include/lttng/lttng.h

   1 /*
   2  * lttng.h
   3  *
   4  * Linux Trace Toolkit Control Library Header File
   5  *
   6  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   7  *
   8  * This library is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License, version 2.1 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This library is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
  15  * for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with this library; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #ifndef _LTTNG_H
  23 #define _LTTNG_H
  24
  25 #include <limits.h>
  26 #include <netinet/in.h>
  27 #include <stdint.h>
  28 #include <sys/types.h>
  29
  30 /*
  31  * Event symbol length. Copied from LTTng kernel ABI.
  32  */
  33 #define LTTNG_SYMBOL_NAME_LEN             256
  34
  35 /*
  36  * Maximum length of a domain name. This is the limit for the total length of a
  37  * domain name specified by the RFC 1035 (https://www.ietf.org/rfc/rfc1035.txt)
  38  */
  39 #define LTTNG_MAX_DNNAME                  255
  40
  41 /*
  42  * Every lttng_event_* structure both apply to kernel event and user-space
  43  * event.
  44  */
  45
  46 /*
  47  * Domain types: the different possible tracers.
  48  */
  49 enum lttng_domain_type {
  50         LTTNG_DOMAIN_KERNEL                   = 1,
  51         LTTNG_DOMAIN_UST                      = 2,
  52
  53         /*
  54          * For now, the domains below are not implemented. However, we keep them
  55          * here in order to retain their enum values for future development. Note
  56          * that it is on the roadmap to implement them.
  57          *
  58         LTTNG_DOMAIN_UST_EXEC_NAME            = 3,
  59         LTTNG_DOMAIN_UST_PID                  = 4,
  60         LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN  = 5,
  61         */
  62 };
  63
  64 /*
  65  * Instrumentation type of tracing event.
  66  */
  67 enum lttng_event_type {
  68         LTTNG_EVENT_ALL                       = -1,
  69         LTTNG_EVENT_TRACEPOINT                = 0,
  70         LTTNG_EVENT_PROBE                     = 1,
  71         LTTNG_EVENT_FUNCTION                  = 2,
  72         LTTNG_EVENT_FUNCTION_ENTRY            = 3,
  73         LTTNG_EVENT_NOOP                      = 4,
  74         LTTNG_EVENT_SYSCALL                   = 5,
  75 };
  76
  77 /*
  78  * Loglevel information.
  79  */
  80 enum lttng_loglevel_type {
  81         LTTNG_EVENT_LOGLEVEL_ALL              = 0,
  82         LTTNG_EVENT_LOGLEVEL_RANGE            = 1,
  83         LTTNG_EVENT_LOGLEVEL_SINGLE           = 2,
  84 };
  85
  86 /*
  87  * Available loglevels.
  88  */
  89 enum lttng_loglevel {
  90         LTTNG_LOGLEVEL_EMERG                  = 0,
  91         LTTNG_LOGLEVEL_ALERT                  = 1,
  92         LTTNG_LOGLEVEL_CRIT                   = 2,
  93         LTTNG_LOGLEVEL_ERR                    = 3,
  94         LTTNG_LOGLEVEL_WARNING                = 4,
  95         LTTNG_LOGLEVEL_NOTICE                 = 5,
  96         LTTNG_LOGLEVEL_INFO                   = 6,
  97         LTTNG_LOGLEVEL_DEBUG_SYSTEM           = 7,
  98         LTTNG_LOGLEVEL_DEBUG_PROGRAM          = 8,
  99         LTTNG_LOGLEVEL_DEBUG_PROCESS          = 9,
 100         LTTNG_LOGLEVEL_DEBUG_MODULE           = 10,
 101         LTTNG_LOGLEVEL_DEBUG_UNIT             = 11,
