| 1 | /* |
| 2 | * Copyright (C) 2013 David Goulet <dgoulet@efficios.com> |
| 3 | * Copyright (C) 2022 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 4 | * |
| 5 | * SPDX-License-Identifier: GPL-2.0-only |
| 6 | * |
| 7 | */ |
| 8 | |
| 9 | #ifndef LTTNG_UST_REGISTRY_H |
| 10 | #define LTTNG_UST_REGISTRY_H |
| 11 | |
| 12 | #include "event-class.hpp" |
| 13 | #include "field.hpp" |
| 14 | #include "lttng-ust-ctl.hpp" |
| 15 | #include "session.hpp" |
| 16 | #include "stream-class.hpp" |
| 17 | #include "trace-class.hpp" |
| 18 | #include "ust-clock-class.hpp" |
| 19 | #include "ust-registry-channel.hpp" |
| 20 | #include "ust-registry-event.hpp" |
| 21 | |
| 22 | #include <common/format.hpp> |
| 23 | #include <common/hashtable/hashtable.hpp> |
| 24 | #include <common/locked-reference.hpp> |
| 25 | #include <common/urcu.hpp> |
| 26 | #include <common/uuid.hpp> |
| 27 | |
| 28 | #include <lttng/domain.h> |
| 29 | |
| 30 | #include <ctime> |
| 31 | #include <memory> |
| 32 | #include <pthread.h> |
| 33 | #include <stdint.h> |
| 34 | #include <string> |
| 35 | #include <type_traits> |
| 36 | |
| 37 | #define CTF_SPEC_MAJOR 1 |
| 38 | #define CTF_SPEC_MINOR 8 |
| 39 | |
| 40 | struct ust_app; |
| 41 | class ust_registry_session; |
| 42 | |
| 43 | namespace lttng { |
| 44 | namespace sessiond { |
| 45 | namespace details { |
| 46 | void locked_ust_registry_session_release(ust_registry_session *session); |
| 47 | } /* namespace details */ |
| 48 | } /* namespace sessiond */ |
| 49 | } /* namespace lttng */ |
| 50 | |
| 51 | class ust_registry_session : public lttng::sessiond::trace::trace_class { |
| 52 | public: |
| 53 | using locked_ptr = std::unique_ptr<ust_registry_session, |
| 54 | lttng::details::create_unique_class<ust_registry_session, |
| 55 | lttng::sessiond::details::locked_ust_registry_session_release>:: |
| 56 | deleter>; |
| 57 | |
| 58 | virtual lttng_buffer_type get_buffering_scheme() const noexcept = 0; |
| 59 | locked_ptr lock(); |
| 60 | |
| 61 | void add_channel(uint64_t channel_key); |
| 62 | lttng::sessiond::ust::registry_channel& get_channel(uint64_t channel_key) const; |
| 63 | void remove_channel(uint64_t channel_key, bool notify); |
| 64 | |
| 65 | void regenerate_metadata(); |
| 66 | virtual ~ust_registry_session(); |
| 67 | |
| 68 | /* |
| 69 | * With multiple writers and readers, use this lock to access |
| 70 | * the registry. Can nest within the ust app session lock. |
| 71 | * Also acts as a registry serialization lock. Used by registry |
| 72 | * readers to serialize the registry information sent from the |
| 73 | * sessiond to the consumerd. |
| 74 | * The consumer socket lock nests within this lock. |
| 75 | */ |
| 76 | mutable pthread_mutex_t _lock; |
| 77 | /* Next channel ID available for a newly registered channel. */ |
| 78 | uint32_t _next_channel_id = 0; |
| 79 | /* Once this value reaches UINT32_MAX, no more id can be allocated. */ |
| 80 | uint32_t _used_channel_id = 0; |
| 81 | /* Next enumeration ID available. */ |
| 82 | uint64_t _next_enum_id = 0; |
| 83 | |
| 84 | /* Generated metadata. */ |
| 85 | char *_metadata = nullptr; /* NOT null-terminated ! Use memcpy. */ |
| 86 | size_t _metadata_len = 0, _metadata_alloc_len = 0; |
