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_MANAGE,
 138         LTTNG_HEALTH_APP_REG,
 139         LTTNG_HEALTH_KERNEL,
 140         LTTNG_HEALTH_CONSUMER,
 141         LTTNG_HEALTH_ALL,
 142 };
 143
 144 /* Destination type of lttng URI */
 145 enum lttng_dst_type {
 146         LTTNG_DST_IPV4                        = 1,
 147         LTTNG_DST_IPV6                        = 2,
 148         LTTNG_DST_PATH                        = 3,
 149 };
 150
 151 /* Type of lttng URI where it is a final destination or a hop */
 152 enum lttng_uri_type {
 153         LTTNG_URI_DST,  /* The URI is a final destination */
 154         /*
 155          * Hop are not supported yet but planned for a future release.
 156          *
 157         LTTNG_URI_HOP,
 158         */
 159 };
 160
 161 /* Communication stream type of a lttng URI */
 162 enum lttng_stream_type {
 163         LTTNG_STREAM_CONTROL,
 164         LTTNG_STREAM_DATA,
 165 };
 166
 167 /*
 168  * Protocol type of a lttng URI. The value 0 indicate that the proto_type field
 169  * should be ignored.
 170  */
 171 enum lttng_proto_type {
 172         LTTNG_TCP                             = 1,
 173         /*
 174          * UDP protocol is not supported for now.
 175          *
 176         LTTNG_UDP                             = 2,
 177         */
 178 };
 179
 180 /*
 181  * Structure representing an URI supported by lttng.
 182  */
 183 #define LTTNG_URI_PADDING1_LEN         16
 184 #define LTTNG_URI_PADDING2_LEN         LTTNG_SYMBOL_NAME_LEN + 32
 185 struct lttng_uri {
 186         enum lttng_dst_type dtype;
 187         enum lttng_uri_type utype;
 188         enum lttng_stream_type stype;
 189         enum lttng_proto_type proto;
 190         in_port_t port;
 191         char padding[LTTNG_URI_PADDING1_LEN];
 192         char subdir[PATH_MAX];
 193         union {
 194                 char ipv4[INET_ADDRSTRLEN];
 195                 char ipv6[INET6_ADDRSTRLEN];
 196                 char path[PATH_MAX];
 197                 char padding[LTTNG_URI_PADDING2_LEN];
 198         } dst;
 199 };
 200
 201 /*
 202  * The structures should be initialized to zero before use.
 203  */
 204 #define LTTNG_DOMAIN_PADDING1              16
 205 #define LTTNG_DOMAIN_PADDING2              LTTNG_SYMBOL_NAME_LEN + 32
 206 struct lttng_domain {
 207         enum lttng_domain_type type;
 208         char padding[LTTNG_DOMAIN_PADDING1];
 209
 210         union {
 211                 pid_t pid;
 212                 char exec_name[NAME_MAX];
 213                 char padding[LTTNG_DOMAIN_PADDING2];
 214         } attr;
 215 };
 216
 217 /*
 218  * Perf counter attributes
 219  *
 220  * The structures should be initialized to zero before use.
 221  */
 222 #define LTTNG_PERF_EVENT_PADDING1          16
 223 struct lttng_event_perf_counter_ctx {
 224         uint32_t type;
 225         uint64_t config;
 226         char name[LTTNG_SYMBOL_NAME_LEN];
 227
 228         char padding[LTTNG_PERF_EVENT_PADDING1];
 229 };
 230
 231 /*
 232  * Event/channel context
 233  *
 234  * The structures should be initialized to zero before use.
 235  */
 236 #define LTTNG_EVENT_CONTEXT_PADDING1       16
 237 #define LTTNG_EVENT_CONTEXT_PADDING2       LTTNG_SYMBOL_NAME_LEN + 32
 238 struct lttng_event_context {
 239         enum lttng_event_context_type ctx;
 240         char padding[LTTNG_EVENT_CONTEXT_PADDING1];
 241
 242         union {
 243                 struct lttng_event_perf_counter_ctx perf_counter;
 244                 char padding[LTTNG_EVENT_CONTEXT_PADDING2];
 245         } u;
 246 };
 247
 248 /*
 249  * Event probe.
 250  *
 251  * Either addr is used or symbol_name and offset.
 252  *
 253  * The structures should be initialized to zero before use.
 254  */
 255 #define LTTNG_EVENT_PROBE_PADDING1         16
 256 struct lttng_event_probe_attr {
 257         uint64_t addr;
 258
 259         uint64_t offset;
 260         char symbol_name[LTTNG_SYMBOL_NAME_LEN];
 261
 262         char padding[LTTNG_EVENT_PROBE_PADDING1];
 263 };
 264
 265 /*
 266  * Function tracer
 267  *
 268  * The structures should be initialized to zero before use.
