| 1 | #!/usr/bin/env python3 |
| 2 | # |
| 3 | # Copyright (C) 2022 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 4 | # |
| 5 | # SPDX-License-Identifier: GPL-2.0-only |
| 6 | |
| 7 | import abc |
| 8 | import random |
| 9 | import string |
| 10 | import pathlib |
| 11 | import enum |
| 12 | from typing import Optional, Type, Union, List |
| 13 | |
| 14 | """ |
| 15 | Defines an abstract interface to control LTTng tracing. |
| 16 | |
| 17 | The various control concepts are defined by this module. You can use them with a |
| 18 | Controller to interact with a session daemon. |
| 19 | |
| 20 | This interface is not comprehensive; it currently provides a subset of the |
| 21 | control functionality that is used by tests. |
| 22 | """ |
| 23 | |
| 24 | |
| 25 | def _generate_random_string(length): |
| 26 | # type: (int) -> str |
| 27 | return "".join( |
| 28 | random.choice(string.ascii_lowercase + string.digits) for _ in range(length) |
| 29 | ) |
| 30 | |
| 31 | |
| 32 | class ContextType(abc.ABC): |
| 33 | """Base class representing a tracing context field.""" |
| 34 | |
| 35 | pass |
| 36 | |
| 37 | |
| 38 | class VpidContextType(ContextType): |
| 39 | """Application's virtual process id.""" |
| 40 | |
| 41 | pass |
| 42 | |
| 43 | |
| 44 | class VuidContextType(ContextType): |
| 45 | """Application's virtual user id.""" |
| 46 | |
| 47 | pass |
| 48 | |
| 49 | |
| 50 | class VgidContextType(ContextType): |
| 51 | """Application's virtual group id.""" |
| 52 | |
| 53 | pass |
| 54 | |
| 55 | |
| 56 | class JavaApplicationContextType(ContextType): |
| 57 | """A java application-specific context field is a piece of state which the application provides.""" |
| 58 | |
| 59 | def __init__( |
| 60 | self, |
| 61 | retriever_name, # type: str |
| 62 | field_name, # type: str |
| 63 | ): |
| 64 | self._retriever_name = retriever_name # type: str |
| 65 | self._field_name = field_name # type: str |
| 66 | |
| 67 | @property |
| 68 | def retriever_name(self): |
| 69 | # type: () -> str |
| 70 | return self._retriever_name |
| 71 | |
| 72 | @property |
| 73 | def field_name(self): |
| 74 | # type: () -> str |
| 75 | return self._field_name |
| 76 | |
| 77 | |
| 78 | @enum.unique |
| 79 | class TracingDomain(enum.Enum): |
| 80 | """Tracing domain.""" |
| 81 | |
| 82 | User = "User space tracing domain" |
| 83 | Kernel = "Linux kernel tracing domain." |
| 84 | Log4j = "Log4j tracing back-end." |
| 85 | JUL = "Java Util Logging tracing back-end." |
| 86 | Python = "Python logging module tracing back-end." |
| 87 | |
| 88 | def __repr__(self): |
| 89 | return "<%s.%s>" % (self.__class__.__name__, self.name) |
| 90 | |
| 91 | |
| 92 | @enum.unique |
| 93 | class BufferSharingPolicy(enum.Enum): |
| 94 | """Buffer sharing policy.""" |
| 95 | |
| 96 | PerUID = "Per-UID buffering" |
| 97 | PerPID = "Per-PID buffering" |
| 98 | |
| 99 | def __repr__(self): |
| 100 | return "<%s.%s>" % (self.__class__.__name__, self.name) |
| 101 | |
| 102 | |
| 103 | class EventRule(abc.ABC): |
| 104 | """Event rule base class, see LTTNG-EVENT-RULE(7).""" |
| 105 | |
| 106 | pass |
| 107 | |
| 108 | |
| 109 | class LogLevelRule: |
| 110 | pass |
| 111 | |
| 112 | |
| 113 | class LogLevelRuleAsSevereAs(LogLevelRule): |
| 114 | def __init__(self, level): |
| 115 | # type: (int) |
| 116 | self._level = level |
| 117 | |
| 118 | @property |