| 87 | /* Length of bytes sent to the consumer. */ |
| 88 | size_t _metadata_len_sent = 0; |
| 89 | /* Current version of the metadata. */ |
| 90 | uint64_t _metadata_version = 0; |
| 91 | |
| 92 | /* |
| 93 | * Those fields are only used when a session is created with |
| 94 | * the --shm-path option. In this case, the metadata is output |
| 95 | * twice: once to the consumer, as ususal, but a second time |
| 96 | * also in the shm path directly. This is done so that a copy |
| 97 | * of the metadata that is as fresh as possible is available |
| 98 | * on the event of a crash. |
| 99 | * |
| 100 | * root_shm_path contains the shm-path provided by the user, along with |
| 101 | * the session's name and timestamp: |
| 102 | * e.g. /tmp/my_shm/my_session-20180612-135822 |
| 103 | * |
| 104 | * shm_path contains the full path of the memory buffers: |
| 105 | * e.g. /tmp/my_shm/my_session-20180612-135822/ust/uid/1000/64-bit |
| 106 | * |
| 107 | * metadata_path contains the full path to the metadata file that |
| 108 | * is kept for the "crash buffer" extraction: |
| 109 | * e.g. |
| 110 | * /tmp/my_shm/my_session-20180612-135822/ust/uid/1000/64-bit/metadata |
| 111 | * |
| 112 | * Note that this is not the trace's final metadata file. It is |
| 113 | * only meant to be used to read the contents of the ring buffers |
| 114 | * in the event of a crash. |
| 115 | * |
| 116 | * metadata_fd is a file descriptor that points to the file at |
| 117 | * 'metadata_path'. |
| 118 | */ |
| 119 | char _root_shm_path[PATH_MAX] = {}; |
| 120 | char _shm_path[PATH_MAX] = {}; |
| 121 | char _metadata_path[PATH_MAX] = {}; |
| 122 | /* File-backed metadata FD */ |
| 123 | int _metadata_fd = -1; |
| 124 | |
| 125 | /* |
| 126 | * Hash table containing channels sent by the UST tracer. MUST |
| 127 | * be accessed with a RCU read side lock acquired. |
| 128 | */ |
| 129 | lttng_ht::uptr _channels; |
| 130 | |
| 131 | /* |
| 132 | * Unique key to identify the metadata on the consumer side. |
| 133 | */ |
| 134 | uint64_t _metadata_key = 0; |
| 135 | /* |
| 136 | * Indicates if the metadata is closed on the consumer side. This is to |
| 137 | * avoid double close of metadata when an application unregisters AND |
| 138 | * deletes its sessions. |
| 139 | */ |
| 140 | bool _metadata_closed = false; |
| 141 | |
| 142 | /* User and group owning the session. */ |
| 143 | uid_t _uid = -1; |
| 144 | gid_t _gid = -1; |
| 145 | |
| 146 | /* Enumerations table. */ |
| 147 | lttng_ht::uptr _enums; |
| 148 | |
| 149 | /* |
| 150 | * Copy of the tracer version when the first app is registered. |
| 151 | * It is used if we need to regenerate the metadata. |
| 152 | */ |
| 153 | uint32_t _app_tracer_version_major = 0; |
| 154 | uint32_t _app_tracer_version_minor = 0; |
| 155 | |
| 156 | /* The id of the parent session */ |
| 157 | ltt_session::id_t _tracing_id = -1ULL; |
| 158 | |
| 159 | protected: |
| 160 | /* Prevent instanciation of this base class. */ |
| 161 | ust_registry_session(const struct lttng::sessiond::trace::abi& abi, |
| 162 | unsigned int app_tracer_version_major, |
| 163 | unsigned int app_tracer_version_minor, |
| 164 | const char *root_shm_path, |
| 165 | const char *shm_path, |
| 166 | uid_t euid, |
