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               16
 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
 284         char padding[LTTNG_EVENT_PADDING1];
 285
 286         /* Per event type configuration */
 287         union {
 288                 struct lttng_event_probe_attr probe;
 289                 struct lttng_event_function_attr ftrace;
 290
 291                 char padding[LTTNG_EVENT_PADDING2];
 292         } attr;
 293 };
 294
 295 enum lttng_event_field_type {
 296         LTTNG_EVENT_FIELD_OTHER                 = 0,
 297         LTTNG_EVENT_FIELD_INTEGER               = 1,
 298         LTTNG_EVENT_FIELD_ENUM                  = 2,
 299         LTTNG_EVENT_FIELD_FLOAT                 = 3,
 300         LTTNG_EVENT_FIELD_STRING                = 4,
 301 };
 302
 303 #define LTTNG_EVENT_FIELD_PADDING       LTTNG_SYMBOL_NAME_LEN + 32
 304 struct lttng_event_field {
 305         char field_name[LTTNG_SYMBOL_NAME_LEN];
 306         enum lttng_event_field_type type;
 307         char padding[LTTNG_EVENT_FIELD_PADDING];
 308         struct lttng_event event;
 309 };
 310
 311 /*
 312  * Tracer channel attributes. For both kernel and user-space.
 313  *
 314  * The structures should be initialized to zero before use.
 315  */
 316 #define LTTNG_CHANNEL_ATTR_PADDING1        LTTNG_SYMBOL_NAME_LEN + 32
 317 struct lttng_channel_attr {
 318         int overwrite;                      /* 1: overwrite, 0: discard */
 319         uint64_t subbuf_size;               /* bytes */
 320         uint64_t num_subbuf;                /* power of 2 */
 321         unsigned int switch_timer_interval; /* usec */
 322         unsigned int read_timer_interval;   /* usec */
 323         enum lttng_event_output output;     /* splice, mmap */
 324
 325         char padding[LTTNG_CHANNEL_ATTR_PADDING1];
 326 };
 327
 328 /*
 329  * Channel information structure. For both kernel and user-space.
 330  *
 331  * The structures should be initialized to zero before use.
 332  */
 333 #define LTTNG_CHANNEL_PADDING1             16
 334 struct lttng_channel {
 335         char name[LTTNG_SYMBOL_NAME_LEN];
 336         uint32_t enabled;
 337         struct lttng_channel_attr attr;
 338
 339         char padding[LTTNG_CHANNEL_PADDING1];
 340 };
 341
 342 #define LTTNG_CALIBRATE_PADDING1           16
 343 struct lttng_calibrate {
 344         enum lttng_calibrate_type type;
 345
 346         char padding[LTTNG_CALIBRATE_PADDING1];
 347 };
 348
 349 /*
 350  * Basic session information.
 351  *
 352  * This is an 'output data' meaning that it only comes *from* the session
 353  * daemon *to* the lttng client. It's basically a 'human' representation of
 354  * tracing entities (here a session).
 355  *
 356  * The structures should be initialized to zero before use.
 357  */
 358 #define LTTNG_SESSION_PADDING1             16
 359 struct lttng_session {
 360         char name[NAME_MAX];
 361         /* The path where traces are written */
 362         char path[PATH_MAX];
 363         uint32_t enabled;       /* enabled/started: 1, disabled/stopped: 0 */
 364
 365         char padding[LTTNG_SESSION_PADDING1];
 366 };
 367
 368 /*
 369  * Handle used as a context for commands.
 370  *
 371  * The structures should be initialized to zero before use.
 372  */
 373 #define LTTNG_HANDLE_PADDING1              16
 374 struct lttng_handle {
 375         char session_name[NAME_MAX];
 376         struct lttng_domain domain;
 377
 378         char padding[LTTNG_HANDLE_PADDING1];
 379 };
 380
 381 /*
 382  * Public LTTng control API
 383  *
 384  * For functions having an lttng domain type as parameter, if a bad value is
 385  * given, NO default is applied and an error is returned.
