include/lttng/ust-ctl.h

   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 #ifndef _LTTNG_UST_CTL_H
  20 #define _LTTNG_UST_CTL_H
  21
  22 #include <limits.h>
  23 #include <stddef.h>
  24 #include <stdint.h>
  25 #include <sys/types.h>
  26
  27 #include <lttng/ust-abi.h>
  28
  29 #ifndef LTTNG_PACKED
  30 #error "LTTNG_PACKED should be defined"
  31 #endif
  32
  33 #ifndef LTTNG_UST_UUID_LEN
  34 #define LTTNG_UST_UUID_LEN      16
  35 #endif
  36
  37 /* Default unix socket path */
  38 #define LTTNG_UST_SOCK_FILENAME                                 \
  39         "lttng-ust-sock-"                                       \
  40         __ust_stringify(LTTNG_UST_ABI_MAJOR_VERSION)
  41
  42 /*
  43  * Shared memory files path are automatically related to shm root, e.g.
  44  * /dev/shm under linux.
  45  */
  46 #define LTTNG_UST_WAIT_FILENAME                                 \
  47         "lttng-ust-wait-"                                       \
  48         __ust_stringify(LTTNG_UST_ABI_MAJOR_VERSION)
  49
  50 struct lttng_ust_shm_handle;
  51 struct lttng_ust_lib_ring_buffer;
  52
  53 struct ustctl_consumer_channel_attr {
  54         enum lttng_ust_chan_type type;
  55         uint64_t subbuf_size;                   /* bytes */
  56         uint64_t num_subbuf;                    /* power of 2 */
  57         int overwrite;                          /* 1: overwrite, 0: discard */
  58         unsigned int switch_timer_interval;     /* usec */
  59         unsigned int read_timer_interval;       /* usec */
  60         enum lttng_ust_output output;           /* splice, mmap */
  61         uint32_t chan_id;                       /* channel ID */
  62         unsigned char uuid[LTTNG_UST_UUID_LEN]; /* Trace session unique ID */
  63         int64_t blocking_timeout;                       /* Blocking timeout (usec) */
  64 } LTTNG_PACKED;
  65
  66 /*
  67  * API used by sessiond.
  68  */
  69
  70 struct lttng_ust_context_attr {
  71         enum lttng_ust_context_type ctx;
  72         union {
  73                 struct lttng_ust_perf_counter_ctx perf_counter;
  74                 struct {
  75                         char *provider_name;
  76                         char *ctx_name;
  77                 } app_ctx;
  78         } u;
  79 };
  80
  81 /*
  82  * Error values: all the following functions return:
  83  * >= 0: Success (LTTNG_UST_OK)
  84  * < 0: error code.
  85  */
  86 int ustctl_register_done(int sock);
  87 int ustctl_create_session(int sock);
  88 int ustctl_create_event(int sock, struct lttng_ust_event *ev,
  89                 struct lttng_ust_object_data *channel_data,
  90                 struct lttng_ust_object_data **event_data);
  91 int ustctl_add_context(int sock, struct lttng_ust_context_attr *ctx,
  92                 struct lttng_ust_object_data *obj_data,
  93                 struct lttng_ust_object_data **context_data);
  94 int ustctl_set_filter(int sock, struct lttng_ust_filter_bytecode *bytecode,
  95                 struct lttng_ust_object_data *obj_data);
  96 int ustctl_set_capture(int sock, struct lttng_ust_capture_bytecode *bytecode,
  97                 struct lttng_ust_object_data *obj_data);
  98 int ustctl_set_exclusion(int sock, struct lttng_ust_event_exclusion *exclusion,
  99                 struct lttng_ust_object_data *obj_data);
 100
 101 int ustctl_enable(int sock, struct lttng_ust_object_data *object);
 102 int ustctl_disable(int sock, struct lttng_ust_object_data *object);
 103 int ustctl_start_session(int sock, int handle);
 104 int ustctl_stop_session(int sock, int handle);
 105
 106 /*
 107  * ustctl_create_event notifier_group creates a event notifier group. It
 108  * establishes the connection with the application by providing a file
 109  * descriptor of the pipe to be used by the application when a event notifier
 110  * of that group is fired. It returns a handle to be used when creating event
 111  * notifier in that group.