 102         LTTNG_LOGLEVEL_DEBUG_FUNCTION         = 12,
 103         LTTNG_LOGLEVEL_DEBUG_LINE             = 13,
 104         LTTNG_LOGLEVEL_DEBUG                  = 14,
 105 };
 106
 107 /*
 108  * LTTng consumer mode
 109  */
 110 enum lttng_event_output {
 111         LTTNG_EVENT_SPLICE                    = 0,
 112         LTTNG_EVENT_MMAP                      = 1,
 113 };
 114
 115 /* Event context possible type */
 116 enum lttng_event_context_type {
 117         LTTNG_EVENT_CONTEXT_PID               = 0,
 118         LTTNG_EVENT_CONTEXT_PERF_COUNTER      = 1,
 119         LTTNG_EVENT_CONTEXT_PROCNAME          = 2,
 120         LTTNG_EVENT_CONTEXT_PRIO              = 3,
 121         LTTNG_EVENT_CONTEXT_NICE              = 4,
 122         LTTNG_EVENT_CONTEXT_VPID              = 5,
 123         LTTNG_EVENT_CONTEXT_TID               = 6,
 124         LTTNG_EVENT_CONTEXT_VTID              = 7,
 125         LTTNG_EVENT_CONTEXT_PPID              = 8,
 126         LTTNG_EVENT_CONTEXT_VPPID             = 9,
 127         LTTNG_EVENT_CONTEXT_PTHREAD_ID        = 10,
 128 };
 129
 130 enum lttng_calibrate_type {
 131         LTTNG_CALIBRATE_FUNCTION              = 0,
 132 };
 133
 134 /* Health component for the health check function. */
 135 enum lttng_health_component {
 136         LTTNG_HEALTH_CMD,
 137         LTTNG_HEALTH_APP_REG,
 138         LTTNG_HEALTH_KERNEL,
 139         LTTNG_HEALTH_CONSUMER,
 140         LTTNG_HEALTH_ALL,
 141 };
 142
 143 /* Destination type of lttng URI */
 144 enum lttng_dst_type {
 145         LTTNG_DST_IPV4                        = 1,
 146         LTTNG_DST_IPV6                        = 2,
 147         LTTNG_DST_PATH                        = 3,
 148 };
 149
 150 /* Type of lttng URI where it is a final destination or a hop */
 151 enum lttng_uri_type {
 152         LTTNG_URI_DST,  /* The URI is a final destination */
 153         /*
 154          * Hop are not supported yet but planned for a future release.
 155          *
 156         LTTNG_URI_HOP,
 157         */
 158 };
 159
 160 /* Communication stream type of a lttng URI */
 161 enum lttng_stream_type {
 162         LTTNG_STREAM_CONTROL,
 163         LTTNG_STREAM_DATA,
 164 };
 165
 166 /*
 167  * Protocol type of a lttng URI. The value 0 indicate that the proto_type field
 168  * should be ignored.
 169  */
 170 enum lttng_proto_type {
 171         LTTNG_TCP                             = 1,
 172         /*
 173          * UDP protocol is not supported for now.
 174          *
 175         LTTNG_UDP                             = 2,
 176         */
 177 };
 178
 179 /*
 180  * Structure representing an URI supported by lttng.
 181  */
 182 #define LTTNG_URI_PADDING1_LEN         16
 183 #define LTTNG_URI_PADDING2_LEN         LTTNG_SYMBOL_NAME_LEN + 32
 184 struct lttng_uri {
 185         enum lttng_dst_type dtype;
 186         enum lttng_uri_type utype;
 187         enum lttng_stream_type stype;
 188         enum lttng_proto_type proto;
 189         in_port_t port;
 190         char padding[LTTNG_URI_PADDING1_LEN];
 191         char subdir[PATH_MAX];
 192         union {
 193                 char ipv4[INET_ADDRSTRLEN];
 194                 char ipv6[INET6_ADDRSTRLEN];
 195                 char path[PATH_MAX];
 196                 char padding[LTTNG_URI_PADDING2_LEN];
 197         } dst;
 198 };
 199
 200 /*
 201  * The structures should be initialized to zero before use.