 386  *
 387  * On success, all functions of the API return 0 or the size of the allocated
 388  * array (in bytes).
 389  *
 390  * On error, a negative value is returned being a specific lttng-tools error
 391  * code which can be humanly interpreted with lttng_strerror(err).
 392  *
 393  * Exceptions to this are noted below.
 394  */
 395
 396 /*
 397  * Create a handle used as a context for every request made to the library.
 398  *
 399  * This handle contains the session name and lttng domain on which the command
 400  * will be executed.
 401  * The returned pointer will be NULL in case of malloc() error.
 402  */
 403 extern struct lttng_handle *lttng_create_handle(const char *session_name,
 404                 struct lttng_domain *domain);
 405
 406 /*
 407  * Destroy a handle. This will simply free(3) the data pointer returned by
 408  * lttng_create_handle(), rendering it unusable.
 409  */
 410 extern void lttng_destroy_handle(struct lttng_handle *handle);
 411
 412 /*
 413  * Create a tracing session using a name and a path where the trace will be
 414  * written.
 415  */
 416 extern int lttng_create_session(const char *name, const char *path);
 417
 418 /*
 419  * Create a tracing sessioin using a name, URIs and a consumer enable flag.
 420  * The control URI is mandatory for consumer local or network.
 421  */
 422 extern int lttng_create_session_uri(const char *name,
 423                 struct lttng_uri *ctrl_uri, struct lttng_uri *data_uri,
 424                 unsigned int enable_consumer);
 425
 426 /*
 427  * Destroy a tracing session.
 428  *
 429  * The session will not be usable anymore, tracing will be stopped for all
 430  * registered traces, and the tracing buffers will be flushed.
 431  */
 432 extern int lttng_destroy_session(const char *name);
 433
 434 /*
 435  * List all the tracing sessions.
 436  *
 437  * Return the size (number of entries) of the "lttng_session" array. Caller
 438  * must free(3).
 439  */
 440 extern int lttng_list_sessions(struct lttng_session **sessions);
 441
 442 /*
 443  * List the registered domain(s) of a session.
 444  *
 445  * Return the size (number of entries) of the "lttng_domain" array. Caller
 446  * must free(3).
 447  */
 448 extern int lttng_list_domains(const char *session_name,
 449                 struct lttng_domain **domains);
 450
 451 /*
 452  * List the channel(s) of a session.
 453  *
 454  * Return the size (number of entries) of the "lttng_channel" array. Caller
 455  * must free(3).
 456  */
 457 extern int lttng_list_channels(struct lttng_handle *handle,
 458                 struct lttng_channel **channels);
 459
 460 /*
 461  * List the event(s) of a session channel.
 462  *
 463  * Return the size (number of entries) of the "lttng_event" array.
 464  * Caller must free(3).
 465  */
 466 extern int lttng_list_events(struct lttng_handle *handle,
 467                 const char *channel_name, struct lttng_event **events);
 468
 469 /*
 470  * List the available tracepoints of a specific lttng domain.
 471  *
 472  * Return the size (number of entries) of the "lttng_event" array.
 473  * Caller must free(3).
 474  */
 475 extern int lttng_list_tracepoints(struct lttng_handle *handle,
 476                 struct lttng_event **events);
 477
 478 /*
 479  * List the available tracepoints fields of a specific lttng domain.
 480  *
 481  * Return the size (number of entries) of the "lttng_event_field" array.
 482  * Caller must free(3).
 483  */
 484 extern int lttng_list_tracepoint_fields(struct lttng_handle *handle,
 485                 struct lttng_event_field **fields);
 486
 487 /*
 488  * Check if a session daemon is alive.
 489  *
 490  * Return 1 if alive or 0 if not. On error returns a negative value.
 491  */
 492 extern int lttng_session_daemon_alive(void);
 493
 494 /*
 495  * Set the tracing group for the *current* flow of execution.
 496  *
 497  * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
 498  */
 499 extern int lttng_set_tracing_group(const char *name);
 500
 501 /*
 502  * Return a human-readable error message for an lttng-tools error code.
