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 #include "../liblttng-ust/clock.h"
  36
  37 /*
  38  * Number of milliseconds to retry before failing metadata writes on
  39  * buffer full condition. (10 seconds)
  40  */
  41 #define LTTNG_METADATA_TIMEOUT_MSEC     10000
  42
  43 /*
  44  * Channel representation within consumer.
  45  */
  46 struct ustctl_consumer_channel {
  47         struct lttng_channel *chan;             /* lttng channel buffers */
  48
  49         /* initial attributes */
  50         struct ustctl_consumer_channel_attr attr;
  51         int wait_fd;                            /* monitor close() */
  52         int wakeup_fd;                          /* monitor close() */
  53 };
  54
  55 /*
  56  * Stream representation within consumer.
  57  */
  58 struct ustctl_consumer_stream {
  59         struct lttng_ust_shm_handle *handle;    /* shared-memory handle */
  60         struct lttng_ust_lib_ring_buffer *buf;
  61         struct ustctl_consumer_channel *chan;
  62         int shm_fd, wait_fd, wakeup_fd;
  63         int cpu;
  64         uint64_t memory_map_size;
  65 };
  66
  67 extern void lttng_ring_buffer_client_overwrite_init(void);
  68 extern void lttng_ring_buffer_client_overwrite_rt_init(void);
  69 extern void lttng_ring_buffer_client_discard_init(void);
  70 extern void lttng_ring_buffer_client_discard_rt_init(void);
  71 extern void lttng_ring_buffer_metadata_client_init(void);
  72 extern void lttng_ring_buffer_client_overwrite_exit(void);
  73 extern void lttng_ring_buffer_client_overwrite_rt_exit(void);
  74 extern void lttng_ring_buffer_client_discard_exit(void);
  75 extern void lttng_ring_buffer_client_discard_rt_exit(void);
  76 extern void lttng_ring_buffer_metadata_client_exit(void);
  77
  78 volatile enum ust_loglevel ust_loglevel;
  79
  80 int ustctl_release_handle(int sock, int handle)
  81 {
  82         struct ustcomm_ust_msg lum;
  83         struct ustcomm_ust_reply lur;
  84
  85         if (sock < 0 || handle < 0)
  86                 return 0;
  87         memset(&lum, 0, sizeof(lum));
  88         lum.handle = handle;
  89         lum.cmd = LTTNG_UST_RELEASE;
  90         return ustcomm_send_app_cmd(sock, &lum, &lur);
  91 }
  92
  93 /*
  94  * If sock is negative, it means we don't have to notify the other side
  95  * (e.g. application has already vanished).
  96  */
  97 int ustctl_release_object(int sock, struct lttng_ust_object_data *data)
  98 {
  99         int ret;
 100
 101         if (!data)
 102                 return -EINVAL;
 103
 104         switch (data->type) {
 105         case LTTNG_UST_OBJECT_TYPE_CHANNEL:
 106                 if (data->u.channel.wakeup_fd >= 0) {
 107                         ret = close(data->u.channel.wakeup_fd);
 108                         if (ret < 0) {
 109                                 ret = -errno;
 110                                 return ret;
 111                         }
 112                 }
 113                 free(data->u.channel.data);
 114                 break;
 115         case LTTNG_UST_OBJECT_TYPE_STREAM:
 116                 if (data->u.stream.shm_fd >= 0) {
 117                         ret = close(data->u.stream.shm_fd);
 118                         if (ret < 0) {
 119                                 ret = -errno;
 120                                 return ret;
 121                         }
 122                 }
 123                 if (data->u.stream.wakeup_fd >= 0) {
 124                         ret = close(data->u.stream.wakeup_fd);
 125                         if (ret < 0) {
 126                                 ret = -errno;
 127                                 return ret;
 128                         }
 129                 }
 130                 break;
 131         case LTTNG_UST_OBJECT_TYPE_EVENT:
 132         case LTTNG_UST_OBJECT_TYPE_CONTEXT:
 133                 break;
 134         default:
 135                 assert(0);
 136         }
 137         return ustctl_release_handle(sock, data->handle);
 138 }
 139
 140 /*
 141  * Send registration done packet to the application.
 142  */
 143 int ustctl_register_done(int sock)
 144 {
 145         struct ustcomm_ust_msg lum;
 146         struct ustcomm_ust_reply lur;
 147         int ret;
 148
 149         DBG("Sending register done command to %d", sock);
 150         memset(&lum, 0, sizeof(lum));
 151         lum.handle = LTTNG_UST_ROOT_HANDLE;
 152         lum.cmd = LTTNG_UST_REGISTER_DONE;
 153         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 154         if (ret)
 155                 return ret;
 156         return 0;
 157 }
 158
 159 /*
 160  * returns session handle.
 161  */
 162 int ustctl_create_session(int sock)
 163 {
 164         struct ustcomm_ust_msg lum;
 165         struct ustcomm_ust_reply lur;
 166         int ret, session_handle;
 167
 168         /* Create session */
 169         memset(&lum, 0, sizeof(lum));
 170         lum.handle = LTTNG_UST_ROOT_HANDLE;
 171         lum.cmd = LTTNG_UST_SESSION;
 172         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 173         if (ret)
 174                 return ret;
 175         session_handle = lur.ret_val;
 176         DBG("received session handle %u", session_handle);
 177         return session_handle;
 178 }
 179
 180 int ustctl_create_event(int sock, struct lttng_ust_event *ev,
 181                 struct lttng_ust_object_data *channel_data,
 182                 struct lttng_ust_object_data **_event_data)
 183 {
 184         struct ustcomm_ust_msg lum;
 185         struct ustcomm_ust_reply lur;
 186         struct lttng_ust_object_data *event_data;
 187         int ret;
 188
 189         if (!channel_data || !_event_data)
 190                 return -EINVAL;
 191
 192         event_data = zmalloc(sizeof(*event_data));
 193         if (!event_data)
 194                 return -ENOMEM;
 195         event_data->type = LTTNG_UST_OBJECT_TYPE_EVENT;
 196         memset(&lum, 0, sizeof(lum));
 197         lum.handle = channel_data->handle;
 198         lum.cmd = LTTNG_UST_EVENT;
 199         strncpy(lum.u.event.name, ev->name,
 200                 LTTNG_UST_SYM_NAME_LEN);
 201         lum.u.event.instrumentation = ev->instrumentation;
 202         lum.u.event.loglevel_type = ev->loglevel_type;
 203         lum.u.event.loglevel = ev->loglevel;
 204         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 205         if (ret) {
 206                 free(event_data);
 207                 return ret;
 208         }
 209         event_data->handle = lur.ret_val;
 210         DBG("received event handle %u", event_data->handle);
 211         *_event_data = event_data;
 212         return 0;
 213 }
 214
 215 int ustctl_add_context(int sock, struct lttng_ust_context *ctx,
 216                 struct lttng_ust_object_data *obj_data,
 217                 struct lttng_ust_object_data **_context_data)
 218 {
 219         struct ustcomm_ust_msg lum;
 220         struct ustcomm_ust_reply lur;
 221         struct lttng_ust_object_data *context_data;
 222         int ret;
 223
 224         if (!obj_data || !_context_data)
 225                 return -EINVAL;
 226
 227         context_data = zmalloc(sizeof(*context_data));
 228         if (!context_data)
 229                 return -ENOMEM;
 230         context_data->type = LTTNG_UST_OBJECT_TYPE_CONTEXT;
 231         memset(&lum, 0, sizeof(lum));
 232         lum.handle = obj_data->handle;
 233         lum.cmd = LTTNG_UST_CONTEXT;
 234         lum.u.context = *ctx;
 235         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 236         if (ret) {
 237                 free(context_data);
 238                 return ret;
 239         }
 240         context_data->handle = -1;
 241         DBG("Context created successfully");
 242         *_context_data = context_data;
 243         return ret;
 244 }
 245
 246 int ustctl_set_filter(int sock, struct lttng_ust_filter_bytecode *bytecode,
 247                 struct lttng_ust_object_data *obj_data)
 248 {
 249         struct ustcomm_ust_msg lum;
 250         struct ustcomm_ust_reply lur;
 251         int ret;
 252
 253         if (!obj_data)
 254                 return -EINVAL;
 255
 256         memset(&lum, 0, sizeof(lum));
 257         lum.handle = obj_data->handle;
 258         lum.cmd = LTTNG_UST_FILTER;
 259         lum.u.filter.data_size = bytecode->len;
 260         lum.u.filter.reloc_offset = bytecode->reloc_offset;
 261         lum.u.filter.seqnum = bytecode->seqnum;
 262
 263         ret = ustcomm_send_app_msg(sock, &lum);
 264         if (ret)
 265                 return ret;
 266         /* send var len bytecode */
 267         ret = ustcomm_send_unix_sock(sock, bytecode->data,
 268                                 bytecode->len);
 269         if (ret < 0) {
 270                 return ret;
 271         }
 272         if (ret != bytecode->len)
 273                 return -EINVAL;
 274         return ustcomm_recv_app_reply(sock, &lur, lum.handle, lum.cmd);
 275 }
 276
 277 int ustctl_set_exclusion(int sock, struct lttng_ust_event_exclusion *exclusion,
 278                 struct lttng_ust_object_data *obj_data)
 279 {
 280         struct ustcomm_ust_msg lum;
 281         struct ustcomm_ust_reply lur;
 282         int ret;
 283
 284         if (!obj_data) {
 285                 return -EINVAL;
 286         }
 287
 288         memset(&lum, 0, sizeof(lum));
 289         lum.handle = obj_data->handle;
 290         lum.cmd = LTTNG_UST_EXCLUSION;