 202  */
 203 #define LTTNG_DOMAIN_PADDING1              16
 204 #define LTTNG_DOMAIN_PADDING2              LTTNG_SYMBOL_NAME_LEN + 32
 205 struct lttng_domain {
 206         enum lttng_domain_type type;
 207         char padding[LTTNG_DOMAIN_PADDING1];
 208
 209         union {
 210                 pid_t pid;
 211                 char exec_name[NAME_MAX];
 212                 char padding[LTTNG_DOMAIN_PADDING2];
 213         } attr;
 214 };
 215
 216 /*
 217  * Perf counter attributes
 218  *
 219  * The structures should be initialized to zero before use.
 220  */
 221 #define LTTNG_PERF_EVENT_PADDING1          16
 222 struct lttng_event_perf_counter_ctx {
 223         uint32_t type;
 224         uint64_t config;
 225         char name[LTTNG_SYMBOL_NAME_LEN];
 226
 227         char padding[LTTNG_PERF_EVENT_PADDING1];
 228 };
 229
 230 /*
 231  * Event/channel context
 232  *
 233  * The structures should be initialized to zero before use.
 234  */
 235 #define LTTNG_EVENT_CONTEXT_PADDING1       16
 236 #define LTTNG_EVENT_CONTEXT_PADDING2       LTTNG_SYMBOL_NAME_LEN + 32
 237 struct lttng_event_context {
 238         enum lttng_event_context_type ctx;
 239         char padding[LTTNG_EVENT_CONTEXT_PADDING1];
 240
 241         union {
 242                 struct lttng_event_perf_counter_ctx perf_counter;
 243                 char padding[LTTNG_EVENT_CONTEXT_PADDING2];
 244         } u;
 245 };
 246
 247 /*
 248  * Event probe.
 249  *
 250  * Either addr is used or symbol_name and offset.
 251  *
 252  * The structures should be initialized to zero before use.
 253  */
 254 #define LTTNG_EVENT_PROBE_PADDING1         16
 255 struct lttng_event_probe_attr {
 256         uint64_t addr;
 257
 258         uint64_t offset;
 259         char symbol_name[LTTNG_SYMBOL_NAME_LEN];
 260
 261         char padding[LTTNG_EVENT_PROBE_PADDING1];
 262 };
 263
 264 /*
 265  * Function tracer
 266  *
 267  * The structures should be initialized to zero before use.
 268  */
 269 #define LTTNG_EVENT_FUNCTION_PADDING1      16
 270 struct lttng_event_function_attr {
 271         char symbol_name[LTTNG_SYMBOL_NAME_LEN];
 272
 273         char padding[LTTNG_EVENT_FUNCTION_PADDING1];
 274 };
 275
 276 /*
 277  * Generic lttng event
 278  *
 279  * The structures should be initialized to zero before use.
 280  */
 281 #define LTTNG_EVENT_PADDING1               15
 282 #define LTTNG_EVENT_PADDING2               LTTNG_SYMBOL_NAME_LEN + 32
 283 struct lttng_event {
 284         enum lttng_event_type type;
 285         char name[LTTNG_SYMBOL_NAME_LEN];
 286
 287         enum lttng_loglevel_type loglevel_type;
 288         int loglevel;
 289
 290         int32_t enabled;        /* Does not apply: -1 */
 291         pid_t pid;
 292         unsigned char filter;   /* filter enabled ? */
 293
 294         char padding[LTTNG_EVENT_PADDING1];
 295
 296         /* Per event type configuration */
 297         union {
 298                 struct lttng_event_probe_attr probe;
 299                 struct lttng_event_function_attr ftrace;
 300
 301                 char padding[LTTNG_EVENT_PADDING2];
 302         } attr;
 303 };
 304
 305 enum lttng_event_field_type {
 306         LTTNG_EVENT_FIELD_OTHER                 = 0,
 307         LTTNG_EVENT_FIELD_INTEGER               = 1,
 308         LTTNG_EVENT_FIELD_ENUM                  = 2,
 309         LTTNG_EVENT_FIELD_FLOAT                 = 3,
 310         LTTNG_EVENT_FIELD_STRING                = 4,
 311 };
 312
 313 #define LTTNG_EVENT_FIELD_PADDING       LTTNG_SYMBOL_NAME_LEN + 32
 314 struct lttng_event_field {
 315         char field_name[LTTNG_SYMBOL_NAME_LEN];
 316         enum lttng_event_field_type type;
 317         char padding[LTTNG_EVENT_FIELD_PADDING];
 318         struct lttng_event event;
 319 };
 320
 321 /*
 322  * Tracer channel attributes. For both kernel and user-space.