 503  *
 504  * Parameter MUST be a negative value or else you'll get a generic message.
 505  */
 506 extern const char *lttng_strerror(int code);
 507
 508 /*
 509  * This call registers an "outside consumer" for a session and an lttng domain.
 510  * No consumer will be spawned and all fds/commands will go through the socket
 511  * path given (socket_path).
 512  *
 513  * NOTE: At the moment, if you use the liblttng-kconsumer, you can only use the
 514  * command socket. The error socket is not supported yet for roaming consumers.
 515  */
 516 extern int lttng_register_consumer(struct lttng_handle *handle,
 517                 const char *socket_path);
 518
 519 /*
 520  * Start tracing for *all* registered traces (kernel and user-space).
 521  */
 522 extern int lttng_start_tracing(const char *session_name);
 523
 524 /*
 525  * Stop tracing for *all* registered traces (kernel and user-space).
 526  */
 527 extern int lttng_stop_tracing(const char *session_name);
 528
 529 /*
 530  * Add context to event(s) for a specific channel (or for all).
 531  *
 532  * If event_name is NULL, the context is applied to all events of the channel.
 533  * If channel_name is NULL, a lookup of the event's channel is done.
 534  * If both are NULL, the context is applied to all events of all channels.
 535  */
 536 extern int lttng_add_context(struct lttng_handle *handle,
 537                 struct lttng_event_context *ctx, const char *event_name,
 538                 const char *channel_name);
 539
 540 /*
 541  * Create or enable an event (or events) for a channel.
 542  *
 543  * If the event you are trying to enable does not exist, it will be created,
 544  * else it is enabled.
 545  * If event_name is NULL, all events are enabled.
 546  * If channel_name is NULL, the default channel is used (channel0).
 547  */
 548 extern int lttng_enable_event(struct lttng_handle *handle,
 549                 struct lttng_event *ev, const char *channel_name);
 550
 551 /*
 552  * Create or enable a channel.
 553  * The channel name cannot be NULL.
 554  */
 555 extern int lttng_enable_channel(struct lttng_handle *handle,
 556                 struct lttng_channel *chan);
 557
 558 /*
 559  * Disable event(s) of a channel and domain.
 560  *
 561  * If event_name is NULL, all events are disabled.
 562  * If channel_name is NULL, the default channel is used (channel0).
 563  */
 564 extern int lttng_disable_event(struct lttng_handle *handle,
 565                 const char *name, const char *channel_name);
 566
 567 /*
 568  * Disable channel.
 569  *
 570  * The channel name cannot be NULL.
 571  */
 572 extern int lttng_disable_channel(struct lttng_handle *handle,
 573                 const char *name);
 574
 575 /*
 576  * Calibrate LTTng overhead.
 577  */
 578 extern int lttng_calibrate(struct lttng_handle *handle,
 579                 struct lttng_calibrate *calibrate);
 580
 581 /*
 582  * Set the default channel attributes for a specific domain and an allocated
 583  * lttng_channel_attr pointer.
 584  *
 585  * If either or both of the arguments are NULL, nothing happens.
 586  */
 587 extern void lttng_channel_set_default_attr(struct lttng_domain *domain,
 588                 struct lttng_channel_attr *attr);
 589
 590 /*
 591  * Set URI for a consumer for a session and domain.
 592  *
 593  * For network streaming, both data and control stream type MUST be defined
 594  * with a specific URIs. Default port are 5342 and 5343 respectively for
 595  * control and data which uses the TCP protocol.
 596  */
 597 extern int lttng_set_consumer_uri(struct lttng_handle *handle,
 598                 struct lttng_uri *uri);
 599
 600 /*
 601  * Enable the consumer for a session and domain.
 602  */
 603 extern int lttng_enable_consumer(struct lttng_handle *handle);
 604
 605 /*
 606  * Disable consumer for a session and domain.
 607  */
 608 extern int lttng_disable_consumer(struct lttng_handle *handle);
 609
 610 #endif /* _LTTNG_H */