 291         lum.u.exclusion.count = exclusion->count;
 292
 293         ret = ustcomm_send_app_msg(sock, &lum);
 294         if (ret) {
 295                 return ret;
 296         }
 297
 298         /* send var len exclusion names */
 299         ret = ustcomm_send_unix_sock(sock,
 300                         exclusion->names,
 301                         exclusion->count * LTTNG_UST_SYM_NAME_LEN);
 302         if (ret < 0) {
 303                 return ret;
 304         }
 305         if (ret != exclusion->count * LTTNG_UST_SYM_NAME_LEN) {
 306                 return -EINVAL;
 307         }
 308         return ustcomm_recv_app_reply(sock, &lur, lum.handle, lum.cmd);
 309 }
 310
 311 /* Enable event, channel and session ioctl */
 312 int ustctl_enable(int sock, struct lttng_ust_object_data *object)
 313 {
 314         struct ustcomm_ust_msg lum;
 315         struct ustcomm_ust_reply lur;
 316         int ret;
 317
 318         if (!object)
 319                 return -EINVAL;
 320
 321         memset(&lum, 0, sizeof(lum));
 322         lum.handle = object->handle;
 323         lum.cmd = LTTNG_UST_ENABLE;
 324         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 325         if (ret)
 326                 return ret;
 327         DBG("enabled handle %u", object->handle);
 328         return 0;
 329 }
 330
 331 /* Disable event, channel and session ioctl */
 332 int ustctl_disable(int sock, struct lttng_ust_object_data *object)
 333 {
 334         struct ustcomm_ust_msg lum;
 335         struct ustcomm_ust_reply lur;
 336         int ret;
 337
 338         if (!object)
 339                 return -EINVAL;
 340
 341         memset(&lum, 0, sizeof(lum));
 342         lum.handle = object->handle;
 343         lum.cmd = LTTNG_UST_DISABLE;
 344         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 345         if (ret)
 346                 return ret;
 347         DBG("disable handle %u", object->handle);
 348         return 0;
 349 }
 350
 351 int ustctl_start_session(int sock, int handle)
 352 {
 353         struct lttng_ust_object_data obj;
 354
 355         obj.handle = handle;
 356         return ustctl_enable(sock, &obj);
 357 }
 358
 359 int ustctl_stop_session(int sock, int handle)
 360 {
 361         struct lttng_ust_object_data obj;
 362
 363         obj.handle = handle;
 364         return ustctl_disable(sock, &obj);
 365 }
 366
 367 int ustctl_tracepoint_list(int sock)
 368 {
 369         struct ustcomm_ust_msg lum;
 370         struct ustcomm_ust_reply lur;
 371         int ret, tp_list_handle;
 372
 373         memset(&lum, 0, sizeof(lum));
 374         lum.handle = LTTNG_UST_ROOT_HANDLE;
 375         lum.cmd = LTTNG_UST_TRACEPOINT_LIST;
 376         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 377         if (ret)
 378                 return ret;
 379         tp_list_handle = lur.ret_val;
 380         DBG("received tracepoint list handle %u", tp_list_handle);
 381         return tp_list_handle;
 382 }
 383
 384 int ustctl_tracepoint_list_get(int sock, int tp_list_handle,
 385                 struct lttng_ust_tracepoint_iter *iter)
 386 {
 387         struct ustcomm_ust_msg lum;
 388         struct ustcomm_ust_reply lur;
 389         int ret;
 390
 391         if (!iter)
 392                 return -EINVAL;
 393
 394         memset(&lum, 0, sizeof(lum));
 395         lum.handle = tp_list_handle;
 396         lum.cmd = LTTNG_UST_TRACEPOINT_LIST_GET;
 397         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 398         if (ret)
 399                 return ret;
 400         DBG("received tracepoint list entry name %s loglevel %d",
 401                 lur.u.tracepoint.name,
 402                 lur.u.tracepoint.loglevel);
 403         memcpy(iter, &lur.u.tracepoint, sizeof(*iter));
 404         return 0;
 405 }
 406
 407 int ustctl_tracepoint_field_list(int sock)
 408 {
 409         struct ustcomm_ust_msg lum;
 410         struct ustcomm_ust_reply lur;
 411         int ret, tp_field_list_handle;
 412
 413         memset(&lum, 0, sizeof(lum));
 414         lum.handle = LTTNG_UST_ROOT_HANDLE;
 415         lum.cmd = LTTNG_UST_TRACEPOINT_FIELD_LIST;
 416         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 417         if (ret)
 418                 return ret;
 419         tp_field_list_handle = lur.ret_val;
 420         DBG("received tracepoint field list handle %u", tp_field_list_handle);
 421         return tp_field_list_handle;
 422 }
 423
 424 int ustctl_tracepoint_field_list_get(int sock, int tp_field_list_handle,
 425                 struct lttng_ust_field_iter *iter)
 426 {
 427         struct ustcomm_ust_msg lum;
 428         struct ustcomm_ust_reply lur;
 429         int ret;
 430         ssize_t len;
 431
 432         if (!iter)
 433                 return -EINVAL;
 434
 435         memset(&lum, 0, sizeof(lum));
 436         lum.handle = tp_field_list_handle;
 437         lum.cmd = LTTNG_UST_TRACEPOINT_FIELD_LIST_GET;
 438         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 439         if (ret)
 440                 return ret;
 441         len = ustcomm_recv_unix_sock(sock, iter, sizeof(*iter));
 442         if (len != sizeof(*iter)) {
 443                 return -EINVAL;
 444         }
 445         DBG("received tracepoint field list entry event_name %s event_loglevel %d field_name %s field_type %d",
 446                 iter->event_name,
 447                 iter->loglevel,
 448                 iter->field_name,
 449                 iter->type);
 450         return 0;
 451 }
 452
 453 int ustctl_tracer_version(int sock, struct lttng_ust_tracer_version *v)
 454 {
 455         struct ustcomm_ust_msg lum;
 456         struct ustcomm_ust_reply lur;
 457         int ret;
 458
 459         if (!v)
 460                 return -EINVAL;
 461
 462         memset(&lum, 0, sizeof(lum));
 463         lum.handle = LTTNG_UST_ROOT_HANDLE;
 464         lum.cmd = LTTNG_UST_TRACER_VERSION;
 465         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 466         if (ret)
 467                 return ret;
 468         memcpy(v, &lur.u.version, sizeof(*v));
 469         DBG("received tracer version");
 470         return 0;
 471 }
 472
 473 int ustctl_wait_quiescent(int sock)
 474 {
 475         struct ustcomm_ust_msg lum;
 476         struct ustcomm_ust_reply lur;
 477         int ret;
 478
 479         memset(&lum, 0, sizeof(lum));
 480         lum.handle = LTTNG_UST_ROOT_HANDLE;
 481         lum.cmd = LTTNG_UST_WAIT_QUIESCENT;
 482         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 483         if (ret)
 484                 return ret;
 485         DBG("waited for quiescent state");
 486         return 0;
 487 }
 488
 489 int ustctl_calibrate(int sock, struct lttng_ust_calibrate *calibrate)
 490 {
 491         if (!calibrate)
 492                 return -EINVAL;
 493
 494         return -ENOSYS;
 495 }
 496
 497 int ustctl_sock_flush_buffer(int sock, struct lttng_ust_object_data *object)
 498 {
 499         struct ustcomm_ust_msg lum;
 500         struct ustcomm_ust_reply lur;
 501         int ret;
 502
 503         if (!object)
 504                 return -EINVAL;
 505
 506         memset(&lum, 0, sizeof(lum));
 507         lum.handle = object->handle;
 508         lum.cmd = LTTNG_UST_FLUSH_BUFFER;
 509         ret = ustcomm_send_app_cmd(sock, &lum, &lur);
 510         if (ret)
 511                 return ret;
 512         DBG("flushed buffer handle %u", object->handle);
 513         return 0;
 514 }
 515
 516 static
 517 int ustctl_send_channel(int sock,
 518                 enum lttng_ust_chan_type type,
 519                 void *data,
 520                 uint64_t size,
 521                 int wakeup_fd,
 522                 int send_fd_only)
 523 {
 524         ssize_t len;
 525
 526         if (!send_fd_only) {
 527                 /* Send mmap size */
 528                 len = ustcomm_send_unix_sock(sock, &size, sizeof(size));
 529                 if (len != sizeof(size)) {
 530                         if (len < 0)
 531                                 return len;
 532                         else
 533                                 return -EIO;
 534                 }
 535
 536                 /* Send channel type */
 537                 len = ustcomm_send_unix_sock(sock, &type, sizeof(type));
 538                 if (len != sizeof(type)) {
 539                         if (len < 0)
 540                                 return len;
 541                         else
 542                                 return -EIO;
 543                 }
 544         }
 545
 546         /* Send channel data */
 547         len = ustcomm_send_unix_sock(sock, data, size);
 548         if (len != size) {
 549                 if (len < 0)
 550                         return len;
 551                 else
 552                         return -EIO;
 553         }
 554
 555         /* Send wakeup fd */
 556         len = ustcomm_send_fds_unix_sock(sock, &wakeup_fd, 1);
 557         if (len <= 0) {
 558                 if (len < 0)
 559                         return len;
 560                 else
 561                         return -EIO;
 562         }
 563         return 0;
 564 }
 565
 566 static
 567 int ustctl_send_stream(int sock,
 568                 uint32_t stream_nr,
 569                 uint64_t memory_map_size,
 570                 int shm_fd, int wakeup_fd,
 571                 int send_fd_only)
 572 {
 573         ssize_t len;
 574         int fds[2];
 575
 576         if (!send_fd_only) {
