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aeeb48c6 JG |
1 | /* |
2 | * Copyright (C) 2022 Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
3 | * | |
4 | * SPDX-License-Identifier: GPL-2.0-only | |
5 | * | |
6 | */ | |
7 | ||
d7bfb9b0 JG |
8 | #include "field.hpp" |
9 | #include "lttng-sessiond.hpp" | |
10 | #include "notification-thread-commands.hpp" | |
11 | #include "session.hpp" | |
12 | #include "trace-class.hpp" | |
13 | #include "tsdl-trace-class-visitor.hpp" | |
14 | #include "ust-app.hpp" | |
15 | #include "ust-field-convert.hpp" | |
aeeb48c6 JG |
16 | #include "ust-registry.hpp" |
17 | ||
18 | #include <common/compat/directory-handle.hpp> | |
19 | #include <common/error.hpp> | |
20 | #include <common/exception.hpp> | |
d7bfb9b0 | 21 | #include <common/format.hpp> |
17fd219b | 22 | #include <common/macros.hpp> |
d7bfb9b0 | 23 | #include <common/make-unique.hpp> |
17fd219b | 24 | #include <common/pthread-lock.hpp> |
aeeb48c6 | 25 | #include <common/runas.hpp> |
d7bfb9b0 JG |
26 | #include <common/time.hpp> |
27 | #include <common/urcu.hpp> | |
aeeb48c6 JG |
28 | |
29 | #include <fcntl.h> | |
d7bfb9b0 JG |
30 | #include <functional> |
31 | #include <mutex> | |
aeeb48c6 JG |
32 | #include <sstream> |
33 | #include <string> | |
34 | ||
d7bfb9b0 JG |
35 | namespace ls = lttng::sessiond; |
36 | namespace lst = lttng::sessiond::trace; | |
37 | namespace lsu = lttng::sessiond::ust; | |
38 | ||
39 | namespace { | |
40 | lttng_uuid generate_uuid_or_throw() | |
41 | { | |
42 | lttng_uuid new_uuid; | |
43 | ||
44 | if (lttng_uuid_generate(new_uuid)) { | |
45 | LTTNG_THROW_POSIX("Failed to generate UST uuid", errno); | |
46 | } | |
47 | ||
48 | return new_uuid; | |
49 | } | |
50 | ||
51 | int get_count_order(unsigned int count) | |
52 | { | |
53 | int order; | |
54 | ||
55 | order = lttng_fls(count) - 1; | |
56 | if (count & (count - 1)) { | |
57 | order++; | |
58 | } | |
59 | ||
60 | LTTNG_ASSERT(order >= 0); | |
61 | return order; | |
62 | } | |
63 | ||
64 | void clear_metadata_file(int fd) | |
65 | { | |
66 | const auto lseek_ret = lseek(fd, 0, SEEK_SET); | |
67 | if (lseek_ret < 0) { | |
68 | LTTNG_THROW_POSIX("Failed to seek to the beginning of the metadata file while clearing it", errno); | |
69 | } | |
70 | ||
71 | const auto ret = ftruncate(fd, 0); | |
72 | if (ret < 0) { | |
73 | LTTNG_THROW_POSIX("Failed to truncate the metadata file while clearing it", errno); | |
74 | } | |
75 | } | |
76 | ||
77 | /* | |
78 | * Validate that the id has reached the maximum allowed or not. | |
79 | */ | |
80 | bool is_max_channel_id(uint32_t id) | |
81 | { | |
82 | return id == UINT32_MAX; | |
83 | } | |
84 | ||
85 | void destroy_channel_rcu(struct rcu_head *head) | |
86 | { | |
87 | DIAGNOSTIC_PUSH | |
88 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF | |
89 | lsu::registry_channel *chan = | |
90 | caa_container_of(head, lsu::registry_channel, _rcu_head); | |
91 | DIAGNOSTIC_POP | |
92 | ||
93 | delete chan; | |
94 | } | |
95 | ||
96 | /* | |
97 | * Destroy every element of the registry and free the memory. This does NOT | |
98 | * free the registry pointer since it might not have been allocated before so | |
99 | * it's the caller responsability. | |
100 | */ | |