 323  *
 324  * The structures should be initialized to zero before use.
 325  */
 326 #define LTTNG_CHANNEL_ATTR_PADDING1        LTTNG_SYMBOL_NAME_LEN + 32
 327 struct lttng_channel_attr {
 328         int overwrite;                      /* 1: overwrite, 0: discard */
 329         uint64_t subbuf_size;               /* bytes */
 330         uint64_t num_subbuf;                /* power of 2 */
 331         unsigned int switch_timer_interval; /* usec */
 332         unsigned int read_timer_interval;   /* usec */
 333         enum lttng_event_output output;     /* splice, mmap */
 334
 335         char padding[LTTNG_CHANNEL_ATTR_PADDING1];
 336 };
 337
 338 /*
 339  * Channel information structure. For both kernel and user-space.
 340  *
 341  * The structures should be initialized to zero before use.
 342  */
 343 #define LTTNG_CHANNEL_PADDING1             16
 344 struct lttng_channel {
 345         char name[LTTNG_SYMBOL_NAME_LEN];
 346         uint32_t enabled;
 347         struct lttng_channel_attr attr;
 348
 349         char padding[LTTNG_CHANNEL_PADDING1];
 350 };
 351
 352 #define LTTNG_CALIBRATE_PADDING1           16
 353 struct lttng_calibrate {
 354         enum lttng_calibrate_type type;
 355
 356         char padding[LTTNG_CALIBRATE_PADDING1];
 357 };
 358
 359 /*
 360  * Basic session information.
 361  *
 362  * This is an 'output data' meaning that it only comes *from* the session
 363  * daemon *to* the lttng client. It's basically a 'human' representation of
 364  * tracing entities (here a session).
 365  *
 366  * The structures should be initialized to zero before use.
 367  */
 368 #define LTTNG_SESSION_PADDING1             16
 369 struct lttng_session {
 370         char name[NAME_MAX];
 371         /* The path where traces are written */
 372         char path[PATH_MAX];
 373         uint32_t enabled;       /* enabled/started: 1, disabled/stopped: 0 */
 374
 375         char padding[LTTNG_SESSION_PADDING1];
 376 };
 377
 378 /*
 379  * Handle used as a context for commands.
 380  *
 381  * The structures should be initialized to zero before use.
 382  */
 383 #define LTTNG_HANDLE_PADDING1              16
 384 struct lttng_handle {
 385         char session_name[NAME_MAX];
 386         struct lttng_domain domain;
 387
 388         char padding[LTTNG_HANDLE_PADDING1];
 389 };
 390
 391 /*
 392  * Public LTTng control API
 393  *
 394  * For functions having an lttng domain type as parameter, if a bad value is
 395  * given, NO default is applied and an error is returned.
 396  *
 397  * On success, all functions of the API return 0 or the size of the allocated
 398  * array (in bytes).
 399  *
 400  * On error, a negative value is returned being a specific lttng-tools error
 401  * code which can be humanly interpreted with lttng_strerror(err).
 402  *
 403  * Exceptions to this are noted below.
 404  */
 405
 406 /*
 407  * Create a handle used as a context for every request made to the library.
 408  *
 409  * This handle contains the session name and lttng domain on which the command
 410  * will be executed.
 411  * The returned pointer will be NULL in case of malloc() error.
 412  */
 413 extern struct lttng_handle *lttng_create_handle(const char *session_name,
 414                 struct lttng_domain *domain);
 415
 416 /*
 417  * Destroy a handle. This will simply free(3) the data pointer returned by
 418  * lttng_create_handle(), rendering it unusable.