 112  */
 113 int ustctl_create_event_notifier_group(int sock, int pipe_fd,
 114                 struct lttng_ust_object_data **event_notifier_group);
 115
 116 /*
 117  * ustctl_create_event notifier creates a event notifier in a event notifier
 118  * group giving a event notifier description and a event notifier group handle.
 119  * It returns a event notifier handle to be used when enabling the event
 120  * notifier, attaching filter, attaching exclusion, and disabling the event
 121  * notifier.
 122  */
 123 int ustctl_create_event_notifier(int sock,
 124                 struct lttng_ust_event_notifier *event_notifier,
 125                 struct lttng_ust_object_data *event_notifier_group,
 126                 struct lttng_ust_object_data **event_notifier_data);
 127
 128 /*
 129  * ustctl_tracepoint_list returns a tracepoint list handle, or negative
 130  * error value.
 131  */
 132 int ustctl_tracepoint_list(int sock);
 133
 134 /*
 135  * ustctl_tracepoint_list_get is used to iterate on the tp list
 136  * handle. End is iteration is reached when -LTTNG_UST_ERR_NOENT is
 137  * returned.
 138  */
 139 int ustctl_tracepoint_list_get(int sock, int tp_list_handle,
 140                 struct lttng_ust_tracepoint_iter *iter);
 141
 142 /*
 143  * ustctl_tracepoint_field_list returns a tracepoint field list handle,
 144  * or negative error value.
 145  */
 146 int ustctl_tracepoint_field_list(int sock);
 147
 148 /*
 149  * ustctl_tracepoint_field_list_get is used to iterate on the tp field
 150  * list handle. End is iteration is reached when -LTTNG_UST_ERR_NOENT is
 151  * returned.
 152  */
 153 int ustctl_tracepoint_field_list_get(int sock, int tp_field_list_handle,
 154                 struct lttng_ust_field_iter *iter);
 155
 156 int ustctl_tracer_version(int sock, struct lttng_ust_tracer_version *v);
 157 int ustctl_wait_quiescent(int sock);
 158
 159 int ustctl_sock_flush_buffer(int sock, struct lttng_ust_object_data *object);
 160
 161 int ustctl_calibrate(int sock, struct lttng_ust_calibrate *calibrate);
 162
 163 /* Release object created by members of this API. */
 164 int ustctl_release_object(int sock, struct lttng_ust_object_data *data);
 165 /* Release handle returned by create session. */
 166 int ustctl_release_handle(int sock, int handle);
 167
 168 int ustctl_recv_channel_from_consumer(int sock,
 169                 struct lttng_ust_object_data **channel_data);
 170 int ustctl_recv_stream_from_consumer(int sock,
 171                 struct lttng_ust_object_data **stream_data);
 172 int ustctl_send_channel_to_ust(int sock, int session_handle,
 173                 struct lttng_ust_object_data *channel_data);
 174 int ustctl_send_stream_to_ust(int sock,
 175                 struct lttng_ust_object_data *channel_data,
 176                 struct lttng_ust_object_data *stream_data);
 177
 178 /*
 179  * ustctl_duplicate_ust_object_data allocated a new object in "dest" if
 180  * it succeeds (returns 0). It must be released using
 181  * ustctl_release_object() and then freed with free().
 182  */
 183 int ustctl_duplicate_ust_object_data(struct lttng_ust_object_data **dest,
 184                 struct lttng_ust_object_data *src);
 185
 186 /*
 187  * API used by consumer.
 188  */
 189
 190 struct ustctl_consumer_channel;
 191 struct ustctl_consumer_stream;
 192 struct ustctl_consumer_channel_attr;
 193
 194 int ustctl_get_nr_stream_per_channel(void);
 195
 196 struct ustctl_consumer_channel *
 197         ustctl_create_channel(struct ustctl_consumer_channel_attr *attr,
 198                 const int *stream_fds, int nr_stream_fds);
 199 /*
 200  * Each stream created needs to be destroyed before calling
 201  * ustctl_destroy_channel().