| 119 | def level(self): |
| 120 | # type: () -> int |
| 121 | return self._level |
| 122 | |
| 123 | |
| 124 | class LogLevelRuleExactly(LogLevelRule): |
| 125 | def __init__(self, level): |
| 126 | # type: (int) |
| 127 | self._level = level |
| 128 | |
| 129 | @property |
| 130 | def level(self): |
| 131 | # type: () -> int |
| 132 | return self._level |
| 133 | |
| 134 | |
| 135 | class TracepointEventRule(EventRule): |
| 136 | def __init__( |
| 137 | self, |
| 138 | name_pattern=None, # type: Optional[str] |
| 139 | filter_expression=None, # type: Optional[str] |
| 140 | log_level_rule=None, # type: Optional[LogLevelRule] |
| 141 | name_pattern_exclusions=None, # type: Optional[List[str]] |
| 142 | ): |
| 143 | self._name_pattern = name_pattern # type: Optional[str] |
| 144 | self._filter_expression = filter_expression # type: Optional[str] |
| 145 | self._log_level_rule = log_level_rule # type: Optional[LogLevelRule] |
| 146 | self._name_pattern_exclusions = ( |
| 147 | name_pattern_exclusions |
| 148 | ) # type: Optional[List[str]] |
| 149 | |
| 150 | @property |
| 151 | def name_pattern(self): |
| 152 | # type: () -> Optional[str] |
| 153 | return self._name_pattern |
| 154 | |
| 155 | @property |
| 156 | def filter_expression(self): |
| 157 | # type: () -> Optional[str] |
| 158 | return self._filter_expression |
| 159 | |
| 160 | @property |
| 161 | def log_level_rule(self): |
| 162 | # type: () -> Optional[LogLevelRule] |
| 163 | return self._log_level_rule |
| 164 | |
| 165 | @property |
| 166 | def name_pattern_exclusions(self): |
| 167 | # type: () -> Optional[List[str]] |
| 168 | return self._name_pattern_exclusions |
| 169 | |
| 170 | |
| 171 | class UserTracepointEventRule(TracepointEventRule): |
| 172 | def __init__( |
| 173 | self, |
| 174 | name_pattern=None, # type: Optional[str] |
| 175 | filter_expression=None, # type: Optional[str] |
| 176 | log_level_rule=None, # type: Optional[LogLevelRule] |
| 177 | name_pattern_exclusions=None, # type: Optional[List[str]] |
| 178 | ): |
| 179 | TracepointEventRule.__init__(**locals()) |
| 180 | |
| 181 | |
| 182 | class KernelTracepointEventRule(TracepointEventRule): |
| 183 | def __init__( |
| 184 | self, |
| 185 | name_pattern=None, # type: Optional[str] |
| 186 | filter_expression=None, # type: Optional[str] |
| 187 | log_level_rule=None, # type: Optional[LogLevelRule] |
| 188 | name_pattern_exclusions=None, # type: Optional[List[str]] |
| 189 | ): |
| 190 | TracepointEventRule.__init__(**locals()) |
| 191 | |
| 192 | |
| 193 | class Channel(abc.ABC): |
| 194 | """ |
| 195 | A channel is an object which is responsible for a set of ring buffers. It is |
| 196 | associated to a domain and |
| 197 | """ |
| 198 | |
| 199 | @staticmethod |
| 200 | def _generate_name(): |
| 201 | # type: () -> str |
| 202 | return "channel_{random_id}".format(random_id=_generate_random_string(8)) |
| 203 | |
| 204 | @abc.abstractmethod |
| 205 | def add_context(self, context_type): |
| 206 | # type: (ContextType) -> None |
| 207 | pass |
| 208 | |
| 209 | @property |
| 210 | @abc.abstractmethod |
| 211 | def domain(self): |
| 212 | # type: () -> TracingDomain |
| 213 | pass |
| 214 | |
| 215 | @property |
| 216 | @abc.abstractmethod |
| 217 | def name(self): |
| 218 | # type: () -> str |
| 219 | pass |
| 220 | |
| 221 | @abc.abstractmethod |
