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