng_ring_buffer_metadata_client_exit(void);
  76
  77 volatile enum ust_loglevel ust_loglevel;
  78
  79 int ustctl_release_handle(int sock, int handle)
  80 {
  81         struct ustcomm_ust_msg lum;
  82         struct ustcomm_ust_reply lur;
  83
  84         if (sock < 0 || handle < 0)
  85                 return 0;
  86         memset(&lum, 0, sizeof(lum));
  87         lum.handle = handle;
  88         lum.cmd = LTTNG_UST_RELEASE;
  89         return ustcomm_send_app_cmd(sock, &lum, &lur);
  90 }
  91
  92 /*
  93  * If sock is negative, it means we don't have to notify the other side
  94  * (e.g. application has already vanished).
  95  */
  96 int ustctl_release_object(int sock, struct lttng_ust_object_data *data)
  97 {
  98         int ret;
  99
 100         if (!data)
 101                 return -EINVAL;
 102
 103         switch (data->type) {
 104         case LTTNG_UST_OBJECT_TYPE_CHANNEL:
 105                 if (data->u.channel.wakeup_fd >= 0) {
 106                         ret = close(data->u.channel.wakeup_fd);
 107                         if (ret < 0) {
 108                                 ret = -errno;
 109                                 return ret;
 110                         }
 111                 }
 112                 free(data->u.channel.data);
 113                 break;
 114         case LTTNG_UST_OBJECT_TYPE_STREAM:
 115                 if (data->u.stream.shm_fd >= 0) {
 116                         ret = close(data->u.stream.shm_fd);
 117                         if (ret < 0) {
 118                                 ret = -errno;
 119                                 return ret;
 120                         }
 121                 }
 122                 if (data->u.stream.wakeup_fd >= 0) {
 123                         ret = close(data->u.stream.wakeup_fd);
 124                         if (ret < 0) {
 125                                 ret = -errno;
 126                                 return ret;
 127                         }
 128                 }
 129                 break;
 130         case LTTNG_UST_OBJECT_TYPE_EVENT:
 131         case LTTNG_UST_OBJECT_TYPE_CONTEXT:
 132                 break;
 133         default:
 134                 assert(0);
 135         }
 136         return ustctl_release_handle(sock, data->handle);
 137 }
 138
 139 /*
 140  * Send registration done packet to the application.
 141  */
 142 int ustctl_register_done(int sock)
 143 {
 144         struct ustcomm_ust_msg lum;
 145         struct ustcomm_ust_reply lur;
 146         int ret;
 147
 148         DBG("Sending register done command to %d", sock);
 149         memset(&lum, 0, sizeof(lum));
 150         lum.handle = LTTNG_UST_ROOT_HANDLE;
 151         lum.cmd = LTTNG_UST_REGISTER_DONE;
 152         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 153         if (ret)
 154                 return ret;
 155         return 0;
 156 }
 157
 158 /*
 159  * returns session handle.
 160  */
 161 int ustctl_create_session(int sock)
 162 {
 163         struct ustcomm_ust_msg lum;
 164         struct ustcomm_ust_reply lur;
 165         int ret, session_handle;
 166
 167         /* Create session */
 168         memset(&lum, 0, sizeof(lum));
 169         lum.handle = LTTNG_UST_ROOT_HANDLE;
 170         lum.cmd = LTTNG_UST_SESSION;
 171         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 172         if (ret)
 173                 return ret;
 174         session_handle = lur.ret_val;
 175         DBG("received session handle %u", session_handle);
 176         return session_handle;
 177 }
 178
 179 int ustctl_create_event(int sock, struct lttng_ust_event *ev,
 180                 struct lttng_ust_object_data *channel_data,
 181                 struct lttng_ust_object_data **_event_data)
 182 {
 183         struct ustcomm_ust_msg lum;
 184         struct ustcomm_ust_reply lur;
 185         struct lttng_ust_object_data *event_data;
 186         int ret;
 187
 188         if (!channel_data || !_event_data)
 189                 return -EINVAL;
 190
 191         event_data = zmalloc(sizeof(*event_data));
 192         if (!event_data)
 193                 return -ENOMEM;
 194         event_data->type = LTTNG_UST_OBJECT_TYPE_EVENT;
 195         memset(&lum, 0, sizeof(lum));
 196         lum.handle = channel_data->handle;
 197         lum.cmd = LTTNG_UST_EVENT;
 198         strncpy(lum.u.event.name, ev->name,
 199                 LTTNG_UST_SYM_NAME_LEN);
 200         lum.u.event.instrumentation = ev->instrumentation;
 201         lum.u.event.loglevel_type = ev->loglevel_type;
 202         lum.u.event.loglevel = ev->loglevel;
 203         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 204         if (ret) {
 205                 free(event_data);
 206                 return ret;
 207         }
 208         event_data->handle = lur.ret_val;
 209         DBG("received event handle %u", event_data->handle);
 210         *_event_data = event_data;
 211         return 0;
 212 }
 213
 214 int ustctl_add_context(int sock, struct lttng_ust_context *ctx,
 215                 struct lttng_ust_object_data *obj_data,
 216                 struct lttng_ust_object_data **_context_data)
 217 {
 218         struct ustcomm_ust_msg lum;
 219         struct ustcomm_ust_reply lur;
 220         struct lttng_ust_object_data *context_data;
 221         int ret;
 222
 223         if (!obj_data || !_context_data)
 224                 return -EINVAL;
 225
 226         context_data = zmalloc(sizeof(*context_data));
 227         if (!context_data)
 228                 return -ENOMEM;
 229         context_data->type = LTTNG_UST_OBJECT_TYPE_CONTEXT;
 230         memset(&lum, 0, sizeof(lum));
 231         lum.handle = obj_data->handle;
 232         lum.cmd = LTTNG_UST_CONTEXT;
 233         lum.u.context = *ctx;
 234         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 235         if (ret) {
 236                 free(context_data);
 237                 return ret;
 238         }
 239         context_data->handle = -1;
 240         DBG("Context created successfully");
 241         *_context_data = context_data;
 242         return ret;
 243 }
 244
 245 int ustctl_set_filter(int sock, struct lttng_ust_filter_bytecode *bytecode,
 246                 struct lttng_ust_object_data *obj_data)
 247 {
 248         struct ustcomm_ust_msg lum;
 249         struct ustcomm_ust_reply lur;
 250         int ret;
 251
 252         if (!obj_data)
 253                 return -EINVAL;
 254
 255         memset(&lum, 0, sizeof(lum));
 256         lum.handle = obj_data->handle;
 257         lum.cmd = LTTNG_UST_FILTER;
 258         lum.u.filter.data_size = bytecode->len;
 259         lum.u.filter.reloc_offset = bytecode->reloc_offset;
 260         lum.u.filter.seqnum = bytecode->seqnum;
 261
 262         ret = ustcomm_send_app_msg(sock, &lum);
 263         if (ret)
 264                 return ret;
 265         /* send var len bytecode */
 266         ret = ustcomm_send_unix_sock(sock, bytecode->data,
 267                                 bytecode->len);
 268         if (ret < 0) {
 269                 return ret;
 270         }
 271         if (ret != bytecode->len)
 272                 return -EINVAL;
 273         return ustcomm_recv_app_reply(sock, &lur, lum.handle, lum.cmd);
 274 }
 275
 276 int ustctl_set_exclusion(int sock, struct lttng_ust_event_exclusion *exclusion,
 277                 struct lttng_ust_object_data *obj_data)
 278 {
 279         struct ustcomm_ust_msg lum;
 280         struct ustcomm_ust_reply lur;
 281         int ret;
 282
 283         if (!obj_data) {
 284                 return -EINVAL;
 285         }
 286
 287         memset(&lum, 0, sizeof(lum));
 288         lum.handle = obj_data->handle;
 289         lum.cmd = LTTNG_UST_EXCLUSION;
 290         lum.u.exclusion.count = exclusion->count;
 291
 292         ret = ustcomm_send_app_msg(sock, &lum);
 293         if (ret) {
 294                 return ret;
 295         }
 296
 297         /* send var len exclusion names */
 298         ret = ustcomm_send_unix_sock(sock,
 299                         exclusion->names,
 300                         exclusion->count * LTTNG_UST_SYM_NAME_LEN);
 301         if (ret < 0) {
 302                 return ret;
 303         }
 304         if (ret != exclusion->count * LTTNG_UST_SYM_NAME_LEN) {
 305                 return -EINVAL;
 306         }
 307         return ustcomm_recv_app_reply(sock, &lur, lum.handle, lum.cmd);
 308 }
 309
 310 /* Enable event, channel and session ioctl */
 311 int ustctl_enable(int sock, struct lttng_ust_object_data *object)
 312 {
 313         struct ustcomm_ust_msg lum;
 314         struct ustcomm_ust_reply lur;
 315         int ret;
 316
 317         if (!object)
 318                 return -EINVAL;
 319
 320         memset(&lum, 0, sizeof(lum));
 321         lum.handle = object->handle;
 322         lum.cmd = LTTNG_UST_ENABLE;
 323         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 324         if (ret)
 325                 return ret;
