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