| 222 | def add_recording_rule(self, rule) -> None: |
| 223 | # type: (Type[EventRule]) -> None |
| 224 | pass |
| 225 | |
| 226 | |
| 227 | class SessionOutputLocation(abc.ABC): |
| 228 | pass |
| 229 | |
| 230 | |
| 231 | class LocalSessionOutputLocation(SessionOutputLocation): |
| 232 | def __init__(self, trace_path): |
| 233 | # type: (pathlib.Path) |
| 234 | self._path = trace_path |
| 235 | |
| 236 | @property |
| 237 | def path(self): |
| 238 | # type: () -> pathlib.Path |
| 239 | return self._path |
| 240 | |
| 241 | |
| 242 | class ProcessAttributeTracker(abc.ABC): |
| 243 | """ |
| 244 | Process attribute tracker used to filter before the evaluation of event |
| 245 | rules. |
| 246 | |
| 247 | Note that this interface is currently limited as it doesn't allow changing |
| 248 | the tracking policy. For instance, it is not possible to set the tracking |
| 249 | policy back to "all" once it has transitioned to "include set". |
| 250 | """ |
| 251 | |
| 252 | @enum.unique |
| 253 | class TrackingPolicy(enum.Enum): |
| 254 | INCLUDE_ALL = """ |
| 255 | Track all possible process attribute value of a given type (i.e. no filtering). |
| 256 | This is the default state of a process attribute tracker. |
| 257 | """ |
| 258 | EXCLUDE_ALL = "Exclude all possible process attribute values of a given type." |
| 259 | INCLUDE_SET = "Track a set of specific process attribute values." |
| 260 | |
| 261 | def __repr__(self): |
| 262 | return "<%s.%s>" % (self.__class__.__name__, self.name) |
| 263 | |
| 264 | def __init__(self, policy): |
| 265 | # type: (TrackingPolicy) |
| 266 | self._policy = policy |
| 267 | |
| 268 | @property |
| 269 | def tracking_policy(self): |
| 270 | # type: () -> TrackingPolicy |
| 271 | return self._policy |
| 272 | |
| 273 | |
| 274 | class ProcessIDProcessAttributeTracker(ProcessAttributeTracker): |
| 275 | @abc.abstractmethod |
| 276 | def track(self, pid): |
| 277 | # type: (int) -> None |
| 278 | pass |
| 279 | |
| 280 | @abc.abstractmethod |
| 281 | def untrack(self, pid): |
| 282 | # type: (int) -> None |
| 283 | pass |
| 284 | |
| 285 | |
| 286 | class VirtualProcessIDProcessAttributeTracker(ProcessAttributeTracker): |
| 287 | @abc.abstractmethod |
| 288 | def track(self, vpid): |
| 289 | # type: (int) -> None |
| 290 | pass |
| 291 | |
| 292 | @abc.abstractmethod |
| 293 | def untrack(self, vpid): |
| 294 | # type: (int) -> None |
| 295 | pass |
| 296 | |
| 297 | |
| 298 | class UserIDProcessAttributeTracker(ProcessAttributeTracker): |
| 299 | @abc.abstractmethod |
| 300 | def track(self, uid): |
| 301 | # type: (Union[int, str]) -> None |
| 302 | pass |
| 303 | |
| 304 | @abc.abstractmethod |
| 305 | def untrack(self, uid): |
| 306 | # type: (Union[int, str]) -> None |
| 307 | pass |
| 308 | |
| 309 | |
| 310 | class VirtualUserIDProcessAttributeTracker(ProcessAttributeTracker): |
| 311 | @abc.abstractmethod |
| 312 | def track(self, vuid): |
| 313 | # type: (Union[int, str]) -> None |
| 314 | pass |
| 315 | |
| 316 | @abc.abstractmethod |
| 317 | def untrack(self, vuid): |
| 318 | # type: (Union[int, str]) -> None |
| 319 | pass |
| 320 | |
| 321 | |
| 322 | class GroupIDProcessAttributeTracker(ProcessAttributeTracker): |
| 323 | @abc.abstractmethod |
| 324 | def track(self, gid): |
| 325 | # type: (Union[int, str]) -> None |
| 326 | pass |
| 327 | |
| 328 | @abc.abstractmethod |