 202  */
 203 void ustctl_destroy_channel(struct ustctl_consumer_channel *chan);
 204
 205 int ustctl_send_channel_to_sessiond(int sock,
 206                 struct ustctl_consumer_channel *channel);
 207 int ustctl_channel_close_wait_fd(struct ustctl_consumer_channel *consumer_chan);
 208 int ustctl_channel_close_wakeup_fd(struct ustctl_consumer_channel *consumer_chan);
 209 int ustctl_channel_get_wait_fd(struct ustctl_consumer_channel *consumer_chan);
 210 int ustctl_channel_get_wakeup_fd(struct ustctl_consumer_channel *consumer_chan);
 211
 212 int ustctl_write_metadata_to_channel(
 213                 struct ustctl_consumer_channel *channel,
 214                 const char *metadata_str,       /* NOT null-terminated */
 215                 size_t len);                    /* metadata length */
 216 ssize_t ustctl_write_one_packet_to_channel(
 217                 struct ustctl_consumer_channel *channel,
 218                 const char *metadata_str,       /* NOT null-terminated */
 219                 size_t len);                    /* metadata length */
 220
 221 /*
 222  * Send a NULL stream to finish iteration over all streams of a given
 223  * channel.
 224  */
 225 int ustctl_send_stream_to_sessiond(int sock,
 226                 struct ustctl_consumer_stream *stream);
 227 int ustctl_stream_close_wait_fd(struct ustctl_consumer_stream *stream);
 228 int ustctl_stream_close_wakeup_fd(struct ustctl_consumer_stream *stream);
 229 int ustctl_stream_get_wait_fd(struct ustctl_consumer_stream *stream);
 230 int ustctl_stream_get_wakeup_fd(struct ustctl_consumer_stream *stream);
 231
 232 /* Create/destroy stream buffers for read */
 233 struct ustctl_consumer_stream *
 234         ustctl_create_stream(struct ustctl_consumer_channel *channel,
 235                         int cpu);
 236 void ustctl_destroy_stream(struct ustctl_consumer_stream *stream);
 237
 238 /* For mmap mode, readable without "get" operation */
 239 int ustctl_get_mmap_len(struct ustctl_consumer_stream *stream,
 240                 unsigned long *len);
 241 int ustctl_get_max_subbuf_size(struct ustctl_consumer_stream *stream,
 242                 unsigned long *len);
 243
 244 /*
 245  * For mmap mode, operate on the current packet (between get/put or
 246  * get_next/put_next).
 247  */
 248 void *ustctl_get_mmap_base(struct ustctl_consumer_stream *stream);
 249 int ustctl_get_mmap_read_offset(struct ustctl_consumer_stream *stream,
 250                 unsigned long *off);
 251 int ustctl_get_subbuf_size(struct ustctl_consumer_stream *stream,
 252                 unsigned long *len);
 253 int ustctl_get_padded_subbuf_size(struct ustctl_consumer_stream *stream,
 254                 unsigned long *len);
 255 int ustctl_get_next_subbuf(struct ustctl_consumer_stream *stream);
 256 int ustctl_put_next_subbuf(struct ustctl_consumer_stream *stream);
 257
 258 /* snapshot */
 259
 260 int ustctl_snapshot(struct ustctl_consumer_stream *stream);
 261 int ustctl_snapshot_sample_positions(struct ustctl_consumer_stream *stream);
 262 int ustctl_snapshot_get_consumed(struct ustctl_consumer_stream *stream,
 263                 unsigned long *pos);
 264 int ustctl_snapshot_get_produced(struct ustctl_consumer_stream *stream,
 265                 unsigned long *pos);
 266 int ustctl_get_subbuf(struct ustctl_consumer_stream *stream,
 267                 unsigned long *pos);
 268 int ustctl_put_subbuf(struct ustctl_consumer_stream *stream);
 269
 270 void ustctl_flush_buffer(struct ustctl_consumer_stream *stream,
 271                 int producer_active);
 272 void ustctl_clear_buffer(struct ustctl_consumer_stream *stream);
 273
 274 /* index */
 275
 276 /*
 277  * Getters which need to be used on the current packet (between get/put
 278  * or get_next/put_next.