101 | void destroy_channel(lsu::registry_channel *chan, bool notify) | |
102 | { | |
103 | struct lttng_ht_iter iter; | |
104 | lttng::sessiond::ust::registry_event *event; | |
105 | enum lttng_error_code cmd_ret; | |
106 | ||
107 | LTTNG_ASSERT(chan); | |
108 | ||
109 | if (notify) { | |
110 | cmd_ret = notification_thread_command_remove_channel( | |
111 | the_notification_thread_handle, | |
112 | chan->_consumer_key, LTTNG_DOMAIN_UST); | |
113 | if (cmd_ret != LTTNG_OK) { | |
114 | ERR("Failed to remove channel from notification thread"); | |
115 | } | |
116 | } | |
117 | ||
118 | if (chan->_events) { | |
119 | lttng::urcu::read_lock_guard read_lock_guard; | |
120 | ||
121 | /* Destroy all event associated with this registry. */ | |
122 | DIAGNOSTIC_PUSH | |
123 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF | |
124 | cds_lfht_for_each_entry( | |
125 | chan->_events->ht, &iter.iter, event, _node.node) { | |
126 | /* Delete the node from the ht and free it. */ | |
127 | ust_registry_channel_destroy_event(chan, event); | |
128 | } | |
129 | DIAGNOSTIC_POP | |
130 | } | |
131 | ||
132 | call_rcu(&chan->_rcu_head, destroy_channel_rcu); | |
133 | } | |
134 | } /* namespace */ | |
135 | ||
b0f2e8db | 136 | void lsu::details::locked_registry_session_release(lsu::registry_session *session) |
d7bfb9b0 JG |
137 | { |
138 | pthread_mutex_unlock(&session->_lock); | |
139 | } | |
140 | ||
b0f2e8db | 141 | lsu::registry_session::registry_session(const struct lst::abi& in_abi, |
aeeb48c6 JG |
142 | uint32_t major, |
143 | uint32_t minor, | |
144 | const char *root_shm_path, | |
145 | const char *shm_path, | |
146 | uid_t euid, | |
147 | gid_t egid, | |
148 | uint64_t tracing_id) : | |
d7bfb9b0 | 149 | lst::trace_class(in_abi, generate_uuid_or_throw()), |
aeeb48c6 JG |
150 | _uid{euid}, |
151 | _gid{egid}, | |
152 | _app_tracer_version_major{major}, | |
153 | _app_tracer_version_minor{minor}, | |
d7bfb9b0 JG |
154 | _tracing_id{tracing_id}, |
155 | _metadata_generating_visitor{lttng::make_unique<ls::tsdl::trace_class_visitor>( | |
156 | abi, [this](const std::string& fragment) { | |
157 | _append_metadata_fragment(fragment); | |
158 | })} | |
aeeb48c6 JG |
159 | { |
160 | pthread_mutex_init(&_lock, NULL); | |
161 | strncpy(_root_shm_path, root_shm_path, sizeof(_root_shm_path)); | |
162 | _root_shm_path[sizeof(_root_shm_path) - 1] = '\0'; | |
163 | if (shm_path[0]) { | |
164 | strncpy(_shm_path, shm_path, sizeof(_shm_path)); | |
165 | _shm_path[sizeof(_shm_path) - 1] = '\0'; | |
166 | strncpy(_metadata_path, shm_path, sizeof(_metadata_path)); | |
167 | _metadata_path[sizeof(_metadata_path) - 1] = '\0'; | |
168 | strncat(_metadata_path, "/metadata", | |
169 | sizeof(_metadata_path) - strlen(_metadata_path) - 1); | |
170 | } | |
171 | ||
172 | if (_shm_path[0]) { | |
173 | if (run_as_mkdir_recursive(_shm_path, S_IRWXU | S_IRWXG, euid, egid)) { | |
174 | LTTNG_THROW_POSIX("run_as_mkdir_recursive", errno); | |
175 | } | |
176 | } | |
177 | ||
178 | if (_metadata_path[0]) { | |
179 | /* Create metadata file. */ | |
180 | const int ret = run_as_open(_metadata_path, O_WRONLY | O_CREAT | O_EXCL, | |
181 | S_IRUSR | S_IWUSR, euid, egid); | |
182 | ||
183 | if (ret < 0) { | |
184 | std::stringstream ss; | |