 326         DBG("enabled handle %u", object->handle);
 327         return 0;
 328 }
 329
 330 /* Disable event, channel and session ioctl */
 331 int ustctl_disable(int sock, struct lttng_ust_object_data *object)
 332 {
 333         struct ustcomm_ust_msg lum;
 334         struct ustcomm_ust_reply lur;
 335         int ret;
 336
 337         if (!object)
 338                 return -EINVAL;
 339
 340         memset(&lum, 0, sizeof(lum));
 341         lum.handle = object->handle;
 342         lum.cmd = LTTNG_UST_DISABLE;
 343         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 344         if (ret)
 345                 return ret;
 346         DBG("disable handle %u", object->handle);
 347         return 0;
 348 }
 349
 350 int ustctl_start_session(int sock, int handle)
 351 {
 352         struct lttng_ust_object_data obj;
 353
 354         obj.handle = handle;
 355         return ustctl_enable(sock, &obj);
 356 }
 357
 358 int ustctl_stop_session(int sock, int handle)
 359 {
 360         struct lttng_ust_object_data obj;
 361
 362         obj.handle = handle;
 363         return ustctl_disable(sock, &obj);
 364 }
 365
 366 int ustctl_tracepoint_list(int sock)
 367 {
 368         struct ustcomm_ust_msg lum;
 369         struct ustcomm_ust_reply lur;
 370         int ret, tp_list_handle;
 371
 372         memset(&lum, 0, sizeof(lum));
 373         lum.handle = LTTNG_UST_ROOT_HANDLE;
 374         lum.cmd = LTTNG_UST_TRACEPOINT_LIST;
 375         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 376         if (ret)
 377                 return ret;
 378         tp_list_handle = lur.ret_val;
 379         DBG("received tracepoint list handle %u", tp_list_handle);
 380         return tp_list_handle;
 381 }
 382
 383 int ustctl_tracepoint_list_get(int sock, int tp_list_handle,
 384                 struct lttng_ust_tracepoint_iter *iter)
 385 {
 386         struct ustcomm_ust_msg lum;
 387         struct ustcomm_ust_reply lur;
 388         int ret;
 389
 390         if (!iter)
 391                 return -EINVAL;
 392
 393         memset(&lum, 0, sizeof(lum));
 394         lum.handle = tp_list_handle;
 395         lum.cmd = LTTNG_UST_TRACEPOINT_LIST_GET;
 396         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 397         if (ret)
 398                 return ret;
 399         DBG("received tracepoint list entry name %s loglevel %d",
 400                 lur.u.tracepoint.name,
 401                 lur.u.tracepoint.loglevel);
 402         memcpy(iter, &lur.u.tracepoint, sizeof(*iter));
 403         return 0;
 404 }
 405
 406 int ustctl_tracepoint_field_list(int sock)
 407 {
 408         struct ustcomm_ust_msg lum;
 409         struct ustcomm_ust_reply lur;
 410         int ret, tp_field_list_handle;
 411
 412         memset(&lum, 0, sizeof(lum));
 413         lum.handle = LTTNG_UST_ROOT_HANDLE;
 414         lum.cmd = LTTNG_UST_TRACEPOINT_FIELD_LIST;
 415         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 416         if (ret)
 417                 return ret;
 418         tp_field_list_handle = lur.ret_val;
 419         DBG("received tracepoint field list handle %u", tp_field_list_handle);
 420         return tp_field_list_handle;
 421 }
 422
 423 int ustctl_tracepoint_field_list_get(int sock, int tp_field_list_handle,
 424                 struct lttng_ust_field_iter *iter)
 425 {
 426         struct ustcomm_ust_msg lum;
 427         struct ustcomm_ust_reply lur;
 428         int ret;
 429         ssize_t len;
 430
 431         if (!iter)
 432                 return -EINVAL;
 433
 434         memset(&lum, 0, sizeof(lum));
 435         lum.handle = tp_field_list_handle;
 436         lum.cmd = LTTNG_UST_TRACEPOINT_FIELD_LIST_GET;
 437         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 438         if (ret)
 439                 return ret;
 440         len = ustcomm_recv_unix_sock(sock, iter, sizeof(*iter));
 441         if (len != sizeof(*iter)) {
 442                 return -EINVAL;
 443         }
 444         DBG("received tracepoint field list entry event_name %s event_loglevel %d field_name %s field_type %d",
 445                 iter->event_name,
 446                 iter->loglevel,
 447                 iter->field_name,
 448                 iter->type);
 449         return 0;
 450 }
 451
 452 int ustctl_tracer_version(int sock, struct lttng_ust_tracer_version *v)
 453 {
 454         struct ustcomm_ust_msg lum;
 455         struct ustcomm_ust_reply lur;
 456         int ret;
 457
 458         if (!v)
 459                 return -EINVAL;
 460
 461         memset(&lum, 0, sizeof(lum));
 462         lum.handle = LTTNG_UST_ROOT_HANDLE;
 463         lum.cmd = LTTNG_UST_TRACER_VERSION;
 464         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 465         if (ret)
 466                 return ret;
 467         memcpy(v, &lur.u.version, sizeof(*v));
 468         DBG("received tracer version");
 469         return 0;
 470 }
 471
 472 int ustctl_wait_quiescent(int sock)
 473 {
 474         struct ustcomm_ust_msg lum;
 475         struct ustcomm_ust_reply lur;
 476         int ret;
 477
 478         memset(&lum, 0, sizeof(lum));
 479         lum.handle = LTTNG_UST_ROOT_HANDLE;
 480         lum.cmd = LTTNG_UST_WAIT_QUIESCENT;
 481         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 482         if (ret)
 483                 return ret;
 484         DBG("waited for quiescent state");
 485         return 0;
 486 }
 487
 488 int ustctl_calibrate(int sock, struct lttng_ust_calibrate *calibrate)
 489 {
 490         if (!calibrate)
 491                 return -EINVAL;
 492
 493         return -ENOSYS;
 494 }
 495
 496 int ustctl_sock_flush_buffer(int sock, struct lttng_ust_object_data *object)
 497 {
 498         struct ustcomm_ust_msg lum;
 499         struct ustcomm_ust_reply lur;
 500         int ret;
 501
 502         if (!object)
 503                 return -EINVAL;
 504
 505         memset(&lum, 0, sizeof(lum));
 506         lum.handle = object->handle;
 507         lum.cmd = LTTNG_UST_FLUSH_BUFFER;
 508         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 509         if (ret)
 510                 return ret;
 511         DBG("flushed buffer handle %u", object->handle);
 512         return 0;
 513 }
 514
 515 static
 516 int ustctl_send_channel(int sock,
 517                 enum lttng_ust_chan_type type,
 518                 void *data,
 519                 uint64_t size,
 520                 int wakeup_fd,
 521                 int send_fd_only)
 522 {
 523         ssize_t len;
 524
 525         if (!send_fd_only) {
 526                 /* Send mmap size */
 527                 len = ustcomm_send_unix_sock(sock, &size, sizeof(size));
 528                 if (len != sizeof(size)) {
 529                         if (len < 0)
 530                                 return len;
 531                         else
 532                                 return -EIO;
 533                 }
 534
 535                 /* Send channel type */
 536                 len = ustcomm_send_unix_sock(sock, &type, sizeof(type));
 537                 if (len != sizeof(type)) {
 538                         if (len < 0)
 539                                 return len;
 540                         else
 541                                 return -EIO;
 542                 }
 543         }
 544
 545         /* Send channel data */
 546         len = ustcomm_send_unix_sock(sock, data, size);
 547         if (len != size) {
 548                 if (len < 0)
 549                         return len;
 550                 else
 551                         return -EIO;
 552         }
 553
 554         /* Send wakeup fd */
 555         len = ustcomm_send_fds_unix_sock(sock, &wakeup_fd, 1);
 556         if (len <= 0) {
 557                 if (len < 0)
 558                         return len;
 559                 else
 560                         return -EIO;
 561         }
 562         return 0;
 563 }
 564
 565 static
 566 int ustctl_send_stream(int sock,
 567                 uint32_t stream_nr,
 568                 uint64_t memory_map_size,
 569                 int shm_fd, int wakeup_fd,
 570                 int send_fd_only)
 571 {
 572         ssize_t len;
 573         int fds[2];
 574
 575         if (!send_fd_only) {
 576                 if (shm_fd < 0) {
 577                         /* finish iteration */
 578                         uint64_t v = -1;
 579
 580                         len = ustcomm_send_unix_sock(sock, &v, sizeof(v));
 581                         if (len != sizeof(v)) {
 582                                 if (len < 0)
 583                                         return len;
 584                                 else
 585                                         return -EIO;
 586                         }
 587                         return 0;
 588                 }
 589
 590                 /* Send mmap size */
 591                 len = ustcomm_send_unix_sock(sock, &memory_map_size,
 592                         sizeof(memory_map_size));