 577                 if (shm_fd < 0) {
 578                         /* finish iteration */
 579                         uint64_t v = -1;
 580
 581                         len = ustcomm_send_unix_sock(sock, &v, sizeof(v));
 582                         if (len != sizeof(v)) {
 583                                 if (len < 0)
 584                                         return len;
 585                                 else
 586                                         return -EIO;
 587                         }
 588                         return 0;
 589                 }
 590
 591                 /* Send mmap size */
 592                 len = ustcomm_send_unix_sock(sock, &memory_map_size,
 593                         sizeof(memory_map_size));
 594                 if (len != sizeof(memory_map_size)) {
 595                         if (len < 0)
 596                                 return len;
 597                         else
 598                                 return -EIO;
 599                 }
 600
 601                 /* Send stream nr */
 602                 len = ustcomm_send_unix_sock(sock, &stream_nr,
 603                         sizeof(stream_nr));
 604                 if (len != sizeof(stream_nr)) {
 605                         if (len < 0)
 606                                 return len;
 607                         else
 608                                 return -EIO;
 609                 }
 610         }
 611
 612         /* Send shm fd and wakeup fd */
 613         fds[0] = shm_fd;
 614         fds[1] = wakeup_fd;
 615         len = ustcomm_send_fds_unix_sock(sock, fds, 2);
 616         if (len <= 0) {
 617                 if (len < 0)
 618                         return len;
 619                 else
 620                         return -EIO;
 621         }
 622         return 0;
 623 }
 624
 625 int ustctl_recv_channel_from_consumer(int sock,
 626                 struct lttng_ust_object_data **_channel_data)
 627 {
 628         struct lttng_ust_object_data *channel_data;
 629         ssize_t len;
 630         int wakeup_fd;
 631         int ret;
 632
 633         channel_data = zmalloc(sizeof(*channel_data));
 634         if (!channel_data) {
 635                 ret = -ENOMEM;
 636                 goto error_alloc;
 637         }
 638         channel_data->type = LTTNG_UST_OBJECT_TYPE_CHANNEL;
 639         channel_data->handle = -1;
 640
 641         /* recv mmap size */
 642         len = ustcomm_recv_unix_sock(sock, &channel_data->size,
 643                         sizeof(channel_data->size));
 644         if (len != sizeof(channel_data->size)) {
 645                 if (len < 0)
 646                         ret = len;
 647                 else
 648                         ret = -EINVAL;
 649                 goto error;
 650         }
 651
 652         /* recv channel type */
 653         len = ustcomm_recv_unix_sock(sock, &channel_data->u.channel.type,
 654                         sizeof(channel_data->u.channel.type));
 655         if (len != sizeof(channel_data->u.channel.type)) {
 656                 if (len < 0)
 657                         ret = len;
 658                 else
 659                         ret = -EINVAL;
 660                 goto error;
 661         }
 662
 663         /* recv channel data */
 664         channel_data->u.channel.data = zmalloc(channel_data->size);
 665         if (!channel_data->u.channel.data) {
 666                 ret = -ENOMEM;
 667                 goto error;
 668         }
 669         len = ustcomm_recv_unix_sock(sock, channel_data->u.channel.data,
 670                         channel_data->size);
 671         if (len != channel_data->size) {
 672                 if (len < 0)
 673                         ret = len;
 674                 else
 675                         ret = -EINVAL;
 676                 goto error_recv_data;
 677         }
 678         /* recv wakeup fd */
 679         len = ustcomm_recv_fds_unix_sock(sock, &wakeup_fd, 1);
 680         if (len <= 0) {
 681                 if (len < 0) {
 682                         ret = len;
 683                         goto error_recv_data;
 684                 } else {
 685                         ret = -EIO;
 686                         goto error_recv_data;
 687                 }
 688         }
 689         channel_data->u.channel.wakeup_fd = wakeup_fd;
 690         *_channel_data = channel_data;
 691         return 0;
 692
 693 error_recv_data:
 694         free(channel_data->u.channel.data);
 695 error:
 696         free(channel_data);
 697 error_alloc:
 698         return ret;
 699 }
 700
 701 int ustctl_recv_stream_from_consumer(int sock,
 702                 struct lttng_ust_object_data **_stream_data)
 703 {
 704         struct lttng_ust_object_data *stream_data;
 705         ssize_t len;
 706         int ret;
 707         int fds[2];
 708
 709         stream_data = zmalloc(sizeof(*stream_data));
 710         if (!stream_data) {
 711                 ret = -ENOMEM;
 712                 goto error_alloc;
 713         }
 714
 715         stream_data->type = LTTNG_UST_OBJECT_TYPE_STREAM;
 716         stream_data->handle = -1;
 717
 718         /* recv mmap size */
 719         len = ustcomm_recv_unix_sock(sock, &stream_data->size,
 720                         sizeof(stream_data->size));
 721         if (len != sizeof(stream_data->size)) {
 722                 if (len < 0)
 723                         ret = len;
 724                 else
 725                         ret = -EINVAL;
 726                 goto error;
 727         }
 728         if (stream_data->size == -1) {
 729                 ret = -LTTNG_UST_ERR_NOENT;
 730                 goto error;
 731         }
 732
 733         /* recv stream nr */
 734         len = ustcomm_recv_unix_sock(sock, &stream_data->u.stream.stream_nr,
 735                         sizeof(stream_data->u.stream.stream_nr));
 736         if (len != sizeof(stream_data->u.stream.stream_nr)) {
 737                 if (len < 0)
 738                         ret = len;
 739                 else
 740                         ret = -EINVAL;
 741                 goto error;
 742         }
 743
 744         /* recv shm fd and wakeup fd */
 745         len = ustcomm_recv_fds_unix_sock(sock, fds, 2);
 746         if (len <= 0) {
 747                 if (len < 0) {
 748                         ret = len;
 749                         goto error;
 750                 } else {
 751                         ret = -EIO;
 752                         goto error;
 753                 }
 754         }
 755         stream_data->u.stream.shm_fd = fds[0];
 756         stream_data->u.stream.wakeup_fd = fds[1];
 757         *_stream_data = stream_data;
 758         return 0;
 759
 760 error:
 761         free(stream_data);
 762 error_alloc:
 763         return ret;
 764 }
 765
 766 int ustctl_send_channel_to_ust(int sock, int session_handle,
 767                 struct lttng_ust_object_data *channel_data)
 768 {
 769         struct ustcomm_ust_msg lum;
 770         struct ustcomm_ust_reply lur;
 771         int ret;
 772
 773         if (!channel_data)
 774                 return -EINVAL;
 775
 776         memset(&lum, 0, sizeof(lum));
 777         lum.handle = session_handle;
 778         lum.cmd = LTTNG_UST_CHANNEL;
 779         lum.u.channel.len = channel_data->size;
 780         lum.u.channel.type = channel_data->u.channel.type;
 781         ret = ustcomm_send_app_msg(sock, &lum);
 782         if (ret)
 783                 return ret;
 784
 785         ret = ustctl_send_channel(sock,
 786                         channel_data->u.channel.type,
 787                         channel_data->u.channel.data,
 788                         channel_data->size,
 789                         channel_data->u.channel.wakeup_fd,
 790                         1);
 791         if (ret)
 792                 return ret;
 793         ret = ustcomm_recv_app_reply(sock, &lur, lum.handle, lum.cmd);
 794         if (!ret) {
 795                 channel_data->handle = lur.ret_val;
 796         }
 797         return ret;
 798 }
 799
 800 int ustctl_send_stream_to_ust(int sock,
 801                 struct lttng_ust_object_data *channel_data,
 802                 struct lttng_ust_object_data *stream_data)
 803 {
 804         struct ustcomm_ust_msg lum;
 805         struct ustcomm_ust_reply lur;
 806         int ret;
 807
 808         memset(&lum, 0, sizeof(lum));
 809         lum.handle = channel_data->handle;
 810         lum.cmd = LTTNG_UST_STREAM;
 811         lum.u.stream.len = stream_data->size;
 812         lum.u.stream.stream_nr = stream_data->u.stream.stream_nr;
 813         ret = ustcomm_send_app_msg(sock, &lum);
 814         if (ret)
 815                 return ret;
 816
 817         assert(stream_data);
 818         assert(stream_data->type == LTTNG_UST_OBJECT_TYPE_STREAM);
 819
 820         ret = ustctl_send_stream(sock,
 821                         stream_data->u.stream.stream_nr,
 822                         stream_data->size,
 823                         stream_data->u.stream.shm_fd,
 824                         stream_data->u.stream.wakeup_fd, 1);
 825         if (ret)
 826                 return ret;
 827         return ustcomm_recv_app_reply(sock, &lur, lum.handle, lum.cmd);
 828 }
 829
 830 int ustctl_duplicate_ust_object_data(struct lttng_ust_object_data **dest,
 831                 struct lttng_ust_object_data *src)
 832 {
 833         struct lttng_ust_object_data *obj;
 834         int ret;
 835
 836         if (src->handle != -1) {