| 329 | def untrack(self, gid): |
| 330 | # type: (Union[int, str]) -> None |
| 331 | pass |
| 332 | |
| 333 | |
| 334 | class VirtualGroupIDProcessAttributeTracker(ProcessAttributeTracker): |
| 335 | @abc.abstractmethod |
| 336 | def track(self, vgid): |
| 337 | # type: (Union[int, str]) -> None |
| 338 | pass |
| 339 | |
| 340 | @abc.abstractmethod |
| 341 | def untrack(self, vgid): |
| 342 | # type: (Union[int, str]) -> None |
| 343 | pass |
| 344 | |
| 345 | |
| 346 | class Session(abc.ABC): |
| 347 | @staticmethod |
| 348 | def _generate_name(): |
| 349 | # type: () -> str |
| 350 | return "session_{random_id}".format(random_id=_generate_random_string(8)) |
| 351 | |
| 352 | @property |
| 353 | @abc.abstractmethod |
| 354 | def name(self): |
| 355 | # type: () -> str |
| 356 | pass |
| 357 | |
| 358 | @property |
| 359 | @abc.abstractmethod |
| 360 | def output(self): |
| 361 | # type: () -> Optional[Type[SessionOutputLocation]] |
| 362 | pass |
| 363 | |
| 364 | @abc.abstractmethod |
| 365 | def add_channel( |
| 366 | self, |
| 367 | domain, |
| 368 | channel_name=None, |
| 369 | buffer_sharing_policy=BufferSharingPolicy.PerUID, |
| 370 | ): |
| 371 | # type: (TracingDomain, Optional[str], BufferSharingPolicy) -> Channel |
| 372 | """Add a channel with default attributes to the session.""" |
| 373 | pass |
| 374 | |
| 375 | @abc.abstractmethod |
| 376 | def start(self): |
| 377 | # type: () -> None |
| 378 | pass |
| 379 | |
| 380 | @abc.abstractmethod |
| 381 | def stop(self): |
| 382 | # type: () -> None |
| 383 | pass |
| 384 | |
| 385 | @abc.abstractmethod |
| 386 | def destroy(self): |
| 387 | # type: () -> None |
| 388 | pass |
| 389 | |
| 390 | @abc.abstractmethod |
| 391 | def is_active(self): |
| 392 | # type: () -> bool |
| 393 | pass |
| 394 | |
| 395 | @abc.abstractproperty |
| 396 | def kernel_pid_process_attribute_tracker(self): |
| 397 | # type: () -> Type[ProcessIDProcessAttributeTracker] |
| 398 | raise NotImplementedError |
| 399 | |
| 400 | @abc.abstractproperty |
| 401 | def kernel_vpid_process_attribute_tracker(self): |
| 402 | # type: () -> Type[VirtualProcessIDProcessAttributeTracker] |
| 403 | raise NotImplementedError |
| 404 | |
| 405 | @abc.abstractproperty |
| 406 | def user_vpid_process_attribute_tracker( |
| 407 | self, |
| 408 | ) -> Type[VirtualProcessIDProcessAttributeTracker]: |
| 409 | # type: () -> Type[VirtualProcessIDProcessAttributeTracker] |
| 410 | raise NotImplementedError |
| 411 | |
| 412 | @abc.abstractproperty |
| 413 | def kernel_gid_process_attribute_tracker(self): |
| 414 | # type: () -> Type[GroupIDProcessAttributeTracker] |
| 415 | raise NotImplementedError |
| 416 | |
| 417 | @abc.abstractproperty |
| 418 | def kernel_vgid_process_attribute_tracker(self): |
| 419 | # type: () -> Type[VirtualGroupIDProcessAttributeTracker] |
| 420 | raise NotImplementedError |
| 421 | |
| 422 | @abc.abstractproperty |
| 423 | def user_vgid_process_attribute_tracker(self): |
| 424 | # type: () -> Type[VirtualGroupIDProcessAttributeTracker] |
| 425 | raise NotImplementedError |
| 426 | |
| 427 | @abc.abstractproperty |
| 428 | def kernel_uid_process_attribute_tracker(self): |
| 429 | # type: () -> Type[UserIDProcessAttributeTracker] |
| 430 | raise NotImplementedError |
| 431 | |
| 432 | @abc.abstractproperty |
| 433 | def kernel_vuid_process_attribute_tracker(self): |