185 | ||
186 | ss << "Opening metadata file '" << _metadata_path << "'"; | |
187 | LTTNG_THROW_POSIX(ss.str(), errno); | |
188 | } | |
189 | ||
190 | _metadata_fd = ret; | |
191 | } | |
192 | ||
193 | _enums.reset(lttng_ht_new(0, LTTNG_HT_TYPE_STRING)); | |
194 | if (!_enums) { | |
195 | LTTNG_THROW_POSIX("Failed to create enums hash table", ENOMEM); | |
196 | } | |
197 | ||
198 | /* hash/match functions are specified at call site. */ | |
199 | _enums->match_fct = NULL; | |
200 | _enums->hash_fct = NULL; | |
201 | ||
202 | _channels.reset(lttng_ht_new(0, LTTNG_HT_TYPE_U64)); | |
203 | if (!_channels) { | |
204 | LTTNG_THROW_POSIX("Failed to create channels hash table", ENOMEM); | |
205 | } | |
aeeb48c6 JG |
206 | } |
207 | ||
b0f2e8db | 208 | lsu::registry_session::~registry_session() |
aeeb48c6 JG |
209 | { |
210 | int ret; | |
211 | struct lttng_ht_iter iter; | |
d7bfb9b0 JG |
212 | lsu::registry_channel *chan; |
213 | lsu::registry_enum *reg_enum; | |
aeeb48c6 JG |
214 | |
215 | /* On error, EBUSY can be returned if lock. Code flow error. */ | |
216 | ret = pthread_mutex_destroy(&_lock); | |
217 | LTTNG_ASSERT(!ret); | |
218 | ||
219 | if (_channels) { | |
d7bfb9b0 JG |
220 | lttng::urcu::read_lock_guard read_lock_guard; |
221 | ||
aeeb48c6 | 222 | /* Destroy all event associated with this registry. */ |
d7bfb9b0 JG |
223 | DIAGNOSTIC_PUSH |
224 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF | |
225 | cds_lfht_for_each_entry(_channels->ht, &iter.iter, chan, _node.node) { | |
aeeb48c6 JG |
226 | /* Delete the node from the ht and free it. */ |
227 | ret = lttng_ht_del(_channels.get(), &iter); | |
228 | LTTNG_ASSERT(!ret); | |
d7bfb9b0 | 229 | destroy_channel(chan, true); |
aeeb48c6 | 230 | } |
d7bfb9b0 | 231 | DIAGNOSTIC_POP |
aeeb48c6 JG |
232 | } |
233 | ||
234 | free(_metadata); | |
235 | if (_metadata_fd >= 0) { | |
236 | ret = close(_metadata_fd); | |
237 | if (ret) { | |
238 | PERROR("close"); | |
239 | } | |
240 | ||
241 | ret = run_as_unlink(_metadata_path, _uid, _gid); | |
242 | if (ret) { | |
243 | PERROR("unlink"); | |
244 | } | |
245 | } | |
246 | ||
247 | if (_root_shm_path[0]) { | |
248 | /* Try to delete the directory hierarchy. */ | |
249 | (void) run_as_rmdir_recursive(_root_shm_path, _uid, _gid, | |
250 | LTTNG_DIRECTORY_HANDLE_SKIP_NON_EMPTY_FLAG); | |
251 | } | |
252 | ||
253 | /* Destroy the enum hash table */ | |
254 | if (_enums) { | |
255 | rcu_read_lock(); | |
256 | /* Destroy all enum entries associated with this registry. */ | |
d7bfb9b0 JG |
257 | DIAGNOSTIC_PUSH |
258 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF | |
aeeb48c6 JG |
259 | cds_lfht_for_each_entry (_enums->ht, &iter.iter, reg_enum, node.node) { |
260 | ust_registry_destroy_enum(this, reg_enum); | |
261 | } | |
d7bfb9b0 | 262 | DIAGNOSTIC_POP |
aeeb48c6 JG |
263 | |
264 | rcu_read_unlock(); | |
265 | } | |
266 | } | |
267 | ||
b0f2e8db | 268 | lsu::registry_session::locked_ptr lsu::registry_session::lock() |
aeeb48c6 | 269 | { |
d7bfb9b0 JG |
270 | pthread_mutex_lock(&_lock); |
271 | return locked_ptr(this); | |
272 | } | |
273 | ||
274 | /* | |
275 | * Initialize registry with default values. | |
276 | */ | |
b0f2e8db | 277 | void lsu::registry_session::add_channel(uint64_t key) |