| 167 | gid_t egid, |
| 168 | uint64_t tracing_id); |
| 169 | virtual void _visit_environment( |
| 170 | lttng::sessiond::trace::trace_class_visitor& trace_class_visitor) |
| 171 | const override; |
| 172 | void _generate_metadata(); |
| 173 | |
| 174 | private: |
| 175 | uint32_t _get_next_channel_id(); |
| 176 | void _increase_metadata_size(size_t reservation_length); |
| 177 | void _append_metadata_fragment(const std::string& fragment); |
| 178 | void _reset_metadata(); |
| 179 | |
| 180 | virtual void _accept_on_clock_classes( |
| 181 | lttng::sessiond::trace::trace_class_visitor& trace_class_visitor) |
| 182 | const override final; |
| 183 | virtual void _accept_on_stream_classes( |
| 184 | lttng::sessiond::trace::trace_class_visitor& trace_class_visitor) |
| 185 | const override final; |
| 186 | |
| 187 | lttng::sessiond::ust::clock_class _clock; |
| 188 | const lttng::sessiond::trace::trace_class_visitor::cuptr _metadata_generating_visitor; |
| 189 | }; |
| 190 | |
| 191 | class ust_registry_session_per_uid : public ust_registry_session { |
| 192 | public: |
| 193 | ust_registry_session_per_uid(const struct lttng::sessiond::trace::abi& trace_abi, |
| 194 | uint32_t major, |
| 195 | uint32_t minor, |
| 196 | const char *root_shm_path, |
| 197 | const char *shm_path, |
| 198 | uid_t euid, |
| 199 | gid_t egid, |
| 200 | uint64_t tracing_id, |
| 201 | uid_t tracing_uid); |
| 202 | |
| 203 | virtual lttng_buffer_type get_buffering_scheme() const noexcept override final; |
| 204 | |
| 205 | private: |
| 206 | virtual void _visit_environment( |
| 207 | lttng::sessiond::trace::trace_class_visitor& trace_class_visitor) |
| 208 | const override final; |
| 209 | |
| 210 | const uid_t _tracing_uid; |
| 211 | }; |
| 212 | |
| 213 | class ust_registry_session_per_pid : public ust_registry_session { |
| 214 | public: |
| 215 | ust_registry_session_per_pid(const struct ust_app& app, |
| 216 | const struct lttng::sessiond::trace::abi& |
| 217 | trace_abi, |
| 218 | uint32_t major, |
| 219 | uint32_t minor, |
| 220 | const char *root_shm_path, |
| 221 | const char *shm_path, |
| 222 | uid_t euid, |
| 223 | gid_t egid, |
| 224 | uint64_t tracing_id); |
| 225 | |
| 226 | virtual lttng_buffer_type get_buffering_scheme() const noexcept override final; |
| 227 | |
| 228 | private: |
| 229 | virtual void _visit_environment( |
| 230 | lttng::sessiond::trace::trace_class_visitor& trace_class_visitor) |
| 231 | const override final; |
| 232 | |
| 233 | const unsigned int _tracer_patch_level_version; |
| 234 | const pid_t _vpid; |
| 235 | const std::string _procname; |
| 236 | const std::time_t _app_creation_time; |
| 237 | }; |
| 238 | |
| 239 | |
| 240 | namespace lttng { |
| 241 | namespace sessiond { |
| 242 | namespace ust { |
| 243 | |
| 244 | class registry_enum { |
| 245 | public: |
| 246 | using const_rcu_protected_reference = lttng::locked_reference<const registry_enum, lttng::urcu::unique_read_lock>; |
| 247 | |
| 248 | registry_enum(std::string name, enum lttng::sessiond::trace::integer_type::signedness signedness); |
| 249 | virtual ~registry_enum() = default; |
| 250 | |
| 251 | std::string name; |
| 252 | enum lttng::sessiond::trace::integer_type::signedness signedness; |