 837                 ret = -EINVAL;
 838                 goto error;
 839         }
 840
 841         obj = zmalloc(sizeof(*obj));
 842         if (!obj) {
 843                 ret = -ENOMEM;
 844                 goto error;
 845         }
 846
 847         obj->type = src->type;
 848         obj->handle = src->handle;
 849         obj->size = src->size;
 850
 851         switch (obj->type) {
 852         case LTTNG_UST_OBJECT_TYPE_CHANNEL:
 853         {
 854                 obj->u.channel.type = src->u.channel.type;
 855                 if (src->u.channel.wakeup_fd >= 0) {
 856                         obj->u.channel.wakeup_fd =
 857                                 dup(src->u.channel.wakeup_fd);
 858                         if (obj->u.channel.wakeup_fd < 0) {
 859                                 ret = errno;
 860                                 goto chan_error_wakeup_fd;
 861                         }
 862                 } else {
 863                         obj->u.channel.wakeup_fd =
 864                                 src->u.channel.wakeup_fd;
 865                 }
 866                 obj->u.channel.data = zmalloc(obj->size);
 867                 if (!obj->u.channel.data) {
 868                         ret = -ENOMEM;
 869                         goto chan_error_alloc;
 870                 }
 871                 memcpy(obj->u.channel.data, src->u.channel.data, obj->size);
 872                 break;
 873
 874         chan_error_alloc:
 875                 if (src->u.channel.wakeup_fd >= 0) {
 876                         int closeret;
 877
 878                         closeret = close(obj->u.channel.wakeup_fd);
 879                         if (closeret) {
 880                                 PERROR("close");
 881                         }
 882                 }
 883         chan_error_wakeup_fd:
 884                 goto error_type;
 885
 886         }
 887
 888         case LTTNG_UST_OBJECT_TYPE_STREAM:
 889         {
 890                 obj->u.stream.stream_nr = src->u.stream.stream_nr;
 891                 if (src->u.stream.wakeup_fd >= 0) {
 892                         obj->u.stream.wakeup_fd =
 893                                 dup(src->u.stream.wakeup_fd);
 894                         if (obj->u.stream.wakeup_fd < 0) {
 895                                 ret = errno;
 896                                 goto stream_error_wakeup_fd;
 897                         }
 898                 } else {
 899                         obj->u.stream.wakeup_fd =
 900                                 src->u.stream.wakeup_fd;
 901                 }
 902
 903                 if (src->u.stream.shm_fd >= 0) {
 904                         obj->u.stream.shm_fd =
 905                                 dup(src->u.stream.shm_fd);
 906                         if (obj->u.stream.shm_fd < 0) {
 907                                 ret = errno;
 908                                 goto stream_error_shm_fd;
 909                         }
 910                 } else {
 911                         obj->u.stream.shm_fd =
 912                                 src->u.stream.shm_fd;
 913                 }
 914                 break;
 915
 916         stream_error_shm_fd:
 917                 if (src->u.stream.wakeup_fd >= 0) {
 918                         int closeret;
 919
 920                         closeret = close(obj->u.stream.wakeup_fd);
 921                         if (closeret) {
 922                                 PERROR("close");
 923                         }
 924                 }
 925         stream_error_wakeup_fd:
 926                 goto error_type;
 927         }
 928
 929         default:
 930                 ret = -EINVAL;
 931                 goto error_type;
 932         }
 933
 934         *dest = obj;
 935         return 0;
 936
 937 error_type:
 938         free(obj);
 939 error:
 940         return ret;
 941 }
 942
 943
 944 /* Buffer operations */
 945
 946 int ustctl_get_nr_stream_per_channel(void)
 947 {
 948         return num_possible_cpus();
 949 }
 950
 951 struct ustctl_consumer_channel *
 952         ustctl_create_channel(struct ustctl_consumer_channel_attr *attr,
 953                 const int *stream_fds, int nr_stream_fds)
 954 {
 955         struct ustctl_consumer_channel *chan;
 956         const char *transport_name;
 957         struct lttng_transport *transport;
 958
 959         switch (attr->type) {
 960         case LTTNG_UST_CHAN_PER_CPU:
 961                 if (attr->output == LTTNG_UST_MMAP) {
 962                         if (attr->overwrite) {
 963                                 if (attr->read_timer_interval == 0) {
 964                                         transport_name = "relay-overwrite-mmap";
 965                                 } else {
 966                                         transport_name = "relay-overwrite-rt-mmap";
 967                                 }
 968                         } else {
 969                                 if (attr->read_timer_interval == 0) {
 970                                         transport_name = "relay-discard-mmap";
 971                                 } else {
 972                                         transport_name = "relay-discard-rt-mmap";
 973                                 }
 974                         }
 975                 } else {
 976                         return NULL;
 977                 }
 978                 break;
 979         case LTTNG_UST_CHAN_METADATA:
 980                 if (attr->output == LTTNG_UST_MMAP)
 981                         transport_name = "relay-metadata-mmap";
 982                 else
 983                         return NULL;
 984                 break;
 985         default:
 986                 transport_name = "<unknown>";
 987                 return NULL;
 988         }
 989
 990         transport = lttng_transport_find(transport_name);
 991         if (!transport) {
 992                 DBG("LTTng transport %s not found\n",
 993                         transport_name);
 994                 return NULL;
 995         }
 996
 997         chan = zmalloc(sizeof(*chan));
 998         if (!chan)
 999                 return NULL;
1000
1001         chan->chan = transport->ops.channel_create(transport_name, NULL,
1002                         attr->subbuf_size, attr->num_subbuf,
1003                         attr->switch_timer_interval,
1004                         attr->read_timer_interval,
1005                         attr->uuid, attr->chan_id,
1006                         stream_fds, nr_stream_fds);
1007         if (!chan->chan) {
1008                 goto chan_error;
1009         }
1010         chan->chan->ops = &transport->ops;
1011         memcpy(&chan->attr, attr, sizeof(chan->attr));
1012         chan->wait_fd = ustctl_channel_get_wait_fd(chan);
1013         chan->wakeup_fd = ustctl_channel_get_wakeup_fd(chan);
1014         return chan;
1015
1016 chan_error:
1017         free(chan);
1018         return NULL;
1019 }
1020
1021 void ustctl_destroy_channel(struct ustctl_consumer_channel *chan)
1022 {
1023         (void) ustctl_channel_close_wait_fd(chan);
1024         (void) ustctl_channel_close_wakeup_fd(chan);
1025         chan->chan->ops->channel_destroy(chan->chan);
1026         free(chan);
1027 }
1028
1029 int ustctl_send_channel_to_sessiond(int sock,
1030                 struct ustctl_consumer_channel *channel)
1031 {
1032         struct shm_object_table *table;
1033
1034         table = channel->chan->handle->table;
1035         if (table->size <= 0)
1036                 return -EINVAL;
1037         return ustctl_send_channel(sock,
1038                         channel->attr.type,
1039                         table->objects[0].memory_map,
1040                         table->objects[0].memory_map_size,
1041                         channel->wakeup_fd,
1042                         0);
1043 }
1044
1045 int ustctl_send_stream_to_sessiond(int sock,
1046                 struct ustctl_consumer_stream *stream)
1047 {
1048         if (!stream)
1049                 return ustctl_send_stream(sock, -1U, -1U, -1, -1, 0);
1050
1051         return ustctl_send_stream(sock,
1052                         stream->cpu,
1053                         stream->memory_map_size,
1054                         stream->shm_fd, stream->wakeup_fd,
1055                         0);
1056 }
1057
1058 int ustctl_write_metadata_to_channel(
1059                 struct ustctl_consumer_channel *channel,
1060                 const char *metadata_str,       /* NOT null-terminated */
1061                 size_t len)                     /* metadata length */
1062 {
1063         struct lttng_ust_lib_ring_buffer_ctx ctx;
1064         struct lttng_channel *chan = channel->chan;
1065         const char *str = metadata_str;
1066         int ret = 0, waitret;
1067         size_t reserve_len, pos;
1068
1069         for (pos = 0; pos < len; pos += reserve_len) {
1070                 reserve_len = min_t(size_t,
1071                                 chan->ops->packet_avail_size(chan->chan, chan->handle),
1072                                 len - pos);
1073                 lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
1074                                          sizeof(char), -1, chan->handle);
1075                 /*
1076                  * We don't care about metadata buffer's records lost
1077                  * count, because we always retry here. Report error if
1078                  * we need to bail out after timeout or being
1079                  * interrupted.