 269  */
 270 #define LTTNG_EVENT_FUNCTION_PADDING1      16
 271 struct lttng_event_function_attr {
 272         char symbol_name[LTTNG_SYMBOL_NAME_LEN];
 273
 274         char padding[LTTNG_EVENT_FUNCTION_PADDING1];
 275 };
 276
 277 /*
 278  * Generic lttng event
 279  *
 280  * The structures should be initialized to zero before use.
 281  */
 282 #define LTTNG_EVENT_PADDING1               15
 283 #define LTTNG_EVENT_PADDING2               LTTNG_SYMBOL_NAME_LEN + 32
 284 struct lttng_event {
 285         enum lttng_event_type type;
 286         char name[LTTNG_SYMBOL_NAME_LEN];
 287
 288         enum lttng_loglevel_type loglevel_type;
 289         int loglevel;
 290
 291         int32_t enabled;        /* Does not apply: -1 */
 292         pid_t pid;
 293         unsigned char filter;   /* filter enabled ? */
 294
 295         char padding[LTTNG_EVENT_PADDING1];
 296
 297         /* Per event type configuration */
 298         union {
 299                 struct lttng_event_probe_attr probe;
 300                 struct lttng_event_function_attr ftrace;
 301
 302                 char padding[LTTNG_EVENT_PADDING2];
 303         } attr;
 304 };
 305
 306 enum lttng_event_field_type {
 307         LTTNG_EVENT_FIELD_OTHER                 = 0,
 308         LTTNG_EVENT_FIELD_INTEGER               = 1,
 309         LTTNG_EVENT_FIELD_ENUM                  = 2,
 310         LTTNG_EVENT_FIELD_FLOAT                 = 3,
 311         LTTNG_EVENT_FIELD_STRING                = 4,
 312 };
 313
 314 #define LTTNG_EVENT_FIELD_PADDING       LTTNG_SYMBOL_NAME_LEN + 32
 315 struct lttng_event_field {
 316         char field_name[LTTNG_SYMBOL_NAME_LEN];
 317         enum lttng_event_field_type type;
 318         char padding[LTTNG_EVENT_FIELD_PADDING];
 319         struct lttng_event event;
 320 };
 321
 322 /*
 323  * Tracer channel attributes. For both kernel and user-space.
 324  *
 325  * The structures should be initialized to zero before use.
 326  */
 327 #define LTTNG_CHANNEL_ATTR_PADDING1        LTTNG_SYMBOL_NAME_LEN + 32
 328 struct lttng_channel_attr {
 329         int overwrite;                      /* 1: overwrite, 0: discard */
 330         uint64_t subbuf_size;               /* bytes */
 331         uint64_t num_subbuf;                /* power of 2 */
 332         unsigned int switch_timer_interval; /* usec */
 333         unsigned int read_timer_interval;   /* usec */
 334         enum lttng_event_output output;     /* splice, mmap */
 335
 336         char padding[LTTNG_CHANNEL_ATTR_PADDING1];
 337 };
 338
 339 /*
 340  * Channel information structure. For both kernel and user-space.
 341  *
 342  * The structures should be initialized to zero before use.
 343  */
 344 #define LTTNG_CHANNEL_PADDING1             16
 345 struct lttng_channel {
 346         char name[LTTNG_SYMBOL_NAME_LEN];
 347         uint32_t enabled;
 348         struct lttng_channel_attr attr;
 349
 350         char padding[LTTNG_CHANNEL_PADDING1];
 351 };
 352
 353 #define LTTNG_CALIBRATE_PADDING1           16
 354 struct lttng_calibrate {
 355         enum lttng_calibrate_type type;
 356
 357         char padding[LTTNG_CALIBRATE_PADDING1];
 358 };
 359
 360 /*
 361  * Basic session information.
 362  *
 363  * This is an 'output data' meaning that it only comes *from* the session
 364  * daemon *to* the lttng client. It's basically a 'human' representation of
 365  * tracing entities (here a session).
 366  *
 367  * The structures should be initialized to zero before use.
 368  */
 369 #define LTTNG_SESSION_PADDING1             16
 370 struct lttng_session {
 371         char name[NAME_MAX];
 372         /* The path where traces are written */
 373         char path[PATH_MAX];
 374         uint32_t enabled;       /* enabled/started: 1, disabled/stopped: 0 */
 375
 376         char padding[LTTNG_SESSION_PADDING1];
 377 };
 378
 379 /*
 380  * Handle used as a context for commands.