 593                 if (len != sizeof(memory_map_size)) {
 594                         if (len < 0)
 595                                 return len;
 596                         else
 597                                 return -EIO;
 598                 }
 599
 600                 /* Send stream nr */
 601                 len = ustcomm_send_unix_sock(sock, &stream_nr,
 602                         sizeof(stream_nr));
 603                 if (len != sizeof(stream_nr)) {
 604                         if (len < 0)
 605                                 return len;
 606                         else
 607                                 return -EIO;
 608                 }
 609         }
 610
 611         /* Send shm fd and wakeup fd */
 612         fds[0] = shm_fd;
 613         fds[1] = wakeup_fd;
 614         len = ustcomm_send_fds_unix_sock(sock, fds, 2);
 615         if (len <= 0) {
 616                 if (len < 0)
 617                         return len;
 618                 else
 619                         return -EIO;
 620         }
 621         return 0;
 622 }
 623
 624 int ustctl_recv_channel_from_consumer(int sock,
 625                 struct lttng_ust_object_data **_channel_data)
 626 {
 627         struct lttng_ust_object_data *channel_data;
 628         ssize_t len;
 629         int wakeup_fd;
 630         int ret;
 631
 632         channel_data = zmalloc(sizeof(*channel_data));
 633         if (!channel_data) {
 634                 ret = -ENOMEM;
 635                 goto error_alloc;
 636         }
 637         channel_data->type = LTTNG_UST_OBJECT_TYPE_CHANNEL;
 638         channel_data->handle = -1;
 639
 640         /* recv mmap size */
 641         len = ustcomm_recv_unix_sock(sock, &channel_data->size,
 642                         sizeof(channel_data->size));
 643         if (len != sizeof(channel_data->size)) {
 644                 if (len < 0)
 645                         ret = len;
 646                 else
 647                         ret = -EINVAL;
 648                 goto error;
 649         }
 650
 651         /* recv channel type */
 652         len = ustcomm_recv_unix_sock(sock, &channel_data->u.channel.type,
 653                         sizeof(channel_data->u.channel.type));
 654         if (len != sizeof(channel_data->u.channel.type)) {
 655                 if (len < 0)
 656                         ret = len;
 657                 else
 658                         ret = -EINVAL;
 659                 goto error;
 660         }
 661
 662         /* recv channel data */
 663         channel_data->u.channel.data = zmalloc(channel_data->size);
 664         if (!channel_data->u.channel.data) {
 665                 ret = -ENOMEM;
 666                 goto error;
 667         }
 668         len = ustcomm_recv_unix_sock(sock, channel_data->u.channel.data,
 669                         channel_data->size);
 670         if (len != channel_data->size) {
 671                 if (len < 0)
 672                         ret = len;
 673                 else
 674                         ret = -EINVAL;
 675                 goto error_recv_data;
 676         }
 677         /* recv wakeup fd */
 678         len = ustcomm_recv_fds_unix_sock(sock, &wakeup_fd, 1);
 679         if (len <= 0) {
 680                 if (len < 0) {
 681                         ret = len;
 682                         goto error_recv_data;
 683                 } else {
 684                         ret = -EIO;
 685                         goto error_recv_data;
 686                 }
 687         }
 688         channel_data->u.channel.wakeup_fd = wakeup_fd;
 689         *_channel_data = channel_data;
 690         return 0;
 691
 692 error_recv_data:
 693         free(channel_data->u.channel.data);
 694 error:
 695         free(channel_data);
 696 error_alloc:
 697         return ret;
 698 }
 699
 700 int ustctl_recv_stream_from_consumer(int sock,
 701                 struct lttng_ust_object_data **_stream_data)
 702 {
 703         struct lttng_ust_object_data *stream_data;
 704         ssize_t len;
 705         int ret;
 706         int fds[2];
 707
 708         stream_data = zmalloc(sizeof(*stream_data));
 709         if (!stream_data) {
 710                 ret = -ENOMEM;
 711                 goto error_alloc;
 712         }
 713
 714         stream_data->type = LTTNG_UST_OBJECT_TYPE_STREAM;
 715         stream_data->handle = -1;
 716
 717         /* recv mmap size */
 718         len = ustcomm_recv_unix_sock(sock, &stream_data->size,
 719                         sizeof(stream_data->size));
 720         if (len != sizeof(stream_data->size)) {
 721                 if (len < 0)
 722                         ret = len;
 723                 else
 724                         ret = -EINVAL;
 725                 goto error;
 726         }
 727         if (stream_data->size == -1) {
 728                 ret = -LTTNG_UST_ERR_NOENT;
 729                 goto error;
 730         }
 731
 732         /* recv stream nr */
 733         len = ustcomm_recv_unix_sock(sock, &stream_data->u.stream.stream_nr,
 734                         sizeof(stream_data->u.stream.stream_nr));
 735         if (len != sizeof(stream_data->u.stream.stream_nr)) {
 736                 if (len < 0)
 737                         ret = len;
 738                 else
 739                         ret = -EINVAL;
 740                 goto error;
 741         }
 742
 743         /* recv shm fd and wakeup fd */
 744         len = ustcomm_recv_fds_unix_sock(sock, fds, 2);
 745         if (len <= 0) {
 746                 if (len < 0) {
 747                         ret = len;
 748                         goto error;
 749                 } else {
 750                         ret = -EIO;
 751                         goto error;
 752                 }
 753         }
 754         stream_data->u.stream.shm_fd = fds[0];
 755         stream_data->u.stream.wakeup_fd = fds[1];
 756         *_stream_data = stream_data;
 757         return 0;
 758
 759 error:
 760         free(stream_data);
 761 error_alloc:
 762         return ret;
 763 }
 764
 765 int ustctl_send_channel_to_ust(int sock, int session_handle,
 766                 struct lttng_ust_object_data *channel_data)
 767 {
 768         struct ustcomm_ust_msg lum;
 769         struct ustcomm_ust_reply lur;
 770         int ret;
 771
 772         if (!channel_data)
 773                 return -EINVAL;
 774
 775         memset(&lum, 0, sizeof(lum));
 776         lum.handle = session_handle;
 777         lum.cmd = LTTNG_UST_CHANNEL;
 778         lum.u.channel.len = channel_data->size;
 779         lum.u.channel.type = channel_data->u.channel.type;
 780         ret = ustcomm_send_app_msg(sock, &lum);
 781         if (ret)
 782                 return ret;
 783
 784         ret = ustctl_send_channel(sock,
 785                         channel_data->u.channel.type,
 786                         channel_data->u.channel.data,
 787                         channel_data->size,
 788                         channel_data->u.channel.wakeup_fd,
 789                         1);
 790         if (ret)
 791                 return ret;
 792         ret = ustcomm_recv_app_reply(sock, &lur, lum.handle, lum.cmd);
 793         if (!ret) {
 794                 channel_data->handle = lur.ret_val;
 795         }
 796         return ret;
 797 }
 798
 799 int ustctl_send_stream_to_ust(int sock,
 800                 struct lttng_ust_object_data *channel_data,
 801                 struct lttng_ust_object_data *stream_data)
 802 {
 803         struct ustcomm_ust_msg lum;
 804         struct ustcomm_ust_reply lur;
 805         int ret;
 806
 807         memset(&lum, 0, sizeof(lum));
 808         lum.handle = channel_data->handle;
 809         lum.cmd = LTTNG_UST_STREAM;
 810         lum.u.stream.len = stream_data->size;
 811         lum.u.stream.stream_nr = stream_data->u.stream.stream_nr;
 812         ret = ustcomm_send_app_msg(sock, &lum);
 813         if (ret)
 814                 return ret;
 815
 816         assert(stream_data);
 817         assert(stream_data->type == LTTNG_UST_OBJECT_TYPE_STREAM);
 818
 819         ret = ustctl_send_stream(sock,
 820                         stream_data->u.stream.stream_nr,
 821                         stream_data->size,
 822                         stream_data->u.stream.shm_fd,
 823                         stream_data->u.stream.wakeup_fd, 1);
 824         if (ret)
 825                 return ret;
 826         return ustcomm_recv_app_reply(sock, &lur, lum.handle, lum.cmd);
 827 }
 828
 829 int ustctl_duplicate_ust_object_data(struct lttng_ust_object_data **dest,
 830                 struct lttng_ust_object_data *src)
 831 {
 832         struct lttng_ust_object_data *obj;
 833         int ret;
 834
 835         if (src->handle != -1) {
 836                 ret = -EINVAL;
 837                 goto error;
 838         }
 839
 840         obj = zmalloc(sizeof(*obj));
 841         if (!obj) {
 842                 ret = -ENOMEM;
 843                 goto error;
 844         }
 845
 846         obj->type = src->type;