| 253 | /* enum id in session */ |
| 254 | uint64_t id = -1ULL; |
| 255 | /* Enumeration node in session hash table. */ |
| 256 | struct lttng_ht_node_str node; |
| 257 | /* For delayed reclaim. */ |
| 258 | struct rcu_head rcu_head; |
| 259 | |
| 260 | friend bool operator==(const registry_enum& lhs, const registry_enum& rhs) noexcept; |
| 261 | protected: |
| 262 | virtual bool _is_equal(const registry_enum& other) const noexcept = 0; |
| 263 | }; |
| 264 | |
| 265 | bool operator==(const registry_enum& lhs, const registry_enum& rhs) noexcept; |
| 266 | |
| 267 | namespace details { |
| 268 | template <class MappingIntegerType> |
| 269 | typename trace::typed_enumeration_type<MappingIntegerType>::mapping mapping_from_ust_ctl_entry( |
| 270 | const lttng_ust_ctl_enum_entry& entry) |
| 271 | { |
| 272 | if (entry.u.extra.options & LTTNG_UST_CTL_UST_ENUM_ENTRY_OPTION_IS_AUTO) { |
| 273 | return {entry.string}; |
| 274 | |
| 275 | } else { |
| 276 | return {entry.string, |
| 277 | {(MappingIntegerType) entry.start.value, |
| 278 | (MappingIntegerType) entry.end.value}}; |
| 279 | } |
| 280 | } |
| 281 | |
| 282 | template <class MappingIntegerType> |
| 283 | typename trace::typed_enumeration_type<MappingIntegerType>::mappings mappings_from_ust_ctl_entries( |
| 284 | const lttng_ust_ctl_enum_entry *in_entries, size_t in_entry_count) |
| 285 | { |
| 286 | typename trace::typed_enumeration_type<MappingIntegerType>::mappings mappings; |
| 287 | |
| 288 | for (size_t entry_idx = 0; entry_idx < in_entry_count; entry_idx++) { |
| 289 | const auto& entry = in_entries[entry_idx]; |
| 290 | |
| 291 | mappings.emplace_back(mapping_from_ust_ctl_entry<MappingIntegerType>(entry)); |
| 292 | } |
| 293 | |
| 294 | return mappings; |
| 295 | } |
| 296 | } /* namespace details */ |
| 297 | |
| 298 | template <class MappingIntegerType> |
| 299 | class registry_typed_enum : public registry_enum { |
| 300 | public: |
| 301 | registry_typed_enum(const char *in_name, |
| 302 | const lttng_ust_ctl_enum_entry *entries, |
| 303 | size_t entry_count) : |
| 304 | registry_enum(in_name, |
| 305 | std::is_signed<MappingIntegerType>::value ? |
| 306 | lttng::sessiond::trace::integer_type::signedness::SIGNED : |
| 307 | lttng::sessiond::trace::integer_type::signedness::UNSIGNED), |
| 308 | _mappings{std::make_shared< |
| 309 | typename trace::typed_enumeration_type<MappingIntegerType>::mappings>( |
| 310 | details::mappings_from_ust_ctl_entries<MappingIntegerType>( |
| 311 | entries, entry_count))} |
| 312 | { |
| 313 | } |
| 314 | |
| 315 | const typename std::shared_ptr<const typename lttng::sessiond::trace::typed_enumeration_type< |
| 316 | MappingIntegerType>::mappings> |
| 317 | _mappings; |
| 318 | |
| 319 | protected: |
| 320 | virtual bool _is_equal(const registry_enum& base_other) const noexcept |
| 321 | { |
| 322 | const auto &other = static_cast<decltype(*this)&>(base_other); |
| 323 | |
| 324 | /* Don't compare IDs as some comparisons are performed before an id is assigned. */ |
| 325 | return this->name == other.name && *this->_mappings == *other._mappings; |
| 326 | } |
| 327 | }; |
| 328 | |
| 329 | using registry_signed_enum = registry_typed_enum<int64_t>; |