 279  */
 280
 281 int ustctl_get_timestamp_begin(struct ustctl_consumer_stream *stream,
 282                 uint64_t *timestamp_begin);
 283 int ustctl_get_timestamp_end(struct ustctl_consumer_stream *stream,
 284         uint64_t *timestamp_end);
 285 int ustctl_get_events_discarded(struct ustctl_consumer_stream *stream,
 286         uint64_t *events_discarded);
 287 int ustctl_get_content_size(struct ustctl_consumer_stream *stream,
 288         uint64_t *content_size);
 289 int ustctl_get_packet_size(struct ustctl_consumer_stream *stream,
 290         uint64_t *packet_size);
 291 int ustctl_get_sequence_number(struct ustctl_consumer_stream *stream,
 292                 uint64_t *seq);
 293
 294 /*
 295  * Getter returning state invariant for the stream, which can be used
 296  * without "get" operation.
 297  */
 298
 299 int ustctl_get_stream_id(struct ustctl_consumer_stream *stream,
 300                 uint64_t *stream_id);
 301 int ustctl_get_instance_id(struct ustctl_consumer_stream *stream,
 302                 uint64_t *id);
 303
 304 /*
 305  * Getter returning the current timestamp as perceived from the
 306  * tracer.
 307  */
 308 int ustctl_get_current_timestamp(struct ustctl_consumer_stream *stream,
 309                 uint64_t *ts);
 310
 311 /* returns whether UST has perf counters support. */
 312 int ustctl_has_perf_counters(void);
 313
 314 /* Regenerate the statedump. */
 315 int ustctl_regenerate_statedump(int sock, int handle);
 316
 317 /* event registry management */
 318
 319 enum ustctl_socket_type {
 320         USTCTL_SOCKET_CMD = 0,
 321         USTCTL_SOCKET_NOTIFY = 1,
 322 };
 323
 324 enum ustctl_notify_cmd {
 325         USTCTL_NOTIFY_CMD_EVENT = 0,
 326         USTCTL_NOTIFY_CMD_CHANNEL = 1,
 327         USTCTL_NOTIFY_CMD_ENUM = 2,
 328 };
 329
 330 enum ustctl_channel_header {
 331         USTCTL_CHANNEL_HEADER_UNKNOWN = 0,
 332         USTCTL_CHANNEL_HEADER_COMPACT = 1,
 333         USTCTL_CHANNEL_HEADER_LARGE = 2,
 334 };
 335
 336 /* event type structures */
 337
 338 enum ustctl_abstract_types {
 339         ustctl_atype_integer,
 340         ustctl_atype_enum,      /* legacy */
 341         ustctl_atype_array,     /* legacy */
 342         ustctl_atype_sequence,  /* legacy */
 343         ustctl_atype_string,
 344         ustctl_atype_float,
 345         ustctl_atype_variant,   /* legacy */
 346         ustctl_atype_struct,    /* legacy */
 347         ustctl_atype_enum_nestable,
 348         ustctl_atype_array_nestable,
 349         ustctl_atype_sequence_nestable,
 350         ustctl_atype_struct_nestable,
 351         ustctl_atype_variant_nestable,
 352         NR_USTCTL_ABSTRACT_TYPES,
 353 };
 354
 355 enum ustctl_string_encodings {
 356         ustctl_encode_none = 0,
 357         ustctl_encode_UTF8 = 1,
 358         ustctl_encode_ASCII = 2,
 359         NR_USTCTL_STRING_ENCODINGS,
 360 };
 361
 362 #define USTCTL_UST_INTEGER_TYPE_PADDING 24
 363 struct ustctl_integer_type {
 364         uint32_t size;          /* in bits */
 365         uint32_t signedness;
 366         uint32_t reverse_byte_order;
 367         uint32_t base;          /* 2, 8, 10, 16, for pretty print */
 368         int32_t encoding;       /* enum ustctl_string_encodings */
 369         uint16_t alignment;     /* in bits */
 370         char padding[USTCTL_UST_INTEGER_TYPE_PADDING];
 371 } LTTNG_PACKED;
 372
 373 #define USTCTL_UST_FLOAT_TYPE_PADDING   24
 374 struct ustctl_float_type {
 375         uint32_t exp_dig;               /* exponent digits, in bits */
 376         uint32_t mant_dig;              /* mantissa digits, in bits */
 377         uint32_t reverse_byte_order;
 378         uint16_t alignment;     /* in bits */
 379         char padding[USTCTL_UST_FLOAT_TYPE_PADDING];
 380 } LTTNG_PACKED;
 381
 382 #define USTCTL_UST_ENUM_VALUE_PADDING   15
 383 struct ustctl_enum_value {
 384         uint64_t value;
 385         uint8_t signedness;
 386         char padding[USTCTL_UST_ENUM_VALUE_PADDING];
 387 } LTTNG_PACKED;
 388
 389 enum ustctl_ust_enum_entry_options {
 390         USTCTL_UST_ENUM_ENTRY_OPTION_IS_AUTO = 1U << 0,
 391 };
 392
 393 #define USTCTL_UST_ENUM_ENTRY_PADDING   32
 394 struct ustctl_enum_entry {
 395         struct ustctl_enum_value start, end; /* start and end are inclusive */
 396         char string[LTTNG_UST_SYM_NAME_LEN];
 397         union {
 398                 struct {
 399                         uint32_t options;
 400                 } LTTNG_PACKED extra;
 401                 char padding[USTCTL_UST_ENUM_ENTRY_PADDING];