 847         obj->handle = src->handle;
 848         obj->size = src->size;
 849
 850         switch (obj->type) {
 851         case LTTNG_UST_OBJECT_TYPE_CHANNEL:
 852         {
 853                 obj->u.channel.type = src->u.channel.type;
 854                 if (src->u.channel.wakeup_fd >= 0) {
 855                         obj->u.channel.wakeup_fd =
 856                                 dup(src->u.channel.wakeup_fd);
 857                         if (obj->u.channel.wakeup_fd < 0) {
 858                                 ret = errno;
 859                                 goto chan_error_wakeup_fd;
 860                         }
 861                 } else {
 862                         obj->u.channel.wakeup_fd =
 863                                 src->u.channel.wakeup_fd;
 864                 }
 865                 obj->u.channel.data = zmalloc(obj->size);
 866                 if (!obj->u.channel.data) {
 867                         ret = -ENOMEM;
 868                         goto chan_error_alloc;
 869                 }
 870                 memcpy(obj->u.channel.data, src->u.channel.data, obj->size);
 871                 break;
 872
 873         chan_error_alloc:
 874                 if (src->u.channel.wakeup_fd >= 0) {
 875                         int closeret;
 876
 877                         closeret = close(obj->u.channel.wakeup_fd);
 878                         if (closeret) {
 879                                 PERROR("close");
 880                         }
 881                 }
 882         chan_error_wakeup_fd:
 883                 goto error_type;
 884
 885         }
 886
 887         case LTTNG_UST_OBJECT_TYPE_STREAM:
 888         {
 889                 obj->u.stream.stream_nr = src->u.stream.stream_nr;
 890                 if (src->u.stream.wakeup_fd >= 0) {
 891                         obj->u.stream.wakeup_fd =
 892                                 dup(src->u.stream.wakeup_fd);
 893                         if (obj->u.stream.wakeup_fd < 0) {
 894                                 ret = errno;
 895                                 goto stream_error_wakeup_fd;
 896                         }
 897                 } else {
 898                         obj->u.stream.wakeup_fd =
 899                                 src->u.stream.wakeup_fd;
 900                 }
 901
 902                 if (src->u.stream.shm_fd >= 0) {
 903                         obj->u.stream.shm_fd =
 904                                 dup(src->u.stream.shm_fd);
 905                         if (obj->u.stream.shm_fd < 0) {
 906                                 ret = errno;
 907                                 goto stream_error_shm_fd;
 908                         }
 909                 } else {
 910                         obj->u.stream.shm_fd =
 911                                 src->u.stream.shm_fd;
 912                 }
 913                 break;
 914
 915         stream_error_shm_fd:
 916                 if (src->u.stream.wakeup_fd >= 0) {
 917                         int closeret;
 918
 919                         closeret = close(obj->u.stream.wakeup_fd);
 920                         if (closeret) {
 921                                 PERROR("close");
 922                         }
 923                 }
 924         stream_error_wakeup_fd:
 925                 goto error_type;
 926         }
 927
 928         default:
 929                 ret = -EINVAL;
 930                 goto error_type;
 931         }
 932
 933         *dest = obj;
 934         return 0;
 935
 936 error_type:
 937         free(obj);
 938 error:
 939         return ret;
 940 }
 941
 942
 943 /* Buffer operations */
 944
 945 struct ustctl_consumer_channel *
 946         ustctl_create_channel(struct ustctl_consumer_channel_attr *attr)
 947 {
 948         struct ustctl_consumer_channel *chan;
 949         const char *transport_name;
 950         struct lttng_transport *transport;
 951
 952         switch (attr->type) {
 953         case LTTNG_UST_CHAN_PER_CPU:
 954                 if (attr->output == LTTNG_UST_MMAP) {
 955                         if (attr->overwrite) {
 956                                 if (attr->read_timer_interval == 0) {
 957                                         transport_name = "relay-overwrite-mmap";
 958                                 } else {
 959                                         transport_name = "relay-overwrite-rt-mmap";
 960                                 }
 961                         } else {
 962                                 if (attr->read_timer_interval == 0) {
 963                                         transport_name = "relay-discard-mmap";
 964                                 } else {
 965                                         transport_name = "relay-discard-rt-mmap";
 966                                 }
 967                         }
 968                 } else {
 969                         return NULL;
 970                 }
 971                 break;
 972         case LTTNG_UST_CHAN_METADATA:
 973                 if (attr->output == LTTNG_UST_MMAP)
 974                         transport_name = "relay-metadata-mmap";
 975                 else
 976                         return NULL;
 977                 break;
 978         default:
 979                 transport_name = "<unknown>";
 980                 return NULL;
 981         }
 982
 983         transport = lttng_transport_find(transport_name);
 984         if (!transport) {
 985                 DBG("LTTng transport %s not found\n",
 986                         transport_name);
 987                 return NULL;
 988         }
 989
 990         chan = zmalloc(sizeof(*chan));
 991         if (!chan)
 992                 return NULL;
 993
 994         chan->chan = transport->ops.channel_create(transport_name, NULL,
 995                         attr->subbuf_size, attr->num_subbuf,
 996                         attr->switch_timer_interval,
 997                         attr->read_timer_interval,
 998                         attr->uuid, attr->chan_id);
 999         if (!chan->chan) {
1000                 goto chan_error;
1001         }
1002         chan->chan->ops = &transport->ops;
1003         memcpy(&chan->attr, attr, sizeof(chan->attr));
1004         chan->wait_fd = ustctl_channel_get_wait_fd(chan);
1005         chan->wakeup_fd = ustctl_channel_get_wakeup_fd(chan);
1006         return chan;
1007
1008 chan_error:
1009         free(chan);
1010         return NULL;
1011 }
1012
1013 void ustctl_destroy_channel(struct ustctl_consumer_channel *chan)
1014 {
1015         (void) ustctl_channel_close_wait_fd(chan);
1016         (void) ustctl_channel_close_wakeup_fd(chan);
1017         chan->chan->ops->channel_destroy(chan->chan);
1018         free(chan);
1019 }
1020
1021 int ustctl_send_channel_to_sessiond(int sock,
1022                 struct ustctl_consumer_channel *channel)
1023 {
1024         struct shm_object_table *table;
1025
1026         table = channel->chan->handle->table;
1027         if (table->size <= 0)
1028                 return -EINVAL;
1029         return ustctl_send_channel(sock,
1030                         channel->attr.type,
1031                         table->objects[0].memory_map,
1032                         table->objects[0].memory_map_size,
1033                         channel->wakeup_fd,
1034                         0);
1035 }
1036
1037 int ustctl_send_stream_to_sessiond(int sock,
1038                 struct ustctl_consumer_stream *stream)
1039 {
1040         if (!stream)
1041                 return ustctl_send_stream(sock, -1U, -1U, -1, -1, 0);
1042
1043         return ustctl_send_stream(sock,
1044                         stream->cpu,
1045                         stream->memory_map_size,
1046                         stream->shm_fd, stream->wakeup_fd,
1047                         0);
1048 }
1049
1050 int ustctl_write_metadata_to_channel(
1051                 struct ustctl_consumer_channel *channel,
1052                 const char *metadata_str,       /* NOT null-terminated */
1053                 size_t len)                     /* metadata length */
1054 {
1055         struct lttng_ust_lib_ring_buffer_ctx ctx;
1056         struct lttng_channel *chan = channel->chan;
1057         const char *str = metadata_str;
1058         int ret = 0, waitret;
1059         size_t reserve_len, pos;
1060
1061         for (pos = 0; pos < len; pos += reserve_len) {
1062                 reserve_len = min_t(size_t,
1063                                 chan->ops->packet_avail_size(chan->chan, chan->handle),
1064                                 len - pos);
1065                 lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
1066                                          sizeof(char), -1, chan->handle);
1067                 /*
1068                  * We don't care about metadata buffer's records lost
1069                  * count, because we always retry here. Report error if
1070                  * we need to bail out after timeout or being
1071                  * interrupted.