| 330 | using registry_unsigned_enum = registry_typed_enum<uint64_t>; |
| 331 | |
| 332 | } /* namespace ust */ |
| 333 | } /* namespace sessiond */ |
| 334 | } /* namespace lttng */ |
| 335 | |
| 336 | #ifdef HAVE_LIBLTTNG_UST_CTL |
| 337 | |
| 338 | /* |
| 339 | * Create per-uid registry with default values. |
| 340 | * |
| 341 | * Return new instance on success, nullptr on error. |
| 342 | */ |
| 343 | ust_registry_session *ust_registry_session_per_uid_create( |
| 344 | const lttng::sessiond::trace::abi& abi, |
| 345 | uint32_t major, |
| 346 | uint32_t minor, |
| 347 | const char *root_shm_path, |
| 348 | const char *shm_path, |
| 349 | uid_t euid, |
| 350 | gid_t egid, |
| 351 | uint64_t tracing_id, |
| 352 | uid_t tracing_uid); |
| 353 | |
| 354 | /* |
| 355 | * Create per-pid registry with default values. |
| 356 | * |
| 357 | * Return new instance on success, nullptr on error. |
| 358 | */ |
| 359 | ust_registry_session *ust_registry_session_per_pid_create(struct ust_app *app, |
| 360 | const lttng::sessiond::trace::abi& abi, |
| 361 | uint32_t major, |
| 362 | uint32_t minor, |
| 363 | const char *root_shm_path, |
| 364 | const char *shm_path, |
| 365 | uid_t euid, |
| 366 | gid_t egid, |
| 367 | uint64_t tracing_id); |
| 368 | void ust_registry_session_destroy(ust_registry_session *session); |
| 369 | |
| 370 | void ust_registry_channel_destroy_event(lttng::sessiond::ust::registry_channel *chan, |
| 371 | lttng::sessiond::ust::registry_event *event); |
| 372 | |
| 373 | int ust_registry_create_or_find_enum(ust_registry_session *session, |
| 374 | int session_objd, char *name, |
| 375 | struct lttng_ust_ctl_enum_entry *entries, size_t nr_entries, |
| 376 | uint64_t *enum_id); |
| 377 | lttng::sessiond::ust::registry_enum::const_rcu_protected_reference |
| 378 | ust_registry_lookup_enum_by_id(const ust_registry_session *session, |
| 379 | const char *name, uint64_t id); |
| 380 | void ust_registry_destroy_enum(ust_registry_session *reg_session, |
| 381 | lttng::sessiond::ust::registry_enum *reg_enum); |
| 382 | #else /* HAVE_LIBLTTNG_UST_CTL */ |
| 383 | |
| 384 | static inline |
| 385 | ust_registry_session *ust_registry_session_per_uid_create( |
| 386 | uint32_t bits_per_long __attribute__((unused)), |
| 387 | uint32_t uint8_t_alignment __attribute__((unused)), |
| 388 | uint32_t uint16_t_alignment __attribute__((unused)), |
| 389 | uint32_t uint32_t_alignment __attribute__((unused)), |
| 390 | uint32_t uint64_t_alignment __attribute__((unused)), |
| 391 | uint32_t long_alignment __attribute__((unused)), |
| 392 | int byte_order __attribute__((unused)), |
| 393 | uint32_t major __attribute__((unused)), |
| 394 | uint32_t minor __attribute__((unused)), |
| 395 | const char *root_shm_path __attribute__((unused)), |
| 396 | const char *shm_path __attribute__((unused)), |
| 397 | uid_t euid __attribute__((unused)), |
| 398 | gid_t egid __attribute__((unused)), |
| 399 | uint64_t tracing_id __attribute__((unused)), |
| 400 | uid_t tracing_uid __attribute__((unused))) |
| 401 | { |
| 402 | return nullptr; |
| 403 | } |
| 404 | |
| 405 | static inline |
| 406 | ust_registry_session *ust_registry_session_per_pid_create( |
| 407 | struct ust_app *app __attribute__((unused)), |