 402         } u;
 403 } LTTNG_PACKED;
 404
 405 /* legacy */
 406 #define USTCTL_UST_BASIC_TYPE_PADDING   296
 407 union _ustctl_basic_type {
 408         struct ustctl_integer_type integer;
 409         struct {
 410                 char name[LTTNG_UST_SYM_NAME_LEN];
 411                 struct ustctl_integer_type container_type;
 412                 uint64_t id;    /* enum ID in sessiond. */
 413         } enumeration;
 414         struct {
 415                 int32_t encoding;       /* enum ustctl_string_encodings */
 416         } string;
 417         struct ustctl_float_type _float;
 418         char padding[USTCTL_UST_BASIC_TYPE_PADDING];
 419 } LTTNG_PACKED;
 420
 421 /* legacy */
 422 struct ustctl_basic_type {
 423         enum ustctl_abstract_types atype;
 424         union {
 425                 union _ustctl_basic_type basic;
 426         } u;
 427 } LTTNG_PACKED;
 428
 429 /*
 430  * Padding is derived from largest member: u.legacy.sequence which
 431  * contains two basic types, each with USTCTL_UST_BASIC_TYPE_PADDING.
 432  */
 433 #define USTCTL_UST_TYPE_PADDING (2 * USTCTL_UST_BASIC_TYPE_PADDING)
 434 struct ustctl_type {
 435         enum ustctl_abstract_types atype;
 436         union {
 437                 struct ustctl_integer_type integer;
 438                 struct ustctl_float_type _float;
 439                 struct {
 440                         int32_t encoding;       /* enum ustctl_string_encodings */
 441                 } string;
 442                 struct {
 443                         char name[LTTNG_UST_SYM_NAME_LEN];
 444                         uint64_t id;    /* enum ID in sessiond. */
 445                         /* container_type follows after this struct ustctl_field. */
 446                 } enum_nestable;
 447                 struct {
 448                         uint32_t length;                /* num. elems. */
 449                         uint32_t alignment;
 450                         /* elem_type follows after this struct ustctl_field. */
 451                 } array_nestable;
 452                 struct {
 453                         char length_name[LTTNG_UST_SYM_NAME_LEN];
 454                         uint32_t alignment;             /* Alignment before elements. */
 455                         /* elem_type follows after the length_type. */
 456                 } sequence_nestable;
 457                 struct {
 458                         uint32_t nr_fields;
 459                         uint32_t alignment;
 460                         /* Followed by nr_fields struct ustctl_field. */
 461                 } struct_nestable;
 462                 struct {
 463                         uint32_t nr_choices;
 464                         char tag_name[LTTNG_UST_SYM_NAME_LEN];
 465                         uint32_t alignment;
 466                         /* Followed by nr_choices struct ustctl_field. */
 467                 } variant_nestable;
 468
 469                 /* Legacy ABI */
 470                 union {
 471                         union _ustctl_basic_type basic;
 472                         struct {
 473                                 struct ustctl_basic_type elem_type;
 474                                 uint32_t length;                /* num. elems. */
 475                         } array;
 476                         struct {
 477                                 struct ustctl_basic_type length_type;
 478                                 struct ustctl_basic_type elem_type;
 479                         } sequence;
 480                         struct {
 481                                 uint32_t nr_fields;
 482                                 /* Followed by nr_fields struct ustctl_field. */
 483                         } _struct;
 484                         struct {
 485                                 uint32_t nr_choices;
 486                                 char tag_name[LTTNG_UST_SYM_NAME_LEN];
 487                                 /* Followed by nr_choices struct ustctl_field. */
 488                         } variant;
 489                 } legacy;
 490                 char padding[USTCTL_UST_TYPE_PADDING];
 491         } u;
 492 } LTTNG_PACKED;
 493
 494 #define USTCTL_UST_FIELD_PADDING        28
 495 struct ustctl_field {
 496         char name[LTTNG_UST_SYM_NAME_LEN];
 497         struct ustctl_type type;
 498         char padding[USTCTL_UST_FIELD_PADDING];
 499 } LTTNG_PACKED;
 500
 501 /*
 502  * Returns 0 on success, negative error value on error.