1072                  */
1073                 waitret = wait_cond_interruptible_timeout(
1074                         ({
1075                                 ret = chan->ops->event_reserve(&ctx, 0);
1076                                 ret != -ENOBUFS || !ret;
1077                         }),
1078                         LTTNG_METADATA_TIMEOUT_MSEC);
1079                 if (waitret == -ETIMEDOUT || waitret == -EINTR || ret) {
1080                         DBG("LTTng: Failure to write metadata to buffers (%s)\n",
1081                                 waitret == -EINTR ? "interrupted" :
1082                                         (ret == -ENOBUFS ? "timeout" : "I/O error"));
1083                         if (waitret == -EINTR)
1084                                 ret = waitret;
1085                         goto end;
1086                 }
1087                 chan->ops->event_write(&ctx, &str[pos], reserve_len);
1088                 chan->ops->event_commit(&ctx);
1089         }
1090 end:
1091         return ret;
1092 }
1093
1094 /*
1095  * Write at most one packet in the channel.
1096  * Returns the number of bytes written on success, < 0 on error.
1097  */
1098 ssize_t ustctl_write_one_packet_to_channel(
1099                 struct ustctl_consumer_channel *channel,
1100                 const char *metadata_str,       /* NOT null-terminated */
1101                 size_t len)                     /* metadata length */
1102 {
1103         struct lttng_ust_lib_ring_buffer_ctx ctx;
1104         struct lttng_channel *chan = channel->chan;
1105         const char *str = metadata_str;
1106         ssize_t reserve_len;
1107         int ret;
1108
1109         reserve_len = min_t(ssize_t,
1110                         chan->ops->packet_avail_size(chan->chan, chan->handle),
1111                         len);
1112         lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
1113                         sizeof(char), -1, chan->handle);
1114         ret = chan->ops->event_reserve(&ctx, 0);
1115         if (ret != 0) {
1116                 DBG("LTTng: event reservation failed");
1117                 assert(ret < 0);
1118                 reserve_len = ret;
1119                 goto end;
1120         }
1121         chan->ops->event_write(&ctx, str, reserve_len);
1122         chan->ops->event_commit(&ctx);
1123
1124 end:
1125         return reserve_len;
1126 }
1127
1128 int ustctl_channel_close_wait_fd(struct ustctl_consumer_channel *consumer_chan)
1129 {
1130         struct channel *chan;
1131         int ret;
1132
1133         chan = consumer_chan->chan->chan;
1134         ret = ring_buffer_channel_close_wait_fd(&chan->backend.config,
1135                         chan, chan->handle);
1136         if (!ret)
1137                 consumer_chan->wait_fd = -1;
1138         return ret;
1139 }
1140
1141 int ustctl_channel_close_wakeup_fd(struct ustctl_consumer_channel *consumer_chan)
1142 {
1143         struct channel *chan;
1144         int ret;
1145
1146         chan = consumer_chan->chan->chan;
1147         ret = ring_buffer_channel_close_wakeup_fd(&chan->backend.config,
1148                         chan, chan->handle);
1149         if (!ret)
1150                 consumer_chan->wakeup_fd = -1;
1151         return ret;
1152 }
1153
1154 int ustctl_stream_close_wait_fd(struct ustctl_consumer_stream *stream)
1155 {
1156         struct channel *chan;
1157
1158         chan = stream->chan->chan->chan;
1159         return ring_buffer_stream_close_wait_fd(&chan->backend.config,
1160                         chan, stream->handle, stream->cpu);
1161 }
1162
1163 int ustctl_stream_close_wakeup_fd(struct ustctl_consumer_stream *stream)
1164 {
1165         struct channel *chan;
1166
1167         chan = stream->chan->chan->chan;
1168         return ring_buffer_stream_close_wakeup_fd(&chan->backend.config,
1169                         chan, stream->handle, stream->cpu);
1170 }
1171
1172 struct ustctl_consumer_stream *
1173         ustctl_create_stream(struct ustctl_consumer_channel *channel,
1174                         int cpu)
1175 {
1176         struct ustctl_consumer_stream *stream;
1177         struct lttng_ust_shm_handle *handle;
1178         struct channel *chan;
1179         int shm_fd, wait_fd, wakeup_fd;
1180         uint64_t memory_map_size;
1181         struct lttng_ust_lib_ring_buffer *buf;
1182         int ret;
1183
1184         if (!channel)
1185                 return NULL;
1186         handle = channel->chan->handle;
1187         if (!handle)
1188                 return NULL;
1189
1190         chan = channel->chan->chan;
1191         buf = channel_get_ring_buffer(&chan->backend.config,
1192                 chan, cpu, handle, &shm_fd, &wait_fd,
1193                 &wakeup_fd, &memory_map_size);
1194         if (!buf)
1195                 return NULL;
1196         ret = lib_ring_buffer_open_read(buf, handle);
1197         if (ret)
1198                 return NULL;
1199
1200         stream = zmalloc(sizeof(*stream));
1201         if (!stream)
1202                 goto alloc_error;
1203         stream->handle = handle;
1204         stream->buf = buf;
1205         stream->chan = channel;
1206         stream->shm_fd = shm_fd;
1207         stream->wait_fd = wait_fd;
1208         stream->wakeup_fd = wakeup_fd;
1209         stream->memory_map_size = memory_map_size;
1210         stream->cpu = cpu;
1211         return stream;
1212
1213 alloc_error:
1214         return NULL;
1215 }
1216
1217 void ustctl_destroy_stream(struct ustctl_consumer_stream *stream)
1218 {
1219         struct lttng_ust_lib_ring_buffer *buf;
1220         struct ustctl_consumer_channel *consumer_chan;
1221
1222         assert(stream);
1223         buf = stream->buf;
1224         consumer_chan = stream->chan;
1225         (void) ustctl_stream_close_wait_fd(stream);
1226         (void) ustctl_stream_close_wakeup_fd(stream);
1227         lib_ring_buffer_release_read(buf, consumer_chan->chan->handle);
1228         free(stream);
1229 }
1230
1231 int ustctl_channel_get_wait_fd(struct ustctl_consumer_channel *chan)
1232 {
1233         if (!chan)
1234                 return -EINVAL;
1235         return shm_get_wait_fd(chan->chan->handle,
1236                 &chan->chan->handle->chan._ref);
1237 }
1238
1239 int ustctl_channel_get_wakeup_fd(struct ustctl_consumer_channel *chan)
1240 {
1241         if (!chan)
1242                 return -EINVAL;
1243         return shm_get_wakeup_fd(chan->chan->handle,
1244                 &chan->chan->handle->chan._ref);
1245 }
1246
1247 int ustctl_stream_get_wait_fd(struct ustctl_consumer_stream *stream)
1248 {
1249         struct lttng_ust_lib_ring_buffer *buf;
1250         struct ustctl_consumer_channel *consumer_chan;
1251
1252         if (!stream)
1253                 return -EINVAL;
1254         buf = stream->buf;
1255         consumer_chan = stream->chan;
1256         return shm_get_wait_fd(consumer_chan->chan->handle, &buf->self._ref);
1257 }
1258
1259 int ustctl_stream_get_wakeup_fd(struct ustctl_consumer_stream *stream)
1260 {
1261         struct lttng_ust_lib_ring_buffer *buf;
1262         struct ustctl_consumer_channel *consumer_chan;
1263
1264         if (!stream)
1265                 return -EINVAL;
1266         buf = stream->buf;
1267         consumer_chan = stream->chan;
1268         return shm_get_wakeup_fd(consumer_chan->chan->handle, &buf->self._ref);
1269 }
1270
1271 /* For mmap mode, readable without "get" operation */
1272
1273 void *ustctl_get_mmap_base(struct ustctl_consumer_stream *stream)
1274 {
1275         struct lttng_ust_lib_ring_buffer *buf;
1276         struct ustctl_consumer_channel *consumer_chan;
1277
1278         if (!stream)
1279                 return NULL;
1280         buf = stream->buf;
1281         consumer_chan = stream->chan;
1282         return shmp(consumer_chan->chan->handle, buf->backend.memory_map);
1283 }
1284
1285 /* returns the length to mmap. */
1286 int ustctl_get_mmap_len(struct ustctl_consumer_stream *stream,
1287                 unsigned long *len)
1288 {
1289         struct ustctl_consumer_channel *consumer_chan;
1290         unsigned long mmap_buf_len;
1291         struct channel *chan;
1292
1293         if (!stream)
1294                 return -EINVAL;
1295         consumer_chan = stream->chan;
1296         chan = consumer_chan->chan->chan;
1297         if (chan->backend.config.output != RING_BUFFER_MMAP)
1298                 return -EINVAL;
1299         mmap_buf_len = chan->backend.buf_size;
1300         if (chan->backend.extra_reader_sb)
1301                 mmap_buf_len += chan->backend.subbuf_size;
1302         if (mmap_buf_len > INT_MAX)
1303                 return -EFBIG;
1304         *len = mmap_buf_len;
1305         return 0;
1306 }
1307
1308 /* returns the maximum size for sub-buffers. */
1309 int ustctl_get_max_subbuf_size(struct ustctl_consumer_stream *stream,
1310                 unsigned long *len)
1311 {
1312         struct ustctl_consumer_channel *consumer_chan;
1313         struct channel *chan;
1314
1315         if (!stream)
1316                 return -EINVAL;
1317         consumer_chan = stream->chan;
1318         chan = consumer_chan->chan->chan;
1319         *len = chan->backend.subbuf_size;
1320         return 0;
1321 }
1322
1323 /*
1324  * For mmap mode, operate on the current packet (between get/put or
1325  * get_next/put_next).