d7bfb9b0 JG |
278 | { |
279 | lttng::pthread::lock_guard session_lock_guard(_lock); | |
280 | ||
281 | /* | |
282 | * Assign a channel ID right now since the event notification comes | |
283 | * *before* the channel notify so the ID needs to be set at this point so | |
284 | * the metadata can be dumped for that event. | |
285 | */ | |
286 | if (is_max_channel_id(_used_channel_id)) { | |
287 | LTTNG_THROW_ERROR(fmt::format("Failed to allocate unique id for channel under session while adding channel")); | |
288 | } | |
289 | ||
290 | auto chan = new lsu::registry_channel( | |
291 | _get_next_channel_id(), | |
292 | /* Registered channel listener. */ | |
293 | [this](const lsu::registry_channel& registered_channel) { | |
294 | /* | |
295 | * Channel registration completed, serialize it's layout's | |
296 | * description. | |
297 | */ | |
298 | registered_channel.accept(*_metadata_generating_visitor); | |
299 | }, | |
300 | /* Added event listener. */ | |
301 | [this](const lsu::registry_channel& channel, | |
302 | const lsu::registry_event& added_event) { | |
303 | /* | |
304 | * The channel and its event classes will be dumped at once when | |
305 | * it is registered. This check prevents event classes from being | |
306 | * declared before their stream class. | |
307 | */ | |
308 | if (channel.is_registered()) { | |
309 | added_event.accept(*_metadata_generating_visitor); | |
310 | } | |
311 | }); | |
312 | ||
313 | lttng::urcu::read_lock_guard rcu_read_lock_guard; | |
314 | lttng_ht_node_init_u64(&chan->_node, key); | |
315 | lttng_ht_add_unique_u64(_channels.get(), &chan->_node); | |
316 | } | |
317 | ||
b0f2e8db | 318 | lttng::sessiond::ust::registry_channel& lsu::registry_session::get_channel( |
d7bfb9b0 JG |
319 | uint64_t channel_key) const |
320 | { | |
321 | lttng::urcu::read_lock_guard read_lock_guard; | |
322 | struct lttng_ht_node_u64 *node; | |
323 | struct lttng_ht_iter iter; | |
324 | ||
325 | ASSERT_LOCKED(_lock); | |
326 | ||
327 | lttng_ht_lookup(_channels.get(), &channel_key, &iter); | |
328 | node = lttng_ht_iter_get_node_u64(&iter); | |
329 | if (!node) { | |
330 | LTTNG_THROW_INVALID_ARGUMENT_ERROR(fmt::format( | |
331 | "Invalid channel key provided: channel key = {}", channel_key)); | |
332 | } | |
17fd219b | 333 | |
d7bfb9b0 JG |
334 | DIAGNOSTIC_PUSH |
335 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF | |
336 | auto chan = caa_container_of(node, lsu::registry_channel, _node); | |
337 | DIAGNOSTIC_POP | |
338 | return *chan; | |
339 | } | |
340 | ||
b0f2e8db | 341 | void lsu::registry_session::remove_channel(uint64_t channel_key, bool notify) |
d7bfb9b0 JG |
342 | { |
343 | struct lttng_ht_iter iter; | |
344 | int ret; | |
345 | lttng::urcu::read_lock_guard read_lock_guard; | |
346 | ||
347 | ASSERT_LOCKED(_lock); | |
348 | auto& channel = get_channel(channel_key); | |
349 | ||
350 | iter.iter.node = &channel._node.node; | |
351 | ret = lttng_ht_del(_channels.get(), &iter); | |
352 | LTTNG_ASSERT(!ret); | |
353 | destroy_channel(&channel, notify); | |
354 | } | |
355 | ||
b0f2e8db | 356 | void lsu::registry_session::_visit_environment( |
d7bfb9b0 JG |
357 | lttng::sessiond::trace::trace_class_visitor& visitor) const |
358 | { | |
359 | ASSERT_LOCKED(_lock); | |