1080                  */
1081                 waitret = wait_cond_interruptible_timeout(
1082                         ({
1083                                 ret = chan->ops->event_reserve(&ctx, 0);
1084                                 ret != -ENOBUFS || !ret;
1085                         }),
1086                         LTTNG_METADATA_TIMEOUT_MSEC);
1087                 if (waitret == -ETIMEDOUT || waitret == -EINTR || ret) {
1088                         DBG("LTTng: Failure to write metadata to buffers (%s)\n",
1089                                 waitret == -EINTR ? "interrupted" :
1090                                         (ret == -ENOBUFS ? "timeout" : "I/O error"));
1091                         if (waitret == -EINTR)
1092                                 ret = waitret;
1093                         goto end;
1094                 }
1095                 chan->ops->event_write(&ctx, &str[pos], reserve_len);
1096                 chan->ops->event_commit(&ctx);
1097         }
1098 end:
1099         return ret;
1100 }
1101
1102 /*
1103  * Write at most one packet in the channel.
1104  * Returns the number of bytes written on success, < 0 on error.
1105  */
1106 ssize_t ustctl_write_one_packet_to_channel(
1107                 struct ustctl_consumer_channel *channel,
1108                 const char *metadata_str,       /* NOT null-terminated */
1109                 size_t len)                     /* metadata length */
1110 {
1111         struct lttng_ust_lib_ring_buffer_ctx ctx;
1112         struct lttng_channel *chan = channel->chan;
1113         const char *str = metadata_str;
1114         ssize_t reserve_len;
1115         int ret;
1116
1117         reserve_len = min_t(ssize_t,
1118                         chan->ops->packet_avail_size(chan->chan, chan->handle),
1119                         len);
1120         lib_ring_buffer_ctx_init(&ctx, chan->chan, NULL, reserve_len,
1121                         sizeof(char), -1, chan->handle);
1122         ret = chan->ops->event_reserve(&ctx, 0);
1123         if (ret != 0) {
1124                 DBG("LTTng: event reservation failed");
1125                 assert(ret < 0);
1126                 reserve_len = ret;
1127                 goto end;
1128         }
1129         chan->ops->event_write(&ctx, str, reserve_len);
1130         chan->ops->event_commit(&ctx);
1131
1132 end:
1133         return reserve_len;
1134 }
1135
1136 int ustctl_channel_close_wait_fd(struct ustctl_consumer_channel *consumer_chan)
1137 {
1138         struct channel *chan;
1139         int ret;
1140
1141         chan = consumer_chan->chan->chan;
1142         ret = ring_buffer_channel_close_wait_fd(&chan->backend.config,
1143                         chan, chan->handle);
1144         if (!ret)
1145                 consumer_chan->wait_fd = -1;
1146         return ret;
1147 }
1148
1149 int ustctl_channel_close_wakeup_fd(struct ustctl_consumer_channel *consumer_chan)
1150 {
1151         struct channel *chan;
1152         int ret;
1153
1154         chan = consumer_chan->chan->chan;
1155         ret = ring_buffer_channel_close_wakeup_fd(&chan->backend.config,
1156                         chan, chan->handle);
1157         if (!ret)
1158                 consumer_chan->wakeup_fd = -1;
1159         return ret;
1160 }
1161
1162 int ustctl_stream_close_wait_fd(struct ustctl_consumer_stream *stream)
1163 {
1164         struct channel *chan;
1165
1166         chan = stream->chan->chan->chan;
1167         return ring_buffer_stream_close_wait_fd(&chan->backend.config,
1168                         chan, stream->handle, stream->cpu);
1169 }
1170
1171 int ustctl_stream_close_wakeup_fd(struct ustctl_consumer_stream *stream)
1172 {
1173         struct channel *chan;
1174
1175         chan = stream->chan->chan->chan;
1176         return ring_buffer_stream_close_wakeup_fd(&chan->backend.config,
1177                         chan, stream->handle, stream->cpu);
1178 }
1179
1180 struct ustctl_consumer_stream *
1181         ustctl_create_stream(struct ustctl_consumer_channel *channel,
1182                         int cpu)
1183 {
1184         struct ustctl_consumer_stream *stream;
1185         struct lttng_ust_shm_handle *handle;
1186         struct channel *chan;
1187         int shm_fd, wait_fd, wakeup_fd;
1188         uint64_t memory_map_size;
1189         struct lttng_ust_lib_ring_buffer *buf;
1190         int ret;
1191
1192         if (!channel)
1193                 return NULL;
1194         handle = channel->chan->handle;
1195         if (!handle)
1196                 return NULL;
1197
1198         chan = channel->chan->chan;
1199         buf = channel_get_ring_buffer(&chan->backend.config,
1200                 chan, cpu, handle, &shm_fd, &wait_fd,
1201                 &wakeup_fd, &memory_map_size);
1202         if (!buf)
1203                 return NULL;
1204         ret = lib_ring_buffer_open_read(buf, handle);
1205         if (ret)
1206                 return NULL;
1207
1208         stream = zmalloc(sizeof(*stream));
1209         if (!stream)
1210                 goto alloc_error;
1211         stream->handle = handle;
1212         stream->buf = buf;
1213         stream->chan = channel;
1214         stream->shm_fd = shm_fd;
1215         stream->wait_fd = wait_fd;
1216         stream->wakeup_fd = wakeup_fd;
1217         stream->memory_map_size = memory_map_size;
1218         stream->cpu = cpu;
1219         return stream;
1220
1221 alloc_error:
1222         return NULL;
1223 }
1224
1225 void ustctl_destroy_stream(struct ustctl_consumer_stream *stream)
1226 {
1227         struct lttng_ust_lib_ring_buffer *buf;
1228         struct ustctl_consumer_channel *consumer_chan;
1229
1230         assert(stream);
1231         buf = stream->buf;
1232         consumer_chan = stream->chan;
1233         (void) ustctl_stream_close_wait_fd(stream);
1234         (void) ustctl_stream_close_wakeup_fd(stream);
1235         lib_ring_buffer_release_read(buf, consumer_chan->chan->handle);
1236         free(stream);
1237 }
1238
1239 int ustctl_channel_get_wait_fd(struct ustctl_consumer_channel *chan)
1240 {
1241         if (!chan)
1242                 return -EINVAL;
1243         return shm_get_wait_fd(chan->chan->handle,
1244                 &chan->chan->handle->chan._ref);
1245 }
1246
1247 int ustctl_channel_get_wakeup_fd(struct ustctl_consumer_channel *chan)
1248 {
1249         if (!chan)
1250                 return -EINVAL;
1251         return shm_get_wakeup_fd(chan->chan->handle,
1252                 &chan->chan->handle->chan._ref);
1253 }
1254
1255 int ustctl_stream_get_wait_fd(struct ustctl_consumer_stream *stream)
1256 {
1257         struct lttng_ust_lib_ring_buffer *buf;
1258         struct ustctl_consumer_channel *consumer_chan;
1259
1260         if (!stream)
1261                 return -EINVAL;
1262         buf = stream->buf;
1263         consumer_chan = stream->chan;
1264         return shm_get_wait_fd(consumer_chan->chan->handle, &buf->self._ref);
1265 }
1266
1267 int ustctl_stream_get_wakeup_fd(struct ustctl_consumer_stream *stream)
1268 {
1269         struct lttng_ust_lib_ring_buffer *buf;
1270         struct ustctl_consumer_channel *consumer_chan;
1271
1272         if (!stream)
1273                 return -EINVAL;
1274         buf = stream->buf;
1275         consumer_chan = stream->chan;
1276         return shm_get_wakeup_fd(consumer_chan->chan->handle, &buf->self._ref);
1277 }
1278
1279 /* For mmap mode, readable without "get" operation */
1280
1281 void *ustctl_get_mmap_base(struct ustctl_consumer_stream *stream)
1282 {
1283         struct lttng_ust_lib_ring_buffer *buf;
1284         struct ustctl_consumer_channel *consumer_chan;
1285
1286         if (!stream)
1287                 return NULL;
1288         buf = stream->buf;
1289         consumer_chan = stream->chan;
1290         return shmp(consumer_chan->chan->handle, buf->backend.memory_map);
1291 }
1292
1293 /* returns the length to mmap. */
1294 int ustctl_get_mmap_len(struct ustctl_consumer_stream *stream,
1295                 unsigned long *len)
1296 {
1297         struct ustctl_consumer_channel *consumer_chan;
1298         unsigned long mmap_buf_len;
1299         struct channel *chan;
1300
1301         if (!stream)
1302                 return -EINVAL;
1303         consumer_chan = stream->chan;
1304         chan = consumer_chan->chan->chan;
1305         if (chan->backend.config.output != RING_BUFFER_MMAP)
1306                 return -EINVAL;
1307         mmap_buf_len = chan->backend.buf_size;
1308         if (chan->backend.extra_reader_sb)
1309                 mmap_buf_len += chan->backend.subbuf_size;
1310         if (mmap_buf_len > INT_MAX)
1311                 return -EFBIG;
1312         *len = mmap_buf_len;
1313         return 0;
1314 }
1315
1316 /* returns the maximum size for sub-buffers. */
1317 int ustctl_get_max_subbuf_size(struct ustctl_consumer_stream *stream,
1318                 unsigned long *len)
1319 {
1320         struct ustctl_consumer_channel *consumer_chan;
1321         struct channel *chan;
1322
1323         if (!stream)
1324                 return -EINVAL;
1325         consumer_chan = stream->chan;
1326         chan = consumer_chan->chan->chan;
1327         *len = chan->backend.subbuf_size;
1328         return 0;
1329 }
1330
1331 /*
1332  * For mmap mode, operate on the current packet (between get/put or
1333  * get_next/put_next).