1326  */
1327
1328 /* returns the offset of the subbuffer belonging to the mmap reader. */
1329 int ustctl_get_mmap_read_offset(struct ustctl_consumer_stream *stream,
1330                 unsigned long *off)
1331 {
1332         struct channel *chan;
1333         unsigned long sb_bindex;
1334         struct lttng_ust_lib_ring_buffer *buf;
1335         struct ustctl_consumer_channel *consumer_chan;
1336
1337         if (!stream)
1338                 return -EINVAL;
1339         buf = stream->buf;
1340         consumer_chan = stream->chan;
1341         chan = consumer_chan->chan->chan;
1342         if (chan->backend.config.output != RING_BUFFER_MMAP)
1343                 return -EINVAL;
1344         sb_bindex = subbuffer_id_get_index(&chan->backend.config,
1345                                         buf->backend.buf_rsb.id);
1346         *off = shmp(consumer_chan->chan->handle,
1347                 shmp_index(consumer_chan->chan->handle, buf->backend.array, sb_bindex)->shmp)->mmap_offset;
1348         return 0;
1349 }
1350
1351 /* returns the size of the current sub-buffer, without padding (for mmap). */
1352 int ustctl_get_subbuf_size(struct ustctl_consumer_stream *stream,
1353                 unsigned long *len)
1354 {
1355         struct ustctl_consumer_channel *consumer_chan;
1356         struct channel *chan;
1357         struct lttng_ust_lib_ring_buffer *buf;
1358
1359         if (!stream)
1360                 return -EINVAL;
1361
1362         buf = stream->buf;
1363         consumer_chan = stream->chan;
1364         chan = consumer_chan->chan->chan;
1365         *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf,
1366                 consumer_chan->chan->handle);
1367         return 0;
1368 }
1369
1370 /* returns the size of the current sub-buffer, without padding (for mmap). */
1371 int ustctl_get_padded_subbuf_size(struct ustctl_consumer_stream *stream,
1372                 unsigned long *len)
1373 {
1374         struct ustctl_consumer_channel *consumer_chan;
1375         struct channel *chan;
1376         struct lttng_ust_lib_ring_buffer *buf;
1377
1378         if (!stream)
1379                 return -EINVAL;
1380         buf = stream->buf;
1381         consumer_chan = stream->chan;
1382         chan = consumer_chan->chan->chan;
1383         *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf,
1384                 consumer_chan->chan->handle);
1385         *len = PAGE_ALIGN(*len);
1386         return 0;
1387 }
1388
1389 /* Get exclusive read access to the next sub-buffer that can be read. */
1390 int ustctl_get_next_subbuf(struct ustctl_consumer_stream *stream)
1391 {
1392         struct lttng_ust_lib_ring_buffer *buf;
1393         struct ustctl_consumer_channel *consumer_chan;
1394
1395         if (!stream)
1396                 return -EINVAL;
1397         buf = stream->buf;
1398         consumer_chan = stream->chan;
1399         return lib_ring_buffer_get_next_subbuf(buf,
1400                         consumer_chan->chan->handle);
1401 }
1402
1403
1404 /* Release exclusive sub-buffer access, move consumer forward. */
1405 int ustctl_put_next_subbuf(struct ustctl_consumer_stream *stream)
1406 {
1407         struct lttng_ust_lib_ring_buffer *buf;
1408         struct ustctl_consumer_channel *consumer_chan;
1409
1410         if (!stream)
1411                 return -EINVAL;
1412         buf = stream->buf;
1413         consumer_chan = stream->chan;
1414         lib_ring_buffer_put_next_subbuf(buf, consumer_chan->chan->handle);
1415         return 0;
1416 }
1417
1418 /* snapshot */
1419
1420 /* Get a snapshot of the current ring buffer producer and consumer positions */
1421 int ustctl_snapshot(struct ustctl_consumer_stream *stream)
1422 {
1423         struct lttng_ust_lib_ring_buffer *buf;
1424         struct ustctl_consumer_channel *consumer_chan;
1425
1426         if (!stream)
1427                 return -EINVAL;
1428         buf = stream->buf;
1429         consumer_chan = stream->chan;
1430         return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
1431                         &buf->prod_snapshot, consumer_chan->chan->handle);
1432 }
1433
1434 /* Get the consumer position (iteration start) */
1435 int ustctl_snapshot_get_consumed(struct ustctl_consumer_stream *stream,
1436                 unsigned long *pos)
1437 {
1438         struct lttng_ust_lib_ring_buffer *buf;
1439
1440         if (!stream)
1441                 return -EINVAL;
1442         buf = stream->buf;
1443         *pos = buf->cons_snapshot;
1444         return 0;
1445 }
1446
1447 /* Get the producer position (iteration end) */
1448 int ustctl_snapshot_get_produced(struct ustctl_consumer_stream *stream,
1449                 unsigned long *pos)
1450 {
1451         struct lttng_ust_lib_ring_buffer *buf;
1452
1453         if (!stream)
1454                 return -EINVAL;
1455         buf = stream->buf;
1456         *pos = buf->prod_snapshot;
1457         return 0;
1458 }
1459
1460 /* Get exclusive read access to the specified sub-buffer position */
1461 int ustctl_get_subbuf(struct ustctl_consumer_stream *stream,
1462                 unsigned long *pos)
1463 {
1464         struct lttng_ust_lib_ring_buffer *buf;
1465         struct ustctl_consumer_channel *consumer_chan;
1466
1467         if (!stream)
1468                 return -EINVAL;
1469         buf = stream->buf;
1470         consumer_chan = stream->chan;
1471         return lib_ring_buffer_get_subbuf(buf, *pos,
1472                         consumer_chan->chan->handle);
1473 }
1474
1475 /* Release exclusive sub-buffer access */
1476 int ustctl_put_subbuf(struct ustctl_consumer_stream *stream)
1477 {
1478         struct lttng_ust_lib_ring_buffer *buf;
1479         struct ustctl_consumer_channel *consumer_chan;
1480
1481         if (!stream)
1482                 return -EINVAL;
1483         buf = stream->buf;
1484         consumer_chan = stream->chan;
1485         lib_ring_buffer_put_subbuf(buf, consumer_chan->chan->handle);
1486         return 0;
1487 }
1488
1489 void ustctl_flush_buffer(struct ustctl_consumer_stream *stream,
1490                 int producer_active)
1491 {
1492         struct lttng_ust_lib_ring_buffer *buf;
1493         struct ustctl_consumer_channel *consumer_chan;
1494
1495         assert(stream);
1496         buf = stream->buf;
1497         consumer_chan = stream->chan;
1498         lib_ring_buffer_switch_slow(buf,
1499                 producer_active ? SWITCH_ACTIVE : SWITCH_FLUSH,
1500                 consumer_chan->chan->handle);
1501 }
1502
1503 static
1504 struct lttng_ust_client_lib_ring_buffer_client_cb *get_client_cb(
1505                 struct lttng_ust_lib_ring_buffer *buf,
1506                 struct lttng_ust_shm_handle *handle)
1507 {
1508         struct channel *chan;
1509         const struct lttng_ust_lib_ring_buffer_config *config;
1510         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1511
1512         chan = shmp(handle, buf->backend.chan);
1513         config = &chan->backend.config;
1514         if (!config->cb_ptr)
1515                 return NULL;
1516         client_cb = caa_container_of(config->cb_ptr,
1517                         struct lttng_ust_client_lib_ring_buffer_client_cb,
1518                         parent);
1519         return client_cb;
1520 }
1521
1522 int ustctl_get_timestamp_begin(struct ustctl_consumer_stream *stream,
1523                 uint64_t *timestamp_begin)
1524 {
1525         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1526         struct lttng_ust_lib_ring_buffer *buf;
1527         struct lttng_ust_shm_handle *handle;
1528
1529         if (!stream || !timestamp_begin)
1530                 return -EINVAL;
1531         buf = stream->buf;
