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