| 434 | # type: () -> Type[VirtualUserIDProcessAttributeTracker] |
| 435 | raise NotImplementedError |
| 436 | |
| 437 | @abc.abstractproperty |
| 438 | def user_vuid_process_attribute_tracker(self): |
| 439 | # type: () -> Type[VirtualUserIDProcessAttributeTracker] |
| 440 | raise NotImplementedError |
| 441 | |
| 442 | |
| 443 | class ControlException(RuntimeError): |
| 444 | """Base type for exceptions thrown by a controller.""" |
| 445 | |
| 446 | def __init__(self, msg): |
| 447 | # type: (str) |
| 448 | super().__init__(msg) |
| 449 | |
| 450 | |
| 451 | class Controller(abc.ABC): |
| 452 | """ |
| 453 | Interface of a top-level control interface. A control interface can be, for |
| 454 | example, the LTTng client or a wrapper around liblttng-ctl. It is used to |
| 455 | create and manage top-level objects of a session daemon instance. |
| 456 | """ |
| 457 | |
| 458 | @abc.abstractmethod |
| 459 | def create_session(self, name=None, output=None): |
| 460 | # type: (Optional[str], Optional[SessionOutputLocation]) -> Session |
| 461 | """ |
| 462 | Create a session with an output. Don't specify an output |
| 463 | to create a session without an output. |
| 464 | """ |
| 465 | pass |
| 466 | |
| 467 | @abc.abstractmethod |
| 468 | def start_session_by_name(self, name): |
| 469 | # type: (str) -> None |
| 470 | """ |
| 471 | Start a session by name. |
| 472 | """ |
| 473 | pass |
| 474 | |
| 475 | @abc.abstractmethod |
| 476 | def start_session_by_glob_pattern(self, pattern): |
| 477 | # type: (str) -> None |
| 478 | """ |
| 479 | Start sessions whose name matches `pattern`, see GLOB(7). |
| 480 | """ |
| 481 | pass |
| 482 | |
| 483 | @abc.abstractmethod |
| 484 | def start_sessions_all(self): |
| 485 | """ |
| 486 | Start all sessions visible to the current user. |
| 487 | """ |
| 488 | # type: () -> None |
| 489 | pass |
| 490 | |
| 491 | @abc.abstractmethod |
| 492 | def stop_session_by_name(self, name): |
| 493 | # type: (str) -> None |
| 494 | """ |
| 495 | Stop a session by name. |
| 496 | """ |
| 497 | pass |
| 498 | |
| 499 | @abc.abstractmethod |
| 500 | def stop_session_by_glob_pattern(self, pattern): |
| 501 | # type: (str) -> None |
| 502 | """ |
| 503 | Stop sessions whose name matches `pattern`, see GLOB(7). |
| 504 | """ |
| 505 | pass |
| 506 | |
| 507 | @abc.abstractmethod |
| 508 | def stop_sessions_all(self): |
| 509 | """ |
| 510 | Stop all sessions visible to the current user. |
| 511 | """ |
| 512 | # type: () -> None |
| 513 | pass |
| 514 | |
| 515 | @abc.abstractmethod |
| 516 | def destroy_session_by_name(self, name): |
| 517 | # type: (str) -> None |
| 518 | """ |
| 519 | Destroy a session by name. |
| 520 | """ |
| 521 | pass |
| 522 | |
| 523 | @abc.abstractmethod |
| 524 | def destroy_session_by_glob_pattern(self, pattern): |
| 525 | # type: (str) -> None |
| 526 | """ |
| 527 | Destroy sessions whose name matches `pattern`, see GLOB(7). |
| 528 | """ |
| 529 | pass |
| 530 | |
| 531 | @abc.abstractmethod |
| 532 | def destroy_sessions_all(self): |
| 533 | # type: () -> None |
| 534 | """ |
| 535 | Destroy all sessions visible to the current user. |
| 536 | """ |
| 537 | pass |
| 538 | |
| 539 | @abc.abstractmethod |
| 540 | def list_sessions(self): |
| 541 | # type: () -> List[Session] |
| 542 | """ |
| 543 | List all sessions visible to the current user. |
| 544 | """ |
| 545 | pass |