360 | ||
361 | visitor.visit(lst::environment_field<const char *>("domain", "ust")); | |
362 | visitor.visit(lst::environment_field<const char *>("tracer_name", "lttng-ust")); | |
363 | visitor.visit(lst::environment_field<int64_t>("tracer_major", _app_tracer_version_major)); | |
364 | visitor.visit(lst::environment_field<int64_t>("tracer_minor", _app_tracer_version_minor)); | |
365 | visitor.visit(lst::environment_field<const char *>("tracer_buffering_scheme", | |
366 | get_buffering_scheme() == LTTNG_BUFFER_PER_PID ? "pid" : "uid")); | |
367 | visitor.visit(lst::environment_field<int64_t>("architecture_bit_width", abi.bits_per_long)); | |
368 | ||
369 | { | |
370 | /* The caller already holds the session and session list locks. */ | |
371 | ASSERT_SESSION_LIST_LOCKED(); | |
372 | const auto session = lttng::sessiond::find_session_by_id(_tracing_id); | |
373 | ||
374 | LTTNG_ASSERT(session); | |
375 | ASSERT_LOCKED(session->lock); | |
376 | ||
377 | visitor.visit(lst::environment_field<const char *>("trace_name", | |
378 | session->has_auto_generated_name ? DEFAULT_SESSION_NAME : | |
379 | session->name)); | |
380 | visitor.visit(lst::environment_field<std::string>("trace_creation_datetime", | |
381 | lttng::utils::time_to_iso8601_str(session->creation_time))); | |
382 | visitor.visit(lst::environment_field<const char *>("hostname", session->hostname)); | |
aeeb48c6 JG |
383 | } |
384 | } | |
d7bfb9b0 | 385 | |
b0f2e8db | 386 | void lsu::registry_session::_accept_on_clock_classes(lst::trace_class_visitor& visitor) const |
d7bfb9b0 JG |
387 | { |
388 | ASSERT_LOCKED(_lock); | |
389 | _clock.accept(visitor); | |
390 | } | |
391 | ||
b0f2e8db | 392 | void lsu::registry_session::_accept_on_stream_classes(lst::trace_class_visitor& visitor) const |
d7bfb9b0 JG |
393 | { |
394 | ASSERT_LOCKED(_lock); | |
395 | ||
396 | std::vector<const lttng::sessiond::ust::registry_channel *> sorted_stream_classes; | |
397 | ||
398 | { | |
399 | lttng::urcu::read_lock_guard rcu_lock_guard; | |
400 | const lsu::registry_channel *channel; | |
401 | lttng_ht_iter channel_it; | |
402 | ||
403 | DIAGNOSTIC_PUSH | |
404 | DIAGNOSTIC_IGNORE_INVALID_OFFSETOF | |
405 | cds_lfht_for_each_entry(_channels->ht, &channel_it.iter, channel, _node.node) { | |
406 | sorted_stream_classes.emplace_back(channel); | |
407 | } | |
408 | DIAGNOSTIC_POP | |
409 | } | |
410 | ||
411 | std::sort(sorted_stream_classes.begin(), sorted_stream_classes.end(), | |
412 | [](const lttng::sessiond::ust::registry_channel *a, | |
413 | const lttng::sessiond::ust::registry_channel *b) { | |
414 | return a->id < b->id; | |
415 | }); | |
416 | ||
417 | for (const auto stream_class : sorted_stream_classes) { | |
418 | stream_class->accept(visitor); | |
419 | } | |
420 | } | |
421 | ||
422 | /* | |
423 | * Return next available channel id and increment the used counter. The | |
424 | * is_max_channel_id function MUST be called before in order to validate | |
425 | * if the maximum number of IDs have been reached. If not, it is safe to call | |
426 | * this function. | |
427 | * | |
428 | * Return a unique channel ID. If max is reached, the used_channel_id counter | |
429 | * is returned. | |
430 | */ | |