1334  */
1335
1336 /* returns the offset of the subbuffer belonging to the mmap reader. */
1337 int ustctl_get_mmap_read_offset(struct ustctl_consumer_stream *stream,
1338                 unsigned long *off)
1339 {
1340         struct channel *chan;
1341         unsigned long sb_bindex;
1342         struct lttng_ust_lib_ring_buffer *buf;
1343         struct ustctl_consumer_channel *consumer_chan;
1344
1345         if (!stream)
1346                 return -EINVAL;
1347         buf = stream->buf;
1348         consumer_chan = stream->chan;
1349         chan = consumer_chan->chan->chan;
1350         if (chan->backend.config.output != RING_BUFFER_MMAP)
1351                 return -EINVAL;
1352         sb_bindex = subbuffer_id_get_index(&chan->backend.config,
1353                                         buf->backend.buf_rsb.id);
1354         *off = shmp(consumer_chan->chan->handle,
1355                 shmp_index(consumer_chan->chan->handle, buf->backend.array, sb_bindex)->shmp)->mmap_offset;
1356         return 0;
1357 }
1358
1359 /* returns the size of the current sub-buffer, without padding (for mmap). */
1360 int ustctl_get_subbuf_size(struct ustctl_consumer_stream *stream,
1361                 unsigned long *len)
1362 {
1363         struct ustctl_consumer_channel *consumer_chan;
1364         struct channel *chan;
1365         struct lttng_ust_lib_ring_buffer *buf;
1366
1367         if (!stream)
1368                 return -EINVAL;
1369
1370         buf = stream->buf;
1371         consumer_chan = stream->chan;
1372         chan = consumer_chan->chan->chan;
1373         *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf,
1374                 consumer_chan->chan->handle);
1375         return 0;
1376 }
1377
1378 /* returns the size of the current sub-buffer, without padding (for mmap). */
1379 int ustctl_get_padded_subbuf_size(struct ustctl_consumer_stream *stream,
1380                 unsigned long *len)
1381 {
1382         struct ustctl_consumer_channel *consumer_chan;
1383         struct channel *chan;
1384         struct lttng_ust_lib_ring_buffer *buf;
1385
1386         if (!stream)
1387                 return -EINVAL;
1388         buf = stream->buf;
1389         consumer_chan = stream->chan;
1390         chan = consumer_chan->chan->chan;
1391         *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf,
1392                 consumer_chan->chan->handle);
1393         *len = PAGE_ALIGN(*len);
1394         return 0;
1395 }
1396
1397 /* Get exclusive read access to the next sub-buffer that can be read. */
1398 int ustctl_get_next_subbuf(struct ustctl_consumer_stream *stream)
1399 {
1400         struct lttng_ust_lib_ring_buffer *buf;
1401         struct ustctl_consumer_channel *consumer_chan;
1402
1403         if (!stream)
1404                 return -EINVAL;
1405         buf = stream->buf;
1406         consumer_chan = stream->chan;
1407         return lib_ring_buffer_get_next_subbuf(buf,
1408                         consumer_chan->chan->handle);
1409 }
1410
1411
1412 /* Release exclusive sub-buffer access, move consumer forward. */
1413 int ustctl_put_next_subbuf(struct ustctl_consumer_stream *stream)
1414 {
1415         struct lttng_ust_lib_ring_buffer *buf;
1416         struct ustctl_consumer_channel *consumer_chan;
1417
1418         if (!stream)
1419                 return -EINVAL;
1420         buf = stream->buf;
1421         consumer_chan = stream->chan;
1422         lib_ring_buffer_put_next_subbuf(buf, consumer_chan->chan->handle);
1423         return 0;
1424 }
1425
1426 /* snapshot */
1427
1428 /* Get a snapshot of the current ring buffer producer and consumer positions */
1429 int ustctl_snapshot(struct ustctl_consumer_stream *stream)
1430 {
1431         struct lttng_ust_lib_ring_buffer *buf;
1432         struct ustctl_consumer_channel *consumer_chan;
1433
1434         if (!stream)
1435                 return -EINVAL;
1436         buf = stream->buf;
1437         consumer_chan = stream->chan;
1438         return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
1439                         &buf->prod_snapshot, consumer_chan->chan->handle);
1440 }
1441
1442 /* Get the consumer position (iteration start) */
1443 int ustctl_snapshot_get_consumed(struct ustctl_consumer_stream *stream,
1444                 unsigned long *pos)
1445 {
1446         struct lttng_ust_lib_ring_buffer *buf;
1447
1448         if (!stream)
1449                 return -EINVAL;
1450         buf = stream->buf;
1451         *pos = buf->cons_snapshot;
1452         return 0;
1453 }
1454
1455 /* Get the producer position (iteration end) */
1456 int ustctl_snapshot_get_produced(struct ustctl_consumer_stream *stream,
1457                 unsigned long *pos)
1458 {
1459         struct lttng_ust_lib_ring_buffer *buf;
1460
1461         if (!stream)
1462                 return -EINVAL;
1463         buf = stream->buf;
1464         *pos = buf->prod_snapshot;
1465         return 0;
1466 }
1467
1468 /* Get exclusive read access to the specified sub-buffer position */
1469 int ustctl_get_subbuf(struct ustctl_consumer_stream *stream,
1470                 unsigned long *pos)
1471 {
1472         struct lttng_ust_lib_ring_buffer *buf;
1473         struct ustctl_consumer_channel *consumer_chan;
1474
1475         if (!stream)
1476                 return -EINVAL;
1477         buf = stream->buf;
1478         consumer_chan = stream->chan;
1479         return lib_ring_buffer_get_subbuf(buf, *pos,
1480                         consumer_chan->chan->handle);
1481 }
1482
1483 /* Release exclusive sub-buffer access */
1484 int ustctl_put_subbuf(struct ustctl_consumer_stream *stream)
1485 {
1486         struct lttng_ust_lib_ring_buffer *buf;
1487         struct ustctl_consumer_channel *consumer_chan;
1488
1489         if (!stream)
1490                 return -EINVAL;
1491         buf = stream->buf;
1492         consumer_chan = stream->chan;
1493         lib_ring_buffer_put_subbuf(buf, consumer_chan->chan->handle);
1494         return 0;
1495 }
1496
1497 void ustctl_flush_buffer(struct ustctl_consumer_stream *stream,
1498                 int producer_active)
1499 {
1500         struct lttng_ust_lib_ring_buffer *buf;
1501         struct ustctl_consumer_channel *consumer_chan;
1502
1503         assert(stream);
1504         buf = stream->buf;
1505         consumer_chan = stream->chan;
1506         lib_ring_buffer_switch_slow(buf,
1507                 producer_active ? SWITCH_ACTIVE : SWITCH_FLUSH,
1508                 consumer_chan->chan->handle);
1509 }
1510
1511 static
1512 struct lttng_ust_client_lib_ring_buffer_client_cb *get_client_cb(
1513                 struct lttng_ust_lib_ring_buffer *buf,
1514                 struct lttng_ust_shm_handle *handle)
1515 {
1516         struct channel *chan;
1517         const struct lttng_ust_lib_ring_buffer_config *config;
1518         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1519
1520         chan = shmp(handle, buf->backend.chan);
1521         config = &chan->backend.config;
1522         if (!config->cb_ptr)
1523                 return NULL;
1524         client_cb = caa_container_of(config->cb_ptr,
1525                         struct lttng_ust_client_lib_ring_buffer_client_cb,
1526                         parent);
1527         return client_cb;
1528 }
1529
1530 int ustctl_get_timestamp_begin(struct ustctl_consumer_stream *stream,
1531                 uint64_t *timestamp_begin)
1532 {
1533         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1534         struct lttng_ust_lib_ring_buffer *buf;
1535         struct lttng_ust_shm_handle *handle;
1536
1537         if (!stream || !timestamp_begin)
1538                 return -EINVAL;
1539         buf = stream->buf;
1540         handle = stream->chan->chan->handle;
1541         client_cb = get_client_cb(buf, handle);
1542         if (!client_cb)