 419  */
 420 extern void lttng_destroy_handle(struct lttng_handle *handle);
 421
 422 /*
 423  * Create a tracing session using a name and a path where the trace will be
 424  * written.
 425  */
 426 extern int lttng_create_session(const char *name, const char *path);
 427
 428 /*
 429  * Create a tracing sessioin using a name, URIs and a consumer enable flag.
 430  * The control URI is mandatory for consumer local or network.
 431  */
 432 extern int lttng_create_session_uri(const char *name,
 433                 struct lttng_uri *ctrl_uri, struct lttng_uri *data_uri,
 434                 unsigned int enable_consumer);
 435
 436 /*
 437  * Destroy a tracing session.
 438  *
 439  * The session will not be usable anymore, tracing will be stopped for all
 440  * registered traces, and the tracing buffers will be flushed.
 441  */
 442 extern int lttng_destroy_session(const char *name);
 443
 444 /*
 445  * List all the tracing sessions.
 446  *
 447  * Return the size (number of entries) of the "lttng_session" array. Caller
 448  * must free(3).
 449  */
 450 extern int lttng_list_sessions(struct lttng_session **sessions);
 451
 452 /*
 453  * List the registered domain(s) of a session.
 454  *
 455  * Return the size (number of entries) of the "lttng_domain" array. Caller
 456  * must free(3).
 457  */
 458 extern int lttng_list_domains(const char *session_name,
 459                 struct lttng_domain **domains);
 460
 461 /*
 462  * List the channel(s) of a session.
 463  *
 464  * Return the size (number of entries) of the "lttng_channel" array. Caller
 465  * must free(3).
 466  */
 467 extern int lttng_list_channels(struct lttng_handle *handle,
 468                 struct lttng_channel **channels);
 469
 470 /*
 471  * List the event(s) of a session channel.
 472  *
 473  * Return the size (number of entries) of the "lttng_event" array.
 474  * Caller must free(3).
 475  */
 476 extern int lttng_list_events(struct lttng_handle *handle,
 477                 const char *channel_name, struct lttng_event **events);
 478
 479 /*
 480  * List the available tracepoints of a specific lttng domain.
 481  *
 482  * Return the size (number of entries) of the "lttng_event" array.
 483  * Caller must free(3).
 484  */
 485 extern int lttng_list_tracepoints(struct lttng_handle *handle,
 486                 struct lttng_event **events);
 487
 488 /*
 489  * List the available tracepoints fields of a specific lttng domain.
 490  *
 491  * Return the size (number of entries) of the "lttng_event_field" array.
 492  * Caller must free(3).
 493  */
 494 extern int lttng_list_tracepoint_fields(struct lttng_handle *handle,
 495                 struct lttng_event_field **fields);
 496
 497 /*
 498  * Check if a session daemon is alive.
 499  *
 500  * Return 1 if alive or 0 if not. On error returns a negative value.
 501  */
 502 extern int lttng_session_daemon_alive(void);
 503
 504 /*
 505  * Set the tracing group for the *current* flow of execution.
 506  *
 507  * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
 508  */
 509 extern int lttng_set_tracing_group(const char *name);
 510
 511 /*
 512  * Return a human-readable error message for an lttng-tools error code.
 513  *
 514  * Parameter MUST be a negative value or else you'll get a generic message.
 515  */
 516 extern const char *lttng_strerror(int code);
 517
 518 /*
 519  * This call registers an "outside consumer" for a session and an lttng domain.
 520  * No consumer will be spawned and all fds/commands will go through the socket
 521  * path given (socket_path).
 522  *
 523  * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
 524  * command socket. The error socket is not supported yet for roaming consumers.
 525  */
 526 extern int lttng_register_consumer(struct lttng_handle *handle,
 527                 const char *socket_path);
 528
 529 /*
 530  * Start tracing for *all* registered traces (kernel and user-space).