1532         handle = stream->chan->chan->handle;
1533         client_cb = get_client_cb(buf, handle);
1534         if (!client_cb)
1535                 return -ENOSYS;
1536         return client_cb->timestamp_begin(buf, handle, timestamp_begin);
1537 }
1538
1539 int ustctl_get_timestamp_end(struct ustctl_consumer_stream *stream,
1540         uint64_t *timestamp_end)
1541 {
1542         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1543         struct lttng_ust_lib_ring_buffer *buf;
1544         struct lttng_ust_shm_handle *handle;
1545
1546         if (!stream || !timestamp_end)
1547                 return -EINVAL;
1548         buf = stream->buf;
1549         handle = stream->chan->chan->handle;
1550         client_cb = get_client_cb(buf, handle);
1551         if (!client_cb)
1552                 return -ENOSYS;
1553         return client_cb->timestamp_end(buf, handle, timestamp_end);
1554 }
1555
1556 int ustctl_get_events_discarded(struct ustctl_consumer_stream *stream,
1557         uint64_t *events_discarded)
1558 {
1559         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1560         struct lttng_ust_lib_ring_buffer *buf;
1561         struct lttng_ust_shm_handle *handle;
1562
1563         if (!stream || !events_discarded)
1564                 return -EINVAL;
1565         buf = stream->buf;
1566         handle = stream->chan->chan->handle;
1567         client_cb = get_client_cb(buf, handle);
1568         if (!client_cb)
1569                 return -ENOSYS;
1570         return client_cb->events_discarded(buf, handle, events_discarded);
1571 }
1572
1573 int ustctl_get_content_size(struct ustctl_consumer_stream *stream,
1574         uint64_t *content_size)
1575 {
1576         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1577         struct lttng_ust_lib_ring_buffer *buf;
1578         struct lttng_ust_shm_handle *handle;
1579
1580         if (!stream || !content_size)
1581                 return -EINVAL;
1582         buf = stream->buf;
1583         handle = stream->chan->chan->handle;
1584         client_cb = get_client_cb(buf, handle);
1585         if (!client_cb)
1586                 return -ENOSYS;
1587         return client_cb->content_size(buf, handle, content_size);
1588 }
1589
1590 int ustctl_get_packet_size(struct ustctl_consumer_stream *stream,
1591         uint64_t *packet_size)
1592 {
1593         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1594         struct lttng_ust_lib_ring_buffer *buf;
1595         struct lttng_ust_shm_handle *handle;
1596
1597         if (!stream || !packet_size)
1598                 return -EINVAL;
1599         buf = stream->buf;
1600         handle = stream->chan->chan->handle;
1601         client_cb = get_client_cb(buf, handle);
1602         if (!client_cb)
1603                 return -ENOSYS;
1604         return client_cb->packet_size(buf, handle, packet_size);
1605 }
1606
1607 int ustctl_get_stream_id(struct ustctl_consumer_stream *stream,
1608                 uint64_t *stream_id)
1609 {
1610         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1611         struct lttng_ust_lib_ring_buffer *buf;
1612         struct lttng_ust_shm_handle *handle;
1613
1614         if (!stream || !stream_id)
1615                 return -EINVAL;
1616         buf = stream->buf;
1617         handle = stream->chan->chan->handle;
1618         client_cb = get_client_cb(buf, handle);
1619         if (!client_cb)
1620                 return -ENOSYS;
1621         return client_cb->stream_id(buf, handle, stream_id);
1622 }
1623
1624 int ustctl_get_current_timestamp(struct ustctl_consumer_stream *stream,
1625                 uint64_t *ts)
1626 {
1627         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1628         struct lttng_ust_lib_ring_buffer *buf;
1629         struct lttng_ust_shm_handle *handle;
1630
1631         if (!stream || !ts)
1632                 return -EINVAL;
1633         buf = stream->buf;
1634         handle = stream->chan->chan->handle;
1635         client_cb = get_client_cb(buf, handle);
1636         if (!client_cb || !client_cb->current_timestamp)
1637                 return -ENOSYS;
1638         return client_cb->current_timestamp(buf, handle, ts);
1639 }
1640
1641 /*
1642  * Returns 0 on success, negative error value on error.
1643  */
1644 int ustctl_recv_reg_msg(int sock,
1645         enum ustctl_socket_type *type,
1646         uint32_t *major,
1647         uint32_t *minor,
1648         uint32_t *pid,
1649         uint32_t *ppid,
1650         uint32_t *uid,
1651         uint32_t *gid,
1652         uint32_t *bits_per_long,
1653         uint32_t *uint8_t_alignment,
1654         uint32_t *uint16_t_alignment,
1655         uint32_t *uint32_t_alignment,
1656         uint32_t *uint64_t_alignment,
1657         uint32_t *long_alignment,
1658         int *byte_order,
1659         char *name)
1660 {
1661         ssize_t len;
1662         struct ustctl_reg_msg reg_msg;
1663
1664         len = ustcomm_recv_unix_sock(sock, &reg_msg, sizeof(reg_msg));
1665         if (len > 0 && len != sizeof(reg_msg))
1666                 return -EIO;
1667         if (len == 0)
1668                 return -EPIPE;
1669         if (len < 0)
1670                 return len;
1671
1672         if (reg_msg.magic == LTTNG_UST_COMM_MAGIC) {
1673                 *byte_order = BYTE_ORDER == BIG_ENDIAN ?
1674                                 BIG_ENDIAN : LITTLE_ENDIAN;
1675         } else if (reg_msg.magic == bswap_32(LTTNG_UST_COMM_MAGIC)) {
1676                 *byte_order = BYTE_ORDER == BIG_ENDIAN ?
1677                                 LITTLE_ENDIAN : BIG_ENDIAN;
1678         } else {
1679                 return -LTTNG_UST_ERR_INVAL_MAGIC;
1680         }
1681         switch (reg_msg.socket_type) {
1682         case 0: *type = USTCTL_SOCKET_CMD;
1683                 break;
1684         case 1: *type = USTCTL_SOCKET_NOTIFY;
1685                 break;
1686         default:
1687                 return -LTTNG_UST_ERR_INVAL_SOCKET_TYPE;
1688         }
1689         *major = reg_msg.major;
1690         *minor = reg_msg.minor;
1691         *pid = reg_msg.pid;
1692         *ppid = reg_msg.ppid;
1693         *uid = reg_msg.uid;
1694         *gid = reg_msg.gid;
1695         *bits_per_long = reg_msg.bits_per_long;
1696         *uint8_t_alignment = reg_msg.uint8_t_alignment;
1697         *uint16_t_alignment = reg_msg.uint16_t_alignment;
1698         *uint32_t_alignment = reg_msg.uint32_t_alignment;
1699         *uint64_t_alignment = reg_msg.uint64_t_alignment;
1700         *long_alignment = reg_msg.long_alignment;
1701         memcpy(name, reg_msg.name, LTTNG_UST_ABI_PROCNAME_LEN);
1702         if (reg_msg.major != LTTNG_UST_ABI_MAJOR_VERSION) {
1703                 return -LTTNG_UST_ERR_UNSUP_MAJOR;
1704         }
1705
1706         return 0;
1707 }
1708
1709 int ustctl_recv_notify(int sock, enum ustctl_notify_cmd *notify_cmd)
1710 {
1711         struct ustcomm_notify_hdr header;
1712         ssize_t len;
1713
1714         len = ustcomm_recv_unix_sock(sock, &header, sizeof(header));
1715         if (len > 0 && len != sizeof(header))
1716                 return -EIO;
1717         if (len == 0)
1718                 return -EPIPE;
1719         if (len < 0)
1720                 return len;
1721         switch (header.notify_cmd) {
1722         case 0:
1723                 *notify_cmd = USTCTL_NOTIFY_CMD_EVENT;
1724                 break;
1725         case 1:
1726                 *notify_cmd = USTCTL_NOTIFY_CMD_CHANNEL;
1727                 break;
1728         default:
1729                 return -EINVAL;
1730         }
1731         return 0;
1732 }
1733
1734 /*
1735  * Returns 0 on success, negative error value on error.