 381  *
 382  * The structures should be initialized to zero before use.
 383  */
 384 #define LTTNG_HANDLE_PADDING1              16
 385 struct lttng_handle {
 386         char session_name[NAME_MAX];
 387         struct lttng_domain domain;
 388
 389         char padding[LTTNG_HANDLE_PADDING1];
 390 };
 391
 392 /*
 393  * Public LTTng control API
 394  *
 395  * For functions having an lttng domain type as parameter, if a bad value is
 396  * given, NO default is applied and an error is returned.
 397  *
 398  * On success, all functions of the API return 0 or the size of the allocated
 399  * array (in bytes).
 400  *
 401  * On error, a negative value is returned being a specific lttng-tools error
 402  * code which can be humanly interpreted with lttng_strerror(err).
 403  *
 404  * Exceptions to this are noted below.
 405  */
 406
 407 /*
 408  * Create a handle used as a context for every request made to the library.
 409  *
 410  * This handle contains the session name and lttng domain on which the command
 411  * will be executed.
 412  * The returned pointer will be NULL in case of malloc() error.
 413  */
 414 extern struct lttng_handle *lttng_create_handle(const char *session_name,
 415                 struct lttng_domain *domain);
 416
 417 /*
 418  * Destroy a handle. This will simply free(3) the data pointer returned by
 419  * lttng_create_handle(), rendering it unusable.
 420  */
 421 extern void lttng_destroy_handle(struct lttng_handle *handle);
 422
 423 /*
 424  * Create a tracing session using a name and a path where the trace will be
 425  * written.
 426  */
 427 extern int lttng_create_session(const char *name, const char *path);
 428
 429 /*
 430  * Create a tracing sessioin using a name, URIs and a consumer enable flag.
 431  * The control URI is mandatory for consumer local or network.
 432  */
 433 extern int lttng_create_session_uri(const char *name,
 434                 struct lttng_uri *ctrl_uri, struct lttng_uri *data_uri,
 435                 unsigned int enable_consumer);
 436
 437 /*
 438  * Destroy a tracing session.
 439  *
 440  * The session will not be usable anymore, tracing will be stopped for all
 441  * registered traces, and the tracing buffers will be flushed.
 442  */
 443 extern int lttng_destroy_session(const char *name);
 444
 445 /*
 446  * List all the tracing sessions.
 447  *
 448  * Return the size (number of entries) of the "lttng_session" array. Caller
 449  * must free(3).
 450  */
 451 extern int lttng_list_sessions(struct lttng_session **sessions);
 452
 453 /*
 454  * List the registered domain(s) of a session.
 455  *
 456  * Return the size (number of entries) of the "lttng_domain" array. Caller
 457  * must free(3).
 458  */
 459 extern int lttng_list_domains(const char *session_name,
 460                 struct lttng_domain **domains);
 461
 462 /*
 463  * List the channel(s) of a session.
 464  *
 465  * Return the size (number of entries) of the "lttng_channel" array. Caller
 466  * must free(3).
 467  */
 468 extern int lttng_list_channels(struct lttng_handle *handle,
 469                 struct lttng_channel **channels);
 470
 471 /*
 472  * List the event(s) of a session channel.
 473  *
 474  * Return the size (number of entries) of the "lttng_event" array.
 475  * Caller must free(3).
 476  */
 477 extern int lttng_list_events(struct lttng_handle *handle,
 478                 const char *channel_name, struct lttng_event **events);
 479
 480 /*
 481  * List the available tracepoints of a specific lttng domain.
 482  *
 483  * Return the size (number of entries) of the "lttng_event" array.
 484  * Caller must free(3).
 485  */
 486 extern int lttng_list_tracepoints(struct lttng_handle *handle,
 487                 struct lttng_event **events);
 488
 489 /*
 490  * List the available tracepoints fields of a specific lttng domain.
 491  *
 492  * Return the size (number of entries) of the "lttng_event_field" array.
 493  * Caller must free(3).
 494  */
 495 extern int lttng_list_tracepoint_fields(struct lttng_handle *handle,
 496                 struct lttng_event_field **fields);
 497
 498 /*
 499  * Check if a session daemon is alive.
 500  *
 501  * Return 1 if alive or 0 if not. On error returns a negative value.
 502  */
 503 extern int lttng_session_daemon_alive(void);
 504
 505 /*
 506  * Set the tracing group for the *current* flow of execution.
 507  *
 508  * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
 509  */
 510 extern int lttng_set_tracing_group(const char *name);
 511
 512 /*
 513  * Return a human-readable error message for an lttng-tools error code.