b0f2e8db | 431 | uint32_t lsu::registry_session::_get_next_channel_id() |
d7bfb9b0 JG |
432 | { |
433 | if (is_max_channel_id(_used_channel_id)) { | |
434 | return _used_channel_id; | |
435 | } | |
436 | ||
437 | _used_channel_id++; | |
438 | return _next_channel_id++; | |
439 | } | |
440 | ||
b0f2e8db | 441 | void lsu::registry_session::_increase_metadata_size(size_t reservation_length) |
d7bfb9b0 JG |
442 | { |
443 | const auto new_len = _metadata_len + reservation_length; | |
444 | auto new_alloc_len = new_len; | |
445 | const auto old_alloc_len = _metadata_alloc_len; | |
446 | ||
447 | /* Rounding the new allocation length to the next power of 2 would overflow. */ | |
448 | if (new_alloc_len > (UINT32_MAX >> 1)) { | |
449 | LTTNG_THROW_ERROR("Failed to reserve trace metadata storage as the new size would overflow"); | |
450 | } | |
451 | ||
452 | /* The current allocation length is already the largest we can afford. */ | |
453 | if ((old_alloc_len << 1) > (UINT32_MAX >> 1)) { | |
454 | LTTNG_THROW_ERROR("Failed to reserve trace metadata storage as the max size was already reached"); | |
455 | } | |
456 | ||
457 | if (new_alloc_len > old_alloc_len) { | |
458 | new_alloc_len = std::max<size_t>( | |
459 | 1U << get_count_order(new_alloc_len), old_alloc_len << 1); | |
460 | ||
461 | auto newptr = (char *) realloc(_metadata, new_alloc_len); | |
462 | if (!newptr) { | |
463 | LTTNG_THROW_POSIX("Failed to allocate trace metadata storage", errno); | |
464 | } | |
465 | ||
466 | _metadata = newptr; | |
467 | ||
468 | /* We zero directly the memory from start of allocation. */ | |
469 | memset(&_metadata[old_alloc_len], 0, new_alloc_len - old_alloc_len); | |
470 | _metadata_alloc_len = new_alloc_len; | |
471 | } | |
472 | ||
473 | _metadata_len += reservation_length; | |
474 | } | |
475 | ||
b0f2e8db | 476 | void lsu::registry_session::_append_metadata_fragment(const std::string& fragment) |
d7bfb9b0 JG |
477 | { |
478 | const auto offset = _metadata_len; | |
479 | ||
480 | _increase_metadata_size(fragment.size()); | |
481 | memcpy(&_metadata[offset], fragment.c_str(), fragment.size()); | |
482 | ||
483 | if (_metadata_fd >= 0) { | |
484 | const auto bytes_written = | |
485 | lttng_write(_metadata_fd, fragment.c_str(), fragment.size()); | |
486 | ||
487 | if (bytes_written != fragment.size()) { | |
488 | LTTNG_THROW_POSIX("Failed to write trace metadata fragment to file", | |
489 | errno); | |
490 | } | |
491 | } | |
492 | } | |
493 | ||
b0f2e8db | 494 | void lsu::registry_session::_reset_metadata() |
d7bfb9b0 JG |
495 | { |
496 | _metadata_len_sent = 0; | |
497 | memset(_metadata, 0, _metadata_alloc_len); | |
498 | _metadata_len = 0; | |
499 | ||
500 | if (_metadata_fd > 0) { | |
501 | /* Clear the metadata file's content. */ | |
502 | clear_metadata_file(_metadata_fd); | |
503 | } | |
504 | } | |
505 | ||
b0f2e8db | 506 | void lsu::registry_session::_generate_metadata() |
d7bfb9b0 JG |
507 | { |
508 | accept(*_metadata_generating_visitor); | |
509 | } | |
510 | ||
b0f2e8db | 511 | void lsu::registry_session::regenerate_metadata() |
d7bfb9b0 JG |
512 | { |
513 | lttng::pthread::lock_guard registry_lock(_lock); | |
514 | ||
515 | _metadata_version++; | |
516 | _reset_metadata(); | |
517 | _generate_metadata(); | |
518 | } |