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