 514  *
 515  * Parameter MUST be a negative value or else you'll get a generic message.
 516  */
 517 extern const char *lttng_strerror(int code);
 518
 519 /*
 520  * This call registers an "outside consumer" for a session and an lttng domain.
 521  * No consumer will be spawned and all fds/commands will go through the socket
 522  * path given (socket_path).
 523  *
 524  * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
 525  * command socket. The error socket is not supported yet for roaming consumers.
 526  */
 527 extern int lttng_register_consumer(struct lttng_handle *handle,
 528                 const char *socket_path);
 529
 530 /*
 531  * Start tracing for *all* registered traces (kernel and user-space).
 532  */
 533 extern int lttng_start_tracing(const char *session_name);
 534
 535 /*
 536  * Stop tracing for *all* registered traces (kernel and user-space).
 537  */
 538 extern int lttng_stop_tracing(const char *session_name);
 539
 540 /*
 541  * Add context to event(s) for a specific channel (or for all).
 542  *
 543  * If event_name is NULL, the context is applied to all events of the channel.
 544  * If channel_name is NULL, a lookup of the event's channel is done.
 545  * If both are NULL, the context is applied to all events of all channels.
 546  */
 547 extern int lttng_add_context(struct lttng_handle *handle,
 548                 struct lttng_event_context *ctx, const char *event_name,
 549                 const char *channel_name);
 550
 551 /*
 552  * Create or enable an event (or events) for a channel.
 553  *
 554  * If the event you are trying to enable does not exist, it will be created,
 555  * else it is enabled.
 556  * If event_name is NULL, all events are enabled.
 557  * If channel_name is NULL, the default channel is used (channel0).
 558  */
 559 extern int lttng_enable_event(struct lttng_handle *handle,
 560                 struct lttng_event *ev, const char *channel_name);
 561
 562 /*
 563  * Apply a filter expression to an event.
 564  *
 565  * If event_name is NULL, the filter is applied to all events of the channel.
 566  * If channel_name is NULL, a lookup of the event's channel is done.
 567  * If both are NULL, the filter is applied to all events of all channels.
 568  */
 569 extern int lttng_set_event_filter(struct lttng_handle *handle,
 570                 const char *event_name,
 571                 const char *channel_name,
 572                 const char *filter_expression);
 573 /*
 574  * Create or enable a channel.
 575  * The channel name cannot be NULL.
 576  */
 577 extern int lttng_enable_channel(struct lttng_handle *handle,
 578                 struct lttng_channel *chan);
 579
 580 /*
 581  * Disable event(s) of a channel and domain.
 582  *
 583  * If event_name is NULL, all events are disabled.
 584  * If channel_name is NULL, the default channel is used (channel0).
 585  */
 586 extern int lttng_disable_event(struct lttng_handle *handle,
 587                 const char *name, const char *channel_name);
 588
 589 /*
 590  * Disable channel.
 591  *
 592  * The channel name cannot be NULL.
 593  */
 594 extern int lttng_disable_channel(struct lttng_handle *handle,
 595                 const char *name);
 596
 597 /*
 598  * Calibrate LTTng overhead.
 599  */
 600 extern int lttng_calibrate(struct lttng_handle *handle,
 601                 struct lttng_calibrate *calibrate);
 602
 603 /*
 604  * Set the default channel attributes for a specific domain and an allocated
 605  * lttng_channel_attr pointer.
 606  *
 607  * If either or both of the arguments are NULL, nothing happens.
 608  */
 609 extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
 610                 struct lttng_channel_attr *attr);
 611
 612 /*
 613  * Set URI for a consumer for a session and domain.
 614  *
 615  * For network streaming, both data and control stream type MUST be defined
 616  * with a specific URIs. Default port are 5342 and 5343 respectively for
 617  * control and data which uses the TCP protocol.
 618  */
 619 extern int lttng_set_consumer_uri(struct lttng_handle *handle,
 620                 struct lttng_uri *uri);
 621
 622 /*
 623  * Enable the consumer for a session and domain.
 624  */
 625 extern int lttng_enable_consumer(struct lttng_handle *handle);
 626
 627 /*
 628  * Disable consumer for a session and domain.
 629  */
 630 extern int lttng_disable_consumer(struct lttng_handle *handle);
 631
 632 /*
 633  * Check session daemon health for a specific component.
 634  *
 635  * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
 636  * the control library was not able to connect to the session daemon health
 637  * socket.
 638  *
 639  * Any other positive value is an lttcomm error which can be translate with
 640  * lttng_strerror().
 641  */
 642 extern int lttng_health_check(enum lttng_health_component c);
 643
 644 #endif /* _LTTNG_H */