1543                 return -ENOSYS;
1544         return client_cb->timestamp_begin(buf, handle, timestamp_begin);
1545 }
1546
1547 int ustctl_get_timestamp_end(struct ustctl_consumer_stream *stream,
1548         uint64_t *timestamp_end)
1549 {
1550         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1551         struct lttng_ust_lib_ring_buffer *buf;
1552         struct lttng_ust_shm_handle *handle;
1553
1554         if (!stream || !timestamp_end)
1555                 return -EINVAL;
1556         buf = stream->buf;
1557         handle = stream->chan->chan->handle;
1558         client_cb = get_client_cb(buf, handle);
1559         if (!client_cb)
1560                 return -ENOSYS;
1561         return client_cb->timestamp_end(buf, handle, timestamp_end);
1562 }
1563
1564 int ustctl_get_events_discarded(struct ustctl_consumer_stream *stream,
1565         uint64_t *events_discarded)
1566 {
1567         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1568         struct lttng_ust_lib_ring_buffer *buf;
1569         struct lttng_ust_shm_handle *handle;
1570
1571         if (!stream || !events_discarded)
1572                 return -EINVAL;
1573         buf = stream->buf;
1574         handle = stream->chan->chan->handle;
1575         client_cb = get_client_cb(buf, handle);
1576         if (!client_cb)
1577                 return -ENOSYS;
1578         return client_cb->events_discarded(buf, handle, events_discarded);
1579 }
1580
1581 int ustctl_get_content_size(struct ustctl_consumer_stream *stream,
1582         uint64_t *content_size)
1583 {
1584         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1585         struct lttng_ust_lib_ring_buffer *buf;
1586         struct lttng_ust_shm_handle *handle;
1587
1588         if (!stream || !content_size)
1589                 return -EINVAL;
1590         buf = stream->buf;
1591         handle = stream->chan->chan->handle;
1592         client_cb = get_client_cb(buf, handle);
1593         if (!client_cb)
1594                 return -ENOSYS;
1595         return client_cb->content_size(buf, handle, content_size);
1596 }
1597
1598 int ustctl_get_packet_size(struct ustctl_consumer_stream *stream,
1599         uint64_t *packet_size)
1600 {
1601         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1602         struct lttng_ust_lib_ring_buffer *buf;
1603         struct lttng_ust_shm_handle *handle;
1604
1605         if (!stream || !packet_size)
1606                 return -EINVAL;
1607         buf = stream->buf;
1608         handle = stream->chan->chan->handle;
1609         client_cb = get_client_cb(buf, handle);
1610         if (!client_cb)
1611                 return -ENOSYS;
1612         return client_cb->packet_size(buf, handle, packet_size);
1613 }
1614
1615 int ustctl_get_stream_id(struct ustctl_consumer_stream *stream,
1616                 uint64_t *stream_id)
1617 {
1618         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1619         struct lttng_ust_lib_ring_buffer *buf;
1620         struct lttng_ust_shm_handle *handle;
1621
1622         if (!stream || !stream_id)
1623                 return -EINVAL;
1624         buf = stream->buf;
1625         handle = stream->chan->chan->handle;
1626         client_cb = get_client_cb(buf, handle);
1627         if (!client_cb)
1628                 return -ENOSYS;
1629         return client_cb->stream_id(buf, handle, stream_id);
1630 }
1631
1632 int ustctl_get_current_timestamp(struct ustctl_consumer_stream *stream,
1633                 uint64_t *ts)
1634 {
1635         struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
1636         struct lttng_ust_lib_ring_buffer *buf;
1637         struct lttng_ust_shm_handle *handle;
1638
1639         if (!stream || !ts)
1640                 return -EINVAL;
1641         buf = stream->buf;
1642         handle = stream->chan->chan->handle;
1643         client_cb = get_client_cb(buf, handle);
1644         if (!client_cb || !client_cb->current_timestamp)
1645                 return -ENOSYS;
1646         return client_cb->current_timestamp(buf, handle, ts);
1647 }
1648
1649 #if defined(__x86_64__) || defined(__i386__)
1650
1651 int ustctl_has_perf_counters(void)
1652 {
1653         return 1;
1654 }
1655
1656 #else
1657
1658 int ustctl_has_perf_counters(void)
1659 {
1660         return 0;
1661 }
1662
1663 #endif
1664
1665 /*
1666  * Returns 0 on success, negative error value on error.
1667  */
1668 int ustctl_recv_reg_msg(int sock,
1669         enum ustctl_socket_type *type,
1670         uint32_t *major,
1671         uint32_t *minor,
1672         uint32_t *pid,
1673         uint32_t *ppid,
1674         uint32_t *uid,
1675         uint32_t *gid,
1676         uint32_t *bits_per_long,
1677         uint32_t *uint8_t_alignment,
1678         uint32_t *uint16_t_alignment,
1679         uint32_t *uint32_t_alignment,
1680         uint32_t *uint64_t_alignment,
1681         uint32_t *long_alignment,
1682         int *byte_order,
1683         char *name)
1684 {
1685         ssize_t len;
1686         struct ustctl_reg_msg reg_msg;
1687
1688         len = ustcomm_recv_unix_sock(sock, &reg_msg, sizeof(reg_msg));
1689         if (len > 0 && len != sizeof(reg_msg))
1690                 return -EIO;
1691         if (len == 0)
1692                 return -EPIPE;
1693         if (len < 0)
1694                 return len;
1695
1696         if (reg_msg.magic == LTTNG_UST_COMM_MAGIC) {
1697                 *byte_order = BYTE_ORDER == BIG_ENDIAN ?
1698                                 BIG_ENDIAN : LITTLE_ENDIAN;
1699         } else if (reg_msg.magic == bswap_32(LTTNG_UST_COMM_MAGIC)) {
1700                 *byte_order = BYTE_ORDER == BIG_ENDIAN ?
1701                                 LITTLE_ENDIAN : BIG_ENDIAN;
1702         } else {
1703                 return -LTTNG_UST_ERR_INVAL_MAGIC;
1704         }
1705         switch (reg_msg.socket_type) {
1706         case 0: *type = USTCTL_SOCKET_CMD;
1707                 break;
1708         case 1: *type = USTCTL_SOCKET_NOTIFY;
1709                 break;
1710         default:
1711                 return -LTTNG_UST_ERR_INVAL_SOCKET_TYPE;
1712         }
1713         *major = reg_msg.major;
1714         *minor = reg_msg.minor;
1715         *pid = reg_msg.pid;
1716         *ppid = reg_msg.ppid;
1717         *uid = reg_msg.uid;
1718         *gid = reg_msg.gid;
1719         *bits_per_long = reg_msg.bits_per_long;
1720         *uint8_t_alignment = reg_msg.uint8_t_alignment;
1721         *uint16_t_alignment = reg_msg.uint16_t_alignment;
1722         *uint32_t_alignment = reg_msg.uint32_t_alignment;
1723         *uint64_t_alignment = reg_msg.uint64_t_alignment;
1724         *long_alignment = reg_msg.long_alignment;
1725         memcpy(name, reg_msg.name, LTTNG_UST_ABI_PROCNAME_LEN);
1726         if (reg_msg.major != LTTNG_UST_ABI_MAJOR_VERSION) {
1727                 return -LTTNG_UST_ERR_UNSUP_MAJOR;
1728         }
1729
1730         return 0;
1731 }
1732
1733 int ustctl_recv_notify(int sock, enum ustctl_notify_cmd *notify_cmd)
1734 {
1735         struct ustcomm_notify_hdr header;
1736         ssize_t len;
1737
1738         len = ustcomm_recv_unix_sock(sock, &header, sizeof(header));
1739         if (len > 0 && len != sizeof(header))
1740                 return -EIO;
1741         if (len == 0)
1742                 return -EPIPE;
1743         if (len < 0)
1744                 return len;
1745         switch (header.notify_cmd) {
1746         case 0:
1747                 *notify_cmd = USTCTL_NOTIFY_CMD_EVENT;
1748                 break;
1749         case 1:
1750                 *notify_cmd = USTCTL_NOTIFY_CMD_CHANNEL;
1751                 break;
1752         default:
1753                 return -EINVAL;
1754         }
1755         return 0;
1756 }
1757
1758 /*
1759  * Returns 0 on success, negative error value on error.