 503  * If an error other than -LTTNG_UST_ERR_UNSUP_MAJOR is returned,
 504  * the output fields are not populated.
 505  */
 506 int ustctl_recv_reg_msg(int sock,
 507         enum ustctl_socket_type *type,
 508         uint32_t *major,
 509         uint32_t *minor,
 510         uint32_t *pid,
 511         uint32_t *ppid,
 512         uint32_t *uid,
 513         uint32_t *gid,
 514         uint32_t *bits_per_long,
 515         uint32_t *uint8_t_alignment,
 516         uint32_t *uint16_t_alignment,
 517         uint32_t *uint32_t_alignment,
 518         uint32_t *uint64_t_alignment,
 519         uint32_t *long_alignment,
 520         int *byte_order,
 521         char *name);    /* size LTTNG_UST_ABI_PROCNAME_LEN */
 522
 523 /*
 524  * Returns 0 on success, negative UST or system error value on error.
 525  * Receive the notification command. The "notify_cmd" can then be used
 526  * by the caller to find out which ustctl_recv_* function should be
 527  * called to receive the notification, and which ustctl_reply_* is
 528  * appropriate.
 529  */
 530 int ustctl_recv_notify(int sock, enum ustctl_notify_cmd *notify_cmd);
 531
 532 /*
 533  * Returns 0 on success, negative UST or system error value on error.
 534  */
 535 int ustctl_recv_register_event(int sock,
 536         int *session_objd,              /* session descriptor (output) */
 537         int *channel_objd,              /* channel descriptor (output) */
 538         char *event_name,               /*
 539                                          * event name (output,
 540                                          * size LTTNG_UST_SYM_NAME_LEN)
 541                                          */
 542         int *loglevel,
 543         char **signature,               /*
 544                                          * event signature
 545                                          * (output, dynamically
 546                                          * allocated, must be free(3)'d
 547                                          * by the caller if function
 548                                          * returns success.)
 549                                          */
 550         size_t *nr_fields,
 551         struct ustctl_field **fields,
 552         char **model_emf_uri);
 553
 554 /*
 555  * Returns 0 on success, negative error value on error.
 556  */
 557 int ustctl_reply_register_event(int sock,
 558         uint32_t id,                    /* event id (input) */
 559         int ret_code);                  /* return code. 0 ok, negative error */
 560
 561 /*
 562  * Returns 0 on success, negative UST or system error value on error.
 563  */
 564 int ustctl_recv_register_enum(int sock,
 565         int *session_objd,
 566         char *enum_name,
 567         struct ustctl_enum_entry **entries,
 568         size_t *nr_entries);
 569
 570 /*
 571  * Returns 0 on success, negative error value on error.
 572  */
 573 int ustctl_reply_register_enum(int sock,
 574         uint64_t id,                    /* enum id (input) */
 575         int ret_code);
 576
 577 /*
 578  * Returns 0 on success, negative UST or system error value on error.
 579  */
 580 int ustctl_recv_register_channel(int sock,
 581         int *session_objd,              /* session descriptor (output) */
 582         int *channel_objd,              /* channel descriptor (output) */
 583         size_t *nr_fields,              /* context fields */
 584         struct ustctl_field **fields);
 585
 586 /*
 587  * Returns 0 on success, negative error value on error.
 588  */
 589 int ustctl_reply_register_channel(int sock,
 590         uint32_t chan_id,
 591         enum ustctl_channel_header header_type,
 592         int ret_code);                  /* return code. 0 ok, negative error */
 593
 594 #endif /* _LTTNG_UST_CTL_H */