1736  */
1737 int ustctl_recv_register_event(int sock,
1738         int *session_objd,
1739         int *channel_objd,
1740         char *event_name,
1741         int *loglevel,
1742         char **signature,
1743         size_t *nr_fields,
1744         struct ustctl_field **fields,
1745         char **model_emf_uri)
1746 {
1747         ssize_t len;
1748         struct ustcomm_notify_event_msg msg;
1749         size_t signature_len, fields_len, model_emf_uri_len;
1750         char *a_sign = NULL, *a_model_emf_uri = NULL;
1751         struct ustctl_field *a_fields = NULL;
1752
1753         len = ustcomm_recv_unix_sock(sock, &msg, sizeof(msg));
1754         if (len > 0 && len != sizeof(msg))
1755                 return -EIO;
1756         if (len == 0)
1757                 return -EPIPE;
1758         if (len < 0)
1759                 return len;
1760
1761         *session_objd = msg.session_objd;
1762         *channel_objd = msg.channel_objd;
1763         strncpy(event_name, msg.event_name, LTTNG_UST_SYM_NAME_LEN);
1764         event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1765         *loglevel = msg.loglevel;
1766         signature_len = msg.signature_len;
1767         fields_len = msg.fields_len;
1768
1769         if (fields_len % sizeof(*a_fields) != 0) {
1770                 return -EINVAL;
1771         }
1772
1773         model_emf_uri_len = msg.model_emf_uri_len;
1774
1775         /* recv signature. contains at least \0. */
1776         a_sign = zmalloc(signature_len);
1777         if (!a_sign)
1778                 return -ENOMEM;
1779         len = ustcomm_recv_unix_sock(sock, a_sign, signature_len);
1780         if (len > 0 && len != signature_len) {
1781                 len = -EIO;
1782                 goto signature_error;
1783         }
1784         if (len == 0) {
1785                 len = -EPIPE;
1786                 goto signature_error;
1787         }
1788         if (len < 0) {
1789                 goto signature_error;
1790         }
1791         /* Enforce end of string */
1792         a_sign[signature_len - 1] = '\0';
1793
1794         /* recv fields */
1795         if (fields_len) {
1796                 a_fields = zmalloc(fields_len);
1797                 if (!a_fields) {
1798                         len = -ENOMEM;
1799                         goto signature_error;
1800                 }
1801                 len = ustcomm_recv_unix_sock(sock, a_fields, fields_len);
1802                 if (len > 0 && len != fields_len) {
1803                         len = -EIO;
1804                         goto fields_error;
1805                 }
1806                 if (len == 0) {
1807                         len = -EPIPE;
1808                         goto fields_error;
1809                 }
1810                 if (len < 0) {
1811                         goto fields_error;
1812                 }
1813         }
1814
1815         if (model_emf_uri_len) {
1816                 /* recv model_emf_uri_len */
1817                 a_model_emf_uri = zmalloc(model_emf_uri_len);
1818                 if (!a_model_emf_uri) {
1819                         len = -ENOMEM;
1820                         goto fields_error;
1821                 }
1822                 len = ustcomm_recv_unix_sock(sock, a_model_emf_uri,
1823                                 model_emf_uri_len);
1824                 if (len > 0 && len != model_emf_uri_len) {
1825                         len = -EIO;
1826                         goto model_error;
1827                 }
1828                 if (len == 0) {
1829                         len = -EPIPE;
1830                         goto model_error;
1831                 }
1832                 if (len < 0) {
1833                         goto model_error;
1834                 }
1835                 /* Enforce end of string */
1836                 a_model_emf_uri[model_emf_uri_len - 1] = '\0';
1837         }
1838
1839         *signature = a_sign;
1840         *nr_fields = fields_len / sizeof(*a_fields);
1841         *fields = a_fields;
1842         *model_emf_uri = a_model_emf_uri;
1843
1844         return 0;
1845
1846 model_error:
1847         free(a_model_emf_uri);
1848 fields_error:
1849         free(a_fields);
1850 signature_error:
1851         free(a_sign);
1852         return len;
1853 }
1854
1855 /*
1856  * Returns 0 on success, negative error value on error.
1857  */
1858 int ustctl_reply_register_event(int sock,
1859         uint32_t id,
1860         int ret_code)
1861 {
1862         ssize_t len;
1863         struct {
1864                 struct ustcomm_notify_hdr header;
1865                 struct ustcomm_notify_event_reply r;
1866         } reply;
1867
1868         memset(&reply, 0, sizeof(reply));
1869         reply.header.notify_cmd = USTCTL_NOTIFY_CMD_EVENT;
1870         reply.r.ret_code = ret_code;
1871         reply.r.event_id = id;
1872         len = ustcomm_send_unix_sock(sock, &reply, sizeof(reply));
1873         if (len > 0 && len != sizeof(reply))
1874                 return -EIO;
1875         if (len < 0)
1876                 return len;
1877         return 0;
1878 }
1879
1880 /*
1881  * Returns 0 on success, negative UST or system error value on error.
1882  */
1883 int ustctl_recv_register_channel(int sock,
1884         int *session_objd,              /* session descriptor (output) */
1885         int *channel_objd,              /* channel descriptor (output) */
1886         size_t *nr_fields,
1887         struct ustctl_field **fields)
1888 {
1889         ssize_t len;
1890         struct ustcomm_notify_channel_msg msg;
1891         size_t fields_len;
1892         struct ustctl_field *a_fields;
1893
1894         len = ustcomm_recv_unix_sock(sock, &msg, sizeof(msg));
1895         if (len > 0 && len != sizeof(msg))
1896                 return -EIO;
1897         if (len == 0)
1898                 return -EPIPE;
1899         if (len < 0)
1900                 return len;
1901
1902         *session_objd = msg.session_objd;
1903         *channel_objd = msg.channel_objd;
1904         fields_len = msg.ctx_fields_len;
1905
1906         if (fields_len % sizeof(*a_fields) != 0) {
1907                 return -EINVAL;
1908         }
1909
1910         /* recv fields */
1911         if (fields_len) {
1912                 a_fields = zmalloc(fields_len);
1913                 if (!a_fields) {
1914                         len = -ENOMEM;
1915                         goto alloc_error;
1916                 }
1917                 len = ustcomm_recv_unix_sock(sock, a_fields, fields_len);
1918                 if (len > 0 && len != fields_len) {
1919                         len = -EIO;
1920                         goto fields_error;
1921                 }
1922                 if (len == 0) {
1923                         len = -EPIPE;
1924                         goto fields_error;
1925                 }
1926                 if (len < 0) {
1927                         goto fields_error;
1928                 }
1929                 *fields = a_fields;
1930         } else {
1931                 *fields = NULL;
1932         }
1933         *nr_fields = fields_len / sizeof(*a_fields);
1934         return 0;
1935
1936 fields_error:
1937         free(a_fields);
1938 alloc_error:
1939         return len;
1940 }
1941
1942 /*
1943  * Returns 0 on success, negative error value on error.
1944  */
1945 int ustctl_reply_register_channel(int sock,
1946         uint32_t chan_id,
1947         enum ustctl_channel_header header_type,
1948         int ret_code)
1949 {
1950         ssize_t len;
1951         struct {
1952                 struct ustcomm_notify_hdr header;
1953                 struct ustcomm_notify_channel_reply r;
1954         } reply;
1955
1956         memset(&reply, 0, sizeof(reply));
1957         reply.header.notify_cmd = USTCTL_NOTIFY_CMD_CHANNEL;
1958         reply.r.ret_code = ret_code;
1959         reply.r.chan_id = chan_id;
1960         switch (header_type) {
1961         case USTCTL_CHANNEL_HEADER_COMPACT:
1962                 reply.r.header_type = 1;
1963                 break;
1964         case USTCTL_CHANNEL_HEADER_LARGE:
1965                 reply.r.header_type = 2;
1966                 break;
1967         default:
1968                 reply.r.header_type = 0;
1969                 break;
1970         }
1971         len = ustcomm_send_unix_sock(sock, &reply, sizeof(reply));
1972         if (len > 0 && len != sizeof(reply))
1973                 return -EIO;
1974         if (len < 0)
1975                 return len;
1976         return 0;
1977 }
1978
1979 static __attribute__((constructor))
1980 void ustctl_init(void)
1981 {
1982         init_usterr();
1983         lttng_ring_buffer_metadata_client_init();
1984         lttng_ring_buffer_client_overwrite_init();
1985         lttng_ring_buffer_client_overwrite_rt_init();
1986         lttng_ring_buffer_client_discard_init();
1987         lttng_ring_buffer_client_discard_rt_init();
1988         lib_ringbuffer_signal_init();
1989 }
1990
1991 static __attribute__((destructor))
1992 void ustctl_exit(void)
1993 {
1994         lttng_ring_buffer_client_discard_rt_exit();
1995         lttng_ring_buffer_client_discard_exit();
1996         lttng_ring_buffer_client_overwrite_rt_exit();
1997         lttng_ring_buffer_client_overwrite_exit();
1998         lttng_ring_buffer_metadata_client_exit();
1999 }