1760  */
1761 int ustctl_recv_register_event(int sock,
1762         int *session_objd,
1763         int *channel_objd,
1764         char *event_name,
1765         int *loglevel,
1766         char **signature,
1767         size_t *nr_fields,
1768         struct ustctl_field **fields,
1769         char **model_emf_uri)
1770 {
1771         ssize_t len;
1772         struct ustcomm_notify_event_msg msg;
1773         size_t signature_len, fields_len, model_emf_uri_len;
1774         char *a_sign = NULL, *a_model_emf_uri = NULL;
1775         struct ustctl_field *a_fields = NULL;
1776
1777         len = ustcomm_recv_unix_sock(sock, &msg, sizeof(msg));
1778         if (len > 0 && len != sizeof(msg))
1779                 return -EIO;
1780         if (len == 0)
1781                 return -EPIPE;
1782         if (len < 0)
1783                 return len;
1784
1785         *session_objd = msg.session_objd;
1786         *channel_objd = msg.channel_objd;
1787         strncpy(event_name, msg.event_name, LTTNG_UST_SYM_NAME_LEN);
1788         event_name[LTTNG_UST_SYM_NAME_LEN - 1] = '\0';
1789         *loglevel = msg.loglevel;
1790         signature_len = msg.signature_len;
1791         fields_len = msg.fields_len;
1792
1793         if (fields_len % sizeof(*a_fields) != 0) {
1794                 return -EINVAL;
1795         }
1796
1797         model_emf_uri_len = msg.model_emf_uri_len;
1798
1799         /* recv signature. contains at least \0. */
1800         a_sign = zmalloc(signature_len);
1801         if (!a_sign)
1802                 return -ENOMEM;
1803         len = ustcomm_recv_unix_sock(sock, a_sign, signature_len);
1804         if (len > 0 && len != signature_len) {
1805                 len = -EIO;
1806                 goto signature_error;
1807         }
1808         if (len == 0) {
1809                 len = -EPIPE;
1810                 goto signature_error;
1811         }
1812         if (len < 0) {
1813                 goto signature_error;
1814         }
1815         /* Enforce end of string */
1816         a_sign[signature_len - 1] = '\0';
1817
1818         /* recv fields */
1819         if (fields_len) {
1820                 a_fields = zmalloc(fields_len);
1821                 if (!a_fields) {
1822                         len = -ENOMEM;
1823                         goto signature_error;
1824                 }
1825                 len = ustcomm_recv_unix_sock(sock, a_fields, fields_len);
1826                 if (len > 0 && len != fields_len) {
1827                         len = -EIO;
1828                         goto fields_error;
1829                 }
1830                 if (len == 0) {
1831                         len = -EPIPE;
1832                         goto fields_error;
1833                 }
1834                 if (len < 0) {
1835                         goto fields_error;
1836                 }
1837         }
1838
1839         if (model_emf_uri_len) {
1840                 /* recv model_emf_uri_len */
1841                 a_model_emf_uri = zmalloc(model_emf_uri_len);
1842                 if (!a_model_emf_uri) {
1843                         len = -ENOMEM;
1844                         goto fields_error;
1845                 }
1846                 len = ustcomm_recv_unix_sock(sock, a_model_emf_uri,
1847                                 model_emf_uri_len);
1848                 if (len > 0 && len != model_emf_uri_len) {
1849                         len = -EIO;
1850                         goto model_error;
1851                 }
1852                 if (len == 0) {
1853                         len = -EPIPE;
1854                         goto model_error;
1855                 }
1856                 if (len < 0) {
1857                         goto model_error;
1858                 }
1859                 /* Enforce end of string */
1860                 a_model_emf_uri[model_emf_uri_len - 1] = '\0';
1861         }
1862
1863         *signature = a_sign;
1864         *nr_fields = fields_len / sizeof(*a_fields);
1865         *fields = a_fields;
1866         *model_emf_uri = a_model_emf_uri;
1867
1868         return 0;
1869
1870 model_error:
1871         free(a_model_emf_uri);
1872 fields_error:
1873         free(a_fields);
1874 signature_error:
1875         free(a_sign);
1876         return len;
1877 }
1878
1879 /*
1880  * Returns 0 on success, negative error value on error.
1881  */
1882 int ustctl_reply_register_event(int sock,
1883         uint32_t id,
1884         int ret_code)
1885 {
1886         ssize_t len;
1887         struct {
1888                 struct ustcomm_notify_hdr header;
1889                 struct ustcomm_notify_event_reply r;
1890         } reply;
1891
1892         memset(&reply, 0, sizeof(reply));
1893         reply.header.notify_cmd = USTCTL_NOTIFY_CMD_EVENT;
1894         reply.r.ret_code = ret_code;
1895         reply.r.event_id = id;
1896         len = ustcomm_send_unix_sock(sock, &reply, sizeof(reply));
1897         if (len > 0 && len != sizeof(reply))
1898                 return -EIO;
1899         if (len < 0)
1900                 return len;
1901         return 0;
1902 }
1903
1904 /*
1905  * Returns 0 on success, negative UST or system error value on error.
1906  */
1907 int ustctl_recv_register_channel(int sock,
1908         int *session_objd,              /* session descriptor (output) */
1909         int *channel_objd,              /* channel descriptor (output) */
1910         size_t *nr_fields,
1911         struct ustctl_field **fields)
1912 {
1913         ssize_t len;
1914         struct ustcomm_notify_channel_msg msg;
1915         size_t fields_len;
1916         struct ustctl_field *a_fields;
1917
1918         len = ustcomm_recv_unix_sock(sock, &msg, sizeof(msg));
1919         if (len > 0 && len != sizeof(msg))
1920                 return -EIO;
1921         if (len == 0)
1922                 return -EPIPE;
1923         if (len < 0)
1924                 return len;
1925
1926         *session_objd = msg.session_objd;
1927         *channel_objd = msg.channel_objd;
1928         fields_len = msg.ctx_fields_len;
1929
1930         if (fields_len % sizeof(*a_fields) != 0) {
1931                 return -EINVAL;
1932         }
1933
1934         /* recv fields */
1935         if (fields_len) {
1936                 a_fields = zmalloc(fields_len);
1937                 if (!a_fields) {
1938                         len = -ENOMEM;
1939                         goto alloc_error;
1940                 }
1941                 len = ustcomm_recv_unix_sock(sock, a_fields, fields_len);
1942                 if (len > 0 && len != fields_len) {
1943                         len = -EIO;
1944                         goto fields_error;
1945                 }
1946                 if (len == 0) {
1947                         len = -EPIPE;
1948                         goto fields_error;
1949                 }
1950                 if (len < 0) {
1951                         goto fields_error;
1952                 }
1953                 *fields = a_fields;
1954         } else {
1955                 *fields = NULL;
1956         }
1957         *nr_fields = fields_len / sizeof(*a_fields);
1958         return 0;
1959
1960 fields_error:
1961         free(a_fields);
1962 alloc_error:
1963         return len;
1964 }
1965
1966 /*
1967  * Returns 0 on success, negative error value on error.
1968  */
1969 int ustctl_reply_register_channel(int sock,
1970         uint32_t chan_id,
1971         enum ustctl_channel_header header_type,
1972         int ret_code)
1973 {
1974         ssize_t len;
1975         struct {
1976                 struct ustcomm_notify_hdr header;
1977                 struct ustcomm_notify_channel_reply r;
1978         } reply;
1979
1980         memset(&reply, 0, sizeof(reply));
1981         reply.header.notify_cmd = USTCTL_NOTIFY_CMD_CHANNEL;
1982         reply.r.ret_code = ret_code;
1983         reply.r.chan_id = chan_id;
1984         switch (header_type) {
1985         case USTCTL_CHANNEL_HEADER_COMPACT:
1986                 reply.r.header_type = 1;
1987                 break;
1988         case USTCTL_CHANNEL_HEADER_LARGE:
1989                 reply.r.header_type = 2;
1990                 break;
1991         default:
1992                 reply.r.header_type = 0;
1993                 break;
1994         }
1995         len = ustcomm_send_unix_sock(sock, &reply, sizeof(reply));
1996         if (len > 0 && len != sizeof(reply))
1997                 return -EIO;
1998         if (len < 0)
1999                 return len;
2000         return 0;
2001 }
2002
2003 static __attribute__((constructor))
2004 void ustctl_init(void)
2005 {
2006         init_usterr();
2007         lttng_ust_clock_init();
2008         lttng_ring_buffer_metadata_client_init();
2009         lttng_ring_buffer_client_overwrite_init();
2010         lttng_ring_buffer_client_overwrite_rt_init();
2011         lttng_ring_buffer_client_discard_init();
2012         lttng_ring_buffer_client_discard_rt_init();
2013         lib_ringbuffer_signal_init();
2014 }
2015
2016 static __attribute__((destructor))
2017 void ustctl_exit(void)
2018 {
2019         lttng_ring_buffer_client_discard_rt_exit();
2020         lttng_ring_buffer_client_discard_exit();
2021         lttng_ring_buffer_client_overwrite_rt_exit();
2022         lttng_ring_buffer_client_overwrite_exit();
2023         lttng_ring_buffer_metadata_client_exit();
2024 }