| 408 | uint32_t bits_per_long __attribute__((unused)), |
| 409 | uint32_t uint8_t_alignment __attribute__((unused)), |
| 410 | uint32_t uint16_t_alignment __attribute__((unused)), |
| 411 | uint32_t uint32_t_alignment __attribute__((unused)), |
| 412 | uint32_t uint64_t_alignment __attribute__((unused)), |
| 413 | uint32_t long_alignment __attribute__((unused)), |
| 414 | int byte_order __attribute__((unused)), |
| 415 | uint32_t major __attribute__((unused)), |
| 416 | uint32_t minor __attribute__((unused)), |
| 417 | const char *root_shm_path __attribute__((unused)), |
| 418 | const char *shm_path __attribute__((unused)), |
| 419 | uid_t euid __attribute__((unused)), |
| 420 | gid_t egid __attribute__((unused)), |
| 421 | uint64_t tracing_id __attribute__((unused))) |
| 422 | { |
| 423 | return nullptr; |
| 424 | } |
| 425 | |
| 426 | static inline |
| 427 | void ust_registry_session_destroy( |
| 428 | ust_registry_session *session __attribute__((unused))) |
| 429 | {} |
| 430 | |
| 431 | static inline |
| 432 | void ust_registry_destroy_event( |
| 433 | lttng::sessiond::ust::registry_channel *chan __attribute__((unused)), |
| 434 | lttng::sessiond::ust::registry_event *event __attribute__((unused))) |
| 435 | {} |
| 436 | |
| 437 | /* The app object can be NULL for registry shared across applications. */ |
| 438 | static inline |
| 439 | int ust_metadata_session_statedump( |
| 440 | ust_registry_session *session __attribute__((unused))) |
| 441 | { |
| 442 | return 0; |
| 443 | } |
| 444 | |
| 445 | static inline |
| 446 | int ust_metadata_channel_statedump( |
| 447 | ust_registry_session *session __attribute__((unused)), |
| 448 | lttng::sessiond::ust::registry_channel *chan __attribute__((unused))) |
| 449 | { |
| 450 | return 0; |
| 451 | } |
| 452 | |
| 453 | static inline |
| 454 | int ust_metadata_event_statedump( |
| 455 | ust_registry_session *session __attribute__((unused)), |
| 456 | lttng::sessiond::ust::registry_channel *chan __attribute__((unused)), |
| 457 | lttng::sessiond::ust::registry_event *event __attribute__((unused))) |
| 458 | { |
| 459 | return 0; |
| 460 | } |
| 461 | |
| 462 | static inline |
| 463 | int ust_registry_create_or_find_enum( |
| 464 | ust_registry_session *session __attribute__((unused)), |
| 465 | int session_objd __attribute__((unused)), |
| 466 | char *name __attribute__((unused)), |
| 467 | struct lttng_ust_ctl_enum_entry *entries __attribute__((unused)), |
| 468 | size_t nr_entries __attribute__((unused)), |
| 469 | uint64_t *enum_id __attribute__((unused))) |
| 470 | { |
| 471 | return 0; |
| 472 | } |
| 473 | |
| 474 | static inline |
| 475 | struct ust_registry_enum * |
| 476 | ust_registry_lookup_enum_by_id( |
| 477 | const ust_registry_session *session __attribute__((unused)), |
| 478 | const char *name __attribute__((unused)), |
| 479 | uint64_t id __attribute__((unused))) |
| 480 | { |
| 481 | return NULL; |
| 482 | } |
| 483 | |
| 484 | static inline |
| 485 | void ust_registry_destroy_enum(ust_registry_session *reg_session __attribute__((unused)), |
| 486 | struct ust_registry_enum *reg_enum __attribute__((unused))) |
| 487 | {} |
| 488 | |
| 489 | #endif /* HAVE_LIBLTTNG_UST_CTL */ |
| 490 | |
| 491 | #endif /* LTTNG_UST_REGISTRY_H */ |