 531  */
 532 extern int lttng_start_tracing(const char *session_name);
 533
 534 /*
 535  * Stop tracing for *all* registered traces (kernel and user-space).
 536  */
 537 extern int lttng_stop_tracing(const char *session_name);
 538
 539 /*
 540  * Add context to event(s) for a specific channel (or for all).
 541  *
 542  * If event_name is NULL, the context is applied to all events of the channel.
 543  * If channel_name is NULL, a lookup of the event's channel is done.
 544  * If both are NULL, the context is applied to all events of all channels.
 545  */
 546 extern int lttng_add_context(struct lttng_handle *handle,
 547                 struct lttng_event_context *ctx, const char *event_name,
 548                 const char *channel_name);
 549
 550 /*
 551  * Create or enable an event (or events) for a channel.
 552  *
 553  * If the event you are trying to enable does not exist, it will be created,
 554  * else it is enabled.
 555  * If event_name is NULL, all events are enabled.
 556  * If channel_name is NULL, the default channel is used (channel0).
 557  */
 558 extern int lttng_enable_event(struct lttng_handle *handle,
 559                 struct lttng_event *ev, const char *channel_name);
 560
 561 /*
 562  * Apply a filter expression to an event.
 563  *
 564  * If event_name is NULL, the filter is applied to all events of the channel.
 565  * If channel_name is NULL, a lookup of the event's channel is done.
 566  * If both are NULL, the filter is applied to all events of all channels.
 567  */
 568 extern int lttng_set_event_filter(struct lttng_handle *handle,
 569                 const char *event_name,
 570                 const char *channel_name,
 571                 const char *filter_expression);
 572 /*
 573  * Create or enable a channel.
 574  * The channel name cannot be NULL.
 575  */
 576 extern int lttng_enable_channel(struct lttng_handle *handle,
 577                 struct lttng_channel *chan);
 578
 579 /*
 580  * Disable event(s) of a channel and domain.
 581  *
 582  * If event_name is NULL, all events are disabled.
 583  * If channel_name is NULL, the default channel is used (channel0).
 584  */
 585 extern int lttng_disable_event(struct lttng_handle *handle,
 586                 const char *name, const char *channel_name);
 587
 588 /*
 589  * Disable channel.
 590  *
 591  * The channel name cannot be NULL.
 592  */
 593 extern int lttng_disable_channel(struct lttng_handle *handle,
 594                 const char *name);
 595
 596 /*
 597  * Calibrate LTTng overhead.
 598  */
 599 extern int lttng_calibrate(struct lttng_handle *handle,
 600                 struct lttng_calibrate *calibrate);
 601
 602 /*
 603  * Set the default channel attributes for a specific domain and an allocated
 604  * lttng_channel_attr pointer.
 605  *
 606  * If either or both of the arguments are NULL, nothing happens.
 607  */
 608 extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
 609                 struct lttng_channel_attr *attr);
 610
 611 /*
 612  * Set URI for a consumer for a session and domain.
 613  *
 614  * For network streaming, both data and control stream type MUST be defined
 615  * with a specific URIs. Default port are 5342 and 5343 respectively for
 616  * control and data which uses the TCP protocol.
 617  */
 618 extern int lttng_set_consumer_uri(struct lttng_handle *handle,
 619                 struct lttng_uri *uri);
 620
 621 /*
 622  * Enable the consumer for a session and domain.
 623  */
 624 extern int lttng_enable_consumer(struct lttng_handle *handle);
 625
 626 /*
 627  * Disable consumer for a session and domain.
 628  */
 629 extern int lttng_disable_consumer(struct lttng_handle *handle);
 630
 631 /*
 632  * Check session daemon health for a specific component.
 633  *
 634  * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
 635  * the control library was not able to connect to the session daemon health
 636  * socket.
 637  *
 638  * Any other positive value is an lttcomm error which can be translate with
 639  * lttng_strerror().
 640  */
 641 extern int lttng_health_check(enum lttng_health_component c);
 642
 643 #endif /* _LTTNG_H */