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