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